全文获取类型
收费全文 | 1782篇 |
免费 | 68篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 8篇 |
妇产科学 | 15篇 |
基础医学 | 320篇 |
口腔科学 | 54篇 |
临床医学 | 85篇 |
内科学 | 437篇 |
皮肤病学 | 24篇 |
神经病学 | 182篇 |
特种医学 | 121篇 |
外科学 | 165篇 |
综合类 | 9篇 |
预防医学 | 101篇 |
眼科学 | 44篇 |
药学 | 109篇 |
中国医学 | 2篇 |
肿瘤学 | 193篇 |
出版年
2023年 | 12篇 |
2022年 | 22篇 |
2021年 | 44篇 |
2020年 | 21篇 |
2019年 | 27篇 |
2018年 | 38篇 |
2017年 | 32篇 |
2016年 | 37篇 |
2015年 | 63篇 |
2014年 | 77篇 |
2013年 | 84篇 |
2012年 | 155篇 |
2011年 | 139篇 |
2010年 | 98篇 |
2009年 | 50篇 |
2008年 | 103篇 |
2007年 | 100篇 |
2006年 | 126篇 |
2005年 | 104篇 |
2004年 | 110篇 |
2003年 | 70篇 |
2002年 | 52篇 |
2001年 | 61篇 |
2000年 | 44篇 |
1999年 | 39篇 |
1998年 | 18篇 |
1997年 | 11篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 3篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1972年 | 6篇 |
1971年 | 3篇 |
1970年 | 3篇 |
排序方式: 共有1884条查询结果,搜索用时 15 毫秒
81.
Kim ST Won SY Kim SH Paik DJ Song WC Koh KS Kim HJ Hu KS 《The Journal of craniofacial surgery》2011,22(2):654-658
These cortical and trabecular bones maintain general bone structure. Bone mineral density (BMD) changes according to increasing age, sex, and teeth loss. From previous studies, the evaluation of BMD changes depended on conventional radiographic analysis. This study investigated the trabecular bone ratio (TBR) in maxillary bone samples based on data obtained by micro-computed tomography and estimated variations in BMD according to age, sex, and tooth loss. Thirty-eight specimens were scanned with micro-computed tomography and reconstructed three-dimensionally. Sections were made parallel to the axis of each tooth, and the TBR was measured. Data were statistically analyzed with 1-way analysis of variance and paired t-tests (α=0.05). The TBR differed significantly (P<0.05) in each tooth region in the dentate group but not in the edentulous group. The mean TBR was higher in men than in women. The TBR reduced more with increasing age in the dentate group than in the edentulous group. The TBR varies according to the presence of teeth, sex, and age in specific teeth regions. 相似文献
82.
OBJECTIVE: To assess the utilization rates of and complications associated with inpatient hysterectomy in California between 1991 and 2004. METHODS: We used the California Patient Discharge Database to analyze International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedure codes for 649,758 women undergoing inpatient hysterectomy in California between 1991 and 2004 using multiple logistic regression models. RESULTS: Between 1991 and 2004, the incidence of any type of inpatient hysterectomy for benign gynecologic conditions declined 17.6%. The rates of laparoscopically assisted vaginal hysterectomy and subtotal hysterectomy increased substantially. The year of hysterectomy was a factor associated with both medical and surgical complications; the odds of inpatient complications between 1991 and 2004 steadily declined. CONCLUSION: In California between 1991 and 2004, the incidence of inpatient hysterectomy for benign gynecological conditions and the adjusted odds of complications declined substantially. Changes in practice and shorter hospital stays may have affected the changes in inpatient hysterectomy rates and associated inpatient complications. 相似文献
83.
J.M. Kim C.H.D. Kwon J.-W. Joh J.B. Park J.H. Lee G.S. Kim S.J. Kim S.W. Paik S.-K. Lee 《Transplantation proceedings》2014
Liver transplantation (LT) is one of the few effective treatment options for hepatocellular carcinoma (HCC). Our aim in this study was to evaluate the risk factors for HCC recurrence and propose new criteria for LT based on pretransplantation findings. One hundred eighty patients who underwent LT for HCC between 2002 and 2008 were reviewed retrospectively. Outcome measures included maximal tumor size and number of tumors revealed by radiological studies before transplantation, demographics, and tumor recurrence. Maximal tumor size >6 cm, >7 tumors, and alpha-fetoprotein (AFP) levels >1000 ng/mL were identified as independent prognostic factors of HCC recurrence in univariate and multivariate analysis. Disease-free survival rate in patients with a maximal tumor size ≤6 cm, ≤7 tumors, and/or AFP levels ≤1000 ng/mL at 1, 3, and 5 years was 97.9%, 91.5%, and 90.0%, respectively, but the 1-, 3-, and 5-year disease-free survival rate of patients who had a maximal tumor size >6 cm, >7 tumors, and/or AFP levels >1000 ng/mL was 61.9%, 47.6%, and 47.6%, respectively (P < .001). In conclusion, LT can improve the survival of patients with advanced HCC if they have a maximal tumor size ≤6 cm, tumor number ≤7, and/or AFP levels ≤1000 ng/mL. 相似文献
84.
Chang TI Paik J Greene T Desai M Bech F Cheung AK Chertow GM 《Journal of the American Society of Nephrology : JASN》2011,22(8):1526-1533
Identifying potential modifiable risk factors to reduce the incidence of vascular access thrombosis in hemodialysis could reduce considerable morbidity and health care costs. We analyzed data from a subset of 1426 HEMO study subjects to determine whether more frequent intradialytic hypotension and/or lower predialysis systolic BP were associated with higher rates of vascular access thrombosis. Our primary outcome measure was episodes of vascular access thrombosis occurring within a given 6-month period during HEMO study follow-up. There were 2005 total episodes of vascular access thrombosis during a median 3.1 years of follow-up. The relative rate of thrombosis of native arteriovenous fistulas for the highest quartile of intradialytic hypotension was approximately twice that of the lowest quartile, independent of predialysis systolic BP and other covariates. There was no significant association of intradialytic hypotension with prosthetic arteriovenous graft thrombosis after multivariable adjustment. Higher predialysis systolic BP was associated with a lower rate of fistula and graft thrombosis, independent of intradialytic hypotension and other covariates. In conclusion, more frequent episodes of intradialytic hypotension and lower predialysis systolic BP associate with increased rates of vascular access thrombosis. These results underscore the importance of including vascular access patency in future studies of BP management in hemodialysis. 相似文献
85.
Cha JG Yoo JH Kim HK Park JM Paik SH Park SJ 《The British journal of radiology》2012,85(1012):e94-e98
Intra-osseous haemangioma is a rare, benign neoplasm that usually involves the vertebrae and craniofacial bones. Furthermore, its occurrence in the long bones is extremely rare. We report the findings of fluorine-18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT and MRI in a patient with intra-osseous haemangioma in the proximal tibia, who was initially misdiagnosed as having a malignancy based on (18)F-FDG PET/CT. (18)F-FDG PET/CT showed a well-marginated osteolytic lesion with abnormal FDG uptake. The mass demonstrated low signal intensity on T(1) weighted MRI. On T(2) weighted images, the lesion appeared as a cluster of high signal intensity lobules and showed strong enhancement on contrast-enhanced T(1) weighted images. Surgical curettage was performed and histopathological examination of the excised tissue confirmed a cavernous haemangioma. 相似文献
86.
87.
Quinone oxidoreductase (NQO1) plays a key role in the cellular antioxidant defense by detoxifying quinine derivatives. Case-control association study of the possible relationship between the NQO1 gene polymorphism and mood disorders (patients with major depressive disorder, n=61; patients with bipolar I disorder, n=80; control, n=106) was carried out using PCR-based techniques. These preliminary results showed that the NQO1 gene polymorphism was not related to a susceptibility to mood disorders. 相似文献
88.
Cisplatin exposure induces mitochondrial toxicity in pregnant rats and their fetuses. 总被引:2,自引:0,他引:2
M Gerschenson C Y Paik E L Gaukler B A Diwan M C Poirier 《Reproductive toxicology (Elmsford, N.Y.)》2001,15(5):525-531
High levels of cis-diamminedicholorplatinum II (cisplatin)-DNA adducts have previously been observed at term in mitochondrial DNA (mtDNA) from organs of pregnant rats, and from their offspring, after administration of a single injection of cisplatin 15 mg/kg body weight (bw) to the pregnant rat on day 18 of gestation. The consequences of such DNA damage may be clinically relevant as cisplatin is given to pregnant women discovered to have ovarian cancer during pregnancy. In this study, kidneys, livers, and brains of exposed pregnant rats and their offspring were examined for mitochondrial functional integrity. Consistent with previous literature, the most severe toxicity occurred in maternal kidney, where oxidative phosphorylation (OXPHOS) enzyme activities were significantly (approximately 50%) impaired for Complexes II, III, and IV, mtDNA levels in drug-exposed animals were higher than in the unexposed controls, and abnormal mitochondrial morphology was observed by transmission electron microscopy (TEM). In fetal kidneys and livers, cisplatin exposure did not alter mitochondrial morphology or mtDNA quantity, but specific activities of OXPHOS Complexes II and IV were significantly decreased. Fetal brain sustained no discernible mitochondrial toxicity. Therefore, cisplatin-induced mitochondrial toxicity in maternal rat kidney is severe, while damage to mitochondria in fetal kidney and liver, occurring as a result of the transplacental drug exposure, appears to be mild. 相似文献
89.
90.
Yoonjeong Jang Ah Young Lee Seung-Hee Chang Sang-Hee Jeong Kyung-Hun Park Min-Kyoung Paik 《Drug and chemical toxicology》2017,40(1):67-73
As the outermost layer of the body, the skin plays an important role in exposure to pesticides, which could have negative impacts on human health. Trifloxystrobin is a widely used fungicide of the strobilurin class, however, there is little information regarding the skin contact-associated toxic mechanism. Therefore, the present study was performed in order to identify the skin toxicity mechanism of trifloxystrobin using HaCaT (keratinocyte of human skin) cells. Following 24 or 48?h treatment, cell viability, and subsequent Annexin V-FITC/propidium iodide assay, TUNEL assay and Western blotting were performed to investigate the cell death mechanism of trifloxystrobin. Exposure to trifloxystrobin resulted in diminished viability of HaCaT cells in both a time- and concentration-dependent manner. The cell death was derived through apoptotic pathways in the HaCaT cells. Furthermore, we explored the effect of trifloxystrobin on TRAIL-mediated extrinsic apoptosis using siRNA transfection. Knockdown of death receptor 5 suppressed trifloxystrobin-provoked apoptosis. These results indicate that trifloxystrobin induces TRAIL-mediated apoptosis and has an inhibitory effect in keratinocytes that can interfere with the barrier function and integrity of the skin. This could be proposed as a mechanism of skin toxicity by trifloxystrobin and considered in the management of pesticide exposure. 相似文献