全文获取类型
收费全文 | 1218篇 |
免费 | 111篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 41篇 |
妇产科学 | 13篇 |
基础医学 | 214篇 |
口腔科学 | 32篇 |
临床医学 | 151篇 |
内科学 | 314篇 |
皮肤病学 | 24篇 |
神经病学 | 135篇 |
特种医学 | 14篇 |
外科学 | 157篇 |
综合类 | 8篇 |
一般理论 | 3篇 |
预防医学 | 111篇 |
眼科学 | 11篇 |
药学 | 65篇 |
中国医学 | 5篇 |
肿瘤学 | 27篇 |
出版年
2023年 | 17篇 |
2022年 | 30篇 |
2021年 | 35篇 |
2020年 | 26篇 |
2019年 | 34篇 |
2018年 | 45篇 |
2017年 | 36篇 |
2016年 | 31篇 |
2015年 | 32篇 |
2014年 | 55篇 |
2013年 | 64篇 |
2012年 | 86篇 |
2011年 | 105篇 |
2010年 | 52篇 |
2009年 | 47篇 |
2008年 | 72篇 |
2007年 | 70篇 |
2006年 | 41篇 |
2005年 | 62篇 |
2004年 | 63篇 |
2003年 | 41篇 |
2002年 | 40篇 |
2001年 | 21篇 |
2000年 | 30篇 |
1999年 | 20篇 |
1998年 | 11篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1977年 | 5篇 |
1973年 | 3篇 |
1971年 | 6篇 |
1970年 | 4篇 |
1968年 | 6篇 |
1967年 | 3篇 |
排序方式: 共有1331条查询结果,搜索用时 10 毫秒
1.
Vilar-Compte Mireya Gaitán-Rossi Pablo Félix-Beltrán Lucía Bustamante Arturo V. 《Journal of immigrant and minority health / Center for Minority Public Health》2022,24(1):65-77
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to... 相似文献
2.
Denis O'Mullane PhD ; Helen P. Whelton PhD ; Pat Costelloe BDS David Clarke BDS ; Stephen McDermott MSc ; Jacinta McLoughlin MDS 《Journal of public health dentistry》1996,56(5):259-264
The visit of Dr. Trendley Dean to Dublin in the mid-1950s helped accelerate the decision to introduce water fluoridation as a public health measure in the prevention of caries in the Republic of Ireland. A challenge to the constitutional validity of the Health (Fluoridation of Water Supplies) Act 1960 failed and in 1964 the water supplies of Dublin city were fluoridated. Over the next seven to eight years all the major urban communities in the Republic of Ireland were fluoridated. Currently, 67 percent of the 3.5 million people in the country reside in fluoridated communities. Studies conducted over the last 20 years show that residents of fluoridated communities have better dental health than those in nonfluoridated communities—the mean dmft is lower in children and the number of natural teeth present in adults is higher. 相似文献
3.
Suicide within the construction industry in Queensland, Australia was reportedly high in a recent Royal Commission report. The current study examined the incidence and causes of suicide in this industry using psychological autopsy and focus group investigations. A total of 64 male suicides occurred over the seven-year period, representing a crude suicide rate of 40.3 per 100,000, significantly greater than the working age Australian male rate. Young employees were at excessive risk with separation/divorce, relationship problems, and untreated psychiatric conditions the major contributors. Focus groups emphasized the importance of work/home interface factors and industry-specific factors preceding suicide. 相似文献
4.
Four multiband compression limiters and two linear amplification systems were compared in terms of the intelligibility of consonant-vowel-consonant (CVC) nonsense syllables for two hearing-impaired listeners over a 30 dB range of input levels. Each system incorporated one of two frequency-gain characteristics and one of three limiting characteristics (no limiting, moderate limiting, or severe limiting). The subjects were instructed to choose overall listening levels that would permit speech spanning the range of input levels to be as intelligible as possible and comfortable for long-term listening. Relative to linear amplification, the overall gain selected by the subjects increased by roughly 5 and 11 dB for the moderate and severe limiter, respectively. With linear amplification, the maximum score, 82 percent correct, was obtained at the highest input level and scores fell roughly 34 percentage points as input level was reduced. With compression limiting, although the maximum scores, 81 percent and 79 percent correct, were obtained at lower input levels, performance was comparable to that with linear amplification. Also, scores spanned a range of only 22 and 9 percentage points across the range of input levels with the moderate and severe limiter, respectively. This benefit was due to the improved scores provided by compression limiting at the low input levels. However, this advantage was offset somewhat by the disadvantage provided by compression at high input levels relative to linear amplification. Error analysis indicated that the spectral degradations introduced by independent compression of 16 frequency bands may have caused the reduced intelligibility at higher input levels. 相似文献
5.
T Pelissier H F Miranda D Bustamante C Paeile G Pinardi 《Journal of pharmacological and toxicological methods》1992,27(1):41-44
The endothelial layer was removed from the isolated mesenteric vascular bed of the rat by perfusion with hypotonic Tyrode solution for 12.5 min. This procedure damaged more than 95% of the endothelial cells. After endothelial removal, the response to norepinephrine was significantly enhanced, whereas the relaxation induced by acetylcholine (ACh) was completely abolished. The results of this work show that perfusion with hypotonic solutions provides a reliable method of endothelial removal in isolated perfused vascular beds, allowing the study of endothelial-dependent vascular responses. 相似文献
6.
Estie Kruger Marc Tennant Kirrilee Smith Jacinta Peachey 《Australasian journal on ageing》2007,26(1):15-20
Objectives: The aim of this study was to assess, in a sample of older rural community‐dwelling Australians, their: oral health status, dental treatment needs, perceived barriers to access dental services and the prevalence and severity of dental anxiety. Methods: A cross‐sectional study of elderly rural Australians. Results: Eighty participants (mean age of 71.7 years) had a mean number of 0.69 (SD 1.6) decayed teeth, 15.72 (SD 13.3) missing teeth and 3.9 (SD 5.4) filled teeth. Forty‐one per cent were edentulous. Xerostomia was reported by 53% of the edentulous and 43% of the dentate. The average Corah Dental Anxiety Scale score was 8.72 (SD 3.8). Prevalence of dental anxiety was 15.6%. Two‐thirds needed dental treatment. Conclusions: Caries experience was lower than that reported in other studies. Reported barriers to use of dental services were long waiting times, lack of perceived dental need and costs. 相似文献
7.
Northern Ireland has one of the lowest breastfeeding initiation rates in the world. Given that attitudes toward infant feeding are formed at an early age and a high rate of teenage pregnancy, it has become necessary to survey attitudes to infant feeding and breastfeeding promotion preferences in teenagers in Northern Ireland. Questionnaires were distributed to teenagers aged 14 to 18 years (n = 419) based in 7 schools selected by type and location throughout Northern Ireland. Attitudes to breastfeeding in public reflected preferred infant-feeding method and were positively influenced by prior exposure to breastfeeding (P = .024). Females were more positive than males both in relation to breastfeeding in public (P = .002) and breastfeeding promotion (P = .003). Recommendations for breastfeeding promotion include specific targeting of young people (both male and female) and enabling contact between teenagers and nursing mothers as much as possible. 相似文献
8.
Pilar Bustamante Ma Angeles Pea Jerome Barra 《The Journal of pharmacy and pharmacology》1998,50(9):975-982
The expanded Hansen method was tested for determination of the solubility parameters of two non-steroidal anti-inflammatory drugs, naproxen and sodium diclofenac. This work describes for the first time the application of the method to the sodium salt of a drug. The original dependent variable of the expanded Hansen method, involving the activity coefficient of the drug, was compared with the direct use of the logarithm of the mole fraction solubility lnX2 in the solubility models. The solubility of both drugs was measured in pure solvents of several chemical classes and the activity coefficient was obtained from the molar heat and the temperature of fusion. Differential scanning calorimetry was performed on the original powder and on the solid phase after equilibration with the pure solvents, enabling detection of possible changes of the thermal properties of the solid phase that might change the value of the activity coefficient. The molar heat and temperature of fusion of sodium diclofenac could not be determined because this drug decomposed near the fusion temperature. The best results for both drugs were obtained with the dependent variable lnX2 in association with the four-parameter model which includes the acidic and basic partial-solubility parameters δa and δb instead of the Hansen hydrogen bonding parameter δh. Because the dispersion parameter does not vary greatly from one drug to another, the variation of solubility among solvents is largely a result of the dipolar and hydrogen-bonding parameters, a fact that is being consistently found for other drugs of small molecular weight. These results support earlier findings with citric acid and paracetamol that the expanded Hansen approach is suitable for determining partial-solubility parameters. The modification introduced in the expanded Hansen method, i.e. the use of lnX2 as the dependent variable, provides better results than the activity coefficient used in the original method. This is advantageous for drugs such as sodium diclofenac for which the ideal solubility cannot be estimated. This paper shows for the first time that the method is suitable for determination of the partial-solubility parameters of a sodium salt of a drug, sodium diclofenac. 相似文献
9.
A malformed child with a recombinant chromosome 7, rec(7) dup p, derived from a maternal pericentric inversion inv(7)(p15q36). 下载免费PDF全文
A Delicado E Escribano I Lopez Pajares A Diaz de Bustamante S Carrasco 《Journal of medical genetics》1991,28(2):126-127
We report a child with facial dysmorphic features, hypoplasia of the external genitalia, intestinal malrotation, congenital cardiac defect, and minor limb anomalies. Chromosome studies showed a recombinant chromosome 7, rec(7) dup p, resulting from a maternal pericentric inversion inv(7)(p15 q36). Thus, this child had partial trisomy 7p in addition to a small distal monosomy 7. The clinical findings are compared with those found in previous reports of trisomy 7p. Finally, some general principles for genetic counselling are discussed. 相似文献
10.
Bladder acellular matrix as a substrate for studying in vitro bladder smooth muscle-urothelial cell interactions 总被引:17,自引:0,他引:17
Brown AL Brook-Allred TT Waddell JE White J Werkmeister JA Ramshaw JA Bagli DJ Woodhouse KA 《Biomaterials》2005,26(5):529-543
The objective of this study was to evaluate the ability of bladder acellular matrix (BAM) to support the individual and combined growth of primary porcine bladder smooth muscle (SMC) and urothelial (UEC) cells. An in vitro co-culture system was devised to evaluate the effect of UEC on (i) SMC-mediated contraction of BAM discs, and (ii) SMC invasiveness into BAM. Cells were seeded onto BAM discs under 4 different culture conditions. Constructs were incubated for 1, 7, 14 and 28 days. Samples were then harvested for evaluation of matrix contraction. Immunohistochemistry (IHC) was utilized to examine cellular organization within the samples and conditioned media supernatants analyzed for net gelatinase activity. BAM contraction was significantly increased with co-culture. The same side co-culture configuration lead to a greater reduction in surface area than opposite side co-culture. IHC revealed enhanced SMC infiltration into BAM when co-culture was utilized. A significant increase in net gelatinase activity was also observed with the co-culture configuration. Enhanced infiltration and contractile ability of bladder SMCs with UEC co-culture may, in part, be due to an increase in gelatinase activity. The influence of bladder UECs on SMC behaviour in vitro indicates that BAM may contain some key inductive factors that serve to promote important bladder cell-cell and cell-matrix interactions. 相似文献