Publications by authors named "Ang Zhang"

39 Publications

3D Phase Field Modeling of Multi-Dendrites Evolution in Solidification and Validation by Synchrotron X-ray Tomography.

Materials (Basel) 2021 Jan 21;14(3). Epub 2021 Jan 21.

Department of Engineering, University of Hull, Cottingham Road, Hull HU6 7RX, UK.

In this paper, the dynamics of multi-dendrite concurrent growth and coarsening of an Al-15 .% Cu alloy was studied using a highly computationally efficient 3D phase field model and real-time synchrotron X-ray micro-tomography. High fidelity multi-dendrite simulations were achieved and the results were compared directly with the time-evolved tomography datasets to quantify the relative importance of multi-dendritic growth and coarsening. Coarsening mechanisms under different solidification conditions were further elucidated. The dominant coarsening mechanisms change from small arm melting and interdendritic groove advancement to coalescence when the solid volume fraction approaches ~0.70. Both tomography experiments and phase field simulations indicated that multi-dendrite coarsening obeys the classical Lifshitz-Slyozov-Wagner theory Rn-R0n = kc(t-t0), but with a higher constant of = 4.3.
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http://dx.doi.org/10.3390/ma14030520DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7865333PMC
January 2021

Foliar Phenylalanine Application Promoted Antioxidant Activities in Cabernet Sauvignon by Regulating Phenolic Biosynthesis.

J Agric Food Chem 2020 Dec 15;68(52):15390-15402. Epub 2020 Dec 15.

College of Enology, College of Food Science and Engineering, Technology Center of State Forestry and Grassland Administration, Shaanxi Engineering Research Center for Viti-Viniculture, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China.

The effects of foliar phenylalanine application during veraison (FPV) on phenolic biosynthesis and correlation between phenolic compositions and antioxidant activities in Cabernet Sauvignon grown in field and greenhouse were investigated. Solutions with 69 and 138 mg N/vine phenylalanine (Pe1 and Pe2, respectively) and an aqueous solution without nitrogen (CK) were sprayed three times during veraison. FPV significantly improved antioxidant activities in grapes using the two culture methods. The most contributory phenolic compositions to antioxidant activities were anthocyanins and stilbenes following FPV compared with CK. Phenylalanine metabolism, abscisic acid content, and expression levels of , , , , and in the phenolic synthesis pathway were increased from the first FPV to harvest. Although Pe2 significantly increased total phenolic contents than Pe1, antioxidant parameters were not markedly affected by the phenylalanine dose. Our finding revealed that FPV was a useful fertilization method to enhance antioxidant activities in grapes in nitrogen-deficient vineyards.
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http://dx.doi.org/10.1021/acs.jafc.0c05565DOI Listing
December 2020

Determination of geographical origin of concentrated apple juice through analysis of stable isotopic and mineral elemental fingerprints: preliminary results.

J Sci Food Agric 2020 Dec 11. Epub 2020 Dec 11.

Technical Center of Qinhuangdao Customs, Qinhuangdao, China.

Background: With increasing attention being paid to food authenticity, the geographic origin of food has become a topic of interest for both consumers and producers. As far as we know, there are relatively few studies on the origin traceability of concentrated apple juice. The most commonly used methods of origin tracing research is by using stable isotopes and mineral elements technology, because these indicators are directly related to local geographical environment.

Results: In this study, a discriminant model was established by determining the content of the stable isotopes (δ C, δ O) and 13 mineral elements (B, Mn, Co, Ni, Cu, Sr, V, Ba, Fe, Mg, Na, Ca and Cr) in concentrated apple juice. Linear discriminant analysis (LDA), principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were employed for regional classification of samples. After data conversion and correlation analysis, spatial and quantitative prediction models were established using multiple linear regressions. Finally, the experimental results showed that the eight key variables(δ C, δ O, B, Ca, Mg, Cu, Sr and Na) selected by the analysis can be used to further characterize the production area.

Conclusion: The results showed that the carbon and oxygen isotopes combined with certain mineral elements can be used to indicate the origin of concentrated apple juice. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.11012DOI Listing
December 2020

Foliar nitrogen application from veraison to preharvest improved flavonoids, fatty acids and aliphatic volatiles composition in grapes and wines.

Food Res Int 2020 11 20;137:109566. Epub 2020 Jul 20.

College of Enology, College of Food Science and Engineering, Viti-Viniculture Engineering Technology Center of State Forestry and Grassland Administration, Shaanxi Engineering Research Center for Viti-Viniculture, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China. Electronic address:

This study investigated the effects of foliar nitrogen application from veraison to preharvest (FNVH) on flavonoids, fatty acids and aliphatic volatiles in Cabernet Sauvignon grapes and wines. Solutions with 69 and 138 mg N/plant phenylalanine (P1 and P2, respectively), 69 and 138 mg N/plant urea (U1 and U2, respectively), as well as an aqueous solution without nitrogen (CK), were sprayed three times from veraison to preharvest. U1, P1 had the highest anthocyanins and acylated anthocyanins contents in grapes, respectively. U1 and P2 showed great potential to promote the accumulation of flavonols and flavanols in grapes and wines. U2 increased the contents of almost all free aliphatic volatiles in grapes, while it didn't affect the undesirable smell, and increased the concentrations of fruity esters in wines instead. The study showed FNVH was a useful fertilization way for improving contents of flavonoids and fruity aroma in grapes and wines in deficit-nitrogen vineyards.
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http://dx.doi.org/10.1016/j.foodres.2020.109566DOI Listing
November 2020

General hierarchical structure to solve transport phenomena with dissimilar time scales: Application in large-scale three-dimensional thermosolutal phase-field problems.

Phys Rev E 2020 Oct;102(4-1):043313

School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.

A general hierarchical structure is developed for phase-field lattice-Boltzmann simulations with dissimilar time scales. The number of the grid levels can be artificially selected in a reasonable range, which can enhance the time marching step by two to three orders of magnitude in comparison with explicit methods. Constructed on a massively parallel platform, the mesh distribution is dynamically adjusted according to a gradient criterion. The developed high performance computing scheme is applied to simulate the coupled thermosolutal dendrite evolution. Numerical tests indicate that the computing efficiency can be further improved by two to three orders of magnitude, which makes numerical simulation of fully coupled thermosolutal dendrite growth viable for alloys with Lewis number ∼10^{4}. The domain size which equivalently consists of billions of uniform meshes is handled to simulate multidendrite evolution. Results show that the domain temperature becomes extremely uneven due to the release of latent heat, which causes a significant difference from isothermal solidification. A simple analytical model is proposed to predict the relation between growth velocity and Lewis number, and the growth morphologies of both equiaxed and directional multiple dendrites are discussed. The combination of the hierarchical mesh structure and the phase-field lattice-Boltzmann method provides an efficiency-driven approach to solve the coupled thermosolutal microstructure evolution.
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http://dx.doi.org/10.1103/PhysRevE.102.043313DOI Listing
October 2020

Effect of laser cleaning of carbon fiber-reinforced polymer and surface modification on chemical activity and bonding strength.

Appl Opt 2020 Nov;59(32):10149-10159

Bonding has been used to repair carbon fiber-reinforced polymer (CFRP) materials. However, research has shown that resin residue on the surface of CFRP can cause adhesion problems. Therefore, a reliable surface cleaning procedure is necessary to remove the resin residue before bonding. In this paper, the surface resin was removed by laser cleaning, while the surface properties of CFRP were improved. A pulsed laser cleaning experiment was designed to study the chemical activity and bonding strength of CFRP treated by laser with different laser power and scanning speed. The results showed that as the contact angle of the material surface decreased, chemical activity and adhesive properties were improved. The surface pretreated with laser power of 16 W (scanning speed of 1500 mm/s) had no resin residue and the best adhesive properties; the bonding strength was 1.6 times higher than that of the untreated surface, and the failure mode was dominated by a cohesive damage mode.
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http://dx.doi.org/10.1364/AO.404846DOI Listing
November 2020

Mesenchymal Stem Cell-Conditioned Medium Improves Mitochondrial Dysfunction and Suppresses Apoptosis in Okadaic Acid-Treated SH-SY5Y Cells by Extracellular Vesicle Mitochondrial Transfer.

J Alzheimers Dis 2020 ;78(3):1161-1176

Department of Hematopoietic Stem Cell Transplantation, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China.

Background: Mesenchymal stem cells-conditioned medium (MSC-CM) provides a promising cell-free therapy for Alzheimer's disease (AD) mainly due to the paracrine of MSCs, but the precise mechanisms remain unclear. Studies suggests that mitochondrial dysfunction precedes the accumulation of amyloid-β plaques and neurofibrillary tangles, and involves in the onset and development of AD.

Objective: In the present study, we evaluated the protective effects and explored the related-mitochondrial mechanisms of human umbilical cord derived MSC-CM (hucMSC-CM) in an AD model in vitro.

Methods: To this end, an AD cellular model was firstly established by okadaic acid (OA)-treated SH-SY5Y cells, and then treated by hucMSC-CM to assess the oxidative stress, mitochondrial function, apoptosis, AD-related genes, and signaling pathways.

Results: hucMSC-CM significantly deceased tau phosphorylated at Thr181 (p181-tau) level, which was increased in AD. hucMSC-CM also alleviated intracellular and mitochondrial oxidative stress in OA-treated SH-SY5Y cells. In addition, hucMSC-CM suppressed apoptosis and improved mitochondrial function in OA-treated SH-SY5Y cells. Flow cytometric analysis indicated that hucMSC-CM exerted the protective effects relying on or partly extracellular vesicle (EV) mitochondrial transfer from hucMSCs to OA-treated SH-SY5Y cells. Moreover, RNA sequencing data further demonstrated that hucMSC-CM regulated many AD-related genes, signaling pathways and mitochondrial function.

Conclusion: These results indicated that MSC-CM or MSC-EVs containing abundant mitochondria may provide a novel potential therapeutic approach for AD.
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http://dx.doi.org/10.3233/JAD-200686DOI Listing
January 2020

Using foliar nitrogen application during veraison to improve the flavor components of grape and wine.

J Sci Food Agric 2021 Mar 25;101(4):1288-1300. Epub 2020 Sep 25.

College of Enology, Technology Center of State Forestry and Grassland Administration, Shaanxi Engineering Research Center for Viti-Viniculture, Heyang Viti-Viniculture Station, Northwest A&F University, No. 22 Xinong Road, Yangling, shaanxi, 712100, China.

Nitrogen is involved in the winemaking process from grapevine growth to wine fermentation, and its precise utilization in vineyards can regulate grape and wine quality. Foliar nitrogen application during veraison (FNAV) could prevent nitrogen deficiency in grape and must in nitrogen-deficient vineyards. Moreover, FNAV also could improve certain flavor components of grape and wine, but little attention has been paid to FNAV. Therefore, this paper mainly reviews the difficulties encountered in current applications of nitrogen in vineyards and wineries, and the advantages of FNAV over the addition of nitrogen in soil and wineries. And it discusses that FNAV can increase yeast-assimilable nitrogen and phenolics, and scarcely affect volatile components of grape (must and wine), and points out the existing problems including the core issue and then puts forward future research directions. This information may indicate future directions for research, and provide a reference for viticulturists and winemakers on the precise application of nitrogen on grapevine and must to further improve grape and wine quality in nitrogen-deficient vineyards. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10782DOI Listing
March 2021

Regulating lamellar eutectic trajectory through external perturbations.

Phys Rev E 2020 Jun;101(6-1):061301

School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.

The present understanding of asymmetric lamellar eutectics focuses on pure diffusive transport, and how the external perturbations cause asymmetric pattern transitions remains unclear. In this work, the effect of external perturbations is discussed in terms of both thermal and convective effects via phase-field modeling. The presence of thermal perturbation distorts eutectic lamellae, while the convective perturbation causes a tilt band. Both can adjust the eutectic trajectory to accommodate newly established thermodynamics by reconstructing the transport equilibrium. Furthermore, how to regulate the eutectic growth (eutectic colony, zigzag, and snakelike patterns) by altering external perturbations is investigated, which provides information on how to control eutectic evolution.
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http://dx.doi.org/10.1103/PhysRevE.101.061301DOI Listing
June 2020

Secretion of human soluble programmed cell death protein 1 by chimeric antigen receptor-modified T cells enhances anti-tumor efficacy.

Cytotherapy 2020 12 17;22(12):734-743. Epub 2020 Jul 17.

Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China; Department of Hematopoietic Stem Cell Transplantation, the Fifth Medical Center of Chinese PLA General Hospital, Beijing, China; Department of Hematopoietic Stem Cell Transplantation, the Cell and Gene Therapy Center, the Fifth Medical Center of Chinese PLA General Hospital, Beijing, China; Beijing Key Laboratory of Stem Cell Therapy and Transformation Research, Beijing, China. Electronic address:

Background Aims: Chimeric antigen receptor (CAR) T cells have achieved favorable responses in patients with hematologic malignancies, but the outcome has been far from satisfactory in the treatment of tumors with high expression of immunosuppressive molecules. To overcome this limitation, we modified CAR T cells to secrete types of human soluble programmed cell death protein 1 (PD-1) called sPD-1 CAR T cells.

Methods: To compare the effector function between second (conventional second-generation CAR targeting CD19) and sPD-1 CAR T cells, we measured cytotoxicity, cytokine secretion and activation markers incubated with or without tumor cells expressing CD19 and/or programmed cell death ligand 1 (PD-L1). Furthermore, the anti-tumor efficacy of second and sPD-1 CAR T cells was determined using an NSG mouse model bearing NALM-6-PD-L1. Finally, the underlying mechanism was investigated by metabolic parameters and RNA sequencing analysis of different CAR T cells.

Results: Compared with second CAR T cells, sPD-1 CAR T cells enhanced killing efficiency toward CD19PD-L1 tumor cells in vitro. Furthermore, sPD-1 CAR T cells reduced the tumor burden and prolonged overall survival of the NSG (NOD-SCID-IL2rg) mice bearing NALM-6-PD-L1. To explore the effect of soluble PD-1 on CAR T cells, we found that sPD-1 CAR T cells exhibited higher levels of activation and ameliorative profiles of differentiation, exhaustion, glycolysis and apoptosis.

Conclusions: With constitutive soluble PD-1 secretion, sPD-1 CAR T cells have tended to eradicate tumors with a high expression of PD-L1 more effectively than second CAR T cells. This may be due to soluble PD-1 enhancing apoptosis resistance, aerobic metabolism and a more "stem" differentiation of CAR T cells. Overall, our study presents a feasible strategy to increase the efficacy of CAR T cells.
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http://dx.doi.org/10.1016/j.jcyt.2020.05.007DOI Listing
December 2020

Geographical Origin Classification of Chinese Wines Based on Carbon and Oxygen Stable Isotopes and Elemental Profiles.

J Food Prot 2020 Aug;83(8):1323-1334

College of Enology, Northwest A&F University, Yangling 712100, People's Republic of China ; ).

Abstract: Wines from different regions have different qualities due to the impact of geographical location and climate. The sale of inferior wines seriously violates the fair-trade rights of consumers. This article provides an elemental analysis classification method for verifying the geographical origin of wines in the People's Republic of China. Inductively coupled plasma mass spectrometry, liquid chromatography isotope ratio mass spectrometry, and an isotope ratio mass spectrometer were used to analyze 142 wine samples collected from Helan Mountain, Xinjiang, Yunchuanzang, the Yanhuai Valley, and the Hexi Corridor regions. The data included elemental profiles, carbon isotope ratios (δ13C), and oxygen isotope ratios (δ18O). The results of multivariate analysis revealed that the geographical origin of wine is closely related to variations in elemental profiles and isotope ratios. Introducing δ18O and the elements Li, Mn, Ag, In, Th, Ta, and Re into the discriminant model yielded correct classification rates of the linear discriminant model of 90.8% for the training set and 87.3% for the test set.

Highlights:
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http://dx.doi.org/10.4315/JFP-19-499DOI Listing
August 2020

Biomass estimation and physicochemical characterization of winter vine prunings in the Chinese and global grape and wine industries.

Waste Manag 2020 Mar 21;104:119-129. Epub 2020 Jan 21.

College of Enology, College of Food Science and Engineering, Viti-viniculture Engineering Technology Center of State Forestry and Grassland Administration, Shaanxi Engineering Research Center for Viti-Viniculture, Heyang Viti-viniculture Station, Northwest A&F University, Yangling 712100, China. Electronic address:

The residual biomass of winter vine prunings (WVPs) in the Chinese and global grape and wine industries was investigated and estimated, and the physicochemical characteristics of Chinese WVPs were analyzed. The eight regions investigated within China showed a total annual regional WVP yield of 201-842 kt FW, with R1 and R6 region showing the highest and the lowest region yields, respectively. The R4 and R2 regions showed the highest and the lowest yield per tree. Table grapes showed considerably higher WVP yields than wine grapes, whereas the pergola systems showed considerably higher WVP yields than the hedge systems. In addition, older vines showed higher WVP yields than younger vines. Overall, the average WVP yield in China was 2.35 kg/tree FW with a range of 1.33-3.21 kg/tree FW. Globally, the estimated WVP yield has decreased gradually from 2000 to 2017 to 42.31 million ton FW; in contrast, estimated WVP yield in China has increased substantially over the same period to 6.04 million ton FW. Winter vine pruning was the leading source of solid grape waste in the grape and wine industry, both absolutely and proportionally, and was characterized by such properties as a high dry matter content, mild acidity, high levels of organic matter and nutrients, and low fat. It is clear that WVP represents a resource of immense value for generating additional wealth in China and in the global grape and wine industry.
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http://dx.doi.org/10.1016/j.wasman.2020.01.018DOI Listing
March 2020

Effect of Temperature Gradient on the Grain Size Homogeneity of SEED Produced Semi-Solid Slurries by Phase-Field Simulation.

Materials (Basel) 2019 Oct 11;12(20). Epub 2019 Oct 11.

General Research Institute for Nonferrous Metals, Beijing 101407, China.

The distribution homogeneity of grain size affects the fluidity of the semi-solid slurry, which in turn affects the properties of the casting. One key factor affecting grain size uniformity resides in the nucleation number, which has been studied thoroughly, while the other factor is temperature gradient which has not been investigated yet. In this study, the microstructure evolutions under certain temperature gradients are investigated by experiment and simulation using a two-dimensional quantitative phase-field (PF) model. A parallel and adaptive mesh refinement algorithm is adopted to solve the nonlinear phase-field equations. The results indicate that temperature gradient can affect the size distribution of microstructure in the semi-solid slurry prepared by the SEED process. A higher temperature gradient (in the range of 0.230~0.657 °C/mm) along the radial direction is beneficial to the homogeneity of the grain size in a slurry.
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http://dx.doi.org/10.3390/ma12203309DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829422PMC
October 2019

Conservative phase-field method with a parallel and adaptive-mesh-refinement technique for interface tracking.

Phys Rev E 2019 Aug;100(2-1):023305

School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.

Based on Fick's second law and Cahn-Hilliard theory, a conservative phase-field model is developed to track interface. The phase-field variable changes in a hyperbolic tangent behavior across the diffuse interface over which the interface curvature can be easily calculated. Different from the frequently used lattice-Boltzmann-based discrete method, the phase-field equation is discretized using a fourth-order Runge-Kutta method. Accordingly, the present numerical scheme alleviates the programming burden, reduces the memory usage, but maintains a high numerical accuracy. To achieve large-scale interface tracking, a parallel and adaptive-mesh-refinement algorithm is developed to reduce the computing overhead. Various cases of the interface evolutions under steady flow fields indicate that the proposed numerical scheme can capture the interface with high accuracy. Furthermore, the robustness of the numerical scheme is validated by simulating the Rayleigh-Taylor instability, and good agreement with previous work is achieved.
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http://dx.doi.org/10.1103/PhysRevE.100.023305DOI Listing
August 2019

Litter addition decreases plant diversity by suppressing seeding in a semiarid grassland, Northern China.

Ecol Evol 2019 Sep 15;9(17):9907-9915. Epub 2019 Aug 15.

International Joint Research Laboratory of Global Change Ecology School of Life Sciences Henan University Kaifeng China.

Plant community diversity is conducive to maintain the regional ecosystems stability and ecosystem services. Seed germination is one of the main ways to regulate plant diversity, owing to seedling recruitment as a basis for plant community renewal. However, the exact mechanism of how plant litter affects seedling recruitment, and species richness is not yet fully understood. Therefore, a litter addition and removal experiment was established in a semiarid grassland to study the effects of plant litter on seedling recruitment and species richness from April to August in 2016 and 2017 in Northern China. The positive correlation between species richness and seedling recruitment indicated that a guarantee of seedling recruitment was the main precondition to protect species richness. Adding rather than removing litter significantly reduced species richness. Litter addition inhibited species richness by directly increasing mechanical damage or indirectly reducing photosynthetically active radiation and seedling recruitment. The results of this study are conducive to understand the evolutionary and regulatory mechanisms of community species richness and seedling recruitment in grassland ecosystems after adding or removing plant litter.

Open Research Badges: This article has been awarded Open Data, Open Materials and Preregistered research design Badges. All materials and data are publicly accessible via the Open Science Framework at https://doi.org/10.5061/dryad.5dj3jg5 and http://doi.org/10.5061/dryad.13gj03s.
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http://dx.doi.org/10.1002/ece3.5532DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745658PMC
September 2019

Climate and air pollution alter incidence of tuberculosis in Beijing, China.

Ann Epidemiol 2019 09 13;37:71-76. Epub 2019 Jul 13.

International Joint Research Laboratory of Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan, China. Electronic address:

Purpose: This study evaluated the possible association between climate and environment and the incidence of tuberculosis and determined the characteristics of tuberculosis in different climatic and air pollution conditions.

Methods: Data on tuberculosis incidence, climate (i.e., precipitation, atmospheric pressure, relative humidity, temperature, and wind speed), and air quality (inhalable particulate matter, sulfur dioxide, and nitrogen dioxide concentrations) in Beijing from 2004 to 2016 were collected and systematically analyzed based on a structural equation model.

Results: The tuberculosis incidence was negatively correlated with the concentration of inhalable particulate matter, sulfur dioxide, or nitrogen dioxide. Precipitation, atmospheric pressure, and relative humidity had negative effects on tuberculosis incidence by indirectly lowering the concentrations of inhalable particulate matter and sulfur dioxide. By contrast, wind speed had a significant positive correlation with the incidence of tuberculosis. Temperature and wind speed had positive effects on tuberculosis incidence by improving the concentrations of inhalable particulate matter and sulfur dioxide.

Conclusions: Climate and air quality are potential regulators of the incidence of tuberculosis. The improved air quality contributes to the decline of incidence of tuberculosis in Beijing. The impact of climatic indicators on the incidence of tuberculosis was mainly regulated by the environment. Further studies are needed to formulate preventive and regulatory strategies for tuberculosis based on different climatic and air quality conditions.
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http://dx.doi.org/10.1016/j.annepidem.2019.07.003DOI Listing
September 2019

A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change.

Nat Ecol Evol 2019 09 19;3(9):1309-1320. Epub 2019 Aug 19.

Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA.

Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO. The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.
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http://dx.doi.org/10.1038/s41559-019-0958-3DOI Listing
September 2019

A Human Health Risk Assessment of Trace Elements Present in Chinese Wine.

Molecules 2019 Jan 11;24(2). Epub 2019 Jan 11.

College of Enology, Northwest A&F University, Yangling 712100, China.

The concentrations of trace elements in wines and health risk assessment via wine consumption were investigated in 315 wines. Samples were collected from eight major wine-producing regions in China. The concentrations of twelve trace elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and Duncan's multiple range test was applied to analyze significant variations ( < 0.05) of trace elements in different regions. Based on a 60 kg adult drinker consuming 200 mL of wine per day, the estimated daily intake (EDI) of each element from wines was far below the provisional tolerable daily intake (PTDI). Health risk assessment indicated the ingestion influence of individual elements and combined elements through this Chinese wine daily intake did not constitute a health hazard to people. However, Cr and Mn were the potential contaminants of higher health risk in Chinese wines. The cumulative impact of wine consumption on trace elements intake in the daily diet of drinkers should not be ignored due to the presence of other intake pathways.
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http://dx.doi.org/10.3390/molecules24020248DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359022PMC
January 2019

Translational and Rotational Dynamical Heterogeneities in Granular Systems.

Phys Rev Lett 2018 Jul;121(1):018002

School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China.

We use x-ray tomography to investigate the translational and rotational dynamical heterogeneities of a three dimensional hard ellipsoid granular packing driven by oscillatory shear. We find that particles which translate quickly form clusters with a size distribution given by a power law with an exponent that is independent of the strain amplitude. Identical behavior is found for particles that are translating slowly, rotating quickly, or rotating slowly. The geometrical properties of these four different types of clusters are the same as those of random clusters. Different cluster types are considerably correlated or anticorrelated, indicating a significant coupling between translational and rotational degrees of freedom. Surprisingly, these clusters are formed already at time scales that are much shorter than the α-relaxation time, in stark contrast to the behavior found in glass-forming systems.
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http://dx.doi.org/10.1103/PhysRevLett.121.018002DOI Listing
July 2018

Atomistic Determination of Anisotropic Surface Energy-Associated Growth Patterns of Magnesium Alloy Dendrites.

ACS Omega 2017 Dec 8;2(12):8803-8809. Epub 2017 Dec 8.

School of Materials Science and Engineering and Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084, China.

Because of the existence of anisotropic surface energy with respect to the hexagonal close-packed (hcp) lattice structure, magnesium alloy dendrite prefers to grow along certain crystallographic directions and exhibits a complex growth pattern. To disclose the underlying mechanism behind the three-dimensional (3-D) growth pattern of magnesium alloy dendrite, an anisotropy function was developed in light of the spherical harmonics and experimental findings. Relevant atomistic simulations based on density functional theory were then performed to determine the anisotropic surface energy along different crystallographic directions, and the corresponding anisotropic strength was quantified via the least-square regression. Results of phase field simulations showed that the proposed anisotropy function could satisfactorily describe the 3-D growth pattern of the α-Mg dendrite observed in the experiments. Our investigations shed great insight into understanding the pattern formation of the hcp magnesium alloy dendrite at an atomic level.
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http://dx.doi.org/10.1021/acsomega.7b01174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645556PMC
December 2017

Granular materials flow like complex fluids.

Nature 2017 11 1;551(7680):360-363. Epub 2017 Nov 1.

School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China.

Granular materials such as sand, powders and foams are ubiquitous in daily life and in industrial and geotechnical applications. These disordered systems form stable structures when unperturbed, but in the presence of external influences such as tapping or shear they 'relax', becoming fluid in nature. It is often assumed that the relaxation dynamics of granular systems is similar to that of thermal glass-forming systems. However, so far it has not been possible to determine experimentally the dynamic properties of three-dimensional granular systems at the particle level. This lack of experimental data, combined with the fact that the motion of granular particles involves friction (whereas the motion of particles in thermal glass-forming systems does not), means that an accurate description of the relaxation dynamics of granular materials is lacking. Here we use X-ray tomography to determine the microscale relaxation dynamics of hard granular ellipsoids subject to an oscillatory shear. We find that the distribution of the displacements of the ellipsoids is well described by a Gumbel law (which is similar to a Gaussian distribution for small displacements but has a heavier tail for larger displacements), with a shape parameter that is independent of the amplitude of the shear strain and of the time. Despite this universality, the mean squared displacement of an individual ellipsoid follows a power law as a function of time, with an exponent that does depend on the strain amplitude and time. We argue that these results are related to microscale relaxation mechanisms that involve friction and memory effects (whereby the motion of an ellipsoid at a given point in time depends on its previous motion). Our observations demonstrate that, at the particle level, the dynamic behaviour of granular systems is qualitatively different from that of thermal glass-forming systems, and is instead more similar to that of complex fluids. We conclude that granular materials can relax even when the driving strain is weak.
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http://dx.doi.org/10.1038/nature24062DOI Listing
November 2017

Correlation between crystallographic anisotropy and dendritic orientation selection of binary magnesium alloys.

Sci Rep 2017 10 19;7(1):13600. Epub 2017 Oct 19.

School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.

Both synchrotron X-ray tomography and EBSD characterization revealed that the preferred growth directions of magnesium alloy dendrite change as the type and amount of solute elements. Such growth behavior was further investigated by evaluating the orientation-dependent surface energy and the subsequent crystallographic anisotropy via ab-initio calculations based on density functional theory and hcp lattice structure. It was found that for most binary magnesium alloys, the preferred growth direction of the α-Mg dendrite in the basal plane is always [Formula: see text], and independent on either the type or concentration of the additional elements. In non-basal planes, however, the preferred growth direction is highly dependent on the solute concentration. In particular, for Mg-Al alloys, this direction changes from [Formula: see text] to [Formula: see text] as the Al-concentration increased, and for Mg-Zn alloys, this direction changes from [Formula: see text] to [Formula: see text] or [Formula: see text] as the Zn-content varied. Our results provide a better understanding on the dendritic orientation selection and morphology transition of magnesium alloys at the atomic level.
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http://dx.doi.org/10.1038/s41598-017-12814-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5648834PMC
October 2017

Third-generation CD28/4-1BB chimeric antigen receptor T cells for chemotherapy relapsed or refractory acute lymphoblastic leukaemia: a non-randomised, open-label phase I trial protocol.

BMJ Open 2016 12 30;6(12):e013904. Epub 2016 Dec 30.

Cell and Gene Therapy Center, Academy of Military Medical Sciences, Beijing, China.

Introduction: There is no curative treatment available for patients with chemotherapy relapsed or refractory CD19+ B cells-derived acute lymphoblastic leukaemia (r/r B-ALL). Although CD19-targeting second-generation (2nd-G) chimeric antigen receptor (CAR)-modified T cells carrying CD28 or 4-1BB domains have demonstrated potency in patients with advanced B-ALL, these 2 signalling domains endow CAR-T cells with different and complementary functional properties. Preclinical results have shown that third-generation (3rd-G) CAR-T cells combining 4-1BB and CD28 signalling domains have superior activation and proliferation capacity compared with 2nd-G CAR-T cells carrying CD28 domain. The aim of the current study is therefore to investigate the safety and efficacy of 3rd-G CAR-T cells in adults with r/r B-ALL.

Methods And Analysis: This study is a phase I clinical trial for patients with r/r B-ALL to test the safety and preliminary efficacy of 3rd-G CAR-T cells. Before receiving lymphodepleting conditioning regimen, the peripheral blood mononuclear cells from eligible patients will be leukapheresed, and the T cells will be purified, activated, transduced and expanded ex vivo. On day 6 in the protocol, a single dose of 1 million CAR-T cells per kg will be administrated intravenously. The phenotypes of infused CAR-T cells, copy number of CAR transgene and plasma cytokines will be assayed for 2 years after CAR-T infusion using flow cytometry, real-time quantitative PCR and cytometric bead array, respectively. Moreover, several predictive plasma cytokines including interferon-γ, interleukin (IL)-6, IL-8, Soluble Interleukin (sIL)-2R-α, solubleglycoprotein (sgp)130, sIL-6R, Monocyte chemoattractant protein (MCP1), Macrophage inflammatory protein (MIP1)-α, MIP1-β and Granulocyte-macrophage colony-stimulating factor (GM-CSF), which are highly associated with severe cytokine release syndrome (CRS), will be used to forecast CRS to allow doing earlier intervention, and CRS will be managed based on a revised CRS grading system. In addition, patients with grade 3 or 4 neurotoxicities or persistent B-cell aplasia will be treated with dexamethasone (10 mg intravenously every 6 hours) or IgG, respectively. Descriptive and analytical analyses will be performed.

Ethics And Dissemination: Ethical approval for the study was granted on 10 July 2014 (YLJS-2014-7-10). Written informed consent will be taken from all participants. The results of the study will be reported, through peer-reviewed journals, conference presentations and an internal organisational report.

Trial Registration Number: NCT02186860.
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http://dx.doi.org/10.1136/bmjopen-2016-013904DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5223707PMC
December 2016

First on-sky demonstration of the piezoelectric adaptive secondary mirror.

Opt Lett 2016 Dec;41(24):5712-5715

We propose using a piezoelectric adaptive secondary mirror (PASM) in the medium-sized adaptive telescopes with a 2-4 m aperture for structure and control simplification by utilizing the piezoelectric actuators in contrast with the voice-coil adaptive secondary mirror. A closed-loop experimental setup was built for on-sky demonstration of the 73-element PASM developed by our laboratory. In this Letter, the PASM and the closed-loop adaptive optics system are introduced. High-resolution stellar images were obtained by using the PASM to correct high-order wavefront errors in May 2016. To the best of our knowledge, this is the first successful on-sky demonstration of the PASM. The results show that with the PASM as the deformable mirror, the angular resolution of the 1.8 m telescope can be effectively improved.
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http://dx.doi.org/10.1364/OL.41.005712DOI Listing
December 2016

Comprehensive determination of polycyclic aromatic hydrocarbons in Chinese herbal medicines by solid phase extraction and gas chromatography coupled to tandem mass spectrometry.

Anal Bioanal Chem 2015 Mar 31;407(7):1989-97. Epub 2015 Jan 31.

Qinhuangdao Entry-Exit Inspection and Quarantine Bureau, Qinhuangdao, 066004, China.

A simple and highly sensitive gas chromatography-tandem mass spectrometry (GC-MS/MS) method combined with solid-phase extraction cleanup was established for the comprehensive determination of 16 Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in various kinds of Chinese herbal medicines (CHMs). A solid-phase extraction (SPE) purification strategy, including three parallel procedures, was developed depending on sample type, and satisfactory purification performances were achieved for all selected CHMs. The limits of detection ranged from 0.12 to 1.08 μg kg(-1) for the analyzed PAHs. The average recoveries were in the range of 65.9 % to 100.8 %, except for naphthalene (43.8 %-75.9 %), and the relative standard deviations were ≤12.8 %. The proposed method was successfully applied to the analysis of PAHs in 24 CHMs including five roots, three stems, four flowers, two fruits, four seeds, three leaves, and three barks. In the samples analyzed, all 16 PAHs are present. Their sum ranges from 21.1 to 2236.3 μg kg(-1). The entire procedure was shown to be effective and conveniently fast, and may serve as an alternative screening protocol for the determination of PAHs in CHMs.
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http://dx.doi.org/10.1007/s00216-015-8463-2DOI Listing
March 2015

Antioxidant effects of grape vine cane extracts from different Chinese grape varieties on edible oils.

Molecules 2014 Sep 23;19(9):15213-23. Epub 2014 Sep 23.

College of Enology, Northwest A&F University, Yangling 712100, Shaanxi, China.

This study involved the determination of the peroxide value (POV) as a measure of the resistance of the oxidation of edible oil with grape vine cane additives to assess their antioxidation potential. The study demonstrated that grape extracts of canes could effectively inhibit the lipid oxidation of edible oils and that this ability varied significantly due to the different extraction solvents employed, as well as to the different varieties of canes used. Lipid oxidation of edible oils was significantly reduced under an accelerated storage condition of 70 ± 1 °C in the presence of Vitamin C (VC), which was chosen as a synergist of grape vine cane extract. A 4:1 ratio of Victoria Blanc-ethyl acetate fraction (EAF) and VC led to a significant lowering of the peroxide value and indicated a better antioxidant effect. Thus, these results indicated that some varieties of grape vine cane extracts could be applied as natural antioxidants for elevation of the quality of edible oils in the food industry.
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http://dx.doi.org/10.3390/molecules190915213DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6270656PMC
September 2014

Multichannel-Hadamard calibration of high-order adaptive optics systems.

Opt Express 2014 Jun;22(11):13792-803

we present a novel technique of calibrating the interaction matrix for high-order adaptive optics systems, called the multichannel-Hadamard method. In this method, the deformable mirror actuators are firstly divided into a series of channels according to their coupling relationship, and then the voltage-oriented Hadamard method is applied to these channels. Taking the 595-element adaptive optics system as an example, the procedure is described in detail. The optimal channel dividing is discussed and tested by numerical simulation. The proposed method is also compared with the voltage-oriented Hadamard only method and the multichannel only method by experiments. Results show that the multichannel-Hadamard method can produce significant improvement on interaction matrix measurement.
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http://dx.doi.org/10.1364/OE.22.013792DOI Listing
June 2014

Simultaneous determination of 14 phenolic compounds in grape canes by HPLC-DAD-UV using wavelength switching detection.

Molecules 2013 Nov 18;18(11):14241-57. Epub 2013 Nov 18.

College of Enology, Northwest A&F University, Yangling 712100, Shaanxi, China.

The paper described a novel chromatographic method for the simultaneous determination of phenolic compounds such as gallic, protocatechuic, vanillic, caffeic, syringic, p-coumaric and salicylic acid, (+)-catechin, (‒)-epicatechin, rutin, morin, quercetin, coumarin and trans-resveratrol at their maximum absorbance wavelengths (MAW) employing reverse-phase high performance liquid chromatography combined with DAD and UV detection via detection wavelength switching. The method was based on MAW acquisition by DAD and quantification by UV. The separation process was performed on a Shim-Pack VP-ODS C18 column (250 mm × 4.6 mm, 5 μm) held at 30 °C, utilizing 3.0% acetic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL/min in the gradient elution mode. The method was fully validated in terms of linearity (r2 > 0.9990, 10‒350 mg/L), precision (both intra-day and inter-day RSD < 4.22%), accuracy (97.31%‒104.66%), specificity, robustness (0.59% < RSD < 2.86%), limit of detection and quantification. The switching method significantly improved the sensitivities of most phenolics studied in comparison with the standard constant wavelength detection (280 nm). The proposed method has been successfully applied to the determination of 14 phenolic compounds in 89 varieties of one-year-old Chinese grape one-year-canes. Grape canes contain many phenolics, especially trans-resveratrol, (‒)-epicatechin, and (+)-catechin.
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http://dx.doi.org/10.3390/molecules181114241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6269983PMC
November 2013

Morphology-controlled preparation and enhanced simulated sunlight and visible-light photocatalytic activity of Pt/Bi5Nb3O15 heterostructures.

Phys Chem Chem Phys 2013 Jun 25;15(21):8342-51. Epub 2013 Apr 25.

Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China.

Plate- and octahedron-like Pt/Bi5Nb3O15 heterostructures are controllably prepared by a hydrothermal treatment method combined with photodeposition in the presence of different surfactants, i.e., cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP). The composition, structure, morphology, optical absorption properties, and textural properties of as-prepared Pt/Bi5Nb3O15 are well-characterized, and their simulated sunlight and visible-light photocatalytic activity is evaluated by the degradation of two typical organic pollutants, i.e., methyl orange (MO) and p-nitrophenol (PNP). Special attention is paid to investigate and explain the influence of the morphologies on the photocatalytic activity of the heterostructured Pt/Bi5Nb3O15.
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http://dx.doi.org/10.1039/c3cp00084bDOI Listing
June 2013

Plasma and hepatic cholesterol-lowering effects of tomato pomace, tomato seed oil and defatted tomato seed in hamsters fed with high-fat diets.

Food Chem 2013 Aug 29;139(1-4):589-96. Epub 2013 Jan 29.

College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China.

The cholesterol-lowering effects of tomato pomace (TP), tomato seed oil (TSO) and defatted tomato seed (DTS) were determined in male Golden Syrian hamsters. Hamsters fed high-fat diets containing 10% TSO or 18% DTS were compared to a diet containing 10% corn oil and 10% microcrystalline cellulose (control 1), 42% TP were compared to 25% microcrystalline cellulose (control 2). TP, TSO and DTS reduced hepatic total cholesterol (TC) content. DTS also lowered plasma TC and low-density lipoprotein cholesterol (LDL-C) concentrations. Fecal excretion of lipid, bile acid and cholesterol increased in the DTS group compared to control 1. DTS-fed hamsters had higher levels of hepatic CYP7A1, CYP51, ABCB11, and ABCG5 gene expression than control, suggesting both hepatic bile acid and cholesterol synthesis increased due to increased fecal excretion of bile acid and cholesterol. The results suggest that protein, dietary fibre or phenolic compounds in DTS may be responsible for plasma cholesterol decrease.
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http://dx.doi.org/10.1016/j.foodchem.2013.01.043DOI Listing
August 2013