343 research outputs found

    Influences of vaccination and public health strategies on COVID-19 dynamics in the United States: Evaluating policy impacts, behavioral responses, and variant proliferation

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    Background and Aim: The United States (US) government implemented interventions against COVID-19, but their effects on variant-related risks remain inconclusive. We aimed to assess the causal effects of vaccination rates, booster uptakes, face mask mandates, and public area mobility (societal behavioral factor) on early-stage COVID-19 case and death growth rates and identify the most effective public health response for controlling COVID-19 in the US. Materials and Methods: We performed retrospective analyses using four standard correlated random effects models, analyzing a robust panel dataset that encompasses 16,700 records across all fifty US states. Models 1 and 3 analyzed COVID-19 case rates and death growth rates, respectively, from January 2021 to November 2021. In contrast, using the data from August 2021 to November 2021, Models 2 and 4 assessed the effect of Delta variants and booster shots on COVID-19 case and death growth rates, respectively. Results: We found that face mask mandate (p < 0.01) and workplace mobility (p < 0.05) led to lower COVID-19 case growth rates. COVID-19 vaccination uptake rate reduced COVID-19 death growth rates (p < 0.01). Furthermore, contrary to Epsilon variant (p < 0.01), which contributed to reduced COVID-19 case growth rates, Delta variant led to significant increases in COVID-19 cases (p < 0.001). Conclusion: This study suggests that immediate public health interventions, like mask mandates, are crucial for crisis mitigation, while long-term solutions like vaccination effectively address pandemics. The findings of this study not only sheds light on the recent pandemic but also equips policy-makers and health professionals with tools and knowledge to tackle future public health emergencies more effectively

    Physical model for the gating mechanism of ionic channels

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    We propose a physical model for the gating mechanism of ionic channels. First, we investigate the fluctuation-mediated interactions between two proteins imbedded in a cellular membrane and find that the interaction depends on their orientational configuration as well as the distance between them. The orientational dependence of interactions arises from the fact that the noncircular cross-sectional shapes of individual proteins constrain fluctuations of the membrane differently according to their orientational configuration. Then, we apply these interactions to ionic channels composed of four, five, and six proteins. As the gating stimulus creates the changes in the structural shape of proteins composing ionic channels, the orientational configuration of the ionic channels changes due to the free energy minimization, and ionic channels are open or closed according to the conformation thereof.open3

    Magnetostriction-polarization coupling in multiferroic Mn2MnWO6

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    Double corundum-related polar magnets are promising materials for multiferroic and magnetoelectric applications in spintronics. However, their design and synthesis is a challenge, and magnetoelectric coupling has only been observed in Ni3TeO6 among the known double corundum compounds to date. Here we address the high-pressure synthesis of a new polar and antiferromagnetic corundum derivative Mn2MnWO6, which adopts the Ni3TeO6-type structure with low temperature first-order field-induced metamagnetic phase transitions (T N = 58 K) and high spontaneous polarization (~ 63.3 μC·cm−2). The magnetostriction-polarization coupling in Mn2MnWO6 is evidenced by second harmonic generation effect, and corroborated by magnetic-field-dependent pyroresponse behavior, which together with the magnetic-field-dependent polarization and dielectric measurements, qualitatively indicate magnetoelectric coupling. Piezoresponse force microscopy imaging and spectroscopy studies on Mn2MnWO6 show switchable polarization, which motivates further exploration on magnetoelectric effect in single crystal/thin film specimens

    The Key Role of c-Fos for Immune Regulation and Bacterial Dissemination in Brucella Infected Macrophage

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    The cellular oncogene c-Fos (c-Fos) is a component of activator protein 1 (AP1), a master transcriptional regulator of cells. The suppression of c-Fos signaling by siRNA treatment resulted in significant induction of TLR4, which subsequently activates p38 and ERK1/2 mitogen-activated protein kinases (MAPKs) and enhances F-actin polymerization, leading to an increase in B. abortus phagocytosis. During B. abortus infection, c-Fos signaling is induced, which activates the downstream innate-immunity signaling cascade for bacterial clearance. The inhibition of c-Fos signaling led to increased production of interleukin 10 (IL-10), which partially suppressed lysosome-mediated killing, resulting in increased survival of B. abortus inside macrophages. We present evidence of the regulatory role played by the c-Fos pathway in proliferation during B. abortus infection; however, this was independent of the anti-Brucella effect of this pathway. Another finding is the essential contribution of c-Fos/TRAIL to infected-cell necrosis, which is a key event in bacterial dissemination. These data provide the mechanism via which c-Fos participates in host defense mechanisms against Brucella infection and in bacterial dissemination by macrophages

    Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

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    The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections
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