Project description:The fight against the COVID-19 epidemic significantly raises the global demand for personal protective equipment, especially disposable face masks (DFMs). The discarded DFMs may become a potential source of microplastics (MPs), which has attracted much attention. In this work, we identified the detailed source of MPs released from DFMs with laser direct infrared spectroscopy. Polypropylene (PP) and polyurethane (PU) accounted for 24.5% and 57.1% of released MPs, respectively. The melt-blown fabric was a dominant MPs source, however, previous studies underestimated the contribution of mask rope. The captured polyethylene terephthalate (PET), polyamide (PA), polyethylene (PE), and polystyrene (PS) in airborne only shared 18.4% of released MPs. To deepen the understanding of MPs release from medical mask into the aquatic environment, we investigated the effects of environmental factors on MPs release. Based on regression analysis, the effects of temperature, incubation time, and wearing time significantly affect the release of MPs. Besides, acidity, alkalinity, sodium chloride, and humic acid also contributed to the MPs release through corroding, swelling, or repulsion of fibers. Based on the exposure of medical mask to simulated environments, the number of released MPs followed the order: seawater > simulated gut-fluid > freshwater > pure water. Considering the risk of MPs released from DFMs to the environment, we innovatively established a novel flotation removal system combined with cocoamidopropyl betaine, achieving 86% removal efficiency of MPs in water. This work shed the light on the MPs release from DFMs and proposed a removal strategy for the control of MPs pollution.
Project description:BackgroundWidespread bioinformatic resource development generates a constantly evolving and abundant landscape of workflows and software. For analysis of the microbiome, workflows typically begin with taxonomic classification of the microorganisms that are present in a given environment. Additional investigation is then required to uncover the functionality of the microbial community, in order to characterize its currently or potentially active biological processes. Such functional analysis of metagenomic data can be computationally demanding for high-throughput sequencing experiments. Instead, we can directly compare sequencing reads to a functionally annotated database. However, since reads frequently match multiple sequences equally well, analyses benefit from a hierarchical annotation tree, e.g. for taxonomic classification where reads are assigned to the lowest taxonomic unit.ResultsTo facilitate functional microbiome analysis, we re-purpose well-known taxonomic classification tools to allow us to perform direct functional sequencing read classification with the added benefit of a functional hierarchy. To enable this, we develop and present a tree-shaped functional hierarchy representing the molecular function subset of the Gene Ontology annotation structure. We use this functional hierarchy to replace the standard phylogenetic taxonomy used by the classification tools and assign query sequences accurately to the lowest possible molecular function in the tree. We demonstrate this with simulated and experimental datasets, where we reveal new biological insights.ConclusionsWe demonstrate that improved functional classification of metagenomic sequencing reads is possible by re-purposing a range of taxonomic classification tools that are already well-established, in conjunction with either protein or nucleotide reference databases. We leverage the advances in speed, accuracy and efficiency that have been made for taxonomic classification and translate these benefits for the rapid functional classification of microbiomes. While we focus on a specific set of commonly used methods, the functional annotation approach has broad applicability across other sequence classification tools. We hope that re-purposing becomes a routine consideration during bioinformatic resource development. Video abstract.
Project description:There is a growing evidence that antimalarial chloroquine could be re-purposed for cancer treatment. A dozen of clinical trials have been initiated within the past 10 years to test the potential of chloroquine as an adjuvant treatment for therapy-refractory cancers including glioblastoma, one of the most aggressive human cancers. While there is considerable evidence for the efficacy and safety of chloroquine the mechanisms underlying the tumor suppressive actions of this drug remain elusive. Up until recently, inhibition of the late stage of autophagy was thought to be the major mechanism of chloroquine-mediated cancer cells death. However, recent research provided compelling evidence that autophagy-inhibiting activities of chloroquine are dispensable for its ability to suppress tumor cells growth. These unexpected findings necessitate a further elucidation of the molecular mechanisms that are essential for anti-cancer activities of CHQ. This review discusses the versatile actions of chloroquine in cancer cells with particular focus on glioma cells.
Project description:Inhibitors of the DNA damage checkpoint kinase, Chk1, are highly effective as chemo- and radio-sensitizers in preclinical studies but are not well-tolerated by patients. We exploited the promiscuous nature of kinase inhibitors to screen 9 clinically relevant kinase inhibitors for their ability to sensitize pancreatic cancer cells to a sub-lethal concentration of gemcitabine. Bosutinib, dovitinib, and BEZ-235 were identified as sensitizers that abrogated the DNA damage checkpoint. We further characterized bosutinib, an FDA-approved Src/Abl inhibitor approved for chronic myelogenous leukemia. Unbeknownst to us, we used an isomer (Bos-I) that was unknowingly synthesized and sold to the research community as "authentic" bosutinib. In vitro and cell-based assays showed that both the authentic bosutinib and Bos-I inhibited DNA damage checkpoint kinases Chk1 and Wee1, with Bos-I showing greater potency. Imaging data showed that Bos-I forced cells to override gemcitabine-induced DNA damage checkpoint arrest and destabilized stalled replication forks. These inhibitors enhanced sensitivity to the DNA damaging agents' gemcitabine, cisplatin, and doxorubicin in pancreatic cancer cell lines. The in vivo efficacy of Bos-I was validated using cells derived directly from a pancreatic cancer patient's tumor. Notably, the xenograft studies showed that the combination of gemcitabine and Bos-I was significantly more effective in suppressing tumor growth than either agent alone. Finally, we show that the gatekeeper residue in Wee1 dictates its sensitivity to the 2 compounds. Our strategy to screen clinically relevant kinase inhibitors for off-target effects on cell cycle checkpoints is a promising approach to re-purpose drugs as chemosensitizers.
Project description:BackgroundVulnerable patients being cared for in hospital-at-home settings require safe disinfection of their medical devices, including nebulisers and other respiratory equipment. The scale of patients now being cared for in hospital-at-home settings as a result of COVID19 places huge pressure on hospital central sterile services departments (CSSDs) to provide consumable items to safely support such patients' care. This places new importance on the disinfection of mundane objects, including crockery, cutlery and frequently touched objects in the home environment. This study examined temperature performance of steam disinfectors and the consequences of potential operator misuse on the survival of 62 bacteria and yeast organisms.MethodsThermal performance of steam disinfectors was evaluated using calibrated thermocouple probes in multiple permutations of device usage with 62 test organisms.ResultsThermocouple data demonstrated disinfection A0 values of 6000 (upper layer) and 60 (lower layer). Steam disinfection of baby bottles had a thermal lethality of at least A0 = 600. Variation in disinfector temperatures were noted, depending on the geometric location of thermocouples. Additional notable temperature reductions occurred with device underfilling with suboptimal water volumes. Steam disinfection eradicated all 62 non-spore-forming Gram-positive, Gram-negative and yeast organisms tested and eradicated all organisms in the inner teat space of contaminated babies' dummies, rendering safe steam disinfection of babies' dummies.ConclusionDomestic steam disinfection offers an inexpensive, simple, versatile and widely available technology for the elimination of common non-spore-forming nosocomial pathogens and safe disinfection of medical devices, fomites and other mundane objects within the hospital-at-home scenario, thereby enhancing patient safety.
Project description:Dental healthcare personnel (DHCP) are subjected to microbe-containing aerosols and splatters in their everyday work. Safer work conditions must be developed to ensure the functioning of the healthcare system. By simulating dental procedures, we aimed to compare the virus-containing aerosol generation of four common dental instruments, and high-volume evacuation (HVE) in their mitigation. Moreover, we combined the detection of infectious viruses with RT-qPCR to form a fuller view of virus-containing aerosol spread in dental procedures. The air-water syringe produced the highest number of aerosols. HVE greatly reduced aerosol concentrations during procedures. The air-water syringe spread infectious virus-containing aerosols throughout the room, while other instruments only did so to close proximity. Additionally, infectious viruses were detected on the face shields of DHCP. Virus genomes were detected throughout the room with all instruments, indicating that more resilient viruses might remain infectious and pose a health hazard. HVE reduced the spread of both infectious viruses and viral genomes, however, it did not fully prevent them. We recommend meticulous use of HVE, a well-fitting mask and face shields in dental procedures. We advise particular caution when operating with the air-water syringe. Due to limited repetitions, this study should be considered a proof-of-concept report.
Project description:ObjectivesThis study evaluated particle spread associated with various common periodontal aerosol-generating procedures (AGPs) in simulated and clinical settings.Materials and methodsA simulation study visualized the aerosols, droplets, and splatter spread with and without high-volume suction (HVS, 325 L/min) during common dental AGPs, namely ultrasonic scaling, air flow prophylaxis, and implant drilling after fluorescein dye was added to the water irrigant as a tracer. Each procedure was repeated 10 times. A complementary clinical study measured the spread of contaminated particles within the dental operatory and quantified airborne protein dispersion following 10 min of ultrasonic supragingival scaling of 19 participants during routine periodontal treatment.ResultsThe simulation study data showed that air flow produced the highest amount of splatters and the ultrasonic scaler generated the most aerosol and droplet particles at 1.2 m away from the source. The use of HVS effectively reduced 37.5-96% of splatter generation for all three dental AGPs, as well as 82-93% of aerosol and droplet particles at 1.2 m for the ultrasonic scaler and air polisher. In the clinical study, higher protein levels above background levels following ultrasonic supragingival scaling were detected in fewer than 20% of patients, indicating minimal particle spread.ConclusionsWhile three common periodontal AGPs produce aerosols and droplet particles up to at least 1.2 m from the source, the use of HVS is of significant benefit. Routine ultrasonic supragingival scaling produced few detectable traces of salivary protein at various sites throughout the 10-min dental operatory.Clinical relevanceThe likelihood of aerosol spread to distant sites during common periodontal AGPs is greatly reduced by high-volume suction. Clinically, limited evidence of protein contaminants was found following routine ultrasonic scaling, suggesting that the the majority of the contamination consisits of the irrigant rather than organic matter from the oral cavity.
Project description:Faces are fundamental stimuli for social interactions since they provide significant information about people's identity and emotional states. With the outburst of the COVID-19 pandemic, global use of preventive measures, such as disposable surgical face masks (DSFMs), has been imposed. The massive use of DSFMs covering a large part of the face could interfere with identity and emotion recognition. Thus, the main aim of the current study was (i) to assess how DSFMs affect identity recognition (Experiment 1), (ii) how DSFMs affect emotion recognition (Experiment 2), and (iii) whether individual empathy levels correlate with emotion recognition with DSFMs. The potential relation between identity and emotion recognition with and without DSFMs was also investigated. Two tasks were administered to 101 healthy participants: (i) the Old-new face memory task aimed to assess whether the learning context (i.e., DSFMs on/off) affects recognition performance, whereas (ii) the Facial affect task explored DSFMs' effect on emotion recognition. Results from the former showed that the stimuli's features in the learning stage affect recognition performances; that is, faces wearing DSFMs were better recognized if wearing DSFMs at first exposure and vice versa. Results from the Facial affect task showed that DSFMs lead to reduced disgust, happiness, and sadness recognition. No significant correlation emerged between identity and emotion recognition. The Interpersonal Reactivity Index (IRI) was administered to assess affective and cognitive empathy; however, IRI scores did not correlate with either face memory recognition or facial affect recognition. Overall, our results demonstrate (a) a "context effect" for face memory with and without DSFMs; (b) a disruptive effect of DSFMs depending on the expressed emotion; and (c) no correlation between empathy and emotion recognition with DSFMs.