全文获取类型
收费全文 | 3427篇 |
免费 | 255篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 139篇 |
妇产科学 | 99篇 |
基础医学 | 523篇 |
口腔科学 | 115篇 |
临床医学 | 400篇 |
内科学 | 664篇 |
皮肤病学 | 79篇 |
神经病学 | 301篇 |
特种医学 | 78篇 |
外科学 | 476篇 |
综合类 | 38篇 |
一般理论 | 2篇 |
预防医学 | 262篇 |
眼科学 | 27篇 |
药学 | 231篇 |
中国医学 | 4篇 |
肿瘤学 | 206篇 |
出版年
2023年 | 23篇 |
2022年 | 26篇 |
2021年 | 65篇 |
2020年 | 61篇 |
2019年 | 60篇 |
2018年 | 95篇 |
2017年 | 67篇 |
2016年 | 79篇 |
2015年 | 84篇 |
2014年 | 109篇 |
2013年 | 168篇 |
2012年 | 192篇 |
2011年 | 200篇 |
2010年 | 112篇 |
2009年 | 111篇 |
2008年 | 190篇 |
2007年 | 198篇 |
2006年 | 152篇 |
2005年 | 169篇 |
2004年 | 150篇 |
2003年 | 140篇 |
2002年 | 144篇 |
2001年 | 102篇 |
2000年 | 70篇 |
1999年 | 83篇 |
1998年 | 45篇 |
1997年 | 27篇 |
1996年 | 28篇 |
1995年 | 25篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 67篇 |
1991年 | 59篇 |
1990年 | 59篇 |
1989年 | 40篇 |
1988年 | 58篇 |
1987年 | 55篇 |
1986年 | 38篇 |
1985年 | 54篇 |
1984年 | 26篇 |
1983年 | 26篇 |
1982年 | 14篇 |
1979年 | 18篇 |
1978年 | 13篇 |
1977年 | 11篇 |
1975年 | 10篇 |
1974年 | 11篇 |
1972年 | 12篇 |
1971年 | 16篇 |
1969年 | 15篇 |
排序方式: 共有3689条查询结果,搜索用时 0 毫秒
1.
2.
3.
Olle Zetterström Christer Andersson Leif Eriksson ers Fredriksson Johan Friskopp Gunnar Heden Bernt Jansson Tord Lundgren Rolf Nilveus ers Olsson Stefan Renvert Lars Salonen Lars Sjöström ers Winell ers Östgren Stina Gestrelius 《Journal of clinical periodontology》1997,24(9):697-704
Abstract The aim of the present clinical trial was to test tolerability during 2 treatments with EMDOGAIN® in a large number of patients. An open, controlled study design in 10 Swedish specialist clinics was chosen, with a test group of 107 patients treated with EMDOGAIN® in connection with periodontal surgery at 2 surgical test sites per patient. The procedures were performed 2 to 6 weeks apart on one-rooted teeth with at least 4 mm deep intraosseous lesions. A control group of 33 patients underwent flap surgery without EMDOGAIN® at I comparable site. In total 214 test and 33 control surgeries were performed. Serum samples were obtained from test patients for analysis of total and specific antibody levels. 10 of the patients had samples taken before and after the first surgery. 56 other samples were taken after one treatment with EMDOGAIN®, and 63 after 2 treatments. None of the samples, not even from allergy-prone patients after 2 treatments, indicated deviations from established baseline ranges. This indicates that the immunogenic potential of EMDOGAIN® is extremely low when applied in conjunction with periodontal surgery. Comparison between the test and control groups demonstrated the same type and frequency of post-surgical experiences, i.e., reactions caused by the surgical procedure itself. Clinical probing and radiographic evaluation was performed at baseline and 8 months postsurgery. About half of the patients (44 test and 21 control) were also evaluated after 3 years. There was a significant difference between the test and control results at 8 months post surgery. and this difference had increased further at the 3 year follow-up. The 2.5–3 mm increase in attachment and bone level after treatment with EMDOGAIN® was of the same magnitude as seen in the studies with split-mouth design aiming for lest of effectiveness of EMDOGAIN®. 相似文献
4.
Cerebral function in normoxia and its reactions to standard periods of hypoxia of increasing severity were studied in 30 newborn guinea pigs less than 3 days old. Intrauterine growth retardation was induced either by uterine artery ligation at midgestation or by feeding the female in late gestation with khat leaves, an amphetamine-like stimulant chewed by men and women in several countries in eastern Africa and Arabia. After spontaneous delivery, the neonates were anesthetized and ventilated. Cardiovascular, metabolic, and neurophysiologic (somatosensory evoked potentials) parameters were monitored. Under normoxia, the khat-exposed group showed prolonged latency of the primary response of the somatosensory evoked potentials and a reduced amount of secondary components. Under hypoxia, this group also has a greater reduction of amplitude of the somatosensory evoked potentials. It is concluded that khat exposure during fetal life has an impact on the cerebral function during the neonatal period (at least up to 3 days of age) which is not solely explained by the concomitantly produced growth retardation. 相似文献
5.
R F Rossi R Ekroth K Jansson M Scallan R J Thompson C Lincoln 《Scandinavian journal of thoracic and cardiovascular surgery》1990,24(1):75-77
The concentration of brain type creatine kinase (CK-BB) was measured in blood from the internal jugular vein in 32 children (less than 1 year old) with congenital heart disease. In transposition of the great arteries the CK-BB levels were significantly higher than in children without cyanosis (10.1 +/- 4.1 vs. 3.0 +/- 0.5 ng/ml). A negative correlation was found for CK-BB concentration and arterial oxygen saturation (r = -0.41, p less than 0.02 for all children and r = -0.62, p less than 0.05 for those with tetralogy of Fallot). It is suggested that the increased CK-BB levels in the blood of cyanotic children reflect chronic cerebral hypoxia, which may explain other reports of reduced psycho-intellectual function in patients with cyanotic heart disease. 相似文献
6.
E Jansson V Bomfim M Grynfarb L Kaijser 《Scandinavian journal of thoracic and cardiovascular surgery》1986,20(2):137-140
Myocardial energy metabolism during hypothermic potassium cardioplegia with blood as the cardioplegia vehicle, given in one or two bolus doses, was studied in eight patients undergoing aortic valve replacement. Myocardial biopsies were taken from the left ventricle 10 min after aortic cross-clamping (a.c.) and immediately before declamping (d.c.) and were analyzed for ATP, creatine phosphate (CP), creatine (C) and lactate. The interindividual range of myocardial temperature was 11-19 degrees C at 10 min a.c. and 11-25 degrees C immediately before d.c. The myocardial ATP concentration fell (17.2 +/- 5.7-12.8 +/- 2.8 mmol X kg-1 dry muscle), the lactate concentration rose (64.7 +/- 35.8-136 +/- 33.8 mmol X kg-1 d.m.) and the total creatine pool (CP + C) was unchanged. Hypothermic blood cardioplegia conferred fairly good initial protection of the myocardium, but the reduction in ATP and the great lactate accumulation towards the end of cardioplegia, especially in patients with myocardial temperature reaching 19-25 degrees C, indicates that such protection is adequate only if the myocardial temperature is maintained between 11 and 18 degrees C. 相似文献
7.
B Jansson 《American journal of industrial medicine》1992,21(5):619-622
8.
It has been reported that GH stimulates fibroblast growth and wound healing. In the present study we measured the effect of locally applied GH on insulin-like growth factor (IGF-I) mRNA concentrations and granulation tissue formation in wound cylinders, implanted s.c. Four stainless-steel wiremesh cylinders were implanted s.c. in the back of male rats (280 g). Each cylinder was then injected every day with either 0.014 or 0.14 U human GH, or vehicle only. Ingrown granulation tissue and wound fluid was obtained on day 17 after implantation. The wet weight of granulation tissue was determined and concentrations of IGF-I mRNA in the tissue were measured by solution hybridization/RNAase protection assay. Similar assays were used to measure the levels of IGF-I receptor mRNA and GH receptor mRNA, while the IGF-I concentration in wound fluid and serum was determined by radioimmunoassay (RIA) after acid-ethanol extraction. The concentrations of IGF-I mRNA in ingrown granulation tissue as well as the wet weight of this tissue were significantly higher in the GH-treated cylinders. There was no significant effect of GH on IGF-I receptor mRNA and GH receptor mRNA levels. Consistent with the results of previous studies, wound fluid IGF-I levels were lower than serum IGF-I levels, but no significant difference was found between the GH-treated cylinders and the control cylinders. The results of the present study show that GH stimulates granulation tissue formation and increases the concentration of IGF-I mRNA in the ingrown granulation tissue. 相似文献
9.
Mother's education and perinatal problems in Finland. 总被引:5,自引:0,他引:5
E Hemminki J Meril?inen M Malin O Rahkonen J Teperi 《International journal of epidemiology》1992,21(4):720-724
This study using nationwide data expands a previous study from one area in Finland. The purpose was to study how perinatal problems (mortality, short gestation, low birthweight and low Apgar scores) vary by mother's social class, which is measured by level of education. Outcomes of all births in the 1987 Medical Birth Register were linked to the 1988 National Education Register with gives the estimated number of years of completed education. In unadjusted analyses, the lowest educational groups (less than 9 years) had the worst results for outcomes other than neonatal mortality. Results in the two highest educational groups (greater than or equal to 13 and 12 years of education) were similar and if anything, better in the second highest group. Excluding twins and adjusting for confounding variables (age, parity, county, urbanization of residence) by logistic regression analysis did not alter the results much. Adjustment for possible mechanisms correlated with social class (marital status, smoking, time of first antenatal visit) decreased the higher occurrence of low birthweight infants in the low educational groups. Reported previous miscarriages were more common in the higher educational groups. Based on the available background characteristics one would expect to have found the usual social gradient in perinatal problems to have persisted between the two highest educational groups. Further studies on factors causing the plateau in the gradient between these groups might be useful. 相似文献
10.
Malin Ernberg Sigvard Kopp 《Journal of oral and maxillofacial surgery》2002,60(9):1004-10; discussion 1010-11
PURPOSE: The purpose of this study was to determine the optimal concentration and volumes of ropivacaine for dental anesthesia as regards onset and duration of action. SUBJECTS AND METHODS: Thirty healthy individuals with a mean age of 32 years participated in the study on a voluntary basis. All subjects received a ropivacaine injection in 1 of 3 randomized concentrations (2.0, 5.0, or 7.5 mg/mL) for infiltration anesthesia and mandibular nerve block in a double-blind manner. The onset time and duration of anesthesia were assessed by electric pulp test, pinprick test of the gingiva, and presence of feeling of numbness of the lip. RESULTS: Regardless of dose, only 5 patients received pulpal anesthesia after infiltration, but all 3 concentrations anesthetized the gingiva and upper lip. The onset of pulpal anesthesia occurred less than 5 minutes after injection and lasted for 4 to 58 minutes. Pinprick anesthesia lasted for 8 to 48 minutes, and numbness of the upper lip lasted 1 to 4 hours. The effectiveness of the mandibular nerve block with regard to pulpal anesthesia was dose dependent. Only ropivacaine at 7.5 mg/mL produced sufficient anesthesia. The onset of pulpal anesthesia occurred less than 10 minutes after injection and lasted for 2 to 6 hours. Pinprick anesthesia lasted for 3 to 6 hours and numbness of the lower lip lasted for 5 to 9 hours. CONCLUSION: This study shows that ropivacaine could be useful as a local anesthetic for mandibular nerve block in dentistry and that the very long duration of both pulpal and soft tissue anesthesia may be favorable in reducing postoperative pain. 相似文献