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Calorie restriction or dietary restriction: how far they can protect the brain against neurodegenerative diseases?

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Neural Regeneration Research 2022年第8期17卷 1640-1644页

作者： Tayana Silva de Carvalho Herz-und Diabeteszentrum NRW(HDZ NRW) Bad OeynhausenGermany

Finding the correct nutritional intervention is one of the biggest challenges in treating patients with neurodegenerative *** general,these patients develop strong metabolic alterations,resulting in lower treatment efficacy and higher mortality ***,there are still many open questions regarding the effectiveness of dietary interventions in *** studies have shown that a reduction in calorie intake activates key pathways that might be important for preventing or slowing down the progression of such ***,it is still unclear whether these neuroprotective effects are associated with an overall reduction in calories(hypocaloric diet)or a specific nutrient restriction(diet restriction).Therefore,here we discuss how commonly or differently hypocaloric and restricted diets modulate signaling pathways and how these changes can protect the brain against neurodegenerative diseases.

关键词： Alzheimer’s disease diet therapy dietary intervention epilepsy fasting glucose restriction hypocaloric diet multiple sclerosis Parkinson’s disease stroke

SEQUENTIAL CONVEX PROGRAMMING METHODS FOR SOLVING LARGE TOPOLOGY OPTIMIZATION PROBLEMS： IMPLEMENTATION AND COMPUTATIONAL RESULTS

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Journal of Computational Mathematics 2005年第5期23卷 491-502页

作者： Qin Ni Ch.Zillober K.Schittkowski Nanjing University of Aeronautics and Astronautics 210016 Nanjing China Department of Computer Science University of BayreuthD-95440 BayreuthGermany

In this paper, we describe a method to solve large-scale structural optimization problems by sequential convex programming （SCP）. A predictor-corrector interior point method is applied to solve the strictly convex subproblems. The SCP algorithm and the topology optimization approach are introduced. Especially, different strategies to solve certain linear systems of equations are analyzed. Numerical results are presented to show the efficiency of the proposed method for solving topology optimization problems and to compare different variants.

关键词： Large scale optimization Topology optimization Sequential convex programming method Predictor-corrector interior point method Method of moving asymptotes

Investigation on regenerator temperature inhomogeneity in Stirling-type pulse tube cooler

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Chinese Science Bulletin 2009年第6期54卷 986-991页

作者： SUN DaMing MARC Dietrich GUENTER Thummes Qiu LiMin Institute of Refrigeration and Cryogenics of Zhejiang University Hangzhou 310027 China Institute of Applied Physics University of Giessen Giessen D-35392 Germany TransMIT-Centre for Adaptive Cryotechnology and Sensors Germany

Regenerator is one of the most crucial components to pulse tube cooler (PTC) and thermoacoustic engine. As such regenerator is scaled up to high-power, the thermal and hydrodynamic communication transverse to the acoustic axis gets weaker and weaker. Under this condition, any unsymmetric factor could cause serious instability to the cooler or engine, which degrades their performance. Investigation has been carried out on a high-power two-stage thermal-coupled U-shape Stirling-type PTC. By detailed circumferential temperature measurements along the middle heat exchanger and second stage regen-erator, a kind of temperature inhomogeneity caused by unsymmetric pre-cooling effect of inter-stage thermal bridge was found in the lower part of the regenerator of the PTC. The temperature inhomoge-neity originating from the middle heat exchanger of the second stage regenerator amplified itself in the lower part of the regenerator and then internal streaming formed. The maximal radial temperature dif-ference could reach 30―40 K. Experimental results show that the temperature inhomogeneity intensi-fies with increased pre-cooling power and its direction can be reversed by changing the pre-cooling effect of the first stage PTC to heating effect by using external thermal load. This research shows that it is important to maintain the heating or cooling effects of heat exchangers uniform in high-power re-generative coolers and engines.

关键词：再生温度不均匀性脉管制冷机林型 PTC公司热声发动机中间换热器冷却效果

Anticaries and antimicrobial activities of methanolic extract from leaves of Cleistocalyx operculatus L.

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Asian Pacific Journal of Tropical Biomedicine 2017年第1期7卷 43-48页

作者： Phuong Thi Mai Nguyen Nadin Schultze Christin Boger Zeyad Alresley Albert Bolhuis Ulrike Lindequist Department of Plant Biochemistry Institute of BiotechnologyVietnam Academy of Science and Technology Institute of Pharmacy University of Greifswald Department of Pharmacy and Pharmacology University of Bath

Objective: To investigate antimicrobial activities of methanolic extract of leaves of Cleistocalyx operculatus L.(C. operculatus) grown in ***: The methanolic extract of C. operculatus leaves was phytochemically screened and tested for its antimicrobial activity against six Gram-positive bacteria(three of which were antibiotic multiresistant Staphylococcus spp.), two Gram-negative bacteria,and one fungal species using an agar diffusion method. Anticaries activity was tested using p H drop and biofilm assays formed in 96-well plastic ***: Phytochemical screening revealed the presence of flavonoids and terpenes, in which flavonoid content was 6.8 mg/g dry material. Antibacterial activity of the C. operculatus extract was shown only against Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis and Streptococcus mutans GS-5(S. mutans), and three multiresistant bacteria being Staphylococcus epidermidis 847, Staphylococcus haemolyticus 535 and Staphylococcus aureus North german epidemic strain. Interestingly, methanolic extract of C. operculatus leaves exhibited the anticaries activity against S. mutans in terms of inhibition of acid production and biofilm formation. Activity of two key enzymes responsible for acidogenicity of S. mutans, F-ATPase and phosphotransferase system were inhibited by the extract with IC_(50) of 51.0 and 98.0 m g/m L, respectively. Cytotoxicity of the extract against keratinocytes was found only for higher concentrations [IC_(50)=(119.98 ± 4.63) m g/m L].Conclusions: The methanolic extract of C. operculatus leaves has the potential for development of antimicrobial preparations, especially anticaries products.

关键词： Cleistocalyx operculatus Antibacterial activity Anticaries Cytotoxicity

Impulse Capacitor Discharge Welding of Hollow Structure Made of Nickel-Base Alloy

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Tsinghua Science and Technology 2007年第4期12卷 453-458页

作者：王剑钊 Peter Ohse 吴甦 Ulrich Dilthey Department of Industrial Engineering Tsinghua University Welding and Joining Institute RWTH Aachen Aachen 52062 Germany

Future steam turbines will use hollow structures so that the turbine inlet temperature can be increased to improve the thermal efficiency. These hollow structures are made of the nickel-base alloy Nicrofer 6025 HT and consist of a wire mesh between two cover sheets. The cover sheets can be joined to the wire mesh by capacitor discharge welding due to its extremely short welding duration. The goal of this research is to investigate suitable welding parameters so that the weld spots form in an optimum way to increase the tensile shear strength and reduce spattering. Tensile shear tests, three-point bending tests, and micrographs were used to judge the joint quality of structures made with various welding parameters. The results show that the best welds are obtained with a transmission ratio of 1：200, welding energy of 70% to 95%, and electrode force of 7 to 9 MPa.

关键词： capacitor discharge welding nickel-base alloy hollow structure tensile shear test three-point bending test micrographs

COMPUTATIONAL MULTISCALE METHODS FOR LINEAR HETEROGENEOUS POROELASTICITY

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Journal of Computational Mathematics 2020年第1期38卷 41-57页

作者： Robert Altmann Eric Chung Roland Maier Daniel Peterseim Sai-Mang Pun Department of Mathematics University of AugsburgAugsburgGermany Department of Mathematics The Chinese University of Hong KongHong KongChina Department of Mathematics Texas UniversityUSA

We consider a strongly heterogeneous medium saturated by an incompressible viscous fluid as it appears in geomechanical *** poroelasticity problem suffers from rapidly oscillating material parameters,which calls for a thorough numerical *** this paper,we propose a method based on the local orthogonal decomposition technique and motivated by a similar approach used for linear ***,local corrector problems are constructed in line with the static equations,whereas we propose to consider the full *** allows to benefit from the given saddle point structure and results in two decoupled corrector problems for the displacement and the *** prove the optimal first-order convergence of this method and verify the result by numerical experiments.

关键词： Poroelasticity Heterogeneous media Numerical homogenization Multiscale methods

A comparison of approaches in fitting continuum SEDs

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Research in Astronomy and Astrophysics 2013年第4期13卷 420-434页

作者： Yao Liu David Madlener Sebastian Wolf Hong-Chi Wang Purple Mountain Observatory and Key Laboratory for Radio Astronomy Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institut fr Theoretische Physik und Astrophysik Universitt zu Kiel

We present a detailed comparison of two approaches, the use of a precalculated database and simulated annealing （SA）, for fitting the continuum spectral energy distribution （SED） of astrophysical objects whose appearance is dominated by surrounding dust. While pre-calculated databases are commonly used to model SED data, only a few studies to date employed SA due to its unclear accuracy and convergence time for this specific problem. From a methodological point of view, different approaches lead to different fitting quality, demand on computational resources and calculation time. We compare the fitting quality and computational costs of these two approaches for the task of SED fitting to provide a guide to the practitioner to find a compromise between desired accuracy and available resources. To reduce uncertainties inherent to real datasets, we introduce a reference model resembling a typical circumstellar system with 10 free parameters. We derive the SED of the reference model with our code MC3 D at 78 logarithmically distributed wavelengths in the range [0.3 μm, 1.3 mini and use this setup to simulate SEDs for the database and SA. Our result directly demonstrates the applicability of SA in the field of SED modeling, since the algorithm regularly finds better solutions to the optimization problem than a precalculated database. As both methods have advantages and shortcomings, a hybrid approach is preferable. While the database provides an approximate fit and overall probability distributions for all parameters deduced using Bayesian analysis, SA can be used to improve upon the results returned by the model grid.

关键词： methods numerical - radiative transfer - protoplanetary disks

A threefold approach to rescue the 2030 Agenda from failing

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National Science Review 2023年第7期10卷 13-15页

作者： Prajal Pradhan Bauhaus Earth GmbH Potsdam Institute for Climate Impact Research (PIK) Member of the Leibniz Association

Countries are not on track to meet the2030 Agenda for Sustainable Development [1] that calls for transformative changes to shift the world onto a sustainable and resilient *** 2030Agenda comprises 17 Sustainable Development Goals (SDGs) and 169 targets to be achieved by 2030,balancing the three sustainability dimensions—social,economic,and *** far,SDGs have had a limited transforma-tive impact [2] because of their selective implementation without considering their complex *** interact positively (***) or negatively(***-offs) depending on contextand location-specific *** to meet SDGs will negatively affect the lives of billions of people and worsen socioeconomic and environmental crises.

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WAVELET METHOD FOR CALCULATING THE DEFECT STATES OF TWO-DIMENSIONAL PHONONIC CRYSTALS

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Acta Mechanica Solida Sinica 2008年第2期21卷 104-109页

作者： Zhizhong Yah Yuesheng Wang Chuanzeng Zhang Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China Department of Civil Engineering University of Siegen D-57076 Siegen Germany

Based on the variational theory, a wavelet-based numerical method is developed to calculate the defect states of acoustic waves in two-dimensional phononic crystals with point and line defects. The supercell technique is applied. By expanding the displacement field and the material constants （mass density and elastic stiffness） in periodic wavelets, the explicit formulations of an eigenvalue problem for the plane harmonic bulk waves in such a phononic structure are derived. The point and line defect states in solid-liquid and solid-solid systems are calculated. Comparisons of the present results with those measured experimentally or those from the plane wave expansion method show that the present method can yield accurate results with faster convergence and less computing time.

关键词： acoustic wave phononic crystal defect state wavelet band structure