Gratitude and kindness at work as predictors of employees' mental health outcomes during the COVID-19 pandemic.

This research explored the association of perceptions of gratitude and kindness at work with well-being outcomes, such as relatedness needs satisfaction, life satisfaction, and COVID-19 anxiety among selected Filipino employees during the COVID-19 pandemic. Hierarchical regression analyses demonstrated that kindness positively predicted relatedness needs satisfaction even after controlling for participants' age, gender, employment status, and length of stay in the organization. Gratitude positively predicted life satisfaction. This research underscores the mental health payoffs associated with fostering gratitude and kindness in organizational contexts during the COVID-19 pandemic.

Understanding the Role and Value of Process Quality Indicators in Older Vascular Surgery Inpatients.

BACKGROUND: Despite the development of geriatrics surgery process quality indicators (QIs), few studies have reported on these QIs in routine surgical practice. Even less is known about the links between these QIs and clinical outcomes, and patient characteristics. We aimed to measure geriatrics surgery process QIs, and investigate the association between process QIs and outcomes, and QIs and patient characteristics, in hospitalized older vascular surgery patients. METHODS: This was a prospective cohort study of 150 consecutive patients aged ≥ 65 years admitted to a tertiary vascular surgery unit. Occurrence of geriatrics surgery process QIs as part of routine vascular surgery care was measured. Associations between QIs and high-risk patient characteristics, and QIs and clinical outcomes were assessed using clustered heatmaps. RESULTS: QI occurrence rate varied substantially from 2% to 93%. Some QIs, such as cognition and delirium screening, documented treatment preferences, and geriatrician consultation were infrequent and clustered with high-risk patient characteristcs. There were two major process-outcome clusters: (a) multidisciplinary consultations, communication and screening-based process QIs with multiple adverse outcomes, and (b) documentation and prescribing-related QIs with fewer adverse outcomes. CONCLUSIONS: Clustering patterns of process QIs with clinical outcomes are complex, and there is a differential occurrence of QIs by patient characteristics. Prospective intervention studies that report on implemented QIs, outcomes and patient characteristics are needed to better understand the causal pathways between process QIs and outcomes, and to help prioritize targets for quality improvement in the care of older surgical patients.

Five-year lung cancer mortality risk analysis and topography in Xuan Wei: a spatiotemporal correlation analysis.

BACKGROUND: In Xuan Wei, China, the lung cancer mortality rate is rising significantly more than that of the nation overall. However, it remains unclear 1) if improved diagnosis can just partially explain this observation and how other local risk factors may be correlated with the lung cancer mortality rate and 2) how the lung cancer mortality rates differ within Xuan Wei and how these spatiotemporal patterns are linked with local risk factors. To increase etiological knowledge, this study evaluated the spatial and temporal distributions of the health effects (the lung cancer mortality rates) from 2011 to 2015. METHODS: Four steps of spatial analysis were applied, as follows: 1) hotspot analysis to determine the geographical patterns of lung cancer mortality, 2) spatially-weighted sum to identify areas with higher health risks, 3) bivariate statistical analysis to assess the overall correlation between coal mines and lung cancer mortality, and 4) geographically-weighted regression to test for correlations among different towns within Xuan Wei. RESULTS: Women had higher lung cancer mortality rates than those in men, with an increasing trend in both sexes over time. The incidence rates in Laibin Town were the highest in Xuan Wei every year. Over the 5-year study period, the lung cancer mortality was increasingly concentrated in Laibin, Shuanglong, and Longchang, where the smoky coal mines are most concentrated. The population-level health risks from the coal mine in Xuan Wei were mapped and divided into five types of risk areas (Type I - Type IV). Correlation analysis revealed that there was no significant correlation between lung cancer mortality as a whole and coal mine distribution during the 5-year study period. However, the geographically-weighted regression revealed a stronger correlation in medium (Type III) and second-lowest (Type IV) health risks. CONCLUSIONS: Xuan Wei lung cancer mortality has increased continuously since the third national retrospective surveys on the causes of death by the Ministry of Health of the People's Republic of China (2004-2005), especially for local women and residents over 35 years of age. Geographically, lung cancer in Xuan Wei showed unique spatiotemporal clustering. The local lung cancer mortality was significantly correlated with the smoky coal mine geographically. Some specific towns (Laibin, Shuanglong, and Longchang) within Xuan Wei manifested high correlations between lung cancer mortality and coal mines. The effects of coal mines on lung cancer mortality rates also spread geographically outward from these areas. Public health concern regarding lung cancer in Xuan Wei should prioritize higher-risk towns surrounded by smoking coal mines. Intervention strategies for particular toxic coal types require further studies on their chemical characteristics and mechanisms of carcinogenesis. Additional studies are also warranted to systematically examine the local environmental health risks related to coal industries and combustion air pollution and eventually to conduct early screening of lung cancer for local people who are more exposed to smoky coal in high-risk areas.

Pneumonia Hospitalization Risk in the Elderly Attributable to Cold and Hot Temperatures in Hong Kong, China.

The growth of pathogens potentially relevant to respiratory tract infection may be triggered by changes in ambient temperature. Few studies have examined the association between ambient temperature and pneumonia incidence, and no studies have focused on the susceptible elderly population. We aimed to examine the short-term association between ambient temperature and geriatric pneumonia and to assess the disease burden attributable to cold and hot temperatures in Hong Kong, China. Daily time-series data on emergency hospital admissions for geriatric pneumonia, mean temperature, relative humidity, and air pollution concentrations between January 2005 and December 2012 were collected. Distributed-lag nonlinear modeling integrated in quasi-Poisson regression was used to examine the exposure-lag-response relationship between temperature and pneumonia hospitalization. Measures of the risk attributable to nonoptimal temperature were calculated to summarize the disease burden. Subgroup analyses were conducted to examine the sex difference. We observed significant nonlinear and delayed associations of both cold and hot temperatures with pneumonia in the elderly, with cold temperatures having stronger effect estimates. Among the 10.7% of temperature-related pneumonia hospitalizations, 8.7% and 2.0% were attributed to cold and hot temperatures, respectively. Most of the temperature-related burden for pneumonia hospitalizations in Hong Kong was attributable to cold temperatures, and elderly men had greater susceptibility.

The influence of pre-existing health conditions on short-term mortality risks of temperature: Evidence from a prospective Chinese elderly cohort in Hong Kong.

BACKGROUND: Both cold and hot temperatures are associated with adverse health outcomes. Less is known about the role of pre-existing medical conditions to confer individual's susceptibility to temperature extremes. METHODS: We studied 66,820 subjects aged ≥65 who were enrolled and interviewed in all the 18 Elderly Health Centers of Department of Health, Hong Kong from 1998 to 2001, and followed up for 10-13 years. The distributed lag nonlinear model (DLNM) combined with a nested case-control study design was applied to estimate the nonlinear and delayed effects of cold or hot temperature on all natural mortality among subjects with different pre-existing diseases. RESULTS: The relative risk of all natural mortality associated with a decrease of temperature from 25th percentile (19.5°C) to 1st percentile (11.3°C) over 0-21 lag days for participants who reported to have an active disease at the baseline was 2.21 (95% confidence interval (CI): 1.19, 4.10) for diabetes mellitus (DM), 1.59 (1.12, 2.26) for circulatory system diseases (CSD), and 1.23 (0.53, 2.84) for chronic obstructive pulmonary disease (COPD), whereas 1.04 (0.59, 1.85) for non-disease group (NDG). Compared with NDG, elders with COPD had excess risk of mortality associated with thermal stress attributable to hot temperature, while elders with DM and CSD were vulnerable to both hot and cold temperatures. CONCLUSIONS: Elders with pre-existing health conditions were more vulnerable to excess mortality risk to hot and/or cold temperature. Preventative measures should target on elders with chronic health problems.

Prescriber decision-making on antithrombotic therapy after endovascular intervention for peripheral artery disease: a protocol for a discrete choice experiment.

INTRODUCTION: Peripheral artery disease (PAD) is a major risk factor for cardiovascular morbidity and mortality, despite surgical and endovascular treatments. Emerging evidence supports the use of immediate antithrombotic medications after endovascular intervention for PAD, however, there is a lack of consensus regarding choice and duration of antithrombotic therapy. Prescriber decision-making is a complex process, with prior studies demonstrating patient factors can influence variability in antithrombotic therapy for PAD. However, it remains unclear the relative contribution of these factors. This paper describes a planned study that aims to (1) determine the influence of patient factors on clinician preference for antithrombotic therapy following endovascular intervention and (2) compare differences in prescribing preferences between consultant vascular surgeons and trainees. METHODS AND ANALYSIS: This cross-sectional survey will evaluate antithrombotic prescribing choices using a discrete choice experiment (DCE) that has been developed and piloted for this study. A list of attributes and levels was generated using a mixed-methods approach. This included an extensive literature review and semistructured interviews with prescribing clinicians. Following final selection of included attributes, specialised software was used to construct a D-efficient design for the DCE questionnaire. The electronic questionnaire will be administered to vascular trainees and consultant surgeons across Australia. These data will be analysed using multinomial logistic regression, treating the decision to prescribe antithrombotic therapy as a function of both the attributes of the two alternatives, as well as characteristics of the respondent. Latent class analysis will be used to explore heterogeneity of responses. ETHICS AND DISSEMINATION: Ethics approval was obtained from the University of Sydney Human Ethics committee (2023/474). The results of this study will be published in peer-reviewed journals and presented at national vascular surgical conferences. These results will be used to improve understanding how clinicians make prescribing decisions and to inform future strategy to enhance guideline-directed prescribing.

Using building heights and street configuration to enhance intraurban PM10, NO(X), and NO2 land use regression models.

Land use regression (LUR) models have been widely used to provide long-term air pollution exposure assessment in epidemiological studies. However, models have rarely offered variables that account for the dispersion environment close to the source (e.g., street canyons, position and dimensions of buildings, road width). This study used newly available data on building heights and geometry to enhance the representation of land use and the dispersion field in LUR. Models were developed for PM10, NO(X), and NO2 for 2008-2011 for London, U.K. A separate set of models using "traditional" land use and traffic indicators (e.g., distance from road, area of housing within circular buffers) were also developed and their performance was compared with "enhanced" models. Models were evaluated using leave-one-out (n - 1) (LOOCV) and grouped (n - 25%) cross-validation (GCV). LOOCV R(2) values were 0.71, 0.50, 0.66 and 0.73, 0.79, 0.78 for traditional and enhanced PM10, NOX, and NO2 models, respectively. GCV R(2) values were 0.71, 0.53, 0.64 and 0.68, 0.77, 0.77 for traditional and enhanced PM10, NO(X), and NO2 models, respectively. Data on building volume within the area common to a 20 m road buffer within a 25 m circular buffer substantially improved the performance (R(2) > 13%) of NO(X) and NO2 LUR models.

Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

Chronic occlusion of the thoracic aorta: a novel cause of pleuropericardial effusions and pancytopenia.

A 57-year-old man had presented with a 6-month history of worsening dyspnea, renal failure, hypertension, pancytopenia, and a continuous machinery murmur. Imaging studies revealed pleuropericardial effusions that recurred despite aspiration and suprarenal mid-thoracic aortic occlusion (AO) with extensive collateral vessels to the chest wall, rectus sheath, and diaphragm. A right axillofemoral bypass transformed his clinical course. The murmurs, renal failure, pleuropericardial drainage, and pancytopenia resolved, and his hypertension had markedly improved. The association of chronic AO with pleuropericardial effusions without peripheral edema or ascites was most likely due to increased supradiaphragmatic interstitial pressure, and the bone marrow hypoperfusion likely explains the pancytopenia. In addition to posing diagnostic challenges, chronic AO reveals unique insights into the pathogenesis of pleuropericardial effusions and pancytopenia.

Forgotten Elastic Band as an Unusual Cause of Limb Ulceration: Case Report and Review of the Literature.

We discuss a case of circumferential ulceration of the lower leg in a cognitively impaired elderly man with poor tissue integrity. Thorough clinical examination eventually determined the cause as being a circumferentially placed, forgotten elastic band causing ulceration via sustained tension around the limb. Circumferential application of an elastic band to an extremity is an exceedingly rare but serious cause of lower leg ulceration.

Vertical monitoring of traffic-related air pollution (TRAP) in urban street canyons of Hong Kong.

Rapid urbanization has significantly increased air pollution especially in urban regions with high traffic volumes. Existing methods for estimating traffic-related air pollution (TRAP) and TRAP-related health impacts are based on two-dimensional modelling. This paper describes a point-based methodology to monitor vertical pollutant concentrations in typical street canyons of Hong Kong. It explains the conceptual design, monitoring strategy and selection criteria for a limited number of receptor locations in street canyons to undertake field measurements for both outdoor exposure and indoor infiltration. It also expounds on the limitations and complications associated with field instrumentation and retention of participating home units. The empirical results were applied on the building infiltration efficiencies assessment. It is concluded that the cost-effective field methodology developed in this paper expects to strike a balance between exposure error and limited data locations. These findings will have important implications in future monitoring design of vertical TRAP exposure to support health studies.

When employees strike back: investigating mediating mechanisms between psychological contract breach and workplace deviance.

In this article, psychological contract breach, revenge, and workplace deviance are brought together to identify the cognitive, affective, and motivational underpinnings of workplace deviance. On the basis of S. L. Robinson and R. J. Bennett's (1997) model of workplace deviance, the authors proposed that breach (a cognitive appraisal) and violation (an affective response) initiate revenge seeking. Motivated by revenge, employees then engage in workplace deviance. Three studies tested these ideas. All of the studies supported the hypothesized relationships. In addition, self-control was found to be a moderator of the relationship between revenge cognitions and deviant acts; the relationship was weaker for people high in self-control.

Integrating travel behavior with land use regression to estimate dynamic air pollution exposure in Hong Kong.

BACKGROUND: Epidemiological studies typically use subjects' residential address to estimate individuals' air pollution exposure. However, in reality this exposure is rarely static as people move from home to work/study locations and commute during the day. Integrating mobility and time-activity data may reduce errors and biases, thereby improving estimates of health risks. OBJECTIVES: To incorporate land use regression with movement and building infiltration data to estimate time-weighted air pollution exposures stratified by age, sex, and employment status for population subgroups in Hong Kong. METHODS: A large population-representative survey (N = 89,385) was used to characterize travel behavior, and derive time-activity pattern for each subject. Infiltration factors calculated from indoor/outdoor monitoring campaigns were used to estimate micro-environmental concentrations. We evaluated dynamic and static (residential location-only) exposures in a staged modeling approach to quantify effects of each component. RESULTS: Higher levels of exposures were found for working adults and students due to increased mobility. Compared to subjects aged 65 or older, exposures to PM2.5, BC, and NO2 were 13%, 39% and 14% higher, respectively for subjects aged below 18, and 3%, 18% and 11% higher, respectively for working adults. Exposures of females were approximately 4% lower than those of males. Dynamic exposures were around 20% lower than ambient exposures at residential addresses. CONCLUSIONS: The incorporation of infiltration and mobility increased heterogeneity in population exposure and allowed identification of highly exposed groups. The use of ambient concentrations may lead to exposure misclassification which introduces bias, resulting in lower effect estimates than 'true' exposures.

Long term exposure to air pollution and mortality in an elderly cohort in Hong Kong.

BACKGROUND: Several studies have reported associations between long term exposure to air pollutants and cause-specific mortality. However, since the concentrations of air pollutants in Asia are much higher compared to those reported in North American and European cohort studies, cohort studies on long term effects of air pollutants in Asia are needed for disease burden assessment and to inform policy. OBJECTIVES: To assess the effects of long-term exposure to particulate matter with aerodynamic diameter < 2.5 µm (PM2.5), black carbon (BC) and nitrogen dioxide (NO2) on cause-specific mortality in an elderly cohort in Hong Kong. METHODS: In a cohort of 66,820 participants who were older than or equal to 65 years old in Hong Kong from 1998 to 2011, air pollutant concentrations were estimated by land use regression and assigned to the residential addresses of all participants at baseline and for each year during a 11 year follow up period. Hazard ratios (HRs) of cause-specific mortality (including all natural cause, cardiovascular and respiratory mortality) associated with air pollutants were estimated with Cox models, including a number of personal and area-level socioeconomic, demographic, and lifestyle factors. RESULTS: The median concentration of PM2.5 during the baseline period was 42.2 µg/m3 with an IQR of 5.5 µg/m3, 12.1 (9.6) µg/m3 for BC and 104 (25.6) µg/m3 for NO2. For PM2.5, adjusted HR per IQR increase and per 10 µg/m3 for natural cause mortality was 1.03 (95%CI: 1.01, 1.06) and 1.06 (95%CI: 1.02, 1.11) respectively. The corresponding HR were 1.06 (95%CI: 1.02, 1.10) and 1.01 (95%CI: 0.96, 1.06) for cardiovascular disease and respiratory disease mortality, respectively. For BC, the HR of an interquartile range increase for all natural cause mortality was 1.03 (95%CI: 1.00, 1.05). The corresponding HR was 1.07 (95%CI: 1.03, 1.11) and 0.99 (95%CI: 0.94, 1.04) for cardiovascular disease and respiratory disease mortality. For NO2, almost all HRs were approximately 1.0, except for IHD (ischemic heart disease) mortality. CONCLUSION: Long-term exposure to ambient PM2.5 and BC was associated with an elevated risk of cardiovascular mortality. Despite far higher air pollution exposure concentrations, HRs per unit increase in PM2.5 were similar to those from recent comparable studies in North America.

Land use regression modelling of air pollution in high density high rise cities: A case study in Hong Kong.

Land use regression (LUR) is a common method of predicting spatial variability of air pollution to estimate exposure. Nitrogen dioxide (NO2), nitric oxide (NO), fine particulate matter (PM2.5), and black carbon (BC) concentrations were measured during two sampling campaigns (April-May and November-January) in Hong Kong (a prototypical high-density high-rise city). Along with 365 potential geospatial predictor variables, these concentrations were used to build two-dimensional land use regression (LUR) models for the territory. Summary statistics for combined measurements over both campaigns were: a) NO2 (Mean=106µg/m3, SD=38.5, N=95), b) NO (M=147µg/m3, SD=88.9, N=40), c) PM2.5 (M=35µg/m3, SD=6.3, N=64), and BC (M=10.6µg/m3, SD=5.3, N=76). Final LUR models had the following statistics: a) NO2 (R2=0.46, RMSE=28µg/m3) b) NO (R2=0.50, RMSE=62µg/m3), c) PM2.5 (R2=0.59; RMSE=4µg/m3), and d) BC (R2=0.50, RMSE=4µg/m3). Traditional LUR predictors such as road length, car park density, and land use types were included in most models. The NO2 prediction surface values were highest in Kowloon and the northern region of Hong Kong Island (downtown Hong Kong). NO showed a similar pattern in the built-up region. Both PM2.5 and BC predictions exhibited a northwest-southeast gradient, with higher concentrations in the north (close to mainland China). For BC, the port was also an area of elevated predicted concentrations. The results matched with existing literature on spatial variation in concentrations of air pollutants and in relation to important emission sources in Hong Kong. The success of these models suggests LUR is appropriate in high-density, high-rise cities.

Major air pollutants and risk of COPD exacerbations: a systematic review and meta-analysis.

BACKGROUND: Short-term exposure to major air pollutants (O3, CO, NO2, SO2, PM10, and PM2.5) has been associated with respiratory risk. However, evidence on the risk of chronic obstructive pulmonary disease (COPD) exacerbations is still limited. The present study aimed at evaluating the associations between short-term exposure to major air pollutants and the risk of COPD exacerbations. METHODS: After a systematic search up until March 30, 2016, in both English and Chinese electronic databases such as PubMed, EMBASE, and CNKI, the pooled relative risks and 95% confidence intervals were estimated by using the random-effects model. In addition, the population-attributable fractions (PAFs) were also calculated, and a subgroup analysis was conducted. Heterogeneity was assessed by I2. RESULTS: In total, 59 studies were included. In the single-pollutant model, the risks of COPD were calculated by each 10 µg/m3 increase in pollutant concentrations, with the exception of CO (100 µg/m3). There was a significant association between short-term exposure and COPD exacerbation risk for all the gaseous and particulate pollutants. The associations were strongest at lag0 and lag3 for gaseous and particulate air pollutants, respectively. The subgroup analysis not only further confirmed the overall adverse effects but also reduced the heterogeneities obviously. When 100% exposure was assumed, PAFs ranged from 0.60% to 4.31%, depending on the pollutants. The adverse health effects of SO2 and NO2 exposure were more significant in low-/middle-income countries than in high-income countries: SO2, relative risk: 1.012 (95% confidence interval: 1.001, 1.023); and NO2, relative risk: 1.019 (95% confidence interval: 1.014, 1.024). CONCLUSION: Short-term exposure to air pollutants increases the burden of risk of COPD acute exacerbations significantly. Controlling ambient air pollution would provide benefits to COPD patients.

Suffering in silence: Investigating the role of fear in the relationship between abusive supervision and defensive silence.

Drawing from an approach-avoidance perspective, we examine the relationships between subordinates' perceptions of abusive supervision, fear, defensive silence, and ultimately abusive supervision at a later time point. We also account for the effects of subordinates' assertiveness and individual perceptions of a climate of fear on these predicted mediated relationships. We test this moderated mediation model with data from three studies involving different sources collected across various measurement periods. Results corroborated our predictions by showing (a) a significant association between abusive supervision and subordinates' fear, (b) second-stage moderation effects of subordinates' assertiveness and their individual perceptions of a climate of fear in the abusive supervision-fear-defensive silence relationship (with lower assertiveness and higher levels of climate-of-fear perceptions exacerbating the detrimental effects of fear resulting from abusive supervision), and (c) first-stage moderation effects of subordinates' assertiveness and climate-of-fear perceptions in a model linking fear to defensive silence and abusive supervision at a later time. Theoretical and practical implications are discussed. (PsycINFO Database Record

Model predictions for the wide-angle x-ray scatter signals of healthy and malignant breast duct biopsies.

Wide-angle x-ray scatter (WAXS) could potentially be used to diagnose ductal carcinoma in situ (DCIS) in breast biopsies. The regions of interest were assumed to consist of fibroglandular tissue and epithelial cells and the model assumed that biopsies with DCIS would have a higher concentration of the latter. The scattered number of photons from a 2-mm diameter column of tissue was simulated using a 110-kV beam and selectively added in terms of momentum transfer. For a 1-min exposure, specificities and sensitivities of unity were obtained for biopsies 2- to 20-mm thick. The impact of sample and tumor cell layer thicknesses was studied. For example, a biopsy erroneously estimated to be 8 mm would be correctly diagnosed if its actual thickness was between 7.3 and 8.7 mm. An 8-mm thick malignant biopsy can be correctly diagnosed provided the malignant cell layer thickness is [Formula: see text]. WAXS methods could become a diagnostic tool for DCIS within breast biopsies.

A method to estimate the fractional fat volume within a ROI of a breast biopsy for WAXS applications: animal tissue evaluation.

PURPOSE: To develop a method to estimate the mean fractional volume of fat (ν¯fat) within a region of interest (ROI) of a tissue sample for wide-angle x-ray scatter (WAXS) applications. A scatter signal from the ROI was obtained and use of ν¯fat in a WAXS fat subtraction model provided a way to estimate the differential linear scattering coefficient µs of the remaining fatless tissue. METHODS: The efficacy of the method was tested using animal tissue from a local butcher shop. Formalin fixed samples, 5 mm in diameter 4 mm thick, were prepared. The two main tissue types were fat and meat (fibrous). Pure as well as composite samples consisting of a mixture of the two tissue types were analyzed. For the latter samples, νfat for the tissue columns of interest were extracted from corresponding pixels in CCD digital x-ray images using a calibration curve. The means ν¯fat were then calculated for use in a WAXS fat subtraction model. For the WAXS measurements, the samples were interrogated with a 2.7 mm diameter 50 kV beam and the 6° scattered photons were detected with a CdTe detector subtending a solid angle of 7.75 × 10(-5) sr. Using the scatter spectrum, an estimate of the incident spectrum, and a scatter model, µs was determined for the tissue in the ROI. For the composite samples, a WAXS fat subtraction model was used to estimate the µs of the fibrous tissue in the ROI. This signal was compared to µs of fibrous tissue obtained using a pure fibrous sample. RESULTS: For chicken and beef composites, ν¯fat=0.33±0.05 and 0.32 ± 0.05, respectively. The subtractions of these fat components from the WAXS composite signals provided estimates of µs for chicken and beef fibrous tissue. The differences between the estimates and µs of fibrous obtained with a pure sample were calculated as a function of the momentum transfer x. A t-test showed that the mean of the differences did not vary from zero in a statistically significant way thereby validating the methods. CONCLUSIONS: The methodology to estimate ν¯fat in a ROI of a tissue sample via CCD x-ray imaging was quantitatively accurate. The WAXS fat subtraction model allowed µs of fibrous tissue to be obtained from a ROI which had some fat. The fat estimation method coupled with the WAXS models can be used to compare µs coefficients of fibroglandular and cancerous breast tissue.

Uncommon causes of anterior urethral diverticula in children: Two cases and review of literature.

Anterior urethral diverticula are rare in children. Anterior urethral valves and associated diverticulum is the commonly discussed pathological entity in children. There is a lack of awareness among clinicians regarding less common presentations of anterior urethral diverticula in children; which can have a diverse involvement of the urinary tract. This report describes two uncommon presentations of anterior urethral diverticula in children, their diagnoses and management. A systematic differential diagnosis and review of anterior urethral diverticula in children is also presented.