食物对湖北钉螺(Oncomelania hupensis)发育繁殖的影响

用浮游植物(A)、鲫鱼(B)、河蚌(C)、蚯蚓(D)及以浮游植物与3种动物分别混合组成(E、F、G)的7种饲料喂养钉螺,观察其幼螺成活、生长及雌螺产卵量.结果表明,饲料G喂养的钉螺幼螺成活率(43%)明显高于其他饲料(0~33.3%,),B和C喂养钉螺,其幼螺在一个月内全部死亡;在25℃的条件下,饲料A和G喂养的幼螺发育最快,105d其体长分别为6.89mm和6.81mm,且显著长于(P<0.05)饲料D、E、F喂养的钉螺(其体长分别为3.05mm、4.51mm、5.11mm).在25℃的温度条件下饲料A饲养的钉螺产卵时间长、产卵量高(13.9%),与混合型饲料G喂养的钉螺产卵量(14.1%)相当,而明显高于(P<0.05)饲料D、E、F喂养的钉螺(分别为2.9%、10.1%、11.0%);动物型饲料B和C产卵时间短、产卵量最低(不到2%).因此,植物饲料A和混合饲料G适宜于喂养钉螺.     

复合膳食纤维对高胆固醇血症小鼠降脂作用的研究

目的制备复合膳食纤维(Dietary fiber, DF),并探讨其与3种单一的DF对高脂血症小鼠体内脂类含量的影响.方法健康、断乳的NIH小鼠50只,按体质量随机分为5组,用高脂饲料诱发高脂血症同时,分别添加10?:纤维素(B组)、果胶(C组)、海藻酸钠(D组)、纤维素-海藻酸钠复合物(E组),以单纯的高脂饲料组为对照组(A组),8周后,观察各种DF对大鼠的生长发育及脂类代谢的影响.结果与对照组相比各种DF皆可不同程度降低大鼠脂质水平,且以复合物效果最佳.结论各种DF皆可不同程度降低大鼠体内的脂类含量,复合DF效果优于单一的DF.     

缺铁孕鼠子代肝脏EPO及EPOR的mRNA表达及意义

目的观察缺铁性贫血大鼠对其子代鼠肝脏中促红细胞生成素(erythropoietin,EPO)及促红细胞生成素受体(erythropoietin receptor,EPOR)的m RNA表达水平的影响,并探讨其变化意义。方法 36只4周龄的雌性Wistar大鼠随机分为2组进行饲养,实验组18只雌性Wistar大鼠给予低铁饲料喂养,构建缺铁性贫血大鼠模型。对照组18只雌性Wistar大鼠给予正常饲料喂养。实时荧光定量PCR检测两组大鼠各自子代新生仔鼠肝脏中EPO、EPOR的m RNA表达水平。结果 (1)低铁喂养后,实验组18只雌性Wistar大鼠血红蛋白、红细胞比容、红细胞平均体积、红细胞平均血红蛋白量均低于对照组,差异有统计学意义(P0.001),红细胞分布宽度高于对照组大鼠,提示缺铁性贫血大鼠模型造模成功;(2)实验组大鼠产仔数量较少,后代仔鼠出现缺铁性贫血症状,仔鼠体型较小,皮肤苍白;(3)实验组与对照组相比,实验组大鼠子代肝脏EPO m RNA表达水平上调,差异有统计学意义(P0.01);(4)与对照组相比,实验组大鼠后代肝脏EPOR m RNA表达水平没有统计学差异(P0.05)。结论铁缺乏大鼠子代出现一定程度的缺铁性贫血症状,缺铁性贫血大鼠对其后代仔鼠肝脏EPO m RNA表达水平有上调作用。     

转基因抗矮花叶玉米对雄性大鼠脾脏、胸腺和睾丸组织形态学的影响

为了观察转基因抗矮花叶玉米对雄性大鼠免疫器官脾脏、胸腺组织和生殖器官睾丸组织形态的影响.本实验将80只雄性SD大鼠随机分为4组,即33%非转基因玉米组(C1)、33%转基因玉米组(M1)、50%转基因玉米组(C2)、50%转基因玉米组(M2),相应饲料喂养90d,比较各组雄性大鼠免疫器官和生殖器官形态的改变情况.结果:M1,M2组大鼠脾脏、胸腺和睾丸组织与C1,C2相比,组织的显微结构未见明显的病理变化.结论:用含有33%和50%的转基因玉米的饲料饲喂大鼠,对其免疫和生殖器官的组织形态学基本没有影响.     

添加乳酸菌人工饲喂幼鸽效果研究

找出母鸽自然喂养和人工饲料喂养效果的差异,探索人工饲喂乳鸽的科学方法,提高乳鸽的生长速度和成活率。将3日龄的乳鸽随机分为4组,A组和D组分别为自然喂养组和常规饲养对照组,B组和C组为分别添加5×107个/mL和2.5×107个/mL乳酸菌的饲喂组。饲喂周期为15d,第1~6d时,每天喂8次,以注射器灌喂;第7~15天时,每天喂5次,以糊状物或泥巴样物投喂。观察并统计幼鸽的生长速度及成活率。结果表明自然喂养效果优于人工饲喂,用添加乳酸菌的饲料人工喂养效果(B组平均体重349.86g,成活率70%、C组平均体重304.86g,成活率60%)虽低于自然喂养的水平(A组平均体重448.00g,成活率96%),但优于不含乳酸菌的饲料的饲喂效果(D组平均体重277.67g,成活率60%),表明乳酸菌对促进乳鸽的正常发育具有一定作用,且浓度越大效果越明显。该研究结果为人工饲喂乳鸽提供了科学依据。     

小檗碱对糖尿病大鼠脑内与血中Aβ的影响

通过建立高脂联合STZ诱导糖尿病大鼠模型,旨在探讨小檗碱对大鼠脑内与血中β样淀粉蛋白的影响.选用Wistar雄性大鼠,高脂饲料喂饲8周后,腹腔注射1%链脲佐菌素(35mg/kg)复制糖尿病大鼠模型.成模后,将模型大鼠按体重和血糖值随机分为5组:模型组、对照组、小檗碱高剂量组(H,129.45mg/kg·d)、低剂量组(L,64.72mg/kg·d)和阳性对照吡咯列酮组(PIO,2.72 mg/kg·d).连续灌胃给药8周后处死,分离血清及脑组织.采用比色法观察大鼠空腹葡萄糖,放免法检测胰岛素含量;酶联免疫法检测大鼠血清和脑组织中Aβ水平.与空白组相比,大鼠高脂喂养8周体重呈非常显著性增加(P0.01);高脂喂养8周时大鼠FPG、INS显著性升高(P0.01或P0.05),IAI显著性降低(P0.05),表明已诱发大鼠产生胰岛素抵抗.与空白组相比,糖尿病大鼠血中及脑内Aβ均显著性增加(P0.01或P0.05);与模型组比较,药物干预8周后,小檗碱高剂量显著性降低脑内和血中Aβ的质量浓度(P0.01).高脂喂饲8周联合STZ 35mg/kg能成功复制以IR为基础伴有高糖的大鼠模型;小檗碱高剂量能显著性降低糖尿病大鼠脑内与血中Aβ的质量浓度.     

啤酒对胃壁肌间神经丛影响的酶组织化学研究

目的:探讨啤酒对胃壁肌间神经丛神经元功能的影响。方法:将20只刚断乳昆明种(清洁级)小鼠随机分为两组,A组(10只)饲以标准饲料,强制以啤酒为饮料,B组(10只)饲以标准饲料,自由饮清水。经2周喂养后处死,取小鼠胃体部胃壁做SDH、LDH、ACP酶组织化学检测及HE常规染色。结果:(1)A、B组小鼠胃壁均无明显组织学损害。(2)A组肌间神经丛SDH强阳性(+++)者占总数的45.1%,中等阳性(++)者占54.9%;B组肌间神经丛SDH强阳性(+++)者占总数的41.5%,中等阳性(++)者占58.5%;(3)A组肌间神经丛LDH中等阳性(++)者为63.9%;阳性(+)者为36.1%;B组肌间神经丛LDH中等阳性(++)者占总数的67.7%,阳性(+)者占32.3%;(4)A组ACP显示弱阳性(±)者占总数的56.5%;其余为阴性(),占总数的43.5%;B组弱阳性(±)者占总数的57.7%;其余为阴性(),占总数的42.3%;(5)A、B两组尼氏体(Nissl'sbody)显示中等阳性(++)。结论:A组与B组对比,在小鼠断乳至发育成熟的生长敏感时期饮用啤酒,小鼠胃壁组织结构无明显组织学损害;小鼠胃肌间神经丛神经元的有氧代谢和无氧酵解无明显变化;小鼠胃肌间神经丛神经元无明显受损。     

长期游泳运动对高脂饲料喂养大鼠肝脏中CYP7A1及D-双功能蛋白表达的影响

探讨长期耐力运动对高脂饲料喂养的大鼠胆汁酸生成关键酶CYP7A1和D-双功能蛋白(DBP)表达的影响.30只大鼠随机分为高脂组(HC)、高脂运动组(HE)、正常组(C).高脂组和高脂运动组采用高脂饲料喂养.高脂运动组喂养4周后,进行16周的游泳运动.20周后,测定三组大鼠肝脏中CYP7A1和DBP的表达,血清中生化指标的变化以及粪便中的胆汁酸,并取肝脏作病理切片分析.测定结果显示,高脂运动组较高脂组肝脏的脂肪变性明显好转,血清中chol、TG、LDL、CP均趋向正常;高脂运动组肝脏中CYP7A1、DBP的表达明显增加.长期耐力运动能够使高脂喂养大鼠肝脏中CYP7A1、DBP表达显著增加,增加大鼠胆汁酸的产生和排泄,减轻高脂饲料喂养导致的脂类代谢失调.     

补肾醒脑方对血管性痴呆大鼠脑组织中黏附分子的影响

观察补肾醒脑方对血管性痴呆大鼠脑组织中黏附分子的影响,探讨该方对血管性痴呆大鼠脑的保护作用。经成年Wistar大鼠筛选、造模后随即等分为假手术组(A组)、模型组(B组)、喜得镇组(C组)、补肾醒脑方组(D组),每组10只均灌胃给药。A组和B组采用蒸馏水,C组给予喜得镇,D组给予补肾醒脑方。术后第2 d、4 d、6 d测试大鼠学习记忆能力;术后1W采用ELISA法检测大鼠脑组织中黏附分子ICAM-1、VCAM-1、P-selectin、E-selectin的含量。D组AAR习得率较B组各个时间点均明显提高;与B组相比较,ICAM-1、P-selectin含量差异极其显著(P0.01)。补肾醒脑方可有效改善血管性痴呆大鼠的学习记忆能力,控制下调黏附分子的含量,降低血管的炎性反应,从而保护大脑组织。     

5'-核苷酸对小鼠获得性免疫调节作用研究

 为了评价5’-核苷酸对小鼠获得性免疫功能的影响,将健康雌性BALB/c小鼠以普通饲料、无核苷酸饲料（NF）及不同剂量5’-核苷酸的饲料（0.0025%,0.01%,0.04%,0.16%）喂养4周后,观察小鼠细胞免疫功能、体液免疫功能、血清免疫球蛋白水平以及脾脏淋巴细胞亚群的改变。结果显示无核苷酸饮食可以显著减弱淋巴细胞增殖能力（OD差值0.06±0.03）和足跖肿胀度（0.12±0.06）mm;CD4+/CD8+（1.90±0.12）显著下降,T调节细胞比例（5.56±0.11）%显著升高;溶血空斑数（1.48±0.21）有减弱趋势。饲料中添加5’-核苷酸后,免疫水平有所回升。当添加到0.04%时,小鼠的各项免疫水平均比NF组有显著提高,达到正常对照组水平。总之,无核苷酸饲料喂养小鼠免疫功能降低。在无核苷酸饲料中添加5’-核苷酸能恢复小鼠免疫功能,当饲料中核苷酸含量为0.04%时小鼠免疫功能恢复到最佳水平。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the