Estimating evaporation rates and contaminant air concentrations due to small spills of non-ideal aqueous organic solvent mixtures in a controlled environment

Although small spills of non-ideal organic solvent mixtures are ubiquitous undesirable events in occupational settings, the potential risk of exposure associated with such scenarios remains insufficiently investigated. This study aimed to examine the impact of non-ideality on evaporation rates and contaminant air concentrations resulting from small spills of organic solvent mixtures. Evaporation rate constants alphas (α) were experimentally measured for five pure solvents using a gravimetric approach during solvent evaporation tests designed to simulate small spills of solvents. Two equations were used for estimating contaminants' evaporation rates from aqueous mixtures assuming either ideal or non-ideal behavior based on the pure-chemical alpha values. A spill model also known as the well-mixed room model with exponentially decreasing emission rate was used to predict air concentrations during various spill scenarios based on the two sets of estimated evaporation rates. Model predictive performance was evaluated by comparing the estimates against real-time concentrations measured for the same scenarios. Evaluations for 12 binary non-ideal aqueous mixtures found that the estimated evaporation rates accounting for the correction by the activity coefficients of the solvents (median = 0.0318 min^-1) were higher than the evaporation rates estimated without the correction factor (median = 0.00632 min^-1). Model estimates using the corrected evaporation rates reasonably agreed with the measured values, with a median predicted peak concentrations-to-measured peak concentrations ratio of 0.92 (0.81 to 1.32) and a median difference between the predicted and the measured peak times of -5 min. By contrast, when the non-corrected evaporation rates were used, the median predicted peak concentrations-to-measured peak concentrations ratio was 0.31 (0.08 to 0.75) and the median difference between the predicted and the measured peak times was +33 min. Results from this study demonstrate the importance of considering the non-ideality effect for accurately estimating evaporation rates and contaminant air concentrations generated by solvent mixtures. Moreover, this study is a step further in improving knowledge of modeling exposures related to small spills of organic solvent mixtures.

Filtration performance, fit test and side effects of respiratory personal protective equipment following decontamination: Observations for user safety and comfort

OBJECTIVE

While facing personal protective equipment (PPE) shortages during the COVID-19 pandemic, several institutions looked to PPE decontamination and reuse options. This study documents the effect of two hydrogen peroxide treatments on filtration efficiency and fit tests as well as the side effects for volunteers after the decontamination of N95 filtering facepiece respirators (FFRs). We also propose an efficient and large-scale treatment protocol that allows for the traceability of this protective equipment in hospitals during PPE shortages.

METHODS

The effects of low-temperature hydrogen peroxide sterilization and hydrogen peroxide vapor (HPV) on two FFR models (filtration, decontamination level, residual emanation) were evaluated. Ten volunteers reported comfort issues and side effects after wearing 1h FFRs worn and decontaminated up to five times.

RESULTS

The decontamination process does not negatively affect FFR efficiency, but repeated use and handling tend to lead to damage, limiting the number of times FFRs can be reused. Moreover, the recommended 24-h post-treatment aeration does not sufficiently eliminate residual hydrogen peroxide. Prolonged aeration time increased user comfort when using decontaminated FFRs.

CONCLUSIONS

HPV and low-temperature hydrogen peroxide sterilization seem to be appropriate treatments for FFR decontamination when the PPE is reused by the same user. PPE decontamination and reuse methods should be carefully considered as they are critical for the comfort and safety of healthcare workers.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Predicting first-order evaporation rate constant alpha (α) from small spills of organic solvents in a controlled environment

Exposures to vapors generated by small spills of organic solvents are common in the occupational hygiene practice. In these scenarios, contaminant mass release is exponentially decreasing, driven by an evaporation rate constant alpha (α). Knowing α is fundamental for adequately modeling peak concentrations and/or short-term exposures that occur and for achieving efficient occupational risk analysis and management. The purpose of this study was to measure alpha experimentally using a gravimetric approach in a controlled environment during solvent evaporation tests designed to simulate small spills of solvents. The effects of several factors on α were evaluated. Equations based on regression models derived from the experimental data were proposed for predicting α. Predictions were externally validated against experimental data. A total of 183 tests was performed. Data analyses found that alpha (α) values increased with vapor pressure, spill surface area-to-spill volume ratio, and air speed across the spill. Larger α were associated with petri dish containers compared to watch glasses. Three regression models were created for predicting α. They had four variables in common, namely vapor pressure, molecular weight, air speed above the liquid, and surface tension of the liquid. The fifth variable was either spill volume, spill surface area, or spill surface area-to-spill volume ratio. The R² of the regression models were equal to 0.98. External validation showed mean relative errors of -32.9, -32.0, and -25.5%, respectively, with associated standard deviations of the relative errors of 17.7, 33.3, and 26.0%, respectively, and associated R² of 0.92, 0.65, and 0.87, respectively. The proposed equations can be used for estimating α in exposure scenarios similar to those evaluated in this study. Moreover, these models constitute a step further in the improvement of knowledge on estimating evaporation rates for small spills of organic solvents.

Sulodexide in the treatment of patients with long COVID 19 symptoms and endothelial dysfunction: The results of TUN-EndCOV study

Background

Endothelial dysfunction is probably one of the mechanisms of long COVID-19 symptoms. Sulodexide has pleiotropic properties within the vascular endothelium that can prove beneficial in the long COVID-19 symptoms.

Purpose

We aimed to evaluate the effect of sulodexide when used in patients with endothelial dysfunction and long COVID-19 symptoms.

Methods

We conducted a prospective multicenter longitudinal case-control study. Endothelial function was evaluated with DTM “E4-Diagnose” Polymath based on the Endothelium Quality Index (EQI). A group of patients with endothelial dysfunction (EQI < 2.0) received sulodexide. All the patients were followed-up 21 days after inclusion. Primary outcomes were defined as endothelial function amelioration (delta EQI) and long COVID-19 symptoms evolution during the follow-up.

Results

A total of 410 patients were included in this study. Patients were included at an average time of 1.89 ± 1.2 month after COVID-19 infection. At inclusion, 210 (51.2%) patients had an EQI < 2. The median age was 49 ± 13.8 (18–80) years. Among the patients with endothelial dysfunction, only 79 patients received sulodexide. Patients in sulodexide group had lower EQI than the non-medical intervention group (0.94 ± 0.6 vs. 1.52 ± 0.4; P < 10⁻³). They were more diabetic, hypertensive, had more coronary artery disease and received more long-term medications (aspirin, Bblockers and statins) than the others (P = 0.01, 0.002, 0.01, 0.009, 0.001 and 0.01, respectively). At the 21-days follow-up, patients in sulodexide group presented lower long COVID symptoms especially chest pain, palpitations, fatigue and neuro-cognitive difficulties associated to a significant amelioration of endothelial function (delta EQI 1.26 ± 1.07 vs. 0.22 ± 0.7; P < 10⁻³).

Conclusion

Sulodexide in patients with long COVID-19 may be a good intervention to ameliorate chest pain, palpitations, fatigue and neuro-cognitive difficulties associated to endothelial dysfunction.

Left ventricular global longitudinal strain alteration in young patient and correlation with post-COVID syndrome (TUN END COV Study)

Background

Several protocols are in study to understand mechanisms of these persistent symptoms of COVID-19. The conventional echocardiography can be a good tool to detect abnormalities in the cardiovascular system induced by long COVID-19.

Objective

Correlation between echocardiographic parameters and symptoms of long COVID and the spontaneous evolution at one month of follow-up.

Patients and methods

A prospective multicentric study including a total of 630 patients diagnosed with COVID-19, 2 weeks to one month after recovering from COVID-19. Young patients without any medical history other than recent SARS-CoV2 infection are selected. A meticulous interrogation and clinical examination as well as an echocardiography are performed in all of patients. In addition to symptoms, we assessed echocardiographic parameters including initial left ventricular global longitudinal strain (initial SLG: SLGi) and after one month (SLG control: SLGc).

Results

Mean SLGi was −18.1 ± 2.4 in study group (−19.6 ± 1.5; P < 0.001). Forty-two patients (52.5%) had initially altered strain versus 38 patients (47.5%) with normal strain. The threshold value for SLG in our study has been established using ROC curve which was −17.95% with sensibility (52.5%) and specificity (83.7%). we found a statistically significative correlation between the initial alteration of SLG and persistent symptoms in multivariate test: dyspnea (P < 0.002); chest pain (P = 0.031). At one month of follow-up, 87.5% of patients improved their SLG. And there was a correlation between control GS value (mean SLGc was −18.91 ± 3.33; P = 0.002) associated with a marked improvement in symptoms (P = 0.001).

Conclusion

We reported here an original case series of SLG alteration induced by SARS-CoV2 infection that is correlated with the presence of chest pain and dyspnea. However, this affection seems to be spontaneously significantly reversible and associated with significant clinical improvement.

Endothelial dysfunction is the key of long COVID-19 symptoms: The results of TUN-EndCOV study

Background

The COVID-19 disease is a multisystem disease due to in part to the vascular endothelium injury. Lasting effects and long-term sequalae could persist after the infection and may be due to persistent endothelial dysfunction.

Purpose

Our study focused on the study of endothelial function measurement by digital thermal monitoring (DTM) of endothelial quality index with E4 diagnosis Polymath in a large cohort of long COVID-19 patients to determine whether long COVID-19 symptoms are due to endothelial dysfunction.

Methods

This is a prospective multicenter longitudinal observational cohort study. Endothelial function was evaluated with “E4-Diagnose” Polymath Tunisia based on the Endothelium Quality Index (EQI). A complete echocardiographic evaluation analysis was performed. Primary outcomes were defined as the occurrence of long COVID-19 symptoms in patients with endothelial dysfunction measured by EQI.

Results

A total of 798 patients were included in this study. Patients were included at an average time of 68.93 ± 43.1 days. The mean EQI was 2.02 ± 0.99 [0–5]. A total of 397 (49.7%) patients had poor or very poor EQI and 211 (26.4%) patients had very poor EQI. The median age was 49.94 ± 14.2 (18–80) years. A total of 618 patients (77.4%) had long COVID-19 symptoms. Patients with long COVID-19 symptoms had a reduced EQI (1.99 ± 0.97 vs. 2.09 ± 1.05, P = 0.24). Among long COVID-19 symptoms, fatigue was the most common symptom reported in 42.2%. Fatigue and chest pain were significantly associated to the endothelial dysfunction (P = 0.04 and 0.001 respectively). Patients with chest pain had significantly lower EQI (1.74 ± 1.0 vs. 2.09 ± 0.9, P ≤ 10⁻³) and LVGLS (−16.35 ± 3.0 vs. −17.16 ± 2.5, P = 0.04).

Conclusion

Long COVID-19 symptoms specifically chest pain and fatigue are due to persistent poor endothelial quality index. These findings allow a better care of patients with long COVID-19 symptoms.

[Impact of socioeconomic factors on blood pressure control: Observational study about 2887 hypertensive patients]

INTRODUCTION

Despite therapeutic progress, less than half of hypertensive patients are controlled. The objective of this study was to examine the links between blood pressure control and socioeconomic factors.

METHODS

We used data collected in the cardiology department of Sfax University Hospital as part of the Tunisian national hypertension registry. We studied the associations between the socio-economic variables (educational level, profession, medical insurance) and optimal blood pressure control (SBP<140mmHg and DBP<90mmHg) using logistic regression models.

RESULTS

The average age of our population was 65 and the sex ratio was 0.95. We found, as expected, the clinical and behavioral factors associated with a good blood pressure control, namely: female sex, low-sodium diet, therapeutic compliance, and regular physical activity. However, obesity and an increased number of antihypertensive drugs have been associated with poor blood pressure control. The study of the effect of socio-economic variables on BP control finds a significant gradient against the most disadvantaged social categories for our three social variables in the univariate analysis. The inclusion of clinical and behavioral factors in the multivariate analysis attenuated these associations but did not fully explain them.

CONCLUSION

Our study shows that there are social inequalities in the control of blood pressure. Social justice and improving living conditions are probably the real solutions to the problem of these social inequalities in health.

How Effective Is the Filtration of 'KN95' Filtering Facepiece Respirators During the COVID-19 Pandemic?

Objectives

The high demand of filtering facepiece respirators (FFRs) worldwide during the period of the COVID-19 pandemic has led to a critical situation for decision-makers regarding their supply. After authorizing the use of FFRs certified by other regions of the world, decision-makers in many countries have published alerts, particularly concerning the ‘KN95’ type.

Methods

This paper investigated the filtration performance of different FFRs using an experimental setup already employed during several studies on FFRs filtration performance. Its high-resolution measuring devices permit to determine filtration performance according to the normative criteria: the pressure drop and the filtration efficiency. Eight different FFRs have been used: four NIOSH-approved FFRs and four not NIOSH-approved with a ‘KN95’ shape available during the beginning of the COVID-19 pandemic.

Results

The data show a high disparity between different FFRs purchased by healthcare establishments, and between those that are NIOSH-approved and those that are not NIOSH-approved. The results confirm that the NIOSH certification offers good protection according to the normative criteria. The ‘KN95’ types present pressure drops which correspond to the normative value, however their efficiencies are lower than the efficiencies of FFRs certified by NIOSH and lower than 95% at the most penetrate particle size.

Conclusions

FFRs marking is not sufficient to conclude on the FFRs’ efficiency. Visual inspection can not determine which samples are counterfeit or have manufacturing defects.

Modeling occupational exposure to solvent vapors using the Two-Zone (near-field/far-field) model: a literature review

The Two-Zone model is used in occupational hygiene to predict both near-field and far-field airborne contaminant concentrations. A literature review was carried out on 21 scientific publications in which the Two-Zone model was used to assess occupational exposure to solvent vapors. Data on exposure scenarios, solvents, generation/emission rates, near- and far-field parameters, and model performance were collected and analyzed. Over the 24 exposure scenarios identified, 18 were evaluated under controlled conditions, 5 under normal workplace activities, and 1 was reported based on literature data. The scenarios involved a variety of tasks which consisted, mostly, of cleaning metal parts, spraying solvents onto surfaces, spilling liquids, and filling containers with volatile substances. Twenty-eight different solvents were modeled and the most commonly tested were benzene, toluene, and acetone. Emission rates were considered constant in 16 scenarios, exponentially decreasing in 6 scenarios, and intermittent in 2 scenarios. Four-hundred-and-forty-six (446) predicted-to-measured concentration ratios were calculated across the 21 studies; 441 were obtained in controlled conditions, 4 under normal workplace activities, and 1 was calculated based on the literature data. For controlled studies, the Two-Zone model predictive performance was within a factor of 0.3-3.7 times the measured concentrations with 93% of the values between 0.5 and 2. The model overestimated the measured concentrations in 63% of the evaluations. The median predicted concentration for the near-field was 1.38 vs. 1.02 for the far-field. Results suggest that the model might be a useful tool for predicting occupational exposure to vapors of solvents by providing a conservative approach. Harmonization in model testing strategies and data presentation is needed in future studies to improve the assessment of the predictability of the Two-Zone model. Moreover, this review has provided a database of exposure scenarios, input parameter values, and model predictive performances which can be useful to occupational hygienists in their future modeling activities.

Filtering performances of 20 protective fabrics against solid aerosols

Workers can be exposed to solid airborne particles in some occupational environments, and they might be required to wear chemical protective clothing to prevent skin exposure. Dedicated standards exist to certify the protective value of such clothing, but they are not informative enough to identify the main pathways of entry for solid particles nor to compare performances between different chemical protective clothing. In this work, 20 non-woven fabrics used to make chemical protective clothing for solid particle protection were selected to be examined for both filtration and comfort performances. Nine were microporous fabrics (MP), 10 were multilayered nonwoven fibrous media (SMS) and one was a flash spun material (FS). To assess their filtration performances, fabrics were challenged in a benchtop wind tunnel with a 20-3,000 nm diameter sodium chloride aerosol at three low fabric face velocities (0.05, 0.15, 0.3 cm/sec). Airflow resistance and water vapor transmission rate were also measured to provide indications of comfort for the wearer. The penetration results led to the classification of the 20 fabrics into distinct groups of filtration efficiency. The data were analysed based on the porous media characteristics (thickness, fiber diameter, porosity, etc.). MPs were the most efficient fabrics, and SMSs showed a wide range of performances, mostly due to variations in the thickness of the filtering layer as well as to the fabric treatment. Measurements of airflow resistance and water vapor transmission rates revealed major differences between MPs and FSs and SMSs. This highlights the potential of some SMS fabrics to meet a compromise between protection and comfort.

A comparison of low versus high radioiodine administered activity in patients with low-risk differentiated thyroid cancer

Post-surgical therapeutic management of differentiated thyroid cancer (DTC) is still a controversial subject. Indeed, there is no consensus on the dose of ¹³¹I to be administered, although the current trend towards therapy easing through mini-cures for patients with good prognosis. To confirm the non-inferiority in terms of effectiveness of an ablative mini-cure from 1.11 to 1.85 GBq, over a cure of 3.7 GBq, in patients with DTC operated for low and very low risk. We retrospectively studied 157 patients with very low and low risk DTC, followed in the Nuclear Medicine Department of the Salah Azaiez Institute between 2002 and 2012. These patients had a complementary radioiodine therapy with either low dose (group A) or high dose (group B) with an evaluation at 6 months post treatment and in long-term. The study took place at a referral center. The average age was 42.8 ± 13.7 years with a female predominance (86.7 %). The DTC papillary represented the most common etiology (95 %) with a predominance of pure papillary (68 %) on the follicular variant (27 %). The first cure evaluation did not show statistically significant difference between the two approaches in terms of therapeutic ablative efficiency (p = 0.13). The overall success rate was 77 % (121/157), with 83 % (54/65) in group A and 72.8 % (67/92) in group B. The likelihood of having a remission from the first cure was 1.83 times greater for patients treated with low doses (OR = 1.83, 95 % CI 0.23-1.29). At the end of follow, we have noted one case of refractory disease. The male gender (adjusted OR = 2.71, 95 % CI 0.51-4.23, p = 0.03), and the baseline Tg ≥ 10 (ng/ml) (adjusted OR = 3.48, 95 % CI 1.25-9.67, p = 0.01) were significantly independent predictors of successful first cure ablation. The results provide that mini-dose protocol is not less effective for ablation of the thyroid remnant than 3.7 GBq activity.

Risk analysis for confined space entries: Critical analysis of four tools applied to three risk scenarios

Investigation reports of fatal confined space accidents nearly always point to a problem of identifying or underestimating risks. This paper compares 4 different risk analysis tools developed for confined spaces by applying them to 3 hazardous scenarios. The tools were namely 1. a checklist without risk estimation (Tool A), 2. a checklist with a risk scale (Tool B), 3. a risk calculation without a formal hazard identification stage (Tool C), and 4. a questionnaire followed by a risk matrix (Tool D). Each tool's structure and practical application were studied. Tools A and B gave crude results comparable to those of more analytic tools in less time. Their main limitations were lack of contextual information for the identified hazards and greater dependency on the user's expertise and ability to tackle hazards of different nature. Tools C and D utilized more systematic approaches than tools A and B by supporting risk reduction based on the description of the risk factors. Tool D is distinctive because of 1. its comprehensive structure with respect to the steps suggested in risk management, 2. its dynamic approach to hazard identification, and 3. its use of data resulting from the risk analysis.

Particle loading time and humidity effects on the efficiency of an N95 filtering facepiece respirator model under constant and inhalation cyclic flows

It is necessary to investigate the efficiencies of filtering facepiece respirators (FFRs) exposed to ultrafine particles (UFPs) for long periods of time, since the particle loading time may potentially affect the efficiency of FFRs. This article aims to investigate the filtration efficiency for a model of electrostatic N95 FFRs with constant and 'inhalation-only' cyclic flows, in terms of particle loading time effect, using different humidity conditions. Filters were exposed to generated polydisperse NaCl particles. Experiments were performed mimicking an 'inhalation-only' scenario with a cyclic flow of 85 l min(-1) as the minute volume [or 170 l min(-1) as mean inhalation flow (MIF)] and for two constant flows of 85 and 170 l min(-1), under three relative humidity (RH) levels of 10, 50, and 80%. Each test was performed for loading time periods of 6h and the particle penetration (10-205.4nm in electrical mobility diameter) was measured once every 2h. For a 10% RH, the penetration of smaller size particles (<80nm), including the most penetrating particle size (MPPS), decreased over time for both constant and cyclic flows. For 50 and 80% RH levels, the changes in penetration were typically observed in an opposite direction with less magnitude. The penetrations at MPPS increased with respect to loading time under constant flow conditions (85 and 170 l min(-1)): it did not substantially increase under cyclic flows. The comparison of the cyclic flow (85 l min(-1) as minute volume) and constant flow equal to the cyclic flow minute volume indicated that, for all conditions the penetration was significantly less for the constant flow than that of cyclic flow. The comparison between the cyclic (170 l min(-1) as MIF) and constant flow equal to cyclic flow MIF indicated that, for the initial stage of loading, the penetrations were almost equal, but they were different for the final stages of the loading time. For a 10% RH, the penetration of a wide range of sizes was observed to be higher with the cyclic flow (170 as MIF) than with the equivalent constant flow (170 l min(-1)). For 50 and 80% RH levels, the penetrations were usually greater with a constant flow (170 l min(-1)) than with a cyclic flow (170 l min(-1) as MIF). It is concluded that, for the tested electrostatic N95 filters, the change in penetration as a function of the loading time does not necessarily take place with the same rate under constant (MIF) and cyclic flow. Moreover, for all tested flow rates, the penetration is not only affected by the loading time but also by the RH level. Lower RH levels (10%) have decreasing penetration rates in terms of loading time, while higher RH levels (50 and 80%) have increasing penetration rates. Also, the loading of the filter is normally accompanied with a shift of MPPS towards larger sizes.

Does kidney transplantation with multiple arteries affect graft survival?

INTRODUCTION

We compared short- and long-term outcomes of renal transplants with single versus multiple arteries.

PATIENTS AND METHODS

We retrospectively analyzed data from kidney transplants from 208 living donors performed between 1994 and 2010. Renal grafts were divided into two groups: single renal artery (n = 164) versus multiple renal arteries (n = 44). The groups were compared regarding early and late vascular and urological complications. Patient and graft survivals were compared using Kaplan-Meier survivorship curves with comparisons using the log-rank test.

RESULTS

Both groups were comparable regarding acute rejection episodes, posttransplant hypertension, postsurgery renal artery stenosis, and urologic complications. Only hemorrhagic complications and renal artery thrombosis were significantly higher in the multiple renal arteries group (P = .027 and .03, respectively). Warm ischemia time was significantly longer in the multiple renal arteries group without any influence on the incidence of acute tubular necrosis (P = .2). Mean creatinine clearance at 1 year was 65 versus 50 mL/min/1.73 m(2) (P = .5) and at 5 years, 60 versus 55 mL/min/1.73 m(2) (P = .1) for the single versus multiple renal arteries groups, respectively. Return to hemodialysis was necessary for 18.8% of the single and 16.1% of the multiple renal arteries group.

CONCLUSION

The use of an allograft with multiple renal arteries is a safe, successful surgical procedure, that does not influence patient or graft survivals or increase surgical complication rates provided the surgical team is evolved with technical skill.

Relation between male obesity and male infertility in a Tunisian population

Obesity is associated with significant disturbance in the hormonal milieu that can affect the reproductive system. Male infertility affects approximately 6% of reproductive-aged men. It has been suggested that overweight men or men with obese body mass index (BMI) experience prolonged time to pregnancy, although the influence of male BMI on fertility remains understudied. We hypothesised that BMI is inversely correlated with fertility, manifested by reduced sperm concentration and varicocele. Males of mean age 32.74 ± 6.96 years with semen analyses and self-reported BMI were included (n = 98). Patient parameters analysed included age, BMI, pubertal timing, the development of varicocele, and leutinizing hormone, follicle-stimulating hormone and testosterone (n = 18). The mean age of the study population was 32.74 ± 6.96 years. The incidence of azospermia, oligozoospermia, normospermia and the development of varicocele did not vary across BMI categories. Male obesity is not associated with the incidence of sperm concentration and the development of varicocele.

The need for a comprehensive approach to managing confined space entry: summary of the literature and recommendations for next steps

Despite all the regulatory and standard-setting efforts that have been made in North America, judging from the most recent statistics many fatal incidents related to work in confined spaces still occur. In Canada, fatal incidents in the province of Quebec reveal failures in and absence of the identification and preparation of work situations in confined spaces and in risk management. In this study, we performed a literature review consisting of 77 documents on existing hazards and risk assessment for confined spaces. Moreover, we formulated proposals regarding the design of specific and improved tools for assessing such risks. We found that atmospheric hazards monopolized attention in the literature on confined spaces, while risk estimation specific to confined space interventions received little practical coverage overall, apart from atmospheric hazards. The parameters used to establish classes or groupings of confined spaces in existing tools were imprecise. The development of a risk analysis process that is (i) more systematic and based on the concepts recognized in risk management standards, (ii) multidisciplinary, and (iii) adapted to the specific characteristics of confined spaces is therefore needed. Such a process will better support managers and occupational health and safety (OH&S) personnel in their efforts to prioritize and reduce risks. Suggestions on such a risk analysis tool and categorization of interventions in confined spaces are proposed in this article. Lastly, risk analysis tools adapted to confined space interventions are needed to ensure the inherently safe design of these spaces.

Contribution of breathing frequency and inhalation flow rate on performance of N95 filtering facepiece respirators

The investigation of particle penetration through filtering facepiece respirators under cyclic flows is very necessary because cyclic flows represent actual breathing flow patterns. This article reports the development of a procedure to investigate the individual impact of breathing frequency and flow rate on the performance of N95 filtering facepiece respirators. Experiments were performed for two peak inhalation flows (PIFs; 135 and 360 l min(-1)) and two breathing frequencies [24 and 42 breaths per minute (BPM)] for a total of four cyclic flows (Flow A: 135 l min(-1) and 24 BPM; Flow B: 135 l min(-1) and 42 BPM; Flow C: 360 l min(-1) and 24 BPM; and Flow D: 360 l min(-1) and 42 BPM). Each experiment was performed using two different set-ups: the first set-up included both inhalations and exhalations through the filter media and test chamber, while with the second set-up, only inhalation flows were considered. The results showed that, for the most penetrating particle size range, an increase in both PIF and breathing frequency could potentially enhance the penetration with both set-ups; however, the effect of PIF was observed to be much more pronounced than that of frequency. The results indicated that with both set-ups, when the PIF was increased from 135 to 360 l min(-1) (for the given frequency: 24 or 42 BPM), an increase of up to 139-152% in penetration was observed. On the other hand, only a 10-16% increase in penetration occurred when the frequency was changed from 24 to 42 BPM (for a given PIF: 135 or 360 l min(-1)). This suggests that, from low to high respiratory efforts, a huge portion of penetration enhancement is due to PIF variations and only a small portion is contributed by frequency variations.

Primary renal angiosarcoma: Case report and literature review

Angiosarcoma is a rare malignant tumour occurring in less than 2% of soft tissue sarcomas. Angiosarcoma involving the kidney usually represents metastasis from skin or visceral primary lesions, while angiosarcoma primarily occurring in the kidney is a very rare neoplasm. We report a case of angiosarcoma of the right kidney in a 59-year-old male. The computed tomography scan showed a solid tumour with a low increased density after administration of contrast medium. Histological examination of the piece of nephrectomy confirmed the diagnosis.