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The aim of this study was to clarify the pressure distribution of patient lying with varied supine angle on the standard hospital mattress (SHM) and sheep skin mattress (SSM), and then to compare the pressure relieving of those two kinds of mattresses which have been widely used in the pressure prevention. Eighteen healthy students were recruited from the university. Pressure distribution of SHM and SSM were measured by mFLEX measurement system in the supine angle of 0°, 30°, 60° and 90°. Pressure areas were divided into four parts: total, back, sacrum and heel area, under which peak pressure (PP) (mmHg), mean pressure (MP) 2 (mmHg) and contact area (CA) (cm ) were calculated. One-way ANOVA shows that with the supine angle change from the level to the vertical status, PP and CA at sacrum area was increasing as well, but PP at sacrum was still high in the 90° supine angle; further Paired T test records that majority PP values were proved to be significantly reduced by the usage of SSM in each supine angle, in contrast with the control group of standard hospital mattress and pressure reduction of MP was limited. Although positive outcomes were observed in each supine angle when the SSM was applied, further improvement of SSM in the aspect of shape was still required, such as a 3D structure was introduced to lower the higher pressure at the sacrum area. [ABSTRACT FROM AUTHOR]

Structural health monitoring (SHM) can enhance the functionality of structures, improve its safety and reliability, reduce maintenance costs, and increase the service life. A new kind of SHM technology based on piezoelectric ceramic transducers is an effective way to realize the prospective functions. However, many of piezoelectric ceramic SHM systems, which are complicated, weighty, and having much equipment, are mainly used for laboratory researches. In order to meet the needs of engineering applications, a portable piezoelectric concrete SHM system which uses the virtual instrument technology is proposed and produced in this paper. The developed system which is based on piezoelectric transducers can be realized to monitor online vibration accelerations, dynamic stresses, concrete cracks, and so forth. The function of this integrated system has been effectively proved in test and in an engineering application. The experimental and applied results show that the system is reliable, of high degree of automation, and portable. The work provides important technical support for improvement of structure design and monitoring of structural health status. [ABSTRACT FROM AUTHOR]

Biodegradable bio-board is held together by the self-bonding ability of natural fibre rather than by the synthetic resin adhesives used in traditional fibreboard. This provides a promising way to reduce the use and release of toxic substances. However, the hydrophilic characteristic of natural fibres gives bio-board poor water resistance compared to conventional fibreboards. Therefore, the objective of this study was to fabricate a hybrid bio-board in a wet forming process using soybean straw fibre with polylactic acid (PLA) added as a binder at different mass percentages. The effects of applied pressure during fabrication on the mechanical properties, water resistance properties, and wettability of hybrid bio-board were investigated. The thermal stability, spectroscopic characteristics, and morphological properties were also analysed. The addition of PLA weakened the bending strength and tensile strength of the hybrid bio-board made at each of three applied pressure levels. Fortunately, the hybrid bio-board with 10 and 30% PLA contents could maintain a considerable bending strength higher than 35 MPa when made with 8 MPa of applied pressure. The addition of PLA greatly improves the water-resistant performance of the board. Even with only 10% PLA, the water absorption and thickness swelling rates were reduced by more than half. We argue that PLA could be utilized as a latent natural binder to make hybrid bio-board using agricultural straw fibre; however, an environmentally friendly coupling agent is needed to improve the mechanical properties. [ABSTRACT FROM AUTHOR]

Common visual codebook generation methods used in a bag of visual words model, for example, k-means or Gaussian Mixture Model, use the Euclidean distance to cluster features into visual code words. However, most popular visual descriptors are histograms of image measurements. It has been shown that with histogram features, the Histogram Intersection Kernel (HIK) is more effective than the Euclidean distance in supervised learning tasks. In this paper, we demonstrate that HIK can be used in an unsupervised manner to significantly improve the generation of visual codebooks. We propose a histogram kernel k-means algorithm which is easy to implement and runs almost as fast as the standard k-means. The HIK codebooks have consistently higher recognition accuracy over k-means codebooks by 2-4% in several benchmark object and scene recognition data sets. The algorithm is also generalized to arbitrary additive kernels. Its speed is thousands of times faster than a naive implementation of the kernel k-means algorithm. In addition, we propose a one-class SVM formulation to create more effective visual code words. Finally, we show that the standard k- median clustering method can be used for visual codebook generation and can act as a compromise between the HIK / additive kernel and the k-means approaches. [ABSTRACT FROM AUTHOR]

A cascade face detector uses a sequence of node classifiers to distinguish faces from nonfaces. This paper presents a new approach to design node classifiers in the cascade detector. Previous methods used machine learning algorithms that simultaneously select features and form ensemble classifiers. We argue that if these two parts are decoupled, we have the freedom to design a classifier that explicitly addresses the difficulties caused by the asymmetric learning goal. There are three contributions in this paper: The first is a categorization of asymmetries in the learning goal and why they make face detection hard. The second is the Forward Feature Selection (FFS) algorithm and a fast precomputing strategy for AdaBoost. FFS and the fast AdaBoost can reduce the training time by approximately 100 and 50 times, in comparison to a naive implementation of the AdaBoost feature selection method. The last contribution is a Linear Asymmetric Classifier (LAC), a classifier that explicitly handles the asymmetric learning goal as a well-defined constrained optimization problem. We demonstrated experimentally that LAC results in an improved ensemble classifier performance. [ABSTRACT FROM AUTHOR]

Multiple mouse lines lacking the orphan G protein-coupled receptor, GPR37L1, have elicited disparate cardiovascular phenotypes. The first Gpr37l1 knockout mice study to be published reported a marked elevation in systolic blood pressure (SBP; ∼60 mmHg), revealing a potential therapeutic opportunity. The phenotype differed from our own independently generated knockout line, where male mice exhibited equivalent baseline blood pressure to wild type. Here, we attempted to reproduce the first study by characterizing the cardiovascular phenotype of both the original knockout and transgenic lines alongside a C57BL/6J control line, using the same method of blood pressure measurement. The present study supports the findings from our independently developed Gpr37l1 knockout line, finding that SBP and diastolic blood pressure (DBP) are not different in the original Gpr37l1 knockout male mice (SBP: 130.9 ± 5.3 mmHg; DBP: 90.7 ± 3.0 mmHg) compared with C57BL/6J mice (SBP: 123.1 ± 4.1 mmHg; DBP: 87.0 ± 2.7 mmHg). Instead, we attribute the apparent hypertension of the knockout line originally described to comparison with a seemingly hypotensive transgenic line (SBP 103.7 ± 5.0 mmHg; DBP 71.9 ± 3.7 mmHg). Additionally, we quantified myocardial GPR37L1 transcript in humans, which was suggested to be downregulated in cardiovascular disease. We found that GPR37L1 has very low native transcript levels in human myocardium and that expression is not different in tissue samples from patients with heart failure compared with sex-matched healthy control tissue. These findings indicate that cardiac GPR37L1 expression is unlikely to contribute to the pathophysiology of human heart failure. NEW & NOTEWORTHY This study characterizes systolic blood pressure (SBP) in a Gpr37l1 knockout mouse line, which was previously reported to have ∼60 mmHg higher SBP compared with a transgenic line. We observed only a ∼27 mmHg SBP difference between the lines. However, when compared with C57BL/6J mice, knockout mice showed no difference in SBP. We also investigated GPR37L1 mRNA abundance in human hearts and observed no difference between healthy and failing heart samples. [ABSTRACT FROM AUTHOR]

Pathological left ventricular hypertrophy (LVH) occurs in response to pressure overload and remains the single most important clinical predictor of cardiac mortality. The molecular pathways in the induction of pressure overload LVH are potential targets for therapeutic intervention. Current treatments aim to remove the pressure overload stimulus for LVH, but do not completely reverse adverse cardiac remodelling. Although numerous molecular signalling steps in the induction of LVH have been identified, the initial step by which mechanical stretch associated with cardiac pressure overload is converted into a chemical signal that initiates hypertrophic signalling remains unresolved. In this study, we show that selective deletion of transient receptor potential melastatin 4 (TRPM4) channels in mouse cardiomyocytes results in an approximately 50% reduction in the LVH induced by transverse aortic constriction. Our results suggest that TRPM4 channel is an important component of the mechanosensory signalling pathway that induces LVH in response to pressure overload and represents a potential novel therapeutic target for the prevention of pathological LVH. [ABSTRACT FROM AUTHOR]

This study was aimed to explore a suitable heel height of shoes for driving. Fourteen healthy female students were recruited and five pairs of footwear with varied heel heights were randomly arranged to each participant; their insole plantar pressure and ankle motion in plantar and dorsal direction whilst stepping on the power and break pedal were recorded in a Suzuki 1.3L AT car, where the driving position was on the left side. One-mask model was used and peak pressure 2 (PP) (Kpa), contact area (CA) (cm ) and pressure time integral (PTI) (s·Kpa) under forefoot area were calculated. Our results show that in terms of ankle motion, it increased with the relative heel height; in terms of insole pressure, only the CA was sensitive to the augment of relative heel height. Based on the significant differences, 30 mm heel height was a criterion; when the heel height exceeded 30 mm, the ankle motion range and CA were significantly increased. Overall, the safe heel-height of driving shoe should not exceed 30 mm. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Because bacterial translocation from the gut is one of the important sources of bacterial infection in acute necrotizing pancreatitis (ANP), and growth hormone (GH) has the ability to promote intestinal epithelial proliferation, we investigated the effects of GH on bacterial translocation in a rat ANP model. METHODS: Acute necrotizing pancreatitis was induced in rats via injection of 5% sodium taurocholate into the biliopancreatic duct. The rats with ANP were treated with either human recombinant GH or a placebo. Laparotomized animals without ANP induction (sham operation) served as controls. Twenty-four hours after the operation, blood was drawn for bacterial culture and determinations of amylase, lipase and endotoxin. Peritoneal fluid and specimens of mesenteric lymph nodes (MLN), liver, pancreas and spleen were taken for bacterial culture by standard techniques. Intestinal mucosal permeability was assessed by measuring the movement of [125I]-labeled albumin from blood to the intestinal lumen. Insulin-like growth factor-1 (IGF-1) mRNA was detected in the liver and ileum by reverse transcription–polymerase chain reaction (RT-PCR). Morphological changes in the pancreas and ileum were also analyzed. RESULTS: Administration of GH significantly decreased the activity of serum amylase and lipase, decreased the plasma endotoxin level and reduced the incidence of bacterial translocation. Moreover, the survival rate of ANP rats was improved. The severity of inflammation in the pancreas and ileum was reduced by GH treatment. Ileal mucosal thickness, villus height and crypt depth in GH-treated rats were obviously increased as compared with those of ANP rats. The intestinal permeability was markedly decreased in the GH group as compared with the ANP group. GH treatment resulted in upregulation of IGF-1 mRNA expression in ileum, but not in liver. CONCLUSIONS: These results suggest that exogenous GH has beneficial effects in maintaining the... [ABSTRACT FROM AUTHOR]

Folate deficiency in early development leads to disturbance in multiple processes, including neurogenesis during which fibroblast growth factor (FGF) pathway is one of the crucial pathways. Whether folic acid (FA) directly affects FGF pathways to influence neurodevelopment and the possible mechanism remains unclear. In this study, we presented evidence that in human FA-insufficient encephalocele, the FGF pathway was interfered. Furthermore, in Brachyury knockout mice devoid of such T-box transcription factors regulating embryonic neuromesodermal bipotency and a key component of FGF pathway, change in expression of Brachyury downstream targets, activator Fgf8 and suppressor dual specificity phosphatase 6 was detected, along with the reduction in expression of other key FGF pathway genes. By using a FA-deficient cell model, we further demonstrated that decrease in Brachyury expression was through alteration in hypermethylation at the Brachyury promoter region under FA deficiency conditions, and suppression of Brachyury promoted the inactivation of the FGF pathway. Correspondingly, FA supplementation partially reverses the effects seen in FA-deficient embryoid bodies. Lastly, in mice with maternal folate-deficient diets, aberrant FGF pathway activity was found in fetal brain dysplasia. Taken together, our findings highlight the effect of FA on FGF pathways during neurogenesis, and the mechanism may be due to the low expression of Brachyury gene via hypermethylation under FA-insufficient conditions. [ABSTRACT FROM AUTHOR]

The purpose of this study was first to disclose motion compensation strategy of healthy preschoolers according to evaluate how the stride length changes and curve turnings affected their Centre of Mass (CoM) performances; and then to comprehend the process of children develop in motion. Ten healthy children aged around 6 and 9 adults aged 23-47 were recruited in this study. The CoM was calculated based on four key markers in pelvis and its trajectory in five tasks including the stride length changes (short stride, straight walking and long stride) and curve turnings (0°-30°-60°) were first recorded; and then variables such as trajectory of CoM in sagittal and coronal plane, Unit of Energy (uEN), Energy Kinetic (uEk) and Gravitational Potential Energy (uEg) in the critical gait period were analyzed. Results show that as the stride length increase, child accordingly enlarged their motion range of CoM both in mediolateral and vertical direction to assist the whole-body movement; meanwhile, children's uEN increased as the stride length prolonged. Further, since 10%GC, child's CoM shifted gradually to the curving direction (right) as curve turning angle aggregated; while, dramatic change occurred at 60%GC, where a larger CoM deviation was found in 60° than that of 30°. The uEN of children was low before 60%GC, but it raised prominently after 60%GC. Overall, adult-like CoM were partly found in healthy preschoolers when coping with varied gait tasks, however distinctions existed which demonstrated that compensative strategies of those children were still developing. [ABSTRACT FROM AUTHOR]

Finite element analysis (FEA) has been widely used in engineering and construction in simulating forces and interactions and its application in footwear have become quite ripe by being researched for over 30 years. The aim of this study was to investigate the slip resistance of the outsole to learn (1) the feasibility of FEA in the test of outsole slip resistance (2) frictional interactions between outsole and contact surface by experiment test and finite element analysis. A static friction tester was used for static slip resistance test and a SATRA STM 603 slip resistance tester was used for dynamic slip resistance test. Outcome showed that value of SCoF was a little bit higher than that of DCoF both in ET and FEA, and value of coefficients obtained in ET was higher. With the increase of COF value, the displacement of outsole decreased while stress of the outsole increased. In conclusion, FEA application is feasible in footwear resistance testing. Stability of the outsole with superior slip resistance is good in both longitudinal and transverse direction. During walking, it has a strong resistance to the slipping tendency to prevent tumble and sprain. [ABSTRACT FROM AUTHOR]

Since current literature does not explain how children aged 3-6 reacted when the walking direction was reversed or what its mechanism is, the aim of this study was to understand the mechanism of their 'Neuro-musculo-skeletal' systems in the process of direction changes, as well as its coordination features. The kinematics of forward walking (FW) and backward walking (BW) of 96 subjects were measured by the Coda motion system and their Euler angles in lower limb joints were first collected. According to the coordination algorithm, the phase angle (PA) in the knee and ankle and the continuous relative phase angle (CRP) between the two joints were calculated; further the mean, standard deviation (SD) and range of data for variables of PA and CRP were contrasted between FW and BW. All the statistical models were executed under SPSS with a significance level of 0.05 and a confidence interval of 95%. The results show that children in BW first had an unstable velocity in their ankles; further, PA in both their ankles and knees were distributed in a limited range. Meanwhile the key gait events were not obtained in BW in all age groups. A similar CRP was seen between FW and BW, but a significant difference existed between the two types of gait. The majority of the mean and range of PA and CRP were recorded with significant distinctions between FW and BW in each age group. Finally, significant gender differences existed in all variables of BW in each age group. Overall, although achieving the BW was easy for preschool toddlers (aged 3-6), but their coordination in lower-limb were still in developing and further fine tuning; moreover, their clues in backwarding also tell the detail of development in the 'Neuro-musculo-skeletal' system. [ABSTRACT FROM AUTHOR]

Background: Folic acid (FA) is an antioxidant that can reduce reactive oxygen species generation and can blunt cardiac dysfunction during ischemia. We hypothesized that FA supplementation prevents cardiac fibrosis and cardiac dysfunction induced by obesity. Methods: Six-week-old C57BL6/J mice were fed a high-fat diet (HFD), normal diet (ND), or an HFD supplemented with folic acid (FAD) for 14 weeks. Cardiac function was measured using a transthoracic echocardiographic exam. Phenotypic analysis included measurements of body and heart weight, blood glucose and tissue homocysteine (Hcy) content, and heart oxidative stress status. Results: HFD consumption elevated fasting blood glucose levels and caused obesity and heart enlargement. FA supplementation in HFD-fed mice resulted in reduced fasting blood glucose, heart weight, and heart tissue Hcy content. We also observed a significant cardiac systolic dysfunction when mice were subjected to HFD feeding as indicated by a reduction in the left ventricular ejection fraction and fractional shortening. However, FAD treatment improved cardiac function. FA supplementation protected against cardiac fibrosis induced by HFD. In addition, HFD increased malondialdehyde concentration of the heart tissue and reduced the levels of antioxidant enzyme, glutathione, and catalase. HFD consumption induced myocardial oxidant stress with amelioration by FA treatment. Conclusion: FA supplementation significantly lowers blood glucose levels and heart tissue Hcy content and reverses cardiac dysfunction induced by HFD in mice. These functional improvements of the heart may be mediated by the alleviation of oxidative stress and myocardial fibrosis. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are implicated in the pathogenesis of obesity. The aim of the present study was to characterize the miRNA profile associated with early childhood obesity in peripheral blood mononuclear cells (PBMCs). A total of 12 children (6 obese and 6 lean controls) aged 36 months old to 48 months old were recruited. The miRNA expression profile from PBMCs was detected using the multiplexed NanoString nCounter system. Bioinformatics was employed to detect target genes and miRNA‑regulated biological function. A total of 9 differentially expressed miRNAs were identified in obese children compared with lean children (P<0.05). Among the 9 miRNAs, miR‑199a‑3p/miR‑199b‑3p and miR‑4454 presented at least a 1.5‑fold change in expression. A total of 643 potential target genes were regulated by the three miRNAs, and 291 of the potential genes were involved in a protein interaction network. Gene ontology annotation indicated that 291 potential genes were enriched in 14 biological process annotations and 2 molecular function annotations. miRNA dysregulation may be involved in early childhood obesity. [ABSTRACT FROM AUTHOR]

Structural health monitoring (SHM) systems can improve the safety and reliability of structures, reduce maintenance costs, and extend service life. Research on concrete SHMs using piezoelectric-based smart aggregates have reached great achievements. However, the newly developed techniques have not been widely applied in practical engineering, largely due to the wiring problems associated with large-scale structural health monitoring. The cumbersome wiring requires much material and labor work, and more importantly, the associated maintenance work is also very heavy. Targeting a practical large scale concrete crack detection (CCD) application, a smart aggregates-based wireless sensor network system is proposed for the CCD application. The developed CCD system uses Zigbee 802.15.4 protocols, and is able to perform dynamic stress monitoring, structural impact capturing, and internal crack detection. The system has been experimentally validated, and the experimental results demonstrated the effectiveness of the proposed system. This work provides important support for practical CCD applications using wireless smart aggregates. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are important post-transcriptional regulators during adipocyte adipogenesis. MiR-206-3p, a tissue-specific miRNA, is absent in white adipocytes. In this study, we examined the roles of mmu-miR-206-3p in the adipogenic differentiation of 3T3-L1 preadipocytes. The miR-206-3p expression has shown an apparent decreasing trend after induction, and sustained low expression throughout the differentiation of 3T3-L1 cells. miR-206-3p blocked the adipogenic differentiation of 3T3-L1 cells by attenuating c-Met expression; the inhibition effect of miR-206 to the adipogenic differentiation can be counteracted by restoring c-Met expression. In addition, miR-206-3p decreased the phosphorylation of Akt, which is the downstream effector of c-Met in the PI3K/Akt signaling pathway. These data indicate that miR-206-3p inhibits adipocyte adipogenesis through silencing c-Met and subsequently inactivating the PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

Background/Aims: Obesity is a major contributor to the growing prevalence of metabolic and cardiovascular diseases. This study was designed to investigate the effect of folic acid (FA) on obese mice by detecting the genome-wide expression profile of lncRNAs and mRNAs in the heart. Methods: Heart samples were collected from mice fed with standard diet (SD), high- fat diet (HFD) and high-fat diet with FA intake (HFDF). LncRNAs and mRNAs between HFD and HFDF group were analyzed by lncRNA microarray. Nine lncRNAs and mRNAs were validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Bioinformatics prediction was used to investigate the potential function of these differentially expressed lncRNAs. Co-expresson analysis was used to determine the transcriptional regulatory relationship of differentially expressed lncRNAs and mRNAs between two groups. Results: The expression of 58,952 lncRNAs and 20,145 mRNAs in HFD and HFDF groups was profiled by using microarrays. Gene Ontology and pathway analyses indicated that the biological functions of differentially expressed mRNAs were related to inflammation, energy metabolism, and cell differentiation. Co-expression networks composed of lncRNAs and mRNAs were also constructed to investigate the potential regulatory roles of differentially expressed lncRNAs on mRNAs. LncRNAs, namely, NONMMUT033847, NONMMUT070811, and NONMMUT015327, were validated through qRT-PCR, and these lncRNAs may be important factors regulating inflammation, energy metabolism, and cell differentiation. The expression levels of Dnajbl, Egr2, Hba-a1, Illß, Cxcl2, and Tnfsf9 were significantly different between HFD and HFDF. Conclusions: Results suggested that FA may improve the cardiovascular function of obesity and contribute to those lncRNAs associated with inflammation and cell differentiation. In a nutshell, the present study identified a panel of lncRNAs and mRNAs that may be potential biomarkers or drug targets relevant to the high-fat diet related obesity. [ABSTRACT FROM AUTHOR]

The aim of this study was to find the features of balance control of cerebral palsy (CP) children by exploring the variances between the CP and TD groups in terms of centre of pressure (COP) deviation, velocity and sum of distances. Eighteen spastic diplegia children (CP) and 36 typical developed counterparts (TD) who were matching with age, height and weight were recruited and measured by pressure plate and then COP parameters such as Relative deviation in the X (Dxrel) and Y axis (Dyrel), Relative velocity in the X (Vxrel) and Y axis (Vyrel) and Relative sum distance in X (Dxrel) and Y axis (Dyrel). Independent T test and reliability analysis were carried out with significance level of 0.05 and confidence interval of 95%. Our results show that Dxrel, Vxrel, Vyrel, SumXrel and SumYrel of CP were significantly higher than those of TD; meanwhile COP of CP was always located at the medial side of foot which indicated a severe valgus and distances in anteriorposterior (AP) direction of CP were smaller than that of TD. At last, a reasonable repeatability was obtained for CP, since their COV of Dxrel, Dyrel, Vxrel, Vyrel, SumXrel and SumYrel CoV were overall <13%, whereas, with exception of ICC of Vxrel and SumXrel, ICC of Dxrel, Dyrel and SumYrel were higher than 0.5. Overall, in order to fulfill the balance control, strategies of foot valgus, larger deviation in medial-lateral (ML) direction, longer contact time and higher velocity in AP and ML directions were adopted by CP children. [ABSTRACT FROM AUTHOR]

This study was aimed at evaluating the reliability of Footscan plate system when measuring pressure in spastic diplegia children (CP). Eighteen CP and 36 typical developed counterparts (TD) with similar age, height and weight were recruited and their plantar pressure was measured in at least five trials. Three-mask 2 model was applied and plantar regions were divided into: forefoot, mid foot and hind foot, under which peak pressure (PP) (N/cm ), relative pressure time integral (PTIrel) (%) and relative contact area (CArel) (%) were calculated. Coefficient of variance (CoV) and intra class coefficient (ICC) were explored for each variable and region. Our outcomes show that in terms of CP, with the increasing of test times, ICC of PP increased, while those of PTIrel and CArel were lowered; additionally, ICC of TD of each pressure variable successively improved. A similar tendency was found for CoV. Considering entire feet of CP and five measurements, reliability of CArel was the best in the three areas; whereas PP and PTIrel were demonstrated to be less reliable, except for the midfoot area. In contrast, reliabilities of TD were shown to be good for all pressure variables under all three regions. Overall, reliability of Footscan plate system in the study of CP was moderate in most variables and under most plantar regions. Thereby, by increasing the test times to no less than five, this protocol could be applied in the clinical and scientific investigation of CP children. [ABSTRACT FROM AUTHOR]

Expansion of CAG/CTG trinucleotide repeats causes certain familial neurological disorders. Hairpin formation in the nascent strand during DNA synthesis is considered a major path for CAG/CTG repeat expansion. However, the underlying mechanism is unclear. We show here that removal or retention of a nascent strand hairpin during DNA synthesis depends on hairpin structures and types of DNA polymerases. Polymerase (pol) alone removes the 3′-slipped hairpin using its 3′-5′ proofreading activity when the hairpin contains no immediate 3′ complementary sequences. However, in the presence of pol β, pol δ preferentially facilitates hairpin retention regardless of hairpin structures. In this reaction, pol δ incorporates several nucleotides to the hairpin 3′-end, which serves as an effective primer for the continuous DNA synthesis by pol β, thereby leading to hairpin retention and repeat expansion. These findings strongly suggest that coordinated processing of 3′-slipped (CAG)n/ (CTG)n hairpins by polymerases δ and β on duringDNAsynthesis induces CAG/CTG repeat expansions. [ABSTRACT FROM AUTHOR]

Objective: To examine the association between the risk of neural tube defects (NTD) and maternal serum vitamin B12, folate and homocysteine in a high-risk area of China. Design: A case-control study was carried out in Luliang mountain area of Shanxi Province. Subjects/setting: A total of eighty-four NTD pregnancies and 110 matched controls were included in the study; their serum vitamin B12 and folate concentrations were measured by chemiluminescent immunoenzyme assay and total homocysteine concentrations by fluorescent polarisation immunoassay. Results: Serum vitamin B12 and folate concentrations were lower in NTD-affected pregnant women than in controls (P<0∙01). Serum total homocysteine was higher in the NTD group than in controls at less than 21 weeks of gestation (P<0∙01). Adjusted odds ratios revealed that women with lower vitamin B12 (adjusted OR54∙96; 95% CI 1∙94, 12∙67) and folate (adjusted OR=3∙23; 95% CI 1∙33, 7∙85) concentrations had a higher risk of NTD compared to controls. Based on dietary analysis, less consumption of meat, egg or milk, fresh vegetables and fruit intake would increase the risk of NTD. Conclusions: Lower serum concentrations of folate and vitamin B12 are related to the increased risk of NTD in high-risk populations. Both folate and vitamin B12 intake insufficiency could contribute to the increased risk of NTD. A dietary supplement, combining folate and vitamin B12, might be an effective measure to decrease the NTD incidence in these areas. [ABSTRACT FROM AUTHOR]

A method for adaptively selecting training data is proposed to improve the performance of adaptive beamforming. The method first measures the contribution of each snapshot to the covariance matrix required by the beamforming using the sparse iterative covariance-based estimation technique. Then, those snapshots making larger contributions are selected as the final training samples. The homogeneity of training samples can be improved significantly, and thus results in an evident performance improvement in adaptive beamforming. Simulation results demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]