T-cell epitopes of the La/SSB autoantigen: prediction based on the homology modeling of HLA-DQ2/DQ7 with the insulin-B peptide/HLA-DQ8 complex

T-cell epitopes are important components of the inappropriate response of the immune system to self-proteins in autoimmune diseases. In this study, the candidate T-cell epitopes of the La/SSB autoantigen, the main target of the autoimmune response in patients with Sjogren's Syndrome (SS), and Systemic Lupus Erythematosus (SLE) were predicted using as a template the HLA-DQ2 and DQ7 molecules, which are genetically linked to patients with SS and SLE. Modeling of DQ2 and DQ7 was based on the crystal structure of HLA-DQ8, an HLA molecule of high risk factor of type I diabetes, which is also an autoimmune disease. The quality and reliability of the modeled DQ2 and DQ7 was confirmed by the Ramachandran plot and the TINKER molecular modeling software. Common and/or similar candidate T-cell epitopes, obtained by comparing three different approaches the Taylor's sequence pattern, the TEPITOPE quantitative matrices, and the MULTIPRED artificial neural network, were subjected to homology modeling with the crystal structure of the insulin-B peptide complexed with HLA-DQ8, and the best superposed candidate epitopes were placed into the modeled HLA-DQ2 and DQ7 binding grooves to perform energy minimization calculations. Six T-cell epitopes were predicted for HLA-DQ7 and nine for HLA-DQ2 covering parts of the amino-terminal and the central regions of the La/SSB autoantigen. Residues corresponding to the P1, P4, and P9 pockets of the HLA-DQ2 and DQ7 binding grooves experience very low SASA because they are less exposed to the microenvironment of the groove. The proposed T-cell epitopes complexed with HLA-DQ2/DQ7 were further evaluated for their binding efficiency according to their potential interaction energy, binding affinity, and IC50 values. Our approach constitutes the ground work for a rapid and reliable experimentation concerning the T-cell epitope mapping of autoantigens, and could lead to the development of T-cell inhibitors as immunotherapeutics in autoimmune diseases.     

The Distribution of Total Particulate Matter (TPM) And Nicotine Between Mainstream and Sidestream Smoke in Bidis and Cigarettes

ABSTRACT

The mainstream (MS) and sidestream (SS) smoke of three types of popular Indian cigarettes, a brand of low tar Indian cigarettes, a brand of US cigarettes and two brands of popular Indian bidis were analysed for carcinogenic total particulate matter (TPM) and nicotine levels employing standard smoking conditions and/or modified smoking standards.

The analysis clearly demonstrated relatively higher levels of TPM and nicotine in MS of three types of popular Indian cigarettes when compared with a brand of low tar Indian cigarettes or a brand of US cigarettes or reported values for MS of western cigarettes. This was also reflected in MS/SS ratios of TPM and nicotine as TPM and nicotine levels in SS of Indian and US cigarettes were similar, when tested employing standard smoking conditions.

Comparative analysis of Indian bidis/cigarettes and a brand of US cigarettes employing modified smoking standard (i.e. 2 puffs/min instead of 1 puff/min) revealed significantly lower values of TPM and nicotine in SS of Indian bidis when compared with corresponding values in Indian/US cigarettes. This shows that contribution of TPM and nicotine in SS from a single bidi to environmental tobacco smoke (ETS) is very much less than that of a single cigarette, and contribution of SS from Indian and US cigarettes to ETS appear to be similar. Reduced levels of TPM and nicotine in SS of bidis, probably due to lack of added burning agents, result into relatively higher deliveries of TPM and nicotine in MS as reflected by higher MS/SS values.     

Enhanced biogas production from anaerobic codigestion of solid waste by sonolysis

This paper examines the effectiveness of sonolysis in improving the anaerobic biodegradability of the organic fraction of municipal solid waste coming from mechanical selection, thus enhancing biogas production and energy recovery as well.Methane yield of solid organic material anaerobic digestion is significantly affected by substrate availability that was evaluated, in this investigation, through organic matter solubilisation tests carried out at different conditions of ultrasound treatment. Results show that sonolysis can significantly improve the solubilisation of organic solid waste, thus allowing higher biogas production from anaerobic treatment of sonicated substrates. After 45 days, the biogas produced during anaerobic codigestion tests for the sonicated mixture was 24% higher than untreated one.Therefore, these results can lay the basis for the development of technologies useful to produce high biogas quantities, in order to improve clean energy generation from biowaste.     

晶体材料中3d2态离子自旋哈密顿参量的微观起源

采用了中间场耦合图像，考虑了以前研究中被忽略的SS (spin-spin)磁相互作用以及SOO (spin-other-orbit)磁相互作用，利用完全对角化方法，研究了3d₂态离子在三角对称 (C_3v, D₃, D_3d)晶体中自旋哈密顿(SH)参量的微观起源.发现自旋哈密顿参量 (包括零场分裂参量D和g因子g∥,g⊥)来自四种耦合机理：（1）SO (spin-orbit)耦合机理; (2) SS耦合机理；（3）SOO 关键词： 自旋哈密顿参量 2态离子')" href="#">3d₂态离子 三角对称晶场 SS与SOO作用 SO-SS-SOO联合作用机理     

Determination of selenium in infant foods using electrothermal atomic absorption spectrometry with direct slurry sample introduction

Slurry sampling electrothermal atomic absorption (SS ETAAS) was applied to the development of a sensitive and precise method for selenium determination in infant foods without sample pretreatment. Suspensions prepared in a medium containing 0.1% Triton X-100, 0.5 or 5% v/v concentrated HNO₃ were directly introduced into the furnace. The accuracy of the procedure was confirmed by analysis of a standard reference material and comparison with hydride generation atomic absorption spectrometric (HGAAS) procedure. The characteristic mass is 44 pg and detection limit 0.43 μg·l⁻¹.     

Response surface methodology for the modelling of copper removal from aqueous solutions using micellar-enhanced ultrafiltration

Response surface methodology (RSM) was used to study the cumulative effect of the various parameters, namely surfactant (sodium dodecyl sulphate (SDS), anionic) concentration, pH, and surfactant/metal molar ratio and to optimise the process conditions for the maximum removal of copper from aqueous solutions via micellar-enhanced ultrafiltration (MEUF). For obtaining the mutual interaction between the variables and optimising these variables, a central composite design (CCD) by use of response surface methodology was employed. The analysis of variance (ANOVA) of the quadratic model demonstrated that the model was highly significant. The model was statistically tested and verified by experimentation. Values of pH at the range of ca. 7.5 were very successful for the separation. The maximum rejection coefficient of 98.4% was obtained for the following optimal conditions: SDS/Cu²⁺ molar ratio *r = 7.85, *pH 7.36, *C_surf = 6.82 g/l SDS. A modification of micellar-enhanced ultrafiltration for the removal of copper from aqueous solutions was studied by the implementation of sodium dodecyl sulphate–polyethylene glycol (PEG) aggregates. A full factorial design (FFD) was employed for studying the effect of molar ratio of surfactant/metal, pH and mass ratio of surfactant/polymer at a constant concentration of surfactant equal to 5 g/l. The comparison of the two systems in the region of their common factors showed that the addition of polyethylene glycol caused a slight increase in rejection coefficient of copper but also could function as ‘scavenger’ for surfactant species.     

Electrochemical impedance spectroscopy as a highly sensitive tool for a dynamic interaction study between heparin and antithrombin: a novel antithrombin sensor

Specific recognition between two biological partners is widely exploited in biosensors nowadays. To explore this avenue, a novel biosensor for antithrombin (AT) detection was constructed. Heparin was used as the affinity ligand.A well-known acrylic monomer (butyl methacrylate) was polymerized and grafted onto the heparin polysaccharide by the use of ceric ammonium nitrate as a redox initiator in aqueous nitric acid medium. Polymers were deposited as a thin layer onto surface of stainless steel electrode (SS316L).The obtained polymers were studied by Fourier transform infrared spectroscopy (FTIR) and analyzed by differential scanning calorimetry (DSC).Moreover, the films were characterized by electrochemical impedance spectroscopy (EIS), contact-angle measurements and AFM.EIS was used to study the biosensor affinity to AT and the relationship between functionalization growth of modified electrode and the response of the sensor.The proposed approach appears to be simple, sensitive and correlated with methods that analyse the detection of antithrombin.     

Corrosion mitigation on orthodontic wire made of SS 18/8 alloy using esomeprazole tablet (Esiloc-40 mg) in artificial saliva

The corrosion inhibition of orthodontic wire made of SS 18/8 alloy in artificial saliva, with and without the presence of tablet esomeprazole − 40 mg has been investigated by electrochemical analysis. Polarisation study indicates that in the presence of the mentioned tablet, polarisation resistance (R_p) value increases and corrosion current (I_corr) decreases. That is, the corrosion resistance of SS 18/8 alloy in artificial saliva increases. AC impedance spectroscopy reveals that charge transfer resistance value (R_ct) value increases and double layer capacitance value (C_dl) decreases. The open circuit potential (OCP) values for the inhibited system are more negative than that of the uninhibited blank system. The vibration peaks obtained from the FTIR spectra indicates the presence of functional group in esomeprazole pill and these characteristic peaks are slightly shifted in the analyzed scratched film from the surface of the orthodontic wire after immersion. AFM micrograph image of the polished specimen sample immersed in artificial saliva (AS) with esomeprazole tablet solution shows lesser degree of surface deterioration than those for SS 18/8 specimen immersed only in artificial saliva. From the present work, it is reported that people clipped with orthodontic wire made of SS 18/8 alloy need not worry about orthodontic corrosion for taking esomeprazole tablet for the treatment of gastro esophageal reflux disease and other medicinal purpose.