全文获取类型
收费全文 | 6376篇 |
免费 | 380篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 222篇 |
妇产科学 | 61篇 |
基础医学 | 1116篇 |
口腔科学 | 280篇 |
临床医学 | 535篇 |
内科学 | 948篇 |
皮肤病学 | 238篇 |
神经病学 | 729篇 |
特种医学 | 266篇 |
外科学 | 796篇 |
综合类 | 35篇 |
一般理论 | 2篇 |
预防医学 | 247篇 |
眼科学 | 288篇 |
药学 | 465篇 |
中国医学 | 9篇 |
肿瘤学 | 480篇 |
出版年
2023年 | 16篇 |
2022年 | 49篇 |
2021年 | 89篇 |
2020年 | 83篇 |
2019年 | 67篇 |
2018年 | 105篇 |
2017年 | 96篇 |
2016年 | 131篇 |
2015年 | 175篇 |
2014年 | 188篇 |
2013年 | 239篇 |
2012年 | 367篇 |
2011年 | 367篇 |
2010年 | 253篇 |
2009年 | 255篇 |
2008年 | 463篇 |
2007年 | 395篇 |
2006年 | 413篇 |
2005年 | 410篇 |
2004年 | 459篇 |
2003年 | 412篇 |
2002年 | 378篇 |
2001年 | 108篇 |
2000年 | 89篇 |
1999年 | 99篇 |
1998年 | 97篇 |
1997年 | 92篇 |
1996年 | 71篇 |
1995年 | 51篇 |
1994年 | 42篇 |
1993年 | 43篇 |
1992年 | 35篇 |
1991年 | 31篇 |
1990年 | 32篇 |
1989年 | 54篇 |
1988年 | 33篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 23篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1979年 | 15篇 |
1978年 | 15篇 |
1977年 | 18篇 |
1974年 | 13篇 |
1973年 | 16篇 |
1972年 | 18篇 |
排序方式: 共有6777条查询结果,搜索用时 15 毫秒
991.
BACKGROUND: This study aims to assess the psychiatric morbidity of persons at risk of homelessness and to analyze correlations and risk factors between homelessness and mental disorders. METHODS: The sample included 101 citizens of Mannheim, Germany, who were immediately threatened by eviction. Mental disorders were diagnosed using a standardized test, and other factors were also assessed. Data from August 2000 to June 2002 were collected. RESULTS: Acute mental disorders requiring treatment were determined in 79.3% of the study sample. Addiction disorders (alcoholism) played a major role. Personality, anxiety, and affective disorders were even more frequent than in a control group of homeless people in the same region, whereas schizophrenia and other mental disorders were similarly prevalent. Regression analyses confirmed unemployment, alcoholism, and male gender as the most important risk factors for homelessness among people threatened by eviction. CONCLUSIONS: The results suggest that prevention strategies should be multidimensional and interdisciplinary. 相似文献
992.
993.
In rare cases, the diagnosis of hypertrophic and dilated cardiomyopathy (DCM) in children was established postmortem. Our case report deals with the sudden and unexpected death of an 8-year-old boy. The postmortem examination revealed non-obstructive hypertrophy with irregular arrangement of muscular fibers, dilatation of the ventricles, endocardial fibrosis, microfocal vacuolization with enlarged hyperchromatic nuclei, and signs of inflammation with interstitial fibrosis. We present an evolution from idiopathic cardiomyopathy to DCM. To some extent, there were morphologic signs of an inflammatory process that first led us to suspect a specific inflammatory DCM. 相似文献
994.
Oral Langerhans cell histiocytosis. 总被引:1,自引:0,他引:1
Arnd Bartnick Reinhard E Friedrich Kerstin Roeser Rainer Schmelzle 《Journal of cranio-maxillo-facial surgery》2002,30(2):91-96
AIM: Our aim is to compare the different methods of treatment available for Langerhans cell histiocytosis (LCH) in the oral and maxillo-facial region. A classification based on clinical and immunohistochemical data is proposed and a grading for the severity of the disease is proposed. PATIENTS AND METHODS: Records and clinical data of 12 patients were evaluated retrospectively. The patients' ages ranged from 20 months to 47 years. Nine had manifestations in the maxillo-facial region, of which six had a single oral lesion only, with the three remaining patients having multiple lesions in this region. Three patients had lesions in the upper thorax in addition to their oral lesions. Eleven patients were treated surgically with one having been treated previously with steroid-therapy. One patient had already been treated with chemotherapy. The longest follow-up was 16 years. Immunohistochemical stains for antigen-CD-1a, antigen-S-100 and antigen-Ki-67 were performed. A proposal for staging the lesions in the oro-maxillo-facial region was made. The intensity of the antigen-Ki-67 stains was evaluated. RESULTS: Eleven patients exhibited no signs of recurrence whilst only one patient had a recurrence implying that surgical treatment was very effective in eradication and cure of the disorder. It is felt that the number of antigen-Ki-67 positive cells is related to the activity of the disease. CONCLUSION: Langerhans cell histiocytosis should be treated surgically. Only in very severe cases should surgical treatment be complemented with either radio-therapy or chemotherapy. Especially in disseminated cases, chemotherapy would appear to improve the outcome. The antigen Ki-67 as proliferation marker is suggested as a grading parameter of this disease. 相似文献
995.
Sonja Heinzelmann Daniel Böhringer Philip C. Maier Thomas Reinhard 《Acta ophthalmologica. Supplement》2014,92(1):e1-e4
Purpose: Descemet‐stripping automated endothelial keratoplasty (DSAEK) is an advanced method of lamellar endothelial keratoplasty. In comparison with penetrating keratoplasty, visual rehabilitation seems to be faster. Final visual outcome of DSAEK, however, seems to be limited, especially in comparison with Descemet membrane endothelial keratoplasty (DMEK). DSAEK cases without graft failure often do not show any definite correlate for the reduced optical performance. In this study, we tried to correlate visual acuity following DSAEK with interface reflectivity as measured by a rotating Scheimpflug system. Methods: We examined 14 eyes of 13 patients with the pentacam for 2–11 months following DSAEK. Reflectivity of the interface region in the centre of the optical axis as well as central corneal thickness was determined. Statistical correlation between interface reflectivity and best spectacle‐corrected visual acuity, central corneal thickness and follow‐up time was drawn (multifactorial linear regression analysis). Results: Statistically significant correlation between interface reflectivity and BSCVA as well as follow‐up time was found. Reflectivity was highest in regions of interface (metal) particles. There was no statistically significant correlation between interface reflectivity and central corneal thickness. Conclusion: We present a measurable correlate for reduced visual outcome following DSAEK despite a clear graft. Inverse correlation between interface reflectivity and best spectacle‐corrected visual acuity (BSCVA) indicates that irregularities or scarring in the interface region may influence the optical quality following DSAEK. 相似文献
996.
Laura Bredow Lisa Stützel Daniel Böhringer Enken Gundlach Thomas Reinhard Claudia Auw-Haedrich 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2014,252(2):359-365
Background
Since it has been observed that melanocytic lesions can alter their appearance during pregnancy, we analyzed whether hormone receptors are expressed in conjunctival nevi as well as conjunctival melanoma. We further analyzed whether the number of estrogen (ER) or progesterone receptors (PR) might be associated with the disease course in conjunctival melanoma.Methods
Twenty-seven paraffin-embedded samples of conjunctival nevi and 27 conjunctival melanoma specimens were examined using immunohistological analysis with antibodies against PR and ER. The percentage of stained cells were analyzed, taking into account patient gender and age. Out of the melanoma group, all patients with complete data for tumor thickness, tumor localization, age at diagnosis, gender, and follow-up including recurrence, metastasis and tumor-related death were included in the second part of the study (n?=?15), where hormone receptor rates were associated with tumor outcome, regarding recurrences, metastasis or death. Written consent was received from all included patients.Results
Both nevi and melanomas showed high rates of PR- and ER-positive cells. In Nevi, 64?±?25 % of cells stained positive for PR and 35?±?34 % for ER. In melanoma specimens, 68?±?30 % showed PR and 44?±?34 % ER expression. Differences between men and women in expression rates were not statistically significant. Out of 15 melanoma patients (nine female, six male), 53 % (five women and three men) experienced 1—4 recurrences, and four patients developed metastases. The median estimated survival time was 12.2 years. A multivariate survival model taking into account known risk factors for prognosis in conjunctival melanoma confirmed tumor location to be an important predictive factor for outcome (p?=?0.05). The rate of PR or ER did not show a statistically significant correlation with the disease course in our cohort.Conclusions
We observed that conjunctival melanocytic lesions express hormone receptors, which could explain why these tumors can alter their appearance under hormonal changes. Regarding the prognosis of conjunctival melanoma, no statistically significant correlation between hormone receptor expression and event-free survival was found in this analysis. 相似文献997.
The use of the local flora in Switzerland: A comparison of past and recent medicinal plant knowledge
Ethnopharmacological relevance
This analysis of documented medicinal plants of the Swiss Flora over the last two millennia provides a rich source of knowledge on earlier uses of plants and use patterns of the local flora. We ask which local plant species were used during different time periods of the last 2000 years and how the numbers of species and the use intensity of specific plant families, growth forms and habitats changed over time.Materials and methods
Totally 25 herbals from the antiquity, monastic medicine, Renaissance, early modern era and the contemporary time as well as five recent ethnobotanical studies were considered. Use patterns were analysed with the Bayesian approach.Results
A total of 768 species, i.e. 32% of the vascular plants of the Swiss Flora have been documented as medicinal plants. Numbers increase until the monastic period (366 spp.) and the Renaissance (476) and remain relatively stable since then (modern and contemporary era: 477). But, 465 formerly documented species do not occur in the ethnobotanical studies and thus seem not to be used any more. Overall, 104 species are documented through all time periods. Archeophytes, trees and forest plants are generally overrepresented in herbals from all time periods while plants from above the timberline are generally underrepresented. Most widely used are the Lamiaceae and Apiaceae.Conclusion
A constant body of medicinal plant knowledge in Switzerland exists since ancient time. This knowledge was always influenced by knowledge from neighboring countries and no “typical Swiss specialties” seem to exist. Medicinal plants are not randomly chosen from the available flora. Certain species are deliberately introduced others are neglected. This process, which is still ongoing, can be traced back with the help of herbals to the antiquity. 相似文献998.
999.
Andreas Drolz Bernhard Jäger Marlene Wewalka Reinhard Saxa Thomas Horvatits Kevin Roedl Thomas Perkmann Christian Zauner Ludwig Kramer Peter Ferenci Valentin Fuhrmann 《Intensive care medicine》2013,39(7):1227-1237
Purpose
Increased arterial ammonia levels are associated with high mortality in patients with acute liver failure (ALF). Data on the prognostic impact of arterial ammonia is lacking in hypoxic hepatitis (HH) and scarce in critically ill patients with cirrhosis.Methods
The patient cohort comprised 72 patients with HH, 43 patients with ALF, 100 patients with liver cirrhosis and 45 patients without evidence for liver disease. Arterial ammonia concentrations were assessed on a daily basis in all patients and the results were compared among these four patient groups and between 28-day survivors and 28-day non-survivors overall and in each group.Results
Overall 28-day mortality rates in patients with HH, ALF and cirrhosis and in the control group were 54, 30, 49 and 27 %, respectively. Peak arterial ammonia levels differed significantly between transplant-free 28-day survivors and non-survivors in the HH and ALF groups (p < 0.01 for both). Multivariate regression identified peak arterial ammonia concentrations as an independent predictor of 28-day mortality or liver transplantation in patients with HH and ALF, respectively (p < 0.01). There was no association between mortality and arterial ammonia in patients with liver cirrhosis and in the control group. Admission arterial ammonia levels were independently linked to hepatic encephalopathy grades 3/4 in patients with HH (p < 0.01), ALF (p < 0.05) and cirrhosis (p < 0.05), respectively.Conclusions
Elevated arterial ammonia levels indicate a poor prognosis in acute liver injury and are associated with advanced HE in HH, ALF and cirrhosis. Arterial ammonia levels provide additional information in the risk assessment of critically ill patients with liver disease. 相似文献1000.
Tilman Ziegler Jan Horstkotte Claudia Schwab Vanessa Pfetsch Karolina Weinmann Steffen Dietzel Ina Rohwedder Rabea Hinkel Lisa Gross Seungmin Lee Junhao Hu Oliver Soehnlein Wolfgang M. Franz Markus Sperandio Ulrich Pohl Markus Thomas Christian Weber Hellmut G. Augustin Reinhard F?ssler Urban Deutsch Christian Kupatt 《The Journal of clinical investigation》2013,123(8):3436-3445
Septic shock is characterized by increased vascular permeability and hypotension despite increased cardiac output. Numerous vasoactive cytokines are upregulated during sepsis, including angiopoietin 2 (ANG2), which increases vascular permeability. Here we report that mice engineered to inducibly overexpress ANG2 in the endothelium developed sepsis-like hemodynamic alterations, including systemic hypotension, increased cardiac output, and dilatory cardiomyopathy. Conversely, mice with cardiomyocyte-restricted ANG2 overexpression failed to develop hemodynamic alterations. Interestingly, the hemodynamic alterations associated with endothelial-specific overexpression of ANG2 and the loss of capillary-associated pericytes were reversed by intravenous injections of adeno-associated viruses (AAVs) transducing cDNA for angiopoietin 1, a TIE2 ligand that antagonizes ANG2, or AAVs encoding PDGFB, a chemoattractant for pericytes. To confirm the role of ANG2 in sepsis, we i.p. injected LPS into C57BL/6J mice, which rapidly developed hypotension, acute pericyte loss, and increased vascular permeability. Importantly, ANG2 antibody treatment attenuated LPS-induced hemodynamic alterations and reduced the mortality rate at 36 hours from 95% to 61%. These data indicate that ANG2-mediated microvascular disintegration contributes to septic shock and that inhibition of the ANG2/TIE2 interaction during sepsis is a potential therapeutic target. 相似文献