Characteristics of LDPE and Oriented Montmorillonite Nanocomposites Produced by Electric Field-inducement

In order to make montmorillonite (MMT) nanosheets disperse in low-density polyethylene (LDPE) with highly homogeneous orientation, alternating voltage is applied to molten LDPE with MMT nanosheets. The effect of electric field on the dispersion of MMT in the solidified LDPE is studied. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses suggest that the MMT nano- sheets are aligned with high anisotropy to the electric field direction, which is perpendicular to the LDPE film plane. Differential scanning calorimetry (DSC) results reveal that the crystallization degree of the oriented LDPE/MMT composite increases. Moreover, through a broadband dielectric spectroscopy analyzer, it is found that MMT manifests a significantly influence in the dielectric property of the oriented composite: the dielectric constant and loss tangent of the composite both become larger. Analysis shows that the electric field-induced torque caused by the polarization of MMT flakes is the main force inducing the orientation of the MMT flakes.

Moving beyond Wastewater:Perspectives on Environmental Surveillance of Infectious Diseases for Public Health Action in Low-Resource Settings

Although testing wastewater for public health surveillance has recently received significant attention in the United States,researchers and public health professionals have long realized the tremendous promise of environmental surveillance(ES),defined as tracking pathogens of interest in fecally contaminated surface waters,soil,or fomites,in low-resource settings for public health action.1,2 The power of ES in lowresource settings is most clearly illustrated with the over 30 years of well-established and standardized polio surveillance.As part of the Global Polio Eradication Initiative,the World Health Organization(WHO)has accredited 146 laboratories within the Global Polio Lab Network(GPLN).These facilities across 92 countries process over 8,000 wastewater or fecally contaminated surface water samples per year,in addition to over 220,000 stool samples annually.3 The data generated from the GPLN are closely linked to clear public health action related to targeted vaccination campaigns.The investment and adoption of ES for polio eradication efforts serves as a use-case for other targets of interest.To explore the current state of the field,the National Science Foundation-funded Research Coordination Network(RCN)on Wastewater Based Epidemiology for SARS-CoV-2 and Emerging Public Health Threats held a workshop in December 2023 to discuss the opportunities and challenges for ES in low-resource settings(Figure 1).Discussions during the workshop highlighted knowledge gaps,best-practices,target selection,academic/government/private partnerships and overall public health action and sustainability of these programs.

PD-1 induction through TCR activation is partially regulated by endogenous TGF-β

The programmed death 1 （PD-1） pathway is a way of inhibiting T-cell proliferation and cytokine production. This pathway is important for maintaining peripheral tolerance. Different mechanisms and cytokines are involved in this pathway. Herein, we show the contribution of endogenous TGF-β to increasing PD-1 expression after T cell receptor （TCR） activation.