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   7169篇
  免费   401篇
  国内免费   29篇
耳鼻咽喉   54篇
儿科学   118篇
妇产科学   122篇
基础医学   914篇
口腔科学   158篇
临床医学   595篇
内科学   2181篇
皮肤病学   126篇
神经病学   619篇
特种医学   170篇
外科学   1018篇
综合类   64篇
一般理论   2篇
预防医学   539篇
眼科学   175篇
药学   436篇
中国医学   10篇
肿瘤学   298篇
  2023年   41篇
  2022年   100篇
  2021年   245篇
  2020年   113篇
  2019年   182篇
  2018年   259篇
  2017年   131篇
  2016年   203篇
  2015年   191篇
  2014年   285篇
  2013年   343篇
  2012年   545篇
  2011年   584篇
  2010年   345篇
  2009年   300篇
  2008年   464篇
  2007年   517篇
  2006年   482篇
  2005年   420篇
  2004年   413篇
  2003年   349篇
  2002年   334篇
  2001年   51篇
  2000年   52篇
  1999年   55篇
  1998年   65篇
  1997年   46篇
  1996年   36篇
  1995年   32篇
  1994年   30篇
  1993年   40篇
  1992年   35篇
  1991年   24篇
  1990年   16篇
  1989年   16篇
  1988年   17篇
  1987年   12篇
  1986年   14篇
  1985年   10篇
  1984年   23篇
  1983年   22篇
  1982年   19篇
  1981年   24篇
  1980年   13篇
  1979年   7篇
  1978年   7篇
  1977年   16篇
  1976年   9篇
  1974年   12篇
  1969年   6篇
排序方式: 共有7599条查询结果,搜索用时 15 毫秒
51.
AIM OF THE STUDY: To describe a technique of percutaneous CT guided catheter drainage of infected pancreatic necrosis and to report the results of this technique compared with those of the conventional surgical treatment and of other percutaneous drainage series. PATIENTS AND METHODS: Between 1992 and 1997, the series included 32 patients who had a severe acute necrotizing pancreatitis with a mean Ranson score of 4.6, scored into grade D (n = 10), and grade E (n = 22), according to the Balthazar radiological staging. Modified Van Sonnenberg 24 F double lumen catheters were used for continuous irrigation and aspiration. RESULTS: Forty-nine drains were inserted for 41 infected necroses and eight abscesses. Among the 32 patients, the proof of infected necrosis was obtained in 26 patients by fine needle aspiration and culture (enterococcus, staphylococcus, pseudomonas). The average delay of catheter insertion was 23 days after onset of pancreatitis; the mean duration of drainage was 43 days, and an average of three catheters per patient was required. Five patients (15%) died, and among the survivors, 16 (59%) presented 21 complications including 14 enterocutaneous or pancreatic fistulas. A subsequent surgical procedure including two necrosectomies was necessary in six patients. CONCLUSION: This study demonstrates that percutaneous drainage of infected pancreatic necrosis with a 15% mortality and 70% success rate, represents an interesting alternative to conventional surgery.  相似文献   
52.
Surgical resection is currently the only potentially curative treatment for gastric cancer. Nodal extension, present in 3/4 of the patients, is related to topography and penetration of the tumor and is progressive, beginning by the perigastric proximal lymph nodes N1 to the perivascular distal nodes N2. A subtotal gastrectomy is possible for distal cancers and total gastrectomy is necessary for cancers of the middle and upper portions. D1 lymphadenectomy is the resection of the N1 perigastric nodes (> 15) and D2 lymphadenectomy is the resection fo the N2 perivascular nodes (> 25). In Japan, 5 year survival after D2 resection is very high, around 60%, but all the series are retrospective with a high proportion of superficial cancers. In several recent European controlled studies, D2 resection is responsible for a high mortality rate (> 10%) and the reported 45% survival is not statistically different from the D1 resection. In Western patients an "in-between" lymphadenectomy without spleno-pancreatectomy can be recommended with analysis of at least 15 nodes, and with a mortality lower than 5%. Pathological analysis of the operative specimen allows to use the new TNM classification where the number of positive lymph nodes is the main independent prognostic factor.  相似文献   
53.
A four-year-old girl suffered difficult-to-diagnose hyponatremia resistant to treatment following surgery for a suprasellar tumor. The final diagnosis was diabetes insipidus evolving in three stages. Hyponatremia is a common problem following surgery to remove brain tumors. Early diagnosis and treatment of this electrolytic imbalance are essential for preventing serious neurological symptoms or death. The conditions most closely related to hyponatremia are inappropriate antidiuretic hormone secretion syndrome (IADHSS) and cerebral salt wasting syndrome (CSWS). The latter has become more common in recent years among patients undergoing brain surgery. Whereas IADHSS is treated by restricting fluids, CSWS requires administration of salt and volume fluid volume. We believe that for differential diagnosis of postoperative hyponatremia, a fluid restriction test takes priority over of fluid loading following neurosurgery. The course of hyponatremia must be carefully monitored and a complete endocrinological workup must be performed to detect the possible presence of hypophyseal deficiencies, particularly hypothyroidism and suprarenal insufficiency.  相似文献   
54.
The purpose of this study is to present the authors' long-term experience with total corporal contouring with megaliposuction. The evolution of body reshaping in one operative setting including simultaneous head and neck contouring, upper and lower extremity recontouring, and creation of an aesthetic trunk and abdominal form is discussed. Patient evaluation, operative techniques, postoperative management, and long-term results are emphasized. From February 1994 to February 1997, 120 consecutive patients underwent total corporal contouring with tumescent (Hunstad formula)-technique, classic liposuction. There were 10 males and 110 females. The average age of all patients was 28 years. Preoperative evaluation emphasized corporal shape and proportions. No other open procedures were performed simultaneously in these patients. The authors' postoperative regimen is discussed. The average amount of aspirated material in these series was 14,000 ml (range, 8000–20,000 ml). No blood transfusions were required. Complications included only hypopigmentation (N= 2) and postoperative seromas requiring aspiration (N= 12). Follow-up examination took place at 3 months to 3 years, with an average of 14 months. All patients underwent a metamorphosis from an amorphic shape to one that follows the normal body contours and profiles. The goals of megaliposuction are no longer just to reduce body fat and body mass. Individually planned surgery for these patients should be based upon obtaining normal symmetrical body proportions. Total corporal contouring and reshaping can now be safely performed, offering hope and predictable outcomes to this patient population. Patient evaluation, operative technique, postoperative care, and long-term results are presented.  相似文献   
55.
There is currently interest in the potential use of selective inhibitors of cyclic nucleotide phosphodiesterases (PDE) in the treatment of asthma. In this study we examined the effects of three selective PDE inhibitors, milrinone (PDE III), rolipram (PDE IV) and zaprinast (PDE V), on the broncoconstriction produced by antigen and histamine, the airway hyperreactivity and microvascular leakage after aerosol exposure to platelet-activating factor (PAF) and antigen, and the antigen-induced eosinophil infiltration in guinea-pig lung. Inhaled rolipram (0.01–10 mg ml–1) inhibited dose dependently the bronchospasm produced by aerosol antigen (5 mg ml–1) an anaesthetised, ventilated guinea-pigs. Rolipram (10 mg ml–1) produced maximal inhibition of antigen-induced bronchoconstriction but only partial inhibition of the response to aerosol histamine (1 mg ml–1). Milrinone and zaprinast (each 10 mg ml–1) showed weak, or no, inhibitory effects against bronchoconstriction produced by aerosol antigen or histamine. Pretreatment with rolipram (10 mg kg–1, i.p.) prevented airway hyperreactivity to histamine which develops 24 h after exposure of conscious guinea-pigs to aerosol PAF (500 g ml–1) or antigen (5 mg ml–1). The pulmonary eosinophil infiltration obtained with 24 h of antigen-exposure was inhibited by rolipram. In contrast, milrinone and zaprinast (each 10 mg kg–1, i.p.) failed to reduce either the airway hyperreactivity of the eosinophil accumulation in these animals. Rolipram (1–10 mg ml–1) reduced the extravasation of Evans blue after aerosol PAF (500 g ml–1) at all airway levels while a lower dose (0.1 mg ml–1) was only effective at intrapulmonary airways. Rolipram (0.01–1 mg ml–1) markedly reduced airway extravasation produced by inhaled antigen (5 mg ml–1). Zaprinast (1–10 mg ml–1) was also effective against airway microvascular leakage produced by aerosol PAF or antigen while milrinone (10 mg ml–1) had no antiexudative effect. These data support previous suggestions that pharmacological inhibition of PDE IV results in anti-spasmogenic and anti-inflammatory effects in the airways and may be useful in the treatment of asthma.  相似文献   
56.
Overwhelming post splenectomy infections in childhood were first described by King and Shumaker in 1952. This septic risk, although a matter of controversy, also exists in adults. Thus, splenic conservation must become a surgical concern in left pancreas resections for benign or traumatic diseases. The authors report their experience with a simplified procedure in which the splenic pedicle is resected "en bloc" with the left pancreas. This technique has been employed in thirteen patients, in whom spleen could be preserved in twelve, without operative mortality and a low morbidity rate.  相似文献   
57.
A clinicopathologic case is presented. The patient was a 12-year-old white girl with a history of fatigue and dizziness, occasional nausea and vomiting, and anemia, who showed abdominal distention, especially in the epigastrium. An epigastric mass was palpable. Gastroscopy was done, and surgery followed. Pertinent laboratory findings are presented, and clinical discussion follows. The pathology is then presented and discussed.  相似文献   
58.
A case of isolated dissection of the superior mesenteric artery is presented here. This rare condition was confirmed angiographically in a 46-year-old man with persistent abdominal pain. He was treated initially with anticoagulation alone. One year later, he developed recurrent symptoms and had radiologic documentation of progression of the condition. Operative repair was performed and recovery was uneventful. This case demonstrates a failure of the nonoperative approach to this rare condition and suggests that disease progression may be inevitable. Early surgical correction may ease operative management.  相似文献   
59.
In many cities, infectious disease and overdose epidemics are occurring among illicit injection drug users (IDUs). To reduce these concerns, Vancouver opened a supervised safer injecting facility in September 2003. Within the facility, people inject pre-obtained illicit drugs under the supervision of medical staff. The program was granted a legal exemption by the Canadian government on the condition that a 3-year scientific evaluation of its impacts be conducted. In this review, we summarize the findings from evaluations in those 3 years, including characteristics of IDUs at the facility, public injection drug use and publicly discarded syringes, HIV risk behaviour, use of addiction treatment services and other community resources, and drug-related crime rates. Vancouver's safer injecting facility has been associated with an array of community and public health benefits without evidence of adverse impacts. These findings should be useful to other cities considering supervised injecting facilities and to governments considering regulating their use.  相似文献   
60.
It has been reported that benzylamine reduces blood glucose in rabbits, stimulates hexose uptake, and inhibits lipolysis in mouse, rabbit, and human adipocytes. In the presence of vanadate, benzylamine is also able to improve glucose disposal in normoglycaemic and diabetic rats. Such insulin-mimicking properties are the consequence of hydrogen peroxide production during benzylamine oxidation by semicarbazide-sensitive amine oxidase (SSAO). The aim of the study was to determine whether other SSAO-substrates could share such potential antidiabetic properties. Thus, mafenide, a synthetic antimicrobial sulfonamide structurally related to benzylamine, and which has been recently reported to interact with SSAO, was tested in the above mentioned models, in parallel with methylamine, a proposed endogenous SSAO-substrate. All tested amines stimulated glucose uptake and inhibited lipolysis in rat and mouse fat cells. Methylamine and benzylamine, but not mafenide, reduced the hyperglycaemic response during a glucose tolerance test in rabbits while the three amines tested were devoid of insulin-releasing activity under both in vivo and in vitro conditions. In human adipocytes, mafenide did not stimulate glucose transport since it was not a high-affinity substrate for SSAO and generated less hydrogen peroxide than benzylamine or methylamine. Therefore, mafenide could not be considered as an antidiabetic drug despite being oxidized and exhibiting insulin-mimicking effects in rat and mouse adipocytes. By contrast, the endogenous substrate methylamine improved glucose utilization in all in vitro and in vivo models, leading to consider novel SSAO substrates as drugs with potential anti-hyperglycaemic properties.  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