Impact of the 2016 Presidential election and restrictive immigration climate on the work and wellbeing of Bangladeshi immigrant community frontline workers in New York City, U.S.A.

Community-based organizations (CBOs) are key players in mitigating the impact of restrictive policy changes on immigrant communities. The ability of these organizations to help diffuse the stress caused by restrictive, rapidly changing immigration policies depends, in part, on the capacity and health of their workforce. This study presents findings from a qualitative study conducted with 10 Bangladeshi community frontline workers working in various CBOs and advocacy organizations to understand their experience navigating a heightened anti-immigrant, anti-Muslim climate. Through thematic analyses, we inferred that the 2016 presidential election increased stress and mobilization among community frontline workers, with a meaningful distinction between participants working for immigration-focused institutions versus those in institutions where immigration issues were not the primary focus (e.g. health services, cultural programming). For those working in immigration-focused institutions, work burden increased due to challenges in managing misinformation, making sense of policy changes, and meeting the needs of families impacted by deportation. A toll on frontline workers' own physical health and mental health was discussed, as well as the need for culturally congruent mental health supports for the South Asian community.

A calibration-free approach to detecting microRNA with DNA-modified gold coated magnetic nanoparticles as dispersible electrodes.

Gold coated magnetic nanoparticles (Au@MNPs), modified with DNA sequences give dispersible electrodes that can detect ultralow amounts of microRNAs and other nucleic acids but, as with most other sensors, they require calibration. Herein we show how to adapt a calibration free approach for electrochemical aptamer-based sensors on bulk electrodes to microRNA (miR-21) detection with methylene blue terminated DNA modified Au@MNPs. The electrochemical square wave voltammetry signal from the DNA-Au@MNPs when collected at a bulk electrode under magnetic control, decreases upon capture of miR-21. We show that the square wave voltammogram has concentration dependent and independent frequencies that can be used to give a calibration free signal.

Rapid and ultrasensitive electrochemical detection of circulating tumor DNA by hybridization on the network of gold-coated magnetic nanoparticles.

An accurate and robust method for quantifying the levels of circulating tumor DNA (ctDNA) is vital if this potential biomarker is to be used for the early diagnosis of cancer. The analysis of ctDNA presents unique challenges because of its short half-life and ultralow abundance in early stage cancers. Here we develop an ultrasensitive electrochemical biosensor for rapid detection of ctDNA in whole blood. The sensing of ctDNA is based on hybridization on a network of probe DNA modified gold-coated magnetic nanoparticles (DNA-Au@MNPs). This DNA-Au@MNPs biosensor can selectively detect short- and long-strand DNA targets. It has a broad dynamic range (2 aM to 20 nM) for 22 nucleotide DNA target with an ultralow detection limit of 3.3 aM. For 101 nucleotide ctDNA target, a dynamic range from 200 aM to 20 nM was achieved with a detection limit of 5 fM. This DNA-Au@MNPs based sensor provides a promising method to achieve 20 min response time and minimally invasive cancer early diagnosis.

Stressors, Legal Vulnerability and Bangladeshi Parent and Child Well-Being in New York City.

A growing body of research is documenting the impact of parental legal status on familial and child well-being in the U.S. This study adds to the literature by examining the relation of legal vulnerability with the health and mental health of Bangladeshi immigrant parents and their children. A cross-sectional study with 73 immigrant Bangladeshi families was conducted in New York City. Parents reported on legal status indicators, perceived stressors, health, and child mental health indicators. Parents with greater legal vulnerability reported significantly greater immigration-related stressors and poorer perceived health outcomes for themselves and their children in comparison with parents having less legal vulnerability. Immigration stressors explained a significant amount of variance in parent symptoms of depression, tension, and sleep problems and child mental health indicators, beyond the variance explained by acculturation stress and financial stress. Practitioners should be aware that legal vulnerability and associated immigration stressors are adversely associated with Bangladeshi health and mental health.

Impact of the Coverage of Aptamers on a Nanoparticle on the Binding Equilibrium and Kinetics between Aptamer and Protein.

Knowledge of the interaction between aptamer and protein is integral to the design and development of aptamer-based biosensors. Nanoparticles functionalized with aptamers are commonly used in these kinds of sensors. As such, studies into how the number of aptamers on the nanoparticle surface influence both kinetics and thermodynamics of the binding interaction are required. In this study, aptamers specific for interferon gamma (IFN-γ) were immobilized on the surface of gold nanoparticles (AuNPs), and the effect of surface coverage of aptamer on the binding interaction with its target was investigated using fluorescence spectroscopy. The number of aptamers were adjusted from an average of 9.6 to 258 per particle. The binding isotherm between AuNPs-aptamer conjugate and protein was modeled with the Hill-Langmuir equation, and the determined equilibrium dissociation constant (K'D) decreased 10-fold when increasing the coverage of aptamer. The kinetics of the reaction as a function of coverage of aptamer were also investigated, including the association rate constant (kon) and the dissociation rate constant (koff). The AuNPs-aptamer conjugate with 258 aptamers per particle had the highest kon, while the koff was similar for AuNPs-aptamer conjugates with different surface coverages. Therefore, the surface coverage of aptamers on AuNPs affects both the thermodynamics and the kinetics of the binding. The AuNPs-aptamer conjugate with the highest surface coverage is the most favorable in biosensors considering the limit of detection, sensitivity, and response time of the assay. These findings deepen our understanding of the interaction between aptamer and target protein on the particle surface, which is important to both improve the scientific design and increase the application of aptamer-nanoparticle based biosensor.

Single particle detection of protein molecules using dark-field microscopy to avoid signals from nonspecific adsorption.

A massively parallel single particle sensing method based on core-satellite formation of Au nanoparticles was introduced for the detection of interleukin 6 (IL-6). This method exploits the fact that the localized plasmon resonance (LSPR) of the plasmonic nanoparticles will change as a result of core-satellite formation, resulting in a change in the observed color. In this method, the hue (color) value of thousands of 67 nm Au nanoparticles immobilized on a glass coverslip surface is analyzed by a Matlab code before and after the addition of reporter nanoparticles containing IL-6 as target protein. The average hue shift as the result of core-satellite formation is used as the basis to detect small amount of proteins. This method enjoys two major advantages. First it is able to analyze the hue values of thousands of nanoparticles in parallel in less than a minute. Secondly the method is able to circumvent the effect of non-specific adsorption, a major issue in the field of biosensing.