Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyze...Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyzes the effect of the electrolyte-to-sulfur(E/S) ratios on battery energy density and the challenges for sulfur reduction reactions(SRR) under lean electrolyte conditions. Accordingly, we review the use of various polar transition metal sulfur hosts as corresponding solutions to facilitate SRR kinetics at low E/S ratios(< 10 μL mg~(-1)), and the strengths and limitations of different transition metal compounds are presented and discussed from a fundamental perspective. Subsequently, three promising strategies for sulfur hosts that act as anchors and catalysts are proposed to boost lean electrolyte Li–S battery performance. Finally, an outlook is provided to guide future research on high energy density Li–S batteries.展开更多
The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both hav...The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both have significant activation barriers, which severely limit the overall performance of energy conversion devices that utilize ORR/OER. Meanwhile, ORR is another very important electrochemical reaction involving oxygen that has been widely investigated. ORR occurs in aqueous solutions via two pathways: the direct 4-electron reduction or 2-electron reduction pathways from O_(2) to water(H_2O) or from O_(2) to hydrogen peroxide(H_2O_(2)). Noble metal electrocatalysts are often used to catalyze OER and ORR, despite the fact that noble metal electrocatalysts have certain intrinsic limitations, such as low storage. Thus, it is urgent to develop more active and stable low-cost electrocatalysts, especially for severe environments(e.g., acidic media). Theoretically, an ideal oxygen electrocatalyst should provide adequate binding to oxygen species. Transition metals not belonging to the platinum group metal-based oxides are a low-cost substance that could give a d orbital for oxygen species binding. As a result, transition metal oxides are regarded as a substitute for typical precious metal oxygen electrocatalysts. However, the development of oxide catalysts for oxygen reduction and oxygen evolution reactions still faces significant challenges, e.g., catalytic activity, stability, cost, and reaction mechanism. We discuss the fundamental principles underlying the design of oxide catalysts, including the influence of crystal structure, and electronic structure on their performance. We also discuss the challenges associated with developing oxide catalysts and the potential strategies to overcome these challenges.展开更多
The intention of this fundamental work is to explore the manipulation of a mixture of benzene,toluene and o-xylene separated from liquid-only transfer divided-wall column(LTS-DWC).First,two control structures are clea...The intention of this fundamental work is to explore the manipulation of a mixture of benzene,toluene and o-xylene separated from liquid-only transfer divided-wall column(LTS-DWC).First,two control structures are clearly proposed,including seven component control loops(CS1)and seven temperature control loops(CS2).However,two control structures can handle ±10% feed disturbances rather than larger feed disturbances.Subsequently,an equivalent four-column model by introducing withdraw ratio is developed to discuss the effect of two liquid-only side-stream on the overall reboiler duty.It is indicated that the second liquid-only side-stream withdraw ratio strongly affects the overall energy consumption.Hence,six-component control loops within the fixed second liquid-only side-stream withdraw ratio(CS3)is proposed and the purity of products returns to set value even as facing ±20% feed disturbances.Finally,based on the above results,it is established a temperature control structure(CS4)for controlling fixed second liquid-only side-stream withdraw ratio,which can cope with ±15% disturbances.Inspired by these findings,an insight into the dynamic control of LTS-DWC promotes the industrial implementation of DWC through new liquid-only side-stream configurations.展开更多
The development of highly active,selective,and stable electrocatalysts can facilitate the effective implementation of electrocatalytic CO_(2)conversion into fuels or chemicals for mitigating the energy crisis and clim...The development of highly active,selective,and stable electrocatalysts can facilitate the effective implementation of electrocatalytic CO_(2)conversion into fuels or chemicals for mitigating the energy crisis and climate problems.Therefore,it is necessary to achieve the goal through reasonable material design based on the actuality of the operational active site at the molecular scale.Inspired by the stimulating synergistic effect of coupled heteronuclear metal atoms,a novel Ni-Co atomic pairs configuration(denoted as NiN_(3)?CoN_(3)-NC)active site was theoretically screened out for improving electrochemical CO_(2)reduction reaction(CO_(2)RR).The structure of NiN_(3)?CoN_(3)-NC was finely regulated by adjusting Zn content in the precursors Zn/Co/Ni-zeolite imidazolate frameworks(Zn/Co/Ni-ZIFs)and pyrolysis temperature.The structural features of NiN_(3)?CoN_(3)-NC were systematically confirmed by aberration-corrected HAADF-STEM coupled with 3D atom-overlapping Gaussian-function fitting mapping,XAFS,and XRD.The results of theoretical calculations reveal that the synergistic effect of Ni-Co atomic pairs can effectively promote the*COOH intermediate formation and thus the overall CO_(2)RR kinetic was improved,and also restrained the competitive hydrogen evolution reaction.Due to the attributes of Ni-Co atomic pairs configuration,the developed NiN_(3)?CoN_(3)-NC with superior catalytic activity,selectivity,and durability,with a high turnover frequency of 2265 h^(-1)at-1.1 V(vs.RHE)and maximum Faradaic efficiency of 97.7%for CO production.This work demonstrates the great potential of DACs as highly efficient catalysts for CO_(2)RR,provides a useful strategy to design heteronuclear DACs,exploits the synergistic effect of multiple metal sites to facilitate complex CO_(2)RR catalytic reactions,and inspires more efforts to develop the potential of DACs in various fields.展开更多
The design methods for gradient coils are mostly based on discrete extrinsic methods(e.g.,the BioteSavart integration calculation),for which the surface normal vector strongly influences any numerical calculation of t...The design methods for gradient coils are mostly based on discrete extrinsic methods(e.g.,the BioteSavart integration calculation),for which the surface normal vector strongly influences any numerical calculation of the discretized surface.Previous studies are mostly based on regular or analytical surfaces,which allow normal vectors to be expressed analytically.For certain applications,design methods for extending currentcarrying surfaces from developable or analytic geometries to arbitrary surfaces generated from a scanned point cloud are required.The key task is to correctly express the discretized normal vectors to ensure geometrical accuracy of the designed coils.Mathematically,it has been proven that applying a Delaunay triangulation to approximate a smooth surface can result in the discrete elemental normal vectors converging to those of the original surface.Accordingly,this article uses Delaunay triangulation to expand upon previous design methods so that they encompass arbitrary piecewise continuous surfaces.Two design methods,the stream function and the so-called solid isotropic material with penalization(SIMP)method,are used to design circumvolute and noncircumvolute gradient coils on general surfaces.展开更多
<strong>Background: </strong>Studies have shown that long non-coding RNA (LncRNA) plays a critical role in maintaining genomic instability. The correlation between lncRNA and genomic instability is still w...<strong>Background: </strong>Studies have shown that long non-coding RNA (LncRNA) plays a critical role in maintaining genomic instability. The correlation between lncRNA and genomic instability is still worth exploring in bladder cancer as a new tumour marker. <strong>Methods: </strong>Therefore, combined with the lncRNA expression profile and somatic mutation profile of bladder cancer, we established a computing framework of lncRNA related to genomic instability and identified 58 new lncRNA related to genomic instability. Next, we identified a lncRNA signature (GILncSig), based on these 58 new genes, which divided patients into high-risk and low-risk groups. The clinical prognosis was significantly different and was further verified in an independent cohort of patients. <strong>Results: </strong>We confirmed that GILncSig is related to the genomic mutation rate of bladder cancer, suggesting that GILncSig can be used as an indicator of genomic instability. The results show that GILncSig has prognostic value independent of age, sex, grade, and stage and is vital in evaluating clinical prognosis. To sum up, this study provides a vital research basis and methods for further exploring the role of lncRNA in the genomic instability of bladder cancer and provides a theoretical basis for the identification of bladder cancer biomarkers related to genomic instability.展开更多
BACKGROUND Patients with hypothalamic-pituitary disease have the feature of central obesity,insulin resistance, and dyslipidemia, and there is increased prevalence of liver dysfunction consistent with non-alcoholic fa...BACKGROUND Patients with hypothalamic-pituitary disease have the feature of central obesity,insulin resistance, and dyslipidemia, and there is increased prevalence of liver dysfunction consistent with non-alcoholic fatty liver disease(NAFLD) in this population. The causes of hypopituitarism in the reported studies varied and combined pituitary hormone deficiency including central diabetes insipidus is much common in this population. This retrospective cross-sectional study was performed to analyze the clinical characteristics and related factors with NAFLD and cirrhosis in Chinese adult hypopituitary/panhypopituitary patients.AIM To analyze the clinical characteristics of and related risk factors for NAFLD in Chinese adult hypopituitary patients.METHODS Adult Chinese patients with hypopituitarism and/or panhypopituitarism were enrolled at the Pituitary Center of Peking Union Medical College Hospitalbetween August 2012 and April 2018. According to abdominal ultrasonography,these patients were divided into an NAFLD(-) group and an NAFLD(+) group,and the latter was further divided into an NAFLD group and a cirrhotic group.The data, such as patient characteristics, diagnosis, and treatment, were extracted from medical records, and statistical analysis was performed.RESULTS A total of 36 male and 14 female adult Chinese patients with hypopituitarism were included in this retrospective study; 43(87.0%) of these patients exhibited growth hormone(GH) deficiency, and 39(78.3%) had diabetes insipidus. A total of 27(54.0%) patients were diagnosed with NAFLD, while seven patients were cirrhotic. No significant differences were noted in serum GH or insulin-like growth factor 1 among patients with cirrhosis, subjects with NAFLD, and those without NAFLD. However, plasma osmolality and serum sodium concentration of the cirrhotic patients were 314.9 mOsm/kgH2 O and 151.0 mmol/L,respectively, which were significantly higher than those of the NAFLD patients(P = 0.036 and 0.042, respectively). Overweight/obesity and insulin resistance were common metabolic disorders in this population. The body mass index(BMI)and homeostasis model assessment of insulin resistance parameters of the cirrhotic patients were 27.7 kg/m2 and 9.57, respectively, which were significantly higher than those of the patients without NAFLD(P = 0.011 and0.044, respectively). A correlation analysis was performed, and fasting insulin concentration was positively associated with plasma osmolality in patients with NAFLD, after adjusting for gender, age, and BMI(r = 0.540, P = 0.046), but no correlation was noted in patients without NAFLD.CONCLUSION NAFLD is common in patients with hypopituitarism. Plasma osmolality and serum sodium levels of hypopituitary patients with cirrhosis are higher than those of subjects with NAFLD, and fasting insulin concentration is positively associated with plasma osmolality in patients with NAFLD, which suggests that hyperosmolality might be a contributor to the worsening of NAFLD in hypopituitary patients.展开更多
AIM:To conduct a network meta-analysis to evaluate the effectiveness of different chemotherapy regimens for patients with gastric cancer.METHODS:PubMed(1966-2011.12),the Cochrane Library(2011 Issue 2)and EMBASE(1974-2...AIM:To conduct a network meta-analysis to evaluate the effectiveness of different chemotherapy regimens for patients with gastric cancer.METHODS:PubMed(1966-2011.12),the Cochrane Library(2011 Issue 2)and EMBASE(1974-2011.12)were searched with the terms"gastric cancer"and"chemotherapy",as well as the medical subject headings.References from relevant articles and conferences were also included.Patients who had previous gastric surgery,radiation before or after surgery or chemotherapy before surgery were excluded.In this study,only randomized controlled trials(RCTs)were considered,and the end-point was the overall mortality.Direct comparisons were performed using traditional meta-analysis whereas indirect comparisons were performed using network meta-analysis.RESULTS:In total,31 RCTs with 7120 patients were included.Five chemotherapy regimens,fluorouracil(FU)+BCNU,FU+methyl-CCNU(mCCNU),FU+cisplatin,FU+anthracyclines and FU+mitomycin c(MMC)+cytarabine(Ara-c),were found to be less beneficial in terms of overall mortality.In contrast,four chemotherapy regimens were effective for the patients after surgery,including FU+MMC+adriamycin(FMA),FU+MMC(FM),Tegafur and MMC,There was no significant difference in terms of overall mortality among these regimens.The evidence for the FM regimen and MMC regimen was poor.Additionally,the FMA regimen,which includes a variety of chemotherapy drugs and causes many side effects,was not better than the Tegafur regimen.CONCLUSION:Although the four chemotherapy regimens were effective in patients with gastric cancer after surgery and the overall mortality revealed no significant difference among them in the network metaanalysis,thorough analysis of the results recommends Tegafur as the first-line adjuvant chemotherapy regimen for patients after complete resection.展开更多
A nanocomposite of MPNS/(Styrene-maleic anhydride) was prepared by the polymerization of methacryloxypropyl nano SiO2 (MPNS), styrene (ST) and maleic anhydride (MA) with benzoyl peroxide (BPO) as initiator in toluene....A nanocomposite of MPNS/(Styrene-maleic anhydride) was prepared by the polymerization of methacryloxypropyl nano SiO2 (MPNS), styrene (ST) and maleic anhydride (MA) with benzoyl peroxide (BPO) as initiator in toluene. The prepared samples were characterized by Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscope (TEM). Meanwhile, the nanocomposite was applied as a tanning agent in leather making and the results showed that leather treated with MPNS/SMA nanocomposite has excellent quality.展开更多
Objective To assess the efficiency and safety of a novel sodium-glucose co-transporter 2(SGLT2) inhibitor—SGLT2 inhibitors,in combination with insulin for type 1 diabetes mellitus(T1DM). Methods We searched Medline,E...Objective To assess the efficiency and safety of a novel sodium-glucose co-transporter 2(SGLT2) inhibitor—SGLT2 inhibitors,in combination with insulin for type 1 diabetes mellitus(T1DM). Methods We searched Medline,Embase,and the Cochrane Collaboration Library to identify the eligible studies published between January 2010 and July 2016 without restriction of language. The Food and Drug Administration(FDA) data and Clinical Trials(http://www.clinicaltrials.gov) were also searched. The included studies met the following criteria:randomized controlled trials; T1DM patients aged between 18 and 65 years old; patients were treated with insulin plus SGLT2 inhibitors for more than 2 weeks; patients' glycosylated hemoglobin(HbA1c) levels were between 7% and 12%. The SGLT2 inhibitors group was treated with SGLT2 inhibitors plus insulin,and the placebo group received placebo plus insulin treatment. The outcomes should include one of the following items:fasting blood glucose,HbA1c,glycosuria,or adverse effects. Data were analyzed by two physicians independently. The risk of bias was evaluated by using the Cochrane Collaboration's Risk of Bias tool and heterogeneity among studies was assessed using Chi-square test. Random effect model was used to analyze the treatment effects with Revman 5.3. Results Three trials including 178 patients were enrolled. As compared to the placebo group,SGLT2 inhibitor absolutely decreased fasting blood glucose [mean differences(MD)-2.47 mmol/L,95% confidence interval(CI)-3.65 to-1.28,P<0.001] and insulin dosage(standardized MD-0.75 U,95%CI-1.17 to-0.33,P<0.001). SGLT2 inhibitors could also increase the excretion of urine glucose(MD 131.09 g/24 h,95%CI 91.79 to 170.39,P<0.001). There were no significant differences in the incidences of hyperglycemia [odds ratio(OR) 1.82,95%CI 0.63 to 5.29,P=0.27],urinary tract infection(OR 0.95,95%CI 0.19 to 4.85,P=0.95),genital tract infection(OR 0.27,95%CI 0.01 to 7.19,P=0.43),and diabetic ketoacidosis(OR 6.03,95%CI 0.27 to 135.99,P=0.26) between the two groups. Conclusion SGLT2 inhibitors combined with insulin might be an efficient and safe treatment modality for T1DM patients.展开更多
Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-ma...Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-making.Methods A 21-question anonymous survey was distributed and collected at Peking Union Medical College Hospital,a major teaching hospital in Chinese Academy of Medical Sciences.Data of physicians' educational background,clinical training,patient workload per year and continuing medical education in AGHD were collected.Factors associated with appropriate answers were further analyzed by multivariate regression models.Results One hundred and eighteen internal medicine residents,endocrine fellows,attending physicians and visiting physicians responded to the survey.Among them,44.9% thought that AGHD patients should accept recombinant human growth hormone replacement therapy.Moreover,56.8% selected insulin tolerance test and growth hormone-releasing hormone-arginine test for the diagnosis of AGHD.Logistic regression analysis of physician demographic data,educational background,and work experience found no consistent independent factors associated with better decision-making,other than continued medical education,that were associated with treatment choice.Conclusions The physicians' reported management of AGHD in this major academic healthcare center in Beijing was inconsistent with current evidence.High quality continued medical education is required to improve Chinese physician management of AGHD.展开更多
BACKGROUND Cognitive impairments are core characteristics of schizophrenia,but are largely resistant to current treatments.Several recent studies have shown that highfrequency repetitive transcranial magnetic stimulat...BACKGROUND Cognitive impairments are core characteristics of schizophrenia,but are largely resistant to current treatments.Several recent studies have shown that highfrequency repetitive transcranial magnetic stimulation(rTMS)of the left dorsolateral prefrontal cortex(DLPFC)can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients.However,results are inconsistent across studies.AIM To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia.METHODS Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC(n=25)or sham stimulation(n=22)on weekdays for four consecutive weeks.Patients performed the pattern recognition memory(PRM)task from the Cambridge Neuropsychological Test Automated Battery at baseline,at the end of rTMS treatment(week 4),and 4 wk after rTMS treatment(week 8).Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms(SANS)and the Positive and Negative Syndrome Scale(PANSS).RESULTS There were no significant differences in PRM performance metrics,SANS total score,SANS subscores,PANSS total score,and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period,but PRM performance metrics(percent correct and number correct)and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group(all P<0.05).Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment.Moreover,the improvement in visual memory was correlated with the reduction in negative symptoms at week 8.In contrast,there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8(all P>0.05).CONCLUSION High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia,but these effects are delayed,potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.展开更多
Currently cellular networks do not have sufficient capacity to accommodate the exponential growth of mobile data requirements.Data can be delivered between mobile terminals through peer-to-peer WiFi communications(e.g...Currently cellular networks do not have sufficient capacity to accommodate the exponential growth of mobile data requirements.Data can be delivered between mobile terminals through peer-to-peer WiFi communications(e.g.WiFi direct),but contacts between mobile terminals are frequently disrupted because of the user mobility.In this paper,we propose a Subscribe-and-Send architecture and an opportunistic forwarding protocol for it called HPRO.Under Subscribe-and-Send,a user subscribes contents on the Content Service Provider(CSP) but does not download the subscribed contents.Some users who have these contents deliver them to the subscribers through WiFi opportunistic peer-to-peer communications.Numerical simulations provide a robust evaluation of the forwarding performance and the traffic offloading performance of Subscribe-and-Send and HPRO.展开更多
Friction plays a critical role in the function and maintenance of small-scale structures, where the conventional Coulomb friction law often fails. To probe the friction at small scales, here we present a molecular dyn...Friction plays a critical role in the function and maintenance of small-scale structures, where the conventional Coulomb friction law often fails. To probe the friction at small scales, here we present a molecular dynamics study on the process of dragging graphene nanoribbons on waved graphene substrates. The simulation shows that the induced friction on graphene with zero waviness is ultra-low and closely related to the surface energy barrier. On waved graphenes, the friction generally increases with the amplitude of the wave at a fixed period, but anomalously increases and then decreases with the period at a fixed amplitude. These findings provide insights into the ultra-low friction at small scales, as well as some guidelines into the fabrication of graphene-based nano-composites with high performance.展开更多
Dividing-wall columns(DWCs)are widely used in the separation of ternary mixtures,but rarely seen in the separation of petroleum fractions.This work develops two novel and energy-efficient designs of lubricant-type vac...Dividing-wall columns(DWCs)are widely used in the separation of ternary mixtures,but rarely seen in the separation of petroleum fractions.This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process(LVDP)for the separation of hydroisomerization fractions(HIF)of a hydrocracking tail oil(HTO).First,the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions.A LVDP used for HIF separation is proposed and optimized.Subsequently,two thermal coupling intensified technologies,including side-stream(SC)and dividing-wall column(DWC),are combined with the LVDP to develop side-stream vacuum distillation process(SC-LVDP)and dividing-wall column vacuum distillation process(DWC-LVDP).The performance of LVDP,SC-LVDP,and DWC-LVDP are evaluated in terms of energy consumption,capital cost,total annual cost,product yields,and stripping steam consumption.The results demonstrates that the intensified processes,SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP.DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils.This study attempts to combine DWC structure into the separation of petroleum fractions,and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.展开更多
Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable e...Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable energy consumption.Herein,a simple three-step strategy is reported to construct cobalt-iron nitride/alloy nanosheets on nickel foam(CoFe-NA/NF)as a bifunctional catalyst for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The electrocatalyst with optimized composition(CoFe-NA2/NF)can achieve ultralow overpotentials of 73 mV and 250 mV for HER and OER,respectively,at a current density of 10 mA cm^(-2) in 1 M KOH.Notably,the electrolyzer based on this electrocatalyst is able to boost the overall water splitting with a cell voltage of 1.564 V to deliver 10 mA cm^(-2) for at least 50 h without obvious performance decay.Furthermore,our experiment and theoretical calculation demonstrate that the combination of cobalt-iron nitride and alloy can have low hydrogen adsorption energy and facilitate water dissociation during HER.In addition,the surface reconstruction introduces metal oxyhydroxides to optimize the OER process.Our work may pave a new pathway to design bifunctional catalysts for overall water splitting.展开更多
BACKGROUND Split-dose regimens(SpDs)of 4 L of polyethylene glycol(PEG)have been established as the“gold standard”for bowel preparation;however,its use is limited by the large volumes of fluids required and sleep dis...BACKGROUND Split-dose regimens(SpDs)of 4 L of polyethylene glycol(PEG)have been established as the“gold standard”for bowel preparation;however,its use is limited by the large volumes of fluids required and sleep disturbance associated with night doses.Meanwhile,the same-day single-dose regimens(SSDs)of PEG has been recommended as an alternative;however,its superiority compared to other regimens is a matter of debate.AIM To compare the efficacy and tolerability between SSDs and large-volume SpDs PEG for bowel preparation.METHODS We searched MEDLINE/PubMed,the Cochrane Library,RCA,EMBASE and Science Citation Index Expanded for randomized trials comparing(2 L/4 L)SSDs to large-volume(4 L/3 L)SpDs PEG-based regimens,regardless of adjuvant laxative use.The pooled analysis of relative risk ratio and mean difference was calculated for bowel cleanliness,sleep disturbance,willingness to repeat the procedure using the same preparation and adverse effects.A random effects model or fixed-effects model was chosen based on heterogeneity analysis among studies.RESULTS A total of 18 studies were included.There was no statistically significant difference of adequate bowel preparation(relative risk=0.97;95%CI:0.92-1.02)(14 trials),right colon Boston Bowel Preparation Scale(mean difference=0.00;95%CI:-0.04,0.03)(9 trials)and right colon Ottawa Bowel Preparation Scale(mean difference=0.04;95%CI:-0.27,0.34)(5 trials)between(2 L/4 L)SSDs and large-volume(4 L/3 L)SpDs,regardless of adjuvant laxative use.The pooled analysis favored the use of SSDs with less sleep disturbance(relative risk=0.52;95%CI:0.40,0.68)and lower incidence of abdominal pain(relative risk=0.75;95%CI:0.62,0.90).During subgroup analysis,patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation than SpDs(P<0.05).No significant difference in adverse effects,including nausea,vomiting and bloating,was found between the two arms(P>0.05).CONCLUSION Regardless of adjuvant laxative use,the(2 L/4 L)SSD PEG-based arm was considered equal or better than the large-volume(≥3 L)SpDs PEG regimen in terms of bowel cleanliness and tolerability.Patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation due to the low-volume fluid requirement and less sleep disturbance.展开更多
基金the Research Foundation-Flanders (FWO) for a Research Project (G0B3218N)the financial support by the National Natural Science Foundation of China (22005054)+3 种基金Natural Science Foundation of Fujian Province (2021J01149)State Key Laboratory of Structural Chemistry (20200007)Sichuan Science and Technology Program (project No.: 2022ZYD0016 and 2023JDRC0013)the National Natural Science Foundation of China (project No. 21776120)。
文摘Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyzes the effect of the electrolyte-to-sulfur(E/S) ratios on battery energy density and the challenges for sulfur reduction reactions(SRR) under lean electrolyte conditions. Accordingly, we review the use of various polar transition metal sulfur hosts as corresponding solutions to facilitate SRR kinetics at low E/S ratios(< 10 μL mg~(-1)), and the strengths and limitations of different transition metal compounds are presented and discussed from a fundamental perspective. Subsequently, three promising strategies for sulfur hosts that act as anchors and catalysts are proposed to boost lean electrolyte Li–S battery performance. Finally, an outlook is provided to guide future research on high energy density Li–S batteries.
基金the Natural Science Foundation of China (22005250)National Key R D Program of China (2022YFB2502000)FWO (12ZV320N)。
文摘The electrochemical oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) are fundamental processes in a range of energy conversion devices such as fuel cells and metal–air batteries. ORR and OER both have significant activation barriers, which severely limit the overall performance of energy conversion devices that utilize ORR/OER. Meanwhile, ORR is another very important electrochemical reaction involving oxygen that has been widely investigated. ORR occurs in aqueous solutions via two pathways: the direct 4-electron reduction or 2-electron reduction pathways from O_(2) to water(H_2O) or from O_(2) to hydrogen peroxide(H_2O_(2)). Noble metal electrocatalysts are often used to catalyze OER and ORR, despite the fact that noble metal electrocatalysts have certain intrinsic limitations, such as low storage. Thus, it is urgent to develop more active and stable low-cost electrocatalysts, especially for severe environments(e.g., acidic media). Theoretically, an ideal oxygen electrocatalyst should provide adequate binding to oxygen species. Transition metals not belonging to the platinum group metal-based oxides are a low-cost substance that could give a d orbital for oxygen species binding. As a result, transition metal oxides are regarded as a substitute for typical precious metal oxygen electrocatalysts. However, the development of oxide catalysts for oxygen reduction and oxygen evolution reactions still faces significant challenges, e.g., catalytic activity, stability, cost, and reaction mechanism. We discuss the fundamental principles underlying the design of oxide catalysts, including the influence of crystal structure, and electronic structure on their performance. We also discuss the challenges associated with developing oxide catalysts and the potential strategies to overcome these challenges.
基金supported by National Natural Science Foundation of China(21908056)Shanghai Sailing Program(19YF1410800)Science and Technology Commission of Shanghai Municipality(19DZ2271100)。
文摘The intention of this fundamental work is to explore the manipulation of a mixture of benzene,toluene and o-xylene separated from liquid-only transfer divided-wall column(LTS-DWC).First,two control structures are clearly proposed,including seven component control loops(CS1)and seven temperature control loops(CS2).However,two control structures can handle ±10% feed disturbances rather than larger feed disturbances.Subsequently,an equivalent four-column model by introducing withdraw ratio is developed to discuss the effect of two liquid-only side-stream on the overall reboiler duty.It is indicated that the second liquid-only side-stream withdraw ratio strongly affects the overall energy consumption.Hence,six-component control loops within the fixed second liquid-only side-stream withdraw ratio(CS3)is proposed and the purity of products returns to set value even as facing ±20% feed disturbances.Finally,based on the above results,it is established a temperature control structure(CS4)for controlling fixed second liquid-only side-stream withdraw ratio,which can cope with ±15% disturbances.Inspired by these findings,an insight into the dynamic control of LTS-DWC promotes the industrial implementation of DWC through new liquid-only side-stream configurations.
基金the support of the Sichuan Science and Technology Program(2023NSFC0098)the Science and Technology Development Fund from Macao SAR(FDCT)(0081/2019/AMJ,0154/2019/A3,006/2022/ALC,and 0111/2022/A2)+2 种基金the Shenzhen-Hong Kong-Macao Science and Technology Research Programme(Type C)(SGDX20210823103803017)the Multi-Year Research Grants(MYRG2022-00026-IAPME)from Research&Development Office at University of Macaothe Frontier Project of Chengdu Tianfu New Area Institute(SWUST,2022ZY017)。
文摘The development of highly active,selective,and stable electrocatalysts can facilitate the effective implementation of electrocatalytic CO_(2)conversion into fuels or chemicals for mitigating the energy crisis and climate problems.Therefore,it is necessary to achieve the goal through reasonable material design based on the actuality of the operational active site at the molecular scale.Inspired by the stimulating synergistic effect of coupled heteronuclear metal atoms,a novel Ni-Co atomic pairs configuration(denoted as NiN_(3)?CoN_(3)-NC)active site was theoretically screened out for improving electrochemical CO_(2)reduction reaction(CO_(2)RR).The structure of NiN_(3)?CoN_(3)-NC was finely regulated by adjusting Zn content in the precursors Zn/Co/Ni-zeolite imidazolate frameworks(Zn/Co/Ni-ZIFs)and pyrolysis temperature.The structural features of NiN_(3)?CoN_(3)-NC were systematically confirmed by aberration-corrected HAADF-STEM coupled with 3D atom-overlapping Gaussian-function fitting mapping,XAFS,and XRD.The results of theoretical calculations reveal that the synergistic effect of Ni-Co atomic pairs can effectively promote the*COOH intermediate formation and thus the overall CO_(2)RR kinetic was improved,and also restrained the competitive hydrogen evolution reaction.Due to the attributes of Ni-Co atomic pairs configuration,the developed NiN_(3)?CoN_(3)-NC with superior catalytic activity,selectivity,and durability,with a high turnover frequency of 2265 h^(-1)at-1.1 V(vs.RHE)and maximum Faradaic efficiency of 97.7%for CO production.This work demonstrates the great potential of DACs as highly efficient catalysts for CO_(2)RR,provides a useful strategy to design heteronuclear DACs,exploits the synergistic effect of multiple metal sites to facilitate complex CO_(2)RR catalytic reactions,and inspires more efforts to develop the potential of DACs in various fields.
基金the National Natural Science Foundation of China under grant No.51675506.JGK acknowledges support from an EU2020 FET grant(737043 TiSuMR)the Deutsche Forschungsgesellschaft(DFG)(grant KO 1883/20-1 Metacoils)funding within the framework of the German Excellence Initiative under grant EXC 2082“3D Matter Made to Order”,from the VirtMat initiative“Virtual Materials Design”,and from an ERC Synergy Grant(951459,HiSCORE),European Union.
文摘The design methods for gradient coils are mostly based on discrete extrinsic methods(e.g.,the BioteSavart integration calculation),for which the surface normal vector strongly influences any numerical calculation of the discretized surface.Previous studies are mostly based on regular or analytical surfaces,which allow normal vectors to be expressed analytically.For certain applications,design methods for extending currentcarrying surfaces from developable or analytic geometries to arbitrary surfaces generated from a scanned point cloud are required.The key task is to correctly express the discretized normal vectors to ensure geometrical accuracy of the designed coils.Mathematically,it has been proven that applying a Delaunay triangulation to approximate a smooth surface can result in the discrete elemental normal vectors converging to those of the original surface.Accordingly,this article uses Delaunay triangulation to expand upon previous design methods so that they encompass arbitrary piecewise continuous surfaces.Two design methods,the stream function and the so-called solid isotropic material with penalization(SIMP)method,are used to design circumvolute and noncircumvolute gradient coils on general surfaces.
文摘<strong>Background: </strong>Studies have shown that long non-coding RNA (LncRNA) plays a critical role in maintaining genomic instability. The correlation between lncRNA and genomic instability is still worth exploring in bladder cancer as a new tumour marker. <strong>Methods: </strong>Therefore, combined with the lncRNA expression profile and somatic mutation profile of bladder cancer, we established a computing framework of lncRNA related to genomic instability and identified 58 new lncRNA related to genomic instability. Next, we identified a lncRNA signature (GILncSig), based on these 58 new genes, which divided patients into high-risk and low-risk groups. The clinical prognosis was significantly different and was further verified in an independent cohort of patients. <strong>Results: </strong>We confirmed that GILncSig is related to the genomic mutation rate of bladder cancer, suggesting that GILncSig can be used as an indicator of genomic instability. The results show that GILncSig has prognostic value independent of age, sex, grade, and stage and is vital in evaluating clinical prognosis. To sum up, this study provides a vital research basis and methods for further exploring the role of lncRNA in the genomic instability of bladder cancer and provides a theoretical basis for the identification of bladder cancer biomarkers related to genomic instability.
基金Supported by the National Key Program of Clinical Science,No.WBYZ 2011-873the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences,No.2016YFC0901500the Special Research Fund for Central Universities,Peking Union Medical College,No.2017PT31004
文摘BACKGROUND Patients with hypothalamic-pituitary disease have the feature of central obesity,insulin resistance, and dyslipidemia, and there is increased prevalence of liver dysfunction consistent with non-alcoholic fatty liver disease(NAFLD) in this population. The causes of hypopituitarism in the reported studies varied and combined pituitary hormone deficiency including central diabetes insipidus is much common in this population. This retrospective cross-sectional study was performed to analyze the clinical characteristics and related factors with NAFLD and cirrhosis in Chinese adult hypopituitary/panhypopituitary patients.AIM To analyze the clinical characteristics of and related risk factors for NAFLD in Chinese adult hypopituitary patients.METHODS Adult Chinese patients with hypopituitarism and/or panhypopituitarism were enrolled at the Pituitary Center of Peking Union Medical College Hospitalbetween August 2012 and April 2018. According to abdominal ultrasonography,these patients were divided into an NAFLD(-) group and an NAFLD(+) group,and the latter was further divided into an NAFLD group and a cirrhotic group.The data, such as patient characteristics, diagnosis, and treatment, were extracted from medical records, and statistical analysis was performed.RESULTS A total of 36 male and 14 female adult Chinese patients with hypopituitarism were included in this retrospective study; 43(87.0%) of these patients exhibited growth hormone(GH) deficiency, and 39(78.3%) had diabetes insipidus. A total of 27(54.0%) patients were diagnosed with NAFLD, while seven patients were cirrhotic. No significant differences were noted in serum GH or insulin-like growth factor 1 among patients with cirrhosis, subjects with NAFLD, and those without NAFLD. However, plasma osmolality and serum sodium concentration of the cirrhotic patients were 314.9 mOsm/kgH2 O and 151.0 mmol/L,respectively, which were significantly higher than those of the NAFLD patients(P = 0.036 and 0.042, respectively). Overweight/obesity and insulin resistance were common metabolic disorders in this population. The body mass index(BMI)and homeostasis model assessment of insulin resistance parameters of the cirrhotic patients were 27.7 kg/m2 and 9.57, respectively, which were significantly higher than those of the patients without NAFLD(P = 0.011 and0.044, respectively). A correlation analysis was performed, and fasting insulin concentration was positively associated with plasma osmolality in patients with NAFLD, after adjusting for gender, age, and BMI(r = 0.540, P = 0.046), but no correlation was noted in patients without NAFLD.CONCLUSION NAFLD is common in patients with hypopituitarism. Plasma osmolality and serum sodium levels of hypopituitary patients with cirrhosis are higher than those of subjects with NAFLD, and fasting insulin concentration is positively associated with plasma osmolality in patients with NAFLD, which suggests that hyperosmolality might be a contributor to the worsening of NAFLD in hypopituitary patients.
文摘AIM:To conduct a network meta-analysis to evaluate the effectiveness of different chemotherapy regimens for patients with gastric cancer.METHODS:PubMed(1966-2011.12),the Cochrane Library(2011 Issue 2)and EMBASE(1974-2011.12)were searched with the terms"gastric cancer"and"chemotherapy",as well as the medical subject headings.References from relevant articles and conferences were also included.Patients who had previous gastric surgery,radiation before or after surgery or chemotherapy before surgery were excluded.In this study,only randomized controlled trials(RCTs)were considered,and the end-point was the overall mortality.Direct comparisons were performed using traditional meta-analysis whereas indirect comparisons were performed using network meta-analysis.RESULTS:In total,31 RCTs with 7120 patients were included.Five chemotherapy regimens,fluorouracil(FU)+BCNU,FU+methyl-CCNU(mCCNU),FU+cisplatin,FU+anthracyclines and FU+mitomycin c(MMC)+cytarabine(Ara-c),were found to be less beneficial in terms of overall mortality.In contrast,four chemotherapy regimens were effective for the patients after surgery,including FU+MMC+adriamycin(FMA),FU+MMC(FM),Tegafur and MMC,There was no significant difference in terms of overall mortality among these regimens.The evidence for the FM regimen and MMC regimen was poor.Additionally,the FMA regimen,which includes a variety of chemotherapy drugs and causes many side effects,was not better than the Tegafur regimen.CONCLUSION:Although the four chemotherapy regimens were effective in patients with gastric cancer after surgery and the overall mortality revealed no significant difference among them in the network metaanalysis,thorough analysis of the results recommends Tegafur as the first-line adjuvant chemotherapy regimen for patients after complete resection.
文摘A nanocomposite of MPNS/(Styrene-maleic anhydride) was prepared by the polymerization of methacryloxypropyl nano SiO2 (MPNS), styrene (ST) and maleic anhydride (MA) with benzoyl peroxide (BPO) as initiator in toluene. The prepared samples were characterized by Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscope (TEM). Meanwhile, the nanocomposite was applied as a tanning agent in leather making and the results showed that leather treated with MPNS/SMA nanocomposite has excellent quality.
文摘Objective To assess the efficiency and safety of a novel sodium-glucose co-transporter 2(SGLT2) inhibitor—SGLT2 inhibitors,in combination with insulin for type 1 diabetes mellitus(T1DM). Methods We searched Medline,Embase,and the Cochrane Collaboration Library to identify the eligible studies published between January 2010 and July 2016 without restriction of language. The Food and Drug Administration(FDA) data and Clinical Trials(http://www.clinicaltrials.gov) were also searched. The included studies met the following criteria:randomized controlled trials; T1DM patients aged between 18 and 65 years old; patients were treated with insulin plus SGLT2 inhibitors for more than 2 weeks; patients' glycosylated hemoglobin(HbA1c) levels were between 7% and 12%. The SGLT2 inhibitors group was treated with SGLT2 inhibitors plus insulin,and the placebo group received placebo plus insulin treatment. The outcomes should include one of the following items:fasting blood glucose,HbA1c,glycosuria,or adverse effects. Data were analyzed by two physicians independently. The risk of bias was evaluated by using the Cochrane Collaboration's Risk of Bias tool and heterogeneity among studies was assessed using Chi-square test. Random effect model was used to analyze the treatment effects with Revman 5.3. Results Three trials including 178 patients were enrolled. As compared to the placebo group,SGLT2 inhibitor absolutely decreased fasting blood glucose [mean differences(MD)-2.47 mmol/L,95% confidence interval(CI)-3.65 to-1.28,P<0.001] and insulin dosage(standardized MD-0.75 U,95%CI-1.17 to-0.33,P<0.001). SGLT2 inhibitors could also increase the excretion of urine glucose(MD 131.09 g/24 h,95%CI 91.79 to 170.39,P<0.001). There were no significant differences in the incidences of hyperglycemia [odds ratio(OR) 1.82,95%CI 0.63 to 5.29,P=0.27],urinary tract infection(OR 0.95,95%CI 0.19 to 4.85,P=0.95),genital tract infection(OR 0.27,95%CI 0.01 to 7.19,P=0.43),and diabetic ketoacidosis(OR 6.03,95%CI 0.27 to 135.99,P=0.26) between the two groups. Conclusion SGLT2 inhibitors combined with insulin might be an efficient and safe treatment modality for T1DM patients.
基金Supported by National Natural Science Foundation of China(81400774)PUMC Youth Fund(33320140164 and 3332016128)
文摘Objective To evaluate physicians' attitude and knowledge about the management of adult growth hormone deficiency(AGHD) at Peking Union Medical College Hospital and impact factors associated with better decision-making.Methods A 21-question anonymous survey was distributed and collected at Peking Union Medical College Hospital,a major teaching hospital in Chinese Academy of Medical Sciences.Data of physicians' educational background,clinical training,patient workload per year and continuing medical education in AGHD were collected.Factors associated with appropriate answers were further analyzed by multivariate regression models.Results One hundred and eighteen internal medicine residents,endocrine fellows,attending physicians and visiting physicians responded to the survey.Among them,44.9% thought that AGHD patients should accept recombinant human growth hormone replacement therapy.Moreover,56.8% selected insulin tolerance test and growth hormone-releasing hormone-arginine test for the diagnosis of AGHD.Logistic regression analysis of physician demographic data,educational background,and work experience found no consistent independent factors associated with better decision-making,other than continued medical education,that were associated with treatment choice.Conclusions The physicians' reported management of AGHD in this major academic healthcare center in Beijing was inconsistent with current evidence.High quality continued medical education is required to improve Chinese physician management of AGHD.
基金Supported by Key Diagnosis and Treatment Program of Suzhou,No.LCZX201919 and No.LCZX202016The Scientific and Technological Program of Suzhou,No.SS201752 and No.SS202069Introduction Project of Suzhou Clinical Expert Team,No.SZYJTD201715。
文摘BACKGROUND Cognitive impairments are core characteristics of schizophrenia,but are largely resistant to current treatments.Several recent studies have shown that highfrequency repetitive transcranial magnetic stimulation(rTMS)of the left dorsolateral prefrontal cortex(DLPFC)can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients.However,results are inconsistent across studies.AIM To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia.METHODS Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC(n=25)or sham stimulation(n=22)on weekdays for four consecutive weeks.Patients performed the pattern recognition memory(PRM)task from the Cambridge Neuropsychological Test Automated Battery at baseline,at the end of rTMS treatment(week 4),and 4 wk after rTMS treatment(week 8).Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms(SANS)and the Positive and Negative Syndrome Scale(PANSS).RESULTS There were no significant differences in PRM performance metrics,SANS total score,SANS subscores,PANSS total score,and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period,but PRM performance metrics(percent correct and number correct)and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group(all P<0.05).Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment.Moreover,the improvement in visual memory was correlated with the reduction in negative symptoms at week 8.In contrast,there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8(all P>0.05).CONCLUSION High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia,but these effects are delayed,potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.
基金supported by the National Natural Science Foundation of China under Grants No. 61100208,No. 61100205the Natural Science Foundation of Jiangsu Province under Grant No. BK2011169+1 种基金the Foundation of Beijing University of Posts and Telecommunications under Grant No. 2013RC0309supported by the EU FP7 Project REC-OGNITION:Relevance and Cognition for SelfAwareness in a Content-Centric Internet
文摘Currently cellular networks do not have sufficient capacity to accommodate the exponential growth of mobile data requirements.Data can be delivered between mobile terminals through peer-to-peer WiFi communications(e.g.WiFi direct),but contacts between mobile terminals are frequently disrupted because of the user mobility.In this paper,we propose a Subscribe-and-Send architecture and an opportunistic forwarding protocol for it called HPRO.Under Subscribe-and-Send,a user subscribes contents on the Content Service Provider(CSP) but does not download the subscribed contents.Some users who have these contents deliver them to the subscribers through WiFi opportunistic peer-to-peer communications.Numerical simulations provide a robust evaluation of the forwarding performance and the traffic offloading performance of Subscribe-and-Send and HPRO.
基金support of the Science and Technology Development Fund from Macao SAR (FDCT-068/2014/A2 and FDCT-132/2014/A3) Multi-Year Research Grants (MYRG201400159-FST and MYRG2015-00017-FST) from Research & Development Office at University of Macaosupport of the National Natural Science Foundation of China (Grant No.11372279)
文摘Friction plays a critical role in the function and maintenance of small-scale structures, where the conventional Coulomb friction law often fails. To probe the friction at small scales, here we present a molecular dynamics study on the process of dragging graphene nanoribbons on waved graphene substrates. The simulation shows that the induced friction on graphene with zero waviness is ultra-low and closely related to the surface energy barrier. On waved graphenes, the friction generally increases with the amplitude of the wave at a fixed period, but anomalously increases and then decreases with the period at a fixed amplitude. These findings provide insights into the ultra-low friction at small scales, as well as some guidelines into the fabrication of graphene-based nano-composites with high performance.
基金funded by Shanghai Sailing Program (No.19YF1410800)National Natural Science Foundation of China(No. 21908056)。
文摘Dividing-wall columns(DWCs)are widely used in the separation of ternary mixtures,but rarely seen in the separation of petroleum fractions.This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process(LVDP)for the separation of hydroisomerization fractions(HIF)of a hydrocracking tail oil(HTO).First,the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions.A LVDP used for HIF separation is proposed and optimized.Subsequently,two thermal coupling intensified technologies,including side-stream(SC)and dividing-wall column(DWC),are combined with the LVDP to develop side-stream vacuum distillation process(SC-LVDP)and dividing-wall column vacuum distillation process(DWC-LVDP).The performance of LVDP,SC-LVDP,and DWC-LVDP are evaluated in terms of energy consumption,capital cost,total annual cost,product yields,and stripping steam consumption.The results demonstrates that the intensified processes,SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP.DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils.This study attempts to combine DWC structure into the separation of petroleum fractions,and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.
基金supported by the Science and Technology Development Fund from Macao SAR(FDCT)(0102/2019/A2,0035/2019/AGJ,0154/2019/A3,0081/2019/AMJ,and 0033/2019/AMJ)Multi-Year Research Grants(MYRG2017-00027-FST and MYRG2018-00003-IAPME)from Research&Development Office at University of Macao。
文摘Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable energy consumption.Herein,a simple three-step strategy is reported to construct cobalt-iron nitride/alloy nanosheets on nickel foam(CoFe-NA/NF)as a bifunctional catalyst for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The electrocatalyst with optimized composition(CoFe-NA2/NF)can achieve ultralow overpotentials of 73 mV and 250 mV for HER and OER,respectively,at a current density of 10 mA cm^(-2) in 1 M KOH.Notably,the electrolyzer based on this electrocatalyst is able to boost the overall water splitting with a cell voltage of 1.564 V to deliver 10 mA cm^(-2) for at least 50 h without obvious performance decay.Furthermore,our experiment and theoretical calculation demonstrate that the combination of cobalt-iron nitride and alloy can have low hydrogen adsorption energy and facilitate water dissociation during HER.In addition,the surface reconstruction introduces metal oxyhydroxides to optimize the OER process.Our work may pave a new pathway to design bifunctional catalysts for overall water splitting.
基金Supported by Startup Fund for scientific research,Fujian Medical University,No. 2019QH1181
文摘BACKGROUND Split-dose regimens(SpDs)of 4 L of polyethylene glycol(PEG)have been established as the“gold standard”for bowel preparation;however,its use is limited by the large volumes of fluids required and sleep disturbance associated with night doses.Meanwhile,the same-day single-dose regimens(SSDs)of PEG has been recommended as an alternative;however,its superiority compared to other regimens is a matter of debate.AIM To compare the efficacy and tolerability between SSDs and large-volume SpDs PEG for bowel preparation.METHODS We searched MEDLINE/PubMed,the Cochrane Library,RCA,EMBASE and Science Citation Index Expanded for randomized trials comparing(2 L/4 L)SSDs to large-volume(4 L/3 L)SpDs PEG-based regimens,regardless of adjuvant laxative use.The pooled analysis of relative risk ratio and mean difference was calculated for bowel cleanliness,sleep disturbance,willingness to repeat the procedure using the same preparation and adverse effects.A random effects model or fixed-effects model was chosen based on heterogeneity analysis among studies.RESULTS A total of 18 studies were included.There was no statistically significant difference of adequate bowel preparation(relative risk=0.97;95%CI:0.92-1.02)(14 trials),right colon Boston Bowel Preparation Scale(mean difference=0.00;95%CI:-0.04,0.03)(9 trials)and right colon Ottawa Bowel Preparation Scale(mean difference=0.04;95%CI:-0.27,0.34)(5 trials)between(2 L/4 L)SSDs and large-volume(4 L/3 L)SpDs,regardless of adjuvant laxative use.The pooled analysis favored the use of SSDs with less sleep disturbance(relative risk=0.52;95%CI:0.40,0.68)and lower incidence of abdominal pain(relative risk=0.75;95%CI:0.62,0.90).During subgroup analysis,patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation than SpDs(P<0.05).No significant difference in adverse effects,including nausea,vomiting and bloating,was found between the two arms(P>0.05).CONCLUSION Regardless of adjuvant laxative use,the(2 L/4 L)SSD PEG-based arm was considered equal or better than the large-volume(≥3 L)SpDs PEG regimen in terms of bowel cleanliness and tolerability.Patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation due to the low-volume fluid requirement and less sleep disturbance.
