Performance of the non-invasive point-of-care device, EzeCheck, for haemoglobin assessment in adults and children in community and institutional care settings.

Anaemia is a major public health problem, especially in resource constrained settings. Dependency on assessment of blood hemoglobin (Hgb) concentration impedes anemia detection, risk stratification and intervention. Thus, valid, frugal and scalable technologies are needed. EzeCheck is a noninvasive portable device developed in India for predicting hemoglobin levels in human beings aged 4 years and above using a finger-tip biosensor. In this assessment, we aimed to: (i) evaluate EzeCheck's performance with an automated whole blood hemato-analyzer (Sysmex XN 1000) as the gold standard, and (ii) estimate EzeCheck's agreement with Sahli's method and HemoCue (Hb-301) in real-world primary and higher care facilities. Paired assessments were done at five sites across India i.e., Bhubaneshwar, Shimla, Solan and Mashobra and Ulhasnagar. Participants across all age groups (4 years and above) were assessed. We used a range of statistical tests to evaluate the performance of EzeCheck. It was found that EzeCheck performed well across age and gender categories with convincing validity, concordance, precision and accuracy, and acceptable bias. While comparing EzeCheck with Hemato-analyzer, no statistically significant systematic bias was found. However, EzeCheck showed significant systematic bias when compared to Sahli's method and HemoCue. We concluded that EzeCheck could detect anemia (as per WHO Hgb cut-offs) in 'real-world settings' and 'across age and gender categories', with high sensitivity, specificity and accuracy, and can serve as a replacement to traditional methods of hemoglobin assessment. Further, for countries with higher prevalence of anemia where universal screening may be mandated, the positive predictive value of EzeCheck will be higher. The likelihood ratios also indicated that the device had moderate-to-good utility. EzeCheck is suitable for embedment into program and out-patient health care settings in resource constrained contexts as a spot-check hemoglobinometer.

Water Adsorption Isotherm and Surface Conductivity of Boroaluminosilicate Glasses.

The surface resistivity of boroaluminosilicate display glasses, which may affect the downstream display panel manufacturing, varies with the relative humidity (RH) of the environment, but the origin of this RH dependence has not been well understood. We have measured the water adsorption behavior on Corning Eagle XG (Glass-E) and Lotus NXT (Glass-L) glass panels using Brewster angle transmission infrared spectroscopy. The IR spectra of adsorbed water were analyzed to obtain the effective thickness of adsorbed water, the distribution of hydrogen-bonding interactions among the adsorbed water molecules, and the isosteric heat of water adsorption. These characteristics were compared with the electrical conductivity (inverse of resistivity) of these two glasses [Appl. Surf. Sci. 2015, 356, 1189]. This comparison revealed the correlation between the conductivity and the water layer structure, which could explain the surface resistivity difference between Glass-E and Glass-L as a function of RH. This study also disputed the previous hypothesis that the water adsorption isotherm would be governed by the areal density of the surface hydroxyl group; instead, it suggested that the network modifier ions may also play a critical role, especially in the intermediate RH regime.

Adolescent perspectives on peripartum mental health prevention and promotion from Kenya: Findings from a design thinking approach.

In Kenya, approximately one in five girls aged 15-19 years old are pregnant or already a mother. Adolescent girls and young women experience significant mental health vulnerabilities during the pregnancy and postpartum periods, leading to poor antenatal and postnatal care attendance and inferior infant and maternal health outcomes. Pregnant adolescents often experience stigma and disenfranchisement due to their pregnancy status and at the same time lack access to mental health support within health settings, schools, religious institutions, and communities. This paper presents the results of qualitative interviews embedded within the human-centered design (HCD) process used to adapt the Helping Adolescents Thrive (HAT) program for Kenyan peripartum adolescents including young fathers. This qualitative study used two phases. First, a HAT advisory group participated in a series of four workshops to help identify and articulate mental health promotion needs and deepened the team's understanding of youth-centered thinking. Second, qualitative interviews were conducted with 39 pregnant and parenting adolescents to understand their perspectives on mental health prevention and promotion. Pregnant and parenting adolescents articulated different needs including poor support, stigma, and psychological disturbances. Parenting adolescents reported disturbed relationships, managing motherhood, poor health, and social empowerment. Participants highlighted sources of stress including economic challenges, fear of delivery, strained relationships, rejection, and stigma. Participants described psychological disturbances such as feeling stressed, worthless, withdrawn, and suicidal. Coping mechanisms reported by participants included engaging in domestic activities, hobbies, and social networking. Peers, family and spirituality were identified as important sources of support, as well as school integration, livelihoods, support groups and mentorships. Findings from this study can be used to strengthen and adapt HAT program, policy and practice for mental health prevention and promotion for pregnant and parenting adolescents.

Prediction of glassy silica etching with hydrogen fluoride gas by kinetic Monte Carlo simulations.

Understanding the surface properties of glass during the hydrogen fluoride (HF)-based vapor etching process is essential to optimize treatment processes in semiconductor and glass industries. In this work, we investigate an etching process of fused glassy silica by HF gas with kinetic Monte Carlo (KMC) simulations. Detailed pathways of surface reactions between gas molecules and the silica surface with activation energy sets are explicitly implemented in the KMC algorithm for both dry and humid conditions. The KMC model successfully describes the etching of the silica surface with the evolution of surface morphology up to the micron regime. The simulation results show that the calculated etch rate and surface roughness are in good agreement with the experimental results, and the effect of humidity on the etch rate is also confirmed. Development of roughness is theoretically analyzed in terms of surface roughening phenomena, and it is predicted that the values of growth and roughening exponents are 0.19 and 0.33, respectively, suggesting that our model belongs to the Kardar-Parisi-Zhang universality class. Furthermore, the temporal evolution of surface chemistry, specifically surface hydroxyls and fluorine groups, is monitored. The surface density of fluorine moieties is 2.5 times higher than that of the hydroxyl groups, implying that the surface is well fluorinated during vapor etching.

Passivation of Mid-Gap Electronic States at Calcium Aluminosilicate Glass Surfaces upon Water Exposure: An Ab Initio Study.

When a clean glass surface is exposed to humid air, a thin water layer forms on the hydrophilic surface. Using ab initio molecular dynamics, we simulate the changes in the electronic structure of a CaO-Al2O3-SiO2 glass model upon vacuum fracture and subsequent exposure to H2O. When the glass is fractured, dangling bonds form, which lower the band gap of the surface by ∼1.8 eV compared to the bulk value due to mid-gap surface states. When H2O adsorbs onto the vacuum-fractured surface, the band gap increases to a value closer to that of the bulk band gap. Using two different hydroxylation methods, we find that the calculated band gap of the glass surface depends on the hydroxylation state. Surfaces with ∼4.5 OH/nm2 have smaller band gaps due to unfilled surface states, and surfaces with ∼2.5 OH/nm2 have larger band gaps with no apparent unfilled surface states. The resulting changes in the electronic structure, quantified by electron affinity and work function values, are hypothesized to play an important role in the electrostatic charge transfer based on the principles of surface state theory, which posit that the density of electronic surface states determines the amount of electronic charge transfer to or from material surfaces.

Photothermal Atomic Force Microscopy Coupled with Infrared Spectroscopy (AFM-IR) Analysis of High Extinction Coefficient Materials: A Case Study with Silica and Silicate Glasses.

Photothermal atomic force microscopy coupled with infrared spectroscopy (AFM-IR) brings significant value as a spatially resolved surface analysis technique for disordered oxide materials such as glasses, but additional development and fundamental understanding of governing principles is needed to interpret AFM-IR spectra, since the existing theory described for organic materials does not work for materials with high extinction coefficients for infrared (IR) absorption. This paper describes theoretical calculation of a transient temperature profile inside the IR-absorbing material considering IR refraction at the interface as well as IR adsorption and heat transfer inside the sample. This calculation explains the differences in peak positions and amplitudes of AFM-IR spectra from those of specular reflectance and extinction coefficient spectra. It also addresses the information depth of the AFM-IR characterization of bulk materials. AFM-IR applied to silica and silicate glass surfaces has demonstrated novel capability of characterizing subsurface structural changes and surface heterogeneity due to mechanical stresses from physical contacts, as well as chemical alterations manifested in surface layers through aqueous corrosion.

Vibrational Sum Frequency Generation Spectroscopy Study of Hydrous Species in Soda Lime Silica Float Glass.

It is generally accepted that the mechanical properties of soda lime silica (SLS) glass can be affected by the interaction between sodium ions and hydrous species (silanol groups and water molecules) in its surface region. While the amount of these hydrous species can be estimated from hydrogen profiles and infrared spectroscopy, their chemical environment in the glass network is still not well understood. This work employed vibrational sum frequency generation (SFG) spectroscopy to investigate the chemical environment of hydrous species in the surface region of SLS float glass. SLS float glass shows sharp peaks in the OH stretching vibration region in SFG spectra, while the OH stretch peaks of glasses that do not have leachable sodium ions and the OH peaks of water molecules in condensed phases are normally broad due to fast hydrogen bonding dynamics. The hydrous species responsible for the sharp SFG peaks for the SLS float glass were found to be thermodynamically more stable than physisorbed water molecules, did not exchange with D2O, and were associated with the sodium concentration gradient in the dealkalized subsurface region. These results suggested that the hydrous species reside in static solvation shells defined by the silicate network with relatively slow hydrogen bonding dynamics, compared to physisorbed water layers on top of the glass surface. A putative radial distribution of the hydrous species within the SLS glass network was estimated based on the OH SFG spectral features, which could be compared with theoretical distributions calculated from computational simulations.

Adsorption reactions of carboxylic acid functional groups on sodium aluminoborosilicate glass fiber surfaces.

Multicomponent silicate glasses are ubiquitous in modern society as evidenced by their inclusion in applications ranging from building materials and microelectronics to biomedical implants. Of particular interest in this study is the interface between multicomponent silicate glasses and adhesive polymers. These polymeric systems often possess a variety of different organic functional groups. In this study, we selected acetic acid as a probe molecule representative of the carboxylic acid functional group found in many adhesives. We have used Fourier transform infrared spectroscopy (FT-IR) and NMR to study the interaction of acetic acid with the surface of sodium aluminoborosilicate continuous glass fibers. Methods were developed that enable analyses to be carried out without damaging or altering the pristine as drawn fiber surface. While dosing the surface of fumed silica with acetic acid resulted in the formation of silyl ester groups, analogous dosing of sodium aluminoborosilicate glass fibers resulted in the formation of carboxylate species, principally coordinated to sodium, while silyl ester groups were not observed.