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The separation of chiral amino acids (AAs) and their derivatives has always been a research difficulty in the field of biochemistry due to the high similarity of enantiomeric structures. In this work, a simple and quick method using natamycin (Nat) as chiral selector has been developed to simultaneously separate chiral AAs and their derivatives of carbobenzoxy/benzyl-AAs (Cbz/Bzl-AAs) by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS). Specifically, 12 groups of the Cbz-AAs and Bzl-AAs can get baseline mobility separation by simple mixing with Nat to form binary diastereomeric complex ions [Nat+(Cbz-D/L-AA)+H]

Intravenous immunoglobulin (IVIG) is an established treatment for numerous autoimmune conditions. Although Fc fragments derived from IVIG have shown efficacy in controlling immune thrombocytopenia in children, the mechanisms of action are unclear and controversial. The aim of this study was to dissect IVIG effector mechanisms using further adapted Fc fragments on demyelination in an ex vivo model of the central nervous system–immune interface. Using organotypic cerebellar slice cultures (OSCs) from transgenic mice, we induced extensive immune‐mediated demyelination and oligodendrocyte loss with an antibody specific for myelin oligodendrocyte glycoprotein (MOG) and complement. Protective effects of adapted Fc fragments were assessed by live imaging of green fluorescent protein expression, immunohistochemistry and confocal microscopy. Cysteine‐ and glycan‐adapted Fc fragments protected OSC from demyelination in a dose‐dependent manner where equimolar concentrations of either IVIG or control Fc were ineffective. The protective effects of the adapted Fc fragments are partly attributed to interference with complement‐mediated oligodendroglia damage. Transcriptome analysis ruled out signatures associated with inflammatory or innate immune responses. Taken together, our findings show that recombinant biomimetics can be made that are at least two hundred‐fold more effective than IVIG in controlling demyelination by anti‐MOG antibodies., Adapted Fc fragments protect against antibody‐mediated demyelination in a dose‐dependent manner where equimolar concentrations of either IVIG or control Fc were ineffective. The protective effects of the adapted Fc fragments are partly attributed to interference with complement‐mediated oligodendroglia damage.

Hard and brittle materials such as monocrystalline silicon still occupy an important position in the semiconductor industry, but hard and brittle materials are difficult to process because of their physical properties. Fixed-diamond abrasive wire-saw cutting is the most widely used method for slicing hard and brittle materials. The diamond abrasive particles on the wire saw wear to a certain extent, which affects the cutting force and wafer surface quality in the cutting process. In this experiment, keeping all the given parameters unchanged, a square silicon ingot is cut repeatedly with a consolidated diamond abrasive wire saw until the wire saw breaks. The experimental results show that the cutting force decreases with the increase in cutting times in the stable grinding stage. The wear of abrasive particles starts at the edges and corners, and the macro failure mode of the wire saw is fatigue fracture. The fluctuation of the wafer surface profile gradually decreases. The surface roughness of wafer is steady during the wear steady stage, and the large damage pits on the wafer surface are reduced in the whole process of cutting.

In order to analyze the inner flow in a multi-stage double-suction centrifugal pump, which is regarded as a common way of knowing the current characteristics of the pump and as the basis of optimization for better performance, a numerical simulation considering the velocity field distribution characteristics and pressure fluctuation propagation law using the detached eddy simulation method was conducted. Additionally, the principle of entropy generation was put to use to quantify and compare the energy loss of different components. The results reveal that the existence of unstable flow structures in the first-stage impeller and a large number of vortical structures in the back-channel result in reduced operational efficiency of the pump. Furthermore, the pressure fluctuation intensity reaches its maximum with 0.15 at the blade trailing edge, which propagates to the tongue region of the forward flow channel and the double-volute under the low rates condition. Additionally, the main frequency of the monitoring points in the inter-stage flow channel and volute is basically located at a frequency of 198.667 Hz, which is twice the blade frequency. Consequently, the wall entropy production accounting for nearly 25% cannot be ignored and that the loss mainly occurs in the double-volute and the inter-stage flow channel due to the occurrence of irregular flow in the above components with more than 50%. The outcomes of this research present a valuable point of reference for the optimization of structural design in multistage turbomachines with various applications.

In this study, an improved delayed detached-eddy simulation method has been used to investigate the aerodynamic behavior of the CRH2 high-speed trains (HST) with different first and last bogie positions. The results of the numerical simulations have been validated against experimental data obtained from a previous wind tunnel test, a full-scale field test and a reduced-scale moving model test. The results of the flow prediction are used to explore the effects of the bogie positions on the slipstream, wake flow, underbody flow and aerodynamic drag. Compared with the original HST model, the downstream movement of the first bogie, has a great effect on decreasing the slipstream velocity and pressure fluctuation aside the HST, especially around the lower part of the HST. Furthermore, the size of the longitudinal vortex structure and slipstream velocity in the near wake region also decrease significantly by moving the last bogie upstream. Additionally, the movement of the first and last bogies toward the HST center, effectively decreases the drag values of the head and tail car, while a lower effect is observed on the intermediate cars.

An interturn short-circuit fault in the stator winding of an electric machine, denoted as turn fault, has been recognized as one of the most severe faults in permanent magnet machines, which require a swift and reliable detection, in order to implement appropriate mitigations. The asymmetry brought by a turn fault is widely used for fault detection. However, similar features also emerge in a less severe high-resistance connection (HRC) fault, which may lead to an incorrect fault identification. In this article, a more exclusive turn fault detection method with the ability to differentiate from the HRC fault is proposed. It injects high-frequency square-wave voltage signals and makes use of the difference in the high-frequency impedance under the two fault conditions. The sensitivity to the HRC fault is largely reduced. The proposed turn fault indicator is independent of the operating conditions and robust with respect to state transients. This method is validated in a fault-tolerant permanent magnet assisted synchronous reluctance machine drive.

Interturn short-circuit fault, also known as turn fault, is a common fault in electric machines, which can cause severe damages if no prompt detection and mitigation are conducted. This article proposes a turn fault detection method for permanent magnet machines based on current residual. After the impact of the turn fault is first analyzed on a simplified mathematical machine model to assess the fault signature, a finite-element model is developed to obtain healthy machine behavior. The residual between the measured and estimated currents by the model with the same applied voltages contains mainly the fault features. The quality of the fault detection can be improved because the fault signatures are enhanced, and the impact of the current controller bandwidth on fault signature is minimized. The dc components in the negative-sequence current residuals are extracted through angular integration, and their magnitude is defined as the fault indicator. The robustness of the fault detection against transient states is achieved. The effectiveness of the proposed method is validated on a triple redundant fault-tolerant permanent-magnet-assisted synchronous reluctance machine.

Leaf area index (LAI) is an important indicator of vegetation growth and health monitoring. The free access of Sentinel-2 optical satellite data from European Space Agency (ESA) since June 2015 made it possible to determine dynamic monitoring of LAI in a large area and a short re-entry period, owing to its high spatial resolution (up to 10 m) and unique band combination. These features of Sentinel-2 may bring great application potential in urban forestry management and ecological environment monitoring. In case of Zhongshan city in Guangdong Province, based on Sentinels Application Platform (SNAP) software and two scenes of Sentinel-2 data, LAI of the whole city, as well as specific areas, were retrieved and analyzed. The retrieval result was consistent with the ecological spatial pattern and the vegetation protection status in Zhongshan city, also highly consistent with the field LAI measurement in the forest in a reservoir. The result indicates that this method has good applicability and accuracy in urban LAI inversion.

In this paper, a reduced order thermal observer with disturbance estimation is applied for temperature monitoring in a power electronics module. Although accurate thermal models of power electronics assemblies are widely available, based e.g. on computational fluid dynamics (CFD) solvers, their\ud computational complexity hinders the application in real-time temperature monitoring applications. This paper proposes a reduced order state space observer to provide a real-time estimation of temperature in power electronics modules. The observer is coupled with a disturbance estimator, to minimize the error caused by uncertainties in the model and unknown operating conditions.

Unconventional protein secretion (UPS) pathways are conserved across species. However, the underlying mechanisms that regulate Golgi-bypassing UPS of integral proteins remain elusive. In this study, we show that RAB-8 and SMGL-1/NBAS are required for the UPS of integral proteins in C. elegans intestine. SMGL-1 resides in the ER-Golgi intermediate compartment and adjacent RAB-8-positive structures, and NRZ complex component CZW-1/ZW10 is required for this residency. Notably, SMGL-1 acts as a guanine nucleotide exchange factor for RAB-8, ensuring UPS of integral proteins by driving the activation of RAB-8. Furthermore, we show that Pseudomonas aeruginosa infection elevated the expression of SMGL-1 and RAB-8. Loss of SMGL-1 or RAB-8 compromised resistance to environmental colchicine, arsenite, and pathogenic bacteria. These results suggest that the SMGL-1/RAB-8-mediated UPS could integrate environmental signals to serve as a host defense response. Together, by establishing the C. elegans intestine as a multicellular model, our findings provide insights into RAB-8-dependent Golgi-bypassing UPS, especially in the context of epithelia in vivo.

This paper presents a novel ring-shaped hybrid fractal antenna for detection of partial discharge (PD) in inverter-fed machines. Partial discharge is known as a source of degradation and lifetime reduction in the machines winding insulation. PD activity is becoming a major concern in high performance drives, especially due to the increased use of repetitive impulse voltage with short rise-time (high dv/dt) from PWM-controlled inverters. The proposed hybrid fractal antenna is designed and experimentally demonstrated to show a high sensitivity in the ultra-high frequency (UHF) bandwidth of interest for PD detection as well as an ability to discriminate PD signals from other sources of high frequency disturbances. Additionally, the proposed PD sensing solution features a unique ring-shape geometry which facilitates its physical integration to a live machine, making it suitable as a non-invasive solution for online condition monitoring and PD detection of any inverter-fed electrical machine.

Water hammers seriously endanger the stability and safety of pipeline transportation systems, and its protection mechanism has been a hotspot for research. In order to study the change of water hammer pressure caused by the ball valve under different closing laws, the computational fluid dynamics method was used to perform transient numerical simulation of the ball valve under different closing times and closing laws. The results show that the faster the valve closing speed in the early stage, the greater the water hammer pressure. The vortex core motion and pressure vibration were affected by the closing law. Extending the valve closing time can effectively reduce the maximum water hammer pressure. These findings could provide reference for water hammer protection during the closing process of the pipeline system with the ball valve.

The folding of interphase chromatin into highly compact mitotic chromosomes is one of the most recognizable changes during the cell cycle. However, the structural organization underlying this drastic compaction remains elusive. Here, we combine several super resolution methods, including structured illumination microscopy (SIM), binding-activated localization microscopy (BALM), and atomic force microscopy (AFM), to examine the structural details of the DNA within the mitotic chromosome, both in the native state and after up to 30-fold extension using single-molecule micromanipulation. Images of native chromosomes reveal widespread ∼125 nm compact granules (CGs) throughout the metaphase chromosome. However, at maximal extensions, we find exclusively ∼90 nm domains (mitotic nanodomains, MNDs) that are unexpectedly resistant to extensive forces of tens of nanonewtons. The DNA content of the MNDs is estimated to be predominantly ∼80 kb, which is comparable to the size of the inner loops predicted by a recent nested loop model of the mitotic chromosome. With this DNA content, the total volume expected of the human genome assuming closely packed MNDs is nearly identical to what is observed. Thus, altogether, these results suggest that these mechanically stable MNDs, and their higher-order assembly into CGs, are the dominant higher-level structures that underlie the compaction of chromatin from interphase to metaphase.

Power sector carbon emissions (PSCEs) have received an increasing attention due to their huge contribution to global greenhouse gas emissions. Herein, the research characteristics and trends of PSCEs are investigated based on bibliometric analysis. The basic growth trends, contributions of the most productive countries/territories, institutions, authors, journals, and subject categories are analyzed systematically. In addition, the major research fields and research trends are investigated by the keywords co-occurrence analysis and topic evolution. The result indicates that PSCEs research has developed rapidly in the past 20 years, and the proportion of research funding has increased from 0 at the beginning to 73% in the last 5 years. Especially, the number of scientific publications has shown an explosive growth after the signing of the Paris Agreement in 2016. The People's Republic of China (PR China), the USA, and England are the three most dynamic countries in the field of PSCEs research, with 64.8% of the total number of published papers. The most productive institutions are also from these countries. Based on keywords co-occurrence analysis, it is concluded that driving factors, prediction, impacts, and countermeasures of carbon emission are three major research fields. The result of thematic evolution indicates that the topics on energy transition, life cycle assessment, marginal abatement cost and energy policy have been the research hotspots in recent years. This study presents an worldwide overview of PSCEs research, thus helping the stakeholders to quickly grasp the research trends and conduct future work.

In inverted perovskite solar cells (PSCs), the fullerene derivative [6,6]-phenyl-C

A nanomesh organic electrochemical transistor (NMOECT) is proposed. The NMOECT is a porous nanomesh structure, which enables the device to be comfortably laminated on human skin and simultaneously ...

The strength and toughness are two trade-off properties of a material, yet Nature can achieve strong and tough materials by introducing sacrificial bonds into a system. Here, we present a four-comp...

In this article, a multiparameter model order reduction (MOR) is applied to the thermal modeling and simulation of power electronics modules and air cooling systems. Although widely employed, simulation tools based on finite elements (FE) or finite difference methods result in computationally expensive models that hamper the analysis in studies where one or more parameters are changed. MOR techniques can be applied to reduce the computational complexity. However, standard reduction techniques cannot easily consider parameters variability and need to be reapplied for each parameter value. This article proposes a multiparameter order reduction technique that can significantly improve the thermal simulation efficiency without having a significant impact on the prediction accuracy. The method is applied to multichip SiC power module mounted on a forced air-cooled finned heatsink with variable air flow.

Background Natural compounds extracted from plants have been reported to have antitumor activity. A fungal metabolite from Phomopsis, identified as epoxycytochalasin H and isolated from the flowering plant Polygonatum sibiricum, was found to have significant antitumor activity. In this study, we report the antitumor effects and mechanism of action of epoxycytochalasin H in the ovarian cancer cell line A2780. Our data suggest that epoxycytochalasin H markedly reduces cell proliferation and induces apoptosis in ovarian cancer cells. Materials and methods The viability, apoptosis and colony formation of A2780 cells, treated with epoxycytochalasin H, were detected by MTT assay, nuclear staining, flow cytometry, and clone formation assay. MitoROS and mitochondrial membrane potentials were detected by MitoSOX staining and flow cytometry. The expression of proteins associated with apoptosis, autophagy, and endoplasmic reticulum stress, in A2780 cells treated with epoxycytochalasin H, was detected by Western blot. Effects of mitophagy were detected in Parkin-overexpressing 293T cells. Results Our data suggested that epoxycytochalasin H could strongly reduce cell proliferation and induce apoptosis in ovarian cancer cell line A2780. Epoxycytochalasin H induced apoptosis through mitochondrial injury, mitophagy, and endoplasmic reticulum stress. Specifically, epoxycytochalasin H increased ROS level in cells, and in mitochondria, it decreased mitochondrial membrane potential, caused mitochondrial injury, activated macroautophagy and mitophagy, and subsequently induced apoptosis via the mitochondrial pathway. Additionally, it was discovered that epoxycytochalasin H could induce apoptosis more significantly in 293T cells overexpressing Parkin than in the parental cells. Thus, the mitophagy activated by epoxycytochalasin H could promote apoptosis. In addition, epoxycytochalasin H mediated endoplasmic reticulum stress-related apoptosis. Conclusion Epoxycytochalasin H could promote apoptosis of human ovarian cancer A2780 cells by activating mitochondrial and endoplasmic reticulum stress-related apoptotic pathways.

A five-phase fault-tolerant permanent-magnet (FTPM) motor can offer high torque density, low torque ripple, and good fault-tolerance. To improve operational performance under open-circuit fault condition, this article proposes a novel direct torque control (DTC) based on virtual stator flux strategy for an FTPM motor drive. The novelty of the proposed strategy is the development of virtual stator flux, which is used to achieve circular trajectories of current and rotating magneto-motive force vectors, and to derive feedforward voltage. Additionally, optimal fault-tolerant current references get derived based on maximum torque criterion, and then combined with reduced-order orthogonal decomposition matrices deduced from them, the feedforward voltage is used to eliminate asymmetrical motor behavior under the fault condition. Hence, the DTC becomes applicable to the FTPM motor drive under open-circuit fault condition. This control strategy not only enhances the torque performance with smooth torque and high dynamic response but also allows minimal reconfiguration of the control structure from healthy operation to fault-tolerant operation. The simulation and experimental results are given to verify the feasibility of the proposed strategy.

A turn-to-turn short-circuit fault usually causes excessive fault current because of very low impedance associated with a few fault turns. It should be dealt with promptly to avoid further damages to the machine, especially for a permanent magnet (PM) machine. In order to limit the turn fault current, a novel turn fault mitigation strategy based on current injection technique for a triple redundant 3 × 3-phase PM synchronous reluctance machine (PMA SynRM) is investigated in this paper. First, the flux linkage of the fault phase where the fault turns are located is estimated considering the influence of PM and currents in the healthy and fault three-phase sets. This flux linkage, including that of the fault turns, is subsequently reduced by injecting specific currents to the fault three-phase set, leading to much smaller fault current. The proposed current injection method does not affect the operation of the healthy three-phase sets that continue to produce torque. The effectiveness of the proposed method is validated by extensive finite-element (FE) simulation and experimental tests on a prototype 3 × 3-phase fault-tolerant PMA SynRM drive.

Ethylene-triggered flowering is a common phenomenon in plants of the family Bromeliaceae, but its molecular mechanism remains unclear. As a classical group of small RNAs, microRNAs play an essential role in the regulation of flowering. In this study, we found that various miRNAs participate in the ethylene-triggered flowering process in Aechmea fasciata via small RNA sequencing using juvenile and adult plants treated with ethylene for 24 hours. Finally, 63 known miRNAs, 52 novel miRNAs and 1721 target genes were identified or predicted. Expression changes of specific miRNAs were validated by qRT-PCR and northern blotting. Some predicted targets, including SPL, GAMYB and ARF, were verified in RLM-RACE experiments. Gene Ontology (GO) and KEGG analysis showed that numerous developmental and RNA-related processes were enriched. Integrated analysis of the transcriptomic data with small RNA sequencing revealed that numerous miRNAs and targets involved in ethylene-triggered flowering in A. fasciata. Our study is helpful for illuminating the molecular basis of the ethylene-triggered flowering phenomenon in Bromeliaceae.

This paper reviews the current status of investigation on snow accumulation on the bogies of high-speed trains (HSTs) running in snowy region. First, the background of the snow issue occurring to the HST and the contra-measures for the snow issue proposed in the past decades are provided by reviewing previous studies. Next, the methodology for investigating the snow issue developed by High-Speed Train Research Center of Central South University is introduced, including the numerical simulation research platform and the experimental devices for two-phase flow wind tunnel tests. Then, effective anti-snow flow control schemes for guiding the underbody airflow and their impact on the motion and accretion of snow in the installation region of the bogies are presented. Finally, the remaining investigating challenge for the snow issue of HST and the future research with respect to the challenge are provided from an engineering application viewpoint.

This paper uses an improved delayed detached eddy simulation method to investigate the unsteady flow features of the high-speed trains with various cavity lengths at Re = 1.85×106. The improved delayed detached eddy simulation results are validated against the experimental data obtained during previous wind tunnel tests. The effects of cavity length on the resistance force, flow structures beneath the high-speed train and in the wake are analyzed. The results show that a longer cavity significantly increases the streamwise velocity level near the rear plates and forms a stronger impinging flow on the rear plates, and thus contributes to a higher value of resistance. Furthermore, a longer cavity decreases the pressure coefficients around the near wake region from the top of the ballast to the tail nose in the vertical direction and thereby increases the pressure drag of the high-speed train. Additionally, a longer bogie cavity is found to increase the longitudinal vortex scales in the near wake region. All these changes on the flow field bring to 5.8% and 11.5% drag increase when the bogie cavities are elongated by 20% and 40%, respectively, of the wheelbase.

A direct cooling design using hollow conductors with the coolant flowing inside can significantly improve the heat dissipation in an electrical machine. To predict the thermal performances of an electrical machine with such cooling configuration, this paper proposes a computationally efficient thermal model of hollow conductors with direct cooling features. The hollow conductor is modeled using four equivalent solid cuboidal elements with a three-dimensional thermal network and internal heat generation. The heat transfer coefficient between the coolant and conductors is determined by an empirical model considering fluid dynamics behaviors. Axial discretization is performed to take into account the nonuniform temperature distribution along the axial direction. Experimental validation is performed with a U-shaped hollow conductor test rig. Compared to computational fluid dynamics analysis, the proposed thermal model is much more computationally efficient, and thus can be incorporated into design optimization process and electrothermal simulations of the electrical machine over a driving cycle.

The presence of antibiotic molecules in the natural water sources is currently a huge problem due to the development of bacterial resistance. Graphene oxide (GO) has a large potential as a candidat...

Chemical technology-based oxidative stress evaluation methods are of particular significance in practical applications. Reactive oxygen species/reactive nitrogen species (ROS/RNS) are inevitable metabolic by-products of the metabolism of the vital processes in living organisms. It has been hypothesized that the redox reaction balance could be coordinated with drugs and other interventions to prevent or treat diseases. Several indicators have been tested as evaluation standards in this field but standardized indicators have been difficult to achieve due to the complex regulation of the redox reactions in different organisms. Therefore, it is inevitable to use multiple methods based on different principles in order to evaluate oxidative stress and antioxidant capacity. In this review, we summarized the oxidative stress and the antioxidant capacity evaluation methods used in various organisms and antioxidant-using methods. We also described the strengths and weaknesses of each method, as well as potential directions for the development of new technologies.

This article performs electromagnetic (EM) and thermal coupled simulation based on two-dimensional (2-D) transient electromagnetic and 3-D thermal model of a triple redundant nine-phase permanent magnet-assisted synchronous reluctance motor under various fault conditions at different speeds. The coupled simulation process is controlled by a scripting file. The resultant temperatures under EM-thermal coupled simulation will be comprehensively compared with those under thermal-only simulation. The predicted current waveforms under fault conditions by the 2-D EM model and predicted temperatures by the 3-D thermal model will be compared with the test results for validation. The outcomes of the study not only gives a better understanding of the thermal behavior, but also provides a guidance to the necessity of the EM-thermal coupled simulation under different fault conditions as well as to determination of the maximum permissible fault detection time before permanent damage due to the fault may occur.

Single crystal silicon wafer is widely used as the substrate material for integrated circuits, and the wafer is cut by wire saw with fixed diamond abrasive owning to the wire saw’s narrow kerf, low cutting force. The cutting force changes during the process operation since the wire change motion direction continuously (i.e., reciprocation) in order to effectively leverage the wire, even if the contact length of wire and part and wire saw tension are fixed, leading to wire saw breakage, wafer collapse, and inferior surface roughness. This paper established the model of cutting force that includes normal force and tangential force, and design the controller for regulating the force via wire velocity control, and the controller obtains the relationship between the normal force and commanded wire velocity. A PI controller experimental studies for Single crystal Silicon wafer wire saw machining are conducted. The results show the controller can well regular the cutting force generated when wire saw machines silicon and on that the wire saw machining process with PI control can decrease wafer surface roughness as compared to the cutting process with a constant wire velocity reciprocation.

Technological advances in the real-time visualization of cutaneous microcirculation aim to realize benefits including high-resolution imaging, suppressed noise, and robust temporal coherence. Photoplethysmography (PPG), a noninvasive technique that measures single or multiple points of relative blood volume changes in blood vessels under the skin, shows potential as a signal candidate for visualizing blood vessels and tracking blood flow. However, challenges still remain, such as extracting/image reconstruction of the blood vessel/flow signal in a precise frequency window (

Inhibition of the immune microenvironment is the main cause of tumor recurrence after surgery in patients with gastric cancer (GC). In this study, immunohistochemistry and multiple immunofluorescence staining were used to evaluate immunosuppressive indicators and immune biomarkers in 825 patients with gastric cancer from three centers. We constructed an immunosuppressive recurrence score (IRS) using LASSO Cox regression based on the expression of six immunosuppressive indicators and found that the IRS and IRS-based nomogram were significantly accurate and reliable in predicting recurrence. Moreover, an elevated IRS was associated with locoregional recurrence and postoperative adjuvant chemotherapy failure. Furthermore, an increase in IRS indicated inhibition of the antitumor effect of CD8(+) tumor-infiltrating lymphocytes in the invasive margin. Thus, we propose that the IRS can predict the recurrence outcome of patients with GC by distinguishing the immunosuppressive status, which is helpful in the selection of individualized adjuvant treatment plans.

This paper proposes a new, to the best of our knowledge, design framework of long-period fiber grating (LPFG) sensors resistant to multi-parameter cross talk. A section of hollow quartz capillary (HQC), which acts as an exoskeleton, is periodically merged with a single-mode fiber (SMF) by the arc-discharge method. The mechanical stress in the SMF is released while the thermal stress is enhanced after a high-temperature fusion process. Under the influence of the elastic-optical effect, the refractive index of the core is periodically modulated along the axial direction to form an exoskeleton long-period fiber grating (Es-LPFG). The unique exoskeleton structure not only induces mode coupling but also enables the proposed device to resist cross talk among the strain, ambient refractive index, and vector bending. The temperature is able to be measured independently with a sensitivity of 74 pm/∘C. The novel Es-LPFG is promising in single-parameter sensing, mode-locked lasers, and frequency-locked gain flattening.

In this paper, numerical simulations combining unsteady Reynolds-averaged Navier-Stokes (URANS) simulation and the discrete phase model are used to study the application of countermeasure for snow accumulation in the regions of bogie cavities of a high-speed train. The influence of the cowcatcher heights and guide structure configurations on the flow features and snow accumulation was studied. The results of the study show that the cowcatcher with a downward elongation of 4% of the distance between the two axles decreases the snow accumulation in the first and the second bogie regions by about 56.6% and 13.6%, respectively. Furthermore, the guide structures have been found to significantly alter the velocity and pressure distribution in the second bogie region, resulting in a relatively large snow-accumulation reduction. The deflector is found to perform better in reducing snow accumulation when compared to the diversion slots. The cowcatcher, elongated in the downward direction, and the deflector proved to be a good countermeasure for snow accumulation around the bogies of high-speed trains operating in snowy weather conditions.

Magnetic polyphosphazene (MPZS) particles coated by Ag nanoparticles (MPZS-Ag) have been developed as surface enhanced Raman spectroscopy (SERS) substrates for sensitive detection of melamine in aqueous solutions and milk samples. 5,5′-Dithiobis-(2-nitrobenzoic acid) (DTNB) was used as model analyte to test the SERS activity of the MPZS-Ag particles. The prepared MPZS-Ag particles possess both magnetic responsiveness and excellent SERS properties. SERS detection of different concentrations of melamine aqueous solutions and spiked milk samples were performed by the MPZS-Ag particles. The limit of detection (LOD) of the melamine in aqueous solutions was 10−7 mol/L (0.0126 mg/L) and 0.6 mg/L in real milk samples using the MPZS-Ag particles as SERS substrates. The LOD of the melamine are much lower than the safety values of Food and Drug Administration and Codex Alimentarius Commission. These results indicate that the MPZS-Ag particles have promising application prospect for SERS analysis in food safety fields.

In the last 20 years, accumulating evidence indicates that the gut microbiota contribute to the development, maturation, and regulation of the host immune system and mediate host anti-pathogen defenses.

Electrochemical removal of nitrogen oxides (NO

Patients with traumatic carotid-cavernous fistula (TCCF) usually go to the ophthalmology department first because of the symptoms such as protrusion of eyes, edema and congestion of combined membrane, vision loss and so on. It is easy to be misdiagnosed and missed.We report a case of left eye swelling and vision loss caused by TCCF after head injury due to traffic accident, which failed to respond to ophthalmic treatment for many times. The similar situation is very likely to cause panic among patients.Cerebral angiography revealed left internal carotid-cavernous fistula (high flow type).Left internal carotid artery covered stent implantation was performed.The fistulas and the original venous mass were completely covered by the covered stent, and the development of the vascular mass disappeared. The patient's eye symptoms basically disappeared 14 days after the operation.Interventional treatment of TCCF is effective.