AbstractThis article describes the research work relating to the assessment and control of human-induced vibration of an unusual curved cable-stayed bridge with separate road and pedestrian decks. ...Dynamic simulations of human-induced vibration were performed with a mode-by-mode approach, and the results showed that a total of eight lateral and vertical modes of the bridge may suffer from excessive vibrations at the design crowd density. A hybrid control scheme was developed for control of human-induced vibration, which consists of steel braces fitted between the road bridge deck and the pedestrian deck to improve structural stiffness and eddy current tuned mass dampers to enhance damping ratios of lively modes. The modal properties of the bridge with steel braces were experimentally obtained by dynamic tests and used for parameter tuning of mass dampers. The performance of the hybrid control strategy was evaluated by group tests of up to 400 pedestrians. It is shown that the critical number of pedestrians triggering synchronous lateral excitation is generally in good agreement with the empirical model developed from measurements on the London Millennium Bridge, but the measured vertical acceleration amplitude is only about 40% of the prediction under the same pedestrian density. The damping ratios for both the vertical and lateral modes increase appreciably after installation of tuned mass dampers and no evidence of large-amplitude vibrations has been observed.
A nontoxic and inexpensive photocatalytic initiation of anti-Markovnikov hydrothiolation of olefins using visible light is reported. This method is characterized by low catalyst loading, thereby ...enabling a mild and selective method for radical initiation in thiol–ene reactions between a wide scope of olefins and thiols.
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•Amygdaloid administration of antioxidants or TRPA1 antagonists attenuated nociception and affective pain in neuropathy.•Blocking spinal 5-HT1A receptors prevented the antinociception ...induced by the amygdaloid drug treatments.•In neuropathy, amygdaloid oxidative stress driving TRPA1 suppressed serotonergic feedback-inhibition of nociception.•Antioxidants and TRPA1 antagonists in the amygdala disinhibited the serotonergic feedback-inhibition of nociception.
Earlier studies indicate that the central nucleus of the amygdala (CeA) contributes to neuropathic pain. Here we studied whether amygdaloid administration of antioxidants or antagonists of TRPA1 that is among ion channels activated by oxidative stress attenuates nociceptive or affective pain in experimental neuropathy, and whether this effect involves amygdaloid astrocytes or descending serotonergic pathways acting on the spinal 5-HT1A receptor. The experiments were performed in rats with spared nerve injury (SNI). Drugs were administered through a chronic cannula in the CeA or internal capsule (control site), and an intrathecal catheter. Nociception was assessed using monofilaments and affective pain using conditioned place-aversion. Antioxidants or TRPA1 antagonists in the CeA attenuated both nociceptive and affective pain in SNI animals but not in sham controls or in a control injection site. Drugs influencing astroglia (a gap junction decoupler or a D-amino acid oxidase inhibitor) in the CeA had no effect on SNI rats, whereas local anesthesia of the CeA attenuated nociception. Spinally administered 5-HT1A receptor antagonist at a dose that had no effect alone prevented the antinociceptive effect of amygdaloid TRPA1 blockers. The results suggest that injury-induced amygdaloid oxidative stress that drives TRPA1 promotes neuropathic pain behavior. This pronociceptive effect involves suppression of medullospinal serotonergic feedback-inhibition acting on the spinal 5-HT1A receptor. While the CeA is involved in mediating the nerve injury-induced pronociception, it may not be a critical relay for the recruitment of medullospinal feedback-inhibition.
Radial nulls, where magnetic field strength becomes zero and the magnetic field lines point radially in the fan plane, are believed to be crucial for particle acceleration and energy dissipation ...during magnetic reconnection. Recent simulations have suggested that reconnection fronts (RFs) embedded in the reconnection jet can be host to radial nulls. However, observational evidence for radial nulls near the RFs remains elusive hitherto, owing to the absence of an efficient null-detection method and high-resolution measurements. Here we present such evidence by using the newly developed First-Order Taylor Expansion method and the high-resolution measurements from the recent MMS mission. For the first time, we confirm the existence of radial nulls near the RFs and find that the upstream region ahead of the RFs can preferentially host the radial nulls. The reconstructed topologies of the observed radial nulls are consistent with theoretical models. Associated with these radial nulls, no clear particle and wave activities were found, meaning that they were inactive during the observations.
Acinetobacter baumannii can cause severe nosocomial and community-acquired pneumonia. To study the pathogenesis of A. baumannii and to develop new treatments, appropriate mouse models are needed. ...Most reported mouse models of pulmonary A. baumannii infection are non-lethal or require mouse immunosuppression to enhance infection. These models are not suitable for studying host immune responses or evaluating immunotherapies.
The virulence of 30 clinical isolates was assessed in mice. The most virulent isolate, SJZ24, was selected to develop a pneumonia model in immunocompetent mice. The cytokine mRNA expression in the lung was assessed with real-time PCR. The cell infiltration in bronchoalveolar lavage fluid (BALF) after SJZ24 infection was determined by flow cytometry. Vaccine efficacy was assessed using this model.
Intratracheal inoculation of SJZ24 (5 × 107 CFU) resulted in death in 100% of the mice (5/5). SJZ24-infected mice showed high bacterial burdens in blood and organs as well as severe lung-tissue damage. Infection with SJZ24 induced increased inflammatory cytokine expression in the lung and increased neutrophil infiltration in BALF. Immunization with inactivated whole cells of SJZ24 showed 100% protection (5/5) against A. baumanni infection in this model.
We established a lethal pneumonia model in immunocompetent mice with hypervirulent A. baumannii isolate SJZ24. This model can be used to study the immune response to A. baumannii infection and to evaluate vaccine efficacy.
Due to the feasibility of the gray model for predicting time series with small samples, the gray theory is well investigated since it is presented and is currently evolved in an important manner for ...forecasting small samples. This study proposes a new gray prediction criterion based on the neural ordinary differential equation, which is named the neural ordinary differential gray mode. This neural ordinary differential gray mode permits the forecasting model to be learned by a training process which contains a new whitening equation. It is needed to prepare the structure and time series, compared with other models, according to the regularity of actual specimens in advance, therefore this model of neural ordinary differential gray mode can provide comprehensive applications as well as learning the properties of distinct data specimens. To acquire a better model which has highly predictive efficiency, afterward, this study trains the model by neural ordinary differential gray mode using the Runge–Kutta method to obtain the prediction sequence and solve the model. The controller establishes an advantageous theoretical foundation in adapting to novel wheels and comprehensively spreads the utilize extent of mechanical elastic vehicle wheel.
Dentin is a major mineralized component of teeth. Odontoblasts are responsible for synthesis and secretion of dentin matrix. Previously, it has been demonstrated in a cell culture system that the E3 ...ubiquitin ligase, murine double minute 2 (Mdm2), promotes odontoblast-like differentiation of mouse dental papilla cells (mDPCs) by ubiquitinating p53 and the odontoblast-specific substrate Dlx3. However, whether Mdm2 plays an essential role in vivo in odontoblast differentiation and dentin formation remains unknown. In this study, we investigated the in vivo functions of Mdm2 using Dmp1-Cre;Mdm2
flox/flox
mice combined with multiple histological and molecular biological methods. The results showed that Mdm2 deletion in the odontoblast layer led to defects in odontoblast differentiation and dentin formation. Unexpectedly, specific inhibition of the Mdm2-p53 axis in wild-type mice by injection of a small-molecule inhibitor Nutlin-3a indicated that the role of Mdm2 in dentinogenesis was p53 independent, which was inconsistent with the previous in vitro study. In situ proximity ligation assay (PLA) showed that Mdm2 interacted with and ubiquitinated Dlx3 in the odontoblast nucleus of mouse molars. Dlx3 promoted the translocation of Mdm2 to the nucleus, and in turn, the nuclear Mdm2 mediated ubiquitination of Dlx3 and promoted the odontoblast-like differentiation of mDPCs. Dlx3 interacted with Mdm2 through its C-terminal domain. Deletion of the C-terminal domain of Dlx3 reversed the enhanced odontoblast-like differentiation and the activation of Dspp promoter mediated by overexpression of wild-type or nuclear Mdm2. Our findings suggest that nuclear Mdm2 mediates ubiquitination of the transcription factor Dlx3, which is essential for Dlx3 transcriptional activity on Dspp as well as subsequent odontoblast differentiation and dentin formation.
Cornstarch in water exhibits impact-activated solidification (IAS) and strong discontinuous shear thickening, with "shear jamming". However, these phenomena are absent in cornstarch in ethanol. Here ...we show that cornstarch granules swell under ambient conditions. We postulate that this granule swelling is linked to an interparticle force scale that introduces a discontinuous rate-dependence to the generation of stable contacts between granules. We studied this force scale by coating sand with ~ 2 μm-thick polydimethysiloxane, creating a material that exhibits a similar IAS and discontinuous deformation rate-stiffening despite being a granular composite, not a suspension. This result suggests rate-dependence can be tuned by coating granular materials, introducing an interparticle force scale from rate-dependent properties present in the coating material. Our work provides insights into the unique behavior of cornstarch in water, bridges our understanding of suspensions and dry granular materials, and introduces a method to make discontinuous rate-dependent materials without suspending particles.
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