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We conduct a laboratory experiment to investigate whether the rebate and matching subsidy schemes cause crowding-out or crowding-in effects (reductions or increases in amount donated) on individual net donations. We find that when the rebate subsidy scheme is implemented, it does not result in crowding-out or crowding-in effects on individual net donations. However, when the matching subsidy scheme is implemented, it encourages individuals to donate more and generates crowding-in effects on individual net donations.
One of the critical prerequisites for accurately measuring the mechanical properties of profiled fibers is the precise determination of their cross-sectional areas (CSAs). In this study, a new method is established for determining a single profiled fibers’ CSA based on the frozen section method and digital photo, pixel-ratio method (FS-DP). FS-DP is used to obtain a transverse section of a fiber, by acquiring an image of the cross section using optical microscopy or scanning electron microscopy, and then calculating the CSA using Photoshop. Using FS-DP, it was found that the shape of a fiber of silk changes little in a range of 50 μm, but varies considerably over a range of 1 m, while the CSA of cocoon silk (900 m) first increases and then decreases. Mechanical property tests showed that the elongation, strength, elastic modulus, and toughness values of the cocoon silk are consistent with those reported previously. Additionally, FS-DP was also used to observe other profiled fibers. The application tests indicated that FS-DP can be used to quickly and accurately obtain the CSA of a single profiled fiber, and that it is suitable for the large-scale determination and analysis of the mechanical properties of profiled fibers.
In this study, the influence of T5 heat treatment on tensile and fatigue behavior of hot-extruded Mg–10Gd–3Y (wt%) magnesium alloy has been investigated. High cycle fatigue tests were carried out at a stress rate (R) of −1 and a frequency of 100 Hz using hour-glass-shaped round specimens with a gauge diameter of 5.8 mm. The results show that fatigue strength (at 107 cycles) of Mg–10Gd–3Y magnesium alloy increases from 150 to 165 MPa after T5 heat treatment, i.e., the improvement of 10% in fatigue strength has been achieved. However, the crack growth resistance is lowered by T5 heat treatment. Results of microstructure observation and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analysis suggest that the fatigue strength in the Mg–10Gd–3Y magnesium alloy is determined by the threshold stress of basal slip, which is induced by solid solution hardening and precipitation hardening.
Avian influenza virus is acquiring the ability to cross the species barrier between birds and mammals. However, the genetic mechanism of this ability is not well known. We successfully rescued an influenza A virus A/Chicken/Guangdong/03 (H5N1), which is highly pathogenic to both SPF chickens and BALB/c mice, by plasmid-based reverse genetics. The rescued virus, R-A/Chicken/Guangdong/03 (R-CG), and the wild-type A/Chicken/Guangdong/03 (W-CG) were found to share similar biological properties, such as in titres of 50% egg infectious dose (EID50), 50% tissue culture infectious dose (TCID50) and intravenous pathogenicity index (IPVI). R-CG, like W-CG, is highly pathogenic in mice following natural route infection. Both R-CG and W-CG viruses can be isolated from many organs of mice such as brain, lung, kidney and spleen. As a result, the constructed R-CG reverse genetic system can be used as a tool in the investigation of the molecular mechanism of infection of the mammalian host by avian influenza virus.
The homology of the sequences, reported and registered in GenBank, of different strains of Avian influenza virus (AIV), Newcastle disease virus (NDV), Classical swine fever virus (CSFV) and Foot-and-mouth disease virus (FMDV), was analysed and compared with each other. According to the properties of these viruses, the conservative domain of the M gene for AIV, the F gene for NDV, the 5' non-coding domain end for CSFV and the 2B gene for FMDV were selected for polymerase chain reaction (PCR) amplification. In order to prevent the formation of conformational dimers between different primers, four pairs of primers designed with the DNAsis system under the condition of G+C (50–60%),18–25 bp in length and Tm (72–85), were analysed using the VNTI5.5 system. The specific fragments amplified were as follows: 141 bp for FMDV, 200 bp for CSFV, 319 bp for NDV and 471 bp for AIV. The optimal conditions of PCR for each virus mentioned above were determined by orthogonal assay, and two or four of the four pairs of primers were then combined and used for amplification trials. The results showed that four specific fragments of different lengths would be successfully amplified in one tube at the same time. The products of PCR were tested to be specific by sequencing. Out of 46 pathological samples detected with the multiple PCR, there were 5 AIVs, 7 NDVs, 15 CSFVs and 6 FMDVs. The amplification above was identified with a single PCR. On the other hand, the results corresponded to those of electronic microscopy, haemagglutination (HA) and enzyme-linked immunosorbent assay (ELISA). The method described here is practicable, sensitive, specific, simple and cheap. It could be used for diagnosing AIV, NDV, CSFV and FMDV in different animals.
Indwelling urinary catheters are the most common source of infections in intensive care units (ICUs). The aim of this study was to evaluate the efficacy of nurse-generated daily reminders to physicians to remove unnecessary urinary catheters 5 days after insertion.
A time-sequence nonrandomized intervention study.
Adult ICUs (medical, surgical, cardiovascular surgical, neurosurgical, and coronary care) of a tertiary-care university medical center.
All patients admitted to the adult ICUs during a 2-year period. The study consisted of a 12-month observational phase (15,960 patient-days) followed by a 12-month intervention phase (15,525 patient-days).
Daily reminders to physicians from the nursing staff to remove unnecessary urinary catheters 5 days after insertion.
The duration of urinary catheterization was significantly reduced during the intervention phase (from 7.0 ± 1.1 days to 4.6 ± 0.7 days; P < .001). The rate of catheter-associated urinary tract infection (CAUTI) was also significantly reduced (from 11.5 ± 3.1 to 8.3 ± 2.5 patients with CAUTI per 1,000 catheter-days; P = .009). There was a linear relationship between the monthly average duration of catheterization and the rate of CAUTI (r = 0.50; P = .01). The excess monthly cost of antibiotics for CAUTI was reduced by 69% (from $4,021 ± $1,800 to $1,220 ± $941; P = .004).
This study demonstrated that a simple measure instituted as part of a continuous quality improvement program significantly reduced the duration of urinary catheterization, rate of CAUTI, and additional costs of antibiotics to manage CAUTI.
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