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1.
Biomaterials ; 313: 122803, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39232334

RESUMEN

Bacteria-infected wounds pose challenges to healing due to persistent infection and associated damage to nerves and vessels. Although sonodynamic therapy can help kill bacteria, it is limited by the residual oxidative stress, resulting in prolonged inflammation. To tackle these barriers, novel 4 octyl itaconate-coated Li-doped ZnO/PLLA piezoelectric composite microfibers are developed, offering a whole-course "targeted" treatment under ultrasound therapy. The inclusion of Li atoms causes the ZnO lattice distortion and increases the band gap, enhancing the piezoelectric and sonocatalytic properties of the composite microfibers, collaborated by an aligned PLLA conformation design. During the infection and inflammation stages, the piezoelectric microfibers exhibit spatiotemporal-dependent therapeutic effects, swiftly eliminating over 94.2 % of S. aureus within 15 min under sonodynamic therapy. Following this phase, the microfibers capture reactive oxygen species and aid macrophage reprogramming, restoring mitochondrial function, achieving homeostasis, and shortening inflammation cycles. As the wound progresses through the healing stages, bioactive Zn2+ and Li + ions are continuously released, improving cell recruitment, and the piezoelectrical stimulation enhances wound recovery with neuro-vascularization. Compared to commercially available dressings, our microfibers accelerate the closure of rat wounds (Φ = 15 mm) without scarring in 12 days. Overall, this "one stone, four birds" wound management strategy presents a promising avenue for infected wound therapy.


Asunto(s)
Terapia por Ultrasonido , Cicatrización de Heridas , Animales , Cicatrización de Heridas/efectos de los fármacos , Terapia por Ultrasonido/métodos , Ratas Sprague-Dawley , Ratas , Staphylococcus aureus/efectos de los fármacos , Óxido de Zinc/química , Ratones , Estimulación Eléctrica , Masculino , Infecciones Estafilocócicas/terapia , Poliésteres/química , Especies Reactivas de Oxígeno/metabolismo , Terapia por Estimulación Eléctrica/métodos , Neovascularización Fisiológica/efectos de los fármacos
2.
Nature ; 633(8031): 828-834, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39322733

RESUMEN

Climate warming has caused a widespread increase in extreme fire weather, making forest fires longer-lived and larger1-3. The average forest fire size in Canada, the USA and Australia has doubled or even tripled in recent decades4,5. In return, forest fires feed back to climate by modulating land-atmospheric carbon, nitrogen, aerosol, energy and water fluxes6-8. However, the surface climate impacts of increasingly large fires and their implications for land management remain to be established. Here we use satellite observations to show that in temperate and boreal forests in the Northern Hemisphere, fire size persistently amplified decade-long postfire land surface warming in summer per unit burnt area. Both warming and its amplification with fire size were found to diminish with an increasing abundance of broadleaf trees, consistent with their lower fire vulnerability compared with coniferous species9,10. Fire-size-enhanced warming may affect the success and composition of postfire stand regeneration11,12 as well as permafrost degradation13, presenting previously overlooked, additional feedback effects to future climate and fire dynamics. Given the projected increase in fire size in northern forests14,15, climate-smart forestry should aim to mitigate the climate risks of large fires, possibly by increasing the share of broadleaf trees, where appropriate, and avoiding active pyrophytes.


Asunto(s)
Bosques , Calentamiento Global , Árboles , Incendios Forestales , Incendios Forestales/estadística & datos numéricos , Árboles/crecimiento & desarrollo , Calentamiento Global/estadística & datos numéricos , Agricultura Forestal , Estaciones del Año , Incendios , Taiga
3.
Nutrients ; 16(17)2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39275267

RESUMEN

Ensuring optimal infant nutrition is crucial for the health and development of children. Many infants aged 0-6 months are fed with infant formula rather than breast milk. Research on cancer cell lines and animal models is limited to examining the nutrition effects of formula and breast milk, as it does not comprehensively consider absorption, metabolism, and the health and social determinants of the infant and its physiology. Our study utilized small intestine organoids induced from human embryo stem cell (ESC) to compare the nutritional effects of breast milk from five donors during their postpartum lactation period of 1-6 months and three types of Stage 1 infant formulae from regular retail stores. Using transcriptomics and untargeted metabolomics approaches, we focused on the differences such as cell growth and development, cell junctions, and extracellular matrix. We also analyzed the roles of pathways including AMPK, Hippo, and Wnt, and identified key genes such as ALPI, SMAD3, TJP1, and WWTR1 for small intestine development. Through observational and in-vitro analysis, our study demonstrates ESC-derived organoids might be a promising model for exploring nutritional effects and underlying mechanisms.


Asunto(s)
Fórmulas Infantiles , Intestino Delgado , Leche Humana , Organoides , Humanos , Leche Humana/química , Intestino Delgado/metabolismo , Organoides/metabolismo , Lactante , Recién Nacido , Femenino , Metabolómica/métodos , Fenómenos Fisiológicos Nutricionales del Lactante , Lactancia , Transcriptoma , Multiómica
4.
Food Res Int ; 195: 114999, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39277258

RESUMEN

Breast milk is widely acknowledged as the ideal nutritional resource for infants and can well meet the nutritional requirements for baby's growth and development. Infant formula is a substitute for breast milk, designed to closely mimic its composition and function for breast milk. Most of the previous studies used tumor colorectal cancer cell lines to study the nutritional potency of formula and its components, so realistic data closer to the baby could not be obtained. Small intestinal organoids, derived from differentiated human embryonic stem cells, can be used to simulate nutrient absorption and metabolism in vitro. In this experiment, we used small intestinal organoids to compare the nutrient absorption and metabolism of three infant formulae for 0-6 months with breast milk samples. Transcriptome and metabolome sequencing methods were used to analyze the differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs). The pathways related to DEGs, DEMs were enriched using GO, KEGG, GSEA and other methods to investigate their biological characteristics. We have found that both formula and breast milk promote the development of the infant's immune system, nutrient absorption and intestinal development. In PMH1 we found that the addition of oligofructose to milk powder promoted lipid metabolism and absorption. In PMH2 we found that whey protein powder favours the development of the immune system in infants. In PMH3 we found that oligogalactans may act on the brain-gut axis by regulating the intestinal flora, thereby promoting axon formation and neural development. By linking these biological properties of the milk powder with its composition, we confirmed the effects of added ingredients on the growth and development of infants. Also, we demonstrated the validity of small intestine organoids as a model for absorption and digestion in vitro. Through the above analyses, the advantages and disadvantages of the roles of formula and breast milk in the growth and metabolism of infants were also compared.


Asunto(s)
Fórmulas Infantiles , Intestino Delgado , Metaboloma , Leche Humana , Organoides , Transcriptoma , Humanos , Leche Humana/metabolismo , Leche Humana/química , Organoides/metabolismo , Intestino Delgado/metabolismo , Intestino Delgado/citología , Lactante , Oligosacáridos/metabolismo , Recién Nacido , Absorción Intestinal , Femenino , Proteína de Suero de Leche/metabolismo
5.
Nat Commun ; 15(1): 6764, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39164286

RESUMEN

The 2023 wildfire season in Canada was unprecedented in its scale and intensity, spanning from mid-April to late October and across much of the forested regions of Canada. Here, we summarize the main causes and impacts of this exceptional season. The record-breaking total area burned (~15 Mha) can be attributed to several environmental factors that converged early in the season: early snowmelt, multiannual drought conditions in western Canada, and the rapid transition to drought in eastern Canada. Anthropogenic climate change enabled sustained extreme fire weather conditions, as the mean May-October temperature over Canada in 2023 was 2.2 °C warmer than the 1991-2020 average. The impacts were profound with more than 200 communities evacuated, millions exposed to hazardous air quality from smoke, and unmatched demands on fire-fighting resources. The 2023 wildfire season in Canada not only set new records, but highlights the increasing challenges posed by wildfires in Canada.

6.
Food Funct ; 15(18): 9191-9209, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39158038

RESUMEN

Infant formulas are designed to provide sufficient energy and the necessary nutrients to support the growth and development of newborns. Currently, research on the functions of formula milk powder focuses on clinical research and cell experiments, and there were many cell experiments that investigated the effect of infant formulas on cellular growth. However, most of the cells used are tumor cell lines, which are unable to simulate the real digestion process of an infant. In this study, we innovatively proposed a method that integrates human small intestinal organoids (SIOs) with transcriptomics and metabolomics analysis. We induced directed differentiation of human embryonic stem cells into SIOs and simulated the intestinal environment of newborns with them. Then, three kinds of 1-stage infant formulas from the same brand were introduced to simulate the digestion, absorption, and metabolism of the infant intestine. The nutritional value of each formula milk powder was examined by multi-omics sequencing methods, including transcriptomics and metabolomics analysis. Results showed that there were significant alterations in gene expression and metabolites in the three groups of SIOs after absorbing different infant formulas. By analyzing transcriptome and metabolome data, combined with GO, KEGG, and GSEA analysis, we demonstrated the ability of SIOs to model the different aspects of the developing process of the intestine and discovered the correlation between formula components and their effects, including Lactobacillus lactis and lactoferrin. The study reveals the effect and mechanisms of formula milk powder on the growth and development of infant intestines and the formation of immune function. Furthermore, our method can help to construct a multi-level assessment model, detect the effects of nutrients, and evaluate the interactions between nutrients, which is helpful for future research and development of infant powders.


Asunto(s)
Fórmulas Infantiles , Intestino Delgado , Metabolómica , Organoides , Transcriptoma , Humanos , Intestino Delgado/metabolismo , Organoides/metabolismo , Lactante , Recién Nacido
7.
Sci Data ; 11(1): 764, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38992042

RESUMEN

Satellite data are effective for mapping wildfires, particularly in remote locations where monitoring is rare. Geolocated fire detections can be used for enhanced fire management and fire modelling through daily fire progression mapping. Here we present the Canadian Fire Spread Dataset (CFSDS), encompassing interpolated progressions for fires >1,000 ha in Canada from 2002-2021, representing the day-of-burning and 50 environmental covariates for every pixel. Day-of-burning was calculated by ordinary kriging of active fire detections from the Moderate Resolution Imaging Spectroradiometer and the Visible Infrared Imaging Radiometer Suite, enabling a substantial improvement in coverage and resolution over existing datasets. Day of burning at each pixel was used to identify environmental conditions of burning such as daily weather, derived weather metrics, topography, and forest fuels characteristics. This dataset can be used in a broad range of research and management applications, such as retrospective analysis of fire spread, as a benchmark dataset for validating statistical or machine-learning models, and for forecasting the effects of climate change on fire activity.

8.
Chin Med J (Engl) ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38879805

RESUMEN

BACKGROUND: G protein-coupled receptor kinase 2 (GRK2) could participate in the regulation of diverse cells via interacting with non-G-protein-coupled receptors. In the present work, we explored how paroxetine, a GRK2 inhibitor, modulates the differentiation and activation of immune cells in rheumatoid arthritis (RA). METHODS: The blood samples of healthy individuals and RA patients were collected between July 2021 and March 2022 from the First Affiliated Hospital of Anhui Medical University. C57BL/6 mice were used to induce the collagen-induced arthritis (CIA) model. Flow cytometry analysis was used to characterize the differentiation and function of dendritic cells (DCs)/T cells. Co-immunoprecipitation was used to explore the specific molecular mechanism. RESULTS: In patients with RA, high expression of GRK2 in peripheral blood lymphocytes, accompanied by the increases of phosphatidylinositol 3 kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR). In animal model, a decrease in regulatory T cells (Tregs), an increase in the cluster of differentiation 8 positive (CD8+) T cells, and maturation of DCs were observed. Paroxetine, when used in vitro and in CIA mice, restrained the maturation of DCs and the differentiation of CD8+ T cells, and induced the proportion of Tregs. Paroxetine inhibited the secretion of pro-inflammatory cytokines, the expression of C-C motif chemokine receptor 7 in DCs and T cells. Simultaneously, paroxetine upregulated the expression of programmed death ligand 1, and anti-inflammatory cytokines. Additionally, paroxetine inhibited the PI3K-AKT-mTOR metabolic pathway in both DCs and T cells. This was associated with a reduction in mitochondrial membrane potential and changes in the utilization of glucose and lipids, particularly in DCs. Paroxetine reversed PI3K-AKT pathway activation induced by 740 Y-P (a PI3K agonist) through inhibiting the interaction between GRK2 and PI3K in DCs and T cells. CONCLUSION: Paroxetine exerts an immunosuppressive effect by targeting GRK2, which subsequently inhibits the metabolism-related PI3K-AKT-mTOR pathway of DCs and T cell in RA.

9.
Bone Rep ; 21: 101778, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38939472

RESUMEN

Purpose: This study aimed to analyze the current medication treatment status for women with osteoporosis (OP) based on real-world prescription data from 2016 to 2021 in Chinese nine cities' tertiary Grade A hospital and systematically describe the medication treatment patterns in women with OP. Methods: Prescription information for female OP patients in nine cities (Beijing, Shanghai, Guangzhou, Hangzhou, Tianjin, Zhengzhou, Chengdu, Shenyang, Harbin) was extracted from the Hospital Prescription Analysis Collaboration Project Database of the Hospital Pharmacy Professional Committee of the Chinese Pharmaceutical Association. Statistical analysis was conducted to evaluate demographic characteristics and medication treatment patterns. Results: A total of 669,505 prescriptions for medication treatment of female OP patients were included in this study. The majority of patients were aged 60 to 99 years (69.79 %) followed by 50 to 59 years (18.81 %) and 40 to 49 years (6.69 %). Geographically, the highest concentration of patients was in North China (Beijing, Tianjin) (43.05 %) followed by East China (Shanghai, Hangzhou) (31.43 %). The top three prescribed medications were active vitamin D and its analogs (40.78 %), calcium supplements (32.51 %), and bisphosphonates (18.75 %). The prescription frequency of menopausal hormone therapy (MHT) was 0.31 %. The proportion of female OP patients receiving monotherapy and two drug combinations therapy is equivalent (about 37 %). Conclusion: The diagnosis and treatment of female OP patients in China showed regional variations. The most commonly prescribed medications for this population were calcitriol, calcium carbonate with vitamin D3, and alendronate sodium with vitamin D3. The use of MHT was relatively limited.

10.
Bioact Mater ; 39: 74-105, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38783927

RESUMEN

Mg is a typical biodegradable metal widely used for biomedical applications due to its considerable mechanical properties and bioactivity. Biodegradable polymers have attracted great interest owing to their favorable processability and inclusiveness. However, it is challenging for the degradation rates of Mg or polymers to precisely match tissue repair processes, and the significant changes in local pH during degradation hinder tissue repair. The concept of combining Mg with polymers is proposed to overcome the shortcomings of materials, aiming to meet repair needs from various aspects such as mechanics and biology. Therefore, it is essential to systematically understand the behavior of biodegradable Mg/polymer composite (BMPC) from the design, manufacturing, mechanical properties, degradation, and biological effects. In this review, we elaborate on the design concepts and manufacturing strategies of high-strength BMPC, the "structure-function" relationship between the microstructures and mechanical properties of composites, the variation in the degradation rate due to endogenous and exogenous factors, and the establishment of advanced degradation research platform. Additionally, the interplay among composite components during degradation and the biological function of composites under non-responsive/stimuli-responsive platforms are also discussed. Finally, we hope that this review will benefit future clinical applications of "structure-function" integrated biomaterials.

11.
Biochem Soc Trans ; 52(3): 1363-1372, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38747731

RESUMEN

The zinc finger protein of the cerebellum (ZIC) family comprises five members (ZIC1-5), homologous with the odd-paired (OPA) gene in Drosophila melanogila. These transcription factors contain five Cys2His zinc finger domains, constituting one of the most abundant transcription factor families in human cells. ZIC proteins significantly contribute to transcriptional regulation and chromatin remodeling. As a member of the ZIC family, ZIC5 is essential for animal growth and development. Numerous studies have investigated the connection between ZIC proteins and cancer as well as tumor metastases in recent years. Many studies have found that within tumor tissues, the transcription and translation processes increase the expression of ZIC5 which is linked to tumor aggressiveness. This review aims to provide an objective summary of the impact of ZIC5 on tumor metastasis and consider the potential application of ZIC5 targets in both tumor therapy and the early detection of cancer.


Asunto(s)
Metástasis de la Neoplasia , Neoplasias , Factores de Transcripción , Humanos , Factores de Transcripción/metabolismo , Animales , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica
12.
J Biomater Appl ; 39(3): 165-178, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38816339

RESUMEN

Addressing fracture-related infections (FRI) and impaired bone healing remains a significant challenge in orthopedics and stomatology. Researchers aim to address this issue by utilizing biodegradable biomaterials, such as magnesium/poly lactic acid (Mg/PLA) composites, to offer antibacterial properties during the degradation of biodegradable implants. Existing Mg/PLA composites often lack sufficient Mg content, hindering their ability to achieve the desired antibacterial effect. Additionally, research on the anti-inflammatory effects of these composites during late-stage degradation is limited. To strengthen mechanical properties, bolster antibacterial efficacy, and enhance anti-inflammatory capabilities during degradation, we incorporated elevated Mg content into PLA to yield Mg/PLA composites. These composites underwent in vitro degradation studies, cellular assays, bacterial tests, and simulation of the PLA degradation microenvironment. 20 wt% and 40 wt% Mg/PLA composites displayed significant antibacterial properties, with three composites exhibiting notable anti-inflammatory effects. In contrast, elevated Mg content detrimentally impacted mechanical properties. The findings suggest that Mg/PLA composites hold promise in augmenting antibacterial and anti-inflammatory attributes within polymers, potentially serving as temporary regenerative materials for treating bone tissue defects complicated by infections.


Asunto(s)
Implantes Absorbibles , Antibacterianos , Antiinflamatorios , Magnesio , Poliésteres , Magnesio/química , Antibacterianos/farmacología , Antibacterianos/química , Poliésteres/química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Staphylococcus aureus/efectos de los fármacos , Animales , Ensayo de Materiales , Ratones , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana
13.
Front Pharmacol ; 15: 1353293, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38694907

RESUMEN

Introduction: We investigated trends in the use of therapeutic drugs for pregnant patients with rheumatic diseases in nine Chinese cities (Beijing, Chengdu, Guangzhou, Harbin, Hangzhou, Shanghai, Shenyang, Tianjin, and Zhengzhou) to provide a reference for drug use in clinic. Methods: Outpatient prescription data for pregnant patients diagnosed with rheumatic diseases in nine cities across China in 2016-2021 were extracted from the Hospital Prescription Cooperation Project of the Hospital Pharmacy Professional Committee of the Chinese Pharmaceutical Association. A retrospective analysis was then performed, incorporating data on patient age, defined daily doses (DDDs), defined daily cost (DDC), and other metrics. Results: In 2016-2020, more than 70% of the pregnant patients diagnosed with rheumatic diseases in these nine cities were 25 to < 35 years of age. The most common rheumatic diseases during pregnancy were antiphospholipid antibody syndrome (APS) and systemic lupus erythematosus (SLE). In terms of the routine use of daily therapeutic drugs, the DDDs of low molecular weight heparins (LMWHs), glucocorticoids, and immunosuppressive agents dominated the top three. Intravenous immunoglobulin (IVIG) and tumor necrosis factor inhibitors (TNFi) have been used since 2019 and had been in the forefront of the DDC. Conclusion: The number and total cost of prescriptions for therapeutic drugs of pregnancy complicated by rheumatic diseases, have increased significantly over the study interval. Conventional therapeutic drugs, especially glucocorticoids, LMWHs, and hydroxychloroquine were the most widely used drugs in pregnant patients with rheumatic diseases. However, IVIG and TNFi, relatively high cost, have shown gradual increases in clinical use since 2019.

14.
Mol Biol Rep ; 51(1): 512, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622483

RESUMEN

Bacterial enteritis has a substantial role in contributing to a large portion of the global disease burden and serves as a major cause of newborn mortality. Despite advancements gained from current animal and cell models in improving our understanding of pathogens, their widespread application is hindered by apparent drawbacks. Therefore, more precise models are imperatively required to develop more accurate studies on host-pathogen interactions and drug discovery. Since the emergence of intestinal organoids, massive studies utilizing organoids have been conducted to study the pathogenesis of bacterial enteritis, revealing new mechanisms and validating established ones. In this review, we focus on the advancements of several bacterial pathogenesis mechanisms observed in intestinal organoid/enteroid models, exploring the host response and bacterial effectors during the infection process. Finally, we address the features that warrant additional investigation or could be enhanced in existing organoid models in order to guide future research endeavors.


Asunto(s)
Infecciones Bacterianas , Enteritis , Animales , Intestinos/microbiología , Bacterias , Organoides
15.
Sci Data ; 11(1): 352, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589374

RESUMEN

We assembled the first gridded burned area (BA) database of national wildfire data (ONFIRE), a comprehensive and integrated resource for researchers, non-government organisations, and government agencies analysing wildfires in various regions of the Earth. We extracted and harmonised records from different regions and sources using open and reproducible methods, providing data in a common framework for the whole period available (starting from 1950 in Australia, 1959 in Canada, 1985 in Chile, 1980 in Europe, and 1984 in the United States) up to 2021 on a common 1° × 1° grid. The data originate from national agencies (often, ground mapping), thus representing the best local expert knowledge. Key opportunities and limits in using this dataset are discussed as well as possible future expansions of this open-source approach that should be explored. This dataset complements existing gridded BA data based on remote sensing and offers a valuable opportunity to better understand and assess fire regime changes, and their drivers, in these regions. The ONFIRE database can be freely accessed at https://zenodo.org/record/8289245 .

16.
Nature ; 627(8003): 321-327, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38480963

RESUMEN

Overnight fires are emerging in North America with previously unknown drivers and implications. This notable phenomenon challenges the traditional understanding of the 'active day, quiet night' model of the diurnal fire cycle1-3 and current fire management practices4,5. Here we demonstrate that drought conditions promote overnight burning, which is a key mechanism fostering large active fires. We examined the hourly diurnal cycle of 23,557 fires and identified 1,095 overnight burning events (OBEs, each defined as a night when a fire burned through the night) in North America during 2017-2020 using geostationary satellite data and terrestrial fire records. A total of 99% of OBEs were associated with large fires (>1,000 ha) and at least one OBE was identified in 20% of these large fires. OBEs were early onset after ignition and OBE frequency was positively correlated with fire size. Although warming is weakening the climatological barrier to night-time fires6, we found that the main driver of recent OBEs in large fires was the accumulated fuel dryness and availability (that is, drought conditions), which tended to lead to consecutive OBEs in a single wildfire for several days and even weeks. Critically, we show that daytime drought indicators can predict whether an OBE will occur the following night, which could facilitate early detection and management of night-time fires. We also observed increases in fire weather conditions conducive to OBEs over recent decades, suggesting an accelerated disruption of the diurnal fire cycle.


Asunto(s)
Oscuridad , Sequías , Incendios Forestales , Sequías/estadística & datos numéricos , Ecosistema , América del Norte , Incendios Forestales/estadística & datos numéricos
17.
Glob Chang Biol ; 30(3): e17221, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38450880

RESUMEN

Communities interspersed throughout the Canadian wildland are threatened by fires that have become bigger and more frequent in some parts of the country in recent decades. Identifying the fireshed (source area) and pathways from which wildland fire may ignite and spread from the landscape to a community is crucial for risk-reduction strategy and planning. We used outputs from a fire simulation model, including fire polygons and rate of spread, to map firesheds, fire pathways and corridors and spread distances for 1980 communities in the forested areas of Canada. We found fireshed sizes are larger in the north, where the mean distances between ecumene and fireshed perimeters were greater than 10 km. The Rayleigh Z test indicated that simulated fires around a large proportion of communities show significant directional trends, and these trends are stronger in the Boreal Plains and Shields than in the Rocky Mountain area. The average distance from which fire, when spreading at the maximum simulated rate, could reach the community perimeter was approximately 5, 12 and 18 km in 1, 2 and 3 days, respectively. The average daily spread distances increased latitudinally, from south to north. Spread distances were the shortest in the Pacific Maritime, Atlantic Maritime and Boreal Plains Ecozones, implying lower rates of spread compared to the rest of the country. The fire corridors generated from random ignitions and from ignitions predicted from local fire history differ, indicating that factors other than fuel (e.g. fire weather, ignition pattern) play a significant role in determining the direction that fires burn into a community.


Asunto(s)
Desastres , Incendios Forestales , Canadá , Simulación por Computador , Bosques
18.
J Cell Physiol ; 239(5): e31216, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38327128

RESUMEN

c-Fos, a member of the immediate early gene, serves as a widely used marker of neuronal activation induced by various types of brain damage. In addition, c-Fos is believed to play a regulatory role in DNA damage repair. This paper reviews the literature on c-Fos' involvement in the regulation of DNA damage repair and indicates that genes of the Fos family can be induced by various forms of DNA damage. In addition, cells lacking c-Fos have difficulties in DNA repair. c-Fos is involved in tumorigenesis and progression as a proto-oncogene that maintains cancer cell survival, which may also be related to DNA repair. c-Fos may impact the repair of DNA damage by regulating the expression of downstream proteins, including ATR, ERCC1, XPF, and others. Nonetheless, the underlying mechanisms necessitate further exploration.


Asunto(s)
Daño del ADN , Reparación del ADN , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-fos , Humanos , Reparación del ADN/genética , Daño del ADN/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Animales , Neoplasias/genética , Neoplasias/patología , Neoplasias/metabolismo
19.
ACS Biomater Sci Eng ; 10(2): 1062-1076, 2024 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-38245905

RESUMEN

Magnesium is a revolutionary biomaterial for orthopedic implants, owing to its eminent mechanical properties and biocompatibility. However, its uncontrolled degradation rate remains a severe challenge for its potential applications. In this study, we developed a self-healing micro arc oxidation (MAO) and dicalcium phosphate dihydrate (DCPD) double-passivated coating on a magnesium membrane (Mg-MAO/DCPD) and investigated its potential for bone-defect healing. The Mg-MAO/DCPD membrane possessed a feasible self-repairing ability and good cytocompatibility. In vitro degradation experiments showed that the Mg contents on the coating surface were 0.3, 3.8, 4.1, 6.1, and 7.9% when the degradation times were 0, 1, 2, 3, and 4 weeks, respectively, exhibiting available corrosion resistance. The slow and sustained release of Mg2+ during the degradation process activated extracellular matrix proteins for bone regeneration, accelerating osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The extract solutions of Mg-MAO/DCPD considerably promoted the activation of the Wnt and PI3K/AKT signaling pathways. Furthermore, the evaluation of the rat skull defect model manifested the outstanding bone-healing efficiency of the Mg-MAO/DCPD membrane. Taken together, the Mg-MAO/DCPD membrane demonstrates an optimized degradation rate and excellent bioactivity and is believed to have great application prospects in bone tissue engineering.


Asunto(s)
Fosfatos de Calcio , Materiales Biocompatibles Revestidos , Magnesio , Ratas , Humanos , Animales , Magnesio/farmacología , Materiales Biocompatibles Revestidos/farmacología , Osteogénesis , Fosfatidilinositol 3-Quinasas
20.
J Cell Physiol ; 239(4): e31187, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38219047

RESUMEN

Neural stem cells (NSCs) are pluripotent stem cells with the potential to differentiate into a variety of nerve cells. NSCs are susceptible to both intracellular and extracellular insults, thus causing DNA damage. Extracellular insults include ultraviolet, ionizing radiation, base analogs, modifiers, alkyl agents and others, while intracellular factors include Reactive oxygen species (ROS) radicals produced by mitochondria, mismatches that occur during DNA replication, deamination of bases, loss of bases, and more. When encountered with DNA damage, cells typically employ three coping strategies: DNA repair, damage tolerance, and apoptosis. NSCs, like many other stem cells, have the ability to divide, differentiate, and repair DNA damage to prevent mutations from being passed down to the next generation. However, when DNA damage accumulates over time, it will lead to a series of alterations in the metabolism of cells, which will cause cellular ageing. The ageing and exhaustion of neural stem cell will have serious effects on the body, such as neurodegenerative diseases. The purpose of this review is to examine the processes by which DNA damage leads to NSCs ageing and the mechanisms of DNA repair in NSCs.


Asunto(s)
Senescencia Celular , Daño del ADN , Células-Madre Neurales , Reparación del ADN , Células-Madre Neurales/fisiología , Neuronas/fisiología , Senescencia Celular/genética , Humanos
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