Probabilistic Analysis of a Robot System with Redundant Safety Units and Common-Cause Failures

This paper presents reliability and availability analyses of a model representing a system having one robot and n-redundant safety units with common-cause failures. At least k safety units must function successfully for the robot system success. The robot and other failure rates and the partially failed system repair rates are assumed constant and the failed robot-safety system repair time is assumed arbitrarily distributed. Markov and supplementary variable methods were used to perform mathematical analysis of this model. Generalized expressions for state probabilities, system availabilities, reliability, mean time to failure, and variance of time to failure are developed. Plots of some resulting expressions are shown.

Removal of Microcystin-LR in lake water sample by hydrophilic mesoporous silica composites under high-throughput MALDI-TOF MS detection platform

Microcystins(MCs),a family of cyclic heptapeptide cyanotoxins,exists in aquatic environment where cyanobacterial bloom happens,which will accumulate in aquatic organisms and transfer through the food chain to higher trophic levels,posing a health risk to both animals and human bodies.Among various MCs,Microcystin-LR(MC-LR)is worthiest studied for its strong toxicity,ubiquity and widespread.Here in this work,iminodiacetic acid(IDA)decorated magnetic mesoporous silica(mSiO_(2))nanocomposites(Fe_(3)O_(4)@mSiO_(2)-IDA)were facilely synthesized which possessed the merits of large surface area(188.21 m^(2)/g),accessible porosity(2.66 nm),excellent hydrophilicity and rapid responsiveness to magnetic field.Then the composites were successfully employed to the removal process of Microcystin-LR in real water samples followed by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS)analysis,achieving the removal efficiency above 92.5%even after ten recycles of the composites.It provided a potential method for removing MC-LR in aqueous environment with high effectiveness,lower costs and less secondary contamination.

Similarity of regulatory network between leukaemia stem cells and normal hemopoietic stem cells

Few studies have deeply compared the expression profiles between normal hematopoietic cells and acute myeloid leukaemia(AML) blasts. To reveal the biology of AML, we compared gene expression profiles between normal hematopoietic cells from 38 healthy donors and leukemic blasts(LBs) from 26 AML patients. Normal hematopoietic samples included CD34+ selected cells, unselected bone marrows(BMs), and unselected peripheral bloods(PBs). Gene expression profile of normal hematopoietic cells from healthy donors and LBs from AML patients were compared to identify differentially expressed genes(DEGs). We defined the comparison of LB and unselected BM as experiment 1, LB and CD34+ isolated from BM as experiment 2, LB and unselected PB as experiment 3, as well as LB and CD34+ isolated from PB as experimen4. Then, protein-protein interaction(PPI) network of DEGs was constructed to identify critical genes. Regulatory impac factors(RIF) was used to identify critical transcription factors(TFs) from the differential co-expression network constructed via re-analyzing the microarray profile from the perspective of differential co-expression. GO(Gene Ontology) enrichmen was performed to extract biological meaning. The comparison among the number of DEGs obtained in the four experiments showed LB cells did not tend to differentiation and CD34+ was more similar to cancer stem cells. Based on the results of PP network, CREBBP, F2 RL1, MCM2 and TP53 were respectively the key genes in experiment 1, 2, 3, and 4. For GO analysis, we found that immune response was the common one in these four stages. Our results might provide a platform for determining the pathology and therapy of AML.

Nucleate Pool Boiling Heat Transfer of Pure Refrigerants and Binary Mixtures

Heat transfer coefficients in nucleate boiling on a smooth flat surface were measured for pure fluids of R-134a, propane, isobutane and their binary mixtures at different pressure from 0.1 to 0.6 MPa. Series of experiments with different heat flux and mixture concentrations were carried out. The influences of pressure and heat flux on the heat transfer coefficient for different pure fluids were studied. Isobutane and propane were used to make up binary mixtures. Compared to the pure components, binary mixtures show lower heat transfer coefficients. This reduction was more pronounced as the heat flux increasing. Several heat transfer correlations are obtained for different pure refrigerants and their binary mixtures.

Low-cost and low-density carbonized facial tissue supported uniform NiCo_(2)S_(4)nanotubes for high capacity flexible solid-state supercapacitors

Recently,rapid development of intelligent wearable electronic equipment has triggered great needs for flexible and lightweight portable energy storage systems.Here,we demonstrate a low-cost($0.5 m^(-2))and low density carbonized facial tissue paper(FCP)for high-conductive NiCo_(2)S_(4)nanotubes assisted novel ultra-flexible solid-state supercapacitors(SSCs).The hydrothermal synthesized FCP-900@NiCo_(2)S_(4)electrodes in this paper only have a density of 5 mg cm^(-2)and show large specific capacitance of 3115 mF cm^(-2)at 2 mA cm^(-2).Based on the high performance of FCP-900@NiCo_(2)S_(4)electrodes,the as assembled SSCs can deliver an energy density of 1.2 mWh cm^(-3),high power density of 58.16 mW cm-3.It also shows great bending-state capacitive performance with high capacitance retention after 5000 cycles,providing a new opportunity for developing high-performance flexible wearable energy storage devices.

Stepwise construction of Pt decorated oxygen-deficient mesoporous titania microspheres with core-shell structure and magnetic separability for efficient visible-light photocatalysis

Solid photocatalysts with high specific surface area,superior photoactivity and ease of recycling are highly desired in chemical process,water treatment and so on.In this study,a facile stepwise sol-gel coating approach was utilized to synthesize Pt decorated oxygen-deficient mesoporous titania microspheres with core-shell structure and convenient magnetic separability(denoted as Fe3 O4@-SiO2@Pt/mTiO2-x).These photocatalysts consist of magnetic Fe3 O4 cores,nonporous insulating SiO2 middle layer and mesoporous anatase TiO2-x shell decorated by Pt nanoparticles(~3.5 nm)through wet impregnation and H2 reduction.As a result of high activity of oxygen-deficiency of black TiO2-x by H2 reduction and efficient inhibition of electron-hole recombination by Pt nanoparticles,the rationally designed core-shell Fe3 O4@SiO2@Pt/mTiO2-x photocatalysts exhibit superior photocatalytic performance in rhodamine B(RhB)degradation under visible light irradiation,with more than 98%of RhB degraded within 50 min.These core-shell structured photocatalysts show excellent recyclability under the assistance of magnetic separation with well-retained photocatalytic performance even after running five cycles.This stepwise synthesis method paves the way for the rational design of a high-efficiency recyclable heterogeneous catalyst,including photocatalysts,for various applications.

Potassium tantalate niobate crystals:Efficient quadratic electro-optic materials and their laser modulation technology

Electro-optic(EO)crystals are important material for all-solid-state laser technology,which can be used to fabricate various laser modulators,such as EO switches,laser deflectors,and optical waveguide.The improvements in new high-efficiency EO crystal materials have held great significance to the development of laser technology.Potassium tantalate niobate(KTN)is a popular multifunctional crystal because of its remarkable and excellent quadratic EO effect.KTN EO modulation technology offers numerous advantages,such as high efficiency,good stability,a quick response time,and inertia-free characteristics.In this paper,we summarize the research progress of KTN series crystals systemically,including the theoretical exploration on quadratic EO effect,solid-melt crystal growth technique,comprehensive physical characterization,new physical effect and mechanisms exploration,new EO devices development and design.The EO modulation technique based on the Kerr effect of KTN series crystal offers obvious advantages in reducing the drive voltage and device size,which could better meet the developmental needs of future lasers with a wide wavelength,miniaturization,and integration.This may provide theoretical guidance and an experimental basis for the design and development of new EO crystal devices and promote the development of laser technology.

Enhancing the Intermolecular Interactions of Ladder-Type Heteroheptacene-Based Nonfullerene Acceptors for Efficient Polymer Solar Cells by Incorporating Asymmetric Side Chains

Asymmetric nonfullerene acceptors(NFAs)possess larger dipole moments and stronger intermolecular bonding energy than their symmetric counterparts thereby making them promising candidates for high-performance polymer solar cells(PSCs).Herein,we report twoefficient acceptor–donor–acceptor(A–D–A)type NFAs(M14 and M18)with asymmetric side chains that show enhanced intermolecular interactions compared with their corresponding counterparts(M17 and M19)based on symmetric side chains.Furthermore,M14 and M18 exhibit elevated lowest unoccupiedmolecular orbitals and smallerπ–πstacking distances in comparison with M17 and M19,respectively.In combination with the benchmark polymer donor of PM6,the PM6:M14 blend affords superior charge transport properties,and more importantly,an increased power conversion efficiency(PCE)of 15.49%in comparison with the M17-based counterpart(13.01%PCE).Similarly,the asymmetric M18-based blend also shows a higher PCE of 13.00%than the M19-based blend(11.55%).Through further interface engineering,the bestperforming M14-based device delivers an enhanced PCE of 16.46%,which represents a record value among all asymmetric A–D–A type NFAs.Our results provide new insights into the design of asymmetric NFAs with enhanced intermolecular interactions for highperformance PSCs.

A small molecule inhibitor of the UBE2F-CRL5 axis induces apoptosis and radiosensitization in lung cancer

Protein neddylation is catalyzed by a neddylation activating enzyme(NAE,E1),an E2 conjugating enzyme,and an E3 ligase.In various types of human cancers,the neddylation pathway is abnormally activated.Our previous study validated that the neddylation E2 UBE2F is a promising therapeutic target in lung cancer.Although the NAE inhibitor MLN4924/pevonedistat is currently under clinical investigation as an anti-cancer agent,there are no small molecules available that selectively target UBE2F.Here,we report,for the first time,the discovery,via structure-based virtual screen and chemical optimization,of such a small molecule,designated as HA-9104.HA-9104 binds to UBE2F,reduces its protein levels,and consequently inhibits cullin-5 neddylation.Blockage of cullin-5 neddylation inactivates cullin-RING ligase-5(CRL5)activity,leading to accumulation of the CRL5 substrate,NOXA,to induce apoptosis.Moreover,HA-9104 appears to form the DNA adduct via its 7-azaindole group to induce DNA damage and G2/M arrest.Biologically,HA-9104 effectively suppresses the growth and survival of lung cancer cells and confers radiosensitization in both in vitro cell culture and in vivo xenograft tumor models.In summary,we discovered a small molecule,designated HA-9104,that targets the UBE2F-CRL5 axis with anti-cancer activity alone or in combination with radiation.

Green flexible electronics based on starch

Flexible electronics(FEs)with excellent flexibility or foldability may find widespread applications in the wearable devices,artificial intelligence(AI),Internet of Things(IoT),and other areas.However,the widely utilization may also bring the concerning for the fast accumulation of electronic waste.Green FEs with good degradability might supply a way to overcome this problem.Starch,as one of the most abundant natural polymers,has been exhibiting great potentials in the development of environmental-friendly FEs due to its inexpensiveness,good processability,and biodegradability.Lots of remarks were made this field but no summary was found.In this review,we discussed the preparation and applications of starch-based FEs,highlighting the role played by the starch in such FEs and the impacts on the properties.Finally,the challenge was discussed and the outlook for the further development was also presented.

Removal of fluoride from water using titanium-based adsorbents

Three adsorbents including TiO_(2),Ti-Ce,and Ti-La hybrid oxides were prepared to remove fluoride from aqueous solution.The Ti-Ce and Ti-La hybrid adsorbents obtained by the hydrolysis-precipitation method had much higher sorption capacity for fluoride than the TiO_(2) adsorbent prepared through hydrolysis.Rare earth(Ce and La)oxides and TiO_(2) exhibited a synergistic effect in the hybrid adsorbents for fluoride sorption.The sorption equilibrium of fluoride on the three adsorbents was achieved within 4 h,and the pseudo-second-order model described the sorption kinetics well.The sorption isotherms fitted the Langmuir model well,and the adsorption capacities of fluoride on the Ti-Ce and Ti-La adsorbents were about 9.6 and 15.1 mg·g^(-1),respectively,at the equilibrium fluoride concentration of 1.0 mg·L^(-1),much higher than the 1.7 mg·g^(-1) on the TiO_(2).The sorption capacities of fluoride on the three adsorbents decreased significantly when the solution pH increased from 3 to 9.5.The electrostatic interaction played an important role in fluoride removal by the three adsorbents,and Fourier transform infrared(FTIR)analysis indicated that the hydroxyl groups on the adsorbent surface were involved in fluoride adsorption.

Protein neddylation and its role in health and diseases

NEDD8(Neural precursor cell expressed developmentally downregulated protein 8)is an ubiquitin-like protein that is covalently attached to a lysine residue of a protein substrate through a process known as neddylation,catalyzed by the enzyme cascade,namely NEDD8 activating enzyme(E1),NEDD8 conjugating enzyme(E2),and NEDD8 ligase(E3).The substrates of neddylation are categorized into cullins and non-cullin proteins.Neddylation of cullins activates CRLs(cullin RING ligases),the largest family of E3 ligases,whereas neddylation of non-cullin substrates alters their stability and activity,as well as subcellular localization.Significantly,the neddylation pathway and/or many neddylation substrates are abnormally activated or over-expressed in various human diseases,such as metabolic disorders,liver dysfunction,neurodegenerative disorders,and cancers,among others.Thus,targeting neddylation becomes an attractive strategy for the treatment of these diseases.In this review,we first provide a general introduction on the neddylation cascade,its biochemical process and regulation,and the crystal structures of neddylation enzymes in complex with cullin substrates;then discuss how neddylation governs various key biological processes via the modification of cullins and non-cullin substrates.We further review the literature data on dysregulated neddylation in several human diseases,particularly cancer,followed by an outline of current efforts in the discovery of small molecule inhibitors of neddylation as a promising therapeutic approach.Finally,few perspectives were proposed for extensive future investigations.