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Mimicking the enzymatic plant cell wall hydrolysis mechanism for the degradation of polyethylene terephthalate

Plastic pollution presents a global challenge, impacting ecosystems, wildlife, and economies. Polyethylene terephthalate (PET), widely used in products like bottles, significantly contributes to this issue due to poor waste collection. In recent years, there has been increasing interest in plant biomass-degrading enzymes for plastic breakdown, due to the structural and physicochemical similarities between natural and synthetic polymers. Filamentous fungi involved in hemicellulose degradation have developed a complex mode of action that includes not only enzymes but also biosurfactants; surface-active molecules that facilitate enzyme-substrate interactions. For this reason, this study aimed to mimic the mechanism of biomass degradation by repurposing plant cell wall degrading enzymes including a cutinase and three esterases to cooperatively contribute to PET degradation. Surfactants of different charge were also introduced in the reactions, as their role is similar to biosurfactants, altering the surface tension of the polymers and thus improving enzymes’ accessibility. Notably, Fusarium oxysporum cutinase combined with anionic surfactant exhibited a 2.3- and 1.6-fold higher efficacy in hydrolyzing amorphous and semi-crystalline PET, respectively. When cutinase was combined with either of two ferulic acid esterases, it resulted in complete conversion of PET intermediate products to TPA, increasing the overall product release up to 1.9– fold in presence of surfactant. The combination of cutinase with a glucuronoyl esterase demonstrated significant potential in plastic depolymerization, increasing degradation yields in semi-crystalline PET by up to 1.4-fold. The approach of incorporating enzyme cocktails and surfactants emerge as an efficient solution for PET degradation in mild reaction conditions, with potential applications in eco-friendly plastic waste management.

Salicylic acid functionalized zein for improving plant stress resistance and as a nanopesticide carrier with enhanced anti-photolysis ability

BackgroundThere is a serious global problem of salinization of arable land, causing large reduction in world food production. Use of plant hormones is an effective way to reduce damage caused to crops and salt stress.ResultsIn this study, PEI-EDA was modified with AM-zein and grafted with plant hormone SA (AM-zein-SA) and used as a nano-pesticide carrier to load emamectin benzoate (EB). The use of AM-zein-SA as a nano-pesticide carrier could reduce the damage caused by salt stress to crops. The structure of AM-zein-SA was characterized by FTIR, UV, fluorescence, Raman, and 1H NMR spectroscopic techniques. AM-zein-SA could effectively improve the resistance of EB to ultraviolet radiations, resistance of cucumber to salt stress, and the absorption of EB by plants. The experimental results showed that AM-zein-SA could effectively improve the anti-UV property of EB by 0.88 fold. When treated with 120 mmol NaCl, the germination rate of cucumber seeds under salt stress increased by 0.93 fold in presence of 6.25 mg/L carrier concentration. The POD and SOD activities increased by 0.50 and 1.21 fold, whereas the content of MDA decreased by 0.23 fold. In conclusion, AM-zein-SA nano-pesticide carrier could be used to improve the salt resistance of crops and the adhesion of pesticides to leaves.ConclusionAM-zein-SA, without undergoing any changes in its insecticidal activity, could simultaneously improve the salt stress resistance and salt stress germination rate of cucumber, reduce growth inhibition due to stress under high-concentration salt, and had a good effect on crops. In addition, EB@AM-zein-SA obviously improved the upward transmission rate of EB, as compared with EB. In this study, SA was grafted onto zein-based nano-pesticide carrier, which provided a green strategy to control plant diseases, insects, and pests while reducing salt stress on crops in saline-alkali soil.Graphical

In vitro activity of celastrol in combination with thymol against carbapenem-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial and community-acquired infections. Klebsiella has developed resistance against antimicrobials including the last resort class; carbapenem. Currently, treatment options for carbapenem-resistant-Klebsiella (CRK) are very limited. This study aims to restore carbapenem effectiveness against CRK using celastrol and thymol. Clinical Klebsiella isolates were identified using biochemical and molecular methods. Antimicrobial susceptibility was determined using disk-diffusion method. Carbapenemase-production was tested phenotypically and genotypically. Celastrol and thymol-MICs were determined and the carbapenemase-inhibitory effect of sub-MICs was investigated. Among 85 clinical Klebsiella isolates, 72 were multi-drug-resistant and 43 were meropenem-resistant. Phenotypically, 39 isolates were carbapenemase-producer. Genotypically, blaNDM1 was detected in 35 isolates, blaVIM in 17 isolates, blaOXA in 18 isolates, and blaKPC was detected only in 6 isolates. Celastrol showed significant inhibitory effect against carbapenemase-hydrolytic activity. Meropenem-MIC did not decrease in presence of celastrol, only 2-fold decrease was observed with thymol, while 4–64 fold decrease was observed when meropenem was combined with both celastrol and thymol. Furthermore, thymol increased CRK cell wall-permeability. Molecular docking revealed that celastrol is superior to thymol for binding to KPC and VIM-carbapenemase. Our study showed that celastrol is a promising inhibitor of multiple carbapenemases. While meropenem-MIC were not affected by celastrol alone and decreased by only 2-folds with thymol, it decreased by 4–64 folds in presence of both celastrol and thymol. Thymol increases the permeability of CRK-envelope to celastrol. The triple combination (meropenem/celastrol/thymol) could be useful for developing more safe and effective analogues to restore the activity of meropenem and other β-lactams.

Binding of the Mycobacterium tuberculosis EccCb1 ATPase double hexameric ring to the EsxAB virulence factor is enhanced by ATP.

The EccC enzyme of Mycobacterium tuberculosis ESX-1 secretion system is involved in EsxAB virulence factor secretion and offers an attractive target for antivirulence inhibitors development against M. tuberculosis. The EccCb1 polypeptide of the EccC enzyme contains two Ftsk/SpoIIIE type ATPase domains (D2 and D3) and binds to the EsxAB factor at the C-terminal region of the D3 domain. In the current study, we have determined a low-resolution structure of EccCb1, and its mechanism involved in ATPase activity and EsxAB factor binding. Small-angle X-ray scattering data yielded a double hexameric ring structure of EccCb1 in solution and was further confirmed by SEC-MALS and dynamic light scattering. ATPase activity of wild-type, D2, and D3 mutants showed that D2-K90A and D3-K382A mutations led to a complete loss of enzyme activity. The full-length EccCb1 showed ∼3.7-fold lower catalytic efficiency than D2 domain and ∼1.7 fold lower than D3 domain. The EsxAB factor binds EccCb1 with Kd ∼ 11.3 ± 0.6 nM and its affinity is enhanced ∼2 fold in presence of ATP + Mg2+. These data indicate the involvement of ATPase activity in EsxAB factor translocation. Molecular dynamics simulation on wild-type, ATP + Mg2+, and EsxAB + ATP + Mg2+ bound EccCb1 double-ring structure showed enhanced stability of enzyme upon ATP + Mg2+ and EsxAB binding. Overall, our study showed a low-resolution structure of EccCb1, and the mechanism involved in ATPase activity and EsxAB factor recognition, which can be targeted for the development of antivirulence drugs against M. tuberculosis.

An evaluation of lipid profile and pro-inflammatory cytokines as determinants of cardiovascular disease in those with diabetes: a study on a Mexican American cohort

Sedentary life styles coupled with high-calorie diets and unhealthy social habits such as smoking, have put an ever-increasing number of people at risk of cardiovascular disorders (CVD), worldwide. A concomitant increase in the prevalence of type 2-diabetes (hyperglycemia), a risk factor for CVD, has further contributed towards escalating CVD-related mortalities. The increase in number of cases of type 2-diabetes underscores the importance of early diagnosis of cardiovascular disease in those with diabetes. In this work, we have evaluated the sensitivity and specificity of dyslipidemia and proinflammatory cytokines to be used as biomarkers for predicting the risk of CVD in those with diabetes. We hypothesize that interplay between dyslipidemia and diabetes-induced low-grade inflammation in those with type 2-diabetes increases the risk of CVD. A total of 215 participants were randomly recruited from the Cameron County Hispanic Cohort (CCHC). Of these, 99% were Mexican Americans living on Texas-Mexico border. Levels of cytokines, adipokines and lipid profile were measured. Cardiovascular disease (CVD) for this study was defined as prior diagnosis of heart attack, angina and stroke, while diabetes was defined by fasting blood glucose (FBG) of > 100 mg/dL and HbA1c of > 6.5, in accordance with American Diabetes Association (ADA) guidelines. Depending on type and distribution of data, various statistical tests were performed. Our results demonstrated higher rates of heart attack (14% vs 11.8%) and stroke (19.8% vs 10%) in those with diabetes as compared to non-diabetes. The odds of having a heart attack were eight times higher in the presence of elevated triglycerides and pro-inflammatory markers (TNFα and IL6) as compared to presence of pro-inflammatory markers only. The odds for heart attack among those with diabetes, increased by 20 fold in presence of high levels of triglycerides, TNFα, and IL6 when coupled with low levels of high-density lipid cholesterol (HDL-C). Lastly, our analysis showed that poorly controlled diabetes, characterized by HbA1c values of > 6.5 increases the odds of stroke by more than three fold. The study quantifies the role of lipid profile and pro-inflammatory markers in combination with standard risk factors towards predicting the risk of CVD in those with type 2-diabetes. The findings from the study can be directly translated for use in early diagnosis of heart disease and guiding interventions leading to a reduction in CVD-associated mortality in those with type 2-diabetes.

Divalent Cations and Lipid Composition Modulate Membrane Insertion and Cancer-Targeting Action of pHLIP

The pH-Low Insertion Peptide (pHLIP) has emerged as an important tool for targeting cancer cells; it has been assumed that its targeting mechanism depends solely on the mild acidic environment surrounding tumors. Here, we examine the role of Ca2+ and Mg2+ on pHLIP's insertion, cellular targeting, and drug delivery. We demonstrate that physiologically relevant concentrations of either cation can shift the protonation-dependent transition by up to several pH units toward basic pH and induce substantial protonation-independent transmembrane insertion of pHLIP at pH as high as 10. Consistent with these results, the ability of pHLIP to deliver the cytotoxic compound monomethyl-auristatin-F to HeLa cells is increased several fold in presence of Ca2+. Complementary measurements with model membranes confirmed this Ca2+/Mg2+-dependent membrane-insertion mechanism. The magnitude of this alternative Ca2+/Mg2+-dependent effect is also modulated by lipid composition—specifically by the presence of phosphatidylserine—providing new clues to pHLIP's unique tumor-targeting ability in vivo. These results exemplify the complex coupling between protonation of anionic residues and lipid-selective targeting by divalent cations, which is relevant to the general signaling on membrane interfaces.

A kinetic study on the degradation and biodegradability of silver nanoparticles catalyzed Methyl Orange and textile effluents

The present study includes the Azadirachta indica (neem) induced Silver nanoparticles (AgNPs) by green synthesis as reducing and capping agent. Synthesized AgNPs were characterized by different instrumental techniques such as XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), Zetasizer, UV-Visible and FT-IR (Fourier Transformation Infra-Red) spectroscopy. The result of XRD reveals that nanoparticles were crystalline in nature and pure, stability was determined by Zeta potential and SEM, TEM analysis indicates that AgNPs was monodisperse in a spherical shape with average size 9 nm. These synthesized AgNPs were applied as the catalyst in the degradation process of Methyl Orange (MO) and wastewater samples in presence of peroxodisulphate (PDS). Effect of different experimental conditions such as initial pH, concentration of PDS, Dye, and AgNPs was studied on the degradation process. The obtained kinetic result shows that AgNPs/PDS system induces 1.1 × 10−4 to 15.9 × 10−4 s-1 folds in presence of the small concentration of AgNPs (1 × 10−8 mol dm−3). The degradation of MO and real wastewater samples in AgNPs/PDS system is followed pseudo-first order kinetics and maximum degradation of MO reached 88% in 40 min and real wastewater samples in 80 min. Liquid chromatography-mass spectrometry (LC-MS) analysis and UV-Visible spectral changes were used to analyze the structure of intermediate and end products (CO2, H2O, NO3−, and O3S−) during the degradation process. Furthermore, the result of biodegradability index (greater than 0.3) implies that advanced oxidation process enhances the biodegradability of wastewater.

Potential of an electrospun composite scaffold of poly (3-hydroxybutyrate)-chitosan/alumina nanowires in bone tissue engineering applications

The choice of material types for tissue engineering scaffolds and the design of methods are contributive in yielding the proper result. In this study, 1–5% wt. Alumina nanowires are added to (Polyhydroxybutyrate-Chitosan) PHB-CTS alloy solution, and the scaffolds are prepared by electrospinning method. The fiber diameters, porosity percentages and uniform distribution of Alumina nanowires are assessed by SEM, EDS and TEM. The surface roughness of the fibers is confirmed by FESEM and AFM. The crystallinity of nanofibers is calculated by DSC and verified by FTIR. The tensile strength of the PHB-CTS scaffold increase up to >10 fold in presence of 3% wt. Alumina. Formation of calcium phosphate sediments only on the surface of Alumina containing scaffolds after 7 and 28 days of immersion in SBF is observed by SEM, and verified by XRD analysis. Proliferation and viability of MG-63 cells and alkaline phosphatase secretion are significantly higher on scaffolds containing Alumina than that of the PHB or PHB-CTS. The appropriate properties of Alumina which affected in cell behavior, hydrophilicity enhancement, bioactivity and mechanical properties make it contribution agent in bone tissue engineering.

Silac-based quantitative proteomic analysis of Lactobacillus reuteri CRL 1101 response to the presence of selenite and selenium nanoparticles

Stable isotope labeling in cell culture (SILAC) was applied for the first time on a lactic acid bacterium strain (L. reuteri CRL1101) for analyzing differential protein expression associated to selenite(Na2SeO3) and selenium nanoparticles (SeNPs) exposure. 57 and 47 proteins were found de-regulated by >1,5 fold in presence of selenite and SeNPs, respectively. Only 16 out of 104 proteins differentially expressed were commonly altered by selenite and SeNPs. The use of a clustered heat map allows us to visualize relations between the de-regulated proteins and exposure conditions. We identified a number of proteins involved in diverse functions and biological processes such as metabolism of carbohydrates, selenium and lipids; folding, sorting and degradation; environmental information and processing. In presence of both, selenite and SeNPs, proteins related to selenium metabolism such as cystathione beta-lyase and oxidoreductases (thioredoxine reductase and NAD/FAD oxidoreductase) were over expressed. Interestingly, the over expression of thioredoxin reductase could protect the host from oxidizing compounds. An over expression of phage proteins and chaperones with selenite was observed; this result and the fact that a lower cell count was detected when selenite was added could indicate that this latter Se species has a more deleterious effect than the nanoparticles.

Isolation, characterization and exploring biotechnological potential of halophilic archaea from salterns of western India.

Thirteen halophilic archaea were isolated from Kandla and Bhayander salt pans. These isolates were grouped into three different genera Halobacterium, Haloferax and Haloarcula based on morphological and biochemical characterization, polar lipid analysis, Amplified 16S rDNA restriction analysis (ARDRA) and 16S rDNA sequence analysis. Biochemical characterization suggested the ability of isolates to produce protease, amylase and poly-hydroxybutyrate (PHB) indicating their biotechnological potential. The isolates were further screened for the amount of extracellular protease produced. Halobacterium sp. SP1(1) showed significant protease production compared to other isolates. Protease producing ability of the isolate was influenced by several factors such as NaCl concentration, type of protein source, metal ions and surfactants, and presence of amino acid supplements in the production medium. Soybean flour, FeCl3 and dicotylsulfosuccinate were found to increase protease production by 2.36, 1.54 and 1.26 folds, respectively compared to production in basal medium. Effect of organic solvents used in paints (n-decane, n-undecane and n-dodecane) was also investigated on protease production by the isolate. Protease production by Halobacterium sp. SP1(1) was enhanced by 1.2 folds in presence of n-decane compared to control. Furthermore, the ability of isolate to hydrolyse fish protein was investigated using three different edible fishes (Pomfret, Flat fish and Seer fish) as sole protein source. Pomfret was found to be a good protein source for protease production by the isolate. These results revealed that Halobacterium sp. SP1(1) may have potential for paint-based antifouling coating preparations and fish sauce preparation by virtue of its extracellular protease.

Reversible ‘turn off’ fluorescence response of Cu2+ ions towards 2-pyridyl quinoline based chemosensor with visible colour change

A novel chemosensor, 4(1H-benzo[d]imidazol-2-yl)-2-(pyridin-2-yl)quinoline is described which could selectively detect Cu2+ ions. Addition of Cu2+ ions changes solution of chemosensor from colourless to yellow which is clearly visible to the naked eyes. Fluorescence of chemosensor was quenched by 18 folds in presence of Cu2+ ions. Cu2+ ions sensing property of chemosensor was remained unaffected in presence of other metal ions (Na+, Mg2+, K+, Mn2+, Ca2+, Fe2+, Co2+, Zn2+, Cd2+, Ba2+, Hg2+ and Pb2+). Moreover, the sensing of Cu2+ was found to be reversible, since the Cu2+ induced quenching of emission spectra was reversed upon addition of EDTA. The stoichiometry of binding of chemosensor and Cu2+ was determined by Job‘s plot which was found to be 1:1 and further it was confirmed by ESI-MS analysis. Binding of Cu2+ ions to chemosensor was studied over the wide pH range and the result demonstrated maximum fluorescence quenching in the pH range of 3.0–10. The binding association constant (Ka) value determined from Benesi–Hildebrand equation was 3.38×105M−1.

Investigations of polyethylene glycol mediated ternary molecular inclusion complexes of silymarin with beta cyclodextrins

Objective To evaluate the effect of Polyethylene glycol and β-cyclodextrin on the solubility and dissolution of silymarine, a poorly water soluble herbal drug. Methodology Effects of beta cyclodextrins and Polyethylene glycol on solubility of sylimarine were evaluated by phase solubility studies both separately as well as in combination. Solid inclusion complexes of silymarine –β-cyclodextrin in 1:1 molar ratio were prepared with and without polyethylene glycol by kneading method then evaluated for solubility dissolution and physical nature by XRD, FT-IR and NMR spectroscopy studies. Results The aqueous solubility of silymarine was linearly increased as a function of the concentration of β-cyclodextrin alone and in the presence of polyethylene glycol. Beta cyclodextrin formed molecular inclusion complexes with sylimarine in1:1 molar ratio as revealed by phase solubility diagram. The ternary complexes of silymarine, β-cyclodextrin and polyethylene glycol demonstrated better dissolution than those of silymarine and its binary complexes with β-cyclodextrin alone. Silymarine - β-cyclodextrin complex caused 1.3 fold increase in the dissolution rate of silymarine, which was further increased up to 1.7 fold in presence of small amount of polyethylene glycol. Conclusion The presence of polyethylene glycol markedly enhances the molecular complexation and solubilizing efficiencies of β-cyclodextrin on sylimarine.

Cloning, expression and characterization of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Wolbachia endosymbiont of human lymphatic filarial parasite Brugia malayi.

Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for treatment of lymphatic filariasis. Although functional characterization of the Wolbachia peptidoglycan assembly has not been fully explored, the Wolbachia genome provides evidence for coding all of the genes involved in lipid II biosynthesis, a part of peptidoglycan biosynthesis pathway. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is one of the lipid II biosynthesis pathway enzymes and it has inevitably been recognized as an antibiotic target. In view of the vital role of MurA in bacterial viability and survival, MurA ortholog from Wolbachia endosymbiont of Brugia malayi (wBm-MurA) was cloned, expressed and purified for further molecular characterization. The enzyme kinetics and inhibition studies were undertaken using fosfomycin. wBm-MurA was found to be expressed in all the major life stages of B. malayi and was immunolocalized in Wolbachia within the microfilariae and female adults by the confocal microscopy. Sequence analysis suggests that the amino acids crucial for enzymatic activity are conserved. The purified wBm-MurA was shown to possess the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) like activity at a broad pH range with optimal activity at pH 7.5 and 37°C temperature. The apparent affinity constant (K m) for the substrate UDP-N-acetylglucosamine was found to be 0.03149 mM and for phosphoenolpyruvate 0.009198 mM. The relative enzymatic activity was inhibited ∼2 fold in presence of fosfomycin. Superimposition of the wBm-MurA homology model with the structural model of Haemophilus influenzae (Hi-MurA) suggests binding of fosfomycin at the same active site. The findings suggest wBm-MurA to be a putative antifilarial drug target for screening of novel compounds.

Coumarin based dual switching fluorescent ‘turn-on’ chemosensor for selective detection of Zn2+ and HSO4−: an experimental and theoretical study

A coumarin based fluorescence ‘turn-on' chemosensor (HL) for the selective detection of Zn2+ and HSO4¬ has been developed. Emission intensity of HL is enhanced by 27 and 17 fold in presence of Zn2+ and HSO4¬ respectively. Theoretical study interprets the electronic structure and sensing mechanism of HL.

Ratiometric fluorescence sensing ability of 2-(2′-hydroxyphenyl)benzimidazole and its nitrogen substituted analogues towards metal ions

Excited state intramolecular proton transfer (ESIPT) based ratiometric fluorescence sensing of 2-(2′-hydroxyphenyl)benzimidazole (HPBI) and its nitrogen substituted analogues viz. 2-(2′-hydroxyphenyl)-3H-imidazo[4,5-b]pyridine (HPIP-b) and 2-(2′-hydroxyphenyl)-1H-imidazo[4,5-c]pyridine (HPIP-c) towards different metal ions was studied. The normal to tautomer fluorescence intensity ratio of HPBI increases as high as 143 and 92 folds in presence of Cu2+ and Fe3+, respectively. The ratio of HPIP-b reaches maximum up to 4.7 fold in presence of Co2+ and that of HPIP-c up to 11.6 fold in presence of Pd2+. The increase in intensity ratio of the normal emission in presence of metal ions is attributed to inhibition of ESIPT process. The crystal structure of 1:2 Ni2+ complex of HPIP-b indicates that the metal ion coordinates through imidazole nitrogen and phenolic oxygen of the fluorophores.

MAPK pathway mediates muscarinic receptor-induced human lung fibroblast proliferation

Airway remodelling is a pathological feature of chronic inflammatory and obstructive airway diseases like asthma and COPD wherein fibroblasts contribute to structural alteration processes. We recently reported expression of multiple muscarinic receptors in human lung fibroblasts and demonstrated muscarinic receptor-induced, Gi-mediated proliferation in these cells. We now explore the underlying intracellular signalling pathways. As a measure of cell proliferation (3H)-thymidine incorporation in primary human lung fibroblasts and MRC-5 fibroblasts was increased by about 2 fold in presence of the muscarinic receptor agonist carbachol (10 μM) and this effect could be prevented by the MEK inhibitor PD 98059 (30 μM). Western blot analysis revealed a rapid (within 2 min) activation of p42/44 MAPK (ERK1, ERK2) following exposure to 10 μM carbachol or oxotremorine, effects blocked by tiotropium as well as atropine. In conclusion, the proliferative response of lung fibroblasts to muscarine receptor stimulation is mediated via activation of the classical MEK-ERK MAPK cascade. It is suggested that prevention of cholinergic driven fibroblast proliferation by prolonged blockade of airway muscarinic receptors may contribute to the reported long term beneficial effects of anticholinergics.

Human Mesenchymal Cells Regulates Naive and Memory T Regulatory Cells.

CD4(+)CD25(+)FoxP3(+) T regulatory (T reg) cells constitute 1–2% of peripheral blood cells in adults and function prevalently as immunosuppressors. 70% of T reg are memory/effector cells with a CD45RO+ phenotype. The other 30% have a naive T cell phenotype (CD45RA+). Both sub-populations exert a regulatory function and when sorted and/or purified each inhibits a mixed lymphocyte culture. In the present study, we investigated the effects of human recombinant IL-7 (rIL-7), human mesenchymal cells (hMSC) and hMSC engineered with the IL-7 gene (hMSC/IL-7) on regulatory T cells expressing a memory (CD4/CD25/CD45RO) or naive (CD4/CD25/CD45RA) phenotype. T cells from healthy donors were enriched by immnuselection to provide populations of CD45RA+ cells (95 % ± 2.9) and CD45RO+ cells (97 % ± 0.25). Enriched naive and memory cells were cultured in presence rIL-7 (100 ng/ml), hMSC (ratio 5:1) or hMSC/IL-7 (ratio 5:1). After 7 days' culture we examined the CD4/CD25+ cells within the naive and memory populations. In the naive T cell population the T reg starting fraction of 0.05 % ± 0.01 of CD4/CD25 positive cells, did not change in the presence of rIL-7 while it rose to 0.2 % ± 0.14 in presence of human MSC and more interestingly reached 1.67 % ± 0.6 in presence of IL-7 engineered human MSC. In the memory T cell population the T reg starting fraction of 0.3 % ± 0.05 of CD4/CD25 positive cells, did not change in presence of rIL-7 while it rose 1.5 % ± 0.9 in the presence of human MSC and more interestingly reached 11.55 % ± 7.5 in the presence of human IL-7 engineered-MSC. We analyzed CD127 expression within different groups. In the naive T reg starting fraction 3 % ± 1.2 expressed CD127 which was down-regulated to 0.96 % ± 0.5 in the presence of rIL-7, to 0.29 % ± 0.2 with human MSC and to 0.37 % ± 0.02 with human IL-7engineered-MSC. Memory T reg cells expressed CD127 in 15% ± 1.2 of the starting fraction which was down-regulated to 1.2 % ± 0.45 in the presence of rIL-7, to 1.32 % ± 0.34 with hMSC and to 4.01% ± 0.74 in presence of hMSC/IL-7. FoxP3 expression was measured by real time quantitative PCR in sort-purified subsets of peripheral blood, identified by staining with a combination of CD4, CD25, CD45RA or CD45RO. In naive T reg FoxP3 expression was increased 1.15 fold in the presence of hMSC and 2.7 fold in presence of hMSC/IL-7. In memory T reg FoxP3 expression was increased 1.14 fold in the presence of hMSC and 2.67 fold in presence of hMSC/IL-7. In conclusion naive T reg cells are IL-7 independent and up-regulated by human MSC. Engineering human MSC with the IL-7 gene enhanced up-regulation. Memory T reg cells are also IL-7 independent and are up-regulated by human MSC. Engineering human MSC with the IL-7 gene markedly increased up-regulation. The different regulatory systems may underlie different functions within the T reg sub-populations.

Genotypic difference in salinity tolerance of green gram cultivars

Responses of two green gram ( Phaseolus aureus) cultivars differing in salt tolerance ability were compared for seed germination efficiency, seedling vigor (root and shoot length), plant growth (dry weight (DW) and fresh weight (FW)), water uptake and intracellular Na +/K + contents during germination under the conditions of absence as well as presence of various levels of salinity. In cultivar SML-32 increasing levels of salinity remarkably decreased seed germination and caused pronounced decrease in seedling vigor, plant growth and water uptake in shoot and root compared to cultivar T-44. Intracellular sodium content of the root and shoot tissues of the cultivar SML-32 was found to be increased several folds in presence of salinity while that of the cultivar T-44 exhibited only moderate increase even at high salinity level (200 mM NaCl). However intracellular K + content of the root and shoot tissues of both the cultivars did not much increased in presence of salinity. Results suggest possible different behaviors of cultivars differing in salt tolerance with respect to germination, seedling vigor, plant growth, water content (WC) and Na +/K + contents. Based on these criteria, cultivar T-44 was considered as salt tolerant while that of SML-32 salt sensitive.

Alkali promoted selective epoxidation of styrene to styrene oxide using TS-1 catalyst

The epoxidation of styrene was carried out over titanium silicalite (TS-1) and an alkali (sodium hydroxide) in the reaction medium. This system gave a very high TOF (>200 h −1) and selectivity to styrene oxide (>92%). It was found by EPR characterization that the local coordination of Ti centers is transformed from five fold to six fold in presence of NaOH. Also, further isomerization of styrene oxide to phenylacetaldehyde is nearly suppressed by NaOH, thereby increasing the styrene oxide selectivity remarkably.