全文获取类型
收费全文 | 1546篇 |
免费 | 165篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 30篇 |
妇产科学 | 69篇 |
基础医学 | 306篇 |
口腔科学 | 50篇 |
临床医学 | 186篇 |
内科学 | 273篇 |
皮肤病学 | 11篇 |
神经病学 | 85篇 |
特种医学 | 25篇 |
外科学 | 205篇 |
综合类 | 50篇 |
一般理论 | 1篇 |
预防医学 | 211篇 |
眼科学 | 4篇 |
药学 | 131篇 |
肿瘤学 | 77篇 |
出版年
2023年 | 10篇 |
2022年 | 26篇 |
2021年 | 53篇 |
2020年 | 38篇 |
2019年 | 42篇 |
2018年 | 44篇 |
2017年 | 38篇 |
2016年 | 33篇 |
2015年 | 36篇 |
2014年 | 55篇 |
2013年 | 55篇 |
2012年 | 91篇 |
2011年 | 81篇 |
2010年 | 64篇 |
2009年 | 40篇 |
2008年 | 61篇 |
2007年 | 68篇 |
2006年 | 56篇 |
2005年 | 82篇 |
2004年 | 42篇 |
2003年 | 29篇 |
2002年 | 51篇 |
2001年 | 41篇 |
2000年 | 38篇 |
1999年 | 41篇 |
1998年 | 18篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 18篇 |
1994年 | 11篇 |
1992年 | 24篇 |
1991年 | 18篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 14篇 |
1987年 | 29篇 |
1986年 | 23篇 |
1985年 | 25篇 |
1984年 | 16篇 |
1983年 | 10篇 |
1979年 | 18篇 |
1977年 | 12篇 |
1974年 | 10篇 |
1973年 | 10篇 |
1972年 | 17篇 |
1971年 | 19篇 |
1970年 | 17篇 |
1969年 | 11篇 |
1967年 | 13篇 |
1966年 | 9篇 |
排序方式: 共有1720条查询结果,搜索用时 31 毫秒
41.
Amy L. Gentzler Meagan A. Ramsey Katelyn R. Black 《Attachment & human development》2013,15(4):376-398
This study investigated how mothers’ attachment was related to their responses to their own and their children’s positive events and positive affect (PA). Ninety-seven mothers reported on their attachment and their responses to their own and their 7–12-year-old children’s positive events and emotions. Children reported on their mothers’ responses to the children’s positive events and their attachment security with their mothers. The results indicated that more avoidant mothers reported less intense PA in response to their own and their children’s positive events. More avoidant mothers also were less likely to encourage their children to savor positive events (through expressing PA, reflecting on PA or themselves, giving rewards, and affectionate responses). Mothers higher on anxiety reported greater likelihood of dampening (e.g., minimizing the event’s importance) their own positive events and reported being more likely to feel discomfort and to reprimand their children for expressing PA. Children’s security was predicted by mothers’ lower likelihood of encouraging children’s dampening and of reprimanding children for PA displays. This study advances the literature on how mothers’ attachment is related to the ways in which they regulate their own and their children’s PA, which may have implications for children’s attachment and developing PA regulation. 相似文献
42.
43.
Stephen Barclay Katherine Froggatt Clare Crang Elspeth Mathie Melanie Handley Steve Iliffe Jill Manthorpe Heather Gage Claire Goodman 《The British journal of general practice》2014,64(626):e576-e583
Background
Older people living in care homes often have limited life expectancy. Practitioners and policymakers are increasingly questioning the appropriateness of many acute hospital admissions and the quality of end-of-life care provided in care homes.Aim
To describe care home residents’ trajectories to death and care provision in their final weeks of life.Design and setting
Prospective study of residents in six residential care homes in three sociodemographically varied English localities: Hertfordshire, Essex, and Cambridgeshire.Method
Case note reviews and interviews with residents, care home staff, and healthcare professionals.Results
Twenty-three out of 121 recruited residents died during the study period. Four trajectories to death were identified: ‘anticipated dying’ with an identifiable end-of-life care period and death in the care home (n = 9); ‘unexpected dying’ with death in the care home that was not anticipated and often sudden (n = 3); ‘uncertain dying’ with a period of diagnostic uncertainty or difficult symptom management leading to hospital admission and inpatient death (n = 7); and ‘unpredictable dying’ with an unexpected event leading to hospital admission and inpatient death (n = 4). End-of-life care tools were rarely used. Most residents who had had one or more acute hospital admission were still alive at the end of the study.Conclusion
For some care home residents there was an identifiable period when they were approaching the end-of-life and planned care was put in place. For others, death came unexpectedly or during a period of considerable uncertainty, with care largely unplanned and reactive to events. 相似文献44.
The purpose of this study was to determine how the mechanical efficiency of skeletal muscle is affected by level of activation. Experiments were performed in vitro (35 °C) using bundles of fibres from fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of mice. Measurements were made of the total work and heat produced in response to 10 brief contractions. Mechanical efficiency was the ratio of total work performed to (total heat produced + work performed). Level of activation was varied by altering stimulation frequency between 40 and 160 Hz. Efficiency did not differ significantly between the two muscle types but was significantly lower using 40 Hz stimulation (mean efficiency ± SEM, 0.092?±?0.012, n?=?12, averaged across EDL and soleus) than at any of the other frequencies (160 Hz: 0.147?±?0.007, n?=?12). Measurements of the partitioning of energy output between force-dependent and force-independent components enabled calculation of the amount of Ca2+ released and number of cross-bridge cycles performed during the contractions. At 40 Hz stimulation frequency, less Ca2+ was released than at higher frequencies and fewer cross-bridge cycles were performed. Furthermore, less work was performed in each cross-bridge cycle. It is concluded that skeletal muscles are less efficient at low levels of activation than when fully activated and this indicates that level of activation affects not only the number of cycling cross-bridges but also the ability of individual cross-bridges to perform work. 相似文献
45.
Meagan A. Barry Misha V. Koshelev Grace S. Sun Sarah J. Grekin Charles E. Stager A. Hafeez Diwan Carina A. Wasko Kristy O. Murray Laila Woc-Colburn 《The American journal of tropical medicine and hygiene》2014,91(2):345-347
Cutaneous leishmaniasis is rarely seen in the United States. Four Cuban immigrants traveled along the same route at different times from Cuba to Ecuador, then northward, including through the Darién Jungle in Panama. These patients had chronic ulcerative non-healing skin lesions and were given a diagnosis of leishmaniasis.Leishmaniasis is a vector-borne disease caused by the protozoan parasite of the genus Leishmania and is spread by the bite of sand flies from the sub-family Phlebotominae.1 There are various clinical manifestations of leishmaniasis, including cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis, and visceral leishmaniasis. Cutaneous leishmaniasis occurs at the site of the bite, with lesions forming weeks to months later starting with a papule, which then develops into a nodule or plaque-like lesion and progresses to a painless ulceration with an indurated border.We report four cases of CL caused by Leishmania (Viannia) panamensis in Cuban immigrants who traveled through the Darién Gap Jungle between Colombia and Panama on their journey north to the United States. This region has been shown to have high transmission rates of leishmaniasis,2 and, in 2012, Panama experienced an outbreak beyond expected endemic rates.3 This case series highlights a previously underappreciated immigration route to the United States for Cubans and the need to include leishmaniasis as a differential diagnosis for non-healing skin ulcers in this patient population.During May 2012–April 2013, four persons who had recently immigrated to the United States from Cuba came to the National School of Tropical Medicine at Baylor College of Medicine''s (BCM) Tropical Medicine Clinic for non-healing skin ulcers. All four persons reported a similar route of travel from Cuba to Texas (Figure 1), although at different times. Each person began their journey by flying to Quito, Ecuador, where they then traveled by bus through Colombia, passing through the cities of Pasto and Cali to Quibdo. In Quibdo, they took a short flight to Bahia Solano, Colombia, where a boat ride then transported them to Punta Ardita near the Panama border. They then traveled by foot through the thick jungle in Darién, Panama, for 5–15 days. During this time, they slept outdoors and reported numerous insect bites. Once through the Darién area, they traveled northward until they entered the United States at the Mexican border.Open in a separate windowFigure 1.Map showing immigration route of a cluster of Cuban patients with cutaneous leishmaniasis caused by Leishmania (V.) panamensis. Note the travel by foot through the thick jungle of the Darién National Park, Panama, where they likely contracted the disease.Once in the United States, the four persons sought medical care at outside clinics for skin lesions that had developed within two months after they passed though the Darién. They were treated for presumed infection with Staphylococcus aureus. The antibiotics had no therapeutic effect, and the lesions continued to grow and develop into non-healing, painless ulcers with accompanying satellite lesions. Once in Houston, Texas, the four persons were directed to the Department of Dermatology at BCM (Patient Age, years/sex Lesion location; size; presence of satellite lesions (+/−) Diagnosis and pathogen Duration of disease before initiation of treatment Treatment course 1 38/F Proximal right posterior arm; 5 cm; (+) CL L. (V.) panamensis 3 months AmBisome (days 1–5, 14, 21) 2 46/M Distal left forearm; 2 lesions: 4 cm and 3 cm; (+) CL L. (V.) panamensis 2 months AmBisome (days 1–5, 14, 21); then itraconazole (daily, 30 days) 3 43/M Vertex of scalp, 8 more lesions on eyes, legs, and torso; 5 cm, other lesions 1 cm; (+) CL L. (V.) panamensis 2 weeks AmBisome (days 1–5); then pentostam (daily, 20 days) 4 43/F Left malar area; 1.5 cm; (+) CL L. (V.) panamensis 3 months AmBisome (days 1–5, 14)