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51.
The value of fine catheter aspiration cytology in the diagnosis of metastatic tumours is illustrated by a case of pleomorphic giant cell carcinoma of the pancreas which had metastasized to the peritoneal cavity. The finding of unequivocal malignant cells obviated the need for further diagnostic procedures. Electron microscopy and immunostaining further substantiated the light microscopic cytodiagnosis and identified the tumour type and source of the primary tumour. Furthermore, subsequent cell block preparation from the aspirated material demonstrated the histological features of this tumour. 相似文献
52.
J. P. Dudley G. C. Criag † D. ST. C. Gibson G. Haynes J. Klimowicz 《African Journal of Ecology》2001,39(2):187-194
African bush elephants inhabiting the undeveloped Kalahari Sands region of Hwange National Park, Zimbabwe are subject to episodic mortality during droughts. We monitored the drought‐related mortality of elephants in Hwange National Park over the course of an extended drought between 1993 and 1995. The drought‐related mortality of elephants was higher during 1994 than 1995, despite significantly higher rainfall in 1994 than 1995. We found significant differences in the age‐specific mortality of elephants during 1994 and 1995. The cumulative mortality profile from this study differed significantly from previous die‐offs at this site, with a higher mortality among adult age classes than that reported from earlier studies in Hwange National Park. The effective duration of the rainy season, not total annual precipitation, appears to be the best predictor for the potential severity of drought mortality among elephants in the Kalahari Sands habitats of Hwange National Park. 相似文献
53.
Background
The polarization of somite-derived sclerotomes into anterior and posterior halves underlies vertebral morphogenesis and spinal nerve segmentation. To characterize the full extent of molecular differences that underlie this polarity, we have undertaken a systematic comparison of gene expression between the two sclerotome halves in the mouse embryo. 相似文献54.
55.
The genus Pseudostegania Butler is revised. In addition to the two species known, four species are described as new: P. lijiangensis sp. nov. from Yunnan Province, P. qinlingensis sp. nov. from Gansu and Shaanxi Provinces, P. zhoui sp. nov. from Sichuan Province (China) and P. burmaensis sp. nov. from Burma (Myanmar); two species are newly combined with Pseudostegania: P. distinctaria (Leech, 1897), comb. nov. and P. yargongaria (Oberthür, 1916), comb. nov. All the known species are redescribed and lectotypes are designated for P. defectata (Christoph, 1881), P. distinctaria and P. yargongaria. The generic characters, based on all species, are summarized. The tribal placement of Pseudostegania is discussed. Illustrations of moths and genitalia are presented. 相似文献
56.
57.
DAVID STÅHLBERG MIKAEL HEDRÉN 《Biological journal of the Linnean Society. Linnean Society of London》2010,101(3):503-525
Taxonomic complexity may be associated with migration history and polyploidy. We used plastid and nuclear DNA markers to investigate the evolutionary history of the systematically challenging Dactylorhiza maculata polyploid complex. A total of 1833 individuals from 298 populations from throughout Europe were analysed. We found that gene flow was limited between the two major taxa, diploid ssp. fuchsii (including ssp. saccifera) and tetraploid ssp. maculata. A minimum of three autotetraploid lineages were discerned: (1) southern/western ssp. maculata; (2) northern/eastern ssp. maculata; and (3) Central European ssp. fuchsii. The two ssp. maculata lineages, which probably pre‐date the last glaciation, form a contact zone with high genetic diversity in central Scandinavia. Intermediate plastid haplotypes in the contact zone hint at recombination. Central Europe may have been a source area for the postglacial migration for the southern/western lineage of ssp. maculata, as well as for ssp. fuchsii. The northern/eastern lineage of ssp. maculata may have survived the LGM in central Russia west of the Urals. The tetraploid lineage of ssp. fuchsii is indistinguishable from diploid ssp. fuchsii, and is probably of postglacial origin. The Mediterranean region and the Caucasus have not contributed to the northward migration of either ssp. fuchsii or ssp. maculata. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 503–525. 相似文献
58.
The phenology of spring migration depends on the severity of the preceding winter and approaching spring. This severity can be quantified using the North Atlantic Oscillation (NAO) index; positive values indicate mild winters. Although milder winters are correlated with earlier migration in many birds in temperate regions, few studies have addressed how climate‐induced variation in spring arrival relates to breeding success. In northern Europe, the NAO‐index correlates with ice cover and timing of ice break‐up of the Baltic Sea. Ice cover plays an important role for breeding waterfowl, since the timing of ice break‐up constrains both spring arrival and onset of breeding. We studied the effects of the winter‐NAO‐index and timing of ice break‐up on spring migration, laying date, clutch size, female body condition at hatching and fledging success of a short‐distance migrant common eider (Somateria mollissima) population from SW Finland, the Baltic Sea, 1991–2004 (migration data 1979–2004). We also examined the correlation between the NAO‐index and the proportion of juvenile eiders in the Danish hunting bag, which reflects the breeding success on a larger spatial scale. The body condition of breeding females and proportion of juveniles in the hunting bag showed significant positive correlations with the NAO, whereas arrival dates showed positive correlations and clutch size and fledging success showed negative correlations with the timing of ice break‐up. The results suggest that climate, which also affects ice conditions, has an important effect on the fledging success of eiders. Outbreaks of duckling disease epidemics may be the primary mechanism underlying this effect. Eider females are in poorer condition after severe winters and cannot allocate as much resources to breeding, which may impair the immune defense of ducklings. Global climate warming is expected to increase the future breeding success of eiders in our study population. 相似文献
59.
This study examined the application of previously characterized microparticles composed of hyaluronan (HA) and chitosan hydroglutamate (CH) as well as novel microparticles consisting of both polymers (HA/CH) to improve the nasal delivery of a model drug. The rabbit bioavailabilities of gentamicin incorporated in HA, CH, and HA/CH microparticles were increased 23-, 31-, and 42-fold, respectively, compared with the control intranasal solution of gentamicin, indicating that all test microparticles were retained for longer periods on the nasal mucosa of the rabbits as supported by previous in vitro dissolution as well as frog palate mucoadhesion studies, thereby improving drug absorption. The higher bioavailabilities of CH-based formulations (CH and HA/CH) suggest the penetration-enhancing effects of CH may also be partially responsible for the improvement. A model was developed, based on a glass impinger device, to deliver dry powder formulations reproducibly onto the surface of cultured cell monolayers. In vitro permeability and fluorescence microscopy studies on the tight junctions of the 16HBE14o- cell lines further confirmed the ability of CH-based formulations to enhance penetration. Furthermore, the in vitro absorption profile from cell culture studies was consistent with those determined from in vivo studies. The complementary effect from the mucoadhesive nature of HA coupled with the penetration-enhancing effects of CH makes the novel HA/CH formulation a promising nasal delivery system. 相似文献
60.
R. LÜHKEN C. CZAJKA S. STEINKE H. JÖST J. SCHMIDT‐CHANASIT W. PFITZNER N. BECKER E. KIEL A. KRÜGER E. TANNICH 《Medical and veterinary entomology》2016,30(2):144-154
Owing to their role as vectors of malaria parasites, species of the Anopheles maculipennis complex (Diptera: Culicidae) Meigen were intensively studied in the past, but with the disappearance of malaria in Germany in the middle of the last century, the interest in this field of research declined. A comprehensive ecological analysis of the current species distribution for Germany is lacking. Between 2010 and 2013, a total of 1445 mosquitoes of the An. maculipennis complex were collected at 72 different sites in Germany. The samples comprise 722 single individuals as well as 723 individuals in 90 pools of up to 25 mosquitoes. All samples were analysed with newly developed species‐specific qPCR assays for the identification of the four German species using nucleotide differences within the internal transcribed spacer 2 (ITS2) ribosomal DNA. All gathered data were used for species distribution modelling. The overall prevalence of An. messeae s.l. was highest with 98.89% of all pools; An. daciae with 6.93% of all individuals and An. messeae s.s. with 69.53%. The prevalence of the other two species was relatively low: An. maculipennis s.s. with 13.30% of all individuals (6.67% of all pools) and An. atroparvus with 1.80% of all individuals (1.11% of all pools). 相似文献