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1.
Phys Rev Lett ; 132(21): 218402, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38856284

ABSTRACT

Biological tissues transform between solid- and liquidlike states in many fundamental physiological events. Recent experimental observations further suggest that in two-dimensional epithelial tissues these solid-liquid transformations can happen via intermediate states akin to the intermediate hexatic phases observed in equilibrium two-dimensional melting. The hexatic phase is characterized by quasi-long-range (power-law) orientational order but no translational order, thus endowing some structure to an otherwise structureless fluid. While it has been shown that hexatic order in tissue models can be induced by motility and thermal fluctuations, the role of cell division and apoptosis (birth and death) has remained poorly understood, despite its fundamental biological role. Here we study the effect of cell division and apoptosis on global hexatic order within the framework of the self-propelled Voronoi model of tissue. Although cell division naively destroys order and active motility facilitates deformations, we show that their combined action drives a liquid-hexatic-liquid transformation as the motility increases. The hexatic phase is accessed by the delicate balance of dislocation defect generation from cell division and the active binding of disclination-antidisclination pairs from motility. We formulate a mean-field model to elucidate this competition between cell division and motility and the consequent development of hexatic order.


Subject(s)
Cell Division , Cell Movement , Models, Biological , Cell Movement/physiology , Cell Division/physiology , Apoptosis/physiology
2.
bioRxiv ; 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38659777

ABSTRACT

Within multicellular living systems, cells coordinate their positions with spatiotemporal accuracy to form various structures, setting the clock to control developmental processes and trigger maturation. These arrangements can be regulated by tissue topology, biochemical cues, as well as mechanical perturbations. However, the fundamental rules of how local cell packing order is regulated in forming three-dimensional (3D) multicellular architectures remain unclear. Furthermore, how cellular coordination evolves during developmental processes, and whether this cell patterning behavior is indicative of more complex biological functions, is largely unknown. Here, using human lung alveolospheres as a model system, by combining experiments and numerical simulations, we find that, surprisingly, cell packing behavior on alveolospheres resembles hard-disk packing but with increased randomness; the stiffer cell nuclei act as the hard disks surrounded by deformable cell bodies. Interestingly, we observe the emergence of topological packing order during alveolosphere growth, as a result of increasing nucleus-to-cell size ratio. Specifically, we find more hexagon-concentrated cellular packing with increasing bond orientational order, indicating a topological gas-to-liquid transition. Additionally, by osmotically changing the compactness of cells on alveolospheres, we observe that the variations in packing order align with the change of nucleus-to-cell size ratio. Together, our findings reveal the underlying rules of cell coordination and topological phases during human lung alveolosphere growth. These static packing characteristics are consistent with cell dynamics, together suggesting that better cellular packing stabilizes local cell neighborhoods and may regulate more complex biological functions such as organ development and cellular maturation.

3.
Article in English | MEDLINE | ID: mdl-38194382

ABSTRACT

A 3-D ultrasound (US) imaging technique has been studied to facilitate the diagnosis of spinal deformity without radiation. The objective of this article is to propose an assessment framework to automatically estimate spinal deformity in US spine images. The proposed framework comprises four major components, a US spine image generator, a novel transformer-based lightweight spine detector network, an angle evaluator, and a 3-D modeler. The principal component analysis (PCA) and discriminative scale space tracking (DSST) method are first adopted to generate the US spine images. The proposed detector is equipped with a redundancy queries removal (RQR) module and a regularization item to realize accurate and unique detection of spine images. Two clinical datasets, a total of 273 images from adolescents with idiopathic scoliosis, are used for the investigation of the proposed framework. The curvature is estimated by the angle evaluator, and the 3-D mesh model is established by the parametric modeling technique. The accuracy rate (AR) of the proposed detector can be achieved at 99.5%, with a minimal redundancy rate (RR) of 1.5%. The correlations between automatic curve measurements on US spine images from two datasets and manual measurements on radiographs are 0.91 and 0.88, respectively. The mean absolute difference (MAD) and standard deviation (SD) are 2.72° ± 2.14° and 2.91° ± 2.36° , respectively. The results demonstrate the effectiveness of the proposed framework to advance the application of the 3-D US imaging technique in clinical practice for scoliosis mass screening and monitoring.


Subject(s)
Scoliosis , Adolescent , Humans , Scoliosis/diagnostic imaging , Spine/diagnostic imaging , Radiography , Imaging, Three-Dimensional/methods , Ultrasonography
4.
Polymers (Basel) ; 15(14)2023 Jul 24.
Article in English | MEDLINE | ID: mdl-37514526

ABSTRACT

Heavy oil exploitation needs efficient viscosity reducers to reduce viscosity, and polyether carboxylate viscosity reducers have a significant viscosity reduction effect on heavy oil. Previous work has studied the effect of different side chain lengths on this viscosity reducer, and now a series of polyether carboxylate viscosity reducers, including APAD, APASD, APAS, APA, and AP5AD (the name of the viscosity reducer is determined by the name of the desired monomer), with different electrical properties have been synthesized to investigate the effect of their different electrical properties on viscosity reduction performance. Through the performance tests of surface tension, contact angle, emulsification, viscosity reduction, and foaming, it was found that APAD viscosity reducers had the best viscosity reduction performance, reducing the viscosity of heavy oil to 81 mPa·s with a viscosity reduction rate of 98.34%, and the worst viscosity reduction rate of other viscosity reducers also reached 97%. Additionally, APAD viscosity reducers have the highest emulsification rate, and the emulsion formed with heavy oil is also the most stable. The net charge of APAD was calculated from the molar ratio of the monomers and the total mass to minimize the net charge. While the net charge of other surfactants was higher. It shows that the amount of the surfactant's net charge affects the surfactant's viscosity reduction effect, and the smaller the net charge of the surfactant itself, the better the viscosity reduction effect.

5.
J Colloid Interface Sci ; 644: 275-284, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37120876

ABSTRACT

Aqueous rechargeable zinc-ion batteries (ARZIBs) are promising candidates for fast-charging energy-storage systems. The issues of stronger interactions between Zn2+ and the cathode for ultrafast ARZIBs can be partially addressed by enhancing mass transfer and ion diffusion of the cathode. Herein, via thermal oxidation for the first time, N-doped VO2 porous nanoflowers with short ion diffusion paths and improved electrical conductivity were synthesized as ARZIBs cathode materials. The introduction of nitrogen derived from the vanadium-based-zeolite imidazolyl framework (V-ZIF) contributes to enhanced electrical conductivity and faster ion diffusion, while the thermal oxidation of the VS2 precursor assists the final product in exhibiting a more stable three-dimensional nanoflower structure. In particular, the N-doped VO2 cathode shows excellent cycle stability and superior rate capability with the delivered capacities of 165.02 mAh g-1 and 85 mAh g-1, at 10 A g-1 and 30 A g-1, and the capacity retention of 91.4% after 2200 cycles and 99% after 9000 cycles, respectively. Remarkably, the battery takes less than 10 s to be fully charged at 30 A g-1. Hence, this work provides a new avenue for designing unique nanostructured vanadium oxides and developing electrode materials suitable for ultrafast charging.

6.
Asia Pac J Ophthalmol (Phila) ; 12(3): 284-292, 2023.
Article in English | MEDLINE | ID: mdl-36912572

ABSTRACT

PURPOSE: To establish a multilabel-based deep learning (DL) algorithm for automatic detection and categorization of clinically significant peripheral retinal lesions using ultrawide-field fundus images. METHODS: A total of 5958 ultrawide-field fundus images from 3740 patients were randomly split into a training set, validation set, and test set. A multilabel classifier was developed to detect rhegmatogenous retinal detachment, cystic retinal tuft, lattice degeneration, and retinal breaks. Referral decision was automatically generated based on the results of each disease class. t -distributed stochastic neighbor embedding heatmaps were used to visualize the features extracted by the neural networks. Gradient-weighted class activation mapping and guided backpropagation heatmaps were generated to investigate the image locations for decision-making by the DL models. The performance of the classifier(s) was evaluated by sensitivity, specificity, accuracy, F 1 score, area under receiver operating characteristic curve (AUROC) with 95% CI, and area under the precision-recall curve. RESULTS: In the test set, all categories achieved a sensitivity of 0.836-0.918, a specificity of 0.858-0.989, an accuracy of 0.854-0.977, an F 1 score of 0.400-0.931, an AUROC of 0.9205-0.9882, and an area under the precision-recall curve of 0.6723-0.9745. The referral decisions achieved an AUROC of 0.9758 (95% CI= 0.9648-0.9869). The multilabel classifier had significantly better performance in cystic retinal tuft detection than the binary classifier (AUROC= 0.9781 vs 0.6112, P < 0.001). The model showed comparable performance with human experts. CONCLUSIONS: This new DL model of a multilabel classifier is capable of automatic, accurate, and early detection of clinically significant peripheral retinal lesions with various sample sizes. It can be applied in peripheral retinal screening in clinics.


Subject(s)
Deep Learning , Humans , Fundus Oculi , Neural Networks, Computer , Algorithms , ROC Curve
7.
Biomedicines ; 11(2)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36831143

ABSTRACT

Ascites is a typical symptom of liver cirrhosis that is caused by a variety of liver diseases. Ascites severely affects the life quality of patients and needs long-term treatment. 25a is a specific urea transporter inhibitor with a diuretic effect that does not disturb the electrolyte balance. In this study, we aimed to determine the therapeutic effect of 25a on ascites with a dimethylnitrosamine (DMN)-induced cirrhotic rat model. It was found that 100 mg/kg of 25a significantly increased the daily urine output by 60% to 97% and reduced the daily abdominal circumference change by 220% to 260% in cirrhotic rats with a water intake limitation. The 25a treatment kept the serum electrolyte levels within normal ranges in cirrhotic rats. The H&E and Masson staining of liver tissue showed that 25a did not change the cirrhotic degree. A serum biochemical examination showed that 25a did not improve the liver function in cirrhotic rats. A Western blot analysis showed that 25a did not change the expression of fibrosis-related marker protein α-SMA, but significantly decreased the expressions of type I collagen in the liver of cirrhotic rats, indicating that 25a did not reverse cirrhosis, but could slow the cirrhotic progression. These data indicated that 25a significantly reduced ascites via diuresis without an electrolyte imbalance in cirrhotic rats. Our study provides a proof of concept that urea transporter inhibitors might be developed as novel diuretics to treat cirrhotic ascites.

8.
Clin J Am Soc Nephrol ; 18(4): 465-474, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36795940

ABSTRACT

BACKGROUND: People with advanced CKD are at high risk of mortality and morbidity from coronavirus disease 2019 (COVID-19). We measured rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe outcomes in a large population attending advanced CKD clinics during the first 21 months of the pandemic. We examined risk factors for infection and case fatality, and we assessed vaccine effectiveness in this population. METHODS: In this retrospective cohort study, we analyzed data on demographics, diagnosed SARS-CoV-2 infection rates, outcomes, and associated risk factors, including vaccine effectiveness, for people attending a province-wide network of advanced CKD clinics during the first four waves of the pandemic in Ontario, Canada. RESULTS: In a population of 20,235 patients with advanced CKD, 607 were diagnosed with SARS-CoV-2 infection over 21 months. The case fatality rate at 30 days was 19% overall but declined from 29% in the first wave to 14% in the fourth. Hospitalization and intensive care unit (ICU) admission rates were 41% and 12%, respectively, and 4% started long-term dialysis within 90 days. Significant risk factors for diagnosed infection on multivariable analysis included lower eGFR, higher Charlson Comorbidity Index, attending advanced CKD clinics for more than 2 years, non-White ethnicity, lower income, living in the Greater Toronto Area, and long-term care home residency. Being doubly vaccinated was associated with lower 30-day case fatality rate (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.03 to 0.52). Older age (OR, 1.06 per year; 95% CI, 1.04 to 1.08) and higher Charlson Comorbidity Index (OR, 1.11 per unit; 95% CI, 1.01 to 1.23) were associated with higher 30-day case fatality rate. CONCLUSIONS: People attending advanced CKD clinics and diagnosed with SARS-CoV-2 infection in the first 21 months of the pandemic had high case fatality and hospitalization rates. Fatality rates were significantly lower in those who were doubly vaccinated. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_04_10_CJN10560922.mp3.


Subject(s)
COVID-19 , Renal Insufficiency, Chronic , Humans , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2 , Retrospective Studies , Cohort Studies , Vaccine Efficacy , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/therapy , Ontario/epidemiology
9.
Int Immunopharmacol ; 112: 109208, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36087509

ABSTRACT

Pulmonary fibrosis is common in the development of inflammatory lung diseases with no effective clinical drug treatment currently. As an essential redox enzyme, thioredoxin (Trx) has been reported to be involved in pulmonary fibrosis, but the mechanism is to be revealed. Therefore, in bleomycin-indued pulmonary fibrosis model in C57 mice, Trx activity and nitrated Trx were examined.,p38-MAPK apoptosis pathway was determined in lung tissues. Additionally, before BLM administration, C57/BL6 mice were treated with aminoguanidine (AG, a peroxynitrite scavenger), recombinant human Trx-1 (rhTrx-1), or SIN-1 (a peroxynitrite donor) nitrated Trx-1 (N-Trx-1). In bleomycin (BLM)-induced pulmonary fibrosis model in C57/BL6 mice, we observed that nitrated Trx increased, while its activity decreased, with the increase of alveolar epithelial cells (AECs)apoptosis by p38-MAPK pathway. We demonstrated that AG or rhTrx-1, but not N-Trx-1 significantly reduced pulmonary fibrosis. Taken together, the results above revealed that blockade of Trx-1 nitration, or supplementation of exogenous rhTrx-1, might represent novel therapies to attenuate pulmonary fibrosis in idiopathic pulmonary fibrosis patients.


Subject(s)
Bleomycin , Idiopathic Pulmonary Fibrosis , Humans , Mice , Animals , Peroxynitrous Acid/metabolism , Thioredoxins/therapeutic use , Thioredoxins/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Idiopathic Pulmonary Fibrosis/chemically induced , Idiopathic Pulmonary Fibrosis/drug therapy , Nitrates/metabolism
10.
Polymers (Basel) ; 14(16)2022 Aug 18.
Article in English | MEDLINE | ID: mdl-36015624

ABSTRACT

Since there are not many studies on the application of polymeric surfactants in viscosity reduction emulsification of heavy oil, a series of polyether carboxylic acid-sulfonate polymeric surfactants were synthesized. The viscosity reduction performance and the effect of different chain lengths on the viscosity reduction effect were also investigated. The viscosity reduction, emulsification, wetting, and foaming performance tests showed that the viscosity reduction performance of this series of polymeric surfactants was excellent, with the viscosity reduction rate exceeding 95%, and the viscosity was reduced to 97 mPa·s by the polymeric surfactant with a molecular weight of 600 polyethers. It was also concluded that among the three surfactants with different side chains, the polymeric surfactant with a polyether molecular weight of 600, which is the medium side-chain length, had the best viscosity reduction performance. The study showed that the polyether carboxylic acid-sulfonate polymer surfactant had a promising application in the viscosity reduction of heavy oil.

11.
Front Public Health ; 10: 827835, 2022.
Article in English | MEDLINE | ID: mdl-35509509

ABSTRACT

Aim: We performed a comparative study to investigate the efficacy of closed system transfer devices (CSTDs) on the safe handling of injectable hazardous drugs (HDs). Methods: The exposure assessments of cyclophosphamide and cytarabine were performed under traditional or CSTDs. For preparation activity, chemotherapy contamination samples on protective equipment (such as gloves and masks) were collected. The contamination analysis was performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). A 6-item form was distributed monthly (form M1-M6, total 6 months) to assess the pharmacists' experience on ergonomics, encumbrance, and safety impression. Results: Totally, 96 wiping samples were collected throughout the study. The numbers of contaminated cyclophosphamide samples reduced under CSTD were -37.8, -41.6, -67.7, -47.3, and -22.9% and cytarabine were -12.3, -12.1, -20.6, -69.6, and -56.7% for left countertop, right countertop, medial glass, air-intake vent and door handle, as compared to traditional devices. The reduction was similar to pharmacist devices, i.e., -48.2 and -50.0% for masks and gloves cyclophosphamide contamination, -18.0 and -42.4% for cytarabine. This novel system could improve contamination on dispensing table, transfer container, and dispensing basket by -16.6, -6.0, and -22.3% for cyclophosphamide and -28.5, -22.5, and -46.2% for cytarabine. A high level of satisfaction was consistently associated with ergonomics for CSTD during the compounding process. Meanwhile, a slightly decreased satisfaction on ergonomics, encumbrance, and safety impression was observed for the traditional system between M2 and M3. Conclusion: Closed system transfer devices are offering progressively more effective alternatives to traditional ones and consequently decrease chemotherapy exposure risk on isolator surfaces.


Subject(s)
Antineoplastic Agents , Occupational Exposure , Antineoplastic Agents/analysis , Antineoplastic Agents/chemistry , Chromatography, Liquid , Cyclophosphamide/analysis , Cytarabine/analysis , Drug Compounding/methods , Occupational Exposure/analysis , Occupational Exposure/prevention & control , Protective Devices , Tandem Mass Spectrometry
12.
J Fish Biol ; 101(1): 204-212, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35567749

ABSTRACT

An 8 week feeding trial was carried out to investigate the effects of dietary nucleotides on growth performance, intestinal morphology, immune response and disease resistance of juvenile largemouth bass, Micropterus salmoides. Five grades of dietary nucleotide levels were designed as 0, 0.2, 0.4, 0.8 and 1.2 g kg-1 , respectively. Each group had 3 replicates, with 40 fish in each replicate. After the feeding experiment, 15 fish from each tank were infected with Aeromonas hydrophila for 14 days. The results indicated that fish fed the diets containing 0.4, 0.8 and 1.2 g kg-1 nucleotides had higher growth performance and feed utilization than those fed the control diet. Nonetheless, there were no significant differences in survival between all the groups, although fish fed the diets with all-level nucleotides obtained higher survival than those fed the control diet. Dietary nucleotides significantly affected the superoxide dismutase, acid phosphatase and catalase activities in serum but not the malondialdehyde content. Fish fed the 0.4 g kg-1 nucleotide diets had the highest fold height, enterocyte height and muscular layer thickness significantly. The average mortality of largemouth bass infected with A. hydrophila was significantly influenced by dietary nucleotides. The mortality was significantly higher in the control group (91.11%) and 0.02% nucleotide group (73.11%) followed by the other groups and lowest in the 0.8 g kg-1 nucleotide group. In summary, dietary 0.4-0.8 g kg-1 nucleotides promoted growth performance, enhanced immunity and improved intestinal morphology and disease resistance of largemouth bass.


Subject(s)
Bass , Fish Diseases , Animal Feed/analysis , Animals , Bass/physiology , Diet/veterinary , Dietary Supplements , Disease Resistance , Fish Diseases/prevention & control , Intestines , Nucleotides/pharmacology
13.
Clin Kidney J ; 15(3): 507-516, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35198157

ABSTRACT

BACKGROUND: Severely ill people with coronavirus disease 2019 (COVID-19) are at risk of acute kidney injury treated with renal replacement therapy (AKI-RRT). The understanding of the risk factors and outcomes for AKI-RRT is incomplete. METHODS: We prospectively collected data on the incidence, demographics, area of residence, time course, outcomes and associated risk factors for all COVID-19 AKI-RRT cases during the first two waves of the pandemic in Ontario, Canada. RESULTS: There were 271 people with AKI-RRT, representing 0.1% of all diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases. These included 10% of SARS-CoV-2 admissions to intensive care units (ICU). Median age was 65 years, with 11% <50 years, 76% were male, 47% non-White and 48% had diabetes. Overall, 59% resided in the quintile of Ontario neighborhoods with the greatest ethnocultural composition and 51% in the two lowest income quintile neighborhoods. Mortality was 58% at 30 days after RRT initiation, and 64% at 90 days. By 90 days, 20% of survivors remained RRT-dependent and 31% were still hospitalized. On multivariable analysis, people aged >70 years had higher mortality (odds ratio 2.4, 95% confidence interval 1.3, 4.6). Cases from the second versus the first COVID-19 wave were older, had more baseline comorbidity and were more likely to initiate RRT  >2 weeks after SARS-CoV-2 diagnosis (34% versus 14%; P < 0.001). CONCLUSIONS: AKI-RRT is common in COVID-19 ICU admissions. Residency in areas with high ethnocultural composition and lower socioeconomic status are strong risk factors. Late-onset AKI-RRT was more common in the second wave. Mortality is high and 90-day survivors have persisting high morbidity.

14.
Appl Biochem Biotechnol ; 193(11): 3753-3764, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34398422

ABSTRACT

Nuclease P1 (NP1) can hydrolyze nucleic acids into four 5'-mononucleotides, which are widely used in the pharmaceutical and food industries. In this paper, an aqueous two-phase system (ATPS) was developed to purify NP1 from Penicillium citrinum. Polyethylene glycol (PEG) and nucleotides salts were studied to form ATPSs, among which PEG3000/disodium guanosine monophosphate (GMPNa2) was researched, including the phase composition and pH. Using 14% (w/w) PEG3000 and 20% (w/w) GMPNa2 ATPS at pH 5.0, the best recovery and purification factor, 82.4% and 3.59, were obtained. The recovery of NP1 was 98.3% by the separation of ultrafiltration from the PEG-rich phase. The recycling use of GMPNa2 was also studied, and 95.1% of GMPNa2 in the salt-rich phase was obtained with the addition of ethanol as the solvent. These results showed that the ATPS was effective for purification of NP1.


Subject(s)
Fungal Proteins , Guanosine Monophosphate/chemistry , Penicillium/enzymology , Polyethylene Glycols/chemistry , Single-Strand Specific DNA and RNA Endonucleases , Fungal Proteins/chemistry , Fungal Proteins/isolation & purification , Single-Strand Specific DNA and RNA Endonucleases/chemistry , Single-Strand Specific DNA and RNA Endonucleases/isolation & purification
15.
ACS Appl Mater Interfaces ; 13(29): 34495-34506, 2021 Jul 28.
Article in English | MEDLINE | ID: mdl-34260222

ABSTRACT

Molybdenum disulfide (MoS2) has been extensively studied as a potential storage material for batteries. However, the electrochemical performance of MoS2 is far from ideal, and it exhibits severe activity fading resulting from its low electronic conductivity. The present work synthesizes nitrogen (N)-doped 1T MoS2 nanoflowers made of ultrathin nanosheets via the one-step hydrothermal sulfurization of a molybdenum-based metal-organic framework precursor. The resulting metallic phase shows improved conductivity and hydrophilicity, and characterization demonstrates that N doping effectively expands the interlayer spacing and increases the concentration of sulfur vacancies serving as defects. This material demonstrates high rate performance and good cycling stability when used as the cathode in an aqueous rechargeable zinc-ion battery (ARZIB). Its performance is superior to those of pure 1T MoS2 and 2H MoS2 synthesized with MoO3 as the molybdenum source. Ex situ X-ray photoelectron spectroscopy and X-ray diffraction analyses are performed to explore the reaction mechanism during charging and discharging of the N-doped 1T MoS2. A three-cell series ARZIB system containing this material is used to power five light-emitting diodes to confirm the possible practical applications of this technology.

17.
CMAJ ; 193(18): E655-E662, 2021 05 03.
Article in French | MEDLINE | ID: mdl-33941528

ABSTRACT

CONTEXTE: Les patients sous dialyse à long terme pourraient avoir un risque accru d'infection par le coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2), et de maladie et de mortalité associées. Nous avons voulu décrire l'incidence, les facteurs de risque et les issues de l'infection chez ces patients en Ontario (Canada). MÉTHODES: Nous avons utilisé des ensembles de données reliées pour comparer les caractéristiques de la maladie et la mortalité chez les patients sous dialyse à long terme en Ontario qui ont testé positif pour le SRAS-CoV-2 et ceux qui n'ont pas développé d'infection, entre le 12 mars et le 20 août 2020. Nous avons recueilli des données sur l'infection par le SRAS-CoV-2 de manière prospective. Nous avons évalué les facteurs de risque d'infection et de mortalité par des analyses de régression logistique multivariées. RÉSULTATS: Pendant la période à l'étude, 187 patients dialysés sur 12 501 (1,5 %) ont reçu un diagnostic d'infection par le SRAS-CoV-2. Parmi eux, 117 (62,6 %) ont été hospitalisés, et le taux de mortalité était de 28,3 %. Les facteurs prédictifs significatifs associés à l'infection incluaient l'hémodialyse dans un centre plutôt que la dialyse à domicile (rapport de cotes [RC] 2,54; intervalle de confiance [IC] à 95 % 1,59­4,05), le fait de vivre dans un établissement de soins de longue durée (RC 7,67; IC à 95 % 5,30­11,11), le fait d'habiter la région du Grand Toronto (RC 3,27; IC à 95 % 2,21­4,80), les ethnicités Noire (RC 3,05; IC à 95 % 1,95­4,77), du sous-continent indien (RC 1,70; IC à 95 % 1,02­2,81) et autres non blanches (RC 2,03; IC à 95 % 1,38­2,97) et les quintiles de revenu inférieurs (RC 1,82; IC à 95 % 1,15­2,89). INTERPRÉTATION: Les patients sous dialyse à long terme sont exposés à un risque accru d'infection par le SRAS-CoV-2 et de mortalité due à la maladie à coronavirus 2019. Il faudra travailler à éliminer les facteurs de risque d'infection et vacciner ces patients en priorité.

18.
Plant Physiol ; 185(3): 1148-1165, 2021 04 02.
Article in English | MEDLINE | ID: mdl-33793918

ABSTRACT

Heat shock proteins (HSPs) function as molecular chaperones and are key components responsible for protein folding, assembly, translocation, and degradation under stress conditions. However, little is known about how HSPs stabilize proteins and membranes in response to different hormonal or environmental cues in plants. Here, we combined molecular, biochemical, and genetic approaches to elucidate the involvement of cytosolic HSP70-3 in plant stress responses and the interplay between HSP70-3 and plasma membrane (PM)-localized phospholipase Dδ (PLDδ) in Arabidopsis (Arabidopsis thaliana). Analysis using pull-down, coimmunoprecipitation, and bimolecular fluorescence complementation revealed that HSP70-3 specifically interacted with PLDδ. HSP70-3 bound to microtubules, such that it stabilized cortical microtubules upon heat stress. We also showed that heat shock induced recruitment of HSP70-3 to the PM, where HSP70-3 inhibited PLDδ activity to mediate microtubule reorganization, phospholipid metabolism, and plant thermotolerance, and this process depended on the HSP70-3-PLDδ interaction. Our results suggest a model whereby the interplay between HSP70-3 and PLDδ facilitates the re-establishment of cellular homeostasis during plant responses to external stresses and reveal a regulatory mechanism in regulating membrane lipid metabolism.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , HSP70 Heat-Shock Proteins/metabolism , Phospholipases/metabolism , Cell Membrane/metabolism , Heat-Shock Response/physiology , Microtubules/metabolism , Phospholipase D/metabolism
19.
CMAJ ; 193(8): E278-E284, 2021 Feb 22.
Article in English | MEDLINE | ID: mdl-33542093

ABSTRACT

BACKGROUND: Patients undergoing long-term dialysis may be at higher risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and of associated disease and mortality. We aimed to describe the incidence, risk factors and outcomes for infection in these patients in Ontario, Canada. METHODS: We used linked data sets to compare disease characteristics and mortality between patients receiving long-term dialysis in Ontario who were diagnosed SARS-CoV-2 positive and those who did not acquire SARS-CoV-2 infection, between Mar. 12 and Aug. 20, 2020. We collected data on SARS-CoV-2 infection prospectively. We evaluated risk factors for infection and death using multivariable logistic regression analyses. RESULTS: During the study period, 187 (1.5%) of 12 501 patients undergoing dialysis were diagnosed with SARS-CoV-2 infection. Of those with SARS-CoV-2 infection, 117 (62.6%) were admitted to hospital and the case fatality rate was 28.3%. Significant predictors of infection included in-centre hemodialysis versus home dialysis (odds ratio [OR] 2.54, 95% confidence interval [CI] 1.59-4.05), living in a long-term care residence (OR 7.67, 95% CI 5.30-11.11), living in the Greater Toronto Area (OR 3.27, 95% CI 2.21-4.80), Black ethnicity (OR 3.05, 95% CI 1.95-4.77), Indian subcontinent ethnicity (OR 1.70, 95% CI 1.02-2.81), other non-White ethnicities (OR 2.03, 95% CI 1.38-2.97) and lower income quintiles (OR 1.82, 95% CI 1.15-2.89). INTERPRETATION: Patients undergoing long-term dialysis are at increased risk of SARS-CoV-2 infection and death from coronavirus disease 2019. Special attention should be paid to addressing risk factors for infection, and these patients should be prioritized for vaccination.


Subject(s)
COVID-19/epidemiology , Hemodialysis Units, Hospital/statistics & numerical data , Kidney Failure, Chronic/therapy , Renal Dialysis/statistics & numerical data , Adult , COVID-19/therapy , Disease Transmission, Infectious/prevention & control , Female , Humans , Kidney Failure, Chronic/epidemiology , Male , Middle Aged , Ontario , Risk Factors
20.
Nanotechnology ; 32(22)2021 Mar 09.
Article in English | MEDLINE | ID: mdl-33618340

ABSTRACT

Defects caused by the structural disorder of perovskites and voltage loss resulting from mismatched band structure are important issues to address to improve the performance of carbon-based perovskite solar cells. Different from the conventional approaches of additive-based passivation of perovskite precursors and introducing a hole-transport layer between the perovskite layer and carbon electrode, herein we report a defect-healing method using phenethyl ammonium iodide (PEAI) treatment and band-structure modification using high-work-function inorganic copper phthalocyanine (CuPc). Because of its relatively smoother surfaces and lower defect content, the optimized device after PEAI-based passivation of the perovskite achieves a power conversion efficiency (PCE) of 11.74%. The PCE is further raised to 13.41% through the auxiliary energy-level matching and high hole extraction abilities of the CuPc-modified carbon electrode. The best-performing device exhibits excellent moisture tolerance and thermal stability with minor current density-voltage hysteresis.

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