全文获取类型
收费全文 | 18750篇 |
免费 | 1249篇 |
国内免费 | 241篇 |
专业分类
耳鼻咽喉 | 472篇 |
儿科学 | 335篇 |
妇产科学 | 278篇 |
基础医学 | 2808篇 |
口腔科学 | 440篇 |
临床医学 | 1409篇 |
内科学 | 3836篇 |
皮肤病学 | 682篇 |
神经病学 | 1344篇 |
特种医学 | 1382篇 |
外科学 | 2586篇 |
综合类 | 94篇 |
一般理论 | 4篇 |
预防医学 | 698篇 |
眼科学 | 356篇 |
药学 | 1564篇 |
中国医学 | 226篇 |
肿瘤学 | 1726篇 |
出版年
2024年 | 11篇 |
2023年 | 154篇 |
2022年 | 420篇 |
2021年 | 688篇 |
2020年 | 382篇 |
2019年 | 490篇 |
2018年 | 643篇 |
2017年 | 509篇 |
2016年 | 779篇 |
2015年 | 992篇 |
2014年 | 1116篇 |
2013年 | 1192篇 |
2012年 | 1792篇 |
2011年 | 1699篇 |
2010年 | 1016篇 |
2009年 | 798篇 |
2008年 | 1092篇 |
2007年 | 1039篇 |
2006年 | 943篇 |
2005年 | 885篇 |
2004年 | 760篇 |
2003年 | 597篇 |
2002年 | 540篇 |
2001年 | 243篇 |
2000年 | 220篇 |
1999年 | 209篇 |
1998年 | 78篇 |
1997年 | 58篇 |
1996年 | 65篇 |
1995年 | 37篇 |
1994年 | 39篇 |
1993年 | 39篇 |
1992年 | 68篇 |
1991年 | 90篇 |
1990年 | 54篇 |
1989年 | 57篇 |
1988年 | 52篇 |
1987年 | 54篇 |
1986年 | 42篇 |
1985年 | 40篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1982年 | 21篇 |
1981年 | 11篇 |
1979年 | 31篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1974年 | 14篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
The cingulum, connecting the orbitofrontal cortex to the medial temporal lobe, involves in diverse cognition functions including attention, memory, and motivation. To investigate the relationship between the cingulum injury and cognitive impairment in patients with chronic mild traumatic brain injury, we evaluated the integrity between the anterior cingulum and the basal forebrain using diffusion tensor tractography in 73 patients with chronic mild traumatic brain injury(39 males, 34 females, age 43.29 ± 11.42 years) and40 healthy controls(22 males, 18 females, age 40.11 ± 16.81 years). The patients were divided into three subgroups based on the integrity between the anterior cingulum and the basal forebrain on diffusion tensor tractography: subgroup A(n = 19 patients)-both sides of the anterior cingulum were intact; subgroup B(n= 36 patients)-either side of the anterior cingulum was intact; and subgroup C(18 patients)-both sides of the anterior cingulum were discontinued. There were significant differences in total Memory Assessment Scale score between subgroups A and B and between subgroups A and C. There were no significant differences in diffusion tensor tractography parameters(fractional anisotropy, apparent diffusion coefficient, and fiber volume) between patients and controls. These findings suggest that the integrity between the anterior cingulum and the basal forebrain, but not diffusion tensor tractography parameter, can be used to predict the cognitive function of patients with chronic mild traumatic brain injury. This study was approved by Yeungnam University Hospital Institutional Review Board(approval No. YUMC-2014-01-425-010) on August 16, 2017. 相似文献
2.
3.
The effect of zinc deficiency on intestinal absorption of cholesterol was investigated in adult male rats fed 3.6 ppm of dietary zinc (ZD) and compared with pair-fed (PF) and ad-libitum (CT) controls fed 30.6 ppm of zinc for 10 to 12 wk. The intestinal absorption of cholesterol was measured by collecting the mesenteric lymph at hourly intervals for 8 h after infusing a dose of [14C]cholesterol in a lipid emulsion through an indwelling duodenal catheter. Data on the hourly lymphatic output of [14C]cholesterol showed that the absorption of [14C]cholesterol plateaued at 4 h postdosing in all groups. The rate of the appearance of [14C]cholesterol in the mesenteric lymph significantly decreased in ZD rats at 5 h and thereafter. The cumulative absorption of [14C]cholesterol by ZD rats for the 8-h period was 4.4 +/- 1.0% of the dose, compared with 11.8 +/- 1.1% by PF and 10.7 +/- 1.4% by CT rats. There were no differences in percent distribution of esterified [14C]cholesterol among the three groups. Also, no significant change in mucosal cholesterol esterase activity was observed due to zinc deficiency. The present data and previous findings taken together suggest that the primary mechanism responsible for the impaired absorption of cholesterol may be associated with defective formation of chylomicrons in the intestinal mucosa. 相似文献
4.
N Diehm A Shang A Silvestro D-D Do F Dick J Schmidli F Mahler I Baumgartner 《European journal of vascular and endovascular surgery》2006,31(1):59-63
OBJECTIVES: Aim of this study is to correlate distribution pattern of lower limb atherosclerosis with cardiovascular risk factor profile of patients with peripheral arterial occlusive disease (PAD). PATIENTS AND METHODS: Analysis is based on a consecutive series of 2659 patients (1583 men, 1076 women, 70+/-11 years) with chronic PAD of atherosclerotic origin undergoing primary endovascular treatment of lower extremity arteries. Pattern of atherosclerosis was grouped into iliac (n=1166), femoropopliteal (n=2151) and infrageniculate (n=888) disease defined according to target lesions treated. A multivariable multinomial logistic regression analysis was performed to assess relation with age, gender and classical cardiovascular risk factors (diabetes mellitus, arterial hypertension, hypercholesterolemia, cigarette smoking) using femoropopliteal disease as reference. RESULTS: Iliac disease was associated with younger age (RRR 0.95 per year of age, 95%-CI 0.94-0.96, p<0.001), male gender (RRR 1.32, 95%-CI 1.09-1.59, p=0.004) and cigarette smoking (RRR 2.02, 95%-CI 1.68-2.42, p<0.001). Infrageniculate disease was associated with higher age (RRR 1.02, 95%-CI 1.01-1.02, p<0.001), male gender (RRR 1.23, 95%-CI 1.06-1.41, p=0.005) and diabetes mellitus (RRR 1.68, 95%-CI 1.47-1.92, p<0.001). Hypercholesterolemia was less prevalent in patients with lesions below the knee (RRR 0.82, 95%-CI 0.71-0.94, p=0.006), whereas no distinct pattern was apparent related to arterial hypertension. CONCLUSION: Clinical phenotype of peripheral atherosclerosis varies with prevalence of cardiovascular risk factors suggesting differences in mechanisms involved in iliac as compared with infrageniculate lesions. Identification of molecular mechanism might have influence on future therapeutic strategies in PAD patients. 相似文献
5.
Murat Hamit Aytar Fikret Doğulu Berker Cemil Ertan Ergün Gökhan Kurt Kemali Baykaner 《Child's nervous system》2007,23(6):719-721
Introduction Iniencephaly, a neural tube defect involving occiput and inion and combined with rachischisis of the cervical, thoracic spine,
and retroflexion position of the head is a very rare congenital abnormality of the fetus–newborn with a 0.1–10 of 10,000 prevalence.
This abnormality’s prognosis is thought to be dismal. This abnormality can be associated with other abnormalities such as
anencephaly, encephalocele, hydrocephalus, cyclopia, absence of the mandible, cleft lip and palate, cardiovascular disorders,
diaphragmatic hernia, renal abnormalities, overgrowth of the arms compared to the legs, and club food and gastrointestinal
atresia.
Discussion Most of the patients are dead born, and the others die in a few hours. There are only six previously documented long-term
survivors. In our case, our patient with iniencephalic signs and findings is still living. She is 2 years old now. We think
that this patient presents a mild form of iniencephaly. 相似文献
6.
7.
Hyo-Chang Kim Seok-Gu Kang Pil-Woo Huh Do Sung Yoo Kyoung Suok Cho Dal Soo Kim 《Journal of clinical neuroscience》2007,14(11):1135-1139
Pituitary abscess is a rare and potentially lethal condition. Pituitary abscess in a pregnant woman has not been previously described. A 38-year-old pregnant woman (34 weeks gestation) with a pituitary mass complained of a progressive headache and sudden visual impairment. She was afebrile and had no inflammatory symptoms on admission. On MRI, the preoperative diagnosis was pituitary adenoma with sphenoid sinusitis. She underwent an uncomplicated transsphenoidal procedure for removal of the pituitary mass. The next day, labor commenced and a healthy preterm baby was delivered. Pathologic examination of the intrasellar mass showed polymorphonuclear cells, debris and no tumor cells. The sellar contents were cultured and Streptococcus viridans was grown. To our knowledge this is the first case of pituitary abscess reported during pregnancy. Although the patient was pregnant, the transsphenoidal approach was safe for the mother and the fetus. Surgical drainage and antibiotic therapy are required for the definitive treatment of this condition. 相似文献
8.
9.
Aluminum contamination of infant formulas 总被引:1,自引:0,他引:1
W W Koo L A Kaplan S K Krug-Wispe 《JPEN. Journal of parenteral and enteral nutrition》1988,12(2):170-173
This study aims to determine the extent of aluminum (Al) contamination in whole milk, milk formulas, and other nutrient products commonly used for infants. Similar products from different manufacturers and different lots were measured for Al using electrothermal atomic absorption technique. Aluminum measurements were made directly from the samples or after reconstitution or dilution with Al-free water. Aluminum content was lowest (less than 50 micrograms/liter) in human milk, whole cow milk, and products that appear to require minimal manufacture processing and have few additives such as skim milk, cow milk with 2% fat, bottled glucose water, and sterile water. Highest Al levels (up to 2346 micrograms/liter) were found in highly processed and modified formulas including soy formula, preterm infant formula, and formulas for specific metabolic disorders. Aluminum content of humanized cow milk formula and bottled glucose-electrolyte solution were between the two ranges and usually less than 400 micrograms/liter. There were no significant differences in Al content of similar products from different manufacturers. Liquid formula stored in glass bottles has highest Al content compared to that stored in steel cans or powder preparation of the same product (p less than 0.05). Thus there are marked differences in Al loading depending on the type of formula, whether it is a powder or liquid preparation and the type of storage container. We speculate that raw materials such as soybean, additives such as calcium and phosphorus, manufacturing processes and storage containers are potential sources of contamination of infant formulas. 相似文献