收费全文 | 6100篇 |
免费 | 277篇 |
国内免费 | 9篇 |
耳鼻咽喉 | 95篇 |
儿科学 | 377篇 |
妇产科学 | 100篇 |
基础医学 | 820篇 |
口腔科学 | 108篇 |
临床医学 | 386篇 |
内科学 | 1091篇 |
皮肤病学 | 139篇 |
神经病学 | 369篇 |
特种医学 | 109篇 |
外科学 | 795篇 |
综合类 | 192篇 |
一般理论 | 5篇 |
预防医学 | 446篇 |
眼科学 | 190篇 |
药学 | 710篇 |
中国医学 | 36篇 |
肿瘤学 | 418篇 |
2023年 | 54篇 |
2022年 | 169篇 |
2021年 | 274篇 |
2020年 | 143篇 |
2019年 | 187篇 |
2018年 | 207篇 |
2017年 | 122篇 |
2016年 | 181篇 |
2015年 | 219篇 |
2014年 | 281篇 |
2013年 | 286篇 |
2012年 | 488篇 |
2011年 | 471篇 |
2010年 | 258篇 |
2009年 | 198篇 |
2008年 | 341篇 |
2007年 | 301篇 |
2006年 | 315篇 |
2005年 | 244篇 |
2004年 | 221篇 |
2003年 | 198篇 |
2002年 | 146篇 |
2001年 | 113篇 |
2000年 | 110篇 |
1999年 | 101篇 |
1998年 | 46篇 |
1997年 | 34篇 |
1996年 | 24篇 |
1995年 | 21篇 |
1994年 | 19篇 |
1993年 | 30篇 |
1992年 | 59篇 |
1991年 | 37篇 |
1990年 | 34篇 |
1989年 | 60篇 |
1988年 | 45篇 |
1987年 | 22篇 |
1986年 | 30篇 |
1985年 | 29篇 |
1984年 | 25篇 |
1983年 | 38篇 |
1981年 | 13篇 |
1980年 | 18篇 |
1979年 | 23篇 |
1978年 | 13篇 |
1975年 | 11篇 |
1973年 | 18篇 |
1972年 | 13篇 |
1971年 | 12篇 |
1970年 | 13篇 |
Methods: Retrospective study of 42 patients.
Results: The mean age at presentation of conjunctival melanoma was 43 years (median, 45 years; range, 9–78 years). There were 20 (48%) males and 22 (52%) females. Nineteen patients (45%) had a known history of a preexisting pigmented conjunctival lesion. Bulbar conjunctiva (n = 28; 67%) was the most common tumor epicenter, and medial ocular surface quadrant (n = 15; 36%) was more commonly involved. The mean tumor basal diameter was 12 mm (median, 10 mm; range, 4–30 mm), and the mean tumor thickness was 4 mm (median, 2 mm; range, 1–30 mm). Majority of the patients had a pigmented tumor (n = 33; 79%). The tumors arose de novo (n = 17, 41%) or were associated with conjunctival nevus (n = 9; 21%) or primary acquired melanosis (n = 16, 38%). Wide excisional biopsy, adjunctive cryotherapy, and amniotic membrane grafting were performed in 27 (71%) patients, 11 (29%) underwent orbital exenteration, and 4 were lost to follow-up prior to definitive treatment. Over a mean follow-up period of 24 months (median, 9 months; range, <1 to 136 months), four (11%) patients had tumor recurrence, seven (18%) had locoregional lymph node metastasis, and four (11%) developed systemic metastasis and died due to metastatic disease.
Conclusion: Conjunctival melanoma predominantly occurs in middle-aged Asian Indians and is associated with a high rate of systemic metastasis and death. 相似文献
Context
Quality of life (QoL) is increasingly recognized as an important outcome of cancer treatment. Previous studies have examined clinical predictors of QoL, but with the increasing prevalence of wearable sensors that monitor sleep and activity patterns, further investigation into whether these behaviors are predictive of post-treatment QoL is now feasible. Among patients receiving aggressive cancer treatment such as hematopoietic cell transplantation (HCT), analysis of circadian rhythms (24-hour patterns of sleep and activity) via wearable sensors is limited.Objective
To evaluate the relationship between overall QoL and circadian rhythms in patients receiving allogeneic HCT.Methods
Patients wore an ActiGraph GT3X (Pensacola, FL) activity monitor for at least 72 hours before the initiation of conditioning chemotherapy and transplantation and completed a QoL (Functional Assessment of Cancer Therapy-General [FACT-G]) assessment. QoL assessments were also completed 1, 3, and 6 months after HCT.Results
Patients (n = 45, M age = 55) were mostly male (66%) with a total FACT-G score of 80.96 (SD = 16.05) before HCT. Mixed models revealed robust cross-sectional associations between overall QoL and multiple circadian rhythmicity parameters, including durations of high physical activity, overall circadian rhythmicity, and earlier starts of daily activity (P's < .01). Recovery of QoL after transplant was predicted by longer pre-transplant durations of high physical activity (P = .04) and earlier evening retirement (P = .04).Conclusion
Our findings suggest that wearable sensor information is a promising method of predicting recovery of QoL after HCT. Additional studies are needed to confirm these findings in a larger sample. 相似文献Study design: This was a case-control study of women evaluated and delivered at our institution from 2011 to 2015. Spontaneous PTD was defined as delivery before 37 weeks due to spontaneous preterm labor or premature rupture of membranes. Patient with multifetal gestation and those with medically indicated term or PTD were excluded.
Results: Of 877 women meeting the inclusion criteria, 173 delivered preterm and 704 delivered at term, and 8.1% had high free β-hCG in one or both trimesters. High maternal first and/or second trimester free β-hCG (≥95th percentile) was associated with lower rates of PTD. Thirty-two women with high free β-hCG in both first and second trimesters delivered at term. Gestational age at delivery and birth weights were lower in women who did not have high free β-hCG in any trimester. Low free β-hCG (≤5th percentile) in either trimester was not associated with an increased or decreased likelihood of PTD. Logistic regression demonstrated an independent association of high free β-hCG (≥95th percentile) with a reduced likelihood of PTD. Stratified analysis revealed a stronger impact of this association in women with no prior history of PTD.
Conclusions: High free β-hCG, in the absence of risk factors for medically indicated PTD, is associated with a reduced likelihood of spontaneous PTD and may represent a marker indicating lower risk. 相似文献