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   5689篇
  免费   272篇
  国内免费   33篇
耳鼻咽喉   109篇
儿科学   267篇
妇产科学   129篇
基础医学   471篇
口腔科学   234篇
临床医学   505篇
内科学   1339篇
皮肤病学   104篇
神经病学   278篇
特种医学   109篇
外科学   923篇
综合类   349篇
一般理论   4篇
预防医学   361篇
眼科学   186篇
药学   388篇
中国医学   32篇
肿瘤学   206篇
  2024年   4篇
  2023年   86篇
  2022年   279篇
  2021年   397篇
  2020年   184篇
  2019年   201篇
  2018年   228篇
  2017年   151篇
  2016年   185篇
  2015年   244篇
  2014年   286篇
  2013年   286篇
  2012年   429篇
  2011年   398篇
  2010年   232篇
  2009年   195篇
  2008年   304篇
  2007年   288篇
  2006年   298篇
  2005年   276篇
  2004年   229篇
  2003年   215篇
  2002年   169篇
  2001年   47篇
  2000年   50篇
  1999年   35篇
  1998年   28篇
  1997年   18篇
  1996年   19篇
  1995年   13篇
  1994年   15篇
  1993年   7篇
  1992年   24篇
  1991年   19篇
  1990年   19篇
  1989年   17篇
  1988年   14篇
  1987年   15篇
  1986年   8篇
  1985年   11篇
  1984年   6篇
  1983年   7篇
  1980年   5篇
  1979年   6篇
  1977年   5篇
  1974年   6篇
  1973年   4篇
  1972年   4篇
  1970年   5篇
  1969年   4篇
排序方式: 共有5994条查询结果,搜索用时 15 毫秒
31.
Objectives:To elucidate the risk factors for hospital admission among COVID-19 patients with type 2 diabetes mellitus (T2DM).Methods:This retrospective study was conducted at the Prince Sultan Military Medical City, Riyadh, Saudi Arabia between May 2020 and July 2020. Out of 7,260 COVID-19 patients, 920 were identified as T2DM. After the exclusion process, 806 patients with T2DM were included in this analysis. Patients’ data were extracted from electronic medical records. A logistic regression model was performed to estimate the risk factors of hospital admission.Results:Of the total of 806 COVID-19 patients with T2DM, 48% were admitted in the hospital, 52% were placed under home isolation. Older age between 70-79 years (OR [odd ratio] 2.56; p=0.017), ≥80 years (OR 6.48; p=0.001) were significantly more likely to be hospitalized compared to <40 years. Similarly, patients with higher HbA1c level of ≥9% compared to <7%; (OR 1.58; p=0.047); patients with comorbidities such as, hypertension (OR 1.43; p=0.048), cardiovascular disease (OR 1.56; p=0.033), cerebrovascular disease (OR 2.38; p=0.016), chronic pulmonary disease (OR 1.51; p=0.018), malignancy (OR 2.45; p=0.025), chronic kidney disease (CKD) IIIa, IIIb, IV (OR 2.37; p=0.008), CKD V (OR 5.07; p=0.007) were significantly more likely to be hospitalized. Likewise, insulin-treated (OR 1.46; p=0.03) were more likely to require hospital admission compared to non-insulin treated patients.Conclusion:Among COVID-19 patients with diabetes, higher age, high HbA1c level, and presence of other comorbidities were found to be significant risk factors for the hospital admission.  相似文献   
32.
Objectives:To assess the public knowledge and perception about generic medications in Saudi Arabia, and their willingness to use generic medications.Methods:This cross-sectional, online-questionnaire-based study was conducted between May and July 2019, including participants who can read and complete an Arabic online survey. Chi-square test and contingency coefficient were used to investigate differences in different segments of participants and assess the association between knowledge and perception.Results:A total of 397 participants have completed the survey. One-half of them were female, the majority were of young age (<35 years), and 40% of them were buying their medications independently. Only 40.5% of participants had adequate knowledge and 60% of them had positive perception on generics. Participants with higher level of education were more likely to have adequate knowledge (p=0.002) and positive perception (p=0.006). The study found a moderate relationship between knowledge and perception about generics (standardized C=0.35, p<0.001). The country of origin for medications was a significant indicator of quality for two-thirds of participants, and one-half of them believed that local generics can compete with imported ones. About one-half of participants used generics and the majority of them were satisfied with their experience.Conclusion:There is a general lack of knowledge, while having a positive perception on generic medications among the general public in Saudi Arabia. Future studies should focus on strategies to improve it and assess its cost-savings consequences while maintaining quality of care.  相似文献   
33.
The aim of this study was to evaluate the effects of the novel free radical scavenger caffeic acid phenethyl ester (CAPE) on extracorporeal shock wave lithotripsy (ESWL) induced renal impairment. The study was performed using 30 rabbits which were divided into two groups, each exposed to 3,000 shock waves at 18 kV: (1) control group, (2) ESWL+CAPE treated group. Malodialdehyde (MDA), urine N-acetyl--glucosaminidase (NAG) activity, uric acid and white cell counts were used as markers of oxidative stress. Following shock wave exposure there was a significant rise in MDA, NAG and uric acid and white cell counts. CAPE reduced the rise in MDA, NAG, uric acid and white cell counts. Thus CAPE treatment to a great extent prevented the induction of these renal changes. Our results suggest that the antioxidant capacity of the kidney tissue was reduced after ESWL treatment and that the tissue was exposed to oxidant stress. We conclude that CAPE treatment provided significant protection against ESWL induced free radical damage.  相似文献   
34.
Purpose Peritoneal recurrence is not an uncommon cause of death after surgery for gastric cancer, even after surgery with curative intent. This indicates that there is undetected residual disease in the peritoneal cavity. We conducted this study to determine the value of peritoneal and serum carcinoembryonic antigen (CEA) levels and peritoneal washing cytology in predicting the locoregional and distant spread of gastric cancer. Methods We prospectively evaluated 70 consecutive patients with gastric cancer by measuring peritoneal CEA (pCEA) and serum CEA (sCEA) levels and peritoneal washing cytology results, and studying their effect on the histopathologic properties. The effect of the pCEA level on disease-free survival (DFS) and overall survival (OS) was also evaluated in patients treated with curative intent. Results Twenty-one (30%) patients had sCEA levels >10 ng/ml, whereas 25 patients (35.7%) had pCEA levels >10 ng/g protein and 26 patients (37.1%) had positive cytology. The pCEA levels were significantly higher in patients with hepatic metastases (P = 0.034), or serosal (P = 0.028), and peritoneal (P = 0.026) involvement, whereas the sCEA levels were significantly higher only in patients with hepatic metastases (P = 0.04). Similarly, positive cytology was mainly detected in patients with hepatic metastases (P = 0.004). The pCEA levels significantly affected DFS (P = 0.002) and OS (P = 0.01) in 34 patients treated with curative intent. Conclusion Since pCEA levels are more useful for predicting locoregional recurrence, their measurement during surgery may help plan the most appropriate surgical strategy and adjuvant therapy.  相似文献   
35.
In this study we reviewed our experience of hydatid disease of the lung and the liver and discussed the safety and the follow-up results of the one-stage operation. Between 1990 and 2004, 142 patients with pulmonary hydatid disease underwent operation in our clinic. Of these, 27 (19%) patients had cysts located on the dome of the liver, treated with phrenotomy through a right thoracotomy. Hydatid cysts located in the lungs were managed by means of cystotomy. For liver cysts, cystotomy and the inversion of the cavity with sutures was the surgical method of choice, and a drain was left in place. The pulmonary cysts of 12 (8.4%) patients were bilateral and 5 (3.5%) patients had prior surgical treatment of hepatic (n = 1) or pulmonary (n = 4) hydatid cysts. The liver cysts were approached transdiaphragmatically after the lung cysts were excised in 27 (19%) patients. In patients with pulmonary cysts, cystotomy, with or without capitonnage was performed on 123 (86.6%) patients, and wedge resection was performed on 11 (7.7%), segmentectomy was performed on 6 patients (4.2%), and lobectomy was performed on 2 (1.4%) patients. There was no mortality, and only a small number of complications were encountered: empyema in 3, excessive biliary drainage in 2, and bronchopleural fistula in only 1. We suggest that the extraction of pulmonary and hepatic cysts simultaneously through the transthoracic route is a useful and safe surgical technique. This technique also prevents the need for a second operation.  相似文献   
36.

Introduction

Cervicovaginal decubitus ulceration is a well-known complication of advanced pelvic organ prolapse (POP). There is no consensus for its management. This case series describes the outcome of using repeated vaginal packs soaked with oestrogen cream to reduce POP and promote decubitus ulcer healing. We aimed to investigate the speed of ulcer healing and endometrial safety with this regimen.

Methods

This was a retrospective study of patients with stage 3 or 4 POP and intact uterus with decubitus ulcer who were planned for surgery that included hysterectomy after ulcer healing. Vaginal packs are replaced at least biweekly—or more frequently if extruded—until ulcer resolution.

Results

Thirteen patients were studied. Mean age was 69?±?6 years and mean duration of menopause was 19?±?6 years. Nine patients had a single ulcer and four had multiple ulcers. Mean ulcer diameter was 2.8?±?1.5 cm and mean duration for ulcer healing was 26?±?14 days. Hysterectomy and pelvic floor reconstruction was performed a median of 5 (range 0–153) days after ulcer healing was first noted. Histopathological examination of the endometrium following hysterectomy showed three specimens with endocervical hyperplasia; one had concurrent proliferative endometrium, two had simple endometrial hyperplasia and another two had proliferative endometrium.

Conclusion

Oestrogen-soaked vaginal packing is a viable option for managing a decubitus ulcer in advanced POP. We document a measurable impact on the endometrium with this short-term preoperative regimen. Further research is needed to evaluate its efficacy in promoting ulcer healing and endometrial safety.
  相似文献   
37.
Methods:We retrospectively analyzed the patients who underwent RALRP for localized prostate cancer by a single surgeon in our clinic from January 1, 2009–February 1, 2016. Continence was defined as no leakage or use of a safety pad for minimal leakage. The main outcome measure was continence at postoperative week 1 and months 1, 6, and 12.Results:Between 2009 and 2016, 239 patients underwent RALRP for localized prostate disease. Seventy-four patients underwent a standard approach (group 1), 88 had posterior reconstruction (group 2), and 77 had posterior reconstruction with total anatomic restoration (group 3). After 1 week, 24.3% of the patients in group 1 (18/74), 31.8% in group 2 (28/88), and 45.8% in group 3 (33/72) were continent (P = .02). One month after the surgery, continence rates for groups 1, 2, and 3 were 56.7, 67, and 75%, respectively (0.065). After 6 and 12 months, continence rates for groups 1, 2, and 3 were 72.9 and 87.8%, 81.8 and 89.7%, and 84.7 and 91.6%, respectively (P = .178 and .7484).Conclusion:Anatomic restoration improves continence rates in the early period after RALRP. Even though other parameters were higher in the total restoration group, immediate continence (at 1 week) was significantly better.  相似文献   
38.
During lower extremity amputation, the objective is to provide a functional residual limb that permits maximum patient mobility and independence. Preservation of length of the fore part of the foot using salvageable tissue from the amputated part in young patients prevents equines deformity and revision of amputation to a higher level. This can be achieved using tissue available from the amputated part. The spare part concept in reconstructive surgery should be integrated into the trauma algorithm to avoid additional donor site morbidity. Reported here is a young adult patient with crush injuries to both feet, which resulted in amputations. A fasciocutaneous flap raised from one extremity was used to facilitate transmetatarsal amputation stump length preservation of the other extremity.  相似文献   
39.
Caspar W  Papavero L  Nabhan A  Loew C  Ahlhelm F 《Surgical neurology》2003,59(2):101-5; discussion 105-6
BACKGROUND: The widespread use of magnetic resonance imaging (MRI), now the first line investigation for back and leg pain, reveals cystic sacral lesions more often than myelography did in the past. There is agreement that symptomatic perineurial sacral cysts should be treated surgically. However, it is still debated whether the preference should be given to the curative option, consisting of excision of the cyst with duraplasty, or to drainage of the cyst to relieve symptoms. In this retrospective study the efficacy of microsurgical cyst resection with duraplasty is evaluated. METHODS: In 15 patients presenting with pain and neurologic deficits, myelography and/or MRI detected sacral cysts. The clinical features suggested that the space-occupying lesions caused the disturbances. Microsurgical excision of the cyst along with duraplasty or plication of the cyst wall was performed in all the cases. Postoperative care included bed rest and CSF drainage for several days. RESULTS: In 13 out of 15 patients the preoperative radicular pain disappeared after surgery. The 2 patients with motor deficits and the 6 patients with bladder dysfunction recovered completely. In all except 1 of the 10 patients complaining of sensory disturbances a significant improvement was achieved. No complications were observed. CONCLUSION: Microsurgical excision of the cyst combined with duraplasty or plication of the cyst wall is an effective and safe treatment of symptomatic sacral cysts and, in the view of the authors, the method of choice.  相似文献   
40.
PURPOSE: To characterize and compare hepatocellular carcinoma and liver metastases of colorectal metastatic cancer (CMC) by means of quantitative liver perfusion MRI. MATERIALS AND METHODS: Liver perfusion was assessed in 26 HCC and CMC patients (50 nodules) by means of contrast-enhanced MRI. Six perfusion parameters-hepatic perfusion index (HPI), mean transit time (MTT), distribution volume (DV), total blood flow (F(T)), arterial blood flow (F(A)), and portal blood flow (F(P))-were calculated in tumor nodules and the adjacent hepatic parenchyma. RESULTS: The values of F(T), F(A), F(P), and DV were significantly higher in the HCC than in the CMC group, whereas MTT was significantly higher in the CMC group. There was no significant difference in HPI. Arterial blood flow was higher than portal blood flow in the CMC group, while portal blood flow was slightly higher than arterial blood flow in the HCC group. CONCLUSION: The present work describes the use of dynamic MRI to quantitatively assess liver perfusion, which in the future may help studying liver cancers on the basis of their microvascular characteristics.  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