全文获取类型
收费全文 | 1925篇 |
免费 | 108篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 52篇 |
妇产科学 | 70篇 |
基础医学 | 263篇 |
口腔科学 | 103篇 |
临床医学 | 193篇 |
内科学 | 339篇 |
皮肤病学 | 13篇 |
神经病学 | 163篇 |
特种医学 | 63篇 |
外科学 | 311篇 |
综合类 | 9篇 |
一般理论 | 4篇 |
预防医学 | 156篇 |
眼科学 | 20篇 |
药学 | 170篇 |
中国医学 | 1篇 |
肿瘤学 | 88篇 |
出版年
2022年 | 12篇 |
2021年 | 21篇 |
2020年 | 18篇 |
2019年 | 15篇 |
2018年 | 22篇 |
2017年 | 13篇 |
2016年 | 22篇 |
2015年 | 23篇 |
2014年 | 39篇 |
2013年 | 91篇 |
2012年 | 79篇 |
2011年 | 76篇 |
2010年 | 52篇 |
2009年 | 58篇 |
2008年 | 111篇 |
2007年 | 104篇 |
2006年 | 96篇 |
2005年 | 117篇 |
2004年 | 83篇 |
2003年 | 81篇 |
2002年 | 93篇 |
2001年 | 46篇 |
2000年 | 38篇 |
1999年 | 44篇 |
1998年 | 31篇 |
1997年 | 24篇 |
1996年 | 16篇 |
1995年 | 20篇 |
1994年 | 20篇 |
1993年 | 26篇 |
1992年 | 27篇 |
1991年 | 31篇 |
1990年 | 27篇 |
1989年 | 37篇 |
1988年 | 25篇 |
1987年 | 26篇 |
1986年 | 33篇 |
1985年 | 56篇 |
1984年 | 30篇 |
1983年 | 24篇 |
1982年 | 20篇 |
1981年 | 17篇 |
1980年 | 12篇 |
1979年 | 27篇 |
1978年 | 16篇 |
1977年 | 21篇 |
1975年 | 16篇 |
1974年 | 12篇 |
1973年 | 13篇 |
1970年 | 12篇 |
排序方式: 共有2045条查询结果,搜索用时 11 毫秒
21.
Soisalon-Soininen S Salo JA Perhoniemi V Mattila S 《Annales chirurgiae et gynaecologiae》1999,88(1):38-43
BACKGROUND AND AIMS: The pain of an abdominal aortic aneurysm (AAA) is believed to signify rupture, and emergency surgery for symptomatic AAA is a widely accepted practice to prevent rupture. To clarify the benefit of emergency surgery we evaluated the clinical course of emergency treated patients with non-ruptured AAAs. MATERIAL AND METHODS: 110 patients (90 men, mean age 69, range 49-93; 20 women, mean age 75, range 63-89) underwent emergency repair of non-ruptured AAA between 1970 and 1992 at the Department of Thoracic and Cardiovascular Surgery of Helsinki University Central Hospital (HUCH). Survival rates after surgery were analysed using product-limit-survivorship method. The survival rates after age-stratification were compared with those of patients undergone elective surgery (n=599) or emergency surgery because of ruptured AAAs (n=363) during the same period. Risk factors affecting early and late survival rates after operation were analysed by logistic regression analysis and Cox proportional hazard model. RESULTS: Thirty-day operative mortality rates were 18 % (20/110) in the emergency non-ruptured group, compared with 7 % (42/599) in the elective group and 49 % (179/363) in the ruptured group (p<0.05). Thirty day survival rate was not changed among the nonruptured emergency group from 1970 to 1992, whereas the rates of ruptured and elective groups became better during the study period. Late survival rates for 30-day postoperative survivors were clearly reduced among the non-ruptured emergency group, without difference between the emergency operated ruptured and non-ruptured groups. Coronary artery disease was decreasing significantly early and late survival rates after emergency surgery for non-ruptured AAAs (p<0.05, logistic regression and p<0.001 Cox proportional hazard). CONCLUSIONS: Early and late mortality risk is significantly higher (p<0.001) after emergency surgery for haemodynamically stable non-ruptured AAA than after elective surgery, mainly because of coronary artery disease. 相似文献
22.
J Kauppinen T Nousiainen E Jantunen R Mattila M L Katila 《Infection control and hospital epidemiology》1999,20(5):343-345
Nosocomial acquisition of Mycobacterium fortuitum led to a disseminated infection in a leukemia patient. A linkage to showerhead water was supported by molecular typing of clinical and environmental isolates. Contamination of the hospital water system with microbes that are relatively resistant to common sanitation processes poses an increased risk of infection to neutropenic patients. 相似文献
23.
Rebecca Troisi Nancy Potischman James M Roberts Gail Harger Nina Markovic Bernard Cole David Lykins Pentti Siiteri Robert N Hoover 《Cancer epidemiology, biomarkers & prevention》2003,12(5):452-456
Evidence suggests that adult cancer risk of hormonally related tumors may be influenced by the in utero environment, and most speculation on the biological mechanism has focused on the hormonal component. Epidemiological studies investigating the biological nature of pregnancy and maternal factors associated with offspring's cancer risk have relied on maternal hormone measurements. The degree to which maternal hormone levels represent the fetal environment, however, is not widely known. Pregnancy estrogen, androstenedione, testosterone, dehydroepiandrosterone (DHEA), and DHEA-sulfate concentrations were measured in maternal and mixed umbilical cord sera from 86 singleton pregnancies. Spearman correlations between maternal and cord hormone levels generally ranged between 0.2 and 0.3. The correlation was 0.26 for estriol, the estrogen of highest concentration in pregnancy, and 0.27 for estradiol, the most biologically active estrogen. The correlations between mother and offspring for the estrogens and DHEA appeared similar for males and females, whereas there was a suggestion that the maternal-umbilical cord correlations for other androgens varied in magnitude by fetal sex, and all correlations appeared higher in pregnancies lasting <38 weeks compared with longer gestational lengths, although these stratified findings may have been attributable to chance. These data show a moderate degree of correlation in hormone concentrations between the maternal and fetal circulation. Studies using maternal hormone concentrations as a proxy for the fetal environment should consider the misclassification resulting with the use of this marker. 相似文献
24.
Pekka Venesmaa Clinical Research Fellow Ulf-Håkan Stenman Consultant † Matti Forss Physicist Arto Leminen Consultant Pentti Lehtovirta Consultant Juhani Vartiainen Clinical Research Fellow Jorma Paavonen Associate Professor 《BJOG : an international journal of obstetrics and gynaecology》1998,105(5):508-511
Objective To evaluate the use of the pre-operative tumour-associated trypsin inhibitor (TATI) level and residual tumour size at primary surgery as a prognostic indicators for patients with Stage III epithelial ovarian cancer.
Design Retrospective cohort study.
Setting Department of Obstetrics and Gynaecology, University Hospital, Helsinki, Finland.
Participants Ninety-eight women with Stage III ovarian cancer.
Methods TATI was measured by radioimmunoassay from serum samples obtained within one week before surgery. A cutoff value of 22 μg/L was used. Multivariate analysis included pre-operative TATI level, age, histologic grade and histologic type. Mantel-Cox test was used for calculating statistical significance of differences in survival between groups.
Main outcome measures Cumulative five-year survival, pre-operative serum TATI level and residual tumour size.
Results Surgery was optimal (residual tumour size ≤ 2 cm) in 55 patients and suboptimal (residual tumour size > 2 cm) in 43. Pre-operative TATI level ≤ 22 μg/L predicted better prognosis both in patients with optimal and suboptimal surgery compared with patients with pre-operative TATI level > 22 μ/L. Patients with optimal surgery and a pre-operative TATI > 22 μg/L had a twofold relative risk of death compared with those with a pre-operative TATI ≤ 22 μg/L. The cumulative survival was less than three years for patients with suboptimal surgery and pre-operative TATI > 22 μg/L.
Conclusions Pre-operative serum TATI in combination with residual tumour size may be useful in stratifying patients with Stage III ovarian cancer into different categories in randomised treatment trials. 相似文献
Design Retrospective cohort study.
Setting Department of Obstetrics and Gynaecology, University Hospital, Helsinki, Finland.
Participants Ninety-eight women with Stage III ovarian cancer.
Methods TATI was measured by radioimmunoassay from serum samples obtained within one week before surgery. A cutoff value of 22 μg/L was used. Multivariate analysis included pre-operative TATI level, age, histologic grade and histologic type. Mantel-Cox test was used for calculating statistical significance of differences in survival between groups.
Main outcome measures Cumulative five-year survival, pre-operative serum TATI level and residual tumour size.
Results Surgery was optimal (residual tumour size ≤ 2 cm) in 55 patients and suboptimal (residual tumour size > 2 cm) in 43. Pre-operative TATI level ≤ 22 μg/L predicted better prognosis both in patients with optimal and suboptimal surgery compared with patients with pre-operative TATI level > 22 μ/L. Patients with optimal surgery and a pre-operative TATI > 22 μg/L had a twofold relative risk of death compared with those with a pre-operative TATI ≤ 22 μg/L. The cumulative survival was less than three years for patients with suboptimal surgery and pre-operative TATI > 22 μg/L.
Conclusions Pre-operative serum TATI in combination with residual tumour size may be useful in stratifying patients with Stage III ovarian cancer into different categories in randomised treatment trials. 相似文献
25.
Driving under light and dark conditions: effects of alcohol and diazepam in young and older subjects
Objectives: Driving at night time increases accident risk due to visual conditions, fatigue and impaired performance. In addition, the
use of alcohol and benzodiazepines may enhance the risks related to night-time driving. We studied these aspects of traffic
safety in a simulated driving test with young and older drivers.
Methods: In a double-blind, crossover, placebo-controlled study, nine young subjects, aged 22–24 years, performed simulated driving
in both `light' and `dark' conditions, before and 1.5 h and 4 h after 0.8 g · kg−1 ethanol (EOH) or 15 mg diazepam (DZ). Further, nine older subjects, aged 55–77 years, were similarly tested, but their EOH
dose was 0.7 g · kg−1 and the DZ dose was 10 mg. The tests were vigilance assessment on visual analogue scales (VAS), simulated driving under light
and dark conditions for 6 min each and digit symbol substitution (DSS).
Results: In the young subjects, both EOH and DZ similarly impaired DSS, with DZ causing more subjective drowsiness, clumsiness, mental
slowness and poor overall performance than EOH. During simulated driving, both EOH and DZ impaired simple and complex tracking
(EOH>DZ) and prolonged reaction times (EOH=DZ). Impairment of performance was practically identical under light and dark conditions.
In the older subjects, objective performance on DSS was poorer (−30%) than that of the young ones, and subjective impairment
was marginal. During simulated driving, the baseline levels of variables in older subjects showed definite impairment (errors
+100% to +500%) when compared with young subjects. Active drugs impaired several variables (EOH>DZ), but the statistical significances
were fewer than in young subjects. Increase in reaction errors reached statistical significance, especially while driving
in the dark. Otherwise the driving results in light and dark were not notably different.
Conclusion: Young subjects drew good baselines but were sensitive to EOH and DZ, whilst the older subjects showed poor baselines but
were less sensitive to EOH and DZ. Although the baseline driving and responses to treatments were different in young and older
subjects, their driving and psychomotor impairment were unaffected by light conditions.
Received: 10 November 1999 / Accepted in revised form: 25 April 2000 相似文献
26.
Pentti Koskela 《Vaccine》1985,3(5):389-391
A complement-fixing enzyme-linked immunosorbent assay (CF-ELISA) with bacterial sonicate as the antigen, human AB serum as the source of complement and alkaline-phosphatase-labelled anti-(human C3e) as the conjugate was developed for detecting antibodies to Francisella tularensis. Humoral responses after inoculation with a live attenuated tularemia vaccine were studied in 13 subjects by this method. Twelve responded with CF antibodies, which in most cases appeared 4 weeks after vaccination, the response time varying from 1 week to 2 months. The highest individual CF titres, of 140–9990, were reached 1–4 months after vaccination (average 2.4 months). The CF titres tended to decrease with time, and at 10 months two of the 12 subjects with an earlier CF positive response were negative again. CF antibodies were nevertheless still detectable in all three subjects studied 1.5 years after vaccination. 相似文献
27.
Honkanen PO Rautakorpi UM Huovinen P Klaukka T Palva E Roine R Sarkkinen H Varonen H Mäkelä M;MIKSTRA Collaborative Study Group 《Scandinavian journal of infectious diseases》2002,34(11):827-830
The objectives of this prospective epidemiological study were to describe the diagnosis and treatment of respiratory tract infections by Finnish general practitioners and to compare current practice with national evidence-based guidelines. All patients (n = 4386) seeking primary care for a respiratory tract infection for the first time in 30 health centres during 1 week in November 1998 participated in the study. The main outcome measures were the amounts and types of diagnostic tests used and antimicrobials prescribed. Tympanometry was used in 1% of patients with acute otitis media. Ultrasonography, sinus radiography or both were used in 80% of cases of sinusitis and antigen detection or culture for Streptococci in 57% of throat infections. In acute bronchitis, a chest radiograph was taken in 5% of cases and the CRP level determined in 8%. The corresponding figures for pneumonia were 49% and 39%. In pneumonia and throat infection, diagnostic testing was statistically significantly associated with the use of antimicrobials, but not in otitis, sinusitis or acute bronchitis. Diagnostic tests were underused in respiratory tract infections compared to evidence-based recommendations. 相似文献
28.
BACKGROUND: A family history of abdominal aortic aneurysm has been reported to increase the risk for developing the disease. OBJECTIVE: To determine the risk for abdominal aortic aneurysm in first-degree relatives of patients with the disease. DESIGN: Cross-sectional ultrasonographic screening study. SETTING: University Central Hospital, Helsinki, Finland. PATIENTS: 238 of 325 living first-degree relatives of patients having surgery for abdominal aortic aneurysm (age > 50 years; 98 men and 110 women) and 281 controls (135 men and 149 women) without a family history of abdominal aortic aneurysm. MEASUREMENTS: Ultrasonography was used to measure aortic diameter in 101 male relatives and 140 female relatives (241 of the 325 persons at risk [74%]) and in 281 controls. RESULTS: Three siblings had already undergone surgery for abdominal aortic aneurysm. Eleven siblings (all brothers) (11 of 101 [10.9%]) had ultrasonographic evidence of abdominal aortic aneurysm (aortic diameter > 30 mm). In the control group, 2 men (1.5%) and 2 women (1.3%) had an aneurysm. Thirty siblings and no controls had dilatation of the abdominal aorta (aortic diameter, 20 to 29 mm). Neither the age nor the sex of the proband affected risk for developing abdominal aortic aneurysm among first-degree relatives. Family history increased the risk for an aneurysm by 4.33-fold (95% CI, 1.32-fold to 14.23-fold), male sex increased the risk by 12.21-fold (CI, 2.63-fold to 56.64-fold), and age (by decade) increased the risk by 1.93-fold (CI, 1.15-fold to 3.25-fold). CONCLUSION: Aging brothers of patients with known abdominal aortic aneurysm have the highest risk for developing the disease; the prevalence of the disease in siblings older than 60 years of age is 18%. 相似文献
29.
P. Männistö M.D. H. Haataja M.Sci. M. Karhunen M.D. J. Mattila M.D. O. Koskela M.D. A. -M. Suikkari M.D. P. Heinonen M.D. R. Tuimala M.D. 《Infection》1984,12(3):197-201
Summary Concentrations of metronidazole and tinidazole in serum and gynecological organs were analyzed after a single 500 mg intravenous infusion and after three days of treatment with 400 mg t.i.d. of metronidazole or 500 mg b.i.d. of tinidazole. The studies were performed in 67 patients subjected to hysterectomy and/or oophorectomy because of myomatosis uteri, carcinoma uteri or endometriosis. At the time of organ removal (about 30 min after infusion), metronidazole and tinidazole levels in serum were 14.5 ± 0.45 mg/l and 12.3 ± 0.38 mg/l, respectively. Concentrations of both drugs in the uterus and Fallopian tube were about the same as the simultaneous serum levels and concentrations in the ovaries about 55% thereof. At steady-state, the concentrations of tinidazole in serum (23.5 ± 1.0 mg/l) were remarkably higher than those of metronidazole (13.5 ± 0.84 mg/l) about three hours after the last oral dose. Drug concentrations in organs of the female reproductive tract were 70 to 100% those of the simultaneous serum levels.
Konzentrationen von Metronidazol und Tinidazol in weiblichen Genitalorganen nach intravenöser Einzelinfusion und wiederholter oraler Gabe
Zusammenfassung Die Konzentrationen von Metronidazol und Tinidazol in Serum und Genitalorganen wurden nach einer intravenösen Einzelinfusion von 500 mg sowie nach dreitägiger oraler Behandlung mit 400 mg Metronidazol dreimal täglich oder 500 mg Tinidazol, zweimal täglich, bestimmt. Die Untersuchungen wurden bei 67 Patientinnen durchgeführt, bei denen eine Hysterektomie und/oder Oophorektomie wegen Myomatosis uteri, Uteruskarzinom oder Endometriose vorgenommen wurde. Zum Zeitpunkt der Organentnahme (etwa 30 min nach Infusion) betrugen die Metronidazol-und Tinidazolspiegel im Serum 14,5 ± 0,45 mg/l bzw. 12,3 ± 0,38 mg/l. Die Konzentrationen der beiden Medikamente im Uterus und in der Tube entsprachen den gleichzeitig bestimmten Serumspiegeln; die Konzentrationen in den Ovarien lagen bei etwa 55% der Serumspiegel. Im Steady state, etwa drei Stunden nach der letzten oralen Dosis, waren die Serumkonzentrationen von Tinidazol mit 23,5 ± 1,0 mg/l erheblich höher als die Metronidazolserumspiegel (13,5 ± 0,84 mg/l). Die Konzentrationen der Medikamente in den weiblichen Genitalorganen lagen bei 70 bis 100% der simultanen Serumspiegel.相似文献
30.
We have assessed the angiographic features of a group of 37 patients given oral dipyridamole and 37 patients given matching placebo. Both groups represented severe coronary arterial disease and were studied prior to bypass surgery. Six patients (16%) had angina and 13 patients (35%) had electrocardiographic changes after dipyridamole. All the patients in the control group were nonresponders. In the group given dipyridamole the patients responding with angina had significantly more compromised collaterals than the patients without chest pain (P = 0.021). The same applied to the patients with electrocardiographic changes versus those with no electrocardiographic changes (P = 0.034). No differences between responders and nonresponders could be found in terms of the severity of coronary arterial disease, severity of anginal symptoms, exercise tolerance, antianginal medication, number of past myocardial infarctions, and left ventricular ejection fraction. In conclusion, the data strongly suggest that ischaemic responses to dipyridamole originate from myocardial steal accentuated by compromised flow in collateral vessels. 相似文献