44 research outputs found

    Metal triflates catalyzed efficient synthesis of 3,4-dihydro-2H-1-benzopyrans

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    Ytterbium triflate efficiently catalyzes an unusual cyclization of o-hydroxybenzaldehydes with 2,3-dihydrofuran and 3,4-dihydro-2H-pyran in the presence of trimethyl orthoformate at ambient temperature to afford a new class of compounds, furo- and pyrano[2,3-b]benzopyrans in excellent yields with high diastereoselectivity. Also, o-hydroxybenzaldehydes reacted smoothly with acetophenones in the presence of a catalytic amount of scandium triflate under similar reaction conditions to give the corresponding 2,4-dialkoxy-2-aryl-3,4-dihydro-2H-1-benzopyrans in high yields

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Influence of Cypermethrin on DNA and RNA Content in Different Organs of Fresh Water Fish Cyprinus carpio: Effect of Cypermethrin on DNA and RNA in Fishes

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    In this study, freshwater fish Cyprinus carpio was exposed to sub lethal concentration of synthetic pyrethroids insecticide cypermethrin to evaluate the impact on nucleic acids in different organs. Fishes were exposed to sub lethal concentration (1/10th of LC50 value) of cypermethrin for three different durations, 7, 14 and 21 days. In seven day exposed fishes, DNA and RNA contents were not altered by cypermethrin. Whereas in 14 day and 21 day exposed fishes the DNA and RNA content decreased significantly in brain, gills and liver. However, the decrease was more in 21 day exposed fishes. The reduction in the DNA and RNA content in cypermethrin exposed fishes is comparatively less in liver when compared to the brain and gills. Cypermethrin treatment diminished RNA/DNA ratio in all the fish organs tested. In all the three organs studied, the influence of cypermethrin was found to be exposure time dependent

    Oral toxic exposure of titanium dioxide nanoparticles on serum biochemical changes in adult male Wistar rats

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    Objective(s): Titanium dioxide (TiO2) nanoparticles (NPs) are widely used in commercial food additives and cosmetics worldwide. Uptake of these nanoparticulate into humans by different routes and may exhibit potential side effects, lags behind the rapid development of nanotechnology. Thus, the present study designed to evaluate the toxic effect of mixed rutile and anatase TiO2 NPs on serum biochemical changes in rats. Materials and Methods: In this study, adult male Wistar rats were randomly allotted into the experimental and control groups (n=6), which were orally administered with 50 and 100 mg/kg body weight of TiO2 NPs. Toxic effects were assessed by the changes of serum biochemical parameters such as glucose, total protein, albumin, globulin, cholesterol, triglyceride, high density lipoprotein, alanine transaminase, aspartate transaminase, alkaline phosphatase, total bilirubin, blood urea nitrogen, uric acid and creatinine. All the serum biochemical markers were experimented in rats, after 14-days of post exposure. Results: Changes of the serum specific parameters indicated that liver and kidney were significantly affected in both experimental groups. The changes between the levels of total protein, glucose, aspartate transaminase, alanine transaminase and alkaline phosphatase indicate that TiO2 NPs induces liver damage. Significant increase in the blood urea nitrogen and uric acid indicates the renal damage in the TiO2 NPs treated rats. Conclusion: The data shows that the oral administration of TiO2 NPs

    Synthesis, characterization and DNA-binding properties of rac-[Ru(5,6-dmp)<SUB>2</SUB>(dppz)]<SUP>2+</SUP> - enantiopreferential DNA binding and co-ligand promoted exciton coupling

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    The new mixed ligand complex [Ru(5,6-dmp)2(dppz)]Cl2 [5,6-dmp = 5,6-dimethyl-1,10-phenanthroline, dppz = dipyrido[3,2-a:2',3'-c]phenazine] has been isolated and its DNA-binding properties studied by employing UV-visible (UV-Vis), steady-state and time-resolved emission and circular dichroism spectral methods, viscometry, thermal denaturation and cyclic/differential pulse voltammetric techniques. The complex acts as a 'molecular light-switch' on binding to DNA, but the enhancement in emission intensity is only 75% of that of the parent complex [Ru(phen)2(dppz)]2+ (phen = 1,10-phenanthroline). The emission decay curves and quenching studies suggest two different DNA-binding modes both involving intercalation of the dppz ligand of [Ru(5,6-dmp)2(dppz)]Cl2. The characteristic red-shift of the induced CD signal, which is not observed for the phen analogue, arises from exciton coupling. The hydrophobicity and polarizability of 5,6-dmp co-ligand strongly favour the formation of a stable structural and electronic scaffold on the DNA surface for the unbound molecules to couple with the DNA-bound complexes facilitating spontaneous assembly of novel extended molecular aggregates using DNA as a helical nanotemplate. This observation is consistent with the shift in Ru(II)/Ru(III) redox potential to more positive values with a dramatic drop in peak current on binding of the 5,6-dmp complex to calf thymus (CT) DNA. Equilibrium dialysis experiments monitored by CD spectroscopy unambiquously reveal the preferential binding of the &#916;-enantiomer to the right-handed calf thymus (CT) DNA. The 5,6-dmp complex exhibits preferential binding to [d(AT)6]2 over [d(GC)6]2 and the complex aggregates formed consist of six [Ru(5,6-dmp)2(dppz)]2+ cations per base pair of [d(AT)6]2; however, only one [Ru(phen)2(dppz)]2+ cation per base pair is involved in DNA binding

    Electrospun nanofibers for pharmaceutical and medical applications

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    Journal of Drug Delivery Science and Technology216451-468JDDS

    Deciphering the role of microRNA 21 in cancer stem cells (CSCs)

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    AbstractIrrespective of positive developments of cancer treatment, the mortality due to various cancers remains high and the mechanisms of cancer initiation and the development also remains mysterious. As we know that microRNAs are considered to be a short noncoding RNA molecules consisting of 21–25 nucleotides (nt) in length and they silence their target genes by inhibiting mRNA translation or degrading the mRNA molecules by binding to their 3′-untranslated (UTR) region and play a very important role in cancer biology. Recent evidences indicate that miR-21 is over expressed in cancer stem cells and plays a vital role in cell proliferation, apoptosis, and invasion. Even though an increased expression level of miR-21 has been observed in cancer stem cells, studies related to the role of miR-21 in cancer stem cells are limited. The main aim of this mini review is to explain the potency of miR-21 in various cancer stem cells (CSCs) and as a new target for therapeutic interventions of cancer progression

    Nanofiber Technology for Controlling Stem Cell Functions and Tissue Engineering

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    10.1002/9781118574775.ch2Micro and Nanotechnologies in Engineering Stem Cells and Tissues27-5

    LiBF<SUB>4</SUB>-mediated conversion of aldehydes to gem-diacetates

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    An efficient and highly selective method for the conversion of aldehydes to gem-diacetates is described using lithium tetrafluoroborate under mild reaction conditions. Due to the neutral reaction conditions, this method is compatible with acid-sensitive protecting groups such as acetonides, carbamates, THP and TBDMS ethers present in the substrate

    Influence of Aluminium Chloride on Antioxidant System in the Testis and Epididymis of Rats

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    Background: In recent years, the use of chemicals in agriculture, industry, and public health has become so common that the environment is continuously contaminated by the toxic substance-like metals. Aluminum released due to anthropogenic activities such as mining and industrial uses. Aluminium has several industrial uses. The present study was designed to investigate the effect of aluminium chloride (AlCl3) on enzymatic and non-enzymatic antioxidants in the testis and epididymis of rats. Methods: Adult male rats were administered with aluminium chloride at two different doses, 50 mg and 100 mg/kg body weight, orally, daily for 45 days. At the end of the experimental period, the animals were sacrificed and their testis and the epididymis were removed. Antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-s-transferase (GST) were assayed. Lipid peroxidation (LPO), vitamin C, and vitamin E levels were also determined. Results: Aluminium chloride administration had no effect on the bodyweight of the animals but the weight of the testis and epididymis was decreased. Almost all the antioxidant enzymes studied markedly diminished in the testis and epididymis of aluminium chloride treated animals. The non-enzymatic antioxidants, vitamin C and vitamin E, also declined. Lipid peroxidation, on the other hand, significantly increased. The influence was found to be more in 100 mg treated rats when compared to 50 mg treated rats. Conclusions: The present study suggests the reproductive toxicity of aluminium by inducing the oxidative stress in the testis and epididymis and possible interference in sperm production and further maturational processes
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