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排序方式: 共有988条查询结果,搜索用时 15 毫秒
71.
MB Melo FF Costa ST Saad I Lorand-Metze S Bordin NN Ahmad 《Canadian Metallurgical Quarterly》1998,22(9):787-792
Patient 1: A 48-year-old man was admitted to Osaka Red Cross Hospital because of fever and dyspnea. Laboratory examination revealed pancytopenia, liver dysfunction and hematostatic abnormality. Chest radiographs obtained on admission revealed ground-glass opacity in both lung fields, and an analysis of arterial blood showed severe hypoxemia (PaO2:46.8 Torr). Pulse therapy with methylprednisolone was started. Although the hypoxemia subsided and radiographic findings rapidly improved, pancytopenia persisted. Examination of bone marrow aspirate revealed mature histiocytes with marked hemophagocytosis. Amplified Mycobacterium tuberculosis direct tests of bronchoalveolar lavage fluid, sputum, urine, and bone marrow were all positive, and Mycobacterium tuberculosis was cultured from sputum and urine. Although the patient was taking antituberculous agents, his pancytopenia persosted. Treatment with etoposide induced remssion. Patient 2: A 19-year-old woman was admitted to Osaka Red Cross Hospital because of prolonged cough and fever. Laboratory examination revealed leukocytosis, liver dysfunction, and hematostatic abnormality. Serologic tests provided conclusive evidence of Mycoplasma infection and a CRP test was strongly positive. Chest radiographs obtained on admission revealed infiltration shadows in the middle and lower lung fields on both sides, with left pleural effusion. An analysis of arterial blood showed hypoxemia (PaO2: 54.2 Torr). Examination of bone marrow and pleural effusion samples revealed mature histiocytes with marked hemophagocytosis. Although treatment with antibiotics and pulse therapy with methylprednisolone was started, the patients respiratory functions deteriorated. Endotracheal intubation was performed. Therapy with etoposide induced remission. Hemophagocytic syndrome associated with Mycoplasma infection and tuberculosis appears to be exceedingly rare. In these 2 cases, it was difficult to achieve remission with therapy for the underlying infections, but etoposide treatment was effective. 相似文献
72.
To determine the minimal contrast dosage required for diagnostic contrast-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) image quality of the pulmonary (PAs) or renal arteries (RAs). In 12 volunteers (10 females, 2 males; mean age 24 years) imaging was performed with 4 different dosages: 0.05, 0.1, 0.2 and 0.3 mmol/kg of body weight (BW) 0.5 M gadolinium (Gd) contrast agent. The PAs and RAs were evaluated separately each in groups of six volunteers. Qualitative and quantitative signal-to-noise ratio (SNR) image analysis was performed. For the PAs, the increases in signal-to-noise ratio were paralleled by increases in image quality ratings. For the PAs, with the use of 0.05 mmol/kg, only 50.3% of all segments were rated diagnostic, whereas with higher dosages the percentage rose to 89.2% for 0.1 mmol/kg, 98.2% for 0.2 mmol/kg. and 99.1% for 0.3 mmol/kg. For the RAs, 0.3 mmol/kg provided no significant increase in singal-to-noise ratio compared to 0.2 mmol/kg (p = 0.4). Only by a dosage of 0.2 and 0.3 mmol/kg, all evaluated segments were diagnostic evaluable. A dose of 0.2 mmol/kg is required for proper assessment of the RAs or PAs. 相似文献
73.
Carbonyl compound. react with 2, 4-dinitrophtnylhydrazin. to form the corresponding hydrsiones. These hydrazones in the prrsence of lN NaOH give a reddish brown color which can be utilized for colorimatric analysis. This method is used for the spectrophoto-metric determination of quinolinium-6-carboxy-l-metliyl- iodide. Furthermota 2. 4-dinitrophenylhydrazine is utilized to kinetic measurements of the rate of hydrolysie of the quinolinium acid esters. 相似文献
74.
Minas cheese is a typical Brazilian fresh cheese, manufactured by addition of rennin and CaCl2 to milk, followed by draining the curd. The intrinsic characteristics of this product make it favorable for growth of pathogens, including Escherichia coli O157:H7. The influence of the addition of a commercial mesophilic type O lactic culture to this product on the growth of this pathogen during storage at 8.5 degrees C was evaluated. Eight different formulations of Minas cheese were manufactured using raw or pasteurized milk and with or without salt and lactic culture. Individual portions of each formulation were transferred to sterile plastic bags and inoculated with E. coli O157:H7 to yield ca. 10(3) or 10(6) CFU/g. After blending by hand massaging the bags, samples were stored at 8.5 degrees C for up to 14 days. E. coli O157:H7 was counted after 1, 2, 7, and 14 days of storage using 3M Petrifilm Test Kit-HEC. Counts in samples without added lactic culture showed a 2-log increase in the first 24 h and remained constant during the following 14 days. Counts in samples with added lactic culture showed a 0.5-log increase in the first 24 h, followed by a decrease. These variations were statistically significant (P < 0.05). No significant variations (P > 0.05) were obtained for cheese samples manufactured with pasteurized or raw milk, with or without salt. Results indicate that the addition of type O lactic culture may be an additional safeguard to well-established good manufacturing practices and hazard analysis and critical control point programs in the control of growth of E. coli O157:H7 in Minas cheese. 相似文献
75.
Cuiling Li Bo Jiang Hungru Chen Masataka Imura Liwen Sang Victor Malgras Yoshio Bando Tansir Ahamad Saad M. Alshehri Satoshi Tominaka Yusuke Yamauchi 《Nano Research》2016,9(6):1752-1762
Mesoporous Au films consisting of a network of interconnected Au ligaments around ultra-large pores were found to exhibit a promising electrocatalytic activity towards sluggish reactions. Mesoporous Au films with pore sizes up to 25 nm were successfully fabricated using a polymeric micelle approach. A superior catalytic activity of the mesoporous Au films towards methanol oxidation was confirmed, which was thoroughly analyzed and compared with that of other Au materials. An intrinsic investigation on the high catalytic activity revealed that the superior performance of the as-prepared mesoporous Au film was related to its unique atomic structures around the mesopores with well-crystallized facets and several step/kink sites on the Au surfaces. These findings showcase a strategic and feasible design for preparing highly active Au-based catalysts that could be used as promising candidates in electrocatalytic applications. 相似文献
76.
In this paper the theoretical basis is presented and the implementation of a term rewriting system based on algebraic specifications is described. The input to this system is represented by an algebraic specification language, which forms not only the set of axioms but also the sorts, variables, operators and terms of a specific simulated theory or application. Rewriting and matching mechanisms provide the formal methodology for evaluating terms and proving assertions in an algebraic theory. Specifications are evaluated by interpreting terms by means of rewrite rules. The rules are described by the axioms of the specifications where the finite termination and congruence properties are assumed. A term rewriting system to recognize handwritten Hindu numerals is introduced as a case study. Besides rewriting, a robust algorithm is proposed to segment the numeral's image into strokes based on feature points and to identify cavity features. A syntactic representation (term) of the input image is matched and rewritten against a set of rules. Experimental results proved that the proposed system is tolerant to recognize a variety of numeral shapes with 96% successful recognition rate. 相似文献
77.
In this paper a control problem of leader–follower motion coordination of multiple nonholonomic mobile robots is addressed and subsequently in the proposed scheme, a reference trajectory generated based on the information from the leader is tracked by the follower robots. To alleviate demanded information on the leader, specifically to eliminate the measurement requirement or estimation of the leader's velocity and dynamics, a virtual vehicle is constructed whereby its trajectory converges to the reference trajectory of the follower. Trajectory tracking controller is then designed to allow the follower robot to track the virtual vehicle using neural network approximation, in combination with the backstepping and Lyapunov direct design technique and finally the performance and effectiveness of the controller is verified throughout the experiments. 相似文献
78.
In this paper, we investigate new implementable cooperative adaptive backstepping controllers for a group of underactuated autonomous vehicles that are communicating with their local neighbours to track a time-varying virtual leader of which the relative position may only be available to a portion of the team members. At the kinematic cooperative control level of the autonomous underwater vehicle, the virtual cooperative controller is basically designed on a proportional and derivative consensus algorithm presented in Ren (2010), which involves velocity information from local neighbours. In this paper, we propose a new design algorithm based on singular perturbation theory that precludes the use of the neighbours’ velocity information in the cooperative design. At the dynamic cooperative control level, calculation of the partial derivatives of some stabilising functions which in turn will contain velocity information from the local neighbours is required. To facilitate the implementation of the cooperative controllers, we propose a command filter approach technique to avoid analytic differentiation of the virtual cooperative control laws. We show how Lyapunov-based techniques and graph theory can be combined together to yield a robust cooperative controller where the uncertain dynamics of the cooperating vehicles and the constraints on the communication topology which contains a directed spanning tree are explicitly taken into account. Simulation results with a dynamic model of underactuated autonomous underwater vehicles moving on the horizontal plane are presented and discussed. 相似文献
79.
The rapid scaling of integrated circuit requires further shrinkage of lateral device dimension, which correlates with pillar thickness in vertical structure. This paper investigates the effect of pillar thickness variation on vertical double gate MOSFET (VDGM) fabricated using oblique rotating ion implantation (ORI) method. For this purpose, several scenarios of silicon pillar thickness tsi were evaluated for 20–100 nm channel length. The source region was found to merge at pillar thickness below 75 nm, which results in floating body effect and creates isolated region in the middle of pillar. The vertical devices using ORI method show better performance than those with conventional implantation method for all pillar thickness, due to the elimination of corner effect that degrades the gate control. The presence of isolated depletion region in the middle of pillar at floating body increases parasitic effect for higher drain potential. By further reduction of pillar thickness towards fully depleted feature, the increase in gate-to gate charge coupling improves the performance of ORI-based vertical double gate MOSFET, as evident in near-ideal swing value and lower DIBL, compared to the partially depleted and body-tied device. 相似文献
80.