Development of a recovery and recycle process for a pseudomonas lipase used for large-scale enzymatic synthesis

Enzymes are potential catalysts for a wide range of large-scale chemical synthesis steps, particularly when the creation of a specific chiral center is desired. The efficient recycling of the enzyme catalyst and the removal of carryover impurities were crucial factors in the improvement of a stereoselective ester hydrolysis step used in the synthesis of a selective leukotriene antagonist. In this enzymatic reaction step, the substrate and product were both largely insoluble, while the enzyme was soluble in the aqueous reaction mixture. Microfiltration and ultrafiltration of the slurry reaction mother liquor indicated near 100% enzyme protein recovery, while activity recovery was about 70% to 80%. These activity losses might be accounted for by enzyme degradation (1 to 2 mg/L . h) during the 40-hour reaction period. Dissolved impurities, principally a diacid byproduct, in the enzyme recycling stream were reduced 60% to 70% by either lowering the solution pH to 4.0 or raising the solution ionic strength to 1 M. (c) 1993 John Wiley & Sons, Inc.     

Seagrass ecosystem multifunctionality under the rise of a flagship marine megaherbivore

Large grazers (megaherbivores) have a profound impact on ecosystem functioning. However, how ecosystem multifunctionality is affected by changes in megaherbivore populations remains poorly understood. Understanding the total impact on ecosystem multifunctionality requires an integrative ecosystem approach, which is especially challenging to obtain in marine systems. We assessed the effects of experimentally simulated grazing intensity scenarios on ecosystem functions and multifunctionality in a tropical Caribbean seagrass ecosystem. As a model, we selected a key marine megaherbivore, the green turtle, whose ecological role is rapidly unfolding in numerous foraging areas where populations are recovering through conservation after centuries of decline, with an increase in recorded overgrazing episodes. To quantify the effects, we employed a novel integrated index of seagrass ecosystem multifunctionality based upon multiple, well-recognized measures of seagrass ecosystem functions that reflect ecosystem services. Experiments revealed that intermediate turtle grazing resulted in the highest rates of nutrient cycling and carbon storage, while sediment stabilization, decomposition rates, epifauna richness, and fish biomass are highest in the absence of turtle grazing. In contrast, intense grazing resulted in disproportionally large effects on ecosystem functions and a collapse of multifunctionality. These results imply that (i) the return of a megaherbivore can exert strong effects on coastal ecosystem functions and multifunctionality, (ii) conservation efforts that are skewed toward megaherbivores, but ignore their key drivers like predators or habitat, will likely result in overgrazing-induced loss of multifunctionality, and (iii) the multifunctionality index shows great potential as a quantitative tool to assess ecosystem performance. Considerable and rapid alterations in megaherbivore abundance (both through extinction and conservation) cause an imbalance in ecosystem functioning and substantially alter or even compromise ecosystem services that help to negate global change effects. An integrative ecosystem approach in environmental management is urgently required to protect and enhance ecosystem multifunctionality.     

Fire affects wood formation dynamics and ecophysiology of Pinus pinaster Aiton growing in a dry Mediterranean area

The increase in frequency and intensity of wildfires is seriously affecting forest ecosystems, especially in drought-prone areas. Trees’ recovery after fire is related to direct tree damage and is influenced by climate conditions, such as warm temperature and water shortage. In this study, we evaluate the post-fire effects on a Pinus pinaster Aiton forest growing in a hot and dry area of the Mediterranean region by comparing burned trees with severe crown reduction against unburned and not-defoliated trees. Inter-annual analyses of dendrochronology and stable isotopes in tree rings were combined with xylogenesis monitoring to investigate the effects of fire on tree growth, ecophysiological processes and wood formation. Tree-ring and isotope data showed a growth reduction and a decrease in photosynthetic activity in the burned trees, compared to control individuals, in the three years after fire. Further, the monitoring of cambial activity demonstrated a negative influence of warm and dry periods on wood formation, low xylem production, a delay in phenology and a reduction in xylem plasticity in burned trees. Our findings suggest that substantial photosynthetic limitations caused by crown defoliation and recurrent drought events could lead to severe growth decrease and reduction of trees ability to regain the pre-disturbance productivity rates.     

MORTALITY OF SEA OTTERS IN PRINCE WILLIAM SOUND FOLLOWING THE EXXON VALDEZ OIL SPILL

Abstract: This paper presents an estimate of the total number of sea otters that died as a direct consequence of the oil spill that occurred when the T/V Exxon Valdez grounded in Prince William Sound, Alaska on 24 March 1989. We compared sea otter counts conducted from small boats throughout the Sound during the summers of 1984 and 1985 to counts made after the spill during the summer of 1989. We used ratio estimators, corrected for sighting probability, to calculate otter densities and population estimates for portions of the Sound affected by the oil spill. We estimated the otter population in the portion of Prince William Sound affected by the oil was 6,546 at the time of the spill and that the post-spill population in the summer of 1989 was 3,898, yielding a loss estimate of approximately 2,650. Bootstrapping techniques were used to approximate confidence limits on the loss estimate of about 500–5,000 otters. The wide confidence limits are a result of the complex scheme required to estimate losses and limitations of the data. Despite the uncertainty of the loss estimate it is clear that a significant fraction of the otters in the spill zone survived. We observed otters persisting in relatively clean embayments throughout the oil spill zone suggesting that the highly convoluted coastline of Prince William Sound produced refuges that allowed some sea otters in the oil spill area to survive.     

Recovery of aSasa tsuboiana population after mass flowering and death

The recovery process of aSasa tsuboiana population after a mass flowering and death in 1977 was investigated by 15 years of observation in the Hira Mountains, Kinki district, western Japan. Seed production was high (6600–13 800 seeds m⁻² inSasa plots and 3900 seeds m⁻² in a forest plot) but emergent seedling density was low (14–21 seedlings m⁻²), probably because of seed predation byMicrotus montebelli occurring between seed shedding and the next spring. The seedling density had decreased further by the next year and theS. tsuboiana population recovered from only a limited number of seedlings. In spite of such a low initial density, theS. tsuboiana population was able to regenerate successfully and attained the previous full stand height in 7–16 years.Miscantbus sinensis invaded and delayed the recovery ofS. tsuboiana in one plot, butS. tsuboiana became dominant as it caught up with the height ofM. sinensis. Seedling growth patterns, such as frequent tillering, the onset of rhizome extension in the early stage of seedling growth and frequent culm production from rhizomes, played important roles in the successful regeneration ofS. tsuboiana.     

开垦对阿拉善荒漠啮齿动物群落功能多样性的影响

开垦会导致荒漠化的加剧,并对动物群落产生严重的影响。而功能多样性恰恰能体现环境或干扰胁迫导致的群落结构差异。但有关啮齿动物群落功能多样性的研究并不多见,为此,我们在2018至2020年的4月、7月和10月利用铗日法对开垦区和未开垦区的啮齿动物群落进行调查,选择并量化了与其营养、生活史、生理、形态及活动节律等相关的5个功能性状,以探讨开垦对啮齿动物群落组成的影响,以及性状组成和功能多样性变化。研究结果表明：(1)开垦区群落的丰富度指数、多样性指数和均匀度指数均低于未开垦区,开垦改变了啮齿动物群落性状组成;(2)阿拉善荒漠啮齿动物群落组成与蛰眠、繁殖周期和食性等功能性状显著相关;(3)开垦区春、秋季群落功能丰富度和功能均匀度高于未开垦区,各季节群落功能离散度显著高于未开垦区;而未开垦区夏季群落功能丰富度高于开垦区,秋季群落功能均匀度高于开垦区;(4)开垦区和未开垦区群落功能丰富度最高值均出现在夏季,二者在不同季节间差异较大;开垦区群落功能均匀度最高值出现在春季、功能离散度最高值出现在秋季,二者在季节间差异均较小;未开垦群落功能均匀度最高值出现在秋季、功能离散度最高值出现在夏季,二者在季节间差异均较大。上述结果说明,阿拉善荒漠区啮齿动物群落功能多样性变化与土地开垦和季节相关联,开垦会从啮齿动物群落的生态空间利用程度、资源利用、种间竞争及生态位等方面影响群落功能多样性。     

内蒙古高寒露天煤矿排土场植被恢复研究

探究不同恢复年限对于露天煤矿植被群落变化和植物个体生长的影响,进一步加强生态环境保护与生态修复治理措施。以内蒙古高寒露天煤矿排土场恢复4年(2018-2021年)的植物群落为研究对象,采用样方调查方法,对样地内植物群落进行调查,设置草本样方(1 m×1 m)和灌木样方(5 m×5 m),记录植物物种组成、高度及盖度等指标,计算Shannon-Wiener多样性指数、Simpon指数、Pielou均匀度指数和物种重要值。探讨不同的恢复年限植物群落变化特征和优势植物的养分吸收,为矿区人工植被恢复提供科学依据。结果表明:(1)矿区排土场植物群落物种数、生物量和群落多样性均随着恢复年限的增加而显著增加。总物种数从恢复第1年的16种增加到恢复第4年的31种,主要是由于非人工种植植物从6种增加到19种导致,特别是在恢复第2年增加显著,然后趋于平稳,这说明恢复第2年是物种增加关键的时期;(2)随着恢复年限的增加,生物量和多样性指数显著增加;矿区植被优势物种多以禾本科披碱草(Elymus dahuricus)、无芒雀麦(Bromus inermis);豆科植物苜蓿(Medicago sativa)、草木樨(Melilotus officinalis)、沙打旺(Astragalus adsurgens)、锦鸡儿(Caragana sinica);菊科植物大籽蒿(Artemisia sieversiana);十字花科油菜(Brassica napus)和胡颓子科沙棘(Hippophae rhamnoides)为主。(3)比较不同优势植物叶片、茎和根的氮(N)、磷(P)和钾(K)含量发现,草本优势种中菊科和豆科植物显著高于禾本科植物。灌木优势种中沙棘茎的N含量和P含量显著高于锦鸡儿。研究认为,在排土场植被恢复初期(4年)的物种选择上,豆科植物和菊科植物是草本植物首选的先锋物种,另外,沙棘是灌木首选的物种。     

浙江古田山亚热带常绿阔叶林叶衰老物候影响因子研究

该文选取浙江省古田山亚热带常绿阔叶林72种木本植物,探究气候因素、系统发育关系和功能性状对亚热带常绿阔叶林叶衰老物候的影响。结果表明,叶变色期在9—12月,落叶期在10—12月。每月落叶物种数与月均温、月均降水量和月均日照时数没有显著相关性,每月叶变色物种数与月均温和月均日照时数呈弱相关;落叶性对叶变色期和落叶期具有显著影响;植物间系统发育关系对叶变色期和落叶期没有显著影响。因此,生物和非生物因子都会影响常绿阔叶树种的叶衰老,这对于提高秋季物候预测模型具有重要价值。     

中老年肩痛患者疼痛及肩关节功能恢复的影响因素分析

摘要 目的：探究分析中老年肩痛患者疼痛及肩关节功能恢复的影响因素分析。方法：采用便利抽样法,随机抽取2020年9月至2022年9月期间于我院门诊就诊的2010名中老年患者作为调查对象,对患者进行筛查、复查、确诊、随访等。并对所搜集信息进行疼痛及肩关节功能恢复单因素与多因素Logistic回归分析。结果：单因素分析显示,年龄（x²=15.274, P＜0.001）、性别（x²=10.401, P=0.001）、病程（x²=16.410, P＜0.001）和是否进行功能锻炼（x²=6.293, P=0.012）为影响中老年肩痛患者肩关节功能恢复的主要因素;年龄≥70岁（OR=1.292, 95%CI 0.953-1.750）、女性（OR=1.672, 95%CI 1.348-2.074）、病程＞1个月（OR=1.470, 95%CI 1.021-2.116）和未进行功能锻炼（OR=1.844, 95%CI 1.175-2.894）为影响中老年肩痛患者肩关节功能恢复的独立危险因素。结论：年龄≥70岁、女性、病程＞1个月和未进行功能锻炼为影响中老年肩痛患者肩关节功能恢复的独立危险因素,根据上述因素尽早快速甄别高风险患者,及早给予合理有效的康复治疗措施,可显著改善肩痛患者肩关节功能的预后。     

腰背肌康复训练联合脊柱微调手法对腰椎间盘突出症患者功能康复、血液流变学和生活质量的影响

摘要 目的：探讨腰背肌康复训练联合脊柱微调手法对腰椎间盘突出症（LDH）患者功能康复、血液流变学和生活质量的影响。方法：采用随机数字表法,将我院2020年3月~2022年3月期间收治的120例LDH患者分为对照组（60例,腰背肌康复训练）和观察组（60例,腰背肌康复训练联合脊柱微调手法）。观察两组患者临床疗效、功能康复效果、血液流变学和生活质量。结果：观察组的临床总有效率高于对照组（P<0.05）。观察组干预4周后日本骨科协会腰椎功能（JOA）评分高于对照组,Oswestry功能障碍指数（ODI）、视觉模拟评分法（VAS）评分低于对照组（P<0.05）。观察组干预4周后腰部屈曲腰部活动范围（ROM）、伸展ROM、测屈ROM和屈肌肌力、伸肌肌力高于对照组（P<0.05）。观察组干预4周后全血高切黏度、全血低切黏度、红细胞聚集指数低于对照组（P<0.05）。观察组干预4周后躯体功能、精神健康、活力、躯体疼痛、社会功能、总体健康、情感职能、生理机能维度评分高于对照组（P<0.05）。结论：腰背肌康复训练联合脊柱微调手法用于LDH患者干预中,可改善血液流变学,促进功能康复,有利于患者生活质量的提高。