全文获取类型
收费全文 | 9559篇 |
免费 | 722篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 279篇 |
妇产科学 | 253篇 |
基础医学 | 1507篇 |
口腔科学 | 206篇 |
临床医学 | 1135篇 |
内科学 | 2015篇 |
皮肤病学 | 405篇 |
神经病学 | 896篇 |
特种医学 | 457篇 |
外科学 | 1125篇 |
综合类 | 80篇 |
一般理论 | 3篇 |
预防医学 | 805篇 |
眼科学 | 87篇 |
药学 | 503篇 |
中国医学 | 9篇 |
肿瘤学 | 491篇 |
出版年
2023年 | 46篇 |
2022年 | 55篇 |
2021年 | 129篇 |
2020年 | 98篇 |
2019年 | 162篇 |
2018年 | 178篇 |
2017年 | 150篇 |
2016年 | 213篇 |
2015年 | 200篇 |
2014年 | 244篇 |
2013年 | 405篇 |
2012年 | 453篇 |
2011年 | 433篇 |
2010年 | 268篇 |
2009年 | 278篇 |
2008年 | 375篇 |
2007年 | 433篇 |
2006年 | 443篇 |
2005年 | 393篇 |
2004年 | 354篇 |
2003年 | 350篇 |
2002年 | 356篇 |
2001年 | 290篇 |
2000年 | 308篇 |
1999年 | 309篇 |
1998年 | 186篇 |
1997年 | 136篇 |
1996年 | 141篇 |
1995年 | 114篇 |
1994年 | 126篇 |
1993年 | 94篇 |
1992年 | 238篇 |
1991年 | 168篇 |
1990年 | 177篇 |
1989年 | 202篇 |
1988年 | 177篇 |
1987年 | 159篇 |
1986年 | 136篇 |
1985年 | 119篇 |
1984年 | 131篇 |
1983年 | 88篇 |
1982年 | 66篇 |
1981年 | 63篇 |
1980年 | 47篇 |
1979年 | 70篇 |
1978年 | 47篇 |
1977年 | 56篇 |
1974年 | 46篇 |
1973年 | 46篇 |
1971年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
R. N. Maini P. C. Taylor J. Szechinski K. Pavelka J. Brll G. Balint P. Emery F. Raemen J. Petersen J. Smolen D. Thomson T. Kishimoto 《Arthritis \u0026amp; Rheumatology》2006,54(9):2817-2829
Objective
To establish the safety and efficacy of repeat infusions of tocilizumab (previously known as MRA), a humanized anti–interleukin‐6 (IL‐6) receptor antibody, alone and in combination with methotrexate (MTX), for the treatment of rheumatoid arthritis (RA).Methods
The study group comprised 359 patients with active RA in whom the response to MTX was inadequate. During a stabilization period, these patients received their current dose of MTX for at least 4 weeks. Following stabilization, they were randomized to 1 of 7 treatment arms, as follows: tocilizumab at doses of 2 mg/kg, 4 mg/kg, or 8 mg/kg either as monotherapy or in combination with MTX, or MTX plus placebo.Results
A 20% response (improvement) according to the American College of Rheumatology criteria (ACR20 response) was achieved by 61% and 63% of patients receiving 4 mg/kg and 8 mg/kg of tocilizumab as monotherapy, respectively, and by 63% and 74% of patients receiving those doses of tocilizumab plus MTX, respectively, compared with 41% of patients receiving placebo plus MTX. Statistically significant ACR50 and ACR70 responses were observed in patients receiving combination therapy with either 4 mg/kg or 8 mg/kg of tocilizumab plus MTX (P < 0.05). A dose‐related reduction in the Disease Activity Score in 28 joints was observed from week 4 onward, in all patients except those receiving monotherapy with 2 mg/kg of tocilizumab. In the majority of patients who received 8 mg/kg of tocilizumab, the C‐reactive protein level/erythrocyte sedimentation rate normalized, while placebo plus MTX had little effect on these laboratory parameters. Tocilizumab was mostly well tolerated, with a safety profile similar to that of other biologic and immunosuppressive therapies. Alanine transaminase and aspartate transaminase levels followed a sawtooth pattern (rising and falling between infusions). There were moderate but reversible increases in the nonfasting total cholesterol and triglyceride levels and reversible reductions in the high‐density lipoprotein cholesterol and neutrophil levels. There were 2 cases of sepsis, both of which occurred in patients who were receiving combination therapy with 8 mg/kg of tocilizumab plus MTX.Conclusion
These results indicate that targeted blockade of IL‐6 signaling is a highly efficacious and promising means of decreasing disease activity in RA.992.
Sakariassen PØ Prestegarden L Wang J Skaftnesmo KO Mahesparan R Molthoff C Sminia P Sundlisaeter E Misra A Tysnes BB Chekenya M Peters H Lende G Kalland KH Øyan AM Petersen K Jonassen I van der Kogel A Feuerstein BG Terzis AJ Bjerkvig R Enger PØ 《Proceedings of the National Academy of Sciences of the United States of America》2006,103(44):16466-16471
In this work, highly infiltrative brain tumors with a stem-like phenotype were established by xenotransplantation of human brain tumors in immunodeficient nude rats. These tumors coopted the host vasculature and presented as an aggressive disease without signs of angiogenesis. The malignant cells expressed neural stem cell markers, showed a migratory behavior similar to normal human neural stem cells, and gave rise to tumors in vivo after regrafting. Serial passages in animals gradually transformed the tumors into an angiogenesis-dependent phenotype. This process was characterized by a reduction in stem cells markers. Gene expression profiling combined with high throughput immunoblotting analyses of the angiogenic and nonangiogenic tumors identified distinct signaling networks in the two phenotypes. Furthermore, proinvasive genes were up-regulated and angiogenesis signaling genes were down-regulated in the stem-like tumors. In contrast, proinvasive genes were down-regulated in the angiogenesis-dependent tumors derived from the stem-like tumors. The described angiogenesis-independent tumor growth and the uncoupling of invasion and angiogenesis, represented by the stem-like cancer cells and the cells derived from them, respectively, point at two completely independent mechanisms that drive tumor progression. This article underlines the need for developing therapies that specifically target the stem-like cell pools in tumors. 相似文献
993.
Mikkel Andreassen Jens Faber Andreas Kjær Claus Leth Petersen Lars Østergaard Kristensen 《Pituitary》2011,14(1):1-10
Assessed by conventional echocardiography the influence of growth hormone deficiency (GHD) and effects of replacement therapy
on left ventricle (LV) function and mass (LVM) have shown inconsistent results. We aimed to evaluate cardiac function before
and during replacement therapy employing the gold standard method cardiac magnetic resonance imaging (CMRI) and measurements
of circulating levels of B-type natriuretic peptides. Sixteen patients (8 males and 8 females, mean age 49 years (range 18–75))
with severe GHD and 16 matched control subjects were included. CMRI was performed at baseline and after 1 year of GH replacement
therapy. IGF-I, B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) were measured after 0, 1, 2, 3, 6 and
12 months of treatment. IGF-I Z-score increased from (median (IQR)) −2.3 (−3.8 to −1.4) to 0.5 (−0.3 to 1.7). LVM index (LVMI),
ejection fraction (range 63–80%), cardiac output index and levels of BNP and NT-proBNP were similar at baseline in patients
compared to controls (P-values from 0.09 to 0.37). The patients had significantly smaller LV end-diastolic volume index (P = 0.032) and end-systolic volume index (P = 0.038). No significant change in LV systolic function or LVM occurred during 1 year of GH treatment. BNP levels were unchanged
(P = 0.88), whereas NT-proBNP tended to decrease (P = 0.052). Assessed by the highly sensitive and precise CMRI method, untreated GHD was not associated with impaired systolic
function or reduced LVMI and 1 year of GH replacement using physiological doses did not influence cardiac mass or function. 相似文献
994.
Kornblit B Masmas T Madsen HO Ryder LP Svejgaard A Jakobsen B Sengeløv H Olesen G Heilmann C Dickmeiss E Petersen SL Vindeløv L 《Bone marrow transplantation》2008,41(10):851-859
We analysed the outcome and hospitalization requirements of the first 100 patients (Hodgkin's disease (HD), N=13; multiple myeloma (MM), N=14; CLL, N=12; non-Hodgkin's lymphoma (NHL), N=17; myelodysplastic syndrome (MDS), N=18; AML, N=24 and CML, N=2) treated in Denmark with haematopoietic cell transplantation after non-myeloablative conditioning with TBI 2 Gy+/-fludarabine. The cumulative incidence of acute GVHD grade II-IV and extensive chronic GVHD was 67 and 49%. After a median follow-up of 534 days, the overall survival, PFS, relapse-related mortality and treatment-related mortality were 59, 50, 25 and 17%, respectively. Patients with CLL, NHL, AML and MDS with <5% blasts at any time had a favourable outcome with a PFS of 61-71%. Patients with MM, HD and MDS and a history of > or =5% blasts had a less favourable outcome with a PFS of 19-38% (P=0.001). The cumulative incidence of discontinuation of immunosuppression was 37%. During the first and second year post transplant, patients experienced a mean of 41 and 13 outpatient clinic visits, and 53 and 16 days of hospitalization. Sixteen patients were admitted to the intensive care unit, of whom eight are still alive. In conclusion, transplantation outcomes were encouraging, but complications requiring admission and outpatient clinic visits occur frequently post transplant. 相似文献
995.
Alves TC Befroy DE Kibbey RG Kahn M Codella R Carvalho RA Falk Petersen K Shulman GI 《Hepatology (Baltimore, Md.)》2011,53(4):1175-1181
Pyruvate dehydrogenase plays a critical role in the regulation of hepatic glucose and fatty acid oxidation; however, surprisingly little is known about its regulation in vivo. In this study we examined the individual effects of insulin and substrate availability on the regulation of pyruvate dehydrogenase flux (V(PDH) ) to tricarboxylic acid flux (V(TCA) ) in livers of awake rats with lipid-induced hepatic insulin resistance. V(PDH) /V(TCA) flux was estimated from the [4-(13) C]glutamate/[3-(13) C]alanine enrichments in liver extracts and assessed under conditions of fasting and during a hyperinsulinemic-euglycemic clamp, whereas the effects of increased plasma glucose concentration on V(PDH) /V(TCA) flux was assessed during a hyperglycemic clamp in conjunction with infusions of somatostatin and insulin to maintain basal concentrations of insulin. The effects of increases in both glucose and insulin on V(PDH) /V(TCA) were examined during a hyperinsulinemic-hyperglycemic clamp. The effects of chronic lipid-induced hepatic insulin resistance on this flux were also examined by performing these measurements in rats fed a high-fat diet for 3 weeks. Using this approach we found that fasting V(PDH) /V(TCA) was reduced by 95% in rats with hepatic insulin resistance (from 17.2 ± 1.5% to 1.3 ± 0.7%, P < 0.00001). Surprisingly, neither hyperinsulinemia per se or hyperglycemia per se were sufficient to increase V(PDH) /V(TCA) flux. Only under conditions of combined hyperglycemia and hyperinsulinemia did V(PDH) /V(TCA) flux increase (44.6 ± 3.2%, P < 0.0001 versus basal) in low-fat fed animals but not in rats with chronic lipid-induced hepatic insulin resistance. CONCLUSION: These studies demonstrate that the combination of both hyperinsulinemia and hyperglycemia are required to increase V(PDH) /V(TCA) flux in vivo and that this flux is severely diminished in rats with chronic lipid-induced hepatic insulin resistance. 相似文献
996.
Background
Various sequelae which might lead to reintervention have been described after stapled rectal mucosectomy for hemorrhoids. One potential treatment modality for persistent complaints after stapled hemorrhoidopexy (SHP) or stapling for rectocele is the so-called agraffectomy (removal of the retained staples). This treatment option means a further procedure that can range from removal of the staples through the anoscope to removal of the entire staple line with the associated scar tissue. 相似文献997.
Birk S Petersen KA Kruuse C Guieu R Jonassen O Eisert W Olesen J 《Cephalalgia : an international journal of headache》2005,25(5):369-377
Adenosine is an endogenous neurotransmitter that is released from the brain during hypoxia and relaxes isolated human cerebral arteries. Many cerebral artery dilators cause migraine attacks. However, the effect of intravenous adenosine on headache and cerebral artery diameter has not previously been investigated in man and reports regarding the effect of intravenous adenosine on cerebral blood flow are conflicting. Twelve healthy participants received adenosine 80, 120 microg kg(-1) min(-1) and placebo intravenously for 20 min, in a double-blind, three-way, crossover, randomized design. Headache was rated on a verbal scale (0-10). Regional cerebral blood flow (rCBF) with 133Xe inhalation and single-photon emission computed tomography (SPECT) and MCA flow velocity (V(MCA)) with transcranial Doppler, were measured in direct sequence. Six participants developed headache during 80 microg kg(-1) min(-1) and six during 120 microg kg(-1) min(-1) compared with none on placebo (P = 0.006). The headache was very mild and predominantly described as a pressing sensation. When correcting data for adenosine-induced hyperventilation, no significant changes in rCBF (P = 0.22) or V(MCA) (P = 0.16) were found between treatments. A significant dilation of the superficial temporal artery (STA) was seen (P < 0.001). These results show that circulating adenosine has no effect on rCBF or V(MCA), while it dilates the STA and causes very mild headache. 相似文献
998.
Steffen E Petersen Joseph B Selvanayagam Jane M Francis Saul G Myerson Frank Wiesmann Matthew D Robson Ingegerd Ostman-Smith Barbara Casadei Hugh Watkins Stefan Neubauer 《Journal of cardiovascular magnetic resonance》2005,7(3):551-558
PURPOSE: Determination of the underlying etiology of left ventricular hypertrophy (LVH) is a common, challenging, and critical clinical problem. The authors aimed to test whether pathological LVH, such as occurs in hypertrophic cardiomyopathy (HCM), hypertensive heart disease, or aortic stenosis, and physiological LVH in athletes, can be distinguished by means of left ventricular volume and geometric indices, derived from cardiovascular magnetic resonance imaging. METHODS: A total of 120 subjects were studied on a 1.5 Tesla MR (Sonata, Siemens Medical Solutions, Erlangen, Germany) scanner, comprising healthy volunteers (18), competitive athletes (25), patients with HCM (35), aortic stenosis (24), and hypertensive heart disease (18). Left ventricular mass index, ejection fraction, end-diastolic, end-systolic and stroke volume index, diastolic wall thickness, wall thickness ratio and diastolic and systolic wall-to-volume ratios were determined. RESULTS: Left ventricular (LV) mass indices were similar for all forms of LVH (p > 0.05), which were at least 35% higher than those obtained in healthy volunteers (p < 0.05). Multiple logistic regression showed that the percentage of correctly predicted diagnoses was 100% for athlete's heart, 80% for hypertrophic cardiomyopathy, 54% for aortic stenosis, and 22% for hypertensive heart disease. Using a receiver operating curve-determined cut-off value for diastolic wall-to-volume ratio of less than 0.15 mm x m2 x ml(-1), athletes' hearts could be differentiated from all forms of pathological cardiac hypertrophy with 99% specificity. CONCLUSIONS: Athlete's heart can be reliably distinguished from all forms of pathological cardiac hypertrophy using CMR-derived LV volume and geometric indices, but pathological forms of LVH present with overlapping cardiac hypertrophy phenotypes. This capability of CMR should be of high clinical value. 相似文献
999.
Background
Few studies have described patients with foregut dysmotility in inflammatory bowel disease. The aim of this case series was to evaluate clinical characteristics of 5 patients with inflammatory bowel disease and symptoms and signs of upper gut dysmotility. 相似文献1000.
Urnes J Farup PG Lydersen S Petersen H 《European journal of gastroenterology & hepatology》2007,19(12):1104-1110
OBJECTIVES: Gastro-oesophageal reflux disease (GORD) is chronic, affects 8-20% of the population, impairs quality of life (QoL) and generates substantial health-related costs. Patient education is intended to improve patients' disease-related competency, potentially enabling them to deal more efficiently with their disease, eventually improving QoL and reducing healthcare cost. This study aimed to investigate the effects of a group-based education programme for patients with mild GORD. METHODS: Patients with GORD were randomly allocated to education (n=102) or control (n=109). The education programme was designed as a structured dialogue conveying medical information about the pathophysiology and prognosis, pharmacological and nonpharmacological treatment of GORD, patients' rights and use of healthcare. Outcomes were measured using general QoL [General Health Questionnaire-30 (GHQ-30)], disease-specific QoL [Digestive Symptoms and Impact Questionnaire (DSIQ)], global QoL and healthcare use at 2 and 12 months after the educational programme. RESULTS: No statistically significant differences were found in GHQ-30, DSIQ or global QoL at 2 or 12 months' follow-up between the GORD-education group and controls. In the GORD-education group, patients who had completed primary school education only showed improved QoL at 12 months on both GHQ and DSIQ, whereas patients who had completed advanced schooling showed no change. No difference was found between the groups in their use of healthcare. CONCLUSION: A group-based education programme for patients with mild GORD showed no effect on QoL or use of healthcare. Subgroup analyses showed improved QoL only in patients with primary school education, who had been allocated to GORD education. 相似文献