基于废物资源化的美极梅奇酵母产油研究现状及应用潜力分析

清洁可再生能源生物柴油的开发利用是对当今能源短缺环境下化石燃料替代物的有益探索。微生物油脂作为一种可能实现生物柴油廉价、高效生产的原料引起了广泛的关注,但由于封闭式培养模式操作复杂、成本高制约了其大规模应用。美极梅奇酵母Metschnikowia pulcherrmia是一种新型产油酵母,具有适应性强、底物利用范围广、可在开放体系培养等特点,很有潜力代替传统产油微生物,实现基于生物柴油的废水及固废能源化工程应用。文中对美极梅奇酵母相关研究开展了全面调研,在分析其产油研究及应用现状的基础上,总结了美极梅奇酵母在油脂生产方面所具有的独特优势和关键影响因素,突出强调了其在开放体系培养及利用有机废弃物生产微生物油脂的可行性。此外,文中还指出了美极梅奇酵母在油脂产量、产油机理等方面存在的问题与不足,为实现生物柴油高效生产提供了新的方向和思路,有利于进一步促进其工业化应用。     

辽东山区蒙古栎径向生长对林分密度和气候因子的响应

为探究林分密度和气候因子对蒙古栎径向生长的影响,利用树木年代学方法研究了不同林分密度调控(间伐)下次生蒙古栎林径向生长变化,并结合气象数据,分析了蒙古栎生长变化的驱动因子。结果表明: 次生蒙古栎林径向生长受林分密度的影响显著。低密度原始林蒙古栎径向年均增长量为3.12 mm,2个中密度次生蒙古栎林分别为1.55和1.42 mm,高密度次生蒙古栎林为0.96 mm。20%的间伐强度对促进高密度(1900 株·hm^-2以上)栎林径向生长恢复作用有限,而对于中等密度(1600 株·hm^-2)栎林效果显著。该地区蒙古栎径向生长主要对当年1月和2月的降水变化敏感。抚育间伐降低了蒙古栎径向生长对气候因子的敏感性。在未来暖干化的气候情境下,密度调控有利于减缓气候变化对蒙古栎生长的不利影响。     

微白黄链霉菌G-1发酵液抗真菌特性研究和发酵条件优化

为明确微白黄链霉菌(Streptomyces albidoflavus)G-1发酵液抗真菌特性和较优发酵条件,本研究采用平板对峙法、生长速率法、单因素试验、RDA分析和响应面CCD设计分别对其抗真菌特性、产抗菌物质关键限制因子和发酵条件较优组合进行了探究。结果表明:S.albidoflavus G-1发酵液对马铃薯早疫病菌、西瓜枯萎病菌、小麦赤霉病菌、辣椒枯萎病菌、黄瓜疫霉病菌和桃褐腐病菌具有较好抑菌效果,抑菌率均可达70%;发酵液在≤80℃、紫外照射24 h、pH 3-13和稀释100倍条件下仍可保持70%以上抑菌率;产抗菌物质关键限制因子为初始pH值、温度、麦芽糖和马铃薯;较优发酵条件为8%麦芽糖、马铃薯16.5%、初始pH 6.5、温度30℃、转速160 r/min、发酵5 d,且在该条件下可使抑菌率提高14.46%。说明菌株G-1发酵液具有良好的抑真菌稳定性,且优化后的发酵条件可使菌株G-1在较低成本和较短时间内产生大量抗菌物质,研究结果为其后期田间应用和规模化发酵奠定了理论基础。     

1株褐藻胶降解菌的筛选、鉴定及产酶条件优化

为获得可产生褐藻胶裂解酶并高效降解褐藻胶的菌株,以海藻酸钠为唯一碳源配制培养基,以透明圈法进行初筛,DNS法复筛,从海洋生物中筛选得到1株高酶活力褐藻胶降解菌株B12,经16S rDNA序列分析、生理生化试验、电镜观察,确定该菌为弧菌属(Vibrio sp.)。通过单因素试验及响应面优化试验对影响菌株生长和产酶条件的5个因素(发酵初始pH值、发酵温度、NaCl质量浓度、接种量和装液量)进行优化。得到该菌株最佳产酶条件:pH 6.52,发酵温度28.2℃,NaCl质量浓度20.1 g/L,接种量2.1%,装液量59.5 mL。在最佳发酵条件下,B12菌株酶活力可达91.68 U/mL,相比于优化前提高了38.5%。菌株开始产酶时间提前6 h, 4℃冷藏酶活力稳定性较好。     

Optimal hatching conditions of Zophobas atratus (Coleoptera: Tenebrionidae) eggs under various culture conditions

Supermealworm, Zophobas atratus (Coleoptera: Tenebrionidae) is a tropical species used for human consumption and as an ingredient in animal feed. We investigated the hatching characteristics of Z. atratus eggs under varying conditions to optimize artificial rearing conditions. Overall, the average egg weight, width, and length decreased by 42.3%, 3.7%, and 10.1%, respectively, on the 6th day post-oviposition. We varied either temperature, photoperiod, illuminance, or humidity, while the other conditions remained constant. Of the four experimental temperatures—25 °C, 27 °C, 30 °C, and 33 °C–30 °C was associated with the highest hatching rate (91.0%) during days 5–7. Although other experimental conditions did not have a significant effect on hatchability, we were able to elucidate the ideal conditions for improved hatchability. For photoperiod, hatchability was the highest (84%) at 12L/12D, followed by 81.0% at 15L/9D, and 70% at 9L/15D. Among the illuminance conditions tested—600, 1800, and 3000 lx—hatchability was the highest at 1800 lx (82.3% on days 4–6). Among the relative humidity (RH) levels tested—50%, 65%, and 80%—hatchability was the highest at 65% RH (88.5% on days 5–6). Thus, the ideal conditions for maximum hatchability were 30 °C, 12L/12D, 65% RH, and 1800 lx. Under these combined conditions, the hatching rate increased by 93.6%, and the hatching time was reduced by two days.     

The role of primary cilia in the development and disease of the retina

The normal development and function of photoreceptors is essential for eye health and visual acuity in vertebrates. Mutations in genes encoding proteins involved in photoreceptor development and function are associated with a suite of inherited retinal dystrophies, often as part of complex multi-organ syndromic conditions. In this review, we focus on the role of the photoreceptor outer segment, a highly modified and specialized primary cilium, in retinal health and disease. We discuss the many defects in the structure and function of the photoreceptor primary cilium that can cause a class of inherited conditions known as ciliopathies, often characterized by retinal dystrophy and degeneration, and highlight the recent insights into disease mechanisms.     

Structural and functional studies of Leishmania braziliensis Hsp90

The ubiquitous Hsp90 is critical for protein homeostasis in the cells, stabilizing “client” proteins in a functional state. Hsp90 activity depends on its ability to bind and hydrolyze ATP, involving various conformational changes that are regulated by co-chaperones, posttranslational modifications and small molecules. Compounds like geldanamycin (GA) and radicicol inhibit the Hsp90 ATPase activity by occupying the ATP binding site, which can lead client protein to degradation and also inhibit cell growth and differentiation in protozoan parasites. Our goal was to produce the recombinant Hsp90 of Leishmania braziliensis (LbHsp90) and construct of its N-terminal (LbHsp90N) and N-domain and middle-domain (LbHsp90NM), which lacks the C-terminal dimerization domain, in order to understand how Hsp90 works in protozoa. The recombinant proteins were produced folded as attested by spectroscopy experiments. Hydrodynamic experiments revealed that LbHsp90N and LbHsp90NM behaved as elongated monomers while LbHsp90 is an elongated dimer. All proteins prevented the in vitro citrate synthase and malate dehydrogenase aggregation, attesting that they have chaperone activity, and interacted with adenosine ligands with similar dissociation constants. The LbHsp90 has low ATPase activity (k_cat = 0.320 min^− 1) in agreement with Hsp90 orthologs, whereas the LbHsp90NM has negligible activity, suggesting the importance of the dimeric protein for this activity. The GA interacts with LbHsp90 and with its domain constructions with different affinities and also inhibits the LbHsp90 ATPase activity with an IC₅₀ of 0.7 μM. All these results shed light on the LbHsp90 activity and are the first step to understanding the Hsp90 molecular chaperone system in L. braziliensis.     

内生真菌Preussia sp.液体发酵生产抗肿瘤活性产物Spiropreussione A 的研究

螺光黑壳菌酮A(Spiropreussione A,SP-A)是编号为AS-5的光黑壳属内生真菌Preussia sp.的代谢产物。体外实验表明SP-A对人卵巢癌细胞A2780和人肝癌细胞BEL-7404的半数抑制浓度(IC50)分别为2.4和3.0μmol/L。以SP-A的含量为主要指标,结合AS-5的生物量,通过单因素实验和正交实验,优化确定了适合SP-A积累的AS-5液体发酵培养基和培养条件。研究结果表明:AS-5发酵生产SP-A的最优培养基为葡萄糖2%,麦麸3%,磷酸二氢钾0.3%,硫酸镁0.15%,pH7.0;该菌株最佳摇瓶发酵条件为250mL摇瓶装125mL培养基,接种6片直径9mm的PDA菌片,培养温度25℃,发酵周期16d。在此条件下发酵,SP-A的含量可以达到(25.02±1.02)mg/瓶,比优化前的含量[(17.08±3.24)mg/瓶]提高了46.5%。     

建立适合中国国情的高效双向转诊机制

建立适应我国国情的高效双向转诊机制,对于推进我国的医疗体制改革具有至关重要的作用。本文通过对中西方现行卫生制度的对比,结合我国有中国特色的社会主义国家的国情,对我国的卫生制度中存在的问题进行了深入剖析,探讨如何才能有效地实现高效的双向转诊。目前,我国医疗卫生事业的问题覆盖多个方面：主要表现在医疗资源,医院管理,在岗医护人员的个人职业素质,卫生部门的监管,医疗资源的大量浪费,医院分级不平衡另多数患者普遍选择三级医院就诊,而选择二级以下医院就诊的患者则较少。如何在符合我国国情的基础上改变我国的医疗卫生现状、满足人民群众不断提高的医疗服务需求是我国医疗改革亟待解决的问题。建立高效率的双向转诊制度势在必行。目前,在双向转诊中遇到的问题：1．传统理念导致的对各级医疗机构职能的理解上存在偏差,2．医疗机构自身定位不明确,3．双向转诊制度的各项相关配套政策不完善,4．双向转诊制度的社会认同度低。高效双向转诊机制建立以后,可以节省大量的医疗资源,减少了不必要的浪费,推进了医疗资源的合理配置,减少了因地区差异引起的治疗时机延误,高效的双向转诊制度会使医疗卫生资源配置进一步优化、还可以加强医疗机构之间的协作、降低医疗费用支出、促进社区卫生服务迅速发展等有重大的意义。     

Psychotic symptoms are associated with physical health problems independently of a mental disorder diagnosis: results from the WHO World Health Survey

This study explored whether physical health problems are related to psychotic symptoms independently of a mental disorder diagnosis. A total of 224,254 subjects recruited for the World Health Organization World Health Survey were subdivided into those with both a lifetime diagnosis of psychosis and at least one psychotic symptom in the 12 months prior to the evaluation, those with at least one psychotic symptom in the past 12 months but no lifetime diagnosis of psychosis, and those without psychotic symptoms in the past 12 months and without a lifetime diagnosis of psychosis. The three groups were compared for the presence of medical conditions, health problems, and access to health care. Medical conditions and health problems (angina, asthma, arthritis, tuberculosis, vision or hearing problems, mouth/teeth problems, alcohol consumption, smoking, and accidents), medication consumption, and hospital admissions (but not regular health care visits) were more frequent in individuals with psychotic symptoms but no psychosis diagnosis, compared to those with no symptoms and no diagnosis. The number of medical conditions increased with the number of psychotic symptoms. Given the sample analyzed, this trend seems to be independent from the socio‐economic development of the country or the specific health care system.