全文获取类型
收费全文 | 16570篇 |
免费 | 955篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 219篇 |
儿科学 | 419篇 |
妇产科学 | 189篇 |
基础医学 | 2067篇 |
口腔科学 | 612篇 |
临床医学 | 1469篇 |
内科学 | 3164篇 |
皮肤病学 | 333篇 |
神经病学 | 1785篇 |
特种医学 | 1259篇 |
外国民族医学 | 1篇 |
外科学 | 2432篇 |
综合类 | 149篇 |
一般理论 | 4篇 |
预防医学 | 1471篇 |
眼科学 | 320篇 |
药学 | 804篇 |
中国医学 | 15篇 |
肿瘤学 | 852篇 |
出版年
2021年 | 197篇 |
2020年 | 121篇 |
2019年 | 151篇 |
2018年 | 232篇 |
2017年 | 192篇 |
2016年 | 210篇 |
2015年 | 267篇 |
2014年 | 378篇 |
2013年 | 490篇 |
2012年 | 689篇 |
2011年 | 719篇 |
2010年 | 475篇 |
2009年 | 407篇 |
2008年 | 721篇 |
2007年 | 809篇 |
2006年 | 732篇 |
2005年 | 729篇 |
2004年 | 656篇 |
2003年 | 631篇 |
2002年 | 638篇 |
2001年 | 636篇 |
2000年 | 591篇 |
1999年 | 483篇 |
1998年 | 210篇 |
1997年 | 151篇 |
1996年 | 133篇 |
1995年 | 168篇 |
1994年 | 138篇 |
1993年 | 118篇 |
1992年 | 333篇 |
1991年 | 361篇 |
1990年 | 307篇 |
1989年 | 298篇 |
1988年 | 286篇 |
1987年 | 237篇 |
1986年 | 262篇 |
1985年 | 258篇 |
1984年 | 206篇 |
1983年 | 186篇 |
1982年 | 134篇 |
1981年 | 125篇 |
1980年 | 120篇 |
1979年 | 242篇 |
1978年 | 156篇 |
1977年 | 155篇 |
1975年 | 152篇 |
1974年 | 127篇 |
1973年 | 135篇 |
1972年 | 141篇 |
1970年 | 117篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Retrorenal colon: implications for percutaneous diskectomy 总被引:1,自引:0,他引:1
It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary. 相似文献
62.
The impact of the Texas 1989 motorcycle helmet law on total and head-related fatalities, severe injuries, and overall injuries. 总被引:7,自引:0,他引:7
The State of Texas implemented a mandatory total motorcycle helmet law for all operators and passengers, effective September 1, 1989. In this study the impact of this intervention on frequency of both total and head-related fatalities, severe injuries, and overall injuries for operators during the subsequent year was quantified. This quantification is important because 26 states in the United States fail to have strict, mandatory helmet laws. The Box-Tiao time-series intervention methodology is used to estimate secular trends before and changes after the implementation of the law, analyzing Department of Public Safety monthly injury accident data for a period of 6 years collected from traffic accident reports filed for each motorcycle injury accident. Trends in fatalities and injuries (except for head-related deaths) estimated before implementation of the law approximated the 9.4% average annual decline in motorcycle registrations. Additional declines of 12.6% and 57.0%, respectively, were estimated for total and head-related fatalities during the year after the law was implemented. Declines of 13.1% and 54.6% were estimated for severe injuries for total and head-related accidents. Declines of 12.3% and 52.9% were found for total and head-related injuries overall. 相似文献
63.
Judith V. Becker PhD John A. Hunter PhD Dennis Goodwin BS Meg S. Kaplan PhD Douglas Martinez MA 《Sexual abuse : a journal of research and treatment》1992,5(1):45-51
Twenty adolescent male sexual offenders were evaluated by penile plethysmography on two separate occasions. Stimuli consisted of 19, two-minute audiotaped cues. Test-retest reliability was demonstrated for 15 of the 19 audiotaped vignettes. The highest correlations were found for those sexual behaviors in which the adolescents had engaged. 相似文献
64.
Liliane Diefenthaeler Herter Eliete Golendziner Jos Antnio Monteiro Flores Marcelo Moretto Kristhiane Di Domenico Eduardo Becker Poli Mara Spritzer 《Journal of ultrasound in medicine》2002,21(11):1237-46; quiz 1247-8
OBJECTIVE: To describe pelvic sonographic findings in girls as old as 7 years, to compare prepubertal girls with girls who had isolated thelarche or central precocious puberty, and to verify the accuracy of sonographic variables for distinguishing prepubertal girls from girls with central precocious puberty. METHODS: Ninety-six prepubertal girls and 2 reference groups (8 girls with isolated thelarche and 8 with idiopathic central precocious puberty) were included. Ovaries were classified morphologically as homogeneous, paucicystic, macrocystic, multicystic, and having isolated cysts. Receiver operating characteristic curves were used to choose the best cutoff points. RESULTS: Chronologic and bone age were correlated with uterine length, area, and volume and ovarian volume in prepubertal girls (P < .0001). Ovarian morphologic characteristics in prepubertal girls differed significantly from those of the reference groups (P < .0001). The best cutoff points were uterine length of 4.0 cm, uterine area of 4.5 cm2, uterine volume of 3.0 cm3, and ovarian volume of 1.0 cm3. CONCLUSIONS: Uterine and ovarian growth are proportional to age in prepubertal girls. Mean ovarian volume greater than 1 cm3 showed 100% sensitivity and specificity for discriminating between prepubertal girls and girls with central precocious puberty. Microcysts are common in prepubertal girls, but the presence of 6 or more follicles up to 10 mm in diameter may suggest central precocious puberty in girls younger than 8 years. 相似文献
65.
Patrick Terheyden Jürgen C. Becker Christa Lurz George J. Kahaly Eva‐B. Brcker 《Journal der Deutschen Dermatologischen Gesellschaft》2003,1(1):30-35
Background: Scleromyxoedema is a rare disease of unknown aetiology that is characterized by deposition of mucin and sclerotic induration of the skin; it is associated with paraproteinaemia. Patients suffer from progressive disability due to immobilization and cosmetic disfigurement. Treatment of scleromyxoedema is a therapeutic challenge. The antimalarial hydroxychloroquine has a rapid and reliable effect in reticular erythematous mucinosis. Patients and methods: Four consecutive patients (two women, two men; median age: 50 years) with scleromyxoedema, three of them with IgG λ paraprotein, were treated with hydroxychloroquine. Treatment was initiated with 600 mg p. o. for 10 days, followed by 400 mg for at least 4 weeks, and 200 mg thereafter. Results: Complete remission of skin manifestations was achieved in one patient, whereas three patients achieved a partial remission of 61+, 5 and 25 months' duration. Notably, three patients felt increased mobility and reduced firmness of skin during the first week of treatment, which was reflected in a rapid reduction in dermal thickness. In one patient, dysphagia was reverted as evidenced by normalization of oesophageal clearance. Paraproteinaemia was not influenced at all. Side effects included one case of electroretinogram abnormalities after 19 months of therapy and one case of leucopenia after 3 months. Conclusion: Hydroxychloroquine is an effective form of therapy for scleromyxoedema, leading to rapid and prolonged alleviation of symptoms. 相似文献
66.
U. Lehmann G. Regel B. Ellendorf E. Rickels M. Lorenz H. Becker H. Tscherne 《Der Unfallchirurg》1997,100(9):705-710
Summary
A total of 208 multiple trauma patients with head injury (HI) were investigated who had been treated in the period from 1990
to 1995. The average age was 35.2 ± 17.7 years; the injury severity according to ISS was 30.2 ± 8.6 points; 20.5 % died as
a result of the HI; the mortality of all patients was 26.5 %. The Glasgow Coma Scale (GCS) was determined at an average of
22 min after trauma (8.0 ± 4.3 points) at the scene of accident. The patients were classified according to GCS into minor
HI (group 1: 14–15 points), moderate HI (group 2: 9–13 points) and severe HI (group 3: 3–8 points). Patient outcome was assessed
by the Glasgow Outcome Scale (GOS) and was classified as good (GOS 4 and 5) and poor (GOS 1, 2 and 3) outcome. At the latest,
2 h after trauma, a CT scan of the head (CCT) was done. The HI groups are compared regarding frequency of types of injury.
In all HI groups the fractures of the bony face occurred at the same frequency (36.0–38.9 %). The frequency of calotte fractures
(Kal-Fx) increased from group 1 (8.0 %) to 2 (19.2 %) and 3 (25.6 %); fractures of the skull base significantly differed between
group 1 (16.0 %), 2 (7.8 %) and 3 (33.4 %). Epidural hemorrhage (EDB) appeared only in group 2 (7.8 %) and 3 (6.7); subdural
hemorrhage was found in group 1 (2.7 %), 2 (7.8 %) and 3 (10.0 %). Subarachnoid hemorrhage (SAB) was significantly more frequently
seen, dependent on HI severity, in group 3 (26.7 %) compared to group 2 (11.7 %) and 1 (8.0 %). Intracerebral contusion (ICK)
significantly increased from group 1 (12.0 %) to 2 (27.3) and 3 (45.6 %). Brain swelling (BS) also significantly increased
from group 1 (8.0 %) to 2 (19.5 %) and 3 (49.0 %) and lesions of ventricles (VL) from group 1 (2.7 %) to 2 (11.7 %) and 3
(20.0 %). Midline shift (13.4 %) and signs of herniation (4.5 %) only occurred in group 3. The analysis of correlation/regression
and receiver operating characteristics was able to predict 79 % of patients' outcome accurately using GCS (r 0.54; P < 0.0001) alone, using CCT (r 0.65; P < 0.0001) 87 % were correctly predicted with significant variables Cal-Fx, EDB, SAB and BS. CCT with GCS (r 0.74; P < 0.0001) were able to predict 88 % accurately with significant variables Cal-Fx, EDB, BS and GCS. The combination of CCT
with GCS, age and ISS (r 0.78; P < 0.0001) was able to predict only 87 % correctly, although the r value was the highest; significant variables were Kal-Fx, EDB, BS, VL, GCS, age and ISS.
相似文献
67.
68.
69.
Carrie L. Randall PhD Raymond F. Anton MD Howard C. Becker PhD 《Alcoholism, clinical and experimental research》1988,12(3):412-416
The purpose of this study was to determine the role of alcohol-induced maternal hypothermia in the teratogenic actions of alcohol. C57BL/6J mice were administered an acute dose of alcohol (5.8 g/kg orally) or isocaloric sucrose on day 10 of gestation. One half of each group was placed for 6 hr in an incubator set at 32 degrees C and the other half was housed in the incubator at room temperature (22 degrees C). As expected, acute prenatal alcohol exposure at this time of gestation was associated with decreased birth weight and an increase in limb and kidney malformations. The significant alcohol x environmental temperature interaction on these dependent variables indicated that the teratogenic insult was not attenuated, but was in fact even greater for the 32 degrees C/alcohol group. An absence of a main effect of environmental temperature indicated that the 32 degrees C environment, per se, was not teratogenic. Thus, maternal hypothermia is probably not an etiological factor in animal models of fetal alcohol syndrome. Moreover, antagonism of alcohol-induced maternal hypothermia exacerbates the teratogenic actions of alcohol observed at room temperature. 相似文献
70.
The early and late results of bypass surgery in 124 patients with unresectable oesophageal cancer are reported. Patients were grouped according to the extent of disease: group A, tumour localized to the oesophagus where severe pulmonary disease contra-indicated oesophagectomy (n = 9); group B, tumour less than or equal to 10 cm in length with mediastinal invasion (n = 81); group C, tumour greater than 10 cm in length with mediastinal invasion and/or fixed malignant lymph nodes (n = 33). Extent of disease was not recorded in one patient. The operative mortality was 4 per cent but 9 other patients died in hospital (hospital mortality, 11 per cent). Mortality was increased in patients undergoing colon bypass and in those with a large tumour load but these differences failed to reach statistical significance. The most frequent complication was neck sepsis, secondary to leakage from the proximal end of the excluded oesophagus. Eighty-nine per cent of the survivors could eat a normal, unrestricted diet on discharge and eighty-two per cent of survivors had complete and lasting relief from dysphagia. Median survival after bypass was 5 months but survival was significantly improved by radiotherapy to the tumour (P less than 0.001). Gastric bypass with radiotherapy is indicated in patients with extra-oesophageal spread of malignancy and in patients with tumours localized to the oesophagus who are unfit for resection. Bypass surgery may be contra-indicated in patients with a primary tumour greater than 10 cm in length and/or fixed lymph node metastases because mortality is increased and survival after operation is short. 相似文献