Carbonic anhydrase interaction with DDT, DDE, and dieldrin

The active site of various carbonic anhydrases is not blocked by DDT. DDE, or dieldrin. Impairment of catalytic efficiency can only be documented in opalescent test solutions in which the insecticides are present in excess of their solubility limit. These slowly forming precipitates occlude enzyme from solution and furnish a physical explanation of the supposed inhibition. The amounts occluded depend, among other things, on the conformational and topographical characteristics of the particular carbonic anhydrase molecules.     

大豆卵磷脂脂质体的制备

以大豆卵磷脂为材料,用反相蒸发法制备脂质体,对其形态、粒径、包封率、泄漏率和稳定性进行了研究,并与大豆磷脂脂质体的性质进行了比较。透射电镜下观察两种脂质体均为粒径均匀的球状或近似球状的小囊泡。以大豆卵磷脂制得的脂质体(SPCL)粒径是201 nm,包封率是34.2%,而以大豆磷脂制得的脂质体(SPL)的粒径是130 nm,包封率是33.8%。两种脂质体的泄漏率在最初的1 h内没有差别,但是随着时间的增加,SPL的泄漏率大于SPCL,并且其稳定性要差于SPCL。     

Capturing sound, light, and strength with new materials

Physicists, chemists, and other scientists gathered in Boston from 28 November to 2 December for the fall meeting of the Materials Research Society (MRS) to explore everything from the behavior of single atoms to bulk structures. Among the more than 4000 papers and posters presented, attendees learned about novel devices that convert light directly to sound, new techniques for studying minuscule structures called quantum dots, and organic-inorganic hybrid materials.     

Living with the past: evolution, development, and patterns of disease

Epidemiological observations have led to the hypothesis that the risk of developing some chronic noncommunicable diseases in adulthood is influenced not only by genetic and adult life-style factors but also by environmental factors acting in early life. Research in evolutionary biology, developmental biology, and animal and human physiology provides support for this idea and suggests that environmental processes influencing the propensity to disease in adulthood operate during the periconceptual, fetal, and infant phases of life. This "developmental origins of health and disease" concept may have important biological, medical, and socioeconomic implications.     

GOT、GPT、LDH、钙、磷与鸡产蛋性能的关系

我们测定了伊沙 B300父系和母系母鸡血清中 GOT、GPT、LDH 的活性和钙瞬含量,并探讨了300日龄蛋鸡生产性能的有关指标,旨在为育种工作提供科学依据。试验结果,GOT、GPT、LDH 活性和钙瞬含量与蛋鸡生产性能相关程度不同。其中 GPT 对蛋鸡生产性能相关极显著(P<0.01),GOT 和 LDH 与蛋鸡生产性能相关不显著(P>0.05)。为此我们进一步进行了 GPT 活力与主要产蛋性能的比较试验。     

遮光对3种地被植物生长和生理生化的影响

对花叶玉簪甜心Hosta × hybrida ‘So Sweet’,花叶蜘蛛抱蛋Aspidistra elatior‘Punctata’和白穗花Speirantha gardenii等3种地被植物进行不同程度遮光处理,研究了遮光条件下3种植物形态指标、叶片叶绿素质量分数、丙二醛（MDA）质量摩尔浓度和保护酶活性的变化。结果表明：在遮光处理下,3种植物形态指标都显著高于对照（全光照）,花叶玉簪甜心在遮光75%下达到最大值,花叶蜘蛛抱蛋和白穗花在遮光90%下达到最大值。3种植物叶片叶绿素a、叶绿素b质量分数均较对照显著升高,以白穗花的增幅最大。叶绿素a/b比值显著下降,以白穗花的降幅最大。3种植物丙二醛质量摩尔浓度变化呈先下降后上升的趋势,但均显著低于对照;3种植物的超氧化物歧化酶（SOD）活性均显著低于对照,花叶玉簪甜心叶片的SOD活性先下降后上升,花叶蜘蛛抱蛋和白穗花叶片的SOD活性呈缓慢下降的趋势;花叶玉簪甜心和花叶蜘蛛抱蛋过氧化物酶（POD）活性变化均为先下降后上升,白穗花叶片的POD活性在遮光50%时下降,而到遮光75%时又明显上升,后又下降。通过隶属函数法综合分析可知,3种地被植物的耐荫性由强到弱为：白穗花＞花叶蜘蛛抱蛋＞花叶玉簪甜心。图3表3参22     

甘蔗白条病(Xanthomonas albilineans)PCR,ELISA,DIA检验技术研究(英文)

应用聚合酶链式反应（ＰＣＲ）技术检测甘蔗白条病（Ｘ．ａｌｂｉｌｉｎｅａｎｓ）蔗茎无症带菌样品和纯培养及总ＤＮＡ;并以改良半选择性培养基（ｍＸＡＭ）定量．比较了ＰＣＲ,ＥＬＩＳＡ,ＤＩＡ的检测效率和可靠性．表明ＰＣＲ能够特异性检出白条黄单胞包括标准菌株３３９１５ＡＴＣＣ和血清型Ｉ,Ｉ等１９个菌株．但是不能扩增其它５个分离自蔗茎的腐生黄单胞和１３个其它属种的植物细菌．能够检出少至１０ｐｇ靶细菌总ＤＮＡ或２０个活细菌．ＰＣＲ检测灵敏度较ＥＬＩＳＡ和ＤＩＡ高１００～１０００倍．田间样品检测结果与实际发病符合度为９３．４６％．这一分子检测技术适用于国内外甘蔗种质资源交换和口岸检疫以及病害流行学研究     

Toxicant-disease-environment interactions associated with suppression of immune system, growth, and reproduction

The effects of marginal malnourishment , infections, and environmental chemicals on growth and reproductive success in Swiss-Webster white mice and wild deer mice were studied with fractional factorial designs. Interaction effects were discovered. For example, malnourished mice were more sensitive to virus exposure and environmental chemicals (a plant growth regulator or polychlorinated biphenyls). Since several commercial plant growth regulators also appear to suppress the immune system, these results cast doubt on the adequacy of current toxicity testing procedures in which factors are studied individually and not in combination.     

Isolation of a new virus, HBLV, in patients with lymphoproliferative disorders

A novel human B-lymphotropic virus (HBLV) was isolated from the peripheral blood leukocytes of six individuals: two HTLV-III seropositive patients from the United States (one with AIDS-related lymphoma and one with dermatopathic lymphadenopathy), three HTLV-III seronegative patients from the United States (one with angioimmunoblastic lymphadenopathy, one with cutaneous T-cell lymphoma, and one with immunoblastic lymphoma), and one HTLV-III seronegative patient with acute lymphocytic leukemia from Jamaica. All six isolates were closely related by antigenic analysis, and sera from all six virus-positive patients reacted immunologically with each virus isolate. In contrast, only four sera from 220 randomly selected healthy donors and none from 12 AIDS patients without associated lymphoma were seropositive. The virus selectively infected freshly isolated human B cells and converted them into large, refractile mono- or binucleated cells with nuclear and cytoplasmic inclusion bodies. HBLV is morphologically similar to viruses of the herpesvirus family but is readily distinguishable from the known human and nonhuman primate herpesviruses by host range, in vitro biological effects, and antigenic features.     

超声搅拌悬浮液进样FAAS法测定茶叶中的铜、铁、锌、铅、镉含量

将超声搅拌悬浮液进样技术应用于火焰原子吸收光谱法,成功地测定了茶叶中铜、铁、锌、铅、镉的含量,此法快速、简单、准确.样品在(80±2)℃烘干4 h后,研磨过160目筛,然后加入5 mL 0.15%琼脂悬浮液,用超声搅拌混匀后直接上机测定.测定结果与传统湿法一致,t检验表明两者无显著性差异,相对误差＜±0.96%.     

王水水浴消解法测定土壤中Cu,Zn,Pb,Ni的方法

分别用王水水浴消解、电热板-坩埚消解和微波消解3种方法进行土壤标准样品的前处理,然后用火焰原子吸收光谱法测定土壤中Cu,Zn,Ni,Pb的含量,并进行加标回收试验。结果表明,王水水浴消解法能准确地检测出土壤标准样品中Cu,Zn,Ni,Pb的含量,回收率为90.4%~104.8%,在预处理方面优于其他2种方法,具有用酸量少、消解温度低、时间短、操作简便等优点。     

Cooling, heating, generating power, and recovering waste heat with thermoelectric systems

Thermoelectric materials are solid-state energy converters whose combination of thermal, electrical, and semiconducting properties allows them to be used to convert waste heat into electricity or electrical power directly into cooling and heating. These materials can be competitive with fluid-based systems, such as two-phase air-conditioning compressors or heat pumps, or used in smaller-scale applications such as in automobile seats, night-vision systems, and electrical-enclosure cooling. More widespread use of thermoelectrics requires not only improving the intrinsic energy-conversion efficiency of the materials but also implementing recent advancements in system architecture. These principles are illustrated with several proven and potential applications of thermoelectrics.     

高产优质杂交玉米黔单10号的选育

黔单10号是贵州省农业科学院旱粮所用自交系93－63作母本、Q102作父本组配选育的高产、优质、多抗紧凑型玉米杂交种，2000年已通过贵州省品种审定委员会和全国品种审定委员会审定。该品种具有较好的丰产性和适应性，其产量一般在7500kg/hm^2左右；能抗大小斑病、丝黑穗病等多种病害；其粗蛋白含量为11．27％，赖氨酸含量为0．37％，营养品质优。已列为2001年农业部丰收计划推荐推广品种，具有较大的推广和利用潜力。同时黔单10号制种难度小，制种产量高，推广和经营均可产生较好的经济效益和社会效益。     

Homing behavior, orientation, and home range of salamanders tagged with tantalum-182

Using radioactive tags, we recorded movements of salamanders (Plethodon jordani) in their home areas and during homing. Males occupied home areas about three times larger than those of females and made occasional excursions into outlying regions. Homing after 22-to 60-meter displacements was direct and rapid, once initiated. Course headings at 1 meter from release were random; those at 2 meters and more were home-oriented. Males initiated homing movements sooner than females, although both sexes traveled at similar rates. Increased incidence of climbing on vegetation after displacement suggests olfactory mechanisms of orientation. These observations give direct evidence of homing orientation in caudate amphibians.     

Detection, stimulation, and inhibition of neuronal signals with high-density nanowire transistor arrays

We report electrical properties of hybrid structures consisting of arrays of nanowire field-effect transistors integrated with the individual axons and dendrites of live mammalian neurons, where each nanoscale junction can be used for spatially resolved, highly sensitive detection, stimulation, and/or inhibition of neuronal signal propagation. Arrays of nanowire-neuron junctions enable simultaneous measurement of the rate, amplitude, and shape of signals propagating along individual axons and dendrites. The configuration of nanowire-axon junctions in arrays, as both inputs and outputs, makes possible controlled studies of partial to complete inhibition of signal propagation by both local electrical and chemical stimuli. In addition, nanowire-axon junction arrays were integrated and tested at a level of at least 50 "artificial synapses" per neuron.     

菜用大豆施肥后荧光、光谱、光合等参数对产量的预测

以春风极早、M-3、M-4、绿宝石4个菜用大豆为试材,测定了大豆开花期、结荚期、鼓粒期的叶绿素荧光、光谱、光合等参数,并分别与产量进行逐步回归分析,建立开花期、结荚期、鼓粒期回归方程。结果表明,以结荚期各项数据构建的回归方程拟合程度最好,开花期各项数据构建的回归方程拟合程度最差。该模型可作为预测667 m²产量的最优回归模型Y=2 188.289+5 044.333X₂+6.804X₄-8 916.411X₈+14 236.585X₁₀-0.043X₁₂+2 283.778X₁₅。因此,在实际生产过程中,测定结荚期叶片的叶绿素荧光参数、光谱参数、光合参数,代入该拟合方程,可以对菜用大豆的产量进行预测。     

高产多抗中强筋小麦陕512的选育研究（Ⅰ）

陕512小麦是西北农林科技大学农学院以陕麦150太谷核不育系为母本,以陕354为父本,1997年田间杂交,轮回选择结合系谱法育成,2001年出圃,2004年9月提前通过审定。因长势好、产量高,籽粒大、外观商品性好、中强筋、适口性优,抗病、抗干热风、抗穗发芽,被多家种子公司列为统供品种,迅速推广开来。该品种选育推广之快说明轮回选择是提高产量因子之间及产量、品质、抗性之间在更高水平上和谐的有效途径。     

采用ICP-AES测定镉、铅、铜与锌过程中相互干扰关系研究

配制不同浓度镉、铅、铜与锌的混合溶液,而后应用电感耦合等离子体原子发射光谱法(ICP-AES)对这4种元素进行测定,以研究应用ICP-AES测定镉、铅、铜与锌时,镉、铅、铜与锌之间的干扰关系.结果表明:镉、铅、铜与锌在一定的浓度范围内均存在一定的干扰.当被测元素镉、铅、铜的浓度为0.01 mg/L时,干扰元素锌对这3种元素的干扰均较大;当被测元素铅的浓度为1 mg/L时,锌对铅的干扰较大,对镉、铜这一浓度的干扰较小;当被测元素镉、铅、铜的浓度为10和100mg/L时,锌对这3种元素干扰较小.当锌的浓度为0.01,1mg/L时,镉、铅、铜3种元素对锌的干扰最大,影响顺序为:镉＞铅＞铜;当被测元素锌浓度为10和100mg/L时,镉、铅、铜对锌测定影响较小.     

高职园林“教、练、创”一体化实践教学体系构建研究

实践教学是培养高职学生实践技术应用能力和综合素质的重要教学环节,是实现从学生到专业人才"零过渡"的重要手段。实践教学不仅能够给学生传授知识与技术,培养其分析解决问题的实际能力,而且对他们的思维方式和职业习惯也会产生重要影响。目前,在园林专业教学中,实践教学体系仍存在不少缺漏与不足。结合创业教育理念,构建高职园林实践教学体系,将行业有关信息及时引入到教学中,加强高职园林实践教学体系与企业的横向联系,已势在必行。