桂西南喀斯特山地蚬木幼龄植株的天然更新

分析了桂西南喀斯特山地蚬木幼龄植株的结构特征、空间分布格局和生长动态,以及影响其种群更新的环境因子.结果表明: 该区域的幼龄蚬木种群为稳定型,种群空间分布格局呈集群型分布;幼龄植株的地径和株高生长趋势相同,且地径随株高的增长而增加,实生苗的地径和株高生长受到种群密度的抑制;群落乔木和灌木层对蚬木幼龄植株的更新有重要影响,而草本层的影响不显著;岩石裸露率对蚬木天然更新未产生显著影响,不同坡度、坡位上蚬木幼龄植株的株高和地径的差异极显著,不同坡向植株的密度、株高和地径差异极显著.蚬木的天然更新受到物种的生物学特性,种内、种间竞争,生境异质性及人为干扰等因素的综合影响.     

几个引进枣品种枣头及果实生长发育规律的研究

研究得知湘南地区引进沾化冬枣、梨枣和骏枣的枣头一次枝(下简称枣头)伸长生长节律与本地品种鸡蛋枣相似,幼树期枣头有两次明显的伸长生长过程,其间出现生长暂缓期。从枣头年生长量看,三个引进品种均比本地品种鸡蛋枣要小,但秋季生长量比重均比鸡蛋枣还要大。三个引进品种果实均较鸡蛋枣大,果实生长规律均与鸡蛋枣相似。但各个品种果实生育期均长于鸡蛋枣。冬枣果实生育期最长为100天~110天,梨枣与骏枣果实生育较短,梨枣70天~75天,骏枣约85天,而鸡蛋枣只有65天~70天。     

普罗布考联合家庭心脏康复训练对冠心病患者射血分数、血脂的影响分析

目的 探讨普罗布考联合家庭康复训练对冠心病患者射血分数及血脂水平的影响.方法 选择2018年6月 ～2020年6月我院收治的冠心病患者110例,按随机数字表法分成对照组和实验组,对照组给予瑞舒伐他汀治疗,实验组在对照组的基础上联合应用普罗布考及家庭康复训练.对两组患者治疗前及治疗后3个月的心功能指标、血脂水平进行检测比...     

平果喀斯特山地不同植物群落的土壤质量评价

了解喀斯特山地的土壤环境质量,对其植被恢复和石漠化治理有着重要意义。基于群落土壤肥力分析,采用典范对应分析(CCA)和因子分析相结合的方法,定量评价了广西平果喀斯特山地灌丛、灌木、仪花和蚬木群落的土壤质量。结果表明:土壤物理结构随植被恢复得到改善,土壤容重下降、孔隙增多、持水能力增强。土壤p H值以灌丛最高,仪花和蚬木林的土壤有机质、全氮和碱解氮含量明显高于灌丛和灌木,灌丛、灌木的土壤全磷、全钾和速效钾含量则显著高于次生乔木林;土壤速效磷和交换性钙含量差异不显著。CCA可以有效筛选土壤质量评价指标,土壤质量综合评价分值的大小顺序为:仪花林(0.41)蚬木林(0.27)灌丛(-0.20)灌木林(-0.44)。导致灌丛和灌木林土壤质量较低的原因主要与群落生产力低、土壤有机质等养分积累少有关。     

2008年至2010年泌尿系统感染中病原菌的分布及耐药性分析

目的了解泌尿系统感染的病原菌分布及药物耐药性。方法采用法国生物梅里埃公司的VITEK60分析仪对2008年至2010年宁波市妇女儿童医院疑为泌尿系统感染患者的尿液标本进行细菌培养、菌株鉴定,纸片扩散确证试验检测ESBLs。结果 2008年至2010年尿标本中共分离出病原菌1 561株,以大肠埃希菌最多见,占27.2%,其次肺炎克雷伯菌、奇异变形菌、粪肠球菌(D群),各占6.34%、6.28%和6.21%,再次是表皮葡萄球、白色念珠菌和屎肠球菌(D群),各占4.48%、4.36%和3.91%。表皮葡萄球、粪肠球菌(D群)、屎肠球菌(D群)对万古霉素均敏感,对利奈唑烷仅1株粪肠球菌(D群)耐药。3年中,无1例大肠埃希菌对亚胺培南耐药,1株肺炎克雷伯菌和1株奇异变形菌对亚胺培南耐药,其他药物均有不同程度耐药。结论大肠埃希菌是导致泌尿系统感染最常见的致病菌,产ESBLs的菌株已达46.6%。治疗由产ESBLs细菌引起的尿路感染首选亚胺培南和哌拉西林/他唑巴坦;引起尿路感染的革兰阳性菌主要为肠球菌,青霉素可作为治疗粪肠球菌引起的尿路感染,但不适合治疗屎肠球菌引起的尿路感染,耐药率已达95%以上,呋喃妥因、利奈坐烷、万古霉素可作为首选。     

Joint Report of the Third International Bovine Lymphocyte Antigen (BoLA) Workshop, Helsinki, Finland, 27 July 1986

Summary. Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus X Bos indicus , and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.     

Soils,a sink for N2O? A review

Soils are the main sources of the greenhouse gas nitrous oxide (N₂O). The N₂O emission at the soil surface is the result of production and consumption processes. So far, research has concentrated on net N₂O production. However, in the literature, there are numerous reports of net negative fluxes of N₂O, (i.e. fluxes from the atmosphere to the soil). Such fluxes are frequent and substantial and cannot simply be dismissed as experimental noise.
Net N₂O consumption has been measured under various conditions from the tropics to temperate areas, in natural and agricultural systems. Low mineral N and large moisture contents have sometimes been found to favour N₂O consumption. This fits in with denitrification as the responsible process, reducing N₂O to N₂. However, it has also been reported that nitrifiers consume N₂O in nitrifier denitrification. A contribution of various processes could explain the wide range of conditions found to allow N₂O consumption, ranging from low to high temperatures, wet to dry soils, and fertilized to unfertilized plots. Generally, conditions interfering with N₂O diffusion in the soil seem to enhance N₂O consumption. However, the factors regulating N₂O consumption are not yet well understood and merit further study.
Frequent literature reports of net N₂O consumption suggest that a soil sink could help account for the current imbalance in estimated global budgets of N₂O. Therefore, a systematic investigation into N₂O consumption is necessary. This should concentrate on the organisms, reactions, and environmental factors involved.     

林分结构对桂西南蚬木种群天然更新的影响

研究垂直结构(树冠指数、大树比例、小树比例和树高)及密度因素(基面积、乔木密度、灌木密度、灌木盖度和蚬木比例)对桂西南喀斯特山地典型蚬木种群天然更新的影响.结果表明: 群落平均更新密度为1742～3861株·hm^-2,密度相对较低.垂直结构和密度因素对蚬木幼龄植株个体数影响不显著,对地径和株高生长有一定影响.在垂直结构变量中,树冠指数与蚬木幼苗株高呈显著负相关,与幼苗地径的相关性不显著;大树比例和树高与幼苗的地径和株高均呈显著负相关,小树比例与幼苗地径和株高呈显著正相关.在密度变量中,乔木密度与幼苗地径、株高呈显著正相关;蚬木比例与幼苗地径呈显著负相关.多元回归分析显示,林分结构因子与蚬木幼龄植株个体数的拟合较差(P>0.05),蚬木幼苗的数量分布在一定程度上受到垂直结构的综合影响;林分结构因子模型对蚬木幼苗地径和株高的拟合较好(P<0.01),幼苗地径生长主要受乔木密度影响,株高生长主要受乔木密度和基面积的共同影响.     

NaHCO3胁迫下外源海藻糖对南蛇藤几种与抗逆性有关的生理生化指标变化的影响

NaHCO3胁迫下叶面喷施海藻糖(trehalose,TR)的南蛇藤叶中活性氧(O2和H2O2)产生速率、丙二醛(MDA)含量以及电解质外渗率显著下降(P<0.05),超氧化物歧化酶(SOD),过氧化氢酶(CAT)、过氧化物酶(POD),抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性以及抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量明显提高.显示外源海藻糖可在一定程度上提高NaHCO3胁迫下的南蛇藤叶细胞膜保护功能,减少叶中活性氧的积累,抑制脂质过氧化,从而提高南蛇藤抗NaHCO3胁迫的能力.