Outstanding Humidity Chemiresistors Based on Imine-Linked Covalent Organic Framework Films for Human Respiration Monitoring

Human metabolite moisture detection is important in health monitoring and non-invasive diagnosis.However,ultra-sensitive quantitative extraction of respiration information in real-time remains a great challenge.Herein,chemiresistors based on imine-linked covalent organic framework(COF)films with dual-active sites are fabricated to address this issue,which demonstrates an amplified humidity-sensing signal performance.By regulation of monomers and functional groups,these COF films can be pre-engineered to achieve high response,wide detection range,fast response,and recovery time.Under the condition of relative humidity ranging from 13 to 98%,the COFTAPB-DHTA film-based humidity sensor exhibits outstanding humidity sensing perfor-mance with an expanded response value of 390 times.Furthermore,the response values of the COF film-based sensor are highly linear to the relative humidity in the range below 60%,reflecting a quantitative sensing mechanism at the molecular level.Based on the dual-site adsorption of the(-C=N-)and(C-N)stretching vibrations,the revers-ible tautomerism induced by hydrogen bonding with water molecules is demonstrated to be the main intrinsic mechanism for this effective humidity detection.In addition,the synthesized COF films can be further exploited to effectively detect human nasal and oral breathing as well as fabric permeability,which will inspire novel designs for effective humidity-detection devices.

Metformin accelerates bone fracture healing by promoting type H vessel formation through inhibition of YAP1/TAZ expression

Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.

Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China

Machine learning is currently one of the research hotspots in the field of landslide prediction.To clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility evaluation.The evaluation factors were selected by using correlation analysis and variance expansion factor method.Applying four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were constructed.Comparative analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)curves.The results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,respectively.XGB model had the highest predictive ability,followed by RF model,SVM model,and LR model.The frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,respectively.RF and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems.

Highly Sensitive Ammonia Gas Sensors at Room Temperature Based on the Catalytic Mechanism of N,C Coordinated Ni Single-Atom Active Center

Significant challenges are posed by the limitations of gas sensing mechanisms for trace-level detection of ammonia(NH3).In this study,we propose to exploit single-atom catalytic activation and targeted adsorption properties to achieve highly sensitive and selective NH3 gas detection.Specifically,Ni singleatom active sites based on N,C coordination(Ni-N-C)were interfacially confined on the surface of two-dimensional(2D)MXene nanosheets(Ni-N-C/Ti_(3)C_(2)Tx),and a fully flexible gas sensor(MNPE-Ni-N-C/Ti_(3)C_(2)Tx)was integrated.The sensor demonstrates a remarkable response value to 5 ppm NH3(27.3%),excellent selectivity for NH3,and a low theoretical detection limit of 12.1 ppb.Simulation analysis by density functional calculation reveals that the Ni single-atom center with N,C coordination exhibits specific targeted adsorption properties for NH3.Additionally,its catalytic activation effect effectively reduces the Gibbs free energy of the sensing elemental reaction,while its electronic structure promotes the spill-over effect of reactive oxygen species at the gas-solid interface.The sensor has a dual-channel sensing mechanism of both chemical and electronic sensitization,which facilitates efficient electron transfer to the 2D MXene conductive network,resulting in the formation of the NH3 gas molecule sensing signal.Furthermore,the passivation of MXene edge defects by a conjugated hydrogen bond network enhances the long-term stability of MXene-based electrodes under high humidity conditions.This work achieves highly sensitive room-temperature NH3 gas detection based on the catalytic mechanism of Ni single-atom active center with N,C coordination,which provides a novel gas sensing mechanism for room-temperature trace gas detection research.

Hyperthyroidism and severe bradycardia:Report of three cases and review of the literature

BACKGROUND Hyperthyroidism often leads to tachycardia,but there are also sporadic reports of hyperthyroidism with severe bradycardia,such as sick sinus syndrome(SSS)and atrioventricular block.These disorders are a challenge for clinicians.CASE SUMMARY We describe three cases of hyperthyroidism with SSS and found 31 similar cases in a PubMed literature search.Through the analysis of these 34 cases,we found 21 cases of atrioventricular block and 13 cases of SSS,with 67.6%of the patients experiencing bradycardia symptoms.After drug treatment,temporary pacemaker implantation,or anti-hyperthyroidism treatment,the bradycardia of 27 patients(79.4%)was relieved,and the median recovery time was 5.5(2-8)d.Only 7 cases(20.6%)needed permanent pacemaker implantation.CONCLUSION Patients with hyperthyroidism should be aware of the risk of severe bradycardia.In most cases,drug treatment or temporary pacemaker placement is recommended for initial treatment.If the bradycardia does not improve after 1 wk,a permanent pacemaker should be implanted.

新型负压吸引经尿道输尿管一体硬镜碎石术的临床应用研究

目的探究新型负压吸引经尿道输尿管一体硬镜碎石术在输尿管结石疾病中的效果及临床价值。方法选取2018年5月—2019年10月在赣州市人民医院泌尿外科行输尿管结石手术的患者157例,随机分为A组53例、B组46例及C组58例。A组采用传统经尿道输尿管硬镜碎石术,B组采用带鞘负压吸引经尿道输尿管硬镜碎石术,C组采用新型负压吸引经尿道输尿管一体硬镜碎石术。比较3组患者的术前资料、一期手术成功率、手术时间、住院时间、术后30 d清石率、并发症Clavien系统分级等情况。结果 144例经尿道输尿管镜碎石手术一期完成,其余13例因输尿管狭小无法上鞘或进镜改为其他手术方式。3组患者的术前资料比较差异无统计学意义(P>0.05);一期手术成功率B组低于A、C组(P <0.05);手术时间C组较A、B组短(P <0.05),住院时间C组较A、B组少(P <0.05);术后30天清石率A组低于B、C组(P <0.05);A、B、C组患者总并发症发生率差异无统计学意义(P>0.05)。结论新型负压吸引经尿道输尿管一体硬镜碎石术比其余两种具有一定的优势,能降低患者手术时间和住院时间,具有较好的临床价值,值得推广。

Microstructure,microhardness and corrosion resistance of laser cladding Ni−WC coating on AlSi5Cu1Mg alloy

The microstructure,microhardness,and corrosion resistance of laser cladding Ni−WC coating on the surface of AlSi5Cu1Mg alloy were investigated by scanning electron microscopy,X-ray diffraction,microhardness testing,immersion corrosion testing,and electrochemical measurement.The results show that a smooth coating containing NiAl,Ni_(3)Al,M_(7)C_(3),M_(23)C_(6)phases(M=Ni,Al,Cr,W,Fe)and WC particles is prepared by laser cladding.Under a laser scanning speed of 120 mm/min,the microhardness of the cladding coating is 9−11 times that of AlSi5Cu1Mg,due to the synergistic effect of excellent metallurgical bond and newly formed carbides.The Ni−WC coating shows higher corrosion potential(−318.09 mV)and lower corrosion current density(12.33μA/cm^(2))compared with the matrix.The crack-free,dense cladding coating obviously inhibits the penetration of Cl^(−)and H^(+),leading to the remarkedly improved corrosion resistance of cladding coating.

A Novel Artificial Neuron-Like Gas Sensor Constructed from CuS Quantum Dots/Bi2S3 Nanosheets

Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.

应用自制清石鞘行微造瘘经皮肾镜一期治疗上尿路结石合并同侧单纯性肾囊肿的临床效果分析

目的探讨应用自制可吸引金属清石鞘行微造瘘经皮肾镜一期治疗泌尿系结石合并单纯性肾囊肿的安全性及有效性。方法回顾性分析该院2012年5月-2015年6月收治的单纯性肾囊肿并同侧泌尿系结石的36例患者行微造瘘经皮肾镜手术的临床数据,评价该手术方式的治疗效果。结果所有患者均成功建立经皮肾镜通道,其中单通道30例,双通道6例;手术时间为48～96 min,平均(68.5±5.3)min;术后3例患者出现发热,予以对症治疗后治愈;1例患者出现肾动脉出血,予以高选择性肾动脉栓塞治疗后痊愈。术后复查CT结果显示,36例患者肾囊肿均一期成功处理,34例患者结石取净,另外2例鹿角型结石患者术后仍有较多结石残留,采用2期微造瘘经皮肾镜吸引取石术治疗。结论应用自制金属清石鞘行微造瘘经皮肾镜一期治疗泌尿系结石合并同侧单纯性肾囊肿是一种安全、有效、经济的手术方式。

Lateral position intubation followed by endoscopic ultrasoundguided angiotherapy in acute esophageal variceal rupture: A case report

BACKGROUND Massive esophageal variceal bleeding can be catastrophic,leading to high morbidity and mortality.Patients experiencing massive esophageal variceal bleeding are at high risk of aspiration and hemorrhagic shock in acute episodes.Intubation and bleeding control are the two essential steps for resuscitation of these patients.CASE SUMMARY A 47-year-old male patient was admitted to our hospital with upper digestive tract bleeding.He was diagnosed with alcohol-induced liver cirrhosis and consequent esophagogastric varices.As he did not show a good response to somatostatin and Sengstaken-Blakemore tube placement,the patient was scheduled for endoscopic angiotherapy under anesthesia.Preoperative assessment showed an ASA physical status of III and Child-Pugh classification B.However,massive hemorrhage occurred just after induction of anesthesia.Intubation by video-guided laryngoscopy in the lateral decubitus position was attempted twice and was successful.After that,an experienced endoscopic ultrasound(EUS)specialist performed angiotherapy and occluded the culprit vessel.An ultra-thin gastroscope was then inserted into the endotracheal tube to extract the blood observed in the lobar bronchi.The patient suffered hemorrhagic shock with an estimated blood loss of 1500 mL in 20 min and remained in the intensive care unit for two days.The patient was discharged from our hospital eight days later without major complications.CONCLUSION Intubation in the lateral decubitus position and EUS-guided treatment can be lifesaving procedures in patients with massive upper gastrointestinal hemorrhage.

First Principles Study of AI-Li Intermetallic Compounds

The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary A1-Li intermetallics, A13Li, A1Li, A12Li3, and A14Li9, are ana- lyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between A1 and Li for all the A1-Li intermetallics. In partic- ular, in the Li-rich A1-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration of.Li. According to the computational single crystal elastic constants, all the four A1-Li intermetallic compounds considered here are mechani- cally stable. The polycrystalline elastic modulus and Poisson＇s ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary A1-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of A1-Li intermetallics decreases in a linear manner.

Energy-Efficient Sensing and Transmission for Multi-Hop Relay Cognitive Radio Sensor Networks

How to achieve transmissions in an energy-efficient way in multi-hop decode and forward(DF) relay cognitive radio sensor networks(CRSNs) is important since sensor nodes in CRSNs are usually battery powered. This paper aims to maximize energy efficiency(EE) by joint optimizing sensing time and power allocation in multi-channels & multihops DF relay CRSNs under constraints on outage probability and sensing performance. First, we design a channel selection scheme for sensing according to the available probabilities of multi channels. Second, we analyze the expected throughput and energy consumption and formulate the EE problem as a concave/concave fractional program. Third, coordinate ascent and Charnes-Cooper Transformation(CCT) methods are used to transform the nonlinear fractional problem into an equivalent concave problem. Subsequently, the closed form of outage probability is derived and the convergence rate of the iterative algorithm is analyzed. Finally, simulation results show that the proposed scheme can achieve effective EE.

Creation and erasure of polar bubble domains in PbTiO_(3)films by mechanical stress and light illuminations

The controllable manipulation of polar topological structures(e.g.skyrmion bubble)in ferroelectric materials have been considered as a cornerstone for future programmable nano-electronics.Here,we present the effective creation and erasure of polar bubble states PbTiO_(3)(PTO)multilayers trigged by mechanical stress and light illumination,respectively.It was found that applying atomic force microscope(AFM)tip force can induced formation of nanoscale bubble domains from the initial monodomain state.Moreover,the created bubble domain can be eliminated by exposure to ultraviolet or infrared light illumination.The above results can be understood by modulation of depolarization screening charges and bias fields,as reflected by scanning Kelvin potential microscopic(SKPM)observations,whereby the flexoelectric effect from the tip force tends to remove the screening charges on top surface and modulate the bias field that favors the formation of bubble state while light illumination tends to recover the screen charges and favor the monodomain state.The results provide a good example for multi-field manipulation of polar topologies,which might create a new avenue towards the immerging new concept electronic devices.

Endothelial surface glycocalyx and vascular mechano-sensing and transduction

Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system.In addition to forming a transport barrier between the blood and vessel wall,vascular ECs play important roles in regulating circulation functions.Besides biochemical stimuli,blood flow induced(hemodynamic)mechanical stimuli,such as shear stress,pressure and circumferential stretch,modulate EC morphology and functions by activating mechanosensors,signaling pathways,and gene and protein expressions.The EC responses to the hemodynamic forces(mechano-sensing and transduction)

Viral respiratory infection,a risk in post-pediatric cardiac surgery:a propensity-matched analysis

Objective To define risk stratification and guide optimal surgical timing of perioperative viral respiratory infection(VRI)in children with cardiac surgery.Methods Retrospective study with propensity score-matched analysis.A total of 2,831 patients had performed RespPCR testing,and finally there were 2,740 negative RespPCR patients and 91 positive RespPCR patients.

Early vasopressin initiation for pediatric patients with vasodilatory shock after cardiac surgery

Objective Vasopressin has showed a beneficial use in pediatric patients with vasodilatory shock after cardiac surgery. However, the optimal timing of vasopressin initiation has not been investigated.Our aim was to evaluate the effect of early vasopressin initiation for these patients.

Sr-doping effects on conductivity,charge transport,and ferroelectricity of Ba_(0.7)La_(0.3)TiO_(3) epitaxial thin films

Sr-doped Ba_(0.7)La_(0.3)TiO_(3)(BSLTO)thin films are deposited by pulsed laser deposition,and their microstructure,conductivity,carrier transport mechanism,and ferroelectricity are systematically investigated.The x-ray diffraction measurements demonstrate that Sr-doping reduces the lattice constant of BSLTO thin films,resulting in the enhanced phonon energy in the films as evidenced by the Raman measurements.Resistivity-temperature and Hall effect measurements demonstrate that Sr can gradually reduce electrical resistivity while the electron concentration remains almost unchanged at high temperatures.For the films with semiconducting behavior,the charge transport model transforms from variable range hopping to small polaron hopping as the measurement temperature increases.The metalic conductive behaviors in the films with Sr=0.30,0.40 conform to thermal phonon scattering mode.The difference in charge transport behavior dependent on the A-site cation doping,is clarified.It is revealed that the increasing of phonon energy by Sr doping is responsible for lower activation energy of small polaron hopping,higher carrier mobility,and lower electrical resistivity.Interestingly,the piezoelectric force microscopy(PFM)results demonstrate that all the BSLTO films can exhibit ferroelectricity,especially for the room temperature metallic conduction film with Sr=0.40.These results imply that Sr-doping could be a potential way to explore ferroelectric metal materials for other perovskite oxides.

Antibody and complement levels in patients with hypersplenism associated with cirrhotic portal hypertension and therapeutic principles

BACKGROUND Hypersplenism associated with cirrhotic portal hypertension is a common condition often resulting from hepatitis B-related cirrhosis.However,the levels of immunoglobulin(Ig)and complement in patients with hypersplenism associated with cirrhotic portal hypertension remain unclear.This study was undertaken to determine the levels of Ig and complement in these patients,the relationship between these levels and Child-Pugh class and their clinical significance.AIM To investigate the antibody(Ig)and complement levels in patients with hypersplenism associated with cirrhotic portal hypertension and their clinical significance.METHODS Clinical data of 119 patients with hypersplenism associated with cirrhotic portal hypertension were statistically analyzed and compared with those of 128 control patients.RESULTS IgA and IgG levels in patients with hypersplenism were significantly higher than controls(P<0.001).There was no significant difference in IgM between the two groups(P=0.109).C3 and C4 levels in patients with hypersplenism were significantly lower than controls(P<0.001).As liver function decreased,IgA and IgG levels increased(P<0.001),and C3 and C4 levels decreased(P<0.001).CONCLUSION Patients with hypersplenism associated with cirrhotic portal hypertension have significantly higher antibody(IgA and IgG)levels and significantly lower complement(C3 and C4)levels,which are both related to liver damage.Clinically,the administration of anti-hepatitis virus agents and protection of liver function should be strengthened.

Disulfiram:A novel repurposed drug for cancer therapy

Cancer is a major global health issue.Effective therapeutic strategies can prolong patients’survival and reduce the costs of treatment.Drug repurposing,which identifies new therapeutic uses for approved drugs,is a promising approach with the advantages of reducing research costs,shortening development time,and increasing efficiency and safety.Disulfiram(DSF),a Food and Drug Administration(FDA)-approved drug used to treat chronic alcoholism,has a great potential as an anticancer drug by targeting diverse human malignancies.Several studies show the antitumor effects of DSF,particularly the combination of DSF and copper(DSF/Cu),on a wide range of cancers such as glioblastoma(GBM),breast cancer,liver cancer,pancreatic cancer,and melanoma.In this review,we summarize the antitumor mechanisms of DSF/Cu,including induction of intracellular reactive oxygen species(ROS)and various cell death signaling pathways,and inhibition of proteasome activity,as well as inhibition of nuclear factor-kappa B(NF-κB)signaling.Furthermore,we highlight the ability of DSF/Cu to target cancer stem cells(CSCs),which provides a new approach to prevent tumor recurrence and metastasis.Strikingly,DSF/Cu inhibits several molecular targets associated with drug resistance,and therefore it is becoming a novel option to increase the sensitivity of chemo-resistant and radio-resistant patients.Studies of DSF/Cu may shed light on its improved application to clinical tumor treatment.

Boost VS_(2) electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium-ion storage

Vanadium disulfide(VS_(2)) as a typical two-dimensional transition metal chalcogenide has excellent competitiveness for sodium-ion storage due to its wide layer spacing(0.575 nm),high theoretical capacity of 932mAh·g^(-1) originating from multi-electron electrochemical redox.However,continuous sodiation process accompanied by crystal structural evolution and collapse cause rapid capacity decaying.Herein,novel few-layer VS_(2)nanosheets with open(001) crystal planes are in-situ constructed on reduced graphene oxide to solve these issues mentioned above.It indicates that few-layer VS_(2)provides more Na^(+) storage activity due to the low Na^(+)surface migration energy barrier on exposed crystal(001)planes.The flexible and high electronic conductivity of carbon matrix also effectively builds multi-level buffer structure and electron transport kinetics to boost the Na^(+)insertion/conversion reactive activity on VS_(2) as well as Na^(+) pseudocapacitance storage kinetics on edges and defects of nano sheets.Those coupling effects result in high rate capability and long cycling stability as a battery/capacitor anode.It delivers conspicuous high energy density of 81 and 40 Wh·kg^(-1) at power density of 118 and 10,286W·kg^(-1),as well as 80% energy retention rate after 5000cycles,confirming its great application potential in sodiumbased storage devices.