全文获取类型
收费全文 | 617篇 |
免费 | 43篇 |
专业分类
儿科学 | 17篇 |
妇产科学 | 12篇 |
基础医学 | 106篇 |
口腔科学 | 25篇 |
临床医学 | 86篇 |
内科学 | 132篇 |
皮肤病学 | 20篇 |
神经病学 | 78篇 |
特种医学 | 23篇 |
外科学 | 50篇 |
综合类 | 5篇 |
预防医学 | 18篇 |
眼科学 | 2篇 |
药学 | 57篇 |
中国医学 | 3篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 11篇 |
2022年 | 3篇 |
2021年 | 11篇 |
2020年 | 14篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 16篇 |
2014年 | 20篇 |
2013年 | 25篇 |
2012年 | 20篇 |
2011年 | 34篇 |
2010年 | 17篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 27篇 |
2006年 | 24篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 13篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1992年 | 16篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 19篇 |
1988年 | 15篇 |
1987年 | 8篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1980年 | 5篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1973年 | 6篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1967年 | 5篇 |
1966年 | 9篇 |
1965年 | 3篇 |
排序方式: 共有660条查询结果,搜索用时 703 毫秒
1.
A new technique for ultrasonic examination of the hip joint was evaluated in neonatals and infants. An anterior approach was used with the sound sector centered over the femoral head and parallel to the femoral neck. The ultrasonograms corresponded to lateral radiographs of the joint with the leg in Lorenz' first position. It was possible to evaluate the size and depth of the acetabulum and the size and position of the femoral head. The projection also permitted a dynamic examination for determination of hip instability. Thus, the technique provided a method for an objective diagnosis in congenital dislocation of the hip (CDH). In 216 hips, the results of clinical evaluation for CDH were correlated with the degree of instability demonstrated by ultrasound. The comparison showed the clinical diagnosis to be highly inaccurate. 相似文献
2.
B Dahlstr?m 《International anesthesiology clinics》1986,24(2):29-42
Spinal opiate analgesia has opened an exciting new field of research and has also rapidly gained widespread clinical acceptance. This mode of administration has obvious and definite advantages over conventional pain therapy; however, the field is still at an early stage of development. More research is clearly needed to provide methods for coping with some of the drawbacks of this method of pain relief. Important areas for future research include (1) the CSF kinetics of opiates; (2) the physiological mechanisms underlying the rostral spread of drugs within the CSF compartment; (3) a search for safer and more selective drugs; and (4) an evaluation of the extent to which pain-modulating systems at different levels in the CNS can be regulated by opiates and drugs interfering with other neurotransmitters. In this context it is essential to emphasize the importance of simultaneous study of the pharmacokinetics and the pharmacodynamic/clinical effects in providing a rational basis for a better understanding of the mechanisms of actions underlying spinal opiate analgesia. 相似文献
3.
Various neocortical areas from four females aged 16–24 years with Rett syndrome (RS) were investigated and compared with
brains of therapy-resistant partial epilepsy (TRPE) patients (18–25 years), infantile autism (IA), and control brains (24
and 58 years). The cytoarchitecture of area 10 (frontal), area 21 (temporal), area 4 (primary motor cortex), and area 17 (primary
visual cortex) was studied by the combined Klüver-Barrera (luxol fast blue and cresyl violet) standard procedure. Autofluorescence
of lipofuscin, immunofluorescence of synaptic vesicle proteins [synaptophysin (p38)] and lectin-stained (Wisteria floribunda agglutinin) perineuronal nets (PNs) were studied in the cortices using dual-channel confocal laser scanning microscopy. The
brains of RS females show various types of morphological/cytoarchitectonical abnormalities of single pyramidal neurons in
layers II–III, and V–VII of different cortical areas. The abnormalities include mild losses of pyramidal neurons, more pronounced
in layers II and III than in layers V and VII, and more evident in frontal and temporal areas than in the visual cortex. Microdysgenesis,
including abnormalities due to neuronal migration disorders, was not found in RS, in contrast to the observations in TRPE
patients, strongly indicating that RS is not a neuronal migration disorder. Lipofuscin distribution was normal but amounts
were lower in RS cases than in control and TRPE brains. PNs were less expressed in cortices of the IA case, but were clearly
overexpressed in the motor cortex of RS. Quantitative analysis of p38 showed a decrease in the area occupied by p38 immunoreactivity
by 20–40% in RS compared with controls. It is concluded that RS could best be explained by a postnatal synaptogenic developmental
deficiency; the basic defect, however, is still completely unknown.
Received: 26 February 1996 / Revised, accepted: 11 July 1996 相似文献
4.
The distribution of GAP-43 in superior cervical ganglion (SCG) and iris were studied in normal animals and following decentralization using immunofluorescence and confocal laser scanning microscopy (CLSM). GAP-43-like immunoreactivity (LI) was compared with p38 (synaptophysin)-LI, and tyrosin hydroxylase (TH)-LI. In the control SCG, GAP-43-LI and p38-LI were mainly localized in nerve terminals around the principal neurons. The neuronal perikarya were negative for GAP-43, but positive for p38 in a perinuclear zone, as well as positive for TH. SIF cells (Small Intensely Fluorescent cells, ganglionic interneurons) were positive for GAP-43, TH and p38. One day after decentralization, GAP-43-LI and p38-LI in nerve terminals around principal neurons had disappeared. Some of the principal neurons showed a weak GAP-43-immunoreactivity. Three days post-decentralization, GAP-43- and p38-positive nerve terminals around the neurons had reappeared in considerable numbers and the intra-ganglionic nerve bundles were positive for both antibodies. In the control irides, GAP-43-LI and p38-LI were distributed in a varicose pattern in the nerve bundles, around blood vessels and in the network of terminals. Double labelling studies showed that GAP-43-LI was colocalized with TH-LI and p38-LI. The network of terminals in the dilator plate of the irides was quantified by measuring the fluorescence intensity of randomly selected areas, using CLSM. Three days after decentralization the intensity of GAP-43-LI and p38-LI had significantly increased. TH-LI had decreased 8 days after decentralization. The results indicate that GAP-43-LI and p38-LI are normally present in the nerve fibers and terminals of both pre- and post-ganglionic neurons in adult rats. The expression of GAP-43-LI and p38-LI in post-ganglionic neurons is preganglionically regulated, as indicated by the increased expression after decentralization. The expression of p38 in these neurons is probably regulated via mechanisms that are separate from those which regulate GAP-43, since it showed a different time course than that of GAP-43-LI. 相似文献
5.
A case, referred to the Department of Stomatognathic Physiology, G?teborg, with an unstable occlusion is presented. There was a facial asymmetry and the bony morphology differed markedly between the sides. No EMG activity in the masticatory muscles could be detected on the left side. It was diagnosed as a probable sequela to poliomyelitis in the childhood. The impact of altered muscle function on the bony structures and dentition is discussed. 相似文献
6.
The effect of volleyball playing on the knee extensor mechanism 总被引:3,自引:0,他引:3
U M Kujala T Aalto K Osterman S Dahlstr?m 《The American journal of sports medicine》1989,17(6):766-769
The knee extensor mechanism was examined in 32 male competitive volleyball players (Group V) and in a control group of 49 young adult males (Group C) to evaluate the effects of previous jumping activity on the knee extensor mechanism. Several variables were recorded by means of a structured questionnaire, and by clinical and radiographic examination. The amount of physical activity from the age of 7 years onward was significantly greater in Group V than in Group C. The incidence of anterior knee pain during the year preceding the examination was higher in Group V (31%) than in Group C (6%; P less than 0.01). The most common reason for anterior knee pain in Group V was so-called "jumper's knee." No significant difference between the groups was found in the incidence of clinical symptoms and signs of patellar chondromalacia. There were radiologically detectable soft tissue calcifications at the upper or lower pole of the patella or anterior to the patella in 38% of the subjects in Group V, but no such calcifications were seen in Group C (P less than 0.001). However, persistent symptoms did not correlate with the calcifications. Group V subjects had a slight but significant trend to patella alta when compared to Group C (P less than 0.05) according to the Blackburne and Peel index. 相似文献
7.
In order to evaluate the risks and benefits of continuing established therapy with beta-adrenergic receptor blocking drugs during acute myocardial infarction (AMI), 183 consecutive patients, 63 with (beta-blocker group) and 120 without (control group) this therapy, were studied. Detailed information on previous diseases, present symptoms, established medication, clinical and laboratory findings on admission and during the first 12 hours in the CCU was collected. The incidences of congestive heart failure, hypotension, AV blocks and ventricular arrhythmias were not significantly more common in the control group (8 vs. 28%, p less than 0.01). Thus, continuation of established therapy with beta-adrenergic receptor blocking drugs does not seem to increase the risk of complications after hospital admission for AMI. The reason for the low incidence of inferior wall infarction in the beta-blocker group is not clear but it cannot be excluded that when patients on beta-adrenergic receptor blocking therapy develop an inferior AMI, they may run a greater risk of sudden death. 相似文献
8.
Serotonergic regulation of canine enteric motility (measured as electrical activity) and absorption: physiologic and morphologic evidence 总被引:2,自引:0,他引:2
S Bj?rck H Ahlman A Dahlstr?m S F Phillips K A Kelly 《Acta physiologica Scandinavica》1988,133(2):247-256
To explore the effect of serotonin (5-HT) on enteric electrical activity, transit and absorption, four dogs were prepared with 50 cm jejunal and ileal Vella loops. Electrodes for recording enteric electrical activity were attached to the loops and to the main small bowel. After recovery, both loops were perfused with a [14C-]PEG-glucose-electrolyte solution via the proximal stomas, while effluent was collected from the distal stomas and enteric electrical activity was monitored. Control periods were compared with periods when 5-HT was infused intravenously at a rate of 10 micrograms kg-1 min-1 for 60 min. Serotonin increased the mean +/- SEM % of jejunal and ileal pacesetter potentials with spike potentials from 33 +/- 7% and 35 +/- 9%, before infusion to 63 +/- 4% and 61 +/- 5% after infusion (P less than 0.05). Serotonin also induced distally-migrating bursts of spikes in the incontinuity small bowel. The changes were blocked by atropine, but not by ketanserin. Absorption of water, sodium and glucose from the jejunal and ileal loop and transit through the loops was not changed by 5-HT. At autopsy, all layers of the jejunum and ileum contained varicose nerve fibres with a positive immunoreaction to 5-HT, while positive nerve cell bodies were largely confined to the submucosa. 相似文献
9.
Antisera produced in rabbits against pure fractions of cholinergic vesicles from Narcine brasiliensis were used to study cholinergic organelles in rat motor neurons. The indirect immunofluorescence method was used on perfusion-fixed material. The rats were surgically sympathectomized to remove sympathetic adrenergic and cholinergic nerves from the sciatic nerve. In the intact animal immunoreactive material, likely to represent cholinergic vesicles, was observed in motor endplates, identified by labelling with rhodamine-conjugated α-bungarotoxin or with subsequent acetylcholinesterase staining. The motor perikarya contained very little immunoreactive material. Non-terminal axons were virtually devoid of immunofluorescence in the intact animal. After crushing the sciatic nerve, immunoreactive material (likely to represent axonal cholinergic organelles) accumulated rapidly on both sides of the crush, indicating a rapid bidirectional transport. The transport was sensitive to local application of mitotic inhibitors.The axons which accumulated immunoreactive organelles were motor axons, as demonstrated by various procedures: (1) Cutting of ventral roots prevented accumulation of immunoreactive material in the nerve. (2) Deafferentation did not notably influence accumulations of immunoreactive material. (3) Ligated axons with immunoreactive material were acetylcholinesterase positive when identification was made on the same section; the intra-axonal distribution of immunoreactive material and acetylcholinesterase was not identical, however, and the Narcine antisera did not cross-react with bovine acetylcholinesterase in a solid phase immunoassay. (4) Most axons in ventral roots, but not in dorsal roots, accumulated strongly fluorescent immunoreactive material, while axons in dorsal roots contained weakly fluorescent material. On the other hand, substance P-like immune reactivity was present in many dorsal root axons, but only very rarely in ventral roots.It is suggested that the antisera against Narcine cholinergic vesicles can be used as a marker for cholinergic organelles in the motor neuron, and may be an important tool for studying the axonal cholinergic vesicles. It cannot, however, be used to identify cholinergic structures in unknown locations because it recognizes common antigenic determinants in transmitter organelles of other nerves e.g. adrenergic nerves. The axonal cholinergic organelles may carry important molecules, other than acetylcholine to the nerve endings. 相似文献
10.
A new paradigm for the treatment of ulcerative colitis has recently been presented: Treatment of the mucosa with lidocaine (2%) enemas for prolonged periods. This therapy was introduced based on the hypothesis that hyperreactive autonomic nerves may play a pathogenetic role in the disease. One hundred consecutive patients have now been treated and the results presented. Theproctitis patients all responded to the treatment, despite previous therapeutic failures in more than two-thirds of the cases. They were treated for 3–12 weeks, but 68% had a relapse (observation period 20 months). Of the 49 patients withproctosigmoiditis, two-thirds had chronic symptoms resistant to previous therapy. One of these patients did not respond to lidocaine, but developed fulminant total colitis. The other patient had therapeutic failure with lidocaine but responded well to subsequent cortisone enemas. The patients were treated until the subsets of T-lymphocytes (
and
) disappeared from the mucosa. This occurred in parallel with symptomatic relief and eventual healing in 83% of the patients after treatment for 6–34 weeks. Of all the patients with proctosigmoiditis, 42% presented with recurrent symptoms (observation period 16 months). Of the 17 patients withleft-sided colitis, all went primarily into remission within 2–4 months, but 23% had a relapse (observation period 13 months). The 6 patients withtotal colitis had symptomatic relief and improvement of histology when treated over 3–8 months. One patient had recurrence after 12 months. Treatment with a local anaesthetic in ulcerative colitis is a new approach to mucosal inflammation. The beneficial effects may be due to blockade of certain neural effects, such as epithelial proliferation and shedding and congestion of the mucosal vasculature, with actions on cells of the immune system.This work was supported by grants from the Swedish MRC (2207, 5520), the Assar Gabrielsson Foundation, and the Ulf Widengren Foundation. 相似文献