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Purpose: Cosmogenic isotopes, known for their diverse types and relatively long lifetimes, are frequently treated as significant backgrounds in neutrino experiments. Particularly in the correlation events of inverse beta decay (IBD) events of reactor neutrinos, addressing and removing ${}^9$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{9}$$\end{document}Li and ${}^8$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{8}$$\end{document}He background is necessary. Similarly, for elastic scattering (ES) events of solar neutrinos, isotopes such as ${}^{12}$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{12}$$\end{document}B and ${}^8$\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{8}$$\end{document}Li have significant impacts. This study aims to identify an appropriate method for reducing the backgrounds in neutrino experiments. Methods: In this paper, we conducted simulations of muon backgrounds in a liquid scintillator detector using Geant4 and explored the correlation between cosmogenic isotopes and muons. We introduced a novel method to distinguish cosmogenic isotopes from neutrino signals. Utilizing the relationship between the distance and time of spallation isotopes to muons and neutrons, we employed the TMVA (tools for multi-variable analysis) to distinguish neutrino signals from isotope backgrounds, achieving good performance. Results: Compared with the traditional veto method, the efficiency has been improved by 1% for correlated events and 18% for single-event signals at the same background level. Conclusion: This study presents a novel method for discriminating cosmogenic isotopic backgrounds, achieving a higher signal-to-noise ratio compared to traditional approaches, and showing good potential applicability to similar analyses in the future.

Together with the big datamovement,many organizations collect their own big data and build distinctive applications. In order to provide smart services upon big data, massive variable data should be well linked and organized to form Data Ocean, which specially emphasizes the deep exploration of the relationships among unstructured data to support smart services. Currently, almost all of these applications have to deal with unstructured data by integrating various analysis and search techniques upon massive storage and processing infrastructure at the application level, which greatly increase the difficulty and cost of application development. This paper presents D-Ocean, an unstructured data management system for data ocean environment. D-Ocean has an open and scalable architecture, which consists of a core platform, pluggable components and auxiliary tools. It exploits a unified storage framework to store data in different kinds of data stores, integrates batch and incremental processing mechanisms to process unstructured data, and provides a combined search engine to conduct compound queries. Furthermore, a so-called RAISE process modeling is proposed to support the whole process of Repository, Analysis, Index, Search and Environment modeling, which can greatly simplify application development. The experiments and use cases in production demonstrate the efficiency and usability of D-Ocean.

MiRNA-targeted therapy has become a hot topic in current cancer research. The key to this treatment strategy is to clarify the specific role of miRNA in cancer. However, the roles of some miRNAs acting as oncogenic or tumor suppressors are still controversial, which are influenced by different tumor types, even in the same cancer type. Hence, we designed a novel fluorescent nanoprobe based on polydopamine nanoparticles (PDA NPs) for simultaneously detecting caspase-3 and miRNA-34a within living cells. The specific role of miRNA-34a in different cancer cells could be further identified by studying the expression alterations of caspase-3 and miRNA-34a. Confocal imaging indicated that miRNA-34a indeed acted as a tumor suppressor in anticancer drug-treated MCF-7 and HeLa cells, where the effect of miRNA-34a remains controversial. The designed nanoprobe can offer a promising approach to ascertain the oncogenic or tumor-suppressing role of miRNA in different cancer cells with a simple visualization method, which has valuable implications for exploring the practicability of precision therapy focused on miRNA and evaluating the efficacy of new miRNA-targeted anticancer medications.

The successful application of electrochemiluminescence (ECL) in various fields required continuous exploration of novel ECL signal emitters. In this work, we have proposed a pristine ECL luminophor named NiRu MOFs, which owned extremely high and stable ECL transmission efficiency and was synthesized via a straightforward two-step hydrothermal pathway. The foundation framework of pure Ni-MOFs with the initial structure was layered-pillared constructed by the coordinated octahedrally divalent between nickel and terephthalic acid (BDC). The terephthalates were coordinated and pillared directly to the nickel hydroxide layers and the three-dimensional framework was formed, which had a weak ECL response strength. Then, the ruthenium pyridine complex was recombined with pure Ni-MOFs to produce NiRu MOFs and part of the introduced ruthenium was atomically dispersed in the layered-pillared structure through an ion-exchange method, which led to the ECL luminous efficiency being significantly boosted more than pure Ni-MOFs. In order to verify the superiority of this newly synthesized illuminant, an ECL immunoassay model has been designed, and the results demonstrated that it had extremely strong and steady signal output in practical application. This study realized an efficient platform in ECL immunoassay application with the limit of detection of 0.32 pg mL–1for neuron-specific enolase (NSE). Therefore, the approach which combined the pristine pure Ni-MOFs and the star-illuminant ruthenium pyridine complex would provide a convenient and meaningful solution for exploring the next-generation ECL emitters.

We present an in-depth theoretical, algorithmic, and computational study of a linear programming (LP) relaxation to the precedence constrained single-machine scheduling problem 1 [absolute value of prec] [Σ.sub.j][w.sub.j][C.sub.j] to minimize [...]

The successful use of electrochemiluminescence (ECL) in immunoassay for clinical diagnosis requires development of novel ECL signal probes. Herein, we report lanthanide (Ln) metal–organic frameworks (LMOFs) as ECL signal emitters in the ECL immunoassay. The LMOFs were prepared from precursors containing Eu (III) ions and 5-boronoisophthalic acid (5-bop), which could be utilized to adjust optical properties. Investigations of ECL emission mechanisms revealed that 5-bop was excited with ultraviolet photons to generate a triplet-state, which then triggered Eu (III) ions for red emission. The electron-deficient boric acid decreased the energy-transfer efficiency from the triplet-state of 5-bop to Eu (III) ions; consequently, both were excited with high-efficiency at single excitation. In addition, by progressively tailoring the atomic ratios of Ni/Fe, NiFe composites (Ni/Fe 1:1) were synthesized with more available active sites, enhanced stability, and excellent conductivity. As a result, the self-luminescent europium LMOFs displayed excellent performance characteristics in an ECL immunoassay with a minimum detectable limit of 0.126 pg mL–1, using Cytokeratins21-1 (cyfra21-1) as the target detection model. The probability of false positive/false negative was reduced dramatically by using LMOFs as signal probes. This proposed strategy provides more possibilities for the application of lanthanide metals in analytical chemistry, especially in the detection of other disease markers.

In this work, a simple ammonia evaporation process to obtain AgCl powder with arbitrary superwettability, without introducing any low-surface-free-energy modifier, was investigated. By controlling the recrystallization parameters of the ammonia evaporation process, AgCl crystals precipitated from AgCl–ammonia solution show different wettabilities ranging from superhydrophilicity, via hydrophilicity and hydrophobicity, to superhydrophobicity, with the same chemical composition and structure. Characterization of the obtained AgCl samples with different wettabilities confirms the decisive effect of particle size although light irradiation also causes their wettability transformation.

We have proposed a dual-quenching electrochemiluminescence (ECL) strategy which is based on tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+] as chromophores caged in three-dimensional (3D) zinc oxalate metal–organic frameworks [Ru(bpy)32+/zinc oxalate MOFs] for ultrasensitive detection of amyloid-β (Aβ). The three-dimensional chromophore connectivity in zinc oxalate MOFs provided a network for rapid excited-state energy transfer migration among Ru(bpy)32+units which shielded the chromophores from solvent molecules and led to a high-energy Ru emission efficiency. In addition, we found that both Au nanoparticles and NiFe-based nanocube MOFs could contribute to the reduction of the ECL intensity of the chromophore. The ECL emission spectra of 3D Ru(bpy)32+/zinc oxalate MOFs overlapped appropriately with the ultraviolet–visible (UV–vis) absorption spectra of Au@NiFe MOFs composites, which could trigger the resonance energy transfer (RET) behavior between Ru(bpy)32+/zinc oxalate MOFs (donor) and Au@NiFe MOFs (acceptor), achieving the dual-quenching effect of Ru(bpy)32+encapsulated in 3D zinc oxalate MOFs and significantly boosting the sensitivity of the Aβ detection immunosensor. In order to examine the clinical practicability, we have applied it to verify the content of Aβ solution ranging from 100 fg mL–1to 50 ng mL–1and obtained the calibration curve with high correlation coefficient, along with the low limit of detection of 13.8 fg mL–1. Above all, this work demonstrated an approach of constructing dual-quenching effect ECL immunosensors in whole 3D MOF systems and its application in ECL detection methodology.

The detection of insulin by electrochemical (EC) immunoassay is desirable but highly challenged due to the obstacle of improving its accuracy, especially in a single-response system. In this work, based on Cu7S4–Au as a dual signal indicator, we fabricated a dual-mode electrochemical immunoassay for insulin. Especially, Cu7S4presents a strong differential pulse voltammetry (DPV) signal for the electron transfer between Cu2+and Cu+, without the addition of K3[Fe(CN)6] or other electron transfer mediators. Furthermore, Cu7S4displays high sensitivity and high electrocatalytic activity toward the reduction of H2O2through chronoamperometry (CA). The introduction of Au nanoparticles can not only link on the surface of Cu7S4by the chemical bond of Au–SH, but also connect the second antibody (Ab2) by the chemical bond of Au–N. Due to the superior electroconductivity of Au nanoparticles and the synergistic effect between the Au nanoparticles and Cu7S4, a high sensitivity is achieved by means of DPV and CA. To improve the loading capacity of antibodies, nanofiber polyaniline covalently grafted graphene (GS–PANI) linked with Au nanoparticles (GS–PANI–Au) as the matrix material was prepared. Based on Cu7S4–Au as a double signal indicator, the developed EC immunoassay for insulin exhibits a wide linear response for insulin detection in the range from 0.1 pg/mL to 50 ng/mL, with a low detection limit of 35.8 and 12.4 fg/mL through DPV and CA modes, respectively. Furthermore, the immunosensor displays an excellent analytical capability for insulin and promises application in quantitative detection of other disease markers in clinical diagnosis.

A sandwich-type photoelectrochemical (PEC) immunosensor for detecting N-terminal pro-brain natriuretic peptide (NT-proBNP) was constructed on the basis of SnO2/SnS2/mpg-C3N4nanocomposites and PbS/SiO2, with the former as a photoactive matrix and the latter as an efficient quencher. SnO2/SnS2/mpg-C3N4was synthesized via in situ growth of SnO2and SnS2on mesoporous graphene like C3N4nanocomposites (mpg-C3N4). Specifically, SnO2/SnS2/mpg-C3N4exhibited intense PEC signal responses, which are tens of times stronger than its each single component. Because of its superior performance, SnO2/SnS2/mpg-C3N4was applied as a photoactive matrix and signal indicator for fabricating PEC immunosensor. Interestingly, the excellent PEC signals from SnO2/SnS2/mpg-C3N4could be reduced severely with the addition of PbS/SiO2. Hence, the secondary antibody bioconjugates (PbS/SiO2-Ab2) were prepared as an efficient quencher. The mechanism of the quench reaction was further discussed in detail. On the basis of the interaction between the matrix and the quencher, the NT-proBNP immunosensor was fabricated and a wide linear range of 0.1 pg·mL–1to 50 ng·mL–1was obtained with a low detection limit of 0.05 pg·mL–1. Additionally, the PEC immunosensor manifested good stability, reproducibility, and selectivity, which could underlie robust platforms for detecting multitudinous biomarkers or other targets of interest.

It has been a big challenge to separate oil slicks from oil-polluted water sources efficiently and in an environmentally friendly way. Three-dimensional (3D) hydrophobic and superoleophilic materials have great potential in water separation continually. In this study, we developed a facile two-step strategy for fixing functionalized nanoparticles on 3D complex macroscopic surfaces. By using commercial glue to immobilize different types of nanoparticles on the surfaces of various 3D objects, superhydrophobic copper foam, cotton wool, and polyurethane (PU) sponge with strong stability and excellent performance were prepared. Owing to flexible fixing with the glue, the prepared PU sponge remained superhydrophobic after 950 mechanical compression cycles, 250 cycles of absorption/squeezing, or soaking in n-dodecane for 60 h. The prepared PU sponge was applied to the rapid absorption of clean oil on a water surface, and the feasibility of separating mixed oil through capillary separation of cavernous bodies was examined. Furthermore, the method for loading nanoparticles onto a 3D structure can be used with many self-cleaning, flexible electrodes and catalysts.

This work describes a sandwich-type electrochemiluminescence (ECL) strategy for insulin detection by using Ru(bpy)32+as the luminophore which was encapsulated in the UiO-67 metal–organic framework (UiO-67/Ru(bpy)32+). Because UiO-67 possesses the characteristics of large specific surface area and porosity, more Ru(bpy)32+could be loaded onto its surface and holes, thus greatly improving the ECL efficiency. Furthermore, the ECL resonance energy transfer (ECL–RET) could occur between UiO-67/Ru(bpy)32+(ECL donor) and Au@SiO2nanoparticles (ECL acceptor), resulting in a conspicuously decreased ECL response. The ECL spectrum of UiO-67/Ru(bpy)32+which exhibited strong ECL intensity has suitable spectral overlap with the absorption spectrum of Au@SiO2, which further proved the occurrence of the ECL–RET action. The ECL intensity decreased with the increase of the concentration of insulin. In addition, the sandwich-type ECL immunosensor was applied to insulin detection, and the ECL decrease efficiency was found to be logarithmically related to the concentration of the insulin antigen in the range of 0.0025 to 50 ng mL–1with the limit of detection of 0.001 ng mL–1. Meanwhile, this work provides an important reference for the application of metal–organic frameworks in the ECL and ECL–RET study and also exhibits potential capability in the detection of other hormones.

We herein report a self-powered and renewable cytosensing device based on ZnO nanodisks(NDs)@g-C3N4quantum dots. The device features enhanced photoelectrochemical (PEC) activity compared to ZnO NDs or g-C3N4QDs alone. The enhanced PEC ability is attributed to the synergistic effect of the high visible light sensitivity of g-C3N4QDs and the staggered band alignment heterojunction structure with suitable band offset, which affords higher photoelectron transfer and separation efficiency. In addition, the hybridization of g-C3N4QDs further accelerates interfacial electron transfer and blocks recombination between electron donors and photogenerated holes. The device was applied to the detection of CCRF-CEM cells. By conjugation to Sgc8c aptamer, which preferentially interacts with membrane-bound PTK7 on CCRF-CEM membranes, capture of target CCRF-CEM cells resulted in a decrease in apparent power output, which was then exploited for the ultrasensitive detection of the target cells. This decrease in power output can be recovered by simply increasing the temperature to release the cells, thus recycling the cytosensing performance. The device displayed a linear relationship between the change of power output and the logarithm of the cell concentration from 20 to 20,000 cell/mL (R2= 0.9837) and a detection limit down to 20 cell/mL, as well as excellent selectivity and reproducibility. Thus, this ZnO NDs@g-C3N4QDs-based device exhibits high potential for the detection of CCRF-CEM cells.

In this study, an easy-to-use electrochemical sensor was developed for the quantitative detection of lead ions (Pb2+) and cadmium ions (Cd2+). Core-shell ferroferric oxide@polyaniline (Fe3O4@PANI) nanoparticles were used as a sensitive platform for the detection of Pb2+and Cd2+. Fe3O4with large specific surface area could increase the sensitivity for detection. PANI as a conductive polymer with excellent electronic conductivity not only improved the electron transport speed in the detection process, but also produced good chelation with heavy ions. PANI contains a large number of amino and imino groups on its surface, thereby improving the detection sensitivity. Under optimal experimental conditions, the linear range for the detection of Pb2+was from 0.1 to 104nmol L−1; the detection limit was 0.03 nmol L−1, error limit of LOD was 1.1% and LOQ was 0.09 nmol L−1. The calculated LOD value of Cd2+was 0.3 nmol L−1, the error limit of LOD was 1.5%, and LOQ was 0.9 nmol L−1. The prepared electrochemical sensor presented high sensitivity, good specificity and excellent stability; also, it is simple and easy to operate. This analysis strategy has a huge application prospect in the detection of other heavy metal ions.

AbstractMagnetic hydroxypropyl chitosan/graphene oxide (MHCGO) composites have been synthesized and employed as adsorbent for removal of lead ions from aqueous solution. X-ray powder diffraction, Fourier transform infrared spectrum, and scanning electron microscope showed that the MHCGO composites were fabricated successfully. The effects of adsorbent dosage, pH, and contact time on the adsorption of lead ions have been discussed, and the optimal adsorption conditions have been acquired. The results indicated that the adsorption of lead ions on MHCGO was dependent on pH with the optimum pH nearly 5.5. The adsorption process was fairly quick and the time to reach adsorption equilibrium is 100 min. The adsorption kinetics could be described by the pseudo-second-order model very well. Adsorption data fitted well with Freundlich model. The effect of temperature on lead ions adsorption was studied and was shown to be spontaneous.

Herein, a novel dual mode detection system of split-type photoelectrochemical (PEC) and visual immunoassay was developed to detect neuron specific enolase (NSE), which achieved simultaneous and reliable NSE detection due to the completely different signal readouts and transduction mechanism. Specifically, specific reactions of antigens and antibodies were performed in 96-microwell plates. Gold nanoparticle (Au NP)-loaded Fe3O4(Au@Fe3O4) NPs were used as secondary antibody markers and signal regulators, which could produce a blue-colored solution in the presence of 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2because of its peroxidase-like activity. Therefore, the visual detection of NSE was realized, making the results more intuitive. Meanwhile, the above biological process could also be used as part of the split-type PEC sensing platform. Oxidized TMB and Fe3+were consumptive agents of the electron donor, which both realized the double quenching of PEC signal generated by the SnO2/MgIn2S4/Zn0.1Cd0.9S composites. Owing to the waterfall band structure, SnO2/MgIn2S4/Zn0.1Cd0.9S composites partially absorb visible light and effectively inhibit the electron–hole recombination, thereby providing significantly enhanced and stable initial signal. On the basis of the multiple signal amplification strategy and the split-type mode, NSE could be sensitively detected with a low detection limit of 14.0 fg·mL–1(S/N = 3) and a wide linear range from 50.0 fg·mL–1to 50.0 ng·mL–1.

Abstract: The permutahedron of a poset is the convex hull of all incidence vectors of linear extensions. For the case ofN-sparse posets in which any five elements induce at most oneN we give a characterization of the permutahedron in terms of linear inequalities. This yields an LP-solution for minimizing the weighted mean completion time for jobs with unit processing times andN-sparse precedence constraints. We close with an extension of our approach to arbitrary processing times.

We introduce a projective approach for studying symmetric travelling salesman polytopes (STSPs). Thesymmetric travelling salesman polytope STSP(V) (resp.,Hamiltonian path polytope HP(V)) is the convex hull of incidence vectors of all Hamiltonian cycles (resp., paths) on the complete undirected graph with node setV. For any nodeh ?V, HP(V) is aprojection of STSP(V ? {h}). We show that HP(V) and STSP(V ? {h}) are isomorphic, and HP(V) is of full dimension minus one. By this projective approach, we obtain generalclique-lifting results, all based on simple conditions, for deriving large new classes of STSP facets. These results apply to all known non-trivial STSP facets, and generalize clique-lifting results of Maurras (1975), Grötschel and Padberg (1979) and Naddef and Rinaldi (1988).

Enzyme-histochemical demonstration of lymphatic vessels in the golden hamster periodontium was performed on cryostat sections using the 5'-nucleotidase (5'-Nase) staining method by light microscopy and backscattered electron imaging of scanning electron microscopy. The inhibition of the 5'-Nase activity by decalcification was cancelled by the Mg++ ion supply. The reaction products of 5'-Nase activity were produced on the lymphatic endothelial cells and the tubular structures of lymphatic vessels were seen as highlights by backscattered electron imaging. The invasion of 5'-Nasepositive lymphatic vessels into the alveolar bone from the periodontium was found in the present study.