On Chemical Bonding in ht-Ga3Rh and Its Effect on Structural Organization and Thermoelectric Behavior.

In the course of systematic studies of intermetallic compounds Ga3TM (TM─transition metal), the compound Ga3Rh is synthesized by direct reaction of the elements at 700 °C. The material obtained is characterized as a high-temperature modification of Ga3Rh. Powder and single-crystal X-ray diffraction analyses reveal tetragonal symmetry (space group P42/mnm, No. 146) with a = 6.4808(2) Å and c = 6.5267(2) Å. Large values and strong anisotropy of the atomic displacement parameters of Ga atoms indicate essential disorder in the crystal structure. A split-position technique is applied to describe the real crystal structure of ht-Ga3Rh. Bonding analysis in ht-Ga3Rh performed on ordered models with the space groups P1̅, P42nm, and P42212 shows, besides the omnipresent heteroatomic Ga-Rh bonds in the rhombic prisms ∞3[Ga8/2Rh2], the formation of homoatomic Ga-Ga bonds bridging the Rh-Rh contacts and the absence of significant Rh-Rh bonding. These features are essential reasons for the experimentally observed disorder in the lattice. In agreement with the calculated electronic density of states, ht-Ga3Rh shows temperature-dependent electrical resistivity of a "bad metal". The very low lattice thermal conductivity of less than 0.5 W m-1 K-1 at 300 K, being lower than those for most other Ga3TM compounds, correlates with the enhanced bonding complexity.

Chlorhexidine and Mupirocin for Clearance of Methicillin-Resistant Staphylococcus aureus Colonization After Hospital Discharge: A Secondary Analysis of the Changing Lives by Eradicating Antibiotic Resistance Trial.

BACKGROUND: The CLEAR Trial demonstrated that a multisite body decolonization regimen reduced post-discharge infection and hospitalization in methicillin-resistant Staphylococcus aureus (MRSA) carriers. Here, we describe decolonization efficacy. METHODS: We performed a large, multicenter, randomized clinical trial of MRSA decolonization among adult patients after hospital discharge with MRSA infection or colonization. Participants were randomized 1:1 to either MRSA prevention education or education plus decolonization with topical chlorhexidine, oral chlorhexidine, and nasal mupirocin. Participants were swabbed in the nares, throat, axilla/groin, and wound (if applicable) at baseline and 1, 3, 6, and 9 months after randomization. The primary outcomes of this study are follow-up colonization differences between groups. RESULTS: Among 2121 participants, 1058 were randomized to decolonization. By 1 month, MRSA colonization was lower in the decolonization group compared with the education-only group (odds ration [OR] = 0.44; 95% confidence interval [CI], .36-.54; P ≤ .001). A similar magnitude of reduction was seen in the nares (OR = 0.34; 95% CI, .27-.42; P < .001), throat (OR = 0.55; 95% CI, .42-.73; P < .001), and axilla/groin (OR = 0.57; 95% CI, .43-.75; P < .001). These differences persisted through month 9 except at the wound site, which had a relatively small sample size. Higher regimen adherence was associated with lower MRSA colonization (P ≤ .01). CONCLUSIONS: In a randomized, clinical trial, a repeated post-discharge decolonization regimen for MRSA carriers reduced MRSA colonization overall and at multiple body sites. Higher treatment adherence was associated with greater reductions in MRSA colonization.

Decolonization to Reduce Postdischarge Infection Risk among MRSA Carriers.

BACKGROUND: Hospitalized patients who are colonized with methicillin-resistant Staphylococcus aureus (MRSA) are at high risk for infection after discharge. METHODS: We conducted a multicenter, randomized, controlled trial of postdischarge hygiene education, as compared with education plus decolonization, in patients colonized with MRSA (carriers). Decolonization involved chlorhexidine mouthwash, baths or showers with chlorhexidine, and nasal mupirocin for 5 days twice per month for 6 months. Participants were followed for 1 year. The primary outcome was MRSA infection as defined according to Centers for Disease Control and Prevention (CDC) criteria. Secondary outcomes included MRSA infection determined on the basis of clinical judgment, infection from any cause, and infection-related hospitalization. All analyses were performed with the use of proportional-hazards models in the per-protocol population (all participants who underwent randomization, met the inclusion criteria, and survived beyond the recruitment hospitalization) and as-treated population (participants stratified according to adherence). RESULTS: In the per-protocol population, MRSA infection occurred in 98 of 1063 participants (9.2%) in the education group and in 67 of 1058 (6.3%) in the decolonization group; 84.8% of the MRSA infections led to hospitalization. Infection from any cause occurred in 23.7% of the participants in the education group and 19.6% of those in the decolonization group; 85.8% of the infections led to hospitalization. The hazard of MRSA infection was significantly lower in the decolonization group than in the education group (hazard ratio, 0.70; 95% confidence interval [CI], 0.52 to 0.96; P=0.03; number needed to treat to prevent one infection, 30; 95% CI, 18 to 230); this lower hazard led to a lower risk of hospitalization due to MRSA infection (hazard ratio, 0.71; 95% CI, 0.51 to 0.99). The decolonization group had lower likelihoods of clinically judged infection from any cause (hazard ratio, 0.83; 95% CI, 0.70 to 0.99) and infection-related hospitalization (hazard ratio, 0.76; 95% CI, 0.62 to 0.93); treatment effects for secondary outcomes should be interpreted with caution owing to a lack of prespecified adjustment for multiple comparisons. In as-treated analyses, participants in the decolonization group who adhered fully to the regimen had 44% fewer MRSA infections than the education group (hazard ratio, 0.56; 95% CI, 0.36 to 0.86) and had 40% fewer infections from any cause (hazard ratio, 0.60; 95% CI, 0.46 to 0.78). Side effects (all mild) occurred in 4.2% of the participants. CONCLUSIONS: Postdischarge MRSA decolonization with chlorhexidine and mupirocin led to a 30% lower risk of MRSA infection than education alone. (Funded by the AHRQ Healthcare-Associated Infections Program and others; ClinicalTrials.gov number, NCT01209234 .).

Lesbian, Gay, Bisexual, Transgender, and Queer (LGBTQ+) Communities and the Coronavirus Disease 2019 Pandemic: A Call to Break the Cycle of Structural Barriers.

The coronavirus disease 2019 (COVID-19) pandemic has disproportionately impacted lesbian, gay, bisexual, transgender, and queer (LGBTQ+) communities. Many disparities mirror those of the human immunodeficiency virus (HIV)/AIDS epidemic. These health inequities have repeated throughout history due to the structural oppression of LGBTQ+ people. We aim to demonstrate that the familiar patterns of LGBTQ+ health disparities reflect a perpetuating, deeply rooted cycle of injustice imposed on LGBTQ+ people. Here, we contextualize COVID-19 inequities through the history of the HIV/AIDS crisis, describe manifestations of LGBTQ+ structural oppression exacerbated by the pandemic, and provide recommendations for medical professionals and institutions seeking to reduce health inequities.

Phase Equilibria and Thermoelectric Properties in the Pb-Ga-Te System in the Vicinity of the PbGa6Te10 Phase.

PbGa6Te10 is a promising thermoelectric (TE) material due to its ultralow thermal conductivity and moderated values of the Seebeck coefficient. However, the reproducible synthesis of the PbGa6Te10-based materials for the investigation and tailoring of physical properties requires detailed knowledge of the phase diagram of the system. With this aim, a combined thermal, structural, and microstructural study of the Pb-Ga-Te ternary system near the PbGa6Te10 composition is presented here, in which polycrystalline samples with the compositions (PbTe)1-x(Ga2Te3)x (0.67 ≤ x ≤ 0.87) and PbyGa6Te10 (0.85 ≤ y ≤ 1.5) were synthesized and characterized. Differential scanning calorimetry measurements revealed that PbGa6Te10 melts incongruently at 1007 ± 2 K and has a polymorphic phase transition at 658-693 K depending on composition. Powder X-ray diffraction of annealed samples confirmed that below 658 K, the trigonal modification of PbGa6Te10 exists (space groups P3121 or P3221) and above 693 K, the rhombohedral one (space group R32). A homogeneity range was found for PbyGa6Te10, y = 0.9-1.1, based on refined lattice parameters of PbyGa6Te10 in samples annealed at 873 K. The revised version of the PbTe-Ga2Te3 phase diagram in the vicinity of the PbGa6Te10 phase is proposed. Based on the new results of the phase equilibria, the TE properties of the PbyGa6Te10 samples were studied in detail. The deviation from the stoichiometric composition leads to a tuning of the charge transport in PbyGa6Te10, and as a result, the Seebeck coefficient and electrical conductivity were significantly modified over the homogeneity range. The Pb-deficient Pb0.9Ga6Te10 sample shows an improved power factor up to 9.5 µW m-1 K-2 and a reduced thermal conductivity as low as 0.17 W m-1 K-1 due to attuned chemical potential and additional scattering of phonons on point defects. Thus, the ZT parameter for this composition was improved up to ∼0.043 at 773 K, which is almost 4 times higher than that of the stoichiometric specimen. This work shows that the knowledge of phase equilibria and crystal chemistry plays a key role in improving the energy conversion efficiency for new functional TE materials.

COVID-19 Pandemic: Disparate Health Impact on the Hispanic/Latinx Population in the United States.

In December 2019, a novel coronavirus known as SARS-CoV-2, emerged in Wuhan, China, causing the coronavirus disease 2019 we now refer to as COVID-19. The World Health Organization declared COVID-19 a pandemic on 12 March 2020. In the United States, the COVID-19 pandemic has exposed preexisting social and health disparities among several historically vulnerable populations, with stark differences in the proportion of minority individuals diagnosed with and dying from COVID-19. In this article we will describe the emerging disproportionate impact of COVID-19 on the Hispanic/Latinx (henceforth: Hispanic or Latinx) community in the United States, discuss potential antecedents, and consider strategies to address the disparate impact of COVID-19 on this population.

Racial Disparity of Coronavirus Disease 2019 in African American Communities.

The coronavirus disease 2019 (COVID-19) pandemic has unveiled unsettling disparities in the outcome of the disease among African Americans. These disparities are not new but are rooted in structural inequities that must be addressed to adequately care for communities of color. We describe the historical context of these structural inequities, their impact on the progression of COVID-19 in the African American (black) community, and suggest a multifaceted approach to addressing these healthcare disparities. (Of note, terminology from survey data cited for this article varied from blacks, African Americans, or both; for consistency, we use African Americans throughout.).

Spectrum of Diversity in Today's Infectious Diseases Workforce: It's Much Broader and Brighter Than You Think.

The spectrum of inclusion, diversity, access, and equity among the Infectious Diseases (ID) workforce is ever-growing, ever-evolving, and continuously benefiting from the contributions made by the unique differences among our workforce which make us stronger, smarter, and better prepared to respond to whatever emerging ID challenge we will encounter next.

Prokaryotic and eukaryotic community structure affected by the presence of an acid mine drainage from an abandoned gold mine.

The acid mine drainage that originates in the abandoned gold mine in San Luis, Argentina, is released into La Carolina stream. The aim of this study was to determine the influence of this mine drainage on the physicochemical parameters of the area studied and on both prokaryotic and eukaryotic community structure. In addition, specific relationships between microbial taxonomic groups and physicochemical parameters were established. The drainage that flows into La Carolina stream acidifies the stream and increases its sulfate, Zn, Cd and Te concentrations. Microbial analysis showed that prokaryotic community structure is mainly affected by pH values. Actinobacteria and Gammaproteobacteria were abundant in samples characterized by low pH values, while Nitrospirae, Chloroflexi, Deltaproteobacteria, Thaumarchaeota and Euryarchaeota were associated with high concentrations of heavy metals. Otherwise, Alphaproteobacteria was present in samples taken in sunlit areas. Regarding eukaryotic community structure, the sunlight had the greatest impact. Inside the mine, in the absence of light, fungi and protists members were the most abundant microorganisms, while those samples taken in the presence of light displayed algae (green algae and diatoms) as the most abundant ones. After receiving the mine drainage, the stream showed a decrease in the diatom abundance and green algae predominated.

On Fe-Fe Dumbbells in the Ideal and Real Structures of FeGa3.

The intermetallic phase FeGa3 belongs to the rare examples of substances with transition metals where semiconducting behavior is found. The necessary electron count of 17 ve/fu can be formally derived from eight Fe-Ga and one Fe-Fe two-center-two-electron bond. The situation is reminiscent of the well-known Fe2(CO)9 scenario, where a direct Fe-Fe two-center-two-electron bond was shown to not be present. Fe-Fe interaction in FeGa3 and its substitution variants represents the crucial point for explanation of electronic, thermal transport, and optical properties of this material. Chemical bonding analysis in position space of FeGa3 and Fe2(CO)9 on the basis of the topology of the electron localizability indicator distribution, QTAIM atoms, two- and three-center delocalization indices, domain natural orbitals, IQA analysis, and an evaluation of the Fe-Fe dissociation energy yields a complete picture of the partially compensated Fe-Fe bond, which is nevertheless strong enough to be of decisive importance. Structural reinvestigation of differently synthesized single crystals leads to the composition Fe1+ xGa3 (0 ≤ x ≤ 0.018), where the additional Fe atoms are predicted from DFT/PBE calculations to yield a magnetic moment of about 2 µB/Fe2 atom and metallic in-gap states. Accompanying magnetization and ESR measurements are consistent with this picture.

Relationship between Adherence to Oral Antibiotics and Postdischarge Clinical Outcomes among Patients Hospitalized with Staphylococcus aureus Skin Infections.

Skin and soft tissue infections are common and frequently recur. Poor adherence to antibiotic therapy may lead to suboptimal clinical outcomes. However, adherence to oral antibiotic therapy for skin and soft tissue infections and its relationship to clinical outcomes have not been examined. We enrolled adult patients hospitalized with uncomplicated skin and soft tissue infections caused by Staphylococcus aureus who were being discharged with oral antibiotics to complete therapy. We fit the participants' pill bottles with an electronic bottle cap that recorded each pill bottle opening, administered an in-person standardized questionnaire at enrollment, 14 days, and 30 days, and reviewed the participants' medical records to determine outcomes. Our primary outcome was poor clinical response, defined as a change in antibiotic therapy, new incision-and-drainage procedure, or new skin infection within 30 days of hospital discharge. Of our 188 participants, 87 had complete data available for analysis. Among these participants, 40 (46%) had a poor clinical response at 30 days. The mean electronically measured adherence to antibiotic therapy was significantly different than the self-reported adherence (57% versus 96%; P < 0.0001). In a multivariable model, poor clinical response at 30 days was associated with patients having lower adherence, being nondiabetic, and reporting a lack of illicit drug use within the previous 12 months (P < 0.05). In conclusion, we found that patient adherence to oral antibiotic therapy for a skin and soft tissue infection after hospital discharge was low (57%) and associated with poor clinical outcome. Patients commonly overstate their medication adherence, which may make identification of patients at risk for nonadherence and poor outcomes challenging. Further studies are needed to improve postdischarge antibiotic adherence after skin and soft tissue infections.

Liquid chromatography coupled to molecular fluorescence with postcolumn UV sensitization for thimerosal and derivative compounds monitoring in environmental samples.

A HPLC coupled with molecular fluorescence (MF) spectrometry method for determination of thimerosal (THM, sodium ethylmercurythiosalicylate, C9 H9 HgNaO2 S), and derivatives is proposed. A sensitization of MF was provoked by UV irradiation of analytes in a home-made photoreactor that served as interface between the LC column and MF spectrometer. This method is applied to determination of THM, ethyl mercury, and thiosalicylic acid in samples of pharmaceutical industry effluents, and waters of La Carolina and Jáchal rivers situated in the center-west side of San Luis city and in the east of San Juan city (Middle West, Argentine) where the effluents are dumped. The LODs calculated on basis of 3σ criterion were 1.8, 5, and 0.05 µmol/L for THM, ethyl mercury, and for thiosalicylic acid, respectively.

Germanium Dumbbells in a New Superconducting Modification of BaGe3.

We report the high-pressure high-temperature synthesis (P = 15 GPa, T = 1300 K) of BaGe3(tI32) adopting a CaGe3-type crystal structure. Bonding analysis reveals layers of covalently bonded germanium dumbbells being involved in multicenter Ba-Ge interactions. Physical measurements evidence metal-type electrical conductivity and a transition to a superconducting state at 6.5 K. Chemical bonding and physical properties of the new modification are discussed in comparison to the earlier described hexagonal form BaGe3(hP8) with a columnar arrangement of Ge3 triangles.

Staphylococcus aureus bacteremia at 5 US academic medical centers, 2008-2011: significant geographic variation in community-onset infections.

BACKGROUND: The incidence of community-onset (CO) methicillin-resistant Staphylococcus aureus (MRSA) bacteremia rose from the late 1990s through the 2000s. However, hospital-onset (HO) MRSA rates have recently declined in the United States and Europe. METHODS: Data were abstracted from infection prevention databases between 1 January 2008 and 31 December 2011 at 5 US academic medical centers to determine the number of single-patient blood cultures positive for MRSA and methicillin-susceptible S. aureus (MSSA) per calendar year, stratified into CO and HO infections. RESULTS: Across the 5 centers, 4171 episodes of bacteremia were identified. Center A (Los Angeles, California) experienced a significant decline in CO-MRSA bacteremia rates (from a peak in 2009 of 0.42 to 0.18 per 1000 patient-days in 2011 [P = .005]), whereas CO-MSSA rates remained stable. Centers B (San Francisco, California), D (Chicago, Illinois), and E (Raleigh-Durham, North Carolina) experienced a stable incidence of CO-MRSA and CO-MSSA bacteremia. In contrast, at center C (New York, New York), the incidence of CO-MRSA increased >3-fold (from 0.11 to 0.34 cases per 1000 patient-days [P < .001]). At most of the sites, HO-MRSA decreased and HO-MSSA rates were stable. USA300 accounted for 52% (104/202) of genotyped MRSA isolates overall, but this varied by center, ranging from 35% to 80%. CONCLUSIONS: CO-MRSA rates and the contribution of USA300 MRSA varied dramatically across diverse geographical areas in the United States. Enhanced infection control efforts are unlikely to account for such variation in CO infection rates. Bioecological and clinical explanations for geographical differences in CO-MRSA bacteremia rates merit further study.

Blend uniformity monitoring in a continuous manufacturing mixing process for a low-dosage formulation using a stream sampler and near infrared spectroscopy.

Continuous manufacturing has the potential to offer several benefits for the production of oral solid dosage forms, including reduced costs, low-scale equipment, and the application of process analytical technology (PAT) for real-time process control. This study focuses on the implementation of a stream sampler to develop a near infrared (NIR) calibration model for blend uniformity monitoring in a continuous manufacturing mixing process. Feeding and mixing characterizations were performed for three loss-in-weight feeders and a commercial continuous mixer to prepare powder blends of 2.5-7.5 % w/w ibuprofen DC 85 W with a total throughput of 33 kg/h. The NIR spectral acquisition was performed after the mixing stage using a stream sampler for flowing powders. A continuous mixer shaft speed of 250 RPM was selected to operate the mixing process based on a variability analysis developed with in-line spectral data acquired using the stream sampler at 6 RPM. A partial least squares regression (PLS-R) model was performed and evaluated, yielding a root-mean-square error of prediction (RMSEP) of 0.39 % w/w and a bias of 0.05 % w/w. An independent experimental run conducted two days later revealed that the continuous mixing process and the NIR calibration model presented low day-to-day variation. The minimum practical error (MPE) and sill values through variographic analysis showed low variance associated with the sampling process using the stream sampler. Results demonstrated the promising capacity of the stream sampler coupled to an NIR probe to be implemented within continuous manufacturing processes for the real-time determination of API concentration.

Nectar and flower traits of different onion male sterile lines related to pollination efficiency and seed yield of F1 hybrids.

Honey bees are the main pollinators of onion crops for seed production, but owing to low attractiveness of flowers, pollination is often inadequate. Pollination problems result in low seed yields. This problem is accentuated when male sterile lines (MSL) are used to produce hybrid onion seeds. In this study, the effect of floral attributes and nectar composition on the preference of honey bees of four MSLs and one onion open pollinated cultivar were assessed. The chemical composition of nectar was described through the analysis of sugars, trace elements, volatile organic compounds, and phenol compounds. The samples studied showed qualitative and quantitative differences in the analyzed traits of flowers and nectar among the different lines. Furthermore, field observations showed a great difference on the number of bee visits and seed yield among the onion lines analyzed. For the first time, this study demonstrates that there are marked differences in the chemical composition of nectar and floral morphology between open pollinated and MSLs and also within MSLs. In addition, these differences were correlated with the number of visits and seed yield. Therefore, it would be possible to select indirectly the most promising productive MSL using simple determinations of chemical compounds or floral morphological characters.

Diuretic activity of Euphorbia serpens extracts in Wistar rats.

Euphorbia serpens has been used in central-west region of Argentina in traditional medicine as diuretic plant. The aim of this present study was to evaluate the diuretic activity of E. serpens in-vivo. We used dried aerial parts, and infusions from these were orally administered to Wistar rats. Its effect was evaluated using furosemide as a positive drug and isotonic salt solution as negative control. Their urine output was quantified at several time intervals. The volume of urine excreted and Na+ increased significantly, being similar to furosemide. Mannitol, was the main component in aqueous extracts of E. serpens, and the acetone extract showed the presence of Δ12- oleanane-type triterpenoids compounds, mainly hederagenin. No toxic effects were observed.

Bivalent copper ions presence triggers removal and homeostatic mechanisms in the metal-resistant microorganism Apiotrichum loubieri M12.

Microorganisms, especially those habiting mining environments, are of great importance for the retention of toxic metals in the environment. This work aimed to isolate a copper removing-microorganism from sediments of an Acid Mine Drainage-affected environment and to study the cellular responses trigger by metal presence. Apiotrichum loubieri M12 was able to tolerate and remove Cu(II) from liquid culture media, reaching a 30-35% removal capacity when it was exposed to 40 µg mL-1 Cu(II) after 48 h. Analysis of the biomass exposed to the metal through SEM-EDS showed copper presence on the cell surface and variations in the proportion of other biomass constituent elements. Proteomics revealed that the presence of Cu(II) induces differential expression of intracellular proteins involved in a wide variety of metabolic processes. Interestingly, a specific response to the metal was detected in cell-free supernatants, in which copper binding proteins were identified. A large number of proteins with metal ion binding sites were detected both at intra and extracellular levels. The microorganism responds not only by adjusting intracellular protein expression, but also by adjusting expression of proteins in the extracellular space.