全文获取类型
收费全文 | 4657篇 |
免费 | 260篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 117篇 |
妇产科学 | 54篇 |
基础医学 | 925篇 |
口腔科学 | 87篇 |
临床医学 | 333篇 |
内科学 | 874篇 |
皮肤病学 | 85篇 |
神经病学 | 439篇 |
特种医学 | 251篇 |
外科学 | 640篇 |
综合类 | 24篇 |
一般理论 | 1篇 |
预防医学 | 257篇 |
眼科学 | 121篇 |
药学 | 409篇 |
中国医学 | 4篇 |
肿瘤学 | 271篇 |
出版年
2022年 | 24篇 |
2021年 | 70篇 |
2020年 | 35篇 |
2019年 | 52篇 |
2018年 | 75篇 |
2017年 | 60篇 |
2016年 | 67篇 |
2015年 | 92篇 |
2014年 | 115篇 |
2013年 | 133篇 |
2012年 | 255篇 |
2011年 | 244篇 |
2010年 | 145篇 |
2009年 | 137篇 |
2008年 | 209篇 |
2007年 | 250篇 |
2006年 | 233篇 |
2005年 | 255篇 |
2004年 | 258篇 |
2003年 | 266篇 |
2002年 | 248篇 |
2001年 | 100篇 |
2000年 | 76篇 |
1999年 | 79篇 |
1998年 | 82篇 |
1997年 | 57篇 |
1996年 | 49篇 |
1995年 | 51篇 |
1994年 | 41篇 |
1993年 | 46篇 |
1992年 | 62篇 |
1991年 | 47篇 |
1990年 | 57篇 |
1989年 | 58篇 |
1988年 | 44篇 |
1987年 | 36篇 |
1986年 | 56篇 |
1985年 | 45篇 |
1984年 | 44篇 |
1983年 | 27篇 |
1982年 | 37篇 |
1981年 | 31篇 |
1980年 | 41篇 |
1979年 | 45篇 |
1978年 | 22篇 |
1977年 | 31篇 |
1976年 | 35篇 |
1975年 | 24篇 |
1973年 | 32篇 |
1969年 | 22篇 |
排序方式: 共有4925条查询结果,搜索用时 31 毫秒
41.
Rudolf Ernst Lang Karl-Heinz Voigt Horst Lorenz Fehm Ernst Friedrich Pfeiffer 《Neuroscience letters》1976,2(1):19-22
Hypothalamic nuclei were removed from frozen sections of rat brain and examined for their corticotropin-releasing activity. The highest concentration was measured in the median eminence. In addition there was significantly more activity detected in the nuclei paraventricularis, supraopticus, suprachiasmaticus and arcuatus than in the other nuclei. 相似文献
42.
Requirement for tumor necrosis factor receptor 2 expression on vascular cells to induce experimental cerebral malaria
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stoelcker B Hehlgans T Weigl K Bluethmann H Grau GE Männel DN 《Infection and immunity》2002,70(10):5857-5859
Using tumor necrosis factor receptor type 2 (TNFR2)-deficient mice and generating bone marrow chimeras which express TNFR2 on either hematopoietic or nonhematopoietic cells, we demonstrated the requirement for TNFR2 expression on tissue cells to induce lethal cerebral malaria. Thus, TNFR2 on the brain vasculature mediates tumor necrosis factor-induced neurovascular lesions in experimental cerebral malaria. 相似文献
43.
Many biochemical, physiological, and behavioral processes display daily rhythms generated by an internal timekeeping mechanism referred to as the circadian clock. The core oscillator driving this clock is located in the ventral part of the hypothalamus, the so called suprachiasmatic nuclei (SCN). At the molecular level, this oscillator is thought to be composed of interlocking autoregulatory feedback loops involving a set of clock genes. Among the components driving the mammalian circadian clock are the Period 1 and 2 (mPer1 and mPer2) and Cryptochrome 1 and 2 (mCry1 and mCry2) genes. A mutation in the mPer2 gene leads to a gradual loss of circadian rhythmicity in mice kept in constant darkness (DD). Here we show that inactivation of the mCry2 gene in mPer2 mutant mice restores circadian rhythmicity and normal clock gene expression patterns. Thus, mCry2 can act as a nonallelic suppressor of mPer2, which points to direct or indirect interactions of PER2 and CRY2 proteins. In marked contrast, inactivation of mCry1 in mPer2 mutant mice does not restore circadian rhythmicity but instead results in complete behavioral arrhythmicity in DD, indicating different effects of mCry1 and mCry2 in the clock mechanism 相似文献
44.
Interferon-gamma (IFN-gamma) and IL-4 expressed during mercury-induced membranous nephropathy are toxic for cultured podocytes.
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W Coers J T Vos P H Van der Meide M L Van der Horst S Huitema J J Weening 《Clinical and experimental immunology》1995,102(2):297-307
The subepithelial immune deposits of Dorus Zadel Black (DZB) rats with mercury-induced membranous nephropathy consist of autoantibodies directed to laminin P1 and of complement. The animals develop massive proteinuria within 10-14 days which is associated with obliteration of foot processes of glomerular visceral epithelial cells (GVEC), or podocytes. Previous studies indicate that these autoantibodies are probably not the sole mediator of proteinuria and GVEC damage. In this study we investigated whether circulating or macrophage-derived cytokines can contribute to the GVEC changes as detected in vivo. In vivo at the height of the proteinuria, increased intraglomerular IFN-gamma immunoreactivity was found. In diseased rats a five-fold increase in intraglomerular macrophages was found, but we could not detect intraglomerular IFN-alpha, IFN-beta, IL-1 beta or tumour necrosis factor-alpha (TNF-alpha) by using immunohistology. Subsequently, we exposed cultured GVEC to these cytokines to investigate their cytotoxic effects on several physiological and structural parameters. IFN-gamma and IL-4 were the only cytokines that exerted toxic effects, resulting in a rapidly decreased transepithelial resistance of confluent monolayers, which was closely associated with altered immunoreactivity of the tight junction protein ZO-1. IL-4 also affected vimentin and laminin immunoreactivity. IFN-gamma and IL-4 only interfered with monolayer integrity when added to the basolateral side of the GVEC, indicating specific (receptor-mediated) effects. Only IL-4 decreased the viability of the cells, and treated monolayers demonstrated an increased passage of the 44-kD protein horseradish peroxidase. From our experiments we concluded that IFN-gamma subtly affected monolayer integrity at the level of the tight junctions, and that IL-4 additionally induced cell death. We hypothesize that the toxic effects of the cytokines IFN-gamma and IL-4 as seen with cultured podocytes are necessary together with the autoantibodies, for the ultimate induction of proteinuria in mercury nephropathy in the DZB rat. 相似文献
45.
46.
PG-M1: A New Monoclonal Antibody Directed against a Fixative-Resistant Epitope on the Macrophage-Restricted Form of the CD68 Molecule 总被引:9,自引:6,他引:9
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)
Brunangelo Falini Leonardo Flenghi Stefano Pileri Marcello Gambacorta Barbara Bigerna Horst Durkop Florian Eitelbach Juergen Thiele Roberta Pacini Antonio Cavaliere Massimo Martelli Nadia Cardarelli Elena Sabattini Simonetta Poggi Harald Stein 《The American journal of pathology》1993,142(5):1359-1372
A new anti-macrophage monoclonal antibody (PG-M1) was produced by immunizing BALB/c mice with fresh spleen cells from a patient with Gaucher's disease. PG-M1 reacts strongly with a fixative-resistant epitope of an intracytoplasmic molecule, selectively expressed by virtually all macrophages of the human body. Although attempts to immunoprecipitate the molecule recognized by PG-M1 have failed so far, the reactivity of the antibody with COS-1 and WOP cells transfected with a human complementary DNA clone encoding for the CD68 antigen suggests that PG-M1 is a new member of the CD68 cluster. However, unlike other CD68 antibodies (KP1, EBM11, etc.), which react with both macrophages and myeloid cells, PG-M1 detects a fixative-resistant epitope on the macrophage-restricted form of the CD68 antigen. In 957 routinely fixed, paraffin-embedded samples, PG-M1 showed a more restricted reactivity with elements of the monocyte/macrophage lineage than the previously described monoclonal antibodies MAC-387 (anti-calgranulins), KP1 (CD68) and Ki-M1P. Among hematological malignancies, PG-M1 only labels acute leukemias of M4 and M5 type and rare examples of malignant histiocytosis/true histiocytic sarcoma. In contrast, acute leukemias of the M1, M2, M3, M6, M7, and L1-L3 types, non-Hodgkin's lymphomas, and Hodgkin and Reed-Sternberg cells of Hodgkin's disease are consistently PG-M1-negative. In the daily diagnostic practice, PG-M1 seems to be particularly valuable for the diagnosis of myelomonocytic or monocytic leukemia and neoplasms of true histiocytic origin in routine paraffin sections. 相似文献
47.
Zusammenfassung Die vonMacracanthorhynchus hirudinaceus verursachten Läsionen im Dünndarm von experimentell infizierten Hausschweinen (7 Tage p.i. und 84 Tage p.i.) wurden licht- und elektronenmikroskopisch untersucht. Die Würmer der 84 Tage alten Infektion waren tiefer in die Darmwand eingedrungen als die 7 Tage alten Würmer. Ihr Präsoma wurde von Entzündungsbzw. Bindegewebe umhüllt, das zahlreiche Plasmazellen enthielt. Bei 7 Tage alten Infektionen wurde noch keine Fibrose nachgewiesen. Eosinophilen-ähnliche Granulozyten, die an den Proboscishaken akkumulierten, herrschten in der Läsion vor. Eine osmiophile Gleitflüssigkeit, die offenbar an der Basis der Proboscishaken ausgeschieden wurde, schien eine stark antigene Wirkung auf die Leukozyten des Schweins auszuüben. In keinem Fall wurden Würmer angetroffen, die die gesamte Darmwand perforiert hatten, wie es in China bei Menschen beschrieben wurde.
Unterstützt durch ein Stipendium der VR China für Herrn Bin Zhao 相似文献
Light and electron microscopical investigation of the histopathogenicity ofMacracanthorhynchus hirudinaceus in experimentally infected swine
One and 12 weeks after infection the lesions in the small intestine of two domestic pigs caused byMacracanthorhynchus hirudinaceus were studied by means of light and electron microscopy. Worms of 7 d.p.i. were found to have penetrated with their presoma into the tunica propria and partly into the tunica muscularis where they had caused local mechanic destructions and heavy eosinophilic-like and hemorrhagic reactions. Most eosinophilic-like granulocytes were attracted to the proboscis hooks, at the base of which an osmiophilic substance apparently was excreted. Worms of 84 d.p.i. had penetrated with their proboscis deeply into the tunica muscularis. The presoma had become encapsulated by a solid capsule of necrotic/inflammatory tissue in its inner part and by filamentous connective tissue in its outer part. The predominant leucocytes in the inflammatory tissue now were plasma cells indicating a progressive immune reaction. No worms were found to have perforated the entire intestinal wall as was described from human patients in China.
Unterstützt durch ein Stipendium der VR China für Herrn Bin Zhao 相似文献
48.
Lymphatic absorption and metabolism of orally administered testosterone undecanoate in man 总被引:2,自引:0,他引:2
H. -J. Horst W. J. Höltje M. Dennis A. Coert J. Geelen K. D. Voigt 《Journal of molecular medicine (Berlin, Germany)》1976,54(18):875-879
Summary [3H]-testosterone undecanoate ([3H]TU) was administered orally to 4 patients with a thoracic duct catheter after neck dissection surgery.Appearance of radioactivity in lymph, plasma and urine was measured at different times. Metabolites of TU in these fluids were investigated. Peak levels of radioactivity appeared simultaneously in lymph and plasma (2.5–5 h after administration) while the excretion in urine was highest approximately 2 h after the plasma and lymph peak. The main compounds appearing in the lymph were TU and 5-dihydrotestosterone undecanoate (5-DHTU), but 5-DHTU could not be detected. In plasma almost all metabolites were probably conjugated.During the first 24 h approximately 40% of the administered radioactivity was excreted in the urine. The total amount of radioactivity excreted in the urine during the first week was 45–48%. The predominant urinary metabolites were testosterone- and androsterone-glucuronide.The results indicate that TU is metabolized partly in the intestinal wall. The remaining TU and newlyformed 5-DHTU, at least partly, are absorbed via the lymphatic system. 相似文献
49.
Somatoform pain disorder in the general population 总被引:6,自引:0,他引:6
Grabe HJ Meyer C Hapke U Rumpf HJ Freyberger HJ Dilling H John U 《Psychotherapy and psychosomatics》2003,72(2):88-94
BACKGROUND: Chronic pain disorder is assumed to represent a frequent and disabling condition. However, data on the prevalence of somatoform pain symptoms and somatoform pain disorder in the community are limited to date. METHODS: German versions of the Composite International Diagnostic Interview were administered to a representative national sample of 4,075 people. Somatoform pain disorder was diagnosed by standardized diagnostic algorithm based on the DSM-III-R criteria (absence of adequate physical findings). One subgroup was identified as also meeting the DSM-IV criterion B for 'significant distress or psychosocial impairment due to the somatoform pain'. RESULTS: A lifetime prevalence rate of somatoform pain disorder according to DSM-III-R of 33.7% and a 6-month rate of 17.3% was found. When applying the DSM-IV B criterion, the prevalence rate dropped to 12.3 and 5.4%, respectively. In both groups more than 95% of the probands had contacted their doctor because of the pain. In 25% of the probands the pain was positively assigned to psychological factors. A female:male ratio of 2:1 was found. CONCLUSIONS: Somatoform pain disorder (DSM-III-R) is a frequent condition. However, only about one third of these subjects is severely distressed or impaired by the pain. A clear operationalized concept of the DSM-IV criterion C 'psychological factors are judged to have an important role in the onset, severity, exacerbation or maintenance of the pain' should be provided in the further development of the diagnosis 'pain disorder' in order to make this diagnosis suitable for general population surveys. 相似文献
50.