Comparing the adoption of protective behaviors: The framing effects of national culture and hazard onset type

On the basis of framing effect and protective action decision model, this study examines the differences in people's response to diverse hazard onset types (sudden or gradual) under different cultural frameworks (China and the United States) and the framing effects of culture and hazard onset type on people's perception and behavioral response. The data are derived from three questionnaire surveys on people's behavioral response to H7N9 and smog emergency in China and H1N1 in the United States. Results indicate that people with different cultures and diverse contexts of hazard onset type present substantial differences in risk perception, protective action perception, stakeholder perception, and behavioral expectations. Furthermore, culture and hazard onset type exert significant framing effects on people's three types of perception, reliance on official information sources, and intention to adopt protective actions. This research empirically verifies the existence of framing effect in culture and decision scenarios, thereby helping in developing different emergency communication strategies.     

关节镜清理联合抗菌药物治疗膝关节革兰阳性菌感染的疗效观察

目的:探讨关节镜清理联合抗菌药物治疗膝关节革兰阳性菌感染患者的疗效,为临床合理治疗提供参考依据。方法:选取2017年4月～2019年7月在我院治疗的经细菌学检查确诊为革兰阳性菌感染的膝关节炎症患者128例,随机分为观察组和对照组,各64例,观察组接受关节镜下膝关节清理术联合万古霉素或替考拉宁治疗,对照组接受万古霉素或替考拉宁治疗。分析患者治疗前病原菌分布情况,比较两组临床疗效、不良反应发生情况及复发率,比较两组患者的膝关节症状评分、体征评分。结果:128例革兰阳性菌感染患者中,共检出病原菌128株,金黄色葡萄球菌、表皮葡萄球菌、凝固酶阴性葡萄球菌及肠球菌分别占23.71%、25.77%、24.74%、20.62%。观察组的优良率为95.31%(61/64),高于对照组的81.25%(52/64),两组优良率比较,差异有统计学意义(P0.05)。治疗后观察组的膝关节症状评分、体征评分均低于对照组(P0.05)。观察组的复发率低于对照组(P0.05),而两组不良反应发生率比较差异无统计学意义(P0.05)。结论:采用关节镜清理联合抗菌药物治疗膝关节革兰阳性菌感染患者疗效确切,可改善患者症状积分和体征积分,降低复发率,安全可靠。     

潮汐作用下干湿交替对黄河三角洲盐沼湿地净生态系统CO2交换的影响

潮汐作用作为盐沼湿地独特的水文特征能在短时间内强烈影响盐沼湿地的碳平衡.利用涡度相关和微气象监测技术,对黄河三角洲盐沼湿地净生态系统CO₂交换(NEE)和环境因子进行监测,并同步监测潮汐变化,探究潮汐过程及潮汐作用下干湿交替对NEE的影响.结果表明: 潮汐过程促进了白天生态系统CO₂的吸收但未对夜晚CO₂的释放产生显著影响,潮汐淹水成为影响白天NEE的主要因子.干旱阶段和湿润阶段NEE的日平均动态均呈“U”型曲线,但干旱阶段NEE的变幅较小.干湿交替增强了白天生态系统CO₂的吸收,干旱阶段最大光合速率(A_max)、表观量子产量(α)和生态系统呼吸(R_eco)的均值均高于湿润阶段.此外,干湿交替减少了盐沼湿地夜晚NEE释放的同时增强了其温度敏感性.     

Jaburetox,a urease-derived peptide: Effects on enzymatic pathways of the cockroach Nauphoeta cinerea

Jaburetox is a recombinant peptide derived from one of the Canavalia ensiformis urease isoforms. This peptide induces several toxic effects on insects of different orders, including interference on muscle contractility in cockroaches, modulation of UDP-N-acetylglucosamine pyrophosphorylase (UAP) and nitric oxide synthase (NOS) activities in the central nervous system of triatomines, as well as activation of the immune system in Rhodnius prolixus. When injected, the peptide is lethal for R. prolixus and Triatoma infestans. Here, we evaluated Jaburetox toxicity to Nauphoeta cinerea cockroaches, exploring the effects on the central nervous system through the activities of UAP, NOS, acid phosphatases (ACP), and acetylcholinesterase (AChE). The results indicated that N. cinerea is not susceptible to the lethal effect of the peptide. Moreover, both in vivo and in vitro treatments with Jaburetox inhibited NOS activity, without modifying the protein levels. No alterations on ACP activity were observed. In addition, the enzyme activity of UAP only had its activity affected at 18 hr after injection. The peptide increased the AChE activity, suggesting a mechanism involved in overcoming the toxic effects. In conclusion, our findings indicate that Jaburetox affects the nitrinergic signaling as well as the AChE and UAP activities and establishes N. cinerea as a Jaburetox-resistant model for future comparative studies.     

Photobiological properties of the inhibition of etiolated Arabidopsis seedling growth by ultraviolet-B irradiation

Alteration of 'normal' levels of ultraviolet-B light (UV-B, 280–320 nm) can affect plant chemical composition as well as growth; however, little is known about how plants perceive UV-B light. We have carried out fluence response curves, and demonstrated that the growth inhibition of etiolated Arabidopsis thaliana seedlings by low fluence UV light is specific to UV-B and not UV-A (320–390 nm). The response shows reciprocity between duration and intensity, at least over a limited range, and thus depends only on photon fluence and not on photon flux. The action spectrum for this response indicates a peak of maximum effectiveness at 290 nm, and response spectra at different fluences indicate that the most effective wavelength at 30 000  µ mol m^–2 is 290 nm, whereas 300 nm light was the most effective at 100 000  µ mol m^–2. This response occurs in mutant seedlings deficient in cryptochrome, phytochrome or phototropin, suggesting that none of the known photoreceptors is the major UV-B photoreceptor. Some null mutants in DNA repair enzymes show hypersensitivity to UV-B, suggesting that even at low fluence rates, direct damage to DNA may be one component of the response to UV-B.     

颗粒溶素的研究进展

颗粒溶素具有溶细胞作用和杀菌活性,其作用对象包括肿瘤细胞、细菌、真菌和寄生虫。颗粒溶素是T淋巴细胞、单核细胞和其他炎性细胞的化学刺激物,可以激活许多细胞因子的表达,包括调节激活T细胞表达和分泌（RANTES）、单核细胞化学引诱物蛋白（MCP）1、MCP3、巨噬细胞炎性蛋白1（MP）、白介素（IL）-10、IL-1、IL-6和干扰素（IFN）-α。颗粒溶素与感染、癌症、移植、自身免疫、皮肤和生殖疾病等多种疾病相关。基于颗粒溶素的多功能性,本文针对其作用机制和与临床常见疾病关系做一综述。     

Action of acetylxylan esterase from Trichoderma reesei on acetylated methyl glycosides

Substrate specificity of purified acetylxylan esterase (AcXE) from Trichoderma reesei was investigated on partially and fully acetylated methyl glycopyranosides. Methyl 2,3,4-tri-O-acetyl-β-

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-xylopyranoside was deacetylated at positions 2 and 3, yielding methyl 4-O-acetyl-β-

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-xylopyranoside in almost 90% yield. Methyl 2,3-di-O-acetyl β-

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-xylopyranoside was deacetylated at a rate similar to the fully acetylated derivative. The other two diacetates (2,4- and 3,4-), which have a free hydroxyl group at either position 3 or 2, were deacetylated one order of magnitude more rapidly. Thus the second acetyl group is rapidly released from position 3 or 2 after the first acetyl group is removed from position 2 or 3. The results strongly imply that in degradation of partially acetylated β-1,4-linked xylans, the enzyme deacetylates monoacetylated xylopyranosyl residues more readily than di-O-acetylated residues. The T. reesei AcXE attacked acetylated methyl β-

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-glucopyranosides and β-

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-mannopyranosides in a manner similar to the xylopyranosides.     

Ex and in vivo characterization of the wavelength‐dependent 3‐photon action cross‐sections of red fluorescent proteins covering the 1700‐nm window

Multiphoton action cross‐sections are the prerequisite for excitation light selection. At the 1700‐nm window suitable for deep‐tissue imaging, wavelength‐dependent 3‐photon action cross‐sections ησ₃ for RFPs are unknown, preventing wavelength selection. Here we demonstrate: (1) ex vivo measurement of wavelength‐dependent ησ₃ for purified RFPs; (2) a multiphoton imaging guided measurement system for in vivo measurement; and (3) in vivo measurement of wavelength‐dependent ησ₃ in RFP labeled cells. These fundamental results will provide guidelines for excitation wavelength selection for 3‐photon fluorescence imaging of RFPs at the 1700‐nm window, and augment the existing database of multiphoton action cross‐sections for fluorophores.      

Stress relaxation behaviors of articular cartilages in porcine temporomandibular joint

In this study, we tested the compressive stress relaxation behaviors of the mandibular condylar and temporal cartilages in the porcine temporomandibular joint (TMJ). The aim was to determine the quantitative and qualitative similarities and differences of compressive stress relaxation behaviors between the two cartilages. Ten porcine TMJs were used; the articular surface was divided into 5 regions: anterior, central, posterior, lateral and medial. Compressive relaxation test was carried out at a strain level of 5% in each region of the two cartilages. The stress relaxation was monitored over a period of 5 min. In all the regions of the two cartilages, the time-dependent stress relaxation curves showed a marked drop in stress within the initial 10 s, which can be fitted by a standard linear viscoelastic model. The instantaneous moduli in the temporal cartilage were dominantly larger than those in the condylar cartilage, while the condylar cartilage had slightly larger relaxation moduli than the temporal cartilage except for the medial region. The both cartilages showed the regional differences in the compressive stress relaxation behavior, and in the temporal cartilage the lateral and medial regions revealed the largest values for the instantaneous and relaxation moduli. The present results demonstrate that the viscoelastic properties of compressive stress relaxation in both cartilages are region-specific, which might have an important implication for stress distribution and transmission along with the TMJ disc.     

黄芪注射液对缺血性心肌病大鼠心肌的保护作用*

目的: 探究黄芪注射液对缺血性心肌病大鼠心肌保护作用及其机制。方法: 将36只雄性鼠随机分成:对照组(12只)、缺血性心肌病组(12只)及黄芪注射液组(12只);缺血性心肌病组和黄芪注射液组的大鼠开胸结扎冠状动脉,建立缺血心肌病大鼠模型;建立心肌缺血模型后,黄芪注射液组术后注射黄芪注射液(每周一次,剂量:10 g/kg体重),共注射4次,其他两组腹腔均注射相同剂量的生理盐水;4周后给予3组大鼠麻醉后行心电图及心脏彩超后,处死大鼠取心肌标本行电镜检查,观察其心肌病理超微结构的变化,检测大鼠心肌细胞线粒体Ca²⁺浓度和心肌细胞线粒体融合蛋白mitofusin 1(Mfn1)及凋亡因子C/EBP 同源蛋白(chop)表达,以及黄芪注射液对大鼠心肌细胞ATP敏感钾通道电流的作用。结果: 与对照组比较,缺血性心肌病组中大鼠出现心律失常现象;心室扩大,EF值降低;心肌排列紊乱,线粒体空泡化严重;线粒体Ca²⁺浓度增加(P＜0.01);Mfn1表达减低(P＜0.05),chop表达增加(P＜0.01); 与缺血性心肌病组比较,黄芪注射液组中大鼠心律失常发生率明显减少,心肌细胞动作电位时程缩短,心脏彩超及心肌病理明显改善并存在大量线粒体融合,心肌线粒体Ca²⁺浓度和chop表达明显减少(P＜0.01),而Mfn1表达明显增加(P＜0.01),心肌细胞ATP敏感钾电流明显增加(P＜0.01),该作用可被ATP敏感钾通道特异性阻断剂格列本脲阻断。结论: 黄芪注射液明显减少缺血性心肌病大鼠心律失常的发生率,继而改善缺血性心肌病大鼠心脏功能、减轻心肌病理损伤,其作用机制可能通过心肌细胞ATP敏感钾通道所介导。