水青树特殊管胞的分布位置及其形态特征的研究

针对水青树（Tetracentron sinense）中一类特殊管胞进行较为全面的观察研究,判断细胞种类并分析维管组织输导机理及树木进化过程中的细胞演化规律。通过切片和解离技术,借助光学显微镜和电子显微镜对34年生水青树特殊管胞的分布位置和形态特征进行观察。结果表明：(1)特殊管胞在树木水平方向自内向外径向呈串排列,并贯穿年轮界限,多为一列,少数两列,且较为稀见。每个特殊管胞弦向左右两侧或单侧均与木射线细胞相连通。纵向上,特殊管胞单独或数个上下端接相连。(2)特殊管胞主要有以下3种类型：无端壁的纺锤形,有一个倾斜端壁,以及有两个倾斜端壁。特殊管胞的平均长度为286.44μm;横切面为四边形,平均弦向宽度为55.22μm,其平均壁厚为1.53μm。(3)特殊管胞两端封闭,无穿孔。(4)特殊管胞侧面壁上的纹孔数量较多且纹孔膜明显可见,具体表现为：弦面壁上布满特殊管胞之间的具缘纹孔,呈对列、互列偶见梯状排列;径面壁上存在与射线细胞间的具狭缘单纹孔,呈大圆形至椭圆形,每区域多为2～10个纹孔,呈1～4排横列;径面壁上与正常管胞间几无纹孔。水青树特殊管胞分布有一定规律,其长度远小于水青树正常管胞...     

水杉年轮宽度和管胞形态径向变异研究

采用木材切片法和光学显微技术,研究了四川省雅安市中里地区水杉木材年轮宽度和管胞的长度、壁厚、腔径等指标的径向变异。结果表明:(1)年轮宽度在髓心至第10年先迅速增加,然后呈下降趋势,速生期约15 a,晚材率低;(2)管胞长度随轮龄的增加而增大,13 a后增幅变缓,早材管胞长度小于晚材管胞,根据管胞长度判断实验水杉木材即将进入成熟期;(3)管胞宽度在轮龄10 a前增长迅速,幅度明显减慢,管胞宽度44.6μm,壁厚7.23μm,腔径37.48μm,早、晚材间管胞宽度、壁厚、腔径差异显著;(4)管胞长宽比95.4、壁腔比0.27、腔径比0.82,水杉木材是优良的造纸原料。     

增施CO_2对温室番茄结果期叶片光合特性的影响

针对日光温室冬春季生产CO_2匮缺严重的现象,以不增施CO_2[(400±25)μmol·mol~(-1)(C0)]为对照,研究增施不同浓度CO_2[(600±25)μmol·mol~(-1)(C_1)、(800±25)μmol·mol~(-1)(C_2)、(1000±25)μmol·mol~(-1)(C_3)]对番茄‘兴海12号’结果期光合色素、净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、胞间CO_2浓度(C_i)以及水分利用率(WUE)等光合特性的影响,旨在明确北方地区日光温室番茄结果期适宜的CO_2浓度,为番茄的生产实践提供理论依据。结果表明:增施不同浓度CO_2后,番茄结果期叶片光合色素含量均明显增加;P_n、C_i和WUE显著提高;G_s和T_r显著下降;且CO_2浓度为(1000±25)μmol·mol~(-1)时效果最佳。增施(1000±25)μmol·mol~(-1)CO_2能有效改善番茄结果期叶片光系统、增强其光合作用,有利于番茄的生长发育。     

甘利欣联合阿奇霉素治疗支原体肺炎伴肝功能损害患儿的效果 及对血清炎症因子、KL-6 及NF-κB 水平的影响

目的:探讨甘利欣联合阿奇霉素治疗对支原体肺炎伴急性肝功能损害患儿血清炎症因子、Ⅱ型肺泡表面抗原-6(KL-6)及核因子-κB(NF-κB)水平的影响。方法:选取86例支原体肺炎伴急性肝功能损害患儿为受试对象,随机数字表法分成研究组和对照组各43例。对照组中途脱落1例,共42例有效病例入组,予以常规对症治疗+阿奇霉素疗法;研究组中途脱落3例,共40例有效病例入组,在对照组治疗基础上联合甘利欣静脉滴注疗法。观察对比两组受试患儿治疗前后血清炎症因子[白细胞介素-6(IL-6)、白细胞介素-12(IL-12)及肿瘤坏死因子-α(TNF-α)]、血清KL-6、血清NF-κB、肝功能指标[血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(TBIL)]变化情况,记录其发热、咳嗽、肺部湿罗音等消失时间差异。结果:治疗4w后,两组患儿IL-6[(44.5±6.2)pg/m L vs(60.3±6.6)pg/m L]、IL-12[(42.4±6.2)pg/m L vs(52.1±6.8)pg/m L]、TNF-α[(128.6±44.8)ng/L vs(201.4±51.8)ng/L]等血清炎症因子检测结果、ALT[(46.8±9.5)U/I vs(83.6±9.8)U/I]、AST[(62.2±10.1)U/I vs(84.8±10.2)U/I]、TBIL[(38.2±8.5)μmol/L vs(49.3±9.0)μmol/L]等肝功能指标检测结果及血清KL-6[(5.9±0.6)pg/m L vs(6.5±0.7)pg/m L]、NF-κB[(7.8±0.4)pg/m L vs(8.1±0.3)pg/m L]水平均较治疗前显著降低,且研究组小于对照组,差异有统计学意义(P0.05)。研究组患儿治疗后发热、咳嗽、肺部湿罗音等消失时间均显著短于对照组患儿,差异有统计学意义(P0.05)。结论:甘利欣联合阿奇霉素疗法可在促进支原体肺炎伴急性肝功能损害患儿病情转归、改善其血清炎症因子、调节肺功能、肝功能状态等方面发挥积极作用。     

裸子植物木材交叉场纹孔的电镜观察研究

本文介绍了扫描电镜和透射电镜下交叉场纹孔在管胞一侧和射线薄壁细胞一侧的形态特征及其变化细节,扫描电镜下管胞胞腔一侧交叉场纹孔口周围形成的光晕,在柳杉（Cryptomeris fortunei Hooibrenk ex Otto et Dietr.)木材中首次看到管胞一侧的交叉场纹孔膜具辐射状排列的微纤丝或束;西藏长叶松（Pinus roxburghii Sarg.)的松木型纹孔膜的边缘具辐射状排列的微纤丝束,此外,尚在臭冷杉[Abies nephrolepis(Trautv.)Maxim.]木材中观察到一种特殊的纹孔口外展的杉木型纹孔,并在冷杉属（Abies)其他种,落叶松属（Laricx)一些种及红皮云杉（Picea Koraiensis Nakai)等木材的交叉场纹孔中也看到。     

水松的细胞学研究

本文报道了水松的核型公式K(2n)=22=22m,为“1A”类型。染色体相对长度组成为2n=22=2L+4M_2+16M_1。8号染色体具长着丝点区域,这是核型的一个特征。与近缘的国产种柳杉和水杉相比较。三者由原始到进化的顺序可能为(柳杉、水松)、水杉,水松与柳杉最接近,水杉和水松较近缘。本文还计算了水松的染色体体积。     

拟胆碱药物对金环蛇、银环蛇毒中毒小鼠的解毒活性研究

目的测定拟胆碱药物对金环蛇、银环蛇毒中毒小鼠是否具有解毒活性。方法于昆明小鼠腹腔注射800μg/kg金环蛇毒(1.8×LD_(50))或50μg/kg银环蛇毒(1.4×LD_(50)),2 h后于腹腔注射生理盐水或不同剂量拟胆碱药物,观察24 h内对照组及拟胆碱药物组的小鼠死亡时间及死亡率,统计分析拟胆碱药物组是否具有解毒活性。结果注射金环蛇毒后,生理盐水组小鼠的死亡时间为[(3.64±1.03)～(5.08±1.27)]h,死亡率为70.0%～100%。溴吡斯的明组(62.5、125、250μg/kg),甲硫酸-新斯的明组(62.5、125、250μg/kg),毒扁豆碱组(62.5、125、250μg/kg)及石杉碱甲组(62.5、125、250μg/kg)的小鼠死亡时间分别为[(4.45±0.94)～(6.48±3.27]h、[(2.79±0.74)～(4.17±1.44)]h、[(3.74±2.21)～(5.62±2.47)]h及[(4.43±2.55)～(4.62±1.49]h;醋甲胆碱组(5、20、80μg/kg),氯贝胆碱组(5、20、80μg/kg),他克林组(250、500、1000、2000μg/kg),加兰他敏组(125、250、500、1000、2000μg/kg)及多奈哌齐组(500、1000、2000μg/kg)的小鼠死亡时间分别为[(4.59±1.90)～(5.30±2.18)]h、[(3.25±0.75)～(4.53±1.72)]h、[(5.09±2.57)～(5.66±2.63)]h、[(3.48±0.80)～(5.30±2.51)]h及[(3.25±1.47)～(4.67±1.51)]h,各给药组的死亡时间及死亡率(80%～100%)与对照组比较无明显差异(P0.05)。与对照组相比,银环蛇毒各给药组小鼠的死亡时间及死亡率亦无明显差异性(P0.05)。结论拟胆碱药物不能显著延长金环蛇、银环蛇毒中毒小鼠的死亡时间或提高生存率,无显著解毒活性。     

尖形碘泡虫(黏体门:碘泡虫科)的重描述及其分子系统学研究

研究基于形态和分子信息重描述了寄生于嘉陵江重庆段鲫(Carassius auratus Linnaeus)鳃部和胆囊的尖形碘泡虫(Myxobolus acutus Wu and Chen, 1987),并获得了该虫体的18S rDNA和ITS1 rDNA序列。尖形碘泡虫成熟孢子壳面观呈梨形,前端稍尖,后端钝圆,缝面观呈宽纺锤形。孢子长(13.6±0.9)μm [(11.4—15.3)μm],宽(10.2±0.9)μm [(7.5—12.8)μm],厚(7.6±0.6)μm [(6.9—8.3)μm]。两梨形极囊开口处紧靠并位于孢子前端,极囊大小不等,大极囊长(6.2±0.4)μm [(5.1—7.5)μm],宽(3.8±0.4)μm [(2.8—4.7)μm],极丝盘绕5—8圈,小极囊长(2.7±0.4)μm [(1.7—3.7)μm],宽(1.4±0.2)μm [(0.9—1.9)μm],极丝盘绕2—3圈。基于18S rDNA为分子标记的系统发育分析显示:尖形碘泡虫与中华单极虫(Thelohanellus sinensis)有最近的亲缘关系,两物种形成的进化支与贝壳碘泡虫(M. mu...     

脐血IL-6、IL-8、TNF-a在早产儿脑损伤中的临床意义及预测价值

目的研究脐血白介素-6(IL-6)、白介素-8(IL-8)和肿瘤坏死因子-a(TNF-a)在34周前早产儿脑损伤中的临床意义及预测价值。方法对59例34周前出生早产儿用酶联免疫吸附试验检测脐血IL-6、IL-8、TNF-a;将母亲的胎盘胎膜组织行病理学检查,诊断有无绒毛膜羊膜炎;早产儿出生后72 h内头颅超声检查,诊断有无脑损伤。结果 (1)早产儿脑损伤组脐血IL-6[(7.69±1.69)μg/L]、IL-8[(3.87±0.26)μg/L]及TNF-a[(3.67±1.12)μg/L]明显高于无脑损伤组[分别为(5.78±0.59)μg/L、(1.79±0.66)μg/L、(1.91±0.37)μg/L],2组比较差异有统计学意义(P<0.05);母亲患绒毛膜羊膜炎组脐血IL-6[(6.98±0.17)μg/L]、IL-8[(3.27±0.27)μg/L]和TNF-a[(3.24±1.37)μg/L]明显高于无绒毛膜羊膜炎组[分别为(6.13±0.15)μg/L、(2.04±0.79)μg/L、(2.07±0.54)μg/L],2组比较差异有统计学意义(P<0.05);(2)应用ROC工作曲线进行分析,脐血IL-6≥6.46μg/L、IL-8≥2.0μg/L、TNF-a≥2.42μg/L作为诊断早产儿脑损伤标准时,其灵敏度分别为95.5%、95.5%和100%;特异度分别为94.6%、70.3%和97.3%;(3)母亲有绒毛膜羊膜炎时,早产儿脑损伤发生率明显升高。结论脐血IL-6、IL-8和TNF-a不仅反映母亲的感染情况和早产儿脑损伤,并且对早产儿脑损伤具有一定的预测价值。     

北京山区典型暖温带落叶阔叶林大气CO_2浓度、草本层光合作用及土壤释放CO_2变化特点(英文)

为探讨森林生态系统植被、土壤等不同组分与大气CO_2交换特点,利用中型同化箱(40cm×40cm×2Ocm)及红外CO_2分析仪装置对北京山区典型暖温带森林生态系统辽东栎(Quercus liaotungensisKoidz.)林草本层净光合作用、土壤释放CO_2及林外(高出林冠2m)与林内(低于林冠2m)大气CO_2变化进行测定。结果表明:夏季及秋季大气CO_2浓度分别为(323±10)μmol·mol~(-1)和(330±1)μmol·mol~(-1);在一天内连续24h的测定中,大气与林内CO_2浓度的差值最大时可分别达-46和-61μmol·mol~(-1)。夏季草本层净光合强度为(2.59±1.05)μmol CO_2·m~(-2)·s~(-1),是秋季((1.31±0.39)μmol CO_2·m~(-2)·s~(-1))的2倍;夏季土壤呼吸释放CO_2的强度明显高于秋季,分别为(5.18±0.75)μmol CO_2·m~(-2)·s~(-1)和(1.96±0.57)μmol CO_2·m~(-2)·s~(-1)。土壤释放CO_2强度与地面温度之间存在显著相关,其关系式为Y=-0.8642 0.3101X(r=0.7164,P<0.001,n=117)。大气CO_2浓度的低值及草本层光合强度高值约出现在14:00左右;而在夜间土壤释放CO_2强度增加,表现为大气CO_2浓度升高。     

Ester production in E. coli and C. acetobutylicum

Genetic engineering has improved the product yield of a variety of compounds by overexpressing, inactivating, or introducing new genes in microbial systems. The production of flavor-enhancing ester compounds is an emerging area of heterologous gene expression for desired product yield in Escherichia coli. Isoamyl acetate, butyl acetate, ethyl acetate, and butyl butyrate are reported here to be produced by expressing Saccharomyces cerevisiae genes ATF1 or ATF2 and the strawberry gene SAAT in E. coli when the appropriate substrates are provided. Increasing the concentration of alcohol added to the reaction generally resulted in increased ester production. ATF1 expression was found to produce more isoamyl acetate and butyl acetate than ATF2 expression or SAAT expression in the strains and culture conditions examined. Additionally, SAAT expression resulted in greater isoamyl acetate and butyl acetate production than ATF2 expression. Butyl butyrate is produced by cell-free extracts of E. coli harboring SAAT but not ATF1 or ATF2.     

Chemical composition, in situ ruminal degradability and post-ruminal disappearance of dry matter and crude protein from the halophytic plants Kochia scoparia, Atriplex dimorphostegia, Suaeda arcuata and Gamanthus gamacarpus

Samples of Kochia (K. scoparia), Atriplex (A. dimorphostegia), Suaeda (S. arcuata) and Gamanthus (G. gamacarpus) were collected and analyzed for chemical composition including crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDFom), acid detergent fiber (ADFom), non-protein N (NPN), Ca, P, Na, K, Cl, Mg, Fe, Cu and Se. In addition, in situ ruminal degradability and post-ruminal disappearance of dry matter (DM) and CP of the samples using a mobile bag technique were determined. Results indicate that the chemical composition of Kochia and Atriplex was notably different from those of Suaeda and Gamanthus. All of these halophytic plants had high concentrations of Na, K, Cl, Cu and Se, and low levels of Ca, P and Mg. The rapidly degradable fractions of DM and CP (g/g) of Kochia (0.31 and 0.35, respectively) and Atriplex (0.39 and 0.50, respectively) were lower than for Suaeda (0.53 and 0.55, respectively) and Gamanthus (0.56 and 0.66, respectively). Ruminal DM and CP disappearance of Kochia (444 and 517 g/kg, respectively) and Atriplex (472 and 529 g/kg, respectively) were lower (P<0.05) than those of Suaeda (553 and 577 g/kg, respectively) and Gamanthus (663 and 677 g/kg, respectively) (P<0.05) using the mobile bag technique. Suaeda had the lowest (P<0.05) NDFom and ADFom disappearance (214 and 232 g/kg, respectively) in the rumen. Kochia scoparia and Atriplex dimorphostegia have more beneficial chemical nutritive components and digestible values versus Suaeda arcuata and Gamanthus gamacarpus.     

Flavonoids of Astilbe and Rodgersia compared to Aruncus

The flavonoid profiles of Astilbe (four taxa studied) and Rodgersia (two taxa studied) are based on simple flavonol glycosides. Astilbe has 3-O-mono-, 3-O-di-, and 3-O-triglycosides of kaempferol, quercetin, and myricetin, while Rodgersia has only mono- and diglycosides of kaempferol and quercetin. Astilbe×arendsii was also shown to accumulate dihydrochalcone glycosides. The flavonoid profile of Rodgersia is the simplest recorded so far in the herbaceous Saxifragaceae. The flavonoids of two species of Aruncus were shown to be based upon kaempferol and quercetin 3-O-mono- and 3-O-diglycosides. One of the species also exhibited an eriodictyol glycoside. The triglycoside differences were not considered important, but the differences in myricetin occurrences were taken as evidence against derivation of Saxifragaceae from an Aruncus-like ancestor. Should such an event be proposed, however, serious consideration would have to be given to the current pattern of myricetin occurrence in the two families.     

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila

Background  

The Zaprionus genus shares evolutionary features with the melanogaster subgroup, such as space and time of origin. Although little information about the transposable element content in the Zaprionus genus had been accumulated, some of their elements appear to be more closely related with those of the melanogaster subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the Gypsy and the Micropia retroelements were chosen for screening in seven species of the two Zaprionus subgenera, Anaprionus and Zaprionus.     

百合LbCAT和LbGPX基因的克隆与表达分析

以切花百合(Lilium brownii var. viridulum)‘卡瓦纳’cDNA为模板,克隆了过氧化氢酶(LbCAT)和谷胱甘肽过氧化物酶(LbGPX)基因。序列分析表明,这2个基因分别包含1 479 bp和519 bp的开放阅读框(ORF),编码492个和172个氨基酸。进化分析结果表明,LbCAT蛋白与岷江百合CAT蛋白的氨基酸序列相似性最高(99.19%),且亲缘关系最近;LbGPX蛋白与油棕GPX蛋白的氨基酸序列相似性最高(78.61%),亲缘关系最近。qRT PCR结果显示,LbCAT和LbGPX在百合根、鳞茎、叶和花中都有表达。LbCAT在叶中表达量最高,LbGPX在花中表达量最高。这2个基因在百合花蕾的生长发育过程中均有表达,且表达量逐渐增加;在PEG处理后2个基因的转录水平升高,但独角金内酯(SLs)处理却显著降低了这2个基因的转录水平;该结果为百合抗逆性机理研究以及抗逆育种奠定了基础。     

Cloning and characterization of femA and femB from Staphylococcus epidermidis

A DNA fragment was identified and cloned from Staphylococcus epidermidis (Se) using femA from S. aureus (Sa) as a heterologous hybridization probe. DNA sequence analysis of a portion of this clone revealed two complete ORFs highly related to femA and femB of Sa. The genomic arrangement of the Se femA/B complex was nearly identical to that observed in Sa. Intra- and interspecies relatedness of these genes and conservation of genomic organization were consistent with gene duplication of one of these genes in an ancestral organism. Recombinant FEMA, produced in Escherichia coli (Ec), was purified to near homogeneity. Identity of the purified protein was verified by N-terminal amino acid (aa) sequence analysis.