全文获取类型
收费全文 | 1216643篇 |
免费 | 85652篇 |
国内免费 | 4135篇 |
专业分类
耳鼻咽喉 | 17252篇 |
儿科学 | 31537篇 |
妇产科学 | 31315篇 |
基础医学 | 173909篇 |
口腔科学 | 36756篇 |
临床医学 | 105421篇 |
内科学 | 239569篇 |
皮肤病学 | 26028篇 |
神经病学 | 93163篇 |
特种医学 | 46560篇 |
外国民族医学 | 160篇 |
外科学 | 194194篇 |
综合类 | 27152篇 |
现状与发展 | 2篇 |
一般理论 | 309篇 |
预防医学 | 76293篇 |
眼科学 | 29904篇 |
药学 | 95872篇 |
4篇 | |
中国医学 | 4175篇 |
肿瘤学 | 76855篇 |
出版年
2019年 | 8797篇 |
2018年 | 13286篇 |
2017年 | 10310篇 |
2016年 | 11231篇 |
2015年 | 12787篇 |
2014年 | 17529篇 |
2013年 | 24697篇 |
2012年 | 33836篇 |
2011年 | 35050篇 |
2010年 | 20794篇 |
2009年 | 19801篇 |
2008年 | 33162篇 |
2007年 | 35186篇 |
2006年 | 35551篇 |
2005年 | 33775篇 |
2004年 | 32303篇 |
2003年 | 30972篇 |
2002年 | 30139篇 |
2001年 | 72767篇 |
2000年 | 74548篇 |
1999年 | 61916篇 |
1998年 | 14697篇 |
1997年 | 12661篇 |
1996年 | 12319篇 |
1995年 | 11484篇 |
1994年 | 10524篇 |
1993年 | 9715篇 |
1992年 | 45674篇 |
1991年 | 43277篇 |
1990年 | 41587篇 |
1989年 | 40700篇 |
1988年 | 36912篇 |
1987年 | 35961篇 |
1986年 | 33474篇 |
1985年 | 31741篇 |
1984年 | 22439篇 |
1983年 | 18859篇 |
1982年 | 9753篇 |
1979年 | 19567篇 |
1978年 | 13036篇 |
1977年 | 11219篇 |
1976年 | 9591篇 |
1975年 | 10570篇 |
1974年 | 12742篇 |
1973年 | 11998篇 |
1972年 | 11451篇 |
1971年 | 10915篇 |
1970年 | 10274篇 |
1969年 | 9737篇 |
1968年 | 8864篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献12.
N. V. Bashmakova G. N. Chistiakova I. A. Gazieva Y. M. Trapeznikova D. O. Mazurov 《Gynecological endocrinology》2015,31(10):31-33
AbstractThis study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos. 相似文献
13.
Amy Y. Zhang Christopher Burant Alex Z. Fu Gerald Strauss Donald R. Bodner Lee Ponsky 《Journal of psychosocial oncology》2020,38(2):210-227
AbstractPurpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.Design: Secondary analysis of data collected from a clinical trial.Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI. 相似文献
14.
Lalia Y. Ibrahim Krank P. DiFilippo Geremy E. Steed Manuel D. Cerqueira 《Journal of nuclear cardiology》2006,13(6):855-866
Conclusion Several quality-control measures take place before (patient and camera preparation) and during SPECT acquisition to achieve
high-quality images. Not uncommonly, technologists and physicians are left with suboptimal images that have to be addressed
to reach the “right answer” for patient diagnosis and hence management. In many cases patients may be reimaged, especially
if the problem is detected early, but in other cases either the patient has left the nuclear laboratory or there is an inevitable
problem that, even with reimaging, will not be resolved. In these situations the technologist and physician have to seek the
available techniques to obtain the best images possible. These resources are discussed in this issue as an aid in quality
control to obtain the best possible images. 相似文献
15.
ZusammenfassungHintergrund Bedingt durch die intraoperative Katecholaminsekretion mit hämodynamischen Veränderungen, einem größeren Tumordurchmesser und einer deutlichen Neovaskularisation ist die Adrenalektomie beim Phäochromozytom im Vergleich zu anderen Nebennierenerkrankungen schwieriger und potenziell komplikationsträchtiger. Ziel unserer Studie war die Frage, ob das Risiko intraoperativer kardiovaskulärer Komplikationen durch das minimal-invasive Vorgehen potenziert wird.Patienten und Methodik Im Zeitraum zwischen Februar 1992 und Mai 2005 wurden in unserer Klinik 82 Eingriffe wegen eines Phäochromozytoms bei 71 Patienten durchgeführt. Davon wurden 8 (1) Patient(en) bi-(tri-)lateral adrenalektomiert und bei 2 Patienten erfolgte eine ipsilaterale Rezidivoperation. Eingeschlossen sind 5 weitere Patienten mit Rezidiv nach Erstoperation vor 1992. Sechsunddreißig Eingriffe erfolgten konventionell (transperitoneal n=35, retroperitoneal n=1) und 46 Operationen endoskopisch (transperitoneal n=28, retroperitoneal n=18), davon keine Konversion zum offenen Vorgehen.Ergebnisse Das mediane Alter zum Zeitpunkt der Operation betrug 45 (24–75) Jahre bei einer Anamnesedauer von 12 (0–180) Monaten. Die offen operierten Phäochromozytome waren mit 5,5 (1–19) cm vs. 3,5 (0,5–8) cm (endoskopisch) signifikant größer (p=0,0011). Patienten mit endoskopischer, insbesondere mit retroperitoneoskopischer Adrenalektomie hatten im Vergleich zum konventionellen Vorgehen intraoperativ höhere systolische und diastolische maximale Blutdruckwerte sowie Spitzen über 200 mmHg (statistisch nicht signifikant). Faktoren mit möglichem Einfluss auf intraoperative hämodynamische Veränderungen waren in der multivariaten Analyse das Geschlecht (p=0,0107), der operative Zugangsweg (p=0,0153), das Patientenalter (p=0,0364) und die Tumorgröße (p=0,0484). Die postoperative stationäre Verweildauer war nach endoskopischer Operation signifikant kürzer (p<0,0001).Schlussfolgerung Die endoskopische Adrenalektomie beim Phäochromozytom ist in der Routine ohne vermehrtes Risiko kardiovaskulärer Komplikationen die Methode der Wahl. Das offene Vorgehen sollte extraadrenalen Befunden oder sehr großen Tumoren mit Malignitätsverdacht vorbehalten bleiben. 相似文献
16.
17.
This study was undertaken to test the effect of sequential administration of an opioid and intravenous cholecystokinin (CCK) on gallbladder ejection fraction. METHODS: Forty-nine patients who had received an opioid underwent quantitative cholescintigraphy with octapeptide of CCK (CCK-8). Gallbladder ejection fraction and CCK-8-induced paradoxical filling were calculated. RESULTS: In the basal state, more of the hepatic bile entered the gallbladder (67%) than the small intestine (33%). After CCK-8 infusion, gallbladder ejection fraction was low in 37 (76%) of 49 patients and normal in 12 (24%). All 5 types of opioids lowered ejection fraction. CCK-induced paradoxical filling of the gallbladder was noted in 7 patients, but only one showed paradoxical filling of greater than 20% and none had a normal gallbladder ejection fraction. The lowering effect of opioids on gallbladder ejection fraction may last as long as 18 h after intake. CONCLUSION: CCK-8 produced a normal gallbladder ejection fraction in 24% of patients who had received an opioid and thus could exclude both acute and chronic cholecystitis during a single hepatobiliary study. 相似文献
18.
T C Friedman 《Experimental and clinical endocrinology & diabetes》2006,114(7):356-360
The overnight one-mg dexamethasone suppression test has been used for many years to screen for Cushing's syndrome. This test has usually been evaluated in controls versus patients with severe hypercortisolism. Under these conditions, the overnight dexamethasone suppression test has been reported to have high sensitivity and specificity. The objective of this study was to determine the sensitivity of the one mg overnight dexamethasone suppression test in patients with mild and/or periodic Cushing's syndrome. Therefore, an overnight dexamethasone suppression test was performed in 17 consecutive patients presenting to an endocrinology clinic with signs and symptoms of hypercortisolemia who were later proven to have Cushing's syndrome. The majority of patients were found to have both mild and periodic hypercortisolism. One mg of dexamethasone was given at midnight and a plasma cortisol was measured by radioimmunoassay at 08:00 the following morning. Using a cut-off for a morning cortisol following overnight dexamethasone of > 5 microg/dL, only three of 17 patients failed to suppress to a value less than this cut-off (sensitivity 18 %). A cut-off of > 2 microg/dL gave similar sensitivity. Even with a stringent cut-off point of > 1.8 microg/dL, only seven of 17 patients failed to suppress to a value less than this cut-off point (sensitivity of 41 %). These results demonstrate that the great majority of patients with mild and/or periodic Cushing's syndrome suppress to overnight dexamethasone. Since patients with mild and/or periodic Cushing's syndrome are the patients in whom the identification of hypercortisolism is difficult, our results from this relatively small study suggest that this test should no longer be used to exclude these patients from further workup for Cushing's syndrome. 相似文献
19.
A I D'hulst K R Bracke T Maes J L De Bleecker R A Pauwels G F Joos G G Brusselle 《The European respiratory journal》2006,28(1):102-112
Chronic obstructive pulmonary disease (COPD) is characterised by a local pulmonary inflammatory response to respiratory pollutants and by systemic inflammation. Tumour necrosis factor (TNF)-alpha has been implicated in systemic effects of COPD and operates by binding the p55 (R1) and p75 (R2) TNF-alpha receptors. To investigate the contribution of each TNF-alpha receptor in the pathogenesis of COPD, the present study examined the effects of chronic air or cigarette smoke (CS) exposure in TNF-alpha R1 knockout (KO) mice, TNF-alpha R2 KO mice and wild type (WT) mice. CS was found to significantly increase the protein levels of soluble TNF-alpha R1 (by four-fold) and TNF-alpha R2 (by 10-fold) in the bronchoalveolar lavage of WT mice. After 3 months, CS induced a prominent pulmonary inflammatory cell influx in WT and TNF-alpha R1 KO mice. In TNF-alpha R2 KO mice, CS-induced pulmonary inflammation was clearly attenuated. After 6 months, no emphysema was observed in CS-exposed TNF-alpha R2 KO mice in contrast to WT and TNF-alpha R1 KO mice. CS-exposed WT and TNF-alpha R1 KO mice failed to gain weight, whereas the body mass of TNF-alpha R2 KO mice was not affected. These current findings suggest that both tumour necrosis factor-alpha receptors contribute to the pathogenesis of chronic obstructive pulmonary disease, but tumour necrosis factor-alpha receptor-2 is the most active receptor in the development of inflammation, emphysema and systemic weight loss in this murine model of chronic obstructive pulmonary disease. 相似文献
20.
S. Spinty H. Rogozinski G. T. Lealman J. E. Wraith 《Journal of inherited metabolic disease》2003,25(8):697-698
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy. 相似文献