Search

High-quality hex meshes are crucial for finite element analysis. However, the quality of a hex mesh improved by geometric smoothing cannot guarantee to satisfy the requirement of finite element analysis. To this end, this paper puts forward an approach to topological optimization of hex mesh based on frame field and sheet operations, which improves the quality of the worst elements of the hex mesh by optimizing its topological structure. The approach first builds an initial frame field on the input hex mesh and optimizes it to obtain a high-quality frame field. Then, the problematic sheet that leads to the poor quality of the hex mesh is determined according to the initial and optimized frame fields. Finally, the structure of the problematic sheet is adjusted based on the high-quality frame field and sheet operations. Experimental results demonstrate that our topological optimization approach can effectively improve the minimal Scaled Jacobian value of the hex mesh. [ABSTRACT FROM AUTHOR]

Sheet inflation is an enhanced and more general version of the classic pillowing procedure [1] used to modify hexahedral meshes. The flexibility of sheet inflation makes it a valuable tool for hex mesh generation, modification and topology optimization. However, it is still difficult to generate self-intersecting sheet within a local region while assuring the mesh quality. This paper proposes an approach to achieving optimized complex sheet inflation under various constraints. The approach can generate complex sheets that intersect themselves more than once and maximize the quality of the resultant mesh. We successfully apply this approach to mesh matching and mesh boundary optimizing. [ABSTRACT FROM AUTHOR]

High quality hex mesh can be effectively generated based on the block structure of a solid model, but the existing approaches to block decomposition of the solid model are still far from the expectation. In this paper, we propose a new method of decomposing the solid model into the block structure based on sheet operations, which can guarantee the validity of the resultant block structure. The method firstly generates an initial hex mesh of the given solid model based on its tet mesh. Then, it inserts a number of global sheets on the boundary and inside the volume respectively by sheet inflation to make the hex mesh capture the geometry of the solid model. Finally our method determines the optimal sheet set that can be extracted based on quality prediction and extracts the sheet set as a whole to get the reasonable and valid block structure of the solid model. Experimental results show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Uncovering the underlying rules that determine efficiency and device stability of polymer donors is crucially important for future rational design of new materials. By reducing bulkiness of alkyl chain in NTI, we synthesized polymer donor PNTB-HD. The PNTB-HD:N3 based photovoltaic device exhibits the highest PCE of 18.15% that is among the best efficiency in binary devices. More encouragingly, it demonstrates much better device thermal stability than PNTB-2T and the most widely used polymer PM6. Compared with PNTB-2T, PNTB-HD has more condensed packing and stronger tendency to preassembly in chloroform solution that is reason for simultaneously enhancement of efficiency and thermal stability. Single crystal data further revealed reducing alkyl chain bulkiness in NTI could significantly enhance short interaction of C=O...H-C between adjacent molecules that provide useful information to understand the physical property variation of two polymers. This study revealed reducing steric hindrance around electronegative atom is an effective strategy for designing high-performance polymers donors. [Display omitted] • Reducing steric hindrance around electronegative atom strongly affect polymer' packing and aggregation properties. • The PNTB-HD:N3 based OSCs exhibits the highest PCE of 18.15 % that is among the best efficiency in binary devices. • The polymer PNTB-HD demonstrates much better device thermal stability than PNTB-2T and the polymer PM6. [ABSTRACT FROM AUTHOR]

The finite element mesh regeneration, which is usually required during the design model verification process, is time consuming. Mesh editing is a kind of efficient mesh regeneration technique. In this paper, a direct editing method for hexahedral mesh is proposed to achieve high quality and adaptive hexahedral mesh regeneration. After the user applies direct editing on the CAD model, effective mesh deformation and optimization are automatically conducted on the associated hexahedral mesh model. To optimize the deformed mesh, firstly, simplified fundamental sheet configuration conversions are applied to improve the boundary mesh quality; secondly, dual operations are carried out to insert/extract entire sheets; thirdly, according to the measurement of the hexahedron deformation, those mesh regions whose mesh sizes become not reasonable due to the deformation are coarsened and refined through localized dual operations. The proposed method can not only effectively achieve hexahedral mesh editing, but also facilitate the interoperation of CAD model and mesh model. [ABSTRACT FROM AUTHOR]

Abstract: Sagittaria natans (Alismataceae) is an endangered aquatic herb in China. The nuclear microsatellite (SSR) loci variation of the 11 extant populations of S. natans was investigated in the present study. A relative high level of genetic diversity was found in this species. The Wilcoxon’s signed rank tests did not indicate a recent bottleneck in any of the populations. The Analysis of molecular variance (AMOVA) showed a low level of population differentiation (FST = 0.284) among the populations of S. natans. This result was supported by STRUCTURE analysis (K = 1), the NJ analyses and Mantel test (r = −0.0221, p > 0.5). The genetic structure could be contributed to an earlier period of more pronounced gene flow when the species had a more continuous distribution. The results of this study could be used as the basis for conservation guidelines for the management of this endangered species in China. [Copyright &y& Elsevier]

This multicenter study assessed the efficacy and safety of transcatheter closure of perimembranous ventricular septal defect (VSD) using a modified double-disk occluder. In 5 different centers in China, 412 patients with VSD, including 202 men and 210 women, underwent attempted transcatheter closure. The age range was 3 to 65 years (mean 16.4 ± 9.1). The diameter of defect was 3 to 15 mm by transthoracic echocardiography and 3 to 18 mm by left ventriculography. The ratio of pulmonary to systemic flow varied from 1.6 to 2.3 (1.9 ± 0.4). The device diameter was 4 to 20 mm (7.09 ± 3.60). The ventricular septal rim below the aortic valve was 0 to 5 mm. The immediate success rate was 96.6%; 6 cases had third degree atrioventricular block and recovered within 3 weeks. None needed a permanent pacemaker. Dislodgement of the device occurred in 3 patients but the device was recaptured and redeployed in 2 cases. During the follow-up period of 2 years, there was no evidence of residual shunt and device-related complications. In conclusion, transcatheter closure of VSD is safe and effective in most selected patients; the mid-term prognosis of patients with transcatheter closure is good. [Copyright &y& Elsevier]

This study was designed to evaluate the sensitivities of diverse cell lines on DNA damage effects and genotoxic effects of three brominated flame retardants (BFRs) and three metal ions (Cu2+, Cd2+, Hg2+) by comet assay. First, THP-1 was identified as the most sensitive cell line in terms of DNA damage among 11 kinds of cells screened. Accordingly, the THP-1 cell line was used as a model in subsequent single/combined genotoxicity tests. Single exposure tests to BFRs or metal ions revealed that the DNA damage effects increased with increasing exposure concentration. In combined exposure tests, BFRs (at concentrations of 1/2 EC 50) were deployed in combination with different concentrations of Cu2+, Cd2+, or Hg2+. The results showed that the % tail DNA values were significantly increased by most mixtures. Our findings on combined toxic effects by comet assay provide valuable information for setting valid environmental safety evaluation standards. Image 1 • The sensitivity of diverse cell lines for DNA damage effects was different. • THP-1 was screened to be the most sensitive cell line by comet assay. • The mixture effects of BFRs and metals on DNA damage were significantly increased. • The combined toxicity should not be overlooked in environmental safety standards. [ABSTRACT FROM AUTHOR]

The monitoring of the arterial and exhaled CO 2 is of great importance. Despite of many reports on metal organic frameworks (MOFs) in adsorbing and separating CO 2 , the application of fluorescent MOFs probes for CO 2 detection was rarely reported. A new fluorescent MOF probe UIO-66-ONa for CO 2 detection was developed via post-synthesis of UIO-66-NH 2 through a Schiff base reaction with salicylaldehyde and further treatment with sodium hydroxide. This probe exhibited a remarkable fluorescence color change from green to blue and showed excellent sensitivity and selectivity for CO 2 sensing in solution. The detection limit was as low as 3.5 × 10−7 M. The excellent sensing performance of UIO-66-ONa was ascribed to the efficient reaction between sodium phenolic group and CO 2 , which led to the transformation of UIO-66-ONa to UIO-66-OH as evidenced by the emission spectra. This post-synthetic modification idea provided a new strategy for designing fluorescent MOFs probes for CO 2 detection. A new fluorescent metal organic framework probe (UIO-66-ONa) exhibits the excellent sensing performance towards CO 2 detection as the interaction between sodium phenolic group and CO 2 , the detection limit is 3.5 × 10−7 M. Image 1 • A new fluorescent MOF probe (UIO-66-ONa) for CO2 detection was developed via post-synthesis of UIO-66-NH2. • UIO-66-ONa exhibits excellent selectivity, sensitivity and reusability for CO2 detection in solution. • A promising design strategy for the synthesis of high efficient fluorescent MOFs for gas sensing. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) have been hotly concerned due to their unique structure and properties. A new highly fluorescent MOF was developed via post-synthesis of UIO-66-NH 2 through an efficient click reaction with 1-ethynylpyrene for the 2,4,6-trinitrophenol (PA) detection which named UIO-66-Py. It exhibited a significantly enhanced fluorescence intensity than UIO-66-NH 2 and showed excellent selectivity and sensitivity for sensing PA in solution via the fluorescence quenching mechanism. The UIO-66-Py showed an 85% fluorescence quenching efficiency with 0.203 mM PA and the detection limit was 4.5 × 10−7 M. The excellent selectivity of the probe was ascribed to the hydrogen bond interaction between UIO-66-Py and PA as evidenced by FT-IR. The hydrogen bond interaction promoted the photo-induced electron transfer (PET) between UIO-66-Py and PA which leading to the better selectivity of UIO-66-Py for PA detection over TNT. This post-synthetic modification idea provided a strategy for the development of MOFs with multifunctional sensing. A new highly fluorescent metal organic framework probe (UIO-66-Py) exhibits the excellent selectivity and sensitivity towards PA detection as the hydrogen bonding interaction and hence an efficient photo-induced electron transfer, the detection limit of PA is 4.5 × 10−7 M. Image 1 • A new fluorescent MOF probe (UIO-66-Py) was obtained via post-synthesis through an click reaction for PA detection. • UIO-66-Py exhibits an excellent selectivity and sensitivity to PA in THF, the detection limit of PA is 4.5 × 10−7 M. • A promising design strategy for the synthesis of high efficient fluorescent MOFs for dangerous chemical detection. [ABSTRACT FROM AUTHOR]

Studies have shown that functional abnormalities in the locus coeruleus (LC) are strongly associated with depressive symptoms, but the pattern of LC functional connectivity in Alzheimer's disease patients with depressive symptoms (D-AD) remains unclear. The current study aimed to investigate the characteristics of LC functional connectivity (FC) in D-AD using resting-state functional magnetic resonance imaging (rsfMRI). We obtained rsfMRI data in 24 D-AD patients (aged 66–76 years), 14 non-depressive AD patients (nD-AD) (aged 69–79 years) and 20 normal controls (aged 67–74 years) using a 3 T scanner. We used the FC approach to investigate abnormalities in the LC brain network of D-AD patients. One-way ANCOVA and post-hoc two-sample t -tests were performed to compare the strength of functional connectivity from the LC among the three groups. Our results showed that, compared with normal controls, D-AD showed decreased left LC FC with the right caudate and left fusiform gyrus, whereas nD-AD showed decreased left LC FC with the right caudate, right middle frontal gyrus and left fusiform gyrus. Compared to nD-AD, D-AD showed increased left LC FC with right superior frontal gyrus and right precentral gyrus. These findings contribute to our understanding of the neural mechanisms of D-AD. • The locus coeruleus is the main nucleus for the synthesis of the neurotransmitters norepinephrine and dopamine in the brain. • The current study investigates the brain network of the locus coeruleus in depressed Alzheimer's patients. • The differential brain regions are located in the caudate, middle frontal gyrus, precentral gyrus and fusiform gyrus. • These findings contribute to our understanding of the neural mechanisms in depressed AD patients. [ABSTRACT FROM AUTHOR]

High quality hex mesh can be effectively generated based on a block structure of a solid model, but existing approaches to block decomposition of the solid model are still far from expectations. In this paper, we propose a new method to decompose the solid model into a block structure using sheet operations, which guarantees the validity of the resulting block structure. The method first generates an initial hex mesh of a given solid model based on its tet mesh. Then, a number of fundamental sheets and high-quality curve-related sheets are inserted on the boundary and inside the initial hex mesh respectively by sheet inflation to capture the geometry of the solid model. Finally, a reasonable and valid block structure for the solid model is obtained by extracting all of the original sheets as a whole as well as an optimal deletable sheet set determined by quality prediction. Experimental results prove the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A novel and facile method that magnetic carboxymethyl chitosan aerogel (Fe 3 O 4 @PDA/CMC) has been developed with the combination of mussel-inspired chemistry and Schiff base reaction to remove cation and anion dyes. The resulted aerogel were systematically characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), N 2 adsorption–desorption, and point of zero charge (pH pzc). Diverse factors affecting adsorption behavior such as pH, contact time, adsorbent dosage, initial concentration, ionic strength of dyes was investigated. The kinetic results show that the adsorption process can be well described by the pseudo-second-order. The Langmuir isotherm model can fit the equilibrium data well. The thermodynamic analyses show that the adsorption of cation and anion dyes onto Fe 3 O 4 @PDA/CMC aerogel is endothermic and spontaneous. In this study, the obtained Fe 3 O 4 @PDA/CMC aerogel is a simple, facile and environmentally friendly procedure which involves non-toxic organic solvent. The designed magnetic aerogel exhibited an excellent recyclability and removal efficiency after seven adsorption-desorption cycles. In this study, a facile method that the magnetic carboxymethyl chitosan (Fe3O4@PDA/CMC) aerogel been fabricated through the combination of mussel-inspired chemistry and Schiff base reaction to remove dyes. Image 1 • A multifunctional magnetic carboxymethyl chitosan (Fe 3 O 4 @PDA/CMC) aerogel was successfully fabricated as an adsorbent. • The aerogel had a high adsorption capacity for cation dyes (MB, CV) and anion dyes (MO, CR). • The preparation process was feasible, facile, and eco-friendly. • The adsorption kinetics, isotherms, thermodynamics, and mechanisms were studied in detail. • It can be efficiently regenerated and reused with a magnet over seven cycles. [ABSTRACT FROM AUTHOR]

• Propose a theoretical prediction model for ballistic limit of HFRPT. • Discover the hybridization effects on the variation of failure modes of HFRPT. • Reveal the effect of stacking sequences and layer thicknesses on the impact energy absorption of HFRPT. • Propose an optimal design for a 10 mm thick HFRPT composed of AF and CFRP. Fiber reinforced polymer and its hybrid composites are widely used in bulletproof production. The ballistic limit, failure mode and energy absorption of a hybrid fiber reinforced polymer target (HFRPT) composed of carbon fiber reinforced polymer (CFRP) and aramid fiber composite (AF) were studied in this paper. A finite element model was formulated to investigate the hybridization effect of layer thickness and stacking sequence on the ballistic behavior. A theoretical method was proposed to predict the ballistic limits of HFRPT, demonstrating an error percentage of less than 10% in most of the hybridization. Four typical failure modes including compression failure, tensile failure, shear plugging failure and tension shear coupling failure were observed in HFRPT, and the influence of hybridization on the alternations of failure modes was observed. Additionally, the effect of stacking sequences and layer thickness on energy absorption of HFRPT was examined. For the HFRPTs with a total thickness of 10 mm, the AF/CFRP hybridization proves to offer better ballistic impact resistance performance than the CFRP/AF hybridization. The HFRPT with a stacking sequence of 9 mm AF and 1 mm CFRP achieves a maximum ballistic limit of 420 m/s and the highest impact energy areal density ratio of 323 J/(g/cm2). [ABSTRACT FROM AUTHOR]

High-quality hex meshes are crucial for finite element analysis. However, geometric smoothing techniques applied for improving the quality of a hex mesh cannot ensure that the requirements of finite element analysis are satisfied. Therefore, to address this challenge, in this paper, we present a novel approach for topological optimization of a hex mesh based on frame field and sheet adjustment. Our approach improves the quality of the worst elements of the hex mesh by optimizing its topological structure. The approach first builds an initial frame field from the input hex mesh and then optimizes it to obtain a resultant high-quality frame field. Next, according to the initial and optimized frame fields, the process determines the most problematic sheet that degrades the quality of the hex mesh. Finally, based on the high-quality frame field and the current topological structure of the hex mesh, our approach uses sheet operations to adjust the structure of this most problematic sheet. Experimental results demonstrate that our topological optimization approach can effectively improve the minimum Scaled Jacobian value of the hex mesh. [ABSTRACT FROM AUTHOR]

To facilitate automatic and high-quality hexahedral meshing of complex 3D product models, a pseudo-swept volume decomposition approach is proposed in this paper, which can automatically decompose a complex solid model into a set of sub-volumes, including all of the pseudo-swept volumes. First, the sweep directions and faces of potential pseudo-swept volumes are recognized using a fuzzy clustering algorithm. Then, all of the interacting potential pseudo-swept volumes are separated by the recursive construction of optimized cutting face sets, with the solid model decomposed at the same time. In particular, the pseudo-swept volumes resulting from our approach are suitable for high-quality hexahedral meshing. The efficiency and effectiveness of this approach are demonstrated by several experimental results. [ABSTRACT FROM AUTHOR]

Anaplastic thyroid carcinoma (ATC) was a rare and extremely malignant endocrine cancer. Recently, dysregulation of circadian rhythm genes was demonstrated to play an essential role in tumor progression, while its exact role and mechanism in ATC remained poorly clear. 4 ATC-related datasets were integrated to screen for differentially expressed circadian rhythm genes (DE-CRGs). Thereafter, Multiscale Embedded Gene Co-expression Network Analysis (MEGENA) and network enrichment analysis were conducted to investigate the dynamic characteristics of circadian rhythm genes. Next, Lasso-logistic model and immunohistochemistry were applied for determining the candidates. Finally, cell biological experiments and gene set enrichment analysis (GSEA) were used to confirm the roles of NPAS2 in ATC. 25 DE-CRGs were firstly identified in ATC. These DE-CRGs mainly regulated mitotic nuclear division, cytokinesis and DNA replication signals. Notably, NPAS2, CSNK1E, NAMPT, TYMS, SERPINE1, TOP2A, JUN, EGR3 and HEBP1 were identified as the dynamic signature in the malignant progression of ATC, which were confirmed by prognostic analysis. Furthermore, NPAS2 was found to be significantly up-regulated in ATC through clinical samples and cell experiments. Silencing NPAS2 effectively inhibited the proliferation, migration and invasion of ATC cells. GSEA showed that high expression of NPAS2 was mainly associated with cell cycle and focal adhesion, and silencing of NPAS2 suppressed these signals in our experiments. In summary, we found a dynamic 9-DE-CRGs signature in ATC. And the aberrant expression of NPAS2 drove the malignant phenotypes of ATC, which facilitated to deepen our understanding of the roles of circadian rhythm genes in ATC. • Circadian rhythm genes drives anaplastic thyroid carcinoma malignant progression. • A dynamic 9-DE-CRGs signature in ATC is identified in the malignant progression of ATC. • NPAS2 regulates cell cycle and focal adhesion signaling to promote ATC progression. [ABSTRACT FROM AUTHOR]

[Display omitted] • Explored hypoglycemic, hypolipidemic and anti-inflammatory effects of lotus leaves. • Screened out and identified top four bioactive ligands in lotus leaves. • Promoted the glucose consumption of Hep G2 cells with lotus leaves. • Verified good bioactivities of N -nornuciferine in vitro. • Revealed the interactions between four ligands and three target enzymes. Leaf of Nelumbo nucifera Gaertn. (N. nucifera) has been widely used as the main ingredient in lipid-lowering herbal teas and some prescriptions in China due to their excellent hypoglycemic and hypolipidemic effects. However, the active components responsible for these beneficial properties and their mechanisms remain unexplored. In this work, the N. nucifera leaf extracts significantly promoted the glucose consumption of HepG2 cells, and also exhibited remarkable inhibitory activities against α-glucosidase, pancreatic lipase, and COX-2. Furthermore, the top four potential active compounds (N -nornuciferine, Nuciferine, 2-Hydroxy-1-methoxyaporphine, and Isorhamnetin 3-O-glucoside) targeting the above three enzymes were screened out by bioaffinity ultrafiltration with multiple targets coupled with HPLC-MS/MS. The enzyme inhibitory activities of candidate compounds were verified by enzyme inhibition assay and molecular docking. In addition, molecular docking revealed the binding information between the candidate molecules and enzymes. The current study provided valuable information in discovering functional active ingredients from complex medicinal plant extracts. [ABSTRACT FROM AUTHOR]

Abstract: We used methylation-sensitive amplified polymorphisms (MSAP) to examine the alterations of cytosine methylation in two contrasting growth types of an amphibious plant Alternanthera philoxeroides in response to change of water availability. Using 34 pairs of selective primer combinations, we amplified 1026 and 1128 clear and reproducible bands in root and leaf of A. philoxeroides, respectively. When the aquatic types of plants were transplanted into drought culture, we found a decrease in the overall DNA methylation. When the terrestrial types of plants were transferred into flood culture, we detected a higher frequency of methylation than demethylation events. Alterations of DNA methylation were more evident in root than in leaf in response to change of water availability. When the confounding effects of variable environmental factors were removed, differences of cytosine methylation profiles were observed between two growth types of plants under common growth conditions. [Copyright &y& Elsevier]

• 108 UGT genes were characterized in lotus (Nelumbo). • Whole-genome and tandem duplication events contribute to NnUGT family expansion. • Lotus UGT family members display functional divergence. • Some key NnUGT genes might involve in lotus ecotypic differentiation. Family-1 UDP-glycosyltransferases, designated as UGTs, glycosylate key cellular metabolites into compounds with improved stability, solubility and transport to regulate plant growth and development in various metabolic pathways. However, little is known about the molecular and functional characteristics of UGT family in an aquatic plant and how it contributes to the Nelumbo nucifera ecotypic differentiation. Therefore, we performed a genome-wide investigation of 108 candidate UGT genes distributing on all eight lotus chromosomes, encompassing 16 distinct phylogenetic groups (A–P). These UGT groups feature different molecular weights, subcellular localizations and evolutionary rates. Intra-specific collinearity analysis further suggests that the expansion of the UGT family in lotus is mainly driven by tandem duplication and whole-genome duplication. Further, expression analysis of 54 RNA-seq samples from ten different lotus tissues suggests that expression of most UGT family members exhibits tissue or developmental-stage specificity, and UGTs expressed in reproductive organs (tissues) evolve much faster than those expressed in vegetative organs. More interestingly, key UGT genes being differentially regulated between temperate and tropical lotus (ecotypes) were uncovered during the seedling stage, indicating that UGTs associated with hormone synthesis and transport likely contribute to early differentiation between lotus ecotypes. Overall, our systematic expression and evolutionary analyses not only characterize the expression, functional diversity and evolutionary dynamics of the UGT family in an aquatic plant but also provide insight into the roles of the UGT family underlying the differentiation of the lotus ecotypes. [ABSTRACT FROM AUTHOR]