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Metallurgical and Materials Transactions A - In this work, the effects of Te doping on the microstructure and thermoelectric properties of the partially filled skutterudite La0.5Co4Sb12 compounds...  相似文献   
53.
Abnormal brain stem auditory-evoked responses (BAER) were recorded on 14 dogs with brain lesions confirmed by necropsy (n = 13) or magnetic resonance imaging and surgical biopsy (n = 1). Lesions included brain stem or cerebellar tumors (6 dogs), brain stem trauma (1 dog), forebrain tumors (3 dogs), hydrocephalus (2 dogs), granulomatous meningoencephalitis (1 dog), and meningoencephalitis (1 dog). Five affected dogs were comatose at the time of recording. BAER abnormalities could be classified as (1) absence of some or all of waves I to V, (2) increased latencies, with wave V being most frequently affected, or (3) a reduction in the amplitude ratio of waves V/I.  相似文献   
54.
We have previously shown that replication in vitro of plasmids containing the Simian virus 40 (SV40) origin of replication is reduced when an extract of irradiated cells is used (Wang et al., Radiat. Res. 142, 169-175, 1995). We proposed that the observed reduction in the overall replication activity is due to a reduction in the efficiency of initiation events, and that it is caused by the induction or activation by ionizing radiation of a factor(s) that inhibits DNA replication in trans. Here, we extend these studies and provide evidence that the reduced replication activity of an extract prepared from irradiated cells is not the result of a nonspecific inactivation of proteins or of an increase in the requirement for SV40 large tumor antigen (TAg), the only noncellular protein required for in vitro DNA replication. Mixing experiments demonstrate the presence of a dominant inhibitory activity(ies) in the extract of irradiated cells that efficiently stalls replication in reactions assembled using extract of nonirradiated cells. The inhibitory activity is a stable, nondialyzable molecule. Studies of kinetics suggest that the inhibitory activity(ies) affects the initiation steps of DNA replication and acts, at least partly, by modifying TAg, the key initiation protein of SV40 ori DNA replication. It is likely that the same inhibitory activity(ies) regulates cellular DNA replication by modifying the cellular homologues of TAg. Purification and characterization of this inhibitory activity(ies) will contribute to our understanding of the mechanism developed by the cell to regulate DNA replication after exposure to ionizing radiation and will define a checkpoint operating in S phase. Genetic evidence for a checkpoint in S phase distinct from the checkpoints operating in G1 and G2 phase has been reported in yeast.  相似文献   
55.
Optic fluidic devices, which combine optical elements such as adaptive optical lenses or diffraction gratings into micro-fluidic devices, are now becoming increasingly important for environmental monitoring, medical diagnostics and chemical detection. In this paper, we present a novel and simple micro/nanofabrication process for SU-8 based optic fluidics structures with phase gratings on the bottom of the micro-channel using our silicon grating templates. The refraction index difference between the fluid and the SU-8 gratings generates a modulation in the phase of the light passing through the device. Our method of fabricating optic fluidic device is promising to be economic in fabrication, high throughput in production and have potential applications for sensing.  相似文献   
56.
    
Abstract: This paper presents a novel intelligent sensory information processing technique using a fuzzy discrete event system (FDES) for robotic control. The proposed method combines the predictive control approach of a discrete event system with the approximate reasoning aspect of fuzzy logic. It develops a supervisory control strategy for behavior-based robotic control using distributed FDES. The application of distributed FDES eliminates the formation of complex fuzzy predicates and a large fuzzy rule-base. The FDES-based approach also provides means for analyzing behavior-based decision-making using the observability and controllability of an FDES. The observability of an FDES describes uncertainties in sensory data, and the controllability of an FDES exploits uncertain state transitions in a dynamic environment. Comprehensive experiments on behavior-based mobile robot navigation are presented to authenticate the performance of the proposed methodology.  相似文献   
57.
In order to evaluate the potential clinical and economic benefits of granulocyte colony-stimulating factor (G-CSF, filgrastim) following peripheral blood progenitor cells (PBPC) rescue after high-dose chemotherapy (HDCT), 23 consecutive patients aged less than 60 years with poor-prognosis, high-grade non-Hodgkin's lymphoma (NHL) were entered into a prospective randomized trial between May 1993 and September 1995. Patients were randomized to receive either PBPC alone (n = 12) or PBPC+G-CSF (n = 11) after HDCT with busulphan and cyclophosphamide. G-CSF (300 microg day[-1]) was given from day +5 until recovery of granulocyte count to greater than 1.0 x 10(9) l(-1) for 2 consecutive days. The mean time to achieve a granulocyte count > 0.5 x 10(9) l(-1) was significantly shorter in the G-CSF arm (9.7 vs 13.2 days; P<0.0001) as was the median duration of hospital stay (12 vs 15 days; P = 0.001). In addition the recovery periods (range 9-12 vs 11-17 days to achieve a count of 1.0 x 10(9) l[-1]) and hospital stays (range 11-14 vs 13-22 days) were significantly less variable in patients receiving G-CSF in whom the values clustered around the median. There were no statistically significant differences between the study arms in terms of days of fever, documented episodes of bacteraemia, antimicrobial drug usage and platelet/red cell transfusion requirements. Taking into account the costs of total occupied-bed days, drugs, growth factor usage and haematological support, the mean expenditure per inpatient stay was pound sterling 6500 (range pound sterling 5465-pound sterling 8101) in the G-CSF group compared with pound sterling 8316 (range pound sterling 5953-pound sterling 15,801) in the group not receiving G-CSF, with an observed mean saving of 1816 per patient (or 22% of the total cost) in the G-CSF group. This study suggests that after HDCT and PBPC rescue, the use of G-CSF leads to more rapid haematological recovery periods and is associated with a more predictable and shorter hospital stay. Furthermore, and despite the additional costs for G-CSF, these clinical benefits are not translated into increased health care expenditure.  相似文献   
58.
This work investigates the effects of 0.1 and 0.2?wt.?% Al additions on bulk alloy microstructure and tensile properties as well as on the thermal behavior of Sn–1Ag–0.5Cu (SAC105) lead-free solder alloy. The addition of Al reduces the amount of Ag3Sn intermetallic compound (IMC) particles and leads to the formation of larger Al–Ag IMC particles. Moreover, the addition of Al suppresses the formation of Cu6Sn5 IMC particles and leads to the formation of larger Al–Cu IMC particles. The Al added solders show a microstructure with large primary β-Sn grains. The tensile tests show that the 0.1?wt.?% Al addition reduces the elastic modulus, yield strength and ultimate tensile strength (UTS). However, the 0.2?wt.?% Al addition brings the yield strength up to SAC105 level and the UTS up to level slightly higher than that of SAC105, while its effect on reducing the elastic modulus becomes less dependent compared with the 0.1?wt.?% Al addition. Moreover, both 0.1 and 0.2?wt.?% Al additions deteriorate the total elongation. The two additions of Al slightly increase the solidus and liquids temperatures, while slightly reduce the pasty range, hence allowing the use of the Al-containing Sn–1Ag–0.5Cu alloys, to be consistent with the conditions of usage for conventional Sn–Ag–Cu solder alloys.  相似文献   
59.
This study presents a new distance-based facility layout construction technique. Given a two-dimensional (i.e. single-floor) facility layout construction problem in which the order of placement of individual departments is known (a challenging problem in itself), the technique presented herein proposes the use of sub-departments and expected distance functions instead of centroid-to-centroid distances for the placement of departments. In this paper an expected distance function is defined as the probabilistic expectation of the particular distance metric of interest (rectilinear, Euclidean, etc.) in which the parameters involved are defined by random vectors in 2-dimensional Euclidean space. This study presents an enhanced facility layout construction technique that incorporates several enhancements over the well-known systematic layout procedure (SLP). The goal herein is to minimise the error induced by the use of the centroid-to-centroid distances between the departments inherent to the SLP.  相似文献   
60.
Uchayash  Sajid Mahfuz  Datta  Shamik  Touhami  Ahmed  Rahman  Al Mazedur  Huq  Hasina F. 《SILICON》2023,15(5):2323-2338
Silicon - Boron doped pSi was deposited on Si substrate in the RF magnetron sputtering system by varying three process parameters, namely-sputtering power, working pressure, and Ar gas flow rate....  相似文献   
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