Analysis of an electrospun nanofiber device applicable to limb salvage: mass loss, morphological changes, and quantification of antibiotic release

The creation of an electrospun nanofiber embedded with two antibiotics that will be used to prevent infection while also stimulating bone regeneration will be explored. The nanofiber will contain an aminoglycoside and a glycopeptide, and it is sought to deliver a sustained release of antibiotics for up to 12 weeks. To determine release rate, nanofiber samples are immersed in 10.0 mL of MiliQ water (MQ), incubated at 37°C, assayed at specific time intervals, and then analyzed using ultra performance liquid chromatography in tandem with mass spectrometry. A hydrophilic interaction liquid chromatography (HILIC) method utilizing ultra-performance liquid chromatography (UPLC) in tandem with mass spectrometry (MS) has been developed in order to quantify the release rate of each antibiotic from the nanofiber mesh as a function of time spent in MQ. The antibiotic release rate for six separate permutations of nanofibers was documented. In addition to monitoring drug release as a function of time, mass loss, pH changes, and morphology changes as a function of time have been monitored for an additional three antibiotic-free permutations of nanofiber devices. More specifically, the mass loss profiles for the three permutations of nanofiber devices were generated. To determine mass loss, nanofiber samples are immersed in 10.0 mL of a phosphate buffered saline (PBS), incubated at 37°C, assayed at specific time intervals, and then a final mass was directly compared to the starting mass. Changes in morphology were documented using a scanning electron microscope (SEM). SEM images were taken at weekly intervals and compared to original SEM images characterizing the nanofibers before immersion in PBS

Solid State NMR Relaxation Studies of Triosephosphate Isomerase

Both protein structure and dynamics are essential to understanding biological function. NMR is a powerful technique for the observation of protein dynamics in that dynamics can be observed site-specifically over a wide range of timescales from picoseconds to seconds. Spin relaxation measurements, including relaxation in the rotating frame (R1ρ), can be very sensitive to exchange processes in proteins, particularly on the millisecond-to-microsecond timescale. Using solid state NMR, few techniques exist that can quantify dynamics on this timescale. Previous R1ρ relaxation measurements in the solid state have utilized reorientation of a dipole tensor to observe dynamics. This application is limited to systems where the nucleus of interest has an attached proton. Relaxation studies using the reorientation of a chemical shift tensor are applicable to a broader range of systems. Furthermore, solid state experiments do not require a change in the isotropic chemical shift as is necessary in solution NMR. We combined R1ρ measurements of the model compound dimethyl sulfone (DMS) with data-fitting routines in Spinevolution to show that R1ρ relaxation due to reorientation of a chemical shift tensor is a large effect in the solid state and these measurements can be used to quantify chemical exchange processes. The temperature dependence of the exchange rates determined with R1ρ measurements is in agreement with other measurements of the dynamics of DMS with various solid state NMR techniques. Deuteration and sparse isotropic labeling were necessary to obtain quantitative results. To distinguish the exchange contribution to relaxation from other effects (R2 relaxation), low temperatures and high spin-lock field strengths were utilized. R1ρ experiments and magic angle spinning (MAS) one-dimensional spectra were used to characterize phosphate ligand binding in the glycolytic protein triosephosphate isomerase. 1D spectra indicated the presence of both isotropic and anisotropic phosphate populations. These states included an unbound state with an isotropic chemical shift tensor, and a protein-bound state in which the anisotropic features are reintroduced through chelation with protein backbone amides. The chemical shift anisotropy tensor of the bound phosphate ligand was fit using spinning sideband analysis of slow MAS spectra and suggest the ligand is in a dianionic state. The temperature dependence of R1ρ measurements indicated a fast dynamic process above the microsecond timescale at physiological temperatures

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Country adherence to WHO recommendations to improve the quality of HIV diagnosis: a global policy review.

INTRODUCTION: Ensuring a correct and timely HIV diagnosis is critical. WHO publishes guidelines on HIV testing strategies that maximise the likelihood of correctly determining one's HIV status. A review of national HIV testing policies in 2014 found low adherence to WHO guidelines. We updated this review to determine adherence to current recommendations. METHODS: We conducted a comprehensive policy review through April 2018. We extracted data on HIV testing strategies, recommendations on HIV retesting prior to antiretroviral therapy (ART) initiation and pre-exposure prophylaxis (PrEP)-related HIV testing information. Descriptive analyses disaggregated by region were conducted to ascertain adherence to recommendations and to describe testing strategy characteristics. RESULTS: Of 91 policies included, 26% (n=24/91) adhered to WHO recommendations. Having a two-assay testing strategy to rule-in HIV infection as opposed to the recommended three-assay testing strategy was a major reason for non-adherence. Of 72 country policies providing sufficient information, 31% (n=22) recommended retesting for HIV prior to initiating ART. Of 25 countries and two regions reporting PrEP-related HIV testing guidelines, almost all recommended testing prior to initiating PrEP and every 3 months during PrEP use. CONCLUSIONS: Global adherence to WHO recommendations for HIV testing strategies have improved since 2014 but remain low. We found adherence existed on a continuum. Such a system provides insights into how countries can move towards adherence by making relatively minor changes to testing strategies. Guidance from WHO on the role of new HIV testing technologies within testing algorithms and identifying ways to simplify testing guidance is warranted

Pediatric Responses to Fundamental and Formant Frequency Altered Auditory Feedback: A Scoping Review

Purpose: The ability to hear ourselves speak has been shown to play an important role in the development and maintenance of fluent and coherent speech. Despite this, little is known about the developing speech motor control system throughout childhood, in particular if and how vocal and articulatory control may differ throughout development. A scoping review was undertaken to identify and describe the full range of studies investigating responses to frequency altered auditory feedback in pediatric populations and their contributions to our understanding of the development of auditory feedback control and sensorimotor learning in childhood and adolescence. Method: Relevant studies were identified through a comprehensive search strategy of six academic databases for studies that included (a) real-time perturbation of frequency in auditory input, (b) an analysis of immediate effects on speech, and (c) participants aged 18 years or younger. Results: Twenty-three articles met inclusion criteria. Across studies, there was a wide variety of designs, outcomes and measures used. Manipulations included fundamental frequency (9 studies), formant frequency (12), frequency centroid of fricatives (1), and both fundamental and formant frequencies (1). Study designs included contrasts across childhood, between children and adults, and between typical, pediatric clinical and adult populations. Measures primarily explored acoustic properties of speech responses (latency, magnitude, and variability). Some studies additionally examined the association of these acoustic responses with clinical measures (e.g., stuttering severity and reading ability), and neural measures using electrophysiology and magnetic resonance imaging. Conclusion: Findings indicated that children above 4 years generally compensated in the opposite direction of the manipulation, however, in several cases not as effectively as adults. Overall, results varied greatly due to the broad range of manipulations and designs used, making generalization challenging. Differences found between age groups in the features of the compensatory vocal responses, latency of responses, vocal variability and perceptual abilities, suggest that maturational changes may be occurring in the speech motor control system, affecting the extent to which auditory feedback is used to modify internal sensorimotor representations. Varied findings suggest vocal control develops prior to articulatory control. Future studies with multiple outcome measures, manipulations, and more expansive age ranges are needed to elucidate findings

Who are the missing men? Characterising men who never tested for HIV from population-based surveys in six sub-Saharan African countries.

INTRODUCTION: We sought to characterize men who had never tested for HIV, understand factors associated with not testing, and measure survey HIV test uptake among never testers. We analysed nationally representative Demographic and Health Surveys of six African countries from 2013 to 2016: Ethiopia, Malawi, Zimbabwe, Rwanda, Lesotho and Zambia. METHODS: Eligible men were household residents or overnight visitors aged 15 to 59 years. We analysed questionnaire responses on HIV testing, known behavioural risk factors, and corresponding HIV laboratory results. We used survey-weighted logistic regression to identify factors associated with never testing for HIV. RESULTS: Approximately double the proportion of men had never tested for HIV compared to women (Malawi: 30% vs. 17%, p < 0.0001; Zimbabwe: 35% vs. 19%, p < 0.0001; Lesotho: 34% vs. 15%, p < 0.0001; Zambia: 36% vs. 20%, p < 0.0001); although, less of a differential existed in Ethiopia (54% vs. 56%, p = 0.12) and Rwanda (19% vs. 14%, p < 0.0001). When offered a test during the survey, 85% to 99% of sexually active men who reported never previously testing, accepted testing. HIV positivity ranged from <0.05% to 14% for never tested men. After adjusting for age, factors associated with never having tested for HIV were never being married (aOR range: 1.46 to 10.39), not having children (aOR: 1.36 to 3.59) and lower education (less than primary education aOR: 2.77 to 5.59). CONCLUSIONS: Although higher proportions of men than women had never tested for HIV, 85% to 99% of men did accept a test when offered. Finding opportunities to offer HIV testing to single men without children, older men who have never tested, and those disadvantaged with less schooling and employment, alongside other facility and community-based services, will be important in identifying those living with undiagnosed HIV and improving men's health

Patient acceptance of HIV testing services in rural emergency departments in South Africa

Background: South Africa faces the highest burden of HIV infection globally. The National Strategic Plan on HIV recommends provider-initiated HIV counselling and testing (HCT) in all healthcare facilities. However, HIV continues to overwhelm the healthcare system. Emergency department (ED)-based HCT could address unmet testing needs. Objectives: This study examines the reasons for accepting or declining HCT in South African EDs to inform the development of HCT implementation strategies. Method: We conducted a prospective observational study in two rural EDs, from June to September 2017. Patients presenting to the ED were systematically approached and offered a point-of-care test in accordance with national guidelines. Patients demographics, presenting compaint, medical history and reasons for accepting/declining testing, were recorded. A pooled analysis is presented. Results: Across sites, 2074 adult, non-critical patients in the ED were approached; 1880 were enrolled in the study. Of those enrolled, 19.7% had a previously known positive diagnosis, and 80.3% were unaware of their HIV status. Of those unaware, 90% patients accepted and 10% declined testing. The primary reasons for declining testing were ‘does not want to know status’ (37.6%), ‘in too much pain’ (34%) and ‘does not believe they are at risk’ (19.9%). Conclusions: Despite national guidelines, a high proportion of individuals remain undiagnosed, of which a majority are young men. Our study demonstrated high patient acceptance of ED-based HCT. There is a need for investment and innovation regarding effective pain management and confidential service delivery to address patient barriers. Findings support a routine, non-targeted HCT strategy in EDs. Keywords: HIV counselling and testing; South Africa; emergency department; patient acceptance; implementation research; linkage to care

Early Neolithic Pits at Principal Place, Shoreditch, London Borough of Hackney

A group of four pits excavated in the upper Walbrook valley at Principal Place, Shoreditch by MOLA in 2015 produced the largest assemblage of Early Neolithic Bowl pottery recovered to date from the City of London and its immediate surrounds. The Neolithic pits had been fortuitously preserved within part of the northern extramural Roman cemetery of Londinium and conjoining sherds of Bowl pottery were also recovered from the fill of an isolated late Roman cremation. A range of analyses showed that the vessels – comprising essentially Plain Bowl with some Decorated Bowl, the latter incorporating Peterborough Ware traits – were probably locally made and had been used to process dairy products and to stew beef and mutton (though not pork). Radiocarbon dating of the lipids absorbed within the vessel walls – employing a novel technique developed at the University of Bristol – suggest that the pottery was being used in the mid-fourth millennium cal BC. The pits also contained small assemblages of struck flint, fauna (some burnt) and archaeobotanical remains (some intrusive) and may have been filled using material drawn from a long-vanished ‘pre-pit’ source, possibly a midden; they presumably represent episodic activity on the part of semi-sedentary Neolithic communities

Use and awareness of and willingness to self-test for HIV: an analysis of cross-sectional population-based surveys in Malawi and Zimbabwe.

BACKGROUND: Many southern African countries are nearing the global goal of diagnosing 90% of people with HIV by 2020. In 2016, 84 and 86% of people with HIV knew their status in Malawi and Zimbabwe, respectively. However, gaps remain, particularly among men. We investigated awareness and use of, and willingness to self-test for HIV and explored sociodemographic associations before large-scale implementation. METHODS: We pooled responses from two of the first cross-sectional Demographic and Health Surveys to include HIV self-testing (HIVST) questions in Malawi and Zimbabwe in 2015-16. We investigated sociodemographic factors and sexual risk behaviours associated with previously testing for HIV, and past use, awareness of, and future willingness to self-test using univariable and multivariable logistic regression, adjusting for the sample design and limiting analysis to participants with a completed questionnaire and valid HIV test result. We restricted analysis of willingness to self-test to Zimbabwean men, as women and Malawians were not systematically asked this question. RESULTS: Of 31,385 individuals, 31.2% of men had never tested compared with 16.5% of women (p < 0.001). For men, the likelihood of having ever tested increased with age. Past use and awareness of HIVST was very low, 1.2 and 12.6%, respectively. Awareness was lower among women than men (9.1% vs 15.3%, adjusted odds ratio [aOR] = 1.55; 95% confidence interval [CI]: 1.37-1.75), and at younger ages, and lower education and literacy levels. Willingness to self-test among Zimbabwean men was high (84.5%), with greater willingness associated with having previously tested for HIV, being at high sexual risk (highest willingness [aOR = 3.74; 95%CI: 1.39-10.03, p < 0.009]), and being ≥25 years old. Wealthier men had greater awareness of HIVST than poorer men (p < 0.001). The highest willingness to self-test (aOR = 3.74; 95%CI: 1.39-10.03, p < 0.009) was among men at high HIV-related sexual risk. CONCLUSIONS: In 2015-16, many Malawian and Zimbabwean men had never tested for HIV. Despite low awareness and minimal HIVST experience, willingness to self-test was high among Zimbabwean men, especially older men with moderate-to-high HIV-related sexual risk. These data provide a valuable baseline against which to investigate population-level uptake of HIVST as programmes scale up. Programmes introducing, or planning to introduce, HIVST should consider including relevant questions in population-based surveys