全文获取类型
收费全文 | 2996篇 |
免费 | 159篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 373篇 |
妇产科学 | 106篇 |
基础医学 | 431篇 |
口腔科学 | 74篇 |
临床医学 | 141篇 |
内科学 | 594篇 |
皮肤病学 | 89篇 |
神经病学 | 67篇 |
特种医学 | 71篇 |
外科学 | 390篇 |
综合类 | 111篇 |
一般理论 | 1篇 |
预防医学 | 155篇 |
眼科学 | 118篇 |
药学 | 230篇 |
中国医学 | 14篇 |
肿瘤学 | 153篇 |
出版年
2022年 | 19篇 |
2021年 | 70篇 |
2020年 | 48篇 |
2019年 | 39篇 |
2018年 | 56篇 |
2017年 | 41篇 |
2016年 | 45篇 |
2015年 | 47篇 |
2014年 | 79篇 |
2013年 | 76篇 |
2012年 | 119篇 |
2011年 | 146篇 |
2010年 | 77篇 |
2009年 | 86篇 |
2008年 | 129篇 |
2007年 | 115篇 |
2006年 | 90篇 |
2005年 | 109篇 |
2004年 | 97篇 |
2003年 | 99篇 |
2002年 | 97篇 |
2001年 | 102篇 |
2000年 | 89篇 |
1999年 | 75篇 |
1998年 | 43篇 |
1997年 | 25篇 |
1996年 | 39篇 |
1995年 | 21篇 |
1992年 | 53篇 |
1991年 | 59篇 |
1990年 | 71篇 |
1989年 | 57篇 |
1988年 | 63篇 |
1987年 | 54篇 |
1986年 | 70篇 |
1985年 | 47篇 |
1984年 | 42篇 |
1983年 | 30篇 |
1979年 | 40篇 |
1978年 | 22篇 |
1977年 | 26篇 |
1976年 | 28篇 |
1975年 | 29篇 |
1973年 | 33篇 |
1972年 | 38篇 |
1971年 | 29篇 |
1970年 | 31篇 |
1969年 | 32篇 |
1968年 | 27篇 |
1967年 | 34篇 |
排序方式: 共有3163条查询结果,搜索用时 15 毫秒
131.
132.
An aqueous extract of Moringa oleifera roots was investigated for its estrogenic, anti-estrogenic, progestational and antiprogestational activities. Oral administration of extract progressively increased the uterine wet weight of bilaterally ovariectomized rats. This estrogenic activity was supported by stimulation of uterine histo-architecture. When the extract was given conjointly with estradiol dipropionate (EDP), there was a successive reduction in the uterine wet weight when compared to the gain with EDP alone and uterine histological structures were also inhibited. In the deciduoma test, the highest dose of 600 mg/kg interfered with the formation of deciduoma in 50% of the rats, showing some antiprogestational activity. Doses up to 600 mg/kg of the extract orally failed to induce a decidual response in the traumatized uterus of ovariectomized rats. The antifertility effect of the extract appears to be due to multiple attributes. 相似文献
133.
We hypothesized that prolonged bedside limited-channel amplitude-integrated electroencephalogram (aEEG) monitoring following a standard 1-hour conventional electroencephalogram (cEEG) would increase the detection of subclinical seizures and allow continuous evaluation of the background EEG in neonatal encephalopathy. This may identify complementary roles for these EEG technologies in neonatal units where continuous cEEG monitoring may not be readily available. We prospectively recruited 25 term neonates with a diagnosis of neonatal seizures or encephalopathy. All infants underwent a standard 1-hour cEEG followed by 12 to 24 hours of aEEG monitoring. Data from the aEEG (plus the raw signal) were analyzed by an epileptologist and compared with information obtained from the clinical report of the cEEG. aEEG and cEEG data were available for 24 infants. Results from magnetic resonance imaging (MRI) performed at 7 to 10 days of life were available in 23/24 infants. Background classification on cEEG and aEEG was similar in 83% of patients. Five of 24 infants had normal background on cEEG. Prolonged aEEG detected evolution of background from initially normal to moderately abnormal in an additional four infants. It also detected more subclinical seizures than the 1-hour cEEG in 8/14 infants. Normal background on aEEG and cEEG was associated with normal MRI results, and severe background abnormality (5/24) on both aEEG and cEEG was associated with abnormal MRI results. Data obtained from prolonged aEEG (plus raw EEG) provide similar background activity, enhance seizure detection, and complement standard cEEG in predicting short-term outcomes, based on MRI, in term neonates with seizures or encephalopathy. Limited-channel aEEG technology may provide a pragmatic alternative for longitudinal monitoring of newborn infants with encephalopathy in neonatal units where prolonged video EEG monitoring is not feasible. 相似文献
134.
Three-week-old female rats were fed 0.09 (zinc-deficient), 0.77 (zinc-adequate) or 3.98 (zinc-supplemented) mmol zinc/kg diet in three experimental groups and the palatal mucosa was painted with the water-soluble carcinogen 4-nitroquinoline N-oxide (4NQO) three times a week for 20 weeks. The zinc-supplemented diet seemed to retard the induction of carcinogenesis, whereas a low-zinc diet had the opposite effect. Once initial cellular changes had been induced the supplementary zinc seemed to accelerate their further advancement. Zinc-deficiency in animals fed a copper/zinc low-zinc diet was reflected in the plasma and liver zinc levels as well as in the copper/zinc ratio. The development of cancer was accompanied by a decrease in plasma zinc and an increase in the plasma copper/zinc ratio as well as in the liver zinc. These changes were most remarkable in the zinc-supplemented group. 相似文献
135.
This article is a concise summary of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) with an emphasis on factors relevant to their occurrence in children. It discusses the limitations in the direct application of the current World Society of Abdominal Compartment Syndrome consensus definitions and extrapolation of management practices derived from studying adult patients to the pediatric age group. Techniques that may be used for measuring intra-abdominal pressure (IAP) in children, normal IAP ranges, risk factors for developing ACS as well as current medical and surgical management options in children are discussed. 相似文献
136.
G. Mathur I. Sanchez‐Vargas D. Alvarez K. E. Olson O. Marinotti A. A. James 《Insect molecular biology》2010,19(6):753-763
Controlled sex‐, stage‐ and tissue‐specific expression of antipathogen effector molecules is important for genetic engineering strategies to control mosquito‐borne diseases. Adult female salivary glands are involved in pathogen transmission to human hosts and are target sites for expression of antipathogen effector molecules. The Aedes aegypti 30K a and 30K b genes are expressed exclusively in adult female salivary glands and are transcribed divergently from start sites separated by 263 nucleotides. The intergenic, 5′‐ and 3′‐end untranslated regions of both genes are sufficient to express simultaneously two different transgene products in the distal‐lateral lobes of the female salivary glands. An antidengue effector gene, membranes no protein (Mnp), driven by the 30K b promoter, expresses an inverted‐repeat RNA with sequences derived from the premembrane protein‐encoding region of the dengue virus serotype 2 genome and reduces significantly the prevalence and mean intensities of viral infection in mosquito salivary glands and saliva. 相似文献
137.
The rapid translation from bench to bedside that has been seen in the application of regenerative medicine to cardiology has led to exciting new advances in our understanding of some of the fundamental mechanisms related to human biology. The first generation of cells used in phase I-II trials (mainly bone marrow mononuclear cells) are now entering phase III clinical trials with the goal of producing a cell based therapeutic that can change the outcome of cardiac disease. First generation cell therapy appears to have addressed safety concerns as well as showing ‘activity’ in numerous published meta-analyses. With the knowledge gained to date, the field is moving towards the next generation of cells-the ‘engineered’ cell-that have been developed to display a phenotype that will further enhance the myocardial repair/salvage process. This almanac review covers the latest basic research that may soon have application to humans as well as the results of the latest clinical trials. 相似文献
138.
Ashley C. Schuyler Zoe R. Edelstein Sanyukta Mathur Joseph Sekasanvu Fred Nalugoda Ronald Gray 《Global public health》2017,12(8):1033-1050
Mobility, including migration and travel, influences risk of HIV. This study examined time trends and characteristics among mobile youth (15–24 years) in rural Uganda, and the relationship between mobility and risk factors for HIV. We used data from an annual household census and population-based cohort study in the Rakai district, Uganda. Data on in-migration and out-migration were collected among youth (15–24 years) from 43 communities from 1999 to 2011 (N?=?112,117 observations) and travel among youth residents from 2003 to 2008 (N?=?18,318 observations). Migration and travel were more common among young women than young men. One in five youth reported out-migration. Over time, out-migration increased among youth and in-migration remained largely stable. Primary reasons for migration included work, living with friends or family, and marriage. Recent travel within Uganda was common and increased slightly over time in teen women (15–19 years old), and young adult men and women (20–24 years old). Mobile youth were more likely to report HIV-risk behaviours including: alcohol use, sexual experience, multiple partners, and inconsistent condom use. Our findings suggest that among rural Ugandan youth, mobility is increasingly common and associated with HIV-risk factors. Knowledge of patterns and characteristics of a young, high-risk mobile population has important implications for HIV interventions. 相似文献
139.
Villareal RP Mathur VS 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2000,27(4):346-349
Internal mammary arteries are the grafts of choice for coronary artery bypass because they are generally free of atherosclerosis and they have high patency rates as grafts. There are, however, increasing reports of graft failure due to diffuse or distal narrowing, known as the string phenomenon. From June 1999 to October 1999, we prospectively reviewed all cases of internal mammary artery angiography at our institution. Twenty-eight cases of internal mammary artery graft failure were identified (M:F, 15:13; mean age, 62 years) out of 261 patients who had undergone internal mammary artery grafting at any institution, including ours. The mean interval between coronary artery bypass and re-angiography was 35 months. There was evidence of competitive flow in 81% (22 of 27) of patients whose internal mammary grafts had developed the string sign. This observational study supports the hypothesis that competitive flow predisposes internal mammary grafts to the string phenomenon. Given the high frequency of competitive flow situations amongst patients with internal mammary artery graft failure, caution should be exercised in the anastomosis of the internal mammary artery to recipient vessels that are less than severely stenosed. 相似文献
140.
Cellular composition including lymphocyte subsets in preterm and full term human colostrum and milk.
The cellular composition of colostrum (within 72 hours post partum) and mature milk samples (5th-7th day post partum) from 20 mothers delivering preterm babies and 20 mothers delivering full term babies was examined. Lymphocyte subsets including T cells, B cells, T4 and T8 cells were quantitated by indirect immunoperoxidase staining using specific monoclonal antibodies. The mean total cell count in preterm colostrum (9,338/mm3) was significantly higher than in full term colostrum (5,594/mm3). Similarly, counts for macrophages, neutrophils and lymphocytes were significantly higher in preterm colostrum and milk as compared to full term colostrum and milk. B and T lymphocytes including T4 and T8 cells were identified in both preterm and full term breast milk. The absolute count of T, B, T4 and T8 cells was significantly higher in preterm colostrum compared to term colostrum, though the relative percentage distribution of lymphocyte subsets showed no significant difference between the two groups. T and B cells constituted about 74% and 26% of total lymphocytes, respectively in preterm as well as full term colostrum and about 69% and 31% in preterm and full term milk. The mean T4/T8 ratio was higher in preterm colostrum than term colostrum, being 1.82 and 1.60 respectively. However, this difference was not significant statistically and did not change statistically in the milk sample. 相似文献