Zhong Chen

Bio: Zhong Chen is an academic researcher from Nanyang Technological University. The author has contributed to research in topics: Medicine & Chemistry. The author has an hindex of 80, co-authored 1000 publications receiving 28171 citations. Previous affiliations of Zhong Chen include Institute of High Performance Computing Singapore & National Institute of Education.

Mechanisms regulating transitory suppressive activity of neutrophils in newborns: PMNs‐MDSCs in newborns

Abstract: Transitory appearance of immune suppressive polymorphonuclear neutrophils (PMNs) defined as myeloid‐derived suppressor cells (PMNs‐MDSCs) in newborns is important for their protection from inflammation associated with newly established gut microbiota. Here, we report that inhibition of the type I IFN (IFN1) pathway played a major role in regulation of PMNs‐MDSCs‐suppressive activity during first weeks of life. Expression of the IFN1 receptor IFNAR1 was markedly lower in PMNs‐MDSCs. However, in newborn mice, down‐regulation of IFNAR1 was not sufficient to render PMNs immune suppressive. That also required the presence of a positive signal from lactoferrin via its receptor low‐density lipoprotein receptor‐related protein 2. The latter effect was mediated via NF‐κB activation, which was tempered by IFN1 in a manner that involved suppressor of cytokine signaling 3. Thus, we discovered a mechanism of tight regulation of immune suppressive PMNs‐MDSCs in newborns, which may be used in the development of therapies of neonatal pathologies.

High-resolution 2-D NMR spectroscopy based on the Radon transform and pure shift technique for studying chemical shifts perturbations.

Abstract: Chemical shift plays an important role in molecular analysis. However, chemical shifts are influenced by temperature, solvent concentration, pressure, and so forth. Therefore, measuring chemical shift perturbations caused by these factors is helpful to molecular studies. A new form of 2-D spectroscopy (projection spectroscopy) has been introduced whose indirect dimension is derived by implementing the Radon transform on a series of conventional 1-D proton spectra and indicates such perturbations. However, signal overlap may exist in the conventional 1-D spectra and hence in the resulting projection spectra, hampering clear multiplet analysis and accurate extraction of perturbations. Here, the pure shift decoupling technique is employed to obtain clearer projection spectrum with higher spectral resolution. The combination of pure shift technique and the Radon transform is helpful to accurately extract chemical shift perturbations. It is believed that this application will open up a vast prospect for molecular analysis.

Influence of Urban Road Green Belts on Pedestrian-Level Wind in Height-Asymmetric Street Canyons

Abstract: This study was conducted to examine the effect on airflow of the shape of an urban road green belt in an asymmetrical street canyon. In this paper, the airflow field at pedestrian height in an asymmetrical street with different building height ratios (ASF) on both sides of the street is modeled and simulated using computational fluid dynamics (CFD) software, ANSYS FLUENT, and the flow rate characteristic distribution index and the average airflow intensity index are used to evaluate and analyze the airflow at the pedestrian level. The study shows that: (1) in an empty street scheme with different building ratios, the static wind area is located on the roof of the downstream building; the closer to the ground in a street with an ASF = 1/3, the lower the airflow rate. However, the situation is the opposite of that in other streets (2/3, 3/1, and 3/2). (2) The position of the green belt makes the windward side flow rate in the step-up street higher than that of the leeward side, and the flow rate of the leeward side in the step-down street is higher than that of the windward side. (3) Compared with other green belt forms, the use of two plates and three belts in the incremental street can increase the circumferential sinking at the roofs of the windward side of the street, thereby improving the wind environment in the entire street. The use of one plate, two-belt and three-plate, four-belt scenarios in the step-down street allows the two ends of the corner vortex to carry more airflow into the interior of the street and reduces both the “wind shadow effect” area in the middle of the street and the “air outlet effect” at both ends.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Principles of Neural Science

Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...