Publications by authors named "Han-Xiao Li"

Under mild conditions and without the need of inert gas protection, a Rh-catalyzed rearrangement of -divinylcyclopropanes to form 1,5-disubstituted 1,4-cycloheptadienes has been developed and is disclosed here. This reaction can expedite the synthesis of challenging seven-membered carbocycles.

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Aim: To investigate the morphological characteristics of retinal vessels in patients with different severity of diabetic retinopathy (DR) and in patients with or without diabetic macular edema (DME).

Methods: The 239 eyes of DR patients and 100 eyes of healthy individuals were recruited for the study. The severity of DR patients was graded as mild, moderate and severe non-proliferative diabetic retinopathy (NPDR) according to the international clinical diabetic retinopathy (ICDR) disease severity scale classification, and retinal vascular morphology was quantitatively analyzed in ultra-wide field images using RU-net and transfer learning methods.

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Current methods for arene hydrogenation generally need either harsh reaction conditions or complex catalyst preparation. Here we describe a mild and convenient protocol that only utilizes commercially available catalysts. Using [Rh(nbd)Cl] and Pd/C together as catalysts, arenes bearing various functional groups can be hydrogenated under 1 atm of H at room temperature.

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Transition-metal-catalyzed [4 + 1] reaction of dienes and carbon monoxide (CO) is the most straightforward and easily envisioned cyclization for the synthesis of five-membered carbocycles, which are ubiquitously found in natural products and functional molecules. Unfortunately, no test of this reaction was reported, and consequently, chemists do not know whether such kind of reaction works or not. Herein, we report that the [4 + 1] reaction of common dienes and CO cannot work, at least under the catalysis of [Rh(cod)Cl].

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An efficient approach to access functionalized indole derivatives has been developed through Cu(OTf)-catalyzed C3 aza-Friedel-Crafts alkylation of substituted indoles 5a-5m, -methyl-pyrrole with linear ,-acetals 4a-4l. As a result, a series of C3 amide aza-alkylated indole derivatives 6a-6ag and 7 were synthesized in moderate to excellent yields.

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The first Ni(OTf)-catalyzed hydroamination of ynamides was developed by reacting with secondary amines ( and ). This protocol features excellent regioselectivity, a broad substrate scope of secondary aryl amines, and good functional group tolerance for ynamides. Using this method, a variety of substituted ethene-1,1-diamine compounds were prepared in moderate to excellent yields with high regioselectivities.

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Article Synopsis
  • The study aimed to investigate the use of invasive cardiopulmonary exercise testing (iCPET) for diagnosing patients with unexplained shortness of breath (dyspnea).
  • A retrospective analysis was performed on 1,046 patients with exertional dyspnea, identifying causes through routine exams, right cardiac catheterization, and, if necessary, iCPET, allowing for categorization into different diagnostic groups.
  • Among 144 patients without a clear diagnosis, 47 completed the iCPET, revealing various issues like preload failure and exercise-induced heart failure, with most patients being middle-aged and disproportionately urban-dwelling.
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An efficient approach to access functionalized (2,3-dihydroisoxazol-4-yl) ketones has been developed by reacting nitrones 4 with ynones 7 or terminal ynones 10 in a one-pot fashion. The reaction went through a formal Sc(OTf)3-catalyzed [3 + 2]-cycloaddition process to generate a number of functionalized (2,3-dihydroisoxazol-4-yl) ketones 11aa-11aw, 11ba-11la and 12aa-12ae in moderate to good yields.

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An approach to access functionalized 3,4-dihydro-1,3-oxazin-2-ones has been developed by reacting semicyclic ,-acetals and with ynamides or terminal alkynes in a one-pot fashion. The reaction went through a formal [4 + 2] cycloaddition process to generate a number of functionalized 3,4-dihydro-1,3-oxazin-2-ones and in yields of 34-97%. In addition, the utility of this transformation was demonstrated by the synthesis of (±)-sedamine .

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Background: Drought is one of the most adverse environmental factors limiting crop productions and it is important to identify key genetic determinants for food safety. Calcium-dependent protein kinases (CPKs) are known to be involved in plant growth, development, and environmental stresses. However, biological functions and regulatory mechanisms of many plant CPKs have not been explored.

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The influence of reward on behavior is one of the hottest research subjects in psychological research. Reward-induced motivation promotes the performance of the participants. In the field of emotional processing, the reward can influence the individual's processing of emotional information, but previous studies have not directly discussed the effect of reward on emotional regulation.

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Background: The worsening problems of antibiotic resistance prompt the need for alternative strategies. Baicalin, which is isolated from Scutellaria baicalensisi, has been demonstrated to exhibit anti-inflammatory, anti-virulence and antimicrobial effects. Salmonella typhimurium is an important foodborne pathogenic bacteriaum that causes gastrointestinal disease in humans and many animals.

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Background: The optimal timing for initiating renal replacement therapy (RRT) in patients with acute kidney injury (AKI) remains controversial.

Methods: We conducted a meta-analysis with trial sequential analysis (TSA) of randomized controlled trials (RCTs) using PUBMED, Cochrane Library databases, and Web of Science (from January 1, 1985, to August 21, 2016). Adult patients with AKI who received RRT with different timing were included.

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The aim of the present study was to investigate the effects of bone marrow-derived mesenchymal stem cells (BMSCs) transfected with survivin on lung fibrosis in mice. Mice with bleomycin-induced pulmonary fibrosis were allocated at random to group A, B or C, and injected with 1×10 survivin gene-expressing BMSCs, 1×10 BMSCs or normal saline, respectively. A total of 6 mice were sacrificed from each group on days 7, 14 and 28 after treatment.

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Objective: To analyze the residues of heavy metals in Chinese crude drugs.

Method: The SPSS 13.0 software was used to analyze the data of Cu, Pb, As, Cd, Hg collected in literatures.

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