Copper-Mediated Oxidative Chloro- and Bromodifluoromethylation of Phenols.

The first oxidative chloro- and bromodifluoromethylation of phenols with (CH3)3SiCF2X and CuX (X = Cl or Br) in the presence of Selectfluor under mild reaction conditions was developed. This protocol provided a practical and efficient method for the synthesis of a diverse range of biologically valuable and synthetically challenging chloro- and bromodifluoromethyl aryl ethers. Preliminary mechanistic studies suggest that this reaction proceeded through a difluorocarbene-involved oxidative coupling process.

N-Trifluoromethoxyphthalimide: A Shelf-Stable Reagent for Nucleophilic Trifluoromethoxylation.

Due to the unique properties of the OCF3 group, trifluoromethyl ether compounds play an important role in pharmaceuticals and agrochemicals. Recently, considerable attention has been focused on the development of practical and convenient reagents for the direct incorporation of the OCF3 group into organic compounds. Herein, we reported a new trifluoromethoxylating reagent N-trifluoromethoxyphthalimide (Phth-OCF3). The reagent was a stable solid and released an OCF3 anion under mild reaction conditions. We demonstrated the application of Phth-OCF3 for the nucleophilic trifluoromethoxylation of various alkyl electrophiles.

Photoredox-Catalyzed and Silane-Mediated Hydrofluoromethylation of Unactivated Alkenes with Fluoroiodomethane in Water.

The first hydrofluoromethylation of unactivated alkenes with fluoroiodomethane and hydrosilanes is developed by merging photoredox catalysis and silane-mediated deiodination processes. The key to the success of this reaction is the use of water as the solvent to enhance the activity of CH2F radical toward unactivated alkenes.

Melatonin Ameliorates the Progression of Alzheimer's Disease by Inducing TFEB Nuclear Translocation, Promoting Mitophagy, and Regulating NLRP3 Inflammasome Activity.

Background: The NLRP3 inflammasome is overactivated in the brains of APP/PS1 transgenic mice and AD patients, and mitophagy has an obvious negative regulatory role on NLRP3 inflammasome activation. The protective effect of melatonin in AD may be related to the regulation of mitophagy and NLRP3 inflammasome activity. TFEB plays a critical role in maintaining autophagy/mitophagy. Studies have found that TFEB plays a protective role in AD. Methods: APP/PS1 transgenic mice were given melatonin in their drinking water for 3 months. Compared with mice without melatonin treatment, the mice given melatonin showed changes in the following features: (1) cognitive function, (2) mitophagy-related proteins in the brain, (3) ROS, (4) NLRP3 inflammasome and related proteins and the concentrations of inflammatory cytokines, and (5) Aß deposition. In in vitro experiments, effects of melatonin on mitophagy, NLRP3 inflammasome activity, and TFEB in SH-SY5Y cells with Aß 25-35 were observed. TFEB knockdown was implemented in combination with Aß 25-35 and melatonin treatment, and the expressions of TFEB, Parkin, p62, IL-1ß, caspase-1, ROS, and IL-18 were explored. Results: Melatonin improved cognitive function in APP/PS1 transgenic mice and decreased ROS and senile plaques. Melatonin promoted mitophagy in SH-SY5Y cells with Aß 25-35 and APP/PS1 transgenic mice. NLRP3 inflammasome activity was inhibited, and the concentrations of IL-18 and IL-1ßwere clearly reduced. Compared with C57/BL6J mice, the amount of TFEB in the brain nucleus of APP/PS1 transgenic mice was decreased. Melatonin treatment increased the nuclear translocation of TFEB in SH-SY5Y cells. TFEB knockout was implemented in combination with Aß 25-35 and MT treatment; the expressions of Parkin, p62, caspase-1, IL-1ß, IL-18, and ROS were accelerated. Conclusions: Melatonin promotes mitophagy by inducing TFEB nuclear translocation, downregulates NLRP3 inflammasome activation, and exerts protective effects in SH-SY5Y cells and APP/PS1 transgenic mice.

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis.

OBJECTIVES: The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies. METHODS: MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively. RESULTS: A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001). CONCLUSIONS: Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

Nucleophilic and Radical Heptafluoroisopropoxylation with Redox-Active Reagents.

The heptafluoroisopropyl group (CF(CF3 )2 ) is prevalent in pharmaceuticals and agrichemicals. However, heptafluoroisopropoxylated (OCF(CF3 )2 ) compounds remain largely underexplored, presumably due to the lack of efficient access to these compounds. Herein, we disclose the practical and efficient heptafluoroisopropoxylation reactions through the invention of a series of redox-active N-OCF(CF3 )2 reagents. These reagents were readily prepared from the oxidative heptafluoroisopropylation of hydroxylamines with AgCF(CF3 )2 . The substitutions on the nitrogen atom significantly affected the properties and reactivities of N-OCF(CF3 )2 reagents. Accordingly, two types of N-OCF(CF3 )2 reagents including N-OCF(CF3 )2 phthalimide A and N-OCF(CF3 )2 benzotriazolium salt O' were used as OCF(CF3 )2 anion and radical precursors, respectively. This protocol enables the direct heptafluoroisopropoxylation of a range of substrates, delivering the corresponding products in moderate to excellent yields.

Copper and Zinc Copromoted Bromo(chloro)trifluoromethylation of Alkenes and Alkynes with Trifluoromethanesulfonic Anhydride.

The first copper and zinc copromoted trifluoromethylation using trifluoromethanesulfonic anhydride (Tf2O) as a trifluoromethylating reagent has been developed. The reaction of alkenes or alkynes with Tf2O in the presence of CuX2 (X = Br, Cl), Zn powder, and 2,2'-bipyridine affords bromo(chloro)trifluoromethylated products in good yields. CuX2 plays a dual role as the catalyst and halide source, whereas 2,2'-bipyridine acts as both the activation reagent and ligand.

Occupational exposure limit of trimethyltin chloride in workplace air / 中国职业医学

OBJECTIVE: To establish the occupational exposure limit for trimethyltin chloride(TMT) in workplace air. METHODS:According to the GBZ/T 210.1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace, the relevant literatures on toxicology, population epidemiology and foreign occupational exposure limit of TMT were collected and analyzed. A total of 276 workers with TMT occupational exposure were selected as the exposure group and 25 workers without TMT occupational exposure were selected as the control group.Worksite survey of occupational health and occupational medical examination were carried out. Combined with the literature data, the occupational exposure limit of TMT in the workplace air was calculated by using the 90% medical reference level(internal exposure limit) of the urine TMT level of workers who exposed to TMT without moderate hypokalemia. RESULTS: The time-weighted average of TMT in the workplace air is 0.100 mg/m~3 and the short-term exposure limit is 0.200 mg/m~3 in the United States based on total organic tin. The highest concentration of TMT in the workplace air in Germany is 0.005 mg/m~3. The literature data analysis results showed that the incubation period of TMT poisoning is mostly 3-6 days, and the main symptoms of TMT poisoning are hypokalemia in the early stage, followed by neuropsychiatric symptoms such as headache, memory loss and aggressive behavior. The median(M) and the 0-100 th percentile(P_0-P_(100)) of exposure to TMT were 8.35(< 0.20-91.40) μg/m~3 in the exposure group. The individual TMT exposure level of workers in different positions from high to low were crushing, granulation, withdrawal and assembly positions. The M(P_0-P_(100)) of urinary TMT level in the exposure group was 16.94(<0.50-591.14) μg/L. There was a positive correlation between the individual TMT exposure level and urine TMT level in the exposure group(Spearman correlation coefficient=0.62, P<0.01). The detection rate of hypokalemia in the exposure group was higher than that in the control group(26.1% vs 4.0%, P < 0.05). However, there was no significant difference in the detection rate of moderate hypokalemia between the two groups(3.3% vs 0.0%, P>0.05). The 90% medical reference value of urine TMT was 89.90 μg/L in workers exposed to TMT without moderate hypokalemia. CONCLUSION: In order to prevent acute hypokalemia damage caused by TMT, we recommended that the occupational exposure limit of TMT in the workplace air should be set at 0.025 mg/m~3 in China, and this limit should be the maximum allowable concentration.

Latest Progresses in Surgical Treatment of Median Arcuate Ligament Syndrome / 中国医学科学院学报

Median arcuate ligament syndrome(MALS)is compression of the celiac trunk by the median arcuate ligament.Median arcuate ligament release is the corner stone for the surgical treatment of MALS.Open surgery,laparoscopic surgery,and robot-assisted surgery have been developed,among which laparoscopic surgery has been proposed as the preferred approach in view of its minimal trauma and short hospital stay.Auxiliary celiac plexus neurolysis could further alleviate the patient's discomfort.Moreover,vascular reconstitution is of vital importance in the case of persistent stenosis in the celiac artery despite of median arcuate ligament decompression.Vascular reconstruction has satisfactory long-term patency rate,while endovascular treatment is less invasive.This article aims to summarize the consensuses and advances and shed light on the surgical treatment of MALS.

Application Progress of Arterial Spin Labeling Magnetic Resonance Imaging in Renal Perfusion Analysis / 中国医学科学院学报

Arterial spin labeling is a noninvasive,quantitative method for perfusion imaging,which does not need any contrast media.This technique has been used in the renal perfusion analysis.In this article,we briefly introduced this technique and summarized its application in healthy volunteers,acute kidney injury,chronic kidney diseases,renovascular diseases,renal tumors,and renal transplantation.

The compilation and explanation of Technical Plan for Emergency Treatment of Acute 1,2-Dichloroethane Poisoning / 中国职业医学

Acute 1,2-dichloroethane poisoning causes serious illness, deaths and is a social event of great influence. The compilation of Technical Plan for Emergency Treatment of Acute 1,2-Dichloroethane Poisoning provides scientific guidance for effective treatment of 1,2-dichloroethane poisoning events. The plan describes in detail the specific practice and technical requirements of six links in the process of handling emergency of acute 1,2-dichloroethane poisoning, including accident investigation and treatment, risk assessment, collection and testing of samples, medical treatment, health monitoring and emergency response, et al. The key contents of individual protection requirements, investigation content, etiology determination, medical assistance and health education in the disposal of poisoning incidents were clarified, and the procedures and requirements of health education were added. The technical scheme is scientific, objective and operable, which can provide scientific guidance for the effective treatment of 1,2-dichloroethane poisoning accidents.

Clinical Analysis of the Treatment of Iliac Limb Occlusion Following Endovascular Abdominal Aortic Aneurysm Repair / 中国医学科学院学报

Objective To explore the cause and the treatment strategies of iliac limb occlusion after endovascular abdominal aortic aneurysm repair(EVAR). Methods The patients receiving EVAR in PUMC Hospital from January 2015 to December 2020 were retrospectively analyzed.Sixteen(2.7%)cases of iliac limb occlusion were identified,among which 6,9,and 1 cases underwent surgical bypass,endovascular or hybrid procedure,and conservative treatment,respectively. Results Fifteen cases were successfully treated.During the 10.6-month follow-up,2 cases receiving hybrid treatment underwent femoral-femoral bypass due to re-occlusion of the iliac limb. Conclusions Iliac limb occlusion mostly occurs in the acute phase after EVAR,and endovascular or hybrid treatment can be the first choice for iliac limb occlusion.It is suggested to focus on the risk factors for prevention.

The eighth version of American Joint Committee on Cancer nodal classification for high grade pancreatic neuroendocrine tumor should be generalized for the whole population with this disease.

Several indexes evaluating the lymph node metastasis of pancreatic neuroendocrine tumor (pNET) have been raised. We aimed to compare the prognostic value of the indexes via the analysis of Surveillance, Epidemiology, and End Results (SEER) database.We identified pNETs patients from SEER database (2004-2015). The prognostic value of N classification which adopted the 8th American Joint Committee on Cancer (AJCC) N classification for well differentiated pNET, revised N classification (rN) which adopted the AJCC 8th N classification for exocrine pancreatic cancer (EPC) and high grade pNET, lymph node ratio and log odds of positive nodes were analyzed.A total of 1791 eligible patients in the SEER cohort were included in this study. The indexes N, rN, lymph node ratio, and log odds of positive nodes were all significant independent prognostic factors for the overall survival. Specifically, the rN had the lowest akaike information criterion of 4050.19, the highest likelihood ratio test (χ) of 48.87, and the highest C-index of 0.6094. The rN was significantly associated with age, tumor location, tumor differentiation, T classification and M classification (P < .05 for all).The 8th version of AJCC N classification for high grade pNET could be generalized for the pNET population.

Oxidative Hydro-, Bromo-, and Chloroheptafluoroisopropylation of Unactivated Alkenes with Heptafluoroisopropyl Silver.

Oxidant-induced three-component hydro-, bromo-, and chloroheptafluoroisopropylation of unactivated alkenes are disclosed. In these reactions, the CF(CF3)2 radical was generated from the oxidation of AgCF(CF3)2. Then the addition of this perfluorinated radical to alkenes, followed by hydrogenation, bromination, or chlorination, gave the corresponding difunctionalized CF(CF3)2-containing products in high yields.

Femoral-popliteal Arteriosclerosis Obliterans:Review of Evidence-based Studies on Drug-eluting Endovascular Treatment / 中国医学科学院学报

Atherosclerosis-related diseases have increasingly become health concerns with the increased living conditions and aging.Globally,about 200 million people have suffered from arteriosclerosis obliterans(ASO),which can even be life-threatening in some cases.The past seven decades have witnessed the rapid advances in the treatment of ASO,which has developed from surgery to endovascular interventions including plain balloon angioplasty,bare metal stent placement,drug-coated balloon,and drug-eluting stent.However,the roles of these new techniques for femoral-popliteal lesions,especially their real-world clinical outcomes and indications,remain unclear.This article reviews the latest evidences on the use of drug-eluting devices in treating femoral-popliteal arteriosclerosis obliterans.

Utility of endovascular simulation to improve technical performance and stimulate interest of medical students in vascular surgery / 基础医学与临床

Objective To determine whether endovascular simulation training in medical students may increase technical proficiency,enhance interest in vascular surgery. Methods We recruited 30 medical students from Pe-king Union Medical College prospectively. We gave these students an eight-week course with a structured curricu-lum comprised of weekly simulator sessions and theoretical lessons. A test of iliac artery balloon dilatation was con-ducted in pre-and post-course. Performance was assessed. Demographics and subjective survey data,including in-terest in vascular surgery were obtained pre-and post-course from the students too. Results Parameters measured on the standardized global endovascular rating scale,including angiography skills,wire handling and interventional criteria as well as simulator-generated metrics such as fluoroscopy time and volume of contrast used significantly im-proved from pre-to post-course values for the medical students(P<0.05) All the students agreed or strongly agreed that the simulation course increased their interest in vascular surgery. Conclusions A simulation-based endovascu-lar course improves technical performance with interest in vascular surgery training of medical students. The simula-tor is quite potential in the medical students training.

Correlation of Matrix Metalloproteinases-9 with Microemboli Shedding in Carotid Endarterectomy / 中国医学科学院学报

Objective To investigate the change of serum matrix metalloproteinases-9 (MMP-9) expression before,during,and after carotid endarterectomy (CEA) and to investigate the prognostic role of MMP-9. Methods Forty carotid stenosis patients who underwent CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from February to September 2012 were enrolled in this study. Based on the findings of transcranial doppler monitoring,patients were divided into embolic-positive group and emboli-negative group. Serum samples were obtained from 40 consecutive patients undergoing CEA before operation (pre-op),before de-clamping,30 minutes after de-clamping,and 12 hours after operation (12-h post-op). MMP-9 expression was quantified using enzyme-linked immunosorbent assay and gelatin zymography. Student's t-test and chi-square test were used to compare the differences between these two groups. Results Of these 40 patients,microemboli were detected in 8 patients. The 12-h post-op MMP-9 level was significantly higher than the pre-op level in the emboli-positive group [(904.27±369.47)ng/ml vs. (333.88±126.32) ng/ml,t=4.132,P=0.001].However,there was no difference between pre-op and 12-h post-op MMP-9 levels in the emboli-negative group [(375.83±194.36) ng/ml vs. (472.74±271.21) ng/ml,t=-1.643,P=0.081]. Gelatin zymography also showed higher MMP-9 activity in the emboli-positive group than in the emboli-negative group. Conclusion Serum MMP-9 concentration remarkably increases 12 hours after CEA in patients with microemboli shedding,suggesting MMP-9 may be a potential biomarker for CEA-related cerebral ischemic injury.

Research on the clinical pathway on chronic mild occupational cadmium poisoning / 中国职业医学

OBJECTIVE: To establish the clinical pathway of chronic mild occupational cadmium poisoning,and to promote the application of clinical pathway in the treatment of occupational diseases. METHODS: Chronic mild occupational cadmium poisoning was selected as a disease for a pilot study based on GBZ 17-2015 Diagnosis of Occupational Cadmium Poisoning. The diagnosis and treatment scheme and the clinical pathway were developed based on the theory of evidencebased medicine and expert consultation. It was then used and evaluated in clinical practice in several hospitals. RESULTS: The content of clinical pathway of chronic mild occupational cadmium poisoning included the standard in-hospital treatment process protocol,the clinical pathway forms and the consent document for patients. The clinical application of the pathway significantly improved the outcome of treatment,shortened hospital stays and effectively control hospitalization expenses.CONCLUSION: The clinical pathway for chronic mild occupational cadmium poisoning is rational and feasible. The result confirms that the clinical pathway may have good application prospect for the treatment of occupational diseases.

Toxicity of 1,2-dichloroethane and its metabolites on human astrocytes / 中国职业医学

OBJECTIVE: To explore the toxicity of 1,2-dichloroethane( 1,2-DCE) and its metabolites on human astrocytes( HAs). METHODS: Different doses of 1,2-DCE( 5. 00,10. 00,25. 00,50. 00 and 100. 00 mmol/L),2-chlorohydrins( 5. 00,25. 00,50. 00,100. 00 and 200. 00 mmol/L),2-chloroacetaldehyde( 1. 00,5. 00,10. 00,20. 00 and 50. 00 mmol / L) and chloroacetic acid( 0. 01,0. 05,0. 10,0. 50 and 1. 00 mmol / L) were used for treating HAs in vitro during their logarithmic phase. After 24 hours of culture,the morphology of HAs was observed by fluorescent inverted phase contrast microscope. The survival rate and the inhibition ratio of HAs were detected by CCK-8 colorimetry to estimate the50% inhibiting concentration in 24 hours( 24 h-IC50). The apoptosis of HAs was tested by double-labeling and flow cytometry using Annexin Ⅴ-fluorescein isothiocyanate and propidium iodide. RESULTS: The morphology of HAs changed in varying degrees after 24 hours exposure to 1,2-DCE,2-chlorohydrins,2-chloroacetaldehyde and chloroacetic acid. The changes included smaller size of cells,pseudopodia tapering,increased intracellular particles and suspension of circular cells and decreased transparency of cells. With the increasing does of 1,2-DCE,2-chlorohydrins,2-chloroacetaldehyde and chloroacetic acid exposure,the survival rates of HAs decreased( P < 0. 01),while its inhibition ratios increased( P <0. 01). They all showed dose-effect relationship. 24 h-IC50 of the above 4 chemicals were 56. 25,235. 00,26. 43 and1. 38 mmol / L,respectively. The 1,2-DCE,2-chlorohydrins and chloroacetic acid could induce the apoptosis of HAs and the apoptosis rate of HAs was positively correlated with the 3 kinds of chemicals( P < 0. 01). CONCLUSION: 1,2-DCE and its metabolites 2-chloroacetaldehyde,2-chlorohydrins and chloroacetic acid can lead to toxic damage and induce the apoptosis of HAs. Chloroacetic acid has the strongest toxicity among the metabolites.

Prediction of Cerebral Hyperperfusion Syndrome with Velocity Blood Pressure Index / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cerebral hyperperfusion syndrome is an important complication of carotid endarterectomy (CEA). An >100% increase in middle cerebral artery velocity (MCAV) after CEA is used to predict the cerebral hyperperfusion syndrome (CHS) development, but the accuracy is limited. The increase in blood pressure (BP) after surgery is a risk factor of CHS, but no study uses it to predict CHS. This study was to create a more precise parameter for prediction of CHS by combined the increase of MCAV and BP after CEA.</p><p><b>METHODS</b>Systolic MCAV measured by transcranial Doppler and systematic BP were recorded preoperatively; 30 min postoperatively. The new parameter velocity BP index (VBI) was calculated from the postoperative increase ratios of MCAV and BP. The prediction powers of VBI and the increase ratio of MCAV (velocity ratio [VR]) were compared for predicting CHS occurrence.</p><p><b>RESULTS</b>Totally, 6/185 cases suffered CHS. The best-fit cut-off point of 2.0 for VBI was identified, which had 83.3% sensitivity, 98.3% specificity, 62.5% positive predictive value and 99.4% negative predictive value for CHS development. This result is significantly better than VR (33.3%, 97.2%, 28.6% and 97.8%). The area under the curve (AUC) of receiver operating characteristic: AUC(VBI) = 0.981, 95% confidence interval [CI] 0.949-0.995; AUC(VR) = 0.935, 95% CI 0.890-0.966, P = 0.02.</p><p><b>CONCLUSIONS</b>The new parameter VBI can more accurately predict patients at risk of CHS after CEA. This observation needs to be validated by larger studies.</p>