全文获取类型
收费全文 | 5109篇 |
免费 | 428篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 115篇 |
妇产科学 | 187篇 |
基础医学 | 551篇 |
口腔科学 | 90篇 |
临床医学 | 641篇 |
内科学 | 837篇 |
皮肤病学 | 117篇 |
神经病学 | 536篇 |
特种医学 | 284篇 |
外国民族医学 | 1篇 |
外科学 | 818篇 |
综合类 | 82篇 |
预防医学 | 349篇 |
眼科学 | 75篇 |
药学 | 457篇 |
中国医学 | 1篇 |
肿瘤学 | 336篇 |
出版年
2021年 | 65篇 |
2020年 | 41篇 |
2019年 | 94篇 |
2018年 | 85篇 |
2017年 | 56篇 |
2016年 | 58篇 |
2015年 | 78篇 |
2014年 | 105篇 |
2013年 | 146篇 |
2012年 | 201篇 |
2011年 | 228篇 |
2010年 | 113篇 |
2009年 | 108篇 |
2008年 | 230篇 |
2007年 | 190篇 |
2006年 | 201篇 |
2005年 | 206篇 |
2004年 | 189篇 |
2003年 | 181篇 |
2002年 | 178篇 |
2001年 | 163篇 |
2000年 | 178篇 |
1999年 | 170篇 |
1998年 | 77篇 |
1997年 | 56篇 |
1996年 | 51篇 |
1995年 | 56篇 |
1994年 | 45篇 |
1993年 | 55篇 |
1992年 | 134篇 |
1991年 | 130篇 |
1990年 | 99篇 |
1989年 | 108篇 |
1988年 | 114篇 |
1987年 | 103篇 |
1986年 | 100篇 |
1985年 | 102篇 |
1984年 | 86篇 |
1983年 | 56篇 |
1982年 | 59篇 |
1981年 | 48篇 |
1980年 | 40篇 |
1979年 | 62篇 |
1978年 | 52篇 |
1977年 | 49篇 |
1974年 | 40篇 |
1973年 | 39篇 |
1972年 | 40篇 |
1971年 | 46篇 |
1970年 | 39篇 |
排序方式: 共有5538条查询结果,搜索用时 15 毫秒
61.
Sahai A Cortes E Seth J Khan MS Panicker J Kelleher C Kessler TM Fowler CJ Dasgupta P 《Current urology reports》2011,12(6):404-412
Lower urinary tract dysfunction can have a significant impact on patients with spinal cord injury. Over the years, many treatment
options have become available. This article reviews the assessment and management of neurogenic detrusor overactivity, with
a particular focus on articles from the recent literature. Recent guidelines on the subject will be discussed. Management
options include antimuscarinics and bladder emptying measures, botulinum toxin A, and neuromodulation in refractory cases
and surgery for intractable cases. Recent and relevant publications in these areas will be summarized and discussed. 相似文献
62.
We report the case of a 20-year-old male competitive football player who was treated for a midsubstance posterior capsule rupture after a posterior dislocation from falling onto his shoulder. Conservative management for 5 months after the injury failed to improve his subjective symptoms, with the primary symptom being activity-related posterior shoulder pain. Advanced imaging findings and physical examination were consistent with posterior instability, thought to be due to a posterior labral tear. At the time of a diagnostic arthroscopy, the patient was found to have an oval-shaped rupture of the capsule that was neither a reverse humeral avulsion of the glenohumeral ligament lesion nor a posterior labral tear. The capsular tear was repaired through an all-arthroscopic technique with nonabsorbable sutures. The patient returned to his previous competitive function, had no pain, and had full motion at final follow-up without recurrence of instability or pain symptoms. 相似文献
63.
Fowler JS Volkow ND Cilento R Wang GJ Felder C Logan J 《Clinical positron imaging : official journal of the Institute for Clinical P.E.T》1999,2(2):71-79
OBJECTIVE: Positron emission tomography (PET) studies in patients with temporal lobe epilepsy have reported that hypometabolism in temporal regions is associated with elevated monoamine oxidase B (MAO B) probably reflecting gliosis. The purpose of this study was to examine a group of head trauma patients suffering from seizures and memory loss to determine whether hypometabolic regions show correspondingly elevated MAO B.METHODS: Seven patients with traumatic brain injury received PET scans with (18)FDG and [(11)C]L-deprenyl-D2 to measure regional glucose metabolism (LCMRglu) and MAO B respectively. Results were compared to a group of nine age-matched healthy controls. Hypometabolic regions were identified and MAO B values corresponding to these brain regions were determined. Averaged brain images for temporal regions for LCMRglu and MAO were also compared.RESULTS: LCMRglu values for temporal regions were reduced in patients relative to normal subjects. Of the 13 hypometabolic brain regions, 6 (46%) showed a corresponding elevation in MAO B. There was a trend for a significant inverse relationship between normalized LCMRglu and normalized MAO B values for medial temporal cortex. Glucose metabolism was significantly higher in lateral than medial temporal regions whereas the pattern was reversed for MAO B.CONCLUSION: MAO B images provide a markedly better delineation of the medial temporal regions than LCMRglu. There was not a consistent inverse relationship between metabolism and MAO B as had been reported in PET studies of epileptogenic temporal lobes with [(11)C]L-deprenyl-D2 and (18)FDG indicating that prospective studies are needed to determine the pathophysiology of hypometabolic lesions in head trauma. 相似文献
64.
BACKGROUND: A study was undertaken to estimate the prevalence of untreated asthma in older adults. METHODS: A cross sectional population based survey of 6000 men and women aged 65 years and over was performed in 21 general practices in north Bristol, south west England. The main outcome measure was untreated asthma as defined by a two stage process comprising a respiratory questionnaire (symptoms suggestive of asthma or doctor diagnosed asthma not receiving respiratory treatment) followed by lung function tests (significant reversibility following bronchodilators or corticosteroids and/or significant within day variability in peak expiratory flow). RESULTS: 4792 of the 6000 participants (80%) completed the respiratory questionnaire and, of those not receiving respiratory treatment, 55 reported a previous doctor diagnosis of asthma and a further 696 had symptoms suggestive of asthma. Lung function testing in 280 of 501 randomly selected individuals from these groups resulted in 38 being defined as having asthma and an estimated population prevalence for untreated asthma of 2.4% (95% CI 1.6% to 3.6%) in men and 1.2% (95% CI 0.7% to 2.1%) in women. Most subjects (84%) with untreated asthma had moderate or severe disease. Untreated asthma was most common in individuals with doctor diagnosed asthma (21%) and those with breathlessness or wheeze (13-20%). CONCLUSION: Untreated asthma in the elderly is a common and important problem. Opportunistic use of appropriate lung function tests in older people with a history of doctor diagnosed asthma or wheeze or breathlessness at rest could identify untreated asthmatics who might benefit from treatment. 相似文献
65.
Studies of HBV replication during acute hepatitis followed by recovery and acute hepatitis progressing to chronic disease 总被引:1,自引:0,他引:1
A.S.F. Lok P. Karayiannis T.P. Jowett M.J.F. Fowler P. Farci J. Monjardino H.C. Thomas 《Journal of hepatology》1985,1(6):671-679
The serologic and viral profiles of 24 patients who presented with acute hepatitis B virus (HBV) infection were studied. Although in rare cases, HBV-DNA was detectable before hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), in the majority the viral proteins appeared first. In acute hepatitis followed by recovery, as IgM anti-HBc (hepatitis B core antigen) titres rose, the level of HBV replication fell and serum transaminases became elevated. In patients progressing to chronic HBV infection, IgM anti-HBc titres rose early, viral replication was initially low but continued to rise as the serum transaminase levels became elevated. 7S IgM anti-HBc, although present in the phase of established chronic HBV infection, was not found in the early phase of the chronic infection. Thus this antibody appears to be a consequence of, rather than a causative factor in, chronic HBV infection. 相似文献
66.
Alexander Aarvold James O. Smith Edward R. Tayton Caroline J. Edwards Darren J. Fowler Edward D. Gent Richard O. C. Oreffo 《Journal of children's orthopaedics》2012,6(4):339-346
Purpose
The pathogenesis of unicameral bone cysts (UBCs) remains largely unknown. Osteoclasts have been implicated, but the role of osteoblastic cells has, to date, not been explored. This study investigated the pathophysiology of UBCs by examining the interactions between the cyst fluid and human bone marrow stromal cells (hBMSCs) and the effect of the fluid on osteogenesis.Methods
Fluid was aspirated from two UBCs and analysed for protein, electrolyte and cytokine levels. Graded concentrations of the fluid were used as culture media for hBMSCs to determine the effects of the fluid on hBMSC proliferation and osteogenic differentiation. The fibrocellular lining was analysed histologically and by electron microscopy.Results
Alkaline phosphatase (ALP) staining of hBMSCs that were cultured in cyst fluid demonstrated increased cell proliferation and osteogenic differentiation compared to basal media controls. Biochemical analysis of these hBMSCs compared to basal controls confirmed a marked increase in DNA content (as a marker of proliferation) and ALP activity (as a marker of osteogenic differentiation) which was highly significant (p < 0.001). Osteoclasts were demonstrated in abundance in the cyst lining. The cyst fluid cytokine profile revealed levels of the pro-osteoclast cytokines IL-6, MIP-1α and MCP-1 that were 19×, 31× and 35× greater than those in reference serum.Conclusions
Cyst fluid promoted osteoblastic growth and differentiation. Despite appearing paradoxical that the cyst fluid promoted osteogenesis, osteoblastic cells are required for osteoclastogenesis through RANKL signalling. Three key cytokines in this pathway (IL-6, MIP-1α, MCP-1) were highly elevated in cyst fluid. These findings may hold the key to the pathogenesis of UBCs, with implications for treatment methods. 相似文献67.
Natural orifice transluminal endoscopic surgery (NOTES) is considered the new frontier for minimally invasive surgery. NOTES
procedures such as peritoneoscopy, splenectomy, and cholecystectomy in animal models have been described. The aim of our experiment
was to determine the feasibility and technical aspects of a new endoluminal surgical procedure. After approval from Columbia’s
IACUC, a transvaginal laparoscopically assisted endoscopic cholecystectomy was performed on four 30 kg Yorkshire pigs. The
first step was to insert a 1.5 cm endoscope into the vagina under direct laparoscopic vision. Then the gallbladder was reached
and, with the help of a laparoscopic grasper to hold up the gallbladder, the operation was performed. At the end of the procedure
the gallbladder was snared out through the vagina attached to the endoscope. There were no intraoperative complications such
as bleeding, common bile duct or endo-abdominal organ damage. Total operative time ranged between 110 and 155 min. Based on
our experience in the porcine model, we believe that a transvaginal endoscopic cholecystectomy is feasible in humans.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
68.
Mano J. Thubrikar Michel R. Labrosse Kenton J. Zehr Francis Robicsek Geoffrey G. Gong Brett L. Fowler 《European journal of cardio-thoracic surgery》2005,28(6):850-855
Objective: Valve-sparing surgery can be used in patients with dilated aortic roots and aortic insufficiency (AI) but has not become a common practice, in part because the spared valve may be incompetent. Our goal was to study how the dimensions of the aortic root and leaflets have changed in such patients. Methods: Fourteen patients with dilated aortic root and AI were examined by transesophageal echocardiography. The annulus diameter, sinotubular junction (STJ) diameter, sinus height, leaflet free-edge length, and leaflet height were measured. Correlations among these dimensions and with the AI grades were explored. Measurements were also made in 19 normal human aortic valves from silicone molds. Results: There was no evident change in the average diameter of the annulus between the normal valves and those in the dilated aortic roots. The STJ diameter was obviously increased in the dilated aortic roots; the aortic sinuses also appeared to be taller and the leaflets larger than normal. The leaflet free-edge length, the leaflet height, and the sinus height were found to increase with the dilated STJ diameter. The degree of AI was not found to correlate well with any of the dimensions measured. Conclusions: The dimensions of the leaflets may change parallel to aortic root dilatation with AI. Therefore, during valve sparing, it may be necessary to correct both the dilatation of the root and the leaflet free-edge length to achieve a competent valve. 相似文献
69.
R L Rietschel C G Mathias J S Taylor F J Storrs E F Sherertz M Pratt J G Marks H I Maibach A F Fransway J F Fowler V A DeLeo D V Belsito 《American Journal of Contact Dermatitis》2001,12(2):72-76
BACKGROUND: The interplay between the occupational environment and worker's skin can result in contact dermatitis of both irritant and allergic types. Other forms of dermatitis can also be influenced by occupational exposures. OBJECTIVE: The aim of this study is to compare the occupations and allergens of occupational contact dermatitis cases with nonoccupational contact dermatitis cases. METHODS: Diagnostic patch testing with allergens of the North American Contact Dermatitis Group and occupational coding by the National Institute for Occupational Safety and Health methods. RESULTS: Of 2,889 patients referred for evaluation of contact dermatitis, 839 patients (29%) were found to have occupational contact dermatitis. Of the 839 cases deemed occupational, 455 cases (54%) were primarily allergic in nature and 270 cases (32%) were primarily irritant in nature. The remaining 14% were diagnoses other than contact dermatitis, aggravated by work. The occupation most commonly found to have allergic contact dermatitis was nursing. Allergens strongly associated with occupational exposure were thiuram, carbamates, epoxy, and ethylenediamine. CONCLUSION: Some contact allergens are more commonly associated with occupational contact dermatitis. Nursing and nursing support are occupations most likely to be overrepresented in contact dermatitis clinics. 相似文献
70.
Kömüves LG Schmuth M Fowler AJ Elias PM Hanley K Man MQ Moser AH Lobaccaro JM Williams ML Mangelsdorf DJ Feingold KR 《The Journal of investigative dermatology》2002,118(1):25-34
Liver X receptor-alpha and -beta are members of the nuclear hormone receptor superfamily that heterodimerize with retinoid X receptor and are activated by oxysterols. In recent studies we found that treatment of cultured human keratinocytes with oxysterolstimulated differentiation, as demonstrated by increased expression of involucrin and transglutaminase, and inhibited proliferation. The aims of this study were to determine: (i) whether oxysterols applied topically to the skin of mice induce differentiation in normal epidermis; (ii) whether this effect is mediated via liver X receptor-alpha and/or liver X receptor-beta; and (iii) whether oxysterols normalize epidermal morphology in an animal model of epidermal hyperplasia. Topical treatment of normal hairless mice with 22(R)-hydroxycholesterol or 24(S),25-epoxycholesterol resulted in a decrease in epidermal thickness and a decrease in keratinocyte proliferation assayed by proliferating cell nuclear antigen staining. Moreover, oxysterol treatment increased the levels of involucrin, loricrin, and profilaggrin protein and mRNA in the epidermis, indicating that oxysterols stimulate epidermal differentiation. Additionally, topical oxysterol pretreatment improved permeability barrier homeostasis. Whereas liver X receptor-alpha-/- mice revealed no alterations in epidermal differentiation, the epidermis was thinner in liver X receptor-beta-/- mice than in wild-type mice, with a reduced number of proliferating cell nuclear antigen positive cells and a modest reduction in the expression of differentiation markers. Topical oxysterol treatment induced differentiation in liver X receptor-alpha-/- mice whereas in liver X receptor-beta-/- mice there was no increase in the expression of differentiation markers. Whereas both liver X receptor-alpha and liver X receptor-beta are expressed in cultured human keratinocytes and in fetal rat skin, only liver X receptor-beta was observed on northern blotting in adult mouse epidermis. Finally, treatment of hyperproliferative epidermis with oxysterols restored epidermal homeostasis. These studies demonstrate that epidermal differentiation is regulated by liver X receptor-beta and that oxysterols, acting via liver X receptor-beta, can induce differentiation and inhibit proliferation in vivo. The ability of oxysterols to reverse epidermal hyperplasia suggests that these agents could be beneficial for the treatment of skin disorders associated with hyperproliferation and/or altered differentiation. 相似文献