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排序方式: 共有1605条查询结果,搜索用时 31 毫秒
1.
Glauber T Silva Alejandro C Frery Mostafa Fatemi 《Computerized medical imaging and graphics》2006,30(5):321-327
We study the image formation of vibro-acoustography systems based on a concave sector array transducer taking into account depth-of-field effects. The system point-spread function (PSF) is defined in terms of the acoustic emission of a point-target in response to the dynamic radiation stress of ultrasound. The PSF on the focal plane and the axis of the transducer are presented. To extend the obtained PSF to the 3D-space, we assume it is a separable function in the axial direction and the focal plane of the transducer. In this model, an image is formed through the 3D convolution of the PSF with an object function. Experimental vibro-acoustography images of a breast phantom with lesion-like inclusions were compared with simulated images. Results show that the experimental images are in good agreement with the proposed model. 相似文献
2.
BACKGROUND: The 1997 National Asthma Education and Prevention Program (NAEPP) recommends a severity classification scheme to optimize the use of anti-inflammatory therapy for persistent asthma. Physician documentation of asthma severity is often used as a quality assurance measure. OBJECTIVE: To test the hypothesis that physician documentation of asthma severity is associated with appropriate use of anti-inflammatory therapy. DESIGN/METHODS: Setting: inner-city academic health center. First, we reviewed a consecutive sample of charts of scheduled pediatric patients. Then, we administered a structured parent survey regarding the child's asthma symptoms and current asthma therapy. We used NAEPP guidelines to classify patients' severity of asthma. The main outcome measure was appropriate use of anti-inflammatory therapy. Appropriate therapy was defined as: (1) mild persistent asthmatics using anti-inflammatory therapy, and (2) moderate-severe persistent asthmatics using inhaled steroids. Chart classification of asthma severity was compared with the NAEPP-applied classification. RESULTS: Of 784 charts, 214 (27%) were asthmatic. Of these, 176 (82%) were surveyed. The mean age was 7.4 years; 61% were males. Severity classification was documented in 77% of charts. Chart documentation differed significantly from survey classification for the same patients: (mild intermittent 54% vs. 40%, mild persistent 21% vs. 14%, moderate persistent 24% vs. 36%, severe persistent 1% vs. 10%; all p < .001). Correctly classified patients were more likely to be on appropriate therapy. CONCLUSIONS: Physicians underestimated the severity classification of asthmatic patients. Incorrect classification was associated with inappropriate asthma therapy. These findings have implications for the institution of asthma quality improvement programs. 相似文献
3.
Shunichi Takaya MD Shunzaburo Iwatsuki Takashi Noguchi Hisaaki Koie Iman Zaghloul Raman Venkataramanan Thomas E. Starzl 《Surgery today》1989,19(1):49-56
The influence of experimentally induced hepatic dysfunction on the pharmacokinetics of Cyclosporine A (CsA) was determined
in dogs. The pharmacokinetics of oral (PO) and intravenous (IV) CsA were studied before and after 70 per cent hepatectomy
or complete bile duct ligation (CBDL). Changes in liver function were monitored by serial measurements of serum bilirubin,
and by the maximum removal rate (Rmax) and plasma disappearance rate (ICG-K) of indocyanine green (ICG). Concentrations of
CsA in whole blood were measured by HPLC. Seventy per cent hepatectomy caused significant liver dysfunction: the ICG-Rmax
decreased by 47.7±7.1 per cent (mean±SD) and the ICG-K decreased by 61.3±9.7 per cent during the first week after hepatectomy.
At the same time, the systemic clearance (CLs) of IV-CsA decreased by 43.9±8.2 per cent, the area under the concentration
curve (AUC) of IV-CsA increased by 35.4±20.8 per cent and the bioavailability of CsA decreased by 26.4±14.8 per cent. CBDL
also induced significant liver dysfunction: the ICG-Rmax decreased by 39.1±12.8 per cent and the ICG-K decreased by 65.6±3.6
per cent in the second week after the operation. During the same period, the AUC of PO-CsA decreased by 69.9±10.7 per cent
and the bioavailability of CsA also decreased markedly by 73.9±15.6 per cent. These data indicate that hepatic impairment
significantly influences the pharmacokinetics of CsA, not only by the changes in intestinal absorption, but also by those
in hepatic, metabolism. Dose adjustment is therefore necessary in the presence of hepatic dysfunction in order to maintain
an adequate blood concentration of CsA without causing side effects.
This research was performed in the Department of Surgery, University of Pittsburgh Health Center, University of Pittsburgh,
USA 相似文献
4.
Kemal Yucesoy Iman Feiz-Erfan Robert F. Spetzler Patrick P. Han Stephen Coons 《Skull base》2004,14(3):169-173
A 42-year-old female presented with subarachnoid hemorrhage (SAH), presumably from a radiation-induced anterior communicating artery aneurysm. Six years earlier, she had undergone radiation treatment for an optic glioma that was diagnosed based on imaging criteria. The aneurysm was successfully clipped, and the optic glioma was biopsied to verify the diagnosis histologically. Radiation-induced cerebral aneurysms often manifest with a fatal SAH. These aneurysms typically develop in the field of radiation and are diagnosed a mean of 8.52 years after radiation. Rarely, the aneurysm sac thromboses spontaneously. Clipping or coiling of the aneurysm can be an effective treatment. 相似文献
5.
6.
Iman Al‐Saleh Andrew Taylor Richard Hinton 《International journal of environmental health research》1992,2(4):184-191
Erythrocyte protoporphyrin and blood lead concentrations were measured in samples from 583 Saudi children attending the outpatient clinics. Erythrocyte protoporphyrin concentrations showed poor correlation with blood lead concentrations of 25 ug dl?1 and below. Measurement of erythrocyte protoporphyrin as a primary test for lead exposure is not recommended. 相似文献
7.
Genome-scale reconstruction of the Saccharomyces cerevisiae metabolic network 总被引:9,自引:0,他引:9
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The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments and the environment were included. A total of 708 structural open reading frames (ORFs) were accounted for in the reconstructed network, corresponding to 1035 metabolic reactions. Further, 140 reactions were included on the basis of biochemical evidence resulting in a genome-scale reconstructed metabolic network containing 1175 metabolic reactions and 584 metabolites. The number of gene functions included in the reconstructed network corresponds to approximately 16% of all characterized ORFs in S. cerevisiae. Using the reconstructed network, the metabolic capabilities of S. cerevisiae were calculated and compared with Escherichia coli. The reconstructed metabolic network is the first comprehensive network for a eukaryotic organism, and it may be used as the basis for in silico analysis of phenotypic functions. 相似文献
8.
Osman MY Sharaf IA el-Rehim WM el-Sharkawi AM 《British journal of biomedical science》2002,59(4):212-217
Hard capsules are made of pure gelatin and small quantities of additives, including colouring agents permitted for use in food. In this study, the effects of three colouring agents (sunset yellow, quinoline yellow and erythrosine) on true and pseudo-cholinesterases (ChE) are assessed in erythrocytes and plasma, respectively. Results indicated that the synthetic compounds affected both true and pseudo ChE activity. The concentration of sunset yellow which caused 50% inhibition (IC50) of true ChE was about 64% that of pseudo-ChE; for erythrosine, IC50 was approximately the same for both true and pseudo-ChE; and for quinoline yellow, IC50 for true ChE was 25% of pseudo-ChE, although its effect on both true and pseudo-ChE was greater than seen with the other two dyes. Inhibitions of both true and pseudo-ChE were of mixed type (competitive and non-competitive). The enzyme-inhibitor dissociation constant (Ki) indicated that quinoline yellow was most potent and erythrosine was least potent out of the three compounds. Inhibition of both true and pseudo-ChE by each of the three dyes was abolished by dialysis, indicating that the effects were reversible. 相似文献
9.
Iman A. Nuwayhid 《American journal of public health》2005,95(4):550-551
10.
Is Fatimah Sugesti Nur Amaliah Muhammad Fiqri Andrian Tri Pindi Handayani Rico Nurillahi Nurcahyo Iman Prakoso Wiyogo Prio Wicaksono Laemthong Chuenchom 《Sustainable Chemistry and Pharmacy》2019
This research demonstrates the use of biogenic silica derived from bamboo leaf ash as a support for iron oxide nanoparticles. The preparation includes silica extraction from bamboo leaf ash and iron oxide nanoparticle impregnation into the silica gel under hydrothermal conditions, which is followed by calcination at 400 °C for 2 h. The physicochemical characterization includes X-ray diffraction analysis, gas sorption analysis, scanning electron microscopic analysis and transmission electron microscopic analysis. The light absorption capability and the band gap energy of the materials were determined by diffuse-reflectance UV–visible spectrophotometry. The materials obtained by varying the Fe content to 5 and 10% wt. were evaluated in rhodamine B photocatalytic degradation and photooxidation systems. It was found that the materials have a combined hematite and magnetite nanostructure, with the ratio of 9:10, and the particle sizes range from 10 to 40 nm. With a band gap energy of 2.27 eV, the prepared materials produce the successive photocatalytic degradation of rhodamine B. It was clarified that the formation of composite enhances stability and reusability of photocatalyst as shown by the stable initial rate at wide pH range and reuse for 5 cycles. Degradation mechanism is enhanced by the addition of H2O2 as an oxidant, and the investigation of the effect of scavengers shows that the degradation rate not only depends on radical formation but also on other species related to the formation of oxidizing agent. 相似文献