做好基础化学实验教学第一步——线上线下辅助实验预习的探索和总结

预习是实验教学的重要环节,预习的科学设计和落实执行不仅直接决定了学生学与做、教师教与导的效果,而且在学生思维能力和探究精神的培养中承载着小杠杆撬动大效益的作用。本文介绍了武汉大学基础化学实验课程组利用线上线下资源辅助低年级学生进行实验预习的探索和总结,分享了别具一格的互动式讲义和“六步走”预习教学模式,以实现在潜移默化中推动学生思辨能力和自主学习能力的稳步提升。

高校基础化学实验准备工作精细化——以武汉大学为例

基础化学实验面向全校化学、近化学等多个学科专业开设,学生人数多、涉及专业广、仪器药品种类多数量大,繁琐的实验准备工作是很多专技人员面临的不小挑战。科学、精细的实验准备工作,不仅能降低劳动强度,提高工作效率,而且能有力支撑实验教学,提高教学质量。本文结合武汉大学基础化学实验课程的实验准备工作,详细介绍了系列精细化举措,并通过若干具体实例展示精细化实施细节,方便应用推广。

Total flavonoids of Astragalus membranaceus protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity in mice by inhibiting ferroptosis through SLC7A11/GPX-4 signaling pathway

Parkinson’s disease(PD)is a common neurodegenerative disorder with no cure.Astragalus membranaceus is used in Chinese culture as a food supplement to boost immunity.The present study aimed to explore the neuroprotective effects of total flavonoids extracted from A.membranaceus(TFA)and their protective mechanisms.TFA offered neuroprotection against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)in the mouse model of Parkinsonism,by improving behavior performance in the gait analysis and pole test,and inhibiting the decline of tyrosine hydroxylase(TH)positive neurons and TH protein expression in substantia nigra of mice.TFA also prevented 1-methyl-4-phenylpyridinium(MPP+)induced neurotoxicity in SHSY5Y cells,by increasing GSH and GSH/GSSG ratio,and reducing reactive oxygen species.In addition,the neuroprotective effects of TFA were associated with its ability to restore MPTP/MPP+induced downregulation of SLC7A11 and glutathione peroxidase 4(GPX-4).In conclusion,we demonstrated that TFA exerted significant neuroprotection against MPTP/MPP+induced neurodegeneration by inhibiting ferroptosis through the regulation of SLC7A11/GPX-4 axis,suggesting the use of TFA as a possible food supplement in the prevention of PD.

Prognostic value of preoperative prognostic nutritional index and its associations with systemic inflammatory response markers in patients with stage Ⅲ colon cancer

Background: The prognostic nutritional index(PNI) has been widely applied for predicting survival outcomes of patients with various malignant tumors. Although a low PNI predicts poor prognosis in patients with colorectal cancer after tumor resection, the prognostic value remains unknown in patients with stage Ⅲ colon cancer undergoing curative tumor resection followed by adjuvant chemotherapy. This study aimed to investigate the prognostic value of PNI in patients with stage III colon cancer.Methods: Medical records of 274 consecutive patients with stage Ⅲ colon cancer undergoing curative tumor resection followed by adjuvant chemotherapy with oxaliplatin and capecitabine between December 2007 and December2013 were reviewed. The optimal PNI cutoff value was determined using receiver operating characteristic(ROC) curve analysis. The associations of PNI with systemic inflammatory response markers, including lymphocyte-to-monocyte ratio(LMR), neutrophil-to-lymphocyte ratio(NLR), platelet-to-lymphocyte ratio(PLR), and C-reactive protein(CRP)level, and clinicopathologic characteristics were assessed using the Chi square or Fisher's exact test. Correlation analysis was performed using Spearman's correlation coefficient. Disease-free survival(DFS) and overall survival(OS)stratified by PNI were analyzed using Kaplan-Meier method and log-rank test, and prognostic factors were identified by Cox regression analyses.Results: The preoperative PNI was positively correlated with LMR(r= 0.483, P < 0.001) and negatively correlated with NLR(r =-0.441, P < 0.001), PLR(r =-0.607, P < 0.001), and CRP level(r =-0.333, P < 0.001). A low PNI(≤49.22)was significantly associated with short OS and DFS in patients with stage ⅢC colon cancer but not in patients with stage ⅢA/ⅢB colon cancer.In addition, patients with a low PNI achieved a longer OS and DFS after being treated with6-8 cycles of adjuvant chemotherapy than did those with < 6 cycles. Multivariate analyses revealed that PNI was independently associated with DFS(hazard ratios 2.001; 95% confidence interval 1.157-3.462; P = 0.013).Conclusion: The present study identified preoperative PNI as a valuable predictor for survival outcomes in patients with stage Ⅲ colon cancer receiving curative tumor resection followed by adjuvant chemotherapy.

Expression of voltage.gated sodium channel Nav1.5 in non.metastatic colon cancer and its associations with estrogen receptor(ER)-βexpression and clinical outcomes

Background: Voltage-gated sodium channel 1.5(Nav1.5) potentially promotes the migratory and invasive behaviors of colon cancer cells. Hitherto, the prognostic significance of Nav1.5 expression remains undetermined. The present study aimed to explore the associations of Nav1.5 expression with clinical outcomes and estrogen receptor-β(ER-β)expression in non-metastatic colon cancer patients receiving radical resection.Methods: A total of 269 consecutive patients with pathologically confirmed stages Ⅰ-Ⅲ colon cancer who underwent radical resection were selected. Nav1.5 and ER-β expression was detected by using immunohistochemistry(IHC)on tissue microarray constructed from paraffin-embedded specimens. IHC score was determined according to the percentage and intensity of positively stained cells. Statistical analysis was performed with the X-tile method, k coefficient, Chi square test or Fisher's exact test, logistic regression, log-rank test, and Cox proportional hazards models.Results: We found that Nav1.5 was commonly expressed in tumor tissues with higher mean IHC score as compared with matched tumor-adjacent normal tissues(5.1 ± 3.5 vs. 3.5 ± 2.7, P < 0.001).The high expression of Nav1.5 in colon cancer tissues was associated with high preoperative carcinoembryonic antigen level [odds ratio(OR) = 2.980;95% confidential interval(CI)1.163-7.632; P = 0.023] and high ER-β expression(OR = 2.808; 95% CI 1.243-6.343;p = 0.00 3). Log-rank test results showed that high Nav1.5 expression contributed to a low 5-year disease-free survival(DFS) rate in colon cancer patients(77.2% vs. 92.1%, P = 0.048), especially in patients with high ER-β expression tumor(76.2% vs. 91.3%, P = 0.032). Analysis with Cox proportional hazards model demonstrated that high Nav1.5 expression[hazard ratio(HR) = 2.738; 95% CI 1.100-6.819;P = 0.030] and lymph node metastasis(HR = 2.633; 95% CI 1.632-4.248; P < 0.001) were prognostic factors for unfavorable DFS in colon cancer patients.Conclusions: High expression of Nav1.5 was associated with high expression of ER-β and indicated unfavorable oncologic prognosis in patients with non-metastatic colon cancer.

Ⅲ期结肠癌患者术前预后营养指数的预后价值及其与全身炎症反应标志物的相关性

背景与目的预后营养指数(prognostic nutritional index,PNI)已广泛应用于预测各种恶性肿瘤患者的生存结局。虽然低PNI预测肿瘤切除后的结直肠癌患者的预后不良,但对接受根治性肿瘤切除术后辅助化疗的Ⅲ期结肠癌患者的预后价值仍未知。本研究旨在探讨PNI对Ⅲ期结肠癌患者的预后价值。方法本文回顾了2007年12月至2013年12月期间,274例接受根治性肿瘤切除术后接受奥沙利铂和卡培他滨辅助化疗的Ⅲ期结肠癌的连续患者的医疗记录。采用受试者工作特征(receiver operating characteristic,ROC)曲线分析确定最佳PNI临界值。采用卡方检验或Fisher’s精确检验评估PNI与全身炎症反应标志物[包括淋巴细胞与单核细胞比值(lymphocyte-to-monocyte ratio,LMR)、中性粒细胞与淋巴细胞比值(neutrophil-to-lymphocyte ratio,NLR)、血小板与淋巴细胞比值(platelet-to-lymphocyte ratio,PLR)、C反应蛋白(C-reactive protein,CRP)水平]和临床病理特征的相关性。采用Spearman’s相关系数进行相关分析。采用Kaplan-Meier法和log-rank检验分析PNI分层的无病生存期(disease-free survival,DFS)和总生存期(overall survival,OS),并通过Cox回归分析确定预后因子。结果术前PNI与LMR呈正相关(r=0.483,P <0.001),与NLR(r=-0.441,P <0.001)、PLR(r=-0.607,P <0.001)和CRP水平(r=-0.333,P <0.001)呈负相关。在ⅢC期结肠癌患者中,低PNI(≤49.22)与短OS和DFS显著相关,而在ⅢA/ⅢB期结肠癌患者中则不相关。此外,在PNI低的患者中,接受6–8个疗程辅助化疗的患者比接受<6个疗程治疗的患者获得了更长的OS和DFS。多变量分析显示PNI与DFS独立相关(风险比=2.001;95%置信区间:1.157–3.462;P=0.013)。结论术前PNI是接受根治性肿瘤切除术后辅助化疗的Ⅲ期结肠癌患者生存结局的重要预测指标。

Numerical investigation of the mechanical behavior of the backfill–rock composite structure under triaxial compression

To ensure safe and economical backfill mining,the mechanical response of the backfill–rock interaction system needs to be understood.The numerical investigation of the mechanical behavior of backfill–rock composite structure(BRCS)under triaxial compression,which includes deformation,failure patterns,strength characteristics,and acoustic emission(AE)evolution,was proposed.The models used in the tests have one rough interface,two cement–iron tailings ratios(CTRs),four interface angles(IAs),and three confining pressures(CPs).Results showed that the deformation,strength characteristics,and failure patterns of BRCS under triaxial compression depend on IA,CP,and CTR.The stress–strain curves of BRCS under triaxial compression could be divided into five stages,namely,compaction,elasticity,yield,strain softening,and residual stress.The relevant AE counts have corresponding relationships with different stages.The triaxial compressive strengths of composites increase linearly with the increase of the CP.Furthermore,the CP stress strengthening effect occurs.When the IAs are45°and 60°,the failure areas of composites appear in the interface and backfill.When the IAs are 75°and 90°,the failure areas of composites appear in the backfill,interface,and rock.Moreover,the corresponding failure modes yield the combined shear failure.The research results provide the basis for further understanding of the stability of the BRCS.

对可切除的中/低位直肠癌是/否进行术前放化疗的全直肠系膜切除术研究:一项前瞻性、单中心、随机试验的长期分析

背景与目的我们的Ⅱ期随机试验的初步研究结果显示,对进行全直肠系膜切除术(total mesorectal excision,TME)的患者是/否进行术前同步放化疗(concurrent chemoradiotherapy,CCRT),二者的功能性括约肌保留率和短期生存结局相近。在经过中位71个月的随访后,现报告这一长期试验的结果。方法在2008年3月23日至2012年8月2日期间,192例患有T3–T4或淋巴结阳性、可切除的中/低直肠腺癌患者被随机分为接受或不接受术前CCRT组,之后均进行TME。评估以下终点:局部复发和远处转移的累积率、无病生存(disease?free survival,DFS)和总生存(overall survival,OS)。结果对入组的184例患者资料进行分析,其中TME组有94例,CCRT+TME组有90例。在整个队列中,5年DFS和OS率分别为84.8%和85.1%。CCRT+TME组的5年DFS率为85.2%,TME组为84.3%(P=0.969);CCRT+TME组的5年OS率为83.5%,TME组为86.5%(P=0.719)。在CCRT+TME和TME组中,局部复发的5年累积率分别为6.3%和5.0%(P=0.681),远处转移的5年累积率分别为15.0%和15.7%(P=0.881)。通过亚组分析,接受CCRT未观察到5年DFS和OS的显著改善。结论两种治疗方案的长期结局相近。因此,如果可以进行高质量的TME手术和强化化疗,建议选择性地对直肠癌患者进行术前CCRT。

Manipulating selenium molecular configuration in N/O dual-doped porous carbon for high performance potassium-ion storage

Potassium-selenium(K-Se)batteries have attracted more and more attention because of their high theoretical specific capacity and natural abundance of K resources.However,dissolution of polyselenides,large volume expansion during cycling and low utilization of Se remain great challenges,leading to poor rate capability and cycle life.Herein,N/O dual-doped carbon nanofibers with interconnected micro/mesopores(MMCFs)are designed as hosts to manipulate Se molecular configuration for advanced flexible K-Se batteries.The micropores play a role in confining small Se molecule(Se_(2–3)),which could inhibit the formation of polyselenides and work as physical barrier to stabilize the cycle performance.While the mesopores can confine long-chain Se(Se_(4–7)),promising sufficient Se loading and contributing to higher discharge voltage of the whole Se@MMCFs composite.The N/O co-doping and the 3D interpenetrating nanostructure improve electrical conductivity and keep the structure integrity after cycling.The obtained Se_(2–3)/Se_(4–7)@MMCFs electrode exhibits an unprecedented cycle life(395 mA h g^(−1) at 1 A g^(−1) after 2000 cycles)and high specific energy density(400 Wh kg^(−1),nearly twice the specific energy density of the Se_(2–3)@MMCFs).This study offers a rational design for the realization of a high energy density and long cycle life chalcogen cathode for energy storage.

Multi-center pragmatic studies evaluating the time indicator of cardiac perfusion reserve

Background: Since the greater part of coronary blood flow takes place during the diastolic phase of each cardiac cycle, a time indicator of myocardial perfusion reserve, the ratio of diastolic to systolic duration (D/S ratio), was presented. The objective of this study was to evaluate the accuracy and precision, the biological implication, and the applications of D/S ratio. Methods: Multi-center pragmatic studies evaluating the time indicator of cardiac perfusion reserve were performed. Related experiments, clinical trials, and surveys were conducted at 5 centers. Results: The results showed that the measurement of D/S ratio is both accurate and precise;the mean values of D/S of all of the 3 species studied (human, rabbit, and rat) were greater than 1. These application studies on D/S ratio showed that a close negative correlation existed between D/S ratio and New York Heart Association Functional Classification (NYHA FC) (r = –0.659, p pregnant women with pre-eclampsia and either normal pregnant women or non-pregnant women were significant (p Conclusions: D/S ratio has important biological implication, which is a safe, easy, reliable, and effective indicator, can be used to evaluate fitness levels, served as a pathophysiological marker for screening of cardiovascular disease (CVD), for predicting risk of cardiac events, and for evaluating the severity and prognosis of CVD.

Effectiveness of E-SBIRT intervention in community healthcare institution in China:study proposal for a randomised controlled trial

Background Many studies have demonstrated the effectiveness of Screening,Brief Intervention and Referral to Treatment(SBIRT)in addressing substance use problem.However,owing to the shortage of counsellors,it has not been widely used in China.With the development of smart medicine,we developed a web-based electronic SBIRT(E-SBIRT)program and explored the effectiveness of E-SBIRT in reducing substance use in China.Methods A randomised controlled trial will be conducted in primary healthcare institutions.Four primary healthcare institutions will be selected and randomly divided into an intervention group and a control group(each institution will recruit 60 participants,and in total,240 participants will be recruited).The control group will get a pamphlet of drug abuse prevention,and the intervention group will get the E-SBIRT intervention and the pamphlet.Both groups will receive baseline and follow-up assessment at 1 and 3 months after the intervention.The primary outcome is the change in scores on the Alcohol,Smoking and Substance Use Involvement Screening Test,and the secondary outcomes include changes in motivation,depression,anxiety,positive/negative emotion,self-esteem,addiction knowledge and addiction severity index.Conclusions If the‘E-SBIRT’program is found to be effective,it will be an accessible,affordable and widely implementable intervention to help participants at moderate risk of substance use to reduce their consumption.The potential benefit is to provide early intervention to high-risk patients in time and reduce the harmful consequences to individuals and society.

Medical image fusion based on pulse coupled neural networks and multi-feature fuzzy clustering

Medical image fusion plays an important role in clinical applications such as image-guided surgery, image-guided radiotherapy, noninvasive diagnosis, and treatment planning. In order to retain useful information and get more reliable results, a novel medical image fusion algorithm based on pulse coupled neural networks (PCNN) and multi-feature fuzzy clustering is proposed, which makes use of the multi-feature of image and combines the advantages of the local entropy and variance of local entropy based PCNN. The results of experiments indicate that the proposed image fusion method can better preserve the image details and robustness and significantly improve the image visual effect than the other fusion methods with less information distortion.

The association of handgrip strength with prevalence of hypertension among Chinese Han population

Objective To investigate the associations of handgrip strength with hypertension among Chinese Han population.Methods A total of 11, 151 subjects were recruited between October to November in 2015, using a multi-stage sampling method in 13 townships of Jurong city, Jiangsu Province, south of China.

In-plane optical anisotropy of two-dimensional VOCl single crystal with weak interlayer interaction

Transition-metal oxyhalides MOX(M=Fe,Cr,V;O=oxygen,X=F,Cl,Br,I),an emerging type of two-dimensional(2D)van der Waals materials,have been both theoretically and experimentally demonstrated to possess unique electronic and magnetic properties.However,the intrinsic in-plane anisotropic properties of 2D VOCl still lacks in-depth re-search,especially optical anisotropy.Herein,a systematic Raman spectroscopic study is performed on VOCl single-crystal with different incident laser polarization at various temperatures.The polarized-dependent Raman scattering spectra reveal that the Ag mode of VOCl show a 2-lobed shape in parallel polarization configuration while a 4-lobed shape in vertical configuration.In addition,the temperature-dependent and thickness-dependent Raman scattering spectra confirm a rela-tively weak van der Waals interaction between each layers among VOCl single crystal.These findings might provide better understanding on the in-plane anisotropic phenomenon in VOCl layers,thus will accelate further application of 2D single crystals for nanoscale angle-dependent optoelectronics.

Mechanisms of bone pain:Progress in research from bench to bedside

The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening from bone biology to neuroscience,neuroendocrinology, and immunology. In particular, the roles of primary sensory neurons and non-neuronal cells in the peripheral tissues as important targets for bone pain treatment are under extensive investigation in both pre-clinical and clinical settings. An understanding of the peripheral mechanisms underlying pain conditions associated with various bone diseases will aid in the appropriate application and development of optimal strategies for not only managing bone pain symptoms but also improving bone repairing and remodeling, which potentially cures the underlying etiology for long-term functional recovery. In this review, we focus on advances in important preclinical studies of significant bone pain conditions in the past 5 years that indicated new peripheral neuronal and non-neuronal mechanisms, novel targets for potential clinical interventions, and future directions of research.

Multi-Branch Fractional Multi-Bit Differential Detection of Continuous Phase Modulation with Decision Feedback

Differential detection of continuous phase modulation suffers from significant intersymbol interference. To reduce bit error rate, multi-branch fractional multi-bit differential detection (MFMDD) with decision feed-back is proposed. By introducing decision feedback in multi-bit differential detected signals, severe inter-symbol interference can be removed. Simulation results show that the proposed structure can greatly im-proves the performance compared with MFMDD without decision feedback, and the performance of 9 FMDD is very near to the performance of the coherent detection.

Deep Neural Network Architecture Search via Decomposition-Based Multi-Objective Stochastic Fractal Search

Deep neural networks often outperform classical machine learning algorithms in solving real-world problems.However,designing better networks usually requires domain expertise and consumes significant time and com-puting resources.Moreover,when the task changes,the original network architecture becomes outdated and requires redesigning.Thus,Neural Architecture Search(NAS)has gained attention as an effective approach to automatically generate optimal network architectures.Most NAS methods mainly focus on achieving high performance while ignoring architectural complexity.A myriad of research has revealed that network performance and structural complexity are often positively correlated.Nevertheless,complex network structures will bring enormous computing resources.To cope with this,we formulate the neural architecture search task as a multi-objective optimization problem,where an optimal architecture is learned by minimizing the classification error rate and the number of network parameters simultaneously.And then a decomposition-based multi-objective stochastic fractal search method is proposed to solve it.In view of the discrete property of the NAS problem,we discretize the stochastic fractal search step size so that the network architecture can be optimized more effectively.Additionally,two distinct update methods are employed in step size update stage to enhance the global and local search abilities adaptively.Furthermore,an information exchange mechanism between architectures is raised to accelerate the convergence process and improve the efficiency of the algorithm.Experimental studies show that the proposed algorithm has competitive performance comparable to many existing manual and automatic deep neural network generation approaches,which achieved a parameter-less and high-precision architecture with low-cost on each of the six benchmark datasets.

二维碱金属金化物双金属烯半导体

将不同金属元素通过合金化形成二维材料(金属烯)对基础研究和纳米电子器件的实际应用具有重要意义,但目前鲜有金属烯材料是具有本征带隙的半导体.受离子晶体成键特征的启发,通过结构搜索、成键分析和高通量第一性原理计算,本文从2500多个双金属烯中筛选出一系列具有晶格动力学稳定和碱金属-金离子键的二维碱金属金化物双金属烯半导体.由于碱金属和金之间的大电负性差,其中32个碱金属金化物双金属烯是带隙范围为0.97~5.20 eV的半导体材料,而锂金双金属烯由于电负性差减小呈现出金属性.Bohn-Oppenheimer分子动力学模拟表明19个双金属烯在室温下结构稳定有利于实际应用.这项研究为设计双金属烯半导体提供了指导,并揭示了二维金属合金中成键行为和电子结构性质间的关联.

Early Growth Response Gene-1 Deficiency Interrupts TGFβ1 Signaling Activation and Aggravates Neurodegeneration in Experimental Autoimmune Encephalomyelitis Mice

Early growth response protein 1(Egr-1)triggers the transcription of many genes involved in cell growth,differentiation,synaptic plasticity,and neurogenesis.However,its mechanism in neuronal survival and degeneration is still poorly understood.This study demonstrated that Egr-1 was down-regulated at mRNA and protein levels in the central nervous system(CNS)of experimental autoimmune encephalomyelitis(EAE)mice.Egr-1 knockout exacerbated EAE progression in mice,as shown by increased disease severity and incidence;it also aggravated neuronal apoptosis,which was associated with weakened activation of the BDNF/TGFβ1/MAPK/Akt signaling pathways in the CNS of EAE mice.Consistently,Egr-1 siRNA promoted apoptosis but mitigated the activation of BDNF/TGFβ1/MAPK/Akt signaling in SH-SY5Y cells.Our results revealed that Egr-1 is a crucial regulator of neuronal survival in EAE by regulating TGFβ1-mediated signaling activation,implicating the important role of Egr-1 in the pathogenesis of multiple sclerosis as a potential novel therapy target.

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction of emerging contaminants

Effective removal of emerging contaminants(ECs)to minimize their impacts on human health and the natural environment is a global priority.For the removal of ECs in water,we fabricated a seaweed spherical microsphere catalyst with Cu cation-πstructures by in situ doping of Cu species and ascorbic acid in mesoporous silica(Cu-C-MSNs)via a hydrothermal method.The results indicate that bisphenol A(BPA)is substantially degraded within 5 min under natural conditions,with its biological toxicity considerably weakened.Moreover,industrial wastewater could also be effectively purified by Cu-C-MSNs/H_(2)O_(2) system.The presence of metal sites and the complexation of ECs via cation-πinteraction andπ-πstacking on the catalyst surface were directly responsible for the polarization distribution of electrons,thus activating H_(2)O_(2) and dissolved oxygen(DO).The removal of contaminants could be attributed primarily to 1)the activation of H_(2)O_(2) into ^(·)OH to attack the contaminants and 2)self-cleavage because of the transfer of electrons from the contaminants to the catalysts.This study provides an innovative solution for the effective treatment of ECs and has positive implications for easing global environmental crises.