首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   17篇
  免费   2篇
  2021年   1篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2015年   1篇
  2014年   1篇
  2013年   4篇
  2010年   1篇
  2001年   1篇
  1997年   2篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1983年   1篇
排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
Impression cytology is a simple and painless procedure that allows the collection of the superficial layers of the conjunctival epithelium. Each sample is assigned a grade of epithelial metaplasia, and goblet cell density is calculated in each one. We have studied the superior and temporal bulbar conjuctiva of dry eyes and have compared it with that of normal controls. In normal and dry eyes we find a statistically significant difference both in goblet cell density and grade of metaplasia, between superior and temporal bulbar conjunctiva. the differences in grade of metaplasia and goblet cell density between normal and dry eyes are significant in the superior conjunctiva, but in the temporal conjunctiva we only find significant differences in grade of metaplasia.  相似文献   
2.
We describe a new specimen of a supposed Paleozoic tetrapod body impression from the Lower Permian S?upiec Formation in the Intra-Sudetic Basin, Poland. The size, integument morphology of belly and part of tail imprints, and the morphology of a well-preserved pes track diagnose the specimen and readily distinguish it from other described specimens of body impressions of Paleozoic tetrapods. The eupelycosaur identity of this new specimen is based on the identification of the footprint Dimetropus leisnerianus (Geinitz, 1863 Geinitz, H. B. 1863. Beiträge zur Kenntnis der organischen Überreste in der Dyas (oder permischen Formation zum Theil) und über den Namen Dyas. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, : 385398.  [Google Scholar]), which is connected with the inferred body imprint. The morphology of integument impressions indicates the presence of the various-sized square or rectangular-shaped scales on the bottom part of the belly and tail of this eupelycosaurid trackmaker.  相似文献   
3.
Since 1858, when Hitchcock first recorded dinosaur tail traces from the Jurassic of Massachusetts, USA, a number of dinosaur tail traces have been reported. Although considered rare, at least 38 records of dinosaur tail traces have previously been reported in the literature. These occurrences are herein reviewed in order to understand their geographic and stratigraphic distribution, types of tail trace makers, and characteristics of dinosaur tail traces. Several terms for dinosaur tail traces have been employed and they are divided into tail impressions (TIs) for resting traces, and tail drag impressions (TDIs) for locomotion traces. Possible criteria for distinguishing, measuring and comparing TIs and TDIs are suggested. In addition, herringbone structures, one of the characteristic features of tail traces associated with ornithopod and theropod tracks, are discussed. Estimated speeds of tail trace makers are shown to be rather low. Finally, the abundance of tail traces associated with bipedal, rather than quadrupedal, dinosaurs is considered a reflection of behavior.  相似文献   
4.
《Anthrozo?s》2013,26(3):225-243
Abstract

This work found that participants attributed traits associated with breeds of dogs to their owners (indicating that a person may be perceived as more nervous if believed to own a Chihuahua, more heroic if believed to own a Collie, more aggressive if believed to own a Doberman, etc.). The findings further suggest that some people have folk theories that owners select breeds of dogs that resemble them dispositionally. When participants were unable to use this folk theory (when it was clear that the target people were not the dogs' owners and just randomly happened to share the same environment) those participants who owned dogs themselves still transferred traits; however those who did not own dogs themselves did not do so. These findings provide evidence of a novel associative effect in person impression and are discussed in terms of simple associative versus inferential processes.  相似文献   
5.
Coprolites (fossilized feces) can preserve a wide range of biogenic components. A mold of a hatchling turtle partial shell (carapace) referable to Taphrosphys sulcatus is here identified within a coprolite from Clapp Creek in Kingstree, Williamsburg County, South Carolina, USA. The specimen is the first-known coprolite to preserve a vertebrate body impression. The small size of the turtle shell coupled with the fact that it shows signs of breakage indicates that the turtle was ingested and that the impression was made while the feces were still within the body of the predator. The detailed impression could only have survived the act of defecation if the section of bony carapace was voided concurrently and remained bonded with the feces until the latter lithified. Exceptionally, the surface texture of the scutes is preserved, including its finely pitted embryonic texture and a narrow perimeter of hatchling scute texture. The very small size of the shell represented by the impression makes it a suitable size for swallowing by any one of several large predators known from this locality. The coprolite was collected from a lag deposit containing a temporally mixed vertebrate assemblage (Cretaceous, Paleocene and Plio-Pleistocene). The genus Taphrosphys is known from both sides of the Cretaceous–Paleogene (K–Pg) boundary so, based on the size of the coprolite and the locally-known predators, the juvenile turtle could have been ingested by a mosasaur, a crocodylian, or a theropod dinosaur. Unlike mosasaurs and theropod dinosaurs, crocodylian stomachs have extremely high acid content that almost always dissolves bone. Therefore, the likely predator of this turtle was a mosasaur or a (non-avian or avian) theropod dinosaur.  相似文献   
6.
本文摸索眼结膜印迹细胞法及其影响因素,证明该方法是一项简便,快速,有效地评价机体维生素A营养状况的方法;取样材料,染色时间,温度,透明方法均可影响制片结果。该方法适合基层推广应用。  相似文献   
7.
Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 ± 1.1 µm for trueness and 1.6 ± 0.6 µm for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 ± 2.2 µm, precision: 12.5 ± 2.5 µm) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes.  相似文献   
8.
Diagnostic impression cytology: a simple technique for the diagnosis of external eye disease
The technique of impression cytology was used for cytologic examination of conjunctival samples from 128 patients with a variety of external eye diseases. The method of sample collection and the staining procedure are described. Microscopic examination showed 62 cases with allergic conjunctivitis, 23 with bacterial or viral infection, 26 cases with changes typical of dry eye and 17 cases with non-specific chronic inflammation. The cytologic features and numerous applications of impression cytology are discussed.  相似文献   
9.
Efficacy of a training programme designed to teach cervical smear screeners to identify ocular surface squamous neoplasia using conjunctival impression cytology
Ocular surface squamous neoplasia (OSSN) is a recently proposed term introduced to encompass both intraepithelial neoplasia and invasive squamous cell carcinoma of the conjunctiva and cornea. A teaching programme incorporating a manual, slide sets, and an evaluation test was developed. The aim was to teach experienced cervical smear screeners to evaluate ocular surface specimens collected by conjunctival impression cytology, with a minimum of individual tuition. The use of the manual was well accepted and half of the original six candidates were able to master the new skill adequately within 8 h. It was considered that the differences between the cytology of OSSN and the equivalent lesions of the uterine cervix are sufficient to prevent some experienced screeners acquiring these skills rapidly.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号