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The flow-field structure and pressure gain performance of a rotating detonation engine with banded distribution of reactants have been studied using two-dimensional numerical simulations. The reactants are premixed H2/Air mixture. An unsteady reacting flow solver named rhoHLLCFoam is developed based on the open source software OpenFOAM. Unsteady Reynolds Averaged Navier-Stokes (RANS) equations are solved with second order accuracy in space and time with Harten-Lax-van-Leer-Contact (HLLC) Riemann scheme. The solver resolves the combustion phenomena through finite rate chemistry reaction model with Arrhenius form of reaction rate by using O Conaire scheme. After checking the reliability of the solver, two sets of cases with various inlet-area ratios (ψ) and equivalence ratios (ϕ) are conducted. The result shows that with ψ 1.0 , the reactants in front of detonation waves present a discretely banded distribution which causes a series of reverse compression waves in flow-field. This paper estimates the specific impulse and specific thrust of combustion chamber. It's shown that these parameters increase with the promotion of ψ. By calculating the area-averaged stagnation pressure along axial direction of combustion chamber, the pressure gain ratio (η) of the rotating detonation engine is estimated. The result suggests that η decreases dramatically with the reduction of ψ. In order to achieve pressure gain, ψ must be greater than 0.60. Moreover, the equivalence ratio should be around unity to obtain higher value of η.

Recent years have witnessed an increasing interest in the processing-in-memory (PIM) paradigm in computing due to its promise to improve the performance through the reduction of energy-hungry and long-latency memory accesses. Joined with the explosion of data to be processed, produced in genomics - particularly genome sequencing - PIM has become a potential promising candidate for accelerating genomics applications since they do not scale up well in conventional von Neumann systems. In this article, we present an in-memory accelerator architecture for DNA read alignment. This architecture outperforms corresponding software implementation by >49X and >18 000X, in terms of throughput and energy efficiency, respectively, even under conservative assumptions.

This article presents a method for analyzing the parasitic effects of interconnects on the performance of the STT-MTJ-based computational random access memory (CRAM) in-memory computation platform. The CRAM is a platform that makes a small reconfiguration to a standard spintronics-based memory array to enable logic operations within the array. The analytical method in this article develops a methodology that quantifies the way in which wire parasitics limit the size and configuration of a CRAM array and studies the impact of cell- and array-level design choices on the CRAM noise margin. Finally, the method determines the maximum allowable CRAM array size under various technology considerations.

Recently, low-dimensional organic-inorganic lead halide perovskites have attracted a great deal of attention due to their outstanding tunable broadband emission, while the toxicity of lead hinders their further application in the photoelectric field. Here, we report a novel lead-free Cu(I)-based organic-inorganic perovskite-related material of a (MA)4Cu2Br6 single crystal with zero-dimensional clusters, which is a unique Cu2Br64- corner-sharing tetrahedron dimer structure consisting of two connected tetrahedra. The single crystal displays a bright broadband green emission with a high photoluminescence with a quantum yield of ≤93%, a large Stokes shift, and a very long (microsecond) photoluminescence (PL) lifetime, resulting from self-trapped exciton emission. The direct band gap characteristic of (MA)4Cu2Br6 was proven by density functional theory calculation, and its band gap was determined by experiments to be ∼3.87 eV. In the temperature range of 98-258 K, the PL intensity increases gradually with an increase in temperature due to the deep trapping out of strong electro-phonon coupling, while the PL decreases when the temperature increases over 258 K due to phonon scattering. It is worth mentioning that this new material has high chemical and light stability, in contrast to the lead perovskite.

In this work, a quasi-one-dimensional ZND model of detonation considering the expansion process perpendicular to the detonation propagation direction is extended to the rotating detonation engine (...

Magnetic particle spectroscopy (MPS), also called magnetization response spectroscopy (MRS), is a versatile measurement tool derived from magnetic particle imaging (MPI). It can be interpreted as a...

Magnetic nanoparticles (MNPs) have been extensively used in drug/gene delivery, hyperthermia therapy, magnetic particle imaging (MPI), magnetic resonance imaging (MRI), magnetic bioassays, and so forth. With proper surface chemical modifications, physicochemically stable and nontoxic MNPs are emerging contrast agents and tracers for in vivo MRI and MPI applications. Herein, we report the high magnetic moment, irregularly shaped γ′-Fe4N nanoparticles for enhanced hyperthermia therapy and T2 contrast agent for MRI application. The static and dynamic magnetic properties of γ′-Fe4N nanoparticles are characterized by a vibrating sample magnetometer (VSM) and a magnetic particle spectroscopy (MPS) system, respectively. Compared to the γ-Fe2O3 nanoparticles, γ′-Fe4N nanoparticles show at least three times higher saturation magnetization, which, as a result, gives rise to the stronger dynamic magnetic responses as proved in the MPS measurement results. In addition, γ′-Fe4N nanoparticles are functionalized with an oleic acid layer by a wet mechanical milling process. The morphologies of as-milled nanoparticles are characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and nanoparticle tracking analyzer (NTA). We report that with proper surface chemical modification and tuning on morphologies, γ′-Fe4N nanoparticles could be used as tiny heating sources for hyperthermia and contrast agents for MRI applications with minimum dose.

This paper adopts the injection model via an array of holes in three-dimensional numerical simulations of a rotating detonation engine with hollow chamber. Premixed stoichiometric hydrogen-air mixture is used. The calculation is based on the compressible Euler equations coupled with a one-step Arrhenius chemistry model. The numerical results show that this injection model can realize stable continuously rotating detonation wave in hollow chamber. In final stable detonation flow-field, besides the multiple detonation waves rotating along outer wall of chamber, there are reverse-rotating waves which propagate in opposite direction of detonation wave. The reverse-rotating wave is much weaker than detonation wave and curved along radial direction of combustion chamber. Pressure gradient contours are used to distinguish these weak reverse-rotating waves. Detonation waves and reverse-rotating waves periodically collide with each other, forming a counter-rotating wave system. The lateral slices of flow-field at various radial positions show that the collision process of counter-rotating waves in flow-field can be divided into two types, shock-to-shock collision and detonation-to-shock collision. In addition, the intensity of detonation waves is the highest on the outer wall and gradually decreases with radius going down. Finally, the detonation wave decouples at a certain radial position and degenerates into shock wave.

In this study, the molecularly imprinted nano-polymer of minocycline was polymerized on the surface of a metal organic framework material to synthesize a novel composite. This composite was used as absorbent to develop a dispersive solid phase microextraction method for extraction of 7 tetracyclines in chicken muscle followed by determination with ultra performance liquid chromatography. The composite achieved high absorption capacities (2200–3000 ng/mg) and high recoveries (> 92%) for the 7 tetracyclines, and could be reused for 8 times. Due to the high enrichment factors (18–37), the limits of detection for the 7 drugs were in the range of 0.2–0.6 ng/g, and the limits of quantification were in the range of 0.5–2.0 ng/g. The recoveries of the 7 drugs from standard-fortified blank chicken muscle sample were in the range of 69.6–94.7%. Therefore, this method could be used as a practical tool for multi-detection of the residues of tetracyclines in meat.

Due to less attention received by rotating detonation ramjet engine (RDRE), the three-dimensional flow-field structures and their influence on stability are less understood than rocket-mode rotating detonation engine (RDE). This paper presents three-dimensional numerical investigations on the RDRE model with a Laval inlet. The computations are based on detailed H2/air chemistry. The simulation shows that, unlike rocket-mode RDEs, an upstream oblique shock wave is induced by detonation. This oblique shock wave is then prevented from propagating upstream further by the normal shock wave in the inlet. In addition, two instabilities in RDREs, namely, backflow and strip-type fresh fuel layer, are analyzed for the first time. Results indicate that the backflow is related to reflected shock waves and the upstream oblique shock wave that induced by detonation. While the strip-type fresh fuel distribution is formed due to the unstable propagation of detonation. Detonation waves interact with fresh fuel layer, transverse waves, and the normal shock waves, making the irregular fresh fuel layer remains in the combustion chamber.

Magnets with a low-temperature coefficient of coercivity (TCC) have various applications in a varying temperature environment. Rare-earth magnets like NdFeB are widely used, but they usually have a large negative TCC. Here, it is first experimentally demonstrated that α″-Fe16N2 foils, as a candidate for rare-earth-free magnets, have an ultralow positive TCC (0.4 Oe/K) from 300 K to 425 K. It is two orders of magnitude smaller than that of the commercial NdFeB magnets in this temperature range. The α″-Fe16N2 foils are made from as-rolled iron foils (25 µm) by a low-temperature nitridation process (

Purpose The purpose of this study is to develop optimal evacuation plan to provide valuable theoretical and practical insight in the fire evacuation work of similar structures, by proposing a systematic simulation-based guided-evacuation agent-based model (GAM) and a three-stage mathematical evacuation model to investigate how to simulate, assess and improve the performance efficiency of the evacuation plan. Design/methodology/approach The authors first present the self-evacuation and guided-evacuation models to determine the optimal evacuation plan in ship chamber. Three key performance indicators are put forward to quantitatively assess the evacuation performance within the two fire scenarios. The evacuation model in tower is built to obtain the dividing points of the three different fire evacuation plans. Findings The study shows that the optimal evacuation plan determined by the GAM considering social relationships effectively relieves the congestion or collision of evacuees and improves the evacuation uniformity. The optimal evacuation plan not only solves the crush caused by congestion or collision of evacuees but also can greatly shorten the evacuation time for passenger ship fire. Originality/value This study establishes the GAM considering the interactive evacuee characteristics and the proportion of evacuees guided by the crew members to make the optimal evacuation plan more time-efficient. The self-evacuation process is simulated to assess the performance of the guided-evacuation strategies, which are used to verify the effectiveness and feasibility of the optimal evacuation plan in this research.

Materials such as L 1 0 Fe-based alloys with perpendicular magnetic anisotropy derived from crystal structure have the potential to deliver higher thermal stability of magnetic memory elements compared to materials whose anisotropy is derived from surfaces and interfaces. A number of processing parameters enable control of the quality and texture of L 1 0 FePd; among them are substrate, deposition temperature, pressure, and seed and buffer layer. The angle of inclination between the substrate and the sputtering target can also impact the texture of L 1 0 crystallization of sputtered FePd and magnetic properties of the derived thin films. This letter examines the difference between FePd layers that have been magnetron sputter deposited on Cr(15 nm)/Pt, Ir, or Ru(4 nm)/FePd (8 nm)/Ru(2 nm)/Ta(3 nm) substrate layers at an oblique angle (30° tilt from the sputtering target) versus normal incidence (target facing the substrate). X-ray diffraction, ferromagnetic resonance spectroscopy, and vibrating sample magnetometry were used to compare the degree of L 1 0 order and static and dynamic properties of films deposited under both conditions. The films grown using the oblique orientation exhibit stronger degree of L 1 0 orientation, larger magnetic anisotropy energy, and lower Gilbert damping, on all three buffer layers.

Multichromophoric systems with efficient photoinduced excited-state processes are important for the conversion of solar energy in artificial photosynthesis. However, a low molecular absorption coefficient of these multichromophoric systems in the near-infrared region limits their power conversion efficiency in organic solar cells. It is critical to design molecules with a broad absorption range in the whole spectral region, to better harvest solar energy, and to reveal their important multiple-step photophysical processes for the design of organic solar cells. Here, we investigate a novel compound having three chromophores, namely two near-by N,N'-bis(1-pentyl)hexyl-3,4,9,10-perylenebiscarboximide (PDI) units linked to a zinc porphyrin core side by side (in the form of PDI-ZnPor-PDI), which absorbs solar energy ranging from the ultraviolet (UV) to near-infrared regions. The photophysical behavior of PDI-ZnPor-PDI in both film and solution forms, has been investigated using steady-state and transient spectroscopy measurements. Charge-transfer species and triplet excited-state species are observed, the excited-state evolutions of which are monitored using molecular vibrations as probes. These observations support the idea that PDI-ZnPor-PDI on photoexcitation generates the radical anion and triplet species of the PDI unit (PDI˙- and 3PDI*). Our results demonstrate the effect of solid film state on the photophysical properties in such multichromophoric system, and are valuable for guiding the design and utilization of novel near-infrared electron donors or acceptors for use in organic solar cells.

Due to the effects of electron correlation and spin–spin coupling, pure transition metal compounds rarely produce luminescence and ferromagnetism. In this work, the Pb-free perovskite materials, C8H20N2MnBr4 and C4H10NMnBr3 with high luminescence yields, were obtained via a simple mechanochemical process. In C8H20N2MnBr4 powders, MnBr42− coordinated with two pyrrolidine molecules to form an independent mononuclear structure in a crystal, with paramagnetic properties and a strong emission band at 520 nm due to the lowest d–d crystal field radiation transition for individual Mn(II) ions. In C4H10NMnBr3 powders, MnX64− octahedra, coordinated with a much smaller amount of pyrrolidine molecules than that in C8H20N2MnBr4, formed edge-sharing linear chains of Mn-ion octahedra with a much smaller Mn–Mn distance, which produced emission bands at 628 nm due to the ferromagnetic coupling of Mn pairs or clusters. Influenced by the modification in the local crystal structure by incorporated pyrrolidine molecules, the microcrystals in these two powders exhibited different phase transition temperatures and varied lifetimes in their photoluminescence besides their emission colors. By controlling the processing time of mechanochemical reactions and pyrrolidine amount, the pyrrolidine insertion into the lattice of this transition metal halide can be adjusted to be completely realized, which provides a very simple way to change the ligand from a halide ion to an organic molecule, which regulates the Mn–Mn distance in the lattice, modifying the electronic correlation and spin coupling, thereby obtaining new manganese perovskite compounds with both strong luminescence and clear ferromagnetic properties.

Nb and its compounds are widely used in quantum computing due to their high superconducting transition temperatures and high critical fields. Devices that combine superconducting performance and spintronic non-volatility could deliver unique functionality. Here we report the study of magnetic tunnel junctions with Nb as the heavy metal layers. An interfacial perpendicular magnetic anisotropy energy density of 1.85 mJ/m2 was obtained in Nb/CoFeB/MgO heterostructures. The tunneling magnetoresistance was evaluated in junctions with different thickness combinations and different annealing conditions. An optimized magnetoresistance of 120% was obtained at room temperature, with a damping parameter of 0.011 determined by ferromagnetic resonance. In addition, spin-transfer torque switching has also been successfully observed in these junctions with a quasistatic switching current density of 7.3 $$\times \;10^{5}$$ × 10 5 A/cm2.

In this work, the structural fluctuations and vibrational energy transfer dynamics in a supramolecular homodimer model, which is composed of 2-(9-anthracene)ureido-6-(1-undecyl)-4[1H]-pyrimidinone (UPAn) with quadruple intermolecular and single intramolecular hydrogen bonds (HBs), have been examined using ultrafast two-dimensional infrared (2D IR) and steady-state IR spectroscopies. A less structurally fluctuating intermolecular HB is found between the pyrimidinone C═O and ureido N-H groups. However, a larger structurally fluctuating intramolecular HB is suggested by the equilibrium and dynamical line-shape measurements of the ureido C═O stretch. Further, dynamical time-dependent 2D IR diagonal and off-diagonal signals show that intra- and intermolecular vibrational energy transfer processes occur on the picosecond timescale, where the latter is more efficient due to intermolecular hydrogen bonding interaction and through-space interaction.

Traditional Von Neumann computing is falling apart in the era of exploding data volumes as the overhead of data transfer becomes forbidding. Instead, it is more energy-efficient to fuse compute capability with memory where the data reside. This is particularly critical to pattern matching, a key computational step in large-scale data analytics, which involves repetitive search over very large databases residing in memory. Emerging spintronic technologies show remarkable versatility for the tight integration of logic and memory. In this article, we introduce SpinPM, a novel high-density, reconfigurable spintronic in-memory pattern matching spin-orbit torque (SOT)-specifically spin Hall effect (SHE)-substrate, and demonstrate the performance benefit SpinPM can achieve over conventional and near-memory processing systems.

ObjectiveThe objective of this study was to measure the effect of micromagnetic stimulation (μMS) on hippocampal neurons, by using single microcoil (μcoil) prototype,MagneticPen(MagPen). MagPen will be used to stimulate the CA3 region magnetically and excitatory post synaptic potential (EPSP) response measurements will be made from the CA1 region. The threshold for micromagnetic neurostimulation as a function of stimulation frequency of the current driving the μcoil will be demonstrated. Finally, the optimal stimulation frequency of the current driving the μcoil to minimize power will be estimated.ApproachA biocompatible, watertight, non-corrosive prototype, MagPen was built, and customized such that it is easy to adjust the orientation of the μcoil and its distance over the hippocampal tissue in anin vitrorecording setting. Finite element modeling (FEM) of the μcoil design was performed to estimate the spatial profiles of the magnetic flux density (in T) and the induced electric fields (in V/m). The induced electric field profiles generated at different values of current applied to the μcoil can elicit a neuron response, which was validated by numerical modeling. The modeling settings for the μcoil were replicated in experiments on rat hippocampal neurons.Main resultsThe preferred orientation of MagPen over the Schaffer Collateral fibers was demonstrated such that they elicit a neuron response. The recorded EPSPs from CA1 region due to μMS at CA3 region were validated by applying tetrodotoxin (TTX). Application of TTX to the hippocampal slice blocked the EPSPs from μMS while after prolonged TTX washout, a partial recovery of the EPSP from μMS was observed. Finally, it was interpreted through numerical analysis that increasing frequency of the current driving the μcoil, led to a decrease in the current amplitude threshold for micromagnetic neurostimulation.SignificanceThis work reports that micromagnetic neurostimulation can be used to evoke population EPSP responses in the CA1 region of the hippocampus. It demonstrates the strengthfrequency curve for μMS and its unique features related to orientation dependence of the μcoils, spatial selectivity and stimulation threshold related to distance dependence. Finally, the challenges related to μMS experiments were studied including ways to overcome them.

Understanding the mechanisms of unidirectional magnetoresistance (UMR) has become an important topic for its potential application of a two-terminal spin–orbit torque device. Field sweep DC measurements have been proposed and adopted to measure the value of UMR instead of second harmonic measurements. In this paper, potential measurement errors in conventional DC measurements are investigated. Oersted field and field-like torque usually do not influence the measurement, but a large field-like torque was found to lead to an anisotropic magnetoresistance difference when the sample is not perfectly aligned with the external field. The existence of ordinary magnetoresistance was also found to contribute to a large background. In this paper, an alternative measurement method for UMR was proposed and demonstrated to address those issues related to previous DC measurements. Our work may broaden the understanding of the error sources of UMR measurements and provide a reliable DC measurement method for the characterization of UMR.

In this study, the dihydropteroate synthase of Staphylococcus aureus was obtained, and its recognition mechanisms for 31 sulfonamide drugs were studied. Results showed that their core structure matched well with the binding pocket of para-aminobenzoic acid, and all the sulfonamide side chains were out of the binding pocket. Hydrogen bonds and hydrophobic interactions were the main intermolecular forces, and the key amino acids were Gly171 and Lys203. The binding sites in sulfonamide molecules were mainly around the para-aminobenzenesulfonamide part. This enzyme was used to develop a fluorescence polarization assay for detection of these drugs in chicken muscles. The change trends of half of inhibition concentrations and cross-reactivities for the 31 drugs were identical with the receptor-ligand affinities. The limits of detection were in the range of 2.0-38.5 ng/g, and one assay could be finished within several minutes. Therefore, this method could be used for multiscreening of sulfonamide residues in meat samples.

Non-fullerene molecules, such as ITIC (3,9-bis(2-methylene-(3-(1,1-dicyanomethylene) indanone)-5,5,11,11-tetrakis(4-hexylphenyl)dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']-dithiophene), are among the most promising non-fullerene acceptors for organic solar cells (OSCs). In this work, using the cyano stretching mode as a vibrational marker, the structural and vibrational energy dynamics of ITIC were examined on an ultrafast time scale with two-dimensional infrared spectroscopy. Two IR-active modes studied here mainly correspond to two anti-symmetric combinations of symmetric and asymmetric stretching vibrations of two C≡N modes originating from two -C(CN)2 chromophores that are located across the ITIC system, which were found to have significantly larger off-diagonal anharmonicity than their corresponding diagonal anharmonicities. This indicates strong anharmonic vibrational coupling between the two modes, which is supported by ab initio anharmonic frequency computations. Transient IR results indicate picosecond intramolecular vibrational energy transfer between the two C≡N modes upon excitation. The structural basis for these vibrational and energetic features is the conjugating molecular frame that is composed of a network of single/double bonds connecting the two -C(CN)2 chromophores and may enable efficient vibration delocalization, in addition to its well-known electron delocalization capability. The importance of the results for the OSC applications is discussed.

In the treatment of neurodegenerative, sensory and cardiovascular diseases, electrical probes and arrays have shown quite a promising success rate. However, despite the outstanding clinical outcomes, their operation is significantly hindered by non-selective control of electric fields. A promising alternative is micromagnetic stimulation (μMS) due to the high permeability of magnetic field through biological tissues. The induced electric field from the time-varying magnetic field generated by magnetic neurostimulators is used to remotely stimulate neighboring neurons. Due to the spatial asymmetry of the induced electric field, high spatial selectivity of neurostimulation has been realized. Herein, some popular choices of magnetic neurostimulators such as microcoils (μcoils) and spintronic nanodevices are reviewed. The neurostimulator features such as power consumption and resolution (aiming at cellular level) are discussed. In addition, the chronic stability and biocompatibility of these implantable neurostimulator are commented in favor of further translation to clinical settings. Furthermore, magnetic nanoparticles (MNPs), as another invaluable neurostimulation material, has emerged in recent years. Thus, in this review we have also included MNPs as a remote neurostimulation solution that overcomes physical limitations of invasive implants. Overall, this review provides peers with the recent development of ultra-low power, cellular-level, spatially selective magnetic neurostimulators of dimensions within micro- to nano-range for treating chronic neurological disorders. At the end of this review, some potential applications of next generation neuro-devices have also been discussed.

In this study, the recognition mechanisms and affinities of a natural dihydropteroate synthase for 44 sulfonamides were studied respectively. Then the key contact amino acid Ser222 was mutated to Arg222 by using site-directed mutagenesis method to produce a mutant. Results showed that the binding energies and affinities for the 44 drugs were generally improved. Then this mutant was used as recognition reagent to develop a direct competitive fluorescence method on 96-well microplate for determination of the 44 drugs in milk. Due to the used signal amplified fluorescent tracer, the limits of detection for the 44 drugs were in the range of 0.025-0.65 ng/mL, and the sensitivities were improved for about 6-86 folds in comparison with the conventional fluorescent tracer. After comprehensive comparison, the present method showed generally better performances than the previously reported immunoassays for sulfonamides. Therefore, this method could be used as an efficient tool for the routine screening of sulfonamides residues in large number of food samples.

The distribution, dynamics and function of RNA structures in human development is under- explored. Here, we systematically assayed RNA structural dynamics and its relationship with gene expression, translation and decay during human neurogenesis. We observed that the human ESC transcriptome is globally more structurally accessible than that of differentiated cells; and undergo extensive RNA structure changes, particularly in the 3’UTR. Additionally, RNA structure changes during differentiation is associated with translation and decay. We also identified stage-specific regulation as RBP and miRNA binding, as well as splicing is associated with structure changes during early and late differentiation, respectively. Further, RBPs serve as a major factor in structure remodelling and co-regulates additional RBPs and miRNAs through structure. We demonstrated an example of this by showing that PUM2-induced structure changes on LIN28A enable miR-30 binding. This study deepens our understanding of the wide-spread and complex role of RNA-based gene regulation during human development.

A lead-free compound, (TBAC)SnCl3 (TBAC = tetrabutylammonium chloride), with high anti-water stability was reported, which can be stable in water for 24 hours. Upon photoexcitation, this compound exhibits a green photoluminescence (PL) centered at 523 nm with a larger Stokes shift of 260 nm at room temperature (RT), stemming from self-trapped exciton (STE) emission.

Background: Multiple primary colorectal cancers (MPCC) includes synchronous colorectal carcinoma (SC) and metachronous colorectal carcinoma (MC), which are defined as multiple malignant colorectal tumors that occur simultaneously or heterochrony. Comparing to isolate colorectal cancer, the incidence of SC is still rare. At present, there are few literatures describing the cases and reviews of SC. Case presentation: Here, we present three cases of SC. The first patient was admitted to our hospital because of a 5-month history of abdominal pain associated with difficult defecation. PET-CT revealed that a mass lesion of the splenic flexure of colon and another mass in sigmoid. Colonoscopy demonstrated double lesions in splenic flexure and sigmoid. Then we performed traditional open subtotal colon resection. Postoperative pathology confirmed that there are malignant characteristics of the double lesions. Another patient was suffered from with dizziness and fatigue for more than 2 years. Abdominal contrast-enhanced CT shows irregular thickening of the ascending colon wall and colonoscopy reveals that there is a tumor in rectum and many polyps in sigmoid. Then we underwent radical resection of rectal cancer and right colon cancer in a laparoscopic operation. Postoperative pathology confirmed moderately differentiated adenocarcinoma of the rectum and ascending colon. The third patient had hematochezia for 1 year. Both rectal magnetic resonance imaging (MRI) and colonoscopy showed that there are two lesions in the rectum, and conventional laparoscopic APR surgery was performed. Postoperative pathology confirmed malignant tumors in the rectum respectively. The mini review summed up the main points about prevalence, clinical manifestation, diagnosis, pathological, treatment and molecular mechanism features of SC based on current literature, which probably has significant distinctions with solitary tumors. Conclusions: Compared with isolated colorectal cancer, SC usually has a low stage，grade and incidence, but the age, sex and location is still a controversial issue. Colonoscopy and surgery are considered to be the best diagnosis and treatment method for SC. At present, serrated adenoma, hyperplastic polyp, ulcerative colitis and Crohn's disease are considered to be closely related to SC. MSI and gene mutation are two molecular mechanisms that lead to SC.

In this study, nitrobenzene was used as dummy template to synthesize a type of specific molecularly imprinted microspheres for chloramphenicol, and 4-nitroaniline was coupled with three fluorophores to synthesize three fluorescent tracers. Then a competitive fluorescence method was developed on a conventional microplate for detection of chloramphenicol in chicken and pork samples. This method contained only one sample-loading step, so one assay was finished within 30 min. The IC50 was 1.8 ng/ml, and the limit of detection was 0.06 ng/g. The recoveries from chloramphenicol-fortified blank meat samples were in the range 67.5-96.2%. Furthermore, this method could be recycled three times. The detection results for some real meat samples were identical to that of a LC-MS/MS method. Therefore, this method could be used as a practical tool for routine screening for the residue of chloramphenicol in large number of meat samples.

A new pair of enantiomeric isoprenylated chromone derivatives, (±)-pestaloficiol X [(±)

Embedded/edge computing comes with a very stringent hardware resource (area) budget and a need for extreme energy efficiency. This motivates repurposing, i.e., reconfiguring hardware resources on demand, where the overhead of reconfiguration itself is subject to the very same tight budgets in area and energy efficiency. Numerous applications running on resource constrained environments such as wearable devices and Internet-of-Things incorporate CAM (Content Addressable Memory) as a key computational building block. In this paper we present CAMeleon -- a novel energy-efficient compute substrate which can seamlessly be reconfigured to perform CAM operations in addition to logic and memory functions. CAMeleon has a similar level of latency to conventional CAM designs based on SRAM and emerging memory technologies (such as STT-MTJ, ReRAM and PCM), however, performs CAM operations more energy-efficiently, consumes less area, and can support traditional logic and memory functions beyond CAM operations on demand thanks to its reconfigurability.

Background & aim Active abdominal compression-decompression cardiopulmonary resuscitation (AACD-CPR), which applies to cardiac arrests with contraindication of standard chest compressions (SCC) CPR, has been utilized in cardiac arrest. However, the efficacy and safety of AACD-CPR still remained controversy. This analysis was designed to comprehensively compare AACD versus SCC-CPR in patients with cardiac arrest. Methods We searched the Cochrane Library, PubMed, EMBASE, Web of Science and CNKI up to April 22, 2019. Mean difference (MD) and risk ratio (RR) with its 95% confidence intervals (CIs) were estimated to compare outcomes of the groups. Our primary outcomes were restoration of spontaneous circulation (ROSC) and short-term survival. Two reviewers assessed trial quality and extracted data independently. All statistical analyses were performed using standard statistical procedures provided in Review Manager 5.2 and Stata 12.0. Results A total of seventeen studies (N = 1647 patients) were identified for the present analysis. Compared with standard CPR, AACD-CPR was superior in restoration of spontaneous circulation (ROSC) and short-term survival, with pooled RRs of 1.38 (95% CI 1.23–1.55; P Conclusions Generally, in this combined analysis we found a statistically significant improvement in survival and ROSC with the use of AACD-CPR as compared with the use of standard CPR. There was also significant improvement in incidence of fracture, long-term survival, PETCO2 and CPP with AACD-CPR in comparison with standard CPR; results were not statistically different between the groups regarding to vomiting rate and adverse events. The standardized, diversified and individualized methods of clinical operation of AACD-CPR need exploration and expectingly serve as a guideline for clinical application of AACD-CPR in the future.

Artificial modulation of a neuronal subset through ion channels activation can initiate firing patterns of an entire neural circuit in vivo. As nanovalves in the cell membrane, voltage-gated ion ch...

Semiconductor nanocrystals are mostly prepared by colloid chemistry with organic surfactant molecules, and their surface polarization effect on the carrier relaxations are critical to their optoele...

The objective of this study is to report a molecularly imprinted polymer-based chemiluminescence method for determination of Sudan dyes. A dummy-template molecularly imprinted polymer capable of recognizing seven Sudan dyes was first synthesized and its recognition mechanism was studied by using computation simulation method. The polymer was coated in the wells of conventional microplate to prepare a chemiluminescence sensor and the assay process consisted of only one sample-loading step prior to signal acquisition. The optimized sensor was used to determine the seven dyes in egg yolk and the results were confirmed with a high performance liquid chromatography. Results showed that this sensor achieved ultrahigh sensitivity (1.0–5.0 pg/mL), rapid assay process (10 min) and satisfactory recovery (70.5%–92.2%). Furthermore, the sensor could be reused for 5 times. Therefore, this sensor could be used as a useful tool for screening the residues of Sudan dyes in egg.

The Computational Random Access Memory (CRAM) is a platform that makes a small modification to a standard spintronics-based memory array to organically enable logic operations within the array. CRAM provides a true in-memory computational platform that can perform computations within the memory array, as against other methods that send computational tasks to a separate processor module or a near-memory module at the periphery of the memory array. This paper describes how the CRAM structure can be built and utilized, accounting for considerations at the device, gate, and functional levels. Techniques for constructing fundamental gates are first overviewed, accounting for electrical and noise margin considerations. Next, these logic operations are composed to schedule operations in the array that implement basic arithmetic operations such as addition and multiplication. These methods are then demonstrated on 2D convolution with multibit data, and a binary neural inference engine. The performance of the CRAM is analyzed on near-term and longer-term spintronic device technologies. Significant improvements in energy and execution time for the CRAM-based implementation over a near-memory processing system are demonstrated, and can be attributed to the ability of CRAM to overcome the memory access bottleneck, and to provide high levels of parallelism to the computation.

We investigated spin-to-charge conversion in sputtered Bi43Se57/Co20Fe60B20 heterostructures with in-plane magnetization at room temperature. High spin-to-charge conversion voltage signals have been observed at room temperature. The transmission electron microscope images show that the sputtered bismuth selenide thin films are nanogranular in structure. The spin-pumping voltage decreases with an increase in the size of the grains. The inverse Edelstein effect length (λIEE) is estimated to be as large as 0.32 nm. The large λIEE is due to the spin-momentum locking and is further enhanced by quantum confinement in the nanosized grains of the sputtered bismuth selenide films. We also investigated the effect on spin-pumping voltage due to the insertion of layers of MgO and Ag. The MgO insertion layer has almost completely suppressed the spin-pumping voltage, whereas the Ag insertion layer has enhanced the λIEE by 43%.

It has been a long-lasting debate whether indigo undergoes excited-state proton transfer and how this contributes to its photostability. A prevailing point of view is that a sub-picosecond excited-state intramolecular single proton transfer occurs; however, it has been studied mostly under dilute solution conditions. In this work, excited-state structural dynamics of indigo oligomers formed at millimolar concentration in dimethyl sulfoxide is investigated using femtosecond visible pump spectroscopy, infrared and visible probe spectroscopies, and steady-state infrared and fluorescence spectroscopies. Experimental evidence indicates the presence of transient intermolecular electronic excited-state proton transfer, which is supported by quantum-chemistry computations. The formed enol species disappears with a time constant of 200-300 fs, followed by a relatively slow nonradiative relaxation to the electronic ground state. Our results reveal new photochemistry of indigo particularly in its oligomeric state.

In this study, a novel composite was synthesized by polymerizing the dummy-template molecularly imprinted microspheres on the surface of magnetic graphene. This composite was used as recognition reagent and energy acceptor to develop a platform for determination of chloramphenicol according to the principle of chemiluminescence resonance energy transfer. The light signal was induced with luminol H2O2 4-(imidazole-1-yl)phenol system, and the chemiluminescence intensity was positively correlated with the analyte concentration. The limit of detection for chloramphenicol in meat sample was 2.0 pg/g, and the recoveries from the standard fortified blank meat sample were in the range of 69.5%–97.3%. Furthermore, one single assay could be finished within 10 min, and the magnetic composite could be reused for at least thirty times. Therefore, this platform could be used as a rapid, simple, sensitive, accurate and recyclable tool for screening the residue of chloramphenicol in meat.

Magnetic nanoparticles (MNPs) have been extensively used as contrasts and tracers for bioimaging, heating sources for tumor therapy, carriers for controlled drug delivery, and labels for magnetic immunoassays. Here, we describe a MNP relaxation dynamics-based magnetic particle spectroscopy (MPS) method for the quantitative detection of molecular biomarkers. In MPS measurements, the harmonics of oscillating MNPs are recorded and used as a metric for the freedom of rotational motion, which indicates the bound states of the MNPs. These harmonics can be collected from microgram quantities of iron oxide nanoparticles within 10 seconds. Using a streptavidin-biotin binding system, we demonstrate the feasibility of using MPS to sense these molecular interactions, showing this method is able to achieve rapid, wash-free bioassays, and is suitable for future point-of-care (POC), sensitive, and versatile diagnosis., 24 pages, 8 figures, 2 schemes, 1 table

In this study, a homogeneous competitive immunoassay based on graphene and chemiluminescence resonance energy transfer was first reported to detect small molecule substance. A generic monoclonal antibody of phenothiazine drugs was coupled to graphene as the recognition element and energy acceptor. The composite, the HRP-labeled hapten and the analyte solution were added into the microplate wells to perform homogeneous competition. Then luminol-H2O2-4-(imidazol-1-yl)phenol system was added to initiate light emission, and the light signal was positive correlation with the analyte concentration. After optimization of several parameters, the method was used to determine the residues of 4 phenothiazines in pig urine. Results showed that one assay was finished within 10 min, and the limits of detection for the 4 drugs were in the range of 2.0–5.0 pg/mL. Their recoveries from the standards fortified blank urine sample were in the range of 81.5%–96.8%. Therefore, this method could be used as a simple, rapid, and sensitive tool for routine screening the residues of phenothiazines in pig urine.

BACKGROUND Hepatocellular carcinoma (HCC) is the third leading cause of death from malignant tumors worldwide. More than 50% of HCC cases occur in China. The prognosis remains poor and overall efficacy is still unsatisfactory. Chemotherapy resistance is the most important reason for the poor outcome. Much progress has been made in the study of chemotherapy resistance of HCC; however, the specific mechanisms of progression of HCC have still only been partially established. Therefore, the mechanism of chemotherapy resistance in HCC requires more research. AIM To investigate the effect of miR-34a expression on the growth inhibition of HepG2 cells by doxorubicin. METHODS A recombinant lentiviral vector containing miR-34a was constructed and transfected into HepG2 cells. The expression of miR-34a was detected by reverse transcription-polymerase chain reaction (commonly known as RT-PCR) before and after transfection. Cells were exposed to 2 μM doxorubicin or phosphate-buffered saline before and after transfection. Cell viability in each group was detected by MTT assay, and cell cycle and apoptosis were detected by flow cytometry. Changes in expression levels of phospho (p)-p53, sirtuin (SIRT) 1, cyclin D1, cyclin-dependent kinase (CDK) 4, CDK6, BCL-2, multidrug resistance protein (MDR) 1/P glycoprotein (P-gp), and AXL were detected by Western blotting. RESULTS Recombinant lentiviral vector LV-hsa-mir-34a was successfully constructed by restriction endonuclease digestion and sequencing. RT-PCR showed that expression of miR-34a in HepG2 cells was significantly upregulated after transfection (P < 0.01). MTT assay showed that growth of HepG2 cells was inhibited after upregulation of miR-34a, and viability was significantly decreased after combined treatment with doxorubicin (P < 0.01). Flow cytometry showed that the number of HepG2 cells in G1 phase increased, and G1 phase arrest was more obvious after intervention with doxorubicin (P < 0.01). The apoptosis rate of HepG2 cells was increased after upregulation of miR-34a, and became more obvious after intervention with doxorubicin (P < 0.01). Western blotting showed that upregulation of miR-34a combined with treatment with doxorubicin caused significant changes in the expression levels of p-p53, SIRT1, cyclin D1, CDK4, CDK6, BCL-2, MDR1/P-gp and AXL proteins (P < 0.01). CONCLUSION MiR-34a may enhance the inhibitory effect of doxorubicin by downregulating MDR1/P-gp and AXL, which may be related to p53 expression.