全文获取类型
收费全文 | 2352359篇 |
免费 | 175991篇 |
国内免费 | 5859篇 |
专业分类
耳鼻咽喉 | 32347篇 |
儿科学 | 79398篇 |
妇产科学 | 64507篇 |
基础医学 | 340339篇 |
口腔科学 | 64012篇 |
临床医学 | 219334篇 |
内科学 | 457580篇 |
皮肤病学 | 49122篇 |
神经病学 | 191025篇 |
特种医学 | 89135篇 |
外国民族医学 | 912篇 |
外科学 | 341727篇 |
综合类 | 51922篇 |
现状与发展 | 2篇 |
一般理论 | 809篇 |
预防医学 | 192275篇 |
眼科学 | 52179篇 |
药学 | 174238篇 |
8篇 | |
中国医学 | 5078篇 |
肿瘤学 | 128260篇 |
出版年
2019年 | 18743篇 |
2018年 | 26342篇 |
2017年 | 19817篇 |
2016年 | 21655篇 |
2015年 | 24723篇 |
2014年 | 34234篇 |
2013年 | 52857篇 |
2012年 | 72521篇 |
2011年 | 76907篇 |
2010年 | 45315篇 |
2009年 | 42402篇 |
2008年 | 71616篇 |
2007年 | 76211篇 |
2006年 | 76498篇 |
2005年 | 74189篇 |
2004年 | 71522篇 |
2003年 | 68774篇 |
2002年 | 66926篇 |
2001年 | 108220篇 |
2000年 | 112026篇 |
1999年 | 94622篇 |
1998年 | 26778篇 |
1997年 | 24174篇 |
1996年 | 24279篇 |
1995年 | 23090篇 |
1994年 | 21783篇 |
1993年 | 20337篇 |
1992年 | 75816篇 |
1991年 | 74243篇 |
1990年 | 72014篇 |
1989年 | 68639篇 |
1988年 | 63459篇 |
1987年 | 62291篇 |
1986年 | 58714篇 |
1985年 | 56193篇 |
1984年 | 42449篇 |
1983年 | 35909篇 |
1982年 | 21236篇 |
1981年 | 19174篇 |
1979年 | 38224篇 |
1978年 | 26982篇 |
1977年 | 22471篇 |
1976年 | 21564篇 |
1975年 | 22712篇 |
1974年 | 27124篇 |
1973年 | 26388篇 |
1972年 | 24321篇 |
1971年 | 22385篇 |
1970年 | 20988篇 |
1969年 | 19038篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
Imipenem (N-F-thienamycin) versus netilmicin plus clindamycin. A controlled and randomized comparison in intra-abdominal infections 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In a randomized study the clinical and bacteriologic effectiveness of imipenem was compared with the classical combination of netilmicin with clindamycin in patients who had surgery for an intraperitoneal infection, localized or generalized, with positive bacteriologic findings of the specimen taken at surgery. Excluded were all patients who received other antibiotics before surgery, or who died within 3 days after antibiotic therapy was started. Imipenem was given at a dose of 500 mg t.i.d., clindamycin 600 mg t.i.d., and netilmicin according to serum levels. The diagnoses ranged from postoperative peritonitis, gallbladder empyema, perforated gastroduodenal ulcer, small bowel perforation with and without obstruction, and perforated appendicitis to perforation of the colon. The bacteriologic work-up included examination of the primary specimen (aerobic and anaerobic), the urine, feces, and serologic testing for Candida albicans once or twice a week and after the course of antibiotic therapy. In addition, pH measurements of abscesses and drainage fluids were performed. Ninety-three patients entered the study. Forty-seven patients were treated with imipenem (test group), and 46 patients were treated with the combination therapy (control group). The two groups did not show significant differences in age, sex, diagnostic groups, risk factors, primary bacteriology, and duration of therapy (mean: 6.7 days). Thirty-eight patients (80.9%) treated with imipenem were cured, six patients (12.8%) were improved, and there were three (6.4%) failures. The respective numbers for the control group were 31 (67.4%), 10 (21.7%), and 5 (10.9%). The mean duration of hospitalization was 19 days for the test group and 24.5 days for the control group. There were four wound infections in the test group and 11 wound infections in the control group. Imipenem is at least as effective in the adjuvant therapy of intra-abdominal infections as the combination of netilmicin with clindamycin. 相似文献
932.
Two cases are presented in which the cause of small-bowel obstruction was enterolith originating in jejunal diverticula. 相似文献
933.
Ambient light affects pulse oximeters 总被引:1,自引:0,他引:1
934.
935.
Clinical and hormonal effects of chronic gonadotropin-releasing hormone agonist treatment in polycystic ovarian disease 总被引:1,自引:0,他引:1
K Steingold D De Ziegler M Cedars D R Meldrum J K Lu H L Judd R J Chang 《The Journal of clinical endocrinology and metabolism》1987,65(4):773-778
Previously, we reported that short term administration of a highly potent GnRH agonist (GnRHa) for 1 month to patients with polycystic ovarian disease (PCO) resulted in complete suppression of ovarian steroidogenesis without measurable effects on adrenal steroid production. This new study was designed to evaluate the effects of long term GnRHa administration in PCO patients with respect to their hormone secretion patterns and clinical responses. Eight PCO patients and 10 ovulatory women with endometriosis were treated daily with sc injections of [D-His6-(imBzl]),Pro9-NEt]GnRH (GnRHa; 100 micrograms) for 6 months. Their results were compared to hormone values in 8 women who had undergone bilateral oophorectomies. In response to GnRHa, PCO and ovulatory women had rises of serum LH at 1 month, after which it gradually declined to baseline. In both groups FSH secretion was suppressed throughout treatment. Serum estradiol, estrone, progesterone, 17-hydroxyprogesterone, androstenedione, and testosterone levels markedly decreased to values found in oophorectomized women by 1 month and remained low thereafter. In contrast, serum pregnenolone and 17-hydroxypregnenolone were partially suppressed, and dehydroepiandrosterone, dehydroepiandrosterone sulfate, and cortisol levels did not change. Clinically, hyperplastic endometrial histology in three PCO patients reverted to an inactive pattern, and proliferative endometrium in two other PCO patients became inactive in one and did not change in the other. Regression of proliferative endometrial histology occurred in all ovulatory women. Vaginal bleeding occurred in all women studied during the first month of GnRHa administration, after which all but one PCO patient became amenorrheic. Hot flashes were noted by all ovulatory women and by four of eight PCO patients. All PCO patients noted subjective reduction of skin oiliness, and five had decreased hair growth. We conclude that in premenopausal women: 1) chronic GnRHa administration results in apparently complete persistent suppression of ovarian steroid secretion; 2) adrenal steroid secretion is not influenced directly or indirectly; and 3) its use may be helpful in the treatment of endometrial hyperplasia and ovarian androgen excess in women with PCO. 相似文献
936.
Comparison of PET, MRI, and CT with pathology in a proven case of Alzheimer's disease 总被引:1,自引:0,他引:1
Positron emission tomography (PET) with fluorodeoxyglucose (FDG), magnetic resonance imaging (MRI), and CT were carried out in a patient with Alzheimer's disease 16 months before he died. At autopsy, the gross appearance of the brain correlated with MRI and CT, which showed some regional atrophy. These were much less revealing than PET, which correlated with microscopic findings of neuronal loss and proliferation of glia. In areas of moderately impaired local cerebral metabolic rate of glucose, as revealed by reduced FDG uptake, there was some gliosis, primarily around the numerous senile plaques. In areas of severe metabolic impairment, there was a profound loss of neurons, extensive gliosis, and a diminished appearance of plaques. PET-FDG is a better measure of the severity of Alzheimer's disease than MRI or CT, because it reflects the degree of neuronal pathology. 相似文献
937.
Sub-trigonal phenol injection ensures a satisfactory response in about 50% of patients with detrusor instability. When oral anticholinergic treatment is poorly tolerated or ineffective, this minimally invasive technique has been found, in our series of 11 patients, to be a useful adjunct, at least temporarily. 相似文献
938.
939.
Clinical experience of phototherapy for non-haemolytic hyperbilirubinaemia in 3999 infants in Kandang Kerbau Hospital, Singapore, is documented. Phototherapy was most effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1500 g) and least effective in full term infants with very low birth weight (gestation greater than or equal to 37 weeks, birth weight less than or equal to 1500 g) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2270 g). Overall, phototherapy was effective in almost all the infants, with a failure rate of only 2.00/1000 infants. No characteristic features common to all the failures could be detected. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1000), with the response to the second exposure comparable to that to the first. No infant required a third exposure. All the infants tolerated phototherapy well, none developing any illness that could be attributed to the treatment. This clinical experience shows that phototherapy for the treatment of nonhaemolytic hyperbilirubinaemia is effective and safe. 相似文献
940.
Electrophysiologic effects of halothane and quinidine on canine Purkinje fibers: evidence for a synergistic interaction 总被引:3,自引:0,他引:3
The authors studied possible interactions between halothane and quinidine on the action potentials of canine Purkinje fibers superfused with Tyrode's solution. Using standard microelectrode techniques and a physiologic pacing rate (2 Hz), halothane in concentrations from 0.5% to 2% decreased the action potential duration to 50% repolarization (ADP50). Total ADP (APD100), in contrast, increased after 1% and 2% halothane. Resting membrane potential (RMP) and action potential amplitude (APamp) increased after 0.5% halothane, but returned to control with higher halothane levels. Conduction time (CT) increased at each halothane level. Pacing at faster (3 Hz) or slower (1 Hz) rates did not markedly alter the effects of halothane. Quinidine 1 X 10(-5)M decreased the phase O upstroke (Vmax) and prolonged APD100 and CT. When halothane was added, RMP and APamp decreased, Vmax decreased further, and APD100 and CT were markedly prolonged. This resulted in conduction block or inexcitability, especially at faster pacing rates (3 Hz). Synergistic interactions between halothane and quinidine were found on RMP, APamp, APD100, and CT. Effects on Vmax, APD50, and action potential duration to 90% repolarization (APD90) were additive. It is concluded that quinidine and halothane act synergistically to decrease action potential amplitude, lower RMP, and prolong conduction. Severe depression of conduction often progressed to conduction block or inexcitability when halothane, 2%, was administered during superfusion with therapeutic concentrations of quinidine. 相似文献