Search

A new Ru-catalyzed C–H activation/cyclization reaction for the synthesis of 3-C-glycosyl isocoumarins and 2-glycosyl-4H-chromen-4-ones with carbonyl sulfoxonium ylide glycogen are reported. In this catalytic system, benzoic acid and its derivatives react with carbonyl sulfoxonium ylide glycogen to yield isocoumarin C-glycosides, while 2-hydroxybenzaldehyde substrates react to produce chromone C-glycosides. These reactions were characterized by mild reaction conditions, broad substrate scope, high functional-group compatibility, and high stereoselectivity to yield several high-value isocoumarins and chromone skeleton-containing C-glycosides. The methods were successfully implemented in the context of large-scale reactions and the late-stage modification of complex natural products. [ABSTRACT FROM AUTHOR]

In order to gain a deeper understanding of the industry’s risk status and assist in risk decision-making, based on the acceptable risk theory, we use two “five-year plans” (“Eleventh Five-Year Plan” and “Twelfth Five-Year Plan”) as the time periods to collect accident data of coal mines. Meanwhile, acceptable risk criteria for the coal industry is established by average individual risk(AIR) value method and cumulative frequency of accident-deaths number (FN) curve method. And we research on the application of acceptable risk criteria for the coal industry: compared horizontally the risk levels of coal mine, chemical industry and other industries based on acceptable risk, analyzed the optimal safety investment in the current form of coal mine industry based on the acceptable risk-life quality index, and proposed a semi-quantitative risk assessment method for coal mine production based on acceptable risk and fuzzy AHP theory to comprehensively assess personal risks and social risks of coal mine.

The formation of phytoene by condensing two geranylgeranyl diphosphate molecules catalyzed by phytoene synthase (PSY) is the first committed and rate-limiting step in carotenoid biosynthesis, which has been extensively investigated in bacteria, land plants and microalgae. However, this step in macroalgae remains unknown. In the present study, a gene encoding putative phytoene synthase was cloned from the economic red alga Pyropia yezoensis—a species that has long been used in food and pharmaceuticals. The conservative motifs/domains and the tertiary structure predicted using bioinformatic tools suggested that the cloned PyPSY should encode a phytoene synthase; this was empirically confirmed by pigment complementation in E. coli. This phytoene synthase was encoded by a single copy gene, whose expression was presumably regulated by many factors. The phylogenetic relationship of PSYs from different organisms suggested that red algae are probably the progeny of primary endosymbiosis and plastid donors of secondary endosymbiosis. [ABSTRACT FROM AUTHOR]

Contrast-induced encephalopathy (CIEP) is a rare complication after endovascular therapy. The etiology of CIEP is still a matter of debate. We present a rare occurrence of CIEP in a known hypertensive and type 2 diabetic patient after endovascular coiling of cerebral aneurysm with oculomotor nerve palsy. A 68-year old female presented with seven days history of headache and left ptosis or blepharoptosis with mild mydriasis. The headaches were localized mainly at the left side of the nose, orbit, and upper forehead while the left ptosis was associated with blurred vision. Computed tomography angiography revealed an aneurysm in between the C4 segment of the left internal carotid artery (ICA) and the bifurcation of the left posterior communicating artery. Digital subtraction angiography further confirmed the aneurysm. We used the transarterial approach to assess the aneurysm and subsequent coiling. Iohexol (Omnipaque) contrast agent was used during the endovascular procedure. The patient’s condition deteriorated into acute confusion state with cardinal symptomology of CIEP immediately after the operation. Computed tomography scan revealed cortical contrast enhancement in the vascular territory of the ICA as well as edema. Her symptomatology resolved 48 hours after treated with anticonvulsants, intracranial pressure reduction and hydration. Chronic hypertension as well as type 2 diabetics may be critical predisposing factors to CIEP. CIEP should be suspected in patients presenting with acute confusion state after endovascular therapy. Massive edema with ischemic brain changes in white matter of the brain before endovascular procedure should rise suspicion of CIEP.

Endovascular Embolization (EVE) of aneurysms is a very effective and efficient treatment modality. Nevertheless, a few complications have been reported after EVE of aneurysms. Our study therefore evaluated the safety and efficacy of Low-profile Visible Intraluminal Support (LVIS) stentassisted EVE for intracranial Dissecting Aneurysms (DAs). We conducted a retrospective study to identify patients with DAs who were treated with LVIS stent from July 2015 to September 2018. The DAs were categoried into ruptured and unruptured. The arteries harbouring the aneurysm were identified in all cases. LVIS device stent assisted coil EVE treatment modality was utilized to treat all the patients. Surgical safety, immediate surgery outcome, recurrence rate and imaging follow-up results of all patients were analysed. The Glasgow Outcome Scale (GOS) score of all patients where assessed during discharge. Cerebral angiography of all patients were reevaluated on scheduled visits from three months up to one year after their operations. A total of Six DA patients were identified during our analysis. Four of the cases were ruptured DAs while two cases were unruptured. The DAs originated from the Internal Carotid Artery (ICA) in two cases, while in the remaining four cases, the DAs originated from vertebral artery (VA). Stents and coils were successfully implanted in all six patients. The DAs were embolized satisfactorily and the parent arteries were patent immediately after the operations. We obsereved 5 points GOS score in four cases and 4 points in two cases. No aneurysmal recurrece, no stent collapse or displacement was obsereved in all cases during follow-ups. Our study suggests that, LVIS stent-assisted EVE is simple, safe and effective in the treatment of DAs.

A meta‐analysis was performed to compare the effects of laparoscopic splenectomy (LS) and open splenectomy (OS) for splenic rupture on postoperative surgical site wound infections and postoperative complications. A comprehensive computerised search was conducted for studies comparing LS with OS for the treatment of splenic rupture in the PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP, and Wanfang databases, with the search including studies published in any language between the creation of the databases and August 2023. Two researchers independently screened the literature and extracted the data. Literature quality was assessed using the Newcastle‐Ottawa Scale, and the included data were collated and analysed using Stata 17.0 software for meta‐analysis. Twenty‐two studies involving 1545 patients were included. LS was superior to OS in the following aspects: reduced risk of postoperative surgical site wound infection (OR = 0.19, 95% CI: 0.11–0.34, p = 0.000), shortened hospital stay (standardised mean difference = −1.73, 95% CI: −2.05 to −1.40, p = 0.000), and reduced postoperative complication rate (OR = 0.22, 95% CI: 0.16–0.31, p = 0.000). Compared with OS, LS has a lower rate of postoperative wound infection, shorter hospital stay, and reduced rate of postoperative complications. LS is safe and effective for the treatment of splenic rupture and can be promoted clinically. [ABSTRACT FROM AUTHOR]

Due to high stress, high ground temperature, high moisture, and other factors in deep mines, the risk of coal spontaneous combustion (CSC) is enhanced, seriously affecting the safety of coal mining. To achieve early prediction of spontaneous combustion in the No. 3 coal seam at the Juye coalfield in the deep mine, this paper employs a temperature-programmed device to analyze the changing pattern of single-index gases and composite gas indices with temperature derived from the gas produced during csc. It also optimizes the index gas of coal sample spontaneous combustion. Simultaneously, the characteristics of coal temperature and a four-level warning indicator system for CSC are determined based on the analysis of indicator gas growth rate method, carbon-to-oxygen ratio, and the characteristics of the indicator gas. The composite index gases of the No. 3 coal seam in Juye coalfield are selected in the initial oxidation stage (Rco), accelerated oxidation stage (R1, G1), intense oxidation stage (R2, G1, G3), and oxidative decomposition stage (G3). This leads to the construction of a six-level warning system consisting of initial warning value, blue, yellow, orange, red, and black levels. Meanwhile, warning thresholds are also established. [ABSTRACT FROM AUTHOR]

Based on the merits of solvent-free extraction of gaseous samples by needle trap, closed circulating purge system consisting of needle trap and water sample by peristaltic pump is established to enhance the Henry's law constant of analytes in the gas/liquid phase. In this study, the method for determination of dichlorvos, phorate, methyl parathion and malathion in groundwater by circulating extraction with needle trap coupled with Gas Chromatography was established. This method integrated sampling, extraction, purification, concentration, and chromatography. The optimum conditions for the extraction by needle trap include sampling flow rate of 11.11 mL/min and extraction temperature of 40℃. Under these conditions, the maximum breakthrough volume of 1 mg/L methyl parathion is 600 mL. The recoveries range from 62.3% to 103.0% for 5 μg/L, 50 μg/L and 200 μg/L analytes. Low level dichlorvos has a relative standard deviation of 26.1%, and other components are lower than 7.7%. The detection limits of the proposed method range from 0.016 to 0.157 μg/L, close to, or better than the current standard results and related study results.