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11.
Sandeep Chaudhary Bharti Rajesh K. Shyamlal Lalit Yadav Mohit K. Tiwari Krishan Kumar 《RSC advances》2018,8(41):23152
Herein, we disclose the first example of an efficient, silver oxide nanoparticle-catalyzed, direct regioselective synthesis of 3-ylidenephthalides 11–16 and isocoumarins 17–20via sonogashira type coupling followed by substrate-controlled 5-exo-dig or 6-endo-dig cyclization reaction, respectively. This one pot coupling involves reaction of substituted 2-halobenzoic acid with meta/para-substituted and ortho-substituted terminal alkynes, which proceeded in a regioselective manner resulting in the formation of 3-ylidenephthalides or isocoumarins, respectively, in excellent yields (up to 95%) with complete Z-selectivity. This protocol features relatively broad substrate scope, mild conditions, operational simplicity, and is favourable with aromatic/alicyclic terminal alkynes. The competition experiments and gram-scale synthesis further highlight the importance and versatility of the methodology. The proposed mechanistic pathways illustrate that the regioselectivity is substantially being controlled by the substituent(s) present on the acetylenic phenyl ring.We report the first example of an efficient, Ag2O nanoparticle-catalyzed, direct regioselective synthesis of 3-ylidenephthalides and isocoumarins via Sonogashira type coupling followed by substrate-controlled 5-exo-dig or 6-endo-dig cyclization reaction, respectively. 相似文献
12.
Intrahepatic portal venopathy leads to various entities that are important causes of portal hypertension. Noncirrhotic portal fibrosis (NCPF) occurs in the Indian subcontinent, whereas idiopathic portal hypertension (IPH) occurs in Japan although the pathogenesis and presentation of both are similar. NCPF presents mainly with upper gastrointestinal bleeding; IPH presents with massive splenomegaly. The liver functions are preserved. Wedged hepatic venous pressure is normal, but portal venous pressure is high indicating a presinusoidal block. Patients are best managed with endoscopic therapy or surgery, with better results than in patients with cirrhosis. Nodular regenerative hyperplasia is a histological diagnosis characterized by development of nodules in the liver due to uneven perfusion of the portal venous blood. These patients may develop portal hypertension and if they bleed would require treatment as in NCPF/IPH. Schistosomiasis produces portal hypertension by the development of fibrous tissue around the portal veins as a response to schistosome eggs. Gratifying results have been reported with praziquantel therapy. Rarely sarcoidosis and chronic biliary obstruction may also produce portal venopathy. 相似文献
13.
Gupta Manisha Krishan Pawan Kaur Amarjot Arora Sandeep Trehanpati Nirupma Singh Thakur Gurjeet Bedi Onkar 《Inflammation research》2021,70(7):765-776
Inflammation Research - Non-alcoholic fatty liver disease (NAFLD) is a multifaceted disease allied with various metabolic disorders, obesity and dysbiosis. Gut microbiota plays an influential role... 相似文献
14.
Geeta Ram John Chen Krishan Kumar Hope F. Ross Carles Ubeda Priyadarshan K. Damle Kristin D. Lane José R. Penadés Gail E. Christie Richard P. Novick 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(40):16300-16305
Staphylococcal pathogenicity islands (SaPIs) carry superantigen and resistance genes and are extremely widespread in Staphylococcus aureus and in other Gram-positive bacteria. SaPIs represent a major source of intrageneric horizontal gene transfer and a stealth conduit for intergeneric gene transfer; they are phage satellites that exploit the life cycle of their temperate helper phages with elegant precision to enable their rapid replication and promiscuous spread. SaPIs also interfere with helper phage reproduction, blocking plaque formation, sharply reducing burst size and enhancing the survival of host cells following phage infection. Here, we show that SaPIs use several different strategies for phage interference, presumably the result of convergent evolution. One strategy, not described previously in the bacteriophage microcosm, involves a SaPI-encoded protein that directly and specifically interferes with phage DNA packaging by blocking the phage terminase small subunit. Another strategy involves interference with phage reproduction by diversion of the vast majority of virion proteins to the formation of SaPI-specific small infectious particles. Several SaPIs use both of these strategies, and at least one uses neither but possesses a third. Our studies illuminate a key feature of the evolutionary strategy of these mobile genetic elements, in addition to their carriage of important genes—interference with helper phage reproduction, which could ensure their transferability and long-term persistence. 相似文献
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16.
Tacrolimus combined with corticosteroids versus Modified Ponticelli regimen in treatment of idiopathic membranous nephropathy: Randomized control trial 下载免费PDF全文
17.
Kumar A Kumar K Korde R Puri SK Malhotra P Singh Chauhan V 《Infection and immunity》2007,75(4):2026-2034
Cysteine proteases (falcipains) of Plasmodium falciparum are potential targets for antimalarial chemotherapy, since they have been shown to be involved in important cellular functions such as hemoglobin degradation and invasion/rupture of red blood cells during parasite life cycle. The role of falcipain-1 at the asexual blood stages of the parasite still remains uncertain. This is mainly due to a lack of methods to prepare this protein in an active form. In order to obtain biologically active falcipain-1, a number of falcipain-1 constructs were designed and a systematic assessment of the refolding conditions was done. We describe here the expression, purification, and characterization of a falcipain-1 construct encoding mature falcipain-1 and 35 amino acids from the C-terminal of the pro domain. Recombinant falcipain-1 was overexpressed in the form of inclusion bodies, solubilized, and purified by Ni2+-nitrilotriacetic acid affinity chromatography under denaturing conditions. A systemic approach was then followed to optimize refolding parameters. An optimum refolding condition was obtained, and the yield of the purified refolded falcipain-1 was ~1 mg/liter. Activity of the protein was analyzed by fluorometric and gelatin degradation assays. Immunolocalization studies using anti-falcipain-1 sera revealed a distinct staining at the apical end of the P. falciparum merozoites. Previous studies using falcipain-1-specific inhibitors have suggested a role of falcipain-1 in merozoite invasion. Based on its localization and its role in invasion, we analyzed the immunogenicity of falcipain-1 in mice, followed by heterologous challenge with Plasmodium yoelii sporozoites. Our results suggest a possible role of falcipain-1 in merozoite invasion. 相似文献
18.
Alexander A. Boucher Leah Rosenfeldt Duaa Mureb Jessica Shafer Bal Krishan Sharma Adam Lane Rebecca R. Crowther Melanie C. McKell Jordan Whitt Theresa Alenghat Joseph Qualls Silvio Antoniak Nigel Mackman Matthew J. Flick Kris A. Steinbrecher Joseph S. Palumbo 《Journal of thrombosis and haemostasis》2020,18(1):91-103
19.
20.
Mithila Vanarase Ram Krishan Gautam Pooja Arora Sonali Bajaj Neha Meena Ananta Khurana 《Journal of cosmetic and laser therapy》2017,19(5):259-265
Background: Q-switched lasers are conventionally used for the treatment of black tattoo. However, they require multiple sittings, and the response may be slow due to competing epidermal pigment in dark skin. Objective: To compare the efficacy of Q-switched Nd:YAG laser alone with its combination with ultrapulse CO2 for the removal of black tattoo. Materials and methods: Sixty patients with black tattoo were randomized into two groups viz., group A and group B. Group A was treated with QS Nd:YAG laser (1064 nm) alone, and group B received combination of ablative ultrapulse CO2 followed by fixed-dose QS Nd:YAG laser (1064 nm), at 6-week interval for a maximum of 6 sittings. After each sitting, 3 independent physicians noted percentage of improvement that was evaluated using visual analogue scale (VAS) and grading system for tattoo ink lightening (TIL). Results: Combination laser (group B) showed statistically significant improvement in mean VAS score in the last 2 noted visits as compared to 1st session (p < 0.007, p < 0.001) and TIL mean score in last three noted visits as compared to 1st session (p < 0.008, p < 0.020, and p < 0.004). There was no statistically significant difference in the side effect profile of both the groups. Conclusion: For refractory professional tattoos, combination of ultrapulse CO2 laser and QS Nd:YAG laser is superior to QS Nd:YAG laser alone. 相似文献