全文获取类型
收费全文 | 3706篇 |
免费 | 324篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 80篇 |
妇产科学 | 134篇 |
基础医学 | 426篇 |
口腔科学 | 54篇 |
临床医学 | 408篇 |
内科学 | 855篇 |
皮肤病学 | 52篇 |
神经病学 | 314篇 |
特种医学 | 57篇 |
外国民族医学 | 1篇 |
外科学 | 563篇 |
综合类 | 31篇 |
一般理论 | 1篇 |
预防医学 | 244篇 |
眼科学 | 163篇 |
药学 | 154篇 |
中国医学 | 2篇 |
肿瘤学 | 458篇 |
出版年
2022年 | 34篇 |
2021年 | 66篇 |
2020年 | 52篇 |
2019年 | 68篇 |
2018年 | 62篇 |
2017年 | 63篇 |
2016年 | 66篇 |
2015年 | 76篇 |
2014年 | 93篇 |
2013年 | 116篇 |
2012年 | 176篇 |
2011年 | 193篇 |
2010年 | 101篇 |
2009年 | 86篇 |
2008年 | 171篇 |
2007年 | 176篇 |
2006年 | 175篇 |
2005年 | 172篇 |
2004年 | 166篇 |
2003年 | 175篇 |
2002年 | 156篇 |
2001年 | 128篇 |
2000年 | 136篇 |
1999年 | 128篇 |
1998年 | 46篇 |
1997年 | 36篇 |
1996年 | 24篇 |
1995年 | 24篇 |
1994年 | 28篇 |
1993年 | 27篇 |
1992年 | 78篇 |
1991年 | 81篇 |
1990年 | 75篇 |
1989年 | 66篇 |
1988年 | 67篇 |
1987年 | 48篇 |
1986年 | 46篇 |
1985年 | 48篇 |
1984年 | 41篇 |
1983年 | 29篇 |
1982年 | 41篇 |
1981年 | 29篇 |
1979年 | 31篇 |
1978年 | 20篇 |
1977年 | 30篇 |
1975年 | 19篇 |
1974年 | 27篇 |
1973年 | 33篇 |
1972年 | 30篇 |
1969年 | 31篇 |
排序方式: 共有4043条查询结果,搜索用时 15 毫秒
1.
Vincenzo Levi Andrea Franzini Andrea Di Cristofori Giulio Bertani Mauro Pluderi 《The journal of spinal cord medicine》2020,43(5):714-718
Context: Treatment of primary spinal syringomyelia is still controversial. Among others, shunting syrinx fluid to the subarachnoid, peritoneal or pleural space has been utilized with varying success. Shunt obstruction, migration, and infection represent the most common complications of these procedures. Findings: The authors present the case of an 81-year-old woman who developed an unusual neurological deterioration resembling a subacute posttraumatic ascending myelopathy (SPAM) after the insertion of a syringosubarachnoid shunt for the treatment of slow-growing D10 syringomyelia. Conclusion/Clinical Relevance: To date, no cases of SPAM secondary to the insertion of a syringosubarachnoid shunt for the treatment of syringomyelia have been reported. The potential pathogenesis related to this phenomenon is discussed. 相似文献
2.
O’Beirne Sarah L. Chazen J. Levi Cornman-Homonoff Joshua Carey Bridget T. Gelbman Brian D. 《Lung》2019,197(6):727-733
Lung - Diaphragmatic paralysis (DP) is an important cause of dyspnea with many underlying etiologies; however, frequently no cause is identified despite extensive investigation. We hypothesized... 相似文献
3.
4.
Peter Marhofer Malachy Columb Phil M. Hopkins Manfred Greher Daniela Marhofer Max R. Levi Bienzle Markus Zeitlinger 《British journal of anaesthesia》2019,122(4):525-531
Background
The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine.Methods
Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome.Results
All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85–7.62) h in the control group, 7.37 (5.78–7.93) h in the perineural group and 7.37 (6.10–7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups.Conclusion
Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve.Clinical trial registration
DRKS, 00014604; EudraCT, 2018-001221-98. 相似文献5.
S. Nishida J. J. Gaynor N. Nakamura F. Butt H. G. Illanes J. Kadono G. W. Neff D. M. Levi J. I. Moon G. Selvaggi T. Kato P. Ruiz A. G. Tzakis J. R. Madariaga 《American journal of transplantation》2006,6(1):140-149
A retrospective study of 1058 liver transplant recipients was performed to determine: (i) the incidence, etiology, timing, clinical features and treatment of refractory ascites (RA), (ii) risk factors for RA development, (iii) predictors of RA disappearance, (iv) predictors of survival following RA and (v) the impact of RA on patient survival. Sixty-two patients (5.9%) developed RA and its disappearance occurred in 27/62 cases. Patients having hepatitis C virus (HCV) had a significantly higher hazard rate of developing RA (p < 0.00001). No other baseline characteristic was associated with RA. Cox stepwise regression analysis of the hazard rate of RA disappearance found two significant factors: HCV recurrence as the reason for developing RA implied a poorer outcome (p = 0.006), whereas an unknown reason implied a favorable outcome (p = 0.02). In addition, survival following RA was significantly poorer among patients having bacterial peritonitis or HCV recurrence. Finally, the mortality rate was significantly (nearly 8.6 times) higher in patients following RA development while it was ongoing (p < 0.00001); however, if the RA disappeared, then the additional risk of death also disappeared. This study illustrates the importance of developing an optimal treatment strategy to (i) effectively treat RA if it develops and (ii) prevent hepatitis C recurrence. 相似文献
6.
Laureano Fernández-Cruz Rebeca Cosa Laia Blanco Sammy Levi Miguel-Angel López-Boado Salvador Navarro 《Journal of gastrointestinal surgery》2007,11(12):1607-1622
Laparoscopic pancreatic surgery (LPS) has seen significant development but much of the knowledge refers to small and benign
pancreatic tumors. This study aims to evaluate the feasibility, safety, and long-term outcome of the laparoscopic approach
in patients with benign, premalignant, and overt malignant lesions of the pancreas. This study, currently, is the largest
single center experience worldwide. One hundred twenty-three consecutive patients underwent laparoscopic pancreatic surgery
from April 1998 to April 2007, 20 patients with cysts or pseudocysts for acute and chronic pancreatitis, laparoscopic pancreatic
drainage was performed, and were excluded from the analysis. The 103 patients were divided based on preoperative diagnosis:
group I, inflammatory tumors for chronic pancreatitis (eight patients); group II, cystic pancreatic neoplasms (29 patients);
group III, intraductal papillary mucinous neoplasms (10 patients); group IV, neuroendocrine pancreatic tumors (NETs) (43 patients);
and group V ductal adenocarcinoma (13 patients). The median tumor size was 5.3 cm. Pathologic data include R
0 or R
1 resection (transection margins on the specimen were inked). Perioperative data, postoperative complications, and resection
modalities were compared using statistical analysis. Long-term outcomes were analysed by tumor recurrence and patient survival.
The overall conversion rate was 7%. Laparoscopic distal pancreatic resection was performed in 82 patients (79.6%). Laparoscopic
spleen-preserving distal pancreatectomy (Lap SPDP) was performed in 52 patients (63.7%), but with splenic vessels preservation
in 22% and without splenic vessels preservation in 41.5%. Laparoscopic en-bloc splenopancreatectomy (Lap SxDP) was performed
in 30 patients (36.6%) and laparoscopic enucleation (Lap En) in 20 patients (19.4%). There was no mortality. The overall complication
rate was 25.2, 16.7, and 40% after Lap SPDP, Lap SxDP, and Lap En, respectively. The overall morbidity rate was significantly
higher (p > 0.05) in the group of Lap SPDP without splenic vessels preservation comparing with Lap SPDP with splenic vessels preservation
because of the occurrence of splenic complications (20.6%). The overall pancreatic fistulas was 7.7, 10, and 35% after Lap
SPDP, Lap SxDP, and Lap En, respectively; the severity of fistula was significantly higher in the Lap En group (p > 0.05). The mean hospital stay was within 1 week in all groups, except in the group of ductal adenocarcinoma, which is 8 days.
In this series, 27 patients (26.2%) had malignant disease. R
0 resection was achieved in 90% of ductal adenocarcinoma and 100% for other malignant tumors. The median survival for ductal
adenocarcinoma patients was 14 months. This series demonstrates that LPS is feasible and safe in benign-appearing and malignant
lesions of the pancreas. 相似文献
7.
Z. Levi R. Hazazi I. Kedar-Barnes E. Hodak E. Gal E. Mor Y. Niv J. Winkler 《American journal of transplantation》2007,7(2):476-479
Little is known about the effects of immunosuppression on patients with hereditary nonpolyposis colorectal cancer (HNPCC). We describe a kidney transplant recipient with unrecognized Muir-Torre syndrome in whom the administration of a tacrolimus-based regimen led to the eruption of multiple sebaceous tumors. The patient was later found to harbor an MSH2 mutation. Switching to a sirolimus-based regimen resulted in arrest of the disease. When the patient was switched back to tacrolimus, new facial lesions rapidly appeared. Switching again to sirolimus resulted again in halting the appearance of new lesions. This finding is in line with the known antiangiogenic activity of sirolimus and reports on the regression of cutaneous Kaposi's sarcoma in kidney transplant recipients switched from another immunosuppressive regimen to sirolimus. Further studies on the potential use of sirolimus for the treatment of de novo tumors in immunosuppressed kidney transplant recipients with HNPCC are warranted. 相似文献
8.
C Cislaghi E Negri C La Vecchia F Levi 《Revue d'épidémiologie et de santé publique》1990,38(3):237-243
A method of graphic representation of time factors in cancer mortality is presented, based on different tonalities of grey applied to the surface of the matrix defined by various age-specific rates. It is illustrated using mortality data from cancers of the mouth or pharynx, oesophagus, larynx and lung in Italian and Swiss males. Progressively more complex regression surface equations are defined, on the basis of two independent variables (age and cohort) and a dependent one (each age-specific rate). General patterns of trends were thus identified, showing important similarities in cohort and period effects, but also noticeable differences in time-related factors in mortality from various neoplasms of the upper digestive and respiratory tract. For instance, there were declines in mortality from cancers of the mouth or pharynx in the oldest age groups, whereas rates were appreciably upwards at younger and middle age, particularly in Italy. Likewise, cancers of the oesophagus and, chiefly, of the larynx were substantially increasing, on a cohort basis, in oldest Italian males. Temporal pattern for laryngeal cancer in Italy was similar to that of lung cancer, thus suggesting that (cigarette) smoking has a greater impact on this cancer site as compared with alcohol. However, it is difficult to explain, on this basis alone, the totally diverging pattern for cancer of the larynx (downwards) and of the lung (upwards) observed among older Swiss males. These examples indicate that trend surface models are a useful summary guide to illustrate and understand the general patterns of age, period and cohort effects in cancer mortality. 相似文献
9.
Mutated recombinant human heavy-chain ferritins and myelosuppression in vitro and in vivo: a link between ferritin ferroxidase activity and biological function. 总被引:5,自引:0,他引:5 下载免费PDF全文
H E Broxmeyer S Cooper S Levi P Arosio 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(3):770-774
Human heavy-chain (H-) ferritin muteins obtained by oligonucleotide site-directed mutagenesis, together with wild-type recombinant human H- and light-chain (L-) ferritins, were evaluated for in vitro effects on the suppression of human bone marrow myeloid progenitor cells and for in vivo effects on marrow and splenic myelopoiesis in C3H/HeJ mice. The 10 H-ferritin muteins exhibited alterations of various regions of the molecule, including ones exposed on the outer surface, on the inner cavity, and on the hydrophilic and hydrophobic channels and of the four-alpha-helix bundle forming the subunit structure. They were stable and were electrophoretically analogous to wild-type H-ferritin. The muteins showed in vitro and in vivo myelosuppressive activity analogous to wild type, except for mutein 222, which was totally inactive and which lacked ferroxidase activity. Recombinant human L-ferritin, devoid of ferroxidase activity, was also inactive as a suppressor. The results demonstrate that H-ferritin myelosuppressive and ferroxidase activities are linked. One possibility is that ferroxidase activity may interfere with the cellular uptake of transferrin iron that is needed for cell proliferation, an interpretation consistent with the presently described ability of hemin to overcome H-ferritin suppressive effects. 相似文献
10.