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•The unique one-step synthesis of carbonyl dibenzofurans was developed.•It involves decarboxylative CH arylation and carbonylative CC coupling.•The reaction is highly chemo- and ...regio-selective and environment friendly.•Reusable nanodomain cuprous oxide was used as catalyst under aerobic condition.•Several derivatives were synthesized which showed high functional group tolerance.
Consecutive chemo- and regio-selective decarboxylative CH arylation, followed by carbonylative CC coupling of aryl halide with isocyanide/alcohol was applied for the first time in one-step synthesis of carbonyl dibenzofurans with nanodomain cuprous oxide under aerobic condition. As a proof of concept, several novel dibenzofurans were synthesized from 2-(3-iodophenoxy)benzoic acid in good yield. The tandem protocol eliminates the use of excess catalysts, hazardous organic solvents, heavy metals like palladium or rhodium, ligands, oxidants, or external additives. More importantly, the cubic Cu(I) nanocatalyst can be recovered and recycled for three consecutive reactions without any significant loss of catalytic activity or any change in its morphology. Use of water as solvent and reusable catalyst makes the reaction environment friendly.
Wound healing management is a major challenge for critical full-thickness skin wounds. Development of nanofibrous scaffolds with tunable wettability, degradation, and biocompatibility are highly ...desirable. Herein, we demonstrated synthesis of oleoyl chitosan (OC) by grafting monounsaturated fatty acid residue, C18 oleoyl chain, to the backbone of chitosan molecule and blending with gelatin to form the nanofiber mats. The physicochemical properties of the nanofiber mats revealed mechanical strength, moderate surface wettability, and suitable degradation rate. The nanofibrous mats showed excellent in vitro cytocompatibility with human amniotic membrane-derived stem cells (HAMSCs) in terms of enhanced adhesion and proliferation owing to biomimetic nanoarchitecture and chemical cues. Furthermore, the fabricated nanofiber was implanted with and without preseeded HAMSCs in the full-thickness wound to evaluate the skin wound healing efficacy in a rat model. Histological and immunohistochemical studies were conducted to evaluate the plausible changes of tissue architecture and expression of molecular markers involved in wound healing process. Both acellular and HAMSCs incorporated cellular nanofibers promoted wound contraction remarkably with superior skin tissue regeneration in terms of enhanced collagen synthesis, re-epithelialization and initiation of epithelial cells stratification compared to control group.
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•Nafion membrane incorporated with AgNPs is used as a test strip for H2O2.•AgNPs with good optical quality are synthesised by novel ascorbic acid reduction.•The strip is highly ...selective for H2O2 with excellent percentage recovery.•The strip is successfully employed for quantitative detection of H2O2 in milk.•The mechanism of detection is explored and an Oxidative Sawing Model is proposed.
We report the preparation of an optical test strip for quantitative assay of hydrogen peroxide (H2O2) in aqueous solution. Silver nanoparticles(AgNPs) with good optical quality are synthesized by in-situ reduction of silver ions in Nafion-117 membrane previously absorbed with ascorbate ion (HA−). The nanocomposite membrane exhibits a narrow Localized Surface Plasmon Resonance (LSPR) band at 413nm. The extent of decrease in intensity of the LSPR band in presence of H2O2 solution gives quantitative estimate of H2O2 concentration. The detector has been found to show a good analytical response towards H2O2 detection at pH 7 over a wide concentration range. The detection limit has been calculated to be 2.6×10−8molL−1, which is lower than the conventional enzyme based biosensors. The present test strip has been succesfully employed for the quantitative assay of H2O2 in milk. The mechanism of change in LSPR in presence of H2O2 (1.0×10−3molL−1) has been explored for the first time using time resolved Small-Angle X-ray Scattering and radiotracer techniques. The results show that at this concentration of H2O2, its sharp oxidative sawing action is responsible for cutting off the nanoparticles into smaller fragments resulting in rapid reduction of absorption crossection.
Two novel boron-tolerant, arsenic-resistant, Gram-positive bacterial strains,
sp. OL1 and
sp. OL5, were isolated from boron fertilizer-amended cauliflower plantation field soils in India. Here, we ...report the draft genome sequences of OL1 (4.87 Mb) and OL5 (3.93 Mb) to explore the intricacies of boron tolerance in bacteria.
Deals and Development Pritchett, Lant; Sen, Kunal; Werker, Eric
2017, 2017-11-16, 2018, 2017-11-03
eBook
Odprti dostop
"International financial crises have plagued the world in recent decades, including the Latin American debt crisis of the 1980s, the East Asian crisis of the late twentieth century, and the global ...financial crisis of 2007-09. One of the basic problems faced during these crises is the lack of adequate preventive mechanisms, as well as insufficient instruments to finance countries in crisis and to overcome their over-indebtedness. Resetting the International Monetary (Non)System provides an analysis of the global monetary system and the necessary reforms that it should undergo to play an active role in the twenty-first century and proposes a comprehensive yet evolutionary reform of the system. Criticising the ad hoc framework- a ""(non)system""- that has evolved following the breakdown of the Bretton Woods arrangement in the early 1970's, Resetting the International Monetary (Non)System places a special focus on the asymmetries that emerging and developing countries face, analysing the controversial management of crises by the International Monetary Fund and proposing a consistent set of reform proposals to design a better system of international monetary cooperation. Policy orientated and structured to deal in a sequential way with the issues involved, it suggests provision of international liquidity through a system that mixes the multicurrency arrangement with a more active use of the IMF's Special Drawing Rights; stronger mechanisms of macroeconomic policy cooperation, including greater cooperation in exchange rate management and freedom to manage capital flows; additional automatic balance-of-payments financing facilities and the complementary use of swap and regional arrangements; a multilateral sovereign debt workout mechanism; and major reforms of the system's governance."
Assembled diglycolamides (DGAs) have a strong affinity toward f-element ions at high nitric acid concentrations. Small angle X-ray scattering studies revealed that nitric acid concentration dependent ...changes occur in the geometrical arrangement of the DGA units of monomeric methacryloyl-DGA and the corresponding polymeric DGA. Cylindrical aggregates of methacryloyl-DGA were formed in 10:1 n-dodecane:1-decanol (added for solubility reasons) upon equilibration with nitric acid. The lengths and diameters of the cylindrical methacryloyl-DGA aggregates increased on varying the nitric acid concentration from 3 to 4 mol L–1. This resulted in an increase of the distribution coefficient (D) of Eu3+ ions from 72 to 197. The physical structure of cross-linked (10 mol %) poly(methacryloyl-DGA) reorganized distinctly upon equilibration with nitric acid. In this case, also the D Eu3+ values increased significantly from 147 mL g–1 at 1 mol L–1 HNO3 to ∼4000 mL g–1 at 4 mol L–1 HNO3. Hydrogen bonds between the outer sphere of Eu3+/Am3+/Pu4+ nitrate and DGA units provide stabilization in the hydrophobic environment. This results in enhancement of their extraction upon increasing nitric acid concentration both in the organic phase as well as in the polymer matrix. Though monomeric and polymeric methacryloyl-DGA are different in their physical assembling, the normalized D I values for a same f-element ion upon varying HNO3 concentrations show remarkably similar patterns in both forms. In addition, the unusual stoichiometry deduced from the slopes of the log D vs logHNO3 curves at fixed nitrate concentration seems to suggest that the normal extraction mechanism may not be operating in the hydrogen bonded DGA assemblies.
Comprehensive Wound Center, Davis Heart and Lung Research Institute, Departments of Surgery
2 Departments of Veterinary Preventive Medicine, The Ohio State University Medical Center, Columbus, Ohio
3 ...Departments of Internal Medicine, The Ohio State University Medical Center, Columbus, Ohio
4 Department of Surgery, University of Texas Medical Branch, Galveston, Texas
Chronic ischemic wounds presenting at wound clinics are heterogeneous with respect to etiology, age of the wound, and other factors complicating wound healing. In addition, there are ethical challenges associated with collecting repeated biopsies from a patient to develop an understanding of the temporal dynamics of the mechanisms underlying chronic wounds. The need for a preclinical model of ischemic wound is therefore compelling. The porcine model is widely accepted as an excellent preclinical model for human wounds. A full-thickness bipedicle flap approach was adopted to cause skin ischemia. Closure of excisional wounds placed on ischemic tissue was severely impaired resulting in chronic wounds. Histologically, ischemic wounds suffered from impaired re-epithelialization, delayed macrophage recruitment and poorer endothelial cell abundance and organization. Compared with the pair-matched nonischemic wound, unique aspects of the ischemic wound biology were examined on days 3, 7, 14 , and 28 by systematic screening of the wound tissue transcriptome using high-density porcine GeneChips. Ischemia markedly potentiated the expression of arginase-1, a cytosolic enzyme that metabolizes the precursor of nitric oxide L -arginine. Ischemia also induced the SOD2 in the wound tissue perhaps as survival response of the challenged tissue. Human chronic wounds also demonstrated elevated expression of SOD2 and arginase-1. This study provides a thorough database that may serve as a valuable reference tool to develop novel hypotheses aiming to elucidate the biology of ischemic chronic wounds in a preclinical setting.
oxygen; porcine; swine; microarray
Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are the most Severe Cutaneous Adverse Reactions (SCARs) which mainly caused by exposure to drugs and having significant morbidity ...and mortality. TEN represents an immunologic reaction to a foreign antigen and is most often caused by drugs. Nevirapine (NVP), a non-nucleoside reverse transcriptase inhibitor (NNRTI) is an important component of Highly Active Antiretroviral Therapy (HAART). It is sometimes associated with life-threatening adverse reactions. Here, we report the fatal case of 72-year-old male who developed TEN secondary to intake of nevirapine. This fatal case report will increase awareness among treating physicians for careful monitoring of patients on NNRTI-based antiretroviral therapy and better counseling of the patient on NVP regimen for early identification and reporting of SCARs so that fatalities due to adverse drug reactions can be prevented with timely intervention.
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