全文获取类型
收费全文 | 6664篇 |
免费 | 351篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 393篇 |
妇产科学 | 78篇 |
基础医学 | 596篇 |
口腔科学 | 172篇 |
临床医学 | 446篇 |
内科学 | 1492篇 |
皮肤病学 | 63篇 |
神经病学 | 520篇 |
特种医学 | 181篇 |
外科学 | 1138篇 |
综合类 | 183篇 |
一般理论 | 5篇 |
预防医学 | 348篇 |
眼科学 | 292篇 |
药学 | 589篇 |
中国医学 | 30篇 |
肿瘤学 | 422篇 |
出版年
2023年 | 55篇 |
2022年 | 126篇 |
2021年 | 271篇 |
2020年 | 137篇 |
2019年 | 183篇 |
2018年 | 240篇 |
2017年 | 161篇 |
2016年 | 194篇 |
2015年 | 197篇 |
2014年 | 282篇 |
2013年 | 322篇 |
2012年 | 490篇 |
2011年 | 528篇 |
2010年 | 277篇 |
2009年 | 238篇 |
2008年 | 363篇 |
2007年 | 346篇 |
2006年 | 325篇 |
2005年 | 241篇 |
2004年 | 233篇 |
2003年 | 207篇 |
2002年 | 163篇 |
2001年 | 78篇 |
2000年 | 85篇 |
1999年 | 99篇 |
1998年 | 43篇 |
1997年 | 29篇 |
1996年 | 31篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 26篇 |
1992年 | 74篇 |
1991年 | 103篇 |
1990年 | 51篇 |
1989年 | 86篇 |
1988年 | 72篇 |
1987年 | 75篇 |
1986年 | 70篇 |
1985年 | 46篇 |
1984年 | 34篇 |
1983年 | 24篇 |
1979年 | 37篇 |
1977年 | 26篇 |
1975年 | 19篇 |
1974年 | 43篇 |
1973年 | 38篇 |
1972年 | 29篇 |
1971年 | 27篇 |
1969年 | 18篇 |
1966年 | 20篇 |
排序方式: 共有7046条查询结果,搜索用时 15 毫秒
1.
2.
Emile Gogineni Zaker Rana Michael Wotman Jessie Karten Adam Riegel Mihaela Marrero Luis Maduro Dev Kamdar Douglas Frank Doru Paul Nagashree Seetharamu Maged Ghaly 《Journal of Geriatric Oncology》2021,12(1):122-127
PurposeManagement of head and neck cancers (HNC) in older adults is a common but challenging clinical scenario. We assess the impact of Stereotactic Body Radiation Therapy (SBRT) on survival utilizing the Geriatric-8 (G8) questionnaire.Materials and methods171 HNC patients, deemed medically unfit for definitive treatment, were treated with SBRT ± systemic therapy. G8 questionnaires were collected at baseline, at 4–6 weeks, and at 2–3 months post-treatment. Patients were stratified according to their baseline G8 score: <11 as ‘vulnerable’, 11–14 as ‘intermediate’, and >14 as ‘fit’. Overall survival (OS) was assessed through univariate Kaplan Meier analysis. Repeated measures ANOVA was used to determine if baseline characteristics affected G8 score changes.ResultsMedian follow-up was seventeen months. 60% of patients presented with recurrent HNC, 30% with untreated HNC primaries, and 10% with metastatic non-HNC primaries. Median age was 75 years. Median Charlson Comorbidity Index score was 2. 51% of patients were ‘vulnerable’, 37% were ‘intermediate’, and 12% were ‘fit' at baseline, with median survival of 13.2, 24.3, and 41.0 months, respectively (p = .004). Patients who saw a decrease in their follow-up G8 score (n = 69) had significantly lower survival than patients who had stable or increased follow-up G8 scores (n = 102), with median survival of 8.6 vs 36.0 months (p < .001).ConclusionThe G8 questionnaire may be a useful tool in upfront treatment decision-making to predict prognosis and prevent older patients from receiving inappropriate anti-cancer treatment. Decline in follow-up G8 scores may also predict worse survival and aid in goals of care following treatment. 相似文献
3.
4.
Ashish Chawla 《Singapore medical journal》2015,56(11):604-611
Cardiovascular and noncardiovascular conditions are commonly encountered in the emergency department. While the majority of patients have underlying cardiovascular aetiologies, such as acute myocardial infarction, congestive heart failure, aortic dissection and pulmonary embolism, a small subset of patients have underlying noncardiovascular conditions, although they present with similar symptoms of chest pain, dyspnoea, cough, haemoptysis and haematemesis. This article aims to describe the imaging findings in common noncardiovascular conditions of the chest that are frequently encountered in the emergency department, with a review of the existing literature. 相似文献
5.
6.
In contrast with cross-sectional designs used in previous studies, this exploratory study compared survey data from 127 matched pairs of clinical pharmacists and physicians working together. Physicians' perceptions of the importance of clinical pharmacy activities for patient care and the competence of pharmacists performing the activities were examined for their influence on prescribing behavior in an institutional setting. Data from a national survey showed that physicians rated pharmacists higher regarding recommendations based on drug use evaluations (p = 0.004) and competency to provide all clinical pharmacy services. Scores for pharmacokinetics ratings were similar between pharmacists and physicians (p = 0.168). Pharmacists rated the importance of recommendations based on cost-effectiveness higher than physicians (p = 0.012). Overall, physicians' perceptions of activity importance for patient care and pharmacist competency appear to dictate pharmacists' influence on physician prescribing behavior (R = 0.723). 相似文献
7.
Background
Traumatic perforation of the distal oesophagus due to blunt trauma is a very rare condition and is still associated with a significant morbidity and mortality. This is further exacerbated by delayed diagnosis and management as symptoms and signs are often masked by or ascribed to more common blunt thoracic injuries. 相似文献8.
Y K Murali P Anand V Tandon R Singh R Chandra P S Murthy 《Experimental and clinical endocrinology & diabetes》2007,115(10):641-646
The aqueous extract of the fruits of Terminalia chebula Retz. has been evaluated for its antidiabetic activity in streptozotocin (STZ) induced mild diabetic rats and compared with a known drug, tolbutamide. The oral effective dose (ED) of the extract was observed to be 200 mg/kg body weight, which produced a fall of 55.6% (p<0.01) in the oral glucose tolerance test. Oral administration of ED of aqueous extract of T.chebula (AETC) daily once for two months reduced the elevated blood glucose by 43.2% (p<0.01) and significantly reduced the increase in glycosylated hemoglobin (HbA1c) (p<0.01). The same dose also showed a marked improvement in controlling the elevated blood lipids as well as decreased serum insulin levels in contrast to the untreated diabetic animals. Hepatic and skeletal muscle glycogen content decreased by 75% and 62.9% respectively in diabetic controls, these alterations were partly prevented (34.9% and 21.17%) in AETC treated group when compared to the healthy controls. The in vitro studies with pancreatic islets showed that the insulin release was nearly two times more than that in untreated diabetic animals. The treatment did not have any unfavorable effect on other blood parameters of liver and kidney function tests. LD 50 was found to be above 3 g/kg bw i.e. 15 times of ED, because there were no deaths of animals even at this dose indicating high margin of safety. These findings suggest further investigations for the possible use of the aqueous extract of fruits of T.chebula for the treatment of diabetes. 相似文献
9.
Brain cyclooxygenases (COX), the rate-limiting enzyme in prostaglandin synthesis, is rapidly and transiently induced by convulsions in hippocampal and cortical neurons. Previous studies have explored the protective effect of naproxen (non-selective COX-inhibitor) or rofecoxib (selective COX-2 inhibitor) against chemical kindling in mice. With this background, the present study was designed to explore the possible effect of nimesulide (a preferential COX-2 inhibitor) against pentylenetetrazol (PTZ)-induced kindling epilepsy in mice. To induce kindling, PTZ was injected in a subconvulsive dose (40 mg/kg, i.p.) every other day for 15 days. Nimesulide (2.5 or 5 mg/kg, p.o.) was administered each day 45 min before either PTZ or vehicle challenge. The intensity of kindling was assessed immediately after PTZ administration according to a prevalidated scoring scale. On 16th day i.e. 24 h after the last dose of PTZ, animals were sacrificed and various biochemical parameters were assessed in the whole brain. Compared with normal control group, PTZ-kindled mice had significantly higher levels of malondialdehyde, nitrite, myeloperoxidase but had lower levels of reduced glutathione in the whole brain homogenate. Chronic treatment with nimesulide (2.5 or 5 mg/kg, p.o.) for 15 days showed significant decrease in kindling score and could play a role in controlling the accompanying biochemical alterations due to PTZ. These results suggested that nimesulide, a preferential COX-2 inhibitor offered neuroprotection against PTZ-induced kindling in mice. 相似文献
10.
Previous pharmacological studies with the pituitary gland have suggested that acetylcholine (ACh) might be involved in the regulation of intermediate lobe (IL) function. Whether ACh is endogenous to the IL cells or provided from an extrinsic source is unclear. The present experiments tested the possibility that the endocrine cells of the IL may be a source of ACh by measuring certain cholinergic markers in a primary culture of dissociated porcine cells. The endogenous ACh content was readily measurable in both the freshly dissociated IL cells and in 2- or 4-day primary cultures. Choline acetyltransferase activity was also measurable in the freshly dissociated and cultured IL cells and was reduced by 53% in the presence of a specific inhibitor, napthylvinylpyridine (50 μM). IL cells incubated in the presence of [14C]choline (1 μM) were able to synthesize [14C]ACh and the accumulation of the new ACh was inhibited by hemicholinium-3 (30 μM), a competitive inhibitor of high affinity choline uptake at cholinergic nerve terminals. In conclusion, these results demonstrate that the endocrine cells of the IL are capable of synthesizing and storing ACh. 相似文献