Structural characterization of sulfated galactofucan from Undaria pinnatifida and its effect on type 2 diabetic mice

A sulfated galactoftucan designated as UpG was obtained from the brown algae Undaria pinnatifida by calcium chloride extraction.Chemical analyses showed that UpG is composed of galactose and fucose at a high sulfation level.Low-molecular weight UpGP-0.5 was prepared from UpG through acid hydrolysis for structure characterization.The backbones of UpG are determined to beα-(1,3)-Fuc,α-(1,4)-Gal,α-(1,3)-Gal,andα-(1,6)-Gal by GC-MS,FT-IR,NMR,and LC-MS analyses.Sulfate groups are modified at C2 and/or C4 of fucose and C3 and/or C4 of galactose.UpG could partially lower blood sugar and serum lipid levels in type 2 diabetic mice.Moreover,UpG treatment regulates the abundance of some specific gut microbiota,such as enriching the abundance of Muribaculum and Christensenellaceae,and reducing that of Bilophila,Tannerellaceae,Candidatus Saccharimonas and Anaerotruncus.The findings characterized the detailed structure of a sulfated galactofucan and investigated its potential for the treatment of type 2 diabetes mellitus.

β-cyclopiazonic acid binds iron demonstrating siderophorelike activity and promotes growth in Pseudomonas aeruginosa

This chemical study reports a novel siderophore-like compound,β-cyclopiazonic acid(1,β-CPA)extracted from marine fungus Aspergillus flavus.The chemical structure ofβ-CPA was elucidated by a combination of extensive spectroscopic analyses and TDDFT-ECD calculations.The iron-binding ability and CAS assays demonstrate thatβ-CPA is a novel siderophore that features a different chemical structure from those of traditional siderophores.Theβ-CPA has no obvious influence on the growth of bacterium Pseudomonas aeruginosa PAO1.However,its iron chelator could promote the growth of P.aeruginosa PAO1,suggesting that P.aeruginosa employed siderophores to sequester iron,which is vital for their survival.The study provides the physiochemical evaluation ofβ-CPA,an unusual skeletonstructure siderophore,which for the first time,was proven to have the ability to bind iron and affect P.aeruginosa growth.This new discovery of siderophore provides an opportunity for developing novel anti-P.aeruginosa drugs.

An Efficient and Privacy-Preserving Data Aggregation Scheme Supporting Arbitrary Statistical Functions in IoT

The Internet of Things(IoT)has profoundly impacted our lives and has greatly revolutionized our lifestyle.The terminal devices in an IoT data aggregation application sense real-time data for the remote cloud server to achieve intelligent decisions.However,the high frequency of collecting user data will raise people concerns about personal privacy.In recent years,many privacy-preserving data aggregation schemes have been proposed.Unfortunately,most existing schemes cannot support either arbitrary aggregation functions,or dynamic user group management,or fault tolerance.In this paper,we propose an efficient and privacy-preserving data aggregation scheme.In the scheme,we design a lightweight encryption method to protect the user privacy by using a ring topology and a random location sequence.On this basis,the proposed scheme supports not only arbitrary aggregation functions,but also flexible dynamic user management.Furthermore,the scheme achieves faulttolerant capabilities by utilizing a future data buffering mechanism.Security analysis reveals that the scheme can achieve the desired security properties,and experimental evaluation results show the scheme's efficiency in terms of computational and communication overhead.

Seed Selection for Data Offloading Based on Social and Interest Graphs

The explosive growth of mobile data demand is becoming an increasing burden on current cellular network.To address this issue,we propose a solution of opportunistic data offloading for alleviating overloaded cellular traffic.The principle behind it is to select a few important users as seeds for data sharing.The three critical steps are detailed as follows.We first explore individual interests of users by the construction of user profiles,on which an interest graph is built by Gaussian graphical modeling.We then apply the extreme value theory to threshold the encounter duration of user pairs.So,a contact graph is generated to indicate the social relationships of users.Moreover,a contact-interest graph is developed on the basis of the social ties and individual interests of users.Corresponding on different graphs,three strategies are finally proposed for seed selection in an aim to maximize overloaded cellular data.We evaluate the performance of our algorithms by the trace data of real-word mobility.It demonstrates the effectiveness of the strategy of taking social relationships and individual interests into account.

CFD Analysis and Optimization of a Diesel Engine Cooling Water Jacket

The STAR-CCM+software is used to investigate the flow inside a cooling water jacket of an in-line six-cylinder diesel engine.The results show that the average flow velocity of the cooling water inside the jacket is 1.669 m/s while the flow velocity distribution is not uniform for each cylinder.Moreover,the fluid velocity in proximity to the cylinder head is too low,thereby affecting the cooling performances of the water jacket.Two corresponding structural optimization schemes are proposed to mitigate this issue and the post-optimization performances of the water jacket are discussed in detail.

Chassis tra fficability simulation and experiment of a LY1352JP forest tracked vehicle

Based on the analysis of complex terrains and current forest transportation equipment,a forest tracked vehicle prototype LY1352 JP was developed.The road model and the virtual prototype of the chassis were constructed using dynamic simulation software RecurDyn.The optimal tension of the vehicle as well as its capabilities for crossing trenches,climbing vertical walls,uphill and downhill slopes were simulated.The simulation results showed that the optimum tension force of the chassis of the vehicle was 63 kN(kilonewton),accounting for 45%of the total vehicle weight.The maximum trench crossing width and vertical obstacle climbing height were 1.35 m and 0.45 m,respectively.The maximum uphill and downhill angles were 50°and 45°,respectively.Tests on the prototype capacity for crossing trenches,and uphill and downhill driving were carried out.The test results were in agreement with the simulation results.A cross-country performance of a fire truck based on the tracked vehicle chassis was conducted in an old-growth forest.Tests verified that the vehicle has a strong forest trafficability performance and can meet the needs for forest transportation.

Predicting Human Mobility via Long Short-Term Patterns

Predicting human mobility has great significance in Location based Social Network applications,while it is challenging due to the impact of historical mobility patterns and current trajectories.Among these challenges,historical patterns tend to be crucial in the prediction task.However,it is difficult to capture complex patterns from long historical trajectories.Motivated by recent success of Convolutional Neural Network(CNN)-based methods,we propose a Union ConvGRU(UCG)Net,which can capture long short-term patterns of historical trajectories and sequential impact of current trajectories.Specifically,we first incorporate historical trajectories into hidden states by a shared-weight layer,and then utilize a 1D CNN to capture short-term pattern of hidden states.Next,an average pooling method is involved to generate separated hidden states of historical trajectories,on which we use a Fully Connected(FC)layer to capture longterm pattern subsequently.Finally,we use a Recurrent Neural Net-work(RNN)to predict future trajectories by integrating current trajectories and long short-term patterns.Experiments demonstrate that UCG Net performs best in comparison with neural network-based methods.

The preparation of nitrogen-doped TiO_2 nanocrystals with exposed {001} facets and their visible-light photocatalytic performances

Anatase TiO2with exposed{001}facets has been deepgoingly studied for optimizing its photocatalytic activity.In this study,we synthesized N-doped TiO2 nanocrystals with exposed{001}facets by sol–gel method and solvothermal method,respectively.The physical and chemical properties of as-synthesized samples,such as morphology,crystal phase,surface elements composition,porous structure,specific surface area,and optical response,were characterized in detail.The photocatalytic performances of all samples were evaluated by photocatalytic decoloration of methylene blue under visible-light irradiation(k[420 nm).The results showed that the as-prepared samples present high visible-light photocatalytic performances,which can be ascribed to the excellent crystallization,the enhancement of absorbance in the visible-light region,and the strong adsorption performance,and calcination treatment is helpful to further improve the visible-light photocatalytic performance of N-doped TiO2 nanocrystals with exposed{001}facets.

The Gender-Biased Employment Effect of Exports： Evidence from China

传统的国际贸易理论相信出口贸易在雇用上有积极效果，它意味着出口将没有性之间的差别增加雇用的水平。然而，基于企业异质新贸易的理论怀疑这个结论。用中国工业企业数据库(20062009 ) ，这份报纸覆查在出口体积和雇用的水平之间的关系，并且在不同的性的雇用上讨论出口的不同效果。我们发现尽管出口增加雇用的全部的水平，企业出口在女人的雇用上有突出的否定效果。这证明它是难的通过外贸的提升优化雇用结构，就算它改进雇用的全面水平。

Aberration correction for deformable-mirror-based remote focusing enables high-accuracy whole-cell super-resolution imaging

Single-molecule localization microscopy(SMLM)enables three-dimensional(3D)investigation of nanoscale structures in biological samples,offering unique insights into their organization.However,traditional 3D super-resolution microscopy using high numerical aperture(NA)objectives is limited by imaging depth of field(DOF),restricting their practical application to relatively thin biological samples.Here,we developed a unified solution for thick sample super-resolution imaging using a deformable mirror(DM)which served for fast remote focusing,optimized point spread function(PSF)engineering,and accurate aberration correction.By effectively correcting the system aberrations introduced during remote focusing and sample aberrations at different imaging depths,we achieved high-accuracy,large DOF imaging(~8μm)of the whole-cell organelles[i.e.,nuclear pore complex(NPC),microtubules,and mitochondria]with a nearly uniform resolution of approximately 35 nm across the entire cellular volume.