全文获取类型
收费全文 | 8633篇 |
免费 | 587篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 105篇 |
儿科学 | 295篇 |
妇产科学 | 291篇 |
基础医学 | 930篇 |
口腔科学 | 159篇 |
临床医学 | 930篇 |
内科学 | 1868篇 |
皮肤病学 | 215篇 |
神经病学 | 860篇 |
特种医学 | 227篇 |
外科学 | 1404篇 |
综合类 | 166篇 |
一般理论 | 3篇 |
预防医学 | 422篇 |
眼科学 | 136篇 |
药学 | 646篇 |
中国医学 | 72篇 |
肿瘤学 | 580篇 |
出版年
2023年 | 43篇 |
2022年 | 101篇 |
2021年 | 219篇 |
2020年 | 106篇 |
2019年 | 196篇 |
2018年 | 237篇 |
2017年 | 167篇 |
2016年 | 186篇 |
2015年 | 254篇 |
2014年 | 314篇 |
2013年 | 433篇 |
2012年 | 560篇 |
2011年 | 627篇 |
2010年 | 376篇 |
2009年 | 355篇 |
2008年 | 520篇 |
2007年 | 504篇 |
2006年 | 520篇 |
2005年 | 462篇 |
2004年 | 446篇 |
2003年 | 326篇 |
2002年 | 310篇 |
2001年 | 275篇 |
2000年 | 216篇 |
1999年 | 217篇 |
1998年 | 59篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 33篇 |
1994年 | 45篇 |
1993年 | 44篇 |
1992年 | 100篇 |
1991年 | 102篇 |
1990年 | 104篇 |
1989年 | 97篇 |
1988年 | 80篇 |
1987年 | 71篇 |
1986年 | 58篇 |
1985年 | 56篇 |
1984年 | 54篇 |
1983年 | 37篇 |
1982年 | 16篇 |
1981年 | 25篇 |
1980年 | 20篇 |
1979年 | 40篇 |
1978年 | 23篇 |
1977年 | 20篇 |
1976年 | 23篇 |
1975年 | 19篇 |
1974年 | 23篇 |
排序方式: 共有9309条查询结果,搜索用时 0 毫秒
61.
Huili Li Katherine B. Chiappinelli Angela A. Guzzetta Hariharan Easwaran Ray-Whay Chiu Yen Rajita Vatapalli Michael J. Topper Jianjun Luo Roisin M. Connolly Nilofer S. Azad Vered Stearns Drew M. Pardoll Nancy Davidson Peter A. Jones Dennis J. Slamon Stephen B. Baylin Cynthia A. Zahnow Nita Ahuja 《Oncotarget》2014,5(3):587-598
Epigenetic therapy is emerging as a potential therapy for solid tumors. To investigate its mechanism of action, we performed integrative expression and methylation analysis of 63 cancer cell lines (breast, colorectal, and ovarian) after treatment with the DNA methyltransferase inhibitor 5-azacitidine (AZA). Gene Set Enrichment Analysis demonstrated significant enrichment for immunomodulatory pathways in all three cancers (14.4-31.3%) including interferon signaling, antigen processing and presentation, and cytokines/chemokines. Strong upregulation of cancer testis antigens was also observed. An AZA IMmune gene set (AIMs) derived from the union of these immunomodulatory pathway genes classified primary tumors from all three types into “high” and “low” AIM gene expression subsets in tumor expression data from both TCGA and GEO. Samples from selected patient biopsies showed upregulation of AIM genes after treatment with epigenetic therapy. These results point to a broad immune stimulatory role for DNA demethylating drugs in multiple cancers. 相似文献
62.
Seven new compounds, O-trans-cinnamoylglutinol (1), 22β-hydroxy-12-oleanen-3-one (2), 15α,16α-epoxy-12-oleanen-3-one (3), 29-hydroxy-12-oleanene-3,22-dione (4), 22β,29-dihyroxy-12-oleanen-3-one (5), 2,3-(methylenedioxy)-4-methoxy-5-methylphenol (8), and 2,3,6-trimethoxy-5-methylphenol (9), as well as two first isolated from natural sources, 25-cycloartene-3,24-dione (6) and 24ξ-hydroxy-25-cycloarten-3-one (7), were characterized from Derris laxiflora. The structures of these compounds were determined by analysis of their spectroscopic data. 相似文献
63.
Postnatal management and long-term outcome for survivors with congenital diaphragmatic hernia 总被引:1,自引:0,他引:1
Significant advances in the postnatal management of patients with congenital diaphragmatic hernia (CDH) have resulted in a remarkable improvement in survival rates over the past two decades. The success of current postnatal management of CDH patients has rendered fetal intervention to be limited to the most severe cases, and the role for prenatal treatment of CDH patients remains unclear. The adoption of lung-preserving strategies including high-frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) have improved CDH outcomes especially in those patients with significant ventilatory or circulatory compromise. Survival rates of up to 90% are being reported in some high-volume centers. However, the increased survival in CDH patients has been accompanied by an increase in neurological, nutritional and musculoskeletal morbidity among the long-term survivors. This has resulted in the need to provide resources for the long-term follow-up and support of this patient population. In this article, the postnatal management strategies and primary and secondary outcomes of high-volume international pediatric surgical centers will be reviewed. Finally, the role of a multidisciplinary management team for the follow-up of long-term CDH survivors will be discussed. 相似文献
64.
65.
Lingbo Wang Michael Crennan Angela Benic Derek Chiu Fiona Morris Denise E. Jackson 《Transfusion medicine and hemotherapy : offizielles Organ der Deutschen Gesellschaft fur Transfusionsmedizin und Immunhamatologie》2022,49(3):180
IntroductionThe Bombay phenotype is a rare blood group determined by the absence of H antigens. Bombay individuals produce anti-H, a clinically significant antibody that react against all ABO blood group. Anti-H can mask underlying alloantibody during antibody investigation, a challenge in current transfusion practice. The aim of this article is to explore saliva inhibition, a novel method to detect underlying alloantibody in Bombay individuals.Case PresentationThe case is a 93-year-old female transfused with pre-donated autologous blood for a surgery. We determined anti-H subclass and thermal amplitude, secretor status, and optimal ratio of saliva and Bombay plasma. Plasma samples containing anti-H were spiked with anti-Fy(a) to determine the effectiveness of saliva inhibition in uncovering underlying alloantibodies.ResultsAnti-H was confirmed to be predominately IgM with broad thermal amplitude. Tube immediate spin (IS) showed stronger anti-H reactivity compared to column agglutination technology (CAT). Spiked anti-Fy(a) was successfully detected using saliva inhibition method.ConclusionTube IS appears more sensitive to anti-H. Saliva inhibition appears to be a promising method to detect underlying alloantibody in the plasma of Bombay phenotype individuals. 相似文献
66.
Background: Nutrition and inflammation have been implicated in predicting mortality in patients on peritoneal dialysis (PD). Serum albumin and globulin can be regarded for the nutritional and inflammatory status. However, there is lack of data to evaluate the synergistic effect of albumin and globulin on mortality prediction. Methods: In 554 patients initiating PD from January 2001 to July 2016, we divided them into four groups by the combination of two categories of low vs. high albumin and low vs. high globulin. The median values for albumin and globulin were chosen to classify them into low or high groups. Their associations with all-cause and cardiovascular (CV) mortality were examined in Cox regression models adjusted for confounding clinical and laboratory data. Results: Patients, 52.91 ± 15.2 years old and 47.8% men, had a median (interquartile range) value of 3.3 (2.9–3.8) g/dL for albumin and 2.8 (2.5–3.2) g/dL for globulin, respectively. Patients with low albumin and high globulin had the highest all-cause mortality and CV mortality, with adjusted hazard ratios of 3.87 (95% CI 1.83–8.20, p < 0.001) and 5.65 (95% CI 2.23–14.34, p < 0.001), respectively, compared with those with a high albumin and low globulin having the lowest mortality rate. Sensitivity analyses further confirmed this relationship. Conclusions: A patient profile of either low albumin or high globulin is linked to a higher risk for mortality, particularly for a profile of both low albumin and high globulin compared with one without either of them. Further studies are needed to explore the mechanisms underlying this phenomenon and how to improve clinical outcomes in those high-risk patients. 相似文献
67.
OBJECTIVE: To compare two newly designed flexible ureteroscopes with their respective predecessors, to determine whether design advances have overcome the limitation of tip deflection, which may interfere with diagnosis and treatment of lower pole renal pathology. MATERIALS AND METHODS: Two new-generation flexible ureteroscopes, the DUR-8 Elite (ACMI, Southborough, MA, USA) and 11278AU (Karl Storz Endoscopy, Culver City, CA, USA) were compared with their previous models, the ACMI DUR-8 and the Storz 11274AAU. Active tip deflection and irrigation flow rates with and without various endoscopic tools were assessed. Specifications, purchase prices and repair costs were obtained from each manufacturer. The field of view and screen image size of each ureteroscope were also compared. RESULTS: The ACMI DUR-8 Elite and the Storz 11278AU had improvements of 79 degrees and 144 degrees, respectively, from their respective older models. Although the tip deflection of all ureteroscopes was compromised by inserting different endoscopic tools, these new instruments were less affected. With a 3 F basket inside the working channel, the ACMI DUR-8 Elite and the Storz 11278AU had only 0.7% and 2.8% loss of upward tip deflection, compared with their older models, at 9.6% and 5.0%, respectively. However, the flow rates of these new instruments were decreased. CONCLUSION: The new flexible ureteroscopes have significantly better active tip deflection than previous models, both with and without endoscopic instrumentation inserted. However, improved flexibility is at the expense of decreased flow rates and higher purchase costs. 相似文献
68.
Shih-Hung Yang Nai-Jung Chiang Sz-Chi Chiu Wen-Chi Chou Li-Yuan Bai Chung-Pin Li Yung-Yeh Su Tai-Jan Chiu Shih-Chang Chuang Cheng-Ming Peng De-Chuan Chan Jen-Shi Chen Chia-Jui Yen Yen-Yang Chen Chang-Fang Chiu Li-Tzong Chen Yan-Shen Shan 《American journal of cancer research》2022,12(4):1884
Nanoliposomal irinotecan (nal-IRI) plus 5-fluorouracil and leucovorin (NalFL) comprises the current standard for gemcitabine-failed metastatic pancreatic ductal adenocarcinoma (PDAC). As liposomes generally accumulate in the spleen, we evaluated the impact of spleen volume on prognosis. We enrolled patients with metastatic PDAC who failed gemcitabine-based therapy and were initiated on NalFL between August 2018 and November 2020. The spleen volume before NalFL administration was evaluated. They were stratified into dose subgroups (i.e. low, < 48 mg/m2; intermediate, 48 - < 64 mg/m2; high, ≥ 64 mg/m2) by the average nal-IRI dose during the entire treatment, and multivariate analysis of overall survival (OS) was performed. We included 547 patients with a median age of 63 years (range, 27-89 years) and a median of 1 (range, 0-7) palliative chemotherapy regimen. The median spleen volume was 245 mL (range, 82-817 mL). Among patients with splenomegaly (≥ 245 mL), the low-dose subgroup had the worst median time to treatment failure (TTF, 1.8 months vs. 2.5 months vs. 2.5 months, P = 0.020) and OS (3.3 months vs. 5.9 months vs. 6.6 months, P = 0.018) as against no prognostic impact in patients without splenomegaly. In the multivariate analysis of patients with splenomegaly, performance status (PS) ≥ 2, body surface area (BSA) < 1.6 m2, prior fluoropyrimidine use, liver metastasis, and low-dose subgroup were independent poor prognostic factors. A low average nal-IRI dose was significantly associated with poor prognosis, especially among patients with splenomegaly. Further pharmacological studies should validate the relevance of spleen volume on the treatment outcomes of nal-IRI. 相似文献
69.
Substantial in vitro and in vivo evidence of neurotrophic and neuroprotective effects of lithium suggests that it may also have considerable potential for the treatment of neurodegenerative conditions.Lithium's main mechanisms of action appear to stem from its ability to inhibit glycogen synthase kinase-3 activity and also to induce signaling mediated by brain-derived neurotrophic factor.This in turn alters a wide variety of downstream effectors,with the ultimate effect of enhancing pathways to cell surviva... 相似文献
70.
ABSTRACT: BACKGROUND: AMP-activated protein kinase (AMPK) has recently been considered as a potential target for cancer therapy. However, the expression status of various subunits of the heterotrimeric AMPK in human cancers is rarely reported. We decided to determine their expressions in ovarian carcinomas and their relationships with the disease. METHODS: Expressions and locations of the AMPK-alpha1, -alpha2, -beta1, -beta2, -gamma1 and -gamma2 were detected by quantitative PCR (Q-PCR) and immunohistochemical staining (IHC). Their expression levels in ovarian tumors were compared with normal controls and also correlated with clinicopathological parameters. RESULTS: Except AMPK-alpha1, expressions of the other five AMPK subunits are significantly higher in ovarian carcinomas as determined by Q-PCR. Although IHC detection of AMPK-gamma1 and -gamma2 were not successful, over-expressions of AMPK-alpha2, -beta1, and -beta2 were further confirmed by IHC. Over-expressions of various AMPK subunits occurred independently and were mainly detected in the cytoplasm. Interestingly, AMPK-alpha2 and -beta1 were also detected in the nucleus and cell membrane, respectively. Clinical correlation analyses indicate that expressions of different AMPK subunits are associated with different subtypes of carcinoma. High expression of AMPK-alpha2 is significantly associated with endometrioid carcinomas. On the other hand, high expressions of AMPK-beta and -gamma subunits are associated with mucinous and serous carcinomas, respectively. Furthermore, high expressions of AMPK-beta1 and -gamma2 are also associated with early and late stages of disease, respectively. Finally, patients with high expression of AMPK-alpha2 had better prognosis. CONCLUSIONS: Aberrant expressions of AMPK subunits may play important roles in ovarian carcinogenesis. Each AMPK subunit may have its own function other than just a component of the AMPK molecule. Correlations with clinical parameters suggest that expressions of AMPK subunits have different clinical implications in ovarian cancer development. 相似文献