A large scale simulation of floe-ice fractures and validation against full-scale scenario

Wenjun Lu,Hans-Martin Heyn,Raed Lubbad,Sveinung Loset 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

While interacting with a sloping structure, an ice floe may fracture in different patterns. For example, it can be local bending failure or global splitting failure depending on the contact properties, geometry and confinement of the ice floe. Modelling these different fracture patterns as a natural outcome of numerical simulations is rather challenging. This is mainly because the effects of crack propagation, crack branching, multi fracturing modes and eventual fragmentation within a solid material are still questions to be answered by the on-going research in the Computational Mechanic community. In order to simulate the fracturing of ice floes with arbitrary geometries and confinement; and also to simulate the fracturing events at such a large scale yet with sufficient efficiency, we propose a semi-analytical/ empirical and semi-numerical approach; but with focus on the global splitting failure mode in this paper. The simulation method is validated against data we collected during the Oden Arctic Technology Research Cruise 2015 (OATRC2015). The data include: 1) camera images based on which we specify the exact geometry of ice floes before and after an impact and fracturing event; 2) IMU data based on which the global dynamic force encountered by the icebreaker is extracted for the impact event. It was found that this method presents reasonably accurate results and realistic fracturing patterns upon given ice floes.

A large scale simulation of floe-ice fractures and validation against full-scale scenario

Lu, Wenjun,Heyn, Hans-Martin,Lubbad, Raed,Loset, Sveinung The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

While interacting with a sloping structure, an ice floe may fracture in different patterns. For example, it can be local bending failure or global splitting failure depending on the contact properties, geometry and confinement of the ice floe. Modelling these different fracture patterns as a natural outcome of numerical simulations is rather challenging. This is mainly because the effects of crack propagation, crack branching, multi fracturing modes and eventual fragmentation within a solid material are still questions to be answered by the on-going research in the Computational Mechanic community. In order to simulate the fracturing of ice floes with arbitrary geometries and confinement; and also to simulate the fracturing events at such a large scale yet with sufficient efficiency, we propose a semi-analytical/empirical and semi-numerical approach; but with focus on the global splitting failure mode in this paper. The simulation method is validated against data we collected during the Oden Arctic Technology Research Cruise 2015 (OATRC2015). The data include: 1) camera images based on which we specify the exact geometry of ice floes before and after an impact and fracturing event; 2) IMU data based on which the global dynamic force encountered by the icebreaker is extracted for the impact event. It was found that this method presents reasonably accurate results and realistic fracturing patterns upon given ice floes.

Intercalation of Europium Inclusion Complex of β-Cyclodextrin into Layered Double Hydroxides Through Layer-By-Layer Assembly and Its Luminescent Properties

Wenjun Zhang,Yi Chen,Yanlin Li,Sumin Guan,Yan Chen,Qian-Qian Yang,Lu Liu,Qing-Chen Xue,Yu-Cui Guang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

"In this work, organic–inorganic hybrid ultrathin transparent films (UTFs), produced by layer-by-layer (LBL) assembly of the europium inclusion complex of β-cyclodextrin ( β-CD) and Mg–Al layered double hydroxide (MgAl–NO3–LDHs) nanosheets, are reported. UV-visible (UV-Vis) absorption and fluorescence spectroscopy show orderly growth of the europium inclusion complex of β-CD/layered double hydroxide (EICC/LDH) films with an increasing number of deposition cycles. X-ray diffraction and scanning electron microscopy measurements indicate that the films feature periodic layered structures with uniform surface morphology. Moreover, when EICC is assembled with inorganic rigid LDH nanosheets, the lifetimes are prolonged due to the isolation effect, and the UTFs are transparent with high brightness, which indicate that these films could serve as new optical materials."

TET2 Regulates 5-Hydroxymethylcytosine Signature and CD4+ T-Cell Balance in Allergic Rhinitis

Tan Lu,Fu Lisheng,Zheng Li,Fan Wenjun,Tan Hanyu,Tao Zezhang,Xu Yu 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.2

Purpose: Previous studies have shown the role of ten-eleven translocation 2 (TET2) in CD4+ T cells. However, its function in CD4+ T cells under allergic inflammation is unclear. We aimed to investigate the epigenomic distribution of DNA 5-hydroxymethylcytosine (5hmC) and the role of TET2 in CD4+ T cells of allergic rhinitis (AR). Methods: The hMeDIP-seq was performed to identify sequences with 5hmC deposition in CD4+ T cells of AR patients. Tet2-deficient or wild type mice were stimulated with ovalbumin (OVA) to develop an AR mouse model. The histopathology in nasal mucosae, Th1/Th2/Treg/Th17 cell percentage, concentrations of Th-related cytokines, expression of Tet and differential hydroxymethylated genes (DhMG), and the global deposition of 5hmC in sorted CD4+ T cells were detected. Results: Epigenome-wide 5hmC landscape and DhMG in the CD4+ T cells of AR patients were identified. Tet2 depletion did not led to spontaneous inflammation. However, under the stimulation of allergen, OVA, loss of Tet2 resulted in the exacerbation of allergic inflammation, which was characterized by severer allergic symptoms, more inflammatory cells infiltrating the nasal lamina propria, sharper imbalances between Th1/Th2 and Treg/Th17 cells, and excessive secretion of OVA-specific IgE and Th2-related cytokines. Moreover, altered mRNA production of several DhMG and sharp decrease in 5hmC deposition were also observed in Tet2-deficient OVA-exposed mice. Conclusions: TET2 may regulate DNA 5hmC, DhMG expressions, and CD4+ T cell balance in AR.

Phosphodiesterase 4D contributes to angiotensin II-induced abdominal aortic aneurysm through smooth muscle cell apoptosis

Gao Ran,Guo Wenjun,Fan Tianfei,Pang Junling,Hou Yangfeng,Feng Xiaohang,Li Bolun,Ge Weipeng,Fan Tianhui,Zhang Tiantian,Lu Jiakai,Jing He,Jin Mu,Yan Chen,Wang Jing 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Abdominal aortic aneurysm (AAA) is a permanent expansion of the abdominal aorta that has a high mortality but limited treatment options. Phosphodiesterase (PDE) 4 family members are cAMP-specific hydrolyzing enzymes and have four isoforms (PDE4A-PDE4D). Several pan-PDE4 inhibitors are used clinically. However, the regulation and function of PDE4 in AAA remain largely unknown. Herein, we showed that PDE4D expression is upregulated in human and angiotensin II-induced mouse AAA tissues using RT-PCR, western blotting, and immunohistochemical staining. Furthermore, smooth muscle cell (SMC)-specific Pde4d knockout mice showed significantly reduced vascular destabilization and AAA development in an experimental AAA model. The PDE4 inhibitor rolipram also suppressed vascular pathogenesis and AAA formation in mice. In addition, PDE4D deficiency inhibited caspase 3 cleavage and SMC apoptosis in vivo and in vitro, as shown by bulk RNA-seq, western blotting, flow cytometry and TUNEL staining. Mechanistic studies revealed that PDE4D promotes apoptosis by suppressing the activation of cAMP-activated protein kinase A (PKA) instead of the exchange protein directly activated by cAMP (Epac). Additionally, the phosphorylation of BCL2-antagonist of cell death (Bad) was reversed by PDE4D siRNA in vitro, which indicates that PDE4D regulates SMC apoptosis via the cAMP-PKA-pBad axis. Overall, these findings indicate that PDE4D upregulation in SMCs plays a causative role in AAA development and suggest that pharmacological inhibition of PDE4 may represent a potential therapeutic strategy.

Numerical Investigation of Supersonic Lateral Jet Interaction for Subsonic Projectiles with Different Fins at Large Angle of Attack

Xiao Wang,Ruyi Tao,Wenjun Ruan,Hao Wang,Dongjian Su,Xinggan Lu 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.2

Detached Eddy Simulation is used to study the interaction flowfields of a supersonic lateral jet penetrating into the crossflow of projectiles with cruciform or X-type fin configurations at Ma=0.3 and α=0∘,30∘∼60∘. For α=0∘, typical flow structures such as barrel shock, Mach disk and counter-rotating vortex pair(CVP) induced from the jet orifice are observed. Asymmetrical flowfields downstream of the jet for α=30∘ are analyzed, as well as the pressure distribution on the surfaces of all the projectiles. The reason why the CVP mentioned above disappears in this condition is also proposed. The variations of the normal forces acting on these projectiles are pointed out. The investigations into the amplification factor and the control efficiency of the jet force show that X-type fin configuration is more beneficial to maintain attitude for projectiles at large angle of attack.

Identification of pathways and genes associated with cerebral palsy

Qingwen Zhu,Yufei Ni,Jing Wang,Honggang Yin,Qin Zhang,Lingli Zhang,Wenjun Bian,Bo Liang,Lingyin Kong,Liming Xuan,Naru Lu 한국유전학회 2018 Genes & Genomics Vol.40 No.12

Cerebral palsy (CP) is a non-progressive neurological disease, of which susceptibility is linked to genetic and environmental risk factors. More and more studies have shown that CP might be caused by multiple genetic factors, similar to other neurodevelopmental disorders. Due to the high genetic heterogeneity of CP, we focused on investigating related molecular pathways. Ten children with CP were collected for whole-exome sequencing by next-generation sequencing (NGS) technology. Customized processes were used to identify potential pathogenic pathways and variants. Three pathways (axon guidance, transmission across chemical synapses, protein–protein interactions at synapses) with twenty-three genes were identified to be highly correlated with CP. This study showed that the three pathways associated with CP might be the molecular mechanism of pathogenesis. These findings could provide useful clues for developing pathway-based pharmacotherapies. Further studies are required to confirm potential roles for these pathways in the pathogenesis of CP.

Development of a multiplex qRT-PCR assay for detection of African swine fever virus, classical swine fever virus and porcine reproductive and respiratory syndrome virus

Yating Chen,Kaichuang Shi,Huixin Liu,Yanwen Yin,Jing Zhao,Feng Long,Wenjun Lu,Hongbin Si 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.6

Background: African swine fever virus (ASFV), classical swine fever virus (CSFV), and porcine reproductive and respiratory syndrome virus (PRRSV) are still prevalent in many regions of China. Co-infections make it difficult to distinguish their clinical symptoms and pathological changes. Therefore, a rapid and specific method is needed for the differential detection of these pathogens. Objectives: The aim of this study was to develop a multiplex real-time quantitative reverse transcription polymerase chain reaction (multiplex qRT-PCR) for the simultaneous differential detection of ASFV, CSFV, and PRRSV. Methods: Three pairs of primers and TaqMan probes targeting the ASFV p72 gene, CSFV 5′ untranslated region, and PRRSV ORF7 gene were designed. After optimizing the reaction conditions, including the annealing temperature, primer concentration, and probe concentration, multiplex qRT-PCR for simultaneous and differential detection of ASFV, CSFV, and PRRSV was developed. Subsequently, 1,143 clinical samples were detected to verify the practicality of the assay. Results: The multiplex qRT-PCR assay could specifically and simultaneously detect the ASFV, CSFV, and PRRSV with a detection limit of 1.78 × 100 copies for the ASFV, CSFV, and PRRSV, but could not amplify the other major porcine viruses, such as pseudorabies virus, porcine circovirus type 1 (PCV1), PCV2, PCV3, foot-and-mouth disease virus, porcine parvovirus, atypical porcine pestivirus, and Senecavirus A. The assay had good repeatability with coefficients of variation of intra- and inter-assay of less than 1.2%. Finally, the assay was used to detect 1,143 clinical samples to evaluate its practicality in the field. The positive rates of ASFV, CSFV, and PRRSV were 25.63%, 9.36%, and 17.50%, respectively. The co-infection rates of ASFV+CSFV, ASFV+PRRSV, CSFV+PRRSV, and ASFV+CSFV+PRRSV were 2.45%, 2.36%, 1.57%, and 0.17%, respectively. Conclusions: The multiplex qRT-PCR developed in this study could provide a rapid, sensitive, specific diagnostic tool for the simultaneous and differential detection of ASFV, CSFV, and PRRSV.

Integrated omics approaches to characterize a nuclear receptor corepressor-associated histone deacetylase in mouse skeletal muscle

Gong, Yingyun,Cao, Rui,Ding, Guolian,Hong, Sungguan,Zhou, Wenjun,Lu, Wenyun,Damle, Manashree,Fang, Bin,Wang, Chuhan C.,Qian, Justin,Lie, Natasha,Lanzillotta, Cristina,Rabinowitz, Joshua D.,Sun, Zheng Elsevier 2018 Molecular and cellular endocrinology Vol.471 No.-

<P><B>Abstract</B></P> <P>Nuclear receptors regulate gene expression by differentially binding to coactivators or corepressors in a ligand-dependent manner, which further recruits a set of epigenome-modifying enzymes that remodel chromatin conformation. Histone acetylation is a major epigenomic change controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDAC3 is the only HDAC that confers the enzymatic activity to the complexes nucleated by nuclear receptor corepressors NCoR and SMRT. To address the metabolic function of HDAC3, we have deleted it specifically in mouse skeletal muscles. We have performed the following omics profiling in skeletal muscles of these mice: (1) RNA-seq profiling of total RNA; (2) Global nuclear run-on (GRO-seq) analysis of nascent RNAs; (3) Chromatin immuno-precipitation (ChIP-seq) of HDAC3 at both early evening and early morning; (4) proteomics profiling with mass spectrometry; (5) snap-shot metabolomics profiling of water-soluble metabolites at the basal condition; (6) snap-shot metabolomics profiling of lipid species at the basal condition; (7) kinetic fluxomics analysis of glucose utilization using <SUP>13</SUP>C<SUB>6</SUB>-glucose <I>In vivo</I> during treadmill running exercise. These approaches have provided several novel insights into how nuclear receptors regulate circadian rhythm of skeletal muscle fuel metabolism, which has been published elsewhere. Here we present the original datasets and technical details during the execution, analysis, and interpretation of these omics studies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A mouse model with skeletal muscle-specific KO of HDAC3. </LI> <LI> <I>in vivo</I> RNA-seq, GRO-seq, and ChIP-seq identified relevance to circadian clock. </LI> <LI> Total proteome profiling in muscle samples. </LI> <LI> Metabolomics profiling identified disruption of BCAAs metabolism. </LI> <LI> Fluxomics with <SUP>13</SUP>C-glucose <I>in vivo</I> during treadmill running. </LI> </UL> </P>

Ultralarge elastic deformation of nanoscale diamond

Banerjee, Amit,Bernoulli, Daniel,Zhang, Hongti,Yuen, Muk-Fung,Liu, Jiabin,Dong, Jichen,Ding, Feng,Lu, Jian,Dao, Ming,Zhang, Wenjun,Lu, Yang,Suresh, Subra American Association for the Advancement of Scienc 2018 Science Vol.360 No.6386

<P>Diamonds have substantial hardness and durability, but attempting to deform diamonds usually results in brittle fracture. We demonstrate ultralarge, fully reversible elastic deformation of nanoscale (similar to 300 nanometers) single-crystalline and polycrystalline diamond needles. For single-crystalline diamond, the maximum tensile strains (up to 9%) approached the theoretical elastic limit, and the corresponding maximum tensile stress reached similar to 89 to 98 gigapascals. After combining systematic computational simulations and characterization of pre- and postdeformation structural features, we ascribe the concurrent high strength and large elastic strain to the paucity of defects in the small-volume diamond nanoneedles and to the relatively smooth surfaces compared with those of microscale and larger specimens. The discovery offers the potential for new applications through optimized design of diamond nanostructure, geometry, elastic strains, and physical properties.</P>