AMPA receptor inhibition by synaptically released zinc

Ionotropic glutamate AMPA receptors (AMPARs) play a fundamental role in normal function and plasticity of the brain, and they are also involved in many brain disorders. Despite the central role of AMPARs in neurobiology, the modulation of synaptic AMPA responses by endogenous modulators remains not well understood. Here, in three synapses found in two different brain areas, we provide the first evidence, to our knowledge, that endogenous zinc is coreleased with glutamate and modulates the strength of synaptic AMPAR responses. Because in many neocortical areas more than 50% of excitatory presynaptic terminals contain zinc within their glutamatergic vesicles, our findings establish zinc as a general neuromodulator that allows for fine-tuning and plasticity of glutamatergic fast synaptic transmission in the brain.National Institutes of Health (U.S.) (R01-GM065519)National Institutes of Health (U.S.) (F32- DC013734)National Institutes of Health (U.S.) (F32-GM109516)National Institutes of Health (U.S.) (R01-DC007905

Relationships among geomorphological variables affecting water yield from small watersheds

The objectives of this study were (1) to develop numerical expressions for geomorphological parameters affecting water yield which would be compatible with computer analysis, and (2) to determine the minimum number of parameters necessary to relate geomorphological factors to the water yield from small watersheds. Ten watersheds located in four physiographic regions of Tennessee were selected for this study. Four of the watersheds are located near Oak Ridge in the Valley and Ridge physiographic region; two are near Spring Hill in the Central Basin physiographic region; two are near Milan in the Gulf Coastal Plain physiographic region, and two are near Crossville in the Cumberland Plateau region. Seventeen numerical expressions for the selected physiographic parameters were determined from topographic maps. Numerical expressions of soil and land-use were determined from USDA-SCS soil-cover index numbers. Rotated factor analyses were used to find the minimum number of parameters required to represent the original variables. Seven of the seventeen parameters were found to account for most of the information contained in the variables. They were (1) area, (2) form, (3) mean elevation, (4) elevation distribution, (5) total relief, (6) mean slope, and (7) stream order one. In an analysis in which the soil-cover parameter was included, this parameter was shown to be important, but not as pronounced as the others. This might have been due to the fact that the numerical differences were not great among the soil-cover indices for the six watersheds for which the soil-cover index was used. The depth of soil profile was also found to be a factor which should be included

Practice patterns and their influence on prevalence of musculoskeletal disorders among Indian dentists

Background: The term musculoskeletal disorders (MSDs) refers to conditions that involve the nerves, tendons, muscles and supporting structures of the body. Dentists are prone for MSDs especially neck and back pain owing to the following risk factors as a part of their practice – repetitive movements, maintenance of awkward body postures for a long time and tasks that require fine motor skills and close visual focus.Methods: 300 practicing dentists in Bangalore were asked to respond to a questionnaire about their practice pattern (years of practice, hours of work, specialization, two-handed/four handed dentistry, use of magnifications etc), their general lifestyle including exercise and fitness patterns, prevalence of MSDs and their general awareness regarding MSDs. The responses were analyzed using descriptive statistics, univariate analysis and Chi-square tests for independence.Results: In our study 95.16% (n=236) and 90.32% (n=224) respondents reported MSDs in the past and in the previous 12 months of the study respectively. 54.84% (n=136) reported at least one episode of backache, 51.61% (n=128) reported neck pain, 19.35% (n=48) reported pain in the shoulder and 32.25% (n=80) reported pain in the wrist and/or hand in the previous 12 months. Our study found significant influence of the hours of work, use of assistant and magnification on backache, neck pain and wrist/hand pain.Conclusions: Work-related pain being common and multifactorial, any possible solution should also be multifactorial and can be managed or alleviated effectively using a multifaceted approach and the strategies for prevention and care are also discussed.

Dynamics and Regulation of RecA Polymerization and De-Polymerization on Double-Stranded DNA

10.1371/journal.pone.0066712PLoS ONE86

Cytotoxic Anti-Cancer Activity of Certain Thermotropic Liquid Crystalline Poly (Ester-Amides) Containing 2, 6-Bis (Benzylidene)Cyclohexanone Moiety in the Main Chain

Five thermotropic liquid crystalline poly(ester-amides) were synthesized by polycondensation method. The poly(ester-amides) were synthesized from varying dicarboxylic acids with a common diamine namely 4,4'-diaminobenzene and a common diol namely 2,6-bis(4-hydroxybenzylidene))cyclohexanone. For qualitative characterization, viscosity measurements and solubility data were used for these synthesized poly(ester-amides). The spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR were performed to investigate the microstructural features of these synthesized poly(ester-amides). The thermal phase transition behavior of these poly(ester-amides) were studied by Differential Scanning Calorimetry (DSC) and Hot-stage Optical Polarized Microscopy (HOPM). The degree of crystallinity was assessed by X-ray diffraction (XRD) patterns. Scanning Electron Microscopic (SEM) technique was used to illustrate the morphology of these poly(ester-amides). The copolymer synthesized was subjected into in vitro anti-cancer activity studies against human breast cancer (MCF-7) cell line. Keywords: Bisbenzylidenecyclohexanone; poly(ester-amides); polycondensation; thermotropic liquid crystalline properties; cytotoxicity, anticancer

Awareness about pictorial warnings on tobacco products and its impact on tobacco consumers in coastal Karnataka

Background: Tobacco use is a major risk factor for many chronic diseases, including cancer. India revised the pictorial warnings on all tobacco products in 2018, but its impact on tobacco consumers after the revision is less studied. Aim and Objective: To assess the awareness of the revised pictorial warnings on tobacco products and the impact of it on tobacco consumers in a coastal town. Methods: This cross-sectional study was conducted from 1st to 31st March 2021 among 185 adult tobacco consumers in a coastal town in Karnataka after obtaining ethical clearance and informed consent. The data was analysed using SPSS version 16.0 by descriptive statistics, Chi-square, Fisher’s exact test and binary logistic regression analysis. Results: Majority (95.7%) were males and 96.2% had seen the pictorial warning on the tobacco products. The commonly consumed tobacco products were panmasala (44.9%), gutka (38.9%), cigarette (31.4%) and bidi (15.1%). The mean age of initiation of consuming tobacco products was 24.8 years and mean duration of the habit was 17 years. Conclusions: A majority (96.2%) have seen the pictorial warnings on the tobacco products and significant predictors for reducing tobacco consumption were those who inferred the pictorial warnings as tobacco is injurious to health and cancerous

The serum zinc concentration as a potential biological marker in patients with major depressive disorder

Despite many clinical trials assessing the role of zinc in major depressive disorder (MDD), the conclusions still remain ambiguous. The aim of the present clinical study was to determine and comparison the zinc concentration in the blood of MDD patients (active stage or remission) and healthy volunteers (controls), as well as to discuss its potential clinical usefulness as a biomarker of the disease. In this study 69 patients with current depressive episode, 45 patients in remission and 50 controls were enrolled. The zinc concentration was measured by electrothermal atomic absorption spectrometry (ET AAS). The obtained results revealed, that the zinc concentration in depressed phase were statistically lower than in the healthy volunteers [0.89 vs. 1.06 mg/L, respectively], while the zinc level in patients achieve remission was not significantly different from the controls [1.07 vs. 1.06 mg/L, respectively]. Additionally, among the patients achieve remission a significant differences in zinc concentration between group with and without presence of drug-resistance in the previous episode of depression were observed. Also, patients in remission demonstrated correlation between zinc level and the average number of depressive episodes in the last year. Serum zinc concentration was not dependent on atypical features of depression, presence of psychotic symptoms or melancholic syndrome, age, age of onset or duration of disease, number of episodes in the life time, duration of the episode/remission and severity of depression measured by the Hamilton Rating Scale for Depression (HDRS), and the Montgomery-Asberg Depression Rating Scale (MADRS). Concluding, our findings confirm the correlation between zinc deficit present in the depressive episode, and are consistent with the majority of previous studies. These results may also indicate that serum zinc concentration might be considered as a potential biological marker of MDD

Modélisation du comportement thermomécanique du polyuréthane à mémoire de forme en grandes déformations.

Le polyuréthane thermoplastique à mémoire de forme est un matériau ?'intelligent'', réactif, capable de répondre à un stimulus thermique en déployant de grandes déformations et de retrouver ensuite sa forme initiale lors d'un cycle thermomécanique. Cette réversibilité totale est possible sur plusieurs cycles. Afin de Dimensionner un composant à mémoire de forme dans un système mécanique, un modèle de simulation numérique thermo-viscoélastique en grandes déformations de l'effet mémoire de forme est proposé. L'identification des paramètres de ce modèle est réalisée sur la base d'essais thermomécaniques (analyse mécanique dynamique DMA, traction-relaxation en température, recouvrements libres et contraints). La loi de comportement ainsi formulée, qui découple la contrainte hyperélastique et la contrainte viscoélastique, est programmée dans le logiciel de simulation numérique Comsol Multiphysics. Les résultats de la simulation montrent une très bonne concordance avec la réponse expérimentale du matériau au cours de plusieurs cycles de mémoire de forme

Simultaneous plasticization and blending of isolated soy protein with poly(butylene succinate-co-adipate)

International audienceAgrarian proteins, due to their good film forming properties, moderate cost, and biodegradable nature, have been extensively studied to develop affordable packaging materials. However, when compared to conventional polymers, isolated proteins based polymers have poor mechanical and barrier properties. Blending with others polymers seems to be a viable option to overcome these issues. The present work focuses on the preparation of isolated soy protein (ISP) / poly[(butylene succinate)-coadipate] (PBSA) blends with different ratios by extrusion and injection moulding using glycerol and water mixture as plasticizer. PBSA is bio-based, biodegradable, and its relatively low melting point is compatible with the processing temperature of ISP. Two different processing strategies were used and compared for the preparation of blends. In the novel single step approach, ISP, plasticizers (glycerol and water) and PBSA are dry mixed and extruded all together in a co-rotating twin-screw extruder. In the regular two-step approach, plasticized protein is prepared by extrusion of ISP with a glycerol/water mixture, followed by a second extrusion step of plasticized protein with PBSA. Prepared blends were characterized for their morphology, thermal, dynamic mechanical and mechanical properties. The mechanical properties of the blends prepared by single step process are roughly similar to those produced by two-step process; this indicates the efficiency of one-step melt processing of PBSA with isolated soy protein involving plasticization, denaturation, melt-melt mixing and morphology development in the extruder, this compounding method being moreover less time consuming