全文获取类型
收费全文 | 5931篇 |
免费 | 239篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 146篇 |
儿科学 | 191篇 |
妇产科学 | 200篇 |
基础医学 | 1109篇 |
口腔科学 | 123篇 |
临床医学 | 430篇 |
内科学 | 1008篇 |
皮肤病学 | 140篇 |
神经病学 | 576篇 |
特种医学 | 326篇 |
外国民族医学 | 3篇 |
外科学 | 734篇 |
综合类 | 27篇 |
一般理论 | 2篇 |
预防医学 | 299篇 |
眼科学 | 226篇 |
药学 | 325篇 |
中国医学 | 74篇 |
肿瘤学 | 239篇 |
出版年
2022年 | 38篇 |
2021年 | 52篇 |
2020年 | 40篇 |
2019年 | 74篇 |
2018年 | 75篇 |
2017年 | 61篇 |
2016年 | 73篇 |
2015年 | 107篇 |
2014年 | 122篇 |
2013年 | 186篇 |
2012年 | 275篇 |
2011年 | 284篇 |
2010年 | 204篇 |
2009年 | 186篇 |
2008年 | 263篇 |
2007年 | 252篇 |
2006年 | 275篇 |
2005年 | 259篇 |
2004年 | 259篇 |
2003年 | 270篇 |
2002年 | 237篇 |
2001年 | 99篇 |
2000年 | 87篇 |
1999年 | 97篇 |
1998年 | 78篇 |
1997年 | 61篇 |
1996年 | 37篇 |
1995年 | 44篇 |
1994年 | 33篇 |
1993年 | 35篇 |
1992年 | 53篇 |
1991年 | 43篇 |
1990年 | 47篇 |
1989年 | 39篇 |
1988年 | 55篇 |
1987年 | 46篇 |
1986年 | 37篇 |
1985年 | 54篇 |
1984年 | 34篇 |
1983年 | 31篇 |
1979年 | 34篇 |
1978年 | 32篇 |
1977年 | 35篇 |
1975年 | 33篇 |
1933年 | 36篇 |
1932年 | 29篇 |
1930年 | 38篇 |
1929年 | 45篇 |
1928年 | 42篇 |
1922年 | 32篇 |
排序方式: 共有6178条查询结果,搜索用时 31 毫秒
51.
Sukiennik A Carr DB Bonney I Marchand JE Wurm H Sant GR 《Anesthesia and analgesia》2004,98(3):846-50, table of contents
We investigated the effect of epidural local anesthetic blockade on urinary substance P levels in five patients suffering from painful flare-ups of interstitial cystitis. Urine was collected in 24-h intervals commencing at the onset of an epidural bolus of 0.25% bupivacaine followed by maintenance epidural infusions of 0.05% bupivacaine. Substance P was measured by radioimmunoassay. After initiation of the epidural infusion, urinary substance P levels increased and then declined in all patients. All patients reported a decrease in pain intensity. We hypothesize that acute release, followed by depletion, of substance P from bladder sensory nerve endings accounts for the transient increase of peptide levels in urine and may contribute to the decrease in pain intensity during a 3-day epidural infusion. IMPLICATIONS: Substance P levels in urine initially increased and then declined in a series of 5 patients who achieved pain control by epidural local anesthetic infusion during a flare-up of interstitial cystitis. 相似文献
52.
Magnus Eneroth Jan Larsson Jan Apelqvist Heinrich Reike Markus Salomon Andrew Gough Ali Foster Michael E. Edmonds 《The Foot》2004,14(4):198-203
Background: A complexity of factors determines outcome of foot ulcer infections in diabetic subjects. Variations in patient characteristics, treatment strategies and differences in health care systems may influence outcome. Objective: To evaluate the homogeneity in patients with diabetic foot ulcer infections of sufficient severity to warrant antibiotic treatment in three different European foot care centres. Method: A prospective, observational data collection study with agreed on definitions and the same inclusion and exclusion criteria according to a standardised protocol. Patient and wound characteristics, laboratory tests and physical measurements, antibiotic and surgical treatment during 28 days were recorded in 93 patients. Results: We found significant differences in patient and wound characteristics, in rate and duration of hospitalisation, in antibiotic and surgical treatment, in rate of resolution of infection and in wound healing between centres. Conclusions: Despite using agreed on definitions and the same inclusion and exclusion criteria according to a standardized protocol the heterogeneity between centres of included patients, wound characteristics, management and outcome were surprising. In future multicenter studies, evaluating the effects of a specific treatment of infected foot ulcers in diabetic patients, clear definitions, algorithm for decision making, treatment strategy protocols and knowledge about variations in treatment strategies and healthcare/reimbursement systems in participating centres are needed. 相似文献
53.
Various surgical treatments of chronic subdural hematoma and outcome in 172 patients: is membranectomy necessary? 总被引:11,自引:0,他引:11
BACKGROUND: The initial surgical management of chronic subdural hematoma (CSDH) is still controversial, and a standard therapy does not exist. Because of the advanced age and multiple medical problems of the patients, surgical therapy is frequently associated with complications. METHODS: A retrospective study was performed on 172 patients with CSDH, comparing the efficacy of three different primary surgical methods: drainage of hematoma through two different burr-holes without membranectomy (Group A, n = 38); enlarged craniectomy with a size of about 30 mm craniotomy with partial membranectomy and drainage (Group B, n = 121); and extended craniotomy with partial membranectomy and drainage (Group C, n = 13). RESULTS: Independent of surgical method, the general outcome of the patients was good. The rate of reoperation in the group of burr-hole drainage was 16%, slightly lower than in partial membranectomy with enlarged craniectomy or extended craniotomy with 18% and 23%, respectively. In patients with coagulopathy, the rate of reoperation was 41% (16/43), significantly higher than the rate in noncoagulopathic patients 12% (15/129). CONCLUSIONS: In this study, an extended surgical approach with partial membranectomy has no advantages regarding the rate of reoperation and the outcome. As initial treatment, burr-hole drainage with irrigation of the hematoma cavity and closed-system drainage is recommended. Extended craniotomy with membranectomy is now reserved for instances of acute rebleeding with solid hematoma. 相似文献
54.
Neuhaus J Schulte-Baukloh H Stolzenburg JU Speroni di Fenizio P Horn LC Rüffert H Hartenstein S Burger M Schulze M Schwalenberg T 《World journal of urology》2012,30(5):693-700
Purpose
Dysregulation of neurotransmitter receptors may contribute to bladder overactivity (OAB) symptoms. To address the question whether specific receptor expression patterns are associated with bladder pain syndrome/interstitial cystitis (BPS/IC), we examined the expression of muscarinic, purinergic and histamine receptors in the detrusor.Methods
Detrusor receptor expression was investigated in bladder biopsies of female BPS/IC patients (n?=?44; age 60.64?±?13.78, mean?±?SD) and carcinoma patients (n?=?11; age 58.91?±?12.72) undergoing cystectomy. Protein expression of muscarinic (M2, M3), purinergic (P2X1–3) and histamine receptors (H1, H2) was analysed by confocal immunofluorescence, and gene expression was quantified by real-time polymerase chain reaction (qPCR).Results
M2, P2X1, P2X2 and H1 receptor immunoreactivity (-IR) was significantly enhanced in BPS/IC compared to the control group, while there was no difference for M3-, P2X3- and H2-IR. We calculated a score, which separated BPS/IC from control patients with an AUC of 89.46%, showing 84.09% sensitivity and 90.91% specificity. Patients had a 9.25 times enhanced calculated risk for BPS/IC. In addition, two patient subgroups (M2?>?M3 and M3?>?M2) were observed, which differed in associated purinergic and histamine receptor expression.Conclusions
M2, P2X1, P2X2 and H1 were significantly upregulated in BPS/IC patients, and H2 was occasionally highly overexpressed. There was no significant correlation between receptor protein and gene expression, implying posttranslational mechanisms being responsible for the altered receptor expressions. On the basis of individual receptor profiles, upregulated receptors could be targeted by monotherapy or combination therapy with already approved receptor inhibitors, thereby promoting tailored therapy for patients suffering from BPS/IC-like symptoms. 相似文献55.
Fischer E Bülthoff HH Logothetis NK Bartels A 《Cerebral cortex (New York, N.Y. : 1991)》2012,22(4):865-876
Motion processing regions apart from V5+/MT+ are still relatively poorly understood. Here, we used functional magnetic resonance imaging to perform a detailed functional analysis of the recently described cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex. We used distinct types of visual motion stimuli to compare CSv with V5/MT and MST, including a visual pursuit paradigm. Both V5/MT and MST preferred 3D flow over 2D planar motion, responded less yet substantially to random motion, had a strong preference for contralateral versus ipsilateral stimulation, and responded nearly equally to contralateral and to full-field stimuli. In contrast, CSv had a pronounced preference to 2D planar motion over 3D flow, did not respond to random motion, had a weak and nonsignificant lateralization that was significantly smaller than that of MST, and strongly preferred full-field over contralateral stimuli. In addition, CSv had a better capability to integrate eye movements with retinal motion compared with V5/MT and MST. CSv thus differs from V5+/MT+ by its unique preference to full-field, coherent, and planar motion cues. These results place CSv in a good position to process visual cues related to self-induced motion, in particular those associated to eye or lateral head movements. 相似文献
56.
Nora Lang M.D. Ralf Sodian M.D. † Edward Malec M.D. † Katarzyna Januszewska M.D. † Rainer Kozlik-Feldmann M.D. Robert Dalla Pozza M.D. Armin M. Huber M.D. ‡ Jan Abicht M.D. § Christian Kowalski M.D. § Bruno Reichart M.D. † Heinrich Netz M.D. Christoph Schmitz M.D. † 《Journal of cardiac surgery》2009,24(5):541-543
Abstract The appearance of re-stenosis after repair of an interrupted aortic arch may be a surgical challenge due to adhesions. Here, we describe an approach using off-pump coronary artery bypass grafting techniques to reach the descending aorta through a median sternotomy in a patient with aortic arch stenosis after conduit repair. The 17-year-old patient with diagnoses of interrupted aortic arch and ventricular septal defect presented after two previous operations (one left lateral thoracotomy and one median sternotomy) with a stenosed vascular graft between ascending and descending aorta. Surgery was done via re-sternotomy without cardio-pulmonary bypass. An extraanatomic graft was used to connect ascending and descending aorta. When performing the distal anastomosis, the heart was exposed using a standard suction device. This case demonstrates that the use of modern techniques may facilitate surgical approaches dramatically. In our opinion the above-described technique is the first choice for all patients requiring arch repair following multiple previous operations, performed via sternotomy and thoracotomy. 相似文献
57.
Marcelo F. Di Carli Farbod Asgarzadie Heinrich R. Schelbert Richard C. Brunken Sepehr Rokhsar Jamshid Maddahi 《Journal of nuclear cardiology》1998,5(6):558-566
Background. Stress perfusion imaging can assess effectively the amount of jeopardized myocardium, but its use for identifying underperfused but viable myocardium has yielded variable results. We evaluated the relation between measurements of myocardial perfusion at rest and during pharmacologic stress and the patterns of tissue viability as determined by positron emission tomographic (PET) imaging.Methods and Results. We studied 33 patients with coronary artery disease and left ventricular (LV) dysfunction (LV ejection fraction, 30% ± 8%). PET imaging was used to evaluate regional myocardial perfusion at rest and during pharmacologic stress with [13N]-ammonia as a flow tracer, and to delineate patterns of tissue viability (ie, perfusion-metabolism mismatch or match) using [18F]-deoxyglucose (FDG). We analyzed 429 myocardial regions, of which 229 were dysfunctional at rest. Of these, 30 had normal perfusion and 199 were hypoperfused. A severe resting defect (deficit>40% below normal) predicted lack of significant tissue viability; 31 of 35 regions (89%) had a PET match pattern denoting transmural fibrosis. Although regions with mild or moderate resting defects (deficit <40% below normal) showed evidence of metabolic activity, perfusion measurements alone failed to identify regions with PET mismatch (reflecting hibernating myocardium). Reversible stress defects were observed with slightly higher frequency in regions with a PET mismatch (10 of 37) than in those with a PET match (36 of 162) pattern of viability. A reversible stress defect was a specific (78%) marker, but was a relatively insensitive marker (27%) of viable myocardium as defined by the PET mismatch pattern.Conclusions. In patients with LV dysfunction, the severity of regional contractile abnormalities correlates with the severity of flow deficit at rest. Severe reductions in resting blood flow in these dysfunctional regions identify predominantly nonviable myocardium that is unlikely to have improved function after revascularization. Although dysfunctional myocardium with mild to moderate flow reductions contains variable amounts of viable tissue (as assessed by FDG uptake), flow measurements alone do not distinguish between regions with PET mismatch (potentially reversible dysfunction) and PET match (irreversible dysfunction). The presence of an irreversible defect on stress imaging is a relatively specific (78%) marker of PET match, whereas a reversible stress defect is a rather insensitive (27%) marker of viability, as defined by the PET mismatch pattern. 相似文献
58.
Markus Rothenburger Karin Drebber Tonny D T Tjan Christoph Schmidt Christof Schmid Thomas Wichter Hans Heinrich Scheld Michael Deiwick 《European journal of cardio-thoracic surgery》2003,23(5):703-9; discussion 709
OBJECTIVE: Aortic valve replacement for aortic valve stenosis (AS) and regurgitation (AR) in patients with severe left ventricular (LV) dysfunction contains an increased risk. Few data are available on the outcome of such patients. METHODS: Fifty-five consecutive patients with severe LV dysfunction (ejection fraction, EF; <30%) and aortic valve replacement for AS (n=35) or AR (n=20) were investigated between 1994 and 2001. EF was 25+/-5%, mean transvalvular gradient 26+/-6mmHg (AS), aortic valve area 0.66+/-0.18cm(2) (AS), cardiac index (CI) 2.4+/-0.9l/min/m(2), enddiastolic LV diameter (LVEDD) 64+/-8mm and endsystolic LV diameters (LVESD) was 55+/-3mm. Ninety percent of patients were in New York Heart Association (NYHA) functional class III/IV at admission to the hospital. Concomitant coronary artery bypass grafts (CABG) were performed in 14 patients. Follow-up examinations including chest X-ray, echocardiography, exercise testing, were performed among survivors. RESULTS: The survival rates for AS were: 1-year 76%, 2-year 68.8%, 5-year 64.2%; for AR: 1-year 94.4%, 2-year 86.5%, 5-year 74.2%. NYHA functional class improved from 90% in class III/IV to 45 (AR group) and 24% (AS group) at follow-up (P<0.02). The LVEDD decreased to 54+/-8mm after 1 year. The EF improved to 38+/-4 (AR group) and 40+/-5% (AS group) at follow-up. CONCLUSIONS: Despite severe LV dysfunction, increased 1-year mortality especially in the AS group, aortic valve replacement was associated with improved functional status, symptoms and EF in both groups and in most patients. We, therefore, conclude that aortic valve replacement in patients with severe LV dysfunction can be performed with acceptable risk. 相似文献
59.
Fink AM Lass H Hartleb H Jurecka W Salzer H Steiner A 《Annals of surgical oncology》2008,15(3):848-853
Background One-half of breast cancer patients with positive sentinel lymph node (SN) have no further metastases in the axillary lymph
node basin. The aim of the present study was to identify patients with positive SN who are unlikely to have further metastases
in the axillary lymph node basin, using a new classification of SN, namely the S-classification.
Methods Specimens of positive SN were subjected to a pathological review according to the previously published S-classification. S-stages
of positive SN were correlated with the status of further metastases in the axillary lymph node basin after axillary lymph
node dissection (ALND).
Results Of 117 patients who underwent sentinel lymph node biopsy, 36 (30.8%) had a positive SN and were subjected to level I and II
ALND. The occurrence of positive nonsentinel nodes was significantly related to the S-stage of SN. No patient with stage SI
had additional metastases in the nonsentinel lymph nodes, while 14.3% of patients with SII stage disease and 60.9 % of patients
with SIII disease had other non-SN that were metastatic.
Conclusion S-stages of positive SN are highly predictive for axillary nonsentinel node status. Especially patients with SI sentinel node
metastases appear to be at low risk for further nonsentinel node metastases. 相似文献
60.
Stangelberger A Schally AV Zarandi M Heinrich E Groot K Havt A Kanashiro CA Varga JL Halmos G 《The Prostate》2007,67(12):1339-1353
BACKGROUND: Antagonists of growth hormone-releasing hormone (GHRH) could extend the duration of response of androgen sensitive prostate cancers to androgen deprivation. METHODS: We investigated the effect of new GHRH antagonists MZ-J-7-118 and MZ-J-7-138 and luteinizing hormone-releasing hormone (LHRH) antagonist Cetrorelix or castration on androgen sensitive MDA-PCa-2b and LuCaP-35 prostate cancer models xenografted into nude mice. Animals bearing androgen-independent LuCaP-35V prostatic cancer model were also treated with MZ-J-7-118. RESULTS: Receptors for LHRH and GHRH were present in MDA-PCA-2b, LuCaP-35, and LuCaP-35V tumors. GHRH antagonists increased the inhibitory effect of surgical castration and LHRH antagonists on androgen sensitive MDA-PCa-2b and LuCaP-35 tumors. The time to relapse of androgen-dependent LuCaP-35 tumors was extended by GHRH antagonists. Growth of androgen-independent LuCaP-35V xenografts was also significantly inhibited by MZ-J-7-118. In MDA-PCa-2b tumors treatment with MZ-J-7-118 caused a significant decrease of VEGF and Cetrorelix or its combination with MZ-J-7-118 reduced EGF. The B(max) of EGF receptors was significantly reduced by Cetrorelix, MZ-J-7-118 and their combination. CONCLUSIONS: Our findings suggest that the use of a combination of antagonists of GHRH and LHRH could improve the therapy for androgen sensitive prostate cancer. Antagonists of GHRH could be also considered for treatment of androgen-independent prostate cancers. 相似文献