Electrochemical deposition of amorphous aluminum oxides on lead pipes to prevent lead leaching into the drinking water.

Over 5000 public drinking water systems in the US are out of compliance with the Lead and Copper Rule. Lead leaching from lead pipes is limited by the solubility of a naturally occurring scale. Changes in water quality may cause this scale to become more soluble, releasing lead into the drinking water. We propose a novel electrochemical method to prevent lead leaching from lead pipes. In this method, an aluminum wire and an alkaline phosphate electrolyte are inserted into the pipes. The pipes are then anodized for 2 h by using an external power supply, resulting in the electrodeposition of an insoluble aluminum oxide layer on top of the preexisting scale. This technology was tested on lead pipes from the EBMUD water distribution systems located in Berkeley, CA, using recirculating synthetic and actual tap water for 120 days. The untreated pipes leached an average of 23 ppb and 38 ppb of lead respectively, when using free chlorine and monochloramine as disinfection residuals. In contrast, the treated pipes leached 3 ppb and 5 ppb respectively. These results suggest that the proposed treatment has the potential to prevent lead leaching regardless of the disinfection residual and thus should be further explored in a field trial.

Identifying schools at high-risk for elevated lead in drinking water using only publicly available data.

Estimating the risk of lead contamination of schools' drinking water at the State level is a complex, important, and unexplored challenge. Variable water quality among water systems and changes in water chemistry during distribution affect lead dissolution rates from pipes and fittings. In addition, the locations of lead-bearing plumbing materials are uncertain. We tested the capability of six machine learning models to predict the likelihood of lead contamination of drinking water at the schools' taps using only publicly available datasets. The predictive features used in the models correspond to those with a proven correlation to the dominant, but commonly unavailable, factors that govern lead leaching: the presence of lead-bearing plumbing materials and water quality conducive to lead corrosion. By combining water chemistry data from public reports, socioeconomic information from the US census, and spatial features using Geographic Information Systems, we trained and tested models to estimate the likelihood of lead contaminated tap water in over 8,000 schools across California and Massachusetts. Our best-performing model was a Random Forest, with a 10-fold cross validation score of 0.88 for Massachusetts and 0.78 for California using the average Area Under the Receiver Operating Characteristic Curve (ROC AUC) metric. The model was then used to assign a lead leaching risk category to half of the schools across California (the other half was used for training). There was good agreement between the modeled risk categories and the actual lead leaching outcomes for every school; however, the model overestimated the lead leaching risk in up to 17% of the schools. This model is the first of its kind to offer a tool to predict the risk of lead leaching in schools at the State level. Further use of this model can help deploy limited resources more effectively to prevent childhood lead exposure from school drinking water.

Predicting childhood lead exposure at an aggregated level using machine learning.

Childhood lead exposure affects over 500,000 children under 6 years old in the US; however, only 14 states recommend regular universal blood screening. Several studies have reported on the use of predictive models to estimate lead exposure of individual children, albeit with limited success: lead exposure can vary greatly among individuals, individual data is not easily accessible, and models trained in one location do not always perform well in another. We report on a novel approach that uses machine learning to accurately predict elevated Blood Lead Levels (BLLs) in large groups of children, using aggregated data. To that end, we used publicly available zip code and city/town BLL data from the states of New York (n = 1642, excluding New York City) and Massachusetts (n = 352), respectively. Five machine learning models were used to predict childhood lead exposure by using socioeconomic, housing, and water quality predictive features. The best-performing model was a Random Forest, with a 10-fold cross validation ROC AUC score of 0.91 and 0.85 for the Massachusetts and New York datasets, respectively. The model was then tested with New York City data and the results compared to measured BLLs at a borough level. The model yielded predictions in excellent agreement with measured data: at a city level it predicted elevated BLL rates of 1.72% for the children in New York City, which is close to the measured value of 1.73%. Predictive models, such as the one presented here, have the potential to help identify geographical hotspots with significantly large occurrence of elevated lead blood levels in children so that limited resources may be deployed to those who are most at risk.

Is quality of life after mastectomy comparable to that after breast conservation surgery? A 5-year follow up study from Mumbai, India.

PURPOSE: Breast cancer is the commonest cancer in women worldwide. Surgery is a central part of the treatment. Modified radical mastectomy (MRM) is often replaced by breast conserving therapy (BCT) in high-income countries. MRM is still the standard choice, in low- and middle-income countries (LMICs) as radiotherapy, a mandatory component of BCT is not widely available. It is important to understand whether quality of life (QOL) after MRM is comparable to that after BCT. This has not been studied well in LMICs. We present, 5-year follow-up of QOL scores in breast cancer patients from India. METHODS: We interviewed women undergoing breast cancer surgery preoperatively, at 6 months after surgery, and at 1 year and 5 years, postoperatively. QOL scores were evaluated using FACT B questionnaire. Average QOL scores of women undergoing BCT were compared with those undergoing MRM. Total scores, domain scores and trends of scores over time were analyzed. RESULTS: We interviewed 54 women with a mean age of 53 years (SD 9 ± years). QOL scores in all the women, dipped during the treatment period, in all subscales but improved thereafter and even surpassed the baseline in physical, emotional and breast-specific domains (p < 0.05) at 5 years. At the end of 5 years, there was no statistically significant difference between the MRM and BCT groups in any of the total or domain scores. CONCLUSION: QOL scores in Indian women did not differ significantly between MRM and BCT in the long term. Both options are acceptable in the study setting.

A low cost, re-usable electricity-free infant warmer: evaluation of safety, effectiveness and feasibiliy.

Setting: Rural Rwandan hospitals, where thermoregulation is critical yet a challenge for pre-term, low-birth-weight (LBW) or sick newborns. Objective: To assess the safety, effectiveness, and feasibility of an inexpensive, reusable, non-electric warmer to complement kangaroo mother care (KMC). Methods: Prospective single-arm, non-randomized intervention study. Enrolled infants were hypothermic or at risk of hypothermia due to prematurity/LBW. Infants used the warmer in conjunction with KMC or as the sole source of external heat. Temperatures of the infant, warmer and air were measured for up to 6 h. Results: Overall, 33 patients used the warmer for 102 encounters: 43 hypothermic and 59 at risk of hypothermia. In 7/102 encounters (7%), the infant developed a temperature of >37.5°C (37.6°-38.2°C). For 43 hypothermic encounters and 59 at-risk encounters, hypothermia was corrected/prevented in respectively 41 (95%) and 59 (100%) instances. The warmer maintained goal temperature for the study duration in ⩾85% of uses. Two/12 warmers broke down after <10 uses. In no instances was the warmer used incorrectly. Conclusion: Our results are promising for this prototype design, and warrant testing on a wider scale.

Contexte : Des hôpitaux ruraux du Rwanda où la thermorégulation est cruciale mais complexe pour les nouveaux-nés prématurés, de faible poids de naissance (LBW) ou malades.Objectif : Evaluer la sécurité, l'efficacité et la faisabilité d'un réchauffeur peu coûteux, réutilisable et non électrique pour compléter la méthode kangourou (KMC).Méthode : Etude rétrospective d'intervention à un seul bras, non randomisée. Les nouveaux-nés enrôlés étaient en hypothermie ou à risque d'hypothermie liée à la prématurité ou au LBW. Les nouveaux-nés ont bénéficié du réchauffeur en conjonction avec la méthode KMC ou comme source unique de chaleur externe. Les températures des bébés, du réchauffeur et de l'air ont été mesurées pendant 6 h.Résultats : Ont bénéficié du réchauffeur 33 patients pour un total de 102 utilisations ; 43 étaient en hypothermie et 59 à risque d'hypothermie. Dans 7/102 utilisations (7%), le bébé a atteint une température de >37,5°C (37,6°­38,2°C). Dans 43 cas d'hypothermie et 59 cas à risque, l'hypothermie a été corrigée/prévenue dans 41 (95%) et 59 (100%) instances, respectivement. Le réchauffeur a maintenu la température souhaitée pendant la durée de l'étude dans ≥85% des utilisations. Deux réchauffeurs sur 12 ont été hors d'usage après moins de 10 utilisations. Il n'y a jamais eu d'utilisation incorrecte.Conclusion : Nos résultats sont prometteurs en ce qui concerne la conception de ce prototype et ils justifient une évaluation à plus grande échelle.

Marco de Referencia: En varios hospitales rurales de Rwanda, la termorregulación que es fundamental para los recién nacidos con bajo peso al nacer o enfermos, plantea dificultades.Objetivo: Evaluar la seguridad, la eficacia y la factibilidad de un dispositivo no eléctrico, de bajo costo y reutilizable que genera calor como complemento al método de la madre canguro (KMC).Métodos: Fue este un estudio prospectivo de intervención con un solo grupo, no aleatorizado. Se incluyeron lactantes que ya sea, estaban hipotérmicos o expuestos a la hipotermia debido a su prematuridad o el bajo peso al nacer. Con estos lactantes, se utilizó el calentador como fuente externa exclusiva de calor o en asociación con el KMC. Se midieron las temperaturas del lactante, el calentador y la temperatura ambiente durante un máximo de 6 h.Resultados: Se utilizó el dispositivo en 102 encuentros con 33 pacientes, de los cuales 43 estaban hipotérmicos y 59 estaban en riesgo de entrar en hipotermia. En siete de los 102 encuentros (7%), el lactante alcanzó una temperatura superior a 37,5°C (37,6°­38,2°C). La hipotermia se corrigió en 41 de los 43 encuentros con lactantes hipotérmicos (95%) y se evitó en 59 de las 59 ocasiones con bebés expuestos (100%). El calentador mantuvo la temperatura buscada durante todo el estudio en ≥85% de los encuentros en los cuales se utilizó. Dos de los 12 dispositivos exhibieron degradación después de menos de 10 utilizaciones. En ningún caso se utilizó el calentador de manera incorrecta.Conclusión: Los resultados obtenidos con este método prototipo son promisorios y se justifica realizar un ensayo clínico de mayor escala.

Molded arthrodesis of the hallux metatarsophalangeal joint using the crossed-screw technique: surgical technique, results and functional outcomes.

BACKGROUND: We describe the surgical technique, results and functional outcomes of molded arthrodesis of hallux metatarsophalangeal (MTP) joint using crossed-screw fixation. METHODS: 23 Toes in 21 consecutive patients operated between September 2007 and January 2010 were included for the retrospective study. Average age was 60.0 years (range 31-84 years) with male female ratio being 3:4. Differential pitch cannulated crossed screw technique was used in all cases. At the latest follow-up, the radiological findings, the hallux-forefoot AOFAS scores and patient satisfaction questionnaires were used to assess outcomes. RESULTS: Overall fusion rate was 91% with a mean hallux valgus angle of 13.6° (range 8-22°) and a mean dorsi-flexion angle of 25° (range 18-30°). Complication rate was 13% that included two superficial wound infections and one failed fusion that underwent a successful fusion after revision surgery. At a mean follow-up of 17 months (range 6-34 months), the mean AOFAS score was 79 (out of a maximum of 90). 92% of the patients were satisfied with the final outcome and 83% mentioned that they would have the procedure again. CONCLUSIONS: Crossed-screw technique of arthrodesis of the first MTP joint is successful for relief of pain, allowing a high level of function and good patient satisfaction.

Nutcracker fracture of the cuboid: a case report.

Nutcracker fracture of the cuboid is a rare injury usually caused by forced abduction of the forefoot on a fixed hindfoot. We report a case of this fracture in a 58-year-old man who was treated on the principle of ligamentotaxis and the position being held with Kirchner wires for a period of 5 weeks. He recovered without any complications and with good ankle and subtalar movements. At 5 months following the injury he had returned to his previous occupation. We think this novel way of treating this rare fracture is simple and gave a good result in this patient.

Elevated, straight-arm traction for supracondylar fractures of the humerus in children.

Between January 1995 and December 2000, 112 children with a closed displaced supracondylar fracture of the humerus without vascular deficit, were managed by elevated, straight-arm traction for a mean of 22 days. The final outcome was assessed using clinical (flexion-extension arc, carrying angle and residual rotational deformity) and radiographic (metaphyseal-diaphyseal angle and humerocapitellar angle) criteria. Excellent results were achieved in 71 (63%) patients, 33 (29%) had good results, 5 (4.4%) fair, and 3 (2.6%) poor. All patients with fair or poor outcomes were older than ten years of age. Elevated, straight-arm traction is safe and effective in children younger than ten years. It can be effectively used in an environment that can provide ordinary paediatric medical care and general orthopaedic expertise. The outcomes compare with supracondylar fractures treated surgically in specialist centres.

Pollutant dispersion in a large indoor space. Part 2: Computational fluid dynamics predictions and comparison with a scale model experiment for isothermal flow.

UNLABELLED: This paper reports on an investigation of the adequacy of computational fluid dynamics (CFD), using a standard Reynolds Averaged Navier-Stokes (RANS) model, for predicting dispersion of neutrally buoyant gas in a large indoor space. We used CFD to predict pollutant (dye) concentration distribution in a water-filled scale model of an atrium with a continuous pollutant source in the absence of furniture and occupants. Predictions from the RANS formulation are comparable with an ensemble average of independent identical experiments. Model results were compared with pollutant concentration data in a horizontal plane from experiments in a scale model atrium. Predictions were made for steady-state (fully developed) and transient (developing) pollutant concentrations. Agreement between CFD predictions and ensemble averaged experimental measurements is quantified using the ratios of CFD-predicted and experimentally measured dye concentration at a large number of points in the measurement plane. Agreement is considered good if these ratios fall between 0.5 and 2.0 at all points in the plane. The standard k-epsilon two-equation turbulence model obtains this level of agreement and predicts pollutant arrival time to the measurement plane within a few seconds. These results suggest that this modeling approach is adequate for predicting isothermal pollutant transport in a large room with simple geometry. PRACTICAL IMPLICATIONS: CFD modeling of pollutant transport is becoming increasingly common but high quality comparisons between CFD and experiment remain rare. Our results provide such a comparison. We demonstrate that the standard k-epsilon model provides good predictions for both transient and fully developed pollutant concentrations for an isothermal large space where furnishings are unimportant. This model is less computationally intensive than a large eddy simulation or low Reynolds number k-epsilon model.

Street-level concentrations of suspended particulate matter (SPM), nitrogen dioxide (NO2) and sulphur dioxide (SO2) in Pune City.

The concentration of suspended particulate matter (SPM), nitrogen dioxide (NO,) and sulphur dioxide (SO2) were measured at 13 important traffic intersections in Pune city. In order to study the contribution of these pollutants from motor vehicles, attention was focused on the roadside, street-level concentration. The statistical analysis of the sampling results indicates that there is not only high correlation between SPM and NO2 but the levels of these pollutants are above the National Ambient Air Quality Standards (NAAQS) laid down by the Central Pollution Control Board (CPCB), India. The SO, concentrations are found to be well below the NAAQS.

Infective discitis with Neisseria sicca/subflava in a previously healthy adult.

STUDY DESIGN: A case report of Neisseria sicca/subflava discitis in a healthy elderly female. OBJECTIVE: To report a rare case, which is usually seen exclusively in children. SETTING: Stoke on Trent, England. METHOD: Case report, a 65-year-old female with a 6 month history of back and bilateral leg pain. X-rays showed collapse of L4/5 disc. No neurological deficit. Magnetic resonance imaging supported the clinical suspicion of discitis. Percutaneous biopsy followed 2 weeks later by open biopsy with bilateral root decompression was performed. Culture of L4/5 disc tissue produced Neisseria sicca/subflava. The patient was treated with a 4-week course of intravenous amoxycillin. Follow-up at 3 months confirmed clinical resolution of original symptoms. CONCLUSION: Any organism cultured from biopsy needs to be interpreted within the context of the clinical case. If clinical suspicion is high, further weight must be added to the finding of unusual or environmental organisms and culture of a repeat aspirate or biopsy may clarify the significance.

Responding to sudden pollutant releases in office buildings: 1. Framework and analysis tools.

We describe a framework for developing response recommendations to unexpected toxic pollutant releases in commercial buildings. It may be applied in conditions where limited building- and event-specific information is available. The framework is based on a screening-level methodology to develop insights, or rules-of-thumb, into the behavior of airflow and pollutant transport. A three-stage framework is presented: (1). develop a building taxonomy to identify generic, or prototypical, building configurations; (2). characterize uncertainty and conduct simulation modeling to predict typical airflow and pollutant transport behavior; and (3). rank uncertainty contributions to determine how information obtained at a site might reduce uncertainties in the model predictions. The approach is applied to study a hypothetical pollutant release on the first floor of a five-story office building. Key features that affect pollutant transport are identified and described by value ranges in the building stock. Simulation modeling provides predictions and uncertainty estimates of time-dependent pollutant concentrations, following a release, for a range of indoor and outdoor conditions. In this exercise, we predict concentrations on the fifth floor to be an order of magnitude less than on the first, coefficients of variation greater than 2, and information about the HVAC operation and window position most reducing uncertainty in predicted peak concentrations.

Comparing zonal and CFD model predictions of isothermal indoor airflows to experimental data.

It is inappropriate to use the assumption of instantaneously well-mixed zones to model airflows and pollutant transport in large indoor spaces. We investigate two approaches for describing the details of airflows in large indoor spaces, for accuracy and suitability for integration with multi-zone infiltration models. One approach, called the zonal method, was developed over the last 15 years to provide an improvement over the well-mixed assumption. The second approach is the use of a computational fluid dynamics simulation using a coarse grid model of the large indoor space. We compare velocity predictions from different formulations of zonal methods and coarse-grid k-epsilon computational fluid dynamics (CFD) models, to measurements, in a 2D mechanically ventilated isothermal room. Our results suggest that, when airflow details are required, coarse-grid CFD is a better-suited method to predict airflows in large indoor spaces coupled with complex multi-zone buildings, than are the zonal methods. Based on the comparison of pressure predictions from different models, we offer guidance regarding the coupling of a model of detailed airflow in large spaces to algebraic multi-zone infiltration models.

Isolated avulsion fracture of the coronoid process requiring open reduction in a paediatric patient: a case report.

Coronoid process fractures are reported to occur from avulsion by the brachialis muscle or to be associated with elbow dislocations. We report a rare case of coronoid process fracture due to avulsion by the anterior bundle of the medial collateral ligament rendering the elbow unstable. In children, small fracture fragments of the coronoid process (types 1 & 2) are in reality often much larger but the actual size is not appreciated radiographically, as the coronoid process contains considerable amounts of cartilage. If the fragment is seen to be significantly displaced it may have resulted from avulsion by important structures such as the medial collateral ligament and open reduction is required to stabilise the elbow.

A study of the mechanical stability of scoliosis constructs using variable numbers of sublaminar wires.

Sublaminar wiring with posterior instrumentation is one of the methods used when long fusions involving 10-12 thoracolumbar levels are required. Classically, wires are used at every consecutive level to make the construct as rigid as possible, although complications like dural tears, cerebrospinal fluid leak, and neurological deficit have been reported during their passage. We compared the mechanical stability under torsional strain of five specimens of each of three construct designs, by static and fatigue testing, using an electro-servo-hydraulic testing machine. In construct A, a contoured Hartshill rectangle was used from T2 to L2, with sublaminar wires passed at every level. In construct B, the Hartshill rectangle was wired to the spine at every alternate level. In construct C, every alternate level was wired except at the proximal end, where two consecutive levels were wired. Industrially fabricated spine models were used to prepare these constructs. The intervertebral motion within the construct was measured using the Fastrak magnetic field sensor device. On static testing, no statistically significant difference was found in the rotational displacement of the three construct designs. On fatigue testing, all samples of construct B consistently failed, with breakage of the wire at the most proximal level on the left side. But on adding additional wires to the next level (construct C), all five samples withstood fatigue testing at 300 N load to three million cycles. We conclude that wiring alternate levels instead of every level does not compromise the stability of the construct, provided that the most proximal two levels are consecutively wired. This practice would minimise the risk of dural tears and cord damage during wire passage and reduce surgical time, not to mention the economic benefits.

Cryptosporidium inactivation by low-pressure UV in a water disinfection device.

Using animal infectivity tests, the authors evaluated a water disinfection device, UV Waterworks (UVW), for its ability to inactivate Cryptosporidium parvum oocysts. The UVW employs low-pressure, germicidal ultraviolet (UV) light, delivering a dose of approximately 120 millijoules per square centimeter (mJ/cm2) under ideal water conditions at a flow rate of 4 gallons per minute (gpm). Dechlorinated tap water containing live oocysts was passed through the UVW at 4 gpm. The oocysts were captured on a filter, separated from the filter, and concentrated into inocula--10 microliters (microL) each, containing between 10(3) and 10(7) oocysts--which were administered orally into 60 neonatal mice. After one week, the mice were killed, and sections of their terminal ilea were analyzed microscopically for signs of Cryptosporidium infection. In spite of the high dose of oocysts, none of the mice showed signs of infection. A process control run with the UV lamp off resulted in 95 percent infection at a dose of 10(3) oocysts per inoculum. The calculated reduction in oocyst infectivity from passage through UV Waterworks was at least 5.4 orders of magnitude. The authors conclude that exposure to low-pressure UV at 120 mJ/cm2 effectively disables Cryptosporidium.

Hygroscopic fine mode particle deposition on electronic circuits and resulting degradation of circuit performance: an experimental study.

A portion of electronic equipment failures is a consequence of particle deposition on electronic circuits in normal indoor environments. Deposited hygroscopic particles reduce the electrical isolation (EI) between conductors. In laboratory experiments, we investigated the mechanisms, locations, and effects of particle deposition on electronic circuits with surface mounted chips (SMCs) and also on small television sets. One set of electronics was exposed for 281 h to an unusually high concentration of artificially-generated ammonium sulfate particles while a second set (experimental controls) was exposed to normal indoor particles. The particle mass concentration in the high-exposure chamber was 500 times higher than normal. Television reliability was observed and the changes in EI between adjacent legs of SMCs were measured. The experiments demonstrate the strong influence of electrostatic forces on the locations and rates of particle deposition. Although televisions did not fail after exposure to concentrated aerosols, the EI between adjacent legs of the SMCs was, in many cases, greatly diminished. Relative humidity had a very strong influence on the magnitude of EI. A qualitative explanation of the mechanisms of particle deposition and circuit degradation is proposed, including the role of fibers. Finally, a potential method to reduce particle deposition on electronic components is discussed.

Effectiveness of smokeless ashtrays.

Most environmental tobacco smoke (ETS) issues from the tips of smoldering cigarettes between puffs. Smokeless ashtrays are designed to reduce ETS exposure by removing particulate and/or gas-phase contaminants from this plume. This paper describes an experimental investigation of the effectiveness of four smokeless ashtrays: two commercial devices and two prototypes constructed by the authors. In the basic experimental protocol, one or more cigarettes was permitted to smolder in a room. Particulate or gas-phase pollutant concentrations were measured in the room air over time. Device effectiveness was determined by comparing pollutant concentrations with the device in use to those obtained with no control device. A lung deposition model was applied to further interpret device effectiveness for particle removal. The commercial ashtrays were found to be substantially ineffective in removing ETS particles because of the use of low-quality filter media and/or the failure to draw the smoke through the filter. A prototype ashtray using HEPA filter material achieved better than 90% particle removal efficiency. Gas-phase pollutant removal was tested for only one prototype smokeless ashtray, which employed filters containing activated carbon and activated alumina. Removal efficiencies for the 18 gas-phase compounds measured (above the detection limit) were in the range of 70 to 95%.