全文获取类型
收费全文 | 969篇 |
免费 | 56篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 17篇 |
妇产科学 | 5篇 |
基础医学 | 107篇 |
口腔科学 | 27篇 |
临床医学 | 76篇 |
内科学 | 163篇 |
皮肤病学 | 8篇 |
神经病学 | 65篇 |
特种医学 | 11篇 |
外科学 | 152篇 |
综合类 | 21篇 |
预防医学 | 49篇 |
眼科学 | 27篇 |
药学 | 195篇 |
中国医学 | 19篇 |
肿瘤学 | 65篇 |
出版年
2023年 | 8篇 |
2022年 | 16篇 |
2021年 | 33篇 |
2020年 | 15篇 |
2019年 | 40篇 |
2018年 | 31篇 |
2017年 | 27篇 |
2016年 | 28篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 41篇 |
2012年 | 80篇 |
2011年 | 80篇 |
2010年 | 39篇 |
2009年 | 57篇 |
2008年 | 77篇 |
2007年 | 61篇 |
2006年 | 45篇 |
2005年 | 48篇 |
2004年 | 38篇 |
2003年 | 46篇 |
2002年 | 40篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 19篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有1029条查询结果,搜索用时 15 毫秒
81.
The hydroalcoholic extract of the whole plant of Bacopa monniera Wettst. (Scrophulariaceae), exhibited an inhibitory effect on superoxide released from polymorphonuclear (PMN) cells in the nitroblue tetrazolium (NBT) assay. The major saponin bacoside A(3) was found to be responsible for this effect in the herb. This compound showed 85, 91.66, 91.66, and 83 % inhibitions of NBT reduction at the concentrations of 200, 100, 50, and 25 microg/ml, respectively, with an IC(50) value of 10.22 microg/ml. These inhibitory effects were compared with those of the standard positive controls, quercetin and ascorbic acid with IC(50) of 111 and 14.16 microg/ml, respectively. Another major saponin bacopasaponin C was found to be much less potent as compared to bacoside A(3) whereas the remaining two mixtures of saponins were found to be inactive. 相似文献
82.
Joshua M Dziba Regina Marcinek Gopalakrishnan Venkataraman Jill A Robinson Kenneth B Ain 《Thyroid》2002,12(12):1063-1070
Anaplastic thyroid carcinoma (ATC) is a fatal malignancy the clinical outcome of which is unaltered by current therapeutic modalities. A recent phase 1 clinical trial of combretastatin A4 phosphate (CA4P) produced a long-lasting total remission in a patient with ATC. CA4P is a tubulin-binding agent derived from the African bush willow, Combretum caffrum, which possesses tumor vascular-targeting activity. In order to discriminate primary antineoplastic effects from tumor antivascular activity, we evaluated CA4P cytotoxicity in eight human ATC cell lines and compared it to paclitaxel, another tubulin-binding agent with significant clinical activity. CA4P displayed significant cytotoxicity against the ATC cell lines, comparable to that of paclitaxel, and these effects were longer lasting in two cell lines compared to the duration of paclitaxel. We further investigated the effects of CA4P on xenograft tumors from four ATC cell lines injected in athymic nude mice. Significantly lower tumor weights were observed in animals treated with CA4P compared to those treated with vehicle alone. Continuous monitoring of xenograft tumor volumes from one of the ATC cell lines also revealed a significantly lower rate of tumor growth in the CA4P-treated mice compared to those receiving vehicle alone. These results suggest that antitumoral effects of CA4P can be consequent to a combination of primary antineoplastic effects as well as the potential destruction of tumor vasculature. 相似文献
83.
Gopalakrishnan S Thilagam H Raja PV 《Archives of environmental contamination and toxicology》2007,52(2):171-178
The toxicity of heavy metals to marine invertebrates has been widely investigated; however, the effects on marine sedentary
polychaetes have largely been ignored. The toxicity of copper, aluminium, lead, nickel, and zinc on fertilization, embryogenesis,
and larvae of Hydroides elegans was examined in laboratory acute-toxicity tests. Exposure to metal during fertilization or early developmental stages leads
to fertilization block and arrested development, which resulted in morphologic abnormalities in embryo and larvae. Fertilization
rate showed a drastic decrease at the highest metal concentration tested. Embryos of H. elegans showed a differential response to metals, and the responses were stage-specific. The different morphologic effects of heavy
metals reflect differentiation of the early embryonic cells. For individual metals, the toxicity ranking for 24−hour trochophore
larvae was Cu > Al > Pb > Ni > Zn, with EC50 values of 0.122, 0.210, 0.231, 0.316, and 0.391 mg l−1, respectively. Rate of larval development and embryogenesis were the most sensitive end points, although the latter is more
advisable for routine assessment of seawater quality because of its greater simplicity. In addition to bivalves and sea urchins,
polychaete embryos can provide biologic criteria for seawater quality taking into account the sensitivity of a polychaete
and contributing to the detection of harmful chemicals with no marked effect on the species currently in use in seawater quality
bioassays. 相似文献
84.
Does financial disadvantage at older ages eliminate the potential for better health? 总被引:2,自引:0,他引:2
Montgomery SM Netuveli G Hildon Z Blane D 《Journal of epidemiology and community health》2007,61(10):891-895
OBJECTIVE: Taller adult stature reflects early life advantages and is an indicator of improved economic and health outcomes, and thus the potential for better health, including reduced depression risk. As inadequate retirement pension provision is an increasing concern, we investigated whether health potential (indicated by height) was realised among those experiencing financial disadvantage in later life. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study of the population in England aged over 50 years and not resident in an institution. Participants (n = 9106) were members of the English Longitudinal Study of Ageing. MAIN OUTCOME MEASURE: Depression assessed using the eight-item Center for Epidemiological Studies Depression Scale. RESULTS: Stratification by the lowest quintile of the net financial assets distribution defined adversity, and stature was dichotomised at the shortest quintile of height (sex standardised). After adjustment for sex, qualifications, occupation type, whether currently employed, age, ethnic origin and chronic illness, taller stature was associated with a statistically significant reduced risk of depression with an odds ratio of 0.7 (95% confidence interval 0.6 to 0.9) among those without financial disadvantage. No protection against depression was associated with taller stature among those with financial disadvantage (odds ratio 1.0; 95% confidence interval 0.8 to 1.3). Interaction testing confirmed effect modification by financial disadvantage for the association of height with depression (p = 0.005). CONCLUSIONS: Although taller stature, indicating favourable childhood conditions, is associated with a decreased risk of depression, this benefit is eliminated by financial disadvantage at older ages. Adequate financial provision for older people is required to maximise the health potential imparted by beneficial conditions in earlier life. 相似文献
85.
86.
Ricardo A. Weis Patrick A. Devaleria Sarang Koushik Harish Ramakrishna 《Annals of cardiac anaesthesia》2015,18(4):467-473
Introduction:
Advances in medical and surgical care have made it possible for an increasing number of patients with Congenital Heart disease (CHD) to live into adulthood. Transposition of the great vessels (TGV) is the most common cyanotic congenital cardiac disease where the right ventricle serves as systemic ventricle. It is not uncommon for these patients to have systemic ventricular failure requiring transplantation.Study Design:
Hemodynamic decompensation in these patients can be swift and difficult to manage. Increasingly percutaneous LVAD''s such as the Impella (Abiomed, Mass, USA) are gaining popularity in these situations owing to their relative ease of placement, both in and outside of the operating room.Conclusion:
In this paper we demonstrate that Impella (IMP) CP placement through the axillary artery approach shows to be suitable option for short term cardiac support and improvement of end organ perfusion in anticipation of cardiac transplantation. 相似文献87.
Subcutaneous bortezomib combined with weekly cyclophosphamide and dexamethasone is an efficient and well tolerated regime in newly diagnosed multiple myeloma 下载免费PDF全文
88.
Excellent mechanical, electrical, and thermal properties of graphene have been achieved at the macroscale by assembling individual graphene or graphene oxide (GO) particles. Wet-spinning is an efficient and well-established process that can provide GO assemblies in fiber form. The coagulation bath in the wet-spinning process has rarely been considered for the design of mechanically robust GO fibers (GOFs). In this study, locating the amidation reaction in the coagulation bath yielded mechanically improved GOFs. The imides 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide were used to form covalent amide bonds between GO flakes and chitosan, thereby reinforcing the GOFs. Evidence and effects of the amidation reaction were systematically examined. The tensile strength and breaking strain of the GOFs improved by 41.6% and 75.2%, respectively, and the toughness almost doubled because of the optimized crosslinking reaction. Our work demonstrated that using a coagulation bath is a facile way to enhance the mechanical properties of GOFs.Excellent mechanical, electrical, and thermal properties of graphene have been achieved at the macroscale by assembling individual graphene or graphene oxide (GO) particles. 相似文献
89.
Choudhrie AV Kumar S Gopalakrishnan G 《Saudi journal of kidney diseases and transplantation》2012,23(1):99-101
Amoebic liver abscess (ALA) is by far the most common extraintestinal manifestation of invasive amoebiasis. The vast majority of these resolve with treatment; however, a small percentage of the treated ALAs are known to persist asymptomatically. Herein, we present a prospective renal allograft recipient with a residual liver abscess who had a successful renal transplant after treatment. In our opinion, persistence of a radiological finding of residual abscess in the absence of clinical disease does not appear to be a contraindication to renal transplantation. 相似文献
90.