全文获取类型
收费全文 | 1580篇 |
免费 | 86篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 136篇 |
妇产科学 | 18篇 |
基础医学 | 223篇 |
口腔科学 | 12篇 |
临床医学 | 147篇 |
内科学 | 298篇 |
皮肤病学 | 30篇 |
神经病学 | 53篇 |
特种医学 | 148篇 |
外科学 | 78篇 |
综合类 | 178篇 |
预防医学 | 97篇 |
眼科学 | 25篇 |
药学 | 120篇 |
中国医学 | 5篇 |
肿瘤学 | 97篇 |
出版年
2023年 | 13篇 |
2022年 | 39篇 |
2021年 | 56篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 27篇 |
2017年 | 29篇 |
2016年 | 48篇 |
2015年 | 56篇 |
2014年 | 69篇 |
2013年 | 72篇 |
2012年 | 105篇 |
2011年 | 97篇 |
2010年 | 87篇 |
2009年 | 58篇 |
2008年 | 72篇 |
2007年 | 61篇 |
2006年 | 55篇 |
2005年 | 55篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 29篇 |
2001年 | 41篇 |
2000年 | 26篇 |
1999年 | 24篇 |
1998年 | 50篇 |
1997年 | 46篇 |
1996年 | 35篇 |
1995年 | 22篇 |
1994年 | 29篇 |
1993年 | 23篇 |
1992年 | 10篇 |
1991年 | 15篇 |
1990年 | 14篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 28篇 |
1986年 | 14篇 |
1985年 | 15篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 15篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1970年 | 11篇 |
排序方式: 共有1682条查询结果,搜索用时 15 毫秒
21.
The prevalence of microalbuminuria was assessed in 50 patients of non-insulin dependent diabetes mellitus. The mean age of patients was 52.1 ± 11.6 years and the duration of diabetes was 8.3 ± 6.8 years. Twenty (40%) patients had microalbuminuria. Microalbuminuria was more common in patients with a longer duration of diabetes (more than 5 years), a poor glycaemic control, and higher systolic blood pressure.KEY WORDS: Microalbuminuria, Diabetes mellitus, Diabetic nephropathy, Chronic renal failure 相似文献
22.
AS Harvey 《Journal of paediatrics and child health》2003,39(8):640-640
23.
24.
WF Paterson E McNeill S Reid AS Hollman MD Donaldson 《Archives of disease in childhood》1998,79(4):323-327
OBJECTIVE: To assess the efficacy of a longer acting preparation of the gonadotrophin releasing hormone (GnRH) analogue goserelin (Zoladex LA, 10.8 mg) in 12 girls with central precocious or early puberty. METHODS: Two girls started treatment de novo; the remainder had been on suppressive treatment for a median duration of 1.5 (range, 0.2-5.6) years. Assessment comprising auxology, pubertal staging, and pelvic ultrasound examination was carried out at weeks 0, 4, 8, 10, and 12 (first cycle) and weeks 8, 10, and 12 (second cycle) to evaluate the required injection frequency. Thereafter, assessment was performed on the day of injection. Zoladex LA was given every 12 weeks unless pubertal progression occurred. RESULTS: Satisfactory control was achieved in eight patients using this regimen, and three patients required more frequent injections. One girl was removed from the study because of clinical progression and extreme mood swings. No serious adverse effects occurred. Mean height velocity during the study period was 4.5 cm/year (range, 3.1-6.6) compared with 6.5 cm/year (range, 3.8-9.6) before treatment in nine patients for whom data were available. CONCLUSIONS: Zoladex LA was effective in controlling precocious puberty in girls when given at intervals of 9-12 weeks and it is recommended that an initial assessment is made eight weeks after beginning treatment. 相似文献
25.
Mutation of the p53 tumor suppressor gene in spontaneously occurring osteosarcomas of the dog 总被引:8,自引:0,他引:8
Inactivation of the p53 tumor suppressor gene has been implicated in the
pathogenesis of numerous human cancers, including osteosarcomas.
Appendicular osteosarcomas of the dog appear to be a good model for their
human equivalent with regard to biologic behavior, epidemiology and
histopathology. We individually screened exons 5-8 of the p53 gene for
mutations in 15 canine appendicular osteosarcomas using 'Cold' SSCP to
compare the role of this gene in human and canine osteosarcoma
tumorigenesis. Seven of the tumors (47%) exhibited point mutations, with
one tumor possessing two mutations within different exons. Of these, seven
were missense mutations and the eighth was a 'silent' mutation potentially
affecting the exon 6-7 splicing region. Five of the missense mutations were
located in highly conserved regions IV and V, while another corresponded
with the highly conserved codon 220 mutational hotspot located outside the
conserved domains. The locations and types of mutations were nearly
identical to those reported in human cancer. These findings provide strong
evidence of the involvement of p53 mutations in the development of canine
appendicular osteosarcomas. Canine osteosarcomas appear to be a promising
model for their human equivalent on a clinical, pathologic, and molecular
level.
相似文献
26.
One hundred patients of Diabetes Mellitus (70 with and 30 without clinical somatic neuropathy) were studied to correlate clinical severity with the magnitude of nerve conduction abnormalities. Age range was 10-79 years (mean 49) with equal number of males and females. Incidence of neuropathy was more in patients over 40 years of age (60 out of 70 patients) with duration of disease over two years (78.33%). The grades of severity were mild in 22 (31.33%), moderate in 25 (35.71%) and severe in 23 (32.86%) patients. Nerve conduction studies were carried out in 48 (27 with and 21 without clinical neuropathy) patients, using the apparatus Dantec (Cantata TM). The nerves (median, peroneal and sural) were stimulated at two points and the recording of latency; amplitude (micro V) and motor and sensory nerve conduction velocities (m/s) were done under identical environmental conditions. Sensory nerve conduction velocity was more affected than motor velocity. In the 21 patients without clinical neuropathy, 14 showed abnormalities indicating early involvement of peripheral nerves. Reduction of motor nerve conduction velocity was more in patients with moderate and severe grades. The reduction was more in lower than in upper limbs. Nerve conduction abnormality helps in diagnosis in diabetic neuropathy even in preclinical state and correlates with severity, in clinical neuropathy.KEY WORDS: Diabetic neuropathy, Nerve conduction abnormality, Peripheral neuropathy 相似文献
27.
Dilip Rout Soumitra Mondal Indranil Chakraborty Malay Pramanik Syed Sirajul Islam 《Medicinal chemistry research》2004,13(6-7):509-517
The water-soluble glucan was obtained from Pleurotus florida fruit bodies by hot water extraction, ethanol precipitation, DEAE cellulose dialysis and Sephadex G-75 gel filtration. The
structural information of the glucan was achieved by chemical (hydrolysis, methylation, periodate oxidation) and spectroscopic
(1H and 13C) analyses, indicated a repeating unit built up of (1→6)-linked D-glucose. The following structure has been determined for
the repeating unit: →6)-α-D-Glcp-(1→ This fraction exhibited significant macrophage activity through the release of nitric
oxide 相似文献
28.
Ethnopharmacological relevance
Cassia sophera Linn (Family Caesalpiniaceae), popularly known as kasundi, is used both in the Indian traditional system and folk medicine to treat several inflammatory pathologies such as asthma, arthritis and pains. The aim of the present study was to evaluate the scientific basis of anti-inflammatory activity of Cassia sophera ethanol extracts and of an isolated constituent of Cassia sophera.Materials and methods
The anti-inflammatory activity of Cassia sophera was studied using the carrageenan, dextran induced rat paw edema, and cotton pellet induced granuloma in rats. The ethanol extract was administered at the concentrations of 200 and 400 mg/kg body weight whereas rhamnetin (RN) was administered at a dose of 10 and 15 mg/kg, b.w. Indomethacin was used as standard drug.Results
The HPLC analysis revealed that good amounts of rhamnetin (0.18%) was present in Cassia sophera.The ethanol extracts at 400 mg/kg, showed maximum inhibition of inflammation induced by carrageenan (44%), dextran (40%), cotton pellets (37.47%). On the other hand rhamnetin (15 mg/kg) exhibited maximum anti-inflammatory effect, that is 79 and 33% at the end of 3 h with carrageenin, and dextran-induced rat paw edema, respectively. In a chronic test rhamnetin (15 mg/kg) showed 43.32% reduction in granuloma weight.Conclusion
The marked inhibitory effect on paw edema and granuloma showed that Cassia sophera possess remarkable anti-inflammatory activity which may be due to rhamnetin at least in part, supporting the folkloric usage of the plant to treat various inflammatory diseases. 相似文献29.
Swagatha Ghosh Sayan Mondal Keerti Yadav Shantanu Aggarwal Wayne F. Schaefer Chandrabhas Narayana Ramaswamy Subramanian 《RSC advances》2022,12(31):20296
Biliverdin IX-alpha (BV), a tetrapyrrole, is found ubiquitously in most living organisms. It functions as a metabolite, pigment, and signaling compound. While BV is known to bind to diverse protein families such as heme-metabolizing enzymes and phytochromes, not many BV-bound lipocalins (ubiquitous, small lipid-binding proteins) have been studied. The molecular basis of binding and conformational selectivity of BV in lipocalins remains unexplained. Sandercyanin (SFP)–BV complex is a blue lipocalin protein present in the mucus of the Canadian walleye (Stizostedion vitreum). In this study, we present the structures and binding modes of BV to SFP. Using a combination of designed site-directed mutations, X-ray crystallography, UV/VIS, and resonance Raman spectroscopy, we have identified multiple conformations of BV that are stabilized in the binding pocket of SFP. In complex with the protein, these conformers generate varied spectroscopic signatures both in their absorption and fluorescence spectra. We show that despite no covalent anchor, structural heterogeneity of the chromophore is primarily driven by the D-ring pyrrole of BV. Our work shows how conformational promiscuity of BV is correlated to the rearrangement of amino acids in the protein matrix leading to modulation of spectral properties.Biliverdin IX-alpha undergoes rotation around the D-ring pyrrole and displays a broad far-red absorbance on binding to monomeric Sandercyanin variant (orange) compared to the wild-type tetrameric protein (cyan). 相似文献
30.
Rahul Ramesh Nair Moni Mohan Mondal Shanmugham Venkatachalam Srinivasan Dirk Weichgrebe 《Materials》2022,15(12)
Synthesizing biochar from mineral- and ash-rich waste biomass (MWB), a by-product of human activities in urban areas, can result in renewable and versatile multi-functional materials, which can also cater to the need of solid waste management. Hybridizing biochar with minerals, silicates, and metals is widely investigated to improve parent functionalities. MWB intrinsically possesses such foreign materials. The pyrolysis of such MWB is kinetically complex and requires detailed investigation. Using TGA-FTIR, this study investigates and compares the kinetics and decomposition mechanism during pyrolysis of three types of MWB: (i) mineral-rich banana peduncle (BP), (ii) ash-rich sewage sludge (SS), and (iii) mineral and ash-rich anaerobic digestate (AD). The results show that the pyrolysis of BP, SS, and AD is exothermic, catalyzed by its mineral content, with heat of pyrolysis 5480, 4066, and 1286 kJ/kg, respectively. The pyrolysis favors char formation kinetics mainly releasing CO2 and H2O. The secondary tar reactions initiate from ≈318 °C (BP), 481 °C (SS), and 376 °C (AD). Moreover, negative apparent activation energies are intrinsic to their kinetics after 313 °C (BP), 448 °C (SS), and 339 °C (AD). The results can support in tailoring and controlling sustainable biochar synthesis from slow pyrolysis of MWB. 相似文献