全文获取类型
收费全文 | 283篇 |
免费 | 23篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 12篇 |
妇产科学 | 3篇 |
基础医学 | 27篇 |
口腔科学 | 24篇 |
临床医学 | 33篇 |
内科学 | 64篇 |
皮肤病学 | 8篇 |
神经病学 | 4篇 |
特种医学 | 68篇 |
外科学 | 25篇 |
综合类 | 5篇 |
预防医学 | 14篇 |
眼科学 | 2篇 |
药学 | 4篇 |
肿瘤学 | 14篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 20篇 |
1997年 | 17篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 4篇 |
排序方式: 共有308条查询结果,搜索用时 15 毫秒
61.
鉴定γB-晶体蛋白非酶糖基化位点。方法用离子交换HPLC纯化小牛晶状体γB-晶体蛋白,与果糖保温后用糜蛋白酶水解。糖基化的肽用Affi-Gel601柱层析纯化,并用RP-HPLC分离各肽。 相似文献
62.
Bondanelli M; Ambrosio MR; Franceschetti P; Guerrini R; Valentini A; degli Uberti EC 《Human reproduction (Oxford, England)》1998,13(5):1159-1162
There is evidence that endogenous opioid peptides exert an inhibitory
effect on pituitary luteinizing hormone (LH) secretion both in animals and
in humans, by interacting with mu-opioid receptors. However, a role for
delta-opioid receptors in the regulation of gonadotrophin releasing hormone
(GnRH) secretion has recently been suggested. In the present study, we
evaluated the effect of the highly selective delta-opioid receptor agonist
deltorphin on the LH and follicle stimulating hormone (FSH) responses to
naloxone in six healthy fertile women during the luteal phase of the
menstrual cycle. Deltorphin infusion alone (7 microg/kg/min for 60 min) did
not significantly change the basal serum concentrations of LH in this group
of women. The intravenous (i.v.) bolus administration of naloxone (15 mg)
induced a significant (P < 0.001) increase in serum LH concentrations
(from a mean basal value of 4.24+/-1.10 IU/l to a peak of 13.27+/-1.8
IU/l). The LH response to naloxone was significantly (P < 0.001) blunted
by preinfusion of deltorphin (13.27+/- 1.80 IU/l versus 4.80+/-1.18 IU/l).
No significant changes in FSH concentrations were observed during
deltorphin, naloxone or deltorphin plus naloxone administration. These data
indicate that activation of delta-opioid receptors can reduce
naloxone-induced LH release, suggesting a possible role of delta receptors
in opioidergic modulation of LH secretion in women.
相似文献
63.
Low-oxygen-affinity red cells produced in a large-volume, continuous- flow electroporation system 总被引:1,自引:0,他引:1
BACKGROUND: Human red cells containing inositol hexaphosphate (IHP) have a lowered O2 affinity, though they are able to bind and carry about the same amount of oxygen as native cells. These modified cells therefore deliver oxygen more efficiently to the tissues, which is a property of potential clinical utility. Investigators set out to devise a system and procedure by which large volumes of IHP-containing red cells, suitable for transfusion, could be produced quickly and efficiently. STUDY DESIGN AND METHODS: The encapsulation of IHP into human red cells by use of several variations of static electroporation was performed to define the conditions necessary for optimal IHP incorporation and cell survival. These conditions were used as a starting point for optimization of a flow electroporation system. RESULTS: When fresh human red cells in a 35 mM IHP solution are subjected to three exponential pulses of field strength of 2.98 +/− 0.064 kV per cm per pulse and pulse length of 2.0 +/− 0.2 msec per pulse while flowing through a cooled electroporation chamber, the condition of the resultant cells, according to the criteria used here, is optimized. After storage for 24 hours in plasma at 37 degrees C, the cells show more than 85-percent survival (in vitro) and hematologic indices nearly identical to those of unpulsed control cells. The p50 value of these cells, however, has doubled to 50.4 +/− 2.0 torr. The processing time for 1 unit of blood is 90 minutes. CONCLUSION: These data indicate that the system described here can efficiently produce low-oxygen-affinity red cells in volumes that are useful in clinical applications. 相似文献
64.
J Farquharson EC Jamieson RW Logan MB McFadyen WJ Patrick AG Howatson F Cockburn 《Archives of disease in childhood》1998,79(1):28-32
Abnormal fetal and infant growth have increasingly been correlated with adult onset cardiovascular disease. To date, there is little known about the lipid fatty acid profiles in infant cardiovascular tissue. Therefore, we analysed total lipid fatty acids from thoracic and abdominal aorta intima and media from 24 normally grown sudden infant death syndrome cases. Aorta from small for gestational age (n = 2), failure to thrive from birth (n = 3), and premature (n = 1) infants were also examined. Dihomo-gamma-linolenic acid (C20:3n-6) and oleic acid (C18:1n-9) concentrations were significantly lower in the thoracic than in the abdominal aorta. Similar dietary related differences were found in the subgroup (n = 15) of infants fed on formula milks. Both abdominal and thoracic intimal arachidonic (C20:4n-6) to dihomo-gamma-linolenic acid ratios were greater in the infants with retarded growth after birth than in their normally grown counterparts. Growth restriction in infancy might disrupt the normal accretion of vascular endothelial polyunsaturated fatty acids. 相似文献
65.
R Booy SA Hodgson MP Slack EC Anderson RT Mayon-White ER Moxon 《Archives of disease in childhood》1993,69(2):225-228
For a seven year period (1985-91) clinical and epidemiological data were prospectively collected on children aged < 10 years with microbiologically confirmed invasive Haemophilus influenzae type b infection in the Oxford region to study the epidemiology of the disease and determine the potential impact of early primary immunisation in infants. Computer records of primary immunisations given to these cases were retrospectively analysed and, where necessary, hospital and general practitioner records were searched to determine the immunisation history. Over the seven year period, 416 cases of invasive H influenzae type b disease were reported. Widescale immunisation against H influenzae type b began in 1991 as part of a regional trial. The estimated annual incidence for invasive disease between 1985 and 1990 was 35.5 cases per 100,000 children aged less than 5 years; for H influenzae type b meningitis it was 25.1 per 100,000 children aged less than 5 years. The cumulative risks for invasive disease and meningitis by the fifth birthday were one in 560 and one in 800 respectively. The majority of disease (71%) occurred in children less than 2 years of age with the peak monthly incidences at 6 and 7 months of age. The overall mortality was 4.3% and 50% of these deaths occurred suddenly. Most (91%) of the children had received at least one primary immunisation against diphtheria, tetanus, and pertussis before H influenzae type b infection and there was only one case of parental refusal of immunisation. None had received H influenzae type b immunisation. Given a vaccine uptake of 90% by 5 months of age it is estimated that at least 82% of the H influenzae type b infections could have been prevented. Extrapolated nationally, 1150 cases of infection and 50 deaths could be prevented each year by routine primary immunisation. 相似文献
66.
Cordeiro R Lima Filho EC Salgado PE 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1996,12(4):455-463
We randomly selected twenty lead workers from an electric accumulator factory in the State of S?o Paulo, Brazil, whose blood lead level and urinary d-aminolevulinic acid level were below 60 mg/dL and 10 mg/L, respectively. The workers were submitted to a standard motor nerve conduction velocity study of the right radial nerves, in addition to blood lead dosage. Based on these measures, a first-order linear regression model was adjusted, where the dependent variable was conduction velocity and the independent variable was the blood lead level. Analyzing the fitted model, we inferred that the negative predictive value of the Brazilian biological exposure limit is 0.63. In order for the above biological exposure limit to have a negative predictive value of 0.99, the study suggests that it be reduced from its present value (60 mg/dL) to 32 mg/dL. 相似文献
67.
Masahiko Yazawa Orsolya Cseprekal Ryan A. Helmick Manish Talwar Vasanthi Balaraman Pradeep S. B. Podila Uchenna A. Agbim Benedict Maliakkal Sallyanne Fossey Sanjaya K. Satapathy Keiichi Sumida Csaba P. Kovesdy Satheesh Nair James D. Eason Miklos Z. Molnar 《Transplant international》2020,33(2):202-215
There is a dearth of published data regarding the presence of post-transplant donor-specific antibodies (DSA), especially C1q-binding DSA (C1q+DSA), and patient and kidney allograft outcomes in simultaneous liver–kidney transplant (SLKT) recipients. We conducted a retrospective cohort study consisted of 85 consecutive SLKT patients between 2009 and 2018 in our center. Associations between presence of post-transplant DSA, including persistent and/or newly developed DSA and C1q+DSA, and all-cause mortality and the composite outcome of mortality, allograft kidney loss, and antibody-mediated rejection were examined using unadjusted and age and sex-adjusted Cox proportional hazards and time-dependent regression models. The mean age at SLKT was 56 years and 60% of the patients were male. Twelve patients (14%) had post-transplant DSA and seven patients (8%) had C1q+DSA. The presence of post-transplant DSA was significantly associated with increased risk of mortality (unadjusted model: Hazard Ratio (HR) = 2.72, 95% confidence interval (CI): 1.06–6.98 and adjusted model: HR = 3.20, 95% CI: 1.11–9.22) and the composite outcome (unadjusted model: HR = 3.18, 95% CI: 1.31–7.68 and adjusted model: HR = 3.93, 95% CI: 1.39–11.10). There was also higher risk for outcomes in recipients with C1q+DSA compared the ones without C1q+DSA. Post-transplant DSA is significantly associated with worse patient and kidney allograft outcomes in SLKT. Further prospective and large cohort studies are warranted to better assess these associations. 相似文献
68.
69.
Effects of platelet inhibitors on the platelet aggregation induced by plasma from patients with thrombotic thrombocytopenic purpura 总被引:3,自引:0,他引:3
Antiplatelet drugs have been used in the treatment of thrombotic thrombocytopenic purpura (TTP) but there in vivo efficacy remains controversial. It has been shown that, in vitro, the plasmas obtained from patients with TTP induced the aggregation of washed platelets from normal donors as well as patients in remission. The effects of platelet inhibitors on the TTP plasma-induced platelet aggregation were examined. It was found that aspirin, indomethacin, ibuprofen, sulfinpyrazone, 5, 8, 11, 14-eisacotetraynoic acid, prostaglandin E1, prostaglandin I2, dBcAMP, apyrase, creatine phosphate/creatine phosphokinase, antimycin, 2-deoxy-D-glucose, dipyridamole, clofibrate, dextran 40, dextran 70, dibucaine, xylocaine, methylmaleimide, and ethylenediamine tetraacetic acid had little or no effect at all. These data lead us to conclude that at least in certain cases, antiplatelet drugs probably play a limited role in the treatment of patients with TTP. 相似文献
70.
Pairs of sequential perfusion lung scans and pulmonary angiograms obtained in 45 patients were reviewed to investigate the utility of short-term, sequential scintigraphy in the diagnosis of pulmonary embolism (PE). Forty-six sequential scan pairs were reviewed; 13 were ventilation-perfusion (V-P) pairs. Angiograms were obtained within 48 hours of either the first (65%) or second (35%) perfusion scan in each pair. Sequential scintigraphic patterns were classified as showing change (i.e., improvement in defects, new defects), no change, or as being indeterminate. A changing perfusion pattern was associated with a high (20/23) likelihood of PE, but seven of 16 patients with stable perfusion patterns also had PE. The sensitivity of a changing perfusion pattern for PE was 0.74 (20/27) and its specificity was 0.75 (9/12). In two of six patients who had serial V-P studies that showed changing perfusion defects, there were matched changes in regional ventilation and angiograms were negative. The findings suggest that short-term serial perfusion lung scanning may aid the scintigraphic diagnosis of PE in certain circumstances. Serial V-P imaging is needed, however, to maximize diagnostic specificity. 相似文献