Disparities in occupational health services: an international comparative study.

BACKGROUND: Occupational Health Services (OHS) are comprehensive, multidisciplinary services supplied by various trained workers, including occupational physicians (OP), whose specialty is focused on workers' health. AIMS: Our study questions are whether the OP/worker ratio may reflect the scope and availability of OHS. METHODS: This comparative study, conducted on globally different OHS, was based on literature analysis of peer-reviewed articles published in journals covering topics of occupational medicine and public health that addressed parameters on the type and scope of OHS provision. RESULTS: We described the number of OP/worker ratio, and the correlation to economic parameters (Gross domestic product-GDP, health expenditure, Gini Index-GI) by country. We found that among countries with a GDP per capita higher than US$30,000, only three (US, South Korea and Israel) had a very low OP/worker ratio (about 1:50,000 compared to 1:5,000 in other countries). Looking at all the countries together, there was a statistically significant negative correlation between health expenditure percentage of GDP per capita and OP/worker ratio (rs = -0.54, p = 0.01) and a significant positive correlation between GI and OP/worker ratio (rs = 0.47, p = 0.04). CONCLUSIONS: The lesser the percentage of health expenditure of GDP and the subsequent greater general inequality as reflected by the GI, the lower the OP/worker ratio. The data collected in our comparative study show that the OP/worker ratio is a parameter both easy to define and obtain which best represents the status and disparity of OHS in each country.

Pilot Evaluations of Two Bluetooth Contact Tracing Approaches on a University Campus: Mixed Methods Study.

BACKGROUND: Many have proposed the use of Bluetooth technology to help scale up contact tracing for COVID-19. However, much remains unknown about the accuracy of this technology in real-world settings, the attitudes of potential users, and the differences between delivery formats (mobile app vs carriable or wearable devices). OBJECTIVE: We pilot tested 2 separate Bluetooth contact tracing technologies on a university campus to evaluate their sensitivity and specificity, and to learn from the experiences of the participants. METHODS: We used a convergent mixed methods study design, and participants included graduate students and researchers working on a university campus during June and July 2020. We conducted separate 2-week pilot studies for each Bluetooth technology. The first was for a mobile phone app ("app pilot"), and the second was for a small electronic "tag" ("tag pilot"). Participants validated a list of Bluetooth-identified contacts daily and reported additional close contacts not identified by Bluetooth. We used these data to estimate sensitivity and specificity. Participants completed a postparticipation survey regarding appropriateness, usability, acceptability, and adherence, and provided additional feedback via free text. We used tests of proportions to evaluate differences in survey responses between participants from each pilot, paired t tests to measure differences between compatible survey questions, and qualitative analysis to evaluate the survey's free-text responses. RESULTS: Among 25 participants in the app pilot, 53 contact interactions were identified by Bluetooth and an additional 61 by self-report. Among 17 participants in the tag pilot, 171 contact interactions were identified by Bluetooth and an additional 4 by self-report. The tag had significantly higher sensitivity compared with the app (46/49, 94% vs 35/61, 57%; P<.001), as well as higher specificity (120/126, 95% vs 123/141, 87%; P=.02). Most participants felt that Bluetooth contact tracing was appropriate on campus (26/32, 81%), while significantly fewer participants felt that using other technologies, such as GPS or Wi-Fi, was appropriate (17/31, 55%; P=.02). Most participants preferred technology developed and managed by the university rather than a third party (27/32, 84%) and preferred not to have tracing apps on their personal phones (21/32, 66%), due to "concerns with privacy." There were no significant differences in self-reported adherence rates across pilots. CONCLUSIONS: Convenient and carriable Bluetooth technology may improve tracing efficiency while alleviating privacy concerns by shifting data collection away from personal devices. With accuracy comparable to, and in this case, superior to, mobile phone apps, such approaches may be suitable for workplace or school settings with the ability to purchase and maintain physical devices.

Small-angle neutron scattering studies of mineralization on BSA coated citrate capped gold nanoparticles used as a model surface for membrane scaling in RO wastewater desalination.

Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 µm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs.

Correcting for spatial-resolution degradation mechanisms in OFDR via inline auxiliary points.

The spatial resolution of OFDR is normally degraded by the laser phase noise, deviations from linear frequency scan and acoustic noise in the fibers. A method for mitigating these degradation mechanisms, without using an auxiliary interferometer, via inline auxiliary points, is presented and demonstrated experimentally. Auxiliary points are points that are a priori known to have (spatial) impulse reflectivities. Their responses are used for compensating the phase deviations that degrade the response of points that are further away from the source.

Transport properties of highly ordered heterogeneous ion-exchange membranes.

Model "ordered" heterogeneous ion exchange membranes are made with ion exchange particles heaving ion exchange capacity in the range 3 to 2.5 meq/gr (dry basis) and diameters ranging from 37 to 7 microm and 2 component room-temperature vulcanizing silicon rubber as a polymeric matrix, by applying an electric field normal to the membrane surface during preparation. These membranes were shown to have an improved ionic conductivity compared with "nonordered" membranes based on the same ion exchange content (for instance, at 10% resin content "nonordered" membranes show <10(-5) mS/cm while "ordered" membranes have conductivity of 1 mS/cm). The transport properties of ordered membranes were compared with those of nonordered membranes, through the current-voltage characteristics. Limiting currents measured for the ordered membranes were significantly higher than those of the nonordered membranes with the same resin concentration. In addition, higher limiting currents were observed in ordered membranes as the resin particles became smaller. Energy dispersion spectrometry analyses revealed that the concentration of cation exchange groups on the membrane surface was higher for ordered membrane as compared to that of nonordered membranes. This implies that the local current density for the conducting domains at the surface of the nonordered membranes is higher, leading to higher concentration polarization and, eventually, to lower average limiting current densities. The effect of ordering the particles on the membrane conductivity and transport properties was studied, and the advantages of the ordered membranes are discussed.

Semimembranosus tenosynovitis: operative results.

Semimembranosus tenosynovitis is a common knee problem in the over-50 age-group, occurring mainly in women. It affects the reflected portion of the tendon of the semimembranosus muscle as well as the bursa below it. The tendon becomes inflamed as a result of friction at the entrance to the bony canal (semimembranosus groove), especially if osteophytes are present on the edges of the groove. Conservative treatment includes anti-inflammatory drugs, ultrasound, and friction massage. If necessary, nonresponders may be given local injection of 40-80 mg methylprednisolone acetate with 1% Xylocaine. Between 1979 and 1983 we operated on 16 patients who had not obtained relief even after three or four injections. The approach in each case was through a posterior medial oblique incision. The semimembranosus osteofibrotic tunnel was revealed and the fibrous sheath surrounding the tendon was excised. Good results were obtained in eight patients in whom the inflammatory process had been localized to only the semimembranosus insertion area: eight patients in whom the knee joint or the pes anserinus insertion was also involved achieved fair or poor results. The operation is not advised for young athletes because of the important function of the reflected head of the semimembranosus muscle.