首页 | 官方网站   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   19323篇
  免费   1489篇
  国内免费   73篇
医药卫生   20885篇
  2024年   41篇
  2023年   279篇
  2022年   504篇
  2021年   962篇
  2020年   586篇
  2019年   763篇
  2018年   824篇
  2017年   622篇
  2016年   705篇
  2015年   717篇
  2014年   879篇
  2013年   1132篇
  2012年   1643篇
  2011年   1677篇
  2010年   845篇
  2009年   742篇
  2008年   1149篇
  2007年   1162篇
  2006年   992篇
  2005年   962篇
  2004年   878篇
  2003年   783篇
  2002年   673篇
  2001年   108篇
  2000年   82篇
  1999年   104篇
  1998年   128篇
  1997年   110篇
  1996年   76篇
  1995年   80篇
  1994年   65篇
  1993年   48篇
  1992年   44篇
  1991年   51篇
  1990年   47篇
  1989年   26篇
  1988年   24篇
  1987年   28篇
  1986年   20篇
  1985年   31篇
  1984年   30篇
  1983年   26篇
  1982年   20篇
  1981年   30篇
  1980年   21篇
  1979年   11篇
  1978年   24篇
  1977年   11篇
  1976年   11篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.

Introduction

Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.

Innovation

An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.

Outcomes

A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.

Comments

We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes.  相似文献   
2.
3.
OBJECTIVE: To prospectively determine the sonographic findings of nodular hyperplasia of the thyroid, to compare these with reported findings associated with malignancy, and to assess interobserver reliability. METHODS: Seventy thyroid nodules were scanned, and then biopsies of the nodules were performed under sonographic guidance with fine-needle cytologic analysis; in all cases images were reviewed by 2 experienced radiologists without knowledge of clinical outcome. Findings reported associated with malignancy were specifically assessed. Interobserver agreement between the expert and secondary readers for each finding was calculated by the kappa or weighted kappa statistic and the Fisher exact test of independence. RESULTS: There were 68 benign and 2 malignant nodules in a population of 63 female and 7 male patients. The mean benign nodule size was 2.9 cm; 60% were solid; 54% were hypoechoic; 59% were microlobulated or macrolobulated; 47% had central vascularity; 24% contained calcifications; and 82% were elliptical in shape. There was very good interobserver reliability for the presence of calcium (kappa = 0.91) and good agreement for the presence and location of vascularity (kappa = 0.75) and the amount of cystic components (kappa = 0.62; all P < .01). CONCLUSIONS: Sixty-nine percent of benign nodules had at least 1 finding reported previously as associated with malignancy. The interobserver reliability of the sonographic findings was good to very good for 3 of the 5 findings assessed.  相似文献   
4.
The relationship of haemolytic disease of the newborn (HDN) to the transplacental passage of the four IgG subclasses was assessed at varous gestational ages by comparing the maternal and fetal IgG subclass concentrations in 34 pregnancies at risk of HDN with those in 30 pregnancies not at risk. Higher maternal and fetal IgG1 levels were attained in pregnancies at risk of HDN than in pregnancies not at risk. In contrast, a slight decrease in maternal IgG2 and IgG4 levels occurred in pregnancies at risk of HDN, as compared with a slight rise in maternal IgG2 and IgG4 levels in pregnancies not at risk of HDN. Changes in fetal IgG2 and 4 concentrations in either type of pregnancy were very similar, showing only slight increases between the 19th and 34th week of gestation. A slight decrease in maternal IgG3 occurred in both types of pregnancy. In contrast, higher and fairly steady levels of fetal IgG3 were observed in fetuses not at risk of HDN throughout gestation, when compared with those in 'at risk' pregnancies. However, the statistical reliability of these results is not clear since only small numbers of samples were tested and because wide variations in IgG concentrations were observed. The IgG subclass concentrations in 50 paired maternal and cord blood samples were also measured and revealed that IgG1 levels were substantially higher in cord rather than maternal blood; cord and maternal IgG2, 3 and 4 levels, on the other hand, were fairly similar.  相似文献   
5.
Cisplatin in combination with other cytotoxic agents is the backbone for a potential cure of testicular germ cell neoplasms and is a critical factor in the substantial activity observed in the treatment of small cell lung cancer, bladder cancer, and ovarian germ cell tumors. Resistance to cisplatin at the onset of treatment or at relapse limits its curative potential, however. Laboratory studies using both cells selected for cisplatin resistance by exposure to sublethal concentrations and biopsy specimens from patients' tumors provide insights for the potential mechanisms of resistance. The mechanisms identified in vitro include a complex and wide array of related and unrelated pathways such as alterations in cellular drug transport, enhanced DNA repair dependent and independent of signal transduction pathways, and enhanced intracellular detoxification such as glutathione and metallothionein systems. Studies of these mechanisms have identified a number of agents with known potential for administration to humans and that reverse cisplatin resistance in vitro; for example, reversal of cellular accumulation defects by dipyridamole; inhibition of DNA repair by hydroxyurea, pentoxifylline, and novobiocin; inhibition of the glutathione system by ethacrynic acid and buthionine sulfoximine; and inhibition of signal transduction pathways by cyclosporine, tamoxifen, and calcium channel-blocking agents. Current phase I clinical trials are focusing on the most effective doses and schedules to administer these agents in combination with cisplatin. Initial uncontrolled trials in limited numbers of patients suggest that the addition of modulators of cisplatin has the potential to reverse resistance in patients previously failing therapy. Another promising avenue for circumventing cisplatin resistance is the development of noncross-resistant platinum analogs.  相似文献   
6.
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182  相似文献   
7.
We explored the relationship between striatal dopamine-2 (D(2)) receptor occupancy and extra-pyramidal symptoms (EPS) in bipolar patients receiving olanzapine. Seventeen patients with a DSM-IV diagnosis of bipolar disorder were treated with 5-45 mg/day olanzapine for at least 14 days. After that period, D(2) receptor occupancy was determined using Iodobenzamide (IBZM) and SPECT. EPS were assessed by the Simpson-Angus Scale (SAS) and Barnes-Akathisia Scale (BAS). We found a dose-dependent increase in occupancy: 5 mg led to 28-50%, 10 mg to 40-68%, 15 mg to 69%, 20 mg to 57-66%, 30 mg to 66% and 45 mg to 80% D(2) receptor occupancy; and a significant correlation between plasma levels and occupancy (R(2)=.55, P=.001). Similar to schizophrenic patients, bipolar patients did not exhibit EPS at D(2) occupancy levels of 28 to 80%. Although we did not find an increased vulnerability for acute EPS in bipolar patients receiving olanzapine at clinical relevant doses, this needs to be replicated with larger sample sizes.  相似文献   
8.
Obsessive Compulsive Disorder (OCD) affects 0.5–2% of young people many of whom are resistant to conventional treatments. This case study describes an 18-year-old male with OCD who first underwent cognitive behavioral therapy (CBT) for a 1-year period with a modest response (his OCD had shifted from severe to moderate). Within a year, his anxiety had deteriorated back to the severe range and he now had major depression. He then entered an ABAB design trial using a nutritional formula consisting mainly of minerals and vitamins (together, known as micronutrients). After 8 weeks on the formula, his mood was stabilized, his anxiety reduced, and his obsessions were in remission. The treatment was then discontinued for 8 weeks, during which time his obsessions and anxiety worsened and his mood dropped. Reintroduction of the formula again improved the symptoms. This case illustrates the importance of considering the effect micronutrients have on mental illness.  相似文献   
9.
Balanced analgesia (an opioid and a nonsteroidal anti-inflammatory agent) after hysterectomy often leads to better postoperative pain outcomes. Researchers compared post-hysterectomy patients who received balanced analgesia with those who received only morphine patient-controlled analgesia, and their relationship with pain scores, ambulation, and hospital length of stay.  相似文献   
10.
Rats undergoing extinction of lever-pressing for food after the attenuation of an external feedback for this behavior exhibit excessive lever-pressing unaccompanied by an attempt to collect a reward. This behavior may be analogous to the excessive and unreasonable behavior seen in obsessive-compulsive disorder. In the present study, we tested the hypothesis that the compulsive behavior induced by signal attenuation is mediated via D(1) rather than D(2) receptors. Administration of 0.005, 0.01 and 0.03 mg/kg of the D(1) antagonist SCH 23390 reduced the number of compulsive lever-presses without affecting the number of lever-presses followed by an attempt to collect a reward. In contrast, administration of 0.005, 0.01, 0.024, 0.036 and 0.05 of the D(2) antagonist haloperidol dose-dependently decreased both types of lever-presses. In addition, haloperidol at doses that decreased lever-pressing in the post-training signal attenuation procedure (0.036 and 0.05 mg/kg) had a similar effect in regular extinction, whereas an SCH 23390 dose that decreased compulsive lever-pressing in the post-training signal attenuation procedure (0.01 mg/kg) had no effect on regular extinction. On the basis of electrophysiological data on the response of dopamine neurons to the omission of an expected reward, these results were interpreted as suggesting that compulsive lever-pressing depends on a phasic decrease in the stimulation of D(1) receptors. The implications of these results for the pathophysiology and treatment of obsessive-compulsive disorder are discussed.  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-23

京公网安备 11010802026262号