全文获取类型
收费全文 | 3333篇 |
免费 | 232篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 158篇 |
妇产科学 | 47篇 |
基础医学 | 403篇 |
口腔科学 | 49篇 |
临床医学 | 248篇 |
内科学 | 586篇 |
皮肤病学 | 90篇 |
神经病学 | 191篇 |
特种医学 | 205篇 |
外国民族医学 | 1篇 |
外科学 | 528篇 |
综合类 | 242篇 |
一般理论 | 1篇 |
预防医学 | 265篇 |
眼科学 | 71篇 |
药学 | 218篇 |
中国医学 | 76篇 |
肿瘤学 | 188篇 |
出版年
2022年 | 17篇 |
2021年 | 51篇 |
2020年 | 44篇 |
2019年 | 36篇 |
2018年 | 50篇 |
2017年 | 68篇 |
2016年 | 56篇 |
2015年 | 58篇 |
2014年 | 112篇 |
2013年 | 154篇 |
2012年 | 208篇 |
2011年 | 241篇 |
2010年 | 163篇 |
2009年 | 166篇 |
2008年 | 205篇 |
2007年 | 198篇 |
2006年 | 148篇 |
2005年 | 121篇 |
2004年 | 117篇 |
2003年 | 106篇 |
2002年 | 131篇 |
2001年 | 101篇 |
2000年 | 73篇 |
1999年 | 69篇 |
1998年 | 52篇 |
1997年 | 38篇 |
1996年 | 51篇 |
1995年 | 35篇 |
1994年 | 29篇 |
1993年 | 26篇 |
1992年 | 32篇 |
1991年 | 34篇 |
1990年 | 33篇 |
1989年 | 31篇 |
1988年 | 33篇 |
1987年 | 36篇 |
1986年 | 38篇 |
1985年 | 38篇 |
1984年 | 30篇 |
1983年 | 25篇 |
1979年 | 16篇 |
1978年 | 19篇 |
1975年 | 20篇 |
1974年 | 22篇 |
1973年 | 21篇 |
1972年 | 20篇 |
1971年 | 23篇 |
1970年 | 16篇 |
1968年 | 24篇 |
1966年 | 16篇 |
排序方式: 共有3609条查询结果,搜索用时 19 毫秒
21.
Zusammenfassung Bei der Auswertung der Blutsenkungen von 807 15–59jährigen ambulanten Patienten (ausgenommen Fälle von entzündlichen oder malignen Erkrankungen oder mit Anämien) ließ sich neben der bekannten Abhängigkeit der Blutsenkung von Geschlecht und Lebensalter nachweisen, daß bei Frauen eine gleichsinnige Korrelation zwischen Körfettgehalt und BSR besteht. Diese Beziehung gilt nicht nur für den klinischen Begriff der Fettsucht (erhöhte BSR), sondern schließt den Bereich der Untergewichtigkeit (erniedrigte BSR) ein.Herrn Prof. Dr. med. et phil.Benno Dukor, Basel, zu seinem 65. Geburtstage gewidmet. 相似文献
22.
Thies A Schachner M Berger J Moll I Schulze HJ Brunner G Schumacher U 《The Journal of pathology》2004,203(4):933-939
Aberrant glycosylation is a common feature of metastatic sub-clones of malignant tumours and in uveal melanoma in particular, the HNK-1 glycotope has been positively correlated with poor prognosis. So far, no such correlation has been investigated in cutaneous melanoma. In order to do so, HNK-1 expression was evaluated immunohistochemically in 100 primary cutaneous melanomas and correlated with metastasis after up to 10-years' follow-up. Furthermore, HNK-1 expression was analysed in metastatic deposits (19 distant cutaneous metastases and six sentinel lymph node metastases), as well as in benign nevi. Kaplan-Meier analysis revealed a positive association between HNK-1 expression and metastasis (p < 0.005) and multivariate Cox regression analysis adjusted for the standard prognostic markers ulceration and vertical tumour thickness confirmed HNK-1 expression as an independent prognostic marker. HNK-1 expression was preserved in 42% of the distant cutaneous metastases, but metastatic cells in lymph nodes were devoid of HNK-1 immunoreactivity. None of the benign pigmented lesions exhibited HNK-1 immunoreactivity. Expression of the HNK-1 glycotope in cutaneous malignant melanoma is an independent prognostic marker of metastasis. Differential HNK-1 expression at the metastatic sites implies that its expression is modulated by the surrounding environment. As HNK-1 is also transiently expressed during migration of melanocyte precursor cells derived from the neural crest, recapitulation of this transient expression might occur during metastatic spread of cutaneous malignant melanoma. 相似文献
23.
Synaptophysin expression in neuroendocrine neoplasms as determined by immunocytochemistry. 总被引:6,自引:3,他引:6
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
V. E. Gould B. Wiedenmann I. Lee K. Schwechheimer B. Dockhorn-Dworniczak J. A. Radosevich R. Moll W. W. Franke 《The American journal of pathology》1987,126(2):243-257
Synaptophysin is an integral membrane glycoprotein originally isolated from presynaptic vesicles of bovine neurons. The authors have studied a wide spectrum of neuroendocrine (NE) neoplasms by immunofluorescence microscopy on cryostat sections of freshly frozen tissues using a monoclonal antibody to this protein (SY 38). Without exception, they found the identical--or a very similar--protein expressed in all neuroblastomas, ganglioneuroblastomas, ganglioneuromas, pheochromocytomas, and paragangliomas studied. In these "neural" type NE neoplasms, synaptophysin was coexpressed with neurofilament proteins. Synaptophysin was also demonstrated in NE neoplasms of "epithelial" type in which it was predominantly coexpressed with cytokeratins and desmoplakin. It was invariably found in all variants of islet cell neoplasms and in all medullary thyroid carcinomas. Synaptophysin was also demonstrated in several adenomas of the hypophysis and parathyroids, in the majority of carcinoids of the bronchopulmonary and gastrointestinal tracts, and in many, though not all, NE carcinomas of the same sites, and of the skin. Conversely, SY 38 did not immunostain any of a large number of benign and malignant non-NE epithelial neoplasms; nor was any immunostaining obtained in a group of mesenchymal tumors. It is remarkable that SY 38 did not immunostain a number of malignant melanomas, including several that were immunostained for neuron-specific enolase (NSE) and several neuropeptides. Parallel studies conducted on conventionally fixed, paraffin-embedded tissue sections immunostained by the use of the avidin-biotin complex technique yielded very similar results. The findings indicate that synaptophysin is expressed in the whole range of NE neoplasms without detectable relation to the expression of other NE markers such as NSE, serotonin, and neuropeptides. Nor could the expression of synaptophysin by these tumors be correlated with their epithelial and/or neural cytoskeletal characteristics, their clinical aggressiveness, or the presence or absence of endocrinologic abnormalities. While the consistent expression of synaptophysin by the "neural" type of NE neoplasms would seem predictable its presence in diverse benign and malignant NE tumors of "epithelial" type is remarkable. It is concluded that synaptophysin is a significant as well as novel NE marker, and the use of antibody SY 38 as a broad range marker for the study and diagnosis of NE neoplasms is proposed. 相似文献
24.
Neulen J; Raczek S; Pogorzelski M; Grunwald K; Yeo TK; Dvorak HF; Weich HA; Breckwoldt M 《Molecular human reproduction》1998,4(3):203-206
Vascularization is a prominent event during corpus luteum formation,
providing low density lipoproteins for steroid biosynthesis and enabling
transport of secreted steroids. The process of vascularization is
controlled by specific regulators. Vascular endothelial growth factor
(VEGF), otherwise named vascular permeability factor (VPF), induces
endothelial cell proliferation as well as angiogenesis in vivo and
increases capillary permeability. Here we report the expression of VEGF/VPF
mRNA by cultured human luteinized granulosa cells (GC) for at least 10
days. Without HCG VEGF/VPF expression declined after day 4 and by day 10
was reduced to approximately 30% of the value at day 4. However, after
culture in the presence of 1 U/ml human chorionic gonadotrophin (HCG),
expression of VEGF/VPF mRNA by GC was four times greater than control
experiments by day 10, and increased 100% from day 4 to day 10.
Simultaneously, HCG supplementation increased VEGF/VPF secretion by GC.
Medium VEGF/VPF on day 3 was 13 pM without and 11 pM with HCG. Medium
VEGF/VPF on day 10 was 6 pM without HCG and 29 pM with HCG. These results
suggest that vascularization of the corpus luteum is induced by
HCG-mediated effects of VEGF/VPF.
相似文献
25.
Heidrun Moll Harald Fuchs Christine Blank Martin Rllinghoff 《European journal of immunology》1993,23(7):1595-1601
Murine epidermal Langerhans cells (LC) have been shown to internalize Leishmania major, a cause of human cutaneous leishmaniasis, and to stimulate a vigorous parasite-specific T cell response. The present study emphasizes the critical role of LC in leishmaniasis by documenting directly that LC have the ability to transport L. major from the skin to the draining lymph node (LN). This was revealed by irreversible labeling of LC with a fluorescent cell linker and in vivo tracking. In contrast, no migration to the LN was seen with L. major-infected macrophages. These findings were consistent with the results of mixed labeling immunohistology showing that early in infection the expression of parasite antigen in the LN draining the lesion was confined to dendritic cells and could not be detected in macrophages. Furthermore, dendritic cells in LN draining the site of cutaneous infection stimulated L. mayor-primed T cells in vitro and, most notably, were able to activate unprimed T cells capable of mediating parasite-specific delayed-type hypersensitivity reactivity in vivo. Taken together, the results indicate that LC capture L. major in the skin and transport it to the regional LN for initiation of the specific T cell immune response. 相似文献
26.
Fever and antipyresis in the lizard Dipsosaurus dorsalis 总被引:2,自引:0,他引:2
27.
CD34(+) fibrocytes in normal cervical stroma,cervical intraepithelial neoplasia III,and invasive squamous cell carcinoma of the cervix uteri 总被引:3,自引:0,他引:3
Barth PJ Ramaswamy A Moll R 《Virchows Archiv : an international journal of pathology》2002,441(6):564-568
CD34(+) fibrocytes are widely distributed in normal connective tissues but have been reported to be absent within the stroma associated with invasive carcinomas. In the present study we investigated the presence and distribution of CD34(+) fibrocytes and alpha-smooth muscle actin (alpha-SMA) positive myofibroblasts in cervical intraepithelial neoplasia III (CIN III; n=8), invasive carcinoma of the cervix ( n=18) and adjacent normal cervical stroma. Normal cervical stroma and the stroma adjacent to CIN III disclosed a dense network of CD34(+) fibrocytes, whereas the stroma of invasive carcinoma was virtually free of this cell population. Early stromal invasion by squamous carcinoma was characterized by a focal loss of CD34(+) fibrocytes. alpha-SMA-positive myofibroblasts were not seen in the normal cervical stroma but occurred in six of eight cases of CIN III adjacent to the atypical epithelium. The stroma of invasive carcinoma was made up of large amounts of haphazardly arranged alpha-SMA-positive myofibroblasts. In the setting of the present study, a loss of CD34(+) fibrocytes was specific for stromal alterations associated with invasive carcinoma and proved to be a sensitive tool in detecting small foci of stromal invasion. Therefore, detection of a loss of CD34(+) fibrocytes may constitute an adjunctive tool in detecting (1) early stromal invasion and (2) invasive carcinoma in small biopsy specimens. Moreover, the present study shows that CD34(+) fibrocytes and myofibroblasts play an important role in stromal remodeling associated with invasive squamous cell carcinoma of the cervix. 相似文献
28.
V E Gould R Moll I Moll I Lee K Schwechheimer W W Franke 《Laboratory investigation; a journal of technical methods and pathology》1986,55(4):463-474
The intermediate filament complement of the spectrum of nerve sheath neoplasms including 12 typical benign schwannomas, 1 ancient schwannoma, 2 cellular schwannomas, 6 neurofibromas and 4 malignant schwannomas was investigated by immunofluorescence microscopy, two dimensional electrophoresis, and immunoblot analysis. Studies were performed on freshly frozen tumor tissue samples; a broad spectrum of antibodies against all classes of intermediate filaments was utilized. Samples were also studied by electron microscopy, and immunohistochemically for S-100 protein and desmoplakins. By immunofluorescence microscopy, all nerve sheath neoplasms revealed intense positivity for vimentin throughout the cytoplasm while 2 benign schwannomas displayed co-expression of vimentin and glial filament proteins. Two-dimensional gel electrophoresis and immunoblot analysis confirmed the presence of vimentin and showed that it was the predominant protein in all tumors. Electrophoretic analysis of the 2 benign schwannomas that immunostained for glial filament proteins confirmed the presence of this protein which was shown to comigrate with a known human control sample. Neither immunofluorescence microscopy nor biochemical analyses revealed cytokeratin polypeptides, neurofilament proteins, desmin, or desmoplakin in any of the tumors. We conclude that while vimentin is the predominant intermediate filament expressed by the entire spectrum of nerve sheath neoplasms, at least occasional benign schwannomas are capable of co-expressing glial filament proteins. It remains to be determined whether the subgroup of nerve sheath neoplasms that co-expresses vimentin and glial filament proteins is otherwise distinguishable from their more frequent counterparts that express vimentin exclusively. 相似文献
29.
V. E. Gould K. J. Bloom W. W. Franke W. H. Warren R. Moll 《Virchows Archiv : an international journal of pathology》1995,425(6):617-629
A total of 291 enlarged lymph nodes showing a range of reactive-inflammatory processes, primary and metastatic neoplasms were studied to determine the distribution and immunoprofile of their cytokeratin-positive interstitial reticulum cells (CIRC) in comparison with normal nodes. In 258/291 nodes (89%), CIRC numbers were distinctly increased in the subcapsular, paracortical and, occasionally, in the medullary zones; often, these increased CIRC formed networks around follicles, sinuses and vessels. CIRC had comparatively small, irregularly shaped bodies and dendritic processes; occasionally, giant forms were noted. CIRC contained cytokeratins (CK) 8 and 18 but not 19, as shown by immunohistochemistry, and by gel electrophoresis with subsequent immunoblotting. They co-expressed vimentin consistently, alpha-smooth-muscle actin frequently, and desmin less frequently. They did not contain desmoplakins, Factor VIII, S-100, LCA, B and T lymphocyte- and macrophage-associated antigens, chromogranin A, synaptophysin or the A-80 glycoprotein. We found no clear correlation between the increased CIRC and given nodal disease processes. However, CIRC were most abundant in nodes free of but draining malignant tumours; bizarre CIRC assemblies were noted in HIV lymphadenopathy. CIRC appear to represent a subset of the so-called fibroblastic reticulum cells of lymph nodes. Their function remains undetermined; their increase in diverse lymphadenopathies suggests that they partake in nodal reactions to injury. It remains unclear whether the increase in CIRC relative number is due to proliferation or to CK gene induction processes but their presence and potential capability to undergo hyperplasia with dysplastic forms should alert pathologists to possible diagnostic pitfalls. In addition, we discuss that CIRC may undergo transformation and represent the cell of origin of certain CK-positive tumours restricted to lymph nodes. 相似文献
30.
Summary The CO2 diffusion constant (Krogh's diffusion constant) has been estimated from the CO2 flux across layers with defined thickness under steady state conditions.At 22°C and in hemoglobin solutions with a concentration of 33 g% the diffusion constant for CO2 was found to be 3.3×10–4 cm2 min–1 atm–1. This value is about 40% of the diffusion constant for CO2 in water. The relationship between the diffusion constant and the hemoglobin concentration was approximately linear in a concentration range of 10–40 g%. The temperature coefficient of the diffusion constant was –0.5%/°C both in water and hemoglobin solutions. At 38°C and in a hemoglobin solution with a concentration of 33 g%, the diffusion constant for CO2 was therefore 3.0×10–4 cm2 min–1 atm–1, the diffusion coefficient 11×10–6 cm2 s–1.A general theory for the diffusion of CO2 in hemoglobin solutions has been derived. According to this theory the diminution of the CO2 diffusion in hemoglobin solutions in comparison to water can be explained quantitatively by a reduction of the water space by the hemoglobin molecules.The diffusion constant for CO2 in layers of erythrocytes was insignificantly (0–3%) smaller than in hemoglobin solutions with the same hemoglobin concentration. It is concluded that the erythrocyte membrane does not offer a considerable resistance for the CO2 diffusion. 相似文献