尖叶拟船叶藓营养元素生殖配置格局

为了揭示尖叶拟船叶藓营养元素生殖配置规律,本文对其12种营养元素的生殖配置格局和季节动态进行了研究。其结果如下：成熟孢子体的生物量配置为6．67％;在成熟孢子体中12种营养元素的含量顺序是：C（452mg／g）〉N（35mg／g）〉K（8439．9μg／g）〉Ca（7012．9μg／g）〉P（2129．2μg／g）〉Mg（1482．9μg／g）〉Na（432．9μg／g）〉Mn（196．3μg／g）〉Fe（177．7μg／g）〉Al（174．8μg／g）〉Zn（68．1μg／g）〉Cu（19．4μg/g）;成熟孢子体中营养元素生殖配置顺序是：K（17．7％）〉P（15．1％）〉Cu（13．3％）〉N（11．6％）〉Na（10．5％）〉Mn（7．8％）〉Zn（7．5％）〉C（6．9％）〉Mg（6．8％）〉Ca（5．4％）〉Fe（1．3％）〉Al（1．2％）。     

中国森林生态系统N平衡现状

由于N饱和生态系统的出现,森林生态系统作为环境污染储蓄库的认识受到挑战。收集了近十余年来全国各地森林N素循环的研究资料,通过对目前大气N沉降、森林生物固N、森林生态系统N的流失、淋失、挥发等各项收支参数的分析,借助农田养分收支平衡的估算思路和方法对全国森林生态系统N平衡进行了估算。结果表明,我国森林生态系统N的输入大于输出,全国森林生态系统年容纳大气N约为736万t,其中约176万t来自于大气N沉降,约599万t来自于生物固N。而进入到森林生态系统中的N约16万t固定在木材中用以维持森林蓄积的增加,其余绝大部分则保存于森林土壤,使得森林土壤全N含量大约以每年0.002%的速率增长。但不断增加的N素输入并未导致森林生态系统N饱和,全国的森林蓄积仍保持增长的趋势,森林生态系统在N的生物地球化学循环过程中起着重要的调节作用,仍是环境N的储蓄库,对于调节气候,防治污染具有重大作用。     

某高校甲型H1N1流感确诊病例流行病学分布特征分析

目的：通过了解某高校甲型H1N1流感病例的流行病学分布特征,为预防和控制流感在高校的蔓延提供依据。方法：以某高校2009年11月6日至2009年11月24日发病并确诊的74例甲型H1N1流感病例为研究对象,分析并比较病例的年龄、性别、学历层次、年级、专业、发病时间和临床症状。结果：74例甲型H1N1流感确诊病例均为学生,罹患率为1．63％,其中男性占94．6％,女性占5．4％;病例平均年龄为20．5岁±2．2岁;94．6％的病例为本科生;本科生罹患率（4．03％）显著高于研究生（0．14％）;2006级见习期本科生罹患率（11．05％）显著高于其他年级学生;疫情的流行全距为19天,发病高峰为2009年11月13日至2009年11月18日;病例以发热、咳嗽、乏力、头疼等临床症状为主。结论：该高校甲型H1N1流感确诊病例多为22岁以下的男性学生。本研究提示加强见习学生的监测和管理、设立隔离宿舍、接种疫苗等有针对性的措施能够有效控制流感疫情在高校蔓延。     

短期内^15N标记的铵盐和硝酸盐在青藏高原高寒草甸中的运移规律

运用^15N稳定性同位素示踪技术,对高寒草甸植物和土壤微生物固持沉降氮的能力及沉降氮在小嵩草（Kobresia pygaea)草甸中的运移规律进行了研究。施肥2周后,NO3^-－^15N和NH4^ －^15N的总恢复率分别为73．5％和78％。无论是NO3^-－^15N,还是NH4^ －^15N植物所固持的^15N总是比土壤有机质或者是土壤微生物固持的多。4周后,70．6％的NO3^-－^15N和57．4％的NH4^ －^15N被固持在土壤和植物中。其中,土壤微生物所固持。在施肥6周和8周后,NO3^-－^15N的总恢复率分别为58．4％和67％,而NH4^ －^15N的总恢复率分别为43．1％和49％。植物和土壤微生物所固持的NO3^-－^15N比NH4^ －^15N多。在整个实验期间,植物固持的NO3^-N较多,而且比土壤微生物固持了较多^15N。由于无机氮的含量一直很低,无机氮库所固持的^15N一般不超过1％。上述结果意味着短期内植物在高寒草甸中对沉降氮的去向起着决定作用。     

上海地区H9N2亚型禽流感病毒的遗传演化分析

为阐明上海地区 H9N2亚型禽流感病毒分离株的遗传变异、分子特征和重组模式,选取2002和2006～2014年分离自活禽市场、家禽养殖场和生猪屠宰场的14株 H9N2亚型禽流感病毒进行分析。这14株病毒分别来源于鸡、鸭、鸽、野鸡咽喉和泄殖腔样品及猪肺脏样品,用 H9亚型荧光反转录‐聚合酶链反应（RT‐PCR）试剂盒检测后,阳性样品经无特定病原体（SPF）级鸡胚尿囊腔接种并分离病毒,用血凝抑制（HI）实验进一步确定其血凝素（HA）亚型。RT‐PCR分别扩增这14株病毒全基因并进行序列测定,分析8个基因片段的遗传发生关系,发现这些分离株主要由 F／98亚系、Y280亚系、G1亚系及未知亚系重组而成。根据8个基因片段的组合情况,这14株病毒可分成5个基因型。2002、2006～2008年分离的5株H9N2亚型禽流感病毒代表了4个不同基因型,2009～2014年分离的9株H9N2亚型禽流感病毒属第5种基因型,推测可能与疫苗免疫选择压力有关。因此,在以后工作中加强H9N2亚型禽流感分子流行病学监测是非常必要的。     

029泰国人流感H5N1病毒全基因组特征

2001年，将H5N1禽流感病毒分为A～E5种基因型。2002年后，未再发现这些基因型，而出现了8种新的基因型（V、W、X1、X2、X3、Y、Z和Z^＋）。2003年末到2004年5月，H5N1流感A病毒的再现首次波及大部分东南亚国家，然而，仅越南和泰国报告了人类病例。人们一般认为2003～2004在东亚和东南亚H5N1病毒有共同的起源，且已发现它们在抗原性上应有别于1997年和2003年初的病毒，     

淹水胁迫对秋茄(Kandelia candel)幼苗叶片C、N及单宁含量的影响——一个关于碳素-营养平衡假说的实验

通过在福建厦门同安湾潮间带滩涂种植红树植物秋茄,测定不同滩面高程（黄海高程1．6,1．0,0．4m）下1年生秋茄幼苗叶片单宁、C、N、叶绿素含量及幼苗的生长指标,研究了淹水胁迫对秋茄幼苗次生代谢物质单宁的影响及作用机理。结果表明,随着滩面高程的降低,淹水胁迫增强,秋加幼茁生物量、叶片C／N及单宁含量显著降低,在滩面高程0．4m处,与1．0m和1．6m相比,幼苗生物量分别降低了18．2％和47．0％,叶片C／N比值分别降低了17．5％和20．0％,相应地,叶片单宁含量也分别降低了44．6％和70．5％。秋茄幼苗叶片单宁含量与叶片C／N比值呈显著止相关（R=0．8425）,表明秋茄幼苗叶片中C、N含量及单宁含量对淹水胁迫的响应符合碳素／营养平衡假说。     

LuxAB标记的N2106-L在小麦根圈的定植动态

目的研究小麦PGPR（植物根际促生菌）菌株的个体生态学及其在小麦根圈的定植动态。方法采用三亲本杂交法将发光酶基因luxAB转人具有固氮能力的小麦根际促生菌Azotobacter N2106菌株中,获得标记菌株N2106-L,将标记菌株接种到灭菌和非灭菌的黄褐土、红壤和黄潮土中研究其存活状况,采用根盒试验追踪标记菌株在小麦根圈的定植动态。结果标记菌株N2106-L具有发光活性和对km、str、tet三种抗生素的抗性,且具有较好的遗传稳定性。N2106-L在灭菌土壤中的数量稍高于非灭菌土壤;在3种土壤中的数量依次为：黄褐土〉黄潮土〉红壤。N2106-L在小麦根表定植密度大于根际定植密度;在小麦根际,小麦播种10d时标记菌株在0-2cm深度根际土壤定植达到最大值（2．17±0．25）×10^6CFU／g土,20d时在2-4cm深度的根际土壤中达到最高定植水平（3．92±0．47）×10^5CFU／g土;在小麦根表,标记菌株在小麦播种10d时在所有深度的根段均达到最高定植水平,0-2cm根段定植密度为（3．60±0．60）×10^6CFU／g鲜根,12cm以下根段达到（2．78±0．56）×10^4CFU／g鲜根。结论标记菌株随着根的伸长不断向根尖方向扩散,且较为稳定地在小麦根圈定植,研究结果为小麦PGPR菌株的应用提供了可靠实验数据。     

2012-2015年广东省活禽市场外环境禽流感病毒污染状况研究

研究广东省活禽市场外环境禽流感病毒污染状况并及时发现人流感发病潜在的危险因素,为人流感防治提供科学参考依据。应用传染病技术监测平台信息管理系统数据,采用描述性流行病学方法分析各种亚型病毒感染的流行病学特征,研究2012-2015年广东省活禽市场外环境禽流感病毒污染。共采集检测广东省21个地市级样本33079份,FluA 总阳性率为24．23％,H5、H7和 H9型高致病性禽流感病毒阳性率分别为3．70％、3．89％和13．53％;除2012年阳性率呈现季节性增加外,其他年份 FluA 核酸检测阳性率均在冬春季出现一个高峰。不同部位或地点采集的标本中,宰杀或摆放禽肉案板表面阳性率最高（FluA39．49％,H58．41％,H77．41％,H923．84％）,而采集的粪便标本阳性率最低（FluA14．99％,H51．73％、H72．38％、和 H97．23％）;所采集的标本所对应的相关动物种类中,鸡（64．08％）、鸭（55．84％）和鸟类（51．92％）的禽流感病毒阳性率都达到50％以上,H5、H7和 H9在各禽类中均可以检出。同时发现,在环境中检出 H7亚型多的地区分布与其相应地区 H7N9感染的病例数呈显著相关性,（r ＝0．689,P ＜0．05）;对2322份样本进行 H6亚型核酸检测,总阳性率为2．58％,并选取 H5、H6和 H9亚型标本153份进行 N 亚型检测,检测出 H5N1、H5N2、H5N6、H6N2和 H9N2等多种亚型。2012-2015年广东省21个地市活禽市场均存在 HA 亚型（H5、H7、H9和 H6）和 NA 亚型（N1、N2、N6）等多种亚型的污染,污染程度呈现季节性分布,不同样本类型和禽类其禽流感病毒分状况不同,H7亚型的污染严重程度与 H7N9的病例感染数呈正相关性。     

不同耕作措施对土壤真菌群落结构与生态特征的影响

以传统耕作（T）为对照，研究了免耕秸秆覆盖（NTS）、免耕（NT）、秸秆还田（TS）3种保护性耕作措施对黄土高原西部雨养农业区耕层土壤真菌数量、垂直分布及群落结构的影响。结果表明：不同耕作措施对土壤真菌数量有一定影响，耕层土壤真菌总数．TS〉T，NTS〉NT，T〉NT；耕作措施对真菌群落结构的影响比较明显，3种保护性耕作处理其土壤均以绿僵菌属（Metarrhizium）、腐霉属（Phythium）、曲霉属（Aspergillus）占绝对优势，B-P优势度指数三者之和都在0．6左右；而T处理占绝对优势的菌属是绿僵菌属（Metarrhizium）和镰刀菌属（Fusarium），B—P优势度指数二者之和在0．7左右；土壤真菌群落的多样性指数和均匀性指数均呈现NTS〉TS〉T〉NT。因此，在黄土高原西部雨养农业区实施NTS和TS耕作措施，既有利于土壤有益真菌数量的增加，提高养分转化率，又有利于促进该区农业的可持续发展。     

Effect of visible light on the mitochondrial inner membrane.

Exposure of mitochondria to visible light in the presence of riboflavin resulted in the initial release of respiratory control, followed by inhibition of electron transport and dissolution of structural integrity. Under these conditions, however, cytochrome c oxidase activity remained unchanged. ATPase activity was stimulated initially and remained in this activitated state even under continued illumination. In submitochondrial preparations, both electron transport and ATPase declined as a function of illumination time; cytochrome c oxidase was not sensitive to light. Enzyme inactivation also occurred to a lesser extent in the absence of riboflavin.     

Nitrogen economy in relay intercropping systems of wheat and cotton

Relay intercropping of wheat and cotton is practiced on a large scale in China. Winter wheat is thereby grown as a food crop from November to June and cotton as a cash crop from April to October. The crops overlap in time, growing as an intercrop, from April till June. High levels of nitrogen are applied. In this study, we analyzed the N-economy of the monocultures of cotton and wheat, and of four relay intercropping systems, differing in number of rows per strip of cotton or wheat. Field experiments were carried out from 2001/02 to 2003/04 in the Yellow River region in China. We quantified the nitrogen uptake and nitrogen use efficiency of wheat and cotton in relay intercropping systems to test if intercrops are more resource use efficient in comparison to monocrops. Nitrogen (N) yields of wheat per unit area in the four intercropping systems were lower than in the monocrop, which ranged from 203 to 288 kg ha⁻¹. The total N-uptake per unit biomass was similar between wheat in mono- and intercrops. On average, the N-yield of cotton per unit area was lower in intercrops than in monocrops, which ranged from 110 to 127 kg ha⁻¹, but the total N-uptake per unit biomass was higher in intercropped cotton, as dry matter production was reduced to a greater extent by intercropping than N-uptake. The N-uptake of cotton was diminished during the intercropping phase, but recovered partially during later growth stages. The physiological nitrogen use efficiency (IE) of wheat was not much affected by intercropping, but it was reduced in cotton, due to delayed flowering and less reproductive growth. Total N-efficiency of the system was assessed by comparing the relative nitrogen yield total (RNT), i.e. the sum of the ratio’s of total N-uptake by a component crop in the intercrop relative to the N-uptake in the monocrop, to the relative yield total. RNT ranged from 1.4 to 1.7, while the relative yield total (RYT) ranged from 1.3 to 1.4, indicating that intercrops used more nitrogen per unit production than monocrops. An analysis of the crop nitrogen balance showed that the nitrogen surplus of sole crops amounted to 220 kg ha⁻¹ for wheat and 140 kg ha⁻¹ for cotton, while in the intercropping systems, the annual N surplus exceeded 400 kg ha⁻¹. Conventional N-management in intercrops thus results in high N-surpluses that pose an environmental risk. The N management could be improved by means of a demand-based rate and timing of N applications.     

有机-无机态肥氮在微型农业生态系统的转移和循环研究

本文应用~(15)N示踪法研究了有机态和无机态肥料氮在微型农业生态系统中循环的机理,以及配施下各自的功能和相互影响。初步结果表明,在土壤-黑麦草-兔亚系统中,草对硫铵~(15)N利用率达59.36％;以草饲兔,所收集兔粪~(15)N回收率为11.78％,尿为17.98％。兔粪尿N与硫铵N以1:0,0.5:0.5,0.3:0.7和0.1配施种稻,结果表明,在土壤-水稻亚系统中:(1)0.5:0.5配施促进穗头和根系发育;(2)稻株吸收有机态和无机态肥料N的比例,受配施比例的影响;(3)与单施无机肥料氮比较,配施下无机肥料氮利用率未提高或甚至下降;(4)0.3:0.7配比使有机态肥料N利用率提高;(5)0.5:0.5配比,有机肥能明显地促进无机态肥料N从秆向谷运输;(6)有机肥使无机态肥N在土壤中的固化作用增加,从而使无机肥料氮向环境转移量下降。农业生态系统具有多组分和牧食-碎屑复合食物链,氮素再循环指数达0.5,生态稳定性和发育程度优于单一种植系统。     

抑制剂及其组合对尿素^15N在小麦—土壤系统中的行为和归宿的影响

应用加有脲酶抑制剂 (HQ)、硝化抑制剂 (DCD)及其组合的标记尿素进行春小麦盆栽试验 .结果表明 ,在生长季节结束时 ,小麦回收 ,土壤残留和损失的肥料N各占施入N量的 1 7.65～ 2 3.69%、43.72～ 56.32 %和 1 9.99～ 36.77% .其中 ,与单施尿素相比 ,两种抑制剂配合使用处理的肥料N总回收率高 1 6.78% ,小麦回收高 5.96% .施用氮肥对籽粒贡献最大 ,占吸收肥料N量 43.3～ 62 .0 % .     

Calcium transport and Ca2+-ATPase activity in ram spermatozoa plasma membrane vesicles

Plasma membrane vesicles, isolated from ejaculated ram sperm, were found to contain Ca²⁺-activated Mg²⁺-ATPase and Ca²⁺ transport activities. Membrane vesicles that were exposed to oxalate as a Ca²⁺-trapping agent accumulated Ca²⁺ in the presence of Mg²⁺ and ATP. The $\text{V}{}_{\mathrm{<mtext>max</mtext>}}$ for Ca²⁺ uptake was 33 nmol/mg protein per h, and the $\text{K}{}_{\mathrm{<mtext>m</mtext>}}$ values for Ca²⁺ and ATP were 2.5 μM and 45 μM, respectively. 1 μM of the Ca²⁺ ionophore A23187, added initially, completely inhibited net Ca²⁺ uptake and, if added later, caused the release of Ca²⁺ previously accumulated. A Ca²⁺-activated ATPase was present in the same membrane vesicles which had a $\text{V}{}_{\mathrm{<mtext>max</mtext>}}$ of 1.5 μmol/mg protein per h at free Ca²⁺ concentration of 10 μM. This Ca²⁺-ATPase had $\text{K}{}_{\mathrm{<mtext>m</mtext>}}$ values of 4.5 μM and 110 μM for Ca²⁺ and ATP, respectively. This kinetic parameter was similar to that observed for uptake of Ca²⁺ by the vesicles. The Ca²⁺-ATPase activity was insensitive to ouabain. Both Ca²⁺ transport and Ca²⁺-ATPase activity were inhibited by the flavonoid quercetin. Thus, ram spermatozoa plasma membranes have both a Ca²⁺ transport activity and a Ca²⁺-stimulated ATPase activity with similar substrate affinities and specificities and similar sensitivity to quercetin.     

N,N-dimethylcarbamyl derivatives of oxazepam

Three N,N-dimethylcarbamyl derivatives of oxazepam (1-(N,N-dimethylcarbamyl)oxazepam, 3-O-(N,N-dimethylcarbamyl)oxazepam, and 1,3-O-bis(N,N-dimethylcarbamyl) oxazepam) and a 3-O-acyl-1-(N,N-dimethylcarbamyl)-oxazepam were synthesized from either oxazepam or demoxepam. Enantiomeric pairs of these derivatives and of camazepam were resolved by high-performance liquid chromatography on at least two of three commercially available chiral stationary phase columns employed. Absolute configurations of resolved enantiomers were established by comparing their circular dichroism spectra to those of enantiomeric oxazepams with known absolute stereochemistry. Similar to those of oxazepam, enantiomers of 1-(N,N-dimethylcarbamyl)oxazepam undergo rapid racemization (t1/2 1.9 min at 23 degrees C and 0.9 min at 37 degrees C) in an aqueous solution at pH 7.5. The (R)-enantiomer of rac-3-O-acyl-1-(N,N-dimethylcarbamyl)oxazepam was hydrolyzed approximately 4.6-fold faster than the (S)-enantiomer by esterases in rat liver microsomes, whereas the (S)-enantiomer was hydrolyzed approximately 43-fold faster than the (R)-enantiomer by esterases in rat brain S9 fraction.     

Inmobilization-remineralization of NO3-N and total N balance during the decomposition of glucose,sucrose and cellulose in soil incubated at different moisture regimes

A laboratory incubation experiment was conducted to study the effect of organic amendment and moisture regimes on the immobilization-remineralization of NO₃-N and total N balance in soil fertilized with KNO₃. Immobilization of NO₃-N was very rapid in soil amended with glucose and sucrose followed by a remineralization of organic N and accumulation of mineral N. Cellulose caused a slow but continued immobilization and did not show net accumulation of mineral N during 8 weeks of incubation. At the end of incubation, a significant increase in total N and organic N content of the soil was observed which is perhaps attributable to the activity of free living N₂ fixers. Although N losses seemed to have occurred at 100% WHC through denitrification in soil amended with glucose and sucrose, main cause of NO₃ elimination was microbial immobilization.     

Use of 15N stable isotope to quantify nitrogen transfer between mycorrhizal plants

Aims Mycorrhizas (fungal roots) play vital roles in plant nutrient acquisition, performance and productivity in terrestrial ecosystems. Arbuscular mycorrhizas (AM) and ectomycorrhizas (EM) are mostly important since soil nutrients, including NH₄⁺, NO₃^? and phosphorus, are translocated from mycorrhizal fungi to plants. Individual species, genera and even families of plants could be interconnected by mycorrhizal mycelia to form common mycorrhizal networks (CMNs). The function of CMNs is to provide pathways for movement or transfer of nutrients from one plant to another. In the past four decades, both ¹⁵N external labeling or enrichment (usually expressed as atom%) and ¹⁵N naturally occurring abundance (δ¹⁵N, ‰) techniques have been employed to trace the direction and magnitude of N transfer between plants, with their own advantages and limitations.     

Purification and characterization of calmodulin from rat liver mitochondria

Mitochondrial calmodulin of rat liver was purified and classified. It co-migrated with bovine brain calmodulin in non-denaturing polyacrylamide gel electrophoresis, SDS-polyacrylamide gel electrophoresis and isoelectric focusing. The mitochondrial calmodulin activated Ca²⁺-dependent phosphodiesterase of bovine brain in the presence of Ca²⁺. About 80% of the mitochondrial calmodulin was proved to be of cytosol origin. It was easily detached by washing with buffer containing EGTA. The other 20% was intramitochondrial calmodulin; half of it was in the matrix space, and half in the membrane.