Characterization of Gaseous and Particulate Phase Polycyclic Aromatic Hydrocarbons Emitted During Preharvest Burning of Sugar Cane in Different Regions of Kwa-Zulu Natal, South Africa.

Biomass burning is a significant anthropogenic source of air pollution, including the preharvest burning of sugar cane. These burn events result in atmospheric emissions, including semivolatile organic compounds, that may have adverse impacts on air quality and human health on a local, regional, and even a global scale. Gaseous and particulate polycyclic aromatic hydrocarbon (PAH) emissions from various sugar cane burn events in the province of Kwa-Zulu Natal in South Africa were simultaneously sampled using a portable denuder sampling technology, consisting of a quartz fiber filter sandwiched between two polydimethylsiloxane multichannel traps. Total gas and particle phase PAH concentrations ranged from 0.05 to 9.85 µg m-3 per individual burn event, and nine PAHs were quantified. Over 85% of all PAHs were found to exist in the gas phase, with smaller two- and three-ring PAHs, primarily naphthalene, 1-methyl naphthalene, and acenaphthylene, being the most dominant and causing the majority of variance between the burn sites. The PAH profiles differed between the different burn events at different sites, emphasizing the significant influence that the crop variety, prevailing weather conditions, and geographical location has on the type and number of pollutants emitted. The potential carcinogenicity of the PAH exposure was estimated based on toxic equivalency factors that showed varying risk potentials per burn event, with the highest value of 5.97 ng m-3 . Environ Toxicol Chem 2023;42:778-792. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Associations of Maternal Complaints to Levator Ani Muscle Trauma within 9 Months after Vaginal Birth: A Prospective Observational Cohort Study.

Introduction: Pelvic floor trauma in the form of partial or complete avulsions of the levator ani muscle (LAM) affects 6-42% of women after vaginal birth and can cause tremendous long-term morbidity. Many studies assessed morphological pelvic floor trauma after childbirth but lacked to evaluate women's associated short-term complaints. A proper assessment of trauma and subjective complaints after birth could help to assess possible associations between them and their relevance to women's daily life. Therefore, we aimed to assess women's complaints within the first months after birth in association to their LAM trauma. Materials and Methods: Between 3/2017 and 4/2019, we prospectively evaluated vaginal births of 212 primiparous women with singletons in vertex presentation ≥ 36 + 0 gestational weeks for levator ani muscle (LAM) trauma by translabial ultrasound, for pelvic organ prolapse by clinical examination, and for urogynecological complaints using questionnaires 1-4 days (P1), 6-10 weeks (P2), and 6-9 months (P3) after birth. The questionnaires were self-designed but oriented to and modified from validated questionnaires. Women's complaints were evaluated for P1-P3 according to their LAM trauma state. Results: At P1, 67% of women showed an intact LAM, whereas 14.6% presented a hematoma, 6.6% a partial avulsion (PAV), and 11.8% a complete avulsion (CAV). At P2, 75.9% showed an intact LAM, 9.9% a PAV, and 14.2% a CAV. At P3, 72.9% of women with a LAM trauma in P1 and/or P2 were assessed with 21.6% being intact and 39.2% having a PAV and CAV, respectively. Obstetrical and baseline characteristics differed slightly between the groups. When comparing the time before and during pregnancy with the time after childbirth, birth itself affected women's complaints in all LAM state groups, but the presence of a LAM trauma, especially a CAV, had more negative effects. Conclusions: Vaginal birth changes the anatomical structure of the maternal birth canal and genital tract, and it alters women's perceptions and body function. In our study, LAM trauma did not change these effects tremendously within the first months. Therefore, other maternal, fetal, and obstetrical factors need consideration for the explanation of maternal complaints, in addition to long-term effects of trauma and dysfunction of the LAM and other birth canal structures.

[Improved quality of stored packed red blood cells by mechanical rinsing]. / Verbesserte Qualität gelagerter Erythrozytenkonzentrate durch maschinelle Autotransfusion.

BACKGROUND: The transfusion of packed red blood cells (PRBC) is associated with various side effects, including storage damage to PRBCs. The cells change their structure, releasing potassium as well as lactate. Mechanical rinsing, available in many hospitals, is able to remove toxic substances and possibly minimizes the negative side effects of transfusion. OBJECTIVE: The primary aim of our study was to improve the quality of PRBCs before transfusion. The effects of different washing solutions on PRBC quality were analyzed. MATERIAL AND METHODS: This in vitro study compares 30 mechanically washed PRBCs. They were either processed with standard normal saline 0.9% (n = 15, N group) or a hemofiltration solution containing 4 mmol/l potassium (n = 15, HF group) by a mechanical rinsing device (Xtra, LivaNova, Munich, Germany). A subgroup analysis was performed based on the storage duration of the processed PRBCs (7, 14, 37 days). Samples were taken before washing (EKprä), immediately after washing (EKpost) and 10 h later (EKpost10h), after storage in the "wash medium" at room temperature. Concentrations of ATP (probability of survival in transfused erythrocytes), lactate, citrate and electrolytes (potassium, sodium, chloride, calcium) were tested. RESULTS AND CONCLUSION: Mechanical rinsing improves pretransfusion quality of PRBC. Washing with a hemofiltration solution results in a more physiological electrolyte composition. Even 10 h after mechanical rinsing with a hemofiltration solution, the quality of 37-day-old PRBC is comparable to young PRBC that have been stored for 7 days and have not been washed. Washing stored PRBC increases the ATP content, which subsequently leads to an increased probability of survival of red cells after transfusion.

Simultaneous on-line vacuum single- and multi-photon ionization on an orthogonal acceleration time-of-flight mass spectrometer platform.

The development of orthogonal acceleration time-of-flight (oa-tof) technology is driven forward due to higher mass accuracy and resolving power than conventional linear/reflectron tof instruments. This is achieved with a more accurate definition of starting energies and coordinates of ions by spatial separation of ion generation and orthogonal ion extraction. Consequently, the ability to cover the whole mass spectral range without scanning is not given anymore. Therefore, continuous ion sources are favored for ensuring high duty cycles and thus high temporal resolution. For pulsed ion sources, high repetition rates are mandatory for covering large m/z ranges without losing their high temporal resolution. We have combined an oa-tof with deuterium lamp single-photon ionization (SPI) as a continuous ion source together with a pulsed 2000 Hz excimer (KrF) laser for resonance enhanced multi-photon ionization (REMPI). These two ionization techniques can be used simultaneously. To the best of our knowledge, this system is the first of its kind in combining a vacuum pulsed ionization source with an oa-tof instrument without any other ion storage hardware. The combination of a soft broadband ionization for organics (SPI) in combination with a very sensitive and selective soft ionization (REMPI) can be used for covering the whole mass range or in targeted on-line monitoring cases one or several smaller mass ranges. To demonstrate the simultaneous SPI/REMPI-oa-tof technique, two applicative areas are explored: on-line monitoring of coffee roast gas emissions and e-cigarette vapor. The complementary information from SPI and REMPI signals are combined in a way to exploit the advantages of both ionization types. In a further development step, a second data acquisition card is built into the system. This modification allows the independent storage of data from both ionization methods without mixing. For demonstration, a third example with a GC measurement is provided. The last example shows the possibility of modified sensitivities for different mass regions in REMPI data acquisition without affecting the SPI channel. The newly developed system shows high robustness in terms of measurements in real industrial environments. The simultaneous measurement technique provides a higher density of information in a single measurement, saving time and resources.

Residues of the minimal sequence of G0S2 collectively contribute to ATGL inhibition while C-and N-terminal extensions promote binding to ATGL.

The protein encoded by the G0/G1 switch gene 2 (G0S2) is a potent inhibitor of adipose triglyceride lipase (ATGL) and thus an important regulator of intracellular lipolysis. Since dysfunction of lipolysis is associated with metabolic diseases including diabetes and obesity, inhibition of ATGL is considered a therapeutic strategy. G0S2 interacts with ATGL's patatin-domain to mediate non-competitive inhibition, however atomic details of the inhibition mechanism are incompletely understood. Sequences of G0S2 from higher organisms show a highly conserved N-terminal part, including a hydrophobic region covering amino acids 27 to 42. We show that predicted G0S2 orthologs from platypus, chicken and Japanese rice-fish are able to inhibit human and mouse ATGL, emphasizing the contribution of conserved amino acid to ATGL inhibition. Our site directed mutagenesis and truncation studies give insights in the protein-protein interaction on a per-residue level. We determine that the minimal sequence required for ATGL inhibition ranges from amino acids 20 to 44. Residues Y27, V28, G30, A34 G37, V39 or L42 within this sequence play a substantial role in ATGL inhibition. Furthermore, we show that unspecific interactions of the N-terminal part (amino acids 20-27) of the minimal sequence facilitate the interaction to ATGL. Our studies also demonstrate that full-length G0S2 shows higher tolerance to specific single amino acid exchanges in the hydrophobic region due to the stronger contributions of unspecific interactions. However, exchanges of more than one amino-acid in the hydrophobic region also result in the loss of function as ATGL inhibitor even in the full-length protein.

Association of uterine activity and maternal volatile anesthetic exposure during open fetal surgery for spina bifida: a retrospective analysis.

BACKGROUND: Recent warnings postulate a possible damaging effect of volatile anesthetics on the fetus. In our archive of fetal surgeries, we found wide variation in dosing of volatile anesthetics during spina bifida surgeries. We hypothesized that there was an association between volatile anesthetic exposure and uterine activity. METHODS: Sixty anesthesia records from spina bifida operations were assessed. We analyzed the course of the administered volatile anesthetic during surgery and calculated from each patient's anesthesia record the volatile anesthetic exposure expressed in vol%h. We divided the records into two post hoc groups of the 20 lowest exposure (Group L) versus the 20 highest exposure (Group H), and compared them for uterine activity and fetal heart rate. RESULTS: The number of contractions per hour was significantly greater in Group H (mean 1.3, SD ±â€¯1.2) compared with Group L (mean 0.5, SD ±â€¯0.6, P=0.049). There was no difference between the groups for the administration of the tocolytic drug atosiban (P=0.29). The course of the mean arterial pressure did not significantly differ but group H needed significantly more vasoactive medication (P <0.05). CONCLUSIONS: We found that a lower intra-operative volatile anesthetic exposure than recommended in the MOMS-trial (i.e. <2.0 minimum alveolar concentration [MAC]) was not associated with an increase in intra-operative uterine activity. This is an indication that during spina bifida surgery, 2.0 MAC may not be necessary to avoid potentially harmful uterine activity.

Systematic classification of maternal and fetal intervention-related complications following open fetal myelomeningocele repair - results from a large prospective cohort.

OBJECTIVE: To systematically categorise all maternal and fetal intervention-related complications after open fetal myelomeningocele (fMMC) repair of the first 124 cases operated at the Zurich Centre for Fetal Diagnosis and Therapy. DESIGN: A prospective cohort study. SETTING: Single centre. POPULATION: Mothers and fetuses after fMMC repair. METHODS: Between 2010 and 2019, we collected and entered all maternal complications following fMMC repair into the Clavien-Dindo classification. For fetal complications, a classification system based on the Medical Dictionary for Regulatory Activities terminology of Adverse Events was used including the preterm definitions of the World Health Organization. MAIN OUTCOME MEASURES: Systematic classification of maternal and fetal complications following fMMC repair. RESULTS: Gestational ages at surgery and birth were 25.0 ± 0.8 and 35.4 ± 2.0 weeks, respectively. In 17% of all cases, no maternal complications occurred. Maternal intervention-related complications were observed as follows: 69% grade 1, 36% grade 2, 25% grade 3, 6% grade 4 and 0% grade 5. In 34%, no fetal complications were noted; however, 43% of the fetuses developed a grade 1, 14% a grade 2, 8% a grade 3, 2% a grade 4 and 2% a grade 5 complication. CONCLUSION: This study raises awareness of complications following open fMMC repair; 6% of mothers and 2% of fetuses experienced a severe complication (grade 4) and perinatal death rate of 2% was observed (grade 5). These data are useful for prenatal counselling, they help to improve the system of fetal surgical care, and they allow benchmarking with other centres as well as comparison with fetoscopic approaches. TWEETABLE ABSTRACT: Systematic classification of all maternal and fetal intervention-related complications following open fMMC repair.

The civil society monitoring of hepatitis C response related to the WHO 2030 elimination goals in 35 European countries.

BACKGROUND: People who inject drugs (PWID) account for the majority of new cases of hepatitis C virus (HCV) infection in Europe; however, HCV testing, and treatment for PWID remain suboptimal. With the advent of direct acting antivirals (DAAs) the World Health Organization (WHO) adopted a strategy to eliminate HCV as public health threat by 2030. To achieve this, key policies for PWID must be implemented and HCV continuum of care needs to be monitored. This study presents results of the first monitoring led by civil society that provide harm reduction services for PWID. METHODS: In 2019, harm reduction civil society organizations representing focal points of Correlation-European Harm Reduction Network in 36 European countries were invited to complete a 27-item online survey on four strategic fields: use/impact of guidelines on HCV testing and treatment for PWID, availability/functioning of continuum of care, changes compared to the previous year and, the role of harm reduction services and non-governmental organizations (NGOs) of PWID. A descriptive analysis of the responses was undertaken. RESULTS: The response rate was 97.2%. Six countries reported having no guidelines on HCV treatment (17.1%). Twenty-three (65.7%) reported having treatment guidelines with specific measures for PWID; guidelines that impact on accessibility to HCV testing/treatment and improve access to harm reduction services in 95.6% and 86.3% of them, respectively. DAAs were available in 97.1% of countries; in 26.4% of them they were contraindicated for active drug users. HCV screening/confirmatory tests performed at harm reduction services/community centers, prisons and drug dependence clinics were reported from 80.0%/25.7%, 60.0%/48.6%, and 62.9%/34.3% of countries, respectively. Provision of DAAs at drug dependence clinics and prisons was reported from 34.3 to 42.9% of countries, respectively. Compared to the previous year, HCV awareness campaigns, testing and treatment on service providers' own locations were reported to increase in 42.9%, 51.4% and 42.9% of countries, respectively. NGOs of PWID conducted awareness campaigns on HCV interventions in 68.9% of countries, and 25.7% of countries had no such support. CONCLUSION: Further improvements in continuum-of-care interventions for PWID are needed, which could be achieved by including harm reduction and PWID organizations in strategic planning of testing and treatment and in efforts to monitor progress toward WHO 2030 elimination goal.

Implications of a change in case definition and screening of asylum seekers for hepatitis B surveillance in Germany in 2015 and 2016.

Since 2015, the number of hepatitis B virus (HBV) cases increased substantially in Germany. In 2015, a more sensitive HBV case definition was introduced. This coincided with an asylum seeker influx with differing screening strategies. Information on the asylum seeker status has been collected since 09/2015. We investigated this increase to interpret HBV notification data in Germany. We compared HBV surveillance data from 2010-2013 (baseline) with 2015-2016, excluding 2014 due to beginning of asylum seeker influx. We estimated the excess above the mean case number (baseline) using Poisson regression and compared asylum seeker cases and the excess of cases with the unknown asylum seeker status. HBV cases increased from 1855 (mean baseline) to 3873 (2015) and 3466 (2016) with 1903 asylum seeker cases and 1099 excess-cases with the unknown asylum seeker status in 2015-2016. Cases only fulfilling the changed case definition increased from 60% (1119) in baseline to 81% (P < 0.01) in 2015-2016; 69% of asylum seeker cases and 61% of excess-cases were males <40 years compared to 27% (baseline) (P < 0.01). Changed case definition increased the number of cases in official statistics substantially. Demographic and geographical distributions suggest that screening of asylum seekers increased the case numbers even to a higher extent than surveillance data indicates.

Evaluation of the German surveillance system for hepatitis B regarding timeliness, data quality, and simplicity, from 2005 to 2014.

OBJECTIVES: Germany has a mandatory surveillance system for acute hepatitis B (AHB) with the Protection against Infection Act as the legal basis in place since 2001. An amendment was introduced in 2013. We aimed at evaluating the surveillance systems' performance regarding timeliness, data quality, and simplicity from 2005 to 2014 and at assessing the effect of the amendment on timeliness of AHB surveillance. STUDY DESIGN: This study is a trend analysis of surveillance data. METHODS: Aspects of simplicity versus complexity of the surveillance system were assessed by describing data flow, levels of reporting, and data management procedures. Data quality, in terms of data completeness, was evaluated by quantitative indicators, and timeliness was measured in days between different levels of the surveillance system, notification delay, and reporting delay. Trends over time in data quality were analyzed by logistic regression, while negative binomial regression was used to test for trend over time regarding mean notification and reporting delay. RESULTS: Between January 2005 and December 2014, a total of 22,549 AHB infections were reported at the national level. The data flow of the German AHB surveillance system showed structural characteristics of a complex system. Over the 10-year period, completeness of reporting sex, age, probable route of transmission, and hepatitis B virus (HBV) vaccination were 99%, 100%, 25%, and 73%, respectively. However, data quality decreased over the evaluation period. Although notification delay improved over time (incident rate ratio [IRR] = 0.95, 95% confidence interval [CI] = 0.95-0.96; P < 0.05), reporting delay improved only since the amendment (IRR = 0.76, 95% CI = 0.70-0.82; P < 0.05). In total, mean notification and reporting delay were 3.0 days and 14.3 days, respectively. CONCLUSIONS: The German AHB surveillance system is operating in a timely manner. Although timeliness improved over the evaluation period and the amendment to the Protection against Infection Act succeeded in reducing reporting time, data quality in terms of completeness of information decreased considerably. As improved data completeness is required to adequately design prevention activities, reasons for this decrease should further be explored.

Influence of oxytocin receptor single nucleotide sequence variants on contractility of human myometrium: an in vitro functional study.

BACKGROUND: Oxytocin receptor (OXTR) gene variants have been shown to affect the prevalence of preterm birth, mode of delivery and oxytocin (OXT) requirements for labor induction and augmentation. We hypothesized that this might be associated with different myometrium responses to oxytocin. Our aim was to investigate the influence of a selection of eight OXTR gene single nucleotide variants on oxytocin-induced stimulation of human myometrium contractility in vitro. METHODS: Human myometrium biopsies were collected during elective cesarean sections at term, if patients had given informed consent. Myometrial strips were submerged under tension in an organ bath and allowed to contract; the remaining material was stored at - 80 °C for further determination of relevant genetics and mRNA level. The area under the curve (AUC) of all contractions taking place in the absence of OXT and of those occurring upon OXT addition (for 30 min each) was measured. OXT stimulation, defined as the ratio between AUC measurements after OXT addition and those in the absence of OXT was calculated for each strip. TaqMan™ Assays were used to detect the allele distribution of the eight OXTR variants and to determine the relative amounts of OXTR-mRNA in the samples. For each variant, oxytocin stimulation of contractility was compared between samples homozygous for the reference allele (reference group) and samples with at least one variant allele (variant group) by linear regression. RESULTS: Sixty samples were included in the present study. For rs1042778, rs11706648, rs4686301, rs53576, rs237895, and rs237902, OXT stimulation was similar in the reference and in the variant groups. However, the values of OXT stimulation differed significantly between the reference and the variant groups for rs4686302 (3.1 vs. 4.1 times; p = 0.022) and rs237888 (3.2 vs. 5.5 times; p = 0.001). No significant differences between the levels of OXTR-mRNA in the various reference and corresponding variant groups were detected. CONCLUSIONS: Patients with variant alleles of rs237888 and/or rs4686302 may be more sensitive to oxytocin stimulation, explaining why these sequence variants have been associated with lower cesarean section prevalence and premature birth, respectively.

[Optimizing training in limited obstetric ultrasound for midwives through a combination of e-learning and simulation]. / E-learning et simulation en échographie focalisée pour la formation continue des sages-femmes en salle de naissance.

OBJECTIVE: To evaluate a training program in limited obstetric ultrasound, combining e-learning and simulation. METHODS: This a descriptive cohort study in Single-center study conducted in a French university hospital. Thirty-three practicing midwives who had not received basic training in ultrasonography had unlimited access to an e-learning platform offering interactive theoretical instruction modules. Then, they attended a one-day simulator-based obstetric ultrasound workshop. A theoretical competency test was taken before the e-learning component (T1), then before (T2) and after (T3) the simulation workshop. Their competency in specific practical tasks was assessed before and after the workshop. A learner satisfaction questionnaire was completed after the program. RESULTS: The mean score obtained in the theoretical competency test was 46.6% (range 8.3-83.3%) at T1, 87.2% (66.6-100%) at time T2, and 91.6% (66.6-100%) at T3. Significant improvements were observed between times T1 and T2 (P<0.001) or T3 (P<0.001), as well as in the performance of certain practical tasks, such as placental location (P=0.02) and visualization of the cervix (P=0.03). The mean number of logins to the e-learning platform during the program was 11.2 per participant (6-24). Most participants were satisfied with the training and reported an improvement in their daily practice. CONCLUSION: Training in limited obstetric ultrasound, combining e-learning to acquire theoretical knowledge and a hands-on simulation workshop, appears to meet the needs of practicing midwives. Most participants were satisfied with the proposed teaching and the rapid acquisition of ultrasound skills applicable to their clinical practice.

Cone-beam computed tomography of the head in standing equids.

BACKGROUND: Computed tomography in standing horses has revolutionized diagnostic imaging. The O-arm®, a cone beam computed tomography (CBCT) scanner with a gantry opening of 96.5 cm is routinely used for image-guided spine and neurosurgery in humans. The aim of this study is to describe the set-up and first experiences using the O-arm® to achieve CBCT imaging of the head in standing horses. CT imaging of the predefined region of interest (ROI) was tested on 2 cadaveric heads, concentrating on centering issues within the gantry, as well as determining the number of scans needed per ROI. All horses presented with head-related diseases and subjected to a CBCT examination between February 2015 and November 2016 for CBCT were included. Per scan, a limited field of view, i.e. a cylindrical volume of 21 cm in diameter and 16 cm in height was acquired within 13 s. Depending on the dimensions of the ROI, the minimum number of scans could range from one to six, if the entire equine head is to be examined in an adult horse. RESULTS: Sixty-eight horses were included, five of which had a follow-up CBCT exam, and two of which were presented twice for two different indications (75 clinical cases). A total number of 449 acquired three-dimensional (3D) scans were recorded for these 75 cases. Two-hundred and forty-two 3D scans (54%) were considered as diagnostic quality. The imaging procedure was generally well tolerated by the sedated, standing equid, and diagnostic studies were performed in 73 out of 75 cases (97.3%). Motion artefacts and inadequate centering of the ROI were the most common reasons for non-diagnostic quality images and repeat scans of the same ROI. CONCLUSIONS: CBCT is a valuable imaging modality for the equine head. Advantages of the O-arm® compared to a conventional multi-slice helical CT for imaging of the head in standing equids include the rapid image acquisition, the gantry's mobility in all dimensions, and the free movability of the entire imaging unit. Disadvantages include the considerable sensitivity to motion artefact, increased scatter, low soft tissue contrast and the limited dimensions of the field of view.

Blood group O: A novel risk factor for increased postpartum blood loss?

INTRODUCTION: Blood group O is known to be associated with lower levels of von Willebrand factor (VWF) and with increased bleeding complications. The influence of blood group O on postpartum blood loss was assessed by a few studies, however, without adjustment for important obstetric risk factors for postpartum blood loss. AIM: Aim of this study was to investigate whether women with blood group O exhibit increased blood loss after delivery in consideration of established risk factors for postpartum bleeding. METHODS: A total of 1487 patients were prospectively included into this cohort study. Blood loss was assessed by estimated blood loss (in mL), and drop of haemoglobin (Δ haemoglobin) was calculated. Association of blood loss with risk factors (such as blood group O, cervical tears, morbidly adherent placenta, placenta praevia and uterine atony amongst others) was assessed with appropriate tests. Significant variables were entered into a stepwise multivariate regression analysis. RESULTS: Women with blood group O showed a significantly higher blood loss when compared to women with blood group non-O (529.2 mL ± 380.4 mL and 490.5 mL ± 276.4 mL, respectively, P = .024)). The increased blood loss in women with blood group O remained significant after multivariate regression analysis (difference 47 mL, P = .019). CONCLUSION: This is the first study reporting significantly increased blood loss following delivery in women with blood group O after adjustment for major risk factors for postpartum blood loss. Albeit having a statistically significant, but clinically minor effect on absolute blood loss, blood group O carriers may suffer from aggravated bleeding in the presence of additional obstetric bleeding pathologies.

Trace Metals in Soot and PM2.5 from Heavy-Fuel-Oil Combustion in a Marine Engine.

Heavy fuel oil (HFO) particulate matter (PM) emitted by marine engines is known to contain toxic heavy metals, including vanadium (V) and nickel (Ni). The toxicity of such metals will depend on the their chemical state, size distribution, and mixing state. Using online soot-particle aerosol mass spectrometry (SP-AMS), we quantified the mass of five metals (V, Ni, Fe, Na, and Ba) in HFO-PM soot particles produced by a marine diesel research engine. The in-soot metal concentrations were compared to in-PM2.5 measurements by inductively coupled plasma-optical emission spectroscopy (ICP-OES). We found that <3% of total PM2.5 metals was associated with soot particles, which may still be sufficient to influence in-cylinder soot burnout rates. Since these metals were most likely present as oxides, whereas studies on lower-temperature boilers report a predominance of sulfates, this result implies that the toxicity of HFO PM depends on its combustion conditions. Finally, we observed a 4-to-25-fold enhancement in the ratio V:Ni in soot particles versus PM2.5, indicating an enrichment of V in soot due to its lower nucleation/condensation temperature. As this enrichment mechanism is not dependent on soot formation, V is expected to be generally enriched within smaller HFO-PM particles from marine engines, enhancing its toxicity.

Magnetic nanocomposites based on phosphorus-containing polymers-structural characterization and thermal analysis.

Fabrication of magnetic nanocomposites containing iron oxide nanoparticles formed in situ within a phosphorus-containing polymer matrix as well as its structural characterization and its thermal degradation is reported here. Comparative structural studies of the parent polymer and nanocomposites were performed using FTIR spectroscopy, x-ray diffraction, and atomic force microscopy. The results confirmed the presence of dispersed iron oxide magnetic nanoparticles in the polymer matrix. The formed composite combines the properties of porous polymer carriers and magnetic particles enabling easy separation and reapplication of such polymeric carriers used in, for example, catalysis or environmental remediation. Studies on thermal degradation of the composites revealed that the process proceeds in three stages while a significant influence of the embedded magnetic particles on that process was observed in the first two stages. Magnetic force microscopy studies revealed that nanocomposites and its calcinated form have strong magnetic properties. The obtained results provide a comprehensive characterization of magnetic nanocomposites and the products of their calcination that are important for their possible applications as sorbents (regeneration conditions, processing temperature, disposal, etc).

The surface chemistry of sapphire-c: A literature review and a study on various factors influencing its IEP.

A wide range of isoelectric points (IEPs) has been reported in the literature for sapphire-c (α-alumina), also referred to as basal plane, (001) or (0001), single crystals. Interestingly, the available data suggest that the variation of IEPs is comparable to the range of IEPs encountered for particles, although single crystals should be much better defined in terms of surface structure. One explanation for the range of IEPs might be the obvious danger of contaminating the small surface areas of single crystal samples while exposing them to comparatively large solution reservoirs. Literature suggests that factors like origin of the sample, sample treatment or the method of investigation all have an influence on the surfaces and it is difficult to clearly separate the respective, individual effects. In the present study, we investigate cause-effect relationships to better understand the individual effects. The reference IEP of our samples is between 4 and 4.5. High temperature treatment tends to decrease the IEP of sapphire-c as does UV treatment. Increasing the initial miscut (i.e. the divergence from the expected orientation of the crystal) tends to increase the IEP as does plasma cleaning, which can be understood assuming that the surfaces have become less hydrophobic due to the presence of more and/or larger steps with increasing miscut or due to amorphisation of the surface caused by plasma cleaning. Pre-treatment at very high pH caused an increase in the IEP. Surface treatments that led to IEPs different from the stable value of reference samples typically resulted in surfaces that were strongly affected by subsequent exposure to water. The streaming potential data appear to relax to the reference sample behavior after a period of time of water exposure. Combination of the zeta-potential measurements with AFM investigations support the idea that atomically smooth surfaces exhibit lower IEPs, while rougher surfaces (roughness on the order of nanometers) result in higher IEPs compared to reference samples. Two supplementary investigations resulted in either surprising or ambiguous results. On very rough surfaces (roughness on the order of micrometers) the IEP lowered compared to the reference sample with nanometer-scale roughness and transient behavior of the rough surfaces was observed. Furthermore, differences in the IEP as obtained from streaming potential and static colloid adhesion measurements may suggest that hydrodynamics play a role in streaming potential experiments. We finally relate surface diffraction data from previous studies to possible interpretations of our electrokinetic data to corroborate the presence of a water film that can explain the low IEP. Calculations show that the surface diffraction data are in line with the presence of a water film, however, they do not allow to unambiguously resolve critical features of this film which might explain the observed surface chemical characteristics like the dangling OH-bond reported in sum frequency generation studies. A broad literature review on properties of related surfaces shows that the presence of such water films could in many cases affect the interfacial properties. Persistence or not of the water film can be crucial. The presence of the water film can in principle affect important processes like ice-nucleation, wetting behavior, electric charging, etc.

A large proportion of people who inject drugs are susceptible to hepatitis B: Results from a bio-behavioural study in eight German cities.

BACKGROUND: People who inject drugs (PWID) are at high risk of hepatitis B virus (HBV) infection by sharing needles and drug use paraphernalia. In Germany, no routine surveillance of HBV prevalence and vaccination coverage among PWID exists. METHODS: Socio-demographic and behavioural data were collected between 2011 and 2014 through face-to-face interviews, during a bio-behavioural survey of PWID recruited in eight German cities. Dried blood spots (DBS) prepared with capillary blood were tested for HBV markers. Factors associated with past/current HBV infection and vaccination status were analysed by univariable and multivariable analysis using logistic regression. The validity of self-reported HBV infection and vaccination status was analysed by comparison to the laboratory results. RESULTS: Among 2077 participants, the prevalence of current HBV infection was 1.1%, of past HBV infection was 24%, and of vaccine-induced HBV antibodies was 32%. No detectable HBV antibodies were found in 43%. HBV infection status was significantly associated with study city, age, years of injecting, use of stimulants, migration status, and homelessness; HBV vaccination status was significantly associated with study city, age, and level of education. Correct infection status was reported by 71% and correct vaccination status by 45%. CONCLUSIONS: HBV seroprevalence among PWID was about five times higher than in the general population in Germany, confirming PWID as an important risk group. Targeted information campaigns on HBV and HBV prevention for PWID and professionals in contact with PWID need to be intensified. Routinely offered HBV vaccination during imprisonment and opioid substitution therapy would likely improve vaccination rates among PWID.