The first direct and selective 3,6‐di‐thiolation and 3,6‐di‐selenylation of carbazoles using diaryl disulfides/diselenide as the sulfur/selenium source were demonstrated. This simple, general, and ...efficient method could deliver a wide range of 3,6‐di‐sulfenyl‐carbazoles and 3,6‐di‐selenyl‐carbazoles from readily available starting materials with high regioselectivity in an easily‐operated one‐step reaction via a Ag/K2S2O8‐mediated protocol.
The first synthesis of 3,6‐di‐sulfenyl‐carbazoles and 3,6‐di‐selenyl‐carbazoles was successfully achieved in a simple and efficient one‐step reaction.
We report an iron‐catalyzed divergent synthesis of alkylated indoles based on precise control of the activation sites on indoles through the selection of catalysts. Using indoles and styrenes as ...starting materials, 3,5‐di‐alkylated indoles could be prepared selectively and directly for the first time by treating with a catalytic amount of Fe(OTf)3 and 3‐alkylated indoles were achieved exclusively by adding a catalytic amount of γ‐cyclodextrin as the cocatalyst with Fe(OTf)3. This simple method was demonstrated with 52 examples with high yields and broad functional group compatibilities.
A general, efficient and regioselective protocol has been developed for the synthesis of trifluoromethylated bis(carbazolyl)methanes. This metal‐free transformation proceeds smoothly under air ...atmosphere and features broad scope for both reaction partners. This method could also be extended to the synthesis of difluoromethylated and chlorodifluoromethylated bis(carbazolyl)methanes.
Abstract
The first direct and selective 3,6‐di‐thiolation and 3,6‐di‐selenylation of carbazoles using diaryl disulfides/diselenide as the sulfur/selenium source were demonstrated. This simple, ...general, and efficient method could deliver a wide range of 3,6‐di‐sulfenyl‐carbazoles and 3,6‐di‐selenyl‐carbazoles from readily available starting materials with high regioselectivity in an easily‐operated one‐step reaction via a Ag/K
2
S
2
O
8
‐mediated protocol.
The first direct and selective 3,6-di-alkylation of carbazoles
via
iron-catalyzed hydroarylation of styrenes is demonstrated. This simple, general and efficient method could deliver a wide range of ...di-benzyl-carbazoles with high chemo- and regio-selectivity at room temperature in up to 96% yield with no need for a noble-metal catalyst, directing group or additives.
The first direct and selective C position di-alkylation of carbazoles
via
iron-catalyzed hydroarylation of styrenes was developed.
COVID-19 is a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early reported symptoms include fever, cough, and respiratory symptoms. There were few reports of ...digestive symptoms. However, with COVID-19 spreading worldwide, symptoms such as vomiting, diarrhoea, and abdominal pain have gained increasing attention. Research has found that angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 receptor, is strongly expressed in the gastrointestinal tract and liver. Whether theoretically or clinically, many studies have suggested a close connection between COVID-19 and the digestive system. In this review, we summarize the digestive symptoms reported in existing research, discuss the impact of SARS-CoV-2 on the gastrointestinal tract and liver, and determine the possible mechanisms and aetiology, such as cytokine storm. In-depth exploration of the relationship between COVID-19 and the digestive system is urgently needed.
With the avalanche of biological sequences in public databases, one of the most challenging problems in computational biology is to predict their biological functions and cellular attributes. Most of ...the existing prediction algorithms can only handle fixed-length numerical vectors. Therefore, it is important to be able to represent biological sequences with various lengths using fixed-length numerical vectors. Although several algorithms, as well as software implementations, have been developed to address this problem, these existing programs can only provide a fixed number of representation modes. Every time a new sequence representation mode is developed, a new program will be needed. In this paper, we propose the UltraPse as a universal software platform for this problem. The function of the UltraPse is not only to generate various existing sequence representation modes, but also to simplify all future programming works in developing novel representation modes. The extensibility of UltraPse is particularly enhanced. It allows the users to define their own representation mode, their own physicochemical properties, or even their own types of biological sequences. Moreover, UltraPse is also the fastest software of its kind. The source code package, as well as the executables for both Linux and Windows platforms, can be downloaded from the GitHub repository.
Osteoporosis or osteopenia is a common complication in patients with cirrhosis, but little is known about the risk factors for the occurrence of osteoporosis.Patients with liver cirrhosis due to ...chronic virus infection and alcoholic abuse were enrolled. Bone mineral density (BMD) was determined using dual-energy x-ray absorptiometry (DXA). Osteoporosis was diagnosed according to WHO criteria. The severity of liver stiffness was measured by Fibroscan. Demographic data, such as age, gender, weight, height, and body mass index (BMI), were collected. Logistic regression analysis was used to recognize the risk factors of osteoporosis in patients with cirrhosis.A total of 446 patients were included in this study: 217 had liver cirrhosis (male, 74.2%; mean age, 57.2 ± 10.27) and 229 were matched controls (male, 69%, mean age, 56.69 ± 9.37). Osteoporosis was found in 44 patients (44/217, 20.3%). The spine and hip BMD in cirrhotic patients were significantly lower than that in controls. When the cirrhotic and control subjects were stratified by age, gender, and BMI, the significant difference was also observed in women patients, patients older than 60, and patients with BMI < 18. Multivariate analysis showed that the older age odds ratio (OR) = 1.78, P = .046, lower BMI (OR = 0.63, P = .049), greater fibroscan score (OR = 1.15, P = .009), and liver cirrhosis induced by alcohol liver disease (OR = 3.42, P < .001) were independently associated with osteoporosis in cirrhotic patients.Osteoporosis occurred in about one-fifth of patients with liver cirrhosis, which was associated with age, BMI, Fibroscan score, and alcohol liver disease related liver cirrhosis.
BACKGROUND Leptocarpin (LTC) has drawn much attention for suppressing tumor growth or reducing inflammation. However, the effect of LTC on osteosarcoma has rarely been reported. Our object was to ...determine whether LTC suppresses MG63 cell proliferation, migration, and invasion, and whether type-1 insulin-like growth factor receptor (IGF-1R) is one of the targets in LTC suppressing osteosarcoma. MATERIAL AND METHODS Cytotoxicity of LTC was performed by use of a cell-counting kit-8 (CCK-8). RNA interference (RNAi) or pEABE-bleo IGF-1R plasmid were used for silencing or overexpressing IGF-1R, Western blot (WB) analysis was used for IGF-1R expression, CCK-8 for proliferation, and transwell assay for migration and invasion. RESULTS LTC (23.533 μM) treatment for 48 h was taken as the 50% inhibiting concentration (IC50), which significantly (P<0.05) suppressed MG63 cells proliferation, migration, and invasion. LTC (IC50) obviously inhibited IGF-1R expression in MG63 cells, with similar effect to small interfering RNA (siRNA), while pEABE-bleo IGF-1R transfection overexpressed IGF-1R. siRNA silencing IGF-1R suppressed MG63 cells proliferation, migration, and invasion, while pEABE-bleo IGF-1R transfection was significantly (P<0.05) promoted. With or without siRNA or pEABE-bleo IGF-1R transfection, LTC (IC50) suppressed MG63 cells proliferation, migration, and invasion. The effect of LTC (IC50) combined with siRNA on suppressing MG63 cells proliferation, migration, and invasion was more obvious, while the effect of LTC (IC50) combined with pEABE-bleo IGF-1R transfection was less significant (P<0.05). CONCLUSIONS LTC suppressed osteosarcoma proliferation, migration, and invasion by inhibiting IGF-1R expression. IGF-1R is one of the targets in LTC suppressing osteosarcoma.
In December 2019, pneumonia of unknown cause broke out, and currently more than 150 countries around the world have been affected. Globally, as of 5: 46 pm CET, 6 November 2020, the World Health ...Organization (WHO) had reported 48 534 508 confirmed cases of COVID-19, including 1 231 017 deaths. The novel coronavirus disease (COVID-19) outbreak, caused by the SARS-CoV-2 virus, is the most important medical challenge in decades. Previous research mainly focused on the exploration of lung changes. However, with development of the disease and deepening research, more and more patients showed cardiovascular diseases, even in those without respiratory symptoms, and some researchers have found that underlying cardiovascular diseases increase the risk of infection. Although the related mechanism is not thoroughly studied, based on existing research, we speculate that the interaction between the virus and its receptor, inflammatory factors, various forms of the stress response, hypoxic environment, and drug administration could all induce the development of cardiac adverse events. Interventions to control these pathogenic factors may effectively reduce the occurrence of cardiovascular complications. This review summarizes the latest research on the relationship between COVID-19 and its associated cardiovascular complications, and we also explore possible mechanisms and treatments.
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