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  • Author: Yu Zhou x
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Abstract

Bone marrow microvessel plays an important role in the onset and progression of hematologic diseases whose genesis is regulated by a variety of regulatory factors. Since abnormal angiogenesis has been found in a number of malignant and non-malignant hematologic diseases, microvessel density can be a valuable prognostic indicator, and also a stratifying factor in some of these diseases. In some cases, inhibiting or stimulating angiogenesis with certain treatments may be very important in improving therapeutic outcomes. However, mechanisms underlying these effects are yet to be further investigated.

Abstract

The abnormal phenomenon occurring in sensor calibration is an obstacle to product development but a useful guideline to product improvement. The sensitivity jump of micro accelerometers in the calibrating process is recognized as an important abnormal behavior and investigated in this paper. The characteristics of jumping output in the centrifuge test are theoretically and experimentally analyzed and their underlying mechanism is found to be related to the varied stiffness of supporting beam induced by the convex defect on it. The convex defect is normally formed by the lithography deviation and/or etching error and can result in a jumping stiffness of folded microbeams and further influence the sensitivity when a part of the bending beams is stopped from moving by two surfaces contacting. The jumping level depends on the location of convex and has nothing to do with the contacting properties of beam and defects. Then the location of defect is predicted by theoretical model and simulation and verified by the observation of micro structures under microscopy. The results indicate that the tested micro accelerometer has its defect on the beam with a distance of about 290μm from the border of proof mass block.

Abstract

Objective To investigate the relationship between single nucleotide polymorphisms (SNPs) of the interleukin-4 (IL-4) gene and outcome of hepatitis B virus (HBV) infection in a Chinese Han population.

Methods Total of 501 patients with chronic hepatitis B virus (HBV) infection and 301 controls with selflimiting HBV infection were studied. Three tag SNPs in the IL-4 gene (rs2227284G/T, rs2243283C/G and rs2243288A/G) were genotyped by the Multiplex snapshot technique. The genotype and allele frequencies were calculated and analyzed.

Results The three SNPs showed no significant genotype/allele associations with chronic HBV infection. Overall allele P values were: rs2227284, P = 0.655, odds ratio (OR) [95% confidence interval (CI)] = 1.070 (0.793-1.445); rs2243283, P = 0.849, OR (95% CI) = 0.976 (0.758-1.257); rs2243288, P = 0.659, OR (95% CI) = 1.060 (0.818-1.375). Overall genotype P values were: rs2227284, P = 0.771; rs2243283, P = 0.571; rs2243288, P = 0.902. There were no statistically significant differences between patients with chronic HBV infection and controls. Haplotypes generated by these three SNPs also had no significant differences between the two groups.

Conclusions The three tag SNPs of IL-4 were not associated with the outcome of HBV infection in the Han Chinese population.

Abstract

Objective To develop an effective and specific medicine targeting hepatitis B virus (HBV) pregenome. Based on the identified accessible target sites for hammerhead ribozyme in our previous researches, a recombinant hepatitis delta virus (HDV) ribozyme was chosen and used to demonstrate the effective cleavage in vitro and in vivo.

Methods Three hammerhead ribozymes for potential target sites (S, X and C genes) and co-expression plasmid (pTr-dB, pTdδ-dB, pTrX-dB and pTrC-dB) as well as four HDV-ribozyme chimera constructs with HBV (pTdXX, pTdXC, pTdSX and pTdSC) were severally chosen to validate the inhibition of the replication and expression of HBV. The co-expression plasmids (pTdδ and pTr-Db) in physiological saline were hydrodynamically injected to mice by tail vein.

Results Compared with the group injected with pTr-dB in Huh-7 cell, hepatitis B surface antigen (HBsAg) was reduced by 31% in the group injected with pTdδ-dB, by 54%, 26%, 72% and 97% in the group injected with recombinant-ribozymes pTdSX, pTdSC, pTdXC and pTdXX, respectively. The inhibiting effects of endogenous ribozymes RzX and RzC on the HBsAg expression were 66% and 57%, respectively. Compared with the positive control, the amount of HBsAg was decreased in mice injected with pTdXX through tail vein by 88% and 96% on the second day and the third day, respectively. HBsAg was undetectable on the 6th day and could not primitively be detected on the 9th day in the sera from all mice. HBV DNA was not detected in the sera of BALB/c mice injected with pTdXX-dB, pTrX-dB or replicating-defective plasmid pHBV, while HBV DNA replication in control group could be detected on the 6th day. While HBcAg could not be detected in liver tissues of mice injected with plasmid pTdXX-dB on the 3rd day.

Conclusions Encoding regions of HBV S, C and X gene were the effective cleavage sites for hammerhead ribozyme in vitro and in vivo, which provides basis for further construction of therapeutic recombinant HDV and the development of targeting antiviral gene therapy.

Abstract

The effects of natural clinoptilolite (NCLI) and modified clinoptilolite (MCLI) were evaluated in broilers challenged with lipopolysaccharide (LPS) in a 21-d feeding trial. A total of 288 one-day-old chickens were allocated into three treatment groups: control, NCLI (2%) and MCLI (2%). Half of the birds from each treatment group were challenged with either 0.9% NaCl solution or LPS (250 μg/kg body weight, orally administered) at 16, 18 and 21 d of age. Before the LPS challenge, no dietary effect on bird growth performance was found (P>0.05). When LPS was orally administered, no significant changes in growth performance of broilers was found (P>0.05). However, small intestinal morphology and development, malondialdehyde (MDA) content of the jejunual and ileal mucosa, and superoxide dismutase (SOD) activity of the ileal mucosa were significantly affected (P<0.05). Supplementation with NCLI and MCLI significantly decreased the MDA contents of the jejunual and ileal mucosa and improved the SOD activity of the ileal mucosa and the development of the small intestine compared with the control group (P<0.05). The results indicated that NCLI and MCLI additions in feed had protective effects on the gut health of broilers against LPS challenge.

Abstract

Motivated by ideas from two-step models and combining second-order TV regularization in the LLT model, we propose a coupling model for MR image reconstruction. By applying the variables splitting technique, the split Bregman iterative scheme, and the alternating minimization method twice, we can divide the proposed model into several subproblems only related to second-order PDEs so as to avoid solving a fourth-order PDE. The solution of every subproblem is based on generalized shrinkage formulas, the shrink operator or the diagonalization technique of the Fourier transform, and hence can be obtained very easily. By means of the Barzilai–Borwein step size selection scheme, an ADMM type algorithm is proposed to solve the equations underlying the proposed model. The results of numerical implementation demonstrate the feasibility and effectiveness of the proposed model and algorithm.

Abstract

Fibers are raw materials used for manufacturing yarns and fabrics, and their properties are closely related to the performances of their derivatives. It is indispensable to implement fiber identification in analyzing textile raw materials. In this paper, seven common fibers, including cotton, tencel, wool, cashmere, polyethylene terephthalate (PET), polylactic acid (PLA), and polypropylene (PP), were prepared. After analyzing the merits and demerits of the current methods used to identify fibers, near-infrared (NIR) spectroscopy was used owing to its significant superiorities, the foremost of which is it can capture the tiny information differences in chemical compositions and morphological features to display the characteristic spectral curve of each fiber. First, the fibers’ spectra were collected, and then, the relationships between the vibrations of characteristic chemical groups and the corresponding wavelengths were researched to organize a spectral information library that would be beneficial to achieve quick identification and classification. Finally, to achieve intelligent detection, pattern recognition approaches, including principal component analysis (PCA) (used to extract information of interest), soft independent modeling of class analogy (SIMCA), and linear discrimination analysis (LDA) (defined using two classifiers), assisted in accomplishing fiber identification. The experimental results – obtained by combining PCA and SIMCA – displayed that five of seven target fibers, namely, cotton, tencel, PP, PLA, and PET, were distributed with 100% recognition rate and 100% rejection rate, but wool and cashmere fibers yielded confusing results and led to relatively low recognition rate because of the high proportion of similarities between these two fibers. Therefore, the six spectral bands of interest unique to wool and cashmere fibers were selected, and the absorbance intensities were imported into the classifier LDA, where wool and cashmere were group-distributed in two different regions with 100% recognition rate. Consequently, the seven target fibers were accurately and quickly distinguished by the NIR method to guide the fiber identification of textile materials.

Abstract

Background: At present, patients with end-stage renal failure (ESRD) face the question of how to achieve adequate dialysis to maintain their survival with the best quality of life as long as possible. Therefore, the choice of suitable dialysis methods and dialysis dose is important.

Objective: To find suitable dialysis methods and an appropriate dialysis dose for patients with ESRD.

Methods: Our research compares the long-term clinical effects between the patients undergoing continuous ambulatory peritoneal dialysis (CAPD), daytime ambulatory peritoneal dialysis (DAPD), and hemodialysis (HD). Thirty-two patients subjected to peritoneal dialysis were selected and divided into group A (n = 16) and group B (n = 16), group A was treated by using the traditional CAPD pattern; group B was treated by using DAPD. Forty-six patients of renal failure at final stage were divided into group A (n = 23) and group B (n = 23), group A was treated by using a HD method, group B was treated by using a DAPD method.

Results: When the same dialysis dose was applied, the patients with long-term DAPD treatment can obtain satisfactory clinical therapeutic efficacy for the period of maintenance dialysis, thoroughness of dialysis, maintenance of nutritional status, blood pressure regulation, reduction in incidence rate of peritoneal infection, maintenance of relatively high activity in daily life and alleviation in depression, comparable to patients treated with traditional CAPD or HD methods.

Conclusion: The long-term clinical effects of DAPD are comparable to CAPD or HD.

Abstract

This paper presents a novel phase-shift arctangent (PSA) interpolation method to improve the measurement accuracy of a planar capacitive incremental displacement sensor. Signals of planar capacitive micro-sensors acquire waveform errors, including sensitivity differences and phase-shift errors, because of static errors and dynamic disturbances. In the proposed PSA scheme, such errors are removed completely by loading a particular arctangent function. Moreover, measuring efficiency of the proposed planar capacitive sensors is improved by combining coarse measurement and fine estimation. Experiments show unanimous results to model-based fitting. When electrode length is four times the gap distance, applying the PSA interpolation method decreases waveform errors from more than 4 % to 1.72 %.

Abstract

This paper proposes a novel method of key-frame extraction for use with motion capture data. This method is based on an unsupervised cluster algorithm. First, the motion sequence is clustered into two classes by the similarity distance of the adjacent frames so that the thresholds needed in the next step can be determined adaptively. Second, a dynamic cluster algorithm called ISODATA is used to cluster all the frames and the frames nearest to the center of each class are automatically extracted as key-frames of the sequence. Unlike many other clustering techniques, the present improved cluster algorithm can automatically address different motion types without any need for specified parameters from users. The proposed method is capable of summarizing motion capture data reliably and efficiently. The present work also provides a meaningful comparison between the results of the proposed key-frame extraction technique and other previous methods. These results are evaluated in terms of metrics that measure reconstructed motion and the mean absolute error value, which are derived from the reconstructed data and the original data.