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By applying the locally optimal rotation method to deal with the lowest eigenvalue of a Hessian matrix, we have efficiently incorporated the hyperdynamics method into the ab initio scheme. In the present method, we only need to calculate the first derivative of the potential and several more force calls in each molecular dynamics (MD) step, which makes hyperdynamics simulation applicable in ab initio MD simulations. With this implementation, we are able to simulate defect diffusion in silicon with boost factors up to 105. We utilized both direct MD and the hyperdynamics method to investigate diffusion of lithium atoms and silicon vacancies in silicon. We identified the complex diffusion process. The obtained diffusion coefficients of Li atoms and Si vacancies are in good agreement with the direct MD results. [ABSTRACT FROM AUTHOR]

Variations in running conditions cause fluctuation in the temperature field of precision machine tools, which inevitably results in thermal errors. To meet the demands of dynamic and time-varying temperature control capability, an active temperature control (ATC) method based on time grating principle is proposed, and the ATC system is developed. The ATC system contains main-loop and sub-loops. The oil target temperature in the sub-loop is determined according to the running parameters and the matching principle of the generalized heat generation–dissipation power. In accordance with the time grating principle, dynamic and differential oil temperature control of each sub-loop is achieved via the inlet time regulation of high-temperature (H-t) or low-temperature (L-t) oil in the main-loop. The main-loop H-t and L-t oil target temperatures are determined by the target range of the sub-loop temperature. The dynamic distribution of the refrigeration capacity and proportional heating mode is adopted to control the temperatures of H-t and L-t oil. By focusing on the feed system of precision machine tool, we carry out both dynamic simulation study and verification experiments, and the results show that the ATC method and system can effectively regulate the temperature field of precision machine tools, thus improving the thermal accuracy of the precision machine tool. [ABSTRACT FROM AUTHOR]

We consider the problem of resolving $r$ point sources from $n$ samples at the low end of the spectrum when point spread functions (PSFs) are not known. Assuming that the spectrum samples of the PSFs lie in low dimensional subspace (let $s$ denote the dimension), we can formulate it as a matrix recovery problem, followed by location estimation. By exploiting the low rank structure of the vectorized Hankel matrix associated with the target matrix, a convex approach called Vectorized Hankel Lift is proposed for the matrix recovery. It is shown that $n\gtrsim rs\log ^{4} n$ samples are sufficient for Vectorized Hankel Lift to achieve the exact recovery. For the location retrieval from the matrix, applying the single snapshot MUSIC method within the vectorized Hankel lift framework corresponds to the spatial smoothing technique proposed to improve the performance of the MMV MUSIC for the direction-of-arrival (DOA) estimation. [ABSTRACT FROM AUTHOR]

Aims: To demonstrate the noninferiority of alogliptin to acarbose, in terms of antidiabetic efficacy, in Chinese people with uncontrolled type 2 diabetes (T2D) and high cardiovascular risk. Materials and Methods: ACADEMIC (NCT03794336) was a randomized, open‐label, phase IV study conducted at 46 sites in China. Antidiabetic treatment‐naive or metformin‐treated adults with uncontrolled T2D (glycated haemoglobin [HbA1c] 58.0–97.0 mmol/mol) were randomized 2:1 to alogliptin 25 mg once daily or acarbose 100 mg three times daily for 16 weeks. All participants had a documented history of coronary heart disease or high cardiovascular risk at screening and received aspirin (acetylsalicylic acid) 100 mg daily throughout the trial. The primary endpoints were change in HbA1c versus baseline, and the incidence of gastrointestinal adverse events (AEs). Safety and tolerability were also assessed. Results: A total of 1088 participants were randomized. Alogliptin was noninferior to acarbose for the change in Week‐16 HbA1c (least‐squares mean change [standard error] –11.9 [0.4] vs. –11.4 [0.5] mmol/mol, respectively; difference between arms –0.5 [0.7] mmol/mol; 95% confidence interval –1.9 to 0.8 mmol/mol), and was associated with a lower incidence of gastrointestinal AEs (8.9% vs. 33.6%, respectively; P < 0.0001). More alogliptin than acarbose recipients achieved HbA1c <53.0 mmol/mol without gastrointestinal AEs (48.0% vs. 32.7%; P < 0.0001). Discontinuations due to treatment‐related AEs were less frequent with alogliptin than acarbose (0.3% vs. 2.5%). Conclusions: Glycaemic control was comparable between alogliptin and acarbose, but the gastrointestinal tolerability of alogliptin was better. More patients achieved target HbA1c without gastrointestinal AEs with alogliptin, suggesting that this agent may be preferred in clinical practice. [ABSTRACT FROM AUTHOR]

• A dual-layer analytical modeling approach that simplifies complex machine tool structural components into equivalent cuboids was presented. • An analytical modeling method for the predicting thermal characteristic of machine tool structural components via dual-layer equivalent cuboids has been proposed. • The mapping relationship between temperature field variations and equivalent thermal loads of the equivalent cuboids is unveiled. • Sensitivity coefficient of thermal power to thermal error is introduced to reveal the impact mechanism of thermal error caused by heat source conditions. Precision machine tools are sensitive to thermal effects. Thermal deformation of machine tool structural components can lead to changes in the relative pose between the spindle tool and the workpiece, causing thermally induced machining errors. Gaining insight into the mechanistic correlation between critical thermal condition parameters of heat sources and thermal errors in machine tools is essential to elevate the design of machine tool thermal attributes. To address this issue, this paper proposes a dual-layer equivalent analytical modeling method for characterizing the thermal properties of structural components. The construction of the temperature field analytical model for the dual-layer equivalent structure is achieved by setting and handling different interlayer heat flows and temperature boundary conditions. The dual-layer equivalent approach simplifies complex structural components into top and bottom layers, providing a more flexible and accurate capability for characterizing the thermal properties of structural components. This modeling method enables rapid prediction and evaluation of machine tool thermal characteristics. Furthermore, based on this analytical approach, the calculation method of sensitivity coefficient of thermal power to thermal error is proposed to elucidate the mapping relationship between different thermal condition parameters and thermal errors. This method facilitates the fast and accurate prediction of six thermally induced errors under various thermal conditions. Experimental results demonstrate that the key point temperature deviation predicted using the dual-layer analytical modeling method is less than 0.8 °C, and the thermally induced axial linear error deviation is less than 1.8 μm. The dual-layer analytical modeling approach introduced in this study presents a versatile technique applicable to enhancing the design and control of machine tool thermal characteristics, holding significant potential for advancing the stability of machine tools thermal accuracy. [Display omitted] [ABSTRACT FROM AUTHOR]

Matrix completion is about recovering a matrix from its partial revealed entries, and it can often be achieved by exploiting the inherent simplicity or low dimensional structure of the target matrix. For instance, a typical notion of matrix simplicity is low rank. In this paper we study matrix completion based on another low dimensional structure, namely the low rank Hankel structure in the Fourier domain. It is shown that matrices with this structure can be exactly recovered by solving a convex optimization program provided the sampling complexity is nearly optimal. Empirical results are also presented to justify the effectiveness of the convex method. [ABSTRACT FROM AUTHOR]

For linear and nonlinear systems arising from the discretization of PDEs, multiplicative Schwarz preconditioners can be defined based on subsets of the unknowns that derive from domain decomposition, field splitting, or other collections of conveniently solved subproblems, and are well established theoretically for nonoverlapping subsets. For overlapping subsets, establishing the equivalence of the preconditioned and original iterations is less trivial. We derive herein an explicit formulation for a variety of multiplicative Schwarz preconditioners including overlaps representative of interfacial and bulk coupling in multiphysics systems, thus extending theoretical support for the nonlinear multiplicative Schwarz preconditioned inexact Newton (MSPIN) algorithm to these classes. For nonlinear multiplicative Schwarz preconditioners with overlaps, we illustrate the performance through numerical experiments involving applications such as a shocked duct flow and a natural convection cavity flow. We begin with a broad introduction to nonlinear preconditioning to set the context for those new to the technique. • New theory is provided for multiplicative Schwarz preconditioning for partitions typical of interface or bulk coupling in multiphysics problems. • Effects of subdomain and field overlapping on the convergence of the MSPIN nonlinear preconditioner are illustrated with numerical examples. • Left and right sided, additive and multiplicative, nonoverlapping and overlapping, linear and nonlinear Schwarz preconditioners are compared. [ABSTRACT FROM AUTHOR]

Error compensation is one of effective and economical means to improve the machining accuracy of machine tools. The measurement accuracy of kinematic errors has great impact on the accuracy of machine tool error modeling. Some measurement errors are inevitably generated due to the distortion of the slide table and the limit of local measuring stroke. To solve these problems, an improved machine tool volumetric error compensation method is proposed in this paper, based on linear and squareness error correction method. The linear errors, including position errors and straightness errors, are corrected by considering the distance effect between optical mirror groups and the surface of worktable. The squareness errors are corrected through modifying local squareness errors measured with double ball bar to global squareness errors, with the aid of straightness errors measured with multi-laser calibrator. Then volumetric errors are obtained based on multi-body system theory, and volumetric diagonal errors are measured with laser interferometer. It is illustrated that the bidirectional systematic deviation of positioning of four volumetric diagonals reduced about 81.3%, 35.2%, 29.2%, and 4.5% respectively by using this improved machine tool volumetric error compensation method, and it is of obvious advantages in contrast with traditional compensation method with direct measurement data. The improved error compensation method proposed in this paper has universal applicability and has great significance on machine tool accuracy improvement. [ABSTRACT FROM AUTHOR]

Volumetric accuracy is susceptible to thermal gradient caused by internal heat source (IHS) and external heat source (EHS). A temperature-structure multi-step calculation method is presented to investigate the influences of EHSs on volumetric thermal errors of precision machine tools. The temperature and structure of the machine tool are simulated first, and then, the volumetric thermal errors are calculated using multi-body theory method. Simulations are completed to study the effects of different EHSs on a machine tool, and series of validating experiments are carried out to verify the modeling method. The test results in specific position and working condition revealed that EHSs contribute 53, 21, and 68% of thermal deviations in X, Y, and Z directions individually. It is illustrated that the EHS is an important factor affecting the volumetric accuracy of precision machine tools. The methods provided in this paper are valuable for machine tool designers to evaluate the EHS effects on volumetric thermal errors during designing process; furthermore, some insulating measures are suggested to improve the accuracy and accuracy stability of precision machine tools by reducing the EHS influences. [ABSTRACT FROM AUTHOR]

Thermal error is one of the primary factors affecting the machining accuracy of precision machining tools. Therefore, it is important to study the transient thermal characteristics of machine tools and the thermal-error control strategies. Thus far, a transient analytical modelling method for characterising the thermal characteristics of machine tools was proposed and an active error control strategy was provided. First, temperature-field modelling was conducted using an analytical method based on the Fourier series method and partial differential equations of heat conduction. Second, using the derived temperature field, the thermal deformation field was calculated based on finite element theory. Subsequently, the continuous real-time effect of the thermal power per unit heat source on the temperature and deformation fields of precision machine tools was studied. The proposed analytical modelling method not only predicts the machine tool heat deformation based on the working conditions of the heat source, but also matches the thermal control source power with the demand of the machine tool heat deformation. The optimal real-time power of the thermal control source is dynamically iterated and matched, such that the thermal deformation caused by the heat and thermal control sources can be balanced in real time at the displacement control point. Finally, the volumetric thermal error was actively controlled by adjusting the temperature field of the machine tool. The simulated and experimental results indicate that the transient analytical model can accurately predict the real-time thermal characteristics of the machine tool and that the real-time active thermal control method can effectively reduce volumetric thermal errors. Using active thermal control, the squareness error in the YZ-plane was reduced by approximately 45%, the spindle thermal elongation was reduced from 23 μm to 7 μm, and the volumetric thermal error in the X, Y, and Z directions were reduced by approximately 16, 14, and 17 μm, respectively. [Display omitted] • Analytical modelling method for transient thermal characterizing of machine tool structural components and spindle is proposed. • The continuous real-time effect of the unit thermal power of the heat source on the temperature and deformation fields of precision machine tools is revealed using the analytical method. • Real-time thermal power matching strategy of thermal control sources to reduce volumetric thermal error is presented. [ABSTRACT FROM AUTHOR]

Dynamic stiffness and damping of the headstock, which is a critical component of precision horizontal machining center, are two main factors that influence machining accuracy and surface finish quality. Constrained Layer Damping (CLD) structure is proved to be effective in raising damping capacity for the thin plate and shell structures. In this paper, one kind of high damping material is utilized on the headstock to improve damping capacity. The dynamic characteristic of the hybrid headstock is investigated analytically and experimentally. The results demonstrate that the resonant response amplitudes of the headstock with damping material can decrease significantly compared to original cast structure. To obtain the optimal configuration of damping material, a topology optimization method based on the Evolutionary Structural Optimization (ESO) is implemented. Modal Strain Energy (MSE) method is employed to analyze the damping and to derive the sensitivity of the modal loss factor. The optimization results indicate that the added weight of damping material decreases by 50%; meanwhile the first two orders of modal loss factor decrease by less than 23.5% compared to the original structure. [ABSTRACT FROM AUTHOR]

Modeling method investigation about spindle thermal errors is significant for spindle thermal optimization in design phase. To accurately analyze the thermal errors of motorized spindle unit, this paper assumes approximately that 1) spindle linear thermal error on axial direction is ascribed to shaft thermal elongation for its heat transfer from bearings, and 2) spindle linear thermal errors on radial directions and angular thermal errors are attributed to thermal variations of bearing relative ring displacements. Based on prerequisites, an analytical modeling method is developed to analyze these spindle thermal errors. Firstly, thermal-mechanical models of rotating ring geometry and interference assembled rotating ring geometries are established, for thermal variation modeling of relative ring displacements of short cylindrical roller bearing and angular contact ball bearing. Secondly, these thermal variation models are associated with heat-fluid-solid coupling FE (finite element) simulation technique, to model spindle linear thermal errors on radial/axial directions and angular thermal errors by the analytical simulation method. Consequently, verification experiments clarify that the presented method is accurate for spindle thermal errors modeling, and can be effectively applied into the design and development phases of motorized spindle units. [ABSTRACT FROM AUTHOR]

A reduced graphene oxide (rGO) supported magnetite nanoparticle (nFe 3 O 4 ) composite (nFe 3 O 4 /rGO) was synthesized and shown for the first time to be an efficient persulfate activator to generate SO 4 − for trichloroethylene (TCE) degradation. The degradation efficiency of TCE (0.15 mmol L −1 ) was 98.6% within 5 min in the presence of 6.94 g L −1 nFe 3 O 4 /rGO with an optimum mass ratio of 1:4 and persulfate concentration of 3.0 mmol L −1 . By dispersing nFe 3 O 4 on the rGO surface, nanoparticle agglomeration was prevented and the aggregation of the rGO sheets was disrupted. Both the redox effect coupled in nFe 3 O 4 and the electron transfer by functional groups containing oxygen on the surface of rGO enhanced the SO 4 − generation. Given the identified free radical species and the characterization of the nFe 3 O 4 /rGO, a persulfate activation mechanism by nFe 3 O 4 /rGO for the degradation of TCE was interpreted. [ABSTRACT FROM AUTHOR]

The milling stability of thin-walled component is an important problem in the aviation manufacturing industry. The milling stability is influenced by both deflection characteristic and dynamic characteristic of workpiece. Moreover, in the material removal, the deflection and dynamic characteristics of workpiece are time-variant on the change of machining positions. Thus, the milling stability is also time-variant. In order to investigate the time variation of deflection and dynamic characteristics of workpiece, a new computational model was established in this paper. Based on the influences of the deflection and the dynamic characteristics of workpiece, a new stability lobes diagram which can show different stability domains and chatter domains in different process positions was obtained. Experimental testing has been conducted to validate the established new model. [ABSTRACT FROM AUTHOR]

This paper presents an efficient algorithmic implementation of the iterative minimization formulation (IMF) for fast local search of transition state on potential energy surface. The IMF is a second order iterative scheme providing a general and rigorous description for the eigenvector-following (min-mode following) methodology. We offer a unified interpretation in numerics via the IMF for existing eigenvector-following methods, such as the gentlest ascent dynamics, the dimer method and many other variants. We then propose our new algorithm based on the IMF. The main feature of our algorithm is that the translation step is replaced by solving an optimization subproblem associated with an auxiliary objective function which is constructed from the min-mode information. We show that using an efficient scheme for the inexact solver and enforcing an adaptive stopping criterion for this subproblem, the overall computational cost will be effectively reduced and a super-linear rate between the accuracy and the computational cost can be achieved. A series of numerical tests demonstrate the significant improvement in the computational efficiency for the new algorithm. [ABSTRACT FROM AUTHOR]

The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. [ABSTRACT FROM AUTHOR]

Hydrostatic guideways are widely applied into precision and ultra-precision machine tools. Meanwhile, the oil film heat transfer causes thermal disturbance to the machine accuracy. Therefore, it is necessary to study the mechanism of the oil film heat transfer and the heat-transfer-reducing method to improve the machine accuracy. This paper describes a comprehensive thermal finite element (FE) simulation modeling method for the hydrostatic machine feed platform to study methods of reducing machine thermal errors. First of all, the generating heat power of viscous hydraulic oil flowing between parallel planes is calculated based on the Bernoulli equation. This calculation is then employed for the simulation load calculations for the closed hydrostatic guideways, which is adopted by the hydrostatic machine feed platform. Especially, in these load calculations, the changing of oil film thickness (resulted from external loads) and the changing of oil dynamic viscosity (influenced by its temperature) are taken into account. Based on these loads, thermal FE simulation modeling of the hydrostatic machine feed platform is completed to predict and analyze its thermal characteristics. The reliability of this simulation modeling method is verified by experiments. The studies demonstrate that the hydrostatic machine thermal error degree is determined by the oil film heat transfer scale, and this scale is mainly influenced by the relative oil supply temperature to ambient temperature (quantitative comparison of oil supply temperature and ambient temperature). Furthermore, the reduction of the absolute value of this relative oil supply temperature can reduce the oil film heat transfer scale and improve the machine accuracy. [ABSTRACT FROM AUTHOR]

Inverse design is a promising approach in the realm of material science for finding structures with desired property. We developed a new package with novel algorithm for inverse design named as IM 2 ODE (inverse design of Materials by Multi-Objective Differential Evolution). The target properties of concern include the optical and electronic-structure properties of semiconductors, hardness of crystals, etc. IM 2 ODE can easily predict the atomic configurations with desired properties for three dimensional structure, interface and cluster, even complex defect in solid. Tests have been run on multiple systems and it has been proved that IM 2 ODE is highly efficient and reliable, which can be applied widely. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a general and systematic approach for geometric error modeling of machine tools due to the geometric errors arising from manufacturing and assembly. The approach can be implemented in three steps: (1) development of a linear map between the pose error twist and source errors within machine tool kinematic chains using homogeneous transformation matrix method; (2) formulation of a linear map between the pose error twist and the error intensities of a machine tool; (3) combination of these two models for error separation. The merit of this approach lies in that it enables the source errors affecting the compensatable and uncompensatable pose accuracy of the machine tool to be explicitly separated, thereby providing designers and/or field engineers with an informative guideline for the accuracy improvement by suitable measures, i.e. component tolerancing in design, manufacturing and assembly processes, and error compensation. Two typical multi-axis machine tools are taken as examples to illustrate the generality and effectiveness of this approach. [Copyright &y& Elsevier]

Background A simplified model not requiring a clinic visit is important for cardiovascular prevention. We compared such a model, with one requiring clinical measurements for prediction of ischemic stroke. Methods Five population-based Finnish cohorts comprising 14 296 men and 16 065 women aged 25-64 years were randomly recruited from 1982, and followed up using the national registers until the end of the 2007. The final Cox model included age, prior history of diabetes and hypertension, happy marriage, capability to walk 500 m (self-estimate), regular exercise, vegetable/fruit intake, smoking, body mass index, and systolic blood pressure; the layperson-oriented model was developed by taking blood pressure away from the final model. Results Four hundred sixty-nine men and 371 women developed ischemic stroke events. The area under the receiver operating characteristic curve (95% confidence interval) for 10 years incidence of ischemic stroke was 0·817 (0·791-0·843) and 0·813 (0·787-0·839) for the model with and without systolic blood pressure in men and 0·815 (0·782-0·848) and 0·812 (0·779-0·844), respectively, in women ( P > 0·10). The predicted 10-year events rate matched well with the observed one across deciles of the predicted risk in men (χ2 = 11·57, 9df, P = 0·239) and in women (χ2 = 11·18, P = 0·263). The overall net reclassification improvement after adding blood pressure was 8·8% ( P = 0·016) in men and 3·2% ( P = 0·234) in women. The predicted 10-year risk of the ischemic stroke based on global vascular event models that includes coronary heart diseases did not match well with the observed stroke risk. Conclusions The layperson model performed as well as the clinical-based one. [ABSTRACT FROM AUTHOR]

Generally, the accuracy stability of a precision motorized spindle unit is influenced by its structural thermal balance behaviors (power matching degree of spindle structural heat generation–dissipations). For the accurate analysis of this spindle heat transfer behaviors based on temperature detections, this paper describes a method constructed with the numerical simulation technology and a proposed genetic algorithm-extreme learning machine (GA-ELM) algorithm. Firstly, the heat–fluid–solid coupling FE transient model is established to simulate spindle thermal behaviors, determinations of its thermal loads/boundary conditions are initially based on empirical calculations. Secondly, according to spindle temperature detections, these initial values are applied to thermal simulations and corrected by GA to make simulated spindle temperatures gradually approach detections. Specially, ELM is adopted to estimate the functional relationships from the parent population to the child population generated by genetic operators with increasing fitness values, and the trained ELM model is utilized to ensure the GA faster convergence. Eventually, based on the corrected thermal load/boundary condition values and simulation results, the time-varying power matching conditions of spindle structural heat generation–dissipation are analyzed. This study provides a theoretical basis for the optimization and promotion of spindle structural design and coolant control strategy. [ABSTRACT FROM AUTHOR]

The projection method based on the Schauder basis expansion for solving the Fredholm integral equation of the second kind is investigated. (1) It is shown that any given finite linearly independent function set in Lp[0, 1] can be extended as a Schauder basis. The truncation of the dual Schauder bases is then used to form the projection in approximating the kernel. (2) With the finite rank approximation, the use of the Sherman-Morrison-Woodbury formula achieves efficient implementation. The computation is successive when dimension of projection space increases. Numerical experiments demonstrate the robustness of the Schauder basis expansion. [ABSTRACT FROM AUTHOR]

Abstract: The current study aimed to evaluate whether individuals with fasting plasma glucose (FPG) of 5.6–6.0mmol/l has a similar risk profiles for diabetes or impaired glucose tolerance (IGT) to those with FPG of 6.1–6.9mmol/l. A community-based cross-sectional survey in Chinese adults (20–74 years) was conducted during April–July in 2002. Participants without a prior history of diabetes underwent a standardized 2-h 75g oral glucose tolerance test. Positive likelihood ratios were calculated to estimate the odds of having diabetes or IGT for subjects with different FPG levels. Among 1856 participants, prevalence of IFG increased from 12.4 to 28.2% with the cut-off value of FPG lowered from 6.1 to 5.6mmol/l. Individuals with FPG of 6.1–6.9mmol/l were more obese and insulin resistant than those with FPG of 5.6–6.0mmol/l. The positive likelihood ratio for diabetes and IGT were 1.83 (1.28–2.61) and 2.60 (1.96–3.44) in subjects with FPG of 6.1–6.9mmol/l, and 0.54 (0.30–0.95) and 1.47 (1.11–1.95) for those with FPG of 5.6–6.0mmol/l, respectively. In conclusion, the likelihood of diabetes and IGT was lower in subjects with FPG of 5.6–6.0mmol/l than in those with FPG of 6.1–6.9mmol/l. The clinical and social implication of labelling more individuals with impaired fasting glucose needs to be further studied. [Copyright &y& Elsevier]

The clustering of metabolic and pathophysiological cardiovascular risk factors has long been recognized but it was Reaven who popularized the syndrome in the Banting lecture of 1988. Since 1999, several major international or national organizations proposed their own definitions for the syndrome, named the metabolic syndrome. The prevalence of the metabolic syndrome varies according to definition, ethnicity and gender. The prevalence is under 20% among Chinese and Korean people but over 50% among Maori and Pacific Islanders in New Zealand. People with the metabolic syndrome have 50–60% higher cardiovascular risk than those without. The absolute cardiovascular risk of the metabolic syndrome, however, is not necessarily higher than those of its individual components. The pathogenesis underlying the clustering of cardiovascular risk factors remains unclear. Factors including genetic disposition, obesity, insulin resistance and inflammation have been suggested as being involved. Since the metabolic syndrome is multifactorial in origin, strategies for reducing cardiovascular risk in individuals with the metabolic syndrome involve the management of multiple risks. Lifestyle changes are an effective first-line management; pharmacological interventions for hypertension, diabetes and dyslipidaemia are in accordance with established guidelines. Pharmacological and surgical therapies for obesity are effective in selected patients. In this article we discuss the definitions, prevalence, pathogenesis and management of the metabolic syndrome in relation to cardiovascular risk. [ABSTRACT FROM AUTHOR]

Temperature variations in the machine tool structural components may lead to relative pose variations between the tool tip and the workpiece. Different thermal layouts may lead to various temperature distributions and generate various thermal deformations. Thermal symmetric design is often used to complete thermal balancing of machine tools. Studies on theoretical methods to guide the layout design of the heat sources (HS) and cooling sources (CS) in machine tools are insufficient. To address this problem, a novel analytical approach for characterising the equivalent cuboid thermal response of machine tool structural components is presented in this paper. The proposed analytical modelling method can realise analytical temperature field modelling with Green's function, calculating the equivalent thermal moment with Reissner's theory, and matching the thermal power-deformation mapping coefficient (TPDMC) using the finite element method (FEM). The explicit and correlative formulation between the thermal power of the HSs and CSs and the guideway thermal deviations is deduced. Furthermore, the layout principles of the CSs are presented according to the maximum efficiency of the thermal moment and the characterisation matching of the TPDMC curves. Afterwards, power matching of the CS is obtained with the aid of the minimum deformation principles of the key positions. Simulated and experimental results illustrated that the proposed method can be used to rapidly and accurately analyse the temperature and thermal deformation responses of the machine tool, as well as to provide a thermal balancing strategy according to specific thermal conditions. The analytical approach proposed in this paper is a general method suitable for the thermal balancing design of machine tools, and it is of great value for improving the thermally induced accuracy stability of machine tools. [Display omitted] • Analytical modelling method for thermal characterizing of machine tool structural components is presented. • Effects of heat sources powers on temperature and deformation are theoretically investigated. • Layout principle of heat/cooling sources is summarised. • Thermal balancing strategy to reduce thermal deformation is developed. [ABSTRACT FROM AUTHOR]

With the increasing demand for innovative electronic products, LED transparent screens are gradually entering the public eye. Polyimide (PI) materials combine high temperature resistance and high transparency, which can be used to prepare flexible copper-clad laminate substrates. The physical and chemical properties of PI materials differ from copper, such as their thermal expansion coefficients (CTEs), surface energy, etc. These differences affect the formation and stability of the interface between copper and PI films, resulting in a short life for LED transparent screens. To enhance PI-copper interfacial adhesion, aminopropyl-terminated polydimethylsiloxane (PDMS) can be used to increase the adhesive ability. Two diamine monomers with a trifluoromethyl structure and a sulfone group structure were selected in this research. Bisphenol type A diether dianhydride is a dianhydride monomer. All three of the above monomers have non−coplanar structures and flexible structural units. The adhesion and optical properties can be improved between the interface of the synthesized PI films and copper foil. PI films containing PDMS 0, 1, 3, and 5 wt% were analyzed using UV spectroscopy. The transmittance of the PI-1/3%, PI-1/5%, PI-2/3%, and PI-2/5% films were all more than 80% at 450 nm. Meanwhile, the Td 5% and Td 10% heat loss and Tg temperatures decreased gradually with the increase in PDMS. The peel adhesion of PI-copper foil was measured using a 180° peel assay. The effect of PDMS addition on peel adhesion was analyzed. PIs-3% films had the greatest peeling intensities of 0.98 N/mm and 0.85 N/mm. [ABSTRACT FROM AUTHOR]

Polymer materials with a low dielectric constant and low dielectric loss have the potential to be applied to high-frequency signal transmissions, such as mobile phone antennas and millimeter wave radars. Two types of diamines, 4,4′-diamino-p-tetraphenyl (DPT) and crown ether diamine (CED), were prepared for ternary copolymerization with BPDA in this study. Cross-links with molecular chains were formed, increasing molecular chain distance by utilizing rings of CED. The MPI films exhibit a good thermal performance with the increase in CED addition, with Tg > 380 °C and CTE from −4 × 10−6 K−1 to 5 × 10−6 K−1. The Young's modulus can reach 8.6 GPa, and the tensile strength is above 200 MPa when 5% and 7% CED are introduced. These MPI films exhibit good mechanical performances. The dielectric constant of PI−10% film can go as low as 3.17. Meanwhile, the relationship between dielectric properties and molecular structure has been demonstrated by Molecular Simulation (MS). PI molecules are separated by low dielectric groups, resulting in a decrease in the dielectric constant. [ABSTRACT FROM AUTHOR]

This paper is concerned with the relative sensitivity of the individual stationary probabilities of an irreducible Markov chain to small relative blockwise perturbations of the transition matrix. It is shown that this sensitivity depends on some quantities related to the stochastic complements of diagonal blocks of the transition matrix. For nearly uncoupled and nearly transient Markov chains, the stationary probabilities are sensitive to general perturbations in the relative sense. However, they are insensitive to small blockwise relative perturbations.

Transition states are fundamental to understanding the reaction dynamics qualitatively in chemical physics. To date various methods of first principle location of the transition states have been developed. In the absence of the knowledge of the final structure, the softest-mode following method climbs up to a transition state without calculating the Hessian matrix. One weakness of this kind of approaches is that the number of rotations to determine the softest mode is usually unpredictable. In this paper, we propose a locally optimal search direction finding algorithm, namely LOR, which is an extension of the traditional conjugate gradient method without additional calculations of the forces. We also show that the translation of forces improves the numerical stability. Experiments for the Baker test system show that the proposed algorithm is much faster than the original dimer conjugate gradient method. [ABSTRACT FROM AUTHOR]

The current study aims to determine the secular trend of prevalence of type 2 diabetes and prediabetes and risk factors for diabetes from 2002 to 2009. We conducted 3 population-based surveys for diabetes in individuals aged 35-74 years in Qingdao in 2002, 2006 and 2009, respectively, with random-sampling approach. The sample size was 1792, 4549 and 4310 in 2002, 2006 and 2009, respectively. We performed a questionnaire-based survey to collect general information. All participants underwent standardized 2-h 75-g oral glucose tolerance tests (OGTTs). The 1999 WHO diagnostic criteria for diabetes and prediabetes was applied. Age-standardized prevalence of diabetes was calculated. Multiple non-conditional logistic regression were applied to analyze the risk factors for diabetes, taking diabetes as the dependent variable. In 2002, the age-standardized prevalence of diabetes was 12.32%, the corresponding prevalence was 16.57% and 18.01%, respectively, in 2006 and 2009. The prevalence of diabetes increased from 2002 to 2009 (p<0.05). The age-standardized prevalence of prediabetes in 2002, 2006 and 2009 was 16.18%, 24.56% and 28.25%, respectively (P for trend < 0.05). Multiple non-conditional logistic regression analysis showed that the risk factor for diabetes were age, waist, systolic blood pressure (SBP), total cholesterol, triglyceride, and family history of diabetes in both 2002 and 2006. The risk factor for diabetes included age, waist, SBP, total cholesterol, triglyceride, and family history of diabetes in 2009. High density lipoprotein cholesterol was negatively associated with increased risk for diabetes. The prevalence of diabetes and prediabetes in Qingdao increases from 2002 to 2009, implying an epidemic of diabetes in this area. The common risk factors contributing to the increasing trend are age, waist, SBP, total cholesterol, triglyceride, and family history of diabetes. Disclosure: L. Zhang: None. W. Gao: None. N. Wang: None. J. Wang: None. X. Yin: None. Y. Zhu: None. Y. Dong: None. [ABSTRACT FROM AUTHOR]

For thermal perception and control onto spindle bearings without spindle/bearing structural modifications for built-in thermal sensors, this paper proposes a thermal simulation speculation-based active coolant control strategy onto spindle bearings, for spindle accuracy guarantee. Firstly, numerical simulation technology is adopted to construct thermal collection of spindle bearings influenced by coolants. Secondly, this collection is utilized as the basis for ELM speculation modeling for bearing thermal behaviors. Eventually, the previous active coolant strategy is modified to be equipped with the model above for the speculation perception (according to the detectable spindle working parameters) and active control realization onto thermal behaviors of spindle bearings. It is verified by experiment and simulation that the thermal simulation speculation-based active coolant strategy is more advantageous than the previous strategy, in thermal stabilization and accuracy guarantee of motorized spindle unit. Besides, the power ratio between coolant heat dissipation and bearing heat generation is suggested to be 1.15:1 for a sufficient thermal balance of spindle bearings, which brings the design guidance onto cooling capacity/strategy of recirculation cooling equipment for motorized spindle unit. [ABSTRACT FROM AUTHOR]

Angular contact ball bearings have been widely utilized in machine tool spindles and bearing preload has a great influence on the performance of the spindle. The variable preload control technology, including variable pressure preload and variable position preload, is the key technology for intelligent spindle. In order to implement variable pressure/position preload control, the control method and control performance of the variable pressure/position preload spindle-bearing system by using piezoelectric actuators under close-loop control are systematically studied in this paper. A test rig of variable pressure/position spindle-bearing system is developed, and the piezoelectric actuators are adopted to realized preload or axial clearance close-loop control automatically. Both variable pressure preload and variable position preload can be realized on the test rig. The mechanical model of the variable pressure/position preload spindle-bearing system by using piezoelectric actuators is established. Then stiffness model considering the external axial load in static state, and axial displacement as well as operational preload model in rotational state of the spindle-bearing system with piezoelectric actuators in variable pressure preload and variable position preload are proposed and simulated. The design method of the preload mechanism by using piezoelectric actuators is presented. PI controller is employed to regulate the preload or axial clearance of the spindle-bearing system in real-time. A series of experiments are implemented to verify the validity of the variable preload control method and the superiority of the variable pressure/position preload control performance by using piezoelectric actuators. The results show that the variable pressure/position preload spindle-bearing system by using piezoelectric actuators shows excellent performance in controlling preload or axial clearance. The static and dynamic characteristics as well as the operational behaviors of the spindle-bearing system under variable position preload and variable pressure preload are verified by experiments. It is illustrated that the stiffness and the first order natural frequency will be changed with the change of preload methods and preload values. The operational behaviors vary greatly with the preload method, initial preload (negative axial clearance) and rotational speed. The variable preload control method plays a great important role on the performance of spindle-bearing system. Furthermore, this paper provides a foundation for the future research of preloading intelligent control technology as well as investigating the thermal-mechanical-dynamic characteristic of high speed spindle-bearing system. [ABSTRACT FROM AUTHOR]

Conventional three-probe method of artifact roundness and spindle error measurements is subjected to the trouble of harmonic suppression, which is also mathematically complicated due to complex transformation processing. A novel three-probe method by solving system of multivariable equation (SSME) method is presented in this paper. The presented method simplifies the mathematical processing and has good robustness to the measurement angles which are difficult for conventional three-probe method. This paper gives mathematical models, detailed theoretical derivations, and numerical simulations. Selection criteria of the optimal measurement angle combinations can be determined in accordance with rank and condition number of the coefficient matrix. Then, to validate the feasibility and repeatability of the proposed method, experimental measurements are performed on a vertical machine tool spindle by using nanometer-resolution capacitive displacement sensors, high-precision indexing table, and professional data acquisition system. Artifact roundness error and spindle radial error are tested to validate separation accuracy by specialized instruments. The comparisons demonstrate that the proposed method has good feasibility and repeatability (the maximum deviations of spindle error and roundness error are 9.62 and 3.86%). SSME method, due to its simplicity in computation and the uniqueness of the solution provided, is more suitable to separate spindle radial error from the artifact roundness error. [ABSTRACT FROM AUTHOR]

Error compensation is an effective method to guarantee the machining accuracy of machine tools. This paper proposes a method for geometric error identification and compensation of CNC machine tools based on volumetric diagonal error measurements. A geometric error model for CNC machine tools was established. Thereafter, the error measurement principle of the laser tracker was established. Based on this characteristic, error identification equations used to describe the position-dependent geometric errors were derived based on polynomials. A regularisation method was then selected to identify geometric error parameters. The identified geometric errors could be substituted in the space compensation module for error compensation. This paper takes a horizontal three-axis machining centre as an example to illustrate the proposed method. Results of the experiment reveal that the error identification and compensation method is convenient and effective in reducing volumetric diagonal errors. Moreover, the final volumetric diagonal positioning error with compensation was controlled at approximately 20 μm. [ABSTRACT FROM AUTHOR]

Complicated skin and soft tissue infections (cSSTI) are some of the most commonly treated infections in hospitals, and place heavy economic burdens on patients and society. Here we report the findings from an analysis of cSSTI based on a retrospective study which was conducted within the Chinese inpatient population. We focused our research on the analysis of the patient population, antibiotic treatment, clinical outcome and economic burden. The study population comprised 527 selected patients hospitalized between 2008 and 2013. Among the hospitalizations with microbiological diagnoses, 61.41% (n = 113) were diagnosed as infected with Gram-positive bacteria, while 46.20% (n = 85) were infected with Gram-negative bacteria. The most commonly found Gram-positive bacteria was Staphylococcus aureus (40.76%, n = 75), and the most common Gram-negative bacteria was Escherichia coli (14.13%, n = 26). About 20% of the Staphylococcus aureus were methicillin-resistant. The resistance rate of isolated Staphylococcus aureus or Escherichia coli to penicillin was around 90%; in contrast, the resistance rate to vancomycin, linezolid or imipenem was low (<20%). A large percentage of patients were treated with cephalosporins and fluoroquinolones, while vancomycin and imipenem were also included to treat drug-resistant pathogens. Over half of the hospitalizations (58.43%, n = 336) experienced treatment modifications. The cost to patients with antibiotic modifications was relatively higher than to those without. In conclusion, our study offers an analysis of the disease characteristics, microbiological diagnoses, treatment patterns and clinical outcomes of cSSTI in four hospitals in Guangdong Province, and sheds lights on the current clinical management of cSSTI in China. [ABSTRACT FROM AUTHOR]

• The relationship between repeatability error and data confidence is established. • The spatial error prediction model based on confidence weighting is derived. • The simulation process based on statistics is designed. • A spatial error measurement scheme based on data fusion is proposed. • The accuracy and reliability are verified on a horizontal machining center prototype. A spatial error prediction method for precision machine tools considering the influence of repeatability errors is proposed in this paper. Firstly, the reciprocal of the repeatability error is used to evaluate the measurement data confidence to distinguish the difference of useful information contained in the measurement data of different positions. Secondly, the proposed confidence index is used to weight the measured values of PDGEs at different positions, so that the data containing more useful information can play a full role in the error prediction, and the predicted error is substituted into the error model to predict the spatial error. Then, the computer simulation based on statistical analysis is designed, the PDGEs and spatial error prediction accuracy of the weighted algorithm are verified by simulation. Finally, a multi-instrument fusion spatial error measurement scheme is proposed, and the accuracy and reliability of the model are verified on a horizontal machining center prototype. [ABSTRACT FROM AUTHOR]

The support point layout has an important influence on the working performance of the machine tool, when the material, manufacturing process, and internal structure of machine bed are given. In order to ensure the performance, stability, and anti-interference of precise machine tool, this paper presents an optimized design method of 3-point support for T-shaped bed of precision horizontal machining center. This article first establishes the statics model of the T-shaped bed and analyzes grillage beam model used to characterize the main static deformation trend of the bed based on the singular function method. After verifying the rationality of the model through simulation, the optimized 3-point support position can be obtained. Then this paper measured the deformation of the upper surface of a simple bed due to gravity. The deviation between the experimental results and the simulation results is less than 20%, which verifies the reliability of the simulation and theoretical results. Based on the ISIGHT multidisciplinary optimization platform, this paper completes the multi-objective optimization of the support point layout of the bed, and the optimization results prove the accuracy of the theoretical model. This paper takes the bed of M800H precision horizontal machining center as an example to illustrate the application process of the proposed method. Then, the optimization effect of the bed and the static characteristics of the whole machine by simulation are compared. The maximum deformation of the bed has reduced by 27.1%. In the whole machine status, the deformation of the spindle end has reduced by 50.8%, and the maximum deformation of the workpiece end has reduced by 50.0%. Finally, a verification experiment of the relative position deviation between the end of the spindle and the worktable on the complete machine was carried out. The error of the simulation and experiment results was about 22%, which proves the effect of the optimization of the support position. [ABSTRACT FROM AUTHOR]

This paper presents the dynamic modeling and controller design of an XY positioning stage for semiconductor packaging. The XY stage is directly driven by two linear voice coil motors, and motion decoupling between the X and Y axes is realized through a novel flexible decoupling mechanism based on flexure hinges and preloaded spring. Through bond graph method, the dynamic models of X- and Y-axes servomechanisms are established, respectively, and the state space equations are derived. A control methodology is proposed based on force compensations and the performance of the XY stage is investigated by simulations and experimental tests. The results show that the XY stage has good performance. When the reference displacements are defined as 2 mm, the settling time of the X-axis movement is 64 ms, and the overshoot is 0.7%. Y-axis settling time is 62 ms, and the overshoot is 0.8%. X-axis positioning accuracy is 1.85 μm and the repeatability is 0.95 μm. Y-axis positioning accuracy and repeatability are 1.75 μm and 0.9 μm, respectively. In addition, the stage can track linear, circular and complex trajectories very well. [ABSTRACT FROM AUTHOR]

Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15 mmol L −1 ) was 99.4% in the presence of nZVI/BC (4.5 mmol L −1 , nZVI to BC mass ratio was 1:5) and persulfate (4.5 mmol L −1 ) within 5 min, which was significantly higher than that (56.6%) in nZVI–persulfate system under the same conditions. Owing to large specific surface area and oxygen-containing functional groups of BC, nZVI/BC enhanced the SO 4 - generation and accelerated TCE degradation. On the basis of the characterization and analysis data, possible activation mechanisms of the Fe 2+ /Fe 3+ (Fe(II)/Fe(III)) redox action and the electron-transfer mediator of the BC oxygen functional groups promoting the generation of SO 4 - in nZVI/BC–persulfate system were clarified. [ABSTRACT FROM AUTHOR]

Being a critical factor affecting the motion accuracy of precision machine tools, structural thermal elongation of precision ball screw unit is generally caused by the comprehensive influence from heat generations of screw-nut pair/bearings and time-varying ambient temperature. To resist 2 thermal disturbances above to guarantee precisely the original length of screw shaft, an active coolant control strategy is proposed in this paper. This strategy is based on a premise hypothesis: For the slender and long tubular structure of screw shaft, the screw shaft temperature is approximately equal to its recirculating coolant temperature. The reason is that the intensive forced coolant convection is capable of eliminating screw shaft temperature rises caused by friction heat generations and ambient air convections. Based on this premise, screw coolant temperature can be consistently controlled by an active strategy, further to correct the thermal elongation of screw shaft. It can be experimentally verified that the thermal variations of machine positioning accuracy caused by the active coolant control strategy are not more than 10 μm, which are lower than traditional strategy. Besides, based on detected structural temperatures of precision ball screw unit, the theoretical model above is further proved to be reliable by FE simulation method. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To investigate the association of fresh vegetable consumption with the risk of diabetes in a Chinese population. Methods: Data from 2386 individuals aged 35–74 years who participated in a population-based cross sectional diabetes survey in Qingdao, China were analyzed. Frequency of vegetable intake was obtained using a food frequency questionnaire. Diabetes was defined as self-reported diabetes or undiagnosed diabetes determined by 2-h 75g oral glucose tolerance test or fasting capillary blood glucose test. Multivariate-adjusted odds ratio (OR) for the presence (vs. the absence) of diabetes in association with the frequency of fresh vegetable intake was estimated using logistic regression analysis. Results: The OR for the presence of diabetes was 1.17 (95% CI 0.66, 2.05) in men and 0.50 (95% CI 0.33, 0.77) in women who ate fresh vegetables more than 14 times/week as compared with those who ate fresh vegetables less than 7 times/week after adjustment for age, family history of diabetes, BMI, systolic blood pressure, 24-h energy intake, physical activity and smoking and drinking. Conclusions: Consumption of fresh vegetables was associated with a low risk of having diabetes in women but not in men in this Chinese population. [Copyright &y& Elsevier]

OBJECTIVE--The study's goal was to evaluate the performance of A1C and fasting capillary blood glucose (FCG) tests as mass screening tools for diabetes and pre-diabetes, as determined by the standard oral glucose tolerance test (OGTT). RESEARCH DESIGN AND METHODS--Data from 2,332 individuals aged 35-74 years who participated in a population-based cross-sectional diabetes survey in Qingdao, China, were analyzed. A 2-h 75-g OGTT was used to diagnose diabetes. The performance of A1C and FCG was evaluated against the results of the OGTTs by using receiver operating characteristic curve (ROC) analysis. RESULTS--The prevalence of newly diagnosed diabetes and pre-diabetes (impaired fasting glucose and/or impaired glucose tolerance) was 11.9 and 29.5%, respectively. For subjects with newly diagnosed diabetes, the area under the ROC curve was 0.67 for A1C and 0.77 for FCG (P < 0.01) in men and 0.67 and 0.75 (P < 0.01) in women, whereas for pre-diabetes, these values were 0.47 and 0.64 (P < 0.001) in men and 0.51 and 0.65 (P < 0.001) in women. At the optimal A1C cutoff point of ≥5.6% for newly diagnosed diabetes, sensitivities (specificities) were 64.4% (61.6%) for men and 62.3% (63.3%) for women. CONCLUSIONS--As a screening tool for newly diagnosed diabetes and pre-diabetes, the FCG measurement performed better than A1C in this general Chinese population. [ABSTRACT FROM AUTHOR]

Biclustering (co-clustering, two-mode clustering), as one of the classical unsupervised learning methods, has been applied in many different fields in recent years. Different types of biclustering methods have been developed such as probabilistic methods, two-way clustering methods, variance minimization methods, and so on. However, few regression-based methods have been proposed to the best of our knowledge. Such methods have been applied in traditional clustering, which can improve both the computational efficiency and the clustering accuracy. In this paper, we present a penalized regression-based method for localizing the biclusters (PRbiclust). By imposing Truncated LASSO Penalty (TLP) and group TLP terms to penalize the column vectors and the row vectors in the regression model, the structure of biclusters in the data matrix is recovered. The model is formulated as an optimization problem with nonconvex penalties, and a computationally efficient algorithm is proposed to solve it. Convergence of the algorithm is proved. To extract the biclusters from the recovered data matrix, we propose a graph-based localization method. An evaluation criterion is also proposed to measure the efficiency of bicluster localization when noise entries exist. We apply the proposed method to both simulated datasets with different setups and a real dataset. Experiments show that this method can well capture the bicluster structure, and performs better than the existing works. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Serum uric acid (UA) is reported as an important marker of hypertension, coronary heart disease, and diabetes; diabetic subjects have low UA levels. The relationship between UA and fasting plasma glucose (FPG) and 2-h plasma glucose concentrations in non-diabetic subjects as well as in diabetic subjects in general population is not well known. This was investigated in a general Chinese population. Methods: A stratified, random cluster sampling method was performed to select a representative sample of general population aged 20–74 years in Qingdao in 2002. A total of 1288 men and 2344 women participated in the survey. The mean UA concentration was calculated for small glucose intervals and the trend was tested using general linear model. Results: The mean concentrations of UA were 381, 393, 371, and 345μmol/l in men with FPG of <6.1, 6.1–6.9, ≥7.0mmol/l (newly diagnosed diabetes), and in those with prior history of diabetes. They were 308, 322, 301, and 293μmol/l, respectively, in women. The UA levels declined with increasing FPG levels in individuals with newly diagnosed diabetes, with standardized coefficient of −0.26 in men and −0.20 in women, after multivariate adjustment for age, body mass index, triglycerides, and cardiovascular disease history. The relationship between 2-h glucose and UA was not as clear as that for FPG. Conclusion: Serum UA levels tended to increase with increasing FPG levels in non-diabetic individuals, but decrease in diabetic individuals. [Copyright &y& Elsevier]

Calculations of transient thermal loads/boundary conditions are crucial for accurate thermal simulations of motorized spindle unit with time-varying working parameters (such as rotation speed). By the ELM theory, this paper proposes a modeling and calculation method onto transient thermal loads/boundary conditions for spindle simulation, according to spindle temperature detections. Firstly, heat-fluid-solid coupling finite element model is established to simulate spindle thermal behaviors. Secondly, the relationship between the real-time simulated spindle temperatures and the corresponding transient thermal loads/boundary conditions are constructed by ELM method. With real-time experimental temperatures being the input vector, transient thermal loads/boundary conditions for simulation are calculated by the established ELM model. Ultimately, with the spindle operation with progressive rotation being an example, the reliability of the proposed method is verified by the agreement between simulated spindle temperatures and their detections. Furthermore, obtained transient thermal loads/boundary conditions and simulation results are utilized to analyze spindle pure heat absorption, for the guidance onto spindle coolant strategy optimization. [ABSTRACT FROM AUTHOR]

Introduction: We explored the impact of a temporary tobacco-free public policy for the 2008 Summer Olympics on the smoking prevalence and secondhand smoke exposure among the population of a co-hosting city, Qingdao, China.Methods: The Qingdao Diabetes Survey was analyzed for 2006 (n = 4599) and 2009 (n = 4680), which are survey years before and after the tobacco-free Olympics public policy period (July 2007 to January 2009). We analyzed the differences in self-reported smoking prevalence and exposure to secondhand smoke at home and/or workplace, and compared odds of smoking by survey year and of exposure to secondhand smoke among nonsmokers.Results: From 2006 to 2009, the male smoking prevalence declined from 51.4% (95% confidence interval [CI] = 49.0% to 53.9%) to 42.6% (95% CI = 40.2% to 45.1%), and the proportion of lighter smokers decreased more. Among nonsmokers, the secondhand smoke exposure rate declined from 62.2% (95% CI = 60.5% to 63.9%) to 56.8% (95% CI = 55.1% to 58.6%). Regression analyses show 34% lower odds of men smoking after Olympics (OR = 0.66, 95% CI = 0.57% to 0.77%). Rural residents and individuals who are not retired were more likely to smoke. Female nonsmokers report 17% less exposure to secondhand smoke after Olympics (OR = 0.83, 95% CI = 0.70% to 0.98%). Urban nonsmokers were more likely to be exposed than their rural counterparts.Conclusions: Smoking prevalence among men and secondhand smoke exposure among women significantly decreased in Qingdao, China, after the tobacco-free Olympics public policy period. As only the proportion of lighter smokers decreased, this may help explain why urban nonsmokers reported increased exposure. Unintended increased secondhand smoke exposure and cessation support need to be addressed in large-scale policy campaigns.Implications: Hosting the Olympic Games can help to initiate large-scale tobacco-free public policies for hosting cities. Although previous studies have demonstrated reduction in nonsmoker exposure to secondhand smoke, the impact on the hosting city's smoking prevalence or exposure rates is unclear. After the Olympic Games in Qingdao, China, smoking prevalence among men significantly decreased, mostly due to light smokers. Secondhand smoke exposure at home and/or workplace significantly decreased among female nonsmokers. Urban nonsmokers had an unintended consequence of increased secondhand smoke exposure after the tobacco-free Olympic policy period. Concurrent promotion of cessation support for heavier smokers may be needed. [ABSTRACT FROM AUTHOR]

• Measurement trajectory is extended to the whole rotation range of dual rotary axes. • The identification model is established to obtain geometric errors simultaneously. • The effectiveness of the proposed method is validated by prediction and measurement. For the rotary axes, the position-dependent geometric errors (PDGEs) and position-independent geometric errors (PIGEs) affect their rotational accuracy concurrently. Therefore, aiming at analyzing this coupling effect of geometric errors, a novel method is presented to identify the PDGEs and PIGEs of dual rotary axes simultaneously. The identification model is established based on the geometric error model and actual distances between the two retroreflectors, by which all geometric errors of two rotary axes can be obtained simultaneously. The identification results are validated by predicting volumetric errors, in which the deviations between the predicted and measured VEs are within 21.7 μm in three directions. Moreover, the root mean square error between the predicted and measured volumetric errors is 6.8 μm, which indicates that the proposed method can effectively accomplish the simultaneous identification of geometric errors. This identification method facilitates the further study of the coupling effect of PDGEs and PIGEs. [ABSTRACT FROM AUTHOR]

Motorized spindle unit is the core component of a precision CNC machine tool. Its thermal errors perform generally serious disturbance onto the accuracy and accuracy stability of precision machining. Traditionally, the effectiveness of the compensation method for spindle thermal errors is restricted by machine freedom degrees. For this problem, this paper presents an active, differentiated, and intelligent control method onto spindle thermal behaviors, to realize comprehensive and accurate suppressions onto spindle thermal errors. Firstly, the mechanism of spindle heat generation/dissipation-structural temperature-thermal deformation error is analyzed. This modeling conveys that the constantly least spindle thermal errors can be realized by differentiated and active controls onto its structural thermal behaviors. Based on this principle, besides, the active control method is developed by a combination of extreme learning machine (ELM) and genetic algorithm (GA). The aim is to realize the general applicability of this active and intelligent control algorithm, for the spindle time-varying thermal behaviors. Consequently, the contrasting experiments clarify that the proposed active and intelligent control method can suppress accurately and synchronously all kinds of spindle thermal errors. It is significantly beneficial for the improvements of the accuracy and accuracy stability of motorized spindle units. [ABSTRACT FROM AUTHOR]

Geometric accuracy is crucially important for machine tools. Identification of geometric errors, especially position-dependent geometric errors, is still a challenging issue. This paper presents a systematic and fast approach to identify the geometric error components of a precision machine tool using double ball bar (DBB). The approach can be implemented in three steps: (1) polynomial based error modeling that relates the DBB radius error directly to the geometric error parameters of machine tool; (2) spatial measurement trajectory planning with a single installation of DBB in order to avoid producing extra setup errors; (3) error identification with regularization method that can solve the ill-posed identification problem effectively. Simulations and experiments show the accuracy and effectiveness of the proposed identification approach. The results of the DBB test show that, utilizing the proposed identification method, the roundness errors of the three circular paths in xy-, yz- and xz-plane are reduced from 27.3 μm, 20.7 μm and 24.1 μm to 9.2 μm, 12.3 μm and 7.8 μm, respectively, with error compensation. [ABSTRACT FROM AUTHOR]

Aims To estimate the long-term cost-effectiveness of exenatide twice daily vs insulin glargine once daily as add-on therapy to oral antidiabetic agents ( OADs) for Chinese patients with type 2 diabetes ( T2DM). Methods The Cardiff Diabetes Model was used to simulate disease progression and estimate the long-term effects of exenatide twice daily vs insulin glargine once daily. Patient profiles and treatment effects required for the model were obtained from literature reviews (English and Chinese databases) and from a meta-analysis of 8 randomized controlled trials comparing exenatide twice daily with insulin glargine once daily add-on to OADs for T2DM in China. Medical expenditure data were collected from 639 patients with T2DM (aged ≥18 years) with and without complications incurred between January 1, 2014 and December 31, 2015 from claims databases in Shandong, China. Costs (2014 Chinese Yuan [¥]) and benefits were estimated, from the payers' perspective, over 40 years at a discount rate of 3%. A series of sensitivity analyses were performed. Results Patients on exenatide twice daily + OAD had a lower predicted incidence of most cardiovascular and hypoglycaemic events and lower total costs compared with those on insulin glargine once daily + OAD. A greater number of quality-adjusted life years (QALYs; 1.94) at a cost saving of ¥117 706 gained was associated with exenatide twice daily vs insulin glargine once daily. (i.e. cost saving of ¥60 764/ QALY) per patient. Conclusions In Chinese patients with T2DM inadequately controlled by OADs, exenatide twice daily is a cost-effective add-on therapy alternative to insulin glargine once daily, and may address the problem of an excess of medical needs resulting from weight gain and hypoglycaemia in T2DM treatment. [ABSTRACT FROM AUTHOR]