Solid lipid nanoparticles as a vehicle for brain-targeted drug delivery: two new strategies of functionalization with apolipoprotein E

NASA Astrophysics Data System (ADS)

Rute Neves, Ana; Fontes Queiroz, Joana; Weksler, Babette; Romero, Ignacio A.; Couraud, Pierre-Olivier; Reis, Salette

2015-12-01

Nanotechnology can be an important tool to improve the permeability of some drugs for the blood-brain barrier. In this work we created a new system to enter the brain by functionalizing solid lipid nanoparticles with apolipoprotein E, aiming to enhance their binding to low-density lipoprotein receptors on the blood-brain barrier endothelial cells. Solid lipid nanoparticles were successfully functionalized with apolipoprotein E using two distinct strategies that took advantage of the strong interaction between biotin and avidin. Transmission electron microscopy images revealed spherical nanoparticles, and dynamic light scattering gave a Z-average under 200 nm, a polydispersity index below 0.2, and a zeta potential between -10 mV and -15 mV. The functionalization of solid lipid nanoparticles with apolipoprotein E was demonstrated by infrared spectroscopy and fluorimetric assays. In vitro cytotoxic effects were evaluated by MTT and LDH assays in the human cerebral microvascular endothelial cells (hCMEC/D3) cell line, a human blood-brain barrier model, and revealed no toxicity up to 1.5 mg ml-1 over 4 h of incubation. The brain permeability was evaluated in transwell devices with hCMEC/D3 monolayers, and a 1.5-fold increment in barrier transit was verified for functionalized nanoparticles when compared with non-functionalized ones. The results suggested that these novel apolipoprotein E-functionalized nanoparticles resulted in dynamic stable systems capable of being used for an improved and specialized brain delivery of drugs through the blood-brain barrier.

Ischemia-reperfusion impairs blood-brain barrier function and alters tight junction protein expression in the ovine fetus.

PubMed

Chen, X; Threlkeld, S W; Cummings, E E; Juan, I; Makeyev, O; Besio, W G; Gaitanis, J; Banks, W A; Sadowska, G B; Stonestreet, B S

2012-12-13

The blood-brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood-brain barrier. Hypoxic-ischemic damage to the blood-brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood-brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood-brain barrier function in the fetus. Blood-brain barrier function was quantified with the blood-to-brain transfer constant (K(i)) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in K(i) (P<0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between K(i) and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood-brain barrier function after ischemia. We conclude that impaired blood-brain barrier function is an important component of hypoxic-ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (K(i)) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood-brain barrier function improves early after injury because the blood-brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood-brain barrier permeability after ischemia. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Efficacy of IPL device combined with intralesional corticosteroid injection for the treatment of keloids and hypertrophic scars with regards to the recovery of skin barrier function: A pilot study.

PubMed

Kim, Dong Young; Park, Hyun Sun; Yoon, Hyun-Sun; Cho, Soyun

2015-10-01

Keloids and hypertrophic scars are prevalent and psychologically distressful dermatologic conditions. Various treatment modalities have been tried but without complete success by any one method. We evaluated the efficacy of a combination of intense pulsed light (IPL) device and intralesional corticosteroid injection for the treatment of keloids and hypertrophic scars with respect to the recovery of skin barrier function. Totally 52 Korean patients were treated by the combined treatment at 4-8-week intervals. Using digital photographs, changes in scar appearance were assessed with modified Vancouver Scar Scale (MVSS), physicians' global assessment (PGA) and patient's satisfaction score. In 12 patients, the stratum corneum (SC) barrier function was assessed by measuring transepidermal water loss (TEWL) and SC capacitance. Most scars demonstrated significant clinical improvement in MVSS, PGA and patient's satisfaction score after the combined therapy. A significant decrease of TEWL and elevation of SC capacitance were also documented after the treatment. The combination therapy (IPL + corticosteroid injection) not only improves the appearance of keloids and hypertrophic scars but also increases the recovery level of skin hydration status in terms of the skin barrier function.

Evidence for the effects of yogurt on gut health and obesity.

PubMed

Pei, Ruisong; Martin, Derek A; DiMarco, Diana M; Bolling, Bradley W

2017-05-24

Obesity is associated with increased risk for chronic diseases, and affects both developed and developing nations. Yogurt is a nutrient-dense food that may benefit individuals with lactose intolerance, constipation and diarrheal diseases, hypertension, cardiovascular diseases, diabetes, and certain types of cancer. Emerging evidence suggests that yogurt consumption might also improve the health of obese individuals. Obesity is often accompanied by chronic, low-grade inflammation perpetuated by adipose tissue and the gut. In the gut, obesity-associated dysregulation of microbiota and impaired gut barrier function may increase endotoxin exposure. Intestinal barrier function can be compromised by pathogens, inflammatory cytokines, endocannabinoids, diet, exercise, and gastrointestinal peptides. Yogurt consumption may improve gut health and reduce chronic inflammation by enhancing innate and adaptive immune responses, intestinal barrier function, lipid profiles, and by regulating appetite. While this evidence suggests that yogurt consumption is beneficial for obese individuals, randomized-controlled trials are needed to further support this hypothesis.

Overall accessibility to traveling by rail for the elderly with and without functional limitations: the whole-trip perspective.

PubMed

Sundling, Catherine; Berglund, Birgitta; Nilsson, Mats E; Emardson, Ragne; Pendrill, Leslie R

2014-12-01

Elderly persons' perceived accessibility to railway traveling depends on their functional limitations/diseases, their functional abilities and their travel behaviors in interaction with the barriers encountered during whole trips. A survey was conducted on a random sample of 1000 city residents (65-85 years old; 57% response rate). The travels were perceived least accessible by respondents with severely reduced functional ability and by those with more than one functional limitation/disease (e.g., restricted mobility and chronic pain). Those who traveled "often", perceived the accessibility to be better than those who traveled less frequently. For travelers with high functional ability, the main barriers to more frequent traveling were travel costs and low punctuality. For those with low functional ability, one's own health was reported to be the main barrier. Our results clarify the links among existing functional limitations/functional abilities, the barriers encountered, the travel behavior, and the overall accessibility to traveling. By operationalizing the whole-trip concept as a chain of events, we deliver practical knowledge on vulnerable groups for decision-making to improve the transport environment for all.

Helminthic therapy: improving mucosal barrier function

PubMed Central

Wolff, Martin J.; Broadhurst, Mara J.

2014-01-01

The epidemiology of autoimmune diseases and helminth infections led to suggestions that helminths could improve inflammatory conditions, which was then tested using animal models. This has translated to clinical investigations aimed at the safe and controlled reintroduction of helminthic exposure to patients suffering from autoimmune diseases (so-called “helminthic therapy”) in an effort to mitigate the inflammatory response. In this review, we will summarize the results of recent clinical trials of helminthic therapy, with particular attention to mechanisms of action. Whereas previous reviews have emphasized immune regulatory mechanisms activated by helminths, we propose that enhancement of mucosal barrier function may have an equally important role in improving conditions of inflammatory bowel diseases. PMID:22464690

Overall Accessibility to Traveling by Rail for the Elderly with and without Functional Limitations: The Whole-Trip Perspective

PubMed Central

Sundling, Catherine; Berglund, Birgitta; Nilsson, Mats E.; Emardson, Ragne; Pendrill, Leslie R.

2014-01-01

Elderly persons’ perceived accessibility to railway traveling depends on their functional limitations/diseases, their functional abilities and their travel behaviors in interaction with the barriers encountered during whole trips. A survey was conducted on a random sample of 1000 city residents (65–85 years old; 57% response rate). The travels were perceived least accessible by respondents with severely reduced functional ability and by those with more than one functional limitation/disease (e.g., restricted mobility and chronic pain). Those who traveled “often”, perceived the accessibility to be better than those who traveled less frequently. For travelers with high functional ability, the main barriers to more frequent traveling were travel costs and low punctuality. For those with low functional ability, one’s own health was reported to be the main barrier. Our results clarify the links among existing functional limitations/functional abilities, the barriers encountered, the travel behavior, and the overall accessibility to traveling. By operationalizing the whole-trip concept as a chain of events, we deliver practical knowledge on vulnerable groups for decision-making to improve the transport environment for all. PMID:25514149

Metformin Improves Ileal Epithelial Barrier Function in Interleukin-10 Deficient Mice

PubMed Central

Xue, Yansong; Zhang, Hanying; Sun, Xiaofei; Zhu, Mei-Jun

2016-01-01

Background and aims The impairment of intestinal epithelial barrier is the main etiologic factor of inflammatory bowel disease. The proper intestinal epithelial proliferation and differentiation is crucial for maintaining intestinal integrity. Metformin is a common anti-diabetic drug. The objective is to evaluate the protective effects of metformin on ileal epithelial barrier integrity using interleukin-10 deficient (IL10KO) mice. Methods Wild-type and IL10KO mice were fed with/without metformin for 6 weeks and then ileum was collected for analyses. The mediatory role of AMP-activated protein kinase (AMPK) was further examined by gain and loss of function study in vitro. Results Compared to wild-type mice, IL10KO mice had increased proliferation, reduced goblet cell and Paneth cell lineage differentiation in the ileum tissue, which was accompanied with increased crypt expansion. Metformin supplementation mitigated intestinal cell proliferation, restored villus/crypt ratio, increased goblet cell and Paneth cell differentiation and improved barrier function. In addition, metformin supplementation in IL10KO mice suppressed macrophage pro-inflammatory activity as indicated by reduced M1 macrophage abundance and decreased pro-inflammatory cytokine IL-1β, TNF-α and IFN-γ expressions. As a target of metformin, AMPK phosphorylation was enhanced in mice treated with metformin, regardless of mouse genotypes. In correlation, the mRNA level of differentiation regulator including bmp4, bmpr2 and math1 were also increased in IL10KO mice supplemented with metformin, which likely explains the enhanced epithelial differentiation in IL10KO mice with metformin. Consistently, in Caco-2 cells, metformin promoted claudin-3 and E-cadherin assembly and mitigated TNF-α-induced fragmentation of tight junction proteins. Gain and loss of function assay also demonstrated AMPK was correlated with epithelial differentiation and proliferation. Conclusions Metformin supplementation promotes secretory cell lineage differentiation, suppresses inflammation and improves epithelial barrier function in IL10KO mice likely through activation of AMPK, showing its beneficial effects on gut epithelial. PMID:28002460

Role of tunnelling in complete and incomplete fusion induced by 9Be on 169Tm and 187Re targets at around barrier energies

NASA Astrophysics Data System (ADS)

Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

2017-04-01

We have analyzed the complete and incomplete fusion excitation function for 9Be +169Tm, 187Re reactions at around barrier energies using the code PLATYPUS based on classical dynamical model. The quantum mechanical tunnelling correction is incorporated at near and sub barrier energies which significantly improves the matching between the data and prediction.

Oral Supplementation with Non-Absorbable Antibiotics or Curcumin Attenuates Western Diet-Induced Atherosclerosis and Glucose Intolerance in LDLR−/− Mice – Role of Intestinal Permeability and Macrophage Activation

PubMed Central

Ghosh, Siddhartha S.; Bie, Jinghua; Wang, Jing; Ghosh, Shobha

2014-01-01

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as Type 2 Diabetes and atherosclerosis) has shifted the focus from Western diet-induced changes in gut microbiota per se to release of gut bacteria-derived products into circulation as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. Under physiological conditions, an intact intestinal barrier prevents this release of LPS underscoring the importance of examining and modulating the direct effects of Western diet on intestinal barrier function. In the present study we evaluated two strategies, namely selective gut decontamination and supplementation with oral curcumin, to modulate Western-diet (WD) induced changes in intestinal barrier function and subsequent development of glucose intolerance and atherosclerosis. LDLR−/− mice were fed WD for 16 weeks and either received non-absorbable antibiotics (Neomycin and polymyxin) in drinking water for selective gut decontamination or gavaged daily with curcumin. WD significantly increased intestinal permeability as assessed by in vivo translocation of FITC-dextran and plasma LPS levels. Selective gut decontamination and supplementation with curcumin significantly attenuated the WD-induced increase in plasma LPS levels (3.32 vs 1.90 or 1.51 EU/ml, respectively) and improved intestinal barrier function at multiple levels (restoring intestinal alkaline phosphatase activity and expression of tight junction proteins, ZO-1 and Claudin-1). Consequently, both these interventions significantly reduced WD-induced glucose intolerance and atherosclerosis in LDLR−/− mice. Activation of macrophages by low levels of LPS (50 ng/ml) and its exacerbation by fatty acids is likely the mechanism by which release of trace amounts of LPS into circulation due to disruption of intestinal barrier function induces the development of these diseases. These studies not only establish the important role of intestinal barrier function, but also identify oral supplementation with curcumin as a potential therapeutic strategy to improve intestinal barrier function and prevent the development of metabolic diseases. PMID:25251395

Non-Saccharomyces yeasts protect against epithelial cell barrier disruption induced by Salmonella enterica subsp. enterica serovar Typhimurium.

PubMed

Smith, I M; Baker, A; Arneborg, N; Jespersen, L

2015-11-01

The human gastrointestinal epithelium makes up the largest barrier separating the body from the external environment. Whereas invasive pathogens cause epithelial barrier disruption, probiotic micro-organisms modulate tight junction regulation and improve epithelial barrier function. In addition, probiotic strains may be able to reduce epithelial barrier disruption caused by pathogenic species. The aim of this study was to explore non-Saccharomyces yeast modulation of epithelial cell barrier function in vitro. Benchmarking against established probiotic strains, we evaluated the ability of four nonpathogenic yeast species to modulate transepithelial electrical resistance (TER) across a monolayer of differentiated human colonocytes (Caco-2 cells). Further, we assessed yeast modulation of a Salmonella Typhimurium-induced epithelial cell barrier function insult. Our findings demonstrate distinct patterns of non-Saccharomyces yeast modulation of epithelial cell barrier function. While the established probiotic yeast Saccharomyces boulardii increased TER across a Caco-2 monolayer by 30%, Kluyveromyces marxianus exhibited significantly stronger properties of TER enhancement (50% TER increase). In addition, our data demonstrate significant yeast-mediated modulation of Salmonella-induced epithelial cell barrier disruption and identify K. marxianus and Metschnikowia gruessii as two non-Saccharomyces yeasts capable of protecting human epithelial cells from pathogen invasion. This study demonstrates distinct patterns of non-Saccharomyces yeast modulation of epithelial cell barrier function in vitro. Further, our data demonstrate significant yeast-mediated modulation of Salmonella Typhimurium-induced epithelial cell barrier disruption and identify Kluyveromyces marxianus and Metschnikowia gruessii as two non-Saccharomyces yeasts capable of protecting human epithelial cells from pathogen invasion. This study is the first to demonstrate significant non-Saccharomyces yeast-mediated epithelial cell barrier protection from Salmonella invasion, thus encouraging future efforts aimed at confirming the observed effects in vivo and driving further strain development towards novel yeast probiotics. © 2015 The Society for Applied Microbiology.

Preservation of the gut by preoperative carbohydrate loading improves postoperative food intake.

PubMed

Luttikhold, Joanna; Oosting, Annemarie; van den Braak, Claudia C M; van Norren, Klaske; Rijna, Herman; van Leeuwen, Paul A M; Bouritius, Hetty

2013-08-01

A carbohydrate (CHO) drink given preoperatively changes the fasted state into a fed state. The ESPEN guidelines for perioperative care include preoperative CHO loading and re-establishment of oral feeding as early as possible after surgery. An intestinal ischaemia reperfusion (IR) animal model was used to investigate whether preoperative CHO loading increases spontaneous postoperative food intake, intestinal barrier function and the catabolic response. Male Wistar rats (n = 65) were subjected to 16 h fasting with ad libitum water and: A) sham laparotomy (Sham fasted, n = 24); B) intestinal ischaemia (IR fasted, n = 27); and C) intestinal ischaemia with preoperatively access to a CHO drink (IR CHO, n = 14). Spontaneous food intake, intestinal barrier function, insulin sensitivity, intestinal motility and plasma amino acids were measured after surgery. The IR CHO animals started eating significantly earlier and also ate significantly more than the IR fasted animals. Furthermore, preoperative CHO loading improved the intestinal barrier function, functional enterocyte metabolic mass measured by citrulline and reduced muscle protein catabolism, as indicated by normalization of the biomarker 3-methylhistidine. Preoperative CHO loading improves food intake, preserves the GI function and reduces the catabolic response in an IR animal model. These findings suggest that preoperative CHO loading preserves the intestinal function in order to accelerate recovery and food intake. If this effect is caused by overcoming the fasted state or CHO loading remains unclear. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Hydroxide Degradation Pathways for Substituted Benzyltrimethyl Ammonium: A DFT Study

DOE PAGES

Long, Hai; Pivovar, Bryan S.

2014-11-01

The stability of cations used in the alkaline exchange membranes has been a major challenge. In this paper, degradation energy barriers were investigated by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations. Findings show that electron-donating substituent groups at meta-position(s) of the benzyl ring could result in increased degradation barriers. However, after investigating more than thirty substituted BTMA+ cations, the largest improvement in degradation barrier found was only 6.7 kJ/mol. This suggests a modest (8×) improvement in stability for this type of approach may be possible, but for anything greater other approaches will need to be pursued.

Improvement of Blood-Brain Barrier Integrity in Traumatic Brain Injury and Hemorrhagic Shock Following Treatment With Valproic Acid and Fresh Frozen Plasma.

PubMed

Nikolian, Vahagn C; Dekker, Simone E; Bambakidis, Ted; Higgins, Gerald A; Dennahy, Isabel S; Georgoff, Patrick E; Williams, Aaron M; Andjelkovic, Anuska V; Alam, Hasan B

2018-01-01

Combined traumatic brain injury and hemorrhagic shock are highly lethal. Following injuries, the integrity of the blood-brain barrier can be impaired, contributing to secondary brain insults. The status of the blood-brain barrier represents a potential factor impacting long-term neurologic outcomes in combined injuries. Treatment strategies involving plasma-based resuscitation and valproic acid therapy have shown efficacy in this setting. We hypothesize that a component of this beneficial effect is related to blood-brain barrier preservation. Following controlled traumatic brain injury, hemorrhagic shock, various resuscitation and treatment strategies were evaluated for their association with blood-brain barrier integrity. Analysis of gene expression profiles was performed using Porcine Gene ST 1.1 microarray. Pathway analysis was completed using network analysis tools (Gene Ontology, Ingenuity Pathway Analysis, and Parametric Gene Set Enrichment Analysis). Female Yorkshire swine were subjected to controlled traumatic brain injury and 2 hours of hemorrhagic shock (40% blood volume, mean arterial pressure 30-35 mmHg). Subjects were resuscitated with 1) normal saline, 2) fresh frozen plasma, 3) hetastarch, 4) fresh frozen plasma + valproic acid, or 5) hetastarch + valproic acid (n = 5 per group). After 6 hours of observation, brains were harvested for evaluation. Immunofluoroscopic evaluation of the traumatic brain injury site revealed significantly increased expression of tight-junction associated proteins (zona occludin-1, claudin-5) following combination therapy (fresh frozen plasma + valproic acid and hetastarch + valproic acid). The extracellular matrix protein laminin was found to have significantly improved expression with combination therapies. Pathway analysis indicated that valproic acid significantly modulated pathways involved in endothelial barrier function and cell signaling. Resuscitation with fresh frozen plasma results in improved expression of proteins essential for blood-brain barrier integrity. The addition of valproic acid provides significant improvement to these protein expression profiles. This is likely secondary to activation of key pathways related to endothelial functions.

Rifaximin Alters Intestinal Bacteria and Prevents Stress-Induced Gut Inflammation and Visceral Hyperalgesia in Rats

PubMed Central

Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y.; Owyang, Chung

2014-01-01

Background & Aims Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. Methods We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction and 454 pyrosequencing were used to analyze bacterial 16S rRNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Results Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Conclusions Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. PMID:24161699

Love and Literacy: What Happens in Couples when the Woman Learns to Read

ERIC Educational Resources Information Center

Garland, Rebecca J.

2009-01-01

Approximately fourteen percent of English-speaking Americans are functionally illiterate. Given this high figure, it is important to understand the barriers that undereducated adults face when they decide to return to school to improve their literacy skills. This qualitative study examines spousal support as one of these barriers. Through…

A randomized, clinical trial of education or motivational-interviewing-based coaching compared to usual care to improve cancer pain management.

PubMed

Thomas, Mary Laudon; Elliott, Janette E; Rao, Stephen M; Fahey, Kathleen F; Paul, Steven M; Miaskowski, Christine

2012-01-01

To test the effectiveness of two interventions compared to usual care in decreasing attitudinal barriers to cancer pain management, decreasing pain intensity, and improving functional status and quality of life (QOL). Randomized clinical trial. Six outpatient oncology clinics (three Veterans Affairs [VA] facilities, one county hospital, and one community-based practice in California, and one VA clinic in New Jersey)Sample: 318 adults with various types of cancer-related pain. Patients were randomly assigned to one of three groups: control, standardized education, or coaching. Patients in the education and coaching groups viewed a video and received a pamphlet on managing cancer pain. In addition, patients in the coaching group participated in four telephone sessions with an advanced practice nurse interventionist using motivational interviewing techniques to decrease attitudinal barriers to cancer pain management. Questionnaires were completed at baseline and six weeks after the final telephone calls. Analysis of covariance was used to evaluate for differences in study outcomes among the three groups. Pain intensity, pain relief, pain interference, attitudinal barriers, functional status, and QOL. Attitudinal barrier scores did not change over time among groups. Patients randomized to the coaching group reported significant improvement in their ratings of pain-related interference with function, as well as general health, vitality, and mental health. Although additional evaluation is needed, coaching may be a useful strategy to help patients decrease attitudinal barriers toward cancer pain management and to better manage their cancer pain. By using motivational interviewing techniques, advanced practice oncology nurses can help patients develop an appropriate plan of care to decrease pain and other symptoms.

Interorganisational Integration: Healthcare Professionals’ Perspectives on Barriers and Facilitators within the Danish Healthcare System

PubMed Central

Godtfredsen, Nina Skavlan; Frølich, Anne

2016-01-01

Introduction: Despite many initiatives to improve coordination of patient pathways and intersectoral cooperation, Danish health care is still fragmented, lacking intra- and interorganisational integration. This study explores barriers to and facilitators of interorganisational integration as perceived by healthcare professionals caring for patients with chronic obstructive pulmonary disease within the Danish healthcare system. Methods: Seven focus groups were conducted in January through July 2014 with 21 informants from general practice, local healthcare centres and a pulmonary department at a university hospital in the Capital Region of Denmark. Results and discussion: Our results can be grouped into five influencing areas for interorganisational integration: communication/information transfer, committed leadership, patient engagement, the role and competencies of the general practitioner and organisational culture. Proposed solutions to barriers in each area hold the potential to improve care integration as experienced by individuals responsible for supporting and facilitating it. Barriers and facilitators to integrating care relate to clinical, professional, functional and normative integration. Especially, clinical, functional and normative integration seems fundamental to developing integrated care in practice from the perspective of healthcare professionals. PMID:27616948

Multifactorial skin barrier deficiency and atopic dermatitis: Essential topics to prevent the atopic march.

PubMed

Egawa, Gyohei; Kabashima, Kenji

2016-08-01

Atopic dermatitis (AD) is the most common inflammatory skin disease in the industrialized world and has multiple causes. Over the past decade, data from both experimental models and patients have highlighted the primary pathogenic role of skin barrier deficiency in patients with AD. Increased access of environmental agents into the skin results in chronic inflammation and contributes to the systemic "atopic (allergic) march." In addition, persistent skin inflammation further attenuates skin barrier function, resulting in a positive feedback loop between the skin epithelium and the immune system that drives pathology. Understanding the mechanisms of skin barrier maintenance is essential for improving management of AD and limiting downstream atopic manifestations. In this article we review the latest developments in our understanding of the pathomechanisms of skin barrier deficiency, with a particular focus on the formation of the stratum corneum, the outermost layer of the skin, which contributes significantly to skin barrier function. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Characterization of the interaction between two food aroma components, alpha-pinene and ethyl butyrate, and ethylene-vinyl alcohol copolymer (EVOH) packaging films as a function of environmental humidity.

PubMed

López-Carballo, Gracia; Cava, David; Lagarón, Jose M; Catalá, Ramón; Gavara, Rafael

2005-09-07

The ethylene-vinyl alcohol copolymers (EVOHs) are well-known high oxygen barrier materials that are being used successfully in the design of packaging structures for oxygen-sensitive food or pharmaceutical products. Recently, there has been increasing interest in using EVOH materials to provide a high barrier to organic compounds as a means to reduce food aroma scalping. However, the barrier function of this family of materials diminishes significantly in humid environments, and it is supposed that so does the organic vapor barrier. In this work, a new sorption-based method to characterize the interaction between food aroma and polymer films for packaging as a function of relative humidity is presented and is used to determine the barrier to ethyl butyrate and alpha-pinene of EVOH at 23 degrees C. The results show that although EVOH is an excellent barrier to food aroma when dry, a property that even improves at low relative humidity (RH), the solubility and diffusivity of the compounds tested increase dramatically with humidity at medium to high water activities. However, even in the worst case (100% RH), EVOH outperforms low-density polyethylene (LDPE) as a barrier to organic vapors at least 500,000-fold.

Adenosine A2B receptor modulates intestinal barrier function under hypoxic and ischemia/reperfusion conditions.

PubMed

Yang, Yang; Qiu, Yuan; Wang, Wensheng; Xiao, Weidong; Liang, Hongyin; Zhang, Chaojun; Yang, Hanwenbo; Teitelbaum, Daniel H; Sun, Li-Hua; Yang, Hua

2014-01-01

Intestinal barrier function failure from ischemia/reperfusion (I/R) and acute hypoxia has been implicated as a critical determinant in the predisposition to intestinal inflammation and a number of inflammatory disorders. Here, we identified the role of Adenosine A2B receptor (A2BAR) in the regulation of intestinal barrier function under I/R and acute hypoxic conditions. C57BL/6J mice were used, and were randomized into three groups: Sham, I/R, IR+PSB1115 (a specific A2BAR antagonist) groups. After surgery, the small bowel was harvested for immunohistochemical staining, RNA and protein content, and intestinal permeability analyses. Using an epithelial cell culture model, we investigated the influence of hypoxia on the epithelial function, and the role of A2BAR in the expressions of tight junction and epithelial permeability. The expressions of Claudin-1, occludin and ZO-1 were detected by RT-PCR and Western-Blot. Epithelial barrier function was assessed with transepithelial resistance (TER). The A2BAR antagonist, PSB1115, significantly increased tight junction protein expression after intestinal I/R or acute hypoxia conditions. PSB1115 also attenuated the disrupted distribution of TJ proteins. Furthermore, inhibition of A2BAR attenuated the decrease in TER induced by I/R or acute hypoxic conditions, and maintained intestinal barrier function. Antagonism of A2BAR activity improves intestinal epithelial structure and barrier function in a mouse model of intestinal I/R and a cell model of acute hypoxia. These findings support a potentially destructive role for A2BAR under intestinal I/R and acute hypoxic conditions.

Protein Homeostasis Imposes a Barrier on Functional Integration of Horizontally Transferred Genes in Bacteria.

PubMed

Bershtein, Shimon; Serohijos, Adrian W R; Bhattacharyya, Sanchari; Manhart, Michael; Choi, Jeong-Mo; Mu, Wanmeng; Zhou, Jingwen; Shakhnovich, Eugene I

2015-10-01

Horizontal gene transfer (HGT) plays a central role in bacterial evolution, yet the molecular and cellular constraints on functional integration of the foreign genes are poorly understood. Here we performed inter-species replacement of the chromosomal folA gene, encoding an essential metabolic enzyme dihydrofolate reductase (DHFR), with orthologs from 35 other mesophilic bacteria. The orthologous inter-species replacements caused a marked drop (in the range 10-90%) in bacterial growth rate despite the fact that most orthologous DHFRs are as stable as E.coli DHFR at 37°C and are more catalytically active than E. coli DHFR. Although phylogenetic distance between E. coli and orthologous DHFRs as well as their individual molecular properties correlate poorly with growth rates, the product of the intracellular DHFR abundance and catalytic activity (kcat/KM), correlates strongly with growth rates, indicating that the drop in DHFR abundance constitutes the major fitness barrier to HGT. Serial propagation of the orthologous strains for ~600 generations dramatically improved growth rates by largely alleviating the fitness barriers. Whole genome sequencing and global proteome quantification revealed that the evolved strains with the largest fitness improvements have accumulated mutations that inactivated the ATP-dependent Lon protease, causing an increase in the intracellular DHFR abundance. In one case DHFR abundance increased further due to mutations accumulated in folA promoter, but only after the lon inactivating mutations were fixed in the population. Thus, by apparently distinguishing between self and non-self proteins, protein homeostasis imposes an immediate and global barrier to the functional integration of foreign genes by decreasing the intracellular abundance of their products. Once this barrier is alleviated, more fine-tuned evolution occurs to adjust the function/expression of the transferred proteins to the constraints imposed by the intracellular environment of the host organism.

The pH-sensing receptor OGR1 improves barrier function of epithelial cells and inhibits migration in an acidic environment.

PubMed

de Vallière, Cheryl; Vidal, Solange; Clay, Ieuan; Jurisic, Giorgia; Tcymbarevich, Irina; Lang, Silvia; Ludwig, Marie-Gabrielle; Okoniewski, Michal; Eloranta, Jyrki J; Kullak-Ublick, Gerd A; Wagner, Carsten A; Rogler, Gerhard; Seuwen, Klaus

2015-09-15

The pH-sensing receptor ovarian cancer G protein-coupled receptor 1 (OGR1; GPR68) is expressed in the gut. Inflammatory bowel disease is typically associated with a decrease in local pH, which may lead to altered epithelial barrier function and subsequent gastrointestinal repair involving epithelial cell adhesion and migration. As the mechanisms underlying the response to pH changes are not well understood, we have investigated OGR1-mediated, pH-dependent signaling pathways in intestinal epithelial cells. Caco-2 cells stably overexpressing OGR1 were created and validated as tools to study OGR1 signaling. Barrier function, migration, and proliferation were measured using electric cell-substrate impedance-sensing technology. Localization of the tight junction proteins zonula occludens protein 1 and occludin and the rearrangement of cytoskeletal actin were examined by confocal microscopy. Paracellular permeability and protein and gene expression analysis using DNA microarrays were performed on filter-grown Caco-2 monolayers. We report that an acidic pH shift from pH 7.8 to 6.6 improved barrier function and stimulated reorganization of filamentous actin with prominent basal stress fiber formation. Cell migration and proliferation during in vitro wound healing were inhibited. Gene expression analysis revealed significant upregulation of genes related to cytoskeleton remodeling, cell adhesion, and growth factor signaling. We conclude that acidic extracellular pH can have a signaling function and impact the physiology of intestinal epithelial cells. The deconstruction of OGR1-dependent signaling may aid our understanding of mucosal inflammation mechanisms. Copyright © 2015 the American Physiological Society.

Rifaximin alters intestinal bacteria and prevents stress-induced gut inflammation and visceral hyperalgesia in rats.

PubMed

Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y; Owyang, Chung

2014-02-01

Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction (PCR) and 454 pyrosequencing were used to analyze bacterial 16S ribosomal RNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Improving Dispersion and Barrier Properties of Polyketone/Graphene Nanoplatelet Composites via Noncovalent Functionalization Using Aminopyrene.

PubMed

Cho, Jaehyun; Jeon, Ikseong; Kim, Seong Yun; Lim, Soonho; Jho, Jae Young

2017-08-23

A series of polyketone (PK) nanocomposite films with varying content of noncovalently functionalized graphene nanoplatelet with 1-aminopyrene (GNP/APy) is prepared by solution blending with a solvent of hexafluoro-2-propanol. GNP/APy, prepared by a facile method, can effectively induce specific interaction such as hydrogen bonding between the amine functional group of GNP/APy and the carbonyl functional group of the PK matrix. With comparison of GNP and GNP/Py as reference materials, intensive investigation on filler-matrix interaction is achieved. In addition, the dispersion state of the functionalized GNP (f-GNPs; GNP/Py and GNP/APy) in the PK matrix is analyzed by three-dimensional nondestructive X-ray microcomputed tomography, and the increased dispersion state of those fillers results in significant improvement in the water vapor transmission rate (WVTR). The enhancement in WVTR of the PK/GNP/APy nanocomposite film at 1 wt % loading of filler leads to a barrier performance approximately 2 times larger compared to that of PK/GNP nanocomposite film and an approximately 92% reduction in WVTR compared to the case of pristine PK film. We expect that this facile method of graphene functionalization to enhance graphene dispersibility as well as interfacial interaction with the polymer matrix will be widely utilized to expand the potential of graphene materials to barrier film applications.

A novel gate and drain engineered charge plasma tunnel field-effect transistor for low sub-threshold swing and ambipolar nature

NASA Astrophysics Data System (ADS)

Yadav, Dharmendra Singh; Raad, Bhagwan Ram; Sharma, Dheeraj

2016-12-01

In this paper, we focus on the improvement of figures of merit for charge plasma based tunnel field-effect transistor (TFET) in terms of ON-state current, threshold voltage, sub-threshold swing, ambipolar nature, and gate to drain capacitance which provides better channel controlling of the device with improved high frequency response at ultra-low supply voltages. Regarding this, we simultaneously employ work function engineering on the drain and gate electrode of the charge plasma TFET. The use of gate work function engineering modulates the barrier on the source/channel interface leads to improvement in the ON-state current, threshold voltage, and sub-threshold swing. Apart from this, for the first time use of work function engineering on the drain electrode increases the tunneling barrier for the flow of holes on the drain/channel interface, it results into suppression of ambipolar behavior. The lowering of gate to drain capacitance therefore enhanced high frequency parameters. Whereas, the presence of dual work functionality at the gate electrode and over the drain region improves the overall performance of the charge plasma based TFET.

Hippophae rhamnoides oil-in-water (O/W) emulsion improves barrier function in healthy human subjects.

PubMed

Khan, Barkat Ali; Akhtar, Naveed

2014-11-01

This study aimed to investigate the changes in skin barrier function in human subjects, following long-term topical application of Hippophae rhamnoides oil-in-water (O/W) emulsion whereas effects were measred using non-invasive probes like tewameter and corneometer. For this purpose, two stable oil-in-water (O/W) emulsions were formulated one with 5% Hippophae rhamnoides extract and other without extracts. Thirteen healthy, male subjects with a mean age 27 ± 4.8 years were enrolled after their informed consents. The subjects were instructed to apply either the active formulation or the base formulation over 84 days while they were not known with the contents of either formulation. Biometrological measurements of skin hydration and transepidermal water loss (TEWL) were performed on both sides of the face in each volunteer at baseline and on day 07, 14, 21, 28, 42, 56, 70 and 84. The statistical analysis revealed formulation with 5% plant extract was superior compared to placebo (base formulation) as formulation with extract have shown extremely significant improvements in skin hydration (p=0.0003) and TEWL (p=0.0087) throughout treatment course. Moreover, a significant (p<0.05) correlation between the active formulation and the improvement of the skin barrier functions was observed. The active formulation found to be superior to that of placebo. Results affirmed that future studies are necessary to clinically evaluate the active formulation hence it can be proposed that Hippophae rhamnoides emulsion could be an alternative pharmacological tool in treating barrier compromised conditions of skin.

Wild jujube polysaccharides protect against experimental inflammatory bowel disease by enabling enhanced intestinal barrier function.

PubMed

Yue, Yuan; Wu, Shuangchan; Li, Zhike; Li, Jian; Li, Xiaofei; Xiang, Jin; Ding, Hong

2015-08-01

Dietary polysaccharides provide various beneficial effects for our health. We investigated the protective effects of wild jujube (Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou) sarcocarp polysaccharides (WJPs) against experimental inflammatory bowel disease (IBD) by enabling enhanced intestinal barrier function. Colitis was induced in rats by the intrarectal administration of TNBS. We found that WJPs markedly ameliorated the colitis severity, including less weight loss, decreased disease activity index scores, and improved mucosal damage in colitis rats. Moreover, WJPs suppressed the inflammatory response via attenuation of TNF-α, IL-1β, IL-6 and MPO activity in colitis rats. And then, to determine the effect of WJPs on the intestinal barrier, we measured the effect of WJPs on the transepithelial electrical resistance (TER) and FITC-conjugated dextran permeability in Caco-2 cell stimulation with TNF-α. We further demonstrated that the alleviation of WJPs to colon injury was associated with barrier function by assembly of tight junction proteins. Moreover, the effect of WJPs on TER was eliminated by the specific inhibitor of AMPK. AMPK activity was also up-regulated by WJPs in Caco-2 cell stimulation with TNF-α and in colitis rats. This study demonstrates that WJPs protect against IBD by enabling enhanced intestinal barrier function involving the activation of AMPK.

Gentle cleansing and moisturizing for patients with atopic dermatitis and sensitive skin.

PubMed

Cheong, Wai Kwong

2009-01-01

Atopic dermatitis is a common condition characterized by pruritus, inflammation, and dryness of the skin. Inflammation disrupts the barrier function of the stratum corneum, predisposing the skin to be dry, and increases susceptibility to irritants and secondary bacterial infection. Sensitive skin is common, reported by 40-50% of women and 30% of men in the US, Europe, and Japan. Basic requirements in managing eczema and sensitive skin include effective cleansers that do not compromise skin barrier integrity, alleviation of skin dryness, and restoration of skin barrier function through the use of therapeutic moisturizers. The selection of a skin cleanser is therefore an important part of managing these conditions. Studies have reported clinical improvement with the use of soap-free cleansers in combination with topical treatments. While topical corticosteroids and immunosuppressive agents are mainstays of treatment for atopic dermatitis, therapeutic moisturizers are important adjuncts. Moisturizers improve skin hydration, reduce susceptibility to irritation, restore the integrity of the stratum corneum, and enhance the efficacy of topical corticosteroids.

Surfactants have multi-fold effects on skin barrier function.

PubMed

Lemery, Emmanuelle; Briançon, Stéphanie; Chevalier, Yves; Oddos, Thierry; Gohier, Annie; Boyron, Olivier; Bolzinger, Marie-Alexandrine

2015-01-01

The stratum corneum (SC) is responsible for the barrier properties of the skin and the role of intercorneocyte skin lipids, particularly their structural organization, in controlling SC permeability is acknowledged. Upon contacting the skin, surfactants interact with the SC components leading to barrier damage. To improve knowledge of the effect of several classes of surfactant on skin barrier function at three different levels. The influence of treatments of human skin explants with six non-ionic and four ionic surfactant solutions on the physicochemical properties of skin was investigated. Skin surface wettability and polarity were assessed through contact angle measurements. Infrared spectroscopy allowed monitoring the SC lipid organization. The lipid extraction potency of surfactants was evaluated thanks to HPLC-ELSD assays. One anionic and one cationic surfactant increased the skin polarity by removing the sebaceous and epidermal lipids and by disturbing the organization of the lipid matrix. Another cationic surfactant displayed a detergency effect without disturbing the skin barrier. Several non-ionic surfactants disturbed the lipid matrix organization and modified the skin wettability without any extraction of the skin lipids. Finally two non-ionic surfactants did not show any effect on the investigated parameters or on the skin barrier. The polarity, the organization of the lipid matrix and the lipid composition of the skin allowed describing finely how surfactants can interact with the skin and disturb the skin barrier function.

A new DFT functional based on spin-states and SN2 barriers

NASA Astrophysics Data System (ADS)

Swart, M.; Solà, M.; Bickelhaupt, F. M.

2012-12-01

We recently reported a study into what causes the dramatic differences between OPBE and PBE for reaction barriers, spin-state energies, hydrogen-bonding and π-π stacking energies.1 It was achieved by smoothly switching from OPBE to PBE at a predefined point P of the reduced density gradient s. By letting the point P run as function of the reduced density gradient s, with values from s=0.1 to s=10, we could determine which part of the exchange functional determines its behavior for the different interactions. Based on the thus obtained results, we created a new exchange functional that showed the good results of OPBE for reaction barriers and spin-state energies, and combined it with the good (H-bonds) and reasonable (π-stacking) results of PBE for weak interactions. In other words, it combined the best of OPBE with the best of PBE. Encouraged by these good results, we have further improved the new exchange functional and fine-tuned its parameters.2 Similar to the switched functional from ref. 1, our new SSB functional2 works well for SN2 barriers (see e.g. ref. 3), spin states and H-bonding interactions. Moreover, by including Grimme's dispersion corrections4,5 (to give our final SSB-D functional) it also works well for π-π stacking interactions.2 In summary, we have constructed a new GGA exchange functional that when combined with the sPBE correlation functional6 gives the correct spin ground-state of iron complexes, and small deviations for SN2 barriers (2.7 kcalṡmol-1), geometries (0.005 Å), Hbond distances (0.012 Å), weak interactions (S22 set, 0.5 kcalṡmol-1), and transition-metal ligand distances (0.008 Å).

Spin accumulation in Si channels using CoFe/MgO/Si and CoFe/AlO{sub x}/Si tunnel contacts with high quality tunnel barriers prepared by radical-oxygen annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akushichi, T., E-mail: taiju.aku7@isl.titech.ac.jp; Shuto, Y.; Sugahara, S., E-mail: sugahara@isl.titech.ac.jp

We investigate spin injection into Si channels using three-terminal spin-accumulation (3T-SA) devices with high-quality CoFe/MgO/n-Si and CoFe/AlO{sub x}/n-Si tunnel spin-injectors whose tunnel barriers are formed by radical oxidation of Mg and Al thin films deposited on Si(100) substrates and successive annealing under radical-oxygen exposure. When the MgO and AlO{sub x} barriers are not treated by the radical-oxygen annealing, the Hanle-effect signals obtained from the 3T-SA devices are closely fitted by a single Lorentz function representing a signal due to trap spins. On the other hand, when the tunnel barriers are annealed under radical-oxygen exposure, the Hanle-effect signals can be accuratelymore » fitted by the superposition of a Lorentz function and a non-Lorentz function representing a signal due to accumulated spins in the Si channel. These results suggest that the quality improvement of tunnel barriers treated by radical-oxygen annealing is highly effective for spin-injection into Si channels.« less

"Not Another Team!" School Improvement Infrastructure Viewed through the Lens of Addressing Barriers to Learning and Teaching. A Center Policy & Practice Brief

ERIC Educational Resources Information Center

Center for Mental Health in Schools at UCLA, 2011

2011-01-01

This brief underscores the need to rethink the proliferation of school teams, work groups, and committees. While such mechanisms are essential to enhancing school improvement, they must be designed in a delimited way to carry out fundamental functions and must be fully integrated with each other. From a functional perspective, because of current…

A precise mass function in the excursion set approach

NASA Astrophysics Data System (ADS)

Del Popolo, Antonino

2017-04-01

In the present paper, using previous results from Del Popolo papers, we show how the mass function evolution can be obtained in the framework of a spherical collapse model, which has been modified to take account of dynamical friction, the cosmological constant, and angular momentum which proto-structures acquire through tidal interaction with neighbouring ones. We found an improved barrier which is in excellent agreement with simulations. The quoted barrier is used to calculated the mass function. In the case of the ΛCDM paradigm, our mass function is in good agreement (within some %) with the mass function of Klypin's Bolshoi simulation for the virial mass range 5 × 109 - 5 × 1014h-1M⊙, and 0 ≾ z ≿ 10. Similar agreement is obtained with Tinker's mass function, and Castorina's simulations.

Mobile Technologies for the Surgical Pathologist.

PubMed

Hartman, Douglas J

2015-06-01

Recent advances in hardware and computing power contained within mobile devices have made it possible to use these devices to improve and enhance pathologist workflow. This article discusses the possible uses ranging from basic functions to intermediate functions to advanced functions. Barriers to implementation are also discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of glyceryl glucoside on AQP3 expression, barrier function and hydration of human skin.

PubMed

Schrader, A; Siefken, W; Kueper, T; Breitenbach, U; Gatermann, C; Sperling, G; Biernoth, T; Scherner, C; Stäb, F; Wenck, H; Wittern, K-P; Blatt, T

2012-01-01

Aquaporins (AQPs) present in the epidermis are essential hydration-regulating elements controlling cellular water and glycerol transport. In this study, the potential of glyceryl glucoside [GG; alpha-D-glucopyranosyl-alpha-(1->2)-glycerol], an enhanced glycerol derivative, to increase the expression of AQP3 in vitro and ex vivo was evaluated. In vitro studies with real-time RT-PCR and FACS measurements were performed to test the induction by GG (3% w/v) of AQP3 mRNA and protein in cultured human keratinocytes. GG-containing formulations were applied topically to volunteer subjects and suction blister biopsies were analyzed to assess whether GG (5%) could penetrate the epidermis of intact skin, and subsequently upregulate AQP3 mRNA expression and improve barrier function. AQP3 mRNA and protein levels were significantly increased in cultured human keratinocytes. In the studies on volunteer subjects, GG significantly increased AQP3 mRNA levels in the skin and reduced transepidermal water loss compared with vehicle-controlled areas. GG promotes AQP3 mRNA and protein upregulation and improves skin barrier function, and may thus offer an effective treatment option for dehydrated skin. Copyright © 2012 S. Karger AG, Basel.

Myosin light chain kinase knockout improves gut barrier function and confers a survival advantage in polymicrobial sepsis.

PubMed

Lorentz, C Adam; Liang, Zhe; Meng, Mei; Chen, Ching-Wen; Yoseph, Benyam P; Breed, Elise R; Mittal, Rohit; Klingensmith, Nathan J; Farris, Alton B; Burd, Eileen M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

2017-06-07

Sepsis-induced intestinal hyperpermeability is mediated by disruption of the epithelial tight junction, which is closely associated with the peri-junctional actin-myosin ring. Myosin light chain kinase (MLCK) phosphorylates the myosin regulatory light chain, resulting in increased permeability. The purpose of this study was to determine whether genetic deletion of MLCK would alter gut barrier function and survival from sepsis. MLCK -/- and wild type (WT) mice were subjected to cecal ligation and puncture and assayed for both survival and mechanistic studies. Survival was significantly increased in MLCK -/- mice (95% vs. 24%, p<0.0001). Intestinal permeability increased in septic WT mice compared to unmanipulated mice. In contrast, permeability in septic MLCK -/- mice was similar to that seen in unmanipulated animals. Improved gut barrier function in MLCK -/- mice was associated with increases in the tight junction mediators ZO-1 and claudin 15 without alterations in claudin 1, 2, 3, 4, 5, 7, 8, 13, occludin or JAM-A. Other components of intestinal integrity (apoptosis, proliferation and villus length) were unaffected by MLCK deletion as were local peritoneal inflammation and distant lung injury. Systemic IL-10 was decreased greater than 10-fold in MLCK -/- mice; however, survival was similar between septic MLCK -/- mice given exogenous IL-10 or vehicle. These data demonstrate that deletion of MLCK improves survival following sepsis, associated with normalization of intestinal permeability and selected tight junction proteins.

Changes in Ocular Surface Characteristics after Switching from Benzalkonium Chloride-Preserved Latanoprost to Preservative-Free Tafluprost or Benzalkonium Chloride-Preserved Tafluprost.

PubMed

Tokuda, Naoto; Kitaoka, Yasushi; Matsuzawa, Akiko; Tsukamoto, Ayaka; Sase, Kana; Sakae, Shinsuke; Takagi, Hitoshi

2017-01-01

The aim of the present study was to examine the effects of switching from Latanoprost ophthalmic solution containing a preservative to preservative-free Tafluprost ophthalmic solution or Tafluprost containing a preservative on ocular surfaces. Forty patients (40 eyes) with glaucoma (mean age: 62.0 ± 10.9 years) using Latanoprost with preservative for six months or longer were assigned either to a Tafluprost-containing-preservative group (20 eyes) or preservative-free-Tafluprost group (20 eyes). The intraocular pressure, corneal epithelial barrier function (fluorescein uptake concentration with fluorophotometer FL-500), superficial punctate keratopathy (AD classification), and tear film breakup time (TBUT) were assessed before switching and at 12 weeks after switching. No significant differences in intraocular pressure were noted after switching in either group. Corneal epithelial barrier function was improved significantly after switching in both the Tafluprost-containing-preservative and the preservative-free-Tafluprost groups. There were no significant differences in AD scores after switching in the Tafluprost-containing-preservative group, but significant improvements were noted in the preservative-free-Tafluprost group. No significant differences in TBUT were noted in the Tafluprost-containing-preservative or preservative-free-Tafluprost groups after switching. After switching from preservative Latanoprost to Tafluprost containing-preservative or preservative-free Tafluprost, corneal epithelial barrier function was improved while the intraocular pressure reduction was retained.

"It's good for me": physical activity in older adults with schizophrenia.

PubMed

Leutwyler, Heather; Hubbard, Erin M; Slater, Margaret; Jeste, Dilip V

2014-01-01

Physical activity (PA) interventions to improve the physical function of older adults with schizophrenia are necessary but not available. Older adults with schizophrenia may have unique barriers and facilitators to PA. The purpose of this study was to describe the perceptions of older adults with schizophrenia about barriers and facilitators to engage in physical activities that promote physical function. We conducted qualitative interviews with 16 older adults with schizophrenia. Data were collected and analyzed with grounded theory methodology. Participants expressed interest in becoming more physically active for a variety of perceived benefits including psychiatric symptom management and maintenance of basic function. Key barriers and facilitators to PA emerged in five broad categories: Mental Health, No longer a spring chicken, Pride and Sense of Well-being, Comfort and Safety, and Belonging. Interventions in this population should address negative attitudes towards aging and promote routine physical activities that enhance well-being and companionship.

Glutamine supplementation improves intestinal barrier function in a weaned piglet model of Escherichia coli infection.

PubMed

Ewaschuk, Julia B; Murdoch, Gordon K; Johnson, Ian R; Madsen, Karen L; Field, Catherine J

2011-09-01

The weaning period is associated with an increased prevalence of gastrointestinal infection in many species. Glutamine (Gln) has been shown to improve intestinal barrier function and immune function in both in vivo and in vitro models. The objective of the present study was to determine the effect of dietary Gln supplementation on intestinal barrier function and intestinal cytokines in a model of Escherichia coli infection. We randomised 21-d-old piglets (n 20) to nutritionally complete isonitrogenous diets with or without Gln (4·4 %, w/w) for 2 weeks. Intestinal loops were isolated from anaesthetised pigs and inoculated with either saline or one of the two E. coli (K88AC or K88 wild-type)-containing solutions. Intestinal tissue was studied for permeability, cytokine expression, fluid secretion and tight-junction protein expression. Animals receiving Gln supplementation had decreased potential difference (PD) and short-circuit current (I(sc)) in E. coli-inoculated intestinal loops (PD 0·628 (SEM 0·151) mV; I(sc) 13·0 (SEM 3·07) μA/cm(2)) compared with control-fed animals (PD 1·36 (SEM 0·227) mV; I(sc) 22·4 (SEM 2·24) μA/cm(2)). Intestinal tissue from control, but not from Gln-supplemented, animals responded to E. coli with a significant increase in mucosal cytokine mRNA (IL-1β, IL-6, transforming growth factor-β and IL-10). Tight-junction protein expression (claudin-1 and occludin) was reduced with exposure to E. coli in control-fed animals and was not influenced in Gln-supplemented piglets. Gln supplementation may be useful in reducing the severity of weaning-related gastrointestinal infections, by reducing the mucosal cytokine response and altering intestinal barrier function.

Efficacy of a shower cream and a lotion with skin-identical lipids in healthy subjects with atopic dry skin.

PubMed

Berardesca, Enzo; Mortillo, Susan; Cameli, Norma; Ardigo, Marco; Mariano, Maria

2018-05-10

Atopic dermatitis is a chronic, pruritic inflammatory skin disease that adversely affects quality of life. The current study evaluates the efficacy of a shower cream and a lotion, each with skin-identical lipids and emollients, in the treatment of atopic dry skin of subjects with a history of atopic condition. In all, 40 healthy females with clinically dry skin on the lower legs were enrolled in the study and underwent 4 weeks of daily use of the shower cream and 2 additional weeks of both the shower cream and the body lotion. Subjects were evaluated at day 0, week 4, and week 6. Skin barrier function was assessed by Tewameter ® , skin hydration by Corneometer ® , smoothness and desquamation by Visioscan ® , and stratum corneum architecture by reflectance confocal microscopy (RCM). The investigator assessed the degree of dryness, roughness, redness, cracks, tingling and itch, and subjective self-assessment evaluated the perception of skin soothing, smoothness, and softness. Skin barrier function and skin moisture maintenance were significantly improved using the shower cream. The lotion with physiological lipids, together with the shower cream, also improved skin barrier function and moisture. Both the shower cream and the body lotion reduced clinical dryness, roughness, redness, cracks, tingling and itch, according to the dermatologist, and increased soothing, smoothness, and softness, according to the subjects of the study. The combination of a shower cream and a lotion with physiological lipids efficiently restores skin barrier function and increases skin hydration, becoming an effective skin-care option for patients with atopic dry skin. © 2018 Wiley Periodicals, Inc.

Blood-brain barrier and its function during inflammation and autoimmunity.

PubMed

Sonar, Sandip Ashok; Lal, Girdhari

2018-05-01

The blood-brain barrier (BBB) is an important physiologic barrier that separates CNS from soluble inflammatory mediators and effector immune cells from peripheral circulation. The optimum function of the BBB is necessary for the homeostasis, maintenance, and proper neuronal function. The clinical and experimental findings have shown that BBB dysfunction is an early hallmark of various neurologic disorders ranging from inflammatory autoimmune, neurodegenerative, and traumatic diseases to neuroinvasive infections. Significant progress has been made in the understanding of the regulation of BBB function under homeostatic and neuroinflammatory conditions. Several neurologic disease-modifying drugs have shown to improve the BBB function. However, they have a broad-acting immunomodulatory function and can increase the risk of life-threatening infections. The recent development of in vitro multicomponent 3-dimensional BBB models coupled with fluidics chamber as well as a cell-type specific reporter and knockout mice gave a new boost to our understanding of the dynamics of the BBB. In the review, we discuss the current understanding of BBB composition and recent findings that illustrate the critical regulatory elements of the BBB function under physiologic and inflammatory conditions, and also suggested the strategies to control BBB structure and function. ©2018 Society for Leukocyte Biology.

Breaking through barriers: using technology to address executive function weaknesses and improve student achievement.

PubMed

Schwartz, David M

2014-01-01

Assistive technologies provide significant capabilities for improving student achievement. Improved accessibility, cost, and diversity of applications make integration of technology a powerful tool to compensate for executive function weaknesses and deficits and their impact on student performance, learning, and achievement. These tools can be used to compensate for decreased working memory, poor time management, poor planning and organization, poor initiation, and decreased memory. Assistive technology provides mechanisms to assist students with diverse strengths and weaknesses in mastering core curricular concepts.

Tissue response to five commercially available peritoneal adhesion barriers-A systematic histological evaluation.

PubMed

Schmitt, Volker H; Mamilos, Andreas; Schmitt, Christine; Neitzer-Planck, Constanze N E; Rajab, Taufiek K; Hollemann, David; Wagner, Willi; Krämer, Bernhard; Hierlemann, Helmut; James Kirkpatrick, C; Brochhausen, Christoph

2018-02-01

Separating wounded serosa by physical barriers is the only clinically approved adjunct for postoperative adhesion prevention. Since the optimal adhesion barrier has not been found, it is essential to improve our pathogenic understanding of adhesion formation and to compare the effects of different barrier materials on tissue and cells. Wistar rats underwent standardized peritoneal damage and were treated either with Seprafilm, Adept, Intercoat, Spraygel, SupraSeal or remained untreated as a control. 14 days postoperatively, the lesions were explanted and histomorphologically analyzed using the European ISO score to evaluate material implants. Striking differences between the material groups were present regarding the inflammation, fibrosis, and foreign body reaction. According to the ISO score, Intercoat and Spraygel were considered as nonirritating to tissue. Adept, Seprafilm, and SupraSeal were assessed as mild-irritating materials. Interestingly, the most effective material in adhesion prevention revealed moderate inflammation accompanied by minor fibrosis. The degree of inflammation to barrier materials does not predict the efficacy in the prevention of adhesions. Histopathological investigations are crucial to improve our understanding of the cellular mechanisms during adhesion formation and elucidate the tissue response to material approaches used in adhesion prevention. This will lead to improved antiadhesive strategies and the development of functional barrier biomaterials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 598-609, 2018. © 2017 Wiley Periodicals, Inc.

Modulation of Gastrointestinal Barrier and Nutrient Transport Function in Farm Animals by Natural Plant Bioactive Compounds - A Comprehensive Review.

PubMed

Patra, Amlan Kumar; Amasheh, Salah; Aschenbach, Jörg Rudolf

2018-06-11

The use of antibiotics in diets has been restricted in several countries as a precautionary measure to avoid development of antibiotic resistance among pathogenic microorganisms. This regulation promoted the exploration of natural plant bioactive compounds (PBCs) as feed additives to improve productivity, welfare and health of livestock and poultry. Along with several beneficial attributes of PBCs, including antimicrobial, antioxidant and various pharmacological effects, they also improve barrier function and nutrient transport in the gastrointestinal (GI) tract. This comprehensive review discusses the effects of different PBCs on the integrity, nutrient transport and permeability of GI epithelia and their mechanism of actions. Dietary PBCs influence the maintenance and enhancement of GI integrity via a number of mechanisms including altered signaling pathways and expression of several tight junction proteins (claudins, occludin, and zonula occludens proteins), altered expression of various cytokines, chemokines, complement components and their transcription factors, goblet cell abundance and mucin gene expression, and the modulation of the cellular immune system. They also affect nutrient transporter gene expression and active absorption of nutrients, minerals and ammonia. One intriguing perspective is to select an effective dose at which a specific PBC could improve GI barrier function and nutrient absorption. The effective doses and clear-cut molecular mechanisms for PBCs are yet to be elucidated to understand discrepant observations among different studies and to improve the targeted biotechnological and pharmaceutical uses of PBCs in farm animals. The latter will also enable a more successful use of such PBCs in humans.

Thermal acclimation mitigates cold-induced paracellular leak from the Drosophila gut.

PubMed

MacMillan, Heath A; Yerushalmi, Gil Y; Jonusaite, Sima; Kelly, Scott P; Donini, Andrew

2017-08-18

Chill susceptible insects suffer tissue damage and die at low temperatures. The mechanisms that cause chilling injury are not well understood but a growing body of evidence suggests that a cold-induced loss of ion and water homeostasis leads to hemolymph hyperkalemia that depolarizes cells, leading to cell death. The apparent root of this cascade is the net leak of osmolytes down their concentration gradients in the cold. Many insects, however, are capable of adjusting their thermal physiology, and cold-acclimated Drosophila can maintain homeostasis and avoid injury better than warm-acclimated flies. Here, we test whether chilling causes a loss of epithelial barrier function in female adult Drosophila, and provide the first evidence of cold-induced epithelial barrier failure in an invertebrate. Flies had increased rates of paracellular leak through the gut epithelia at 0 °C, but cold acclimation reduced paracellular permeability and improved cold tolerance. Improved barrier function was associated with changes in the abundance of select septate junction proteins and the appearance of a tortuous ultrastructure in subapical intercellular regions of contact between adjacent midgut epithelial cells. Thus, cold causes paracellular leak in a chill susceptible insect and cold acclimation can mitigate this effect through changes in the composition and structure of transepithelial barriers.

Benefits, barriers and opinions on multidisciplinary team meetings: a survey in Swedish cancer care.

PubMed

Rosell, Linn; Alexandersson, Nathalie; Hagberg, Oskar; Nilbert, Mef

2018-04-05

Case review and discussion at multidisciplinary team meetings (MDTMs) have evolved into standard practice in cancer care with the aim to provide evidence-based treatment recommendations. As a basis for work to optimize the MDTMs, we investigated participants' views on the meeting function, including perceived benefits and barriers. In a cross-sectional study design, 244 health professionals from south Sweden rated MDTM meeting structure and function, benefits from these meetings and barriers to reach a treatment recommendation. The top-ranked advantages from MDTMs were support for patient management and competence development. Low ratings applied to monitoring patients for clinical trial inclusion and structured work to improve the MDTM. Nurses and cancer care coordinators did less often than physicians report involvement in the case discussions. Major benefits from MDTM were reported to be more accurate treatment recommendations, multidisciplinary evaluation and adherence to clinical guidelines. Major barriers to a joint treatment recommendation were reported to be need for supplementary investigations and insufficient pathology reports. Health professionals' report multiple benefits from MDTMs, but also define areas for improvement, e.g. access to complete information and clarified roles for the different health professions. The emerging picture suggests that structures for regular MDTM evaluations and increased focus on patient-related perspectives should be developed and implemented.

FISH OIL IMPROVES MOTOR FUNCTION, LIMITS BLOOD-BRAIN BARRIER DISRUPTION, AND REDUCES MMP9 GENE EXPRESSION IN A RAT MODEL OF JUVENILE TRAUMATIC BRAIN INJURY

PubMed Central

Russell, K. L.; Berman, N. E. J.; Gregg, P. R. A.; Levant, B.

2014-01-01

SUMMARY The effects of an oral fish oil treatment regimen on sensorimotor, blood-brain barrier, and biochemical outcomes of traumatic brain injury (TBI) were investigated in a juvenile rat model. Seventeen-day old Long-Evans rats were given a 15 mL/kg fish oil (2.01 g/kg EPA, 1.34 g/kg DHA) or soybean oil dose via oral gavage 30 minutes prior to being subjected to a controlled cortical impact injury or sham surgery, followed by daily doses for seven days. Fish oil treatment resulted in less severe hindlimb deficits after TBI as assessed with the beam walk test, decreased cerebral IgG infiltration, and decreased TBI-induced expression of the Mmp9h gene one day after injury. These results indicate that fish oil improved functional outcome after TBI resulting, at least in part from decreased disruption of the blood-brain barrier through a mechanism that includes attenuation of TBI-induced expression of Mmp9. PMID:24342130

Fish oil improves motor function, limits blood-brain barrier disruption, and reduces Mmp9 gene expression in a rat model of juvenile traumatic brain injury.

PubMed

Russell, K L; Berman, N E J; Gregg, P R A; Levant, B

2014-01-01

The effects of an oral fish oil treatment regimen on sensorimotor, blood-brain barrier, and biochemical outcomes of traumatic brain injury (TBI) were investigated in a juvenile rat model. Seventeen-day old Long-Evans rats were given a 15mL/kg fish oil (2.01g/kg EPA, 1.34g/kg DHA) or soybean oil dose via oral gavage 30min prior to being subjected to a controlled cortical impact injury or sham surgery, followed by daily doses for seven days. Fish oil treatment resulted in less severe hindlimb deficits after TBI as assessed with the beam walk test, decreased cerebral IgG infiltration, and decreased TBI-induced expression of the Mmp9 gene one day after injury. These results indicate that fish oil improved functional outcome after TBI resulting, at least in part from decreased disruption of the blood-brain barrier through a mechanism that includes attenuation of TBI-induced expression of Mmp9. © 2013 Elsevier Ltd. All rights reserved.

Antibacterial [2-(Methacryloyloxy) ethyl] Trimethylammonium Chloride Functionalized Reduced Graphene Oxide/Poly(ethylene-co-vinyl alcohol) Multilayer Barrier Film for Food Packaging.

PubMed

Wang, Hualin; Chen, Minmin; Jin, Chongyang; Niu, Baicheng; Jiang, Suwei; Li, Xingjiang; Jiang, Shaotong

2018-01-24

The objective of present work was to construct antibacterial [2-(methacryloyloxy) ethyl] trimethylammonium chloride functionalized reduced graphene oxide/poly(ethylene-co-vinyl alcohol) (MTAC-rGO/EVOH) multilayer barrier films by using layer-by-layer assembly under a parallel electric field. Besides barrier and mechanical properties, the antibacterial activities of the film and cytotoxicity of MTAC-rGO nanosheets were extensively investigated. The functionalization of rGO was achieved by grafting MTAC onto a graphene framework through C (sp 3 )-C bonds. The assembly of MTAC-rGO on the EVOH matrix not only significantly improved film mechanical strength, but also endowed the targeting film with outstanding moisture barrier even under a relative humidity of 99% (e.g., 0.019 g m -2 s -1 atm -1 for (MTAC-rGO/EVOH) 20 ) besides good oxygen barrier (e.g., 0.07 cm 3 m -2 d -1 atm -1 for (MTAC-rGO/EVOH) 20 ). Among the testing films, MTAC-rGO/EVOH film had the best antibacterial activity, and the activity against S. aureus was better than E. coli. Meanwhile, the cytotoxicity of MTAC-rGO nanosheets was very low. Results suggest that MTAC-rGO/EVOH film may have great potential in food active packaging.

Lactobacillus frumenti Facilitates Intestinal Epithelial Barrier Function Maintenance in Early-Weaned Piglets

PubMed Central

Hu, Jun; Chen, Lingli; Zheng, Wenyong; Shi, Min; Liu, Liu; Xie, Chunlin; Wang, Xinkai; Niu, Yaorong; Hou, Qiliang; Xu, Xiaofan; Xu, Baoyang; Tang, Yimei; Zhou, Shuyi; Yan, Yiqin; Yang, Tao; Ma, Libao; Yan, Xianghua

2018-01-01

Increased intestinal epithelial barrier function damages caused by early weaning stress have adverse effects on swine health and feed utilization efficiency. Probiotics have emerged as the promising antibiotic alternatives used for intestinal barrier function damage prevention. Our previous data showed that Lactobacillus frumenti was identified as a predominant Lactobacillus in the intestinal microbiota of weaned piglets. However, whether the intestinal epithelial barrier function in piglets was regulated by L. frumenti is still unclear. Here, piglets received a PBS vehicle or PBS suspension (2 ml, 108 CFU/ml) containing the L. frumenti by oral gavage once a day during the period of 6–20 days of age prior to early weaning. Our data demonstrated that oral administration of L. frumenti significantly improved the intestinal mucosal integrity and decreased the serum endotoxin and D-lactic acid levels in early-weaned piglets (26 days of age). The intestinal tight junction proteins (including ZO-1, Occludin, and Claudin-1) were significantly up-regulated by L. frumenti administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, and interferon-γ (IFN-γ) levels were significantly increased by L. frumenti administration. Furthermore, our data revealed that oral administration of L. frumenti significantly increased the relative abundances of health-promoting microbes (including L. frumenti, Lactobacillus gasseri LA39, Parabacteroides distasonis, and Kazachstania telluris) and decreased the relative abundances of opportunistic pathogens (including Desulfovibrio desulfuricans and Candida humilis). Functional alteration of the intestinal bacterial community by L. frumenti administration was characterized by the significantly increased fatty acids and protein metabolism and decreased diseases-associated metabolic pathways. These findings suggest that L. frumenti facilitates intestinal epithelial barrier function maintenance in early-weaned piglets and may be a promising antibiotic alternative used for intestinal epithelial barrier function damage prevention in mammals. PMID:29867808

Overview and introduction: The blood–brain barrier in health and disease

PubMed Central

Abbott, N. Joan; Friedman, Alon

2013-01-01

Summary This article introduces the special issue on “Blood–Brain Barrier and Epilepsy.” We review briefly current understanding of the structure and function of the blood–brain barrier (BBB), including its development and normal physiology, and ways in which it can be affected in pathology. The BBB formed by the endothelium of cerebral blood vessels is one of three main barrier sites protecting the central nervous system (CNS). The barrier is not a rigid structure, but a dynamic interface with a range of interrelated functions, resulting from extremely effective tight junctions, transendothelial transport systems, enzymes, and regulation of leukocyte permeation, which thereby generates the physical, transport, enzymatic, and immune regulatory functions of the BBB. The brain endothelial cells are important components of a “modular” structure, the neurovascular unit (NVU), with several associated cell types and extracellular matrix components. Modern methods have helped in identifying a range of proteins involved in barrier structure and function, and recent studies have revealed important stages, cell types, and signaling pathways important in BBB development. There is a growing list of CNS pathologies showing BBB dysfunction, with strong evidence that this can play a major role in certain disease etiologies. The articles that follow in this issue summarize in more detail reports and discussions of the recent international meeting on “BBB in Neurological Dysfunctions,” which took place recently at Ben-Gurion University of the Negev Desert Campus (Beer-Sheva, Israel), focusing on the link between experimental and clinical studies, and the ways in which these lead to improved drug treatments. PMID:23134489

Oligoclonal banding of IgG in CSF, blood-brain barrier function, and MRI findings in patients with sarcoidosis, systemic lupus erythematosus, and Behçet's disease involving the nervous system.

PubMed Central

McLean, B N; Miller, D; Thompson, E J

1995-01-01

A retrospective study of CSF and serum analysis from a total of 43 patients with sarcoidosis, 20 with systemic lupus erythematosus, and 12 with Behçet's disease with neurological involvement found local synthesis of oligoclonal IgG using isoelectric focusing and immunoblotting in 51%, 25%, and 8% respectively at some stage in their disease. Blood-brain barrier breakdown, when assessed with an albumin ratio found 47% of patients with sarcoidosis, 30% of those with systemic lupus erythematosus, and 42% of patients with Behçet's disease exhibiting abnormal barrier function at some time. Serial CSF analysis showed that clinical relapses were associated with worsening barrier function and in some patients the development of local oligoclonal IgG synthesis; conversely steroid treatment led to a statistically significant improvement in barrier function, and in two patients a loss of oligoclonal IgG bands. A higher proportion of patients had MRI abnormalities than oligoclonal IgG or blood-brain barrier breakdown, MRI being abnormal in 16 of 19 patients with sarcoidosis, three of four patients with systemic lupus erythematosus, and seven of nine patients with Behçet's disease, although this may have been due to temporal factors. In the differential diagnosis of chronic neurological disorders, locally synthesised oligoclonal IgG cannot distinguish between diseases, but the loss of bands seen in two patients contrasts with what is seen in multiple sclerosis, and thus may be a useful diagnostic clue. PMID:7745401

Imipenem and normal saline with cyclophosphamide have positive effects on the intestinal barrier in rats with sepsis.

PubMed

Yang, Junting; Zhang, Shunwen; Wu, Jiangdong; Zhang, Jie; Dong, Jiangtao; Guo, Peng; Tang, Suyu; Zhang, Wanjiang; Wu, Fang

2018-06-12

Sepsis is a life-threatening organ dysfunction caused the dysregulation of host inflammatory response and immunosuppression to infection Early recognition and intervention are hence of paramount importance. In this respect the "sepsis bundle" was proposed in 2004 to be instituted in cases of suspected sepsis. We hypothesised that a combination treatment of the sepsis bundle with cyclophosphamide would improve the function of the intestinal mucosa and enhance survival in rats with induced sepsis. Sprague-Dawley rats were divided into 5 different groups: sham, cecal ligation and puncture (CLP), cyclophosphamide (CTX), imipenem+normal saline (NS) and imipenem+NS+CTX. Cecal ligation and puncture were used for inducing the polymicrobial sepsis. Western-blot was used to measure the occludin protein, and ELISA for examining the plasma level of cytokines IL-6, IL-10 and TNF-α. TUNEL assay for testing the intestinal mucosal apoptosis, and hematoxylin-eosin staining for observing the intestinal mucosal changes. The permeability of intestinal mucosa was determined by the plasma level of FD-70. The results showed that the combination treatment of the sepsis bundle with cyclophosphamide attenuated cytokine levels, inhibited epithelial cell apoptosis and improved the function of the intestinal barrier. The survival rate of the group treated with the combined therapy was significantly higher than that of the other groups. The combination treatment of sepsis bundle with cyclophosphamide improves the function of the intestinal barrier and enhances survival in septic rats.

Hydrologic Evaluation of a Humid Climate Poplar Phytoremediation Barrier

NASA Astrophysics Data System (ADS)

Swensen, K.; Rabideau, A. J.

2016-12-01

The emplacement of hybrid poplar trees to function as phytoremediation barriers is an appealing and sustainable groundwater management strategy because of low maintenance costs and the potential to extract large amounts of groundwater without pumping. While the effectiveness of poplar barriers has been assessed by groundwater quality monitoring, less attention has been given to physical hydrologic evaluations needed to improve barrier designs. In this research, a five year hydrologic evaluation was conducted at a poplar phytoremediation site in western NY, with the goal of quantifying ETg (evapotranspiration from groundwater) as a measure of the barrier's effectiveness in a humid climate. To consider transpiration from both vadose zone and groundwater, the hydrologic evaluation included four components: physical ET measurements, theoretical ET calculations, analysis of diurnal groundwater table fluctuations, and vadose zone modeling. The direct measurements of ETT (total) were obtained using sap flow meters installed on multiple trees within the barrier. These data were interpreted using a regression model that included theoretical ET calculations and site-specific measurements of weather parameters and poplar trunk area. Application of this model was challenged by the spatial variation in rooting depth as determined by tree excavations. To further quantify the removal of groundwater by the phytobarrier (ETg), the White Method was applied to interpret diurnal groundwater fluctuations from monitoring wells located within the barrier, in conjunction with a variably saturated-saturated flow model configured to confirm water extraction from ETg. Taken together, the results of this five year hydrologic evaluation highlight the complexity in quantifying humid climate groundwater extraction, as a large number of variables were found to influence these rates. Improved understanding of these controls will contribute to improved barrier designs that maximize ETg.

A Qualitative Study of Barriers to Accessing Water, Sanitation and Hygiene for Disabled People in Malawi.

PubMed

White, Sian; Kuper, Hannah; Itimu-Phiri, Ambumulire; Holm, Rochelle; Biran, Adam

2016-01-01

Globally, millions of people lack access to improved water, sanitation and hygiene (WASH). Disabled people, disadvantaged both physically and socially, are likely to be among those facing the greatest inequities in WASH access. This study explores the WASH priorities of disabled people and uses the social model of disability and the World Health Organization's International Classification of Functioning, Disability and Health (ICF) framework to look at the relationships between impairments, contextual factors and barriers to WASH access. 36 disabled people and 15 carers from urban and rural Malawi were purposively selected through key informants. The study employed a range of qualitative methods including interviews, emotion mapping, free-listing of priorities, ranking, photo voice, observation and WASH demonstrations. A thematic analysis was conducted using nVivo 10. WASH access affected all participants and comprised almost a third of the challenges of daily living identified by disabled people. Participants reported 50 barriers which related to water and sanitation access, personal and hand hygiene, social attitudes and participation in WASH programs. No two individuals reported facing the same set of barriers. This study found that being female, being from an urban area and having limited wealth and education were likely to increase the number and intensity of the barriers faced by an individual. The social model proved useful for classifying the majority of barriers. However, this model was weaker when applied to individuals who were more seriously disabled by their body function. This study found that body function limitations such as incontinence, pain and an inability to communicate WASH needs are in and of themselves significant barriers to adequate WASH access. Understanding these access barriers is important for the WASH sector at a time when there is a global push for equitable access.

A Qualitative Study of Barriers to Accessing Water, Sanitation and Hygiene for Disabled People in Malawi

PubMed Central

Kuper, Hannah; Itimu-Phiri, Ambumulire; Holm, Rochelle; Biran, Adam

2016-01-01

Globally, millions of people lack access to improved water, sanitation and hygiene (WASH). Disabled people, disadvantaged both physically and socially, are likely to be among those facing the greatest inequities in WASH access. This study explores the WASH priorities of disabled people and uses the social model of disability and the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) framework to look at the relationships between impairments, contextual factors and barriers to WASH access. 36 disabled people and 15 carers from urban and rural Malawi were purposively selected through key informants. The study employed a range of qualitative methods including interviews, emotion mapping, free-listing of priorities, ranking, photo voice, observation and WASH demonstrations. A thematic analysis was conducted using nVivo 10. WASH access affected all participants and comprised almost a third of the challenges of daily living identified by disabled people. Participants reported 50 barriers which related to water and sanitation access, personal and hand hygiene, social attitudes and participation in WASH programs. No two individuals reported facing the same set of barriers. This study found that being female, being from an urban area and having limited wealth and education were likely to increase the number and intensity of the barriers faced by an individual. The social model proved useful for classifying the majority of barriers. However, this model was weaker when applied to individuals who were more seriously disabled by their body function. This study found that body function limitations such as incontinence, pain and an inability to communicate WASH needs are in and of themselves significant barriers to adequate WASH access. Understanding these access barriers is important for the WASH sector at a time when there is a global push for equitable access. PMID:27171520

Epidermal Permeability Barrier Recovery Is Delayed in Vitiligo-Involved Sites

PubMed Central

Liu, J.; Man, W.Y.; Lv, C.Z.; Song, S.P.; Shi, Y.J.; Elias, P.M.; Man, M.Q.

2010-01-01

Background/Objectives Prior studies have demonstrated that both the skin surface pH and epidermal permeability barrier function vary with skin pigmentation types. Although melanin deficiency is the main feature of vitiligo, alterations in cutaneous biophysical properties in vitiligo have not yet been well defined. In the present study, stratum corneum (SC) hydration, the skin surface pH and epidermal permeability barrier function in vitiligo were evaluated. Methods A total of 30 volunteers with vitiligo comprising 19 males and 11 females aged 13–51 years (mean age: 27.91 ± 2.06 years) were enrolled in this study. The skin surface pH, SC hydration, melanin/erythema index and transepidermal water loss (TEWL) were measured by respective probes connected to a Courage-Khazaka MPA5. SC integrity was determined by measuring the TEWL following each D-Squame application. The barrier recovery rate was assessed at 5 h following barrier disruption by repeated tape stripping. Results In addition to SC hydration, both melanin and erythema index were significantly lower in vitiligo lesions than in contralateral, nonlesional sites, while no difference in skin surface pH between vitiligo-involved and uninvolved areas was observed. In addition, neither the basal TEWL nor SC integrity in the involved areas differed significantly from that in the uninvolved areas. However, barrier recovery in vitiligo-involved sites was significantly delayed in comparison with uninvolved sites (40.83 ± 5.39% vs. 58.30 ± 4.71%; t = 2.441; p < 0.02). Conclusion Barrier recovery following tape stripping of the SC is delayed in vitiligo. Therefore, improvement in epidermal permeability barrier function may be an important unrecognized factor to be considered in treating patients with vitiligo. PMID:20185976

[Case managers experience improved trajectories for cancer patients after implementation of the case manager function].

PubMed

Axelsen, Karina Rahbek; Nafei, Hanne; Jakobsen, Stine Finne; Gandrup, Per; Knudsen, Janne Lehmann

2014-10-13

Case managers are increasingly used to optimize trajectories for patients. This study is based on a questionnaire among case managers in cancer care, aiming at the clarification of the function and its impact on especially patient safety, when handing over the responsibility. The results show a major variation in how the function is organized, the level of competence and the task to be handled. The responsibility has in general been narrowed to department level. Overall, the case managers believe that the function has optimized pathways for cancer patients and improved safety, but barriers persist.

Barriers and Facilitators to Implementing Functional Family Therapy in a Community Setting: Client and Practitioner Perspectives.

PubMed

McPherson, Kerri E; Kerr, Susan; Casey, Beth; Marshall, John

2017-10-01

While Functional Family Therapy (FFT) is known to be effective in addressing adolescent behavioral problems, there has been little exploration of issues relevant to its transport from the tightly controlled setting of clinical trials into routine service delivery. This study sought the views of key stakeholders, clients, and practitioners, on barriers and facilitators to the successful implementation of FFT. Undertaken in a community setting in Scotland, interviews were carried out with 12 adolescents, 14 parents/caregivers, and 6 practitioners. Results focus on: Referral process and pre-intervention contact; Engagement of families; Structure and delivery; Organizational factors. Although barriers to engagement were identified, FFT was viewed as an acceptable, appropriate and feasible intervention with the potential to improve adolescent wellbeing in 'real-world' settings. © 2017 American Association for Marriage and Family Therapy.

Fibroblast Growth Factor-Peptide Improves Barrier Function and Proliferation in Human Keratinocytes After Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Kunzhong; Tian Yeping; Yin Liangjie

2011-09-01

Purpose: Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier, protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials: Keratinocytes isolated from neonatal foreskin were grown on transwells. After being exposed to 0, 5, or 10 Gy IR, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed bymore » using transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine ([{sup 3}H]-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin {beta} burns created with a strontium applicator. Results: We found (1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA, both associated with the regulation of different proteins and levels of TJ and AJ; and (2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and [{sup 3}H]-TdR incorporation, which was associated with activation of the ERK pathway; and (3) FGF-P promoted the healing of skin {beta} burns. Conclusions: FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the healing of skin {beta} burns. FGF-P is a promising mitigator that improves the proliferation and barrier function of keratinocytes after IR.« less

Improved gut barrier function via increased threonine utilization may explain enhanced resistance to necrotizing enterocolitis in preterm pigs fed colostrum

USDA-ARS?s Scientific Manuscript database

Threonine is an essential amino acid necessary for synthesis of gut mucins that form the protective intestinal mucous layer. In premature infants, this function might be compromised leading to necrotizing enterocolitis (NEC). We hypothesized that enteral feeding with colostrum, relative to infant fo...

Influence of the Fruit Juice Carriers on the Ability of Lactobacillus plantarum DSM20205 to Improve in Vitro Intestinal Barrier Integrity and Its Probiotic Properties.

PubMed

Valero-Cases, Estefanía; Roy, Nicole C; Frutos, María José; Anderson, Rachel C

2017-07-19

This study investigates the influence of tomato and feijoa juices as fermentable carriers of Lactobacillus plantarum (LP DSM20205) on the ability of the bacterium to improve intestinal barrier function using the trans-epithelial electrical resistance (TEER) assay in an apical anaerobic model. The survival of LP DSM20205 in different fruit juices during in vitro digestion, its adhesion capacity, and potential cytotoxic effect on Caco-2 cells were also studied. The results showed that carrier fruit juices have a significant influence on LP DSM20205 growth, survival during in vitro digestion, adhesion capacity, and TEER. All fermented samples were not cytotoxic to Caco-2 cells. The fermented tomato juice showed the largest improvement to intestinal barrier integrity. The digested fermented juices did not increase TEER, although the LP DSM20205 in these samples adhered well. Therefore, LP DSM20205 has the potential to be used as a probiotic in the production of fermented tomato and feijoa juices.

SURVIVORSHIP NAVIGATION OUTCOME MEASURES: A report from the ACS Patient Navigation Working Group on Survivorship Navigation

PubMed Central

Pratt-Chapman, Mandi; Simon, Melissa A.; Patterson, Angela; Risendal, Betsy C.; Patierno, Steven

2013-01-01

Survivorship navigation is a relatively new concept in the field of patient navigation, but an important one. This paper highlights the essential functions of the survivorship navigator and defines core outcomes and measures for navigation in the survivorship period. Barriers to access to care experienced by patients during active cancer treatment can continue into the post-treatment period, affecting quality follow-up care for survivors. These barriers to care can be particularly acute for non-English speakers, immigrants, the uninsured, the underinsured and other vulnerable populations. The survivorship navigator can help reduce barriers and facilitate access to survivorship care and services through communication and information exchange for patients. Survivorship navigation may improve appropriate health care utilization through education and care coordination, potentially improving health outcomes and quality of life of survivors while reducing cost to the health care system. Survivorship navigators can also educate survivors on how to improve their overall wellness, thereby directly impacting the health of a growing population of cancer survivors. PMID:21780092

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

NASA Astrophysics Data System (ADS)

Fergus, Jeffrey W.

2014-06-01

One of the important applications of yttria-stabilized zirconia (YSZ) is as a thermal barrier coating for gas turbine engines. While YSZ performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite-derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability, and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatings are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.

Selective Matrix (Hyaluronan) Interaction with CD44 and RhoGTPase Signaling Promotes Keratinocyte Functions and Overcomes Age-related Epidermal Dysfunction

PubMed Central

Bourguignon, Lilly Y.W.; Wong, Gabriel; Xia, Weiliang; Man, Mao-Qiang; Holleran, Walter M.; Elias, Peter M.

2013-01-01

Background Mouse epidermal chronologic aging is closely associated with aberrant matrix (hyaluronan, HA) -size distribution/production and impaired keratinocyte proliferation/differentiation, leading to a marked thinning of the epidermis with functional consequence that causes a slower recovery of permeability barrier function. Objective The goal of this study is to demonstrate mechanism-based, corrective therapeutic strategies using topical applications of small HA (HAS) and/or large HA (HAL) [or a sequential small HA (HAS) and large HA(HAL) (HAs-»HAL) treatment] as well as RhoGTPase signaling perturbation agents to regulate HA/CD44-mediated signaling, thereby restoring normal epidermal function, and permeability barrier homeostasis in aged mouse skin. Methods A number of biochemical, cell biological/molecular, pharmacological and physiological approaches were used to investigate matrix HA-CD44-mediated RhoGTPase signaling in regulating epidermal functions and skin aging. Results In this study we demonstrated that topical application of small HA (HAS) promotes keratinocyte proliferation and increases skin thickness, while it fails to upregulate keratinocyte differentiation or permeability barrier repair in aged mouse skin. In contrast, large HA (HAL) induces only minimal changes in keratinocyte proliferation and skin thickness, but restores keratinocyte differentiation and improves permeability barrier function in aged epidermis. Since neither HAS nor HAL corrects these epidermal defects in aged CD44 knock-out mice, CD44 likely mediates HA-associated epidermal functions in aged mouse skin. Finally, blockade of Rho-kinase activity with Y27632 or protein kinase-Nγ activity with Ro31-8220 significantly decreased the HA (HAS or HAL)-mediated changes in epidermal function in aged mouse skin. Conclusion The results of our study show first that HA application of different sizes regulates epidermal proliferation, differentiation and barrier function in aged mouse skin. Second, manipulation of matrix (HA) interaction with CD44 and RhoGTPase signaling could provide further novel therapeutic approaches that could be targeted for the treatment of various aging-related skin disorders. PMID:23790635

IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats.

PubMed

Zhao, Tian-Yu; Su, Li-Ping; Ma, Chun-Ye; Zhai, Xiao-Han; Duan, Zhi-Jun; Zhu, Ying; Zhao, Gang; Li, Chun-Yan; Wang, Li-Xia; Yang, Dong

2015-07-08

Intestinal barrier dysfunction is not only the consequence of liver cirrhosis, but also an active participant in the development of liver cirrhosis. Previous studies showed that external administration of insulin-like growth factor 1 (IGF-1) improved intestinal barrier function in liver cirrhosis. However, the mechanism of IGF-1 on intestinal barrier in liver cirrhosis is not fully elucidated. The present study aims to investigate the mechanisms of IGF-1 improving intestinal barrier function via regulating tight junctions in intestines. We used carbon tetrachloride induced liver cirrhotic rats to investigate the effect of IGF-1 on intestinal claudin-1 and occludin expressions, serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, severity of liver fibrosis, portal pressures, enterocytic apoptosis and lipopolysaccharides (LPS) levels in portal vein. The changes of IGF-1 in serum during the development of rat liver cirrhosis were also evaluated. Additionally, we assessed the effect of IGF-1 on claudin-1 and occludin expressions, changes of transepithelial electrical resistance (TEER) and apoptosis in Caco-2 cells to confirm in vivo findings. Serum IGF-1 levels were decreased in the development of rat liver cirrhosis, and external administration of IGF-1 restored serum IGF-1 levels. External administration of IGF-1 reduced serum ALT and AST levels, severity of liver fibrosis, LPS levels in portal vein, enterocytic apoptosis and portal pressure in cirrhotic rats. External administration of IGF-1 increased the expressions of claudin-1 and occludin in enterocytes, and attenuated tight junction dysfunction in intestines of cirrhotic rats. LPS decreased TEER in Caco-2 cell monolayer. LPS also decreased claudin-1 and occludin expressions and increased apoptosis in Caco-2 cells. Furthermore, IGF-1 attenuated the effect of LPS on TEER, claudin-1 expression, occludin expression and apoptosis in Caco-2 cells. Tight junction dysfunction develops during the development of liver cirrhosis, and endotoxemia will develop subsequently. Correspondingly, increased endotoxin in portal system worsens tight junction dysfunction via decreasing intestinal occludin and claudin-1 expressions and increasing enterocytic apoptosis. Endotoxemia and intestinal barrier dysfunction form a vicious circle. External administration of IGF-1 breaks this vicious circle. Improvement of tight junctions might be one possible mechanism of the restoration of intestinal barrier function mediated by IGF-1.

Dimethyl fumarate reduces the risk of mycotoxins via improving intestinal barrier and microbiota

PubMed Central

Ma, Ning; Wu, Yi; Xie, Fei; Du, Kexin; Wang, Yuan; Shi, Linxin; Ji, Linbao; Liu, Tianyi; Ma, Xi

2017-01-01

The effects of dimethyl fumarate (DMF) on mycotoxins and animal growth performance are well documented. However, its mechanism of anti-mildew effects is still unknown. The current study investigated how DMF detoxified the mycotoxin and improved the growth performance using BALB/c mice model, especially its effects on intestinal barrier function and gut micro-ecology. Our study also compared with the ultraviolet radiation (UR) treatment, a traditional anti-mildew control (TC). The results indicated that the DMF treatment had a lower contents of mycotoxin, better growth performance and improved mucosal morphology (P < 0.05), accompanied with the decreased intestinal permeability and the tighter gut barrier. Moreover, the efficiency of DMF was better than TC (P < 0.05). 16S rRNA gene sequence analysis revealed that the richness and diversity of bacteria was increased in DMF treatment. The most abundant OTUs belonged to Firmicutes and Bacteroidetes, and their changes in DMF were more moderate than the TC group, suggesting a more stable micro-ecology and the positive impact of DMF on the biodiversity of intestine. Specifically, the increased abundance of bacteria producing short-chain fatty acids (SCFAs), such as Gemella, Roseburia, Bacillus and Bacteroides in DMF group and prebiotics such as Lactobacillus in TC group, suggested a more healthier microbial composition and distribution. These findings supported that DMF had significant effects on animal's growth performance and intestinal barrier function by modulating the pathway of nutrient absorption and increasing the diversity and balance of gut microbes, which also illuminate that DMF is more efficient than traditional anti-mildew method. PMID:28574825

Transplantation of in vitro cultured endothelial progenitor cells repairs the blood-brain barrier and improves cognitive function of APP/PS1 transgenic AD mice.

PubMed

Zhang, Shishuang; Zhi, Yongle; Li, Fei; Huang, Shan; Gao, Huabin; Han, Zhaoli; Ge, Xintong; Li, Dai; Chen, Fanglian; Kong, Xiaodong; Lei, Ping

2018-04-15

To date, the pathogenesis of Alzheimer's disease (AD) remains unclear. It is well-known that excessive deposition of Aβ in the brain is a crucial part of the pathogenesis of AD. In recent years, the AD neurovascular unit hypothesis has attracted much attention. Impairment of the blood-brain barrier (BBB) leads to abnormal amyloid-β (Aβ) transport, and chronic cerebral hypoperfusion causes Aβ deposition throughout the onset and progression of AD. Endothelial progenitor cells (EPCs) are the universal cells for repairing blood vessels. Our previous studies have shown that a reduced number of EPCs in the peripheral blood results in cerebral vascular repair disorder, cerebral hypoperfusion and neurodegeneration, which might be related to the cognitive dysfunction of AD patients. This study was designed to confirm whether EPCs transplantation could repair the blood-brain barrier, stimulate angiogenesis and reduce Aβ deposition in AD. The expression of ZO-1, Occludin and Claudin-5 was up-regulated in APP/PS1 transgenic mice after hippocampal transplantation of EPCs. Consistent with previous studies, EPC transplants also increased the microvessel density. We observed that Aβ senile plaque deposition was decreased and hippocampal cell apoptosis was reduced after EPCs transplantation. The Morris water maze test showed that spatial learning and memory functions were significantly improved in mice transplanted with EPCs. Consequently, EPCs could up-regulate the expression of tight junction proteins, repair BBB tight junction function, stimulate angiogenesis, promote Aβ clearance, and decrease neuronal loss, ultimately improve cognitive function. Taken together, these data demonstrate EPCs may play an important role in the therapeutic implications for vascular dysfunction in AD. Copyright © 2018 Elsevier B.V. All rights reserved.

Intestinal Alkaline Phosphatase Regulates Tight Junction Protein Levels

PubMed Central

Liu, Wei; Hu, Dong; Huo, Haizhong; Zhang, Weifeng; Adiliaghdam, Fatemeh; Morrison, Sarah; Ramirez, Juan M; Gul, Sarah S; Hamarneh, Sulaiman R; Hodin, Richard A

2017-01-01

BACKGROUND Intestinal alkaline phosphatase (IAP) plays a pivotal role in maintaining gut health and well-being. Oral supplementation with IAP in mice improves gut barrier function and prevents luminal proinflammatory factors from gaining access to the circulation. In this study, we sought to explore the relationship between IAP and tight junction protein (TJP) expression and function. STUDY DESIGN The effect of IAP deletion on TJP levels was studied in mouse embryonic fibroblasts (MEFs) generated from IAP-knockout and wild type mice. Regulation of TJPs by IAP was assayed in the human colon cancer Caco-2 and T84 cells by overexpressing the human IAP gene. Tight junction protein levels and localization were measured by using RT q-PCR and antibodies targeting the specific TJPs. Finally, the effect of IAP on inflammation-induced intestinal permeability was measured by in vitro trans-well epithelial electrical resistance (TEER). RESULTS Intestinal alkaline phosphatase gene deletion in MEFs resulted in significantly lower levels of ZO-1, ZO-2, and Occludin compared with levels in wild-type control cells; IAP over-expression in Caco-2 and T84 cells resulted in approximate 2-fold increases in the mRNA levels of ZO-1 and ZO-2. The IAP treatment ameliorated lipopolysaccharide-induced increased permeability in the Caco-2 trans-well system. Furthermore, IAP treatment preserved the localization of the ZO-1 and Occludin proteins during inflammation and was also associated with improved epithelial barrier function. CONCLUSIONS Intestinal alkaline phosphatase is a major regulator of gut mucosal permeability and appears to work at least partly through improving TJP levels and localization. These data provide a strong foundation to develop IAP as a novel therapy to maintain gut barrier function. PMID:27106638

Intestinal Alkaline Phosphatase Regulates Tight Junction Protein Levels.

PubMed

Liu, Wei; Hu, Dong; Huo, Haizhong; Zhang, Weifeng; Adiliaghdam, Fatemeh; Morrison, Sarah; Ramirez, Juan M; Gul, Sarah S; Hamarneh, Sulaiman R; Hodin, Richard A

2016-06-01

Intestinal alkaline phosphatase (IAP) plays a pivotal role in maintaining gut health and well-being. Oral supplementation with IAP in mice improves gut barrier function and prevents luminal proinflammatory factors from gaining access to the circulation. In this study, we sought to explore the relationship between IAP and tight junction protein (TJP) expression and function. The effect of IAP deletion on TJP levels was studied in mouse embryonic fibroblasts (MEFs) generated from IAP-knockout and wild type mice. Regulation of TJPs by IAP was assayed in the human colon cancer Caco-2 and T84 cells by overexpressing the human IAP gene. Tight junction protein levels and localization were measured by using RT q-PCR and antibodies targeting the specific TJPs. Finally, the effect of IAP on inflammation-induced intestinal permeability was measured by in vitro trans-well epithelial electrical resistance (TEER). Intestinal alkaline phosphatase gene deletion in MEFs resulted in significantly lower levels of ZO-1, ZO-2, and Occludin compared with levels in wild-type control cells; IAP overexpression in Caco-2 and T84 cells resulted in approximate 2-fold increases in the mRNA levels of ZO-1 and ZO-2. The IAP treatment ameliorated lipopolysaccharide-induced increased permeability in the Caco-2 trans-well system. Furthermore, IAP treatment preserved the localization of the ZO-1 and Occludin proteins during inflammation and was also associated with improved epithelial barrier function. Intestinal alkaline phosphatase is a major regulator of gut mucosal permeability and appears to work at least partly through improving TJP levels and localization. These data provide a strong foundation to develop IAP as a novel therapy to maintain gut barrier function. Copyright © 2016. Published by Elsevier Inc.

Performance of Density Functional Theory Procedures for the Calculation of Proton-Exchange Barriers: Unusual Behavior of M06-Type Functionals.

PubMed

Chan, Bun; Gilbert, Andrew T B; Gill, Peter M W; Radom, Leo

2014-09-09

We have examined the performance of a variety of density functional theory procedures for the calculation of complexation energies and proton-exchange barriers, with a focus on the Minnesota-class of functionals that are generally highly robust and generally show good accuracy. A curious observation is that M05-type and M06-type methods show an atypical decrease in calculated barriers with increasing proportion of Hartree-Fock exchange. To obtain a clearer picture of the performance of the underlying components of M05-type and M06-type functionals, we have investigated the combination of MPW-type and PBE-type exchange and B95-type and PBE-type correlation procedures. We find that, for the extensive E3 test set, the general performance of the various hybrid-DFT procedures improves in the following order: PBE1-B95 → PBE1-PBE → MPW1-PBE → PW6-B95. As M05-type and M06-type procedures are related to PBE1-B95, it would be of interest to formulate and examine the general performance of an alternative Minnesota DFT method related to PW6-B95.

Impedance analysis of GPCR-mediated changes in endothelial barrier function: overview, and fundamental considerations for stable and reproducible measurements

PubMed Central

Stolwijk, Judith A.; Matrougui, Khalid; Renken, Christian W.; Trebak, Mohamed

2014-01-01

The past 20 years have seen significant growth in using impedance-based assays to understand the molecular underpinning of endothelial and epithelial barrier function in response to physiological agonists, pharmacological and toxicological compounds. Most studies on barrier function use G protein coupled receptor (GPCR) agonists which couple to fast and transient changes in barrier properties. The power of impedance based techniques such as Electric Cell-Substrate Impedance Sensing (ECIS) reside in its ability to detect minute changes in cell layer integrity label-free and in real-time ranging from seconds to days. We provide a comprehensive overview of the biophysical principles, applications and recent developments in impedance-based methodologies. Despite extensive application of impedance analysis in endothelial barrier research little attention has been paid to data analysis and critical experimental variables, which are both essential for signal stability and reproducibility. We describe the rationale behind common ECIS data presentation and interpretation and illustrate practical guidelines to improve signal intensity by adapting technical parameters such as electrode layout, monitoring frequency or parameter (resistance versus impedance magnitude). Moreover, we discuss the impact of experimental parameters, including cell source, liquid handling and agonist preparation on signal intensity and kinetics. Our discussions are supported by experimental data obtained from human microvascular endothelial cells challenged with three GPCR agonists, thrombin, histamine and Sphingosine-1-Phosphate. PMID:25537398

Impedance analysis of GPCR-mediated changes in endothelial barrier function: overview and fundamental considerations for stable and reproducible measurements.

PubMed

Stolwijk, Judith A; Matrougui, Khalid; Renken, Christian W; Trebak, Mohamed

2015-10-01

The past 20 years has seen significant growth in using impedance-based assays to understand the molecular underpinning of endothelial and epithelial barrier function in response to physiological agonists and pharmacological and toxicological compounds. Most studies on barrier function use G protein-coupled receptor (GPCR) agonists which couple to fast and transient changes in barrier properties. The power of impedance-based techniques such as electric cell-substrate impedance sensing (ECIS) resides in its ability to detect minute changes in cell layer integrity label-free and in real-time ranging from seconds to days. We provide a comprehensive overview of the biophysical principles, applications, and recent developments in impedance-based methodologies. Despite extensive application of impedance analysis in endothelial barrier research, little attention has been paid to data analysis and critical experimental variables, which are both essential for signal stability and reproducibility. We describe the rationale behind common ECIS data presentation and interpretation and illustrate practical guidelines to improve signal intensity by adapting technical parameters such as electrode layout, monitoring frequency, or parameter (resistance versus impedance magnitude). Moreover, we discuss the impact of experimental parameters, including cell source, liquid handling, and agonist preparation on signal intensity and kinetics. Our discussions are supported by experimental data obtained from human microvascular endothelial cells challenged with three GPCR agonists, thrombin, histamine, and sphingosine-1-phosphate.

Teamwork and team decision-making at multidisciplinary cancer conferences: barriers, facilitators, and opportunities for improvement.

PubMed

Lamb, Benjamin W; Sevdalis, Nick; Arora, Sonal; Pinto, Anna; Vincent, Charles; Green, James S A

2011-09-01

Anecdotally, multidisciplinary cancer conferences (MCCs) do not always function optimally. MCC members' experiences with and attitudes toward MCCs are explored, and barriers to and facilitators of effective team-working are identified. A total of 19 semistructured interviews were conducted with surgeons, oncologists, nurses, and administrators. Interviews explored participants' opinions on MCC attendance, information presentation, case discussion, leadership, team decision-making, and possible improvements to MCC meetings. Nonattendance was associated with not having protected time to attend the MCC. Contributions to MCC discussions were unequal among the participants, and patient-centered information was ignored. Good leadership was necessary to foster inclusive case discussion. Members were positive about MCCs, but protected time, improved case selection, and working in a more structured way were possible improvements. Results are consistent with previous research: Members of the MCC are positive about the benefits of MCCs, although improving the way MCCs work is a goal.

[Barriers and challenges of the functional healthcare risk management units in hospitals of Madrid health service].

PubMed

Pardo-Hernández, A; Navarro-Royo, C; Arguedas-Sanz, R; Albeniz-Lizarraga, C; Morón-Merchante, J

2014-01-01

To identify the barriers and challenges for the effective development of risk management units in hospitals of the Madrid Health Service. Descriptive cross-sectional study aimed at the management teams and members of the functional units of 31 hospitals in the Madrid Health Service. A self-administered questionnaire requesting answers in free text was used, identifying up to five barriers and challenges, and their prioritization by awarding from 1-5 points according to their importance. A discourse analysis was then conducted, grouping common themes and sorting them according to their score. The overall response rate was 94%. The most frequently identified barriers were lack of time (21%), inadequate safety culture (13%), lack of publication of their activities (10%), and lack of training (10%). The most important challenge was developing the training (18%), followed by improving the culture (17%), communication of safety activities (11%), and achieve leadership from the managers of the services (11%). According to the study conditions, the main identified barrier identified was the lack of available time, and the principal challenge found was promoting a proactive learning culture. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.

Observation of quantum oscillation of work function in ultrathin-metal/semiconductor junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takhar, Kuldeep; Meer, Mudassar; Khachariya, Dolar

2015-09-15

Quantization in energy level due to confinement is generally observed for semiconductors. This property is used for various quantum devices, and it helps to improve the characteristics of conventional devices. Here, the authors have demonstrated the quantum size effects in ultrathin metal (Ni) layers sandwiched between two large band-gap materials. The metal work function is found to oscillate as a function of its thickness. The thermionic emission current bears the signature of the oscillating work function, which has a linear relationship with barrier heights. This methodology allows direct observation of quantum oscillations in metals at room temperature using a Schottkymore » diode and electrical measurements using source-measure-units. The observed phenomena can provide additional mechanism to tune the barrier height of metal/semiconductor junctions, which are used for various electronic devices.« less

Low dose Naltrexone for induction of remission in inflammatory bowel disease patients.

PubMed

Lie, Mitchell R K L; van der Giessen, Janine; Fuhler, Gwenny M; de Lima, Alison; Peppelenbosch, Maikel P; van der Ent, Cokkie; van der Woude, C Janneke

2018-03-09

Around 30% of patients with inflammatory bowel disease (IBD) are refractory to current IBD drugs or relapse over time. Novel treatments are called for, and low dose Naltrexone (LDN) may provide a safe, easily accessible alternative treatment option for these patients. We investigated the potential of LDN to induce clinical response in therapy refractory IBD patients, and investigated its direct effects on epithelial barrier function. Patients not in remission and not responding to conventional therapy were offered to initiate LDN as a concomitant treatment. In total 47 IBD patients prescribed LDN were followed prospectively for 12 weeks. Where available, endoscopic remission data, serum and biopsies were collected. Further the effect of Naltrexone on wound healing (scratch assay), cytokine production and endoplasmic reticulum (ER) stress (GRP78 and CHOP western blot analysis, immunohistochemistry) were investigated in HCT116 and CACO2 intestinal epithelial cells, human IBD intestinal organoids and patient samples. Low dose Naltrexone induced clinical improvement in 74.5%, and remission in 25.5% of patients. Naltrexone improved wound healing and reduced ER stress induced by Tunicamycin, lipopolysaccharide or bacteria in epithelial barriers. Inflamed mucosa from IBD patients showed high ER stress levels, which was reduced in patients treated with LDN. Cytokine levels in neither epithelial cells nor serum from IBD patients were affected. Naltrexone directly improves epithelial barrier function by improving wound healing and reducing mucosal ER stress levels. Low dose Naltrexone treatment is effective and safe, and could be considered for the treatment of therapy refractory IBD patients.

Inhibition of cyclooxygenase-2 alleviates liver cirrhosis via improvement of the dysfunctional gut-liver axis in rats.

PubMed

Gao, Jin-Hang; Wen, Shi-Lei; Tong, Huan; Wang, Chun-Hui; Yang, Wen-Juan; Tang, Shi-Hang; Yan, Zhao-Ping; Tai, Yang; Ye, Cheng; Liu, Rui; Huang, Zhi-Yin; Tang, Ying-Mei; Yang, Jin-Hui; Tang, Cheng-Wei

2016-06-01

Inflammatory transport through the gut-liver axis may facilitate liver cirrhosis. Cyclooxygenase-2 (COX-2) has been considered as one of the important molecules that regulates intestinal epithelial barrier function. This study was aimed to test the hypothesis that inhibition of COX-2 by celecoxib might alleviate liver cirrhosis via reduction of intestinal inflammatory transport in thiacetamide (TAA) rat model. COX-2/prostaglandin E2 (PGE2)/EP-2/p-ERK integrated signal pathways regulated the expressions of intestinal zonula occludens-1 (ZO-1) and E-cadherin, which maintain the function of intestinal epithelial barrier. Celecoxib not only decreased the intestinal permeability to a 4-kDa FITC-dextran but also significantly increased expressions of ZO-1 and E-cadherin. When celecoxib greatly decreased intestinal levels of LPS, TNF-α, and IL-6, it significantly enhanced T cell subsets reduced by TAA. As a result, liver fibrosis induced by TAA was significantly alleviated in the celecoxib group. These data indicated that celecoxib improved the integrity of intestinal epithelial barrier, blocked inflammatory transport through the dysfunctional gut-liver axis, and ameliorated the progress of liver cirrhosis. Copyright © 2016 the American Physiological Society.

FABP4 induces asthmatic airway epithelial barrier dysfunction via ROS-activated FoxM1.

PubMed

Wu, Gaohui; Yang, Liteng; Xu, Yi; Jiang, Xiaohong; Jiang, Xiaomin; Huang, Lisha; Mao, Ling; Cai, Shaoxi

2018-01-01

Functional abnormal airway epithelial cells, along with activated inflammatory cells, resulting in chronic airway inflammation, are considered as the characteristic of asthma. Fatty Acid Binding Protein 4 (FABP4) takes part in glucose and lipid homeostasis, and also have an important role in allergic airway inflammation. However, whether FABP4 influence barrier function of airway epithelial cells is unknown. In vivo, a HDM-induced murine model of asthma was obtained to assessed airway inflammation and protein expression of E-cadherin and Forkhead Box M1 (FoxM1). In vitro, 16-HBE was cultured and was treated with hrFABP4, siFABP4, FABPF4 inhibitor BMS, or FoxM1 inhibitor RCM-1. IL-4, IL-5, and IL-13 level was determined by ELISA. Transepithelial electrical resistance (TER), paracellular permeability and E-cadherin-special immunofluorescence were measured to value airway epithelial barrier function. Intracellular ROS production was determined by DCF-DA fluorescence. FABP4 inhibitor BMS alleviate airway inflammation and destruction of E-cad in allergic mouse. Treatment with HDM or hrFABP4 aggravated inflammatory response, damaged airway epithelial barrier, which could be inhibited by siFABP4 and BMS. Treatment with HDM or hrFABP4 also enhanced levels of FoxM1, and Inhibited FoxM1 suppressed HDM- and hrFABP4-induced inflammation and airway epithelial barrier dysfunction. In addition, H 2 O 2 promoted FoxM1 expression, HDM and hrFABP4 induced-FoxM1 could be inhibited by NAC, leading to decreased inflammation and improved airway epithelial barrier. Upregulated ROS induced by FABP4 was of significance in activating FoxM1 leading to airway inflammation and epithelial barrier dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Extravasation of polymeric nanomedicines across tumor vasculature.

PubMed

Danquah, Michael K; Zhang, Xin A; Mahato, Ram I

2011-07-18

Tumor microvasculature is fraught with numerous physiological barriers which hinder the efficacy of anticancer agents. These barriers include chaotic blood supply, poor tumor vasculature permeability, limited transport across the interstitium due to high interstitial pressure and absence of lymphatic network. Abnormal microvasculature also leads to hypoxia and acidosis which limits effectiveness of chemotherapy. These barriers restrict drug or drug carrier extravasation which hampers tumor regression. Targeting key features of the tumor microenvironment such as tumor microvessels, interstitial hypertension and tumor pH is a promising approach to improving the efficacy of anticancer drugs. This review highlights the current knowledge on the distinct tumor microenvironment generated barriers which limit extravasation of drugs and focuses on modalities for overcoming these barriers using multi-functional polymeric carriers. Special attention is given to utilizing polymeric nanomedicines to facilitate extravasation of anticancer drugs for future cancer therapy. Copyright © 2010 Elsevier B.V. All rights reserved.

Barrier function and microbiotic dysbiosis in atopic dermatitis

PubMed Central

Seite, Sophie; Bieber, Thomas

2015-01-01

Atopic dermatitis (AD) or atopic eczema is the common inflammatory skin disorder, the prevalence of which has considerably increased during the last 30 years. It affects 15%–30% of children and 2%–10% of adults. AD characteristically alternates between periods of exacerbation or flares and periods of remission, which may be therapeutically induced or spontaneous. Current knowledge about AD includes abnormalities of the skin barrier (physical and chemical), the immune barrier, and more recently, the microbial barrier or microbiota. There is growing evidence for a tight relationship between them. To obtain satisfactory control of this condition, the clinical strategy to manage AD involves prescribing both anti-inflammatory medications and dermocosmetic products. The role of the physician is therefore to advise the patient with regard to hygiene measures aimed to help to improve these three barriers or to prevent any further deterioration. PMID:26396539

Resonant tunneling diode based on band gap engineered graphene antidot structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palla, Penchalaiah, E-mail: penchalaiah.palla@vit.ac.in; Ethiraj, Anita S.; Raina, J. P.

The present work demonstrates the operation and performance of double barrier Graphene Antidot Resonant Tunnel Diode (DBGA-RTD). Non-Equilibrium Green’s Function (NEGF) frame work with tight-binding Hamiltonian and 2-D Poisson equations were solved self-consistently for device study. The interesting feature in this device is that it is an all graphene RTD with band gap engineered graphene antidot tunnel barriers. Another interesting new finding is that it shows negative differential resistance (NDR), which involves the resonant tunneling in the graphene quantum well through both the electron and hole bound states. The Graphene Antidot Lattice (GAL) barriers in this device efficiently improved themore » Peak to Valley Ratio to approximately 20 even at room temperature. A new fitting model is developed for the number of antidots and their corresponding effective barrier width, which will help in determining effective barrier width of any size of actual antidot geometry.« less

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

DOE PAGES

Fergus, Jeffrey W.

2014-04-12

One of the important applications of yttria stabilized zirconia is as a thermal barrier coating for gas turbine engines. While yttria stabilized zirconia performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatingsmore » are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.« less

Claudins, dietary milk proteins, and intestinal barrier regulation.

PubMed

Kotler, Belinda M; Kerstetter, Jane E; Insogna, Karl L

2013-01-01

The family of claudin proteins plays an important role in regulating the intestinal barrier by modulating the permeability of tight junctions. The impact of dietary protein on claudin biology has not been studied extensively. Whey proteins have been reported to improve intestinal barrier function, but their mechanism of action is not clear. Recent studies, however, have demonstrated increased intestinal claudin expression in response to milk protein components. Reviewed here are new findings suggesting that whey-protein-derived transforming growth factor β transcriptionally upregulates claudin-4 expression via a Smad-4-dependent pathway. These and other data, including limited clinical studies, are summarized below and, in the aggregate, suggest a therapeutic role for whey protein in diseases of intestinal barrier dysfunction, perhaps, in part, by regulating claudin expression. © 2013 International Life Sciences Institute.

Thiolated silicone oils as adhesive skin protectants for improved barrier function.

PubMed

Partenhauser, A; Zupančič, O; Rohrer, J; Bonengel, S; Bernkop-Schnürch, A

2016-06-01

The purpose of this study was the evaluation of thiolated silicone oil as novel skin protectant exhibiting prolonged residence time, enhanced barrier function and reinforced occlusivity. Two silicone conjugates were synthesized with mercaptopropionic acid (MPA) and thioglycolic acid (TGA) as thiol ligands. Adhesion, protection against artificial urine and water vapour permeability with both a Payne cup set-up and transepidermal water loss (TEWL) measurements on porcine skin were assessed. Silicone thiomers showed pronounced substantivity on skin with 22.1 ± 6.3% and 39.2 ± 6.7% remaining silicone after 8 h for silicone-TGA and silicone-MPA, respectively, whereas unmodified silicone oil and dimethicone were no longer detectable. In particular, silicone-MPA provided a protective shield against artificial urine penetration with less than 25% leakage within 6 h. An up to 2.5-fold improved water vapour impermeability for silicone-MPA in comparison with unmodified control was discovered with the Payne cup model. In addition, for silicone-MPA a reduced TEWL by two-thirds corresponding to non-thiolated control was determined for up to 8 h. Thiolation of silicone oil leads to enhanced skin adhesiveness and barrier function, which is a major advantage compared to commonly used silicones and might thus be a promising treatment modality for various topical applications. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Built-in potential shift and Schottky-barrier narrowing in organic solar cells with UV-sensitive electron transport layers.

PubMed

Li, Cheng; Credgington, Dan; Ko, Doo-Hyun; Rong, Zhuxia; Wang, Jianpu; Greenham, Neil C

2014-06-28

The performance of organic solar cells incorporating solution-processed titanium suboxide (TiOx) as electron-collecting layers can be improved by UV illumination. We study the mechanism of this improvement using electrical measurements and electroabsorption spectroscopy. We propose a model in which UV illumination modifies the effective work function of the oxide layer through a significant increase in its free electron density. This leads to a dramatic improvement in device power conversion efficiency through several mechanisms - increasing the built-in potential by 0.3 V, increasing the conductivity of the TiOx layer and narrowing the interfacial Schottky barrier between the suboxide and the underlying transparent electrode. This work highlights the importance of considering Fermi-level equilibration when designing multi-layer transparent electrodes.

Towards Improvements for Penetrating the Blood–Brain Barrier—Recent Progress from a Material and Pharmaceutical Perspective

PubMed Central

He, Quanguo; Liu, Jun; Liang, Jing; Liu, Xiaopeng; Li, Wen; Liu, Zhi; Ding, Ziyu; Tuo, Du

2018-01-01

The blood–brain barrier (BBB) is a critical biological structure that prevents damage to the brain and maintains its bathing microenvironment. However, this barrier is also the obstacle to deliver beneficial drugs to treat CNS (central nervous system) diseases. Many efforts have been made for improvement of delivering drugs across the BBB in recent years to treat CNS diseases. In this review, the anatomical and functional structure of the BBB is comprehensively discussed. The mechanisms of BBB penetration are summarized, and the methods and effects on increasing BBB permeability are investigated in detail. It also elaborates on the physical, chemical, biological and nanocarrier aspects to improve drug delivery penetration to the brain and introduces some specific drug delivery effects on BBB permeability. PMID:29570659

Barrier Function of the Repaired Skin Is Disrupted Following Arrest of Dicer in Keratinocytes

PubMed Central

Ghatak, Subhadip; Chan, Yuk Cheung; Khanna, Savita; Banerjee, Jaideep; Weist, Jessica; Roy, Sashwati; Sen, Chandan K

2015-01-01

Tissue injury transiently silences miRNA-dependent posttranscriptional gene silencing in its effort to unleash adult tissue repair. Once the wound is closed, miRNA biogenesis is induced averting neoplasia. In this work, we report that Dicer plays an important role in reestablishing the barrier function of the skin post-wounding via a miRNA-dependent mechanism. MicroRNA expression profiling of skin and wound-edge tissue revealed global upregulation of miRNAs following wound closure at day 14 post-wounding with significant induction of Dicer expression. Barrier function of the skin, as measured by trans-epidermal water loss, was compromised in keratinocyte-specific conditional (K14/Lox-Cre) Dicer-ablated mice because of malformed cornified epithelium lacking loricrin expression. Studies on human keratinocytes recognized that loricrin expression was inversely related to the expression of the cyclin-dependent kinase inhibitor p21Waf1/Cip1. Compared to healthy epidermis, wound-edge keratinocytes from Dicer-ablated skin epidermis revealed elevated p21Waf1/Cip1 expression. Adenoviral and pharmacological suppression of p21Waf1/Cip1 in keratinocyte-specific conditional Dicer-ablated mice improved wound healing indicating a role of Dicer in the suppression of p21Waf1/Cip1. This work upholds p21Waf1/Cip1 as a druggable target to restore barrier function of skin suffering from loss of Dicer function as would be expected in diabetes and other forms of oxidant insult. PMID:25896246

Introduction for the special issue on recent advances in drug delivery across tissue barriers.

PubMed

Mrsny, Randall J; Brayden, David J

2016-01-01

This special issue of Tissue Barriers contains a series of reviews with the common theme of how biological barriers established at epithelial tissues limit the uptake of macromolecular therapeutics. By improving our functional understanding of these barriers, the majority of the authors have highlighted potential strategies that might be applied to the non-invasive delivery of biopharmaceuticals that would otherwise require an injection format for administration. Half of the articles focus on the potential of particular technologies to assist oral delivery of peptides, proteins and other macromolecules. These include use of prodrug chemistry to improve molecule stability and permeability, and the related potential for oral delivery of poorly permeable agents by cell-penetrating peptides and dendrimers. Safety aspects of intestinal permeation enhancers are discussed, along with the more recent foray into drug-device combinations as represented by intestinal microneedles and externally-applied ultrasound. Other articles highlight the crossover between food research and oral delivery based on nanoparticle technology, while the final one provides a fascinating interpretation of the physiological problems associated with subcutaneous insulin delivery and how inefficient it is at targeting the liver.

Effects of cognate, non-cognate and synthetic CXCR4 and ACKR3 ligands on human lung endothelial cell barrier function.

PubMed

Cheng, You-Hong; Eby, Jonathan M; LaPorte, Heather M; Volkman, Brian F; Majetschak, Matthias

2017-01-01

Recent evidence suggests that chemokine CXCL12, the cognate agonist of chemokine receptors CXCR4 and ACKR3, reduces thrombin-mediated impairment of endothelial barrier function. A detailed characterization of the effects of CXCL12 on thrombin-mediated human lung endothelial hyperpermeability is lacking and structure-function correlations are not available. Furthermore, effects of other CXCR4/ACKR3 ligands on lung endothelial barrier function are unknown. Thus, we tested the effects of a panel of CXCR4/ACKR3 ligands (CXCL12, CXCL11, ubiquitin, AMD3100, TC14012) and compared the CXCR4/ACKR3 activities of CXCL12 variants (CXCL12α/β, CXCL12(3-68), CXCL121, CXCL122, CXCL12-S-S4V, CXCL12-R47E, CXCL12-K27A/R41A/R47A) with their effects on human lung endothelial barrier function in permeability assays. CXCL12α enhanced human primary pulmonary artery endothelial cell (hPPAEC) barrier function, whereas CXCL11, ubiquitin, AMD3100 and TC14012 were ineffective. Pre-treatment of hPPAEC with CXCL12α and ubiquitin reduced thrombin-mediated hyperpermeability. CXCL12α-treatment of hPPAEC after thrombin exposure reduced barrier function impairment by 70% (EC50 0.05-0.5nM), which could be antagonized with AMD3100; ubiquitin (0.03-3μM) was ineffective. In a human lung microvascular endothelial cell line (HULEC5a), CXCL12α and ubiquitin post-treatment attenuated thrombin-induced hyperpermeability to a similar degree. CXCL12(3-68) was inefficient to activate CXCR4 in Presto-Tango β-arrestin2 recruitment assays; CXCL12-S-S4V, CXCL12-R47E and CXCL12-K27A/R41A/R47A showed significantly reduced potencies to activate CXCR4. While the potencies of all proteins in ACKR3 Presto-Tango assays were comparable, the efficacy of CXCL12(3-68) to activate ACKR3 was significantly reduced. The potencies to attenuate thrombin-mediated hPPAEC barrier function impairment were: CXCL12α/β, CXCL121, CXCL12-K27A/R41A/R47A > CXCL12-S-S4V, CXCL12-R47E > CXCL122 > CXCL12(3-68). Our findings indicate that CXCR4 activation attenuates thrombin-induced lung endothelial barrier function impairment and suggest that protective effects of CXCL12 are dictated by its CXCR4 agonist activity and interactions of distinct protein moieties with heparan sulfate on the endothelial surface. These data may facilitate development of compounds with improved pharmacological properties to attenuate thrombin-induced vascular leakage in the pulmonary circulation.

Noncontacting Laser Inspection System for Dimensional Profiling of Space Application Thermal Barriers

NASA Technical Reports Server (NTRS)

Taylor, Shawn C.

2011-01-01

A noncontacting, two-dimensional (2-D) laser inspection system has been designed and implemented to dimensionally profile thermal barriers being developed for space vehicle applications. In a vehicle as-installed state, thermal barriers are commonly compressed between load sensitive thermal protection system (TPS) panels to prevent hot gas ingestion through the panel interface during flight. Loads required to compress the thermal barriers are functions of their construction, as well as their dimensional characteristics relative to the gaps in which they are installed. Excessive loads during a mission could damage surrounding TPS panels and have catastrophic consequences. As such, accurate dimensional profiling of thermal barriers prior to use is important. Due to the compliant nature of the thermal barriers, traditional contact measurement techniques (e.g., calipers and micrometers) are subjective and introduce significant error and variability into collected dimensional data. Implementation of a laser inspection system significantly enhanced the method by which thermal barriers are dimensionally profiled, and improved the accuracy and repeatability of collected data. A statistical design of experiments study comparing laser inspection and manual caliper measurement techniques verified these findings.

Identifying barriers to recovery from work related upper extremity disorders: use of a collaborative problem solving technique.

PubMed

Shaw, William S; Feuerstein, Michael; Miller, Virginia I; Wood, Patricia M

2003-08-01

Improving health and work outcomes for individuals with work related upper extremity disorders (WRUEDs) may require a broad assessment of potential return to work barriers by engaging workers in collaborative problem solving. In this study, half of all nurse case managers from a large workers' compensation system were randomly selected and invited to participate in a randomized, controlled trial of an integrated case management (ICM) approach for WRUEDs. The focus of ICM was problem solving skills training and workplace accommodation. Volunteer nurses attended a 2 day ICM training workshop including instruction in a 6 step process to engage clients in problem solving to overcome barriers to recovery. A chart review of WRUED case management reports (n = 70) during the following 2 years was conducted to extract case managers' reports of barriers to recovery and return to work. Case managers documented from 0 to 21 barriers per case (M = 6.24, SD = 4.02) within 5 domains: signs and symptoms (36%), work environment (27%), medical care (13%), functional limitations (12%), and coping (12%). Compared with case managers who did not receive the training (n = 67), workshop participants identified more barriers related to signs and symptoms, work environment, functional limitations, and coping (p < .05), but not to medical care. Problem solving skills training may help focus case management services on the most salient recovery factors affecting return to work.

A Lactobacillus mutant capable of accumulating long-chain polyphosphates that enhance intestinal barrier function.

PubMed

Saiki, Asako; Ishida, Yasuaki; Segawa, Shuichi; Hirota, Ryuichi; Nakamura, Takeshi; Kuroda, Akio

2016-05-01

Inorganic polyphosphate (polyP) was previously identified as a probiotic-derived substance that enhances intestinal barrier function. PolyP-accumulating bacteria are expected to have beneficial effects on the human gastrointestinal tract. In this study, we selected Lactobacillus paracasei JCM 1163 as a strain with the potential to accumulate polyP, because among the probiotic bacteria stored in our laboratory, it had the largest amount of polyP. The chain length of polyP accumulated in L. paracasei JCM 1163 was approximately 700 phosphate (Pi) residues. L. paracasei JCM 1163 accumulated polyP when Pi was added to Pi-starved cells. We further improved the ability of L. paracasei JCM 1163 to accumulate polyP by nitrosoguanidine mutagenesis. The mutant accumulated polyP at a level of 1500 nmol/mg protein-approximately 190 times that of the wild-type strain. PolyP extracted from the L. paracasei JCM 1163 significantly suppressed the oxidant-induced intestinal permeability in mouse small intestine. In conclusion, we have succeeded in breeding the polyP-accumulating Lactobacillus mutant that is expected to enhance intestinal barrier function.

Experimental investigation of defect-assisted and intrinsic water vapor permeation through ultrabarrier films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hyungchul; Singh, Ankit Kumar; Wang, Cheng-Yin

In the development of ultrabarrier films for packaging electronics, the effective water vapor transmission rate is a combination of permeation through pinhole defects and the intrinsic permeation through the actual barrier film. While it is possible to measure the effective permeation rate through barriers, it is important to develop a better understanding of the contribution from defects to the overall effective barrier performance. Here, we demonstrate a method to investigate independently defect-assisted permeation and intrinsic permeation rates by observing the degradation of a calcium layer encapsulated with a hybrid barrier film, that is, prepared using atomic layer deposition (ALD) andmore » plasma enhanced deposition (PECVD). The results are rationalized using an analytical diffusion model to calculate the permeation rate as a function of spatial position within the barrier. It was observed that a barrier film consisting of a PECVD SiN{sub x} layer combined with an ALD Al{sub 2}O{sub 3}/HfO{sub x} nanolaminate resulted in a defect-assisted water vapor transmission rate (WVTR) of 4.84 × 10{sup −5} g/m{sup 2} day and intrinsic WVTR of 1.41 × 10{sup −4} g/m{sup 2} day at 50 °C/85% RH. Due to the low defect density of the tested barrier film, the defect-assisted WVTR was found to be three times lower than the intrinsic WVTR, and an effective (or total) WVTR value was 1.89 × 10{sup −4} g/m{sup 2} day. Thus, improvements of the barrier performance should focus on reducing the number of defects while also improving the intrinsic barrier performance of the hybrid layer.« less

Physics of Gate Modulated Resonant Tunneling (RT)-FETs: Multi-barrier MOSFET for steep slope and high on-current

NASA Astrophysics Data System (ADS)

Afzalian, Aryan; Colinge, Jean-Pierre; Flandre, Denis

2011-05-01

A new concept of nanoscale MOSFET, the Gate Modulated Resonant Tunneling Transistor (RT-FET), is presented and modeled using 3D Non-Equilibrium Green's Function simulations enlightening the main physical mechanisms. Owing to the additional tunnel barriers and the related longitudinal confinement present in the device, the density of state is reduced in its off-state, while remaining comparable in its on-state, to that of a MOS transistor without barriers. The RT-FET thus features both a lower RT-limited off-current and a faster increase of the current with V G, i.e. an improved slope characteristic, and hence an improved Ion/ Ioff ratio. Such improvement of the slope can happen in subthreshold regime, and therefore lead to subthreshold slope below the kT/q limit. In addition, faster increase of current and improved slope occur above threshold and lead to high thermionic on-current and significant Ion/ Ioff ratio improvement, even with threshold voltage below 0.2 V and supply voltage V dd of a few hundreds of mV as critically needed for future technology nodes. Finally RT-FETs are intrinsically immune to source-drain tunneling and are therefore promising candidate for extending the roadmap below 10 nm.

Depicting individual responses to physical therapist led chronic pain self-management support with pain science education and exercise in primary health care: multiple case studies.

PubMed

Miller, Jordan; MacDermid, Joy C; Richardson, Julie; Walton, David M; Gross, Anita

2017-01-01

Previous evidence suggests self-management programs for people with chronic pain improve knowledge and self-efficacy, but result in small to negligible changes in function. The purpose of this multiple case studies design was to describe the unique responses of six participants to a new self-management program aimed at improving function, to detail each component of the program, and to explore potential explanations for the varied trajectories of each of the participants. Six participants who had been experiencing chronic pain for at least 5 years were included. All participants were enrolled 6 weeks of ChrOnic pain self-ManageMent support with pain science EducatioN and exercise (COMMENCE). Participants completed an assessment at baseline, 7 weeks (1-week follow-up), and 18 weeks (12-week follow-up). Each participant had a unique initial presentation and goals. Assessments included: function as measured by the Short Musculoskeletal Function Assessment - Dysfunction Index, how much participants are bothered by functional difficulties, pain intensity, fatigue, pain interference, cognitive and psychological factors associated with pain and disability, pain neurophysiology, self-efficacy, satisfaction, and perceived change. The self-management program was 6-weeks in length, consisting of one individual visit and one group visit per week. The program incorporated three novel elements not commonly included in self-management programs: pain neurophysiology education, individualized exercises determined by the participants' goals, and additional cognitive behavioural approaches. Participants were all satisfied with self-management support received. Change in function was variable ranging from 59% improvement to 17% decline. Two potential explanations for variances in response, attendance and social context, are discussed. Several challenges were identified by participants as barriers to attendance. A primary care self-management intervention including pain education and individualized exercise has potential to improve function for some people with chronic pain, although strategies to improve adherence and reduce barriers to participation may be needed to optimize the impact.

Effects of moisturizing skincare on skin barrier function and the prevention of skin problems in 3-month-old infants: A randomized controlled trial.

PubMed

Yonezawa, Kaori; Haruna, Megumi; Matsuzaki, Masayo; Shiraishi, Mie; Kojima, Reiji

2018-01-01

An effective newborn skincare protocol has not been established. We aimed to evaluate the effects of moisturizing skincare, including using lotion and reducing routine bathing. Our hypothesis was that moisturizing skincare would improve skin barrier function. This randomized controlled trial included 227 healthy Asian newborns between 1 week and 3 months old. We compared moisturizing skincare (bathing every 2 days and using lotion daily; intervention, n = 113) to daily bathing without lotion (control, n = 114). We assessed the skin barrier function (transepidermal water loss [TEWL], stratum corneum hydration [SCH], skin pH and sebum secretion) as a primary outcome at 3 months old. We also assessed the incidence of skin problems according to parents' diary reports. Compared with the control, the intervention group had a lower face TEWL (mean ± standard deviation, 14.69 ± 7.38 vs 17.08 ± 8.26 g/m 2 per h, P = 0.033), higher face SCH (60.38 ± 13.66 vs 53.52 ± 14.55, P = 0.001) and higher body SCH (58.89 ± 12.96 vs 53.02 ± 10.08, P < 0.001). Compared with the control, newborns in the intervention group had significantly lower rates of diaper dermatitis between birth and 1 month old (6.3% vs 15.9%, P = 0.022), and tended to have lower rates of body skin problems between 1 and 3 months (42.1% vs 55.2%, P = 0.064). Moisturizing skincare was effective for improving skin barrier function and preventing newborns' diaper dermatitis. The results of our study may help parents make informed decisions about newborn skincare. © 2017 Japanese Dermatological Association.

Effects of glutamine alone or in combination with zinc and vitamin A on growth, intestinal barrier function, stress and satiety-related hormones in Brazilian shantytown children.

PubMed

Lima, Aldo A M; Anstead, Gregory M; Zhang, Qiong; Figueiredo, Ítalo L; Soares, Alberto M; Mota, Rosa M S; Lima, Noélia L; Guerrant, Richard L; Oriá, Reinaldo B

2014-01-01

To determine the impact of supplemental zinc, vitamin A, and glutamine alone or in combination on growth, intestinal barrier function, stress and satiety-related hormones among Brazilian shantytown children with low median height-for-age z-scores. A randomized, double-blind, placebo-controlled trial was conducted in children aged two months to nine years from the urban shanty compound community of Fortaleza, Brazil. Demographic and anthropometric information was assessed. The random treatment groups available for testing (a total of 120 children) were as follows: (1) glutamine alone, n = 38; (2) glutamine plus vitamin A plus zinc, n = 37; and a placebo (zinc plus vitamin A vehicle) plus glycine (isonitrogenous to glutamine) control treatment, n = 38. Leptin, adiponectin, insulin-like growth factor (IGF-1), and plasma levels of cortisol were measured with immune-enzymatic assays; urinary lactulose/mannitol and serum amino acids were measured with high-performance liquid chromatography. ClinicalTrials.gov: NCT00133406. Glutamine treatment significantly improved weight-for-height z-scores compared to the placebo-glycine control treatment. Either glutamine alone or all nutrients combined prevented disruption of the intestinal barrier function, as measured by the percentage of lactulose urinary excretion and the lactulose:mannitol absorption ratio. Plasma leptin was negatively correlated with plasma glutamine (p = 0.002) and arginine (p = 0.001) levels at baseline. After glutamine treatment, leptin was correlated with weight-for-age (WAZ) and weight-for-height z-scores (WHZ) (p≤0.002) at a 4-month follow-up. In addition, glutamine and all combined nutrients (glutamine, vitamin A, and zinc) improved the intestinal barrier function in these children. Taken together, these findings reveal the benefits of glutamine alone or in combination with other gut-trophic nutrients in growing children via interactions with leptin.

Elevated vacuum suspension preserves residual-limb skin health in people with lower-limb amputation: Randomized clinical trial.

PubMed

Rink, Cameron; Wernke, Matthew M; Powell, Heather M; Gynawali, Surya; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

2016-01-01

A growing number of clinical trials and case reports support qualitative claims that use of an elevated vacuum suspension (EVS) prosthesis improves residual-limb health on the basis of self-reported questionnaires, clinical outcomes scales, and wound closure studies. Here, we report first efforts to quantitatively assess residual-limb circulation in response to EVS. Residual-limb skin health and perfusion of people with lower-limb amputation (N = 10) were assessed during a randomized crossover study comparing EVS with nonelevated vacuum suspension (control) over a 32 wk period using noninvasive probes (transepidermal water loss, laser speckle imaging, transcutaneous oxygen measurement) and functional hyperspectral imaging approaches. Regardless of the suspension system, prosthesis donning decreased perfusion in the residual limb under resting conditions. After 16 wk of use, EVS improved residual-limb oxygenation during treadmill walking. Likewise, prosthesis-induced reactive hyperemia was attenuated with EVS following 16 wk of use. Skin barrier function was preserved with EVS but disrupted after control socket use. Taken together, outcomes suggest chronic EVS use improves perfusion and preserves skin barrier function in people with lower-limb amputation. ClinicalTrials.gov; "Evaluation of limb health associated with a prosthetic vacuum socket system": NCT01839123; https://clinicaltrials.gov/ct2/show/NCT01839123?term=NCT01839123&rank=1.

Evaluating the long-term hydrology of an evapotranspiration-capillary barrier with a 1000 year design life: HYDROLOGY OF A 1000 YEAR ETC BARRIER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Z. Fred

A surface barrier (or cover) is a commonly used technology for subsurface remediation. A key function of the barrier is to reduce or eliminate the movement of meteoric precipitation into the underlying waste zone, where it could mobilize and transport contaminants. Surface barriers are expected to perform for centuries to millennia, yet there are very few examples of performance for periods longer than a decade. The Prototype Hanford Barrier was constructed in 1994 over an existing waste site to demonstrate its long-term performance for a design period of 1000 years. This barrier is a field-scale evapotranspiration-capillary (ETC) barrier. In thismore » design, the storage layer consists of 2-m-thick silt loam. The 19-year monitoring results show that the store-and-release mechanism for the ETC barrier worked efficiently as the storage layer was recharged in the winter season (November to March) and the stored water was released to the atmosphere in the summer season (April to October) via soil evaporation and plant transpiration. The capillary break functioned normally in improving the storage capacity and minimizing drainage. The maximum drainage observed through the ET barrier at any of the monitoring stations was only 0.178 mm yr-1 (under an enhanced precipitation condition), which is less than the design criterion. A very small amount (2.0 mm yr-1 on average) of runoff was observed during the 19-year monitoring period. The observed storage capacity of the storage layer was considerably (39%) larger than the estimated value based on the method of equilibrium of water pressure. After a controlled fire in 2008, the newly grown vegetation (primarily shallow-rooted grasses) could still release the stored water and summer precipitation to the atmosphere via transpiration. The findings are useful for predicting water storage and ET under different precipitation conditions and for the design of future barriers.« less

High-fat enteral nutrition reduces intestinal mucosal barrier damage after peritoneal air exposure.

PubMed

Tan, Shan-Jun; Yu, Chao; Yu, Zhen; Lin, Zhi-Liang; Wu, Guo-Hao; Yu, Wen-Kui; Li, Jie-Shou; Li, Ning

2016-05-01

Peritoneal air exposure is needed in open abdominal surgery, but long-time exposure could induce intestinal mucosal barrier dysfunction followed by many postoperative complications. High-fat enteral nutrition can ameliorate intestinal injury and improve intestinal function in many gastrointestinal diseases. In the present study, we investigated the effect of high-fat enteral nutrition on intestinal mucosal barrier after peritoneal air exposure and the underlying mechanism. Male adult rats were administrated saline, low-fat or high-fat enteral nutrition via gavage before and after peritoneal air exposure for 3 h. Rats undergoing anesthesia without laparotomy received saline as control. Twenty four hours after surgery, samples were collected to assess intestinal mucosal barrier changes in serum D-lactate levels, intestinal permeability, intestinal tight junction protein ZO-1 and occludin levels, and intestinal histopathology. The levels of malondialdehyde and the activity of superoxide dismutase in the ileum tissue were also measured to assess the status of intestinal oxidative stress. High-fat enteral nutrition significantly decreased the serum D-lactate level and increased the intestinal tight junction protein ZO-1 level when compared to the group treated with low-fat enteral nutrition (P < 0.05). Meanwhile, histopathologic findings showed that the intestinal mucosal injury assessed by the Chiu's score and the intestinal epithelial tight junction were also improved much more in the high-fat enteral nutrition-treated group (P < 0.05). In addition, the intestinal malondialdehyde level was lower, and the intestinal superoxide dismutase activity was higher in the high-fat enteral nutrition-treated group than that in the low-fat enteral nutrition-treated group (P < 0.05). These results suggest that high-fat enteral nutrition could reduce intestinal mucosal barrier damage after peritoneal air exposure, and the underlying mechanism may be associated with its antioxidative action. Perioperative administration of high-fat enteral nutrition may be a promising intervention to preserve intestinal mucosal barrier function in open abdominal surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of the Efficacy of Atopalm(®) Multi-Lamellar Emulsion Cream and Physiogel(®) Intensive Cream in Improving Epidermal Permeability Barrier in Sensitive Skin.

PubMed

Jeong, Sekyoo; Lee, Sin Hee; Park, Byeong Deog; Wu, Yan; Man, George; Man, Mao-Qiang

2016-03-01

The management of sensitive skin, which affects over 60% of the general population, has been a long-standing challenge for both patients and clinicians. Because defective epidermal permeability barrier is one of the clinical features of sensitive skin, barrier-enhancing products could be an optimal regimen for sensitive skin. In the present study, we evaluated the efficacy and safety of two barrier-enhancing products, i.e., Atopalm (®) Multi-Lamellar Emulsion (MLE) Cream and Physiogel (®) Intensive Cream for sensitive skin. 60 patients with sensitive skin, aged 22-40 years old, were randomly assigned to one group treated with Atopalm MLE Cream, and another group treated with Physiogel Intensive Cream twice daily for 4 weeks. Lactic acid stinging test scores (LASTS), stratum hydration (SC) and transepidermal water loss (TEWL) were assessed before, 2 and 4 weeks after the treatment. Atopalm MLE Cream significantly lowered TEWL after 2 and 4 weeks of treatment (p < 0.01). In contrast, Physiogel Intensive Cream significantly increased TEWL after 2 weeks of treatment (p < 0.05) while TEWL significantly decreased after 4-week treatments. Moreover, both Atopalm MLE Cream and Physiogel Intensive Cream significantly increased SC hydration, and improved LASTS after 4 weeks of treatment. Both barrier-enhancing products are effective and safe for improving epidermal functions, including permeability barrier, SC hydration and LASTS, in sensitive skin. These products could be a valuable alternative for management of sensitive skin. Veterans Affairs Medical Center, San Francisco, California, USA, and NeoPharm Co., Ltd., Daejeon, Korea.

Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

PubMed

Schweitzer, Kelly S; Chen, Steven X; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J; Hubbard, Walter C; Kim, Elena S; Lai, Xianyin; Wang, Mu; Kranz, William D; Carroll, Clinton J; Ray, Bruce D; Bittman, Robert; Goodpaster, John; Petrache, Irina

2015-07-15

The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation.

cAMP-dependent activation of protein kinase A attenuates respiratory syncytial virus-induced human airway epithelial barrier disruption

PubMed Central

Harford, Terri J.; Linfield, Debra T.; Altawallbeh, Ghaith; Midura, Ronald J.; Ivanov, Andrei I.; Piedimonte, Giovanni

2017-01-01

Airway epithelium forms a barrier to the outside world and has a crucial role in susceptibility to viral infections. Cyclic adenosine monophosphate (cAMP) is an important second messenger acting via two intracellular signaling molecules: protein kinase A (PKA) and the guanidine nucleotide exchange factor, Epac. We sought to investigate effects of increased cAMP level on the disruption of model airway epithelial barrier caused by RSV infection and the molecular mechanisms underlying cAMP actions. Human bronchial epithelial cells were infected with RSV-A2 and treated with either cAMP releasing agent, forskolin, or cAMP analogs. Structure and functions of the Apical Junctional Complex (AJC) were evaluated by measuring transepithelial electrical resistance and permeability to FITC-dextran, and determining localization of AJC proteins by confocal microscopy. Increased intracellular cAMP level significantly attenuated RSV-induced disassembly of AJC. These barrier-protective effects of cAMP were due to the activation of PKA signaling and did not involve Epac activity. Increased cAMP level reduced RSV-induced reorganization of the actin cytoskeleton, including apical accumulation of an essential actin-binding protein, cortactin, and inhibited expression of the RSV F protein. These barrier-protective and antiviral-function of cAMP signaling were evident even when cAMP level was increased after the onset of RSV infection. Taken together, our study demonstrates that cAMP/PKA signaling attenuated RSV-induced disruption of structure and functions of the model airway epithelial barrier by mechanisms involving the stabilization of epithelial junctions and inhibition of viral biogenesis. Improving our understanding of the mechanisms involved in RSV-induced epithelial dysfunction and viral pathogenesis will help to develop novel anti-viral therapeutic approaches. PMID:28759570

[Case managers experience improved trajectories for cancer patients after implementation of the case manager function].

PubMed

Axelsen, Karina Rahbek; Nafei, Hanne; Jakobsen, Stine Finne; Gandrup, Per; Knudsen, Janne Lehmann

2015-06-08

Case managers are increasingly used to optimize trajectories for patients. This study is based on a questionnaire among case managers in cancer care, aiming at the clarification of the func­tion and its impact on especially patient safety, when handing over the responsibility. The results show a major variation in how the function is organized, the level of competence and the task to be handled. The responsibility has in general been nar­rowed to department level. Overall, the case managers believe that the function has optimized pathways for cancer patients and improved safety, but barriers persist.

Intermedin Stabilized Endothelial Barrier Function and Attenuated Ventilator-induced Lung Injury in Mice

PubMed Central

Müller-Redetzky, Holger Christian; Kummer, Wolfgang; Pfeil, Uwe; Hellwig, Katharina; Will, Daniel; Paddenberg, Renate; Tabeling, Christoph; Hippenstiel, Stefan; Suttorp, Norbert; Witzenrath, Martin

2012-01-01

Background Even protective ventilation may aggravate or induce lung failure, particularly in preinjured lungs. Thus, new adjuvant pharmacologic strategies are needed to minimize ventilator-induced lung injury (VILI). Intermedin/Adrenomedullin-2 (IMD) stabilized pulmonary endothelial barrier function in vitro. We hypothesized that IMD may attenuate VILI-associated lung permeability in vivo. Methodology/Principal Findings Human pulmonary microvascular endothelial cell (HPMVEC) monolayers were incubated with IMD, and transcellular electrical resistance was measured to quantify endothelial barrier function. Expression and localization of endogenous pulmonary IMD, and its receptor complexes composed of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs) 1–3 were analyzed by qRT-PCR and immunofluorescence in non ventilated mouse lungs and in lungs ventilated for 6 h. In untreated and IMD treated mice, lung permeability, pulmonary leukocyte recruitment and cytokine levels were assessed after mechanical ventilation. Further, the impact of IMD on pulmonary vasoconstriction was investigated in precision cut lung slices (PCLS) and in isolated perfused and ventilated mouse lungs. IMD stabilized endothelial barrier function in HPMVECs. Mechanical ventilation reduced the expression of RAMP3, but not of IMD, CRLR, and RAMP1 and 2. Mechanical ventilation induced lung hyperpermeability, which was ameliorated by IMD treatment. Oxygenation was not improved by IMD, which may be attributed to impaired hypoxic vasoconstriction due to IMD treatment. IMD had minor impact on pulmonary leukocyte recruitment and did not reduce cytokine levels in VILI. Conclusions/Significance IMD may possibly provide a new approach to attenuate VILI. PMID:22563471

Glucocorticoid action in human corneal epithelial cells establishes roles for corticosteroids in wound healing and barrier function of the eye.

PubMed

Kadmiel, Mahita; Janoshazi, Agnes; Xu, Xiaojiang; Cidlowski, John A

2016-11-01

Glucocorticoids play diverse roles in almost all physiological systems of the body, including both anti-inflammatory and immunosuppressive roles. Synthetic glucocorticoids are one of the most widely prescribed drugs and are used in the treatment of conditions such as autoimmune diseases, allergies, ocular disorders and certain types of cancers. In the interest of investigating glucocorticoid actions in the cornea of the eye, we established that multiple cell types in mouse corneas express functional glucocorticoid receptor (GR) with corneal epithelial cells having robust expression. To define glucocorticoid actions in a cell type-specific manner, we employed immortalized human corneal epithelial (HCE) cell line to define the glucocorticoid transcriptome and elucidated its functions in corneal epithelial cells. Over 4000 genes were significantly regulated within 6 h of dexamethasone treatment, and genes associated with cell movement, cytoskeletal remodeling and permeability were highly regulated. Real-time in vitro wound healing assays revealed that glucocorticoids delay wound healing by attenuating cell migration. These functional alterations were associated with cytoskeletal remodeling at the wounded edge of a scratch-wounded monolayer. However, glucocorticoid treatment improved the organization of tight-junction proteins and enhanced the epithelial barrier function. Our results demonstrate that glucocorticoids profoundly alter corneal epithelial gene expression and many of these changes likely impact both wound healing and epithelial cell barrier function. Published by Elsevier Ltd.

Inhibition of nuclear factor of activated T cells (NFAT) c3 activation attenuates acute lung injury and pulmonary edema in murine models of sepsis

PubMed Central

Karpurapu, Manjula; Lee, Yong Gyu; Qian, Ziqing; Wen, Jin; Ballinger, Megan N.; Rusu, Luiza; Chung, Sangwoon; Deng, Jing; Qian, Feng; Reader, Brenda F.; Nirujogi, Teja Srinivas; Park, Gye Young; Pei, Dehua; Christman, John W.

2018-01-01

Specific therapies targeting cellular and molecular events of sepsis induced Acute Lung Injury (ALI) pathogenesis are lacking. We have reported a pivotal role for Nuclear Factors of Activated T cells (NFATc3) in regulating macrophage phenotype during sepsis induced ALI and subsequent studies demonstrate that NFATc3 transcriptionally regulates macrophage CCR2 and TNFα gene expression. Mouse pulmonary microvascular endothelial cell monolayer maintained a tighter barrier function when co-cultured with LPS stimulated NFATc3 deficient macrophages whereas wild type macrophages caused leaky monolayer barrier. More importantly, NFATc3 deficient mice showed decreased neutrophilic lung inflammation, improved alveolar capillary barrier function, arterial oxygen saturation and survival benefit in lethal CLP sepsis mouse models. In addition, survival of wild type mice subjected to the lethal CLP sepsis was not improved with broad-spectrum antibiotics, whereas the survival of NFATc3 deficient mice was improved to 40–60% when treated with imipenem. Passive adoptive transfer of NFATc3 deficient macrophages conferred protection against LPS induced ALI in wild type mice. Furthermore, CP9-ZIZIT, a highly potent, cell-permeable peptide inhibitor of Calcineurin inhibited NFATc3 activation. CP9-ZIZIT effectively reduced sepsis induced inflammatory cytokines and pulmonary edema in mice. Thus, this study demonstrates that inhibition of NFATc3 activation by CP9-ZIZIT provides a potential therapeutic option for attenuating sepsis induced ALI/pulmonary edema. PMID:29535830

Feasibility of antihydrogen atom containment in helium: a problem of electron-positron correlation investigated by the Monte Carol method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackman, T.M.

1987-01-01

A theoretical investigation of the interaction potential between the helium atom and the antihydrogen atom was performed for the purpose of determining the feasibility of antihydrogen atom containment. The interaction potential showed an energy barrier to collapse of this system. A variational estimate of the height of this energy barrier and estimates of lifetime with respect to electron-positron annihilation were determined by the Variational Monte Carlo method. This calculation allowed for an improvement over an SCF result through the inclusion of explicit correlation factors in the trial wave function. An estimate of the correlation energy of this system was determinedmore » by the Green's Function Monte Carlo (GFMC) method.« less

Effects of Locally Applied Glycerol and Xylitol on the Hydration, Barrier Function and Morphological Parameters of the Skin.

PubMed

Korponyai, Csilla; Szél, Edit; Behány, Zoltán; Varga, Erika; Mohos, Gábor; Dura, Ágnes; Dikstein, Shabtay; Kemény, Lajos; Erős, Gábor

2017-02-08

Glycerol and xylitol hydrate the skin and improve its barrier function over a short period. We studied the effects of glycerol and xylitol on the physiological properties and morphology of the skin after longer-term application. Twelve volunteers with dry skin were examined. Three areas on the arms were determined. Area 1 served as untreated control. The vehicle was applied to area 2, while area 3 was treated twice daily with a formulation containing glycerol (5%) and xylitol (5%) for 14 days. Transepidermal water loss (TEWL), hydration and biomechanical properties of the skin were monitored. Biopsies were taken for routine histology and immunohistochemistry for filaggrin and matrix metalloproteinase-1 (MMP-1). The polyols increased the skin hydration and protein quantity of filaggrin, elevated the interdigitation index, decreased the TEWL and improved the biomechanical properties of the skin, but did not change the protein expression of MMP-1. A combination of glycerol and xylitol can be useful additional therapy for dry skin.

Clinical effectiveness of low-power laser radiation and functioning of hemosalivatory barrier in patients with rheumatic diseases

NASA Astrophysics Data System (ADS)

Gladkova, Natalia D.; Karachistov, Alexander B.; Komarova, Lia G.; Alekseeva, Olga P.; Grunina, Elena A.

1996-11-01

We have estimated the clinical effectiveness of several regimes and ways of low power laser therapy (LT) on the basis of a double 'blind', placebo-controlling randomizing comparative test in 454 patients with rheumatic diseases (RD). LT for RD has a well-expressed placebo effect. The level of clinical effect of LT for RD is not so high. We couldn't achieve 'a considerable improvement' in any cases, 'an improvement' was secured in only 18 percent. LT should be viewed as a symptomatic means, with a primary anesthetic and feebly expressed anti-inflammatory effect, which can not influence the course of the rheumatoid process. Only in 15 percent of patients with RD, a sufficient functioning of hemo-salivary barrier was observed, the latter providing a reserve for adaption mechanism, which leads under the influence of stressor agents of medium strength not only to anesthetic, but also to moderately expressed anti- inflammatory effect.

Carbon-based sputtered coatings for enhanced chitosan-based films properties

NASA Astrophysics Data System (ADS)

Fernandes, C.; Calderon V., S.; Ballesteros, Lina F.; Cerqueira, Miguel A.; Pastrana, L. M.; Teixeira, José A.; Ferreira, P. J.; Carvalho, S.

2018-03-01

In order to make bio-based packaging materials competitive in comparison to petroleum-based one, some of their properties need to be improved, among which gas permeability is of crucial importance. Thus, in this work, carbon-based coatings were applied on chitosan-based films by radiofrequency reactive magnetron sputtering aiming to improve their barrier properties. Chemical and morphological properties were evaluated in order to determine the effect of the coatings on the chemical structure, surface hydrophobicity and barrier properties of the system. Chemical analysis, performed by electron energy loss spectroscopy and Fourier transform infrared spectroscopy, suggests similar chemical characteristics among all coatings although higher incorporation of hydrogen as the acetylene flux increases was observed. On the other hand, scanning transmission electron microscopy revealed that the porosity of the carbon layer can be tailored by the acetylene flux. More importantly, the chitosan oxygen permeability showed a monotonic reduction as a function of the acetylene flux. This study opens up new opportunities to apply nanostructured coatings on bio-based polymer for enhanced oxygen barrier properties.

Pathways to Depression Care: Help-Seeking Experiences of Low-Income Latinos with Diabetes and Depression

PubMed Central

Cabassa, Leopoldo J.

2013-01-01

This qualitative study examines help-seeking pathways to depression care of low-income Latinos with diabetes and major depression. A purposive sample (N = 19) of Spanish-speaking, immigrant, low-income Latinos was selected from a randomized clinical trial targeting Latinos with diabetes and major depression. Four focus groups followed by 10 in-depth qualitative interviews were conducted. Narratives were analyzed using the constant comparative method informed by grounded theory. Need for formal care was described in relation to acute somatic symptoms, functional impairment, and mood changes. Treatment initiation occurred through family members and primary care physicians who encouraged or inhibited help-seeking. Adherence to depression care focused on interpersonal aspects of care, evaluated symptom relief, and improved functioning. Help-seeking barriers included self-reliance, language barriers, stigma, competing health demands, and structural barriers. Findings from this study highlight potential points of intervention for developing culturally-appropriate collaborative care approaches for low-income Latinos with diabetes and major depression. PMID:22367667

From clinical uncertainties to precision medicine: the emerging role of the gut barrier and microbiome in small bowel functional diseases.

PubMed

Marlicz, Wojciech; Yung, Diana E; Skonieczna-Żydecka, Karolina; Loniewski, Igor; van Hemert, Saskia; Loniewska, Beata; Koulaouzidis, Anastasios

2017-10-01

Over the last decade, remarkable progress has been made in the understanding of disease pathophysiology. Many new theories expound on the importance of emerging factors such as microbiome influences, genomics/omics, stem cells, innate intestinal immunity or mucosal barrier complexities. This has introduced a further dimension of uncertainty into clinical decision-making, but equally, may shed some light on less well-understood and difficult to manage conditions. Areas covered: Comprehensive review of the literature on gut barrier and microbiome relevant to small bowel pathology. A PubMed/Medline search from 1990 to April 2017 was undertaken and papers from this range were included. Expert commentary: The scenario of clinical uncertainty is well-illustrated by functional gastrointestinal disorders (FGIDs). The movement towards achieving a better understanding of FGIDs is expressed in the Rome IV guidelines. Novel diagnostic and therapeutic protocols focused on the GB and SB microbiome can facilitate diagnosis, management and improve our understanding of the underlying pathological mechanisms in FGIDs.

Self-care and quality of life of heart failure patients at a multidisciplinary heart function clinic.

PubMed

Seto, Emily; Leonard, Kevin J; Cafazzo, Joseph A; Masino, Caterina; Barnsley, Jan; Ross, Heather J

2011-01-01

Multidisciplinary heart function clinics aim to improve self-care through patient education and to provide clinical management. The objectives of the present study were to investigate the self-care and quality of life of patients attending a multidisciplinary heart function clinic and to explore the relationship between self-care and quality of life. One hundred outpatients attending a multidisciplinary heart function clinic were asked to complete a questionnaire. The questionnaire included the Self-care of Heart Failure Index (SCHFI) and the Minnesota Living With Heart Failure Questionnaire, which were used to assess self-care behavior and quality of life, respectively. Self-care practices and perceived barriers were also assessed through semistructured interviews with each patient. : The returned questionnaires (n = 94) were used to compute the following SCHFI maintenance, management, and confidence scores: 60.8 (SD, 19.3), 62.0 (SD, 20.7), and 55.9 (SD, 19.7), respectively. Higher SCHFI scores indicate better self-care. None of the self-care dimensions reached the self-care adequacy cut point of 70. The average score on the Minnesota Living With Heart Failure Questionnaire was 49.9 (SD, 25.4), indicating a moderate health-related quality of life. Lower ejection fraction, older age, and better quality of life were associated with better self-care. Determinants of better quality of life were older age, better functional capacity, higher self-care confidence, and fewer comorbidities. The patient interviews revealed that better quality of life is associated with higher self-care confidence and barriers to self-care caused anxiety to the patients. The self-care barriers were found to include lack of self-care education, financial constraints, lack of perceived benefit, and low self-efficacy. Patients attending a large multidisciplinary Canadian heart failure clinic do not perform adequate self-care as measured with the SCHFI and report only a moderate quality of life. Increasing self-care through education and tools that target self-care barriers are required and may help improve quality of life.

Patient-clinician communication about end-of-life care for Dutch and US patients with COPD.

PubMed

Janssen, D J A; Curtis, J R; Au, D H; Spruit, M A; Downey, L; Schols, J M G A; Wouters, E F M; Engelberg, R A

2011-08-01

Improving patient-clinician communication about end-of-life care is important in order to enhance quality of care for patients with chronic obstructive pulmonary disease (COPD). Our objective was to compare quality of patient-clinician communication about end-of-life care, and endorsement of barriers and facilitators to this communication in the Netherlands and the USA. The present study was an analysis of survey data from 122 Dutch and 391 US outpatients with COPD. We compared quality of patient-clinician communication about end-of-life care (Quality of Communication questionnaire) and barriers and facilitators to communication about end-of-life care (Barriers and Facilitators Questionnaire) between the Netherlands and the USA, controlling for patients' demographic and illness characteristics. Although Dutch patients in this study had worse lung function and disease-specific health status than US patients, Dutch patients reported lower quality of communication about end-of-life care (median score 0.0 (interquartile range 0.0-2.0) versus 1.4 (0.0-3.6); adjusted p<0.005). Clinicians in both countries rarely discussed life-sustaining treatment preferences, prognoses, dying processes or spiritual issues. Quality of communication about end-of-life care needs to improve in the Netherlands and the USA. Future studies to improve this communication should be designed to take into account international differences and patient-specific barriers and facilitators to communication about end-of-life care.

Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction.

PubMed

Czikora, Istvan; Sridhar, Supriya; Gorshkov, Boris; Alieva, Irina B; Kasa, Anita; Gonzales, Joyce; Potapenko, Olena; Umapathy, Nagavedi S; Pillich, Helena; Rick, Ferenc G; Block, Norman L; Verin, Alexander D; Chakraborty, Trinad; Matthay, Michael A; Schally, Andrew V; Lucas, Rudolf

2014-01-01

Antibiotic treatment of patients infected with G(-) or G(+) bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion. Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting. GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the former of which dominates the latter.

A feasibility study of expert patient and community mental health team led bipolar psychoeducation groups: implementing an evidence based practice

PubMed Central

2013-01-01

Background Group psychoeducation is a cost effective intervention which reduces relapse and improves functioning in bipolar disorder but is rarely implemented. The aim of this study was to identify the acceptability and feasibility of a group psychoeducation programme delivered by community mental health teams (CMHTs) and peer specialist (PS) facilitators. Organisational learning was used to identify and address systematically barriers and enablers, at organisational, health professional and patient levels, to its implementation into a routine service. Methods A systematic examination of barriers and enablers to a three day training process informed the delivery of a first treatment group and a similar process informed the delivery of the second treatment group. Triangulation of research methods improved its internal validity: direct observation of training, self-rated surveys of participant experiences, group discussion, and thematically analysed individual participant and facilitator interviews were employed. Results Barriers and enablers were identified at organisational, educational, treatment content, facilitator and patient levels. All barriers under the control of the research team were addressed with subsequent improvements in patient knowledge about the condition and about local service. In addition, self-management, agency and altruism were enhanced. Barriers that could not be addressed required senior clinical and education leadership outside the research team’s control. PS and professional facilitators were successfully trained and worked together to deliver groups which were generally reported as being beneficial. Conclusion Psychoeducation groups involving CMHT and PS facilitators is acceptable and feasible but their sustainment requires senior leadership within and outside the organisation that control finance and education services. PMID:24215655

Understanding collaborative care implementation in the Department of Veterans Affairs: core functions and implementation challenges.

PubMed

Lipschitz, Jessica M; Benzer, Justin K; Miller, Christopher; Easley, Siena R; Leyson, Jenniffer; Post, Edward P; Burgess, James F

2017-10-10

The collaborative care model is an evidence-based practice for treatment of depression in which designated care managers provide clinical services, often by telephone. However, the collaborative care model is infrequently adopted in the Department of Veterans Affairs (VA). Almost all VA medical centers have adopted a co-located or embedded approach to integrating mental health care for primary care patients. Some VA medical centers have also adopted a telephone-based collaborative care model where depression care managers support patient education, patient activation, and monitoring of adherence and progress over time. This study evaluated two research questions: (1) What does a dedicated care manager offer in addition to an embedded-only model? (2) What are the barriers to implementing a dedicated depression care manager? This study involved 15 qualitative, multi-disciplinary, key informant interviews at two VA medical centers where reimbursement options were the same- both with embedded mental health staff, but one with a depression care manager. Participant interviews were recorded and transcribed. Thematic analysis was used to identify descriptive and analytical themes. Findings suggested that some of the core functions of depression care management are provided as part of embedded-only mental health care. However, formal structural attention to care management may improve the reliability of care management functions, in particular monitoring of progress over time. Barriers to optimal implementation were identified at both sites. Themes from the care management site included finding assertive care managers to hire, cross-discipline integration and collaboration, and primary care provider burden. Themes from interviews at the embedded site included difficulty getting care management on leaders' agendas amidst competing priorities and logistics (staffing and space). Providers and administrators see depression care management as a valuable healthcare service that improves patient care. Barriers to implementation may be addressed by team-building interventions to improve cross-discipline integration and communication. Findings from this study are limited in scope to the VA healthcare system. Future investigation of whether alternative barriers exist in implementation of depression care management programs in non-VA hospital systems, where reimbursement rates may be a more prominent concern, would be valuable.

Biologic Treatments for Sports Injuries II Think Tank—Current Concepts, Future Research, and Barriers to Advancement, Part 2

PubMed Central

Murray, Iain R.; LaPrade, Robert F.; Musahl, Volker; Geeslin, Andrew G.; Zlotnicki, Jason P.; Mann, Barton J.; Petrigliano, Frank A.

2016-01-01

Rotator cuff tears are common and result in considerable morbidity. Tears within the tendon substance or at its insertion into the humeral head represent a considerable clinical challenge because of the hostile local environment that precludes healing. Tears often progress without intervention, and current surgical treatments are inadequate. Although surgical implants, instrumentation, and techniques have improved, healing rates have not improved, and a high failure rate remains for large and massive rotator cuff tears. The use of biologic adjuvants that contribute to a regenerative microenvironment have great potential for improving healing rates and function after surgery. This article presents a review of current and emerging biologic approaches to augment rotator cuff tendon and muscle regeneration focusing on the scientific rationale, preclinical, and clinical evidence for efficacy, areas for future research, and current barriers to advancement and implementation. PMID:27099865

A Tannic Acid-based Medical Food, Cesinex®, Exhibits Broad-spectrum Antidiarrheal Properties: a Mechanistic and Clinical Study

PubMed Central

Ren, Aixia; Zhang, Weiqiang; Thomas, Hugh Greg; Barish, Amy; Berry, Stephen; Kiel, Jeffrey S.

2011-01-01

Background To evaluate the efficacy and tolerability of a tannic acid-based medical food, Cesinex®, in the treatment of diarrhea, and to investigate the mechanisms underlying its antidiarrheal effect. Methods Cesinex® was prescribed to six children and four adults with diarrhea. Patient records were retrospectively reviewed for the primary outcome. Cesinex® and its major component, tannic acid, were tested for their effects on cholera toxin-induced intestinal fluid secretion in mouse. Polarized human gut epithelial cells (HT29-CL19A cells) were used to investigate the effects of tannic acid on epithelial barrier properties, transepithelial chloride secretion, and cell viability. Results Successful resolution of diarrheal symptoms was reported in nine of ten patients receiving Cesinex®. Treatment of HT29-CL19A cells with clinically relevant concentrations of tannic acid (0.01–1 mg/ml) significantly increased transepithelial resistance and inhibited the CFTR-dependent or the calcium-activated Cl− secretion. Tannic acid could also improve the impaired epithelial barrier function induced by TNFα and inhibited the disrupting effect of TNFα on the epithelial barrier function in these cells. CTX-induced mouse intestinal fluid secretion was significantly reduced by administration of Cesinex® or tannic acid. Cesinex® has high antioxidant capacity. Conclusions Cesinex® demonstrates an effective and safety profile in treatment of diarrhea. The broad-spectrum antidiarrheal effect of Cesinex® can be attributed to a combination of factors: its ability to improve the epithelial barrier properties, to inhibit intestinal fluid secretion, and the high antioxidant property. PMID:21748285

Two randomized, controlled, comparative studies of the stratum corneum integrity benefits of two cosmetic niacinamide/glycerin body moisturizers vs. conventional body moisturizers.

PubMed

Christman, Jeremy C; Fix, Deborah K; Lucus, Sawanna C; Watson, Debrah; Desmier, Emma; Wilkerson, Rolanda J Johnson; Fixler, Charles

2012-01-01

Despite numerous body moisturizers being available, cosmetic xerosis continues to be a leading skin problem for consumers. We performed two 35-day studies to evaluate the ability of a variety of body moisturizers containing various levels of oils/lipids, humectants, as well as other ingredients (e.g., niacinamide) to improve stratum corneum integrity. 63 and 58 female subjects were enrolled and randomized in an incomplete block design to six of nine products (eight moisturizers or no treatment control) in studies 1 and 2, respectively. The primary endpoints included visual dryness by a qualified skin grader, skin hydration as measured by Corneometer, and barrier integrity as measured by transepidermal water loss (TEWL). The primary comparisons for the two niacinamide/glycerin moisturizers were to the other six moisturizers and to the no treatment control for each endpoint. The two niacinamide/glycerin moisturizers demonstrated an overall better solution towards rapid and prolonged improvement of cosmetic xerosis due to functional improvement of stratum corneum barrier function compared to no treatment and the other moisturizers tested. These studies establish the benefit of including niacinamide in a body moisturizer to improve the integrity of the stratum corneum and thus reduce cosmetic xerosis over time.

Effects of Mindfulness Training on Body Awareness to Sexual Stimuli: Implications for Female Sexual Dysfunction

PubMed Central

Silverstein, R. Gina; Brown, Anne-Catharine H.; Roth, Harold D.; Britton, Willoughby B.

2013-01-01

Objectives Treatments of female sexual dysfunction have been largely unsuccessful because they do not address the psychological factors that underlie female sexuality. Negative self-evaluative processes interfere with the ability to attend and register physiological changes (interoceptive awareness). This study explores the effect of mindfulness meditation training on interoceptive awareness and the three categories of known barriers to healthy sexual functioning: attention, self-judgment, and clinical symptoms. Methods Forty-four college students (30 women) participated in either a 12-week course containing a “meditation laboratory” or an active control course with similar content or laboratory format. Interoceptive awareness was measured by reaction time in rating physiological response to sexual stimuli. Psychological barriers were assessed with self-reported measures of mindfulness and psychological well-being. Results Women who participated in the meditation training became significantly faster at registering their physiological responses (interoceptive awareness) to sexual stimuli compared with active controls (F(1,28) = 5.45, p = .03, ηp2 = 0.15). Female meditators also improved their scores on attention (t = 4.42, df = 11, p = .001), self-judgment, (t = 3.1, df = 11, p = .01), and symptoms of anxiety (t = −3.17, df = 11, p = .009) and depression (t = −2.13, df = 11, p < .05). Improvements in interoceptive awareness were correlated with improvements in the psychological barriers to healthy sexual functioning (r = −0.44 for attention, r = −0.42 for self-judgment, and r = 0.49 for anxiety; all p < .05). Conclusions Mindfulness-based improvements in interoceptive awareness highlight the potential of mindfulness training as a treatment of female sexual dysfunction. PMID:22048839

Liver Ischemic Preconditioning (IPC) Improves Intestinal Microbiota Following Liver Transplantation in Rats through 16s rDNA-Based Analysis of Microbial Structure Shift

PubMed Central

Lu, Haifeng; Chen, Xinhua; Jiang, Jianwen; Liu, Hui; He, Yong; Ding, Songming; Hu, Zhenhua; Wang, Weilin; Zheng, Shusen

2013-01-01

Background Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The “gut-liver axis” closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT). Methods The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis. Principal Findings Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum. Conclusion Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the “gut-liver axis”. PMID:24098410

Liver ischemic preconditioning (IPC) improves intestinal microbiota following liver transplantation in rats through 16s rDNA-based analysis of microbial structure shift.

PubMed

Ren, Zhigang; Cui, Guangying; Lu, Haifeng; Chen, Xinhua; Jiang, Jianwen; Liu, Hui; He, Yong; Ding, Songming; Hu, Zhenhua; Wang, Weilin; Zheng, Shusen

2013-01-01

Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The "gut-liver axis" closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT). The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis. Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum. Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the "gut-liver axis".

The barrier function of organotypic non-melanoma skin cancer models.

PubMed

Zoschke, Christian; Ulrich, Martina; Sochorová, Michaela; Wolff, Christopher; Vávrová, Kateřina; Ma, Nan; Ulrich, Claas; Brandner, Johanna M; Schäfer-Korting, Monika

2016-07-10

Non-melanoma skin cancer (NMSC) is the most frequent human cancer with continuously rising incidences worldwide. Herein, we investigated the molecular basis for the impaired skin barrier function of organotypic NMSC models. We unraveled disturbed epidermal differentiation by reflectance confocal microscopy and histopathological evaluation. While the presence of claudin-4 and occludin were distinctly reduced, zonula occludens protein-1 was more wide-spread, and claudin-1 was heterogeneously distributed within the NMSC models compared with normal reconstructed human skin. Moreover, the cancer altered stratum corneum lipid packing and profile with decreased cholesterol content, increased phospholipid amount, and altered ceramide subclasses. These alterations contributed to increased surface pH and to 1.5 to 2.6-fold enhanced caffeine permeability of the NMSC models. Three topical applications of ingenol mebutate gel (0.015%) caused abundant epidermal cell necrosis, decreased Ki-67 indices, and increased lactate dehydrogenase activity. Taken together, our study provides new biological insights into the microenvironment of organotypic NMSC models, improves the understanding of the disease model by revealing causes for impaired skin barrier function in NMSC models at the molecular level, and fosters human cell-based approaches in preclinical drug evaluation. Copyright © 2016 Elsevier B.V. All rights reserved.

Improved Work Function of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonic acid) and its Effect on Hybrid Silicon/Organic Heterojunction Solar Cells.

PubMed

Shen, Xiaojuan; Chen, Ling; Pan, Jianmei; Hu, Yue; Li, Songjun; Zhao, Jie

2016-12-01

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (H 2 PtCl 6 ) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to ~20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.

Improved Work Function of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonic acid) and its Effect on Hybrid Silicon/Organic Heterojunction Solar Cells

NASA Astrophysics Data System (ADS)

Shen, Xiaojuan; Chen, Ling; Pan, Jianmei; Hu, Yue; Li, Songjun; Zhao, Jie

2016-11-01

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (H2PtCl6) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to 20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.

Functionalized low defect graphene nanoribbons and polyurethane composite film for improved gas barrier and mechanical performances.

PubMed

Xiang, Changsheng; Cox, Paris J; Kukovecz, Akos; Genorio, Bostjan; Hashim, Daniel P; Yan, Zheng; Peng, Zhiwei; Hwang, Chih-Chau; Ruan, Gedeng; Samuel, Errol L G; Sudeep, Parambath M; Konya, Zoltan; Vajtai, Robert; Ajayan, Pulickel M; Tour, James M

2013-11-26

A thermoplastic polyurethane (TPU) composite film containing hexadecyl-functionalized low-defect graphene nanoribbons (HD-GNRs) was produced by solution casting. The HD-GNRs were well distributed within the polyurethane matrix, leading to phase separation of the TPU. Nitrogen gas effective diffusivity of TPU was decreased by 3 orders of magnitude with only 0.5 wt % HD-GNRs. The incorporation of HD-GNRs also improved the mechanical properties of the composite films, as predicted by the phase separation and indicated by tensile tests and dynamic mechanical analyses. The improved properties of the composite film could lead to potential applications in food packaging and lightweight mobile gas storage containers.

Computational study of energy filtering effects in one-dimensional composite nano-structures

NASA Astrophysics Data System (ADS)

Kim, Raseong; Lundstrom, Mark S.

2012-01-01

Possibilities to improve the Seebeck coefficient S versus electrical conductance G trade-off of diffusive composite nano-structures are explored using an electro-thermal simulation framework based on the non-equilibrium Green's function method for quantum electron transport and the lattice heat diffusion equation. We examine the role of the grain size d, potential barrier height ΦB, grain doping, and the lattice thermal conductivity κL using a one-dimensional model structure. For a uniform κL, simulation results show that the power factor of a composite structure may be improved over bulk with the optimum ΦB being about kBT, where kB and T are the Boltzmann constant and the temperature, respectively. An optimum ΦB occurs because the current flow near the Fermi level is not obstructed too much while S still improves due to barriers. The optimum grain size dopt is significantly longer than the momentum relaxation length λp so that G is not seriously degraded due to the barriers, and dopt is comparable to or somewhat larger than the energy relaxation length λE so that the carrier energy is not fully relaxed within the grain and |S| remains high. Simulation results also show that if κL in the barrier region is smaller than in the grain, S and power factor are further improved. In such cases, the optimum ΦB and dopt increase, and the power factor may improve even for ΦB (d) significantly higher (longer) than kBT (λE). We find that the results from this quantum mechanical approach are readily understood using a simple, semi-classical model.

Potential barrier classification by short-time measurement

NASA Astrophysics Data System (ADS)

Granot, Er'El; Marchewka, Avi

2006-03-01

We investigate the short-time dynamics of a delta-function potential barrier on an initially confined wave packet. There are mainly two conclusions: (A) At short times the probability density of the first particles that passed through the barrier is unaffected by it. (B) When the barrier is absorptive (i.e., its potential is imaginary) it affects the transmitted wave function at shorter times than a real potential barrier. Therefore, it is possible to distinguish between an imaginary and a real potential barrier by measuring its effect at short times only on the transmitting wave function.

Enhancing metal-insulator-insulator-metal tunnel diodes via defect enhanced direct tunneling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alimardani, Nasir; Conley, John F., E-mail: jconley@eecs.oregonstate.edu

Metal-insulator-insulator-metal tunnel diodes with dissimilar work function electrodes and nanolaminate Al{sub 2}O{sub 3}-Ta{sub 2}O{sub 5} bilayer tunnel barriers deposited by atomic layer deposition are investigated. This combination of high and low electron affinity insulators, each with different dominant conduction mechanisms (tunneling and Frenkel-Poole emission), results in improved low voltage asymmetry and non-linearity of current versus voltage behavior. These improvements are due to defect enhanced direct tunneling in which electrons transport across the Ta{sub 2}O{sub 5} via defect based conduction before tunneling directly through the Al{sub 2}O{sub 3}, effectively narrowing the tunnel barrier. Conduction through the device is dominated by tunneling,more » and operation is relatively insensitive to temperature.« less

Evaluation of skin surface hydration state and barrier function of stratum corneum of dorsa of hands and heels treated with PROTECT X2 skin protective cream.

PubMed

Kubota, Takahiro

2012-06-01

Skin roughness is a term commonly used in Japan to describe a poor skin condition related to a rough and dry skin surface that develops as a result of various damaging effects from the environment or skin inflammation. Recovery from skin roughness requires skin care for a long period, thus it is important to prevent development of such skin changes. PROTECT X2 contains agents used for a protective covering of the skin from frequent hand washing or use of alcohol-based disinfectants. These unique components are also thought to be effective to treat skin roughness of the dorsa of the hands and heels. In the present study, we evaluated the effectiveness of PROTECT X2 to increase skin surface hydration state, as well as enhance the barrier function of the stratum corneum of the dorsa of the hands and heels in elderly individuals. A total of 8 elderly subjects and their caretakers without any skin diseases participated in the study. They applied PROTECT X2 by themselves to the dorsum area of 1 hand and heel 3 to 5 times daily for 1 month, while the opposite sides were left untreated. We measured stratum corneum (SC) hydration and transepidermal water loss (TEWL) before beginning treatment, then 1 week and 1 month after the start of treatment to compare between the treated and untreated skin. SC hydration state after applications of PROTECT X2 was 1.5- to 3.0-fold higher than that of the untreated skin in the dorsa of both hands and heels, indicating that the moisturizing ingredients accompanied by water were replenished in those areas where the cream was applied. Also, TEWL in the dorsum of the hands was 17.0-27.9% lower on the treated side, indicating improvement in SC barrier function. On the basis of these findings, we concluded that PROTECT X2 enhances water-holding in the SC and aids the barrier function of the skin in the dorsum of the hands. In addition, we consider that this formulation is useful for not only protecting the hands from the effects of such agents as detergents and alcohol-based disinfectants, but also for protecting heel skin covered by a thick SC from dry and cold conditions such as those encountered in winter. However, since the SC in that area is much thicker than that of the hands, the barrier function was not significantly improved within 1 month of daily treatments.

Tight junctions and IBS--the link between epithelial permeability, low-grade inflammation, and symptom generation?

PubMed

Piche, T

2014-03-01

In this issue of Neurogastroenterology and Motility, Dr Ewa Wilcz-Villega and colleagues report low expression of E-cadherin, a tight junction protein involved in the regulation of paracellular permeability, in the colonic mucosa of patients with the irritable bowel syndrome (IBS) with predominance of diarrhea (IBS-D) or alternating symptoms (IBS-A). These findings constitute an improvement in our knowledge of epithelial barrier disruption associated with IBS. There is mounting evidence to indicate that a compromised epithelial barrier is associated with low-grade immune activation and intestinal dysfunction in at least a proportion of IBS patients. During the last 10 years of research, much interest has focused on the increase in the number of different types of immune cells in the gut mucosa of IBS patients including: mast cells, T lymphocytes, and other local cells such as enteroendocrine cells. The inflammatory mediators released by these cells or other luminal factors could be at the origin of altered epithelial barrier functions and enteric nervous system signaling, which lead to gut hypersensitivity. A current conceptual framework states that clinical symptoms of IBS could be associated with structural and functional abnormalities of the mucosal barrier, highlighting the crucial importance of elucidating the contributory role of epithelial barrier defects in the pathogenesis of IBS. More importantly, disruption of the epithelial barrier could also participate in the generation of persistent abdominal pain and discomfort mimicking IBS in patients with inflammatory bowel diseases considered in remission. This mini review gives a brief summary of clinical and experimental evidence concerning the mechanisms underlying epithelial barrier defects in IBS. © 2014 John Wiley & Sons Ltd.

Plasmadiafiltration ameliorating gut mucosal barrier dysfunction and improving survival in porcine sepsis models.

PubMed

Li, Ming Xin; Liu, Jun Feng; Lu, Jian Da; Zhu, Ying; Kuang, Ding Wei; Xiang, Jian Bing; Sun, Peng; Wang, Wei; Xue, Jun; Gu, Yong; Hao, Chuan Ming

2016-12-01

The object of this study is to explore whether the plasmadiafiltration (PDF) is more effective in improving the intestinal mucosal barrier function by removing more key large molecular inflammatory mediators and then prolonging the survival time. Totally, 24 porcine sepsis models induced by cecal ligation and puncture (CLP) operation were randomly divided into three groups: PDF group, high-volume hemofiltration (HVHF) group, and control group, and received 8 h treatment, respectively. The expression of ZO-1 and occludin in intestinal mucosal epithelial cells were detected by immunohistochemistry, and apoptotic protein caspase-3-positive lymphocytes were signed in mesenteric lymph nodes by TUNEL staining. The hemodynamic parameters were measured by invasive cavity detection. The tumor necrosis factor alpha (TNFα) and high-mobility group protein 1 (HMGB1) were tested by ELISA method. And then, the survival curves with all-cause death were compared with three groups. PDF led to a superior reversal of sepsis-related hemodynamic impairment and serum biochemistry abnormalities and resulted in longer survival time compared with HVHF and control (p < 0.01). Definitive protection from excessive TNF-α and HMGB1 response were only achieved by PDF. A more regular distribution pattern of ZO-1 and occludin along the epithelium was found in PDF animals (p < 0.01). The presence of apoptotic lymphocytes was significantly reduced in the PDF animals (p < 0.01). PDF can effectively eliminate more pivotal inflammatory mediators of TNFα and HMGB1 and reduce the inflammation damage of the intestinal mucosal barrier and apoptosis of lymphocyte then improve the circulation function and prolong the survival time.

G3X-K theory: A composite theoretical method for thermochemical kinetics

NASA Astrophysics Data System (ADS)

da Silva, Gabriel

2013-02-01

A composite theoretical method for accurate thermochemical kinetics, G3X-K, is described. This method is accurate to around 0.5 kcal mol-1 for barrier heights and 0.8 kcal mol-1 for enthalpies of formation. G3X-K is a modification of G3SX theory using the M06-2X density functional for structures and zero-point energies and parameterized for a test set of 223 heats of formation and 23 barrier heights. A reduced perturbation-order variant, G3X(MP3)-K, is also developed, providing around 0.7 kcal mol-1 accuracy for barrier heights and 0.9 kcal mol-1 accuracy for enthalpies, at reduced computational cost. Some opportunities to further improve Gn composite methods are identified and briefly discussed.

Three-dimensional biomimetic vascular model reveals a RhoA, Rac1, and N-cadherin balance in mural cell-endothelial cell-regulated barrier function.

PubMed

Alimperti, Stella; Mirabella, Teodelinda; Bajaj, Varnica; Polacheck, William; Pirone, Dana M; Duffield, Jeremy; Eyckmans, Jeroen; Assoian, Richard K; Chen, Christopher S

2017-08-15

The integrity of the endothelial barrier between circulating blood and tissue is important for blood vessel function and, ultimately, for organ homeostasis. Here, we developed a vessel-on-a-chip with perfused endothelialized channels lined with human bone marrow stromal cells, which adopt a mural cell-like phenotype that recapitulates barrier function of the vasculature. In this model, barrier function is compromised upon exposure to inflammatory factors such as LPS, thrombin, and TNFα, as has been observed in vivo. Interestingly, we observed a rapid physical withdrawal of mural cells from the endothelium that was accompanied by an inhibition of endogenous Rac1 activity and increase in RhoA activity in the mural cells themselves upon inflammation. Using a system to chemically induce activity in exogenously expressed Rac1 or RhoA within minutes of stimulation, we demonstrated RhoA activation induced loss of mural cell coverage on the endothelium and reduced endothelial barrier function, and this effect was abrogated when Rac1 was simultaneously activated. We further showed that N -cadherin expression in mural cells plays a key role in barrier function, as CRISPR-mediated knockout of N -cadherin in the mural cells led to loss of barrier function, and overexpression of N -cadherin in CHO cells promoted barrier function. In summary, this bicellular model demonstrates the continuous and rapid modulation of adhesive interactions between endothelial and mural cells and its impact on vascular barrier function and highlights an in vitro platform to study the biology of perivascular-endothelial interactions.

Dietary glucosylceramide enhances tight junction function in skin epidermis via induction of claudin-1.

PubMed

Kawada, Chinatsu; Hasegawa, Tatsuya; Watanabe, Mutsuto; Nomura, Yoshihiro

2013-01-01

Dietary glucosylceramide increased the expression of claudin-1 in UVB-irradiated mouse epidermis. Sphingosine and phytosphingosine, metabolites of glucosylceramide, increased trans-epithelial electrical resistance, and phytosphingosine increased claudin-1 mRNA expression in cultured keratinocytes. Our results indicate that the skin barrier improvement induced by dietary glucosylceramide might be due to enhancement of tight junction function, mediated by increased expression of claudin-1 induced by sphingoid metabolites.

Fluoxetine and vitamin C synergistically inhibits blood-spinal cord barrier disruption and improves functional recovery after spinal cord injury.

PubMed

Lee, Jee Y; Choi, Hae Y; Yune, Tae Y

2016-10-01

Recently we reported that fluoxetine (10 mg/kg) improves functional recovery by attenuating blood spinal cord barrier (BSCB) disruption after spinal cord injury (SCI). Here we investigated whether a low-dose of fluoxetine (1 mg/kg) and vitamin C (100 mg/kg), separately not possessing any protective effect, prevents BSCB disruption and improves functional recovery when combined. After a moderate contusion injury at T9 in rat, a low-dose of fluoxetine and vitamin C, or the combination of both was administered intraperitoneally immediately after SCI and further treated once a day for 14 d. Co-treatment with fluoxetine and vitamin C significantly attenuated BSCB permeability at 1 d after SCI. When only fluoxetine or vitamin C was treated after injury, however, there was no effect on BSCB disruption. Co-treatment with fluoxetine and vitamin C also significantly inhibited the expression and activation of MMP-9 at 8 h and 1 d after injury, respectively, and the infiltration of neutrophils (at 1 d) and macrophages (at 5 d) and the expression of inflammatory mediators (at 2 h, 6 h, 8 h or 24 h after injury) were significantly inhibited by co-treatment with fluoxetine and vitamin C. Furthermore, the combination of fluoxetine and vitamin C attenuated apoptotic cell death at 1 d and 5 d and improved locomotor function at 5 weeks after SCI. These results demonstrate the synergistic effect combination of low-dose fluoxetine and vitamin C on BSCB disruption after SCI and furthermore support the effectiveness of the combination treatment regimen for the management of acute SCI. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimizing Barrier Removal to Restore Connectivity in Utah's Weber Basin

NASA Astrophysics Data System (ADS)

Kraft, M.; Null, S. E.

2016-12-01

Instream barriers, such as dams, culverts and diversions are economically important for water supply, but negatively affect river ecosystems and disrupt hydrologic processes. Removal of uneconomical and aging in-stream barriers to improve habitat connectivity is increasingly used to restore river connectivity. Most past barrier removal projects focused on individual barriers using a score-and-rank technique, ignoring cumulative change from multiple, spatially-connected barrier removals. Similarly, most water supply models optimize either human water use or aquatic connectivity, failing to holistically represent human and environmental benefits. In this study, a dual objective optimization model identified in-stream barriers that impede aquatic habitat connectivity for trout, using streamflow, temperature, and channel gradient as indicators of aquatic habitat suitability. Water scarcity costs are minimized using agricultural and urban economic penalty functions to incorporate water supply benefits and a budget monetizes costs of removing small barriers like culverts and road crossings. The optimization model developed is applied to a case study in Utah's Weber basin to prioritize removal of the most environmentally harmful barriers, while maintaining human water uses. The dual objective solution basis was developed to quantify and graphically visualize tradeoffs between connected quality-weighted habitat for Bonneville cutthroat trout and economic water uses. Modeled results include a spectrum of barrier removal alternatives based on budget and quality-weighted reconnected habitat that can be communicated with local stakeholders. This research will help prioritize barrier removals and future restoration decisions. The modeling approach expands current barrier removal optimization methods by explicitly including economic and environmental water uses.

A Numerical Comparison of Barrier and Modified Barrier Methods for Large-Scale Bound-Constrained Optimization

NASA Technical Reports Server (NTRS)

Nash, Stephen G.; Polyak, R.; Sofer, Ariela

1994-01-01

When a classical barrier method is applied to the solution of a nonlinear programming problem with inequality constraints, the Hessian matrix of the barrier function becomes increasingly ill-conditioned as the solution is approached. As a result, it may be desirable to consider alternative numerical algorithms. We compare the performance of two methods motivated by barrier functions. The first is a stabilized form of the classical barrier method, where a numerically stable approximation to the Newton direction is used when the barrier parameter is small. The second is a modified barrier method where a barrier function is applied to a shifted form of the problem, and the resulting barrier terms are scaled by estimates of the optimal Lagrange multipliers. The condition number of the Hessian matrix of the resulting modified barrier function remains bounded as the solution to the constrained optimization problem is approached. Both of these techniques can be used in the context of a truncated-Newton method, and hence can be applied to large problems, as well as on parallel computers. In this paper, both techniques are applied to problems with bound constraints and we compare their practical behavior.

Neuroimmune Axes of the Blood–Brain Barriers and Blood–Brain Interfaces: Bases for Physiological Regulation, Disease States, and Pharmacological Interventions

PubMed Central

Erickson, Michelle A.

2018-01-01

Central nervous system (CNS) barriers predominantly mediate the immune-privileged status of the brain, and are also important regulators of neuroimmune communication. It is increasingly appreciated that communication between the brain and immune system contributes to physiologic processes, adaptive responses, and disease states. In this review, we discuss the highly specialized features of brain barriers that regulate neuroimmune communication in health and disease. In section I, we discuss the concept of immune privilege, provide working definitions of brain barriers, and outline the historical work that contributed to the understanding of CNS barrier functions. In section II, we discuss the unique anatomic, cellular, and molecular characteristics of the vascular blood–brain barrier (BBB), blood–cerebrospinal fluid barrier, and tanycytic barriers that confer their functions as neuroimmune interfaces. In section III, we consider BBB-mediated neuroimmune functions and interactions categorized as five neuroimmune axes: disruption, responses to immune stimuli, uptake and transport of immunoactive substances, immune cell trafficking, and secretions of immunoactive substances. In section IV, we discuss neuroimmune functions of CNS barriers in physiologic and disease states, as well as pharmacological interventions for CNS diseases. Throughout this review, we highlight many recent advances that have contributed to the modern understanding of CNS barriers and their interface functions. PMID:29496890

[Recent studies on corneal epithelial barrier function].

PubMed

Liu, F F; Li, W; Liu, Z G; Chen, W S

2016-08-01

Corneal epithelium, the outermost layer of eyeball, is the main route for foreign materials to enter the eye. Under physiological conditions, the corneal epithelial superficial cells form a functionally selective permeability barrier. Integral corneal epithelial barrier function not only ensures the enrolling of nutrients which is required for regular metabolism, but also prevents foreign bodies, or disease-causing microorganism invasion. Recently, a large number of clinical and experimental studies have shown that abnormal corneal epithelial barrier function is the pathological basis for many ocular diseases. In addition, some study found that corneal epithelial barrier constitutes a variety of proteins involved in cell proliferation, differentiation, apoptosis, and a series of physiological and pathological processes. This paper reviewed recent studies specifically on the corneal epithelial barrier, highlights of its structure, function and influence factors. (Chin J Ophthalmol, 2016, 52: 631-635).

Recommendations for Constructing Roadside Vegetation Barriers to Improve Near-Road Air Quality

EPA Pesticide Factsheets

The EPA report, Recommendations for Constructing Roadside Vegetation Barriers to Improve Near-Road Air Quality, summarizes the research findings on the best practices for building roadside vegetative barriers to improve air quality. This fact sheet describ

Curcumin improves intestinal barrier function: modulation of intracellular signaling, and organization of tight junctions.

PubMed

Wang, Jing; Ghosh, Siddhartha S; Ghosh, Shobha

2017-04-01

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as type 2 diabetes and atherosclerosis) has shifted the focus from high-fat high-cholesterol containing Western-type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products (e.g., LPS) into circulation due to intestinal barrier dysfunction as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that oral supplementation with curcumin attenuates WD-induced development of type 2 diabetes and atherosclerosis. Poor bioavailability of curcumin has precluded the establishment of a causal relationship between oral supplementation and it is in vivo effects. We hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the intestinal barrier function. The objective of the present study was to delineate the underlying mechanisms. The human IEC lines Caco-2 and HT-29 were used for these studies and modulation of direct as well as indirect effects of LPS on intracellular signaling as well as tight junctions were examined. Pretreatment with curcumin significantly attenuated LPS-induced secretion of master cytokine IL-1β from IECs and macrophages. Furthermore, curcumin also reduced IL-1β-induced activation of p38 MAPK in IECs and subsequent increase in expression of myosin light chain kinase involved in the phosphorylation of tight junction proteins and ensuing disruption of their normal arrangement. The major site of action of curcumin is, therefore, likely the IECs and the intestinal barrier, and by reducing intestinal barrier dysfunction, curcumin modulates chronic inflammatory diseases despite poor bioavailability. Copyright © 2017 the American Physiological Society.

Supporting decision-making for improving longitudinal connectivity for diadromous and potamodromous fishes in complex catchments.

PubMed

Brevé, Niels W P; Buijse, Anthonie D; Kroes, Martin J; Wanningen, Herman; Vriese, Frederik T

2014-10-15

Preservation and restoration of Europe's endangered migratory fish species and habitats are high on the international river basin policy agenda. Improvement through restoration of longitudinal connectivity is seen as an important measure, but although prioritization of in-stream barriers has been addressed at local and regional levels the process still lacks adequate priority on the international level. This paper introduces a well-tested method, designed to help decision makers achieve the rehabilitation of targeted ichthyofauna more successfully. This method assesses artificial barriers within waters designated under the Water Framework Directive (WFD), Europe's main legislative driver for ecological improvement of river basins. The method aggregates migratory fish communities (both diadromous and potamodromous) into functional biological units (ecological fish guilds) and defines their most pressing habitat requirements. Using GIS mapping and spatial analysis of the potential ranges (fish zonation) we pin-point the most important barriers, per guild. This method was developed and deployed over a 12 year period as a practical case study, fitting data derived from the 36 regional water management organisations in the Netherlands. We delivered national advice on the prioritization of a total of 2924 barriers located within WFD water bodies, facilitating migration for all 18 indigenous migratory fish species. Scaling up to larger geographical areas can be achieved using datasets from other countries to link water body typologies to distribution ranges of migratory fish species. Copyright © 2014 Elsevier B.V. All rights reserved.

Integrating ergonomics into production system development--the Volvo Powertrain case.

PubMed

Neumann, W Patrick; Ekman, Marianne; Winkel, Jørgen

2009-05-01

Understanding the barriers and assists to integrating ergonomics into production system design remains a research issue. An action research case study at Volvo Powertrain/Sweden was conducted. Researchers worked collaboratively with the firm in efforts to improve the company's ability to handle ergonomics in their daily work of improving and developing production systems. Researchers observed and reflected collectively on the change process using field notes and recordings to support their observations. Observed integration barriers included both individual level issues like life events, and organisational aspects such as communication barriers between groups or assignment of tasks to people not involved in decision-making. Observed assists included the 'political reflective navigation' (c.f. Broberg, O., Hermund, I., 2004. The OHS consultant as a 'political reflective navigator' in technological change processes. International Journal of Industrial Ergonomics 33 (4), 315-326) by the project owner to find new ways to overcome barriers and anchor ergonomics into the organisation. While special 'ergonomics' groups did not survive long, progress was observed in including ergonomics in regular design groups. A cross-functional workshop that fostered discussion across organisational boundaries helped shift focus from retrofitting systems to future production systems and improve engagement of engineering teams. Progress was marked by both success and setbacks and full integration appears to require more than 2 years time. It is concluded that support by senior managers should include succession planning for personnel that are key to the change effort.

Counselling low-back-pain patients in secondary healthcare: a randomised trial addressing experienced workplace barriers and physical activity.

PubMed

Jensen, Lone Donbæk; Maribo, Thomas; Schiøttz-Christensen, Berit; Madsen, Finn Hjorth; Gonge, Bigitte; Christensen, Michael; Frost, Poul

2012-01-01

To assess if counselling by an occupational physician (OP) addressing experienced workplace barriers and physical activity integrated as a part of low-back pain (LBP) outpatient treatment influences pain, function and sick leave. Randomised controlled trial in the secondary healthcare sector with 3 months' follow-up. The participants were LBP patients who, independently of sick-leave status, expressed concerns about the ability to maintain their current job. Patients referred for surgery were excluded. The intervention consisted of two counselling sessions conducted by an OP addressing both workplace barriers and leisure-time physical activity. A workplace visit was performed if required. Pain, function and duration of sick leave due to LBP were primary outcomes. A reduction in bodily pain and improvement in physical function both measured by the 36-item short-form health survey questionnaire in favour of the intervention group was found. The change in pain score was found to be clinically relevant. The risk of sick leave for at least 8 weeks due to LBP was significantly reduced in the intervention group. Two secondary outcomes, Fear Avoidance Beliefs about physical activity and maximum oxygen uptake, supported compliance and adherence to the part of the intervention focusing on enhanced physical activity. Two short counselling sessions by an OP combining advice on meeting workplace barriers and enhancing physical activity had a substantial effect on important prognostic factors for LBP patients with moderate to severe symptoms diagnosed in outpatient rheumatological clinics. Current Controlled Trials ISRCTN13071157.

Modified hyperbolic sine model for titanium dioxide-based memristive thin films

NASA Astrophysics Data System (ADS)

Abu Bakar, Raudah; Syahirah Kamarozaman, Nur; Fazlida Hanim Abdullah, Wan; Herman, Sukreen Hana

2018-03-01

Since the emergence of memristor as the newest fundamental circuit elements, studies on memristor modeling have been evolved. To date, the developed models were based on the linear model, linear ionic drift model using different window functions, tunnelling barrier model and hyperbolic-sine function based model. Although using hyperbolic-sine function model could predict the memristor electrical properties, the model was not well fitted to the experimental data. In order to improve the performance of the hyperbolic-sine function model, the state variable equation was modified. On the one hand, the addition of window function cannot provide an improved fitting. By multiplying the Yakopcic’s state variable model to Chang’s model on the other hand resulted in the closer agreement with the TiO2 thin film experimental data. The percentage error was approximately 2.15%.

Effect of seasonal and geographical differences on skin and effect of treatment with an osmoprotectant: Sorbitol.

PubMed

Muizzuddin, Neelam; Ingrassia, Michael; Marenus, Kenneth D; Maes, Daniel H; Mammone, Thomas

2013-01-01

Human skin maintains an optimal permeability barrier function in a terrestrial environment that varies considerably in humidity. Cells cultured under hyperosmotic stress accumulate osmolytes including sorbitol. Epidermal keratinocytes experience similar high osmolality under dry environmental conditions because of increased transepidermal water loss (TEWL) and concomitant drying of the skin. This study was designed to determine if epidermal keratinocytes, in vitro, could be protected from high osmotic stress, with the exogenous addition of sorbitol. In addition, we evaluated the effect of a formulation containing topical sorbitol on skin barrier and moisturization of subjects living in arid and humid regions in summer as well as in winter. Results from in vitro experiments showed that 50 mM sorbitol protected epidermal keratinocytes from osmotic toxicity induced by sodium chloride. Clinical studies indicated that skin chronically exposed to hot, dry environment appeared to exhibit stronger skin barrier and a lower baseline TEWL. In addition, skin barrier was stronger in summer than in winter. Sorbitol exhibited significant improvement in both barrier repair and moisturization, especially in individuals subjected to arid environmental conditions.

Effect of ecological immune-enhanced enteral nutrition on patients with gastrointestinal fistulas.

PubMed

Wang, Q-H

2017-05-01

The aim of this study was to determine the effects of early ecological immune-enhanced enteral nutrition on the nutritional status, immune function and intestinal mucosal barrier in patients with gastrointestinal fistulas. 54 patients with gastrointestinal fistulas were randomized to either the ecological immune-enhanced enteral nutrition group (EIEN group, 28) or the parenteral nutrition group (PN group, 26). The changes in the immunity, nutrition index and intestinal mucosal barrier indexes before the ecological immune-enhanced enteral nutrition support and at 7 days and 14 days after the ecological immune-enhanced enteral nutrition support were determined. Compared with the PN group, the indexes of the CD3 and CD4 positive cells, the CD4/CD8 values and the plasma levels of IgA and IgM were significantly higher than those in EIEN group (p<0.05). Moreover, with EIEN nutritional support, the nutrition indexes, such as the plasma ALB, PA and TFN, and the intestinal mucosal barrier index (the plasma D-lactate levels and endotoxin levels), also recovered gradually to normal levels and were higher than those of the PN group (p<0.05). For patients with gastrointestinal fistulas, ecological immune-enhanced enteral nutrition can not only improve the cellular immunity function, humoral immunity, and nutritional status but also enhance the intestinal mucosal barrier.

Contributions of Health Care Coalitions to Preparedness and Resilience: Perspectives From Hospital Preparedness Program and Health Care Preparedness Coalitions.

PubMed

Acosta, Joie; Howard, Stefanie; Chandra, Anita; Varda, Danielle; Sprong, Sara; Uscher-Pines, Lori

2015-12-01

The purpose of this article was to describe how the Hospital Preparedness Program (HPP) and other health care coalitions conceptualize and measure progress or success and to identify strategies to improve coalition success and address known barriers to success. We conducted a structured literature review and interviews with key leaders from 22 HPPs and other coalitions. Interview transcripts were analyzed by using constant comparative analysis. Five dimensions of coalition success were identified: strong member participation, diversity of members, positive changes in members' capacity to respond to or recover from disaster, sharing of resources among members, and being perceived as a trendsetter. Common barriers to success were also identified (eg, a lack of funding and staff). To address these barriers, coalitions suggested a range of mitigation strategies (eg, establishing formal memoranda of agreement). Both dimensions of and barriers to coalition success varied by coalition type. Currently, the term health care coalition is a one-size-fits-all term. In reality, this umbrella term describes a variety of different configurations, member bodies, and capabilities. The analysis offered a typology to categorize health care coalitions by primary function during a disaster response. Developing a common typology that could be used to specify capabilities or functions of coalitions may be helpful to advancing their development.

"We're not just sitting on the periphery": a staff perspective of physical activity in older adults with schizophrenia.

PubMed

Leutwyler, Heather; Hubbard, Erin M; Jeste, Dilip V; Vinogradov, Sophia

2013-06-01

Targeted physical activity interventions to improve the poor physical function of older adults with schizophrenia are necessary but currently not available. Given disordered thought processes and institutionalization, it is likely that older adults with schizophrenia have unique barriers and facilitators to physical activity. It is necessary to consider the perspective of the mental health staff about barriers and facilitators to physical activity to design a feasible intervention. To describe the perceptions of mental health staff about barriers and facilitators to engage in physical activities that promote physical function among older adults with schizophrenia. We conducted qualitative interviews with 23 mental health staff that care for older adults with schizophrenia. The data were collected and analyzed with grounded theory methodology. The participants were interested in promoting physical activity with older adults with schizophrenia. Facilitators and barriers to physical activity identified were mental health, role models and rewards, institutional factors, and safety. In order to design successful physical activity interventions for this population, the intervention may need to be a routine part of the mental health treatment program and patients may need incentives to participate. Staff should be educated that physical activity may provide the dual benefit of physical and mental health treatment.

Dietary Milk Sphingomyelin Prevents Disruption of Skin Barrier Function in Hairless Mice after UV-B Irradiation.

PubMed

Oba, Chisato; Morifuji, Masashi; Ichikawa, Satomi; Ito, Kyoko; Kawahata, Keiko; Yamaji, Taketo; Asami, Yukio; Itou, Hiroyuki; Sugawara, Tatsuya

2015-01-01

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm2). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

The Infant Skin Barrier: Can We Preserve, Protect, and Enhance the Barrier?

PubMed Central

Telofski, Lorena S.; Morello, A. Peter; Mack Correa, M. Catherine; Stamatas, Georgios N.

2012-01-01

Infant skin is different from adult in structure, function, and composition. Despite these differences, the skin barrier is competent at birth in healthy, full-term neonates. The primary focus of this paper is on the developing skin barrier in healthy, full-term neonates and infants. Additionally, a brief discussion of the properties of the skin barrier in premature neonates and infants with abnormal skin conditions (i.e., atopic dermatitis and eczema) is included. As infant skin continues to mature through the first years of life, it is important that skin care products (e.g., cleansers and emollients) are formulated appropriately. Ideally, products that are used on infants should not interfere with skin surface pH or perturb the skin barrier. For cleansers, this can be achieved by choosing the right type of surfactant, by blending surfactants, or by blending hydrophobically-modified polymers (HMPs) with surfactants to increase product mildness. Similarly, choosing the right type of oil for emollients is important. Unlike some vegetable oils, mineral oil is more stable and is not subject to oxidation and hydrolysis. Although emollients can improve the skin barrier, more studies are needed to determine the potential long-term benefits of using emollients on healthy, full-term neonates and infants. PMID:22988452

A role for IL-22 in the relationship between intestinal helminths, gut microbiota and mucosal immunity

PubMed Central

Leung, Jacqueline M.; Loke, P’ng

2014-01-01

The intestinal tract is home to nematodes as well as commensal bacteria (microbiota), which have coevolved with the mammalian host. The mucosal immune system must balance between an appropriate response to dangerous pathogens and an inappropriate response to commensal microbiota that may breach the epithelial barrier, in order to maintain intestinal homeostasis. IL-22 has been shown to play a critical role in maintaining barrier homeostasis against intestinal pathogens and commensal bacteria. Here we review the advances in our understanding of the role of IL-22 in helminth infections, as well as in response to commensal and pathogenic bacteria of the intestinal tract. We then consider the relationship between intestinal helminths and gut microbiota and hypothesize that this relationship may explain how helminths may improve symptoms of inflammatory bowel diseases. We propose that by inducing an immune response that includes IL-22, intestinal helminths may enhance the mucosal barrier function of the intestinal epithelium. This may restore the mucosal microbiota populations from dysbiosis associated with colitis and improve intestinal homeostasis. PMID:23178750

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants.

PubMed

Simal-Gándara, J; Sarria-Vidal, M; Koorevaar, A; Rijk, R

2000-08-01

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick oriented PP) into the food stimulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.

A Lagrange multiplier and Hopfield-type barrier function method for the traveling salesman problem.

PubMed

Dang, Chuangyin; Xu, Lei

2002-02-01

A Lagrange multiplier and Hopfield-type barrier function method is proposed for approximating a solution of the traveling salesman problem. The method is derived from applications of Lagrange multipliers and a Hopfield-type barrier function and attempts to produce a solution of high quality by generating a minimum point of a barrier problem for a sequence of descending values of the barrier parameter. For any given value of the barrier parameter, the method searches for a minimum point of the barrier problem in a feasible descent direction, which has a desired property that lower and upper bounds on variables are always satisfied automatically if the step length is a number between zero and one. At each iteration, the feasible descent direction is found by updating Lagrange multipliers with a globally convergent iterative procedure. For any given value of the barrier parameter, the method converges to a stationary point of the barrier problem without any condition on the objective function. Theoretical and numerical results show that the method seems more effective and efficient than the softassign algorithm.

A globally convergent Lagrange and barrier function iterative algorithm for the traveling salesman problem.

PubMed

Dang, C; Xu, L

2001-03-01

In this paper a globally convergent Lagrange and barrier function iterative algorithm is proposed for approximating a solution of the traveling salesman problem. The algorithm employs an entropy-type barrier function to deal with nonnegativity constraints and Lagrange multipliers to handle linear equality constraints, and attempts to produce a solution of high quality by generating a minimum point of a barrier problem for a sequence of descending values of the barrier parameter. For any given value of the barrier parameter, the algorithm searches for a minimum point of the barrier problem in a feasible descent direction, which has a desired property that the nonnegativity constraints are always satisfied automatically if the step length is a number between zero and one. At each iteration the feasible descent direction is found by updating Lagrange multipliers with a globally convergent iterative procedure. For any given value of the barrier parameter, the algorithm converges to a stationary point of the barrier problem without any condition on the objective function. Theoretical and numerical results show that the algorithm seems more effective and efficient than the softassign algorithm.

Importance of triggers and veto-barriers for the implementation of sanitation in informal peri-urban settlements – The case of Cochabamba, Bolivia

PubMed Central

Rauch, Sebastien; Cossio, Claudia; Landaeta, Graciela; McConville, Jennifer

2018-01-01

An estimated 2.4 billion people lack access to improved sanitation which has devastating consequences for human health and the environment. Understanding what constitute sanitation demand is crucial for accelerating the spread of improved sanitation. This study aims to understand the adoption mechanisms for improved sanitation. An informal peri-urban settlement in Cochabamba, Bolivia was selected as a case study to understand adoption patterns. Various qualitative methods of data collection and analysis were employed. The findings showed that pour-flush toilets was the only preferred sanitation alternative at the study site. An adoption framework for waterborne toilets was developed based on diffusion of innovation theory. Factors that influence adoption were identified. Some functioned as triggers and initiated adoption, whereas some factors blocked adoption and constituted veto-barriers. Most factors were connected to the individual household situation and its members, but neighborhood development also affected pour-flush adoption. Based on adoption time the residents were divided into the following adoption groups: first adopters, early majority, late majority, laggards and non-adopters. Each adoption group followed its own adoption route with specific characteristics and respective triggers or veto-barriers. We argue that the strong demand for waterborne toilets in peri-urban areas need to be recognized and the developed framework could be used for customizing sanitation improvement programs for certain target groups. PMID:29617459

Importance of triggers and veto-barriers for the implementation of sanitation in informal peri-urban settlements - The case of Cochabamba, Bolivia.

PubMed

Helgegren, Ida; Rauch, Sebastien; Cossio, Claudia; Landaeta, Graciela; McConville, Jennifer

2018-01-01

An estimated 2.4 billion people lack access to improved sanitation which has devastating consequences for human health and the environment. Understanding what constitute sanitation demand is crucial for accelerating the spread of improved sanitation. This study aims to understand the adoption mechanisms for improved sanitation. An informal peri-urban settlement in Cochabamba, Bolivia was selected as a case study to understand adoption patterns. Various qualitative methods of data collection and analysis were employed. The findings showed that pour-flush toilets was the only preferred sanitation alternative at the study site. An adoption framework for waterborne toilets was developed based on diffusion of innovation theory. Factors that influence adoption were identified. Some functioned as triggers and initiated adoption, whereas some factors blocked adoption and constituted veto-barriers. Most factors were connected to the individual household situation and its members, but neighborhood development also affected pour-flush adoption. Based on adoption time the residents were divided into the following adoption groups: first adopters, early majority, late majority, laggards and non-adopters. Each adoption group followed its own adoption route with specific characteristics and respective triggers or veto-barriers. We argue that the strong demand for waterborne toilets in peri-urban areas need to be recognized and the developed framework could be used for customizing sanitation improvement programs for certain target groups.

Standards for the Protection of Skin Barrier Function.

PubMed

Giménez-Arnau, Ana

2016-01-01

The skin is a vital organ, and through our skin we are in close contact with the entire environment. If we lose our skin we lose our life. The barrier function of the skin is mainly driven by the sophisticated epidermis in close relationship with the dermis. The epidermal epithelium is a mechanically, chemically, biologically and immunologically active barrier submitted to continuous turnover. The barrier function of the skin needs to be protected and restored. Its own physiology allows its recovery, but many times this is not sufficient. This chapter is focused on the standards to restore, treat and prevent barrier function disruption. These standards were developed from a scientific, academic and clinical point of view. There is a lack of standardized administrative recommendations. Still, there is a walk to do that will help to reduce the social and economic burden of diseases characterized by an abnormal skin barrier function. © 2016 S. Karger AG, Basel.

"State of the Art" of technical protection measures in Austria and the effectiveness documented during bedload and debris flow events

NASA Astrophysics Data System (ADS)

Moser, Markus; Mehlhorn, Susanne; Rudolf-Miklau, Florian; Suda, Jürgen

2017-04-01

Since the beginning of systematic torrent control in Austria 130 years ago, barriers are constructed for protection purposes. Until the end of the 1960s, solid barriers were built at the exits of depositional areas to prevent dangerous debris flows from reaching high consequence areas. The development of solid barriers with large slots or slits to regulate sediment transport began with the use of reinforced concrete during the 1970s (Rudolf-Miklau, Suda 2011). In order to dissipate the energy of debris flows debris flow breakers have been designed since the 1980s. By slowing and depositing the surge front of the debris flow, downstream reaches of the stream channel and settlement areas should be exposed to considerably lower dynamic impact. In the past, the technological development of these constructions was only steered by the experiences of the engineering practice while an institutionalized process of standardization comparable to other engineering branches was not existent. In future all structures have to be designed and dimensioned according to the EUROCODE standards. This was the reason to establish an interdisciplinary working group (ON-K 256) at the Austrian Standards Institute (ASI), which has managed to developed comprehensive new technical standards for torrent control engineering, including load models, design, dimensioning and life cycle assessment of torrent control works (technical standard ONR 24800 - series). Extreme torrential events comprise four definable displacement processes floods; fluvial solid transport; hyper-concentrated solid transport (debris floods) and debris flow (stony debris flow or mud-earth flow). As a rule, the design of the torrential barriers has to follow its function (Kettl, 1984). Modern protection concepts in torrent control are scenario-oriented and try to optimize different functions in a chain of protections structures (function chain). More or less the first step for the designing the optimal construction type is the definition of the displacement processes for each torrent section. The criteria for each process are defined in the technical standard ONR 24800 - series in Austria. According to ONR 24800 the functions of torrential barriers can be divided in process control functional types (retention; dosing and filtering; energy dissipation). The last step is the designing of the construction type. Bedload and debris events in Austria showed the functionality of the barriers. On the basis of these findings and results, some recommendations were derived to improve the function fulfilment of the technical protection measures.

Heavy Cigarette Smokers in a Chinese Population Display a Compromised Permeability Barrier

PubMed Central

Xin, Shujun; Ye, Li; Lv, Chengzhi; Elias, Peter M.

2016-01-01

Cigarette smoking is associated with various cutaneous disorders with defective permeability. Yet, whether cigarette smoking influences epidermal permeability barrier function is largely unknown. Here, we measured skin biophysical properties, including permeability barrier homeostasis, stratum corneum (SC) integrity, SC hydration, skin surface pH, and skin melanin/erythema index, in cigarette smokers. A total of 99 male volunteers were enrolled in this study. Smokers were categorized as light-to-moderate (<20 cigarettes/day) or heavy smokers (≥20 cigarettes/day). An MPA5 was used to measure SC hydration and skin melanin/erythema index on the dorsal hand, forehead, and cheek. Basal transepidermal water loss (TEWL) and barrier recovery rates were assessed on the forearm. A Skin-pH-Meter pH900 was used to measure skin surface pH. Our results showed that heavy cigarette smokers exhibited delayed barrier recovery after acute abrogation (1.02% ± 13.06 versus 16.48% ± 6.07), and barrier recovery rates correlated negatively with the number of daily cigarettes consumption (p = 0.0087). Changes in biophysical parameters in cigarette smokers varied with body sites. In conclusion, heavy cigarette smokers display compromised permeability barrier homeostasis, which could contribute, in part, to the increased prevalence of certain cutaneous disorders characterized by defective permeability. Thus, improving epidermal permeability barrier should be considered for heavy cigarette smokers. PMID:27437403

850nm light-emitting-diode phototherapy plus low-dose tacrolimus (FK-506) as combination therapy in the treatment of Dermatophagoides farinae-induced atopic dermatitis-like skin lesions in NC/Nga mice.

PubMed

Kim, Chang-Hyun; Cheong, Kyung Ah; Lee, Ai-Young

2013-11-01

Light emitting diode (LED) phototherapy is an effective alternative for the treatment of inflammatory skin disorders. Tacrolimus (FK-506) is a potent immunomodulating agent, which has been used to treat AD. Combination therapy is often used in the treatment of AD to improve therapeutic efficacy or to reduce the dose of each drug. To investigate the therapeutic efficacy of monotherapy with either 850nm LED phototherapy or low-dose FK-506, and combination therapy in Dermatophagoides farina (Df)-induced AD-like skin lesions in NC/Nga mice. The Df-induced NC/Nga mice with a clinical score of 7 were used for treatment with LED (10 and 25J/cm(2)) alone, low-dose FK-506 (1mg/kg) or in combination. The synergistic effects of combined therapy were evaluated by dermatitis scores, skin histology, skin barrier function, and immunological parameters, such as IgE, NO, Th2-mediated cytokines and chemokines. Combination therapy with 850nm (25J/cm(2)) LED and low-dose FK-506 showed a significant reduction in the severity of skin lesions. Combined therapy decreased in the serum level of IgE, NO, and in the splenic level of Th2-mediated cytokines and chemokines. Combination therapy significantly also reduced the inflammatory cellular infiltrate into the skin lesions. Moreover, combination therapy led to recovery of skin barrier function in the skin lesions. The use of combination of LED phototherapy and low-dose immunosuppressant improved Df-induced AD-like skin lesions in an NC/Nga mouse model by dominantly reducing IgE, NO, suppressing Th2-mediated immune responses, and inhibiting inflammatory cells, as well as improving skin barrier function. Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Behavior-Specific Influences for Physical Activity Among African American Women.

PubMed

Jackson, Hope; Yates, Bernice C; Blanchard, Shirley; Zimmerman, Lani M; Hudson, Diane; Pozehl, Bunny

2016-08-01

The purpose of this study was to describe physical activity (PA) behaviors and physical functioning of prehypertensive and Stage I hypertensive African American Women (AAW) and to examine the relationships between PA behavior, physical functioning, personal factors, and behavior-specific influences. Pender's Health Promotion Model was the conceptual framework for the study. A cross-sectional design and convenience sample were used. The PA domain where the greatest amount of time was spent was in work-related activity, followed by household, leisure time, and transportation activity. Personal factors most strongly correlated to lower PA were greater body mass index and waist circumference. AAW perceived moderate barriers to PA and minimal family and friend social support for PA. Future interventions need to focus on removing barriers to and improving social support for PA among AAW. © The Author(s) 2016.

Insulation Resistance Degradation in Ni-BaTiO3 Multilayer Ceramic Capacitors

NASA Technical Reports Server (NTRS)

Liu, Donhang (David)

2015-01-01

Insulation resistance (IR) degradation in Ni-BaTiO3 multilayer ceramic capacitors has been characterized by the measurement of both time to failure and direct-current (DC) leakage current as a function of stress time under highly accelerated life test conditions. The measured leakage current-time dependence data fit well to an exponential form, and a characteristic growth time ?SD can be determined. A greater value of tau(sub SD) represents a slower IR degradation process. Oxygen vacancy migration and localization at the grain boundary region results in the reduction of the Schottky barrier height and has been found to be the main reason for IR degradation in Ni-BaTiO3 capacitors. The reduction of barrier height as a function of time follows an exponential relation of phi (??)=phi (0)e(exp -2?t), where the degradation rate constant ??=??o??(????/????) is inversely proportional to the mean time to failure (MTTF) and can be determined using an Arrhenius plot. For oxygen vacancy electromigration, a lower barrier height phi(0) will favor a slow IR degradation process, but a lower phi(0) will also promote electronic carrier conduction across the barrier and decrease the insulation resistance. As a result, a moderate barrier height phi(0) (and therefore a moderate IR value) with a longer MTTF (smaller degradation rate constant ??) will result in a minimized IR degradation process and the most improved reliability in Ni-BaTiO3 multilayer ceramic capacitors.

Insulation Resistance Degradation in Ni-BaTiO3 Multilayer Ceramic Capacitors

NASA Technical Reports Server (NTRS)

Liu, Donhang David

2015-01-01

Insulation resistance (IR) degradation in NiBaTiO3 multilayer ceramic capacitors has been characterized by the measurement of both time to failure (TTF) and direct current leakage current as a function of stress time under highly accelerated life test conditions. The measured leakage current time dependence data fit well to an exponential form, and a characteristic growth time tau (sub SD) can be determined. A greater value of tau (sub SD) represents a slower IR degradation process. Oxygen vacancy migration and localization at the grain boundary region results in the reduction of the Schottky barrier height and has been found to be the main reason for IR degradation in NiBaTiO3 capacitors. The reduction of barrier height as a function oftime follows an exponential relation of phi (t ) = phi (0) e (exp -2Kt), where 13 the degradation rate constant K Koe (Ek/kT) is inversely proportional to the mean TTF (MTTF) and can be determined using an Arrhenius plot. For oxygen vacancy electromigration, a lower barrier height phi (0) will favor a slow IR degradation process, but a lower phi (0) will also promote electronic carrier conduction across the barrier and decrease the IR. As a result, a moderate barrier height phi (0) (and therefore a moderate IR value) with a longer MTTF (smaller degradation rate constant K) will result in a minimized IR degradation process and the most improved reliability in NiBaTiO3 multilayer ceramic capacitors.

A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.

PubMed

Desai, Mahesh S; Seekatz, Anna M; Koropatkin, Nicole M; Kamada, Nobuhiko; Hickey, Christina A; Wolter, Mathis; Pudlo, Nicholas A; Kitamoto, Sho; Terrapon, Nicolas; Muller, Arnaud; Young, Vincent B; Henrissat, Bernard; Wilmes, Paul; Stappenbeck, Thaddeus S; Núñez, Gabriel; Martens, Eric C

2016-11-17

Despite the accepted health benefits of consuming dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic mouse model, in which animals were colonized with a synthetic human gut microbiota composed of fully sequenced commensal bacteria, we elucidated the functional interactions between dietary fiber, the gut microbiota, and the colonic mucus barrier, which serves as a primary defense against enteric pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium. Our work reveals intricate pathways linking diet, the gut microbiome, and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

Facilitators and Barriers to Performing Activities and Participation in Children With Cerebral Palsy: Caregivers' Perspective.

PubMed

Earde, Pinailug Tantilipikorn; Praipruk, Aina; Rodpradit, Phanlerd; Seanjumla, Parichad

2018-01-01

To investigate contextual factors that were facilitators and barriers to performing activity and participation for children with cerebral palsy from the caregivers' perspective. Qualitative in-depth interview with primary caregivers of children with cerebral palsy aged 4 to 12 years was conducted in the metropolitan area of Thailand. Semistructured questions related to environmental and personal factors were recorded. Interviews were transcribed verbatim and analyzed for main themes on the basis of the International Classification of Functioning, Disability, and Health-Children and Youth Version (ICF-CY) classification. Twenty-seven caregivers participated. Facilitators were appropriateness of assistive devices, support and acceptance from family, friends, and society, health services, willingness, and self-acceptance. Barriers were inappropriate design and facilities, overprotection of family, nonacceptance from family, friends, and society, inconvenient transportation, financial problems, limited health services, limited access to education, frustration, and being an introvert. Contextual factors that can be facilitators and barriers to perform activities and participation should be considered for improving lives of children with cerebral palsy.

Arctigenin from Fructus Arctii (Seed of Burdock) Reinforces Intestinal Barrier Function in Caco-2 Cell Monolayers

PubMed Central

Shin, Hee Soon; Jung, Sun Young; Back, Su Yeon; Do, Jeong-Ryong; Shon, Dong-Hwa

2015-01-01

Fructus Arctii is used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect of F. Arctii extract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component of F. Arctii. We measured transepithelial electrical resistance (TEER) value (as an index of barrier function) and ovalbumin (OVA) permeation (as an index of permeability) to observe the changes of intestinal barrier function. The treatment of F. Arctii increased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component of F. Arctii increased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed that F. Arctii could enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin from F. Arctii could contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function. PMID:26550018

The impact of aging on epithelial barriers.

PubMed

Parrish, Alan R

2017-10-02

The epithelium has many critical roles in homeostasis, including an essential responsibility in establishing tissue barriers. In addition to the fundamental role in separating internal from external environment, epithelial barriers maintain nutrient, fluid, electrolyte and metabolic waste balance in multiple organs. While, by definition, barrier function is conserved, the structure of the epithelium varies across organs. For example, the skin barrier is a squamous layer of cells with distinct structural features, while the lung barrier is composed of a very thin single cell to minimize diffusion space. With the increased focus on age-dependent alterations in organ structure and function, there is an emerging interest in the impact of age on epithelial barriers. This review will focus on the impact of aging on the epithelial barrier of several organs, including the skin, lung, gastrointestinal tract and the kidney, at a structural and functional level.

[Immune dysfunction and cognitive deficit in stress and physiological aging. Part II: New approaches to cognitive disorder prevention and treatment ].

PubMed

Pukhal'skiĭ, A L; Shmarina, G V; Aleshkin, V A

2014-01-01

Long-term stress as well as physiological aging result in similar immunological and hormonal disturbances including hypothalamic-pituitary-adrenal) axis depletion, aberrant immune response (regulatory T-cells, Tregs, and T(h17)-lymphocyte accumulation) and decreased dehydroepian-drosterone synthesis both in the brain and in the adrenal glands. Since the main mechanisms of inflammation control, "prompt" (stress hormones) and "delayed" (Tregs), are broken, serum cytokine levels increase and become sufficient for blood-brain-barrier disruption. As a result peripheral cytokines penetrate into the brain where they begin to perform new functions. Structural and functional alterations of blood-brain-barrier as well as stress- (or age-) induced neuroinflammation promote influx of bone marrow derived dendritic cells and lymphocyte effectors into the brain parenchyma. Thereafter, mass intrusion ofpro-inflammatory mediators and immune cells having a lot of specific targets alters the brain work that we can observe both in humans and in animal experiments. The concept of stressful cognitive dysfunction, which is under consideration in this review, allows picking out several therapeutic targets: 1) reduction of excessive Treg accumulation; 2) supporting hypothalamic-pituitary-adrenal axis and inflammatory reaction attenuation; 3) recovery of dehydroepiandrosterone level; 4) improvement of blood-brain-barrier function.

Long-Term Outcomes of Using Hyaluronic Acid-Carboxymethylcellulose Adhesion Barrier Film on the Neurovascular Bundle.

PubMed

Patel, Rutveej; Modi, Parth K; Elsamra, Sammy E; Kim, Isaac Yi

2016-06-01

We hypothesize that the use of hyaluronic acid-carboxymethylcellulose (HACM) adhesion barrier at the neurovascular bundle may hasten the return of erectile function after robot-assisted laparoscopic prostatectomy. A retrospective review identified 462 consecutive patients who underwent a nerve-sparing prostatectomy between 2009 and 2012. The first 246 patients were administered the barrier film, while the next 216 patients, the control group, did not receive HACM. Postoperative erectile function and oncologic outcomes were compared. Independent t-test and Kaplan-Meier analysis were conducted, p < 0.05 was considered significant. The two groups were well matched, without significant differences in age, weight, operative time, prostate size, preoperative prostate-specific antigen, sexual health inventory for men (SHIM), or AUA symptom scores. The mean SHIM was significantly higher for the experimental group at 6 months (6.39 vs 4.75, p = 0.008), 9 months (7.32 vs 5.44, p = 0.006), 1 year (8.52 vs 6.90, p = 0.049), and 18 months (10.01 vs 7.60, p = 0.018). This effect was not noted beyond 18 months. A subgroup analysis of patients with initial SHIM scores 22 or greater demonstrated a higher rate of return to the preoperative SHIM score for the barrier film group, 23% vs 12% (p = 0.046). There was no significant difference in biochemical recurrence between groups, with a median follow-up duration of 18 months. HACM application at the neurovascular bundle during prostatectomy may decrease the time to return of erectile function, with improved SHIM at 6 to 18 months after surgery. This effect is more pronounced in patients with better baseline erectile function. There is no significant effect on biochemical recurrence.

Advanced technique for long term culture of epithelia in a continuous luminal-basal medium gradient.

PubMed

Schumacher, Karl; Strehl, Raimund; de, Vries Uwe; Minuth, Will W

2002-02-01

The majority of epithelia in our organism perform barrier functions on being exposed to different fluids at the luminal and basal sides. To simulate this natural situation under in vitro conditions for biomaterial testing and tissue engineering the epithelia have to withstand mechanical and fluid stress over a prolonged period of time. Leakage, edge damage and pressure differences in the culture system have to be avoided so that the epithelial barrier function is maintained. Besides, the environmental influences on important cell biological features such as, sealing or transport functions, have to remain upregulated and a loss of characteristics by dedifferentiation is prevented. Our aim is to expose embryonic renal collecting duct (CD) epithelia as model tissue for 14 days to fluid gradients and to monitor the development of tissue-specific features. For these experiments, cultured embryonic epithelia are placed in tissue carriers and in gradient containers, where different media are superfused at the luminal and basal sides. Epithelia growing on the tissue carriers act as a physiological barrier during the whole culture period. To avoid mechanical damage of the tissue and to suppress fluid pressure differences between the luminal and basal compartments improved transport of the medium and an elimination of unilaterally accumulated gas bubbles in the gradient container compartments by newly developed gas expander modules is introduced. By the application of these tools the yield of embryonic renal collecting duct epithelia with intact barrier function on a fragile natural support material could be increased significantly as compared to earlier experiments. Epithelia treated with a luminal NaCl load ranging from 3 to 24 mmol l were analyzed by immunohistochemical methods to determine the degree of differentiation. The tissue showed an upregulation of individual CD cell features as compared to embryonic epithelia in the neonatal kidney.

Management of Patients with Atopic Dermatitis: The Role of Emollient Therapy

PubMed Central

Catherine Mack Correa, M.; Nebus, Judith

2012-01-01

Atopic dermatitis is a common inflammatory skin disorder that afflicts a growing number of young children. Genetic, immune, and environmental factors interact in a complex fashion to contribute to disease expression. The compromised stratum corneum found in atopic dermatitis leads to skin barrier dysfunction, which results in aggravation of symptoms by aeroallergens, microbes, and other insults. Infants—whose immune system and epidermal barrier are still developing—display a higher frequency of atopic dermatitis. Management of patients with atopic dermatitis includes maintaining optimal skin care, avoiding allergic triggers, and routinely using emollients to maintain a hydrated stratum corneum and to improve barrier function. Flares of atopic dermatitis are often managed with courses of topical corticosteroids or calcineurin inhibitors. This paper discusses the role of emollients in the management of atopic dermatitis, with particular emphasis on infants and young children. PMID:23008699

Double-hybrid density-functional theory with meta-generalized-gradient approximations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Souvi, Sidi M. O., E-mail: sidi.souvi@irsn.fr; Sharkas, Kamal; Toulouse, Julien, E-mail: julien.toulouse@upmc.fr

2014-02-28

We extend the previously proposed one-parameter double-hybrid density-functional theory [K. Sharkas, J. Toulouse, and A. Savin, J. Chem. Phys. 134, 064113 (2011)] to meta-generalized-gradient-approximation (meta-GGA) exchange-correlation density functionals. We construct several variants of one-parameter double-hybrid approximations using the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA functional and test them on test sets of atomization energies and reaction barrier heights. The most accurate variant uses the uniform coordinate scaling of the density and of the kinetic energy density in the correlation functional, and improves over both standard Kohn-Sham TPSS and second-order Møller-Plesset calculations.

Using Free Internet Videogames in Upper Extremity Motor Training for Children with Cerebral Palsy.

PubMed

Sevick, Marisa; Eklund, Elizabeth; Mensch, Allison; Foreman, Matthew; Standeven, John; Engsberg, Jack

2016-06-07

Movement therapy is one type of upper extremity intervention for children with cerebral palsy (CP) to improve function. It requires high-intensity, repetitive and task-specific training. Tedium and lack of motivation are substantial barriers to completing the training. An approach to overcome these barriers is to couple the movement therapy with videogames. This investigation: (1) tested the feasibility of delivering a free Internet videogame upper extremity motor intervention to four children with CP (aged 8-17 years) with mild to moderate limitations to upper limb function; and (2) determined the level of intrinsic motivation during the intervention. The intervention used free Internet videogames in conjunction with the Microsoft Kinect motion sensor and the Flexible Action and Articulated Skeleton Toolkit software (FAAST) software. Results indicated that the intervention could be successfully delivered in the laboratory and the home, and pre- and post- impairment, function and performance assessments were possible. Results also indicated a high level of motivation among the participants. It was concluded that the use of inexpensive hardware and software in conjunction with free Internet videogames has the potential to be very motivating in helping to improve the upper extremity abilities of children with CP. Future work should include results from additional participants and from a control group in a randomized controlled trial to establish efficacy.

Homoclinic orbits and critical points of barrier functions

NASA Astrophysics Data System (ADS)

Cannarsa, Piermarco; Cheng, Wei

2015-06-01

We interpret the close link between the critical points of Mather's barrier functions and minimal homoclinic orbits with respect to the Aubry sets on {{T}}n . We also prove a critical point theorem for barrier functions and the existence of such homoclinic orbits on {{T}}2 as an application.

Could tight junctions regulate the barrier function of the aged skin?

PubMed

Svoboda, Marek; Bílková, Zuzana; Muthný, Tomáš

2016-03-01

The skin is known to be the largest organ in human organism creating interface with outer environment. The skin provides protective barrier against pathogens, physical and chemical insults, and against uncontrolled loss of water. The barrier function was primarily attributed to the stratum corneum (SC) but recent studies confirmed that epidermal tight junctions (TJs) also play important role in maintaining barrier properties of the skin. Independent observations indicate that barrier function and its recovery is impaired in aged skin. However, trans-epidermal water loss (TEWL) values remains rather unchanged in elderly population. UV radiation as major factor of photoageing impairs TJ proteins, but TJs have great self-regenerative potential. Since it may be possible that TJs can compensate TEWL in elderly due to its regenerative and compensatory capabilities, important question remains to be answered: how are TJs regulated during skin ageing? This review provides an insight into TJs functioning as epidermal barrier and summarizes current knowledge about the impact of ageing on the barrier function of the skin and epidermal TJs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Prevention and treatment of diaper dermatitis.

PubMed

Blume-Peytavi, Ulrike; Kanti, Varvara

2018-03-01

Diaper dermatitis (DD) is one of the most common skin conditions that infants suffer from and their caregivers manage in the first months post-birth. As such, questions of effective prevention and treatment of the condition often arise. Nonmedical skincare practices that support healthy skin barrier function can prevent DD manifestation or alleviate the condition in many cases. The usage of barrier emollients and improved diaper technology contributes to keeping moisture and irritants away from an infant's delicate skin. This paper addresses facts behind commonly asked questions from caregivers regarding DD and discusses effective measures to prevent and treat the condition. © 2018 Wiley Periodicals, Inc.

Chemical Vapor Deposition of Turbine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Haven, Victor E.

1999-01-01

Ceramic thermal barrier coatings extend the operating temperature range of actively cooled gas turbine components, therefore increasing thermal efficiency. Performance and lifetime of existing ceram ic coatings are limited by spallation during heating and cooling cycles. Spallation of the ceramic is a function of its microstructure, which is determined by the deposition method. This research is investigating metalorganic chemical vapor deposition (MOCVD) of yttria stabilized zirconia to improve performance and reduce costs relative to electron beam physical vapor deposition. Coatings are deposited in an induction-heated, low-pressure reactor at 10 microns per hour. The coating's composition, structure, and response to the turbine environment will be characterized.

Patient specific actual size 3D printed models for patient education in glioma treatment: first experiences.

PubMed

van de Belt, Tom H; Nijmeijer, Hugo; Grim, David; Engelen, Lucien Jlpg; Vreeken, Rinaldo; van Gelder, Marleen Mmj; Laan, Mark Ter

2018-06-02

Cancer patients need high quality information about the disease stage, treatment options and side effects. High quality information can also improve health literacy, shared decision-making and satisfaction. We created patient-specific 3D models of tumours including surrounding functional areas, and assessed what patients with glioma actually value (or fear) about these models when they are used to educate them about the relation between their tumour and specific brain parts, the surgical procedure, and risks. We carried out an explorative study with adult glioma patients, who underwent functional MRI and DTi as part of the pre-operative work-up. All participants received an actual size 3D model, printed based on fMRI and DTi imaging. Semi-structured interviews were held to identify facilitators and barriers for using the model, and perceived effects. A model was successfully created for all 11 participants. A total of 18 facilitators and 8 barriers were identified. The model improved patients' understanding about their situation, that it was easier to ask questions to their neurosurgeon based on their model and that it supported their decision about the preferred treatment. A perceived barrier for using the 3D model was that it could be emotionally confronting, particularly in an early phase of the disease process. Positive effects were related to psychological domains including coping, learning effects and communication. Patient-specific 3D models are promising and simple tools that could help patients with glioma to better understand their situation, treatment options and risks. They have the potential to improve shared decision-making. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

A new body moisturizer increases skin hydration and improves atopic dermatitis symptoms among children and adults.

PubMed

Simpson, Eric; Dutronc, Yves

2011-07-01

Moisturizers result in an increase of skin hydration and restoration of the skin barrier function and play a prominent role in the longterm management of atopic dermatitis (AD). Cetaphil RestoradermTM Moisturizer (CRM) contains novel ingredients specifically designed for AD, and its effects on skin hydration, skin barrier function and signs of AD were assessed in four studies, three of which were evaluator-blinded, randomized and intra-individual comparison trials. A single application of CRM induced significantly greater hydration than the untreated control for at least 24 hours (P is less than 0.001). After the skin was disrupted with 0.5% sodium dodecyl sulfate (SDS), applications of CRM led to a more rapid restoration of skin barrier function and maintained significantly greater skin hydration compared to the untreated control (both P is less than 0.05). After four weeks of twice-daily CRM application among subjects with a history of AD, a significant decrease of itching/stinging scores compared to baseline was reported, as well as an improvement in the quality-of- life and a high level of satisfaction regarding the product. When CRM was used as an adjunctive treatment with topical steroid for four weeks among subjects with mild-to-moderate AD, a more rapid decrease of overall disease severity was observed on days 7, 14 and 21 by the blinded investigator (P is less than 0.05), compared to steroid treatment alone. In summary, CRM is suitable for the specific needs of patients with AD and can be used either alone for long-term management or in adjunction with traditional treatment for both short and long-term disease control.

Synergistic effect of amino acids modified on dendrimer surface in gene delivery.

PubMed

Wang, Fei; Wang, Yitong; Wang, Hui; Shao, Naimin; Chen, Yuanyuan; Cheng, Yiyun

2014-11-01

Design of an efficient gene vector based on dendrimer remains a great challenge due to the presence of multiple barriers in gene delivery. Single-functionalization on dendrimer cannot overcome all the barriers. In this study, we synthesized a list of single-, dual- and triple-functionalized dendrimers with arginine, phenylalanine and histidine for gene delivery using a one-pot approach. The three amino acids play different roles in gene delivery: arginine is essential in formation of stable complexes, phenylalanine improves cellular uptake efficacy, and histidine increases pH-buffering capacity and minimizes cytotoxicity of the cationic dendrimer. A combination of these amino acids on dendrimer generates a synergistic effect in gene delivery. The dual- and triple-functionalized dendrimers show minimal cytotoxicity on the transfected NIH 3T3 cells. Using this combination strategy, we can obtain triple-functionalized dendrimers with comparable transfection efficacy to several commercial transfection reagents. Such a combination strategy should be applicable to the design of efficient and biocompatible gene vectors for gene delivery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hyaluronan-Inorganic Nanohybrid Materials for Biomedical Applications.

PubMed

Cai, Zhixiang; Zhang, Hongbin; Wei, Yue; Cong, Fengsong

2017-06-12

Nanomaterials, including gold, silver, and magnetic nanoparticles, carbon, and mesoporous materials, possess unique physiochemical and biological properties, thus offering promising applications in biomedicine, such as in drug delivery, biosensing, molecular imaging, and therapy. Recent advances in nanotechnology have improved the features and properties of nanomaterials. However, these nanomaterials are potentially cytotoxic and demonstrate a lack of cell-specific function. Thus, they have been functionalized with various polymers, especially polysaccharides, to reduce toxicity and improve biocompatibility and stability under physiological conditions. In particular, nanomaterials have been widely functionalized with hyaluronan (HA) to enhance their distribution in specific cells and tissues. This review highlights the most recent advances on HA-functionalized nanomaterials for biotechnological and biomedical applications, as nanocarriers in drug delivery, contrast agents in molecular imaging, and diagnostic agents in cancer therapy. A critical evaluation of barriers affecting the use of HA-functionalized nanomaterials is also discussed, and insights into the outlook of the field are explored.

The Teen Depression Awareness Project: Building an Evidence Base for Improving Teen Depression Care. Research Highlights

ERIC Educational Resources Information Center

Adamson, David M.

2010-01-01

Depression's effects on adolescent functioning and family burden are not well understood; there is also limited understanding of teens' and parents' attitudes and knowledge about depression, how these and other factors influence readiness for treatment, and the barriers to care that teens and their parents encounter. To address these knowledge…

Pathways to Personal Growth. Developing a Sense of Worth and Competence: A Holistic Education Approach.

ERIC Educational Resources Information Center

Witmer, J. Melvin

This book is intended to motivate persons working in the human and social service occupations toward fuller personal development as well as to improve professional competence. The first part discusses the process of becoming a more fully functioning person. Human potential, barriers to personal growth, self-fulfillment, and seeking pathways to…

"We're Not Just Sitting on the Periphery": A Staff Perspective of Physical Activity in Older Adults with Schizophrenia

ERIC Educational Resources Information Center

Leutwyler, Heather; Hubbard, Erin M.; Jeste, Dilip V.; Vinogradov, Sophia

2013-01-01

Targeted physical activity interventions to improve the poor physical function of older adults with schizophrenia are necessary but currently not available. Given disordered thought processes and institutionalization, it is likely that older adults with schizophrenia have unique barriers and facilitators to physical activity. It is necessary to…

Barriers and Solutions to HE Progression for Early Years' Practitioners

ERIC Educational Resources Information Center

Kendall, Alexandra; Carey, Danielle; Cramp, Andy; Perkins, Helen

2012-01-01

Shifts in UK social and economic policy have focused on education and care in the Early Years as key to improving social inclusion, skills acquisition and longer term social and economic prosperity. The implications for practitioners in the sector have been significant as roles, functions and foci have been renegotiated through the processes of…

Randomised clinical trial: the effects of a multispecies probiotic vs. placebo on innate immune function, bacterial translocation and gut permeability in patients with cirrhosis.

PubMed

Horvath, A; Leber, B; Schmerboeck, B; Tawdrous, M; Zettel, G; Hartl, A; Madl, T; Stryeck, S; Fuchs, D; Lemesch, S; Douschan, P; Krones, E; Spindelboeck, W; Durchschein, F; Rainer, F; Zollner, G; Stauber, R E; Fickert, P; Stiegler, P; Stadlbauer, V

2016-11-01

Probiotics may correct intestinal dysbiosis and proinflammatory conditions in patients with liver cirrhosis. To test the effects of a multispecies probiotic on innate immune function, bacterial translocation and gut permeability. In a randomised, double blind, placebo-controlled study, stable cirrhotic out-patients either received a daily dose of a probiotic powder containing eight different bacterial strains (Ecologic Barrier, Winclove, Amsterdam, The Netherlands) (n = 44) or a placebo (n = 36) for 6 months and were followed up for another 6 months. We found a significant but subclinical increase in neutrophil resting burst (2.6-3.2%, P = 0.0134) and neopterin levels (7.7-8.4 nmol/L, P = 0.001) with probiotics but not with placebo. Probiotic supplementation did not have a significant influence on neutrophil phagocytosis, endotoxin load, gut permeability or inflammatory markers. Ten severe infections occurred in total; one during intervention in the placebo group, and five and four after the intervention has ended in the probiotic and placebo group, respectively. Liver function showed some improvement with probiotics but not with placebo. Probiotic supplementation significantly increased serum neopterin levels and the production of reactive oxygen species by neutrophils. These findings might explain the beneficial effects of probiotics on immune function. Furthermore, probiotic supplementation may be a well-tolerated method to maintain or even improve liver function in stable cirrhosis. However, its influence on gut barrier function and bacterial translocation in cirrhotic patients is minimal. © 2016 The Authors. Alimentary Pharmacology & Therapeutics Published by John Wiley & Sons Ltd.

miR-155 Deletion in Mice Overcomes Neuron-Intrinsic and Neuron-Extrinsic Barriers to Spinal Cord Repair.

PubMed

Gaudet, Andrew D; Mandrekar-Colucci, Shweta; Hall, Jodie C E; Sweet, David R; Schmitt, Philipp J; Xu, Xinyang; Guan, Zhen; Mo, Xiaokui; Guerau-de-Arellano, Mireia; Popovich, Phillip G

2016-08-10

Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers including inflammation. microRNA (miR)-155-5p is a small, noncoding RNA that negatively regulates mRNA translation. In macrophages, miR-155-5p is induced by inflammatory stimuli and elicits a response that could be toxic after SCI. miR-155 may also independently alter expression of genes that regulate axon growth in neurons. Here, we hypothesized that miR-155 deletion would simultaneously improve axon growth and reduce neuroinflammation after SCI by acting on both neurons and macrophages. New data show that miR-155 deletion attenuates inflammatory signaling in macrophages, reduces macrophage-mediated neuron toxicity, and increases macrophage-elicited axon growth by ∼40% relative to control conditions. In addition, miR-155 deletion increases spontaneous axon growth from neurons; adult miR-155 KO dorsal root ganglion (DRG) neurons extend 44% longer neurites than WT neurons. In vivo, miR-155 deletion augments conditioning lesion-induced intraneuronal expression of SPRR1A, a regeneration-associated gene; ∼50% more injured KO DRG neurons expressed SPRR1A versus WT neurons. After dorsal column SCI, miR-155 KO mouse spinal cord has reduced neuroinflammation and increased peripheral conditioning-lesion-enhanced axon regeneration beyond the epicenter. Finally, in a model of spinal contusion injury, miR-155 deletion improves locomotor function at postinjury times corresponding with the arrival and maximal appearance of activated intraspinal macrophages. In miR-155 KO mice, improved locomotor function is associated with smaller contusion lesions and decreased accumulation of inflammatory macrophages. Collectively, these data indicate that miR-155 is a novel therapeutic target capable of simultaneously overcoming neuron-intrinsic and neuron-extrinsic barriers to repair after SCI. Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers, including inflammation. Here, new data show that deleting microRNA-155 (miR-155) affects both mechanisms and improves repair and functional recovery after SCI. Macrophages lacking miR-155 have altered inflammatory capacity, which enhances neuron survival and axon growth of cocultured neurons. In addition, independent of macrophages, adult miR-155 KO neurons show enhanced spontaneous axon growth. Using either spinal cord dorsal column crush or contusion injury models, miR-155 deletion improves indices of repair and recovery. Therefore, miR-155 has a dual role in regulating spinal cord repair and may be a novel therapeutic target for SCI and other CNS pathologies. Copyright © 2016 the authors 0270-6474/16/368516-17$15.00/0.

Pathways and Progress in Improving Drug Delivery through the Intestinal Mucosa and Blood-Brain Barriers

PubMed Central

Laksitorini, Marlyn; Prasasty, Vivitri D.; Kiptoo, Paul K.; Siahaan, Teruna J.

2015-01-01

One of the major hurdles in developing therapeutic agents is the difficulty in delivering drugs through the intestinal mucosa and blood-brain barriers (BBB). The goal here is to describe the general structures of the biological barriers and the strategies to enhance drug delivery across these barriers. Prodrug methods used to improve drug penetration via the transcellular pathway have been successfully developed, and some prodrugs have been used to treat patients. The use of transporters to improve absorption of some drugs (e.g., antiviral agents) has also been successful in treating patients. Other methods, including (a) blocking the efflux pumps to improve transcellular delivery and (b) modulation of cell-cell adhesion in the intercellular junctions to improve paracellular delivery across biological barriers are still in the investigational stage. PMID:25418271

Thermal barrier coating on high temperature industrial gas turbine engines

NASA Technical Reports Server (NTRS)

Carlson, N.; Stoner, B. L.

1977-01-01

The thermal barrier coating used was a yttria stabilized zirconia material with a NiCrAlY undercoat, and the base engine used to establish improvements was the P&WA FT50A-4 industrial gas turbine engine. The design benefits of thermal barrier coatings include simplified cooling schemes and the use of conventional alloys in the engine hot section. Cooling flow reductions and improved heating rates achieved with thermal barrier coating result in improved performance. Economic benefits include reduced power production costs and reduced fuel consumption. Over the 30,000 hour life of the thermal barrier coated parts, fuel savings equivalent to $5 million are projected and specific power (megawatts/mass of engine airflow) improvements on the order of 13% are estimated.

Coffee polyphenols extracted from green coffee beans improve skin properties and microcirculatory function.

PubMed

Fukagawa, Satoko; Haramizu, Satoshi; Sasaoka, Shun; Yasuda, Yuka; Tsujimura, Hisashi; Murase, Takatoshi

2017-09-01

Coffee polyphenols (CPPs), including chlorogenic acid, exert various physiological activities. The purpose of this study was to investigate the effects of CPPs on skin properties and microcirculatory function in humans. In this double-blind, placebo-controlled study, 49 female subjects with mildly xerotic skin received either a test beverage containing CPPs (270 mg/100 mL/day) or a placebo beverage for 8 weeks. The ingestion of CPPs significantly lowered the clinical scores for skin dryness, decreased transepidermal water loss, skin surface pH, and increased stratum corneum hydration and the responsiveness of skin blood flow during local warming. Moreover, the amounts of free fatty acids and lactic acid in the stratum corneum significantly increased after the ingestion of CPPs. These results suggest that an 8-week intake of CPPs improve skin permeability barrier function and hydration, with a concomitant improvement in microcirculatory function, leading to efficacy in the alleviation of mildly xerotic skin.

Symmetry analysis of a model for the exercise of a barrier option

NASA Astrophysics Data System (ADS)

O'Hara, J. G.; Sophocleous, C.; Leach, P. G. L.

2013-09-01

A barrier option takes into account the possibility of an unacceptable change in the price of the underlying stock. Such a change could carry considerable financial loss. We examine one model based upon the Black-Scholes-Merton Equation and determine the functional forms of the barrier function and rebate function which are consistent with a solution of the underlying evolution partial differential equation using the Lie Theory of Extended Groups. The solution is consistent with the possibility of no rebate and the barrier function is very similar to one adopted on an heuristic basis.

Schottky barrier amorphous silicon solar cell with thin doped region adjacent metal Schottky barrier

DOEpatents

Carlson, David E.; Wronski, Christopher R.

1979-01-01

A Schottky barrier amorphous silicon solar cell incorporating a thin highly doped p-type region of hydrogenated amorphous silicon disposed between a Schottky barrier high work function metal and the intrinsic region of hydrogenated amorphous silicon wherein said high work function metal and said thin highly doped p-type region forms a surface barrier junction with the intrinsic amorphous silicon layer. The thickness and concentration of p-type dopants in said p-type region are selected so that said p-type region is fully ionized by the Schottky barrier high work function metal. The thin highly doped p-type region has been found to increase the open circuit voltage and current of the photovoltaic device.

Flexible barrier film, method of forming same, and organic electronic device including same

DOEpatents

Blizzard, John; Tonge, James Steven; Weidner, William Kenneth

2013-03-26

A flexible barrier film has a thickness of from greater than zero to less than 5,000 nanometers and a water vapor transmission rate of no more than 1.times.10.sup.-2 g/m.sup.2/day at 22.degree. C. and 47% relative humidity. The flexible barrier film is formed from a composition, which comprises a multi-functional acrylate. The composition further comprises the reaction product of an alkoxy-functional organometallic compound and an alkoxy-functional organosilicon compound. A method of forming the flexible barrier film includes the steps of disposing the composition on a substrate and curing the composition to form the flexible barrier film. The flexible barrier film may be utilized in organic electronic devices.

War experiences, general functioning and barriers to care among former child soldiers in Northern Uganda: the WAYS study.

PubMed

Amone-P'Olak, Kennedy; Jones, Peter; Meiser-Stedman, Richard; Abbott, Rosemary; Ayella-Ataro, Paul Stephen; Amone, Jackson; Ovuga, Emilio

2014-12-01

Exposure to war is associated with considerable risks for long-term mental health problems (MHP) and poor functioning. Yet little is known about functioning and mental health service (MHS) use among former child soldiers (FCS). We assessed whether different categories of war experiences predict functioning and perceived need for, sources of and barriers to MHS among FCS. Data were drawn from an on-going War-affected Youths (WAYS) cohort study of FCS in Uganda. Participants completed questionnaires about war experiences, functioning and perceived need for, sources of and barriers to MHS. Regression analyses and parametric tests were used to assess between-group differences. Deaths, material losses, threat to loved ones and sexual abuse significantly predicted poor functioning. FCS who received MHS function better than those who did not. Females reported more emotional and behavioural problems and needed MHS more than males. FCS who function poorly indicated more barriers to MHS than those who function well. Stigma, fear of family break-up and lack of health workers were identified as barriers to MHS. Various war experiences affect functioning differently. A significant need for MHS exists amidst barriers to MHS. Nevertheless, FCS are interested in receiving MHS and believe it would benefit them. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potential for the use of mHealth in the management of cardiovascular disease in Kerala: a qualitative study.

PubMed

Smith, Rebecca; Menon, Jaideep; Rajeev, Jaya G; Feinberg, Leo; Kumar, Raman Krishan; Banerjee, Amitava

2015-11-17

To assess the potential for using mHealth in cardiovascular disease (CVD) management in Kerala by exploring: (1) experiences and challenges of current CVD management; (2) current mobile phone use; (3) expectations of and barriers to mobile phone use in CVD management. Qualitative, semistructured, individual interviews. 5 primary health centres in Ernakulam district, Kerala, India. 15 participants in total from 3 stakeholder groups: 5 patients with CVD and/or its risk factors, 5 physicians treating CVD and 5 Accredited Social Health Activists (ASHAs). Patients were sampled for maximum variation on the basis of age, sex, CVD diagnoses and risk factors. All participants had access to a mobile phone. The main themes identified relating to the current challenges of CVD were poor patient disease knowledge, difficulties in implementing primary prevention and poor patient lifestyles. Participants noted phone calls as the main function of current mobile phone use. The expectations of mHealth use are to: improve accessibility to healthcare knowledge; provide reminders of appointments, medication and lifestyle changes; save time, money and travel; and improve ASHA job efficacy. All perceived barriers to mHealth were noted within physician interviews. These included fears of mobile phones negatively affecting physicians' roles, the usability of mobile phones, radiation and the need for physical consultations. There are three main potential uses of mHealth in this population: (1) as an educational tool, to improve health education and lifestyle behaviours; (2) to optimise the use of limited resources, by overcoming geographical barriers and financial constraints; (3) to improve use of healthcare, by providing appointment and treatment reminders in order to improve disease prevention and management. Successful mHealth design, which takes barriers into account, may complement current practice and optimise use of limited resources. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Potential for the use of mHealth in the management of cardiovascular disease in Kerala: a qualitative study

PubMed Central

Smith, Rebecca; Menon, Jaideep; Rajeev, Jaya G; Feinberg, Leo; Kumar, Raman Krishan; Banerjee, Amitava

2015-01-01

Objectives To assess the potential for using mHealth in cardiovascular disease (CVD) management in Kerala by exploring: (1) experiences and challenges of current CVD management; (2) current mobile phone use; (3) expectations of and barriers to mobile phone use in CVD management. Design Qualitative, semistructured, individual interviews. Setting 5 primary health centres in Ernakulam district, Kerala, India. Participants 15 participants in total from 3 stakeholder groups: 5 patients with CVD and/or its risk factors, 5 physicians treating CVD and 5 Accredited Social Health Activists (ASHAs). Patients were sampled for maximum variation on the basis of age, sex, CVD diagnoses and risk factors. All participants had access to a mobile phone. Results The main themes identified relating to the current challenges of CVD were poor patient disease knowledge, difficulties in implementing primary prevention and poor patient lifestyles. Participants noted phone calls as the main function of current mobile phone use. The expectations of mHealth use are to: improve accessibility to healthcare knowledge; provide reminders of appointments, medication and lifestyle changes; save time, money and travel; and improve ASHA job efficacy. All perceived barriers to mHealth were noted within physician interviews. These included fears of mobile phones negatively affecting physicians’ roles, the usability of mobile phones, radiation and the need for physical consultations. Conclusions There are three main potential uses of mHealth in this population: (1) as an educational tool, to improve health education and lifestyle behaviours; (2) to optimise the use of limited resources, by overcoming geographical barriers and financial constraints; (3) to improve use of healthcare, by providing appointment and treatment reminders in order to improve disease prevention and management. Successful mHealth design, which takes barriers into account, may complement current practice and optimise use of limited resources. PMID:26576813

Heavy agricultural workloads and low crop diversity are strong barriers to improving child feeding practices in the Bolivian Andes.

PubMed

Jones, Andrew D; Cruz Agudo, Yesmina; Galway, Lindsay; Bentley, Jeffery; Pinstrup-Andersen, Per

2012-11-01

Most nutrition initiatives to date aimed at improving infant and young child feeding (IYCF) have emphasized addressing knowledge gaps through behavior change messaging with less focus on addressing the underlying environmental barriers that may shape these behaviors. This research integrates an analysis of longitudinal dietary data with qualitative data on barriers to improved child feeding to identify the nature and extent of the barriers caregivers face to improving IYCF practices in a farming region of the Bolivian Andes, and to determine the relative influence of these barriers on caregivers' abilities to improve IYCF practices. Sixty-nine caregivers were selected from a sample of 331 households that participated in a longitudinal survey assessing changes in IYCF practices among caregivers with children aged 0-36 months from March 2009 to March 2010. Forty-nine barriers within 12 categories of barriers were identified through semi-structured interviews with the 69 caregivers. The most frequently reported barriers were those related to women's time dedicated to agricultural labor, the limited diversity of household agricultural production, and lack of support for child feeding from spouses and mothers-in-law. In multivariate analyses controlling for several variables that could potentially influence IYCF practices, these barriers were negatively associated with changes to the diversity of child diets, child dietary energy intake, and child meal frequency. While knowledge gaps and individual-level influences affected IYCF practices, physical and social caregiving environments in this region of Bolivia were even more important. Behavior change communication alone will likely not address the social and environmental barriers to improved child feeding that often prevent translation of improved knowledge into action. Particularly in rural regions, agriculture may strongly influence child feeding, not only indirectly through household food security, but also directly by affecting women's caregiving capacity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Heavy agricultural workloads and low crop diversity are strong barriers to improving child feeding practices in the Bolivian Andes

PubMed Central

Jones, Andrew D; Agudo, Yesmina Cruz; Galway, Lindsay; Bentley, Jeffery; Pinstrup-Andersen, Per

2012-01-01

Most nutrition initiatives to date aimed at improving infant and young child feeding (IYCF) have emphasized addressing knowledge gaps through behavior change messaging with less focus on addressing the underlying environmental barriers that may shape these behaviors. This research integrates an analysis of longitudinal dietary data with qualitative data on barriers to improved child feeding to identify the nature and extent of the barriers caregivers face to improving IYCF practices in a farming region of the Bolivian Andes, and to determine the relative influence of these barriers on caregivers’ abilities to improve IYCF practices. Sixty-nine caregivers were selected from a sample of 331 households that participated in a longitudinal survey assessing changes in IYCF practices among caregivers with children aged 0–36 months from March 2009 to March 2010. Forty-nine barriers within 12 categories of barriers were identified through semi-structured interviews with the 69 caregivers. The most frequently reported barriers were those related to women’s time dedicated to agricultural labor, the limited diversity of household agricultural production, and lack of support for child feeding from spouses and mothers-in-law. In multivariate analyses controlling for several variables that could potentially influence IYCF practices, these barriers were negatively associated with changes to the diversity of child diets, child dietary energy intake, and child meal frequency. While knowledge gaps and individual-level influences affected IYCF practices, physical and social caregiving environments in this region of Bolivia were even more important. Behavior change communication alone will likely not address the social and environmental barriers to improved child feeding that often prevent translation of improved knowledge into action. Particularly in rural regions, agriculture may strongly influence child feeding, not only indirectly through household food security, but also directly by affecting women’s caregiving capacity. PMID:22867863

Abnormal Barrier Function in Gastrointestinal Disorders.

PubMed

Farré, Ricard; Vicario, María

2017-01-01

There is increasing concern in identifying the mechanisms underlying the intimate control of the intestinal barrier, as deregulation of its function is strongly associated with digestive (organic and functional) and a number of non-digestive (schizophrenia, diabetes, sepsis, among others) disorders. The intestinal barrier is a complex and effective defensive functional system that operates to limit luminal antigen access to the internal milieu while maintaining nutrient and electrolyte absorption. Intestinal permeability to substances is mainly determined by the physicochemical properties of the barrier, with the epithelium, mucosal immunity, and neural activity playing a major role. In functional gastrointestinal disorders (FGIDs), the absence of structural or biochemical abnormalities that explain chronic symptoms is probably close to its end, as recent research is providing evidence of structural gut alterations, at least in certain subsets, mainly in functional dyspepsia (FD) and irritable bowel syndrome (IBS). These alterations are associated with increased permeability, which seems to reflect mucosal inflammation and neural activation. The participation of each anatomical and functional component of barrier function in homeostasis and intestinal dysfunction is described, with a special focus on FGIDs.

Biosynthetic Polymers as Functional Materials

PubMed Central

2016-01-01

The synthesis of functional polymers encoded with biomolecules has been an extensive area of research for decades. As such, a diverse toolbox of polymerization techniques and bioconjugation methods has been developed. The greatest impact of this work has been in biomedicine and biotechnology, where fully synthetic and naturally derived biomolecules are used cooperatively. Despite significant improvements in biocompatible and functionally diverse polymers, our success in the field is constrained by recognized limitations in polymer architecture control, structural dynamics, and biostabilization. This Perspective discusses the current status of functional biosynthetic polymers and highlights innovative strategies reported within the past five years that have made great strides in overcoming the aforementioned barriers. PMID:27375299

Learning to manage COPD: a qualitative study of reasons for attending and not attending a COPD-specific self-management programme.

PubMed

Sohanpal, Ratna; Seale, Clive; Taylor, Stephanie J C

2012-08-01

The aim of this article is to understand the reasons for attending a chronic obstructive pulmonary disease (COPD)-specific self-management (SM) programme and how attendance at such programmes might be improved. A total of 20 qualitative semistructured interviews were carried out with patients and with lay programme tutors involved in the Better Living with Long term Airways disease (BELLA) pilot trial. Thematic framework data analysis was used. Common reasons for participant attendance arising from patients and tutors include (1) desire to learn about SM, (2) social benefits of meeting others with COPD and (3) altruism. Patients' reasons for poor attendance include (1) being too ill or not feeling ill enough and (2) practical, physical and emotional barriers. Tutor's explanations for patients' poor attendance were (1) failure to accept their condition, (2) fear of making a change, (3) lack of adequate support, (4) guilt about smoking and (5) the 'scripted' nature of the course. Suggestions for improving programme participation included (1) having choice of several start dates, (2) minimal delay inviting participant onto courses, (3) planning for 'special needs'. Participation may be better amongst those who have accepted their condition or who are motivated towards improving their condition or to help others. Providing solutions for practical barriers may improve participation. However, alternatives to group-based interventions need to be developed for people with functional and emotional barriers to attendance.

Ginger Extract Suppresses Inflammatory Response and Maintains Barrier Function in Human Colonic Epithelial Caco-2 Cells Exposed to Inflammatory Mediators.

PubMed

Kim, Yunyoung; Kim, Dong-Min; Kim, Ji Yeon

2017-05-01

The beneficial effects of ginger in the management of gastrointestinal disturbances have been reported. In this study, the anti-inflammatory potential of ginger extract was assessed in a cellular model of gut inflammation. In addition, the effects of ginger extract and its major active compounds on intestinal barrier function were evaluated. The response of Caco-2 cells following exposure to a mixture of inflammatory mediators [interleukin [IL]-1β, 25 ng/mL; lipopolysaccharides [LPS], 10 ng/mL; tumor necrosis factor [TNF]-α, 50 ng/mL; and interferon [INF]-γ, 50 ng/mL] were assessed by measuring the levels of secreted IL-6 and IL-8. In addition, the mRNA levels of cyclooxygenase-2 and inducible nitric oxide synthase were measured. Moreover, the degree of nuclear factor (NF)-κB inhibition was examined, and the intestinal barrier function was determined by measuring the transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran transfer. It was observed that ginger extract and its constituents improved inflammatory responses by decreasing the levels of nitrite, PGE2, IL-6, and IL-8 via NF-κB inhibition. The ginger extract also increased the TEER and decreased the transfer of FITC-dextran from the apical side of the epithelium to the basolateral side. Taken together, these results show that ginger extract may be developed as a functional food for the maintenance of gastrointestinal health. © 2017 Institute of Food Technologists®.

Rat model of blood-brain barrier disruption to allow targeted neurovascular therapeutics.

PubMed

Martin, Jacob A; Maris, Alexander S; Ehtesham, Moneeb; Singer, Robert J

2012-11-30

Endothelial cells with tight junctions along with the basement membrane and astrocyte end feet surround cerebral blood vessels to form the blood-brain barrier(1). The barrier selectively excludes molecules from crossing between the blood and the brain based upon their size and charge. This function can impede the delivery of therapeutics for neurological disorders. A number of chemotherapeutic drugs, for example, will not effectively cross the blood-brain barrier to reach tumor cells(2). Thus, improving the delivery of drugs across the blood-brain barrier is an area of interest. The most prevalent methods for enhancing the delivery of drugs to the brain are direct cerebral infusion and blood-brain barrier disruption(3). Direct intracerebral infusion guarantees that therapies reach the brain; however, this method has a limited ability to disperse the drug(4). Blood-brain barrier disruption (BBBD) allows drugs to flow directly from the circulatory system into the brain and thus more effectively reach dispersed tumor cells. Three methods of barrier disruption include osmotic barrier disruption, pharmacological barrier disruption, and focused ultrasound with microbubbles. Osmotic disruption, pioneered by Neuwelt, uses a hypertonic solution of 25% mannitol that dehydrates the cells of the blood-brain barrier causing them to shrink and disrupt their tight junctions. Barrier disruption can also be accomplished pharmacologically with vasoactive compounds such as histamine(5) and bradykinin(6). This method, however, is selective primarily for the brain-tumor barrier(7). Additionally, RMP-7, an analog of the peptide bradykinin, was found to be inferior when compared head-to-head with osmotic BBBD with 25% mannitol(8). Another method, focused ultrasound (FUS) in conjunction with microbubble ultrasound contrast agents, has also been shown to reversibly open the blood-brain barrier(9). In comparison to FUS, though, 25% mannitol has a longer history of safety in human patients that makes it a proven tool for translational research(10-12). In order to accomplish BBBD, mannitol must be delivered at a high rate directly into the brain's arterial circulation. In humans, an endovascular catheter is guided to the brain where rapid, direct flow can be accomplished. This protocol models human BBBD as closely as possible. Following a cut-down to the bifurcation of the common carotid artery, a catheter is inserted retrograde into the ECA and used to deliver mannitol directly into the internal carotid artery (ICA) circulation. Propofol and N2O anesthesia are used for their ability to maximize the effectiveness of barrier disruption(13). If executed properly, this procedure has the ability to safely, effectively, and reversibly open the blood-brain barrier and improve the delivery of drugs that do not ordinarily reach the brain (8,13,14).

Thermal barrier coatings issues in advanced land-based gas turbines

NASA Technical Reports Server (NTRS)

Parks, W. P.; Lee, W. Y.; Wright, I. G.

1995-01-01

The Department of Energy's Advanced Turbine System (ATS) program is aimed at forecasting the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS turbines will require the use of different criteria in the design of the materials for the critical hot gas path components. In particular, thermal barrier coatings will be an essential feature of the hot gas path components in these machines. While such coatings are routinely used in high-performance aircraft engines and are becoming established in land-based turbines, the requirements of the ATS turbine application are sufficiently different that significant improvements in thermal barrier coating technology will be necessary. In particular, it appears that thermal barrier coatings will have to function on all airfoil sections of the first stage vanes and blades to provide the significant temperature reduction required. In contrast, such coatings applied to the blades and vances of advanced aircraft engines are intended primarily to reduce air cooling requirements and extend component lifetime; failure of those coatings can be tolerated without jeopardizing mechanical or corrosion performance. A major difference is that in ATS turbines these components will be totally reliant on thermal barrier coatings which will, therefore, need to be highly reliable even over the leading edges of first stage blades. Obviously, the ATS program provides a very challenging opportunity for TBC's, and involves some significant opportunities to extend this technology.

Investigating the Efficacy of Novel TrkB Agonists to Augment Stroke Recovery

NASA Astrophysics Data System (ADS)

Warraich, Zuha

Stroke remains the leading cause of adult disability in developed countries. Most survivors live with residual motor impairments that severely diminish independence and quality of life. After stroke, the only accepted treatment for these patients is motor rehabilitation. However, the amount and kind of rehabilitation required to induce clinically significant improvements in motor function is rarely given due to the constraints of our current health care system. Research reported in this dissertation contributes towards developing adjuvant therapies that may augment the impact of motor rehabilitation and improve functional outcome. These studies have demonstrated reorganization of maps within motor cortex as a function of experience in both healthy and brain-injured animals by using intracortical microstimulation technique. Furthermore, synaptic plasticity has been identified as a key neural mechanism in directing motor map plasticity, evidenced by restoration of movement representations within the spared cortical tissue accompanied by increase in synapse number translating into motor improvement after stroke. There is increasing evidence that brain-derived neurotrophic factor (BDNF) modulates synaptic and morphological plasticity in the developing and mature nervous system. Unfortunately, BDNF itself is a poor candidate because of its short half-life, low penetration through the blood brain barrier, and activating multiple receptor units, p75 and TrkB on the neuronal membrane. In order to circumvent this problem efficacy of two recently developed novel TrkB agonists, LM22A-4 and 7,8-dihydroxyflavone, that actively penetrate the blood brain barrier and enhance functional recovery. Findings from these dissertation studies indicate that administration of these pharmacological compounds, accompanied by motor rehabilitation provide a powerful therapeutic tool for stroke recovery.

Implementation of the guidelines for targeted temperature management after cardiac arrest: a longitudinal qualitative study of barriers and facilitators perceived by hospital resuscitation champions.

PubMed

Kim, Young-Min; Lee, Seung Joon; Jo, Sun Jin; Park, Kyu Nam

2016-01-05

To identify the barriers to and facilitators of implementing guidelines for targeted temperature management (TTM) after cardiac arrest perceived by hospital resuscitation champions and to investigate the changes in their perceptions over the early implementation period. A longitudinal qualitative study (up to 2 serial semistructured interviews over 1 year and focus groups). The individual interviews and focus groups were transcribed and coded by 2 independent assessors. Contents were analysed thematically; group interaction was also examined. 21 hospitals, including community and tertiary care centres in South Korea. 21 hospital champions (14 acting champions and 7 managerial champions). The final data set included 40 interviews and 2 focus groups. The identified barriers and facilitators could be classified into 3 major themes: (1) healthcare professionals' perceptions of the guidelines and protocols, (2) interdisciplinary and interprofessional collaboration and (3) organisational resources. Lack of resources was the most commonly agreed on barrier for the acting champions, whereas lack of interdisciplinary collaboration was the most common barrier for the managerial champions. Educational activities and sharing successfully treated cases were the most frequently identified facilitators. Most of the participants identified and agreed that cooling equipment was an important barrier as well as a facilitator of successful TTM implementation. Perception of the guidelines and protocols has improved with the accumulation of clinical experience over the study period. Healthcare professionals' internal barriers to TTM implementation may be influenced by new guidelines and can be changed with the accumulation of successful clinical experiences during the early implementation period. Promoting interprofessional and interdisciplinary collaboration through educational activities and the use of cooling equipment with an automated feedback function can improve adherence to guidelines in hospitals with limited human resources in critical care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Implementation of the guidelines for targeted temperature management after cardiac arrest: a longitudinal qualitative study of barriers and facilitators perceived by hospital resuscitation champions

PubMed Central

Kim, Young-Min; Lee, Seung Joon; Jo, Sun Jin; Park, Kyu Nam

2016-01-01

Objectives To identify the barriers to and facilitators of implementing guidelines for targeted temperature management (TTM) after cardiac arrest perceived by hospital resuscitation champions and to investigate the changes in their perceptions over the early implementation period. Design A longitudinal qualitative study (up to 2 serial semistructured interviews over 1 year and focus groups). The individual interviews and focus groups were transcribed and coded by 2 independent assessors. Contents were analysed thematically; group interaction was also examined. Setting 21 hospitals, including community and tertiary care centres in South Korea. Participants 21 hospital champions (14 acting champions and 7 managerial champions). Results The final data set included 40 interviews and 2 focus groups. The identified barriers and facilitators could be classified into 3 major themes: (1) healthcare professionals’ perceptions of the guidelines and protocols, (2) interdisciplinary and interprofessional collaboration and (3) organisational resources. Lack of resources was the most commonly agreed on barrier for the acting champions, whereas lack of interdisciplinary collaboration was the most common barrier for the managerial champions. Educational activities and sharing successfully treated cases were the most frequently identified facilitators. Most of the participants identified and agreed that cooling equipment was an important barrier as well as a facilitator of successful TTM implementation. Perception of the guidelines and protocols has improved with the accumulation of clinical experience over the study period. Conclusions Healthcare professionals’ internal barriers to TTM implementation may be influenced by new guidelines and can be changed with the accumulation of successful clinical experiences during the early implementation period. Promoting interprofessional and interdisciplinary collaboration through educational activities and the use of cooling equipment with an automated feedback function can improve adherence to guidelines in hospitals with limited human resources in critical care. PMID:26733568

Lactobacillus plantarum Enhanced IL-22 Production in Natural Killer (NK) Cells That Protect the Integrity of Intestinal Epithelial Cell Barrier Damaged by Enterotoxigenic Escherichia coli.

PubMed

Qiu, Yueqin; Jiang, Zongyong; Hu, Shenglan; Wang, Li; Ma, Xianyong; Yang, Xuefen

2017-11-13

Interleukin (IL)-22-producing Natural Killer (NK) cells protect the gut epithelial cell barrier from pathogens. A strain of probiotics, Lactobacillus plantarum (L. plantarum, LP), was previously found by our laboratory to significantly improve the mucosal barrier integrity and function of the small intestine in pigs. However, it was unclear whether LP benefited the intestinal mucosal barrier via interactions with the intestinal NK cells. The present study, therefore, was focused on the therapeutic effect of NK cells that were stimulated by LP on attenuating enterotoxigenic Escherichia coli (ETEC)-induced the damage to the integrity of the epithelial cell barrier. The results showed that LP can efficiently increase protein levels of the natural cytotoxicity receptor (NCR) family, and the expression levels of IL-22 mRNA and protein in NK cells. Transfer of NK cells stimulated by LP conferred protection against ETEC K88-induced intestinal epithelial barrier damage in NCM460 cells. We found that NK cells stimulated by LP could partially offset the reduction in NCM460 cell monolayers transepithelial electrical resistance (TEER) caused by ETEC K88, and increase ZO-1 and occludin mRNA and protein expressions by ETEC K88-infected NCM460 cells. Furthermore, adding NK cells that were stimulated by LP to ETEC K88-infected NCM460cells, IL-22R1, p-Stat3, and p-Tyk2 expression by NCM460 cells was increased. Mechanistic experiment showed that NK cells stimulated by LP lost the function of maintaining TEER of NCM460 cells challenged with ETEC K88, when polyclonal anti-IL-22 antibody was used to block IL-22 production. Collectively, our results suggested that LP stimulation of NK could enhance IL-22 production, which might be able to provide defense against ETEC-induced damage to the integrity of intestinal epithelial barrier.

[Advance in studies on food allergy mechanism based on gut barrier].

PubMed

Wang, Juan-hong; Li, Huan-zhou; Li, Meng; Pan, Su-hua

2015-04-01

Food allergies, as a type of adverse immune-mediated reactions to ingested food proteins, have become a serious public health issue that harms children and adults health, with increasing incidence year by year. However, without effective therapy for food allergies, doctors-have mostly advised to avoid allergens and provided symptomatic treatment. According to the findings of many studies, allergic diseases are correlated with intestinal barrier function injury, as evidenced by the significant increase in the intestinal permeability among patients with food allergies. In this paper, recent studies on correlations between food allergies and intestinal barrier functions, intestinal barrier function injury mechanisms of allergic foods and food allergy intervention strategies based on intestinal barrier functions were summarized to provide reference for laboratory researches and clinical treatment of food allergic diseases.

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions (Invited paper)

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

An oncological view on the blood-testis barrier.

PubMed

Bart, Joost; Groen, Harry J M; van der Graaf, Winette T A; Hollema, Harry; Hendrikse, N Harry; Vaalburg, Willem; Sleijfer, Dirk T; de Vries, Elisabeth G E

2002-06-01

The function of the blood-testis barrier is to protect germ cells from harmful influences; thus, it also impedes the delivery of chemotherapeutic drugs to the testis. The barrier has three components: first, a physicochemical barrier consisting of continuous capillaries, Sertoli cells in the tubular wall, connected together with narrow tight junctions, and a myoid-cell layer around the seminiferous tubule. Second, an efflux-pump barrier that contains P-glycoprotein in the luminal capillary endothelium and on the myoid-cell layer; and multidrug-resistance associated protein 1 located basolaterally on Sertoli cells. Third, an immunological barrier, consisting of Fas ligand on Sertoli cells. Inhibition of P-glycoprotein function offers the opportunity to increase the delivery of cytotoxic drugs to the testis. In the future, visualisation of function in the blood-testis barrier may also be helpful to identify groups of patients in whom testis conservation is safe or to select drugs that are less harmful to fertility.

Diabetes Self-management Training in a Virtual Environment.

PubMed

Reagan, Louise; Pereira, Katherine; Jefferson, Vanessa; Evans Kreider, Kathryn; Totten, Susan; D'Eramo Melkus, Gail; Johnson, Constance; Vorderstrasse, Allison

2017-08-01

Diabetes self-management training (DSMT) improves diabetes health outcomes. However, low numbers of patients receive DSMT. Using virtual environments (VEs) for DSMT is an innovative approach to removing barriers for patients. The purpose of this paper is to describe the experience of health professionals and diabetes educators establishing and teaching DSMT in a VE, Diabetes LIVE© (Learning in Virtual Environments), and the implications for future use of VEs in DSMT. It was found that providing DSMT in a VE preserves real-time interaction between patients and educators. To facilitate ongoing patient learning and engagement, the DSMT curriculum was expanded beyond the core content as "Above and Beyond" topics. Using a VE for DSMT presents challenges and opportunities. Challenges include overcoming technological barriers and improving comfort levels to orient educators and patients to the functionality of the VE. Opportunities include overcoming barriers to reaching patients, particularly given the diabetes epidemic and relatively small number of diabetes educators. Using a VE also affords a simulated community for experiential learning. VEs may become powerful tools for diabetes and other health educators to reach patients. Ongoing education and support are vital to successful self-management of chronic disease.

Hope for successful implementation of psychosocial/psychiatric rehabilitation in the forensic mental health setting.

PubMed

Brown, Stephanie A; Lewis, Kent

2015-12-01

To explore staff perceptions of the successes and barriers to implementation of the psychosocial/psychiatric rehabilitation (PSR) model in the forensic mental health setting and identify staff supports needed for greater implementation. A qualitative descriptive design was used and staff focus group data was analyzed using the constant comparative method. All aspects of PSR are being implemented in the forensic setting. Barriers limiting comprehensive implementation include hospital processes and functions, legal components, client clinical presentation, staff attributes and interactions, and lack of resources. To foster greater implementation, employees require support to improve interprofessional interactions and acquire additional resources and education. Strengthening existing successes and addressing barriers identified will foster greater PSR implementation in the forensic setting. Adjusting the physical environment, streamlining documentation, shifting focus from security to rehabilitation goals, and adapting PSR principles to various levels of illness acuity and stages of treatment would enhance PSR implementation. A management focus on improving staff morale, self-care, peer support, team cohesion, and communication would limit burnout and increase successful implementation of PSR. Additional educational opportunities and ongoing training are suggested to support a unified understanding and sustained approach to PSR implementation in the forensic setting. (c) 2015 APA, all rights reserved).

Exploring older adults' patterns and perceptions of exercise after hip fracture.

PubMed

Gorman, Erin; Chudyk, Anna M; Hoppmann, Christiane A; Hanson, Heather M; Guy, Pierre; Sims-Gould, Joanie; Ashe, Maureen C

2013-01-01

To identify exercise patterns and perceived barriers, enablers, and motivators to engaging in exercise for older adults following hip fracture. Telephone interviews were conducted with older adults (aged 62-97 y) within 1 year after hip fracture. Participants were asked about basic demographic information; level of mobility before hip fracture; current level of mobility; and barriers, enablers, and motivators to participating in exercise. A total of 32 older adults successfully recovering after hip fracture completed the telephone interviews. Participants reported few problems with their mobility, and all were engaging in exercise. There were few reported barriers to exercise; the most common were health-related concerns (pain, fatigue, illness, or injury). The most frequently reported enablers were intrinsic factors (determination, seeing improvements, and making exercise part of their daily routine); in particular, the most common motivator to exercise was recovery of function to improve mobility and complete daily and leisure activities. This study highlights the responses of a group of older adults recovering well after hip fracture. Older adults engage in exercise despite the potential limitations associated with a hip fracture. Participants' responses underscore the importance of intrinsic factors and suggest avenues for future investigation.

A role for IL-22 in the relationship between intestinal helminths, gut microbiota and mucosal immunity.

PubMed

Leung, Jacqueline M; Loke, P'ng

2013-03-01

The intestinal tract is home to nematodes as well as commensal bacteria (microbiota), which have coevolved with the mammalian host. The mucosal immune system must balance between an appropriate response to dangerous pathogens and an inappropriate response to commensal microbiota that may breach the epithelial barrier, in order to maintain intestinal homeostasis. IL-22 has been shown to play a critical role in maintaining barrier homeostasis against intestinal pathogens and commensal bacteria. Here we review the advances in our understanding of the role of IL-22 in helminth infections, as well as in response to commensal and pathogenic bacteria of the intestinal tract. We then consider the relationship between intestinal helminths and gut microbiota and hypothesize that this relationship may explain how helminths may improve symptoms of inflammatory bowel diseases. We propose that by inducing an immune response that includes IL-22, intestinal helminths may enhance the mucosal barrier function of the intestinal epithelium. This may restore the mucosal microbiota populations from dysbiosis associated with colitis and improve intestinal homeostasis. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Applications of Nanomaterials in Food Packaging.

PubMed

Bumbudsanpharoke, Nattinee; Choi, Jungwook; Ko, Seonghyuk

2015-09-01

Nanomaterials have drawn great interest in recent years due to their extraordinary properties that make them advantageous in food packaging applications. Specifically, nanoparticles can impart significant barrier properties, as well as mechanical, optical, catalytic, and antimicrobial properties into packaging. Silver nanoparticles (AgNPs) and nanoclay account for the majority of the nano-enabled food packaging on the market, while others, such as nano-zinc oxide (ZnO) and titanium, share less of the current market. In current food packaging, these nanomaterials are primarily used to impart antimicrobial function and to improve barrier properties, thereby extending the shelf life and freshness of packaged food. On the other hand, there is growing concern about the migration of nanomaterials from food contact materials to foodstuffs and its associated potential risks. Indeed, insufficient data about environmental and human safety assessments of migration and exposure of nanomaterials are hindering their market growth. To overcome this barrier, the public believes that legislation from government agencies is critical. This review provides an overview of the characteristics and functions of major nanomaterials that are commonly applied to food packaging, including available and near- future products. Migration research, safety issues, and public concerns are also discussed.

Designing solid-liquid interphases for sodium batteries.

PubMed

Choudhury, Snehashis; Wei, Shuya; Ozhabes, Yalcin; Gunceler, Deniz; Zachman, Michael J; Tu, Zhengyuan; Shin, Jung Hwan; Nath, Pooja; Agrawal, Akanksha; Kourkoutis, Lena F; Arias, Tomas A; Archer, Lynden A

2017-10-12

Secondary batteries based on earth-abundant sodium metal anodes are desirable for both stationary and portable electrical energy storage. Room-temperature sodium metal batteries are impractical today because morphological instability during recharge drives rough, dendritic electrodeposition. Chemical instability of liquid electrolytes also leads to premature cell failure as a result of parasitic reactions with the anode. Here we use joint density-functional theoretical analysis to show that the surface diffusion barrier for sodium ion transport is a sensitive function of the chemistry of solid-electrolyte interphase. In particular, we find that a sodium bromide interphase presents an exceptionally low energy barrier to ion transport, comparable to that of metallic magnesium. We evaluate this prediction by means of electrochemical measurements and direct visualization studies. These experiments reveal an approximately three-fold reduction in activation energy for ion transport at a sodium bromide interphase. Direct visualization of sodium electrodeposition confirms large improvements in stability of sodium deposition at sodium bromide-rich interphases.The chemistry at the interface between electrolyte and electrode plays a critical role in determining battery performance. Here, the authors show that a NaBr enriched solid-electrolyte interphase can lower the surface diffusion barrier for sodium ions, enabling stable electrodeposition.

Bifidobacterium breve prevents necrotising enterocolitis by suppressing inflammatory responses in a preterm rat model.

PubMed

Satoh, T; Izumi, H; Iwabuchi, N; Odamaki, T; Namba, K; Abe, F; Xiao, J Z

2016-02-01

Necrotising enterocolitis (NEC) is associated with inflammatory responses and barrier dysfunction in the gut. In this study, we investigated the effect of Bifidobacterium breve M-16V on factors related to NEC development using an experimental rat model. Caesarean-sectioned rats were given formula milk with or without B. breve M-16V by oral gavage thrice daily, and experimental NEC was induced by exposing the rats to hypoxic conditions. Naturally delivered rats that were reared by their mother were used as healthy controls. The pathological score of NEC and the expression of molecules related to inflammatory responses and the barrier function were assessed in the ileum. B. breve M-16V reduced the pathological scores of NEC and resulted in some improvement in survivability. B. breve M-16V suppressed the increased expression of molecules related to inflammation and barrier function that resulted from NEC induction. B. breve M-16V normalised Toll-like receptor (TRL)4 expression and enhanced TLR2 expression. Our data suggest that B. breve M-16V prevents NEC development by modulating TLR expressions and suppressing inflammatory responses in a rat model.

Gelatin tannate and tyndallized probiotics: a novel approach for treatment of diarrhea.

PubMed

Lopetuso, L; Graziani, C; Guarino, A; Lamborghini, A; Masi, S; Stanghellini, V

2017-02-01

Intestinal permeability impairment is implicated in many gastrointestinal (GI) diseases. Chronic diarrhea, defined as the presence of diarrhea for more than 3 weeks in adults and 2 weeks in children, requires a different diagnostic and therapeutic work-up than acute diarrhea. Gelatin tannate, by reducing the clinical activity of acute colitis and the proinflammatory effects of lipopolysaccharide (LPS), is emerging as a mucosal barrier protector. New therapeutic strategies focusing on the physiological function of the intestinal barrier, may offer an innovative approach for the clinical improvement of highly debilitating chronic GI diseases. We review the available data on the role of gelatin tannate and tyndallized probiotics in the treatment of diarrhea. Gelatin tannate and tyndallized probiotics can be used to re-establish the physiological functions of the gut barrier, as well as for preventing dysbiosis. There is evidence that due to their particular properties, gelatin tannate and tyndallized probiotics are highly effective in the treatment of acute gastroenteritis and may be especially indicated in the management of moderate and prolonged diarrhea. Gelatin tannate and tyndallized probiotics may be effective in the management of chronic diarrhea. Further clinical trials are necessary to further explore their effects in clinical practice.

Mononuclear phagocytes as a target, not a barrier, for drug delivery.

PubMed

Yong, Seok-Beom; Song, Yoonsung; Kim, Hyung Jin; Ain, Qurrat Ul; Kim, Yong-Hee

2017-08-10

Mononuclear phagocytes have been generally recognized as a barrier to drug delivery. Recently, a new understanding of mononuclear phagocytes (MPS) ontogeny has surfaced and their functions in disease have been unveiled, demonstrating the need for re-evaluation of perspectives on mononuclear phagocytes in drug delivery. In this review, we described mononuclear phagocyte biology and focus on their accumulation mechanisms in disease sites with explanations of monocyte heterogeneity. In the 'MPS as a barrier' section, we summarized recent studies on mechanisms to avoid phagocytosis based on two different biological principles: protein adsorption and self-recognition. In the 'MPS as a target' section, more detailed descriptions were given on mononuclear phagocyte-targeted drug delivery systems and their applications to various diseases. Collectively, we emphasize in this review that mononuclear phagocytes are potent targets for future drug delivery systems. Mononuclear phagocyte-targeted delivery systems should be created with an understanding of mononuclear phagocyte ontogeny and pathology. Each specific subset of phagocytes should be targeted differently by location and function for improved disease-drug delivery while avoiding RES clearance such as Kupffer cells and splenic macrophages. Copyright © 2017 Elsevier B.V. All rights reserved.

Brief Report: Vocational Outcomes for Young Adults with Autism Spectrum Disorders at Six Months after Virtual Reality Job Interview Training

ERIC Educational Resources Information Center

Smith, Matthew J.; Fleming, Michael F.; Wright, Michael A.; Losh, Molly; Humm, Laura Boteler; Olsen, Dale; Bell, Morris D.

2015-01-01

Young adults with high-functioning autism spectrum disorder (ASD) have low employment rates and job interviewing presents a critical barrier to employment for them. Results from a prior randomized controlled efficacy trial suggested virtual reality job interview training (VR-JIT) improved interviewing skills among trainees with ASD, but not…

Improving Homework Compliance in Career Counseling with a Behavioral Activation Functional Assessment Procedure: A Pilot Study

ERIC Educational Resources Information Center

Baruch, David E.; Kanter, Jonathan W.; Bowe, William M.; Pfennig, Sherri L.

2011-01-01

Behavioral activation has emerged as a widely used treatment for depression in a number of health care settings due to its concrete, straightforward emphasis on out-of-session client homework, but it lacks explicit guidelines for identifying and overcoming barriers that interfere with homework completion. The purpose of this pilot study was to…

Food nanotechnology – an overview

PubMed Central

Sekhon, Bhupinder S

2010-01-01

Food nanotechnology is an area of emerging interest and opens up a whole universe of new possibilities for the food industry. The basic categories of nanotechnology applications and functionalities currently in the development of food packaging include: the improvement of plastic materials barriers, the incorporation of active components that can deliver functional attributes beyond those of conventional active packaging, and the sensing and signaling of relevant information. Nano food packaging materials may extend food life, improve food safety, alert consumers that food is contaminated or spoiled, repair tears in packaging, and even release preservatives to extend the life of the food in the package. Nanotechnology applications in the food industry can be utilized to detect bacteria in packaging, or produce stronger flavors and color quality, and safety by increasing the barrier properties. Nanotechnology holds great promise to provide benefits not just within food products but also around food products. In fact, nanotechnology introduces new chances for innovation in the food industry at immense speed, but uncertainty and health concerns are also emerging. EU/WE/global legislation for the regulation of nanotechnology in food are meager. Moreover, current legislation appears unsuitable to nanotechnology specificity. PMID:24198465

Spatial averaging for small molecule diffusion in condensed phase environments

NASA Astrophysics Data System (ADS)

Plattner, Nuria; Doll, J. D.; Meuwly, Markus

2010-07-01

Spatial averaging is a new approach for sampling rare-event problems. The approach modifies the importance function which improves the sampling efficiency while keeping a defined relation to the original statistical distribution. In this work, spatial averaging is applied to multidimensional systems for typical problems arising in physical chemistry. They include (I) a CO molecule diffusing on an amorphous ice surface, (II) a hydrogen molecule probing favorable positions in amorphous ice, and (III) CO migration in myoglobin. The systems encompass a wide range of energy barriers and for all of them spatial averaging is found to outperform conventional Metropolis Monte Carlo. It is also found that optimal simulation parameters are surprisingly similar for the different systems studied, in particular, the radius of the point cloud over which the potential energy function is averaged. For H2 diffusing in amorphous ice it is found that facile migration is possible which is in agreement with previous suggestions from experiment. The free energy barriers involved are typically lower than 1 kcal/mol. Spatial averaging simulations for CO in myoglobin are able to locate all currently characterized metastable states. Overall, it is found that spatial averaging considerably improves the sampling of configurational space.

Starting a new conversation: Engaging Veterans with spinal cord injury in discussions of what function means to them, the barriers/facilitators they encounter, and the adaptations they use to optimize function.

PubMed

Hill, Jennifer N; Balbale, Salva; Lones, Keshonna; LaVela, Sherri L

2017-01-01

Assessments of function in persons with spinal cord injury (SCI) often utilize pre-defined constructs and measures without consideration of patient context, including how patients define function and what matters to them. We utilized photovoice to understand how individuals define function, facilitators and barriers to function, and adaptations to support functioning. Veterans with SCI were provided with cameras and guidelines to take photographs of things that: (1) help with functioning, (2) are barriers to function, and (3) represent adaptations used to support functioning. Interviews to discuss photographs followed and were audio-recorded, transcribed, and analyzed using grounded-thematic coding. Nvivo 8 was used to store and organize data. Participants (n = 9) were male (89%), Caucasian (67%), had paraplegia (75%), averaged 64 years of age, and were injured, on average, for 22 years. Function was described in several ways: the concept of 'normalcy,' aspects of daily living, and ability to be independent. Facilitators included: helpful tools, physical therapy/therapists, transportation, and caregivers. Barriers included: wheelchair-related issues and interior/exterior barriers both in the community and in the hospital. Examples of adaptations included: traditional examples like ramps, and also creative examples like the use of rubber bands on a can to help with grip. Patient-perspectives elicited in-depth information that expanded the common definition of function by highlighting the concept of "normality," facilitators and barriers to function, and adaptations to optimize function. These insights emphasize function within a patient-context, emphasizing a holistic definition of function that can be used to develop personalized, patient-driven care plans. Published by Elsevier Inc.

Super Oxygen and Improved Water Vapor Barrier of Polypropylene Film with Polyelectrolyte Multilayer Nanocoatings.

PubMed

Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C

2016-06-01

Biaxially oriented polypropylene (BOPP) is widely used in packaging. Although its orientation increases mechanical strength and clarity, BOPP suffers from a high oxygen transmission rate (OTR). Multilayer thin films are deposited from water using layer-by-layer (LbL) assembly. Polyethylenimine (PEI) is combined with either poly(acrylic acid) (PAA) or vermiculite (VMT) clay to impart high oxygen barrier. A 30-bilayer PEI/VMT nanocoating (226 nm thick) improves the OTR of 17.8 μm thick BOPP by more than 30X, rivaling most inorganic coatings. PEI/PAA multilayers achieve comparable barrier with only 12 bilayers due to greater thickness, but these films exhibit increased oxygen permeability at high humidity. The PEI/VMT coatings actually exhibit improved oxygen barrier at high humidity (and also improve moisture barrier by more than 40%). This high barrier BOPP meets the criteria for sensitive food and some electronics packaging applications. Additionally, this water-based coating technology is cost effective and provides an opportunity to produce high barrier polypropylene film on an industrial scale. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel approach for the improvement of electrostatic behaviour of physically doped TFET using plasma formation and shortening of gate electrode with hetero-gate dielectric

NASA Astrophysics Data System (ADS)

Soni, Deepak; Sharma, Dheeraj; Aslam, Mohd.; Yadav, Shivendra

2018-04-01

This article presents a new device configuration to enhance current drivability and suppress negative conduction (ambipolar conduction) with improved RF characteristics of physically doped TFET. Here, we used a new approach to get excellent electrical characteristics of hetero-dielectric short gate source electrode TFET (HD-SG SE-TFET) by depositing a metal electrode of 5.93 eV work function over the heavily doped source (P+) region. Deposition of metal electrode induces the plasma (thin layer) of holes under the Si/HfO2 interface due to work function difference of metal and semiconductor. Plasma layer of holes is advantageous to increase abruptness as well as decrease the tunneling barrier at source/channel junction for attaining higher tunneling rate of charge carriers (i.e., electrons), which turns into 86.66 times higher ON-state current compared with the conventional physically doped TFET (C-TFET). Along with metal electrode deposition, gate electrode is under-lapped for inducing asymmetrical concentration of charge carriers in the channel region, which is helpful for widening the tunneling barrier width at the drain/channel interface. Consequently, HD-SG SE-TFET shows suppression of ambipolar behavior with reduction in gate-to-drain capacitance which is beneficial for improvement in RF performance. Furthermore, the effectiveness of hetero-gate dielectric concept has been used for improving the RF performance. Furthermore, reliability of C-TFET and proposed structures has been confirmed in term of linearity.

Dpf Analyses Yield Fully Analytic Potentials for the B ^1Πu ``BARRIER'' States of {Rb}_2 and {Li}_2 and AN Improved Ground-State Well Depth for {Rb}_2

NASA Astrophysics Data System (ADS)

Slaughter, Kai; Dattani, Nikesh S.; Amiot, Claude S.; Ross, Amanda J.; Le Roy, Robert J.

2015-06-01

Determining full model potential energy functions for molecular states that have a `natural' rotationless barrier which protrudes above the potential asymptote, such as the B ^1Π_u states of alkali dimers, is a challenging problem. The present work extends our previous Direct-Potential-Fit (DPF) analysis of data for the B ^1Π_u state of Li_2 by introducing a more sophisticated model for the long-range tail of the fully analytic `Double Exponential Long-Range' (DELR) potential function form^a that takes account of the interstate coupling that occurs near the asymptotes of nS+nP alkali dimers. This type of analysis is then applied to data for the B ^1Π_u state of Rb_2, and a concurrent extension of the DPF analysis of Seto and Le Roy yields an improved fully analytic potential energy function for its ground X ^1σ_g^+ state. The effect of taking account of the long-range inter-state coupling on the shapes of the outer walls of the B ^1Π_u state potential functions for these two species will also be examined. Y. Huang and R.J. Le Roy, J. Chem. Phys., 119, 7398 (2003) M. Aubert-Frécon and G. Hadinger and S. Magnier and S. Rousseau, J. Mol. Spectosc., 288, 182 (1998). J.Y. Seto and R.J. Le Roy, J. Chem. Phys., 113, 3067 (2000).

Bioactives from probiotics for dermal health: functions and benefits.

PubMed

Lew, L-C; Liong, M-T

2013-05-01

Probiotics have been extensively reviewed for decades, emphasizing on improving general gut health. Recently, more studies showed that probiotics may exert other health-promoting effects beyond gut well-being, attributed to the rise of the gut-brain axis correlations. Some of these new benefits include skin health such as improving atopic eczema, atopic dermatitis, healing of burn and scars, skin-rejuvenating properties and improving skin innate immunity. Increasing evidence has also showed that bacterial compounds such as cell wall fragments, their metabolites and dead bacteria can elicit certain immune responses on the skin and improve skin barrier functions. This review aimed to underline the mechanisms or the exact compounds underlying the benefits of bacterial extract on the skin based on evidences from in vivo and in vitro studies. This review could be of help in screening of probiotic strains with potential dermal enhancing properties for topical applications. © 2013 The Society for Applied Microbiology.

Thermal barrier coating resistant to sintering

DOEpatents

Subramanian, Ramesh; Seth, Brig B.

2005-08-23

A device (10) is made, having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10), is not soluble with the underlying ceramic layer (16) and is applied by a process that is not an electron beam physical vapor deposition process. The sintering inhibiting material (22) has a morphology adapted to improve the functionality of the sintering inhibiting material (22), characterized as continuous, nodule, rivulet, grain, crack, flake and combinations thereof and being disposed within at least some of the vertical and horizontal gaps.

Geophysical Assessment of the Control of a Jetty on a Barrier Beach and Estuary System

NASA Astrophysics Data System (ADS)

Ulrich, C.; Hubbard, S.; Delaney, C.; Seymour, D.; Blom, K.; Black, W.

2013-12-01

An evaluation is underway at the Goat Rock State Beach, which is located at the mouth of the Russian River near Jenner, CA. The study focuses on quantifying the influence of a man made jetty on the functioning of a barrier beach and associated implications for estuary fish habitat and flood control. Flow through the beach results from water level differences between the estuary and the ocean. When the estuary is closed or perched, one of the potential major sources of outflow from the lagoon is seepage flow through the barrier beach. The location and design of the jetty could be altering subsurface flow paths through the jetty and possibly impeding or enhancing subsurface flow where the jetty is still intact. This will result in unnatural connectivity between the ocean and the estuary leading to atypical surface water elevations and possibly salinity imbalance. Results of the assessment will enable the Sonoma County Water Agency to understand how the jetty affects formation of the barrier beach and water surface elevations within the estuary. As one aspect of the evaluation, we are using geophysical methods to monitor seepage through the jetty as well as through the beach berm. We are using multiple surface geophysical methods, including: electrical resistivity, seismic refraction, ground penetrating radar, and electromagnetic methods. In general, seismic data are being used to characterize deeper bedrock controls on beach barrier functioning such as, channeling of estuarine water beneath the barrier beach. Electrical and electromagnetic methods are being used to characterize the beach sediment layers that could contribute to preferential flow paths during tide cycles in addition to preferential flow paths created by the jetty structure. Time-lapse electrical and electromagnetic data are being used to monitor moisture changes and mixing of saline and fresh water within the beach berm. Ground penetrating radar data are being used to delineate the geometry of the (often buried) jetty. All data are being integrated with topography, tidal and hydrological information, and electrical conductivity and temperature data from monitoring wells. These results are expected to improve the overall understanding of the jetty's effects on beach permeability and will better improve the understanding of the jetty's influence on estuary habitats and flood risk.

Conceptual uncertainty in crystalline bedrock: Is simple evaluation the only practical approach?

USGS Publications Warehouse

Geier, J.; Voss, C.I.; Dverstorp, B.

2002-01-01

A simple evaluation can be used to characterize the capacity of crystalline bedrock to act as a barrier to release radionuclides from a nuclear waste repository. Physically plausible bounds on groundwater flow and an effective transport-resistance parameter are estimated based on fundamental principles and idealized models of pore geometry. Application to an intensively characterized site in Sweden shows that, due to high spatial variability and uncertainty regarding properties of transport paths, the uncertainty associated with the geological barrier is too high to allow meaningful discrimination between good and poor performance. Application of more complex (stochastic-continuum and discrete-fracture-network) models does not yield a significant improvement in the resolution of geological barrier performance. Comparison with seven other less intensively characterized crystalline study sites in Sweden leads to similar results, raising a question as to what extent the geological barrier function can be characterized by state-of-the art site investigation methods prior to repository construction. A simple evaluation provides a simple and robust practical approach for inclusion in performance assessment.

Conceptual uncertainty in crystalline bedrock: Is simple evaluation the only practical approach?

USGS Publications Warehouse

Geier, J.; Voss, C.I.; Dverstorp, B.

2002-01-01

A simple evaluation can be used to characterise the capacity of crystalline bedrock to act as a barrier to releases of radionuclides from a nuclear waste repository. Physically plausible bounds on groundwater flow and an effective transport-resistance parameter are estimated based on fundamental principles and idealised models of pore geometry. Application to an intensively characterised site in Sweden shows that, due to high spatial variability and uncertainty regarding properties of transport paths, the uncertainty associated with the geological barrier is too high to allow meaningful discrimination between good and poor performance. Application of more complex (stochastic-continuum and discrete-fracture-network) models does not yield a significant improvement in the resolution of geologic-barrier performance. Comparison with seven other less intensively characterised crystalline study sites in Sweden leads to similar results, raising a question as to what extent the geological barrier function can be characterised by state-of-the art site investigation methods prior to repository construction. A simple evaluation provides a simple and robust practical approach for inclusion in performance assessment.

Barriers and strategies for taking medicines in adult patients with renal transplantation.

PubMed

Cedillo-Galindo, H; Gracida, C

2011-11-01

Adherence to the immunosuppressant medications is important for the proper function a renal graft, but there are factors that make this difficult. This study describes strategies and barriers to adequate intake of these medicines based upon 177 surveys in renal transplant patients. Medication adherence was reported to be high (84%), but there were barriers to taking medications (64.95%): the most common were that the pharmacy did not work medicines (28.81%), changes in medication or dose (24.29%), failure to remember (9.6%), and lack of time (6.78%). The most common strategies for taking medications were: the use of cell phone alarms (15.25%) or alarm clocks (9.04%), schedules (5.65%), drug-related meals (5.08%), drug use book (2.26%), and visibility on the table (2.26%). Proper understanding of the barriers to medication adherence and strategies used by recipients may help physicians more adequately educate patients, thereby reducing the risk of rejection related to nonadherence and suggest, specific interventions for improvement. Copyright © 2011 Elsevier Inc. All rights reserved.

Confine Clay in an Alternating Multilayered Structure through Injection Molding: A Simple and Efficient Route to Improve Barrier Performance of Polymeric Materials.

PubMed

Yu, Feilong; Deng, Hua; Bai, Hongwei; Zhang, Qin; Wang, Ke; Chen, Feng; Fu, Qiang

2015-05-20

Various methods have been devoted to trigger the formation of multilayered structure for wide range of applications. These methods are often complicated with low production efficiency or require complex equipment. Herein, we demonstrate a simple and efficient method for the fabrication of polymeric sheets containing multilayered structure with enhanced barrier property through high speed thin-wall injection molding (HSIM). To achieve this, montmorillonite (MMT) is added into PE first, then blended with PP to fabricate PE-MMT/PP ternary composites. It is demonstrated that alternating multilayer structure could be obtained in the ternary composites because of low interfacial tension and good viscosity match between different polymer components. MMT is selectively dispersed in PE phase with partial exfoliated/partial intercalated microstructure. 2D-WAXD analysis indicates that the clay tactoids in PE-MMT/PP exhibits an uniplanar-axial orientation with their surface parallel to the molded part surface, while the tactoids in binary PE-MMT composites with the same overall MMT contents illustrate less orientation. The enhanced orientation of nanoclay in PE-MMT/PP could be attributed to the confinement of alternating multilayer structure, which prohibits the tumbling and rotation of nanoplatelets. Therefore, the oxygen barrier property of PE-MMT/PP is superior to that of PE-MMT because of increased gas permeation pathway. Comparing with the results obtained for PE based composites in literature, outstanding barrier property performance (45.7% and 58.2% improvement with 1.5 and 2.5 wt % MMT content, respectively) is achieved in current study. Two issues are considered responsible for such improvement: enhanced MMT orientation caused by the confinement in layered structure, and higher local density of MMT in layered structure induced denser assembly. Finally, enhancement in barrier property by confining impermeable filler into alternating multilayer structure through such simple and efficient method could provide a novel route toward high-performance packaging materials and other functional materials require layered structure.

A qualitative analysis of information sharing for children with medical complexity within and across health care organizations.

PubMed

Quigley, Laura; Lacombe-Duncan, Ashley; Adams, Sherri; Hepburn, Charlotte Moore; Cohen, Eyal

2014-06-30

Children with medical complexity (CMC) are characterized by substantial family-identified service needs, chronic and severe conditions, functional limitations, and high health care use. Information exchange is critically important in high quality care of complex patients at high risk for poor care coordination. Written care plans for CMC are an excellent test case for how well information sharing is currently occurring. The purpose of this study was to identify the barriers to and facilitators of information sharing for CMC across providers, care settings, and families. A qualitative study design with data analysis informed by a grounded theory approach was utilized. Two independent coders conducted secondary analysis of interviews with parents of CMC and health care professionals involved in the care of CMC, collected from two studies of healthcare service delivery for this population. Additional interviews were conducted with privacy officers of associated organizations to supplement these data. Emerging themes related to barriers and facilitators to information sharing were identified by the two coders and the research team, and a theory of facilitators and barriers to information exchange evolved. Barriers to information sharing were related to one of three major themes; 1) the lack of an integrated, accessible, secure platform on which summative health care information is stored, 2) fragmentation of the current health system, and 3) the lack of consistent policies, standards, and organizational priorities across organizations for information sharing. Facilitators of information sharing were related to improving accessibility to a common document, expanding the use of technology, and improving upon a structured communication plan. Findings informed a model of how various barriers to information sharing interact to prevent optimal information sharing both within and across organizations and how the use of technology to improve communication and access to information can act as a solution.

Schottky-type grain boundaries in CCTO ceramics

NASA Astrophysics Data System (ADS)

Felix, A. A.; Orlandi, M. O.; Varela, J. A.

2011-10-01

In this work we studied electrical barriers existing at CaCu 3Ti 4O 12 (CCTO) ceramics using dc electrical measurements. CCTO pellets were produced by solid state reaction method and X-ray diffractograms showed which single phase polycrystalline samples were obtained. The samples were electrically characterized by dc and ac measurements as a function of temperature, and semiconductor theory was applied to analyze the barrier at grain boundaries. The ac results showed the sample's permittivity is almost constant ( 104) as function of temperature at low frequencies and it changes from 100 to 104 as the temperature increases at high frequencies. Using dc measurements as a function of temperature, the behavior of barriers was studied in detail. Comparison between Schottky and Poole-Frenkel models was performed, and results prove that CCTO barriers are more influenced by temperature than by electric field (Schottky barriers). Besides, the behavior of barrier width as function of temperature was also studied and experimental results confirm the theoretical assumptions.

Barriers to activity and participation for stroke survivors in rural China.

PubMed

Zhang, Lifang; Yan, Tiebin; You, Liming; Li, Kun

2015-07-01

To investigate environmental barriers reported by stroke survivors in the rural areas of China and to determine the impact of environmental barriers on activity and participation relative to demographic characteristics and body functioning. Cross-sectional survey. Structured interviews in the participants' homes. Community-dwelling stroke survivors in the rural areas of China (N=639). Not applicable. Activity and participation (Chinese version of the World Health Organization Disability Assessment Schedule 2.0), environmental barriers (Craig Hospital Inventory of Environmental Factors), neurological function (Canadian Neurological Scale), cognitive function (Abbreviated Mental Test), and depression (6-item Hamilton Rating Scale for Depression). Physical/structural barriers are the major impediment to activity and participation for these participants (odds ratio, 1.86 and 1.99 for activity and participation, respectively; P<.01). Services/assistance barriers primarily impede participation rather than activity (odds ratio, 1.58 in participation; P<.05). Physical/structural and services/assistance barriers were considered the dominant barriers to activity and participation for stroke survivors in the rural areas of China. Attitudinal/support and policy barriers did not emerge as serious concerns. To generate an enabling environment, physical/structural and services/assistance barriers are the environmental barriers to be decreased and eliminated first. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Probiotics promote endocytic allergen degradation in gut epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Chun-Hua; Liu, Zhi-Qiang; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON

Highlights: Black-Right-Pointing-Pointer Knockdown of A20 compromised the epithelial barrier function. Black-Right-Pointing-Pointer The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Black-Right-Pointing-Pointer Antigens transported across A20-deficient HT-29 monolayers conserved antigenicity. Black-Right-Pointing-Pointer Probiotic proteins increased the expression of A20 in HT-29 cells. -- Abstract: Background and aims: Epithelial barrier dysfunction plays a critical role in the pathogenesis of allergic diseases; the mechanism is to be further understood. The ubiquitin E3 ligase A20 (A20) plays a role in the endocytic protein degradation in the cells. This study aims to elucidate the role of A20 in the maintenance of gut epithelial barriermore » function. Methods: Gut epithelial cell line, HT-29 cell, was cultured into monolayers to evaluate the barrier function in transwells. RNA interference was employed to knock down the A20 gene in HT-29 cells to test the role of A20 in the maintenance of epithelial barrier function. Probiotic derived proteins were extracted from the culture supernatants using to enhance the expression of A20 in HT-29 cells. Results: The results showed that the knockdown of A20 compromised the epithelial barrier function in HT-29 monolayers, mainly increased the intracellular permeability. The fusion of endosome/lysosome was disturbed in the A20-deficient HT-29 cells. Allergens collected from the transwell basal chambers of A20-deficient HT-29 monolayers still conserved functional antigenicity. Treating with probiotic derived proteins increased the expression of A20 in HT-29 cells and promote the barrier function. Conclusion: A20 plays an important role in the maintenance of epithelial barrier function as shown by HT-29 monolayer. Probiotic derived protein increases the expression of A20 and promote the HT-29 monolayer barrier function.« less

Concise Review: Tissue-Engineered Skin and Nerve Regeneration in Burn Treatment

PubMed Central

Blais, Mathieu; Parenteau-Bareil, Rémi; Cadau, Sébastien

2013-01-01

Burns not only destroy the barrier function of the skin but also alter the perceptions of pain, temperature, and touch. Different strategies have been developed over the years to cover deep and extensive burns with the ultimate goal of regenerating the barrier function of the epidermis while recovering an acceptable aesthetic aspect. However, patients often complain about a loss of skin sensation and even cutaneous chronic pain. Cutaneous nerve regeneration can occur from the nerve endings of the wound bed, but it is often compromised by scar formation or anarchic wound healing. Restoration of pain, temperature, and touch perceptions should now be a major challenge to solve in order to improve patients' quality of life. In addition, the cutaneous nerve network has been recently highlighted to play an important role in epidermal homeostasis and may be essential at least in the early phase of wound healing through the induction of neurogenic inflammation. Although the nerve regeneration process was studied largely in the context of nerve transections, very few studies have been aimed at developing strategies to improve it in the context of cutaneous wound healing. In this concise review, we provide a description of the characteristics of and current treatments for extensive burns, including tissue-engineered skin approaches to improve cutaneous nerve regeneration, and describe prospective uses for autologous skin-derived adult stem cells to enhance recovery of the skin's sense of touch. PMID:23734060

The improvement in functional characteristics of eco-friendly composites made of natural rubber and cellulose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araki, Kunihiro; Kaneko, Shonosuke; Matsumoto, Koki

We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. In order to further improvement of functional characteristics, epoxidized natural rubber (ENR) was also used instead of NR. The FSCP were produced by mechanical milling in a planetary ball mill with a grinding aid as a cellulose aggregation inhibitor. Moreover, talc and mica particles were used to compare with FSCP. NR and ENR was mixed with vulcanizing agents and thenmore » each filler was added to NR compound in an internal mixer. The vulcanizing agents are as follows: stearic acid, zinc oxide, sulfur, and vulcanization accelerator. The functionalities of the composites were evaluated by a vibration-damping experiment and a gas permeability experiment. As a result, we found that FSCP filler has effects similar to (or more than) inorganic filler in vibration-damping and O{sub 2} barrier properties. And then, vibration- damping and O{sub 2} barrier properties of the composite including FSCP was increased with use of ENR. In particular, we found that ENR-50 composite containing 50 phr FSCP has three times as high vibration-damping property as ENR-50 without FSCP.« less

Using Free Internet Videogames in Upper Extremity Motor Training for Children with Cerebral Palsy

PubMed Central

Sevick, Marisa; Eklund, Elizabeth; Mensch, Allison; Foreman, Matthew; Standeven, John; Engsberg, Jack

2016-01-01

Movement therapy is one type of upper extremity intervention for children with cerebral palsy (CP) to improve function. It requires high-intensity, repetitive and task-specific training. Tedium and lack of motivation are substantial barriers to completing the training. An approach to overcome these barriers is to couple the movement therapy with videogames. This investigation: (1) tested the feasibility of delivering a free Internet videogame upper extremity motor intervention to four children with CP (aged 8–17 years) with mild to moderate limitations to upper limb function; and (2) determined the level of intrinsic motivation during the intervention. The intervention used free Internet videogames in conjunction with the Microsoft Kinect motion sensor and the Flexible Action and Articulated Skeleton Toolkit software (FAAST) software. Results indicated that the intervention could be successfully delivered in the laboratory and the home, and pre- and post- impairment, function and performance assessments were possible. Results also indicated a high level of motivation among the participants. It was concluded that the use of inexpensive hardware and software in conjunction with free Internet videogames has the potential to be very motivating in helping to improve the upper extremity abilities of children with CP. Future work should include results from additional participants and from a control group in a randomized controlled trial to establish efficacy. PMID:27338485

Functions of an engineered barrier system for a nuclear waste repository in basalt

NASA Astrophysics Data System (ADS)

Coons, W. E.; Moore, E. L.; Smith, M. J.; Kaser, J. D.

1980-01-01

The functions of components selected for an engineered barrier system for a nuclear waste repository in basalt are defined providing a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed. Redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed.

Barriers to Implementation of Optimal Laboratory Biosafety Practices in Pakistan

PubMed Central

Shafaq, Humaira; Hasan, Rumina; Qureshi, Shahida M.; Dojki, Maqboola; Hughes, Molly A.; Zaidi, Anita K. M.; Khan, Erum

2016-01-01

The primary goal of biosafety education is to ensure safe practices among workers in biomedical laboratories. Despite several educational workshops by the Pakistan Biological Safety Association (PBSA), compliance with safe practices among laboratory workers remains low. To determine barriers to implementation of recommended biosafety practices among biomedical laboratory workers in Pakistan, we conducted a questionnaire-based survey of participants attending 2 workshops focusing on biosafety practices in Karachi and Lahore in February 2015. Questionnaires were developed by modifying the BARRIERS scale in which respondents are required to rate barriers on a 1-4 scale. Nineteen of the original 29 barriers were included and subcategorized into 4 groups: awareness, material quality, presentation, and workplace barriers. Workshops were attended by 64 participants. Among barriers that were rated as moderate to great barriers by at least 50% of respondents were: lack of time to read biosafety guidelines (workplace subscale), lack of staff authorization to change/improve practice (workplace subscale), no career or self-improvement advantages to the staff for implementing optimal practices (workplace subscale), and unclear practice implications (presentation subscale). A lack of recognition for employees' rights and benefits in the workplace was found to be a predominant reason for a lack of compliance. Based on perceived barriers, substantial improvement in work environment, worker facilitation, and enabling are needed for achieving improved or optimal biosafety practices in Pakistan. PMID:27400192

The Cementitious Barriers Partnership (CBP) Software Toolbox Capabilities in Assessing the Degradation of Cementitious Barriers - 13487

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flach, G.P.; Burns, H.H.; Langton, C.

2013-07-01

The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the U.S. Department of Energy (US DOE) Office of Tank Waste and Nuclear Materials Management. The CBP program has developed a set of integrated tools (based on state-of-the-art models and leaching test methods) that help improve understanding and predictions of the long-term structural, hydraulic and chemical performance of cementitious barriers used in nuclear applications. Tools selected for and developed under this program have been used to evaluate and predict the behavior of cementitious barriers used in near-surface engineered waste disposal systems for periods of performance up tomore » 100 years and longer for operating facilities and longer than 1000 years for waste disposal. The CBP Software Toolbox has produced tangible benefits to the DOE Performance Assessment (PA) community. A review of prior DOE PAs has provided a list of potential opportunities for improving cementitious barrier performance predictions through the use of the CBP software tools. These opportunities include: 1) impact of atmospheric exposure to concrete and grout before closure, such as accelerated slag and Tc-99 oxidation, 2) prediction of changes in K{sub d}/mobility as a function of time that result from changing pH and redox conditions, 3) concrete degradation from rebar corrosion due to carbonation, 4) early age cracking from drying and/or thermal shrinkage and 5) degradation due to sulfate attack. The CBP has already had opportunity to provide near-term, tangible support to ongoing DOE-EM PAs such as the Savannah River Saltstone Disposal Facility (SDF) by providing a sulfate attack analysis that predicts the extent and damage that sulfate ingress will have on the concrete vaults over extended time (i.e., > 1000 years). This analysis is one of the many technical opportunities in cementitious barrier performance that can be addressed by the DOE-EM sponsored CBP software tools. Modification of the existing tools can provide many opportunities to bring defense in depth in prediction of the performance of cementitious barriers over time. (authors)« less

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

PubMed Central

Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

2012-01-01

AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). CONCLUSION: L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice.

PubMed

Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

2012-08-14

To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

Evaluation of confocal laser endomicroscopy for assessment and monitoring of therapeutic response in patients with inflammatory bowel disease.

PubMed

Karstensen, John Gásdal

2016-11-01

Crohn's disease (CD) and ulcerative colitis (UC) have been associated with altered intestinal barrier function. Moreover, it has been proposed that a defective barrier function is related to risk of relapse in patients with quiescent CD. Fluorescein-aided confocal laser endomicroscopy (CLE) is a novel endoscopic method, which enables real-time in vivo microscopy. Hence, the intestinal barrier function can be assessed as part of endoscopic evaluation of patients with inflammatory bowel disease (IBD) by measuring microerosions and fluorescein leakage into the intestinal lumen. Furthermore, barrier dysfunction can be correlated with biomarkers associated with intestinal barrier impairments. E-cadherin is a key factor for the adherence of epithelial cells and Smad4 is a cofactor in TGF-β signalling, which is compromised in IBD. To correlate ileal and colonic CLE parameters with endoscopy and histopathology in IBD. Further, we wanted to correlate these features with risk of relapse and evaluate whether they were reproducible and reversible after intensified medical treatment. We also wanted to analyse, whether Smad4 and E-cadherin mucosal protein expression levels were associated with impairments of intestinal barrier function. CLE was performed and correlated to histopathology and endoscopic appearance in two prospective studies in CD (n = 39, controls = 11) and UC patients (n = 22, controls = 7), respectively. In the first study, results were correlated to risk of relapse, whereas the latter assessed the reversibility of CLE features in a longitudinal setting. κ-statistics were used in both studies to assess reproducibility of the CLE findings. Furthermore, ileal biopsy specimens from CD patients and controls were stained by immunohistochemistry for Smad4 and E-cadherin and subsequently correlated to the severity of CD and intestinal barrier impairments. We found that fluorescein leakage and microerosions in the terminal ileum were significantly associated with CD com-pared to controls (p = 0.005 and p = 0.006, respectively) and that ileal fluorescein leakage and microerosions could predict relapse (log-rank p = 0.003 and p = 0.017, respectively). In UC patients with clinical relapse, an augmented crypt architecture and colonic fluorescein leakage were significantly correlated to the severity of the disease (p = 0.001 and p < 0.001, respectively). After intensified medical treatment, a correlation was found between histopathological progress and improvement of abnormal colonic crypt architecture (rs = 0.35, p = 0.016), but we did not observe a resolution of the intestinal barrier dysfunction (rs = 0.09, p = 0.56). The inter-observer variability of CLE parameters ranged from fair to substantial, while the intra-observer variability was somewhat higher. Smad4 expression (rs = 0.56, p = 0.002), but not E-cadherin (rs = 0.01, p = 0.95), was correlated with the severity of the disease; however, Smad4 expression did not correlate with a defect barrier function. CLE can visualise crypt alteration and barrier impairments in both CD and UC, which are otherwise undetectable. Further studies are warranted to incorporate CLE in the endoscopic and therapeutic management algorithm for CD and UC possibly refining the definition of mucosal healing. Smad4 expression was correlated with CD as well as disease severity and may serve as a novel treatment target.

The effects of cholesterol on learning and memory.

PubMed

Schreurs, Bernard G

2010-07-01

Cholesterol is vital to normal brain function including learning and memory but that involvement is as complex as the synthesis, metabolism and excretion of cholesterol itself. Dietary cholesterol influences learning tasks from water maze to fear conditioning even though cholesterol does not cross the blood brain barrier. Excess cholesterol has many consequences including peripheral pathology that can signal brain via cholesterol metabolites, pro-inflammatory mediators and antioxidant processes. Manipulations of cholesterol within the central nervous system through genetic, pharmacological, or metabolic means circumvent the blood brain barrier and affect learning and memory but often in animals already otherwise compromised. The human literature is no less complex. Cholesterol reduction using statins improves memory in some cases but not others. There is also controversy over statin use to alleviate memory problems in Alzheimer's disease. Correlations of cholesterol and cognitive function are mixed and association studies find some genetic polymorphisms are related to cognitive function but others are not. In sum, the field is in flux with a number of seemingly contradictory results and many complexities. Nevertheless, understanding cholesterol effects on learning and memory is too important to ignore.

The Roles of Vitamin C in Skin Health.

PubMed

Pullar, Juliet M; Carr, Anitra C; Vissers, Margreet C M

2017-08-12

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.

Description of an α-cluster tail in 8Be and 20Ne: Delocalization of the α cluster by quantum penetration

NASA Astrophysics Data System (ADS)

Kanada-En'yo, Yoshiko

2014-10-01

We analyze the α-cluster wave functions in cluster states of ^8Be and ^{20}Ne by comparing the exact relative wave function obtained by the generator coordinate method (GCM) with various types of trial functions. For the trial functions, we adopt the fixed range shifted Gaussian of the Brink-Bloch (BB) wave function, the spherical Gaussian with the adjustable range parameter of the spherical Tohsaki-Horiuchi-Schuck-Röpke (sTHSR), the deformed Gaussian of the deformed THSR (dTHSR), and a function with the Yukawa tail (YT). The quality of the description of the exact wave function with a trial function is judged by the squared overlap between the trial function and the GCM wave function. A better result is obtained with the sTHSR wave function than the BB wave function, and further improvement can be made with the dTHSR wave function because these wave functions can describe the outer tail better. The YT wave function gives almost an equal quality to or even better quality than the dTHSR wave function, indicating that the outer tail of α-cluster states is characterized by the Yukawa-like tail rather than the Gaussian tail. In weakly bound α-cluster states with small α separation energy and the low centrifugal and Coulomb barriers, the outer tail part is the slowly damping function described well by the quantum penetration through the effective barrier. This outer tail characterizes the almost zero-energy free α gas behavior, i.e., the delocalization of the cluster.

Evolution of Islet Transplantation for the Last 30 Years.

PubMed

Farney, Alan C; Sutherland, David E R; Opara, Emmanuel C

2016-01-01

In this article, we will review the changes that have occurred in islet transplantation at the birth of Pancreas 30 years ago. The first attempts at β-cell replacement in humans, pancreas and islet transplantation, were performed in the 1960s and 1970s. Although pancreas transplantation has been an accepted treatment for severe labile diabetes predating the emergence of the journal, allogeneic islet transplantation remains experimental. Current investigations within islet transplantation focus to improve islet function after transplantation. Improving islet viability during isolation, exploring ways to increase engraftment, and protection from the host immune system are some of the goals of these investigative efforts. The major barriers to clinical islet transplantation are shortage of human pancreas, the need for immunosuppression, and the inadequacy of the islet isolation process. It is generally accepted that islet encapsulation is an immunoisolation tool with good potential to address the first 2 of those barriers. We have therefore devoted a major part of this review to the critical factors needed to make it a clinical reality. With improved islet isolation techniques and determination of the best site of engraftment as well as improved encapsulation techniques, we hope that islet transplantation could someday achieve routine clinical use.

Multidimensionally constrained relativistic mean-field study of triple-humped barriers in actinides

NASA Astrophysics Data System (ADS)

Zhao, Jie; Lu, Bing-Nan; Vretenar, Dario; Zhao, En-Guang; Zhou, Shan-Gui

2015-01-01

Background: Potential energy surfaces (PES's) of actinide nuclei are characterized by a two-humped barrier structure. At large deformations beyond the second barrier, the occurrence of a third barrier was predicted by macroscopic-microscopic model calculations in the 1970s, but contradictory results were later reported by a number of studies that used different methods. Purpose: Triple-humped barriers in actinide nuclei are investigated in the framework of covariant density functional theory (CDFT). Methods: Calculations are performed using the multidimensionally constrained relativistic mean field (MDC-RMF) model, with the nonlinear point-coupling functional PC-PK1 and the density-dependent meson exchange functional DD-ME2 in the particle-hole channel. Pairing correlations are treated in the BCS approximation with a separable pairing force of finite range. Results: Two-dimensional PES's of 226,228,230,232Th and 232,235,236,238U are mapped and the third minima on these surfaces are located. Then one-dimensional potential energy curves along the fission path are analyzed in detail and the energies of the second barrier, the third minimum, and the third barrier are determined. The functional DD-ME2 predicts the occurrence of a third barrier in all Th nuclei and 238U . The third minima in 230 ,232Th are very shallow, whereas those in 226 ,228Th and 238U are quite prominent. With the functional PC-PK1 a third barrier is found only in 226 ,228 ,230Th . Single-nucleon levels around the Fermi surface are analyzed in 226Th, and it is found that the formation of the third minimum is mainly due to the Z =90 proton energy gap at β20≈1.5 and β30≈0.7 . Conclusions: The possible occurrence of a third barrier on the PES's of actinide nuclei depends on the effective interaction used in multidimensional CDFT calculations. More pronounced minima are predicted by the DD-ME2 functional, as compared to the functional PC-PK1. The depth of the third well in Th isotopes decreases with increasing neutron number. The origin of the third minimum is due to the proton Z =90 shell gap at relevant deformations.

The Drosophila blood-brain barrier: development and function of a glial endothelium.

PubMed

Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

2014-01-01

The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells.

Equity and immunization supply chain in Madagascar.

PubMed

van den Ent, Maya M V X; Yameogo, Andre; Ribaira, Eric; Hanson, Celina M; Ratoto, Ramiandrasoa; Rasolomanana, Saholy; Foncha, Chrysanthus; Gasse, François

2017-04-19

Vaccination rates have improved in many countries, yet immunization inequities persist within countries and the poorest communities often bear the largest burden of vaccine preventable disease. Madagascar has one of the world's largest equity gaps in immunization rates. Barriers to immunization include immunization supply chain, human resources, and service delivery to reflect the health system building blocks, which affect poor rural communities more than affluent communities. The Reaching Every District (RED) approach was revised to address barriers and bottlenecks. This approach focuses on the provision of regular services, including making cold chain functional. This report describes Madagascar's inequities in immunization, its programmatic causes and the country's plans to address barriers to immunization in the poorest regions in the country. Two cross-sectional health facility surveys conducted in November and December 2013 and in March 2015 were performed in four regions of Madagascar to quantify immunization system barriers. Of the four regions studied, 26-33% of the population live beyond 5km (km) of a health center. By 2015, acceptable (fridges stopped working for less than 6days) cold chains were found in 52-80% of health facilities. Only 10-57% of health centers had at least two qualified health workers. Between 65% and 95% of planned fixed vaccination sessions were conducted and 50-88% of planned outreach sessions were conducted. The proportion of planned outreach sessions that were conducted increased between the two surveys. Madagascar's immunization program faces serious challenges and those affected most are the poorest populations. Major inequities in immunization were found at the subnational level and were mainly geographic in nature. Approaches to improve immunization systems need to be equitable. This may include the replacement of supply chain equipment with those powered by sustainable energy sources, monitoring its functionality at health facility level and vaccination services in all communities. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Qualitative assessment of Diabetes-STAR: a patient portal with disease management functions.

PubMed

Ross, Stephen E; Nowels, Carolyn T; Haverhals, Leah M; Bull, Sheana S; Lin, Chen-Tan; Main, Deborah S

2007-10-11

Diabetes-STAR is a disease management program integrated with an online patient portal. Of 331 patients enrolled in a randomized trial, we interviewed 37 users about benefits, barriers and recommendations for program improvements. User preferences included 1) addressing differences in types of users, 2) sending out alerts when new information is available, and 3) providing more oversight of user diary data.

Helminths and Intestinal Flora Team Up to Improve Gut Health.

PubMed

Giacomin, Paul; Agha, Zainab; Loukas, Alex

2016-09-01

Inflammatory bowel diseases (IBD) are associated with impaired intestinal barrier function, chronic inflammation, and microbial dysbiosis. In a recent publication in Science, Ramanan et al. used murine and human studies to demonstrate that infections with gastrointestinal helminths can protect against IBD by provoking immune responses that alter the balance of commensal and pathogenic bacteria in the intestine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Participants' barriers to diagnostic resolution and factors associated with needing patient navigation.

PubMed

Krok-Schoen, Jessica L; Brewer, Brittany M; Young, Gregory S; Weier, Rory C; Tatum, Cathy M; DeGraffinreid, Cecilia R; Paskett, Electra D

2015-08-15

Patient navigation (PN) may improve cancer care by identifying and removing patient-reported barriers to care. In 2012, the American College of Surgeons Commission on Cancer (CoC) announced that health care facilities seeking CoC accreditation must have PN processes in place by January 1, 2015. Given these unfunded mandates, hospitals are looking for cost-effective ways to implement PN. This study examined demographic and psychosocial predictors of barriers to diagnostic resolution among individuals with a cancer screening abnormality enrolled in the Ohio Patient Navigation Research Project. Data were obtained from patients who received care at 1 of 9 Ohio Patient Navigation Research Project intervention clinics. Descriptive statistics and logistic regression models were used. There were 424 participants, and 151 (35.6%) reported a barrier to diagnostic resolution within 90 days of study consent. The most commonly reported barriers were misconceptions about a test or treatment (16.4%), difficulty in communicating with the provider (15.0%), and scheduling problems (11.5%). Univariate analyses indicated that race, education, employment, income, insurance, clinic type, friend support, and physical and psychological functioning were significantly associated with reporting a barrier to diagnostic resolution. Multivariate analyses found that comorbidities (odds ratio, 1.65; 95% confidence interval, 1.04-2.61) and higher intrusive thoughts and feelings (odds ratio, 1.25; 95% confidence interval, 1.10-1.41) were significantly associated with reporting a barrier to diagnostic resolution. The results suggest that demographic and psychosocial factors are associated with barriers to diagnostic resolution. To ensure compliance with the CoC mandate and provide timely care to all patients, CoC-accredited facilities can systematically identify the patients most likely to have barriers to care and assign them to PN. © 2015 American Cancer Society.

Multi-functional electrospun antibacterial core-shell nanofibrous membranes for prolonged prevention of post-surgical tendon adhesion and inflammation.

PubMed

Shalumon, K T; Sheu, Chialin; Chen, Chih-Hao; Chen, Shih-Heng; Jose, Gils; Kuo, Chang-Yi; Chen, Jyh-Ping

2018-05-01

The possibility of endowing an electrospun anti-adhesive barrier membrane with multi-functionality, such as lubrication, prevention of fibroblast attachment and anti-infection and anti-inflammation properties, is highly desirable for the management of post-surgical tendon adhesion. To this end, we fabricated core-shell nanofibrous membranes (CSNMs) with embedded silver nanoparticles (Ag NPs) in the poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) shell and hyaluronic acid (HA)/ibuprofen in the core. HA imparted a lubrication effect for smooth tendon gliding and reduced fibroblast attachment, while Ag NPs and ibuprofen functioned as anti-infection and anti-inflammation agents, respectively. CSNMs with a PEG/PCL/Ag shell (PPA) and HA core containing 0% (H/PPA), 10% (HI10/PPA), 30% (HI30/PPA) and 50% (HI50/PPA) ibuprofen were fabricated through co-axial electrospinning and assessed through microscopic, spectroscopic, thermal, mechanical and drug release analyses. Considering nutrient passage through the barrier, the microporous CSNMs exerted the same barrier effect but drastically increased the mass transfer coefficients of bovine serum albumin compared with the commercial anti-adhesive membrane SurgiWrap®. Cell attachment/focal adhesion formation of fibroblasts revealed effective reduction of initial cell attachment on the CSNM surface with minimum cytotoxicity (except HI50/PPA). The anti-bacterial effect against both Gram-negative and Gram-positive bacteria was verified to be due to the Ag NPs in the membranes. In vivo studies using H/PPA and HI30/PPA CSNMs and SurgiWrap® in a rabbit flexor tendon rupture model demonstrated the improved efficacy of HI30/PPA CSNMs in reducing inflammation and tendon adhesion formation based on gross observation, histological analysis and functional assays. We conclude that HI30/PPA CSNMs can act as a multifunctional barrier membrane to prevent peritendinous adhesion after tendon surgery. A multi-functional anti-adhesion barrier membrane that could reduce fibroblasts attachment and penetration while simultaneously prevent post-surgical infection and inflammation is urgently needed. To this end, we prepared electrospun core-shell hyaluronic acid + ibuprofen/polyethylene glycol + polycaprolactone + Ag nanoparticles nanofibrous membranes by co-axial electrospinning as an ideal anti-adhesive membrane. The core-shell structure could meet the need of a desirable anti-adhesion barrier through release of ibuprofen and Ag nanoparticles to reduce infection and inflammation while hyaluronic acid can reduce fibroblasts adhesion. The superior performance of this multi-functional core-shell nanofibrous membrane in preventing peritendinous adhesion and post-surgical inflammation was demonstrated in a rabbit flexor tendon rupture model. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Phosphonic acid functionalization of nanostructured Ni-W coatings on steel

NASA Astrophysics Data System (ADS)

Orrillo, P. A.; Ribotta, S. B.; Gassa, L. M.; Benítez, G.; Salvarezza, R. C.; Vela, M. E.

2018-03-01

The functionalization of nanocrystalline Ni-W coatings, formed by galvanostatic pulsed electrodeposition on steel, by thermal treatment of octadecylphosphonic acid self-assembled on the oxidized alloy surface is studied by Raman spectroscopy, contact angle measurements, X-ray photoelectron spectroscopy, AFM and electrochemical techniques. Results show that this procedure preserves the surface topography and the optimum mechanical properties of the alloy. More importantly, it turns the alloy surface highly hydrophobic and markedly improves its corrosion resistance, in particular to pitting corrosion in aggressive solutions containing chloride anions. The ability of the phosphonate layer to improve surface properties arises from the barrier properties introduced by the hydrocarbon chains and the strong bonds between the phosphonate head and the underlying surface oxides.

Sensitive skin at menopause; dew point and electrometric properties of the stratum corneum.

PubMed

Paquet, F; Piérard-Franchimont, C; Fumal, I; Goffin, V; Paye, M; Piérard, G E

1998-01-12

A number of menopausal women experience skin sensitive to various environmental threats. Two panels of 15 menopausal women on or without HRT were compared. We studied the response of their stratum corneum to variations in environmental humidity, either in air or in response to an emollient. Environment dew point and electrometric measurements on the skin were recorded to search for correlations. Data show that the baseline stratum corneum hydration is influenced by the dew point. HRT improves the barrier function of the skin. The use of emollient further extends the improvement in the functional properties of skin in menopausal women. Both HRT and an emollient can counteract in part some of the deleterious effects of cold and dry weather.

Nutrition: A Primary Therapy in Pediatric Acute Respiratory Distress Syndrome

PubMed Central

Wilson, Bryan; Typpo, Katri

2016-01-01

Appropriate nutrition is an essential component of intensive care management of children with acute respiratory distress syndrome (ARDS) and is linked to patient outcomes. One out of every two children in the pediatric intensive care unit (PICU) will develop malnutrition or have worsening of baseline malnutrition and present with specific micronutrient deficiencies. Early and adequate enteral nutrition (EN) is associated with improved 60-day survival after pediatric critical illness, and, yet, despite early EN guidelines, critically ill children receive on average only 55% of goal calories by PICU day 10. Inadequate delivery of EN is due to perceived feeding intolerance, reluctance to enterally feed children with hemodynamic instability, and fluid restriction. Underlying each of these factors is large practice variation between providers and across institutions for initiation, advancement, and maintenance of EN. Strategies to improve early initiation and advancement and to maintain delivery of EN are needed to improve morbidity and mortality from pediatric ARDS. Both, over and underfeeding, prolong duration of mechanical ventilation in children and worsen other organ function such that precise calorie goals are needed. The gut is thought to act as a “motor” of organ dysfunction, and emerging data regarding the role of intestinal barrier functions and the intestinal microbiome on organ dysfunction and outcomes of critical illness present exciting opportunities to improve patient outcomes. Nutrition should be considered a primary rather than supportive therapy for pediatric ARDS. Precise nutritional therapies, which are titrated and targeted to preservation of intestinal barrier function, prevention of intestinal dysbiosis, preservation of lean body mass, and blunting of the systemic inflammatory response, offer great potential for improving outcomes of pediatric ARDS. In this review, we examine the current evidence regarding dose, route, and timing of nutrition, current recommendations for provision of nutrition to children with ARDS, and the current literature for immune-modulating diets for pediatric ARDS. We will examine emerging data regarding the role of the intestinal microbiome in modulating the response to critical illness. PMID:27790606

The Development of Erosion and Impact Resistant Turbine Airfoil Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2007-01-01

Thermal barrier coatings are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments and extend component lifetimes. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Advanced erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the doped thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion and impact damage mechanisms of the thermal barrier coatings will also be discussed.

Effects of Fe particle irradiation on human endothelial barrier structure and function

NASA Astrophysics Data System (ADS)

Sharma, Preety; Guida, Peter; Grabham, Peter

2014-07-01

Space travel involves exposure to biologically effective heavy ion radiation and there is consequently a concern for possible degenerative disorders in humans. A significant target for radiation effects is the microvascular system, which is crucial to healthy functioning of the tissues. Its pathology is linked to disrupted endothelial barrier function and is not only a primary event in a range of degenerative diseases but also an important influencing factor in many others. Thus, an assessment of the effects of heavy ion radiation on endothelial barrier function would be useful for estimating the risks of space travel. This study was aimed at understanding the effects of high LET Fe particles (1 GeV/n) and is the first investigation of the effects of charged particles on the function of the human endothelial barrier. We used a set of established and novel endpoints to assess barrier function after exposure. These include, trans-endothelial electrical resistance (TEER), morphological effects, localization of adhesion and cell junction proteins (in 2D monolayers and in 3D tissue models), and permeability of molecules through the endothelial barrier. A dose of 0.50 Gy was sufficient to cause a progressive reduction in TEER measurements that were significant 48 hours after exposure. Concurrently, there were morphological changes and a 14% loss of cells from monolayers. Gaps also appeared in the normally continuous cell-border localization of the tight junction protein - ZO-1 but not the Platelet endothelial cell adhesion molecule (PECAM-1) in both monolayers and in 3D vessel models. Disruption of barrier function was confirmed by increased permeability to 3 kDa and 10 kDa dextran molecules. A dose of 0.25 Gy caused no detectible change in cell number, morphology, or TEER, but did cause barrier disruption since there were gaps in the cell border localization of ZO-1 and an increased permeability to 3 kDa dextran. These results indicate that Fe particles potently have impact on human endothelial barrier function and represent a risk for degenerative diseases in the space environment.

Apoplastic Diffusion Barriers in Arabidopsis

PubMed Central

Schreiber, Lukas; Franke, Rochus Benni; Geldner, Niko; Reina-Pinto, José J.; Kunst, Ljerka

2013-01-01

During the development of Arabidopsis and other land plants, diffusion barriers are formed in the apoplast of specialized tissues within a variety of plant organs. While the cuticle of the epidermis is the primary diffusion barrier in the shoot, the Casparian strips and suberin lamellae of the endodermis and the periderm represent the diffusion barriers in the root. Different classes of molecules contribute to the formation of extracellular diffusion barriers in an organ- and tissue-specific manner. Cutin and wax are the major components of the cuticle, lignin forms the early Casparian strip, and suberin is deposited in the stage II endodermis and the periderm. The current status of our understanding of the relationships between the chemical structure, ultrastructure and physiological functions of plant diffusion barriers is discussed. Specific aspects of the synthesis of diffusion barrier components and protocols that can be used for the assessment of barrier function and important barrier properties are also presented. PMID:24465172

A fast method to produce strong NFC films as a platform for barrier and functional materials.

PubMed

Osterberg, Monika; Vartiainen, Jari; Lucenius, Jessica; Hippi, Ulla; Seppälä, Jukka; Serimaa, Ritva; Laine, Janne

2013-06-12

In this study, we present a rapid method to prepare robust, solvent-resistant, nanofibrillated cellulose (NFC) films that can be further surface-modified for functionality. The oxygen, water vapor, and grease barrier properties of the films were measured, and in addition, mechanical properties in the dry and wet state and solvent resistance were evaluated. The pure unmodified NFC films were good barriers for oxygen gas and grease. At a relative humidity below 65%, oxygen permeability of the pure and unmodified NFC films was below 0.6 cm(3) μm m(-2) d(-1) kPa(-1), and no grease penetrated the film. However, the largest advantage of these films was their resistance to various solvents, such as water, methanol, toluene, and dimethylacetamide. Although they absorbed a substantial amount of solvent, the films could still be handled after 24 h of solvent soaking. Hot-pressing was introduced as a convenient method to not only increase the drying speed of the films but also enhance the robustness of the films. The wet strength of the films increased due to the pressing. Thus, they can be chemically or physically modified through adsorption or direct chemical reaction in both aqueous and organic solvents. Through these modifications, the properties of the film can be enhanced, introducing, for example, functionality, hydrophobicity, or bioactivity. Herein, a simple method using surface coating with wax to improve hydrophobicity and oxygen barrier properties at very high humidity is described. Through this modification, the oxygen permeability decreased further and was below 17 cm(3) μm m(-2) d(-1) kPa(-1) even at 97.4% RH, and the water vapor transmission rate decreased from 600 to 40 g/m(2) day. The wax treatment did not deteriorate the dry strength of the film. Possible reasons for the unique properties are discussed. The developed robust NFC films can be used as a generic, environmentally sustainable platform for functional materials.

Contrasting effects of linaclotide and lubiprostone on restitution of epithelial cell barrier properties and cellular homeostasis after exposure to cell stressors

PubMed Central

2012-01-01

Background Linaclotide has been proposed as a treatment for the same gastrointestinal indications for which lubiprostone has been approved, chronic idiopathic constipation and irritable bowel syndrome with constipation. Stressors damage the epithelial cell barrier and cellular homeostasis leading to loss of these functions. Effects of active linaclotide on repair of barrier and cell function in pig jejunum after ischemia and in T84 cells after treatment with proinflammatory cytokines, interferon-γ and tumor necrosis factor-α were examined. Comparison with effects of lubiprostone, known to promote repair of barrier function was carried out. Results In ischemia-damaged pig jejunum, using measurements of transepithelial resistance, 3H-mannitol fluxes, short-circuit current (Cl− secretion) and occludin localization, active linaclotide failed to effectively promote repair of the epithelial barrier or recovery of short-circuit current, whereas lubiprostone promoted barrier repair and increased short-circuit current. In control pig jejunum, 1 μM linaclotide and 1 μM lubiprostone both caused similar increases in short-circuit current (Cl− secretion). In T84 cells, using measurements of transepithelial resistance, fluxes of fluorescent macromolecules, occludin and mitochondrial membrane potential, active linaclotide was virtually ineffective against damage caused by interferon-γ and tumor necrosis factor-α, while lubiprostone protected or promoted repair of epithelial barrier and cell function. Barrier protection/repair by lubiprostone was inhibited by methadone, a ClC-2 inhibitor. Linaclotide, but not lubiprostone increased [cGMP]i as expected and [Ca2+]i and linaclotide depolarized while lubiprostone hyperpolarized the T84 plasma membrane potential suggesting that lubiprostone may lead to greater cellular stability compared to linaclotide. In T84 cells, as found with linaclotide but not with lubiprostone, transepithelial resistance was slightly but significantly decreased by guanylin, STa and 8-bromo cGMP and fluorescent dextran fluxes were increased by guanylin. However the physiological implications of these small but statistically significant changes remain unclear. Conclusions Considering the physiological importance of epithelial barrier function and cell integrity and the known impact of stressors, the finding that lubiprostone, but not active linaclotide, exhibits the additional distinct property of effective protection or repair of the epithelial barrier and cell function after stress suggests potential clinical importance for patients with impaired or compromised barrier function such as might occur in IBS. PMID:22553939

Contrasting effects of linaclotide and lubiprostone on restitution of epithelial cell barrier properties and cellular homeostasis after exposure to cell stressors.

PubMed

Cuppoletti, John; Blikslager, Anthony T; Chakrabarti, Jayati; Nighot, Prashant K; Malinowska, Danuta H

2012-05-03

Linaclotide has been proposed as a treatment for the same gastrointestinal indications for which lubiprostone has been approved, chronic idiopathic constipation and irritable bowel syndrome with constipation. Stressors damage the epithelial cell barrier and cellular homeostasis leading to loss of these functions. Effects of active linaclotide on repair of barrier and cell function in pig jejunum after ischemia and in T84 cells after treatment with proinflammatory cytokines, interferon-γ and tumor necrosis factor-α were examined. Comparison with effects of lubiprostone, known to promote repair of barrier function was carried out. In ischemia-damaged pig jejunum, using measurements of transepithelial resistance, (3)H-mannitol fluxes, short-circuit current (Cl(-) secretion) and occludin localization, active linaclotide failed to effectively promote repair of the epithelial barrier or recovery of short-circuit current, whereas lubiprostone promoted barrier repair and increased short-circuit current. In control pig jejunum, 1 μM linaclotide and 1 μM lubiprostone both caused similar increases in short-circuit current (Cl(-) secretion). In T84 cells, using measurements of transepithelial resistance, fluxes of fluorescent macromolecules, occludin and mitochondrial membrane potential, active linaclotide was virtually ineffective against damage caused by interferon-γ and tumor necrosis factor-α, while lubiprostone protected or promoted repair of epithelial barrier and cell function. Barrier protection/repair by lubiprostone was inhibited by methadone, a ClC-2 inhibitor. Linaclotide, but not lubiprostone increased [cGMP]i as expected and [Ca(2+)]i and linaclotide depolarized while lubiprostone hyperpolarized the T84 plasma membrane potential suggesting that lubiprostone may lead to greater cellular stability compared to linaclotide. In T84 cells, as found with linaclotide but not with lubiprostone, transepithelial resistance was slightly but significantly decreased by guanylin, STa and 8-bromo cGMP and fluorescent dextran fluxes were increased by guanylin. However the physiological implications of these small but statistically significant changes remain unclear. Considering the physiological importance of epithelial barrier function and cell integrity and the known impact of stressors, the finding that lubiprostone, but not active linaclotide, exhibits the additional distinct property of effective protection or repair of the epithelial barrier and cell function after stress suggests potential clinical importance for patients with impaired or compromised barrier function such as might occur in IBS.

Implementing a 6-day physiotherapy service in rehabilitation: exploring staff perceptions.

PubMed

Caruana, Erin L; Kuys, Suzanne S; Clarke, Jane; Brauer, Sandra G

2017-11-20

Objective Australian weekend rehabilitation therapy provision is increasing. Staff engagement optimises service delivery. The present mixed-methods process evaluation explored staff perceptions regarding implementation of a 6-day physiotherapy service in a private rehabilitation unit. Methods All multidisciplinary staff working in the rehabilitation unit were surveyed regarding barriers, facilitators and perceptions of the effect of a 6-day physiotherapy service on length of stay (LOS) and patient goal attainment at three time points: before and after implementation, as well as after modification of a 6-day physiotherapy service. Descriptive statistics and thematic analysis was used to analyse the data. Results Fifty-one staff (50%) responded. Before implementation, all staff identified barriers, the most common being staffing (62%) and patient selection (29%). After implementation, only 30% of staff identified barriers, which differed to those identified before implementation, and included staff rostering and experience (20%), timing of therapy (10%) and increasing the allocation of patients (5%). Over time, staff perceptions changed from being unsure to being positive about the effect of the 6-day service on LOS and patient goal attainment. Conclusion Staff perceived a large number of barriers before implementation of a 6-day rehabilitation service, but these did not eventuate following implementation. Staff perceived improved LOS and patient goal attainment after implementation of a 6-day rehabilitation service incorporating staff feedback. What is known about this topic? Rehabilitation weekend services improve patient quality of life and functional independence while reducing LOS. What does this study add? Staff feedback during implementation and modification of new services is important to address potential barriers and ensure staff satisfaction and support. What are the implications for practitioners? Staff engagement and open communication are important to successfully implement a new service in rehabilitation.

Perinatal supplementation of 4-phenylbutyrate and glutamine attenuates endoplasmic reticulum stress and improves colonic epithelial barrier function in rats born with intrauterine growth restriction.

PubMed

Désir-Vigné, Axel; Haure-Mirande, Vianney; de Coppet, Pierre; Darmaun, Dominique; Le Dréan, Gwenola; Segain, Jean-Pierre

2018-05-01

Intrauterine growth restriction (IUGR) can affect the structure and function of the intestinal barrier and increase digestive disease risk in adulthood. Using the rat model of maternal dietary protein restriction (8% vs. 20%), we found that the colon of IUGR offspring displayed decreased mRNA expression of epithelial barrier proteins MUC2 and occludin during development. This was associated with increased mRNA expression of endoplasmic reticulum (ER) stress marker XBP1s and increased colonic permeability measured in Ussing chambers. We hypothesized that ER stress contributes to colonic barrier alterations and that perinatal supplementation of dams with ER stress modulators, phenylbutyrate and glutamine (PG) could prevent these defects in IUGR offspring. We first demonstrated that ER stress induction by tunicamycin or thapsigargin increased the permeability of rat colonic tissues mounted in Ussing chamber and that PG treatment prevented this effect. Therefore, we supplemented the diet of control and IUGR dams with PG during gestation and lactation. Real-time polymerase chain reaction and histological analysis of colons from 120-day-old offspring revealed that perinatal PG treatment partially prevented the increased expression of ER stress markers but reversed the reduction of crypt depth and goblet cell number in IUGR rats. In dextran sodium sulfate-induced injury and recovery experiments, the colon of IUGR rats without perinatal PG treatment showed higher XBP1s mRNA levels and histological scores of inflammation than IUGR rats with perinatal PG treatment. In conclusion, these data suggest that perinatal supplementation with PG could alleviate ER stress and prevent epithelial barrier dysfunction in IUGR offspring. Copyright © 2017 Elsevier Inc. All rights reserved.

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

PubMed Central

Eriksson, Jens; Khranovskyy, Volodymyr; Iakimov, Tihomir; Lloyd Spetz, Anita; Yakimova, Rositsa

2016-01-01

A vertical diode structure comprising homogeneous monolayer epitaxial graphene on silicon carbide is fabricated by thermal decomposition of a Si-face 4H-SiC wafer in argon atmosphere. Current–voltage characteristics of the graphene/SiC Schottky junction were analyzed by applying the thermionic-emission theory. Extracted values of the Schottky barrier height and the ideality factor are found to be 0.4879 ± 0.013 eV and 1.01803 ± 0.0049, respectively. Deviations of these parameters from average values are smaller than those of previously observed literature data, thereby implying uniformity of the Schottky barrier height over the whole diode area, a stable rectifying behaviour and a good quality of ohmic palladium–graphene contacts. Keeping in mind the strong sensitivity of graphene to analytes we propose the possibility to use the graphene/SiC Schottky diode as a sensing platform for the recognition of toxic heavy metals. Using density functional theory (DFT) calculations we gain insight into the nature of the interaction of cadmium, mercury and lead with graphene as well as estimate the work function and the Schottky barrier height of the graphene/SiC structure before and after applying heavy metals to the sensing material. A shift of the I–V characteristics of the graphene/SiC-based sensor has been proposed as an indicator of presence of the heavy metals. Since the calculations suggested the strongest charge transfer between Pb and graphene, the proposed sensing platform was characterized by good selectivity towards lead atoms and slight interferences from cadmium and mercury. The dependence of the sensitivity parameters on the concentration of Cd, Hg and Pb is studied and discussed. PMID:28144530

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals.

PubMed

Shtepliuk, Ivan; Eriksson, Jens; Khranovskyy, Volodymyr; Iakimov, Tihomir; Lloyd Spetz, Anita; Yakimova, Rositsa

2016-01-01

A vertical diode structure comprising homogeneous monolayer epitaxial graphene on silicon carbide is fabricated by thermal decomposition of a Si-face 4H-SiC wafer in argon atmosphere. Current-voltage characteristics of the graphene/SiC Schottky junction were analyzed by applying the thermionic-emission theory. Extracted values of the Schottky barrier height and the ideality factor are found to be 0.4879 ± 0.013 eV and 1.01803 ± 0.0049, respectively. Deviations of these parameters from average values are smaller than those of previously observed literature data, thereby implying uniformity of the Schottky barrier height over the whole diode area, a stable rectifying behaviour and a good quality of ohmic palladium-graphene contacts. Keeping in mind the strong sensitivity of graphene to analytes we propose the possibility to use the graphene/SiC Schottky diode as a sensing platform for the recognition of toxic heavy metals. Using density functional theory (DFT) calculations we gain insight into the nature of the interaction of cadmium, mercury and lead with graphene as well as estimate the work function and the Schottky barrier height of the graphene/SiC structure before and after applying heavy metals to the sensing material. A shift of the I - V characteristics of the graphene/SiC-based sensor has been proposed as an indicator of presence of the heavy metals. Since the calculations suggested the strongest charge transfer between Pb and graphene, the proposed sensing platform was characterized by good selectivity towards lead atoms and slight interferences from cadmium and mercury. The dependence of the sensitivity parameters on the concentration of Cd, Hg and Pb is studied and discussed.

Executive Functioning, Barriers to Adherence, and Nonadherence in Adolescent and Young Adult Transplant Recipients.

PubMed

Gutiérrez-Colina, Ana M; Eaton, Cyd K; Lee, Jennifer L; Reed-Knight, Bonney; Loiselle, Kristin; Mee, Laura L; LaMotte, Julia; Liverman, Rochelle; Blount, Ronald L

2016-08-01

OBJECTIVE : To evaluate levels of executive functioning in a sample of adolescent and young adult (AYA) transplant recipients, and to examine executive functioning in association with barriers to adherence and medication nonadherence.  METHOD : In all, 41 caregivers and 39 AYAs were administered self- and proxy-report measures.  RESULTS : AYA transplant recipients have significant impairments in executive functioning abilities. Greater dysfunction in specific domains of executive functioning was significantly associated with more barriers to adherence and greater medication nonadherence.  CONCLUSION : AYA transplant recipients are at increased risk for executive dysfunction. The assessment of executive functioning abilities may guide intervention efforts designed to decrease barriers to adherence and promote developmentally appropriate levels of treatment responsibility. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Significant improvement in the electrical characteristics of Schottky barrier diodes on molecularly modified Gallium Nitride surfaces

NASA Astrophysics Data System (ADS)

Garg, Manjari; Naik, Tejas R.; Pathak, C. S.; Nagarajan, S.; Rao, V. Ramgopal; Singh, R.

2018-04-01

III-Nitride semiconductors face the issue of localized surface states, which causes fermi level pinning and large leakage current at the metal semiconductor interface, thereby degrading the device performance. In this work, we have demonstrated the use of a Self-Assembled Monolayer (SAM) of organic molecules to improve the electrical characteristics of Schottky barrier diodes (SBDs) on n-type Gallium Nitride (n-GaN) epitaxial films. The electrical characteristics of diodes were improved by adsorption of SAM of hydroxyl-phenyl metallated porphyrin organic molecules (Zn-TPPOH) onto the surface of n-GaN. SAM-semiconductor bonding via native oxide on the n-GaN surface was confirmed using X-ray photoelectron spectroscopy measurements. Surface morphology and surface electronic properties were characterized using atomic force microscopy and Kelvin probe force microscopy. Current-voltage characteristics of different metal (Cu, Ni) SBDs on bare n-GaN were compared with those of Cu/Zn-TPPOH/n-GaN and Ni/Zn-TPPOH/n-GaN SBDs. It was found that due to the molecular monolayer, the surface potential of n-GaN was decreased by ˜350 mV. This caused an increase in the Schottky barrier height of Cu and Ni SBDs from 1.13 eV to 1.38 eV and 1.07 eV to 1.22 eV, respectively. In addition to this, the reverse bias leakage current was reduced by 3-4 orders of magnitude for both Cu and Ni SBDs. Such a significant improvement in the electrical performance of the diodes can be very useful for better device functioning.

Depression in Home-Based Care: The Role of the Home Health Nurse.

PubMed

Groh, Carla J; Dumlao, Manuel S

2016-01-01

Depression is a major health issue among older adults receiving home-based services yet is underdiagnosed and undertreated, which can result in negative health outcomes. Despite the recognized need for improved mental health services, significant gaps and barriers exist that contribute to less than optimal home-based depression management interventions. Home healthcare clinicians are well positioned to drive this effort for improving depression care with enhanced learning. Thus, the purpose of this article is to provide guidelines on improving depression care in homebound older adults based on four clinical functions central to home healthcare: screening, assessment, medication management, and patient/family education.

Barriers to the treatment of social anxiety.

PubMed

Olfson, M; Guardino, M; Struening, E; Schneier, F R; Hellman, F; Klein, D F

2000-04-01

This article evaluates barriers to treatment reported by adults with social anxiety who participated in the 1996 National Anxiety Disorders Screening Day. The background characteristics of screening day participants with symptoms of social anxiety (N=6,130) were compared with those of participants without social anxiety (N=4,507). Barriers to previous mental health treatment reported by participants with and without symptoms of social anxiety were compared. Social anxiety was strongly associated with functional impairment, feelings of social isolation, and suicidal ideation. Compared to participants without social anxiety, those with social anxiety were significantly more likely to report that financial barriers, uncertainty over where to go for help, and fear of what others might think or say prevented them from seeking treatment. However, they were significantly less likely to report they avoided treatment because they did not believe they had an anxiety disorder. Roughly one-third (N=1,400 of 3,682, 38.0%) of the participants with symptoms of social anxiety who were referred for further evaluation were specifically referred for an evaluation for social phobia. Social anxiety is associated with a distinct pattern of treatment barriers. Treatment access may be improved by building public awareness of locally available services, easing the psychological and financial burden of entering treatment, and increasing health care professionals' awareness of its clinical significance.

Design of barrier coatings on kink-resistant peripheral nerve conduits

PubMed Central

Clements, Basak Acan; Bushman, Jared; Murthy, N Sanjeeva; Ezra, Mindy; Pastore, Christopher M; Kohn, Joachim

2016-01-01

Here, we report on the design of braided peripheral nerve conduits with barrier coatings. Braiding of extruded polymer fibers generates nerve conduits with excellent mechanical properties, high flexibility, and significant kink-resistance. However, braiding also results in variable levels of porosity in the conduit wall, which can lead to the infiltration of fibrous tissue into the interior of the conduit. This problem can be controlled by the application of secondary barrier coatings. Using a critical size defect in a rat sciatic nerve model, the importance of controlling the porosity of the nerve conduit walls was explored. Braided conduits without barrier coatings allowed cellular infiltration that limited nerve recovery. Several types of secondary barrier coatings were tested in animal studies, including (1) electrospinning a layer of polymer fibers onto the surface of the conduit and (2) coating the conduit with a cross-linked hyaluronic acid-based hydrogel. Sixteen weeks after implantation, hyaluronic acid-coated conduits had higher axonal density, displayed higher muscle weight, and better electrophysiological signal recovery than uncoated conduits or conduits having an electrospun layer of polymer fibers. This study indicates that braiding is a promising method of fabrication to improve the mechanical properties of peripheral nerve conduits and demonstrates the need to control the porosity of the conduit wall to optimize functional nerve recovery. PMID:26977288

The angiopoietin1-Akt pathway regulates barrier function of the cultured spinal cord microvascular endothelial cells through Eps8.

PubMed

Liu, Xinchun; Zhou, Xiaoshu; Yuan, Wei

2014-10-15

In mammalian central nervous system (CNS), the integrity of the blood-spinal cord barrier (BSCB), formed by tight junctions (TJs) between adjacent microvascular endothelial cells near the basement membrane of capillaries and the accessory structures, is important for relatively independent activities of the cellular constituents inside the spinal cord. The barrier function of the BSCB are tightly regulated and coordinated by a variety of physiological or pathological factors, similar with but not quite the same as its counterpart, the blood-brain barrier (BBB). Herein, angiopoietin 1 (Ang1), an identified ligand of the endothelium-specific tyrosine kinase receptor Tie-2, was verified to regulate barrier functions, including permeability, junction protein interactions and F-actin organization, in cultured spinal cord microvascular endothelial cells (SCMEC) of rat through the activity of Akt. Besides, these roles of Ang1 in the BSCB in vitro were found to be accompanied with an increasing expression of epidermal growth factor receptor pathway substrate 8 (Eps8), an F-actin bundling protein. Furthermore, the silencing of Eps8 by lentiviral shRNA resulted in an antagonistic effect vs. Ang1 on the endothelial barrier function of SCMEC. In summary, the Ang1-Akt pathway serves as a regulator in the barrier function modulation of SCMEC via the actin-binding protein Eps8. Copyright © 2014 Elsevier Inc. All rights reserved.

Barrier-protective function of intestinal epithelial Toll-like receptor 2.

PubMed

Cario, E

2008-11-01

The intestinal epithelial cell (IEC) barrier plays an important role in maintaining mucosal immune homeostasis. Dysregulated IEC barrier function appears to trigger and perpetuate inflammation in inflammatory bowel diseases (IBD). Novel risk variants in the Toll-like receptor 2 (TLR2) gene have previously been associated with a more severe disease phenotype in a subgroup of IBD patients. Recent studies have provided important insights of the commensal and host defense mechanisms to maintain functional barrier integrity of the intestinal epithelium through TLR2. Deficient TLR2 signaling may imbalance commensal-dependent intestinal epithelial barrier defense, facilitating mucosal injury and leading to increased susceptibility of colitis. Treatment with a synthetic TLR2 ligand significantly suppresses mucosal inflammation by efficiently protecting tight junction-associated integrity of the intestinal epithelium in vivo. These beneficial effects may be supplemented by TLR2-induced anti-inflammatory immune responses (such as interleukin-10 production) in lamina propria mononuclear cells. Thus, cell-specific TLR2 targeting may offer a novel therapeutic approach to human IBD therapy by protecting IEC barrier function.

Health worker perspectives on barriers to delivery of routine tuberculosis diagnostic evaluation services in Uganda: a qualitative study to guide clinic-based interventions.

PubMed

Cattamanchi, Adithya; Miller, Cecily R; Tapley, Asa; Haguma, Priscilla; Ochom, Emmanuel; Ackerman, Sara; Davis, J Lucian; Katamba, Achilles; Handley, Margaret A

2015-01-22

Studies of the quality of tuberculosis (TB) diagnostic evaluation of patients in high burden countries have generally shown poor adherence to international or national guidelines. Health worker perspectives on barriers to improving TB diagnostic evaluation are critical for developing clinic-level interventions to improve guideline implementation. We conducted structured, in-depth interviews with staff at six district-level health centers in Uganda to elicit their perceptions regarding barriers to TB evaluation. Interviews were transcribed, coded with a standardized framework, and analyzed to identify emergent themes. We used thematic analysis to develop a logic model depicting health system and contextual barriers to recommended TB evaluation practices. To identify possible clinic-level interventions to improve TB evaluation, we categorized findings into predisposing, enabling, and reinforcing factors as described by the PRECEDE model, focusing on potentially modifiable behaviors at the clinic-level. We interviewed 22 health center staff between February 2010 and November 2011. Participants identified key health system barriers hindering TB evaluation, including: stock-outs of drugs/supplies, inadequate space and infrastructure, lack of training, high workload, low staff motivation, and poor coordination of health center services. Contextual barrier challenges to TB evaluation were also reported, including the time and costs borne by patients to seek and complete TB evaluation, poor health literacy, and stigma against patients with TB. These contextual barriers interacted with health system barriers to contribute to sub-standard TB evaluation. Examples of intervention strategies that could address these barriers and are related to PRECEDE model components include: assigned mentors/peer coaching for new staff (targets predisposing factor of low motivation and need for support to conduct job duties); facilitated workshops to implement same day microscopy (targets enabling factor of patient barriers to completing TB evaluation), and recognition/incentives for good TB screening practices (targets low motivation and self-efficacy). Our findings suggest that health system and contextual barriers work together to impede TB diagnosis at health centers and, if not addressed, could hinder TB case detection efforts. Qualitative research that improves understanding of the barriers facing TB providers is critical to developing targeted interventions to improve TB care.

Altered Expression of ZO-1 and ZO-2 in Sertoli Cells and Loss of Blood-Testis Barrier Integrity in Testicular Carcinoma In Situ1

PubMed Central

Fink, Cornelia; Weigel, Roswitha; Hembes, Tanja; Lauke-Wettwer, Heidrun; Kliesch, Sabine; Bergmann, Martin; Brehm, Ralph H

2006-01-01

Abstract Carcinoma in situ (CIS) is the noninvasive precursor of most human testicular germ cell tumors. In normal seminiferous epithelium, specialized tight junctions between Sertoli cells constitute the major component of the blood-testis barrier. Sertoli cells associated with CIS exhibit impaired maturation status, but their functional significance remains unknown. The aim was to determine whether the blood-testis barrier is morphologically and/or functionally altered. We investigated the expression and distribution pattern of the tight junction proteins zonula occludens (ZO) 1 and 2 in normal seminiferous tubules compared to tubules showing CIS. In normal tubules, ZO-1 and ZO-2 immunostaining was observed at the blood-testis barrier region of adjacent Sertoli cells. Within CIS tubules, ZO-1 and ZO-2 immunoreactivity was reduced at the blood-testis barrier region, but spread to stain the Sertoli cell cytoplasm. Western blot analysis confirmed ZO-1 and ZO-2, and their respective mRNA were shown by RT-PCR. Additionally, we assessed the functional integrity of the blood-testis barrier by lanthanum tracer study. Lanthanum permeated tight junctions in CIS tubules, indicating disruption of the blood-testis barrier. In conclusion, Sertoli cells associated with CIS show an altered distribution of ZO-1 and ZO-2 and lose their blood-testis barrier function. PMID:17217619

Overview of thermal barrier coatings in diesel engines

NASA Technical Reports Server (NTRS)

Yonushonis, T. M.

1995-01-01

An understanding of delamination mechanisms in thermal barrier coatings has been developed for diesel applications through nondestructive evaluation, structural analysis modeling and engine evaluation of various thermal barrier coatings. This knowledge has resulted in improved thermal barrier coatings which survive abusive cyclic fatigue tests in high output diesel engines. Significant efforts are still required to improve the plasma spray processing capability and the economics for complex geometry diesel engine components. Data obtained from advanced diesel engines on the effect of thermal barrier coatings on engine fuel economy and emission has not been encouraging. Although the underlying metal component temperatures have been reduced through the use of thermal barrier coating, engine efficiency and emission trends have not been promising.

Transient Intervals of Hyper-Gravity Enhance Endothelial Barrier Integrity: Impact of Mechanical and Gravitational Forces Measured Electrically

PubMed Central

Szulcek, Robert; van Bezu, Jan; Boonstra, Johannes; van Loon, Jack J. W. A.; van Nieuw Amerongen, Geerten P.

2015-01-01

Background Endothelial cells (EC) guard vascular functions by forming a dynamic barrier throughout the vascular system that sensitively adapts to ‘classical’ biomechanical forces, such as fluid shear stress and hydrostatic pressure. Alterations in gravitational forces might similarly affect EC integrity, but remain insufficiently studied. Methods In an unique approach, we utilized Electric Cell-substrate Impedance Sensing (ECIS) in the gravity-simulators at the European Space Agency (ESA) to study dynamic responses of human EC to simulated micro- and hyper-gravity as well as to classical forces. Results Short intervals of micro- or hyper-gravity evoked distinct endothelial responses. Stimulated micro-gravity led to decreased endothelial barrier integrity, whereas hyper-gravity caused sustained barrier enhancement by rapid improvement of cell-cell integrity, evidenced by a significant junctional accumulation of VE-cadherin (p = 0.011), significant enforcement of peripheral F-actin (p = 0.008) and accompanied by a slower enhancement of cell-matrix interactions. The hyper-gravity triggered EC responses were force dependent and nitric-oxide (NO) mediated showing a maximal resistance increase of 29.2±4.8 ohms at 2g and 60.9±6.2 ohms at 4g vs. baseline values that was significantly suppressed by NO blockage (p = 0.011). Conclusion In conclusion, short-term application of hyper-gravity caused a sustained improvement of endothelial barrier integrity, whereas simulated micro-gravity weakened the endothelium. In clear contrast, classical forces of shear stress and hydrostatic pressure induced either short-lived or no changes to the EC barrier. Here, ECIS has proven a powerful tool to characterize subtle and distinct EC gravity-responses due to its high temporal resolution, wherefore ECIS has a great potential for the study of gravity-responses such as in real space flights providing quantitative assessment of a variety of cell biological characteristics of any adherent growing cell type in an automated and continuous fashion. PMID:26637177

EICOSAPENTAENOIC ACID ENHANCES HEATSTROKE-IMPAIRED INTESTINAL EPITHELIAL BARRIER FUNCTION IN RATS.

PubMed

Xiao, Guizhen; Yuan, Fangfang; Geng, Yan; Qiu, Xiaowen; Liu, Zhifeng; Lu, Jiefu; Tang, Liqun; Zhang, Yali; Su, Lei

2015-10-01

Dysfunction of the intestinal barrier plays an important role in the pathological process of heatstroke. Omega-3 (or n-3) polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), help protect the intestinal mucosal barrier. This study assessed if pretreating rats with EPA or DHA could alleviate heat stress-induced damage to the intestinal barrier caused by experimental heatstroke. Male Wistar rats were pregavaged with either EPA, DHA, corn oil, or normal saline (all 1 g/kg) for 21 days before the heatstroke experiment (control rats were not exposed to heat). Experimental rats were exposed to an ambient temperature of 37°C and 60% humidity to induce heatstroke, and then they were allowed to recover at room temperature after rapid cooling. Survival time of rats was monitored after heatstroke. Horseradish peroxidase flux from the gut lumen and the level of plasma D-lactate were measured to analyze intestinal permeability at 6 h after heatstroke. Plasma endotoxin levels were determined using a limulus amoebocyte lysate assay. Expressions of the tight junction (TJ) proteins occludin and ZO-1 were analyzed by Western blot and localized by immunofluorescence microscopy. Tight junction protein morphology was observed by transmission electron microscopy. Fatty acids of ileal mucosa were analyzed using gas chromatography-mass selective detector. Eicosapentaenoic acid significantly increased survival time after heatstroke. Eicosapentaenoic acid significantly decreased intestinal permeability and plasma endotoxin levels. Eicosapentaenoic acid effectively attenuated the heatstroke-induced disruption of the intestinal structure and improved the histology score, whereas DHA was less effective, and corn oil was ineffective. Pretreatment with EPA also increased expression of occludin and ZO-1 to effectively prevent TJ disruption. Eicosapentaenoic acid pretreatment enriched itself in the membrane of intestinal cells. Our results indicate that EPA pretreatment is more effective than DHA pretreatment in attenuating heat-induced intestinal dysfunction and preventing TJ damage. Enhanced expression of TJ proteins that support the epithelial barrier integrity may be important for maintaining a functional intestinal barrier during heatstroke.

Arabinoxylan-lipids-based edible films and coatings. 2. Influence of sucroester nature on the emulsion structure and film properties.

PubMed

Phan The, D; Péroval, C; Debeaufort, F; Despré, D; Courthaudon, J L; Voilley, A

2002-01-16

This work is a contribution to better knowledge of the influence of the structure of films on their functional properties obtained from emulsions based on arabinoxylans, hydrogenated palm kernel oil (HPKO), and emulsifiers. The sucroesters (emulsifiers) have a great effect on the stabilization of the emulsified film structure containing arabinoxylans and hydrogenated palm kernel oil. They improve the moisture barrier properties. Several sucroesters having different esterification degrees were tested. Both lipophilic (90% of di and tri-ester) and hydrophilic (70% of mono-ester) sucrose esters can ensure the stability of the emulsion used to form the film, especially during preparation and drying. These emulsifiers confer good moisture barrier properties to emulsified films.

Effect of vilon and epithalon on activity of enzymes in epithelial and subepithelial layers in small intestine of old rats.

PubMed

Khavinson, V Kh; Timofeeva, N M; Malinin, V V; Gordova, L A; Nikitina, A A

2002-12-01

Per os administration of Vilon (Lys-Glu) or Epithalon (Ala-Glu-Asp-Gly) to aged Wistar rats for 1 month significantly increased activity of membrane enzymes maltase and alkaline phosphatase in epithelial layer of the small intestine. In addition, Vilon significantly increased activity of cytosolic glycyl-L-leucine dipeptidase in the stromal and seromuscular layers of the small intestine in comparison with the control rats not treated with this agent. These findings suggest improvement of trophic and barrier functions of the small intestine and corroborate the hypothesis on the existence of not only epithelial, but also subepithelial enzymatic barrier supporting the enzyme system in the small intestine, especially in aged animals.

Quantum thermostatted disordered systems and sensitivity under compression

NASA Astrophysics Data System (ADS)

Vanzan, Tommaso; Rondoni, Lamberto

2018-03-01

A one-dimensional quantum system with off diagonal disorder, consisting of a sample of conducting regions randomly interspersed within potential barriers is considered. Results mainly concerning the large N limit are presented. In particular, the effect of compression on the transmission coefficient is investigated. A numerical method to simulate such a system, for a physically relevant number of barriers, is proposed. It is shown that the disordered model converges to the periodic case as N increases, with a rate of convergence which depends on the disorder degree. Compression always leads to a decrease of the transmission coefficient which may be exploited to design nano-technological sensors. Effective choices for the physical parameters to improve the sensitivity are provided. Eventually large fluctuations and rate functions are analysed.

The Self-Assembly of DNA Nanostructures for use as Organizing Templates

NASA Astrophysics Data System (ADS)

Samec, Timothy; Cholewinski, Mitchell; Reamer, Nickalas; Reardon, Michael; Ford, Arlene

There is growing interest in the self-assembling capabilities of DNA to create functional nanodevices for use in cancer detection and treatment. One important reason for this interest is that DNA nanostructures are highly programmable molecules. This means that these structures allow for increased stability and control when designing biomacromolecules via adhesion of plasmonic nanoparticles and other similar materials. Our current work reports on the procedure and construction of hexagonal two-dimensional DNA lattice structures using three specific DNA single strands. We also reflect on several barriers that were presented during fabrication as well as the adaptations made to overcome the aforementioned barriers by improving the quality, reproducibility, and yield of the hexagonal two-dimensional DNA lattice as organizing templates.

Diet, Microbiome, and the Intestinal Epithelium: An Essential Triumvirate?

PubMed Central

Guzman, Javier Rivera; Conlin, Victoria Susan; Jobin, Christian

2013-01-01

The intestinal epithelium represents a critical barrier protecting the host against diverse luminal noxious agents, as well as preventing the uncontrolled uptake of bacteria that could activate an immune response in a susceptible host. The epithelial monolayer that constitutes this barrier is regulated by a meshwork of proteins that orchestrate complex biological function such as permeability, transepithelial electrical resistance, and movement of various macromolecules. Because of its key role in maintaining host homeostasis, factors regulating barrier function have attracted sustained attention from the research community. This paper will address the role of bacteria, bacterial-derived metabolism, and the interplay of dietary factors in controlling intestinal barrier function. PMID:23586037

Changes in gut microbiota control inflammation in obese mice through a mechanism involving GLP-2-driven improvement of gut permeability.

PubMed

Cani, P D; Possemiers, S; Van de Wiele, T; Guiot, Y; Everard, A; Rottier, O; Geurts, L; Naslain, D; Neyrinck, A; Lambert, D M; Muccioli, G G; Delzenne, N M

2009-08-01

Obese and diabetic mice display enhanced intestinal permeability and metabolic endotoxaemia that participate in the occurrence of metabolic disorders. Our recent data support the idea that a selective increase of Bifidobacterium spp. reduces the impact of high-fat diet-induced metabolic endotoxaemia and inflammatory disorders. Here, we hypothesised that prebiotic modulation of gut microbiota lowers intestinal permeability, by a mechanism involving glucagon-like peptide-2 (GLP-2) thereby improving inflammation and metabolic disorders during obesity and diabetes. Study 1: ob/ob mice (Ob-CT) were treated with either prebiotic (Ob-Pre) or non-prebiotic carbohydrates as control (Ob-Cell). Study 2: Ob-CT and Ob-Pre mice were treated with GLP-2 antagonist or saline. Study 3: Ob-CT mice were treated with a GLP-2 agonist or saline. We assessed changes in the gut microbiota, intestinal permeability, gut peptides, intestinal epithelial tight-junction proteins ZO-1 and occludin (qPCR and immunohistochemistry), hepatic and systemic inflammation. Prebiotic-treated mice exhibited a lower plasma lipopolysaccharide (LPS) and cytokines, and a decreased hepatic expression of inflammatory and oxidative stress markers. This decreased inflammatory tone was associated with a lower intestinal permeability and improved tight-junction integrity compared to controls. Prebiotic increased the endogenous intestinotrophic proglucagon-derived peptide (GLP-2) production whereas the GLP-2 antagonist abolished most of the prebiotic effects. Finally, pharmacological GLP-2 treatment decreased gut permeability, systemic and hepatic inflammatory phenotype associated with obesity to a similar extent as that observed following prebiotic-induced changes in gut microbiota. We found that a selective gut microbiota change controls and increases endogenous GLP-2 production, and consequently improves gut barrier functions by a GLP-2-dependent mechanism, contributing to the improvement of gut barrier functions during obesity and diabetes.

Fusion cross sections for reactions involving medium and heavy nucleus-nucleus systems

NASA Astrophysics Data System (ADS)

Atta, Debasis; Basu, D. N.

2014-12-01

Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed by using a simple diffused-barrier formula derived assuming the Gaussian shape of the barrier-height distributions. The fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existing data on near-barrier fusion and capture excitation functions for medium and heavy nucleus-nucleus systems. The theoretical values for the parameters of the barrier distribution are estimated which can be used for fusion or capture cross-section predictions that are especially important for planning experiments for synthesizing new superheavy elements.

The QTP family of consistent functionals and potentials in Kohn-Sham density functional theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Yifan; Bartlett, Rodney J., E-mail: bartlett@qtp.ufl.edu

This manuscript presents the second, consistent density functional in the QTP (Quantum Theory Project) family, that is, the CAM-QTP(01). It is a new range-separated exchange-correlation functional in which the non-local exchange contribution is 100% at large separation. It follows the same basic principles of this family that the Kohn-Sham eigenvalues of the occupied orbitals approximately equal the vertical ionization energies, which is not fulfilled by most of the traditional density functional methods. This new CAM-QTP(01) functional significantly improves the accuracy of the vertical excitation energies especially for the Rydberg states in the test set. It also reproduces many other propertiesmore » such as geometries, reaction barrier heights, and atomization energies.« less

Damage and recovery of skin barrier function after glycolic acid chemical peeling and crystal microdermabrasion.

PubMed

Song, Ji Youn; Kang, Hyun A; Kim, Mi-Yeon; Park, Young Min; Kim, Hyung Ok

2004-03-01

Superficial chemical peeling and microdermabrasion have become increasingly popular methods for producing facial rejuvenation. However, there are few studies reporting the skin barrier function changes after these procedures. To evaluate objectively the degree of damage visually and the time needed for the skin barrier function to recover after glycolic acid peeling and aluminum oxide crystal microdermabrasion using noninvasive bioengineering methods. Superficial chemical peeling using 30%, 50%, and 70% glycolic acid and aluminum oxide crystal microdermabrasion were used on the volar forearm of 13 healthy women. The skin response was measured by a visual observation and using an evaporimeter, corneometer, and colorimeter before and after peeling at set time intervals. Both glycolic acid peeling and aluminum oxide crystal microdermabrasion induced significant damage to the skin barrier function immediately after the procedure, and the degree of damage was less severe after the aluminum oxide crystal microdermabrasion compared with glycolic acid peeling. The damaged skin barrier function had recovered within 24 hours after both procedures. The degree of erythema induction was less severe after the aluminum oxide crystal microdermabrasion compared with the glycolic acid peeling procedure. The degree of erythema induced after the glycolic acid peeling procedure was not proportional to the peeling solution concentration used. The erythema subsided within 1 day after the aluminum oxide crystal microdermabrasion procedure and within 4 days after the glycolic acid peeling procedure. These results suggest that the skin barrier function is damaged after the glycolic acid peeling and aluminum oxide crystal microdermabrasion procedure but recovers within 1 to 4 days. Therefore, repeating the superficial peeling procedure at 2-week intervals will allow sufficient time for the damaged skin to recover its barrier function.

An investigation of ADA compliance of aquatic facilities in the North Texas area.

PubMed

Pike, Hilary; Walker, Joseph; Collins, John; Hodges, Jan

2008-01-01

The study expands research on accessibility, comparing compliance scores of aquatic facilities in North Texas built before the 1991 Title III Americans with Disabilities Act Accessibility Guidelines (ADAAG) with facilities built after the 1991 ADAAG and the proposed 2002 supplement. A quasi-experimental design directed the selection of 52 facilities where measurements were taken to determine compliance with ADAAG and the supplement. A focus group provided insight into interpreting which features functioned as barriers or constraints to participation. Metropolitan statistical area in North Texas. A total of 52 aquatic facilities and 12 focus group participants (University of North Texas institutional review board 07-283). ADA aquatic facility compliance instrument. Frequency, ratios. No facilities were 100% ADA compliant overall, although some facilities were 100% compliant with specific structural domains. Women's restrooms rated lowest (average = 55%), and men's restrooms received the second lowest rating (average = 64%). Focus group results indicated that improperly designed restrooms and pool entries are primary barriers to participation. The findings support a need for stronger enforcement of policies that improve accessibility of facilities. Architectural reviews and construction practices need to be improved. The structural barriers and constraints identified can be limiting factors in efforts aimed at increasing physical activity among individuals with disabilities and individuals with physical limitations.

Testing a path-analytic mediation model of how motivational enhancement physiotherapy improves physical functioning in pain patients.

PubMed

Cheing, Gladys; Vong, Sinfia; Chan, Fong; Ditchman, Nicole; Brooks, Jessica; Chan, Chetwyn

2014-12-01

Pain is a complex phenomenon not easily discerned from psychological, social, and environmental characteristics and is an oft cited barrier to return to work for people experiencing low back pain (LBP). The purpose of this study was to evaluate a path-analytic mediation model to examine how motivational enhancement physiotherapy, which incorporates tenets of motivational interviewing, improves physical functioning of patients with chronic LBP. Seventy-six patients with chronic LBP were recruited from the outpatient physiotherapy department of a government hospital in Hong Kong. The re-specified path-analytic model fit the data very well, χ (2)(3, N = 76) = 3.86, p = .57; comparative fit index = 1.00; and the root mean square error of approximation = 0.00. Specifically, results indicated that (a) using motivational interviewing techniques in physiotherapy was associated with increased working alliance with patients, (b) working alliance increased patients' outcome expectancy and (c) greater outcome expectancy resulted in a reduction of subjective pain intensity and improvement in physical functioning. Change in pain intensity also directly influenced improvement in physical functioning. The effect of motivational enhancement therapy on physical functioning can be explained by social-cognitive factors such as motivation, outcome expectancy, and working alliance. The use of motivational interviewing techniques to increase outcome expectancy of patients and improve working alliance could further strengthen the impact of physiotherapy on rehabilitation outcomes of patients with chronic LBP.

Goat milk with and without increased concentrations of lysozyme improves repair of intestinal cell damage induced by enteroaggregative Escherichia coli.

PubMed

Carvalho, Eunice B; Maga, Elizabeth A; Quetz, Josiane S; Lima, Ila F N; Magalhães, Hemerson Y F; Rodrigues, Felipe A R; Silva, Antônio V A; Prata, Mara M G; Cavalcante, Paloma A; Havt, Alexandre; Bertolini, Marcelo; Bertolini, Luciana R; Lima, Aldo A M

2012-08-11

Enteroaggregative Escherichia coli (EAEC) causes diarrhea, malnutrition and poor growth in children. Human breast milk decreases disease-causing bacteria by supplying nutrients and antimicrobial factors such as lysozyme. Goat milk with and without human lysozyme (HLZ) may improve the repair of intestinal barrier function damage induced by EAEC. This work investigates the effect of the milks on intestinal barrier function repair, bacterial adherence in Caco-2 and HEp-2 cells, intestinal cell proliferation, migration, viability and apoptosis in IEC-6 cells in the absence or presence of EAEC. Rat intestinal epithelial cells (IEC-6, ATCC, Rockville, MD) were used for proliferation, migration and viability assays and human colon adenocarcinoma (Caco-2, ATCC, Rockville, MD) and human larynx carcinoma (HEp-2, ATCC, Rockville, MD) cells were used for bacterial adhesion assays. Goats expressing HLZ in their milk were generated and express HLZ in milk at concentration of 270 μg/ml. Cells were incubated with pasteurized milk from either transgenic goats expressing HLZ or non-transgenic control goats in the presence and absence of EAEC strain 042 (O44:H18). Cellular proliferation was significantly greater in the presence of both HLZ transgenic and control goat milk compared to cells with no milk. Cellular migration was significantly decreased in the presence of EAEC alone but was restored in the presence of milk. Milk from HLZ transgenic goats had significantly more migration compared to control milk. Both milks significantly reduced EAEC adhesion to Caco-2 cells and transgenic milk resulted in less colonization than control milk using a HEp-2 assay. Both milks had significantly increased cellular viability as well as less apoptosis in both the absence and presence of EAEC. These data demonstrated that goat milk is able to repair intestinal barrier function damage induced by EAEC and that goat milk with a higher concentration of lysozyme offers additional protection.

Toward an Integrated Research Agenda for Critical Illness in Aging

PubMed Central

Milbrandt, Eric B.; Eldadah, Basil; Nayfield, Susan; Hadley, Evan; Angus, Derek C.

2010-01-01

Aging brings an increased predisposition to critical illness. Patients older than 65 years of age account for approximately half of all intensive care unit (ICU) admissions in the United States, a proportion that is expected to increase considerably with the aging of the population. Emerging research suggests that elderly survivors of intensive care suffer significant long-term sequelae, including accelerated age-related functional decline. Existing evidence-based interventions are frequently underused and their efficacy untested in older subjects. Improving ICU outcomes in the elderly will require not only better methods for translating sound science into improved ICU practice but also an enhanced understanding of the underlying molecular, physiological, and pathophysiological interactions of critical illness with the aging process itself. Yet, significant barriers to research for critical illness in aging exist. We review the state of knowledge and identify gaps in knowledge, research opportunities, and barriers to research, with the goal of promoting an integrated research agenda for critical illness in aging. PMID:20558632

Play@home in practice: health visitors' views of perceived facilitators and barriers to programme implementation.

PubMed

Miller, Irene; Barton, Gil

2013-07-01

Health visitors in Scotland gift 'play@home', a book-based early intervention programme, to parents as part of the universal health visiting service. The provision of health improvement information to parents is recognised as a core function of health visiting and yet evidence shows that not every family receives the play@home resources. This paper discusses the perceived facilitators and barriers to implementing this programme through exploring the views of ten health visitors and four health visiting managers in two health board areas in Scotland. The findings conclude that increasingly vulnerable families, supported by fewer qualified health visitors, present challenges to the health visiting service. The play@home programme is valued by health visitors as a flexible tool with which to engage with families. Collaborative working with other services enhances provision and play@home does become embedded in practice over time. Strategic policy links to raise the profile of play@home are improving.

Designing solid-liquid interphases for sodium batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choudhury, Snehashis; Wei, Shuya; Ozhabes, Yalcin

Secondary batteries based on earth-abundant sodium metal anodes are desirable for both stationary and portable electrical energy storage. Room-temperature sodium metal batteries are impractical today because morphological instability during recharge drives rough, dendritic electrodeposition. Chemical instability of liquid electrolytes also leads to premature cell failure as a result of parasitic reactions with the anode. Here we use joint density-functional theoretical analysis to show that the surface diffusion barrier for sodium ion transport is a sensitive function of the chemistry of solid–electrolyte interphase. In particular, we find that a sodium bromide interphase presents an exceptionally low energy barrier to ion transport,more » comparable to that of metallic magnesium. We evaluate this prediction by means of electrochemical measurements and direct visualization studies. These experiments reveal an approximately three-fold reduction in activation energy for ion transport at a sodium bromide interphase. Direct visualization of sodium electrodeposition confirms large improvements in stability of sodium deposition at sodium bromide-rich interphases.« less

Addressing safety liabilities of TfR bispecific antibodies that cross the blood-brain barrier.

PubMed

Couch, Jessica A; Yu, Y Joy; Zhang, Yin; Tarrant, Jacqueline M; Fuji, Reina N; Meilandt, William J; Solanoy, Hilda; Tong, Raymond K; Hoyte, Kwame; Luk, Wilman; Lu, Yanmei; Gadkar, Kapil; Prabhu, Saileta; Ordonia, Benjamin A; Nguyen, Quyen; Lin, Yuwen; Lin, Zhonghua; Balazs, Mercedesz; Scearce-Levie, Kimberly; Ernst, James A; Dennis, Mark S; Watts, Ryan J

2013-05-01

Bispecific antibodies using the transferrin receptor (TfR) have shown promise for boosting antibody uptake in brain. Nevertheless, there are limited data on the therapeutic properties including safety liabilities that will enable successful development of TfR-based therapeutics. We evaluate TfR/BACE1 bispecific antibody variants in mouse and show that reducing TfR binding affinity improves not only brain uptake but also peripheral exposure and the safety profile of these antibodies. We identify and seek to address liabilities of targeting TfR with antibodies, namely, acute clinical signs and decreased circulating reticulocytes observed after dosing. By eliminating Fc effector function, we ameliorated the acute clinical signs and partially rescued a reduction in reticulocytes. Furthermore, we show that complement mediates a residual decrease in reticulocytes observed after Fc effector function is eliminated. These data raise important safety concerns and potential mitigation strategies for the development of TfR-based therapies that are designed to cross the blood-brain barrier.

Revealing the Origin of Activity in Nitrogen-Doped Nanocarbons towards Electrocatalytic Reduction of Carbon Dioxide.

PubMed

Xu, Junyuan; Kan, Yuhe; Huang, Rui; Zhang, Bingsen; Wang, Bolun; Wu, Kuang-Hsu; Lin, Yangming; Sun, Xiaoyan; Li, Qingfeng; Centi, Gabriele; Su, Dangsheng

2016-05-23

Carbon nanotubes (CNTs) are functionalized with nitrogen atoms for reduction of carbon dioxide (CO2 ). The investigation explores the origin of the catalyst's activity and the role of nitrogen chemical states therein. The catalysts show excellent performances, with about 90 % current efficiency for CO formation and stability over 60 hours. The Tafel analyses and density functional theory calculations suggest that the reduction of CO2 proceeds through an initial rate-determining transfer of one electron to CO2 , which leads to the formation of carbon dioxide radical anion (CO2 (.-) ). The initial reduction barrier is too high on pristine CNTs, resulting in a very high overpotentials at which the hydrogen evolution reaction dominates over CO2 reduction. The doped nitrogen atoms stabilize the radical anion, thereby lowering the initial reduction barrier and improving the intrinsic activity. The most efficient nitrogen chemical state for this reaction is quaternary nitrogen, followed by pyridinic and pyrrolic nitrogen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The menstrual cycle and the skin.

PubMed

Raghunath, R S; Venables, Z C; Millington, G W M

2015-03-01

Perimenstrual exacerbations of dermatoses are commonly recognized, yet our knowledge of the underlying pathophysiological mechanisms remains imperfect. Research into the effects of oestrogen on the skin has provided evidence to suggest that oestrogen is associated with increases in skin thickness and dermal water content, improved barrier function, and enhanced wound healing. Research into the effects of progesterone suggests that the presence of various dermatoses correlates with peak levels of progesterone. Dermatoses that are exacerbated perimenstrually include acne, psoriasis, atopic eczema and irritant dermatitis, and possibly also erythema multiforme. Exacerbations occur at the peak levels of progesterone in the menstrual cycle. Underlying mechanisms include reduced immune and barrier functions as a result of cyclical fluctuations in oestrogen and/or progesterone. Autoimmune progesterone and oestrogen dermatitis are the best-characterized examples of perimenstrual cutaneous reactions to hormones produced during the menstrual cycle. In this review, we describe the current understanding of the menstrual cycle, and its effect on the skin and cutaneous disorders. © 2015 British Association of Dermatologists.

Dietary polyphenols increase fecal mucin and immunoglobulin A and ameliorate the disturbance in gut microbiota caused by a high fat diet.

PubMed

Taira, Toshio; Yamaguchi, Sayori; Takahashi, Azusa; Okazaki, Yukako; Yamaguchi, Akihiro; Sakaguchi, Hirohide; Chiji, Hideyuki

2015-11-01

The effects of dietary polyphenols on human health have mainly been discussed in the context of preventing degenerative diseases, particularly cardiovascular diseases and cancer. The antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanism of action of polyphenols extends beyond the modulation of oxidative stress, as they are poorly absorbed from the digestive tract. The purpose of this study was to clarify the effects of polyphenols on the colonic environment, intestinal barrier function, and gut microbiota. We demonstrated that dietary polyphenols derived from aronia, haskap, and bilberry, markedly elevated the amount of fecal mucin and immunoglobulin A (IgA) as an intestinal barrier function and ameliorated the disturbance in gut microbiota caused by a high fat diet in rats. These results suggest that dietary polyphenols play a significant role in the prevention of degenerative diseases through improvement of the colonic environment without any absorption from the digestive tract.

Dietary polyphenols increase fecal mucin and immunoglobulin A and ameliorate the disturbance in gut microbiota caused by a high fat diet

PubMed Central

Taira, Toshio; Yamaguchi, Sayori; Takahashi, Azusa; Okazaki, Yukako; Yamaguchi, Akihiro; Sakaguchi, Hirohide; Chiji, Hideyuki

2015-01-01

The effects of dietary polyphenols on human health have mainly been discussed in the context of preventing degenerative diseases, particularly cardiovascular diseases and cancer. The antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanism of action of polyphenols extends beyond the modulation of oxidative stress, as they are poorly absorbed from the digestive tract. The purpose of this study was to clarify the effects of polyphenols on the colonic environment, intestinal barrier function, and gut microbiota. We demonstrated that dietary polyphenols derived from aronia, haskap, and bilberry, markedly elevated the amount of fecal mucin and immunoglobulin A (IgA) as an intestinal barrier function and ameliorated the disturbance in gut microbiota caused by a high fat diet in rats. These results suggest that dietary polyphenols play a significant role in the prevention of degenerative diseases through improvement of the colonic environment without any absorption from the digestive tract. PMID:26566306

Advanced Separators for Lithium-Ion and Lithium-Sulfur Batteries: A Review of Recent Progress.

PubMed

Xiang, Yinyu; Li, Junsheng; Lei, Jiaheng; Liu, Dan; Xie, Zhizhong; Qu, Deyu; Li, Ke; Deng, Tengfei; Tang, Haolin

2016-11-09

Li-ion and Li-S batteries find enormous applications in different fields, such as electric vehicles and portable electronics. A separator is an indispensable part of the battery design, which functions as a physical barrier for the electrode as well as an electrolyte reservoir for ionic transport. The properties of the separators directly influence the performance of the batteries. Traditional polyolefin separators showed low thermal stability, poor wettability toward the electrolyte, and inadequate barrier properties to polysulfides. To improve the performance and durability of Li-ion and Li-S batteries, development of advanced separators is required. In this review, we summarize recent progress on the fabrication and application of novel separators, including the functionalized polyolefin separator, polymeric separator, and ceramic separator, for Li-ion and Li-S batteries. The characteristics, advantages, and limitations of these separators are discussed. A brief outlook for the future directions of the research in the separators is also provided. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancement of interfacial adhesion between starch and grafted poly(ε-caprolactone).

PubMed

Ortega-Toro, Rodrigo; Santagata, Gabriella; Gomez d'Ayala, Giovanna; Cerruti, Pierfrancesco; Talens Oliag, Pau; Chiralt Boix, M Amparo; Malinconico, Mario

2016-08-20

The use of a modified poly(ε-caprolactone) (gPCL) to enhance polymer miscibility in films based on thermoplastic starch (S) and poly(ε-caprolactone) is reported. PCL was functionalized by grafting with maleic anyhdride (MA) and/or glycidyl methacrylate (GMA) by reactive blending in a batch mixer. gPCL based materials were analysed in terms of their grafting degree, structural and thermal properties. Blends based on starch and PCL (wt. ratio 80:20) with including gPCL (0, 2.5 and 5wt.%), as a compatibilizer, were obtained by extrusion and compression moulding, and their structural, thermal, mechanical and barrier properties were investigated. Blends containing gPCL evidenced better interfacial adhesion between starch and PCL domains, as deduced from both structural (XRD, FTIR, SEM) and bulk properties (DSC, TGA). Moreover, grafted PCL-based compatibilizers greatly improved functional properties of S-PCL blend films, as pointed out from mechanical performance and higher barrier properties, valuable to meet the food packaging requirements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Designing solid-liquid interphases for sodium batteries

DOE PAGES

Choudhury, Snehashis; Wei, Shuya; Ozhabes, Yalcin; ...

2017-10-12

Secondary batteries based on earth-abundant sodium metal anodes are desirable for both stationary and portable electrical energy storage. Room-temperature sodium metal batteries are impractical today because morphological instability during recharge drives rough, dendritic electrodeposition. Chemical instability of liquid electrolytes also leads to premature cell failure as a result of parasitic reactions with the anode. Here we use joint density-functional theoretical analysis to show that the surface diffusion barrier for sodium ion transport is a sensitive function of the chemistry of solid–electrolyte interphase. In particular, we find that a sodium bromide interphase presents an exceptionally low energy barrier to ion transport,more » comparable to that of metallic magnesium. We evaluate this prediction by means of electrochemical measurements and direct visualization studies. These experiments reveal an approximately three-fold reduction in activation energy for ion transport at a sodium bromide interphase. Direct visualization of sodium electrodeposition confirms large improvements in stability of sodium deposition at sodium bromide-rich interphases.« less

Construction of multifunctional MoSe2 hybrid towards the simultaneous improvements in fire safety and mechanical property of polymer.

PubMed

Wang, Junling; Ma, Chao; Mu, Xiaowei; Cai, Wei; Liu, Longxiang; Zhou, Xia; Hu, Weizhao; Hu, Yuan

2018-06-15

Organic modification of MoSe 2 sheets is firstly achieved by Atherton-Todd reaction, aiming at the acquisition of multifunctional MoSe 2 hybrid. Simultaneous enhancements in fire safety and mechanical property of thermalplastic polyurethane (TPU) are obtained with the presence of this hybrid. Strong interfacial interactions between the functionalized MoSe 2 sheets and TPU can be obtained, making more efficient load transfer from the weak polymer chains to the robust sheets. Besides, more coherent barrier network may be formed in polymer matrix, restraining the diffusion of decomposed fragments and reducing the supply for combustion fuel. Consequently, the decreases in heat release are observed for polymer composites. Notably, the releases of toxic gases, such as HCN and CO, are also suppressed by this barrier network, resulting in the reductions in fire toxicity. This work may open a new door for the functionalization of MoSe 2 sheets and evoke significant developments in its promising applications. Copyright © 2018. Published by Elsevier B.V.

Improving the organization of palliative care: identification of barriers and facilitators in five European countries.

PubMed

van Riet Paap, Jasper; Vernooij-Dassen, Myrra; Brouwer, Frederike; Meiland, Franka; Iliffe, Steve; Davies, Nathan; Leppert, Wojciech; Jaspers, Birgit; Mariani, Elena; Sommerbakk, Ragni; Vissers, Kris; Engels, Yvonne

2014-10-16

Interventions to improve palliative care encounter challenges beyond the usual implementation problems because of palliative care's complex and changing character. In this study, we explored barriers and facilitators faced by health-care professionals in five European countries (England, Germany, Italy, Norway and the Netherlands) with regard to improving the organization of their palliative care service. Semi-structured individual and focus group interviews were conducted with purposefully selected health-care professionals. The constant comparative method was used to analyse the data. Professionals working in hospitals, hospices, nursing homes and primary care facilities who provide palliative care to adult patients were interviewed (n =40) or participated in ten focus group interviews (n =59). Barriers and facilitators were inductively grouped into 16 categories and arranged into five themes: innovation, individual professional level, group dynamics, organizational context and local political-economic context. Although the barriers and facilitators identified differed in scope, context, strength and provenance, they were shared by professionals from different European countries. This study identified barriers and facilitators to organizational change in palliative care. Some of these barriers and facilitators were experienced by professionals in almost all countries and are therefore prerequisites to change. Understanding the barriers to and facilitators of change will help tailor organizational improvements to the needs of individuals and organizations.

Outreach services to improve access to health care in South Africa: lessons from three community health worker programmes.

PubMed

Nxumalo, Nonhlanhla; Goudge, Jane; Thomas, Liz

2013-01-24

In South Africa, there are renewed efforts to strengthen primary health care and community health worker (CHW) programmes. This article examines three South African CHW programmes, a small local non-governmental organisation (NGO), a local satellite of a national NGO, and a government-initiated service, that provide a range of services from home-based care, childcare, and health promotion to assist clients in overcoming poverty-related barriers to health care. The comparative case studies, located in Eastern Cape and Gauteng, were investigated using qualitative methods. Thematic analysis was used to identify factors that constrain and enable outreach services to improve access to care. The local satellite (of a national NGO), successful in addressing multi-dimensional barriers to care, provided CHWs with continuous training focused on the social determinants of ill-health, regular context-related supervision, and resources such as travel and cell-phone allowances. These workers engaged with, and linked their clients to, agencies in a wide range of sectors. Relationships with participatory structures at community level stimulated coordinated responses from service providers. In contrast, an absence of these elements curtailed the ability of CHWs in the small NGO and government-initiated service to provide effective outreach services or to improve access to care. Significant investment in resources, training, and support can enable CHWs to address barriers to care by negotiating with poorly functioning government services and community participation structures.

ORAL DELIVERY OF L-ARGININE STIMULATES PROSTAGLANDIN-DEPENDENT SECRETORY DIARRHEA IN C. PARVUM INFECTED NEONATAL PIGLETS

PubMed Central

Gookin, Jody L.; Foster, Derek M.; Coccaro, Maria R.; Stauffer, Stephen H.

2008-01-01

Objectives To determine if oral supplementation with L-arginine could augment nitric oxide (NO) synthesis and promote epithelial defense in neonatal piglets infected with C. parvum. Methods Neonatal piglets were fed a liquid milk replacer and on day 3 of age infected or not with 108 C. parvum oocysts and the milk replacer supplemented with L-arginine or L-alanine. Milk consumption, body weight, fecal consistency, and oocyst excretion were recorded daily. On day 3 post-infection, piglets were euthanized, and serum concentration of NO metabolites and histological severity of villous atrophy and epithelial infection were quantified. Sheets of ileal mucosa were mounted in Ussing chambers for measurement of barrier function (transepithelial resistance (TER) and permeability) and short-circuit current (Isc; an indirect measurement of Cl− secretion in this tissue). Results C. parvum infected piglets had large numbers of epithelial parasites, villous atrophy, decreased barrier function, severe watery diarrhea, and failure to gain weight. L-arginine promoted synthesis of NO by infected piglets which was unaccompanied by improvement in severity of infection but rather promoted epithelial chloride secretion and diarrhea. Epithelial secretion by infected mucosa from L-arginine supplemented piglets was fully inhibited by the cyclooxygenase inhibitor indomethacin, indicating that prostaglandin synthesis was responsible for this effect. Conclusions Results of these studies demonstrate that provision of additional NO substrate in the form of L-arginine incites prostaglandin-dependent secretory diarrhea and does not promote epithelial defense or barrier function of C. parvum infected neonatal ileum. PMID:18223372

Effects of probiotics, probiotic DNA and the CpG oligodeoxynucleotides on ovalbumin-sensitized Brown-Norway rats via TLR9/NF-κB pathway.

PubMed

Zhong, Yan; Huang, Juan; Tang, Wenjing; Chen, Bing; Cai, Wei

2012-10-01

The aim of the study was to investigate the effect of living probiotics, probiotic DNA and the synthetic oligodeoxynucleotides containing CpG motifs (CpG-ODN) on both immune response and intestinal barrier function in ovalbumin-sensitized rat and the underlying mechanisms. Brown-Norway rats were orally sensitized with ovalbumin, and living probiotics, probiotic DNA extraction, synthetic CpG-ODN or non-CpG ODN control was administered. In the living probiotics, probiotic DNA and CpG-ODN groups, the allergic response was significantly inhibited, the Th1/Th2 cytokine balance was shifted away from Th2 side, the percentage of CD4(+) CD25(+high) Treg cells was increased, and the intestinal barrier function was improved. The levels of toll-like receptor (TLR) 9 mRNA and nuclear factor (NF)-κB activity, as well as the IκB-α phosphorylation (p-IκB-α) was significantly increased in these three intervention groups compared with the OVA-positive group, whereas no such effects were found in the non-CpG ODN control group. These data show that the probiotic genomic DNA and the synthetic CpG-ODN was comparable with living probiotics in preventing food allergic response by immune modulation and intestinal barrier function enhancement, and the activation of TLR9/NF-κB signal pathway might be involved in this process. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

The Gastrointestinal Microbiome and Musculoskeletal Diseases: A Beneficial Role for Probiotics and Prebiotics

PubMed Central

Vitetta, Luis; Coulson, Samantha; Linnane, Anthony W.; Butt, Henry

2013-01-01

Natural medicines are an attractive option for patients diagnosed with common and debilitating musculoskeletal diseases such as Osteoarthritis (OA) or Rheumatoid Arthritis (RA). The high rate of self-medication with natural products is due to (1) lack of an available cure and (2) serious adverse events associated with chronic use of pharmaceutical medications in particular non-steroidal anti-inflammatory drugs (NSAIDs) and high dose paracetamol. Pharmaceuticals to treat pain may disrupt gastrointestinal (GIT) barrier integrity inducing GIT inflammation and a state of and hyper-permeability. Probiotics and prebiotics may comprise plausible therapeutic options that can restore GIT barrier functionality and down regulate pro-inflammatory mediators by modulating the activity of, for example, Clostridia species known to induce pro-inflammatory mediators. The effect may comprise the rescue of gut barrier physiological function. A postulated requirement has been the abrogation of free radical formation by numerous natural antioxidant molecules in order to improve musculoskeletal health outcomes, this notion in our view, is in error. The production of reactive oxygen species (ROS) in different anatomical environments including the GIT by the epithelial lining and the commensal microbe cohort is a regulated process, leading to the formation of hydrogen peroxide which is now well recognized as an essential second messenger required for normal cellular homeostasis and physiological function. The GIT commensal profile that tolerates the host does so by regulating pro-inflammatory and anti-inflammatory GIT mucosal actions through the activity of ROS signaling thereby controlling the activity of pathogenic bacterial species. PMID:25437335

Identifying and Overcoming Barriers to Diabetes Management in the Elderly: An Intervention Study

DTIC Science & Technology

2010-06-01

Clinic al applicatio n of emerging sensor technologies in diabetes managemen t : consensus guidelines for continuous glucose monitoring (CGM). Diabetes...this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson...of a geriatric life specialis t is superior to usual care (with attention control) in improving glycemi c, functional, economic and qual ity of life

Improved stability and efficiency of perovskite solar cells with submicron flexible barrier films deposited in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rolston, Nicholas; Printz, Adam D.; Hilt, Florian

Here in this paper, we report on submicron organosilicate barrier films produced rapidly in air by a scalable spray plasma process that improves both the stability and efficiency of perovskite solar cells. The plasma is at sufficiently low temperature to prevent damage to the underlying layers. Oxidizing species and heat from the plasma improve device performance by enhancing both interfacial contact and the conductivity of the hole transporting layer. The thickness of the barrier films is tunable and transparent over the entire visible spectrum. The morphology and density of the barrier are shown to improve with the addition of amore » fluorine-based precursor. Devices with submicron coatings exhibited significant improvements in stability, maintaining 92% of their initial power conversion efficiencies after more than 3000 h in dry heat (85 °C, 25% RH) while also being resistant to degradation under simulated operational conditions of continuous exposure to light, heat, and moisture. X-ray diffraction measurements performed while heating showed the barrier film dramatically slows the formation of PbI 2. The barrier films also are compatible with flexible devices, exhibiting no signs of cracking or delamination after 10000 bending cycles on a 127 μm substrate with a bending radius of 1 cm.« less

Improved stability and efficiency of perovskite solar cells with submicron flexible barrier films deposited in air

DOE PAGES

Rolston, Nicholas; Printz, Adam D.; Hilt, Florian; ...

2017-10-27

Here in this paper, we report on submicron organosilicate barrier films produced rapidly in air by a scalable spray plasma process that improves both the stability and efficiency of perovskite solar cells. The plasma is at sufficiently low temperature to prevent damage to the underlying layers. Oxidizing species and heat from the plasma improve device performance by enhancing both interfacial contact and the conductivity of the hole transporting layer. The thickness of the barrier films is tunable and transparent over the entire visible spectrum. The morphology and density of the barrier are shown to improve with the addition of amore » fluorine-based precursor. Devices with submicron coatings exhibited significant improvements in stability, maintaining 92% of their initial power conversion efficiencies after more than 3000 h in dry heat (85 °C, 25% RH) while also being resistant to degradation under simulated operational conditions of continuous exposure to light, heat, and moisture. X-ray diffraction measurements performed while heating showed the barrier film dramatically slows the formation of PbI 2. The barrier films also are compatible with flexible devices, exhibiting no signs of cracking or delamination after 10000 bending cycles on a 127 μm substrate with a bending radius of 1 cm.« less

Enhanced Therapeutic Potential of Nano-Curcumin Against Subarachnoid Hemorrhage-Induced Blood-Brain Barrier Disruption Through Inhibition of Inflammatory Response and Oxidative Stress.

PubMed

Zhang, Zong-Yong; Jiang, Ming; Fang, Jie; Yang, Ming-Feng; Zhang, Shuai; Yin, Yan-Xin; Li, Da-Wei; Mao, Lei-Lei; Fu, Xiao-Yan; Hou, Ya-Jun; Fu, Xiao-Ting; Fan, Cun-Dong; Sun, Bao-Liang

2017-01-01

Curcumin and nano-curcumin both exhibit neuroprotective effects in early brain injury (EBI) after experimental subarachnoid hemorrhage (SAH). However, the mechanism that whether curcumin and its nanoparticles affect the blood-brain barrier (BBB) following SAH remains unclear. This study investigated the effect of curcumin and the poly(lactide-co-glycolide) (PLGA)-encapsulated curcumin nanoparticles (Cur-NPs) on BBB disruption and evaluated the possible mechanism underlying BBB dysfunction in EBI using the endovascular perforation rat SAH model. The results indicated that Cur-NPs showed enhanced therapeutic effects than that of curcumin in improving neurological function, reducing brain water content, and Evans blue dye extravasation after SAH. Mechanically, Cur-NPs attenuated BBB dysfunction after SAH by preventing the disruption of tight junction protein (ZO-1, occludin, and claudin-5). Cur-NPs also up-regulated glutamate transporter-1 and attenuated glutamate concentration of cerebrospinal fluid following SAH. Moreover, inhibition of inflammatory response and microglia activation both contributed to Cur-NPs' protective effects. Additionally, Cur-NPs markedly suppressed SAH-mediated oxidative stress and eventually reversed SAH-induced cell apoptosis in rats. Our findings revealed that the strategy of using Cur-NPs could be a promising way in improving neurological function in EBI after experimental rat SAH.

Theranostic quantum dots for crossing blood–brain barrier in vitro and providing therapy of HIV-associated encephalopathy

PubMed Central

Xu, Gaixia; Mahajan, Supriya; Roy, Indrajit; Yong, Ken-Tye

2013-01-01

The blood–brain barrier (BBB) is a complex physiological checkpoint that restricts the free diffusion of circulating molecules from the blood into the central nervous system. Delivering of drugs and other active agents across the BBB is one of the major technical challenges faced by scientists and medical practitioners. Therefore, development of novel methodologies to address this challenge holds the key for both the diagnosis and treatment of brain diseases, such as HIV-associated encephalopathy. Bioconjugated quantum dots (QDs) are excellent fluorescent probes and nano-vectors, being designed to transverse across the BBB and visualize drug delivery inside the brain. This paper discusses the use of functionalized QDs for crossing the blood–brain barrier and treating brain disease. We highlight the guidelines for using in vitro BBB models for brain disease studies. The theranostic QDs offers a strategy to significantly improve the effective dosages of drugs to transverse across the BBB and orientate to the targets inside the brain. PMID:24298256

Role of information and communication technology in promoting oral health at residential aged care facilities.

PubMed

Adebayo, Bola; Durey, Angela; Slack-Smith, Linda M

2017-07-01

Information and communication technology (ICT) can provide knowledge and clinical support to those working in residential aged care facilities (RACFs). This paper aims to: (1) review literature on ICT targeted at residents, staff and external providers in RACFs including general practitioners, dental and allied health professionals on improving residents' oral health; (2) identify barriers and enablers to using ICT in promoting oral health at RACFs; and (3) investigate evidence of effectiveness of these approaches in promoting oral health. Findings from this narrative literature review indicate that ICT is not widely used in RACFs, with barriers to usage identified as limited training for staff, difficulties accessing the Internet, limited computer literacy particularly in older staff, cost and competing work demands. Residents also faced barriers including impaired cognitive and psychosocial functioning, limited computer literacy and Internet use. Findings suggest that more education and training in ICT to upskill staff and residents is needed to effectively promote oral health through this medium.

Consumer Engagement in Health IT: Distinguishing Rhetoric from Reality

PubMed Central

Gold, Marsha; Hossain, Mynti; Mangum, Amy

2015-01-01

Rationale: Policymakers want health information technology (health IT) to support consumer engagement to help achieve national health goals. In this paper, we review the evidence to compare the rhetoric with the reality of current practice. Current Reality and Barriers: Our environmental scan shows that consumer demand exists for electronic access to personal health information, but that technical and system or political barriers still limit the value of the available information and its potential benefits. Conclusions and Policy Implications: There is a gap between current reality and the goals for consumer engagement. Actions that may help bridge this gap include: (1) resolving technical barriers to health information exchange (HIE); (2) developing more consumer-centric design and functionality; (3) reinforcing incentives that attract provider support by showing that consumer engagement is in their interest; and (4) building a stronger empirical case to convince decision makers that consumer engagement will lead to better care, improved health outcomes, and lower costs. PMID:26665120

Development of an mHealth Intervention (iSTEP) to Promote Physical Activity among People Living with HIV.

PubMed

Montoya, Jessica L; Wing, David; Knight, Adam; Moore, David J; Henry, Brook L

2015-01-01

A randomized controlled trial is being conducted in the United States to test the efficacy of a personalized interactive mobile health intervention (iSTEP) designed to increase physical activity (PA) and improve neurocognitive functioning among HIV-positive persons. This article describes an initial qualitative study performed to develop iSTEP for the HIV-positive population, including assessment of PA barriers and facilitators. Two focus groups, with 9 and 12 unique HIV-positive individuals, respectively, were administered to evaluate barriers limiting PA and potential iSTEP content created to encourage greater PA. Group discussions revealed prominent PA barriers, including HIV symptoms (neuropathy, lipoatrophy), antiretroviral medication effects, and fatigue; significant PA facilitators included self-monitoring and family support. Participants provided feedback on strategies to increase PA and expressed positive support for a mobile intervention adapted to personal priorities. These findings will assist the development of novel PA interventions focused on treating the epidemic of HIV-associated neurocognitive disorders. © The Author(s) 2015.

Mixed microencapsulation of rat primary hepatocytes and Sertoli cells improves the metabolic function in a D-galactosamine and lipopolysaccharide-induced rat model of acute liver failure.

PubMed

Zheng, Ming-Hua; Lin, Hai-Long; Qiu, Li-Xin; Cui, Yao-Li; Sun, Qing-Feng; Chen, Yong-Ping

2009-01-01

Hepatocyte transplantation is an alternative to transplantation of the whole liver. Compared with xenogeneic hepatocytes, primary hepatocytes have some advantages, such as a more powerful function and a smaller frequency of rejection caused by the host. Cell microencapsulation prevents direct access of host cells to the graft but cannot impede transfer of transplant-derived peptides, which can cross the physical barrier. Sertoli cells are central to the immune privilege demonstrated in the testis, and their actions have been utilized to protect cell transplants. Co-microencapsulating Sertoli cells with HepG2 cells has proved to be a valuable strategy in hepatocyte transplantation. Thus mixed microcapsules of primary rat hepatocytes and primary Sertoli cells may improve metabolic function in a d-galactosamine and lipopolysaccharide-induced rat model of acute liver failure.

'Shall We Dance'? Older Adults' Perspectives on the Feasibility of a Dance Intervention for Cognitive Function.

PubMed

Thøgersen-Ntoumani, Cecilie; Papathomas, Anthony; Foster, Jonathan; Quested, Eleanor; Ntoumanis, Nikos

2017-12-28

We explored perceptions of social dance as a possible intervention to improve cognitive functioning in older adults with subjective memory complaints. Thirty participants (19 female; M age = 72.6; SD=8.2) took part in the study. This included 21 participants who had self-reported subjective memory complaints and 9 spouses who noticed spousal memory loss. Semi-structured interviews were conducted and thematic analysis was used to analyze the data. Three main themes were constructed: 1) dance seen as a means of promoting social interaction; 2) chronic illness as a barrier and facilitator to participation; 3) social dance representing nostalgic connections to the past. Overall, the participants were positive about the potential attractiveness of social dance to improve cognitive and social functioning and other aspects of health. It is important in future research to examine the feasibility of a social dance intervention among older adults with subjective memory complaints.

Airway Epithelial Barrier Dysfunction in Chronic Obstructive Pulmonary Disease: Role of Cigarette Smoke Exposure.

PubMed

Aghapour, Mahyar; Raee, Pourya; Moghaddam, Seyed Javad; Hiemstra, Pieter S; Heijink, Irene H

2018-02-01

The epithelial lining of the airway forms the first barrier against environmental insults, such as inhaled cigarette smoke, which is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). The barrier is formed by airway epithelial junctions, which are interconnected structures that restrict permeability to inhaled pathogens and environmental stressors. Destruction of the epithelial barrier not only exposes subepithelial layers to hazardous agents in the inspired air, but also alters the normal function of epithelial cells, which may eventually contribute to the development of COPD. Of note, disruption of epithelial junctions may lead to modulation of signaling pathways involved in differentiation, repair, and proinflammatory responses. Epithelial barrier dysfunction may be particularly relevant in COPD, where repeated injury by cigarette smoke exposure, pathogens, inflammatory mediators, and impaired epithelial regeneration may compromise the barrier function. In the current review, we discuss recent advances in understanding the mechanisms of barrier dysfunction in COPD, as well as the molecular mechanisms that underlie the impaired repair response of the injured epithelium in COPD and its inability to redifferentiate into a functionally intact epithelium.

Universal potential-barrier penetration by initially confined wave packets

NASA Astrophysics Data System (ADS)

Granot, Er'El; Marchewka, Avi

2007-07-01

The dynamics of an initially sharp-boundary wave packet in the presence of an arbitrary potential barrier is investigated. It is shown that the penetration through the barrier is universal in the sense that it depends only on the values of the wave function and its derivatives at the boundary. The dependence on the derivatives vanishes at long distances from the barrier, where the dynamics is governed solely by the initial value of the wave function at the boundary.

ATP-binding cassette transporters in reproduction: a new frontier

PubMed Central

Bloise, E.; Ortiga-Carvalho, T.M.; Reis, F.M.; Lye, S.J.; Gibb, W.; Matthews, S.G.

2016-01-01

BACKGROUND The transmembrane ATP-binding cassette (ABC) transporters actively efflux an array of clinically relevant compounds across biological barriers, and modulate biodistribution of many physiological and pharmacological factors. To date, over 48 ABC transporters have been identified and shown to be directly and indirectly involved in peri-implantation events and fetal/placental development. They efflux cholesterol, steroid hormones, vitamins, cytokines, chemokines, prostaglandins, diverse xenobiotics and environmental toxins, playing a critical role in regulating drug disposition, immunological responses and lipid trafficking, as well as preventing fetal accumulation of drugs and environmental toxins. METHODS This review examines ABC transporters as important mediators of placental barrier functions and key reproductive processes. Expression, localization and function of all identified ABC transporters were systematically reviewed using PubMed and Google Scholar websites to identify relevant studies examining ABC transporters in reproductive tissues in physiological and pathophysiological states. Only reports written in English were incorporated with no restriction on year of publication. While a major focus has been placed on the human, extensive evidence from animal studies is utilized to describe current understanding of the regulation and function of ABC transporters relevant to human reproduction. RESULTS ABC transporters are modulators of steroidogenesis, fertilization, implantation, nutrient transport and immunological responses, and function as ‘gatekeepers’ at various barrier sites (i.e. blood-testes barrier and placenta) against potentially harmful xenobiotic factors, including drugs and environmental toxins. These roles appear to be species dependent and change as a function of gestation and development. The best-described ABC transporters in reproductive tissues (primarily in the placenta) are the multidrug transporters p-glycoprotein and breast cancer-related protein, the multidrug resistance proteins 1 through 5 and the cholesterol transporters ABCA1 and ABCG1. CONCLUSIONS The ABC transporters have various roles across multiple reproductive tissues. Knowledge of efflux direction, tissue distribution, substrate specificity and regulation of the ABC transporters in the placenta and other reproductive tissues is rapidly expanding. This will allow better understanding of the disposition of specific substrates within reproductive tissues, and facilitate development of novel treatments for reproductive disorders as well as improved approaches to protecting the developing fetus. PMID:26545808

Permselective SPEEK/Nafion Composite-Coated Separator as a Potential Polysulfide Crossover Barrier Layer for Li-S Batteries.

PubMed

Babu, Dasari Bosu; Giribabu, Krishnan; Ramesha, Kannadka

2018-06-13

Minimizing the shuttle effect by constraining polysulfides to the cathode compartment and activating the passive layer between cathode and separator are highly important for improving the Li-S cell performance, Coulombic efficiency, and cycle life. Here, we report a submicron thin coating of permselective sulfonated poly(ether ether ketone) (SPEEK) composite layer on the separator that would reduce polysulfide crossover, imparting a significant improvement in cycle life. It is observed that SPEEK increases the stability, and adding Nafion improves the capacity value. Among different ratios of Nafion and SPEEK (25:75, 50:50, and 75:25), the composite with a SPEEK/Nafion ratio of 50:50 showed a controlled shuttle effect with a stable cell capacity of 600 mA h g -1 up to 300 cycles. This modified separator with permselective coatings not only reduces the polysulfide shuttle but also improves the wettability and interfacial contact, which results in an improvement in average cell potential and lithium diffusivity. It is demonstrated here that the combination of functional (ionomer coating on separator) and nonfunctional (extra cathode layer) physical barriers effectively suppresses the polysulfide crossover and improves the electrochemical performance of Li-S batteries. The cell shows an initial capacity of 1300 mA h g -1 and a capacity retention of 650 mA h g -1 over 500 cycles with a 6 mg/cm 2 sulfur loading.

Patterns of perceived barriers to medical care in older adults: a latent class analysis.

PubMed

Thorpe, Joshua M; Thorpe, Carolyn T; Kennelty, Korey A; Pandhi, Nancy

2011-08-03

This study examined multiple dimensions of healthcare access in order to develop a typology of perceived barriers to healthcare access in community-dwelling elderly. Secondary aims were to define distinct classes of older adults with similar perceived healthcare access barriers and to examine predictors of class membership to identify risk factors for poor healthcare access. A sample of 5,465 community-dwelling elderly was drawn from the 2004 wave of the Wisconsin Longitudinal Study. Perceived barriers to healthcare access were measured using items from the Group Health Association of America Consumer Satisfaction Survey. We used latent class analysis to assess the constellation of items measuring perceived barriers in access and multinomial logistic regression to estimate how risk factors affected the probability of membership in the latent barrier classes. Latent class analysis identified four classes of older adults. Class 1 (75% of sample) consisted of individuals with an overall low level of risk for perceived access problems (No Barriers). Class 2 (5%) perceived problems with the availability/accessibility of healthcare providers such as specialists or mental health providers (Availability/Accessibility Barriers). Class 3 (18%) perceived problems with how well their providers' operations arise organized to accommodate their needs and preferences (Accommodation Barriers). Class 4 (2%) perceived problems with all dimension of access (Severe Barriers). Results also revealed that healthcare affordability is a problem shared by members of all three barrier groups, suggesting that older adults with perceived barriers tend to face multiple, co-occurring problems. Compared to those classified into the No Barriers group, those in the Severe Barrier class were more likely to live in a rural county, have no health insurance, have depressive symptomatology, and speech limitations. Those classified into the Availability/Accessibility Barriers group were more likely to live in rural and micropolitan counties, have depressive symptomatology, more chronic conditions, and hearing limitations. Those in the Accommodation group were more likely to have depressive symptomatology and cognitive limitations. The current study identified a typology of perceived barriers in healthcare access in older adults. The identified risk factors for membership in perceived barrier classes could potentially assist healthcare organizations and providers with targeting polices and interventions designed to improve access in their most vulnerable older adult populations, particularly those in rural areas, with functional disabilities, or in poor mental health.

Two-color infrared detector

DOEpatents

Klem, John F; Kim, Jin K

2014-05-13

A two-color detector includes a first absorber layer. The first absorber layer exhibits a first valence band energy characterized by a first valence band energy function. A barrier layer adjoins the first absorber layer at a first interface. The barrier layer exhibits a second valence band energy characterized by a second valence band energy function. The barrier layer also adjoins a second absorber layer at a second interface. The second absorber layer exhibits a third valence band energy characterized by a third valence band energy function. The first and second valence band energy functions are substantially functionally or physically continuous at the first interface and the second and third valence band energy functions are substantially functionally or physically continuous at the second interface.

Associations between health-related quality of life and financial barriers to care among women veterans and women non-veterans.

PubMed

Shen, Chan; Sambamoorthi, Usha

2012-01-01

The authors of this study examined the association between health-related quality of life and financial barriers to care, defined as not getting the needed care due to cost considerations. To better understand health-related quality of life among women veterans, the authors compared women veterans to women non-veterans. The authors conducted cross-sectional analyses using data from the 2009 Behavioral Risk Factor Surveillance System survey. The authors assessed four health-related quality of life measures: (1) general health; (2) physical health; (3) mental health; and (4) functional status. The authors performed multinomial logistic regressions to examine the relationship between financial barriers to receiving healthcare and health-related quality of life measures after controlling for other independent variables. The authors included women veterans not in active military duty (N = 3,747) and a matched sample of women non-veterans (N = 3,747), selected using a propensity score method so that they would have distributions of demographic and socioeconomic characteristics similar to those of the veterans. Overall, 14% of women reported financial barriers. Women who reported financial barriers to receiving healthcare were more likely to have poor health-related quality of life in all four dimensions than those who did not report such barriers. Compared to women non-veterans, women veterans did not differ in reported financial barriers but were more likely to report poor health-related quality of life. Reporting financial barriers to receiving needed healthcare was significantly associated with poor health-related quality of life among women. Veteran status was also significantly associated with poor health-related quality of life. These findings suggest the need for healthcare policy makers and practitioners to align emerging new models of healthcare delivery to improve health-related quality of life for women veterans.

What helps or hinders the transformation from a major tertiary center to a major trauma center? Identifying barriers and enablers using the Theoretical Domains Framework.

PubMed

Roberts, Neil; Lorencatto, Fabiana; Manson, Joanna; Brundage, Susan I; Jansen, Jan O

2016-03-12

Major Trauma Centers (MTCs), as part of a trauma system, improve survival and functional outcomes from injury. Developing such centers from current teaching hospitals is likely to generate diverse beliefs amongst staff. These may act as barriers or enablers. Prior identification of these may make the service development process more efficient. The importance of applying theory to systematically identify barriers and enablers to changing clinical practice in emergency medicine has been emphasized. This study systematically explored theory-based barriers and enablers towards implementing the transformation of a tertiary hospital into a MTC. Our goal was to demonstrate the use of a replicable method to identify targets that could be addressed to achieve a successful transformation from an organization evolved to provide a particular type of clinical care into a clinical system with different demands, requirements and expectations. The Theoretical Domains Framework (TDF) is a tool designed to elicit and analyze beliefs affecting behavior. Semi-structured interviews based around the TDF were conducted in a major tertiary hospital in Scotland due to become a MTC with a purposive sample of major stakeholders including clinicians and nurses from specialties involved in trauma care, clinical managers and administration. Belief statements were identified through qualitative analysis, and assessed for importance according to prevalence, discordance and evidence base. 1728 utterances were recorded and coded into 91 belief statements. 58 were classified as important barriers/enablers. There were major concerns about resource demands, with optimism conditional on these being met. Distracting priorities abound within the Emergency Department. Better communication is needed. Staff motivation is high and they should be engaged in skills development and developing performance improvement processes. This study presents a systematic and replicable method of identifying theory-based barriers and enablers towards complex service development. It identifies multiple barriers/enablers that may serve as a basis for developing an implementation intervention to enhance the development of MTCs. This method can be used to address similar challenges in developing specialist centers or implementing clinical practice change in emergency care across both developing and developed countries.

Social workers' perceptions of barriers to interpersonal therapy implementation for treating postpartum depression in a primary care setting in Israel.

PubMed

Bina, Rena; Barak, Adi; Posmontier, Barbara; Glasser, Saralee; Cinamon, Tali

2018-01-01

Research on evidence-based practice (EBP) implementation in social work often neglects to include evaluation of application barriers. This qualitative study examined social workers' perspectives of provider- and organisational-related barriers to implementing a brief eight-session interpersonal therapy (IPT) intervention, a time-limited EBP that addresses reducing depressive symptoms and improving interpersonal functioning. Implementation took place in a primary care setting in Israel and was aimed at treating women who have postpartum depression (PPD) symptoms. Using purposeful sampling, 25 primary care licensed social workers were interviewed between IPT training and implementation regarding their perceived barriers to implementing IPT in practice. Data analysis was facilitated using a phenomenological approach, which entails identifying the shared themes and shared experiences of research participants regarding barriers to implementing IPT. Three themes emerged from the analysis of interviews: Perceived lack of flexibility of IPT intervention in comparison with more familiar methods social workers previously applied, specifically regarding the number of sessions and therapeutic topics included in the IPT protocol; insecurity and hesitance to gain experience with a new method of intervention; and organisational barriers, including difficulties with referrals, the perception of HMOs as health facilities not suitable for therapy, and time constraints. Addressing perceived barriers of social workers toward implementing EBPs, such as IPT for postpartum depression, during the training phase is crucial for enabling appropriate implementation. Future training should include examining practitioners' attitudes toward implementation of EBPs, as part of standardised training protocols. © 2017 John Wiley & Sons Ltd.

Advanced Thermal Barrier and Environmental Barrier Coating Development at NASA GRC

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Robinson, Craig

2017-01-01

This presentation summarizes NASA's advanced thermal barrier and environmental barrier coating systems, and the coating performance improvements that has recently been achieved and documented in laboratory simulated rig test conditions. One of the emphases has been placed on the toughness and impact resistance enhancements of the low conductivity, defect cluster thermal barrier coating systems. The advances in the next generation environmental barrier coatings for SiCSiC ceramic matrix composites have also been highlighted, particularly in the design of a new series of oxide-silicate composition systems to be integrated with next generation SiC-SiC turbine engine components for 2700F coating applications. Major technical barriers in developing the thermal and environmental barrier coating systems are also described. The performance and model validations in the rig simulated turbine combustion, heat flux, steam and calcium-magnesium-aluminosilicate (CMAS) environments have helped the current progress in improved temperature capability, environmental stability, and long-term fatigue-environment system durability of the advanced thermal and environmental barrier coating systems.

Crossing safety barriers: influence of children's morphological and functional variables.

PubMed

Cordovil, Rita; Vieira, Filomena; Barreiros, João

2012-05-01

Thirty-three children between 3 and 6 years of age were asked to climb four different types of safety barriers. Morphological and functional variables of the children, which were expected to influence climbing or passing through skills, were collected. The influence of those variables on children's success rate and time to cross was tested. No barrier offered a total restraining efficacy. The horizontal bars barrier was crossed by 97% of the children. In the group of children that succeeded in crossing the four barriers, mean time to cross the most difficult barrier was 15 s. Age was the best predictor for success in crossing most barriers but morphology and strength were important predictors of time to cross. The influence of anthropometric variables in time to cross was dependent upon the characteristics of the barrier. A good design of safety barriers should consider children's age, morphology and strength. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Environmental factors and their role in community integration after spinal cord injury.

PubMed

Lysack, Cathy; Komanecky, Marie; Kabel, Allison; Cross, Katherine; Neufeld, Stewart

2007-01-01

The International Classification of Functioning, Disability and Health (ICF) model presents an opportunity to better understand previously neglected longterm social outcomes after traumatic spinal cord injury (SCI), especially the experience of participation. The study explored the relationship between perceived environmental barriers and perceived community integration (a participation proxy) in a sample of adults with traumatic SCI. The study interviewed African American and White women and men (n = 136) who had lived with SCI for an average of 11.5 years. Participants reported environmental barriers at twice the level indicated by previous studies; the natural environment and the policies of government were the most problematic. Levels of community integration were also high. Data suggest a significant relationship (p < .01) between perceived environmental barriers and community integration for adults with SCI, providing support for the ICF model. Improved measures and more sophisticated concepts and theories are needed to explicate the relationship between environmental factors and participation concepts in the ICE With respect to practice, occupational therapists need to be aware that removal of environmental barriers is only a first step in the more complex effort to facilitate optimal community integration after SCI.

Reaction of hydrogen with Ag(111): binding states, minimum energy paths, and kinetics.

PubMed

Montoya, Alejandro; Schlunke, Anna; Haynes, Brian S

2006-08-31

The interaction of atomic and molecular hydrogen with the Ag(111) surface is studied using periodic density functional total-energy calculations. This paper focuses on the site preference for adsorption, ordered structures, and energy barriers for H diffusion and H recombination. Chemisorbed H atoms are unstable with respect to the H(2) molecule in all adsorption sites below monolayer coverage. The three-hollow sites are energetically the most favorable for H chemisorption. The binding energy of H to the surface decreases slightly up to one monolayer, suggesting a small repulsive H-H interaction on nonadjacent sites. Subsurface and vacancy sites are energetically less favorable for H adsorption than on-top sites. Recombination of chemisorbed H atoms leads to the formation of gas-phase H(2) with no molecular chemisorbed state. Recombination is an exothermic process and occurs on the bridge site with a pronounced energy barrier. This energy barrier is significantly higher than that inferred from experimental temperature-programmed desorption (TPD) studies. However, there is significant permeability of H atoms through the recombination energy barrier at low temperatures, thus increasing the rate constant for H(2) desorption due to quantum tunneling effects, and improving the agreement between experiment and theory.

A Review of Podocyte Biology.

PubMed

Garg, Puneet

2018-05-31

Podocyte biology is a developing science that promises to help improve understanding of the mechanistic nature of multiple diseases associated with proteinuria. Proteinuria in nephrotic syndrome has been linked to mechanistic dysfunctions in the renal glomerulus involving the function of podocyte epithelial cells, including podocyte foot process effacement. Developments in imaging technology are improving knowledge of the detailed structure of the human renal glomerulus and cortex. Podocyte foot processes attach themselves to the glomerular capillaries at the glomerular basement membrane (GBM) forming intercellular junctions that form slit diaphragm filtration barriers that help maintain normal renal function. Damage in this area has been implicated in glomerular disease. Injured podocytes undergo effacement whereby they lose their structure and spread out, leading to a reduction in filtration barrier function. Effacement is typically associated with the presence of proteinuria in focal segmental glomerulosclerosis, minimal change disease, and diabetes. It is thought to be due to a breakdown in the actin cytoskeleton of the foot processes, complex contractile apparatuses that allow podocytes to dynamically reorganize according to changes in filtration requirements. The process of podocyte depletion correlates with the development of glomerular sclerosis and chronic kidney disease. Focal adhesion complexes that interact with the underlying GBM bind the podocytes within the glomerular structure and prevent their detachment. Key Messages: Knowledge of glomerular podocyte biology is helping to advance our understanding of the science and mechanics of the glomerular filtering process, opening the way to a variety of new potential applications for clinical targeting. © 2018 S. Karger AG, Basel.

Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

2012-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

Improved performance of In0.83Ga0.17As/InP photodetectors through modifying the position of In0.66Ga0.34As/InAs superlattice electron barrier

NASA Astrophysics Data System (ADS)

Shi, Yan-hui; Zhang, Yong-gang; Ma, Ying-jie; Gu, Yi; Chen, Xing-you; Gong, Qian; Du, Ben; Zhang, Jian; Zhu, Yi

2018-03-01

The performance of wavelength extended In0.83Ga0.17As/InP photodetectors has been improved notably through modifying the position of electron barriers in absorption layer. In order to fully utilize the diffusion component of the photocurrent, the In0.66Ga0.34As/InAs superlattice electron barrier is moved to the edge of the depletion region. Enhanced peak photo responsivity up to 0.84 A/W is realized, which raises 24% compared to that of a reference detector with the superlattice barrier in the middle of the absorber. The dark current slightly increases by 25% at room temperature while decreases by more than an order of magnitude at 150 K, resulting in about 10% or more than twofold improvements for the detectivity, respectively. The results suggest that optimized barrier position is a necessity for barrier-type photodetectors to achieve better performances.

Tight junction proteins contribute to barrier properties in human pleura.

PubMed

Markov, Alexander G; Voronkova, Maria A; Volgin, George N; Yablonsky, Piotr K; Fromm, Michael; Amasheh, Salah

2011-03-15

The permeability of pleural mesothelium helps to control the volume and composition of the liquid lubricating pleural surfaces. Information on pleural barrier function in health and disease, however, is scarce. Tissue specimens of human pleura were mounted in Ussing chambers for measurement of transmesothelial resistance. Expression of tight junction (TJ) proteins was studied by Western blots and immune fluorescence confocal microscopy. Both visceral and parietal pleura showed barrier properties represented by transmesothelial resistance. Occludin, claudin-1, -3, -5, and -7, were detected in visceral pleura. In parietal pleura, the same TJ proteins were detected, except claudin-7. In tissues from patients with pleural inflammation these tightening claudins were decreased and in visceral pleura claudin-2, a paracellular channel former, became apparent. We report that barrier function in human pleura coincides with expression of claudins known to be key determinants of epithelial barrier properties. In inflamed tissue, claudin expression indicates a reduced barrier function. Copyright © 2010 Elsevier B.V. All rights reserved.

Enhanced transport of nanocage stabilized pure nanodrug across intestinal epithelial barrier mimicking Listeria monocytogenes.

PubMed

Xia, Dengning; Tao, Jinsong; He, Yuan; Zhu, Quanlei; Chen, Dan; Yu, Miaorong; Cui, Fude; Gan, Yong

2015-01-01

Ligand grafted nanoparticles have been shown to enhance drug transport across epithelium barrier and are expected to improve drug delivery. However, grafting of these ligands to the surface of pure nanodrug, i.e., nanocrystals (NCs), is a critical challenge due to the shedding of ligands along with the stabilizer upon high dilution or dissolving of the drug. Herein, a non-sheddable nanocage-like stabilizer was designed by covalent cross-linking of poly(acrylic acid)-b-poly(methyl acrylate) on drug nanocrystal surface, and a ligand, wheat germ agglutinin (WGA), was successfully anchored to the surface of itraconazole (ITZ) NCs by covalent conjugation to the nanocage (WGA-cage-NCs). The cellular study showed that large amount of WGA-cage-NCs were adhered to Caco-2 cell membrane, and invaded into cells, resulting in a higher drug uptake than that of ordinary NCs (ONCs). After oral administration to rats, WGA-cage-NC were largely accumulated on the apical side of epithelium cells, facilitating drug diffusing across epithelium barrier. Interestingly, WGA-cage-NCs were capable of invading rat intestinal villi and reaching to lamina propria by transcytosis across goblet cells, which behaved like a foodborne pathogen, Listeria monocytogenes. The WGA-cage-NCs showed an improved oral bioavailability, which was 17.5- and 2.41-folds higher than that of coarse crystals and ONCs, respectively. To our best knowledge, this may represent the first report that a functional ligand was successfully anchored to the surface of pure nanodrug by using a cage-like stabilizer, showing unique biological functions in gastrointestinal tract and having an important significance in oral drug delivery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diadenosine tetraphosphate induces tight junction disassembly thus increasing corneal epithelial permeability.

PubMed

Loma, P; Guzman-Aranguez, A; Pérez de Lara, M J; Pintor, J

2015-02-01

Here, we have studied the effects of the dinucleotide P(1), P(4)-Di (adenosine-5') tetraphosphate (Ap4 A) on corneal barrier function conferred by the tight junction (TJ) proteins and its possible involvement in ocular drug delivery and therapeutic efficiency. Experiments in vitro were performed using human corneal epithelial cells (HCLEs) treated with Ap4 A (100 μM) for 5 min. Western blot analysis and transepithelial electrical resistance (TEER) were performed to study the TJ protein levels and barrier function respectively. Intracellular pathways involved were determined using an ERK inhibitor and P2Y(2) receptor siRNAs. In in vivo assays with New Zealand rabbits, TJ integrity was examined by zonula occludens-1 (ZO-1) staining. The hypotensive compound 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT) was used to assess improved delivery, measuring its levels by HPLC and measuring intraocular pressure using 5-MCA-NAT, P2Y receptor antagonists and P2Y2 siRNAs. Two hours after Ap4 A pretreatment, TJ protein levels in HCLE cells were reduced around 40% compared with control. TEER values were significantly reduced at 2 and 4 h (68 and 52% respectively). TJ reduction and ERK activation were blocked by the ERK inhibitor U012 and P2Y(2) siRNAs. In vivo, topical application of Ap4 A disrupted ZO-1 membrane distribution. 5-MCA-NAT levels in the aqueous humour were higher when Ap4 A was previously instilled and its hypotensive effect was also increased. This action was reversed by P2Y receptor antagonists and P2Y(2) siRNA. Ap4 A increased corneal epithelial barrier permeability. Its application could improve ocular drug delivery and consequently therapeutic efficiency. © 2014 The British Pharmacological Society.

Effects of simvastatin on CAT-1-mediated arginine transport and NO level under high glucose conditions in conditionally immortalized rat inner blood-retinal barrier cell lines (TR-iBRB).

PubMed

Tun, Temdara; Kang, Young-Sook

2017-05-01

Hyperglycemia causes the breakdown of the blood-retinal barrier by impairing endothelial nitric oxide synthase (eNOS) function. Statins have many pleiotropic effects such as improving endothelial barrier permeability and increasing eNOS mRNA stability. The objective of this study was to determine effect of simvastatin on l-arginine transport and NO production under high-glucose conditions in conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB). Changes in l-arginine transport uptake and, expression levels of cationic amino acid transporter 1 (CAT-1) and eNOS mRNA were investigated after pre-treatment with simvastatin and NOS inhibitors (l-NMMA and l-NAME) under high-glucose conditions using TR-iBRB, an in vitro model of iBRB. The NO level released from TR-iBRB cells was examined using Griess reagents. Under high glucose conditions, [ 3 H]l-arginine uptake was decreased in TR-iBRB cells. Simvastatin pretreatment elevated [ 3 H]l-arginine uptake, the expression levels of CAT-1 and eNOS mRNA, and NO production under high-glucose conditions. Moreover, the co-treatment with simvastatin and NOS inhibitors reduced [ 3 H]l-arginine uptake compared to pretreatment with simvastatin alone. Our results suggest that, in the presence of high-glucose levels, increased l-arginine uptake due to simvastatin treatment was associated with increased CAT-1 and eNOS mRNA levels, leading to higher NO production in TR-iBRB cells. Thus, simvastatin might be a good modulator for diabetic retinopathy therapy by increasing of the l-arginine uptake and improving endothelial function in retinal capillary endothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of La/W ratio on electrical conductivity of lanthanum tungstate with high La/W ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojo, Gen; Shono, Yohei; Ushiyama, Hiroshi

The proton-conducting properties of lanthanum tungstates (LWOs) with high La/W ratios were investigated using electrochemical measurements and quantum chemical calculations. Single phases of LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized by high-temperature sintering at around 1700 °C. The electrical conductivity of LWO increased with increasing La/W ratio in the single-phase region. The LWO synthesized at the optimum sintering temperature and time, and with the optimum La/W ratio gave the maximum conductivity, i.e., 2.7×10{sup −3} S cm{sup −1} with La/W=6.7 at 500 °C. Density functional theory calculations, using the nudged elastic band method, were performed to investigate the proton diffusionmore » barrier. The results suggest that the proton diffusion paths around La sites have the lowest proton diffusion barrier. These findings improve our understanding of LWO synthesis and the proton-conducting mechanism and provide a strategy for improving proton conduction in LWOs. - Graphical abstract: The LWOs with high La/W ratios were synthesized for the first time. The optimum La/W ratio gave the maximum conductivity with La/W=6.7 at 500 °C. The proton diffusion paths were also considered with density functional theory calculations. - Highlights: • The proton-conducting properties of lanthanum tungstates (LWOs) were investigated. • Single phase LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized successfully. • LWOs with the high La/W ratios showed high proton conductivity. • The DFT calculation suggested the lowest proton diffusion barrier in the path around La sites.« less

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

NASA Technical Reports Server (NTRS)

Amos, D. J.

1977-01-01

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Linking Cultural Competence to Functional Life Outcomes in Mental Health Care Settings.

PubMed

Michalopoulou, Georgia; Falzarano, Pamela; Butkus, Michael; Zeman, Lori; Vershave, Judy; Arfken, Cynthia

2014-01-01

Minorities in the United States have well-documented health disparities. Cultural barriers and biases by health care providers may contribute to lower quality of services which may contribute to these disparities. However, evidence linking cultural competency and health outcomes is lacking. This study, part of an ongoing quality improvement effort, tested the mediation hypothesis that patients' perception of provider cultural competency indirectly influences patients' health outcomes through process of care. Data were from patient satisfaction surveys collected in seven mental health clinics (n=94 minority patients). Consistent with our hypothesis, patients' perception of clinicians' cultural competency was indirectly associated with patients' self-reported improvements in social interactions, improvements in performance at work or school, and improvements in managing life problems through the patients' experience of respect, trust, and communication with the clinician. These findings indicate that process of care characteristics during the clinical encounter influence patients' perceptions of clinicians' cultural competency and affect functional outcomes. © 2013 National Medical Association. Published by Elsevier Inc. All rights reserved.

Simulation study of light transport in laser-processed LYSO:Ce detectors with single-side readout

NASA Astrophysics Data System (ADS)

Bläckberg, L.; El Fakhri, G.; Sabet, H.

2017-11-01

A tightly focused pulsed laser beam can locally modify the crystal structure inside the bulk of a scintillator. The result is incorporation of so-called optical barriers with a refractive index different from that of the crystal bulk, that can be used to redirect the scintillation light and control the light spread in the detector. We here systematically study the scintillation light transport in detectors fabricated using the laser induced optical barrier technique, and objectively compare their potential performance characteristics with those of the two mainstream detector types: monolithic and mechanically pixelated arrays. Among countless optical barrier patterns, we explore barriers arranged in a pixel-like pattern extending all-the-way or half-way through a 20 mm thick LYSO:Ce crystal. We analyze the performance of the detectors coupled to MPPC arrays, in terms of light response functions, flood maps, line profiles, and light collection efficiency. Our results show that laser-processed detectors with both barrier patterns constitute a new detector category with a behavior between that of the two standard detector types. Results show that when the barrier-crystal interface is smooth, no DOI information can be obtained regardless of barrier refractive index (RI). However, with a rough barrier-crystal interface we can extract multiple levels of DOI. Lower barrier RI results in larger light confinement, leading to better transverse resolution. Furthermore we see that the laser-processed crystals have the potential to increase the light collection efficiency, which could lead to improved energy resolution and potentially better timing resolution due to higher signals. For a laser-processed detector with smooth barrier-crystal interfaces the light collection efficiency is simulated to  >42%, and for rough interfaces  >73%. The corresponding numbers for a monolithic crystal is 39% with polished surfaces, and 71% with rough surfaces, and for a mechanically pixelated array 35% with polished pixel surfaces and 59% with rough surfaces.

Simulation study of light transport in laser-processed LYSO:Ce detectors with single-side readout.

PubMed

Bläckberg, L; El Fakhri, G; Sabet, H

2017-10-19

A tightly focused pulsed laser beam can locally modify the crystal structure inside the bulk of a scintillator. The result is incorporation of so-called optical barriers with a refractive index different from that of the crystal bulk, that can be used to redirect the scintillation light and control the light spread in the detector. We here systematically study the scintillation light transport in detectors fabricated using the laser induced optical barrier technique, and objectively compare their potential performance characteristics with those of the two mainstream detector types: monolithic and mechanically pixelated arrays. Among countless optical barrier patterns, we explore barriers arranged in a pixel-like pattern extending all-the-way or half-way through a 20 mm thick LYSO:Ce crystal. We analyze the performance of the detectors coupled to MPPC arrays, in terms of light response functions, flood maps, line profiles, and light collection efficiency. Our results show that laser-processed detectors with both barrier patterns constitute a new detector category with a behavior between that of the two standard detector types. Results show that when the barrier-crystal interface is smooth, no DOI information can be obtained regardless of barrier refractive index (RI). However, with a rough barrier-crystal interface we can extract multiple levels of DOI. Lower barrier RI results in larger light confinement, leading to better transverse resolution. Furthermore we see that the laser-processed crystals have the potential to increase the light collection efficiency, which could lead to improved energy resolution and potentially better timing resolution due to higher signals. For a laser-processed detector with smooth barrier-crystal interfaces the light collection efficiency is simulated to  >42%, and for rough interfaces  >73%. The corresponding numbers for a monolithic crystal is 39% with polished surfaces, and 71% with rough surfaces, and for a mechanically pixelated array 35% with polished pixel surfaces and 59% with rough surfaces.

Mechanism of action of vitamin C in sepsis: Ascorbate modulates redox signaling in endothelium

PubMed Central

Wilson, John X.

2009-01-01

Circulating levels of vitamin C (ascorbate) are low in patients with sepsis. Parenteral administration of ascorbate raises plasma and tissue concentrations of the vitamin and may decrease morbidity. In animal models of sepsis, intravenous ascorbate injection increases survival and protects several microvascular functions, namely, capillary blood flow, microvascular permeability barrier, and arteriolar responsiveness to vasoconstrictors and vasodilators. The effects of parenteral ascorbate on microvascular function are both rapid and persistent. Ascorbate quickly accumulates in microvascular endothelial cells, scavenges reactive oxygen species, and acts through tetrahydrobiopterin to stimulate nitric oxide production by endothelial nitric oxide synthase. A major reason for the long duration of the improvement in microvascular function is that cells retain high levels of ascorbate, which alter redox-sensitive signaling pathways to diminish septic induction of NADPH oxidase and inducible nitric oxide synthase. These observations are consistent with the hypothesis that microvascular function in sepsis may be improved by parenteral administration of ascorbate as an adjuvant therapy. PMID:19319840

A Review of Patents for the Smart Packaging of Meat and Muscle-based Food Products.

PubMed

Holman, Benjamin; Kerry, Joseph P; Hopkins, David L

2017-10-31

Meat packaging once acted primarily as an inert barrier to protect its contents against contamination and this function has shifted. Packaging now includes complementary functions that improve product quality, longevity and customer/retail appeal. The devices and methods applied to achieve these functions may be categorised as smart packaging, which includes intelligent packaging, devised to monitor and communicate packaged content status, and active packaging, to provide passive adjustment of in-pack conditions from its interactions with the packaged meat. Smart packaging examples already available from recent patents include antimicrobial and antioxidant packaging coatings and inserts; sensors or indicators that identify spoilage and freshness; functional engineering customisations; improvements to packaging integrity; leak or tamper detectors; and, environmentally sustainable options. Together, these inventions respond to industry and customer demands for meat packaging and are therefore the focus of this review, in which we discuss their applications and limitations in meat packaging. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Correlative study of functional and structural regeneration of urothelium after chitosan-induced injury.

PubMed

Erman, Andreja; Kerec Kos, Mojca; Žakelj, Simon; Resnik, Nataša; Romih, Rok; Veranič, Peter

2013-11-01

High transepithelial electrical resistance (TEER) demonstrates a functional permeability barrier of the normal urothelium, which is maintained by a layer of highly differentiated superficial cells. When the barrier is challenged, a quick regeneration is induced. We used side-by-side diffusion chambers as an ex vivo system to determine the time course of functional and structural urothelial regeneration after chitosan-induced injury. The exposure of the urothelium to chitosan caused a 60 % decrease in TEER, the exposure of undifferentiated urothelial cells to the luminal surface and leaky tight junctions. During the regeneration period (350 min), TEER recovered to control values after approximately 200 min, while structural regeneration continued until 350 min after injury. The tight junctions are the earliest and predominant component of the barrier to appear, while complete barrier regeneration is achieved by delayed superficial cell terminal differentiation. The barrier function and the structure of untreated urothelium were unaffected in side-by-side diffusion chambers for at least 6 h. The urinary bladder tissue excised from an animal thus retains the ability to maintain and restore the transepithelial barrier and cellular ultrastructure for a sufficient period to allow for studies of regeneration in ex vivo conditions.

Sculpting bespoke mountains: Determining free energies with basis expansions

NASA Astrophysics Data System (ADS)

Whitmer, Jonathan K.; Fluitt, Aaron M.; Antony, Lucas; Qin, Jian; McGovern, Michael; de Pablo, Juan J.

2015-07-01

The intriguing behavior of a wide variety of physical systems, ranging from amorphous solids or glasses to proteins, is a direct manifestation of underlying free energy landscapes riddled with local minima separated by large barriers. Exploring such landscapes has arguably become one of statistical physics's great challenges. A new method is proposed here for uniform sampling of rugged free energy surfaces. The method, which relies on special Green's functions to approximate the Dirac delta function, improves significantly on existing simulation techniques by providing a boundary-agnostic approach that is capable of mapping complex features in multidimensional free energy surfaces. The usefulness of the proposed approach is established in the context of a simple model glass former and model proteins, demonstrating improved convergence and accuracy over existing methods.

Electronic Health Records and US Public Health: Current Realities and Future Promise

PubMed Central

Parrish, R. Gibson; Ross, David A.

2013-01-01

Electronic health records (EHRs) could contribute to improving population health in the United States. Realizing this potential will require understanding what EHRs can realistically offer to efforts to improve population health, the requirements for obtaining useful information from EHRs, and a plan for addressing these requirements. Potential contributions of EHRs to improving population health include better understanding of the level and distribution of disease, function, and well-being within populations. Requirements are improved population coverage of EHRs, standardized EHR content and reporting methods, and adequate legal authority for using EHRs, particularly for population health. A collaborative national effort to address the most pressing prerequisites for and barriers to the use of EHRs for improving population health is needed to realize the EHR’s potential. PMID:23865646

Acute treatment with kerosene damages the dermal barrier and alters the distribution of topically applied benzo(a)pyrene in mice.

PubMed

LaDow, Kathy; Schumann, Brenda L; Luse, Nicole; Warshawsky, Dave; Pickens, William L; Hoath, Steven B; Talaska, Glenn

2011-12-01

The dermal route is important in many occupational exposures. Some materials may reduce the barrier function of the skin to enhance absorption and effect on internal organs. We have reported previously that kerosene cleaning following treatment with used engine oil increased DNA adduct levels in the lungs of mice compared with animals treated with used oil alone. To investigate what other physiological parameters might be affected by kerosene, we conducted in vitro and in vivo measurements of skin barrier function. We also topically applied (3)H-BAP(100 nM in 25 μL acetone) and washed half the mice with 25 μL kerosene 1 hr after carcinogen application. Groups of four mice were euthanized from 1 to 72 hr after treatment. Skin, lungs, and livers were harvested from each animal and stored separately. Kerosene application reduced the barrier function of the skin in vitro beyond the effect of the acetone vehicle and the vehicle plus BAP. In vivo studies indicated that kerosene treatment reduced the barrier function at 4 and 8 hr post application and that the barrier function recovered at 24 hr after a single treatment. The fraction of the radiolabel remaining in the skin of animals treated with (3)H-BAP and washed with kerosene was significantly less than those not washed, beginning at 24 hr (p< 0.05). Fractional distribution to the lungs and livers of these animals became significantly elevated at this time. Kerosene treatment compromises dermal barrier function and the ability of the skin to retain water, enhances carcinogen absorption, and alters organ distribution. This appears to contribute to the increase in BAP DNA adducts we reported earlier.

Mechanisms of lung endothelial barrier disruption induced by cigarette smoke: role of oxidative stress and ceramides.

PubMed

Schweitzer, Kelly S; Hatoum, Hadi; Brown, Mary Beth; Gupta, Mehak; Justice, Matthew J; Beteck, Besem; Van Demark, Mary; Gu, Yuan; Presson, Robert G; Hubbard, Walter C; Petrache, Irina

2011-12-01

The epithelial and endothelial cells lining the alveolus form a barrier essential for the preservation of the lung respiratory function, which is, however, vulnerable to excessive oxidative, inflammatory, and apoptotic insults. Whereas profound breaches in this barrier function cause pulmonary edema, more subtle changes may contribute to inflammation. The mechanisms by which cigarette smoke (CS) exposure induce lung inflammation are not fully understood, but an early alteration in the epithelial barrier function has been documented. We sought to investigate the occurrence and mechanisms by which soluble components of mainstream CS disrupt the lung endothelial cell barrier function. Using cultured primary rat microvascular cell monolayers, we report that CS induces endothelial cell barrier disruption in a dose- and time-dependent manner of similar magnitude to that of the epithelial cell barrier. CS exposure triggered a mechanism of neutral sphingomyelinase-mediated ceramide upregulation and p38 MAPK and JNK activation that were oxidative stress dependent and that, along with Rho kinase activation, mediated the endothelial barrier dysfunction. The morphological changes in endothelial cell monolayers induced by CS included actin cytoskeletal rearrangement, junctional protein zonula occludens-1 loss, and intercellular gap formation, which were abolished by the glutathione modulator N-acetylcysteine and ameliorated by neutral sphingomyelinase inhibition. The direct application of ceramide recapitulated the effects of CS, by disrupting both endothelial and epithelial cells barrier, by a mechanism that was redox and apoptosis independent and required Rho kinase activation. Furthermore, ceramide induced dose-dependent alterations of alveolar microcirculatory barrier in vivo, measured by two-photon excitation microscopy in the intact rat. In conclusion, soluble components of CS have direct endothelial barrier-disruptive effects that could be ameliorated by glutathione modulators or by inhibitors of neutral sphingomyelinase, p38 MAPK, JNK, and Rho kinase. Amelioration of endothelial permeability may alleviate lung and systemic vascular dysfunction associated with smoking-related chronic obstructive lung diseases.

Structure and Barrier Properties of Multinanolayered Biodegradable PLA/PBSA Films: Confinement Effect via Forced Assembly Coextrusion.

PubMed

Messin, Tiphaine; Follain, Nadège; Guinault, Alain; Sollogoub, Cyrille; Gaucher, Valérie; Delpouve, Nicolas; Marais, Stéphane

2017-08-30

Multilayer coextrusion processing was applied to produce 2049-layer film of poly(butylene succinate-co-butylene adipate) (PBSA) confined against poly(lactic acid) (PLA) using forced assembly, where the PBSA layer thickness was about 60 nm. This unique technology allowed to process semicrystalline PBSA as confined polymer and amorphous PLA as confining polymer in a continuous manner. The continuity of PBSA layers within the 80/20 wt % PLA/PBSA layered films was clearly evidenced by atomic force microscopy (AFM). Similar thermal events to the reference films were revealed by thermal studies; indicating no diffusion of polymers during the melt-processing. Mechanical properties were measured for the multilayer film and the obtained results were those expected considering the fraction of each polymer, revealing the absence of delamination in the PLA/PBSA multinanolayer film. The confinement effect induced by PLA led to a slight orientation of the crystals, an increase of the rigid amorphous fraction (RAF) in PBSA with a densification of this fraction without changing film crystallinity. These structural changes allowed to strongly improve the water vapor and gas barrier properties of the PBSA layer into the multilayer film up to two decades in the case of CO 2 gas. By confining the PBSA structure in very thin and continuous layers, it was then possible to improve the barrier performances of a biodegradable system and the resulting barrier properties were successfully correlated to the effect of confinement on the microstructure and the chain segment mobility of the amorphous phase. Such investigation on these multinanolayers of PLA/PBSA with the aim of evidencing relationships between microstructure implying RAF and barrier performances has never been performed yet. Besides, gas and water permeation results have shown that the barrier improvement obtained from the multilayer was mainly due to the reduction of solubility linked to the reduction of the free volume while the tortuosity effect, as usually expected, was not really observed. This work brings new insights in the field of physicochemical behaviors of new multilayer films made of biodegradable polyesters but also in interfacial processes due to the confinement effect induced in these multinanolayer structures obtained by the forced assembly coextrusion. This original coextrusion process was a very advantageous technique to produce eco-friendly materials with functional properties without the help of tie layer, additives, solvents, surface treatments, or inorganic fillers.

Willingness to participate in a parental training intervention to reduce neurocognitive late effects among Latino parents of childhood cancer survivors.

PubMed

Dennis, Jessica M; Rosen, Roxanna; Patel, Sunita K

2015-03-01

The purpose of the study was to examine correlates of Spanish-speaking Latino parents' interest for participation in an educational intervention to improve learning and school success in children with cancer-related cognitive and behavioral late effects. Participants included 73 Latino caregivers of school-age children who are survivors of brain tumor or leukemia and at risk for cognitive late effects. The parents completed a battery of surveys relating to interest in and barriers to intervention participation, as well as measures of parental knowledge and beliefs and their children's cognitive functioning, and health-related quality of life. Results showed that the majority of parents expressed interest in participating in the proposed 8-week intervention, with over 90% indicating interest in learning more about improving grades, making learning more exciting, being a role model, and the impact of cancer on memory. The factors most strongly related to interest in intervention included lower maternal education as well as perceptions of greater child cognitive difficulties and lower health-related quality of life. The barriers most highly endorsed by the most parents were difficulty paying for gas, child care responsibility, and too much stress in other parts of life. Also highly endorsed as barriers were statements relating to the child's lack of interest and need for services (i.e., my child is doing fine). These findings are consistent with the Health Belief Model wherein decisions to engage in health-related behaviors are made by weighing the potential benefits relative to the costs and barriers.

Willingness to Participate in a Parental Training Intervention to Reduce Neurocognitive Late Effects among Latino Parents of Childhood Cancer Survivors

PubMed Central

Dennis, Jessica M.; Rosen, Roxanna; Patel, Sunita K.

2014-01-01

The purpose of the study was to examine correlates of Spanish-speaking Latino parents’ interest for participation in an educational intervention to improve learning and school success in children with cancer-related cognitive and behavioral late effects. Participants included 73 Latino caregivers of school age children who are survivors of brain tumor or leukemia and at risk for cognitive late effects. . The parents completed a battery of surveys relating to interest in and barriers to intervention participation, as well as measures of parental knowledge and beliefs and their children's cognitive functioning, and health-related quality of life. Results showed that the majority of parents expressed interest in participating in the proposed 8-week intervention, with over 90% indicating interest in learning more about improving grades, making learning more exciting, being a role model, and the impact of cancer on memory. The factors most strongly related to interest in intervention included lower maternal education, as well as perceptions of greater child cognitive difficulties and lower health-related quality of life. The barriers most highly endorsed by the most parents were difficulty paying for gas, child care responsibility, and too much stress in other parts of life. Also highly endorsed as barriers were statements relating to the child's lack of interest and need for services (i.e., my child is doing fine). These findings are consistent with the Health Belief Model wherein decisions to engage in health-related behaviors are made by weighing the potential benefits relative to the costs and barriers. PMID:24792525

[The stratum corneum].

PubMed

Haftek, M

2002-01-01

Epidermal differentiation is a continuous process, constituting and renewing a protective layer at the skin surface: the stratum corneum, composed of cornified keratinocytes that is a barrier to water diffusion. Massive loss of physiologic liquids is one of the severest consequences of extensive burns. The stratum corneum also protects the subjacent tissues from xenobiotic aggression, ultraviolet radiation (70 p. cent of UVB absorption) and from mechanic aggression. The integrity of the stratum corneum depends on three elements: 1) the physico-chemical quality of the cornified cells, 2) the persistence of mechanical junctions uniting these cells and 3) the organization and composition of the lipid "mortar" in the intercellular spaces. Since all these components are issued from the keratinocyte differentiation process, any perturbation may, in time, induce modifications in the "barrier" function of the epidermis. The barrier quality varies, depending on its localization (soles of the feet, palms of the hands and transitional epidermis of the lips), during skin healing (priority to keratinocyte proliferation to the detriment of maturation) under the influence of treatment (retinoids, vitamin D derivatives), in the course of aging and diseases: ichtyosis and other keratinization genodermatoses, benign (including psoriasis) and malignant hyperproliferative diseases. Furthermore, the relative impermeability of the stratum corneum is an important factor limiting the penetration and diffusion of allergens, but also local drugs delivered with local and systemic trans-epidermal treatments. Further knowledge is required on the function of the epidermal barrier and the mechanism regulating cohesion/desquamation of the stratum corneum to understand certain hereditary diseases, improve efficacy of topical therapeutic products and optimize cosmetic formulations.

Employment status, employment functioning, and barriers to employment among VA primary care patients.

PubMed

Zivin, Kara; Yosef, Matheos; Levine, Debra S; Abraham, Kristen M; Miller, Erin M; Henry, Jennifer; Nelson, C Beau; Pfeiffer, Paul N; Sripada, Rebecca K; Harrod, Molly; Valenstein, Marcia

2016-03-15

Prior research found lower employment rates among working-aged patients who use the VA than among non-Veterans or Veterans who do not use the VA, with the lowest reported employment rates among VA patients with mental disorders. This study assessed employment status, employment functioning, and barriers to employment among VA patients treated in primary care settings, and examined how depression and anxiety were associated with these outcomes. The sample included 287 VA patients treated in primary care in a large Midwestern VA Medical Center. Bivariate and multivariable analyses were conducted examining associations between socio-demographic and clinical predictors of six employment domains, including: employment status, job search self-efficacy, work performance, concerns about job loss among employed Veterans, and employment barriers and likelihood of job seeking among not employed Veterans. 54% of respondents were employed, 36% were not employed, and 10% were economically inactive. In adjusted analyses, participants with depression or anxiety (43%) were less likely to be employed, had lower job search self-efficacy, had lower levels of work performance, and reported more employment barriers. Depression and anxiety were not associated with perceived likelihood of job loss among employed or likelihood of job seeking among not employed. Single VA primary care clinic; cross-sectional study. Employment rates are low among working-aged VA primary care patients, particularly those with mental health conditions. Offering primary care interventions to patients that address mental health issues, job search self-efficacy, and work performance may be important in improving health, work, and economic outcomes. Published by Elsevier B.V.

Checkpoints to Progression: Qualitative Analysis of the Personal and Contextual Factors That Influence Selection of Upper Extremity Reconstruction Among Patients With Tetraplegia.

PubMed

Harris, Chelsea A; Muller, John-Michael; Shauver, Melissa J; Chung, Kevin C

2017-07-01

Patients with tetraplegia consistently rank better use of the upper extremity as their top functional priority. Multiple case series have demonstrated that upper extremity reconstruction (UER) is well-tolerated and can produce substantial functional improvements for appropriate candidates; however, UER remains critically underutilized. The mechanisms that drive differences in provider practice and referral patterns have been studied, but comprehensive examination of the patient factors that influence UER decisions has not been performed for American patients. Nineteen patients with C4-8 cervical spinal injuries were selected using purposive sampling: 9 patients had undergone UER, 10 had not undergone UER. Semistructured interviews were conducted and transcripts evaluated using grounded theory methodology. Our study yielded a conceptual model that describes the characteristics common to all patients who undergo UER. Patients who selected reconstruction proceeded stepwise through a shared sequence of steps: (1) functional dissatisfaction, (2) awareness of UER, and (3) acceptance of surgery. Patients' ability to meet these criteria was determined by 3 checkpoints: how well they coped, their access to information, and the acceptability of surgery. Extremely positive or negative coping prevented patients from moving from the Coping to the Information Checkpoint; thus, they remained unaware of UER and did not undergo surgery. A lack of knowledge regarding reconstruction was the strongest barrier to surgery among our participants. We built a conceptual model that outlines how patients' personal and contextual factors drive their progression to UER. Moving from functional dissatisfaction to understanding that they were candidates for UER was a substantial barrier for participants, particularly those with very high and very low coping skills. To improve utilization for all patients, interventions are needed to increase UER awareness. Standardizing introduction to UER during the rehabilitation process or improving e-content may represent key awareness access points. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Simple improvements to classical bubble nucleation models.

PubMed

Tanaka, Kyoko K; Tanaka, Hidekazu; Angélil, Raymond; Diemand, Jürg

2015-08-01

We revisit classical nucleation theory (CNT) for the homogeneous bubble nucleation rate and improve the classical formula using a correct prefactor in the nucleation rate. Most of the previous theoretical studies have used the constant prefactor determined by the bubble growth due to the evaporation process from the bubble surface. However, the growth of bubbles is also regulated by the thermal conduction, the viscosity, and the inertia of liquid motion. These effects can decrease the prefactor significantly, especially when the liquid pressure is much smaller than the equilibrium one. The deviation in the nucleation rate between the improved formula and the CNT can be as large as several orders of magnitude. Our improved, accurate prefactor and recent advances in molecular dynamics simulations and laboratory experiments for argon bubble nucleation enable us to precisely constrain the free energy barrier for bubble nucleation. Assuming the correction to the CNT free energy is of the functional form suggested by Tolman, the precise evaluations of the free energy barriers suggest the Tolman length is ≃0.3σ independently of the temperature for argon bubble nucleation, where σ is the unit length of the Lennard-Jones potential. With this Tolman correction and our prefactor one gets accurate bubble nucleation rate predictions in the parameter range probed by current experiments and molecular dynamics simulations.

Charge plasma based source/drain engineered Schottky Barrier MOSFET: Ambipolar suppression and improvement of the RF performance

NASA Astrophysics Data System (ADS)

Kale, Sumit; Kondekar, Pravin N.

2018-01-01

This paper reports a novel device structure for charge plasma based Schottky Barrier (SB) MOSFET on ultrathin SOI to suppress the ambipolar leakage current and improvement of the radio frequency (RF) performance. In the proposed device, we employ dual material for the source and drain formation. Therefore, source/drain is divided into two parts as main source/drain and source/drain extension. Erbium silicide (ErSi1.7) is used as main source/drain material and Hafnium metal is used as source/drain extension material. The source extension induces the electron plasma in the ultrathin SOI body resulting reduction of SB width at the source side. Similarly, drain extension also induces the electron plasma at the drain side. This significantly increases the SB width due to increased depletion at the drain end. As a result, the ambipolar leakage current can be suppressed. In addition, drain extension also reduces the parasitic capacitances of the proposed device to improve the RF performance. The optimization of length and work function of metal used in the drain extension is performed to achieve improvement in device performance. Moreover, the proposed device makes fabrication simpler, requires low thermal budget and free from random dopant fluctuations.

The Americans with Disabilities Act: Implications for Camp Programming.

ERIC Educational Resources Information Center

Bedini, Leandra A.; And Others

1992-01-01

Discusses the effect of the Americans with Disabilities Act (ADA) on camp programing and provides strategies to improve camp accessibility for people with disabilities. Discusses obstacles to integrated programing including ecological and architectural barriers, attitudinal barriers, transportation barriers, barriers of omission, economic…

Interferon-gamma increased epithelial barrier function via upregulating claudin-7 expression in human submandibular gland duct epithelium.

PubMed

Abe, Ayumi; Takano, Kenichi; Kojima, Takashi; Nomura, Kazuaki; Kakuki, Takuya; Kaneko, Yakuto; Yamamoto, Motohisa; Takahashi, Hiroki; Himi, Tetsuo

2016-06-01

Tight junctions (TJs) are necessary for salivary gland function and may serve as indicators of salivary gland epithelial dysfunction. IgG4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition which disrupts the TJ associated epithelial barrier. The salivary glands are one of the most frequently involved organs in IgG4-RD, however, changes of the TJ associated epithelial barrier in salivary gland duct epithelium is poorly understood. Here, we investigated the regulation and function of TJs in human submandibular gland ductal epithelial cells (HSDECs) in normal and IgG4-RD. We examined submandibular gland (SMG) tissue from eight control individuals and 22 patients with IgG4-RD and established an HSDEC culture system. Immunohistochemistry, immunocytochemistry, western blotting, and measurement of transepithelial electrical resistance (TER) were performed. Claudin-4, claudin-7, occludin, and JAM-A were expressed at the apical side of the duct epithelium in submandibular gland (SMG) tissue and at the cell borders in HSDECs of normal and IgG4-RD. The expression and distribution of TJs in SMG tissue were not different in control individuals and patients with IgG4-RD in vivo and in vitro. Although interferon-gamma (IFNγ) generally disrupts the integrity and function of TJs, as manifested by decreased epithelial barrier function, IFNγ markedly increased the epithelial barrier function of HSDECs via upregulation of claudin-7 expression in HSDECs from patients with IgG4-RD. This is the first report showing an IFNγ-dependent increase in epithelial barrier function in the salivary gland duct epithelium. Our results provide insights into the functional significance of TJs in salivary gland duct epithelium in physiological and pathological conditions, including IgG4-RD.

Simultaneous assessment of glomerular filtration and barrier function in live zebrafish

PubMed Central

Kotb, Ahmed M.; Müller, Tobias; Xie, Jing; Anand-Apte, Bela; Endlich, Nicole

2014-01-01

The zebrafish pronephros is a well-established model to study glomerular development, structure, and function. A few methods have been described to evaluate glomerular barrier function in zebrafish larvae so far. However, there is a need to assess glomerular filtration as well. In the present study, we extended the available methods by simultaneously measuring the intravascular clearances of Alexa fluor 647-conjugated 10-kDa dextran and FITC-conjugated 500-kDa dextran as indicators of glomerular filtration and barrier function, respectively. After intravascular injection of the dextrans, mean fluorescence intensities of both dextrans were measured in the cardinal vein of living zebrafish (4 days postfertilization) by confocal microscopy over time. We demonstrated that injected 10-kDa dextran was rapidly cleared from the circulation, became visible in the lumen of the pronephric tubule, quickly accumulated in tubular cells, and was detectably excreted at the cloaca. In contrast, 500-kDa dextran could not be visualized in the tubule at any time point. To check whether alterations in glomerular function can be quantified by our method, we injected morpholino oligonucleotides (MOs) against zebrafish nonmuscle myosin heavy chain IIA (zMyh9) or apolipoprotein L1 (zApol1). While glomerular filtration was reduced in zebrafish nonmuscle myosin heavy chain IIA MO-injected larvae, glomerular barrier function remained intact. In contrast, in zebrafish apolipoprotein L1 MO-injected larvae, glomerular barrier function was compromised as 500-kDa dextran disappeared from the circulation and became visible in tubular cells. In summary, we present a novel method that allows to simultaneously assess glomerular filtration and barrier function in live zebrafish. PMID:25298528

Knowledge, perceptions and preferences of elderly regarding protein-enriched functional food.

PubMed

van der Zanden, Lotte D T; van Kleef, Ellen; de Wijk, René A; van Trijp, Hans C M

2014-09-01

Promoting protein consumption in the elderly population may contribute to improving the quality of their later years in life. Our study aimed to explore knowledge, perceptions and preferences of elderly consumers regarding protein-enriched food. We conducted three focus groups with independently living (ID) elderly (N = 24, Mage = 67 years) and three with elderly living in a residential home (RH) (N = 18, Mage = 83 years). Both the ID and RH elderly were predominantly sceptical about functional food in general. Confusion, distrust and a perceived lack of personal relevance were main perceived barriers to purchasing and consuming these products, although a majority of the participants did report occasionally consuming at least one type of functional food. For the ID elderly, medical advice was an important facilitator that could overcome barriers to purchasing and consuming protein-enriched food, indicating the importance of personal relevance for this group. For the RH elderly, in contrast, sensory appeal of protein-enriched foods was a facilitator. Carrier preferences were similar for the two groups; the elderly preferred protein-enriched foods based on healthy products that they consumed frequently. Future studies should explore ways to deal with the confusion and distrust regarding functional food within the heterogeneous population of elderly. Copyright © 2014 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Liwen, E-mail: lwcheng@yzu.edu.cn; Wu, Shudong; Xia, Changquan

In this work, graded barrier InGaN light-emitting diodes with increasing indium composition barriers are proposed and investigated numerically. When the conventional GaN barriers are replaced by this unique graded InGaN barrier design, the forward voltage at 100 mA is reduced from 3.32 V to 3.27 V, and the efficiency droop is improved from 46.6% to 7.5%. The simulation results observed in this work indicate that these improvements can be attributed to increased electron confinement and enhanced hole injection efficiency caused by the modified energy band diagram.

Importance of the correlation contribution for local hybrid functionals: range separation and self-interaction corrections.

PubMed

Arbuznikov, Alexei V; Kaupp, Martin

2012-01-07

Local hybrid functionals with their position-dependent exact-exchange admixture are a conceptually simple and promising extension of the concept of a hybrid functional. Local hybrids based on a simple mixing of the local spin density approximation (LSDA) with exact exchange have been shown to be successful for thermochemistry, reaction barriers, and a range of other properties. So far, the combination of this generation of local hybrids with an LSDA correlation functional has been found to give the most favorable results for atomization energies, for a range of local mixing functions (LMFs) governing the exact-exchange admixture. Here, we show that the choice of correlation functional to be used with local hybrid exchange crucially influences the parameterization also of the exchange part as well as the overall performance. A novel ansatz for the correlation part of local hybrids is suggested based on (i) range-separation of LSDA correlation into short-range (SR) and long-range (LR) parts, and (ii) partial or full elimination of the one-electron self-correlation from the SR part. It is shown that such modified correlation functionals allow overall larger exact exchange admixture in thermochemically competitive local hybrids than before. This results in improvements for reaction barriers and for other properties crucially influenced by self-interaction errors, as demonstrated by a number of examples. Based on the range-separation approach, a fresh view on the breakdown of the correlation energy into dynamical and non-dynamical parts is suggested.

Where to restore ecological connectivity? Detecting barriers and quantifying restoration benefits.

PubMed

McRae, Brad H; Hall, Sonia A; Beier, Paul; Theobald, David M

2012-01-01

Landscape connectivity is crucial for many ecological processes, including dispersal, gene flow, demographic rescue, and movement in response to climate change. As a result, governmental and non-governmental organizations are focusing efforts to map and conserve areas that facilitate movement to maintain population connectivity and promote climate adaptation. In contrast, little focus has been placed on identifying barriers-landscape features which impede movement between ecologically important areas-where restoration could most improve connectivity. Yet knowing where barriers most strongly reduce connectivity can complement traditional analyses aimed at mapping best movement routes. We introduce a novel method to detect important barriers and provide example applications. Our method uses GIS neighborhood analyses in conjunction with effective distance analyses to detect barriers that, if removed, would significantly improve connectivity. Applicable in least-cost, circuit-theoretic, and simulation modeling frameworks, the method detects both complete (impermeable) barriers and those that impede but do not completely block movement. Barrier mapping complements corridor mapping by broadening the range of connectivity conservation alternatives available to practitioners. The method can help practitioners move beyond maintaining currently important areas to restoring and enhancing connectivity through active barrier removal. It can inform decisions on trade-offs between restoration and protection; for example, purchasing an intact corridor may be substantially more costly than restoring a barrier that blocks an alternative corridor. And it extends the concept of centrality to barriers, highlighting areas that most diminish connectivity across broad networks. Identifying which modeled barriers have the greatest impact can also help prioritize error checking of land cover data and collection of field data to improve connectivity maps. Barrier detection provides a different way to view the landscape, broadening thinking about connectivity and fragmentation while increasing conservation options.

Influence of niacinamide containing formulations on the molecular and biophysical properties of the stratum corneum.

PubMed

Mohammed, D; Crowther, J M; Matts, P J; Hadgraft, J; Lane, M E

2013-01-30

Niacinamide-containing moisturisers are known be efficacious in alleviating dry skin conditions and improving stratum corneum (SC) barrier function. However, the mechanisms of action of niacinamide at the molecular level in the SC are still not well understood. Previously, we have reported the development of novel methods to probe SC barrier properties in vivo. The aim of the present study was to characterise changes in Trans Epidermal Water Loss (TEWL), corneocyte surface area and maturity, selected protease activities and SC thickness after repeated application of a simple vehicle containing niacinamide. A commercial formulation was also included as a reference. The left and right mid-volar forearms of 20 healthy volunteers were used as study sites, to which topical formulations were applied twice daily for 28 days. After successive tape-stripping, corneocyte maturity and surface area were assessed. In addition, activity of the desquamatory kallikrein (KLK) protease enzymes KLK5 and KLK7, and tryptase and plasmin (implicated in inflammatory process) were measured using a fluorogenic probe assay. The amount of protein removed and TEWL were also recorded. SC thickness before and after treatment was determined using Confocal Raman Spectroscopy (CRS). Overall (i) corneocyte maturity and surface area decreased with increasing number of tape strips, (ii) activity of both the desquamatory and inflammatory enzymes was highest in the outer layers of the SC and decreased with depth (iii) TEWL increased as more SC layers were removed. Furthermore, areas treated with formulations containing niacinamide were significantly different to pre-treatment baseline and untreated/vehicle-control treated sites, with larger and more mature corneocytes, decreased inflammatory activity, decreased TEWL and increased SC thickness. These data (a) confirm the utility of measures and metrics developed previously for the non-invasive assay of SC barrier function, (b) present an holistic picture of a SC compartment managing barrier function through dynamic optimisation of pathlength and quality of building materials used, and (c) shed new light on niacinamide as a topical formulation adjunct with unique SC barrier-augmentation properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Assessing theoretical uncertainties in fission barriers of superheavy nuclei

DOE PAGES

Agbemava, S. E.; Afanasjev, A. V.; Ray, D.; ...

2017-05-26

Here, theoretical uncertainties in the predictions of inner fission barrier heights in superheavy elements have been investigated in a systematic way for a set of state-of-the-art covariant energy density functionals which represent major classes of the functionals used in covariant density functional theory. They differ in basic model assumptions and fitting protocols. Both systematic and statistical uncertainties have been quantified where the former turn out to be larger. Systematic uncertainties are substantial in superheavy elements and their behavior as a function of proton and neutron numbers contains a large random component. The benchmarking of the functionals to the experimental datamore » on fission barriers in the actinides allows to reduce the systematic theoretical uncertainties for the inner fission barriers of unknown superheavy elements. However, even then they on average increase on moving away from the region where benchmarking has been performed. In addition, a comparison with the results of non-relativistic approaches is performed in order to define full systematic theoretical uncertainties over the state-of-the-art models. Even for the models benchmarked in the actinides, the difference in the inner fission barrier height of some superheavy elements reaches $5-6$ MeV. This uncertainty in the fission barrier heights will translate into huge (many tens of the orders of magnitude) uncertainties in the spontaneous fission half-lives.« less

Community pharmacy patient perceptions of a pharmacy-initiated mobile technology app to improve adherence.

PubMed

DiDonato, Kristen L; Liu, Yifei; Lindsey, Cameron C; Hartwig, David Matthew; Stoner, Steven C

2015-10-01

To determine patient perceptions of using a demonstration application (app) of mobile technology to improve medication adherence and to identify desired features to assist in the management of medications. A qualitative study using key informant interviews was conducted in a community pharmacy chain for patients aged 50 and older, on statin therapy and owning a smart device. Three main themes emerged from 24 interviews at four pharmacy locations, which included benefits, barriers and desired features of the app. Benefits such as accessibility, privacy, pros of appearance and beneficiaries were more likely to lead to usage of the app. Barriers that might prevent usage of the app were related to concerns of appearance, the burden it might cause for others, cost, privacy, motivation and reliability. Specific features patients desired were categorized under appearance, customization, communication, functionality, input and the app platform. Patients provided opinions about using a mobile app to improve medication adherence and assist with managing medications. Patients envisioned the app within their lifestyle and expressed important considerations, identifying benefits to using this technology and voicing relevant concerns. App developers can use patient perceptions to guide development of a mobile app addressing patient medication-related needs. © 2015 Royal Pharmaceutical Society.

Functionalized Carbon Nanotubes with Phosphorus- and Nitrogen-Containing Agents: Effective Reinforcer for Thermal, Mechanical, and Flame-Retardant Properties of Polystyrene Nanocomposites.

PubMed

Xing, Weiyi; Yang, Wei; Yang, Wenjie; Hu, Qihang; Si, Jingyu; Lu, Hongdian; Yang, Benhong; Song, Lei; Hu, Yuan; Yuen, Richard K K

2016-10-05

Aminated multiwalled carbon nanotubes (A-MWCNT) were reacted with diphenylphosphinic chloride (DPP-Cl) to prepare the functionalized MWCNT (DPPA-MWCNT). A-MWCNT and DPPA-MWCNT were respectively mixed with polystyrene (PS) to obtain composites through the melt compounding method. SEM observations demonstrated that the DPPA-MWCNT nanofillers were more uniformly distributed within the PS matrix than A-MWCNT. PS/DPPA-MWCNT showed improved thermal stability, glass transition temperature, and tensile strength in comparison with PS/A-MWCNT, resulting from good dispersion and interfacial interactions between DPPA-MWCNT and PS matrix. The incorporation of DPPA-MWCNT to PS significantly reduced peak heat release rate, smoke production rate, and carbon monoxide and carbon dioxide release in cone calorimeter tests. The enhanced fire-retardant properties should be ascribed to the barrier effect of carbon nanotubes, which could provide enough time for DPPA-MWCNT and its functionalized groups to trap the degrading polymer radicals to catalyze char formation. The char layer served as an efficient insulating barrier to reduce the exposure of polymer matrix to an external heat source as well as retarding the flammable gases from feeding the flame.

The Roles of Vitamin C in Skin Health

PubMed Central

Pullar, Juliet M.; Carr, Anitra C.; Vissers, Margreet C. M.

2017-01-01

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake. PMID:28805671

It Comes With the Job: Work Organizational, Job Design, and Self-Regulatory Barriers to Improving the Health Status of Train Drivers.

PubMed

Naweed, Anjum; Chapman, Janine; Allan, Matthew; Trigg, Joshua

2017-03-01

This study aimed to examine the impacts of key barriers to improving the occupational health status of Australian train drivers. From May to June, 2015, five semi-structured qualitative focus groups were conducted with 29 train drivers from South Australian, Victorian, and New South Wales-based rail organizations in Australia. Occupational health was impeded by multiple barriers regarding sleep (patterns/fatigue), diet (planning/context), mental health (occupational stress), rostering (low autonomy), sedentary time, low fitness motivation, and family/social life conflicts. Work organizational barriers included communication issues, low organizational support, and existing social norms. Job design barriers included rostering, fatigue, stimulant reliance, and family/social life imbalances. Self-regulatory barriers included dietary and exercise patterns habits and patterns. Occupational health interventions for Australian train drivers must address work organizational, job design, and self-regulatory barriers to healthier lifestyle behaviors.

Delayed astrocytic contact with cerebral blood vessels in FGF-2 deficient mice does not compromise permeability properties at the developing blood-brain barrier.

PubMed

Saunders, Norman R; Dziegielewska, Katarzyna M; Unsicker, Klaus; Ek, C Joakim

2016-11-01

The brain functions within a specialized environment tightly controlled by brain barrier mechanisms. Understanding the regulation of barrier formation is important for understanding brain development and may also lead to finding new ways to deliver pharmacotherapies to the brain; access of many potentially promising drugs is severely hindered by these barrier mechanisms. The cellular composition of the neurovascular unit of the blood-brain barrier proper and their effects on regulation of its function are beginning to be understood. One hallmark of the neurovascular unit in the adult is the astroglial foot processes that tightly surround cerebral blood vessels. However their role in barrier formation is still unclear. In this study we examined barrier function in newborn, juvenile and adult mice lacking fibroblast growth factor-2 (FGF-2), which has been shown to result in altered astroglial differentiation during development. We show that during development of FGF-2 deficient mice the astroglial contacts with cerebral blood vessels are delayed compared with wild-type animals. However, this delay did not result in changes to the permeability properties of the blood brain barrier as assessed by exclusion of either small or larger sized molecules at this interface. In addition cerebral vessels were positive for tight-junction proteins and we observed no difference in the ultrastructure of the tight-junctions. The results indicate that the direct contact of astroglia processes to cerebral blood vessels is not necessary for either the formation of the tight-junctions or for basic permeability properties and function of the blood-brain barrier. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1201-1212, 2016. © 2016 Wiley Periodicals, Inc.

Hydrogen inhalation ameliorated mast cell-mediated brain injury after intracerebral hemorrhage in mice.

PubMed

Manaenko, Anatol; Lekic, Tim; Ma, Qingyi; Zhang, John H; Tang, Jiping

2013-05-01

Hydrogen inhalation was neuroprotective in several brain injury models. Its mechanisms are believed to be related to antioxidative stress. We investigated the potential neurovascular protective effect of hydrogen inhalation especially effect on mast cell activation in a mouse model of intracerebral hemorrhage. Controlled in vivo laboratory study. Animal research laboratory. One hundred seventy-one 8-week-old male CD-1 mice were used. Collagenase-induced intracerebral hemorrhage model in 8-week-old male CD-1 mice was used. Hydrogen was administrated via spontaneous inhalation. The blood-brain barrier permeability and neurologic deficits were investigated at 24 and 72 hours after intracerebral hemorrhage. Mast cell activation was evaluated by Western blot and immuno-staining. The effects of hydrogen inhalation on mast cell activation were confirmed in an autologous blood injection model intracerebral hemorrhage. At 24 and 72 hours post intracerebral hemorrhage, animals showed blood-brain barrier disruption, brain edema, and neurologic deficits, accompanied with phosphorylation of Lyn kinase and release of tryptase, indicating mast cell activation. Hydrogen treatment diminished phosphorylation of Lyn kinase and release of tryptase, decreased accumulation and degranulation of mast cells, attenuated blood-brain barrier disruption, and improved neurobehavioral function. Activation of mast cells following intracerebral hemorrhage contributed to increase of blood-brain barrier permeability and brain edema. Hydrogen inhalation preserved blood-brain barrier disruption by prevention of mast cell activation after intracerebral hemorrhage.

High Fat Diets Induce Colonic Epithelial Cell Stress and Inflammation that is Reversed by IL-22

PubMed Central

Gulhane, Max; Murray, Lydia; Lourie, Rohan; Tong, Hui; Sheng, Yong H.; Wang, Ran; Kang, Alicia; Schreiber, Veronika; Wong, Kuan Yau; Magor, Graham; Denman, Stuart; Begun, Jakob; Florin, Timothy H.; Perkins, Andrew; Cuív, Páraic Ó.; McGuckin, Michael A.; Hasnain, Sumaira Z.

2016-01-01

Prolonged high fat diets (HFD) induce low-grade chronic intestinal inflammation in mice, and diets high in saturated fat are a risk factor for the development of human inflammatory bowel diseases. We hypothesized that HFD-induced endoplasmic reticulum (ER)/oxidative stress occur in intestinal secretory goblet cells, triggering inflammatory signaling and reducing synthesis/secretion of proteins that form the protective mucus barrier. In cultured intestinal cells non-esterified long-chain saturated fatty acids directly increased oxidative/ER stress leading to protein misfolding. A prolonged HFD elevated the intestinal inflammatory cytokine signature, alongside compromised mucosal barrier integrity with a decrease in goblet cell differentiation and Muc2, a loss in the tight junction protein, claudin-1 and increased serum endotoxin levels. In Winnie mice, that develop spontaneous colitis, HFD-feeding increased ER stress, further compromised the mucosal barrier and increased the severity of colitis. In obese mice IL-22 reduced ER/oxidative stress and improved the integrity of the mucosal barrier, and reversed microbial changes associated with obesity with an increase in Akkermansia muciniphila. Consistent with epidemiological studies, our experiments suggest that HFDs are likely to impair intestinal barrier function, particularly in early life, which partially involves direct effects of free-fatty acids on intestinal cells, and this can be reversed by IL-22 therapy. PMID:27350069

[Advances in the research of effects of glutamine on immune function of burn patients].

PubMed

Liu, Y H; Guo, P F; Chen, G Y; Bo, Y C; Ma, Y; Cui, Z J

2018-04-20

Glutamine is the most abundant amino acid found in plasma and cells. It is the preferred fuel for enterocytes in the small intestine, macrophages, and lymphocytes. After serious burn, increased requirement of glutamine by the gastrointestinal tract, kidney and lymphocytes, and relatively insufficient self synthesis likely contribute to the rapid decline of glutamine in circulation and cells. Glutamine supplementation can not only protect intestinal mucosa, maintain normal intestinal barrier function, reduce bacterial translocation, and enhance the intestinal immune function, but also increase the number of lymphocytes, enhance the phagocytic function of macrophage, promote the synthesis of immunoglobulin, and reduce the body's inflammatory response, so as to enhance the immune function. Therefore, glutamine supplementation can improve and enhance the immune function, reduce complications and promote the prognosis of severely burned patients.

Krüppel-like factor 5 is essential for maintenance of barrier function in mouse colon.

PubMed

Liu, Yang; Chidgey, Martyn; Yang, Vincent W; Bialkowska, Agnieszka B

2017-11-01

Krüppel-like factor 5 (KLF5) is a member of the zinc finger family of transcription factors that regulates homeostasis of the intestinal epithelium. Previous studies suggested an indispensable role of KLF5 in maintaining intestinal barrier function. In the current study, we investigated the mechanisms by which KLF5 regulates colonic barrier function in vivo and in vitro. We used an inducible and a constitutive intestine-specific Klf5 knockout mouse models ( Villin-CreER T2 ;Klf5 fl/fl designated as Klf5 ΔIND and Villin-Cre;Klf5 fl/fl as Klf5 ΔIS ) and studied an inducible KLF5 knockdown in Caco-2 BBe cells using a lentiviral Tet-on system (Caco-2 BBe KLF5ΔIND ). Specific knockout of Klf5 in colonic tissues, either inducible or constitutive, resulted in increased intestinal permeability. The phenotype was accompanied by a significant reduction in Dsg2 , which encodes desmoglein-2, a desmosomal cadherin, at both mRNA and protein levels. Transmission electron microscopy showed alterations of desmosomal morphology in both KLF5 knockdown Caco-2 BBe cells and Klf5 knockout mouse colonic tissues. Inducible knockdown of KLF5 in Caco-2BBe cells grown on Transwell plates led to impaired barrier function as evidenced by decreased transepithelial electrical resistance and increased paracellular permeability to fluorescein isothiocyanate-4 kDa dextran. Furthermore, DSG2 was significantly decreased in KLF5 knockdown cells, and DSG2 overexpression partially rescued the impaired barrier function caused by KLF5 knockdown. Electron microscopy studies demonstrated altered desmosomal morphology after KLF5 knockdown. In combination with chromatin immunoprecipitation analysis and promoter study, our data show that KLF5 regulates intestinal barrier function by mediating the transcription of DSG2 , a gene encoding a major component of desmosome structures. NEW & NOTEWORTHY The study is original research on the direct function of a Krüppel-like factor on intestinal barrier function, which is commonly exerted by cell junctions, including tight junctions, adherens junctions, and desmosomes. Numerous previous studies were focused on tight junctions and adherens junctions. However, this study provided a new perspective on how the intestinal barrier function is regulated by KLF5 through DSG2, a component of desmosome complexes. Copyright © 2017 the American Physiological Society.

Overview of thermal barrier coatings in diesel engines

NASA Technical Reports Server (NTRS)

Yonushonis, Thomas M.

1995-01-01

An understanding of delamination mechanisms in thermal barrier coatings has been developed for diesel engine applications through rig tests, structural analysis modeling, nondestructive evaluation, and engine evaluation of various thermal barrier coatings. This knowledge has resulted in improved thermal barrier coatings which survive abusive cyclic fatigue tests in high output diesel engines. Although much conflicting literature now exists regarding the impact of thermal barrier coatings on engine performance and fuel consumption, the changes in fuel consumption appear to be less than a few percent and can be negative for state-of-the-art diesel engines. The ability of the thermal barrier coating to improve fuel economy tends to be dependent on a number of factors including the fuel injection system, combustion chamber design, and the initial engine fuel economy. Limited investigations on state-of-the-art diesel engines have indicated that the surface connected porosity and coating surface roughness may influence engine fuel economy. Current research efforts on thermal barrier coatings are primarily directed at reducing in-cylinder heat rejection, thermal fatigue protection of underlying metal surfaces and a possible reduction in diesel engine emissions. Significant efforts are still required to improve the plasma spray processing capability and the economics for complex geometry diesel engine components.

Effect of glutamine-enriched nutritional support on intestinal mucosal barrier function, MMP-2, MMP-9 and immune function in patients with advanced gastric cancer during perioperative chemotherapy.

PubMed

Wang, Juan; Li, Yanfen; Qi, Yuanling

2017-09-01

We studied the effects of glutamine-enriched nutritional support on intestinal mucosal barrier, matrix metalloproteinase (MMP)-2, MMP-9 and immune function during perioperative chemotherapy in patients with advanced gastric cancer. The study was conducted on 94 patients with advanced gastric cancer admitted from April 2015 to March 2016. They were randomly divided into observation and control groups, n=47. Control group was given basic nutritional support whereas glutamine-enriched nutritional support was given to patients in observation group. High-performance liquid chromatography was used to measure lactulose and mannitol ratio in urine (L/M) and ELISA was used to measure D-lactate levels before chemotherapy and in the 1st, 2nd and 3rd cycle of chemotherapy. Immunoglobulin level was detected by immune turbidimetry assay, T lymphocyte subsets were determined by flow cytometry after 3 cycles of chemotherapy, MMP-2 and MMP-9 of patients were compared between the two groups. The serious adverse reactions incidence (grade and IV) of patients were observed. To evaluate the life quality of patients, QLQ-C30 was used after 6 months. The levels of L/M and D-lactate in both groups after the first cycle of chemotherapy were significantly higher than that before chemotherapy; they began to decline after the second or third cycle, but were still significantly higher than the levels before chemotherapy (p<0.05). On comparison, between the two groups after 1st, 2nd, 3rd cycle after chemotherapy, L/M and D-lactate levels of patients in the observation group were significantly lower than in the control group (p<0.05). Incidence of serious adverse reactions (grades III and IV) in observation group was significantly lower than control group (p<0.05). At follow-up of 6 months, living quality scores of patients in observation group were significantly higher than control group (p<0.05). Glutamine-enriched nutritional support can effectively protect the intestinal mucosal barrier function in patients with advanced gastric cancer in their perioperative chemotherapy, improve the level of MMP-2 and MMP-9 in patients with advanced gastric cancer, enhance their immune function, reduce the incidence of adverse reactions and improve their quality of life, which is of remarkable clinical application value.

Nitride based quantum well light-emitting devices having improved current injection efficiency

DOEpatents

Tansu, Nelson; Zhao, Hongping; Liu, Guangyu; Arif, Ronald

2014-12-09

A III-nitride based device provides improved current injection efficiency by reducing thermionic carrier escape at high current density. The device includes a quantum well active layer and a pair of multi-layer barrier layers arranged symmetrically about the active layer. Each multi-layer barrier layer includes an inner layer abutting the active layer; and an outer layer abutting the inner layer. The inner barrier layer has a bandgap greater than that of the outer barrier layer. Both the inner and the outer barrier layer have bandgaps greater than that of the active layer. InGaN may be employed in the active layer, AlInN, AlInGaN or AlGaN may be employed in the inner barrier layer, and GaN may be employed in the outer barrier layer. Preferably, the inner layer is thin relative to the other layers. In one embodiment the inner barrier and active layers are 15 .ANG. and 24 .ANG. thick, respectively.

Delineation of Matriptase Protein Expression by Enzymatic Gene Trapping Suggests Diverging Roles in Barrier Function, Hair Formation, and Squamous Cell Carcinogenesis

PubMed Central

List, Karin; Szabo, Roman; Molinolo, Alfredo; Nielsen, Boye Schnack; Bugge, Thomas H.

2006-01-01

The membrane serine protease matriptase is required for epidermal barrier function, hair formation, and thymocyte development in mice, and dysregulated matriptase expression causes epidermal squamous cell carcinoma. To elucidate the specific functions of matriptase in normal and aberrant epidermal differentiation, we used enzymatic gene trapping combined with immunohistochemical, ultrastructural, and barrier function assays to delineate the spatio-temporal expression and function of matriptase in mouse keratinized tissue development, homeostasis, and malignant transformation. In the interfollicular epidermis, matriptase expression was restricted to postmitotic transitional layer keratinocytes undergoing terminal differentiation. Matriptase was also expressed in keratinizing oral epithelium, where it was required for oral barrier function, and in thymic epithelium. In all three tissues, matriptase colocalized with profilaggrin. In staged embryos, the onset of epidermal matriptase expression coincided with that of profilaggrin expression and acquisition of the epidermal barrier. In marked contrast to stratifying keritinized epithelium, matripase expression commenced already in undifferentiated and rapidly proliferating profilaggrin-negative matrix cells and displayed hair growth cycle-dependent expression. Exposure of the epidermis to carcinogens led to the gradual appearance of matriptase in a keratin-5-positive proliferative cell compartment during malignant progression. Combined with previous studies, these data suggest that matriptase has diverging functions in the genesis of stratified keratinized epithelium, hair follicles, and squamous cell carcinoma. PMID:16651618

Delineation of matriptase protein expression by enzymatic gene trapping suggests diverging roles in barrier function, hair formation, and squamous cell carcinogenesis.

PubMed

List, Karin; Szabo, Roman; Molinolo, Alfredo; Nielsen, Boye Schnack; Bugge, Thomas H

2006-05-01

The membrane serine protease matriptase is required for epidermal barrier function, hair formation, and thymocyte development in mice, and dysregulated matriptase expression causes epidermal squamous cell carcinoma. To elucidate the specific functions of matriptase in normal and aberrant epidermal differentiation, we used enzymatic gene trapping combined with immunohistochemical, ultrastructural, and barrier function assays to delineate the spatio-temporal expression and function of matriptase in mouse keratinized tissue development, homeostasis, and malignant transformation. In the interfollicular epidermis, matriptase expression was restricted to postmitotic transitional layer keratinocytes undergoing terminal differentiation. Matriptase was also expressed in keratinizing oral epithelium, where it was required for oral barrier function, and in thymic epithelium. In all three tissues, matriptase colocalized with profilaggrin. In staged embryos, the onset of epidermal matriptase expression coincided with that of profilaggrin expression and acquisition of the epidermal barrier. In marked contrast to stratifying keritinized epithelium, matripase expression commenced already in undifferentiated and rapidly proliferating profilaggrin-negative matrix cells and displayed hair growth cycle-dependent expression. Exposure of the epidermis to carcinogens led to the gradual appearance of matriptase in a keratin-5-positive proliferative cell compartment during malignant progression. Combined with previous studies, these data suggest that matriptase has diverging functions in the genesis of stratified keratinized epithelium, hair follicles, and squamous cell carcinoma.

Improving the light output power of DUV-LED by introducing an intrinsic last quantum barrier interlayer on the high-quality AlN template

NASA Astrophysics Data System (ADS)

Tsai, Chia-Lung; Liu, Hsueh-Hsing; Chen, Jun-Wei; Lu, Chien-Pin; Ikenaga, Kazutada; Tabuchi, Toshiya; Matsumoto, Koh; Fu, Yi-Keng

2017-12-01

We demonstrate that the light output power of deep ultraviolet light-emitting diodes (DUV-LEDs) can be improved by introducing an intrinsic last quantum barrier interlayer to a high quality AlN template. The light output power of the DUV-LEDs can be doubled by substituting the last quantum barrier with an intrinsic last quantum barrier (u-LQB)/Mg-doped LQB for only pure u-LQB in the same thickness with a 35 A/cm2 injection current. It is believed that the improved performance of the DUV LED could be attributed to the decreased diffusion of Mg tunneling into MQW and the reduction of sub-band parasitic emissions.

Ceramic thermal barrier coatings for commercial gas turbine engines

NASA Technical Reports Server (NTRS)

Meier, Susan Manning; Gupta, Dinesh K.; Sheffler, Keith D.

1991-01-01

The paper provides an overview of the short history, current status, and future prospects of ceramic thermal barrier coatings for gas turbine engines. Particular attention is given to plasma-sprayed and electron beam-physical vapor deposited yttria-stabilized (7 wt pct Y2O3) zirconia systems. Recent advances include improvements in the spallation life of thermal barrier coatings, improved bond coat composition and spraying techniques, and improved component design. The discussion also covers field experience, life prediction modeling, and future directions in ceramic coatings in relation to gas turbine engine design.

Novel Antitransferrin Receptor Antibodies Improve the Blood-Brain Barrier Crossing Efficacy of Immunoliposomes.

PubMed

Gregori, Maria; Orlando, Antonina; Re, Francesca; Sesana, Silvia; Nardo, Luca; Salerno, Domenico; Mantegazza, Francesco; Salvati, Elisa; Zito, Andrea; Malavasi, Fabio; Masserini, Massimo; Cazzaniga, Emanuela

2016-01-01

Surface functionalization with antitransferrin receptor (TfR) mAbs has been suggested as the strategy to enhance the transfer of nanoparticles (NPs) across the blood-brain barrier (BBB) and to carry nonpermeant drugs from the blood into the brain. However, the efficiency of BBB crossing is currently too poor to be used in vivo. In the present investigation, we compared 6 different murine mAbs specific for different epitopes of the human TfR to identify the best performing one for the functionalization of NPs. For this purpose, we compared the ability of mAbs to cross an in vitro BBB model made of human brain capillary endothelial cells (hCMEC/D3). Liposomes functionalized with the best performing mAb (MYBE/4C1) were uptaken, crossed the BBB in vitro, and facilitated the BBB in vitro passage of doxorubicin, an anticancer drug, 3.9 folds more than liposomes functionalized with a nonspecific IgG, as assessed by confocal microscopy, radiochemical techniques, and fluorescence, and did not modify the cell monolayer structural or functional properties. These results show that MYBE/4C1 antihuman TfR mAb is a powerful resource for the enhancement of BBB crossing of NPs and is therefore potentially useful in the treatment of neurologic diseases and disorders including brain carcinomas. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Financial burdens and barriers to care among nonelderly adults: The role of functional limitations and chronic conditions.

PubMed

Bernard, Didem; Selden, Thomas; Yeh, Susan

2016-04-01

People with functional limitations and chronic conditions account for the greatest resource use within the health care system. To examine financial burdens and barriers to care among nonelderly adults, focusing on the role of functional limitations and chronic conditions. High financial burden is defined as medical spending exceeding 20 percent of family income. Financial barriers are defined as delaying care/being unable to get care for financial reasons, and reporting that delaying care/going without was a big problem. Data are from the Medical Expenditure Panel Survey (2008-2012). Functional limitations are associated with increased prevalence of financial burdens. Among single adults, the frequency of high burdens is 20.3% for those with functional limitations, versus 7.8% for those without. Among those with functional limitations, those with 3 or more chronic conditions are twice as likely to have high burdens compared to those without chronic conditions (22.2% versus 11.1%, respectively). Similar patterns occur among persons in multi-person families whose members have functional limitations and chronic conditions. Having functional limitations and chronic conditions is also strongly associated with financial barriers to care: 40.2% among the uninsured, 21.9% among those with public coverage, and 13.6% among those with private group insurance were unable to get care. Functional limitations and chronic conditions are associated with increased prevalence of burdens and financial barriers in all insurance categories, with the exception that an association between functional limitations and the prevalence of burdens was not observed for public coverage. Published by Elsevier Inc.

Fusion enhancement at near and sub-barrier energies in 19O + 12C

DOE PAGES

Singh, Varinderjit; Vadas, J.; Steinbach, T. K.; ...

2016-12-12

Measuring the fusion excitation function for an isotopic chain of projectile nuclei provides a stringent test of a microscopic description of fusion. We report the first measurement of the fusion excitation function at near-barrier energies for the 19O+ 12C system. The measured excitation function is compared with the fusion excitation function of 18O+ 12C. A significant enhancement in the fusion probability of 19O ions with a 12C target as compared to 18O ions is observed. As a result, the experimental cross-sections observed at near-barrier energies are compared with a state-of-the-art microscopic model.

A framework for understanding semi-permeable barrier effects on migratory ungulates

USGS Publications Warehouse

Sawyer, Hall; Kauffman, Matthew J.; Middleton, Arthur D.; Morrison, Thomas A.; Nielson, Ryan M.; Wyckoff, Teal B.

2013-01-01

1. Impermeable barriers to migration can greatly constrain the set of possible routes and ranges used by migrating animals. For ungulates, however, many forms of development are semi-permeable, and making informed management decisions about their potential impacts to the persistence of migration routes is difficult because our knowledge of how semi-permeable barriers affect migratory behaviour and function is limited. 2. Here, we propose a general framework to advance the understanding of barrier effects on ungulate migration by emphasizing the need to (i) quantify potential barriers in terms that allow behavioural thresholds to be considered, (ii) identify and measure behavioural responses to semi-permeable barriers and (iii) consider the functional attributes of the migratory landscape (e.g. stopovers) and how the benefits of migration might be reduced by behavioural changes. 3. We used global position system (GPS) data collected from two subpopulations of mule deer Odocoileus hemionus to evaluate how different levels of gas development influenced migratory behaviour, including movement rates and stopover use at the individual level, and intensity of use and width of migration route at the population level. We then characterized the functional landscape of migration routes as either stopover habitat or movement corridors and examined how the observed behavioural changes affected the functionality of the migration route in terms of stopover use. 4. We found migratory behaviour to vary with development intensity. Our results suggest that mule deer can migrate through moderate levels of development without any noticeable effects on migratory behaviour. However, in areas with more intensive development, animals often detoured from established routes, increased their rate of movement and reduced stopover use, while the overall use and width of migration routes decreased. 5. Synthesis and applications. In contrast to impermeable barriers that impede animal movement, semi-permeable barriers allow animals to maintain connectivity between their seasonal ranges. Our results identify the mechanisms (e.g. detouring, increased movement rates, reduced stopover use) by which semi-permeable barriers affect the functionality of ungulate migration routes and emphasize that the management of semi-permeable barriers may play a key role in the conservation of migratory ungulate populations.

Provider perspectives on barriers and facilitators to adjuvant endocrine therapy-related symptom management.

PubMed

Samuel, Cleo A; Turner, Kea; Donovan, Heidi A S; Beckjord, Ellen; Cardy, Alexandra; Dew, Mary Amanda; van Londen, G J

2017-12-01

Adjuvant endocrine therapy (AET) utilization is linked to improved clinical outcomes among breast cancer survivors (BCS); yet, AET adherence rates remain suboptimal. Little is known about provider perspectives regarding barriers and facilitators to AET-related symptom management (SM). In this study, we examined provider perspectives on the barriers and facilitators to AET-related SM among BCS and opportunities for improvement. We conducted three focus groups (FGs) with a multidisciplinary group of healthcare providers (n = 13) experienced in caring for BCS undergoing AET. We utilized semi-structured discussion guides to elicit provider perspectives on AET-related SM. FGs were audiotaped, transcribed, and analyzed using qualitative software to identify key themes. Providers described patient-, provider-, and system-level barriers and facilitators to AET-related SM. At the patient-level, barriers included competing demands, limited time/resources, and possible misattribution of some symptoms to AET, while family/social relationships and insurance emerged as important facilitators. Discomfort with SM, limited time, and challenges distinguishing AET-related symptoms from other conditions were key provider-level barriers. Provider-level facilitators included routine symptom documentation and strong provider relationships. Care fragmentation and complexity of the cancer care delivery system were described as system-level barriers; however, survivor clinics were endorsed by providers. Provider perspectives on AET-related SM can shed light on SM barriers and facilitators spanning multiple levels of the cancer care delivery system. Strategies for improving AET-related SM in BCS include increasing patients' knowledge and engagement in SM, equipping providers with efficient SM strategies, and improving coordination of symptom-related services through survivorship programs.

Quantum finance Hamiltonian for coupon bond European and barrier options.

PubMed

Baaquie, Belal E

2008-03-01

Coupon bond European and barrier options are financial derivatives that can be analyzed in the Hamiltonian formulation of quantum finance. Forward interest rates are modeled as a two-dimensional quantum field theory and its Hamiltonian and state space is defined. European and barrier options are realized as transition amplitudes of the time integrated Hamiltonian operator. The double barrier option for a financial instrument is "knocked out" (terminated with zero value) if the price of the underlying instrument exceeds or falls below preset limits; the barrier option is realized by imposing boundary conditions on the eigenfunctions of the forward interest rates' Hamiltonian. The price of the European coupon bond option and the zero coupon bond barrier option are calculated. It is shown that, is general, the constraint function for a coupon bond barrier option can -- to a good approximation -- be linearized. A calculation using an overcomplete set of eigenfunctions yields an approximate price for the coupon bond barrier option, which is given in the form of an integral of a factor that results from the barrier condition times another factor that arises from the payoff function.

Improving operating room efficiency by applying bin-packing and portfolio techniques to surgical case scheduling.

PubMed

Van Houdenhoven, Mark; van Oostrum, Jeroen M; Hans, Erwin W; Wullink, Gerhard; Kazemier, Geert

2007-09-01

An operating room (OR) department has adopted an efficient business model and subsequently investigated how efficiency could be further improved. The aim of this study is to show the efficiency improvement of lowering organizational barriers and applying advanced mathematical techniques. We applied advanced mathematical algorithms in combination with scenarios that model relaxation of various organizational barriers using prospectively collected data. The setting is the main inpatient OR department of a university hospital, which sets its surgical case schedules 2 wk in advance using a block planning method. The main outcome measures are the number of freed OR blocks and OR utilization. Lowering organizational barriers and applying mathematical algorithms can yield a 4.5% point increase in OR utilization (95% confidence interval 4.0%-5.0%). This is obtained by reducing the total required OR time. Efficient OR departments can further improve their efficiency. The paper shows that a radical cultural change that comprises the use of mathematical algorithms and lowering organizational barriers improves OR utilization.

Rho kinase inhibition following traumatic brain injury in mice promotes functional improvement and acute neuron survival but has little effect on neurogenesis, glial responses or neuroinflammation.

PubMed

Bye, Nicole; Christie, Kimberly J; Turbic, Alisa; Basrai, Harleen S; Turnley, Ann M

2016-05-01

Inhibition of the Rho/Rho kinase pathway has been shown to be beneficial in a variety of neural injuries and diseases. In this manuscript we investigate the role of Rho kinase inhibition in recovery from traumatic brain injury using a controlled cortical impact model in mice. Mice subjected to a moderately severe TBI were treated for 1 or 4 weeks with the Rho kinase inhibitor Y27632, and functional outcomes and neuronal and glial cell responses were analysed at 1, 7 and 35 days post-injury. We hypothesised that Y27632-treated mice would show functional improvement, with augmented recruitment of neuroblasts from the SVZ and enhanced survival of newborn neurons in the pericontusional cortex, with protection against neuronal degeneration, neuroinflammation and modulation of astrocyte reactivity and blood-brain-barrier permeability. While Rho kinase inhibition enhanced recovery of motor function after trauma, there were no substantial increases in the recruitment of DCX(+) neuroblasts or the number of BrdU(+) or EdU(+) labelled newborn neurons in the pericontusional cortex of Y27632-treated mice. Inhibition of Rho kinase significantly reduced the number of degenerating cortical neurons at 1day post-injury compared to saline controls but had no longer term effect on neuronal degeneration, with only modest effects on astrocytic reactivity and macrophage/microglial responses. Overall, this study showed that Rho kinase contributes to acute neurodegenerative processes in the injured cortex but does not play a significant role in SVZ neural precursor cell-derived adult neurogenesis, glial responses or blood-brain barrier permeability following a moderately severe brain injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Reducing Barriers to Care in the Office-Based Health Care Setting for Children With Autism.

PubMed

Bultas, Margaret W; McMillin, Stephen Edward; Zand, Debra H

2016-01-01

The purpose of this survey-design research study was to evaluate the usefulness of a researcher-developed tool designed to improve office-based health care services and to assess the barriers and resources affecting office-based health care services for children with autism spectrum disorder. Fifty-four health care providers (HCPs) and 59 parents participated in the study. HCPs reported child behaviors, communication, and fears as barriers to providing care, whereas parents reported child behavior, sensory issues, and feelings of a disconnect with the HCP as barriers. HCPs identified the parent as a key resource. Parent-identified resources included provider adaptations to the patient, including slowing down the delivery of care and environmental adaptations to the office. In addition, both HCPs and parents indicated that the researcher-developed tool would be useful in reducing barriers during the HCE. Reducing barriers and improving health care interactions during delivery of care for children with autism spectrum disorder has the potential to improve health outcomes. Copyright © 2016 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

A qualitative theory guided analysis of stroke survivors' perceived barriers and facilitators to physical activity.

PubMed

Nicholson, Sarah L; Donaghy, Marie; Johnston, Marie; Sniehotta, Falko F; van Wijck, Frederike; Johnston, Derek; Greig, Carolyn; McMurdo, Marion E T; Mead, Gillian

2014-01-01

After stroke, physical activity and physical fitness levels are low, impacting on health, activity and participation. It is unclear how best to support stroke survivors to increase physical activity. Little is known about the barriers and facilitators to physical activity after stroke. Thus, our aim was to explore stroke survivors' perceived barriers and facilitators to physical activity. Semi-structured interviews with 13 ambulatory stroke survivors exploring perceived barriers and facilitators to physical activity post stroke were conducted in participants' homes, audio-recorded and transcribed verbatim. The Theoretical Domains Framework (TDF) informed content analysis of the interview transcripts. Data saturation was reached after interviews with 13 participants (median age of 76 years (inter-quartile range (IQR) = 69-83 years). The median time since stroke was 345 d (IQR = 316-366 d). The most commonly reported TDF domains were "beliefs about capabilities", "environmental context and resources" and "social influence". The most commonly reported perceived motivators were: social interaction, beliefs of benefits of exercise, high self-efficacy and the necessity of routine behaviours. The most commonly reported perceived barriers were: lack of professional support on discharge from hospital and follow-up, transport issues to structured classes/interventions, lack of control and negative affect. Stroke survivors perceive several different barriers and facilitators to physical activity. Stroke services need to address barriers to physical activity and to build on facilitators to promote physical activity after stroke. Physical activity post stroke can improve physical fitness and function, yet physical activity remains low among stroke survivors. Understanding stroke survivors' perceived barriers and facilitators to physical activity is essential to develop targeted interventions to increase physical activity. Beliefs about capabilities, environmental context and resources and social influences were the mostly commonly report influences on stroke survivors' perceived barriers and facilitators to physical activity.

Oral intake of beet extract provides protection against skin barrier impairment in hairless mice.

PubMed

Kawano, Ken-Ichi; Umemura, Kazuo

2013-05-01

The epidermis acts as a functional barrier against the external environment. Disturbances in the function of this barrier cause water loss and increase the chances of penetration by various irritable stimuli, leading to skin diseases such as dry skin, atopic dermatitis, and psoriasis. Ceramides are a critical natural element of the protective epidermal barrier. The aim of this study was to evaluate whether the oral intake of beet (Beta vulgaris) extract, a natural product rich in glucosylceramide (GlcCer), may prevent disturbance in skin barrier function. When HR-1 hairless mice were fed a special diet (HR-AD), transepidermal water loss (TEWL) from the dorsal skin increased, with a compensatory increase in water intake after 5 weeks. Mice fed with HR-AD had dry skin with erythema and showed increased scratching behaviour. Histological examinations revealed a remarkable increase in the thickness of the skin at 8 weeks. Supplemental addition of beet extract, which contained GlcCer at a final concentration of 0.1%, significantly prevented an increase TEWL, water intake, cumulative scratching time, and epidermal thickness at 8 weeks. These results indicate that oral intake of beet extract shows potential for preventing skin diseases associated with impaired skin barrier function. Copyright © 2012 John Wiley & Sons, Ltd.

Performance investigation of bandgap, gate material work function and gate dielectric engineered TFET with device reliability improvement

NASA Astrophysics Data System (ADS)

Raad, Bhagwan Ram; Nigam, Kaushal; Sharma, Dheeraj; Kondekar, P. N.

2016-06-01

This script features a study of bandgap, gate material work function and gate dielectric engineering for enhancement of DC and Analog/RF performance, reduction in the hot carriers effect (HCEs) and drain induced barrier lowering (DIBL) for better device reliability. In this concern, the use of band gap and gate material work function engineering improves the device performance in terms of the ON-state current and suppressed ambipolar behaviour with maintaining the low OFF-state current. With these advantages, the use of gate material work function engineering imposes restriction on the high frequency performance due to increment in the parasitic capacitances and also introduces the hot carrier effects. Hence, the gate dielectric engineering with bandgap and gate material work function engineering are used in this paper to overcome the cons of the gate material work function engineering by obtaining a superior performance in terms of the current driving capability, ambipolar conduction, HCEs, DIBL and high frequency parameters of the device for ultra-low power applications. Finally, the optimization of length for different work function is performed to get the best out of this.

Barriers to HIV testing among male clients of female sex workers in Indonesia.

PubMed

Fauk, Nelsensius Klau; Sukmawati, Anastasia Suci; Berek, Pius Almindu Leki; Ernawati; Kristanti, Elisabeth; Wardojo, Sri Sunaringsih Ika; Cahaya, Isaias Budi; Mwanri, Lillian

2018-05-30

Frequent engagement of men in sexual encounters with female sex workers (FSWs) without using condoms places them at a high risk for HIV infection. HIV testing has been noted to be among important strategies to prevent HIV transmission and acquisition. However, it is known that not all men willingly undertake an HIV test as a way to prevent HIV transmission and/or acquisition. This study aimed to identify barriers to accessing HIV testing services among men who are clients of FSWs (clients) in Belu and Malaka districts, Indonesia. A qualitative inquiry employing face to face open ended interviews was conducted from January to April 2017. The participants (n = 42) were clients of FSWs recruited using purposive and snowball sampling techniques. Data were analysed using a qualitative data analysis framework. Findings indicated three main barriers of accessing HIV testing services by clients. These included: (1) personal barriers (lack of knowledge of HIV/AIDS and HIV testing availability, and unwillingness to undergo HIV testing due to low self-perceived risk of HIV and fear of the test result); (2) health care service provision barriers (lack of trust in health professionals and limited availability of medication including antiretroviral (ARV)); and (3) social barriers (stigma and discrimination, and the lack of social supports). These findings indicated multilevelled barriers to accessing HIV testing services among participants, who are known to be among key population groups in HIV care. Actions to improve HIV/AIDS-related health services accessibility are required. The dissemination of the knowledge and information on HIV/AIDS and improved available of HIV/AIDS-related services are necessary actions to improve the personal levelled barriers. System wide barriers will need improved practices and health policies to provide patients friendly and accessible services. The societal levelled barriers will need a more broad societal approach including raising awareness in the community and enhanced discussions about HIV/AIDS issues in order to normalise HIV in the society.

Multilayer thermal barrier coating systems

DOEpatents

Vance, Steven J.; Goedjen, John G.; Sabol, Stephen M.; Sloan, Kelly M.

2000-01-01

The present invention generally describes multilayer thermal barrier coating systems and methods of making the multilayer thermal barrier coating systems. The thermal barrier coating systems comprise a first ceramic layer, a second ceramic layer, a thermally grown oxide layer, a metallic bond coating layer and a substrate. The thermal barrier coating systems have improved high temperature thermal and chemical stability for use in gas turbine applications.

Evaluation of the efficacy and safety of a CS20® protective barrier gel containing OGT compared with topical aciclovir and placebo on functional and objective symptoms of labial herpes recurrences: a randomized clinical trial.

PubMed

Khemis, A; Duteil, L; Coudert, A C; Tillet, Y; Dereure, O; Ortonne, J P

2012-10-01

Topical or systemic antiviral drugs reduce the duration of herpes simplex virus 1 (HSV-1) recurrences but may not alleviate functional symptoms. To assess the efficacy and safety of CS20 (Acura 24(®) ) protective barrier gel versus topical aciclovir and placebo in resolving functional symptoms in HSV-1 labial recurrences. A prospective, randomized, single-centre, assessor-blinded study of CS20 versus topical aciclovir or placebo. The primary endpoint was the total score of four herpes-related functional symptoms (pain, burning, itching, and tingling sensations), evaluated by visual analogue scale (VAS). Secondary endpoints encompassed objective skin changes (oedema, crusting and erythema), evaluated by specific clinical scores. In a study of 106 patients, compared with placebo, a significant improvement in total functional symptom score was observed after 1 day of treatment in the CS20 group, but only after 7 days of treatment in the topical aciclovir group. Burning sensations were significantly reduced by CS20 compared with aciclovir (Days 1-2) or placebo (Days 1-7). Compared to placebo, CS20 significantly reduced pain intensity on Days 1-6. CS20 induced significant and early improvements in the clinical scores for oedema and crusting compared with placebo. Time to cure was similar for CS20 and aciclovir. The treatments were well tolerated and adverse events were comparable in the three treatment groups. Limitations  The single-centre and single-blind design of the study and the preselection of patients. CS20 showed superior effectiveness against functional symptoms (pain and burning) associated with HSV-1 labial recurrences and was similar to aciclovir for time to cure. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

Distribution and Biological Effects of Nanoparticles in the Reproductive System.

PubMed

Liu, Ying; Li, Hongxia; Xiao, Kai

2016-01-01

Nanoparticles have shown great potential in biomedical applications such as imaging probes and drug delivery. However, the increasing use of nanoparticles has raised concerns about their adverse effects on human health and environment. Reproductive tissues and gametes represent highly delicate biological systems with the essential function of transmitting genetic information to the offspring, which is highly sensitive to environmental toxicants. This review aims to summarzie the penetration of physiological barriers (blood-testis barrier and placental barrier), distribution and biological effects of nanoparticles in the reproductive system, which is essential to control the beneficial effects of nanoparticles applications and to avoid their adverse effects on the reproductive system. We referred to a large number of relevant peer-reviewed research articles about the reproductive toxicity of nanoparticles. The comprehensive information was summarized into two parts: physiological barrier penetration and biological effects of nanoparticles in male or female reproductive system; distribution and metabolism of nanoparticles in the reproductive system. The representative examples were also presented in four tables. The in vitro and in vivo studies imply that some nanoparticles are able to cross the blood-testis barrier or placental barrier, and their penetration depends on the physicochemical characteristics of nanoparticles (e.g., composition, shape, particle size and surface coating). The toxicity assays indicate that nanoparticles might induce adverse physiological effects and impede fertility or embryogenesis. The barrier penetration, adverse physiological effects, distribution and metabolism are closely related to physicochemical characteristics of nanoparticles. Further systematic and mechanistic studies using well-characterized nanoparticles, relevant administration routes, and doses relevant to the expected exposure level are required to improve our understanding of biological effects of nanoparticles on the reproductive system.

Perceived barriers to utilizing maternal and neonatal health services in contracted-out versus government-managed health facilities in the rural districts of Pakistan.

PubMed

Riaz, Atif; Zaidi, Shehla; Khowaja, Asif Raza

2015-03-06

A number of developing countries have contracted out public health facilities to the Non-Government Organizations (NGOs) in order to improve service utilization. However, there is a paucity of in-depth qualitative information on barriers to access services as a result of contracting from service users' perspective. The objective of this study was to explore perceived barriers to utilizing Maternal and Neonatal Health (MNH) services, in health facilities contracted out by government to NGO for service provision versus in those which are managed by government (non-contracted). A community-based qualitative exploratory study was conducted between April to September 2012 at two contracted-out and four matched non-contracted primary healthcare facilities in Thatta and Chitral, rural districts of Pakistan. Using semi-structured guide, the data were collected through thirty-six Focus Group Discussions (FGDs) conducted with mothers and their spouses in the catchment areas of selected facilities. Thematic analysis was performed using NVivo version 10.0 in which themes and sub-themes emerged. Key barriers reported in contracted sites included physical distance, user charges and familial influences. Whereas, poor functionality of health centres was the main barrier for non-contracted sites with other issues being comparatively less salient. Decision-making patterns for participants of both catchments were largely similar. Spouses and mother-in-laws particularly influenced the decision to utilize health facilities. Contracting out of health facility reduces supply side barriers to MNH services for the community served but distance, user charges and low awareness remain significant barriers. Contracting needs to be accompanied by measures for transportation in remote settings, oversight on user fee charges by contractor, and strong community-based behavior change strategies. © 2015 by Kerman University of Medical Sciences.

Comparative study on the deposition of silicon oxide permeation barrier coatings for polymers using hexamethyldisilazane (HMDSN) and hexamethyldisiloxane (HMDSO)

NASA Astrophysics Data System (ADS)

Mitschker, F.; Schücke, L.; Hoppe, Ch; Jaritz, M.; Dahlmann, R.; de los Arcos, T.; Hopmann, Ch; Grundmeier, G.; Awakowicz, P.

2018-06-01

The effect of the selection of hexamethyldisiloxane (HMDSO) and hexamethyldisilazane (HMDSN) as a precursor in a microwave driven low pressure plasma on the deposition of silicon oxide barrier coatings and silicon based organic interlayers on polyethylene terephthalate (PET) and polypropylene (PP) substrates is investigated. Mass spectrometry is used to quantify the absolute gas density and the degree of depletion of neutral precursor molecules under variation of oxygen admixture. On average, HMDSN shows a smaller density, a higher depletion and the production of smaller fragments. Subsequently, this is correlated with barrier performance and chemical structure as a function of barrier layer thickness and oxygen admixture on PET. For this purpose, the oxygen transmission rate (OTR) is measured and Fourier transformed infrared (FTIR) spectroscopy as well as x-ray photoelectron spectroscopy (XPS) is performed. HMDSN based coatings exhibit significantly higher barrier performances for high admixtures of oxygen (200 sccm). In comparison to HMDSO based processes, however, a higher supply of oxygen is necessary to achieve a sufficient degree of oxidation, cross-linking and, therefore, barrier performance. FTIR and XPS reveal a distinct carbon content for low oxygen admixtures (10 and 20 sccm) in case of HMDSN based coatings. The variation of interlayer thickness also reveals significantly higher OTR for HMDSO based coatings on PET and PP. Barrier performance of HMDSO based coatings improves with increasing interlayer thickness up to 10 nm for PET and PP. HMDSN based coatings exhibit a minimum of OTR without interlayer on PP and for 2 nm interlayer thickness on PET. Furthermore, HMDSN based coatings show distinctly higher bond strengths to the PP substrate.

Perceived barriers to utilizing maternal and neonatal health services in contracted-out versus government-managed health facilities in the rural districts of Pakistan

PubMed Central

Riaz, Atif; Zaidi, Shehla; Khowaja, Asif Raza

2015-01-01

Background: A number of developing countries have contracted out public health facilities to the Non-Government Organizations (NGOs) in order to improve service utilization. However, there is a paucity of in-depth qualitative information on barriers to access services as a result of contracting from service users’ perspective. The objective of this study was to explore perceived barriers to utilizing Maternal and Neonatal Health (MNH) services, in health facilities contracted out by government to NGO for service provision versus in those which are managed by government (non-contracted). Methods: A community-based qualitative exploratory study was conducted between April to September 2012 at two contracted-out and four matched non-contracted primary healthcare facilities in Thatta and Chitral, rural districts of Pakistan. Using semi-structured guide, the data were collected through thirty-six Focus Group Discussions (FGDs) conducted with mothers and their spouses in the catchment areas of selected facilities. Thematic analysis was performed using NVivo version 10.0 in which themes and sub-themes emerged. Results: Key barriers reported in contracted sites included physical distance, user charges and familial influences. Whereas, poor functionality of health centres was the main barrier for non-contracted sites with other issues being comparatively less salient. Decision-making patterns for participants of both catchments were largely similar. Spouses and mother-in-laws particularly influenced the decision to utilize health facilities. Conclusion: Contracting out of health facility reduces supply side barriers to MNH services for the community served but distance, user charges and low awareness remain significant barriers. Contracting needs to be accompanied by measures for transportation in remote settings, oversight on user fee charges by contractor, and strong community-based behavior change strategies. PMID:25905478

The relationship between skin function, barrier properties, and body-dependent factors.

PubMed

Dąbrowska, A K; Spano, F; Derler, S; Adlhart, C; Spencer, N D; Rossi, R M

2018-05-01

Skin is a multilayer interface between the body and the environment, responsible for many important functions, such as temperature regulation, water transport, sensation, and protection from external triggers. This paper provides an overview of principal factors that influence human skin and describes the diversity of skin characteristics, its causes and possible consequences. It also discusses limitations in the barrier function of the skin, describing mechanisms of absorption. There are a number of in vivo investigations focusing on the diversity of human skin characteristics with reference to barrier properties and body-dependent factors. Skin properties vary among individuals of different age, gender, ethnicity, and skin types. In addition, skin characteristics differ depending on the body site and can be influenced by the body-mass index and lifestyle. Although one of the main functions of the skin is to act as a barrier, absorption of some substances remains possible. Various factors can alter human skin properties, which can be reflected in skin function and the quality of everyday life. Skin properties and function are strongly interlinked. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The 24-hour skin hydration and barrier function effects of a hyaluronic 1%, glycerin 5%, and Centella asiatica stem cells extract moisturizing fluid: an intra-subject, randomized, assessor-blinded study.

PubMed

Milani, Massimo; Sparavigna, Adele

2017-01-01

Moisturizing products are commonly used to improve hydration in skin dryness conditions. However, some topical hydrating products could have negative effects on skin barrier function. In addition, hydrating effects of moisturizers are not commonly evaluated up to 24 hours after a single application. Hyaluronic acid (HA) and glycerin are very well-known substances able to improve skin hydration. Centella asiatica extract (CAE) could exert lenitive, anti-inflammatory and reepithelialization actions. Furthermore, CAE could inhibit hyaluronidase enzyme activity, therefore prolonging the effect of HA. A fluid containing HA 1%, glycerin 5% and stem cells CAE has been recently developed (Jaluronius CS [JCS] fluid). To evaluate and compare the 24-hour effects of JCS fluid on skin hydration and on transepidermal water loss (TEWL) in healthy subjects in comparison with the control site. Twenty healthy women, mean age 40 years, were enrolled in an intra-subject (right vs left), randomized, assessor-blinded, controlled, 1-day trial. The primary end points were the skin hydration and TEWL, evaluated at the volar surface of the forearm and in standardized conditions (temperature- and humidity-controlled room: 23°C and 30% of humidity) using a corneometer and a vapometer device at baseline, 1, 8 and 24 hours after JCS fluid application. Measurements were performed by an operator blinded for the treatments. Skin hydration after 24 hours was significantly higher ( P =0.001; Mann-Whitney U test) in the JCS-treated area in comparison with the control site. JCS induced a significant ( P =0.0001) increase in skin hydration at each evaluation time (+59% after 1 hour, +48% after 8 hours and +29% after 24 hours) in comparison with both baseline ( P =0.0001) and non-treated control site ( P =0.001). TEWL after 24 hours was significantly lower ( P =0.049; Mann-Whitney U test) in the JCS-treated area in comparison with the control site (13±4 arbitrary units [AU] vs 16±6 AU). JCS fluid significantly reduced post-stripping TEWL in comparison with baseline after 1, 8 and 24 hours (-52%, -32% and -48%, respectively). In the control site, TEWL was not reduced in comparison with baseline values at each time point's evaluation. A single application of JCS significantly improves skin hydration for up to 24 hours at the same time as improving skin barrier function.

Enhanced Ligand Sampling for Relative Protein–Ligand Binding Free Energy Calculations

PubMed Central

2016-01-01

Free energy calculations are used to study how strongly potential drug molecules interact with their target receptors. The accuracy of these calculations depends on the accuracy of the molecular dynamics (MD) force field as well as proper sampling of the major conformations of each molecule. However, proper sampling of ligand conformations can be difficult when there are large barriers separating the major ligand conformations. An example of this is for ligands with an asymmetrically substituted phenyl ring, where the presence of protein loops hinders the proper sampling of the different ring conformations. These ring conformations become more difficult to sample when the size of the functional groups attached to the ring increases. The Adaptive Integration Method (AIM) has been developed, which adaptively changes the alchemical coupling parameter λ during the MD simulation so that conformations sampled at one λ can aid sampling at the other λ values. The Accelerated Adaptive Integration Method (AcclAIM) builds on AIM by lowering potential barriers for specific degrees of freedom at intermediate λ values. However, these methods may not work when there are very large barriers separating the major ligand conformations. In this work, we describe a modification to AIM that improves sampling of the different ring conformations, even when there is a very large barrier between them. This method combines AIM with conformational Monte Carlo sampling, giving improved convergence of ring populations and the resulting free energy. This method, called AIM/MC, is applied to study the relative binding free energy for a pair of ligands that bind to thrombin and a different pair of ligands that bind to aspartyl protease β-APP cleaving enzyme 1 (BACE1). These protein–ligand binding free energy calculations illustrate the improvements in conformational sampling and the convergence of the free energy compared to both AIM and AcclAIM. PMID:25906170

Patient centered care: A path to better health outcomes through engagement and activation.

PubMed

Miller, Kenneth L

2016-10-14

Patient Activation and Health confidence are constructs to assess patient engagement and are utilized to encourage patient engagement. A health care provider may increase patient engagement further by utilizing behavior change theories and models such as the Trans-Theoretical Model of Change (TTM), Self-Determination Theory (SDT) and Motivational Interviewing (MI) to realize effective and lasting health behavior change by placing accountability increasingly on the patient/caregiver to choose to make changes in their health behavior on their terms. Reducing or eliminating harmful behaviors such as smoking and/or beginning or increasing beneficial health behaviors such as diet modification or performance of an exercise program, patients realize improved outcomes and better health. The purpose of this article is to define health confidence as a measurement tool for patient engagement, use the TTM as a measure of the patient's readiness to change, use TTM, SDT and MI as interventional approaches to effect patient change of behavior encouraged by physical therapists and incorporate the ICF as a means of identifying barriers and facilitators and incorporate the bio-psychosocial model for patient-centered care to improve health behavior, health and patient outcomes. Patient-centered care requires involvement of the patient and/or their caregiver at the center of the plan. Use of the International Classification of Functioning, Disability and Health (ICF) to identify facilitators and barriers unique to the patient/caregiver offers another opportunity to successfully engage the patient by incorporating the patient's bio-psychosocial support system into care delivery and for sustainability. The ICF is a taxonomy and classification system that prompts clinicians to identify environmental factors (facilitators and barriers) that will influence the patient's ability to perform during therapy session and to sustain the interventions and employ suggestions outside of formal therapy sessions. Using the facilitators to encourage sustainable change and removing barriers, patients are more likely to realize positive health behavior change and in turn demonstrate improved outcomes and health as a result of physical therapy intervention.

Where to Restore Ecological Connectivity? Detecting Barriers and Quantifying Restoration Benefits

PubMed Central

McRae, Brad H.; Hall, Sonia A.; Beier, Paul; Theobald, David M.

2012-01-01

Landscape connectivity is crucial for many ecological processes, including dispersal, gene flow, demographic rescue, and movement in response to climate change. As a result, governmental and non-governmental organizations are focusing efforts to map and conserve areas that facilitate movement to maintain population connectivity and promote climate adaptation. In contrast, little focus has been placed on identifying barriers—landscape features which impede movement between ecologically important areas—where restoration could most improve connectivity. Yet knowing where barriers most strongly reduce connectivity can complement traditional analyses aimed at mapping best movement routes. We introduce a novel method to detect important barriers and provide example applications. Our method uses GIS neighborhood analyses in conjunction with effective distance analyses to detect barriers that, if removed, would significantly improve connectivity. Applicable in least-cost, circuit-theoretic, and simulation modeling frameworks, the method detects both complete (impermeable) barriers and those that impede but do not completely block movement. Barrier mapping complements corridor mapping by broadening the range of connectivity conservation alternatives available to practitioners. The method can help practitioners move beyond maintaining currently important areas to restoring and enhancing connectivity through active barrier removal. It can inform decisions on trade-offs between restoration and protection; for example, purchasing an intact corridor may be substantially more costly than restoring a barrier that blocks an alternative corridor. And it extends the concept of centrality to barriers, highlighting areas that most diminish connectivity across broad networks. Identifying which modeled barriers have the greatest impact can also help prioritize error checking of land cover data and collection of field data to improve connectivity maps. Barrier detection provides a different way to view the landscape, broadening thinking about connectivity and fragmentation while increasing conservation options. PMID:23300719

An Analysis of Stream Culvert Fish Passage on the Navy Railroad Line between Bremerton and Shelton, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Christopher W.; Miller, Martin C.; Southard, John A.

2004-10-25

The Navy railroad service line runs between Shelton, Bremerton, and Silverdale, and is used by the Navy to transfer freight to its facilities. It is also used by commercial clients to ship service items and bulk cargo for municipalities along portions of the route. Culverts of various size and construction convey streams and stormwater runoff under the railroad line. These allow transfer of water and, in some cases allow for passage of juvenile and adult salmon into waters upstream of the culverts. As part of this project, 21 culverts along a 34-mile reach (Shelton to Bremerton) of this railroad weremore » surveyed to evaluate their function and ability to allow salmon to utilize the streams. The culverts and attached watersheds were evaluated using criteria developed by the Washington Department of Fish and Wildlife to assign a Priority Index (PI) to barriers present on each fish-bearing stream. The PI is a relative numeric rating indicator, assigned using consistent criteria related to the degree of potential habitat gained by removing barriers and improving the function of the watershed. Of the 21 culverts evaluated, five were found to be complete fish-passage barriers and six were found to be partial barriers, primarily to juvenile salmon. Three of these culverts had PI ratings above 10 and five others had ratings between 7 and 10. Corrective action can be taken based on any PI rating, but the WDFW normally assigns lower priority to projects with PI scores lower than 15. Several of the stream and culverts had previously been evaluated for structural integrity and function and have been scheduled for repair. A narrative indicating the condition of the culvert has been prepared as well as a table indicating the PI scores and a summary of recommendations for action for each culvert.« less

Regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in murine epidermis. Modulation of enzyme content and activation state by barrier requirements.

PubMed Central

Proksch, E; Elias, P M; Feingold, K R

1990-01-01

Epidermal cholesterol biosynthesis is regulated by barrier function. We quantitated the amount and activation state (phosphorylation-dephosphorylation) of the rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, in epidermis before and after barrier disruption. In murine epidermis we found high enzyme activity (1.75 +/- 0.02 nmol/min per mg protein). After acute barrier disruption, enzyme activity began to increase after 1.5 h, reaching a maximum increase by 2.5 h, and returned to normal by 15 h. Chronic barrier disruption increased total enzyme activity by 83%. In normal epidermis, measurement of HMG CoA reductase activity in microsomes isolated in NaF- vs. NaCl-containing buffers demonstrated that 46 +/- 2% of the enzyme was in the active form. After acute or chronic barrier disruption, a marked increase in the percentage of HMG CoA reductase in the active form was observed. Acute disruption increased enzyme activation state as early as 15 min, reaching a maximum after 2.5 h, with an increase still present at 15 h, indicating that changes in activation state had a close temporal relationship with barrier function. Increases in total HMG CoA reductase activity occurred only after profound barrier disruption, whereas changes in activation state occur with lesser degrees of barrier disruption. Artificial correction of barrier function prevented the increase in total HMG CoA reductase activity, and partially prevented the increase in enzyme activation. These results show that barrier requirements regulate epidermal cholesterol synthesis by modulating both the HMG CoA reductase amount and activation state. Images PMID:2312730

Cultural Barriers to Change in Assessment Practices in Higher Education

ERIC Educational Resources Information Center

Jenkins, Deborah Bainer

2007-01-01

The culture at the authors' institution raised barriers to changing from traditional assessment to portfolio assessment in the doctoral program. A Culture of Independence presented barriers of time and functional inadequacy. A Culture of Compliance raised trust, group process, and membership issues. These barriers were managed and overcome using…

Factors influencing speech and language outcomes of children with early identified severe/profound hearing loss: Clinician-identified facilitators and barriers.

PubMed

Fulcher, Anne Nivelles; Purcell, Alison; Baker, Elise; Munro, Natalie

2015-06-01

Early identification of severe/profound childhood hearing loss (HL) gives these children access to hearing devices and early intervention to facilitate improved speech and language outcomes. Predicting which infants will go on to achieve such outcomes remains difficult. This study describes clinician identified malleable and non-malleable factors that may influence speech and language outcomes for children with severe/profound HL. Semi-structured interviews were conducted with six experienced auditory verbal clinicians. A collective case study design was implemented. The interviews were transcribed and coded into themes using constant comparative analysis. Clinicians identified that, for children with severe/profound HL, early identification, early amplification and commencing auditory-verbal intervention under 6 months of age may facilitate child progress. Possible barriers were living in rural/remote areas, the clinicians' lack of experience and confidence in providing intervention for infants under age 6-months and belonging to a family with a culturally and linguistically diverse (CALD) background. The results indicate that multiple factors need to be considered by clinicians working with children with HL and their families to determine how each child functions within their own environment and personal contexts, consistent with the International Classification of Functioning, Disability and Health (ICF) framework. Such an approach is likely to empower clinicians to carefully balance potential barriers to, and facilitators of, optimal speech and language outcomes for all children with HL.

Impaired Intestinal Mucosal Barrier upon Ischemia-Reperfusion: “Patching Holes in the Shield with a Simple Surgical Method”

PubMed Central

Rosero, Olivér; Ónody, Péter; Molnár, Dávid; Lotz, Gábor; Turóczi, Zsolt; Fülöp, András; Garbaisz, Dávid; Harsányi, László; Szijártó, Attila

2014-01-01

Mesenteric ischemia-reperfusion (IR) is associated with impairment of the gut barrier function and the initiation of a proinflammatory cascade with life-threatening results. Therefore methods directed to ameliorate IR injury are of great importance. We aimed at describing the effects of postconditioning (PC) on the alterations of the intestinal mucosal function and the inflammatory response upon mesenteric IR. Methods. Male Wistar rats were gavaged with green fluorescent protein-expressing E. coli suspensions. Animals were randomized into three groups (n = 15), sham-operated, IR-, and PC-groups, and underwent 60 minutes of superior mesenteric artery occlusion, followed by 6 hours of reperfusion. Postconditioning was performed at the onset of reperfusion. Blood and tissue samples were taken at the end of reperfusion, for histological, bacteriological, and plasma examinations. Results. The PC-group presented a more favorable claudin-2, claudin-3, claudin-4, and zonula occludens-1 membrane expression profile, and significantly lower rates of bacterial translocation to distant organs and plasma D-lactate levels compared to the IR-group. Histopathological lesions, plasma I-FABP, IL-6, and TNF-α levels were significantly lower in the PC-group compared to the IR-group. Conclusion. The use of postconditioning improved the integrity of the intestinal mucosal barrier upon mesenteric IR, and thus reduced the incidence of bacterial translocation and development of a systemic inflammatory response. PMID:24955347

Decreased Charge Transport Barrier and Recombination of Organic Solar Cells by Constructing Interfacial Nanojunction with Annealing-Free ZnO and Al Layers.

PubMed

Liu, Chunyu; Zhang, Dezhong; Li, Zhiqi; Zhang, Xinyuan; Guo, Wenbin; Zhang, Liu; Ruan, Shengping; Long, Yongbing

2017-07-05

To overcome drawbacks of the electron transport layer, such as complex surface defects and unmatched energy levels, we successfully employed a smart semiconductor-metal interfacial nanojunciton in organic solar cells by evaporating an ultrathin Al interlayer onto annealing-free ZnO electron transport layer, resulting in a high fill factor of 73.68% and power conversion efficiency of 9.81%. The construction of ZnO-Al nanojunction could effectively fill the surface defects of ZnO and reduce its work function because of the electron transfer from Al to ZnO by Fermi level equilibrium. The filling of surface defects decreased the interfacial carrier recombination in midgap trap states. The reduced surface work function of ZnO-Al remodulated the interfacial characteristics between ZnO and [6,6]-phenyl C71-butyric acid methyl ester (PC 71 BM), decreasing or even eliminating the interfacial barrier against the electron transport, which is beneficial to improve the electron extraction capacity. The filled surface defects and reduced interfacial barrier were realistically observed by photoluminescence measurements of ZnO film and the performance of electron injection devices, respectively. This work provides a simple and effective method to simultaneously solve the problems of surface defects and unmatched energy level for the annealing-free ZnO or other metal oxide semiconductors, paving a way for the future popularization in photovoltaic devices.

Impaired intestinal mucosal barrier upon ischemia-reperfusion: "patching holes in the shield with a simple surgical method".

PubMed

Rosero, Olivér; Ónody, Péter; Kovács, Tibor; Molnár, Dávid; Lotz, Gábor; Tóth, Szilárd; Turóczi, Zsolt; Fülöp, András; Garbaisz, Dávid; Harsányi, László; Szijártó, Attila

2014-01-01

Mesenteric ischemia-reperfusion (IR) is associated with impairment of the gut barrier function and the initiation of a proinflammatory cascade with life-threatening results. Therefore methods directed to ameliorate IR injury are of great importance. We aimed at describing the effects of postconditioning (PC) on the alterations of the intestinal mucosal function and the inflammatory response upon mesenteric IR. Male Wistar rats were gavaged with green fluorescent protein-expressing E. coli suspensions. Animals were randomized into three groups (n = 15), sham-operated, IR-, and PC-groups, and underwent 60 minutes of superior mesenteric artery occlusion, followed by 6 hours of reperfusion. Postconditioning was performed at the onset of reperfusion. Blood and tissue samples were taken at the end of reperfusion, for histological, bacteriological, and plasma examinations. The PC-group presented a more favorable claudin-2, claudin-3, claudin-4, and zonula occludens-1 membrane expression profile, and significantly lower rates of bacterial translocation to distant organs and plasma D-lactate levels compared to the IR-group. Histopathological lesions, plasma I-FABP, IL-6, and TNF- α levels were significantly lower in the PC-group compared to the IR-group. The use of postconditioning improved the integrity of the intestinal mucosal barrier upon mesenteric IR, and thus reduced the incidence of bacterial translocation and development of a systemic inflammatory response.

Toward improving mucosal barrier defenses: rhG-CSF plus IgG antibody.

PubMed

Simmonds, Aryeh; LaGamma, Edmund F

2006-11-01

Epithelial cell functions ultimately define the ability of the extremely low birth weight human fetus to survive outside of the uterus. These specialized epithelial cell capacities manage all human interactions with the ex utero world including: (i) lung mechanics, surface chemistry and gas exchange, (ii) renal tubular balance of fluid and electrolytes, (iii) barrier functions of the intestine and skin for keeping bacteria out and water in, plus enabling intestinal digestion, as well as (iv) maintaining an intact neuroepithelium lining of the ventricles of the brain and retina. In Part I of this two part review, the authors describe why the gut barrier is a clinically relevant model system for studying the complex interplay between innate and adaptive immunity, dendritic &epithelial cell interactions, intraepithelial lymphocytes, M-cells, as well as the gut associated lymphoid tissues where colonization after birth, clinician feeding practices, use of antibiotics as well as exposure to prebiotics, probiotics and maternal vaginal flora all program the neonate for a life-time of immune competence distinguishing "self" from foreign antigens. These barrier defense capacities become destructive during disease processes like necrotizing enterocolitis (NEC) when an otherwise maturationally normal, yet dysregulated and immature, immune defense system is associated with high levels of certain inflammatory mediators like TNFa. In Part II the authors discuss the rationale for why rhG-CSF has theoretical advantages in managing NEC or sepsis by augmenting neonatal neutrophil number, neutrophil expression of Fcg and complement receptors, as well as phagocytic function and oxidative burst. rhG-CSF also has potent anti-TNFa functions that may serve to limit extension of tissue destruction while not impairing bacterial killing capacity. Healthy, non-infected neutropenic and septic neonates differ in their ability to respond to rhG-CSF; however, no neonatal clinical trials to date have identified a clear clinical benefit of rhG-CSF therapy. This manuscript will review the literature and evidence available for identifying the ideal subject for cytokine treatment using NEC as the model disease target.

Method for improving the performance of oxidizable ceramic materials in oxidizing environments

NASA Technical Reports Server (NTRS)

Nagaraj, Bangalore A. (Inventor)

2002-01-01

Improved adhesion of thermal barrier coatings to nonmetallic substrates using a dense layer of ceramic on an underlying nonmetallic substrate that includes at least one oxidizable component. The improved adhesion occurs because the application of the dense ceramic layer forms a diffusion barrier for oxygen. This diffusion barrier prevents the oxidizable component of the substrate from decomposing. The present invention applies ceramic by a process that deposits a relatively thick and dense ceramic layer on the underlying substrate. The formation of the dense layer of ceramic avoids the problem of void formation associated with ceramic formation by most prior art thermal decomposition processes. The formation of voids has been associated with premature spalling of thermal barrier layers and other protective layers applied to substrates.

Barrier properties of cultured retinal pigment epithelium.

PubMed

Rizzolo, Lawrence J

2014-09-01

The principal function of an epithelium is to form a dynamic barrier that regulates movement between body compartments. Each epithelium is specialized with barrier functions that are specific for the tissues it serves. The apical surface commonly faces a lumen, but the retinal pigment epithelium (RPE) appears to be unique by a facing solid tissue, the sensory retina. Nonetheless, there exists a thin (subretinal) space that can become fluid filled during pathology. RPE separates the subretinal space from the blood supply of the outer retina, thereby forming the outer blood-retinal barrier. The intricate interaction between the RPE and sensory retina presents challenges for learning how accurately culture models reflect native behavior. The challenge is heightened by findings that detail the variation of RPE barrier proteins both among species and at different stages of the life cycle. Among the striking differences is the expression of claudin family members. Claudins are the tight junction proteins that regulate ion diffusion across the spaces that lie between the cells of a monolayer. Claudin expression by RPE varies with species and life-stage, which implies functional differences among commonly used animal models. Investigators have turned to transcriptomics to supplement functional studies when comparing native and cultured tissue. The most detailed studies of the outer blood-retinal barrier have focused on human RPE with transcriptome and functional studies reported for human fetal, adult, and stem-cell derived RPE. Copyright © 2014 Elsevier Ltd. All rights reserved.

Adverse Event Reporting: Harnessing Residents to Improve Patient Safety.

PubMed

Tevis, Sarah E; Schmocker, Ryan K; Wetterneck, Tosha B

2017-10-13

Reporting of adverse and near miss events are essential to identify system level targets to improve patient safety. Resident physicians historically report few events despite their role as front-line patient care providers. We sought to evaluate barriers to adverse event reporting in an effort to improve reporting. Our main outcomes were as follows: resident attitudes about event reporting and the frequency of event reporting before and after interventions to address reporting barriers. We surveyed first year residents regarding barriers to adverse event reporting and used this input to construct a fishbone diagram listing barriers to reporting. Barriers were addressed, and resident event reporting was compared before and after efforts were made to reduce obstacles to reporting. First year residents (97%) recognized the importance of submitting event reports; however, the majority (85%) had not submitted an event report in the first 6 months of residency. Only 7% of residents specified that they had not witnessed an adverse event in 6 months, whereas one third had witnessed 10 or more events. The main barriers were as follows: lack of knowledge about how to submit events (38%) and lack of time to submit reports (35%). After improving resident education around event reporting and simplifying the reporting process, resident event reporting increased 230% (68 to 154 annual reports, P = 0.025). We were able to significantly increase resident event reporting by educating residents about adverse events and near misses and addressing the primary barriers to event reporting. Moving forward, we will continue annual resident education about patient safety, focus on improving feedback to residents who submit reports, and empower senior residents to act as role models to junior residents in patient safety initiatives.

Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming

2005-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and requirements will be discussed. An experimental approach is established to monitor in real time the thermal conductivity of the coating systems subjected to high-heat-flux, steady-state and cyclic temperature gradients. Advanced low conductivity thermal barrier coatings have also been developed using a multi-component defect clustering approach, and shown to have improved thermal stability. The durability and erosion resistance of low conductivity thermal barrier coatings have been improved utilizing advanced coating architecture design, composition optimization, in conjunction with more sophisticated modeling and design tools.

Stabilization of glycemic control and improved quality of life using a shared medical appointment model in adolescents with type 1 diabetes in suboptimal control.

PubMed

Floyd, Baraka D; Block, Jennifer M; Buckingham, Bruce B; Ly, Trang; Foster, Nicole; Wright, Robert; Mueller, Claudia L; Hood, Korey K; Shah, Avni C

2017-05-01

Declining glycemic control in type 1 diabetes (T1D) during adolescence persists despite treatment advances. Non-adherence, peer relations, diabetes burnout, risk taking, transition to autonomy, family conflict, and poor quality of life (QOL) are recognized barriers. Shared medical appointments (SMAs) in adolescent T1D may offer benefits, but data are limited. Our objective was to determine whether SMAs, with multi-component interventions utilizing multidisciplinary teams, improve glycemic control and psychosocial outcomes in poorly controlled adolescent T1D. SMAs focused on self-management, communication skills, goal setting, glucose pattern recognition, and peer/diabetes team support. SMAs included: individual history and physical, labs, surveys, multidisciplinary educational ice breakers, group session, and individual wrap up. Outcomes were QOL, adherence, and retrospective and prospective glycemic control. Three to six subjects and families came to 3 SMAs and 1 individual appointment every 3 months over 9 months. A total of 37 English speaking subjects, ages 12-16 yrs, with T1D ≥ 1 year, and hemoglobin A1c (HbA1c) 7.5-11% enrolled. Thirty-two subjects attended 75% of visits, meeting inclusion criteria. HbA1c worsened in the 9 months before study (ΔHbA1c= 0.7 ± 1.2; p < 0.01), but remained stable during study (ΔHbA1c = 0.01 ± 1.2; p > 0.05). There were significant improvements in overall QOL (p = 0.005), school function (p = 0.006), psychosocial function (p = 0.008), barriers (p = 0.02), adherence (p = 0.01), and communication (p = 0.02). Improvements in school function and communication reached clinical significance. SMAs are feasible replacements to individual appointments in adolescent T1D, stabilizing glycemic control and improving QOL. Randomized controlled trials with optimizations are needed to further explore and refine this intervention. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Barriers to Specialty Care and Specialty Referral Completion in the Community Health Center Setting

PubMed Central

Zuckerman, Katharine E.; Perrin, James M.; Hobrecker, Karin; Donelan, Karen

2013-01-01

Objective To assess the frequency of barriers to specialty care and to assess which barriers are associated with an incomplete specialty referral (not attending a specialty visit when referred by a primary care provider) among children seen in community health centers. Study design Two months after their child’s specialty referral, 341 parents completed telephone surveys assessing whether a specialty visit was completed and whether they experienced any of 10 barriers to care. Family/community barriers included difficulty leaving work, obtaining childcare, obtaining transportation, and inadequate insurance. Health care system barriers included getting appointments quickly, understanding doctors and nurses, communicating with doctors’ offices, locating offices, accessing interpreters, and inconvenient office hours. We calculated barrier frequency and total barriers experienced. Using logistic regression, we assessed which barriers were associated with incomplete referral, and whether experiencing ≥4 barriers was associated with incomplete referral. Results A total of 22.9% of families experienced incomplete referral. 42.0% of families encountered 1 or more barriers. The most frequent barriers were difficulty leaving work, obtaining childcare, and obtaining transportation. On multivariate analysis, difficulty getting appointments quickly, difficulty finding doctors’ offices, and inconvenient office hours were associated with incomplete referral. Families experiencing ≥4 barriers were more likely than those experiencing ≤3 barriers to have incomplete referral. Conclusion Barriers to specialty care were common and associated with incomplete referral. Families experiencing many barriers had greater risk of incomplete referral. Improving family/community factors may increase satisfaction with specialty care; however, improving health system factors may be the best way to reduce incomplete referrals. PMID:22929162

Barriers for identification and treatment of problem drinkers in primary care.

PubMed

Coloma-Carmona, Ainhoa; Carballo, José Luis; Tirado-González, Sonia

Due to the lack of studies in the Spanish population, this study aims to analyze the barriers perceived by health professionals from different Spanish health centers when attempting to identify and treat problem drinkers and the importance given to this aspect, as well as analyzing the possible differences as a function of the professionals' health teams. We also analyze the psychometric properties of the questionnaire used to assess these barriers. The participants included 107 health professionals: 62.7% belonged to the medical team and 32.4% to the nursing team. After we had reviewed previous studies, collecting the main barriers referred to in them, participants completed an ad hoc questionnaire. The main barriers found were the belief that patients will lie about their actual consumption and will not identify its negative consequences, and the belief that they will reject participating in an intervention for their alcohol consumption. No significant differences between doctors and nurses were found in any of the barriers assessed. The results provide empirical evidence of the reliability of the test for the assessment by both teams of professionals. Studies are needed to examine in greater depth these conclusions, extending the number of variables studied to determine a more complete profile of the health professionals who are reluctant to incorporate the assessment and treatment of problem drinkers in their consultation. This could help to improve the design of programs to facilitate and encourage its implementation in primary care. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Zur Funktion von Weiterbildung fur Frauen in den neuen Landern im Kontext des Transformationsprozesses (On the Function of Further Education for Women in the New Laender in the Context of the Process of Transformation).

ERIC Educational Resources Information Center

Schiersmann, Christiane; Ambos, Ingrid

1996-01-01

Focuses on motives leading women in the new German Laender to participate in further education and on gender-related barriers to further education. Shows that women accept the need for further education, hoping to improve their job situation but knowing that their efforts will have a limited effect on employment chances. (DSK)

Medical Logistics Functional Integration Management To-Be Modeling Workshop: Improving Today For a Better Tomorrow

DTIC Science & Technology

1993-06-18

A unique identifying number assigned by the contracting officer that is a binding agreement between the Government and a Vendor. quantity- of -beds The...repair it; maintenance contracts may be costly. Barriers to Implementation • Requires the large amount of funding to link a significant number of ...and follow-on requirements for maintenance, training, and installation. 22. Cross Sharing of Standard Contract Shells A3 2.88 Al112 Local activities

Improving Collaboration between Public Health and Family Health Teams in Ontario

PubMed Central

Green, Michael E.; Weir, Erica; Hogg, William; Etches, Vera; Moore, Kieran; Hunter, Duncan; Birtwhistle, Richard

2013-01-01

Objectives: To identify and explore areas where responsibilities may overlap between family health teams (FHTs) and public health units (PHUs); to identify facilitators or barriers to collaboration; and to identify priority areas for increased collaboration. Design and context: Cross-sectional mixed-methods study of FHTs and PHUs in Ontario, Canada, consisting of a postal survey, key informant interviews and a roundtable meeting. Results: The survey response rate was 46%. Direct client-based services such as giving immunizations, promoting prenatal health and nutrition, and counselling related to smoking cessation were identified as the top three areas of perceived overlap. The greatest interest in collaboration was expressed in the areas of emergency planning and preparedness, immunization, and prenatal health and nutrition. Good communication with a clear understanding of roles and functions was the most important facilitator, and lack of resources and absence of a clear provincial mandate and direction to collaborate were identified as significant barriers. Conclusions: Small, simple client-based projects of interest to both kinds of organization would be the best way to move forward in the short term. Improving communication between FHTs and PHUs, understanding of roles and functions, the use of shared or interoperable information systems and greater clarity from government on the ways in which these two key sectors of the healthcare system are intended to work together were identified as important for the success of increased collaboration. PMID:23968630

Heparin-binding EGF-like growth factor and enteric neural stem cell transplantation in the prevention of experimental necrotizing enterocolitis in mice.

PubMed

Wei, Jia; Zhou, Yu; Besner, Gail E

2015-07-01

Necrotizing enterocolitis (NEC) is associated with loss of neurons and glial cells in the enteric nervous system (ENS). Our goal was to determine whether enteric neural stem cell (NSC) transplantation, in conjunction with heparin-binding epidermal growth factor-like growth factor (HB-EGF), could protect against experimental NEC. In vitro, HB-EGF on NSC proliferation and migration, and the effects of receptors utilized by HB-EGF to exert these effects, were determined. In vivo, mouse pups were exposed to experimental NEC and treated with NSC alone, HB-EGF alone, NSC+HB-EGF, or HB-EGF overexpressing NSC. NSC engraftment and differentiation into neurons in the ENS, intestinal injury, intestinal permeability, and intestinal motility were determined. HB-EGF promoted NSC proliferation via ErbB-1 receptors and enhanced NSC migration via ErbB-1, ErbB-4, and Nardilysin receptors. HB-EGF significantly enhanced the engraftment of transplanted NSC into the ENS during NEC. NSC transplantation significantly reduced NEC incidence and improved gut barrier function and intestinal motility, and these effects were augmented by simultaneous administration of HB-EGF or by transplantation of HB-EGF overexpressing NSC. HB-EGF promotes NSC proliferation and migration. HB-EGF and NSC reduce intestinal injury and improve gut barrier function and intestinal motility in experimental NEC. Combined HB-EGF and NSC transplantation may represent a potential future therapy to prevent NEC.

Theoretical Investigations of the Electrochemical Reduction of CO on Single Metal Atoms Embedded in Graphene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirk, Charlotte; Chen, Leanne D.; Siahrostami, Samira

Single transition metal atoms embedded at single vacancies of graphene provide a unique paradigm for catalytic reactions. We present a density functional theory study of such systems for the electrochemical reduction of CO. Theoretical investigations of CO electrochemical reduction are particularly challenging in that electrochemical activation energies are a necessary descriptor of activity. We determined the electrochemical barriers for key proton–electron transfer steps using a state-of-the-art, fully explicit solvent model of the electrochemical interface. The accuracy of GGA-level functionals in describing these systems was also benchmarked against hybrid methods. We find the first proton transfer to form CHO from COmore » to be a critical step in C 1 product formation. On these single atom sites, the corresponding barrier scales more favorably with the CO binding energy than for 211 and 111 transition metal surfaces, in the direction of improved activity. Intermediates and transition states for the hydrogen evolution reaction were found to be less stable than those on transition metals, suggesting a higher selectivity for CO reduction. We present a rate volcano for the production of methane from CO. We identify promising candidates with high activity, stability, and selectivity for the reduction of CO. As a result, this work highlights the potential of these systems as improved electrocatalysts over pure transition metals for CO reduction.« less

Theoretical Investigations of the Electrochemical Reduction of CO on Single Metal Atoms Embedded in Graphene

DOE PAGES

Kirk, Charlotte; Chen, Leanne D.; Siahrostami, Samira; ...

2017-12-18

Single transition metal atoms embedded at single vacancies of graphene provide a unique paradigm for catalytic reactions. We present a density functional theory study of such systems for the electrochemical reduction of CO. Theoretical investigations of CO electrochemical reduction are particularly challenging in that electrochemical activation energies are a necessary descriptor of activity. We determined the electrochemical barriers for key proton–electron transfer steps using a state-of-the-art, fully explicit solvent model of the electrochemical interface. The accuracy of GGA-level functionals in describing these systems was also benchmarked against hybrid methods. We find the first proton transfer to form CHO from COmore » to be a critical step in C 1 product formation. On these single atom sites, the corresponding barrier scales more favorably with the CO binding energy than for 211 and 111 transition metal surfaces, in the direction of improved activity. Intermediates and transition states for the hydrogen evolution reaction were found to be less stable than those on transition metals, suggesting a higher selectivity for CO reduction. We present a rate volcano for the production of methane from CO. We identify promising candidates with high activity, stability, and selectivity for the reduction of CO. As a result, this work highlights the potential of these systems as improved electrocatalysts over pure transition metals for CO reduction.« less

A Key Claudin Extracellular Loop Domain is Critical for Epithelial Barrier Integrity

PubMed Central

Mrsny, Randall J.; Brown, G. Thomas; Gerner-Smidt, Kirsten; Buret, Andre G.; Meddings, Jon B.; Quan, Clifford; Koval, Michael; Nusrat, Asma

2008-01-01

Intercellular tight junctions (TJs) regulate epithelial barrier properties. Claudins are major structural constituents of TJs and belong to a large family of tetra-spanning membrane proteins that have two predicted extracellular loops (ELs). Given that claudin-1 is widely expressed in epithelia, we further defined the role of its EL domains in determining TJ function. The effects of several claudin-1 EL mimetic peptides on epithelial barrier structure and function were examined. Incubation of model human intestinal epithelial cells with a 27-amino acid peptide corresponding to a portion of the first EL domain (Cldn-153–80) reversibly interfered with epithelial barrier function by inducing the rearrangement of key TJ proteins: occludin, claudin-1, junctional adhesion molecule-A, and zonula occludens-1. Cldn-153–80 associated with both claudin-1 and occludin, suggesting both the direct interference with the ability of these proteins to assemble into functional TJs and their close interaction under physiological conditions. These effects were specific for Cldn-153–80, because peptides corresponding to other claudin-1 EL domains failed to influence TJ function. Furthermore, the oral administration of Cldn-153–80 to rats increased paracellular gastric permeability. Thus, the identification of a critical claudin-1 EL motif, Cldn-153–80, capable of regulating TJ structure and function, offers a useful adjunct to treatments that require drug delivery across an epithelial barrier. PMID:18349130

Defenders and Challengers of Endothelial Barrier Function

PubMed Central

Rahimi, Nader

2017-01-01

Regulated vascular permeability is an essential feature of normal physiology and its dysfunction is associated with major human diseases ranging from cancer to inflammation and ischemic heart diseases. Integrity of endothelial cells also play a prominent role in the outcome of surgical procedures and organ transplant. Endothelial barrier function and integrity are regulated by a plethora of highly specialized transmembrane receptors, including claudin family proteins, occludin, junctional adhesion molecules (JAMs), vascular endothelial (VE)-cadherin, and the newly identified immunoglobulin (Ig) and proline-rich receptor-1 (IGPR-1) through various distinct mechanisms and signaling. On the other hand, vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2, play a central role in the destabilization of endothelial barrier function. While claudins and occludin regulate cell–cell junction via recruitment of zonula occludens (ZO), cadherins via catenin proteins, and JAMs via ZO and afadin, IGPR-1 recruits bullous pemphigoid antigen 1 [also called dystonin (DST) and SH3 protein interacting with Nck90/WISH (SH3 protein interacting with Nck)]. Endothelial barrier function is moderated by the function of transmembrane receptors and signaling events that act to defend or destabilize it. Here, I highlight recent advances that have provided new insights into endothelial barrier function and mechanisms involved. Further investigation of these mechanisms could lead to the discovery of novel therapeutic targets for human diseases associated with endothelial dysfunction. PMID:29326721

Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.

PubMed

Liévin-Le Moal, Vanessa

2013-06-01

Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. © 2013 John Wiley & Sons Ltd.

Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

NASA Technical Reports Server (NTRS)

Nainiger, J. J.

1978-01-01

An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

Fecal microbiota transplantation prevents hepatic encephalopathy in rats with carbon tetrachloride-induced acute hepatic dysfunction.

PubMed

Wang, Wei-Wei; Zhang, Yu; Huang, Xiao-Bing; You, Nan; Zheng, Lu; Li, Jing

2017-10-14

To investigate whether fecal microbiota transplantation (FMT) prevents hepatic encephalopathy (HE) in rats with carbon tetrachloride (CCl 4 )-induced acute hepatic dysfunction. A rat model of HE was established with CCl 4 . Rat behaviors and spatial learning capability were observed, and hepatic necrosis, intestinal mucosal barrier, serum ammonia levels and intestinal permeability were determined in HE rats receiving FMT treatment. Furthermore, the expression of tight junction proteins (Claudin-1, Claudin-6 and Occludin), Toll-like receptor (TLR) 4/TLR9, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α was examined. FMT improved rat behaviors, HE grade and spatial learning capability. Moreover, FMT prevented hepatic necrosis and intestinal mucosal barrier damage, leading to hepatic clearance of serum ammonia levels and reduced intestinal permeability. The expression of TLR4 and TLR9, two potent mediators of inflammatory response, was significantly downregulated in the liver of rats treated with FMT. Consistently, circulating pro-inflammatory factors such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α were remarkably decreased, indicating that FMT is able to limit systemic inflammation by decreasing the expression of TLR4 and TLR9. Importantly, HE-induced loss of tight junction proteins (Claudin-1, Claudin-6 and Occludin) was restored in intestinal tissues of rats receiving FMT treatment. FMT enables protective effects in HE rats, and it improves the cognitive function and reduces the liver function indexes. FMT may cure HE by altering the intestinal permeability and improving the TLR response of the liver.

Targeting VEGF-B as a novel treatment for insulin resistance and type 2 diabetes.

PubMed

Hagberg, Carolina E; Mehlem, Annika; Falkevall, Annelie; Muhl, Lars; Fam, Barbara C; Ortsäter, Henrik; Scotney, Pierre; Nyqvist, Daniel; Samén, Erik; Lu, Li; Stone-Elander, Sharon; Proietto, Joseph; Andrikopoulos, Sofianos; Sjöholm, Ake; Nash, Andrew; Eriksson, Ulf

2012-10-18

The prevalence of type 2 diabetes is rapidly increasing, with severe socioeconomic impacts. Excess lipid deposition in peripheral tissues impairs insulin sensitivity and glucose uptake, and has been proposed to contribute to the pathology of type 2 diabetes. However, few treatment options exist that directly target ectopic lipid accumulation. Recently it was found that vascular endothelial growth factor B (VEGF-B) controls endothelial uptake and transport of fatty acids in heart and skeletal muscle. Here we show that decreased VEGF-B signalling in rodent models of type 2 diabetes restores insulin sensitivity and improves glucose tolerance. Genetic deletion of Vegfb in diabetic db/db mice prevented ectopic lipid deposition, increased muscle glucose uptake and maintained normoglycaemia. Pharmacological inhibition of VEGF-B signalling by antibody administration to db/db mice enhanced glucose tolerance, preserved pancreatic islet architecture, improved β-cell function and ameliorated dyslipidaemia, key elements of type 2 diabetes and the metabolic syndrome. The potential use of VEGF-B neutralization in type 2 diabetes was further elucidated in rats fed a high-fat diet, in which it normalized insulin sensitivity and increased glucose uptake in skeletal muscle and heart. Our results demonstrate that the vascular endothelium can function as an efficient barrier to excess muscle lipid uptake even under conditions of severe obesity and type 2 diabetes, and that this barrier can be maintained by inhibition of VEGF-B signalling. We propose VEGF-B antagonism as a novel pharmacological approach for type 2 diabetes, targeting the lipid-transport properties of the endothelium to improve muscle insulin sensitivity and glucose disposal.

[Barriers and facilitators to health care coordination in two integrated health care organizations in Catalonia (Spain)].

PubMed

Vargas Lorenzo, Ingrid; Vázquez Navarrete, M Luisa

2007-01-01

To analyze 2 integrated delivery systems (IDS) in Catalonia and identify areas for future development to improve their effectiveness. An exploratory, descriptive, qualitative study was carried out based on case studies by means of document analysis and semi-structured individual interviews. A criterion sample of cases and, for each case, of documents and informants was selected. Study cases consisted of the Consorci Sanitari del Maresme (CSdM) and the Consorci Sanitari de Terrassa/Fundació Hospital Sant Llàtzer (FHSLL). A total of 127 documents were analyzed and 29 informants were interviewed: IDS managers (n = 10), technical staff (n = 5), operational unit managers (n = 5) and health professionals (n = 9). Content analysis was conducted, with mixed generation of categories and segmentation by cases and subjects. CSdM and CSdT/FHSLL are health care organizations with backward vertical integration, total services production, and real (CSdM) and virtual (CSdT/FHSLL) ownership. Funds are allocated by care level. The governing body is centralized in CSdM and decentralized in CSdT/FHSLL. In both organizations, the global objectives are oriented toward improving coordination and efficiency but are not in line with those of the operational units. Both organizations present a functional structure with integration of support functions and utilize mechanisms for collaboration between care levels based on work processes standardization. Both IDS present facilitators and barriers to health care coordination. To improve coordination, changes in external elements (payment mechanism) and in internal elements (governing body role, organizational structure and coordination mechanisms) are required.

Gut barrier in health and disease: focus on childhood.

PubMed

Viggiano, D; Ianiro, G; Vanella, G; Bibbò, S; Bruno, G; Simeone, G; Mele, G

2015-01-01

The gut barrier is a functional unit, organized as a multi-layer system, made up of two main components: a physical barrier surface, which prevents bacterial adhesion and regulates paracellular diffusion to the host tissues, and a deep functional barrier, that is able to discriminate between pathogens and commensal microorganisms, organizing the immune tolerance and the immune response to pathogens. Other mechanisms, such as gastric juice and pancreatic enzymes (which both have antibacterial properties) participate in the luminal integrity of the gut barrier. From the outer layer to the inner layer, the physical barrier is composed of gut microbiota (that competes with pathogens to gain space and energy resources, processes the molecules necessary to mucosal integrity and modulates the immunological activity of deep barrier), mucus (which separates the intraluminal content from more internal layers and contains antimicrobial products and secretory IgA), epithelial cells (which form a physical and immunological barrier) and the innate and adaptive immune cells forming the gut-associated lymphoid tissue (which is responsible for antigen sampling and immune responses). Disruption of the gut barrier has been associated with many gastrointestinal diseases, but also with extra-intestinal pathological condition, such as type 1 diabetes mellitus, allergic diseases or autism spectrum disorders. The maintenance of a healthy intestinal barrier is therefore of paramount importance in children, for both health and economic reasons. Many drugs or compounds used in the treatment of gastrointestinal disorders act through the restoration of a normal intestinal permeability. Several studies have highlighted the role of probiotics in the modulation and reduction of intestinal permeability, considering the strong influence of gut microbiota in the modulation of the function and structure of gut barrier, but also on the immune response of the host. To date, available weapons for the maintenance and repair of gut barrier are however few, even if promising. Considerable efforts, including both a better understanding of the gut barrier features and mechanisms in health and disease, and the development of new pharmacological approaches for the modulation of gut barrier components, are needed for the prevention and treatment of gastrointestinal and extraintestinal diseases associated with gut barrier impairment.

Neuroglian, Gliotactin, and the Na+/K+ ATPase are essential for septate junction function in Drosophila

PubMed Central

Genova, Jennifer L.; Fehon, Richard G.

2003-01-01

One essential function of epithelia is to form a barrier between the apical and basolateral surfaces of the epithelium. In vertebrate epithelia, the tight junction is the primary barrier to paracellular flow across epithelia, whereas in invertebrate epithelia, the septate junction (SJ) provides this function. In this study, we identify new proteins that are required for a functional paracellular barrier in Drosophila. In addition to the previously known components Coracle (COR) and Neurexin (NRX), we show that four other proteins, Gliotactin, Neuroglian (NRG), and both the α and β subunits of the Na+/K+ ATPase, are required for formation of the paracellular barrier. In contrast to previous reports, we demonstrate that the Na pump is not localized basolaterally in epithelial cells, but instead is concentrated at the SJ. Data from immunoprecipitation and somatic mosaic studies suggest that COR, NRX, NRG, and the Na+/K+ ATPase form an interdependent complex. Furthermore, the observation that NRG, a Drosophila homologue of vertebrate neurofascin, is an SJ component is consistent with the notion that the invertebrate SJ is homologous to the vertebrate paranodal SJ. These findings have implications not only for invertebrate epithelia and barrier functions, but also for understanding of neuron–glial interactions in the mammalian nervous system. PMID:12782686

Neuroglian, Gliotactin, and the Na+/K+ ATPase are essential for septate junction function in Drosophila.

PubMed

Genova, Jennifer L; Fehon, Richard G

2003-06-09

One essential function of epithelia is to form a barrier between the apical and basolateral surfaces of the epithelium. In vertebrate epithelia, the tight junction is the primary barrier to paracellular flow across epithelia, whereas in invertebrate epithelia, the septate junction (SJ) provides this function. In this study, we identify new proteins that are required for a functional paracellular barrier in Drosophila. In addition to the previously known components Coracle (COR) and Neurexin (NRX), we show that four other proteins, Gliotactin, Neuroglian (NRG), and both the alpha and beta subunits of the Na+/K+ ATPase, are required for formation of the paracellular barrier. In contrast to previous reports, we demonstrate that the Na pump is not localized basolaterally in epithelial cells, but instead is concentrated at the SJ. Data from immunoprecipitation and somatic mosaic studies suggest that COR, NRX, NRG, and the Na+/K+ ATPase form an interdependent complex. Furthermore, the observation that NRG, a Drosophila homologue of vertebrate neurofascin, is an SJ component is consistent with the notion that the invertebrate SJ is homologous to the vertebrate paranodal SJ. These findings have implications not only for invertebrate epithelia and barrier functions, but also for understanding of neuron-glial interactions in the mammalian nervous system.

Perceived Benefits and Barriers of a Community-Based Diabetes Prevention and Management Program.

PubMed

Shawley-Brzoska, Samantha; Misra, Ranjita

2018-03-13

This study examined the perceptions of benefits of and barriers to participating in a community-based diabetes program to improve program effectiveness. The Diabetes Prevention and Management (DPM) program was a twenty-two session, 1-year program, modeled after the evidence-based National Diabetes Prevention Program and AADE7 Self-Care Behaviors framework. Community-based participatory research approach was used to culturally tailor the curriculum. Participants included overweight or obese adults with dysglycemia. A benefits and barriers survey was developed to gather information on participants' perception of the program, as well as information on demographics and health literacy levels. Eighty-nine adults participated in the DPM program (73% females; 62% diabetic; 77% had adequate health literacy); 79% of participants completed the benefits and barriers survey. Principal component analysis indicated two components representing benefits (Cronbach's α = 0.83) and barriers (α = 0.65). The majority perceived high benefits and low barriers to program participation; benefits included helpful interaction with health coach or program leader (73%), improved lifestyle modification (65%) due to the program, and satisfaction with the program (75%). Open-ended questions confirmed themes related to benefits of program participation, suggestion for programmatic improvements as well as barriers to participation. Participant feedback could be used to guide interventions and tailor future program implementation.

Perceived Benefits and Barriers of a Community-Based Diabetes Prevention and Management Program

PubMed Central

Shawley-Brzoska, Samantha; Misra, Ranjita

2018-01-01

This study examined the perceptions of benefits of and barriers to participating in a community-based diabetes program to improve program effectiveness. The Diabetes Prevention and Management (DPM) program was a twenty-two session, 1-year program, modeled after the evidence-based National Diabetes Prevention Program and AADE7 Self-Care Behaviors framework. Community-based participatory research approach was used to culturally tailor the curriculum. Participants included overweight or obese adults with dysglycemia. A benefits and barriers survey was developed to gather information on participants’ perception of the program, as well as information on demographics and health literacy levels. Eighty-nine adults participated in the DPM program (73% females; 62% diabetic; 77% had adequate health literacy); 79% of participants completed the benefits and barriers survey. Principal component analysis indicated two components representing benefits (Cronbach’s α = 0.83) and barriers (α = 0.65). The majority perceived high benefits and low barriers to program participation; benefits included helpful interaction with health coach or program leader (73%), improved lifestyle modification (65%) due to the program, and satisfaction with the program (75%). Open-ended questions confirmed themes related to benefits of program participation, suggestion for programmatic improvements as well as barriers to participation. Participant feedback could be used to guide interventions and tailor future program implementation. PMID:29534005

Physical activity and physical function changes in obese individuals after gastric bypass surgery.

PubMed

Josbeno, Deborah A; Jakicic, John M; Hergenroeder, Andrea; Eid, George M

2010-01-01

Little is known about the effects of gastric bypass surgery (GBS) on physical activity and physical function. We examined the physical activity, physical function, psychosocial correlates to physical activity participation, and health-related quality of life of patients before and after GBS. A total of 20 patients were assessed before and 3 months after GBS. Physical activity was assessed using the 7-day physical activity recall questionnaire and a pedometer worn for 7 days. Physical function was assessed using the 6-minute walk test, Short Physical Performance Battery, and the physical function subscale of the Medical Outcomes Short Form-36 (SF-36). The Physical Activity Self-Efficacy questionnaire, the Physical Activity Barriers and Outcome Expectations questionnaire, the SF-36, and the Numeric Pain Rating Scale were also administered. Physical activity did not significantly increase from before (191.1 +/- 228.23 min/wk) to after (231.7 +/- 230.04 min/wk) GBS (n = 18); however, the average daily steps did significantly increase (from 4621 +/- 3701 to 7370 +/- 4240 steps/d; n = 11). The scores for the 6-minute walk test (393 +/- 62.08 m to 446 +/- 41.39 m; n = 17), Short Physical Performance Battery (11.2 +/- 1.22 to 11.7 +/- .57; n = 18), physical function subscale of the SF-36 (65 +/- 18.5 to 84.1 +/- 19.9), and the total SF-36 (38.2 +/- 23.58 to 89.7 +/- 15.5; n = 17) increased significantly. The Numeric Pain Rating Scale score decreased significantly for low back (3.5 +/- 1.8 to 1.7 +/- 2.63), knee (2.4 +/- 2.51 to 1.0 +/- 1.43), and foot/ankle (2.3 +/- 2.8 to 0.9 +/- 2.05) pain. No significant changes were found in the Physical Activity Self-Efficacy questionnaire or the Physical Activity Barriers and Outcome Expectations questionnaire. GBS improves physical function, health-related quality of life, and self-reported pain and results in a modest improvement in physical activity. These are important clinical benefits of surgical weight loss. Long-term follow-up is needed to quantify the ability to sustain or further improve these important clinical outcomes. Copyright 2010 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Administrative Barriers to Improving Undergraduate Education. Accent on Improving College Teaching and Learning, 6.

ERIC Educational Resources Information Center

Genthon, Michele; Joscelyn, Mary K., Ed.

Chief academic officers at 1,053 institutions of higher education across the United States were surveyed about the barriers to improving teaching and learning. Using factor analysis, responses were reduced to nine general problem areas. In order of importance from most important to least important, the problems identified were: financial support,…

Using FLIM in the study of permeability barrier function of aged and young skin

NASA Astrophysics Data System (ADS)

Xu, P.; Choi, E. H.; Man, M. Q.; Crumrine, D.; Mauro, T.; Elias, P.

2006-02-01

Aged skin commonly is afflicted by inflammatory skin diseases or xerosis/eczema that can be triggered or exacerbated by impaired epidermal permeability barrier homeostasis. It has been previously described a permeability barrier defect in humans of advanced age (> 75 years), which in a murine analog >18 mos, could be attributed to reduced lipid synthesis synthesis. However, the functional abnormality in moderately aged mice is due not to decreased lipid synthesis, but rather to a specific defect in stratum corneum (SC) acidification causing impaired lipid processing processing. Endogenous Na +/H + antiporter (NHE1) level was found declined in moderately aged mouse epidermis. This acidification defect leads to perturbed permeability barrier homeostasis through more than one pathways, we addressed suboptimal activation of the essential, lipid-processing enzyme, β-glucocerebrosidase (BGC) is linked to elevated SC pH. Finally, the importance of the epidermis acidity is shown by the normalization of barrier function after exogenous acidification of moderately aged skin.

Lychee (Litchi chinensis Sonn.) Pulp Phenolic Extract Provides Protection against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Intestinal Barrier Dysfunction, and Liver Inflammation.

PubMed

Xiao, Juan; Zhang, Ruifen; Zhou, Qiuyun; Liu, Lei; Huang, Fei; Deng, Yuanyuan; Ma, Yongxuan; Wei, Zhencheng; Tang, Xiaojun; Zhang, Mingwei

2017-11-08

Liver injury is the most common consequence of alcohol abuse, which is promoted by the inflammatory response triggered by gut-derived endotoxins produced as a consequence of intestinal microbiota dysbiosis and barrier dysfunction. The aim of this study was to investigate whether modulation of intestinal microbiota and barrier function, and liver inflammation contributes to the hepatoprotective effect of lychee pulp phenolic extract (LPPE) in alcohol-fed mice. Mice were treated with an ethanol-containing liquid diet alone or in combination with LPPE for 8 weeks. LPPE supplementation alleviated ethanol-induced liver injury and downregulated key markers of inflammation. Moreover, LPPE supplementation reversed the ethanol-induced alteration of intestinal microbiota composition and increased the expression of intestinal tight junction proteins, mucus protecting proteins, and antimicrobial proteins. Furthermore, in addition to decreasing serum endotoxin level, LPPE supplementation suppressed CD14 and toll-like receptor 4 expression, and repressed the activation of nuclear factor-κB p65 in the liver. These data suggest that intestinal microbiota dysbiosis, intestinal barrier dysfunction, and liver inflammation are improved by LPPE, and therefore, the intake of LPPE or Litchi pulp may be an effective strategy to alleviate the susceptibility to alcohol-induced hepatic diseases.

Experimental testing of impact force on rigid and flexible barriers - A comparison

NASA Astrophysics Data System (ADS)

Nagl, Georg; Hübl, Johannes; Chiari, Michael

2016-04-01

The Trattenbach endangers the main western railway track of Austria by floods and debris flows. Three check dams for debris retention were built in the proximal fan area several decades ago. With regard to an improvement of the protective function, these structures have to be renewed. The recent concept of the uppermost barrier is a type of an energy dissipation net structure, stopping debris flows with the ability of self-cleaning by subsequent floods or by machinery employment. The access to the basin is achieved through the slit when the net has been removed. This technical structure consists of a rigid open crown dam with a 4m wide slit. This slit is closed with a flexible net. To verify this protective system, 21 small scale experiments were conducted to test and optimize this new type of Slit Net Dam. To determine the forces on the barrier, in a first setup of experiments the impact forces on a rigid wall with 24 load cells were measured. In the second setup the slit barrier with the net was investigated. On four main cables the anchor forces were measured. In a further setup the basal distance between the channel and lowest net was varied. To study the emptying of the basin and the dosing effect on debris flows.

Biosensor Technology Reveals the Disruption of the Endothelial Barrier Function and the Subsequent Death of Blood Brain Barrier Endothelial Cells to Sodium Azide and Its Gaseous Products.

PubMed

Kho, Dan T; Johnson, Rebecca H; O'Carroll, Simon J; Angel, Catherine E; Graham, E Scott

2017-09-21

Herein we demonstrate the sensitive nature of human blood-brain barrier (BBB) endothelial cells to sodium azide and its gaseous product. Sodium azide is known to be acutely cytotoxic at low millimolar concentrations, hence its use as a biological preservative (e.g., in antibodies). Loss of barrier integrity was noticed in experiments using Electric Cell-substrate Impedance Sensing (ECIS) biosensor technology, to measure endothelial barrier integrity continuously in real-time. Initially the effect of sodium azide was observed as an artefact where it was present in antibodies being employed in neutralisation experiments. This was confirmed where antibody clones that were azide-free did not mediate loss of barrier function. A delayed loss of barrier function in neighbouring wells implied the influence of a liberated gaseous product. ECIS technology demonstrated that the BBB endothelial cells had a lower level of direct sensitivity to sodium azide of ~3 µM. Evidence of gaseous toxicity was consistently observed at 30 µM and above, with disrupted barrier function and cell death in neighbouring wells. We highlight the ability of this cellular biosensor technology to reveal both the direct and gaseous toxicity mediated by sodium azide. The sensitivity and temporal dimension of ECIS technology was instrumental in these observations. These findings have substantial implications for the wide use of sodium azide in biological reagents, raising issues of their application in live-cell assays and with regard to the protection of the user. This research also has wider relevance highlighting the sensitivity of brain endothelial cells to a known mitochondrial disruptor. It is logical to hypothesise that BBB endothelial dysfunction due to mitochondrial dys-regulation could have an important but underappreciated role in a range of neurological diseases.

A Comprehensive Biophysical Model of Ion and Water Transport in Plant Roots. I. Clarifying the Roles of Endodermal Barriers in the Salt Stress Response

PubMed Central

Foster, Kylie J.; Miklavcic, Stanley J.

2017-01-01

In this paper, we present a detailed and comprehensive mathematical model of active and passive ion and water transport in plant roots. Two key features are the explicit consideration of the separate, but interconnected, apoplastic, and symplastic transport pathways for ions and water, and the inclusion of both active and passive ion transport mechanisms. The model is used to investigate the respective roles of the endodermal Casparian strip and suberin lamellae in the salt stress response of plant roots. While it is thought that these barriers influence different transport pathways, it has proven difficult to distinguish their separate functions experimentally. In particular, the specific role of the suberin lamellae has been unclear. A key finding based on our simulations was that the Casparian strip is essential in preventing excessive uptake of Na+ into the plant via apoplastic bypass, with a barrier efficiency that is reflected by a sharp gradient in the steady-state radial distribution of apoplastic Na+ across the barrier. Even more significantly, this function cannot be replaced by the action of membrane transporters. The simulations also demonstrated that the positive effect of the Casparian strip of controlling Na+ uptake, was somewhat offset by its contribution to the osmotic stress component: a more effective barrier increased the detrimental osmotic stress effect. In contrast, the suberin lamellae were found to play a relatively minor, even non-essential, role in the overall response to salt stress, with the presence of the suberin lamellae resulting in only a slight reduction in Na+ uptake. However, perhaps more significantly, the simulations identified a possible role of suberin lamellae in reducing plant energy requirements by acting as a physical barrier to preventing the passive leakage of Na+ into endodermal cells. The model results suggest that more and particular experimental attention should be paid to the properties of the Casparian strip when assessing the salt tolerance of different plant varieties and species. Indeed, the Casparian strip appears to be a more promising target for plant breeding and plant genetic engineering efforts than the suberin lamellae for the goal of improving salt tolerance. PMID:28804493

Quantitative real-time analysis of collective cancer invasion and dissemination

NASA Astrophysics Data System (ADS)

Ewald, Andrew J.

2015-05-01

A grand challenge in biology is to understand the cellular and molecular basis of tissue and organ level function in mammals. The ultimate goals of such efforts are to explain how organs arise in development from the coordinated actions of their constituent cells and to determine how molecularly regulated changes in cell behavior alter the structure and function of organs during disease processes. Two major barriers stand in the way of achieving these goals: the relative inaccessibility of cellular processes in mammals and the daunting complexity of the signaling environment inside an intact organ in vivo. To overcome these barriers, we have developed a suite of tissue isolation, three dimensional (3D) culture, genetic manipulation, nanobiomaterials, imaging, and molecular analysis techniques to enable the real-time study of cell biology within intact tissues in physiologically relevant 3D environments. This manuscript introduces the rationale for 3D culture, reviews challenges to optical imaging in these cultures, and identifies current limitations in the analysis of complex experimental designs that could be overcome with improved imaging, imaging analysis, and automated classification of the results of experimental interventions.

Regulation of intestinal health by branched-chain amino acids.

PubMed

Zhou, Hua; Yu, Bing; Gao, Jun; Htoo, John Khun; Chen, Daiwen

2018-01-01

Besides its primary role in the digestion and absorption of nutrients, the intestine also interacts with a complex external milieu, and is the first defense line against noxious pathogens and antigens. Dysfunction of the intestinal barrier is associated with enhanced intestinal permeability and development of various gastrointestinal diseases. The branched-chain amino acids (BCAAs) are important nutrients, which are the essential substrates for protein biosynthesis. Recently, emerging evidence showed that BCAAs are involved in maintaining intestinal barrier function. It has been reported that dietary supplementation with BCAAs promotes intestinal development, enhances enterocyte proliferation, increases intestinal absorption of amino acids (AA) and glucose, and improves the immune defenses of piglets. The underlying mechanism of these effects is mediated by regulating expression of genes and proteins associate with various signaling pathways. In addition, BCAAs promote the production of beneficial bacteria in the intestine of mice. Compelling evidence supports the notion that BCAAs play important roles in both nutrition and intestinal health. Therefore, as functional amino acids with various physiological effects, BCAAs hold key roles in promoting intestinal development and health in animals and humans. © 2017 Japanese Society of Animal Science.

Dietary Cerebroside from Sea Cucumber (Stichopus japonicus): Absorption and Effects on Skin Barrier and Cecal Short-Chain Fatty Acids.

PubMed

Duan, Jingjing; Ishida, Marina; Aida, Kazuhiko; Tsuduki, Tsuyoshi; Zhang, Jin; Manabe, Yuki; Hirata, Takashi; Sugawara, Tatsuya

2016-09-21

Sphingolipids from marine sources have attracted more attention recently because of their distinctive structures and expected functions. In this study, the content and components of cerebroside from sea cucumber Stichopus japonicus were analyzed. The absorption of cerebroside from S. japonicus was investigated with an in vivo lipid absorption assay. The result revealed that S. japonicus is a rich source of cerebroside that contained considerable amounts of odd carbon chain sphingoid bases. The cumulative recoveries of d17:1- and d19:2-containing cerebrosides were 0.31 ± 0.16 and 0.32 ± 0.10%, respectively, for 24 h after administration. To the best of the authors' knowledge, this is the first work that shows sphingolipids from a marine source could be absorbed in vivo and incorporated into ceramides. In addition, dietary supplementation with sea cucumber cerebroside to hairless mouse improved the skin barrier function and increased short-chain fatty acids in cecal contents, which have shown beneficial effects on the host.

Jordanian dialysis patients' perceived exercise benefits and barriers: a correlation study.

PubMed

Darawad, Muhammad W; Khalil, Amani A

2013-01-01

To investigate Jordanian end-stage renal disease (ESRD)patients' perceived exercise benefits and barriers, and their correlation with patients' demographic variables and dialysis measures. A descriptive correlational study was conducted using cross-sectional survey, using a convenience sample of 190 ESRD dialyzed patients who were recruited from eight hospitals in Jordan. Participants significantly perceived exercise benefits (M= 2.88/4, SD± .67) higher than barriers (M= 2.66, SD± .62). The most frequent perceived exercise benefits were preventing muscular atrophy and improving mood, whereas tiredness and lower-extremity fatigue were the most frequent exercise barriers. Finally, acceptable values of Cronbach's Alpha were revealed for perceived exercise subscale, barriers subscale, and total scale (α= .88, .81, and .70, respectively). Participants focused more on exercise benefits than barriers, and on direct exercise benefits and barriers than the indirect. The results of this study have important implications for the efforts that aim at improving ESRD patients' exercise behaviors. © 2013 Association of Rehabilitation Nurses.

Self Assembly and Interface Engineering of Organic Functional Materials for High Performance Polymer Solar Cells

NASA Astrophysics Data System (ADS)

Jen, Alex

2010-03-01

The performance of polymer solar cells are strongly dependent on the efficiency of light harvesting, exciton dissociation, charge transport, and charge collection at the metal/organic, metal/metal oxide, and organic/metal oxide interfaces. To improve the device performance, two parallel approaches were used: 1) developing novel low band gap conjugated polymers with good charge-transporting properties and 2) modifying the interfaces between the organic/metal oxide and organic/metal layers with functional self-assembling monolayers to tune their energy barriers. Moreover, the molecule engineering approach was also used to tune the energy level, charge mobility, and morphology of organic semiconductors.

The Development of Environmental Barrier Coatings for SiCSiC Ceramic Matrix Composites: Challenges and Opportunities

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned CMC components to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing advanced environmental barrier coating systems, the coating integrations with next generation CMC turbine components having improved environmental stability, cyclic durability and system performance will be described. The development trends for turbine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

Tailoring Functional Chitosan-based Composites for Food Applications.

PubMed

Nunes, Cláudia; Coimbra, Manuel A; Ferreira, Paula

2018-03-08

Chitosan-based functional materials are emerging for food applications. The covalent bonding of molecular entities demonstrates to enhance resistance to the typical acidity of food assigning mechanical and moisture/gas barrier properties. Moreover, the grafting to chitosan of some functional molecules, like phenolic compounds or essential oils, gives antioxidant, antimicrobial, among others properties to chitosan. The addition of nanofillers to chitosan and other biopolymers improves the already mentioned required properties for food applications and can attribute electrical conductivity and magnetic properties for active and intelligent packaging. Electrical conductivity is a required property for the processing of food at low temperature using electric fields or for sensors application. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cuprous selenide and sulfide form improved photovoltaic barriers

NASA Technical Reports Server (NTRS)

1966-01-01

Photovoltaic barriers formed by depositing a layer of polycrystalline cuprous sulfide or cuprous selenide on gallium arsenide are chemically and electrically stable. The stability of these barrier materials is significantly greater than that of cuprous iodide.

Pediatrician-experienced barriers in the medical care for refugee children in the Netherlands.

PubMed

Baauw, A; Rosiek, S; Slattery, B; Chinapaw, M; van Hensbroek, M Boele; van Goudoever, J B; Kist-van Holthe, J

2018-04-20

Pediatricians in the Netherlands have been confronted with high numbers of refugee children in their daily practice. Refugee children have been recognized as an at-risk population because they may have an increased burden of physical and mental health conditions, and their caretakers may experience barriers in gaining access to the Dutch health care system. The aim of the study was to gain insight into the barriers in the health care for refugee children perceived by pediatricians by analyzing logistical problems reported through the Dutch Pediatric Surveillance Unit, an online system where pediatricians can report predefined conditions. Pediatricians reported 68 cases of barriers in health care ranging from mild to severe impact on the health outcome of refugee children, reported from November 2015 till January 2017. Frequent relocation of children between asylum seeker centers was mentioned in 28 of the reports on lack of continuity of care. Unknown medical history (21/68) and poor handoffs of medical records resulting in poor communication between health professionals (17/68) contributed to barriers to provide good medical care for refugee children, as did poor health literacy (17/68) and cultural differences (5/68). Frequent relocations and the unknown medical history were reported most frequently as barriers impacting the delivery of health care to refugee children. To overcome these barriers, the Committee of International Child Health of the Dutch Society of Pediatrics recommends stopping the frequent relocations, improving medical assessment upon entry in the Netherlands, improving handoff of medical records, and improving the health literacy of refugee children and their families. What is Known: • Pediatricians in the Netherlands are confronted with high numbers of refugee children • Refugee children represent a population that is especially at risk due to their increased burden of physical and mental health conditions What is New: • Refugee children experience barriers in accessing medical care • To start overcoming these barriers, we recommend that frequent relocations be stopped, health assessment upon entry in the Netherlands be improved, medical handoffs be improved, and that the refugees be empowered by increasing their health literacy.

Effects of human rhinovirus on epithelial barrier integrity and function in children with asthma.

PubMed

Looi, K; Buckley, A G; Rigby, P J; Garratt, L W; Iosifidis, T; Zosky, G R; Larcombe, A N; Lannigan, F J; Ling, K-M; Martinovich, K M; Kicic-Starcevich, E; Shaw, N C; Sutanto, E N; Knight, D A; Kicic, A; Stick, S M

2018-05-01

Bronchial epithelial tight junctions (TJ) have been extensively assessed in healthy airway epithelium. However, no studies have yet assessed the effect of human rhinovirus (HRV) infection on the expression and resultant barrier function in epithelial tight junctions (TJ) in childhood asthma. To investigate the impact of HRV infection on airway epithelial TJ expression and barrier function in airway epithelial cells (AECs) of children with and without asthma. Furthermore, to test the hypothesis that barrier integrity and function is compromised to a greater extent by HRV in AECs from asthmatic children. Primary AECs were obtained from children with and without asthma, differentiated into air-liquid interface (ALI) cultures and infected with rhinovirus. Expression of claudin-1, occludin and zonula occluden-1 (ZO-1) was assessed via qPCR, immunocytochemistry (ICC), in-cell western (ICW) and confocal microscopy. Barrier function was assessed by transepithelial electrical resistance (TER; R T ) and permeability to fluorescent dextran. Basal TJ gene expression of claudin-1 and occludin was significantly upregulated in asthmatic children compared to non-asthmatics; however, no difference was seen with ZO-1. Interestingly, claudin-1, occludin and ZO-1 protein expression was significantly reduced in AEC of asthmatic children compared to non-asthmatic controls suggesting possible post-transcriptional inherent differences. HRV infection resulted in a transient dissociation of TJ and airway barrier integrity in non-asthmatic children. Although similar dissociation of TJ was observed in asthmatic children, a significant and sustained reduction in TJ expression concurrent with both a significant decrease in TER and an increase in permeability in asthmatic children was observed. This study demonstrates novel intrinsic differences in TJ gene and protein expression between AEC of children with and without asthma. Furthermore, it correlates directly the relationship between HRV infection and the resultant dissociation of epithelial TJ that causes a continued altered barrier function in children with asthma. © 2018 John Wiley & Sons Ltd.

Intestinal epithelial barrier function and tight junction proteins with heat and exercise

PubMed Central

Zuhl, Micah N.; Moseley, Pope L.

2015-01-01

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or “leaky” intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise. PMID:26359485

Intestinal epithelial barrier function and tight junction proteins with heat and exercise.

PubMed

Dokladny, Karol; Zuhl, Micah N; Moseley, Pope L

2016-03-15

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or "leaky" intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise. Copyright © 2016 the American Physiological Society.

Does pharmaconutrition with L-arginine and/or alpha-tocopherol improve the gut barrier in bile duct ligated rats?

PubMed

Tuncyurek, P; Sari, M; Firat, O; Mutaf, I; Gulter, C; Tunger, A; Yuce, G; Yilmaz, M; Makay, O; Dayangac, M; Ersin, S

2006-01-01

Nitric oxide supplementation and antioxidant therapy modulate gut barrier function, but the relationships between enhanced nitric oxide production, antioxidant administration, and biliary obstruction remain unclear. We evaluated the role of nitric oxide and alpha-tocopherol supplementation in bile duct ligated rats. Fifty male Wistar albino rats underwent sham operation (group I; control animals) or bile duct ligation (groups II, III, IV, and V). The ligation groups received the following regimens: standard pellet diet (group II), pellet diet plus intramuscularly administered alpha-tocopherol (group III), and L-arginine-enriched pellet diet without (group IV) or with (group V) alpha-tocopherol. Nitric oxide, malondialdehyde, and alpha-tocopherol concentrations were assessed at the end of 3 weeks. Liver and intestinal samples were scored histologically. Mesenteric lymph node and liver cultures were assessed for bacterial translocation. The liver malondialdehyde concentration was highest in group III. The nitric oxide content in the liver was higher in groups III and V, as were the blood alpha-tocopherol levels. Bacterial translocation was evident following bile duct ligation, but did not differ among the treatment groups. Intestinal histology revealed that group III had the lowest villus height, that group V had the least villus count, and that group II had the highest mucous cell count. The fibrosis scores were higher in groups IV and V. An obvious effect of alpha-tocopherol (with or without L-arginine) on the gut barrier could not be demonstrated. Moreover, the L-arginine-enriched diet promoted fibrosis in the liver. Thus, while biliary duct obstruction triggers bacterial translocation, nitric oxide and/or alpha-tocopherol supplementation did not seem to improve the gut barrier in our model. Copyright 2006 S. Karger AG, Basel.

Dietary glutamine and oral antibiotics each improve indexes of gut barrier function in rat short bowel syndrome.

PubMed

Tian, Junqiang; Hao, Li; Chandra, Prakash; Jones, Dean P; Willams, Ifor R; Gewirtz, Andrew T; Ziegler, Thomas R

2009-02-01

Short bowel syndrome (SBS) is associated with gut barrier dysfunction. We examined effects of dietary glutamine (GLN) or oral antibiotics (ABX) on indexes of gut barrier function in a rat model of SBS. Adult rats underwent a 60% distal small bowel + proximal colonic resection (RX) or bowel transection (TX; control). Rats were pair fed diets with or without l-GLN for 20 days after operation. Oral ABX (neomycin, metronidazole, and polymyxin B) were given in some RX rats fed control diet. Stool secretory immunoglobulin A (sIgA) was measured serially. On day 21, mesenteric lymph nodes (MLN) were cultured for gram-negative bacteria. IgA-positive plasma cells in jejunum, stool levels of flagellin- and lipopolysaccharide (LPS)-specific sIgA, and serum total, anti-flagellin- and anti-LPS IgG levels were determined. RX caused gram-negative bacterial translocation to MLN, increased serum total and anti-LPS IgG and increased stool total sIgA. After RX, dietary GLN tended to blunt bacterial translocation to MLN (-29%, P = NS) and significantly decreased anti-LPS IgG levels in serum, increased both stool and jejunal mucosal sIgA and increased stool anti-LPS-specific IgA. Oral ABX eliminated RX-induced bacterial translocation, significantly decreased total and anti-LPS IgG levels in serum, significantly decreased stool total IgA and increased stool LPS-specific IgA. Partial small bowel-colonic resection in rats is associated with gram-negative bacterial translocation from the gut and a concomitant adaptive immune response to LPS. These indexes of gut barrier dysfunction are ameliorated or blunted by administration of dietary GLN or oral ABX, respectively. Dietary GLN upregulates small bowel sIgA in this model.

Apical electrolyte concentration modulates barrier function and tight junction protein localization in bovine mammary epithelium.

PubMed

Quesnell, Rebecca R; Erickson, Jamie; Schultz, Bruce D

2007-01-01

In vitro mammary epithelial cell models typically fail to form a consistently tight barrier that can effectively separate blood from milk. Our hypothesis was that mammary epithelial barrier function would be affected by changes in luminal ion concentration and inflammatory cytokines. Bovine mammary epithelial (BME-UV cell line) cells were grown to confluence on permeable supports with a standard basolateral medium and either high-electrolyte (H-elec) or low-electrolyte (L-elec) apical medium for 14 days. Apical media were changed to/from H-elec medium at predetermined times prior to assay. Transepithelial electrical resistance (R(te)) was highest in monolayers continuously exposed to apical L-elec. A time-dependent decline in R(te) began within 24 h of H-elec medium exposure. Change from H-elec medium to L-elec medium time-dependently increased R(te). Permeation by FITC-conjugated dextran was elevated across monolayers exposed to H-elec, suggesting compromise of a paracellular pathway. Significant alteration in occludin distribution was evident, concomitant with the changes in R(te), although total occludin was unchanged. Neither substitution of Na(+) with N-methyl-d-glucosamine (NMDG(+)) nor pharmacological inhibition of transcellular Na(+) transport pathways abrogated the effects of apical H-elec medium on R(te). Tumor necrosis factor alpha, but not interleukin-1beta nor interleukin-6, in the apical compartment caused a significant decrease in R(te) within 8 h. These results indicate that mammary epithelium is a dynamic barrier whose cell-cell contacts are acutely modulated by cytokines and luminal electrolyte environment. Results not only demonstrate that BME-UV cells are a model system representative of mammary epithelium but also provide critical information that can be applied to other mammary model systems to improve their physiological relevance.

Use of scaled external correlation, a double many-body expansion, and variational transition state theory to calibrate a potential energy surface for FH2

NASA Technical Reports Server (NTRS)

Lynch, Gillian C.; Steckler, Rozeanne; Varandas, Antonio J. C.; Truhlar, Donald G.; Schwenke, David W.

1991-01-01

New ab initio results and a double many-body expansion formalism have been used to parameterize a new FH2 potential energy surface with improved properties near the saddle point and in the region of long-range attraction. The functional form of the new surface includes dispersion forces by a double many-body expansion. Stationary point properties for the new surface are calculated along with the product-valley barrier maxima of vibrationally adiabatic potential curves for F + H2 - HF(nu-prime = 3) + H, F + HD - HF(nu-prime = 3) + D, and F + D2 - DF(nu-prime = 4) + D. The new surface should prove useful for studying the effect on dynamics of a low, early barrier with a wide, flat bend potential.

Perceptions of Approved Clinical Instructors: Barriers in the Implementation of Evidence-Based Practice

PubMed Central

Hankemeier, Dorice A.; Van Lunen, Bonnie L.

2013-01-01

Context: As evidence-based practice (EBP) becomes prevalent in athletic training education, the barriers that Approved Clinical Instructors (ACIs) experience in implementing it with students need to be understood. Objective: To investigate barriers ACIs face when implementing EBP concepts in clinical practice and in teaching EBP to professional athletic training students and to investigate the educational emphases to improve the barriers. Design: Qualitative study. Setting: Telephone interviews. Patients or Other Participants: Sixteen ACIs (11 men, 5 women; experience as an athletic trainer = 10 ± 4.7 years, experience as an ACI = 6.81 ± 3.9 years) were interviewed. Data Collection and Analysis: We interviewed each participant by telephone. Interview data were analyzed and coded for common themes and subthemes regarding barriers and educational emphases. Themes were triangulated through multiple-analyst triangulation and interpretive verification. Results: Barriers to EBP incorporation and educational emphasis placed on EBP were the main themes reported. Resources, personnel, and student characteristics were subthemes identified as barriers. Resource barriers included time, equipment, access to current literature, and knowledge. Coworkers, clinicians, and coaches who were unwilling to accept evidence regarding advancements in treatment were identified as personnel barriers. Programmatic improvement and communication improvement were subthemes of the educational emphasis placed on EBP theme. The ACIs reported the need for better integration between the clinical setting and the classroom and expressed the need for EBP to be integrated throughout the athletic training education program. Conclusions: Integration of the classroom and clinical experience is important in advancing ACIs' use of EBP with their students. Collaborative efforts within the clinical and academic program could help address the barriers ACIs face when implementing EBP. This collaboration could positively affect the ability of ACIs to implement EBP within their clinical practices. PMID:23675798

Consortium for health and military performance and American College of Sports Medicine Summit: utility of functional movement assessment in identifying musculoskeletal injury risk.

PubMed

Teyhen, Deydre; Bergeron, Michael F; Deuster, Patricia; Baumgartner, Neal; Beutler, Anthony I; de la Motte, Sarah J; Jones, Bruce H; Lisman, Peter; Padua, Darin A; Pendergrass, Timothy L; Pyne, Scott W; Schoomaker, Eric; Sell, Timothy C; O'Connor, Francis

2014-01-01

Prevention of musculoskeletal injuries (MSKI) is critical in both civilian and military populations to enhance physical performance, optimize health, and minimize health care expenses. Developing a more unified approach through addressing identified movement impairments could result in improved dynamic balance, trunk stability, and functional movement quality while potentially minimizing the risk of incurring such injuries. Although the evidence supporting the utility of injury prediction and return-to-activity readiness screening tools is encouraging, considerable additional research is needed regarding improving sensitivity, specificity, and outcomes, and especially the implementation challenges and barriers in a military setting. If selected current functional movement assessments can be administered in an efficient and cost-effective manner, utilization of the existing tools may be a beneficial first step in decreasing the burden of MSKI, with a subsequent focus on secondary and tertiary prevention via further assessments on those with prior injury history.

Advanced Ultrasound Technologies for Diagnosis and Therapy.

PubMed

Rix, Anne; Lederle, Wiltrud; Theek, Benjamin; Lammers, Twan; Moonen, Chrit; Schmitz, Georg; Kiessling, Fabian

2018-05-01

Ultrasound is among the most rapidly advancing imaging techniques. Functional methods such as elastography have been clinically introduced, and tissue characterization is improved by contrast-enhanced scans. Here, novel superresolution techniques provide unique morphologic and functional insights into tissue vascularization. Functional analyses are complemented by molecular ultrasound imaging, to visualize markers of inflammation and angiogenesis. The full potential of diagnostic ultrasound may become apparent by integrating these multiple imaging features in radiomics approaches. Emerging interest in ultrasound also results from its therapeutic potential. Various applications of tumor ablation with high-intensity focused ultrasound are being clinically evaluated, and its performance strongly benefits from the integration into MRI. Additionally, oscillating microbubbles mediate sonoporation to open biologic barriers, thus improving the delivery of drugs or nucleic acids that are coadministered or coformulated with microbubbles. This article provides an overview of recent developments in diagnostic and therapeutic ultrasound, highlighting multiple innovation tracks and their translational potential. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Barriers to Medical Compassion as a Function of Experience and Specialization: Psychiatry, Pediatrics, Internal Medicine, Surgery, and General Practice.

PubMed

Fernando, Antonio T; Consedine, Nathan S

2017-06-01

Compassion is an expectation of patients, regulatory bodies, and physicians themselves. Most research has, however, studied compassion fatigue rather than compassion itself and has concentrated on the role of the physician. The Transactional Model of Physician Compassion suggests that physician, patient, external environment, and clinical factors are all relevant. Because these factors vary both across different specialities and among physicians with differing degrees of experience, barriers to compassion are also likely to vary. We describe barriers to physician compassion as a function of specialization (psychiatry, general practice, surgery, internal medicine, and pediatrics) and physician experience. We used a cross-sectional study using demographic data, specialization, practice parameters, and the Barriers to Physician Compassion Questionnaire. Nonrandom convenience sampling was used to recruit 580 doctors, of whom 444 belonged to the targeted speciality groups. The sample was characterized before conducting a factorial Multivariate Analysis of Covariance and further post hoc analyses. A 5 (speciality grouping) × 2 (more vs. less physician experience) Multivariate Analysis of Covariance showed that the barriers varied as a function of both speciality and experience. In general, psychiatrists reported lower barriers, whereas general practitioners and internal medicine specialists generally reported greater barriers. Barriers were generally greater among less experienced doctors. Documenting and investigating barriers to compassion in different speciality groups have the potential to broaden current foci beyond the physician and inform interventions aimed at enhancing medical compassion. In addition, certain aspects of the training or practice of psychiatry that enhance compassion may mitigate barriers to compassion in other specialities. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Intrinsic incompatibilities evolving as a by-product of divergent ecological selection: Considering them in empirical studies on divergence with gene flow.

PubMed

Kulmuni, J; Westram, A M

2017-06-01

The possibility of intrinsic barriers to gene flow is often neglected in empirical research on local adaptation and speciation with gene flow, for example when interpreting patterns observed in genome scans. However, we draw attention to the fact that, even with gene flow, divergent ecological selection may generate intrinsic barriers involving both ecologically selected and other interacting loci. Mechanistically, the link between the two types of barriers may be generated by genes that have multiple functions (i.e., pleiotropy), and/or by gene interaction networks. Because most genes function in complex networks, and their evolution is not independent of other genes, changes evolving in response to ecological selection can generate intrinsic barriers as a by-product. A crucial question is to what extent such by-product barriers contribute to divergence and speciation-that is whether they stably reduce gene flow. We discuss under which conditions by-product barriers may increase isolation. However, we also highlight that, depending on the conditions (e.g., the amount of gene flow and the strength of selection acting on the intrinsic vs. the ecological barrier component), the intrinsic incompatibility may actually destabilize barriers to gene flow. In practice, intrinsic barriers generated as a by-product of divergent ecological selection may generate peaks in genome scans that cannot easily be interpreted. We argue that empirical studies on divergence with gene flow should consider the possibility of both ecological and intrinsic barriers. Future progress will likely come from work combining population genomic studies, experiments quantifying fitness and molecular studies on protein function and interactions. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.