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   1581篇
  免费   65篇
  国内免费   5篇
耳鼻咽喉   83篇
儿科学   120篇
妇产科学   11篇
基础医学   168篇
口腔科学   32篇
临床医学   95篇
内科学   363篇
皮肤病学   31篇
神经病学   38篇
特种医学   28篇
外科学   228篇
综合类   15篇
预防医学   47篇
眼科学   128篇
药学   106篇
中国医学   6篇
肿瘤学   152篇
  2024年   5篇
  2023年   14篇
  2022年   43篇
  2021年   48篇
  2020年   28篇
  2019年   33篇
  2018年   30篇
  2017年   32篇
  2016年   46篇
  2015年   49篇
  2014年   70篇
  2013年   80篇
  2012年   106篇
  2011年   102篇
  2010年   78篇
  2009年   39篇
  2008年   94篇
  2007年   83篇
  2006年   97篇
  2005年   78篇
  2004年   98篇
  2003年   77篇
  2002年   81篇
  2001年   30篇
  2000年   37篇
  1999年   34篇
  1998年   20篇
  1997年   18篇
  1996年   7篇
  1995年   5篇
  1994年   10篇
  1993年   5篇
  1992年   14篇
  1991年   8篇
  1990年   5篇
  1989年   6篇
  1988年   9篇
  1986年   4篇
  1985年   2篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1979年   1篇
  1978年   9篇
  1977年   1篇
  1975年   3篇
  1974年   1篇
  1971年   1篇
  1970年   1篇
排序方式: 共有1651条查询结果,搜索用时 15 毫秒
71.
This study aimed to document the morphological and immunophenotypic features, and describe the diagnostic features of bone marrow (BM) involvement in human herpes virus 8 Multicentric Castleman disease (HHV8‐MCD). BM trephine biopsy (BMTB) specimens from 28 patients were revisited. Samples were evaluated for expression of CD3, CD20, CD138, CD68R, glycophorin C, CD42b, HHV8‐latency‐associated nuclear antigen (LANA1), Epstein–Barr virus‐encoded small RNA and light chains. Presence of significant numbers of HHV8‐LANA1+ lymphoid/plasmacytic cells, noted in 10/28 cases, was indicative of BM involvement and was associated with low CD4 and CD8 counts in peripheral blood. The characteristic morphological appearance of MCD seen in lymph nodes is a rare finding in BMTB. 4/5 cases with lymphoid aggregates were involved by MCD, whereas 6/23 cases without lymphoid aggregates were involved by MCD (= 0·023). 9/18 cases with hypercellular marrow were involved by MCD, whilst only 1/8 cases with normo/hypocellular marrow showed involvement by MCD (= 0·070). While 9/21 cases with increased marrow reticulin were involved by MCD, none of the cases with no increase in reticulin were involved by MCD (= 0·080). Reactive plasmacytosis is a frequent finding. We conclude that bone marrow is involved in a significant proportion of patients with MCD (36%), and involvement can be identified by HHV8‐LANA1 immunohistochemistry.  相似文献   
72.
AIM: To assess role of combined modality of mechanical fragmentation and intralesional thrombolysis in patients with massive pulmonary embolism presenting subacutely. METHODS: Eight of 70 patients presenting in tertiary care centre of North India with massive pulmonary embolism within 4 years had subacute presentation (symptom onset more than 2 wk). These patients were subjected to pulmonary angiography with intention to treat basis via mechanical breakdown and intra lesional thrombolysis. Mechanical breakdown of embolus was accomplished with 5-F multipurpose catheter to reestablish flow, followed by intralesional infusion of urokinase (4400 IU/kg over 10 min followed by 4400 IU/kg per hour over 24 h). RESULTS: Eight patients, mean age 47.77±12.20 years presented with subacute pulmonary embolism (mean duration of symptoms 2.4 wk). At presentation, mean heart rate, shock index, miller score and mean pulmonary pressures were 101.5±15.2/min, 0.995±0.156, 23.87±3.76 and 37.62±6.67 mmHg which reduced to 91.5±12.2/min (P=0.0325), 0.789±0.139 (P=0.0019), 5.87±1.73 (P=0.0000004) and 27.75±8.66 mmHg (P=0.0003) post procedurally. Mean BP improved from 80.00±3.09 mmHg to 90.58±9.13 mmHg (P=0.0100) post procedurally. Minor complications in the form of local hematoma-minor hematoma in 1 (12.5%), and pseudoaneurysm (due to femoral artery puncture) in 1 (12.5 %) patient were seen. At 30 d and 6 mo follow up survival rate was 100% and all the patients were asymptomatic and in New York Heart Association class 1. CONCLUSION: Combined modality of mechanical fragmentation and intralesional thrombolysis appears to be a promising alternative to high risk surgical procedures in patients with subacute massive pulmonary embolism.  相似文献   
73.
74.
Mucormycosis of the anterior abdominal wall is an uncommon disease and it is very rare to find this disease in immunocompetent, non-diabetic patients which usually affects patients with trauma, with contaminated wounds, patients with underlying malignancies or patients with immunocompromised state, e.g., diabetics. We herein report a case of primary cutaneous mucormycosis in an immunocompetent and non-diabetic patient. Our patient was a 48-year-old female, executive by profession. She was diagnosed to have cutaneous mucormycosis of the anterior abdominal wall, and was managed with multiple debridements of the wound and intravenous amphotericin B therapy. She was administered a total of 1500 mg of liposomal amphotericin B and when fully healed, split skin grafting was done. We would like to emphasize the importance of high index of suspicion and early start of therapy in a condition with high rate of mortality.  相似文献   
75.
Post-catheterization PSA is one of the most commonly encountered vascular complications of cardiac and peripheral angiographic procedures. We report the case of patient who developed deep-seated profunda femoris artery pseudoaneurysm (PSA) following cardiac catheterization. Despite, repeated ultrasound guided compressions the PSA failed to close and instead produced local site pressure ulcers. The secondary infection followed which precluded use of percutaneous thrombin injection. The PSA was finally closed via a total endovascular technique combining intravascular thrombin injection and coil embolization, thus obviating the need for expensive measures like cover stents or invasive surgical repairs.  相似文献   
76.
Rosai Dorfman disease or sinus histiocytosis is a rare, idiopathic, benign and self-limiting histiocytic proliferative disorder, usually seen in younger patients. It most commonly involves the cervical lymph nodes, with a predominant infiltration of sinusoidal histiocytes and classically presents with massive cervical lymhadenopathy. Extranodal disease occurs in about 43% of cases and produces different signs and symptoms depending upon its location. We report a case of this disorder in 22-year-old male with initial isolated involvement of bilateral nasal cavity and paranasal sinuses with subsequent involvement of cervical lymph nodes and skin. The clinical presentation, histologic characterstics, radiographic findings and treatment of the disease are discussed.  相似文献   
77.
Nasopharyngeal angiofibromas are notorious for silently extending to the regions adjoining their original sites. Their exact localization is essential for the total excision. Conventional X-rays have limited value in demonstrating extensions to base of skull, pterygopalatine fossa and paranasal sinuses. GAT Scanning when used along with contrast, provides clear delineation of every minute tumour extension, along with exact evidence of bone destruction. Angiography on the other hand is additionally useful in determining the vascular feeders, and differentiating from other regional tumefactions. Angiography may further clarify the vascularity and maturity of the tumours. The tumour blush in arterial phase suggests exact localisation of the lesion. Poor filling veins in venous phase indicate larger sinusoidal spaces. Mature or more fibrous tumours have better venous filling during this phase. These three modalities, therefore, appear to be complementary aids to the diagnosis and localisation of tumours and hence essential for planning the surgical procedure for total excision of these nasopharyngeal angiofibromas.  相似文献   
78.
79.
Off-pump multivessel coronary artery surgery in high-risk patients   总被引:11,自引:0,他引:11  
BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass. METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < or = 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups. RESULTS: The average number of grafts was 3.0 +/- 0.4 and 3.2 +/- 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 +/- 5 vs 24 +/- 6 hours, p < 0.001), mean blood loss (362 +/- 53 vs 580 +/- 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 +/- 8 hours) and hospital stay (6 +/- 3 days) were significantly less in the OPCAB group (p < 0.001). CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients.  相似文献   
80.
Positron emission tomography imaging in nonmalignant thoracic disorders   总被引:11,自引:0,他引:11  
The role of the fluorodeoxyglucose (FDG) technique positron emission tomography (PET) is well established in the management of patients with lung cancer. Increasingly, it is becoming evident that FDG-PET can be effectively employed to diagnose a variety of benign pulmonary disorders. Knowledge of such applications further expands the domain of this powerful modality and further improves the ability to differentiate benign from malignant diseases of the chest. We describe pertinent technical factors that substantially contribute to optimal imaging of the thoracic structures. Particularly, the complementary role of attenuation correction (AC) to that of non-AC images is emphasized. We further outline the need for and the state of the art for co-registration of PET and anatomic images for diagnostic and therapeutic purposes. We then review patterns of physiologic uptake of FDG in thoracic structures, including the lung, the heart, the aorta and large arteries, esophagus, thymus, trachea, thoracic muscles, bone marrow, and joints and alterations following radiation therapy to the thorax. A great deal of information is provided with regard to differentiating benign from malignant nodules and in particular, we emphasize the role of dual time point imaging and partial volume correction for accurate assessment of such lesions. Following a brief review of the diagnostic issues related to the assessment of mediastinal adenopathies, the role of FDG-PET imaging in environment-induced lung diseases, including pneumoconiosis, smoking, and asthma are described. A large body of information is provided about the role of this technology in the management of patients with suspected infection and inflammation of the lungs such as acquired immunodeficiency syndrome, fever of unknown origin, sarcoidosis, chronic granulomatous disease and monitoring the disease process and response to therapy. Finally, the value of FDG-PET in differentiating benign from malignant diseases of the pleura including asbestosis-related disorders is described at the conclusion of this comprehensive review.  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