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Sample records for comparative histomorphometric study

  1. Comparative Evaluation of Two Types of Immediately Loaded Implants Using Biomechanical and Histomorphometric Tests: An Animal Case Study

    PubMed Central

    Rismanchian, Mansour; Movahedian, Bijan; Khalighinejad, Navid; Badrian, Hamid; Mohammad Razavi, Sayed; Nekouie, Afsaneh

    2012-01-01

    Introduction. In order to minimize the required time to regain esthetic and function, immediately loaded implants were suggested. The aim of this study was to comparatively evaluate the Nisastan and XIve implants using biomechanical and histomorphometric tests. Materials and Methods. In this experimental study, 6 Nisastan one-piece immediately loaded screw type implant (OPILS) and 6 Xive implants with 3.4 mm diameter and 11 mm long were used. The implants were immediately loaded with temporary coating. After three months, the torque required to break bone-implant contact was measured and was recorded. All implants were extracted with surrounding bone and histologically were evaluated. The data were inputted into the SPSS 11.5 to run student T-test statistical analyses (α = 0.05). Results. The success rates of both types of implants was 100%, and none of them failed due to mobility or bone loss. The mean removal torque value (RTV) was 142.08 and 40 N/Cm for Xive and Nisastan implants, respectively, and their RTVs showed a significant difference between two mentioned implants (P = 0.004). None of the histomorphometric values showed significant differences between the two implants (P > 0.05). Discussion. both systems have the capability to induce osseointegration under immediate loads but that Xive implants showed higher capability for bone contact. PMID:22852091

  2. Histological and histomorphometrical comparative study of β-tricalcium phosphate block grafts and periosteal expansion osteogenesis for alveolar bone augmentation.

    PubMed

    Yamauchi, K; Takahashi, T; Funaki, K; Hamada, Y; Yamashita, Y

    2010-10-01

    This study evaluated local tissue reaction around the β-tricalcium phosphate (β-TCP) block and compared results with β-TCP block grafting and periosteal expansion osteogenesis (PEO). The mandibular premolars were extracted from five dogs and buccal corticotomy was performed. Narrow alveolar ridge models were created at 4 weeks. The β-TCP block graft, such as veneer graft, was used on the right side and PEO using β-TCP block on the left side. Changes of alveolar width, histological findings and histomorphometrical analysis were evaluated. There were no problems with materials at any of the sites at any time. In both groups, the width increased after surgery and results were stable 8 weeks after surgery. Newly formed bone tissue was observed inside the β-TCP block in both sides. Histological findings differed especially at the division between mandibular bone and β-TCP block. Histomorphometric analyses revealed that β-TCP had been absorbed (mean decrease 28%) and new bone had formed (mean increase 43%) at 8 weeks postoperatively on both sides. The β-TCP block worked as a space-maker under the soft tissue, including the periosteum, and acted as a substitute for original bone. This bone substitute was effective material for bone augmentation in both methods. PMID:20615666

  3. Histomorphometric study to compare histological changes between oral squamous cell carcinoma and apparently normal adjacent oral mucosa.

    PubMed

    Babji, Deepa V; Kale, Alka D; Hallikerimath, Seema R; Kotrashetti, Vijayalakshmi S

    2015-03-01

    Despite the advances in surgery, radiotherapy and chemotherapy the annual death for oral squamous cell carcinoma (OSCC) is rising rapidly. The carcinoma has propensity to develop in a field of cancerization. Clinically may it be apparently normal mucosa (ANM) adjacent to squamous cell carcinoma which harbours certain discrete molecular alteration which ultimately reflects in cellular morphology. Hence the aim of the study is to assess histomorphometric changes in ANM adjacent to OSCC. A prospective study was done on 30 each of histologically diagnosed cases OSCC, ANM at least 1 cm away from OSCC, and normal oral mucosa (NOM). Cellular and nuclear morphometric measurements were assessed on hematoxylin and eosin sections using image analysis software. Statistical analysis was done using analysis of variance test and Tukey's post hoc test. The present study showed significant changes in cellular and nuclear area in superficial and invasive island of OSCC compared to ANM. The basal cells of ANM showed significant decrease in cellular and nuclear areas and nuclear cytoplasmic ratio when compared to NOM. Histomorphometry definitely can differentiate OSCC form ANM and NOM. The basal cells of ANM showed significant alterations in cellular area, nuclear area and nuclear cytoplasmic area when compared to NOM suggesting change in the field and have high risk of malignant transformation. These parameters can be used as indicator of field cancerization. PMID:25621249

  4. Maxillary sinus floor augmentation on humans: Packing simulations and 8 months histomorphometric comparative study of anorganic bone matrix and β-tricalcium phosphate particles as grafting materials

    PubMed Central

    Martinez, A.; Franco, J.; Saiz, E.; Guitian, F.

    2011-01-01

    The present study compares the behaviour of an anorganic bone matrix material and a synthetic β-Tricalcium phosphate employed as grafting materials in a sinus floor augmentation two step protocol in humans. In order to estimate the initial occupation level for the two materials, an ‘in vitro’ simulation has been performed to analyse macroporosity created due to particle packing in terms of porosity and interparticle distances. Grafting in the sinus floor augmentation was performed by filling the defects only with pure grafting materials without autogenous bone addition. The new-bone generated is 100% based on the osteoconductive properties of the grafted materials in contact with physiological fluids. The implants were placed 8 months after the grafting procedure. All the implanted positions were biopsied and embedded in methacrylate resin. Histomorphometric analyses were done over thin film undecalcified sections. Packing simulations allow establishing a comparison of the resorbed volumes related to the initial occupancy of the grafting materials inside the defect. The nature of this interconnected pore network is very alike for either material so new-bone generated was similar (~35 vol.%). PMID:21625341

  5. Comparative study of the effects of laser photobiomodulation and extract of Brassica oleracea on skin wounds in wistar rats: A histomorphometric study.

    PubMed

    Gonçalves, Reggiani Vilela; Sarandy, Mariáurea Matias; da Matta, Sérgio Luis Pinto; Novaes, Rômulo Dias; Pinto, Marcus Vinicius de Mello

    2013-10-01

    The objective of this study was to investigate the effect of a photobiomodulation laser and Brassica oleracea on tissue morphology in skin wounds. The parameters analyzed were type I and III collagen fibers, and thickness and surface density of the epithelial tissue, as well as how quickly the wound closed. Five skin wounds 12mm in diameter were made on the backs of the animals, which were randomized into four groups (8 animals each). Saline Group: 0.9% saline solution; Ointment Group (extract of Cabbage, B. oleracea, 10% lanolin); Balsam Group (10% glycolic extract of B. oleracea emulsion oil); L60 Group (laser GaAsAl 60J/cm(2)). The applications were made daily during a 20-day treatment, and every 4 days tissue from different wounds was removed. The reduction in the size of the wounds on the 4th, 8th, 12th and 16th days was significantly greater in the treated groups compared to the control group. At all the time points analyzed, there was a greater proportion of collagen in the Balsam and L60 groups (p<0.05). There was also a greater proliferation of epithelial cells in the L60 and Balsam groups after 20 days of treatment (p<0.05). The healing extract and laser 60j/cm(2) exerted a great effect on collagen proliferation in stimulating scar tissue maturation. PMID:23968696

  6. Comparing the TiOblast and Osseospeed surfaces. Histomorphometric and histological analysis in humans

    PubMed Central

    ROCCI, M.; ROCCI, A.; MARTIGNONI, M.; ALBREKTSSON, T.; BARLATTANI, A.; GARGARI, M.

    2008-01-01

    SUMMARY The aim of the present study was to compare two implant surfaces, the TiOblast (Astra Tech) surface, manufactured by blasting the surface and already present in literature and the Osseospeed (Astra Tech) surface, manufactured by blasting and treating the surface with fluoride ions and recently launched onto the market with the modified surfaces of the latest generation. This study is part of a more extensive research project whose protocol required the insertion of 10 couples of implants; thus in the present discussion partial data are being taken into consideration, with an eye at collecting more data in the future, regarding both microscopy and histomorphometric histological analysis on 5 couples of implants. The purpose of the study is to investigate how the modified surfaces of the latest generation can guarantee a greater osseointegration both from a qualitative and quantitative level compared to the surfaces presently used and that they may represent the first example of “bioactivity”, that is, an active interaction with the processes of new bone formation and tissue healing. PMID:23285334

  7. Nano-crystalline diamond-coated titanium dental implants - a histomorphometric study in adult domestic pigs.

    PubMed

    Metzler, Philipp; von Wilmowsky, Cornelius; Stadlinger, Bernd; Zemann, Wolfgang; Schlegel, Karl Andreas; Rosiwal, Stephan; Rupprecht, Stephan

    2013-09-01

    Promising biomaterial characteristics of diamond-coatings in biomedicine have been described in the literature. However, there is a lack of knowledge about implant osseointegration of this surface modification compared to the currently used sandblasted acid-etched Ti-Al6-V4 implants. The aim of this study was to investigate the osseointegration of microwave plasma-chemical-vapour deposition (MWP-CVD) diamond-coated Ti-Al6-V4 dental implants after healing periods of 2 and 5 months. Twenty-four MWP-CVD diamond-coated and 24 un-coated dental titanium-alloy implants (Ankylos(®)) were placed in the frontal skull of eight adult domestic pigs. To evaluate the effects of the nano-structured surfaces on bone formation, a histomorphometric analysis was performed after 2 and 5 months of implant healing. Histomorphometry analysed the bone-to-implant contact (BIC). No significant difference in BIC for the diamond-coated implants in comparison to reference implants could be observed for both healing periods. Scanning electron microscopy revealed an adequate interface between the bone and the diamond surface. No delamination or particle-dissociation due to shearing forces could be detected. In this study, diamond-coated dental titanium-alloy implants and sandblasted acid-etched implants showed a comparable degree of osseointegration. PMID:23266005

  8. Computerized histomorphometric study of the splenic collagen polymorphism: A control-tissue for polarization microscopy.

    PubMed

    Alves, Antoine; Gritsch, Kerstin; Sirieix, Camille; Drevon-Gaillot, Elodie; Bayon, Yves; Clermont, Gaëlle; Boutrand, Jean-Pierre; Grosgogeat, Brigitte

    2015-10-01

    Previous articles have pointed out the presence of type III collagen within the extracellular structure of the parenchymatous organs. This study aimed to quantitatively characterize the collagen polymorphism at the capsule and parenchymal trabeculae of the largest lymphoid organ of the body i.e., the spleen, in mouse, rat, and rabbit models. Following a Picrosirius Red-Polarization procedure and computer assisted image analysis of paraffin sections, the results showed (1) a predominant and significantly higher amount of type III collagen in the trabeculae area compared to the capsule area in the three species, (2) no statistical difference among the three species concerning the parenchymal collagen polymorphism or the type I/type III collagen ratio, (3) a heterogeneous type I/type III collagen ratio varying from 0.86 (mouse) to 6.62 (rabbit) in the fibromuscular capsule region. A qualitative analysis corroborated these histomorphometric results. In conclusion, the spleen may be used as (1) a control tissue to qualitatively visualize type I and III collagen under polarization microscopy and to validate the quality of PSR staining (2) an aid to accurately calibrate the angle of polarization before quantitative measurements of type I and type III collagen. Among the studied species, the rabbit spleen appeared to be the most appropriate control tissue as it showed the highest amount of type I collagen in the capsule and a similarly high amount of type III collagen in the parenchymal trabeculae. PMID:26238067

  9. C-arm CT for histomorphometric evaluation of lumbar spine trabecular microarchitecture: a study on anorexia nervosa patients.

    PubMed

    Phan, C M; Khalilzadeh, O; Dinkel, J; Wang, I S; Bredella, M A; Misra, M; Miller, K K; Klibanski, A; Gupta, R

    2013-07-01

    Bone histomorphometry measurements require high spatial resolution that may not be feasible using multidetector CT (MDCT). This study evaluated the trabecular microarchitecture of lumbar spine using MDCT and C-arm CT in a series of young adult patients with anorexia nervosa (AN). 11 young females with AN underwent MDCT (anisotropic resolution with a slice thickness of ~626 μm) and C-arm CT (isotropic resolution of ~200 µm). Standard histomorphometric parameters the of L1 vertebral body, namely the apparent trabecular bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN) and trabecular separation (TbSp), were analysed using MicroView software (GE Healthcare, Piscataway, NJ). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Trabecular parameters derived from MDCT and C-arm CT were compared, and their association with BMD parameters was evaluated. Histomorphometric parameters derived from C-arm CT, namely TbTh, TbN and TbSp, were significantly different from the corresponding MDCT parameters. There were no significant correlations between C-arm CT-derived parameters and the corresponding MDCT-derived parameters. C-arm CT-derived parameters were significantly (p<0.001) correlated with anteroposterior L1 spine BMD and Z-scores: TbTh (r=0.723, r=0.744, respectively), TbN (r=-0.720, r=-0.712, respectively) and TbSp (r=0.656, r=0.648, respectively). BV/TV, derived from C-arm CT, was significantly associated with body mass index (r=0.636) and ideal body weight (r=0.730) (p<0.05). These associations were not present in MDCT-derived parameters. This study suggests that the spatial resolution offered by C-arm CT more accurately captures the histomorphometric parameters of trabecular morphology than MDCT in patients with AN. PMID:23640801

  10. Histomorphometric study of alveolar bone healing in rats fed a boron-deficient diet.

    PubMed

    Gorustovich, Alejandro A; Steimetz, Tammy; Nielsen, Forrest H; Guglielmotti, María B

    2008-04-01

    Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. The first lower right molar of weanling Wistar rats was extracted under anesthesia. The animals were divided into two groups: +B (adequate; 3 mg B/kg diet), and -B (boron-deficient; 0.07 mg/kg diet). The animals in both groups were killed in groups of 10 at 7 and 14 days after surgery. The guidelines of the NIH for the care and use of laboratory animals were observed. The mandibles were resected, fixed, decalcified, and embedded in paraffin. Buccolingually oriented sections were obtained at the level of the mesial alveolus and used for histometric evaluations. Total alveolar volume (TAV) and trabecular bone volume per total volume (BV/TV) in the apical third of the alveolus were determined. Percentages of osteoblast surface (ObS), eroded surface (ES), and quiescent surface (QS) were determined. No statistical significant differences in food intake and body weight were observed. Histomorphometric evaluation found -B rats had 36% and 63% reductions in BV/TV at 7 and 14 days, respectively. When compared with +B rats, -B rats had significant reductions (57% and 87%) in ObS concomitantly with increases (120% and 126%) in QS at 7 and 14 days, respectively. The findings show that boron deficiency results in altered bone healing because of a marked reduction in osteogenesis. PMID:18361451

  11. A histomorphometric study of bone changes in thyroid dysfunction in rats.

    PubMed

    Allain, T J; Thomas, M R; McGregor, A M; Salisbury, J R

    1995-05-01

    Clinical studies in thyrotoxicosis reveal a state of high bone turnover leading, eventually, to osteoporosis. Recently there has been concern that thyroxine (T4) treatment may have a similar effect on bone. Rat models have been used to study the effects of T4 on bone, but the majority of studies have looked at the effects of T4 after only 3 weeks of treatment. The aim of this study was to evaluate histomorphometric changes in rats after 12 weeks of thyroxine overtreatment or 12 weeks of hypothyroidism compared with untreated control animals. Animals received either T4 200 micrograms/kg per day, 0.1% propylthiouracil, or vehicle for 12 weeks. Tetracycline was administered 1 week and 3 weeks prior to killing. Iliac crest bone was used for histomorphometry. Serum T4 measurements (taken at killing) confirmed hyper- and hypothyroidism in the appropriate animal groups (between group difference p < 0.001 by ANOVA). In hyperthyroid animals there was an increase in mineral apposition rate (MAR; 0.94 vs. 0.59 microns/day, p < 0.001) and mineral formation rate (MFR/BS; 0.24 vs. 0.12 x 10(-2) micron3/micron2 per day, p < 0.001) and a slight increase in eroded surfaces (ES/BS%; 1.54 vs. 1.36, p < 0.05) compared with controls, consistent with previous in vitro and in vivo observations. In hypothyroid rats there was a marked reduction in osteoid surfaces (OS/BS%; 1.7 vs. 24.8, p < 0.001) and MAR (0.3 vs. 0.59 micrograms/day, p < 0.001), a reduction in ES/BS% (0.51 vs. 1.36, p < 0.05), and an increase in cancellous bone volume (BV/TV%; 30.29 vs. 19.6, p < 0.05), suggesting that thyroid hormones are a requirement for normal bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7654465

  12. Histological and histomorphometric study using an ultrasonic crestal sinus grafting procedure. A multicenter case study

    PubMed Central

    Wainwright, Marcel; Pérez-Dorao, Beatriz; Serrera-Figallo, María-Angeles; Gutierrez-Perez, José-Luis; Troedhan, Angelo; Kurrek, Andreas

    2016-01-01

    Background The aim of this study was to evaluate the efficacy of a hydrodynamic ultrasonic driven transcrestal sinus grafting procedure (Intralift ®, Acteon Company, Bordeaux, France) and the use of a bovine high temperature sintered grafting material in sinus sites with less than 5 mm remaining bone height with no additional autogenous bone in order to create a sufficient recipient site for implants. Material and Methods 12 patients (16 sinus) in this multicenter case study were included. Using a crestal approach, bone under the sinus was prepared with ultrasonic tips until the Schneiderian membrane was reached. With a trumpet shaped instrument, the Schneiderian membrane was elevated. In the new created subantral space a high temperature sintered bovine grafting material was introduced (Bego Oss, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany). After 6 months biopsies were taken with a trephine bur and histologies were generated following histomorphometric analysis. Results The results showed new vital bone in average of 33.4% ± 17.05%, and 43.6% ± 16.70 of bone substitute material. No signs of abnormal inflammation were observed. Conclusions This procedure (Intralift ®) allows, using a bovine material with no additional autogenous bone, new bone formation in the sinus in order to allow place implant subantraly. Key words:Bone regeneration, sinus, intralift ®, xenogenic bone graft PMID:26946203

  13. Socket Preservation Therapy with Acellular Dermal Matrix and Mineralized Bone Allograft After Tooth Extraction in Humans: A Clinical and Histomorphometric Study.

    PubMed

    Fernandes, Patricia Garani; Muglia, Valdir Antonio; Reino, Danilo Maeda; Maia, Luciana Prado; de Moraes Grisi, Marcio Fernando; de Souza, Sergio Luís; Taba, Mario; Palioto, Daniela Bazan; de Almeida, Adriana G; Novaes, Arthur Belém

    2016-01-01

    The aim of this study was to analyze through clinical and histomorphometric parameters the use of acellular dermal matrix (ADM) with or without mineralized bone allograft (AB) on bone formation in human alveoli after a 6- to 8-month healing period. A total of 19 patients in need of extraction of the maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus AB) or to the control group (ADM only). Clinical and histomorphometric measurements and histologic analysis were recorded 6 to 8 months after ridge preservation procedures. Clinical parameters and amount of mineralized and nonmineralized tissue were measured and analyzed. In the clinical measurements, the test group showed reduced bone loss in the buccopalatal dimension after 6 to 8 months (intragroup analysis P < .01). Histologic findings showed higher percentages of mineralized tissue and lower percentages of nonmineralized tissue in the test group when compared with the control group (P < .05). In this randomized controlled clinical and histomorphometric study in humans, acellular dermal matrix in association with mineralized bone allograft reduced alveolar bone loss in the anterior maxillae both in height and width after a follow-up period of 6 to 8 months. PMID:26901306

  14. Adjunctive effect of antimicrobial photodynamic therapy in induced periodontal disease. Animal study with histomorphometrical, immunohistochemical, and cytokine evaluation.

    PubMed

    de Oliveira, Paula Gabriela Faciola Pessôa; Silveira E Souza, Adriana Maria Mariano; Novaes, Arthur Belém; Taba, Mário; Messora, Michel Reis; Palioto, Daniela Bazan; Grisi, Márcio Fernando Moraes; Tedesco, Antônio Cláudio; de Souza, Sérgio Luis Scombatti

    2016-09-01

    Scaling and root planing (SRP) may not always be effective in preventing periodontal disease (PD) progression. The aim of this study was to evaluate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to SRP on induced PD in rats, analyzing histomorphometrical, immunohistochemical, and immunoenzymatic parameters. Ligatures were placed around the first mandibular molars and second maxillary molars of 60 rats to induce PD. After 14 days, they were removed and the animals were divided into six groups, with nine animals each: G1 = no treatment, G2 = SRP, G3 = light-emitting diode (LED), G4 = SRP + aPDT, G5 = aPDT, and G6 = erythrosine. The animals were euthanized after 3, 7, and 15 days. There were also two control groups (n = 3): without PD (WPD) induction and with maximum PD (PD+). In the histomorphometrical analysis of linear bone loss, G4 showed a statistically significant difference from the other experimental groups after 3 and 15 days. The tartrate-resistant acid phosphatase (TRAP)-positive cell counting was significantly lower in G4 when compared to G2 and PD+ after 3 days. Immunoenzymatic assay shows the values of the ratio (RANKL/OPG × 100). The lowest value is from the WPD group, and the group that received the SRP + aPDT treatment tended to approach this value over time. After 3 days, statistically significant differences were observed between G4 and all other experimental groups, as well as versus PD+ (one-way ANOVA + Tukey's post hoc test were performed, p < 0.05). It was concluded that the adjunctive use of aPDT in combination with SRP showed the best therapeutic results in the treatment of periodontal disease in rats. PMID:27351664

  15. A histomorphometric study of osteocytic lacunae in interradicular bone with periodontal disease.

    PubMed

    Baró, M; Ferreyra, R; Nemer, K; Rocamundi, M; Crosa, M

    2003-01-01

    Previous studies report on the differences in volume of osteocytic lacunae that are associated to different local and systemic bone pathologies. Alterations have also been reported in rats with periodontal disease. The aim of the present study was to assess the histomorphometric pattern of osteocytic lacunae of the interradicular septum in human molars with periodontal disease (PD). We took samples of the interradicular septum of 31 molars with indication of extraction of male and female patients, 18-55 years old, who attend the Department of Surgery II of the Faculty of Dentistry, National University of Cordoba and private centers. Clinical records were prepared for each patient. The corresponding radiographs were taken for all the patients. We studied 11 samples of molars with slight PD and 12 control molars free from PD. Ten samples of healthy bone corticals of vestibular or lingual tables obtained from histopathology archives were also assessed. Following extraction with atraumatic pincers, the interradicular septum was removed. The samples were fixed in buffered formaline, decalcified in EDTA and embedded in paraffin. Ten micrometer sections were stained with H&E and Masson's trichromic technique. The sections were analyzed by light microscopy. A minimum of 50 lacunae were selected at random in each sample for histomorphometric evaluation. Semi-automatic evaluation of the area and diameters of the lacunae was performed employing an image analyzer and the PRO IMAGE PLUS software. The data showed that the volume of osteocytic lacunae of interradicular bone is larger than that of the cortical bone of the vestibular or lingual tables. The latter are more ribbon-shaped and their minor diameter is smaller. No differences were found between the osteocytic lacunae of the interradicular bone of healthy molars and that of molars with slight periodontal disease. Given that the experimental data evidenced volume changes in osteocytic lacunae of severe, inflammatory

  16. Laser ablation in titanium implants followed by biomimetic hydroxyapatite coating: Histomorphometric study in rabbits.

    PubMed

    Faeda, Rafael Silveira; Spin-Neto, Rubens; Marcantonio, Elcio; Guastaldi, Antonio Carlos; Marcantonio, Elcio

    2012-07-01

    Titanium surface texture and chemistry modification successfully improves the host response and consequently the bone-to-implant contact surrounding dental implants. The aim of the present study was to investigate, using histomorphometrical-analysis, the effects of titanium surface modification by laser-ablation (Nd:YAG) followed by thin chemical deposition of HA. Forty-eight rabbits received one implant by tibiae of AS-machined (MS), laser-modified (LMS), or biomimetic hydroxyapatite-coated (HA) surface. Bone-to-implant contact (BIC) and bone area (BBT) were evaluated after 4, 8, and 12 weeks, at cortical and cancellous regions. Average BIC in the cortical region was higher (P < 0.001) on the LMS and HA implants for all periods, with no differences between LMS and HA. For the cancellous area, the LMS and HA implants showed higher (P < 0.01) BIC than MS at the initial periods. The LMS and HA showed similar values in the cortical region, but a tendency of higher values for HA in the cancellous region was observed in all periods. For the BBT, the differences were found only between HA and MS after 4 weeks in the cortical region (P < 0.05), and after 12 weeks in the cancellous area (P < 0.05). Our results showed that HA biomimetic coating preceded by laser treatment induced the contact osteogenesis and allowed the formation of a more stable bone-implant interface, even in earlier periods. PMID:22389308

  17. Maxillary Sinus Augmentation Combining Bio-Oss with the Bone Marrow Aspirate Concentrate: A Histomorphometric Study in Humans

    PubMed Central

    Pasquali, Paulo José; Teixeira, Marcelo Lucchesi; de Oliveira, Thiago Altro; de Macedo, Luis Guilherme Scavone; Aloise, Antonio Carlos; Pelegrine, André Antonio

    2015-01-01

    Purpose. To investigate the regenerative results obtained with the association of bone marrow aspirate concentrate using the Bone Marrow Aspirate Concentrate (BMAC) method to a xenogeneic bone graft (Bio-Oss) in sinus floor elevation. Materials and Methods. Using a randomized controlled study design in eight consecutive patients (age of 55.4 ± 9.2 years), 16 sinus floor lift procedures were performed with Bio-Oss alone (control group, CG, n = 8) or combined with bone marrow aspirate concentrate obtained via the BMAC method (test group, TG, n = 8). Six months after the grafting procedures, bone biopsies were harvested during implant placement and were analyzed by histomorphometry. Results. Histomorphometric analysis revealed a significantly higher amount (p < 0.05) of vital mineralized tissue in TG when compared to the CG (55.15 ± 20.91% and 27.30 ± 5.55%, resp.). For nonvital mineralized tissue, TG presented a statistically higher level of Bio-Oss resorption (p < 0.05) when compared with the CG (6.32 ± 12.03% and 22.79 ± 9.60%, resp.). Both groups (TG and CG) showed no significantly different levels (p > 0.05) of nonmineralized tissue (38.53 ± 13.08% and 49.90 ± 7.64%, resp.). Conclusion. The use of bone marrow concentrate obtained by BMAC method increased bone formation in sinus lift procedures. PMID:26543482

  18. New cementum formation induced by cyclosporin A: a histological, ultrastructural and histomorphometric study in the rat.

    PubMed

    Ayanoglou, C M; Lesty, C

    1997-08-01

    Cyclosporin A (CsA), a widely used immunosuppressive agent, is known to induce gingival overgrowth; 30 mg/kg/d of CsA were administrated orally in young and adult male Sprague-Dawley rats. The same number of rats received oil-based vehicle solution. After 4, 9, 14 and 19 wk of CsA or vehicle administration 3 control and 3 experimental rats were anaesthetized and tissues fixed by an intracardiac perfusion of fixative solution. Upper and lower jaws were dissected, demineralized and processed for Epon inclusion. Histological examination revealed the presence of large amounts of new cementum (NC) covering extensive areas of the acellular extrinsic fibre cementum (AEFC) in all the root surfaces. NC was particularly abundant at the cervical third of the roots facing the gingival connective tissue, where it occurred as layers, spurs or in both configurations. NC was characterized by its irregular outline, globular body content and infrequent presence of incremental lines. Histomorphometric evaluation by semi-automatic image analysis indicated that the volume and the external surface of NC spurs were 2.86-6.49 and 1.29-1.97-fold increased comparative to those of the AEFC covering the same root areas. Electron microscopy revealed that NC was a functional tissue with insertion of collagen fibres perpendicularly to the long axis of the root. It can be concluded that under some experimental conditions formation of abundant amounts of NC can be achieved and that these results must be taken into account for a new approach in the treatment of periodontal disease. PMID:9379322

  19. Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report

    PubMed Central

    Annibali, Susanna; Iezzi, Giovanna; Sfasciotti, Gian Luca; Cristalli, Maria Paola; Vozza, Iole; Mangano, Carlo; La Monaca, Gerardo; Polimeni, Antonella

    2015-01-01

    Objective. The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA-β-TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA-β-TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months. Materials and Methods. Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA-β-TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses. Results. At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha-β-TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB. Conclusions. Within the limitations of the present investigation, these results support the successful use of HA-β-TCP 30/70 for sinus augmentation. PMID:26273589

  20. Evaluation of the Biocompatibility of Silicone Gel Implants – Histomorphometric Study

    PubMed Central

    França, Diurianne Caroline Campos; de Castro, Alvimar Lima; Soubhia, Ana Maria Pires; de Aguiar, Sandra Maria Herondina Coelho Ávila

    2013-01-01

    CONFLICT OF INTEREST: NONE DECLARED Breast implants are medical devices that are used to augment breast size or to reconstruct the breast following mastectomy or to correct a congenital abnormality. Breast implants consist of a silicone outer shell and a filler (most commonly silicone gel or saline). Approximately 5 to 10 million women worldwide have breast implants. Histomorphometric study to evaluate the biological tissue compatibility of silicone implants suitable for plastic surgery and the adverse effects and risks of this material. Thirty Wistar white rats received subcutaneous implants and the revestiment of silicone gel Silimed ®®, and randomized into six groups of five animals each, according to the type of implanted material and the time of sacrifice. Eight areas of 60.11mm2 corresponding to the obtained surgical pieces were analyzed, counting mesenchymal cells, eosinophils, and foreign body giant cells, observing an acceptable biocompatibility in all implants, for subsequent statistical analysis by Tukey test. Silicone gel showed inflammation slightly greater than for other groups, with tissue reactions varying from light to moderate, whose result was the formation of a fibrous capsule around the material, recognized by the organism as a foreign body. Despite frequent local complications and adverse outcomes, this research showed that the silicone and top layer presented an acceptable chronic inflammatory reaction, which did not significantly differ from the control group. In general, it is possible to affirm that silicone gel had acceptable levels of biocompatibility, confirmed the rare presence of foreign body giant cells, and when of the rupture, formed a fibrous capsule around the material, separating the material of the organism. PMID:24039333

  1. Quantification of Osteon Morphology Using Geometric Histomorphometrics.

    PubMed

    Dillon, Scott; Cunningham, Craig; Felts, Paul

    2016-03-01

    Many histological methods in forensic anthropology utilize combinations of traditional histomorphometric parameters which may not accurately describe the morphology of microstructural features. Here, we report the novel application of a geometric morphometric method suitable when considering structures without anatomically homologous landmarks for the quantification of complete secondary osteon size and morphology. The method is tested for its suitability in the measurement of intact secondary osteons using osteons digitized from transverse femoral diaphyseal sections prepared from two human individuals. The results of methodological testing demonstrate the efficacy of the technique when applied to intact secondary osteons. In providing accurate characterization of micromorphology within the robust mathematical framework of geometric morphometrics, this method may surpass traditional histomorphometric variables currently employed in forensic research and practice. A preliminary study of the intersectional histomorphometric variation within the femoral diaphysis is made using this geometric histomorphometric method to demonstrate its potential. PMID:26478136

  2. A histomorphometric study of the effect of doxycycline and erythromycin on bone formation in dental alveolar socket of rat

    PubMed Central

    Shahabooei, Mohammad; Razavi, Sayed Mohammad; Minaiyan, Mohsen; Birang, Reza; Behfarnia, Parichehr; Yaghini, Jaber; Naghsh, Narges; Ghalayani, Parichehr; Hajisadeghi, Samira

    2015-01-01

    Background: The aim of the present study was to evaluate whether subantimicrobial doses of doxycycline (DOX) and erythromycin (EM) used for the treatment of peri-implant osteolysis due to their anti-osteoclastogenesis can interfere with the osseous wound healing process in rat alveolar socket. Materials and Methods: Forty-five male Wistar rats had their first maxillary right molar extracted and were divided into three groups. DOX and EM at the doses of 5 mg/kg/day orally (p.o.) and 2 mg/kg/day intraperitoneally (i.p.) were administered respectively to two separate groups for 7 days after operation. In the control group the animals received normal saline (5 ml/kg). Five rats were sacrificed at 7, 14 and 21 days post-extraction in each study group. A histomorphometric analysis was used to evaluate new bone formation inside the alveolar socket. Significant level was set at 0.05. Results: The findings showed that the percentage of new bone formation (NBF) enhanced significantly on days 7 and 14. There was no significant difference in the NBF between DOX and EM groups. Conclusion: Short-term treatment with both DOX and EM enhanced new bone formation without any advances in favor of each drug. PMID:25878996

  3. Histomorphometric study on the osteocyte lacuno-canalicular network in animals of different species. I. Woven-fibered and parallel-fibered bones.

    PubMed

    Remaggi, F; Canè, V; Palumbo, C; Ferretti, M

    1998-01-01

    A comparative histomorphometric study was carried out on the extension of lacunocanalicular network in two types of bone tissue (woven and parallel-fibered) in shaft bones of various animals (Frog, Chicken, Rabbit, Bovine, Horse, Dog, Man), with the aim to understand whether the distribution of osteocyte network is related to the organization of the collagen fibers or to the animal species. By means of a light microscope (LM) connected with an image-Analyser the following parameters were measured: 1) the cross-sectional area and the volume of osteocyte lacunae; 2) the osteocyte density; 3) the number of canaliculi departing both from the whole outline of the sectional area of osteocyte lacunae and, in the parallel-fibered osteons only (both with LM and SEM), from their two opposite walls, i.e., from the wall facing the Haversian canal (vascular wall) and from that facing the cement line (peripheral wall). In all the animals studied the size and density of osteocyte lacunae as well as the extension of the canalicular network proved to be markedly higher in woven than in parallel-fibered bone, whereas no relation with the species was found. These findings suggest that the function of osteocyte is mainly involved in the regulation of skeletal homeostasis, as discussed in the present paper. PMID:9882957

  4. Effects of prenatal diclofenac sodium exposure on newborn testis: a histomorphometric study.

    PubMed

    Arslan, H; Aktaş, A; Elibol, E; Esener, Obb; Türkmen, A P; Yurt, K K; Onger, M E; Altunkaynak, B Z; Kaplan, S

    2016-05-01

    Diclofenac sodium (DS) is used primarily to treat fever and to alleviate pain and inflammation. We investigated the effects of DS exposure during gestation on the testes of rat pups to investigate the safety of its use during the prenatal period. Pregnant rats were separated into control, saline, low dose, medium dose and high dose groups. DS was given between weeks 15 and 21 of gestation. Total numbers of spermatogonia and Sertoli cells were counted in the testes of 7-day-old male rats using the physical disector method. By the end of the study, the total number of Sertoli cells was decreased significantly in a dose dependent manner in the medium and high dose groups compared to controls. No significant differences were found in the total number of spermatogonia in the control, saline and low dose DS groups. Medium and high dose DS administration reduced the total number of spermatogonia compared to other groups. We suggest that prenatal administration of DS can cause deleterious effects on the testis development, especially in high doses. PMID:26984645

  5. Dietary arginine silicate inositol complex increased bone healing: histologic and histomorphometric study

    PubMed Central

    Yaman, Ferhan; Acikan, Izzet; Dundar, Serkan; Simsek, Sercan; Gul, Mehmet; Ozercan, Ibrahim Hanifi; Komorowski, James; Sahin, Kazim

    2016-01-01

    Background Arginine silicate inositol complex (ASI; arginine 49.5%, silicon 8.2%, and inositol 25%) is a novel material that is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Objective The aim of this study was to evaluate the potential effects of ASI complex on bone healing of critical-sized defects in rats. Methods The rats were randomly assigned to two groups of 21 rats each. The control group was fed a standard diet for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The ASI group was fed a diet containing 1.81 g/kg of ASI for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The calvarial bones of all the rats were then harvested for evaluation. Results Osteoblasts and osteoclasts were detected at higher levels in the ASI group compared with the control group at days 7, 14, and 28 of the calvarial defect (P<0.05). New bone formation was detected at higher levels in the ASI group compared with the controls at day 28 (P<0.05). However, new bone formation was not detected at days 7 and 14 in both the groups (P>0.05). Conclusion ASI supplementation significantly improved bone tissue healing in rats with critical-sized defects. This study demonstrated that ASI can enhance bone repair and has potential as a therapeutic regimen in humans. PMID:27390517

  6. Histomorphometric Study of Alveolar Bone Healing in Rats Fed a Boron-Deficient Diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. Weanling Wistar rats were divided into two groups: control (+B; 3 mg B/kg diet), and ...

  7. Sinus grafting with autogenous platelet-rich plasma and bovine hydroxyapatite. A histomorphometric study in minipigs.

    PubMed

    Fürst, Gabor; Gruber, Reinhard; Tangl, Stefan; Zechner, Werner; Haas, Robert; Mailath, Georg; Sanroman, Fidel; Watzek, Georg

    2003-08-01

    In this study, bovine hydroxyapatite (HA) alone or in combination with activated platelet-rich plasma (PRP) was examined for its usefulness for single-stage sinus grafting in minipigs. In 12 adult minipigs, Schneider's membrane of 24 sinuses was elevated bilaterally through an extra-oral approach. The material was divided into two groups of 12 sinuses. In one of these groups, the space between Schneider's membrane and the sinus wall was grafted with activated autogenous PRP and HA (PRP side). In the other, HA alone was used for grafting (control side). At the same time two dental implants with a machined surface were inserted into the grafting material through the facial sinus wall. Four animals of each group were sacrificed at 3, 6 and 12 weeks, and undecalcified thin-cut and ground sections (Donath 1988) stained with toluidine blue were prepared. In the facial sinus wall, fewer bone-to-implant contacts were present on the PRP side at 3 and 6 weeks than on the control side. At 12 weeks, the PRP side had caught up with the control side. In grafted bone, contacts on the PRP side were more extensive than on the control side at 3 weeks, had dropped below control side levels at 6 weeks and surpassed these at 12 weeks. This study showed that PRP has a differential effect on osseointegration in grafted bone and local host bone. Combined with HA it was not demonstrably superior to HA alone. PMID:12869013

  8. The use of platelet-rich fibrin (PRF) and PRF-mixed particulated autogenous bone graft in the treatment of bone defects: An experimental and histomorphometrical study

    PubMed Central

    Kökdere, Nesligül Niyaz; Baykul, Timuçin; Findik, Yavuz

    2015-01-01

    Background: Various materials and techniques have been developed to facilitate bone healing process and reduce its healing period. In recent studies, it is pointed out that, platelet-rich fibrin (PRF) which is derived autogenously from the own blood of the individuals, increase regeneration and accelerate the healing of the wound, due to the consisting various growing factors. The aim of the experimental study is to evaluate the efficiency of PRF and PRF/autogenous graft combination on bone healing in different time intervals. Materials and Methods: A total of 24 skeletally mature New Zealand rabbits were used. Animals were divided randomly into two groups. Two bone defects with a diameter 3, 3 mm were created on the right and left tibia in all group animals. Only particulate autogeneous bone graft, only PRF, combination of PRF and autogeneous bone graft and empty bone cavity, were performed to all animals. The animals in the first experimental group were sacrificed after 30 days. The animals in the second experimental group were sacrificed after 60 days from the operation. Histomorphometrical and statistical analysis was performed. The data were analyzed using Tukey test (P < 0.05 for osteoblast number, P < 0.01 for osteoclast and new bone area values). Results: Histomorphometrical analyzes showed that either PRF used alone or used in conjuction with autogenous bone graft, PRF accelerated the healing of the bone defects. There were statistically significant differences in osteoblast, osteoblast and new bone area values in PRF alone and autogenous graft with PRF than the other groups. Conclusion: Our preliminary result demonstrated that PRF increase new bone formation and has a positive effect on early bone healing. PMID:26604954

  9. A comparison of histomorphometric data collection methods.

    PubMed

    Stewart, Marissa C; McCormick, Lara E; Goliath, Jesse R; Sciulli, Paul W; Stout, Sam D

    2013-01-01

    Although many variables that skeletal biologists examine have been standardized, the actual techniques used to collect these data from bone thin sections vary. This project compares different methods of obtaining data (relative cortical area values) for histomorphometric research. One visual and three digital methods of histomorphometric data collection are compared: (i) Merz microscopic eyepiece counting reticule, (ii) flatbed scanner, (iii) overlaying multiple images of a thin section, and (iv) digital SLR camera with macro settings. The discussion includes a comparison of usability factors such as cost, time, user-experience, and ease-of-use, which vary for each method. Values from the different methods are compared using ANOVA tests to evaluate inter-method, inter-observer, and intra-observer variability. Intra-observer error was greater for the microscopic method, although the error values are concomitant with experience. We found no statistically significant differences between the four methods examined, but certain caveats must be addressed when these methods are used. PMID:22621277

  10. Intermittent administration of parathyroid hormone improves the repairing process of rat calvaria defects: A histomorphometric and radiodensitometric study

    PubMed Central

    Silva, Eduardo-de-Paula; Marques, Marcelo-Rocha; Dias da Silva, Marco-Antônio; Manzi, Flávio-Ricardo; Barros, Silvana-Pereira

    2015-01-01

    Background The aim of this study was to evaluate the effects of intermittent treatment of parathyroid hormone (PTH (1-34)) on the bone regeneration of critically-sized rat calvarial bone defects. Material and Methods Thirty-two male rats were trephined (4mm fullthickness diameter), in the central part of the parietal bones and divided into 2 groups of 16. The PTH group received subcutaneous injections of PTH (1-34) at 40µg/kg, 3 times a week and the control (CTL) group received the vehicle in the same regimen. The rats were sacrificed at 4 weeks post-treatment regimen, the parietal bones were extracted and samples were evaluated through histomorphometry and radiodensitometry. Results The histological observations showed that the PTH group presented more “island-like” new bone between the defect margins with fibrous tissues than did the CTL group. The PTH group significantly exhibited greater histologic bone formation than did the CTL group (1.5mm ±0.7; 1.9 mm ± 0.6, p<0.05/ for residual bone defect). The radiodensitometry analysis revealed significant differences among the PTH and CTL groups (2.1 Al eq. ±0.04; 1.8Al eq. ±0.06, p<0.05), demonstrating an increase in bone mineral density. The PTH treatment contributed to the bone formation with a higher amount of mineral and/or fibrous tissue when compared with the CTL group. Conclusions The results suggest that it was possible to increase the process of bone regeneration by accelerating the healing process in rat calvarial defects through intermittent administration of the PTH treatment. Key words: Bone, skull, rats, bone regeneration, bone density. PMID:26034928

  11. A histomorphometric study of alveolar bone modeling and remodeling in mice fed a boron-deficient diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Objective: Emerging evidence indicates that boron (B) plays a role in bone formation and maintenance. Thus, a study was performed to determine whether dietary B-deficiency affects periodontal alveolar bone modeling and remodeling. Material and Methods: Weanling Swiss mice (n=30) were ...

  12. Utilization of ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives for autogenous bone graft fixation: histomorphometric study in rats.

    PubMed

    Esteves, Jônatas Caldeira; Monteiro, Jônatas Mattos; Aranega, Alessandra Marcondes; Betoni Junior, Walter; Sonoda, Celso Koogi

    2014-08-01

    The present study analyzes the repair process of autogenous bone graft in a block fixed with ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives in rat calvaria. Forty-eight rats, divided into 3 groups, received round osteotomies at the right parietal bone for the attainment of autogenous bone graft fragment, which was fixed at the opposite side to the donor site with ethyl cyanoacrylate (ethyl group) and 2-octyl cyanoacrylate (octyl group) adhesives. In the control group, bone fragment was only juxtaposed at the parietal bone surface without any fixation material. The animals were euthanized after 10 and 60 postoperative days. The calvariae were processed in a laboratory for the attainment of slides stained through the hematoxylin and eosin technique for histological and histometric analysis. The qualitative analysis showed a discrete inflammatory infiltrate in the control group and moderate inflammatory infiltrate in the ethyl and octyl groups at the 10-day period, which remained at the 60-day period, mainly in the octyl group. The bone fragment remained bonded to the recipient site through the adhesive, but graft incorporation was not observed in any of the specimens. Resorption was higher in the octyl group followed by the ethyl and control groups, both at the 10- and 60-day periods, but with no statistical significance (P < .05). Although promoting graft fixation and its maintenance at the recipient site, both studied adhesives did not allow the graft incorporation, producing a localized and discrete inflammatory reaction, which persisted at 60 days, being more intense in the octyl cyanoacrylate group. PMID:25106004

  13. The effects of 1,25-dihydroxycholecalciferol, parathyroid hormone, and thyroxine on trabecular bone remodeling in adult dogs. A histomorphometric study.

    PubMed Central

    High, W. B.; Capen, C. C.; Black, H. E.

    1981-01-01

    The effects of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3), parathyroid hormone (PTH), and L-thyroxine (T4) on trabecular bone remodeling were evaluated by histomorphometric methods in adult female beagle dogs. Intravenous 1,25-(OH)2D3 (1.25 micrograms/day in equally divided doses) was administered intermittently for 6 days and withdrawn 14 days for three complete cycles. PTH was administered intravenously (2.5 U/kg/day) in divided doses 6 hours apart for 60 days. Thyroxine was given orally (1.0 mg/kg/day) in divided doses for a similar interval. Static and dynamic changes were evaluated using tetracycline and DCAF (2,4 BIS) N, N', Di (carboxymethyl) (amino methyl fluorescein) in vivo double labeling of bone from the iliac crest taken before treatment and after 60 days. The intermittent administration of 1,25-(OH)2D3 stimulated the bone resorption rate and depressed the formation rate. 1,25-(OH)2D3 increased trabecular resorption surfaces; osteoid surface, volume, and thickness; mineralization lag time; and osteoblast number but decreased the bone volume. Multiple small daily doses of PTH resulted in an overall negative balance in trabecular bone. This was associated with an increased trabecular surface-to-volume ratio, bone resorption and formation rates, active forming surfaces, osteoid volume and surface, life span of bone forming and resorbing sites, and the number of osteoclast nuclei. Thyroxine appeared to increase bone mass by enhancing the switch-over from the resorptive to the formative phase of remodeling. Coupling between osteoid apposition and mineralization was increased by recruiting more forming sites and prolonging their life span. Thyroxine increased bone resorption and formation rates, trabecular bone volume and balance, number of osteoclast nuclei, and life span of bone forming sites. The osteoid seam thickness and mineralization lag time were decreased. The present study demonstrated that 1,25-(OH)2D3, PTH, and thyroxine at the dose and

  14. Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

    PubMed

    Paknejad, Mojgan; Eslaminejad, Mohamadreza Baghaban; Ghaedi, Baharak; Rokn, Amir-Reza; Khorsand, Afshin; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Dehghan, Mohammad Mehdi; Moslemi, Neda; Nowzari, Hessam

    2015-06-01

    The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations. PMID:24383495

  15. Negative effects of nicotine on bone-resorbing cytokines and bone histomorphometric parameters in male rats.

    PubMed

    Hapidin, Hermizi; Othman, Faizah; Soelaiman, Ima-Nirwana; Shuid, Ahmad N; Luke, Douglas A; Mohamed, Norazlina

    2007-01-01

    The effects of nicotine administration on bone-resorbing cytokines, cotinine, and bone histomorphometric parameters were studied in 21 Sprague-Dawley male rats. Rats aged 3 months and weighing 250-300 g were divided into three groups. Group 1 was the baseline control (BC), which was killed without treatment. The other two groups were the control group (C) and the nicotine-treated group (N). The N group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection for 6 days/week for 4 months. The rats were injected intraperitoneally with calcein 20 mg/kg body weight at day 9 and day 2 before they were killed. ELISA test kits were used to measure the serum interleukin-1 (IL-1), interleukin-6 (IL-6), and cotinine (a metabolite of nicotine) levels at the beginning of the study and upon completion of the study. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis revealed that nicotine treatment for 4 months significantly increased the serum IL-1, IL-6, and cotinine levels as compared to pretreatment levels. In addition, the serum cotinine level was significantly higher in the N group than in the C group after 4 months treatment. Histomorphometric analysis showed that nicotine significantly decreased the trabecular bone volume (BV/TV), trabecular thickness (Tb.Th), double-labeled surface (dLS/BS), mineralizing surface (MS/BS), mineral appositional rate (MAR), and bone formation rate (BFR/BS), while causing an increase in the single-labeled surface (sLS/BS), osteoclast surface (Oc.S/BS), and eroded surface (ES/BS) as compared to the BC and C groups. In conclusion, treatment with nicotine 7 mg/kg for 4 months was detrimental to bone by causing an increase in the bone resorbing cytokines and cotinine levels. Nicotine also exerted negative effects on the dynamic trabecular histomorphometric

  16. Histomorphometric comparison after fixation with formaldehyde or glyoxal

    PubMed Central

    Wang, YN; Lee, K; Pai, S; Ledoux, WR

    2014-01-01

    Formaldehyde has long been the fixative of choice for histological examination of tissue. The use of alternatives to formaldehyde has grown, however, owing to the serious hazards associated with its use. Companies have striven to maintain the morphological characteristics of formaldehyde-fixed tissue when developing alternatives. Glyoxal-based fixatives now are among the most popular formaldehyde alternatives. Although there are many studies that compare staining quality and immunoreactivity, there have been no studies that quantify possible structural differences. Histomorphometric analysis commonly is used to evaluate diseased tissue. We compared fixation with formaldehyde and glyoxal with regard to the histomorphological properties of plantar foot tissue using a combination of stereological methods and quantitative morphology. We measured skin thickness, interdigitation index, elastic septa thickness, and adipocyte area and diameter. No significant differences were observed between formaldehyde and glyoxal fixation for any feature measured. The glyoxal-based fixative used therefore is a suitable fixative for structural evaluation of plantar soft tissue. Measurements obtained from the glyoxal-fixed tissue can be combined with data obtained from formalin-fixed for analysis. PMID:20854226

  17. Bioactive glass in cavitary bone defects: a comparative experimental study in rabbits

    PubMed Central

    Camargo, André Ferrari de França; Baptista, André Mathias; Natalino, Renato; de Camargo, Olavo Pires

    2015-01-01

    OBJECTIVES: To compare bioactive glass and autograft regarding their histomorphometric characteristics. METHODS: The authors conducted a prospective case-control experimental study on animals in order to compare the histomorphometric characteristics of bioactive glass versus autograft. Eight rabbits underwent surgery in which a cavitary defect was created in both proximal femurs. One side was filled with bioactive glass granules and the other, with autograft grafted from the contralateral side. The sides were randomized. Fourteen days after surgery, the animals were euthanized. RESULTS: Histologic analysis revealed that bone neoformation was equivalent among the two groups and the osteoblasts cell-count was higher in the femurs treated with bioactive glass. The osteocytes cell-count, however, was lower. The similarity in bone formation between both groups was consistent to literature findings. CONCLUSION: Bioactive glass is similar to autograft regarding bone neoformation in this animal model of cavitary bone defects. Level of Evidence III, Case-Control Study. PMID:26327802

  18. Histological and histomorphometric investigation of the condylar cartilage of juvenile pigs after anterior mandibular displacement.

    PubMed

    Proff, Peter; Gedrange, Tomas; Franke, Reiner; Schubert, Harald; Fanghänel, Jochen; Miehe, Bärbel; Harzer, Winfried

    2007-01-01

    The condylar cartilage of the mandible is considered a secondary growth center and represents a joint cartilage different from other cartilage structures regarding its histological structure, its histochemical and immunohistochemical properties and its growth pattern. This study aimed to histologically and histomorphometrically investigate the condylar cartilage after anterior mandibular displacement similar to functional orthopedic treatment. A total of 12 pigs (sus scrofa domesticus) aged 10 weeks were divided into an experimental group and a control group comprising 6 animals each. The experimental animals were provided bilaterally with synthetic occlusal build-ups in the posterior area which induced anterior displacement of the mandible in terminal occlusion. After 4 weeks, the temporomandibular structures were removed en bloc and the condylar cartilage was analyzed histologically and histomorphometrically. As a result, the experimental animals displayed a significantly increased total cartilage thickness of the posterocranial mandibular condyle which was primarily caused by an increase in thickness of the hypertrophic and chondogenic layers. Similarly, the proliferative layer showed a significant increase, whereas significant differences in thickness were absent in the articular layer. Increased cell proliferation was not observed in the experimental animals as compared to the controls. The changes found in the condylar cartilage area suggest that the zonal structure of the condylar cartilage may be modified by an altered spatial relationship between the mandibular condyle and the glenoid fossa. PMID:17534034

  19. Histological and histomorphometric analysis of animal experimental dehiscence defect treated with three bio absorbable GTR collagen membrane

    PubMed Central

    Behfarnia, Parichehr; Khorasani, Mitra Mohammad; Birang, Reza; Abbas, Fateme Mashhadi

    2012-01-01

    Background: Guided tissue regeneration (GTR) allows mesenchymal cells to repopulate the defects. However, there is limited information regarding the efficacy of different membranes. The present study was designed to histologically and histomorphometrically compare three collagen membranes in regenerative treatment of dehiscence defects in dogs. Materials and Methods: This 8 weeks experimental animal study comprised 4 healthy dogs. 5 × 5 mm periodontal dehiscences were created in each side of the mandible (4 dehiscences in each side of dogs’ mandible). In each side, one dehiscence defect was left uncovered as a control site and three other sites were randomly covered with different collagen membranes (Biogide (BG), Biomend (BM), and Cytoplast (CYT)). Histomorphometric and histologic analysis were conducted at 4 and 8 weeks. Data were analyzed using ANOVA, Mann-Withney, Kruskal-Wallis and Fisher 's exact tests (α = 0.05). Results: According to histomorphometric analysis there was a significant difference between treatment and control groups regarding the bone formation and the distance between the reference point and apical end of junctional epithelium (DJE) (P < 0.05). At 4 weeks, the maximum amount of bone thickness and height was observed in BG and CYT respectively, and this maximum rate was seen with the use of BG at 8 weeks. It was shown that DJE reached its highest rate in BM and CYT at 4 and 8 weeks, respectively. Organized PDL was formed in treatment groups. Conclusion: The membrane-treated groups had a statistically significant increase in bone formation and connective tissue attachment compared to control groups. However, there are some differences among experimental groups, which should be considered in GTR treatments. PMID:23559922

  20. Effect of xenograft (ABBM) particle size on vital bone formation following maxillary sinus augmentation: a multicenter, randomized, controlled, clinical histomorphometric trial.

    PubMed

    Testori, Tiziano; Wallace, Stephen S; Trisi, Paolo; Capelli, Matteo; Zuffetti, Francesco; Del Fabbro, Massimo

    2013-01-01

    The purpose of this study was a histomorphometric comparison of vital bone formation following maxillary sinus augmentation with two different particle sizes of anorganic bovine bone matrix (ABBM). Bilateral sinus floor augmentations were performed in 13 patients. Trephine bone cores were taken from the lateral window areas of 11 patients 6 to 8 months after augmentation for histologic and histomorphometric analysis. Bone samples from both the large and small particle size groups showed evidence of vital bone formation similar to that seen in previous studies, confirming the osteoconductivity of ABBM. Significant bone bridging was seen creating new trabeculae composed of the newly formed bone and residual ABBM particles. Histologic evaluation revealed the newly formed bone to be mostly woven bone with some remodeling to lamellar bone. Osteocytes were seen within the newly formed bone as well as osteoblast seams with recently formed osteoid. Isolated osteoclasts were observed on the ABBM surfaces. Vital bone formation (primary outcome measure) was more extensive in the large particle grafts compared with the small particle grafts (26.77% ± 9.63% vs 18.77% ± 4.74%, respectively). The histologic results reaffirm the osteoconductive ability of ABBM when used as the sole grafting material in maxillary sinus augmentation. The histomorphometric results at 6 to 8 months revealed a statistically significant increase (P = .02) in vital bone formation when the larger particle size was used. Additional studies should be performed to confirm these results. PMID:23820706

  1. Histomorphometric and histologic evaluation of titanium-zirconium (aTiZr) implants with anodized surfaces.

    PubMed

    Sharma, Ajay; McQuillan, A James; Shibata, Yo; Sharma, Lavanya A; Waddell, John Neil; Duncan, Warwick John

    2016-05-01

    The choice of implant surface has a significant influence on osseointegration. Modification of TiZr surface by anodization is reported to have the potential to modulate the osteoblast cell behaviour favouring more rapid bone formation. The aim of this study is to investigate the effect of anodizing the surface of TiZr discs with respect to osseointegration after four weeks implantation in sheep femurs. Titanium (Ti) and TiZr discs were anodized in an electrolyte containing DL-α-glycerophosphate and calcium acetate at 300 V. The surface characteristics were analyzed by scanning electron microscopy, electron dispersive spectroscopy, atomic force microscopy and goniometry. Forty implant discs with thickness of 1.5 and 10 mm diameter (10 of each-titanium, titanium-zirconium, anodized titanium and anodized titanium-zirconium) were placed in the femoral condyles of 10 sheep. Histomorphometric and histologic analysis were performed 4 weeks after implantation. The anodized implants displayed hydrophilic, porous, nano-to-micrometer scale roughened surfaces. Energy dispersive spectroscopy analysis revealed calcium and phosphorous incorporation into the surface of both titanium and titanium-zirconium after anodization. Histologically there was new bone apposition on all implanted discs, slightly more pronounced on anodised discs. The percentage bone-to-implant contact measurements of anodized implants were higher than machined/unmodified implants but there was no significant difference between the two groups with anodized surfaces (P > 0.05, n = 10). The present histomorphometric and histological findings confirm that surface modification of titanium-zirconium by anodization is similar to anodised titanium enhances early osseointegration compared to machined implant surfaces. PMID:26970768

  2. Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone

    PubMed Central

    Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito; Kjellin, Per; Currie, Fredrik; Wennerberg, Ann

    2016-01-01

    Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test), and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone–implant contact was higher for test compared to control (P<0.05). The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01). With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential. PMID:27103801

  3. Comparative Packaging Study

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele; Antonini, David

    2008-01-01

    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  4. [Relations between trabecular bone mass and the configuration in the space of the trabeculae of bone. Histomorphometric study of a population of 145 osteoporotic women].

    PubMed

    Chappard, D; Alexandre, C; Riffat, G

    1988-01-01

    145 women with involution osteoporosis and at least one vertebral compression noted on X-Rays, underwent a biopsy of the iliac wing and measurement of the mean cortical thickness, trabecular bony volume and parameters concerning the spatial configuration of bony trabecules (MTPT = Mean Trabecular Plate Thickness, MTPD = Mean Trabercular Plate Density, MTPS = Mean Trabecular Plate Separation), reflecting respectively the thickness, the density and the separation of the trabecules. The results were compared with those of a series of 22 control women of the same age. The post-menopausal osteoporotic patients present a decreased VTO, MTPD and MTPS with normal MTPT. Patients with senile osteoporosis show no difference as compared to the control patients of the same age. Half of the patients had a VTO higher than the spontaneous vertebral fracture threshold. Involution osteoporosis where the VTO exceeds the threshold present a significant decrease of the number of bony trabecules without decreased thickness. There is a negative correlation between age and the number of trabecules; a linear correlation between VTO and thickness, between VTO and trabecular density confirming the close relationship between mass and spatial configuration of the bone. There is a geometric configuration between density and separation of the trabecules, indicating a great sensitivity of the microstructural framework of disorganized trabecular bone. These data show that a decreased bony mass is not the only physiopathological mechanism observed during involution osteoporosis. Alterations of the spatial configuration of the trabecules or the mechanical resistance of the bony matrix are additional factors, the role of which might have been underestimated. PMID:3353672

  5. Dynamics of bone healing after osteotomy with piezosurgery or conventional drilling – histomorphometrical, immunohistochemical, and molecular analysis

    PubMed Central

    2013-01-01

    Background Piezosurgery is an osteotomy system used in medical and dental surgery. Many studies have proven clinical advantages of piezosurgery in terms of quality of cut, maneuverability, ease of use, and safety. However, few investigations have tested its superiority over the traditional osteotomy systems in terms of dynamics of bone healing. Therefore, the aim of this study was to evaluate the dynamics of bone healing after osteotomies with piezosurgery and to compare them with those associated to traditional bone drilling. Methods One hundred and ten rats were divided into two groups with 55 animals each. The animals were anesthetized and the tibiae were surgically exposed to create defects 2 mm in diameter by using piezosurgery (Piezo group) and conventional drilling (Drill group). Animals were sacrificed at 3, 7, 14, 30 and 60 days post-surgery. Bone samples were collected and processed for histological, histomorphometrical, immunohistochemical, and molecular analysis. The histological analysis was performed at all time points (n = 8) whereas the histomorphometrical analysis was performed at 7, 14, 30 and 60 days post-surgery (n = 8). The immunolabeling was performed to detect Vascular Endothelial Growth Factor (VEGF), Caspase-3 (CAS-3), Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), and Osteocalcin (OC) at 3, 7, and 14 days (n = 3). For the molecular analysis, animals were sacrificed at 3, 7 and 14 days, total RNA was collected, and quantification of the expression of 21 genes related to BMP signaling, Wnt signaling, inflammation, osteogenenic and apoptotic pathways was performed by qRT-PCR (n = 5). Results Histologically and histomorphometrically, bone healing was similar in both groups with the exception of a slightly higher amount of newly formed bone observed at 30 days after piezosurgery (p < 0.05). Immunohistochemical and qRT-PCR analyses didn’t detect significant differences in

  6. Low-level laser therapy affects osseointegration in titanium implants: resonance frequency, removal torque, and histomorphometric analysis in rabbits

    PubMed Central

    2016-01-01

    Objectives The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. Materials and Methods Thirteen New Zealand white male rabbits weighing 3.0±0.5 kg were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. Results The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. Conclusion Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects. PMID:26904488

  7. Operations dashboard: comparative study

    NASA Astrophysics Data System (ADS)

    Ramly, Noor Nashriq; Ismail, Ahmad Zuhairi; Aziz, Mohd Haris; Ahmad, Nurul Haszeli

    2011-10-01

    In this present days and age, there are increasing needs for companies to monitor application and infrastructure health. Apart from having proactive measures to secure their application and infrastructure, many see monitoring dashboards as crucial investment in disaster preparedness. As companies struggle to find the best solution to cater for their needs and interest for monitoring their application and infrastructure's health, this paper summarizes the studies made on several known off-the-shelf operations dashboard and in-house developed dashboard. A few criteria of good dashboard are collected from previous studies carried out by several researchers and rank them according to importance and business needs. The finalized criteria that will be discussed in later sections are data visualization, performance indicator, dashboard personalization, audit capability and alert/ notification. Comparative studies between several popular dashboards were then carried out to determine whether they met these criteria that we derived from the first exercise. The findings hopefully can be used to educate and provide an overview of selecting the best IT application and infrastructure operations dashboard that suit business needs, thus become the main contribution of this paper.

  8. Histomorphometric Evidence of Growth Plate Recovery Potential after Fractionated Radiotherapy

    PubMed Central

    Damron, Timothy A.; Horton, Jason A.; Pritchard, Meredith R.; Stringer, Matthew T.; Margulies, Bryan S.; Strauss, Judith A.; Spadaro, Joseph A.; Farnum, Cornelia E.

    2008-01-01

    This study evaluated the hypothesis that early growth plate radiorecovery is evident by growth rate, histomorphometric and immunohistochemical end points after exposure to clinically relevant fractionated radiation in vivo. Twenty-four weanling 5-week-old male Sprague-Dawley rats were randomized into eight groups. In each animal, the right distal femur and proximal tibia were exposed to five daily fractions of 3.5 Gy (17.5 Gy) with the left leg serving as a control. Rats were killed humanely at 7, 8, 9, 10, 11, 14, 15 and 16 days after the first day of radiation exposure. Quantitative end points calculated included individual zonal and overall growth plate heights, area matrix fraction, OTC-labeled growth rate, chondrocyte clone volume and numeric density, and BrdU immunohistochemical labeling for proliferative index. Transient postirradiation reductions occurred early and improved during observation for growth rate, proliferative indices, transitional/hypertrophic zone matrix area fraction, proliferative height, and clonal volume. Reserve and hypertrophic zone height remained increased during the period of observation. The current model, using a more clinically relevant fractionation scheme than used previously, shows early evidence of growth plate recovery and provides a model that can be used to correlate temporal changes in RNA and protein expression during the early period of growth plate recovery. PMID:18763859

  9. Histomorphometric evaluation of treatment of rat azoosper-mic seminiferous tubules by allotransplantation of bone marrow-derived mesenchymal stem cells

    PubMed Central

    Rahmanifar, Farhad; Tamadon, Amin; Mehrabani, Davood; Zare, Shahrokh; Abasi, Sorush; Keshavarz, Saeideh; Dianatpour, Mehdi; Khodabandeh, Zahra; Jahromi, Iman Raze ghian; Koohi-Hoseinabadi, Omid

    2016-01-01

    Objective(s): Bone marrow-derived mesenchymal stem cells (BM-MSCs) potentials make them appropriate for cell therapy including ability of differentiation and release of anti-inflammatory cytokines and growth factors secreta. For treatment of azoospermia to induce proliferation and differentiation of germ cells, MSCs transplantation has been introduced. The aim of the present experimental case-control study was to histomorphometric evaluation of the germinal cells in seminiferous tubules of azoospermic rats before and after BM-MSCs allotransplantation. Materials and Methods: In the present study, BM-MSCs were isolated from six male rats and confirmed. Their testes also served as intact negative controls. The recipient rats (n=6) were received two doses of 10 mg/kg of busulfan with 21 days interval to induce azoospermia. After cessation of spermatogenesis, the rats were allotransplanted with the BM-MSCs into efferent duct of right testes. Thirty-five days later, the right cell-treated testes were compared to left azoospermic ones. Results: Histomorphometric analyses showed that the seminiferous tubules treated with BM-MSCs had normal morphology in comparison with azoospermic testes, which were without germinal layer. In most BM-MSCs-treated seminiferous tubules, spermatogenesis was observed. Conclusion: The allotransplanted BM-MSCs could induce spermatogenesis in seminiferous tubules of azoospermic rats. PMID:27482347

  10. Histopathology and Histomorphometric Investigation of Bisphenol A and Nonylphenol on the Male Rat Reproductive System

    PubMed Central

    Kazemi, Sohrab; Feizi, Farideh; Aghapour, Fahimaeh; Joorsaraee, Gholam Ali; Moghadamnia, Ali Akbar

    2016-01-01

    Background: Bisphenol A (BPA) and nonylphenol (NP) have harmful effects on the endocrine system of humans and animals. Aim: We sought to investigate the effect of three doses of BPA and NP on the reproductive parameters of rats. Materials and Methods: Adult Wistar male rats weighing 150–200 g were used for a consecutive 35-day study. BPA and NP were given as gavage in three doses (5, 25, and 125 μg/kg). At the end of the study, the rats were anesthetized and 2 ml blood sample was obtained from the auxiliary venous plexus for the assessment of sex hormone levels. The testes were removed and kept in 10% formalin for the histomorphometric and histopathologic analyses. Results: BPA and NP significantly decreased the body weight of the animals compared to the controls (P < 0.05). The seminiferous tubule diameter and thickness of the seminiferous epithelium were significantly decreased in the groups receiving BPA and NP compared to the control (P < 0.05). The number of seminiferous tubules in every experimental group increased, except for the highest dose of NP (125 μg/kg), which showed a significant difference compared to the controls (P < 0.05). The number of spermatocytes and spermatogonia (54.97 ± 5.824, 35.78 ± 3.956, respectively) in the group receiving NP (125 μg/kg) was significantly decreased compared to the other groups. Serum levels of luteinizing hormone, Follicle stimulating hormone, and testosterone did not show any significant change compared to the controls. Conclusion: Based on the results, all three doses of BPA and NP significantly produced weight loss, as well as destruction of the testis tissue and impairment of the spermatogenesis. PMID:27298816

  11. Comparative Packaging Study

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele H.; Oziomek, Thomas V.

    2009-01-01

    Future long duration manned space flights beyond low earth orbit will require the food system to remain safe, acceptable and nutritious. Development of high barrier food packaging will enable this requirement by preventing the ingress and egress of gases and moisture. New high barrier food packaging materials have been identified through a trade study. Practical application of this packaging material within a shelf life test will allow for better determination of whether this material will allow the food system to meet given requirements after the package has undergone processing. The reason to conduct shelf life testing, using a variety of packaging materials, stems from the need to preserve food used for mission durations of several years. Chemical reactions that take place during longer durations may decrease food quality to a point where crew physical or psychological well-being is compromised. This can result in a reduction or loss of mission success. The rate of chemical reactions, including oxidative rancidity and staling, can be controlled by limiting the reactants, reducing the amount of energy available to drive the reaction, and minimizing the amount of water available. Water not only acts as a media for microbial growth, but also as a reactant and means by which two reactants may come into contact with each other. The objective of this study is to evaluate three packaging materials for potential use in long duration space exploration missions.

  12. Evaluation of an experimental rat model for comparative studies of bleaching agents

    PubMed Central

    Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes, João Eduardo; Briso, André Luiz Fraga

    2016-01-01

    ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents. PMID:27008262

  13. Evaluation of an experimental rat model for comparative studies of bleaching agents

    PubMed Central

    CINTRA, Luciano Tavares Angelo; BENETTI, Francine; FERREIRA, Luciana Louzada; RAHAL, Vanessa; ERVOLINO, Edilson; JACINTO, Rogério de Castilho; GOMES, João Eduardo; BRISO, André Luiz Fraga

    2016-01-01

    ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents. PMID:27119766

  14. Comparison of histomorphometrical data obtained with two different image analysis methods.

    PubMed

    Ballerini, Lucia; Franke-Stenport, Victoria; Borgefors, Gunilla; Johansson, Carina B

    2007-08-01

    A common way to determine tissue acceptance of biomaterials is to perform histomorphometrical analysis on histologically stained sections from retrieved samples with surrounding tissue, using various methods. The "time and money consuming" methods and techniques used are often "in house standards". We address light microscopic investigations of bone tissue reactions on un-decalcified cut and ground sections of threaded implants. In order to screen sections and generate results faster, the aim of this pilot project was to compare results generated with the in-house standard visual image analysis tool (i.e., quantifications and judgements done by the naked eye) with a custom made automatic image analysis program. The histomorphometrical bone area measurements revealed no significant differences between the methods but the results of the bony contacts varied significantly. The raw results were in relative agreement, i.e., the values from the two methods were proportional to each other: low bony contact values in the visual method corresponded to low values with the automatic method. With similar resolution images and further improvements of the automatic method this difference should become insignificant. A great advantage using the new automatic image analysis method is that it is time saving--analysis time can be significantly reduced. PMID:17387585

  15. EFFECT OF GLABRIDIN AND GLYCYRRHIZIC ACID ON HISTOMORPHOMETRIC PARAMETERS OF BONES IN OVARIECTOMIZED RATS.

    PubMed

    Klasik-Ciszewska, Sylwia; Kaczmarczyk-Sedlak, Ilona; Wojnar, Weronika

    2016-01-01

    Licorice is a medicinal plant showing many therapeutic activities. Its roots contain numerous pharmacologically active compounds such as a triterpenoid saponin--glycyrrhizic acid and an isoflavan--glabridin. There are reports indicating that glabridin exhibits estrogen-like activity, therefore it can be classified into phytoestrogens, which may soothe menopause symptoms including postmenopausal osteoporosis. Due to this fact, the aim of the presented study was to evaluate the effect of glabridin and glycyrrhizic acid on histomorphometric parameters of bones in rats with ovariectomy-induced osteoporosis. The animals were divided into 6 group: (C)--control rats, (OVX)--ovariectomized rats, (OVX + E)--ovariectomized rats receiving estradiol at a dose of 0.1 mg/kg p.o., (OVX + G)--ovariectomized rats receiving genistein at a dose of 5 mg/kg p.o., (OVX + GL --ovariectomized rats treated with glabridin at a dose of 5 mg/kg p.o. and (OVX + GA)--ovariectomized rat administered with glycyrrhizic acid at a dose of 15 mg/kg p.o. Estradiol and genistein served as the positive controls in the study. Several macrometric and histomorphometric parameters were analyzed in the bones of tested rats. Obtained results indicate that glabridin shows slightly positive effect on osteoporotically changed bone tissue, and glycyrrhizic acid reveals meager influence on skeletal system with no preventive significance. PMID:27180445

  16. Histologic and histomorphometric changes of testis following oral exposure to methyl tertiary-butyl ether in adult rat.

    PubMed

    Gholami, S; Ansari-Lari, M; Khalili, L

    2015-01-01

    Methyl tertiary-butyl ether (MTBE) is used to reduce carbon monoxide and ozone in urban air and to boost fuel octane. There is a lack of knowledge in the literature about the histomorphometric changes of the testis following exposure to MTBE. Therefore, this experimental study was performed to determine the effect of oral exposure to MTBE on histologic and histomorphometric changes of testis in adult rat. A total of 25 adult male Sprague-Dawley rats were randomly divided into five equal experimental groups: control, almond oil and three treatment groups which received 400, 800 and 1600 mg/kg/day MTBE in almond oil by gavages for 30 consecutive days. Histomorphometric analysis showed no significant difference in absolute and relative testis weight, connective tissue thickness, germinal epithelium height, tunica albuginea thickness and Sertoli cell numbers between experimental groups (P>0.05). However, trend analysis showed that the seminiferous tubule diameter increased and interstitial cell numbers as well as spermatocyte and spermatid cell numbers decreased significantly in MTBE treated groups (P<0.05). It may be concluded that MTBE could exert adverse effects on spermatogenic cells in adult rat. Whether the observed changes in the present study are due to the direct effect of MTBE via passing blood-testis barrier or its indirect effect through another mechanism should be elucidated in future studies. PMID:27175191

  17. The Effects of Pyridaben Pesticide on the Histomorphometric, Hormonal Alternations and Reproductive Functions of BALB/c Mice

    PubMed Central

    Ebadi Manas, Ghodrat; Hasanzadeh, Shapour; Parivar, Kazem

    2013-01-01

    Objective(s): The adverse effects of pyridaben on reproductive system in male animals are not well established. This study was designed to elucidate how pyridaben can effects the histomorphometric, hormonal alternations and reproductive functions of BALB/c mice. Materials and Methods: For this study, 80 adult and apparently healthy male BALB/c mice were divided into three groups Viz, control, test group 1 and test group 2. Test groups 1 and 2 were received the toxin at doses of 53 mg/kg. BW, and 212 mg/kg. BW, respectively. The experiment period for both groups was 10, 25 and 45 days. Results: The levels of FSH, LH and testosterone were significantly (P<0.05) decreased on the dose and time dependant means. The levels of the ROS and NOS were significantly (P<0.05) increased in all test groups. The percent body weight gains significantly (P<0.05) reduced, whereas weights significantly (P<0.05) increased in test groups in a dose and time dependant manner. The histomorphometric and stereologic findings, including diameters of somniferous tubules, thickness of somniferous tubules epithelium, the leydig's cell distribution, TDI, SI, RI revealed that, all these parameters are also significantly (P<0.05) reduces in test groups in a dose and time dependant manner. Conclusion: Pyridaben causes histomorphometric and stereologic changes in testis, as well as hormonal and reproductive functional alternations in BALB/c mice. PMID:24379962

  18. Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses.

    PubMed

    Dursun, Ceyda Kanli; Dursun, Erhan; Eratalay, Kenan; Orhan, Kaan; Tatar, Ilkan; Baris, Emre; Tözüm, Tolga Fikret

    2016-03-01

    The aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000-2000 μm) and xenograft (1 g) + PTG (granule size 700-1000 μm, pore size >50 μm) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus. PMID:26872278

  19. Histomorphometric analysis of rat skeleton following spaceflight

    NASA Technical Reports Server (NTRS)

    Wronski, T. J.; Morey-Holton, E. R.; Doty, S. B.; Maese, A. C.; Walsh, C. C.

    1987-01-01

    Male Sprague-Dawley rats were placed in orbit for 7 days aboard the space shuttle. Bone histomorphometry was performed in the long bones and lumbar vertebrae of flight rats and compared with data derived from ground-based control rats. Trabecular bone mass was not altered during the 1st wk of weightlessness. Strong trends were observed in flight rats for decreased periosteal bone formation in the tibial diaphysis, reduced osteoblast size in the proximal tibia, and decreased osteoblast surface and number in the lumbar vertebra. For the most part, histological indexes of bone resorption were normal in flight rats. The results indicate that 7 days of weightlessness are not of sufficient duration to induce histologically detectable loss of trabecular bone in rats. However, cortical and trabecular bone formation appear to be diminished during the 1st wk of spaceflight.

  20. Effect of different storage media on the regenerative potential of autogenous bone grafts: a histomorphometrical analysis in rabbits.

    PubMed

    Rocha, Flaviana Soares; Batista, Jonas Dantas; Zanetta-Barbosa, Darceny; Dechichi, Paula

    2013-12-01

    The success of autogenous bone graft is related to the graft cell viability. In bone-grafting procedures, harvested grafts are often maintained in extraoral media while the recipient site is prepared. The aim of this study was to evaluate in vivo the effect of storage media over autogenous bone grafts during the transsurgical time. Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was immediately fixed in the mandibular angle (control group), and the other was maintained in air exposure (dry group), 0.9% NaCl solution (saline group), or platelet-poor plasma (PPP group) during 30 minutes and stabilized in the symmetrical location of control grafts. After 28 days, the animals were euthanized and the bone fragments were removed, demineralized, and embedded in paraffin. Histological evaluation was performed under light microscope. Empty lacunae and bone graft area quantification were carried out for the sections. The histomorphometrical analysis revealed reduction of the graft area and increase of empty lacunae in the dry group when compared with control. No significant differences were found in the number of empty lacunae or bone graft area between the saline group and its control and also between the PPP group and its control. The dry group showed more empty lacunae and less graft area than the saline and PPP groups. In accordance with the results, PPP and physiologic solution demonstrated osteocyte preservation and bone graft area maintenance, being satisfactory storage media for autogenous bone grafts during the transsurgical period. PMID:21905882

  1. Effects of Immediate Orthodontic and Orthopedic Forces on Peri-Miniscrew Bones: Histomorphologic and Histomorphometric Assessment in Dogs

    PubMed Central

    Rismanchian, Mansour; Raji, Sayed Hamid; Teimori Rik, Danesh; Mohammad Razavi, Sayed; Khalighinejad, Navid; Goroohi, Hossein; Badrian, Hamid

    2012-01-01

    Aim. The aim of this study was histomorphologic and histomorphometric evaluation of peri-screw bone after immediate orthodontic and orthopedic forces and comparing them with a control group. Materials and Methods. 18 dual-top miniscrews were inserted in the premolar region of three Iranian dogs. Screws were divided into three groups: (1) the first group undergoing immediate orthodontic force of 300 cN, (2) the second group undergoing immediate orthopedic force of 600 cN and (3) a control group. Screws were explanted with adequate amount of surrounding bone after three months. Bone-screw contact (BSC), percentage of lamellar bone, and percentage of woven bone were evaluated. Wilcoxon and Man Whitney tests were used to analyze the data using SPSS software ver. 15 (α = 0.05). Results. There was no significant difference among the groups in terms of bone-screw contact (P  value = 0.42), percentage of lamellar bone (P  value = 0.83), and percentage of woven bone (P  value = 0.88). Conclusion. By applying orthodontic and orthopedic forces to mini-screws the quality of surrounding bone and osseointegration will not be affected. Clinical Significance. Application of force to mini-screws is helpful in orthodontic-screw therapies. PMID:23319949

  2. Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

    PubMed Central

    Maiorana, Carlo; Beretta, Mario; Battista Grossi, Giovanni; Santoro, Franco; Scott Herford, Alan; Nagursky, Heiner; Cicciù, Marco

    2011-01-01

    Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructure very similar to that of human hydroxyapatite. An original technique provides for the application of a thin layer of anorganic bovine bone granules and a collagen membrane on the top of the corticocancellous onlay bone grafts to reduce in a remarkable way the graft resorption due to remodeling. The results of a clinical prospective study and a histomorphometric analysis done on autogenous grafts harvested from the iliac crest showed that the proposed technique is able to maintain the original bone volume of the corticocancellous blocks. PMID:21566694

  3. Titanium implants with two different surfaces: Histomorphologic and histomorphometric evaluation in rabbit tibia.

    PubMed

    Biasotto, M; Sandrucci, M A; Antoniolli, F; Stebel, M; Grill, V; Di Lenarda, R; Dorigo, E

    2005-01-01

    This study aimed to compare two different implant surface treatments of the implant system Bi-Implant (Plan 1 Health): one surface sandblasted with hydroxyapatite (HA) (Osseogrip(R)) and one machined surface. Histomorphologic and histomorphometric evaluations of the bone healing at the interface between a titanium implant and bone were performed using a light microscopic technique. Twenty-four commercially pure titanium implants with a smooth surface and 24 implants with a sandblasted surface were inserted in the tibias of 12 rabbits. The 12 rabbits were divided into three groups, each consisting of four animals, were sacrificed at 4 weeks (I group), 8 weeks (II group) and 12 weeks (III group) after the insertion of the bio-material. The results emphasized that in the sections examined with the light microscope, the bone was in intimate contact with the implant surface and the bone surrounding the implants was mostly lamellar. After 4 weeks, mature bone tightly surround-ing some areas of the implant perimeter was observed. The implant with the Osseogrip(R) surface showed an average percentage of bone-implant contact (%BIC) equal to 33%, while the one with the machined surface showed a %BIC equal to 17%. After 8 weeks, a progressive increase in mineralized bone surrounding the implant surface was detected, making the results of the machined surface superposable to the Osseogrip(R) surface results (48 and 44%). After 12 weeks, the implants with the machined surface exhibited close contact with the bone tissue corresponding to 62% of their perimeter, while for the implants with the Os-seogrip(R) surface the surface contact was 67% of the implant surface. The morphometric evaluation of %BIC at the three time points evidenced an increase in bone-titanium contact over time on both machined and Osseogrip(R) surfaces. Moreover, implants with rough surfaces demonstrated better behavior than the implants with the machined surface when taking into account the earlier

  4. Histomorphometric and biomechanical analyses of osseointegration of four different orthodontic mini implant surfaces

    NASA Astrophysics Data System (ADS)

    Yadav, Sumit

    Objective: To evaluate the osseointegration potential of four different surfaces of mini-implants. We hypothesized that mini-implants surface roughness alters the intrinsic biomechanical properties of the bone integrated to titanium. Materials and Methods: Mini implants and circular discs were made from alloy Ti6Al4V grade 5. On the basis of surface treatment study was divided into 4 groups: Group 1: Machined: no surface treatment, Group 2: Acid etched: with hydrochloric acid, Group 3: Grit Blasted with alumina and Group 4: Grit blasted +Acid etched. Surface roughness parameters (mean surface roughness: Ra and Quadratic Average roughness: Rq) of the four discs from each group were measured by the optical profilometer. Contact angle measurement of 3 discs from each group was done with a Goniometer. Contact angle of liquids with different hydrophobicity and hydrophilicity were measured. 128 mini implants, differing in surface treatment, were placed into the tibias and femurs of 8 adult male New Zealand white rabbits. Biomechanical properties (Removal torque and hardness) measurements and histomorphometric observations were measured. Results: Ra and Rq of groups were: Machined (1.17+/-0.11, 2.59+/-0.09) Acid etched (1.82+/-0.04, 3.17+/-0.13), Grit blasted (4.83+/-0.23, 7.04+/-0.08), Grit blasted + Acid etched (3.64+/-0.03, 4.95+/-0.04) respectively. Group 4 had significantly (p=0.000) lower Ra and Rq than Group 3. The interaction between the groups and liquid was significant. Group 4 had significantly lower contact angle measurements (40.4°, 26.9°), both for blood and NaCl when compared to other three groups (p≤0.01). Group 4 had significantly higher torque than Group 3 (Tibia: 13.67>9.07N-cm; Femur: 18.21>14.12N-cm), Group 4 (Tibia: 13.67>9.78N-cm; Femur: 18.21>12.87N-cm), and machined (Tibia: 13.67>4.08N-cm; Femur: 18.21>6.49N-cm). SEM analysis reveals significantly more bone implant gap in machined implant surfaces than treated implant surfaces. Bone to implant

  5. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals

    PubMed Central

    Sprecher, Christoph M.; Schmidutz, Florian; Helfen, Tobias; Richards, R. Geoff; Blauth, Michael; Milz, Stefan

    2015-01-01

    Abstract Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred. The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals. The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis. At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side. This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus. PMID:26705200

  6. Sex work: a comparative study.

    PubMed

    McCarthy, Bill; Benoit, Cecilia; Jansson, Mikael

    2014-10-01

    Explanations of adult involvement in sex work typically adopt one of two approaches. One perspective highlights a variety of negative experiences in childhood and adolescence, including physical and sexual abuse, family instability, poverty, associations with "pimps" and other exploiters, homelessness, and drug use. An alternative account recognizes that some of these factors may be involved, but underscores the contribution of more immediate circumstances, such as current economic needs, human capital, and employment opportunities. Prior research offers a limited assessment of these contrasting claims: most studies have focused exclusively on people working in the sex industry and they have not assessed the independent effects of life course variables central to these two perspectives. We add to this literature with an analysis that drew on insights from life course and life-span development theories and considered the contributions of factors from childhood, adolescence, and adulthood. Our comparative approach examined predictors of employment in sex work relative to two other low-income service or care work occupations: food and beverage serving and barbering and hairstyling. Using data from a study of almost 600 workers from two cities, one in Canada and the other in the United States, we found that both immediate circumstances and negative experiences from early life are related to current sex work involvement: childhood poverty, abuse, and family instability were independently associated with adult sex work, as were limited education and employment experience, adult drug use, and marital status. PMID:24671729

  7. Bone marrow stem cells assuage radiation-induced damage in a murine model of distraction osteogenesis: A histomorphometric evaluation.

    PubMed

    Zheutlin, Alexander R; Deshpande, Sagar S; Nelson, Noah S; Kang, Stephen Y; Gallagher, Kathleen K; Polyatskaya, Yekaterina; Rodriguez, Jose J; Donneys, Alexis; Ranganathan, Kavitha; Buchman, Steven R

    2016-05-01

    The purpose of this study is to determine if intraoperatively placed bone marrow stem cells (BMSCs) will permit successful osteocyte and mature bone regeneration in an isogenic murine model of distraction osteogenesis (DO) following radiation therapy (XRT). Lewis rats were split into three groups, DO only (Control), XRT followed by DO (xDO) and XRT followed by DO with intraoperatively placed BMSCs (xDO-BMSC). Coronal sections from the distraction site were obtained, stained and analyzed via statistical analysis with analysis of variance (ANOVA) and subsequent Tukey or Games-Howell post-hoc tests. Comparison of the xDO-BMSC and xDO groups demonstrated significantly improved osteocyte count (87.15 ± 10.19 vs. 67.88 ± 15.38, P = 0.00), and empty lacunae number (2.18 ± 0.79 vs 12.34 ± 6.61, P = 0.00). Quantitative analysis revealed a significant decrease in immature osteoid volume relative to total volume (P = 0.00) and improved the ratio of mature woven bone to immature osteoid (P = 0.02) in the xDO-BMSC compared with the xDO group. No significant differences were found between the Control and xDO-BMSC groups. In an isogenic murine model of DO, BMSC therapy assuaged XRT-induced cellular depletion, resulting in a significant improvement in histological and histomorphometric outcomes. PMID:27059203

  8. Clinical, Histological, and Histomorphometric Evaluation of Demineralized Freeze-Dried Cortical Block Allografts for Alveolar Ridge Augmentation.

    PubMed

    Aslan, Elcin; Gultekin, Alper; Karabuda, Cuneyt; Mortellaro, Carmen; Olgac, Vakur; Mijiritsky, Eitan

    2016-07-01

    Autogenous bone-block grafts are the "gold standard" for block bone grafting, but have several disadvantages. Allografts have the potential to overcome these disadvantages. The purpose of this study was to evaluate the clinical and histomorphometric features of demineralized freeze-dried cortical block allografts (DCBA) used for ridge augmentation. Eleven patients who showed bone deficiencies of <5 mm in the horizontal plane were included in this study. The recipient sites were reconstructed with DCBA. The primary outcomes of interest were bone-width measurements, postoperative clinical evaluations, and histomorphometric analysis of the biopsy samples collected during the implant surgery. Clinical analysis showed that the mean gain in horizontal bone was 1.65 ± 0.14 mm, and that the mean percentage of graft resorption was 5.39 ± 2.18%. On postoperative day 7, edema, pain, and bruising were observed in 18.2%, 0%, and 9.1% of the patients, respectively. In the biopsy samples, the mean percentages of newly formed bone, residual block allograft, and marrow and connective tissue were 40.30 ± 24.59%, 40.39 ± 21.36%, and 19.30 ± 15.07%, respectively. All of the block grafts were successfully integrated into the recipient sites. DCBA may be a viable alternative for treating both deficient maxillary and mandibular alveolar ridges. PMID:27380561

  9. Comparative study of membranes induced by PMMA or silicone in rats, and influence of external radiotherapy.

    PubMed

    de Monès, Erwan; Schlaubitz, Silke; Oliveira, Hugo; d'Elbée, Jean-Marie; Bareille, Reine; Bourget, Chantal; Couraud, Lionel; Fricain, Jean-Christophe

    2015-06-01

    The induced membrane technique has been used for long bone defect reconstruction after traumatism. One of the major drawbacks of this method is the difficult removal of the polymethyl methacrylate spacer after membrane formation. We therefore replaced the stiff PMMA spacer with a semi-flexible medical grade silicone spacer. This study aimed to compare subcutaneously formed membranes, induced by PMMA and silicone, in the irradiated or not irradiated areas within 28 rats that received the spacers. Histological analysis was performed to evaluate the composition of the membrane and to quantify the amount of vessels. Histomorphometric measurements were used to evaluate membranes' thickness, while fibrosis and inflammation were scored. The expression of VEGF and BMP-2 in lysates of the crushed membranes was determined by Western blotting. ALP expression was analyzed in HBMSC cultures in contact with the same lysates. Non-irradiated membranes induced by the two spacer types were non-inflammatory, fibrous and organized in layers. Irradiation did not change the macroscopic properties of membranes that were induced by silicone, while PMMA induced membranes were sensitive to the radiotherapy, resulting in thicker, strongly inflammatory membranes. Irradiated membranes showed an overall reduced osteogenic potential. Medical grade silicone is safe for the use in radiotherapy and might therefore be of great advantage for patients in need of cancer treatment. PMID:25770925

  10. The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with miniplates: a histological and histomorphometric study on rabbits.

    PubMed

    Pinheiro, Antonio L B; Aciole, Gilberth Tadeu Santos; Ramos, Thais Andrade; Gonzalez, Tayná Assunção; da Silva, Laís Nogueira; Soares, Luiz G Pinheiro; Aciole, Jouber Mateus Santos; dos Santos, Jean Nunes

    2014-01-01

    The aim of the present study was to assess, by light microscopy and histomorphometry, the repair of surgical fractures fixed with internal rigid fixation (IRF) treated or not with IR laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) = 16 J/cm(2), ϕ = 0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into 5 groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libidum. The fractures in groups II, III, IV, and V were fixed with miniplates. Animals in groups III and V were grafted with hydroxyapatite and GBR technique used. Animals in groups IV and V were irradiated at every other day during two weeks (4 × 4 J/cm(2), 16 J/cm(2) = 112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken, routinely processed to wax, cut and stained with HA and Sirius red, and used for histological assessment. The results of both analyses showed a better bone repair on all irradiated subjects especially when the biomaterial and GBR were used. In conclusion, the results of the present investigation are important clinically as they are suggestive that the association of hydroxyapatite, and laser light resulted in a positive and significant repair of complete tibial fractures treated with miniplates. PMID:23649614

  11. Comparative Studies in Special Education.

    ERIC Educational Resources Information Center

    Mazurek, Kas, Ed.; Winzer, Margret A., Ed.

    This text presents 26 case studies which examine special education provisions for children in the world today. The reports focus on the current state of special education in selected nations and major issues and controversies in the field of special education within those nations. Each case study addresses the following themes: (1) prevalence of…

  12. Comparative Studies of Acculturative Stress.

    ERIC Educational Resources Information Center

    Berry, J. W.; And Others

    1987-01-01

    Studies of acculturative stress are reported from Canada. The reduction in health status among people undergoing acculturation has psychological, somatic, and social aspects. The stress varies across types of groups and individual differences. Further study is needed to determine variations across host societies. (VM)

  13. Variation in osteon histomorphometrics and their impact on age-at-death estimation in older individuals.

    PubMed

    Goliath, Jesse R; Stewart, Marissa C; Stout, Sam D

    2016-05-01

    Histomorphometric studies have reported relations between osteon size and age; however, data focused on the shape of osteons is sparse. The purpose of this study was to determine how osteon circularity (On.Cr) varies with age in different skeletal elements. Regression analysis was used to evaluate the relationship between age and osteon shape and size. We hypothesized that age would be negatively related to osteon size (area, On.Ar) and positively related to osteon shape (On.Cr). On.Cr and On.Ar were determined for the ribs and femora of 27 cadaveric specimens with known age-at-death. As predicted, age was significantly related to osteon size and shape for both the femur and rib. With age, there was a decrease in size and an increase in circularity. No relationship between sex and On.Cr was detected. An age predicting model, including On.Cr, On.Ar and OPD, is proposed to improve our ability to estimate age-at-death, especially for older individuals. PMID:27021159

  14. Histomorphometric Evaluation of the Small Coronary Arteries in Rats Exposed to Industrial Noise

    PubMed Central

    Lousinha, Ana; Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Maria João; Brito, José; Martins dos Santos, José

    2015-01-01

    Morphological changes induced by industrial noise (IN) have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls) were selected. The mean lumen-to-vessel wall (L/W) and mean vessel wall-to-perivascular tissue (W/P) ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687) and time variations in this ratio were non-significant (p = 0.110). In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001), with significant time variations (p = 0.004). Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis. PMID:25946344

  15. Effect of Sodium Fluoride on Bone Biomechanical and Histomorphometric Parameters and on Insulin Signaling and Insulin Sensitivity in Ovariectomized Rats.

    PubMed

    de Cássia Alves Nunes, Rita; Chiba, Fernando Yamamoto; Pereira, Amanda Gomes; Pereira, Renato Felipe; de Lima Coutinho Mattera, Maria Sara; Ervolino, Edilson; Louzada, Mário Jefferson Quirino; Buzalaf, Marília Afonso Rabelo; Silva, Cristina Antoniali; Sumida, Doris Hissako

    2016-09-01

    Osteoporosis is a systemic disease characterized by bone degradation and decreased bone mass that promotes increased bone fragility and eventual fracture risk. Studies have investigated the use of sodium fluoride (NaF) for the treatment of osteoporosis. However, fluoride can alter glucose homeostasis. The aim of this study was to evaluate the effects of NaF intake (50 mg/L) from water on the following parameters of ovariectomized (OVX) rats: (1) tyrosine phosphorylation status of insulin receptor substrate (pp185 (IRS-1/IRS-2)) in white adipose tissue; (2) insulin sensitivity; (3) plasma concentrations of glucose, insulin, total cholesterol, triglyceride, TNF-α, IL-6, osteocalcin, calcium, and fluoride; (4) bone density and biomechanical properties in the tibia; and (5) tibia histomorphometric analysis. Fifty-two Wistar rats (2 months old) were ovariectomized and distributed into two groups: control group (OVX-C) and NaF group (OVX-F), which was subjected to treatment with NaF (50 mg/L) administered in drinking water for 42 days. The chronic treatment with NaF promoted (1) a decrease in pp185 (IRS-1/IRS-2) tyrosine phosphorylation status after insulin infusion in white adipose tissue and in insulin sensitivity; (2) an increase in the plasma concentration of insulin, fluoride, osteocalcin, calcium, triglyceride, VLDL-cholesterol, TNF-α, and IL-6; (3) a reduction in the trabecular width, bone area, stiffness, maximum strength, and tenacity; (4) no changes in body weight, food and water intake, plasma glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, bone mineral content, and bone mineral density. It was concluded that chronic treatment with NaF (50 mg/L) in OVX rats causes a decrease in insulin sensitivity, insulin signaling transduction, and biochemical, biomechanical, and histomorphometric bone parameters. PMID:26876375

  16. Histomorphometric analysis of irradiated recipient vessels and transplant vessels of free flaps in patients undergoing reconstruction after ablative surgery.

    PubMed

    Schultze-Mosgau, S; Erbe, M; Keilholz, L; Radespiel-Tröger, M; Wiltfang, J; Minge, N; Neukam, F W

    2000-04-01

    The aim of the study was to investigate, histomorphometrically, quantitative and qualitative changes in irradiated neck recipient vessels and transplant vessels used for microsurgical anastomoses in free flaps in patients undergoing preoperative radiotherapy and chemotherapy. In 55 patients receiving 42 radial forearm flaps, 6 latissimus dorsi flaps, 6 osteomyocutaneous fibula grafts and 1 lateral arm flap, a total of 220 vessels were obtained from neck recipient vessels and transplant vessels during anastomosis. Three groups were formed: Group 1 (16 patients) treated with no radiotherapy or chemotherapy; Group 2 (20 patients) treated with preoperative irradiation (40-50 Gy) and chemotherapy (800 mg/m2 5-FU and 20 mg/m2 cisplatin) 1.5 months prior to surgery; Group 3 (19 patients) treated with radiotherapy (60-70 Gy) (median interval 78.7 months; IQR 31.3 months) prior to surgery. From each of the 220 vessel specimens, 3 sections each were histomorphometrically investigated, both qualitatively and quantitatively. To evaluate these changes as a function of age, radiation dose and chemotherapy, a statistical analysis was performed using analysis of covariance and chi-square tests. In Group 3, qualitative changes (intima dehiscence, hyalinosis) were found in recipient arteries significantly more frequently (25%, P=0.009) than in Groups 1 and 2. For Group 3 recipient arteries, histomorphometry revealed a significant decrease in the ratio of media area/total vessel area (median 0.53, IQR 0.10) in comparison with Group 1 (P= 0.02) (median 0.60, IQR 0.29) and Group 2 (P=0.046) (median 0.59, IQR 0.10). No significant differences were found between the vessels of Groups 1 and 2 (P= 0.48). Age and chemotherapy did not appear to have a significant influence on vessel changes in this study. PMID:10833147

  17. Histomorphometric Evaluation of the Effects of Various Diode Lasers and Force Levels on Orthodontic Mini Screw Stability

    PubMed Central

    Isman, Eren; Taner, Lale; Kurkcu, Mehmet

    2015-01-01

    Abstract Objective The purpose of this study was to evaluate the effects of different laser dose and force levels on the stability of orthodontic mini screws used for anchorage, by histomorphometric analyses. Background data Low-level laser therapy speeds up blood flow, improves the mechanism of the revitalization processes, reduces the risk of infection, boosts metabolic activities, and accelerates the healing of the damaged tissue. Although there are many research studies about low-level laser therapy applications in a variety of areas, no investigations were found concerning mini screw stability using various laser dose levels with different force level applications. Methods Seventeen New Zealand white rabbits were used. A total of 68 cylindrical, self-drilling orthodontic mini screws were threaded at the fibula. Experimental subjects were divided into six groups; force application was not performed in the first three groups, whereas 150g of force was applied via nickel-titanium closed-coil springs placed between two mini screws in the other three groups. Measurements of the initial torque values (10 Ncm) were manipulated by a digital portable torque gauge. Various low-level laser doses were applied to the groups during the postoperative 10 days. After 4 weeks, bone-to-implant contact and cortical bone thickness were histomorphometrically analyzed. Results In the 150g force plus 20 J/cm2 dosage group, the highest bone-to-implant contact values were observed. (p<0.05) There were no statistically significant correlations between cortical bone thickness and bone-to-implant contact values; on the other hand, no significant difference was found among the same groups in terms of cortical bone thickness values (p>0.05). Conclusions Low-level laser therapy was noticed to induce the mini screw–bone contact area. Low-level laser therapy may be a supplementary treatment method to increase the stability of the orthodontic mini screw. PMID:25594769

  18. Histomorphometric comparison of the human, swine, and ovine collecting systems.

    PubMed

    Simões, Michele; de Souza, Diogo B; Gallo, Carla B M; Pereira-Sampaio, Marco A; Costa, Waldemar S; Sampaio, Francisco J

    2016-07-01

    The ovine kidney has been recently determined to be a better model than the swine kidney for the study of collecting system healing after partial nephrectomy. However, there is no histological study comparing the collecting systems of these species. To compare human, swine, and ovine collecting systems using histomorphometry. The collecting systems of 10 kidneys from each species (human, swine, and ovine) were processed for histomorphometry. The thickness of the three layers (mucosal connective tissue, submucosal muscular, and adventitial connective tissue) were measured. The densities of smooth muscle fibers, elastic system fibers, and cells were also measured. Additionally, blood vessel density in the adventitial connective tissue was measured. Analysis of the collecting systems from the three species presented several differences. The adventitial connective tissue from the swine samples was thicker, with more blood vessels and smooth muscle fibers, compared with that from the human and ovine samples. Swine also had higher density of elastic fibers on the submucosal muscular layer. Ovine and human collecting systems shared several similar features, such as blood vessel and elastic fiber density in all layers and the density of cellular and muscular fibers in the submucosal muscular and adventitial connective tissue layers. The collecting system of the ovine kidney is more similar to that of the human kidney compared with that of the swine kidney. This may explain the differences between the healing mechanisms in swine and those in humans and sheep after partial nephrectomy. Anat Rec, 299:967-972, 2016. © 2016 Wiley Periodicals, Inc. PMID:27111677

  19. Inner architecture of vertebral centra in terrestrial and aquatic mammals: a two-dimensional comparative study.

    PubMed

    Dumont, Maitena; Laurin, Michel; Jacques, Florian; Pellé, Eric; Dabin, Willy; de Buffrénil, Vivian

    2013-05-01

    Inner vertebral architecture is poorly known, except in human and laboratory animals. In order to document this topic at a broad comparative level, a 2D-histomorphometric study of vertebral centra was conducted in a sample of 98 therian mammal species, spanning most of the size range and representing the main locomotor adaptations known in therian taxa. Eleven variables relative to the development and geometry of trabecular networks were extracted from CT scan mid-sagittal sections. Phylogeny-informed statistical tests were used to reveal the respective influences of phylogeny, size, and locomotion adaptations on mammalian vertebral structure. The use of random taxon reshuffling and squared change parsimony reveals that 9 of the 11 characteristics (the two exceptions are total sectional area and structural polarization) contain a phylogenetic signal. Linear discriminant analyses suggest that the sampled taxa can be arranged into three categories with respect to locomotion mode: a) terrestrial + flying + digging + amphibious forms, b) coastal oscillatory aquatic taxa, and c) pelagic oscillatory aquatic forms represented by oceanic cetaceans. Pairwise comparison tests and linear regressions show that, when specific size increases, the length of trabecular network (Tt.Tb.Le), as well as trabecular proliferation in total sections (Pr.Tb.Tt), increase with positive allometry. This process occurs in all locomotion categories but is particularly pronounced in pelagic oscillators. Conversely, mean trabecular width has a lesser increase with size in pelagic oscillators. Trabecular orientation is not influenced by size. All tests were corrected for multiple testing. By using six structural variables or indices, locomotion mode can be predicted with a 97.4% success rate for terrestrial forms, 66.7% for coastal oscillatory, and 81.3% for pelagic oscillatory. The possible functional meaning of these results and their potential use for paleobiological inference of locomotion in

  20. Histomorphometric changes in the perirenal adipocytes of adrenalectomized rats treated with dexamethasone

    PubMed Central

    Ahmad, Fairus; Soelaiman, Ima Nirwana; Ramli, Elvy Suhana Mohd; Hooi, Tan Ming; Suhaimi, Farihah H

    2011-01-01

    INTRODUCTION: Prolonged steroid treatment administered to any patient can cause visceral obesity, which is associated with metabolic disease and Cushing's syndrome. Glucocorticoids have a profound negative effect on adipose tissue mass, giving rise to obesity, which in turn is regulated by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Adrenalectomized rats treated with dexamethasone exhibited an increase in visceral fat deposition but not in body weight. OBJECTIVES: The main aim of this study was to determine the effect of dexamethasone on the histomorphometric characteristics of perirenal adipocytes of adrenalectomized, dexamethasone-treated rats (ADR+Dexa) and the association of dexamethasone treatment with the expression and activity of 11β-hydroxysteroid dehydrogenase type 1 (11β- hydroxysteroid dehydrogenase type 1). METHODS: A total of 20 male Sprague Dawley rats were divided into 3 groups: a baseline control group (n = 6), a sham-operated group (n = 7) and an adrenalectomized group (n = 7). The adrenalectomized group was given intramuscular dexamethasone (ADR+Dexa) 2 weeks post adrenalectomy, and the rats from the sham-operated group were administered intramuscular vehicle (olive oil). RESULTS: Treatment with 120 µg/kg intramuscular dexamethasone for 8 weeks resulted in a significant decrease in the diameter of the perirenal adipocytes (p<0.05) and a significant increase in the number of perirenal adipocytes (p<0.05). There was minimal weight gain but pronounced fat deposition in the dexamethasone-treated rats. These changes in the perirenal adipocytes were associated with high expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1. CONCLUSIONS: In conclusion, dexamethasone increased the deposition of perirenal fat by hyperplasia, which causes increases in the expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1 in adrenalectomized rats. PMID:21789391

  1. Teaching the Comparative Approach to American Studies.

    ERIC Educational Resources Information Center

    Seaberg, Stanley

    The rationale behind this book of five suggested or sample comparative units contains several elements: 1) an interdisciplinary social science approach to studying the American past, present, and future; and 2) a view of our country's history in terms of a world setting and in the light on contemporary concerns. The global comparative method…

  2. Comparative Environmental Threat Analysis: Three Case Studies.

    ERIC Educational Resources Information Center

    Latour, J. B.; Reiling, R.

    1994-01-01

    Reviews how carrying capacity for different environmental problems is operationalized. Discusses whether it is possible to compare threats, using the exceeding of carrying capacity as a yardstick. Points out problems in comparative threat analysis using three case studies: threats to European groundwater resources, threats to ecosystems in Europe,…

  3. Comparative studies of gene regulatory mechanisms.

    PubMed

    Pai, Athma A; Gilad, Yoav

    2014-12-01

    It has become increasingly clear that changes in gene regulation have played an important role in adaptive evolution both between and within species. Over the past five years, comparative studies have moved beyond simple characterizations of differences in gene expression levels within and between species to studying variation in regulatory mechanisms. We still know relatively little about the precise chain of events that lead to most regulatory adaptations, but we have taken significant steps towards understanding the relative importance of changes in different mechanisms of gene regulatory evolution. In this review, we first discuss insights from comparative studies in model organisms, where the available experimental toolkit is extensive. We then focus on a few recent comparative studies in primates, where the limited feasibility of experimental manipulation dictates the approaches that can be used to study gene regulatory evolution. PMID:25215415

  4. The Use of Platelet-Rich Fibrin in Combination With Biphasic Calcium Phosphate in the Treatment of Bone Defects: A Histologic and Histomorphometric Study☆

    PubMed Central

    Bölükbaşı, Nilüfer; Yeniyol, Sinem; Tekkesin, Merva Soluk; Altunatmaz, Kemal

    2013-01-01

    Background Platelet-rich fibrin (PRF) is a leukocyte and platelet concentrate containing many growth factors. Its potential for hard tissue augmentation as a sole grafting material or in combination with other grafting materials has been investigated in many studies. Objective The aim of this histologic study was to evaluate the efficacy of PRF mixed with biphasic calcium phosphate (BCP) on bone regeneration in surgically created bone defects. Methods Defects 5 mm in diameter were created in both tibias of 6 sheep. The defects were left empty or grafted with BCP, PRF, or BCP+PRF. Animals were killed at 10, 20, and 40 days. The specimens underwent histologic and histomorphometric analysis. Results None of the groups displayed any signs of necrosis. Inflammation was observed in all groups at 10 days; 2 specimens of PRF+BCP and all empty defects showed inflammatory cell infiltration at 20 days. During the 40-day evaluation period, the PRF+BCP group showed the highest ratios of new bone. The other 3 groups showed statistically similar results. In the BCP and PRF+BCP groups, the residual graft ratios were decreased at consecutive time intervals. The difference between the 2 groups was not statistically significant during follow-up. Conclusions The current study revealed a histomorphometric increase in bone formation with the addition of PRF to BCP in surgically created defects in sheep tibia. PMID:24465037

  5. Histomorphometric evidence of deleterious effect of aluminum on osteoblasts.

    PubMed

    de Vernejoul, M C; Belenguer, R; Halkidou, H; Buisine, A; Bielakoff, J; Miravet, L

    1985-01-01

    Bone histomorphometry was performed in 26 hemodialyzed patients to study the relation between the dynamic parameters of bone formation and aluminum deposition. Patients were divided into two groups according to whether bone formation rate at tissue level (Svft) was above or below normal: 0.089 mu 3/mu 2 per day. The 12 patients who constituted group II, defined by a Svft less than 0.089 mu 3/mu 2 per day, had markedly decreased extent of double-labeled surfaces (m = 1.3 +/- 6.5%), and these were absent in 8 of 12 patients. Osteomalacia, defined by decreased formation with increased mean osteoid thickness (greater than 15 micron), was present in only 3 of 12 patients in group II. The 14 patients who constituted group I, defined by a Svft greater than 0.089 mu 3/mu 2 per day, had both increased total labeled surfaces and mineralization rate. Osteomalacia was present in none of the group I patients. In trabecular bone, group II patients had increased stainable aluminum deposition, compared to group I patients, whether estimated as total stainable aluminum (2.16 +/- 1.34 vs 0.17 +/- 0.28 mm/mm2) or stainable percent of trabecular surfaces (42 +/- 19 vs 4 +/- 5%). This last parameter was inversely related to osteoblastic surfaces (r = -0.49, n = 26, P less than 0.01) and total labeled surfaces (r = -0.72, n = 26, P less than 0.01). Therefore, massive aluminum deposition was not invariably associated with impaired mineralization but with decreased formation due to decreased extent of active formation surfaces. In the group I patients, moderate aluminum deposition was not associated with the mineralization arrest observed in these patients.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2581595

  6. The Influence of Low-Level Laser on Osseointegration Around Machined and Sandblasted Acid-Etched Implants: A Removal Torque and Histomorphometric Analyses.

    PubMed

    Teixeira, Eduardo Rolim; Torres, Marco Antônio Rambo Osório; Meyer, Kleber Ricardo Monteiro; Zani, Sabrina Rebollo; Shinkai, Rosemary Sadami Arai; Grossi, Márcio Lima

    2015-08-01

    Evaluation of the influence of laser application on osseointegration around implants with different surface characteristics is limited. This study aims to evaluate the influence of low-level lasers on the early stages of osseointegration. Ninety-six external hex implants (3.75 mm × 5.0 mm) were placed in 24 rabbits-one machined and one sandblasted acid-etched per tibia. The rabbits were later divided into the laser group, which received a total dose of 24 J/cm(2) of gallium-aluminum-arsenide laser over 15 days, and a control group. At 16 and 30 days after surgery, removal torque and histomorphometric analyses were performed. No statistical differences in removal torque or histomorphometric analyses were verified between laser and control groups regardless of implant surface (P > .05). Time was the only variable presenting significant differences between measurements (P < .05). Low-level laser had no significant short-term effect on bone-to-implant contact and removal torque values regardless of implant surface characteristics. PMID:23834724

  7. Species comparative studies and cognitive development.

    PubMed

    Gómez, Juan-Carlos

    2005-03-01

    The comparative study of infant development and animal cognition brings to cognitive science the promise of insights into the nature and origins of cognitive skills. In this article, I review a recent wave of comparative studies conducted with similar methodologies and similar theoretical frameworks on how two core components of human cognition--object permanence and gaze following--develop in different species. These comparative findings call for an integration of current competing accounts of developmental change. They further suggest that evolution has produced developmental devices capable at the same time of preserving core adaptive components, and opening themselves up to further adaptive change, not only in interaction with the external environment, but also in interaction with other co-developing cognitive systems. PMID:15737820

  8. A Comparative Study of Sparse Associative Memories

    NASA Astrophysics Data System (ADS)

    Gripon, Vincent; Heusel, Judith; Löwe, Matthias; Vermet, Franck

    2016-05-01

    We study various models of associative memories with sparse information, i.e. a pattern to be stored is a random string of 0s and 1s with about log N 1s, only. We compare different synaptic weights, architectures and retrieval mechanisms to shed light on the influence of the various parameters on the storage capacity.

  9. The Student Teaching Experience: A Comparative Study.

    ERIC Educational Resources Information Center

    Butler, Judy D.

    This paper describes a 1996 study that compared the student teaching experiences of a traditional and a nontraditional student to ascertain what differences in their experiences might imply about teacher preparation. The two students kept journals that could be written in at any time of the day. They recorded their impressions of their situation…

  10. A Comparative Study of Sparse Associative Memories

    NASA Astrophysics Data System (ADS)

    Gripon, Vincent; Heusel, Judith; Löwe, Matthias; Vermet, Franck

    2016-07-01

    We study various models of associative memories with sparse information, i.e. a pattern to be stored is a random string of 0s and 1s with about log N 1s, only. We compare different synaptic weights, architectures and retrieval mechanisms to shed light on the influence of the various parameters on the storage capacity.

  11. Intramembranous Bone Healing Process Subsequent to Tooth Extraction in Mice: Micro-Computed Tomography, Histomorphometric and Molecular Characterization

    PubMed Central

    Vieira, Andreia Espindola; Repeke, Carlos Eduardo; Ferreira Junior, Samuel de Barros; Colavite, Priscila Maria; Biguetti, Claudia Cristina; Oliveira, Rodrigo Cardoso; Assis, Gerson Francisco; Taga, Rumio; Trombone, Ana Paula Favaro; Garlet, Gustavo Pompermaier

    2015-01-01

    Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray) characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0h), the development of a provisional immature granulation tissue is evident (7d), characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa), cytokines (TNFα, IL-10), chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4), matrix (Col1a1-2, ITGA4, VTN, MMP1a) and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146) markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14d), characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9), bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST) markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2). No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21d) when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the histomorphometric

  12. Effects of Spirulina on Cyclophosphamide-Induced Ovarian Toxicity in Rats: Biochemical and Histomorphometric Evaluation of the Ovary

    PubMed Central

    Yener, Nese Arzu; Sinanoglu, Orhun; Ilter, Erdin; Celik, Aygen; Sezgin, Gulbuz; Midi, Ahmet; Aksungar, Fehime

    2013-01-01

    Cyclophosphamide (Cyc) is known to cause ovotoxicity and infertility in women. Our aim is to investigate the possible ovotoxic effects of Cyc and possible antioxidant and protective effects of blue-green algae, Spirulina (Sp), in rat ovaries. Eighteen rats were given: group I (n = 6, control); group II (n = 6, CP), a single dose Cyc; group III (n = 6, Sp+Cyc), 7 days Sp+single dose Cyc. Tissue malondialdehyde (MDA) levels, superoxide dismutase (SOD), and catalase (CAT) activities are assessed biochemically. Normal and atretic primordial and primary follicle counts for all sections obtained for each ovary are calculated. Mean number of follicle counts for each group are compared. In Sp+Cyc group, tissue MDA levels were significantly lower than those in the CP and higher than those in the C group (CP > Sp+Cyc > C). Tissue SOD activity was significantly higher in Sp+Cyc group than that in the CP group and lower than that in the C group (C > Sp+Cyc > C). No statistically significant difference was found between the ovarian CAT activities in any group. Histomorphometrically, there was also no significant difference between the mean numbers of normal and atretic small follicle counts. Our results suggest that single dose Cyc has adverse effects on oxidant status of the ovaries and Sp has protective effects in Cyc-induced ovotoxicity. PMID:23762559

  13. Histomorphometric analysis of collagen and elastic fibres in the cranial and caudal fold of the porcine glottis.

    PubMed

    Lang, A; Koch, R; Rohn, K; Gasse, H

    2015-06-01

    The porcine glottis differs from the human glottis in its cranial and caudal vocal folds (CraF, CauF). The fibre apparatus of these folds was studied histomorphometrically in adult minipigs. For object definition and quantification, the colour-selection tools of the Adobe-Photoshop program were used. Another key feature was the subdivision of the cross-sections of the folds into proportional subunits. This allowed a statistical analysis irrespective of differences in thickness of the folds. Both folds had a distinct, dense subepithelial layer equivalent to the basement membrane zone in humans. The subsequent, loose layer was interpreted - in principle - as being equivalent to Reinke's space of the human vocal fold. The next two layers were not clearly separated. Due to this, the concept of a true vocal ligament did not appear applicable to neither CauF nor CraF. Instead, the body-cover model was emphasized by our findings. The missing vocalis muscle in the CraF is substituted by large collagen fibre bundles in a proportional depth corresponding to the position of the muscle of the CauF. The distribution of elastic fibres made the CraF rather than the CauF more similar to the human vocal fold. We suggest that these data are useful for those wishing to use the porcine glottis as a model for studying oscillatory properties during phonation. PMID:24995486

  14. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  15. Evaluating synteny for improved comparative studies

    PubMed Central

    Ghiurcuta, Cristina G.; Moret, Bernard M. E.

    2014-01-01

    Motivation: Comparative genomics aims to understand the structure and function of genomes by translating knowledge gained about some genomes to the object of study. Early approaches used pairwise comparisons, but today researchers are attempting to leverage the larger potential of multi-way comparisons. Comparative genomics relies on the structuring of genomes into syntenic blocks: blocks of sequence that exhibit conserved features across the genomes. Syntenic blocs are required for complex computations to scale to the billions of nucleotides present in many genomes; they enable comparisons across broad ranges of genomes because they filter out much of the individual variability; they highlight candidate regions for in-depth studies; and they facilitate whole-genome comparisons through visualization tools. However, the concept of syntenic block remains loosely defined. Tools for the identification of syntenic blocks yield quite different results, thereby preventing a systematic assessment of the next steps in an analysis. Current tools do not include measurable quality objectives and thus cannot be benchmarked against themselves. Comparisons among tools have also been neglected—what few results are given use superficial measures unrelated to quality or consistency. Results: We present a theoretical model as well as an experimental basis for comparing syntenic blocks and thus also for improving or designing tools for the identification of syntenic blocks. We illustrate the application of the model and the measures by applying them to syntenic blocks produced by three different contemporary tools (DRIMM-Synteny, i-ADHoRe and Cyntenator) on a dataset of eight yeast genomes. Our findings highlight the need for a well founded, systematic approach to the decomposition of genomes into syntenic blocks. Our experiments demonstrate widely divergent results among these tools, throwing into question the robustness of the basic approach in comparative genomics. We have taken

  16. [Histomorphometric characteristic of human brain in acute alcoholic intoxication].

    PubMed

    Shormanov, S V; Shormanova, N S

    2005-01-01

    Different brain sections were studied in 20 subjects, who died of ethanol intoxication and in 14 subjects who died of injuries of the heart and main vessels, in order to detect histological changes in the brain and for the purpose of defining spatial and quantitative ratios between cerebral tissue structures in alcoholic intoxication. Different histological, stereometric and morphometric tools were made use of. It was demonstrated that, in alcoholic intoxication, there occur severe disorders of the circulation with affection of vessels in the brain; there are also dystrophic and necrotic changes in neurocytes, glial cells and white substance. The square of neurons shrinks due to death of some of them in the cortex of hemispheres, thalamus and cerebellum. As for the medulla, they are more resistant, there, to ethanol. The diameter of capillaries in the studied brain sections diminishes due to a reduced tonus of cerebral arteries; the quantity of such vessels increases within a standard area, which is conditioned by the compensatory opening of reserve capillaries. All this can be important in dealing with issues of thanatogenesis and of forensic medical diagnosis in death of alcoholic intoxication. PMID:15881135

  17. Doxofylline and Theophylline: A Comparative Clinical Study

    PubMed Central

    Akram, MD Faiz; Nasiruddin, Mohammad; Ahmad, Zuber; Ali Khan, Rahat

    2012-01-01

    Objectives COPD is one of the major public health problems worldwide. Theophylline has been used in the treatment of COPD for decades. Doxofylline a new theophylline congener has been claimed to have better safety profile. The study was undertaken to compare theophylline and doxophylline at doses recommended and commonly used in clinical practice. Methods The study was conducted in patients of COPD in TB chest department of a medical college hospital. It was randomized, prospective and open label. A total of 154 patients were divided in two group .Group I was administered 400 mg theophylline SR once daily and group II was administered doxofylline 400 mg twice a day orally. Spirometric variables symptom score, and adverse effects were recorded on day 0, 7 and 21 of therapy. Data were compared and analysed using SPSS version 16. Results Results of the study showed that there was no statistically significant difference with respect to spirometric variables and symptom score in the two groups and there was no significant difference in two groups with respect to side effects (p>0.05). Conclusions It is concluded that doxophylline has no advantage over theophylline in terms of either efficacy or safety on the doses commonly used in current clinical practice. PMID:23373027

  18. Comparative study of INPIStron and spark gap

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Lee, Ja H.

    1993-01-01

    An inverse pinch plasma switch, INPIStron, was studied in comparison to a conventional spark gap. The INPIStron is under development for high power switching applications. The INPIStron has an inverse pinch dynamics, opposed to Z-pinch dynamics in the spark gap. The electrical, plasma dynamics and radiative properties of the closing plasmas have been studied. Recently the high-voltage pulse transfer capabilities or both the INPIStron and the spark gap were also compared. The INPIStron with a low impedance Z = 9 ohms transfers 87 percent of an input pulse with a halfwidth of 2 mu s. For the same input pulse the spark gap of Z = 100 ohms transfers 68 percent. Fast framing and streak photography, taken with an TRW image converter camera, was used to observe the discharge uniformity and closing plasma speed in both switches. In order to assess the effects of closing plasmas on erosion of electrode material, emission spectra of two switches were studied with a spectrometer-optical multi channel analyzer (OMA) system. The typical emission spectra of the closing plasmas in the INPIStron and the spark gap showed that there were comparatively weak carbon line emission in 658.7 nm and copper (electrode material) line emissions in the INPIStron, indicating low erosion of materials in the INPIStron.

  19. EFQPSK Versus CERN: A Comparative Study

    NASA Technical Reports Server (NTRS)

    Borah, Deva K.; Horan, Stephen

    2001-01-01

    This report presents a comparative study on Enhanced Feher's Quadrature Phase Shift Keying (EFQPSK) and Constrained Envelope Root Nyquist (CERN) techniques. These two techniques have been developed in recent times to provide high spectral and power efficiencies under nonlinear amplifier environment. The purpose of this study is to gain insights into these techniques and to help system planners and designers with an appropriate set of guidelines for using these techniques. The comparative study presented in this report relies on effective simulation models and procedures. Therefore, a significant part of this report is devoted to understanding the mathematical and simulation models of the techniques and their set-up procedures. In particular, mathematical models of EFQPSK and CERN, effects of the sampling rate in discrete time signal representation, and modeling of nonlinear amplifiers and predistorters have been considered in detail. The results of this study show that both EFQPSK and CERN signals provide spectrally efficient communications compared to filtered conventional linear modulation techniques when a nonlinear power amplifier is used. However, there are important differences. The spectral efficiency of CERN signals, with a small amount of input backoff, is significantly better than that of EFQPSK signals if the nonlinear amplifier is an ideal clipper. However, to achieve such spectral efficiencies with a practical nonlinear amplifier, CERN processing requires a predistorter which effectively translates the amplifier's characteristics close to those of an ideal clipper. Thus, the spectral performance of CERN signals strongly depends on the predistorter. EFQPSK signals, on the other hand, do not need such predistorters since their spectra are almost unaffected by the nonlinear amplifier, Ibis report discusses several receiver structures for EFQPSK signals. It is observed that optimal receiver structures can be realized for both coded and uncoded EFQPSK

  20. A Comparative Study of Mammalian Diversification Pattern

    PubMed Central

    Yu, Wenhua; Xu, Junxiao; Wu, Yi; Yang, Guang

    2012-01-01

    Although mammals have long been regarded as a successful radiation, the diversification pattern among the clades is still poorly known. Higher-level phylogenies are conflicting and comprehensive comparative analyses are still lacking. Using a recently published supermatrix encompassing nearly all extant mammalian families and a novel comparative likelihood approach (MEDUSA), the diversification pattern of mammalian groups was examined. Both order- and family-level phylogenetic analyses revealed the rapid radiation of Boreoeutheria and Euaustralidelphia in the early mammalian history. The observation of a diversification burst within Boreoeutheria at approximately 100 My supports the Long Fuse model in elucidating placental diversification progress, and the rapid radiation of Euaustralidelphia suggests an important role of biogeographic dispersal events in triggering early Australian marsupial rapid radiation. Diversification analyses based on family-level diversity tree revealed seven additional clades with exceptional diversification rate shifts, six of which represent accelerations in net diversification rate as compared to the background pattern. The shifts gave origin to the clades Muridae+Cricetidae, Bovidae+Moschidae+Cervidae, Simiiformes, Echimyidae, Odontoceti (excluding Physeteridae+Kogiidae+Platanistidae), Macropodidae, and Vespertilionidae. Moderate to high extinction rates from background and boreoeutherian diversification patterns indicate the important role of turnovers in shaping the heterogeneous taxonomic richness observed among extant mammalian groups. Furthermore, the present results emphasize the key role of extinction on erasing unusual diversification signals, and suggest that further studies are needed to clarify the historical radiation of some mammalian groups for which MEDUSA did not detect exceptional diversification rates. PMID:22457604

  1. Comparative Study of Vented vs. Unvented Crawlspaces

    SciTech Connect

    Biswas, Kaushik; Christian, Jeffrey E; Gehl, Anthony C

    2011-10-01

    There has been a significant amount of research in the area of building energy efficiency and durability. However, well-documented quantitative information on the impact of crawlspaces on the performance of residential structures is lacking. The objective of this study was to evaluate and compare the effects of two crawlspace strategies on the whole-house performance of a pair of houses in a mixed humid climate. These houses were built with advanced envelope systems to provide energy savings of 50% or more compared to traditional 2010 new construction. One crawlspace contains insulated walls and is sealed and semi-conditioned. The other is a traditional vented crawlspace with insulation in the crawlspace ceiling. The vented (traditional) crawlspace contains fiberglass batts installed in the floor chase cavities above the crawl, while the sealed and insulated crawlspace contains foil-faced polyisocyanurate foam insulation on the interior side of the masonry walls. Various sensors to measure temperatures, heat flux through crawlspace walls and ceiling, and relative humidity were installed in the two crawlspaces. Data from these sensors have been analyzed to compare the performance of the two crawlspace designs. The analysis results indicated that the sealed and insulated crawlspace design is better than the traditional vented crawlspace in the mixed humid climate.

  2. Bone histomorphometric analysis in a patient with anorexia nervosa.

    PubMed

    Hiramatsu, Rikako; Ubara, Yoshifumi; Suwabe, Tatsuya; Hoshino, Junichi; Sumida, Keiichi; Hasegawa, Eiko; Yamanouchi, Masayuki; Hayami, Noriko; Sawa, Naoki; Takaichi, Kenmei

    2013-09-01

    A 34-year-old Japanese woman with anorexia nervosa (AN) of a body mass index (BMI) of 11.0 kg/cm(2) was admitted to our hospital for assessment of renal dysfunction with a serum creatinine of 1.8 mg/dL and hypokalemia (3.0 mEq/L). Renal biopsy showed chronic interstitial fibrosis with hypertrophy of the juxtaglomerular apparatus. Iliac crest biopsy was performed because of a severe decrease in bone mineral density. It showed active resorption at the periosteal and endosteal surfaces of cortical bone by numerous osteoclasts, as well as bone island formation in cancellous bone due to marked decrease of trabecular connections. A dynamic study using double labeling showed that mineralization of cancellous bone adjacent to cortical bone occurred between the first and second labelings, but did not occur between the second labeling and osteoid formation during the 28-day period before biopsy, which implied that the mineralization was related to promotion of food intake after hospitalization, while the lack of mineralization was due to poor food intake outside hospital. Empty lacunae that indicated the death of osteocytes were seen. Because her bone mass and kidney injury improved after weight gain and normokalemia were achieved by a highly nutritious diet, malnutrition with hypokalemia may have a negative influence on bone formation due to impaired mineralization and may activate bone resorption by osteoclasts secondary to the formation of empty lacunae. This is the first report about the histological features of premenopausal osteoporosis in a patient with AN and kidney injury. PMID:23726962

  3. Comparative study of heart sound localization algorithms

    NASA Astrophysics Data System (ADS)

    Moukadem, A.; Dieterlen, A.; Hueber, N.; Brandt, C.; Raymond, P.

    2011-05-01

    The purpose of this document is to present a comparative study of five algorithms of heart sound localization, one of which, is a method based on radial basis function networks applied in a novel approach. The advantages and disadvantages of each method are evaluated according to a data base of 50 subjects in which there are 25 healthy subjects selected from the University Hospital of Strasbourg (HUS) and from theMARS500 project (Moscow) and 25 subjects with cardiac pathologies selected from the HUS. This study is made under the control of an experienced cardiologist. The performance of each method is evaluated by calculating the area under a receiver operating curve (AUC) and the robustness is shown against different levels of additive white Gaussian noise.

  4. Pairing Fluctuations Above Tc: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Verga, Simona; Gooding, Robert J.; Marsiglio, Frank

    2003-03-01

    Although the investigation of superconductivity in High Tc Cuprates has been extensive, its microscopic origin is still under debate. An important experimental fact is the universality of many properties of the cuprates (the low dimensionality, the d-wave symmetry of the superconducting gap and the pseudogap), which must be reproduced by any competitive theory. While there is no consensus about the 'glue' that binds two electrons in a pair, one can gain insight by simply providing it, without questioning its nature. The Attractive Hubbard Model for electrons on a lattice provides the means for such an approach, but even if it simplifies the picture considerably, in the coupling regime of interest one needs to rely on approximate theories. We present a comparative study of different versions of the T-matrix approximation in the atomic limit (strong coupling), where the existence of analytical solutions enables us to test how well the approximations work. We also employ a non-perturbative approach due to Y. M. Vilk and A.-M. S. Tremblay and compare it with the T-matrix and the analytical solutions. We discuss the relevance of such a study for other coupling regimes and more realistic models.

  5. Scatterometry or imaging overlay: a comparative study

    NASA Astrophysics Data System (ADS)

    Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

    2015-03-01

    Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

  6. A comparative study on monitored anesthesia care

    PubMed Central

    Sen, Jayashree; Sen, Bitan

    2014-01-01

    Aim: The aim of this study is to compare the effectiveness, hemodynamic changes and duration of sedation and analgesia between combinations of fortwin-phenergan-midazolam (FPM) and ketamine - midazolam (KM) along with local anesthesia for the surgeries done under the umbrella of monitored anesthesia care. Materials and Methods: A total of 50 patients undergoing surgeries as tympanoplasty, septoplasty, lip repair, dacrocystectomy and cataract under local anesthesia, randomly received either intravenous (IV) fortwin 0.3 mg/kg over 1 min followed by IV midazolam 0.04 mg/kg plus IV phenergan 12.5 mg (Group FPM) or IV ketamine 0.3 mg/kg over 1 min plus IV midazolam 0.04 mg/kg (Group KM). Sedation was titrated to Ramsay sedation score (RSS) of 3. Patients’ mean arterial pressure (MAP), heart rate (HR), saturation peripheral pulse, duration of sedation and need for intraoperative rescue sedation/analgesic were recorded and compared. Satisfaction of patients (using a 1-7 point Likert verbal rating scale) and readiness for discharge towards (time to Aldrete score of 10) were also determined. Result: Group KM had significant rise in HR (20-25%) and MAP (25-30%) from 30 min after the bolus dose given until the end of the surgery in contrast to Group FPM. The target sedation level (RSS ≥ 3) was higher in Group FPM (n = 23 [92%]) as compared with Group KM (n = 12 [48%]). Time until need for rescue sedation was 66.96 ± 17.19 min in FPM and 32.80 ± 8.90 min in KM group. The patient satisfaction (Likert scale) is more with the FPM group (6.12 ± 0.83 vs. 4.40 ± 1.20). Conclusion: We found that the combination of FPM is superior to the KM combination as per the hemodynamic changes, duration of analgesia, patients’ satisfaction and efficacy of the drugs are concerned. PMID:25886327

  7. Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats

    PubMed Central

    Bortolin, Raul Hernandes; da Graça Azevedo Abreu, Bento João; Abbott Galvão Ururahy, Marcela; Costa de Souza, Karla Simone; Bezerra, João Felipe; Bezerra Loureiro, Melina; da Silva, Flávio Santos; Marques, Dáfiny Emanuele da Silva; Batista, Angélica Amanda de Sousa; Oliveira, Gisele; Luchessi, André Ducati; Lima, Valéria Morgiana Gualberto Duarte Moreira; Miranda, Carlos Eduardo Saraiva; Lia Fook, Marcus Vinicius; Almeida, Maria das Graças; de Rezende, Luciana Augusto; de Rezende, Adriana Augusto

    2015-01-01

    Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young’s modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective

  8. Water Ice in Comets: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Protopapa, Silvia; Sunshine, J.; Feaga, L. M.; Kelley, M. S.; A'Hearn, M. F.; Farnham, T.; DIXI Team

    2013-06-01

    Processes involving the sublimation of volatiles dominate cometary activity and drive the release of ancient material from within the nucleus into the coma. As comets are kept cold for most of their history, they contain the least processed primordial materials that accumulated into the giant planets. In addition, comets may have delivered their ices and organics to the primitive Earth. The Deep Impact eXtended Investigation (DIXI) to comet Hartley 2 revealed a highly active comet with bright icy-rich jets. We present a detailed characterization of the composition and texture of the ices and refractories in the inner-most coma of Hartley 2, closer than a few kilometers from the surface. This analysis is conducted using laboratory measurements of optical constants of cometary analog materials. We also discuss the implications of these findings on the accretion process that led to the formation of cometary nuclei and therefore of planets. The physical makeup of the ice grains in comet Hartley 2 is compared with that of water ice in the interior, surface, and coma of other comets (e.g., 9P/Tempel 1, C/2002 T7 (LINEAR), 17P/Holmes). Through this comparative study, we investigate how ice is redistributed from the interior to the surface and ultimately into the coma of comets.

  9. Comparative Study of Airfoil Flow Separation Criteria

    NASA Astrophysics Data System (ADS)

    Laws, Nick; Kahouli, Waad; Epps, Brenden

    2015-11-01

    Airfoil flow separation impacts a multitude of applications including turbomachinery, wind turbines, and bio-inspired micro-aerial vehicles. In order to achieve maximum performance, some devices operate near the edge of flow separation, and others use dynamic flow separation advantageously. Numerous criteria exist for predicting the onset of airfoil flow separation. This talk presents a comparative study of a number of such criteria, with emphasis paid to speed and accuracy of the calculations. We evaluate the criteria using a two-dimensional unsteady vortex lattice method, which allows for rapid analysis (on the order of seconds instead of days for a full Navier-Stokes solution) and design of optimal airfoil geometry and kinematics. Furthermore, dynamic analyses permit evaluation of dynamic stall conditions for enhanced lift via leading edge vortex shedding, commonly present in small flapping-wing flyers such as the bumblebee and hummingbird.

  10. Comparative microscopy study of Vibrio cholerae flagella

    NASA Astrophysics Data System (ADS)

    Konnov, Nikolai P.; Baiburin, Vil B.; Zadnova, Svetlana P.; Volkov, Uryi P.

    1999-06-01

    A fine structure of bacteria flagella is an important problem of molecular cell biology. Bacteria flagella are the self-assembled structures that allow to use the flagellum protein in a number of biotechnological applications. However, at present, there is a little information about high resolution scanning probe microscopy study of flagellum structure, in particular, about investigation of Vibrio cholerae flagella. In our lab have been carried out the high resolution comparative investigation of V. cholerae flagella by means of various microscopes: tunneling (STM), scanning force (SFM) and electron transmission. As a scanning probe microscope is used designed in our lab versatile SPM with replaceable measuring heads. Bacteria were grown, fixed and treated according to the conventional techniques. For STM investigations samples were covered with Pt/Ir thin films by rotated vacuum evaporation, in SFM investigations were used uncovered samples. Electron microscopy of the negatively stained bacteria was used as a test procedure.

  11. Supracostal percutaneous nephrolithotomy: A prospective comparative study

    PubMed Central

    Sinha, Maneesh; Krishnappa, Pramod; Subudhi, Santosh Kumar; Krishnamoorthy, Venkatesh

    2016-01-01

    Introduction: A widely prevalent fear of thoracic complications with the supracostal approach has led to its underutilization in percutaneous nephrolithotomy (PCNL). We frequently use the supracostal approach and compared the efficacy and thoracic complications of infracostal, supra 12th, and supra 11th punctures. Materials and Methods: This was a prospective study of patients who underwent PCNL between January 2005 and December 2012. The patients were divided into three groups based on the access: infracostal, supra 12th (between the 11th and 12th ribs) and supra 11th (between the 10th and 11th ribs). Clearance rates, fall in hemoglobin levels, transfusion rates, perioperative analgesic requirements, hospital stay and thoracic complications were compared. Results: Seven hundred patients were included for analysis. There were 179 (25.5%) patients in the supra 11th group, 187 (26.7%) patients in the supra 12th group and 334 (47.8%) patients in the infracostal group. The overall clearance rate was 78% with no difference in the three groups. The postoperative analgesic requirements were significantly higher in the supracostal groups and showed a graded increase from infracostal to supra 12th to supra 11th. During the study period, only 2 patients required angioembolization (0.3%) and none required open exploration. The number of patients requiring intercostal chest drain insertion was extremely low, at 1.6% and 2.2% in the supra 12th and supra 11th groups, respectively. Conclusions: Our results confirm the feasibility of the supracostal approach including punctures above the 11th rib, albeit at the cost of an increase in thoracic complications. Staying in the line of the calyx has helped us to minimize the most dreaded complication of bleeding requiring angioembolization. PMID:26941494

  12. Comparative study of pressure-flow parameters.

    PubMed

    Eri, Lars M; Wessel, Nicolai; Tysland, Ole; Berge, Viktor

    2002-01-01

    Methods for quantification of bladder outlet obstruction (BOO) are still controversial. Parameters such as detrusor opening pressure (p(det.open)), maximum detrusor pressure (p(det.max)), minimum voiding pressure (p(det.min.void)), and detrusor pressure at maximum flow rate (P(det.Qmax)) separate obstructed from nonobstructed patients to some extent, but two nomograms, the Abrams-Griffiths nomogram and the linearized passive urethral resistance relation (LinPURR), are more accepted for this purpose, along with the urethral resistance algorithm. In this retrospective, methodologic study, we evaluated the properties of these parameters with regard to test-retest reproducibility and ability to detect a moderate (pharmacologic) and a pronounced (surgical) relief of bladder outlet obstruction. We studied the pressure-flow charts of 42 patients who underwent 24 weeks of androgen suppressive therapy, 42 corresponding patients who received placebo, and 30 patients who had prostate surgery. The patients performed repeat void pressure-flow examinations before and after treatment or placebo. The various parameters were compared. Among the bladder pressure parameters, P(det.Qmax) seemed to have some advantages, supporting the belief that it is the most relevant detrusor pressure parameter to include in nomograms to quantify BOO. In assessment of a large decrease in urethral resistance, such as after TURp, resistance parameters that are based on maximum flow rate as well as detrusor pressure are preferable. PMID:11948710

  13. A comparative study of depot injection techniques.

    PubMed

    Quartermaine, S; Taylor, R

    Depot injections of long-acting neuroleptic drugs, by maintaining a consistent drug regime, together with regular contact with health-care professionals, are an important factor in helping psychiatric patients who live in the community. As these injections are administered over a long period--often for years--it is important that care is taken to minimise discomfort and to reduce the incidence of problems at the injection site. Seepage of even small amounts of the medication will result in an inaccurate dose being absorbed and, owing to the irritant nature of many of these drugs, leakage into subcutaneous tissue and on to the skin surface can cause pain, irritation and lesions. This study was set up to compare two techniques of administering deep intramuscular injections to determine which best fulfilled the criteria of preventing seepage while causing as little discomfort as possible. The two methods used were the Z-track, which is standard practice in the UK, and the air bubble, which is widely taught and used in Canada and the USA. The study showed the air-bubble method to be significantly more effective at controlling seepage than the Z-track. PMID:7644369

  14. Histomorphometric evaluation of intestinal cellular immune responses in pigs immunized with live oral F4ac+ non-enterotoxigenic E. coli vaccine against postweaning colibacillosis

    PubMed Central

    Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Kezić, D.; Popović, M.; Valpotić, H.; Harapin, I.; Pavižić, Ž.; Njari, B.; Valpotić, I.

    2010-01-01

    ileal cell subsets tested were significantly increased (at P<0.5 or lower) in both principal groups (vaccinated or levamisole primed-vaccinated) of pigs, compared to those recorded in the control non-vaccinated pigs. Based on the histomorphometric quantification of porcine intestinal immune cells from the GALT compartments tested, it is possible to differentiate the responses of pigs immunized by an experimental mucosal vaccine from those of non-immunized pigs. PMID:20353911

  15. Periodontal files--a comparative study.

    PubMed

    Pasquini, R; Clark, S M; Baradaran, S; Adams, D F

    1995-12-01

    Periodontal files are used by many dentists for instrumentation of root surfaces as a part of periodontal treatment. The purposes of this study were: 1) to examine, evaluate, and compare several periodontal files in 3 different conditions: new, used, and used/sharpened and 2) to evaluate the efficacy of 5 sharpening devices. The main characteristics observed included: the number, shape, and interval of blades; the active, rake, and lip angles; changes induced by wear; the influence of sharpening; and the type of metal surfaces comprising the blades. There was a wide range of active angles on each individual file, from a high of 75 degrees to a low of 51 degrees. The range of active angles for all blades on all new files was even greater, from a high of 87 degrees to a low of 30 degrees. Wear, observed on some but not all blades, was not extensive and appeared either as abrasion or, occasionally, as fracture of the blade edge. Sharpness scores (5 = sharpest and 1 = dullest) for new file blades were also extremely variable and spanned the full range of values, with a majority of blades scoring 3.5 and below. Attempts to sharpen files with several devices produced inconsistent results. All 5 sharpening devices had significant shortcomings. It was concluded that the extreme ranges both in active angles and in sharpness scores probably have a significant influence on effectiveness of root instrumentation. PMID:8683416

  16. Assays for mammalian tyrosinase: a comparative study

    SciTech Connect

    Jara, J.R.; Solano, F.; Lozano, J.A.

    1988-01-01

    This work describes a comparative study of the tyrosinase activity determined using three methods which are the most extensively employed; two radiometric assays using L-tyrosine as substrate (tyrosine hydroxylase and melanin formation activities) and one spectrophotometric assay using L-dopa (dopa oxidase activity). The three methods were simultaneously employed to measure the activities of the soluble, melanosomal, and microsomal tyrosinase isozymes from Harding-Passey mouse melanoma through their purification processes. The aim of this study was to find any correlation among the tyrosinase activities measured by the three different assays and to determine whether that correlation varied with the isozyme and its degree of purification. The results show that mammalian tyrosinase has a greater turnover number for L-dopa than for L-tyrosine. Thus, enzyme activity, expressed as mumol of substrate transformed per min, is higher in assays using L-dopa as substrate than those using L-tyrosine. Moreover, the percentage of hydroxylated L-tyrosine that is converted into melanin is low and is affected by several factors, apparently decreasing the tyrosinase activity measured by the melanin formation assay. Bearing these considerations in mind, average interassay factors are proposed. Their values are 10 to transform melanin formation into tyrosine hydroxylase activity, 100 to transform tyrosine hydroxylase into dopa oxidase activity, and 1,000 to transform melanin formation into dopa oxidase activity. Variations in these values due to the presence in the tyrosinase preparations of either inhibitors or regulatory factors in melanogenesis independent of tyrosinase are also discussed.

  17. [Histomorphometric analysis of the bones of rats on board the Kosmos 1667 biosatellite].

    PubMed

    Kaplanskiĭ, A S; Durnova, G N; Sakharova, Z F; Il'ina-Kakueva, E I

    1987-01-01

    Bones of the rats flown on Cosmos-1667 were examined histologically and histomorphometrically. It was found that 7-day exposure to weightlessness led to osteoporosis in the spongy matter of proximal metaphyses of tibia and, although to a lesser extent, in the spongiosa of lumbar vertebrae whereas no signs of osteoporosis were seen in the spongy matter of iliac bones. Osteoporosis in the spongy matter of the above bones developed largely due to the inhibition of bone neoformation, which was indicated by a decrease in the number and activity of osteoblasts. Increased bone resorption (as shown by a greater number and activity of osteoclasts) was observed only in the spongy matter of tibial metaphyses. It is emphasized that a reduction of the number of highly active osteoblasts in spongy bones is one of the early signs of inhibition of bone neoformation and development of osteoporosis. PMID:3695333

  18. Comparative Study of Two Automatic Registration Algorithms

    NASA Astrophysics Data System (ADS)

    Grant, D.; Bethel, J.; Crawford, M.

    2013-10-01

    The Iterative Closest Point (ICP) algorithm is prevalent for the automatic fine registration of overlapping pairs of terrestrial laser scanning (TLS) data. This method along with its vast number of variants, obtains the least squares parameters that are necessary to align the TLS data by minimizing some distance metric between the scans. The ICP algorithm uses a "model-data" concept in which the scans obtain differential treatment in the registration process depending on whether they were assigned to be the "model" or "data". For each of the "data" points, corresponding points from the "model" are sought. Another concept of "symmetric correspondence" was proposed in the Point-to-Plane (P2P) algorithm, where both scans are treated equally in the registration process. The P2P method establishes correspondences on both scans and minimizes the point-to-plane distances between the scans by simultaneously considering the stochastic properties of both scans. This paper studies both the ICP and P2P algorithms in terms of their consistency in registration parameters for pairs of TLS data. The question being investigated in this paper is, should scan A be registered to scan B, will the parameters be the same if scan B were registered to scan A? Experiments were conducted with eight pairs of real TLS data which were registered by the two algorithms in the forward (scan A to scan B) and backward (scan B to scan A) modes and the results were compared. The P2P algorithm was found to be more consistent than the ICP algorithm. The differences in registration accuracy between the forward and backward modes were negligible when using the P2P algorithm (mean difference of 0.03 mm). However, the ICP had a mean difference of 4.26 mm. Each scan was also transformed by the forward and backward parameters of the two algorithms and the misclosure computed. The mean misclosure for the P2P algorithm was 0.80 mm while that for the ICP algorithm was 5.39 mm. The conclusion from this study is

  19. The effects of high-fat diet on implant osseointegration: an experimental study

    PubMed Central

    2016-01-01

    Objectives In this study, we investigated whether a high-fat diet (HFD) affected the bone implant connection (BIC) in peri-implant bone. Materials and Methods Four male rabbits were used in this study. Dental implant surgery was introduced into each tibia, and four implants were integrated into each animal. In both the normal diet (ND) group (n=2) and HFD group (n=2), 8 implants were integrated, for a total of 16 integrated implants. The animals continued with their respective diets for 12 weeks post-surgery. Afterward, the rabbits were sacrificed, and the BIC was assessed histomorphometrically. Results Histologic and histomorphometric analyses demonstrated that BIC was not impaired in the HFD group compared to the ND group. Conclusion Within the limitations of this study, we found that HFD did not decrease the BIC in rabbit tibias. PMID:27595085

  20. Histomorphometric Assessment of the Influence of Low-Level Laser Therapy on Peri-Implant Tissue Healing in the Rabbit Mandible

    PubMed Central

    Gomes, Fernando Vacilotto; Mayer, Luciano; de Oliveira, Marília Gerhardt; Baraldi, Carlos Eduardo; Ponzoni, Deise; Puricelli, Edela

    2015-01-01

    Abstract Objective: The purpose of this study was to demonstrate the effect of low-level laser therapy (LLLT) on the peri-implant bone healing process in the rabbit mandible. Background data: LLLT has been shown to accelerate tissue repair and osseointegration of implants placed into the rabbit tibia. However, the beneficial effects of LLLT have never been tested in the rabbit mandible, which would more closely mimic the human situation. Materials and methods: Twenty-four male New Zealand rabbits were randomly divided into four groups of six animals each. All animals had their left mandibular incisors extracted, followed by immediate insertion of a titanium dental implant in the fresh socket. Three groups received LLLT [aluminum-gallium-arsenide (AlGaAs), λ=830nm, 50 mW, continuous wave (CW)] at three different energy densities per treatment session (E-5, 5 J/cm2; E-10, 10 J/cm2; and E-20, 20 J/cm2). Irradiation was performed every 48 h for 13 days, totaling seven sessions. One group received sham treatment (controls). Histological sections were obtained from each of the 24 mandibles dissected, without first decalcifying the specimens, and were stained with hematoxylin and eosin and Picrosirius red for histomorphometric evaluation. Bone-to-implant contact (BIC), bone formation area, and collagen fiber area were assessed by light microscopy. Results: Significant differences were found between group E-20 and all other groups (p<0.05). Histomorphometric evaluation showed significantly higher BIC and significantly more collagen fibers in group E-20. Conclusions: Photobiostimulation with LLLT at an energy density of 20 J/cm2 per session had a significant positive effect on new bone formation around dental implants inserted in the rabbit mandible. PMID:25751666

  1. A COMPARATIVE STUDY OF VIDEO TAPE RECORDINGS.

    ERIC Educational Resources Information Center

    WIENS, JACOB H.

    THE COMPARATIVE EFFECTIVENESS OF PRESENTLY AVAILABLE VIDEO TAPE MACHINES IS REPORTED, FOR THE CONVENIENCE OF SCHOOL ADMINISTRATORS PLANNING TO USE SUCH EQUIPMENT IN EDUCATIONAL PROGRAMS. TESTS WERE CONDUCTED AT THE WIENS ELECTRONIC LABORATORIES. MACHINE BRANDS TESTED WERE AMPEX, CONCORD, MACHTRONICS, PRECISION, RCA, SONY, AND WOLLENSAK. A DETAILED…

  2. Flip This Classroom: A Comparative Study

    ERIC Educational Resources Information Center

    Unruh, Tiffany; Peters, Michelle L.; Willis, Jana

    2016-01-01

    The purpose of this research was to compare the beliefs and attitudes of teachers using the flipped versus the traditional class model. Survey and interview data were collected from a matched sample of in-service teachers representing both models from a large suburban southeastern Texas school district. The Attitude Towards Technology Scale, the…

  3. Counseling in Costa Rica: A Comparative Study

    ERIC Educational Resources Information Center

    Collier, Crystal

    2013-01-01

    With one of the world's most comprehensive universal healthcare systems, medical tourism in Costa Rica has increased significantly over the past few decades. American tourists save up to 80% of comparative costs for procedures, from heart surgery to root canal treatment. Although many Costa Rican healthcare professionals receive training in North…

  4. Histomorphometric, physical, and mechanical effects of spaceflight and insulin-like growth factor-I on rat long bones.

    PubMed

    Bateman, T A; Zimmerman, R J; Ayers, R A; Ferguson, V L; Chapes, S K; Simske, S J

    1998-12-01

    Previous experiments have shown that skeletal unloading resulting from exposure to microgravity induces osteopenia in rats. In maturing rats, this is primarily a function of reduced formation, rather than increased resorption. Insulin-like growth factor-I (IGF-I) stimulates bone formation by increasing collagen synthesis by osteoblasts. The ability of IGF-I to prevent osteopenia otherwise caused by spaceflight was investigated in 12 rats flown for 10 days aboard the Space Shuttle, STS-77. The effect IGF-I had on cortical bone metabolism was generally anabolic. For example, humerus periosteal bone formation increased a significant 37.6% for the spaceflight animals treated with IGF-I, whereas the ground controls increased 24.7%. This increase in humeral bone formation at the periosteum is a result of an increased percent mineralizing perimeter (%Min.Pm), rather than mineral apposition rate (MAR), for both spaceflight and ground control rats. However, IGF-I did inhibit humerus endocortical bone formation in both the spaceflight and ground control rats (38.1% and 39.2%, respectively) by limiting MAR. This effect was verified in a separate ground-based study. Similar histomorphometric results for spaceflight and ground control rats suggest that IGF-I effects occur during normal weight bearing and during spaceflight. Microhardness measurements of the newly formed bone indicate that the quality of the bone formed during IGF-I treatment or spaceflight was not adversely altered. Spaceflight did not consistently change the structural (force-deflection) properties of the femur or humerus when tested in three-point bending. IGF-I significantly increased femoral maximum and fracture strength. PMID:9855461

  5. DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

    PubMed Central

    Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

    2006-01-01

    In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other. PMID:19089038

  6. Bacterial contamination control mats: a comparative study.

    PubMed Central

    Meddick, H. M.

    1977-01-01

    The ability of six different types of contamination control mats currently in use at the entrances to theatre suites and other clean areas to remove bacteria-carrying particles from theatre trolley wheeels was compared. Marked differences in the effectiveness of this property were obtained; and all mats showed some disadvantages. Modification of one of the mats has resulted in improved efficiency under working conditions. Images Plate 1 PMID:267665

  7. Comparative transport studies of ``1212'' superconductors

    SciTech Connect

    GAPUD,ALBERT; WU,JUDY; YAN,SHAOLIN; XIE,YI-YUAN; KANG,BYEONGWON; SIEGAL,MICHAEL P.; OVERMYER,DONALD L.

    2000-05-17

    HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} (Hg-1212) thin films were fabricated by exchanging the TI cations in TlBa{sub 2}CaCu{sub 2}O{sub 7-{delta}} (Tl-1212) thin films with Hg cations, causing a 30-K increase in Tc. To determine how this exchange effects such a Tc increase, the irreversibility lines, temperature dependence of critical current density, and temperature dependence of Hall angle of Hg-1212 and T1-1212 thin films were measured and then compared. The results strongly suggest that the Tc shift is caused by a doubling of charge carrier density.

  8. Comparative study of some new EPR dosimeters

    NASA Astrophysics Data System (ADS)

    Alzimami, K. S.; Maghraby, Ahmed M.; Bradley, D. A.

    2014-02-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (WPP) and peak-to-peak signal height (HPP). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic.

  9. COMPARATIVE STUDIES OF HERPETOMONADS AND LEISHMANIAS

    PubMed Central

    Noguchi, Hideyo; Tilden, Evelyn B.

    1926-01-01

    obtained in culture, all the strains grow well on leptospira medium, as well as on blood slants. Growth takes place both at 26°C. and at 37°. The morphology of the organisms is considerably modified by cultivation. This is especially true of the plant flagellates. In the latex they have ribbon-like bodies, often twisted, and comparatively short flagella; the protoplasm is clear, almost hyaline. The flagellates seen in the gut and feces of insects are usually large, slender organisms, with flagella as long as or even longer than the body, which contains numerous volutin granules in the cytoplasm. In cultures under parallel conditions the flagellates from both these sources become shorter and thicker, the plant forms no longer appear flat and ribbon-like, and in general the organisms approach one another in morphological features. Even in the case of the least modified insect flagellates, i.e. those from flies, there is never exact correspondence between the natural and the cultivated forms. The morphological features of the cultivated flagellates vary according to the medium on which the organisms are grown and the age of the culture. The flagellates grown on the surface of blood slants are pyriform, with truncated anterior portion, and short flagellum; in the condensation water, however, the individuals are elongated and have long active flagella. On the leptospira medium the slender active forms with long flagella predominate. In the presence of fermentable carbohydrate, or in medium containing considerable acid, peculiar bifurcated or multifurcated individuals are seen. Similar forms have been seen under natural conditions. Cultures of Leishmania behave in the same way under the conditions described. There is a striking difference in rapidity of growth between the organisms isolated by us and the leishmanias, H. ctenocephali, and T. rotatorium. While the stock cultures of the group first mentioned multiply rapidly at 37°C., growth becoming visible within 24 hours, the

  10. Comparative study of five blood cardioplegia systems.

    PubMed

    Byrne, C J; Bednarski, A J; Beckley, P D

    1994-12-01

    Five blood cardioplegia delivery systems (Gish Straight Shot, Sorin BCD Advanced, Avecor MYOtherm, Baxter-Bentley HE-30, and Baxter-Bentley HE-30 Gold) were evaluated with respect to ease of rapid priming, coefficient of heat exchange, pressure drop, bubble trap capacity, and priming volume. Each system was placed in a roller pump circuit consisting of source and collection reservoirs, cardioplegia solution, and pre-post system pressure and temperature monitoring sites. A trial was performed on four units of each brand by first priming the circuit with 0.9% NaCl at 200 ml/min. Bovine blood (hematocrit 22%) was then introduced simulating use during bypass. Pressure drops across the heat exchanger were measured at flows of 200, 300, and 400 ml/min and at temperatures of 37 degrees, 19 degrees, and 4 degrees C. Coefficient of heat exchange was determined at 300 ml/min flow. Air was infused into the system to quantify the bubble trap capacity of the heat exchanger module. Priming volume of the entire system and of the heat exchanger module were determined by draining each into a graduated cylinder. The Sorin system had significantly less priming volume when compared to all others. The HE-30 units had significantly higher heat exchange coefficients compared to all other systems. Variability was noted in pressure drop at the highest flows and lowest temperatures. PMID:10150681

  11. A Comparative Study of Compression Video Technology.

    ERIC Educational Resources Information Center

    Keller, Chris A.; And Others

    The purpose of this study was to provide an overview of compression devices used to increase the cost effectiveness of teleconferences by reducing satellite bandwidth requirements for the transmission of television pictures and accompanying audio signals. The main body of the report describes the comparison study of compression rates and their…

  12. Comparative results of 327 chemical carcinogenicity studies.

    PubMed Central

    Haseman, J K; Huff, J E; Zeiger, E; McConnell, E E

    1987-01-01

    The National Cancer Institute (NCI) and the National Toxicology Program (NTP) have carried out a number of laboratory animal carcinogenicity studies and presented the results of these experiments in a series of Technical Reports. This paper tabulates the results of the 327 NCI/NTP studies carried out to date on 308 distinct chemicals, and discusses certain issues relevant to the evaluation of carcinogenicity in these experiments. This compilation of results from NCI/NTP carcinogenicity experiments provides a large database that can be used to study structure-activity correlations, interspecies concordance, and associations between laboratory animal carcinogenicity and other toxicological effects. PMID:3691430

  13. A Comparative Study of Landmine Detection Techniques

    NASA Astrophysics Data System (ADS)

    Kasban, H.; Zahran, O.; Elaraby, Sayed M.; El-Kordy, M.; Abd El-Samie, F. E.

    2010-09-01

    Several countries suffer from the existence of millions of buried landmines in their territories. These landmines have indefinite life, and may still cause horrific personal injuries and economic dislocation for decades after a war has finished. Therefore, there is a growing demand by these countries for reliable landmine inspection systems. There are several landmine detection techniques that can be used for this purpose. Each technique is suitable for detection under some conditions depending on the type of the landmine case, the explosive material, and the soil. This paper presents an overview of some of the existing landmine detection techniques. These techniques are briefly described and their merits and drawbacks are highlighted and compared. The purpose of this comparison is to shows the ideal conditions and the challenges for each technique. Furthermore, a comparison between landmine detection techniques from the points of view of cost, complexity, speed, safety, false alarm rate and effect of environmental conditions is presented.

  14. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals: Significantly Reduced Bone Stock in the Metaphyseal and Subcapital Regions of Osteoporotic Individuals.

    PubMed

    Sprecher, Christoph M; Schmidutz, Florian; Helfen, Tobias; Richards, R Geoff; Blauth, Michael; Milz, Stefan

    2015-12-01

    Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred.The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals.The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis.At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side.This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus. PMID:26705200

  15. Toucan and hornbill beaks: a comparative study.

    PubMed

    Seki, Yasuaki; Bodde, Sara G; Meyers, Marc A

    2010-02-01

    The structure and mechanical behavior of Toco Toucan (Ramphastos toco) and Wreathed Hornbill (Rhyticeros undulatus) beaks were compared. The beak of both species is a sandwich-structured composite, having an exterior, or rhamphotheca, consisting of multiple layers of keratin scales and a core composed of a fibrous network of bony closed-cell foam. The rhamphotheca is an arrangement of approximately 50microm diameter, overlapping, keratin tiles. The hornbill rhamphotheca exhibits a surface morphology on the ridged casque that is distinguishable from that observed on the bill proper. Intermediate filaments in the keratin matrix were observed by transmission electron microscopy. The Young's modulus measurements of toucan rhamphotheca indicate isotropy in longitudinal and transverse directions, whereas those of hornbill rhamphotheca may suggest anisotropy. The compressive response of beak foam is governed by brittle crushing behavior. The crushing strength of hornbill foam is six times higher than that of toucan foam. Micro- and nanoindentation hardness values were measured for rhamphotheca and foam trabeculae of toucan and hornbill specimens. The sandwich design of beaks was analyzed using the Karam-Gibson and Dawson-Gibson models. The presence of a cellular core increases the bending resistance (Brazier moment) by a factor of 3-6 while decreasing the compressive strength by only 50%. PMID:19699818

  16. LES versus DNS: A comparative study

    NASA Technical Reports Server (NTRS)

    Shtilman, L.; Chasnov, J. R.

    1992-01-01

    We have performed Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of forced isotropic turbulence at moderate Reynolds numbers. The subgrid scale model used in the LES is based on an eddy viscosity which adjusts instantaneously the energy spectrum of the LES to that of the DNS. The statistics of the large scales of the DNS (filtered DNS field or fDNS) are compared to that of the LES. We present results for the transfer spectra, the skewness and flatness factors of the velocity components, the PDF's of the angle between the vorticity and the eigenvectors of the rate of strain, and that between the vorticity and the vorticity stretching tensor. The above LES statistics are found to be in good agreement with those measured in the fDNS field. We further observe that in all the numerical measurements, the trend was for the LES field to be more gaussian than the fDNS field. Future research on this point is planned.

  17. Comparative study of skew detection algorithms

    NASA Astrophysics Data System (ADS)

    Amin, Adnan; Fischer, Stephen; Parkinson, Anthony F.; Shiu, Ricky

    1996-10-01

    Document image processing has become an increasingly important technology in the automation of office documentation tasks. Automatic document scanners such as text readers and optical character recognition systems are an essential component of systems capable of those tasks. One of the problems in this field is that the document to be read is not always placed correctly on a flat-bed scanner. This means that the document may be skewed on the scanner bed, resulting in a skewed image. This skew has a detrimental effect on document analysis, document understanding, and character segmentation and recognition. Consequently, detecting the skew of a document image and correcting it are important issues in realizing a practical document reader. We describe a new algorithm for skew detection. We then compare the performance and results of this skew detection algorithm to other published methods from O'Gorman, Hinds, Le, Baird, Postl, and Akiyama. Finally, we discuss the theory of skew detection and the different approaches taken to solve the problem of skew in documents. The skew correction algorithm we propose has been shown to be extremely fast, with run times averaging under 0.25 CPU seconds to calculate the angle on a DEC 5000/20 workstation.

  18. Social Studies. Language Arts: Comparative World Religions.

    ERIC Educational Resources Information Center

    Moore, John A.

    The elective (7-9) course in world religions outlined in this guide is designed to fit the quinmester organization of schools. The course is described as a study of world religions, focusing on religion as an institution in society. It includes effects of religion on people, governments, and internal relations. The guide is divided according to:…

  19. Articulation of Quality Teaching: A Comparative Study

    ERIC Educational Resources Information Center

    Sakarneh, Mohammad

    2015-01-01

    The aim of this study is to describe and then contrast the New South Wales Department of Education and Training's model of quality teaching with the Jordanian Ministry of Education's conception of quality teaching, looking particularly at potential differences in interpretation. A content analysis methodology was used. Each perspective has been…

  20. Metacognition and Group Differences: A Comparative Study

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.

    2014-01-01

    In this study, metacognition refers to performing visual analysis and discrimination of real life events and situations in naïve psychology, naïve physics, and naïve biology domains. It is used, along with measuring reaction time, to examine differences in the ability of four groups of students to select appropriate pictures that correspond with…

  1. Children's Friendship Development: A Comparative Study

    ERIC Educational Resources Information Center

    Yu, SeonYeong; Ostrosky, Michaelene M.; Fowler, Susan A.

    2011-01-01

    Establishing friendships is an important developmental goal of early childhood, but little research has addressed ways in which parents support the friendship development of their young children with disabilities. The purpose of this survey study was to explore the support strategies that parents use to facilitate their children's friendships.…

  2. Implicature, Pragmatics, and Documentation: A Comparative Study

    ERIC Educational Resources Information Center

    Wright, David

    2008-01-01

    This study investigates the link between the linguistic principles of implicature and pragmatics and software documentation. When implicatures are created in conversation or text, the listener or reader is required to fill in missing information not overtly stated. This information is usually filled in on the basis of previous knowledge or…

  3. Earthquake correlations and networks: A comparative study

    SciTech Connect

    Krishna Mohan, T. R.; Revathi, P. G.

    2011-04-15

    We quantify the correlation between earthquakes and use the same to extract causally connected earthquake pairs. Our correlation metric is a variation on the one introduced by Baiesi and Paczuski [M. Baiesi and M. Paczuski, Phys. Rev. E 69, 066106 (2004)]. A network of earthquakes is then constructed from the time-ordered catalog and with links between the more correlated ones. A list of recurrences to each of the earthquakes is identified employing correlation thresholds to demarcate the most meaningful ones in each cluster. Data pertaining to three different seismic regions (viz., California, Japan, and the Himalayas) are comparatively analyzed using such a network model. The distribution of recurrence lengths and recurrence times are two of the key features analyzed to draw conclusions about the universal aspects of such a network model. We find that the unimodal feature of recurrence length distribution, which helps to associate typical rupture lengths with different magnitude earthquakes, is robust across the different seismic regions. The out-degree of the networks shows a hub structure rooted on the large magnitude earthquakes. In-degree distribution is seen to be dependent on the density of events in the neighborhood. Power laws, with two regimes having different exponents, are obtained with recurrence time distribution. The first regime confirms the Omori law for aftershocks while the second regime, with a faster falloff for the larger recurrence times, establishes that pure spatial recurrences also follow a power-law distribution. The crossover to the second power-law regime can be taken to be signaling the end of the aftershock regime in an objective fashion.

  4. Comparative Study of Morphometric and Fourier Transform Infrared Spectroscopy Analyses of the Collagen Fibers in the Repair Process of Cutaneous Lesions

    PubMed Central

    Nogueira, Veruska Cronemberger; Raniero, Leandro; Costa, Guilherme Bueno; de Freitas Coelho, Nayana Pinheiro Machado; Miranda, Fernando Cronemberger; Arisawa, Emília Ângela Loschiavo

    2016-01-01

    Objective: Compare the efficacy of light-emitting diode (LED) and therapeutic ultrasound (TUS), combined with a semipermeable dressing (D), at forming collagen in skin lesions by morphometry and Fourier transform infrared spectroscopy (FT-IR). Materials and Methods: Surgical skin wounds (2.5 cm) were created on 84 male Wistar rats divided into four groups (n=21): Group I (Control), Group II (LED), Group III (LED+D), and Group IV (US+D). On days 7, 14, and 21, the tissue samples were removed and divided into two pieces, one was used for histological examination (collagen) and the other for FT-IR. Results: The histomorphometric analysis showed no significant differences among groups for collagen deposition at 7 days. However, at 14 days, more deposition of collagen was noted in the groups LED (p<0.05) and LED+D (p<0.001) than in the control. At 21 days, the groups LED, LED+D, and US+D presented significantly greater deposition of collagen when compared with the control. The FT-IR spectra, at 14 days, LED+D had greater amounts of type I collagen, a better organization of fibers, and greater difference of mean separation between the groups, not observed at 7 and 21 days. Innovation: The histomorphometric and FT-IR analyses suggest that the association of semipermeable dressing to LED therapy and to TUS modulates biological events, increasing fibroblast/collagen response and accelerating dermal maturation. Conclusion: The histomorphometric and FT-IR analyses showed that LED therapy is more efficacious than TUS, when combined with a semipermeable dressing, and induced the collagen production in skin lesions. PMID:26862463

  5. Comparative study of the 2016 DPRK event

    NASA Astrophysics Data System (ADS)

    Kebede, Fekadu; Jonathan, Ezekiel; Graham, Gerhard

    2016-04-01

    Effective monitoring of any violations of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) depends upon the State Parties' ability to determine the nature of the source of the signals recorded by the IMS stations. Analysis by the IDC of the data gives some of the required information but makes no effort to determine the nature of source as specified by the Treaty. On January 6, 2016 the IMS network of stations recorded unusual seismic event from the DPRK. This was the fourth time that such an event from a man-made event was recorded from this area. Past detections of announced nuclear tests were on 9 October 2006, 25 May 2009, and 12 February 2013. There are a few natural earthquakes that have been recorded in this region. This study presents results of an assessment of waveform data and amplitude spectra obtained from seismic events observed at regional and/or local distance ranges, for both natural and man-made events located in the DPRK. The study reveals that the waveform displays of the four man-made events are practically simple and have nearly the same signature, yet they are significantly different to those of the observed natural earthquakes occurring in the region. The similarities of the waveforms obtained from the man-made events are due to the closeness of the epicentres and hence no difference in path effects for the Stations considered. The computed amplitude spectra of the waveform for the man-made and natural events also show differences in their relative amplitudes between the respective Primary and Secondary seismic phases, indicating that their sources are different. The study clearly shows the importance of studying the signature of the recorded seismic waves to determine the nature of the source of the energy, if it is man-made or natural, particularly for regions where records of natural earthquakes exist. Determination of the nature of source of recorded seismic waves is fundamental to CTBT verification. Thus data observed at regional and

  6. Egress of Alphaherpesviruses: Comparative Ultrastructural Study

    PubMed Central

    Granzow, Harald; Klupp, Barbara G.; Fuchs, Walter; Veits, Jutta; Osterrieder, Nikolaus; Mettenleiter, Thomas C.

    2001-01-01

    Egress of four important alphaherpesviruses, equine herpesvirus 1 (EHV-1), herpes simplex virus type 1 (HSV-1), infectious laryngotracheitis virus (ILTV), and pseudorabies virus (PrV), was investigated by electron microscopy of infected cell lines of different origins. In all virus-cell systems analyzed, similar observations were made concerning the different stages of virion morphogenesis. After intranuclear assembly, nucleocapsids bud at the inner leaflet of the nuclear membrane, resulting in enveloped particles in the perinuclear space that contain a sharply bordered rim of tegument and a smooth envelope surface. Egress from the perinuclear cisterna primarily occurs by fusion of the primary envelope with the outer leaflet of the nuclear membrane, which has been visualized for HSV-1 and EHV-1 for the first time. The resulting intracytoplasmic naked nucleocapsids are enveloped at membranes of the trans-Golgi network (TGN), as shown by immunogold labeling with a TGN-specific antiserum. Virions containing their final envelope differ in morphology from particles within the perinuclear cisterna by visible surface projections and a diffuse tegument. Particularly striking was the addition of a large amount of tegument material to ILTV capsids in the cytoplasm. Extracellular virions were morphologically identical to virions within Golgi-derived vesicles, but distinct from virions in the perinuclear space. Studies with gB- and gH-deleted PrV mutants indicated that these two glycoproteins, which are essential for virus entry and direct cell-to-cell spread, are dispensable for egress. Taken together, our studies indicate that the deenvelopment-reenvelopment process of herpesvirus maturation also occurs in EHV-1, HSV-1, and ILTV and that membrane fusion processes occurring during egress are substantially different from those during entry and direct viral cell-to-cell spread. PMID:11264357

  7. A comparative study of AGN feedback algorithms

    NASA Astrophysics Data System (ADS)

    Wurster, J.; Thacker, R. J.

    2013-05-01

    Modelling active galactic nuclei (AGN) feedback in numerical simulations is both technically and theoretically challenging, with numerous approaches having been published in the literature. We present a study of five distinct approaches to modelling AGN feedback within gravitohydrodynamic simulations of major mergers of Milky Way-sized galaxies. To constrain differences to only be between AGN feedback models, all simulations start from the same initial conditions and use the same star formation algorithm. Most AGN feedback algorithms have five key aspects: the black hole accretion rate, energy feedback rate and method, particle accretion algorithm, black hole advection algorithm and black hole merger algorithm. All models follow different accretion histories, and in some cases, accretion rates differ by up to three orders of magnitude at any given time. We consider models with either thermal or kinetic feedback, with the associated energy deposited locally around the black hole. Each feedback algorithm modifies the region around the black hole to different extents, yielding gas densities and temperatures within r ˜ 200 pc that differ by up to six orders of magnitude at any given time. The particle accretion algorithms usually maintain good agreement between the total mass accreted by dot{M} dt and the total mass of gas particles removed from the simulation, although not all algorithms guarantee this to be true. The black hole advection algorithms dampen inappropriate dragging of the black holes by two-body interactions. Advecting the black hole a limited distance based upon local mass distributions has many desirably properties, such as avoiding large artificial jumps and allowing the possibility of the black hole remaining in a gas void. Lastly, two black holes instantly merge when given criteria are met, and we find a range of merger times for different criteria. This is important since the AGN feedback rate changes across the merger in a way that is dependent

  8. Comparative mirror cleaning study: a study on removing particulate contamination

    NASA Astrophysics Data System (ADS)

    Houston, Karrie D.

    2006-08-01

    A mirror cleaning study was conducted to assess the effectiveness of three cleaning methods in their ability to remove particulate contamination from reflective mirror surfaces. Presently, the detergent bath, solvent rinse, and CO II snow cleaning methods are the most commonly used optical cleaning techniques within the optics industry. These techniques are also commonly used by the Optics Branch/Code 551 at Goddard Space Flight Center (GSFC) to remove particulate contamination from optical surfaces. In this experimental study, the above-mentioned cleaning methods were used to clean twelve uncoated silicon wafers, twelve gold coated silicon wafers, and twelve gold coated silicon wafers with a silicon oxide protective coating. CO II snow cleaning had an average removal percentage of 84%, followed by the solvent rinse at 74%, and the detergent bath at 61%. In addition to the average removal percentage, this comparative study was designed to: (1) determine the cleaning ability of each method based on the number and size of removed particles; (2) assess the risk of surface damage for each cleaning procedure; (3) evaluate each cleaning method as a function of its initial "qualitative" contamination level ("fairly clean", "dirty", and "very dirty"). The particulate cleanliness of all wafers was characterized using Image Analysis and Image-Pro Plus 5.0 software. In addition, the experimental design and experimental results were analyzed using JMP/Statistical Analytical Software Version 6.0.

  9. A comparative study of the bone metabolic response to dried plum supplementation and PTH treatment in adult, osteopenic ovariectomized rat.

    PubMed

    Smith, Brenda J; Bu, So Young; Wang, Yan; Rendina, Elizabeth; Lim, Yin F; Marlow, Denver; Clarke, Stephen L; Cullen, Diane M; Lucas, Edralin A

    2014-01-01

    Dried plum has been reported to have potent effects on bone in osteopenic animal models, but the mechanisms through which bone metabolism is altered in vivo remain unclear. To address this issue, a study comparing the metabolic response of dried plum to the anabolic agent, parathyroid hormone (PTH), was undertaken. Six month-old female Sprague Dawley rats (n=84) were sham-operated (SHAM) or ovariectomized (OVX) and maintained on a control diet for 6wks until osteopenia was confirmed. Treatments were initiated consisting of a control diet (AIN-93M) supplemented with dried plum (0, 5, 15 or 25%; w/w) or a positive control group receiving PTH. At the end of 6wks of treatment, whole body and femoral bone mineral density (BMD) were restored by the two higher doses of dried plum to the level of the SHAM group. Trabecular bone volume and cortical thickness were also improved with these two doses of dried plum. Dried plum suppressed the OVX-induced increase in bone turnover as indicated by systemic biomarkers of bone metabolism, N-terminal procollagen type 1 (P1NP) and deoxypyridinoline (DPD). Dynamic bone histomorphometric analysis of the tibial metaphysis revealed that dried plum restored the OVX-induced increase in cancellous bone formation rate (BFR) and mineralizing surface (MS/BS) to the SHAM group, but some doses of dried plum increased endocortical mineral apposition rate (MAR). As expected, PTH significantly increased endocortical MAR and BFR, periosteal BFR, and trabecular MAR and BFR beyond that of the OVX and maintained the accelerated rate of bone resorption associated with OVX. Dried plum up-regulated bone morphogenetic protein 4 (Bmp4) and insulin-like growth factor 1 (Igf1) while down-regulating nuclear factor T cell activator 1 (Nfatc1). These findings demonstrate that in the adult osteopenic OVX animal, the effects of dried plum differ from that of PTH in that dried plum primarily suppressed bone turnover with the exception of the indices of bone

  10. What Do We Compare When We Compare Religions? Philosophical Remarks on the Psychology of Studying Comparative Religion Abroad

    ERIC Educational Resources Information Center

    Irvine, Andrew

    2015-01-01

    The issue of comparison is a vexing one in religious and theological studies, not least for teachers of comparative religion in study abroad settings. We try to make familiar ideas fresh and strange, in settings where students may find it hard not to take "fresh" and "strange" as signs of existential threat. The author explores…

  11. Histopathological, histomorphometrical, and immunohistochemical biomarkers in flounder (Platichthys flesus) from the southern Baltic Sea.

    PubMed

    Dabrowska, Henryka; Ostaszewska, Teresa; Kamaszewski, Maciej; Antoniak, Agnieszka; Napora-Rutkowski, Lukasz; Kopko, Orest; Lang, Thomas; Fricke, Nicolai F; Lehtonen, Kari K

    2012-04-01

    Flounder (Platichthys flesus), collected in late fall of 2009 from four coastal sites in the southern Baltic Sea including the Gulf of Gdańsk (GoG), were investigated for a suite of biomarkers of contaminant effects. The biomarkers included liver histopathologies, which were diagnosed and assessed using commonly applied lesion categories, the size and density of melano-macrophage aggregates (MMAs), expression of proliferating cell nuclear antigen (PCNA) and of cytochrome P450 1A (CYP1A) in liver as well as the size and density of MMAs and density of Perls'-positive cells in the spleen. The prevalence of liver lesions differed among the sites. Most frequently occurring were non-specific and early toxicopathic non-neoplastic lesions. Mean MMA size was in the range of 264-519 μm(2) and 717-2137 μm(2) in liver and spleen, respectively, and density was in the range of 6-13 and 15-26 MMAmm(-2), respectively. Mean density of PCNA-positive hepatocytes was in the range of 300-1281 cellsmm(-2). These histomorphometrical biomarkers correlated positively with the muscle Hg, Σ(7)PCB, and ΣDDT residues and negatively with the indices of general liver condition. They showed significant differences between the sites, which were in line with the spatial prevalence of liver lesions and CYP1A induction. Overall, the biomarker responses were more pronounced in the GoG sites in comparison to those outside the Gulf, which confirms some earlier results and broadens the knowledge of contaminant effects in the Polish coastal zone of the Baltic Sea. PMID:22118815

  12. Analysis of new bone, cartilage, and fibrosis tissue in healing murine allografts using whole slide imaging and a new automated histomorphometric algorithm

    PubMed Central

    Zhang, Longze; Chang, Martin; Beck, Christopher A; Schwarz, Edward M; Boyce, Brendan F

    2016-01-01

    Histomorphometric analysis of histologic sections of normal and diseased bone samples, such as healing allografts and fractures, is widely used in bone research. However, the utility of traditional semi-automated methods is limited because they are labor-intensive and can have high interobserver variability depending upon the parameters being assessed, and primary data cannot be re-analyzed automatically. Automated histomorphometry has long been recognized as a solution for these issues, and recently has become more feasible with the development of digital whole slide imaging and computerized image analysis systems that can interact with digital slides. Here, we describe the development and validation of an automated application (algorithm) using Visiopharm’s image analysis system to quantify newly formed bone, cartilage, and fibrous tissue in healing murine femoral allografts in high-quality digital images of H&E/alcian blue-stained decalcified histologic sections. To validate this algorithm, we compared the results obtained independently using OsteoMeasureTM and Visiopharm image analysis systems. The intraclass correlation coefficient between Visiopharm and OsteoMeasure was very close to one for all tissue elements tested, indicating nearly perfect reproducibility across methods. This new algorithm represents an accurate and labor-efficient method to quantify bone, cartilage, and fibrous tissue in healing mouse allografts. PMID:26816658

  13. The Illiteracy Myth. A Comparative Study of Prisoner Literacy Abilities.

    ERIC Educational Resources Information Center

    Black, Stephen; And Others

    Illiteracy is seen to be a feature of the Australian prisoner population. This belief has remained largely untested. A study compared the literacy abilities of prisoners to those found in the adult general population. Additionally, the study compared male and female prisoner literacy abilities. Assessments were made on a profile of literacy…

  14. [Studies of Student Performance on the Comparative Guidance Placement Program.

    ERIC Educational Resources Information Center

    Reed, M. Douglas

    Data from the College Entrance Examination Board's Comparative Guidance and Placement (CGP) Program were used in these two studies of students at Central Virginia Community College (CVCC). In the first study, 1971 fall quarter performance in specific courses and in all courses was compared to CGP performance. The conclusions indicate that: (1) CGP…

  15. Technology-Enhanced Consultation in Counselling: A Comparative Study

    ERIC Educational Resources Information Center

    Astramovich, Randall L.; Jones, W. Paul; Coker, J. Kelly

    2004-01-01

    Two quasi-experimental studies comparing technology-enhanced counselling consultation were conducted with a sample of 147 students enrolled in an undergraduate counselling and consultation course for elementary and secondary teachers. Study 1 (N = 76) compared the effectiveness of counselling consultation using telephone, text chat, or text chat…

  16. Teacher Training and Multiculturalism: National Studies. Studies in Comparative Education.

    ERIC Educational Resources Information Center

    Gagliardi, Raul, Ed.

    This book presents outcomes of UNESCO (United Nations Educational, Scientific, and Cultural Organization) studies on teacher training in eight countries (Bolivia, the Czech Republic, Jordan, Lebanon, Mauritius, Poland, Senegal, and Tunisia) representing different levels of development and different regions of the world but who are facing a common…

  17. From Comparative Education to Comparative Pedagogy: A Physical Education Case Study

    ERIC Educational Resources Information Center

    Georgakis, Steve; Graham, Jessica

    2016-01-01

    In the last two decades forces of globalization and the rise of and access to information technology have transformed the nature of educational research. Traditional disciplines such as comparative education have not been immune to these transformational impacts. Although one might expect globalization to promote the study of comparative…

  18. [Comparative study on nutmeg, mace and their processed products].

    PubMed

    Jia, T; Wang, Z; Wang, Y; Li, J

    1997-09-01

    The contents of volatile oil, myristicin, safrol and methyleugenol, as well as the composition and content of fatty oil in nutmeg, mace and their processed products were comparatively studied. The composition of volatile oil and the detection of trimyristin were compared by TLC. A scientific basis for the development and application of mace has thus been provided. PMID:11038942

  19. Mobile Learning vs. Traditional Classroom Lessons: A Comparative Study

    ERIC Educational Resources Information Center

    Furió, D.; Juan, M.-C.; Seguí, I.; Vivó, R.

    2015-01-01

    Different methods can be used for learning, and they can be compared in several aspects, especially those related to learning outcomes. In this paper, we present a study in order to compare the learning effectiveness and satisfaction of children using an iPhone game for learning the water cycle vs. the traditional classroom lesson. The iPhone game…

  20. A Comparative Study of Document Retrieval Systems of Nursing Interest.

    ERIC Educational Resources Information Center

    Saba, Virginia Kathleen Joseph

    Intended to provide the nursing community with a comparative analysis of four major computerized document retrieval systems and one manual system providing coverage of the nursing literature, this study compares the indexing vocabulary, database coverage, and retrieval performance of the Educational Resource Information Center (ERIC),…

  1. A Comparative Study of Croatian and Hungarian EFL Students

    ERIC Educational Resources Information Center

    Mihaljevic Djigunovic, Jelena; Nikolov, Marianne; Otto, Istvan

    2008-01-01

    This comparative research aims to provide insights into how Croatian and Hungarian 8th graders' proficiency in English as a foreign language (EFL) compares to one another in relation to organizational macro factors. A total of 717 14-year-old students participated in the study in two neighboring regions and towns of Croatia and Hungary examining…

  2. Comparative Studies in Adult Education--A Review.

    ERIC Educational Resources Information Center

    Charters, Alexander N.

    One of the most important recent developments in comparative adult education (CAE) has been the formation in 1987 of the Committee for Study and Research in Comparative Adult Education (CSRCAE), jointly founded by the International Council of Adult Education and the International Congress of University Adult Education. The Committee continues to…

  3. Assistance to Libraries in Developing Nations: Papers on Comparative Studies.

    ERIC Educational Resources Information Center

    Williamson, William L., Ed.

    The papers presented at a one day workshop on the aspects of comparative librarianship are presented in this volume. The topics discussed are: (1) Methods and Evidence in Comparative Studies; (2) Social Change and Library Development; (3) Library Development in Latin America, a Scalogram; (4) Cross-Cultural Aspects of Assistance to Developing…

  4. Nephrotoxic effect of tetradifon in rats: a biochemical and histomorphometric study.

    PubMed

    Badraoui, Riadh; Ben Nasr, Hmed; Louati, Rim; Ellouze, Feriel; Rebai, Tarek

    2012-09-01

    The effects of subchronic exposure to tetradifon on biochemical related kidney toxicological parameters [creatinine (CRT), urea, and uric acid (UA)] were examined. Oxidative stress in kidney tissue was also assessed by measuring vitamin C (VitC) content and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)]. Tetradifon was administered orally to 12 rats at a cumulative dose of 24.3 mg/kg for 12 weeks. Twelve additional rats, no treated, have served as control. Control and treated animals were sacrificed after 6 or 12 weeks. For each group, kidneys were examined for morphometric changes. Results showed that tetradifon induced significant increases in CRT and urea, and decrease in UA. Morphometrically, while mean glomerular volume decreased percentage of sclerosed glomeruli increased in treated rats. Index of interstitial fibrosis was significantly higher. Moreover, renal antioxidant enzyme (SOD and GPx) activities and VitC content decreased. We concluded that tetradifon possessed nephrotoxic by promoting kidney morphometric and functional damage and depleting renal antioxidant defense system in rats. PMID:21216578

  5. Comparative Mirror Cleaning Study: 'A Study on Removing Particulate Contamination'

    NASA Technical Reports Server (NTRS)

    Houston, Karrie

    2007-01-01

    The cleanliness of optical surfaces is recognized as an industry-wide concern for the performance of optical devices such as mirrors and telescopes, microscopes and lenses, lasers and interferometers, and prisms and optical filters. However, no standard has been established for optical cleaning and there is no standard definition of a 'clean' optical element. This study evaluates the effectiveness of commonly used optical cleaning techniques based on wafer configuration, contamination levels, and the number and size of removed particles. It is concluded that cleaning method and exposure time play a significant factor in obtaining a high removal percentage. The detergent bath and solvent rinse method displayed an increase in effective removal percentage as the contamination exposure increased. Likewise, CO2 snow cleaning showed a relatively consistent cleaning effectiveness. The results can help ensure mission success to flight projects developed for the NASA Origins Program. Advantages and disadvantages of each of the optical cleaning methods are described.

  6. Religious Confession and Symptom Severity: A Prospective Comparative Study.

    PubMed

    Rana, Madiha; Rana, Majeed; Herzberg, Philipp Y; Krause, Christin

    2015-12-01

    Little research has been done on comparing confessions regarding mental health. In the present study, 320 people (78 Buddhists, 77 Catholics, 89 Protestants and 79 Muslims) were compared in terms of their symptom severity. Buddhists and Protestants had lower scores than Catholics and Muslims for obsessive-compulsive behavior and hostility. Muslim group had the highest comparative scores for psychoticism. Buddhists and Protestants had comparatively low scores for paranoid ideation and overall symptom severity, with Catholics and Muslims having high ones. Results reveal that confession should be taken in account in psychological research and diagnosis, since it is explicitly associated with psychological well-being. PMID:25204789

  7. Teacher Leader Human Relations Skills: A Comparative Study

    ERIC Educational Resources Information Center

    Roby, Douglas E.

    2012-01-01

    In this study, 142 graduate school teachers working in schools throughout southwestern Ohio assessed their human relation skills. A human relations survey was used for the study, and results were compared with colleagues assessing the teachers in the study. The survey was developed using a Likert-type scale, and was based on key elements affecting…

  8. Comparative Study of Bio-implantable Acoustic Generator Architectures

    NASA Astrophysics Data System (ADS)

    Christensen, D.; Roundy, S.

    2013-12-01

    This paper is a comparative study of the design spaces of two bio-implantable acoustically excited generator architectures: the thickness-stretch-mode circular piezoelectric plate and the bending-mode unimorph piezoelectric diaphragm. The generators are part of an acoustic power transfer system for implanted sensors and medical devices such as glucose monitors, metabolic monitors, drug delivery systems, etc. Our studies indicate that at small sizes the diaphragm architecture outperforms the plate architecture. This paper will present the results of simulation studies and initial experiments that explore the characteristics of the two architectures and compare their performance.

  9. Entrepreneurial Training: A Comparative Study across Fifteen European Countries

    ERIC Educational Resources Information Center

    Matricano, Diego

    2014-01-01

    This paper arises from the contents of the Lisbon Strategy, a set of cooperation policies stressing the role of education and training. The findings from a comparative study of the influence that entrepreneurial training--classified as formal or informal--can have on start-up expectations are analysed. The study covers fifteen European countries…

  10. Joachim Wach and the Study of Religion: A Comparative Approach.

    ERIC Educational Resources Information Center

    Georgia, Robert T.

    1992-01-01

    Discusses the life and career of Joachim Wach, a proponent of comparative study of religion (CSR). Reports that Wach envisioned "Religionwissenschaft," a unitary science taking a systematic approach to the study of religion using elements of theology, philosophy, and social science. Presents Wach's "basic and eternal" questions on ultimate…

  11. Political Ideology: A Comparative Study of Three Chicano Youth Organizations.

    ERIC Educational Resources Information Center

    Garcia, Richard A.

    The study investigated the political ideology of three Chicano youth groups in El Paso, Texas: Mexican American Youth Association (MAYA), Mexican American Political Association (MAPA), and the Alianza. Purpose of the study was to identify and compare the political ideas and attitudes of the three organizations. Questionnaires were administered to…

  12. Wage Rate Comparability Review Washington State Work Study Program.

    ERIC Educational Resources Information Center

    Washington State Higher Education Coordinating Board, Olympia.

    Washington State's Higher Education Coordinating Board undertook a review of the State Work Study (SWS) program requirements related to the classification and compensation of SWS positions at public colleges and universities. A task force studying wage rate comparability was convened to review statutory directives related to this issue and to…

  13. Sustainability of Social Programs: A Comparative Case Study Analysis

    ERIC Educational Resources Information Center

    Savaya, Riki; Spiro, Shimon; Elran-Barak, Roni

    2008-01-01

    The article reports on the findings of a comparative case study of six projects that operated in Israel between 1980 and 2000. The study findings identify characteristics of the programs, the host organizations, and the social and political environment, which differentiated programs that are sustained from those that are not. The findings reaffirm…

  14. Living With and Learning about Radioactivity: A Comparative Conceptual Study.

    ERIC Educational Resources Information Center

    Alsop, Steve

    2001-01-01

    Documents a quasi-scientific comparative study of two groups of 'recent school leavers' in the UK. Studies non-science university undergraduates and explores whether people living with the immediacy and relevance of higher-than-average levels of radioactivity were more knowledgeable and emotionally detached than a similar group removed from this…

  15. A Comparative Study of Students' Achievement in Botany and Zoology

    ERIC Educational Resources Information Center

    Tamir, P.

    1974-01-01

    A comparative study of student achievement in botany and zoology based on data of 10 studies conducted in 20 countries. Up to age 14, students achieve better in zoology; after age 14, students achieve better in botany. Based on the findings, recommendations are suggested regarding curriculum planning, laboratory work and the need for specific…

  16. Histomorphometric characteristics of immune cells in small intestine of pigs perorally immunized with vaccine candidate F18ac+ nonenterotoxigenic E. coli strain

    PubMed Central

    Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Špoljarić, D.; Popović, M.; Valpotić, H.; Vijtiuk, N.; Pavičić, Ž.; Valpotić, I.

    2009-01-01

    Colidiarrhea and colienterotoxemia caused by F4+ and/or F18+ enterotoxigenic E. coli (ETEC) strains are the most prevalent infections of suckling and weaned pigs. Here we tested the immunogenicity and protective effectiveness of attenuated F18ac+ non-ETEC vaccine candidate strain against challenge infection with F4ac+ ETEC strain by quantitative phenotypic analysis of small intestinal leukocyte subsets in weaned pigs.We also evaluated levamisole as an immune response modifier (IRM) and its adjuvanticity when given in the combination with the experimental vaccine. The pigs were parenterally immunized with either levamisole (at days -2, -1 and 0) or with levamisole and perorally given F18ac+ non-ETEC strain (at day 0), and challenged with F4ac+ ETEC strain 7 days later.At day 13 the pigs were euthanatized and sampled for immunohistological/histomorphometrical analyses. Lymphoid CD3+, CD45RA+, CD45RC+, CD21+, IgA+ and myeloid SWC3+ cell subsets were identified in jejunal and ileal epithelium, lamina propria and Peyer’s patches using the avidin-biotin complex method, and their numbers were determined by computer-assisted histomorphometry. Quantitative immunophenotypic analyses showed that levamisole treated pigs had highly increased numbers of jejunal CD3+, CD45RC+ and SWC3+ cells (p<0.05) as compared to those recorded in nontreated control pigs.In the ileum of these pigs we have recorded that only CD21+ cells were significantly increased (p<0.01). The pigs that were treated with levamisole adjuvanted experimental vaccine had significantly increased numbers of all tested cell subsets in both segments of the small intestine. It was concluded that levamisole adjuvanted F18ac+ non-ETEC vaccine was a requirement for the elicitation of protective gut immunity in this model; nonspecific immunization with levamisole was less effective, but confirmed its potential as an IRM. PMID:22073355

  17. A comparative study between shielded and open coplanar waveguide discontinuities

    NASA Technical Reports Server (NTRS)

    Dib, Nihad I.; Harokopus, W. P., Jr.; Ponchak, G. E.; Katehi, L. P. B.

    1993-01-01

    A comparative study between open and shielded coplanar waveguide (CPW) discontinuities is presented. The space domain integral equation method is used to characterize several discontinuities such as the open-end CPW and CPW series stubs. Two different geometries of CPW series stubs (straight and bent stubs) are compared with respect to resonant frequency and radiation loss. In addition, the encountered radiation loss due to different CPW shunt stubs is evaluated experimentally. The notion of forced radiation simulation is presented, and the results of such a simulation are compared to the actual radiation loss obtained rigorously. It is shown that such a simulation cannot give reliable results concerning radiation loss from printed circuits.

  18. Computational comparative study of microwave probes for plasma density measurement

    NASA Astrophysics Data System (ADS)

    Kim, D. W.; You, S. J.; Kim, J. H.; Chang, H. Y.; Oh, W. Y.

    2016-06-01

    A microwave probe is known to be a suitable method to measure plasma density, even in the processing condition and is widely used in various environments of low-temperature processing plasmas. Various types of microwave probes have been researched and developed to measure the precise plasma density. Extensive research has been conducted to investigate each probes characteristic responding to the plasma parameters (plasma density, electron temperature, pressure, sheath width, and so forth) based on both experiments and simulations. However, a comparative study elucidating the relative characteristics of each probe has not been completed yet, despite the wide applications of the probes in processing plasma. We conduct a comparative study among the microwave probes using the numerical method of three-dimensional finite-difference time-domain simulation. In this study, the microwave probes are compared by investigating the precision of plasma density measurement under a comprehensive range of plasma parameters (plasma density, pressure, and sheath width).

  19. Comparing comparators: a look at control arms in kidney cancer studies over the years.

    PubMed

    Bracarda, S; Porta, C; Sisani, M; Marrocolo, F; Paglino, C; Hamzaj, A; D Buono, S; Sternberg, C N

    2015-01-01

    In the past decade, an increasing number of frequently positive randomised clinical trials have been completed, allowing new consideration of the present therapeutic armamentarium for advanced renal cell carcinoma. These studies were predominantly designed to compare the experimental drugs with 1 of 2 active control arms: interferon alpha-2a or sorafenib. Different from expectations, the final results of some of these studies were not in line with the predictions, and the reasons have not been fully investigated. Consequently, there is a great need for careful analysis of the studies carried out so far, chiefly the role and validity of the control arms. In this regard, the examination of patient baseline characteristics and other factors of potential interest seems fundamental for a correct analysis of the results of these trials and consequent optimal use of the available targeted agents. PMID:25375270

  20. Histological assessment of augmented jaw bone utilizing a new collagen barrier membrane compared to a standard barrier membrane to protect a granular bone substitute material.

    PubMed

    Friedmann, Anton; Strietzel, Frank Peter; Maretzki, Burghard; Pitaru, Sandu; Bernimoulin, Jean-Pierre

    2002-12-01

    Successful bone augmentation requires predictable space maintenance and adequate exclusion of those cells that lack osteogenetic potential from the defect area. Natural bone mineral is considered to be osteoconductive and is used as space maker in combination with membrane barrier techniques. The aim of this study was to compare qualitative histological results achieved by using deproteinized bovine bone mineral (DBBM) as a space maintainer and a new collagen barrier (Ossix, test group) vs. the same bone substitute and the standard e-PTFE membrane (Gore-Tex), control group). Twenty-eight patients were randomly assigned to the test or the control group. Seven months after augmentation procedures, biopsies were obtained at reentry and were analysed histomorphometrically. In all, 14 specimens of group I (test group, Ossix) and 13 specimens of group II (controls, PTFE-membranes) showed close qualitative similarity of their histologies. Histomorphometrically, total mineralized bone area was 42% +/- 18% in group I vs. 39% +/- 15% in group II. The unmineralized tissue area was 44% +/- 15% vs. 46% +/- 12% and the area of DBBM remnants 14% +/- 9% and 15% +/- 12%, respectively. The differences were statistically nonsignificant (Mann-Whitney test). The occurrence of barrier exposure did not interfere with the histological outcome either in the test or in the control group. The new collagen barrier combined with the DBBM provided qualitative bone regeneration comparable to the standard e-PTFE material combined with the same mineral. PMID:12519332

  1. [ADJUVANTED INFLUENZA VACCINES: DATA FROM DIRECT COMPARATIVE STUDIES].

    PubMed

    Chernikova, M I; Vasiliev, Yu M

    2015-01-01

    Vaccines are the cornerstone of influenza control, however available vaccines are subject to certain limitations. Adjuvanted vaccines are a promising approach, however available adjuvants have a suboptimal effectiveness and safety profile. Data from direct comparative trials are necessary for selection of optimal adjuvants among currently available and search for novel safe and effective adjuvants for next generation influenza vaccines. Data from published direct comparative studies of adjuvants for influenza vaccines are summarized, a lack of such studies is noted, especially those using adequate methods and designs and comparing adjuvants of major groups (nature/source and mechanism of action). Several promising approaches of adjuvant research and development could be identified: chitosan-based adjuvants, oil-in-water emulsions and multi-component formulations (depot + immune modulating components). PMID:26829860

  2. Rodents for comparative aging studies: from mice to beavers.

    PubMed

    Gorbunova, Vera; Bozzella, Michael J; Seluanov, Andrei

    2008-09-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  3. A Study Comparing Electronic Mail and Voice Messaging Channels.

    ERIC Educational Resources Information Center

    Gluck, Myke; And Others

    1991-01-01

    Describes a study that explored differences in computer-mediated communication messaging by comparing electronic mail and voice messaging used for giving directions. Highlights include a computational linguistic framework that examines differences between written and oral English, models of direction provision, and hypotheses based on preliminary…

  4. Bullying and the Postgraduate Trainee Teacher: A Comparative Study

    ERIC Educational Resources Information Center

    Sewell, Keira; Cain, Tim; Woodgate-Jones, Alex; Srokosz, Anne

    2009-01-01

    In 2001, Maguire published the findings from a survey of the perceptions and experiences of secondary school trainee teachers of adult-adult bullying. The current paper reports on a study which aimed to compare the incidence and nature of bullying of postgraduate trainees in another English teacher training institution with the experiences of…

  5. Decentralized Management in Prison: A Comparative Case Study.

    ERIC Educational Resources Information Center

    Farmer, J. Forbes

    1994-01-01

    Conducted comparative case study of organizational climates in two prisons Findings from 149 staff members and 442 inmates revealed that flattening organizational structure without decentralizing authority seemed to have negative effects on staff supervisory relations and job satisfaction. Inmates reported better quality of life and more effective…

  6. Efficiency study comparing two helicopter planetary reduction stages

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Handschuh, Robert F.

    1990-01-01

    A study was conducted to compare the efficiency of two helicopter transmission planetary reduction stages. Experimental measurements and analytical predictions were made. The analysis predicted and experiments verified that one planetary stage was a more efficient design due to the type of planet bearing used in the stage. The effects of torque, speed, lubricant type, and lubricant temperature on planetary efficiency are discussed.

  7. Treatment of Conduct Disorders in Childhood: A Comparative Study.

    ERIC Educational Resources Information Center

    Robinson, Elizabeth A.

    Children evidencing conduct disorders comprise the bulk of clinical referrals. Longitudinal studies have found that the prognosis for these children is poor in that the majority exhibit antisocial behavior in adulthood. In order to compare two methods of treatment, relationship-based and contingency management, 53 children (33 boys, 20 girls),…

  8. Comparative Study of Bacterial Growth in Magnet Fields

    NASA Astrophysics Data System (ADS)

    Smith, Derek; Masood, Samina

    It has been shown that magnetic fields affect bacterial growth. A comparative study of growth rates for gram-positive and gram-negative bacteria with different types of magnetic fields is done. Special focus is placed upon growth within liquid media, and the effect of magnetic fields relative to the chosen growth medium is considered.

  9. Comparative Study of Student Support Services of AIOU and UKOU

    ERIC Educational Resources Information Center

    Choudhry, Amtul Hafeez; Gujjar, Aijaz Ahmed; Hafeez, Muhammad Rashid

    2008-01-01

    This paper attempts to compare the availability, quality, similarities and differences of student support services in Allama Iqbal Open University (AIOU) and United Kingdom Open University (UKOU) and also to identify and enlist the deficiencies that AIOU students are facing in the student support services. The study found out that student support…

  10. Research Governance and the Role of Evaluation: A Comparative Study

    ERIC Educational Resources Information Center

    Molas-Gallart, Jordi

    2012-01-01

    Through a comparative study of the United Kingdom and Spain, this article addresses the effect of different research governance structures on the functioning and uses of research evaluation. It distinguishes three main evaluation uses: distributive, improvement, and controlling. Research evaluation in the United Kingdom plays important…

  11. The Syntax of Bilingual Children: A Comparative Study.

    ERIC Educational Resources Information Center

    Van Metre, Patricia D.

    The interview techniques developed by Carol Chomsky were used in a comparative study of the language acquisition of 32 bilingual and monolingual third grade students. After these students were matched for age, socioeconomic status, IQ, family environment (both parents in the home), and reading ability, they were placed in four…

  12. A Comparative Study of the Adjustment of Secondary School Students

    ERIC Educational Resources Information Center

    Devika R.

    2014-01-01

    Education is the ability to meet one's life. How the child adjusts with varying situations determines the success of life. The child's adjustment is determined by a number of factors like Home, Social, Educational and Financial adjustment. The investigator here aims to make a comparative study on the adjustment of secondary school students. The…

  13. It Pays to Compare: An Experimental Study on Computational Estimation

    ERIC Educational Resources Information Center

    Star, Jon R.; Rittle-Johnson, Bethany

    2009-01-01

    Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N = 157) learned about…

  14. Political Responses to Reform: A Comparative Case Study.

    ERIC Educational Resources Information Center

    Noblit, George; And Others

    1991-01-01

    Comparative case studies assessed how the micropolitics of educational reform in two elementary schools affected one southeastern district's effort to professionalize teaching. The results indicate that teachers can use micropolitics to resist reform that, in these cases, legitimated centralization and control, and to heighten their control of…

  15. A Comparative Study of Two Acoustic Measures of Hypernasality

    ERIC Educational Resources Information Center

    Vogel, Adam P.; Ibrahim, Hasherah M.; Reilly, Sheena; Kilpatrick, Nicky

    2009-01-01

    Purpose: This study aimed to compare 2 quantitative acoustic measures of nasality in children with cleft lip and palate (CLP) and healthy controls using formalized perceptual assessment as a guide. Method: Fifty participants (23 children with CLP and 27 age- and gender-matched healthy controls) aged between 4 and 12 years produced a variety of…

  16. Different Underlying Neurocognitive Deficits in Developmental Dyslexia: A Comparative Study

    ERIC Educational Resources Information Center

    Menghini, D.; Finzi, A.; Benassi, M.; Bolzani, R.; Facoetti, A.; Giovagnoli, S.; Ruffino, M.; Vicari, S.

    2010-01-01

    The aim of this study was to investigate the role of several specific neurocognitive functions in developmental dyslexia (DD). The performances of 60 dyslexic children and 65 age-matched normally reading children were compared on tests of phonological abilities, visual processing, selective and sustained attention, implicit learning, and executive…

  17. A Comparative Study of Contract Training in Select Community Colleges.

    ERIC Educational Resources Information Center

    Updike, Katherine May

    In 1991, a study was conducted to compare contract training in selected community colleges providing service to business, industry, and government. A sample of 17 colleges was selected from the League for Innovation Contract Training Professional Network; and phone interviews were conducted with and questionnaires were returned by 16 of the 17…

  18. Louis, Hildegarde, and Mary: A Comparative Study in Infant Bilingualism.

    ERIC Educational Resources Information Center

    Bergman, Coral

    Studies of bilingual infants are in disagreement as to the point at which the child distinguishes two languages in his linguistic environment. In this paper, data from two classic works by linguist-parents on bilingual infants are compared with data collected from the author's own bilingual daughter. Five types of behavior are described which…

  19. Using Comparative Online Media to Study the Iraq War

    ERIC Educational Resources Information Center

    Eaton, Jana Sackman

    2004-01-01

    The war in Iraq and the aftermath are receiving media attention around the globe. A plethora of media reports from many other countries is now available online in English. This article recommends possible approaches to developing comparative media studies and provides URLs to specific sources. The NCSS standards addressed by these lessons include:…

  20. Comparative Analysis, Global Policy Studies and the Human Condition.

    ERIC Educational Resources Information Center

    Bertsch, Gary K.

    This paper examines the role that comparative analysis and global policy studies can play in explaining the human condition in the contemporary world. It investigates economic well-being, one dimension of the human condition, and examines some of the attributes that represent it and some of the forces that affect it in villages, social groupings,…

  1. Introduction to a Comparative Study of Educational Administration.

    ERIC Educational Resources Information Center

    Lynch, Patrick D.

    Comparative educational administration is not yet a recognized field, although a number of works concerning cross-cultural educational literature are directly applicable to such studies. Four themes are apparent in relevant works. Beginning in the 19th century, the earliest works focused on European schools in the hopes America could learn from…

  2. Comparative Studies on Sino-Canadian Higher Education

    ERIC Educational Resources Information Center

    Yang, Hong

    2008-01-01

    Today education is internationalization. Both China and Canada have their own strong merits of higher education. This paper approaches comparative studies on differences of Sino-Canadian higher education from new points, so as to achieve an inspiration to the development of Chinese higher education: preserve relative independence between higher…

  3. Generation 1.5 Written Error Patterns: A Comparative Study

    ERIC Educational Resources Information Center

    Doolan, Stephen M.; Miller, Donald

    2012-01-01

    In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student…

  4. A Comparative Study of Students' Attitudes Toward Education.

    ERIC Educational Resources Information Center

    Quintanar, Rosalinda

    The comparative analysis of students' attitudes included Mexican American, Anglo, and Asian students (from Thailand, Taiwan, and the Philippines). A Likert scale was used to measure all attitudes. All analysis performed utilized cross tabulation and chi square. The attitudes studied were reasons for going to college; concept of an educated person…

  5. TRANSMISSION NETWORK PLANNING METHOD FOR COMPARATIVE STUDIES (JOURNAL VERSION)

    EPA Science Inventory

    An automated transmission network planning method for comparative studies is presented. This method employs logical steps that may closely parallel those taken in practice by the planning engineers. Use is made of a sensitivity matrix to simulate the engineers' experience in sele...

  6. A comparative study of nuclear accident consequences for Hong Kong

    SciTech Connect

    Ching, E.M.K.; Yeung, Mankit Ray )

    1993-02-01

    A two-dimensional dispersion and consequence model called RADIS has been developed and used to perform a site-specific investigation of the consequences and risks for Hong Kong as a result of a potential accident at the Daya Bay Nuclear Power Station. The study uses the 1986 Hong Kong weather and demographic data to determine the accident consequences for Hong Kong. The overall cumulative occurrence frequency distributions of early fatality, early injury, latent cancer, and thyroid nodule are compared with those of WASH-1400 and a United Kingdom Atomic Energy Authority (UKAEA) study. This study is generally consistent with the WASH-1400 results and exhibits less conservatism than the UKAEA study.

  7. Comparative analysis of the space power architecture studies

    NASA Technical Reports Server (NTRS)

    Sovie, Ronald J.

    1988-01-01

    The Strategic Defense Initiative Organization (SDIO) has recently completed the initial phase of Space Power Architecture Studies (SPAS). The initial effort consisted of three major contracted efforts and a comparative analysis performed by the SDIO Independent Evaluation Group (IEG) and the IEG Field Support Team. The purpose of the SPAS effort was to evaluate a wide range of power systems for SDIO applications using a wide range of attributes other than power-system mass and volume. Open cycle, closed cycle, and closed power system/weapon platform concepts were studied. The purpose of this paper is to summarize the salient results of these studies, identify important trends and future study needs.

  8. Relationship between Fibroblast Growth Factor 23 and Biochemical and Bone Histomorphometric Alterations in a Chronic Kidney Disease Rat Model Undergoing Parathyroidectomy

    PubMed Central

    Liao, Hung-Wei; Hung, Peir-Haur; Hsiao, Chih-Yen; Liou, Hung-Hsiang; Lin, Hsin-Shih; Huang, Tsang-Hai; Jou, I-Ming; Tsai, Kuen-Jer

    2015-01-01

    Background Phosphate burden in chronic kidney disease (CKD) leads to elevated serum fibroblast factor-23 (FGF-23) levels, secondary hyperparathyroidism and chronic kidney disease-mineral bone disorder (CKD-MBD). However dissociated hyperphosphatemia and low serum FGF-23 concentrations have been observed in experimentally parathyoridectomized rats. The relationships between serum mineral, hormone, and bone metabolism may be altered in the presence of CKD. The aim of our study was to investigate whether a consistent relationship existed between serum FGF-23 levels, specific serum biochemical markers, and histomorphometric parameters of bone metabolism in a parathyroidectomized CKD animal model. Results Sprague Dawley rats were divided into 3 groups: parathyroidectomy (PTX) and CKD (PTX+CKD, 9 rats), CKD without PTX (CKD, 9 rats), and neither PTX nor CKD (sham-operated control, 8 rats); CKD was induced by partial nephrectomy. At 8 weeks after partial nephrectomy, serum biomarkers were measured. Bone histomorphometries of the distal femoral metaphyseal bone were analyzed. The mean serum FGF-23 levels and mean bone formation rate were the highest in the CKD group and the lowest in the PTX+CKD group. Bone volume parameters increased significantly in the PTX+CKD group. Pearson’s correlation revealed that serum FGF-23 levels associated with those of intact parathyroid hormone, phosphate, collagen type I C-telopeptide, and calcium. Univariate linear regression showed that serum FGF-23 values correlated with bone formation rate, bone volume, and osteoid parameters. Stepwise multivariate regression analysis revealed that circulating FGF-23 values were independently associated with bone volume and thickness (β = -0.737; p < 0.001 and β = -0.526; p = 0.006, respectively). Serum parathyroid hormone levels independently correlated with bone formation rate (β = 0.714; p < 0.001) while collagen type I C-telopeptide levels correlated with osteoid parameter. Conclusion Serum FGF

  9. Comparative study of texture detection and classification algorithms

    NASA Astrophysics Data System (ADS)

    Koltsov, P. P.

    2011-08-01

    A description and results of application of the computer system PETRA (performance evaluation of texture recognition algorithms) are given. This system is designed for the comparative study of texture analysis algorithms; it includes a database of textured images and a collection of software implementations of texture analysis algorithms. The functional capabilities of the system are illustrated using texture classification examples. Test examples are taken from the Brodatz album, MeasTech database, and a set of aerospace images. Results of a comparative evaluation of five well-known texture analysis methods are described—Gabor filters, Laws masks, ring/wedge filters, gray-level cooccurrence matrices (GLCMs), and autoregression image model.

  10. Ergonomic intervention, workplace exercises and musculoskeletal complaints: a comparative study

    PubMed Central

    Mehrparvar, Amir Houshang; Heydari, Mohammad; Mirmohammadi, Seyyed Jalil; Mostaghaci, Mehrdad; Davari, Mohammad Hossein; Taheri, Mahmoud

    2014-01-01

    Background: Musculoskeletal disorders are among the most prevalent occupational disorders in different jobs such as office work. Some interventions such as ergonomic modifications and workplace exercises are introduced as the methods for alleviating these disorders. In this study we compared the effect of ergonomic modifications and workplace exercises on musculoskeletal pain and discomfort in a group of office workers. Methods: In an interventional study on office workers, the effect of two interventions was compared. Ergonomic modification consisted of correcting the arrangement of workstation and changing some equipment; workplace exercises included stretching exercises focusing on neck, shoulders, low back, and hand and wrist. Musculoskeletal complaints were assessed and compared before and after 1 month interventions. Results: The frequency of musculoskeletal complaints was high before the study. Both interventions significantly reduced complaints in a similar manner except for low back pain which was reduced in exercise group more than the other group. Conclusion: In this study we found a beneficial short-term effect for both ergonomic modifications and stretching work-place exercises on reducing musculoskeletal pain in office workers. PMID:25405134

  11. Comparative study of turbulence models in predicting hypersonic inlet flows

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.

    1992-01-01

    A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared very well with the experimental data, and performed better than the Thomas model near the walls.

  12. Comparative study of turbulence models in predicting hypersonic inlet flows

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.

    1992-01-01

    A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared wery well with the experimental data, and performed better than the Thomas model near the walls.

  13. A comparative study of primary and secondary stereotypies.

    PubMed

    Ghosh, Debabrata; Rajan, Prashant V; Erenberg, Gerald

    2013-12-01

    This study compares primary stereotypies (repetitive, self-stimulating, and seemingly nonsensical movements that can occur within typically developing children) and secondary stereotypies (those occurring within autistic or mentally retarded children). Utilizing a retrospective chart review from 1995 to 2010, the current study compares primary and secondary stereotypies by the application of a classification system that organizes the movement by its type (motor only, phonic only, mixed) and complexity. In addition, it investigates other parameters associated with the movements such as duration, frequency, age, functional impairment, and progression. The sample group consisted of 28 primary and 28 secondary cases. Primary stereotypies were predominantly motor, simple, of shorter duration, and of less frequency, whereas secondary stereotypies had more vocalization, complexity, longer durations, and higher frequencies. Moreover, functional impairment due to stereotypies was noted in 3 primary and 7 secondary cases, and worsening of stereotypies was noted in 70% of primary versus 44% of secondary cases. PMID:23143719

  14. Comparative studies of silicon photomultipliers and traditional vacuum photomultiplier tubes

    NASA Astrophysics Data System (ADS)

    Shi, Feng; Lü, Jun-Guang; Lu, Hong; Wang, Huan-Yu; Ma, Yu-Qian; Hu, Tao; Zhou, Li; Cai, Xiao; Sun, Li-Jun; Yu, Bo-Xiang; Fang, Jian; Xie, Yu-Guang; An, Zheng-Hua; Wang, Zhi-Gang; Gao, Min; Li, Xin-Qiao; Xu, Yan-Bing; Wang, Ping; Sun, Xi-Lei; Zhang, Ai-Wu; Xue, Zhen; Liu, Hong-Bang; Wang, Xiao-Dong; Zhao, Xiao-Yun; Zheng, Yang-Heng; Meng, Xiang-Cheng; Wang, Hui

    2011-01-01

    Silicon photomultipliers (SiPMs) are a new generation of semiconductor-based photon counting devices with the merits of low weight, low power consumption and low voltage operation, promising to meet the needs of space particle physics experiments. In this paper, comparative studies of SiPMs and traditional vacuum photomultiplier tubes (PMTs) have been performed regarding the basic properties of dark currents, dark counts and excess noise factors. The intrinsic optical crosstalk effect of SiPMs was evaluated.

  15. A Comparative Study of Heat Transfer in Metallic Materials

    NASA Astrophysics Data System (ADS)

    Pǎucǎ, Adina; Hepuţ, Teodor; Pinca-Bretotean, Camelia; Stoica, Diana

    2011-09-01

    Rolling of metallic materials with heat transfer occurs as a result of interaction between the workpiece and the rolling cylinders incandescent. Heat transferred by diffusion into the cylinders generates variable temperature fields. These fields produce variable temperature thermal stress in each rotation cycle of rolling cylinders. This paper aims at mathematical modeling of variable temperature fields, using Matlab. These diagrams obtained are compared with those obtained following experimental study of the thermal lamination cylinders for 5 states isochronous temperature.

  16. Comparative study of acceleration transducers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Buchczik, Dariusz; Wyżgolik, Roman; Pietraszek, Stanisław

    2006-10-01

    The results of comparative studies of the metrological parameters of acceleration transducers constructed in Institute of Electronics, Silesian University of Technology is presented in this article. The construction of the transducers is based on commercially available monolithic accelerometers and optimized for biomedical applications. The parameters determined during the tests are similar to the parameters of the monolithic accelerometers declared by their manufacturers. It proofs that both the mechanical and the electronic construction of the transducers are correct.

  17. [Comparative study of two dried intradermal BCG vaccines (author's transl)].

    PubMed

    Fillastre, C; Guerin, N; Danusantoso, H; Sardadi, S

    1979-01-01

    Two BCG vaccines prepared from the same strain were studied clinically in Indonesia and in France. The concentration in culturable particles was comparable. Observed differences in the Mantoux results are discussed. The French results, based on use in a temperate climate by a specialized team, on well nourished children, appear better than the Indonesian findings. Further steps should be undertaken to improve results in Indonesia. PMID:539694

  18. Comparative Study of Permeatal Sandwich Tympanoplasty and Postaural Underlay Technique

    PubMed Central

    Nagpure, Prakash Shankarrao; Yadav, Manish; Chavan, Sushil

    2016-01-01

    Introduction Tympanoplasty is the most common operation performed by an Otolaryngologist right from the period of residency. During the last hundred years various modifications in this surgical technique have come up because of continued efforts made by otologists all over the world to achieve the best surgical outcome. Aim To compare the graft take up and complications associated with the Permeatal Sandwich Tympanoplasty performed with the use of Otoendoscope and traditional Postaural Underlay technique of Tympanoplasty from 1st September 2014 to 30th August 2015. Materials and Methods Patients attending the ENT OPD, suffering from Chronic Suppurative Otitis Media (CSOM) were selected on the basis of type of perforation and their workup was done to assess the candidature for tympanoplasty. Results A total of 100 patients were included in the study and the overall graft take was 92.3% in cases of Permeatal Sandwich technique as compared to 64.58% in the case of postaural underlay technique, with a majority of the failures in the large central perforation group rendering a p = 0.021 for patients operated for Large perforations, p = 0.036 for moderate perforations and p = 0.476 for small perforations. The overall p = 0.000649 which is highly significant. On comparing the complications there were only 2 cases in Permeatal Sandwich Technique compared to 25 cases in Postaural Underlay technique rendering a highly significant p-value 0f 0.000000348. There was a difference in hearing improvement with majority of the cases improving to the range of 16-25 dB in Permeatal Sandwich technique compared to 26-45 dB in Postaural Underlay technique. Conclusion Permeatal Sandwich technique produce much better results when compared with Postaural approach in terms of graft take up, complications and hearing improvement. PMID:27190842

  19. Low-level laser therapy (LLLT) reduces inflammatory infiltrate and enhances skeletal muscle repair: Histomorphometric parameters

    NASA Astrophysics Data System (ADS)

    Paiva-Oliveira, E. L.; Lima, N. C.; Silva, P. H.; Sousa, N. T. A.; Barbosa, F. S.; Orsini, M.; Silva, J. G.

    2012-09-01

    Low level laser therapy (LLLT) has been suggested as an effective therapeutics in inflammatory processes modulation and tissue repairing. However, there is a lack of studies that analyze the anti-inflammatory effects of the infrared lasers in muscular skeletal injury. The aim of this study was to investigate the effects of low-level laser therapy 904 nm in the repair process of skeletal muscle tissue. Swiss mice were submitted to cryoinjury and divided in test (LLLT-treated) and control groups. Histological sections were stained with hematoxylin-eosin to assess general morphology and inflammatory influx, and Picrossirus to quantify collagen fibers deposition. Our results showed significant reduction in inflammatory infiltrated in irradiated mice after 4 days of treatment compared to control ( p = 0.01). After 8 days, the irradiated group showed high levels at regenerating myofibers with significant statistically differences in relation at control group ( p < 0.01). Collagen deposition was significantly increased in the final stages of regeneration at test group, when compared with control group ( p = 0.05). Our data suggests that LLLT reduces the inflammatory response in the initial stages of injury and accelerates the process of muscular tissue repair.

  20. Comparative Statistical Study of Some SAP UI Technologies

    NASA Astrophysics Data System (ADS)

    Berdie, Adela; Osaci, Mihaela; Dan Lemle, Ludovic

    2011-09-01

    The goal of this paper is to present a comparative study on some web UI (User Interface) technologies that involve the creation of web applications on the platform SAP Net Weaver AS 7.01 of the integrated SAP (System Application Products) system. The attention will be directed mainly to the ABAP (Advanced Business Application Programing) development environment and to the Web Dynpro (WD) technologies, Floor Plan Manager (FPM) and Web Client UI. Through this study, we make an assesment regarding the decision of choosing a technology for the realisation of a project which consists of a web application.

  1. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  2. Osseointegration and biocompatibility of different metal implants - a comparative experimental investigation in sheep

    PubMed Central

    2012-01-01

    Background In the present study, 4 different metallic implant materials, either partly coated or polished, were tested for their osseointegration and biocompatibility in a pelvic implantation model in sheep. Methods Materials to be evaluated were: Cobalt-Chrome (CC), Cobalt-Chrome/Titanium coating (CCTC), Cobalt-Chrome/Zirconium/Titanium coating (CCZTC), Pure Titanium Standard (PTST), Steel, TAN Standard (TANST) and TAN new finish (TANNEW). Surgery was performed on 7 sheep, with 18 implants per sheep, for a total of 63 implants. After 8 weeks, the specimens were harvested and evaluated macroscopically, radiologically, biomechanically (removal torque), histomorphometrically and histologically. Results Cobalt-Chrome screws showed significantly (p = 0.031) lower removal torque values than pure titanium screws and also a tendency towards lower values compared to the other materials, except for steel. Steel screws showed no significant differences, in comparison to cobalt-chrome and TANST, however also a trend towards lower torque values than the remaining materials. The results of the fluorescence sections agreed with those of the biomechanical test. Histomorphometrically, there were no significant differences of bone area between the groups. The BIC (bone-to-implant-contact), used for the assessment of the osseointegration, was significantly lower for cobalt-chrome, compared to steel (p = 0.001). Steel again showed a lower ratio (p = 0.0001) compared to the other materials. Conclusion This study demonstrated that cobalt-chrome and steel show less osseointegration than the other metals and metal-alloys. However, osseointegration of cobalt-chrome was improved by zirconium and/or titanium based coatings (CCTC, TANST, TAN, TANNEW) being similar as pure titanium in their osseointegrative behavior. PMID:22400715

  3. A comparative study of fluoride release from two different sealants

    PubMed Central

    Ananda, Shimoga-Raju

    2014-01-01

    Objectives: The introduction of fluoride releasing sealants and glass ionomer cements as fissure sealants adds another dimension to prevention of pit and fissure caries. The ability of resin sealants and glass ionomer cements to release fluoride on a long term basis to the sealed enamel and the adjacent unsealed pit and fissure and cuspal incline enamel may allow for further reduction in pit and fissure caries experience for children. Hence, the study was conducted to compare the amount of fluoride release in the plaque after placing fluoride releasing pit and fissure sealants and glass ionomer fissure sealants used in Atraumatic Restorative Treatment (ART) approach. To compare the fluoride release of both the materials at the different time intervals. Material and Methods: A total of 60 school going children were included in this study. Before application of the sealants, baseline plaque fluoride levels were estimated from all the study subjects. After application of sealants again the same was estimated at an interval of 24 hour, 9 days, 2 weeks and 4 weeks. Results: The peak plaque fluoride levels were achieved at 24 hours after application of fissure sealants in all the groups. Conclusions: Within the limitation of the study, the present study indicated that fluoride releasing fissure sealants may act as a source of fluoride in plaque which will help in preventing pit and fissure and smooth surface caries in the tooth sealed with fissure sealants. Key words:Plaque fluoride, pit and fissures sealants, dental caries. PMID:25674315

  4. Comparing protein VEGF inhibitors: In vitro biological studies

    SciTech Connect

    Yu, Lanlan; Liang, Xiao Huan; Ferrara, Napoleone

    2011-05-06

    Highlights: {yields} VEGF is a mediator of angiogenesis. {yields} VEGF inhibitors have clinical applications in cancer and eye disorders. {yields} Five protein VEGF inhibitors were compared for their ability to inhibit. {yields} VEGF-induced activities in cultured endothelial cells. -- Abstract: VEGF inhibitors are widely used as a therapy for tumors and intravascular neovascular disorders, but limited and conflicting data regarding their relative biological potencies are available. The purpose of the study is to compare different protein VEGF inhibitors for their ability to inhibit VEGF-stimulated activities. We tested ranibizumab, the full-length variant of ranibizumab (Mab Y0317), bevacizumab, the VEGF-TrapR1R2 and Flt(1-3)-IgG in bioassays measuring VEGF-stimulated proliferation of bovine retinal microvascular endothelial cells or chemotaxis of human umbilical vein endothelial cells (HUVEC). The inhibitors were also compared for their ability to inhibit MAP kinase activation in HUVECs following VEGF addition. Ranibizumab, VEGF-TrapR1R2 and Flt(1-3)-IgG had very similar potencies in the bioassays tested. Bevacizumab was over 10-fold less potent than these molecules. Mab Y0317 was over 30-fold more potent than bevacizumab. The findings reported in this manuscript describe important intrinsic characteristics of several VEGF inhibitors that may be useful to design and interpret preclinical or clinical studies.

  5. A comparative study of bifidobacteria in human babies and adults.

    PubMed

    Khonsari, Shadi; Suganthy, Mayuran; Burczynska, Beata; Dang, Vu; Choudhury, Manika; Pachenari, Azra

    2016-01-01

    The composition and diversity of the gut microbiota are known to be different between babies and adults. The aim of this project was to compare the level of bifidobacteria between babies and adults and to investigate the influence of lifestyle factors on the level of this bacterium in the gut. During this study, the levels of bifidobacteria in 10 human babies below 2 years of age were compared with that of 10 human adults above 40 years. The level of bifidobacteria proved to be significantly higher in babies in comparison with adults. This investigation concluded that a combination of several factors, such as age, diet, and BMI, has an important effect on the level of bifidobacteria in adults, while in babies, a combination of diet and age may influence the level of intestinal bifidobacteria. PMID:27200263

  6. Comparative studies of industrial grade carbon black powders

    NASA Astrophysics Data System (ADS)

    Chawla, Komal; Chauhan, Alok P. S.

    2016-05-01

    Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375 was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.

  7. A comparative study of bifidobacteria in human babies and adults

    PubMed Central

    KHONSARI, Shadi; SUGANTHY, Mayuran; BURCZYNSKA, Beata; DANG, Vu; CHOUDHURY, Manika; PACHENARI, Azra

    2015-01-01

    The composition and diversity of the gut microbiota are known to be different between babies and adults. The aim of this project was to compare the level of bifidobacteria between babies and adults and to investigate the influence of lifestyle factors on the level of this bacterium in the gut. During this study, the levels of bifidobacteria in 10 human babies below 2 years of age were compared with that of 10 human adults above 40 years. The level of bifidobacteria proved to be significantly higher in babies in comparison with adults. This investigation concluded that a combination of several factors, such as age, diet, and BMI, has an important effect on the level of bifidobacteria in adults, while in babies, a combination of diet and age may influence the level of intestinal bifidobacteria. PMID:27200263

  8. A Comparative Study on Emerging Electric Vehicle Technology Assessments

    SciTech Connect

    Ford, Jonathan; Khowailed, Gannate; Blackburn, Julia; Sikes, Karen

    2011-03-01

    Numerous organizations have published reports in recent years that investigate the ever changing world of electric vehicle (EV) technologies and their potential effects on society. Specifically, projections have been made on greenhouse gas (GHG) emissions associated with these vehicles and how they compare to conventional vehicles or hybrid electric vehicles (HEVs). Similar projections have been made on the volumes of oil that these vehicles can displace by consuming large amounts of grid electricity instead of petroleum-based fuels. Finally, the projected rate that these new vehicle fleets will enter the market varies significantly among organizations. New ideas, technologies, and possibilities are introduced often, and projected values are likely to be refined as industry announcements continue to be made. As a result, over time, a multitude of projections for GHG emissions, oil displacement, and market penetration associated with various EV technologies has resulted in a wide range of possible future outcomes. This leaves the reader with two key questions: (1) Why does such a collective range in projected values exist in these reports? (2) What assumptions have the greatest impact on the outcomes presented in these reports? Since it is impractical for an average reader to review and interpret all the various vehicle technology reports published to date, Sentech Inc. and the Oak Ridge National Laboratory have conducted a comparative study to make these interpretations. The primary objective of this comparative study is to present a snapshot of all major projections made on GHG emissions, oil displacement, or market penetration rates of EV technologies. From the extensive data found in relevant publications, the key assumptions that drive each report's analysis are identified and 'apples-to-apples' comparisons between all major report conclusions are attempted. The general approach that was taken in this comparative study is comprised of six primary steps: (1

  9. Spiritual coping in rehabilitation- a comparative study: part 2.

    PubMed

    Baldacchino, Donia; Torskenaes, Kristina; Kalfoss, Mary; Borg, Josette; Tonna, Aaron; Debattista, Clifford; Decelis, Neville; Mifsud, Rodianne

    Spiritual coping, which may or may not contain religiosity, may enhance adaptation of clients with chronic illness. Part 1 of this article (Baldacchino et al, 2013) presented the research methodology of this cross-sectional comparative study, which explored the spiritual coping of clients with chronic illness receiving rehabilitation services in Malta (n=44) (lower limb amputation: n=10, chronic heart disease: n=9, osteoarthritis in an institution: n=10 and in the community: n=15) and Norway (n=16) (post-hip/shoulder surgery: n=5; chronic heart disease: n=5; chronic pain: n=6). Data were collected from seven purposive samples by focus groups. Roy's adaptation model (1984) and Neuman's Systems Model (2010) guided the study. Part2 discusses the findings, which consist of one main spiritual coping theme and three sub-themes: 'adopting religious coping strategies, relationship with God, and time for reflection and counting one's blessings'. Commonalities were found in the findings except in one dimension, which was found only in the Malta group, that is, being supported by others with a similar condition. This difference may be a result of the environment in the rehabilitation centres, cultural, and geographical differences between the two countries. While considering the limitations of this study, recommendations are proposed to the rehabilitation and education sectors and further trans-cultural comparative longitudinal research with mixed method approach on various clients with acute, chronic and life-threatening illness. PMID:23588017

  10. Comparative study of clinical pulmonary surfactants using atomic force microscopy

    PubMed Central

    Zhang, Hong; Fan, Qihui; Wang, Yi E.; Neal, Charles R.; Zuo, Yi Y.

    2016-01-01

    Clinical pulmonary surfactant is routinely used to treat premature newborns with respiratory distress syndrome, and has shown great potential in alleviating a number of neonatal and adult respiratory diseases. Despite extensive study of chemical composition, surface activity, and clinical performance of various surfactant preparations, a direct comparison of surfactant films is still lacking. In this study, we use atomic force microscopy to characterize and compare four animal-derived clinical surfactants currently used throughout the world, i.e., Survanta, Curosurf, Infasurf and BLES. These modified-natural surfactants are further compared to dipalmitoyl phosphatidylcholine (DPPC), a synthetic model surfactant of DPPC:palmitoyl-oleoyl phosphatidylglycerol (POPG) (7:3), and endogenous bovine natural surfactant. Atomic force microscopy reveals significant differences in the lateral structure and molecular organization of these surfactant preparations. These differences are discussed in terms of DPPC and cholesterol contents. We conclude that all animal-derived clinical surfactants assume a similar structure of multilayers of fluid phospholipids closely attached to an interfacial monolayer enriched in DPPC, at physiologically relevant surface pressures. This study provides the first comprehensive survey of the lateral structure of clinical surfactants at various surface pressures. It may have clinical implications on future application and development of surfactant preparations. PMID:21439262

  11. Discourse Formation in Comparative Education. 4th, Revised Edition. Comparative Studies Series. Volume 10

    ERIC Educational Resources Information Center

    Schriewer, Jurgen, Ed.

    2012-01-01

    New theories and theory-based methodological approaches have found their way into Comparative Education--just as into Comparative Social Science more generally--in increasing number in the recent past. The essays of this volume express and critically discuss quite a range of these positions such as, inter alia, the theory of self-organizing social…

  12. Comparative DFT study of crystalline ammonium perchlorate and ammonium dinitramide.

    PubMed

    Zhu, Weihua; Wei, Tao; Zhu, Wei; Xiao, Heming

    2008-05-22

    The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases. PMID:18396853

  13. Comparative study of minutiae selection algorithms for ISO fingerprint templates

    NASA Astrophysics Data System (ADS)

    Vibert, B.; Charrier, C.; Le Bars, J.-M.; Rosenberger, C.

    2015-03-01

    We address the selection of fingerprint minutiae given a fingerprint ISO template. Minutiae selection plays a very important role when a secure element (i.e. a smart-card) is used. Because of the limited capability of computation and memory, the number of minutiae of a stored reference in the secure element is limited. We propose in this paper a comparative study of 6 minutiae selection methods including 2 methods from the literature and 1 like reference (No Selection). Experimental results on 3 fingerprint databases from the Fingerprint Verification Competition show their relative efficiency in terms of performance and computation time.

  14. Comparative study for better adjuvant with ropivacaine in epidural anesthesia

    PubMed Central

    Soni, Pramila

    2016-01-01

    Background: Better adjuvants for epidural analgesia are still evolving. Dexmedetomidine that is alpha-2 agonist can be used as an adjuvant in epidural analgesia and anesthesia. Aims: The aim of this study was to compare the effect of dexmedetomidine versus clonidine in combination with ropivacaine in epidural anesthesia on intraoperative and postoperative analgesia, to find out the better adjuvant for regional anesthesia. Settings and Design: Randomized control trial. Materials and Methods: Sixty adult patients (18–60 years) with American Society of Anesthesiologists (ASA) 1/ASA 2 grade and undergoing lower abdominal and lower limbs surgeries were included and randomized into three groups of 20 patients each. Group 1 - received ropivacaine with normal saline. Group 2 - received ropivacaine with dexmedetomidine. Group 3 - received ropivacaine with clonidine. Statistical Analysis: Mean and Standard deviation were calculated. All the data were analyzed using analysis of variance and Chi-square test. The value of P< 0.05 was considered significant. Results: All the three groups were comparable with respect to age, sex, and ASA grade. There was statistically significant mean time to reach T10 sensory block level (15.8, 5.7, 9.6 min in Groups 1, 2, and 3, respectively). The maximum duration of analgesia was statistically higher in Group 2 patients (383.7 vs. 365.3 and 280.5 min in Group 3 and Group 1, respectively). The mean time to reach motor block was significantly shorter in Group 2. Side effects were comparable in all groups with statistically insignificant fall in mean arterial pressure and hypotension was noted with Group 2. Conclusion: We concluded that the patients receiving the addition of dexmedetomidine to ropivacaine in epidural anesthesia had a faster onset and longer duration of sensory and motor blockade. Dexmedetomidine in comparison to clonidine had acceptable sedation and hemodynamic stability and minimal dose requirement make very effective adjuvant

  15. Radioactivity of natural and artificial building materials - a comparative study.

    PubMed

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  16. A Comparative Study of Different Deblurring Methods Using Filters

    NASA Astrophysics Data System (ADS)

    Srimani, P. K.; Kavitha, S.

    2011-12-01

    This paper attempts to undertake the study of Restored Gaussian Blurred Images by using four types of techniques of deblurring image viz., Wiener filter, Regularized filter, Lucy Richardson deconvolution algorithm and Blind deconvolution algorithm with an information of the Point Spread Function (PSF) corrupted blurred image. The same is applied to the scanned image of seven months baby in the womb and they are compared with one another, so as to choose the best technique for restored or deblurring image. This paper also attempts to undertake the study of restored blurred image using Regualr Filter(RF) with no information about the Point Spread Function (PSF) by using the same four techniques after executing the guess of the PSF. The number of iterations and the weight threshold of it to choose the best guesses for restored or deblurring image of these techniques are determined.

  17. Teenage pregnancy: a comparative study of the outcome and complications.

    PubMed

    Thekkekkara, Tina; Veenu, J

    2009-01-01

    This study compares the outcome and complications of pregnancy among teenagers with those above 19 years of age. This retrospective study conducted in a maternity hospital in rural Karnataka, under the guidance of the department of community medicine, St Johns National Academy of Health Sciences, Bangalore, included 221 women who delivered between February 2003 and April 2003. The data was tabulated in excel spreadsheet and analysed using epi 6 programme. Anaemia among teenage multigravidae was found to be a significant health problem. There were no statistically significant differences between the gestational age at delivery and the mode of delivery in the different age groups. Teenage pregnancy was not found to be associated with an increased risk for antenatal complications or postnatal complications. There was no increased incidence of low birth weight or congenital anomalies among the babies of teenage mothers. Mortality was not found to be increased both among the teenage mothers as well as their babies. PMID:19588686

  18. Professional navigation: a comparative study of two Canadian models.

    PubMed

    Fillion, Lise; Cook, Sandra; Veillette, Anne-Marie; de Serres, Marie; Aubin, Michèle; Rainville, François; Fitch, Margaret; Doll, Richard

    2012-01-01

    For many cancer control programs, cancer navigation has emerged as a specific strategy to improve access to supportive care and the patients' experience of cancer care. This study contributes to a better understanding of professional navigation by comparing two Canadian models: Quebec's Pivot Nurse in Oncology (PNO) and Nova Scotia's Cancer Patient Navigator (CPN). Qualitative interviews were conducted with professional navigators, patients and family members, front-line staff, physicians and health administrators (interviews: n = 49; focus groups: n = 10). The two models were analyzed using the professional navigation framework (Fillion et al., 2012). Although the models are different, results show that professional navigators in both programs perform similar functions and face similar challenges. This study highlights the complexity and the value of cancer navigation and recommends relevant actions to optimize its management within the health care system. PMID:23362659

  19. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    SciTech Connect

    Not Available

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs.

  20. Visual Encodings of Temporal Uncertainty: A Comparative User Study.

    PubMed

    Gschwandtnei, Theresia; Bögl, Markus; Federico, Paolo; Miksch, Silvia

    2016-01-01

    A number of studies have investigated different ways of visualizing uncertainty. However, in the temporal dimension, it is still an open question how to best represent uncertainty, since the special characteristics of time require special visual encodings and may provoke different interpretations. Thus, we have conducted a comprehensive study comparing alternative visual encodings of intervals with uncertain start and end times: gradient plots, violin plots, accumulated probability plots, error bars, centered error bars, and ambiguation. Our results reveal significant differences in error rates and completion time for these different visualization types and different tasks. We recommend using ambiguation - using a lighter color value to represent uncertain regions - or error bars for judging durations and temporal bounds, and gradient plots - using fading color or transparency - for judging probability values. PMID:26529717

  1. A Comparative Study on Automotive Brake Testing Standards

    NASA Astrophysics Data System (ADS)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  2. Effect of laser phototherapy on human alveolar bone repair: micro tomographic and histomorphometrical analysis

    NASA Astrophysics Data System (ADS)

    Romão, Marcia M. A.; Marques, Márcia M.; Cortes, Arthur R. G.; Horliana, Anna C. R. T.; Moreira, Maria S.; Lascala, Cesar A.

    2015-06-01

    The immediate dental implant placement in the molars region is critical, because of the high amount of bone loss and the discrepancy between the alveolar crest thickness and the dental implant platform. Laser phototherapy (LPT) improves bone repair thus could accelerate the implant placement. Twenty patients were selected for the study. Ten patients were submitted to LPT with GaAlAs diode laser (808nm) during molar extraction, immediately after, 24h, 48h, 72h, 96h and 7 days. The irradiations were applied in contact and punctual mode (100mW, 0.04cm2, 0.75J/cm2, 30s per point, 3J per point). The control group (n=10) received the same treatment; however with the power of the laser off. Forty days later samples of the tissue formed inside the sockets were obtained for further microtomography (microCTs) and histomorphometry analyses. Data were compared by the Student t test, whereas those from the different microCT parameters were compared by the Pearson correlation test (p<0.05). The relative bone volume, as well as area was significantly higher (p<0.001) in the lased than the control group. In the control group there were negative correlations between number and thickness, and between number and separation of trabecula (p<0.01). Between thickness and separation of trabecula the correlation was positive (p<0.01). The laser group showed significant negative correlation between the number and the thickness of trabecula (p<0.01). LPT accelerated bone repair. By the Pearson correlation test it was possible to infer that the lased group presented a more homogeneous trabecular configuration, which would allow earlier dental implant placement.

  3. A comparative Study of Circulation Patterns at Active Lava Lakes

    NASA Astrophysics Data System (ADS)

    Lev, Einat; Oppenheimer, Clive; Spampinato, Letizia; Hernandez, Pedro; Unglert, Kathi

    2016-04-01

    Lava lakes present a rare opportunity to study magma dynamics in a large scaled-up "crucible" and provide a unique natural laboratory to ground-truth dynamic models of magma circulation. The persistence of lava lakes allows for long-term observations of flow dynamics and of lava properties, especially compared to surface lava flows. There are currently five persistent lava lakes in the world: Halemaumau in Kilauea (Hawaii, USA), Erta Ale (Ethiopia), Nyiragongo (Congo), Erebus (Antarctica), and Villarica (Chile). Marum and Benbow craters of Ambrym volcano (Vanuatu) and Masaya (Nicaragua) have often hosted lava lakes as well. We use visible-light and thermal infrared time-lapse and video footage collected at all above lakes (except Villarica, where the lake is difficult to observe), and compare the circulation patterns recorded. We calculate lake surface motion from the footage using the optical flow method (Lev et al., 2012) to produce 2D velocity fields. We mined both the surface temperature field and the surface velocity field for patterns using machine learning techniques such as "self-organizing maps (SOMs)" and "principle component analysis (PCA)". We use automatic detection technique to study the configuration of crustal plates at the lakes' surface. We find striking differences among the lakes, in flow direction, flow speed, frequency of changes in flow direction and speed, location and consistency of upwelling and downwelling, and crustal plate configuration. We relate the differences to lake size, shallow conduit geometry, lava viscosity, crystal and gas content, and crust integrity.

  4. Metabolic syndrome in patients with psoriasis: A comparative study

    PubMed Central

    Lakshmi, Sristi; Nath, Amiya Kumar; Udayashankar, Carounanidy

    2014-01-01

    Background: Psoriasis patients are at increased risk of developing the metabolic syndrome (MS). Proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6 that are increased in the psoriatic plaques are known to contribute to features of MS such as hypertension, dyslipidemia and insulin resistance. Aims: (1) To establish the frequency of MS in patients with psoriasis. (2) To study the risk factors associated with MS in psoriasis. Materials and Methods: A hospital based comparative study was conducted involving 40 adult patients with psoriasis and 40 age- and sex-matched controls. All participants were evaluated for components of MS. Results: Both groups included 31 males and 9 females. The mean age of the cases and controls were 49.95 years and 49.35 years, respectively. Psoriasis patients with MS had a statistically significant higher mean age (56.31 ± 11.36 years) compared with those without MS (46.89 ± 11.51 years). MS was present in 13 out of 40 (32.5%) patients with psoriasis and 12 out of 40 (30%) controls; this difference was not statistically significant. Higher age and female gender correlated with the presence of MS in psoriasis patients. The presence of MS in psoriasis patients was statistically independent of psoriasis area severity index score, body surface area involvement or psoriatic arthropathy. Conclusion: Our results suggest that there is no close correlation between psoriasis and MS in South Indian patients. PMID:24860744

  5. A comparative study of Raman enhancement in capillaries

    NASA Astrophysics Data System (ADS)

    Eftekhari, Fatemeh; Irizar, Juan; Hulbert, Laila; Helmy, Amr S.

    2011-06-01

    This work reports on the comparative studies of Raman enhancement in liquid core waveguides (LCWs). The theoretical considerations that describe Raman enhancement in LCWs is adapted to analyze and compare the performance of hollow core photonic crystal fibers (HCPCFs) to conventional Teflon capillary tubes. The optical losses in both platforms are measured and used to predict their performance for different lengths. The results show that for an optimal waveguide length, two orders of magnitude enhancement in the Raman signal can be achieved for aqueous solutions using HCPCFs. This length, however, cannot be achieved using normal capillary effects. By integrating the interface of the fluidic pump and the HCPCF into a microfluidic chip, we are able to control fluid transport and fill longer lengths of HCPCFs regardless of the viscosity of the sample. The long-term stability and reproducibility of Raman spectra attained through this platform are demonstrated for naphthalenethiol, which is a well-studied organic compound. Using the HCPCF platform, the detection limit of normal Raman scattering in the range of micro-molars has been achieved. In addition to the higher signal-to-noise ratio of the Raman signal from the HCPCF-platform, more Raman modes of naphthalenethiol are revealed using this platform.

  6. Prevalence of Lebanese stroke survivors: A comparative pilot study.

    PubMed

    Lahoud, Nathalie; Salameh, Pascale; Saleh, Nadine; Hosseini, Hassan

    2016-09-01

    Stroke is a leading cause of morbidity and mortality worldwide and its late burden has mainly been attributable to developing countries. Lebanon is one of these countries where epidemiological studies on stroke burden are scarce but necessary. Thus, the present study was conducted to assess the prevalence of stroke survivors among Lebanese inhabitants. A cross-sectional survey was carried out using randomly selected landline phone numbers on all governorates to retrieve data on stroke survivors and their sociodemographic characteristics. Results were then standardized over the Lebanese and the World Health Organization (WHO) world populations. A total of 6963 Lebanese inhabitants were included in the study; among these were 56 stroke survivors. This led to an adjusted stroke prevalence of 0.50% [95% confidence interval (CI)=0.33-0.66%] and a world-standardized prevalence of 0.60% (95% CI=0.42-0.78%). A significantly higher stroke prevalence was found among older age groups and more socioeconomically privileged areas. Overall, the study showed a relatively higher prevalence of stroke in this sample of Lebanese inhabitants when compared to other developing countries. However, larger community-based studies with a clinical assessment of stroke cases are needed to confirm our findings. PMID:26599284

  7. Comparative study of visual pathways in owls (Aves: Strigiformes).

    PubMed

    Gutiérrez-Ibáñez, Cristián; Iwaniuk, Andrew N; Lisney, Thomas J; Wylie, Douglas R

    2013-01-01

    Although they are usually regarded as nocturnal, owls exhibit a wide range of activity patterns, from strictly nocturnal, to crepuscular or cathemeral, to diurnal. Several studies have shown that these differences in the activity pattern are reflected in differences in eye morphology and retinal organization. Despite the evidence that differences in activity pattern among owl species are reflected in the peripheral visual system, there has been no attempt to correlate these differences with changes in the visual regions in the brain. In this study, we compare the relative size of nuclei in the main visual pathways in nine species of owl that exhibit a wide range of activity patterns. We found marked differences in the relative size of all visual structures among the species studied, both in the tectofugal and the thalamofugal pathway, as well in other retinorecipient nuclei, including the nucleus lentiformis mesencephali, the nucleus of the basal optic root and the nucleus geniculatus lateralis, pars ventralis. We show that the barn owl (Tyto alba), a species widely used in the study of the integration of visual and auditory processing, has reduced visual pathways compared to strigid owls. Our results also suggest there could be a trade-off between the relative size of visual pathways and auditory pathways, similar to that reported in mammals. Finally, our results show that although there is no relationship between activity pattern and the relative size of either the tectofugal or the thalamofugal pathway, there is a positive correlation between the relative size of both visual pathways and the relative number of cells in the retinal ganglion layer. PMID:23296024

  8. Comparative study on the biodegradability of morpholinium herbicidal ionic liquids.

    PubMed

    Ławniczak, Łukasz; Materna, Katarzyna; Framski, Grzegorz; Szulc, Alicja; Syguda, Anna

    2015-07-01

    This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trench collecting agricultural runoff stream, agricultural soil and municipal waste repository. The obtained results revealed that resistance to toxicity and biodegradation efficiency of the microbiota increased in the following order: microbiota from the waste repository > microbiota from agricultural soil ≈ microbiota from an agricultural runoff stream > microbiota from garden soil > microbiota from the river sludge. It was observed that the toxicity of HILs increased with the hydrophobicity of the cation, however the influence of the anion was more notable. The highest toxicity was observed when MCPA was used as the anion (EC50 values ranging from 60 to 190 mg L(-1)). The results of ultimate biodegradation tests indicated that only HILs with 2,4-D as the anion were mineralized to some extent, with slightly higher values for HILs with the 4-decyl-4-ethylmorpholinium cation (10-31 %) compared to HILs with the 4,4-didecylmorpholinium cation (9-20 %). Overall, the cations were more susceptible (41-94 %) to primary biodegradation compared to anions (0-61 %). The obtained results suggested that the surface active properties of the studied HILs may influence their toxicity and biodegradability by bacteria in different environmental niches. PMID:26099357

  9. Comparative Study of Algorithms for Automated Generalization of Linear Objects

    NASA Astrophysics Data System (ADS)

    Azimjon, S.; Gupta, P. K.; Sukhmani, R. S. G. S.

    2014-11-01

    Automated generalization, rooted from conventional cartography, has become an increasing concern in both geographic information system (GIS) and mapping fields. All geographic phenomenon and the processes are bound to the scale, as it is impossible for human being to observe the Earth and the processes in it without decreasing its scale. To get optimal results, cartographers and map-making agencies develop set of rules and constraints, however these rules are under consideration and topic for many researches up until recent days. Reducing map generating time and giving objectivity is possible by developing automated map generalization algorithms (McMaster and Shea, 1988). Modification of the scale traditionally is a manual process, which requires knowledge of the expert cartographer, and it depends on the experience of the user, which makes the process very subjective as every user may generate different map with same requirements. However, automating generalization based on the cartographic rules and constrains can give consistent result. Also, developing automated system for map generation is the demand of this rapid changing world. The research that we have conveyed considers only generalization of the roads, as it is one of the indispensable parts of a map. Dehradun city, Uttarakhand state of India was selected as a study area. The study carried out comparative study of the generalization software sets, operations and algorithms available currently, also considers advantages and drawbacks of the existing software used worldwide. Research concludes with the development of road network generalization tool and with the final generalized road map of the study area, which explores the use of open source python programming language and attempts to compare different road network generalization algorithms. Thus, the paper discusses the alternative solutions for automated generalization of linear objects using GIS-technologies. Research made on automated of road network

  10. Alcoholic Steatosis in Different Strains of Rat: A Comparative Study

    PubMed Central

    Bhopale, Kamlesh K.; Kondraganti, Shakuntala; Fernando, Harshica; Boor, Paul J.; Kaphalia, Bhupendra S.; Shakeel Ansari, G. A.

    2016-01-01

    Background Different strains of rats have been used to study alcoholic liver disease (ALD) while the reason for selecting a particular rat strain was not apparent. Purpose The aim of our study was to compare outbred (Wistar) and inbred (Fischer) strains to evaluate pathological, biochemical changes, and gene expression differences associated with ethanol-induced early hepatic steatosis. Study Design Male Wistar and Fischer-344 rats were pair-fed for 6 weeks with or without 5% ethanol in Lieber-DeCarli liquid diet. Livers were analyzed for histological and lipid-related differences. Results Hepatic midzonal steatosis was mainly found in Wistar rats while Fischer rats showed mostly pericentral steatosis. Increased hepatic steatosis in ethanol-fed Wistar rats is supported by increases in lipids with related genes and transcription factors involved in fatty acid and triglyceride synthesis. Conclusion Our data showed that Fischer rats are relatively less prone to ethanol-mediated steatosis with pericentral lipid deposition pattern in the liver which is similar to humans and show no trace level of lipid accumulation in pair-fed controls as observed in Wistar (outbred) strain. Therefore, Fischer rats are better suited for lipid studies in an early development of ALD. PMID:27213081