全文获取类型
收费全文 | 5820篇 |
免费 | 368篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 92篇 |
儿科学 | 137篇 |
妇产科学 | 63篇 |
基础医学 | 710篇 |
口腔科学 | 113篇 |
临床医学 | 429篇 |
内科学 | 1314篇 |
皮肤病学 | 115篇 |
神经病学 | 323篇 |
特种医学 | 167篇 |
外国民族医学 | 2篇 |
外科学 | 956篇 |
综合类 | 109篇 |
一般理论 | 9篇 |
预防医学 | 416篇 |
眼科学 | 170篇 |
药学 | 518篇 |
中国医学 | 51篇 |
肿瘤学 | 522篇 |
出版年
2023年 | 68篇 |
2022年 | 195篇 |
2021年 | 305篇 |
2020年 | 144篇 |
2019年 | 171篇 |
2018年 | 224篇 |
2017年 | 151篇 |
2016年 | 165篇 |
2015年 | 220篇 |
2014年 | 287篇 |
2013年 | 254篇 |
2012年 | 447篇 |
2011年 | 484篇 |
2010年 | 313篇 |
2009年 | 229篇 |
2008年 | 339篇 |
2007年 | 337篇 |
2006年 | 322篇 |
2005年 | 306篇 |
2004年 | 259篇 |
2003年 | 264篇 |
2002年 | 205篇 |
2001年 | 57篇 |
2000年 | 41篇 |
1999年 | 40篇 |
1998年 | 51篇 |
1997年 | 28篇 |
1996年 | 37篇 |
1995年 | 21篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 22篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 4篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1971年 | 5篇 |
排序方式: 共有6216条查询结果,搜索用时 11 毫秒
31.
Dr. Richard W. Shallman M.D. Marvin Kuehner M.D. Gail H. Williams M.D. Syed Sajjad M.D. Richard Sautter M.D. 《Diseases of the colon and rectum》1985,28(10):732-737
Benign ulceration of the cecum is an uncommon lesion. Most cases are diagnosed intraoperatively and most authors have advocated
right hemicolectomy due to the difficulty in differentiating benign from malignant lesions. Recently colonoscopic diagnosis
and conservative treatment have been reported. We describe six cases of cecal ulcer ranging from asymptomatic lesions diagnosed
at colonoscopy and healing with conservative management to perforated ulcers with intra-abdominal abscesses requiring right
hemicolectomy. A selective approach to patient management is advocated, including stapler wedge cecectomy with frozen section
diagnosis to avoid extensive bowel resection and retain the ileocecal valve. 相似文献
32.
Antegrade crystalloid cardioplegia vs antegrade/retrograde cold and tepid blood cardioplegia in CABG. 总被引:3,自引:0,他引:3
A M Elwatidy M A Fadalah E A Bukhari K A Aljubair A Syed A K Ashmeg M R Alfagih 《The Annals of thoracic surgery》1999,68(2):447-453
BACKGROUND: This study evaluated the myocardial protective strategies in isolated coronary bypass surgeries. METHODS: One hundred and twenty-eight patients were prospectively randomized to 3 techniques of myocardial protection; group I (n = 47) antegrade/retrograde tepid blood cardioplegia, group II (n = 40) antegrade/retrograde cold blood cardioplegia with topical cooling, group III (n = 41) antegrade crystalloid cardioplegia with topical cooling. RESULTS: The incidence of spontaneous defibrillation was significantly higher in group I (p < 0.001) while the incidence of low cardiac output was not different between the 3 groups. The incidence of ventricular arrhythmia was higher in group III (p < 0.016 group III vs I). There was no significant statistical difference in hemodynamic recovery between the 3 groups. CK-MB levels were significantly lower in group I versus the other 2 groups, (p = 0.0013, 0.04). Acid release and oxygen extraction were higher in group II than in group I (p = 0.06) during cardioplegia and reperfusion. Lactate release was less in group I at the release of aortic cross-clamp, and reperfusion. There was no significant difference between the 3 groups in ICU stay, ventilation time, or hospital complications. CONCLUSIONS: Tepid blood cardioplegia showed superiority in metabolic and functional recovery, whereas crystalloid cardioplegia had the highest incidence of postoperative arrhythmias. There was no significant statistical difference between the 3 groups in hospital mortality and morbidity. 相似文献
33.
Kaitlyn J. Kelly Emily Winslow David Kooby Neha L. Lad Alexander A. Parikh Charles R. Scoggins Syed Ahmad Robert C. Martin Shishir K. Maithel H. J. Kim Nipun B. Merchant Clifford S. Cho Sharon M. Weber 《Journal of gastrointestinal surgery》2013,17(7):1209-1217
Introduction
Current National Comprehensive Cancer Network guidelines recommend neoadjuvant therapy for borderline resectable pancreatic adenocarcinoma to increase the likelihood of achieving R0 resection. A consensus has not been reached on the degree of venous involvement that constitutes borderline resectability. This study compares the outcome of patients who underwent pancreaticoduodenectomy with or without vein resection without neoadjuvant therapy.Methods
A multi-institutional database of patients who underwent pancreaticoduodenectomy was reviewed. Patients who required vein resection due to gross vein involvement by tumor were compared to those without evidence of vein involvement.Results
Of 492 patients undergoing pancreaticoduodenectomy, 70 (14 %) had vein resection and 422 (86 %) did not. There was no difference in R0 resection (66 vs. 75 %, p?=?NS). On multivariate analysis, vein involvement was not predictive of disease-free or overall survival.Conclusion
This is the largest modern series examining patients with or without isolated vein involvement by pancreas cancer, none of whom received neoadjuvant therapy. Oncological outcome was not different between the two groups. These data suggest that up-front surgical resection is an appropriate option and call into question the inclusion of isolated vein involvement in the definition of “borderline resectable disease.” 相似文献34.
35.
Ramakrishna Narra Shaheen Syed Nethula Sowjanya Satyanarayana Veeragandham 《Radiology Case Reports》2022,17(5):1506
Adrenal cortical carcinoma (ACC) is a rare, aggressive endocrine malignancy with a reported incidence of 1.0-2.0 cases per million population and a poor prognosis due to metastatic spread. About 25% of cases of ACC present with metastases at the time of diagnosis. Metastatic spread of ACC commonly involves lungs, liver, kidney, peritoneum, lymph nodes, venous extension to the renal vein or inferior vena cava and bone. We report a case of a 47-year-old male with a nonfunctioning ACC with metastases to skeletal muscle (subscapularis, paraspinal, iliacus and gluteus maximus muscle) in addition to metastasis to the lung, which was not reported in the literature. Unfortunately, the patient expired prior to the surgery due to respiratory distress. 相似文献
36.
37.
Lileswar Kaman Syed Nusrath Divya Dahiya Ajay Duseja Sameer Vyas Vikas Saini 《Updates in surgery》2012,64(4):257-264
Pancreatic fistula is a major cause of morbidity and mortality after pancreaticoduodenectomy. External drainage of pancreaticojejunostomy anastomosis with a stent is used to reduce the rate of pancreatic fistula. This study compares the rates of pancreatic fistula between external stent drainage versus no-stent drainage for pancreaticojejunal anastomosis following pancreaticoduodenectomy. A total of 53 patients undergoing pancreaticoduodenectomy for various benign and malignant pathologies were included in the study. An external stent was inserted across the anastomosis to drain the pancreatic duct in 26 patients and 27 patients received no stent. The primary end point was pancreatic fistula. All surgeries were done by a single surgeon with expertise in hepatobiliary pancreatic surgery at a single institute. The two groups were comparable in demographic data, underlying pathologies, presenting complaints, presence of comorbid illnesses and proportion of patients with preoperative biliary drainage, pancreatic consistency and duct diameter. The pancreatic fistula rates were similar in both the groups (11.5 vs. 14.8?%, P?=?0.725). The morbidity and surgical re-exploration rate were statistically not significant between the two groups (65.4 vs. 51.9?%, P?=?0.318 and 11.5 vs. 7.4?%, P?=?0.60). Postoperative stay was also similar with a mean of 14?days in both the groups (P?=?0.66). The mortality rate was statistically not significant in the two groups (3.8 vs. 7.4?%, P?=?0.575). External drainage of pancreaticojejunostomy anastomosis and the pancreatic duct with a stent does not decrease the rate of postoperative pancreatic fistula after pancreaticoduodenectomy. 相似文献
38.
Mohammed AlSheef Mastourah Alotaibi Abdul Rehman Z. Zaidi Areej Alshamrani Aroub Alhamidi Syed Ziauddin A. Zaidi Noor Alanazi Sarah Alhathlool Ohoud Alarfaj Mohammed AlHazzaa Ghaydaa Kullab Amany Alboghdadly Amani Abu-Shaheen 《Saudi medical journal》2020,41(10):1063
Objectives:To identify the epidemiologic profile of cerebral vein thrombosis (CVT) among fasting women using oral contraceptive pills (OCPs) during the holy month of Ramadan.Methods:This retrospective study was conducted on all patients diagnosed with CVT and using OCPs from records at a tertiary care hospital in Riyadh, Saudi Arabia during 2016-2017. The study participants were categorized into 2 groups (an intermittently fasting group during the holy month of Ramadan and a non-fasting group).Results:Out of 108 female patients with CVT, 36.1% were secondary to OCP, of whom 41% participants were fasting. The most affected site was the transverse sinus. Holocephalic headache was more common amongst fasting group (68.8%) compared to non-fasting group (30.4%) (p=0.025). Dehydration (p=0.003) amongst the fasting group and protein S deficiency (p=0.027) in the non-fasting group were identified as the 2 prominent risk factors. Unfractionated heparin was the most common anticoagulant therapies used during the initiation phase for non-fasting (36.4%) and fasting groups (50%).Conclusion:All women who are using OCP should undergo formal written risk assessments for factors of CVT. Our study suggests that the negative effects of OCPs use might outweigh its benefits; thus, it should be prescribed with caution, more so in fasting patients. 相似文献
39.
BACKGROUND: General and local anesthetics are used in various combinations during surgical procedures to repair damaged tissues and organs, which in almost all instances involve nervous system functions. Because synaptic transmission recovers rapidly from various inhalation anesthetics, it is generally assumed that their effects on nerve regeneration and synapse formation that precede injury or surgery may not be as detrimental as that of their local counterparts. However, a direct comparison of most commonly used inhalation (sevoflurane, isoflurane) and local anesthetics (lidocaine, bupivacaine), vis-a-vis their effects on synapse transmission, neurite regeneration, and synapse formation has not yet been performed. METHODS: In this study, using cell culture, electrophysiologic and imaging techniques on unequivocally identified presynaptic and postsynaptic neurons from the mollusc Lymnaea, the authors provided a comparative account of the effects of both general and local anesthetics on synaptic transmission, nerve regeneration, and synapse formation between cultured neurons. RESULTS: The data show that clinically used concentrations of both inhalation and local anesthetics affect synaptic transmission in a concentration-dependent and reversal manner. The authors provided the first direct evidence that long-term overnight treatment of cultured neurons with sevoflurane and isoflurane does not affect neurite regeneration, whereas both lidocaine and bupivacaine suppress neurite outgrowth completely. The soma-soma synapse model was then used to compare the effects of both types of agents on synapse formation. The authors found that local but not inhalation anesthetics drastically reduced the incidence of synapse formation. The local anesthetic-induced prevention of synapse formation most likely involved the failure of presynaptic machinery, which otherwise developed normally in the presence of both sevoflurane and isoflurane. CONCLUSION: This study thus provides the first comparative, albeit preclinical, account of the effects of both general and local anesthetics on synaptic transmission, nerve regeneration, and synapse formation and demonstrates that clinically used lidocaine and bupivacaine have drastic long-term effects on neurite regeneration and synapse formation as compared with sevoflurane and isoflurane. 相似文献
40.
Congenital macrodactyly is a rare congenital malformation characterised by progressive enlargement of all mesenchymal elements of a digit. The present study is an attempt to draw the attention towards the similarities and differences between macrodactyly of the hand and foot. Radiographical, operative findings and histopathological examination of five cases are included in the present study. Emphasis was given to know the possible basic lesion. Radiographic findings, which differentiate this entity from other forms of local gigantism, were also analysed. The most characteristic finding noted was excessive overgrowth of fibro-fatty tissue with unusually large fatty lobules, apparently fixed by a mesh of dense fibrous tissue. Hypertrophy and tortuosity of the digital nerve, a striking feature in macrodactyly of the hand, was notably absent in cases affecting the foot. None of the patients had any other associated congenital anomalies. Neither the patients nor any of their family members had any stigmata of neurofibromatosis. Chromosomal study was normal in all of them. We conclude that in macrodactyly of the foot, excessive proliferation and accumulation of adipose tissue was the basic lesion, whereas involvement of the nerve might be the fundamental lesion in gigantism of the hand. Furthermore, whatever be the basic lesion, the final pathway must be either the local deficiency of a growth inhibiting factor or local expression of a basic intrinsic factor, leading to excessive growth of all elements of the digit. 相似文献