肾内科教学中采用SHARP反馈法的效果及对教学满意度的影响

目的探析SHARP反馈法在肾内科教学中的应用效果。方法选取2021年5月至2022年5月皖南医学院弋矶山医院肾内科实习生50名,依据随机数表法分为两组,每组各25名。对照组采用传统教学方法,观察组采用SHARP反馈法。比较两组学习成绩、教学质量评分及教学满意度。结果观察组学生学习成绩、教学质量评分包括学习和学术价值、教师的情操、组织和表达、师生关系和互动、教师知识面评分高于对照组,差异有统计学意义(P<0.05),观察组教学满意度、学习能力评分包括学生临床思维、课堂氛围、自学能力、临床实践能力、表达能力及知识关联能力高于对照组,差异有统计学意义(P<0.05)。结论肾内科教学中采用SHARP反馈法教学的效果明显,可提升实习生学习成绩,为实习生提供高质量教学,同时提升实习生对教学方法的满意度,临床教学中可大力推广及应用。

Effect of leading-edge tubercles on the flow over low-aspect-ratio wings at low Reynolds number

Two-dimensional time-resolved particle image velocimetry(TR-PIV)and stereographic particle image velocimetry(SPIV)techniques were used to investigate the effect of leading-edge tubercles on the flow over low-aspect-ratio wing models.The angle of attack is fixed at 10°,and the Reynolds number based on chord length is 5.8×10^(3).It is shown that the leading-edge tubercles can effectively mitigate flow separation in the model and also reduce the contribution of wake vortex to the fluctuating energy of flow.Counter-rotating vortex pairs(CVPs)initiated from the peak of leading-edge tubercles can promote nearby momentum exchange,enhance mixing of the flow and increase the energy contained in the boundary layer,which results in resisting the larger adverse pressure gradient.Therefore,it is concluded that CVPs play an important role in mitigating the flow separation for wings with leading-edge tubercles.

向量值多线性奇异积分算子的加权Sharp不等式

利用不等式、原子分解性质研究了向量值多线性算子,证明了某些向量值多线性奇异积分算子的一个加权Sharp不等式,并利用此不等式得到了该向量值多线性算子的加权L^(p)型不等式和L log L型不等式。

STABILITY OF THE RAREFACTION WAVE IN THE SINGULAR LIMIT OF A SHARP INTERFACE PROBLEM FOR THE COMPRESSIBLE NAVIER-STOKES/ALLEN-CAHN SYSTEM

This paper is concerned with the global well-posedness of the solution to the compressible Navier-Stokes/Allen-Cahn system and its sharp interface limit in one-dimensional space.For the perturbations with small energy but possibly large oscillations of rarefaction wave solutions near phase separation,and where the strength of the initial phase field could be arbitrarily large,we prove that the solution of the Cauchy problem exists for all time,and converges to the centered rarefaction wave solution of the corresponding standard two-phase Euler equation as the viscosity and the thickness of the interface tend to zero.The proof is mainly based on a scaling argument and a basic energy method.

Management of Penetrating Cranioencephalic Trauma Caused by Sharp Metal Objects—Therapeutic and Evolutionary Aspects: 12 Cases at the Renaissance University Hospital in N’Djamena

Introduction: Cranioencephalic trauma caused by bladed weapons is rare, and that caused by sharp objects is exceptional. The aim of our study was to describe the clinical, therapeutic and evolutionary aspects. Materials and method: This was a descriptive and analytical study over a 48-month period at CHU la Renaissance from January 1, 2018 to December 31, 2021, concerning patients admitted for penetrating cranioencephalic trauma by pointed object. Results: Twelve cases, all male, of penetrating cranioencephalic sharp-force trauma were identified. The mean age was 34 ± 7 years, with extremes of 11 and 60 years. Farmers and herders accounted for 31% and 25% of cases respectively. The average admission time was 47 hours. Brawls were the circumstances of occurrence in 81.2% of cases. Knives (33%), arrows (25%) and iron bars (16.6%) were the objects used. Altered consciousness was present in 43.8% of cases, and focal deficit in 50%. Scannographic lesions were fracture and/or embarrhment (12 cases), intra-parenchymal haematomas (6 cases) and presence of object in place (4 cases). Surgery was performed in 11 patients. Postoperative outcome was favorable in 9 patients. After 12 months, 2 patients were declared unfit. Conclusion: Penetrating head injuries caused by sharp objects are common in Chad. Urgent surgery can prevent disabling after-effects.

Numerical Study of a Three-Dimensional Laminar Flow in a Rectangular Channel with a 180-Degree Sharp Turn

This study presents a numerical analysis of three-dimensional steady laminar flow in a rectangular channel with a 180-degree sharp turn. The Navier-Stokes equations are solved by using finite difference method for Re = 900. Three-dimensional streamlines and limiting streamlines on wall surface are used to analyze the three-dimensional flow characteristics. Topological theory is applied to limiting streamlines on inner walls of the channel and two-dimensional streamlines at several cross sections. It is also shown that the flow impinges on the end wall of turn and the secondary flow is induced by the curvature in the sharp turn.

Leading-edge receptivity of boundary layer to three-dimensional free-stream turbulence

The laminar-turbulent transition has always been a hot topic of fluid mechanics. Receptivity is the initial stage and plays a crucial role in the entire transition process. The previous studies of receptivity focus on external disturbances such as sound waves and vortices in the free stream, whereas those on the leading-edge receptivity to the three-dimensional free-stream turbulence (FST), which is more general in the nature, are rarely reported. In consideration of this, this work is devoted to investigating the receptivity process of three-dimensional Tollmien-Schlichting (T-S) wave packets excited by the three-dimensional FST in a flat-plate boundary layer numerically. The relations between the leading-edge receptivity and the turbulence intensity are established, and the influence of the FST directions on the propagation directions and group velocities of the excited T-S wave packets is studied. Moreover, the leading-edge receptivity to the anisotropic FST is also studied. This parametric investigation can contribute to the prediction of laminar-turbulent transition.

Corrigendum to“Introgression of sharp eyespot resistance from Dasypyrum villosum chromosome 2VL into bread wheat”[Crop J.11(2023)1512–1520]

The authors regret to report some missing information in the authorship and associated changes of the paper.On page 1512,the author information reads:“Caiyun Liu a,Wei Guo a,Yang Wang b,Bisheng Fu a,Jaroslav Dolezel c,Ying Liu a,Wenling Zhai a,Mahmoud Said c,d,István Molnár c,d,e,Katerina Holušovác,Ruiqi Zhang b,*,Jizhong Wu a,f,g,*”.It should be changed to“Caiyun Liu a,1,Wei Guo a,1,Yang Wang b,Bisheng Fu a,Jaroslav Dolezel c,Ying Liu a,Wenling Zhai a,Mahmoud Said c,d,István Molnár c,d,e,Katerina Holušovác,Ruiqi Zhang b,*,Jizhong Wu a,f,g,*”.On page 1512 in the footnote,the following sentence should be added below the corresponding authors’information:1 These authors contributed equally to this work.The correction has been updated above.The authors would like to apologize for any inconvenience caused.

Hydrodynamic Behavior of Gap Resonance in Multiple-Box Systems with Sharp and Round Inlet Configurations

Fluid resonance within narrow gaps in multiple-box systems with sharp and round inlet configurations are investigated by using the potential flow and viscous fluid flow models in the OpenFOAM^(■)package.Evident discrepancy between two numerical models can be observed for sharp inlet configurations.In addition to the dramatical decrease of resonant amplitude in narrow gaps,some peak values at the higher resonant frequencies predicted by the potential flow model even disappear in the viscous fluid flow results.The decreased normalized resonant amplitudes with the increase of incident wave amplitude can be observed for sharp inlet configurations.However,the hydrodynamic behaviors of multiple-box system with round inlet configurations between potential flow and viscous fluid flow models are quite similar with each other.The normalized resonant amplitudes are nearly independent of incident wave amplitudes for multiple-box systems with round inlet configurations.This implies that the energy dissipation associated with fluid viscosity and flow rotation plays an important role in the gap resonance for sharp inlet configurations;while it is insignificant for round inlet configurations.

Effect of sharp vacuum-plasma boundary on the electron injection and acceleration in a few-cycle laser driven wakefield

The electron injection and acceleration driven by a few-cycle laser with a sharp vacuum-plasma boundary have been investigated through three-dimensional(3D)particle-in-cell simulations.It is found that an isotropic boundary impact injection(BII)first occurs at the vacuum-plasma boundary,and then carrier-envelope-phase(CEP)shift causes the transverse oscillation of the plasma bubble,resulting in a periodic electron self-injection(SI)in the laser polarization direction.It shows that the electron charge of the BII only accounts for a small part of the total charge,and the CEP can effectively tune the quality of the injected electron beam.The dependences of laser intensity and electron density on the total charge and the ratio of BII charge to the total charge are studied.The results are beneficial to electron acceleration and its applications,such as betatron radiation source.

Genome sequencing reveals the evolution and pathogenic mechanisms of the wheat sharp eyespot pathogen Rhizoctonia cerealis

The necrotrophic fungus Rhizoctonia cerealis is the causal agent of devastating diseases of cereal crops including wheat(Triticum aestivum).We present a high-quality genome assembly of R.cerealis Rc207,a virulent strain causing wheat sharp eyespot.The assembly(56.36 Mb)is composed of 17.87%repeat sequences and 14,433 predicted protein-encoding genes.The Rc207 genome encodes a large and diverse set of genes involved in pathogenicity,especially rich in those encoding secreted proteins,carbohydrateactive enzymes(CAZymes),peptidases,nucleases,cytochrome P450,and secondary metabolismassociated enzymes.Most secretory protein-encoding genes,including CAZymes,peroxygenases,dehydrogenases,and cytochrome P450,were up-regulated during fungal infection of wheat.We identified 831 candidate secretory effectors and validated the functions of 10 up-regulated candidate effector proteins.Of them,nine were confirmed as necrotrophic pathogen’s effectors promoting fungal infection.Abundant potential mobile or plastic genomic regions rich in repeat sequences suggest their roles in fungal adaption and virulence-associated genomic evolution.This study provides valuable resources for further comparative and functional genomics on important fungal pathogens,and provides essential tools for development of effective disease control strategies.

英国中小学课间休息时间锐减现状、原因与思考

近年来,英国中小学课间休息时间不断锐减成为社会公众讨论的焦点话题,备受国际社会关注。英国中小学课间休息时间锐减主要表现为总时长方面呈阶梯式递减趋势,分时段的中午和下午休息时长是主要被削减时段。研究发现,效率至上教育质量观的抑制、学校相关活动对课间休息时间的挤占、教师基于“合理性理由”取消课间休息以及认知层面对课间休息定位模糊是造成英国中小学课间休息时间锐减的主要原因。英国的中小学课间休息锐减并非一国现象,具有普遍的启示意义。中小学课间休息总时长多少为宜、休息方式隔段还是整段、能否基于“合理性理由”取消课间休息、如何组织课间休息等基本问题仍需深思与探讨。

痕迹性眨眼条件反射习得和巩固阶段海马中间神经元的放电活动变化

目的研究小鼠背侧海马中间神经元在联合型记忆习得和巩固2个阶段的放电活动变化及其特征。方法以痕迹性眨眼条件反射(trace eyeblink conditioning,tEBC)作为联合型记忆行为模型,将18只野生型C57BL/6小鼠(雄性,10~12周龄,体质量22~25 g)通过简单随机抽样分为配对组(n=9)和假配对组(n=9)。配对组每天接受配对给予的条件刺激(conditioned stimulus,CS)和非条件刺激(unconditioned stimulus,US),二者的配对关系为CS结束后250 ms给予US。假配对组每天接受同样数量的CS和US,但二者不存在时间上的配对关系。连续训练4 d,配对组小鼠建立tEBC,表现出条件眨眼反应(conditioned eyeblink response,CR)。在每天的训练过程中和训练后1.5 h,利用微电极阵列在体记录小鼠背侧海马神经元的放电活动。根据神经元的峰电位发放频率和峰电位谷-峰波宽鉴定出中间神经元(n=105),并分析其在训练期间和训练后慢波睡眠期间的放电活动变化。结果①在CR习得训练早期(第1、2天),CS能够诱发背侧海马中间神经元出现显著增强的发放活动(P<0.05);训练后慢波睡眠期间尖波涟漪波(sharp wave ripple,SWR)振荡发生时,配对组小鼠背侧海马中间神经元发放频率显著低于假配对组(P<0.05)。②在CR习得训练后期(第3、4天),与假配对组比较,配对组CS诱发的背侧海马中间神经元放电活动增强不明显;2组小鼠背侧海马中间神经元在训练后慢波睡眠期SWR振荡发生时的发放频率差异无统计学意义。结论背侧海马中间神经元在联合型记忆的习得和巩固阶段会展现出不同的放电变化。

超声引导下锐性开通自体动静脉内瘘闭塞病变的疗效及安全性研究

目的:探讨超声引导下锐性开通自体动静脉内瘘(AVF)闭塞病变的临床疗效。方法:选取2020年9月—2022年12月萍乡市人民医院收治的60例AVF闭塞患者,按随机数字表法分为观察组和对照组,各30例。对照组给予局部溶栓联合经皮腔内血管成形术(PTA)治疗,观察组给予超声引导下锐性开通联合PTA治疗。比较两组手术成功率和术后并发症发生率,比较两组不同时间点内瘘直径、横断面积和肱动脉血流量。结果:观察组手术成功率为93.33%,高于对照组的73.33%,差异有统计学意义(P<0.05)。术后1 d、3、6个月,观察组内瘘直径、横断面积及肱动脉血流量均高于对照组,差异均有统计学意义(P<0.05)。两组内瘘直径、横断面积及肱动脉血流量组间、时间对比,差异均有统计学意义(P<0.05),而交互对比,差异均无统计学意义(P>0.05)。两组术后并发症发生率比较,差异无统计学意义(P>0.05)。结论:超声引导下锐性开通AVF闭塞病变,手术成功率更高,能明显扩大患者内瘘直径和横断面积,提高肱动脉血流量。

圆利针复合刺法治疗单阶段腰椎椎管狭窄症的疗效分析

目的:观察圆利针合谷刺配合挑拨拉伸病变腰椎侧隐窝处的黄韧带治疗腰椎椎管狭窄症的临床疗效。方法:将60例腰椎椎管狭窄症患者按随机数字表法分为治疗组30例和对照组30例。治疗组采用圆利针松解治疗,对照组采用常规针刺治疗。观察两组治疗前后的VAS评分、Oswestry功能障碍指数(ODI)与MacNab标准评估疗效。结果:治疗前两组VAS评分及Oswestry功能障碍指数(ODI)评分比较,差异无统计学意义(P>0.05);与治疗前比较,两组VAS评分及Oswestry功能障碍指数(ODI)评分均较治疗前降低(P<0.01),且治疗组优于对照组,差异具有统计学意义(P<0.01)。两组治疗后疗效比较,治疗组总有效率80.00%(24/30),对照组总有效率43.33%(13/30),治疗组明显优于对照组,差异具有统计学意义(P<0.01)。治疗前两组JOA评分比较,差异无统计学意义(P>0.05);与治疗前比较,两组JOA评分均较治疗前增高,差异具有统计学意义(P<0.01),且治疗组优于对照组,差异具有统计学意义(P<0.01)。结论:圆利针复合刺法治疗腰椎椎管狭窄症疗效显著。

2018—2022年某三级口腔专科医院工作人员职业暴露情况调查

目的:探讨口腔专科工作人员职业暴露危险因素和职业伤害情况,为制定针对性职业防护措施提供依据。方法:回顾性分析2018年1月1日—2022年12月31日某三级口腔专科医院工作人员的职业暴露现状,探讨口腔专科医护工作人员职业暴露的风险因素。结果:5年职业暴露率分别为9.65%、6.54%、4.96%、5.38%、3.96%。151名职业暴露人员中,84.77%的职业暴露源不明;以女性[128人(84.77%)]、护士[63人(41.72%)]为主;暴露科室主要以综合门诊科/部(21.85%)和牙周黏膜科(17.22%)为主;主要发生于口腔诊疗操作(48.34%);08:00~11:59(51.66%)是1 d中发生职业暴露次数最多的时间;手部(87.42%)是最主要的暴露部位;暴露器械多为根管锉、牙科钻、洁治器头(38.41%)及注射针头(33.11%);2020年后工作人员职业防护考核得分有大幅度提升(P<0.05)。结论:口腔专科职业暴露风险较综合医院有其专科特色,建议在推广安全器具使用的基础上,进行喷溅操作多、诊疗次数多的操作之前开展病人血源性检测,同时在进行职业安全防护、标准操作规程、职业暴露处置等相关培训时要结合人群特点,培训形式应与受训者群体特征相适应。

具有尖锐吸收截面和显著增强电场的等离激元-光子混合谐振腔

研究了由二维光子晶体微腔和金纳米天线组成的等离激元-光子混合谐振腔中光学谐振腔对等离激元谐振腔的额外贡献。研究结果表明:与纯等离激元谐振腔相比,混合体系的吸收截面和电场强度均明显增强。特别地,混合谐振腔的吸收截面谱呈现出类Fano线形和尖峰,可以通过改变金纳米天线的数量或金纳米天线与光子晶体微腔之间的共振波长失谐进行调制。此外,混合谐振腔的电场增强因子比金纳米天线高出3个数量级。可为光热探测和光谱增强研究提供新的平台。

健康投资对家庭资产组合有效性的影响研究

健康作为一种典型的背景风险,对家庭的投融资决策有重要影响。基于2019年中国家庭金融调查(CHFS)数据,文章使用普通最小二乘法(OLS)和两阶段最小二乘法(2SLS)研究了健康投资对家庭资产组合有效性的影响。研究发现:健康投资能显著提升家庭资产组合有效性且结果具有较好的稳健性;健康投资会通过影响居民主客观金融素养水平和家庭收入水平从而影响家庭资产组合有效性;健康投资对城镇家庭、东部地区家庭、中高教育水平家庭的资产组合有效性的影响更大。该研究为健康投资如何影响家庭财富提供了重要的理论依据和政策含义。

基于改进SVR算法的模具棱线磨损预测方法研究

为研究汽车覆盖件模具棱线几何特征参数及成形工艺参数对棱线磨损的影响,实现对模具棱线磨损的精准预测,提出了一种基于改进SVR算法的模具棱线磨损预测模型.通过利用改进的拉丁超立方抽样(ILHS)方法获取模具棱线磨损有限元计算的实验样本,进而构建预测模型的输入参数集.通过耦合混沌理论、动态权重方法对蝗虫优化算法(GOA)进行改进,利用改进后的蝗虫优化算法(IGOA)对SVR算法关键参数进行寻优.构建了基于IGOASVR算法的模具棱线磨损预测模型,结合粒子群寻优算法(PSO)建立多目标优化模型,实现对模具棱线磨损的高精度预测以及几何特征参数和成形工艺参数优化.对比5种常规预测模型,基于IGOA-SVR算法的预测模型在采样点处的预测误差分别为8.546%、8.497%、8.473%,较GOA-SVR预测模型分别提高25.9%、26.2%、26.4%,预测精度相比于其他预测模型也有不同程度的提高.结果表明改进后的IGOA-SVR算法具有更高的精度.

车辆轨迹数据驱动的急弯路段追尾冲突风险时空演化规律

为有效揭示急弯路段上车辆间追尾冲突风险的形成与变化态势,选取典型事故多发急弯路段使用无人机航拍等方式采集交通流数据,利用Tracker软件提取车辆轨迹信息,构建急弯路段追尾冲突后侵入时间PET判别指标,结合冲突先导车LV与跟随车FV的速度、加速度变化划分追尾冲突模式,进而界定临界冲突点、冲突风险范围及PET变化率指标DPET,运用回归分析量化LV与FV的速度、加速度、速度差及加速度差对DPET的影响,阐明临界冲突点及主要追尾冲突模式的微观变化特性及时空演化规律。结果表明:车辆追尾冲突存在空间集聚性,主要集中在入弯缓和曲线上游、曲中标志断面下游及出弯缓和曲线下游;在潜在追尾冲突的九大类别中发生频率最高的四大类冲突数量占比高达83.24%;PET在冲突临界点和冲突风险范围内均下降,导致DPET均为负值,在冲突临界点PET快速下降,其下降程度显著大于冲突风险范围;FV速度、加速度及LV、FV间速度差、加速度差四个指标显著影响追尾冲突临界点的DPET变化;T10模式(LV减速、FV加速)冲突过程中的DPET均值最小,PET序列下降最为剧烈,危险性显著高于其他冲突模式。