全文获取类型
收费全文 | 10512篇 |
免费 | 1152篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 73篇 |
儿科学 | 352篇 |
妇产科学 | 354篇 |
基础医学 | 1515篇 |
口腔科学 | 186篇 |
临床医学 | 1155篇 |
内科学 | 2128篇 |
皮肤病学 | 103篇 |
神经病学 | 797篇 |
特种医学 | 550篇 |
外科学 | 1461篇 |
综合类 | 332篇 |
一般理论 | 7篇 |
预防医学 | 1097篇 |
眼科学 | 106篇 |
药学 | 863篇 |
中国医学 | 4篇 |
肿瘤学 | 607篇 |
出版年
2021年 | 145篇 |
2020年 | 102篇 |
2019年 | 146篇 |
2018年 | 149篇 |
2017年 | 136篇 |
2016年 | 126篇 |
2015年 | 168篇 |
2014年 | 247篇 |
2013年 | 345篇 |
2012年 | 473篇 |
2011年 | 514篇 |
2010年 | 279篇 |
2009年 | 263篇 |
2008年 | 425篇 |
2007年 | 438篇 |
2006年 | 435篇 |
2005年 | 417篇 |
2004年 | 398篇 |
2003年 | 386篇 |
2002年 | 379篇 |
2001年 | 321篇 |
2000年 | 338篇 |
1999年 | 309篇 |
1998年 | 167篇 |
1997年 | 158篇 |
1996年 | 164篇 |
1995年 | 128篇 |
1994年 | 138篇 |
1993年 | 131篇 |
1992年 | 233篇 |
1991年 | 260篇 |
1990年 | 226篇 |
1989年 | 217篇 |
1988年 | 233篇 |
1987年 | 246篇 |
1986年 | 225篇 |
1985年 | 217篇 |
1984年 | 170篇 |
1983年 | 150篇 |
1982年 | 105篇 |
1981年 | 105篇 |
1979年 | 109篇 |
1978年 | 94篇 |
1977年 | 87篇 |
1976年 | 82篇 |
1975年 | 88篇 |
1973年 | 89篇 |
1972年 | 85篇 |
1971年 | 77篇 |
1970年 | 72篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Invasive pulmonary haemangiomatosis 总被引:1,自引:0,他引:1
Invasive pulmonary haemangiomatosis is a recently described disease in which exceedingly thin-walled vessels of capillary or venous dimensions infiltrate the lung parenchyma and pulmonary blood vessels. The angiomatous vessels, of obscure origin, infiltrate the media and intima of muscular pulmonary arteries, pulmonary veins and venules. The occlusion of the veins and venules by the thin-walled vessels, and the reactive intimal fibrosis they provoke, leads to pulmonary capillary dilatation, collections of intra-alveolar siderophages, fibrosis of alveolar walls and osseous nodules. This secondary pulmonary veno-occlusive disease in turn leads to hypertensive pulmonary vascular disease. Hence invasive pulmonary haemangiomatosis represents a fourth cause of 'unexplained pulmonary hypertension', the other three being unexplained plexogenic pulmonary arteriopathy, recurrent pulmonary thromboembolism, and pulmonary veno-occlusive disease. Two previously reported cases of invasive pulmonary haemangiomatosis presented with recurrent haemoptysis and the gradual development of chronic respiratory insufficiency associated with diffuse infiltrates in the chest radiograph. In one of these cases a haemothorax had developed. Such clinical features may be of importance in coming to the correct diagnosis. 相似文献
132.
Background : Appendicectomy is a common emergency operation, after which major complications are uncommon, however when they do occur they are a major cause of concern to patient and surgeon. This study aims to determine the incidence and risk factors for post-appendicectomy intra-abdominal abscess formation. Method : A retrospective review was undertaken of all appendicectomies undertaken in Christchurch Hospital between 1 January and 31 December 1995. Appendicectomies were identified from a database of histology. The patients’ notes were reviewed and the surgical approach, histological diagnosis and postoperative complications identified. Results : A total of 417 appendicectomies was identified of which 331 were open, 66 laparoscopic, and 20 undertaken at laparotomy. Mean day stays for each group were 4.4, 4.2 and 11.5 days, respectively. The percentages of patients with acute appendicitis in each group were 87, 58 and 35%. Histologically the appendix was inflamed in 80% (334) of patients (acute 232, chronic 15, perforated 56 and gangrenous 24). There were six postoperative intra-abdominal abscesses (1.4%), all occurring in the open appendicectomy group when the histology was either perforated or gangrenous appendicitis (P < 0.001). There were no cases of postoperative abscess formation following laparoscopic appendicectomy. All cases of postoperative intra-abdominal abscess were associated with perforated and/or gangrenous appendicitis (P < 0.001). The incidence of intra-abdominal abscesses was 7.5% with a perforated and/or gangrenous appendix. There were two cases of iatrogenic perforation following laparoscopic appendicectomy. Conclusion : The incidence of intra-abdominal abscess is 1.4% of all appendicectomies. The only identified risk factor for development of post-appendicectomy intra-abdominal abscess was the underlying pathology of gangrenous or perforated appendicitis. 相似文献
133.
The objective of this paper was to determine the time course and extent of platinum uptake into human malignant glioma tissue. An intraoperative, intravenous infusion of carboplatin was given to nine patients (seven glioblastoma and two anaplastic glioma) undergoing tumour excision. Carboplatin dosage was calculated individually to achieve a target systemic free carboplatin exposure. Tumour and peritumoural tissue was harvested at timed intervals following carboplatin administration. Plasma and tumour platinum concentrations were measured by graphite furnace flameless atomic absorption spectrophotometry. Histological examination was also performed on a piece of each tissue sample. The mean carboplatin dose administered was 783, SEM 56 mg (range 485-903). Plasma pharmacokinetics showed a typical elimination curve. The mean peak plasma platinum concentration was 44, SEM 5 micrograms/ml (range 27-74). The mean total elemental plasma platinum area under the curve (AUC) was 9.0, SEM 1.4 mg/ml/min. Platinum was detected in 61 tumour samples, the mean peak concentration being 13 SEM 2 micrograms/g (range 5-21). Platinum was also detected in peritumoural brain and necrotic tumour. No correlation was apparent between the degree of necrosis in each tumour specimen and tumour platinum concentration. Platinum concentrations achieved in tumour were similar to levels that would be cytotoxic for glioma cells in vitro. The results of this study have implications for future studies using capillary permeability modifying agents as adjuncts to brain tumour chemotherapy. 相似文献
134.
Daniel J A Connolly Zo? C Traill Helen S Reid Susan J Copley Daniel J Nolan 《Clinical radiology》2002,57(1):29-32
AIM: To determine retrospectively the sensitivity and specificity of the double contrast barium enema (DCBE) as performed in one institution for the detection of colorectal carcinoma. SUBJECTS AND METHODS: Eight hundred and eighty barium enema reports were reviewed of consecutive adult patients who underwent DCBE and also had hospital case notes with a minimum follow up of two years, a later diagnostic colonoscopy, or operative and histological findings. RESULTS: Seventy-four true positive cases of colorectal carcinoma diagnosed at DCBE were confirmed at surgery and histological examination. There were four false positive diagnoses of carcinoma at DCBE. Eight false negative cases at DCBE were demonstrated within a two-year follow-up period. The sensitivity of the DCBE for detecting colorectal carcinoma was therefore 90.2% and the specificity was 99.5%. CONCLUSION: DCBE is a sensitive and highly specific investigation for the detection of colorectal carcinoma. 相似文献
135.
Flexor tendon sheath infections of the hand must be diagnosed and treated expeditiously to avoid poor clinical outcomes. Knowledge of the sheath's anatomy is essential for diagnosis and to help to guide treatment. The Kanavel cardinal signs are useful for differentiating conditions with similar presentations. Management of all but the earliest cases of pyogenic flexor tenosynovitis consists of intravenous antibiotics and surgical drainage of the sheath with open or closed irrigation. Closed irrigation may be continued postoperatively. Experimental data from an animal study have shown that local administration of antibiotics and/or corticosteroids can help lessen morbidity from the infection; however, additional research is required. Despite aggressive and prompt antibiotic therapy and surgical intervention, even otherwise healthy patients can expect some residual digital stiffness following flexor tendon sheath infection. Patients with medical comorbidities or those who present late with advanced infection can expect poorer outcomes, including severe digital stiffness or amputation. 相似文献
136.
Boonen S Ferrari S Miller PD Eriksen EF Sambrook PN Compston J Reid IR Vanderschueren D Cosman F 《Journal of bone and mineral research》2012,27(5):963-974
Osteoporosis may be a lifelong condition. Robust data regarding the efficacy and safety of both long-term osteoporosis therapy and therapy discontinuation are therefore important. A paucity of clinical trial data regarding the long-term antifracture efficacy of osteoporosis therapies necessitates the use of surrogate endpoints in discussions surrounding long-term use and/or discontinuation. Long-term treatment (beyond 3-4 years) may produce further increases in bone mineral density (BMD) or BMD stability, depending on the specific treatment and the skeletal site. Bisphosphonates, when discontinued, are associated with a prolonged reduction in bone turnover markers (BTMs), with a very gradual increase to pretreatment levels within 3 to 60 months of treatment cessation, depending on the bisphosphonate used and the prior duration of therapy. In contrast, with nonbisphosphonate antiresorptive agents, such as estrogen and denosumab, BTMs rebound to above pretreatment values within months of discontinuation. The pattern of BTM change is generally mirrored by a more or less rapid decrease in BMD. Although the prolonged effect of some bisphosphonates on BTMs and BMD may contribute to residual benefit on bone strength, it may also raise safety concerns. Adequately powered postdiscontinuation fracture studies and conclusive evidence on maintenance or loss of fracture benefit is lacking for bisphosphonates. Similarly, the effects of rapid reversal of bone turnover upon discontinuation of denosumab on fracture risk remain unknown. Ideally, studies evaluating the effects of long-term treatment and treatment discontinuation should be designed to provide head-to-head "offset" data between bisphosphonates and nonbisphosphonate antiresorptive agents. In the absence of this, a clinical recommendation for physicians may be to periodically assess the benefits/risks of continuation versus discontinuation versus alternative management strategies. 相似文献
137.
R E Brolin MD JH Gorman MD RC Gorman MD AJ Petschenik M D LJ Bradley MS RD HA Kenler PhD RP Cody Pb D 《Journal of gastrointestinal surgery》1998,2(5):436-442
Although iron, vltamm B12, and folate deficiency have been well documented after gastric bypass operations performed for morbid obesity, there is surprisingly
little information on either the natural course or the treatment of these deficiencies in Roux-en-Y gastric bypass (RYGB)
patients Durmg a l0-year period, a complete blood count and serum levels of iron, total iron-binding capacity, vltamin B12, and folate were obtained in 348 patients preoperatively and postoperatively at 6-month intervals for the first 2 years,
then annually thereafter The principal objectives of this study were to determine how readily patients who developed metabolic
deficiencies after Roux-en-Y gastric bypass responded to postoperative supplements of the deficient micronutrient and to learn
whether the risk of developmg these deficiencies decreases over time Hemoglobin and hematocrit levels were slgnificantly decreased
at all postoperative intervals in comparison to preoperative values Moreover, at each successive interval through 5 years,
hemoglobin and hematocrit were decreased signifiantly compared to the preceding interval Folate levels were significantly
increased compared to preoperative levels at all time intervals Iron and vltamin B12 levels were lower than preoperative measurements and remained relatively stable postoperatively Half of the low hemoglobin
levels were not associated with iron deficiency Taking multivltamin supplements resulted in a lower incidence of folate deficiency
but did not prevent iron or vitamin B12 deficiency Oral supplementation of iron and vitamin B12 corrected defiaencies in 43% and 81% of cases, respectively Folate deficiency was almost always corrected with multivitamins
alone No patient had symptoms that could be attributed to either vitamin B12 or folate deficiency Conversely, many patients had symptoms of iron deficiency and anenua Lack of symptoms of vitamin B12 and folate deficiency suggests that these deficiencies are not clinically important after RYGB Conversely, iron deficiency
and anemia are potentially serious problems after RYGB, particularly in younger women Hence we recommend prophylactic oral
iron supplements to premenopausal women who undergo RYGB 相似文献
138.
Ban C. H. Tsui Susan Reid Sunil Gupta Ramona Kearney Tom Mayson Brendan Finucane 《Journal canadien d'anesthésie》1998,45(5):397-401
Purpose
To evaluate a rapid and time-saving precurarization technique using rocuronium to prevent succinylcholine-induced myalgia.Method
In a prospective, double blind randomized study, 42 ASA 1–2 patients were assigned to one of three pretreatment groups: 0.01 ml · kg?1 normal saline, 0.1 mg · kg?1 atracurium, and 0.1 mg · kg?1 rocuronium. Anaesthesia commenced with 1.5 μg · kg?1 fentanyl and 0.5 mg · kg?1 lidocaine at time zero. Pretreatment was administered 60 sec later, followed by 2.5 mg · kg?1 propofol. At 90 sec, 1.5 mg · kg?1 succinylcholine was injected and 30 sec later, the trachea was intubated and the ease of intubation was graded. The patient was observed for the presence and severity of fasciculations. Myalgias were recorded on postoperative days 1, 2 and 7.Results
The incidence of fasciculations in the rocuronium group (21.4%) was lower (P < 0.001) than atracurium (78.5%) or placebo (92.8%) groups. On postoperative day 1, the incidence of postoperative myalgia in the rocuronium group (14.2%) was less than the placebo group (78.2%;P < 0.002) and atracurium group (85.7%;P < 0.001). The incidence of myalgia in the rocuronium group (7.1%) was lower than in the placebo group (78.5%;P < 0.001) but not different from the atracurium group (42.8%;P = 0.077) on postoperative day 2. On postoperative day 7, there was no difference among the three groups. Fasciculations were related to post-operative myalgia. There was no difference in intubating conditions among the three groups.Conclusion
Rocuronium pretreatment given just before induction of anaesthesia with propofol reduces fasciculations and succinylcholine-induced myalgia. 相似文献139.
Allison N. Martin Deepanjana Das Florence E. Turrentine Todd W. Bauer Reid B. Adams Victor M. Zaydfudim 《Journal of gastrointestinal surgery》2016,20(9):1554-1564
Background
Morbidity after gastrectomy remains high. The potentially modifiable risk factors have not been well described. This study considers a series of potentially modifiable patient-specific and perioperative characteristics that could be considered to reduce morbidity and mortality after gastrectomy.Methods
This retrospective cohort study includes adults in the ACS NSQIP PUF dataset who underwent gastrectomy between 2011 and 2013. Sequential multivariable models were used to estimate effects of clinical covariates on study outcomes including morbidity, mortality, readmission, and reoperation.Results
Three thousand six hundred and seventy-eight patients underwent gastrectomy. A majority of patients had distal gastrectomy (N?=?2,799, 76.1 %) and had resection for malignancy (N?=?2,316, 63.0 %). Seven hundred and ninety-eight patients (21.7 %) experienced a major complication. Reoperation was required in 290 patients (7.9 %). Thirty-day mortality was 5.2 %. Age (OR?=?1.01, 95 % CI?=?1.01–1.02, p?=?0.001), preoperative malnutrition (OR?=?1.65, 95 % CI?=?1.35–2.02, p?<?0.001), total gastrectomy (OR?=?1.63, 95 % CI?=?1.31–2.03, p?<?0.001), benign indication for resection (OR?=?1.60, 95 % CI?=?1.29–1.97, p?<?0.001), blood transfusion (OR?=?2.57, 95 % CI?=?2.10–3.13, p?<?0.001), and intraoperative placement of a feeding tubes (OR?=?1.28, 95 % CI?=?1.00–1.62, p?=?0.047) were independently associated with increased risk of morbidity. Association between tobacco use and morbidity was statistically marginal (OR?=?1.23, 95 % CI?=?0.99–1.53, p?=?0.064). All-cause postoperative morbidity had significant associations with reoperation, readmission, and mortality (all p?<?0.001).Conclusions
Mitigation of perioperative risk factors including smoking and malnutrition as well as identified operative considerations may improve outcomes after gastrectomy. Postoperative morbidity has the strongest association with other measures of poor outcome: reoperation, readmission, and mortality.140.
Helen M. Macdonald Susan A. New Marion K. Campbell David M. Reid 《Osteoporosis international》2005,16(2):163-171
Weight is recognized as an important factor in determining an individuals risk of osteoporosis. However, little is known about whether weight or weight change influences bone loss around the time of the menopause, and the relationship with energy intake and physical activity level remains largely undefined. Healthy premenopausal women (1,064 selected from a random population of 5,119 women aged 45–54 years at baseline) each had bone mineral density (BMD), weight and height measurements, and completed a food frequency and physical activity questionnaire. Of the original participants, 907 women (85.2%) returned 6.3 ± 0.6 years later for repeat BMD measurements, and 896 women completed the questionnaires. Bone loss at the hip (FN) and spine (LS) occurred before the menopause. Weight change rather than weight was associated with FN BMD loss (r=0.102, p=0.002), but weight at follow-up was associated with LS BMD change (r=0.105, p=0.002). Although an increase in physical activity level (PAL) appeared to be beneficial for FN BMD in women who were heavy weight gainers, PAL was associated with increased LS BMD loss in women who lost weight. For current HRT users, neither weight nor weight change was associated with change in BMD. Postmenopausal women not taking HRT should be made aware that low body weight or losing weight during this particularly vulnerable period may worsen bone loss. 相似文献