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   999篇
  免费   35篇
  国内免费   68篇
耳鼻咽喉   6篇
儿科学   27篇
妇产科学   24篇
基础医学   69篇
口腔科学   6篇
临床医学   93篇
内科学   188篇
皮肤病学   3篇
神经病学   13篇
特种医学   68篇
外科学   227篇
综合类   22篇
预防医学   18篇
眼科学   1篇
药学   67篇
肿瘤学   270篇
  2021年   6篇
  2020年   7篇
  2019年   10篇
  2018年   12篇
  2017年   5篇
  2015年   9篇
  2014年   12篇
  2013年   22篇
  2012年   15篇
  2011年   22篇
  2010年   15篇
  2009年   18篇
  2008年   27篇
  2007年   75篇
  2006年   21篇
  2005年   41篇
  2004年   26篇
  2003年   41篇
  2002年   37篇
  2001年   23篇
  2000年   36篇
  1999年   30篇
  1998年   27篇
  1997年   22篇
  1996年   28篇
  1995年   25篇
  1994年   14篇
  1993年   17篇
  1992年   31篇
  1991年   26篇
  1990年   29篇
  1989年   36篇
  1988年   34篇
  1987年   28篇
  1986年   41篇
  1985年   28篇
  1984年   22篇
  1983年   9篇
  1982年   12篇
  1980年   16篇
  1979年   16篇
  1978年   22篇
  1977年   22篇
  1976年   12篇
  1975年   6篇
  1974年   6篇
  1972年   7篇
  1971年   6篇
  1970年   6篇
  1966年   7篇
排序方式: 共有1102条查询结果,搜索用时 15 毫秒
1.
After ingesting or inhaling laundry detergent powder, eight children required hospital admission. The predominant symptoms were stridor, drooling, and respiratory distress. All but one patient underwent endoscopy of the airways and the esophagus, five children were admitted to the intensive care unit, and four children required endotracheal intubation. Laundry detergent ingestions are generally considered to have minor consequences, and there exists a paucity of literature on the subject. Evidence of significant morbidity incurred because of ingestion or inhalation of sodium carbonate-containing laundry detergent powder is presented, together with a review of the existing literature.  相似文献   
2.
3.
Studies have shown that systemic PTH treatment enhanced the rate of bone repair in rodent models. However, the mechanisms through which PTH affects bone repair have not been elucidated. In these studies we show that PTH primarily enhanced the earliest stages of endochondral bone repair by increasing chondrocyte recruitment and rate of differentiation. In coordination with these cellular events, we observed an increased level of canonical Wnt-signaling in PTH-treated bones at multiple time-points across the time-course of fracture repair, supporting the conclusion that PTH responses are at least in part mediated through Wnt signaling. INTRODUCTION: Since FDA approval of PTH [PTH(1-34); Forteo] as a treatment for osteoporosis, there has been interest in its use in other musculoskeletal conditions. Fracture repair is one area in which PTH may have a significant clinical impact. Multiple animal studies have shown that systemic PTH treatment of healing fractures increased both callus volume and return of mechanical competence in models of fracture healing. Whereas the potential for PTH has been established, the mechanism(s) by which PTH produces these effects remain elusive. MATERIALS AND METHODS: Closed femoral fractures were generated in 8-wk-old male C57Bl/6 mice followed by daily systemic injections of either saline (control) or 30 microg/kg PTH(1-34) for 14 days after fracture. Bones were harvested at days 2, 3, 5, 7, 10, 14, 21, and 28 after fracture and analyzed at the tissue level by radiography and histomorphometry and at the molecular and biochemical levels level by RNase protection assay (RPA), real-time PCR, and Western blot analysis. RESULTS: Quantitative muCT analysis showed that PTH treatment induced a larger callus cross-sectional area, length, and total volume compared with controls. Molecular analysis of the expression of extracellular matrix genes associated with chondrogenesis and osteogenesis showed that PTH treated fractures displayed a 3-fold greater increase in chondrogenesis relative to osteogenesis over the course of the repair process. In addition, chondrocyte hypertrophy occurred earlier in the PTH-treated callus tissues. Analysis of the expression of potential mediators of PTH actions showed that PTH treatment significantly induced the expression of Wnts 4, 5a, 5b, and 10b and increased levels of unphosphorylated, nuclear localized beta-catenin protein, a central feature of canonical Wnt signaling. CONCLUSIONS: These results showed that the PTH-mediated enhancement of fracture repair is primarily associated with an amplification of chondrocyte recruitment and maturation in the early fracture callus. Associated with these cellular effects, we observed an increase in canonical Wnt signaling supporting the conclusion that PTH effects on bone repair are mediated at least in part through the activation of Wnt-signaling pathways.  相似文献   
4.
Prolonged antipseudomonal parenteral antibiotic therapy combined with daily aural toilet has been effective in resolving long standing ear discharge in children with chronic suppurative otitis media. However, such treatment suffered from the disadvantages of prolonged hospitalization. We conducted a prospective study to investigate the feasibility and efficacy of exclusive outpatient treatment of children with chronic suppurative otitis media without cholesteatoma who had failed ototopical/oral antimicrobial therapy. The treatment consisted of daily aural toilet (suction and debridement) and twice daily parenteral ceftazidime (50 mg/kg/dose). Thirty-seven children were included. The duration of discharge from the ear before treatment was 6 to 121 months (median, 30 months). Aerobic cultures yielded Pseudomonas aeruginosa in 97%, often with other organisms. The management and follow-up were performed jointly by otolaryngology and infectious diseases physicians using the hospital ambulatory services. The route of ceftazidime administration (intravenous or intramuscular) was chosen according to the parents' and patients' convenience. Discharge stopped within 3 to 20 days (median, 8 days) in all children but one. Seventy-six percent of the 29 children available for follow-up 12 months after treatment were still free of discharge. Our results demonstrate that a regiment combining daily aural toilet and twice daily parenteral ceftazidime is highly efficacious in resolving ear discharge in children with chronic suppurative otitis media without cholesteatoma and that such a regimen does not require hospitalization.  相似文献   
5.
G W Sledge  L Einhorn  C Nagy  K House 《Cancer》1992,70(10):2524-2528
BACKGROUND. Ondansetron hydrochloride is a selective serotonin subtype 3 (5HT3) receptor antagonist that has been shown to be an effective antiemetic in patients receiving cisplatin chemotherapy. METHODS. This double-blind study compared the safety and efficacy of intravenous ondansetron with metoclopramide in patients receiving a 4- or 5-day regimen of cisplatin (20-40 mg/m2/day) combination chemotherapy. Forty-five patients were enrolled, and efficacy of the drug therapy could be studied for all 45. Patients were randomly assigned (1:1) to receive three daily intravenous doses of either 0.15 mg/kg ondansetron or 1 mg/kg metoclopramide. All patients were monitored daily for the number of emetic episodes (vomiting or retching), severity of nausea, adverse events, and laboratory safety parameters. RESULTS. Seven (30%) patients who received ondansetron had no emetic episodes throughout the entire study period compared with two (9%) who received metoclopramide (P = 0.077). The greatest difference in antiemetic efficacy was seen on day 1, when 18 (78%) patients who received ondansetron had no emetic episodes compared with 3 (14%) patients who received metoclopramide (P < 0.001). Significantly fewer antiemetic treatment failures (more than five emetic episodes or withdrawal from the study) occurred with patients given ondansetron (9%) than with those given metoclopramide (50%) during the entire study period (P = 0.002). The most commonly reported adverse event associated with ondansetron therapy was headache (controlled with acetaminophen), whereas diarrhea and restlessness were the most commonly reported adverse events associated with metoclopramide therapy. Extrapyramidal symptoms were judged to have occurred in 13 patients who received metoclopramide and 1 patient who received ondansetron. However, the patient who received ondansetron subsequently was judged to have had an anxiety attack. In patients with low or normal baseline transaminase values, a greater percentage who received ondansetron had transient increases as great as twice the upper limit of normal in aspartate transaminase (5% versus 0%) and alanine transaminase (17% versus 6%) than those who received metoclopramide. CONCLUSIONS. Ondansetron is superior to metoclopramide as antiemetic therapy for multiple-day cisplatin-based chemotherapy.  相似文献   
6.
We report seven patients with germ cell tumors which either recurred following a minimum of two regimens of platinum-based chemotherapy or were refractory to cisplatin. The patients were treated with one or two courses of high dose carboplatin (CBDCA) and etoposide (VP-16) plus ifosfamide (IFX) with mesna uroprotection and autologous bone marrow support. The doses given were CBDCA 500 mg/m2 every other day x 3 and VP-16 400 mg/m2 every other day x 3. IFX was given in a dose of 2 g/m2 daily x 5 days with mesna. The original intent of the protocol was to explore escalating doses of IFX, but excessive renal toxicity at the first dose level prevented escalation. Of the seven patients treated, four developed a marked decline in their renal function and three of the four required hemodialysis or hemofiltration. Six of seven patients treated had a decline in their serum markers indicating a response to therapy, but all have relapsed. Our conclusion is that while the combination of CBDCA/VP-16/IFX with ABMT is active in this group of patients, it is associated with excessive renal toxicity which is probably due to underlying renal dysfunction secondary to extensive prior cisplatin-based chemotherapy.  相似文献   
7.
硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用   总被引:8,自引:1,他引:7  
研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。  相似文献   
8.
During the past several years, there has been a resurgence of interest in preoperative or postoperative chemotherapy in patients with Stage III lung cancer. The staging system for lung cancer has recently been modified, and at the present time Stage III disease is now subdivided into Stage III-A (potentially surgically resectable for cure) and Stage III-B (unresectable). This article will review five recently completed studies utilizing neoadjuvant therapy in various types of Stage III lung cancer. The thoracic surgeon is faced with the dilemma of reviewing this literature and trying to make a conclusion as to what is appropriate therapy for Stage III disease. Unquestionably, neoadjuvant therapy appears to increase the resectability rate in Stage III-A disease and can make some Stage III-B patients anatomically resectable. It is hoped that future well-designed phase III studies can be accomplished in Stages III-A and III-B disease so that we can determine whether neoadjuvant chemotherapy is or is not beneficial for these patients.  相似文献   
9.
Thiazolidinediones (glitazones) are the only compounds currently available that specifically target tissue insulin resistance. The two currently available drugs in this class, pioglitazone and rosiglitazone,are approved by the Food and Drug Administration for the treatment of type 2 diabetes mellitus only. The therapeutic potential of the glitazones for other consequences of insulin resistance has stirred considerable interest, especially with regard to their potential beneficial impact on atherosclerotic cardiovascular disease and diabetes prevention. They also have been considered in the management of polycystic ovarian syndrome, nonalcoholic fatty liver disease, and other consequences of insulin resistance. The nonglycemic potential of glitazones is a clinical area in rapid evolution, wherein most data are on the impact of the glitazones onsurrogate markers that are associated with diseases, not on disease outcomes. This article provides insight and guidance to clinicians on the diverse nonglycemic potential of glitazones until conclusive outcome data become available.  相似文献   
10.
Introduction : Hypertrophic scar is a devastating sequel to burns and other tangential skin injuries. It follows deep dermal injuries and does not occur after superficial injuries. Nitric oxide (NO) plays many important roles in wound healing from inflammation to scar remodeling. Studies have shown that expression of nitric oxide synthase and nitric oxide production are decreased in human hypertrophic scar. However little is known about NO involvement in the early stages of hypertrophic scarring, because of the lack of an animal model. It was recently reported that the female red Duroc pig (FRDP) makes thick scar, which is similar to human hypertrophic scar. We hypothesized that NO production in wounds on the female, red Duroc pig is similar to that of human hypertrophic scar and that NO involvement in deep wounds is different from that in superficial wounds. Methods : Superficial (0.015” to 0.030”) and deep (0.045” to 0.060”) wounds were created on the backs of four FRDPs. Biopsies were collected at weeks 1.5, 4, 8 and 21 post wounding including samples of uninjured skin. Nitric oxide levels were measured with the Griess reaction assay and normalized with tissue protein level. Results : Superficial wounds healed with an invisible scar whereas the deep wounds healed with scar resembling mild hypertrophic scar. The thickness of the scars from the deep wounds was significantly greater than uninjured skin and healed superficial wounds (p < 0.01). NO levels were increased at 1.5 weeks in deep wounds compared to superficial wounds and uninjured skin (p < 0.05). At 8 weeks, NO levels in deep wounds had returned to the level of uninjured tissue and superficial wounds. By 21 weeks, NO levels had decreased significantly when compared to superficial wounds (p < 0.01). There were no differences in NO levels between uninjured skin and superficial wounds at any time point (p > 0.05). Conclusions : NO production is similar in late, deep wounds on the female, red Duroc pig to that reported in the literature for human hypertrophic scar further validating this animal model. NO production is quite different after deep wounds as compared to superficial wounds in the FRDP. Early elevation in nitric oxide production might account for excessive inflammation in deep wounds that become thick scars in the FRDP. Nitric oxide regulators and effects at early stages of scar formation should be elucidated further and the FRDP appears to be a useful model.  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