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关键词： Airfoil   Sequential Quadratic Programming   Support Vector Machine   Black Box   Numerical Simulation   Multi Objective Evolutionary Algorithms   Lagrange Multipliers   Lift Coefficient   Finite Element Analysis   Multidisciplinary Design Optimization  

摘要： To sufficiently reuse the knowledge from previous optimization efforts, a surrogate-assisted differential evolution using knowledge-transfer-based sampling (denoted as SADE-KTS) method is proposed for solving expensive black-box optimization problems. In SADE-KTS, a novel knowledge-transfer-based sampling method is integrated with the differential evolution framework to generate promising initial sample points. In this way, a least-squares support vector machine classifier is constructed based on the prior optimization knowledge database to calibrate the initial sample points adaptively, which improves the exploration performance via transferring the existed optimization efforts to the current optimization task. Moreover, the radial basis function and kriging surrogates are employed to replace the expensive simulation models for evolutionary operations, where the tailored differential evolution operators are cooperated with the sequential quadratic programming optimizer to lead the search to the global optimum efficiently. A number of numerical benchmarks are tested to illustrate the optimization capacity of SADE-KTS compared with several competitive optimization algorithms. Finally, SADE-KTS is applied to an airfoil aerodynamic knowledge-based optimization problem considering the existed optimization knowledge, which demonstrates the practicality and effectiveness of the proposed SADE-KTS in engineering practices.

关键词： orbit maneuver   orbit coverage analysis   earth observation satellite (EOS)   differential evolution algorithm   ant colony optimization  

摘要： Earth observation satellite (EOS) systems often encounter emergency observation tasks oriented to sudden disasters (e.g., earthquake, tsunami, and mud-rock flow). However, EOS systems may not be able to provide feasible coverage time windows for emergencies, which requires that an appropriately selected satellite transfers its orbit for better observation. In this context, we investigate the orbit maneuver optimization problem. First, by analyzing the orbit coverage and dynamics, we construct three models for describing the orbit maneuver optimization problem. These models, respectively, consider the response time, ground resolution, and fuel consumption as optimization objectives to satisfy diverse user requirements. Second, we employ an adaptive differential evolution (DE) integrating ant colony optimization (ACO) to solve the optimization models, which is named ACODE. In ACODE, key components (i.e., genetic operations and control parameters) of DE are formed into a directed acyclic graph and an ACO is appropriately embedded into an algorithm framework to find reasonable combinations of the components from the graph. Third, we conduct extensive experimental studies to show the superiority of ACODE. Compared with three existing algorithms (i.e., EPSDE, CSO, and SLPSO), ACODE can achieve the best performances in terms of response time, ground resolution, and fuel consumption, respectively.

关键词： Electromagnetic interference   Windings   Inductors   Magnetic separation   Capacitance   Capacitors   Passive filters   Common mode (CM)   differential mode (DM)   electromagnetic interference (EMI)   EMI choke   flexible multilayer foils (FMLFs)   full integration   function decoupling  

摘要： The emerging flexible multilayer foils (FMLFs)-based winding design has a great potential to promote the magnetic integration technique in power electronic systems. This article investigates the full integration of a single-phase electromagnetic interference (EMI) choke with well-designed FMLFs. By sharing a UU-type core and configuring the windings reasonably, all the common-mode (CM) inductance and capacitances and differential-mode (DM) inductances and capacitances can be integrated into the same core unit. Moreover, the proper terminal configuration of conductive layers can realize function-decoupling between CM and DM filtering elements, which contributes to simplifying the equivalent CM and DM models, then predigesting the parameters design procedure. Following the modeling and theoretical analysis, prototypes of the proposed and existing EMI chokes have been built for a single-phase 200-kHz SiC-mosfet inverter system. Through experimental measurements, performance comparisons have been presented to demonstrate the validity of this model.

关键词： health inequities   ecological momentary assessment   stress   alcohol craving   ADHD  

摘要： Background and Aims Black drinkers compared with white drinkers experience more alcohol-related problems. Examination of social determinants of inequities in alcohol problems is needed. The current study measured (1) associations between acute stress and alcohol craving in the naturalistic environment for self-identified Black and White individuals who drink alcohol and (2) whether a history of attention deficit hyperactivity disorder (ADHD) moderated these associations. Design and Setting Observational study using ecological momentary assessment (EMA) to collect data from participants at six semi-random time-points throughout the day during a 10-day period. A series of three-level multi-level models examined between- and within-person associations for stress and alcohol and tested if these associations differed for Black and White adults. Participants Participants were 229 adult drinkers (aged 21-35 years) who completed a larger study examining alcohol response for Black and White adults with and without a history of childhood ADHD. Measurements Momentary stress and alcohol craving, ADHD history and socio-demographic characteristics (i.e. racial identity, sex, age, current education level, household income) were assessed. Participants were required to self-identify as either 'African American or Black' or 'European American or White'. Findings Significant racial identity x stress interactions indicated that associations between stress and craving were stronger for black compared with white adults across the 10-day period (between-person: B = 0.14, P = 0.007), concurrently within a given EMA time-point (within-person: B = 0.04, P = 0.001) and prospectively from time-point to time-point (within-person: B = 0.05, P = 0.001). Results remained while accounting for income x stress interactions. Conclusions Acute stress appears to be more strongly related to alcohol craving in self-identified black compared with self-identified white individuals. This provides support for

关键词： ETS1   5-methylcytosine   5mC deamination   MBD4   IDH2 hotspot mutation   CpG dinucleotide  

摘要： Cytosine to thymine (C>T) somatic mutation is highly enriched in certain types of cancer, and most commonly occurs via deamination of a 5-methylcytosine (5mC) to thymine, in the context of a CpG dinucleotide. In theory, deamination should occur at equal rates to both 5mC nucleotides on opposite strands. In most cases, the resulting T:G or G:T mismatch can be repaired by thymine DNA glycosylase activities. However, while some hotspotassociated CpG mutations have approximately equal numbers of mutations that resulted either from C>T or G>A in a CpG dinucleotide, many showed strand bias, being skewed toward C>T of the first base pair or G>A of the second base pair. Using the IDH2 Arg140 codon as a case study, we show that the two possible T:G mismatches at the codon-specific CpG site have differing effects on transcription factor ETS1 binding affinity, differentially affecting access of a repair enzyme (MBD4) to the deamination-caused T:G mismatch. Our study thus provides a plausible mechanism for exclusion of repair enzymes by the differential binding of transcription factors affecting the rate at which the antecedent opposite-strand mutations occur.

摘要： We study the dual role of active labor market policies. First, active labor market programs (ALMPs) may perform a screening role by increasing job-search incentives already before program participation, especially among individuals with good labor market prospects. Second, actual program participation may help individuals with poor labor market prospects. We examine whether this type of pattern can be found in individual responses to a nationwide youth activation program in Sweden using a regression discontinuity (RD) design. We find that individuals with a high predicted probability of finding work respond to the threat of activation, whereas there is no effect for individuals with weak labor market prospects.

关键词： benzodiazepines   critical care   delirium   intensive care unit   propofol   sedation  

摘要： OBJECTIVES: To evaluate whether different gamma-aminobutyric acidergic (GABAergic) sedatives such as propofol and benzodiazepines carry differential risks of post-extubation delirium in the ICU. DESIGN: Retrospective cohort study. SETTING: Seven ICUs in an academic hospital network, Beth Israel Deaconess Medical Center (Boston, MA). PATIENTS: Ten thousand five hundred and one adult patients mechanically ventilated for over 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We tested the hypothesis that benzodiazepine versus propofol-based sedation is associated with fewer delirium-free days within 14 days after extubation. Further, we hypothesized that the measured sedation level evoked by GABAergic drugs is a better predictor of delirium than the drug dose administered. The proportion of GABAergic drug-induced deep sedation was defined as the ratio of days with a mean Richmond Agitation-Sedation Scale of less than or equal to -3 during mechanical ventilation. Multivariable regression and effect modification analyses were used. Delirium-free days were lower in patients who received a high proportion of deep sedation using benzodiazepine compared with propofol-based sedation (adjusted absolute difference, -1.17 d;95% CI, -0.64 to -1.69;p < 0.001). This differential effect was magnified in elderly patients (age > 65) and in patients with liver or kidney failure (p-for-interaction < 0.001) but not observed in patients who received a low proportion of deep sedation (p = 0.95). GABAergic-induced deep sedation days during mechanical ventilation was a better predictor of post-extubation delirium than the GABAergic daily average effective dose (area under the curve 0.76 vs 0.69;p < 0.001). CONCLUSIONS: Deep sedation during mechanical ventilation with benzodiazepines compared with propofol is associated with increased risk of post-extubation delirium. Our data do not support the view that benzodiazepine-based compared with propofol-based sedation in the ICU is an

关键词： Hepatocellular carcinoma   Flow cytometry   Tumor immunology   Immunology   Liver resection  

摘要： Background Liver transplantation and liver resection are curative options for early hepatocellular carcinoma (HCC). The outcome is in part depended on the immunological response to the malignancy. In this study, we aimed to identify immunological profiles of non-HCV/non-HBV HCC patients. Methods Thirty-nine immune cell subsets were measured with multicolor flow cytometry. This immunophenotyping was performed in peripheral blood (PB) and tumor specimens of 10 HCC resection patients and 10 healthy donors. The signatures of the highly differential leukocyte count (hDIF) were analyzed using multidimensional techniques. Functional capability was measured using intracellular IFN-gamma staining (Trial Registration DRKS00013567). Results The hDIF showed activation (subsets of T-, B-, NK- and dendritic cells) and suppression (subsets of myeloid-derived suppressor cells and T- and B-regulatory cells) of the antitumor response. Principal component analysis of PB and tumor infiltrating leukocytes (TIL) illustrated an antitumor activating gradient. TILs showed functional capability by secreting IFN-gamma but did not kill HCC cells. Conclusions In conclusion, the measurement of the hDIF shows distinct differences in immune reactions against non-HBV/non-HCV HCC and illustrates an immunosuppressive gradient toward peripheral blood.

关键词： Spatial cognition   Visual search   Mental rotation   Spatial tasks   Sex differences  

摘要： Visuospatial functions are particularly vulnerable to the aging process. Decline of these processes can seriously affect an individual's functional independence and quality of life. Effectively assessing the spatial abilities of older adults is, therefore, crucial for identifying strategies to maintain cognitive functioning. The purpose of the present study was to use ecological tasks more comparable to activities of daily living to assess spatial ability in older adults. Three hands-on tasks (a visual search task, a low- and a high-mental rotation demand tasks) and a version of the well-known paper-based mental rotation of figures test (Shepard and Metzler, Science 171(3972):701-703, 1971) were given to 60-79-year-old female and male participants. The hands-on tasks required participants to locate, manipulate, and arrange real objects (i.e., toy bricks) in space. Age had a negative impact on visual search but not on mental rotation ability. Male participants outperformed females in the mental rotation tasks, but a trend for the opposite (better performance by females) was found for the visual search task. The results suggest that spatial abilities are not a monolithic construct and that sub-categories of this construct are affected by age and by sex differently. While visual search function is susceptible to decline during old age, mental rotation ability is not. In addition, unlike the paper-based test, the hands-on tasks were found to be age-appropriate with a feasible level of difficulty for all participants. The hands-on tasks may be more appealing as a tool to evaluate, maintain, and/or enhance spatial function in older adults.

摘要： Purpose Previous studies have examined and identified demographic group score differences on United States Medical Licensing Examination (USMLE) Step examinations. It is necessary to explore potential etiologies of such differences to ensure fairness of examination use. Although score differences are largely explained by preceding academic variables, one potential concern is that item-level bias may be associated with remaining group score differences. The purpose of this 2019-2020 study was to statistically identify and qualitatively review USMLE Step 1 exam questions (items) using differential item functioning (DIF) methodology. Method Logistic regression DIF was used to identify and classify the effect size of DIF on Step 1 items meeting minimum sample size criteria. After using DIF to flag items statistically, subject matter expert (SME) review was used to identify potential reasons why items may have performed differently between racial and gender groups, including characteristics such as content, format, wording, context, or stimulus materials. USMLE SMEs reviewed items to identify the group difference they believed was present, if any;articulate a rationale behind the group difference;and determine whether that rationale would be considered construct relevant or construct irrelevant. Results All identified DIF rationales were relevant to the constructs being assessed and therefore did not reflect item bias. Where SME-generated rationales aligned with statistical differences (flags), they favored self-identified women on items tagged to women's health content categories and were judged to be construct relevant. Conclusions This study did not find evidence to support the hypothesis that group-level performance differences beyond those explained by prior academic performance variables are driven by item-level bias. Health professions examination programs have an obligation to assess for group differences, and when present, investigate to what extent, if any, mea