223 research outputs found
Chemical speciation of water-soluble ionic components in PM2.5 derived from peatland fires in Sumatra Island
We conducted a field study to characterize water-soluble ionic species in PM2.5 from peatland fires using ground-based samplings at fire sources and receptor sites in the Riau Province, Sumatra, Indonesia. We determined the concentrations of PM2.5 mass, water-soluble ions, and some chemical elements. Through PM2.5 field samplings at three peatland fire sources, we have shown that the mass fractions of typical peatland fire water-soluble ionic components tend to differ between peatland fire sources. Thus, our results indicate that PM2.5 source profiles of water-soluble ionic components for peatland fire must be selected with extreme caution if applied to a receptor model. From the viewpoint of ionic composition of each peatland fire sample, Cl− and NH4+ were consistently dominant anions and cations, respectively, for all peatland fire samples, i.e., NH4Cl was a consistently dominant component. Through field samplings of the ambient PM2.5 in Pekanbaru during peatland fire-induced haze and non-haze periods, we found differences in PM2.5 mass and total water-soluble ionic component concentrations between haze and non-haze samples. Four components, C2O42−, NO3−, SO42−, and NH4+, showed highly elevated levels during haze periods. Since these four ions are recognized as the major secondarily formed aerosol components, the increased total concentrations of water-soluble ionic components during haze periods can mainly be derived from the gas-to-aerosol conversion process. The ionic compositions of haze samples at receptor sites are obviously different from those at peatland fire source samples. In particular, NH4Cl, which is characteristic of peatland fire PM2.5 sources, is low at sites during haze periods
Chemical speciation of water-soluble ionic components in PM2.5 derived from peatland fires in Sumatra Island
We conducted a field study to characterize water-soluble ionic species in PM2.5 from peatland fires using groundbased samplings at fire sources and receptor sites in the Riau Province, Sumatra, Indonesia. We determined the
concentrations of PM2.5 mass, water-soluble ions, and some chemical elements. Through PM2.5 field samplings at
three peatland fire sources, we have shown that the mass fractions of typical peatland fire water-soluble ionic
components tend to differ between peatland fire sources. Thus, our results indicate that PM2.5 source profiles of
water-soluble ionic components for peatland fire must be selected with extreme caution if applied to a receptor
model. From the viewpoint of ionic composition of each peatland fire sample, Cl− and NH4+ were consistently
dominant anions and cations, respectively, for all peatland fire samples, i.e., NH4Cl was a consistently dominant
component. Through field samplings of the ambient PM2.5 in Pekanbaru during peatland fire-induced haze and
non-haze periods, we found differences in PM2.5 mass and total water-soluble ionic component concentrations
between haze and non-haze samples. Four components, C2O42−, NO3−, SO42−, and NH4+, showed highly
elevated levels during haze periods. Since these four ions are recognized as the major secondarily formed aerosol
components, the increased total concentrations of water-soluble ionic components during haze periods can
mainly be derived from the gas-to-aerosol conversion process. The ionic compositions of haze samples at receptor sites are obviously different from those at peatland fire source samples. In particular, NH4Cl, which is
characteristic of peatland fire PM2.5 sources, is low at sites during haze period
<ORIGINAL>A prospective randomized clinical study on the efficacy of CO_2 lasers on initial stage endodontics
The purpose of this study was to evaluate the clinical efficacy of the CO_2 laser in a prospective randomized trial. A total of 112 teeth in 112 patients, previously treated pulpectomy procedures were gathered and randomly divided into two groups composed of 56. Irradiation was performed on one group and non-irradiation forms of treatment were performed on the other group. On the first group of teeth, root canal enlargement was done and followed by exposure of the canal to a CO_2 laser light (5W, 200msec) using 3 cycles each at a rate of 15 seconds per cycle. The second group was not exposed to laser light following root canal enlargement. The laser was applied on the root canal for a controlled period of time. On the day following pulpectomy, a statistically significant (p < 0.05) fewer number of patients observed pain in the irradiation group compared to the non-irradiation group. The treatment times and the total treatment days in the irradiation group are shorter than in the non-irradiation group (p < 0.05). Multivariate analysis showed that the laser treatment was significantly associated with treatment times. This study shows that the degree of oral pain was greatly reduced in patients who underwent laser irradiation as compared to these who did not. Our study suggests that the use of laser treatment provide significant short-term improvement compared to conventional forms of treatment performed during pulpectomy
Separated pulsed laser deposition for nanostructured thin films
Abstract We have developed an alternative laser deposition technique for preparation of droplet-free thin films and fine particles. This separated pulsed laser deposition (SPLD) consists of an ablation chamber and a deposition chamber which are independently evacuated under different ambient gases. High quality ZnO films exhibiting both particle-free and uniform deposition were obtained such as at an ablation pressure of 5 mTorr (Ar) and a deposition pressure of 10 mTorr (O 2 ). It is shown that, when the bias voltage and magnetic field are simultaneously applied in the deposition chamber, the E × B drift motion of about 70 km/s over the substrates contributes to deposit the smooth and high quality films. XRD and optical transmittance for the deposited films were investigated to clarify the operating properties of the SPLD assisted by the electric field and magnetic field. This SPLD is a promising technique for preparation of films and nanostructured particles
Members of a novel gene family, Gsdm, are expressed exclusively in the epithelium of the skin and gastrointestinal tract in a highly tissue-specific manner
AbstractGasdermin (Gsdm) was originally identified as a candidate causative gene for several mouse skin mutants. Several Gsdm-related genes sharing a protein domain with DFNA5, the causative gene of human nonsyndromic hearing loss, have been found in the mouse and human genomes, and this group is referred to as the DFNA5–Gasdermin domain family. However, our current comparative genomic analysis identified several novel motifs distinct from the previously reported domain in the Gsdm-related genes. We also identified three new Gsdm genes clustered on mouse chromosome 15. We named these genes collectively the Gsdm family. Extensive expression analysis revealed exclusive expression of Gsdm family genes in the epithelium of the skin and gastrointestinal tract in a highly tissue-specific manner. Further database searching revealed the presence of other related genes with a similar N-terminal motif. These results suggest that the Gsdm family and related genes have evolved divergent epithelial expression profiles
Epidemiology of Pediatric Acute Encephalitis/Encephalopathy in Japan
We studied the etiology of pediatric acute encephalitis/encephalopathy (pAEE) using epidemiological data obtained from a nationwide survey in Japan. Two-step questionnaires were sent to the pediatric departments of hospitals throughout the country in 2007, querying the number of the cases during 2005-2006 as the first step, and asking for the details of clinical information as the second step. In all, 636 children with pAEE (age ≤ 15 years) were enrolled. For the known etiology of pAEE (63.5% of the total cases), 26 microbes and 2 clinical entities were listed, but the etiology of 36.5% remained unknown. Influenza virus (26.7%), exanthem subitum (12.3%), and rotavirus (4.1%) were the most common, and the incidence of pAEE peaked at the age of 1 year. This trend was common among all etiologies. Among the neurological symptoms observed at the onset of pAEE, seizures were observed more often in patients aged ≤ 3 years, although abnormal speech and behavior were also common in older children. Undesirable outcomes (death and neurological sequelae) occurred at high rates in patients with any known etiology other than mycoplasma. In conclusion, these findings provide comprehensive insight into pAEE in Japan
Original Article Hypoxically preconditioned human peripheral blood mononuclear cells improve blood flow in hindlimb ischemia xenograft model
Abstract: Transplantation of peripheral blood mononuclear cells (PBMNCs) is a promising therapeutic approach for the treatment of hindlimb ischemia. However, insufficient angiogenesis in ischemic hindlimb after cell transplantation reduces the importance and practicality of this approach. Previously, we demonstrated using mouse models that hypoxic preconditioning augmented the cellular functions of rodent PBMNCs, such as increased cell adhesion capacity and accelerated neovascularization in ischemic hindlimb. To test the clinical application of this therapeutic strategy in this study, we investigated whether the protocol of hypoxic preconditioning, which was established in a condition of 2% O 2 for 24 h, can be made available for human PBMNCs (hPBMNCs). In addition, we grafted preconditioned hPBMNCs in a hindlimb ischemia mouse model. Hypoxic preconditioning enhanced cell adhesion capacity and oxidative stress resistance in hPBMNCs. We also observed an up-regulation of platelet endothelial cell adhesion molecule-1 (PECAM-1) in hPBMNCs by hypoxic preconditioning. Furthermore, preconditioned hPBMNCs significantly recovered limb blood flow in ischemic mice after transplantation. These results indicate that our established preconditioning protocol is available for hPBMNCs to effectively reinforce multiple cellular functions. Taken together with our series of study, we believe that this simple but powerful therapeutic strategy will be helpful in curing patients with severe hindlimb ischemia
Electrical Conduction and Structure of Copper Atomic Junctions in the Presence of Water Molecules
We have investigated Cu atomic contacts in the presence of H2O both experimentally and theoretically. The conductance measurements showed the formation of H2O/Cu junctions with a fixed conductance value of around 0.1 G0 (G0 = 2e2/h). These structures were found to be stable and could be stretched over 0.5 nm, indicating the formation of an atomic or molecular chain. In agreement with the experimental findings, theoretical calculations revealed that the conductance of H2O/Cu junctions decreases in stages as the junction is stretched, with the formation of a H2O/Cu atomic chain with a conductance of ca. 0.1 G0 prior to junction rupture. Conversely, in the absence of H2O, the conductance of the Cu junction remains close to 1 G0prior to the junction rupture and abrupt conductance drop
Giant voltage-controlled magnetic anisotropy effect in a crystallographically strained CoFe system
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