Microbiome-scale analysis of aerosol facemask contamination during nebulization therapy in hospital.

BACKGROUND: Microbial contamination of aerosol facemasks could be a source of nosocomial infections during nebulization therapy in hospital, prompting efforts to identify these contaminants. Identification of micro-organisms in medical devices has traditionally relied on culture-dependent methods, which are incapable of detecting the majority of these microbial contaminants. This challenge could be overcome with culture-independent sequencing-based techniques that are suited for the profiling of complex microbiomes. AIM: To characterize the microbial contaminants in aerosol facemasks used for nebulization therapy, and identify factors influencing the composition of these microbial contaminants with the acquisition and analysis of comprehensive microbiome-scale profiles using culture-independent high-throughput sequencing. METHODS: Used aerosol facemasks collected from hospitalized patients were analysed with culture-independent 16S rRNA gene-based amplicon sequencing to acquire microbiome-scale comprehensive profiles of the microbial contaminants. Microbiome-based analysis was performed to identify potential sources of microbial contamination in facemasks. FINDINGS: Culture-independent high-throughput sequencing was demonstrated for the capacity to acquire microbiome-scale profiles of microbial contaminants on aerosol facemasks. Microbial source identification enabled by the microbiome-scale profiles linked microbial contamination on aerosol facemasks to the human skin and oral microbiota. Antibiotic treatment with levofloxacin was found to reduce contamination of the facemasks by oral microbiota. CONCLUSION: Sequencing-based microbiome-scale analysis is capable of providing comprehensive characterization of microbial contamination in aerosol facemasks. Insight gained from microbiome-scale analysis facilitates the development of effective strategies for the prevention and mitigation of the risk of nosocomial infections arising from exposure to microbial contamination of aerosol facemasks, such as targeted elimination of potential sources of contamination.

The Effects of Terrain Properties Upon the Small Crater Population Distribution at Giordano Bruno: Implications for Lunar Chronology.

The distribution of impact craters on the ejecta of Giordano Bruno, a recent (<10 Ma) 22-km diameter crater within the lunar highlands, exhibits substantial variations. We surveyed craters D ≥ 10 m across a 1,323 km2 area of Giordano Bruno's ejecta and compared the distribution of craters with variations in thermophysical properties derived from the Lunar Reconnaissance Orbiter Diviner instrument. We used Diviner-derived rock abundance and nighttime regolith temperatures along with thermal model-predicted surface temperatures for a diversity of terrains to identify and isolate areas of the ejecta based on thermophysical properties such as bulk density and thermal conductivity. We found that thermophysical properties of the ejecta vary considerably both laterally and vertically, and consistently differ from typical regolith, indicating the presence of higher thermal inertia materials. Crater-size frequencies are significantly lower in areas with terrain properties exhibiting higher: rock abundance, nighttime temperatures, and/or modeled thermal inertia. This discrepancy in crater distribution increases for craters smaller than ∼25 m. These thermophysical variations indicate changes in the mechanical properties of the target materials. We suggest that these variations-specifically, terrain-dependent crater scaling variations and impactor-scale heterogeneities in material properties such as the presence or absence of large boulders-may influence crater diameters or inhibit crater production altogether in Giordano Bruno's ejecta; furthermore, these factors are size-dependent.

Silicate Volcanism on Europa's Seafloor and Implications for Habitability.

Habitable ocean environments on Europa require an influx of reactants to maintain chemical disequilibrium. One possible source of reactants is seafloor volcanism. Modeling has shown that dissipation of tidal energy in Europa's asthenosphere can generate melt, but melt formation cannot be equated with volcanism. Melt must also be transported through Europa's cold lithosphere to erupt at the seafloor. Here, we use two models of dike propagation to show that dikes can only traverse the lithosphere if either the fracture toughness of the lithosphere or the flux into the dike is large (>500 MPa m1/2 or ∼1 m2 s-1, respectively). We conclude that cyclic volcanic episodes might provide reactants to Europa's ocean if magma accumulates at the base of the lithosphere for several thousand years. However, if dikes form too frequently, or are too numerous, the magma flux into each will be insufficient, and volcanism cannot support a habitable ocean environment.

Microbiome Profiles of Nebulizers in Hospital Use.

Background: Nebulizers are used to provide treatment to respiratory patients. Concerns over nosocomial infection risks from contaminated nebulizers raise the critical need to identify all microbial populations in nebulizers used by patients. However, conventional culture-dependent techniques are inadequate with the ability to identify specific microbial populations only. Therefore, the aims of this study were to acquire complete profiles of microbiomes in nebulizers used by in-patients with culture-independent high-throughput sequencing and identify sources of microbial contaminants for the development of effective practices to reduce microbial contamination in nebulizer devices. Methods: This study was conducted at the University of Tennessee Medical Center in Knoxville, TN. Nebulizers were collected between May 2018 and October 2018 from inpatients admitted to the floors for pneumonia or chronic obstructive pulmonary disease exacerbations. Nebulizers were sampled for 16S rRNA gene-based amplicon sequencing to profile nebulizer microbiomes and perform phylogenetic analysis. A Bayesian community-wide culture-independent microbial source tracking technique was used to quantify the contribution of human-associated microbiota as potential sources of nebulizer contamination. Results: Culture-independent sequencing detected diverse microbial populations in nebulizers, represented by 18 abundant genera. Stenotrophomonas was identified as the most abundant genus, accounting for 12.4% of the nebulizer microbiome, followed by Rhizobium, Staphylococcus, Streptococcus, and Ralstonia. Phylogenetic analysis revealed the presence of multiple phylotypes with close relationship to potential pathogens. Contributing up to 15% to nebulizer microbiomes, human-associated microbiota was not identified as the primary sources of nebulizer contamination. Conclusion: Culture-independent sequencing was demonstrated to be capable of acquiring comprehensive profiles of microbiomes in nebulizers used by in-patients. Phylogenetic analysis identified differences in pathogenicity between closely related phylotypes. Microbiome profile-enabled community-wide culture-independent microbial source tracking suggested greater importance of environmental sources than human sources as contributors to nebulizer microbiomes, providing important insight for the development of effective strategies for the monitoring and control of nebulizer devices to mitigate infection risks in the hospital.

Microbiome-based source identification of microbial contamination in nebulizers used by inpatients.

Nebulizers are essential for the delivery of aerosolized medication for respiratory patients in hospital. Microbial contamination of nebulizers increases the risk of healthcare-associated infections, presenting the critical need to identify sources of contamination in order to develop effective infection prevention and control practices in hospitals. Using an innovative microbiome-based cultivation-independent microbial source identification technique, the hospital indoor environment was identified as a significant source contributing to microbial contaminants in nebulizers, providing important information to develop strategies for targeted decontamination and enhance the effectiveness of infection prevention and control practices.

Asteroid (101955) Bennu's weak boulders and thermally anomalous equator.

Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high-thermal inertia band at Bennu's equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.

Does Body Mass Index Influence the Physiological and Perceptual Demands Associated with Defensive Tactics Training in State Patrol Officers?

The purpose of this investigation was to determine the physiological and perceptual demands associated with defensive tactics (DEFTAC) training among state patrol officers of different BMI (body mass index) categories. Twenty-four male state patrol officers (n = 24, age 36.00 + 7.86 yrs) voluntarily agreed to participate in data collection during a DEFTAC gauntlet. Anthropometric information (height (HT) 182.19 + 7.43 cm and weight (WT) 96.31 + 17.45 kg), body mass index (BMI), peak and average heart rates, duty weight, BLa, and RPE, were recorded. Officers were then divided into two-groups (Healthy BMI (BMI ≤ 25), n = 12, Overweight (BMI ≥ 25), n = 12). Analyses of covariance (ANCOVAs) were conducted to determine the effect of BMI on the outcome variables. Furthermore, a Pearson's product-moment correlation coefficient was also conducted to determine if significant relationships between RPE, BLa, and HR existed between groups. Significant mean score differences between healthy and overweight officers were found in measures of age [t(22) 4.12, p< 0.01, R2 = .44], and weight of duty gear [t(21) 3.96, p<0.01, R2 = .33]. When used as a covariate, age also predicted average HR% [ F(1, 21) = 6.19, p < .05, partial η2 = .24]. Significant relationships were found in the healthy group between RPE and DEFTAC time, DEFTAC time and score, as well as score and post BLa. Significant relationships for the overweight group between peak (HR) percentage and post BLa, peak (HR) percentage and RPE, DEFTAC time and duty weight, and between weight and DEFTAC time. The results of this study suggest that overweight officers may have lower DEFTAC scores when compared to their healthy counterparts. Based on the results, it seems reasonable to compare physiological variables from this population to those from combative sports as well as for officers to achieve and maintain a healthy BMI value in order to improve individual DEFTAC performance.

Imidazolium-based zwitterionic surfactants: characterization of normal and reverse micelles and stabilization of nanoparticles.

This paper presents the physicochemical properties of micellar aggregates formed from a series of zwitterionic surfactants of the type 3-(1-alkyl-3-imidazolio)propane-sulfonate (ImS3-n), with n = 10, 12, 14, and 16. The ImS3-n dipolar ionic surfactants represent a versatile class of dipolar ionic compounds, which form normal and reverse micelles. Furthermore, they are able to stabilize nanoparticles in water and in organic media. Aqueous solubility is too low at room temperature to allow characterization of micellar aggregates but increases with addition of salts, allowing determination of aggregation number and cmc. As expected, these parameters depend on the length of the alkyl chain, and cmc values follow Klevens equation. In the presence of NaClO4, all ImS3-n micelles become anionoid by incorporating ClO4(-) on the micellar interface. A special feature of these surfactants is the ability to form reverse micelles and solubilize copious amounts of saline solutions in chloroform. (1)H NMR and infrared spectroscopic evidence showed that the maximum water to surfactant molar ratio w0 achievable depends on the concentration and type of salt dissolved. Reverse micelles of the ImS3-n surfactants can be used to stabilize metallic nanoparticles, whose size may be tuned by the amount of water dissolved.

Simultaneous nondestructive analysis of palladium, rhodium, platinum, and gold nanoparticles using energy dispersive X-ray fluorescence.

A selective method is proposed for the determination of palladium, gold, and sulfur in catalytic systems, by direct liquid analysis using energy dispersive X-ray fluorescence (EDXRF), under an atmosphere of helium or air. This method allows a nondestructive analysis of palladium, rhodium, platinum, and gold nanoparticulate catalysts stabilized by imidazolium propane sulfonate based zwitterionic surfactants, allowing the samples to be reused for catalytic studies. The signals from palladium, rhodium, platinum, and gold samples in the presence of imidazolium propane sulfonate-based zwitterionic surfactants obtained using EDXRF before (Pd(2+), Rh(2+), Pt(2+), and Au(3+)) and after (Pd(0), Rh(0), Pt(0), and Au(0)) formation of nanoparticles are essentially identical. The results show that the EDXRF method is nondestructive and allows detection and quantification of the main components of platinum, gold, rhodium, and palladium NPs, including the surfactant concentration, with detection and quantification limits in the range of 0.4-3 mg L(-1). The matrices used in such samples present no problems, even allowing the detection and quantification of interfering elements.

Comparison of recommendations for radiotherapy from two contemporaneous thoracic multidisciplinary meeting formats: co-located and video conference.

BACKGROUND: Thoracic multidisciplinary meetings (TMDM) are a key component of lung cancer patient management. The optimal design, organisation and function of TMDM are uncertain, and different models may serve different purposes. In the Auckland/Northland region, there are two contemporaneous weekly TMDM using different formats; one is a co-located TMDM (C-TMDM), and the other is a video conference TMDM (V-TMDM) connecting different locations. AIMS: To determine whether the rates of referral for radiotherapy (RT) and concordance between recommendations for RT and actual treatment received differed between the two TMDM formats. METHOD: A retrospective review of demographical and clinical data for cases referred for RT from both TMDM between January-June 2009 and the actual RT delivered. RESULTS: Seventy-nine and 31 lung cancers were referred for RT from the co-located TMDM and the video conference TMDM respectively. While there were significant differences in demographics related to areas of domicile, there were no significant differences between the TMDM in (i) the proportion of cases referred for RT that received RT, (ii) the intent of treatment recommended by the TMDM and the intent of RT delivered, or (iii) transit times to commencement of RT between cases referred from the different TMDM. CONCLUSION: The similar results from the different formats of TMDM indicate that cases discussed with the use of e-health technologies are not disadvantaged with respect to recommended therapy nor in the appropriateness of decisions of the TMDM. Use of such technology may reduce the existing disparities in health outcomes between urban and rural patients.

Imidazolium-based zwitterionic surfactant: a new amphiphilic Pd nanoparticle stabilizing agent.

Palladium nanoparticles (NPs) with an average size of 3.4 nm were prepared in water using imidazolium-based surfactant 3-(1-dodecyl-3-imidazolio)propanesulfonate (ImS3-12) as a stabilizer. The Pd NPs are highly dispersible in water and chloroform and were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, powder X-ray diffraction, and dynamic light scattering. The results indicate that in water the NP surface is covered with a double layer of ImS3-12 molecules. The NPs were effective in the aqueous biphasic hydrogenation of cyclohexene, with easy recycling and no loss of catalytic activity after four successive runs.

Impact of sleep, screen time, depression and stress on weight change in the intensive weight loss phase of the LIFE study.

BACKGROUND: The LIFE study is a two-phase randomized clinical trial comparing two approaches to maintaining weight loss following guided weight loss. Phase I provided a nonrandomized intensive 6-month behavioral weight loss intervention to 472 obese (body mass index 30-50) adult participants. Phase II is the randomized weight loss maintenance portion of the study. This paper focuses on Phase I measures of sleep, screen time, depression and stress. METHODS: The Phase I intervention consisted of 22 group sessions led over 26 weeks by behavioral counselors. Recommendations included reducing dietary intake by 500 calories per day, adopting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and increasing physical exercise to at least 180 min per week. Measures reported here are sleep time, insomnia, screen time, depression and stress at entry and post-weight loss intervention follow-up. RESULTS: The mean weight loss for all participants over the intensive Phase I weight loss intervention was 6.3 kg (s.d. 7.1). Sixty percent (N=285) of participants lost at least 4.5 kg (10 lbs) and were randomized into Phase II. Participants (N=472) attended a mean of 73.1% (s.d. 26.7) of sessions, completed 5.1 (s.d. 1.9) daily food records/week, and reported 195.1 min (s.d. 123.1) of exercise per week. Using logistic regression, sleep time (quadratic trend, P=0.030) and lower stress (P=0.024) at entry predicted success in the weight loss program, and lower stress predicted greater weight loss during Phase I (P=0.021). In addition, weight loss was significantly correlated with declines in stress (P=0.048) and depression (P=0.035). CONCLUSION: Results suggest that clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention.

Synthesis of a new zwitterionic surfactant containing an imidazolium ring. Evaluating the chameleon-like behavior of zwitterionic micelles.

Synthesis of a new zwitterionic surfactant containing the imidazolium ring 3-(1-tetradecyl-3-imidazolio)propanesulfonate (ImS3-14) is described. The solubility of ImS3-14 is very low but increases on addition of a salt which helps to stabilize the micellized surfactant. Fluorescence quenching and electrophoretic evidence for ImS3-14 shows that the micellar aggregation number is only slightly sensitive to added salts, as is the critical micelle concentration, but NaClO(4) markedly increases zeta potentials of ImS3-14 in a similar way as in N-tetradecyl-N,N-dimethylammonio-1-propanesulfonate (SB3-14) micelles. The rate of specific hydrogen ion catalyzed hydrolysis of 2-(p-heptoxyphenyl)-1,3-dioxolane and equilibrium protonation of 1-hydroxy-2-naphthoate ion in zwitterionic micelles of ImS3-14 and SB3-14 are increased markedly by NaClO(4) which induces anionoid character and uptake of H(3)O(+), but NaCl is much less effective in this respect. Comparison of ImS3-14 with SB3-14 is based on experimental evidence, and computational calculations indicate similarities and differences in structures of both compounds.

Mauriac syndrome--a modern reality.

We report two cases of adolescent females with poorly controlled diabetes mellitus who were found to have gross hepatomegaly on annual review. With the additional findings of short stature (in one case), delayed puberty and a Cushingoid habitus they were diagnosed with Mauriac syndrome. Within our diabetes service we have incorporated regular abdominal examinations for all children and young people with long standing, poorly controlled diabetes (HbA1c persistently >9.5%). A brief review of the literature is included.

Growth patterns in the growth-retarded premature infant.

Approximately 10% of all infants are born prematurely. A large proportion of these infants show evidence of postnatal growth impairment irrespective of whether birth weight was appropriate or small for gestational age. The timing and magnitude of catch-up growth is very variable, with the most immature infants showing markedly delayed catch up which is often incomplete. Long-term studies suggest that final stature may be affected significantly. Growth impairment in itself is of concern and there are suggestions that this group of infants should be eligible for growth hormone treatment. However, in addition, there is increasing evidence to suggest that there should be additional concerns in this group of infants, as abnormal early growth may influence disease susceptibility in adult life. This review assesses the patterns of postnatal growth and the possible later implications of early aberrant growth patterns in later life.

A randomised study of the effect of two doses of biosynthetic human growth hormone on final height of children with familial short stature.

BACKGROUND/AIMS: The effects of biosynthetic human growth hormone (r-hGH) in children with familial short stature (FSS) are varied. We determined whether responsivity to r-hGH in FSS is dose-dependent. METHOD: Randomised trial of two doses (20 or 40 IU/m(2) body surface area/week by daily subcutaneous injection) of r-hGH in 29 (24 male, 5 female) FSS children with assessment at adult height. RESULTS: Age range at presentation was 5.1-10.5 years, height less than 1.5 standard deviation scores (SDS) below the mean, height velocity SDS greater than -1.5 and peak growth hormone response to provocative testing over 13.5 mU/l. Adult height data (SDS) at 16.5 +/- 2.1 years for the low-dose group and 16.1 +/- 1.1 years for the high-dose group (p = 0.62) were similar [low dose -1.06 (SD 0.75), high dose -1.02 (SD 0.83); p = 0.88]. The incremental effect of both doses on stature was minimal [low-dose difference in height actual-predicted 0.79 (SD 0.94), high dose 1.27 (SD 0.88); p = 0.12]. CONCLUSION: Using this r-hGH dosing schedule there were little short- or long-term effects on height in children with FSS.