全文获取类型
收费全文 | 512篇 |
免费 | 20篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 25篇 |
妇产科学 | 5篇 |
基础医学 | 48篇 |
口腔科学 | 31篇 |
临床医学 | 32篇 |
内科学 | 100篇 |
皮肤病学 | 13篇 |
神经病学 | 9篇 |
特种医学 | 95篇 |
外科学 | 55篇 |
综合类 | 51篇 |
预防医学 | 25篇 |
眼科学 | 6篇 |
药学 | 41篇 |
肿瘤学 | 16篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 18篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 24篇 |
2009年 | 24篇 |
2008年 | 6篇 |
2007年 | 28篇 |
2006年 | 28篇 |
2005年 | 10篇 |
2004年 | 20篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 27篇 |
1997年 | 31篇 |
1996年 | 38篇 |
1995年 | 21篇 |
1994年 | 12篇 |
1993年 | 20篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 21篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1962年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有553条查询结果,搜索用时 15 毫秒
121.
Islam SS Edla SR Mujuru P Doyle EJ Ducatman AM 《American journal of preventive medicine》2003,25(1):31-37
BACKGROUND: The estimation of incidence and evaluation of risk factors associated with nonfatal occupational assault injuries have rarely been documented in a statewide population context. A state-managed workers' compensation system can provide estimates of incidence of such injuries and allow evaluation of risk factors. METHODS: Using claims data from the state-managed West Virginia Workers' Compensation, the incidence rates of workplace injuries resulting from physical assault were estimated for the period 1997-1999. Data on potential risk factors were obtained from the claim-related electronic data files, and the risk associated with each factor was assessed using proportional injury ratios (PIRs). RESULTS: During the study period, 2122 compensated injuries were associated with workplace violence. The incidence of assault injuries was 108.2 cases per 100,000 employee years. Women sustained a higher incidence than men. Healthcare workers, public safety workers, and teachers accounted for almost 75% of all assault injuries. Workers in these occupations also differed from each other with regard to seasonality and timing of assault, perpetrator-victim relationship, and types of injury. Evidence of gender-occupation interaction indicated higher risk of assault injury in men compared to women across the three leading occupations. Nighttime work shifts were associated with greater risk of assault for female healthcare workers (PIR=1.8; 95% confidence interval, 1.09-2.87). CONCLUSIONS: The healthcare sector sustained the bulk of assault injuries in West Virginia. Although the majority of healthcare-sector employees were women, the risk of assault injuries was higher in male employees. Risk factors and injury characteristics identified in this study, particularly for three high-risk occupations, should help develop strategies for preventing workplace violence. Protecting female healthcare workers on night-shift duty, especially in nursing home settings, appears to be an important target for intervention. 相似文献
122.
123.
124.
MP Busch ; JJ Korelitz ; SH Kleinman ; SR Lee ; JP AuBuchon ; GB Schreiber 《Transfusion》1995,35(11):903-910
BACKGROUND: Since the mid-1980s, blood banks in the United States have screened donors for elevated alanine aminotransferase (ALT) in an effort to prevent posttransfusion hepatitis. The present study was designed to quantitate the residual value of ALT screening following the implementation of hepatitis C virus (HCV) assays. STUDY DESIGN AND METHODS: Two approaches were used. First, a database of 2.3 million donations made by 586,507 volunteer blood donors between 1991 and 1993 was used to compare the incidence of seroconversion to hepatitis B virus (HBV) and HCV marker positivity in donors with elevated ALT values and with normal ALT values. Second, the duration of ALT elevation prior to HBV and HCV seroconversion was determined from 34 well-documented cases of posttransfusion HBV and HCV; elevated-ALT window periods were multiplied by rates of HBV and HCV incidence in donors to project the yield of ALT screening. Predictive value and cost- effectiveness analyses were also performed to compare the value of ALT screening before and after HCV screening was implemented. RESULTS: Both approaches indicate that ALT testing does not detect HBV in the window phase but does currently identify approximately 3 HCV window-phase donations per 1 million donations; this contrasts with ALT detection of approximately 1800 HCV-infectious units per 1 million donations prior to anti-HCV screening. Currently, only 8 in 10,000 donated units with elevated ALT (negative anti-HCV) are infected with HCV. The cost of continued ALT screening was estimated at $7,931,000 per quality- adjusted year of life saved. CONCLUSION: The yield, predictive value, and cost-effectiveness of ALT screening of blood donors have declined dramatically with the implementation of progressively improved anti-HCV assays. ALT screening of volunteer blood donors should be discontinued. 相似文献
125.
Increased detection of hepatitis C virus infection in commercial plasma donors by a third-generation screening assay 总被引:4,自引:0,他引:4
SR Lee ; CL Wood ; MJ Lane ; B Francis ; C Gust ; CM Higgs ; MJ Nelles ; A Polito ; R DiNello ; D Achord 《Transfusion》1995,35(10):845-849
BACKGROUND: Routine screening of blood donations with second-generation hepatitis hepatitis C virus (HCV) assays has substantially reduced the occurrence of posttransfusion hepatitis. However, following the development of third-generation assays, several studies indicated that these assays may identify HCV-infected individuals who are not identified by second-generation assays. STUDY DESIGN AND METHODS: The sensitivity of a third-generation HCV enzyme-linked immunosorbent assay (ELISA-3) was compared with a second-generation ELISA (ELISA-2) in a side-by-side study of 9936 commercial blood donors. ELISA-reactive specimens were subjected to supplemental analysis by third-generation recombinant immunoblot assay and polymerase chain reaction. RESULTS: ELISA-3 demonstrated greater sensitivity than ELISA-2, detecting 1 additional recombinant immunoblot assay-positive specimen per 2000 tested. ELISA-3 also detected 1 additional HCV-infectious polymerase chain reaction-positive unit among approximately 10,000 units screened. CONCLUSION: The incremental sensitivity achieved with ELISA-3 can be expected to eliminate approximately 20 infectious donations per week among those made by commercial donors in the United States. In accordance with previous studies, most of the improved sensitivity of ELISA-3 derives from its increased detection of anti-c33c (NS3), rather than from the inclusion of HCV antigen NS5. 相似文献
126.
S Sirrs EM Yoshida LTK Wong SR Erb SW Chung UP Steinbrecher CH Scudamore C Hartnett Y Lillquist AGF Davidson 《Paediatrics & child health》2003,8(8):497-498
A 15-year-old female with carbamyl phosphate synthetase deficiency, cystic fibrosis, and cystic fibrosis-related diabetes underwent orthotopic cadaveric liver transplantation. Metabolic control was maintained during the procedure with nutritional support and the use of intravenous sodium phenylacetate and benzoate. Her postoperative course was complicated by seizures and a transient decline in her pulmonary function tests, which returned to preoperative levels within one year of the transplant. Now, four years post-transplant, her quality of life has dramatically improved. There are only four Canadian centres with paediatric liver transplantation programs. However, expert medical care for adults with inborn error of metabolism is even more limited, suggesting that access to adult medical care is one of the many factors to be considered when liver transplantation is contemplated for patients with metabolically unstable conditions. 相似文献
127.
The acrosome reaction is an important marker for human sperm function.
Since different laboratory techniques may be used for the detection of this
exocytotic process, the purpose of the present study was to compare three
common markers [Pisum sativum agglutinin (PSA), concanavalin A (ConA),
double staining] and transmission electron microscopy for identification of
acrosomal changes. Preliminary findings had demonstrated that similar
results were achieved with Trypan Blue and Hoechst 33258 staining.
Therefore, supravital stainings were omitted. In various experiments, human
spermatozoa were treated with two concentrations (10 and 3.3 microM) of
calcium ionophore A23187 for 15, 30 and 60 min after capacitation for 3 and
6 h at 37 degrees C. The percentages of spermatozoa with acrosomal loss
detected by fluorescein isothiocyanate (FITC)-ConA were consistently lower
than those obtained by double staining or FITC-PSA, which showed comparable
results. Following 6 h of capacitation and incubation with 10 microM
ionophore for 1 h at 37 degrees C, 25.9 +/- 15.7% of all spermatozoa showed
almost complete loss of the acrosomal content. Binding of FITC- ConA to the
acrosomal region was observed in 27.0 +/- 13.2% of spermatozoa obtained
from the same sample. FITC-ConA and double staining or FITC-PSA detect
different stages of the acrosome reaction and may be helpful for a
differentiated evaluation of this sperm function.
相似文献
128.
129.
Doppman JL; Dedrick RL; Shook DR; Lutz RJ; Goldstein SR; Blacklock JB; Boretos JW; Paul RH; Austin HA d; Bowman RL 《Radiology》1986,159(2):477-483
Techniques have been developed for isolated perfusion of chemotherapeutic agents in patients with glioblastoma. Three catheters that facilitate crossing the carotid siphon have been developed; two are based on an everting or toposcopic principle, and one uses microjets for deflectability and improved mixing. Blood from the ipsilateral jugular vein is aspirated at high volumes (300 ml/min) for extracorporeal circulation through an adsorption column (for recovery of carmustine) or dialysers (for recovery of cisplatin). Preliminary experience in 10 patients suggests that high doses of chemotherapeutic agent can be administered using these catheters, with reduced retinal and systemic toxicity. 相似文献
130.