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目的 了解石家庄市学前儿童睡眠问题的流行情况及相关因素。方法 采用儿童睡眠习惯问卷(The Children's Sleep Habit Questionnaire, CSHQ)和自编问卷对石家庄市区6所幼儿园445名儿童进行测查。结果 石家庄市学龄儿童睡眠问题流行率总体为76.3%, 各类睡眠问题的流行率分布于12.1%(睡眠呼吸障碍)至67.6%(睡眠阻抗)之间。高年级、父母文化程度高、居住面积充足、单独睡眠、养育观念一致的儿童的CSHQ得分较低(P<0.01或<0.05)。与国外群体相比, 此次调查对象的CSHQ得分较高(P<0.01或<0.05)。结论 石家庄市学前儿童睡眠问题较严重、不同睡眠障碍类型流行率变化较大;睡眠问题与年级、父母文化程度、睡眠环境、家庭养育等因素有关。  相似文献   
243.
A novel controlled drug release system based on pH sensitive polyacrylonitrile (PAN) nanoflowers in different kinds of solvents was successfully prepared with azobisisobutyronitrile (AIBN) as the initiator and without any emulsifier or stabilizer by a one step static polymerization method. The composition and structure of the PAN nanoflowers were analyzed by FTIR, XRD, SEM, TEM, and laser particle size analysis. The polymer particles consisted of a number of lamellae, with a sheet thickness of about 10 nm, and were similar to the shape of flowers with a particle diameter of about 350 nm. The mechanism of the polymerization reaction and the formation were studied. Moreover, the effects of monomer ratio, initiator concentration, reaction time, dispersion medium and co-monomer on the morphology and particle size of the nanoflowers were also discussed. A relatively large specific surface area was formed during the formation of the nanoflowers, which favored drug adsorption. The results of the in vitro experiments revealed that PAN(TBP) nanoflowers, containing BSA in buffer solution of pH 7.4, demonstrated good sustained-release and the cumulative release rate was about 83% after 260 h. The results also showed that the sustained-release from the PAN(TBP) nanoflowers best fitted the Riger-Peppas model. This study indicated that PAN(TBP) nanoflowers provided a theoretical base for the development of carriers for sustainable drug-release.

The schematic preparation of a new kind of pH-sensitive PAN nanoflower and its potential application for UC therapy. PAN (TBP) nanoflowers at pH 7.4 showed good sustained-release (t83% = 260 h), which best fitted the Riger–Peppas model.  相似文献   
244.
Polarization holography has the unique capacity to record and retrieve the amplitude, phase, and polarization of light simultaneously in a polarization-sensitive recording material and has attracted widespread attention. Polarization holography is a noteworthy technology with potential applications in the fields of high-capacity data storage, polarization-controlled optical elements, and other related fields. The choice of its high-performance materials is particularly important. To further develop polarization holography applications and improve the quality of the information recorded (i.e., material sensitivity and resolution), a deeper understanding of such materials is needed. We present an overview of the polarization-sensitive materials, which introduced polarization holographic technology and the development of polarization holographic materials. The three main types of polarization holographic materials are described, including azopolymer materials, photopolymer material, and photorefractive polymer material. We examine the key contributions of each work and present many of the suggestions that have been made to improve the different polarization-sensitive photopolymer materials.  相似文献   
245.
In this work, Bi2Ga4−xFexO9 (0 ≤ x ≤ 1.2) solid solutions were prepared via the traditional high-temperature solid-state reaction. The Le Bail fitting on the powder X-ray diffraction patterns shows that these solid solutions were successfully synthesized. Scanning electron microscopy showed that the Bi2Ga3.2Fe0.8O9 sample was composed of sub-micron particle crystallites. Energy dispersive spectroscopy analysis and X-ray photoelectron spectroscopy were used to identify that the Fe element is trivalent when doping into the crystal structure. Ultraviolet-visible diffused reflectance spectra suggested that the bandgap of Bi2Ga3.2Fe0.8O9 is narrower than that of the undoped Bi2Ga4O9 sample. Three strategies, including Fe3+ doping, addition of H2O2, and loading of the cocatalyst, were utilized to improve the photocatalytic degradation activity. The optimum photocatalytic performance was obtained over 2.5 wt% Cu/Bi2Ga3.2Fe0.8O9 sample in 20 ppm RhB aqueous solution (containing 1.5 mL H2O2) under visible light irradiation. Its photodegradation rate is 8.0 times that of Bi2Ga4O9 containing 0.5 mL H2O2. The 2.5 wt% Cu/Bi2Ga3.2Fe0.8O9 photocatalyst remained stable and active even after four cycles. Also, its photocatalytic conversion efficiency for RhB was nearly 100%, which was achieved in 3 hours. The photocatalytic mechanism indicated that ·OH and h+ played an important role in the photocatalytic degradation reaction.

In this work, Bi2Ga4−xFexO9 (0 ≤ x ≤ 1.2) solid solutions were prepared via the traditional high-temperature solid-state reaction.  相似文献   
246.
《Artery Research》2014,8(3):88-97
BackgroundWe explored the relationship between QRS characteristics and myocardial phenotype by delayed-enhancement cardiac magnetic resonance (DE-CMR) in patients with coronary heart disease (CHD).Methods and resultsEighty five consecutive patients with CHD that were referred for DE-CMR evaluation constituted the study population. Of a total of 1445 left ventricular (LV) segments evaluated, 346 (23.9%) segments had fibrosis.Compared to patients without pathological Q waves, patients with pathological Q waves showed a higher number of segments with fibrosis (5.9 ± 3.1 vs. 2.7 ± 2.8, p < 0.001), and lower left ventricular ejection fraction (LVEF) (42.9 ± 13.6% vs. 51.8 ± 18.3, p = 0.01); whereas no significant differences were observed regarding LV size.When discriminated in according to the QRS duration tertiles, no significant differences were observed regarding the number of segments with fibrosis (p = 0.34), whereas the highest QRS tertile was related to the presence of a low LVEF (p = 0.005) and larger LV size (p = 0.01). QRS fragmentation (fQRS), defined as the presence of an R′ or notching in the nadir of the R wave or the S wave, or the presence of >1 R′ in 2 contiguous leads, was significantly related to LV size (LV end diastolic volume 153.6 ± 81.6 ml, vs. 111.5 ± 41.4 ml, p = 0.003), function (LVEF 43.2 ± 15.9% vs. 53.6 ± 16.3%, p = 0.005), and extent of fibrosis (5.1 ± 3.4 segments vs. 3.2 ± 3.1 segments, p = 0.01).ConclusionsIn the present study, fQRS was the only QRS-derived variable systematically and more closely related to LV size, LV systolic function, and to the presence and extent of fibrosis.  相似文献   
247.
248.
AIM: To investigate the inhibitory effect of the combined use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and oridonin on choroidal melanoma cell lines, and to explore its underlying mechanism. METHODS: MUM-2B and C918 cells were treated with different concentrations of TRAIL and oridonin, and MTT assay used to evaluate the inhibition rate of the two compounds on cells. Then, the cell cycle distribution and apoptosis were detected by flow cytometry, and changes in apoptosis-related proteins such as death receptor 5 (DR5), a-caspase-3, and x-linked inhibitor of apoptosis protein (XIAP) were detected by Western blot. MUM-2B cells were transfected with si-DR5, which interfered with the expression of the DR5 gene. MTT and Western blot assay were used to detect cell activity and apoptosis-related proteins. RESULTS: When TRAIL and oridonin were simultaneously administered to the MUM-2B cells, the apoptosis rate was significantly higher than that by the two drugs individually. However, the effect of combined use of TRAIL and oridonin on C918 cells was not significantly different from that used alone. Cell cycle analysis showed that TRAIL and oridonin could induce G2/M arrest in MUM-2B cells. The Western blot results showed that the protein expression levels of the DR5, a-caspase-3, and BAX increased, while the expression levels of the anti-apoptosis-related proteins XIAP and BCL-2 were suppressed when TRAIL and oridonin simultaneously administered to MUM-2B cells. Interfering the expression of DR5 gene in MUM-2B cells could reverse the inhibitory effect of oridonin and TRAIL on the proliferation and apoptosis induction of MUM-2B cells. CONCLUSION: The inhibitory effects of oridonin and TRAIL on MUM-2B cells are significantly enhanced when they were administered as a combined treatment, which may ascribe to up-regulation of DR5.  相似文献   
249.
We have synthesized a renal-specific drug carrier, 14-succinyl triptolide-lysozyme (TPS-LZM) conjugate for targeted delivery of TP to the PTECs. TPS-LZM could be taken up by HK-2 cells, free TP would be degraded and released, mainly from basolateral side of the cells. Compared with TP, the overall targeting efficiency (TE) of TPS-LZM was significantly enhanced from 11.74% to 95.54% and its MRT was moderately prolonged from 3.08 h to 4.10 h. At very low concentration, TPS-LZM could significantly reverse the disease progression in renal ischemia-reperfusion (I/R) injury animal models, while the mixture of free TP and LZM was ineffective. Further, TPS-LZM conjugate presented much lower hepatotoxicity (0.78 folds lower than TP) and no adverse effect on the immune (1.13 folds higher than TP) and genital system. Thus, TPS-LZM represents a very effective drug candidate for specific treatment of immunological renal diseases with low adverse side effect.  相似文献   
250.
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