Incense powder and particle emission characteristics during and after burning incense in an unventilated room setting

Despite being a recognized health hazard, burning incense remains in widespread use. A number of studies have investigated the emissions of air pollulants from incense burning, but less attention has been given to particle decay following incense burning. We have studied the elemental composition and indoor emission characteristics of incense sticks in terms of the size distribution and concentrations of fine particles. The results of chemical analysis and energy dispersive X-ray spectroscopy showed that the primary constituents of the emissions were CaCO₃ and SiO₂, together with lesser amounts of Mg, K, Al, Fe, and Cl. Analysis using a scanning mobility particle sizer revealed that the maximum total particle concentration at the end of the burning period was up to 30-fold higher than that of the initial background levels and that it remained elevated even 100 min after the incense sticks had been completely burned up. Emitted incense particles decayed in a biexponential manner, with particles of up to 100 nm in size decaying with lifetimes of several tens of minutes, while nanoparticles with diameters of 100–700 nm having lifetimes of > 100 min, as their removal mechanisms are slower. The peak particle size immediately following the end of incense burning was 85 nm, and this increased to 110 nm at 100 min after completion of burning. This result indicates that a high proportion of emitted particles can be inhaled into the alveolar region of the lung, where the potential for adverse health effects is the greatest. These findings provide a more detailed insight into particle decay mechanisms under conditions of low ventilation, with implications for human health.     

Germline variation in the oxidative DNA repair genes NUDT1 and OGG1 is not associated with hereditary colorectal cancer or polyposis

The causal association of NUDT1 (=MTH1) and OGG1 with hereditary colorectal cancer (CRC) remains unclear. Here, we sought to provide additional evidence for or against the causal contribution of NUDT1 and OGG1 mutations to hereditary CRC and/or polyposis. Mutational screening was performed using pooled DNA amplification and targeted next‐generation sequencing in 529 families (441 uncharacterized MMR‐proficient familial nonpolyposis CRC and 88 polyposis cases). Cosegregation, in silico analyses, in vitro functional assays, and case–control associations were carried out to characterize the identified variants. Five heterozygous carriers of novel (n = 1) or rare (n = 4) NUDT1 variants were identified. In vitro deleterious effects were demonstrated for c.143G>A p.G48E (catalytic activity and protein stability) and c.403G>T p.G135W (protein stability), although cosegregation data in the carrier families were inconclusive or nonsupportive. The frequency of missense, loss‐of‐function, and splice‐site NUDT1 variants in our familial CRC cohort was similar to the one observed in cancer‐free individuals, suggesting lack of association with CRC predisposition. No OGG1 pathogenic mutations were identified. Our results suggest that the contribution of NUDT1 and OGG1 germline mutations to hereditary CRC and to polyposis is inexistent or, at most, negligible. The inclusion of these genes in routine genetic testing is not recommended.     

The impact of reconstruction algorithms and time of flight information on PET/CT image quality

Background

The aim of the study was to explore the influence of various time-of-flight (TOF) and non-TOF reconstruction algorithms on positron emission tomography/computer tomography (PET/CT) image quality.

Materials and methods.

Measurements were performed with a triple line source phantom, consisting of capillaries with internal diameter of ∼ 1 mm and standard Jaszczak phantom. Each of the data sets was reconstructed using analytical filtered back projection (FBP) algorithm, iterative ordered subsets expectation maximization (OSEM) algorithm (4 iterations, 24 subsets) and iterative True-X algorithm incorporating a specific point spread function (PSF) correction (4 iterations, 21 subsets). Baseline OSEM (2 iterations, 8 subsets) was included for comparison. Procedures were undertaken following the National Electrical Manufacturers Association (NEMA) NU-2-2001 protocol.

Results

Measurement of spatial resolution in full width at half maximum (FWHM) was 5.2 mm, 4.5 mm and 2.9 mm for FBP, OSEM and True-X; and 5.1 mm, 4.5 mm and 2.9 mm for FBP+TOF, OSEM+TOF and True-X+TOF respectively. Assessment of reconstructed Jaszczak images at different concentration ratios showed that incorporation of TOF information improves cold contrast, while hot contrast only slightly, however the most prominent improvement could be seen in background variability - noise reduction.

Conclusions

On the basis of the results of investigation we concluded, that incorporation of TOF information in reconstruction algorithm mostly affects reduction of the background variability (levels of noise in the image), while the improvement of spatial resolution due to incorporation of TOF information is negligible. Comparison of traditional and modern reconstruction algorithms showed that analytical FBP yields comparable results in some parameter measurements, such as cold contrast and relative count error. Iterative methods show highest levels of hot contrast, when TOF and PSF corrections were applied simultaneously.     

The specific NK cell response in concert with perforin prevents CD8<Superscript>+</Superscript> T cell-mediated immunopathology after mouse cytomegalovirus infection

Natural killer (NK) and CD8⁺ T cells play a crucial role in the control of mouse cytomegalovirus (MCMV) infection. These effector cells exert their functions by releasing antiviral cytokines and by cytolytic mechanisms including perforin activation. In addition to their role in virus control, NK cells play an immunoregulatory role since they shape the CD8⁺ T cell response to MCMV. To investigate the role of perforin-dependent cytolytic mechanism in NK cell modulation of CD8⁺ T cell response during acute MCMV infection, we have used perforin-deficient C57BL/6 mice (Prf1^?/?) and have shown that virus control by CD8⁺ T cells in Prf1^?/? mice is more efficient if NK cells are activated by the engagement of the Ly49H receptor with the m157 MCMV protein. A lack of perforin results in severe liver inflammation after MCMV infection, which is characterized by immunopathological lesions that are more pronounced in Prf1^?/? mice infected with virus unable to activate NK cells. This immunopathology is caused by an abundant infiltration of activated CD8⁺ T cells. The depletion of CD8⁺ T cells has markedly reduced pathohistological lesions in the liver and improved the survival of Prf1^?/? mice in spite of an increased viral load. Altogether, the results of our study suggest that a lack of perforin and absence of the specific activation of NK cells during acute MCMV infection lead to an unleashed CD8⁺ T cell response that is detrimental for the host.     

Mondor's disease affecting the superficial dorsal vein of the penis

A case of the thrombophlebitis of the superficial dorsal vein of the penis (Mondor's disease of the penis) is reported. Two possible causes have been identified: a urogenital infection and a muscular strain (strength training). The first one was probably the underlying cause, the second one triggered the disease.     

Determination of leucocyte subsets in human saliva by flow cytometry

ObjectiveValidation of a flow cytometry-based method for the determination of major leucocyte subsets [polymorphonuclear (PMN) cells, monocytes, T cells and B cells] in paraffin-stimulated whole human saliva.DesignSalivary leucocyte subsets were determined by four-colour flow cytometry in eight healthy volunteers on three consecutive days. Comparison of leucocyte subsets between saliva and whole blood was also performed. Day-to-day variability and intraclass correlation coefficients (ICC) were determined as indicators of assay reliability.ResultsIt was observed that PMN cells were the predominant cells in the saliva. Percentages of mononuclear cells ranged from 0.3% to 7.2%, with monocytes composing the highest percentage, followed by T cells and B cells. Regardless of high intra-individual day-to-day variability, proportions of leucocyte subsets did not significantly change over three measurements, and high ICCs were calculated for T cells and monocytes.ConclusionFlow cytometry can be used as non-invasive and reproducible method for the analysis of leucocyte subsets in human saliva. Further investigation of pathological and other conditions that have the potential to influence salivary leucocyte subsets is warranted.     

Impact of indoor residual spraying with lambda-cyhalothrin on malaria parasitemia and anemia prevalence among children less than five years of age in an area of intense, year-round transmission in Malawi

Little is known about the impact of indoor residual spraying (IRS) in areas with intense malaria transmission such as sub-Saharan Africa. In Malawi, IRS with lambda-cyhalothrin has been applied annually in an area of intense year-long transmission since 2007. We evaluated the impact of IRS on parasitemia and anemia prevalence in children less than five years of age by using a cross-sectional household survey conducted in 2009, six months after the second IRS spray round. We measured malaria parasitemia and anemia (hemoglobin level < 11 g/dL) in 899 children less than five years of age and used binomial regression to assess the impact of IRS by comparing children living in a household sprayed with IRS (direct IRS) with those in a household not sprayed with IRS, but in an IRS area (indirect IRS) and those living in a household not sprayed with IRS and not in an IRS area (no IRS). In the IRS area, 77% of households reported receiving IRS. Adjusting for bed net use, house construction, and socioeconomic status, we found that receiving direct IRS and indirect IRS were significantly associated with a 33% (95% confidence interval [CI] = 1-54%) and 46% (95% CI = 20-64%) reduction in parasitemia and a 21% (95% CI = 4-34%) and 30% (95% CI = 12-45%) reduction in anemia prevalence, respectively.     

Impact of Sandblasting on Morphology,Structure and Conductivity of Zirconia Dental Ceramics Material

Over the last decade, zirconia (ZrO₂)-based ceramic materials have become more applicable to modern dental medicine due to the sustained development of diverse computer-aided design/computer-aided manufacturing (CAD/CAM) systems. However, before the cementation and clinical application, the freshly prepared zirconia material (e.g., crowns) has to be processed by sandblasting in the dental laboratory. In this work, the impact of the sandblasting on the zirconia is monitored as changes in morphology (i.e., grains and cracks), and the presence of impurities might result in a poor adhesive bonding with cement. The sandblasting is conducted by using Al₂O₃ powder (25, 50, 110 and 125 µm) under various amounts of air-abrasion pressure (0.1, 0.2, 0.4 and 0.6 MPa). There has been much interest in both the determination of the impact of the sandblasting on the zirconia phase transformations and conductivity. Morphology changes are observed by using Scanning Electron Microscope (SEM), the conductivity is measured by Impedance Spectroscopy (IS), and the phase transformation is observed by using Powder X-Ray Diffraction (PXRD). The results imply that even the application of the lowest amount of air-abrasion pressure and the smallest Al₂O₃ powder size yields a morphology change, a phase transformation and a material contamination.     

Left ventricular diastolic function in diabetes mellitus type 2 patients: correlation with heart rate and its variability

Aims

To assess the prevalence of left ventricular diastolic dysfunction in a population of patients with type 2 diabetes mellitus; to determine correlation of diastolic dysfunction with heart rate and its variability.

Methods

The study included 202 patients with type 2 diabetes mellitus. Echocardiography was performed with special reference to diastolic function, and heart rate variability was analysed using standard deviation of normal RR intervals, root mean square of successive differences and percentage of successive R–R intervals greater than 50 ms (pNN 50 %) in a 24-h electrocardiogram recording.

Results

Diastolic dysfunction is present in 79 % of type 2 diabetes mellitus patients: grade 1 in 52 %, grade 2 in 26 % and grade 3 in 1 % of patients. The subjects with grade 1 diastolic dysfunction had a statistically significantly higher heart rate variability compared with those with grade 2 diastolic dysfunction (LSD, post hoc test, p = 0.001). In the group with diastolic dysfunction, grade 2 reduced heart rate variability was recorded in 83 % of patients (37 and 7 % for grade 1 and normal diastolic function). An increase in the severity of diastolic dysfunction was associated with decreased heart rate variability and increased heart rate.

Conclusion

Progression of diastolic dysfunction is associated with a significantly greater prevalence of reduced heart rate variability, which is accompanied by increased heart rate.