The Influence of Different Contents of Bi Addition on the Corrosion Behavior of Various Zirconium-Based Alloys

Zr-4(Zr-1.5Sn-0.2Fe-0.1Cr,wt%), S5(Zr-0.8Sn-0.34Nb-0.39Fe-0.1Cr), T5(Zr-0.7Sn-1.07Nb-0.32Fe-0.08Cr) and Zr-1Nb were adopted to prepare Bi-containing zirconium alloys for systematically investigating the effect of Bi addition on the corrosion resistance of zirconium alloys. The specimens were corroded in superheated steam at 400℃/10.3 MPa, and in lithiated water with 0.01 M LiOH or in deionized water at 360℃/18.6 MPa by autoclave testing. Results show that the corrosion resistance increases with the increasing of Bi content dissolved in α-Zr. But the presence of Bi-con- taining second phase particles (SPPs) is unfavorable for the enhancement of corrosion resistance. This indicates that the Bi dissolved in α-Zr matrix plays an important role in improving the corrosion resistance, while the precipitation of the Bi-containing SPPs does harm to the corrosion resistance.

Eu^(3+)掺杂的聚偏氟乙烯/聚氨酯多功能复合纤维的制备与性能

通过静电纺丝方法制备一种掺杂Eu^(3+)的红色荧光、压电兼具弹性的聚偏氟乙烯(PVDF)/聚氨酯(PU)多功能复合纳米纤维,研究了不同混合溶剂体系(二甲基甲酰胺/丙酮混合溶剂和二甲基甲酰胺/四氢呋喃混合溶剂体系)、不同铕配合物的掺杂对复合纳米纤维结晶结构、形貌、荧光性能、压电性能及拉伸性能的影响。研究结果表明,在PVDF中加入PU可制备弹性压电材料,同时掺杂稀土Eu^(3+)既可以起到成核剂作用诱导PVDF/PU复合纤维电活性β相的产生,还能赋予弹性压电材料的荧光性能,故Eu-PVDF/PU膜具备荧光、压电兼具弹性等性能,除在能量收集、可穿戴电子设备及传感器领域应用外,因Eu-PVDF/PU主体中的非对称Eu^(3+)场有利于调节红色,还可用于光电传感器、发光二极管、激光器等领域。

Geological evolution of offshore pollution and its long-term potential impacts on marine ecosystems

Populations and metropolitan centers are accumulated in coastal areas around the world.In view of the fact that they are geographically adjacent to coasts and intense anthropogenic activities,increasing global offshore pollution has been an important worldwide concern over the past several decades and has become a very serious problem that needs to be addressed urgently.Due to offshore pollution,various geological disasters occur in high frequency,including intensified erosion and salinization of coastal soils,frequent geological collapses and landslides and increasing seismic activities.Moreover,offshore pollution shows increasingly serious impacts on the topography and geomorphology of offshore and coastal areas,including coastal degradation,retreating coastlines and estuary delta erosion.Offshore sedimentation processes are strongly influenced by the pH changes of terrestrial discharges,and sedimentary dynamics have become extremely acute and complex due to offshore pollution.The seabed topography and hydrodynamic environment determine the fate and transport of pollutants entering offshore regions.Coastal estuaries,port basins and lagoons that have relatively moderate ocean currents and winds are more likely to accumulate pollutants.Offshore regions and undersea canyons can be used as conduits for transporting pollutants from the continent to the seabed.It is particularly noteworthy that the spatial/temporal distribution of species,community structures,and ecological functions in offshore areas have undergone unprecedented changes in recent decades.Due to increasing offshore pollution,the stable succession and development trend of marine ecosystems has been broken.It is thus important to identify and regulate the quantity,composition and transportation of pollutants in offshore regions and their behavior in marine ecosystems.In particular,crucial actions for stabilizing marine ecosystems,including increasing species and biodiversity,should be implemented to enhance their anti-interference capabilities.This review provides an overview of the current situation of offshore pollution,as well as major trends of pollutant fate and transportation from continent to marine ecosystems,transformation of pollutants in sediments,and their bioaccumulation and diffusion.This study retrospectively reviews the long-term geological evolution of offshore pollution from the perspective of marine geology,and analyses their long-term potential impacts on marine ecosystems.Due to ecological risks associated with pollutants released from offshore sediments,more research on the influence of global offshore pollution based on marine geology is undoubtedly needed.

Review of Propodea Malaise(Hymenoptera: Tenthredinidae) with descriptions of two new species, three new records from China and a new record from Nepal

Propodea Malaise, 1945 is reviewed and redescribed. Seven species of Propodea are discussed.Propodea sinica Wu Wei sp. nov. and P. xanthocera Wu Wei sp. nov. are described as new to science.Propodea rotundiventris（Cameron, 1899）, P. fentoni（Kirby, 1882） and Propodea ussuriensis（Malaise, 1931）are recorded for the first time from China. A key to species of Propodea Malaise is also provided. Tenthredo rufonotalis Mallach, 1936 is removed from being a junior synonym of Dipteromorpha ussuriensis Malaise,1931. Propodea rufonotalis（Mallach, 1936） is a new combination transferred from Tenthredo. The species previously recorded as Propodea rotundiventris（Cameron, 1899） from China before this paper is a misidentification of P. sinica sp. nov. The real Propodea rotundiventris（Cameron, 1899） is redescribed based on the holotype and new material. Propodea spinosa（Cameron, 1899） is recorded for the first time from Nepal.

Two new Tenthredo species(Hymenoptera: Tenthredinidae) from China

Tenthredo bicuspis Liu Wei sp. nov. and T. biminutidota Liu Wei sp. nov. are described from China. Tenthredo bicuspis is similar to T. amurica Dalla Torre, 1894 from Siberia in Russia but differs in the pterostigma yellow brown, the upper inner orbits, temple, pronotum, tegula, mesoscutellum and mesepisternum with distinct white maculae, the mesoscutellum strongly elevated with two obtuse peaks, the dorsum of head impunctate, the dorsum of thorax and mesopleuron shiny, the supraantennal tubercles strongly elevated with the posterior end abruptly cut off. Tenthredo biminutidota is similar to T. flavobrunneus Malaise,1945 but differs in the postocellar area about 1.5 times as broad as long, the lateral furrows distinctly divergent backwards; the black macula on dorsum of head very large and almost touching the eye or nearly so, the supraantennal tubercles largely black and evenly merging with frontal walls; the mesoscutellum and mesepisternum not strongly elevated with a low peak; each abdominal tergite with a narrow basal black band and a pair of black dots laterally; the female hypopygium with a large middle process and serrulae hardly elevated.

Interfacial mechanism of hydrogel with controllable thickness for stable drag reduction

Surface wettability plays a significant role in reducing solid–liquid frictional resistance,especially the superhydrophilic/hydrophilic interface because of its excellent thermodynamic stability.In this work,poly(acrylic acid)-poly(acrylamide)(PAA–PAM)hydrogel coatings with different thicknesses were prepared in situ by polydopamine(PDA)-UV assisted surface catalytically initiated radical polymerization.Fluid drag reduction performance of hydrogel surface was measured using a rotational rheometer by the plate–plate mode.The experimental results showed that the average drag reduction of hydrogel surface could reach up to about 56%in Couette flow,which was mainly due to the interfacial polymerization phenomenon that enhanced the ability of hydration layer to delay the momentum dissipation between fluid layers and the diffusion behavior of surface.The proposed drag reduction mechanism of hydrogel surface was expected to shed new light on hydrogel–liquid interface interaction and provide a new way for the development of steady-state drag reduction methods.

Developmental Impairments of Synaptic Refinement in the Thalamus of a Mouse Model of Fragile X Syndrome

While somatosensory over-reactivity is a common feature of autism spectrum disorders such as fragile X syndrome(FXS),the thalamic mechanisms underlying this remain unclear.Here,we found that the developmental elimination of synapses formed between the principal nucleus of V(PrV)and the ventral posterior medial nucleus(VPm)of the somatosensory system was delayed in fragile X mental retardation 1 gene knockout(Fmr1 KO)mice,while the developmental strengthening of these synapses was disrupted.Immunohistochemistry showed excessive VGluT2 puncta in mutants at P12–13,but not at P7–8 or P15–16,confirming a delay in somatic pruning of PrV-VPm synapses.Impaired synaptic function was associated with a reduction in the frequency of quantal AMPA events,as well as developmental deficits in presynaptic vesicle size and density.Our results uncovered the developmental impairment of thalamic relay synapses in Fmr1 KO mice and suggest that a thalamic contribution to the somatosensory over-reactivity in FXS should be considered.

Identification of 3-ketocapnine reductase activity within the human microbiota

The microbial synthesis of sulfonolipids within the human body is likely involved in maintaining human health or causing diseases.However,the enzymes responsible for their biosynthesis remain largely unknown.In this study,we identified and verified the role of 3-ketocapnine reductase,the third-step enzyme,in the four-step conversion of L-phosphoserine into sulfobacin B both in vivo and in vitro.This finding builds upon our previous research into sulfonolipid biosynthesis,which focused on the vaginal bacterium Chryseobacterium gleum DSM 16776 and the gut bacterium Alistipes finegoldii DSM 17242.Through comprehensive gene mapping,we demonstrate the widespread presence of potential sulfonolipid biosynthetic genes across diverse bacterial species inhabiting various regions of the human body.These findings shed light on the prevalence of sulfonolipid-like metabolites within the human microbiota,suggesting a potential role for these lipid molecules in influencing the intricate biointeractions within the complex microbial ecosystem of the human body.

Express,on of the novel adipokine ClqTNF-related protein 4 （CTRP4） suppresses colitis and colitis- associated colorectal cancer in mice

Inflammatory bowel disease （IBD） is an important factor in the induction of colon cancer, but its mechanism is unclear. Colitis and colitis-associated colorectal cancer （CAC） models induced using both dextran sulfate sodium （DSS） and the azoxymethane/DSS protocol were established in wild-type （WT） and CTRP4 transgenic （CTRP4-tg） C57BL6/J mice. Body weight, stool consistency and the presence of blood in the stool were analyzed; tumor quantity, size and histological characteristics were analyzed during the development of CAC. The CTRP4-tg mice exhibited significantly reduced colitis and developed far fewer macroscopic tumors; these tumors were smaller in size, and a majority of the colon tumors in these mice were restricted to the superficial mucosa. Tumors of lower grades were observed in the CTRP4-tg mice. Interleukin-6 was markedly downregulated in the CTRP4-tg mice during CAC tumorigenesis. The phosphorylation of ERK, signal transducer and activator of transcription 3 and Akt in the colon and the proliferation of intestinal epithelial cells were decreased in the CTRP4-tg mice. The injection of recombinant CTRP4 protein significantly reduced the colitis symptoms of the WT mice. CTRP4 plays an important role in inflammation and inflammation-associated colon tumorigenesis, and our research may provide a novel method for the treatment of IBD and CAC.

Brain-wide Mapping of Mono-synaptic Afferents to Different Cell Types in the Laterodorsal Tegmentum

The laterodorsal tegmentum(LDT) is a brain structure involved in distinct behaviors including arousal,reward, and innate fear. How environmental stimuli and top-down control from high-order sensory and limbic cortical areas converge and coordinate in this region to modulate diverse behavioral outputs remains unclear.Using a modified rabies virus, we applied monosynaptic retrograde tracing to the whole brain to examine the LDT cell type specific upstream nuclei. The LDT received very strong midbrain and hindbrain afferents and moderate cortical and hypothalamic innervation but weak connections to the thalamus. The main projection neurons from cortical areas were restricted to the limbic lobe, including the ventral orbital cortex(VO), prelimbic, and cingulate cortices. Although different cell populations received qualitatively similar inputs, primarily via afferents from the periaqueductal gray area, superior colliculus, and the LDT itself, parvalbumin-positive(PV?) GABAergic cells received preferential projections from local LDT neurons.With regard to the different subtypes of GABAergic cells, aconsiderable number of nuclei, including those of the ventral tegmental area, central amygdaloid nucleus, and VO, made significantly greater inputs to somatostatinpositive cells than to PV?cells. Diverse inputs to the LDT on a system-wide level were revealed.

One-nanometer-thick platinum-based nanowires with controllable surface structures

Pt-based ultrathin nanowires (NWs) are considered as one of the most intriguing catalysts for fuel cells.However,the delicate controllability of surface structure of ultrathin NWs to regulate their catalytic performances is still a challenge.Here,two kinds of one-nanometer-thick Pt-based NWs with smooth surfaces (S-NWs) and rough surfaces (R-NWs) are demonstrated,in which the combined use of hexadecyltrimethylammonium bromide and oleylamine plays an essential role,as they could form soft-templates to direct the growth of NWs.Due to its high-density of low-coordinated sites on the surface,Pt-based R-NWs exhibit higher oxygen reduction reaction (ORR) activities but lower stabilities than corresponding S-NWs.Notably,Pt0.78Ni0.22 R-NWs possess the highest mass activity (1.07 A-mgpt^-1) and specific activity (1.02 mA·cm^-2) among all Pt-based NWs.After 10,000 sweeping cycles,the mass activity still exhibits 5.7-fold enhancement compared to the corresponding commercial Pt/C.This work presents a new approach to delicately control the surface structure of ultrathin Pt-based NWs as advanced ORR catalysts.

Injury severity analysis of electric bike crashes in Changsha, Hunan Province: taking different lighting conditions into consideration

With the increasing use of electric bikes, electric bike crashes occur frequently. Analysing the influencing factors of electric bikecrashes is an effective way to reduce mortality and improve road safety. In this paper, spatial analysis is performed by geographicinformation system (GIS) to present the hot spots of electric bike crashes during daylight and darkness in Changsha, Hunan Province,China. Based on the Ordered Probit (OP) model, we studied the risk factors that led to different severities of electric bike crashes.The results show that the main influencing variables include age, illegal behaviour, collision type and road factors. During daylightand darkness, elderly electric bike riders over the age of 65 years have a higher probability of fatal crashes. Not following trafficsignals and reverse driving are significantly related to the severity of riders’ injuries. In darkness, frontal collisions are significantfactors causing rider injury. In daylight, more serious crashes will be caused in bend and slope road segments. In darkness, roadswith no physically separated bicycle lanes increases the risk of riders being injured. Electric bike crashes are mainly concentratedin the commercial, public service and residential areas in the main urban area. In suburbs at darkness, electric bike riders are morelikely to be seriously injured. Adding protectionmeasures, such as improved lighting, non-motorized lane facilities and interventionstargeting illegal behaviour in the hot spot areas can effectively reduce the number of electric bike crashes in complex traffic.

The genetic program Of oocytes can be modified in vivo in the zebrafish ovary

Oocytes,the irreplaceable gametes for generating a new organism,are matured in the ovary of living female animals.It is unknown whether any genetic manipulations can be applied to immature oocytes inside the living ovaries.As a proof-of-concept, we here demonstrate genetic amendments of zebrafish immature oocytes within the ovary.Oocyte microinjection in situ (OMIS) stimulates tissue repair responses,but some of the microinjected immature oocytes are matured,ovulated and fertilizable.By OMIS-mediated Cas9 approach,ntla and gata5 loci of oocytes arrested at prophase I of meiosis are successfully edited before fertilization.Through OMIS,high efficiency of biaUeUc mutations in single or multiple loci using Cas9/gRNAs allows immediate manifestation of mutant phenotypes in Fo embryos and multiple transgenes can co-express the reporters in Fo embryos with patterns similar to germline transgenic embryos.Furthermore,maternal knockdown of dnmt1 by antisense morphoino via OMIS results in a dramatic decrease of global DNA methylation level at the dome stage and causes embryonic lethalityprior to segmentation period.Therefore,OMIS opens a door to efficiently modify the genome and provides a possibility to re repair genetically abnormal oocytes in situ.