Indium-decorated Pd nanocubes degrade nitrate anions rapidly

Indium-decorated palladium nanoparticles (In-on-PdNPs) are active for room-temperature catalytic reduction of aqueous nitrate, where the active sites are metallic In atoms on the Pd surface. The PdNPs are pseudo-spherical in shape, and it is unclear if their faceted nature plays a role in nitrate reduction. We synthesized different-sized, cube-shaped NPs with differing In coverages (sc%), and studied the resultant In-on-Pd-nanocubes (NCs) for nitrate reduction. The NCs exhibited volcano-shape activity dependence on In sc%, with peak activity around 65–75 sc%. When rate constants were normalized to undercoordinated atoms (at edge + corners), the NCs exhibited near-identical maximum activity (20×-higher than In-on-PdNPs) at ρIn/Pd edge+corner ∼0.5 (∼5 In atoms per 10 edge and corner atoms). NCs with a higher In edge + corner density (ρIn/Pd edge+corner ∼1.5) were less active but did not generate NH4+ at nitrate conversions tested up to 36 %. Edge-decorated cubes may be the structural basis of improved bimetallic catalytic denitrification of water

Evaluation of three PCR-based diagnostic assays for detecting mixed Plasmodium infection

<p>Abstract</p> <p>Background</p> <p>One of the most commonly used molecular test for malaria diagnosis is the polymerase chain reaction (PCR)-based amplification of the 18S ribosomal DNA (rDNA) gene. Published diagnostic assays based on the 18S gene include the "gold standard" nested assay, semi-nested multiplex assay, and one tube multiplex assay. To our knowledge, no one has reported whether the two multiplex methods are better at detecting mixed <it>Plasmodium </it>infections compared to the nested assay using known quantities of DNA in experimentally mixed cocktails.</p> <p>Findings</p> <p>Here we evaluated three PCR assays (nested, semi-nested multiplex, and one-tube multiplex) for the simultaneous detection of human malaria parasites using experimentally mixed cocktails of known quantities of laboratory derived DNA. All three assays detected individual species with high sensitivity and specificity when DNA was from any one single species; however, experimentally mixed DNA cocktails with all four species present were correctly identified most consistently with the nested method. The other two methods failed to consistently identify all four species correctly, especially at lower concentrations of DNA -subclinical levels of malaria (DNA equivalent to or less than 10 parasites per microliter).</p> <p>Conclusions</p> <p>The nested PCR method remains the method of choice for the detection of mixed malaria infections and especially of sub-clinical infections. Further optimization and/or new molecular gene targets may improve the success rate of detecting multiple parasite species simultaneously using traditional PCR assays.</p

Specific and rapid detection of Microsporia in stool specimens from AIDS patients by PCR

Two microsporidian species, Enterocytozoon bieneusi and Encephalitozoon intestinalis, are the cause of diarrhoea and wasting syndrome in AIDS patients. A new PCR assay is proposed for the rapid and specific detection of these parasites in stools

A comparative study on the antimicrobial resistance of Escherichia coli isolates from chickens and fish grown on integrated and traditional fish farms

Escherichia coli was isolated from fish grown in a pond that had never been exposed to antibioticsupplemented feeds (control group), and from fish on an integrated farm, fed for 6 wk with manure of chickens that received tetracycline-supplemented and chloramphenicol-supplemented feeds. E. coli was also isolated from these chickens after being fed such for 23 d. The antibiograms of the isolates were determined using the disk diffusion method. The prevalence of E. coli isolates from fish and chickens on the integrated farm that were resistant to tetracycline and chloramphenicol, to trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin and amoxicillin were significantly higher (p \u3c 0.05) than those from fish in the control farm. In addition, the diversity of resistance was also greater among E. coli from the integrated farm group, which concurs with the results of other studies that exposure to antimicrobials results in higher prevalence of resistant isolates as a consequence of positive selection. On the other hand, the prevalence of resistant E. coli from fish and chickens on the integrated farm that received and those that did not receive antibiotics in their feeds were not significantly different (p \u3e 0.05), indicating that exposure to antimicrobials was not required for the occurrence and maintenance of resistant strains. The data suggest that prevalence of antimicrobial resistant strains is a result of the dynamic interplay of environmental and host-specific factors

A comparative study on the antimicrobial resistance of Escherichia coli isolates from chickens and fish grown on integrated and traditional fish farms

Escherichia coli was isolated from fish grown in a pond that had never been exposed to antibiotic- supplemented feeds (control group), and from fish on an integrated farm, fed for 6 wk with manure of chickens that received tetracycline-supplemented and chloramphenicol-supplemented feeds. E. coli was also isolated from these chickens after being fed such for 23 d. The antibiograms of the isolates were determined using the disk diffusion method. The prevalence of E. coli isolates from fish and chickens on the integrated farm that were resistant to tetracycline and chloramphenicol, to trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin and amoxicillin were significantly higher (p0.05), indicating that exposure to antimicrobials was not required for the occurrence and maintenance of resistant strains. The data suggest that prevalence of antimicrobial resistant strains is a result of the dynamic interplay of environmental and host-specific factors

Impact of antimicrobial use on the antibiotic resistance of Escherichia coli isolates from chickens and fish grown on integrated fish farms

Escherichia coli was isolated from fish grown in a pond that had never been exposed to antibiotic-supplemented feeds (Control Group), and from fish on an integrated farm, fed for six weeks with manure of chickens that received tetracycline and chloramphenicol-supplemented feeds. E. coli was also isolated from these chickens after being fed such for 23 days. The antibiograms of the isolates were determined using the disk diffusion method. The prevalence of E. coli isolates from fish and chickens on the integrated farm that were resistant to tetracycline and chloramphenicol, to trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin, and amoxicillin were significantly higher (p0.05), showing that exposure to antimicrobials was not required for the occurrence and maintenance of resistant strains. Data of the study suggest that prevalence of antimicrobial resistant strains is a result of the dynamic interplay of environmental and host-specific factors

Development of a cervical cancer prevention text-messaging program for women living with HIV

Cervical cancer screening and human papillomavirus (HPV) vaccination are critical for those immunocompromised due to human immunodeficiency virus (HIV). Health education programs, including text messaging, can effectively improve knowledge of cervical cancer and recommended screening. This paper describes the data-driven development of a 4-week text-messaging intervention to improve HPV and cervical cancer knowledge among women living with HIV (WLH). This study reports data from surveys (n = 81; January 2020 to September 2021) and focus group discussions (FGDs, n = 39; April-June 2020) conducted among WLH in the DC area. While most WLH revealed that their usual sources of health information were through in-person group sessions, they pointed out that these were impractical options due to the coronavirus 2019 pandemic. They noted that a text-messaging intervention was feasible and acceptable. FGD participants\u27 responses structured around the Protection Motivation Theory constructs informed the text-messaging library, covering topics such as (I) understanding of cervical cancer and HPV, (II) cervical cancer prevention and (III) HPV self-sampling. The utilization of low-cost and easily accessible health education interventions, such as mobile-based text messaging, can effectively increase knowledge and awareness of cervical cancer in populations that have been historically difficult to access and during times when health services are disrupted such as during a global pandemic or public health emergency