蚂蚁筑巢对西双版纳热带森林土壤微生物生物量碳及熵的影响

蚂蚁筑巢能够改变热带森林土壤理化环境,从而对土壤微生物生物量碳及熵的时空动态产生重要影响.本研究以西双版纳高檐蒲桃热带森林群落为对象,采用氯仿熏蒸法对蚂蚁巢地和非巢地土壤微生物生物量碳及熵时空动态进行测定.结果表明: 1)蚁巢地平均微生物生物量碳及熵(1.95 g·kg^-1,6.8%)显著高于非巢穴(1.76 g·kg^-1,5.1%);蚁巢地和非蚁巢地土壤微生物生物量碳呈单峰型时间变化趋势,而土壤微生物熵呈“V”型变化格局.2)蚁巢地和非巢地土壤微生物生物量碳及熵均具有明显的垂直变化:微生物生物量碳随土层加深显著降低,微生物熵则沿土层加深显著升高,但蚁巢微生物生物量碳及熵的垂直变化较非巢穴显著. 3)蚂蚁筑巢引起了巢内水分和温度的显著改变,进而影响土壤微生物生物量碳及熵的时空动态.土壤水分分别解释微生物生物量碳及熵的66%～83%和54%～69%,而土壤温度分别解释土壤微生物生物量碳及熵的71%～86%和67%～76%. 4)蚂蚁筑巢引起土壤理化性质变化对土壤微生物生物量碳和熵产生重要影响.蚁巢土壤微生物生物量碳与土壤有机碳、温度、全氮、含水率呈极显著正相关,与容重、硝态氮,水解氮呈显著正相关,与土壤pH呈极显著负相关;除土壤微生物熵与pH呈显著正相关外,与其他土壤理化指标均呈显著负相关.土壤总有机碳、全氮和温度对微生物生物量碳的贡献最大,而土壤总有机碳和全氮对微生物熵的负作用最小.因此,蚂蚁筑巢能够显著改变微生境(如土壤水分与温度)及土壤理化性质(如总有机碳及全氮),进而调控热带森林土壤微生物生物量碳及熵的时空动态.     

x线断层容积成像技术在肺动脉畸形中的应用

目的：通过与常规x线胸片比较,探讨胸部x线断层容积成像技术在肺动脉畸形中的应用价值。方法：对20例临床及x线平片怀疑肺动脉畸形者,进一步进行胸部x线断层容积成像检查。其中11例被明确诊断为肺动脉畸形。以CT或超声心动结果为标准,对比两种图像对肺动脉畸形的明确诊断率,分析对比该11例患者的胸部x线断层容积成像图片和普通x线胸片,评价两种方法所获得的图像质量和图片优秀率。结果：20例疑似患者中,11例被CT或超声心动确诊为肺动脉畸形,其x线断层容积成像图片和普通x线胸片经主管技师和副主任医师双盲判读,x线断层容积成像11例均获明确诊断（100％）,普通x线胸片明确诊断2例（18％）,诊断准确率有明显差异（P=0．O001）。容积断层成像优质图像为10例,占总数的90．91％;良好1例,差为0例。11例x片中优秀7例,占总数的63．63％,其中良好3例,差1例。两种图像优秀率比较差异有统计学意义（P=0．0001）。结论：x线断层容积成像技术对肺动脉畸形的图像优秀率和诊断准确率均高于x线平片,对病变的显示更加清晰、立体,提高诊断准确率和客观性,具有重要的临床诊断价值。     

Targeting the Shift from M1 to M2 Macrophages in Experimental Autoimmune Encephalomyelitis Mice Treated with Fasudil

We observed the therapeutic effect of Fasudil and explored its mechanisms in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Fasudil, a selective Rho kinase (ROCK) inhibitor, was injected intraperitoneally at 40 mg/kg/d in early and late stages of EAE induction. Fasudil ameliorated the clinical severity of EAE at different stages, and decreased the expression of ROCK-II in spleen, accompanied by an improvement in demyelination and inhibition of inflammatory cells. Fasudil mainly inhibited CD4⁺IL-17⁺ T cells in early treatment, but also elevated CD4⁺IL-10⁺ regulatory T cells and IL-10 production in late treatment. The treatment of Fasudil shifted inflammatory M1 to anti-inflammatory M2 macrophages in both early and late treatment, being shown by inhibiting CD16/32, iNOS, IL-12, TLR4 and CD40 and increasing CD206, Arg-1, IL-10 and CD14 in spleen. By using Western blot and immunohistochemistry, iNOS and Arg-1, as two most specific markers for M1 and M2, was inhibited or induced in splenic macrophages and spinal cords of EAE mice treated with Fasudil. In vitro experiments also indicate that Fasudil shifts M1 to M2 phenotype, which does not require the participation or auxiliary of other cells. The polarization of M2 macrophages was associated with the decrease of inflammatory cytokine IL-1β, TNF-α and MCP-1. These results demonstrate that Fasudil has therapeutic potential in EAE possibly through inducing the polarization of M2 macrophages and inhibiting inflammatory responses.     

功能区胶质瘤患者初级运动皮层激活的偏侧化及运动网络功能连接研究

无运动障碍的功能区胶质瘤患者,其手术风险较高,结合手运动任务态功能磁共振(fMRI)及运动网络功能连接能否更准确的评估手术风险需要进一步探索.本研究收集24例运动功能区胶质瘤且无明显肢体运动功能障碍的患者,非运动功能区胶质瘤患者8例,术前进行fMRI手运动任务态及静息态检查,术后3个月对患者进行随访.计算初级运动皮质(M1)激活的偏侧化指数(lateralization indices,LI).选取运动网络感兴趣区域(ROI),计算双侧M1与各ROI间功能连接系数(FC).运用受试者工作特性曲线(receiver operating characteristic curve,ROC)评估M1激活的LI对术后偏瘫的预测效能.同非运动功能区胶质瘤患者相比,运动功能区胶质瘤患者M1激活LI显著升高(P=0.001).同术后未偏瘫功能区胶质瘤患者相比,术后偏瘫患者M1激活LI值显著升高(P=0.011).ROC曲线下面积(AUC)=0.867,临界点LI=0.31,LI≥0.31对术后偏瘫预测灵敏性为87.5%,特异性为87.5%.以M1激活LI≥0.31将病人分为手术高风险组及低风险组,手术高风险组患者双侧M1与运动网络多个ROI间FC出现显著改变.本研究中功能区胶质瘤患者虽无肢体运动功能障碍,但肿瘤对功能区皮层激活及运动网络FC已有不同程度的破坏;结合任务态及静息态fMRI可以更好地评估手术风险并了解机体功能受损及代偿机制.     

Uropygial gland volatiles may code for olfactory information about sex,individual,and species in Bengalese finches Lonchura striata

Over-shadowed by eye-catching vocal and visual signals,chemical communication has long been overlooked in birds.This study aimed at exploring whether volatile composition of the uropygial gland secretion(UGS)of birds was associated with the information about sex,individual and species.By using dichloromethane extraction and gas chromatography-mass spectrometry(GC-MS),we analyzed the UGS volatiles of domesticated Bengalese finches(Lonchura striata,Estrildiea)which is also known as white-rumped munias.We char...     

火针层孔菌(桑黄)粗多糖对荷瘤小鼠的免疫调节研究

研究了火针层孔菌不同粗多糖对荷瘤小鼠的免疫调节作用。荷瘤小鼠随机分为四组:胞外粗多糖组、菌丝体粗多糖组、子实体粗多糖组和生理盐水阴性对照组。给药10d后测定荷瘤小鼠脾NK细胞活性和脾淋巴细胞的增殖率。结果显示火针层孔菌粗多糖组与阴性对照组相比能够提高小鼠脾NK细胞活性和脾淋巴细胞的增殖率(P<0.01),表明火针层孔菌液体发酵粗多糖和子实体粗多糖对荷瘤小鼠免疫功能均有调节作用。     

Uropygial gland volatiles may code for olfactory information about sex,individual, and species in Bengalese finches Lonchura striata

Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry （GC-MS）, we analyzed the UGS volatiles of domesticated Bengalese finches （ Lonchura striata, Estrildiea） which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages （relative abundances） . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences （degree） of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 （5）： 357-365, 2009].     

红蒴立碗藓愈伤组织的诱导和植株再生

1植物名称红蒴立碗藓（Plryscomitriun eurystomum Sendtn.）,也称尖口立碗藓、广口立碗藓。2材料类别配子体。3培养条件脱毒培养基：Knop（张献龙和唐克轩2004）;愈伤组织诱导培养：MS＋6-BA0．05mg·L-1;再分化培养基：MS。以上培养基均添加2％葡萄糖和1％琼脂。培养温度为（25±1）℃,光照强度为60-80μmol．m-2．s-1,光照时间为12h．d-1。4生长与分化情况4．1无菌材料的获得对采集得到的配子体植株先用75％酒精溶液消毒5S,无菌水清洗1次;再用0．25％新沽尔灭溶液表面消毒10S,无菌水漂洗3次;在无菌滤纸上将材料水分吸干,接种到不添加任何激素的Knop培养基上,培育获得无菌材料（图1）。     

纳米银水凝胶涂膜干预气管导管表面铜绿假单胞菌黏附及生物膜形成的实验研究

目的研究纳米银水凝胶涂膜对气管导管（endotracheal tube,ETT）表面铜绿假单胞菌粘附及细菌生物膜（biofilm,BF）形成的干预作用。方法实验共设6组,分别为空白对照组,涂纳米银3．5、7．0、10．5、14．0和17．5μg／cm^2组。参考Brown平板法,制备ETT、表面铜绿假单胞菌BF模型。通过超声振荡-平板菌落计数法检测体外培养6、12、18h时各组ETT表面BF中的活细菌粘附数量。借助激光共聚焦显微镜观察BF中的活死菌分布情况,并测量BF厚度。结果（1）与空白对照组相比,最小量涂膜组（3．5μg／cm^2）体外培养6h时,导管表面活细菌的粘附量显著减少（P〈0．05）,12h时差异无显著性（P〉0．05）;最大量涂膜组（17．5μg／cm^2）体外培养6h时,ETT表面几乎未见细菌粘附（P〈0．05）,18h时BF中的活菌数量及BF厚度均显著减少（P〈0．05）。（2）激光共聚焦显微镜观察可见,培养6h时,空白对照组ETT表面粘附的死活菌呈不规则散点样分布,未见明显的细菌菌落形成,而各实验组ETT表面仅有细菌零星分布,其数量少于空白组。18h时空白对照组表面可见大量活死菌堆积粘连,有小菌落形成并相互交通成地图状,可见典型BF结构,而此时最大量涂膜组（17．5μg／cm^2）表面仅见数量不等的菌落形成,菌落周围可见数量不等的细菌分布。结论纳米银水凝胶涂膜可有效减少ETT表面铜绿假单胞菌的粘附数量,延缓导管表面细菌BF形成,其作用强弱随培养时间及单位面积中的纳米银剂量的变化而变化。     

酵母细胞自然衰老分子作用机理的研究进展

衰老是任何生物都无法避免的生理现象,它由多种因素引起,其过程极其复杂.酵母细胞是目前衰老研究领域公认的模式生物,一系列影响衰老的分子作用机理及调控因素的发现均源自于对酵母细胞的研究.自然衰老是酵母细胞的衰老模式之一,由于该衰老过程与其他高等真核细胞(特别是哺乳动物细胞)极为相似,近年来受到广泛关注.全面比较酵母细胞衰老的两种模式,详细介绍自然衰老过程中分子作用机理的研究进展,重点阐述其复杂的自然寿命调控通路,包括卡路里限制以及药物添加对Ras/PKA、Sch9、Tor等营养依赖型调控通路的影响,并展望未来该领域需要解决的重要科学问题,为全面深入了解高等生物,特别是人类自身的衰老机理提供参考.