Acute cholangitis: a state-of-the-art review

Acute cholangitis is a potentially life-threatening bacterial infection of the intra and/or extrahepatic bile ducts. It remains the second and third cause of community-acquired and hospital-acquired bacteremia, respectively, and is associated with mortality rates of up to 15%, despite advances in broad-spectrum antimicrobial therapy and improved access to emergency biliary tract decompression procedures. Even though not much has changed in recent years in terms of diagnosis or treatment, new data have emerged regarding multidrug-resistant bacteria that serve as etiologic agents of cholangitis. Moreover, different approaches in antibiotic regimes depending on severity grading and bile sample cultures as well as novel minimally invasive endoscopic procedures that can help when consecrated treatments such as endoscopic retrograde cholangiopancreatography (ERCP) fail, cannot be performed, or are unavailable have been proposed. This state-of-the-art review aims to offer a complete and updated assessment of the epidemiology, novel diagnostic and therapeutic methods, complications, and prognostic variables of acute cholangitis. The authors will review the prognostic implications of unusual complications, the relevance of regular bile samples and antibiograms, and their new role in guiding antibiotic therapy and limiting antibiotic resistance to present an organized and comprehensive approach to the care of acute cholangitis

How Effective Are Sub-Bandgap States in AgInS₂ Quantum Dots for Electron Transfer?

Ternary I–III–VI2 semiconductors, such as CuInS2 and AgInS2 (compliant with RoHS, restriction of hazardous substances), are useful as light-harvesting materials. However, the presence of sub-bandgap states (donor–acceptor pair or DAP) introduces complexity during their activation through photoexcitation. When photoirradiated, the photogenerated charge carriers in AgInS2 quantum dots undergo rapid relaxation to populate intrinsic DAP states while competing with charge carrier recombination. Interestingly, these defect-related DAP states can be activated through sub-bandgap excitation and, thus, extend the absorption range to the near-infrared region. We have now employed time-resolved absorption and emission techniques to glean mechanistic insights into the photophysical properties of intragap states of AgInS2 quantum dots (QDs) and their participation in interfacial electron transfer. When the AgInS2 QDs are excited with above bandgap excitation (400 nm), we observe a prompt formation (<1 ps) of the bleach at wavelengths closer to the bandgap, indicating the formation of a charge-separated pair. This transient bleach shifts to lower energies with time (∼5 ps), indicating population of sub-bandgap states via relaxation of electrons and holes from the conduction and valence bands, respectively. These sub-bandgap states which can also be populated via direct excitation using low energy (λ Eg) excitation exhibit prompt bleach (<1 ps) in contrast to bandgap excitation. The excited DAP states are long-lived (∼1 μs) and can participate in the electron transfer process. We have elucidated the electron transfer dynamics from these midgap states of AgInS2 by employing ethyl viologen (EV2+) as a probe molecule. The role of surface-anchored viologen as an electron shuttle was further exploited by using free-floating benzoquinone (BQ) as a secondary electron acceptor. The sub-bandgap response of AgInS2 to promote electron transfer paves the way to extend the photoresponse of ternary I–III–VI2 semiconductor-based photocatalytic systems

Photocatalytic Membrane for Hydrogen Evolution: Directed Electron and Hole Transfer across Pt–AgInS₂–Nafion

A photocatalytically active membrane, designed by embedding AgInS2 semiconductor nanoparticles and a Pt cocatalyst, facilitates a “vectorial” flow of photogenerated electrons and holes in opposite directions. The fabricated Pt–AgInS2–Nafion membrane, when inserted in an H-cell containing 50% ethanol (AgInS2 side) and water (pH = 4, Pt side), produced H2 under visible light irradiation. Photogenerated electrons reduced H+ at the Pt surface to produce H2, while oxidation of ethanol with holes at AgInS2 also produced H2. Back electron transfer at the Pt surface and surface defects within AgInS2 were responsible for the lower H2 yield in the reduction compartment. Remediation of the AgInS2 film with mercaptopropionic acid increased the yield 5–10 times by overcoming the loss of charge carriers at the defect sites. The feasibility of carrying out selective reduction and oxidation processes by directing the flow of charge carriers highlights the usefulness of photocatalytic membranes in solar fuel generation

Anatomical variations of the pyramidalis muscle: a systematic review and meta-analysis

Purpose: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the pyramidalis muscle (PM). Materials and methods: A thorough systematic search of the literature through August 31st 2020 was conducted on major electronic databases PubMed, Scopus and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using MetaFor package in R and MetaXL. A random-effects model was applied. The primary outcome of interest was the prevalence of PM. The secondary outcomes were the dimensions (length and width) of the PM. Results: A total of 11 studies (n = 787 patients; 1548 sides) were included in the meta-analysis. The multinomial pooled prevalence estimate (PPE) for a bilateral absence of the PM was 11.3% (95% CI [7.2%, 16.2%], 82.3% (95% CI [76.2%, 87.6%]) for a bilateral presence, and 6.3% (95% CI [3.3%, 10.2%]) for a unilateral presence. Of four studies (n = 37 patients) that reported the side of a unilateral presence, the PPE of a unilateral right-side presence was 42.2% (95% CI [23.0%, 62.3%]) compared to 57.8% for a unilateral left-side presence (95% CI [37.7%, 77.0%]). The mean length of the PM displayed high levels of heterogeneity, ranging from 3.12 to 12.50&nbsp;cm. Conclusion: The pyramidalis muscle is a rather constant anatomical structure being present in approximately 90% of individuals

The status of flora and fauna in the Nzoia River drainage basin in western Kenya

The species richness of flora and fauna in the Nzoia River drainage basin is documented through a study of museum specimens,&nbsp; catalogues and databases. The catchment area and basin covers 2.2% (12900/580367 km2) of Kenya’s total land area with an altitudinal range of 1140 to 4300 m and varied ecosystem and land uses. We recorded approximately 9.3% (3239/34677) of Kenya’s current known species of vascular plants, invertebrates (insects and spiders), fish, amphibians, reptiles, birds and mammals. Bird species made up the highest proportion 58.3% (650/1114) of the national total followed by amphibians 37.3% (41/110), reptiles 45.0% (86/191), mammals 31.3% (122/390), vascular plants 17.9% (1251/7000), fish 6.7% (58/872) (32.2% (58/180) for freshwater fish only) and invertebrates (insects and spiders) 4.1% (1031/25000). Ninety-five species recorded in this area are endemic to Kenya and 42 globally threatened. The species recorded contribute to several ecosystem services including pest control, pollination, bio-indicators, medicine and cosmetics, building materials, ecotourism, research and education. Data available differed substantially across counties and taxon groups with gaps apparent in five counties (Bungoma, Busia, Elgeyo Marakwet, Siaya and Usain Gishu) and four taxa plants, invertebrates, fungi and bacteria where a dearth of information exists. To fill these gaps we recommend prioritisng future survey effort on taxa and counties with fewer than 10% of the total numbers of records