全文获取类型
收费全文 | 1634664篇 |
免费 | 133153篇 |
国内免费 | 2720篇 |
专业分类
耳鼻咽喉 | 22071篇 |
儿科学 | 55027篇 |
妇产科学 | 46814篇 |
基础医学 | 231604篇 |
口腔科学 | 48138篇 |
临床医学 | 143371篇 |
内科学 | 320540篇 |
皮肤病学 | 35010篇 |
神经病学 | 132053篇 |
特种医学 | 65647篇 |
外国民族医学 | 474篇 |
外科学 | 248842篇 |
综合类 | 40767篇 |
现状与发展 | 3篇 |
一般理论 | 558篇 |
预防医学 | 124572篇 |
眼科学 | 37737篇 |
药学 | 124648篇 |
4篇 | |
中国医学 | 3267篇 |
肿瘤学 | 89390篇 |
出版年
2018年 | 15990篇 |
2016年 | 14085篇 |
2015年 | 16190篇 |
2014年 | 22378篇 |
2013年 | 33292篇 |
2012年 | 45260篇 |
2011年 | 47376篇 |
2010年 | 27922篇 |
2009年 | 26525篇 |
2008年 | 44740篇 |
2007年 | 46967篇 |
2006年 | 47601篇 |
2005年 | 46068篇 |
2004年 | 45382篇 |
2003年 | 43261篇 |
2002年 | 42195篇 |
2001年 | 76165篇 |
2000年 | 78752篇 |
1999年 | 66756篇 |
1998年 | 17928篇 |
1997年 | 16491篇 |
1996年 | 16475篇 |
1995年 | 16159篇 |
1994年 | 15183篇 |
1993年 | 14316篇 |
1992年 | 55646篇 |
1991年 | 53978篇 |
1990年 | 52773篇 |
1989年 | 51036篇 |
1988年 | 47385篇 |
1987年 | 46713篇 |
1986年 | 44414篇 |
1985年 | 42985篇 |
1984年 | 32140篇 |
1983年 | 27635篇 |
1982年 | 16190篇 |
1981年 | 14493篇 |
1980年 | 13608篇 |
1979年 | 30526篇 |
1978年 | 21121篇 |
1977年 | 17819篇 |
1976年 | 16736篇 |
1975年 | 17612篇 |
1974年 | 21523篇 |
1973年 | 20714篇 |
1972年 | 18884篇 |
1971年 | 17805篇 |
1970年 | 16320篇 |
1969年 | 15281篇 |
1968年 | 13979篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
M Shibata T Ohkubo H Takahashi T Kudo R Inoki 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》1986,88(2):101-107
Opiates and opioid peptides were administered in the order of 10(-9)-10(-6) mol peripherally, and their action on pain sensitivity was investigated by the modified formalin test which has two characteristic pain responses (the first and the second phase) in the mouse hindpaw. Opioid peptides (20-500 pmol) had dose-dependent analgesia against both first and second phases, and their action ranked dynorphin greater than [D-Ala2, Met5]-enkephalinamide greater than [Met5]-enkephalin. EKC and morphine (0.4-2.5 nmol) inhibited pain response of the first phase, but produced hyperalgesia in the second phase dose-dependently. Lidocaine hydrochloride had peripheral analgesic action, but was about 500-10000 times weaker than these substances. So, these peripheral analgesic actions have a different mechanism from that of local anesthetic action. N-methyl levallorphan which is thought to be a peripherally selective narcotic antagonist reversed these peripheral analgesic actions at the first and second phases and also prevented the hyperalgesic effects of EKC and morphine at the second phase. Naloxone reversed analgesia at only the first phase. These results suggest that an analgesic mechanism by opioids may exist at the peripheral site as well. Furthermore, it is estimated that a receptor exists which is antagonized by N-methyl levallorphan but not by naloxone and that there is a system of hyperalgesia by EKC and morphine in pain modulation. 相似文献
942.
In the present paper, the results obtained are shown after a study by means of multivariant statistical analysis, of the quantity of Eimeria spp. oocyst elimination in sheep, bearing in mind the variations observed in the different areas, in the different age-groups, from month to month, and from year to year. Climatic factors, development of immunity, lambing seasons, and poor hygienic conditions seem to be the factors responsible for the statistically significant differences found when analysing the aforementioned main effects. 相似文献
943.
The incidence of AIDS among blacks and Hispanics 总被引:3,自引:0,他引:3
R Bakeman E McCray J R Lumb R E Jackson P N Whitley 《Journal of the National Medical Association》1987,79(9):921-928
Compared with whites, the acquired immune deficiency syndrome (AIDS) has affected blacks and Hispanics disproportionately. The cumulative incidence (CI) for black men was 2.6, and for Hispanic men 2.5, times the rate for white men. Intravenous (IV) needle use alone does not account for this difference. Not counting IV needle-using cases, the CIs for black and Hispanic men were 1.7 times the CI for white men. Although there were fewer cases in women than men, the white-to-minority disparity was greater for women. The CIs for black and Hispanic women were 12.2 and 8.5 times, respectively, the CI for white women. Prevention programs are urgently needed and should focus on risky behavior (IV needle sharing and receptive anal intercourse), not just risk groups. 相似文献
944.
945.
Penny H Feldman Christopher M Murtaugh Liliana E Pezzin Margaret V McDonald Timothy R Peng 《Health services research》2005,40(3):865-886
OBJECTIVE: To assess the impact and cost-effectiveness of two information-based provider reminder interventions designed to improve self-care management and outcomes of heart failure (HF) patients. DATA SOURCES/STUDY SETTING: Interview and agency administrative data on 628 home care patients with a primary diagnosis of HF. STUDY DESIGN: Patients were treated by nurses randomly assigned to usual care or one of two intervention groups. The basic intervention was an e-mail to the patient's nurse highlighting six HF-specific clinical recommendations. The augmented intervention supplemented the initial nurse reminder with additional clinician and patient resources. DATA COLLECTION: Patient interviews were conducted 45 days post admission to measure self-management behaviors, HF-specific outcomes (Kansas City Cardiomyopathy Questionnaire-KCCQ), health-related quality of life (EuroQoL), and service use. PRINCIPAL FINDINGS: Both interventions improved the mean KCCQ summary score (15.3 and 12.9 percent, respectively) relative to usual care (p< or =.05). The basic intervention also yielded a higher EuroQoL score relative to usual care (p< or =.05). In addition, the interventions had a positive impact on medication knowledge, diet, and weight monitoring. The basic intervention was more cost-effective than the augmented intervention in improving clinical outcomes. CONCLUSIONS: This study demonstrates the positive impact of targeting evidence-based computer reminders to home health nurses to improve patient self-care behaviors, knowledge, and clinical outcomes. It also advances the field's limited understanding of the cost-effectiveness of selected strategies for translating research into practice. 相似文献
946.
947.
948.
Jennifer M Griffith James R Sorenson J Michael Bowling Tracey Jennings-Grant 《Health education & behavior》2005,32(5):613-626
The Enhancing Patient Prenatal Education study tested the feasibility and educational impact of an interactive program for patient prenatal genetic screening and testing education. Patients at two private practices and one public health clinic participated (N = 207). The program collected knowledge and measures of anxiety before and after use of the tool. Time in various prenatal visit activities was collected prior to and after the introduction of the education tool. Providers completed an assessment of their experiences with patients who had used the program. Results indicate that patient knowledge significantly increased from pre to post (p = .0001) with no increase in anxiety (p = .31). Time in clinic activities, including overall visit time, increased. A majority of providers indicated that the program disrupted clinic flow. This assessment suggests that the program increases patient knowledge and does not increase patient anxiety. However, challenges remain to using this program in a clinic setting. 相似文献
949.
Kelly Garrett Allison Butler Wayne R Cohen 《The journal of maternal-fetal & neonatal medicine》2005,17(1):49-53
OBJECTIVE: To characterize dysfunctional labors that lead to cesarean delivery in the second stage and to assess the accuracy of diagnoses of abnormal fetal descent. METHODS: Thirty-one patients delivered by cesarean during the second stage because of abnormal labor or presumed cephalopelvic disproportion were studied and compared to 62 control cesarean cases delivered for the same indications in the first stage. The clinical diagnosis of dysfunctional labor that led to the cesarean was compared to the diagnosis made by retrospective analysis of the labor curves. RESULTS: Cases did not differ from controls delivered in the first stage in maternal age, race, parity, gestational age, weight gain, or the frequency of associated medical complications. The newborns were not significantly different in birth weight,ponderal index, sex, or the incidence of low Apgar scores. Among study patients, 94% had a second stage labor dysfunction determined by graphic labor analysis, predominantly arrest of descent (69%) and failure of descent (28%). In 79% of cases a dysfunctional first stage preceded the abnormal second stage. Among these first stage labor abnormalities, 68% were not recognized during the labor. CONCLUSION: Characteristics of patients delivered by cesarean during the second stage were similar to those delivered before full cervical dilatation. Second stage labor abnormalities were usually preceded by an abnormal first stage. There was considerable inaccuracy in the diagnosis of second stage labor dysfunction. 相似文献
950.
AIMS: In normotensive women with Type 1 diabetes and microalbuminuria we previously found preterm delivery (< 34 weeks) in 23% of the pregnancies. Antihypertensive treatment was initiated in late pregnancy when preeclampsia was diagnosed and diastolic blood pressure > 90 mmHg. From April 2000 our routine was changed and early antihypertensive treatment with methyldopa was initiated if antihypertensive treatment was given prior to pregnancy, if urinary albumin excretion (UAE) was > 2 g/24 h, or blood pressure > 140/90 mmHg. The present study describes the impact of this more aggressive antiypertensive treatment in the prevalence of preterm delivery. METHODS: The old cohort (1995-1999) consisted of 26 and the new cohort (2000-2003) of 20 pregnant women with Type 1 diabetes and microalbuminuria. All were referred before gestational week 17. RESULTS: The cohorts were comparable with regard to age, diabetes duration, prepregnancy body mass index, HbA1c, blood pressure 121 (13)/71 (8) vs. 121 (14)/73 (8) mmHg [mean (sd)] and early UAE 69 (16-278) vs. 74 (30-287) mg/24 h (geometric mean and range). Antihypertensive treatment was initiated in the old cohort at 29 (20-33) weeks, n = 9, and in the new at 13 (0-34) weeks, n = 10. The prevalence of preterm delivery before 34 weeks was reduced from 23% to zero (P = 0.02), preterm delivery before 37 weeks from 62% to 40% (P = 0.15) and preeclampsia from 42% to 20% (P = 0.11). Perinatal mortality occurred in 4% vs. 0%. Birth weight was 3124 (767) g vs. 3279 (663) g. CONCLUSION: Introduction of early antihypertensive treatment with methyldopa in normotensive pregnant women with Type 1 diabetes and microalbuminuria resulted in a significant reduction in preterm delivery before gestational week 34. 相似文献