全文获取类型
收费全文 | 1886篇 |
免费 | 80篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 23篇 |
妇产科学 | 64篇 |
基础医学 | 138篇 |
口腔科学 | 52篇 |
临床医学 | 133篇 |
内科学 | 525篇 |
皮肤病学 | 39篇 |
神经病学 | 149篇 |
特种医学 | 57篇 |
外科学 | 449篇 |
综合类 | 2篇 |
预防医学 | 42篇 |
眼科学 | 25篇 |
药学 | 57篇 |
中国医学 | 2篇 |
肿瘤学 | 212篇 |
出版年
2023年 | 9篇 |
2022年 | 20篇 |
2021年 | 49篇 |
2020年 | 24篇 |
2019年 | 37篇 |
2018年 | 59篇 |
2017年 | 30篇 |
2016年 | 43篇 |
2015年 | 62篇 |
2014年 | 60篇 |
2013年 | 81篇 |
2012年 | 122篇 |
2011年 | 117篇 |
2010年 | 73篇 |
2009年 | 72篇 |
2008年 | 111篇 |
2007年 | 133篇 |
2006年 | 113篇 |
2005年 | 92篇 |
2004年 | 86篇 |
2003年 | 66篇 |
2002年 | 61篇 |
2001年 | 53篇 |
2000年 | 37篇 |
1999年 | 40篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 22篇 |
1991年 | 32篇 |
1990年 | 26篇 |
1989年 | 22篇 |
1988年 | 20篇 |
1987年 | 16篇 |
1986年 | 18篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1970年 | 4篇 |
1967年 | 5篇 |
排序方式: 共有1981条查询结果,搜索用时 15 毫秒
131.
132.
Alessandra Nicoletti MSc Pierfrancesco Pugliese MD Giuseppe Nicoletti MD Gennarina Arabia MSc Grazia Annesi PhD Michele De Mari MD Paolo Lamberti MD Lucia Grasso LLD Roberto Marconi MD Antonio Epifanio MD Letterio Morgante MD Autilia Cozzolino MD Paolo Barone MD Giusi Torchia TNFP Aldo Quattrone MD Mario Zappia MD 《Movement disorders》2010,25(14):2387-2394
We evaluated the possible association between smoking, coffee drinking, and alcohol consumption and Parkinson's disease (PD). The FRAGAMP study is a large Italian multicenter case–control study carried out to evaluate the possible role of environmental and genetic factors in PD. Adjusted ORs were estimated using unconditional logistic regression. Smoking, coffee, and alcohol consumption were also considered as surrogate markers of lifestyle and analysis was carried out considering the presence of at least one, two, or three factors. This latter analysis was separately performed considering Tremor‐Dominant (TD) and Akinetic‐Rigid (AR) patients. Four hundred ninety‐two PD patients (292 men and 200 women) and 459 controls (160 men and 299 women) were enrolled in the study. Multivariate analysis showed a significant negative association between PD and cigarette smoking (OR 0.51; 95%CI 0.36–0.72), coffee drinking (OR 0.61; 95%CI 0.43–0.87) and wine consumption (OR 0.62; 95%CI 0.44–0.86); a significant trend dose‐effect (P < 0.05) has been found for all the factors studied. We have also found a trend dose‐effect for the presence of at least one, two or three factors with a greater risk reduction (83%) for the presence of three factors. However, a different strength of association between TD and AR was found with a greater risk reduction for the AR patients. We found a significant inverse association between PD smoking, coffee, and alcohol consumption. When analysis was carried out considering the association of these factors as possible surrogate markers of a peculiar lifestyle the association was stronger for the AR phenotype. © 2010 Movement Disorder Society. 相似文献
133.
The role of statistics in medical research starts at the planning stage of a clinical trial or laboratory experiment to establish the design and size of an experiment that will ensure a good prospect of detecting effects of clinical or scientific interest. Statistics is again used during data analysis (sample data) to make inferences valid in a wider population. In simple situations, computation of simple quantities such as P-values, confidence intervals, standard deviations, standard errors or application of some standard parametric or nonparametric tests may suffice. Moreover, despite the wide use of statistics in medical research, simple notions are sometimes misunderstood or misinterpreted by medical research workers, who have only a limited knowledge of statistics. This article, written for non-statisticians, is to explain what are the most common statistical tests used today in the field of medical research, tracing the evolution of statistical tests over time, in particular the introduction of nonparametric methods and, more recently, the NonParametric Combination (NPC) methodology. At the same time, this work seeks to identify some of the errors associated with their use, that often lead to an incorrect assessment and interpretation of results of medical research. 相似文献
134.
Pinto F Sacco E Volpe A Gardi M Totaro A Calarco A Racioppi M Gulino G D'Addessi A Bassi PF 《Urologia》2010,77(2):92-99
Several substances such as growth hormone (GH), erythropoietin (Epo), and anabolic steroids (AS) are improperly utilized to increase the performance of athletes. Evaluating the potential cancer risk associated with doping agents is difficult since these drugs are often used at very high doses and in combination with other licit or illicit drugs. The GH, via its mediator, the insulin-like growth factor 1 (IGF-1), is involved in the development and progression of cancer. Animal studies suggested that high levels of GH/IGF-1 increase progression of androgen-independent prostate cancer. Clinical data regarding prostate cancer are mostly based on epidemiological studies or indirect data such as IGF-1 high levels in patients with prostate cancer. Even if experimental studies showed a correlation between Epo and cancer, no clinical data are currently available on cancer development related to Epo as a doping agent. Androgens are involved in prostate carcinogenesis modulating genes that regulate cell proliferation, apoptosis and angiogenesis. Most information on AS is anecdotal (case reports on prostate, kidney and testicular cancers). Prospective epidemiologic studies failed to support the hypothesis that circulating androgens are positively associated with prostate cancer risk. Currently, clinical and epidemiological studies supporting association between doping and urological neoplasias are not available. Nowadays, exposure to doping agents starts more prematurely with a consequent longer exposition period; drugs are often used at very high doses and in combination with other licit or illicit drugs. Due to all these elements it is impossible to predict all the side effects, including cancer; more detailed studies are therefore necessary. 相似文献
135.
Luigi D’Ambra Stefano Berti Pierfrancesco Bonfante Claudio Bianchi Daniela Gianquinto Emilio Falco 《World journal of surgery》2009,33(4):812-815
Background A new procedure of hemostasis during laparoscopic total mesorectal excision is described.
Methods In our surgical department, from January 2004 to December 2007, 128 patients underwent laparoscopic total mesorectal excision.
Among them, 47 patients underwent laparoscopic anterior resection after preoperative radiotherapy, 68 patients underwent laparoscopic
anterior resection without preoperative radiotherapy, and 13 patients underwent laparoscopic abdominal perineal amputation.
Results In seven laparoscopic rectal surgery cases, we encountered unstoppable presacral bleeding, not amenable by conventional hemostatic
solutions. In these cases we applied a simple staging hemostatic procedure. We first performed local compression: tamponing
with a small gauze or absorbable fabric hemostat. If bleeding did not stop, we localized an epiploic or omental scrap and
excised it by using bipolar forceps and use it as a plug on the tip of a grasping forceps. This plug is then put on the bleeding
source and monopolar coagulation is applied by electrified dissecting forceps through the interposed grasping forceps. If
bleeding did not stop, we used a little scrap of bovine pericardium graft and tacked it to the bleeding site using endoscopic
helicoidal protack.
Conclusions Our experience suggests that this hemostatic step-by-step procedure is a valid option to control persistent presacral hemorrhages. 相似文献
136.
Stefano Partelli M.D. Letizia Boninsegna M.D. Roberto Salvia M.D. Ph.D. Claudio Bassi M.D. Paolo Pederzoli M.D. Massimo Falconi M.D. 《American journal of surgery》2009,198(3):e49-e53
Background
The appropriate surgical approach of a pancreatic multifocal disease that skips the body of the gland remains unknown. We sought to analyze a parenchyma-sparing surgical technique consisting of a middle-preserving pancreatectomy (MPP) evaluating feasibility, safety, and oncological and functional outcomes.Patients and methods
Between 1999 and 2007, 5 patients affected by pancreatic benign or slow malignant multicentric body-sparing disease underwent MPP.Results
There were 3 men and 2 women with a median age of 35 years (range 28-70 years). The median operative time was 365 minutes (range 330-440 minutes). Postoperative mortality was nil and postoperative morbidity was 1 (20%). At a median follow-up of 20 months (range 14-118 months) all of the patients are alive and disease-free. Overall, 2 patients developed insulin-dependent diabetes mellitus, as well as exocrine insufficiency. One patient developed only exocrine insufficiency.Conclusions
MPP is a feasible procedure and might reduce the risk of both endocrine and exocrine insufficiency. 相似文献137.
Giuliano Barugola MD Stefano Partelli MD Stefano Marcucci MD Nora Sartori MD Paola Capelli MD Claudio Bassi MD Paolo Pederzoli MD Massimo Falconi MD 《Annals of surgical oncology》2009,16(12):3316-3322
Background
The 1-year disease-related mortality after resection for pancreatic cancer is approximately 30%. This study examined potential preoperative parameters that would help avoid unnecessary surgery. 相似文献138.
A. Vitale E. Gringeri A. Pauletto D. Bassi M. Polacco F. Russo C. Poci A. Romano 《Transplantation proceedings》2009,41(4):1096-1098
Background/Aim
The definition of an extended criteria donor for orthotopic liver transplantation (OLT) remains controversial. The donor risk index (DRI) has become the main tool to define the marginality of hepatic grafts in the United States. The aim of this study was to prospectively evaluate the prognostic ability of DRI among a cohort of Italian patients undergoing OLT.Methods
From December 2006 to March 2008, we prospectively calculated DRI in all consecutive cadaveric grafts. Recipient inclusion criteria were: adult patients with chronic liver disease enlisted for primary OLT. The primary end point was the incidence of primary graft dysfunction (PDF), namely, aspartate aminotransferase (AST) >2000 U/mL and prothrombin time <40% on postoperative days 2-7.Results
We enrolled 74 donor-recipient pairs fulfilling the inclusion criteria. Donor characteristics included DRI 1.7 (range, 0.9-3.0); age 57 years (range, 18-81); ultrasound signs of steatosis in 22 donors (30%); and ischemia time was 536 minutes (range, 290-690). Recipient characteristics are: age 55 years (range, 27-68); hepatocellular carcinoma in 36 subjects (49%); MELD was 16 (range, 7-39); and Child-Pugh score was 8 (range, 6-14). In terms of the primary end points, the DRI did not provide a significant PDF predictor (P = .84). Among all evaluated donor and recipient variables, the following were related to the incidence of graft PDF: donor age (P = .07), ultrasound signs of steatosis (P = .02), donor AST (P = .05), cell saver infusion (P = .07), and warm (P = .04) and cold ischemia (P = .07) times.Conclusion
The preliminary data of this study showed a poor correlation between DRI and PDF incidence after OLT. 相似文献139.
140.
Housing conditions change the emotional state of the animals. Ultrasound vocalizations (USVs) termed as 22 kHz are the usual components of the defensive responses of rats exposed to threatening conditions such as isolation. The amount of emission of 22 kHz USVs depends on the intensity of the aversive stimuli. While short periods of isolation caused an anxiolytic-sensitive enhancement of the defensive responses, long-term isolation tended to reduce the defensive performance of the animals to aversive stimuli. The dorsal periaqueductal gray (dPAG) is an important vocal center and a crucial structure for the expression of defensive response. While it has been shown that Substance P (SP) at this midbrain level is involved in the modulation of the defensive response, its role in the emission of ultrasound vocalizations has not been evaluated. In this study we examined whether the resocialization and local injections of SP into the dPAG have an influence on the isolation-induced 22 kHz USVs recorded within the frequency range of 18-26 kHz. Rats isolated for 1 day showed a significant increase in the number and duration of USVs, which were reversed by resocialization. On the other hand, 2-week isolation reduced the number and duration of 22 kHz USVs, which could not be reversed by resocialization. SP injections into the dPAG (35 pmol/0.2 microL) caused a reduction in the 22 kHz USVs. Pretreatment with the NK-1 receptor antagonist spantide (100 pmol/0.2 microL) blocked these effects but exhibited no effect when given alone. These findings suggest that 1-day and 2-week isolation recruit distinct brain defensive systems. Also, in agreement with the notion that intense fear is associated with the neural substrates of fear of the dPAG, activation of NK-1 receptors of this midbrain structure reduces the 22 kHz USVs. 相似文献