首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11481篇
  免费   700篇
  国内免费   51篇
耳鼻咽喉   302篇
儿科学   294篇
妇产科学   306篇
基础医学   1591篇
口腔科学   424篇
临床医学   928篇
内科学   2676篇
皮肤病学   208篇
神经病学   1272篇
特种医学   233篇
外科学   1078篇
综合类   23篇
一般理论   5篇
预防医学   686篇
眼科学   134篇
药学   731篇
  1篇
中国医学   37篇
肿瘤学   1303篇
  2024年   56篇
  2023年   125篇
  2022年   277篇
  2021年   432篇
  2020年   285篇
  2019年   319篇
  2018年   350篇
  2017年   291篇
  2016年   350篇
  2015年   371篇
  2014年   497篇
  2013年   614篇
  2012年   938篇
  2011年   1054篇
  2010年   521篇
  2009年   455篇
  2008年   796篇
  2007年   724篇
  2006年   650篇
  2005年   685篇
  2004年   620篇
  2003年   573篇
  2002年   490篇
  2001年   69篇
  2000年   45篇
  1999年   66篇
  1998年   94篇
  1997年   67篇
  1996年   52篇
  1995年   48篇
  1994年   38篇
  1993年   35篇
  1992年   33篇
  1991年   23篇
  1990年   19篇
  1989年   19篇
  1988年   20篇
  1987年   11篇
  1986年   25篇
  1985年   17篇
  1984年   10篇
  1983年   11篇
  1982年   11篇
  1980年   6篇
  1979年   7篇
  1978年   5篇
  1976年   4篇
  1974年   4篇
  1972年   5篇
  1967年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.

Objective

Frey's syndrome is a frequent sequela of parotidectomy, causing facial sweating and flushing because of gustatory stimuli. Although botulinum toxin type A has become first-line therapy for Frey's syndrome, some patients become resistant. In this study, we investigated whether another serotype, botulinum toxin type B, might be an effective alternative.

Study Design

Case series with planned data collection.

Setting

Otolaryngology department in a university hospital.

Subjects and Methods

Seven patients aged 30 to 68 years, with severe Frey's syndrome, underwent the Minor test and had 80 U of botulinum toxin type B per cm2 (mean total dose, 2354 U) injected intracutaneously in the mapped area of gustatory sweating. All patients were followed up for 12 months.

Results

One month after treatment, six of the seven patients reported that gustatory sweating and flushing had resolved, and, in the remaining patient, these symptoms had decreased. The Minor test confirmed a significant improvement. The subjective benefits remained stable for six months in four patients and for nine months in the remaining three patients; 12 months after treatment, all patients still reported some improvement.

Conclusion

Botulinum toxin type B afforded symptomatic relief in a small sample of patients with Frey's syndrome and might be considered a potential alternative to botulinum toxin type A.  相似文献   
72.
Conditional mouse knock-outs provide an informative approach to drug target validation where no pharmacological blockers exist or global knock-outs are lethal. Here, we used the Cre-loxP system to delete BDNF in most nociceptive sensory neurons. Conditional null animals were healthy with no sensory neuron loss. However, pain-related behavior was substantially altered. Baseline thermal thresholds were reduced. Carrageenan-induced thermal hyperalgesia was inhibited. Formalin-induced pain behavior was attenuated in the second phase, and this correlated with abolition of NMDA receptor NR1 Ser896/897 phosphorylation and ERK1 and ERK2 activation in the dorsal horn; AMPA receptor phosphorylation (GluR1/Ser831) was unaffected. NGF-induced thermal hyperalgesia was halved, and mechanical secondary hyperalgesia caused by intramuscular NGF was abolished. By contrast, neuropathic pain behavior developed normally. Nociceptor-derived BDNF thus plays an important role in regulating inflammatory pain thresholds and secondary hyperalgesia, but BDNF released only from nociceptors plays no role in the development of neuropathic pain.  相似文献   
73.
Negative pressure wound therapy (NPWT) is becoming routine for the preparation of wounds prior to grafting for wound closure. We have been using both foam- and gauze-based NPWT to prepare wounds for closure prior to skin grafting and have obtained similar proportions of closed wounds; 7/7 for wounds treated with gauze-based NPWT and 11/11 for wounds treated with foam-based NPWT. In our follow-up consultations we observed that skin grafts on the foam-treated patients were less pliable than those on the gauze-treated patients. To assess what the mechanism of this effect might be, we compared the specific details of the treatments of both 11 foam and 7 gauze patients, including depth, location, patients' age and co-morbidity; biopsies of granulation and scar tissue were taken and stained with haematoxylin-eosin and by Masson's trichrome staining and conducted ultrasound analysis of the closed wounds, to see if there were features which explained those effects. All foam patients were treated at -125 mm Hg for an average of 25·9 days before skin grafts were applied. All gauze patients were treated at -80 mm Hg for an average of 24·7 days before skin grafts were applied. Biopsies of granulation tissue prior to skin grafting from five foam and four gauze-based NPWT patients did not reveal any obvious histological differences between the treatments. Ultrasound analysis of the skin-grafted wounds showed an average depth of scar tissue of 18 mm in the wound beds of the foam-treated wounds and 7 mm in the gauze-treated ones. Biopsies taken on the scar tissue after treatment with the gauze showed a minor tissue thickness and disorganisation and less sclerotic components. The findings of this preliminary analysis suggest that foam-based NPWT may induce a thicker layer of scar tissue beneath skin grafts than gauze-based NPWT which might explain a reduced pliability of the reconstructed bed. At present it is unclear which mechanism might be responsible for the difference in pressure (-125 versus -80 mm Hg), either the length of the time taken to reconstruct the wound bed or the intrinsic nature of the foam or gauze on the tissue surface. Prospective studies are necessary to investigate whether these preliminary observations are confirmed and to investigate what the mechanism might be.  相似文献   
74.
The objective of this study was to evaluate a percutaneous extravascular closure device (StarClose, Abbott Vascular, Redwood City, CA) after brachial endovascular approach. From 2004 to 2006, 29 patients received StarClose for brachial closure. Primary endpoints were successful deployment and absence of procedure-related morbidity, secondary endpoints were brachial artery patency on duplex and absence of late (> 30 days) complications. The device was successfully deployed in all patients. In two patients (6.8%) local complications occurred: one patient developed a large hematoma successfully treated with prolonged compression and a second patient presented with brachial artery occlusion requiring operative intervention. After a mean follow-up of 7.5+/-7.2 months, all patients had a palpable brachial/radial pulse; none had signs of infection, distal embolization or neurological deficits. On ultrasound b-mode imaging, the clip was visible as a 4 mm echolucent area at the outer anterior wall of the artery. Based on the peak systolic velocity ratios between the site of StarClose and proximal brachial artery (mean 1.08+/-0.2), none of the studied patients had a significant stenosis at the site of closure. StarClose is safe and effective in providing hemostasis following interventional procedures through the brachial artery; further advantages include patients comfort and early discharge.  相似文献   
75.
Healing of diabetic wounds still remains a critical medical problem. Polydeoxyribonucleotide (PDRN), a compound having a mixture of deoxyribonucleotide polymers, stimulates the A2 purinergic receptor with no toxic or adverse effect. We studied the effects of PDRN in diabetes‐related healing defect using an incisional skin‐wound model produced on the back of female diabetic mice (db+/db+) and their normal littermates (db+/+m). Animals were treated daily for 12 days with PDRN (8 mg/kg/ip) or its vehicle (100 μL 0.9%NaCl). Mice were killed 3, 6, and 12 days after skin injury to measure vascular endothelial growth factor (VEGF) mRNA expression and protein synthesis, to assay angiogenesis and tissue remodeling through histological evaluation, and to study CD31, Angiopoietin‐1 and Transglutaminase‐II. Furthermore, we measured wound breaking strength at day 12. PDRN injection in diabetic mice resulted in an increased VEGF message (vehicle=1.0±0.2 n‐fold vs. β‐actin; PDRN=1.5±0.09 n‐fold vs. β‐actin) and protein wound content on day 6 (vehicle=0.3±0.07 pg/wound; PDRN=0.9±0.1 pg/wound). PDRN injection improved the impaired wound healing and increased the wound‐breaking strength in diabetic mice. PDRN also caused a marked increase in CD31 immunostaining and induced Transglutaminase‐II and Angiopoietin‐1 expression. Furthermore, the concomitant administration of 3,7‐dimethyl‐1‐propargilxanthine, a selective adenosine A2A receptor antagonist, abolished PDRN positive effects on healing. However, 3,7‐dimethyl‐1‐propargilxanthine alone did not affect wound healing in both diabetic mice and normal littermates. These results suggest that PDRN might be useful in wound disorders associated with diabetes.  相似文献   
76.
From February 2002 to December 2005, 424 operations for thyroid disease were performed in our institute. Twenty-two patients were suffering from Basedow's disease, 14 female and 8 male, mean age 36 years (range: 23 to 53 years). In each patient the diagnosis of Basedow's disease was made according to common clinical and laboratory criteria, by evaluation of the thyroid hormones, TSH and TRAB. Before operation all patients were rendered euthyroid with antithyroid drug treatment. Fourteen total thyroidectomies (64%) and 8 near-total thyroidectomies (36%) were performed. Postoperative thyroid function status was evaluated before, 3-4 weeks after the operation and then 3, 6,12 and 24 months postoperatively. The patients were classified as euthyroid (FT3-FT4 and TSH normal), hypothyroid (FT3 and/or FT4 reduced and TSH increased), or hyperthyroid (FT3-FT4 increased). In expert hands, surgical treatment appears to be capable of curing the hyperthyroidism of Basedow's disease effectively, with a very low and largely acceptable risk of complications. Among the different types of surgery, total thyroidectomy and near-total thyroidectomy are equally appropriate to ensure there is no risk of recurrence of hyperthyroidism.  相似文献   
77.
Ectopic breast tissue occurs in 0.4-6% of the general population. Usually, these tissues develop along the embryonic milk line but other sites are reported in the literature. Accessory breasts are commonly axillary and may undergo hormonal changes. Some pathologies of normally positioned breasts can occur in ectopic breast tissue, including carcinoma, and therefore require traditional senological flow-charts and imaging strategies. Supernumerary nipples are generally asymptomatic but may sometimes be associated with urological malformations. In our 10-year experience, 208 patients were observed (138 polythelia and 70 polymastia) and 159 surgical procedures were performed, 97 for supernumerary nipple excision and 67 for accessory breast ablation. Five neoplastic lesions and 25 fibrocystic mastopathies were detected in specimens; normal nipple or breast tissue was found in 129. In view of the potentially malignant transformation of accessory breasts, thorough physician evaluation is needed. Surgery is currently suggested in cases of suspected malignancy, in symptomatic cases and for cosmetic problems.  相似文献   
78.
Stapled hemorrhoidopexy is widely accepted to treat hemorrhoids, but serious complications have been reported. In this prospective audit, we correlated clinical outcome with pathological findings. From January 2003 to April 2007, 94 patients underwent hemorrhoidopexy. Macroscopic appearance of the specimen (shape, size, and depth) was recorded. Microscopically, the presence of columnar, transitional, and squamous epithelium, the involvement of circular/longitudinal smooth muscle, and features of mucosal prolapse were assessed. Clinical outcome was evaluated by a validated questionnaire. Postoperative pain, secretion, and bleeding durations were 12.7 +/− 10.6, 5.6 +/− 9.6, and 6.3 +/− 8.4 days. Patient’s return to work averaged 16.7 +/− 10.7 days. Fissure, skin tags, and anal strictures were observed in 23.4%. Seven patients experienced pain for a significantly longer period of time. All specimens contained columnar mucosa, but 29.8% contained columnar and transitional epithelium and 12.8% contained columnar, anal transitional, and stratified squamous epithelium. Smooth muscle was observed in 62.7%. Pain was significantly increased if transitional epithelium was present in the specimen. No correlation or differences were observed if smooth muscle was present, although postoperative bleeding was more frequent. Hemorrhoidopexy is safe and effective. The specimen should always be sent for pathology examination. Only columnar epithelium should be present and, although the presence of smooth muscle does not influence the outcome in terms of functional results, its presence may play a role in postoperative bleeding. Presented as poster at the Digestive Disease Week, May 2007, Washington, USA  相似文献   
79.

Introduction

Bleeding associated with pelvic fracture mostly comes from the pre-sacral and lumbar venous plexus, or directly from the fracture site. Bleeding as a consequence of arterial lesion is less common (15–20%), and that resulting from lesion of the external iliac artery (EIA) is extremely rare. The mortality rate associated with iliac artery injury ranges from 38% to 72%. Total body CT-scan with contrast medium, angiography or packing can be performed when there is arterial injury. In some cases, embolisation can stop bleeding; however, when there is involvement of the aorta, common iliac artery or EIA, immediate surgery is mandatory. The aim of this study was to report our experience of pelvic fractures associated with EIA lesion.

Materials and methods

Six patients with pelvic fracture and associated rupture of the EIA have been observed at our unit from 2004 to 2009. According to Tile classification there were three cases of type C and two cases of type B fracture. One case was a two-column acetabular fracture. Angiography was performed in all cases.

Results

Three patients died on the day of trauma: two after angiography, and one after surgery of vascular repair. Three patients survived: two underwent a hemipelvectomy, and one underwent hip disarticulation.

Discussion

Haemodynamic instability in patients with pelvic ring fracture is usually because of venous bleeding from the pre-sacral and lumbar plexus, or from the fracture site. Arterial injury is present in around 20% of cases. EIA lesions require immediate surgical treatment to restore blood flow. Depending on the type of injury, vascular surgery can be associated with pelvic fracture stabilisation.

Conclusions

Pelvic ring fracture associated with an EIA lesion is extremely rare, with few cases reported in the literature. Angiography is used for diagnosis, and immediate surgical treatment is required to restore blood flow. Associated injuries and open fracture can lead to fatal complications or amputation. Rates of mortality and severe disability are extremely high.  相似文献   
80.
It is important for clinicians to understand which are the clinical signs, the patient characteristics and the procedures that are related with the occurrence of hypertrophic burn scars in order to carry out a possible prognostic assessment. Providing clinicians with an easy‐to‐ use tool for predicting the risk of pathological scars. A total of 703 patients with 2440 anatomical burn sites who were admitted to the Department of Plastic and Reconstructive Surgery, Burn Center of the Traumatological Hospital in Torino between January 1994 and May 2006 were included in the analysis. A Bayesian network (BN) model was implemented. The probability of developing a hypertrophic scar was evaluated on a number of scenarios. The error rate of the BN model was assessed internally and it was equal to 24·83%. While classical statistical method as logistic models can infer only which variables are related to the final outcome, the BN approach displays a set of relationships between the final outcome (scar type) and the explanatory covariates (patient's age and gender, burn surface area, full‐thickness burn surface area, burn anatomical area and wound‐healing time; burn treatment options such as advanced dressings, type of surgical approach, number of surgical procedures, type of skin graft, excision and coverage timing). A web‐based interface to handle the BN model was developed on the website www.pubchild.org (burns header). Clinicians who registered at the website could submit their data in order to get from the BN model the predicted probability of observing a pathological scar type.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号