ECONOMIC IMPORTANCE OF THE PREVENTIVE MEASURES IN DENTISTRY.

PubMed

Deljo, Emsudina; Sijercic, Zinaida; Mulaosmanovic, Amina; Musanovic, Alma; Prses, Nedim

2016-10-01

Previous studies have shown that the state of oral health in the area of Podrinje Canton is really poor. Taking into account that in the last five years are implemented two projects in the municipality it is necessary to examine the impact of preventive measures in dentistry on the oral health. a) To evaluate the impact of continuing education and local fluoridation on the state of oral health; b) To analyze the economic importance of preventive measures. For the purpose of the research on activities of continuing education on the importance of oral health and local fluoridation of teeth and to determine the economic aspects of the application of preventive measures is tested and reviewed 900 students from fourth to ninth grade. The children were divided into three groups of 300 students in each group: a) In the first group of children is carried out continuous education about proper tooth brushing and the importance of oral hygiene and local fluoridation twice a year during the last three years, b) In the second group children carried out local fluoridation twice a year during the last three years while in the third group, there were no continuous prevention measures; c) Used is a single questionnaire for all respondents. Data obtained in this study were analyzed by descriptive and inferential statistical methods. The importance of continuing education and local fluoridation is clearly reflected in the different values DMF-index, which was the subject of research. In the first group, in which is carried out continuous education and local fluoridation value of DMF index was 2.7, in the second group with local fluorination this value was 3.56, while in the third group, in which is not implemented preventive measures, the value DMF- index was 5.93. From an economic point the preventive measures are the cheapest, most effective and the best solution in order to maintain oral health.

Effect of dry mycelium of Penicillium chrysogenum fertilizer on soil microbial community composition, enzyme activities and snap bean growth.

PubMed

Wang, Bing; Liu, Huiling; Cai, Chen; Thabit, Mohamed; Wang, Pu; Li, Guomin; Duan, Ziheng

2016-10-01

The dry mycelium fertilizer (DMF) was produced from penicillin fermentation fungi mycelium (PFFM) following an acid-heating pretreatment to degrade the residual penicillin. In this study, it was applied into soil as fertilizer to investigate its effects on soil properties, phytotoxicity, microbial community composition, enzyme activities, and growth of snap bean in greenhouse. As the results show, pH, total nitrogen, total phosphorus, total potassium, and organic matter of soil with DMF treatments were generally higher than CON treatment. In addition, the applied DMF did not cause heavy metal and residual drug pollution of the modified soil. The lowest GI values (<0.3) were recorded at DMF8 (36 kg DMF/plat) on the first days after applying the fertilizer, indicating that severe phytotoxicity appeared in the DMF8-modified soil. Results of microbial population and enzyme activities illustrated that DMF was rapidly decomposed and the decomposition process significantly affected microbial growth and enzyme activities. The DMF-modified soil phytotoxicity decreased at the late fertilization time. DMF1 was considered as the optimum amount of DMF dose based on principal component analysis scores. Plant height and plant yield of snap bean were remarkably enhanced with the optimum DMF dose.

Dimethyl Fumarate Inhibits the Nuclear Factor κB Pathway in Breast Cancer Cells by Covalent Modification of p65 Protein.

PubMed

Kastrati, Irida; Siklos, Marton I; Calderon-Gierszal, Esther L; El-Shennawy, Lamiaa; Georgieva, Gergana; Thayer, Emily N; Thatcher, Gregory R J; Frasor, Jonna

2016-02-12

In breast tumors, activation of the nuclear factor κB (NFκB) pathway promotes survival, migration, invasion, angiogenesis, stem cell-like properties, and resistance to therapy--all phenotypes of aggressive disease where therapy options remain limited. Adding an anti-inflammatory/anti-NFκB agent to breast cancer treatment would be beneficial, but no such drug is approved as either a monotherapy or adjuvant therapy. To address this need, we examined whether dimethyl fumarate (DMF), an anti-inflammatory drug already in clinical use for multiple sclerosis, can inhibit the NFκB pathway. We found that DMF effectively blocks NFκB activity in multiple breast cancer cell lines and abrogates NFκB-dependent mammosphere formation, indicating that DMF has anti-cancer stem cell properties. In addition, DMF inhibits cell proliferation and significantly impairs xenograft tumor growth. Mechanistically, DMF prevents p65 nuclear translocation and attenuates its DNA binding activity but has no effect on upstream proteins in the NFκB pathway. Dimethyl succinate, the inactive analog of DMF that lacks the electrophilic double bond of fumarate, is unable to inhibit NFκB activity. Also, the cell-permeable thiol N-acetyl l-cysteine, reverses DMF inhibition of the NFκB pathway, supporting the notion that the electrophile, DMF, acts via covalent modification. To determine whether DMF interacts directly with p65, we synthesized and used a novel chemical probe of DMF by incorporating an alkyne functionality and found that DMF covalently modifies p65, with cysteine 38 being essential for the activity of DMF. These results establish DMF as an NFκB inhibitor with anti-tumor activity that may add therapeutic value in the treatment of aggressive breast cancers. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Saliva characteristics, diet and carioreceptivity in dental students.

PubMed

Chifor, Ioana; Badea, Iulia; Chifor, Radu; Popa, Dan; Staniste, Liviu; Tarmure, Dragos; Avram, Ramona

2014-01-01

The use of sugar by dental plaque microorganisms leads to acid formation from the bacteria metabolism, which determines a decrease of pH onto teeth surfaces. The value of the critical pH is 5.2-5.5. We aimed to evaluate the capacity of patients to change their diet towards caries prevention after acknowledging the values of saliva parameters (pH, buffer capacity). A group of 52 subjects were clinically examined according to the International Caries Assessment and Detection System protocol. They were required to complete a diet questionnaire and salivary tests were made for the oral mucosa hydration level, pH, buffer capacity, salivary flow rate at rest and upon stimulation. 4 pre-calibrated 6th year students and 2 dentists performed the tests and the ICDAS examination. One week after the tests, the subjects were asked to complete the diet questionnaire again. The studied group consisted of students aged between 23-26 years, randomly selected among 6(th) year students of the Faculty of Dentistry from Cluj-Napoca. The mean DMF-S index was 18.39. Most of the patients (65%) had a DMF-S index between 9 and 21. Just 2.5% had an index of 3, which was the lowest value recorded. 5% of the patients had a DMFS of 35, which was the maximal value recorded. The distribution of DMF-S was normal. 50% of the patients had no active caries. Even though most subjects (19.23%) had a pH within the normal interval, most of them were at the bottom value of the interval (6.8). Most subjects had a pH of 6.4, which is moderately acid. The mean pH was 6.7, therefore, a moderately acid one. The Pearson correlation coefficient between DMFS and pH was 0.255. A mild negative correlation (-0.275) was found between the cariogenic food and buffer capacity. A week later we noticed a statistically significant decrease of cariogenic foods and drinks in students with acid pH and with low buffer capacity. A regular intake of cakes, bonbons and chocolate was reported by subjects who had a high DMF-S value and a low saliva buffer capacity. Only after the patients were aware of their caries risk, did they change their diet towards a non-cariogenic one, even though they had had the theoretical knowledge regarding caries prevention for at least 3 years. We conclude that the use of the chair-side salivary test should be highly recommended for cario-receptive patients.

[Relationship between dental status and salivary microbiology in adolescents].

PubMed

Gábris, K; Nagy, G; Madléna, M; Dénes, Z; Márton, S; Keszthelyi, G; Bánóczy, J

1998-12-01

The authors studied caries prevalence in connection with salivary caries related findings, in 349, 14-16 years old Hungarian adolescents, living in two different cities. DMF.T, DMF-S means, stimulated salivary flow, buffer capacity, Streptococcus mutans, Lactobacillus and Candida albicans counts in saliva were determined. The ratio of cariesfrre adolescents was 4.6% in the total population sample, DMF-T mean values were 7.24 +/- 4.86, DMF-S means 10.50 +/- 8.35. Mean secretion rate of stimulated saliva was 0.84 +/- 0.50, a low buffer capacity was found in 6.3% of the examined children. Ratio of carriers of Streptococcus mutans, Lactobacilli and yeasts in saliva was 89.7%, 73.9% and 47.7% respectively. DMF-T and DMF-S values, as well as S. mutans counts were lower in the capital than in the other city. Statistically significant correlations were found between DMF-S, DMF mean values and salivary microbiological counts.

Oral health status, salivary pH status, and Streptococcus mutans counts in dental plaques and saliva of children with acute lymphoblastic leukemia.

PubMed

Mazaheri, Romina; Jabbarifar, Ebrahim; Ghasemi, Elnaz; Akkafzadeh, Elahe; Poursaeid, Elmira

2017-01-01

Acute lymphoblastic leukemia (ALL), accounting for 23% of all malignancies in children, is the most prevalent pediatric malignancy. This study compared dental caries, oral hygiene status, salivary pH, and Streptococcus mutans counts in dental plaques and saliva of children with leukemia with those of healthy controls. This case-control cross-sectional study assessed 32 children with ALL and 32 healthy children (4-9-year-old) for gingival bleeding index (GBI), decayed, missing, and filled/decayed, missing, and filled surfaces (DMF/dmfs), and plaque index (PI). Sampling was performed to determine salivary pH and S. mutans counts of the participants. The two groups matched in terms of age, gender, and socioeconomic status. The groups were compared using independent t-test, Mann-Whitney test, Chi-square test, and Spearman's and Pearson's correlation analyses. The mean DMF/dmfs and GBI were significantly higher in the ALL group (P DMF / dmfs = 0.03; P GBI = 0.04). However, the two groups were not significantly different in the mean PI values ( P = 0.47). The mean S. mutans counts in dental plaques and saliva of the children with leukemia were significantly lower than the healthy controls ( P < 0.01). Moreover, the mean salivary pH was significantly lower in the ALL group compared to the control group ( P < 0.01). Higher caries and gingival bleeding rates, higher dental plaque accumulation in children with ALL, decreased salivary pH, and cumulative effects of other risk factors highlight the significance of oral hygiene training programs (for the parents of these children) and regular dental examinations for these children.

Counteraction of Trehalose on N, N-Dimethylformamide-Induced Candida rugosa Lipase Denaturation: Spectroscopic Insight and Molecular Dynamic Simulation

PubMed Central

Yang, Xin; Jia, Yigang; Hu, Yi; Xu, Qing; Xu, Xian

2016-01-01

Candida rugosa lipase (CRL) has been widely used as a biocatalyst for non-aqueous synthesis in biotechnological applications, which, however, often suffers significant loss of activity in organic solvent. Experimental results show that trehalose could actively counteract the organic-solvent-induced protein denaturation, while the molecular mechanisms still don’t unclear. Herein, CRL was used as a model enzyme to explore the effects of trehalose on the retention of enzymatic activity upon incubation in N,N-dimethylformamide (DMF). Results showed that both catalytic activity and conformation changes of CRL influenced by DMF solvent were inhibited by trehalose in a dose-dependent fashion. The simulations further indicated that the CRL protein unfolded in binary DMF solution, but retained the native state in the ternary DMF/trehalose system. Trehalose as the second osmolyte added into binary DMF solution decreased DMF-CRL hydrogen bonds efficiently, whereas increased the intermolecular hydrogen bondings between DMF and trehalose. Thus, the origin of its denaturing effects of DMF on protein is thought to be due to the preferential exclusion of trehalose as well as the intermolecular hydrogen bondings between trehalose and DMF. These findings suggest that trehalose protect the CRL protein from DMF-induced unfolding via both indirect and direct interactions. PMID:27031946

Counteraction of Trehalose on N, N-Dimethylformamide-Induced Candida rugosa Lipase Denaturation: Spectroscopic Insight and Molecular Dynamic Simulation.

PubMed

Yang, Xin; Jiang, Ling; Jia, Yigang; Hu, Yi; Xu, Qing; Xu, Xian; Huang, He

2016-01-01

Candida rugosa lipase (CRL) has been widely used as a biocatalyst for non-aqueous synthesis in biotechnological applications, which, however, often suffers significant loss of activity in organic solvent. Experimental results show that trehalose could actively counteract the organic-solvent-induced protein denaturation, while the molecular mechanisms still don't unclear. Herein, CRL was used as a model enzyme to explore the effects of trehalose on the retention of enzymatic activity upon incubation in N,N-dimethylformamide (DMF). Results showed that both catalytic activity and conformation changes of CRL influenced by DMF solvent were inhibited by trehalose in a dose-dependent fashion. The simulations further indicated that the CRL protein unfolded in binary DMF solution, but retained the native state in the ternary DMF/trehalose system. Trehalose as the second osmolyte added into binary DMF solution decreased DMF-CRL hydrogen bonds efficiently, whereas increased the intermolecular hydrogen bondings between DMF and trehalose. Thus, the origin of its denaturing effects of DMF on protein is thought to be due to the preferential exclusion of trehalose as well as the intermolecular hydrogen bondings between trehalose and DMF. These findings suggest that trehalose protect the CRL protein from DMF-induced unfolding via both indirect and direct interactions.

Characterization of lymphopenia in patients with MS treated with dimethyl fumarate and fingolimod.

PubMed

Nakhaei-Nejad, Maryam; Barilla, David; Lee, Chieh-Hsin; Blevins, Gregg; Giuliani, Fabrizio

2018-03-01

Lymphopenia is a common occurrence of disease-modifying therapies (DMTs) for relapsing-remitting MS (RRMS). The aim of this study was to dissect the prevalence of various lymphocyte subsets in patients with RRMS treated with 2 DMTs commonly associated with lymphopenia, dimethyl fumarate (DMF), and fingolimod (FTY). Multicolor flow cytometry and multiplex assays were used to identify up to 50 lymphocyte subpopulations and to examine the expression of multiple cytokines in selected patients. We compared patients untreated (NT) or treated with FTY or DMF who did (DMF-L) or did not (DMF-N) develop lymphopenia. All FTY patients developed lymphopenia in both T-cell and B-cell compartments. CD41 T cells were more affected by this treatment than CD81 cells. In the B-cell compartment, the CD271IgD2 subpopulation was reduced. T cells but not B cells were significantly reduced in DMF-L. However, within the B cells, CD271 cells were significantly lower. Both CD41 and CD81 subpopulations were reduced in DMF-L. Within the remaining CD41 and CD81 compartments, there was an expansion of the naive subpopulation and a reduction of the effector memory subpopulation. Unactivated lymphocyte from DMF-L patients had significantly higher levels of interferon-γ, interleukin (IL)-12, IL-2, IL-4, IL-6, and IL-1β compared with DMF-N. In plasma, TNFβ was significantly higher in DMF-N and DMF-L compared with NT, whereas CCL17 was significantly higher in DMF-L compared with NT and DMF-N. This study shows that different treatments can target different lymphocyte compartments and suggests that lymphopenia can induce compensatory mechanisms to maintain immune homeostasis.

Characterization of lymphopenia in patients with MS treated with dimethyl fumarate and fingolimod

PubMed Central

Nakhaei-Nejad, Maryam; Barilla, David; Lee, Chieh-Hsin; Blevins, Gregg

2017-01-01

Objective: Lymphopenia is a common occurrence of disease-modifying therapies (DMTs) for relapsing-remitting MS (RRMS). The aim of this study was to dissect the prevalence of various lymphocyte subsets in patients with RRMS treated with 2 DMTs commonly associated with lymphopenia, dimethyl fumarate (DMF), and fingolimod (FTY). Methods: Multicolor flow cytometry and multiplex assays were used to identify up to 50 lymphocyte subpopulations and to examine the expression of multiple cytokines in selected patients. We compared patients untreated (NT) or treated with FTY or DMF who did (DMF-L) or did not (DMF-N) develop lymphopenia. Results: All FTY patients developed lymphopenia in both T-cell and B-cell compartments. CD41 T cells were more affected by this treatment than CD81 cells. In the B-cell compartment, the CD271IgD2 subpopulation was reduced. T cells but not B cells were significantly reduced in DMF-L. However, within the B cells, CD271 cells were significantly lower. Both CD41 and CD81 subpopulations were reduced in DMF-L. Within the remaining CD41 and CD81 compartments, there was an expansion of the naive subpopulation and a reduction of the effector memory subpopulation. Unactivated lymphocyte from DMF-L patients had significantly higher levels of interferon-γ, interleukin (IL)-12, IL-2, IL-4, IL-6, and IL-1β compared with DMF-N. In plasma, TNFβ was significantly higher in DMF-N and DMF-L compared with NT, whereas CCL17 was significantly higher in DMF-L compared with NT and DMF-N. Conclusions: This study shows that different treatments can target different lymphocyte compartments and suggests that lymphopenia can induce compensatory mechanisms to maintain immune homeostasis. PMID:29296636

The use of biomarkers of exposure of N,N-dimethylformamide in health risk assessment and occupational hygiene in the polyacrylic fibre industry

PubMed Central

Kafferlein, H; Ferstl, C; Burkhart-Reichl, A; Hennebruder, K; Drexler, H; Bruning, T; Angerer, J

2005-01-01

Background: N,N-dimethylformamide (DMF) was recently prioritised for field studies by the National Toxicology Program based on the potency of its reproductive toxic effects. Aims: To measure accurately exposure to DMF in occupational settings. Methods: In 35 healthy workers employed in the polyacrylic fibre industry, N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) in urine, and N-methylcarbamoylated haemoglobin (NMHb) in blood were measured. Workplace documentation and questionnaire information were used to categorise workers in groups exposed to low, medium, and high concentrations of DMF. Results: All three biomarkers can be used to identify occupational exposure to DMF. However, only the analysis of NMHb could accurately distinguish between workers exposed to different concentrations of DMF. The median concentrations were determined to be 55.1, 122.8, and 152.6 nmol/g globin in workers exposed to low, medium, and high concentrations of DMF, respectively. It was possible by the use of NMHb to identify all working tasks with increased exposure to DMF. While fibre crimpers were found to be least exposed to DMF, persons washing, dyeing, or towing the fibres were found to be highly exposed to DMF. In addition, NMHb measurements were capable of uncovering working tasks, which previously were not associated with increased exposure to DMF; for example, the person preparing the fibre forming solution. Conclusions: Measurement of NMHb in blood is recommended rather than measurement of NMF and AMCC in urine to accurately assess exposure to DMF in health risk assessment. However, NMF and AMCC are useful biomarkers for occupational hygiene intervention. Further investigations regarding toxicity of DMF should focus on highly exposed persons in the polyacrylic fibre industry. Additional measurements in occupational settings other than the polyacrylic fibre industry are also recommended, since the population at risk and the production volume of DMF are high. PMID:15837855

Synthesis, characterization, and fluorescent properties of two Pb(II) complexes: {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2}

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

Xu Qingfeng; Zhou Qiuxuan; Lu Jianmei

2007-01-15

Two novel Pb(II) complexes, {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2} (hca=trans-4-hydroxycinnamic group), were obtained by solid-phase reactions of PbAc{sub 2} and Hhca and PbAc{sub 2}, Hhca, and phen, respectively, and characterized by spectroscopy. X-ray crystallography analysis reveals that complex 1, {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} , adopts a 2-dimensional structure through the weak interactions of Pb and O atoms and that complex 2, [Pb(hca){sub 2}(phen).DMF]{sub 2}, shows a discrete dimeric structure, in which hydrogen bonds link the dimers into a 2D network. Both complexes 1 and 2 show visible fluorescence and the intensity is stronger than that of themore » ligand. More interestingly, the intensity of emission was increased at least fivefolds when the pH of the solution was adjusted to alkalinity. This can be attributed to that the deprotonization of phenolic group enhancing the conjugation of the ligand hca. These results indicate that this method may be an effective way to increase the emission intensity of similar complexes. - Graphical abstract: Two novel Pb(II) complexes: {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace}{sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2}, (hca = trans-4-hydroxycinnamic anion) were obtained and characterized. Their structures are also determined by X-ray crystal analysis. Both of complexes in DMF solution show visible fluorescence and the intensity is stronger than that of ligand. Their emission intensities are increased greatly in an alkaline solution of pH 8, which is due to the enhancement of the planar conjugation of ligand hca with the deprotonate of the phenolic group.« less

Association between metabolic control and oral health in adolescents with type 1 diabetes mellitus.

PubMed

Saes Busato, Ivana Maria; Bittencourt, Mônica Sommer; Machado, Maria Angela Naval; Grégio, Ana Maria Trindade; Azevedo-Alanis, Luciana Reis

2010-03-01

The aim of this study was to evaluate the association between metabolic control and oral health of adolescents with type 1 diabetes mellitus (DM1). A case-control epidemiologic study was performed on adolescents allocated between 2 groups: DM1 group composed of 51 with DM1, and control group composed of 51 without diabetes. In the DM1 group, metabolic control data were observed (glycosylated hemoglobin (GHb) and capillary glucose), whereby GHb < or =8.0% was considered to indicate good metabolic control (DM1-A) and >8.0% poor metabolic control (DM1-B). Oral mucosal abnormalites, Community Periodontal Index (CPI), and decayed, missing, and filled (DMF) index were documented. Salivary flow was evaluated by means of stimulated saliva collection (SSFR). Glycosylated hemoglobin values of < or =8.0% (DM1-A) were observed in 17 (24%) and >8.0% (DM1-B) in 34 (76%) of the subjects. The average DMF indexes were 1.5 (control) and 3.3 (DM1-group) (P < or = .05). The average CPIs were 0.2 (control), 1.4 (DM1-A), and 2.0 (DM1-B) (P < or = .05). Average SSFRs were 0.997 (DM1-A), 0.903 (DM1-B), and 1.224 (control) mL/min. Oral health of adolescents with DM1 was impaired regardless of metabolic control. Copyright 2010 Mosby, Inc. All rights reserved.

[Dental caries in 15-to-19-year-old adolescents in São Paulo State, Brazil, 2002].

PubMed

Gushi, Lívia Litsue; Soares, Maria da Candelária; Forni, Tania Izabel Bighetti; Vieira, Vladen; Wada, Ronaldo Seichi; de Sousa, Maria da Luz Rosário

2005-01-01

Dental caries was evaluated by surveying 15-to-19-year-olds in the State of São Paulo, Brazil, in 2002, concerning disease prevalence and severity according to age, gender, ethnicity, and public water supply fluoridation. This cross-sectional study was based on data collected through an oral dental health epidemiological survey. Adolescents (n = 1,825) were examined at their homes by 132 dentists from 35 cities in the State of São Paulo. Chi-square, Kruskal-Wallis, and Mann-Whitney tests were used (alpha = 5%). The SiC Index was used to determine the groups having higher caries experience. DMF-T was 6.44 (sd = 4.60) and SiC Index was 11.68. Caries-free frequency was 9.6%. No statistically significant difference was observed for DMF-T in relation to public water supply fluoridation; however, there was a high percentage of caries-free individuals in cities with fluoridation. Caries conditions were worse in males. A higher prevalence of decayed and missing teeth was observed in the non-white groups. Therefore, emphasis is recommended on strategies to mitigate harm by caries progression, especially in higher-risk groups.

Relapses Requiring Intravenous Steroid Use and Multiple-Sclerosis-related Hospitalizations: Integrated Analysis of the Delayed-release Dimethyl Fumarate Phase III Studies.

PubMed

Giovannoni, Gavin; Gold, Ralf; Fox, Robert J; Kappos, Ludwig; Kita, Mariko; Yang, Minhua; Sarda, Sujata P; Zhang, Ray; Viglietta, Vissia; Havrdova, Eva

2015-11-01

The purpose was to report the effects of delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) on the number of relapses requiring intravenous (IV) steroids and multiple sclerosis (MS)-related hospitalizations using integrated data from the Phase III DEFINE and CONFIRM studies. DEFINE and CONFIRM were randomized, double-blind, placebo-controlled, multicenter studies that evaluated the efficacy and safety of DMF over a 2-year period in patients with relapsing-remitting MS (RRMS). Patients were randomized (1:1:1) to receive oral DMF 240 mg BID or TID, placebo, or glatiramer acetate (CONFIRM only). Eligible subjects (aged 18-55 years) had an EDSS score of 0-5.0 and experienced either ≥1 relapse in the 12 months or had ≥1 gadolinium-enhanced lesion on brain MRI in the 6 weeks, before randomization. Data DEFINE and CONFIRM were pooled and analyzed using a negative binomial regression model (adjusted for study and region). Data obtained after subjects switched to an alternative MS therapy were not included in the analysis. Only relapses confirmed by the Independent Neurology Evaluation Committee were included in the analysis of relapses requiring IV steroids. The study population (intention-to-treat) comprised 2301 patients who received either placebo (n = 771), DMF BID (n = 769), or DMF TID (n = 761). Baseline demographic and disease characteristics were generally well balanced among treatment groups. Throughout the 2-year studies, the total number of relapses treated with methylprednisolone was 402, 221, and 209 in the placebo, DMF BID, and DMF TID groups, respectively. A smaller proportion of patients in the DMF BID (168 of 769 [21.8%]) and DMF TID (151 of 761 [19.8%]) groups experienced ≥1 relapse requiring IV steroids compared with the placebo group (284 of 771 [36.8%]). The total number of MS-related hospitalizations over 2 years was 136, 94, and 74 in the placebo, DMF BID, and DMF TID groups. A smaller proportion of patients in the DMF BID (73 of 769 [9.5%]) and DMF TID (57 of 761 [7.5%]) groups had ≥1 MS-related hospitalization compared with the placebo group (104 of 771 [13.5%]). DMF is an effective and well tolerated therapy for RRMS. In addition to clinical benefits, the use of DMF may be associated with reduced patient burden and health economic savings, resulting from a decrease in resource utilization associated with relapses. ClinicalTrials.gov identifiers: NCT00420212 and NCT00451451. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Dual Effects of N,N-dimethylformamide on Cell Proliferation and Apoptosis in Breast Cancer

PubMed Central

Zhang, Jihong; Zhou, Daibing; Zhang, Lingyun; Lin, Qunbo; Ren, Weimin; Zhang, Jinguo; Nadeem, Lubna; Xu, Guoxiong

2017-01-01

N,N-dimethylformamide (DMF) has been widely used as an organic solvent in industries. DMF is a potential medication. However, the antitumorigenic role of DMF in breast cancer remains unclear. Here, we examined dose-dependent effects of DMF on proliferation and apoptosis in breast cancer MCF-7 and nontumorous MCF-12A cells. We found that DMF had a growth inhibitory effect in MCF-12A cells in a dose-dependent manner. By contrast, however, DMF had dual effects on cell proliferation and apoptosis in MCF-7 cells. DMF at a high dose (100 mM) significantly inhibited MCF-7 cell growth while at a low dose (1 mM) significantly stimulated MCF-7 cell growth (both P < .05). The inhibitory effect of DMF on cell proliferation was accompanied by the decrease of cyclin D1 and cyclin E1 protein expression, leading to the cell cycle arrest at the G0/G1 phase. Furthermore, a high-dose DMF significantly increased the number of early apoptotic cells by increasing cleaved caspase-9 and proapoptotic protein Bax expression and decreased the ratio of Bcl-xL/Bax (P < .01). Thus, our data demonstrated for the first time that DMF has dual effects on breast cancer cell behaviors depending upon its dose. Caution must be warranted in determining its effective dose for targeting breast cancer. PMID:29238273

Digital microfluidics: A promising technique for biochemical applications

NASA Astrophysics Data System (ADS)

Wang, He; Chen, Liguo; Sun, Lining

2017-12-01

Digital microfluidics (DMF) is a versatile microfluidics technology that has significant application potential in the areas of automation and miniaturization. In DMF, discrete droplets containing samples and reagents are controlled to implement a series of operations via electrowetting-on-dielectric. This process works by applying electrical potentials to an array of electrodes coated with a hydrophobic dielectric layer. Unlike microchannels, DMF facilitates precise control over multiple reaction processes without using complex pump, microvalve, and tubing networks. DMF also presents other distinct features, such as portability, less sample consumption, shorter chemical reaction time, flexibility, and easier combination with other technology types. Due to its unique advantages, DMF has been applied to a broad range of fields (e.g., chemistry, biology, medicine, and environment). This study reviews the basic principles of droplet actuation, configuration design, and fabrication of the DMF device, as well as discusses the latest progress in DMF from the biochemistry perspective.

Complexation and phase evolution at dimethylformamide-Ag(111) interfaces

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

Song, Wentao; Leung, Kevin; Shao, Qian

The interaction of solvent molecules with metallic surfaces impacts many interfacial chemical processes. We investigate the chemical and structure evolution that follows adsorption of the polar solvent dimethylformamide (DMF) on Ag(111). An Ag(DMF) 2 coordination complex forms spontaneously by DMF etching of Ag(111), yielding mixed films of the complexes and DMF. Utilizing ultrahigh vacuum scanning tunneling microscopy (UHV-STM), in combination with X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) computations, we map monolayer phases from the 2-D gas regime, consisting of a binary mixture of DMF and Ag(DMF) 2, through the saturation monolayer limit, in which these two chemicalmore » species phase separate into ordered islands. Structural models for the near-square DMF phase and the chain-like Ag(DMF) 2 phase are presented and supported by DFT computation. Interface evolution is summarized in a surface pressure-composition phase diagram, which allows structure prediction over arbitrary experimental conditions. In conclusion, this work reveals new surface coordination chemistry for an important electrolyte-electrode system, and illustrates how surface pressure can be used to tune monolayer phases.« less

Complexation and phase evolution at dimethylformamide-Ag(111) interfaces

DOE PAGES

Song, Wentao; Leung, Kevin; Shao, Qian; ...

2016-09-15

The interaction of solvent molecules with metallic surfaces impacts many interfacial chemical processes. We investigate the chemical and structure evolution that follows adsorption of the polar solvent dimethylformamide (DMF) on Ag(111). An Ag(DMF) 2 coordination complex forms spontaneously by DMF etching of Ag(111), yielding mixed films of the complexes and DMF. Utilizing ultrahigh vacuum scanning tunneling microscopy (UHV-STM), in combination with X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) computations, we map monolayer phases from the 2-D gas regime, consisting of a binary mixture of DMF and Ag(DMF) 2, through the saturation monolayer limit, in which these two chemicalmore » species phase separate into ordered islands. Structural models for the near-square DMF phase and the chain-like Ag(DMF) 2 phase are presented and supported by DFT computation. Interface evolution is summarized in a surface pressure-composition phase diagram, which allows structure prediction over arbitrary experimental conditions. In conclusion, this work reveals new surface coordination chemistry for an important electrolyte-electrode system, and illustrates how surface pressure can be used to tune monolayer phases.« less

Comparative study of mono- and dinuclear complexes of late 3d-metal chlorides with N,N-dimethylformamide in the gas phase.

PubMed

Duchácková, Lucie; Roithová, Jana; Milko, Petr; Zabka, Jan; Tsierkezos, Nikos; Schröder, Detlef

2011-02-07

Mono- and binuclear complexes of N,N-dimethylformamide (DMF) with chlorides of the divalent, late 3d metals M = Co, Ni, Cu, and Zn are investigated by means of electrospray ionization (ESI). Specifically, ESI leads to monocations of the type [(DMF)(n)MCl](+) and [(DMF)(n)M(2)Cl(3)](+), of which the species with n = 2 and 3 were selected for in-depth studies. The latter include collision-induced dissociation experiments, gas-phase infrared spectroscopy, and calculations using density functional theory. The mononuclear complexes [(DMF)(n)MCl](+) almost exclusively lose neutral DMF upon collisional activation with the notable exception of the copper complex, for which also a reduction from Cu(II) to Cu(I) concomitant with the release of atomic chlorine is observed. For the dinuclear clusters, there exists a competition between loss of a DMF ligand and cluster degradation via loss of neutral MCl(2) with decreasing cluster stability from cobalt to zinc. For the specific case of [(DMF)(n)ZnCl](+) and [(DMF)(n)Zn(2)Cl(3)](+), ion-mobility mass spectrometry indicates the existence of two isomeric cluster ions in the case of [(DMF)(2)Zn(2)Cl(3)](+) which corroborates parallel theoretical predictions.

Three-dimensional digital microfluidic manipulation of droplets in oil medium

PubMed Central

Hong, Jiwoo; Kim, Young Kwon; Won, Dong-Joon; Kim, Joonwon; Lee, Sang Joon

2015-01-01

We here develop a three-dimensional DMF (3D DMF) platform with patterned electrodes submerged in an oil medium to provide fundamental solutions to the technical limitations of 2D DMF platforms and water–air systems. 3D droplet manipulation on patterned electrodes is demonstrated by programmably controlling electrical signals. We also demonstrate the formation of precipitates on the 3D DMF platform through the reaction of different chemical samples. A droplet containing precipitates, hanging on the top electrode, can be manipulated without adhesion of precipitates to the solid surface. This method could be a good alternative strategy to alleviate the existing problems of 2D DMF systems such as cross-contamination and solute adsorption. In addition, we ascertain the feasibility of temperature-controlled chemical reaction on the 3D DMF platform by introducing a simple heating process. To demonstrate applicability of the 3D DMF system to 3D biological process, we examine the 3D manipulation of droplets containing mouse fibroblasts in the 3D DMF platform. Finally, we show detachment of droplets wrapped by a flexible thin film by adopting the electro-elasto-capillarity (EEC). The employment of the EEC may offer a strong potential in the development of 3D DMF platforms for drug encapsulation and actuation of microelectromechanical devices. PMID:26033440

Effect of engineered environment on microbial community structure in biofilter and biofilm on reverse osmosis membrane.

PubMed

Jeong, Sanghyun; Cho, Kyungjin; Jeong, Dawoon; Lee, Seockheon; Leiknes, TorOve; Vigneswaran, Saravanamuthu; Bae, Hyokwan

2017-11-01

Four dual media filters (DMFs) were operated in a biofiltration mode with different engineered environments (DMF I and II: coagulation with/without acidification and DMF III and IV: without/with chlorination). Designed biofilm enrichment reactors (BERs) containing the removable reverse osmosis (RO) coupons, were connected at the end of the DMFs in parallel to analyze the biofilm on the RO membrane by DMF effluents. Filtration performances were evaluated in terms of dissolved organic carbon (DOC) and assimilable organic carbon (AOC). Organic foulants on the RO membrane were also quantified and fractionized. The bacterial community structures in liquid (seawater and effluent) and biofilm (DMF and RO) samples were analyzed using 454-pyrosequencing. The DMF IV fed with the chlorinated seawater demonstrated the highest reductions of DOC including LMW-N as well as AOC among the other DMFs. The DMF IV was also effective in reducing organic foulants on the RO membrane surface. The bacterial community structure was grouped according to the sample phase (i.e., liquid and biofilm samples), sampling location (i.e., DMF and RO samples), and chlorination (chlorinated and non-chlorinated samples). In particular, the biofilm community in the DMF IV differed from the other DMF treatments, suggesting that chlorination exerted as stronger selective pressure than pH adjustment or coagulation on the biofilm community. In the DMF IV, several chemoorganotrophic chlorine-resistant biofilm-forming bacteria such as Hyphomonas, Erythrobacter, and Sphingomonas were predominant, and they may enhance organic carbon degradation efficiency. Diverse halophilic or halotolerant organic degraders were also found in other DMFs (i.e., DMF I, II, and III). Various kinds of dominant biofilm-forming bacteria were also investigated in RO membrane samples; the results provided possible candidates that cause biofouling when DMF process is applied as the pretreatment option for the RO process. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Zn(INO) 2(DMF)]·DMF: A new three-dimensional supramolecular open framework containing one-dimensional channels

NASA Astrophysics Data System (ADS)

Hong, Jun

2006-02-01

A three-dimensional supramolecular compound, [Zn(INO) 2(DMF)]·DMF (1) (INO=isonicotinic acid N-oxide), has been prepared in the DMF solution at room temperature, and characterized by elemental analysis, TG and single crystal X-ray diffraction. The three-dimensional supramolecular open framework of 1 contains rectangular channels with the dimensions of 9.02×10.15 Å, assembled from one-dimensional helical chains via hydrogen-bonding and π-π stacking interactions. Furthermore, compound 1 shows blue photoluminescence at room temperature.

Bottleneck Effect of N,N-Dimethylformamide in InOF-1: Increasing CO2 Capture in Porous Coordination Polymers.

PubMed

Sánchez-González, Elí; González-Zamora, Eduardo; Martínez-Otero, Diego; Jancik, Vojtech; Ibarra, Ilich A

2017-05-15

The bottleneck effect of confined N,N-dimethylformamide (DMF) molecules was observed in InOF-1 for the first time: CO 2 capture was remarkably enhanced in samples of as-synthesized InOF-1, thermally activated in such a way that a small residual amount of DMF molecules remained confined within the pores (DMF@InOF-1). Dynamic CO 2 adsorption experiments on DMF@InOF-1 exhibited a CO 2 capture of 8.06 wt % [1.5-fold higher than that of a fully activated InOF-1 (5.24%)]. DMF@InOF-1 can reversibly adsorb/desorb 8.09% CO 2 with no loss of CO 2 capacity after 10 cycles, and the desorption is accomplished by only turning the CO 2 flow off. Static CO 2 adsorption experiments (at 196 K) demonstrated a 1.4-fold CO 2 capture increase (from 5.5 mmol·g -1 , fully activated InOF-1, to 7.5 mmol·g -1 , DMF@InOF-1). Therefore, these CO 2 capture properties are the result of the presence of residual-confined DMF molecules within the InOF-1 framework and their interactions via a very strong hydrogen bond with the In 2 (μ-OH) groups, which prevent DMF leaching. The stability of this hydrogen bond is given by a perfect fit of the DMF molecule in the "dent" around the OH group that allows a nearly ideal orientation of the DMF molecule towards the OH group.

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

Structural and spectroscopic characterization of DMF complexes with nitrogen, carbon dioxide, ammonia and water. Infrared matrix isolation and theoretical studies

NASA Astrophysics Data System (ADS)

Sałdyka, Magdalena; Mielke, Zofia; Haupa, Karolina

2018-02-01

An infrared spectroscopic and MP2/6-311++G(2d,2p) study of the complexes between N,N-dimethylformamide (DMF) and nitrogen, carbon dioxide, water, ammonia trapped in solid argon matrices is reported. The 1:1 molecular complexes have been identified in the DMF/B/Ar matrices (B = N2, CO, H2O, NH3); their structures were determined by comparison of the spectra with the results of calculations. The analysis of the experimental and theoretical data indicate that the DMF-N2, CO complexes present in the matrices are stabilized by (C=)O⋯N and (C=)O⋯C van der Waals interactions. In turn, in the DMF-H2O, NH3 complexes the (C=)O⋯H(OH) and (C=)O⋯H(NH2) hydrogen bonding is present in which the carbonyl group of DMF acts as a proton acceptor. In all systems studied the C-H⋯X (X = N, C, O) bonding is a second intermolecular force stabilizing the planar complexes. Some spectral features indicate that for DMF-H2O, DMF-NH3 systems the nonplanar structures with the C=O⋯H interaction are also present. The study demonstrated the strong sensitivity of the CH stretching wavenumber to an involvement of the C-H and/or C=O groups of DMF in an intermolecular interaction.

TCRs Used in Cancer Gene Therapy Cross-React with MART-1/Melan-A Tumor Antigens via Distinct Mechanisms

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

Borbulevych, Oleg Y.; Santhanagopolan, Sujatha M.; Hossain, Moushumi

2013-09-18

T cells engineered to express TCRs specific for tumor Ags can drive cancer regression. The first TCRs used in cancer gene therapy, DMF4 and DMF5, recognize two structurally distinct peptide epitopes of the melanoma-associated MART-1/Melan-A protein, both presented by the class I MHC protein HLA-A*0201. To help understand the mechanisms of TCR cross-reactivity and provide a foundation for the further development of immunotherapy, we determined the crystallographic structures of DMF4 and DMF5 in complex with both of the MART-1/Melan-A epitopes. The two TCRs use different mechanisms to accommodate the two ligands. Although DMF4 binds the two with a different orientation,more » altering its position over the peptide/MHC, DMF5 binds them both identically. The simpler mode of cross-reactivity by DMF5 is associated with higher affinity toward both ligands, consistent with the superior functional avidity of DMF5. More generally, the observation of two diverging mechanisms of cross-reactivity with the same Ags and the finding that TCR-binding orientation can be determined by peptide alone extend our understanding of the mechanisms underlying TCR cross-reactivity.« less

T cell receptors used in cancer gene therapy cross-react with MART-1/Melan-A tumor antigens via distinct mechanisms1

PubMed Central

Borbulevych, Oleg Y.; Santhanagopolan, Sujatha M.; Hossain, Moushumi; Baker, Brian M.

2011-01-01

T cells engineered to express T cell receptors (TCRs) specific for tumor antigens can drive cancer regression. The first TCRs used in cancer gene therapy, DMF4 and DMF5, recognize two structurally distinct peptide epitopes of the melanoma-associated MART-1/Melan-A protein, both presented by the class I MHC protein HLA-A*0201. To help understand the mechanisms of TCR cross-reactivity and provide a foundation for the further development of immunotherapy, we determined the crystallographic structures of DMF4 and DMF5 in complex with both of the MART-1/Melan-A epitopes. The two TCRs use different mechanisms to accommodate the two ligands. Whereas DMF4 binds the two with a different orientation, altering its position over the peptide/MHC, DMF5 binds them both identically. The simpler mode of cross-reactivity by DMF5 is associated with higher affinity towards both ligands, consistent with the superior functional avidity of DMF5. More generally, the observation of two diverging mechanisms of cross-reactivity with the same antigens and the finding that TCR binding orientation can be determined by peptide alone extend our understanding of the mechanisms underlying TCR cross-reactivity. PMID:21795600

Shoe contact dermatitis from dimethyl fumarate: clinical manifestations, patch test results, chemical analysis, and source of exposure.

PubMed

Giménez-Arnau, Ana; Silvestre, Juan Francisco; Mercader, Pedro; De la Cuadra, Jesus; Ballester, Isabel; Gallardo, Fernando; Pujol, Ramón M; Zimerson, Erik; Bruze, Magnus

2009-11-01

The methyl ester form of fumaric acid named dimethyl fumarate (DMF) is an effective mould-growth inhibitor. Its irritating and sensitizing properties were demonstrated in animal models. Recently, DMF has been identified as responsible for furniture contact dermatitis in Europe. To describe the clinical manifestations, patch test results, shoe chemical analysis, and source of exposure to DMF-induced shoe contact dermatitis. Patients with suspected shoe contact dermatitis were studied in compliance with the Declaration of Helsinki. Patch test results obtained with their own shoe and the European baseline series, acrylates and fumaric acid esters (FAE), were recorded according to international guidelines. The content of DMF in shoes was analysed with gas chromatography and mass spectrometry. Acute, immediate irritant contact dermatitis and non-immunological contact urticaria were observed in eight adults and two children, respectively. All the adult patients studied developed a delayed sensitization demonstrated by a positive patch testing to DMF < or = 0.1% in pet. Cross-reactivity with other FAEs and acrylates was observed. At least 12 different shoe brands were investigated. The chemical analysis from the available shoes showed the presence of DMF. DMF in shoes was responsible for severe contact dermatitis. Global preventive measures for avoiding contact with DMF are necessary.

Low-Dose N,N-Dimethylformamide Exposure and Liver Injuries in a Cohort of Chinese Leather Industry Workers.

PubMed

Qi, Cong; Gu, Yiyang; Sun, Qing; Gu, Hongliang; Xu, Bo; Gu, Qing; Xiao, Jing; Lian, Yulong

2017-05-01

We assessed the risk of liver injuries following low doses of N,N-dimethylformamide (DMF) below threshold limit values (20 mg/m) among leather industry workers and comparison groups. A cohort of 429 workers from a leather factory and 466 non-exposed subjects in China were followed for 4 years. Poisson regression and piece-wise linear regression were used to examine the relationship between DMF and liver injury. Workers exposed to a cumulative dose of DMF were significantly more likely than non-exposed workers to develop liver injury. A nonlinear relationship between DMF and liver injury was observed, and a threshold of the cumulative DMF dose for liver injury was 7.30 (mg/m) year. The findings indicate the importance of taking action to reduce DMF occupational exposure limits for promoting worker health.

Allergic rhinitis and dental caries in preschool children

PubMed Central

Bakhshaee, Mehdi; Ashtiani, Sara Jafari; Hossainzadeh, Mana; Sehatbakhsh, Samineh; Najafi, Mona Najaf; Salehi, Maryam

2017-01-01

Background: Allergic rhinitis (AR) may be overdocumented in cases of dental caries because of controversies in the literature This study was conducted to investigate the potential relationship between AR and dental caries in children. Materials and Methods: A total of 296 children were included in this cross-sectional study. Participants were evaluated using the decay-missing-filled (DMF) index, and their AR status was evaluated by physical examination and through a standard questionnaire. Baseline demographics and clinical characteristics were compared among groups using Student's t-test or the Mann–Whitney U-test, the Chi-square test, and/or Fisher's exact test as appropriate. A level of P < 0.05 was regarded as statistically significant. Results: Evidence of AR was found in 77 (35.1%) participants. There was no significant difference in the rate of tooth decay or DMF between participants with or without AR (P = 0.07), but a significant difference was observed in the number of missing and filled teeth between those with and without AR (P < 0.05). There were no significant differences in educational level, family income, milk intake, use of pacifier, use of a toothbrush, saliva secretion, or body mass index (P > 0.05 in all cases) between AR-positive and AR-negative patients. Fluoride therapy and oral breathing were identified as confounding factors and controlled using log-linear analysis. The mean rate of DMF in patients who also had AR was 20% greater than in the AR-negative group (odds ratio [OR] = 1.21, confidence interval [CI]: 1.05–1.35) and 15% greater in among children who breathed orally than those who did not (OR = 1.15 CI: 1.02–1.31). Conclusion: AR and oral breathing may have an effect on oral health and dental condition, leading to an increased rate of tooth loss, oral fillings, and development of dental caries. PMID:29238375

Dimethyl fumarate–induced lymphopenia in MS due to differential T-cell subset apoptosis

PubMed Central

Ghadiri, Mahtab; Rezk, Ayman; Li, Rui; Evans, Ashley; Luessi, Felix; Zipp, Frauke; Giacomini, Paul S.; Antel, Jack

2017-01-01

Objective: To examine the mechanism underlying the preferential CD8+ vs CD4+ T-cell lymphopenia induced by dimethyl fumarate (DMF) treatment of MS. Methods: Total lymphocyte counts and comprehensive T-cell subset analyses were performed in high-quality samples obtained from patients with MS prior to and serially following DMF treatment initiation. Random coefficient mixed-effects analysis was used to model the trajectory of T-cell subset losses in vivo. Survival and apoptosis of distinct T-cell subsets were assessed following in vitro exposure to DMF. Results: Best-fit modeling indicated that the DMF-induced preferential reductions in CD8+ vs CD4+ T-cell counts nonetheless followed similar depletion kinetics, suggesting a similar rather than distinct mechanism involved in losses of both the CD8+ and CD4+ T cells. In vitro, DMF exposure resulted in dose-dependent reductions in T-cell survival, which were found to reflect apoptotic cell death. This DMF-induced apoptosis was greater for CD8+ vs CD4+, as well as for memory vs naive, and conventional vs regulatory T-cell subsets, a pattern which mirrored preferential T-cell subset losses that we observed during in vivo treatment of patients. Conclusions: Differential apoptosis mediated by DMF may underlie the preferential lymphopenia of distinct T-cell subsets, including CD8+ and memory T-cell subsets, seen in treated patients with MS. This differential susceptibility of distinct T-cell subsets to DMF-induced apoptosis may contribute to both the safety and efficacy profiles of DMF in patients with MS. PMID:28377940

Design of oral agents for the management of multiple sclerosis: benefit and risk assessment for dimethyl fumarate

PubMed Central

Nicholas, Jacqueline Ann; Boster, Aaron Lee; Imitola, Jaime; O’Connell, Colleen; Racke, Michael Karl

2014-01-01

Dimethyl fumarate (DMF) is the most recent oral disease-modifying therapy approved by the US Food and Drug Administration and is indicated for the treatment of relapsing forms of multiple sclerosis (MS). Prior to approval for use in MS, DMF and its active metabolite, monomethyl fumarate, had been used for decades as two of the fumaric acid esters in Fumaderm®, a medication used in Europe for the treatment of psoriasis. The unique mechanism of action of DMF remains under evaluation; however, it has been shown to act through multiple pathways leading to shifts away from the Th1 proinflammatory response to the less inflammatory Th2 response. Preliminary data suggest that DMF may induce neuroprotective effects in central nervous system white matter, although further studies are needed to demonstrate these effects on inflammatory demyelination. The DMF Phase III clinical trials demonstrated its efficacy with regard to a reduction in the annualized relapse rate and reductions in new or enlarging T2 lesions and numbers of gadolinium-enhancing lesions on magnetic resonance imaging. DMF has a well-defined safety profile, given the experience with its use in the treatment of psoriasis, and more recently from the DMF clinical trials program and post-marketing era for treatment of MS. The safety profile and oral mode of administration of DMF place it as an attractive first-line therapy option for the treatment of relapsing forms of MS. Long-term observational studies will be needed to determine the effects of DMF on progression of disability in MS. PMID:25045248

Static and dynamic light scattering studies on dilute polyrotaxane solutions

NASA Astrophysics Data System (ADS)

Kume, Tetsuya; Araki, Jun; Sakai, Yasuhiro; Mayumi, Koichi; Kidowaki, Masatoshi; Yokoyama, Hideaki; Ito, Kohzo

2009-08-01

Static and dynamic light scattering measurements were performed for dilute polyrotaxane solutions in different types of solvent systems, i.e. dimethylacetamide (DMAc) or dimethylformamide (DMF) containing 1-6 wt% lithium chloride (LiCl), 1 M aqueous sodium hydroxide (NaOH) and dimethylsulfoxide (DMSO). No aggregation of the polyrotaxane in DMF/LiCl was confirmed in the present study. Radius of gyration of the dissolved polyrotaxane was largest in NaOHaq., followed by values in amide solvents/LiCl and that in DMSO, and was probably dominated not by Coulombic repulsion but by the mutual affinity between solvent and polyrotaxane. Ratio of radius of gyration to hydrodynamic radius suggested the flexible random-coiled conformation in DMSO and relatively more extended, semi-flexible ones in amide solvents/LiCl and NaOHaq. The obtained values of second virial coefficient and weight average molecular weight seemed to be affected by a potential change in differential refractive index increments, caused by selective macrocationization or ionization.

Matrix completion by deep matrix factorization.

PubMed

Fan, Jicong; Cheng, Jieyu

2018-02-01

Conventional methods of matrix completion are linear methods that are not effective in handling data of nonlinear structures. Recently a few researchers attempted to incorporate nonlinear techniques into matrix completion but there still exists considerable limitations. In this paper, a novel method called deep matrix factorization (DMF) is proposed for nonlinear matrix completion. Different from conventional matrix completion methods that are based on linear latent variable models, DMF is on the basis of a nonlinear latent variable model. DMF is formulated as a deep-structure neural network, in which the inputs are the low-dimensional unknown latent variables and the outputs are the partially observed variables. In DMF, the inputs and the parameters of the multilayer neural network are simultaneously optimized to minimize the reconstruction errors for the observed entries. Then the missing entries can be readily recovered by propagating the latent variables to the output layer. DMF is compared with state-of-the-art methods of linear and nonlinear matrix completion in the tasks of toy matrix completion, image inpainting and collaborative filtering. The experimental results verify that DMF is able to provide higher matrix completion accuracy than existing methods do and DMF is applicable to large matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Severe multiple sclerosis reactivation during prolonged lymphopenia after dimethyl fumarate discontinuation.

PubMed

Zecca, C; Antozzi, C G; Torri Clerici, V; Ferrazzini, M; Mantegazza, R E; Rossi, S; Gobbi, C

2018-06-01

Delayed-release dimethyl fumarate (DMF) treatment can be associated with reduced lymphocyte and leucocyte counts, which might persist after DMF discontinuation. We report the case of a patient with severe disease reactivation despite prolonged lymphopenia after DMF discontinuation. We describe the frequency and impact of prolonged lymphopenia after DMF discontinuation at two tertiary MS centres. A 36-year-old female patient with multiple sclerosis was switched to DMF after 14 years of treatment with interferon beta-1a. DMF was suspended after 4 months because of persistent lymphopenia for 3 months. Six months later, the patient had a severe relapse with multiple enhancing brain lesions at MRI although lymphopenia was still persistent. Haematological assessment excluded other causes of lymphopenia, which was evaluated as a probable iatrogenic complication of DMF. The patient was treated with i.v. methylprednisolone 1 gr daily for 3 days with clinical recovery. Prolonged lymphopenia after DMT discontinuation does not protect against disease reactivation. Starting a new immune therapy should be balanced against the option of a "wait and see." A different immunotherapeutic strategy such as an anti-B therapeutic approach could be considered. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of N,N-dimethylformamide on behaviour and regeneration of planarian Dugesia japonica.

PubMed

Zhang, Jianyong; Yuan, Zuoqing; Zheng, Mingyue; Sun, Yuqian; Wang, Youjun; Yang, Shudong

2013-09-01

In this study, the toxicity, behavioural and regeneration effects of dimethylformamide (DMF) on planarian Dugesia japonica were investigated. One control and six different concentrations of DMF (10 ppm, 100 ppm, 500 ppm, 1000 ppm, 5000 ppm and 10,000 ppm) were used in triplicate. The results showed that the mortality was directly proportional to the DMF concentration and planarian locomotor velocity (pLMV) was significantly reduced by increasing the exposure time and DMF concentration. pLMV of D. japonica was significantly reduced at a lower concentration of 10 ppm after 7 days of continuous exposure to DMF. The recovery of the motility of planarians pretreated with DMF was found to be time- and dose dependent, all planarians had complete recovery in their motility after 48 h. The appearance of auricles in regenerating animals was easily affected by DMF exposure in comparison with the appearance of eyespot. The present results suggest that the intact adult mobility in the aquatic planarian D. japonica is a more sensitive biomarker than mortality, and the appearance of auricles in regenerating animals is a more sensitive biomarker than eyespot.

Shock tube and chemical kinetic modeling study of the oxidation of 2,5-dimethylfuran.

PubMed

Sirjean, Baptiste; Fournet, René; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique; Wang, Weijing; Oehlschlaeger, Matthew A

2013-02-21

A detailed kinetic model describing the oxidation of 2,5-dimethylfuran (DMF), a potential second-generation biofuel, is proposed. The kinetic model is based upon quantum chemical calculations for the initial DMF consumption reactions and important reactions of intermediates. The model is validated by comparison to new DMF shock tube ignition delay time measurements (over the temperature range 1300-1831 K and at nominal pressures of 1 and 4 bar) and the DMF pyrolysis speciation measurements of Lifshitz et al. [ J. Phys. Chem. A 1998 , 102 ( 52 ), 10655 - 10670 ]. Globally, modeling predictions are in good agreement with the considered experimental targets. In particular, ignition delay times are predicted well by the new model, with model-experiment deviations of at most a factor of 2, and DMF pyrolysis conversion is predicted well, to within experimental scatter of the Lifshitz et al. data. Additionally, comparisons of measured and model predicted pyrolysis speciation provides validation of theoretically calculated channels for the oxidation of DMF. Sensitivity and reaction flux analyses highlight important reactions as well as the primary reaction pathways responsible for the decomposition of DMF and formation and destruction of key intermediate and product species.

Dimethyl fumarate is highly cytotoxic in KRAS mutated cancer cells but spares non-tumorigenic cells.

PubMed

Bennett Saidu, Nathaniel Edward; Bretagne, Marie; Mansuet, Audrey Lupo; Just, Pierre-Alexandre; Leroy, Karen; Cerles, Olivier; Chouzenoux, Sandrine; Nicco, Carole; Damotte, Diane; Alifano, Marco; Borghese, Bruno; Goldwasser, François; Batteux, Frédéric; Alexandre, Jérôme

2018-02-06

KRAS mutation, one of the most common molecular alterations observed in adult carcinomas, was reported to activate the anti-oxidant program driven by the transcription factor NRF2 (Nuclear factor-erythroid 2-related factor 2). We previously observed that the antitumoral effect of Dimethyl fumarate (DMF) is dependent of NRF2 pathway inhibition. We used in vitro methods to examine the effect of DMF on cell death and the activation of the NRF2/DJ-1 antioxidant pathway. We report here that DMF is preferentially cytotoxic against KRAS mutated cancer cells. This effect was observed in patient-derived cancer cell lines harbouring a G12V KRAS mutation, compared with cell lines without such a mutation. In addition, KRAS*G12V over-expression in the human Caco-2 colon cancer cell line significantly promoted DMF-induced cell death, as well as DMF-induced- reactive oxygen species (ROS) formation and -glutathione (GSH) depletion. Moreover, in contrast to malignant cells, our data confirms that the same concentration of DMF has no significant cytotoxic effects on non-tumorigenic human ARPE-19 retinal epithelial, murine 3T3 fibroblasts and primary mice bone marrow cells; but is rather associated with NRF2 activation, decreased ROS and increased GSH levels. Furthermore, DJ-1 down-regulation experiments showed that this protein does not play a protective role against NRF2 in non-tumorigenic cells, as it does in malignant ones. This, interestingly, could be at the root of the differential effect of DMF observed between malignant and non-tumorigenic cells. Our results suggest for the first time that the dependence on NRF2 observed in mutated KRAS malignant cells makes them more sensitive to the cytotoxic effect of DMF, which thus opens up new prospects for the therapeutic applications of DMF.

Dimethylformamide is not better than glycerol for cryopreservation of boar semen.

PubMed

Malo, C; Gil, L; Cano, R; Martínez, F; García, A; Jerez, R A

2012-05-01

To improve the boar sperm cryopreservation process, the influence of the sugar (lactose, trehalose) source and the cryoprotectant [glycerol, dimethylformamide (DMF)] on the success of freezing was investigated. Sperm samples were frozen in one of six extenders: lactose plus 3% glycerol (LG); lactose plus 1.5% glycerol and 1.5% DMF (LGD); lactose plus 3% DMF (LD); trehalose plus 3% glycerol (TG); trehalose plus 1.5% glycerol and 1.5% DMF (TGD); trehalose plus 3% DMF (TD). Effects on motility, viability, acrosome integrity and hypoosmotic test (HOST) were measured. The results showed that extender containing 3% glycerol retained the highest motility percentages. In regard to viability and acrosome integrity, all extenders yielded similar rates except for the decreasing values of TD. Endosmosis was diminished in TD and LD at 2 h (P = 0.0018), as compared with the others. The results of the study demonstrated that the use of DMF as a cryoprotectant adversely affected boar sperm quality after cryopreservation. © 2011 Blackwell Verlag GmbH.

Dental caries and social factors: impact on quality of life in Brazilian children.

PubMed

Martins, Milene Torres; Sardenberg, Fernanda; Vale, Míriam Pimenta; Paiva, Saul Martins; Pordeus, Isabela Almeida

2015-01-01

The objective of this study was to evaluate the impact of dental caries and social determinants in the Oral Health Related Quality of Life (OHRQoL) of children in Belo Horizonte, Brazil. This is a population-based cross-sectional study with a representative sample of 1,204 children aged 8 to 10 years randomly selected from 19 public and private schools. The children were clinically examined at school by two trained and calibrated examiners (Kappa = 0.78 - 1.00). The Decayed, Missing and Filled Teeth Index (DMF-T and dmf-t) was used for the diagnosis of dental caries. The social factors were determined by parents'/caregivers' schooling, household income, number of people in the household, type of school, and by the Social Vulnerability Index. The Brazilian version of the Child Perceptions Questionnaire for ages 8 to 10 years was used to assess the impact on quality of life. A total of 278 (23.1%) out of 1,204 children had at least one cavitated carious lesion and 47.0% presented a negative impact on OHRQoL. In the final multivariate Poisson's regression model, household income and presence of untreated dental caries were statistically associated with a negative impact on OHRQoL (p < 0.001).Children with dental caries and from low-income families had a higher negative impact on OHRQoL.

Study on the association between residential exposure to N, N-dimethylformamide and hospitalization for respiratory disease

NASA Astrophysics Data System (ADS)

Wang, Cui; Tian, WeiLi; Wei, YuMei; Li, XiaoXiao; Zhang, QingYu; Huang, ChanKe

2013-10-01

Some studies have confirmed the adverse effects of N, N-dimethylformamide (DMF) on the different organs in occupational exposure workers. However, to the best of our knowledge, risk assessment in the general population has not been available. In this study, a time series analysis of the relationship between DMF exposure and respiratory hospitalization was performed in Longwan district of China in 2008. Generalized additive model (GAMs) reflected that a 101.0 μg m-3 (inter-quartile range) increase in the 1-day lag concentration of DMF resulted in a 1.17 (95% CI: 1.09-1.25) increased relative risk of hospitalization for respiratory problems. The dose-response curve representing the relationship between DMF and the logarithm of the number of hospitalization was adequately linear at 4-200 μg m-3. We proposed a risk on respiratory disease in non-occupational DMF exposure. More information is required to verify this observation and the other endpoints to general population should be investigated during long-term DMF exposure.

Determination of the relationship between major fault and zinc mineralization using fractal modeling in the Behabad fault zone, central Iran

NASA Astrophysics Data System (ADS)

Adib, Ahmad; Afzal, Peyman; Mirzaei Ilani, Shapour; Aliyari, Farhang

2017-10-01

The aim of this study is to determine a relationship between zinc mineralization and a major fault in the Behabad area, central Iran, using the Concentration-Distance to Major Fault (C-DMF), Area of Mineralized Zone-Distance to Major Fault (AMZ-DMF), and Concentration-Area (C-A) fractal models for Zn deposit/mine classification according to their distance from the Behabad fault. Application of the C-DMF and the AMZ-DMF models for Zn mineralization classification in the Behabad fault zone reveals that the main Zn deposits have a good correlation with the major fault in the area. The distance from the known zinc deposits/mines with Zn values higher than 29% and the area of the mineralized zone of more than 900 m2 to the major fault is lower than 1 km, which shows a positive correlation between Zn mineralization and the structural zone. As a result, the AMZ-DMF and C-DMF fractal models can be utilized for the delineation and the recognition of different mineralized zones in different types of magmatic and hydrothermal deposits.

PHOTOCHEMICAL REACTION OF NITRO-POLYCYCLIC AROMATIC HYDROCARBONS: EFFECT BY SOLVENT AND STRUCTURE

PubMed Central

Stewart, Gernerique; Smith, Keonia; Chornes, Ashley; Harris, Tracy; Honeysucker, Tiffany; Dasary, Suman Raj; Yu, Hongtao

2010-01-01

Photochemical degradation of 1-nitropyrene, 2-nitrofluorene, 2,7-dinitrofluorene, 6-nitrochrysene, 3-nitrofluoranthene, 5-nitroacenaphthene, and 9-nitroanthracene were examined in CHCl3, CH2Cl2, DMF, DMF/H2O (80/20), CH3CN, or CH3CN/H2O (80/20). The degradation follows mostly the 1st order kinetics; but a few follow 2nd order kinetics or undergo self-catalysis. The photodegradation rates follow the order: CHCl3 > CH2Cl2 > DMF > DMF/H2O > CH3CN > CH3CN/H2O. DMF is an exceptional solvent because 3 of the 7 compounds undergo self-catalytic reaction. 9-Nitroanthracene, which has a perpendicular nitro group, is the fastest, while the more compact 1-nitropyrene and 3-nitrofluoranthene, are the slowest degrading compounds. PMID:21170286

Fingolimod vs dimethyl fumarate in multiple sclerosis: A real-world propensity score-matched study.

PubMed

Prosperini, Luca; Lucchini, Matteo; Haggiag, Shalom; Bellantonio, Paolo; Bianco, Assunta; Buscarinu, Maria Chiara; Buttari, Fabio; Centonze, Diego; Cortese, Antonio; De Giglio, Laura; Fantozzi, Roberta; Ferraro, Elisabetta; Fornasiero, Arianna; Francia, Ada; Galgani, Simonetta; Gasperini, Claudio; Marfia, Girolama Alessandra; Millefiorini, Enrico; Nociti, Viviana; Pontecorvo, Simona; Pozzilli, Carlo; Ruggieri, Serena; Salvetti, Marco; Sgarlata, Eleonora; Mirabella, Massimiliano

2018-06-06

To directly compare fingolimod (FNG) and dimethyl fumarate (DMF) on no evident disease activity (NEDA) status in patients with relapsing-remitting multiple sclerosis (RRMS) from 7 multiple sclerosis outpatient clinics in Central Italy. We analyzed data of patients with RRMS who started an oral agent, namely DMF or FNG, either as first treatment (naives) or after switching from self-injectable drugs (switchers). We performed a propensity score (PS)-based nearest-neighbor matching within a caliper of 0.05 to select patients with homogeneous baseline characteristics. Pairwise censoring was adopted to adjust for difference in length of follow-up between the 2 treatment groups. Comparisons were then conducted in matched samples with Cox models (stratified by center) with NEDA-3 as the main outcome. NEDA-3 was defined as no relapses, no disability worsening, and no MRI activity. Overall, 483 and 456 patients eligible for analysis started on FNG and DMF, respectively. The PS-matching procedure retained a total of 550 patients (275 per group). After a median on-study follow-up of 18 months, the proportions of patients with NEDA-3 were similar (FNG 73%, DMF 70%; hazard ratio [HR] 0.74, p = 0.078). Subgroup analyses showed a comparable effectiveness of the 2 drugs in naives (n = 170, HR 1.15, p = 0.689), whereas FNG was superior to DMF in the achievement of NEDA-3 status among switchers (n = 380, HR 0.57, p = 0.007). We found no significant difference between FNG and DMF on NEDA-3 status, while subgroup analyses suggest the superiority of FNG over DMF in patients switching from self-injectable drugs. This study provides Class IV evidence that for patients with RRMS, DMF and FNG have comparable efficacy in treatment-naive patients and that FNG is superior to DMF in patients switching from self-injectable drugs. © 2018 American Academy of Neurology.

Efficacy and tolerability of dimethyl fumarate in White-, African- and Hispanic- Americans with multiple sclerosis.

PubMed

Zhovtis Ryerson, Lana; Green, Rivka; Confident, Gladyne; Pandey, Krupa; Richter, Benjamin; Bacon, Tamar; Sammarco, Carrie; Laing, Lisa; Kalina, Jennifer; Kister, Ilya

2016-11-01

Dimethyl fumarate (DMF) was approved by the US Food and Drug Administration (FDA) for treatment of relapsing-remitting multiple sclerosis (RRMS) based on two phase III randomized clinical trials (RCTs). There were not enough non-White patients enrolled in these RCTs to allow for subgroup analysis based on race. Efficacy and tolerability of DMF therapy across various racial groups is unknown. Retrospective chart review was performed on all patients with RRMS who were started on DMF in two tertiary multiple sclerosis (MS) clinics. Efficacy and tolerability of DMF was compared across three self-identified racial groups: White-American (WA), African-American (AA) and Hispanic-American (HA). A total of 390 RRMS patients were included in the study: 261 (66.9%) WA, 69 (17.7%) AA and 52 (13.3%) HA. When comparing 'pre-DMF' (1 year) and 'on DMF' (mean follow up of 14 months) periods, statistically significant reduction in rates of annualized relapses (WA from 0.44 to 0.19, AA from 0.39 to 0.15, and HA from 0.39 to 0.14; no differences between groups), new T2 lesions (WA from 45% to 23%, AA from 39% to 23%, HA from 52% to 26%; no difference between groups), and Gd+ lesions (WA from 25% to 13%, AA from 24% to 7%, HA from 23% to 12%; no difference between groups) were seen. DMF was relatively well tolerated across all groups, with an overall discontinuation rate of 20% (no difference between the three groups). Efficacy of DMF in our clinic population did not differ across three major ethnic groups, WA, AA and HA, and was comparable with results observed in the pivotal studies. These 'real-life' data suggest that race is not a factor that needs to be taken into account when initiating DMF.

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices.

PubMed

Jebrail, Mais J; Renzi, Ronald F; Sinha, Anupama; Van De Vreugde, Jim; Gondhalekar, Carmen; Ambriz, Cesar; Meagher, Robert J; Branda, Steven S

2015-01-07

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate that this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4-95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. This simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.

Evaluation of Potential Drug–Drug Interaction Between Delayed‐Release Dimethyl Fumarate and a Commonly Used Oral Contraceptive (Norgestimate/Ethinyl Estradiol) in Healthy Women

PubMed Central

Nestorov, Ivan; Zhao, Guolin; Meka, Venkata; Leahy, Mark; Kam, Jeanelle; Sheikh, Sarah I.

2017-01-01

Abstract Delayed‐release dimethyl fumarate (DMF) is an oral therapy for relapsing multiple sclerosis with anti‐inflammatory and neuroprotective properties. This 2‐period crossover study was conducted to evaluate the potential for drug–drug interaction between DMF (240 mg twice daily) and a combined oral contraceptive (OC; norgestimate 250 μg, ethinyl estradiol 35 μg). Forty‐six healthy women were enrolled; 32 completed the study. After the lead‐in period (OC alone), 41 eligible participants were randomized 1:1 to sequence 1 (OC and DMF coadministration in period 1; OC alone in period 2) or sequence 2 (regimens reversed). Mean concentration profiles of plasma norelgestromin (primary metabolite of norgestimate) and ethinyl estradiol were superimposable following OC alone and OC coadministered with DMF, with 90% confidence intervals of geometric mean ratios for area under the plasma concentration–time curve over the dosing interval and peak plasma concentration contained within the 0.8–1.25 range. Low serum progesterone levels during combined treatment confirmed suppression of ovulation. The pharmacokinetics of DMF (measured via its primary active metabolite, monomethyl fumarate) were consistent with historical data when DMF was administered alone. No new safety concerns were identified. These results suggest that norgestimate/ethinyl estradiol–based OCs may be used with DMF without dose modification. PMID:28783872

Footwear contact dermatitis from dimethyl fumarate.

PubMed

Švecová, Danka; Šimaljakova, Maria; Doležalová, Anna

2013-07-01

Dimethyl fumarate (DMF) is an effective inhibitor of mold growth. In very low concentrations, DMF is a potent sensitizer that can cause severe allergic contact dermatitis (ACD). It has been identified as the agent responsible for furniture contact dermatitis in Europe. The aim of this study was to evaluate patients in Slovakia with footwear ACD associated with DMF, with regard to clinical manifestations, patch test results, and results of chemical analysis of their footwear. Nine patients with suspected footwear contact dermatitis underwent patch testing with the following allergens: samples of their own footwear, commercial DMF, the European baseline, shoe screening, textile and leather dye screening, and industrial biocides series. The results were recorded according to international guidelines. The content of DMF in footwear and anti-mold sachets was analyzed using gas chromatography and mass spectrometry. Acute ACD was observed in nine Caucasian female patients. All patients developed delayed sensitization, as demonstrated by positive patch testing using textile footwear lining. Seven patients were patch tested with 0.1% DMF, and all seven were positive. Chemical analysis of available footwear showed that DMF was present in very high concentrations (25-80 mg/Kg). Dimethyl fumarate is a new footwear allergen and was responsible for severe ACD in our patients. To avoid an increase in the number of cases, the already approved European preventive measures should be accepted and commonly employed. © 2013 The International Society of Dermatology.

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices

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

Jebrail, Mais J.; Renzi, Ronald F.; Sinha, Anupama

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate thatmore » this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4–95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. As a result, this simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.« less

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices

DOE PAGES

Jebrail, Mais J.; Renzi, Ronald F.; Sinha, Anupama; ...

2014-10-01

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate thatmore » this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4–95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. As a result, this simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.« less

[The effect of daily controlled oral hygiene on the oral health of children in a town with drinking water fluoridation (Karl Marx Stadt)].

PubMed

Georgi, J; Künzel, W

1976-03-01

Under the conditions of an optimized (with regard to caries prevention) fluoride content of the drinking uater, the authors studied (in the framework of an oral hygiene measure covering 32 months) in 149 children 6.5-8 years of age the effects of supervised daily dental and oral care on dental health. The improvement in oral hygiene (OHI) by 33% is in harmony with an additional caries reduction by 33.3% (DMF/S index) and a decrease of the PM index by 47%. A wider use of oral hygiene actions as secondary preventive measures is, therefore, recommended also for towns with fluoridated drinking water.

A practice-changing culture method relying on shaking substantially increases mitochondrial energy metabolism and functionality of human liver cell lines.

PubMed

Adam, Aziza A A; van der Mark, Vincent A; Donkers, Joanne M; Wildenberg, Manon E; Oude Elferink, Ronald P J; Chamuleau, Robert A F M; Hoekstra, Ruurdtje

2018-01-01

Practice-changing culturing techniques of hepatocytes are highly required to increase their differentiation. Previously, we found that human liver cell lines HepaRG and C3A acquire higher functionality and increased mitochondrial biogenesis when cultured in the AMC-Bioartificial liver (BAL). Dynamic medium flow (DMF) is one of the major contributors to this stimulatory effect. Recently, we found that DMF-culturing by shaking of HepaRG monolayers resulted in higher mitochondrial biogenesis. Here we further investigated the effect of DMF-culturing on energy metabolism and hepatic functionality of HepaRG and C3A monolayers. HepaRG and C3A DMF-monolayers were incubated with orbital shaking at 60 rpm during the differentiation phase, while control monolayers were maintained statically. Subsequently, energy metabolism and hepatic functionality were compared between static and DMF-cultures. DMF-culturing of HepaRG cells substantially increased hepatic differentiation; transcript levels of hepatic structural genes and hepatic transcription regulators were increased up to 15-fold (Cytochrome P450 3A4) and nuclear translocation of hepatic transcription factor CEBPα was stimulated. Accordingly, hepatic functions were positively affected, including ammonia elimination, urea production, bile acid production, and CYP3A4 activity. DMF-culturing shifted energy metabolism from aerobic glycolysis towards oxidative phosphorylation, as indicated by a decline in lactate production and glucose consumption, and an increase in oxygen consumption. Similarly, DMF-culturing increased mitochondrial energy metabolism and hepatic functionality of C3A cells. In conclusion, simple shaking of monolayer cultures substantially improves mitochondrial energy metabolism and hepatic differentiation of human liver cell lines. This practice-changing culture method may prove to prolong the in-vitro maintenance of primary hepatocytes and increase hepatic differentiation of stem cells.

Dimethyl Fumarate Selectively Reduces Memory T Cells and Shifts the Balance between Th1/Th17 and Th2 in Multiple Sclerosis Patients.

PubMed

Wu, Qi; Wang, Qin; Mao, Guangmei; Dowling, Catherine A; Lundy, Steven K; Mao-Draayer, Yang

2017-04-15

Dimethyl fumarate (DMF; trade name Tecfidera) is an oral formulation of the fumaric acid ester that is Food and Drug Administration approved for treatment of relapsing-remitting multiple sclerosis. To better understand the therapeutic effects of Tecfidera and its rare side effect of progressive multifocal leukoencephalopathy, we conducted cross-sectional and longitudinal studies by immunophenotyping cells from peripheral blood (particularly T lymphocytes) derived from untreated and 4-6 and 18-26 mo Tecfidera-treated stable relapsing-remitting multiple sclerosis patients using multiparametric flow cytometry. The absolute numbers of CD4 and CD8 T cells were significantly decreased and the CD4/CD8 ratio was increased with DMF treatment. The proportions of both effector memory T cells and central memory T cells were reduced, whereas naive T cells increased in treated patients. T cell activation was reduced with DMF treatment, especially among effector memory T cells and effector memory RA T cells. Th subsets Th1 (CXCR3 + ), Th17 (CCR6 + ), and particularly those expressing both CXCR3 and CD161 were reduced most significantly, whereas the anti-inflammatory Th2 subset (CCR3 + ) was increased after DMF treatment. A corresponding increase in IL-4 and decrease in IFN-γ and IL-17-expressing CD4 + T cells were observed in DMF-treated patients. DMF in vitro treatment also led to increased T cell apoptosis and decreased activation, proliferation, reactive oxygen species, and CCR7 expression. Our results suggest that DMF acts on specific memory and effector T cell subsets by limiting their survival, proliferation, activation, and cytokine production. Monitoring these subsets could help to evaluate the efficacy and safety of DMF treatment. Copyright © 2017 by The American Association of Immunologists, Inc.

Dimethyl Fumarate Protects Neural Stem/Progenitor Cells and Neurons from Oxidative Damage through Nrf2-ERK1/2 MAPK Pathway.

PubMed

Wang, Qin; Chuikov, Sergei; Taitano, Sophina; Wu, Qi; Rastogi, Arjun; Tuck, Samuel J; Corey, Joseph M; Lundy, Steven K; Mao-Draayer, Yang

2015-06-17

Multiple sclerosis (MS) is the most common multifocal inflammatory demyelinating disease of the central nervous system (CNS). Due to the progressive neurodegenerative nature of MS, developing treatments that exhibit direct neuroprotective effects are needed. Tecfidera™ (BG-12) is an oral formulation of the fumaric acid esters (FAE), containing the active metabolite dimethyl fumarate (DMF). Although BG-12 showed remarkable efficacy in lowering relapse rates in clinical trials, its mechanism of action in MS is not yet well understood. In this study, we reported the potential neuroprotective effects of dimethyl fumarate (DMF) on mouse and rat neural stem/progenitor cells (NPCs) and neurons. We found that DMF increased the frequency of the multipotent neurospheres and the survival of NPCs following oxidative stress with hydrogen peroxide (H2O2) treatment. In addition, utilizing the reactive oxygen species (ROS) assay, we showed that DMF reduced ROS production induced by H2O2. DMF also decreased oxidative stress-induced apoptosis. Using motor neuron survival assay, DMF significantly promoted survival of motor neurons under oxidative stress. We further analyzed the expression of oxidative stress-induced genes in the NPC cultures and showed that DMF increased the expression of transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) at both levels of RNA and protein. Furthermore, we demonstrated the involvement of Nrf2-ERK1/2 MAPK pathway in DMF-mediated neuroprotection. Finally, we utilized SuperArray gene screen technology to identify additional anti-oxidative stress genes (Gstp1, Sod2, Nqo1, Srxn1, Fth1). Our data suggests that analysis of anti-oxidative stress mechanisms may yield further insights into new targets for treatment of multiple sclerosis (MS).

How the guest molecules in nanoporous Zn(II) metal-organic framework can prevent agglomeration of ZnO nanoparticles

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

Moeinian, Maryam; Akhbari, Kamran, E-mail: akhbari.k@khayam.ut.ac.ir

The host and the apohost framework of [Zn{sub 2}(BDC){sub 2}(H{sub 2}O){sub 2}·(DMF){sub 2}]{sub n} (1·2H{sub 2}O·2DMF), (BDC{sup 2−}=benzene-1,4-dicarboxylate and DMF=N,N-Dimethylformamide), were synthesized and subsequently used for preparation of ZnO nanomaterials. With calcination of the host framework of 1·2H{sub 2}O·2DMF, ZnO nanoparticles were obtained. By the same process on the apohost framework of 1, agglomerated nanoparticles of ZnO were formed. These nano-structures were characterized by X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM). These results indicate that with removal of the guest DMF and coordinated H{sub 2}O molecules from the one-dimensional channels of 1·2H{sub 2}O·2DMF, the tendency of nanoparticles tomore » agglomerate increases and the role of this MOF in preparation of ZnO nanoparticles from this precursor was reduced. - Graphical abstract: Nano-porous zinc(II) MOF with guest DMF and coordinated H{sub 2}O molecules has been synthesized and characterized. The host and the apohost framework of it were used for preparation of ZnO nanomaterials. The role of these species in preparation of ZnO nanoparticles from the host framework is probably similar to the role of polymeric stabilizers in formation of nanoparticles. - Highlights: • Nanoparticles of ZnO were fabricated from nanoporous metal-organic framework. • The effect of guest DMF and coordinated H{sub 2}O molecules on this process was studied. • The effect of them in formation nanoparticle is similar to polymeric stabilizers.« less

Dimethyl Fumarate Protects Neural Stem/Progenitor Cells and Neurons from Oxidative Damage through Nrf2-ERK1/2 MAPK Pathway

PubMed Central

Wang, Qin; Chuikov, Sergei; Taitano, Sophina; Wu, Qi; Rastogi, Arjun; Tuck, Samuel J.; Corey, Joseph M.; Lundy, Steven K.; Mao-Draayer, Yang

2015-01-01

Multiple sclerosis (MS) is the most common multifocal inflammatory demyelinating disease of the central nervous system (CNS). Due to the progressive neurodegenerative nature of MS, developing treatments that exhibit direct neuroprotective effects are needed. Tecfidera™ (BG-12) is an oral formulation of the fumaric acid esters (FAE), containing the active metabolite dimethyl fumarate (DMF). Although BG-12 showed remarkable efficacy in lowering relapse rates in clinical trials, its mechanism of action in MS is not yet well understood. In this study, we reported the potential neuroprotective effects of dimethyl fumarate (DMF) on mouse and rat neural stem/progenitor cells (NPCs) and neurons. We found that DMF increased the frequency of the multipotent neurospheres and the survival of NPCs following oxidative stress with hydrogen peroxide (H2O2) treatment. In addition, utilizing the reactive oxygen species (ROS) assay, we showed that DMF reduced ROS production induced by H2O2. DMF also decreased oxidative stress-induced apoptosis. Using motor neuron survival assay, DMF significantly promoted survival of motor neurons under oxidative stress. We further analyzed the expression of oxidative stress-induced genes in the NPC cultures and showed that DMF increased the expression of transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) at both levels of RNA and protein. Furthermore, we demonstrated the involvement of Nrf2-ERK1/2 MAPK pathway in DMF-mediated neuroprotection. Finally, we utilized SuperArray gene screen technology to identify additional anti-oxidative stress genes (Gstp1, Sod2, Nqo1, Srxn1, Fth1). Our data suggests that analysis of anti-oxidative stress mechanisms may yield further insights into new targets for treatment of multiple sclerosis (MS). PMID:26090715

Effects of delayed-release dimethyl fumarate on MRI measures in the phase 3 CONFIRM study.

PubMed

Miller, David H; Fox, Robert J; Phillips, J Theodore; Hutchinson, Michael; Havrdova, Eva; Kita, Mariko; Wheeler-Kingshott, Claudia A M; Tozer, Daniel J; MacManus, David G; Yousry, Tarek A; Goodsell, Mary; Yang, Minhua; Zhang, Ray; Viglietta, Vissia; Dawson, Katherine T

2015-03-17

To evaluate the effects of oral delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) on MRI lesion activity and load, atrophy, and magnetization transfer ratio (MTR) measures from the Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis (CONFIRM) study. CONFIRM was a 2-year, placebo-controlled study of the efficacy and safety of DMF 240 mg twice (BID) or 3 times daily (TID) in 1,417 patients with relapsing-remitting multiple sclerosis (RRMS); subcutaneous glatiramer acetate 20 mg once daily was included as an active reference comparator. The number and volume of T2-hyperintense, T1-hypointense, and gadolinium-enhancing (Gd+) lesions, as well as whole brain volume and MTR, were assessed in 681 patients (MRI cohort). DMF BID and TID produced significant and consistent reductions vs placebo in the number of new or enlarging T2-hyperintense lesions and new nonenhancing T1-hypointense lesions after 1 and 2 years of treatment and in the number of Gd+ lesions at week 24, year 1, and year 2. Lesion volumes were also significantly reduced. Reductions in brain atrophy and MTR changes with DMF relative to placebo did not reach statistical significance. The robust effects on MRI active lesion counts and total lesion volume in patients with RRMS demonstrate the ability of DMF to exert beneficial effects on inflammatory lesion activity in multiple sclerosis, and support DMF therapy as a valuable new treatment option in RRMS. This study provides Class I evidence of reduction in brain lesion number and volume, as assessed by MRI, over 2 years of delayed-release DMF treatment. © 2015 American Academy of Neurology.

Dimethylfumarate induces cell cycle arrest and apoptosis via regulating intracellular redox systems in HeLa cells.

PubMed

Han, Guocan; Zhou, Qiang

2016-12-01

Dimethylfumarate (DMF) is cytotoxic to several kinds of cells and serves as an anti-tumor drug. This study was designed to investigate the effects and underlying mechanism of DMF on cervical cancer cells. HeLa cells were cultured and treated with 0, 50, 100, 150, and 200 μM DMF, respectively. After 24 h, cell growth was evaluated using Cell Counting Kit-8 (CCK-8) assay and the cell cycle was examined using flow cytometry. In addition, cell apoptosis was detected by Annexin V/propidium iodide (PI) staining and the expressions of caspase-3 and poly-ADP-ribose polymerase (PARP) were detected using western blotting. The redox-related factors were then assessed. Furthermore, all of the indicators were detected in HeLa cells after combined treatment of DMF and N-acetyl-L-cysteine (NAC, an oxygen-free radical scavenger). The cell number and cell growth of HeLa were obviously inhibited by DMF in a dose-dependent manner, as the cell cycle was arrested at G0/G1 phase (P < 0.05). The apoptotic HeLa cells were markedly increased, and the expression levels of caspase-3 and PARP were significantly increased in a DMF concentration-dependent way (P < 0.05). Meanwhile, loss of △Ψm, increase in reactive oxygen species and O 2 ·- , and the decrease in catalase activity and glutathione (GSH) level were found after DMF treatment (P < 0.05). All these changes were significantly attenuated and even completely disappeared by adding NAC (P < 0.05). In conclusion, the cytotoxicity of DMF on cell proliferation and apoptosis of HeLa cells was mainly related to the intracellular redox systems by depletion of intracellular GSH.

The impact of the new scene drug "crystal meth" on oral health: a case-control study.

PubMed

Rommel, Niklas; Rohleder, Nils H; Wagenpfeil, Stefan; Härtel-Petri, Roland; Jacob, Frederic; Wolff, Klaus-Dietrich; Kesting, Marco R

2016-04-01

The use of methamphetamine (MA), a highly addictive stimulant, is rapidly increasing, with MA being widely abused as the scene drug "Crystal Meth" (CM). CM has been associated with severe oral health effects, resulting in so-called "Meth mouth". This term appeared for the first time in 2005 in the literature and describes the final complex of symptoms including rampant caries, periodontal diseases and excessive tooth wear. The aim of this study was to investigate the effects of chronic CM abuse on teeth and intraoral tissue with respect to potential symptoms of Meth mouth. In cooperation with two centres for addiction medicine, we performed clinical intraoral investigations in 100 chronic CM users and 100 matched-pair controls. We undertook a caries and periodontal examination by using the clinical parameters DMF-T/DMF-S, bleeding on probing index (BOP) and periodontal screening index (PSI) and tested individual oral hygiene by using approximal space plaque index (API). All clinical data were analysed by the t test for independent samples. We found significantly larger numbers of caries (p < 0.001) and higher levels of gingival bleeding (p < 0.001) and periodontal disease (p < 0.001) among CM users. Oral hygiene was significantly lower in CM users (p < 0.024). Chronic CM use can lead to extensive potential damage within the intraoral cavity. When CM is used over a long period of time and in the absence of treatment, clinical symptoms in terms of Meth mouth syndrome cannot be excluded. Based on our results, we recommend a specific prevention and therapeutic concept including educational campaigns for MA users and specialized dental care for CM patients.

[Oral health in young adults in Germany--a comparison between women and men of the German army].

PubMed

Ziebolz, Dirk; Schwerdtfeger, Bernd; Brunner, Edgar; Hornecker, Else; Mausberg, Rainer F

2008-01-01

The objective of this cross-sectional study was to compare oral health in young German women and men. We paired female and male soldiers of the German armed force (Bundeswehr) on the basis of age, school qualification and origin. All participants underwent a clinical examination. Oral health was assessed using the decayed, missing and filled surfaces index (DMF-S), an oral hygiene index (QHI), and a periodontal index (CPITN). In addition, we collected data on the subjects' smoking habits. The study included 90 women (mean age: 21.7 years) and 90 men (mean age: 21.4 years). The mean DMF-S was 20.7 +/- 13.7 for women and 21.0 +/- 19.8 for men (p>0.05). In the female group, dental restorations were present in 71% of the teeth affected by caries. In the male group, restorations were present in 61.2% (p=0.04). The female group showed a less marked polarisation of caries than the male group (p=0.03). Oral hygiene (QHI) was poor in the entire study population. Women (QHI: 2.16 +/- 0.6), however, exhibited significantly better oral hygiene than men (QHI: 2.53 +/- 0.5) (p= 0.01). Deeper probing depths (CPITN scores of 3 and 4) were less frequently seen in females than in males (p= 0.04). In both groups more than half of the participants were smokers (56.7%) since at least four years with more than ten cigarettes per day. Smoking had a significant influence on periodontal health (p=0.02). Men showed poorer oral health than women. The study emphasizes that the proportion of young adults requiring curative dental treatment remains high in Germany. It also underlines the need for intensive preventive care including cessation of smoking.

Synthesis of Large-Pore Stabilized MIL-53(Al) Compounds with Increased CO2 Adsorption and Decreased Water Adsorption

DTIC Science & Technology

2014-01-01

increase in the quadrupolar coupling constant upon saturation with DMF for sDMF220, 8.4~10.1, and sDMF120, 8.2~10.1 compared to the increase in CQ...nonpolar methane . The CH4 adsorption isotherms for sH2O and sDMF220 shown in Fig. 5 also exhibit Type I behaviour. The CO2 adsorption isotherm for sH2O...Am. Chem. Soc., 2002, 124, 13519-13526. 15. T. Loiseau, C. Serre, C. Huguenard, G. Fink, F. Taulelle, M. Henry , T. Bataille and G. Ferey, Chem-Eur J

Combination of dacarbazine and dimethylfumarate efficiently reduces melanoma lymph node metastasis.

PubMed

Valero, Teresa; Steele, Silvia; Neumüller, Karin; Bracher, Andreas; Niederleithner, Heide; Pehamberger, Hubert; Petzelbauer, Peter; Loewe, Robert

2010-04-01

Dimethylfumarate (DMF) has been shown to reduce melanoma growth and metastasis in animal models. We addressed the question of whether DMF is as effective in its antitumor activity as the US Food and Drug Administration-approved alkylating agent dacarbazine (DTIC). We also tested the possibility of an improved antitumoral effect when both therapeutics were used together. Using our severe combined immunodeficiency (SCID) mouse model, in which xenografted human melanoma cells metastasize from primary skin sites to sentinel nodes, we show that these treatments, alone or in combination, reduce tumor growth at primary sites. Our main finding was that metastasis to sentinel nodes is significantly delayed only in mice treated with a combination of DTIC and DMF. Subsequent experiments were able to show that a combination of DTIC/DMF significantly reduced lymph vessel density in primary tumors as examined by real-time PCR and immunohistochemistry. In addition, DTIC/DMF treatment significantly impaired melanoma cell migration in vitro. In vivo, DTIC/DMF therapy significantly reduced mRNA expression and protein concentration of the promigratory chemokines CXCL2 and CXCL11. In addition, our data suggest that this xenotransplantation model is suitable for preclinical testing of various combinations of antimelanoma agents.

Short-term exposure to dimethylformamide and the impact on digestive system disease: an outdoor study for volatile organic compound.

PubMed

Wang, Cui; Huang, Canke; Wei, Yumei; Zhu, Qi; Tian, Weili; Zhang, Qingyu

2014-07-01

Occupational and experimental studies have revealed the organs most affected by dimethylformamide (DMF) are liver and gastrointestinal tract. However, few studies have focused on the potential effect of outdoor pollution of DMF. This study examined the health risk of hospitalization due to digestive system disease by time series studies in a case city Longwan, China. The urine metabolite of DMF was correlated well with DMF exposure concentration (EC). A 101.0-μg/m(3) (interquartile range) increase in the two-day moving average of DMF EC was associated with a 1.10 (1.01 ˜ 1.20), 1.22 (1.10 ˜ 1.35), and 1.05 (0.90 ˜ 1.22) increase in hospitalization for total digestive system diseases, liver disease, and gastrointestinal tract disease, respectively. The exposure-dose response between DMF and the relative risk of liver disease was linear only below 350 μg/m(3). These findings highlight a previously unrecognized health problem related to VOCs released into the outdoor environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preclinical Explorative Assessment of Dimethyl Fumarate-Based Biocompatible Nanolipoidal Carriers for the Management of Multiple Sclerosis.

PubMed

Kumar, Pramod; Sharma, Gajanand; Gupta, Varun; Kaur, Ramanpreet; Thakur, Kanika; Malik, Ruchi; Kumar, Anil; Kaushal, Naveen; Raza, Kaisar

2018-05-16

Multiple sclerosis (MS) is a neurodegenerative disease in which myelin sheath damage occurs due to internal and external factors. MS especially affects the young population. Dimethyl fumarate (DMF) is a promising agent for MS treatment, although it is associated with concerns such as poor brain permeation, multiple dosing, and gastrointestinal flushing. The present study attempts to evaluate the preclinical performance of specially designed DMF-based lipoidal nanoparticles in a cuprizone-induced demyelination model in rodents. The studies proved the efficacy of lipid-based nanoparticles containing DMF in a once-a-day dosage regimen over that of thrice-a-day plain DMF administration on crucial parameters like motor coordination, grip strength, mortality, body weight, and locomotor activity. However, neither blank lipid nor blank neuroprotective (vitamins A, D, and E) loaded nanoparticles were able to elicit any desirable behavioral response. Histopathological studies showed that the designed once-a-day DMF nanomedicines were well tolerated and rejuvenated the myelin sheath vis-à-vis the plain DMF thrice-a-day regimen. These findings provide proof of concept for a biocompatible nanomedicine for MS with tremendous promise for effective brain delivery and patient compliance on the grounds of a reduction in the dosage frequency.

The effect of social demographic factors, snack consumption and vending machine use on oral health of children living in London.

PubMed

Maliderou, M; Reeves, S; Noble, C

2006-10-07

To investigate the effect of socio-economic status, sugar, snack consumption and vending machine use on the prevalence and severity of caries (DMF) in children. An observational study was carried out in a dental practice in inner city London. Sixty children were asked to complete a questionnaire and a three day food and drink diary. After a dental examination the number of decayed (D), missing (M) or filled (F) teeth provided a DMF score. Anova and Pearsons correlations were used to analyse the data statistically. Children from social groups I and II consumed significantly less (P < 0.05) sugar, confectionery, crisps and used a vending machine less often than children from other social groups. Children from Social groups I, II and III had significantly lower DMF scores. The average DMF from social group I children was 0.5 +/- 0.6, whilst group IV children had the greatest incidence and a DMF of 4.6 +/- 0.8. Significant correlations were identified between DMF and sugar, confectionery and crisp consumption and vending machine use, and a negative correlation between DMF and vegetable consumption. Socio-economic status and access to vending machines were found to have a significant effect on sugar intakes, foods choices, and dental health. The removal of vending machines from schools or at least installing 'healthy' vending machines is recommended. Health promotion programmes that account for social groups and snacking habits that are cost effective are required.

Evaluation of Potential Drug-Drug Interaction Between Delayed-Release Dimethyl Fumarate and a Commonly Used Oral Contraceptive (Norgestimate/Ethinyl Estradiol) in Healthy Women.

PubMed

Zhu, Bing; Nestorov, Ivan; Zhao, Guolin; Meka, Venkata; Leahy, Mark; Kam, Jeanelle; Sheikh, Sarah I

2017-11-01

Delayed-release dimethyl fumarate (DMF) is an oral therapy for relapsing multiple sclerosis with anti-inflammatory and neuroprotective properties. This 2-period crossover study was conducted to evaluate the potential for drug-drug interaction between DMF (240 mg twice daily) and a combined oral contraceptive (OC; norgestimate 250 μg, ethinyl estradiol 35 μg). Forty-six healthy women were enrolled; 32 completed the study. After the lead-in period (OC alone), 41 eligible participants were randomized 1:1 to sequence 1 (OC and DMF coadministration in period 1; OC alone in period 2) or sequence 2 (regimens reversed). Mean concentration profiles of plasma norelgestromin (primary metabolite of norgestimate) and ethinyl estradiol were superimposable following OC alone and OC coadministered with DMF, with 90% confidence intervals of geometric mean ratios for area under the plasma concentration-time curve over the dosing interval and peak plasma concentration contained within the 0.8-1.25 range. Low serum progesterone levels during combined treatment confirmed suppression of ovulation. The pharmacokinetics of DMF (measured via its primary active metabolite, monomethyl fumarate) were consistent with historical data when DMF was administered alone. No new safety concerns were identified. These results suggest that norgestimate/ethinyl estradiol-based OCs may be used with DMF without dose modification. © 2017, The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.

Relapse outcomes, safety, and treatment patterns in patients diagnosed with relapsing-remitting multiple sclerosis and initiated on subcutaneous interferon β-1a or dimethyl fumarate: a real-world study.

PubMed

Ernst, Frank R; Barr, Peri; Elmor, Riad; Wong, Schiffon L

2017-12-01

To estimate real-world treatment patterns, safety, and relapse outcomes of subcutaneous (sc) interferon (IFN) β-1a (Rebif) vs dimethyl fumarate (DMF; Tecfidera), to treat relapsing-remitting multiple sclerosis (RRMS). A US retrospective chart review of 450 randomly selected adults newly diagnosed with RRMS who received sc IFN β-1a (n = 143) or DMF (n = 307) was conducted. Patients were either (a) treatment-naïve, initiating first-line treatment with sc IFN β-1a or DMF, or (b) previously treated, switching to sc IFN β-1a or DMF. Two years' follow-up data were captured. Patient characteristics, persistence, and adverse events between treatment groups were compared using t-tests or Chi-square tests. Kaplan-Meier curves with log-rank tests and Cox proportional hazards models were used to compare time to, and risk of non-persistence. Annualized Relapse Rates (ARR) were calculated using a robust variance Poisson model adjusting for covariates. Propensity scores were used to address possible selection bias. One hundred and twelve patients became non-persistent, most commonly due to an adverse event (n = 37). No difference was observed in time to overall non-persistence between sc IFN β-1a and DMF patients. Among treatment-naïve patients, those receiving DMF had 2.4-times the risk (HR = 2.439, 95% CI = 1.007-5.917, p = .0483) of experiencing a discontinuation than patients receiving sc IFN β-1a. Non-persistent patients receiving DMF had 2.3-times the risk (HR = 2.311, 95% CI = 1.350-3.958, p = .0023) of experiencing an adverse event at a given time point than patients prescribed sc IFN β-1a. No differences in relapse risk or ARR between sc IFN β-1a- and DMF-treated patients were observed. sc IFN β-1a-treated patients had comparable persistence and relapse outcomes, and better safety outcomes vs DMF-treated patients across 2 years.

Distinct Nrf2 Signaling Mechanisms of Fumaric Acid Esters and Their Role in Neuroprotection against 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Experimental Parkinson's-Like Disease.

PubMed

Ahuja, Manuj; Ammal Kaidery, Navneet; Yang, Lichuan; Calingasan, Noel; Smirnova, Natalya; Gaisin, Arsen; Gaisina, Irina N; Gazaryan, Irina; Hushpulian, Dmitry M; Kaddour-Djebbar, Ismail; Bollag, Wendy B; Morgan, John C; Ratan, Rajiv R; Starkov, Anatoly A; Beal, M Flint; Thomas, Bobby

2016-06-08

A promising approach to neurotherapeutics involves activating the nuclear-factor-E2-related factor 2 (Nrf2)/antioxidant response element signaling, which regulates expression of antioxidant, anti-inflammatory, and cytoprotective genes. Tecfidera, a putative Nrf2 activator, is an oral formulation of dimethylfumarate (DMF) used to treat multiple sclerosis. We compared the effects of DMF and its bioactive metabolite monomethylfumarate (MMF) on Nrf2 signaling and their ability to block 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced experimental Parkinson's disease (PD). We show that in vitro DMF and MMF activate the Nrf2 pathway via S-alkylation of the Nrf2 inhibitor Keap1 and by causing nuclear exit of the Nrf2 repressor Bach1. Nrf2 activation by DMF but not MMF was associated with depletion of glutathione, decreased cell viability, and inhibition of mitochondrial oxygen consumption and glycolysis rates in a dose-dependent manner, whereas MMF increased these activities in vitro However, both DMF and MMF upregulated mitochondrial biogenesis in vitro in an Nrf2-dependent manner. Despite the in vitro differences, both DMF and MMF exerted similar neuroprotective effects and blocked MPTP neurotoxicity in wild-type but not in Nrf2 null mice. Our data suggest that DMF and MMF exhibit neuroprotective effects against MPTP neurotoxicity because of their distinct Nrf2-mediated antioxidant, anti-inflammatory, and mitochondrial functional/biogenetic effects, but MMF does so without depleting glutathione and inhibiting mitochondrial and glycolytic functions. Given that oxidative damage, neuroinflammation, and mitochondrial dysfunction are all implicated in PD pathogenesis, our results provide preclinical evidence for the development of MMF rather than DMF as a novel PD therapeutic. Almost two centuries since its first description by James Parkinson, Parkinson's disease (PD) remains an incurable disease with limited symptomatic treatment. The current study provides preclinical evidence that a Food and Drug Administration-approved drug, dimethylfumarate (DMF), and its metabolite monomethylfumarate (MMF) can block nigrostriatal dopaminergic neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD. We elucidated mechanisms by which DMF and its active metabolite MMF activates the redox-sensitive transcription factor nuclear-factor-E2-related factor 2 (Nrf2) to upregulate antioxidant, anti-inflammatory, mitochondrial biosynthetic and cytoprotective genes to render neuroprotection via distinct S-alkylating properties and depletion of glutathione. Our data suggest that targeting Nrf2-mediated gene transcription using MMF rather than DMF is a promising approach to block oxidative stress, neuroinflammation, and mitochondrial dysfunction for therapeutic intervention in PD while minimizing side effects. Copyright © 2016 the authors 0270-6474/16/366333-20$15.00/0.

A Self-Binding, Melt-Castable, Crystalline Organic Electrolyte for Sodium Ion Conduction.

PubMed

Chinnam, Parameswara Rao; Fall, Birane; Dikin, Dmitriy A; Jalil, AbdelAziz; Hamilton, Clifton R; Wunder, Stephanie L; Zdilla, Michael J

2016-12-05

The preparation and characterization of the cocrystalline solid-organic sodium ion electrolyte NaClO 4 (DMF) 3 (DMF=dimethylformamide) is described. The crystal structure of NaClO 4 (DMF) 3 reveals parallel channels of Na + and ClO 4 - ions. Pressed pellets of microcrystalline NaClO 4 (DMF) 3 exhibit a conductivity of 3×10 -4  S cm -1 at room temperature with a low activation barrier to conduction of 25 kJ mol -1 . SEM revealed thin liquid interfacial contacts between crystalline grains, which promote conductivity. The material melts gradually between 55-65 °C, but does not decompose, and upon cooling, it resolidifies as solid NaClO 4 (DMF) 3 , permitting melt casting of the electrolyte into thin films and the fabrication of cells in the liquid state and ensuring penetration of the electrolyte between the electrode active particles. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dimethyl fumarate contact dermatitis of the foot: an increasingly widespread disease.

PubMed

D'Erme, Angelo Massimiliano; Bassi, Andrea; Lotti, Torello; Gola, Massimo

2012-01-01

Dimethyl fumarate (DMF) has been recognized as an extremely potent irritant and sensitizer found in sachets inside furniture. The first skin manifestations were correlated to contact with sofas, chairs, and other furniture. In these last years, some papers have reported a development of allergic contact dermatitis on the foot caused by DMF present in high concentration in shoes made in China. We report the case of a 37-year-old woman who presented with severe eczema on the foot shortly after having bought a new pair of shoes. The diagnosis was performed by patch tests with DMF in several dilutions, with pieces of internal and external parts of the shoes, and by chemical analysis of the shoes. In the last three years, goods containing DMF increased diffusely despite the augmentation on global preventive measures by Europe. Therefore, new cases of contact dermatitis could be dependent on DMF, and it is of note that this allergen is not included in most series for patch testing. © 2011 The International Society of Dermatology.

General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

NASA Astrophysics Data System (ADS)

Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

2016-11-01

A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities.

General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

PubMed Central

Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

2016-01-01

A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities. PMID:27853187

Synthesis of High-Impact Polystyrene Fibers using Electrospinning

NASA Astrophysics Data System (ADS)

Zulfi, A.; Fauzi, A.; Edikresnha, D.; Munir, M. M.; Khairurrijal

2017-05-01

Synthesis of fibers from waste high-impact polystyrene (HIPS) have been successfully done using electrospinning method. The HIPS solutions were made with a single solvent (DMF or d-limonene), a mixed solvent (d-limonene/DMF), and with the addition of acetone to the previously stated solvents. The effects of HIPS concentration, a mix of solvent, and the addition of acetone on the morphology and the diameter of fibers were observed. The morphological change from particles to fibers took place along with the increasing concentration of HIPS in d-limonene. For other precursor solutions using DMF solvent, bead free fibers could be obtained even at low levels. The average diameter of fibers increased along with the increase of the HIPS concentration in DMF. At the concentrations of 15, 20, 25, 30, and 35 wt.%, the average diameters were 1.85, 2.09, 2.66, 3.59, and 7.38 μm, respectively. For the precursor solutions with the combination of different solvents (HIPS/DMF), the existence of beads was influenced by the ratio of solvents. When the ratio of d-limonene/DMF was 75:25, the obtained beaded fibers had a relatively large amount of beads. At the ratio of 50:50, fewer beads were found. Bead-free fibers were finally reached when the ratio of HIPS / DMF was 25:75. The addition of acetone reduced the diameter of the produced fibers. However, too much addition of acetone caused the fibers to be wet. Additionally, the diameter became larger if the addition of acetone surpassed a certain amount of volume.

Synthesis and Cell Imaging of a Near-Infrared Fluorescent Magnetic "CdHgTe-Dextran-Magnetic Layered Double Hydroxide-Fluorouracil" Composite.

PubMed

Jin, XueQin; Zhang, Min; Gou, GuoJing; Ren, Jie

2016-05-01

In this article, a water-soluble near-infrared quantum dots of CdHgTe were prepared and subsequently combined with the drug delivery system "dextran-magnetic layered double hydroxide-fluorouracil" (DMF) to build a new nanostructure platform in form of CdHgTe@DMF, in which the fluorescent probe function of quantum dots and the magnetic targeting transport and slow-release curative effect of DMF were blended availably together. The luminescent property particle size, and internal structure of the composite were characterized using fluorescence spectrophotometer, ultraviolet spectrophotometer, laser particle size distribution, TEM, X-ray diffraction, and Fourier transform infrared. The experimental study on fluorescent tags effect and magnetic targeting performance of the multifunctional platform were performed by fluorescent confocal imaging. The results showed that the CdHgTe could be grafted successfully onto the surface of DMF by electrostatic coupling. The CdHgTe@DMF composite showed super-paramagnetic and photoluminescence property in the near-infrared wavelength range of 575-780 nm. Compared with CdHgTe, the CdHgTe@DMF composite could significantly improve the cell imaging effect, the label intensity increased with the magnetic field intensity, and obeyed the linear relationship Dmean = 1.758 + 0.0075M under the conditions of magnetic field interference. It can be implied that the CdHgTe@DMF may be an effective multifunction tool applying to optical bioimaging and magnetic targeted therapy. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Photomagnetic switching of heterometallic complexes [M(dmf)4(H2O)3(mu-CN)Fe(CN)5].H2O (M=Nd, La, Gd, Y) analyzed by single-crystal X-ray diffraction and ab initio theory.

PubMed

Svendsen, Helle; Overgaard, Jacob; Chevallier, Marie A; Collet, Eric; Chen, Yu-Sheng; Jensen, Frank; Iversen, Bo B

2010-06-25

Single-crystal X-ray diffraction measurements have been carried out on [Nd(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (1; dmf=dimethylformamide), [Nd(dmf)(4)(H(2)O)(3)(mu-CN)Co(CN)(5)].H(2)O (2), [La(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (3), [Gd(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (4), and [Y(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (5), at 15(2) K with and without UV illumination of the crystals. Significant changes in unit-cell parameters were observed for all the iron-containing complexes, whereas 2 showed no response to UV illumination. Photoexcited crystal structures have been determined for 1, 3, and 4 based on refinements of two-conformer models, and excited-state occupancies of 78.6(1), 84(6), and 86.6(7)% were reached, respectively. Significant bond-length changes were observed for the Fe-ligand bonds (up to 0.19 A), the cyano bonds (up to 0.09 A), and the lanthanide-ligand bonds (up to 0.10 A). Ab initio theoretical calculations were carried out for the experimental ground-state geometry of 1 to understand the electronic structure changes upon UV illumination. The calculations suggest that UV illumination gives a charge transfer from the cyano groups on the iron atom to the lanthanide ion moiety, {Nd(dmf)(4)(H(2)O)(3)}, with a distance of approximately 6 A from the iron atom. The charge transfer is accompanied by a reorganization of the spin state on the {Fe(CN)(6)} complex, and a change in geometry that produces a metastable charge-transfer state with an increased number of unpaired electrons, thus accounting for the observed photomagnetic effect.

Cryopreservation of stallion spermatozoa using different cryoprotectants and combinations of cryoprotectants.

PubMed

Wu, Zhuangyuan; Zheng, Xinbiao; Luo, Yongming; Huo, Fei; Dong, Hong; Zhang, Guoting; Yu, Weihao; Tian, Fang; He, Liangjun; Chen, Jingbo

2015-12-01

The present study investigates the effects of five cryoprotectants (CPAs) and cryoprotectant combinations on the post-thaw total motility, progressive motility, viability, mitochondrial membrane potential and acrosome integrity in stallion spermatozoa. In Experiment 1, the objective was to compare the impact of different concentrations (2.5%, 3.5% and 5%) of a single CPA, including glycerol (Gly), ethylene glycol (EG), dimethyl sulphoxide (DMSO), methyl formamide (MF), and dimethylformamide (DMF) for stallion spermatozoa cryopreservation. In Experiment 2, two or more CPAs were used to assess whether this improved post-thaw spermatozoa quality. Gly, MF and DMF, were used to prepare seven combinations of freezing extender with different mixtures of cryoprotectant, and the 3.5% Gly, MF and DMF were used as a control group. The results show that post-thaw total motility, progressive motility, viability, and mitochondrial membrane potential for all concentrations of EG and DMSO were less than the 3.5% and 5% Gly and MF and 2.5% and 3.5% DMF (P<0.05). Use of the 3.5% concentration resulted in the greater post-thaw total motility and progressive motility than the 2.5% and 5% concentrations for all CPAs. The results for the use of different combinations of cryoprotectant indicate there are differences in progressive motility and viability. The viability with the use of Gly(2/3)+MF(1/3) was 44.65% and was greater than the Gly(1/3)+MF(1/3)+DMF(1/3) (30.96%), MF(2/3)+DMF(1/3) (35.05%), Gly (32.21%) and MF(33.76%) (P<0.05). The progressive motility with the use of the MF(2/3)+Gly(1/3) combination was 36.0% and was greater than in the DMF (25.0%) and MF(2/3)+DMF(1/3) (22.7%) (P<0.05). These results suggest that using the appropriate cryoprotectant combination instead of a single cryoprotectant can improve horse spermatozoa cryopreservation. Copyright © 2015 Elsevier B.V. All rights reserved.

Self-assembly of metal-organic supramolecules: from a metallamacrocycle and a metal-organic coordination cage to 1D or 2D coordination polymers based on flexible dicarboxylate ligands.

PubMed

Dai, Fangna; Dou, Jianmin; He, Haiyan; Zhao, Xiaoliang; Sun, Daofeng

2010-05-03

To assemble metal-organic supramolecules such as a metallamacrocycle and metal-organic coordination cage (MOCC), a series of flexible dicarboxylate ligands with the appropriate angle, 2,2'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(1)), 2,2'-(2,5-dimethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(2)), 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dinicotinic acid (H(2)L(3)), and 2,2'-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H(2)L(4)), have been designed and synthesized. Using these flexible ligands to assemble with metal ions, six metal-organic supramolecules, Cd(2)(L(1))(2)(dmf)(4)(H(2)O)(2).H(2)O (1), Mn(3)((1)L(2))(2)((2)L(2))(dmf)(2)(H(2)O)(2).5dmf (2), Cu(4)(L(3))(4)(H(2)O)(4).3dmf (3), Cu(4)(L(4))(4)(dmf)(2)(EtOH)(2).8dmf.6H(2)O (4), Mn(4)(L(4))(4)(dmf)(4)(H(2)O)(4).6dmf.H(2)O (5), and Mn(3)(L(4))(3)(dmf)(4).2dmf.3H(2)O (6), possessing a rectangular macrocycle, MOCCs or their extensions, and 1D or 2D coordination polymers, have been isolated. All complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, and thermogravimetric analysis. Complex 1 is a discrete rectangular macrocycle, while complex 2 is a 2D macrocycle-based coordination polymer in which the L(2) ligand adopts both syn and anti conformations. Complexes 3-5 are discrete MOCCs in which two binuclear metal clusters are engaged by four organic ligands. The different geometries of the secondary building units (SBUs) and the axial coordinated solvates on the SBUs result in their different symmetries. Complex 6 is a 1D coordination polymer, extended from a MOCC made up of two metal ions and three L(4) ligands. All of the flexible dicarboxylate ligands adopt a syn conformation except that in complex 2, indicating that the syn conformational ligand is helpful for the formation of a metallamacrocycle and a MOCC. The magnetic properties of complexes 5 and 6 have also been studied.

Generation of Benzyne Species from Diphenylphosphoryl Derivatives: Simultaneous Exchange of Three Functional Groups.

PubMed

Gorobets, Evgueni; Parvez, Masood; Derksen, Darren J; Keay, Brian A

2016-06-13

Interaction of (2-diphenylphosphoryl-3-iodo-4-methoxy-phenyl) methanol with NaH in DMF at ambient temperature results in the generation of benzyne intermediates that can be trapped by furan or DMF. Trapping with DMF forms 3-(dimethylaminomethyl)-2-hydroxy-6-methoxybenzaldehyde demonstrating the simultaneous exchange of three functionalities in a single step. The presence of the alkoxy substituent adjacent to iodine is critical for high regioselectivity addition of DMF. The corresponding bromide or triflate can be used in place of the iodide with equal efficiency. This methodology was used to synthesize the reported structure of gigasol and leading to a structural reassignment of this biscoumarin natural product. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dimethyl fumarate attenuates intracerebroventricular streptozotocin-induced spatial memory impairment and hippocampal neurodegeneration in rats.

PubMed

Majkutewicz, Irena; Kurowska, Ewelina; Podlacha, Magdalena; Myślińska, Dorota; Grembecka, Beata; Ruciński, Jan; Plucińska, Karolina; Jerzemowska, Grażyna; Wrona, Danuta

2016-07-15

Intracerebroventricular (ICV) injection of streptozotocin (STZ) is a widely-accepted animal model of sporadic Alzheimer's disease (sAD). The present study evaluated the ability of dimethyl fumarate (DMF), an agent with antioxidant and anti-inflammatory properties, to prevent spatial memory impairments and hippocampal neurodegeneration mediated by ICV injection of STZ in 4-month-old rats. Rodent chow containing DMF (0.4%) or standard rodent chow was made available on day 0. Rat body weight and food intake were measured daily for whole the experiment (21days). STZ or vehicle (SHAM) ICV injections were performed on days 2 and 4. Spatial reference and working memory were evaluated using the Morris water maze on days 14-21. Cells containing Fluoro-Jade B (neurodegeneration marker), IL-6, IL-10 were quantified in the hippocampus and choline acetyltransferase (ChAT) in the basal forebrain. The disruption of spatial memory and a high density of hippocampal CA1-3 cells labeled with Fluoro-Jade B or containing IL-6 or IL-10 were observed in the STZ group but not in the STZ+DMF group, as compared to the SHAM or SHAM+DMF groups. STZ vs. STZ+DMF differences were found: worse reference memory acquisition, fewer ChAT-positive neurons in the medial septum (Ch1), more Fluoro-Jade-positive CA1 hippocampal cells in STZ rats. DMF therapy in a rodent model of sAD prevented the disruption of spatial reference and working memory, loss of Ch1 cholinergic cells and hippocampal neurodegeneration as well as the induction of IL-6 and IL-10 in CA1. These beneficial cognitive and molecular effects validate the anti-inflammatory and neuroprotective properties of DMF in the hippocampus. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermochemistry of paddle wheel MOFs: Cu-HKUST-1 and Zn-HKUST-1.

PubMed

Bhunia, Manas K; Hughes, James T; Fettinger, James C; Navrotsky, Alexandra

2013-06-25

Metal-organic framework (MOF) porosity relies upon robust metal-organic bonds to retain structural rigidity upon solvent removal. Both the as-synthesized and activated Cu and Zn polymorphs of HKUST-1 were studied by room temperature acid solution calorimetry. Their enthalpies of formation from dense assemblages (metal oxide (ZnO or CuO), trimesic acid (TMA), and N,N-dimethylformamide (DMF)) were calculated from the calorimetric data. The enthalpy of formation (ΔHf) of the as-synthesized Cu-HKUST-H2O ([Cu3TMA2·3H2O]·5DMF) is -52.70 ± 0.34 kJ per mole of Cu. The ΔHf for Zn-HKUST-DMF ([Zn3TMA2·3DMF]·2DMF) is -54.22 ± 0.57 kJ per mole of Zn. The desolvated Cu-HKUST-dg [Cu3TMA2] has a ΔHf of 16.66 ± 0.51 kJ/mol per mole Cu. The ΔHf for Zn-HKUST-amorph [Zn3TMA2·2DMF] is -3.57 ± 0.21 kJ per mole of Zn. Solvent stabilizes the Cu-HKUST-H2O by -69.4 kJ per mole of Cu and Zn-HKUST-DMF by at least -50.7 kJ per mole of Zn. Such strong chemisorption of solvent is similar in magnitude to the strongly exothermic binding at low coverage for chemisorbed H2O on transition metal oxide nanoparticle surfaces. The strongly exothermic solvent-framework interaction suggests that solvent can play a critical role in obtaining a specific secondary building unit (SBU) topology.

Electrochemical and spectroelectrochemical studies on UO(2)(saloph)L (saloph = N,N'-disalicylidene-o-phenylenediaminate, L=dimethyl sulfoxide or N,N-dimethylformamide).

PubMed

Mizuoka, Koichiro; Kim, Seong-Yun; Hasegawa, Miki; Hoshi, Toshihiko; Uchiyama, Gunzo; Ikeda, Yasuhisa

2003-02-24

To examine properties of pentavalent uranium, U(V), we have carried out electrochemical and spectroelectrochemical studies on UO(2)(saloph)L [saloph = N,N'-disalicylidene-o-phenylenediaminate, L = dimethyl sulfoxide (DMSO) or N,N-dimethylformamide (DMF)]. The electrochemical reactions of UO(2)(saloph)L complexes in L were found to occur quasireversibly. The reduction processes of UO(2)(saloph)L complexes were followed spectroelectrochemically by using an optical transparent thin layer electrode cell. It was found that the absorption spectra measured at the applied potentials from 0 to -1.650 V versus ferrocene/ferrocenium ion redox couple (Fc/Fc(+)) for UO(2)(saloph)DMSO in DMSO have clear isosbestic points and that the evaluated electron stoichiometry equals 1.08. These results indicate that the reduction product of UO(2)(saloph)DMSO is [U(V)O(2)(saloph)DMSO](-), which is considerably stable in DMSO. Furthermore, it was clarified that the absorption spectrum of the [U(V)O(2)(saloph)DMSO](-) complex has a very small molar absorptivity in the visible region and characteristic absorption bands due to the 5f(1) orbital at around 750 and 900 nm. For UO(2)(saloph)DMF in DMF, the clear isosbestic points were not observed in the similar spectral changes. It is proposed that the UO(2)(saloph)DMF complex is reduced to [U(V)O(2)(saloph)DMF](-) accompanied by the dissociation of DMF as a successive reaction. The formal redox potentials of UO(2)(saloph)L in L (E(0), vs Fc/Fc(+)) for U(VI)/U(V) couple were determined to be -1.550 V for L = DMSO and -1.626 V for L = DMF.

Zinc-assisted hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran.

PubMed

Saha, Basudeb; Bohn, Christine M; Abu-Omar, Mahdi M

2014-11-01

2,5-Dimethylfuran (DMF), a promising cellulosic biofuel candidate from biomass derived intermediates, has received significant attention because of its low oxygen content, high energy density, and high octane value. A bimetallic catalyst combination containing a Lewis-acidic Zn(II) and Pd/C components is effective for 5-hydroxymethylfurfural (HMF) hydrodeoxygenation (HDO) to DMF with high conversion (99%) and selectivity (85% DMF). Control experiments for evaluating the roles of zinc and palladium revealed that ZnCl2 alone did not catalyze the reaction, whereas Pd/C produced 60% less DMF than the combination of both metals. The presence of Lewis acidic component (Zn) was also found to be beneficial for HMF HDO with Ru/C catalyst, but the synergistic effect between the two metal components is more pronounced for the Pd/Zn system than the Ru/Zn. A comparative analysis of the Pd/Zn/C catalyst to previously reported catalytic systems show that the Pd/Zn system containing at least four times less precious metal than the reported catalysts gives comparable or better DMF yields. The catalyst shows excellent recyclability up to 4 cycles, followed by a deactivation, which could be due to coke formation on the catalyst surface. The effectiveness of this combined bimetallic catalyst has also been tested for one-pot conversion of fructose to DMF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protection by dimethyl fumarate against diabetic cardiomyopathy in type 1 diabetic mice likely via activation of nuclear factor erythroid-2 related factor 2.

PubMed

Hu, Xinyue; Rajesh, Mohanraj; Zhang, Jian; Zhou, Shanshan; Wang, Shudong; Sun, Jian; Tan, Yi; Zheng, Yang; Cai, Lu

2018-05-01

Oxidative stress and inflammation play key roles in the development of diabetic cardiomyopathy (DCM). Dimethyl fumarate (DMF), an FDA approved medicine for relapsing multiple sclerosis, has manifested its antioxidant and anti-inflammatory function mostly in the central nervous system. In this study, we investigated whether DMF could attenuate the development of DCM. Type 1 diabetes mouse model was established using multiple low-dose streptozotocin, and the diabetic mice were treated with DMF (10 mg/kg body weight) for 3 months. Cardiac functions were determined using echocardiography. Oxidative stress, pro-inflammatory cytokines and pro-fibrotic markers were determined with commercially available kits, real-time quantitative PCR or western blot techniques. DCM was characterized by diminished cardiac function, accompanied by oxidative stress and enhanced expression of pro-inflammatory cytokines. Diabetic cardiac tissue exhibited marked fibrosis, revealed by extracellular matrix deposition as determined by Sirius red staining of the myocardial tissues. Furthermore, Nrf2 and its downstream effectors were repressed in diabetic myocardium. On the contrary, diabetic animals treated with DMF exhibited blunted oxidative stress, inflammation, fibrosis and this correlated with Nrf2 activation. Our findings suggest that DMF could potentially thwart diabetes-induced myocardial tissue injury, likely via activation of Nrf2 function, providing firm impetus for future repurposing of DMF in the management of DCM. Copyright © 2018 Elsevier B.V. All rights reserved.

Fumaric Acid Esters Do Not Reduce Inflammatory NF-κB/p65 Nuclear Translocation, ICAM-1 Expression and T-Cell Adhesiveness of Human Brain Microvascular Endothelial Cells.

PubMed

Haarmann, Axel; Nehen, Mathias; Deiß, Annika; Buttmann, Mathias

2015-08-13

Dimethyl fumarate (DMF) is approved for disease-modifying treatment of patients with relapsing-remitting multiple sclerosis. Animal experiments suggested that part of its therapeutic effect is due to a reduction of T-cell infiltration of the central nervous system (CNS) by uncertain mechanisms. Here we evaluated whether DMF and its primary metabolite monomethyl fumarate (MMF) modulate pro-inflammatory intracellular signaling and T-cell adhesiveness of nonimmortalized single donor human brain microvascular endothelial cells at low passages. Neither DMF nor MMF at concentrations of 10 or 50 µM blocked the IL-1β-induced nuclear translocation of NF-κB/p65, whereas the higher concentration of DMF inhibited the nuclear entry of p65 in human umbilical vein endothelium cultured in parallel. DMF and MMF also did not alter the IL-1β-stimulated activation of p38 MAPK in brain endothelium. Furthermore, neither DMF nor MMF reduced the basal or IL-1β-inducible expression of ICAM-1. In accordance, both fumaric acid esters did not reduce the adhesion of activated Jurkat T cells to brain endothelium under basal or inflammatory conditions. Therefore, brain endothelial cells probably do not directly mediate a potential blocking effect of fumaric acid esters on the inflammatory infiltration of the CNS by T cells.

Polyacrylonitrile nanofiber as polar solvent N,N-dimethyl formamide sensor based on quartz crystal microbalance technique

NASA Astrophysics Data System (ADS)

Rianjanu, A.; Julian, T.; Hidayat, S. N.; Suyono, E. A.; Kusumaatmaja, A.; Triyana, K.

2018-04-01

Here, we describe an N,N-dimethyl formamide (DMF) vapour sensor fabricated by coating polyacrylonitrile (PAN) nanofiber structured on quartz crystal microbalance (QCM). The PAN nanofiber sensors with an average diameter of 225 nm to 310 nm were fabricated via electrospinning process with different mass deposition on QCM substrate. The nanostructured of PAN nanofiber offers a high specific surface area that improved the sensing performance of nanofiber sensors. Benefiting from that fine structure, and high polymer-solvent affinity between PAN and DMF, the development of DMF sensors presented good response at ambient temperature. Since there is no chemical reaction between PAN nanofiber and DMF vapour, weak physical interaction such absorption and swelling were responsible for the sensing behavior. The results are indicating that the response of PAN nanofiber sensors has more dependency on the nanofiber structure (specific surface area) rather than its mass deposition. The sensor also showed good stability after a few days sensing. These findings have significant implications for developing DMF vapour sensor based on QCM coated polymer nanofibers.

Stepwise assembly of a semiconducting coordination polymer [Cd8S(SPh)14(DMF)(bpy)]n and its photodegradation of organic dyes.

PubMed

Xu, Chao; Hedin, Niklas; Shi, Hua-Tian; Xin, ZhiFeng; Zhang, Qian-Feng

2015-04-14

Chalcogenolate clusters can be interlinked with organic linkers into semiconducting coordination polymers with photocatalytic properties. Here, discrete clusters of Cd8S(SPh)14(DMF)3 were interlinked with 4,4'-bipyridine into a one dimensional coordination polymer of [Cd8S(SPh)14(DMF)(bpy)]n with helical chains. A stepwise mechanism for the assembly of the coordination polymer in DMF was revealed by an ex situ dynamic light scattering study. The cluster was electrostatically neutral and showed a penta-supertetrahedral structure. During the assembly each cluster was interlinked with two 4,4'-bipyridine molecules, which replaced the two terminal DMF molecules of the clusters. In their solid-state forms, the cluster and the coordination polymer were semiconductors with wide band gaps of 3.08 and 2.80 ev. They photocatalytically degraded rhodamine B and methylene blue in aqueous solutions. The moderate conditions used for the synthesis could allow for further in situ studies of the reaction-assembly of related clusters and coordination polymers.

Digital Microfluidics for Nucleic Acid Amplification

PubMed Central

Veigas, Bruno; Fortunato, Elvira; Martins, Rodrigo; Águas, Hugo; Igreja, Rui; Baptista, Pedro V.

2017-01-01

Digital Microfluidics (DMF) has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings. PMID:28672827

Risk factors and prevalence of dental fluorosis and dental caries in school children of North India.

PubMed

Plaka, Kavita; Ravindra, Khaiwal; Mor, Suman; Gauba, Krishan

2017-01-01

The aim of the study was to assess the prevalence of dental fluorosis, dental caries, and associated risk factors in the school children of district Fatehgarh Sahib, Punjab, India, using a cross-sectional study design. Oral health status of children aged between 8 and 15 years was assessed using World Health Organization (WHO) 2013 criteria. Dental fluorosis was assessed using Dean's index, and dental caries were recorded using decayed, missing, filled/decayed, extracted, filled (DMF/def) indices. Four hundred school children were examined, of which 207 were in the 8-11-year-old group and 193 were in the 12-15-year-old group. The overall prevalence of dental fluorosis was 4.1%, which might be linked to a high concentration of fluoride in drinking water at certain locations of rural Punjab. The prevalence of dental caries was 36.5% with a mean DMF score of 0.3 and def score of 0.6. Risk factors for dental caries include oral hygiene behavior and sugar consumption patterns. The study highlights the need to increase awareness about the oral health and hygiene among the school children in India.

Oral health status and treatment needs of pregnant women in Lagos State.

PubMed

Agbelusi, G A; Akinwande, J A; Shutti, Y O

2000-09-01

The oral health status and treatment needs of 250 pregnant women attending the antenatal clinic at Randle Health Centre was investigated. A coded questionnaire was administered to the pregnant women followed by their oral examination in the dental clinic. The mean oral hygiene index score increased progressively throughout pregnancy viz 1st trimester 0.72, second trimester 1.06 and third trimester 1.23. Community Periodontal Index of Treatment Needs (CPITN) revealed that 50% required scale and polish and oral hygiene instruction, 13.60% required oral hygiene instruction only and 32.2% did not require any treatment. Decayed Missing and Filled (DMF) recorded was 1.54. 51.72% of the pregnant women required amalgam fillings, 23.27% required extraction due to caries and 16.38% required partial dentures.

Two novel penetrating coordination polymers based on flexible S-containing dicarboxylate acid with sensing properties towards Fe3+ and Cr2O72- ions

NASA Astrophysics Data System (ADS)

Chen, Zhiwei; Mi, Xiuna; Wang, Suna; Lu, Jing; Li, Yunwu; Li, Dacheng; Dou, Jianmin

2018-05-01

Two new coordination polymers (CPs), namely, {[Zn(L)(bpp)]·DMF}n (1) and {[Zn(L)(bpe)]·DMF}n (2) (L = 2,2'-[benzene-1,3-diylbis(methanediylsulfanediyl)]dibenzoic acid, bpp= 1,3-bis(4-pyridyl)propane, bpe = 1,2-Bis(4-pyridyl)ethylene, DMF = N,N-Dimethylformamide), have been solvothermally synthesized and fully characterized. Complex 1 displays a 2D→2D three-fold"false" interpenetrating structure while complex 2 possesses a novel 3-D 4-connected structure with fascinating self-penetrating moieties. The luminescence studies reveal that these complexes exhibited excellent selectivity for Fe3+ and Cr2O72- ions in DMF. The sensing mechanism was investigated through PXRD, XPS , EDS mapping measurements, and discussed in details.

Current technologies, economics, and perspectives for 2,5-dimethylfuran production from biomass-derived intermediates.

PubMed

Saha, Basudeb; Abu-Omar, Mahdi M

2015-04-13

Since the U.S. Department of Energy (DOE) published a perspective article that described the potential of the top ten biomass-derived platform chemicals as petroleum replacements for high-value commodity and specialty chemicals, researchers around the world have been motivated to develop technologies for the conversion of biomass and biomass-derived intermediates into chemicals and fuels. Among several biorefinery processes, the conversion of biomass carbohydrates into 2,5-dimethylfuran (DMF) has received significant attention because of its low oxygen content, high energy content, and high octane value. DMF can further serve as a petroleum-replacement, biorenewable feedstock for the production of p-xylene (pX). In this review, we aim specifically to present a concise and up-to-date analysis of DMF production technologies with a critical discussion on catalytic systems, mechanistic insight, and process economics, which includes sensitivity analysis, so that more effective catalysts can be designed. Special emphasis has been given to bifunctional catalysts that improve DMF yields and selectivity and the synergistic effect of the bifunctional sites. Process economics for the current processes and the scope for further improvement are discussed. It is anticipated that the chemistry detailed in this review will guide researchers to develop more practical catalytic processes to enable the economic production of bio-based DMF. Processes for the upgrade of DMF to pX are also described. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DMF as an Additive in a Two-Step Spin-Coating Method for 20% Conversion Efficiency in Perovskite Solar Cells.

PubMed

Wu, Jionghua; Xu, Xin; Zhao, Yanhong; Shi, Jiangjian; Xu, Yuzhuan; Luo, Yanhong; Li, Dongmei; Wu, Huijue; Meng, Qingbo

2017-08-16

DMF as an additive has been employed in FAI/MAI/IPA (FA= CH 2 (NH 2 ) 2 , MA = CH 3 NH 3 , IPA = isopropanol) solution for a two-step multicycle spin-coating method in order to prepare high-quality FA x MA 1-x PbI 2.55 Br 0.45 perovskite films. Further investigation reveals that the existence of DMF in the FAI/MAI/IPA solution can facilitate perovskite conversion, improve the film morphology, and reduce crystal defects, thus enhancing charge-transfer efficiency. By optimization of the DMF amount and spin-coating cycles, compact, pinhole-free perovskite films are obtained. The nucleation mechanisms of perovskite films in our multicycle spin-coating process are suggested; that is, the introduction of DMF in the spin-coating FAI/MAI/IPA solution can lead to the formation of an amorphous phase PbX 2 -AI-DMSO-DMF (X = I, Br; A = FA, MA) instead of intermediate phase (MA) 2 Pb 3 I 8 ·2DMSO. This amorphous phase, similar to that in the one-step method, can help FAI/MAI penetrate into the PbI 2 framework to completely convert into the perovskite. As high as 20.1% power conversion efficiency (PCE) has been achieved with a steady-state PCE of 19.1%. Our work offers a simple repeatable method to prepare high-quality perovskite films for high-performance PSCs and also help further understand the perovskite-crystallization process.

Analysis of the Photomagnetic Properties of Cyano-Bridged Heterobimetallic Complexes by X-Ray Diffraction

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

Svendsen, Helle; Jørgensen, Mads Ry Vogel; Overgaard, Jacob

2012-10-11

Single crystal synchrotron X-ray diffraction measurements have been carried out on [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O (DMF = dimethyl-formamide), 1; [Y(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 2; [Ce(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 3; [Sm(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 4; [Tb(DMF){sub 4}(H{sub 2}O)3({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 5; [Yb(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 6; and [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Co(CN){sub 5}] {center_dot} H{sub 2}O, 7, at 15(2) K with and without UV illumination of the crystals. Significant changes in unit cell parameters are observed for all of themore » iron-containing complexes, while compound 7 shows no response to UV illumination. These results are consistent with previous results and are furthermore reproduced by powder synchrotron X-ray diffraction for compounds 1 and 7. Photoexcited crystal structures have been determined for 1-6 from refinements of two-conformer models, and excited state occupancies in the range 80-94% are found. Significant bond length changes are observed for the Fe-ligand bonds (up to 0.06 {angstrom}), the cyano bonds (up to 0.02 {angstrom}), and the lanthanide-ligand bonds (up to 0.1 {angstrom}). On the contrary, powder X-ray diffraction on the simple compound K{sub 3}Fe(CN)6, 8, upon UV illumination does not show any structural changes, suggesting that the photomagnetic effect requires the presence of both the transition metal and the lanthanide ion. Photomagnetic measurements show an increase in magnetization of the excited state of 1 of up to 3%, which is much diminished compared with previously published values of 45%. Furthermore, they show that the isostructural complex [La(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 9, exhibits identical magnetic responses in the UV-induced excited crystal structure.« less

A review of digital microfluidics as portable platforms for lab-on a-chip applications.

PubMed

Samiei, Ehsan; Tabrizian, Maryam; Hoorfar, Mina

2016-07-07

Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.

Metal-organic framework: Structure and magnetic properties of [Cu3(BTC)2 (L)x·(CuO)y]n (L=H2O, DMF)

NASA Astrophysics Data System (ADS)

da Silva, Gilvaldo G.; Machado, F. L. A.; Junior, S. Alves; Padrón-Hernández, E.

2017-09-01

The compounds [Cu3(BTC)2(L)x·(CuO)y], with BTC (benzene 1,3,5-tricarboxylate) and L (H2O or DMF) were prepared using electrochemical synthesis. Structural and morphologic characterizations were performed by X-ray diffraction and scanning electronic microscopy. The [Cu3(BTC)2 (L)x·(CuO)y] contain dimeric [Cu2(O2CR)]4 units with three possible spin configurations arising from Cu(II) 3d9 states and Cu-Cu δ bond. We observed an unusual very strong antiferromagnetic coupling in temperatures ranging from 100 K to 350 K for [Cu3(BTC)2.(H2O)3. (CuO)y]n. The inverse susceptibility versus temperature shows a linearity from 20 K up to 65 K fitting the Curie-Weiss law, for L = DMF. The CW X-band electron paramagnetic resonance spectroscopy (EPR) was important to explore the coordination state for DMF in the network. It was observed that DMF is located in an equatorial geometry of the coordination network experimenting interactions from the nitrogen and copper ions.

Dimethyl fumarate blocks pro-inflammatory cytokine production via inhibition of TLR induced M1 and K63 ubiquitin chain formation.

PubMed

McGuire, Victoria A; Ruiz-Zorrilla Diez, Tamara; Emmerich, Christoph H; Strickson, Sam; Ritorto, Maria Stella; Sutavani, Ruhcha V; Weiβ, Anne; Houslay, Kirsty F; Knebel, Axel; Meakin, Paul J; Phair, Iain R; Ashford, Michael L J; Trost, Matthias; Arthur, J Simon C

2016-08-08

Dimethyl fumarate (DMF) possesses anti-inflammatory properties and is approved for the treatment of psoriasis and multiple sclerosis. While clinically effective, its molecular target has remained elusive - although it is known to activate anti-oxidant pathways. We find that DMF inhibits pro-inflammatory cytokine production in response to TLR agonists independently of the Nrf2-Keap1 anti-oxidant pathway. Instead we show that DMF can inhibit the E2 conjugating enzymes involved in K63 and M1 polyubiquitin chain formation both in vitro and in cells. The formation of K63 and M1 chains is required to link TLR activation to downstream signaling, and consistent with the block in K63 and/or M1 chain formation, DMF inhibits NFκB and ERK1/2 activation, resulting in a loss of pro-inflammatory cytokine production. Together these results reveal a new molecular target for DMF and show that a clinically approved drug inhibits M1 and K63 chain formation in TLR induced signaling complexes. Selective targeting of E2s may therefore be a viable strategy for autoimmunity.

Distraction by a monotube fixator to achieve limb lengthening: predictive factors for tibia trauma

PubMed Central

2013-01-01

Background Management of post trauma tibia bone gap varied with orthopedic surgeons’ experience and tools available. Study aims to determine predictive factors for distraction by a monotube fixator (DMF) outcome in post tibia trauma limb length discrepancy. Methods A prospective descriptive cross sectional study of post traumatized tibia bone gap and limb length discrepancy patients at tertiary hospitals. Patient’s informed consent and institutional ethical committee approval were obtained. Bio-data, clinical and healing indexes were documented. DMF was applied for patient that met inclusion criteria. The Statistic tests used included the Chi-square, the Student’s two-tailed t test, and the Wilcox on rank-sum test when appropriate. Mantel-Haenszel Common Odds Ratio (OR) and 95% confidence intervals for poor outcome potential risk factors were recorded. Bivariate correlation and logistic regression were evaluated. Significance level was set at a p value <0.05. Results Thirty-six patients with mean age, 37.2 ± 10.3 year and male/female ratio of 1:1.25 had DMF applied. Motorcycle accident accounted for 50.0% of patients and diaphyseal segment was most commonly affected 25 (69.4%). The mean bone lengthened was 10.1 ± 4.0 cm (range: 5-21 cm) and mean duration of bone transport was 105.6 ± 38.2 days. The means of rate of distraction, healing index and percentage of lengthening were 0.99 ± 0.14 mm/day, 15.6 ± 4.3 days/cm and 38.0 ± 14.3 respectively. The mean follow up was 9.7 ±4.9 months (range: 2–17.0). Per operative complications varied and outcome was satisfactory in 30 (83.3%). Obesity (p <0.0001), multiple surgery (p = 0.012) and transfusion (p = 0.001) correlated to poor outcome. Percentage lengthening ≥ 50%, bone gap >10 cm, anemia, blood transfusion, general anesthesia administration, distraction rate >1 mm/day, osteomyelitis and prolong partial weight bearing were significant predictive factors for poor outcome in post traumatic tibia distraction. Conclusion Distraction by a monotube fixator appears effective in achieving correction >38.0% original tibia lengthening following traumatic bone gap. Predictive factors for poor outcome were useful for prognostication. PMID:23672599

The budget impact of introducing delayed-release dimethyl fumarate for treatment of relapse-remitting multiple sclerosis in Canada.

PubMed

Dorman, Emily; Kansal, Anuraag R; Sarda, Sujata

2015-01-01

Multiple sclerosis (MS) causes significant disability globally and is especially prevalent in Canada. Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) is an orally administered disease-modifying treatment (DMT) for patients with relapsing-remitting MS (RRMS) that is currently on the market in the US, Australia, Canada, and Europe. A budget impact model (BIM) was developed to assess the financial consequences of introducing DMF for treatment of RRMS in Canada. A BIM calculated the financial consequences of introducing DMF in Canada over 3 years based on RRMS prevalence, treatment market share, and clinical effects. RRMS prevalence in Canada was derived from published literature and natural relapse rates, and disease state distribution from clinical trial data. It was conservatively assumed that 100% of RRMS patients were treated with a DMT. DMF was assumed to absorb market share proportionally from the following current treatments: interferon beta-1a-IM, interferon beta-1a-SC, interferon beta-1b, and glatiramer acetate. Treatment efficacy, in terms of relapse rate reductions and treatment discontinuation rates, was determined from mixed treatment comparison. Treatment costs (including costs of acquisition, monitoring, and administration) and cost of relapse were considered. Deterministic one-way sensitivity analyses were conducted to assess the most sensitive input parameters. Over 3 years, the introduction of DMF resulted in an average annual increase of CAD417 per treated patient per year, with reductions in costs associated with relapses (CAD192/patient/year) partially offsetting increased drug acquisition costs (CAD602/patient/year). On a population level, the average annual cost increase was CAD24,654,237, a CAD 0.68 increase per population covered by the Canadian healthcare system. The main drivers of budget impact were drop-out rates, proportion of RRMS patients treated, and market share assumptions. The acquisition costs of DMF for treatment of RRMS are predicted to be partially offset by reduced costs of relapses in the Canadian healthcare system.

5,7-Dimethoxyflavone, an activator of PPARα/γ, inhibits UVB-induced MMP expression in human skin fibroblast cells.

PubMed

Kim, Jae Kyung; Mun, Sukyeong; Kim, Myung-Suk; Kim, Mi-Bo; Sa, Bo-Kyung; Hwang, Jae-Kwan

2012-03-01

Peroxisome proliferator-activated receptors (PPARs), which are members of the nuclear hormone receptor superfamily, are a family of ligand-activated transcription factors that consist of three isotypes (PPAR α, δ and γ). PPAR activity was previously thought to be limited to lipid metabolism and glucose homeostasis; however, intensive studies of PPARα/γ in recent years have revealed their importance in age-related inflammation and photoaging as regulators of cytokines, matrix metalloproteinases (MMPs) and nuclear factor-kappa B (NF-κB). We evaluated the ability of the PPARα/γ activator 5,7-dimethoxyflavone (5,7-DMF) to inhibit ultraviolet B (UVB)-induced MMP expression in Hs68 human skin fibroblasts. Hs68 cells were treated with 5,7-DMF and then exposed to UVB irradiation. MMP expression, production and activity were determined by reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay and gelatin zymography. PPARα/γ expression, catalase expression, and mitogen-activated protein kinase (MAPK), activator protein-1 (AP-1) and NF-κB signalling were evaluated by Western blot analysis. PPARα/γ activity was assessed with the GAL4/PPARα/γ transactivation assay. We found that 5,7-DMF strongly decreased MMP expression, production and activity. In addition, 5,7-DMF significantly increased PPARα/γ activation and catalase expression, thereby downregulating UVB-induced reactive oxygen species (ROS) production, ROS-induced MAPK signalling and downstream transcription factors. Finally, 5,7-DMF reduced IκBα phosphorylation, blocked NF-κB p65 nuclear translocation, strongly suppressed proinflammatory cytokines such as interleukin-6 (IL-6) and IL-8. 5,7-DMF prevents UVB-induced MMP expression by suppressing UVB-induced oxidative stress and age-related inflammation via NF-κB and MAPK/AP-1 pathways. Our findings suggest the usefulness of 5,7-DMF for preventing and treating skin photoaging. © 2011 John Wiley & Sons A/S.

Physicochemical and catalytic properties of Au nanorods micro-assembled in solvents of varying dipole moment and refractive index

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

Kaur, Rupinder; Pal, Bonamali, E-mail: bpal@thapar.edu

2015-02-15

Highlights: • Physicochemical activities of Au nanorods in water largely differ from organic solvents. • Au nanorods agglomeration increased with dipole moments of different polar solvents. • Refractive indexes of Au nanorods dispersion in various polar solvents are enhanced. • Electrokinetics significantly altered depending on agglomerated size of Au nanorods. • Catalysis or co-catalysis activity is varied as per the extent of Au nanorods coagulation. - Abstract: This paper deals with the impact of dipole moment (1.66–3.96 D) and refractive index (1.333–1.422) of the dispersion solvent on the plasmon absorption, surface charge, zeta potential, and adsorption properties of Au nanorodsmore » (AuNRs). AuNRs (length ≈ 53 nm and width ≈ 20 nm) undergo agglomeration (size 50–180 nm) with increase in the dipole moment of solvent (iPrOH < MeOH < DMF < DMSO). Whereas, no such coagulation occurs in H{sub 2}O and CCl{sub 4} suspension as confirmed by DLS and TEM size distribution. The electrostatic interaction of AuNRs with its surface adsorbed solvent dipoles leads to alteration of the their ionic state, absolute electronic charge and zeta potential (+49.79 mV in H{sub 2}O, +8.99 mV in DMF and −4.65 mV in MeOH dispersion) to a greater extent. This interaction distinctly modifies the adsorption behavior of polar molecules like p-nitrophenol and salicylic acid on AuNRs surface, as evidenced by the measured changes in their electro-kinetic parameters. As a result, we observe a substantial difference in catalytic and co-catalytic activities of AuNRs dispersed in various solvents as mentioned above because the catalytic properties of AuNRs are strongly dependent on the type of solvent in which they are dispersed.« less

Salivary flow and dental caries in Brazilian youth with type 1 diabetes mellitus.

PubMed

Alves, Cresio; Menezes, Rafaela; Brandão, Marcia

2012-01-01

Although type 1 diabetes mellitus (T1DM) has a significant impact on oral health, its association with dental caries is yet not clear. The aim of this study was to evaluate the salivary flow rate and caries in Brazilian youth with type 1 diabetes mellitus. A Cross-sectional study was performed in a tertiary university hospital. Fifty-one age matched subjects suffering from type 1 diabetes mellitus were selected for the study and evaluated for the following: salivary flow rate, number of decayed, missing and filled tooth in permanent dentition (DMF-T) and decayed, extracted, filled tooth index in the deciduous dentition (def-t); visible plaque index (VPI) and gingival bleeding index (GBI). STATISTICS AND ANALYSIS: The t test was utilized when the variables showed normal distribution. The Mann-Whitney test was utilized for comparing non-normal variables. Kolmorgorov-Smirnov test was used to assess the normality assumption. The differences were considered significant when P < 0.05. The age and gender distribution of patients and controls was 11.3 ± 3.4 years (56% males) and 11.9 ± 3.4 years (37% males). The mean glycated hemoglobin value in the diabetics was 9.7 ± 1.9%. Salivary flow rate was lower in the diabetic patients as compared to controls (P = 0.02). No differences were found in the DMF-T/def-t indices of diabetic and non-diabetic patients (P = 0.43/0.14). VPI was similar in both the groups (P = 0.15). GBI was higher in the diabetics (8.1 vs. 5.18; P = 0.11). There were no differences in the dental caries experience and dental plaque in the two groups. The lower salivary flow rate in diabetics could have been related to their higher GBI. The higher GBI in the diabetics is a matter of concern in the diabetics and is a sign for higher chances of developing periodontal problems.

Fabrication of MTN-type zeolite by self-assembling of supramolecular compound

NASA Astrophysics Data System (ADS)

Huang, Aisheng; Caro, Jürgen

2009-10-01

MTN-type (Zeolite Socony Mobil Thirty-Nine) zeolite was prepared at 473 K by a novel method through self-assembling of a supramolecular compound called 2,4,6-tris (4-pyridyl) triazine (TPT) in DMF (N,N-dimethylformamide). The effects of fluoride, DMF and germanium on the synthesis of MTN-type zeolite were investigated. The crystallization was facilitated by adding fluoride to the synthesis solution, resulting in the formation of highly crystalline MTN samples, while some amorphous phase was observed in fluoride-free batches. DMF was required to obtain a highly crystalline MTN sample, since TPT dissolves easier in DMF than in water, thus facilitating the self-assembling of TPT into a 3D network to structure the MTN framework. The MTN structure could be synthesized at low germanium content (Ge/Si≤0.18), while AST (AlPO 4-sixteen) as a foreign phase is formed at high germanium substitution (Ge/Si≥0.5).

Droplet Microfluidics for Chip-Based Diagnostics

PubMed Central

Kaler, Karan V. I. S.; Prakash, Ravi

2014-01-01

Droplet microfluidics (DMF) is a fluidic handling technology that enables precision control over dispensing and subsequent manipulation of droplets in the volume range of microliters to picoliters, on a micro-fabricated device. There are several different droplet actuation methods, all of which can generate external stimuli, to either actively or passively control the shape and positioning of fluidic droplets over patterned substrates. In this review article, we focus on the operation and utility of electro-actuation-based DMF devices, which utilize one or more micro-/nano-patterned substrates to facilitate electric field-based handling of chemical and/or biological samples. The underlying theory of DMF actuations, device fabrication methods and integration of optical and opto-electronic detectors is discussed in this review. Example applications of such electro-actuation-based DMF devices have also been included, illustrating the various actuation methods and their utility in conducting chip-based laboratory and clinical diagnostic assays. PMID:25490590

Design and construction of porous metal-organic frameworks based on flexible BPH pillars

NASA Astrophysics Data System (ADS)

Hao, Xiang-Rong; Yang, Guang-sheng; Shao, Kui-Zhan; Su, Zhong-Min; Yuan, Gang; Wang, Xin-Long

2013-02-01

Three metal-organic frameworks (MOFs), [Co2(BPDC)2(4-BPH)·3DMF]n (1), [Cd2(BPDC)2(4-BPH)2·2DMF]n (2) and [Ni2(BDC)2(3-BPH)2 (H2O)·4DMF]n (3) (H2BPDC=biphenyl-4,4'-dicarboxylic acid, H2BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N'-dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has "single-pillared" MOF-5-like motif with inner cage diameters of up to 18.6 Å. Framework 2 has "double pillared" MOF-5-like motif with cage diameters of 19.2 Å while 3 has "double pillared" 8-connected framework with channel diameters of 11.0 Å. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework.

Mucin levels in saliva of adolescents with dental caries

PubMed Central

Gabryel-Porowska, Halina; Gornowicz, Agnieszka; Bielawska, Anna; Wójcicka, Anna; Maciorkowska, Elżbieta; Grabowska, Stanisława Zyta; Bielawski, Krzysztof

2014-01-01

Background Human saliva, a complex secretion that contains a mixture of inorganic and organic molecules, plays an essential role in the maintenance of oral health. Mucins are the major macromolecular component of the secretion and are considered the first line of defense for epithelial tissues. The aim of this study was to compare levels of mucins (MUC5B, MUC7, and MUC1) in saliva of young subjects with dental caries. Material/Methods All patients had DMF (decay/missing/filled) higher than value 0. Eight subjects with DMF=3 (control group) and 27 adolescents with DMF >11 (research group) were recruited for this study. Clinical evaluation procedures were oral examination, including tooth, periodontal, oral mucosal status, and collection of saliva samples. Saliva was collected for mucin assay. Enzyme-linked immunosorbent assay was used to quantitate MUC5B, MUC7, and MUC1. Results Our results indicate that adolescents with very high intensity of dental caries disease had increased levels of MUC1 and MUC5B. The membrane mucin MUC1 protein levels in the group with DMF>11 (research group) were higher compared to the group with DMF=3 (control group), and the increase was statistically significant (p=0.011). Similarly, secreted mucin MUC5B protein levels were higher (p=0.06) in the group with DMF>11 (research group). Although MUC7 protein levels were slightly reduced in symptomatic subjects, the decrease was statistically insignificant (p=0.918). Conclusions Our data suggest links between the production of mucins, especially MUC1 and MUC5B in saliva, and dental caries disease. PMID:24441930

Accuracy Profiles for Analyzing Residual Solvents in Textiles by GC-MS.

PubMed

Bao, Qibei; Fu, Kejie; Ren, Qingqing; Zhong, Yingying; Qian, Dan

2017-10-01

Excess residual solvents (RSs) in clothes or other textiles could be toxic and pose risks to both humans and the environment. N,N-Dimethylformamide (DMF), N,N-dimethylacetamide (DMAc) and 1-methyl-2-pyrrolidinone (NMP) are important chemicals frequently used as solvents in the textile industry. Several organizations have proposed limiting DMF, DMAc and NMP in textiles, but an appropriate detection method has not been proposed. A sensitive GC-MS method for the quantification of DMF, DMAc and NMP in textiles was developed. After extraction with ethyl acetate, these RSs were separated on a DB-5MS capillary column. The oven temperature was increased from 50°C (held for 0.5 min) at 10°C/min to 120°C (held for 1 min). The method was fully validated according to the accuracy profile procedure, which is based on β-expectation tolerance intervals for the total measurement bias. Linearity was observed in the range of 0.5-10 mg/L for the solvents with limit of quantification values of 4.2, 3.5 and 2.5 mg/kg for DMF, DMAc and NMP, respectively. The repeatability and intermediate precision were <5.34% and 7.95% for DMF, 5.37% and 9.68% for DMAc, and 2.68% and 5.85% for NMP. The recoveries of DMF, DMAc and NMP were 91.2-106.3%, 89.5-97.7% and 85.6-101.3%, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Highly Sensitive and Automated Surface Enhanced Raman Scattering-based Immunoassay for H5N1 Detection with Digital Microfluidics.

PubMed

Wang, Yang; Ruan, Qingyu; Lei, Zhi-Chao; Lin, Shui-Chao; Zhu, Zhi; Zhou, Leiji; Yang, Chaoyong

2018-04-17

Digital microfluidics (DMF) is a powerful platform for a broad range of applications, especially immunoassays having multiple steps, due to the advantages of low reagent consumption and high automatization. Surface enhanced Raman scattering (SERS) has been proven as an attractive method for highly sensitive and multiplex detection, because of its remarkable signal amplification and excellent spatial resolution. Here we propose a SERS-based immunoassay with DMF for rapid, automated, and sensitive detection of disease biomarkers. SERS tags labeled with Raman reporter 4-mercaptobenzoic acid (4-MBA) were synthesized with a core@shell nanostructure and showed strong signals, good uniformity, and high stability. A sandwich immunoassay was designed, in which magnetic beads coated with antibodies were used as solid support to capture antigens from samples to form a beads-antibody-antigen immunocomplex. By labeling the immunocomplex with a detection antibody-functionalized SERS tag, antigen can be sensitively detected through the strong SERS signal. The automation capability of DMF can greatly simplify the assay procedure while reducing the risk of exposure to hazardous samples. Quantitative detection of avian influenza virus H5N1 in buffer and human serum was implemented to demonstrate the utility of the DMF-SERS method. The DMF-SERS method shows excellent sensitivity (LOD of 74 pg/mL) and selectivity for H5N1 detection with less assay time (<1 h) and lower reagent consumption (∼30 μL) compared to the standard ELISA method. Therefore, this DMF-SERS method holds great potentials for automated and sensitive detection of a variety of infectious diseases.

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

Pegis, Michael L.; Roberts, John A. S.; Wasylenko, Derek J.

A variety of next-generation energy processes utilize the electrochemical interconversions of dioxygen and water as the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Reported here are the first estimates of the standard reduction potential of the O2 + 4e– + 4H+ ⇌ 2H2O couple in organic solvents. The values are +1.21 V in acetonitrile (MeCN) and +0.60 V in N,N-dimethylformamide (DMF), each versus the ferrocenium/ferrocene couple (Fc+/0) in the respective solvent (as are all of the potentials reported here). The potentials have been determined using a thermochemical cycle that combines the free energy for transferring water frommore » aqueous solution to organic solvent, -0.43 kcal mol–1 for MeCN and -1.47 kcal mol–1 for DMF, and the potential of the H+/H2 couple, – 0.028 V in MeCN and -0.662 V in DMF. The H+/H2 couple in DMF has been directly measured electrochemically using the previously reported procedure for the MeCN value. The thermochemical approach used for the O2/H2O couple has been extended to the CO2/CO and CO2/CH4 couples to give values of -0.12 and +0.15 V in MeCN and -0.73 and -0.48 V in DMF, respectively. Extensions to other reduction potentials are discussed. Additionally, the free energy for transfer of protons from water to organic solvent is estimated as +14 kcal mol–1 for acetonitrile and +0.6 kcal mol–1 for DMF.« less

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

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

D Banerjee; J Finkelstein; A Smirnov

2011-12-31

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg{sub 4}(3,5-PDC){sub 4}(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-Dmore » network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.« less

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

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

Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.

2015-10-15

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network withmore » a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.« less

Hexakis(N,N-dimethyl­formamide-κO)cobalt(II) bis­(perchlorate)

PubMed Central

Eissmann, Frank; Böhle, Tony; Mertens, Florian O. R. L.; Weber, Edwin

2010-01-01

The asymmetric unit of the title complex, [Co(DMF)6](ClO4)2 (DMF = N,N-dimethyl­formamide, C3H7NO), consists of two half complex cations with the Co2+ metal ions located on centers of inversion and two perchlorate anions. In the crystal packing, each Co2+ ion is coordinated by six mol­ecules of DMF in a slightly distorted octa­hedral geometry. The crystal structure is mainly stabilized by coordinative, ionic and C—H⋯O hydrogen-bonding inter­actions. PMID:21580225

Gas-Phase Coordination Complexes of UVIO{2/2+}, NpVIO{2/2+}, and PuVIO{2/2+} with Dimethylformamide

NASA Astrophysics Data System (ADS)

Rutkowski, Philip X.; Rios, Daniel; Gibson, John K.; van Stipdonk, Michael J.

2011-11-01

Electrospray ionization of actinyl perchlorate solutions in H2O with 5% by volume of dimethylformamide (DMF) produced the isolatable gas-phase complexes, [AnVIO2(DMF)3(H2O)]2+ and [AnVIO2(DMF)4]2+, where An = U, Np, and Pu. Collision-induced dissociation confirmed the composition of the dipositive coordination complexes, and produced doubly- and singly-charged fragment ions. The fragmentation products reveal differences in underlying chemistries of uranyl, neptunyl, and plutonyl, including the lower stability of Np(VI) and Pu(VI) compared with U(VI).

Nonaqueous System of Iron-Based Ionic Liquid and DMF for the Oxidation of Hydrogen Sulfide and Regeneration by Electrolysis.

PubMed

Guo, Zhihui; Zhang, Tingting; Liu, Tiantian; Du, Jun; Jia, Bing; Gao, Shujing; Yu, Jiang

2015-05-05

To improve the hydrogen sulfide removal efficiency with the application of an iron-based imidazolium chloride ionic liquid (Fe(III)-IL) as desulfurizer, Fe(II) and N,N-dimethylformamide (DMF) are introduced to Fe(III)-IL to construct a new nonaqueous desulfurization system (Fe(III/II)-IL/DMF). Following desulfurization, the system can be regenerated using the controlled-potential electrolysis method. The addition of Fe(II) in Fe(III)-IL is beneficial for the hydrogen sulfide removal and the electrochemical regeneration of the desulfurizer. The addition of DMF in Fe(III/II)-IL does not change the structure of Fe(III/II)-IL but clearly decreases the acidity, increases the electrolytic current, and decreases the stability of the Fe-Cl bond in Fe(III/II)-IL. Fe(III/II)-IL/DMF can remove hydrogen sulfide and can be regenerated through an electrochemical method more efficiently than can Fe(III/II)-IL. After six cycles, the desulfurization efficiency remains higher than 98%, and the average conversion rate of Fe(II) is essentially unchanged. No sulfur peroxidation occurs, and the system remains stable. Therefore, this new nonaqueous system has considerable potential for removing H2S in pollution control applications.

Dimethyl fumarate modulation of immune and antioxidant responses: application to HIV therapy

PubMed Central

Gill, Alexander J.; Kolson, Dennis L.

2013-01-01

The persistence of chronic immune activation and oxidative stress in human immunodeficiency virus (HIV)-infected, antiretroviral drug-treated individuals are major obstacles to fully preventing HIV disease progression. The immune modulator and antioxidant dimethyl fumarate (DMF) is effective in treating immune-mediated diseases and it also has potential applications to limiting HIV disease progression. Among the relevant effects of DMF and its active metabolite monomethyl fumarate (MMF) are induction of a Th1 → Th2 lymphocyte shift, inhibition of pro-inflammatory cytokine signaling, inhibition of NF-κB nuclear translocation, inhibition of dendritic cell maturation, suppression of lymphocyte and endothelial cell adhesion molecule expression, and induction of the Nrf2-dependent antioxidant response element (ARE) and effector genes. Associated with these effects are reduced lymphocyte and monocyte infiltration into psoriatic skin lesions in humans and immune-mediated demyelinating brain lesions in rodents, which confirms potent systemic and central nervous system (CNS) effects. In addition, DMF and MMF limit HIV infection in macrophages in vitro, albeit by unknown mechanisms. Finally, DMF and MMF also suppress neurotoxin production from HIV-infected macrophages, which drives CNS neurodegeneration. Thus, DMF might protect against systemic and CNS complications in HIV infection through its effective suppression of immune activation, oxidative stress, HIV replication, and macrophage-associated neuronal injury. PMID:23971529

Cyanide-limited complexation of molybdenum(III): synthesis of octahedral [Mo(CN)(6)](3-) and cyano-bridged [Mo(2)(CN)(11)](5-).

PubMed

Beauvais, Laurance G; Long, Jeffrey R

2002-03-13

Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature moment of mu(eff) = 3.80 mu(B), and assignment of its absorption bands leads to the ligand field parameters Delta(o) = 24800 cm(-1) and B = 247 cm(-1). Further restricting the available cyanide in a reaction between Mo(CF(3)SO(3))(3) and (Et(4)N)CN in DMF, followed by recrystallization from DMF/MeOH, yields (Et(4)N)(5)[Mo(2)(CN)(11)] x 2DMF x 2MeOH (2). The dinuclear [Mo(2)(CN)(11)](5-) complex featured therein contains two octahedrally coordinated Mo(III) centers spanned by a bridging cyanide ligand. A fit to the magnetic susceptibility data for 2, gives J = -113 cm(-1) and g = 2.33, representing the strongest antiferromagnetic coupling yet observed through a cyanide bridge. Efforts to incorporate these new complexes in magnetic Prussian blue-type solids are ongoing.

Therapeutic effects of oral dimethyl fumarate on stroke induced by middle cerebral artery occlusion: An animal experimental study.

PubMed

Safari, Anahid; Fazeli, Mehdi; Namavar, Mohammad Reza; Tanideh, Nader; Jafari, Peyman; Borhani-Haghighi, Afshin

2017-01-01

Dimethyl fumarate (DMF) has immune-modulatory and neuro-protective characteristics that can be used for treatment of acute ischemic stroke. To investigate the therapeutic effects of DMF on histological and functional recovery of rats after transient middle cerebral artery (MCA) occlusion. 22 Sprague-Dawley male rats weighing 275-300 g were randomized into three groups by block randomization. In the sham group (n = 7), the neck was opened, but neither MCA was occluded, nor any drug was administered.The control group (n = 7) was treated with vehicle (methocel) by gavage for 14 days after MCA occlusion. In the DMF-treated group (n = 8), treatment was performed with 15 mg/kg body weight dimethyl fumarate twice a day for 14 days after MCA occlusion. Transient occlusion of the right MCA was performed by intraluminal thread method in the DMF-treated and the control group. Neurological deficit score (NDS), pole test, and adhesive removal test were performed before the surgery, and on post-operative Days 0, 3, 5, 7, 10, and 14. After the final behaviour test, the animals' brains were perfused and removed. Brains were frozen and sectioned serially and coronally using a cryostat. Infract volume and brain volume were estimated by stereology. The percentage of infarct volume was significantly lower in DMF-treated animals (5.76%) than in the control group (22.39%) (P < 0.0001). Regarding behavioural tests, the DMF-treated group showed better function in NDS on Days 7 (P = 0.041) and 10 (P = 0.046), but not in pole and adhesive removal tests. There was no significant correlation between behavioural tests and histological results. Dimethyl fumarate could be beneficial as a potential neuroprotective agent in the treatment of stroke.

Standard reduction potentials for oxygen and carbon dioxide couples in acetonitrile and N, N -dimethylformamide

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

Pegis, Michael L.; Roberts, John A. S.; Wasylenko, Derek J.

A variety of next-generation energy processes utilize the electrochemical interconversions of dioxygen and water as the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Reported here are the first estimates of the standard reduction potential of the O 2 + 4e – + 4H + ⇌ 2H 2O couple in organic solvents. The values are +1.21 V in acetonitrile (MeCN) and +0.60 V in N,N-dimethylformamide (DMF), each versus the ferrocenium/ferrocene couple (Fc +/0) in the respective solvent (as are all of the potentials reported here). The potentials have been determined using a thermochemical cycle that combines the freemore » energy for transferring water from aqueous solution to organic solvent, –0.43 kcal mol –1 for MeCN and –1.47 kcal mol –1 for DMF, and the potential of the H +/H 2 couple, – 0.028 V in MeCN and –0.662 V in DMF. The H +/H 2 couple in DMF has been directly measured electrochemically using the previously reported procedure for the MeCN value. The thermochemical approach used for the O 2/H 2O couple has been extended to the CO 2/CO and CO 2/CH 4 couples to give values of –0.12 and +0.15 V in MeCN and –0.73 and –0.48 V in DMF, respectively. Here, extensions to other reduction potentials are discussed. Additionally, the free energy for transfer of protons from water to organic solvent is estimated as +14 kcal mol –1 for acetonitrile and +0.6 kcal mol –1 for DMF.« less

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

Zhang, Yingjie, E-mail: yzx@ansto.gov.au; Karatchevtseva, Inna; Bhadbhade, Mohan

With the coordination of dimethylformamide (DMF), two new uranium(VI) complexes with either 4-hydroxybenzoic acid (H{sub 2}phb) or terephthalic acid (H{sub 2}tph) have been synthesized under solvothermal conditions and structurally characterized. [(UO{sub 2}){sub 2}(Hphb){sub 2}(phb)(DMF)(H{sub 2}O){sub 3}]·4H{sub 2}O (1) has a dinuclear structure constructed with both pentagonal and hexagonal bipyramidal uranium polyhedra linked through a µ{sub 2}-bridging ligand via both chelating carboxylate arm and alcohol oxygen bonding, first observation of such a coordination mode of 4-hydroxybenzoate for 5 f ions. [(UO{sub 2})(tph)(DMF)] (2) has a three-dimensional (3D) framework built with pentagonal bipyramidal uranium polyhedra linked with µ{sub 4}-terephthalate ligands. The 3Dmore » channeled structure is facilitated by the unique carboxylate bonding with nearly linear C–O–U angles and the coordination of DMF molecules. The presence of phb ligands in different coordination modes, uranyl ions in diverse environments and DMF in complex 1, and tph ligand, DMF and uranyl ion in complex 2 has been confirmed by Raman spectroscopy. In addition, their thermal stability and photoluminescence properties have been investigated. - Graphical abstract: With the coordination of dimethylformamide, two new uranyl complexes with either 4-hydroxybenzoate or terephthalate have been synthesized under solvothermal conditions and structurally characterized. - Highlights: • Solvent facilitates the synthesis of two new uranium(VI) complexes. • A dinuclear complex with both penta- and hexagonal bipyramidal uranium polyhedral. • A unique µ{sub 2}-bridging mode of 4-hydroxybenzoate via alcohol oxygen for 5 f ions. • A 3D framework with uranium polyhedra and µ{sub 4}-terephthalate ligands. • Vibration modes and photoluminescence properties are reported.« less

Standard reduction potentials for oxygen and carbon dioxide couples in acetonitrile and N, N -dimethylformamide

DOE PAGES

Pegis, Michael L.; Roberts, John A. S.; Wasylenko, Derek J.; ...

2015-12-07

A variety of next-generation energy processes utilize the electrochemical interconversions of dioxygen and water as the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Reported here are the first estimates of the standard reduction potential of the O 2 + 4e – + 4H + ⇌ 2H 2O couple in organic solvents. The values are +1.21 V in acetonitrile (MeCN) and +0.60 V in N,N-dimethylformamide (DMF), each versus the ferrocenium/ferrocene couple (Fc +/0) in the respective solvent (as are all of the potentials reported here). The potentials have been determined using a thermochemical cycle that combines the freemore » energy for transferring water from aqueous solution to organic solvent, –0.43 kcal mol –1 for MeCN and –1.47 kcal mol –1 for DMF, and the potential of the H +/H 2 couple, – 0.028 V in MeCN and –0.662 V in DMF. The H +/H 2 couple in DMF has been directly measured electrochemically using the previously reported procedure for the MeCN value. The thermochemical approach used for the O 2/H 2O couple has been extended to the CO 2/CO and CO 2/CH 4 couples to give values of –0.12 and +0.15 V in MeCN and –0.73 and –0.48 V in DMF, respectively. Here, extensions to other reduction potentials are discussed. Additionally, the free energy for transfer of protons from water to organic solvent is estimated as +14 kcal mol –1 for acetonitrile and +0.6 kcal mol –1 for DMF.« less

First Observation of Photoinduced Magnetization for the Cyano-Bridged 3d 4f Heterobimetallic Assembly Nd(DMF)4(H2O)3(μ-CN)Fe(CN)5ṡH2O (DMF=N,N-Dimethylformamide)

NASA Astrophysics Data System (ADS)

Li, Guangming; Akitsu, Takashiro; Sato, Osamu; Einaga, Yasuaki

2004-12-01

Photoinduced magnetization of the cyano-bridged 3d 4f hetero-bimetallic assembly Nd (DMF)4(H2O)3(μ-CN)Fe(CN)5ṡH2O (1) (DMF=N,N-dimethylformamide) is described in this paper. The χM T values are enhanced by about 45% after UV light illumination in the temperature range of 5 50 K. We propose that UV light illumination induces a structural distortion in 1. This small structural change is propagated by molecular interactions in the inorganic network. Furthermore, the cooperativity resulting from the molecular interaction functions to increase the activation energy of the relaxation processes, which makes observation of the photoexcited state possible. The flexible network structure through the hydrogen bonds in 1 plays an essential role for the photoinduced phenomenon. This finding may open up a new domain for developing molecule-based magnetic materials.

Cross-benzoin and Stetter-type reactions mediated by KOtBu-DMF via an electron-transfer process.

PubMed

Ragno, Daniele; Zaghi, Anna; Di Carmine, Graziano; Giovannini, Pier Paolo; Bortolini, Olga; Fogagnolo, Marco; Molinari, Alessandra; Venturini, Alessandro; Massi, Alessandro

2016-10-18

The condensation of aromatic α-diketones (benzils) with aromatic aldehydes (benzoin-type reaction) and chalcones (Stetter-type reaction) in DMF in the presence of catalytic (25 mol%) KOtBu is reported. Both types of umpolung processes proceed with good efficiency and complete chemoselectivity. On the basis of spectroscopic evidence (MS analysis) of plausible intermediates and literature reports, the occurrence of different ionic pathways have been evaluated to elucidate the mechanism of a model cross-benzoin-like reaction along with a radical route initiated by an electron-transfer process to benzil from the carbamoyl anion derived from DMF. This mechanistic investigation has culminated in a different proposal, supported by calculations and a trapping experiment, based on double electron-transfer to benzil with formation of the corresponding enediolate anion as the key reactive intermediate. A mechanistic comparison between the activation modes of benzils in KOtBu-DMF and KOtBu-DMSO systems is also described.

Relationship between caries experience and demarcated hypomineralised lesions (including MIH) in the permanent dentition of 15-year-olds.

PubMed

Kühnisch, Jan; Kabary, Lamiaa; Malyk, Yuri; Rothmaier, Katrin; Metz, Isabel; Hickel, Reinhard; Heinrich, Joachim; Manton, David; Standl, Marie

2018-06-01

This cross-sectional study compared the caries experience in 15-year-olds with and without demarcated hypomineralised lesions (DHL) in permanent teeth. One thousand three hundred and two 15-year-old adolescents from two ongoing birth cohorts (GINIplus15 and LISAplus15) were examined to determine non-cavitated carious lesions (NCCL) and the DMF index. Furthermore, DHL was scored on all permanent teeth/surfaces according to the molar-incisor hypomineralisation criteria of the European Academy of Paediatric Dentistry (MIH/EAPD). Adolescents with DHL were categorised into those with a minimum of one DHL in the permanent dentition (DHL ≥ 1), with DHL on at least one first permanent molar (MIH/EAPD) and with DHL on at least one first permanent molar and permanent incisor (MIH/Severe). The study was conducted in the metropolitan area of Munich. The proportion of children without caries amounted to 63.7% (DMF > 0) and 26.0% (D 1-4 MF > 0); the caries experience was mean = 4.0(SD = 5.2) NCCL/T and 0.9(1.7) DMF/T. Existence of DHL ≥ 1, MIH/EAPD and MIH/Severe was detected in 40.2, 17.2 and 9.8% of all adolescents, respectively. The corresponding DMF/T values were: no DHL 0.9(1.7); DHL ≥ 1 1.0(1.7); MIH/EAPD 1.1(1.6); MIH/Severe 1.1(1.7). The group of adolescents with MIH/EAPD and MIH/Severe were found to have statistically higher caries rates in comparison to those with no DHL. Caries and DHL are prevalent and influenced the dental health of 15-year-old adolescents. A significant positive association existed between the presence of caries and DHL. Children with MIH/EAPD or MIH/Severe had a higher probability to develop carious lesions in the permanent dentition.

Synthesis, structure, and luminescent properties of microporous lanthanide metal-organic frameworks with inorganic rod-shaped building units.

PubMed

Guo, Xiaodan; Zhu, Guangshan; Sun, Fuxing; Li, Zhongyue; Zhao, Xiaojun; Li, Xiaotian; Wang, Hanchang; Qiu, Shilun

2006-03-20

A series of microporous lanthanide metal-organic frameworks, Tb3(BDC)(4.5)(DMF)2(H2O)3.(DMF)(H2O) (1) and Ln3(BDC)(4.5)(DMF)2(H2O)3.(DMF)(C2H5OH)(0.5)(H2O)(0.5) [Ln = Dy (2), Ho (3), Er (4)], have been synthesized by the reaction of the lanthanide metal ion (Ln3+) with 1,4-benzenedicarboxylic acid and triethylenetetramine in a mixed solution of N,N'-dimethylformamide (DMF), water, and C(2)H(5)OH. X-ray diffraction analyses reveal that they are extremely similar in structure and crystallized in triclinic space group P. An edge-sharing metallic dimer and 4 metallic monomers assemble with 18 carboxylate groups to form discrete inorganic rod-shaped building units [Ln6(CO2)18], which link to each other through phenyl groups to lead to three-dimensional open frameworks with approximately 4 x 6 A rhombic channels along the [0,-1,1] direction. A water sorption isotherm proves that guest molecules in the framework of complex 1 can be removed to create permanent microporosity and about four water molecules per formula unit can be adsorbed into the micropores. These complexes exhibit blue fluorescence, and complex 1 shows a Tb3+ characteristic emission in the range of 450-650 nm.

Shearing Low-frictional 3D Granular Materials

NASA Astrophysics Data System (ADS)

Chen, David; Zheng, Hu; Behringer, Robert

Shear jamming occurs in frictional particles over a range of packing fractions, from random loose to random dense. Simulations show shear jamming for frictionless spheres, but over a vanishing range as the system size grows. We use packings of submerged and diffractive index-matched hydrogel particles to determine the shear-induced microscopic response of 3D, low-frictional granular systems near jamming, bridging the gap between frictionless and low friction packings. We visualize the particles by a laser scanning technique, and we track particle motion along with their interparticle contact forces from its 3D-reconstructions. NSF-DMF-1206351, NASA NNX15AD38G, William M. Keck Foundation, and DARPA.

A comprehensive experimental and detailed chemical kinetic modelling study of 2,5-dimethylfuran pyrolysis and oxidation

PubMed Central

Somers, Kieran P.; Simmie, John M.; Gillespie, Fiona; Conroy, Christine; Black, Gráinne; Metcalfe, Wayne K.; Battin-Leclerc, Frédérique; Dirrenberger, Patricia; Herbinet, Olivier; Glaude, Pierre-Alexandre; Dagaut, Philippe; Togbé, Casimir; Yasunaga, Kenji; Fernandes, Ravi X.; Lee, Changyoul; Tripathi, Rupali; Curran, Henry J.

2013-01-01

The pyrolytic and oxidative behaviour of the biofuel 2,5-dimethylfuran (25DMF) has been studied in a range of experimental facilities in order to investigate the relatively unexplored combustion chemistry of the title species and to provide combustor relevant experimental data. The pyrolysis of 25DMF has been re-investigated in a shock tube using the single-pulse method for mixtures of 3% 25DMF in argon, at temperatures from 1200–1350 K, pressures from 2–2.5 atm and residence times of approximately 2 ms. Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350–1800 K at equivalence ratios (ϕ) of 0.5, 1.0 and 2.0 along with auto-ignition measurements for stoichiometric fuel in air mixtures of 25DMF at 20 and 80 bar, from 820–1210 K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770–1220 K, at 10.0 atm, residence times of 0.7 s and at ϕ = 0.5, 1.0 and 2.0. Laminar burning velocities for 25DMF-air mixtures have been measured using the heat-flux method at unburnt gas temperatures of 298 and 358 K, at atmospheric pressure from ϕ = 0.6–1.6. These laminar burning velocity measurements highlight inconsistencies in the current literature data and provide a validation target for kinetic mechanisms. A detailed chemical kinetic mechanism containing 2768 reactions and 545 species has been simultaneously developed to describe the combustion of 25DMF under the experimental conditions described above. Numerical modelling results based on the mechanism can accurately reproduce the majority of experimental data. At high temperatures, a hydrogen atom transfer reaction is found to be the dominant unimolecular decomposition pathway of 25DMF. The reactions of hydrogen atom with the fuel are also found to be important in predicting pyrolysis and ignition delay time experiments. Numerous proposals are made on the mechanism and kinetics of the previously unexplored intermediate temperature combustion pathways of 25DMF. Hydroxyl radical addition to the furan ring is highlighted as an important fuel consuming reaction, leading to the formation of methyl vinyl ketone and acetyl radical. The chemically activated recombination of HȮ2 or CH3Ȯ2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methyl-2-furylmethanoxy radical and ȮH or CH3Ȯ radical is also found to exhibit significant control over ignition delay times, as well as being important reactions in the prediction of species profiles in a JSR. Kinetics for the abstraction of a hydrogen atom from the alkyl side-chain of the fuel by molecular oxygen and HȮ2 radical are found to be sensitive in the estimation of ignition delay times for fuel-air mixtures from temperatures of 820–1200 K. At intermediate temperatures, the resonantly stabilised 5-methyl-2-furanylmethyl radical is found to predominantly undergo bimolecular reactions, and as a result sub-mechanisms for 5-methyl-2-formylfuran and 5-methyl-2-ethylfuran, and their derivatives, have also been developed with consumption pathways proposed. This study is the first to attempt to simulate the combustion of these species in any detail, although future refinements are likely necessary. The current study illustrates both quantitatively and qualitatively the complex chemical behavior of what is a high potential biofuel. Whilst the current work is the most comprehensive study on the oxidation of 25DMF in the literature to date, the mechanism cannot accurately reproduce laminar burning velocity measurements over a suitable range of unburnt gas temperatures, pressures and equivalence ratios, although discrepancies in the experimental literature data are highlighted. Resolving this issue should remain a focus of future work. PMID:24273333

Effect on caries experience of a long-term preventive program for mothers and children starting during pregnancy.

PubMed

Günay, H; Dmoch-Bockhorn, K; Günay, Y; Geurtsen, W

1998-09-01

The aim of this three-phase prospective study was to determine the effects of a primary-primary prevention program on the oral health of children. Eighty-six pregnant women from various social backgrounds participated in the first phase of this study. In the second phase (at 3 years of age) 54 of the mother-child couples and in the third phase (at 4 years of age) 47 of the mother-child couples remained. Participants were recalled every 6 months and received individual prophylactic care. The following clinical parameters were assessed at each examination period for mother and child: DMF-S or dmf-s, proximal plaque index, and the salivary level of Streptococcus mutans (Dentocult SM). The control group consisted of 65 (at 3 years of age) and 45 (at 4 years of age) children from various kindergartens. All children in the second phase of the study group revealed a naturally healthy dentition with an API of 0-25% and a salivary S. mutans score of 0 (0-10(3) cfu/ml). In the third phase, only four of the 47 children of the study group showed caries, with a mean dmf-s of 1.5. No S. mutans could be detected in 20 (42.6%) children. Ten (21.3%) children of the study group showed a S. mutans score of > or = 2 (> 10(5) cfu/ml). In contrast, only 53 of the 65 children of the control group (second phase) and 26 of the 45 control children (third phase) revealed a naturally healthy dentition. The remaining 19 children of the control group revealed a mean dmf-s of 7.0 at 4 years of age. In the control group, no S. mutans could be detected in 25 (38.5%) children at 3 years of age whereas 21 (32.3%) children showed a S. mutans score of > or = 2. In the third phase, a salivary S. mutans score of > or = 2 was found in 27 (60%) children of the control group. The statistical comparison between the study and the control groups revealed significant differences for all results determined (P < 0.001). Additionally, all mothers revealed a significant improvement in oral health and a reduction of salivary S. mutans colonization. From our data we conclude that a pre- and postnatal prevention program (primary-primary vs primary prevention) may significantly improve the oral health of mother and child.

76 FR 71581 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

...., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above... are received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF....S. Coast Guard, Assistant Commandant for Command, Control, Communications, Computers and Information...

77 FR 65897 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-31

...., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above... received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2012-26718...

75 FR 19414 - Collection of Information Under Review by Office of Management and Budget: OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-14

... Street, NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Fax. (a) To DMF, 202... the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this... Guard, Acting Assistant Commandant for Command, Control, Communications, Computers and Information...

76 FR 66737 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

...., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above... received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2011-27755...

Efficient simultaneous adsorption-biodegradation of high-concentrated N,N-dimethylformamide from water by Paracoccus denitrificans-graphene oxide microcomposites

NASA Astrophysics Data System (ADS)

Zheng, Yuan; Chen, Dongyun; Li, Najun; Xu, Qingfeng; Li, Hua; He, Jinghui; Lu, Jianmei

2016-02-01

Water contamination becomes one of the most pervasive environmental issues all over the world in recent years. In this paper, the functionalization of graphene oxide (GO) with copolymers containing methacrylic acid (MAA) and butyl methacrylate (BMA) was investigated to prepare a new microcomposite material (PGO) via free radical solution polymerization. PGO was used for the adsorption of N,N-dimethylformamide (DMF) from aqueous solution by utilizing the characteristics of ultralarge surface and the Van der Waals force between DMF molecules and polymers on the surface of PGO. Besides, PGO was used not only a high-capable adsorbent but also a carrier for the immobilization of Paracoccus denitrificans cells in the treatment of high-concentrated DMF. Bacterial cells could immobilized on the PGO (PGO@P. denitrificans) stably by covalent coupling process after acclimatization and high-concentrated DMF (2000 mg/L) could be removed completely and relatively rapidly from aqueous solutions by the simultaneous adsorption-biodegradation (SAB) process of PGO@P. denitrificans. Furthermore, the excellent recycle performance of PGO@P. denitrificans made the whole process more economical and practical.

Solvent influence on complex formation between Cd2+ and 2-hydroxy-1,4-naphthoquinone in binary mixed nonaqueous solvents at 15-45°C

NASA Astrophysics Data System (ADS)

Farazandeh, R.; Rounaghi, G. H.; Ebrahimi, M.; Basafa, S.

2017-04-01

The complexation reaction of Cd2+ cation with 2-hydroxy-1,4-naphthoquinone (HNQ) was studied in acetonitrile (AN), 2-PrOH, ethyl acetate (EtOAc), EtOH, dimethylformamide (DMF) and in binary solutions AN-2-PrOH, AN-DMF, AN-EtOH, and AN-EtOAc using conductometric method at 15-45°C. The conductance data show that the stoichiometry of the Cd2+ complex with HNQ in all solvent systems is 1 : 1. In the pure solvents the stability of the complex changes in the order AN > 2-PrOH > EtOH > DMF. The stability of the complex at 25°C in the studied mixtures changes in the following order : AN-EtOAc > AN-2-PrOH > AN-EtOH > AN-DMF. These orders are affected by the nature and composition of the solvent systems and by the temperature. From the temperature dependence data, the thermodynamic functions values (Δ H° and Δ S°) for the complex formation were calculated.

Investigating the geometrical preferences of a flexible benzimidazolone-based linker in the synthesis of coordination polymers

PubMed Central

Jones, Corey L.; Marsden, Elizabeth A.; Nevin, Adam C.; Kariuki, Benson M.; Bhadbhade, Mohan M.; Martin, Adam D.

2017-01-01

A series of new group 2 coordination polymers, MgL ={MgL(H2O)(DMF)0.75}∞, CaL = {CaL(DMF)2}∞, SrL = {SrL(H2O)0.5}∞ and BaL = {BaL(H2O)0.5}∞, were synthesized using a flexible benzimidazolone diacetic acid linker (H2L) in which the two carboxylic acid binding sites are connected to a planar core via {–CH2–} spacers that can freely rotate in solution. In a ‘curiosity-led' diversion from group 2 metals, the first row transition metal salts Mn2+, Cu2+ and Zn2+ were also reacted with L to yield crystals of MnL = {MnL(DMF)(H2O)3.33}∞, Cu3L2 = {Cu3L2(DMF)2(CHO2)2}∞ and ZnL = {ZnL(DMF)}∞. Crystal structures were obtained for all seven materials. All structures form as two-dimensional sheets and contain six-coordinate centres, with the exception of ZnL, which displays tetrahedrally coordinated metal centres, and Cu3L2, which contains square planar coordinated metal centres and Cu paddle-wheels. In each structure, the linker adopts one of two distinct conformations, with the carboxylate groups either cis or trans with respect to the planar core. All materials were also characterized by powder X-ray diffraction and thermogravimetric analysis. PMID:29308246

An Eco-tank system containing microbes and different aquatic plant species for the bioremediation of N,N-dimethylformamide polluted river waters.

PubMed

Xiao, Jibo; Chu, Shuyi; Tian, Guangming; Thring, Ronald W; Cui, Lingzhou

2016-12-15

An Eco-tank system of 10m was designed to simulate the natural river. It consisted of five tanks sequentially connected containing microbes, biofilm carriers and four species of floating aquatic plants. The purification performance of the system for N,N-dimethylformamide (DMF) polluted river water was evaluated by operating in continuous mode. DMF was completely removed in Tanks 1 and 2 at influent DMF concentrations between 75.42 and 161.05mg L -1 . The NH 4 + -N concentration increased in Tank 1, followed by a gradual decrease in Tanks 2-5. Removal of NH 4 + -N was enhanced by aeration. The average effluent NH 4 + -N concentration of Tank 5 decreased to a minimum of 0.89mg L -1 , corresponding to a decrease of 84.8% when compared with that before aeration. TN concentration did not decrease significantly as expected after inoculation with denitrifying bacteria. The average effluent TN concentration of the system was determined to be 4.58mg L -1 , still unable to satisfy the Class V standard for surface water environmental quality. The results of this study demonstrated that the Eco-tank system is an efficient process in removing DMF, TOC, and NH 4 + -N from DMF polluted river water. However, if possible, alternative technologies should be adopted for controlling the effluent TN concentration. Copyright © 2016 Elsevier B.V. All rights reserved.

[Effect of N, N-dimethylformamide on oxidation or antioxidation status among occupational exposed workers].

PubMed

Cheng, Juan; Liu, Qiang; Xu, Bo; Wu, Zhijun; Ye, Meng; Jiang, Xiao; Wang, Chunmin

2014-01-01

To explore the effect of N,N-dimethylformamide (DMF) on oxidation or antioxidation status among occupational exposed workers. A total of 104 DMF exposed workers and 101 controls were recruited in this study in May 2012. The information of occupational history, age, gender, smoking and alcohol habits of all subjects were collected by questionnaire. DMF concentration in the air of workplace was tested. N-methyl-carbamoylated haemoglobin adduct (NMHb) in blood was chosen as an inner-dose biomarker, which was expressed as 3-methyl-5-isopropylhydantoin(MVH), the degeneration product of NMHb. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels were detected to reflect liver function. Serum superoxide dismutase (SOD) activity, glutathione-S-transferase (GST) activity, malondialdehyde (MDA) levels, 3- nitrotyrosine (3-NT) levels were detected to reflect oxidative/antioxidative status. DMF concentration in workplace air was within the range of 3.3-12.4 mg/m(3), which did not exceed our national standard. The MVH level in exposed workers was (19.69 ± 12.52) mg/kg, but was not detectable in control group. The activity of SOD in exposed workers ((125.30 ± 21.23) U/ml) was significantly higher than the control group ((118.35 ± 18.48) U/ml, t = -2.47, P = 0.014). However, the activity of SOD showed different trends with the increasing of MVH level. When MVH ≤ 24 mg/kg, the SOD activity increased with the increasing of MVH level (r = 0.356, P = 0.002). However, when MVH> 24 mg/kg, SOD activity expressed decreasing trend with the increasing of MVH level (r = -0.260, P = 0.150). No significant differences were observed in GST, MDA, 3-NT, ALT, AST levels among the two groups. DMF exposure might have stimulatory effect on antioxidation system of the body under low concentration; within the range of compensatory defense, DMF exposure did not cause obvious lipid and/or protein peroxidative damage.

Supramolecular architectures of iron phthalocyanine Langmuir-Blodgett films: The role played by the solution solvents

NASA Astrophysics Data System (ADS)

Rubira, Rafael Jesus Gonçalves; Aoki, Pedro Henrique Benites; Constantino, Carlos José Leopoldo; Alessio, Priscila

2017-09-01

The developing of organic-based devices has been widely explored using ultrathin films as the transducer element, whose supramolecular architecture plays a central role in the device performance. Here, Langmuir and Langmuir-Blodgett (LB) ultrathin films were fabricated from iron phthalocyanine (FePc) solutions in chloroform (CHCl3), dichloromethane (CH2Cl2), dimethylformamide (DMF), and tetrahydrofuran (THF) to determine the influence of different solvents on the supramolecular architecture of the ultrathin films. The UV-vis absorption spectroscopy shows a strong dependence of the FePc aggregation on these solvents. As a consequence, the surface pressure vs. mean molecular area (π-A) isotherms and Brewster angle microscopy (BAM) reveal a more homogeneous (surface morphology) Langmuir film at the air/water interface for FePc in DMF. The same morphological pattern observed for the Langmuir films is preserved upon LB deposition onto solid substrates. The Raman and FTIR analyses indicate the DMF-FePc interaction relies on coordination bonds between N atom (from DMF) and Fe atom (from FePc). Besides, the FePc molecular organization was also found to be affected by the DMF-FePc chemical interaction. It is interesting to note that, if the DMF-FePc leads to less aggregated FePc either in solution or ultrathin films (Langmuir and LB), with time (one week) the opposite trend is found. Taking into account the N-Fe interaction, the performance of the FePc ultrathin films with distinct supramolecular architectures composing sensing units was explored as proof-of-principle in the detection of trace amounts of atrazine herbicide in water using impedance spectroscopy. Further statistical and computational analysis reveal not only the role played by FePc supramolecular architecture but also the sensitivity of the system to detect atrazine solutions down to 10-10 mol/L, which is sufficient to monitor the quality of drinking water even according to the most stringent international regulations.

Effect of delayed-release dimethyl fumarate on no evidence of disease activity in relapsing-remitting multiple sclerosis: integrated analysis of the phase III DEFINE and CONFIRM studies.

PubMed

Havrdova, E; Giovannoni, G; Gold, R; Fox, R J; Kappos, L; Phillips, J Theodore; Okwuokenye, M; Marantz, J L

2017-05-01

Significant effects on clinical/neuroradiological disease activity have been reported in patients with relapsing-remitting multiple sclerosis treated with delayed-release dimethyl fumarate (DMF) in phase III DEFINE/CONFIRM trials. We conducted a post hoc analysis of integrated data from DEFINE/CONFIRM to evaluate the effect of DMF on achieving no evidence of disease activity (NEDA) in patients with relapsing-remitting multiple sclerosis. The analysis included patients randomized to DMF 240 mg twice daily, placebo or glatiramer acetate (CONFIRM only) for ≤2 years. A time-to-event method was used to estimate the percentage of patients achieving NEDA. Clinical NEDA (no relapses/no 12-week confirmed disability progression) was analysed in the intention-to-treat (ITT) population. Neuroradiological (no new/newly enlarging T2 hyperintense lesions/no gadolinium-enhancing lesions) and overall NEDA (clinical and neuroradiological NEDA) were analysed in the magnetic resonance imaging (MRI) cohort. The ITT and MRI populations comprised 1540 and 692 patients, respectively. The percentage of patients with clinical NEDA (ITT population) and neuroradiological NEDA (MRI cohort) was higher with DMF versus placebo over 2 years [clinical NEDA: 38.9% relative reduction; hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.52-0.72; P < 0.0001; neuroradiological NEDA: 40.0% relative reduction; HR, 0.60; 95% CI, 0.49-0.73; P < 0.0001]. The percentage of patients achieving overall NEDA (MRI cohort) was also higher with DMF (26%) versus placebo (12%) over 2 years, with a relative risk reduction of 42.7% (HR, 0.57; 95% CI, 0.48-0.69; P < 0.0001). A significantly higher percentage of patients treated with DMF achieved NEDA status over 2 years compared with placebo. © 2017 Biogen. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.

Evaluation of amides and centrifugation temperature in boar semen cryopreservation.

PubMed

Bianchi, I; Calderam, K; Maschio, E F; Madeira, E M; da Rosa Ulguim, R; Corcini, C D; Bongalhardo, D C; Corrêa, E K; Lucia, T; Deschamps, J C; Corrêa, M N

2008-03-15

Two experiments were conducted to evaluate the use of amides as cryoprotectants and two centrifugation temperatures (15 or 24 degrees C) in boar semen cryopreservation protocols. Semen was diluted in BTS, cooled centrifuged, added to cooling extenders, followed by the addition of various cryoprotectants. In experiment 1, mean (+/-S.E.M.) sperm motility for 5% dimethylformamide (DMF; 50.6+/-1.9%) and 5% dimethylacetamide (DMA; 53.8+/-1.7%) were superior (P<0.05) to 5% methylformamide (MF; 43.2+/-2.4%) and 3% glycerol (GLY; 38.1+/-2.3%), with no significant difference between MF and GLY. Sperm membrane integrity was higher (P<0.05) for DMA than for MF or GLY (50.9+/-1.9, 43.3+/-2.5, and 34.5+/-2.8%, respectively). Sperm membrane integrity was higher in DMF (47.9+/-2.1%) than in glycerol (34.5+/-2.8%, P<0.05), but was similar to other treatments (P>0.05). In experiment 2, we tested MF, DMF, and DMA at 3, 5, and 7%. Sperm motility and membrane integrity were higher for 5% DMA (53.8+/-1.7 and 50.9+/-1.9%) and 5% DMF (50.6+/-1.9 and 47.9+/-2.1%), in comparison with 7% DMF and all MF concentrations (P<0.05). For sperm motility and membrane integrity, 5% DMA exceeded (P<0.05) 3% DM, with greater membrane integrity than 3% DMF (P<0.05). In both experiments, sperm motility and membrane integrity were superior at 15 degrees C versus 24 degrees C (P<0.05), with no interaction between centrifugation temperature and treatments (P>0.05). In conclusion, boar semen was successfully cryopreserved by replacement of glycerol with amides (especially 5% DMA) and centrifugation at 15 degrees C, with benefits for post-thaw sperm motility and membrane integrity.

Water-Free Rare Earth-Prussian Blue Type Analogues: Synthesis, Structure, Computational Analysis, and Magnetic Data of {Ln[superscript III](DMF)[subscript 6]Fe[superscript III](CN)[subcsript 6]}[subscript infinity] (Ln = Rare Earths Excluding Pm)

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

Wilson, Duane C.; Liu, Shengming; Chen, Xuenian

2009-11-04

Water-free rare earth(III) hexacyanoferrate(III) complexes, {l_brace}Ln(DMF){sub 6}({mu}-CN){sub 2}Fe(CN){sub 4}{r_brace}{sub {infinity}} (DMF = N,N-dimethylformamide; Ln = Sm, 1; Eu, 2; Gd, 3; Tb, 4; Dy, 5; Ho, 6; Er, 7; Tm, 8; Yb, 9; Lu, 10; Y, 11; La, 12; Ce, 13; Pr, 14; Nd, 15), were synthesized in dry DMF through the metathesis reactions of [(18-crown-6)K]{sub 3}Fe(CN){sub 6} with LnX{sub 3}(DMF){sub n} (X = Cl or NO{sub 3}). Anhydrous DMF solutions of LnX{sub 3}(DMF){sub n} were prepared at room temperature from LnCl{sub 3} or LnX{sub 3} {center_dot} nH{sub 2}O under a dynamic vacuum. All compounds were characterized by IR, X-raymore » powder diffraction (except for 10), and single crystal X-ray diffraction (except for 2, 7, 10). Infrared spectra reveal that a monotonic, linear relationship exists between the ionic radius of the lanthanide and the {nu}{sub {mu}-CN} stretching frequency of 1-10, 12-15 while 11 deviates slightly from the ionic radius relationship. X-ray powder diffraction data are in agreement with powder patterns calculated from single crystal X-ray diffraction results, a useful alternative for bulk sample confirmation when elemental analysis data are difficult to obtain. Eight-coordinate Ln(III) metal centers are observed for all structures. trans-cyanide units of [Fe(CN){sub 6}]{sup 3-} formed isocyanide linkages to Ln(III) resulting in one-dimensional polymeric chains. Structures of compounds 1-9 and 11 are isomorphous, crystallizing in the space group C2/c. Structures of compounds 12-15 are also isomorphous, crystallizing in the space group P2/n. One unique polymeric chain exists in the structures of 1-9 and 11 while two unique polymeric chains exist in structures of 12-15. One of the polymeric chains of 12-15 is similar to that observed for 1-9, 11 while the other is more distorted and has a shorter Ln-Fe distance. Magnetic susceptibility measurements for compounds 3-6, 8, 11 were performed on polycrystalline samples of the compounds.« less

Structural color changes in permanent enamel of patients with cleft lip and palate: a case-control study.

PubMed

Kulas, Antje; Illge, Christina; Bekes, Katrin; Eckert, Alexander W; Fuhrmann, Robert A W; Hirsch, Christian

2016-01-01

White spots are more common in patients with cleft lip and palate (CLP) than in the normal population. Whether these are due to the cleft itself or concomitant circumstances (e.g., surgical procedures, orthodontic treatments, systemic fluoridation, increased caries risk) remains unclear. This case-control study evaluated both their prevalence in CLP patients versus control subjects and associated risk factors. A total of 73 CLP patients (average age 8.7 years, range 6-18 years, 42 % male) and a control group of 73 age- and gender-matched non-CLP patients were included. Enamel color changes, subsuming mineralization defects (DDE index), mild dental fluorosis (Dean's index), and initial caries (ICDAS score 2), were recorded. Caries index (dmf-t/DMF-T) scores were also recorded to distinguish between high or low caries risk as defined by the Deutsche Arbeitsgemeinschaft für Jugendzahnpflege criteria. Histories of systemic fluoridation, trauma to primary teeth, surgery, and orthodontic treatment were obtained using a questionnaire. Statistical analysis included t test, χ (2) test, and multivariable logistic regression. Enamel color changes were observed three times more often in the CLP group than in the control group (39.7 vs. 12.3 %; p < 0.001). Significantly more patients in the CLP group had a history of orthodontic treatment (38.4 vs. 15.1 %; p < 0.05). An increased risk for enamel color changes was associated with CLP itself [OR (odds ratio) 3.6; 95 % confidence interval (CI) 1.3-9.9] and table salt plus tablets combined for systemic fluoridation (OR 2.7, 95 % CI 1.1-6.9). No increased risks were identified for increased caries risk, history of primary-tooth trauma, or history of orthodontic treatment. The higher prevalence of enamel color changes in the CLP group (more than threefold compared to the control group) was not related to previous orthodontic treatments; however, systemic fluoridation (table salt and tablets) constituted a risk factor for the enamel color changes seen in the CLP patients.

77 FR 22582 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

..., attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above, between 9 a.m. and 5 p... timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2012-9008...

76 FR 78287 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

...., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above... are received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF... Command, Control, Communications, Computers and Information Technology. [FR Doc. 2011-32233 Filed 12-15-11...

75 FR 62407 - Collection of Information Under Review by Office of Management and Budget: OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-08

... Street, NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Fax. (a) To DMF, 202... the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2010-25382...

77 FR 9949 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-21

... Street NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF... comments are received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF.... R.E. Day, Rear Admiral, U.S. Coast Guard, Assistant Commandant for Command, Control, Communications...

78 FR 74156 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

..., attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above, between 9 a.m. and 5 p... timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public.... Day, Rear Admiral, U.S. Coast Guard, Assistant Commandant for Command, Control, Communications...

76 FR 72959 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

...., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Hand Delivery: To DMF address above... are received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF... party to advertise where claims may be sent after an incident occurs. Forms: None. Burden Estimate: The...

Application of Two Cobalt-Based Metal-Organic Frameworks as Oxidative Desulfurization Catalysts.

PubMed

Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

2015-12-07

Two new porous cobalt-based metal-organic frameworks, [Co6(oba)5(OH)2(H2O)2(DMF)4]n · 5DMF (TMU-10) and [Co3(oba)3(O) (Py)0.5] n · 4DMF · Py (TMU-12) have been synthesized by solvothermal method using a nonlinear dicarboxylate ligand. Under mild reaction conditions, these compounds exhibited good catalytic activity and reusability in oxidative desulfurization (ODS) reaction of model oil which was prepared by dissolving dibenzothiophene (DBT) in n-hexane. FT-IR and Mass analysis showed that the main product of DBT oxidation is its corresponding sulfone, which was adsorbed on the surfaces of catalysts. The activation energy was obtained as 13.4 kJ/mol.

75 FR 28275 - Collection of Information Under Review by Office of Management and Budget; OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... Street, NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3) Fax. (a) To DMF, 202... the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this...: May 10, 2010. M.B. Lytle, Captain, U.S. Coast Guard, Acting Assistant Commandant for Command, Control...

Impact of an EHR-based diabetes management form on quality and outcomes of diabetes care in primary care practices.

PubMed

Herrin, Jeph; da Graca, Briget; Aponte, Phil; Stanek, H Greg; Cowling, Terianne; Fullerton, Cliff; Hollander, Priscilla; Ballard, David J

2015-01-01

Health information technology shows promise for improving chronic disease care. This study assessed the impact of a diabetes management form (DMF), accessible within an electronic health record. From 2007 to 2009, 2108 diabetes patients were seen in 20 primary care practices; 1103 visits involved use of the DMF in 2008. The primary outcome was "optimal care": HbA1c ≤8%, low-density lipoprotein (LDL) cholesterol <100 mg/dL, blood pressure <130/80 mm Hg, not smoking, and aspirin prescription in patients ≥40 years. After adjusting for number of visits, age, sex, and insulin use, DMF-exposed patients showed less improvement in attaining "optimal care" (estimated difference-in-difference [DID] = -2.06 percentage points; P < .001), LDL cholesterol (DID = -2.30; P = .023), blood pressure (DID = -3.05; P < .001), and total cholesterol (DID = -0.47; P = .004) targets. Documented microalbumin tests, aspirin prescription, and eye and foot exams increased more. Thus, DMF use was associated with smaller gains in achieving evidence-based targets, but greater improvement in documented delivery of care. © 2013 by the American College of Medical Quality.

A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

PubMed Central

Veigas, Bruno; Águas, Hugo; Fortunato, Elvira; Martins, Rodrigo; Baptista, Pedro Viana; Igreja, Rui

2017-01-01

Digital microfluidics (DMF) arises as the next step in the fast-evolving field of operation platforms for molecular diagnostics. Moreover, isothermal schemes, such as loop-mediated isothermal amplification (LAMP), allow for further simplification of amplification protocols. Integrating DMF with LAMP will be at the core of a new generation of detection devices for effective molecular diagnostics at point-of-care (POC), providing simple, fast, and automated nucleic acid amplification with exceptional integration capabilities. Here, we demonstrate for the first time the role of coupling DMF and LAMP, in a dedicated device that allows straightforward mixing of LAMP reagents and target DNA, as well as optimum temperature control (reaction droplets undergo a temperature variation of just 0.3 °C, for 65 °C at the bottom plate). This device is produced using low-temperature and low-cost production processes, adaptable to disposable and flexible substrates. DMF-LAMP is performed with enhanced sensitivity without compromising reaction efficacy or losing reliability and efficiency, by LAMP-amplifying 0.5 ng/µL of target DNA in just 45 min. Moreover, on-chip LAMP was performed in 1.5 µL, a considerably lower volume than standard bench-top reactions. PMID:29144379

The Influence of Insulin Dependent Diabetes Mellitus on Dental Caries and Salivary Flow

PubMed Central

Gupta, V. K.; Malhotra, Seema; Sharma, Vasuda; Hiremath, S. S.

2014-01-01

Objective. To assess whether or not there was any change in the dental caries and rate of salivary flow of patients with Insulin Dependent Diabetes Mellitus (IDDM) and the contribution of salivary flow to caries risk in IDDM. Setting. Department of Endocrinology, MS Ramaiah Hospital, Bangalore, India. Design. A comparative cross-sectional descriptive type. Materials and Methods. The sample consisted of two groups: 140 diabetic group (mean age 14.8 yr) and 140 nondiabetic group (mean age 13.7 yr). Dental caries by dmf(t) and dmf(s) indices for primary dentition and DMF(T) and DMF(S) indices was used in permanent dentition to assess the dental caries experience. Both stimulated and unstimulated salivary flow rate were assessed after collection of saliva. Results. In diabetic group 76% had carious lesion and in nondiabetic group 85.3% had carious lesion. Diabetics have lower mean DMFT, DMFS, dmft, and dmfs compared to the nondiabetic group. Diminished unstimulated and stimulated salivary flow rate in diabetic than nondiabetic group. Conclusions. The findings obtained conclude that even though there was reduced salivary flow rate in diabetic group the caries prevalence was low. PMID:26464864

The Influence of Insulin Dependent Diabetes Mellitus on Dental Caries and Salivary Flow.

PubMed

Gupta, V K; Malhotra, Seema; Sharma, Vasuda; Hiremath, S S

2014-01-01

Objective. To assess whether or not there was any change in the dental caries and rate of salivary flow of patients with Insulin Dependent Diabetes Mellitus (IDDM) and the contribution of salivary flow to caries risk in IDDM. Setting. Department of Endocrinology, MS Ramaiah Hospital, Bangalore, India. Design. A comparative cross-sectional descriptive type. Materials and Methods. The sample consisted of two groups: 140 diabetic group (mean age 14.8 yr) and 140 nondiabetic group (mean age 13.7 yr). Dental caries by dmf(t) and dmf(s) indices for primary dentition and DMF(T) and DMF(S) indices was used in permanent dentition to assess the dental caries experience. Both stimulated and unstimulated salivary flow rate were assessed after collection of saliva. Results. In diabetic group 76% had carious lesion and in nondiabetic group 85.3% had carious lesion. Diabetics have lower mean DMFT, DMFS, dmft, and dmfs compared to the nondiabetic group. Diminished unstimulated and stimulated salivary flow rate in diabetic than nondiabetic group. Conclusions. The findings obtained conclude that even though there was reduced salivary flow rate in diabetic group the caries prevalence was low.

Development and validation of an instrument to assess future orientation and resilience in adolescence.

PubMed

Di Maggio, Ilaria; Ginevra, Maria Cristina; Nota, Laura; Soresi, Salvatore

2016-08-01

The study is aimed at providing the development and initial validation of the Design My Future (DMF), which may be administered in career counseling and research activities to assess adolescents' future orientation and resilience. Two studies with two independent samples of Italian adolescents were conducted to examine psychometric requisites of DMF. Specifically, in the first study, after developing items and examined the content validity, the factorial structure, reliability and discriminant validity of the DMF were tested. In the second study, the measurement invariance across gender, conducing a sequence of nested CFA models, was evaluated. Results showed good psychometric support for the instrument with Italian adolescents. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Theoretical insight into the binding energy and detonation performance of ε-, γ-, β-CL-20 cocrystals with β-HMX, FOX-7, and DMF in different molar ratios, as well as electrostatic potential.

PubMed

Feng, Rui-Zhi; Zhang, Shu-Hai; Ren, Fu-de; Gou, Rui-Jun; Gao, Li

2016-06-01

Molecular dynamics method was employed to study the binding energies on the selected crystal planes of the ε-, γ-, β-conformation 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (ε-, γ-, β-CL-20) cocrystal explosives with 1,1-diamino-2,2-dinitroethylene (FOX-7), 1,3,5,7-tetranitro- 1,3,5,7-tetrazacyclooctane with β-conformation (β-HMX) and N,N-dimethylformamide (DMF) in different molar ratios. The oxygen balance, density, detonation velocity, detonation pressure, and surface electrostatic potential were analyzed. The results indicate that the binding energies E b (*) and stabilities are in the order of 1:1 > 2:1 > 3:1 > 5:1 > 8:1 (CL-20:FOX-7/β-HMX/DMF). The values of E b (*) and stabilities of the energetic-nonenergetic CL-20/DMF cocrystals are far larger than those of the energetic-energetic CL-20/FOX-7 and CL-20/β-HMX, and those of CL-20/β-HMX are the smallest. For CL-20/FOX-7 and CL-20/β-HMX, the largest E b (*) appears in the cocrystals with the 1:1, 1:2 or 1:3 molar ratio, and the stabilities of the cocrystals with the excess ratio of CL-20 are weaker than those in the cocrystals with the excess ratio of FOX-7 or β-HMX. In CL-20/FOX-7, CL-20 prefers adopting the γ-form, and ε-CL-20 is the preference in CL-20/β-HMX, and ε-CL-20 and β-CL-20 can be found in CL-20/DMF. The CL-20/FOX-7 and CL-20/β-HMX cocrystals with low molar ratios can meet the requirements of low sensitive high energetic materials. Surface electrostatic potential reveals the nature of the sensitivity change upon the cocrystal formation. Graphical Abstract MD method was employed to study the binding energies on the selected crystal planes in the ε-, γ-, β-CL-20 cocrystals with FOX-7, β-HMX and DMF in different molar ratios. Surface electrostatic potential reveals the nature of the sensitivity change in cocrystals.

Efficient photocatalytic degradation of gaseous N,N-dimethylformamide in tannery waste gas using doubly open-ended Ag/TiO2 nanotube array membranes

NASA Astrophysics Data System (ADS)

Zhao, Yang; Ma, Lin; Chang, Wenkai; Huang, Zhiding; Feng, Xugen; Qi, Xiaoxia; Li, Zenghe

2018-06-01

Gaseous N,N-dimethylformamide (DMF), typical volatile organic compound exhausted from manufacturing factories, may damage the health of workers under long-term exposure even at low levels. The defined geometry, porous surface and highly ordered channels make the free-standing anodic TiO2 nanotube (TiNT) arrays particularly suitable for applications of practical air purification by flow-through photocatalysis. In the present work, crystallized doubly open-ended Ag/TiNT array membranes were designed and prepared by employing a lift-off process based on an anodization-annealing-anodization-etching sequence, followed by uniform Ag nanoparticles decoration. For the photocatalytic degradation of gaseous DMF at low concentration levels close to that found in realistic pollutant air, an analytical methodology for the monitoring and determination of degradation process was developed based on the coupling of headspace sampling with gas chromatography mass spectrometry (HS-GC-MS). The doubly open-ended Ag/TiNT arrays exhibited higher removal efficiency of gaseous DMF from air compared with conventional bottom-closed Ag/TiNT arrays and pure bottomless TiNT arrays. These results indicated that the photocatalytic properties of TiNT arrays were improved with the open-bottom morphology and the Ag nanoparticles decoration. Based on the analysis with GC-MS and high performance ion chromatography (HPIC), it was found that demethylation is the main pathway of DMF degradation in photocatalytic reactions. Furthermore, decontamination of actual polluted tannery waste gas collected in leather factory proved that the photocatalysis on doubly open-ended Ag/TiNT array membrane is an efficient way and a promising application to treat air contaminated by DMF despite the complexity of various volatile organic compounds.

A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay

PubMed Central

Tsai, Po-Yen; Lee, I-Chin; Hsu, Hsin-Yun; Huang, Hong-Yuan; Fan, Shih-Kang; Liu, Cheng-Hsien

2016-01-01

Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications. PMID:26858807

Formulation, Casting, and Evaluation of Paraffin-Based Solid Fuels Containing Energetic and Novel Additives for Hybrid Rockets

NASA Technical Reports Server (NTRS)

Larson, Daniel B.; Desain, John D.; Boyer, Eric; Wachs, Trevor; Kuo, Kenneth K.; Borduin, Russell; Koo, Joseph H.; Brady, Brian B.; Curtiss, Thomas J.; Story, George

2012-01-01

This investigation studied the inclusion of various additives to paraffin wax for use in a hybrid rocket motor. Some of the paraffin-based fuels were doped with various percentages of LiAlH4 (up to 10%). Addition of LiAlH4 at 10% was found to increase regression rates between 7 - 10% over baseline paraffin through tests in a gaseous oxygen hybrid rocket motor. Mass burn rates for paraffin grains with 10% LiAlH4 were also higher than those of the baseline paraffin. RDX was also cast into a paraffin sample via a novel casting process which involved dissolving RDX into dimethylformamide (DMF) solvent and then drawing a vacuum on the mixture of paraffin and RDX/DMF in order to evaporate out the DMF. It was found that although all DMF was removed, the process was not conducive to generating small RDX particles. The slow boiling generated an inhomogeneous mixture of paraffin and RDX. It is likely that superheating the DMF to cause rapid boiling would likely reduce RDX particle sizes. In addition to paraffin/LiAlH4 grains, multi-walled carbon nanotubes (MWNT) were cast in paraffin for testing in a hybrid rocket motor, and assorted samples containing a range of MWNT percentages in paraffin were imaged using SEM. The fuel samples showed good distribution of MWNT in the paraffin matrix, but the MWNT were often agglomerated, indicating that a change to the sonication and mixing processes were required to achieve better uniformity and debundled MWNT. Fuel grains with MWNT fuel grains had slightly lower regression rate, likely due to the increased thermal conductivity to the fuel subsurface, reducing the burning surface temperature.

The biological response to laser-aided direct metal-coated Titanium alloy (Ti6Al4V)

PubMed Central

Shin, T.; Lim, D.; Kim, Y. S.; Kim, S. C.; Jo, W. L.

2018-01-01

Objectives Laser-engineered net shaping (LENS) of coated surfaces can overcome the limitations of conventional coating technologies. We compared the in vitro biological response with a titanium plasma spray (TPS)-coated titanium alloy (Ti6Al4V) surface with that of a Ti6Al4V surface coated with titanium using direct metal fabrication (DMF) with 3D printing technologies. Methods The in vitro ability of human osteoblasts to adhere to TPS-coated Ti6Al4V was compared with DMF-coating. Scanning electron microscopy (SEM) was used to assess the structure and morphology of the surfaces. Biological and morphological responses to human osteoblast cell lines were then examined by measuring cell proliferation, alkaline phosphatase activity, actin filaments, and RUNX2 gene expression. Results Morphological assessment of the cells after six hours of incubation using SEM showed that the TPS- and DMF-coated surfaces were largely covered with lamellipodia from the osteoblasts. Cell adhesion appeared similar in both groups. The differences in the rates of cell proliferation and alkaline phosphatase activities were not statistically significant. Conclusions The DMF coating applied using metal 3D printing is similar to the TPS coating, which is the most common coating process used for bone ingrowth. The DMF method provided an acceptable surface structure and a viable biological surface. Moreover, this method is automatable and less complex than plasma spraying. Cite this article: T. Shin, D. Lim, Y. S. Kim, S. C. Kim, W. L. Jo, Y. W. Lim. The biological response to laser-aided direct metal-coated Titanium alloy (Ti6Al4V). Bone Joint Res 2018;7:357–361. DOI: 10.1302/2046-3758.75.BJR-2017-0222.R1. PMID:29922456

Emissions of amides (N,N-dimethylformamide and formamide) and other obnoxious volatile organic compounds from different mattress textile products.

PubMed

Kim, Ki-Hyun; Pandey, Sudhir K; Kim, Yong-Hyun; Sohn, Jong Ryeul; Oh, J-M

2015-04-01

The emission rates of N,N-dimethylformamide (DMF), formamide (FAd), and certain hazardous volatile organic compounds (VOCs) were measured from seventeen mattress textile samples with four different raw material types: polyurethane (PU: n=3), polyester/polyethylene (PE: n=7), ethylene vinyl acetate (EV: n=3), and polyvinyl chloride (PC: n=4). To simulate the emissions in a heated room during winter season, measurements were made under temperature-controlled conditions, i.e., 50°C by using a mini-chamber system made of a midget impinger. Comparison of the data indicates that the patterns were greatly distinguished between DMF and FAd. PU products yielded the highest mean emission rates of DMF (2940 μg m(-2)h(-1): n=3) followed by PE (325 μg m(-2)h(-1): n=7), although its emission was not seen from other materials (EV and PC). In contrast, the pattern of FAd emission was moderately reversed from that of DMF: EV>PC>PE>PU. The results of our analysis confirm that most materials used for mattress production have the strong potential to emit either DMF or FAd in relatively large quantities while in use in children׳s care facilities, especially in winter months. Moreover, it was also observed that an increase in temperature (25°C to 50°C) had a significant impact on the emission rate of FAd and other hazardous VOCs. In addition to the aforementioned amides, the study revealed significant emissions of a number of hazardous VOCs, such as aromatic and carbonyl compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

DMF, but not other fumarates, inhibits NF-κB activity in vitro in an Nrf2-independent manner.

PubMed

Gillard, Geoffrey O; Collette, Brian; Anderson, John; Chao, Jianhua; Scannevin, Robert H; Huss, David J; Fontenot, Jason D

2015-06-15

Fumarate-containing pharmaceuticals are potent therapeutic agents that influence multiple cellular pathways. Despite proven clinical efficacy, there is a significant lack of data that directly defines the molecular mechanisms of action of related, yet distinct fumarate compounds. We systematically compared the impact of dimethyl fumarate (DMF), monomethyl fumarate (MMF) and a mixture of monoethyl fumarate salts (Ca(++), Mg(++), Zn(++); MEF) on defined cellular responses. We demonstrate that DMF inhibited NF-κB-driven cytokine production and nuclear translocation of p65 and p52 in an Nrf2-independent manner. Equivalent doses of MMF and MEF did not affect NF-κB signaling. These results highlight a key difference in the biological impact of related, yet distinct fumarate compounds. Copyright © 2015. Published by Elsevier B.V.

Regioselective SN2 reactions for rapid syntheses of azido-inositols by one-pot sequence-specific nucleophilysis.

PubMed

Ravi, Arthi; Hassan, Syed Zahid; Vanikrishna, Ajithkumar N; Sureshan, Kana M

2017-04-04

Triflates of myo-inositol undergo facile solvolysis in DMSO and DMF yielding S N 2 products substituted with O-nucleophiles; DMF showed slower kinetics. Axial O-triflate undergoes faster substitution than equatorial O-triflate. By exploiting this difference in kinetics, solvent-tuning and sequence-controlled nucleophilysis, rapid synthesis of three azido-inositols of myo-configuration from myo-inositol itself has been achieved.

Synthesis and characterization of porous silicon as hydroxyapatite host matrix of biomedical applications.

PubMed

Dussan, A; Bertel, S D; Melo, S F; Mesa, F

2017-01-01

In this work, porous-silicon samples were prepared by electrochemical etching on p-type (B-doped) Silicon (Si) wafers. Hydrofluoric acid (HF)-ethanol (C2H5OH) [HF:Et] and Hydrofluoric acid (HF)-dimethylformamide (DMF-C3H7NO) [HF:DMF] solution concentrations were varied between [1:2]-[1:3] and [1:7]-[1:9], respectively. Effects of synthesis parameters, like current density, solution concentrations, reaction time, on morphological properties were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements. Pore sizes varying from 20 nm to micrometers were obtained for long reaction times and [HF:Et] [1:2] concentrations; while pore sizes in the same order were observed for [HF:DMF] [1:7], but for shorter reaction time. Greater surface uniformity and pore distribution was obtained for a current density of around 8 mA/cm2 using solutions with DMF. A correlation between reflectance measurements and pore size is presented. The porous-silicon samples were used as substrate for hydroxyapatite growth by sol-gel method. X-ray diffraction (XRD) and SEM were used to characterize the layers grown. It was found that the layer topography obtained on PS samples was characterized by the evidence of Hydroxyapatite in the inter-pore regions and over the surface.

Synthesis and characterization of porous silicon as hydroxyapatite host matrix of biomedical applications

PubMed Central

Dussan, A.; Bertel, S. D.; Melo, S. F.

2017-01-01

In this work, porous-silicon samples were prepared by electrochemical etching on p-type (B-doped) Silicon (Si) wafers. Hydrofluoric acid (HF)-ethanol (C2H5OH) [HF:Et] and Hydrofluoric acid (HF)-dimethylformamide (DMF-C3H7NO) [HF:DMF] solution concentrations were varied between [1:2]—[1:3] and [1:7]—[1:9], respectively. Effects of synthesis parameters, like current density, solution concentrations, reaction time, on morphological properties were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements. Pore sizes varying from 20 nm to micrometers were obtained for long reaction times and [HF:Et] [1:2] concentrations; while pore sizes in the same order were observed for [HF:DMF] [1:7], but for shorter reaction time. Greater surface uniformity and pore distribution was obtained for a current density of around 8 mA/cm2 using solutions with DMF. A correlation between reflectance measurements and pore size is presented. The porous-silicon samples were used as substrate for hydroxyapatite growth by sol-gel method. X-ray diffraction (XRD) and SEM were used to characterize the layers grown. It was found that the layer topography obtained on PS samples was characterized by the evidence of Hydroxyapatite in the inter-pore regions and over the surface. PMID:28291792

Preferential solvation of Brooker's merocyanine in binary solvent mixtures composed of formamides and hydroxylic solvents.

PubMed

Bevilaqua, Tharly; da Silva, Domingas C; Machado, Vanderlei G

2004-03-01

The ET polarity values of 4-[(1-methyl-4(1H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one (Brooker's merocyanine) were collected in mixed-solvent systems comprising a formamide [N,N-dimethylformamide (DMF), N-methylformamide (NMF) or formamide (FA)] and a hydroxylic (water, methanol, ethanol, propan-2-ol or butan-1-ol) solvent. Binary mixtures involving DMF and the other formamides (NMF and FA) as well as NMF and FA were also studied. These data were employed in the investigation of the preferential solvation (PS) of the probe. Each solvent system was analyzed in terms of both solute-solvent and solvent-solvent interactions. These latter interactions were responsible for the synergism observed in many binary mixtures. This synergistic behaviour was observed for DMF-propan-2-ol, DMF-butan-1-ol, FA-methanol, FA-ethanol and for the mixtures of the alcohols with NMF. All data were successfully fitted to a model based on solvent-exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. The results suggest that both hydrogen bonding and solvophobic interactions contribute to the formation of the solvent complexes responsible for the observed synergistic effects in the PS of the dye.

Proton conducting gel polyelectrolytes based on 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) copolymers with polyfunctional monomers. Part I. Anhydrous systems

NASA Astrophysics Data System (ADS)

Zygadło-Monikowska, Ewa; Florjańczyk, Zbigniew; Wielgus-Barry, Edyta; Paśniewski, Jarosław

The synthesis of crosslinked gel polyelectrolytes in polar aprotic solvents such as dimethylformamide (DMF) and a DMF and propylene carbonate (PC) mixture has been carried out in the copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and polyfunctional monomers. N, N‧-Methylene-bis-acrylamide, trioxyethylene dimethacrylate (M n ∼ 330) and trimethylolpropane ethoxylate (14/3 EO/OH) triacrylate were used as crosslinking monomers. The reactions were initiated thermally or by UV irradiation in the presence of Irgacure 184 or methyl benzoin ether. The crosslinking monomer was used in an amount of 0.5-13 wt.%. The effect of the type and concentration of the polyfunctional comonomer and type of solvent on the optical (color, transparency) and mechanical properties as well as the ability to conduct electrical charges have been studied. The application of a DMF and PC mixture enables to obtain transparent systems of good mechanical properties and high ambient temperature ionic conductivity of the order of 10 -3 to 10 -4 S cm -1, slightly lowered as compared with that of gels comprising DMF alone. The conducting properties of crosslinked gels have been compared with that of the AMPSA homopolymer solutions in analogous solvents.

Building bio-assays with magnetic particles on a digital microfluidic platform.

PubMed

Kokalj, Tadej; Pérez-Ruiz, Elena; Lammertyn, Jeroen

2015-09-25

Digital microfluidics (DMF) has emerged as a promising liquid handling technology for a variety of applications, demonstrating great potential both in terms of miniaturization and automation. DMF is based on the manipulation of discrete, independently controllable liquid droplets, which makes it highly reconfigurable and reprogrammable. One of its most exclusive advantages, compared to microchannel-based microfluidics, is its ability to precisely handle solid nano- and microsized objects, such as magnetic particles. Magnetic particles have become very popular in the last decade, since their high surface-to-volume ratio and the possibility to magnetically separate them from the matrix make them perfect suitable as a solid support for bio-assay development. The potential of magnetic particles in DMF-based bio-assays has been demonstrated for various applications. In this review we discuss the latest developments of magnetic particle-based DMF bio-assays with the aim to present, identify and analyze the trends in the field. We also discuss the state-of-the art of device integration, current status of commercialization and issues that still need to be addressed. With this paper we intend to stimulate researchers to exploit and unveil the potential of these exciting tools, which will shape the future of modern biochemistry, microbiology and biomedical diagnostics. Copyright © 2015 Elsevier B.V. All rights reserved.

[Oral health status evaluation of pre-school children: longitudinal epidemiologic study (1993-1994), Córdoba, Argentina].

PubMed

Battellino, L J; Cornejo, L S; Dorronsoro de Cattoni, S T; Luna Maldonado de Yankilevich, E R; Calamari, S E; Azcura, A I; Virga, C

1997-06-01

A one-year longitudinal survey was carried out on a sample of the Cordoba City 4-year old kindergarten population (n = 820); so as to determine the role of several variables upon the incidence of caries. The dmf-t, dmf-s, oral hygiene and oral health indexes as well as incidence rates and caries relative risks of caries were inversely related to the socioeconomic level (SEL) of the children involved. Thus in the SEL III (typical proletariat, non-typical proletariat and sub-proletariat) children, the relative risk of caries was almost five times higher (RR = 4.9) than in the SEL I (entrepreneureal and managerial bourgeoisie) children. In SEL I, almost all new lesions occurred on smooth surfaces (61.2%), while in SEL III the molar occlusal faces were mainly affected (66.3%). Daily sugar intake was higher in SEL III children but experience of caries showed poor correlation to the amount (r = 0.40) and frequency (r = 0.52) of carbohydrate intake. No significant interlevel differences were observed in the biochemical salivary parameters analyzed. Assisted toothbrushing and fluoride topications strongly lowered the incidence of caries among SEL III children, also making the corresponding rates fall almost to SEL I values (0.31, 0.23 and 0.22 vs. 0.21). In conclusion, SEL III children should be treated prophylactically with effective preventive measures, because of their susceptibility to caries. Such preventive measures include assisted toothbrushing and fluoride topications.

Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

NASA Astrophysics Data System (ADS)

Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

2014-01-01

The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

Long-term effects of chemotherapy on dental status of children cancer survivors.

PubMed

Nemeth, Orsolya; Hermann, Peter; Kivovics, Peter; Garami, Miklos

2013-04-01

The aim of this study was to investigate the long-term effects of chemotherapy on the dental and gingival health and dental disturbance parameters of children cancer survivors. Thirty-eight children (mean age 12.2 ± 0.5 years) who underwent chemotherapy at 4.29 ± 1.71 years of age formed the study group. Forty age- and gender-matched healthy children with a similar socioeconomic background served as controls. Subjects' caries status (number of decayed, missing, or filled permanent teeth [DMF-T]) was recorded according to World Health Organization criteria. Subjects' periodontal status was recorded according to the community periodontal index system. Radiographic dental examination was used to analyze dental malformations. DMF-T, D-T (number of decayed permanent teeth), and F-T (number of filled permanent teeth) were significantly higher in the study group compared to the controls (4.61 ± 3.71, 3.97 ± 4.45, respectively, and 0.58 ± 0.14 vs. 2.21 ± 1.01, 0.84 ± 1.82, and 1.18 ±1.07, respectively. The most frequent dental disturbances were root malformation (52.6%) and agenesis (47.4%). According to our examination dental status of long-term survivors is worse than in controls. Hence proper oral hygiene for children cancer survivors (CCS) is critical. In order to meet the need for dental care in CCS health authorities are encouraged to revitalize the dental services Long-term follow-up of CCS is necessary to monitor their dental growth and oral health.

Synthesis and crystalline properties of CdS incorporated polyvinylidene fluoride (PVDF) composite film

NASA Astrophysics Data System (ADS)

Patel, Arunendra Kumar; Sunder, Aishwarya; Mishra, Shweta; Bajpai, Rakesh

2018-05-01

This paper gives an insight on the synthesis and crystalline properties of Polyvinylidene Fluoride (PVDF) (host matrix) composites impregnated with Cadmium Sulphide (CdS) using Dimethyl formamide (DMF) as the base, prepared by the well known solvent casting technique. The effect of doping concentration of CdS in to the PVDF matrix was studied using X-ray diffraction technique. The structural properties like crystallinity Cr, interplanar distance d, average size of the crystalline region (D), and average inter crystalline separation (R) have been estimated for the developed composite. The crystallinity index, crystallite size and inter crystalline separation is increasing with increase in the concentration of CdS in to the PVDF matrix while the interplanar distance d is decreasing.

Crosslinking hydroxylated reduced graphene oxide with RAFT-CTA: A nano-initiator for preparation of well-defined amino acid-based polymer nanohybrids.

PubMed

Namvari, Mina; Biswas, Chandra S; Wang, Qiao; Liang, Wenlang; Stadler, Florian J

2017-10-15

Here, we demonstrate a novel reversible addition-fragmentation chain transfer agent (RAFT-CTA)-modified reduced graphene oxide nanosheets (CTA-rGONSs) by crosslinking rGONSs with a RAFT-CTA via esterification reaction. These nano CTA-rGONSs were used to polymerize a hydrophobic amino acid-based methacrylamide (N-acryloyl-l-phenylalanine methyl ester) monomer with different monomer/initiator ratios. Thermogravimetric analysis showed that the polymer-graphene composites were thermally more stable than GO itself. M n of the polymers increased with increasing monomer/initiator ratio, while the polydispersity index decreased, indicating controlled polymerization. The composites were stable in DMF even after two months. Copyright © 2017 Elsevier Inc. All rights reserved.

Fabrication and characterization of poly(L-lactic acid) gels induced by fibrous complex crystallization with solvents

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

Matsuda, Yasuhiro; Fukatsu, Akinobu; Wang, Yangyang

2014-01-01

Complex crystal induced gelation of poly(L-lactic acid) (PLLA) solutions was studied for a series of solvents, including N,N-dimethylformamide (DMF). By cooling the solutions prepared at elevated temperatures, PLLA gels were produced in solvents that induced complex crystals ( -crystals) with PLLA. Fibrous structure of PLLA in the gel with DMF was observed by polarizing optical microscopy, field emission electron microscopy, and atomic force microscopy. Upon heating, the crystal form of PLLA in the DMF gel changed from -crystal to a-crystal, the major crystal form in common untreated PLLA films, but the morphology and high elastic modulus of the gel remainedmore » until the a-crystal dissolved at higher temperature. In addition, a solvent exchanging method was developed, which allowed PLLA gels to be prepared in other useful solvents that do not induce -crystals without losing the morphology and mechanical properties.« less

The putative interplay between DJ-1/NRF2 and Dimethyl Fumarate: A potentially important pharmacological target.

PubMed

Vavougios, George; Zarogiannis, Sotirios G; Doskas, Triantafylos

2018-04-01

Recent research has outlined that Dimethyl Fumarate (DMF) functions as a gene regulator via multiple pathways, critical among which is the NRF2 cytoprotective cascade. PARK7/DJ-1 is a multifunctional protein that acts as a redox sensor and effector of multiple cytoprotective pathways, including NRF2. Specifically, it prevents the association of NRF2 with its inhibitor KEAP1, allowing NRF2 to enter the nucleus and mediate cytoprotective and antioxidant cascades. It is our hypothesis that while the NRF2-KEAP1 inhibitory complex is reported the main pharmacological target for DMF's NRF dependent functions, no study to date has explored the effects of DMF on DJ-1's expression, and vice-versa, the possibility of a regulatory inadequacy in the upstream, oxidant-responsive DJ-1 activator of the NRF2 cascade. Copyright © 2018 Elsevier B.V. All rights reserved.

Solvent-induced assembly of two helical Eu(III) metal-organic frameworks and fluorescence sensing activities towards nitrobenzene and Cu2+ ions

NASA Astrophysics Data System (ADS)

Ma, Ranran; Chen, Zhiwei; Wang, Suna; Yao, Qingxia; Li, Yunwu; Lu, Jing; Li, Dacheng; Dou, Jianmin

2017-08-01

Two helical Eu(III) metal-organic frameworks, namely, {[Eu(L)(DMF)(H2O)]·0.5DMF}n (1) and [Eu(L)(DEF)(H2O)]n (2) (H3L=3,5-bis(2-carboxylphenoxy)benzoic acid, DMF=N,N-dimethylformamide, DEF=N,N-diethylformamide), have been solvothermally synthesized in different solvents, respectively. Both complexes possess helical structures through the connectivity of Eu atoms and phenolic-oxygen containing branches of the flexible multicarboxylate ligand. Based on different helices, these two complexes exhibited hexagonal and tetragonal channels, respectively. Both complexes possess (3,6)-connected (4.62)2(42.610.83) topology but with different long Schlafli symbol. The solvent plays an important role in the formation of the final frameworks. Both complexes can sensitively and selectively detect nitrobenzene and Cu2+ ions.

Oral soft tissue disorders are associated with gastroesophageal reflux disease: retrospective study.

PubMed

Watanabe, Masaaki; Nakatani, Eiji; Yoshikawa, Hiroo; Kanno, Takahiro; Nariai, Yoshiki; Yoshino, Aya; Vieth, Michael; Kinoshita, Yoshikazu; Sekine, Joji

2017-08-07

Dental erosion (DE), one of oral hard tissue diseases, is one of the extraoesophageal symptoms defined as the Montreal Definition and Classification of gastroesophageal reflux disease (GERD). However, no study evaluated the relationship between GERD and oral soft tissues. We hypothesized that oral soft tissue disorders (OSTDs) would be related to GERD. The study aimed to investigate the association OSTDs and GERD. GERD patients (105 cases), older and younger controls (25 cases each) were retrospectively examined for oral symptoms, salivary flow volume (Saxon test), swallowing function (repetitive saliva swallowing test [RSST]), teeth (decayed, missing, and filled [DMF] indices), and soft tissues (as evaluation of OSTDs, gingivitis; papillary, marginal, and attached [PMA] gingival indexes, simplified oral hygiene indices [OHI-S], and inflammatory oral mucosal regions). Clinical histories, which included body mass index [BMI], the existence of alcohol and tobacco use, and bruxism, were also investigated. A P value of <0.05 was defined as statistically significant. GERD patients, older and younger controls participated and aged 66.4 ± 13.0, 68.3 ± 8.2 and 28.7 ± 2.6 years old, respectively. The most common oral symptom in the GERD patients was oral dryness. Salivary flow volume and swallowing function in the GERD patients were significantly lower than in either of the controls (all P < 0.05). Inflammatory oral mucosal regions were found only in the GERD patients. The DMF indices, as a measure of dental caries, in the GERD patients were higher than in the younger controls (P < 0.001), but lower than in the older controls (P = 0.033). The PMA gingival indexes, as a measurement for gingival inflammation, and OHI-S, as a measure for oral hygiene, in the GERD patients were significantly higher than in either of the controls (all P < 0.05). Though no significant differences in BMI, the existence of alcohol and tobacco use were found, bruxism, as an exacerbation factor of periodontal disease, in the GERD patients was significantly more frequent than in either control group (P = 0.041). OSTDs were associated with GERD, which was similar to the association between DE and GERD.

Combustion chemistry and flame structure of furan group biofuels using molecular-beam mass spectrometry and gas chromatography – Part III: 2,5-Dimethylfuran

PubMed Central

Togbé, Casimir; Tran, Luc-Sy; Liu, Dong; Felsmann, Daniel; Oßwald, Patrick; Glaude, Pierre-Alexandre; Sirjean, Baptiste; Fournet, René; Battin-Leclerc, Frédérique; Kohse-Höinghaus, Katharina

2013-01-01

This work is the third part of a study focusing on the combustion chemistry and flame structure of furan and selected alkylated derivatives, i.e. furan in Part I, 2-methylfuran (MF) in Part II, and 2,5-dimethylfuran (DMF) in the present work. Two premixed low-pressure (20 and 40 mbar) flat argon-diluted (50%) flames of DMF were studied with electron-ionization molecular-beam mass spectrometry (EI-MBMS) and gas chromatography (GC) under two equivalence ratios (φ=1.0 and 1.7). Mole fractions of reactants, products, and stable and radical intermediates were measured as a function of the distance to the burner. Kinetic modeling was performed using a reaction mechanism that was further developed in the present series, including Part I and Part II. A reasonable agreement between the present experimental results and the simulation is observed. The main reaction pathways of DMF consumption were derived from a reaction flow analysis. Also, a comparison of the key features for the three flames is presented, as well as a comparison between these flames of furanic compounds and those of other fuels. An a priori surprising ability of DMF to form soot precursors (e.g. 1,3-cyclopentadiene or benzene) compared to less substituted furans and to other fuels has been experimentally observed and is well explained in the model. PMID:24518851

Combustion chemistry and flame structure of furan group biofuels using molecular-beam mass spectrometry and gas chromatography - Part III: 2,5-Dimethylfuran.

PubMed

Togbé, Casimir; Tran, Luc-Sy; Liu, Dong; Felsmann, Daniel; Oßwald, Patrick; Glaude, Pierre-Alexandre; Sirjean, Baptiste; Fournet, René; Battin-Leclerc, Frédérique; Kohse-Höinghaus, Katharina

2014-03-01

This work is the third part of a study focusing on the combustion chemistry and flame structure of furan and selected alkylated derivatives, i.e. furan in Part I, 2-methylfuran (MF) in Part II, and 2,5-dimethylfuran (DMF) in the present work. Two premixed low-pressure (20 and 40 mbar) flat argon-diluted (50%) flames of DMF were studied with electron-ionization molecular-beam mass spectrometry (EI-MBMS) and gas chromatography (GC) under two equivalence ratios (φ=1.0 and 1.7). Mole fractions of reactants, products, and stable and radical intermediates were measured as a function of the distance to the burner. Kinetic modeling was performed using a reaction mechanism that was further developed in the present series, including Part I and Part II. A reasonable agreement between the present experimental results and the simulation is observed. The main reaction pathways of DMF consumption were derived from a reaction flow analysis. Also, a comparison of the key features for the three flames is presented, as well as a comparison between these flames of furanic compounds and those of other fuels. An a priori surprising ability of DMF to form soot precursors (e.g. 1,3-cyclopentadiene or benzene) compared to less substituted furans and to other fuels has been experimentally observed and is well explained in the model.

Immobilization of silver nanoparticles in Zr-based MOFs: induction of apoptosis in cancer cells

NASA Astrophysics Data System (ADS)

Han, Congcong; Yang, Jian; Gu, Jinlou

2018-03-01

Silver nanoparticles (AgNPs) are a potential class of nanomaterial for antibiosis and chemotherapeutic effects against human carcinoma cells. However, the DNA-damaging ability of free AgNPs pose the critical issues in their biomedical applications. Herein, we demonstrated a facile method to capture Ag+ ions and reduce them into active AgNPs within Zr-based metal-organic frameworks (MOFs) of UiO-66 with a mild reductant of DMF (AgNPs@UiO-66(DMF)). The average diameters of UiO-66 carriers and AgNPs were facilely controlled to be 140 and 10 nm, respectively. The obtained UiO-66 nanocarriers exhibited excellent biocompatibility and could be effectively endocytosed by cancer cells. Additionally, the AgNPs@UiO-66(DMF) could rapidly release Ag+ ions and efficiently inhibit the growth of cancer cells. The half maximal inhibitory concentration (IC50) values of the encapsulated AgNPs were calculated to be 2.7 and 2.45 μg mL-1 for SMMC-7721 and HeLa cells, respectively, which were much lower than those of free AgNPs in the reported works. Therefore, the developed AgNPs@UiO-66(DMF) not only maintained the therapeutic effect against cancer cells but also reduced the dosage of free AgNPs in chemotherapy treatment. [Figure not available: see fulltext.

Genotoxicity of three food processing contaminants in transgenic mice expressing human sulfotransferases 1A1 and 1A2 as assessed by the in vivo alkaline single cell gel electrophoresis assay

PubMed Central

Høie, Anja Hortemo; Svendsen, Camilla; Brunborg, Gunnar; Glatt, Hansruedi; Alexander, Jan; Meinl, Walter

2015-01-01

The food processing contaminants 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), 5‐hydroxymethylfurfural (HMF) and 2,5 dimethylfuran (DMF) are potentially both mutagenic and carcinogenic in vitro and/or in vivo, although data on DMF is lacking. The PHIP metabolite N‐hydroxy‐PhIP and HMF are bioactivated by sulfotransferases (SULTs). The substrate specificity and tissue distribution of SULTs differs between species. A single oral dose of PhIP, HMF or DMF was administered to wild‐type (wt) mice and mice expressing human SULT1A1/1A2 (hSULT mice). DNA damage was studied using the in vivo alkaline single cell gel electrophoresis (SCGE) assay. No effects were detected in wt mice. In the hSULT mice, PhIP and HMF exposure increased the levels of DNA damage in the liver and kidney, respectively. DMF was not found to be genotoxic. The observation of increased DNA damage in hSULT mice compared with wt mice supports the role of human SULTs in the bioactivation of N‐hydroxy‐PhIP and HMF in vivo. Environ. Mol. Mutagen. 56:709–714, 2015. © 2015 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc. PMID:26270892

Crystal growth, differential gas adsorption, high thermal stability, and reversible coordination of two new barium-organic frameworks, Ba(SBA)(DMF){sub 4} and Ba{sub 2}(BTEC)(H{sub 2}O)

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

Halake, Shobha; Ok, Kang Min, E-mail: kmok@cau.ac.kr

2015-11-15

Single crystals of two barium-organic framework materials, Ba(SBA)(DMF){sub 4} (CAUMOF-15) and Ba{sub 2}(BTEC)(H{sub 2}O) (CAUMOF-16), have been grown through solvothermal reactions (H{sub 2}SBA=4,4′-sulfonyldibenzoic acid and H{sub 4}BTEC=1,2,4,5-benzenetetracarboxylic acid). The crystal structures of the reported frameworks have been determined by single-crystal X-ray diffraction. The materials have been fully characterized by powder X-ray diffraction (PXRD), elemental analyses, Infrared (IR) spectroscopy, and thermogravimetric analyses (TGA). CAUMOF-15 reveals a three-dimensional open-framework that comprises of an inorganic motif with one-dimensional chains and the SBA linkers. CAUMOF-16 shows another three-dimensional backbone consisting of layers of edge-shared BaO{sub 9} and BaO{sub 10} polyhedra, and BTEC pillars. Bothmore » of the 3D frameworks exhibit relatively high thermal stabilities. The PXRD and IR spectral data confirm that CAUMOF-15 and CAUMOF-16 reveal reversible coordinations of the respective solvent molecules, DMF and H{sub 2}O. Gas adsorption properties towards nitrogen, hydrogen, and carbon dioxide have been also investigated. - Graphical abstract: Crystals of two new barium-organic frameworks, Ba(SBA)(DMF){sub 4} and Ba{sub 2}(BTEC)(H{sub 2}O), exhibiting a differential gas adsorption, a high thermal stability, and a reversible coordination of solvent molecules have been grown. - Highlights: • Crystals of two new 3D Ba-MOFs are grown. • The two Ba-MOFs reveal very high thermal stabilities up to ca. 400 °C. • Ba(SBA)(DMF){sub 4} exhibits differential gas adsorption properties. • The two Ba-MOFs show reversible coordination of the solvent molecules.« less

[Microbial community and its activities in canopy- and understory humus of two montane forest types in Ailao Mountains, Northwest China].

PubMed

Liu, Yong-jie; Liu, Wen-yao; Chen, Lin; Zhang, Han-bo; Wang, Gao-sheng

2010-09-01

Mid-montane moist evergreen broadleaved forest (MMF) and top-montane dwarf mossy forest (DMF) are the two major natural forest types in subtropical mountainous area of Ailao Mountains, Northwest China. In this paper, a comparative study was made on the microbial composition, quantity, biochemical activity, metabolic activity, and their seasonal dynamics in the canopy- and understory humus of the two forest types. The composition, quantity, and metabolic activity of the microbes in the canopy humus of dominant tree species in MMF and DMF were also analyzed. In the canopy humus of the two forest types, the amounts of fungi and actinomycetes, microbial biomass C and N, and intensities of nitrogen fixation and cellulose decomposition were significantly higher than those in understory humus. Meanwhile, the amount of cellulose-decomposing microbes (ACDM), cellulose decomposition intensity, microbial biomass C and N, and metabolic activity in the canopy humus of MMF were significantly higher than those of DMF. The amounts of bacteria, fungi, and aerobic nitrogen-fixing bacteria (ANFB) and the metabolic activity in the canopy humus of MMF and DMF were significantly higher in wet season than in dry season, while a contradictory trend was observed on the amount of actinomycetes. No significant difference was observed on the amount of ACDM between wet season and dry season. For the two forest types, the amounts of microbes and their biochemical activities in canopy humus had a larger seasonal variation range than those in understory humus. There was a significant difference in the amounts of the microbes in canopy humus among the dominant tree species in MMF and DMF, especially in wet season. The microbes in canopy humus played important roles in maintaining the biodiversity of epiphytes in the canopy, and in supplying the needed nutrients for the vigorous growth of the epiphytes.

Vapochromic Behaviour of M[Au(CN)2]2-Based Coordination Polymers (M = Co, Ni)

PubMed Central

Lefebvre, Julie; Korčok, Jasmine L.; Katz, Michael J.; Leznoff, Daniel B.

2012-01-01

A series of M[Au(CN)2]2(analyte)x coordination polymers (M = Co, Ni; analyte = dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), pyridine; x = 2 or 4) was prepared and characterized. Addition of analyte vapours to solid M(μ-OH2)[Au(CN)2]2 yielded visible vapochromic responses for M = Co but not M = Ni; the IR νCN spectral region changed in every case. A single crystal structure of Zn[Au(CN)2]2(DMSO)2 revealed a corrugated 2-D layer structure with cis-DMSO units. Reacting a Ni(II) salt and K[Au(CN)2] in DMSO yielded the isostructural Ni[Au(CN)2]2(DMSO)2 product. Co[Au(CN)2]2(DMSO)2 and M[Au(CN)2]2(DMF)2 (M = Co, Ni) complexes have flat 2-D square-grid layer structures with trans-bound DMSO or DMF units; they are formed via vapour absorption by solid M(μ-OH2)[Au(CN)2]2 and from DMSO or DMF solution synthesis. Co[Au(CN)2]2(pyridine)4 is generated via vapour absorption by Co(μ-OH2)[Au(CN)2]2; the analogous Ni complex is synthesized by immersion of Ni(μ-OH2)[Au(CN)2]2 in 4% aqueous pyridine. Similar immersion of Co(μ-OH2)[Au(CN)2]2 yielded Co[Au(CN)2]2(pyridine)2, which has a flat 2-D square-grid structure with trans-pyridine units. Absorption of pyridine vapour by solid Ni(μ-OH2)[Au(CN)2]2 was incomplete, generating a mixture of pyridine-bound complexes. Analyte-free Co[Au(CN)2]2 was prepared by dehydration of Co(μ-OH2)[Au(CN)2]2 at 145 °C; it has a 3-D diamondoid-type structure and absorbs DMSO, DMF and pyridine to give the same materials as by vapour absorption from the hydrate. PMID:22737031

Visible light-induced magnetization change of the cyano-bridged 3 d-4 f heterobimetallic

NASA Astrophysics Data System (ADS)

Li, Guangming; Sato, Osamu; Akitsu, Takashiro; Einaga, Yasuaki

2004-10-01

A visible light-induced magnetization change of the 3d-4f heterometallic, [Nd(DMF)4(H2O)3(μ-NC)Co(CN)5]·H2O (DMF=N,N-dimethylformamide), is observed and described. The plots of χMT versus T of the complex showed that the χMT values, after visible light illumination, were enhanced by about 25% as compared to before irradiation in the temperature range of 5-40 K.

Electrospinning of Polyvinylidene Fluoride and Polyetherimide From Mixed Solvents

NASA Technical Reports Server (NTRS)

Morgret, Leslie D.; Pawlowski, Kristin J.; Hinkley, Jeffrey A.

2005-01-01

Polyvinylidene fluoride and Ultem(TradeMark) polyetherimide were dissolved in 50/50 acetone/N,N dimethylformamide (DMF) and 80/20 tetrahydrofuran/DMF, respectively, and electrospun. Polymer solution concentrations and molecular weights were changed while other spinning parameters (voltage, distance, solution feed rate) were held constant. Fiber diameters in the resulting electrospun mats varied from 0.25 to 4.4 microns, increasing with polymer concentration and molecular weight; trends in diameter were compared with trends in viscosities and surface tensions of the spinning solutions.

Modeling thermo-optic effect in large mode area double cladding photonic crystal fibers

NASA Astrophysics Data System (ADS)

Coscelli, Enrico; Cucinotta, Annamaria

2014-02-01

The impact of thermally-induced refractive index changes on the single-mode (SM) properties of large mode area (LMA) photonic crystal fibers are thoroughly investigated by means of a full-vector modal solver with integrated thermal model. Three photonic crystal fiber designs are taken into account, namely the 19-cell core fiber, the large-pitch fiber (LPF) and the distributed modal filtering (DMF) fiber, to assess the effects of the interplay between thermal effects and the high-order mode (HOM) suppression mechanisms exploited in order to obtain effectively SM guiding. The results have shown significant differences in the way the SM regime is changed by the increase of heat load, providing useful hints for the design of LMA fibers for high power lasers.

Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

NASA Astrophysics Data System (ADS)

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei

2015-12-01

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H2ndc) or 4,4‧-(hydroxymethylene)dibenzoic acid (H2hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd2(2,6-ndc)2(bpp)(DMF)]·2DMF (1) and [Cd3(hmdb)3(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional 'Lucky Clover' shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process.

Protection of mice against mixed fission neutron-gamma (n: gamma = 1:1) irradiation by WR-2721, 16,16-dimethyl PGE2, and the combination of both agents

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

Steel, L.K.; Walden, T.L. Jr.; Hughes, H.N.

1988-09-01

The survival of mice after whole-body exposure to a modified fission neutron-gamma field (n: gamma = 1:1) was used to examine radiation protection by WR-2721, 16,16-dimethyl PGE2(DiPGE2), and the combination of both agents. Administration of WR-2721 (453 mg/kg) increased the LD50/30 from 5.24 to 7.17 Gy (DMF = 1.37), whereas pretreatment with DiPGE2 (1.6 mg/kg) increased the LD50/30 to 5.77 Gy (dose modification factor (DMF) = 1.10). The combination of 453 mg/kg WR-2721 and 0.4 mg/kg DiPGE2 resulted in an LD50/30 of 7.33 Gy, yielding a DMF of 1.39. However, no significant difference in protection was obtained with the combinationmore » of the two agents compared to that seen with WR-2721 alone.« less

Digital Microfluidics for Manipulation and Analysis of a Single Cell.

PubMed

He, Jie-Long; Chen, An-Te; Lee, Jyong-Huei; Fan, Shih-Kang

2015-09-15

The basic structural and functional unit of a living organism is a single cell. To understand the variability and to improve the biomedical requirement of a single cell, its analysis has become a key technique in biological and biomedical research. With a physical boundary of microchannels and microstructures, single cells are efficiently captured and analyzed, whereas electric forces sort and position single cells. Various microfluidic techniques have been exploited to manipulate single cells through hydrodynamic and electric forces. Digital microfluidics (DMF), the manipulation of individual droplets holding minute reagents and cells of interest by electric forces, has received more attention recently. Because of ease of fabrication, compactness and prospective automation, DMF has become a powerful approach for biological application. We review recent developments of various microfluidic chips for analysis of a single cell and for efficient genetic screening. In addition, perspectives to develop analysis of single cells based on DMF and emerging functionality with high throughput are discussed.

Digital Microfluidics for Manipulation and Analysis of a Single Cell

PubMed Central

He, Jie-Long; Chen, An-Te; Lee, Jyong-Huei; Fan, Shih-Kang

2015-01-01

The basic structural and functional unit of a living organism is a single cell. To understand the variability and to improve the biomedical requirement of a single cell, its analysis has become a key technique in biological and biomedical research. With a physical boundary of microchannels and microstructures, single cells are efficiently captured and analyzed, whereas electric forces sort and position single cells. Various microfluidic techniques have been exploited to manipulate single cells through hydrodynamic and electric forces. Digital microfluidics (DMF), the manipulation of individual droplets holding minute reagents and cells of interest by electric forces, has received more attention recently. Because of ease of fabrication, compactness and prospective automation, DMF has become a powerful approach for biological application. We review recent developments of various microfluidic chips for analysis of a single cell and for efficient genetic screening. In addition, perspectives to develop analysis of single cells based on DMF and emerging functionality with high throughput are discussed. PMID:26389890

Electronic spectra and DFT calculations of some pyrimido[1,2-a]benzimidazole derivatives

NASA Astrophysics Data System (ADS)

Elshakre, Mohamed E.; Moustafa, H.; Hassaneen, Huwaida. M. E.; Moussa, Abdelrahim. Z.

2015-06-01

Ground state properties of 2,4-diphenyl-1,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine, compound 1, and its derivatives are investigated experimentally and theoretically in Dioxane and DMF. The calculations show that all the studied compounds (1-7) are non-planar, resulting in a significant impact on the electronic and structural properties. The ground state properties of compounds 1-7 at B3LYP/6-311G (d, p) show that compound 5 has the lowest EHOMO, ELUMO, and ΔE indicating highest reactivity. Compound 7 is found to have the highest polarity. The observed UV spectra in Dioxane and DMF of compounds 1-4 show 2 bands, while compounds 5-7 show 4 bands in both solvents. Band maxima (λmax) and intensities of the spectra are found to have solvent dependence reflected as blue and red shifts. The theoretical spectra computed at TD-B3LYP/6-311G (d, p) in gas phase, Dioxane and DMF indicate a good agreement with the observed spectra.

A simple fabrication of CH3NH3PbI3 perovskite for solar cells using low-purity PbI2

NASA Astrophysics Data System (ADS)

Guo, Nanjie; Zhang, Taiyang; Li, Ge; Xu, Feng; Qian, Xufang; Zhao, Yixin

2017-01-01

The CH3NH3PbI3 (MAPbI3) perovskite was usually prepared by high-purity PbI2 with high cost. The low cost and low-purity PbI2 was seldom reported for fabrication of MAPbI3 because it cannot even dissolve well in widely adopted solvent of DMF. We developed an easy method to adapt low-purity PbI2 for fabrication of high quality MAPbI3 just by the simple addition of some hydrochloric acid into the mixture of low-purity PbI2, MAI and DMF. This straightforward method can not only help dissolve the low quality PbI2 by reacting with some impurities in DMF, but also lead to a successful fabrication of high-quality perovskite solar cells with up to 14.80% efficiency comparable to the high quality PbI2 precursors. Project supported by the National Natural Science Foundation of China (Nos. 51372151, 21303103) and Houyingdong Grant (No. 151046).

Digital microfluidic three-dimensional cell culture and chemical screening platform using alginate hydrogels

PubMed Central

2015-01-01

Electro wetting-on-dielectric (EWOD) digital microfluidics (DMF) can be used to develop improved chemical screening platforms using 3-dimensional (3D) cell culture. Alginate hydrogels are one common method by which a 3D cell culture environment is created. This paper presents a study of alginate gelation on EWOD DMF and investigates designs to obtain uniform alginate hydrogels that can be repeatedly addressed by any desired liquids. A design which allows for gels to be retained in place during liquid delivery and removal without using any physical barriers or hydrophilic patterning of substrates is presented. A proof of concept screening platform is demonstrated by examining the effects of different concentrations of a test chemical on 3D cells in alginate hydrogels. In addition, the temporal effects of the various chemical concentrations on different hydrogel posts are demonstrated, thereby establishing the benefits of an EWOD DMF 3D cell culture and chemical screening platform using alginate hydrogels. PMID:25945142

A simple solubility tests for the discrimination of acrylic and modacrylic fibers.

PubMed

Suga, Keisuke; Narita, Yuji; Suzuki, Shinichi

2014-05-01

In a crime scene investigation, single fibers play an important role as significant trace physical evidence. Acrylic fibers are frequently encountered in forensic analysis. Currently, acrylic and modacrylic are not discriminated clearly in Japan. Only results of FT-IR, some of acrylics were difficult to separate clearly to acrylic and modacrylic fibers. Solubility test is primitive but convenient useful method, and Japan Industrial Standards (JIS) recommends FT-IR and solubility test to distinguish acrylic and modacrylic fibers. But recommended JIS dissolving test using 100% N,N-dimethylformamide (DMF) as a solvent, some acrylics could not be discriminated. In this report, we used DMF and ethanol (90:10, v/v) solvent. The JIS method could not discriminate 6 acrylics in 60 acrylics; hence, DMF and ethanol (90:10, v/v) solvent discriminated 59 of the 60 fibers (43 acrylic and 16 modacrylic fibers) clearly, but only one modacrylic fiber incorrectly identified as acrylic. © 2014 American Academy of Forensic Sciences.

Tuning the Morphology and Activity of Electrospun Polystyrene/UiO-66-NH2 Metal-Organic Framework Composites to Enhance Chemical Warfare Agent Removal.

PubMed

Peterson, Gregory W; Lu, Annie X; Epps, Thomas H

2017-09-20

This work investigates the processing-structure-activity relationships that ultimately facilitate the enhanced performance of UiO-66-NH 2 metal-organic frameworks (MOFs) in electrospun polystyrene (PS) fibers for chemical warfare agent detoxification. Key electrospinning processing parameters including solvent type (dimethylformamide [DMF]) vs DMF/tetrahydrofuran [THF]), PS weight fraction in solution, and MOF weight fraction relative to PS were varied to optimize MOF incorporation into the fibers and ultimately improve composite performance. It was found that composites spun from pure DMF generally resulted in MOF crystal deposition on the surface of the fibers, while composites spun from DMF/THF typically led to MOF crystal deposition within the fibers. For cases in which the MOF was incorporated on the periphery of the fibers, the composites generally demonstrated better gas uptake (e.g., nitrogen, chlorine) because of enhanced access to the MOF pores. Additionally, increasing both the polymer and MOF weight percentages in the electrospun solutions resulted in larger diameter fibers, with polymer concentration having a more pronounced effect on fiber size; however, these larger fibers were generally less efficient at gas separations. Overall, exploring the electrospinning parameter space resulted in composites that outperformed previously reported materials for the detoxification of the chemical warfare agent, soman. The data and strategies herein thus provide guiding principles applicable to the design of future systems for protection and separations as well as a wide range of environmental remediation applications.

Thermodynamics of solvent interaction with the metal-organic framework MOF-5.

PubMed

Akimbekov, Zamirbek; Wu, Di; Brozek, Carl K; Dincă, Mircea; Navrotsky, Alexandra

2016-01-14

The inclusion of solvent in metal-organic framework (MOF) materials is a highly specific form of guest-host interaction. In this work, the energetics of solvent MOF-5 interactions has been investigated by solution calorimetry in 5 M sodium hydroxide (NaOH) at room temperature. Solution calorimetric measurement of enthalpy of formation (ΔH(f)) of Zn4O(C8H4O4)3·C3H7NO (MOF-5·DMF) and Zn4O(C8H4O4)3·0.60C5H11NO (MOF-5·0.60DEF) from the dense components zinc oxide (ZnO), 1,4-benzenedicarboxylic acid (H2BDC), N,N-dimethylformamide (DMF) and N,N-diethylformamide (DEF) gives values of 16.69 ± 1.21 and 45.90 ± 1.46 kJ (mol Zn4O)(-1), respectively. The enthalpies of interaction (ΔH(int)) for DMF and DEF with MOF-5 are -82.78 ± 4.84 kJ (mol DMF)(-1) and -89.28 ± 3.05 kJ (mol DEF)(-1), respectively. These exothermic interaction energies suggest that, at low guest loading, Lewis base solvents interact more strongly with electron accepting Zn4O clusters in the MOF than at high solvent loading. These data provide a quantitative thermodynamic basis to investigate transmetallation and solvent assisted linker exchange (SALE) methods and to synthesize new MOFs.

Incidence and mitigation of gastrointestinal events in patients with relapsing-remitting multiple sclerosis receiving delayed-release dimethyl fumarate: a German phase IV study (TOLERATE).

PubMed

Gold, Ralf; Schlegel, Eugen; Elias-Hamp, Birte; Albert, Christian; Schmidt, Stephan; Tackenberg, Björn; Xiao, James; Schaak, Tom; Salmen, Hans Christian

2018-01-01

Gastrointestinal (GI) events are common adverse events (AEs) associated with delayed-release dimethyl fumarate (DMF), an approved treatment for relapsing-remitting multiple sclerosis (RRMS). The objective of the TOLERATE study was to evaluate GI tolerability and GI mitigation via symptomatic therapies in patients initiating DMF in a real-world clinical setting in Germany. TOLERATE was a multicentre, open-label, single-arm study performed at 25 German sites. Endpoints were frequency, severity, duration (all primary) and mitigation of GI-related events (secondary). Patients were instructed to take DMF according to the prescribing information for up to 12 weeks and to document GI events and intake of GI-symptomatic therapy on numerical rating scales, using eDiaries. A total of 211 patients were included in the safety population (71% female; mean age 40 ± 11 years). Of these, 185 patients (87.7%) reported GI-related events, out of which nearly half received GI-symptomatic therapy (84/185; 45.4%). The most frequently reported GI events were upper abdominal pain, flatulence and nausea. GI-related events peaked during the first 3 weeks of therapy and rapidly decreased thereafter. The severity of GI events over 12 weeks according to the Modified Overall Gastrointestinal Symptom Scale were mild to moderate in the majority of patients reporting GI-related events and taking symptomatic GI medication (53.6%). Only 10% of all patients discontinued study treatment due to AEs in general, while 6.6% discontinued due to GI-related events. The severity of GI-related events decreased over time in patients who received symptomatic treatment with one or more medications (e.g. acid secretion blockers, antidiarrhoeals or antiemetics). Gastrointestinal events associated with delayed-release DMF were mainly mild to moderate in severity. Prevalence of GI events peaked during the first 3 weeks of therapy and rapidly faded thereafter. Although 44.9% of patients experiencing GI events used common GI symptomatic therapies, only 6.6% of patients discontinued DMF because of GI events, suggesting that GI events could be managed well with common symptomatic therapy.

Chemoprevention of azoxymethane-induced colon cancer by ascorbylpalmitate, carbenoxolone, dimethylfumarate and p-methoxyphenol in male F344 rats.

PubMed

Rao, C V; Rivenson, A; Kelloff, G J; Reddy, B S

1995-01-01

The chemopreventive effect of 40 and 80% maximum tolerated dose (MTD) levels of ascorbylpalmitate (AP), carbenoxolone (CBX), dimethylfumarate (DMF) and p-methoxyphenol (p-MP) administrated in the diet before and during initiation and postinitiation phases of azoxymethane (AOM)-induced colon carcinogenesis was studied in male F344 rats. The MTD levels of AP, CBX, DMF and p-MP were determined in male F344 rats and found to be 5000 1500, 1000 and 1000 ppm, respectively, in modified AIN-76A diet. Based on these MTD values, 40 and 80% MTD levels of each agent was tested for their efficacy in color carcinogenesis. At 5 weeks of age, groups of animals were fed the control (modified AIN-76A diet or diets containing 40 and 80% MTD levels of each AP, CBX, DMF and p-MP. At 7 weeks of age, all animals, except those in the vehicle (normal saline)-treated groups, were given two weekly s.c. injections of AOM at a dose rate of 15 mg/kg body weight/week. All groups were continued on their respective dietary regimen until the termination of the experiment 52 weeks after the carcinogen treatment. Colonic tumors were evaluated histopathologically. The results indicate that dietary administration of 40% MTD of AP significantly inhibited multiplicities (tumor/animal) of noninvasive and total (invasive plus noninvasive) adenocarcinoma of the colon (P < 0.05) and 80% MTD of AP significantly inhibited the incidence (% animals with tumors) and the multiplicities of invasive and total adenocarcinomas of the colon (P < 0.01). Dietary CBX at 40 and 80% MTD levels suppressed the incidence and multiplicities of invasive and total adenocarcinomas (P < 0.05 to 0.001) whereas 40 and 80% MTD of DMF and p-MP had significantly inhibited invasive adenocarcinoma incidence and multiplicity (P < 0.05 to 0.001). However, DMF and p-MP had no significant effect on noninvasive and total adenocarcinoma incidence and multiplicity (P > 0.05). These results suggest that AP and CBX possess potential chemopreventive properties against colon cancer.

Assessment of antiradiation drug effectiveness to fission neutron irradiation. Annual report September 1981-August 1982

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

Sigdestad, C.P.

1982-09-01

This report describes the assays of various compounds for their toxicity and anti-radiation efficacy following exposure to either Co-60 or fission neutron irradiation. The chemicals covered in this report are: WR 347, WR 1065, WR 2529, WR 2721, WR 3689, WR 44923, WR 109342, WR 151327 and WR 168643. The drugs and their respective dose modification factors (DMF) for fission neutron gastrointestinal lethality (LD50-6) following intraperitoneal administration are, in decreasing order of effectiveness: WR 44923 (1.77), WR 2529 (1.47), WR 1065 (1.42), WR 2721 (1.39), WR 16843 (1.23). Following per os (P. O.) administration of the drug, the DMF's formore » the LD50-6 are: WR 109342 (1.47), WR 3689 (1.36), and WR 168643 (1.31). For hematopoietic neutron radiation lethality (LD50-30) the DMF's are: following i.p. administration, WR 2529 (1.04); WR 151327 (1.34), WR 168643 (1.25), WR 44923 (1.22), WR 2721 (1.20), WR 1065 (1.04); following P. O. administration, WR 168643 (1.38), WR 109342 (1.21), WR 3689 (1.04). Using an intestinal microcolony assay system the following drugs provided the listed DMF's against neutron radiation after i.p. injection: WR 3689 (1.24), WR 2721 (1.15), WR 44923 (1.14), and WR 347 (1.05). The protective effects against neutron radiation using an endogenous spleen colony assay and i.p. administration were: WR 3689 (1.18), WR 2529 (1.15), WR 2721 (1.10), WR 44923 (1.02) and WR 347 (0.94).« less

Spectroscopy of N,N-dimethylformamide in the VUV and IR regions: Experimental and computational studies

NASA Astrophysics Data System (ADS)

Shastri, Aparna; Das, Asim Kumar; Krishnakumar, Sunanda; Singh, Param Jeet; Raja Sekhar, B. N.

2017-12-01

The electronic absorption spectrum of N,N-dimethylformamide (DMF) is studied in the 45 000-80 000 cm-1 (5.6-9.9 eV) region using synchrotron radiation. The vacuum ultraviolet (VUV) spectrum comprises mostly of Rydberg series of ns, np, and nd types converging to the first two ionization potentials (IPs). Quantum defect values obtained are consistent with excitation of an electron from the highest occupied molecular orbitals localized on nitrogen (4a″) and oxygen (16a'); in addition, the 3s Rydberg transition converging to the third IP (3a″) is observed at 8.95 eV. A reinvestigation of the infrared spectrum of DMF in the 500-4000 cm-1 region with the help of density functional theory (DFT) calculations establishes the planarity of the ground state and leads to revision of several vibrational assignments. Vertical excited state energies and their valence/Rydberg character are predicted using time dependent DFT calculations; excellent correlation is achieved between theoretical results and experimentally observed spectral features. Potential energy curves of the first few excited states give additional insights into the nature of the excited states and their role in photodissociation dynamics. The absorption spectrum of DMF in the region >63 400 cm-1 (7.85 eV) as well as a complete set of spectral assignments in the VUV region (45 000-80 000 cm-1) is reported for the first time. This work represents a comprehensive study of the absorption spectra of DMF in the VUV and infrared regions.

Gas-phase study of new organozinc reagents by IRMPD-spectroscopy, computational modelling and tandem-MS.

PubMed

Massah, Ahmad R; Dreiocker, Frank; Jackson, Richard F W; Pickup, Barry T; Oomens, Jos; Meijer, Anthony J H M; Schäfer, Mathias

2011-08-07

An extensive set of organozinc iodides, useful for Negishi-type cross-coupling reactions, are investigated as respective cations after formal loss of iodide in the gas phase. Firstly, two new alkylzinc compounds derived from Tyrosine (Tyr) and Tryptophan (Trp) are closely examined. Secondly, the influence of specific protecting groups on the subtle balance between intra- and intermolecular coordination of zinc in these reagents is probed through trifluoroacetyl (TFA)-derivatized alkylzinc compounds. Finally, the influence of the strongly coordinating bidentate ligand N,N,N',N'-tetramethylethylenediamine (TMEDA) on the structure of alkylzinc cations is further explored in order to better understand the stability of the respective complexes towards water. A combination of electrospray (ESI)-MS/MS, accurate ion mass measurements, infrared multiple-photon dissociation (IRMPD) spectroscopy and computational modelling allowed the full characterisation of all dimethylformamide (DMF)-solvated and TMEDA-coordinated alkylzinc cations in the gas phase. The calculations indicate that the zinc cation in gas-phase alkylzinc-DMF or TMEDA-complex ions preferentially adopts a tetrahedral coordination sphere with four ligands. Additionally, conformers with only three binding partners bound to zinc but with effectively combined hydrogen-bond interactions are also found. Collision induced dissociation (CID) patterns demonstrate that the zinc-DMF interaction in tetrahedral four-coordinate mono-DMF-zinc complex ions as well as the interaction between TMEDA and zinc in the corresponding complex ions is even stronger than typical covalent bonds. In most cases, all major features of the IRMPD spectra are consistent with only a single major isomer, allowing secured identification and assignment. This journal is © the Owner Societies 2011

Repurposing the NRF2 Activator Dimethyl Fumarate as Therapy Against Synucleinopathy in Parkinson's Disease.

PubMed

Lastres-Becker, Isabel; García-Yagüe, Angel J; Scannevin, Robert H; Casarejos, María J; Kügler, Sebastian; Rábano, Alberto; Cuadrado, Antonio

2016-07-10

This preclinical study was aimed at determining whether pharmacological targeting of transcription factor NRF2, a master controller of many homeostatic genes, might provide a disease-modifying therapy in the animal model of Parkinson's disease (PD) that best reproduces the main hallmark of this pathology, that is, α-synucleinopathy, and associated events, including nigral dopaminergic cell death, oxidative stress, and neuroinflammation. Pharmacological activation of NRF2 was achieved at the basal ganglia by repurposing dimethyl fumarate (DMF), a drug already in use for the treatment of multiple sclerosis. Daily oral gavage of DMF protected nigral dopaminergic neurons against α-SYN toxicity and decreased astrocytosis and microgliosis after 1, 3, and 8 weeks from stereotaxic delivery to the ventral midbrain of recombinant adeno-associated viral vector expressing human α-synuclein. This protective effect was not observed in Nrf2-knockout mice. In vitro studies indicated that this neuroprotective effect was correlated with altered regulation of autophagy markers SQTSM1/p62 and LC3 in MN9D, BV2, and IMA 2.1 and with a shift in microglial dynamics toward a less pro-inflammatory and a more wound-healing phenotype. In postmortem samples of PD patients, the cytoprotective proteins associated with NRF2 expression, NQO1 and p62, were partly sequestered in Lewy bodies, suggesting impaired neuroprotective capacity of the NRF2 signature. These experiments provide a compelling rationale for targeting NRF2 with DMF as a therapeutic strategy to reinforce endogenous brain defense mechanisms against PD-associated synucleinopathy. DMF is ready for clinical validation in PD. Antioxid. Redox Signal. 25, 61-77.

Effect of degree of sulfonation and casting solvent on sulfonated poly(ether ether ketone) membrane for vanadium redox flow battery

NASA Astrophysics Data System (ADS)

Xi, Jingyu; Li, Zhaohua; Yu, Lihong; Yin, Bibo; Wang, Lei; Liu, Le; Qiu, Xinping; Chen, Liquan

2015-07-01

The properties of sulfonated poly(ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) and casting solvent are investigated for vanadium redox flow battery (VRFB). The optimum DS of SPEEK membrane is firstly confirmed by various characterizations such as physicochemical properties, ion selectivity, and VRFB single-cell performance. Subsequently the optimum casting solvent is selected for the optimum DS SPEEK membrane within N,N‧-dimethylformamide (DMF), N,N‧-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO). The different performance of SPEEK membranes prepared with various casting solvents can be attributed to the different interaction between solvent and -SO3H group of SPEEK. In the VRFB single-cell test, the optimum SPEEK membrane with DS of 67% and casting solvent of DMF (S67-DMF membrane) exhibits higher VRFB efficiencies and better cycle-life performance at 80 mA cm-2. The investigation of various DS and casting solvent will be effective guidance on the selection and modification of SPEEK membrane towards VRFB application.

Instability behaviour of cosmic gravito-coupled correlative complex bi-fluidic admixture

NASA Astrophysics Data System (ADS)

Das, Papari; Karmakar, Pralay Kumar

2017-10-01

The gravitational instability of an unbounded infinitely extended composite gravitating cloud system composed of gravito-coupled neutral gaseous fluid (NGF) and dark matter fluid (DMF) is theoretically investigated in a classical framework. It is based on a spatially-flat geometry approximation (1D, sheet-like, boundless) at the backdrop that the radius of curvature of the gravito-confined bi-fluidic-boundary is much larger than all the hydro-characteristic scale lengths of interest. The relevant collective correlative dynamics, via the lowest-order mnemonic viscoelasticity, is mooted. We apply a standard formalism of normal mode analysis to yield a unique brand of generalized quadratic dispersion relation having variable multi-parametric coefficients dependent on the diversified equilibrium properties. It is parametrically seen that the DMF flow speed and the DMF viscoelasticity introduce stabilizing effects against the composite cloud collapse. The instability physiognomies, as specialized extreme corollaries, are in good accord with the previously reported predictions. The analysis may be widely useful to see the gravito-thermally coupled wave dynamics leading to the formation of large-scale hierarchical non-homologous structures in dark-matter-dominated dwarf galaxies.

Two 3D metal-organic frameworks as multi-functional materials to detect Fe3+ ions and nitroaromatic explosives and to encapsulate Ln3+ ions for white-light emission

NASA Astrophysics Data System (ADS)

Ma, Bing; Xu, Jianing; Qi, Hui; Sun, Jing; Chai, Juan; Jia, Jia; Jing, Shubo; Fan, Yong; Wang, Li

2018-02-01

Two metal-organic frameworks (MOFs), namely {[Zn3(L)2(4,4‧-bipy)(DMF)2]·2H2O}n(1) and {[Cd3(L)2(4,4‧-bipy)(H2O)2].2DMF}n(2) (4,4‧-bipy = 4,4‧-bipyridine, DMF = N,N-dimethylformamide), were solvothermally prepared based on a rigid tricarboxylic acid 3-(3,5-dicarboxylphenyl)-5-(3-carboxylphenyl)-1-H-1,2,4-triazole (H3L). X-ray crystallographic analysis reveals that 1 and 2 are isostructural and both emit blue light. Notably, 1 exhibits good luminescent sensing for nitro-containing compounds and Fe3+ ions. In addition, the emission colors of 1 can be tuned from yellow to white and to blue by encapsulating different mole ratios of Eu3+ and Tb3+ ions and changing the excitation wavelength. A white emission with the Commission International de l'Eclairage (CIE) coordinates of (0.331, 0.337), which fall within the white-light region, emerges upon excitation at 340 nm.

Planar structured perovskite solar cells by hybrid physical chemical vapor deposition with optimized perovskite film thickness

NASA Astrophysics Data System (ADS)

Wei, Xiangyang; Peng, Yanke; Jing, Gaoshan; Cui, Tianhong

2018-05-01

The thickness of perovskite absorber layer is a critical parameter to determine a planar structured perovskite solar cell’s performance. By modifying the spin coating speed and PbI2/N,N-dimethylformamide (DMF) solution concentration, the thickness of perovskite absorber layer was optimized to obtain high-performance solar cells. Using a PbI2/DMF solution of 1.3 mol/L, maximum power conversion efficiency (PCE) of a perovskite solar cell is 15.5% with a perovskite film of 413 nm at 5000 rpm, and PCE of 14.3% was also obtained for a solar cell with a perovskite film of 182 nm thick. It is derived that higher concentration of PbI2/DMF will result in better perovskite solar cells. Additionally, these perovskite solar cells are highly uniform. In 14 sets of solar cells, standard deviations of 11 sets of solar cells were less than 0.50% and the smallest standard deviation was 0.25%, which demonstrates the reliability and effectiveness of hybrid physical chemical vapor deposition (HPCVD) method.

Dichlorobenzene: an effective solvent for epoxy/graphene nanocomposites preparation

PubMed Central

Saharudin, Mohd Shahneel; Vo, Thuc; Inam, Fawad

2017-01-01

It is generally recognized that dimethylformamide (DMF) and ethanol are good media to uniformly disperse graphene, and therefore have been used widely in the preparation of epoxy/graphene nanocomposites. However, as a solvent to disperse graphene, dichlorobenzene (DCB) has not been fully realized by the polymer community. Owing to high values of the dispersion component (δd) of the Hildebrand solubility parameter, DCB is considered as a suitable solvent for homogeneous graphene dispersion. Therefore, epoxy/graphene nanocomposites have been prepared for the first time with DCB as a dispersant; DMF and ethanol have been chosen as the reference. The colloidal stability, mechanical properties, thermogravimetric analysis, dynamic mechanical analysis and scanning electron microscopic images of nanocomposites have been obtained. The results show that with the use of DCB, the tensile strength of graphene has been improved from 64.46 to 69.32 MPa, and its flexural strength has been increased from 97.17 to 104.77 MPa. DCB is found to be more effective than DMF and ethanol for making stable and homogeneous graphene dispersion and composites. PMID:29134080

Dichlorobenzene: an effective solvent for epoxy/graphene nanocomposites preparation.

PubMed

Wei, Jiacheng; Saharudin, Mohd Shahneel; Vo, Thuc; Inam, Fawad

2017-10-01

It is generally recognized that dimethylformamide (DMF) and ethanol are good media to uniformly disperse graphene, and therefore have been used widely in the preparation of epoxy/graphene nanocomposites. However, as a solvent to disperse graphene, dichlorobenzene (DCB) has not been fully realized by the polymer community. Owing to high values of the dispersion component ( δ d ) of the Hildebrand solubility parameter, DCB is considered as a suitable solvent for homogeneous graphene dispersion. Therefore, epoxy/graphene nanocomposites have been prepared for the first time with DCB as a dispersant; DMF and ethanol have been chosen as the reference. The colloidal stability, mechanical properties, thermogravimetric analysis, dynamic mechanical analysis and scanning electron microscopic images of nanocomposites have been obtained. The results show that with the use of DCB, the tensile strength of graphene has been improved from 64.46 to 69.32 MPa, and its flexural strength has been increased from 97.17 to 104.77 MPa. DCB is found to be more effective than DMF and ethanol for making stable and homogeneous graphene dispersion and composites.

Alkylating Derivatives of Vitamin D Hormone for Prostate Cancer

DTIC Science & Technology

2006-10-01

Acetic Anhydride / Pyridine/ 40C 1. UV / Toluene 2. EtOH - Reflux TBDMSCl / Imidazole /DMF BrCH2COOH / DCC / DMAP / CH2Cl2 1,25(OH)2D3-3-BE Figure 1...BE OH SO2 OTBDMS OH OTBDMS 1. Liq. SO2 / Reflux 2. TBDMSCl / Imidazole /DMF NaHCO3 / EtOH / Reflux NMO / SeO2 / CH2Cl2 / Reflux OH OTBDMSHO OTHP...containing 200 mg of 25-hydroxyvitamin D3 in a flask fitted with a trap that was cooled with dry ice-acetone (-780C). The yellow solution was refluxed

[Dental fluorosis and dental caries prevalence in Senegalese children living in a high-fluoride area and consuming a poor fluoridated drinking water].

PubMed

Faye, M; Diawara, C K; Ndiaye, K R; Yam, A A

2008-01-01

The role of fluoride in dental caries prevention when applied at optimal levels is well established. However, ingestion of excessive fluoride during tooth development can cause structural changes in tooth enamel named fluorosis. At Gandiaye a city situated in the Senegalese endemic fluorosis area, the main water supply provided by a unique drilling with highly fluoridated water has broken down in 1996. Since then, the drinking water comes from wells which have poor levels of fluorides. The aims of this study were to evaluate the prevalence and severity of dental fluorosis and tooth decays in children born and reared continuously at Gandiaye after the stoppage of the drills and who were drinking water well. Water samples were collected from two wells and analyzed using a spectrometer and a specific fluoride electrode. The prevalence and severity of dental fluorosis was evaluated according to Dean's method, and the caries experience was measured using the DMF teeth index in 150 children aged from 6 to 8 years. The fluoride levels in the water well were comprised between 0.03 ppm and 0.09 ppm according to the method used. The prevalence of dental fluorosis was 39.33% with the predominance of the very low to low fluorosis forms. The tooth decay prevalence was 48.66% and the mean DMF tooth was 0.98. A significant relationship was found between the dental fluorosis and the low caries levels. A low to moderate dental fluorosis associated with a significant decrease of caries prevalence was found in children living in a high-fluoride area and consuming poorly fluorided water.

Oral health in a group of patients with Rett syndrome in the regions of Valencia and Murcia (Spain): A case-control study

PubMed Central

Fuertes-González, María C.

2014-01-01

Objectives: Rett syndrome (RS) is a rare disease with oral manifestations that have not been described in detail or in a standardized manner in the literature. The present study describes the oral health of the population with RS in two Spanish regions, following the protocol of the World Health Organization for conducting common oral health surveys. Study Design: A prospective, observational case-control study was carried out, involving a group of patients with RS (n1=41) and a mean age of 13.37±3.19 years, and an age- and gender-matched control group without RS (n0=82). The data referred to oral health and habits were recorded by means of a questionnaire and oral examination was used to document caries indicators (prevalence of caries, df(t), df(s), DMF(T), DMF(S) and indices referred to dental loss, morbidity, restoration), the Community Periodontal Index (CPI), and the most characteristic oral manifestations. Results: The most frequent oral habit in the patients with RS was diurnal bruxism, followed by stereotyped tongue movements and oral breathing. The caries scores were lower in the RS population than in the control group, but patients with RS showed greater periodontal alterations and a greater prevalence of drooling, dental wear, high-arched palate and anterior open bite. Conclusions: The population with RS exhibits characteristic and early oral habits and alterations, and periodontal problems that are more notorious than caries disease, so that our efforts should focus on the diagnosis and early correction of the parafunctional habits, promoting restorative treatment, and providing instructions on correct oral hygiene. Key words:Rett syndrome, oral habits, bruxism, caries. PMID:25350594

Dental fluorosis and dental caries in permanent teeth: rural schoolchildren in high-fluoride areas in the Shaanxi province, China.

PubMed

Ruan, Jian-Ping; Yang, Zhuang-Qun; Wang, Zhi-Lun; Astrøm, Anne Nordrehaug; Bårdsen, Asgeir; Bjorvatn, Kjell

2005-10-01

To study the dental fluorosis and caries in the permanent teeth of 12 to 13-year-old children in fluorosis-endemic areas; to assess the relationship between fluorosis and the fluoride content of the drinking water and the relationship between caries and the fluoride content of the water; finally, to analyze the effect of fluoride intake and water stored in clay pots on dental fluorosis. 477 children were divided into 5 groups (A to E) according to the fluoride concentration of the waters, i.e. by 0.4, 1.0, 1.8, 3.5, and 5.6 mg F/l, respectively. Dental fluorosis was assessed by TF score and caries by the DMF-T index. A questionnaire was used to obtain information about water storage and other information relevant to children's fluoride intake. A positive relationship was found between the mean TF scores and the water fluoride concentration. In groups B and D, the TF score was higher in 13-year-olds than in 12-year-olds. Caries prevalence and mean DMF-T ranged from 2.6% and 0.03 (group E) to 22.1% and 0.38 (group A). Storage of water in clay pots seemed to increase the severity of fluorosis slightly, and to decrease the caries prevalence. Defluoridation of drinking water, or--alternatively--the provision of low-fluoride water sources, should be given high priority in the examined Shaanxi rural areas. Fluoride concentration of drinking water should be maximum 0.6 mg/l. Storage of water in the local clay pots may increase the severity of dental fluorosis.

X-ray diffraction and infrared spectroscopy of N,N-dimethylformamide and dimethyl sulfoxide solvatomorphs of betulonic acid.

PubMed

Boryczka, Stanisław; Jastrzebska, Maria; Bębenek, Ewa; Kusz, Joachim; Zubko, Maciej; Kadela, Monika; Michalik, Ewa

2012-12-01

X-ray diffraction and infrared spectroscopy measurements for the N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) solvatomorphs of betulonic acid (BA) were investigated. BA [3-oxolup-20(29)-en-28-oic acid, C(30)H(46)O(3)] exhibits a wide spectrum of biological activities and is considered to be a promising natural agent for the treatment of various cancer diseases. BA as a noncrystalline substance was obtained by oxidation of betulin. Crystal structures and the spectral data allowed analysis of hydrogen bonding (H-bonding), molecular conformation, and crystal packing differences in the solvatomorphs. Crystals of BA solvates were grown from the DMF-acetone (1:10, v/v) and DMSO-water (9:1, v/v) solutions. BA-DMF (1:1) solvate crystallizes in the monoclinic P2(1) space group, Z = 2. The unit cell parameters are as follows: cell lengths a = 13.2458(5) Å, b = 6.6501(2) Å, c = 17.9766(7) Å, and β = 110.513(4)°. BA-DMSO (1:1) solvate crystallizes in the orthorhombic P2(1)2(1)2(1) (Z = 4) space group with the following unit cell parameters: a = 6.6484(4) Å, b = 13.3279(8) Å, and c = 32.6821(19) Å. Conformational analysis of the six-membered rings, cyclopentane ring, and isopropenyl group showed differences in comparison with other betulin derivatives examined earlier. For both solvates, the intermolecular packing arrangement was governed mainly by H-bonds. The shortest H-bonds with D···A distances of 2.604 and 2.657 Å, and almost linear DH···A connection occurred between OH of carboxylic group of BA and oxygen atoms from O=C and O=S groups of DMF and DMSO, respectively. Copyright © 2012 Wiley Periodicals, Inc.

Numerical Simulations of the Digital Microfluidic Manipulation of Single Microparticles.

PubMed

Lan, Chuanjin; Pal, Souvik; Li, Zhen; Ma, Yanbao

2015-09-08

Single-cell analysis techniques have been developed as a valuable bioanalytical tool for elucidating cellular heterogeneity at genomic, proteomic, and cellular levels. Cell manipulation is an indispensable process for single-cell analysis. Digital microfluidics (DMF) is an important platform for conducting cell manipulation and single-cell analysis in a high-throughput fashion. However, the manipulation of single cells in DMF has not been quantitatively studied so far. In this article, we investigate the interaction of a single microparticle with a liquid droplet on a flat substrate using numerical simulations. The droplet is driven by capillary force generated from the wettability gradient of the substrate. Considering the Brownian motion of microparticles, we utilize many-body dissipative particle dynamics (MDPD), an off-lattice mesoscopic simulation technique, in this numerical study. The manipulation processes (including pickup, transport, and drop-off) of a single microparticle with a liquid droplet are simulated. Parametric studies are conducted to investigate the effects on the manipulation processes from the droplet size, wettability gradient, wetting properties of the microparticle, and particle-substrate friction coefficients. The numerical results show that the pickup, transport, and drop-off processes can be precisely controlled by these parameters. On the basis of the numerical results, a trap-free delivery of a hydrophobic microparticle to a destination on the substrate is demonstrated in the numerical simulations. The numerical results not only provide a fundamental understanding of interactions among the microparticle, the droplet, and the substrate but also demonstrate a new technique for the trap-free immobilization of single hydrophobic microparticles in the DMF design. Finally, our numerical method also provides a powerful design and optimization tool for the manipulation of microparticles in DMF systems.

Covalent functionalization of MoS2 nanosheets synthesized by liquid phase exfoliation to construct electrochemical sensors for Cd (II) detection.

PubMed

Gan, Xiaorong; Zhao, Huimin; Wong, Kwok-Yin; Lei, Dang Yuan; Zhang, Yaobin; Quan, Xie

2018-05-15

Surface functionalization is an effective strategy in the precise control of electronic surface states of two-dimensional materials for promoting their applications. In this study, based on the strong coordination interaction between the transition-metal centers and N atoms, the surface functionalization of few-layer MoS 2 nanosheets was successfully prepared by liquid phase exfoliation method in N, N-dimethylformamide (DMF), 1-methyl-2-pyrrolidinone, and formamide. The cytotoxicity of surface-functionalized MoS 2 nanosheets was for the first time evaluated by the methylthiazolyldiphenyl-tetrazoliumbromide assays. An electrochemical sensor was constructed based on glass carbon electrode (GCE) modified by MoS 2 nanosheets obtained in DMF, which exhibits relatively higher sensitivity to Cd 2+ detection and lower cytotoxicity against MCF-7 cells. The mechanisms of surface functionalization and selectively detecting Cd 2+ were investigated by density functional theory calculations together with various spectroscopic measurements. It was found that surface-functionalized MoS 2 nanosheets could be generated through Mo-N covalent bonds due to the orbital hybridization between the 5 s orbitals of Mo atoms and the 2p orbitals of N atoms of the solvent molecules. The high selectivity of the sensor is attributed to the coordination reaction between Cd 2+ and O donor atoms of DMF adsorbed on MoS 2 nanosheets. The robust anti-interference is ascribed to the strong binding energy of Cd 2+ and O atoms of DMF. Under the optimum conditions, the electrochemical sensor exhibits highly sensitive and selective assaying of Cd 2+ with a measured detection limit of 0.2 nM and a linear range from 2 nM to 20 μM. Copyright © 2018 Elsevier B.V. All rights reserved.

Air filtration media from electrospun waste high-impact polystyrene fiber membrane

NASA Astrophysics Data System (ADS)

Zulfi, Akmal; Miftahul Munir, Muhammad; Hapidin, Dian Ahmad; Rajak, Abdul; Edikresnha, Dhewa; Iskandar, Ferry; Khairurrijal, Khairurrijal

2018-03-01

Nanofiber membranes were synthesized from waste high-impact polystyrene (HIPS) using electrospinning method and then applied as air filtration media. The waste HIPS precursor solution with the concentration of 20 wt.% was prepared by dissolving waste HIPS into the mixture of d-limonene and DMF solvents. Beaded or fine nanofibers could be achieved by adjusting the ratio of solvents mixture (d-limonene and DMF). Using the ratios of solvents (d-limonene: DMF) of 3:1, 1:1, and 1:3, it was obtained beaded HIPS nanofibers with the average diameter of 272 nm, beaded HIPS nanofibers with the average diameter of 937, and fine HIPS nanofibers with the average diameter of 621 nm, respectively. From the FTIR spectral analysis, it was found that the FTIR peaks of the HIPS nanofiber membranes are the same as those of the cleaned waste HIPS and there are no FTIR peaks of DMF and d-limonene solvents. These findings implied that the electrospinning process allows the recycling of waste HIPS into HIPS nanofibers without any trapped solvent phases or apparent degradation of the original material. From the contact angle measurement, it was confirmed that the HIPS nanofiber membranes are hydrophobic and the presence of the beads in the HIPS nanofiber membranes varies their contact angles. From the air-filtration test, it was shown that the fiber morphology (beaded or fine nanofibers) considerably affects the filtration performance of the membranes. The presence of beads increased the distance between the fibers so that the pressure drop decreased. Moreover, the basis weight of the membrane greatly affected the filtration efficiency. The HIPS nanofiber membrane with the basis weight of 12.22 g m‑2 had the efficiency greater than 99.999%, which was equivalent to that of the HEPA filter.

Child, neglect and oral health

PubMed Central

2013-01-01

Background Despite advancements in oral health policies, dental caries still a problem. The lack of parents/caregiver’s care regarding child’s oral health, which characterizes neglect, may lead to a high prevalence of caries. Therefore, the objective of this study was to analyze the relation between dental caries and neglect in five year-old children. Methods Quantitative study performed in two different moments. First, the children underwent oral examinations and physical inspection. Then, a semi-structured interview was performed with parents of children with high and low caries rate. Results In all, 149 physical inspections and oral exams were performed. The number of decayed, missing and filled teeth – dmf-t was 2.75 (SD 2.83); 16 children had extremely high values (dmf-t ≥7), 85 intermediate values (1 ≤ dmf-t ≥ 6) and 48 extremely low (dmf-t = 0). Nearly all caregivers were female (96.7%; n = 29), mostly mothers (93.3%; n = 28). Associations were found between caries experience and reason of the last consultation (p = 0.011), decayed teeth and child’s oral health perception (p = 0.001). There was a trend towards a significant association between general health and decayed teeth (p = 0.079), general hygiene and caries experience (p = 0.083), and caries experience and number of times the child brushes the teeth (p = 0.086). Conclusion There’s a relation between caries experience and children’s oral health perception by caregivers, as well as between caries experience and children’s access to dental care. There is a trend towards association between caries experience and risk factors suggestive of neglect. PMID:24238222

A magnesium-carboxylate framework showing luminescent sensing for CS{sub 2} and nitroaromatic compounds

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

Wu, Zhao-Feng; Tan, Bin; University of Chinese Academy of Sciences, Beijing 100049

2015-03-15

A magnesium metal-organic framework compound, namely [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid, DMF=N,N′-dimethylformamide), has been synthesized in solvothermal conditions and structurally characterized. It features a three-dimensionally anionic framework with aligned channels parallel to the b-axis. Luminescent studies indicated that it showed significant luminescence quenching for carbon disulfide (CS{sub 2}) and nitrobenzene after being activated, at a content of only 3.0 and 0.1 vol% in DMF, respectively. In addition, the activated sample showed sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L. - Graphical abstract: Presentedmore » is a microporous 3D Mg-MOF, namely, [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid) showing significant luminescence quenching for carbon disulfide and nitrobenzene. - Highlights: • A microporous 3D metal-organic framework based on Mg. • The compound shows significant luminescence quenching for CS{sub 2} and nitrobenzene after activated. • The compound shows sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L.« less

Investigation of influence of conductivity on the polyaniline fiber mats, produced via electrospinning

NASA Astrophysics Data System (ADS)

Varnaitė-Žuravliova, Sandra; Savest, Natalja; Abraitienė, Aušra; Baltušnikaitė-Guzaitienė, Julija; Krumme, Andres

2018-05-01

Intrinsically conductive polymers are one very attractive material, because of their good electrical, electrochemical and optical properties, and a wide range of applications. The spinnability of Polyaniline (PANI) solutions is generally insufficient for it to be electrospun directly into fibers, but addition of another polymer to the organic solutions or usage of dopant and solvent may improve it. The aim of the research was: to produce nanofibers of the smallest diameter as possible by using conventional electrospinning setup; to investigate the influence of viscosity and electrical conductivity to the spinnability of PANI solutions; to control the electrical conductivity of prepared solutions and electrospun nanofibers by changing concentrations of chemicals used. The results of investigations made with prepared solutions shave showed, that the viscosity increases and the electrical conductivity is tending to decrease with increase of Polyethylenoxide (PEO) concentration in the spinning solution. In order to achieve greater conductivity, the Dimethylformamide (DMF) was added as a dopant. Though the conductivity of solutions was reached high enough, but the loss in viscosity resulted in depriation of greater spinnability of PANI nanofibers. Also it was noticed, that despite the fact that the electrical conductivity of all solutions was different, the electrical conductivity of fiber mats can be divided in two groups: fiber mats without DMF and fiber mats with DMF. The morphological analysis of produced fiber mats have showed, that higher PEO concentration resulted in thicker PANI nanofibers—the diameter varied from 333 nm till 4434 nm. The usage of DMF gave an opportunity to receive almost twice thinner conductive PANI nanofibers with narrower distribution in diameter. Slower flow rate of the electrospinning process resulted in thinner nanofibers as well.

Prevalence of dental caries in overweight school going children of 12-15 years in and around Jaipur city, Rajasthan, India

PubMed

Choudhary, Rahul; Sharma, Rajesh; Bhat, Manohar; Satish V; Khairwa, Abhishek; Solanki, Jitender

2017-01-01

Dental caries and obesity are both multifactorial disease with a complex etiology and both are associated with dietary habits. Prevalence of dental caries and an association between body mass index (BMI) and dental caries among school children The present was done on 1500 school going children to assess the prevalence of dental caries in 12-15 year old overweight children. Weight and height were measured in light clothing and without shoes using an electronic weighing scale. Subjects’ heights were measured using a stadiometre. Subjects were examined on an upright chair in adequate natural daylight and dental caries was measured by using DMF index. Chi-square test was used to analyze and compare qualitative data whereas unpaired ‘t’ test was used to analyze and compare quantative data Amongst 1500 children, 156 were found to be overweight, 443 were normal weight. When mean BMI between overweight and normal weight were compared a highly significant difference was observed. When DMFT of overweight and normal weight were compared no significant difference was observed Dental caries was observed more in females as compared to males and no significant difference was observed between dental caries and weight gain

The oral health status of dentate patients with chronic renal failure undergoing dialysis therapy.

PubMed

Bots, C P; Poorterman, J H G; Brand, H S; Kalsbeek, H; van Amerongen, B M; Veerman, E C I; Nieuw Amerongen, A V

2006-03-01

The aim of this study was to compare the oral health status of chronic renal failure (CRF) patients on renal replacement therapy with a matched reference population. Cross-sectional study. Forty-two dentate CRF patients--aged 25-52 years old--were matched with a reference group of 808 dentate subjects. The oral health was assessed using decayed missing filled (DMF) indices, simplified oral hygiene index and periodontal status. An oral health questionnaire was used to assess self-reported dental problems. Student t-tests and chi-square tests were performed to compare the CRF patients with the controls. All index-scores in the CRF patients were comparable with the controls except for number of teeth covered with calculus that was significantly higher (P < 0.05) in CRF patients (4.1 +/- 2.6) than in controls (3.0 +/- 2.9). The self-reported oral health questionnaire revealed a trend for increased temporomandibular complaints in CRF patients (16.7%vs 5.7% in controls; P = 0.06) as well as bad taste (31.0%vs 6.8% in controls, P = 0.08). For most dental aspects, the oral health of CRF patients is comparable with controls.

User’s Manual for Strategic Satellite System Terminal Segment Life Cycle Cost Model. Volume 1

DTIC Science & Technology

1981-03-01

the depot pipeline, given by: NFD(I) = EFAIL (I,NS)*TNB(NS) NS *1 [LRU(I) + RTS(NHI(1))]*NRTS(I)*DRCT(LO(NS)) + NRTS(NHI(i))*(l - COND(I))*DADI where... EFAIL (I,NS)*TNB(NS)* [(LRU(I) + RTS(NHI(I)))*NRTS(I) NS + NRTS(NHI(I))*(l-COND(I))] *DMH(I)*DMF where DMH(I) = averaRP marnours to perform depot...XJC - RSCA(I) + 12*PIUP* EFAIL (I,NS)*TNB(NS)* NS {(LRUCI)+RTS(NHI(I)))* (CR(I)*BIIH(I)*BMF*BLR + CN(I)*(DMH(I)*DMF*DLR + 2*CPPD(LOCNS))*WT(I)) + CC

Transient absorption spectroscopy of a monofullerene C60-bis-(pyropheophorbide a) molecular system in polar and nonpolar environments

NASA Astrophysics Data System (ADS)

Al Omari, S.; Ermilov, E. A.; Helmreich, M.; Jux, N.; Hirsch, A.; Röder, B.

2004-09-01

The population dynamics of the excited and ground states of the monofullerene-bis (pyropheophorbide a) complex (FP1) were studied in polar (DMF) and nonpolar (toluene) solvents using picosecond transient absorption techniques. A strong quenching of the fluorescence signal of FP1 was observed in both solvents, in comparison to the fluorescence of bis (pyropheophorbide a) (P2). This quenching is due to an intramolecular photoinduced electron transfer from the pyropheophorbide a (pyroPheo) moiety to the fullerene C60 monoadduct. In DMF the charge-separated (CS) state of FP1 has a lifetime of 0.32 ns and undergoes a direct transition to the ground state, resulting in a very low value of photosensitised singlet oxygen generation. In toluene, energy transfer from the first excited triplet state of pyroPheo, which has been populated via relaxation of the CS state, generates a considerable amount of singlet oxygen. The lifetime of the CS state in the nonpolar solvent was estimated to be 0.29 ns. It was also shown that in both DMF and toluene the first excited singlet state as well as the triplet state of the fullerene moiety in FP1 are not occupied.

C-PCM based calculation of energy profiles for proton transfer in phosphorus-containing acid- N, N-dimethylformamide complexes

NASA Astrophysics Data System (ADS)

Fedorova, I. V.; Khatuntseva, E. A.; Krest'yaninov, M. A.; Safonova, L. P.

2016-02-01

Proton transfer along the hydrogen bond in complexes of DMF with H3PO4, H3PO3, CH3H2PO3, and their dimers has been investigated by the B3LYP/6-31++G** method in combination with the C-PCM model. When the Oacid···ODMF distance ( R) in the scanning procedure is not fixed, the energy profile in all cases has a single well. When this distance is fixed, there can be a proton transfer in all of the complexes in the gas phase at R > 2.6 Å; if solvation is taken into account, proton transfer can take place at R > 2.4 Å ( R > 2.5 Å for DMF complexes with CH3H2PO3 and its dimer). The height of the energy barrier to proton transfer increases with increasing R. Proton transfer is energetically most favorable in the DMF-phosphoric acid complexes. The structural and energetic characteristics of the hydrogen-bonded complexes calculated on the basis of the solvation model are compared with the same parameters for the complexes in the gas phase.

Synthesis of porous Cu-BTC with ultrasonic treatment: Effects of ultrasonic power and solvent condition.

PubMed

Israr, Farrukh; Kim, Duk Kyung; Kim, Yeongmin; Oh, Seung Jin; Ng, Kim Choon; Chun, Wongee

2016-03-01

Cu-BTC (BTC=1,3,5-benzenetricarboxylate) metal organic framework (MOF) was synthesized using different solvent conditions with ultrasonic treatment. Solvent mixtures of water/N,N-dimethylformamide (DMF), water/ethanol were used for the reactions with or without a variety of bases under 20 kHz ultrasonically treated conditions. Prepared crystals were purified through 30 min of sonication to remove unreacted chemicals. Treatment time and ultrasonic power effects were compared to get optimum synthetic condition. The characterization of MOF powders was performed by scanning electron microscopy, X-ray powder diffraction, infrared-spectroscopy, thermo-gravimetric analysis and specific surface determination using the BET method. Isolated crystal yields varied with different solvent and applied ultrasonic power conditions. A high isolated crystal yield of 86% was obtained from water/ethanol/DMF solvent system after 120 min of ultrasonic treatment at 40% power of 750 W. Different solvent conditions led to the formation of Cu-BTC with different surface area, and an extremely high surface area of 1430 m(2)/g was obtained from the crystals taken with the solvent condition of water:DMF=70:30. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct fabrication of hybrid nanofibres composed of SiO2-PMMA nanospheres via electrospinning.

PubMed

Zhang, Ran; Shang, Tinghua; Yang, Guang; Jia, Xiaolong; Cai, Qing; Yang, Xiaoping

2016-08-01

The direct fabrication of hybrid nanofibres composed of poly(methyl methacrylate)-grafted SiO2 (SiO2-PMMA) nanospheres via electrospinning was investigated in detail. SiO2-PMMA nanospheres were successfully prepared, with the SiO2 nanospheres synthesized via the Stober method, followed by in situ surface-initiated atom transfer radical polymerization of methyl methacrylate (MMA). Electrospinning was carried out with N,N-dimethylformamide (DMF) as the solvent to disperse SiO2-PMMA nanospheres. The size of the SiO2 core, the molecular weight of the PMMA shell and the concentration of the SiO2-PMMA/DMF solution all had substantial effects on the morphology and structure of electrospun nanofibres composed of SiO2-PMMA nanospheres. When these determining factors were well-tailored, it was found that one-dimensional necklace-like nanofibres were obtained, with SiO2-PMMA nanospheres aligned one by one along the fibre. The successful fabrication of nanofibres by directly electrospinning the SiO2-PMMA/DMF solution verified that polymer-grafted particles possess polymer-like characteristics, which endowed them with the ability to be processed into desirable shapes and structures. Copyright © 2016 Elsevier B.V. All rights reserved.

An intramolecular antiferromagnetically coupled pentanuclear Mn(II) cluster containing acetate and tetracarboxylate linkers: Synthesis, structure and magnetism

NASA Astrophysics Data System (ADS)

Wu, Jian; Liu, Wei-Cong; Wu, Xi-Ren; Liu, Jian-Qiang; Sakiyama, Hiroshi; Yadav, Reena; Kumar, Abhinav

2016-06-01

A new Mn(II) complex {[Mn5(CH3COO)2(L)2(DMF)8](DMF)}n (1), (H4L = 3,5-bis(3‧,5‧-dicarboxylphenyl)-1H-1,2,3-triazole), has been synthesized and structurally characterized. The complex 1 have pentanuclear Mn(II) core, where the two sides of metal centers (Mn2 and Mn3) have trigonal bipyramidal arrangement and the middle metal center (Mn1) have octahedral environment utilizing two O atoms from adjacent bridging bidentate carboxylate groups and four O atoms from four coordinated DMF molecules. The planar arrangement of pentanuclear Mn(II) atoms are linked by L linkage to generate two dimensional sheet. The magnetic property of the compound indicates χMT value for the five Mn(II) unit to be 21.3 cm3 K mol-1 at 300 K, which is close to the spin-only value (21.9 cm3 K mol-1) for the pentamer having S = 5/2. Also, the Hirshfeld surface analyses have been performed which indicated the absence of weak Mn···Mn interaction thereby corroborating the results of observed magnetic properties.

Asymmetric MF-DCCA method based on risk conduction and its application in the Chinese and foreign stock markets

NASA Astrophysics Data System (ADS)

Cao, Guangxi; Han, Yan; Li, Qingchen; Xu, Wei

2017-02-01

The acceleration of economic globalization gradually shows the linkage of the stock markets in various counties and produces a risk conduction effect. An asymmetric MF-DCCA method is conducted based on the different directions of risk conduction (DMF-ADCCA) and by using the traditional MF-DCCA. To ensure that the empirical results are more objective and robust, this study selects the stock index data of China, the US, Germany, India, and Brazil from January 2011 to September 2014 using the asymmetric MF-DCCA method based on different risk conduction effects and nonlinear Granger causality tests to study the asymmetric cross-correlation between domestic and foreign stock markets. Empirical results indicate the existence of a bidirectional conduction effect between domestic and foreign stock markets, and the greater influence degree from foreign countries to domestic market compared with that from the domestic market to foreign countries.

A microbiological assessment of the oral hygiene of 24-72-month-old kindergarten children and disinfection of their toothbrushes.

PubMed

Celepkolu, Tahsin; Toptancı, Ismet Rezani; Bucaktepe, Pakize Gamze Erten; Sen, Velat; Dogan, Mehmet Sinan; Kars, Veysel; Aslanhan, Hamza; Aslan, Ilknur; Dal, Tuba; Yıldız, Ismail; Palancı, Yılmaz

2014-08-02

The objective of this study is to assess the index of decayed, missing and filled teeth (DMF-T), habit of brushing teeth, and the microbiological agents accumulating on the children's toothbrushes for 4 weeks and response of these agents to disinfection via a chlorhexidine solution, then compare those results with the education and income levels of the children's parents. Included in the study were 187 children (96 in the control group and 91 in the experiment group - chlorhexidine) chosen randomly from 600 kindergarten children whose ages ranged from 24 months to 72 months. The children selected had not taken any antibiotics, antimicotics for three months and dental treatments during this trial. The distribution of these children to the groups was also done randomly. After performing a survey for the education, occupation, and income status of the parents, the children were examined and the number of decayed teeth was recorded. The children were given toothbrushes, toothpaste (with fluroide), and the solutions (including distilled water and chlorhexidine) for four weeks under the condition that toothbrushes were returned at the end of each week. The 14 different microbiological agents observed as a result of the assessment of the samples taken in the first week were also included in the assessments of the samples taken over the four-week period. The decrease in the DMF-T index was found to be meaningful according to the differences in education, income, and occupation status of the parents. Of all the samples taken from the toothbrushes, the bacteria with the greatest rate of reproduction included Streptococcus mutans, Escherichia Coli, Pseudomonas aeuroginosa, Enterococcus spp, Staphylococcus epidermidis and Candida albicans. Except for Candida albicans, the other microorganisms taken as samples from the toothbrushes reproduced less overall. In the group using the solution with chlorhexidine, a meaningful decrease in bacterial reproduction was discovered compared to the control group. The findings of this study show that the education, occupation, and socioeconomic situations of the parents should be considered when discussing children's oral and dental health. Moreover, the study shows that disinfection of toothbrushes in order to prevent reinfection and contamination oral flora with the bacteria again is important in terms of preventive medicine and family-children health.

Transient thermal effect, nonlinear refraction and nonlinear absorption properties of graphene oxide sheets in dispersion.

PubMed

Zhang, Xiao-Liang; Liu, Zhi-Bo; Li, Xiao-Chun; Ma, Qiang; Chen, Xu-Dong; Tian, Jian-Guo; Xu, Yan-Fei; Chen, Yong-Sheng

2013-03-25

The nonlinear refraction (NLR) properties of graphene oxide (GO) in N, N-Dimethylformamide (DMF) was studied in nanosecond, picosecond and femtosecond time regimes by Z-scan technique. Results show that the dispersion of GO in DMF exhibits negative NLR properties in nanosecond time regime, which is mainly attributed to transient thermal effect in the dispersion. The dispersion also exhibits negative NLR in picosecond and femtosecond time regimes, which are arising from sp(2)- hybridized carbon domains and sp(3)- hybridized matrix in GO sheets. To illustrate the relations between NLR and nonlinear absorption (NLA), NLA properties of the dispersion were also studied in nanosecond, picosecond and femtosecond time regimes.

A new metal-organic framework for separation of C2H2/CH4 and CO2/CH4 at room temperature

NASA Astrophysics Data System (ADS)

Duan, Xing; Zhou, You; Lv, Ran; Yu, Ben; Chen, Haodong; Ji, Zhenguo; Cui, Yuanjing; Yang, Yu; Qian, Guodong

2018-04-01

A 3D microporous metal-organic framework with open Cu2+ sites and suitable pore space, [Cu2(L)(H2O)2]·(H2O)4(DMF)8 (ZJU-15, H4L = 5,5‧-(9H-carbazole-2,7-diyl)diisophthalic acid; DMF = N,N-dimethylformamide; ZJU = Zhejiang University), has been constructed and characterized. The activated ZJU-15a has three different types of cages and exhibits BET surface area of 1660 m2 g-1, and can separate gas mixture of C2H2/CH4 and CO2/CH4 at room temperature.

Amide-induced phase separation of hexafluoroisopropanol-water mixtures depending on the hydrophobicity of amides.

PubMed

Takamuku, Toshiyuki; Wada, Hiroshi; Kawatoko, Chiemi; Shimomura, Takuya; Kanzaki, Ryo; Takeuchi, Munetaka

2012-06-21

Amide-induced phase separation of hexafluoro-2-propanol (HFIP)-water mixtures has been investigated to elucidate solvation properties of the mixtures by means of small-angle neutron scattering (SANS), (1)H and (13)C NMR, and molecular dynamics (MD) simulation. The amides included N-methylformamide (NMF), N-methylacetamide (NMA), and N-methylpropionamide (NMP). The phase diagrams of amide-HFIP-water ternary systems at 298 K showed that phase separation occurs in a closed-loop area of compositions as well as an N,N-dimethylformamide (DMF) system previously reported. The phase separation area becomes wider as the hydrophobicity of amides increases in the order of NMF < NMA < DMF < NMP. Thus, the evolution of HFIP clusters around amides due to the hydrophobic interaction gives rise to phase separation of the mixtures. In contrast, the disruption of HFIP clusters causes the recovery of the homogeneity of the ternary systems. The present results showed that HFIP clusters are evolved with increasing amide content to the lower phase separation concentration in the same mechanism among the four amide systems. However, the disruption of HFIP clusters in the NMP and DMF systems with further increasing amide content to the upper phase separation concentration occurs in a different way from those in the NMF and NMA systems.

Multiple-access relaying with network coding: iterative network/channel decoding with imperfect CSI

NASA Astrophysics Data System (ADS)

Vu, Xuan-Thang; Renzo, Marco Di; Duhamel, Pierre

2013-12-01

In this paper, we study the performance of the four-node multiple-access relay channel with binary Network Coding (NC) in various Rayleigh fading scenarios. In particular, two relay protocols, decode-and-forward (DF) and demodulate-and-forward (DMF) are considered. In the first case, channel decoding is performed at the relay before NC and forwarding. In the second case, only demodulation is performed at the relay. The contributions of the paper are as follows: (1) two joint network/channel decoding (JNCD) algorithms, which take into account possible decoding error at the relay, are developed in both DF and DMF relay protocols; (2) both perfect channel state information (CSI) and imperfect CSI at receivers are studied. In addition, we propose a practical method to forward the relays error characterization to the destination (quantization of the BER). This results in a fully practical scheme. (3) We show by simulation that the number of pilot symbols only affects the coding gain but not the diversity order, and that quantization accuracy affects both coding gain and diversity order. Moreover, when compared with the recent results using DMF protocol, our proposed DF protocol algorithm shows an improvement of 4 dB in fully interleaved Rayleigh fading channels and 0.7 dB in block Rayleigh fading channels.

Oral Multiple Sclerosis Drugs Inhibit the In vitro Growth of Epsilon Toxin Producing Gut Bacterium, Clostridium perfringens.

PubMed

Rumah, Kareem R; Vartanian, Timothy K; Fischetti, Vincent A

2017-01-01

There are currently three oral medications approved for the treatment of multiple sclerosis (MS). Two of these medications, Fingolimod, and Teriflunomide, are considered to be anti-inflammatory agents, while dimethyl fumarate (DMF) is thought to trigger a robust antioxidant response, protecting vulnerable cells during an MS attack. We previously proposed that epsilon toxin from the gut bacterium, Clostridium perfringens , may initiate newly forming MS lesions due to its tropism for blood-brain barrier (BBB) vasculature and central nervous system myelin. Because gut microbiota will be exposed to these oral therapies prior to systemic absorption, we sought to determine if these compounds affect C. perfringens growth in vitro . Here we show that Fingolimod, Teriflunomide, and DMF indeed inhibit C. perfringens growth. Furthermore, several compounds similar to DMF in chemical structure, namely α, β unsaturated carbonyls, also known as Michael acceptors, inhibit C. perfringens . Sphingosine, a Fingolimod homolog with known antibacterial properties, proved to be a potent C. perfringens inhibitor with a Minimal Inhibitory Concentration similar to that of Fingolimod. These findings suggest that currently approved oral MS therapies and structurally related compounds possess antibacterial properties that may alter the gut microbiota. Moreover, inhibition of C. perfringens growth and resulting blockade of epsilon toxin production may contribute to the clinical efficacy of these disease-modifying drugs.

Quality control of next-generation sequencing library through an integrative digital microfluidic platform.

PubMed

Thaitrong, Numrin; Kim, Hanyoup; Renzi, Ronald F; Bartsch, Michael S; Meagher, Robert J; Patel, Kamlesh D

2012-12-01

We have developed an automated quality control (QC) platform for next-generation sequencing (NGS) library characterization by integrating a droplet-based digital microfluidic (DMF) system with a capillary-based reagent delivery unit and a quantitative CE module. Using an in-plane capillary-DMF interface, a prepared sample droplet was actuated into position between the ground electrode and the inlet of the separation capillary to complete the circuit for an electrokinetic injection. Using a DNA ladder as an internal standard, the CE module with a compact LIF detector was capable of detecting dsDNA in the range of 5-100 pg/μL, suitable for the amount of DNA required by the Illumina Genome Analyzer sequencing platform. This DMF-CE platform consumes tenfold less sample volume than the current Agilent BioAnalyzer QC technique, preserving precious sample while providing necessary sensitivity and accuracy for optimal sequencing performance. The ability of this microfluidic system to validate NGS library preparation was demonstrated by examining the effects of limited-cycle PCR amplification on the size distribution and the yield of Illumina-compatible libraries, demonstrating that as few as ten cycles of PCR bias the size distribution of the library toward undesirable larger fragments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advantages of using an abbreviated dossier for drug master file applications in Taiwan.

PubMed

Sun, I-Chen

2016-10-01

In Taiwan, the quality of active pharmaceutical ingredients is recorded in a drug master file (DMF), the applications for which can be submitted in two dossier types, either full (complete technical information) or abbreviated (partially complete technical information with an approved document issued by developed countries). However, the advantages of the abbreviated approach remain unknown. This study compared full and abbreviated dossier profiles and reviewed their outcomes in acceptance rates and deficiencies leading to rejection. Data were collected from new submissions of both dossier types that were completed in 2014 by the Center for Drug Evaluation, Taiwan. The results revealed that the abbreviated applications took shorter review time and had a higher acceptance rate. Among the eligible types of document for abbreviated applications, Certification of Suitability to the Monographs of the European Pharmacopeia (CEP) was the most frequently used. For categorical deficiencies, both dossier types presented the deficiencies in similar sections leading to rejection, namely Manufacture (3.2.S.2), Control of drug substance (3.2.S.4), and Stability (3.2.S.7). In summary, CEP serves a favorable document for the abbreviated DMF application in which it shortens the review time, increases the acceptance rate, and its deficiencies are similar to those of the full DMF application. Copyright © 2016 Elsevier Inc. All rights reserved.

Preparation, characterization and in vitro anticoagulant activity of corn stover xylan sulfates.

PubMed

Cheng, He-Li; Liu, Hao; Feng, Qing-Hua; Xie, Yi-Min; Zhan, Huai-Yu

2017-02-01

A new anticoagulant agent was prepared by introducing sulfate groups into corn stover xylan through homogeneous reactions. Three organic solvents, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and formamide (FA), were adopted as reaction media, with the assistance of LiCl. Structural characterization by FT-IR and 13 CNMR showed that xylan sulfate (XS) could be successfully synthesized with SO 3 ∙Pyridine (SO 3 ∙Py) complexes sulfation reagent in the three media. The effect of sulfation temperature, sulfation time, media type and molar ratio of -SO 3 /-OH on the degree of substitution (DS) and degree of the polymerization (DP) were studied. DMF/LiCl were more effective than DMSO/LiCl and FA/LiCl in preparation of xylan sulfate with high DS. The optimal conditions for sulfation were obtained when SO 3 ∙Py complex was added to DMF/LiCl with -SO 3 /-OH ratio of 1.5:1 and maintained at 50 °C for 3 h. Degree of polymerization of xylan was decreased during the sulfation process and DMF/LiCl offered the least xylan degradation as compared with DMSO/LiCl or FA/LiCl. Anticoagulant activities of the resultant xylan sulfates with different DS were evaluated by using activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). Results indicated that the introducing of sulfate groups into xylan did endow the polysaccharides with anticoagulant activity. The APTT and TT of XS with DS of 1.20 reached 141 and 45.3 s at a dosage of 20 μg/mL, while the APTT and TT values for the blank sample were only 35.5 and 15.6 s. Furthermore, coagulation time was prolonged with the increase of DS and the concentration of XS. Our findings provide new insights into the value-added utilization of agricultural biomass.

Effects of ambient relative humidity and solvent properties on the electrospinning of pure hyaluronic acid nanofibers.

PubMed

Yao, Shenglian; Wang, Xiumei; Liu, Xi; Wang, Ronghan; Deng, Changsheng; Cuil, Fuzhai

2013-07-01

Nanofibers exist ubiquitously in natural extracellular matrix (ECM) of all kinds of human tissues forming hydrated interwoven network. Electrospinning nanotechnology has been proven to be a powerful technique to fabricate controllable nanofibers mimicking the natural ECM structures. Hyaluronic acid (HA), as a critical component of natural ECM, has been widely used in tissue engineering and regenerative medicine. In this study, pure HA nanofibers with average diameter of 33 +/- 5 nm, 59 +/- 12 nm, 79 +/- 12 nm and 113 +/- 19 nm were successfully prepared using different electrospinning parameters. The effect of the ambient relative humidity on HA electrospinnability was investigated for the first time in detail, which was proven to be one of the most important factors to control the morphology of HA nanofibers beside the solution properties. A critical value of humidity for a defined HA solution was observed, only below which HA nanofibers with similar diameters and morphologies could be successfully obtained. When the ambient relative humidity was higher than the critical value, the HA nanofibers started dissolving at the cross points and even fused together forming a spreading layer. Moreover, only a small amount of N, N-Dimethylformamide (DMF) was found to be required to promote the electrospinnability of HA solution by mixing with water as solvents. With the increase in the DMF content, the surface tension of the solution decreased significantly, which was thought to be benefit for the stable Taylor cone and fluid jet formation in electrospinning. At the same time, it should be noted that the conductivity of the solution also decreased with the increase of DMF content in the solution, which was believed to be responsible for the increasing diameters of HA nanofibers corresponding to higher DMF content. Controllable HA nanofibers with diameter below 100 nm have great promising for developing novel nanobiomaterials applied in tissue engineering and regenerative medicine.

Formation of vinyl halides via a ruthenium-catalyzed three-component coupling.

PubMed

Trost, Barry M; Pinkerton, Anthony B

2002-06-26

The ruthenium-catalyzed three-component coupling of an alkyne, an enone, and halide ion to form E- or Z-vinyl halides has been investigated. Through systematic optimization experiments, the conditions effecting the olefin selectivity were examined. In general, more polar solvents such as DMF favored the formation of the E-isomer, and less polar solvents such as acetone favored formation of the Z-isomer. The optimized conditions for the formation of E-vinyl chlorides were found to be the use of cyclopentadienyl ruthenium (II) cyclooctadiene chloride, stannic chloride pentahydrate as a cocatalyst, and for a chloride source, either ammonium chloride in DMF/water mixtures or tetramethylammonium chloride in DMF. A range of several other ruthenium (II) catalysts was also shown to be effective. A wide variety of vinyl chlorides could be formed under these conditions. Substrates with tethered alcohols or ketones either five or six carbons from the alkyne portion gave instead diketone or cyclohexenone products. For formation of vinyl bromides, a catalyst system involving the use of cyclopentadienylruthenium (II) tris(acetonitrile) hexafluorophosphate with stannic bromide as a cocatalyst was found to be most effective. The use of ammonium bromide in DMF/acetone mixtures was optimal for the synthesis of E-vinyl bromides, and the use of lithium bromide in acetone was optimal for formation of the corresponding Z-isomer. Under either set of conditions, a wide range of vinyl bromides could be formed. When alkynes with propargylic substituents are used, enhanced selectivity for formation of the Z-isomer is observed. When aryl acetylenes are used as the coupling partners, complete selectivity for the Z-isomer is obtained. A mechanism involving a cis or trans halometalation is invoked to explain formation of the observed products. The vinyl halides have been shown to be precursors to alpha-hydroxy ketones and cyclopentenones, and as coupling partners in Suzuki-type reactions.

Application of pharmacogenomics to investigate adverse drug reactions to the disease-modifying treatments for multiple sclerosis: a case-control study protocol for dimethyl fumarate-induced lymphopenia.

PubMed

Kowalec, Kaarina; Kingwell, Elaine; Carruthers, Robert; Marrie, Ruth Ann; Bernatsky, Sasha; Traboulsee, Anthony; Ross, Colin J D; Carleton, Bruce; Tremlett, Helen

2017-06-02

Adverse drug reactions (ADRs) are a global public health issue. The potential for pharmacogenomic biomarkers has been demonstrated in several therapeutical areas, including HIV infection and oncology. Dimethyl fumarate (DMF) is a licensed disease-modifying therapy for the treatment of multiple sclerosis (MS). The use of DMF in MS has been associated with a severe reduction in lymphocyte counts and reports of progressive multifocal leukoencephalopathy. Here, we outline the protocol for a case-control study designed to discover genomic variants associated with DMF-induced lymphopenia. The ultimate goal is to replicate these findings and create an efficient and adaptable approach towards the identification of genomic markers that could assist in mitigating adverse drug reactions in MS. The population sample will comprise DMF-exposed patients with MS, with cases representing those who developed lymphopenia and controls who did not. DNA genotyping will take place using a high-throughput genome-wide array. Fine mapping and imputation will be performed to focus in on the potentially causal variants associated with lymphopenia. Multivariable logistic regression will be used to compare genotype and allele frequencies between the cases and the controls, with consideration of potential confounders. The association threshold will be set at p<1.0×10 -5 for the discovery of genomic association analyses to select variants for replication. Ethics approval has been obtained from the respective research ethics board, which includes written informed consent. Findings will be disseminated widely, including at scientific conferences, via podcasts (targeted at both healthcare professionals as well as patients and the wider community), through patient engagement and other outreach community events, written lay summaries for all participants and formal publication in peer-reviewed scientific journals. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Migration behavior of organic dyes based on physicochemical properties of solvents as background electrolytes in non-aqueous capillary electrophoresis.

PubMed

Gu, Minjeong; Cho, Keunchang; Kang, Seong Ho

2018-07-27

The migration behavior of organic fluorescent dyes (i.e., crystal violet, methyl violet base, methyl violet B base, rhodamine 6G, and rhodamine B base) in non-aqueous capillary electrophoresis (NACE) was investigated by focusing on the physicochemical properties of various organic solvents [ethanol, methanol, 2-propanol, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO)] in background electrolyte (BGE). Laser-induced fluorescence (LIF) and UV/Vis detectors were employed to observe both the migration time of organic dyes and the electroosmotic flow (EOF) in NACE, respectively. As seen in conventional aqueous BGE, the mobility of EOF in organic solvents tended to rise when the ratio between the dielectric constant and the solvent's viscosity (ε/η) increased in accordance with Smoluchowski's equation. However, unlike the ε/η of pure organic solvents, the migration order of dyes changed as follows: methanol (60.0) > DMF (45.8) > ethanol (22.8) > DMSO (23.4) > 2-propanol (9.8). Since the amount of acetic acid added to balance the pH depends on the pK a of each solvent, EOF changed when the difference in the ε/η value was small. This resulted from the inhibition of mobility, and its difference was dependent on the ε/η of BGEs with high ionic strength. In particular, the actual mobility of dyes in DMF showed excellent compliance with the Debye-Hückel-Onsager (DHO) theory extended by Falkenhagen and Pitts, which enabled us to analyze all dyes within 15 min with excellent resolution (R s >  2.5) under optimum NACE conditions (10 mM sodium borate and 4661 mM acetic acid in 100% DMF, pH 4.5). In addition, the NACE method was successfully applied for analyzing commercially available ballpoint ink pens. Thus, these results could be used to anticipate the migration order of organic dyes in a 100% NACE separation system. Copyright © 2018 Elsevier B.V. All rights reserved.

Lanthanide-organic complexes based on polyoxometalates: Solvent effect on the luminescence properties

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

Tang Qun; Liu Shuxia, E-mail: liusx@nenu.edu.cn; Liang Dadong

2012-06-15

A series of lanthanide-organic complexes based on polyoxometalates (POMs) [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}][W{sub 6}O{sub 19}] (Ln=La(1), Ce(2), Sm(3), Eu(4), Gd(5); DNBA=3,5-dinitrobenzoate; DMF=N,N-dimethylformamide) has been synthesized. These complexes consist of [W{sub 6}O{sub 19}]{sup 2-} and dimeric [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}]{sup 2+} cations. The luminescence properties of 4 are measured in solid state and different solutions, respectively. Notably, the emission intensity increases gradually with the increase of solvent permittivity, and this solvent effect can be directly observed by electrospray mass spectrometry (ESI-MS). The analyses of ESI-MS show that the eight coordinated solvent DMF units of dimeric cation are active. They can movemore » away from dimeric cations and exchange with solvent molecules. Although the POM anions escape from 3D supramolecular network, the dimeric state structure of [Ln{sub 2}(DNBA){sub 4}]{sup 2+} remains unchanged in solution. The conservation of red luminescence is attributed to the maintenance of the aggregated state structures of dimeric cations. - Graphical abstract: 3D POMs-based lanthanide-organic complexes performed the solvent effect on the luminescence property. The origin of such solvent effect can be understood and explained on the basis of the existence of coordinated active sites by the studies of ESI-MS. Highlights: Black-Right-Pointing-Pointer The solvent effect on the luminescence property of POMs-based lanthanide-organic complexes. Black-Right-Pointing-Pointer ESI-MS analyses illuminate the correlation between the structure and luminescence property. Black-Right-Pointing-Pointer The dimeric cations have eight active sites of solvent coordination. Black-Right-Pointing-Pointer The aggregated state structure of dimer cation remains unchanged in solution. Black-Right-Pointing-Pointer Luminescence associating with ESI-MS is a new method for investigating the interaction of complex and solvent.« less

Influence of cryoprotectants glycerol and amides, combined with antioxidants on quality of frozen-thawed boar sperm.

PubMed

Buranaamnuay, K; Grossfeld, R; Struckmann, C; Rath, D

2011-08-01

The present study was undertaken to examine whether the cooling and freezing extenders containing a mixture of antioxidants (AOs) catalase, Na-pyruvate and mercaptoethanol and one of three types of cryoprotectants (CPs) would be able to improve the quality of frozen-thawed boar sperm. The collected semen, only the sperm-rich fraction, was diluted 1:1 with Androhep plus™ extender, stored at 15°C for 2 h and centrifuged. The centrifuged sperm pellet was re-suspended in lactose-egg yolk extender and divided into four groups for mixing with freezing extenders containing different kinds of CPs at 5°C: (I) glycerol (GLY) as control; (II) GLY with AOs; (III) dimethyl formamide (DMF) with AOs and (IV) dimethyl acetamide (DMA) with AOs. Processed sperm were packaged in 0.25-mL straws and frozen using a controlled rate freezer. After thawing, the diluted thawed sperm were incubated at 38°C for 10 min and was assessed for motility by CASA, membrane/acrosome integrity by FITC-PNA/PI and DNA integrity (DFI) by SCSA. All sperm parameters evaluated, except DFI, were negatively affected (P<0.001) when using DMF (III) or DMA (IV) as CPs instead of GLY (I and II). Total sperm motility was lower (P<0.001) in the samples supplemented with AOs (32.4 ± 1.2, 23.9 ± 1.5, 6.9 ± 0.7, and 10.3 ± 0.9%, for treatments I, II, III and IV, respectively). The quality of sperm frozen in DMF was not different from DMA (P>0.05). There was no difference in DFI among the studied groups (P>0.05). In conclusion, based on the present results, addition of AOs to cooling and freezing extenders and/or replacement of GLY with DMF or DMA could not improve quality of frozen-thawed boar sperm. Copyright © 2011 Elsevier B.V. All rights reserved.

Solvent-Induced Cadmium(II) Metal-Organic Frameworks with Adjustable Guest-Evacuated Porosity: Application in the Controllable Assembly of MOF-Derived Porous Carbon Materials for Supercapacitors.

PubMed

Yue, Man-Li; Jiang, Yi-Fan; Zhang, Lin; Yu, Cheng-Yan; Zou, Kang-Yu; Li, Zuo-Xi

2017-11-07

In this work, five new cadmium metal-organic frameworks (Cd-MOFs 1-5) have been synthesized from solvothermal reactions of Cd(NO 3 ) 2 ⋅4 H 2 O with isophthalic acid and 1,4-bis(imidazol-1-yl)-benzene under different solvent systems of CH 3 OH, C 2 H 5 OH, (CH 3 ) 2 CHOH, DMF, and N-methyl-2-pyrrolidone (NMP), respectively. Cd-MOF 1 shows a 3D diamondoid framework with 1D rhombic and hexagonal channels, and the porosity is 12.9 %. Cd-MOF 2 exhibits a 2D (4,4) layer with a 1D parallelogram channel and porosity of 23.6 %. Cd-MOF 3 has an 8-connected dense network with the Schäfli symbol of [4 24 ⋅6 4 ] based on the Cd 6 cluster. Cd-MOFs 4-5 are isomorphous, and display an absolutely double-bridging 2D (4,4) layer with 1D tetragonal channels and porosities of 29.2 and 28.2 %, which are occupied by DMF and NMP molecules, respectively. Followed by the calcination-thermolysis procedure, Cd-MOFs 1-5 are employed as precursors to prepare MOF-derived porous carbon materials (labeled as PC-me, PC-eth, PC-ipr, PC-dmf and PC-nmp), which have the BET specific surface area of 23, 51, 10, 122, and 96 m 2  g -1 , respectively. The results demonstrate that the specific surface area of PCs is tuned by the porosity of Cd-MOFs, where the later is highly dependent on the solvent. Thereby, the specific surface area of PCs could be adjusted by the solvent used in the synthese of MOF precusors. Significantly, PCs have been further activated by KOH to obtain activated carbon materials (APCs), which possess even higher specific surface area and larger porosity. After a series of characterization and electrochemical investigations, the APC-dmf electrode exhibits the best porous properties and largest specific capacitances (153 F g -1 at 5 mV s -1 and 156 F g -1 at 0.5 Ag -1 ). Meanwhile, the APC-dmf electrode shows excellent cycling stability (ca. 84.2 % after 5000 cycles at 1 Ag -1 ), which can be applied as a suitable electrode material for supercapacitors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, Crystal Structures, Magnetic Properties, and Theoretical Investigation of a New Series of NiII-LnIII-WV Heterotrimetallics: Understanding the SMM Behavior of Mixed Polynuclear Complexes.

PubMed

Vieru, Veacheslav; Pasatoiu, Traian D; Ungur, Liviu; Suturina, Elizaveta; Madalan, Augustin M; Duhayon, Carine; Sutter, Jean-Pascal; Andruh, Marius; Chibotaru, Liviu F

2016-12-05

The polynuclear compounds containing anisotropic metal ions often exhibit efficient barriers for blocking of magnetization at fairly arbitrary geometries. However, at variance with mononuclear complexes, which usually become single-molecule magnets (SMM) under the sole requirement of a highly axial crystal field at the metal ion, the factors influencing the SMM behavior in polynuclear complexes, especially, with weakly axial magnetic ions, still remain largely unrevealed. As an attempt to clarify these conditions, we present here the synthesis, crystal structures, magnetic behavior, and ab initio calculations for a new series of Ni II -Ln III -W V trimetallics, [(CN) 7 W(CN)Ni(H 2 O)(valpn)Ln(H 2 O) 4 ]·H 2 O (Ln = Y 1, Eu 2, Gd 3, Tb 4, Dy 5, Lu 6). The surprising finding is the absence of the magnetic blockage even for compounds involving strongly anisotropic Dy III and Tb III metal ions. This is well explained by ab initio calculations showing relatively large transversal components of the g-tensor in the ground exchange Kramers doublets of 1 and 4 and large intrinsic tunneling gaps in the ground exchange doublets of 3 and 5. In order to get more insight into this behavior, another series of earlier reported compounds with the same trinuclear [W V Ni II Ln III ] core structure, [(CN) 7 W(CN)Ni(dmf)(valdmpn)Ln(dmf) 4 ]·H 2 O (Ln = Gd III 7, Tb III 8a, Dy III 9, Ho III 10), [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Tb(dmf) 2.5 (H 2 O) 1.5 ]·H 2 O·0.5dmf 8b, and [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Er(dmf) 3 (H 2 O) 1 ]·H 2 O·0.5dmf 11, has been also investigated theoretically. In this series, only 8b exhibits SMM behavior which is confirmed by the present ab initio calculations. An important feature for the entire series is the strong ferromagnetic coupling between Ni(II) and W(V), which is due to an almost perfect trigonal dodecahedron geometry of the octacyano wolframate fragment. The reason why only 8b is an SMM is explained by positive zero-field splitting on the nickel site, precluding magnetization blocking in complexes with fewer axial Ln ions. Further analysis has shown that, in the absence of ZFS on Ni ion, all compounds in the two series (except those containing Y and Gd) would be SMMs. The same situation arises for perfectly axial ZFS on Ni(II) with the main anisotropy axis parallel to the main magnetic axis of Ln(III) ions. In all other cases the ZFS on Ni(II) will worsen the SMM properties. The general conclusion is that the design of efficient SMMs on the basis of such complexes should involve isotropic or weekly anisotropic metal ions, such as Mn(II), Fe(III), etc., along with strongly axial lanthanides.

Prevalence of plaque and dental decay in the first permanent molar in a school population of south Mexico City.

PubMed

Taboada-Aranza, Olga; Rodríguez-Nieto, Karen

2018-01-01

The first permanent molar is susceptible to acquire tooth decay since its eruption, due to its anatomy and because it has been exposed before other teeth. An observational, prolective, transversal and comparative study in 194 students, with an average age of 9.9 ± 1.8 years. The evaluation of the dentobacterial plate (DBP) was analyzed using the O'Leary index and the tooth decay experience with the DMFS (sum of decayed, missing, extracted and filling dental surfaces) and DMFT (sum of decayed, missing, extracted and filling per tooth) indexes. The prevalence of DBP in the first permanent molar was of 99.4% and tooth decay of 57.2%. The value of DMFT was 1.4 ± 1.4. The tooth decay experience was higher in children from 7.10 years old with a value of 2.2 ± 2.3, who are 7.9 times more likely to develop lesions than younger children (odds ratio: 8.9; 95% confidence interval: 4.1-19.5; p < 0.0001). We found an association between age and the values of the tooth decay experience indexes; even though these were weak in the case of DMF (r = 0.439), the model allowed to explain 19% of the association, and 22% for DMFT (r = 0.464). Tooth decay develops rapidly in the first permanent molars; however, it does not receive the necessary care because it is usually unknown that it is a permanent tooth. Copyright: © 2018 Permanyer.

Absorption spectra of PTCDI: A combined UV-Vis and TD-DFT study

NASA Astrophysics Data System (ADS)

Oltean, Mircea; Calborean, Adrian; Mile, George; Vidrighin, Mihai; Iosin, Monica; Leopold, Loredana; Maniu, Dana; Leopold, Nicolae; Chiş, Vasile

2012-11-01

Absorption spectra of PTCDI (3,4,9,10-perylene-tetracarboxylic-diimide) have been investigated in chloroform, N,N'-dimethylformamide (DMF) and dimethylsulfoxide (DMSO). While no signature of assembled PTCDI molecules is observed in chloroform solution, distinct bands assigned to their aggregation have been identified in DMF and DMSO solutions. PTCDI monomers show very similar absorption patterns in chloroform and DMSO solutions. Experimental data, including the vibronic structure of the absorption spectra were explained based on the Franck-Condon approximation and quantum chemical results obtained at PBE0-DCP/6-31+G(d,p) level of theory. Geometry optimization of the first excited state leads to a nice agreement between the calculated adiabatic transition energies and experimental data.

Nutritional or pharmacological activation of HCA(2) ameliorates neuroinflammation.

PubMed

Offermanns, Stefan; Schwaninger, Markus

2015-04-01

Neuroinflammation is a pathology common to many neurological diseases, including multiple sclerosis (MS) and stroke. However, therapeutic attempts to modulate neuroinflammation have proved difficult. Neuroinflammatory cells express HCA2, a receptor for the endogenous neuroprotective ketone body β-hydroxybutyrate (BHB) as well as for the drugs dimethyl fumarate (DMF) and nicotinic acid, which have established efficacy in the treatment of MS and experimental stroke, respectively. This review summarizes the evidence that HCA2 is involved in the therapeutic effects of DMF, nicotinic acid, and ketone bodies in reducing neuroinflammation. Furthermore, we discuss the mechanisms underlying the beneficial effects of HCA2 activation in neuroinflammatory diseases and the therapeutic potential of recently developed synthetic ligands of HCA2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of the Novel Type of Bimodal Ceramic Nanowires from Polymer and Composite Fibrous Mats

PubMed Central

Matysiak, Wiktor

2018-01-01

The purpose of this paper was to produce SiO2 and TiO2 nanowires via the electrospinning process from a polyvinylpyrrolidone (PVP)/Tetraethyl orthosilicate (TEOS)/Titanium (IV) butoxide (TNBT)/dimethylformamide (DMF) and ethanol (EtOH) solution. The as-obtained nanofibers were calcined at temperatures ranging from 400 °C to 600 °C in order to remove the organic phase. The one-dimensional ceramic nanostructures were studied using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) to analyze the influence of the used temperature on the morphology and structures of the obtained ceramic nanomaterials. In order to examine the chemical structure of the nanowires, energy dispersive spectrometry (EDX) and Fourier-Transform Infrared spectroscopy (FTIR) were used. The optical property analysis was performed on the basis of UV-Vis spectra of absorbance as a function of the wavelength. Using the modified Swanepoel method, which the authors proposed and the recorded absorbance spectra allowed to determine the banded refractive index n, real n′ and imaginary k part of the refractive index as a function of the wavelength, complex dielectric permeability ε, and real and imaginary part εr and εi of the dielectric permeability as a function of the radiation energy of the produced ceramic nanowires. PMID:29558456

Manufacturing process, characterization and optical investigation of amorphous 1D zinc oxide nanostructures

NASA Astrophysics Data System (ADS)

Matysiak, Wiktor; Tański, Tomasz; Zaborowska, Marta

2018-06-01

The purpose of this article was to produce amorphous ZnO nanowires via the electrospinning process from a polyvinylpyrrolidone (PVP)/zinc acetate dihydrate (Zn(COOH)2)/dimethylformamide (DMF) and ethanol (EtOH) solution. The as obtained nanofibers were calcined at temperatures ranging from 400 to 600 °C to remove the organic phase. The one-dimensional zinc oxide nanostructures were studied using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) to analyse the influence of the used temperature on the morphology and structures of the obtained ceramic nanomaterials. In order to examine the chemical structure of nanowires, the energy dispersive spectrometry (EDX) was used. Besides, a thermogravimetric analysis (TGA) was performed to show the polymer concentration loss in a function of temperature in order to obtain pure zinc oxide nanowires. The optical property analysis was performed on the basis of UV-vis spectra of absorbance as a function of the wavelength. Using the modified Swanepoel method, which the authors proposed, and the recorded absorbance spectra determined the banded refractive index n, real n‧ and imaginary k part of the refractive index as a function of the wavelength, complex dielectric permeability ɛ, real and imaginary part εr and εi of the dielectric permeability as a function of the radiation energy of the produced ZnO nanowires.

Oral Health and nutritional status in nursing home residents-results of an explorative cross-sectional pilot study.

PubMed

Ziebolz, Dirk; Werner, Christine; Schmalz, Gerhard; Nitschke, Ina; Haak, Rainer; Mausberg, Rainer F; Chenot, Jean-François

2017-01-31

This study was performed to assess oral and nutritional status of nursing home residents in a region of Lower Saxony, Germany. The aim was to show potential associations between oral status (dentate or edentulous), further anamnestic factors (dementia, age, smoking) and the risk for malnutrition in this population. In this observational cross-sectional pilot study of residents from four nursing homes Mini Nutritional Assessment (MNA), Body-Mass-Index (BMI), dental status (DMF-T) and periodontal situation (PSR ® /PSI) were recorded. Associations of recorded factors with oral health and nutritional status were examined in univariate and multivariate analysis. Eighty-seven residents participated in the study (mean age: 84.1 years; female: 72%, demented: 47%). Average BMI was 26.2 kg/m 2 ; according MNA 52% were at risk for malnutrition. 48% of the residents were edentulous, and the average DMF-T of dentulous was 25.0 (3.7) (D-T: 2.0 [3.1], M-T: 15.0 [8.3], F-T: 8.0 [7.4]); PSR ® /PSI 3 and 4 (need for periodontal treatment) showed 79% of residents. In univariate analysis dementia (OR 2.5 CI 95 1.1-5.6) but not being edentulous (OR 2.0 CI 95 0.8-5.8) were associated with being at risk for malnutrition. Dementia remained associated in multivariate analysis adjusting for age and sex, (OR 3.1 CI 95 1.2-8.2) and additionally being edentulous (OR 2.8 CI 95 1.1-7.3) became associated significantly. Furthermore, nursing home residents with dementia had more remaining teeth (OR 2.5 CI 95 1.1-5.9). Dementia was a stronger predictor for risk of malnutrition in nursing home residents than being edentulous. Further studies to elucidate the possible role of oral health as cofactor for malnutrition in dementia are needed.

Evaluation of Oral Health-Related Quality of Life to Assess Dental Treatment in Preschool Children with Early Childhood Caries: A Preliminary Study.

PubMed

Vollú, Ana Lúcia; da Costa, Maria da Encarnação Perez Requejo; Maia, Lucianne Cople; Fonseca-Gonçalves, Andréa

The oral health-related quality of life (OHRQoL) of preschool children with Early Childhood Caries (ECC) was used to assess the outcome of dental treatment. Children (3.56±1.31years) affected by ECC were selected. Anamnesis, clinical and radiographic exams were performed. Data about sociodemographic aspects, OHRQoL and dmf-t index were collected. The Brazilian version of Early Childhood Oral health Impact Scale (B-ECOHIS) was applied in two time intervals: before and after 30 days of treatment. B-ECOHIS scores and effect size (ES) were used to evaluate the OHRQoL of preschool children. The Student's-t test was used for comparison between the B-ECOHIS averages, considering the following aspects: gender, age, socioeconomic status, severity of caries and type of treatment. The mean dmf-t was 6.25±4.20 and no differences between boys (6.00±4.32) and girls (6.83±4.35) (p=0,942) were found. Pain and psychological problems among children and parents feeling upset and guilty were the most frequently reported impacts at baseline. There was a greater impact on girls (17.67±8.68) than on boys (13.30±10.53) (p<0.001); and on children younger than 4 years (16.71±9.96) (p<0.05). The highest B-ECOHIS scores were observed in treatments involving dental extractions and space maintainers. There was no difference between the total B-ECOHIS scores of subjects from middle (16.24±10.30) and lower socioeconomic classes (15.97±10.26). The total scores of B-ECOHIS and its domains decreased after 30-day follow-up. Dental rehabilitation of preschool children showed a large effect size for these subjects (ES=1.19) and their families (ES=1.00). Dental treatment resulted in significant improvement of the preschool children's OHRQoL.

Gold nanocages decorated biocompatible amine functionalized graphene as an efficient dopamine sensor platform.

PubMed

Daemi, Sahar; Ashkarran, Ali Akbar; Bahari, Ali; Ghasemi, Shahram

2017-05-15

Nanocomposite of gold nanocages and chemically modified graphene oxide (GNCs/CMG) was synthesized in N,N-dimethylformamide (DMF) for sensitive detection of dopamine (DA). DA is widely spread in central nervous system which can regulates essential body functions like movement and emotional behaviour. In this regard sensitive and fast detection of DA level in human body is still challenging considering its interference with other biomolecules in biological samples. CMG was synthesized through amine modification of graphene oxide (GO) with DMF at relatively high temperature followed by attachment of GNCs, fabricated using a galvanic replacement between silver nanocubes and HAuCl 4 solution in the DMF. X-ray diffraction (XRD) pattern of GNCs/CMG nanocomposite revealed high crystallization of GNCs attached to the graphene nanosheets and microscopic images revealed relatively uniform decoration of GNCs on the surface of CMG. Nanocomposite modified glassy carbon electrode (GNCs/CMG/GCE) was used to investigate the electrochemical behaviour of DA with cyclic voltammetry and amperometry techniques. The linear range for dopamine was between 0.1 and 80μM with a low detection limit of 0.02μM. Furthermore, GNCs/CMG/GCE exhibited satisfying reproducibility, long-term stability and high selectivity for DA detection in large amount of ascorbic acid with good results for determination in human serum samples. Copyright © 2017 Elsevier Inc. All rights reserved.

The assessment of sIgA, histatin-5, and lactoperoxidase levels in saliva of adolescents with dental caries

PubMed Central

Gornowicz, Agnieszka; Tokajuk, Grażyna; Bielawska, Anna; Maciorkowska, Elżbieta; Jabłoński, Robert; Wójcicka, Anna; Bielawski, Krzysztof

2014-01-01

Background Saliva contains a number of protective factors such as mucins, immunoglobulins (e.g., IgA, IgG, and IgM), and enzymes (e.g., lysozyme and lactoperoxidases) that play an important role in the maintenance of oral health. The aim of this study was to compare levels of sIgA, histatin-5, and lactoperoxidase in saliva of adolescents with dental caries. Material/Methods Thirty-five adolescents (age 18 years) from high school were examined. Eight subjects with DMF=3 (Group I) and 27 adolescents with DMF>11 (Group II) were enrolled for this study. Clinical evaluation procedures comprised oral examination (including tooth, periodontal, and oral mucosal status) and collection of saliva samples. Saliva was collected for enzyme-linked immunosorbent assay (ELISA) and was used for determination of sIgA, histatin-5, and lactoperoxidase levels. Results Our results showed that adolescents with very high intensity of dental caries (DMF>11) had increased levels of sIgA, histatin-5, and lactoperoxidase compared to adolescents with lower intensity of caries. The increase was statistically significant (p<0.05). Conclusions We suggest that high intensity of caries is associated with increased levels of some salivary components – sIgA, histatin-5 and lactoperoxidase – that possess strong bactericidal or bacteriostatic effects, resulting in aggregation of oral bacteria and their clearance from the oral cavity. PMID:24974109

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

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H{sub 2}ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H{sub 2}hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd{sub 2}(2,6-ndc){sub 2}(bpp)(DMF)]·2DMF (1) and [Cd{sub 3}(hmdb){sub 3}(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations inmore » 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.« less

Oral Multiple Sclerosis Drugs Inhibit the In vitro Growth of Epsilon Toxin Producing Gut Bacterium, Clostridium perfringens

PubMed Central

Rumah, Kareem R.; Vartanian, Timothy K.; Fischetti, Vincent A.

2017-01-01

There are currently three oral medications approved for the treatment of multiple sclerosis (MS). Two of these medications, Fingolimod, and Teriflunomide, are considered to be anti-inflammatory agents, while dimethyl fumarate (DMF) is thought to trigger a robust antioxidant response, protecting vulnerable cells during an MS attack. We previously proposed that epsilon toxin from the gut bacterium, Clostridium perfringens, may initiate newly forming MS lesions due to its tropism for blood-brain barrier (BBB) vasculature and central nervous system myelin. Because gut microbiota will be exposed to these oral therapies prior to systemic absorption, we sought to determine if these compounds affect C. perfringens growth in vitro. Here we show that Fingolimod, Teriflunomide, and DMF indeed inhibit C. perfringens growth. Furthermore, several compounds similar to DMF in chemical structure, namely α, β unsaturated carbonyls, also known as Michael acceptors, inhibit C. perfringens. Sphingosine, a Fingolimod homolog with known antibacterial properties, proved to be a potent C. perfringens inhibitor with a Minimal Inhibitory Concentration similar to that of Fingolimod. These findings suggest that currently approved oral MS therapies and structurally related compounds possess antibacterial properties that may alter the gut microbiota. Moreover, inhibition of C. perfringens growth and resulting blockade of epsilon toxin production may contribute to the clinical efficacy of these disease-modifying drugs. PMID:28180112

Perylene Diimide Based Fluorescent Dyes for Selective Sensing of Nitroaromatic Compounds: Selective Sensing in Aqueous Medium Across Wide pH Range.

PubMed

Hariharan, P S; Pitchaimani, J; Madhu, Vedichi; Anthony, Savarimuthu Philip

2016-03-01

Water soluble perylenediimide based fluorophore salt, N,N'-bis(ethelenetrimethyl ammoniumiodide)-perylene-3,4,9,10-tetracarboxylicbisimide (PDI-1), has been used for selective fluorescence sensing of picric acid (PA) and 4-nitroaniline (4-NA) in organic as well as aqueous medium across wide pH range (1.0 to 10.0). PDI-1 showed strong fluorescence in dimethylformamide (DMF) (Φf = 0.26 (DMF) and moderate fluorescence in water. Addition of picric acid (PA) and 4-nitroaniline (4-NA) into PDI-1 in DMF/aqueous solution selectively quenches the fluorescence. The concentration dependent studies showed decrease of fluorescence linearly with increase of PA and 4-NA concentration. The interference studies demonstrate high selectivity for PA and 4-NA. Interestingly, PDI-1 showed selective fluorescence sensing of PA and 4-NA across wide pH range (1.0 to 10.0). Selective fluorescence sensing of PA and 4-NA has also been observed with trifluoroacetate (PDI-2), sulfate (PDI-3) salt of PDI-1 as well as octyl chain substituted PDI (PDI-4) without amine functionality. These studies suggest that PA and 4-NA might be having preferential interaction with PDI aromatic core and quenches the fluorescence. Thus PDI based dyes have been used for selective fluorescent sensing of explosive NACs for the first time to the best our knowledge.

Synergistic effect of acidity and extraframework position in faujasite on renewable p-xylene production

PubMed Central

2018-01-01

p-Xylene is a commodity chemical used for the manufacture of plastic bottles and textiles. For the biomass-based route from 2,5-dimethylfuran (DMF) and ethylene, the properties of the catalyst such as acidity effect, product selectivity and catalyst activity play an important role. To determine the effect of acidity and extraframework position in faujasite zeolite on p-xylene selectivity, type Y (Si/Al = 40 and Si/Al = 2.55) and X (Si/Al = 1.25) zeolites containing the extraframework Lewis acids Na+, K+, Li+, Ag+ and Cu+, and a Brønsted acid-containing zeolite, HY (Si/Al = 40), were prepared and tested for p-xylene production under solvent-free conditions and at low conversions (less than 35%). Here it is reported that NaX zeolite catalyses DMF and ethylene conversion to p-xylene with 91% selectivity at 30% conversion, which is better than the 25% p-xylene selectivity obtained when using HY at similar conversion. ANOVA was used to show that there is a synergistic effect between acidity and extraframework position on the rate of p-xylene production. At 7% DMF conversion, Lewis acids were more selective than the Brønsted acid tested (50 versus 30% p-xylene selectivity). p-Xylene selectivity is optimal when using Lewis acids with moderate acidity and extraframework positions located in the faujasite supercage (sites II and III). PMID:29892435

Functional electrospun membranes

NASA Astrophysics Data System (ADS)

Ognibene, G.; Fragalà, M. E.; Cristaldi, D. A.; Blanco, I.; Cicala, G.

2016-05-01

In this study we combined electrospun PES nanofibers with ZnO nanostructures in order to obtain a hierarchical nanostructured hybrid material to be use for active water filtration membranes. It benefits of flexibility and high surface area of the polymeric nanofibers as well as of additional functionalities of ZnOnanostructures. First, randomly oriented nanofibers with diameters of 716nm ±365 nm were electrospun on a glass fibers substrate from a solution of PES and DMF-TOL(1:1). ZnO nanorods were grown onto the surface of electrospun PES fibers by a Chemical Bath Deposition (CBD) process. It was preceed by a seeding process necessary to form nucleation sites for the subsequent radially aligned growth of ZnO nanowires. The morfology of the fibers and the effect of the seeding time have been analysed by SEM. The amount of ZnO nanowires grown over electrospun nanofibers was determined as 45% by weight. The high purity and crystallinity of the asobtained products are confirmed by XRD since all reflection peaks can be indexed to hexagonal wurtzite ZnO.

[Dysbiosis and its consequences on oral cavity in children and adolescents].

PubMed

Suladze, T; Shishniashvili, T; Margvelashvili, V; Makhviladze, M

2015-05-01

Gastrointestinal tract (GIT) diseases in children are often accompanied by changes in oral cavity, which is caused by common function of GIT and oral cavity organs. During last years, the number of dysbiosis of various severities has dramatically increased, which directly affects the oral cavity - dental hard tissue mineralization, especially in children and adolescents. The aim of our study was to identify the frequency of dysbiosis in children and adolescents and its influence on dental and general health. 279 patients aged 1 - 17 years were examined. Examinations have shown, that in patients with I-II degree dysbiosis spread and intensity (DMF index) of dental caries is significantly lower - 58,2% and 2,7 intensity, compared to III-IV degree dysbiosis, where 71,8% have caries with 4,2 intensity. According to this, dental and general health status in children and adolescents is highly dependent on severity of GI tract pathologies, particularly on qualitative and/or quantitative content of microbyotes of GI tract.

Oral health status of women with high-risk pregnancies.

PubMed

Merglova, Vlasta; Hecova, Hana; Stehlikova, Jaroslava; Chaloupka, Pavel

2012-12-01

The aim of this study was to investigate the oral health status of women with high-risk pregnancies. A case-control study of 142 pregnant women was conducted. The case group included 81 pregnant women with high-risk pregnancies, while 61 women with normal pregnancies served as controls. The following variables were recorded for each woman: age, general health status, DMF, CPITN, and PBI index, amounts of Streptococcus mutans in the saliva and dental treatment needs. The Mann-Whitney test, Kruskal-Wallis test, t-test and chi-squared test were used for statistical analyses. Statistically significant differences were detected between the PBI indices and dental treatment needs of the two groups. Out of the entire study cohort, 77% of the women in the case group and 52% of the women in the control group required dental treatment. In this study, women with complications during pregnancy had severe gingivitis and needed more frequent dental treatment than those in the control group.

Interface architecture between TiO2/perovskite, perovskite/hole transport layer, and perovskite grain boundary(Conference Presentation)

NASA Astrophysics Data System (ADS)

Hayase, Shuzi; Hirotani, Daisuke; Moriya, Masahiro; Ogomi, Yuhei; Shen, Qing; Yoshino, Kenji; Toyoda, Taro

2016-09-01

In order to examine the interface structure of TiO2/perovskite layer, quartz crystal microbalance sensor (QCM) was used. On the QCM sensor, TiO2 layer was fabricated and the PbI2 solution in Dimethylformamide (DMF) was passed on the QCM sensor to estimate the adsorption density of the PbI2 on the titania2. The amount of PbI2 adsorption on TiO2 surface increased as the adsorption time and leveled off at a certain time. PbI2 still remained even after the solvent only (DMF) was passed on the TiO2 layer on QCM (namely rinsing with DMF), suggesting that the PbI2 was tightly bonded on the TiO2 surface. The bonding structure was found to be Ti-O-Pb linkage by XPS analysis. We concluded that the Ti-OH on the surface of TiO2 reacts with I-Pb-I to form Ti-O-Pb-I and HI (Fig.1 B). The surface trap density was measured by thermally stimulated current (TSC) method. Before the PbI2 passivation, the trap density of TiO2 was 1019 cm3. The trap density decreased to 1016/cm3 after the PbI2 passivation, suggesting that the TiO2 surface trap was passivated with I-Pb-I. The passivation density was tuned by the concentration of PbI2 in DMF, by which TiO2 layer was passivated. Perovskite solar cells were fabricated on the passivated TiO2 layer with various PbI2 passivation densities by one step process (mixture of PbI2 + MAI in DMF). It was found that Jsc increased with an increase in the Ti-O-Pb density. We concluded that the interface between TiO2 and perovskite layer has passivation structure consisting of Ti-O-Pb-I which decreases the trap density of the interfaces and supresses charge recombination. The effect of Cl anion on high efficiency is still controversial when perovskite layer is prepared by one step method from the mixture of MAI and PbCl2. It was found that adsorption density of PbCl2 on TiO2 surface was much higher than that of PbI2 from the experiment using QCM sensor. After the surface was washed with DMF, Cl and Pb were detected. These results suggest that the TiO2 surface was much more passivated by PbCl2 than by PbI2. This may explain partially the high efficiency when the perovskite layer was fabricated by one step process consisting of MAI and PbCl2 solution. We also observed that the crystal size increased with an increase in the amount of Cl anion which of course one of the explanation of the high efficiency. The interface of hole transport layer/perovskite layer, and between perovskite layer /perovskite layer (grain boundary) was passivated with organic amines. The passivation was also effective for increasing Voc and Jsc. This was explained by the results of transient absorption spectroscopy that the charge recombination time between hole transport payer/perovskite layer increased from 0.3 μsec to 60 μsec.

Toxicology of dimethyl and monomethyl derivatives of acetamide and formamide: a second update.

PubMed

Kennedy, Gerald L

2012-11-01

Dimethylacetamide (DMAC) and dimethylformamide (DMF) continue to be important, widely used solvents involved in a wide variety of industrial applications. As liquids with relatively low vapor pressures, contact with both the integumentary and respiratory systems is the main source of human exposure. Although airborne control levels for the workplace have been established and industrial hygiene practices to limit dermal contact have been put in place, use of these chemicals has been associated with occupational illness, mainly in Asia where new and expanded uses have led to overexposures. Thus an update of the basic toxicology data including tables indicating the dose/exposure response characteristics of both DMAC and DMF is currently important. Both chemicals are similar from a toxicology perspective. Human experience has generally shown the materials to be without adverse effect except under conditions where airborne and dermal controls were not properly applied. The use of urinary metabolite monitoring has successfully been employed to measure integrated dermal and inhalation worker exposure. The chemicals are not particularly toxic following acute exposure but high doses can produce damage to the liver, the organ which is first affected by these two chemicals. Repeated dose/exposure studies have characterized both the targets of toxicity and the doses required to produce changes by various routes of exposure. Higher doses of these materials can produce changes in developing systems, infrequently in experiments at doses in which the maternal animal is unaffected, thus care needs to be taken when exposures are to women of child-bearing age. The chemicals appear to be low in genetic activity and inhalation exposures have not shown the materials to produce tumors in rodents except with DMF in a situation in which aerosol formation was encountered. This presentation extends the two previous reviews and, like those, includes updated information on acetamide and formamide and their monomethyl derivatives as well as the commercially important DMAC and DMF. Since a large portion of the newer information deals with effects in humans and biomonitoring, these sections are presented at the start of this review.

Tris(1,10-phenanthroline-κ2 N,N′)nickel(II) hexa­oxido-μ-peroxido-disulfate­(VI) N,N-dimethyl­formamide disolvate monohydrate

PubMed Central

Harvey, Miguel Angel; Suarez, Sebastián; Doctorovich, Fabio; Baggio, Ricardo

2013-01-01

The asymmetric unit of the title complex, [Ni(C12H8N2)3]S2O8·2C3H7NO·H2O, consists of a complex [Ni(phen)3]2+ cation and one isolated pds anion, with two DMF mol­ecules and one water mol­ecule as solvates (where phen is 1,10-phenanthroline, pds is the hexa­oxido-μ-peroxoido-di­sulf­ate dianion and DMF is dimethyl­formamide). The [Ni(phen)3]2+ cation is regular, with an almost ideal NiII bond-valence sum of 2.07 v.u. The group, as well as the water solvent mol­ecule, are well behaved in terms of crystallographic order, but the remaining three mol­ecules in the structure display different kinds of disorder, viz. the two DMF mol­ecules mimic a twofold splitting and the pds anion has both S atoms clamped at well-determined positions but with a not-too-well-defined central part. These peculiar behaviours are a consequence of the hydrogen-bonding inter­actions: the outermost SO3 parts of the pds anion are heavily connected to the complex cations via C—H⋯O hydrogen bonding, generating an [Ni(phen)3]pds network and providing for the stability of the terminal pds sites. Also, the water solvent mol­ecule is strongly bound to the structure (being a donor of two strong bonds and an acceptor of one) and is accordingly perfectly ordered. The peroxide O atoms in the pds middle region, instead, appear as much less restrained into their sites, which may explain their tendency to disorder. The cation–anion network leaves large embedded holes, amounting to about 28% of the total crystal volume, which are occupied by the DMF mol­ecules. The latter are weakly inter­acting with the rest of the structure, which renders them much more labile and, accordingly, prone to disorder. PMID:23476355

Properties of Oxygenates Found in Upgraded Biomass Pyrolysis Oil as Components of Spark and Compression Ignition Engine Fuels

DOE PAGES

McCormick, Robert L.; Ratcliff, Matthew A.; Christensen, Earl; ...

2015-03-01

We examined xxygenates present in partially hydroprocessed lignocellulosic-biomass pyrolysis oils for their impact on the performance properties of gasoline and diesel. These included: methyltetrahydrofuran, 2,5-dimethylfuran (DMF), 2-hexanone, 4-methylanisole, phenol, p-cresol, 2,4-xylenol, guaiacol, 4-methylguaiacol, 4-methylacetophenone, 4-propylphenol, and 4-propylguaiacol. Literature values indicate that acute toxicity for these compounds falls within the range of the components in petroleum-derived fuels. On the basis of the available data, 4-methylanisole and by extension other methyl aryl ethers appear to be the best drop-in fuel components for gasoline because they significantly increase research octane number and slightly reduce vapor pressure without significant negative fuel property effects. Amore » significant finding is that DMF can produce high levels of gum under oxidizing conditions. If the poor stability results observed for DMF could be addressed with a stabilizer additive or removal of impurities, it could also be considered a strong drop-in fuel candidate. The low solubility of phenol and p-cresol (and by extension, the two other cresol isomers) in hydrocarbons and the observation that phenol is also highly extractable into water suggest that these molecules cannot likely be present above trace levels in drop-in fuels. The diesel boiling range oxygenates all have low cetane numbers, which presents challenges for blending into diesel fuel. Moreover, there were some beneficial properties observed for the phenolic oxygenates in diesel, including increasing conductivity, lubricity, and oxidation stability of the diesel fuel. Oxygenates other than phenol and cresol, including other phenolic compounds, showed no negative impacts at the low blend levels examined here and could likely be present in an upgraded bio-oil gasoline or diesel blendstock at low levels to make a drop-in fuel. On the basis of solubility parameter theory, 4-methylanisole and DMF showed less interaction with elastomers than ethanol, while phenolic compounds showed somewhat greater interaction. This effect is not large, especially at low blend levels, and is also less significant as the size and number of alkyl substituents on the phenol ring increase.« less

The relationship of Prevotella intermedia, Prevotella nigrescens and Prevotella melaninogenica in the supragingival plaque of children, caries and oral malodor.

PubMed

Tanaka, Shoji; Yoshida, Mikako; Murakami, Yukio; Ogiwara, Takako; Shoji, Masao; Kobayashi, Satoko; Watanabe, Sigeru; Machino, Mamoru; Fujisawa, Seiichiro

2008-01-01

A relationship between the distribution of periodontal bacteria species and malodor in children has not been sufficiently investigated. The present study was undertaken to determine the presence of 3 periodontopathic bacteria (Prevotella spp. P. intermedia, P. nigrescens, P. melaninogenica) in the supragingival plaques of 3 to 16-year-old children with different oral health conditions and oral malodor. The number of decayed and filled primary teeth (df) and Decayed, Missing and Filled permanent teeth (DMF), Papillary Marginal and Attached gingivitis (PMA) index, Oral Hygiene Index (OHI), and oral malodor of each subject were determined prior to the collection of supragingival plaques. Three periodontopathic bacteria (P. intermedia, P. nigrescens, P. melaninogenica) in supragingival plaques were detected by using an immunoslot blot assay with monoclonal antibodies specific for each microorganism. The frequencies of periodontopathic bacteria in children with and without caries were not significantly different from each other. Positivity for P. intermedia, but not for P. nigrescens or P. melaninogenica was correlated with oral malodor. Oral malodor was also correlated with the debris index, a component of OHI. The group with the higher OHI showed a higher prevalence of periodontopathic bacteria. For the 3 periodontopathic bacteria in the subjects tested, plaques positive for any of them were not age related. However the frequencies of all 3 periodontopathic bacteria were the highest in the 3-6-year olds. The supragingival plaques in children can harbor 3 species of periodontopathic bacteria, P. intermedia, P. nigrescens, and P. melaninogenica.

Tunable and rapid self-assembly of block copolymers using mixed solvent vapors.

PubMed

Park, Woon Ik; Tong, Sheng; Liu, Yuzi; Jung, Il Woong; Roelofs, Andreas; Hong, Seungbum

2014-12-21

Pattern generation of well-controlled block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) is important for applications in sub-20 nm nanolithography. We used mixed solvents of dimethylformamide (DMF) and toluene to control the morphology as well as the time to achieve the targeted morphology via self-assembly of BCPs. By precisely controlling the volume ratio of DMF and toluene, well-ordered line, honeycomb, circular hole, and lamellar nanostructures were obtained from a cylinder-forming poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) BCP with high χ. Furthermore, a well-aligned 12 nm line pattern was successfully achieved in the guiding template within one minute using the mixed solvents. This practical method may also be applicable to self-assembly of other BCPs, providing more opportunities for the next-generation sub-10 nm lithography applications.

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

Ching-Yuan Chang; Wen-Tien Tsai; Horng-Chia Lee

Such thermodynamic properties as enthalpy, free energy, and entropy of adsorption have been computed for N,N-dimethylformamide (DMF) vapor on two commercial adsorbents: coconut shell Type PCB of activated carbon and Type DAY of hydrophobic zeolite. The computation is based on the Langmuir adsorption isotherms obtained at 293, 303, and 313 K as reported by Tsai et al. The laden adsorbents were regenerated with hot inert nitrogen gas and studied by thermal gravimetric analysis at three different heating rates. The apparent activation energies (E{sub des}) of thermal desorption were determined by using the Friedman method. The zeolite DAY has an adsorptionmore » potential higher than that of activated carbon PCB as indicated by the more negative value of the adsorption enthalpy of DMF vapor. The average value of E{sub des} of zeolite DAY is larger than that of activated carbon PCB.« less

A selective naked-eye chemosensor derived from 2-methoxybenzylamine and 2,3-dihydroxybenzaldehyde - synthesis, spectral characterization and electrochemistry of its bis-bidentates Schiff bases metal complexes

NASA Astrophysics Data System (ADS)

Djouhra, Aggoun; Ali, Ourari; Ramiro, Ruiz-Rosas; Emilia, Morallon

2017-09-01

A new colorimetric receptor HL, acting as a bidentate Schiff base ligand, has been synthesized by condensation of 2-methoxybenzylamine on 2,3-dihydroxybenzaldehyde in a methanolic solution. Interestingly, this chelating agent can selectively detect Cu2 +, Co2 +, Fe2 + and Fe3 + ions with a simple and an easy-to-make, well defined naked-eye visible color changes in two different solvents like acetonitrile and methanol. This bidentate ligand coordinates three metal ions of Co(II), Cu(II) and Fe(II) via nitrogen and oxygen atoms. The molecular structures of the synthesized compounds were elucidated by various physicochemical properties such as the elemental analysis, FT-IR, HNMR, UV-Vis and the Mass spectrometry. The resulting general formulae [M(L)2·H2O] (M(II) = Cu, Fe, Co) are proposed as mononuclear complexes. The solvatochromism properties of these compounds were studied with their absorption spectra using different solvents as methanol (MeOH), acetonitrile (AN), tetrahydrofuran (THF), dimethylformamid (DMF), dimethylsulfoxid (DMSO) and dichloromethane (DC). The Electrochemical behavior of copper complex was explored in DMF solutions by cyclic voltammetry (CV) with two working electrodes: glassy carbon (GC) and platinum electrode (Pt). This study reveals that copper complex shows successively two redox systems as CuIII/II and CuII/I. The FeIII/II and CoII/I redox systems have also been studied in DMF and DMSO media.

Dielectric anomaly and relaxation natures in a Zn-Cr pillar-layered metal-organic framework with cages and channels

NASA Astrophysics Data System (ADS)

Xue, Chen; Yao, Zhi-Yuan; Liu, Shao-Xian; Luo, Hong-Bin; Zou, Yang; Li, Li; Ren, Xiao-Ming

2017-06-01

A bimetallic metal-organic framework (MOF) with the formula [Zn3btc2{Cr3O(isonic)6(H2O)2(OH)}]·(DMF)15.5(H2O)8 (H3btc=1,3,5-benzenetricarboxylic acid; isonic=isonicotinicate) shows a pillar-layered structure. The monolayer consists of hexagon-like rings formed by the [Zn(isonic)2(btc)2] tetrahedral and the consecutive monolayers are pillared by trigonal-prismatic clusters of [Cr3O(isonic)6(H2O)2(OH)]through the remaining binding sites of the Zn2+ ions. DMF and water molecules are confined in the cages and channels. TGA indicates that the lattice DMF and water molecules begin to be released at temperatures above 363 K. Dielectric measurements were carried out in the range of 173-363 K and 1-107 Hz for three successive thermal cycles. The dielectric spectroscopy obtained in the first thermal cycle was different from that observed in the next two thermal cycles, while the dielectric spectra in the last two thermal cycles were almost identical. The dielectric nature of this MOF is discussed in detail for each thermal cycle. Since MOFs are unique host-guest systems in which the structure of the host framework is designable and the guests are exchangeable, it is no doubt those MOFs are materials with a variety of dielectric natures. This study gives a fresh impetus to achieve MOFs-based dielectric materials.

Highly-Selective and Reversible O₂ Binding in Cr₃(1,3,5-benzenetricarboxylate)₂

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

Murray, Leslie J; Dinca, Mircea; Yano, Junko

2010-06-16

Reaction of Cr(CO)₆ with trimesic acid in DMF affords the metal–organic framework Cr₃(BTC)₂∙nDMF (BTC 3- = 1,3,5-benzenetricarboxylate), which is isostructural to Cu₃(BTC)₂∙3H₂O. Exchanging DMF for methanol and heating at 160 °C under dynamic vacuum for 48 h results in the desolvated framework Cr₃(BTC)₂. Nitrogen gas adsorption measurements performed at 77 K revealed a type I isotherm, indicating BET and Langmuir surface areas of 1810 and 2040 m²/g, respectively. At 298 K, the O₂ adsorption isotherm for Cr₃(BTC)₂ rises steeply to a capacity of 11 wt % at 2 mbar, while the corresponding N₂ adsorption isotherm displays very little uptake, graduallymore » rising to a capacity of 0.58 wt % at 1 bar. Accordingly, the material displays an unprecedented O₂/N₂ selectivity factor of 22. Deoxygenation of the sample could be accomplished by heating at 50 °C under vacuum for 48 h, leading to a gradually diminishing uptake capacity over the course of 15 consecutive adsorption/desorption cycles. Infrared and X-ray absorption spectra suggest formation of an O₂ adduct with partial charge transfer from the Cr II centers exposed on the surface of the framework. Neutron powder diffraction data confirm this mechanism of O₂ binding and indicate a lengthening of the Cr–Cr distance within the paddle-wheel units of the framework from 2.06(2) to 2.8(1) Å.« less

Extracting natural dyes from wool--an evaluation of extraction methods.

PubMed

Manhita, Ana; Ferreira, Teresa; Candeias, António; Dias, Cristina Barrocas

2011-05-01

The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

Identification of Protein Succination as a Novel Modification of Tubulin

PubMed Central

Piroli, Gerardo G.; Manuel, Allison M.; Walla, Michael D.; Jepson, Matthew J.; Brock, Jonathan W.C.; Rajesh, Mathur P.; Tanis, Ross M.; Cotham, William E.; Frizzell, Norma

2015-01-01

Protein succination is a stable post-translational modification that occurs when fumarate reacts with cysteine residues to generate S-(2-succino)cysteine (2SC). We demonstrate that both alpha (α) and beta (β) tubulin are increasingly modified by succination in 3T3-L1 adipocytes and in the adipose tissue of db/db mice. Incubation of purified tubulin from porcine brain with fumarate (50 mM) or the pharmacological compound dimethylfumarate (DMF, 500 μM) inhibited polymerization up to 35% and 59%, respectively. Using mass spectrometry we identified Cys347α, Cys376α, Cys12β and Cys303β as sites of succination in porcine brain tubulin and the relative abundance of succination at these cysteines increased in association with fumarate concentration. The increase in succination after incubation with fumarate altered tubulin recognition by an anti-α-tubulin antibody. Succinated tubulin in adipocytes cultured in high glucose vs. normal glucose also had reduced reactivity with the anti-αtubulin antibody; suggesting that succination may interfere with tubulin:protein interactions. DMF reacted rapidly with 11 of the 20 cysteines in the αβ tubulin dimer, decreased the number of free sulfhydryls and inhibited the proliferation of 3T3-L1 fibroblasts. Our data suggests that inhibition of tubulin polymerization is an important, undocumented mechanism of action of DMF. Taken together, our results demonstrate that succination is a novel post-translational modification of tubulin and suggest that extensive modification by fumarate, either physiologically or pharmacologically, may alter microtubule dynamics. PMID:24909641

Using HST: From proposal to science

NASA Technical Reports Server (NTRS)

Shames, P.

1991-01-01

The following subject areas are covered: a short history; uses of network STSCII (general communication, science collaboration, functional activities, internal data management, and external data access); proposal/observation handling; DMF access; and future uses and requirements.

Harmonising production, properties and environmental consequences of liquid transport fuels from biomass--2,5-dimethylfuran as a case study.

PubMed

Simmie, John M; Würmel, Judith

2013-01-01

The rapid development in methods for transforming non-edible biomass into platform chemicals and fuels has accelerated over recent years. However, the determination of whether these 'next-generation' biofuels perform in a satisfactory manner in engines, turbines and burners has lagged behind. The evaluation of the ecological and toxicological aspects has also been unable to keep up. We show, by using 2,5-dimethylfuran (DMF) as a concrete example, how a range of studies is needed to establish the benefits and risks of using a particular biofuel. In this regard, the variable with the largest impact about which little is known is probably the behaviour of DMF when it is accidentally introduced into groundwater. A primary consideration is to avoid a repetition of the methyl tert-butyl ether (MTBE) fiasco. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, characterizations and catalytic studies of a new two-dimensional metal-organic framework based on Co-carboxylate secondary building units

NASA Astrophysics Data System (ADS)

Bagherzadeh, Mojtaba; Ashouri, Fatemeh; Đaković, Marijana

2015-03-01

A metal-organic framework [Co3(BDC)3(DMF)2(H2O)2] was synthesized and structurally characterized. X-ray single crystal analysis revealed that the framework contains a 2D polymeric chain through coordination of 1,4-benzenedicarboxylic acid linker ligand to cobalt centers. The polymer crystallize in monoclinic P21/n space group with a=13.989(3) Å, b=9.6728(17) Å, c=16.707(3) Å, and Z=2. The polymer features a framework based on the perfect octahedral Co-O6 secondary building units. The catalytic activities of [Co3(BDC)3(DMF)2(H2O)2]n for olefins oxidation was conducted. The heterogeneous catalyst could be facilely separated from the reaction mixture, and reused three times without significant degradation in catalytic activity. Furthermore, no contribution from homogeneous catalysis of active species leaching into reaction solution was detected.

Structural dynamics inside a functionalized metal–organic framework probed by ultrafast 2D IR spectroscopy

DOE PAGES

Nishida, Jun; Tamimi, Amr; Fei, Honghan; ...

2014-12-15

One key property of metal-organic frameworks (MOFs) are their structural elasticity. IHere we show that 2D IR spectroscopy with pulse-shaping techniques can probe the ultrafast structural fluctuations of MOFs. 2D IR data, obtained from a vibrational probe attached to the linkers of UiO-66 MOF in low concentration, revealed that the structural fluctuations have time constants of 7 and 670 ps with no solvent. Filling the MOF pores with dimethylformamide (DMF) slows the structural fluctuations by reducing the ability of the MOF to undergo deformations, and the dynamics of the DMF molecules are also greatly restricted. Finally, methodology advances were requiredmore » to remove the severe light scattering caused by the macroscopic-sized MOF particles, eliminate interfering oscillatory components from the 2D IR data, and address Förster vibrational excitation transfer.« less

Extending the lanthanide-terephthalate system: Isolation of an unprecedented Tb(III)-based coordination polymer with high potential porosity and luminescence properties

NASA Astrophysics Data System (ADS)

Le Natur, François; Calvez, Guillaume; Freslon, Stéphane; Daiguebonne, Carole; Bernot, Kevin; Guillou, Olivier

2015-04-01

A novel coordination polymer with chemical formula {[Tb(bdc)1.5(H2O)]ṡ(DMF)(H2O)}∞ (1) has been synthesized by reaction between 1,4-benzene-dicarboxylic acid (H2bdc) and di-cationic hexanuclear entity [Tb6O(OH)8(NO3)6(H2O)12]2+ in an ethylene glycol (EG)/N,N-dimethylformamide (DMF) mixture. This compound has been obtained as single crystals by slow evaporation in air at room temperature. If the hexanuclear entity is destroyed during the reaction, the coordination polymer that is obtained is original and presents promising potential micro-porosity and luminescent properties. It crystallizes in the monoclinic system, space group C12/c1 (No. 15) with the cell parameters a = 23.7540(1) Å, b = 10.5390(4) Å, c = 19.7580(3) Å, β = 125.8100(1)° and Z = 8.

Platinum(II) acetate complexes in hydrogenation of unsaturated compounds

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

Berenblyum, A.S.; Goranskaya, T.P.; Mund, S.L.

1979-12-20

In order to further elucidate the effect of the ligand environment in the complexes of group VIII metals on the activity of H/sub 2/, the catalytic properties of Pt(II) compounds with oxygen-containing acido ligands was studied. The platinum(II) acetate complexes with aniline and triphenylphosphine were synthesized. IR spectral studies indicated that platinum(II) acetate formed complexes with either of the other compounds singly or together. Dimethylformamide(DMF) solutions of platinum acetate and its complexes with aniline and/or triphenylphosphine all absorb H/sub 2/ in the temperature range of 20 to 90/sup 0/C and at a H/sub 2/ pressure of 1 atm. After themore » absorption of H/sub 2/, the DMF solutions of (aniline)(triphenylphosphine)platinum(II)diacetate complex were found to catalyze the hydrogenaton of O/sub 2/ and 1,3-pentadiene.« less

High yield synthesis of Ni-BTC metal-organic framework with ultrasonic irradiation: Role of polar aprotic DMF solvent.

PubMed

Israr, Farrukh; Chun, Daye; Kim, Yeongmin; Kim, Duk Kyung

2016-07-01

Nickel based porous solid was synthesized with 20 kHz ultrasonic irradiation. The reaction of Ni(II) nitrate hexahydrate with 1,3,5-benzene tricarboxylic acid in N,N-Dimethylformamide (DMF) as the sole solvent under ultrasonic radiation produced porous Ni-BTC MOF. Choice of correct solvent for the ultrasonic treatment was proven important. The effect of varying ultrasonic powers (40%, 60% and 80% of 750 W) along with different temperature conditions (50 °C, 60 °C, 70 °C and 80 °C) influenced the respective yield. A very high yield of 88% Ni-BTC MOF was obtained from 80% ultrasonic power at 60 °C. BET surface areas of the MOF crystals measured by N2 gas adsorption isotherms were in the range of 960-1000 m(2)/g. Copyright © 2015 Elsevier B.V. All rights reserved.

Desulfurization of Saudi Arabian crudes by oxidation-extraction method.

PubMed

Al Otaibi, Raja L; Liu, Dong; Hou, Xulian; Song, Linhua; Li, Qingyin; Li, Mengfei; Almigrin, Hamid O; Yan, Zifeng

The oxidation-extraction desulfurization of Saudi Arabian crudes was conducted with hydrogen peroxide-acetic acid oxidation system. The selection of extractant, the optimization of oxidation-extraction conditions, and the exploration of desulfurization mechanism were studied. As DMF was used as the extractant, the optimal desulfurization rate of 35.11 % and oil recovery of 95 % were obtained at 70 °C with the molar ratio of peracetic acid to sulfur of 8:1, the molar ratio of acetic acid to hydrogen peroxide of 2:1 and the volume ratio of extractant to oil of 1:1. The desulfurization effect of different fractions in the treated Saudi Arabian crudes was found to obey the following order: gasoline-diesel fraction >VGO fraction >VR fraction, due to different types and structures of sulfur compounds. The oil quality was less affected and most sulfides were mainly extracted via DMF.

Carbonate-based zeolitic imidazolate framework for highly selective CO2 capture.

PubMed

Basnayake, Sajani A; Su, Jie; Zou, Xiadong; Balkus, Kenneth J

2015-02-16

In this study, we report the formation of a new crystal structure, ZIF-CO3-1, which results from the reaction of Zn(2+), 2-methylimidazole, and carbonate. ZIF-CO3-1 can be synthesized solvothermally in N,N-dimethylformamide (DMF)/water (H2O) or by utilizing of CO2 gas at various temperatures in DMF/H2O or H2O. This reaction selectively consumes CO2 because CO2 is incorporated in the ZIF as carbonate. CO2 can be quantitatively released by acidifying the ZIF. Powder X-ray diffraction, single-crystal X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, elemental analysis, and thermogravimetric analysis were used to characterize the ZIF structure. ZIF-CO3-1 (chemical formula C9H10N4O3Zn2), crystallizes in the orthorhombic crystal system with noncentrosymmetric space group Pba2.

Natural sunlight irradiated flower-like CuS synthesized from DMF solvothermal treatment

NASA Astrophysics Data System (ADS)

Zhao, Wei; Wang, Zihao; Zhou, Lei; Liu, Nianqi; Wang, Hongxing

2016-09-01

Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process. The CuS microparticles showed different flower-like morphology and good dispersion by optimizing reaction conditions. It was found that using N,N-dimethylformamide (DMF) as the solvent reagent in the proper temperature conditions was favorable for the growth of hierarchically structured CuS. The hexagonal flower-like CuS synthesized at 170°C for 60 min displayed broad-spectrum photocatalytic properties under ultraviolet (UV) and visible irradiation. The as-prepared CuS crystals exhibited good performance to decolorize methylene blue (MB) solution under visible light irradiation. The total organic carbon (TOC) removal of rhodamine B (RhB) solution was nearly 60% after 5 h of the natural sunlight irradiation, and the property was stable after testing over four recycles, demonstrating a potential application in waster water treatment.

Sofa dermatitis.

PubMed

Schad, Karin; Nobbe, Stephan; French, Lars E; Ballmer-Weber, Barbara

2010-11-01

Furniture components can cause contact allergies. In the last years several cases of eczema after sofa contact have been reported. Typically the skin lesions develop on the back, the buttocks, the dorsal aspects of the thighs and arms and are often very resistant to topical corticoid therapy. Dimethylfumarate (DMF) is postulated to be the causative agent for this Type IV hypersensitivity reaction. DMF is an antimicrobial substance, which is used in asian upholstered furniture industry amongst others. We report the case of a 65-year old patient with generalised severely itching maculopapular, partly eczematous skin lesions on the buttocks, back, abdomen and arms. The resistance to therapy, several relapses after discharge from hospital as well as the detailed history lead us to the tentative diagnosis. The sofa dermatitis was proven by positive patch testing with furniture material and dimethylfumarate. © The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.

Solvation of decane and benzene in mixtures of 1-octanol and N, N-dimethylformamide

NASA Astrophysics Data System (ADS)

Kustov, A. V.; Smirnova, N. L.

2016-09-01

The heats of dissolution of decane and benzene in a model system of octanol-1 (OctOH) and N, N-dimethylformamide (DMF) at 308 K are measured using a variable temperature calorimeter equipped with an isothermal shell. Standard enthalpies are determined and standard heat capacities of dissolution in the temperature range of 298-318 K are calculated using data obtained in [1, 2]. The state of hydrocarbon molecules in a binary mixture is studied in terms of the enhanced coordination model (ECM). Benzene is shown to be preferentially solvated by DMF over the range of physiological temperatures. The solvation shell of decane is found to be strongly enriched with 1-octanol. It is obvious that although both hydrocarbons are nonpolar, the presence of the aromatic π-system in benzene leads to drastic differences in their solvation in a lipid-protein medium.

Supercritical CO2 extraction of beta-carotene from a marine strain of the cyanobacterium Synechococcus species.

PubMed

Montero, Olimpio; Macías-Sánchez, Maria Dolores; Lama, Carmen M; Lubián, Luis M; Mantell, Casimiro; Rodríguez, Miguel; de la Ossa, Enrique M

2005-12-14

Dynamic extraction of carotenoids from a marine strain of Synechococcus sp. (Cyanophyceae) with supercritical CO2 (SC-CO2) was investigated with regard to operation pressure and temperature effects on extraction efficiency. Extraction yield (milligrams of pigment per gram of dry weight) for SC-CO2) was compared with the extraction yield for dimethylformamide (DMF). Carotenoids extracted with SC-CO2 were beta-carotene (Ct), zeaxanthin (Z), beta-cryptoxanthin (Cr), and equinenone; chlorophyll a was poorly extracted, whereas myxoxanthophyll, another major carotenoid, was not extracted under any experimental condition. The highest relative yield, which is defined here as y(r) = [(mg of pigment(SC-CO2)/mg of pigment(DMF))] x 100, was 76.1 +/- 8.6% for Ct, but it rose to 87.0 +/- 3.4% when 15% ethanol was used as cosolvent. The pressure effect on y(r) was found to be significant (p < 0.05) for both Cr and Z, along with total carotenoids, whereas the effect of square T (TT) was significant for only Ct. From empirical correlations, pairwise pressure (bar) and temperature (degrees C), respectively, for optimal extraction were determined to be (358, 50) for Ct, (454, 59) for Cr, and (500, 60) for Z. Cell disruption by sonication or detergent treatment of the biomass did not improve the extraction efficiency. Matrix structure together with material state could explain the low carotenoid extraction yield obtained with SC-CO2 as compared to DMF in Synechococcus sp. However, the process can be applied to selective extraction of different carotenoids.

[Dental caries distribution in preschool children in an urban area of Argentina, 1992].

PubMed

Yankilevich, E R; Cattoni, S T; Cornejo, L S; Battellino, L J

1993-12-01

An investigation undertaken into a sample of 1,115 five-year old children attending kindergartens in the city of Córdoba (Argentina) is described. The investigation aimed at establishing the prevalence and distribution of dental caries by socioeconomic level. Research showed that the prevalence of caries had decreased 55.0% in relation to the 1973 figure, while the proportion of children with healthy teeth was 26.7% greater. The frequency and seriousness of the caries increased as the child's social position declined. At the highest socioeconomic level NES I = entrepreneurial and managerial bourgeoisie), the rates of caries were significantly lower than those at the lowest socioeconomic level (NES III = typical proletariat, nontypical proletariat and sub-proletariat) presenting dmf-t of 0.8 and 2.7, and dmf-s of 0.9 and 4.9, respectively. In NES III, the dmf-t main components were decayed and missing teeth, while in NES I filled teeth were the main components. The proportion of children with no experience of caries was 63.1% in NES I and 11.5% in NES III. Inversly, the rate dental health was higher in NES I (8.8) than in NES III (5.1). The cost per child required for the restorative treatment in approximately two and a half times greater in NES III than in NES I. Considering the sample as a whole the expenditure required for NES III would be more than ten times higher than that required for NES I.(ABSTRACT TRUNCATED AT 250 WORDS)

Four unprecedented 2D trinuclear Mn(II)-complexes with adenine nucleobase controlled by solvent or co-ligand: Hydrothermal synthesis, crystal structure and magnetic behaviour

NASA Astrophysics Data System (ADS)

Zhao, Hongkun; He, Hongming; Wang, Xiuguang; Liu, Zhongyi; Ding, Bo; Yang, Hanwen

2018-03-01

Four unique infinite 2D Mn(II) aggregates, [Mn3(μ3-ade)2(OAc)4X]n (X = DMF for 1, DMA for 2 and C2H5O- for 3), [Mn3(μ3-ade)2(ap)2DMF]n (4) (Hade = adenine; DMF = N,N-dimethylformamide; DMA = N,N-dimethylacetamide, OAc- = acetate ion, H2ap = adipic acid) with trinuclear Mn(II) as secondary building units (SBUs), have been successfully synthesized by the assembly of Hade nucleobase and manganese acetate under solvothermal conditions. The resultant complexes can be applied to explore the influence of solvent or co-ligands on the self-assembly and properties of metal complexes based on adenine. The Hade represent tridentate μ3-N3, N7, N9 bridging coordination modes. The acetate anions exhibit μ2-η1:η1 bidentate, μ2-η1:η2 tridentate mode, and μ2-η0:η2 bidentate mode. The adipate anions in complex 4 adopt two coordination modes: one is μ4-η2:η1:η1:η1 pentadentate mode, the other one is μ3-η1:η2:η2:η1 hexadentate mode. Their magnetic behaviors exhibit interesting variations, in which the local net magnetization at low temperature increases from 1 to 3. The MnII3 SBUs in 1-3 are symmetric with an inversion center, whereas that in 4 has three crystallographically independent MnII atoms. Thus, the magnetic behaviors of 4 are different from complex 1-3.

Temperature dependence measurements and structural characterization of trimethyl ammonium ionic liquids with a highly polar solvent.

PubMed

Attri, Pankaj; Venkatesu, Pannuru; Hofman, T

2011-08-25

We report the synthesis and characterization of a series of an ammonium ionic liquids (ILs) containing acetate, dihydrogen phosphate, and hydrogen sulfate anions with a common cation. To characterize the thermophysical properties of these newly synthesized ILs with the highly polar solvent N,N-dimethylformamide (DMF), precise measurements such as densities (ρ) and ultrasonic sound velocities (u) over the whole composition range have been performed at atmospheric pressure and over wide temperature ranges (25-50 °C). The excess molar volume (V(E)) and the deviation in isentropic compressibilities (Δκ(s)) were predicted using these temperature dependence properties as a function of the concentration of ILs. The Redlich-Kister polynomial was used to correlate the results. The ILs investigated in the present study included trimethylammonium acetate [(CH(3))(3)NH][CH(3)COO] (TMAA), trimethylammonium dihydrogen phosphate [(CH(3))(3)NH][H(2)PO(4)] (TMAP), and trimethylammonium hydrogen sulfate [(CH(3))(3)NH][HSO(4)] (TMAS). The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. In addition, the hydrogen bonding between ILs and DMF has been demonstrated using semiempirical calculations with help of Hyperchem 7. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and DMF molecules and their structural factors. The influence of the anion of the protic IL, namely, acetate (CH(3)COO), dihydrogen phosphate (H(2)PO(4)), and hydrogen sulfate (HSO(4)), on the thermophysical properties is also provided. © 2011 American Chemical Society

Direct electrochemistry and electrocatalysis of heme proteins immobilised in carbon-coated nickel magnetic nanoparticle-chitosan-dimethylformamide composite films in room-temperature ionic liquids.

PubMed

Wang, Ting; Wang, Lu; Tu, Jiaojiao; Xiong, Huayu; Wang, Shengfu

2013-12-01

The direct electrochemistry and electrocatalysis of heme proteins entrapped in carbon-coated nickel magnetic nanoparticle-chitosan-dimethylformamide (CNN-CS-DMF) composite films were investigated in the hydrophilic ionic liquid [bmim][BF4]. The surface morphologies of a representative set of films were characterised via scanning electron microscopy. The proteins immobilised in the composite films were shown to retain their native secondary structure using UV-vis spectroscopy. The electrochemical performance of the heme proteins-CNN-CS-DMF films was evaluated via cyclic voltammetry and chronoamperometry. A pair of stable and well-defined redox peaks was observed for the heme protein films at formal potentials of -0.151 V (HRP), -0.167 V (Hb), -0.155 V (Mb) and -0.193 V (Cyt c) in [bmim][BF4]. Moreover, several electrochemical parameters of the heme proteins were calculated by nonlinear regression analysis of the square-wave voltammetry. The addition of CNN significantly enhanced not only the electron transfer of the heme proteins but also their electrocatalytic activity toward the reduction of H2O2. Low apparent Michaelis-Menten constants were obtained for the heme protein-CNN-CS-DMF films, demonstrating that the biosensors have a high affinity for H2O2. In addition, the resulting electrodes displayed a low detection limit and improved sensitivity for detecting H2O2, which indicates that the biocomposite film can serve as a platform for constructing new non-aqueous biosensors for real detection. Copyright © 2013 Elsevier B.V. All rights reserved.

A droplet-to-digital (D2D) microfluidic device for single cell assays.

PubMed

Shih, Steve C C; Gach, Philip C; Sustarich, Jess; Simmons, Blake A; Adams, Paul D; Singh, Seema; Singh, Anup K

2015-01-07

We have developed a new hybrid droplet-to-digital microfluidic platform (D2D) that integrates droplet-in-channel microfluidics with digital microfluidics (DMF) for performing multi-step assays. This D2D platform combines the strengths of the two formats-droplets-in-channel for facile generation of droplets containing single cells, and DMF for on-demand manipulation of droplets including control of different droplet volumes (pL-μL), creation of a dilution series of ionic liquid (IL), and parallel single cell culturing and analysis for IL toxicity screening. This D2D device also allows for automated analysis that includes a feedback-controlled system for merging and splitting of droplets to add reagents, an integrated Peltier element for parallel cell culture at optimum temperature, and an impedance sensing mechanism to control the flow rate for droplet generation and preventing droplet evaporation. Droplet-in-channel is well-suited for encapsulation of single cells as it allows the careful manipulation of flow rates of aqueous phase containing cells and oil to optimize encapsulation. Once single cell containing droplets are generated, they are transferred to a DMF chip via a capillary where they are merged with droplets containing IL and cultured at 30 °C. The DMF chip, in addition to permitting cell culture and reagent (ionic liquid/salt) addition, also allows recovery of individual droplets for off-chip analysis such as further culturing and measurement of ethanol production. The D2D chip was used to evaluate the effect of IL/salt type (four types: NaOAc, NaCl, [C2mim] [OAc], [C2mim] [Cl]) and concentration (four concentrations: 0, 37.5, 75, 150 mM) on the growth kinetics and ethanol production of yeast and as expected, increasing IL concentration led to lower biomass and ethanol production. Specifically, [C2mim] [OAc] had inhibitory effects on yeast growth at concentrations 75 and 150 mM and significantly reduced their ethanol production compared to cells grown in other ILs/salts. The growth curve trends obtained by D2D matched conventional yeast culturing in microtiter wells, validating the D2D platform. We believe that our approach represents a generic platform for multi-step biochemical assays such as drug screening, digital PCR, enzyme assays, immunoassays and cell-based assays.

Photochemistry in a 3D metal-organic framework (MOF): monitoring intermediates and reactivity of the fac-to-mer photoisomerization of Re(diimine)(CO)3Cl incorporated in a MOF.

PubMed

Easun, Timothy L; Jia, Junhua; Calladine, James A; Blackmore, Danielle L; Stapleton, Christopher S; Vuong, Khuong Q; Champness, Neil R; George, Michael W

2014-03-03

The mechanism and intermediates in the UV-light-initiated ligand rearrangement of fac-Re(diimine)(CO)3Cl to form the mer isomer, when incorporated into a 3D metal-organic framework (MOF), have been investigated. The structure hosting the rhenium diimine complex is a 3D network with the formula {Mn(DMF)2[LRe(CO)3Cl]}∞ (ReMn; DMF = N,N-dimethylformamide), where the diimine ligand L, 2,2'-bipyridine-5,5'-dicarboxylate, acts as a strut of the MOF. The incorporation of ReMn into a KBr disk allows spatial distribution of the mer-isomer photoproduct in the disk to be mapped and spectroscopically characterized by both Fourier transform infrared and Raman microscopy. Photoisomerization has been monitored by IR spectroscopy and proceeds via dissociation of a CO to form more than one dicarbonyl intermediate. The dicarbonyl species are stable in the solid state at 200 K. The photodissociated CO ligand appears to be trapped within the crystal lattice and, upon warming above 200 K, readily recombines with the dicarbonyl intermediates to form both the fac-Re(diimine)(CO)3Cl starting material and the mer-Re(diimine)(CO)3Cl photoproduct. Experiments over a range of temperatures (265-285 K) allow estimates of the activation enthalpy of recombination for each process of ca. 16 (±6) kJ mol(-1) (mer formation) and 23 (±4) kJ mol(-1) (fac formation) within the MOF. We have compared the photochemistry of the ReMn MOF with a related alkane-soluble Re(dnb)(CO)3Cl complex (dnb = 4,4'-dinonyl-2,2'-bipyridine). Time-resolved IR measurements clearly show that, in an alkane solution, the photoinduced dicarbonyl species again recombines with CO to both re-form the fac-isomer starting material and form the mer-isomer photoproduct. Density functional theory calculations of the possible dicarbonyl species aids the assignment of the experimental data in that the ν(CO) IR bands of the CO loss intermediate are, as expected, shifted to lower energy when the metal is bound to DMF rather than to an alkane and both solution data and calculations suggest that the ν(CO) band positions in the photoproduced dicarbonyl intermediates of ReMn are consistent with DMF binding.

aMMP-8 in correlation to caries and periodontal condition in adolescents-results of the epidemiologic LIFE child study.

PubMed

Schmidt, Jana; Guder, Ulrike; Kreuz, Markus; Löffler, Markus; Kiess, Wieland; Hirsch, Christian; Ziebolz, Dirk; Haak, Rainer

2018-01-01

The suitability of a chairside aMMP-8 test in determination of periodontal inflammation and caries in adolescents was assessed. Secondly, the influence of orthodontic treatment on aMMP-8 test result was analyzed. Within the LIFE Child study, 434 adolescents (10 to 18 years) were included. Clinical dental examinations comprised caries experience (DMF/T-Index), signs of periodontal inflammation (probing pocket depth, PPD; community periodontal index of treatment needs; CPITN) at six index teeth and oral hygiene (OH). Information about orthodontic appliances (OA) and socioeconomic status (SES) were obtained by validated questionnaires. Test's sensitivity and specificity to detect periodontal inflammation and carious lesions were evaluated. The influence of OA on the test result was analyzed (multivariate model). No associations between age, gender, SES or OH, and test outcome were found (p > 0.05). Positive test results correlated to periodontal findings (CPITN, mean PPD; p < 0.001). However, for the detection of ≥ 1 site(s) with PPD ≥ 4 mm, the test's sensitivity and specificity were found to be 61 and 69%, respectively. Multivariate analysis revealed a higher probability for a positive test result in cases of fixed OA (odds ratio 5.02, 95% confidence interval 1.90-13.19). The test had no diagnostic value considering carious lesions. The chairside aMMP-8 test does not reliably identify adolescents with periodontal inflammation. Positive test results were more frequent in case of OA. The chairside aMMP-8 test is no appropriate tool to screen children and adolescents neither for periodontal inflammation nor for carious lesions.

The impact of oral health conditions, socioeconomic status and use of specific substances on quality of life of addicted persons.

PubMed

Marques, Tais Cristina Nascimento; Sarracini, Karin Luciana Migliato; Cortellazzi, Karine Laura; Mialhe, Fábio Luiz; de Castro Meneghim, Marcelo; Pereira, Antonio Carlos; Ambrosano, Glaucia Maria Bovi

2015-03-20

The aim of this cross-sectional study was to evaluate the impact of oral health conditions, socioeconomic status and use of specific substances on quality of life of alcohol and drug addicted persons, receiving care at outpatient treatment facilities in Brazil. A random sample of 262 participants, mean age 37 years, from Psychosocial Care Centers for Alcohol and Drugs (CAPS AD) located in three cities in the state of São Paulo, Brazil, were clinically examined for caries experience (DMFT index) by a calibrated examiner. They were asked to complete a series of questionnaires, including the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), socioeconomic characteristics, and the World Health Organization Quality of Life assessment (WHOQOL), which were considered the outcome variables of the study. Associations between oral health status, socioeconomic characteristics, substance involvement with WHOQOL were investigated by means of the chi-square test and multiple logistic regression analysis with a level of significance α < 0.05. The mean DMF index of the group was 13.0. Subjects with DMFT >14 (OR = 2.25; CI 95% = 1.30-3.89); low-income (OR = 2.41; CI 95% = 1.22-4.77) and users of cocaine/crack (OR = 2.02; CI 95% = 1.15-3.59) were more likely to have poor general quality of life. This study demonstrated that the general quality of life of addicted persons was associated with caries experience, low income and cocaine/crack use.

Prevention of maternal bacterial transmission on children's dental-caries-development: 4-year results of a pilot study in a rural-child population.

PubMed

Ercan, Ertuğrul; Dülgergil, C Türksel; Yildirim, Işil; Dalli, Mehmet

2007-08-01

Dental caries with its bacterial agent is an infectious disease, and shows a vertical transmission. The control of bacterial transmission of Mutans streptococci (MS) from mother to child has been studied, and its results on their children's caries development, and on their siblings' bacterial levels, have been analysed in a field-trial (for 4 years) in rural area. In the same tribe, 8 mothers and their 11 children (test children [TC]), and then (following years) their 9 siblings (test sibling [TSb]), were followed for 4 years. The study started when the TC group had just started to erupt. Test mothers were subjected to a preventive regime. Examination of caries development as well as determination of plaque levels of MS in TC and TSb were carried out annually and at 6-month intervals. At the end of 4 years, two control groups (control children [CC] and control siblings [CSb]) resembling TC and TSb were selected from the other tribe living in the same village, and bacterial data and caries status were compared to both test groups. Microbial data demonstrated that the test children (p<0.01) and test siblings (p<0.05) had significantly low bacterial level in plaque samples. Accordingly, TC had significantly low dmf-t and -s number compared to corresponding control group (p<0.001 for dmf-t, p<0.0001 for dmf-s). The preventive regimen was applicable in rural southeastern Anatolia, where an introverted life style with a great tribal system is prevailing, any other preventive measures may have been practical or available, and babies are basically cared by mothers.

Fluometuron and pendimethalin runoff from strip and conventionally tilled cotton in the southern atlantic coastal plain.

PubMed

Potter, Thomas L; Truman, Clint C; Bosch, David D; Bednarz, Craig

2004-01-01

In the Atlantic Coastal Plain region of southern Georgia (USA), cotton (Gossypium hirsutum L.) acreage increased threefold in the past decade. To more effectively protect water quality in the region, best management practices are needed that reduce pesticide runoff from fields in cotton production. This study compared runoff of two herbicides, fluometuron [N,N-dimethyl-N'-[3-(trifluoromethyl)-phenyl]-urea] and pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitro-benzenamine], from plots in strip-tillage (ST) and conventional-tillage (CT) management near Tifton, GA. Rainfall simulations were conducted one day after preemergence herbicide applications to 0.0006-ha plots and runoff from 0.15-ha plots due to natural rainfall following preemergence pendimethalin and fluometuron and postemergence fluometuron use was monitored. Pendimethalin runoff was greater under CT than ST due to strong pendimethalin soil sorption and higher erosion and runoff under CT. The highest losses, 1.3% of applied in CT and 0.22% of applied in ST, were observed during rainfall simulations conducted 1 DAT. Fluometuron runoff from natural rainfall was substantially lower from ST than from CT plots but the trend was reversed in rainfall simulations. In all studies, fluometuron runoff was also relatively low (<1% of applied), and on plots under natural rainfall, desmethylfluometuron (DMF) represented about 50% of total fluometuron runoff. Fluometuron's relatively low runoff rate appeared linked to its rapid leaching, and high DMF detection rates in runoff support DMF inclusion in fluometuron risk assessments. Results showed that ST has the potential to reduce runoff of both herbicides, but fluometuron leaching may be a ground water quality concern.

Plant-available and water-soluble phosphorus in soils amended with separated manure solids.

PubMed

Gasser, M-O; Chantigny, M H; Angers, D A; Bittman, S; Buckley, K E; Rochette, P; Massé, D

2012-01-01

Physical, chemical, or biological treatment of animal liquid manure generally produces a dry-matter rich fraction (DMF) that contains most of the initial phosphorus (P). Our objective was to assess the solubility and plant availability of P from various DMFs as a function of soil P status. Eight different DMFs were obtained from liquid swine (LSM) and dairy cattle (LDC) manures treated by natural decantation, anaerobic digestion, chemical flocculation, composting, or mechanical separation. The DMFs were compared with mineral P fertilizer in a pot experiment with oat ( L.) grown in four soils with varied P-fixing capacities and P saturation levels. The DMFs were added at a rate of 50 mg P kg soil and incubated 14 d before seeding. Soil water-extractable P (P) at all water:soil extraction ratios (2:1, 20:1, and 200:1) was slightly higher when DMFs were derived from LDC rather than LSM. Soil P at the 2:1 ratio was lower with anaerobically digested LSM. At the 2:1 extraction ratio, DMF P was less soluble than mineral P as P saturation in soils increased. In soils with a lower P-fixing capacity, DMF P appeared less water soluble than mineral P under 20:1 and 200:1 extraction ratios. After 72 d of plant growth, DMFs produced yields comparable to mineral P fertilizer. Although the plant availability of P from DMFs was comparable to mineral P fertilizer, P from DMFs could be less vulnerable to leaching or runoff losses in soils with a high P saturation level or low P-fixing capacity. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Survismeter, 2-IN-1 for Viscosity and Surface Tension Measurement, AN Excellent Invention for Industrial Proliferation of Surface Forces in Liquids

NASA Astrophysics Data System (ADS)

Singh, Man

Viscosities (η, N s m-2) and surface tensions (γ, N m-1) of methanol, ethanol, glycerol, ethyl acetate, n-hexane, diethyl ether, chloroform, benzene, carbon tetrachloride (CCl4), tetrahydrofuran (THF), dimethylformamide (DMF), dimethylsulfoxide (DMSO), acetonitrile, and formic acid have been measured with survismeter and compared with the data obtained by Ubbehold viscometer and stalagmometer, respectively. The ±1.1 × 10-5 N s m-2 and ±1.3 × 10-6 N m-1 deviations are noted in the data, in fact literature data of surface tension and viscosity are available to 2nd and 3rd place of decimals, respectively, while the survismeter measures them to 3rd and 4th place of decimals, respectively. The survismeter is 2-in-1 for viscosity and surface tension measurements together with high accuracies several times better than those of the separately measured data. Viscosities and surface tensions of aqueous DMSO, THF, DMF, and acetonitrile from 0.01 to 0.20 mol kg-1 and mannitol from 0.005 to 0.02 mol kg-1 have been measured with survismeter with ±1.2 × 10-5 N s m-2 and ±1.3 × 10-6 N m-1 deviations, respectively. The data are used for friccohesity and dipole moment determination, the lower viscosities, surface tension, and friccohesity values are noted for mannitol as compared to DMSO, THF, DMF, and acetonitrile solutions. The weaker molecular interactions are noted for mannitol. As compared to viscometer and stalagmometer individually, it is inexpensive and minimizes 2/3rd of consumables, human efforts, and infrastructure with 10 times better accuracies.

Triphenylamine based reactive coloro/fluorimetric chemosensors: Structural isomerism and solvent dependent sensitivity and selectivity

NASA Astrophysics Data System (ADS)

Kundu, Anu; Anthony, Savarimuthu Philip

2018-01-01

Triphenyl amine based chemosensors, (2-(((2-(9H-carbazol-9-yl)phenyl)imino)methyl)-5-(diphenylamino)phenol (ortho-CPDP) and 2-(((4-(9H-carbazol-9-yl)phenyl)imino)methyl)-5-(diphenylamino)phenol (para-CPDP), showed solvent and isomerism dependent selective coloro/fluorometric sensing of multiple metal ions (Fe3 +, Al3 + and Zn2 +) with distinguishable responses. In CH3CN, ortho and para-CPDP selectively produced yellow color upon addition of Al3 + and Fe3 + that was slowly disappeared. The yellow color of ortho and para-CPDP in DMF was decolourised selectively by adding Al3 + and Fe3 +. Both ortho and para-CPDP in CH3CN showed nearly similar rate of decolourization for Fe3 + and Al3 +. However, the rate of decolourization of ortho and para-CPDP in DMF was different for Fe3 + (10 μM, 8 min) and Al3 + (5 × 10- 4 M, 40 min) ions. The limit of detection of para-CPDP for Fe3 + is 10 μM and Al3 + 500 μM. The mechanistic studies revealed the imine hydrolysis of ortho and para-CPDP in presence of Lewis acidic Fe3 + and Al3 +. The reactivity based sensing lead to high selectivity for Al3 + and Fe3 + ions. Further, para-CPDP exhibited selective fluorescence turn-on for Zn2 + in DMF (λmax = 513 nm) and detection limit of 6.0 μM. Thus, reactive chemosensors, ortho and para-CPDP, exhibited selective and distinguishable colorimetric sensing of Fe3 + and Al3 + ions and isomerism and solvent dependent fluorescence sensing of Zn2 +.

The effect of coadsorbent and solvent on the photovoltaic performance of 2,9,16,23-Tetrakis(7-coumarinoxy-4-methyl)-phthalocyaninatocopper-sensitized solar cells

NASA Astrophysics Data System (ADS)

Zhang, Fei; Wang, Shi-Rong; Li, Xiang-Gao; Xiao, Yin; Guo, Jun-Jie

2016-03-01

The synthesis, characterization and thermal properties of CuPc-Cou were reported and the effects of chenodeoxycholic acid (CHENO) as a coadsorbent and the solvent on the solar cell's performance were investigated. The ground state absorbance of CuPc-Cou showed the molar extinction coefficients as high as 2.90 × 104 dm3 mol-1 cm-1 in DMF and 2.74 × 104 dm3 mol-1 cm-1 in CH2Cl2. The thermal stability studies indicated that CuPc-Cou was stable up to 370 °C. Furthermore, HOMO and LUMO energies made it clear that CuPc-Cou can be used as a sensitizer for DSSC. Adding CHENO onto TiO2 nanoparticles not only reduced the adsorption of phthalocyanine sensitizers but also prevented the aggregation behavior, leading to different photovoltaic performance. The open circuit voltage of the solar cells with CHENO coadsorbent increased due to the enhanced electron lifetime in TiO2 nanoparticles coupled with the band edge shift of TiO2 to negative potentials. The optimal dye adsorption condition of the TiO2 electrode was found to be 3 × 10-4 M CuPc-Cou solution containing 6.0 mM CHENO in dichloromethane, which could contribute to improve the PCE by 69% as compared to the solar cell fabricated with TiO2 electrode sensitized by the CuPc-Cou in absence of CHENO and the optimal condition in DMF. It indicated that CuPc-Cou in DMF was easy to aggregate than in CH2Cl2 for the solvent effect.

Heterometal silver/copper(I) modulated thermochromism of two isostructural iodoplumbates

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

Li, Honghong; Yu, Tanlai; An, Li

2015-01-15

Two isostructrual heterometallic iodoplumbates [Y(DMF){sub 8}]{sub 2n}[Pb{sub 7}M{sub 2}I{sub 22}]{sub n} [M=Cu(1), Ag(2)] have been prepared. Chargely balanced by [Y(DMF){sub 8}]{sup 3+}, [Pb{sub 7}M{sub 2}I{sub 22}]{sub n}{sup 6n−} displays a 1D zigzag chain constructed from MI{sub 4} tetrahedron and Pb{sub 7}I{sub 24} unit similar to a fragment of commonly observed (PbI{sub 3}){sub n}{sup n−} chain. Their band gaps (Eg) can be estimated as 2.66 and 2.72 eV, revealing potential semiconducting properties. Interestingly, thermochromism exhibits different response to the temperature for two compounds, which is verified by the diffuse-reflectance UV–visible spectra and crystallographic data at different temperatures. Moreover, this phenomenon ismore » attributed to the difference of heterometal Ag and Cu(I). - Graphical abstract: Two isostructrual heterometallic iodoplumbates [Y(DMF){sub 8}]{sub 2n}[Pb{sub 7}M{sub 2}I{sub 22}]{sub n} [M=Cu(1),Ag(2)] have been prepared. [Pb{sub 7}M{sub 2}I{sub 22}]{sub n}{sup 6n−} displays a 1D zigzag chain constructed from MI{sub 4} tetrahedron and Pb{sub 7}I{sub 24} unit similar to a fragment of commonly observed (PbI{sub 3}){sub n}{sup n−} chain. Interestingly, the thermochromism for two compounds exhibits different response to the temperature, which is attributed to the difference of heterometal Ag and Cu. - Highlights: • Two isostructrual heterometallic iodoplumbates have been prepared. • Single-crystal-X-ray diffraction data were collected at different temperatures. • Spectroscopic characterization showed semiconducting and thermochromic properties. • The difference of thermochromic properties for two compounds was studied.« less

A directed matched filtering algorithm (DMF) for discriminating hydrothermal alteration zones using the ASTER remote sensing data

NASA Astrophysics Data System (ADS)

Fereydooni, H.; Mojeddifar, S.

2017-09-01

This study introduced a different procedure to implement matched filtering algorithm (MF) on the ASTER images to obtain the distribution map of alteration minerals in the northwestern part of the Kerman Cenozoic Magmatic Arc (KCMA). This region contains many areas with porphyry copper mineralization such as Meiduk, Abdar, Kader, Godekolvari, Iju, Serenu, Chahfiroozeh and Parkam. Also argillization, sericitization and propylitization are the most common types of hydrothermal alteration in the area. Matched filtering results were provided for alteration minerals with a matched filtering score, called MF image. To identify the pixels which contain only one material (endmember), an appropriate threshold value should be used to the MF image. The chosen threshold classifies a MF image into background and target pixels. This article argues that the current thresholding process (the choice of a threshold) shows misclassification for MF image. To address the issue, this paper introduced the directed matched filtering (DMF) algorithm in which a spectral signature-based filter (SSF) was used instead of the thresholding process. SSF is a user-defined rule package which contains numeral descriptions about the spectral reflectance of alteration minerals. On the other hand, the spectral bands are defined by an upper and lower limit in SSF filter for each alteration minerals. SSF was developed for chlorite, kaolinite, alunite, and muscovite minerals to map alteration zones. The validation proved that, at first: selecting a contiguous range of MF values could not identify desirable results, second: unexpectedly, considerable frequency of pure pixels was observed in the MF scores less than threshold value. Also, the comparison between DMF results and field studies showed an accuracy of 88.51%.

Study of complexation process between 4'-nitrobenzo-15-crown-5 and yttrium(III) cation in binary mixed non-aqueous solvents using conductometric method

NASA Astrophysics Data System (ADS)

Habibi, N.; Rounaghi, G. H.; Mohajeri, M.

2012-12-01

The complexation reaction of macrocyclic ligand (4'-nitrobenzo-15C5) with Y3+ cation was studied in acetonitrile-methanol (AN-MeOH), acetonitrile-ethanol (AN-EtOH), acetonitrile-dimethylformamide (AN-DMF) and ethylacetate-methanol (EtOAc-MeOH) binary mixtures at different temperatures using conductometry method. The conductivity data show that in all solvent systems, the stoichiometry of the complex formed between 4'-nitrobenzo-15C5 and Y3+ cation is 1: 1 (ML). The stability order of (4'-nitrobenzo-15C5). Y3+ complex in pure non-aqueous solvents at 25°C was found to be: EtOAc > EtOH > AN ≈ DMF > MeOH, and in the case of most compositions of the binary mixed solvents at 25°C it was: AN≈MeOH ≈ AN-EtOH > AN-DMF > EtOAc-MeOH. But the results indicate that the sequence of the stability of the complex in the binary mixed solutions changes with temperature. A non-linear behavior was observed for changes of log K f of (4'-nitrobenzo-15C5 · Y3+) complex versus the composition of the binary mixed solvents, which was explained in terms of solvent-solvent interactions and also the hetero-selective solvation of the species involved in the complexation reaction. The values of thermodynamic parameters (Δ H {c/ℴ} and Δ S {c/ℴ}) for formation of the complex were obtained from temperature dependent of the stability constant using the van't Hoff plots. The results represent that in most cases, the complex is both enthalpy and entropy stabilized and the values and also the sign of thermodynamic parameters are influenced by the nature and composition of the mixed solvents.

Theoretical insights into the stabilities, detonation performance, and electrostatic potentials of cocrystals containing α- or β-HMX and TATB, FOX-7, NTO, or DMF in various molar ratios.

PubMed

Song, Ken-Peng; Ren, Fu-de; Zhang, Shu-Hai; Shi, Wen-Jing

2016-10-01

A molecular dynamics method was employed to study the binding energies associated with the cocrystallization (at selected crystal planes) of either 1,3,5-triamino-2,4,6-trinitro-benzene (TATB), 1,1-diamino-2,2-dinitroethylene, 3-nitro-1,2,4-triazol-5-one (TATB, FOX-7, and NTO, respectively, all of which are explosives), or N,N-dimethylformamide (DMF, a nonenergetic solvent) in various molar ratios with 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane in its α and β conformations (α-HMX and β-HMX, respectively). The results showed that the cocrystals with low molar ratios (2:1, 1:1, 1:2, and 1:3) were the most stable. The binding energies of HMX/NTO and HMX/DMF were larger than those of HMX/TATB and HMX/FOX-7. According to the calculated stabilities, HMX prefers to adopt its α form in HMX/TATB and its β form in HMX/NTO, whereas the two forms coexist in HMX/FOX-7. For HMX/TATB, HMX/NTO, and α-HMX/FOX-7, increasing the proportion of the cocrystal component with the highest detonation heat (HMX in the first two cases, FOX-7 in the latter) increases the detonation heat, velocity, and pressure of the cocrystal. However, increasing the proportion of the component with the highest detonation heat in β-HMX/FOX-7 and γ-CL-20/FOX-7 increases the detonation heat of the cocrystal but decreases its detonation velocity. An investigation of the surface electrostatic potential revealed how the sensitivity changes upon cocrystal formation. Graphical Abstract Surface electrostatic potential of HMX/TATB.

Metabolism of Kaempferia parviflora polymethoxyflavones by human intestinal bacterium Bautia sp. MRG-PMF1.

PubMed

Kim, Mihyang; Kim, Nayoung; Han, Jaehong

2014-12-24

Poylmethoxyflavones (PMFs) are major bioactive flavonoids, which exhibit various biological activities, such as anticancer effects. The biotransformation of PMFs and characterization of a PMF-metabolizing human intestinal bacterium were studied herein for the first time. Hydrolysis of aryl methyl ether functional groups by human fecal samples was observed from the bioconversion of various PMFs. Activity-guided screening for PMF-metabolizing intestinal bacteria under anaerobic conditions resulted in the isolation of a strict anaerobic bacterium, which was identified as Blautia sp. MRG-PMF1. The isolated MRG-PMF1 was able to metabolize various PMFs to the corresponding demethylated flavones. The microbial conversion of bioactive 5,7-dimethoxyflavone (5,7-DMF) and 5,7,4'-trimethoxyflavone (5,7,4'-TMF) was studied in detail. 5,7-DMF and 5,7,4'-TMF were completely metabolized to 5,7-dihydroxyflavone (chrysin) and 5,7,4'-trihydroxyflavone (apigenin), respectively. From a kinetics study, the methoxy group on the flavone C-7 position was found to be preferentially hydrolyzed. 5-Methoxychrysin, the intermediate of 5,7-DMF metabolism by Blautia sp. MRG-PMF1, was isolated and characterized by nuclear magnetic resonance spectroscopy. Apigenin was produced from the sequential demethylation of 5,7,4'-TMF, via 5,4'-dimethoxy-7-hydroxyflavone and 7,4'-dihydroxy-5-methoxyflavone (thevetiaflavone). Not only demethylation activity but also deglycosylation activity was exhibited by Blautia sp. MRG-PMF1, and various flavonoids, including isoflavones, flavones, and flavanones, were found to be metabolized to the corresponding aglycones. The unprecedented PMF demethylation activity of Blautia sp. MRG-PMF1 will expand our understanding of flavonoid metabolism in the human intestine and lead to novel bioactive compounds.

Search for evidence of life in space: analysis of enantiomeric organic molecules by N,N-dimethylformamide dimethylacetal derivative dependant Gas Chromatography-Mass Spectrometry.

PubMed

Freissinet, C; Buch, A; Sternberg, R; Szopa, C; Geffroy-Rodier, C; Jelinek, C; Stambouli, M

2010-01-29

Within the context of the future space missions to Mars (MSL 2011 and Exomars 2016), which aim at searching for traces of life at the surface, the detection and quantitation of enantiomeric organic molecules is of major importance. In this work, we have developed and optimized a method to derivatize and analyze chiral organic molecules suitable for space experiments, using N,N-dimethylformamide dimethylacetal (DMF-DMA) as the derivatization agent. The temperature, duration of the derivatization reaction, and chromatographic separation parameters have been optimized to meet instrument design constraints imposed upon space experiment devices. This work demonstrates that, in addition to its intrinsic qualities, such as production of light-weight derivatives and a great resistance to drastic operating conditions, DMF-DMA facilitates simple and fast derivatization of organic compounds (three minutes at 140 degrees C in a single-step) that is suitable for an in situ analysis in space. By using DMF-DMA as the derivatization agent, we have successfully identified 19 of the 20 proteinic amino acids and been able to enantiomerically separate ten of the potential 19 (glycine being non-chiral). Additionally, we have minimized the percentage of racemized amino acid compounds produced by optimizing the conditions of the derivatization reaction itself. Quantitative linearity studies and the determination of the limit of detection show that the proposed method is also suitable for the quantitative determination of both enantiomeric forms of most of the tested amino acids, as limits of detection obtained are lower than the ppb level of organic molecules already detected in Martian meteorites. Copyright (c) 2009 Elsevier B.V. All rights reserved.

IDH1(R132H) mutation causes a less aggressive phenotype and radiosensitizes human malignant glioma cells independent of the oxygenation status.

PubMed

Kessler, Jacqueline; Güttler, Antje; Wichmann, Henri; Rot, Swetlana; Kappler, Matthias; Bache, Matthias; Vordermark, Dirk

2015-09-01

In malignant glioma the presence of the IDH1 mutation (IDH1(R132H)) is associated with better clinical outcome. However, it is unclear whether IDH1 mutation is associated with a less aggressive phenotype or directly linked to increased sensitivity to radiotherapy. We determined the influence of IDH1(R132H) mutant protein on proliferation and growth in 3D culture, migration, cell survival and radiosensitivity in vitro under normoxia (21% O2) and hypoxia (<1% O2) in a panel of human malignant glioma cell lines (U-251MG, U-343MG, LN-229) with stable overexpression of wild-type (IDH1(wt)) and mutated IDH1 (IDH1(R132H)). Overexpression of IDH1(R132H) in glioma cells resulted in slightly decreased cell proliferation, considerably reduced cell migration and caused differences in growth properties in 3D spheroid cultures. Furthermore, IDH1(R132H)-positive cells consistently demonstrated an increased radiosensitivity in human malignant glioma cells U-251MG (DMF10: 1.52, p<0.01 and 1.42, p<0.01), U-343MG (DMF10: 1.78, p<0.01 and 1.75, p<0.01) and LN-229 (DMF10: 1.41, p<0.05 and 1.68, p<0.01) under normoxia and hypoxia, respectively. Our data indicate that IDH1(R132H) mutation causes both a less aggressive biological behavior and direct radiosensitization of human malignant glioma cells. Targeting IDH1 appears to be an attractive approach in combination with radiotherapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Growing vertical ZnO nanorod arrays within graphite: efficient isolation of large size and high quality single-layer graphene.

PubMed

Ding, Ling; E, Yifeng; Fan, Louzhen; Yang, Shihe

2013-07-18

We report a unique strategy for efficiently exfoliating large size and high quality single-layer graphene directly from graphite into DMF dispersions by growing ZnO nanorod arrays between the graphene layers in graphite.

Reducing Backups by Utilizing DMF

NASA Technical Reports Server (NTRS)

Cardo, Nicholas P.; Woodrow, Thomas (Technical Monitor)

1994-01-01

Although a filesystem may be migratable, for a period of time the data blocks are on disk only. When performing system dumps, these data blocks are backed up to tape. If the data blocks are offline or dual resident, then only the inode is backed up. If all online files are made dual resident prior to performing system dumps, the dump time and the amount of resources required can be significantly reduced. The High Speed Processors group at the Numerical Aerodynamics Simulation (NAS) Facility at NASA Ames Research Center developed a tool to make all online files dual resident. The result is that a file whose data blocks are on DMF tape and still assigned to the original inode. Our 150GB filesystem used to take 8 to 12 hours to backup and used 50 to 60 tapes. Now the backup is typically under 10 tapes and completes in under 2 hours. This paper discusses this new tool and advantages gained by using it.

Polar Aprotic Modifiers for Chromatographic Separation and Back-Exchange Reduction for Protein Hydrogen/Deuterium Exchange Monitored by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

NASA Astrophysics Data System (ADS)

Valeja, Santosh G.; Emmett, Mark R.; Marshall, Alan G.

2012-04-01

Hydrogen/deuterium exchange monitored by mass spectrometry is an important non-perturbing tool to study protein structure and protein-protein interactions. However, water in the reversed-phase liquid chromatography mobile phase leads to back-exchange of D for H during chromatographic separation of proteolytic peptides following H/D exchange, resulting in incorrect identification of fast-exchanging hydrogens as unexchanged hydrogens. Previously, fast high-performance liquid chromatography (HPLC) and supercritical fluid chromatography have been shown to decrease back-exchange. Here, we show that replacement of up to 40% of the water in the LC mobile phase by the modifiers, dimethylformamide (DMF) and N-methylpyrrolidone (NMP) (i.e., polar organic modifiers that lack rapid exchanging hydrogens), significantly reduces back-exchange. On-line LC micro-ESI FT-ICR MS resolves overlapped proteolytic peptide isotopic distributions, allowing for quantitative determination of the extent of back-exchange. The DMF modified solvent composition also improves chromatographic separation while reducing back-exchange relative to conventional solvent.

Degradation of Highly Alloyed Metal Halide Perovskite Precursor Inks: Mechanism and Storage Solutions

DOE PAGES

Dou, Benjia; Wheeler, Lance M.; Christians, Jeffrey A.; ...

2018-03-14

Whereas the promise of metal halide perovskite (MHP) photovoltaics (PV) is that they can combine high efficiency with solution-processability, the chemistry occurring in precursor inks is largely unexplored. Herein, we investigate the degradation of MHP solutions based on the most widely used solvents, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). For the MHP inks studied, which contain formamidinium (FA+), methylammonium (MA+), cesium (Cs+), lead (Pb2+), bromide (Br-), and iodide (I-), dramatic compositional changes are observed following storage of the inks in nitrogen in the dark. We show that hydrolysis of DMF in the precursor solution forms dimethylammonium formate, which subsequently incorporatesmore » into the MHP film to compromise the ability of Cs+ and MA+ to stabilize FA+-based MHP. The changes in solution chemistry lead to a modification of the perovskite film stoichiometry, band gap, and structure. The solid precursor salts are stable when ball-milled into a powder, allowing for the storage of large quantities of stoichiometric precursor materials.« less

Synthesis, characterization and anticancer activity of a Cd(II) complex with in situ formation of (E)-1-(5-chloro-2-hydroxy-benzylideneamino)-pyrrolidin-2-one ligand

NASA Astrophysics Data System (ADS)

Huang, Qiu-Ying; Zheng, Ze-Bao; Diao, Yun-Peng

2015-05-01

A new complex of Cd(II) with (E)-1-(5-chloro-2-hydroxybenzylideneamino)-pyrrolidin-2-one [Cd(L)2ṡ2DMF] was synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. Where the HL ligand is formed in situ by the intramolecular nucleophilic substitution of (E)-N‧-(5-chloro-2-hydroxybenzyli-dene)-4-(quinolin-8-yloxy)butanehydrazide (H2L‧). The cadmium(II) ion is hexacoordinated by two tridentate L- ligands and giving a distorted octahedral coordination geometry. A cytotoxicity of [Cd(L)2ṡ2DMF] against liver (SMMC-7721) and cervical (HeLa) cancer cells have been studied. The results revealed that this cadmium(II) complex exhibited an effective and selective anticancer activity against HeLa over SMMC-7721 cell line with IC50 of 1.54 ± 0.25 and 31.02 ± 3.76 μmol/dm-3.

Electron-transfer quenching vs. exciplex-mediated quenching of the low-lying excited states in phthalocyanines

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

Prasad, D.R.; Ferraudi, G.

1983-05-25

Oxidative electron-transfer quenching of the lowest ligand-centered /sup 3/..pi pi..* of ruthenium (RU) phthalocyanines (pc)L/sub 2/, L = dimethylformamide (dmf) or pyridine (py), by a series of nitroaromatic compounds, viologen salts, and metal complexes has been investigated by laser and conventional flash photolysis. The quenching rate constants, treated according to Marcus-Hush and Rehm-Weller equations, gave self-exchange rate constants, k/sub exch/ approx. 10/sup 7/ M/sup -1/ s/sup -1/, for the electron exchange between the /sup 3/..pi pi..* and the ruthenium(II) ligand radical. The excited states of a number of phthalocyanines, e.g. Ru(pc)(dimethyl sulfoxide(Me/sub 2/SO)/sub 2/), Ru(pc)(dmf)CO, Ru(pc)(py)CO, and Rh(pc)(methanol(CH/sub 3/OH)chloride), undergomore » quenching mediated by exciplex formation. The formation of exciplexes is discussed in terms of the related exciplexes of the porphyrins.« less

Selective Hydrodeoxygenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran over Heterogeneous Iron Catalysts.

PubMed

Li, Jiang; Liu, Jun-Ling; Liu, He-Yang; Xu, Guang-Yue; Zhang, Jun-Jie; Liu, Jia-Xing; Zhou, Guang-Lin; Li, Qin; Xu, Zhi-Hao; Fu, Yao

2017-04-10

This work provided the first example of selective hydrodeoxygenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) over heterogeneous Fe catalysts. A catalyst prepared by the pyrolysis of an Fe-phenanthroline complex on activated carbon at 800 °C was demonstrated to be the most active heterogeneous Fe catalyst. Under the optimal reaction conditions, complete conversion of HMF was achieved with 86.2 % selectivity to DMF. The reaction pathway was investigated thoroughly, and the hydrogenation of the C=O bond in HMF was demonstrated to be the rate-determining step during the hydrodeoxygenation, which could be accelerated greatly by using alcohol solvents as additional H-donors. The excellent stability of the Fe catalyst, which was probably a result of the well-preserved active species and the pore structure of the Fe catalyst in the presence of H 2 , was demonstrated in batch and continuous flow fixed-bed reactors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectra, energy levels, and energy transition of lanthanide complexes with cinnamic acid and its derivatives

NASA Astrophysics Data System (ADS)

Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju

2016-04-01

High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L = cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF = N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu3 + in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu3 + ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of 5D0 and triplet state contracts.

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

Moorhouse, Saul J.; Wu, Yue; O’Hare, Dermot, E-mail: dermot.ohare@chem.ox.ac.uk

A newly developed in situ monochromatic high-energy X-ray diffraction setup was used to investigate the synthesis of MOFs using cation-impregnated polymer resin beads as a ion source. The Co–NDC–DMF (NDC=2,6-naphthalenedicarboxylate; DMF=dimethylformamide) system was investigated, a system which is known to produce at least three distinct frameworks. It was found that the resin-assisted synthesis results in the preferential formation of a topology previously impossible to synthesise in bulk, while the comparable nitrate-salt synthesis appeared to form an alternative phases. It was also found that the resin-assisted synthesis is highly diffusion-controlled. - Graphical abstract: In situ monochromatic high-energy X-ray diffraction study ofmore » a MOF synthesis. - Highlights: • Resin-assisted solvothermal MOF synthesis was studied using in situ diffraction. • Full kinetics of reaction can be obtained from in situ data. • Kinetics show that this resin-assisted synthesis is diffusion controlled. • Resin-assisted synthesis enables the production of an alternative bulk phase.« less

Copper Phthalocyanine Functionalized Single-Walled Carbon Nanotubes: Thin Films for Optical Detection.

PubMed

Banimuslem, Hikmat; Hassan, Aseel; Basova, Tamara; Durmuş, Mahmut; Tuncel, Sinem; Esenpinar, Aliye Asli; Gürek, Ayşe Gül; Ahsen, Vefa

2015-03-01

Thin films of non-covalently hybridized single-walled carbon nanotubes (SWCNT) and tetra-substituted copper phthalocyanine (CuPcR4) molecules have been produced from their solutions in dimethylformamide (DMF). FTIR spectra revealed the 7π-7π interaction between SWCNTs and CuPcR4 molecules. DC conductivity of films of acid-treated SWCNT/CuPcR4 hybrid has increased by more than three orders of.magnitude in comparison with conductivity of CuPcR4 films. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements have shown that films obtained from the acid-treated SWCNTs/CuPcR4 hybrids demonstrated more homogenous surface which is ascribed to the highly improved solubility of the hybrid powder in DMF Using total internal reflection ellipsometry spectroscopy (TIRE), thin films of the new hybrid have been examined as an optical sensing membrane for the detection of benzo[a]pyrene in water to demonstrate the sensing properties of the hybrid.

A novel Zn-based heterocycle metal-organic framework for high C2H2/C2H4, CO2/CH4 and CO2/N2 separations

NASA Astrophysics Data System (ADS)

Zhang, Ling; Jiang, Ke; Yang, Yu; Cui, Yuanjing; Chen, Banglin; Qian, Guodong

2017-11-01

Efficient separation of the small gas molecules especially the hydrocarbons is essential to social economy. The microporous metal-organic frameworks (MOFs) are taking precedence in this respect by virtue of their irreplaceable advantages. Herein, the new organic linker 5-(5-carboxypyridin-3-yl)isophthalic acid simplified as H3L-N has been excavated to construct successfully the novel Zn-based heterocycle metal-organic framework ZnL·(DMF)1.5·(H2O)6.0 (ZJU-197, ZJU = Zhejiang University, DMF = N,N-dimethylformamide). ZJU-197 has been structurally characterized and explored in details for gas separation. It is commendable that the activated ZJU-197a has exhibited excellent C2H2/C2H4, CO2/CH4 and CO2/N2 separations simultaneously with IAST selectivity of 137.8, 53.0 and 514.1 respectively at ambient conditions.

Taking Advantage of Reduced Droplet-surface Interaction to Optimize Transport of Bioanalytes in Digital Microfluidics

PubMed Central

Freire, Sergio L. S.; Thorne, Nathaniel; Wutkowski, Michael; Dao, Selina

2014-01-01

Digital microfluidics (DMF), a technique for manipulation of droplets, is a promising alternative for the development of “lab-on-a-chip” platforms. Often, droplet motion relies on the wetting of a surface, directly associated with the application of an electric field; surface interactions, however, make motion dependent on droplet contents, limiting the breadth of applications of the technique. Some alternatives have been presented to minimize this dependence. However, they rely on the addition of extra chemical species to the droplet or its surroundings, which could potentially interact with droplet moieties. Addressing this challenge, our group recently developed Field-DW devices to allow the transport of cells and proteins in DMF, without extra additives. Here, the protocol for device fabrication and operation is provided, including the electronic interface for motion control. We also continue the studies with the devices, showing that multicellular, relatively large, model organisms can also be transported, arguably unaffected by the electric fields required for device operation. PMID:25407533

Eu(III) and Tb(III) complexes with the nonsteroidal anti-inflammatory drug carprofen: synthesis, crystal structure, and photophysical properties.

PubMed

Zhou, Xianju; Zhao, Xiaoqi; Wang, Yongjie; Wu, Bing; Shen, Jun; Li, Li; Li, Qingxu

2014-12-01

Two new lanthanide complexes with general formula [Ln2(carprofen)6(DMF)2] (Ln = Eu (1), Tb (2), DMF = N,N-dimethylformamide, carprofen = 6-chloro-α-methylcarbazole-2-acetic acid) have been synthesized by a hydrothermal method. Complex 1 was characterized by single-crystal X-ray diffraction (XRD), and it was found to crystallize in the monoclinic space group C2/c. The coordination of the ligand to the lanthanide ion has been investigated by Fourier-transform infrared (FTIR) spectra and ultraviolet-visible (UV-vis) absorption spectra. Complex 1 emits red light, but the antenna effect of the ligand is not effective, whereas complex 2 presents intense green emission with effective energy transfer from the ligand. The different performance of the two complexes is related to the energy matching between the excited states of the lanthanide ion and the triplet state of the ligand. The intramolecular energy transfer mechanisms are also discussed.

A thermodynamic study of complexation process between N, N'-dipyridoxylidene(1,4-butanediamine) and Cd2+ in some binary mixed solvents using conductometry

NASA Astrophysics Data System (ADS)

Ebrahimpoor, Sonia; Khoshnood, Razieh Sanavi; Beyramabadi, S. Ali

2016-12-01

Complexation of the Cd2+ ion with N, N'-dipyridoxylidene(1,4-butanediamine) Schiff base was studied in pure solvents including acetonitrile (AN), ethanol (EtOH), methanol (MeOH), tetrahydrofuran (THF), dimethylformamide (DMF), water (H2O), and various binary solvent mixtures of acetonitrile-ethanol (AN-EtOH), acetonitrile-methanol (AN-MeOH), acetonitrile-tetrahydrofuran (AN-THF), acetonitrile-dimethylformamide (AN-DMF), and acetonitrile-water (AN-H2O) systems at different temperatures using the conductometric method. The conductance data show that the stoichiometry of complex is 1: 1 [ML] in all solvent systems. A non-linear behavior was observed for changes of log K f of [Cd( N, N'-dipyridoxylidene(1,4-butanediamine)] complex versus the composition of the binary mixed solvents, which was explained in terms of solvent-solvent interactions. The results show that the thermodynamics of complexation reaction is affected by the nature and composition of the mixed solvents.

Degradation of Highly Alloyed Metal Halide Perovskite Precursor Inks: Mechanism and Storage Solutions

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

Dou, Benjia; Wheeler, Lance M.; Christians, Jeffrey A.

Whereas the promise of metal halide perovskite (MHP) photovoltaics (PV) is that they can combine high efficiency with solution-processability, the chemistry occurring in precursor inks is largely unexplored. Herein, we investigate the degradation of MHP solutions based on the most widely used solvents, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). For the MHP inks studied, which contain formamidinium (FA+), methylammonium (MA+), cesium (Cs+), lead (Pb2+), bromide (Br-), and iodide (I-), dramatic compositional changes are observed following storage of the inks in nitrogen in the dark. We show that hydrolysis of DMF in the precursor solution forms dimethylammonium formate, which subsequently incorporatesmore » into the MHP film to compromise the ability of Cs+ and MA+ to stabilize FA+-based MHP. The changes in solution chemistry lead to a modification of the perovskite film stoichiometry, band gap, and structure. The solid precursor salts are stable when ball-milled into a powder, allowing for the storage of large quantities of stoichiometric precursor materials.« less

De-agglomeration and homogenisation of nanoparticles in coal tar pitch-based carbon materials

NASA Astrophysics Data System (ADS)

Gubernat, Maciej; Tomala, Janusz; Frohs, Wilhelm; Fraczek-Szczypta, Aneta; Blazewicz, Stanislaw

2016-03-01

The aim of the work was to characterise coal tar pitch (CTP) modified with selected nanoparticles as a binder precursor for the manufacture of synthetic carbon materials. Different factors influencing the preliminary preparative steps in the preparation of homogenous nanoparticle/CTP composition were studied. Graphene flakes, carbon black and nano-sized silicon carbide were used to modify CTP. Prior to introducing them into liquid CTP, nanoparticles were subjected to sonication. Various dispersants were used to prepare the suspensions, i.e. water, ethanol, dimethylformamide (DMF) and N-methylpyrrolidone (NMP).The results showed that proper dispersant selection is one of the most important factors influencing the de-agglomeration process of nanoparticles. DMF and NMP were found to be effective dispersants for the preparation of homogenous nanoparticle-containing suspensions. The presence of SiC and carbon black nanoparticles in the liquid pitch during heat treatment up to 2000 °C leads to the inhibition of crystallite growth in carbon residue.

Syntheses, structures and properties of metal-carboxylate chain-based coordination polymers (CPs) with 1,1‧:4‧,1″-terphenyl-2‧,4,4″,5‧-tetracarboxylate

NASA Astrophysics Data System (ADS)

Zhou, Xinhui; Song, Lin; Li, Liang; Yang, Tao

2016-09-01

Two coordination polymers (CPs) {[Mg2L(μ2-H2O) (μ2-DMA)]·DMA}n (1), and [Ag4L(DMF)2]n (2) (H4L = 1,1‧:4‧,1″-terphenyl-2‧,4,4″,5‧-tetracarboxylic acid, DMA = N,N-dimethylacetamine, DMF = N,N-dimethylformamide) have been synthesized and structurally characterized. In 1 and 2, there exist a series of parallel aligned Msbnd Osbnd C chains, which are linked along two directions by para-terphenyl moieties of L4- ligands to lead to the metal-carboxylate chain-based three-dimensional frameworks. The photoluminescence properties of the compounds 1 and 2 have also been investigated. 1 displays blue-violet light emission with the emission maximum at 380 nm. 2 exhibits a broad emission peak from 300 to 800 nm with an emission maximum at 484 nm and some of the shoulder peaks.

Polarized Neutron Diffraction as a Tool for Mapping Molecular Magnetic Anisotropy: Local Susceptibility Tensors in Co(II) Complexes.

PubMed

Ridier, Karl; Gillon, Béatrice; Gukasov, Arsen; Chaboussant, Grégory; Cousson, Alain; Luneau, Dominique; Borta, Ana; Jacquot, Jean-François; Checa, Ruben; Chiba, Yukako; Sakiyama, Hiroshi; Mikuriya, Masahiro

2016-01-11

Polarized neutron diffraction (PND) experiments were carried out at low temperature to characterize with high precision the local magnetic anisotropy in two paramagnetic high-spin cobalt(II) complexes, namely [Co(II) (dmf)6 ](BPh4 )2 (1) and [Co(II) 2 (sym-hmp)2 ](BPh4 )2 (2), in which dmf=N,N-dimethylformamide; sym-hmp=2,6-bis[(2-hydroxyethyl)methylaminomethyl]-4-methylphenolate, and BPh4 (-) =tetraphenylborate. This allowed a unique and direct determination of the local magnetic susceptibility tensor on each individual Co(II) site. In compound 1, this approach reveals the correlation between the single-ion easy magnetization direction and a trigonal elongation axis of the Co(II) coordination octahedron. In exchange-coupled dimer 2, the determination of the individual Co(II) magnetic susceptibility tensors provides a clear outlook of how the local magnetic properties on both Co(II) sites deviate from the single-ion behavior because of antiferromagnetic exchange coupling. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

N,N-dimethylbiguanide complexes displaying low cytotoxicity as potential large spectrum antimicrobial agents.

PubMed

Olar, Rodica; Badea, Mihaela; Marinescu, Dana; Chifiriuc, Mariana-Carmen; Bleotu, Coralia; Grecu, Maria Nicoleta; Iorgulescu, Emilia-Elena; Lazar, Veronica

2010-07-01

The new complexes M(DMBG)(2)(ClO(4))(2) (M:Mn, Ni, Cu and Zn; DMBG: N,N-dimethylbiguanide) have been synthesized and characterized by IR, EPR, (1)H NMR, (13)C NMR as well as electronic spectroscopy data. Complex [Ni(DMBG)(2)](ClO(4))(2).2DMF (DMF: N,N-dimethylformamide) crystallizes in the monoclinic P2(1)/c space group while [Cu(DMBG)(2)](ClO(4))(2) adopt monoclinic P21/c space group as X-ray single crystal data indicate. The redox behavior of complexes was investigated by cyclic voltammetry. The metal-free N,N-dimethylbiguanide and complexes exhibit specific anti-infective properties as demonstrated the low MIC values, a large antimicrobial spectrum and also inhibit the ability of Pseudomonas aeruginosa and Staphylococcus aureus strains to colonize the inert surfaces. The complexes exhibit also a low cytotoxicity levels on HeLa cells. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Band gaps and photocurrent responses of two novel alkaline earth metal(II) complexes based on 4,5-di(4‧-carboxylphenyl)benzene

NASA Astrophysics Data System (ADS)

Meng, Jiang Ping; Yan, Zhi Shuo; Long, Ji Ying; Gong, Yun; Lin, Jian Hua

2017-01-01

By using a rigid dicarboxylate ligand, 4,5-di(4‧-carboxylphenyl)benzene (H2L), two complexes formulated as SrL(DMF)(H2O)·(CH3CN) (DMF=N,N‧-dimethylformamide) (1) and BaL(H2O)2 (2) were solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1 and 2 display two-dimensional (2D) layer structures. The two complexes exhibit different electrochemical and photoelectrochemical properties. Their thermal stabilities, cyclic voltammograms, UV-vis absorption and diffuse reflectance spectra and photoluminescence properties have been investigated. The band structures, the total density of states (TDOS) and partial density of states (PDOS) of the two complexes were calculated by CASTEP program. Complex 2 exhibits much higher photocurrent density than complex 1. The Mott-Schottky plots reveal that complexes 1 and 2 both are p-type semiconductors, which are in agreement with their band structure calculations.

Dielectric anomaly and relaxation natures in a Zn-Cr pillar−layered metal−organic framework with cages and channels

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

Xue, Chen; Yao, Zhi-Yuan; Liu, Shao-Xian

A bimetallic metal–organic framework (MOF) with the formula [Zn{sub 3}btc{sub 2}(Cr{sub 3}O(isonic){sub 6}(H{sub 2}O){sub 2}(OH))]·(DMF){sub 15.5}(H{sub 2}O){sub 8} (H{sub 3}btc=1,3,5-benzenetricarboxylic acid; isonic=isonicotinicate) shows a pillar-layered structure. The monolayer consists of hexagon-like rings formed by the [Zn(isonic){sub 2}(btc){sub 2}] tetrahedral and the consecutive monolayers are pillared by trigonal–prismatic clusters of [Cr{sub 3}O(isonic){sub 6}(H{sub 2}O){sub 2}(OH)]through the remaining binding sites of the Zn{sup 2+} ions. DMF and water molecules are confined in the cages and channels. TGA indicates that the lattice DMF and water molecules begin to be released at temperatures above 363 K. Dielectric measurements were carried out in the rangemore » of 173–363 K and 1–10{sup 7} Hz for three successive thermal cycles. The dielectric spectroscopy obtained in the first thermal cycle was different from that observed in the next two thermal cycles, while the dielectric spectra in the last two thermal cycles were almost identical. The dielectric nature of this MOF is discussed in detail for each thermal cycle. Since MOFs are unique host–guest systems in which the structure of the host framework is designable and the guests are exchangeable, it is no doubt those MOFs are materials with a variety of dielectric natures. This study gives a fresh impetus to achieve MOFs–based dielectric materials. - Graphical abstract: The bimetallic MOF [Zn{sub 3}btc{sub 2}(Cr{sub 3}O(isonic){sub 6}(H{sub 2}O){sub 2}(OH))]·(DMF){sub 15.5}(H{sub 2}O){sub 8}1, shows a pillar-layered open-framework structure. The dielectric spectra of 1 are almost identical in the last two thermal cycles, whereas significantly different from that observed in the first thermal cycle. The novel dielectric anomaly associated with a stacked structure transformation of the disordered guests. - Highlights: • A bimetallic metal-organic framework shows a pillar-layered structure. • The MOF displays novel dielectric anomaly and relaxation behaviors. • The dielectric anomaly arises from the stacking structure transformation of guests. • The dielectric relaxation is related to the dipole dynamics of guests.« less

Teaching evidence-based practice (EBP) to speech-language therapy students: are students competent and confident EBP users?

PubMed

Spek, B; Wieringa-de Waard, M; Lucas, C; van Dijk, N

2013-01-01

The importance and value of the principles of evidence-based practice (EBP) in the decision-making process is recognized by speech-language therapists (SLTs) worldwide and as a result curricula for speech-language therapy students incorporated EBP principles. However, the willingness actually to use EBP principles in their future profession not only depends on EBP knowledge and skills, but also on self-efficacy and task value students perceive towards EBP. To investigate the relation between EBP knowledge and skills, and EBP self-efficacy and task value in different year groups of Dutch SLT students. Students from three year groups filled in a tool that measured EBP knowledge and skills: the Dutch Modified Fresno (DMF). EBP self-efficacy and task value were assessed by using a 20-item questionnaire. Both tools were validated for this population. Mean scores for the three year groups were calculated and tested for group differences using a one-way analysis of variance (ANOVA) with a post-hoc Games-Howell procedure. With a multiple linear regression technique it was assessed whether EBP self-efficacy and task value predict learning achievement scores on the DMF. Other possible predictors included in the model were: level of prior education, standard of English, having had mathematics in prior education and the SLT study year. A total of 149 students filled in both measurement tools. Mean scores on EBP knowledge and skills were significantly different for the three year groups, with students who were further along their studies scoring higher on the DMF. Mean scores on the EBP self-efficacy and task value questionnaire were the same for the three year groups: all students valued EBP positive but self-efficacy was low in all groups. Of the possible predictors, only the year in which students study and EBP self-efficacy were significant predictors for learning achievements in EBP. Despite a significant increase in EBP knowledge and skills over the years as assessed by the DMF, the integrated EBP curriculum did not raise levels of EBP self-efficacy and task value. This lack of feeling competent might have an impact on students' willingness actually to use EBP. In curricula, therefore, there should be a focus on how to raise EBP self-efficacy in SLT students. This goes even beyond the educational department because a professional culture in which professionals are competent and confident EBP users would have a positive effect on EBP self-efficacy in students. © 2013 Royal College of Speech and Language Therapists.

Can solvent induced surface modifications applied to screen-printed platforms enhance their electroanalytical performance?

PubMed

Blanco, Elias; Foster, Christopher W; Cumba, Loanda R; do Carmo, Devaney R; Banks, Craig E

2016-04-25

In this paper the effect of solvent induced chemical surface enhancements upon graphitic screen-printed electrodes (SPEs) is explored. Previous literature has indicated that treating the working electrode of a SPE with the solvent N,N-dimethylformamide (DMF) offers improvements within the electroanalytical response, resulting in a 57-fold increment in the electrode surface area compared to their unmodified counterparts. The protocol involves two steps: (i) the SPE is placed into DMF for a selected time, and (ii) it is cured in an oven at a selected time and temperature. Beneficial electroanalytical outputs are reported to be due to the increased surface area attributed to the binder within the bulk surface of the SPEs dissolving out during the immersion step (step i). We revisit this exciting concept and explore these solvent induced chemical surface enhancements using edge- and basal-plane like SPEs and a new bespoke SPE, utilising the solvent DMF and explore, in detail, the parameters utilised in steps (i) and (ii). The electrochemical performance following steps (i) and (ii) is evaluated using the outer-sphere redox probe hexaammineruthenium(iii) chloride/0.1 M KCl, where it is found that the largest improvement is obtained using DMF with an immersion time of 10 minutes and a curing time of 30 minutes at 100 °C. Solvent induced chemical surface enhancement upon the electrochemical performance of SPEs is also benchmarked in terms of their electroanalytical sensing of NADH (dihydronicotinamide adenine dinucleotide reduced form) and capsaicin both of which are compared to their unmodified SPE counterparts. In both cases, it is apparent that a marginal improvement in the electroanalytical sensitivity (i.e. gradient of calibration plots) of 1.08-fold and 1.38-fold are found respectively. Returning to the original exciting concept, interestingly it was found that when a poor experimental technique was employed, only then significant increases within the working electrode area are evident. In this case, the insulating layer that defines the working electrode surface, which was not protected from the solvent (step (i)) creates cracks within the insulating layer exposing the underlying carbon connections and thus increasing the electrode area by an unknown quantity. We infer that the origin of the response reported within the literature, where an extreme increase in the electrochemical surface area (57-fold) was reported, is unlikely to be solely due to the binder dissolving but rather poor experimental control over step (i).

Substrate Induced Ordering of Molecular Absorbates on Au(111)

DTIC Science & Technology

1992-02-27

the right in Fig.1), crossing, apparently unperturbed, monoatomic steps (not shown here). In addition, line pairs are organized in domains, separated...following immersion of a gold -electrode in a DMF solution containing I(x=5) and after rinsing with acetone; and, 4) a detailed STM investigation of the

77 FR 6571 - Information Collection Request to Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... Office of Management and Budget AGENCY: Coast Guard, DHS. ACTION: Sixty-day notice requesting comments... Information Collection Request (ICR) to the Office of Management and Budget (OMB), Office of Information and... Management Facility (DMF) at the U.S. Department of Transportation (DOT). To avoid duplicate submissions...

76 FR 52336 - Information Collection Requests to Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-22

...-0094 and 1625- 0096] Information Collection Requests to Office of Management and Budget AGENCY: Coast... Office of Management and Budget (OMB), Office of Information and Regulatory Affairs (OIRA), requesting... docket number [USCG-2011-0737] to the Docket Management Facility (DMF) at the U.S. Department of...

Metal-organic frameworks as functional, porous materials

NASA Astrophysics Data System (ADS)

Rood, Jeffrey A.

The research presented in this thesis investigates the use of metal carboxylates as permanently porous materials called metal-organic frameworks (MOFs). The project has focused on three broad areas of study, each which strives to develop a further understanding of this class of materials. The first topic is concerned with the synthesis and structural characterization of MOFs. Our group and others have found that the reaction of metal salts with carboxylic acids in polar solvents at elevated temperatures often leads the formation of crystalline MOF materials that can be examined by single crystal X-ray diffraction. Specifically, Chapter 2 reports on some of the first examples of magnesium MOFs, constructed from formate or aryldicarboxylate ligands. The magnesium formate MOF, [Mg3(O2CH) 6] was found to be a permanently porous 3-D material capable of selective uptake and exchange of small molecules. Once the synthesis and structures of some of these materials was known, their physical properties were studied. The magnesium formate MOF, [Mg 3(O2CH)6], was found to be permanently porous and able to reversibly adsorb both N2 and H2 gas. Furthermore, the material was also capable of taking up a variety of organic molecules to form new inclusion compounds that were characterized by XRD studies. Size exclusion was shown for cyclohexane and larger molecules. Chapters 3, 5, and 6 attempt to build off of the synthetic findings reported in Chapter 2. Specifically, the ability of these materials to take up guest molecules is expanded by the attempted synthesis of porous, homochiral MOFs using enantiopure carboxylic acids in the synthesis. It was found that under the appropriate synthetic conditions, both L-tartaric acid and (+)-camphoric acid were robust linkers for the formation of homochiral MOFs. Of the compounds synthesized, the most interesting were the set of compounds, [Zn2(Cam) 2(bipy)⊃3DMF] and [Zn2(Cam)2(apyr)⊃2DMF]. These compounds formed isoreticular cubic networks in which the pore size was dependent on the size of the linker molecule (bipy or apyr). Additonally, the compounds [Zn2(Cam)2(bipy)⊃3DMF] and [Zn2(Cam)2(apyr)⊃2DMF] were found to be capable of guest exchange. Due to their chiral nature, these materials were screened for the enanatioselective separation of racemic alcohols. No selectivity was seen with either MOF, likely owing to factors such as large pore size and disorder in the chiral camphorate ligand. [Zn2(Cam)2(bipy)⊃3DMF] contained large voids and preliminary studies showed that free-radical polymerization of methylmethacrylate could take place within the channels of the material. The amino group of the apyr ligand in [Zn2(Cam)2(apyr)⊃2DMF] was able to be functionaled with acetaldehyde by treatment of the porous MOF with the bulk organic reagent. A further area of study detailed in this work deals with a central question in MOF chemistry, concerning the assembly process of these extended materials from solution. Chapter 3 reveals that the trimeric species Mg2(HCam) 3+, the SBU for the formation of the MOF [Mg2(Hcam) 3˙3H2O]˙NO3˙MeCN, can be identified using ESI-MS on the the reaction solution prior to crystallization. Further studies showed that the addition of chelating additives led to new solid-state structures and new ions in the mass spectrum, indicating that the Mg 2(HCam)3+ ion is likely present in solution prior to MOF formation. Chapter 4 discusses extension of these ESI-MS studies on various other MOF and organometallic systems. Finally, Chapter 7 discusses the synthesis and structures of magnesium imides. These compounds were originally investigated for use as SBUs in network synthesis. This strategy proved to be unsuccessful, as the compounds form molecular clusters in the solid state. The coordination chemistry and computational studies regarding the adopted aggregation state is detailed.

Oral health follow-up studies in the 1993 Pelotas (Brazil) birth cohort study: methodology and principal results

PubMed Central

Peres, Marco A.; Barros, Aluísio Jardim; Peres, Karen Glazer; Araújo, Cora Luiza; Menezes, Ana M. B.; Hallal, Pedro C.; Victora, Cesar G.

2013-01-01

The aim of this study was to describe oral health follow-up studies nested in a birth cohort. A population-based birth cohort was launched in 1993 in Pelotas, Rio Grande do Sul State, Brazil. Two oral health follow-up studies were conducted at six (n = 359) and 12 (n = 339) years of age. A high response rate was observed at 12 years of age; 94.4% of the children examined at six years of age were restudied in 2005. The mean DMF-T index at age 12 was 1.2 (SD = 1.6) for the entire sample, ranging from 0.6 (SD = 1.1) for children that were caries-free at age six, 1.3 (SD = 1.5) for those with 1-3 carious teeth at six years, and 1.8 (SD = 1.8) for those with 4-19 carious teeth at six years (p < 0.01). The number of individuals with severe malocclusions at 12 years was proportional to the number of malocclusions at six years. Oral health problems in early adolescence were more prevalent in individuals with dental problems at six years of age. PMID:20963297

Investigating a Chemoselective Grignard Reaction in an Undergraduate Discovery Lab to Predict Reactivity and Final Products

ERIC Educational Resources Information Center

Maher, Michael J.; Hayes, Colin O.; Vaccaro, Francesca A.; Flynn, Cailyn B.; Thedford, R. Paxton; Stephenson, Clifton J.

2016-01-01

A discovery-based Grignard experiment that emphasizes several important concepts in organic chemistry is reported. The Grignard reagent from 1- bromo-4-chlorobenzene was prepared and reacted with dimethylformamide (DMF) to synthesize 4-chlorobenzaldehyde. Students were tasked with predicting halogen reactivity in the formation of the Grignard…

Beyond a Terabyte File System

NASA Technical Reports Server (NTRS)

Powers, Alan K.

1994-01-01

The Numerical Aerodynamics Simulation Facility's (NAS) CRAY C916/1024 accesses a "virtual" on-line file system, which is expanding beyond a terabyte of information. This paper will present some options to fine tuning Data Migration Facility (DMF) to stretch the online disk capacity and explore the transitions to newer devices (STK 4490, ER90, RAID).

76 FR 52338 - Information Collection Request to Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-22

... Office of Management and Budget AGENCY: Coast Guard, DHS. ACTION: Sixty-day notice requesting comments... Information Collection Request (ICR) to the Office of Management and Budget (OMB), Office of Information and... Coast Guard docket number [USCG-2011-0750] to the Docket Management Facility (DMF) at the U.S...

75 FR 10297 - Information Collection Request to Office of Management and Budget; OMB Control Numbers: 1625-0056

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

... Office of Management and Budget; OMB Control Numbers: 1625-0056 AGENCY: Coast Guard, DHS. ACTION: Sixty... of Management and Budget (OMB) requesting an extension of its approval for the following collection... . (2) Mail: Docket Management Facility (DMF) (M-30), U.S. Department of Transportation (DOT), West...

Interviews of Children in a Portuguese Special Judicial Procedure.

PubMed

Peixoto, Carlos Eduardo; Fernandes, Raquel Veludo; Almeida, Telma Sousa; Silva, Júlia Marina; La Rooy, David; Ribeiro, Catarina; Magalhães, Teresa; Lamb, Michael E

2017-05-01

Since 2007, alleged victims of child sexual abuse in Portugal have provided evidence in a mandatory "Declarações para Memória Futura" (DMF; English transl. 'Statement for future use') proceeding. In order to protect children from having to testify in court, interviews conducted at the DMF can be used later as trial evidence because the hearings are conducted by judges. The present study examined 137 interviews with 3- to 17-year-olds conducted in several Portuguese criminal courts. Detailed examination of interview transcripts showed that 69% of all questions asked were option-posing questions, 16% were directive questions, 11% were suggestive questions, and only 3% were open-ended prompts. The vast majority of details provided by children were thus obtained using the risky recognition-based prompts (i.e., option posing and suggestive questions) associated with the risks of contaminating and limiting children's informativeness, both potential threats to the credibility of their testimony. There is an urgent need to address this issue and consider the implementation of a scientifically validated structured interview protocol in Portugal. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Three Cd(II) MOFs with Different Functional Groups: Selective CO2 Capture and Metal Ions Detection.

PubMed

Wang, Zhong-Jie; Han, Li-Juan; Gao, Xiang-Jing; Zheng, He-Gen

2018-05-07

Three Cd(II) iso-frameworks {[Cd(BIPA)(IPA)]·DMF} n (1), {[Cd(BIPA)(HIPA)]·DMF} n (2), and {[Cd(BIPA)(NIPA)]·2H 2 O} n (3) were synthesized from the self-assembly of the BIPA ligand (BIPA = bis(4-(1 H-imidazol-1-yl)phenyl)amine) and different carboxylic ligands (H 2 IPA = isophthalic acid, H 2 HIPA = 5-hydroxyisophthalic acid, H 2 NIPA = 5-nitroisophthalic acid) with Cd(II), which have amino groups, amino and phenolic hydroxyl groups, and amino and nitro groups, respectively. Both 1 and 2 exhibit CO 2 uptakes of more than 20 wt %, indicating that amino and phenolic hydroxyl functionalized groups are beneficial to CO 2 adsorption. Their applications and mechanisms in detecting metal ions were researched. The results exhibit that 1 and 2 are dual-responsive photoluminescent sensors for Hg 2+ and Pb 2+ ions with low detection concentration and high quenching constant. Besides, like most MOFs, 3 can detect a trace quantity of Fe 3+ and Cu 2+ .

Kinetics and its accompanying thermodynamics studies on simultaneous complexation of heterobimetallic neodymium (III) with zinc (II) and L-tryptophan in aquated DMF using 4f-4f absorption spectra.

PubMed

Huidrom, Bimola; Singh, N Rajmuhon

2014-01-24

The 4f-4f absorption spectra of the simultaneous heterobimetallic complexation of trivalent neodymium ion with l-tryptophan and divalent zinc ion in aquated DMF (50%, v/v) at pH 6.0 was recorded at the time interval of 1h. From the observed absorption spectra, the values of intensity parameters such as oscillator strength (P) and Judd-Ofelt intensity (Tλ) parameters, kinetics and thermodynamics parameters were evaluated. The rate constant increases with an increase in the temperature along with the oscillator strengths and Judd-Ofelt intensity parameters. The positive values of the change in the standard enthalpy (ΔH°) and entropy (ΔS°) indicate that the complexation is endothermic. The negative values of the change in the standard free energy (ΔG°) in the range from 293.15 K to 308.15 K, indicate that the reaction occurs spontaneously and hence the formation of heterobimetallic complex in the solution is favored kinetically and thermodynamically. Copyright © 2013 Elsevier B.V. All rights reserved.

Kinetics and its accompanying thermodynamics studies on simultaneous complexation of heterobimetallic neodymium (III) with zinc (II) and L-tryptophan in aquated DMF using 4f-4f absorption spectra

NASA Astrophysics Data System (ADS)

Huidrom, Bimola; Rajmuhon Singh, N.

2014-01-01

The 4f-4f absorption spectra of the simultaneous heterobimetallic complexation of trivalent neodymium ion with L-tryptophan and divalent zinc ion in aquated DMF (50%, v/v) at pH 6.0 was recorded at the time interval of 1 h. From the observed absorption spectra, the values of intensity parameters such as oscillator strength (P) and Judd-Ofelt intensity (Tλ) parameters, kinetics and thermodynamics parameters were evaluated. The rate constant increases with an increase in the temperature along with the oscillator strengths and Judd-Ofelt intensity parameters. The positive values of the change in the standard enthalpy (ΔH°) and entropy (ΔS°) indicate that the complexation is endothermic. The negative values of the change in the standard free energy (ΔG°) in the range from 293.15 K to 308.15 K, indicate that the reaction occurs spontaneously and hence the formation of heterobimetallic complex in the solution is favored kinetically and thermodynamically.

Steady-state and time-resolved studies on the photophysical properties of fullerene-pyropheophorbide a complexes in polar and nonpolar solvents

NASA Astrophysics Data System (ADS)

Ermilov, E. A.; Al-Omari, S.; Helmreich, M.; Jux, N.; Hirsch, A.; Röder, B.

2004-04-01

A novel monofullerene-bis(pyropheophorbide a) dyad has been photophysically characterized by steady-state as well as time-resolved techniques. It was revealed that in this complex strong and fast quenching of the first excited singlet state of the pyropheophorbide a (pyroPheo) molecule occurs by efficient photoinduced electron transfer to the fullerene moiety in both polar (DMF) and nonpolar (toluene) solvents. In DMF the energy of the charge-separated state is 0.94 eV and it undergoes directly transition to the ground state resulting in a very low value of photosensitized singlet oxygen generation. In contrast to the situation in a polar solvent, in toluene the charge-separated state lies above the exited triplet state of pyroPheo as well as that of C 60. It has been shown that in a nonpolar solvent a sufficient amount of singlet oxygen was generated by energy transfer from the excited triplet state of pyroPheo which has been populated via relaxation of the charge-separated state.

Evolution of the Copper Surface in the Course of Oxidation by CCl4-L (L=THF, Dmf, Dmso): Scanning Probe Microscope Study

NASA Astrophysics Data System (ADS)

Panteleev, S. V.; Maslennikov, S. V.; Ignatov, S. K.; Spirina, I. V.; Kruglova, M. V.; Gribkov, B. A.; Vdovichev, S. N.

2013-04-01

The evolution of compact surface of the 100 nm copper film deposited on the glass-ceramics doped with vanadium coating in the course of the oxidation by the CCl4-L (L = dimethylformamide (DMF), tetrahydrofuran (THF), dimethylsulfoxide (DMSO), CCl4 concentration ≈ 1 mol/L) was studied by atomic force microscopy (AFM) in contact mode. The dynamics of active centers formation and destruction was investigated in the course of the oxidation process. The metallic sample dissolution rate was estimated as a function of the coordinating solvent nature. The development of the metal surface oxidation was established to lead to a significant increase of surface roughness. This phenomenon can be explained by the fact that different parts of the surface react at different rates. Further course of the reaction leads to a significant decrease of the surface roughness of copper films. The amount of the metal reacted has an almost linear dependence on the reaction time. AFM scans indicate that there is the same mechanism of the reaction between copper and carbon tetrachloride for all solvents.

3D lanthanide metal-organic frameworks constructed from 2,6-naphthalenedicarboxylate ligand: synthesis, structure, luminescence and dye adsorption

NASA Astrophysics Data System (ADS)

Zhu, Yajing; Wang, Li; Chen, Xiaodong; Wang, Pengcheng; Fan, Yong; Zhang, Ping

2017-07-01

A series of novel isostructural 3D lanthanide metal-organic frameworks {[Ln2(NDC)3(H2O)4]·(DMF)4}n (Ln=Eu(1), Gd(2), Tb(3), Er(4), Yb(5), Dy(6), Y(7), Lu(8), H2NDC =2,6-Naphthalenedicarboxylic acid, DMF=N,N-dimethylformamide) with a rhombic channel along the b axis and high thermal stabilities, have been successfully synthesized under solvothermal conditions. The network can be described as 2, 4, 5-connected net with Schäfli symbol of (42.62.82)2(42.63.85)2(6). Luminescent studies illustrate that 1, 2, 7 and 8 exhibit strong luminescent emitting of the corresponding Ln(III) centers in the visible range, while 5 shows near-infrared range (NIR) luminescence. Further studies of 1 and 2A (activated product of 2) show that 1 displays good stability in different solvents and excellent fluorescence sensing for organic solvent small molecules and 2A ([Gd2(NDC)3(H2O)4]n) exhibits good adsorption capacity for organic dyes in water, especially for crystal violet.

Spectra, energy levels, and energy transition of lanthanide complexes with cinnamic acid and its derivatives.

PubMed

Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju

2016-04-05

High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L=cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF=N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu(3+) in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu(3+) ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of (5)D0 and triplet state contracts. Copyright © 2016 Elsevier B.V. All rights reserved.

Crystallization-driven one-dimensional self-assembly of polyethylene-b-poly(tert-butylacrylate) diblock copolymers in DMF: effects of crystallization temperature and the corona-forming block.

PubMed

Fan, Bin; Liu, Lei; Li, Jun-Huan; Ke, Xi-Xian; Xu, Jun-Ting; Du, Bin-Yang; Fan, Zhi-Qiang

2016-01-07

Crystallization-driven self-assembly of polyethylene-b-poly(tert-butylacrylate) (PE-b-PtBA) block copolymers (BCPs) in N,N-dimethyl formamide (DMF) was studied. It is found that all three PE-b-PtBA BCPs used in this work can self-assemble into one-dimensional crystalline cylindrical micelles. When the BCP solution is cooled to crystallization temperature (Tc) from 130 °C, the seed micelles may be produced via two competitive processes in the initial period: stepwise micellization/crystallization and simultaneous crystallization/micellization. Subsequently, the seed micelles can undergo growth driven by the epitaxial crystallization of the unimers. The lengths of both the seed micelles and the grown micelles are longer for the BCP with a longer PtBA block at a higher Tc. Quasi-living growth of the PE-b-PtBA crystalline cylindrical micelles is achieved at a higher Tc. A longer PtBA block evidently retards the attachment of unimers to the crystalline micelles, leading to a slower growth rate.

Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

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

Meckler, Stephen M.; Li, Changyi; Queen, Wendy L.

2015-11-02

Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presencemore » of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.« less

Review and Recommendations for Zero-inflated Count Regression Modeling of Dental Caries Indices in Epidemiological Studies

PubMed Central

Stamm, John W.; Long, D. Leann; Kincade, Megan E.

2012-01-01

Over the past five to ten years, zero-inflated count regression models have been increasingly applied to the analysis of dental caries indices (e.g., DMFT, dfms, etc). The main reason for that is linked to the broad decline in children’s caries experience, such that dmf and DMF indices more frequently generate low or even zero counts. This article specifically reviews the application of zero-inflated Poisson and zero-inflated negative binomial regression models to dental caries, with emphasis on the description of the models and the interpretation of fitted model results given the study goals. The review finds that interpretations provided in the published caries research are often imprecise or inadvertently misleading, particularly with respect to failing to discriminate between inference for the class of susceptible persons defined by such models and inference for the sampled population in terms of overall exposure effects. Recommendations are provided to enhance the use as well as the interpretation and reporting of results of count regression models when applied to epidemiological studies of dental caries. PMID:22710271

Calcium Coordination Solids for pH-Triggered Release of Olsalazine

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

Levine, Dana J.; Gonzalez, Miguel I.; Legendre, Christina M.

Here, calcium coordination solids were synthesized and evaluated for delivery of olsalazine (H 4olz), an anti-inflammatory compound used for treatment of ulcerative colitis. The materials include one-dimensional Ca(H 2olz)•4H 2O chains, two-dimensional Ca(H 2olz)•2H 2O sheets, and a three-dimensional metal-organic framework Ca(H 2olz)•2DMF (DMF= N,N-dimethylformamide). The framework undergoes structural changes in response to solvent, forming a dense Ca(H 2olz) phase when exposed to aqueous HCl. The compounds Ca(H 2olz)•xH 2O (x=0, 2, 4) were each pressed into pellets and exposed to simulated gastrointestinal fluids to mimic the passage of a pill from the acidic stomach to the pH-neutral intestines. Allmore » three calcium materials exhibited a delayed release of olsalazine relative to Na 2(H 2olz), the commercial formulation, illustrating how formulation of a drug within an extended coordination solid can serve to tune its solubility and performance.« less

Calcium Coordination Solids for pH-Triggered Release of Olsalazine

DOE PAGES

Levine, Dana J.; Gonzalez, Miguel I.; Legendre, Christina M.; ...

2017-09-12

Here, calcium coordination solids were synthesized and evaluated for delivery of olsalazine (H 4olz), an anti-inflammatory compound used for treatment of ulcerative colitis. The materials include one-dimensional Ca(H 2olz)•4H 2O chains, two-dimensional Ca(H 2olz)•2H 2O sheets, and a three-dimensional metal-organic framework Ca(H 2olz)•2DMF (DMF= N,N-dimethylformamide). The framework undergoes structural changes in response to solvent, forming a dense Ca(H 2olz) phase when exposed to aqueous HCl. The compounds Ca(H 2olz)•xH 2O (x=0, 2, 4) were each pressed into pellets and exposed to simulated gastrointestinal fluids to mimic the passage of a pill from the acidic stomach to the pH-neutral intestines. Allmore » three calcium materials exhibited a delayed release of olsalazine relative to Na 2(H 2olz), the commercial formulation, illustrating how formulation of a drug within an extended coordination solid can serve to tune its solubility and performance.« less

Amphiphilic inclusion spaces for various guests and regulation of fluorescence intensity of 1,8-bis(4-aminophenyl)anthracene crystals.

PubMed

Sugino, Misa; Hatanaka, Keisuke; Araki, Yusuke; Hisaki, Ichiro; Miyata, Mikiji; Tohnai, Norimitsu

2014-03-10

A host framework for inclusion of various guest molecules was investigated by preparation of inclusion crystals of 1,8-bis(4-aminophenyl)anthracene (1,8-BAPA) with organic solvents. X-ray crystallographic analysis revealed construction of the same inclusion space incorporating 1,8-BAPA and eight guest molecules including both non-polar (benzene) and polar guests (N,N-dimethylformamide, DMF). Fluorescence efficiencies varied depending on guest molecule polarity; DMF inclusion crystals exhibited the highest fluorescence intensity (ΦF=0.40), four times as high as that of a benzene inclusion crystal (ΦF=0.10). According to systematic investigations of inclusion phenomena, strong host–guest interactions and filling of the inclusion space led to a high fluorescence intensity. Temperature-dependent fluorescence spectral measurements revealed these factors effectively immobilised the host framework. Although hydrogen bonding commonly decreases fluorescence intensity, the present study demonstrated that such strong interactions provide excellent conditions for fluorescence enhancement. Thus, this remarkable behaviour has potential application toward sensing of highly polar molecules, such as biogenic compounds.

Atmospheric Radiation Measurement's Data Management Facility captures metadata and uses visualization tools to assist in routine data management.

NASA Astrophysics Data System (ADS)

Keck, N. N.; Macduff, M.; Martin, T.

2017-12-01

The Atmospheric Radiation Measurement's (ARM) Data Management Facility (DMF) plays a critical support role in processing and curating data generated by the Department of Energy's ARM Program. Data are collected near real time from hundreds of observational instruments spread out all over the globe. Data are then ingested hourly to provide time series data in NetCDF (network Common Data Format) and includes standardized metadata. Based on automated processes and a variety of user reviews the data may need to be reprocessed. Final data sets are then stored and accessed by users through the ARM Archive. Over the course of 20 years, a suite of data visualization tools have been developed to facilitate the operational processes to manage and maintain the more than 18,000 real time events, that move 1.3 TB of data each day through the various stages of the DMF's data system. This poster will present the resources and methodology used to capture metadata and the tools that assist in routine data management and discoverability.

Sub-micron Polymer–Zeolitic Imidazolate Framework Layered Hybrids via Controlled Chemical Transformation of Naked ZnO Nanocrystal Films

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

Meckler, Stephen M.; Li, Changyi; Queen, Wendy L.

Here we show that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF–ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films. Grazing incidence X-ray diffraction was used to confirm the presencemore » of crystalline ZIF in the thin films, and X-ray absorption spectroscopy was used to quantify film purity, revealing films with little to no residual ZnO. The role solvent plays in the transformation mechanism is discussed in light of these findings, which suggest the ZnO nanocrystals may be necessary to localize heterogeneous nucleation of the ZIF to the polymer surface.« less

The influence of solvent on the UV-visible absorption and luminescence spectra of some highly fluorescent vitamin derivatives, the products of the reaction of N-methylated vitamin Bj with cytidine (I), adenosine (II) and 2-amino-4-methylpyridine (III) is studied. Spectroscopic manifestations of protonation of I and II are also investigated using a semiempirical INDO/S CI method. Singlet and triplet energy levels of the free ion and several protonated species are calculated, and transition energies and oscillator strengths are compared with the experimental spectra. Calculated charge densities on heteroatoms in the ground and excited singlet and triplet states are correlated with changes of the experimental pKa values with excitation. The results for I and II are compared with those for the trimethylated pyrichrominium ion (III) previously studied

NASA Astrophysics Data System (ADS)

Muralimohan Rao, D.; Kalidas, C.

1990-08-01

The conductance of HCl and HBr in water-dimethylformamide (DMF) mixtures of 10-80 wt % DMF at 25 ºC has been measured and discussed, using the three parameter conductance equation suggested by Fuoss et al. in 1965. The ionic conductances and Waiden products of the H + , C - and Br- ions have been determined and explained. No appreciable ion-association of these acids in these media has been found

X-ray photoelectron spectroscopy characterization of composite TiO 2-poly(vinylidenefluoride) films synthesised for applications in pesticide photocatalytic degradation

NASA Astrophysics Data System (ADS)

Losito, I.; Amorisco, A.; Palmisano, F.; Zambonin, P. G.

2005-02-01

X-ray photoelectron spectroscopy (XPS) was adopted for the analytical characterization of composite titanium dioxide-poly(vinylidenefluoride) (TiO 2-PVDF) films developed for applications in the photocatalytic degradation of pollutants. The composites were deposited on glass substrates by casting or spin coating from TiO 2-PVDF suspensions in dimethylformamide (DMF). XPS data on the TiO 2-PVDF surface composition were used to optimize preparation conditions (composition of the TiO 2/PVDF suspension, deposition technique) in terms of titanium dioxide surface amount and film stability. The use of spin-coating deposition and the increase of TiO 2 amount in the DMF suspensions were found to improve the titanium surface content, although high TiO 2/PVDF ratios led to film instability. PVDF-TiO 2 films were also used in preliminary photocatalytic degradation tests on isoproturon, a phenylurea herbicide, under solar UV irradiation; the results were compared to direct photolysis to evaluate the catalytic efficiency of immobilized TiO 2 and the role played by the PVDF film during the degradation process.

[Separation of catechins and caffeine in tea polyphenol by isocratic elution high performance liquid chromatography].

PubMed

Tang, G Y; Wu, H J; Wu, L; Li, Z J; Yao, Y G

2001-05-01

The catechins, particularly in green tea, have been found to possess anti-mutagenic and anti-tumorigenic properties. As each catechin possesses distinct properties, a simple and rapid method that could be used for analysis of individual catechins in a complex mixture would be necessary. A relatively simple and rapid method for simultaneous separation of five catechins and caffeine in tea polyphenol by isocratic elution high performance liquid chromatography has been developed. The analysis could be finished within 30 min. They were measured using Resolve C18 column (at 43 degrees C) and UV detector (at 280 nm), water-85% phosphoric acid aqueous solution-acetonitrile-dimethyl formamide(DMF) (859:1:120:20, V/V) as mobile phase. There was a good linear relationship between the content of component and its peak area for catechins and caffeine, with the correlation coefficients of 0.9992-0.9999. The average recoveries (n = 5) were 83.33%-104.42%, and the relative standard deviations (n = 6) were 0.74%-1.43%. The effect of concentration of DMF in mobile phase was studied.

Experiences From NASA/Langley's DMSS Project

NASA Technical Reports Server (NTRS)

1996-01-01

There is a trend in institutions with high performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high speed network. The Distributed Mass Storage System (DMSS) Project at the NASA Langley Research Center (LaRC) has placed such a system into production use. This paper will present the experiences, both good and bad, we have had with this system since putting it into production usage. The system is comprised of: 1) National Storage Laboratory (NSL)/UniTree 2.1, 2) IBM 9570 HIPPI attached disk arrays (both RAID 3 and RAID 5), 3) IBM RS6000 server, 4) HIPPI/IPI3 third party transfers between the disk array systems and the supercomputer clients, a CRAY Y-MP and a CRAY 2, 5) a "warm spare" file server, 6) transition software to convert from CRAY's Data Migration Facility (DMF) based system to DMSS, 7) an NSC PS32 HIPPI switch, and 8) a STK 4490 robotic library accessed from the IBM RS6000 block mux interface. This paper will cover: the performance of the DMSS in the following areas: file transfer rates, migration and recall, and file manipulation (listing, deleting, etc.); the appropriateness of a workstation class of file server for NSL/UniTree with LaRC's present storage requirements in mind the role of the third party transfers between the supercomputers and the DMSS disk array systems in DMSS; a detailed comparison (both in performance and functionality) between the DMF and DMSS systems LaRC's enhancements to the NSL/UniTree system administration environment the mechanism for DMSS to provide file server redundancy the statistics on the availability of DMSS the design and experiences with the locally developed transparent transition software which allowed us to make over 1.5 million DMF files available to NSL/UniTree with minimal system outage

Kinetic Analysis of Competitive Electrocatalytic Pathways: New Insights into Hydrogen Production with Nickel Electrocatalysts

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

Wiedner, Eric S.; Brown, Houston J.; Helm, Monte L.

2016-01-20

The hydrogen production electrocatalyst Ni(PPh2NPh2)22+ (1) is capable of traversing multiple electrocatalytic pathways. When using dimethylformamidium, DMF(H)+, the mechanism of formation of H2 catalyzed by 1 changes from an ECEC to an EECC mechanism as the potential approaches the Ni(I/0) couple. Two recent electrochemical methods, current-potential analysis and foot-of-the-wave analysis (FOWA), were performed on 1 to measure the detailed chemical kinetics of the competing ECEC and EECC pathways. A sensitivity analysis was performed on the electrochemical methods using digital simulations to gain a better understanding of their strengths and limitations. Notably, chemical rate constants were significantly underestimated when not accountingmore » for electron transfer kinetics, even when electron transfer was fast enough to afford a reversible non-catalytic wave. The EECC pathway of 1 was found to be faster than the ECEC pathway under all conditions studied. Using buffered DMF: DMF(H)+ mixtures led to an increase in the catalytic rate constant (kobs) of the EECC pathway, but kobs for the ECEC pathway did not change when using buffered acid. Further kinetic analysis of the ECEC path revealed that added base increases the rate of isomerization of the exo-protonated Ni(0) isomers to the catalytically active endo-isomers, but decreases the net rate of protonation of Ni(I). FOWA on 1 did not provide accurate rate constants due to incomplete reduction of the exo-protonated Ni(I) intermediate at the foot of the wave, but FOWA could be used to estimate the reduction potential of this previously undetected intermediate. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.« less

GAMA/H-ATLAS: The Local Dust Mass Function and Cosmic Density as a Function of Galaxy Type - A Benchmark for Models of Galaxy Evolution

NASA Astrophysics Data System (ADS)

Beeston, R. A.; Wright, A. H.; Maddox, S.; Gomez, H. L.; Dunne, L.; Driver, S. P.; Robotham, A.; Clark, C. J. R.; Vinsen, K.; Takeuchi, T. T.; Popping, G.; Bourne, N.; Bremer, M. N.; Phillipps, S.; Moffett, A. J.; Baes, M.; Bland-Hawthorn, J.; Brough, S.; De Vis, P.; Eales, S. A.; Holwerda, B. W.; Loveday, J.; Liske, J.; Smith, M. W. L.; Smith, D. J. B.; Valiante, E.; Vlahakis, C.; Wang, L.

2018-06-01

We present the dust mass function (DMF) of 15,750 galaxies with redshift z < 0.1, drawn from the overlapping area of the GAMA and H-ATLAS surveys. The DMF is derived using the density corrected Vmax method, where we estimate Vmax using: (i) the normal photometric selection limit (pVmax) and (ii) a bivariate brightness distribution (BBD) technique, which accounts for two selection effects. We fit the data with a Schechter function, and find M^{*}=(4.65 ± 0.18)× 107 h^2_{70} M_{⊙ }, α = ( - 1.22 ± 0.01), φ ^{*}=(6.26 ± 0.28)× 10^{-3} h^3_{70} Mpc^{-3} dex^{-1}. The resulting dust mass density parameter integrated down to 104 M⊙ is Ωd = (1.11 ± 0.02) × 10-6 which implies the mass fraction of baryons in dust is f_{m_b}=(2.40± 0.04)× 10^{-5}; cosmic variance adds an extra 7-17 per cent uncertainty to the quoted statistical errors. Our measurements have fewer galaxies with high dust mass than predicted by semi-analytic models. This is because the models include too much dust in high stellar mass galaxies. Conversely, our measurements find more galaxies with high dust mass than predicted by hydrodynamical cosmological simulations. This is likely to be from the long timescales for grain growth assumed in the models. We calculate DMFs split by galaxy type and find dust mass densities of Ωd = (0.88 ± 0.03) × 10-6 and Ωd = (0.060 ± 0.005) × 10-6 for late-types and early-types respectively. Comparing to the equivalent galaxy stellar mass functions (GSMF) we find that the DMF for late-types is well matched by the GMSF scaled by (8.07 ± 0.35) × 10-4.

The cost-effectiveness of disease-modifying therapies for the treatment of relapsing-remitting multiple sclerosis.

PubMed

Bozkaya, Duygu; Livingston, Terrie; Migliaccio-Walle, Kristen; Odom, Tanner

2017-03-01

The safety and efficacy of disease-modifying therapies (DMTs) for relapsing-remitting multiple sclerosis (RRMS) has been established; however, it is not clear which provides optimal value, given benefit-risk profiles and costs. To compare the cost-effectiveness of current DMTs for patients with RRMS in the US. A Markov model predicting RRMS course following initiation of a DMT was created comparing outcomes (e.g. relapses, disease progression) and costs of natalizumab (NTZ), dimethyl fumarate (DMF), and peginterferon beta-1a (PEG) with fingolimod (FIN), glatiramer acetate (GA, 20 mg daily), and subcutaneous interferon beta-1a (IFN, 44 mcg), respectively, over 10 years. RRMS and secondary-progressive MS (SPMS) EDSS state transitions were predicted in 3-month cycles in which patients were at risk of death, relapse, or discontinuation. Upon DMT discontinuation, natural history progression and relapse rates were applied. Incremental cost-effectiveness ratios (ICERs) were estimated for the cost per relapse avoided, relapse-free years gained, progression avoided, and progression-free years gained. The impact of model parameters on outcomes was evaluated via one-way sensitivity analyses. Costs ranged from $561,177 (NTZ) to $616,251 (GA). NTZ, DMF, and PEG were dominant (less costly and more effective) compared to FIN, GA, and IFN, respectively, for all ICERs. Variability in drug costs and parameters that affected drug cost accrual (e.g. discontinuation rates and the decision to drop out after SPMS conversion) had a considerable impact on ICERs. Several simplifying assumptions were made that may represent potential limitations of this analysis (e.g. a constant treatment effect over time was assumed). The results from this analysis suggest that the NTZ, DMF, and PEG are cost-effective DMT choices compared to FIN, GA, and IFN, respectively. The actual impact on a particular plan will vary based on drug pricing and other factors affecting drug cost accrual.

Theoretical studies of the transition state structures and free energy barriers for base-catalyzed hydrolysis of amides

PubMed Central

Xiong, Ying; Zhan, Chang-Guo

2010-01-01

The transition state structures and free energy barriers for the rate-determining step (i.e. the formation of a tetrahedral intermediate) of base-catalyzed hydrolysis of a series of amides in aqueous solution have been studied by performing first-principle electronic structure calculations using a hybrid supermolecule-polarizable continuum approach. The calculated results and a revisit of recently reported experimental proton inventory data reveal that the favorable transition state structure optimized for the tetrahedral intermediate formation of hydroxide ion-catalyzed hydrolysis of formamide may have three solvating water molecules remaining on the attacking hydroxide oxygen and two additional water molecules attached to the carbonyl oxygen of formamide. The calculated results have also demonstrated interesting substituent effects on the optimized transition state geometries, on the transition-state stabilization, and on the calculated free energy barriers for the base-catalyzed hydrolysis of amides. When some or all of the hydrogen atoms of formamide are replaced by methyl groups, the total number of water molecules hydrogen-bonding with the attacking hydroxide in the transition state decreases from three for formamide to two for N-methylacetamide, N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMA). The larger substituents of the amide hinder the solvent water molecules approaching the attacking hydroxide oxygen in the transition state and, therefore, destabilize the transition state structure and increase the free energy barrier. By using the optimized most favorable transition state structures, the calculated free energy barriers, i.e. 21.6 (or 21.7), 22.7, 23.1, and 26.0 kcal/mol for formamide, N-methylacetamide, DMF, and DMA, respectively, are in good agreement with the available experimental free energy barriers, i.e. 21.2, 21.5, 22.6, and 24.1 kcal/mol for formamide, N-methylacetamide, DMF, and DMA, respectively. PMID:17107116

Selective, tunable O 2 binding in cobalt(II)–triazolate/pyrazolate metal–organic frameworks

DOE PAGES

Xiao, Dianne J.; Gonzalez, Miguel I.; Darago, Lucy E.; ...

2016-05-16

Here, the air-free reaction of CoCl 2 with 1,3,5-tri(1H- 1,2,3-triazol-5-yl)benzene (H 3BTTri) in N,N-dimethylformamide (DMF) and methanol leads to the formation of Co- BTTri (Co 3[(Co 4Cl) 3(BTTri) 8] 2·DMF), a sodalite-type metal-organic framework. Desolvation of this material generates coordinatively unsaturated low-spin cobalt(II) centers that exhibit a strong preference for binding O 2 over N 2, with isosteric heats of adsorption (Q st) of -34(1) and -12(1) kJ/ mol, respectively. The low-spin (S = 1/2) electronic configuration of the metal centers in the desolvated framework is supported by structural, magnetic susceptibility, and computational studies. A single-crystal X-ray structure determination revealsmore » that O 2 binds end-on to each framework cobalt center in a 1:1 ratio with a Co-O 2 bond distance of 1.973(6) Å. Replacement of one of the triazolate linkers with a more electron-donating pyrazolate group leads to the isostructural framework Co-BDTriP (Co 3[(Co 4Cl) 3(BDTriP) 8] 2·DMF; H 3BDTriP = 5,5'-(5-(1H-pyrazol-4-yl)-1,3-phenylene)bis(1H-1,2,3-triazole)), which demonstrates markedly higher yet still fully reversible O 2 affinities (Q st = -47(1) kJ/mol at low loadings). Electronic structure calculations suggest that the O 2 adducts in Co-BTTri are best described as cobalt(II)-dioxygen species with partial electron transfer, while the stronger binding sites in Co-BDTriP form cobalt(III)-superoxo moieties. The stability, selectivity, and high O 2 adsorption capacity of these materials render them promising new adsorbents for air separation processes.« less

Quantification of transformation products of rocket fuel unsymmetrical dimethylhydrazine in soils using SPME and GC-MS.

PubMed

Bakaikina, Nadezhda V; Kenessov, Bulat; Ul'yanovskii, Nikolay V; Kosyakov, Dmitry S

2018-07-01

Determination of transformation products (TPs) of rocket fuel unsymmetrical dimethylhydrazine (UDMH) in soil is highly important for environmental impact assessment of the launches of heavy space rockets from Kazakhstan, Russia, China and India. The method based on headspace solid-phase microextraction (HS SPME) and gas chromatography-mass spectrometry is advantageous over other known methods due to greater simplicity and cost efficiency. However, accurate quantification of these analytes using HS SPME is limited by the matrix effect. In this research, we proposed using internal standard and standard addition calibrations to achieve proper combination of accuracies of the quantification of key TPs of UDMH and cost efficiency. 1-Trideuteromethyl-1H-1,2,4-triazole (MTA-d3) was used as the internal standard. Internal standard calibration allowed controlling matrix effects during quantification of 1-methyl-1H-1,2,4-triazole (MTA), N,N-dimethylformamide (DMF), and N-nitrosodimethylamine (NDMA) in soils with humus content < 1%. Using SPME at 60 °C for 15 min by 65 µm Carboxen/polydimethylsiloxane fiber, recoveries of MTA, DMF and NDMA for sandy and loamy soil samples were 91-117, 85-123 and 64-132%, respectively. For improving the method accuracy and widening the range of analytes, standard addition and its combination with internal standard calibration were tested and compared on real soil samples. The combined calibration approach provided greatest accuracies for NDMA, DMF, N-methylformamide, formamide, 1H-pyrazole, 3-methyl-1H-pyrazole and 1H-pyrazole. For determination of 1-formyl-2,2-dimethylhydrazine, 3,5-dimethylpyrazole, 2-ethyl-1H-imidazole, 1H-imidazole, 1H-1,2,4-triazole, pyrazines and pyridines, standard addition calibration is more suitable. However, the proposed approach and collected data allow using both approaches simultaneously. Copyright © 2018 Elsevier B.V. All rights reserved.

Related factors of dental caries and molar incisor hypomineralisation in a group of children with cystic fibrosis.

PubMed

Peker, S; Mete, S; Gokdemir, Y; Karadag, B; Kargul, B

2014-08-01

To investigate dental caries and molar incisor hypomineralisation (MIH)-related factors such as treatment, diet, brushing and salivary factors in children with cystic fibrosis (CF) compared with healthy peers. A cohort study was performed. This study was performed on 30 CF children comprising patients at the Faculty of Medicine and 30 control children recruited from the Dental School. Salivary factors, dental caries, MIH, daily diet, brushing habits were analysed. Statistical analysis was calculated by SPSS for Windows. Decay missing filled teeth (DMF-T) score was 4.6 ± 4.0 in CF and 7.7 ± 2.7 in control (p = 0.001). 43% of CF children with MIH were found to use antibiotics, but no significant difference in the caries experience was found with antibiotic usage (p > 0.05). DMF-T of CF adolescents (23%) who use Tobramycin was 7 ± 3.5. DMF-T of CF children (20%) who take other antibiotics was 2.5 ± 3.5, but no statistical difference was found (p = 0.054). Saliva pH, salivary flow rate, and buffering capacity were not found statistically significant (p > 0.05). Percentage arithmetic mean value, standard deviation, independent sample t test, Fisher's exact test, Chi-square test and Mann-Whitney U test were used, while a p value of <0.05 was considered statistically significant. Medication and diet could be considered as a risk factor for dental caries and factors such as salivary pH, good oral hygiene could play a protective role for oral health CF children. MIH frequency and lower caries experience seen in CF children could be due to salivary factors or pharmacological treatment they take. The multidisciplinary approach team would be advantageous in the management of children with CF and oral health should be under control during early years of life by paediatric dentists.

Evaluation of Cryoprotectant and Cooling Rate for Sperm Cryopreservation in the Euryhaline Fish Medaka Oryzias latipes

PubMed Central

Yang, Huiping; Norris, Michelle; Winn, Richard; Tiersch, Terrence R.

2017-01-01

Medaka Oryzias latipes is a well-recognized biomedical fish model because of advantageous features such as small body size, transparency of embryos, and established techniques for gene knockout and modification. The goal of this study was to evaluate two critical factors, cryoprotectant and cooling rate, for sperm cryopreservation in 0.25-ml French straws. The objectives were to: 1) evaluate the acute toxicity of methanol, 2-methoxyethanol (ME), dimethyl sulfoxide (Me2SO), N, N- dimethylacetamide (DMA), N, N,-dimethyl formamide (DMF), and glycerol with concentrations of 5, 10, and 15% for 60 min of incubation at 4 °C; 2) evaluate cooling rates from 5 to 25 °C/min for freezing and their interaction with cryoprotectants, and 3) test fertility of thawed sperm cryopreserved with selected cryoprotectants and associated cooling rates. Evaluation of cryoprotectant toxicity showed that methanol and ME (5 and 10%) did not change the sperm motility after 30 min; Me2SO, DMA, and DMF (10 and 15%) and glycerol (5, 10 and 15%) significantly decreased the motility of sperm within 1 min after mixing. Based on these results, methanol and ME were selected as cryoprotectants (10%) to evaluate with different cooling rates (from 5 °C/min to 25 °C/min) and were compared to Me2SO and DMF (10%) (based on their use as cryoprotectants in previous publications). Post-thaw motility was affected by cryoprotectant, cooling rate, and their interaction (P ≤ 0.000). The highest post-thaw motility (50 ± 10%) was observed at a cooling rate of 10 °C/min with methanol as cryoprotectant. Comparable post-thaw motility (37 ± 12%) was obtained at a cooling rate of 15 °C/min with ME as cryoprotectant. With DMF, post-thaw motility at all cooling rates was ≤ 10% which was significantly lower than that of methanol and ME. With Me2SO, post-thaw motilities were less than 1% at all cooling rates, and significantly lower compared to the other three cryoprotectants (P ≤ 0.000). When sperm from individual males were cryopreserved with 10% methanol at a cooling rate of 10 °C/min and 10% ME with a rate of 15 °C/min, no difference was found in post-thaw motility. Fertility testing of thawed sperm cryopreserved with 10% methanol at a rate of 10 °C/min showed average hatching of 70 ± 30% which was comparable to that of fresh sperm (86 ± 15%). Overall, this study established a baseline for high-throughput sperm cryopreservation of medaka provides an outline for protocol standardization and use of automated processing equipment in the future. PMID:20654608

Surface decorated platinum carbonyl clusters

NASA Astrophysics Data System (ADS)

Ciabatti, Iacopo; Femoni, Cristina; Iapalucci, Maria Carmela; Longoni, Giuliano; Zacchini, Stefano; Zarra, Salvatore

2012-06-01

Four molecular Pt-carbonyl clusters decorated by Cd-Br fragments, i.e., [Pt13(CO)12{Cd5(μ-Br)5Br2(dmf)3}2]2- (1), [Pt19(CO)17{Cd5(μ-Br)5Br3(Me2CO)2}{Cd5(μ-Br)5Br(Me2CO)4}]2- (2), [H2Pt26(CO)20(CdBr)12]8- (3) and [H4Pt26(CO)20(CdBr)12(PtBr)x]6- (4) (x = 0-2), have been obtained from the reactions between [Pt3n(CO)6n]2- (n = 2-6) and CdBr2.H2O in dmf at 120 °C. The structures of these molecular clusters with diameters of 1.5-2 nm have been determined by X-ray crystallography. Both 1 and 2 are composed of icosahedral or bis-icosahedral Pt-CO cores decorated on the surface by Cd-Br motifs, whereas 3 and 4 display a cubic close packed Pt26Cd12 metal frame decorated by CO and Br ligands. An oversimplified and unifying approach to interpret the electron count of these surface decorated platinum carbonyl clusters is suggested, and extended to other low-valent organometallic clusters and Au-thiolate nanoclusters.Four molecular Pt-carbonyl clusters decorated by Cd-Br fragments, i.e., [Pt13(CO)12{Cd5(μ-Br)5Br2(dmf)3}2]2- (1), [Pt19(CO)17{Cd5(μ-Br)5Br3(Me2CO)2}{Cd5(μ-Br)5Br(Me2CO)4}]2- (2), [H2Pt26(CO)20(CdBr)12]8- (3) and [H4Pt26(CO)20(CdBr)12(PtBr)x]6- (4) (x = 0-2), have been obtained from the reactions between [Pt3n(CO)6n]2- (n = 2-6) and CdBr2.H2O in dmf at 120 °C. The structures of these molecular clusters with diameters of 1.5-2 nm have been determined by X-ray crystallography. Both 1 and 2 are composed of icosahedral or bis-icosahedral Pt-CO cores decorated on the surface by Cd-Br motifs, whereas 3 and 4 display a cubic close packed Pt26Cd12 metal frame decorated by CO and Br ligands. An oversimplified and unifying approach to interpret the electron count of these surface decorated platinum carbonyl clusters is suggested, and extended to other low-valent organometallic clusters and Au-thiolate nanoclusters. CCDC 867747 and 867748. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c2nr30400g

Characterization of thermal and mechanical properties of opligo(glycerol-glutaric acid)s

USDA-ARS?s Scientific Manuscript database

Dibutyltin oxide was used to catalyze the synthesis of oligo(glycerol-glutaric acid)s in the absence and presence of solvent. Reaction times were either 10h or 24h for reactions performed in DMF and 24h for the neat reaction. The oligomers were obtained on average in 84% yield and were characteriz...

[10-years caries incidence and intensity dynamics in pregnant women of Derbent city].

PubMed

Bakhmudov, B R; Alieva, Z B; Bakhmudov, M B

2012-01-01

Caries incidence was assessed in pregnant women in 1998, 2003 an 2008 showing the values to be stable. DMF was almost the same in 1998 and 2003, but in 2008 the rate of "F" (filled) element was significantly higher thus confirming growth in motivation for dental treatment after introduction of private dental practices.

76 FR 77243 - Information Collection Request to Office of Management and Budget; OMB Control Number: 1625-0010

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-12

... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2011-1074] Information Collection Request to... Guard docket number [USCG-2011-1074] to the Docket Management Facility (DMF) at the U.S. Department of..., [USCG-2011-1074], and must be received by February 10, 2012. We will post all comments received, without...

Rapid and enhanced activation of microporous coordination polymers by flowing supercritical CO.sub.2

DOEpatents

Matzger, Adam J.; Liu, Baojian; Wong-Foy, Antek G.

2016-07-19

Flowing supercritical CO.sub.2 is used to activate metal organic framework materials (MOF). MOFs are activated directly from N,N-dimethylformamide (DMF) thus avoiding exchange with a volatile solvent. Most MCPs display increased surface areas directly after treatment although those with coordinatively unsaturated metal centers benefit from additional heating.

76 FR 66739 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... following collection of information: 1625-0006, Shipping Articles. Our ICR describes the information we seek...., Washington, DC 20590-0001. (b) To OIRA, 725 17th Street NW., Washington, DC 20503, attention Desk Officer for..., attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this Notice. Comments...

75 FR 39552 - Collection of Information Under Review by Office of Management and Budget; OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-09

...) To OIRA, 725 17th Street, NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3... timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public..., U.S. Coast Guard, Acting Assistant Commandant for Command, Control, Communications, Computers and...

75 FR 31459 - Collection of Information Under Review by Office of Management and Budget: OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-03

...) To OIRA, 725 17th Street, NW., Washington, DC 20503, attention Desk Officer for the Coast Guard. (3... timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public..., U.S. Coast Guard, Acting Assistant Commandant for Command, Control, Communications, Computers and...

77 FR 39248 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

...., Washington, DC 20590-0001. (b) To OIRA, 725 17th Street NW., Washington, DC 20503, attention Desk Officer for..., attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this Notice. Comments...: June 22, 2012. R.E. Day, Rear Admiral, U.S. Coast Guard, Assistant Commandant for Command, Control...

76 FR 62427 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-07

...., Washington, DC 20590-0001. (b) To OIRA, 725 17th Street, NW., Washington, DC 20503, attention Desk Officer... the fax, attention Desk Officer for the Coast Guard. The DMF maintains the public docket for this...: September 30, 2011. R.E. Day, Rear Admiral, U.S. Coast Guard, Assistant Commandant for Command, Control...

75 FR 80514 - Collection of Information Under Review by Office of Management and Budget: OMB Control Numbers...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-22

...- 366-9329. (b) To OIRA, 725 17th Street, NW., Washington, DC 20503, attention Desk Officer for the... received in a timely manner, mark the fax, attention Desk Officer for the Coast Guard. The DMF maintains... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2010-32060...

Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility

Treesearch

Jeffrey Luo; Nikolay Semenikhin; Huibin Chang; Robert J. Moon; Satish Kumar

2018-01-01

Cellulose nanofibrils (CNF) were sulfonated and the dispersion quality was compared to unfunctionalized and 2,2,6,6-tetramethylpiperdine-1-oxyl radical (TEMPO) post-oxidation treatment of existing CNF (mechanically fibrillated pulp). A post-sulfonation treatment on existing CNF in chlorosulfonic acid and dimethylformamide (DMF) resulted in sulfonated CNF that retained...

Hierarchical storage management system evaluation

NASA Technical Reports Server (NTRS)

Woodrow, Thomas S.

1993-01-01

The Numerical Aerodynamic Simulation (NAS) Program at NASA Ames Research Center has been developing a hierarchical storage management system, NAStore, for some 6 years. This evaluation compares functionality, performance, reliability, and other factors of NAStore and three commercial alternatives. FileServ is found to be slightly better overall than NAStore and DMF. UniTree is found to be severely lacking in comparison.

76 FR 5817 - Collection of Information Under Review by Office of Management and Budget: OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-02

... Review by Office of Management and Budget: OMB Control Number: 1625-0008 AGENCY: Coast Guard, DHS. ACTION..., Office of Management and Budget (OMB), Office of Information and Regulatory Affairs (OIRA), requesting... by Coast Guard docket number [USCG-2010-0978] to the Docket Management Facility (DMF) at the U.S...

76 FR 27074 - Collection of Information Under Review by Office of Management and Budget; OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... Review by Office of Management and Budget; OMB Control Number: 1625-0106 AGENCY: Coast Guard, DHS. ACTION... Office of Management and Budget (OMB), Office of Information and Regulatory Affairs (OIRA), requesting...-0087] to the Docket Management Facility (DMF) at the U.S. Department of Transportation (DOT) and/or to...

76 FR 10385 - Information Collection Request to Office of Management and Budget; OMB Control Number: 1625-0106

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Office of Management and Budget; OMB Control Number: 1625-0106 AGENCY: Coast Guard, DHS. ACTION: Sixty....S. Coast Guard intends to submit an Information Collection Request (ICR) to the Office of Management... Coast Guard docket number [USCG-2011-0087] to the Docket Management Facility (DMF) at the U.S...

76 FR 8764 - Collection of Information Under Review by Office of Management and Budget: OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... Review by Office of Management and Budget: OMB Control Number: 1625-0073 AGENCY: Coast Guard, DHS. ACTION..., Office of Management and Budget (OMB), Office of Information and Regulatory Affairs (OIRA), requesting an... comments identified by Coast Guard docket number [USCG-2010-0981] to the Docket Management Facility (DMF...

76 FR 27073 - Information Collection Request to Office of Management and Budget; OMB Control Number: 1625-0109

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... Office of Management and Budget; OMB Control Number: 1625-0109 AGENCY: Coast Guard, DHS. ACTION: Sixty....S. Coast Guard intends to submit an Information Collection Request (ICR) to the Office of Management...-0158] to the Docket Management Facility (DMF) at the U.S. Department of Transportation (DOT). To avoid...

76 FR 27071 - Collection of Information Under Review by Office of Management and Budget; OMB Control Number...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... Review by Office of Management and Budget; OMB Control Number: 1625-0003 AGENCY: Coast Guard, DHS. ACTION... Office of Management and Budget (OMB), Office of Information and Regulatory Affairs (OIRA), requesting... the Docket Management Facility (DMF) at the U.S. Department of Transportation (DOT) and/or to OIRA. To...

Data Management Facility Operations Plan

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

Keck, Nicole N

2014-06-30

The Data Management Facility (DMF) is the data center that houses several critical Atmospheric Radiation Measurement (ARM) Climate Research Facility services, including first-level data processing for the ARM Mobile Facilities (AMFs), Eastern North Atlantic (ENA), North Slope of Alaska (NSA), Southern Great Plains (SGP), and Tropical Western Pacific (TWP) sites, as well as Value-Added Product (VAP) processing, development systems, and other network services.

Development of a standardized methodology for quantifying total chlorophyll and carotenoids from foliage of hardwood and conifer tree species

Treesearch

Rakesh Minocha; Gabriela Martinez; Benjamin Lyons; Stephanie Long

2009-01-01

Despite the availability of several protocols for the extraction of chlorophylls and carotenoids from foliage of forest trees, information regarding their respective extraction efficiencies is scarce. We compared the efficiencies of acetone, ethanol, dimethyl sulfoxide (DMSO), and N, N-dimethylformamide (DMF) over a range of incubation times for the extraction of...

75 FR 19413 - Information Collection Request to Office of Management and Budget; OMB Control Number: 1625-0089.

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-14

...], please use only one of the following means: (1) Online: http://www.regulations.gov . (2) Mail: Docket..., fax, or delivery to the DMF at the address under ADDRESSES; but please submit them by only one means... particular importance will be statistics on the type of boats used, activities associated with them, boat...

Concise synthesis of the hasubanan alkaloid (±)-cepharatine A using a Suzuki coupling reaction to effect o,p-phenolic coupling.

PubMed

Magnus, Philip; Seipp, Charles

2013-09-20

Suzuki coupling of 10 and 11 resulted in 9, which was O-alkylated to provide 12. Treatment of 12 with CsF in DMF resulted in the formation of the completed core structure 13 in a single step. Reductive amination of 13 completed the synthesis of (±)-cepharatine A, 4.

Kinetic Study of the Heck Reaction: An Interdisciplinary Experiment

ERIC Educational Resources Information Center

Gozzi, Christel; Bouzidi, Naoual

2008-01-01

The aim of this experiment is to study and calculate the kinetic constant of a Heck reaction: the arylation of but-3-en-2-ol by iodobenzene catalyzed by palladium acetate in presence of triethylamine in DMF. The reaction leads to a mixture of two ketones. Students use GC analysis to quantify reagents and products of reaction. They control the…

Evaluation of the Efficacy of a Dental Plaque Control Program in Autistic Patients

ERIC Educational Resources Information Center

Dias, Guilherme G.; Prado, Eliane F. G. B.; Vadasz, Estevao; Siqueira, Jose Tadeu T.

2010-01-01

The aim of this study was to verify the efficacy of a programme for dental plaque control in autistics. Patients were evaluated on five occasions over a period of 180 days using the following instruments: OHI-S, DMF-T, the Fonnes brushing technique and diet questionnaire. Participants were divided into two groups according to level of co-operation…

77 FR 65198 - Generic Drug User Fee-Abbreviated New Drug Application, Prior Approval Supplement, and Drug...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... FY 2013 is 1,160. The FY 2013 application fee is estimated by dividing the number of full application... in FY 2013. Dividing the DMF revenue of $14,940,000 by the estimated number of first-referenced DMFs..., Attention: Government Lockbox 979108, 1005 Convention Plaza, St. Louis, MO 63101. (Note: This U.S. Bank...

Demonstration Training Program for Improving the Capacity of Primary Care Units to Function Within an HMO Setting. Final Report.

ERIC Educational Resources Information Center

Detroit Medical Foundation, MI.

The Demonstration Training Program (DTP) undertaken by the Detroit Medical Foundation (DMF) was designed for Primary Care Unit staffs (PCUs) or Physician Corporations (PCs), area health center providers under contract to the Michigan Health Maintenance Organization Plans, Inc. (MHMOP). The major goals of the program were to design an appropriate…

Photomagnetic Switching of the Complex [Nd(dmf)[subscript 4](H[subscript 2]O)[subscript 3]([mu]-CN)Fe(CN)[subscript 5

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

Svendsen, Helle; Overgaard, Jacob; Chevallier, Marie

2009-10-21

Single-crystal XRD experiments (see picture) reveal the excited-state structure of the photomagnetic heterobimetallic title complex. The system shows a decrease in all the iron-ligand bond lengths, suggesting that photoexcitation involves a ligand-to-metal charge transfer or a change in the superexchange coupling between the metal centers.

Crystal structure of poly[di­aqua­bis­(μ5-benzene-1,3-di­carboxyl­ato)(N,N-di­methyl­formamide)­cadmium(II)disodium(I)

PubMed Central

Sangsawang, Matimon; Chainok, Kittipong; Wannarit, Nanthawat

2017-01-01

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]n or [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaI heterobimetallic coordination polymer. The asymmetric unit consists of one CdII atom, two NaI atoms, two 1,3-bdc ligands, two coordinated water mol­ecules and one coordinated DMF mol­ecule. The CdII atom exhibits a seven-coordinate geometry, while the NaI atoms can be considered to be penta­coordinate. The metal ions and their symmetry-related equivalents are connected via chelating–bridging carboxyl­ate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H⋯O hydrogen bonds involving the coordinated water mol­ecules and the 1,3-bdc carboxyl­ate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks. PMID:29152332

Synthesis, crystal structure and third-order non-linear optical property of heterobimetallic cluster compound [MoOICu 3S 3(2,2'-bipy) 2

NASA Astrophysics Data System (ADS)

Li, Yong; Lu, Jing; Xu, Jiqing; Cui, Xiaobing; Sun, Yinghua; Yang, Qingxin; Pan, Lingyun

2004-03-01

Nest-shaped cluster [MoOICu 3S 3(2,2'-bipy) 2] ( 1) was synthesized by the treatment of (NH 4) 2MoS 4, CuI, ( n-Bu) 4NI, and 2,2'-bipyridine (2,2'-bipy) through a solid-state reaction. It crystallizes in monoclinic space group P2 1/ n, a=9.591(2) Å, b=14.820(3) Å, c=17.951(4) Å, β=91.98(2)°, V=2549.9(10) Å3, and Z=4. The nest-shaped cluster was obtained for the first time with a neutral skeleton containing 2,2'-bipy ligand. The non-linear optical (NLO) property of [MoOICu 3S 3(2,2'-bipy) 2] in DMF solution was measured by using a Z-scan technique with 15 ns and 532 nm laser pulses. The cluster has large third-order NLO absorption and the third-order NLO refraction, its α2 and n2 values were calculated as 6.2×10 -10 and -3.8×10 -17 m 2 W -1 in a 3.7×10 -4 M DMF solution.

High Conductivity, High Strength Solid Electrolytes Formed by in Situ Encapsulation of Ionic Liquids in Nanofibrillar Methyl Cellulose Networks.

PubMed

Mantravadi, Ramya; Chinnam, Parameswara Rao; Dikin, Dmitriy A; Wunder, Stephanie L

2016-06-01

Strong, solid polymer electrolyte ion gels, with moduli in the MPa range, a capacitance of 2 μF/cm(2), and high ambient ionic conductivities (>1 × 10(-3) S/cm), all at room temperature, have been prepared from butyl-N-methyl pyrrolidinium bis(trifluoromethylsulfonyl) imide (PYR14TFSI) and methyl cellulose (MC). These properties are particularly attractive for supercapacitor applications. The ion gels are prepared by codissolution of PYR14TFSI and MC in N,N-dimethylformamide (DMF), which after heating and subsequent cooling form a gel. Evaporation of DMF leave thin, flexible, self-standing ion gels with up to 97 wt % PYR14TFSI, which have the highest combined moduli and ionic conductivity of ion gels to date, with an excellent electrochemical stability window (5.6 V). These favorable properties are attributed to the immiscibility of PYR14TFSI in MC, which permits the ionic conductivity to be independent of the MC at low MC content, and the in situ formation of a volume spanning network of semicrystalline MC nanofibers, which have a high glass transition temperature (Tg = 190 °C) and remain crystalline until they degrade at 300 °C.

Purification of aflatoxin B1 antibody for the development of aflatoxin biosensor

NASA Astrophysics Data System (ADS)

Prihantoro, E. A. B.; Saepudin, E.; Ivandini, T. A.

2017-07-01

Aflatoxin B1 (AFB1) is produced from agricultural products especially peanuts overgrown with aspergillus flavus during the post-harvest process. Aflatoxin is classified as a highly toxic and carcinogenic substance to humans by the International Agency for Research on Cancer (IARC), WHO. This research was conducted to develop the AFB1 biosensor using antibody that specifically binds to aflatoxin B1. This antibody was produced by injecting an AFB1 hapten-protein (immunogen) to a rabbit. Antibody was obtained from rabbit's blood serum and purified using Protein A affinity chromatography and precipitation at the isoelectric point. The result showed that purification using protein A contains antibody of 4.0 mg/mL, whereas purification using precipitation at isoelectric pH contains antibody of 0.3 mg/mL. The pure antibody was tested for its specificity against AFB1, tetrahydrofuran (THF), dimethyl formamide (DMF), bovine serum albumin (BSA), and ethanol. The result revealed that THF, BSA, and ethanol were bound to antibody, while DMF showed no interaction. It was concluded that the polyclonal antibody which have been successfully purified from rabbit's blood serum using protein A affinity chromatography and precipitation methods showed an unspecific identification.

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

Lloyd, R.D.; Gren, D.C.; Simon, S.L.

External gamma-ray exposures from fallout originating at the Nevada Test Site (NTS) have been assigned to 6,507 individual subjects (1,177 leukemia cases and 5,330 control subjects) who died as Utah residents between 1952 and 1981. Leukemia cases were identified, confirmed, and classified by cell type from the Utah Cancer Registry, Utah State vital records, and medical records. Residential histories were obtained from the Deceased Membership File (DMF) of the Church of Jesus Christ of Latter-day Saints (LDS), supplemented by information from the LDS Church Census Records that were taken in 1950, 1955, and 1960-62. Control subjects were selected randomly withinmore » age strata from the DMF and were frequency-matched to the cases by age at death and for sex. Individual radiation exposures were assigned as a function of residence location and time interval for each residence during the fallout period (1951-1958) using geographic exposure data taken from the literature. Temporal distribution of exposure for subjects who resided in more than one locality or who were born or died during the fallout period was determined from data of other investigators. Calculated gamma-ray exposures for each place of residence were summed for each subject to yield the exposure to fallout from the NTS.« less

Metal-organic frameworks based on rigid ligands as separator membranes in supercapacitor.

PubMed

Meng, Jiang-Ping; Gong, Yun; Lin, Qiang; Zhang, Miao-Miao; Zhang, Pan; Shi, Hui-Fang; Lin, Jian-Hua

2015-03-28

Two thermally stable MOFs formulated as CoL(1,4-bdc)·2DMF (L = 3,5-bis(5-(pyridin-4-yl)-4H-1,2,4-triazol-3-yl)pyridine), 1,4-H2bdc = 1,4-benzenedicarboxylic acid) (1) and CdL(4,4'-bpc)·3DMF (4,4'-H2bpc = 4,4'-biphenyldicarboxylic acid) (2) have been solvothermally synthesized and exhibit a similar uninodal 6-connected 3D architecture with {4(12)·6(3)}-pcu topology. MOF1 shows a non-interpenetrated network with larger channel, whereas MOF 2 exhibits a 3-fold interpenetrating framework with smaller pore size. When the two MOFs are used as separator membranes in a supercapacitor, the equivalent series resistance (Res) is larger than the Res in the blank supercapacitor, and the smaller the current density, the more the Res. After being charged and discharged at the low current density, the supercapacitor with MOF 1 as separator membrane (denoted as 1a) possesses a much larger specific capacitance (SC) than the blank supercapacitor, and the amorphous separator membrane 1a shows a more porous morphology than the original MOF membrane 1.

A novel polyhedron-based metal-organic framework with high performance for gas uptake and light hydrocarbon separation.

PubMed

Sun, Qiushi; Yao, Shuo; Liu, Bing; Liu, Xinyao; Li, Guanghua; Liu, Xiaoyang; Liu, Yunling

2018-04-03

A novel polyhedron-based metal-organic framework [(CH3)2NH2]2[Zn3(TADIPA)2(DMF)2]·4DMF (JLU-Liu40), which possesses three types of cages with different shapes and sizes, has been successfully synthesized. The framework of JLU-Liu40 is constructed by two inorganic secondary building units (SBUs) of 4-connected square binuclear Zn-paddlewheel and 4-connected tetrahedron mononuclear Zn unit and one organic SBU, which has abundant Lewis basic sites (LBSs), and the framework can be simplified as a pair of 3-connected triangle geometries. Moreover, JLU-Liu40 shows a new (3, 4, 4)-connected topology with the Schläfli symbol {72, 9}2{74, 82}. With the benefit of its high density of open metal sites (OMSs) and LBSs, JLU-Liu40 shows good adsorption ability for some small gases such as N2, CO2, CH4, C2H6 and C3H8. In addition, the theoretical ideal adsorbed solution theory (IAST) calculation indicates that JLU-Liu40 should be a promising material for light gas separation.

Encapsulation of Ln(III) Ions/Dyes within a Microporous Anionic MOF by Post-synthetic Ionic Exchange Serving as a Ln(III) Ion Probe and Two-Color Luminescent Sensors.

PubMed

Zhao, Shu-Na; Song, Xue-Zhi; Zhu, Min; Meng, Xing; Wu, Lan-Lan; Feng, Jing; Song, Shu-Yan; Zhang, Hong-Jie

2015-06-26

A new anionic framework {[Me2NH2]0.125[In0.125(H2L)0.25]⋅xDMF}n (1) with one-dimensional (1D) channels along the c axis of about 13.06×13.06 Å(2), was solvothermally synthesized and well characterized. Post-synthetic cation exchange of 1 with Eu(3+), Tb(3+), Dy(3+), Sm(3+) afforded lanthanide(III)-loaded materials, Ln(3+)@1, with different luminescent behavior, indicating that compound 1 could be used as a potential luminescent probe toward different lanthanide(III) ions. Additionally, compound 1 exhibits selective adsorption ability toward cationic dyes. Moreover, the RhB@1 realized the probing of different organic solvent molecules by tuning the energy transfer efficiency between two different emissions, especially for sensing DMF. This work highlights the practical application of luminescent guest@MOFs as sensors, and it paves the way toward other one/multi-color luminescent host-guest systems by rational selection of MOF hosts and guest chromophores with suitable emissive colors and energy levels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, structure, photoluminescence and antitumour activity of zinc complex based on 2-(2-(1H-benzo-[d]imidazol-2-yl)benzyl)-1H-benzo-[d]imidazole

NASA Astrophysics Data System (ADS)

Che, Zhijian; Wang, Shaoxiang; Liu, Shenggui; Li, Guobi; Wu, Qiting; Lin, Chunyu; Kong, Linglang; Wang, Sheng

2015-01-01

A new complex [Zn(bbb)Cl2]·DMF, where bbb is 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole, was synthesized and characterized by element analysis, 1H NMR and X-ray single crystal structure analyses. For complex: crystal system, triclinic, space group, P-1, a = 9.4661(13), b = 10.3534(14), c = 13.0025(18) Å, α = 73.477(2), β = 80.743(2), γ = 88.658(2)°, V = 1205.5(3) Å3, Z = 2. In this complex, the Zn2+ distorted tetrahedron geometry is coordinated by two nitrogen atoms from 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole and two Cl-. The complex emits yellow green luminescence with the maximal emission peak at 550 nm in DMF solution. The complex exhibits inhibition on the growth of Eca109 cancer cell with IC50 value of 8.9 ± 1.1 μM, which was lower than that of cisplatin (14.3 ± 1.4 μM). This complex has potential application in treatment of esophageal cancer.

Effect of chain structure on hydrogen bonding in vinyl acetate - vinyl alcohol copolymers

NASA Astrophysics Data System (ADS)

Merekalova, Nadezhda D.; Bondarenko, Galina N.; Denisova, Yuliya I.; Krentsel, Liya B.; Litmanovich, Arkadiy D.; Kudryavtsev, Yaroslav V.

2017-04-01

FTIR spectroscopy and semi-empirical AM1 method are used to study hydrogen bonding in multiblock and random equimolar copolymers of vinyl acetate and vinyl alcohol. An energetically beneficial zip-holder complex, built on multiple inter- and intrachain hydroxyl-hydroxyl bonds and an intrachain hydroxyl-acetyloxy bond, can be formed between two vinyl alcohol sequences. As a result, multiblock copolymers reveal stronger degree of association that affects crystallinity, as well as various rheological and relaxation properties discussed in the literature. Macromolecular complexes in random copolymers are weak and tend to be destroyed in the presence of residual DMF solvent and adsorbed water. Nevertheless, a rather stable interchain quaternary complex can be formed that includes vinyl alcohol and vinyl acetate units and DMF and water molecules. For a single chain it is shown that an H-bond between neighboring vinyl alcohol and vinyl acetate monomer units mostly engages a carbonyl oxygen atom of the vinyl acetate, if the vinyl alcohol belongs to a short (<5 units) sequence, and an ether oxygen atom in the other case. On the whole, the quantum chemistry calculations shed much light on the origin of distinctions in the copolymer FTIR spectra, which may seem subtle when considered standalone.

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

Meng, Jiang Ping; Yan, Zhi Shuo; Long, Ji Ying

By using a rigid dicarboxylate ligand, 4,5-di(4′-carboxylphenyl)benzene (H{sub 2}L), two complexes formulated as SrL(DMF)(H{sub 2}O)·(CH{sub 3}CN) (DMF=N,N′-dimethylformamide) (1) and BaL(H{sub 2}O){sub 2} (2) were solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1 and 2 display two-dimensional (2D) layer structures. The two complexes exhibit different electrochemical and photoelectrochemical properties. Their thermal stabilities, cyclic voltammograms, UV–vis absorption and diffuse reflectance spectra and photoluminescence properties have been investigated. The band structures, the total density of states (TDOS) and partial density of states (PDOS) of the two complexes were calculated by CASTEP program. Complex 2 exhibits much higher photocurrent density thanmore » complex 1. The Mott–Schottky plots reveal that complexes 1 and 2 both are p-type semiconductors, which are in agreement with their band structure calculations. - Graphical abstract: Two alkaline earth metal(II) complexes with 2D layer structures are p-type semiconductors, they possess different band structures and density of states. And the Ba(II) complex 2 exhibits much higher photocurrent density than the Sr(II) complex 1.« less

Design of geometry, synthesis, spectroscopic (FT-IR, UV/Vis, excited state, polarization) and anisotropy (thermal conductivity and electrical) properties of new synthesized derivatives of (E,E)-azomethines in colored stretched poly (vinyl alcohol) matrix

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Sheikhi, Masoome; Filippovich, Liudmila; Dikusar, Evgenij; Yahyaei, Hooriye; Kumar, Rakesh; Khaleghian, Mehrnoosh

2018-04-01

In the present work, the molecular structures of two new azomethine dyes: have been predicted and investigated using Density Functional Theory (DFT) in dimethylformamide (DMF). The geometries of the azomethine dyes were optimized by B3LYP/6-31+G* level of theory. The electronic spectra of these azomethine dyes in a DMF solvent was carried out by using TD-B3LYP/6-31+G* method. After quantum-chemical calculations two new azomethine dyes for optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. The computed absorption spectral data of the azomethine dyes are in good agreement with the experimental data, thus allowing an assignment of the UV/Vis spectra. On the basis of polyvinyl alcohol (PVA) and the new synthesized azomethine dyes polarizing films for visible region of spectrum were developed. The main optical parameters of the polarizing PVA-films (Transmittance, Polarization Efficiency and Dichroic Ratio) have been measured and discussed. Anisotropy of thermal and electrical conductivity of the PVA-films have been studied and explained.

MYCN drives glutaminolysis in neuroblastoma and confers sensitivity to an ROS augmenting agent.

PubMed

Wang, Tingting; Liu, Lingling; Chen, Xuyong; Shen, Yuqing; Lian, Gaojian; Shah, Nilay; Davidoff, Andrew M; Yang, Jun; Wang, Ruoning

2018-02-14

Heightened aerobic glycolysis and glutaminolysis are characteristic metabolic phenotypes in cancer cells. Neuroblastoma (NBL), a devastating pediatric cancer, is featured by frequent genomic amplification of MYCN, a member of the Myc oncogene family that is primarily expressed in the early stage of embryonic development and required for neural crest development. Here we report that an enriched glutaminolysis gene signature is associated with MYCN amplification in children with NBL. The partial knockdown of MYCN suppresses glutaminolysis in NBL cells. Conversely, forced overexpression of MYCN in neural crest progenitor cells enhances glutaminolysis. Importantly, glutaminolysis induces oxidative stress by producing reactive oxygen species (ROS), rendering NBL cells sensitive to ROS augmentation. Through a small-scale metabolic-modulator screening, we have found that dimethyl fumarate (DMF), a Food and Drug Administration-approved drug for multiple sclerosis, suppresses NBL cell proliferation in vitro and tumor growth in vivo. DMF suppresses NBL cell proliferation through inducing ROS and subsequently suppressing MYCN expression, which is rescued by an ROS scavenger. Our findings suggest that the metabolic modulation and ROS augmentation could be used as novel strategies in treating NBL and other MYC-driven cancers.

Four unprecedented cobalt(II) and cadmium(II) metal-organic frameworks based on a rigid tricarboxylate ligand: Synthesis, crystal structures, magnetic and fluorescence properties

NASA Astrophysics Data System (ADS)

Liu, Yaru; Liu, Lan; Zhang, Xiao; Wu, Jie

2018-03-01

A Co(II) MOF {[Co3(L)2(H2O)4](DMF)2}n (1) and three Cd(II) MOFs [Cd3(L)2(H2O)7]n (2), [Cd3(L)2(H2O)11]n (3) and [Cd3(L)2(DMF)2(H2O)]n (4) are synthesized based on the promising multifunctional tricarboxylate ligand 6-(3, 5-dicarboxyl phenyl) nicotinic acid (H3L). 1 exhibits a 3D framework with 1D channels which contains opposite-handedness helical chains based on the trinuclear Co(II) clusters. 2-4 are obtained depend on different reaction conditions. 2 displays a 3D framework, which is composed of two kinds of 2D layers linked with each other. 3 shows a rare tongue-and-groove-type bilayer structure. And 4 is an interesting 3D framework containing infinite 1D inorganic Cdsbnd Osbnd Cd chains. In these MOFs, the H3L ligand shows the versatile coordination modes and strong coordination ability. Furthermore, the magnetic and solid-state luminescent properties of the MOFs have been investigated.

Synthesis, characterization and electrochemical investigations of mixed-ligand copper(II)-organic supramolecular frameworks

NASA Astrophysics Data System (ADS)

Singh, Sandeep K.; Srivastava, Ashish Kumar; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish

2017-11-01

Two mixed-ligand copper(II)-organic coordination compounds with 5,5‧-dimethyl-2,2‧-bipyridine (5,5‧-Me2bpy) as a primary ligand while aliphatic malonate (Hmal) and aromatic 2-hydroxynicotinate (2-OHNA) as secondary ligands, were synthesized. These complexes are formulated as: [Cu(Hmal)(5,5‧-Me2bpy)(H2O)](ClO4) 1 and [Cu2(2-OHNA)2(5,5‧-Me2bpy)2(NO3)](NO3) 2. These two complexes were structurally characterized by single crystal X-ray diffraction analysis. Characterization was further supported by powder X-ray diffraction analysis, elemental analyses, FT-IR, FAB-MASS and TGA, DSC studies. Cyclic voltammetric and UV-visible spectral studies of these two complexes have also been done. The electrochemical studies of complex 1 in DMSO and DMF have shown that this complex undergoes quasi-reversible diffusion-controlled one-electron transfer reaction without any chemical complication while complex 2 in DMSO undergoes quasi-reversible diffusion-controlled one electron transfer reaction, following EC mechanism. The electrochemical behaviour of complex 2 in DMF is complicated probably due to presence of more than one species in solution phase.

Processing ARM VAP data on an AWS cluster

NASA Astrophysics Data System (ADS)

Martin, T.; Macduff, M.; Shippert, T.

2017-12-01

The Atmospheric Radiation Measurement (ARM) Data Management Facility (DMF) manages over 18,000 processes and 1.3 TB of data each day. This includes many Value Added Products (VAPs) that make use of multiple instruments to produce the derived products that are scientifically relevant. A thermodynamic and cloud profile VAP is being developed to provide input to the ARM Large-eddy simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project (https://www.arm.gov/capabilities/vaps/lasso-122) . This algorithm is CPU intensive and the processing requirements exceeded the available DMF computing capacity. Amazon Web Service (AWS) along with CfnCluster was investigated to see how it would perform. This cluster environment is cost effective and scales dynamically based on demand. We were able to take advantage of autoscaling which allowed the cluster to grow and shrink based on the size of the processing queue. We also were able to take advantage of the Amazon Web Services spot market to further reduce the cost. Our test was very successful and found that cloud resources can be used to efficiently and effectively process time series data. This poster will present the resources and methodology used to successfully run the algorithm.

Optical nonlinearity of D-A-π-D and D-A-π-A type of new chalcones for potential applications in optical limiting and density functional theory studies

NASA Astrophysics Data System (ADS)

Chandra Shekhara Shetty, T.; Chidan Kumar, C. S.; Gagan Patel, K. N.; Chia, Tze Shyang; Dharmaprakash, S. M.; Ramasami, Ponnadurai; Umar, Yunusa; Chandraju, Siddegowda; Quah, Ching Kheng

2017-09-01

Two new chalcones namely, (2E)-1-(3-fluoro-4-methoxyphenyl)-3-(4-methoxyphenyl) prop-2-en-1-one and (2E)-3-(4-chlorophenyl)-1-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one were synthesized and grown as single crystals by slow evaporation technique in methanol. The FTIR spectrum recorded confirms the presence of functional groups in these materials. The molecular conformation of the compounds was achieved by single crystal X-ray diffraction studies. The thermal stability of the crystals was determined from TGA/DSC curve. The third order optical nonlinearity of the chalcone compounds in DMF solution has been carried out using an Nd:YAG laser at 532 nm as the source of excitation. The nonlinear optical response was characterized by measuring the intensity dependent refractive index n2 of the medium using Z-scan technique. It is seen that the molecules exhibit a negative (defocusing) nonlinearity and large nonlinear refractive index of the order of -1.8 × 10-11 esu. The third-order nonlinearity of the studied chalcones is dominated by nonlinear refraction, which leads to strong optical limiting of laser. The result reveals that these two new chalcone molecules would be a promising material for optical limiting applications. In addition, the optimized molecular geometry, vibrational frequencies in gas, and the Molecular Electrostatic Potential (MEP) surface parameters of the two molecules were calculated using DFT/B3LYP method with 6-311++G(d,p) basis set in ground state. All the theoretical calculations were found in good agreement with experimental data.

Solvatochromism and preferential solvation of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone by UV-vis absorption and laser-induced fluorescence measurements

NASA Astrophysics Data System (ADS)

Sasirekha, V.; Vanelle, P.; Terme, T.; Ramakrishnan, V.

2008-12-01

Solvation characteristics of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone ( 1) in pure and binary solvent mixtures have been studied by UV-vis absorption spectroscopy and laser-induced fluorescence techniques. The binary solvent mixtures used as CCl 4 (tetrachloromethane)-DMF ( N, N-dimethylformamide), AN (acetonitrile)-DMSO (dimethylsulfoxide), CHCl 3 (chloroform)-DMSO, CHCl 3-MeOH (methanol), and MeOH-DMSO. The longest wavelength band of 1 has been studied in pure solvents as well as in binary solvent mixtures as a function of the bulk mole fraction. The Vis absorption band maxima show an unusual blue shift with increasing solvent polarity. The emission maxima of 1 show changes with varying the pure solvents and the composition in the case of binary solvent mixtures. Non-ideal solvation characteristics are observed in all binary solvent mixtures. It has been observed that the quantity [ ν-(Xν+Xν)] serves as a measure of the extent of preferential solvation, where ν˜ and X are the position of band maximum in wavenumbers (cm -1) and the bulk mole fraction values, respectively. The preferential solvation parameters local mole fraction ( X2L), solvation index ( δs2), and exchange constant ( k12) are evaluated.

[Do they have to fluoridate water for public usage?].

PubMed

Vargas Marcos, F; Robledo de Dios, T

1993-01-01

In order to facilitate the convenience of fluorating or not the public use waters, a bibliographic review about the positive or negative aspects of this public health measure has been made. The different epidemiologic surveys about dental health conditions in our country, since 1969 till the present time, have been reviewed. From the analysis of these works, it can be deduced that the degree of caries severity index (DMF) is situated at a moderate to low level, according to the classification of the World Health Organization. The advantages, inconvenience, cost and percentage of caries reduction of the different methods to prevent dental caries are studied. It is considered positive to go on with the policy of public use waters fluoration, provided that is is based on a series of prerequisites which guarantee the highest level of effectiveness and efficiency. Among the different objective criteria to fluorate waters, the following ones stand out: a high prevalence of caries, a good system of waters out: a high prevalence of caries, a good system of waters diffusion, a natural fluor concentration lower than 0.7 grams/litre, the cost-benefit analysis, the population size. The elaboration of studies to determine the total quantity of fluorides, ingested by the population from various sources, is recommended.

Cost-utility of First-line Disease-modifying Treatments for Relapsing-Remitting Multiple Sclerosis.

PubMed

Soini, Erkki; Joutseno, Jaana; Sumelahti, Marja-Liisa

2017-03-01

This study evaluated the cost-effectiveness of first-line treatments of relapsing-remitting multiple sclerosis (RRMS) (dimethyl fumarate [DMF] 240 mg PO BID, teriflunomide 14 mg once daily, glatiramer acetate 20 mg SC once daily, interferon [IFN]-β1a 44 µg TIW, IFN-β1b 250 µg EOD, and IFN-β1a 30 µg IM QW) and best supportive care (BSC) in the health care payer setting in Finland. The primary outcome was the modeled incremental cost-effectiveness ratio (ICER; €/quality-adjusted life-year [QALY] gained, 3%/y discounting). Markov cohort modeling with a 15-year time horizon was employed. During each 1-year modeling cycle, patients either maintained the Expanded Disability Status Scale (EDSS) score or experienced progression, developed secondary progressive MS (SPMS) or showed EDSS progression in SPMS, experienced relapse with/without hospitalization, experienced an adverse event (AE), or died. Patients׳ characteristics, RRMS progression probabilities, and standardized mortality ratios were derived from a registry of patients with MS in Finland. A mixed-treatment comparison (MTC) informed the treatment effects. Finnish EuroQol Five-Dimensional Questionnaire, Three-Level Version quality-of-life and direct-cost estimates associated with EDSS scores, relapses, and AEs were applied. Four approaches were used to assess the outcomes: cost-effectiveness plane and efficiency frontiers (relative value of efficient treatments); cost-effectiveness acceptability frontier, which demonstrated optimal treatment to maximize net benefit; Bayesian treatment ranking (BTR); and an impact investment assessment (IIA; a cost-benefit assessment), which increased the clinical interpretation and appeal of modeled outcomes in terms of absolute benefit gained with fixed drug-related budget. Robustness of results was tested extensively with sensitivity analyses. Based on the modeled results, teriflunomide was less costly, with greater QALYs, versus glatiramer acetate and the IFNs. Teriflunomide had the lowest ICER (24,081) versus BSC. DMF brought marginally more QALYs (0.089) than did teriflunomide, with greater costs over the 15 years. The ICER for DMF versus teriflunomide was 75,431. Teriflunomide had >50% cost-effectiveness probabilities with a willingness-to-pay threshold of <€77,416/QALY gained. According to BTR, teriflunomide was first-best among the disease-modifying therapies, with potential willingness-to-pay thresholds of up to €68,000/QALY gained. In the IIA, teriflunomide was associated with the longest incremental quality-adjusted survival and time without cane use. Generally, primary outcomes results were robust, based on the sensitivity analyses. The results were sensitive only to large changes in analysis perspective or mixed-treatment comparison. The results were sensitive only to large changes in analysis perspective or MTC. Based on the analyses, teriflunomide was cost-effective versus BSC or DMF with the common threshold values, was dominant versus other first-line RRMS treatments, and provided the greatest impact on investment. Teriflunomide is potentially the most cost-effective option among first-line treatments of RRMS in Finland. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Mild and efficient molybdenum-mediated Pauson-Khand-type reaction.

PubMed

Adrio, Javier; Rivero, Marta Rodríguez; Carretero, Juan Carlos

2005-02-03

[reaction: see text] The molybdenum-mediated Pauson-Khand reaction promoted by Mo(CO)3(DMF)3 takes place under very mild conditions in the absence of any promoter. High yields in Pauson-Khand adducts are obtained in the cyclization of a wide variety of functionalized 1,6- and 1,7-enynes. Enynes bearing electron withdrawing groups at the alkene terminus are particularly good substrates.

Synthesis, characterization, crystal structure, superoxide dismutase and biological activities of nickel (II) complexes with bidentate ligands possessing N and O donor atoms

NASA Astrophysics Data System (ADS)

Sangeeta, S.; Ahmad, K.; Noorussabah, N.; Bharti, S.; Mishra, M. K.; Sharma, S. R.; Choudhary, M.

2017-12-01

Two new Schiff bases 2-((E)-(4-bromo-2-chlorophenylimino)methyl)-4-bromophenol(HL1) and1-((E)-(4-bromo-2-chlorophenylimino)methyl)naphthalene-2-ol (HL2) and their new nickel (II) complexes [Ni(L1)2]·DMF(1) and [Ni(L2)2] (2) have been synthesized and characterized by various physico- chemical and spectroscopic methods. The solid-state structures of synthesized compounds were determined by single crystal X-ray crystallography, which revealed square planar geometry around Ni (II) ion. Infrared spectra, UV-Vis, thermal analysis and magnetic susceptibility measurements agreed with the observed crystal structures. The ligand (HL1) crystallized in the Orthorhombic system of the space group Pbca,a = 7.5485(4)Å, b = 11.5514(5) Å, c = 30.1370(14)Å, α = 90°, β = 90°, γ = 90°and Z = 8. Complex[Ni(L1)2]·DMF(1) crystallized in the Triclinic system of the space group P-1, a = 8.9954(3) Å, b = 9.4593(4) Å, c = 13.2657(5) Å, α = 101.478°, β = 99.595°, γ = 117.651°and Z = 2, whereas complex [Ni(L2)2]·(2) crystallized in the Monoclinic system of the space group P21/c, a = 9.301(9)Å, b = 12.149(8)Å, c = 13.792(10)Å, α = 90°, β = 106.35(4).°, γ = 90°and Z = 2. The Schiff bases (HL1and HL2) behaved as monobasic bidentate ligands possessing N and O donor atoms. The SOD activities of HL1 and its Ni (II) complex[Ni(L1)2]·DMF(1) have been measured using xanthine-xanthine oxidase as a source of superoxide radical and NBT assay as O2- scavenger. In vitro antimicrobial activities of the Ni(II) complexes (1) and (2)against Bacillus cereus and Staphylococcus aureus as Gram + ve and Salmonella typhi, Klebsiella pneumonia and Escherichia coli as Gram-ve species have been investigated comparing with the Schiff base ligands (HL1and HL2).

Role of dimethyl fumarate in oxidative stress of multiple sclerosis: A review.

PubMed

Suneetha, A; Raja Rajeswari, K

2016-04-15

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS affecting both white and grey matter. Inflammation and oxidative stress are also thought to promote tissue damage in multiple sclerosis. Recent data point at an important role of anti-oxidative pathways for tissue protection in chronic MS, particularly involving the transcription factor nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2). Thus, novel therapeutics enhancing cellular resistance to free radicals could prove useful for MS treatment. Oxidative stress and anti-oxidative pathways are important players in MS pathophysiology and constitute a promising target for future MS therapy with dimethyl fumarate. The clinical utility of DMF in multiple sclerosis is being explored through phase III trials with BG-12, which is an oral therapeutic agent. Currently a wide research is going on to find out the exact mechanism of DMF, till date it is not clear. Based on strong signals of nephrotoxicity in non-humans and the theoretical risk of renal cell cancer from intracellular accumulation of fumarate, post-marketing study of a large population of patients will be necessary to fully assess the long-term safety of dimethyl fumarate. The current treatment goals are to shorten the duration and severity of relapses, prolong the time between relapses, and delay progression of disability. In this regard, dimethyl fumarate offers a promising alternative to orally administered fingolimod (GILENYA) or teriflunomide (AUBAGIO), which are currently marketed in the United States under FDA-mandated Risk Evaluation and Mitigation Strategy (REMS) programs because of serious safety concerns. More clinical experience with all three agents will be necessary to differentiate the tolerability of long-term therapy for patients diagnosed with multiple sclerosis. This write-up provides the detailed information of dimethyl fumarate in treating the neuro disease, multiple sclerosis and its mechanism involved via oxidative stress pathway. The rapid screening methods are also need to be developed to estimate DMF in biological samples to perform and proceed for further investigations. Copyright © 2016 Elsevier B.V. All rights reserved.

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

PubMed Central

Moreira, Guillaume; Charles, Laurence; Major, Mohamed; Vacandio, Florence; Guillaneuf, Yohann

2013-01-01

Summary The range of applications of cellulose, a glucose-based polysaccharide, is limited by its inherently poor mechanical properties. The grafting of synthetic polymer chains by, for example, a “grafting from” process may provide the means to broaden the range of applications. The nitroxide-mediated polymerization (NMP) method is a technique of choice to control the length, the composition and the architecture of the grafted copolymers. Nevertheless, cellulose is difficult to solubilize in organic media because of inter- and intramolecular hydrogen bonds. One possibility to circumvent this limitation is to solubilize cellulose in N,N-dimethylformamide (DMF) or N,N-dimethylacetamide (DMA) with 5 to 10 wt % of lithium salts (LiCl or LiBr), and carry out grafted polymerization in this medium. The stability of nitroxides such as SG1 has not been studied under these conditions yet, even though these parameters are of crucial importance to perform the graft modification of polysaccharide by NMP. The aim of this work is to offer a model study of the stability of the SG1 nitroxide in organic media in the presence of unprotected glucose or cellobiose (used as a model of cellulose) and in the presence of lithium salts (LiBr or LiCl) in DMF or DMA. Contrary to TEMPO, SG1 proved to be stable in the presence of unprotected sugar, even with an excess of 100 molar equivalents of glucose. On the other hand, lithium salts in DMF or DMA clearly degrade SG1 nitroxide as proven by electron-spin resonance measurements. The instability of SG1 in these lithium-containing solvents may be explained by the acidification of the medium by the hydrolysis of DMA in the presence of LiCl. This, in turn, enables the disproportionation of the SG1 nitroxide into an unstable hydroxylamine and an oxoammonium ion. Once the conditions to perform an SG1-based nitroxide-mediated graft polymerization from cellobiose have been established, the next stage of this work will be the modification of cellulose and cellulose derivatives by NMP. PMID:23946859

Health risk assessment of volatile organic compounds exposure near Daegu dyeing industrial complex in South Korea.

PubMed

Shuai, Jianfei; Kim, Sunshin; Ryu, Hyeonsu; Park, Jinhyeon; Lee, Chae Kwan; Kim, Geun-Bae; Ultra, Venecio U; Yang, Wonho

2018-04-20

Studying human health in areas with industrial contamination is a serious and complex issue. In recent years, attention has increasingly focused on the health implications of large industrial complexes. A variety of potential toxic chemicals have been produced during manufacturing processes and activities in industrial complexes in South Korea. A large number of dyeing industries gathered together in Daegu dyeing industrial complex. The residents near the industrial complex could be often exposed to volatile organic compounds. This study aimed to evaluate VOCs levels in the ambient air of DDIC, to assess the impact on human health risks, and to find more convincing evidences to prove these VOCs emitted from DDIC. According to deterministic risk assessment, inhalation was the most important route. Residential indoor, outdoor and personal exposure air VOCs were measured by passive samplers in exposed area and controlled area in different seasons. Satisfaction with ambient environments and self-reported diseases were also obtained by questionnaire survey. The VOCs concentrations in exposed area and controlled area was compared by t-test. The relationships among every VOC were tested by correlation. The values of hazard quotient (HQ) and life cancer risk were estimated. The concentrations of measured VOCs were presented, moreover, the variety of concentrations according the distances from the residential settings to the industrial complex site in exposed area. The residential indoor, outdoor, and personal exposure concentrations of toluene, DMF and chloroform in exposed area were significantly higher than the corresponding concentrations in controlled area both in summer and autumn. Toluene, DMF, chloroform and MEK had significantly positive correlations with each other in indoor and outdoor, and even in personal exposure. The HQ for DMF exceeded 1, and the life cancer risk of chloroform was greater than 10 - 4 in exposed area. The prevalence of respiratory diseases, anaphylactic diseases and cardiovascular diseases in exposed area were significantly higher than in controlled area. This study showed that adverse cancer and non-cancer health effects may occur by VOCs emitted from DDIC, and some risk managements are needed. Moreover, this study provides a convenient preliminarily method for pollutants source characteristics.

Tuning the Formations of Metal-Organic Frameworks by Modification of Ratio of Reactant, Acidity of Reaction System, and Use of a Secondary Ligand

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

Gao, Q; Xie, YB; Li, JR

2012-01-01

Four porous coordination networks (PCNs), {[Zn3O(H2O)(3)(adc)(3)]center dot 2(C2H6NH2)center dot 2(DMF)center dot 3(H2O)}(n) (PCN-131), Zn-2(DMA)(2)(adc)(2)]center dot 2(DMA)}(n) (PCN-132), {[Zn3O(DMF)(adc)(3)(4,4'-bpy)]center dot 2(C2H6NH2)center dot S}(n) (PCN-131'), and {[Zn(adc)(4,4'-bpy)(0.5)]center dot S}(n) (PCN-132'), have been synthesized by the assembly of anthrancene-9,10-dicarboxylic acid (H(2)adc) with Zn(II) under different reaction conditions, including modifications of reactant ratio, acidity variations, and the use of a secondary ligand. Single-crystal X-ray diffraction studies reveal that PCN-131, obtained from the dimethylformamide (DMF) solution under acid condition, has a three-dimentional (3D) framework structure with one-dimensional (1D) honeycomb channels. PCN-132 isolated from dimethylacetamide (DMA) solution without adding acid in synthesis is a two-dimensional (2D)more » layer compound. By employing 4,4'-bipyridyl (4,4'-bpy) as a secondary ligand, PCN-131' and PCN-132' were synchronously synthesized as a mixture outcome with more PCN-131' than PCN-132'. In PCN-131', 4,4'-bpy acting as a secondary ligand is arranged inside the honeycomb channel of the 3D PCN-131, resulting in an effective improvement of thermal stability of the network, while in PCN-132', 4,4'-bpy ligands link 2D layers of PCN-132 to form a pillared-layer 3D framework Gas adsorption has been performed for selected materials. The results show that the framework of PCN-131 is thermally unstable after removing the solvent molecules coordinated to their metal sites. While PCN-131' is stable for gas uptake, with an evaluated Langmuir surface area of 199.04 m(2) g(-1), it shows a selective adsorption of CO2 over CH4.« less

In Vitro Antitumor Active Gold(I) Triphenylphosphane Complexes Containing 7-Azaindoles

PubMed Central

Štarha, Pavel; Trávníček, Zdeněk; Drahoš, Bohuslav; Dvořák, Zdeněk

2016-01-01

A series of gold(I) complexes of the general composition [Au(naza)(PPh3)] (1–8) was prepared and thoroughly characterized (e.g., electrospray ionization (ESI) mass spectrometry and multinuclear nuclear magnetic resonance (NMR) spectroscopy). The N1-deprotonated anions of 7-azaindole or its derivatives (naza) are coordinated to the metal centre through the N1 atom of their pyrrole ring, as proved by a single crystal X-ray analysis of the complexes [Au(3I5Braza)(PPh3)] (7) and [Au(2Me4Claza)(PPh3)]·½H2O (8′). The in vitro cytotoxicity of the complexes 1–8 was studied against both the cisplatin-sensitive and -resistant variants of the A2780 human ovarian carcinoma cell line, as well as against the MRC-5 human normal fibroblast cell line. The complexes 4, 5, and 8, containing deprotonated 3-iodo-7-azaindole, 5-bromo-7-azaindole, and 2-methyl-4-chloro-7-azaindole (2Me4Claza), respectively, showed significantly higher potency (IC50 = 2.8–3.5 µM) than cisplatin (IC50 = 20.3 µM) against the A2780 cells and markedly lower effect towards the MRC-5 non-cancerous cells (IC50 = 26.0–29.2 µM), as compared with the mentioned A2780 cancer cells. The results of the flow cytometric studies of the A2780 cell cycle perturbations revealed a G2-cell cycle phase arrest of the cells treated by the representative complexes 1 and 5, which is indicative of a different mechanism of action from cisplatin (induced S-cell cycle phase arrest). The stability of the representative complex 8 in the water-containing solution as well as its ability to interact with the reduced glutathione, cysteine and bovine serum albumin was also studied using 1H and 31P-NMR spectroscopy (studied in the 50% DMF-d7/50% D2O mixture) and ESI+ mass spectrometry (studied in the 50% DMF/50% H2O mixture); DMF = dimethylformamide. The obtained results are indicative for the release of the N-donor azaindole-based ligand in the presence of the used biomolecules. PMID:27973440

Assessment of dental caries prevention program applied to a cohort of elementary school children of Kebemer, a city in Senegal.

PubMed

Daouda, Faye; Aïda, Kanouté; Mbacké, Lo Cheikh; Mamadou, Mbaye

2016-08-01

Dental caries is frequently observed in children, particularly among those residing in developing countries. The most adapted strategies against this pathology remains prevention based on information, education, and communication (IEC), as well as on early diagnosis and treatment. We carried out a study that aimed to analyze the development of dental caries in a cohort of school children followed during their primary education. The objective was to assess the evolution of the dental status of a cohort of students during their elementary curriculum. A cohort of school children was followed during 6 years from the first grade to the sixth grade. Monitoring of these school children focused every year on IEC based on learning methods of brushing messages, dietary advice, systematic visits, fluoride use, and primary dental care. During the school year, the students were periodically subjected to education and communication briefings (IEC). Primary care consisted of extracting and descaling rhizalyzed teeth in the same period. The data from this review were collected using the World Health Organization questionnaire, and statistical analysis was performed with the software Epi-info version 6.04 d. The mean age of the 171 school children was 6 years in the first grade and 11 years in the sixth grade. In the first grade, the decayed permanent teeth prevalence was 31.6% and the In permanent teeth: Decayed, missing or filled teeth (DMF/T) was 0.47. The decayed primary teeth prevalence was 75% and the in primary teeth: decayed or filled teeth (df/t) 2.23. In the sixth year, the prevalence of decayed permanent teeth was 51% and DMF/T 0.36 whereas the decayed primary teeth prevalence was 12% and the df/t was 0.19. The prevalence of decayed permanent teeth increased from 31.6 to 51% whereas the mean DMF/T was not statistically different between school children of the first and sixth grade class. The promotion of oral health by IEC messages and monitoring of children constitute an effective preventive method for children's oral care.

Aqueous Peroxyoxalate Chemiluminescence.

DTIC Science & Technology

1982-01-01

fluorescence. It should be noted that the chloromethylstyrene, 45, was actually a mixture of the meta and para isomers as received from the supplier...the pentaetWyleneoxy acetylenic derivative, 65. By the conventional scheme, bis-pentaethyleneoxy-BPEA, 66, was obtained as an oil, even after HPLC ...phenylacetylide or lithium amide. The attempted hydrolysis of 56 using NaOH/DMF at reflux gave a semi-solid product, which was not totally pure even after HPLC

Synthesis of Nucleoside Analogues with Potential Antiviral Activity against Negative Strand RNA Virus Targets

DTIC Science & Technology

1989-11-01

standing overnight. Washing the filtered crystals with ether removed triethylamine hydrochloride and triphenyl phosphine, then recrystallisation from...pyridine to from an ester, DMF and pyridinium hydrochloride . The reaction of the Vilsmeier reagent with (E)-5-(2-carboxyvinyl)uridine and quenching...include 2-deoxy-2-glucose (28), D- glucosamine (29) and tunicamycin (30). Deoxyglucose is utilized instead of glucose in the formation of guanosine

Improved Synthesis of 5-Substituted 1H-Tetrazoles via the [3+2] Cycloaddition of Nitriles and Sodium Azide Catalyzed by Silica Sulfuric Acid

PubMed Central

Du, Zhenting; Si, Changmei; Li, Youqiang; Wang, Yin; Lu, Jing

2012-01-01

A silica supported sulfuric acid catalyzed [3+2] cycloaddition of nitriles and sodium azide to form 5-substituted 1H-tetrazoles is described. The protocol can provide a series of 5-substituted 1H-tetrazoles using silica sulfuric acid from nitriles and sodium azide in DMF in 72%–95% yield. PMID:22606004

Reforming the Joint Military Establishment

DTIC Science & Technology

1985-06-01

FOR PUBLIC RELEASE DISTRIBUTION UNLIMITED D UNCLASSIFIED StCURITV CLASJiriCATIOM OP THIS PAOK (*h*> Dmf Enltfd) REPORT DOCUMENTATION PAGE 1...COMPLETING FORM i Rt t lRNT’S CATALOG NUMBER 5. TYPE OF HEBORT 4 PCRIOC COVCRCO Final S. PERFORMING ORO. REPORT NUMICR B. CONTRACT OR GRANT...NUMBERft; 10. PROGRAM ELCMENT. PROJECT, TASK AREA ft WORK UNIT NUMBERS U. REPORT OAT1 June 1985 𔃽. NUMBER OF PAGES 78 IS. SECURITY CLASS

Mortality from Listeria monocytogenes meningoencephalitis following escalation to alemtuzumab therapy for relapsing-remitting Multiple Sclerosis.

PubMed

Canham, L J W; Manara, A; Fawcett, J; Rolinski, M; Mortimer, A; Inglis, K E A; Cottrell, D A

2018-05-18

We report the case of a patient who died from the rare complication of Listeriosis in the immediate phase following alemtuzumab administration one month after discontinuing dimethyl fumarate (DMF). There is considerable overlap with typical post-infusion symptoms therefore high surveillance and low threshold for empirical or possible prophylactic antibiotic therapy is advocated. Copyright © 2018. Published by Elsevier B.V.

Highly Sensitive Detection of UV Radiation Using a Uranium Coordination Polymer.

PubMed

Liu, Wei; Dai, Xing; Xie, Jian; Silver, Mark A; Zhang, Duo; Wang, Yanlong; Cai, Yawen; Diwu, Juan; Wang, Jian; Zhou, Ruhong; Chai, Zhifang; Wang, Shuao

2018-02-07

The accurate detection of UV radiation is required in a wide range of chemical industries and environmental or biological related applications. Conventional methods taking advantage of semiconductor photodetectors suffer from several drawbacks such as sophisticated synthesis and manufacturing procedure, not being able to measure the accumulated UV dosage as well as high defect density in the material. Searching for new strategies or materials serving as precise UV dosage sensor with extremely low detection limit is still highly desirable. In this work, a radiation resistant uranium coordination polymer [UO 2 (L)(DMF)] (L = 5-nitroisophthalic acid, DMF = N,N-dimethylformamide, denoted as compound 1) was successfully synthesized through mild solvothermal method and investigated as a unique UV probe with the detection limit of 2.4 × 10 -7 J. On the basis of the UV dosage dependent luminescence spectra, EPR analysis, single crystal structure investigation, and the DFT calculation, the UV-induced radical quenching mechanism was confirmed. Importantly, the generated radicals are of significant stability which offers the opportunity for measuring the accumulated UV radiation dosage. Furthermore, the powder material of compound 1 was further upgraded into membrane material without loss in luminescence intensity to investigate the real application potentials. To the best of our knowledge, compound 1 represents the most sensitive coordination polymer based UV dosage probe reported to date.

New Cu (II), Co(II) and Ni(II) complexes of chalcone derivatives: Synthesis, X-ray crystal structure, electrochemical properties and DFT computational studies

NASA Astrophysics Data System (ADS)

Tabti, Salima; Djedouani, Amel; Aggoun, Djouhra; Warad, Ismail; Rahmouni, Samra; Romdhane, Samir; Fouzi, Hosni

2018-03-01

The reaction of nickel(II), copper(II) and cobalt(II) with 4-hydroxy-3-[(2E)-3-(1H-indol-3-yl)prop-2-enoyl]-6-methyl-2H-pyran-2-one (HL) leads to a series of new complexes: Ni(L)2(NH3), Cu(L)2(DMF)2 and Co(L)2(H2O). The crystal structure of the Cu(L)2(DMF)2 complex have been determined by X-ray diffraction methods. The Cu(II) lying on an inversion centre is coordinated to six oxygen atoms forming an octahedral elongated. Additionally, the electrochemical behavior of the metal complexes were investigated by cyclic voltammetry at a glassy carbon electrode (GC) in CH3CN solutions, showing the quasi-reversible redox process ascribed to the reduction of the MII/MI couples. The X-ray single crystal structure data of the complex was matched excellently with the optimized monomer structure of the desired compound; Hirschfeld surface analysis supported the packed crystal lattice 3D network intermolecular forces. HOMO/LUMO energy level and the global reactivity descriptors quantum parameters are also calculated. The electrophilic and nucleophilic potions in the complex surface are theoretically evaluated by molecular electrostatic potential and Mulliken atomic charges analysis.

Quantum chemical modeling of new derivatives of (E,E)-azomethines: Synthesis, spectroscopic (FT-IR, UV/Vis, polarization) and thermophysical investigations

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Sheikhi, Masoome; Filippovich, Liudmila; Anatol'evich, Dikusar Evgenij; Yahyaei, Hooriye

2017-06-01

In the present work, the molecular structures of three new azomethine dyes: N-benzylidene-4-((E)-phenyldiazenyl)aniline (PAZB-1), 2-methoxy-4-(((4-((E)- phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-2) and 2-methoxy-5-((E)-((4-((E)- phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-8) have been predicted and investigated using Density Functional Theory (DFT) in dimethylformamide (DMF). The geometries of the azomethine dyes were optimized by PBE0/6-31 + G* level of theory. The electronic spectra of these azomethine dyes in a DMF solution was carried out by TDPBE0/6-31 + G* method. After quantum-chemical calculations three new azomethine dyes for optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. The computed absorption spectral data of the azomethine dyes are in good agreement with the experimental data, thus allowing an assignment of the UV/Vis spectra. On the basis of polyvinyl alcohol (PVA) and the new synthesized azomethine dyes polarizing films for Visible region of spectrum were developed. The main optical parameters of polarizing PVA-films (Transmittance, Polarization Efficiency and Dichroic Ratio) have been measured and discussed. Anisotropy of thermal conductivity of the PVA-films has been studied.

Radioprotective effect of polyethylene glycol

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

Shaeffer, J.; Schellenberg, K.A.; Seymore, C.H.

1986-07-01

Polyethylene glycol of molecular weight 400 (PEG-400) had a radioprotective effect of about 20% against lethality when given ip 20 min prior to single or fractionated X-ray doses to the head and neck. Dose modification factors (DMF) based on LD50/15 values ranged from 1.14 to 1.24. A similar DMF of 1.12 based on LD50/30 values was obtained using single doses of whole-body X irradiation. Mice given head and neck irradiation had significantly reduced rectal temperatures (31.3 +/- 3.0/sup 0/C) 9 days post irradiation compared with unirradiated controls (35.4 +/- 0.6/sup 0/C). No such reduction was observed when PEG-400 was givenmore » with radiation (36.3 +/- 0.9/sup 0/C). PEG-400 also lessened, but not significantly, the frequency of shivering in irradiated animals. Histopathologic examination of the oral structures demonstrated only marginal protection by PEG-400. Estimation of the alpha/beta ratio from LD50 data on head and neck-irradiated mice yielded values of 4.4 +/- 1.9 (95% confidence limits) Gy without PEG-400 and 7.9 +/- 1.4 Gy with PEG-400. Since it is a non-thiol radioprotector, PEG-400 may be more useful when combined with more conventional thiol-containing radioprotectors.« less

Assessment of antiradiation drug effectiveness to fission neutron irradiation. Annual report No. 1, April-August 1981

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

Sigdestad, C.P.

1981-09-01

This report deals with the assays of various compounds for their toxicity of anti-radiation efficacy following exposure to either Co-60 or fission neutron irradiation. The compounds reported herein include WR 347, WR 2721, WR 3689, WR 44923, WR 109342, WR 151327, WR 16843, and WR 176542. The end-points measured in the radiation studies were LD50(6) and LD50(30). The compounds and their dose modification factors (DMF) for the neutron LD50(6) following i.p. administration, were, in descending order of effectiveness: WR 151327 (1.42), WR 347 (1.37), WR 3689 (1.34) WR 44923 (1.34), WR 2721 (1.26), WR 168643 (1.24), and WR 176542 (1.23).more » The corresponding LD50(30)'s for fission neutron irradiation following i.p. administration, were: WR 168643 (1.67), WR 3689 (1.52), WR 151327 (1.45), WR 44923 (1.39), WR 347 (1.22), WR 2721 (1.21), and WR 176542 (1.18). For low LET Co-60 gamma irradiation the LD50(6) and LD50(30) were determined for WR 347 following i.p. administration. The DMF's obtained were: LD50(6) (1.4), LD50(30) (1.5).« less

Self-assembly of a thin highly reduced graphene oxide film and its high electrocatalytic activity

NASA Astrophysics Data System (ADS)

Bai, Yan-Feng; Zhang, Yong-Fang; Zhou, An-Wei; Li, Hai-Wai; Zhang, Yu; Luong, John H. T.; Cui, Hui-Fang

2014-10-01

A thin highly reduced graphene oxide (rGO) film was self-assembled at the dimethyl formamide (DMF)-air interface through evaporation-induced water-assisted thin film formation at the pentane-DMF interface, followed by complete evaporation of pentane. The thin film was transferred onto various solid substrates for film characterization and electrochemical sensing. UV-visible spectrometry, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemistry techniques were used to characterize the film. An rGO film showing 82.8% of the transmittance at 550 nm corresponds to a few layers of rGO nanosheets. The rGO nanosheets cross-stack with each other, lying approximately in the plane of the film. An rGO film collected on a glassy carbon (GC) electrode exhibited improved electrical conductivity compared to GC, with the electrode charge-transfer resistance (Rct) reduced from 31 Ω to 22 Ω. The as-formed rGO/GC electrode was mechanically very stable, exhibiting significantly enhanced electrocatalytic activity to H2O2 and dopamine. Multiple layers of the rGO films on the GC electrode showed even stronger electrocatalytic activity to dopamine than that of the single rGO film layer. The controllable formation of a stable rGO film on various solid substrates has potential applications for nanoelectronics and sensors/biosensors.

Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals

NASA Astrophysics Data System (ADS)

Yadav, Manju; Mishra, Neelima; Sharma, Nutan; Chandra, Sulekh; Kumar, Dinesh

2014-11-01

This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X = O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV-Vis, NMR (1H, 119Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37 °C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively.

Dimethyl sulfoxide and dimethyl formamide increase lifespan of C. elegans in liquid.

PubMed

Frankowski, Harald; Alavez, Silvestre; Spilman, Patricia; Mark, Karla A; Nelson, Joel D; Mollahan, Pamela; Rao, Rammohan V; Chen, Sylvia F; Lithgow, Gordon J; Ellerby, H Michael

2013-03-01

Lifespan extension through pharmacological intervention may provide valuable tools to understanding the mechanisms of aging and could uncover new therapeutic approaches for the treatment of age-related disease. Although the nematode Caenorhabditis elegans is well known as a particularly suitable model for genetic manipulations, it has been recently used in a number of pharmacological studies searching for compounds with anti-aging activity. These compound screens are regularly performed in amphipathic solvents like dimethyl sulfoxide (DMSO), the solvent of choice for high-throughput drug screening experiments performed throughout the world. In this work, we report that exposing C. elegans to DMSO in liquid extends lifespan up to 20%. Interestingly, another popular amphipathic solvent, dimethyl formamide (DMF), produces a robust 50% increase in lifespan. These compounds work through a mechanism independent of insulin-like signaling and dietary restriction (DR). Additionally, the mechanism does not involve an increased resistance to free radicals or heat shock suggesting that stress resistance does not play a major role in the lifespan extension elicited by these compounds. Interestingly, we found that DMSO and DMF are able to decrease the paralysis associated with amyloid-β3-42 aggregation, suggesting a role of protein homeostasis for the mechanism elicited by these molecules to increase lifespan. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A new tridentate Schiff base Cu(II) complex: synthesis, experimental and theoretical studies on its crystal structure, FT-IR and UV-Visible spectra.

PubMed

Saheb, Vahid; Sheikhshoaie, Iran; Setoodeh, Nasim; Rudbari, Hadi Amiri; Bruno, Giuseppe

2013-06-01

A new Cu(II) complex [Cu(L)(NCS)] has been synthesized, using 1-(N-salicylideneimino)-2-(N,N-methyl)-aminoethane as tridentate ONN donor Schiff base ligand (HL). The dark green crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FT-IR) and UV-Visible spectra. Electronic structure calculations at the B3LYP and MP2 levels of theory are performed to optimize the molecular geometry and to calculate the UV-Visible and FT-IR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TD-DFT) method is used to calculate the electronic transitions of the complex. A scaling factor of 1.015 is obtained for vibrational frequencies computed at the B3LYP level using basis sets 6-311G(d,p). It is found that solvent has a profound effect on the electronic absorption spectrum. The UV-Visible spectrum of the complex recorded in DMSO and DMF solution can be correctly predicted by a model in which DMSO and DMF molecules are coordinated to the central Cu atom via their oxygen atoms. Copyright © 2013 Elsevier B.V. All rights reserved.

Genotoxicity of Advanced Glycation End Products: Involvement of Oxidative Stress and of Angiotensin II Type 1 Receptors

NASA Astrophysics Data System (ADS)

Schupp, Nicole; Schinzel, Reinhard; Heidland, August; Stopper, Helga

2005-06-01

In patients with chronic renal failure, cancer incidence is increased. This may be related to an elevated level of genomic damage, which has been demonstrated by micronuclei formation as well as by comet assay analysis. Advanced glycation end products (AGEs) are markedly elevated in renal failure. In the comet assay, the model AGEs methylglyoxal- and carboxy(methyl)lysine-modified bovine serum albumin (BSA) induced significant DNA damage in colon, kidney, and liver cells. The addition of antioxidants prevented AGE-induced DNA damage, suggesting enhanced formation of reactive oxygen species (ROS). The coincubation with dimethylfumarate (DMF), an inhibitor of NF-κB translocation, reduced the genotoxic effect, thereby underscoring the key role of NF-κB in this process. One of the genes induced by NF-κB is angiotensinogen. The ensuing proteolytic activity yields angiotensin II, which evokes oxidative stress as well as proinflammatory responses. A modulator of the renin-angiotensin system (RAS), the angiotensin II (Ang II) receptor 1 antagonist, candesartan, yielded a reduction of the AGE-induced DNA damage, connecting the two signal pathways, RAS and AGE signaling. We were able to identify important participants in AGE-induced DNA damage: ROS, NF-κB, and Ang II, as well as modulators to prevent this DNA damage: antioxidants, DMF, and AT1 antagonists.

Synthesis, crystal structure and study of magnetocaloric effect and single molecular magnetic behaviour in discrete lanthanide complexes.

PubMed

Adhikary, Amit; Sheikh, Javeed Ahmad; Biswas, Soumava; Konar, Sanjit

2014-06-28

The synthesis, crystal structure and magnetic properties of four polynuclear lanthanide coordination complexes having molecular formulae, [Gd3(2)(1)L(H2O)8(Cl)](Cl)4·10H2O (1), [Dy3L(2)(1)(H2O)9](Cl)5·6H2O (2) [Gd6L(2)(2)(HCO2)4(μ3-OH)4(DMF)6(H2O)2](Cl)2·4H2O (3) and [Dy6L(2)(2)(HCO2)4(μ3-OH)4(DMF)6(H2O)2](Cl)2·4H2O (4) (where H2L(1) = bis[(2-pyridyl)methylene]pyridine-2,6-dicarbohydrazide and H4L(2) = bis[2-hydroxy-benzylidene]pyridine-2,6-dicarbohydrazide) are reported. Structural investigation by X-ray crystallography reveals similar structural features for complexes 1 and 2 and they exhibit butterfly like shapes of the molecules. Non-covalent interactions between the molecules create double helical arrangements for both molecules. Complexes 3 and 4 are isostructural and the core structures feature four distorted hemi-cubanes connected by vertex sharing. Magnetic studies unveil significant magnetic entropy changes for complexes 1, 3 and slow relaxation of magnetization for both dysprosium analogues 2 and 4.

Chromatin- and temperature-dependent modulation of radiation-induced double-strand breaks.

PubMed

Elmroth, K; Nygren, J; Stenerlöw, B; Hultborn, R

2003-10-01

To investigate the influence of chromatin organization and scavenging capacity in relation to irradiation temperature on the induction of double-strand breaks (DSB) in structures derived from human diploid fibroblasts. Agarose plugs with different chromatin structures (intact cells+/-wortmannin, permeabilized cells with condensed chromatin, nucleoids and DNA) were prepared and irradiated with X-rays at 2 or 37 degrees C and lysed using two different lysis protocols (new ice-cold lysis or standard lysis at 37 degrees C). Induction of DSB was determined by constant-field gel electrophoresis. The dose-modifying factor (DMF(temp)) for irradiation at 37 compared with 2 degrees C was 0.92 in intact cells (i.e. more DSB induced at 2 degrees C), but gradually increased to 1.5 in permeabilized cells, 2.2 in nucleoids and 2.6 in naked DNA, suggesting a role of chromatin organization for temperature modulation of DNA damage. In addition, DMF(temp) was influenced by the presence of 0.1 M DMSO or 30 mM glutathione, but not by post-irradiation temperature. The protective effect of low temperature was correlated to the indirect effects of ionizing radiation and was not dependent on post-irradiation temperature. Reasons for a dose modifying factor <1 in intact cells are discussed.

Application of dense gas techniques for the production of fine particles.

PubMed

Foster, Neil R; Dehghani, Fariba; Charoenchaitrakoo, Kiang M; Warwick, Barry

2003-01-01

The feasibility of using dense gas techniques such as rapid expansion of supercritical solutions (RESS) and aerosol solvent extraction system (ASES) for micronization of pharmaceutical compounds is demonstrated. The chiral nonsteroidal anti-inflammatory racemic ibuprofen is soluble in carbon dioxide at 35 degrees C and pressures above 90 bar. The particle size decreased to less than 2 microm while the degree of crystallinity was slightly decreased when processed by RESS. The dissolution rate of the ibuprofen (a poorly water-soluble compound) was significantly enhanced after processing by RESS. The nonsteroidal anti-inflammatory drug Cu2(indomethacin)4L2(Cu-Indo); (L = dimethylformamide [DMF]), which possessed very low solubility in supercritical CO2, was successfully micronized by ASES at 25 degrees C and 68.9 bar using DMF as the solvent and CO2 as the antisolvent. The concentration of solute dramatically influenced the precipitate characteristics. The particles obtained from the ASES process were changed from bipyramidal to spherical, with particle size less than 5 microm, as the concentration increased from 5 to 100 mg/g. A further increase in solute concentration to 200 mg/g resulted in large porous spheres, between 20 and 50 micron, when processing Cu-Indo by the ASES method. The dissolution rate of the micronized Cu-Indo was significantly higher than the commercial product.

Comparative 4f-4f absorption spectral study for the interactions of Nd(III) with some amino acids: Preliminary thermodynamics and kinetic studies of interaction of Nd(III):glycine with Ca(II)

NASA Astrophysics Data System (ADS)

Moaienla, T.; Bendangsenla, N.; David Singh, Th.; Sumitra, Ch.; Rajmuhon Singh, N.; Indira Devi, M.

2012-02-01

Spectral analysis of Nd(III) complexes with some amino acids viz.; glycine, L-alanine, L-phenylalanine and L-aspartic acid in the presence and absence of Ca 2+ was carried out in some organic solvents; CH 3OH, CH 3CN, DMF and dioxane using comparative absorption spectra of 4f-4f transitions. The study was carried out by evaluating various energy interaction parameters like Slator-Condon ( Fk), Lande factor ( ξ4f), nephelauxetic ratio ( β), bonding parameter ( b1/2), percent-covalency ( δ) by applying partial and multiple regression analysis. The values of oscillator strength ( Pobs) and Judd-Ofelt electric dipole intensity parameter Tλ ( λ = 2, 4, 6) for different 4f-4f transitions have been calculated. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength ( Pobs) and Tλ values, reveal the mode of binding with the different ligands. Kinetic studies for the complexation of Nd(III):glycine:Ca(II) have also been discussed at different temperatures in DMF medium and from it the values of activation energy ( Ea) and thermodynamic parameters like Δ H°, Δ S° and Δ G° for the complexation are evaluated.

Synthesis and characterization of silver nanowires with zigzag morphology in N, N-dimethylformamide

NASA Astrophysics Data System (ADS)

He, Xin; Zhao, Xiujian; Chen, Yunxia; Feng, Jinyang; Sun, Zhenya

2007-08-01

Zigzag silver nanowires with a uniform diameter of 20±5 nm were prepared by reducing silver nitrate (AgNO 3) with N, N-dimethylformamide (DMF) in the presence of tetrabutyl titanate (TBT) and acetylacetone (AcAc) at 373 K for 18 h. X-ray and selected area electron diffraction (XRD and SAED) patterns reveal that the prepared product is made of pure silver with face centered cubic structure. Transmission electron microscopy (TEM) investigations suggest that the amount of silver nanowires is enhanced with increase in reaction time, and the end-to-end assemblies of silver nanorods are observed during the reaction process. After 18 h reaction, silver nanowires with zigzag morphology are obtained. In this paper, a possible growth process of silver nanowires with this interesting shape is described. Silver nanoparticles with small sizes were obtained by reducing Ag + ions with DMF, providing seeds for homogeneous growth of silver nanorods. With the extending reaction time, the synthesized silver nanorods were connected in an end-to-end manner, and the interface between the connections of two nanorods gradually disappeared. The final product shows zigzag morphology with various angles. The angles between two connecting straight parts of zigzag nanowires exhibit an alterable range of 74-151°. These silver nanowires show tremendous potential applications in future nanoscale electronic circuits.

Neutral ligand TIPA-based two 2D metal-organic frameworks: ultrahigh selectivity of C2H2/CH4 and efficient sensing and sorption of Cr(vi ).

PubMed

Fu, Hong-Ru; Zhao, Ying; Zhou, Zhan; Yang, Xiao-Gang; Ma, Lu-Fang

2018-03-12

One neutral tripodal semi-rigidity ligand tri(4-imidazolylphenyl)amine (TIPA) with excellent hole-transfer nature, was selected as a linker to construct MOFs. Two two-dimensional (2D) microporous metal-organic frameworks (MOFs) were synthesized solvothermally: [Ni(TIPA)(COO - ) 2 (H 2 O)]·2(DMF)2(H 2 O) (1) and [Cd(TIPA) 2 (ClO 4 - ) 2 ]·(DMF)3(H 2 O) (2). Compound 1 incorporated carboxylic groups into the channel and exhibited the high capacity of light hydrocarbons as well as the remarkable selectivity of C 2 H 2 /CH 4 . The value is in excess of 100 at room temperature, which is the highest value reported to date. Compound 2, as a cationic framework with high water stability, was not only applied as a sensor, displaying the ultrahigh sensitivity against Cr 2 O 7 2- with a detection limit as low as 8 ppb, but also possessed excellent Cr(vi) sorption with good repeatability in aqueous solution. This study provides an efficient strategy to design cationic MOFs for the selective separation of light hydrocarbons and the sensing and trapping of toxic chromate for the purification of water.

2,6-diacetylpyridine bis(thiosemicarbazones) zinc complexes: synthesis, structure, and biological activity.

PubMed

Rodriguez-Argüelles, M C; Belicchi Ferrari, M; Gasparri Fava, G; Pelizzi, C; Tarasconi, P; Albertini, R; Dall'Aglio, P P; Lunghi, P; Pinelli, S

1995-05-15

The reaction of zinc chloride, acetate, or perchlorate with two bis(thiosemicarbazones) of 2,6-diacetylpyridine [H2daptsc = 2,6-diacetylpyridine bis(thiosemicarbazone) and H2dapipt = 2,6-diacetylpyridine bis(hydrazinopyruvoylthiosemicarbazone)] leads to the formation of four novel complexes that have been characterized by spectroscopic studies (NMR, IR) and biological properties. The crystal structures of the two compounds--[Zn(daptsc)]2.2DMF (1) and [Zn(H2dapipt)(OH2)2](CIO4)2.3H2O (2)--also have been determined by x-ray methods from diffractometer data. Compound (1) is dimeric and the two zinc atoms have a distorted octahedral coordination. The ligand is deprotonated. In compound (2), the coordination geometry about zinc is pentagonal--bipyramidal and the ligand is in the neutral form. The molecular structure of (2) consists of cations [Zn(H2dapipt)(OH2)]2+, CIO4- disordered anions, and three water molecules of solvation. Biological studies have shown that the ligands and the complexes Zn(daptsc).1/2EtOH and Zn(H2daptsc)Cl2 have an effect in vitro on cell proliferation and differentiation (inhibition); both are concentration dependent. [Zn(daptsc)]2.2DMF (1) shows the effects at lower concentration values with respect to other compounds.

Effect of reaction solvent on hydroxyapatite synthesis in sol-gel process

NASA Astrophysics Data System (ADS)

Nazeer, Muhammad Anwaar; Yilgor, Emel; Yagci, Mustafa Baris; Unal, Ugur; Yilgor, Iskender

2017-12-01

Synthesis of hydroxyapatite (HA) through sol-gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorus precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant. A measure of 0.5 M aqueous DAHP solution was used in all reactions while CNTH was dissolved in distilled water, tetrahydrofuran (THF) and N,N-dimethylformamide (DMF) at a concentration of 0.5 M. Ammonia solution (28-30%) was used to maintain the pH of the reaction mixtures in the 10-12 range. All reactions were carried out at 40 ± 2°C for 4 h. Upon completion of the reactions, products were filtered, washed and calcined at 500°C for 2 h. It was clearly demonstrated through various techniques that the dielectric constant and polarity of the solvent mixture strongly influence the chemical structure and morphological properties of calcium phosphate synthesized. Water-based reaction medium, with highest dielectric constant, mainly produced β-calcium pyrophosphate (β-CPF) with a minor amount of HA. DMF/water system yielded HA as the major phase with a very minor amount of β-CPF. THF/water solvent system with the lowest dielectric constant resulted in the formation of pure HA.

Juvenile idiopathic arthritis activity and function ability: deleterious effects in periodontal disease?

PubMed

Pugliese, Camila; van der Vinne, Roberta T A; Campos, Lucia M A; Guardieiro, Priscila R; Saviolli, Cynthia; Bonfá, Eloisa; Pereira, Rosa M R; Viana, Vilma S; Borba, Eduardo F; Silva, Clovis A

2016-01-01

The impact of juvenile idiopathic arthritis (JIA) in periodontal diseases is controversial probably due to gender and age heterogeneity. We therefore evaluated a homogeneous female post-pubertal JIA population for these conditions. Thirty-five JIA patients and 35 gender/age comparable healthy controls were evaluated according to demographic data, complete periodontal evaluation, fasting lipoproteins, and anti-lipoprotein lipase antibodies. JIA scores, laboratorial tests, X-rays, and treatment were also assessed. Current age was similar in JIA patients and controls (11.90 ± 2.0 vs. 12.50 ± 3.0 years, p = 0.289). Complete periodontal assessments revealed that gingival index, dental plaque, gingival bleeding, and clinical dental attachment indices were alike in JIA patients and controls (p > 0.05), except for gingival enlargement in former group (p < 0.0001). Further analysis of patients with and without gingivitis revealed that cyclosporine use was more often observed in JIA patients with gingivitis (37 vs. 0%, p = 0.01), whereas no differences were evidenced in demographic, JIA scores, inflammatory markers, and lipid profile in both groups. Of note, two parameters of periodontal assessment were correlated with JIA scores [gingival index (GI) and Childhood Health Assessment Questionnaire (CHAQ) (r s  = +0.402, p = 0.020)] and plaque index (PI) and visual analog scale (VAS) physician (r s  = +0.430, p = 0.013). In addition, evaluation of dental assessment demonstrated that JIA activity scores had positive correlation with decayed, missing, and filled teeth (DMF-T) and junvenile athritis disease activity score (JADAS) (r s  = +0.364,p = 0.037), VAS physician (r s  = +0.401,p = 0.021) and VAS patient (r s  = +0.364,p = 0.037). We demonstrated, using rigorous criteria, that periodontal and dental condition in JIA is similar to controls. In spite of that, the finding of a correlation with disease parameters provides additional evidence that increased activity and reduced functional ability underlies the deleterious effect of JIA in oral health.

Optical limiting and bleaching effects in a suspension of onion-like carbon

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

Mikheev, Gen M; Bulatov, D L; Mogileva, T N

We have studied the effect of nanosecond laser pulses ({lambda} = 1064 nm) on the optical properties of onion-like carbon (OLC) prepared by high-temperature vacuum annealing of detonation nanodiamond and dispersed in N,N-dimethylformamide (DMF). The results demonstrate that, under low-intensity irradiation, the OLC suspension displays optical limiting behaviour. Increasing the incident intensity leads to bleaching of the suspension in the visible and near-IR spectral regions. (nanostructures)

Lithium Cell Reactions.

DTIC Science & Technology

1985-02-01

electrolyte has been characterized by both infrared and voltammetric analysis, some of the results of these earlier electrolyses ex- periments can be better...understood. For example, 16 hours after the constant current electrolyses of 8 mg of SOC 2 acid electrolyte in DMF to n = 1.12 at a Pt cathode, the...with the SOCI2 electrolyte which produced residues that could not be removed by common solvents (except water ). Thus, after several hours of use, it

[FeIII(SR)4]1− Complexes Can Be Synthesized By the Direct Reaction of Thiolates With FeCl3**

PubMed Central

Chang, Sechin; Koch, Stephen A.

2007-01-01

It is shown that the previously characterized [FeIII(SR)4]1− (R= Et, i-Pr, Ph) complexes can be synthesized by the direct reaction of 4 equiv of LiSR with FeCl3 in DMF solution. [FeIII(SR)4]1− complexes are synthetic analogs for the [FeIII(S-Cys)4] center in rubredoxin proteins. PMID:17723243

Synthesis and Modification of Carboxylated Polyphenylenes and Phenylated Polyimides

DTIC Science & Technology

1976-03-01

corresponding grignard reagent , which was allowed to react with DMF19 to provide the benzalde- hyde 50. This aldehyde, however, failed to undergo a benzoin...bromophenylethynyl )-trimethyl- silane in 100 ml THF was refluxed 2 hr with 1.6 g (0.066 g atm) of magnesium to form the Grignard reagent . To the...toluene (Table 2). The crown other reagent , however, could not be completely removed from the resulting ionomer. Treatment of the carboxylated

Impacts on quality of life related to dental caries in a national representative sample of Thai 12- and 15-year-olds.

PubMed

Krisdapong, S; Prasertsom, P; Rattanarangsima, K; Sheiham, A

2013-01-01

Dental caries is generally given the highest priority in national oral health services for school-aged populations. Yet, there is no study exploring the impacts on quality of life specifically related to dental caries in national samples of school-aged children. This study assessed prevalence and characteristics of oral impacts attributed to dental caries on quality of life and compared them with overall oral health impacts. In addition, associations of oral impacts attributed to dental caries and dental caries status were investigated. A national representative sample of 1,063 12- and 811 15-year-olds completed a sociodemographic and behavioural questionnaire, and were orally examined and interviewed about oral health-related quality of life using the Child-OIDP or OIDP indexes, respectively. Associations of condition-specific impacts (CS impacts) attributed to dental caries with components of DMF were investigated using χ(2) tests and multivariate logistic regressions. CS impacts attributed to dental caries were reported by nearly half the children and such impacts accounted for half of overall oral impacts from all oral conditions. The majority of impacts were of little intensity and affected only 1-2 daily performances, particularly performances on Eating, Emotional stability and Cleaning teeth. CS impacts were significantly positively associated with number of decayed teeth, and strongly associated with severe decay. Copyright © 2012 S. Karger AG, Basel.

Singlet oxygen feedback delayed fluorescence of protoporphyrin IX in organic solutions.

PubMed

Vinklárek, Ivo S; Scholz, Marek; Dědic, Roman; Hála, Jan

2017-04-12

Delayed fluorescence (DF) of protoporphyrin IX (PpIX) has been recently proposed as a tool for monitoring of mitochondrial oxygen tension in vivo as well as for observation of the effectiveness of photodynamic therapy (PDT) [E. G. Mik, Anesth. Analg., 2013, 117, 834-346; F. Piffaretti et al., J. Biomed. Opt., 2012, 17, 115007]. However, the efficiency of the mechanism of thermal activation (E-type DF), which was considered in the papers, is limited due to a large energy gap between the first excited singlet and the first triplet state of PpIX at room or body temperatures. Moreover, the energy gap is roughly equal to other porphyrinoid photosensitizers that generate DF mostly through the Singlet Oxygen Feedback-Induced mechanism (SOFDF) under certain conditions [M. Scholz and R. Dědic, Singlet Oxygen: Applications in Biosciences and Nanosciences, 2016, vol. 2, pp. 63-81]. The mechanisms of delayed fluorescence of PpIX dissolved either in dimethylformamide (DMF) or in the mixture of DMF with ethylene glycol (EG) were investigated at atmospheric partial pressure of oxygen by means of a simultaneous time-resolved detection of 1 O 2 phosphorescence and PpIX DF which makes a direct comparison of the kinetics and lifetimes of both the luminescence channels possible. Samples of PpIX (100 μM) exhibit concave DF kinetics, which is a typical footprint of the SOFDF mechanism. The dramatic decrease in the DF intensity after adding a selective 1 O 2 quencher sodium azide (NaN 3 , 10 mM) proves that >90% of DF is indeed generated through SOFDF. Moreover, the analysis of the DF kinetics in the presence of NaN 3 implies that the second significant mechanism of DF generation is the triplet-triplet annihilation (P-type DF). The bimolecular mechanism of DF was further confirmed by the decrease of the DF intensity in the more viscous mixture DMF/EG and by the increase of the ratio of DF to the prompt fluorescence (PF) intensity with the increasing excitation intensity. These results show the significant role of the SOFDF mechanism in the DF of PpIX at high concentrations and at atmospheric partial pressure of oxygen and should be considered when developing diagnostic tools for clinical applications.

Carbon Nanotube Dispersion in Solvents and Polymer Solutions: Mechanisms, Assembly, and Preferences.

PubMed

Pramanik, Chandrani; Gissinger, Jacob R; Kumar, Satish; Heinz, Hendrik

2017-12-26

Debundling and dispersion of carbon nanotubes (CNTs) in polymer solutions play a major role in the preparation of carbon nanofibers due to early effects on interfacial ordering and mechanical properties. A roadblock toward ultrastrong fibers is the difficulty to achieve homogeneous dispersions of CNTs in polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) precursor solutions in solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF). In this contribution, molecular dynamics simulations with accurate interatomic potentials for graphitic materials that include virtual π electrons are reported to analyze the interaction of pristine single wall CNTs with the solvents and polymer solutions at 25 °C. The results explain the barriers toward dispersion of SWCNTs and quantify CNT-solvent, polymer-solvent, as well as CNT-polymer interactions in atomic detail. Debundling of CNTs is overall endothermic and unfavorable with dispersion energies of +20 to +30 mJ/m 2 in the pure solvents, + 20 to +40 mJ/m 2 in PAN solutions, and +20 to +60 mJ/m 2 in PMMA solutions. Differences arise due to molecular geometry, polar, van der Waals, and CH-π interactions. Among the pure solvents, DMF restricts CNT dispersion less due to the planar geometry and stronger van der Waals interactions. PAN and PMMA interact favorably with the pure solvents with dissolution energies of -0.7 to -1.1 kcal per mole monomer and -1.5 to -2.2 kcal per mole monomer, respectively. Adsorption of PMMA onto CNTs is stronger than that of PAN in all solvents as the molecular geometry enables more van der Waals contacts between alkyl groups and the CNT surface. Polar side groups in both polymers prefer interactions with the polar solvents. Higher polymer concentrations in solution lead to polymer aggregation via alkyl groups and reduce adsorption onto CNTs. PAN and PMMA solutions in DMSO and dilute solutions in DMF support CNT dispersion more than other combinations whereby the polymers significantly adsorb onto CNTs in DMSO solution. The observations by molecular simulations are consistent with available experimental data and solubility parameters and aid in the design of carbon nanofibers. The methods can be applied to other multiphase graphitic materials.

Electrospun polyurethane/hydroxyapatite bioactive scaffolds for bone tissue engineering: the role of solvent and hydroxyapatite particles.

PubMed

Tetteh, G; Khan, A S; Delaine-Smith, R M; Reilly, G C; Rehman, I U

2014-11-01

Polyurethane (PU) is a promising polymer to support bone-matrix producing cells due to its durability and mechanical resistance. In this study two types of medical grade poly-ether urethanes Z3A1 and Z9A1 and PU-Hydroxyapatite (PU-HA) composites were investigated for their ability to act as a scaffold for tissue engineered bone. PU dissolved in varying concentrations of dimethylformamide (DMF) and tetrahydrofuran (THF) solvents were electrospun to attain scaffolds with randomly orientated non-woven fibres. Bioactive polymeric composite scaffolds were created using 15 wt% Z3A1 in a 70/30 DMF/THF PU solution and incorporating micro- or nano-sized HA particles in a ratio of 3:1 respectively, whilst a 25 wt% Z9A1 PU solution was doped in ratio of 5:1. Chemical properties of the resulting composites were evaluated by FTIR and physical properties by SEM. Tensile mechanical testing was carried out on all electrospun scaffolds. MLO-A5 osteoblastic mouse cells and human embryonic mesenchymal progenitor cells, hES-MPs were seeded on the scaffolds to test their biocompatibility and ability to support mineralised matrix production over a 28 day culture period. Cell viability was assayed by MTT and calcium and collagen deposition by Sirius red and alizarin red respectively. SEM images of both electrospun PU scaffolds and PU-HA composite scaffolds showed differences in fibre morphology with changes in solvent combinations and size of HA particles. Inclusion of THF eliminated the presence of beads in fibres that were present in scaffolds fabricated with 100% DMF solvent, and resulted in fibres with a more uniform morphology and thicker diameters. Mechanical testing demonstrated that the Young׳s Modulus and yield strength was lower at higher THF concentrations. Inclusion of both sizes of HA particles in PU-HA solutions reinforced the scaffolds leading to higher mechanical properties, whilst FTIR characterisation confirmed the presence of HA in all composite scaffolds. Although all scaffolds supported proliferation of both cell types and deposition of calcified matrix, PU-HA composite fibres containing nano-HA enabled the highest cell viability and collagen deposition. These scaffolds have the potential to support bone matrix formation for bone tissue engineering. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Synthesis of 7-azabicyclo[2.2.1]heptane and 2-oxa-4-azabicyclo[3.3.1]non-3-ene derivatives by base-promoted heterocyclization of alkyl N-(cis(trans)-3,trans(cis)-4-dibromocyclohex-1-yl)carbamates and N-(cis(trans)-3,trans(cis)-4-dibromocyclohex-1-yl)-2,2,2-trifluoroacetamides.

PubMed

Gómez-Sanchez, Elena; Soriano, Elena; Marco-Contelles, José

2007-11-09

We have studied the base-promoted heterocyclization of alkyl N-(cis(trans)-3,trans(cis)-4-dibromocyclohex-1-yl)carbamates and N-(cis(trans)-3,trans(cis)-4-dibromocyclohex-1-yl)-2,2,2-trifluoroacetamides, investigating the effect of the nitrogen protecting group and the relative configuration of the leaving group at C3 and C4 on the outcome of this reaction. We have observed that the sodium hydride-promoted heterocyclization of alkyl N-(cis-3,trans-4-dibromocyclohex-1-yl)carbamates (10, 12, 14, 16, 18) is a convenient method for the synthesis of 7-azabicyclo[2.2.1]heptane derivatives. For instance, the reaction of tert-butyl N-(cis-3,trans-4-dibromocyclohex-1-yl)carbamate (10) with sodium hydride in DMF at room temperature provides 2-bromo-7-[(tert-butoxy)carbonyl]-7-azabicyclo[2.2.1]heptane (2) (52% yield), whose t-BuOK-promoted hydrogen bromide elimination affords 7-[(tert-butoxy)carbonyl]-7-azabicyclo[2.2.1]hept-2-ene (31) in 78% yield, an intermediate in the total synthesis of epibatidine (1). However, the NaH/DMF-mediated heterocyclization of alkyl N-(trans-3,cis-4-dibromocyclohex-1-yl)carbamates (11, 13) is a more structure dependent reaction, where the nucleophilic attack of the oxygen atom of the protecting group controls the outcome of the reaction, giving rise to benzooxazolone and 2-oxa-4-azabicyclo[3.3.1]non-3-ene derivatives, respectively, from low to moderate yields, in complex reaction mixtures. Conversely, the NaH/DMF heterocyclizations of N-(cis-3,trans-4-dibromocyclohex-1-yl)-2,2,2-trifluoroacetamide (40) or N-(trans-3,cis-4-dibromocyclohex-1-yl)-2,2,2-trifluoroacetamide (42) are very clean reactions giving 7-azabicyclo[2.2.1]heptane or 2-oxa-4-azabicyclo[3.3.1]non-3-ene derivatives, respectively, in good yields. Finally, a mechanistic investigation, based on DFT calculations, has been carried out to rationalize the formation of the different adducts.

Influence of PbCl{sub 2} content in PbI{sub 2} solution of DMF on the absorption, crystal phase, morphology of lead halide thin films and photovoltaic performance in planar perovskite solar cells

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

Wang, Mao; Shi, Chengwu, E-mail: shicw506@foxmail.com; Zhang, Jincheng

2015-11-15

In this paper, the influence of PbCl{sub 2} content in PbI{sub 2} solution of DMF on the absorption, crystal phase and morphology of lead halide thin films was systematically investigated and the photovoltaic performance of the corresponding planar perovskite solar cells was evaluated. The result revealed that the various thickness lead halide thin film with the small sheet-like, porous morphology and low crystallinity can be produced by adding PbCl{sub 2} powder into PbI{sub 2} solution of DMF as a precursor solution. The planar perovskite solar cell based on the 300-nm-thick CH{sub 3}NH{sub 3}PbI{sub 3−x}Cl{sub x} thin film by the precursormore » solution with the mixture of 0.80 M PbI{sub 2} and 0.20 M PbCl{sub 2} exhibited the optimum photoelectric conversion efficiency of 10.12% along with an open-circuit voltage of 0.93 V, a short-circuit photocurrent density of 15.70 mA cm{sup −2} and a fill factor of 0.69. - Graphical abstract: The figure showed the surface and cross-sectional SEM images of lead halide thin films using the precursor solutions: (a) 0.80 M PbI{sub 2}, (b) 0.80 M PbI{sub 2}+0.20 M PbCl{sub 2}, (c) 0.80 M PbI{sub 2}+0.40 M PbCl{sub 2}, and (d) 0.80 M PbI{sub 2}+0.60 M PbCl{sub 2}. With the increase of the PbCl{sub 2} content in precursor solution, the size of the lead halide nanosheet decreased and the corresponding thin films gradually turned to be porous with low crystallinity. - Highlights: • Influence of PbCl{sub 2} content on absorption, crystal phase and morphology of thin film. • Influence of perovskite film thickness on photovoltaic performance of solar cell. • Lead halide thin film with small sheet-like, porous morphology and low crystallinity. • Planar solar cell with 300 nm-thick perovskite thin film achieved PCE of 10.12%.« less

Design of an Anticancer Copper(II) Prodrug Based on the Lys199 Residue of the Active Targeting Human Serum Albumin Nanoparticle Carrier.

PubMed

Gou, Yi; Zhang, Yao; Zhang, Zhenlei; Wang, Jun; Zhou, Zuping; Liang, Hong; Yang, Feng

2017-06-05

We not only modified the types and numbers of coordinated ligands in a metal agent to enhance its anticancer activity, but we also designed a metal prodrug based on the N-donor residues of the human serum albumin (HSA) IIA subdomain to improve its delivery efficiency and selectivity in vivo. However, there may be a conflict in simultaneously achieving the two goals because Lys199 and His242 in the IIA subdomain of HSA can replace its two coordinated ligands, which will decrease its anticancer activity relative to the original metal agent. Thus, to improve the delivery efficiency of the metal agent and simultaneously avoid decreasing its anticancer activity in vivo, we decided to develop an anticancer metal prodrug by regulating its pharmacophore ligand so that it would not be displaced by the Lys199 residue of the folic acid (FA)-functionalized HSA nanoparticle (NP) carrier. To this end, we first synthesized two (E)-N'-(5-chloro-2-hydroxybenzylidene)benzohydrazide Schiff base (HL) Cu(II) compounds by designing a second ligand with a different coordinating atom with Cu 2+ /Cu(L)(QL)(Br) [C1, QL = quinolone] and Cu(L)(DMF)(Br) [C2, DMF = N,N-dimethylformamide]. As revealed by the structures of the two HSA complexes, the Cu compounds bind to the hydrophobic cavity in the HSA IIA subdomain. The QL ligand of C1 is replaced by Lys199, which coordinates with Cu 2+ , whereas the DMF ligand of C2 is kept intact and His242 is replaced with Br - of C2 and coordinates with Cu 2+ . The cytotoxicity of the Cu compounds was enhanced by the FA-HSA NPs in the Bel-7402 cells approximately 2-4-fold; however, they raise the cytotoxicity levels in the normal cells in vitro, and the FA-HSA NPs did not. Importantly, the in vivo data showed that FA-HSA-C2 NPs increased selectivity and the capacity to inhibit tumor growth and were less toxic than HSA-C2 NPs and C2. Moreover, C2/HSA-C2 NPs/FA-HSA-C2 NPs induced Bel-7402 cell death by potentially multiple mechanisms.

Roughans Point, Revere, Massachusetts Coastal Flood Protection Study. Volume I. Main Report.

DTIC Science & Technology

1982-12-01

1982 conducted bT, Rusty Iwanowicz , Massachusetts Division of Marine Fisheries, concluded that the shoreline area that would be impacted by the... Iwanowicz , DMF, and Charles Freeman of my staff. In this survey, five test holes were dug seaward of the area of project impact in areas which Mr... Iwanowicz felt would indicate the productivity of the clam flat. Two holes revealed no shellfish, and the best hole produced two razor clams, two

A New Silicon-Containing Bis(Cyanate) Ester Resin with Improved Thermal Oxidation and Moisture Resistance

DTIC Science & Technology

2006-05-23

making it an ideal comparative material. Scheme 1 BnO Br Si R R OYYO Si R R NCO OCN 1. n- BuLi THF/-78 oC 2. Me2SiCl2 1; R = Me, Y= Bn H2...carbonate in DMF) was treated with n- BuLi (15.2 mL, 38 mmol) and allowed to react with stirring for 30 min. This mixture, now heterogeneous, was

Preparation, Characterization, and Energetic Properties of Metallized Nanofibers

DTIC Science & Technology

2013-12-31

applied to a stainless steel needle (17-27 gauge) thereby charging the n AI/PFPE loaded PS/ DMF suspension. The syringe pump is set at a flow rate of...front propagates to the left. rolled to obtain a cylindrical cross section along the length of the fiber. These samples were then placed inside a steel ...occur altering the transJerred mass balance during electro spinning. Fiber Spinning. An in house electrospinning setup in a fume hood is used to

Activation of porous MOF materials

DOEpatents

Hupp, Joseph T; Farha, Omar K

2013-04-23

A method for the treatment of solvent-containing MOF material to increase its internal surface area involves introducing a liquid into the MOF in which liquid the solvent is miscible, subjecting the MOF to supercritical conditions for a time to form supercritical fluid, and releasing the supercritical conditions to remove the supercritical fluid from the MOF. Prior to introducing the liquid into the MOF, occluded reaction solvent, such as DEF or DMF, in the MOF can be exchanged for the miscible solvent.

Activation of porous MOF materials

DOEpatents

Hupp, Joseph T; Farha, Omar K

2014-04-01

A method for the treatment of solvent-containing MOF material to increase its internal surface area involves introducing a liquid into the MOF in which liquid the solvent is miscible, subjecting the MOF to supercritical conditions for a time to form supercritical fluid, and releasing the supercritical conditions to remove the supercritcal fluid from the MOF. Prior to introducing the liquid into the MOF, occluded reaction solvent, such as DEF or DMF, in the MOF can be exchanged for the miscible solvent.

Molecular Weight Measurement of Biobased Furan Polyamides via Non-Aqueous Potentiometric Titration

DTIC Science & Technology

2013-06-01

electromagnetic fields, all titrations were completed in a chemical hood, which acted as a Faraday cage (a shield used to blocks external static and...while using DMF as a solvent. Additionally, no Faraday cage was used in the experimental setup, so the titrations were conducted inside the chemical...monomer was becoming more soluble in glacial acetic acid and the amount of chlorobenzene had less of an effect on the solution properties (i.e

Biobased Carbon Fibers and High-Performance Thermosetting Resins for Use in U.S. Department of Defense Applications

DTIC Science & Technology

2012-06-01

water on the synthesis . bHMF (20.5 g), epichlorohydrin (59.2 g), DMF (30 mL) and benzyl trimethyl ammonium chloride (1.18 g) were mixed and heated up...107  5.2.3  Synthesis of Methacrylated Lignin Model Compounds ..................................108  5.2.4  Monomer and...145  6.2.2  Synthesis of Vanillin-Based Resin ..................................................................146  6.2.3  Resin

Electrospinning of Poly (MMA-CO-Maa) Copolymers And Their Layered Silicate Nanocomposites For Improved Thermal Properties

DTIC Science & Technology

2004-12-01

7518. Ho, B.C., Lee, Y.D. and Chin, W.K., 1992: Thermal Degradation of Polymethacrylic Acid , J. Polym. Sci., Polymer Chemistry, 30, 2389-2397. Lee...AMSRD-ARL-WM-MD Aberdeen Proving Ground, MD 21005-5069 ABSTRACT Copolymers consisting of methyl methacrylate (MMA) and methacrylic acid (MAA...from solution of poly (MMA-co-MAA) copolymer (50/50 weight ratio of MMA and methacrylic acid , MAA) in dimethylformamide (DMF) and the corresponding

Optimization of flavanones extraction by modulating differential solvent densities and centrifuge temperatures.

PubMed

Chebrolu, Kranthi K; Jayaprakasha, G K; Jifon, J; Patil, Bhimanagouda S

2011-07-15

Understanding the factors influencing flavonone extraction is critical for the knowledge in sample preparation. The present study was focused on the extraction parameters such as solvent, heat, centrifugal speed, centrifuge temperature, sample to solvent ratio, extraction cycles, sonication time, microwave time and their interactions on sample preparation. Flavanones were analyzed in a high performance liquid chromatography (HPLC) and later identified by liquid chromatography and mass spectrometry (LC-MS). The five flavanones were eluted by a binary mobile phase with 0.03% phosphoric acid and acetonitrile in 20 min and detected at 280 nm, and later identified by mass spectral analysis. Dimethylsulfoxide (DMSO) and dimethyl formamide (DMF) had optimum extraction levels of narirutin, naringin, neohesperidin, didymin and poncirin compared to methanol (MeOH), ethanol (EtOH) and acetonitrile (ACN). Centrifuge temperature had a significant effect on flavanone distribution in the extracts. The DMSO and DMF extracts had homogeneous distribution of flavanones compared to MeOH, EtOH and ACN after centrifugation. Furthermore, ACN showed clear phase separation due to differential densities in the extracts after centrifugation. The number of extraction cycles significantly increased the flavanone levels during extraction. Modulating the sample to solvent ratio increased naringin quantity in the extracts. Current research provides critical information on the role of centrifuge temperature, extraction solvent and their interactions on flavanone distribution in extracts. Published by Elsevier B.V.

Screening of pesticide residues in honeybee wax comb by LC-ESI-MS/MS. A pilot study.

PubMed

Herrera López, Sonia; Lozano, Ana; Sosa, Alexis; Hernando, M Dolores; Fernández-Alba, Amadeo R

2016-11-01

A developed multi-residue method using microflow-LC-ESI-QqQ-MS provided a wide-scope analysis for medium-polar and polar pesticide residues (120 compounds including breakdown products). Honeybee wax comb samples were extracted using a generic QuEChERS based procedure. Acceptable recoveries at concentration levels of 5 and 50 μg kg(-1) were within the 70-120% range with an associated precision RSD <20%. The LOQ values were mostly 5 μg kg(-1) for almost all pesticides. Aprox. 31 of 120 LC-amenable pesticides tested (25.8%) were detected in a pilot study of 60 samples. Pesticide residues detected using the proposed method were: the breakdown products of amitraz, DMPF and DMF, an acaricide used for Varroa mite control, with a range of concentration from 5 to 464 μg kg(-1) (sum of DMPF + DMF), organophosphate insecticides from 1 to 464 μg kg(-1), acaricides at concentrations > 9 μg kg(-1); fungicides at concentrations ranging from 1 to 23 μg kg(-1.) The number of positive detections due to herbicides was lower as expected and at a lower level of concentration, from 1 to 5.9 μg kg(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

High-Performance Blue-Excitable Yellow Phosphor Obtained from an Activated Solvochromic Bismuth-Fluorophore Metal–Organic Framework

DOE PAGES

Deibert, Benjamin J.; Velasco, Ever; Liu, Wei; ...

2016-06-23

Here, we report the synthesis, structure, and photoluminescence properties of a new bismuth based luminescent metal-organic framework (LMOF). The framework is comprised of a 9-coordinated Bi 3+ building unit and 4', 4''', 4''''', 4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis([1,1'-biphenyl]-4-carboxylic acid) (H 4tcbpe) organic linker, which has strong yellow aggregation induced emission (AIE). The structure can be viewed as two interpenetrated 4,4-anionic nets that are stabilized by K + ions forming one-dimensional helical inorganic chains by connecting bismuth nodes through shared oxygen bonds. The as-made LMOF has a bluish emission centered at 459 nm with an internal quantum yield of 57% when excited at 360 nm.more » The emission properties of the LMOF were found to be highly solvochromic with respect to DMF. Upon partial solvent removal, the framework undergoes significant red-shifting to a greenish emission centered at 500 nm. Complete removal of DMF results in additional red-shifting fluorescence coupled with structural changes. The resulting material has strong blue-excitable (455 nm) yellow emission centered at 553 nm, with a quantum yield of 74%, which is maintained after heating in air for 5 days at 90°C. This is the second highest quantum yield value for blue-excited yellow emission among all reported LMOFs.« less

Effects of fluoridated drinking water on dental caries in Australian adults.

PubMed

Slade, G D; Sanders, A E; Do, L; Roberts-Thomson, K; Spencer, A J

2013-04-01

Systematic reviews produce conflicting conclusions regarding dental caries-preventive effects of water fluoridation in adults. The authors investigated the relationship using data from the nationally representative 2004-2006 Australian National Survey of Adult Oral Health. Effects were compared between the pre-fluoridation cohort born before 1960 (n = 2,270) and the cohort born between 1960 and 1990 (n = 1,509), when widespread implementation of fluoridation increased population coverage from < 1% to 67%. Residential history questionnaires determined the percentage of each person's lifetime exposed to fluoridated water. Examiners recorded decayed, missing, and filled teeth (DMF-Teeth) and decayed and filled tooth surfaces (DF-Surfaces). Socio-demographic and preventive dental behaviors were included in multivariable least-squares regression models adjusted for potential confounding. In fully adjusted models, > 75% of lifetime exposure to fluoridation relative to < 25% of lifetime exposure was associated with 11% and 10% fewer DMF-Teeth in the pre-1960 (p < .0001) and 1960-1990 cohorts (p = .018), respectively. Corresponding reductions in DF-Surfaces were 30% (p < .001) and 21% (p < .001). Findings for intermediate fluoridation exposure suggested a dose-response relationship. Results were consistent in sensitivity analyses accounting for missing data. In this nationally representative sample of Australian adults, caries-preventive effects of water fluoridation were at least as great in adults born before widespread implementation of fluoridation as after widespread implementation of fluoridation.

N-nitrosodimethylamine formation upon ozonation and identification of precursors source in a municipal wastewater treatment plant.

PubMed

Sgroi, Massimiliano; Roccaro, Paolo; Oelker, Gregg L; Snyder, Shane A

2014-09-02

Ozone doses normalized to the dissolved organic carbon concentration were applied to the primary influent, primary effluent, and secondary effluent of a wastewater treatment plant producing water destined for potable reuse. Results showed the most N-Nitrosodimethylamine (NDMA) production from primary effluent, and the recycle streams entering the primary clarifiers were identified as the main source of NDMA precursors. The degradation of aminomethylated polyacrylamide (Mannich) polymer used for sludge treatment was a significant cause of precursor occurrence. A strong correlation between NDMA formation and ammonia concentration was found suggesting an important role of ammonia oxidation on NDMA production. During ozonation tests in DI water using dimethylamine (DMA) as model precursor, the NDMA yield significantly increased in the presence of ammonia and bromide due to the formation of hydroxylamine and brominated nitrogenous oxidants. In addition, NDMA formation during ozonation of dimethylformamide (DMF), the other model precursor used in this study, occurred only in the presence of ammonia, and it was attributable to the oxidation of DMF by hydroxyl radicals. Filtered wastewater samples (0.7 μm) produced more NDMA than unfiltered samples, suggesting that ozone reacted with dissolved precursors and supporting the hypothesis of polymer degradation. Particularly, the total suspended solids content similarly affected NDMA formation and the UV absorbance decrease during ozonation due to the different ozone demand created in filtered and unfiltered samples.

Diffuse myocardial fibrosis among healthy pediatric heart transplant recipients: Correlation of histology, cardiovascular magnetic resonance, and clinical phenotype.

PubMed

Feingold, Brian; Salgado, Cláudia M; Reyes-Múgica, Miguel; Drant, Stacey E; Miller, Susan A; Kennedy, Mark; Kellman, Peter; Schelbert, Erik B; Wong, Timothy C

2017-08-01

Fibrosis is commonly described in heart allografts lost late after transplantation. CMR-derived ECV is a validated measure of DMF in native adult hearts that may predict heart failure and mortality. We explored associations of ECV with histologic myocardial fibrosis and clinical features after pediatric heart transplantation. Twenty-five recipients (7.0±6.3 years at transplant and 10.7±6.5 years post-transplant) were prospectively recruited for CMR and BNP measurement at the time of surveillance biopsy. All had normal ejection fractions and lacked heart failure symptoms. Fibrosis was quantified on biopsy after picrosirius red staining as CVF. ECV was quantified using contemporaneous hematocrit on basal and mid-short-axis slices. ECV was moderately correlated with CVF (r=.47; P=.019). We found no associations of ECV with hemodynamics, ischemic time, time since transplantation, or number of prior biopsies or acute rejections. Compared to healthy non-transplant controls, there was no significant difference in ECV (25.1±3.0 vs 23.7±2.0%, P=.09). Log-transformed BNP was correlated with ECV (recipients: r=.46, P=.02; recipients and controls: r=.45, P=.006). These findings suggest ECV quantifies DMF and relates to biological indicators of cardiac function after pediatric heart transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Syntheses, topological analyses, and NLO-active properties of new Cd(II)/M(II) (M = Ca, Sr) metal-organic frameworks based on R-isophthalic acids (R = H, OH, and t-Bu).

PubMed

Lin, Jian-Di; Wu, Shu-Ting; Li, Zhi-Hua; Du, Shao-Wu

2010-11-28

Solvothermal syntheses of Cd(NO(3))(2)·4H(2)O and R-isophthalic acids (R = H, OH and t-Bu) in the presence of Ca(II) or Sr(II) lead to four new three-dimensional Cd(II)/Ca(II) or Cd(II)/Sr(II) heterometallic frameworks: [CdCa(m-BDC)(2)(DMF)(2)] (1), [CdSr(2)(m-BDC)(2)(NO(3))(2)(DMF)(4)] (2), [CdCa(OH-m-BDC)(2)(H(2)O)(2)]·2Me(2)NH (3), and (Me(2)NH(2))(2)[Cd(2)Ca(Bu(t)-m-BDC)(4)] (4) (m-H(2)BDC = isophthalate, OH-m-H(2)BDC = 5-hydroxyisophthalate and Bu(t)-m-H(2)BDC = 5-butylisophthalate). All of these compounds except for 4 crystallize in acentric (or chiral) space groups and the bulk materials for 1 and 3 display strong powder SHG efficiencies, approximately 1.54 and 2.31 times than that of a potassium dihydrogen phosphate (KDP) powder. Topological analyses show that 1 and 2 have structures with sxb and dia topologies, respectively, while both 3 and 4 exhibit pcu topological nets when the metal carboxylate clusters are viewed as nodes. The fluorescence properties and thermal stabilities for these compounds are also investigated.

The Role of Fungi in the Etiology of Multiple Sclerosis

PubMed Central

Benito-León, Julián; Laurence, Martin

2017-01-01

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system. Infectious triggers of MS are being actively investigated. Substantial evidence supports the involvement of the Epstein-Barr virus (EBV), though other viruses, bacteria, protists, and fungi are also being considered. Many links between fungi and diseases involving chronic inflammation have been found recently. Evidence linking MS and fungi is reviewed here. The HLA-DRB1*15 allele group is the most important genetic risk factor of MS, and is a risk factor in several other conditions linked to fungal infections. Many biomarkers of MS are consistent with fungal infections, such as IL-17, chitotriosidase, and antibodies against fungi. Dimethyl fumarate (DMF), first used as an industrial fungicide, was recently repurposed to reduce MS symptoms. Its mechanisms of action in MS have not been firmly established. The low risk of MS during childhood and its moderate association with herpes simplex virus type 2 suggest genital exposure to microbes (including fungi) should be investigated as a possible trigger. Molecular and epidemiological evidence support a role for infections such as EBV in MS. Though fungal infections have not been widely studied in MS, many lines of evidence are consistent with a fungal etiology. Future microbiome and serological studies should consider fungi as a possible risk factor for MS, and future clinical studies should consider the effect of fungicides other than DMF on MS symptoms. PMID:29085329

Electrospinning processed nanofibrous TiO2 membranes for photovoltaic applications

NASA Astrophysics Data System (ADS)

Onozuka, Katsuhiro; Ding, Bin; Tsuge, Yosuke; Naka, Takayuki; Yamazaki, Michiyo; Sugi, Shinichiro; Ohno, Shingo; Yoshikawa, Masato; Shiratori, Seimei

2006-02-01

We have recently fabricated dye-sensitized solar cells (DSSCs) comprising nanofibrous TiO2 membranes as electrode materials. A thin TiO2 film was pre-deposited on fluorine doped tin oxide (FTO) coated conducting glass substrate by immersion in TiF4 aqueous solution to reduce the electron back-transfer from FTO to the electrolyte. The composite polyvinyl acetate (PVac)/titania nanofibrous membranes can be deposited on the pre-deposited thin TiO2 film coated FTO by electrospinning of a mixture of PVac and titanium isopropoxide in N,N-dimethylformamide (DMF). The nanofibrous TiO2 membranes were obtained by calcining the electrospun composite nanofibres of PVac/titania as the precursor. Spectral sensitization of the nanofibrous TiO2 membranes was carried out with a ruthenium (II) complex, cis-dithiocyanate-N,N'-bis(2,2'-bipyridyl-4,4'-dicarboxylic acid) ruthenium (II) dihydrate. The results indicated that the photocurrent and conversion efficiency of electrodes can be increased with the addition of the pre-deposited TiO2 film and the adhesion treatment using DMF. Additionally, the dye loading, photocurrent, and efficiency of the electrodes were gradually increased by increasing the average thickness of the nanofibrous TiO2 membranes. The efficiency of the fibrous TiO2 photoelectrode with the average membrane thickness of 3.9 µm has a maximum value of 4.14%.

Preparation and characterization of nanocomposite polymer electrolytes poly(vinylidone fluoride)/nanoclay

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

Rahmawati, Suci A.; Sulistyaningsih,; Putro, Alviansyah Z. A.

2016-02-08

Polymer electrolytes are defined as semi solid electrolytes used as separator in lithium ion battery. Separator used as medium for transfer ions and to prevent electrical short circuits in battery cells. To obtain the optimal battery performance, separator with high porosity and electrolyte uptake is required. This can reduce the resistance in the transfer of ions between cathode and anode. The main objective of this work is to investigate the impact of different solvent (Dimethyl acetamide (DMAc), N-methyl-2-pyrrolidone (NMP) and dimethyl formamide (DMF)), pore forming agent poly(vinylpyrolidone) (PVP) and nanoclay as filler in addition of membrane using phase inversion methodmore » on the morphology, porosity, electrolyte uptake and degree of crystallinity. The membrane was prepared by the phase inversion method by adding PVP and Nanoclay using different solvents. The phase inversion method was prepared by dissolving Nanoclay and PVP in solvent for 1-2 hours, and then add the PVDF with stirring for 4 hours at 60°C. The membranes were characterized by porosity test, electrolyte uptake test, scanning electron microscope (SEM), and X-ray diffraction (XRD). The results showed that DMAc as solvent gives the highest value of porosity and electrolyte uptake. The addition of nanoclay and PVP enlarge the size of the pores and reduce the degree of crystallinity. So, the usage of DMAc as solvent is better than NMP or DMF.« less

[Two-photon up-conversion fluorescence of a neodymium organic framework Nd(BTC)].

PubMed

Xu, Hui; Jin, Run-zhi; Wu, Chun-yang; Yang, Yu; Qian, Guo-dong

2008-08-01

In the present work, a neodymium organic framework Nd(BTC) was synthesized by the solvothermal reaction of Nd(NO3)3 x 5H2O and H3BTC (BTC = 1,3,5-benzenetricarboxylate) in mixed solvents of DMF, ethanol and water, and was identified by elemental analysis. This MOF complex was characterized using X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TGA-DSC) analysis, UV-visible absorption spectra and fluorescence spectra. This polycrystalline powder lost DMF and H2O when heated to 120 degrees C, then remained stable till the temperature reached 500 degrees C. Near infrared fluorescence at 1064 nm due to the 4 F3/2--> 4 I11/2 transition of Nd3+ ions was exhibited when excited by 808 nm laser beam. It was also been found that up-conversion fluorescence of Nd(BTC) peaked at about 450 nm due to 2 D5/2 -->4 I11/2 transition of Nd3+ ions can be observed under the excitation of a 580 nm laser line. The mechanism of the up-conversion fluorescence of Nd(BTC) at around 450 nm under the excitation of 580 nm laser can be ascribed to both excited-state absorption and energy transfer up-conversion. This result indicated that such MOF can be employed as an up-conversion luminescence material in many potential application areas such as bio-labeling and fluorescence image.

A novel 4-phenyl amino thiourea derivative designed for real-time ratiometric-colorimetric detection of toxic Pb2.

PubMed

Guang, Yi S; Ren, Xia; Zhao, Shuang; Yan, Quan Z; Zhao, Gang; Xu, Yao H

2018-05-12

The objective of this study was to develop a ratiometric and colorimetric organic sensor for Pb 2+ detection in environmental samples. A new probe 4-phenyl amino thiourea (PAT) was designed and synthesized using hydrazine hydrate and phenyl isothiocyanate as raw materials. After its structure was characterized and confirmed, its UV-vis spectral property was investigated in detail. PAT possesses a specifically real-time, ratiometric and colorimetric response to Pb 2+ in dimethyl formamide (DMF)/H 2 O (v/v = 9:1, pH = 7.0) within 18.0 s. There was little interference in the presence of some other common metal ions, such as Fe 3+ , Cd 2+ , Zn 2+ , Mg 2+ , Cr 3+ , Ca 2+ , Ba 2+ , Sn 2+ , Na + , Mn 2+ , Hg 2+ , and Pb 2+ . Under the optimized conditions (DMF/H 2 O with v/v of 9:1, c PAT = 1.0 × 10 -3 mol·L -1 , pH = 7.0), the present sensor PAT was successfully applied for Pb 2+ determination in environmental water samples with satisfied recoveries (83.0%-106.0%) and analytical precision (≤7.2%). The recognition mechanism was confirmed to form a stable 1:1 six-member ring complex between the target dye and Pb 2+ with a coordination constant of 4.96 × 10 4 .

Instability analysis of cosmic viscoelastic gyro-gravitating clouds in the presence of dark matter

NASA Astrophysics Data System (ADS)

Karmakar, Pralay Kumar; Das, Papari

2017-08-01

A classical formalism for the weakly nonlinear instability analysis of a gravitating rotating viscoelastic gaseous cloud in the presence of gyratory dark matter is presented on the cosmic Jeans flat scales of space and time. The constituent neutral gaseous fluid (NGF) and dark matter fluid (DMF) are inter-coupled frictionally via mutual gravity alone. Application of standard nonlinear perturbation techniques over the complex gyro-gravitating clouds results in a unique conjugated pair of viscoelastic forced Burgers (VFB) equations. The VFB pair is conjointly twinned by correlational viscoelastic effects. There is no regular damping term here, unlike, in the conventional Burgers equation for the luminous (bright) matter solely. Instead, an interesting linear self-consistent derivative force-term naturalistically appears. A numerical illustrative platform is provided to reveal the micro-physical insights behind the weakly non-linear natural diffusive eigen-modes. It is fantastically seen that the perturbed NGF evolves as extended compressive solitons and compressive shock-like structures. In contrast, the perturbed DMF grows as rarefactive extended solitons and hybrid shocks. The latter is micro-physically composed of rarefactive solitons and compressive shocks. The consistency and reliability of the results are validated in the panoptic light of the existing reports based on the preeminent nonlinear advection-diffusion-based Burgers fabric. At the last, we highlight the main implications and non-trivial futuristic applications of the explored findings.

Significant Enhancement in the Thermoelectric Properties of PEDOT:PSS Films through a Treatment with Organic Solutions of Inorganic Salts.

PubMed

Fan, Zeng; Du, Donghe; Yu, Zhimeng; Li, Pengcheng; Xia, Yijie; Ouyang, Jianyong

2016-09-07

Conducting polymers have promising thermoelectric application because they have many advantages including abundant elements, mechanical flexibility, and nontoxicity. The thermoelectric properties of conducting polymers strongly depend on their chemical structure and microstructure. Here, we report a novel and facile method to significantly enhance the thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) films through a treatment with organic solutions of inorganic salts. N,N-Dimethylformamide (DMF) and a common inorganic salt like zinc chloride (ZnCl2) are used as the solvent and solute of the solutions, respectively. The treatments can significantly increase both the Seebeck coefficient and electrical conductivity of the PSS films. The thermoelectric properties of the PSS films are sensitive to the experimental conditions, such as the salt concentration, treatment temperature, and the cation of the salts. After treatment at the optimal experimental conditions, the PSS films can exhibit a Seebeck coefficient of 26.1 μV/K and an electrical conductivity of over 1400 S/cm at room temperature. The corresponding power factor is 98.2 μW/(m·K(2)). The mechanism for the enhancement in the thermoelectric properties is attributed to the segregation of some PSSH chains from PSS and the conformation change of PEDOT chains as a result of the synergetic effects of inorganic salts and DMF.