152 research outputs found

    Numerical computation of wheel-rail impact noises with considering wheel flats based on the boundary element method

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    When a wheel rolls to a flat, it can generate the impact force several multiples larger than that generated at the common time. The paper established a wheel-rail coupling vibration model with wheel flat, and vibration acceleration responses of the rail was computed. The computational result was then compared with the experimental result. Good consistency between simulation and experiment indicated that the finite element model is reliable. Then, based on the finite element model and boundary element model, the paper established a structural-acoustic coupling boundary element model and computed the radiation noise of wheel-rail under effects of wheel flats. Results show that: the wheel flats were an important reason for wheel rail impact noises, impact noises of wheel flats were mainly concentrated in frequency bands of over 250 Hz, and impact noises of wheel flats were closely related with wheel flat length, quantity of wheel flats as well as running speeds. With the increase of these parameters, the radiation noise of wheel flats would be increased correspondingly

    Polysaccharides from the Chinese medicinal herb Achyranthes bidentata enhance anti-malarial immunity during Plasmodium yoelii 17XL infection in mice

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    <p>Abstract</p> <p>Background</p> <p>Clinical immunity to malaria in human populations is developed after repeated exposure to malaria. Regulation and balance of host immune responses may lead to optimal immunity against malaria parasite infection. Polysaccharides (ABPS) derived from the Chinese herb ox knee <it>Achyranthes bidentata </it>possess immuno-modulatory functions. The aim of this study is to use the rodent malaria model <it>Plasmodium yoelii </it>17XL (<it>P. y</it>17XL) to examine whether pretreatment with ABPS will modulate host immunity against malaria infection and improve the outcome of the disease.</p> <p>Methods</p> <p>To determine whether ABPS could modulate immunity against malaria, mice were pretreated with ABPS prior to blood-stage infection by <it>P. y</it>17XL. Host survival and parasitaemia were monitored daily. The effect of pretreatment on host immune responses was studied through the quantitation of cytokines, dendritic cell populations, and natural regulatory T cells (Treg).</p> <p>Results</p> <p>Pretreatment with ABPS prior to infection significantly extended the survival time of mice after <it>P. y</it>17XL infection. At three and five days post-infection, ABPS pretreated mice developed stronger Th1 immune responses against malaria infection with the number of F4/80<sup>+</sup>CD36<sup>+ </sup>macrophages and levels of IFN-γ, TNF-α and nitric oxide being significantly higher than in the control group. More importantly, ABPS-treated mice developed more myeloid (CD11c<sup>+</sup>CD11b<sup>+</sup>) and plasmacytoid dendritic cells (CD11c<sup>+</sup>CD45R<sup>+</sup>/B220<sup>+</sup>) than control mice. ABPS pretreatment also resulted in modulated expression of MHC-II, CD86, and especially Toll-like receptor 9 by CD11c<sup>+ </sup>dendritic cells. In comparison, pretreatment with ABPS did not alter the number of natural Treg or the production of the anti-inflammatory cytokine IL-10.</p> <p>Conclusion</p> <p>Pretreatment with the immuno-modulatory ABPS selectively enhanced Th1 immune responses to control the proliferation of malaria parasites, and prolonged the survival of mice during subsequent malaria infection.</p

    Tryptophan-rich domains of Plasmodium falciparum SURFIN4.2 and Plasmodium vivax PvSTP2 interact with membrane skeleton of red blood cell

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    Additional file 1: Table S1. Primers for PCR amplification and plasmid construction

    An effective simulation analysis of transient electromagnetic multiple faults

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    Embedded encryption devices and smart sensors are vulnerable to physical attacks. Due to the continuous shrinking of chip size, laser injection, particle radiation and electromagnetic transient injection are possible methods that introduce transient multiple faults. In the fault analysis stage, the adversary is unclear about the actual number of faults injected. Typically, the single-nibble fault analysis encounters difficulties. Therefore, in this paper, we propose novel ciphertext-only impossible differentials that can analyze the number of random faults to six nibbles. We use the impossible differentials to exclude the secret key that definitely does not exist, and then gradually obtain the unique secret key through inverse difference equations. Using software simulation, we conducted 32,000 random multiple fault attacks on Midori. The experiments were carried out to verify the theoretical model of multiple fault attacks. We obtain the relationship between fault injection and information content. To reduce the number of fault attacks, we further optimized the fault attack method. The secret key can be obtained at least 11 times. The proposed ciphertext-only impossible differential analysis provides an effective method for random multiple faults analysis, which would be helpful for improving the security of block ciphers

    The Efficacy and Safety of Chinese Herbal Decoction in Type 2 Diabetes: A 5-Year Retrospective Study

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    Background. The study was designed to assess the efficacy and safety of Chinese herbal decoction in treating outpatients with T2DM. Methods. All patients enrolled received decoction for at least 6 months. The primary outcome was the control rate of HbA1c and the change in HbA1c. FPG, 2hPG, HOMA-IR, and HOMA-β were also collected and evaluated. Results. The control rates after treatment at months 6, 12, 18, 24, 36, 48, and 60 were 45.07%, 52.78%, 47.22%, 45.83%, 50.00%, 57.14%, and 40.00%. Multiple linear regression showed the change of HbA1c has a significant relationship with the baseline HbA1c and duration of DM and BMI (p<0.05). Both FPG and 2hPG levels significantly decreased compared to the baseline (p<0.05). Chinese herbal decoction also improved islet cell function with decreased HOMA-IR and increased HOMA-β (p<0.05). 19 and 4 subjects deactivated the antidiabetes drugs or insulin, respectively, after taking decoction. One subject developed DKD and one developed DPN, and another subject showed abnormal liver function which was irrelevant to decoction treatment. Conclusions. Chinese herbal decoction significantly enhanced the hypoglycemic action and had certain effect on protecting islet cell function. As a candidate diabetes therapy, it may reduce the use of antidiabetes drugs and slow the progression to diabetes complications

    Valley-polarized Exitonic Mott Insulator in WS2/WSe2 Moir\'e Superlattice

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    Strongly enhanced electron-electron interaction in semiconducting moir\'e superlattices formed by transition metal dichalcogenides (TMDCs) heterobilayers has led to a plethora of intriguing fermionic correlated states. Meanwhile, interlayer excitons in a type-II aligned TMDC heterobilayer moir\'e superlattice, with electrons and holes separated in different layers, inherit this enhanced interaction and strongly interact with each other, promising for realizing tunable correlated bosonic quasiparticles with valley degree of freedom. We employ photoluminescence spectroscopy to investigate the strong repulsion between interlayer excitons and correlated electrons in a WS2/WSe2 moir\'e superlattice and combine with theoretical calculations to reveal the spatial extent of interlayer excitons and the band hierarchy of correlated states. We further find that an excitonic Mott insulator state emerges when one interlayer exciton occupies one moir\'e cell, evidenced by emerging photoluminescence peaks under increased optical excitation power. Double occupancy of excitons in one unit cell requires overcoming the energy cost of exciton-exciton repulsion of about 30-40 meV, depending on the stacking configuration of the WS2/WSe2 heterobilayer. Further, the valley polarization of the excitonic Mott insulator state is enhanced by nearly one order of magnitude. Our study demonstrates the WS2/WSe2 moir\'e superlattice as a promising platform for engineering and exploring new correlated states of fermion, bosons, and a mixture of both

    CD153/CD30 signaling promotes age-dependent tertiary lymphoid tissue expansion and kidney injury

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    高齢者腎臓病を悪化させる原因細胞・分子の同定に成功. 京都大学プレスリリース. 2021-11-30.A new drug target for kidney disease. 京都大学プレスリリース. 2021-11-30.Tertiary lymphoid tissues (TLTs) facilitate local T- and B-cell interactions in chronically inflamed organs. However, the cells and molecular pathways that govern TLT formation are poorly defined. Here we identify TNF superfamily CD153-CD30 signaling between two unique age-dependent lymphocyte subpopulations, CD153⁺PD-1⁺CD4⁺ senescence-associated T (SAT) cells and CD30+T-bet+ age-associated B cells (ABCs), as a driver for TLT expansion. SAT cells, which produced ABC-inducing factors IL21 and IFNγ, and ABCs progressively accumulated within TLTs in aged kidneys after injury. Notably, in kidney injury models, CD153 or CD30 deficiency impaired functional SAT cell induction, which resulted in reduced ABC numbers and attenuated TLT formation with improved inflammation, fibrosis and renal function. Attenuated TLT formation after transplantation of CD153-deficient bone marrow further supported the importance of CD153 in immune cells. Clonal analysis revealed that SAT cells and ABCs in the kidneys arose from both local differentiation and recruitment from the spleen. In the synovium of aged rheumatoid arthritis patients, T peripheral helper/T follicular helper cells and ABCs also expressed CD153 and CD30, respectively. Together, our data reveal a previously unappreciated function of CD153-CD30 signaling in TLT formation and propose targeting CD153-CD30 signaling pathway as a therapeutic target for slowing kidney disease progression
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