Drawing upon affective events theory (AET), this study seeks to investigate the effects of workplace contextual factors - such as procedural justice climate (PJC), or a lack thereof - on ...subordinates' 'perception of abusive supervision' (AS), which is largely overlooked in the domain of AS. The data (213 subordinates across 51 work groups) showed that subordinates' perception of AS and their feelings of anger, in turn, mediated the deleterious effects of PJC (or a lack thereof) on subordinates' organisational citizenship behaviours (OCBs). The study contributes to the AS literature by highlighting and investigating PJC, building on understanding around subordinates' perceptions of AS. Also, by incorporating a two-stage mediating mechanism (stage 1: AS, stage 2: anger), this study investigates the full impact of the cascading effects of AS. Theoretical and practical implications are discussed.
Hepatocellular carcinoma （HCC） is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of ...alcoholism, hepatitis B and C prevalence and obesity-related fatty liver disease, it is expected that the incidence of HCC will also increase in the foreseeable future. This article summarizes the international epidemiology, the risk factors and the pathogenesis of HCC, including the roles of viral hepatitis, toxins, such as alcohol and aflatoxin, and insulin resistance.
The rotary bacterial flagellar motor is remarkable in biochemistry for its highly synchronized operation and amplification during switching of rotation sense. The motor is part of the flagellar basal ...body, a complex multi-protein assembly. Sensory and energy transduction depends on a core of six proteins that are adapted in different species to adjust torque and produce diverse switches. Motor response to chemotactic and environmental stimuli is driven by interactions of the core with small signal proteins. The initial protein interactions are propagated across a multi-subunit cytoplasmic ring to switch torque. Torque reversal triggers structural transitions in the flagellar filament to change motile behavior. Subtle variations in the core components invert or block switch operation. The mechanics of the flagellar switch have been studied with multiple approaches, from protein dynamics to single molecule and cell biophysics. The architecture, driven by recent advances in electron cryo-microscopy, is available for several species. Computational methods have correlated structure with genetic and biochemical databases. The design principles underlying the basis of switch ultra-sensitivity and its dependence on motor torque remain elusive, but tantalizing clues have emerged. This review aims to consolidate recent knowledge into a unified platform that can inspire new research strategies.
Manganese and europium doped zinc sulphide (Mn2+/Eu3+@ZnS) quantum dots (QDs) were prepared via direct aqueous route in order to broaden tunable emission. We report a new strategy featuring enhanced ...photoluminescence through Mn2+/Eu3+@ZnS QDs leading to an intense orange-red emission and thus remarkably enhancing PL QY up to 41.35%. The X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) studies revealed the cubic crystalline structure with average crystalline sizes in the range of 1.5–2.5 nm. The Mn2+/Eu3+@ ZnS QDs was applied as an exceptional chemical sensor for Cu2+ via quenching mechanism due to competitive coordination between QDs and Cu2+ with the limit of detection (LOD) of 0.036 μM. Furthermore, the proposed approach is capable of detecting Cu2+ in water samples with satisfactory recoveries highlighting viability and prospective applications of the sensing platform. We finally demonstrate from CIE Chromaticity diagram that doped QDs show meliorated colorimetric properties which render this new class of QDs a promising prospect to be employed in white LEDs.
•Highly fluorescent Mn2+/Eu3+@ZnS QDs are synthesized by direct aqueous route.•Tunable emission and enhanced colorimetric properties are achieved which are useful for white LEDs.•The increasing doping concentration effectively enhance PLQY up to 41.35%.•Fast and reliable sensing probe are established for Cu2+ detection with LOD of 0.036 μM.•The probe was successfully applied in real samples to detect Cu2+ yielding satisfactory recoveries (96−105)%.
Elevated amount of CO levels in the atmosphere poses serious health and environmental hazards. Oxidation of CO using suitable catalysts is one of the methods to control it. By means of DFT ...calculations, single Cu atom doped in S vacancy of MoS
2
nanosheet is studied for CO oxidation catalysis. Cu atom is strongly confined at the S-defective site of the MoS
2
sheet, possessing high energy barrier for the diffusion to its neighboring sites. Adsorption energy, charge transfer and orbital hybridization of CO and O
2
molecules adsorbed Cu-doped MoS
2
sheet reveal that O
2
is relatively more strongly adsorbed than CO. High adsorption energy of O
2
(− 2.115 eV) and large charge transfer between O
2
and Cu–MoS
2
sheet (0.493e), compared to CO, make O
2
adsorption more favorable, which extenuates CO poisoning and hence helps in the efficient CO oxidation process. The complete oxidation of CO takes place in two steps:
CO
+
O
2
→
OOCO
with activation energy of 0.201 eV, succeeded by
OOCO
+
CO
→
2
CO
2
without any energy barrier. Our results show that the basal plane of MoS
2
sheet gets activated by embedding it with Cu metal, which can catalyze CO oxidation reaction effectively and without poisoning issues. The high activity, stability and low cost features can possibly encourage fabricating MoS
2
-based catalysts for CO oxidation reaction.
The coordinated exit of intracellular pathogens from host cells is a process critical to the success and spread of an infection. While phospholipases have been shown to play important roles in ...bacteria host cell egress and virulence, their role in the release of intracellular eukaryotic parasites is largely unknown. We examined a malaria parasite protein with phospholipase activity and found it to be involved in hepatocyte egress. In hepatocytes, Plasmodium parasites are surrounded by a parasitophorous vacuole membrane (PVM), which must be disrupted before parasites are released into the blood. However, on a molecular basis, little is known about how the PVM is ruptured. We show that Plasmodium berghei phospholipase, PbPL, localizes to the PVM in infected hepatocytes. We provide evidence that parasites lacking PbPL undergo completely normal liver stage development until merozoites are produced but have a defect in egress from host hepatocytes. To investigate this further, we established a live-cell imaging-based assay, which enabled us to study the temporal dynamics of PVM rupture on a quantitative basis. Using this assay we could show that PbPL-deficient parasites exhibit impaired PVM rupture, resulting in delayed parasite egress. A wild-type phenotype could be re-established by gene complementation, demonstrating the specificity of the PbPL deletion phenotype. In conclusion, we have identified for the first time a Plasmodium phospholipase that is important for PVM rupture and in turn for parasite exit from the infected hepatocyte and therefore established a key role of a parasite phospholipase in egress.
Silver nanotechnology has received tremendous attention in recent years, owing to its wide range of applications in various fields and its intrinsic therapeutic properties. In this review, an attempt ...is made to critically evaluate the chemical, physical, and biological synthesis of silver nanoparticles (AgNPs) as well as their efficacy in the field of theranostics including microbiology and parasitology. Moreover, an outlook is also provided regarding the performance of AgNPs against different biological systems such as bacteria, fungi, viruses, and parasites (leishmanial and malarial parasites) in curing certain fatal human diseases, with a special focus on cancer. The mechanism of action of AgNPs in different biological systems still remains enigmatic. Here, due to limited available literature, we only focused on AgNPs mechanism in biological systems including human (wound healing and apoptosis), bacteria, and viruses which may open new windows for future research to ensure the versatile application of AgNPs in cosmetics, electronics, and medical fields.
Epidemiology of cholangiocarcinoma Qurashi, Maria; Vithayathil, Mathew; Khan, Shahid A.
European journal of surgical oncology,
09/2023
Journal Article
Recenzirano
Odprti dostop
Cholangiocarcinoma (CCA) represents a heterogenous set of malignancies arising from the biliary tract. Classification of CCA subdivides tumours into intrahepatic (iCCA) and extrahepatic (eCCA), with ...eCCA further categorised as perihilar (pCCA) and distal (dCCA) lesions. Tumour subtypes show distinct epidemiological, genetic and clinical characteristics. Global incidence and mortality are rising, with the highest rates seen in Asian populations compared to the West. There has been a divergence in recent mortality trends observed between CCA subtypes, with rising rates of iCCA seen compared with eCCA. There are several drivers for these differing trends, including specific risk factors, misclassification of CCA subtypes and variation in diagnosis and surveillance. Risk factors for CCA can be divided into hepatobiliary, extra-hepatic and environmental, with hepatobiliary diseases conferring the largest risk. Surgery represents the only curative treatment for CCA, but can only be offered to early-stage candidates who are otherwise fit; the majority of patients are therefore treated with chemotherapy and, recently, immunotherapy. Due to late-stage presentation of disease, prognosis is poor, with 5-year survival <20%.
Wild medicinal herbs have been used as folk and traditional medicines all across the world since well before recorded history. This present study was designed to test the antimicrobial activities of ...five different solvent extracted samples (n-hexane, n-butanol, ethyl acetate, methanol, and water) of Peganum harmala using stems and seeds. Two different strains of Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), two Gram-positive bacteria (Bacillus subtilus and Staphylococcus aureus), and one fungal strain (Candida albicans) were used. The antimicrobial activities were measured using a disc diffusion assay. Two concentrations of the extracts (1 and 2mgDisc-1) were used. Ethyl acetate fraction was found more affective among the tested solvents and showed maximum activity (zone of inhibition) against S. aureus (65.53 and 81.10%), E. coli (46.22 and 61.29%) while n-butanol and water fractions gave maximum activity against S. aureus (78.86 and 70.00%) and K. pneumonia (57.00 and 61.39%) respectively. Water fraction showed maximum activity against C. albicans (60.00 and 81.88%). In the case of the stem, Ethyl acetate again showed more activity against B. subtilus (38.57 and 42.10%) and S. aureus (36.66 and 46.66%) while n-butanol showed maximum activity against K. pneumonia (24.55 and 32.44%) and E. coli (27.93 and 37.61%). Methanol was found more effective against C. albicans (25.71 and 43.80%). Seed extracted samples were found more effective compared to the stem. Ethyl acetate, butanol, and aqueous extracted samples showed good activity against the tested microbes, so these fractions are recommended for study their mechanism of actions and isolation of bioactive metabolites responsible for antimicrobial activities. The P. harmala should be evaluated for their bioactive compounds to be used in future studies. Our objective is to provide the framework for future study on the roles of P. harmala as traditional medicines.
Cells from all three domains of life on Earth utilize motile macromolecular devices that protrude from the cell surface to generate forces that allow them to swim through fluid media. Research ...carried out on archaea during the past decade or so has led to the recognition that, despite their common function, the motility devices of the three domains display fundamental differences in their properties and ancestry, reflecting a striking example of convergent evolution. Thus, the flagella of bacteria and the archaella of archaea employ rotary filaments that assemble from distinct subunits that do not share a common ancestor and generate torque using energy derived from distinct fuel sources, namely chemiosmotic ion gradients and FlaI motor-catalyzed ATP hydrolysis, respectively. The cilia of eukaryotes, however, assemble via kinesin-2-driven intraflagellar transport and utilize microtubules and ATP-hydrolyzing dynein motors to beat in a variety of waveforms via a sliding filament mechanism. Here, with reference to current structural and mechanistic information about these organelles, we briefly compare the evolutionary origins, assembly and tactic motility of archaella, flagella and cilia.
Khan and Scholey compare the evolutionary origins, assembly and motility functions of motile macromolecular devices from archaea, bacteria and eukaryotes, highlighting current structural and mechanistic information about these organelles.
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