全文获取类型
收费全文 | 6769篇 |
免费 | 376篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 148篇 |
妇产科学 | 183篇 |
基础医学 | 964篇 |
口腔科学 | 492篇 |
临床医学 | 410篇 |
内科学 | 1585篇 |
皮肤病学 | 96篇 |
神经病学 | 680篇 |
特种医学 | 140篇 |
外科学 | 995篇 |
综合类 | 42篇 |
一般理论 | 3篇 |
预防医学 | 445篇 |
眼科学 | 183篇 |
药学 | 332篇 |
中国医学 | 38篇 |
肿瘤学 | 374篇 |
出版年
2023年 | 58篇 |
2022年 | 144篇 |
2021年 | 307篇 |
2020年 | 168篇 |
2019年 | 233篇 |
2018年 | 251篇 |
2017年 | 141篇 |
2016年 | 161篇 |
2015年 | 242篇 |
2014年 | 324篇 |
2013年 | 408篇 |
2012年 | 548篇 |
2011年 | 648篇 |
2010年 | 317篇 |
2009年 | 288篇 |
2008年 | 489篇 |
2007年 | 433篇 |
2006年 | 463篇 |
2005年 | 385篇 |
2004年 | 331篇 |
2003年 | 277篇 |
2002年 | 239篇 |
2001年 | 24篇 |
2000年 | 22篇 |
1999年 | 19篇 |
1998年 | 35篇 |
1997年 | 24篇 |
1996年 | 23篇 |
1995年 | 16篇 |
1994年 | 16篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1971年 | 5篇 |
1961年 | 3篇 |
1912年 | 3篇 |
排序方式: 共有7176条查询结果,搜索用时 15 毫秒
41.
José Antonio López-Moreno María Scherma Fernando Rodríguez de Fonseca Gustavo González-Cuevas Walter Fratta Miguel Navarro 《Neuroscience letters》2008
Alcohol, nicotine, and cannabinoid acutely increase the activity of the mesolimbic dopamine (DA) pathway. Although polysubstance consumption is a common pattern of abuse in humans, little is known about dopamine release following pre-exposure to these drugs. The purpose of this study was to test whether alcohol-induced dopamine release into the nucleus accumbens (NAc) shell is modified by different pre-treatments: water (i.g.), alcohol (1 g/kg, i.g.), nicotine (0.4 mg/kg, s.c.), and WIN 55,212-2 (1 mg/kg, s.c.). Male Wistar rats were treated (i.g.) for 14 days with either water or alcohol. In the following 5 days rats were injected (s.c.) with vehicle, nicotine, or WIN 55,212-2. Finally, a cannula was surgically implanted into the NAc shell and alcohol-induced extracellular dopamine release was monitored in freely moving rats. Alcohol (1 g/kg; i.g.) only increased the release of dopamine when animals were previously treated with water. This DA increase was markedly inhibited by (subchronic) treatment (5 days) with nicotine or WIN 55-212-2 as well as by previous (chronic) exposure to alcohol (14 days). These data demonstrate that pre-treatment with nicotine and the cannabinoid agonist WIN 55,212-2 is able to change the sensitivity of the NAc shell in response to a moderate dose of alcohol. Therefore, cannabinoid and nicotine exposure may have important implications on the rewarding effects of alcohol, because these drugs lead to long-lasting changes in accumbal dopamine transmission. 相似文献
42.
Schewe C Goldmann T Grosser M Zink A Schlüns K Pahl S Ulrichs T Kaufmann SH Nerlich A Baretton GB Dietel M Vollmer E Petersen I 《Virchows Archiv : an international journal of pathology》2005,447(3):573-585
The present study is based on the initiative for quality assurance in pathology of the German Society of Pathology and the Professional Association of German Pathologists. Four panel laboratories with experience and expertise in polymerase chain reaction (PCR) detection of Mycobacterium tuberculosis were selected to establish the prerequisites for continuous external laboratory trials, in particular, by providing pre-tested specimens and evaluation criteria for participating institutes. In the first step, the four panel laboratories performed an internal trial to test their own reliability and reproducibility. Paraffin sections and DNA preparations from 34 tissues (25 clinical specimens and 9 controls) totalling to 66 samples were evaluated by each panel institute according to their own protocols. The methodologies differed and are described in detail. Despite these differences, a high degree of inter-laboratory reliability was achieved. In this report, we summarise our results including the correlation with the histology and provide recommendations for applying PCR-based methodology for the detection of mycobacterial DNA in surgical specimens. Supplementary data are available online at (rubric Forschung). Pre-tested specimens are now available for the external trial and can be ordered from the steering institute via Oligene (). All molecular pathology laboratories are invited to participate in this quality assurance initiative. 相似文献
43.
Regulation of hepatocyte activator inhibitor-1 expression by androgen and oncogenic transformation in the prostate
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Knudsen BS Lucas JM Fazli L Hawley S Falcon S Coleman IM Martin DB Xu C True LD Gleave ME Nelson PS Ayala GE 《The American journal of pathology》2005,167(1):255-266
Hepatocyte activator inhibitor-1 (HAI-1) is a transmembrane serine protease inhibitor that regulates the conversion of latent to active hepatocyte growth factor (HGF). Studies supporting a role for the HGF pathway in prostate carcinogenesis prompted an analysis of HAI-1 expression in the prostate. Here we analyze the regulation of HAI-1 expression by androgen, oncogenic transformation, and cancer progression. Immunohistochemical analysis revealed that HAI-1 expression was restricted to prostate epithelium, where staining occurred primarily in basal and atrophic luminal epithelial cells. Compared to normal glands, HAI-1 expression was significantly increased in localized prostate cancer and was present in most prostate cancer metastases. HAI-1 protein expression levels were sensitive to androgen in normal epithelium but not in cancer. Although androgen did not increase HAI-1 protein expression levels in LNCaP cells, it decreased HAI-1 surface expression, consistent with previous data from our group (Martin DB, Gifford DR, Wright ME, Keller A, Yi E, Goodlett DR, Aebersold R, Nelson PS: Quantitative proteomic analysis of proteins released by neoplastic prostate epithelium. Cancer Res 2004, 64:347-355). HAI-1 overexpression in cancer was predictive of prostate-specific antigen recurrence (relative risk, 1.24). These results suggest that HAI-1 regulates the HGF Met axis on prostate epithelial cells and influences HGF mediated tumor invasion and metastasis. 相似文献
44.
Luque-Reca Octavio Soriano-Maldonado Alberto Gavilán-Carrera Blanca Acosta-Manzano Pedro Ariza-Vega Patrocinio del Paso Gustavo A. Reyes Álvarez-Gallardo Inmaculada C. Estévez-López Fernando 《Quality of life research》2022,31(7):2059-2059
Quality of Life Research - 相似文献
45.
Francisca de Castro Mendes Kirstie Ducharme-Smith Gustavo Mora-Garcia Saleh A. Alqahtani Maria Stephany Ruiz-Diaz Andre Moreira Rodrigo Villegas Vanessa Garcia-Larsen 《Nutrients》2021,13(6)
Increasing epidemiological evidence suggests that optimal diet quality helps to improve preservation of lung function and to reduce chronic obstructive pulmonary disease (COPD) risk, but no study has investigated the association of food insecurity (FI) and lung health in the general population. Using data from a representative sample of US adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2012 cycles, we investigated the association between FI with lung function and spirometrically defined COPD in 12,469 individuals aged ≥ 18 years of age. FI (high vs. low) was defined using the US Department of Agriculture’s Food Security Scale). Population-weighted adjusted regression models were used to investigate associations between FI, and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), their ratio, and spirometrically defined restriction (FVC below the lower limit of normal) and airflow obstruction (COPD). The prevalence of household FI was 13.2%. High household FI was associated with lower FVC (adjusted β-coefficient −70.9 mL, 95% CI −116.6, −25.3), and with higher odds (OR) of spirometric restriction (1.02, 95% CI 1.00, 1.03). Stratified analyses showed similar effect sizes within specific ethnic groups. High FI was associated with worse lung health in a nationally representative sample of adults in the US. 相似文献
46.
Martínez-Pérez Rafael Silveira-Bertazzo Giuliano Rangel Gustavo G. Albiña Pablo Hardesty Douglas Carrau Ricardo L. Prevedello Daniel M. 《Neurosurgical review》2021,44(1):51-60
Neurosurgical Review - The current literature regarding surgical treatment for tumors in the sphenopetroclival (SPC) region is merely scarce. Through a comprehensive literature review, we... 相似文献
47.
Jason Talevski Kerrie M Sanders Ljoudmila Busija Alison Beauchamp Gustavo Duque Fredrik Borgström John A Kanis Axel Svedbom Catherine Connaughton Amanda L Stuart Sharon L Brennan-Olsen 《Journal of bone and mineral research》2021,36(2):252-261
Major osteoporotic fractures (MOFs) are associated with a rapid decline in health-related quality of life (HRQoL); however, there is limited knowledge about which healthcare services positively affect HRQoL postfracture. This study aimed to identify specific combinations of health service use associated with recovery of HRQoL 12 months post-MOF. The analyses included 4126 adults aged ≥50 years with an MOF (1657 hip, 1354 distal forearm, 681 vertebrae, 434 humerus) participating in the International Costs and Utilities Related to Osteoporotic fractures Study (ICUROS), a multinational observational study (Australia, Austria, Estonia, France, Italy, Lithuania, Mexico, Russia, Spain, United Kingdom, and United States). HRQoL at prefracture and 12 months postfracture was measured using the EuroQoL questionnaire (EQ-5D-3L). Health service use data were collected via participant interviews and medical record reviews including in-hospital care; outpatient care; community services; and medication use. Data analyses involved two stages: (i) latent class analyses to identify different combinations of health service use (“classes”); and (ii) logistic regression to assess effects of classes on HRQoL recovery. Analyses were repeated excluding hip fractures (non-hip MOFs). Overall, 2057 MOF participants (49.9%) recovered to their prefracture HRQoL at 12-month follow-up; this proportion was higher for non-hip MOFs (n = 1439; 58.3%). Several distinct classes were identified across countries (range, 2–5 classes). Classes that were associated with increased odds of HRQoL recovery were characterized by a combination of hospital presentations without admission; outpatient department visits; allied health visits; vitamin D/calcium supplementation; and/or non-opioid analgesic use. Similar classes were observed for non-hip MOFs. Understanding country-specific healthcare service pathways that influence greater recovery of HRQoL, particularly services that are uncommon in some countries and routine in others, could improve postfracture care on a global scale. © 2020 American Society for Bone and Mineral Research (ASBMR). 相似文献
48.
Rafael Lucas Costa de Carvalho Miguel Lia Tedde Jose Ribas Milanese de Campos Niura Noro Hamilton Gustavo Falavigna Guilherme Vanessa Moreira Sousa Vitor Floriano Salomao Junior Flavio Henrique Savazzi Paulo Manuel Pego-Fernandes 《Journal of pediatric surgery》2021,56(3):545-549
Background/PurposeThe aim of the study was to evaluate the postoperative quality of life (QoL) of patients who underwent minimally invasive repair of pectus excavatum (MIRPE) with a newly designed bar and bar stabilizers.MethodsWe conducted a prospective randomized study in which patients were operated either with standard perpendicular stabilizers (control group) or with the newly designed oblique stabilizers (intervention group). All patients were evaluated 6 months after the operation with the Pectus Excavatum Evaluation Questionnaire (PEEQ).ResultsThere were 16 patients in the control group and 14 in the intervention group. Mean age was 17 (SD: 3.3, range 14–27) years. There were no demographic differences between groups. Two patients in the control group and one in the intervention group were repaired with two bars instead of one. There was one reoperation in each group. There was a significant difference between the pre- and postoperative scores, in both groups, in the patient body image domain (control group: 9.5 to 3; p < 0.01; intervention group 10 to 3; p < 0.01), as well as in the psychosocial domain (control group: 13.5 to 24, p < 0.01; intervention group: 15 to 24, p < 0.01). With regards to the patients' perception of physical difficulties before and after MIRPE, the difference between pre- and postoperative scores was greater in the intervention group (8 to 12, p < 0.01) than in the control group (10 to 11, p = 0.04). The mean length of stay was 4.5 and 5 days in the intervention group and the control group, respectively.ConclusionOur study showed that patients who underwent MIRPE with the newly designed bars and stabilizers had non-inferior outcomes than patients reported in the literature who underwent MIRPE with standard bars and stabilizers. We found slightly better outcomes in patients in the intervention group compared to the control group, but larger studies will be needed to confirm if those differences are statistically significant.Level of evidenceII 相似文献
49.
André Luís Conde Watanabe Mateus Silva Feijó Vinícius Paulo Lima de Menezes Mayara Regina Galdino-Vasconcelos Jorge Luis Salinas Caballero Gustavo Ferreira Fernando Jorge Natália Trevizoli Luiz Gustavo Diaz Priscila Brizolla de Campos Gabriel Cajá Raquel Ullmann Ana Virgínia Figueira Tiago Morato Adriano Moraes Juan Rafael Branez Pereira Marcelo Perosa 《Transplantation proceedings》2021,53(1):73-82
IntroductionLiver transplantation is the standard treatment for end-stage liver disease. Brazil holds the third highest number of liver transplants performed per year, but center maldistribution results in high discrepancies in accessing this treatment. In 2012, an interstate partnership successfully implemented a new liver transplantation program in the middle west of Brazil. Here, we report the results of the first 500 liver transplants performed in this new program and discuss the impacts of a new transplant center in regional transplantation dynamics.MethodsWe reviewed data from the first 500 consecutive deceased donor liver transplants performed in the new program during an 8-year period. We analyzed data on patients’ clinical and demographic profiles, postoperative outcomes, and graft and recipient survival rates. Univariate survival analysis was conducted using log-rank tests to compare the groups.ResultsAlmost half (48%) of the procured organs and 40% of the recipients transplanted in our center were from outside our state. Recipient 30-day mortality was 9%. Overall recipient survival at 1 year and 5 years was 85% and 80%, respectively. Mortality was significantly associated with higher Model for End-Stage Liver Disease (P < .001) but not with the presence of hepatocellular carcinoma (P = .795).DiscussionThe new transplantation program treated patients from different regions of Brazil and became the reference center in liver transplantation for the middle west region. Despite the recent implementation, our outcomes are comparable to experienced centers around the world. This model can inspire the creation of new transplantation programs aiming to democratize access to liver transplantation nationwide. 相似文献
50.
Gustavo Martinez-Mier Pedro I. Moreno-Ley Luis F. Budar-Fernández Marco T. Méndez-López Carlos A. Allende-Castellanos Luis A. Jiménez-López Daniel A. Barrera-Amoros Edgar Aguilar-Sandoval Maritza De la Paz-Román Ernesto Soto-Miranda Yamilli Rivera-Sanchez Mónica Martínez-Maldonado 《Transplantation proceedings》2021,53(3):1005-1009
ContextThymoglobulin is used effectively as induction agent in kidney transplantation but the optimal dose is not well established.ObjectiveDemonstrate that low-dose thymoglobulin (3 mg/kg) has similar efficacy and safety compared to basiliximab induction in low-risk kidney transplantation under standard maintenance immunosuppressionDesign, Setting, ParticipantsProspective randomized study in kidney transplant patients (12/2016-05/2018). Inclusion criteria: Recipients > 18 years, first living donor transplant. Exclusion criteria: Second and multiorgan transplant, ABO incompatibility, positive cross-match, panel reactive antibodies (PRA) > 30%, positive donor-specific antibody, human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus positive, white blood cells < 2000 cells/mm3, platelets < 75,000 cells/mm3 and malignancy.InterventionGroup A: basiliximab (20 mg D0 and D4). Group B: thymoglobulin (3 mg/kg total). Maintenance immunosuppression: tacrolimus, mycophenolate mofetil, and steroids.Main Outcome MeasuresBiopsy-proven acute rejection (BPAR), delayed graft function, slow graft function, leukopenia, infections, adverse events, graft loss, estimated glomerular filtration rate, and death within 12 months.Results100 patients (basiliximab, n = 53) (thymoglobulin, n = 47) were included. Donor and recipient characteristics were similar except for longer dialysis (basiliximab), PRA class I (1.2% basiliximab, 4.5% thymoglobulin), HLA match (basiliximab 2.8, thymoglobulin 2.2), and cytomegalovirus status. BPAR rate was basiliximab 3.8% and thymoglobulin 6.4% (P = ns). Delayed graft function (basiliximab 3.8%; thymoglobulin 4.3%), slow graft function, and 12-month leukopenia (basiliximab 11.3%, thymoglobulin 21.3%) were similar between groups (P = ns). There was no difference in infections and adverse events between groups. Patient and graft survival were as follows: basiliximab 98.1% and 92.5%, thymoglobulin 100% and 93.6% (P = ns).ConclusionLow-dose thymoglobulin induction (3 mg/kg) can be used effectively and safely in low-risk kidney transplantation with good results during the first year post-transplant. 相似文献