全文获取类型
收费全文 | 58426篇 |
免费 | 3427篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 886篇 |
儿科学 | 1762篇 |
妇产科学 | 1354篇 |
基础医学 | 8720篇 |
口腔科学 | 2156篇 |
临床医学 | 5474篇 |
内科学 | 10517篇 |
皮肤病学 | 1445篇 |
神经病学 | 6272篇 |
特种医学 | 2715篇 |
外科学 | 8235篇 |
综合类 | 201篇 |
一般理论 | 32篇 |
预防医学 | 3840篇 |
眼科学 | 1169篇 |
药学 | 3947篇 |
中国医学 | 87篇 |
肿瘤学 | 3086篇 |
出版年
2023年 | 320篇 |
2022年 | 217篇 |
2021年 | 485篇 |
2020年 | 570篇 |
2019年 | 604篇 |
2018年 | 1290篇 |
2017年 | 1108篇 |
2016年 | 1435篇 |
2015年 | 1147篇 |
2014年 | 1325篇 |
2013年 | 2473篇 |
2012年 | 3101篇 |
2011年 | 3536篇 |
2010年 | 1858篇 |
2009年 | 1187篇 |
2008年 | 3542篇 |
2007年 | 3703篇 |
2006年 | 3481篇 |
2005年 | 3394篇 |
2004年 | 3261篇 |
2003年 | 3312篇 |
2002年 | 3228篇 |
2001年 | 2539篇 |
2000年 | 3255篇 |
1999年 | 1711篇 |
1998年 | 566篇 |
1997年 | 486篇 |
1996年 | 359篇 |
1995年 | 296篇 |
1994年 | 318篇 |
1993年 | 311篇 |
1992年 | 269篇 |
1991年 | 216篇 |
1990年 | 214篇 |
1989年 | 276篇 |
1988年 | 205篇 |
1987年 | 208篇 |
1986年 | 216篇 |
1985年 | 273篇 |
1984年 | 313篇 |
1983年 | 262篇 |
1982年 | 256篇 |
1981年 | 221篇 |
1980年 | 205篇 |
1979年 | 234篇 |
1978年 | 176篇 |
1977年 | 188篇 |
1976年 | 192篇 |
1975年 | 163篇 |
1973年 | 169篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
161.
Addiction in women has many implications in the field of obstetrics and gynecology. Particularly in obstetrical care, the health needs of the unborn as well as of the pregnant patients have to be considered. Therefore, early somatic and psychosocial help should be offered to pregnant women with addiction disorders. The main elements of this concept will be presented along with a summary of typical comorbidity issues in these patients, the handling of drug-related emergencies, and the management of perioperative replacement therapy. 相似文献
162.
R. M. Escorihuela A. Fernández-Teruel A. Tobeña W. Langhans K. Bättig P. Driscoll 《Behavior genetics》1997,27(6):573-578
An inbreeding program has been carried out with the Swiss sublines of Roman high- and low-avoidance rats since 1993. The present study reports the first experiments conducted with young animals of those inbred strains (RHA-I/Verh and RLA-I/Verh, respectively) from the sixth and seventh inbreeding generations. The results confirmed expected behavioral profiles. Compared to the RHA-I/Verh strain, RLA-I/Verh rats showed decreased entries into the illuminated central arena of an hexagonal tunnel maze, as well as decreased spontaneous locomotor activity and increased defecations, in two independent experiments. Young RLA-I/Verh females explored less than did their RHA-I/Verh counterparts during session 1 of a conditioned-fear experiment preceding shock administration, and in session 2 (conducted 24 h after the application of three footshocks), they showed greater conditioned behavioral inhibition (i.e., reduced amount of rearing), as well as higher defecation scores, than did RHA-I/Verh females.Karl Bättig tragically and unexpectedly died on December 27, 1996 相似文献
163.
This study examined the phenomenon of acute tolerance to ethanol (ETOH) using drug discrimination learning (DDL), and open-field (OF) procedures. In DDL, rats were trained to discriminate between ETOH (1.2 g/kg) and saline. Doses of ETOH lower (0.6 and 0.9 g/kg), or higher (1.8 and 2.4 g/kg) than the training dose were tested to examine possible influence of ETOH pretreatment doses on the expression of acute tolerance. To assess concentrations of ETOH in the organism, a rebreathed air procedure was used. Equal concentrations after different ETOH doses were achieved by postponing the tests until sufficient time had elapsed. Only doses of ETOH higher than the training dose produced acute tolerance in the DDL procedure. For the response-time data no acute tolerance was observed. In the OF experiment, the occurrence of acute tolerance was examined for different spontaneous behaviours in drug-naive animals. At equal ETOH concentrations, the group examined during the descending phase of intoxication (1.8 g/kg, 60 min post-injection), reared significantly more than the group tested during the ascending phase (1.5 g/kg, 10 min post-injection). Other OF behaviours did not differ significantly between the two time intervals. Thus, it is suggested that acute tolerance is seen both in ETOH naive and in ETOH pre-exposed rats. However, in DDL acute tolerance was observed only when doses higher than the training dose of ETOH were evaluated. 相似文献
164.
Andor Erdelyil Teuvo Sihvonen Pertti Helin Osmo Hänninen 《International archives of occupational and environmental health》1988,60(2):119-124
Summary Keyboard work consists mostly of dynamic contractions of the small muscles of the forearms and hands. This is accompanied by continuous activity in the arm, shoulder and neck muscles keeping the head and hand in the correct position. Eliminating the weight from the arm by means of support and the position of the arms influences the electrical activity of shoulder muscles when working at a keyboard. We studied the influence of elbow angle, as well as that of different arm supports, on electrical activity of upper trapezius muscle during keyboard work in healthy workers and persons suffering from shoulder pains. The measurements were carried out in the laboratory. EMG activities, which where measured as mean square root (RMS)-values at every 100-millisecond period in trapezius muscle when working, were lower, the greater the elbow angle. Furthermore electrical activity decreased when subjects used arm supports while working. It is evident that the static load to shoulder muscles can be lowered significantly in keyboard work, when the forearms are at an angle of at least 100 degrees and by using arm supports. The most convienient and ergonomic working position can also be found individually be the method used here. 相似文献
165.
166.
167.
168.
The effects of single oral doses of ketoconazole 400 mg and terbinafine 500 mg on the hepatic microsomal system have been investigated in 8 healthy male volunteers. Microsomal activity caffeine was assessed by following the metabolism of 3 mg/kg bodyweight i.v. administered 1 h after the drug. The inhibitory effect of terbinafine was more pronounced than that of ketoconazole: clearance was decreased from 1.34 ml.kg-1.min-1 in controls to 1.06 and 1.21 ml.kg-1.min-1, respectively, and the corresponding half-life was increased from 5.8 h in controls to 7.6 and 6.7 h, respectively. The apparent volume of distribution remained unchanged. The serum levels of the antimycotics were within the therapeutic range in each subject. Although all three substances are metabolised by microsomes, the kinetic parameters (Cmax, half-life, elimination constant) of the antimycotics were poorly if at all correlated with the elimination of caffeine. 相似文献
169.
Closing patellar tendon defects after anterior cruciate ligament reconstruction: absence of any benefit 总被引:4,自引:2,他引:2
Sveinbjörn Brandsson E. Faxén Bengt I. Eriksson Peter Kälebo Leif Swärd Olof Lundin J. Karlsson 《Knee surgery, sports traumatology, arthroscopy》1998,6(2):82-87
The most common graft in anterior cruciate ligament (ACL) surgery involves using the central one-third of the patellar tendon.
Knowledge concerning the postoperative disability after harvesting the patellar tendon is, however, limited. The aim of this
study was to evaluate the impact patellar tendon suture and bone grafting of the patellar bone defect might have in terms
of functional outcome and patellofemoral pain after harvesting the bone-tendon-bone graft, compared with leaving the harvested
site non-sutured and non-grafted. Sixty patients, scheduled for arthroscopically assisted ACL reconstruction, were randomly
allocated to two groups. In group I, suture of the patellar tendon and bone grafting of the patellar defect were performed.
In group II, the tendon gap and the patellar defect were left open. Preoperatively, there was no significant difference between
the groups when comparing objective knee stability, as measured with a KT-1000 laxity meter, Lysholm score, Tegner activity
level, IKDC score, or patellofemoral pain score. Both groups had a significantly improved Lysholm score at the 2-year follow-up,
without any difference between them. Tegner's activity level was significantly lower at follow-up, compared with the pre-injury
level in both groups. The patellofemoral pain score improved significantly after the reconstruction, without any difference
between the groups. Ultrasonography did not reveal any difference between the groups in terms of healing of the tendon gap.
This study revealed no differences in donor site morbidity, functional outcome, patellofemoral pain score or knee joint stability
between the two treatment groups. The conclusion is that suture of the patellar tendon and bone grafting of the patellar defect
do not improve the functional results or reduce donor site morbidity after arthroscopically assisted ACL.
Received: 17 December 1996 Accepted: 30 July 1997 相似文献
170.
J. Harro Charlotta Löfberg Rein Pähkla Vallo Matto Lembit Rägo Lars Oreland Lembit Allikmets 《Naunyn-Schmiedeberg's archives of pharmacology》1996,355(1):57-63
Cholecystokinin (CCK) is a neuropeptide recently implicated in affective disorders. This study aimed at measuring the levels
of different molecular forms of CCK and the binding characteristics of CCKB receptors in the rat brain after three weeks of treatment with four different antidepressants, imipramine, amitriptyline,
desipramine, and citalopram (all at the dose of 10 mg/kg once per day i.p.). Chronic treatment with imipramine and desipramine
had a significant immobility-reducing effect in the Porsolt‘s swim test. The effect of amitriptyline, albeit in the same direction,
was not significant, and citalopram had no effect in this test. In the elevated plus-maze test of anxiety, all drugs tended
to increase the number of open arm entries and the ratio open/total arm entries, but only the effects of imipramine were statistically
significant. None of the treatments affected the total levels of CCK or the levels of CCK-8-sulphated, CCK-8-nonsulphated,
CCK-5, or CCK-4 in the frontal cortex. There was no effect of the treatments on CCKB receptor binding in the frontal cortex, hippocampus, or striatum. Imipramine and amitriptyline, however, increased the affinity
of CCKB receptor binding in the hypothalamus. Thus, no consistent effect of chronic antidepressant treatment on the CCK-ergic neurotransmission
in the rats was found.
Received: 4 June 1996 / Accepted: 26 August 1996 相似文献