High-Temperature Superconductivity in La_(3)Ni_(2)O_(7)

Motivated by the recent discovery of high-temperature superconductivity in bilayer La_(3)Ni_(2)O_(7) under pressure,we study its electronic properties and superconductivity due to strong electron correlation.Using the inversion symmetry,we decouple the low-energy electronic structure into block-diagonal symmetric and antisymmetric sectors.It is found that the antisymmetric sector can be reduced to a one-band system near half filling,while the symmetric bands occupied by about two electrons are heavily overdoped individually.Using the strong coupling mean field theory,we obtain strong superconducting pairing with B_(1g)symmetry in the antisymmetric sector.We propose that due to the spin-orbital exchange coupling between the two sectors,B_(1g)pairing is induced in the symmetric bands,which in turn boosts the pairing gap in the antisymmetric band and enhances the high-temperature superconductivity with a congruent d-wave symmetry in pressurized La_(3)Ni_(2)O_(7).

Realizing methanol synthesis from CO and water via the synergistic effect of Cu^(0)/Cu^(+)over Cu/ZrO_(2) catalyst

The optimizing utilization of ca rbon resources has drawn wide attention all over the world,while exploiting the high-efficiency catalytic routes remains a challenge.Here,a direct methanol synthesis route is realized from pure CO and H_(2)O over 10%Cu/t-ZrO_(2) catalyst,where the time yield of methanol is144.43 mmol mol_(Cu)^(-1)h^(-1)and the methanol selectivity in hydrocarbons is 100%,The Cu species highly dispersed in the t-ZrO_(2) support lead parts of them in the cationic state.The Cu^(+)sites contribute to the dissociation of H_(2)O,providing the H*source for methanol synthesis,while the formed Cu^(0) sites promote the absorption and transfer of H*during the reaction.Moreover,the H_(2)O is even a better H resource than H_(2) due to its better dissociation effectivity in this catalytic system.The present work offers a new approach for methanol synthesis from CO and new insight into the process of supplying H donor.

Achieving the synergistic of strength and ductility in Mg-15Gd-1Zn-0.4Zr alloy with hierarchical structure

Currently,the hierarchical structure is one of the most effective means to enhance the strength and plasticity of metal materials,since the strain localization can be effectively delayed by the coordination of the unique microstructure.In this study,a hierarchical structure of Mg-15Gd-1Zn-0.4Zr(GZ151K)alloys containing grain,twin,and precipitation structural units was prepared by ultrasonic surface rolling process(USRP)and recrystallization annealing(RU).The results showed that the stress gradient generated by USRP formed a twin gradient structure,which will activate the twin-assisted precipitation(TAP)effect and twin-induced recrystallization(TIR)effect during RU.Then,the twin gradient structure transformed into a twin-precipitation gradient structure,and finally into a hierarchical structure with grain-twinprecipitation as the increasement of recrystallization degree.Besides,the dual gradient structure with twin and precipitation structural units had the highest strength and microhardness owing to the precipitation strengthening.However,the hierarchical structure with grain,twin,and precipitation structural units exhibited the most excellent combination of strength and plasticity under grain refinement and precipitation strengthening.

Molecule aging induced by electron attacking

Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.

Discovering Latent Variables for the Tasks With Confounders in Multi-Agent Reinforcement Learning

Efficient exploration in complex coordination tasks has been considered a challenging problem in multi-agent reinforcement learning(MARL). It is significantly more difficult for those tasks with latent variables that agents cannot directly observe. However, most of the existing latent variable discovery methods lack a clear representation of latent variables and an effective evaluation of the influence of latent variables on the agent. In this paper, we propose a new MARL algorithm based on the soft actor-critic method for complex continuous control tasks with confounders. It is called the multi-agent soft actor-critic with latent variable(MASAC-LV) algorithm, which uses variational inference theory to infer the compact latent variables representation space from a large amount of offline experience.Besides, we derive the counterfactual policy whose input has no latent variables and quantify the difference between the actual policy and the counterfactual policy via a distance function. This quantified difference is considered an intrinsic motivation that gives additional rewards based on how much the latent variable affects each agent. The proposed algorithm is evaluated on two collaboration tasks with confounders, and the experimental results demonstrate the effectiveness of MASAC-LV compared to other baseline algorithms.

Calculating the number of radial cracks around a wellbore fractured by liquid CO2 phase transition blasting technology

Integrating liquid CO_(2)phase transition blasting(LCPTB)technology with hydraulic fracturing(HF)methods can help reduce wellbore damage,create multiple radial fractures,and establish a complex fracture network.This approach significantly increases the recovery efficiency of low-permeability oil and gas fields.Accurately calculating the number of fractures caused by LCPTB is necessary to predict production enhancement effects and optimize subsequent HF designs.However,few studies are reported on large-scale physical model experiments in terms of a method for calculating the fracture number.This study analyzed the initiation and propagation of cracks under LCPTB,derived a calculation formula for crack propagation radius under stress waves,and then proposed a new,fast,and accurate method for calculating the fracture number using the principle of mass conservation.Through ten rock-breaking tests using LCPTB,the study confirmed the effectiveness of the proposed calculation approach and elucidated the variation rule of explosion pressure,rock-breaking scenario,and the impact of varying parameters on fracture number.The results show that the new calculation method is suitable for fracturing technologies with high pressure rates.Recommendations include enlarging the diameter of the fracturing tube and increasing the liquid CO2 mass in the tube to enhance fracture effectiveness.Moreover,the method can be applied to other fracturing technologies,such as explosive fracturing(EF)within HF formations,indicating its broader applicability and potential impact on optimizing unconventional resource extraction technologies.

Numerical and experimental investigation into the evolution of the shock wave when a muzzle jet impacts a constrained moving body

The gun-track launch system is a new special launch device that connects the track outside the muzzle.Because it is constrained by the track,the characteristics of development of the muzzle jet differ from those of the traditional muzzle jet.Specifically,it changes from freely developing to doing so in a constrained manner,where this results in an asymmetric direction of flow as well as spatio-temporal coupling-induced interference between various shock waves and the formation of vortices.In this background,the authors of this article formulate and consider the development and characteristics of evolution of the muzzle jet as it impacts a constrained moving body.We designed simulations to test the gun-track launch system,and established a numerical model based on the dynamic grid method to explore the development and characteristics of propagation of disturbances when the muzzle jet impacted a constrained moving body.We also considered models without a constrained track for the sake of comparison.The results showed that the muzzle jet assumed a circumferential asymmetric shape,and tended to develop in the area above the muzzle.Because the test platform was close to the ground,the muzzle jet was subjected to reflections from it that enhanced the development and evolution of various forms of shock waves and vortices in the muzzle jet to exacerbate its rate of distortion and asymmetric characteristics.This in turn led to significant differences in the changes in pressure at symmetric points that would otherwise have been identical.The results of a comparative analysis showed that the constrained track could hinder the influence of reflections from the ground on the muzzle jet to some extent,and could reduce the velocity of the shock waves inducing the motion of the muzzle as well as the Mach number of the moving body.The work here provides a theoretical basis and the requisite technical support for applications of the gun-track launch system.It also sheds light on the technical bottlenecks that need to be considered to recover high-value warheads.

A Flexible Multi-Layer Map Model Designed for Lane-Level Route Planning in Autonomous Vehicles

An increasing number of drivers are relying on digital map navigation systems in vehicles or mobile phones to select optimal driving routes in order to save time and improve safety. In the near future, digital map navigation systems are expected to play more important roles in transportation systems. In order to extend current navigation systems to more applications, two fundamental problems must be resolved: the lane-level map model and lane-level route planning. This study proposes solutions to both problems. The current limitation of the lane-level map model is not its accuracy but its flexibility;this study proposes a novel seven-layer map structure, called as Tsinghua map model, which is able to support autonomous driving in a flexible and efficient way. For lane-level route planning, we propose a hierarchical route-searching algorithm to accelerate the planning process, even in the presence of complicated lane networks. In addition, we model the travel costs allocated for lane-level road networks by analyzing vehicle maneuvers in traversing lanes, changing lanes, and turning at intersections. Tests were performed on both a grid network and a real lane-level road network to demonstrate the validity and efficiency of the proposed algorithm.

Early nasogastric enteral nutrition for severe acute pancreatitis: A systematic review

AIM: To evaluate the effectiveness and safety of early nasogastric enteral nutrition (NGEN) for patients with severe acute pancreatitis (SAP). METHODS: We searched Cochrane Central Register of Controlled Trials (Issue 2, 2006), Pub-Medline (1966-2006), and references from relevant articles. We included randomized controlled trials (RCTs) only, which reported the mortality of SAP patients at least. Two reviewers assessed the quality of each trial and collected data independently. The Cochrane Collaboration’s RevMan 4.2.9 software was used for statistical analysis. RESULTS: Three RCTs were included, involving 131 patients. The baselines of each trial were comparable. Meta-analysis showed no significant differences in mortality rate of SAP patients between nasogastric and conventional routes (RR = 0.76, 95% CI = 0.37 and 1.55, P = 0.45), and in other outcomes, including time of hospital stay (weighted mean difference = -5.87, 95% CI = -20.58 and 8.84, P = 0.43), complication rate of infection (RR = 1.41, 95% CI = 0.62 and 3.23, P = 0.41) or multiple organ defi ciency syndrome (RR = 0.97, 95% CI = 0.27 and 3.47, P = 0.97), rate of admission to ICU (RR = 1.00, 95% CI = 0.48 and 2.09, P = 0.99) or conversion to surgery (RR = 0.66, 95% CI = 0.12 and 3.69, P = 0.64), as well as recurrence of re-feeding pain and adverse events associated with nutrition. CONCLUSION: Early NGEN is a breakthrough in the management of SAP. Based on current studies, early NGEN appears effective and safe. Since the available evidence is poor in quantity, it is hard to make an accurate evaluation of the role of early NGEN in SAP.Before recommendation to clinical practice, further high qualified, large scale, randomized controlled trials are needed.

Cost-effectiveness analysis of chemotherapy for advancedgastric cancer in China

AIM： To assess the economics of various chemotherapeutic regimens for advanced gastric cancer （AGC）, and to select the best cost-effective regimen for the common Chinese patients. METHODS： Data source used in this study was the Chinese Biomedical Disk Database. Patients were diagnosed as AGC and any regimen was eligible. Outcome measures included median survival time （MST） and percentage of complete and partial response （CR＋PR）. Economic statistics was per capita direct medical cost （DMC） of a single cycle. TreeAge Pro Healthcare 2007 software was used to carry out costeffectiveness and incremental cost-effectiveness analysis. Sensitivity analyses were applied by altering willingness- to-pay and annual discount rate, and also re-analyzed by excluding the studies with apparent heterogeneity. RESULTS： Seven retrospective economics studies on 760 patients were included. S-fluorouracil-based regimens were universal, and also some new agents were involved, such as docetaxel, paclitaxel, andoxaliplatin. By processing analysis, we could recommend etoposide, leucovorin and 5-fluorouracil （ELF） regimen as preference, with a DMC/MST ratio of 2543 RBM/11.7 mo and a DMC/CR＋PR ratio of 2543 RMB/53.3%. Uraciltegafur, etoposide and cisplatin （FEP） or 5-fluorouracil, adrimycin/epirubin and mitomycin （FAM） regimens could be regarded as optional first-line chemotherapy for AGC in common Chinese patients. With no regard for willingness-to-pay, the docetaxel, cisplatin and 5-fluorouracil （DCF） regimen could be chosen as either a first- or a second-line chemotherapy, with a DMC/CR＋PR ratio of 9979 RMB/56.3%. CONCLUSION： 5-fluorouracial regimens are still considered the mainstream for AGC, while new agents such as taxanes are optional. More randomized clinical trials are required before any mandatory recommendation of certain regimens for patients with AGC in China is made.

Multiphase computed tomography radiomics of pancreatic intraductal papillary mucinous neoplasms to predict malignancy

BACKGROUND Intraductal papillary mucinous neoplasms(IPMNs)are non-invasive pancreatic precursor lesions that can potentially develop into invasive pancreatic ductal adenocarcinoma.Currently,the International Consensus Guidelines(ICG)for IPMNs provides the basis for evaluating suspected IPMNs on computed tomography(CT)imaging.Despite using the ICG,it remains challenging to accurately predict whether IPMNs harbor high grade or invasive disease which would warrant surgical resection.A supplementary quantitative radiological tool,radiomics,may improve diagnostic accuracy of radiological evaluation of IPMNs.We hypothesized that using CT whole lesion radiomics features in conjunction with the ICG could improve the diagnostic accuracy of predicting IPMN histology.AIM To evaluate whole lesion CT radiomic analysis of IPMNs for predicting malignant histology compared to International Consensus Guidelines.METHODS Fifty-one subjects who had pancreatic surgical resection at our institution with histology demonstrating IPMN and available preoperative CT imaging were included in this retrospective cohort.Whole lesion semi-automated segmentation was performed on each preoperative CT using Healthmyne software(Healthmyne,Madison,WI).Thirty-nine relevant radiomic features were extracted from each lesion on each available contrast phase.Univariate analysis of the 39 radiomics features was performed for each contrast phase and values were compared between malignant and benign IPMN groups using logistic regression.Conventional quantitative and qualitative CT measurements were also compared between groups,viaχ2(categorical)and Mann Whitney U(continuous)variables.RESULTS Twenty-nine subjects(15 males,age 71±9 years)with high grade or invasive tumor histology comprised the"malignant"cohort,while 22 subjects(11 males,age 70±7 years)with low grade tumor histology were included in the"benign"cohort.Radiomic analysis showed 18/39 precontrast,19/39 arterial phase,and 21/39 venous phase features differentiated malignant from benign IPMNs(P<0.05).Multivariate analysis including only ICG criteria yielded two significant variables:thickened and enhancing cyst wall and enhancing mural nodule<5 mm with an AUC(95%CI)of 0.817(0.709-0.926).Multivariable post contrast radiomics achieved an AUC(95%CI)of 0.87(0.767-0.974)for a model including arterial phase radiomics features and 0.834(0.716-0.953)for a model including venous phase radiomics features.Combined multivariable model including conventional variables and arterial phase radiomics features achieved an AUC(95%CI)of 0.93(0.85-1.0)with a 5-fold cross validation AUC of 0.90.CONCLUSION Multi-phase CT radiomics evaluation could play a role in improving predictive capability in diagnosing malignancy in IPMNs.Future larger studies may help determine the clinical significance of our findings.

Cost-effectiveness analysis of early veno-venous hemofiltration for severe acute pancreatitis in China

AIM： To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis （SAP） in China. METHODS： We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were： continuous or long-term veno-venous hemofiltration （CVVH/LVVH）, short-term veno-venous hemofiltration （SVVH）, SVVH plus peritoneal dialysis （PD）, and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed. RESULTS： The SVVH only technique was the least costly modality, $5809 （44449 RMB）, and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CWH/ LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio. CONCLUSION： The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.

Urinary trypsinogen-2 for diagnosing acute pancreatitis:a meta-analysis

BACKGROUND: Currently, serum amylase and lipase are the most popular laboratory markers for early diagnosis of acute pancreatitis with reasonable sensitivity and specificity. Urinary trypsinogen-2 (UT-2) has been increasingly used but its clinical value for the diagnosis of acute pancreatitis and post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis has not yet been systematically assessed. DATA SOURCES: A comprehensive search was carried out using PubMed (MEDLINE), Embase, and Web of Science for clinical trials, which studied the usefulness of UT-2 as a diagnostic marker for acute pancreatitis. Sensitivity, specificity and the diagnostic odds ratios (DORs) with 95% confidence interval (CI) were calculated for each study and were compared with serum amylase and lipase. Summary receiver-operating curves were conducted and the area under the curve (AUC) was evaluated. RESULTS: A total of 18 studies were included. The pooled sensitivity and specificity of UT-2 for the diagnosis of acute pancreatitis were 80% and 92%, respectively (AUC=0.96, DOR=65.63, 95% CI: 31.65-139.09). The diagnostic value of UT-2 was comparable to serum amylase but was weaker than serum lipase. The pooled sensitivity and specificity for the diagnosis of post-ERCP pancreatitis were 86% and 94%, respectively (AUC=0.92, DOR=77.68, 95% CI: 24.99-241.48).CONCLUSIONS: UT-2 as a rapid test could be potentially used for the diagnosis of post-ERCP pancreatitis and to an extent, acute pancreatitis. Further studies are warranted to confirm these results.

Attacks and defences on intelligent connected vehicles:a survey

Intelligent vehicles are advancing at a fast speed with the improvement of automation and connectivity,which opens up new possibilities for different cyber-attacks,including in-vehicle attacks(e.g.,hijacking attacks)and vehicle-to-everything communicationattacks(e.g.,data theft).These problems are becoming increasingly serious with the development of 4G LTE and 5G communication technologies.Although many efforts are made to improve the resilience to cyber attacks,there are still many unsolved challenges.This paper first identifies some major security attacks on intelligent connected vehicles.Then,we investigate and summarize the available defences against these attacks and classify them into four categories:cryptography,network security,software vulnerability detection,and malware detection.Remaining challenges and future directions for preventing attacks on intelligent vehicle systems have been discussed as well.

Fundamental aspects in CO_(2) electroreduction reaction and solutions from in situ vibrational spectroscopies

Using renewable energy to drive carbon dioxide reduction reaction(CO_(2)RR)electrochemically into chemicals with high energy density is an efficient way to achieve carbon neutrality,where the effective utilization of CO_(2) and the storage of renewable energy are realized.The reactivity and selectivity of CO_(2)RR depend on the structure and composition of the catalyst,applied potential,electrolyte,and pH of the solution.Besides,multiple electron and proton transfer steps are involved in CO_(2)RR,making the reaction pathways even more complicated.In pursuit of molecular-level insights into the CO_(2)RR processes,in situ vibrational methods including infrared,Raman and sum frequency generation spectroscopies have been deployed to monitor the dynamic evolution of catalyst structure,to identify reactive intermediates as well as to investigate the effect of local reaction environment on CO_(2)RR performance.This review summarizes key findings from recent electrochemical vibrational spectrosopic studies of CO_(2)RR in addressing the following issues:the CO_(2)RR mechanisms of different pathways,the role of surface-bound CO species,the compositional and structural effects of catalysts and electrolytes on CO_(2)RR activity and selectivity.Our perspectives on developing high sensitivity wide-frequency infrared spectroscopy,coupling different spectroelectrochemical methods and implementing operando vibrational spectroscopies to tackle the CO_(2)RR process in pilot reactors are offered at the end.

Present and future of prophylactic antibiotics for severe acute pancreatitis

AIM: To investigate the role of prophylactic antibiotics in the reduction of mortality of severe acute pancreatitis (SAP) patients, which is highly questioned by more and more randomized controlled trials (RCTs) and metaanalyses. METHODS: An updated meta-analysis was performed. RCTs comparing prophylactic antibiotics for SAP with control or placebo were included for meta-analysis. The mortality outcomes were pooled for estimation, and re-pooled estimation was performed by the sensitivity analysis of an ideal large-scale RCT. RESULTS: Currently available 11 RCTs were included. Subgroup analysis showed that there was significant reduction of mortality rate in the period before 2000, while no significant reduction in the period from 2000 [Risk Ratio, (RR ) = 1.01, P = 0.98]. Funnel plot indi-cated that there might be apparent publication bias in the period before 2000. Sensitivity analysis showed that the RR of mortality rate ranged from 0.77 to 1.00 with a relatively narrow confidence interval (P < 0.05). However, the number needed to treat having a minor lower limit of the range (7-5096 patients) implied that certain SAP patients could still potentially prevent death by antibiotic prophylaxis. CONCLUSION: Current evidences do not support prophylactic antibiotics as a routine treatment for SAP, but the potentially benefited sub-population requires further investigations.

Insight into the behavior at the hygroscopicity and interface of the hydrophobic imidazolium-based ionic liquids

How to completely remove the water from ionic liquids(ILs)is difficult for researchers because of the hygroscopicity of ILs.In order to study the hygroscopicity of ILs,two kinds of ILs,1-Butyl-3-methylimidazolium hexafluorophosphate([Bmim][PF6])and 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)([Bmim][NTf_(2)])were investigated by molecular dynamics simulations.Although[Bmim][PF6]and[Bmim][NTf_(2)]are hydrophobic,both of the ILs could absorb water molecules from the vapor.In this work,the process of absorbing water from the vapor phase was studied,and the water molecules could disperse into the IL.Aggregation was observed with increasing the water concentration.Although the absorbed water increases obviously,the amount of free water and small cluster in the ILs does not change significantly and always stays at a certain level.The amount of free water and small cluster in[Bmim][PF6]is more than that in[Bmim][NTf_(2)],which is consistent with their hydrophobicity.In addition,the liquid-vacuum and liquid–liquid interfaces of the ILs were simulated and analyzed in detail.The number density distribution and angle distribution indicated that[Bmim]+cations arrangement regularly at the IL-vacuum interface.The butyl chain point to the vacuum,while the imidazlium ring is close to the IL phase region and perpendicular to the interface.While at the IL-water interface,the cations and anions are disordered.

Gradient structure induced simultaneous enhancement of strength and ductility in AZ31 Mg alloy with twin-twin interactions

Gradient nanostructure was introduced to enhance the strength and ductility via deformation incompatibility accommodated by geometrical necessary dislocations for most metallic materials recently.However,few intensive researches were carried out to investigate the effect of gradient structure on the deformation twin evolution and resulting performance improvements.In the present paper,we produced gradient-structured AZ31 Mg alloy with fine-grain layers,parallel twin laminates and a coarse-grain core from two upmost surfaces to the center of plate.Surprisingly,this architected Mg alloy exhibited simultaneous enhancement of strength and ductility.Subsequent microstructural observations demonstrated that abundant twin-twin interactions resulting from higher strength and multi-axial stress state could make great contributions to the increase of work-hardening capability.This was further proved by the measurement of full-field strain evolution during the plastic deformation.Such a design strategy may provide a new path for producing advanced structure materials in which the deformation twinning works as one of the dominant plasticity mechanisms.

A pilot study of radiologic measures of abdominal adiposity:weighty contributors to early pancreatic carcinogenesis worth evaluating?

Objective:Intra-abdominal fat is a risk factor for pancreatic cancer(PC),but little is known about its contribution to PC precursors known as intraductal papillary mucinous neoplasms(IPMNs).Our goal was to evaluate quantitative radiologic measures of abdominal/visceral obesity as possible diagnostic markers of IPMN severity/pathology.Methods:In a cohort of 34 surgically-resected,pathologically-confirmed IPMNs(17 benign;17 malignant) with preoperative abdominal computed tomography(CT) images,we calculated body mass index(BMI) and four radiologic measures of obesity:total abdominal fat(TAF) area,visceral fat area(VFA),subcutaneous fat area(SFA),and visceral to subcutaneous fat ratio(V/S).Measures were compared between groups using Wilcoxon two-sample exact tests and other metrics.Results:Mean BMI for individuals with malignant IPMNs(28.9 kg/m^2) was higher than mean BMI for those with benign IPMNs(25.8 kg/m^2)(P=0.045).Mean VFA was higher for patients with malignant IPMNs(199.3 cm^2) compared to benign IPMNs(120.4cm^2),P=0.092.V/S was significantly higher(P=0.013) for patients with malignant versus benign IPMNs(1.25 vs.0.69 cm^2),especially among females.The accuracy,sensitivity,specificity,and positive and negative predictive value of V/S in predicting malignant IPMN pathology were 74%,71%,76%,75%,and 72%,respectively.Conclusions:Preliminary findings suggest measures of visceral fat from routine medical images may help predict IPMN pathology,acting as potential noninvasive diagnostic adjuncts for management and targets for intervention that may be more biologically-relevant than BMI.Further investigation of gender-specific associations in larger,prospective IPMN cohorts is warranted to validate and expand upon these observations.

Facile synthesis of colloidal nitrogen-doped titanium carbide sheets with enhanced electrochemical performance

Heteroatom nitrogen doping in two-dimensional transition metal carbides,known as MXenes,has been considered as a promising strategy for modulating their electronic structure and electrochemical reactivity.While hightemperature annealing in the presence of a nitrogen source has been one popular method to introduce nitrogen,annealing exfoliated multilayered MXenes typically brings about incomplete delamination and the treatment of delaminated monolayer MXenes often leads to irreversible restacking.Here,starting from the typical carbide precursor,we developed an aqueous colloid containing monolayered nitrogen-doped titanium carbide sheets with excellent dispersity and stability.This achievement is critically dependent on the retaining of the hydrophilic surface of host layers during annealing treatment.The successful realization of nitrogen doping into individual MXene monolayers resulted in enhanced electrical conductivity and redox reactivity,for which the sample exhibited excellent capacitive electrochemical performance(586 F/g at a scan rate of 5mV/s)and cycling stability(capacitance retention of 96.2%after 104 cycles at 5 A/g).This paper presents a feasible and simple strategy for designing nitrogen-doped MXenes colloid,the realization of which promises its facile uses in liquid phase engineering techniques toward versatile applications.