Multi-Objective Optimization of a Multi-Cavity, Significant Wall Thickness Difference Extrusion Profile Mold Design for New Energy Vehicles.

With the rapid development of the new energy vehicle market, the demand for extruded profiles for battery trays, mainly characterized by significant wall thickness differences in multiple chambers, is increasing, posing new challenges to production and quality control. This study examines the multi-objective optimization problem in the design process of aluminum profile dies with multi-cavity profiles and significant wall thickness differences. Using QFORM-extrusion professional aluminum extrusion finite element analysis software and the response surface analysis method, the standard deviation of the velocity (SDV), standard deviation of the pressure (SDP), and thick wall hydrostatic pressure (TWHP) on the profile section at the die exit are optimized. By analyzing the functional relationship between the key die structure parameters (the height of the baffle plates, the length of the bearing, and the height of the false mandrel) and the optimization objective, the optimal combination scheme of die structure parameters was obtained using the NSGA2 (non-dominated sorting genetic algorithm-2) multi-objective genetic optimization algorithm. The results show that, compared with the initial design scheme, the standard deviation of profile section velocity was reduced by 5.33%, the standard deviation of pressure was reduced by 11.16%, and the thick wall hydrostatic pressure was increased by 26.47%. The die designed and manufactured using this scheme successfully completed the hot extrusion production task, and the profile quality met the predetermined requirements, thus verifying the effectiveness of this study in optimizing the design of a multi-cavity aluminum profile die with significant differences in wall thickness for complex structures.

Pathways and biological mechanisms of N2O emission reduction by adding biochar in the constructed wetland based on 15N stable isotope tracing.

Constructed wetlands (CWs) added with biochar were built to study pollutant removal efficiencies, nitrous oxide (N2O) emission characteristics, and biological mechanisms in nitrogen transformation. The results showed that biochar addition enhanced the average removal rates of ammonium (NH4+-N), total nitrogen, and chemical oxygen demand by 4.03-18.5%, 2.90-4.99%, and 2.87-5.20% respectively while reducing N2O emissions by 25.85-83.41%. Based on 15N stable isotope tracing, it was found that nitrification, denitrification, and simultaneous nitrification and denitrification were the main processes contributing to N2O emission. The addition of biochar resulted in maximum reduction rates of 71.50%, 80.66%, and 73.09% for these three processes, respectively. The relative abundance of nitrogen-transforming microbes, such as Nitrospira, Dechloromonas, and Denitratisoma, increased after the addition of biochar, promoting nitrogen removal and reducing N2O emissions. Adding biochar could increase the functional gene copy number and enzyme activity responsible for nitrogen conversion, which helped achieve efficient NH4+-N oxidation and eliminate nitrite accumulation, thereby reducing N2O emissions.

Graphene-Promoted Adhesion-Reduced Expansion of Discontinuous Palladium Nanowires upon Hydrogenation.

Monitoring conductivity changes of discontinuous palladium (Pd) nanostructures upon hydrogenation is becoming one of the most promising approaches toward hydrogen sensing. Development of sensors in this type has long been impeded due to strong ubiquitous interfacial adhesion which could distinctly restrict Pd expansion so as to hinder the closing of a nanogap. Herein, graphene underlayers were applied in the fabrication of nanogap-based hydrogen sensors to promote the lateral expansion of a Pd nanowire upon hydrogenation by reducing the adhesion between the metal and the substrate. In order to clarify details as well as mechanisms underlaid of graphene-enhanced Pd expansion, nanowire samples with serial lengths (6-48 µm) and gaps (0-260 nm in width) were controllably prepared on single-layer graphene (SLG), double-layer graphene (DLG), and quadruple-layer graphene (QLG, DLG × 2) via the combination of electron beam lithography (EBL) and electron beam deposition (EBD) technology. Response features and intrinsic analysis in physical sense of the graphene-based discontinuous Pd circuits upon hydrogen were established, in light of which the effects of underlayers on Pd expansion and on nanogap closing process were investigated. Such graphene-promoted expansion was demonstrated through the achievement of the closure of a large gap threshold (Gt) up to 260 nm as well as the systematical investigation of its influence on the sensing performance.

Ultralow-Power Machine Vision with Self-Powered Sensor Reservoir.

A neuromorphic visual system integrating optoelectronic synapses to perform the in-sensor computing is triggering a revolution due to the reduction of latency and energy consumption. Here it is demonstrated that the dwell time of photon-generated carriers in the space-charge region can be effectively extended by embedding a potential well on the shoulder of Schottky energy barrier. It permits the nonlinear interaction of photocurrents stimulated by spatiotemporal optical signals, which is necessary for in-sensor reservoir computing (RC). The machine vision with the sensor reservoir constituted by designed self-powered Au/P(VDF-TrFE)/Cs2 AgBiBr6 /ITO devices is competent for both static and dynamic vision tasks. It shows an accuracy of 99.97% for face classification and 100% for dynamic vehicle flow recognition. The in-sensor RC system takes advantage of near-zero energy consumption in the reservoir, resulting in decades-time lower training costs than a conventional neural network. This work paves the way for ultralow-power machine vision using photonic devices.

Thermoinduced structural-transformation and luminescent conversion in hybrid manganese halides.

We report here the synthesis of hybrid manganese halide crystals, (C4H7N2)MnCl3· H2O and (C4H7N2)2MnCl4, by using the same organic ligand 2-methylimidazole. Upon heating treatment, the red-emissive (C4H7N2)MnCl3· H2O crystal is structurally transformed into green-emissive (C4H7N2)2MnCl4crystalin situ. The crystal structural analysis reveals that the [MnCl5· H2O]3-octahedra chains decompose into mono [MnCl4]2-tetrahedra, accompanied by the departure of H2O molecules. Upon cooling in air or water vapor, the crystal structure and luminescence of (C4H7N2)2MnCl4are transformed to those of (C4H7N2)MnCl3· H2O. Thein situconversion of luminescence between (C4H7N2)MnCl3· H2O and (C4H7N2)2MnCl4provides new insight into the potential application of hybrid manganese halides.

Synergistic effect of cobalt boride nanoparticles on MoS2 nanoflowers for a highly efficient hydrogen evolution reaction in alkaline media.

The development of efficient, stable and low-cost electrocatalysts for the alkaline hydrogen evolution reaction (HER) is critical for large-scale, economically viable water splitting. In this work, we successfully prepared non-precious metal CoB@MoS2 hybrid electrocatalysts for the HER in alkaline media by the reductive growth of cobalt boride nanoparticles (CoB NPs) on the surface of MoS2 nanoflowers (MoS2 NFs). The CoB@MoS2-0.5-300 hybrid showed an HER overpotential of only 146 mV at a current density of 10 mA cm-2 and a Tafel slope of 80.9 mV dec-1 in 1.0 M KOH solution. The significantly enhanced HER activity of the hybrid is primarily attributable to the ability of CoB to drive the OER in alkaline solution and improved electrical conductivity of the hybrid electrocatalyst relative to the pristine MoS2. Furthermore, the synthetic strategy used to prepare the CoB@MoS2 electrocatalyst was successfully applied to prepare NiB@MoS2 and FeB@MoS2 hybrid electrocatalysts, which similarly showed very good HER activity in 1.0 M KOH solution. Thus, this work conclusively demonstrates that the introduction of transition metal borides is an effective approach for enhancing the HER performance of MoS2 in alkaline media.

Modifying defect States in CeO2 by Fe doping: A strategy for low-temperature catalytic oxidation of toluene with sunlight.

Highly efficient, low cost and green ways to eliminate volatile organic compounds (VOCs), which are quite desirable due to the ever-increasing environmental issues. Photothermal catalytic oxidation provides a pathway for solving these problems, but its application is always limited by lack of low-cost and active catalysts. Herein, this limitation is overcome by using doping to refine defect states. As a proof of concept, hierarchical CeO2 nanorods are employed as a model material for subtle Fe doping. The results reveal that the oxygen defects facilitate activation of the OO bond and the migration and separation of the photogenerated charge carriers. By virtue of such favorable synergistic effect, a satisfactory toluene conversion (>98 %) was obtained. This work provides new insights into the design of highly effective catalysts and the construction of an economically viable process for VOC elimination.

Hybridization of CuO with Bi2MoO6 Nanosheets as a Surface Multifunctional Photocatalyst for Toluene Oxidation under Solar Irradiation.

Herein, CuO/Bi2MoO6 hybrid nanosheets were prepared as a surface multifunctional photocatalyst for gas-phase toluene oxidation with high conversion (>99%). Aberration-corrected scanning transmission electron microscopy suggested that CuO species were highly dispersed on the nanosheets. X-ray absorption fine structure spectra indicated that the distorted and stretched Cu-O coordination structures in CuO/Bi2MoO6 nanosheets would provide open active sites. In situ Fourier transform infrared and density functional theory results showed that toluene molecules could be chemisorbed and activated on the active sites of CuO/Bi2MoO6 nanosheets by the C-H group forming CuO/Bi2MoO6···Ph-CH3 surface complex compounds. These would induce electron-hole transfer and initiate photocatalytic reactions under visible light irradiation. The corresponding intermediates of benzaldehyde and benzoic acid would be detected by in situ diffuse reflectance infrared Fourier transform spectroscopy. Furthermore, the synergistic effect of CuO and Bi2MoO6 nanosheets could monitor charge dynamics to facilitate their respective transmission from photoexcitation sites to active centers. This work provides new insights into the essence of visible-light-driven surface photocatalysis and is expected to promote the design of novel and more effective photocatalysts at the molecular level.

The light-induced transcription factor FtMYB116 promotes accumulation of rutin in Fagopyrum tataricum.

Tartary buckwheat (Fagopyrum tataricum) not only provides a supplement to primary grain crops in China but also has high medicinal value, by virtue of its rich content of flavonoids possessing antioxidant, anti-inflammatory, and anticancer properties. Light is an important environmental factor that can regulate the synthesis of plant secondary metabolites. In this study, we treated tartary buckwheat seedlings with different wavelengths of light and found that red and blue light could increase the content of flavonoids and the expression of genes involved in flavonoid synthesis pathways. Through coexpression analysis, we identified a new MYB transcription factor (FtMYB116) that can be induced by red and blue light. Yeast one-hybrid assays and an electrophoretic mobility shift assay showed that FtMYB116 binds directly to the promoter region of flavonoid-3'-hydroxylase (F3'H), and a transient luciferase activity assay indicated that FtMYB116 can induce F3'H expression. After transforming FtMYB116 into the hairy roots of tartary buckwheat, we observed significant increases in the content of rutin and quercetin. Collectively, our results indicate that red and blue light promote an increase in flavonoid content in tartary buckwheat seedlings; we also identified a new MYB transcription factor, FtMYB116, that promotes the accumulation of rutin via direct activation of F3'H expression.

Comparative transcriptome analysis of roots, stems and leaves of Isodon amethystoides reveals candidate genes involved in Wangzaozins biosynthesis.

BACKGROUND: Isodon amethystoides (Ben-th) Cy Wu et Hsuan is an important traditional medicinal plant endowed with pharmacological properties effective in the treatment of various diseases, including pulmonary tuberculosis. The tetracyclic diterpenoids, Wangzaozins (Wangzaozin A, glaucocalyxin A, glaucocalyxin B), are the major bioactive compounds of I. amethystoides. However, the molecular information about the biosynthesis of these compounds still remains unclear. RESULTS: An examination of the accumulated levels of Wangzaozins in I. amethystoides revealed considerable variations in the root, stem, and leaf tissues of this plant, indicating possible differences in metabolite biosynthesis and accumulation among various tissues. To better elucidate the tetracyclic diterpenoid biosynthesis pathway, we generated transcriptome sequences from the root, stem, and leaf tissues, and performed de novo sequence assembly, yielding 230,974 transcripts and 114,488 unigenes, with average N50 lengths of 1914 and 1241 bp, respectively. Putative functions could be assigned to 73,693 transcripts (31.9%) based on BLAST searches against annotation databases, including GO, KEGG, Swiss-Prot, NR, and Pfam. Moreover, the candidate genes involving in the diterpenoid biosynthesis, such as CPS, KSL, were also analyzed. The expression profiles of eight transcripts, involving the tetracyclic diterpenoid biosynthesis, were validated in different I. amethystoides tissues by qRT-PCR, unraveling the gene expression profile of the pathway. The differential expressions of ISPD, ISPF and ISPH (MEP pathway), and IaCPS and IaKSL (diterpenoid pathway) candidate genes in leaves and roots, may contribute to the high accumulation of Wangzaozins in I. amethystoides leaves. CONCLUSION: The genomic dataset and analyses reported here lay the foundations for further research on this important medicinal plant.

Formation and dispersion of organometal halide perovskite nanocrystals in various solvents.

The solvent-induced precipitation in a mixture of good and poor solvents was often used to synthesize organometal halide perovskite nanocrystals (OMHP NCs). Here we investigate the formation of OMHP NCs by using HBr based precursors in various solvents. Various emission colors and morphologies of perovskite NCs were obtained depending on the solvents used. The nanoplatelets with blue emission were produced for the low polar solvents, such as toluene, PhCl and EtOAc. The increase in polarity of poor solvents results in the red shift of emission of obtained NCs. The much more polar solvents like acetone and CH3CN lead to formation of CH3NH3PbBr3 NCs (MaPbBr3) with cubic phase. The dispersion behaviors of MaPbBr3 NCs in different solvents was also investigated. MaPbBr3 NCs can exist stably in most unpolar solvents. However, they will be dissolved in polar solvents, like acetone and acetonitrile, to give rise to a clear solution with red emission of Pb2+. By injecting this clear solution to unpolar solvents, OMHP NCs can be reproduced.

[Investigation and optimization on ability of enzymatic hydrolysis of Mori Cortex residue].

Residue of Mori Cortex was studied to optimize its enzymatic hydrolysis process, and explore its potential as a carbon source for biochemistry and biofuel production. The cellulose content of diluted acid pretreated (DAP) and non-pretreated from Mori Cortex were measured in this study, and the results showed that the cellulose content of DAP and non-pretreated from Mori Cortex were 52.5% and 47%, respectively. This higher cellulose content indicated that residue of Mori Cortex had the potential to act as a carbon source for biochemistry and biofuel production. Enzymatic hydrolysis of pretreated and non-pretreated from Mori Cortex was conducted under different enzyme loading amount. 40 FPU·(g DW）⁻¹ enzyme loading was determined as the optimal amount by comparing the yield of sugar and the rate of enzymolysis. Under this condition, the concentrations of glucose, xylose, arabinose sugar were 23.82, 4.84, 3.6 g·L⁻¹, and the corresponding enzymatic hydrolysis rate was 45.33% which was 2.3 times higher than that of non-pretreated from Morus alba residues. Fed-batch enzymatic hydrolysis was conducted finally to get higher sugar yield, and the final glucose concentration reached up to 38 g·L⁻¹ with the enzymatic hydrolysis rate of 36.19%. The results indicated that Mori Cortex residue had higher cellulose and hemicellulose contents, so it had the potential to become a carbon source to produce the bio-chemicals and biofuels. Through enzymatic hydrolysis, it can be converted into microbial available monosaccharides; and through fermentation, it can be converted into high value-added chemicals, biofuels, etc., to solve the problem of residue pollution, and achieve the sustainable development and greening of Chinese pharmaceutical production process.

[Influence of light on gene expression of key synthesis enzyme genes FtANR and FtLAR about proanthocyanidin in seeds of homologous plant of food and medicine Fagopyrum tataricum].

Tartary buckwheat Fagopyrum tataricum is an important medicinal and functional herb due to its rich content of flavonoids in the seeds. F.tataricum exhibited good functions for free radicals scavenging， anti-oxidation， anti-aging activities. Although much genetic knowledge of the synthesis， regulation， accumulation of rutin， the genetic basis of proanthocyanidins(PAs) in tartary buckwheat and their related gene expression changes under different lights(blue， red， far red， ultraviolet light) remain largely unexplored. In this study， we cloned one anthocyanidin reductase gene(ANR) and two leucocyanidin reductase gene(LAR) named FtANR，FtLAR1，FtLAR3 involved in formation of(+)-catechin and(-)-epicatechin precusor proanthocyanidin by digging out F. tataricum seed transcriptome data. The expression data showed that the opposite influence of red light on these gene transcript level compared to others lights. The expression levels of FtANR and FtLAR1 decreased and FtLAR3 appeared increment after exposed in the red light， while the expression levels of those genes appeared opposite result after exposed in the blue and far red light.

[Identification of bear bile powder and its adulterants by using DNA barcoding technology].

To identify the precious bile powder and its adulterants by DNA barcoding, and establish its standard experimental process to ensure the safe and effective utilization. Total twelve sequences from samples of bear bile powder which come from Ursus thibetanus for DNA extraction, PCR(polymerase chain reaction) and sequence, then using CodonCode Aligner V 7.0.1 shear primer region to obtain COI sequence. The COI sequences of U. arctos and their adulterants were obtained from GenBank. MEGA7.0 software was applied for analyzing mutation, calculating intraspecific and interspecific K2P(Kimura 2-Parameter) genetic distance and constructing the Neighbor-joining tree(NJ). The results showed that the maximum K2P genetic distance of bear bile powder of U. thibetanus and U. arctos are far less than minimum K2P genetic distance within its adulterants species, and the results of NJ tree demonstrated that each species could be distinguished from the counterfeits obviously. DNA barcoding is a safe, convenient and reliable technique for species identification, and it is important to establish the standard sequence of COI sequences for animal medicines.

(Diisopropylammonium)2MnBr4: a multifunctional ferroelectric with efficient green-emission and excellent gas sensing properties.

Combination of excellent optical properties and ferroelectricity of hybrid materials leads to high-performance optoelectronic devices. Here we present a new organic-inorganic hybrid compound (diisopropylammonium)2MnBr4 (DIPA2MnBr4) which shows high temperature ferroelectricity accompanied by highly efficient green-light emission. DIPA2MnBr4 also exhibits sensitive and selective optical response to alcohol vapors.

One-pot aqueous synthesis of gadolinium doped CdTe quantum dots with dual imaging modalities.

A facile one-pot strategy has been developed for the aqueous synthesis of Gd doped CdTe (Gd:CdTe) QDs as fluorescence and magnetic resonance imaging dual-modal agent. The prepared Gd:CdTe QDs showed narrow size distribution and the average size was less than 5nm. The amount of Gd(3+) dopant in Gd:CdTe QDs significantly affected the optical properties of obtained QDs. The highest PL QY for the prepared Gd:CdTe QDs was up to 42.5%. The QDs showed the weak toxicity and significant enhancement in MRI signal. The specific relaxivity value (r1) was determined to be 4.22mM(-1)s(-1). These properties make the prepared Gd:CdTe QDs be an effective dual-modal imaging agent and have great potential applications in biomedical field.

[Association study of serum uric acid levels with clinical outcome and hemorrhagic transformation in stroke patients with rt-PA intravenous thrombolysis].

OBJECTIVE: To evaluate the relation of serum uric acid levels on admission with short-term clinical outcome and hemorrhagic transformation (HT) in patients with acute ischemic stroke treated with thrombolysis. METHODS: A total of 230 acute ischemic stroke patients treated with thrombolysis in our stroke unit from 2010 to 2013 were included. Demographics, disease severity, the uric acid levels on admission and hemorrhagic transformation were prospectively collected. At 90 days, the scores of the modified Rankin Scale>2 (mRS>2) was defined as poor prognosis and the scores of mRS≤2 was defined as excellent outcome. Stepwise Logistic regression models were used to analyze potential factors affecting the prognosis. RESULTS: The levels of serum uric acid in the patients with excellent outcome were significantly higher than in patients with poor outcome [(375±42) µmol/L vs (250±36) µmol/L, P=0.0026]. Logistic regression analysis revealed that high level of serum uric acid was related to excellent outcome (OR=1.25, 95% CI, 1.04-1.47, P=0.013). The serum uric acid level of non HT patients was significantly higher than the HT patients [(350±51) µmol/L vs (282±38) µmol/L, P=0.015]. After adjustment for the influence factors including age and hypertension, the level of uric acid was still negatively correlated with HT. CONCLUSION: Increased serum uric acid levels are associated with low incidence of HT and better prognosis in patients with stroke treated with reperfusion therapy.

Surgery for chronic total occlusion of the left main coronary artery.

BACKGROUND AND OBJECTIVES: Chronic total occlusion of the left main coronary artery (LMCA) is a rare condition, and the information on surgical experiences is limited. Although total occlusion of the LMCA is accompanied by well-developed collateral circulation, the condition of circulation is unstable during manipulation of the heart. We report our experience with revascularization in cases with total occlusion of the LMCA using the on-pump beating-heart (OnP-BH) technique. DESIGN AND SETTING: Retrospective case review of patients treated at The First Affiliated Hospital of China Medical University over a 10-year period (1999 to 2009). PATIENTS AND METHODS: The on-pump coronary artery bypass grafting with the beating heart was applied to 8 patients with chronic total occlusion of the LMCA. The extracorporeal circulation period, intubation duration, intensive care unit stay period, discharge period, preoperative and postoperative treatments, and follow-up were observed. RESULTS: The mean extracorporeal circulation period was 80.4 (19.7) minutes. The mean intubation duration was 13.0 (4.6) hours. The mean intensive care unit stay period was 3.2 (0.7) days, and the mean discharge period was 16.8 (3.3) days. No perioperative myocardial infarction occurred. The mean follow-up period was 50.9 (34.8) months. All patients were asymptomatic, and no deaths were recorded during the follow-up period. The results of echocardiography showed improvement in the left ventricular function. CONCLUSIONS: The OnP-BH myocardial revascularization seems to be a valid alternative for chronic total occlusion of the LMCA.

[Anatomical basis and short-term effect of in situ coronary venous arterialization].

OBJECTIVE: To study the anatomical basis of in situ coronary venous arterialization (ICVA) and to observe the short-term clinical outcome thereof. METHODS: Five recently isolated pig hearts underwent ligation of the posterior descending artery and the proximal end of middle cardiac vein (MCV), solution of Indian ink was perfused into this vein, and slices of heart were made to observe the distribution of ink through microscope. From January 2002 to December 2005, 64 consecutive patients with diffuse lesion and distal occlusion of right coronary artery received coronary artery bypass grafting (CABG) were randomly divided into 2 equal groups to undergo ICVA during CABG (ICVA group) and conventional CABG only (control group) respectively. The pre- and post-operation clinical data, including ECG, SPECT and ultrasonic cardiograph (UCG) were analyzed. RESULTS: Indian ink was distributed in the intercellular spaces and capillaries of the myocardium and appeared in the micro-arteries in all 5 pig hearts. The mean hospitalization time of the ICVA patients was 16.5 +/- 7.7 days. The mortality rate was 0. After the ICVA the ECG recovery rate in ST segment was 98.88%, and the improvement rate in the grade of the angina was 100%. SPECT and UCG both showed great improvement post-operatively (P < 0.05). CONCLUSION: After the ligation of the proximal end of MCV, the related myocardium can be perfused effectively by distal arterialization in situ. ICVA, fitting to patients with diffused lesion and distal occlusion of coronary artery, can be performed safely with satisfactory clinical outcomes.

A combination of omental flap and growth factor therapy induces arteriogenesis and increases myocardial perfusion in chronic myocardial ischemia: evolving concept of biologic coronary artery bypass grafting.

OBJECTIVE: The purpose of this study was to evaluate the therapeutic efficacy of the combined growth factor therapy with an omental flap in a rabbit model of chronic myocardial ischemia. METHODS: Chronic ischemia was created in rabbits by placing a constrictor on the left circumflex artery. Four weeks later the animals were divided into 3 groups: group FG, in which a gelatin hydrogel sheet incorporating 100 microg of basic fibroblast growth factor was placed over the left circumflex region followed by covering with the omental flap including the intact gastroepiploic artery; group F, in which only the basic fibroblast growth factor sheet was placed; and group N, in which no treatment was done. RESULTS: Cine magnetic resonance imaging analysis showed a greater percentage wall thickening in the left circumflex region in group FG than in other groups (group FG, 49.2% +/- 4.5%; group F, 41.2% +/- 3.8%; group N, 32.1% +/- 2.5%, P =.035, group FG vs group F). A colored microsphere assay showed higher perfusion in the left circumflex region in group FG than in group F. Perfusion in the left circumflex region was decreased after clamping the gastroepiploic artery pedicle in group FG (before clamping, 2.83 +/- 0.72 mL x min(-1) x g(-1); after clamping, 1.93 +/- 0.59 mL x min(-1) x g(-1); P < .01). In vivo angiography via gastroepiploic artery showed direct "to-and-fro" visible collaterals between the gastroepiploic and occluded left circumflex coronary arteries in group FG. CONCLUSION: The combined growth factor therapy with an omental flap induced arteriogenesis and provided additional perfusion via the gastroepiploic artery to ameliorate regional dysfunction in the chronically ischemic myocardium.