全文获取类型
收费全文 | 12127篇 |
免费 | 687篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 423篇 |
妇产科学 | 263篇 |
基础医学 | 1404篇 |
口腔科学 | 182篇 |
临床医学 | 822篇 |
内科学 | 3203篇 |
皮肤病学 | 317篇 |
神经病学 | 1269篇 |
特种医学 | 553篇 |
外科学 | 1943篇 |
综合类 | 28篇 |
预防医学 | 590篇 |
眼科学 | 94篇 |
药学 | 746篇 |
中国医学 | 13篇 |
肿瘤学 | 988篇 |
出版年
2023年 | 118篇 |
2022年 | 186篇 |
2021年 | 352篇 |
2020年 | 217篇 |
2019年 | 269篇 |
2018年 | 430篇 |
2017年 | 318篇 |
2016年 | 365篇 |
2015年 | 416篇 |
2014年 | 493篇 |
2013年 | 665篇 |
2012年 | 833篇 |
2011年 | 802篇 |
2010年 | 499篇 |
2009年 | 456篇 |
2008年 | 701篇 |
2007年 | 647篇 |
2006年 | 630篇 |
2005年 | 660篇 |
2004年 | 594篇 |
2003年 | 507篇 |
2002年 | 443篇 |
2001年 | 153篇 |
2000年 | 118篇 |
1999年 | 158篇 |
1998年 | 89篇 |
1997年 | 72篇 |
1996年 | 53篇 |
1995年 | 59篇 |
1994年 | 56篇 |
1993年 | 45篇 |
1992年 | 138篇 |
1991年 | 143篇 |
1990年 | 124篇 |
1989年 | 106篇 |
1988年 | 110篇 |
1987年 | 103篇 |
1986年 | 99篇 |
1985年 | 94篇 |
1984年 | 66篇 |
1983年 | 50篇 |
1982年 | 29篇 |
1980年 | 27篇 |
1979年 | 59篇 |
1978年 | 26篇 |
1976年 | 26篇 |
1973年 | 32篇 |
1971年 | 21篇 |
1969年 | 25篇 |
1967年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
121.
G. Pascarella F. Costa R. Del Buono R. Pulitanò A. Strumia C. Piliego E. De Quattro R. Cataldo F. E. Agrò M. Carassiti collaborators 《Anaesthesia》2021,76(11):1492-1498
The pericapsular nerve group (PENG) block is a novel regional anaesthesia technique that aims to provide hip analgesia with preservation of motor function, although evidence is currently lacking. In this single-centre, observer-masked, randomised controlled trial, patients undergoing total hip arthroplasty received pericapsular nerve group block or no block (control group). Primary outcome measure was maximum pain scores (0–10 numeric rating scale) measured in the first 48 h after surgery. Secondary outcomes included postoperative opioid consumption; patient mobilisation assessments; and length of hospital stay. Sixty patients were randomly allocated equally between groups. The maximum pain score of patients receiving the pericapsular nerve group block was significantly lower than in the control group at all time-points, with a median (IQR [range]) of 2.5 (2.0–3.7 [0–7]) vs. 5.5 (5.0–7.0 [2–8]) at 12 h; 3 (2.0–4.0 [0–7]) vs. 6 (5.0–6.0 [2–8]) at 24 h; and 2.0 (2.0–4.0 [0–5]) vs. 3.0 (2.0–4.7 [0–6]) at 48 h; all p < 0.001. Moreover, the pericapsular nerve group showed a significant reduction in opioid consumption, better range of hip motion and shorter time to ambulation. Although no significant difference in hospital length of stay was detected, our results suggest improved postoperative functional recovery following total hip arthroplasty in patients who received pericapsular nerve group block. 相似文献
122.
123.
Giuliante Felice Viganò Luca De Rose Agostino M. Mirza Darius F. Lapointe Réal Kaiser Gernot Barroso Eduardo Ferrero Alessandro Isoniemi Helena Lopez-Ben Santiago Popescu Irinel Ouellet Jean-Francois Hubert Catherine Regimbeau Jean-Marc Lin Jen-Kou Skipenko Oleg G. Ardito Francesco Adam René 《Annals of surgical oncology》2021,28(13):8198-8208
Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to... 相似文献
124.
Riccardo Schiavina Matteo Droghetti Giacomo Novara Lorenzo Bianchi Caterina Gaudiano Valeria Panebianco Marco Borghesi Pietro Piazza Federico Mineo Bianchi Marco Guerra Beniamino Corcioni Michelangelo Fiorentino Francesca Giunchi Paolo Verze Cristian Pultrone Rita Golfieri Angelo Porreca Vincenzo Mirone Eugenio Brunocilla 《Urologic oncology》2021,39(7):433.e1-433.e7
BackgroundWe aim to evaluate the impact of multiparametric magnetic resonance imaging and fusion-target biopsy for early reclassification of patients with low-risk Prostate Cancer in a randomized trial.Materials and methodsBetween 2015 and 2018, patients diagnosed with Prostate Cancer after random biopsy fulfilling PRIAS criteria were enrolled and centrally randomized (1:1 ratio) to study group or control group. Patients randomized to study group underwent multiparametric magnetic resonance imaging at 3 months from enrollment: patients with positive findings (PIRADS-v2>2) underwent fusion-target biopsy; patients with negative multiparametric magnetic resonance imaging or confirmed ISUP - Grade Group 1 at fusion-target biopsy were managed according to PRIAS schedule and 12-core random biopsy was performed at 12 months. Patients in control group underwent PRIAS protocol, including a confirmatory 12-core random biopsy at 12 months. Primary endpoint was a reduction of reclassification rate at 12-month random biopsy in study group at least 20% less than controls. Reclassification was defined as biopsy ISUP Grade Group 1 in >2 biopsy cores or disease upgrading.ResultsA total of 124 patients were randomized to study group (n = 62) or control group (n = 62). Around 21 of 62 patients (34%) in study group had a positive multiparametric magnetic resonance imaging, and underwent fusion-target biopsy, with 11 (17.7%) reclassifications. Considering the intention-to-treat population, reclassification rate at 12-month random biopsy was 6.5% for study group and 29% for control group, respectively (P < 0.001).ConclusionsThe early employment of multiparametric magnetic resonance imaging for active surveillance patients enrolled after random biopsy consents to significantly reduce reclassifications at 12-month random biopsy. 相似文献
125.
Alex M. Hollenberg Noorullah Maqsoodi Amy Phan Aric Huber Ayodeji Jubril Avionna L. Baldwin Noriaki Yokogawa Roman A. Eliseev Addisu Mesfin 《The spine journal》2021,21(7):1205-1216
BACKGROUND CONTEXTBack and neck pain secondary to disc degeneration is a major public health burden. There is a need for therapeutic treatments to restore intervertebral disc (IVD) composition and function.PURPOSETo quantify ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression in IVD specimens collected from patients undergoing surgery for disc degeneration, to correlate ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression in IVD specimens to the 5-level Pfirrmann MRI grading system, and to compare ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression between cervical and lumbar degenerative disc specimens.STUDY DESIGNAn immunohistochemical study assessing ALK3, BMP-2, pSMAD1/5/8, and MMP-13 expression levels in human control and degenerative IVD specimens.METHODSHuman IVD specimens were collected from surgical patients who underwent discectomy and interbody fusion at our institution between 1/2015 and 8/2017. Each patient underwent MRI prior to surgery. The degree of disc degeneration was measured according to the 5-level Pfirrmann MRI grading system. Patients were categorized into either the 1) control group (Pfirrmann grades I-II) or 2) degenerative group (Pfirrmann grades III-V). Histology slides of the collected IVD specimens were prepared and immunohistochemical staining was performed to assess ALK3, BMP-2, pSMAD1/5/8, and MMP-13 expression levels in the control and degenerative specimens. Expression levels were also correlated to the Pfirrmann criteria. Lastly, the degenerative specimens were stratified according to their vertebral level and expression levels between the degenerative lumbar and cervical discs were compared.RESULTSFifty-two patients were enrolled; however, 2 control and 2 degenerative patients were excluded due to incomplete data sets. Of the remaining 48 patients, there were 12 control and 36 degenerative specimens. Degenerative specimens had increased expression levels of BMP-2 (p=.0006) and pSMAD1/5/8 (p<.0001). Pfirrmann grade 3 (p=.0365) and grade 4 (p=.0008) discs had significantly higher BMP-2 expression as compared to grade 2 discs. Pfirrmann grade 4 discs had higher pSMAD1/5/8 expression as compared to grade 2 discs (p<.0001). There were no differences in ALK3 or MMP-13 expression between the control and degenerative discs (p>.05). Stratifying the degenerative specimens according to their vertebral level showed no significant differences in expression levels between the lumbar and cervical discs (p>.05).CONCLUSIONSBMP-2 and pSMAD1/5/8 signaling activity was significantly upregulated in the human degenerative specimens, while ALK3 and MMP-13 expression were not significantly changed. The expression levels of BMP-2 and pSMAD1/5/8 correlate positively with the degree of disc degeneration measured according to the Pfirrmann MRI grading system.CLINICAL SIGNIFICANCEBMP-SMAD signaling represents a promising therapeutic target to restore IVD composition and function in the setting of disc degeneration. 相似文献
126.
Nocturnal Paroxysmal Dystonia with Short-Lasting Attacks: Three Cases with Evidence for an Epileptic Frontal Lobe Origin of Seizures 总被引:9,自引:6,他引:3
Paolo Tinuper Angelina Cerullo Fabio Cirignotta Pietro Cortelli Elio Lugaresi Pasquale Montagna 《Epilepsia》1990,31(5):549-556
The epileptic or nonepileptic origin of nocturnal paroxysmal dystonia (NPD) has been debated. We studied three patients with frequent attacks during non-REM sleep. During prolonged video-EEG monitoring, two patients had a convulsive seizure after a typical NPD episode and on these occasions EEG showed epileptiform discharge. In the three patients, attacks occurred repeatedly with different intensity, representing "fragments" of the same seizure. These fragments of the attack could occur periodically every 20-40 s. We postulate that short NPD attacks are actually epileptic seizures originating from the frontal lobes. The rhythmicity of the episodes may be due to rhythmic oscillation of cortical function during non-REM sleep. 相似文献
127.
U Meyer D Vollmer C Homann R Schuon S Benthaus A Végh E Felszegi U Joos J Piffkò 《Mund-, Kiefer- und Gesichtschirurgie》2000,4(1):14-20
Biomechanical investigations of the mandible are difficult to perform due to a variety of conditions involved. For the appropriate reconstruction of biomechanical properties, a geometrically correct body model has to be established which fits to complex in vivo conditions. The aim of our study was to evaluate the use of finite-element models (FEM) for the assessment of mandibular deformation under mechanical loading. Explanted human mandibles (n = 5) were investigated by strain gauges to determine the individual strain distribution under mechanical loading. FEM analysis based on a computed tomograph (CT) was performed and the results were matched with the test data. Our study demonstrates only minor interindividual differences in the strain distribution for each load studied. The mechanical response in terms of deformation was found to depend mainly on gross geometrical properties and to a minor extent on the various other variables. At all positions the maximum principal strain was tensile, the minimum principal strain was compressive, and the absolute strain values were correlated with the magnitude of the applied force. CT-based FEM analysis revealed the utility of mathematical models to approximate simulated data our experimental results. Hence, FEM analysis is a non-invasive tool in the prediction of biomechanical behaviour of individual mandibles and therefore may help in trauma reconstruction and treatment planning. 相似文献
128.
Dominici Carlo Nicotra Maria Rita Alemaà Stefano Bosman Cesare Castello Manuel A. Donfrancesco Alberto Gallo Pietro Natali Pier Giorgio 《Journal of neuro-oncology》1997,31(1-2):57-64
In neuroblastoma, high levels of mRNA for p14h
trkA
and p75
LNGFR
neurotrophin receptors are predictive of favorable outcome. Their evaluation by Northern blot, however, requires substantial amounts of tissue and this prevents their routine evaluation as well as the possibility for multicenter studies to be easily carried out. In an attempt to overcome these limitations, the feasibility and reliability of determining both neurotrophin receptors on cryostat sections by immunohistochemistry were assessed, and these findings were compared to those obtained from Northern blot analysis. Primary tumor samples from 28 untreated patients at all stages were evaluated by using H10 anti-p140
trkA
and ME20.4 anti-p75
LNGFR
mAbs. Although weak, positiveimmunostaining was found in 9 of 28 tumors for p140
trkA
and in 5 of 28 tumors for p75
LNGFR
. As compared to Northern blot, the concordance rate was 79% (22 of 28 cases) for p140
trkA
(p < 0.05) and 71% (20 of 28 cases) for p75
LNGFR
(p < 0.05). No case negative for Northern blot was found to be positive with immunohistochemistry. Since only high mRNA levels for both receptors have been shown to be clinically relevant, their immunohistochemical detection, although less sensitive than Northern blot, can be just as sufficient and reliable as a prognostic tool, and possibly with a better cost-benefit ratio. 相似文献
129.
Fausto Rossini Pietro Pioltelli Silvia Mingozzi Rino Bregani Franco Viganó Silvia Bolis Ivana Casaroli Eraldo Lanzi Enrico M. Pogliani Gianmarco Corneo 《Supportive care in cancer》1994,2(4):259-265
This study aimed to evaluate the efficacy of amikacine and ceftazidime as an empirical antibiotic therapy for neutropenic patients affected by haematological neoplasms and to investigate the presence of prognostic features suggesting a poor outcome with this antibiotic combination at the onset of infection. This could allow the identification of subgroups of patients with a low rate of response to amikacin/ceftazidime therapy; in these patients different initial empirical therapy may be indicated. The study population comprised 166 severely neutropenic (absolute neutrophil count below 500/l) oncohaematological patients with fever or clinical signs of infection. Multivariate analysis confirmed four negative prognostic factors: 3 or more days of hospitalization at the onset of an infectious episode, a diagnosis of acute myeloid leukaemia, a haematological disease status different from complete remission, the presence of pneumonia. Depending on how many factors are present, cases can be stratified into three groups, of significantly different prognosis: favourable (0 or 1 factor) 76% success; intermediate (2 factors) 52% success; unfavourable (3 or 4 factors) 19% success. At the onset of an infectious episode a subgroup of patients with a very low response rate to empirical amikacin/ceftazidime antibiotic therapy is identifiable, for whom a different therapy is indicated. Because of the high rate of proven or probable fungal infections in this group, the immediate administration of a systemic antifungal therapy, in addition to antibacterial agents, could be considered in these high-risk patients. Studies should be specifically addressed to evaluating a stratification of empirical antibiotic therapy according to risk factors present at the onset of infection. 相似文献
130.
G. Mantovani A. Macciò R. Versace M. Pisano P. Lai S. Esu M. Ghiani D. Dessì E. Turnu M. C. Santona R. Cherchi G. S. Del Giacco 《Journal of molecular medicine (Berlin, Germany)》1995,73(8):409-416
This work was designed to study the proliferative response of tumor-associated lymphocytes (TAL) from neoplastic effusions against autologous tumor cells and the immunophenotype pattern of TAL from neoplastic effusions and that of PBMC of the same patients. We also compared the serum levels of the cytokines interleukin (IL) 1, 2 and 6, tumor necrosis factor- (TNF) and soluble IL-2 receptor (sIL-2R) with those present in neoplastic effusions of the same patients. Moreover, we examined the ability of TAL and peripheral blood mononuclear cells (PBMC) to produce and release the cytokines and sIL-2R and to express membrane CD25 following their stimulation with phytohemagglutinin (PHA) in vitro. Finally, we compared the cytokines/sIL-2R production and membrane CD25 expression by PHA-stimulated PBMC of the patients with neoplastic effusions with a series of 90 cancer patients without neoplastic effusions and 20 normal healthy subjects. Thirteen neoplastic pleural and eight peritoneal effusions were collected from 11 patients with primary lung cancer, 7 with primary epithelial ovarian cancer, 1 with breast cancer, 1 with pleural mesothelioma, and 1 with pancreatic cancer. The proliferative response of TAL from neoplastic effusions against autologous tumor cells was lower than the response to PHA, IL-2, and anti-CD3, but significant. The percentage distribution of CD3+ and CD8+ lymphocyte subpopulations was higher in peritoneal than in pleural effusions, while the CD16+ subset was higher in pleural than in peritoneal effusions. The percentage distribution of CD16+ was significantly lower in pleural effusions than in PBMC of patients with pleural effusions. The CD39 antigen was higher on TAL from peritoneal effusions than on PBMC of the same patients. The levels of IL-1 and sIL-2R in peritoneal effusions did not differ from those measured in the sera of the same patients, while the levels of IL-2, IL-6, and TNF were higher in the peritoneal effusions. The levels of IL-2, IL-6, TNF, and sIL-2R, but not IL-1, in pleural effusions were significantly higher than those found in the sera of the same patients. The amounts of IL-2 and IL-6 produced by TAL were generally higher than those released by PBMC. The secretion of cytokines IL-1, IL-2, and sIL2R by PHA-stimulated PBMC was lower, but IL-1 and IL-6 secretion was higher in cancer patients with neoplastic effusions than in either cancer patients without neoplastic effusions or normal subjects. The CD25 expression on PHA-stimulated PBMC derived from cancer patients with neoplastic effusions was in the same range as that of cancer patients without neoplastic effusions and normal subjects. These findings suggest that TAL may be able to produce cytokines and may be amenable to immune manipulation.Abbreviations
FITC
Fluorescein-isothiocyanate
-
IL
Interleukin
-
mAb
Monoclonal antibody
-
MHC
Major histocompatibility complex
-
NK
Natural killer
-
PBMC
Peripheral blood mononuclear cells
-
PHA
Phytohemagglutinin
-
TAL
Tumor-associated lymphocytes
-
TIL
Tumor-infiltrating lymphocytes
-
TNF
Tumor necrosis factor-
-
sIL-2R
Soluble interleukin-2 receptor 相似文献