Building a Sustainable Learning Cycle:The Role of‘the Formative Use of Summative Tests’(FUST)in Promoting Students’Developments

The study employed a descriptive mixed-methods qualitative case study approach.Material and interview-based data were collected from two EFL classes in a private international school in central China.Findings from RQ1 suggest that teacher-made summative tests were largely dependable to the extent that the tests reflect the syllabus-based construct and address students’affective factors.Findings from RQ2 suggest that facilitating factors including in-school continuous professional development(CPD)and teacher collegiality practices may enhance FUST’s prospective role.

Clinical value of contrast-enhanced ultrasound in improving diagnostic accuracy rate of transthoracic biopsy of anteriormedial mediastinal lesions

Objective： To evaluate the clinical value of contrast-enhanced ultrasound（CEUS） in transthoracic biopsy of anterior-medial mediastinal lesions.Methods： A total of 123 patients with anterior or middle mediastinum lesions required ultrasound guided transthoracic biopsy for pathological diagnosis. Among them, 72 patients received CEUS examinations before biopsy. After CEUS, 8 patients were excluded from biopsy and the rest 64 patients underwent biopsy（CEUS group）. During the same period, 51 patients received biopsy without CEUS examination（US group）. The ultrasonography characteristics, the number of biopsy puncture attempts, diagnostic accuracy rate and the incidence of complications were recorded and compared between the two groups.Results： A large portion of necrosis area or superficial large vessels was found in 8 patients, so the biopsy was cancelled. The internal necrosis was demonstrated in 43.8% of the lesions in CEUS group and in 11.8% of US group（P0.001）. For thymic carcinoma, CEUS increased the detection rate of internal necrosis and pericardial effusion than conventional ultrasound（62.5% vs. 18.8%, P=0.012; 56.3% vs. 12.5%, P=0.023）. The average number of punctures in CEUS group and US group was 2.36±0.70 and 2.21±0.51 times, respectively（P0.05）. The diagnostic accuracy rate of biopsy in CEUS group（96.9%, 62/64） was significantly higher than that in US group（84.3%, 43/51）（P=0.022）. In US group, 2 patients suffered from mediastinal bleeding（3.9%）, while no major complications occurred in CEUS group.Conclusions： CEUS examination provided important information before transthoracic mediastinum biopsy and improved diagnostic accuracy rate in biopsy of anterior and middle mediastinum lesions than conventional ultrasound.

Heat shock protein inhibitor, quercetin, as a novel adjuvant agent to improve radiofrequency ablation-induced tumor destruction and its molecular mechanism

Background： We investigated the effect of a small molecular inhibitor of heat shock protein （HSP）, qnercetin, on tumor radiofrequency （RF） ablation, and explored the underlying molecular mechanisms. Methods： In in vivo study, rats with R3230 breast adenocarcinoma were sacrificed 24 h post-treatment and gross coagulation areas were compared, and next, randomized into four treatment arms （control, quercetin alone, RF alone, and combination） for Kaplan-Meier analysis of defined endpoint survival. Then the distribution and expression levels of heat shock protein 70 （HSP70）, cleaved caspase-3 and heat shock factor 1 （HSF1） were analyzed after different treatments. In in vitro study, we used quercetin to promote SK- HEP-I （hepatic） and MCF-7 （breast） cancer cell apoptosis in heat shock cell model, and siRNA was used to block c-Jun and to explore the role of activating protein-1 （AP-1） signaling pathways. Results： We found the effects of quercetin plus RFA resulted in increase on the tumor destruction/ endpoint survival （26.5±3.4 d） in vivo, compared with RF alone （17.6±2.5 d） and quercetin alone （15.7±3.1 d）. Most importantly, quercetin-induced cancer cell death required the presence of HSF1 in animal model. Furthermore, quercetin directly down-regulated expression of HSF1 in vitro, which our findings have revealed, required the activation of AP-1 signaling pathways by loss-of-function analysis using siRNA mediated targeting of c-Jun. Conclusions： These results indicated a protective role of quercetin in tumor ablation and highlighted a novel mechanism involving HSP70 with HSF1 pathway in thermal ablation of solid tumors.

Preventive strategies for feeding intolerance among patients with severe traumatic brain injury:A cross-sectional survey

This study aimed to investigate the application status of preventive measures for feeding intolerance in patients with severe traumatic brain injury(STBI)in China and analysis the differences and their causes.Methods A cross-sectional survey was conducted.From December 2019 to January 2020,ICU nurses and physicians of 89 hospitals in China were surveyed by using a questionnaire on preventive strategies for feeding intolerance in patients with STBI.The questionnaire included two parts:the general information of participants(10 items)and application of preventive measures for feeding intolerance in STBI patients(18 items).Results Totally 996 nurses and physicians completed the questionnaire.Among various methods,gastrointestinal symptoms(85.0%)and injury severity(71.4%)were mostly used to assess gastrointestinal functions and risk of feeding intolerance among STBI patients,respectively.Initiating enteral nutrition(EN)within 24–48 h(61.5%),nasogastric tubes(91.2%),30°–45°of head-of-bed elevation(89.5%),continuous feeding by pump(72.9%),EN solution temperature of 38–40°C(65.5%),<500 ml initial volume of EN solution(50.0%),monitoring gastric residual volume with a syringe(93.7%),and assessing gastric residual volume every 4 h(51.5%)were mostly applied for EN delivery among STBI patients.Prokinetic agents(73.3%),enema(73.6%),probiotics(79.0%),antacid agents(84.1%),and non-nutritional preparations as initial EN formula(65.6%)were commonly used for preventing feeding intolerance among STBI patients.Conclusions The survey showed that nurses and clinicians in China have a positive attitude towards preventive strategies for feeding intolerance.However,some effective new technologies and methods have not been timely applied in clinical practice.We suggest that managers,researchers,clinicians,nurses,and other health professionals should collaborate to explore effective and standard preventive strategies for feeding intolerance among patients with STBI.

丁苯橡胶对竹粉/高密度聚乙烯复合材料冲蚀磨损特性的影响

为制备适用于海岸工程领域的高耐冲蚀型木塑复合材料,基于旋转射流技术研究了丁苯橡胶(SBR)对竹粉/高密度聚乙烯(HDPE)复合材料冲蚀磨损特性的影响。结果表明,引入SBR可以提升竹粉/HDPE复合材料的硬度和冲击强度(硬度最大增幅1.3%、冲击强度最大增幅18.8%),并优化竹粉/HDPE复合材料中纤维和基体的两相界面质量。较之未引入SBR的竹粉/HDPE复合材料,引入SBR的竹粉/HDPE复合材料的抗冲蚀性显著提升,其最大冲蚀率发生于冲蚀靶距1.0 cm和冲蚀时间180 s处。较之未冲蚀面,竹粉/HDPE复合材料冲蚀面主要表现出纤维破碎和基体脆性断裂,以及氧含量相对增加和羟基伸缩振动加强等磨损特征。引入SBR不改变旋转射流对竹粉/HDPE复合材料的冲蚀机理。

A nonlinear triboelectric nanogenerator with a broadened band-width for effective harvesting of vibration energy

A narrow resonance bandwidth of an energy harvesters limits its response to the wide frequency spectrum in ambient environ-ments.This work proposes an addition of a nonlinear restoring force applied to a triboelectric nanogenerator(TENG)to tune and broaden the resonance bandwidth.This restoring force is applied by permanent magnets at both sides of the slider and two external magnets.The noncontact strategy is adopted between the slider and the grating electrodes to avoid the wear of electrodes and energy loss caused by friction.The results show that compared with the linear system,the nonlinear noncontact TENG(NN-TENG)can increase the peak current from 6.3μA to 7.89μA,with an increment of about 25%,increase the peak power from 650μW to 977μW,increasing by about 50%,and increase the bandwidth from 0.5 Hz to 7.75 Hz,increasing by about1400%.This work may enable a new strategy to boost the bandwidth and output power of TENG through nonlinear oscillators.

Evolution mechanism and quantitative characterization of initial micro-cracks in marble under triaxial compression

The initial micro-cracks affect the evolution characteristics of macroscopic deformation and failure of rock but are often ignored in theoretical calculation,numerical simulation,and mechanical experiments.In this study,we propose a quantitative analysis model to investigate the effects of initial micro-cracks on the evolution of marble deformation and failure.The relationship between the micro-crack propagation and the marble failure characteristics was comprehensively studied by combining theoretical analysis with a micro-computed tomography(micro-CT)scanning technique.We found that with the increase of confining pressure,the matrix elastic modulus of the marble first increased and then tended to be stable,while the micro-cracks increased exponentially.The sensitivity ranges of the marble sample matrix elastic modulus and micro-cracks to confining pressure were 0–30 MPa and 30–50 MPa,respectively.The porosity and Poisson’s ratio decreased exponentially.The increasing proportion of internal micro-cracks led to an increase in the sample non-uniformity.The samples presented mainly shear failure under triaxial compression,and the failure angle decreased linearly with the increase of confining pressure.The convergence direction of cracks decreased gradually.This quantitative analysis model could accurately portray the relationship between the overall macroscopic deformation and the deviatoric stress of the samples at the compaction and the linear elastic stages,thus deepening the understanding of the stress–strain behavior of rocks.

Approaching the theoretical capacity of TiO_(2) anode in a photorechargeable lithium-ion battery

New generation of lithium-ion batteries(LIBs)integrating solar energy conversion and storage is emerging,as they could solve the fluctuation problem in the utilization of solar energy.Photo-rechargeable lithium-ion batteries(PR-LIBs)are ideal devices for such target,in which solar energy is converted into electricity and stored in LIB.In order to achieve the high performance of PR-LIB,it is crucial to develop dual-function electrode materials that can synergistically capture solar energy and store lithium.Herein,we present photo-rechargeable lithium-ion batteries using defective black TiO_(2) as photoanode prepared by lithium reduction.The photoanode exhibits excellent photo response in full solar spectrum with a capacity enhancement of 46.4%under illumination,corresponding to the energy conversion efficiency of 4.4%at the current density of 1 A·g^(-1).When illumination is applied at 20 mA·g^(-1),the battery capacity increases from~230 in dark to~349 mAh·g^(-1) at the first cycle,and then stabilizes at 310 mAh·g^(-1),approaching the theoretical value of 335 mAh·g^(-1) of TiO_(2) electrode material.This finding provides thoughts for breaking the capacity limitations in TiO_(2) and paves the way for powering LIBs by solar illumination.

Configurable microcavity-enhanced graphene photothermoelectric terahertz detectors

Terahertz(THz)detectors with high sensitivity,fast response speed,room temperature operation,and self-powered feature are the key component for many THz applications.Microcavity resonators can effectively improve the sensitivity of THz detectors.However,it is difficult to precisely evaluate the microcavity resonator induced such improvement in experiment.Here,we realize a configurable microcavity–antenna-integrated graphene photothermoelectric(PTE)THz detector.Through the microcavity–antenna hybrid structure,THz radiations are localized and enhanced at one end of the graphene channel,and the temperature difference along the channel is greatly increased,resulting in the strong enhancement of PTE response.At the resonant frequency,the device has a high responsivity(976 V/W),low noise equivalent power(2.87 pW∕Hz1∕2),and fast response speed(300 ns)at room temperature and in zero-bias operation mode.The microcavity-induced peak enhancement factor of 13.14 is accurately extracted.The microcavity–antenna introduced enhancement is further confirmed by using a two-temperature heat transfer model.The strategy of using a configurable microcavity is useful for further optimizing THz detectors by introducing the critical coupling mechanism.

Investigation of distribution uniformity of distributor for biogas slurry application based on CFD analysis

A horizontal distributor for biogas slurry application was proposed to explore the distribution performance through CFD analysis and verified by field test.The rheological properties of biogas slurry were analyzed at first,and key parameters were obtained for the next simulation.The effects of distribution modes,inlet direction,and outlets number on the velocity distribution of flow field and mass flow rate of the horizonal distributor were investigated by CFD simulations.Results of rheological properties indicated that biogas slurry was a non-Newtonian fluid and exhibited shear-thinning behavior.It can be well described by power-law model.The simulation results showed that the geometry of rotor,especially the block numbers was the main factor that determining the fluid movement and trajectory of distribution and output.The mode rotor 1 with two blocks reached the lowest variable coefficient of mass flow rate(4.49%),indicating a higher degree of uniformity.The upward inlet direction would obtain less dead zone,and the distributor with an even outlets number would possess more uniform distribution and less dead zone.The field test of the distributor with rotor 1,upward inlet direction,and 24 outlets has been carried on to verify the simulation results,the variable coefficient of mass flow was 13.06%,which was slightly higher than the simulation(9.23%),but it still within the range of requirement(<15%).The proposed model and the findings of this work are of guiding significance for the study of the utilization technology and equipment of liquid biogas residue.

Dynamics of triboelectric nanogenerators: A review

Triboelectric nanogenerators(TENGs)represent a promising next‐generation renewable energy technology.TENGs have become increasingly popular for harvesting vibration energy in the environment due to their advantages of lightweight,broad range of material choices,low cost,and no pollution.However,issues such as input force irregularity,working bandwidth,efficiency calculation,and dynamic modeling hinder the use of TENGs in industrial or practical applications.In this paper,the modeling process of the dynamical system of a TENG is reviewed from the perspective of energy flow.In addition,this paper reviews the main contributions made in recent years to achieve optimized output based on springs,magnetic forces,and pendulums,and introduces different ways to increase the bandwidth of TENGs.Finally,the main problems of TENGs in the process of harvesting vibration energy are discussed.This review may serve as a practical reference for methods to convert irregular mechanical input sources into optimized output performance toward the commercialization of TENGs.