Melatonin Alleviates Abscisic Acid Deficiency Inhibition on Photosynthesis and Antioxidant Systems in Rice under Salt Stress

Melatonin and abscisic acid,as major plant hormones,play important roles in the physiological and biochemical activities of crops,but the interaction between the two under salt stress is not yet clear.This study investigated the endogenous levels of melatonin and abscisic acid in rice by using exogenous melatonin,abscisic acid,and their synthetic inhibitors,and examined their interactions under salt stress.The research results indicate that melatonin and abscisic acid can improve rice salt tolerance.Melatonin alleviated the salt sensitivity caused by abscisic acid deficiency,increased antioxidant enzyme activity and antioxidant content in rice treated with abscisic acid synth-esis inhibitors,and reduced total reactive oxygen species content and thiobarbituric acid reactive substance accu-mulation.Melatonin also increased the activity of key photosynthetic enzymes and the content of photosynthetic pigments,maintaining the parameters of photosynthetic gas exchange and chlorophyllfluorescence.In summary,melatonin alleviated the effects of abscisic acid deficiency on photosynthesis and antioxidant systems in rice and improved salt tolerance.This study is beneficial for expanding the understanding of melatonin regulation of crop salt tolerance.

The Effect of Fullerenol Combined with Cisplatin on the Proliferation of Cervical Cancer HeLa Cells

This study aimed to investigate the effect of fullerenol combined with cisplatin on the proliferation of cervical cancer HeLa cells in order to provide new ideas and laboratory theoretical basis for the clinical treatment of cervical cancer. Cervical cancer cell line HeLa cells in vitro were treated with different concentrations of fullerenol, different concentrations of cisplatin, and different concentrations of fullerenol combined with cisplatin, after 24 h, 48 h, 72 h, microscope changes in cell morphology;MTT assay was used to determine the effect of drugs on the proliferation of HeLa cells. Fullerenol and cisplatin alone can inhibit the proliferation of HeLa cells in a dose-dependent and time-dependent manner;compared with cisplatin alone, different concentrations of fullerenol combined with cisplatin significantly increased the apoptosis rate of HeLa cells (P < 0.05). The inhibition of fullerenol combined with cisplatin on HeLa cells in vitro is more significant, resulting in a stronger anti-cancer effect.

构建晚期肺癌患者继发周围神经病变列线图预测模型

目的:构建晚期肺癌患者继发周围神经病变列线图预测模型,并验证该模型的预测价值。方法:回顾性收集浙江大学医学院附属第一医院呼吸内科2020年5月至2021年5月收治的335例晚期肺癌患者的社会人口统计学和临床资料,通过Pearson相关性分析、单因素和多因素logistic回归分析确定晚期肺癌患者继发周围神经病变的危险因素,根据各个危险因素对继发周围神经病变的贡献程度构建列线图预测模型,并用受试者操作特征(ROC)曲线,Calibration校准曲线和临床决策曲线评估模型的区分度、校准度和临床效用。采用2021年6月至8月我科收治的64例晚期肺癌患者对构建的列线图模型进行外部验证。结果:模型组和验证组继发周围神经病变的发生率分别为34.93%和40.63%。饮酒史(OR=3.650,95%CI:1.523~8.746)、合并糖尿病(OR=3.753,95%CI:1.396~10.086)、化疗(OR=2.887,95%CI:1.046~7.970)、靶向治疗(OR=8.671,95%CI:4.107~18.306)、免疫治疗(OR=2.603,95%CI:1.337~5.065)和肝肾功能异常(OR=12.409,95%CI:4.739~32.489)是晚期肺癌患者继发周围神经病变的独立危险因素(均P<0.05)。使用基于上述独立危险因素构建的列线图预测模型预测335例晚期肺癌患者继发周围神经病变的曲线下面积为0.913(95%CI:0.882~0.944),敏感度为85.47%,特异度为81.65%,阳性和阴性预测值分别为71.43%和91.28%,Calibration校准曲线和临床决策曲线分析提示模型的校准度和临床效用较好。用列线图预测另64例晚期肺癌患者继发周围神经病变的曲线下面积为0.764(95%CI:0.638~0.869),敏感度为79.28%,特异度为85.79%,阳性和阴性预测值分别为73.25%和85.82%,模型有良好的区分度和校准度。结论:晚期肺癌患者抗癌治疗后继发周围神经病变的风险较高,饮酒史、合并糖尿病、化疗、靶向治疗、免疫治疗和肝肾功能异常是晚期肺癌患者继发周围神经病变的独立危险因素,以此构建的列线图预测模型效果良好,可作为临床个体化评估晚期肺癌患者继发周围神经病变风险的工具。

Determination of Aromatic Components of Rosa davurica Pall. by Headspace Solid Phase Microextraction Combined with GC-MS

[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.

Mechanical property and deformation mechanism of gold nanowire with non-uniform distribution of twinned boundaries:A molecular dynamics simulation study

The mechanical property and deformation mechanism of twinned gold nanowire with non-uniform distribution of twinned boundaries(TBs)are studied by the molecular dynamics(MD)method.It is found that the twin boundary spacing(TBS)has a great effect on the strength and plasticity of the nanowires with uniform distribution of TBs.And the strength enhances with the decrease of TBS,while its plasticity declines.For the nanowires with non-uniform distribution of TBs,the differences in distribution among different TBSs have little effect on the Young's modulus or strength,and the compromise in strength appears.But the differences have a remarkable effect on the plasticity of twinned gold nanowire.The twinned gold nanowire with higher local symmetry ratio has better plasticity.The initial dislocations always form in the largest TBS and the fracture always appears at or near the twin boundaries adjacent to the smallest TBS.Some simulation results are consistent with the experimental results.

Effects of Different Seedling Raising Methods on Seedling Growth of Two Kinds of Fritillaria

[Objectives] To reveal the effects of film mulching and open ground seedling raising on the differences between Fritillaria przewalskii Maxim. and Fritillaria pallidiflora Schrenkf., find the optimal seedling raising method, and provide scientific basis for standard seedling raising technique and protecting wild resources of Fritillaria. [Methods] This experiment counted the seedling emergence number and calculated the seedling emergence indicator and the yield. [Results] The results showed that under the condition of film mulching and open ground seedling raising, the changes of Fritillaria seedlings showed an "S" curve, conforming to the Logistic equation, and the rapid growth period appeared 5-13 d after seedling emergence. Compared with the open ground seedling raising, the seedlings of F. przewalskii Maxim. and F. pallidiflora Schrenkf. raised through film mulching emerged 2-4 d earlier, and the yield increased by 56.8% and 21.71%, respectively, and the individual quality was excellent. [Conclusions] The film mulching of F. przewalskii Maxim. and F. pallidiflora Schrenkf. has great significance to protect the wild resources of Fritillaria in Eryin Mountain Area. It is recommended to adopt the film mulching method for Fritillaria seedling raising, to reduce the yield decline due to lodging, and adopt sun-shading net covering after sowing.

羟基化合物的催化转化研究:酚类与醇类化合物转化为醚与酯

在当前经济快速发展的背景下,高附加值化学品的高效绿色合成备受关注,而羟基化合物的催化转化产物醚与酯是近年来受到国内外广泛关注的环保型绿色化工产品。然而,苛刻的反应条件限制了其在催化有机合成领域的发展。基于此,本文概述了酚烷基化制备醚与醇氧化酯化制备酯的研究进展,重点总结了对催化体系改性的策略以及催化机理。主要对非均相催化体系及其机理进行讨论与概述,发现酸碱位协同催化以及金属与载体间的协同催化有利于实现醚与酯的低温、绿色合成。此外,光催化被认为是一种富有潜力的绿色合成方法,本文还介绍了光催化在醇氧化酯化反应中的应用。最后,对羟基化合物催化转化的研究工作进行了总结,并对其在催化技术中面临的挑战及未来的发展进行了展望,我们认为新型催化剂的合成与改性及其催化机理的探索仍是前景广阔的研究领域。

实习护生临床归属感的潜在类别及影响因素分析

目的探索实习护生临床归属感的潜在类别及其特征差异,分析不同类别的影响因素,为制订精准干预策略提供参考。方法2023年3月22日—12月7日,便利选取浙江、江西、安徽、河南11所医院实习的836名护生作为调查对象,应用一般资料调查问卷、临床归属感量表(护生版)、杰弗逊共情量表(护生版)、感知压力量表调查,以潜在剖面分析识别实习护生临床归属感的类别及其特征,并通过无序多分类logistic回归模型分析不同类别的影响因素。结果实习护生临床归属感分为3个类别,分别为低(46.89%)、中(44.74%)、高归属型(8.37%)。相较于低归属型,男护生归入高归属型的概率更高(OR=2.504,P=0.011);父亲职业为创业人员的实习护生归到中归属型的概率更高(OR=1.923,P=0.037);共情能力越强归到中归属型、高归属型的概率越高(OR=1.054,P<0.001;OR=1.052,P<0.001);而感知压力越小归入中归属型、高归属型的概率越高(OR=0.898,P<0.001;OR=0.816,P<0.001)。结论实习护生临床归属感普遍不高且存在异质性,可分为3个类别。院校护理教育管理者可根据不同类别特征差异进行精准干预,以提高实习护生的临床归属感。

一例肺占位合并胸主动脉假性动脉瘤患者的护理

目的总结1例肺占位合并胸主动脉假性动脉瘤的护理经验。方法对肺占位伴胸部疼痛患者进行鉴别评估及判断,通过科学的预警机制、快速反应团队及多部门协作,第一时间为患者实施腔内隔绝术(EVGE),配合做好相应护理。结果先健支架置入后被立即隔绝,远端动脉血流通畅,无内瘘、截瘫、深静脉血栓等并发症,顺利出院。结论将"预则立"的护理思维渗透到临床护理工作中,善于发现临床中非常态状况,提高疑难急危重症护理水平。

Off-flavor compounds from decaying cyanobacterial blooms of Lake Taihu

The effect of cyanobacterial bloom decay on water quality and the complete degradation of cyanobacterial blooms in a short period were examined by an enclosure experiment in Gonghu Bay of Lake Taihu,China.Water quality parameters as well as taste and odor compounds during the breakdown of cyanobacterial blooms were measured.Results showed that the decay of cyanobacterial blooms caused anoxic water conditions,decreased pH,and increased nutrient loading to the lake water.The highest concentrations of dimethyl sulfide （DMS）,dimethyl trisulfide （DMTS）,and β-cyclocitral were observed in the anoxic water,at 62331.8,12413.3,and 1374.9 ng/L,respectively.2-Methylisoborneol was dominant during the live growth phase of cyanobacterial blooms,whereas DMS and DMTS were dominant during the decomposition phase.Dissolved oxygen,pH,and chlorophyll a were negatively correlated with DMS,DMTS,and β-cyclocitral,whereas total phosphorus,total nitrogen,and ammonium （NH4＋-N） were positively correlated with DMS,DMTS,β-cyclocitral,and β-ionone.The experimental results suggested that preventing the anaerobic decomposition of cyanobacterial blooms is an important strategy against the recurrence of a malodor crisis in Lake Taihu.

Microcystis aeruginosa/Pseudomonas pseudoalcaligenes interaction effects on off-flavors in algae/bacteria co-culture system under different temperatures

We conducted an experiment to study the interaction effects of Microcystis aeruginosa and Pseudomonas pseudoalcaligenes on off-flavors in an algae/bacteria co-culture system at three temperatures（24, 28 and 32℃）. Gas chromatography-mass spectrometry was applied to measure off-flavor compounds dimethyl sulfide（DMS）, dimethyl trisulfide（DMTS）,2-methylisoborneol, geosmin（GEO） and β-cyclocitral. During the lag phase of co-cultured M. aeruginosa（first 15 days）, P. pseudoalcaligenes significantly increased the production of DMS, DMTS and β-cyclocitral at all three temperatures. In the exponential phase of co-cultured M. aeruginosa（after 15 days）, M. aeruginosa became the main factor on off-flavors in the co-culture system, and β-cyclocitral turned to the highest off-flavor compound. These results also indicated that DMS, DMTS and β-cyclocitral were the main off-flavor compounds in our M. aeruginosa/P. pseudoalcaligenes co-culture system. Univariate analysis was applied to investigate the effects of M. aeruginosa and P. pseudoalcaligenes on the production of off-flavors. The results demonstrated that both M. aeruginosa and P. pseudoalcaligenes could increase the production of DMS and DMTS, while β-cyclocitral was mainly determined by M. aeruginosa. Our results also provide some insights into understanding the relationship between cyanobacteria and heterotrophic bacteria.

Multi-UAV Cooperative Trajectory Planning Based on Many-Objective Evolutionary Algorithm

The trajectory planning of multiple unmanned aerial vehicles(UAVs)is the core of efficient UAV mission execution.Existing studies have mainly transformed this problem into a single-objective optimization problem using a single metric to evaluate multi-UAV trajectory planning methods.However,multi-UAV trajectory planning evolves into a many-objective optimization problem due to the complexity of the demand and the environment.Therefore,a multi-UAV cooperative trajectory planning model based on many-objective optimization is proposed to optimize trajectory distance,trajectory time,trajectory threat,and trajectory coordination distance costs of UAVs.The NSGA-III algorithm,which overcomes the problems of traditional trajectory planning,is used to solve the model.This paper also designs a segmented crossover strategy and introduces dynamic crossover probability in the crossover operator to improve the solving efficiency of the model and accelerate the convergence speed of the algorithm.Experimental results prove the effectiveness of the multi-UAV cooperative trajectory planning algorithm,thereby addressing different actual needs.

Shell-thickness dependent optical properties of CdSe/ CdS core/shell nanocrystals coated with thiol ligands

Using CdSe/CdS core/shell nanocrystals with 1-10 monolayers of CdS shell as the model system, we studied effects of thiol ligands on optical properties of the nanocrystals. The core/shell nanocrystals with original ligands possessed near unity photoluminescence （PL） quantum yield and single-exponential PL decay dynamics. The effects of thiol ligands on optical properties were found to depend on the shell thickness, environment （with/without oxygen）, and excitation power （single- or multi-exciton）. Systematic and quantitative results reported in this work should provide necessary information for fundamental understanding and technical applications of quantum dots （QDs） coated with thiol ligands.

Solvent-controlled regioselective arylation of indoles and mechanistic explorations

The ability to manipulate the site selectivity in C–H bond functionalization reactions is an important goal in modern chemistry.Herein,we report a new reaction strategy for the regioselective arylation of indoles at C2 or C3 positions,achieved by adjusting the solvent and with P(O)^(t) Bu_(2) as an auxiliary group.