In this report, we describe a copper-catalyzed cascade reaction involving oxygen radical-induced cyclization/SO insertion/fluorination of β,γ-unsaturated oximes with sulfur dioxide and Selectfluor under mild conditions for the synthesis of isoxazoline-functionalized aliphatic sulfonyl fluorides. The synthetic potential of these compounds has been evaluated through diverse SuFEx reactions.
View Article and Find Full Text PDFIn this report, we present a photocatalytic ring-opening fluorosulfonylation of strained cycloalkanols with sulfur dioxide and NFSI under mild conditions for the synthesis of carbonyl-containing aliphatic sulfonyl fluorides. The synthetic potential of the carbonyl-containing aliphatic sulfonyl fluoride products has been examined by diverse transformations, including SuFEx reactions and Baeyer-Villiger oxidation reactions. Mechanistic studies demonstrate that the reaction operates through a radical C-C bond cleavage/SO insertion/fluorination cascade process.
View Article and Find Full Text PDFAn efficient aminofluorosulfonylation strategy was developed for the synthesis of various pyrazoline-functionalized aliphatic sulfonyl fluorides using -unsaturated hydrazones with sulfur dioxide and NFSI as the starting materials under mild conditions. The sulfonyl fluoride products could be successfully transformed into the corresponding sulfonate esters and amides via the sulfur(VI) fluoride exchange (SuFEx) click reactions. Preliminary mechanistic investigations demonstrate that the reaction operates through a radical cyclization/SO insertion/fluorination cascade process.
View Article and Find Full Text PDFWe present a facile switchable regioselective 7- or 6- iodocyclization of -homoallyl benzimidates here, which affords various iodo-substituted 1,3-oxazines and tetrahydro-1,3-oxazepines in a controllable manner. The products can further undergo substitution reactions to afford a series of rich functionalized target heterocyclic molecules. The developed protocol has the advantages of mild conditions, simple operation, and excellent functional group compatibility.
View Article and Find Full Text PDFAmines, especially those with multi-nitrogen moieties, are widespread in natural products and biologically active compounds. Thus, the development of direct and efficient methods to introduce multiple nitrogen-containing fragments into compounds in one step is highly desirable yet challenging. Herein, we report an NIS-promoted selective amino-diazidation and amino-iodoazidation of -homoallyl benzimidates with NaN.
View Article and Find Full Text PDFOur previous study revealed that the bone anabolic effects of the lignan-rich fraction (SWCA) from Hance was involved in modulating the metabolism of tryptophan in vivo and inhibiting serotonin (5-HT) synthesis in vitro. This study aimed to determine how SWCA modulates bone metabolism via serotonin in vivo. The effects of SWCA were evaluated by using 4-month-old Sprague-Dawley (SD) ovariectomized rats.
View Article and Find Full Text PDFMeteorological factors have been confirmed to affect the COVID-19 transmission, but current studied conclusions varied greatly. The underlying causes of the variance remain unclear. Here, we proposed two scientific questions: (1) whether meteorological factors have a consistent influence on virus transmission after combining all the data from the studies; (2) whether the impact of meteorological factors on the COVID-19 transmission can be influenced by season, geospatial scale and latitude.
View Article and Find Full Text PDFThe hydrodynamics and environmental factors in the Xiangxi River (XXR) and Shennong River (SNR), which are tributaries of the Three Gorges Reservoir (TGR), were monitored from July to August (the low water level period) and in October (the impoundment period) in 2018. The vertical distribution characteristics of chlorophyll a and other indicators of the two tributaries were analyzed during the different operation periods, and the factors that affected the vertical distribution in each period were discussed. The results showed that the vertical distribution of dissolved oxygen, water temperature, pH value, and chlorophyll a of the XXR and SNR during the low water level period was relatively consistent.
View Article and Find Full Text PDFPremature ovarian failure (POF) is defined as deployment of amenorrhea due to the cessation of ovarian function in a woman younger than 40 years old. The pathologic mechanism of POF is not yet well understood, although genetic aberrations, autoimmune damage, and environmental factors have been identified. The current study demonstrated that NF-κB inactivation is closely associated with the development of POF based on the data from literature and cyclophosphamide (Cytoxan)-induced POF mouse model.
View Article and Find Full Text PDFA practical electrophilic aminoselenation of -homoallyl benzimidate with diselenides promoted by PhICl/CuO has been developed. The easily available and stable diselenides were used as selenium sources. Various selenyl 1,3-oxazines, which are important frameworks in medicinal and biological chemistry, were easily obtained in moderate to good yields for the first time.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
September 2021
Crude oil may block soil pores, affect soil water repellency, and change soil water movement. In this study, soil column simulation was used to study the effects of different crude oil pollution levels (0, 0.5%, 1%, 2%, 4%) on the water infiltration processes in loessial soil and aeolian sandy soil.
View Article and Find Full Text PDFA 33-year-old woman of giant broad ligament leiomyoma with myxoid degeneration was misdiagnosed as ovarian tumor. The patient underwent a transabdominal myomectomy and developed a pelvic infection after operation diagnosed with contrast-enhanced ultrasound. She was cured and ultimately discharged after symptomatic treatment.
View Article and Find Full Text PDFA facile copper-catalyzed aminosulfonylation of homoallyl benzimidates with sodium sulfinates in the presence of -butyl peroxybenzoate (TBPB) and XPhos ligand has been developed. By using this protocol, a variety of potentially bioactive 1,3-oxazines were directly synthesized. This method has the merits of a cheap catalyst, easily available and stable sulfone reagents, and simple operation.
View Article and Find Full Text PDFMenopausal women are susceptible to have high risk of cardiovascular diseases, type II diabetes and osteoporosis due to the metabolic disorder caused by estrogen deficiency. Accumulating evidence supports that gut microbiota is a key regulator of metabolic diseases. Our previous metabolomics study interestingly demonstrated that the anti-osteoporotic effects of lignan-rich fraction (SWCA) from Sambucus wialliamsii Hance were related to the restoration of a series of lipid and glucose metabolites.
View Article and Find Full Text PDFA comparative analysis of phosphate occurrence and its genesis during different dispatching periods of representative level I tributaries of the Three Gorges Reservoir was conducted. For this, water quality, hydrodynamic force, and environmental data were examined for backwater areas of the Xiangxi River and Shennong River during the low-water-level period (June), storage period (September) and high-water-level period (December) in 2018. The results suggest that the mass concentration of total phosphorus (TP) in the water body of the coves of Xiangxi River and Shennong River range from 0.
View Article and Find Full Text PDFObjectives: An artificial intelligence model was adopted to identify mild COVID-19 pneumonia from computed tomography (CT) volumes, and its diagnostic performance was then evaluated.
Methods: In this retrospective multicenter study, an atrous convolution-based deep learning model was established for the computer-assisted diagnosis of mild COVID-19 pneumonia. The dataset included 2087 chest CT exams collected from four hospitals between 1 January 2019 and 31 May 2020.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao
February 2021
Remitting seronegative symmetrical synovitis with pitting edema(RS3PE),the inflammatory arthritis attacking mainly elderly males,is characterized by symmetrical synovitis with pitting edema of the dorsum of hands and feet and the absence of rheumatoid factor.RS3PE commonly accompanies malignant tumor,infections and other diseases.Here we report a case of RS3PE associated with lung malignancy and review other six cases to summarize the clinical features,treatment and prognosis.
View Article and Find Full Text PDFA highly efficient electrophilic oxyselenation of propargylic amines with diselenides and CO under atmospheric pressure promoted by copper/DTBP is reported. Various biologically important selenyl 2-oxazolidinones were produced in moderate to excellent yields. The developed method features a broad substrate scope, easy scalability, and mild reaction conditions.
View Article and Find Full Text PDFThe water quality of the backwater areas in the Xiangxi River and Shennong River, which are typical tributaries of the Three Gorges Reservoir, was monitored in September 2018. The vertical distribution characteristics of dissolved oxygen, chlorophyll a, and other indicators in the two rivers were analyzed and compared, and the environmental factors affecting their vertical distribution were discussed. The results showed that the dissolved oxygen concentration 0-10 m and 0-12 m from the surface of the Xiangxi River and Shennong River, respectively, showed significant stratification and decreased with increasing water depth.
View Article and Find Full Text PDFAn incident of sartan medicine contamination was notified by Europe in June 2018. The contaminant was identified as a probable carcinogenic nitrosamine and the recalls of sartan medicines were soon made. Since then, more nitrosamine contaminants in sartan medicines were reported.
View Article and Find Full Text PDFA dearomative tandem spiro-cyclization reaction of -[(1-indol-3-yl)methyl]methacrylamide derivatives with sulfinate sodium in the presence of AgNO and KCO is reported, which produced sulfonylated spiro[indole-3,3'-pyrrolidines] in medium to excellent yields. The characteristics of this transformation contain good functional group tolerance and ease of operation.
View Article and Find Full Text PDFZinc finger E-box binding homeobox 1 (ZEB1), as a typical transcription inhibitory factor of E-cadherin, plays a major role in stimulating the invasion and metastasis of tumors via modulating the epithelial-mesenchymal transition (EMT) signal. However, its function and modulatory mechanisms in endometrial carcinoma (EC) remain unclear. In this study, silencing ZEB1 significantly reduced EC cell migration, invasion, and metastasis, as well as enhanced the sensitivity of EC cells to cisplatin (cDDP) in vitro and in vivo.
View Article and Find Full Text PDFBackground: The optimal lymphadenectomy for gastric cancer (GC) with pyloric invasion is controversial because the pattern of lymph node metastasis is different from that of distal GC. The rate of lymph node metastasis into the posterior area of the pancreatic head and hepatoduodenal ligament is high. This study evaluated the estimated benefit of radical gastrectomy with D2-plus lymphadenectomy in patients with pyloric invasion.
View Article and Find Full Text PDFLiver fibrosis is a very common condition seen in millions of patients with various liver diseases, and yet no effective treatments are available owing to poorly characterized molecular pathogenesis. Here, we show that leukocyte cell-derived chemotaxin 2 (LECT2) is a functional ligand of Tie1, a poorly characterized endothelial cell (EC)-specific orphan receptor. Upon binding to Tie1, LECT2 interrupts Tie1/Tie2 heterodimerization, facilitates Tie2/Tie2 homodimerization, activates PPAR signaling, and inhibits the migration and tube formations of EC.
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