Enhanced energy-absorbing and sound-absorbing capability of functionally graded and helicoidal lattice structures with triply periodic minimal surfaces

Lattice structures have drawn much attention in engineering applications due to their lightweight and multi-functional properties.In this work,a mathematical design approach for functionally graded(FG)and helicoidal lattice structures with triply periodic minimal surfaces is proposed.Four types of lattice structures including uniform,helicoidal,FG,and combined FG and helicoidal are fabricated by the additive manufacturing technology.The deformation behaviors,mechanical properties,energy absorption,and acoustic properties of lattice samples are thoroughly investigated.The load-bearing capability of helicoidal lattice samples is gradually improved in the plateau stage,leading to the plateau stress and total energy absorption improved by over 26.9%and 21.2%compared to the uniform sample,respectively.This phenomenon was attributed to the helicoidal design reduces the gap in unit cells and enhances fracture resistance.For acoustic properties,the design of helicoidal reduces the resonance frequency and improves the peak of absorption coefficient,while the FG design mainly influences the peak of absorption coefficient.Across broad range of frequency from 1000 to 6300 Hz,the maximum value of absorption coefficient is improved by18.6%-30%,and the number of points higher than 0.6 increased by 55.2%-61.7%by combining the FG and helicoidal designs.This study provides a novel strategy to simultaneously improve energy absorption and sound absorption properties by controlling the internal architecture of lattice structures.

Ethylene Copolymerization with Linear and End-Cyclized Olefins via a Metallocene Catalyst:Polymerization Behavior and Thermal Properties of Copolymers

Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.

Smart Design and Manufacturing the Welded Q350 Steel Frames via Lifecycle Management Strategy of Digital Twin

Artificial intelligent aided design and manufacturing have been recognized as one kind of robust data-driven and data-intensive technologies in the integrated computational material engi-neering(ICME)era.Motivated by the dramatical developments of the services of China Railway High-speed series for more than a decade,it is essential to reveal the foundations of lifecycle man-agement of those trains under environmental conditions.Here,the smart design and manufacturing of welded Q350 steel frames of CR200J series are introduced,presenting the capability and opportu-nity of ICME in weight reduction and lifecycle management at a cost-effective approach.In order to address the required fatigue life time enduring more than 9×10^(6)km,the response of optimized frames to the static and the dynamic loads are comprehensively investigated.It is highlighted that the maximum residual stress of the optimized welded frame is reduced to 69 MPa from 477 MPa of previous existing one.Based on the measured stress and acceleration from the railways,the fatigue life of modified frame under various loading modes could fulfil the requirements of the lifecycle man-agement.Moreover,our recent developed intelligent quality control strategy of welding process mediated by machine learning is also introduced,envisioning its application in the intelligent weld-ing.

An overview of autophagy in the differentiation of dental stem cells

Dental stem cells(DSCs)have attracted significant interest as autologous stem cells since they are easily accessible and give a minimal immune response.These properties and their ability to both maintain self-renewal and undergo multi-lineage differentiation establish them as key players in regenerative medicine.While many regulatory factors determine the differentiation trajectory of DSCs,prior research has predominantly been based on genetic,epigenetic,and molecular aspects.Recent evidence suggests that DSC differentiation can also be influenced by autophagy,a highly conserved cellular process responsible for maintaining cellular and tissue homeostasis under various stress conditions.This comprehensive review endeavors to elucidate the intricate regulatory mechanism and relationship between autophagy and DSC differentiation.To achieve this goal,we dissect the intricacies of autophagy and its mechanisms.Subsequently,we elucidate its pivotal roles in impacting DSC differentiation,including osteo/odontogenic,neurogenic,and angiogenic trajectories.Furthermore,we reveal the regulatory factors that govern autophagy in DSC lineage commitment,including scaffold materials,pharmaceutical cues,and the extrinsic milieu.The implications of this review are far-reaching,underpinning the potential to wield autophagy as a regulatory tool to expedite DSC-directed differentiation and thereby promote the application of DSCs within the realm of regenerative medicine.

Navigation-assisted transcortical transventricular approach for paraventricular cavernoma:A technical note and review of the literature

The surgery of paraventricular cavernoma remains a challenge for the neurosurgeon.Few approaches have been specially described for paraventricular cavernoma in literature.We present a patient with a symptomatic paraventricular cavernoma in the dorsal portion of the right lateral ventricles roof causing ventricular hemorrhage,and review his surgical approaches.This patient underwent a navigationassisted transcortical transventricular approach resulting in a complete resection without any neurologic deficits.The approach allows a safe and effective resection of paraventricular cavernomas.

Development and application of photocatalytic coating for roadside NO_(x) mitigation in Hong Kong

A facile chemical method for the development of photocatalytic coating products was proposed based on practical application perspective for the Hong Kong roadside nitrogen oxides(NO_(x))mitigation.TiO_(2)-based photocatalytic coating PC-C film with crystallized size of around 5–6 nm was synthesized with the peptization of H_(2)O_(2).The PC-C coating possesses a super-hydrophilicity surface and is proven to have a NO_(x)degradation rate of 46.8%with an optimum pH level of 7.In addition,the PC-C coating presents a promising photocatalytic NO_(x)degradation compared with other commercially available coating products and P25 when applied on two building materials of poly-methyl methacrylate(PMMA)and concrete surface.A weather resistance simulation and a 180-day on-site field trial were carried out the attenuation effects of photocatalytic coating applied in outdoor exposure.Based on epidemiological estimation and field investigation,hospital admissions for respiratory diseases(HARD)and mortality cases(MC)could be reduced with the application of PC-C coating along the street canyon.This work demonstrates the feasibility of air pollution control measures for the local roadside NO_(x)using photocatalytic technology,offering promising health benefits with environmental remediation.

Overview of finite elements simulation of temperature profile to estimate properties of materials 3D-printed by laser powder-bed fusion

Laser powder bed fusion(LPBF),like many other additive manufacturing techniques,offers flexibility in design expected to become a disruption to the manufacturing industry.The current cost of LPBF process does not favor a try-anderror way of research,which makes modelling and simulation a field of superior importance in that area of engineering.In this work,various methods used to overcome challenges in modeling at different levels of approximation of LPBF process are reviewed.Recent efforts made towards a reliable and computationally effective model to simulate LPBF process using finite element(FE)codes are presented.A combination of ray-tracing technique,the solution of the radiation transfer equation and absorption measurements has been used to establish an analytical equation,which gives a more accurate approximation of laser energy deposition in powder-substrate configuration.When this new analytical energy deposition model is used in in FE simulation,with other physics carefully set,it enables us to get reliable cooling curves and melt track morphology that agree well with experimental observations.The use of more computationally effective approximation,without explicit topological changes,allows to simulate wider geometries and longer scanning time leading to many applications in real engineering world.Different applications are herein presented including:prediction of printing quality through the simulated overlapping of consecutive melt tracks,simulation of LPBF of a mixture of materials and estimation of martensite inclusion in printed steel.

The E3 ubiquitin ligase NEDD4-1 protects against acetaminophen-induced liver injury by targeting VDAC1 for degradation

Acetaminophen(APAP)overdose is a major cause of liver injury.Neural precursor cell expressed developmentally downregulated 4—1(NEDD4-1)is an E3 ubiquitin ligase that has been implicated in the pathogenesis of numerous liver diseases;however,its role in APAP-induced liver injury(AILI)is unclear.Thus,this study aimed to investigate the role of NEDD4-1 in the pathogenesis of AILI.We found that NEDD4-1 was dramatically downregulated in response to APAP treatment in mouse livers and isolated mouse hepatocytes.Hepatocyte-specific NEDD4-1 knockout exacerbated APAP-induced mitochondrial damage and the resultant hepatocyte necrosis and liver injury,while hepatocyte-specific NEDD4-1 overexpression mitigated these pathological events both in vivo and in vitro.Additionally,hepatocyte NEDD4-1 deficiency led to marked accumulation of voltage-dependent anion channel 1(VDAC1)and increased VDAC1 oligomerization.Furthermore,VDAC1 knockdown alleviated AILI and weakened the exacerbation of AILI caused by hepatocyte NEDD4-1 deficiency.Mechanistically,NEDD4-1 was found to interact with the PPTY motif of VDAC1 through its WW domain and regulate K48-linked ubiquitination and degradation of VDAC1.Our present study indicates that NEDD4-1 is a suppressor of AILI and functions by regulating the degradation of VDAC1.

The Relationship Between Physical Activity and All-Cause Mortality Among Older Adults--China, 1998–2018

Summary What is already known about this topic?Previous research indicates that non-occupational physical activity can reduce mortality risk.Nevertheless,the relationship between occupational physical activity and health improvements has not been consistently established.What is added by this report?The study found that regular exercise and leisure activities reduced the risk of all-cause mortality.However,the combination of exercise and leisure activities demonstrated more substantial benefits.Additionally,no meaningful association was identified between physical work and mortality risk within the older population.

Surgical strategies for peripheral nerve schwannoma based on the intraoperative neurophysiological monitoring

Objective:To present our classification for peripheral nerve schwannomas as well as explore the surgical strategies and operative management of peripheral nerve schwannomas based on the intraoperative neurophysiological monitoring(INM)technique and to decrease the risk of postoperative neurological deficits in the management of these schwannomas.Materials and methods:A retrospective study was conducted on 92 cases of peripheral nerve microsurgery performed,using the INM technique.We also made the classification for peripheral nerve schwannomas into two types according to operative findings and proceeded corresponding surgical strategies.Results:All tumors were removed completely under microscopy and INM.Three patients developed residual neurological deficits at final follow-up.There were different results about temporary(18/92,19.6%)and permanent(3/92,3.3%)neurological deficits.The incidence of temporary and permanent neurological deficits in type II group was significantly higher than that in type I group(p<0.01).The incidence of permanent neurological deficits in larger size tumors was significantly higher than that of smaller size(p<0.01).Conclusions:We made the classification for peripheral nerve schwannomas according to operative findings based on INM that is helpful to our surgical strategies.Intracapsular enucleation was the preferred strategy with satisfactory results and low risk of nerve injury.The size and location of tumors seem to be related to the risk of fascicular injury.

Occurrence and fate of antibiotics in advanced wastewater treatment facilities and receiving rivers in Beijing, ChinaOccurrence and fate of antibiotics in advanced wastewater treatment facilities and receiving rivers in Beijing, China

The occurrence and removal of 13 antibiotics were investigated in five wastewater treatment plants （WWTPs） with advanced wastewater treatment processes in Beijing, China. Most of the target antibiotics were detected in the secondary and tertiary effluents, with the concentrations of 4.8-1106.0 and 0.3-505.0ng·L^-1. Fluoroquinolone antibiotics showed relatively high concentrations in all samples （782-1814ng·L^-1）. Different tertiary treatment processes showed discrepant antibiotics removal performances. Ozonation process was found more effective in removing target antibiotics compared to the coagulation-flocculation-sedimentation process and sand filtration process. Investigation of the target antibiotics in three typical urban rivers in Beijing was carried out to understand antibiotics occurrence in surface water environment. Eight antibiotics were detected in the studied rivers, with highest concentration of antibiotics in the fiver which was mainly replenished by reclaimed water. This study showed the necessity of employing more effective advanced treatment facilities to further reduce the discharge amount of antibiotics.

Porous FeO_x/BiVO_(4-δ)S_(0.08): Highly efcient photocatalysts for the degradation of Methylene Blue under visible-light illumination

Porous S-doped bismuth vanadate with an olive-like morphology and its supported iron oxide （y wt.% FeOx/BiVO4-δS0.08, y = 0.06, 0.76, and 1.40） photocatalysts were fabricated using the dodecylamine-assisted alcohol-hydrothermal and incipient wetness impregnation methods, respectively. It is shown that the y wt.% FeOx/BiVO4-δS0.08 photocatalysts contained a monoclinic scheetlite BiVO4 phase with a porous olive-like morphology, a surface area of 8.8-9.2 m^2/g, and a bandgap energy of 2.38-2.42 eV. There was co-presence of surface Bi^5＋, Bi^3＋, V^5＋, V^3＋, Fe^3＋, and Fe^2＋ species in y wt.% FeOx/BiVO4-δS0.08. The 1.40 wt.% FeOx/BiVO4-δS0.08 sample performed the best for Methylene Blue degradation under visible-light illumination. The photocatalytic mechanism was also discussed. We believe that the sulfur and FeOx co-doping, higher oxygen adspecies concentration, and lower baudgap energy were responsible for the excellent visible-light-driven catalytic activity of 1.40 wt.% FeOx/BiVO4-δS0.08.

Nuciferine protects against high-fat diet-induced hepatic steatosis and insulin resistance via activating TFEB-mediated autophagy——lysosomal pathway

Nonalcoholic fatty liver disease(NAFLD) is characterized by hepatic steatosis and insulin resistance and there are currently no approved drugs for its treatment.Hyperactivation of mTOR complex1(mTORCl) and subsequent impairment of the transcription factor EB(TFEB)-mediated autophagy-lysosomal pathway(ALP) are implicated in the development of NAFLD.Accordingly,agents that augment hepatic TFEB transcriptional activity may have therapeutic potential against NAFLD.The objective of this study was to investigate the effects of nuciferine,a major active component from lotus leaf,on NAFLD and its underlying mechanism of action.Here we show that nuciferine activated ALP and alleviated steatosis,insulin resistance in the livers of NAFLD mice and palmitic acid-challenged hepatocytes in a TFEB-dependent manner.Mechanistic investigation revealed that nuciferine interacts with the Ragulator subunit hepatitis B X-interacting protein and impairs the interaction of the Ragulator complex with Rag GTPases,thereby suppressing lysosomal localization and activity of mTORC1,which activates TFEB-mediated ALP and further ameliorates hepatic steatosis and insulin resistance.Our present results indicate that nuciferine may be a potential agent for treating NAFLD and that regulation of the mTORCl-TFEB-ALP axis could represent a novel pharmacological strategy to combat NAFLD.

Additively manufactured heterogeneously porous metallic bone with biostructural functions and bone-like mechanical properties

A compatible artificialbone impla nt requires large pores for enhanced nutrients transports,small pores to allow cell seeding and bone-like mechanical properties to avoid stress shielding.Herein,we report novel improved gyroid lattices with millimetre-scaled gyroid wall spacings and micrometre-scaled additional pores on the walls.Designs are successfully fabricated by electron beam melting using Ti-6 Al-4 V to high part qualities while exhibiting bone-like mechanical properties with a range of Young's modulus of 8-15 GPa and strength of 150-250 MPa.The improved design also eliminates brittle failure by allowing the structure to deform more stably.

Advances in the study of the systematics of Actinidia Lindley

Actinidia(Actinidiaceae)is of economic importance for its edible fruits.Traditional taxonomy divided the genus into four sections,Leiocarpae Dunn,Maculatae Dunn,Strigosae Li,and Stellatae Li.However,phylogenetic studies based on morphology and molecular markers have posed challenges to the four-section scheme.It appears that the natural classification of the genus points to the existence of two groups,one comprising Leiocarpae,and the other Maculatae,Strigosae,and Stellatae.Single-or low-copy genes would probably be useful in untangling the perplexity and the reticulate evolution of the genus.However,any phylogenetic studies must be firmly based on sound taxonomy and identification.Population sampling throughout the distribution range of the taxa should be carried out in order to study the variation pattern of the morphology and,ultimately,to clarify the confusion existing in some taxa.A combination of morphometrics and molecular data is highly desirable for resolving the uncertainty in Actinidia taxonomy.

Customisable sound absorption properties of functionally graded metallic foams

In this study,functionally graded foam made of Inconel 625 superalloy was successfully produced using the template replication method,with open-cell polyurethane foams as a precursor.The products have a similar pore morphology as the templates and adjacent layers were successfully sintered together by particle bonding.Sound absorption experiments on graded metallic foams reveal that the sound absorption at particular frequency ranges can be improved by various permutations of foam layers.For graded foam of two distinct pore sizes,a mathematical equation was proposed to predict the location of the intersection point of the sound absorption curves,thereby aiding in graded foam design.An increase in sound absorption coefficients by resonance-like effects can be introduced before the intersection points by placing the foam layer of smaller pore size nearer to the sound source.The sound absorption performances can be further customized when the thickness proportion of the pore sizes is changed and when the number of distinct pore sizes used is increased.The sound absorption performance at lower frequencies is generally boosted by resonance-like effects when the layer of foam with the largest pore size is placed furthest from the sound source.Given the same composition of foam with a fixed thickness proportion of pore sizes,one can introduce resonance-like effects to improve the sound absorption performance compared to other permutations while possibly satisfying weight requirements in practical applications.This study provides valuable insights and mathematical guidelines in the design and manufacturing of functionally graded metallic foam for specific applications.

Stereoselective Photochemical Reaction of Cyclohexyl Phenyl Ketone within Lytropic Liquid Crystals Formed by Chiral Ionic Liquids

Irradiation of cyclohexyl phenyl ketone （1） results in either intra- or intermolecular hydrogen abstraction to af- ford compounds 1-phenylhept-6-en-l-one （2） and a-cyclohexyl benzyl alcohol （3） as photoproducts, in which 3 has a pair of enantiomers. Herein, two types of chiral hexagonal liquid crystals were prepared to direct the enantioselec- tive photochemical reaction of 1. One of the hexagonal liquid crystals is composed of 1-tetradecyl-3-methyl- imidazolium bromide/p-xylene/H2O with the modification by a chiral inductor. The other one is formed by chiral （S）-3-hexadecyl-1-（1-hydroxy-propan-2-yl）-imidazolium bromide/p-xylene/H2O. The product analysis shows that the latter one can be used as a microreactor to achieve stereoselective photochemical reaction, while the former one produced compound 3 with no enantioselectivity at all.

Population Attributable Fractions for Modifiable Factors of Longevity and Healthy Longevity Among the Late-Elderly Aged 75 Years or Older—China,1998-2018

Summary What is already known about this topic?Limited evidence on healthy longevity was provided in the world,and no studies investigated the fractions of healthy longevity attributed to modifiable factors.What is added by this report?Incidences of longevity and healthy longevity in China are provided.It reveals that the total weighted population attributable fractions for lifestyles and all modifiable factors were 32.8% and 83.7% for longevity,respectively,and 30.4% and 73.4% for healthy longevity,respectively.What are the implications for public health practice?China has a high potential for longevity and healthy longevity.Strategies may be targeted at education and residence in early life as well as healthy lifestyles,disease prevention,and functional optimization in late life.

MgAl-LDH强化Bi单质等离子体光催化性能的机制

通过液相超声辅助组装的方式将铋纳米球(Bi-NPs)均匀负载于层状氢氧化镁铝(MgAl-LDH)纳米片上,成功合成Bi@MgAl-LDH复合光催化剂.该催化剂在光照射下,可通过Bi单质等离子体效应连续高效氧化空气中ppb(十亿体积气体中所含污染物体积)浓度量级的NO(去除效率可稳定在56%).采用X射线衍射仪(XRD)、电子扫描显微镜(SEM)和紫外可见漫反射光谱(UV-visDRS)等手段对催化剂物相、形貌、化学组成和光学性质进行了表征分析,结合电子顺磁共振(ESR)氧化自由基捕获实验并采用原位红外光谱技术对光催化氧化NO过程进行动态监测发现,虽然MgAl-LDH作为载体没有与Bi球形成异质结结构,但其表面富含丰富的氢氧根离子,能与Bi球上光激发产生的空穴快速结合,形成·OH自由基;而光生空穴的快速消耗又能降低其与光生电子的复合,增强光电分离,促进超氧自由基形成,通过这两方面的协同作用增强了Bi球对NO的光催化氧化效果.更重要的是,LDH具有独特的水分子记忆效应,在光催化过程中被消耗的氢氧根离子可通过吸附空气中水分而不断补充,促使催化活性的稳定高效.本文的研究结果为Bi单质基等离子体直接光催化降解气相污染物性能强化提供了新的策略,同时对光催化反应机制的研究提出了新的思路.

Combined process of biofiltration and ozone oxidation as an advanced treatment process for wastewater reuse

The effluent of a wastewater treatment plant was treated in a pilot plant for reclaimed water production through the denitrification biofilter （DNBF） process, ozonation （O3）, and biologic aerated filtration （BAF）. The combined process demonstrated good removal performance of conventional pollutants, including con- centrations of chemical oxygen demand （27.8 mg·L^-1） and total nitrogen （9.9 mg·L^-1） in the final effluent, which met the local discharge standards and water reuse purposes. Micropollutants （e.g., antibiotics and endocrine-disrupting chemicals） were also significantly removed during the proposed process. Ozonation exhibited high antibiotic removal efficiencies, especially for tetracycline （94%）. However, micropollutant removal efficiency was nega- tively affected by the nitrite produced by DNBF. Acute toxicity variations of the combined process were estimated by utilizing luminescent bacteria. Inhibition rate increased from 9% to 15% during ozonation. Carbonyl compound concentrations （e.g., aldehydes and ketones） also increased by 58% as by-products, which consequently increased toxicity. However, toxicity eventually became as low as that of the influent because the by-products were effectively removed by BAR The combined DNBF/O3/ BAF process is suitable for the advanced treatment of reclaimed water because it can thoroughly remove pollutants and toxicity.