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1.
On hatching from the egg, a larva of Lepidosroma hirtum Curtis constructed a tubular, sand grain case. As the larva became older it periodically added new material to the anterior of the case and, once in every instar except the 1st, cut off ⅓ to ¼ of the posterior of the case. In the 3rd instar the larva changed from adding sand grains to cutting out and attaching almost rectangular leaf panels. By the 5th instar the case was composed entirely of leaf panels. The case was then square in section and composed of one row of panels for each of the sides. The panels were not truly rectangular but convex on the leading edge and sides and concave at the back, so that the anterior convexity of one panel fitted into the posterior concavity of the panel in front. Panels were arranged with their long axes across the case. The seams between panels in the roof were half a panel length out of phase with those in the sides but in phase with those in the floor. The convex sides of a panel allowed it to overlap the seams between panels on the two adjacent sides. If a 5th instar larva was removed from its case it first built a sand grain case followed by a leaf panel case. The animal cut panels from the leaf with its mandibles and then further shaped them by chewing round the edge. Just prior to pupation, the case was modified by the attachment of further panels to the anterior; these included panels which for the first time in the life of the larva were arranged with their long axes along the case.  相似文献   

2.
Heterogeneity of big-big hPRL in hyperprolactinemia   总被引:1,自引:0,他引:1  
Sera from a patient with macroprolactinoma (case 1) and from a hyperprolactinemic woman with regular menstruation (case 2) were analyzed for prolactin activity by gel filtration using Sephadex G-100, Sephadex G-200 and TSK G3000SW columns. The chromatographic profile by Sephadex G-100 showed that the percentage of immunoreactive big-big hPRL was 10.7% in case 1 and 64.1% in case 2. On Sephadex G-200 and TSK G3000SW columns, the molecular weight of big-big hPRL was estimated to be more than 500,000 daltons (big-big1 hPRL) in case 1 and approximately 250,000-300,000 daltons (big-big2 hPRL) in case 2. Big-big1 hPRL in case 1 was converted to big and little hPRLs when the serum was treated with 2-mercaptoethanol (2-ME), but part of the big-big2 hPRL in case 2 was converted to a larger molecule. Radioactive big-big hPRL generated by mixing labeled hPRL with the serum from case 1 was eluted with the void volume on Sephadex G-100 column and was not converted to the other molecular forms after 2-ME treatment. There were two radioactive big-big hPRL on TSK G3000SW column and these estimated molecular weights were more than 300,000 daltons. The data demonstrated the existence of at least two forms of big-big hPRL in the serum and indicated that radioactive big-big hPRL may be different from these hPRLs in the serum.  相似文献   

3.
The widely anticipated economic potential of fed-batch operation was quantified for a therapeutic product by flowsheet simulation. A process for production of t-PA from CHO cells based on fed-batch operation was compared to a base process that operates in batch mode. Two cases of fed-batch operation were considered, case A, where the product concentration was assumed to be four times the concentration obtained with base process and case B, where the concentration was eight times. The simulator, Bioprocess Simulator (BPS) from Aspen Technology, reported the final bioreactor volume and the total amount of the continuous feeds added during the fed-batch operation. BPS was also used to simulate the downstream processes. Comparison of the economic performances of the processes revealed that return on investment (ROI) of the base process would increase by 112% by switching to case A fed-batch operation from batch mode. Case B, on the other hand, would result in an increase of 288%. The importance of downstream processing for recovery of high-value products became apparent from this study. A breakdown of equipment purchase cost showed that the contribution from the product recovery section increased from 62% for base case to 77% for case A as the product concentration increased by fed-batch operation. For a fixed recovery of 40%, contribution from the downstream section was found to decrease to 70% for case B compared to case A. It was concluded from the results that higher product concentration would not result in proportionate increase in ROI because of limitations in the recovery section. A sensitivity analysis was carried out on several uncertainties of the simulated fed-batch process.  相似文献   

4.
The silk egg case and orb web of spiders are elaborate structures that are assembled from a number of components. We analysed the structure, the amino acid and fibre compositions, and the tensile properties of the silk fibres of the egg case of Nephila clavata. SEM shows that the outer and inner covers of the egg case consist of thick, medium and thin silk fibres. The silk fibres of the outer cover of the egg case are probably produced by the major and minor ampullate glands. The silk fibres of the inner cover of the egg case from cylindrical glands appears to be distinct from the silk fibres of the major ampullate glands based on their micro-morphology, mole percent amino acid composition and types, and tensile behaviour and properties. Collectively, our investigations show that N. clavata uses silk fibres from relatively few glands in varying combinations to achieve different physical and chemical properties (e.g., color, diameter, morphology and amino acid composition) and functional and mechanical properties in the different layers of the egg case.  相似文献   

5.
The economy of scaling-up a bioreactor by increasing the number of units was investigated with respect to an integrated flowsheet. For the production of t-PA from animal cells, a base case flowsheet using a single large bioreactor was compared to a multiple bioreactor case. Simulation of the complete flowsheets for the two cases showed that a multiple bioreactor approach to scale-up increases the return of investment (ROI) of the base process by 122%. This enormous increase in ROI results from the smaller size of the downstream units compared to the base case, since downstream processing accounts for about 80% of the total cost for high value products like t-PA. Proper scheduling of the downstream units allowed sharing of the equipment by the bioreactors. A breakdown of the equipment purchase cost showed that cost related to cell culture equipment increased from 14% for the base case to about 37% for the multiple bioreactor case. The contribution from chromatography columns to the total equipment purchase cost, on the other hand, decreased from 52 to 33%.  相似文献   

6.
General factors determining the possibility of application of peptide maps in thin layer of microcrystalline cellulose as a micropreparative method in molecular diagnostics of abnormal hemoglobins were studied. The effects of absorbtional capacity of cellulose and amino acid impurities in it, choice of eluent and elution technique, peptide structure and extent of its modification in staining as well as completeness and specificity of globin chain enzymatic digestion on peptides extraction from thin layer were analysed. The results of structural identification of Hb D Punjab beta 121 Glu----Gln at a Cypriot; Hb O Arab; beta 121 Glu----Lys at a Bulgarian woman, living in Kalinin region (the second case in the USSR); Hb M Saskatoon beta 63 His----Tyr at a woman from Georgia (the second case in the USSR); Hb Buenos Aires beta 85 Phe----Ser at a Russian girl (the first case in the USSR and the third case in the world); Hb Dagestan alpha 60 Lys----Glu at two members of a Lesgin family from Dagestan; Hb Agenogi beta 90 Glu----Lys at a Hungarian woman; Hb Setif alpha 94 Asp----Tyr at three patients from Cyprus and Hb Detroit beta 95 Lys----Asn at an Azerbaijanian woman (the first case in the USSR and the second case in the world) are presented.  相似文献   

7.
目的分别报道国内少见的由尖端赛多孢导致的化脓性关节感染伴骨髓炎和多育赛多孢的血行播散感染。方法取患者1的关节冲洗液和患者2的外周血标本直接涂片和真菌培养,根据真菌培养的菌落特点和镜下形态,鉴定致病菌种,并对分离的致病菌进行体外药敏试验。结果两个病例分别培养出尖端赛多孢和多育赛多孢。体外药敏试验显示两种菌对伏立康唑有较低的MIC值,而都对两性霉素B高耐。结论赛多孢菌的感染少见,且难治疗。应加深对少见真菌病的认识,提高诊治水平。  相似文献   

8.
Integer multiple neural firing patterns exhibit multi-peaks in inter-spike interval (ISI) histogram (ISIH) and exponential decay in amplitude of peaks, which results from their stochastic mechanisms. But in previous experimental observation that the decay in ISIH frequently shows obvious bias from exponential law. This paper studied three typical cases of the decay, by transforming ISI series of the firing to discrete binary chain and calculating the probabilities or frequencies of symbols over the whole chain. The first case is the exponential decay without bias. An example of this case was discovered on hippocampal CA1 pyramidal neuron stimulated by external signal. Probability calculation shows that this decay without bias results from a stochastic renewal process, in which the successive spikes are independent. The second case is the exponential decay with a higher first peak, while the third case is that with a lower first peak. An example of the second case was discovered in experiment on a neural pacemaker. Simulation and calculation of the second and third cases indicate that the dependency in successive spikes of the firing leads to the bias seen in decay of ISIH peaks. The quantitative expression of the decay slope of three cases of firing patterns, as well as the excitatory effect in the second case of firing pattern and the inhibitory effect in the third case of firing pattern are identified. The results clearly reveal the mechanism of the exponential decay in ISIH peaks of a number of important neural firing patterns and provide new understanding for typical bias from the exponential decay law.  相似文献   

9.
探讨应用电子阴道镜在寻找妊娠期阴道出血原因方面的价值。方法:对我院2004年5月-2006年11月64例非产科原因孕期阴道流血的孕妇,进行电子阴道镜检查及颈管分泌物培养和镜下定位活检。结果:阴道镜下发现宫颈赘生物12例,其中2例坏死,10例明显充血水肿;宫颈炎伴活动性出血2例,宫颈炎无活动性出血18例;正常宫颈16例;宫颈上皮内瘤样病变图象15例;宫颈分泌物培养阳性23例。结论:妊娠期不规则阴道出血原因复杂,阴道镜检查能较快排除与查明宫颈及阴道病变所导致的出血。  相似文献   

10.
11.
G. P. Frets 《Genetica》1929,11(5):451-452
Resumé Ichthyosis generalis: a case of sex-limited inheritance in man with recessiveness of the anomaly. The case can be understood from the pedigree.  相似文献   

12.
The case study examines an issue of public health ethics and obesity. How should healthy diets be developed? Can schools associate themselves with commercial fastfood companies? What are the ethical issues related to diet campaigns in an Asia context. The case study elicits several responses from different perspectives. The case study invites readers to think of different cultural contexts and broad issues.  相似文献   

13.
Microfilariae of Wuchereria bancrofti were observed in fine needle aspiration smears from three epididymal nodules, and degenerating microfilariae suggestive of Brugia malayi were found in the smears from a fourth case. The smears in all four cases showed a polymorphonuclear inflammatory cell component as well as epithelioid cell granulomata. While blood eosinophilia was present in all four cases, eosinophilia was present in the aspiration smears in only one case. Microfilariae could be demonstrated in the peripheral blood in only one case.  相似文献   

14.
After stereospecific oxidation, trimethylsilylated methyl esters of mono- and diunsaturated fatty acids were analyzed by combined gas-liquid chromatography-chemical ionization mass spectrometry. The positions of original double bonds were deduced from the fragment ions produced by the cleavage of the carbon-carbon bond between two trimethylsilyl ethers. These fragment ions were recorded at m/e 187 and 259 in the case of 16:1(n-7), at m/e 187 and 287 in the case of 18:1(n-7), at m/e 215 and 259 in the case of 18:1(n-9), and at m/e 172 and 259 in the case of 18:2(n-6), respectively. The diastereoisomers of monounsaturated fatty acids can be discriminated by comparing the intensities of the fragment ions at m/e 253 and 285 in the case of 16:1 and at m/e 281 and 313 in the case of 18:1. The diastereosiomers of diunsaturated fatty acids may also be distinguished from each other by comparing the intensities of the fragment ions formed by the loss of trimethylsilyl function from the characteristic ions. Mono- and diunsaturated fatty acids in liver may be dominantly in cis- 18:1(n-1) and cis-cis-18:2(n-6) as determined by a mass chromatographic technique.  相似文献   

15.
Summary A case of trisomy 9p originating from t(9/22)mat is reported. The rearrangement is characterized by centric fission of chromosome 9 and by translocation of NOR from chromosome 22 to 9q. The hypothesis of centric fission is discussed on the basis of various banding patterns. The case also reveals unusual knee dislocation.  相似文献   

16.
The case of industrial melanism in the peppered moth has been used as a teaching example of Darwinian natural selection in action for half a century. However, over the last decade, this case has come under attack from those who oppose Darwinian evolution. Here, the main elements of the case are outlined and the reasons that the peppered moth case became the most cited example of Darwinian evolution in action are described. Four categories of criticism of the case are then evaluated. Criticisms of experimental work in the 1950s that centered on lack of knowledge of the behavior and ecology of the moth, poor experimental procedure, or artificiality in experiments have been addressed in subsequent work. Some criticisms of the work are shown to be the result of lack of understanding of evolutionary genetics and ecological entomology on the part of the critics. Accusations of data fudging and scientific fraud in the case are found to be vacuous. The conclusion from this analysis of criticisms of the case is that industrial melanism in the peppered moth is still one of the clearest and most easily understood examples of Darwinian evolution in action and that it should be taught as such in biology classes.  相似文献   

17.
Summary The above is a record of a very mild case of psittacosis infection, recognised as such only by means of epidemiological considerations, simplified by developments as these occurred before our eyes. The results of laboratory tests on material obtained from the birds and from a human case, are recorded. The possibilities of infection by apparently healthy birds are discussed.  相似文献   

18.
结合激光雷达分析上海地区一次连续浮尘天气过程   总被引:4,自引:0,他引:4  
马井会  顾松强  陈敏  施红  张国琏 《生态学报》2012,32(4):1085-1096
通过分析2010年3月至20日至3月22日上海地区一次典型的连续浮尘天气过程,利用激光雷达数据资料反演得到的气溶胶消光系数图和垂直廓线图,结合地面气象数据和气溶胶观测资料以及卫星遥感资料,初步得出了此次连续浮尘天气形成的原因。外源性输入和垂直风场分布是导致此次浮尘天气发生的重要原因,大气层结变化决定着浮尘天气发生的强度,当存在接地逆温时,浮尘天气维持,而太阳辐射强度变化决定着边界层高度的变化。第一次浮尘过程以大颗粒污染为主,且在消光作用中散射性气溶胶的贡献大于吸收性气溶胶,而第二次回流浮尘过程则PM2.5比重上升,吸收性气溶胶对消光系数的贡献与散射性气溶胶大体相当。  相似文献   

19.
为了对2005~2006年湖南省2例不明原因肺炎病例进行实验室诊断,确定病因以及对其进行病原学研究,采集病例呼吸道标本和血清标本,对呼吸道标本采用实时荧光定量逆转录聚合酶链式反应(Real-time RT-PCR)和逆转录聚合酶链式反应(RT-PCR)方法检测H5亚型禽流感病毒核酸,对血清标本采用血凝抑制试验检测特异性抗体,并对其中1例死亡病例(病例2)的肺穿刺物标本进行病毒分离,所获毒株予以测序及同源性分析。结果显示,2例病例H5亚型禽流感病毒核酸检测均为阳性,病例1恢复期血清H5N1特异性抗体阳性,并且较急性期血清呈4倍以上增长;病例2急性期血清特异性抗体阴性,2例均为人感染高致病性禽流感病毒(H5N1)确诊病例。从病例2分离得到毒株A/Hunan/1/2006,测序及分子特性分析表明,其8个基因片段均为禽源,且与湖南本地禽类分离的病毒相似,并未与人流感病毒发生基因重组或产生显著变异。  相似文献   

20.
本文以山东地区6处考古遗址出土的18例古代居民的骨化甲状软骨为研究材料,结合现代医学和法医学的研究,通过对甲状软骨骨化情况的观察分析以及部分数据测量,发现古代居民中骨化甲状软骨多保存骨板下缘、下结节以及上下角,而且骨化甲状软骨对古代居民性别和年龄的判断有一定指示作用。甲状软骨在骨化程度、进展速度以及骨化机制上存在性别差异,古代居民中男性比女性更容易保存骨化甲状软骨,且男性多见保存联合部中下段,女性并无个体保存联合部。另外在本文的骨化甲状软骨的两项测量数据上,男性明显大于女性。甲状软骨的骨化个体间差异很大,单独使用甲状软骨骨化规律进行年龄判断并不可取,但可作为一种参考依据来辅助判断。值得注意的是,保存有骨化甲状软骨且年龄明确的古代居民皆大于30岁。  相似文献   

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