全文获取类型
收费全文 | 11331篇 |
免费 | 371篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 439篇 |
妇产科学 | 256篇 |
基础医学 | 744篇 |
口腔科学 | 177篇 |
临床医学 | 741篇 |
内科学 | 2744篇 |
皮肤病学 | 175篇 |
神经病学 | 544篇 |
特种医学 | 216篇 |
外科学 | 1628篇 |
综合类 | 805篇 |
一般理论 | 5篇 |
预防医学 | 1758篇 |
眼科学 | 210篇 |
药学 | 798篇 |
2篇 | |
中国医学 | 238篇 |
肿瘤学 | 240篇 |
出版年
2023年 | 109篇 |
2022年 | 208篇 |
2021年 | 316篇 |
2020年 | 307篇 |
2019年 | 762篇 |
2018年 | 658篇 |
2017年 | 388篇 |
2016年 | 207篇 |
2015年 | 224篇 |
2014年 | 441篇 |
2013年 | 447篇 |
2012年 | 385篇 |
2011年 | 419篇 |
2010年 | 331篇 |
2009年 | 319篇 |
2008年 | 309篇 |
2007年 | 298篇 |
2006年 | 244篇 |
2005年 | 176篇 |
2004年 | 107篇 |
2003年 | 119篇 |
2002年 | 91篇 |
2001年 | 94篇 |
2000年 | 92篇 |
1999年 | 60篇 |
1998年 | 54篇 |
1997年 | 44篇 |
1996年 | 41篇 |
1995年 | 38篇 |
1994年 | 39篇 |
1993年 | 41篇 |
1992年 | 27篇 |
1991年 | 28篇 |
1989年 | 17篇 |
1988年 | 22篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 294篇 |
1984年 | 499篇 |
1983年 | 407篇 |
1982年 | 408篇 |
1981年 | 347篇 |
1980年 | 328篇 |
1979年 | 400篇 |
1978年 | 290篇 |
1977年 | 202篇 |
1976年 | 289篇 |
1975年 | 262篇 |
1974年 | 262篇 |
1973年 | 246篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《The ocular surface》2020,18(1):108-113
PurposeAromatase inhibitors (AIs) limit the synthesis of oestrogen in peripheral tissues thus lowering levels of oestrogen. The primary aim was to evaluate whether women treated with AIs have altered dry eye symptoms and signs. A sub-aim was to investigate whether symptoms of dry eye in postmenopausal women were associated with symptoms of non-eye pain, ocular pain and self-rated pain perception.MethodsThis cross-sectional, observational, single visit study recruited 56 postmenopausal women (mean age 64.1 + 7.9 years) and 52 undergoing AI treatment (mean age 66.6 + 9.0). Ocular symptoms (OSDI, MGD14) and pain questionnaires (PSQ, OPAS) were administered and signs of dry eye and meibomian gland dysfunction were evaluated.ResultsAlmost half of each group reported dry eye symptoms, defined as OSDI>12 (48% control, 46% AI). The PSQ score was significantly higher in the AI group (p = 0.04). Neither frequency or severity of dry eye (or MGD) symptoms scores were significantly different between groups. In the AI group, meibomian gland expressibility score was worse (p = 0.003); there were no differences in any other signs. Higher OSDI scores were associated with higher OPAS eye-pain scores (r = 0.49, p < 0.001), but not OPAS non-eye pain (r = 0.09, p = 0.35). Pain perception (PSQ) showed a moderate positive association with OPAS eye-pain (r = 0.30, p = 0.003).ConclusionsIn this study elevated ocular symptoms were observed in both the AI treated and the untreated groups, with no difference between the groups. Women undergoing AI treatment for early stage breast cancer had worse meibum expressibility score and increased pain perception compared to an untreated group of women. 相似文献
2.
New Zealand Emergency Medicine Network: A collaboration for acute care research in New Zealand 下载免费PDF全文
The specialty of emergency medicine in Australasia is coming of age. As part of this maturation there is a need for high‐quality evidence to inform practice. This article describes the development of the New Zealand Emergency Medicine Network, a collaboration of committed emergency care researchers who share the vision that New Zealand/Aotearoa will have a world‐leading, patient‐centred emergency care research network, which will improve emergency care for all, so that people coming to any ED in the country will have access to the same world‐class emergency care. 相似文献
3.
《Burns : journal of the International Society for Burn Injuries》2019,45(7):1553-1561
BackgroundKnowledge of the epidemiology of burn-related fatalities is limited, with most previous studies based on hospital and burn centre data only.AimsTo describe the epidemiological characteristics of all burn-related fatalities in Australia and New Zealand, and to identify any trends in burn-related fatality incidence over the study period.MethodsData from the National Coronial Information System, including data for pre-hospital and in-hospital burn-related fatality cases, was used to examine the characteristics of burn-related fatalities occurring in Australia and New Zealand from 2009 to 2015. Burn-related fatality rates per 100,000 population were estimated, and incidence trends assessed using Poisson regression analysis.ResultsOf the 310 burn-related fatalities that occurred in Australia and New Zealand, 2009–2015, 41% occurred in a pre-hospital setting. Overall, most burn-related fatality cases were fire related, occurred at home, and were of people aged 41–80 years. One quarter of all burn-related fatalities were a result of intentional self-harm. The population incidence of all burn-related fatalities combined, and for NSW, decreased over the study period.ConclusionsThis study has identified the importance of examining all burn-related fatalities. If this is not done, vulnerable population subgroups will be missed and prevention efforts poorly targeted. 相似文献
4.
Pascal Thomas Gilbert Massard Henri Porte Christophe Doddoli Xavier Ducrocq Massimo Conti 《European journal of cardio-thoracic surgery》2006,29(6):880-885
Objective: To investigate on the feasibility, safety, and effectiveness of a new bioabsorbable material for lung staple-line reinforcement. Methods: This prospective open trial included 66 patients (mean age of 56 ± 17 years) who underwent various types of lung resection using staplers with knitted calcium alginate sleeves for buttressing (FOREseal™, Laboratoires Brothier, Nanterre, France) at three academic centers: 29 lobectomies, 22 emphysema surgeries, 15 wedge resections or lung biopsies. Intraoperative air leakage was assessed at a mean respiratory peak pressure of 30 cmH2O, and rated as grade 1, 2, or 3. Persistent air leakage in the postoperative course, as well as any relevant event, was assessed daily. The follow-up period was of 6 months. Results: No technical problem linked to the device occurred. Hemostasis of the cutting edges was completed in all patients. Fifty-six percent of the patients had no intraoperative air leak and 27.3% had grade 1 leaks. Mean postoperative air leaks and thoracic drainage times were 1.9 ± 2.3 days and 6 ± 5.3 days, respectively. In-hospital mortality was nil. There was no empyema. Mean hospital stay was 9.1 ± 6.6 days. At follow-up, one patient underwent lung transplantation, and pathology of the explanted specimen showed the absence of device-related foreign-body inflammation. One patient complained from metalloptysis, and another one, with a metastatic invasive aspergillosis, developed an infectious recurrence that required reoperation. Conclusions: FOREseal is an ergonomic, safe, and promising new material instead of nonabsorbable materials and xenomaterials for staple-line reinforcement. A randomized comparative study is now in progress. 相似文献
5.
6.
J. E. P. Rockell C. M. Skeaff S. M. Williams T. J. Green 《Osteoporosis international》2006,17(9):1382-1389
Introduction Vitamin D plays an important role in bone health. Our purpose was to measure serum 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=2,946) of New Zealanders aged 15 years and over.Findings Mean (99% CI) serum 25-hydroxyvitamin D concentrations were 47 (45–50) nmol/l in women and 52 (49–55) nmol/l in men. Mean concentrations in New Zealand European and Others (NZEO, n=2,440), Mori (n=370), and Pacific (n=136) were 51 (49–53), 42 (38–46) and 37 (33–42) nmol/l, respectively. Three percent of New Zealanders had serum 25-hydroxyvitamin D concentrations indicative of deficiency (≤17.5 nmol/l); 48% and 84% were insufficient based on cutoffs of ≤50 and ≤80 nmol/l. Determinants of serum 25-hydroxyvitamin D concentrations in women were age, ethnicity, obesity, latitude and season; determinants in men were ethnicity and season. Serum 25-hydroxyvitamin D in women declined with age; mean concentration was 13 (8–18) nmol/l lower in women 65 years or older and 9 (5–13) nmol/l lower in women 45–64 years compared with women 15–18 years. Spring to summer differences in serum 25-hydroxyvitamin D were 31 (28–34) and 28 (25–31) nmol/l in women and men, respectively. Obese women had lower vitamin status than normal-weight women by 6 (3–10). Women living in the South Island had a mean serum 25-hydroxyvitamin D that was 6 (3–9) nmol/l lower than women living in the North Island. Ethnicity and season are the major determinants of serum 25-hydroxyvitamin D in New Zealanders.Conclusion The high prevalence of vitamin D insufficiency in New Zealanders, particularly in older women, may warrant strategies to improve vitamin D status. 相似文献
7.
Mitsumasa Iwata Shunji Izuta Motoshi Suzuki Kiyohide Kojima Yoshihito Furuhashi Yutaka Tomoda Shonen Yoshida 《Cancer science》1991,82(4):433-439
We examined the mechanisms of the inhibition of DNA synthesis by a new platinum compound, (-)-( R )-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-platinum(II) monohydrate (DWA-2114R), a derivative of the antitumor drug cis- diamminedichloroplatinum(II) (CDDP), using prokaryotic and eukaryotic DNA polymerases. Preincubating activated DNA with CDDP or DWA-2114R reduced its template activity for prokaryotic and eukaryotic DNA polymerases in a dose-dependent manner. DWA2114R required six times greater drug concentration and two times longer incubation time to show the same decrease of the template activity compared to CDDP. Treatment of primed pUC118 ssDNA templates with the two drugs followed by second-strand synthesis by prokaryotic and eukaryotic DNA polymerases revealed that DWA2114R bound to DNA in a similar manner to CDDP and these adducts blocked DNA elongation by DNA polymerases of eukaryotes as well as of prokaryotes. With these two drugs, the elongations by E. coli DNA polymerase I (Klenow fragment), T7 DNA polymerase and calf thymus DNA polymerase α were strongly arrested at guanine-guanine sequences (GG). Stop bands were also observed at adenine-guanine sequences (AG) guanine-adenine-guanine sequences (GAG) and mono-guanine sequence (G). Calf testis DNA polymerase β was also arrested efficiently at AG, GAG and G, but much more weakly at GG. This pattern was common to DWA2114R and CDDP. 相似文献
8.
报告了从辽宁省部分地区腹泻和感染标本中检出的成团肠杆菌、非脱羧勒克氏菌、克吕沃尔氏菌、彭氏变形菌、霍堆氏肠杆菌的分离、鉴定,药敏试验及致病性研究结果.部分菌株可引起动物、生物模型病变,证明有致病力.与人的腹泻和感染有关.致病性研究中,溶血性阳性率最高,依次为乳鼠灌胃,HeP—2细胞、Vero细胞病变,兔肠袢结扎.豚鼠角膜侵袭试验无阳性.药敏试验证实,5组细菌抗药谱已很广,临床可用的敏感药物不多,一旦发生感染,治疗将十分困难. 相似文献
9.
10.