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We adopt the tight-binding model and the mode-matching method to study the electrical modulation of the valley polarization in strained silicene constrictions. The effects of the potential energy, the external electric field, and the strain on the band structures and the transport property are investigated. The conductance shows a clear valley polarization and zero conductance in the absence of the electric field and the strain. It is found that the external electric field can open a clear bandgap and result in an extra zero conductance. However, the strain can not induce a bandgap, which only slightly change the energy band. Correspondingly, the strain has little effect on the system's conductance. The transport behavior of zero conductance is elucidated in terms of band structures of the silicene constriction. Therefore, one can realize an effective modulation of the valley-dependent transport of the silicene constriction by combining the potential energy and the electric field. The electrical modulation of the valley polarization and zero conductance can be exploited for silicene-based valleytronics devices. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the influence of different mid-stage N compensation timings on agronomic and physiological traits associated with grain yield and quality in field experiments. Two japonica rice cultivars with a good tasting quality (Nangeng 9108 and Nangeng 5055) were examined under eight N compensation timings (N1–N6: one-time N compensation at 7-2 weeks before heading; N7: split N compensation at 5 and 3 weeks before heading; N8: split N compensation at 4 and 2 weeks before heading) and a control with no N compensation. The highest yield was obtained with N7, followed by N3. The yield advantage is mainly attributable to the improved population structure (higher productive tiller rate with a stable number of effective panicles), higher total number of spikelets per unit area (large panicles with more grains per panicle), larger leaf area index in the late period and higher photosynthetic production capacity (more dry matter accumulation and transportation in the middle and late periods). Delaying N compensation timing improved the processing and nutritional quality of rice, but decreased the quality of appearance and cooking/eating traits. Our results suggest that, from the perspective of achieving relative coordination between high yield and high quality of japonica rice, the optimal N compensation should be divided equally at 5 and 3 weeks before heading. However, if simplifying the number of operations and the pursuit of eating quality were considered, one-time N compensation should be conducted at 5 weeks before heading. [ABSTRACT FROM AUTHOR]

Calculation of the EM scattered fields from a three-layer canopy faces intensive computational burden, when the area becomes large and obviously lames the application of the traditional serial algorithm. With the development of graphics hardware, the Graphics Processing Unit (GPU) can be used to calculate the electromagnetic (EM) scattering problems parallelly. In this paper, the Compute Unified Device Architecture (CUDA) is combined with the four-path method and the reciprocity theorem to improve the speed of calculating the EM scattering properties from a three layer-canopy which are simulated by employing the Monte-Carlo method. We get a highest speedup of 294 times in comparison with the original serial algorithm on a Core (TM) i5 CPU with a GTS460 GPU as a coprocessor. [ABSTRACT FROM AUTHOR]

κ-Casein is one of the major proteins in the milk of mammals. It plays an important role in determining the size and specific function of milk micelles. We have previously identified and characterized a genetic variant of yak κ-casein by evaluating genomic DNA. Here, we isolate and characterize a yak κ-casein cDNA harboring the full-length open reading frame (ORF) from lactating mammary gland. Total RNA was extracted from mammary tissue of lactating female yak, and the κ-casein cDNA were synthesized by RT-PCR technique, then cloned and sequenced. The obtained cDNA of 660-bp contained an ORF sufficient to encode the entire amino acid sequence of κ-casein precursor protein consisting of 190 amino acids with a signal peptide of 21 amino acids. Yak κ-casein has a predicted molecular mass of 19,006.588 Da with a calculated isoelectric point of 7.245. Compared with the corresponding sequences in GenBank of cattle, buffalo, sheep, goat, Arabian camel, horse, and rabbit, yak κ-casein sequence had identity of 64.76-98.78% in cDNA, and identity of 44.79-98.42% and similarity of 53.65-98.42% in deduced amino acids, revealing a high homology with the other livestock species. Based on κ-casein cDNA sequences, the phylogenetic analysis indicated that yak κ-casein had a close relationship with that of cattle. This work might be useful in the genetic engineering researches for yak κ-casein. [ABSTRACT FROM AUTHOR]

The aim of the present work was to investigate single nucleotide polymorphism (SNP) of growth hormone receptor ( GHR) gene exon 10, characterize the genetic variation in three Chinese indigenous goat breeds, and search for its potential association with cashmere traits. In this study, a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) protocol has been developed for rapid genotyping of the GHR gene in goats. One hundred seventy-eight goats from Liaoning Cashmere (96), Inner Mongolia White Cashmere (40), and Chengdu Grey (42) breeds in China were genotyped at GHR locus using the protocol developed. In all goat breeds investigated, a SNP in exon 10 of GHR gene has been identified by analyzing genomic DNA. The polymorphism consists of a single nucleotide substitution A → G, resulting in two alleles named, respectively, A and G based on the nucleotide at the position. The allele A was found to be more common in the animals investigated, and seems to be more consistent with cattle and zebu at this polymorphic site found in goats. The Hardy-Weinberg equilibrium of genotype distributions of GHR locus was verified in Liaoning Cashmere, and Inner Mongolia White Cashmere breeds. According to the classification of polymorphism information content ( PIC), Chengdu Grey was less polymorphic than Liaoning Cashmere and Inner Mongolia White Cashmere breeds at this locus. The phylogenetic tree of different species based on the nucleotide sequences of GHR gene exon 10 is generally in agreement with the known species relationship. No significant association was found between the polymorphism revealed and the cashmere traits analyzed in present work. [ABSTRACT FROM AUTHOR]

In step with the great efforts to find out the scattering contributions of a large number of samples in the vegetation canopy, intensive computational burden occurs and obviously lames the application of the traditional serial algorithm on the basis of the radiative transfer theory to evaluate the electromagnetic (EM) scattering from vegetations. Nevertheless, the Compute Unified Device Architecture (CUDA) gives developers access to the virtual instruction set and memory of the parallel computational elements in the CUDA compatible Graphics Processing Unit (GPU), which encourages us to develop a CUDA-based simulator for the solution. This paper analyzes the radiative transfer method and the CUDA architecture, and then presents a CUDA parallel algorithm for calculating the EM scattering from a two-layer vegetation canopy. In the CUDA-based simulation, with a GTS250 GPU as, which has 128 stream processors, coprocessor, tens of times speedup is obtained in comparison with the original serial algorithm. [ABSTRACT FROM AUTHOR]

Background and objective: 5-fluorouracil (5-FU) is still a widely used anticancer drug. More than 85% of the 5-FU administered is catabolized by dihydropyrimidine dehydrogenase (DPD) in the liver. However, mutations in the DPD gene have been found to be associated with low DPD activity causing severe complications. The purpose of this study was to determine the mutation frequency of four exons in Chinese cancer patients and the relationship between genotype and DPD activity. Methods: Samples from 142 cancer patients were investigated in this study. The DPD activity was determined by reversed-phase HPLC. Exons 2, 13, 14 and 18 were amplified by polymerase chain reaction (PCR), sequenced and analysed from both sense and antisense directions. Nonparametric one-sample Kolmogorov–Smirnov test was used for distribution analysis; two independent samples t-test and one-wayanova was performed for two groups and three groups analyses, respectively. Results and discussion: Plasma-DPD activities in the 142 cancer patients followed a Gaussian distribution. The mean plasma-DPD activity in women was lower than that in men ( P = 0·006). Four mutations, 85T>C(DPYD*9A), 1627A>G(DPYD*5), 1896T>C and 2194G>A(DPYD*6), were found in the 142 cancer patients. The following mutations reported by others were not detected: 61C>T, 62G>A, 74A>G, 1601G>A(DPYD*4), 1679T>G(DPYD*13), 1714C>G, 1897delC(DPYD*3) and IVS 14 + 1G>A. No significant correlation was found between three mutations [85T>C(DPYD*9A), 1627A>G (DPYD*5) and 1896T>C], and DPD activity was found. Conclusion: No clear correlation between the mutations studied and DPD activity could be established in this study. However, larger-scale prospective studies are needed to better assess the reported genotype–phenotype correlations. [ABSTRACT FROM AUTHOR]

Angiogenesis plays a pivotal role in tumor growth, tissue invasion and metastasis. Endostatin is an angiogenesis inhibitor and has been shown to reduce tumor growth in animal models. However, therapy with recombinant endostatin protein was hampered by its short half-life and very-low yield of bioactive protein. We performed a phase I dose–escalation clinical trial using intratumoral injection of an adenovirus containing human endostatin gene (Ad-rhE; E10A; 1010–1012 virus particles (vp)) in 15 patients with advanced solid tumors. We observed intratumoral injections of E10A without dose-limiting toxicity. Most frequently reported E10A-related adverse events were transient fever and local response. Distribution studies revealed that the vector was detected in the blood, throat and injection site, but rarely in the urine and stool. An increased endostatin expression was detected using enzyme immunoassay in serum in 13 of 14 treated patients throughout the period of treatment despite the presence of neutralizing antiadenovirus antibody. Median serum basic fibroblast growth factor levels decreased from 32.4 pg ml−1 at baseline to 24.9 pg ml−1 after 28 days of first treatment. Thus, direct intratumoral injection of up to 1012 vp of E10A to patients is well tolerated and further studies are necessary to define and increase clinical efficacy.Gene Therapy (2008) 15, 247–256; doi:10.1038/sj.gt.3303038; published online 20 December 2007 [ABSTRACT FROM AUTHOR]

Telomerase-negative cancer cells can maintain their telomeres by a recombination-mediated alternative lengthening of telomeres (ALT) process. We reported previously that sequestration of MRE11/RAD50/NBS1 complexes represses ALT-mediated telomere length maintenance, and suppresses formation of ALT-associated promyelocytic leukemia (PML) bodies (APBs). APBs are PML bodies containing telomeric DNA and telomere-binding proteins, and are observed only in a small fraction of cells within asynchronously dividing ALT-positive cell populations. Here, we report that methionine restriction caused a reversible arrest in G0/G1 phase of the cell cycle and reversible induction of APB formation in most cells within an ALT-positive population. We combined methionine restriction with RNA interference to test whether the following proteins are required for APB formation: PML body-associated proteins, PML and Sp100; telomere-associated proteins, TRF1, TRF2, TIN2 and RAP1; and DNA repair proteins, MRE11, RAD50, NBS1 and 53BP1. APB formation was not decreased by depletion of Sp100 (as reported previously) or of 53BP1, although 53BP1 partially colocalizes with APBs. Depletion of the other proteins suppressed APB formation. Because of the close linkage between ALT-mediated telomere maintenance and ability to form APBs, the eight proteins identified by this screen as being required for APB formation are also likely to be required for the ALT mechanism.Oncogene (2007) 26, 4635–4647; doi:10.1038/sj.onc.1210260; published online 5 February 2007 [ABSTRACT FROM AUTHOR]

With the increasing importance of SQUID-based magnetically labeled immunoassay, the study on the synthesis of controllable sizes of magnetic nanoparticles plays a role to promote the accuracy of the immunoassay. In this work, Fe3 O4 nano-particles coated with a suitable bio-probe (biotin) are synthesized through chemical co-precipitation process to probe the bio-target (avidin). Through the synthesis developed here, the particle hydrodynamic diameter can be adjusted from 30 to 90 mu, which provide candidates for probing various bio-targets in the future. The amount of the magnetically labeled avidin is then analyzed via measuring the saturated magnetization or the remanence of the sample by using a scum magnetometer. [ABSTRACT FROM AUTHOR]

A kind of magnetorheological elastomers based on polyurethane (PU)/silicone rubber (Si-rubber) hybrid is fabricated without applying magnetic fields. The MR effect is improved by optimizing preparation conditions, in particular by adjusting PU/Si-rubber ratio, and improving compatibility between PU and Si-rubber. The influences of the preparation condition and the relationship between the microstructure and MR effect of this kind of magnetorheological elastomers are discussed in detail. The results show that this kind of MR elastomers has better MR effect than that of MR elastomers based on pure Si-rubber or PU matrix with same testing conditions. SEM analysis indicates that the former forms a peculiar interpenetrating microstructure in the presence of PU in the matrix. The maximum increase in shear modulus of this kind of MR elastomers can be up to 0.5MPa when exposed to a magnetic field of about 0.2T. [ABSTRACT FROM AUTHOR]