全文获取类型
收费全文 | 1840篇 |
免费 | 275篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 40篇 |
妇产科学 | 46篇 |
基础医学 | 292篇 |
口腔科学 | 35篇 |
临床医学 | 277篇 |
内科学 | 260篇 |
皮肤病学 | 34篇 |
神经病学 | 103篇 |
特种医学 | 84篇 |
外科学 | 280篇 |
综合类 | 43篇 |
一般理论 | 1篇 |
预防医学 | 264篇 |
眼科学 | 9篇 |
药学 | 179篇 |
中国医学 | 1篇 |
肿瘤学 | 171篇 |
出版年
2021年 | 27篇 |
2020年 | 31篇 |
2019年 | 25篇 |
2018年 | 42篇 |
2017年 | 24篇 |
2016年 | 34篇 |
2015年 | 27篇 |
2014年 | 56篇 |
2013年 | 43篇 |
2012年 | 91篇 |
2011年 | 80篇 |
2010年 | 46篇 |
2009年 | 33篇 |
2008年 | 62篇 |
2007年 | 88篇 |
2006年 | 79篇 |
2005年 | 74篇 |
2004年 | 79篇 |
2003年 | 60篇 |
2002年 | 71篇 |
2001年 | 52篇 |
2000年 | 64篇 |
1999年 | 57篇 |
1998年 | 21篇 |
1997年 | 21篇 |
1996年 | 20篇 |
1992年 | 32篇 |
1991年 | 44篇 |
1990年 | 36篇 |
1989年 | 46篇 |
1988年 | 59篇 |
1987年 | 42篇 |
1986年 | 34篇 |
1985年 | 39篇 |
1984年 | 32篇 |
1983年 | 30篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 36篇 |
1978年 | 25篇 |
1977年 | 18篇 |
1976年 | 21篇 |
1975年 | 25篇 |
1974年 | 19篇 |
1973年 | 17篇 |
1972年 | 24篇 |
1970年 | 21篇 |
1969年 | 15篇 |
1967年 | 16篇 |
排序方式: 共有2122条查询结果,搜索用时 15 毫秒
111.
Lea RG Hannah LT Redmer DA Aitken RP Milne JS Fowler PA Murray JF Wallace JM 《Pediatric research》2005,57(4):599-604
Most intrauterine growth restriction cases are associated with reduced placental growth. Overfeeding adolescent ewes undergoing singleton pregnancies restricts placental growth and reduces lamb birth weight. We used this sheep model of adolescent pregnancy to investigate whether placental growth restriction is associated with altered placental cell proliferation and/or apoptosis at d 81 of pregnancy, equivalent to the apex in placental growth. Adolescent ewes with singleton pregnancies were offered a high or moderate level of a complete diet designed to induce restricted or normal placental size at term, respectively. Bromodeoxyuridine (Brd-U) was administered to H and M ewes 1 h before slaughter. Placental tissues were examined for a) Brd-U (immunohistochemistry) and b) apoptosis regulatory genes by in situ hybridization, Northern analyses (bax, mcl-1), immunohistochemistry, and Western analyses (bax). Quantification was carried out by image analysis. Total placentome weights were equivalent between groups. Brd-U predominantly localized to the trophectoderm and was significantly lower in the H group. Bax and mcl-1 mRNA were localized to the maternal-fetal interface. Bax protein was significantly increased in the H group and predominant in the uninuclear fetal trophectoderm. These observations indicate that reduced placental size at term may be due to reduced placental cell proliferation and possibly increased apoptosis occurring much earlier in gestation. 相似文献
112.
113.
The analgesic effect of odour and music upon dressing change 总被引:2,自引:0,他引:2
Kane FM Brodie EE Coull A Coyne L Howd A Milne A Niven CC Robbins R 《British journal of nursing (Mark Allen Publishing)》2004,13(19):S4-12
Vascular wounds may require frequent dressing changes over a long period of time, often involving pain, which may not be adequately controlled with conventional analgesia. Complementary analgesia may be beneficial as an adjunctive therapy. This pilot study presented eight patients with two odour therapies, lavender and lemon, two music therapies, relaxing and preferred music and a control condition, during vascular wound dressing changes. Although the therapies did not reduce the pain intensity during the dressing change there was a significant reduction in pain intensity for the lavender therapy and a reduction in pain intensity for the relaxing music therapy after the dressing change. This supports the use of these complementary therapies, which are inexpensive, easy to administer and have no known side effects, as adjunctive analgesia in this patient population. Earlier administration before dressing change may enhance these effects. Further research is required to ascertain why certain complementary therapies are more effective than others at relieving pain. 相似文献
114.
The reservoir bag on the anaesthetic breathing circuit is a safety feature that can protect the patient. It is highly distensible, pressures within the breathing circuit rarely exceeding 3.9 kPa (40 cmH2O) even when the adjustable pressure-limiting valve is inadvertently left closed. In providing a safe latex-free environment in our anaesthetic rooms, the traditional latex rubber reservoir bag is substituted by a latex-free one. To investigate the safety features of several latex-free reservoir bags already in use in our hospital, we assessed the in-circuit pressures obtained at stepped fresh gas flows using a lung simulator. Four out of five of the latex-free bags exceeded pressures of 4.4 kPa (45 cmH2O), raising the possibility that, in trying to avoid an occupational hazard, we might be compromising patient safety. We found that, of the five latex-free systems we tested, only the Intersurgical complete respiratory system provided an adequate safety mechanism for the patient and thus did not potentially compromise patient safety. 相似文献
115.
Liu MD Uaje MB Al-Ghazi MS Fields D Herman J Kuo JV Milne N Nguyen TH Ramsinghani NS Tokita KM Tsai FY Vajgrt DJ Imagawa DK 《The American surgeon》2004,70(11):947-953
This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival. 相似文献
116.
117.
Adams MJ Antoniw JF Bar-Joseph M Brunt AA Candresse T Foster GD Martelli GP Milne RG Zavriev SK Fauquet CM 《Archives of virology》2004,149(5):1045-1060
Summary. The new plant virus family Flexiviridae is described. The family is named because its members have flexuous virions and it includes the existing genera Allexivirus, Capillovirus, Carlavirus, Foveavirus, Potexvirus, Trichovirus and Vitivirus, plus the new genus Mandarivirus together with some related viruses not assigned to any genus. The family is justified from phylogenetic analyses of the polymerase and coat protein (CP) sequences. To help to define suitable molecular criteria for demarcation of species, a complete set of pairwise comparisons was made using the nucleotide (nt) and amino acid (aa) sequences of each fully-sequenced gene from every available accession in the family. Based on the distributions and on inspection of the data, it was concluded that, as a general rule, distinct species have less than ca. 72% identical nt or 80% identical aa between their entire CP or replication protein genes.An erratum to this article can be found at 相似文献
118.
Consideration regarding human aging and sympathetic nervous system activity suggests that old age represents a hyperadrenergic state. With advancing age the sympathetically mediated stress on the body, specifically the cardiovascular system, may outweigh the benefits an intact sympathetic nervous system conveys for short-term survival. Beta blockers temper the effects of the sympathetic nervous system by slowing heart rate and decreasing blood pressure. Recently, beta blockers have been shown to improve outcome and survival following surgery and myocardial infarction, have beneficial effects in patients with heart failure, and may have an antiatherosclerotic effect. We propose that instituting beta receptor blockade pharmacotherapy at an early age will increase longevity by countering the adverse effects of sympathetically mediated stress. 相似文献
119.
OBJECTIVES: To determine whether moderately high or low intakes of zinc adversely affect the copper status of postmenopausal women to result in unfavorable changes in calcium and magnesium metabolism and other indicators of bone turnover. DESIGN: After a 10-day equilibration period in which the diet provided 31.5 micromol (2 mg) Cu and 137.7 micromol (9 mg) Zn/8.4 MJ (2000 kcal), the subjects were randomly divided into two groups, with one group fed the basal diet supplemented to provide 15.7 micromol (1 mg) Cu/8.4 MJ, and the other group fed the same diet supplemented to provide 47.2 micromol (3 mg) Cu/8.4 MJ. After equilibration, both groups were fed the basal diet with no zinc supplemented (provided 45.9 micromol [3 mg] Zn/8.4 MJ) for 90 days; this was followed by another 10-day equilibration period before the basal diet was supplemented with zinc to provide 811 micromol (53 mg)/8.4 MJ for 90 days. SETTING: The metabolic unit of the Grand Forks Human Nutrition Research Center, Grand Forks, ND, USA. SUBJECTS: A total of 28 postmenopausal women recruited by advertisement throughout the United States of America. Among them, 25 women (64.9+6.7 y) completed the study; 21 as designed. RESULTS: The moderately high intake compared to the low intake of zinc increased the excretion of magnesium in the feces and urine, which resulted in a decreased magnesium balance. In the women fed low dietary copper, plasma osteocalcin was higher during the low-zinc than high-zinc dietary period. The urinary excretion of N-telopeptides was increased and the serum calcitonin concentration was decreased by high dietary zinc regardless of dietary copper. CONCLUSIONS: A moderately high intake of zinc (811 micromol/day; 53 mg/day) did not induce changes in copper metabolism that resulted in unfavorable changes in bone or mineral metabolism. However, low dietary zinc (45.9 micromol/day; 3 mg/day) apparently resulted in undesirable changes in circulating calcitonin and osteocalcin. As a moderately high intake of zinc decreased magnesium balance, further study of the possibility that a high intake of zinc is a health concern for individuals consuming less than the recommended amounts of magnesium is warranted. 相似文献
120.
Formulation and feedback: an illustration of two methods for improving access to effective therapies
Milne D Hanner S Woodward K Westerman C 《International journal of health care quality assurance incorporating Leadership in health services》2004,17(4-5):268-274
It is now recognised that therapists require career-long training in order to maintain and improve their expertise. However, training will fail to improve services to clients unless the work environment supports staff in its use. Although this "training transfer" problem is widely acknowledged, to the authors' knowledge the way that the work environment influences clients' access to effective therapies has not been subjected to a detailed and systematic formulation. Therefore, this small study illustrates a suitable formulation, based on the training received by a group of National Health Service (NHS) staff in "psychosocial interventions", and proposes its use as a "feedback fascia" to managers and others. To do this, structured interviews were held with a self-selected sample of n = 20 therapists (mostly nurses) and all of their managers (n = 11) in one NHS Trust. The results indicated an impressive degree of training transfer. It is concluded that staff training can improve clients' access to effective treatments, but that significant organisational support for innovation is required. A feedback fascia can guide such support. 相似文献