Pt-Ni core-shell structure with Pt-skin and electronic effect on catalytic performance

In order to improve the catalytic performance of the nitrobenzene hydrogenation rearrangement to prepare p-aminophenol,a bimetallic Pt-Ni/C(PNC)catalyst was synthesized.Taking advantage of the synergistic effect of Ni and Pt to enhance product selectivity and catalytic performance stability,the electrons in Ni are moved to Pt by the electron effect,which affects the catalyst’s ability to activate H_(2)as well as the amount of hydrogen activated.Furthermore,due to the strong Pt(5d)-Ni(3d)coupling effect,Ni can effectively maintain Pt stability in the acidic system and reduce Pt dissolution.The stability of the PNC can be found to be greatly enhanced compared to the Pt/C(PC)catalyst,and p-aminophenol selectivity is greatly enhanced,showing excellent catalytic performance.

Tuning magneto-dielectric properties of Co_(2)Z ferrites via Gd doping for high-frequency applications

Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.

Overexpressed PKM2 promotes macrophage phagocytosis and atherosclerosis

Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global and myeloid cell-specific PKM2 knock-in mice with ApoE^(-/-)background(ApoE^(-/-),PKM2^(KI/KI)and Lyz2-cre,ApoE^(-/-),and PKM2^(flox/flox))were produced to evaluate the clinical significance of PKM2 in atherosclerosis development.Wild-type and PKM2 knock-in macrophages were isolated to assess the function of PKM2 in macrophage phagocytosis.Atherosclerotic mice were treated with PKM2 inhibitor shikonin(SKN)to evaluate the therapeutic potential of PKM2 suppression in atherosclerosis.Results:Oxidized low-density lipoprotein(oxLDL)upregulated PKM2 in macrophages.PKM2 in return promoted the uptake of oxLDL by macrophages.Overexpressed PKM2 accelerated atherosclerosis in mice.SKN blocked the progress of mouse atherosclerosis.Conclusions:PKM2 accelerates macrophage phagocytosis and atherosclerosis.Targeting PKM2 is a potential therapy for atherosclerosis.

rAAV/ABAD-DP-6His attenuates oxidative stressinduced injury of PC12 cells

Our previous studies have revealed that amyloidβ（Aβ）-binding alcohol dehydrogenase （ABAD） decoy peptide antagonizes Aβ42-induced neurotoxicity. However, whether it improves oxidative stress injury remains unclear. In this study, a recombinant adenovirus constitutively secreting and expressing Aβ-ABAD decoy peptide （rAAV/ABAD-DP-6His） was successfully constructed. Our results showed that rAAV/ABAD-DP-6His increased superoxide dismutase activity in hydro-gen peroxide-induced oxidative stress-mediated injury of PC12 cells. Moreover, rAAV/ABAD-DP-6His decreased malondialdehyde content, intracellular Ca2＋concentration, and the level of reactive oxygen species. rAAV/ABAD-DP-6His maintained the stability of the mitochondrial membrane potential. In addition, the ATP level remained constant, and apoptosis was reduced. Overall, the results indicate that rAAV/ABAD-DP-6His generates the fusion peptide, Aβ-ABAD decoy peptide, which effectively protects PC12 cells from oxidative stress injury induced by hy-drogen peroxide, thus exerting neuroprotective effects.

Lipidomics reveals carnitine palmitoyltransferase 1C protects cancer cells from lipotoxicity and senescence

Lipotoxicity, caused by intracellular lipid accumulation, accelerates the degenerative process of cellular senescence, which has implications in cancer development and therapy. Previously, carnitine palmitoyltransferase 1C(CPT1C), a mitochondrial enzyme that catalyzes carnitinylation of fatty acids, was found to be a critical regulator of cancer cell senescence. However, whether loss of CPT1C could induce senescence as a result of lipotoxicity remains unknown. An LC/MS-based lipidomic analysis of PANC-1,MDA-MB-231, HCT-116 and A549 cancer cells was conducted after siRNA depletion of CPT1C. Cellular lipotoxicity was further confirmed by lipotoxicity assays. Significant changes were found in the lipidome of CPT1C-depleted cells, including major alterations in fatty acid, diacylglycerol, triacylglycerol, oxidative lipids, cardiolipin, phosphatidylglycerol, phosphatidylcholine/phosphatidylethanolamine ratio and sphingomyelin. This was coincident with changes in expressions of mRNAs involved in lipogenesis.Histological and biochemical analyses revealed higher lipid accumulation and increased malondialdehyde and reactive oxygen species, signatures of lipid peroxidation and oxidative stress. Reduction of ATP synthesis, loss of mitochondrial transmembrane potential and down-regulation of expression of mitochondriogenesis gene m RNAs indicated mitochondrial dysfunction induced by lipotoxicity, which could further result in cellular senescence. Taken together, this study demonstrated CPT1C plays a critical role in the regulation of cancer cell lipotoxicity and cell senescence, suggesting that inhibition of CPT1C may serve as a new therapeutic strategy through induction of tumor lipotoxicity and senescence.

Clinical characteristics and prognosis of triple-negative breast cancer

客观我们调查了临床的特征，和三元组否定的乳癌的预示的因素。130 个三元组否定的乳癌病人在临床的特征和预后上被考察的方法。所有情况是免疫组织化学决定的雌激素受体，孕酮受体，和 HER2/neu 的表示的缺乏。结果 17.1% 所有乳癌病人(774 个案例) 是三元组否定的乳癌，并且 68.9% 三元组否定的乳癌病人(91 个案例) 是绝经前的。53.8% 病人(71 个案例) 与 T2 尺寸有肿瘤，并且(52 个病人) 他们中的 39.4% 个有淋巴节点转移。没有淋巴节点转移，在有淋巴节点转移的病人的恶化的率在病人显然比那高(P = 0.001 ) 。后续的中部的时间是 63 个月。33 案例 relapsed 和 20 个病人死了。23 个病人有至少二机关转移。5 年的没有疾病、全面的幸存率是 73.8% 和 85.7% 。结论三元组否定的乳癌病人通常在治疗以后在 2 3 年里有多重远转移的高率。淋巴节点的地位是最重要的预示的因素。有淋巴节点转移的三元组否定的胸 caner 病人有差的预后。

Construction of hollow polydopamine nanoparticle based drug sustainable release system and its application in bone regeneration

Nanomaterial-based drug sustainable release systems have been tentatively applied to bone regeneration.They,however,still face disadvantages of high toxicity,low biocompatibility,and low drug-load capacity.In view of the low toxicity and high biocompatibility of polymer nanomaterials and the excellent load capacity of hollow nanomaterials with high specific surface area,we evaluated the hollow polydopamine nanoparticles(HPDA NPs),in order to find an optimal system to effectively deliver the osteogenic drugs to improve treatment of bone defect.Data demonstrated that the HPDA NPs synthesized herein could efficiently load four types of osteogenic drugs and the drugs can effectively release from the HPDA NPs for a relatively longer time in vitro and in vivo with low toxicity and high biocompatibility.Results of qRT-PCR,ALP,and alizarin red S staining showed that drugs released from the HPDA NPs could promote osteogenic differentiation and proliferation of rat bone marrow mesenchymal stem cells(rBMSCs)in vitro.Image data from micro-CT and H&E staining showed that all four osteogenic drugs released from the HPDA NPs effectively promoted bone regeneration in the defect of tooth extraction fossa in vivo,especially tacrolimus.These results suggest that the HPDA NPs,the biodegradable hollow polymer nanoparticles with high drug load rate and sustainable release ability,have good prospect to treat the bone defect in future clinical practice.

The Error Estimates of Direct Discontinuous Galerkin Methods Based on Upwind-Baised Fluxes

In this paper, we study the error estimates for direct discontinuous Galerkin methods based on the upwind-biased fluxes. We use a newly global projection to obtain the optimal error estimates. The numerical experiments imply that L2 norms error estimates can reach to order k + 1 by using time discretization methods.

Microstructural,magnetic and dielectric performance of rare earth ion(Sm^(3+))-doped MgCd ferrites

The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric permittivity.Various concentrations of Sm^(3+)(x=0,0.03,0.06,0.09,0.12and 0.15)were employed to modify the permeability(μ)and permittivity(ε)of the Mg Cd ferrites.X-ray diffraction,scanning electron microscopy(SEM),vibrating sample magnetometry and vector network analysis techniques were used to characterize the samples.The measurement results reveal that the ferrites processed a saturation magnetization of up to 36.8 emu/g and coercivity of up to 29.2 Oe via the conventional solid-state reaction method.The surface morphology SEM confirms that with increasing Sm^(3+)concentration,the grain shape changes from a polygon to a circle.Moreover,the dielectric permittivity can reach a value of 23.The excellent properties obtained in Sm^(3+)-substituted Mg ferrites suggest that they could be promising candidates for modern high-frequency antenna substrates or multilayer devices.

A Model for Capacity Considering the Interference by Pedestrian Traffic at Signal Intersections

The capacity is impacted badly by pedestrians' violation behavior at signal intersections. In order to quantify the impact,the time-headway and the vehicular speed from start-up to reach the stable saturation flow with and without pedestrian traffic are used as the direct measurements. Using the statistical analysis,the timeheadway of saturation flow is mainly affected by the position of pedestrians and the degree of pedestrians 'influence is classified into four levels. Then the speed-time profile for the vehicular acceleration at each level is fitted by Curve Fitting Software. Based on the effect to the time-headway and acceleration time,the model of capacity influenced by pedestrians is established and the influence is quantified, which enriches the fundamental theory of traffic engineering. The result shows that the vehicular capacity can be decreased by 14%at the worst case( level I). The conclusions obtained in this paper are valuable for better management of the signal intersection.

Impact of Pedestrian Traffic on Saturation Rate of Protected Left-Turn at Urban Intersections

Heavily congested intersections in metropolitan areas in China are facing unique problems due to high travel demand and a high degree of traffic law violations. Based on a study conducted by the authors of this paper, 93% of left-turn vehicles turning left in these areas were slowed in order to avoid conflict with pedestrians. Intertwined pedestrian and vehicular flows can significantly reduce the capacity of exclusive left-turn lane group through reducing saturation flow rate, which increases the congestion at intersections. This paper investigates how the saturation flow rate of exclusive left-turn lane group is affected by the characteristics of pedestrian flow. By analyzing the imagery data collected by video cameras installed at intersections, the research team is able to obtain the characteristics of both vehicular and pedestrian flows, such as speed and spatial locations. The average operating speed at the saturation flow rate with and without pedestrian traffic is used as a direct measurement to evaluate the effect of pedestrians. Based on the statistical analysis, the paper concludes that saturation flow rate is mainly affected by the position of pedestrian in the crosswalk (inside or outside of left-turn vehicle’s trajectory), and the distance between the vehicle and pedestrians. In general, when the distance is less than four meters, the smaller the distance between vehicle and pedestrians, the larger the impact. However, there is no significant impact when the distance is larger than four meters. To accurately quantify the effect, the degree of pedestrian-vehicle impact is defined in four levels. The results show that the difference in the saturation flow rate between the best and the worst level could be 15.7%, which clearly indicates how important it is to enforce pedestrian crossing behavior.

Model of Traffic Speed-Flow Relationship at Signal Intersections

Speed-flow relationship is the fundamental for the traffic simulation and traffic volume forecast. Traditional quadratic polynomial model can’t reflect the saturate flow at signal intersections. In order to determine the speed-flow relationship at signal intersections, the speed and time-headway of vehicles at two signal intersections were investigated and the accuracy of software used to get the speed was tested. After vehicle starting-up from queuing, the time-headway reduces gradually with the increase of speed. The relationship of power exponential function between speed and time-headway is formulated. Traffic volume can be calculated by the vehicle time-headway. Then the speed-flow relationship was developed and an S-shaped curve model was built in this paper. In the S-shaped curve model, traffic flow approaches to the saturate when the speed doesn’t increase. Thus, S-shaped curve model is better to describe the speed-flow relationship at signal intersection. The results can provide a reference to determine the parameters in traffic simulation and for the study of level of service of intersections.

变翼展的仿生扑翼尾迹特征

本文基于仿生扑翼流动的数值模拟研究变形翼展对尾迹结构的影响.所采用的扑翼模型为一个在均匀来流中上下扑动的平板.翼展随着扑动而变化,最大翼展在下扑行程的中间,最小翼展在上挥行程的中间.其尾迹的特征表现为两条相互连接的倾斜涡链.虽然变形翼展对尾流拓扑结构的影响不大,但它显著影响了扑翼附近涡结构,导致尾流中涡环链的分布不对称.下扑过程中,位于扑翼下表面的前缘涡收缩,与上挥中翼尖涡相互作用,通过分析升力系数,发现上述涡的相互作用是由翼展长度的变化引起的.

Use of recombinant microRNAs as antimetabolites to inhibit human non-small cell lung cancer

During the development of therapeutic microRNAs(miRNAs or miRs),it is essential to define their pharmacological actions.Rather,miRNA research and therapy mainly use miRNA mimics synthesized in vitro.After experimental screening of unique recombinant miRNAs produced in vivo,three lead antiproliferative miRNAs against human NSCLC cells,miR-22-3p,miR-9-5p,and miR-218-5p,were revealed to target folate metabolism by bioinformatic analyses.Recombinant miR-22-3p,miR-9-5p,and miR-218-5p were shown to regulate key folate metabolic enzymes to inhibit folate metabolism and subsequently alter amino acid metabolome in NSCLC A549 and H1975 cells.Isotope tracing studies further confirmed the disruption of one-carbon transfer from serine to folate metabolites by all three miRNAs,inhibition of glucose uptake by miR-22-3p,and reduction of serine biosynthesis from glucose by miR-9-5p and-218-5p in NSCLC cells.With greater activities to interrupt NSCLC cell respiration,glycolysis,and colony formation than miR-9-5p and-218-5p,recombinant miR-22-3p was effective to reduce tumor growth in two NSCLC patient-derived xenograft mouse models without causing any toxicity.These results establish a common antifolate mechanism and differential actions on glucose uptake and metabolism for three lead anticancer miRNAs as well as antitumor efficacy for miR-22-3p nanomedicine,which shall provide insight into developing antimetabolite RNA therapies.

珠江河口区大型底栖动物群落结构

河口区大型底栖动物具有的重要群落特征往往可以反映群落所经历的环境污染。为更好地了解珠江河口区大型底栖动物群落结构,作者于2014年11月至2015年8月进行了4个季度的大型底栖动物调查,并利用PRIMER 6.0软件进行群落生物多样性指数计算、群落等级聚类(Cluster)和非度量多维标度排序(nMDS)分析。研究结果显示:珠江河口区共获得大型底栖动物52种,优势种包括光滑河篮蛤(Potamocorbulalaevis)、中国绿螂(Glaucomya chinensis)、焦河篮蛤(Potamocorbulaustulata)和羽须鳃沙蚕(Dendronerispinnaticirrus)。大型底栖动物年平均密度为269.3 ind./m^2,年平均生物量为129.61g/m^2。12个站次的丰富度指数(D)、均匀度指数(J’)和Shannon-Wiener多样性指数(H’)平均值分别为1.81±1.38、0.50±0.27和1.60±1.13。该结果显示除P01断面的秋季和冬季环境质量为优良外,其他站位在不同季度都显示出轻度到重度的污染。Cluster聚类分析和n MDS标序结果表明, P01断面与P02和P03断面群落相似度较低,与断面地理分布情况一致;P02断面和P03断面存在交叉聚集,群落相似度较高。结合环境因子结果可知,沉积物理化因子与群落分布特征相关性较大,其中最能解释珠江河口区群落多样性分布特征的环境因子为盐度和pH值。

一种可快速、持久且广谱保护新冠病毒感染的鼻喷减毒流感病毒载体新冠病毒疫苗

肌注式新冠病毒疫苗在呼吸道局部诱导的免疫应答较有限,不能高效阻止新冠病毒入侵呼吸道细胞.为此,该研究利用双重减毒的流感病毒载体(CA4-d NS1)开发出一种携带新冠病毒RBD基因的可经鼻腔喷雾方式接种的新冠病毒疫苗CA4-dNS1-nCoV-RBD(简称dNS1-RBD).该疫苗在重症新冠肺炎仓鼠模型中表现出良好的保护效果,鼻喷接种1天后即可快速起效,两剂次鼻喷接种后可提供9个月以上的长效保护,表现为疫苗组仓鼠的体重未见明显下降,肺组织病理无明显损伤.该疫苗对Omicron等各种新冠病毒关切突变株均有广谱作用.另外,小鼠实验显示该疫苗还可广谱保护H1N1和H5N1流感病毒感染.该疫苗的保护机制涉及呼吸道局部的先天免疫应答、特异性T细胞应答、粘膜Ig A抗体应答和体液Ig G抗体应答等.总之,该研究表明快速、持久且广谱的鼻喷流感载体新冠病毒疫苗可与现有肌注式新冠病毒疫苗形成互补,共同抗击新冠疫情.

Much late onset of Quaternary glaciations on the Tibetan Plateau:determining the age of the Shishapangma Glaciation using cosmogenic 26Al and 10Be dating

The onset of Quaternary glaciations is a critical event in the climate and tectonic history of the Tibetan Plateau.The Shishapangma Glaciation,defined based on the till deposit from the northern slopes of Mt.Shishapangma,has been identified as the oldest glaciation on the Tibetan Plateau.However,the timing of this glaciation has not been constrained.We measured^(10)Be and^(26)Al concentrations of a set of boulders on top of this till and simulated their complex exposure-burial histories.The simulated results indicate that the formation age of this till is likely around 835.2±241.0 ka,representing the minimum timing of glacial onset on the Tibetan Plateau.The Shishapangma Glaciation is apparently much younger than the glacial onset in many other areas of the world,such as Europe and North America,and was likely driven by the coupled effect between tectonic uplift and climate cooling during the early–middle Pleistocene transition.

SIRT6 as a key event linking P53 and NRF2 counteracts APAP-induced hepatotoxicity through inhibiting oxidative stress and promoting hepatocyte proliferation

Acetaminophen(APAP)overdose is the leading cause of drug-induced liver injury,and its prognosis depends on the balance between hepatocyte death and regeneration.Sirtuin 6(SIRT6)has been reported to protect against oxidative stress-associated DNA damage.But whether SIRT6 regulates APAPinduced hepatotoxicity remains unclear.In this study,the protein expression of nuclear and total SIRT6 was up-regulated in mice liver at 6 and 48 h following APAP treatment,respectively.Sirt6 knockdown in AML12 cells aggravated APAP-induced hepatocyte death and oxidative stress,inhibited cell viability and proliferation,and downregulated CCNA1,CCND1 and CKD4 protein levels.Sirt6 knockdown signifi-cantly prevented APAP-induced NRF2 activation,reduced the transcriptional activities of GSTm andNQO1 and the m RNA levels of Nrf2,Ho-1,Gsta and Gstm.Furthermore,SIRT6 showed potential protein interaction with NRF2 as evidenced by co-immunoprecipitation(Co-IP)assay.Additionally,the protective effect of P53 against APAP-induced hepatocytes injury was Sirt6-dependent.The Sirt6 m RNA was significantly down-regulated in P53à/àmice.P53 activated the transcriptional activity of SIRT6 and exerted interaction with SIRT6.Our results demonstrate that SIRT6 protects against APAP hepatotoxicity through alleviating oxidative stress and promoting hepatocyte proliferation,and provide new insights in the function of SIRT6 as a crucial docking molecule linking P53 and NRF2.

Gender associates with both susceptibility to infection and pathogenesis of SARS-CoV-2 in Syrian hamster

Epidemiological studies of the COVID-19 patients have suggested the male bias in outcomes of lung illness.To experimentally demonstrate the epidemiological results,we performed animal studies to infect male and female Syrian hamsters with SARS-CoV-2.Remarkably,high viral titer in nasal washings was detectable in male hamsters who presented symptoms of weight loss,weakness,piloerection,hunched back and abdominal respiration,as well as severe pneumonia,pulmonary edema,consolidation,and fibrosis.In contrast with the males,the female hamsters showed much lower shedding viral titers,moderate symptoms,and relatively mild lung pathogenesis.The obvious differences in the susceptibility to SARS-CoV-2 and severity of lung pathogenesis between male and female hamsters provided experimental evidence that SARS-CoV-2 infection and the severity of COVID-19 are associated with gender.

Achieving data-driven actionability by combining learning and planning

A main focus of machine learning research has been improving the generalization accuracy and efficiency of prediction models. However, what emerges as missing in many applications is actionability, i.e., the ability to turn prediction results into actions. Existing effort in deriving such actionable knowledge is few and limited to simple action models while in many real applications those models are often more complex and harder to extract an optimal solution. In this paper, we propose a novel approach that achieves actionability by combining learning with planning, two core areas of AI. In particular, we propose a framework to extract actionable knowledge from random forest, one of the most widely used and best off-the-shelf classifiers. We formulate the actionability problem to a sub-optimal action planning （SOAP） problem, which is to find a plan to alter certain features of a given input so that the random forest would yield a desirable output, while minimizing the total costs of actions. Technically, the SOAP problem is formulated in the SAS＋ planning formalism, and solved using a Max-SAT based ap- proach. Our experimental results demonstrate the effectiveness and efficiency of the proposed approach on a personal credit dataset and other benchmarks. Our work represents a new application of automated planning on an emerging and challenging machine learning paradigm.