Anomalous quantum efficiency for photoconduction and its power dependence in metal oxide semiconductor nanowires

The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed.

Dietary supplementation with N-carbamylglutamate increases the expression of intestinal amino acid transporters in weaned Huanjiang mini-pig piglets

Weaning is associated with reduced intestinal absorptive capacity in piglets. Our previous study indicated that dietary supplementation with N-carbamylglutamate (NCG) enhanced growth performance and improved intestinal function in weaned piglets. The present study was conducted to test the hypothesis that dietary supplementation with NCG may increase the growth performance of weaned piglets by regulating the expression of intestinal nutrient transporters, thus enhancing nutrient absorption. Twenty-four Huanjiang mini-pig piglets weaned at 21 d of age (3.17 ± 0.21 kg average BW) were randomly assigned to 2 dietary treatments consisting of a basal diet and the basal diet with 0.1% NCG supplementation for a 14-d period with 6 pens per treatment and 1 male and 1 female per pen. On d 14, 1 piglet was randomly selected from each pen for blood and tissue sampling. Dietary NCG supplementation enhanced (P < 0.05) growth rate and the efficiency of feed use in weaned Huanjiang mini-pig piglets. The NCG-supplemented diet increased (P < 0.05) mRNA expression levels of Slc6a19, Slc7a9, and Slc1a1 and the protein abundance of ASCT2, B(0)AT1, b(0,+)AT, y(+)LAT1, and EAAC1 in the jejunum. Furthermore, the contents of low density lipoprotein, ammonia, urea nitrogen, and AA as well as the activity of alkaline phosphatase in plasma were all altered (P < 0.05) by supplementation with NCG. These findings indicate that dietary supplementation with NCG may improve intestinal absorptive function in weaned piglets by increasing the expression of AA transporters in the intestine.

Fluorophore-labeled carbohydrate analysis of immunoglobulin fusion proteins: Correlation of oligosaccharide content with in vivo clearance profile

CTLA4 is a membrane receptor on cytotoxic T cells whose interaction with the B7 counterreceptor on B cells is important in alloantigen responses. Soluble recombinant human and murine CTLA4 were produced using either Chinese hamster ovary or NS-0 cell lines. Expression vectors were constructed containing the gene coding for the extracellular domain of CTLA4 fused to either human lgG1 hinge, CH2, and CH3 domains or murine lgG2a hinge, CH2, and CH3 domain genes. These glycoproteins were produced in hollow-fiber or packed-bed-type bioreactors and purified from conditioned media by protein A affinity chromatography. Batches of purified CTLA4lg were analyzed for size, composition, and isoelectric point (pl) patterns by standard protein methods; oligosaccharide and monosaccharide profiles using several carbohydrate specific techniques; and in vivo clearance profiles using a murine model. Significant differences were observed between lots in their pl, clearance, and crbohydrate profiles. Higher overall pl values correlated with accelerated alpha-phase clearance and changes in oligosaccharide composition as determined by lectin binding analysis and electrophoresis of fluorophore-conjugated carbohydrates. Preparations exhibiting slower clearance profiles had oligosaccharides with higher quantities of N-acetylneuraminic acid and were predominantly of an N-linked biantennary complex-type. Conversely, batches with accelerated clearance profiles had less detectable N-acetylneuraminic acid. Oligosaccharides from murine CTLA4lg produced in NS-0 cells had terminal N-glycolylneuraminic acid but no detectable N-acetylneuraminic acid and had concomitant accelerated clearance. These data suggest that the presence and quantity of N-acetylneuraminic acid is an important component in predicting CTLA4lg plasma clearance rates and that production lots can be analyzed for oligosaccharide heterogeneity and sialic acid content by electrophoresis of fluorophore-conjugated carbohydrates. (c) 1995 John Wiley & Sons, Inc.

Electron enrichment in 3d transition metal oxide hetero-nanostructures

Direct experimental observation of spontaneous electron enrichment of metal d orbitals in a new transition metal oxide heterostructure with nanoscale dimensionality is reported. Aqueous chemical synthesis and vapor phase deposition are combined to fabricate oriented arrays of high-interfacial-area hetero-nanostructures comprised of titanium oxide and iron oxide nanomaterials. Synchrotron-based soft X-ray spectroscopy techniques with high spectral resolution are utilized to directly probe the titanium and oxygen orbital character of the interfacial region's occupied and unoccupied densities of states. These data demonstrate the interface to possess electrons in Ti 3d bands and an emergent degree of orbital hybridization that is absent in parent oxide reference crystals. The carrier dynamics of the hetero-nanostructures are studied by ultrafast transient absorption spectroscopy, which reveals the presence of a dense manifold of states, the relaxations from which exhibit multiple exponential decays whose magnitudes depend on their energetic positions within the electronic structure.

Immobilization of horseradish peroxidase on silane-modified ceramics and their properties: potential for oily wastewater treatment

Horseradish peroxidase (HRP) is proved being effective in eliminating oil from aqueous solutions, but the elimination is expensive because free HRP can not be reused. In present work, HRP was successfully immobilized on cordierite porous ceramics support with a novel method of N-beta-aminoethyl-gamma-aminopropyl-trimethoxysilane modification and glutaraldehyde activation. Under the optimized immobilized conditions, the actual immobilized HRP was 1.16 mg/g support, the activity of the immobilized HRP could reach as high as 1379.4 U/g support. Experiment results showed that the properties of storage stability, acid-base stability and the tolerance to the pH fluctuation of the immobilized HRP were better than those of the free HRP. The operation stability of the immobilized HRP was also good. The immobilized HRP is suitable for the oily wastewater treatment because of its reusability proved in this work.

Mount agung eruption provides test of a global climatic perturbation

The Mount Agung volcanic eruption in 1963 provides the best-documented global radiative perturbation to the earth's atmosphere currently available. Data on stratospheric aerosols produced by this eruption have been used as input to a model for the atmospheric thermal structure. The computed magnitude, sign, and phase lag of the temperature changes in both the stratosphere and the troposphere are in good agreement with observations, providing evidence that the climatic response to a global radiative perturbation is significant, as well as support for the use of theoretical models to predict climatic effects.

Magnetically enhanced high-specificity virus detection using bio-activated magnetic nanoparticles with antibodies as labeling markers

This study describes magnetically driven suppression of cross-reactions among molecules. First, the magnetic nanoparticles are coated with bio-probes and dispersed in liquid. The bio-probes can then bind with homologous or heterologous bio-targets. When alternating-current (ac) magnetic fields are applied, magnetic nanoparticles rotate driven by ac magnetic fields. Thus, the bio-targets bound on the surface of magnetic nanoparticles experience a centrifugal force. The centrifugal force can be manipulated by adjusting the angular frequency of the rotating magnetic nanoparticles. The angular frequency is determined by the applied ac magnetic field frequency. Since the binding force for good binding is much higher than that of poor binding, frequency manipulation is needed for the centrifugal force to be higher than the poor-binding force but lower than the good-binding force. Therefore, poor binding which contributes to cross reactions between molecules can be suppressed efficiently by control of the ac magnetic field frequency.

Measurement and receptor modeling of atmospheric polycyclic aromatic hydrocarbons in urban Kaohsiung, Taiwan

The concentrations of 21 individual polycyclic aromatic hydrocarbons (PAHs) and total suspended particles (TSPs) were measured using high-volume air samplers at Tzuo-Yin and Hsiung-Kong sites in Kaohsiung City, Taiwan, for four seasons from 2005 to 2006. The gaseous and particulate phases of individual PAHs were identified using a gas chromatograph with a flame-ionization detector (GC/FID). Measurements show that the concentrations of total (gas+particulate) PAHs generally followed the seasonal variations of the concentrations of TSP (107.2-117.1 microg m(-3)), being the highest in winter (143.9-182.9 ng m(-3)) and lowest in summer (81.4-95.2 ng m(-3)) at both sites. Most PAH species were low-weight PAHs (approximately 80.8-82.0%), followed by high-weight PAHs (10.5-14.6%) and medium-weight PAHs (6.5-6.8%). The fractions of gaseous PAHs decreased with molecular weight or ring number. The particle phase (60.2(73.5%) dominated the high-weight PAHs. Results of receptor model show that industrial combustions (49.1-63.7%) contributed most to ambient PAHs, followed by restaurant emissions (18.4-39.7%) and mobile sources (11.3-22.8%) at the Tzuo-Yin site. At the Hsiung-Kong, mobile sources (49.5-63.3%) contributed most to ambient PAHs, followed by restaurant emissions (19.8-36.6%) and industrial combustions (13.7-27.1%). The differences in the results at the two sites are mainly attributed to the different industries at each site.

Ultra-highly sensitive and wash-free bio-detection of H5N1 virus by immunomagnetic reduction assays

A platform for assaying avian influenza H5N1 viruses that involves measuring the ac immunomagnetic reduction of a magnetic reagent mixed with a detected sample is developed. The magnetic reagent contained magnetic nanoparticles coated with antibodies. To achieve an ultra-high sensitivity assay, a system utilizing a high-transition-temperature superconducting quantum interference device was used to sense the immunomagnetic reduction of the reagents. The results confirmed the ultra-high sensitivity of the immunomagnetic reduction assay on H5N1.

Primary immune surveillance: some like it hot

The thermal element of fever has been found to be beneficial in models of infectious disease. The contributions of fever-range temperatures to the efficacy of the adaptive immune response have only begun to be delineated. There is accumulating evidence that fever-range thermal stress bolsters primary immune surveillance of lymph nodes and Peyer patches by augmenting lymphocyte extravasation across specialized vessels termed high endothelial venules. Molecular mechanisms have recently come to light by which the thermal component of fever alone may promote lymphocyte trafficking, and thereby the probability of mounting a defense against microbial infection. Acquired knowledge of the molecular changes associated with thermal stress may allow for the development of novel therapies for a variety of disease processes.

Patterned nucleation control in vacuum deposition of organic molecules

We report a generally applicable method to pattern organic molecules on mesoscopic scales. In our method, organic molecular beam deposition was conducted on substrate surfaces prepatterned with materials to which the organic molecules have larger binding energies in comparison to the substrate. Fully uniform nucleation control at these predefined locations can be achieved by an appropriate selection of the growth parameters including temperature and deposition rate. The physical mechanisms involved are studied by Monte Carlo simulations and stand in good agreement with the experimental findings.

Efficacy of tadalafil in Egyptian and Turkish men with erectile dysfunction

A randomised, double-blind, parallel, placebo-controlled, 12-week study was carried out to evaluate the efficacy and safety of 20-mg tadalafil taken 'as needed' in a population of men with erectile dysfunction (ED) from Egypt and Turkey. One hundred and thirty-two patients were randomised in this study. Tadalafil was superior to placebo on all three co-primary efficacy end points. The mean change from baseline for the erectile function domain of the International Index of Erectile Function was 9.3 +/- 0.8 for the tadalafil group and 2.3 +/- 1.6 for the placebo group. Tadalafil-treated patients reported a significantly greater improvement in the mean percentage of successful penetrations (tadalafil: 34.5 +/- 4.1; placebo: -4.6 +/- 8.1) and successful intercourse attempts (tadalafil: 52.2 +/- 3.8; placebo: 16.8 +/- 7.8) than placebo-treated patients as measured by the Sexual Encounter Profile. Tadalafil was generally well tolerated with 82% of adverse events being mild in severity. Tadalafil 20-mg taken 'as needed' significantly improved the erectile function in Egyptian and Turkish men with ED.

[Agrobacterium-mediated transformation of rice mature embryos and regeneration of transgenic plants with Metr gene]

The mature embryos of a Japonica rice, Guanglingxiangnuo, were used for the study on optimization of Agrobacterium-mediated transformation. Several factors affecting the transformation were investigated and a suitable transformation system was set up. For this transformation system, the HRM medium, based on the MS medium, was suitable for inducing callus from rice mature embryos. The suitable time span of initial culture in this medium was 7-8 days before co-culturing with Agrobacterium and suitable medium for selection was CC medium. Using this transformation system, the Metr gene was introduced into Guanglingxiangnuo, and many transgenic plants were obtained. Most of these transgenic rice plants were confirmed by PCR technique and basta resistance, indicating the T-DNA had been integrated into the genome of transgenic rice plants.

[Human resources allocation in centers of disease prevention and control in China]

OBJECTIVE

To compare the human resources allocation of CDC in different areas and different levels.

METHODS

By stratified cluster sampling we get 70 CDC's manpower data, which come from different areas(east, middle part, west)and different levels (province, city, county).

RESULTS

(1) The average number of CDC's staff is 62. (2)CDC of province level are understaffed by 15%, while CDC of county level are overstaffed by 3%, and CDC of county level are overstaffed by 12%. (3) Structure of age: The average age of CDC's staff is 62, people under 35 years old in CDC is 39.4%, people above 55 years old is 3.5% (4) Structure of education: People with graduate degree are only 0.8%, and people come from technicalsecondary school are 57.0%. (5) Structure of specialty: A majority of people's majors are clinical medicine, and the percent of people having a non-medical-major are 36.6%. (6) Area distributing. Distribution of average quality score of staff are imbalance in different areas, the average quality score of staff in east area are 1.07 times than that in middle area, and 1.12 times than that in west area.

[Implementation analysis of public functions of 161 centers of disease prevention and control in 7 provinces]

OBJECTIVE

To evaluate the implementation of public function and items of the centers of disease prevention and control (CDC).

METHODS

161 centers of disease prevention and control have been investigated by two-stage stratified sampling. The implementation analysis of public function and items of CDC is measured by multiplying average operational proportion and average operational degree.

RESULTS

(1) For investigated centers, the average rate of function implementation is 42.9%, with 56.0% at provincial level and 43.7% at city level, 41.3% for the county level, while 49.3% in east areas, 45.4% in middle areas and 35.3% in west areas. (2) Among all 7 functional items, the implemented rate of disease prevention and control is 54.3%, 65.8% for emergency treatment, 35.0% for epidemic situation report and information management of health relative factors, 31.3% for inspection and control of health risk factors, 39.1% for the laboratory examination and evaluation, 36.4% for health education and health promotion, and 56.7% for technological guidance and application study.

CONCLUSION

The implemented degree of public function of CDC was generally lower, varied with regions and levels. Among 7 public functional items, the emergency treatment function had the highest implementation, with the lowest for the inspection and control of health relative factors.

[Operational proportion of the public function and items of 161 centers of disease prevention and control in 7 provinces]

OBJECTIVE

To explicate the operational proportion of public function and items of the centers of disease prevention and control (CDC).

METHODS

161 CDC have been investigated by two-stage stratified sampling to provide the information about the operation of the public function and items of CDC.

RESULTS

(1) The average operational proportion investigated CDC is 71.7%, the province level 92.0%, the city level 73.7%, the county level 68.5%. East areas 76.5%, middle areas 71.5%, west areas 68.1%. (2) The operational proportion of disease prevention and control function and emergency treatment function were higher, but that of epidemic situation report and information management of health relative factor, inspection and control of health relative factor, and the laboratory examination and evaluation were lower.

CONCLUSION

Public function and items were rather poorly carried out by the centers of prevention and control in China, especially those in middle and west areas, and those in counties.

[Implementation analysis of public functions of centers of disease prevention and control of China]

OBJECTIVE

To evaluate the implementation of public function and items of the centers of disease prevention and control(CDC).

METHODS

161 centers of disease prevention and control have been investigated by two-stage stratified sampling. The implementation analysis of public function and items of CDC is measured by multiplying average operational proportion and average operational degree.

RESULTS

1. For investigated centers, the average rate of function implementation is 42.9% ,with 56.0% at provincial level and 43.7% at city level, 41.3% for the county level; while 49.3% in east areas, 45.4% in middle areas and 35.3% in west areas. 2. Among all 7 functional items, the implemented rate of disease prevention and control is 54.3%, 65.8% for emergency treatment, 35.0% for epidemic situation report and information management of health relative factors, 31.3% for inspection and control of health risk factors, 39.1% for the laboratory examination and evaluation, 36.4% for health education and health promotion, and 56.7% for technological guidance and application study.

CONCLUSION

The implemented degree of public function of CDC was generally lower, varied with regions and levels. Among 7 public functional items, the emergency treatment function had the highest implementation, with the lowest for the inspection and control of health relative factors.