首页 | 本学科首页   官方微博 | 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   2013篇
  免费   120篇
  国内免费   12篇
耳鼻咽喉   20篇
儿科学   63篇
妇产科学   33篇
基础医学   318篇
口腔科学   13篇
临床医学   272篇
内科学   485篇
皮肤病学   66篇
神经病学   194篇
特种医学   39篇
外科学   181篇
综合类   15篇
一般理论   1篇
预防医学   164篇
眼科学   23篇
药学   125篇
中国医学   5篇
肿瘤学   128篇
  2023年   15篇
  2022年   30篇
  2021年   44篇
  2020年   37篇
  2019年   42篇
  2018年   34篇
  2017年   26篇
  2016年   38篇
  2015年   42篇
  2014年   62篇
  2013年   106篇
  2012年   134篇
  2011年   105篇
  2010年   75篇
  2009年   79篇
  2008年   148篇
  2007年   147篇
  2006年   145篇
  2005年   122篇
  2004年   107篇
  2003年   117篇
  2002年   113篇
  2001年   29篇
  2000年   20篇
  1999年   19篇
  1998年   24篇
  1997年   25篇
  1996年   11篇
  1995年   11篇
  1994年   16篇
  1993年   14篇
  1992年   14篇
  1991年   11篇
  1990年   7篇
  1989年   10篇
  1988年   7篇
  1987年   14篇
  1986年   8篇
  1984年   7篇
  1983年   7篇
  1982年   10篇
  1981年   5篇
  1977年   5篇
  1971年   6篇
  1970年   7篇
  1968年   7篇
  1966年   4篇
  1965年   4篇
  1964年   7篇
  1954年   4篇
排序方式: 共有2145条查询结果,搜索用时 15 毫秒
991.
AIM: This study aimed at determining the association of father's and mother's (parental) substance use disorder (SUD) and discipline styles and son's neurobehavior disinhibition (ND) with son's SUD from childhood (age 10-12) to young adulthood (age 19). It was hypothesized that (1) parental discipline styles and son's ND mediate the association between parental SUD and son's SUD, (2) son's ND mediates the association between parental discipline styles and son's SUD, and (3) parental discipline styles mediate the association between ND and SUD in the son. METHODS: Two-hundred-sixty-three families including a 10-12 year-old son and both parents participated in the study. RESULTS: (1) mother's discipline styles predicted father's discipline styles, (2) son's ND predicted mother's instilling guilt positively and father's punishment negatively, (3) son's ND mediated the association between father's SUD and punishment and son's SUD, and (4) mother's SUD predicted son's ND and SUD. CONCLUSIONS: The reciprocal prediction between son's ND and father's punishment and prediction of father's punishment by mother's punishment point to the need for family-based interventions that take into account the quality of specific dyadic interactions pertaining to discipline behaviors that amplify the risk for SUD in male children.  相似文献   
992.
993.
We enrolled 347 hypertensive patients, randomly allocated them to different first-line treatments, and followed-up for 24 months. Persistence on treatment was significantly higher in patients treated with ARBs (68.5%) and ACE inhibitors (64.5%) vs. CCBs (51.6%), beta-blockers (44.8%), and diuretics (34.4%). No ARB, ACE inhibitor, beta-blocker, or diuretic was associated with a greater persistence in therapy as compared with the other molecules used in each therapeutic class. The rate of persistence was significantly higher in patients treated with lercanidipine vs. other CCBs (59.3% vs. 46.6%). Systolic and diastolic BP decreased more in patients treated with ARBs (-11.2/-5.8 mmHg), ACE inhibitors (-10.5/-5.1 mmHg), and CCBs (-8.5/-4.6 mmHg) when compared to beta-blockers (-4.0/-2.3 mmHg) and diuretics (-2.3/-2.1 mmHg).  相似文献   
994.
Unsatisfactory blood pressure (BP) control in the treated hypertensive patient is largely related to poor compliance with antihypertensive drug regimens. The aim of the present study was to prospectively evaluate the rate of persistence on treatment and the extent of BP control in 301 elderly, uncomplicated grade I or II hypertensive patients randomly allocated to monotherapy with angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), beta-blockers, angiotensin II receptors (ARBs), or diuretics according to an open-label single-blind study design. After 24 months, the percentage of patients continuing their initial therapy was higher in those treated with ARBs (68.5%) and ACE inhibitors (64.5%) and lower in patients taking diuretics (34.4%; P<.01). The logistic regression model using ARBs as reference term showed that patients treated with ACE inhibitors (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.79-0.99) or CCBs (OR, 0.76; 95% CI, 0.54-0.85) were more likely to continue their initial antihypertensive therapy when compared with those treated with beta-blockers (OR, 0.67; 95% CI, 0.57-0.79) or diuretics (OR, 0.56; 95% CI, 0.38-0.84). The average systolic and diastolic BP decrease was greater in patients treated with ARBs (-11.2+/-4/-5.8+/-2 mm Hg), ACE inhibitors (-10.5+/-4/-5.1+/-2 mm Hg), and CCBs (-8.5+/-3/-4.6+/-2 mm Hg) and lesser in those treated with diuretics (-2.3+/-4/-2.1+/-3 mm Hg, P<.05) and beta-blockers (-4.0+/-2/-2.3+/-2 mm Hg; P<.05). The study confirms the importance of persistence with treatment for the effective management of hypertension in clinical practice.  相似文献   
995.
OBJECTIVE: To determine the accuracy of the Gamma G7 (and G5 model) and XXL-LF aneroid sphygmomanometers developed by the Heine Company. DESIGN: Device evaluations were performed using the new protocol of the European Society of Hypertension. Monitor performance was assessed in relation to participants' sex, age, arm circumference, and systolic and diastolic blood pressures. METHODS: The two sphygmomanometers were assessed in two different samples according to European Society of Hypertension requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg, or more. RESULTS: Both sphygmomanometers passed all three phases of the protocol for systolic blood pressure and diastolic blood pressure. Mean blood pressure difference between Gamma G7 sphygmomanometer and observers was -0.4+/-3.3 mmHg for systolic blood pressure and -0.5+/-2.6 mmHg for diastolic blood pressure. Mean differences for the Gamma XXL-LF sphygmomanometer were -0.3+/-3.7 and -1.0+/-2.6 mmHg, respectively. In multivariable analyses, the SBP discrepancies between both aneroid sphygmomanometers and observers were unrelated to age, sex, arm circumference and systolic blood pressure. For diastolic blood pressure, a borderline relationship was found only for arm circumference (P=0.057) with the Gamma G7 device. CONCLUSIONS: These data show that the Heine Gamma G7 and Gamma XXL-LF aneroid sphygmomanometers satisfy the new recommended ESH accuracy levels for both SBP and DBP. Their performance is uniform across subgroups of participants with different clinical characteristics.  相似文献   
996.
This study was carried out to determine the incidence of malaria in an endemic region of Amazonas State, Venezuela. For this, 200 random samples were collected from symptomatic and asymptomatic individuals from San Fernando de Atabapo and Santa Barbara. Epidemiological factors were related to malaria infection, which was diagnosed by microscopy observation and amplification of the 18S rDNA sequence by PCR. Malaria prevalence in these populations was 28.5%, whilst P. vivax and P. falciparum prevalences were 12 and 17%, respectively. No infection by P. malariae was found. A mixed infection was found on an asymptomatic individual. Prevalence patterns differed between age groups depending on the Plasmodium species. We found that 34.8% of the P. vivax and 15.2% of the P. falciparum infections were asymptomatic. The use of nets was helpful to prevent P. vivax infection, but did not protect against P. falciparum infection. The results suggest the presence of more than one mosquito vector in the area, displaying a differential pattern of infection for each Plasmodium species. There appear to be risk factors associated with malaria infections in some individuals. The population based approach and PCR diagnosis improved the accuracy of the statistical analysis in the study.  相似文献   
997.
BACKGROUND: Depression and cognitive impairment in later-life have great bearings on public health. The two conditions often co-occur and have mutual implications on short-term risk and long-term prognosis. METHOD: A two-phase epidemiologic survey on the prevalence of dementia in elders aged 60 and over was conducted in Hong Kong in 2005-2006. In the first phase, 6,100 randomly selected community dwelling elders were assessed with Cantonese version of Mini-Mental State Examination (C-MMSE) and Abbreviated Memory Inventory for Chinese (AMIC). Two thousand and seventy-three subjects were screened positive and invited for second phase cognitive and psychiatric assessment. 35.5% of screen-positive subjects participated in Phase 2 assessment conducted by psychiatrists for diagnosis of dementia. Severity of dementia was determined using Clinical Dementia Rating Scale (CDR). Cornell Scale for Depression in Dementia (CSDD) and a structured bedside cognitive battery were also administered to each subject. RESULTS: 1.7% of subjects with CDR 0.5 and 5.9% of subjects with CDR 1 had clinically significant depressive symptoms (>or= 8 on CSDD). Score on CSDD correlated positively with duration of cognitive symptoms, scores on CIRS and CMMSE in linear regression model. In a logistic regression model, male gender, duration of cognitive symptoms, CIRS and CMMSE was associated with increased risk for clinically significant depressive symptoms. CONCLUSIONS: In our sample, milder forms of cognitive impairment were associated with increased risk for depression in the presence of other risk factors such as male gender, higher physical illness burden and longer duration of cognitive symptoms.  相似文献   
998.
BACKGROUND: The neuropathology of behavioural and psychological symptoms is much less understood than the neuropathology of cognitive impairment in AD. On MRI, medial temporal lobe atrophy (MTA) is presumed to reflect Alzheimer- type pathology. White matter hyperintensities (WMH) are considered markers of vascular pathology. AIM: We investigated differences in prevalence of behavioural and psychological symptoms in AD according to the presence of MTA and WMH on MRI. METHODS: Behavioural and psychological symptoms of 111 consecutive AD patients were assessed using the Neuropsychatric Inventory (NPI). Symptoms were considered present when the score was > or =1. On MRI, MTA was rated using the five-point Scheltens-scale and WMH using the four-point Fazekas-scale. Both MRI measures were dichotomised (MTA: absent 0/1, present 2-4; WMH absent 0/1, present 2/3). RESULTS: Of the 111 AD patients, 60(55%) had MTA, and 32(29%) had WMH. The presence of MTA was associated with the presence of WMH (chi (2) = 11.8, p < 0.001). The prevalence of behavioural and psychological symptoms--defined as a NPI score of > or =1 on at least one symptom--was 74%.The median NPI score of the total study population was 6(0-41). There was no difference in prevalence according to MTA (p = 0.53) or WMH (p = 0.18). On inspection of individual NPI items, neither MTA, nor WMH was related to any of the symptoms. CONCLUSIONS: There were no differences in prevalence of behavioural and psychological symptoms according to MTA or WMH, as rated on MRI. This suggests that the occurrence of those symptoms depends on other determinants, such as coping style or genetic make-up.  相似文献   
999.
1000.
Objective  The purpose of this study was to evaluate the performance of high-resolution ultrasonography in the detection of clinically and mammographically occult breast cancer. Materials and methods  From September 2003 to November 2006, a total of 1485 patients were confirmed to have in situ or invasive breast cancer in Hong Kong Sanatorium and Hospital Breast Care Centre. All patients underwent mammography (MMG) and/ or sonography (USG) evaluation. Patients’ age and size of tumor detected by USG alone were compared with those detected by MMG. Results  Altogether, 222 patients (17%) had positive imaging findings on USG only, among which 22 (13%) patients had nonpalpable tumors. Performing USG increased the cancer detection rate among clinically and mammographically occult breast lesions by 14.3%. The mean size of the tumors detected only by USG was 1.98 cm, which was not significantly different from the mean size of tumor detected by MMG (1.46) (p = 0.23). This remains true in the group of patients with nonpalpable tumors (1.36 vs. 1.46 cm, p = 0.88). The sensitivity of USG is 91%, which is significantly higher than that of MMG (78%) (p = 0.001). This remains true in patients age <40 or ≥40, tumor grading I toIII, and LVI +/− cases. However, MMG had higher sensitivity in the group of patients with nonpalpable tumors (73% vs. 62%, p = 0.01) and noninvasive cancers (72% vs. 69%, p = 0.01). Conclusions  The use of high-resolution USG may lead to detection of a significant number of occult cancers that are no different in size from nonpalpable mammographically detected lesions.  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