Particle deposition indoors has received increasing attention recently because of increasing concern about the effects of particle exposure on human health. Deposition is a positive phenomenon from ...the perspective of human health, as deposited particles cannot be inhaled unless resuspended. There are studies showing strong correlation between the prevalence of biological-origin airborne particles and the prevalence of some specific sick building syndrome (Menzies et al., 1998; Teeuw et al., 1994). In the literature, the amount of research effort put on particle deposition indoors which is directly related to human health and microcontamination control is far less than the amount of research on deposition in small diameter tube/channel. This is a summary of the full-length version which will appear on the home page. The full-length paper aims to provide an up-to-date revision for both experiment and modeling on particle deposition indoors. This paper summarizes the experimental studies for particle deposition indoors for non-industrial environments. In section 2, 'Background', an overview of the different mechanisms of particle deposition, focusing on indoor environments is addressed. In section 3, 'Experimental Study Review', a survey of aerosol deposition experiments in small experimental chambers and real houses (or large-scale chambers) is presented. Detailed experimental measurements are addressed for the real house studies. The experimental techniques of particle generation, particle labeling and detection methods are discussed. Although the present paper focuses on experimental studies, it would be more complete to include some discussions on the modeling of the term particle eddy diffusivity and it is reviewed in section 4, 'Modeling Review'.
222-nm Far-UVC light is an emerging and promising tool for rapidly inactivating airborne pathogens. In this study, we experimentally evaluated the performance of a 222-nm Far-UVC upper-room ...disinfection system with a 15 W Far-UVC lamp in a full-scale chamber (11.9 m3). One gram-positive bacteria, namely Staphylococcus epidermidis and two gram-negative bacteria, namely Escherichia coli and Salmonella enterica were selected for the experiments. The aerosolized bacteria were injected into the chamber and exposed to 222-nm Far-UVC light. The first-order decay rates of indoor bioaerosols concentration with and without Far-UVC treatment were estimated. According to the results, the 222-nm Far-UVC induced decay rates of three bacteria were 0.0611 ± 0.003, 0.409 ± 0.048, and 0.474 ± 0.015 min−1, respectively. Besides, the UV susceptibility constants (Z-values) of these three bacteria were estimated as 0.157, 0.974, and 1.18 m2/J, respectively. The gram-positive bacteria, S. epidermidis, showed higher resistance to Far-UVC light as compared to the gram-negative bacteria, E. coli and S. enterica. In addition, a case study on airborne SARS-CoV-2 indoor transmission was simulated, and the infection risk of SARS-CoV-2 was compared using the Far-UVC and enhanced ventilation approaches. The results showed that both UV inactivation and ventilation approaches can significantly reduce the infection risk. More importantly, the Far-UVC may be a feasible and sustainable solution for reducing infection risk and improving indoor air quality.
•222-Far-UVC KrCl lamp was installed in the upper room of a full-scale chamber.•3 bacteria were selected to test the air disinfection performance of the Far-UVC.•The Far-UVC inactivated 99% airborne gram-negative bacteria around 10 min.•Infection risk of SARS-CoV-2 was evaluated for different engineering strategies.•Upper-room Far-UVC disinfects air effectively and is energy efficient.
The ability of a few soil microorganisms to convert insoluble forms of phosphorus to an accessible form is an important trait in plant growth-promoting bacteria for increasing plant yields. The use ...of phosphate solubilizing bacteria as inoculants increases the P uptake by plants. In this study, isolation, screening and characterization of 36 strains of phosphate solubilizing bacteria (PSB) from Central Taiwan were carried out. Mineral phosphate solubilizing (MPS) activities of all isolates were tested on tricalcium phosphate medium by analyzing the soluble-P content after 72
h of incubation at 30
°C. Identification and phylogenetic analysis of 36 isolates were carried out by 16S rDNA sequencing. Ten isolates belonged to genus
Bacillus, nine to genus
Rhodococcus, seven to genus
Arthrobacter, six to genus
Serratia and one each to genera
Chryseobacterium,
Delftia,
Gordonia and
Phyllobacterium. In addition, four strains namely,
Arthrobacter ureafaciens,
Phyllobacterium myrsinacearum,
Rhodococcus erythropolis and
Delftia sp. are being reported for the first time as phosphate solubilizing bacteria (PSB) after confirming their capacity to solubilize considerable amount of tricalcium phosphate in the medium by secreting organic acids. P-solubilizing activity of these strains was associated with the release of organic acids and a drop in the pH of the medium. HPLC analysis detected eight different kinds of organic acids, namely: citric acid, gluconic acid, lactic acid, succinic acid, propionic acid and three unknown organic acids from the cultures of these isolates. An inverse relationship between pH and P solubilized was apparent from this study. Identification and characterization of soil PSB for the effective plant growth-promotion broadens the spectrum of phosphate solubilizers available for field application.
Background:
The prevalence and natural history of Graves' orbitopathy (GO) are poorly documented.
Methods:
A large series of 346 patients with newly diagnosed and recent onset Graves' hyperthyroidism ...seen at a single (nontertiary referral) center over an 8-year period were enrolled in an observational prospective study and evaluated for GO activity and severity according to the EUGOGO (European Group on Graves' Orbitopathy) criteria. After excluding patients immediately treated for moderate-to-severe GO, patients undergoing total thyroidectomy or radioactive iodine treatment, and patients lost to follow-up, 237 patients were submitted to antithyroid drug (ATD) treatment, with ocular evaluation at 6, 12, and 18 months.
Results:
Among the whole cohort, at presentation 255 (73.7%) had no ocular involvement, 70 (20.2%) had mild and inactive GO, 20 (5.8%) had moderate-to-severe and active GO, and 1 (0.3%) had sight-threatening GO with dysthyroid optic neuropathy. Of the 237 patients who completed the 18-month follow-up during or after ATD treatment, 194 (81.9%) had no GO at baseline. Progression to moderate-to-severe GO occurred in 5 (2.6%) of these patients. Of the 43 (18.1%) patients with mild and inactive GO at baseline, 1 (2.4%) progressed to moderate-to-severe GO, and 25 (58.1%) experienced complete remission.
Conclusions:
Most patients with newly diagnosed Graves' disease have no ocular involvement. Moderate-to-severe and active GO or sight-threatening GO are rare at presentation and rarely develop during ATD treatment. Most patients (>80%) with no GO at baseline do not develop GO after an 18-month follow-up period. Remission of mild GO occurs in the majority of cases.
The analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented. Since the phase shift is zero for a unit-cell that supports ...an infinite wavelength, the physical size of the antenna can be arbitrary; the antenna's size is independent of the resonance phenomenon. The antenna's operational frequency depends only on its unit-cell and the antenna's physical size depends on the number of unit-cells. In particular, the unit-cell is based on the composite right/left-handed (CRLH) metamaterial transmission line (TL). It is shown that the CRLH TL is a general model for the required unit-cell, which includes a nonessential series capacitance for the generation of an infinite wavelength. The analysis and design of the required unit-cell is discussed based upon field distributions and dispersion diagrams. It is also shown that the supported infinite wavelength can be used to generate a monopolar radiation pattern. Infinite wavelength resonant antennas are realized with different number of unit-cells to demonstrate the infinite wavelength resonance
A full-size, experimental, ventilation ductwork was designed and set up to measure one-pass inactivation efficacies of a cold plasma installation under various practical environmental conditions. ...Five types of microorganisms, which are commonly associated with nosocomial infection, including Escherichia coli, Pseudomonas alcaligenes, Staphylococcus epidermidis, Micrococcus luteus and Serratia marcescens, were chosen and tests were conducted at four airstream velocities, ranging from 2 to 7 m/s, and two different relative humidity (R.H.) levels. The inactivation efficacies for the first three types of bacteria varied from 20% to 70%. It is interesting to note that the inactivation efficacy increased with velocity. No detectable inactivation effect was found for M. luteus and S. marcescens. The inactivation efficacy at 90% R.H. dropped to 10% of the value measured at 55% R.H. The negative ion intensities measured near the plasma installation were correlated with the airstream velocities. When compared with data from systems using conventional fibrous filters, the pressure drop measured across the plasma unit was very small. Our experiments showed that cold plasma technology has high potential to be used as an energy-efficient method for disinfection. Limitations of application are also discussed.
•Cold plasma was first tested for ventilation duct flow on a practical scale.•Cold plasma was effective against some gram positive and negative bacteria.•Negative ion intensity increased with airflow speed.•High humidity significantly reduces the inactivation efficacy.
Standard treatment of cutaneous leishmaniasis (CL) in Suriname entails three injections of pentamidine isethionate (PI) 4 mg/kg per injection in 7 days (7 day regimen). Compliance to treatment is low ...and may contribute to increasing therapy failure. A 3 day regimen, including 2 injections of 7 mg/kg in 3 days may increase compliance.
In a randomized, single-blinded non-inferiority trial conducted in Suriname, 84 CL patients received the 7 day regimen and 79 CL patients received the 3 day regimen. Primary objective was the proportion of patients clinically cured at 6 weeks follow-up. Secondary objectives were clinical cure at 12 weeks follow-up; parasitological cure at 6 and 12 weeks; adverse and drug related toxicity events recorded one week after the end of treatment and health related quality of life. The non-inferiority margin was set at 15%, 1 sided test, α = 0.1.
At 6 weeks follow-up 31 (39%) patients in the 3 day regimen and 41 (49%) patients in the 7 day regimen were clinically cured. Intention to treat (ITT) analyses showed that the difference in proportion clinically cured was -9.6% (90% Confidence Interval (CI): -22.3% to 3.2%). Per protocol (PP) analysis showed that the difference in proportion clinically cured was 0.2% (90% CI: -14.6% to 15.2%). ITT analysis showed that the difference in proportion parasitological cured at 6 weeks was -15.2% (90% CI:-28.0% to -2.5%). PP analyses showed similar results. Non-inferiority could not be concluded for all adverse and toxicological events.
We cannot conclude that the 3 day regimen is non-inferior to the 7 day regimen regarding proportion clinically and parasitological cured. Therefore there is no evidence to change the current standard practice of the 7 day regimen for the treatment of CL in Suriname.
Graphene has emerged as an electronic material that is promising for device applications and for studying two-dimensional electron gases with relativistic dispersion near two Dirac points. ...Nonetheless, deviations from Dirac-like spectroscopy have been widely reported with varying interpretations. Here we show evidence for strain-induced spatial modulations in the local conductance of single-layer graphene on SiO2 substrates from scanning tunneling microscopic (STM) studies. We find that strained graphene exhibits parabolic, U-shaped conductance vs bias voltage spectra rather than the V-shaped spectra expected for Dirac fermions, whereas V-shaped spectra are recovered in regions of relaxed graphene. Strain maps derived from the STM studies further reveal direct correlation with the local tunneling conductance. These results are attributed to a strain-induced frequency increase in the out-of-plane phonon mode that mediates the low-energy inelastic charge tunneling into graphene.
Acidification of the tumor microenvironment from abnormal metabolism along with angiogenesis to meet metabolic demands are both hallmarks of malignant brain tumors; however, the interdependency of ...tumor acidity and vascularity has not been explored. Therefore, our aim was to investigate the association between pH-sensitive amine chemical exchange saturation transfer echoplanar imaging (CEST-EPI) and relative cerebral blood volume (CBV) measurements obtained from dynamic susceptibility contrast (DSC) perfusion MRI in patients with gliomas.
In this retrospective study, 90 patients with histologically confirmed gliomas were scanned between 2015 and 2018 (median age, 50.3 years; male/female ratio = 59:31). pH-weighting was obtained using chemical exchange saturation transfer echo-planar imaging estimation of the magnetization transfer ratio asymmetry at 3 ppm, and CBV was estimated using DSC-MR imaging. The voxelwise correlation and patient-wise median value correlation between the magnetization transfer ratio asymmetry at 3 ppm and CBV within T2-hyperintense lesions and contrast-enhancing lesions were evaluated using the Pearson correlation analysis.
General colocalization of elevated perfusion and high acidity was observed in tumors, with local intratumor heterogeneity. For patient-wise analysis, median CBV and magnetization transfer ratio asymmetry at 3 ppm within T2-hyperintense lesions were significantly correlated (
= 0.3180,
= .002), but not in areas of contrast enhancement (
= .52). The positive correlation in T2-hyperintense lesions remained within high-grade gliomas (
= 0.4128,
= .001) and in
wild-type gliomas (
= 0.4300,
= .002), but not in World Health Organization II or in
mutant tumors. Both magnetization transfer ratio asymmetry at 3 ppm and the voxelwise correlation between magnetization transfer ratio asymmetry and CBV were higher in high-grade gliomas compared with low-grade gliomas in T2-hyperintense tumors (magnetization transfer ratio asymmetry,
= .02
Pearson correlation,
= .01). The same trend held when comparing
wild-type gliomas and
mutant gliomas (magnetization transfer ratio asymmetry,
= .04; Pearson correlation,
= .01).
A positive linear correlation between CBV and acidity in areas of T2-hyperintense, nonenhancing tumor, but not enhancing tumor, was observed across patients. Local heterogeneity was observed within individual tumors.
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