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1.
人体肥大细胞的多态性已受到广泛关注,对于肥大细胞分型的研究已成为这一问题的关键。本实验研究了42例人大肠4种肥大细胞类群光镜特征,其中两种为作者的新近发现,暂命名为结缔组织肥大细胞-1(CTMC-1)和粘膜肥大细胞-1(MMC-1)。  相似文献   
2.
Abstract: The resolution of several structurally related synthetic peptides, derived from the loop 3 region of the activin βA–βD subunits, has been studied using capillary electrochromatography (CEC) with Hypersil n‐octadecylsilica as the sorbent. The results confirm that the CEC migration of these peptides can be varied in a charge‐state‐specific manner as the properties of the background electrolyte, such as pH, salt concentration and content of organic modifier, or temperature are systematically changed. Acidic peptides followed similar trends in retention behaviour, which was distinctly different to that shown by more basic peptides. The CEC separation of these peptides with the Hypersil n‐octadecyl‐silica involved distinguishable contributions from both electrophoretic mobility and chromatographic retention. Temperature effects were reflected as variations in both the electro‐osmotic flow and the electrophoretic mobility of the peptides. When the separation forces acting on the peptides were synergistic with the electro‐osmotic flow, as, for example, with the positively charged peptides at a particular pH and buffer electrolyte composition, their retention coefficient, κcec, decreased with increasing capillary temperature, whereas when the separation forces worked in opposite directions, as for example with negatively charged peptides, their κcec values increased slightly with increasing temperature. Moreover, when the content of organic modifier, acetonitrile, was sufficiently high, e.g. > 40% (v/v) and nonpolar interactions with the Hypersil n‐octadecyl‐silica sorbent were suppressed, mixtures of both the basic and acidic synthetic peptides could be baseline resolved under isocratic conditions by exploiting the mutual processes of electrophoretic mobility and electrostatic interaction. A linear relationship between the ln κcec values and the volume fractions, ψ, of the organic modifier over a limited range of ψ‐values, was established for the negatively charged peptides under these isocratic conditions. These findings thus provide useful guidelines in a more general context for the resolution and analysis of structurally related synthetic peptides using CEC methods.  相似文献   
3.
ObjectivesThe aim of this study was to assess the safety and effectiveness of directional atherectomy (DA) for endovascular treatment of peripheral arterial disease (PAD) in infrainguinal arteries in patients with claudication or critical limb ischemia.BackgroundTo date, no prospective, multicenter, independently-adjudicated study has evaluated the effectiveness and durability of DA in the treatment of PAD. Previous DA studies have not been prospectively powered to evaluate any differences in outcomes in patients with and without diabetes.MethodsDEFINITIVE LE (Determination of EFfectiveness of the SilverHawk® PerIpheral Plaque ExcisioN System (SIlverHawk Device) for the Treatment of Infrainguinal VEssels / Lower Extremities) prospectively enrolled subjects at 47 multinational centers with an infrainguinal lesion length up to 20 cm. Primary endpoints were defined as primary patency at 12 months for claudicants and freedom from major unplanned amputation for critical limb ischemia (CLI) subjects. A pre-specified statistical hypothesis evaluated noninferiority of primary patency in diabetic versus nondiabetic claudicants. Independent angiographic and sonographic core laboratories assessed outcomes, and events were adjudicated by a clinical events committee.ResultsA total of 800 subjects were enrolled. The 12-month primary patency was 78% (95% confidence interval: 74.0% to 80.6%) in claudicants, with a 77% rate in the diabetic subgroup versus 78% in the nondiabetic subgroup (noninferior, p < 0.001). The rate of freedom from major unplanned amputation of the target limb at 12 months in CLI subjects was 95% (95% confidence interval: 90.7% to 97.4%). Periprocedural adverse events included embolization (3.8%), perforation (5.3%), and abrupt closure (2.0%). The bail-out stent rate was 3.2%.ConclusionsThe DEFINITIVE LE study demonstrated that DA is a safe and effective treatment modality at 12 months for a diverse patient population with either claudication or CLI. Furthermore, DA was shown to be noninferior for treating PAD in patients with diabetes compared with those without diabetes. (Study of SilverHawk/TurboHawk in Lower Extremity Vessels [DEFINITIVE LE]; NCT00883246).  相似文献   
4.
Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has aroused that increasing plant growth is caused by a long-lasting improvement of soil physicochemical properties by zeolites. In the first year of our field experiment performed on a poor soil with zeolite rates from 1 to 8 t/ha and N fertilization, an increase in spring wheat yield was observed. Any effect on soil cation exchange capacity (CEC), surface area (S), pH-dependent surface charge (Qv), mesoporosity, water holding capacity and plant available water (PAW) was noted. This positive effect of zeolite on plants could be due to extra nutrients supplied by the mineral (primarily potassium—1 ton of the studied zeolite contained around 15 kg of exchangeable potassium). In the second year of the experiment (NPK treatment on previously zeolitized soil), the zeolite presence did not impact plant yield. No long-term effect of the zeolite on plants was observed in the third year after soil zeolitization, when, as in the first year, only N fertilization was applied. That there were no significant changes in the above-mentioned physicochemical properties of the field soil after the addition of zeolite was most likely due to high dilution of the mineral in the soil (8 t/ha zeolite is only ~0.35% of the soil mass in the root zone). To determine how much zeolite is needed to improve soil physicochemical properties, much higher zeolite rates than those applied in the field were studied in the laboratory. The latter studies showed that CEC and S increased proportionally to the zeolite percentage in the soil. The Qv of the zeolite was lower than that of the soil, so a decrease in soil variable charge was observed due to zeolite addition. Surprisingly, a slight increase in PAW, even at the largest zeolite dose (from 9.5% for the control soil to 13% for a mixture of 40 g zeolite and 100 g soil), was observed. It resulted from small alterations of the soil macrostructure: although the input of small zeolite pores was seen in pore size distributions, the larger pores responsible for the storage of PAW were almost not affected by the zeolite addition.  相似文献   
5.

Purpose

To prospectively assess the Sentry bioconvertible inferior vena cava (IVC) filter in patients requiring temporary protection against pulmonary embolism (PE).

Materials and Methods

At 23 sites, 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, unable to use anticoagulation were enrolled. The primary end point was clinical success, including successful filter deployment, freedom from new symptomatic PE through 60 days before filter bioconversion, and 6-month freedom from filter-related complications. Patients were monitored by means of radiography, computerized tomography (CT), and CT venography to assess filtering configuration through 60 days, filter bioconversion, and incidence of PE and filter-related complications through 12 months.

Results

Clinical success was achieved in 111 of 114 evaluable patients (97.4%, 95% confidence interval [CI] 92.5%–99.1%). The rate of freedom from new symptomatic PE through 60 days was 100% (n = 129, 95% CI 97.1%–100.0%), and there were no cases of PE through 12 months for either therapeutic or prophylactic indications. Two patients (1.6%) developed symptomatic caval thrombosis during the first month; neither experienced recurrence after successful interventions. There was no filter tilting, migration, embolization, fracture, or caval perforation by the filter, and no filter-related death through 12 months. Filter bioconversion was successful for 95.7% (110/115) at 6 months and for 96.4% (106/110) at 12 months.

Conclusions

The Sentry IVC filter provided safe and effective protection against PE, with a high rate of intended bioconversion and a low rate of device-related complications, through 12 months of imaging-intense follow-up.  相似文献   
6.
检测39例肺炎及合并呼衰或MSOF患儿血清TNFa及CEC数,血糖及乳酸,结合临床监护,结果发现TNFa及CEC数,呼衰组明显高于肺炎组(P<0.01),而MSOF组明显高于呼衰组(P<0,01)。提示肺炎时TNFa可能是其恶化的始动因素,而血管内皮损伤是其关键环节;TNFa及CEC数与危重度评分高低,疾病轻重,脏器功能不全程度密切相关。因此在预测肺炎发生呼衰时除PaO2及PaCO2,TNFa及CEC数或许是另一重要数据。  相似文献   
7.
The state-of-the-art in CEC enantiomer separations with monolithic capillary columns is comprehensively reviewed. The various types of monolithic columns comprising in situ organic polymer monoliths, molecularly imprinted polymer (MIP) monoliths, silica monoliths and monoliths made from particles are discussed with a focus on materials’ synthesis, chemistry and properties as well as column aspects. Monolithic MIP-type porous layer open-tubular (PLOT) columns are treated herein as well. From this survey of the literature, the authors come to the conclusion that monolithic silica capillaries appear to become the preferred column type for CEC enantiomer separations of low-molecular drugs and other chiral pharmaceuticals or chemicals.  相似文献   
8.
毛细管电色谱是近年来发展起来的微分离技术,在环境分析、医药生化等方面有特殊应用。文章综述了毛细管电色谱的进展以及柱子类型和制柱相关技术、概括了它的应用范围.展望了它的发展趋势。  相似文献   
9.
研究结果表明,粤西砖红壤的全镁含量普遍较低,玄武岩和花岗岩发育的土壤,全镁含量多在0.2%以下,浅海沉积物发育的土壤,全镁不足0.1%,玄武岩发育的土壤,交换性镁较丰,表土含量均在100ppm以上,镁饱和度较高;浅海沉积物和花岗岩发育的土壤,交换性镁贫缺,表土平均含量分别为16.7和14.7ppm,镁饱和度大都极低.土壤供镁能力的强弱依次是:玄武岩发育的砖红壤>浅海沉积物发育的砖红壤>花岗岩发育的砖红壤。交换性镁及镁饱和度与牧草的相对产量、吸镁量以及玉米小苗的含镁量、吸镁量的相关性达显著或极显著水平。据此初步认为可用作土壤镁素诊断指标。酸深性镁的有效性也较高,但因其释放速度较慢,不宜作为诊断指标,可用以评价土壤有效镁的补充能力。  相似文献   
10.
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