全文获取类型
收费全文 | 664篇 |
免费 | 28篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 3篇 |
妇产科学 | 4篇 |
基础医学 | 162篇 |
口腔科学 | 11篇 |
临床医学 | 67篇 |
内科学 | 117篇 |
皮肤病学 | 19篇 |
神经病学 | 37篇 |
特种医学 | 14篇 |
外科学 | 51篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 48篇 |
眼科学 | 16篇 |
药学 | 79篇 |
中国医学 | 8篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 3篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 12篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 9篇 |
2015年 | 30篇 |
2014年 | 24篇 |
2013年 | 31篇 |
2012年 | 80篇 |
2011年 | 54篇 |
2010年 | 31篇 |
2009年 | 27篇 |
2008年 | 54篇 |
2007年 | 38篇 |
2006年 | 34篇 |
2005年 | 41篇 |
2004年 | 41篇 |
2003年 | 32篇 |
2002年 | 32篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 11篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有699条查询结果,搜索用时 15 毫秒
1.
Yun Jeong Lim Young-Ho Kim Geung Hwan Ahn Ho Kwung Chun Woo Young Jang Jun Haeng Lee Hee Jung Son Poong-Lyul Rhee Jae J Kim Seung Woon Paik Byung Chul Yoo Jong Chul Rhee 《Taehan Sohwagi Hakhoe chi》2004,44(6):314-320
BACKGROUND/AIMS: Carcinogenesis is characterized by the abnormal regulation of cell cycle. The abnormal expression of the regulators of cell cycle may be related to the prognosis. Since the clinical significance of the expression of the three proteins in colorectal carcinomas is still controversial, we evaluated the prognostic value of the expression of cyclin E, p27 and mutant p53 in stage II colorectal cancer. METHODS: The expression levels of cyclin E, p27 and mutant p53 proteins in 41 patients with stage II colorectal carcinomas were analyzed by immunohistochemistry. RESULTS: In the univariate analysis, the level of CEA at diagnosis was associated with disease relapse. In the multivariate analysis, the clinicopathological variables such as age, gender, site of primary tumor, tumor size, state of tumor differentiation and preoperative plasma CEA level were not associated with disease relapse. When Kaplan-Meier survival curves were constructed to determine the prognosis, cyclin E, p27 and mutant p53 expressions did not predict poor prognosis. CONCLUSIONS: Our results suggested that the expression of cyclin E, p27 and mutant p53 proteins did not predict the clinical outcome in the stage II colorectal carcinomas. 相似文献
2.
Kim MS Seo KS Seong HS Cho SH Lee HB Hong KD Kim SK Khang G 《Bio-medical materials and engineering》2005,15(3):229-238
p-Carboxyphenoxy propane (CPP) prepolymer consisting of 4 units and sebacic acid (SA) prepolymer consisting of about 10 units were synthesized by reacting CPP and SA in the presence of excess acetic anhydride, respectively. Polyanhydride, poly(CPP-SA) copolymers were copolymerized by a melt polycondensation process with a mixture of CPP and SA prepolymer. Copolymers of average molecular weight up to 110,000 g/mol were achieved. The crystallinity of poly(CPP-SA) copolymers was decreased by the addition of the CPP homopolymer segment to SA homopolymer. Poly(CPP-SA) copolymers gradually degraded for period of 10 days. No large difference of weight loss observed according to molecular weight variation of poly(CPP-SA) copolymers. BCNU release from wafers fabricated by poly(CPP-SA) showed a sustained release pattern with no initial burst and delay of drug release. 相似文献
3.
Chung JH Yang JH Song MJ Cho JY Lee YH Park SY Moon MJ Lim HJ Choi JS Kim JO Shin JS Ahn HK Han JY Kim MY Choi KH Ryu HM 《Journal of Korean medical science》2004,19(1):32-36
The aim of present study was to establish normative data for the distribution of nuchal translucency (NT) thickness in normal Korean fetuses. The data were collected from pregnant women with singleton pregnancies in whom fetal ultrasound was performed and the fetal NT thickness was measured between 11 and 14 weeks of gestation. Among them, a total of 2,577 fetuses with a known normal outcome were included in this study. The distribution of multiple of median (MoM) values of the NT thickness with crown-rump length (CRL) in 10-mm intervals and the 95th percentile of MoM were calculated with the linear regression method. The present study showed that NT measurements increase with increasing CRL and a false positive rate increases with increasing gestational age. Therefore, a fixed cut-off point through the first trimester was not appropriate and each NT measurement should be examined according to the gestational age. The present study offers normative data of the fetal NT thickness in a Korean population, which can be used as reference for screening chromosomal aberrations or other congenital abnormalities in the first trimester. 相似文献
4.
5.
Eom GM Watanabe T Hoshimiya N Khang G 《Medical & biological engineering & computing》2002,40(1):137-143
An investigation was carried out into how stimulation frequency and stimulation history affect the potentiation of muscle
force during 20s of constant stimulation of the two knee extensors in isometric conditions. Stimulation frequency significantly
affected the potentiation pattern: low-frequency (2.5–10 Hz) stimulation showed a reduction and subsequent enhancement of
force, and high-frequency (14.3–25 Hz) stimulation showed only enhancement of force. The degree of enhancement in force and
time-to-peak decreased with the stimulation frequency. Whereas conditioning stimulation (both 40 Hz and 14.3 Hz) significantly
enhanced the muscle force above 85%, following main stimulation (14.3 Hz) after short rest (10 s and 50 s, respectively) induced
little force enhancement (below 8%). In particular, when the frequency of the conditioning stimulation was 14.3 Hz, the initial
force at the main stimulation showed a very similar value to the final force value of the conditioning stimulation (above
90% similarity). The potentiated twitch force slowly decayed during rest, with an average time constant of 2.4 min. These
observations indicate that muscle potentiation depends on the stimulation frequency and stimulation history, and therefore
a computer model of potentiation can play an important role in predicting muscle force and body movement induced by electrical
stimulation. 相似文献
6.
7.
8.
9.
Khang D. Nguyen Jiali Han Tricia Li Abrar A. Qureshi 《Archives of dermatological research》2014,306(6):555-560
Little data on cutaneous squamous cell carcinoma (SCC) epidemiology within the United States are currently available. Prior studies have focused on populations outside of the United States or been limited to regions within the US. In this study, prospective data were collected via biennial questionnaires from a total of 261,609 participants, which included women in the Nurses’ Health Study (NHS, 1976–2008) and Nurses’ Health Study II (NHS II, 1989–2009), and men in the Health Professionals Follow-Up Study (HPFS, 1986–2008). History of physician-diagnosed invasive SCC was confirmed by pathology record review. Over the entire follow-up period for each cohort, there were 1,265 invasive SCC cases per 100,000 persons in the NHS cohort, 389 cases per 100,000 persons in NHS II, and 2,154 cases per 100,000 persons in HPFS. An 18-year follow-up of participants in these cohorts revealed increasing invasive SCC incidence rates over time, with rates for men being consistently higher than those for women. In women, a larger proportion of invasive SCC lesions occurred on the lower extremities as compared to men (21 % in NHS vs. 6 % in HPFS, p < 0.0001; 14 % in NHS II vs. 6 % in HPFS, p < 0.0001), while in men, a larger proportion occurred on the head/neck (43 % in NHS vs. 60 % in HPFS, p < 0.0001; 48 % in NHS II vs. 60 % in HPFS, p < 0.0001). In summary, invasive SCC incidence rates among US men have been greater than those for women with distinct sites of common occurrence between men and women. 相似文献
10.
Kang MS Park DI Jeen YT Keum B Choi JH Jung SA Kim HS Kim YH Kim WH Kim TI Kim HJ Yang SK Myung SJ Byeon JS Lee MS Jung IK Chung MK Choi H Han DS Song JS 《International journal of colorectal disease》2008,23(2):171-176
Background/aims The possibility of proximal lesion without distal polyps is a weak point of sigmoidoscopic colon cancer screening, but the
clinical significance of distal findings for advanced proximal neoplasm (APN) is uncertain. The aim of this study was to assess
the significance of a distal finding as a predictor of APN.
Materials and methods Asymptomatic patients ≥50 years old were enrolled from among patients who underwent polypectomy at 11 tertiary medical centers
during the Korean Association for the Study of Intestinal Disease prospective study conducted between July 2003 and March
2004. Polyps located distal to the splenic flexure were defined as distal polyps. An advanced neoplasm was defined as a polyp
of ≥10 mm in size, and/or with villous features, and/or with high-grade dysplasia, or invasive cancer. Age, gender, and distal
polyp size, appearance, and histology were analyzed as risk factors of APN. The sensitivity and positive predictive value
of distal polyps for APN were calculated.
Results Data from 826 patients were analyzed. Mean patient age was 60.1 years (range 50–86), and 71.3% were men. APN was found in
98 patients, and 45 (45.9%) patients had no distal polyps. Risk factors of APN were a male gender, distal polyp size, and
an advanced distal neoplasm. Sensitivities of a distal polyp of ≥10 mm and of an advanced distal neoplasm for APN were both
38.8% with positive predictive values of 13.3 and 14.4%, respectively.
Conclusions Although distal colon findings were found to be helpful for predicting APN in asymptomatic patients aged ≥50 years, APN without
distal polyps requires careful consideration. 相似文献