Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 247
Filtrar
1.
Biomaterials ; 313: 122765, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39244824

RESUMEN

Accurate and early detection of atherosclerosis (AS) is imperative for their effective treatment. However, fluorescence probes for efficient diagnosis of AS often encounter insufficient deep tissue penetration, which hinders the reliable assessment of plaque vulnerability. In this work, a reactive oxygen species (ROS) activated near-infrared (NIR) fluorescence and photoacoustic (FL/PA) dual model probe TPA-QO-B is developed by conjugating two chromophores (TPA-QI and O-OH) and ROS-specific group phenylboronic acid ester. The incorporation of ROS-specific group not only induces blue shift in absorbance, but also inhibits the ICT process of TPA-QO-OH, resulting an ignorable initial FL/PA signal. ROS triggers the convertion of TPA-QO-B to TPA-QO-OH, resulting in the concurrent amplification of FL/PA signal. The exceptional selectivity of TPA-QO-B towards ROS makes it effectively distinguish AS mice from the healthy. The NIR emission can achieve a tissue penetration imaging depth of 0.3 cm. Moreover, its PA775 signal possesses the capability to penetrate tissues up to a thickness of 0.8 cm, ensuring deep in vivo imaging of AS model mice in early stage. The ROS-triggered FL/PA dual signal amplification strategy improves the accuracy and addresses the deep tissue penetration problem simultaneously, providing a promising tool for in vivo tracking biomarkers in life science and preclinical applications.


Asunto(s)
Colorantes Fluorescentes , Técnicas Fotoacústicas , Placa Aterosclerótica , Especies Reactivas de Oxígeno , Animales , Especies Reactivas de Oxígeno/metabolismo , Técnicas Fotoacústicas/métodos , Placa Aterosclerótica/diagnóstico por imagen , Placa Aterosclerótica/metabolismo , Colorantes Fluorescentes/química , Ratones , Imagen Óptica/métodos , Ratones Endogámicos C57BL , Humanos , Masculino
2.
J Environ Manage ; 370: 122999, 2024 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-39490012

RESUMEN

Over the past three decades, numerous waterbird habitats have experienced considerable degradation as a result of the persistent deterioration of wetland ecosystems. Habitat suitability evaluation is a critical tool for restoring and conserving waterbird habitats. However, few studies have specifically examined the effects of temporal land cover changes on the suitability of migratory stopover habitats for waterbirds in transboundary regions. Consequently, this study leverages multi-source remote sensing imagery, applies an object-oriented classification approach for precise land cover extraction, and integrates GIS technology to identify key parameters that directly influence migratory waterbird resting sites. Through the establishment of a habitat suitability evaluation framework, this study aims to reveal the spatial and temporal patterns of habitat suitability in the Tumen River Estuary (TRE) from 1992 to 2021. Results reveal significant recent conversions of forest and grassland areas in the study area of China and North Korea to drylands, while marsh wetlands have been transformed into both drylands and paddy fields. Compared to 1992, the configuration of grasslands, marsh wetlands, and built-up land showed increased complexity in 2021. Notably, North Korea's landscape exhibited the most pronounced and loosely distributed fragmentation trends. The regions with the highest habitat suitability levels within the study area showed a clear declining trend, particularly in the most suitable zones across China and North Korea. This trend corresponds with an expansion of unsuitable areas, largely attributed to increased anthropogenic impacts as the primary driver of habitat suitability decline. The assessment of Moran's I indices highlights a strong spatial autocorrelation in the habitat suitability index across the TRE. The framework model developed in this study is well-suited to assist governmental entities in assessing and protecting habitats vital for endangered waterbird conservation.

3.
Angew Chem Int Ed Engl ; : e202416963, 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-39387351

RESUMEN

Photodynamic therapy (PDT) is a clinically approved therapeutic modality that has shown great potential for cancer treatment. However, there exist two major problems hindering PDT applications: the nonspecific phototoxicity requiring patients to stay in dark post-PDT, and the limited photodynamic efficiency. Herein, we report a photo-triggered porphyrin polyelectrolyte nanoassembling (photo-triggered PPN) strategy, in which porphyrin photosensitizer and photoswitchable energy accepter are assembled into polyelectrolyte micelles by a combined force of charge interaction and metal-ligand coordination. The polyelectrolyte-based PPN exhibits good biocompatibility, and bestows a unique "confining isolated" inner microenvironment for fully overcoming the π-π stacking of porphyrins with significant photodynamic efficiency (123-fold enhancement). Due to the high Förster resonance energy transfer (FRET) (91.5%) between porphyrin and photoswitch in closed-form, we could use light as a specific trigger to modulate photoswitch between closed- and open-form, and manipulate the 1O2 generation in three stages: pre-PDT (quenching 1O2 generation), during PDT (activating 1O2 generation), and post-PDT (silencing 1O2 generation). This de novo strategy has for the first time realized remotely manipulating and boosting 1O2 generation in PDT, well resolving the critical and general challenges of limited photodynamic efficiency and side effects from nonspecific phototoxicity.

4.
J Environ Manage ; 371: 123028, 2024 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-39476671

RESUMEN

Recycling packaging waste from residual waste can help alleviate resource pressure. However, its environmental and economic benefits remain uncertain, which hinders the widespread application of packaging waste recycling. This study assessed the greenhouse gas (GHG) emissions, environmental impacts, and external costs of a government-recommended technology for recycling packaging waste by applying Life Cycle Assessment (LCA) and ChintaxRCP model. The results showed that packaging waste recycling reduced GHG emissions by an average of 348.1 kg CO2-eq/t residual waste, and external costs by 376.7 €/t residual waste, due to the decrease in incineration. If all packaging waste in residual waste is recycled, over 60% of the total GHG emissions and about 80% of the external costs of residual waste management can be avoided. Moreover, sensitivity analysis indicated that the content of paper and plastic had a significant impact on the environmental impacts of residual waste management. This study demonstrates that recycling packaging waste instead of incineration can bring environmental and economic benefits in the long run. The study provides quantitative evidence to support policies for waste management and increases confidence in the utilization of low-value recyclables for the government.

5.
Chem Sci ; 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39246379

RESUMEN

The pancreatic tumor microenvironment presents multiple obstacles for polymer-based drug delivery systems, limiting tumor penetration and treatment efficacy. Here, we engineer a hyaluronidase/reactive oxygen species cascade-responsive size/charge bidirectional-tunable nanodelivery (btND, G/R@TKP/HA) for co-delivery of gemcitabine and KRAS siRNA, capable of navigating through tumor barriers and augmenting anticancer efficiency. When penetrating the tumor stroma barrier, the hyaluronic acid shell of the nanodelivery undergoes degradation by hyaluronidase in an extracellular matrix, triggering size tuning from large to small and charge tuning from negative to positive, thereby facilitating deeper penetration and cellular internalization. After endocytosis, the nanodelivery protonizes in the endo/lysosome, prompting rapid endo/lysosomal escape, effectively overcoming the lysosome barrier. Intracellular ROS further disrupt the nanodelivery, inducing its size tuning again from small to large and a positive charge decrease for high tumor retention and controlled drug release. The btND shows remarkable antitumor activity in pancreatic cancer mouse models, highlighting the efficacy of this approach in penetrating tumor barriers and enhancing anticancer outcomes.

6.
Chem Sci ; 15(31): 12431-12441, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39118631

RESUMEN

Singlet oxygen (1O2), as a fundamental hallmark in photodynamic therapy (PDT), enables ground-breaking clinical treatment in ablating tumors and killing germs. However, accurate in vivo monitoring of 1O2 remains a significant challenge in probe design, with primary difficulties arising from inherent photo-induced side reactions with poor selectivity. Herein, we report a generalizable zwitterionic strategy for ultra-stable near-infrared (NIR) chemiluminescent probes that ensure a highly specific [2 + 2] cycloaddition between fragile electron-rich enolether units and 1O2 in both cellular and dynamic in vivo domains. Innovatively, zwitterionic chemiluminescence (CL) probes undergo a conversion into an inert ketone excited state with an extremely short lifetime through conical intersection (CI), thereby affording sufficient photostability and suppressing undesired photoreactions. Remarkably, compared with the well-known commercial 1O2 probe SOSG, the zwitterionic probe QMI exhibited an ultra-high signal-to-noise ratio (SNR, over 40-fold). Of particular significance is that the zwitterionic CL probes demonstrate excellent selectivity, high sensitivity, and outstanding photostability, thereby making a breakthrough in real-time tracking of the FDA-approved 5-ALA-mediated in vivo PDT process in living mice. This innovative zwitterionic strategy paves a new pathway for high-performance NIR chemiluminescent probes and high-fidelity feedback on 1O2 for future biological and medical applications.

7.
Nat Commun ; 15(1): 6482, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39090140

RESUMEN

Nanosizing confers unique functions in materials such as graphene and quantum dots. Here, we present two nanoscale-covalent organic frameworks (nano-COFs) that exhibit exceptionally high activity for photocatalytic hydrogen production that results from their size and morphology. Compared to bulk analogues, the downsizing of COFs crystals using surfactants provides greatly improved water dispersibility and light-harvesting properties. One of these nano-COFs shows a hydrogen evolution rate of 392.0 mmol g-1 h-1 (33.3 µmol h-1), which is one of the highest mass-normalized rates reported for a COF or any other organic photocatalysts. A reverse concentration-dependent photocatalytic phenomenon is observed, whereby a higher photocatalytic activity is found at a lower catalyst concentration. These materials also show a molecule-like excitonic nature, as studied by photoluminescence and transient absorption spectroscopy, which is again a function of their nanoscale dimensions. This charts a new path to highly efficient organic photocatalysts for solar fuel production.

8.
J Am Chem Soc ; 146(29): 20107-20115, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38842422

RESUMEN

Photocatalytic covalent organic frameworks (COFs) are typically constructed with rigid aromatic linkers for crystallinity and extended π-conjugation. However, the essential hydrophobicity of the aromatic backbone can limit their performances in water-based photocatalytic reactions. Here, we for the first time report the synthesis of hydrophilic COFs with aliphatic linkers [tartaric acid dihydrazide (TAH) and butanedioic acid dihydrazide] that can function as efficient photocatalysts for H2O2 and H2 evolution. In these hydrophilic aliphatic linkers, the specific multiple hydrogen bonding networks not only enhance crystallization but also ensure an ideal compatibility of crystallinity, hydrophilicity, and light harvesting. The resulting aliphatic linker COFs adopt an unusual ABC stacking, giving rise to approximately 0.6 nm nanopores with an improved interaction with water guests. Remarkably, both aliphatic linker-based COFs show strong visible light absorption, along with a narrow optical band gap of ∼1.9 eV. The H2O2 evolution rate for TAH-COF reaches up to 6003 µmol h-1 g-1, in the absence of sacrificial agents, surpassing the performance of all previously reported COF-based photocatalysts. Theoretical calculations reveal that the TAH linker can enhance the indirect two-electron oxygen reduction reaction for H2O2 production by improving the O2 adsorption and stabilizing the *OOH intermediate. This study opens a new avenue for constructing semiconducting COFs using nonaromatic linkers.

9.
J Am Chem Soc ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38843049

RESUMEN

The development of a catalytic method for stereogenic carbon center formation holds immense significance in organic synthesis. Transition-metal-catalyzed cross-coupling reaction has been regarded as a straightforward and efficient tool for stereoselectively forging C-C bond. Nevertheless, the creation of acyclic all-carbon quaternary-containing vicinal stereocenters remains notoriously challenging within the domain of cross-coupling chemistry despite their prominence in various bioactive small molecules. Herein, we describe a palladium-catalyzed asymmetric multicomponent cross-coupling of trisubstituted alkene with aryl diazonium salts and arylboronic acids to realize the formation of tertiary-quaternary carbon centers with high regio-, distereo-, and enantioselectivity. Specifically, the precise manipulation of the stereoconfiguration of trisubstituted alkenes enables the divergent stereoselective cross-coupling reaction, thus allowing for the facile construction of all four enantiomers. Harnessing the ligand-swap strategy involving a chiral bisoxazoline and an achiral fumarate individually accelerates the enantioselective migratory insertion and reductive elimination step in the cross-coupling process, as supported by density functional theory (DFT) calculations, thus obviating the requirement for a neighboring directing group within the internal olefin skeleton.

10.
Med Res Rev ; 44(6): 2472-2509, 2024 11.
Artículo en Inglés | MEDLINE | ID: mdl-38711187

RESUMEN

Previously, lysosomes were primarily referred to as the digestive organelles and recycling centers within cells. Recent discoveries have expanded the lysosomal functional scope and revealed their critical roles in nutrient sensing, epigenetic regulation, plasma membrane repair, lipid transport, ion homeostasis, and cellular stress response. Lysosomal dysfunction is also found to be associated with aging and several diseases. Therefore, function of macroautophagy, a lysosome-dependent intracellular degradation system, has been identified as one of the updated twelve hallmarks of aging. In this review, we begin by introducing the concept of lysosomal quality control (LQC), which is a cellular machinery that maintains the number, morphology, and function of lysosomes through different processes such as lysosomal biogenesis, reformation, fission, fusion, turnover, lysophagy, exocytosis, and membrane permeabilization and repair. Next, we summarize the results from studies reporting the association between LQC dysregulation and aging/various disorders. Subsequently, we explore the emerging therapeutic strategies that target distinct aspects of LQC for treating diseases and combatting aging. Lastly, we underscore the existing knowledge gap and propose potential avenues for future research.


Asunto(s)
Envejecimiento , Lisosomas , Humanos , Lisosomas/metabolismo , Envejecimiento/metabolismo , Animales , Enfermedad , Autofagia
11.
Biofabrication ; 16(3)2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38697099

RESUMEN

Rotator cuff tear is one of the most common musculoskeletal disorders, which often results in recurrent shoulder pain and limited movement. Enthesis is a structurally complex and functionally critical interface connecting tendon and bone that plays an essential role in maintaining integrity of the shoulder joint. Despite the availability of advanced surgical procedures for rotator cuff repair, there is a high rate of failure following surgery due to suboptimal enthesis healing and regeneration. Novel strategies based on tissue engineering are gaining popularity in improving tendon-bone interface (TBI) regeneration. Through incorporating physical and biochemical cues into scaffold design which mimics the structure and composition of native enthesis is advantageous to guide specific differentiation of seeding cells and facilitate the formation of functional tissues. In this review, we summarize the current state of research in enthesis tissue engineering highlighting the development and application of biomimetic scaffolds that replicate the gradient TBI. We also discuss the latest techniques for fabricating potential translatable scaffolds such as 3D bioprinting and microfluidic device. While preclinical studies have demonstrated encouraging results of biomimetic gradient scaffolds, the translation of these findings into clinical applications necessitates a comprehensive understanding of their safety and long-term efficacy.


Asunto(s)
Manguito de los Rotadores , Ingeniería de Tejidos , Andamios del Tejido , Humanos , Andamios del Tejido/química , Manguito de los Rotadores/cirugía , Animales , Materiales Biomiméticos/química , Regeneración , Biomimética , Lesiones del Manguito de los Rotadores/cirugía , Impresión Tridimensional
12.
Adv Healthc Mater ; : e2401347, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38819639

RESUMEN

Identifying infected stones is crucial due to their rapid growth and high recurrence rate. Here, the calcium-magnesium dual-responsive aggregation-induced emission (AIE)-active probe TCM-5COOH (Tricyano-methlene-pyridine-5COOH), distinctively engineered to distinguish high-threat infection calculi from metabolic stones, is presented. Upon incorporation of flexible alkyl carboxyl group, TCM-5COOH featuring five carboxyl moieties demonstrates excellent water solubility and enhanced penetration into porous infectious stones. The robust chelation of TCM-5COOH with stone surface-abundant Ca2+ and Mg2+ inhibits vibrational relaxation, thus triggering intense AIE signals. Remarkably, the resulting complex exhibits high insolubility, effectively anchoring within the porous structure of the infection calculi and offering prolonged illumination. Jobs' plot method reveals similar response characteristics for Ca2+ and Mg2+, with a 1:2 coordination number for both ions. Isothermal titration calorimetry (ITC) results demonstrate higher enthalpy change (ΔH) and lower entropy change (ΔS) for the reaction, indicating enhanced selectivity compared to TCM-4COOH lacking the alkyl carboxyl group. Synchrotron X-ray absorption fine spectroscopy (XAFS) validates TCM-5COOH's interaction with Ca2+ and Mg2+ at the microlevel. This dual-responsive probe excels in identifying infectious and metabolic calculi, compatible with endoscopic modalities and laser excitation, thereby prompting clinical visualization and diagnostic assessment.

13.
Acta Biomater ; 179: 340-353, 2024 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-38556136

RESUMEN

Cellular senescence is a permanent state of cell cycle arrest characterized by increased activity of senescence associated ß-galactosidase (SA-ß-gal). Notably, cancer cells have been also observed to exhibit the senescence response and are being considered for sequential treatment with pro-senescence therapy followed by senolytic therapy. However, there is currently no effective agent targeting ß-galactosidase (ß-Gal) for imaging cellular senescence and monitoring senolysis in cancer therapy. Aggregation-induced emission luminogen (AIEgen) demonstrates strong fluorescence, good photostability, and biocompatibility, making it a potential candidate for imaging cellular senescence and monitoring senolysis in cancer therapy when endowed with ß-Gal-responsive capabilities. In this study, we introduced a ß-Gal-activated AIEgen named QM-ß-gal for cellular senescence imaging and senolysis monitoring in cancer therapy. QM-ß-gal exhibited good amphiphilic properties and formed aggregates that emitted a fluorescence signal upon ß-Gal activation. It showed high specificity towards the activity of ß-Gal in lysosomes and successfully visualized DOX-induced senescent cancer cells with intense fluorescence both in vitro and in vivo. Encouragingly, QM-ß-gal could image senescent cancer cells in vivo for over 14 days with excellent biocompatibility. Moreover, it allowed for the monitoring of senescent cancer cell clearance during senolytic therapy with ABT263. This investigation indicated the potential of the ß-Gal-activated AIEgen, QM-ß-gal, as an in vivo approach for imaging cellular senescence and monitoring senolysis in cancer therapy via highly specific and long-term fluorescence imaging. STATEMENT OF SIGNIFICANCE: This work reported a ß-galactosidase-activated AIEgen called QM-ß-gal, which effectively imaged DOX-induced senescent cancer cells both in vitro and in vivo. QM-ß-gal specifically targeted the increased expression and activity of ß-galactosidase in senescent cancer cells, localized within lysosomes. It was cleared rapidly before activation but maintained stability after activation in the DOX-induced senescent tumor. The AIEgen exhibited a remarkable long-term imaging capability for senescent cancer cells, lasting over 14 days and enabled monitoring of senescent cancer cell clearance through ABT263-induced apoptosis. This approach held promise for researchers seeking to achieve prolonged imaging of senescent cells in vivo.


Asunto(s)
Senescencia Celular , beta-Galactosidasa , Senescencia Celular/efectos de los fármacos , beta-Galactosidasa/metabolismo , Humanos , Animales , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Neoplasias/tratamiento farmacológico , Línea Celular Tumoral , Ratones Desnudos , Ratones , Doxorrubicina/farmacología , Doxorrubicina/química , Imagen Óptica/métodos
14.
BMJ Open ; 14(3): e077242, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553073

RESUMEN

INTRODUCTION: Anterior cruciate ligament (ACL) rupture can be treated surgically or non-surgically, with several surgical interventions available at present. However, the comparatively effective surgical intervention with relatively fewer side effects remains unknown. This study aims to fill in this gap by conducting a Bayesian network meta-analysis (NMA) and provide a theoretical basis for the clinical application. METHOD AND ANALYSIS: We will perform a Bayesian NMA and will include randomised controlled trials (RCTs) published in English or Chinese that compare surgical intervention (ie, standard ACL reconstruction, ACL remnant-preserving reconstruction and ACL repair with suture augmentation to conservative therapy or studies that compare one surgical intervention to another for the symptom relief and function recovery of patients with ACL rupture. Primary outcome will be the proportion of patients with symptomatic and functional improvement measured by the Knee Injury and Osteoarthritis Outcome Score before and 6 months after treatment, with scores ranging from 0 (worst) to 100 (best). Secondary outcomes will be knee-specific quality of life (ACL QoL), return to activity and level of sport participation (Tegner or modified Tegner score), health-related QoL (EuroQol Group 5-Dimension 5-Level, EQ-5D-5L), resource use, intervention-related complications and patient satisfaction. We have developed search strategies for PubMed, Embase, the Cochrane Library and Web of Science, retrieving RCTs that meet the inclusion criteria from database inception to 1 December 2023. The methodological quality of the included RCTs will be assessed based on the Cochrane risk of bias table. The relative ranking probability of the best intervention will be estimated using the surface under the cumulative ranking curve. The Bayesian NMA will be conducted by using WinBUGS V.1.4.3. The Grading of Recommendations Assessment, Development and Evaluation approach will be applied to determine our confidence in an overall treatment ranking from the NMA. ETHICS AND DISSEMINATION: Ethical approval for this study is not required because no private or confidential patient data will be used in this study. Findings of this study would be disseminated through the publication in a peer-reviewed medical journal. PROSPERO REGISTRATION NUMBER: CRD42023437115.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Teorema de Bayes , Metaanálisis en Red , Humanos , Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Calidad de Vida , Proyectos de Investigación , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento , Revisiones Sistemáticas como Asunto , Recuperación de la Función
15.
Angew Chem Int Ed Engl ; 63(16): e202401260, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38372399

RESUMEN

Formamidinium lead iodide (FAPbI3) represents an optimal absorber material in perovskite solar cells (PSCs), while the application of FAPbI3 in inverted-structured PSCs has yet to be successful, mainly owing to its inferior film-forming on hydrophobic or defective hole-transporting substrates. Herein, we report a substantial improvement of FAPbI3-based inverted PSCs, which is realized by a multifunctional amphiphilic molecular hole-transporter, (2-(4-(10H-phenothiazin-10-yl)phenyl)-1-cyanovinyl)phosphonic acid (PTZ-CPA). The phenothiazine (PTZ) based PTZ-CPA, carrying a cyanovinyl phosphonic acid (CPA) group, forms a superwetting hole-selective underlayer that enables facile deposition of high-quality FAPbI3 thin films. Compared to a previously established carbazole-based hole-selective material (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), the crystallinity of FAPbI3 is enhanced and the electronic defects are passivated by the PTZ-CPA more effectively, resulting in remarkable increases in photoluminescence quantum yield (four-fold) and Shockley-Read-Hall lifetime (eight-fold). Moreover, the PTZ-CPA shows a larger molecular dipole moment and improved energy level alignment with FAPbI3, benefiting the interfacial hole-collection. Consequently, FAPbI3-based inverted PSCs achieve an unprecedented efficiency of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. The PTZ-CPA based device shows commendable long-term stability, maintaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2000 hours.

16.
Sci Rep ; 14(1): 4203, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38378813

RESUMEN

Seasonal erosion flooding events present a significant challenge for effective disaster monitoring and land degradation studies. This research addresses this challenge by harnessing the combined capabilities of time-series Landsat and MODIS images to achieve high spatiotemporal-resolution mapping of flooding during such events. The study underscores the critical importance of precise flood monitoring for disaster mitigation and informed land management. To overcome the limitations posed by the trade-off between spatial and temporal resolution in current satellite sensors, we emplyedand theflexible spatiotemporal data fusion (FSDAF) methods to produce synthetic flood images with enhanced spatiotemporal resolutions for mapping by using MODIS and Landsat data from August 29 to September 3, 2016. A comparison was made between flood maps from several post-disaster forecasts based on ground-obtained time-series images of the Tumen River flood in China. According to the FSDAF approach, the input Landsat image of March 25, 2016, and the fused results had a root mean square error (RMSE) of 0.0301, average difference of 0.001, r of 0.941, and structure similarity indexof 0.939, indicating that temporal variation data had been effectively incorporated into a forecast on August 16, 2016. Results also indicated that the FSDAF forecast values are lower than those from the actual Landsat image. The results of the study also showed that the generated images could be effectively used for flood mapping. By using our newly developed simulation model, we were able to produce a comprehensive map of the inundated areas during the event from August 29 to September 3, 2016. This shows that FSDAF holds great potential for flood prediction and study and has the potential to benefit further disaster-related land degradation by combining multi-source images to provide high temporal and spatial resolution remote sensing information.

17.
Ann Biomed Eng ; 52(2): 141-152, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37731091

RESUMEN

Tendon and ligament injuries account for a substantial proportion of disorders in the musculoskeletal system. While non-operative and operative treatment strategies have advanced, the restoration of native tendon and ligament structures after injury is still challenging due to its innate limited regenerative ability. Cell sheet technology is an innovative tool for tissue fabrication and cell transplantation in regenerative medicine. In this review, we first summarize different harvesting procedures and advantages of cell sheet technology, which preserves intact cell-to-cell connections and extracellular matrix. We then describe the recent progress of cell sheet technology from preclinical studies, focusing on the application of stem cell-derived sheets in treating tendon and ligament injuries, as well as highlighting its effects on mitigating inflammation and promoting tendon/graft-bone interface healing. Finally, we discuss several prerequisites for future clinical translation including the selection of appropriate cell source, optimization of preparation process, establishment of suitable animal model, and the fabrication of vascularized complex tissue. We believe this review could potentially provoke new ideas and drive the development of more functional biomimetic tissues using cell sheet technology to meet the needs of clinical patients.


Asunto(s)
Tendones , Ingeniería de Tejidos , Animales , Humanos , Ingeniería de Tejidos/métodos , Medicina Regenerativa/métodos , Células Madre , Ligamentos
18.
Water Res ; 249: 121005, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38096727

RESUMEN

The forest nitrate cycle is a crucial part of the watershed nitrate load but has received limited attention compared to that of agricultural and residential land. Here, we analyzed the status and sources of riverine nitrate fluxes and identified the characteristics and contribution of forest nitrate loss to the riverine system in a mid-high latitude forested watershed using monthly field sampling and a modified Soil and Water Assessment Tool (SWAT) with enhanced forest nutrient cycle representation. The results indicate that nitrate losses in the headwater stream and downstream exhibit different seasonal characteristics. The nitrate losses in the headwater stream show a bimodal pattern due to lower temperatures and snowmelt runoff. Redundancy analysis (RDA) revealed that, unlike nitrogen (N) fertilizer-induced nitrate loss in the rainy season, forest loss has a positive effect on headwater stream nitrate concentration during the snowmelt season. The modified SWAT was then utilized to simulate nitrate losses in forest lands. The forest nitrate export per unit area of the headwater stream (1.58 ± 1.78 kg/ha/yr) was observed to be higher than that of the downstream (0.67 ± 0.74 kg/ha/yr) due to high snowmelt and mineralization of active organic N. At watershed scale, forest lands contributed 8.18 ± 3.94 % of the total nitrate losses to the water system in the headwater watersheds during the snowmelt season, representing the highest level within the entire basin. A comparison with forest streams in similar low-temperature conditions worldwide revealed that increasing nitrate loss occurred after extreme cold weather or soil freezing events, with an average increment of 6.32 kg/ha/yr. Therefore, forest nitrate losses should be better characterized and included in future watershed N budgets in low-temperature regions, which might help to reduce the N budget uncertainty and improve watershed management.


Asunto(s)
Monitoreo del Ambiente , Nitratos , Nitratos/análisis , Bosques , Compuestos Orgánicos , Suelo , Agua/análisis
19.
Arthroplast Today ; 24: 101160, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37927301

RESUMEN

Background: Extensive bone loss on femur and acetabulum posed a big challenge to orthopedists in total hip revision surgeries. Impaction bone grafting (IBG) as a valuable bone preservation technique could effectively address this problem. Either IBG revision on the femoral or acetabular side was well studied, while its use on both sides in one operation was not. The aim of this study is to present the outcomes of IBG on both femoral and acetabular sides at first-time hip revision. Methods: We retrospectively reviewed 8 patients (mean follow-up of 5.8 years) undergoing first-time revision with IBG on both acetabular and femoral sides at our institution. The Paprosky classification system was used to classify bone defects. Freeze-dried allografts and cemented prostheses were used in all patients. Postoperative complications and rerevision rates were reported. Results: Five patients presented a Paprosky type IIC acetabular defect, 3 with a type IIIB, IIIA, and IIC defect, respectively. Three patients presented with a type IV femoral defect, 3 with a type IIIB defect, and 2 with a type II defect. Two patients developed complications, while one had an intraoperative femoral fracture and one had delayed wound healing. At the latest follow-up, no patient had rerevisions or operations related to the prosthesis. Conclusions: IBG in combination with cemented prosthesis is a profitable biological reconstruction revision technique that could provide satisfying midterm outcomes. We first propose the use of blood clots mixed with bone grafts for potential bone incorporation enhancement, while its specific effects need to be verified in further studies.

20.
Angew Chem Int Ed Engl ; 62(52): e202316647, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-37968887

RESUMEN

The development of ultra-long room-temperature phosphorescence (UL-RTP) in processable amorphous organic materials is highly desirable for applications in flexible displays, anti-counterfeiting, and bio-imaging. However, achieving efficient UL-RTP from amorphous materials remains a challenging task, especially with activation by visible light and a bright afterglow. Here we report a general and rational molecular-design strategy to enable efficient visible-light-excited UL-RTP by multi-esterification of a rigid large-plane phosphorescence core. Notably, multi-esterification minimizes the aggregation-induced quenching and accomplishes a 'four birds with one stone' possibility in the generation and radiation process of UL-RTP: i) shifting the excitation from ultraviolet light to blue-light through enhancing the transition dipole moment of low-lying singlet-states, ii) facilitating the intersystem crossing process through the incorporation of lone-pair electrons, iii) boosting the decay process of long-lived triplet excitons resulting from a significantly increased transition dipole moment, and iv) reducing the intrinsic triplet nonradiative decay by substitution of high-frequency vibrating hydrogen atoms. All these factors synergistically contribute to the most efficient and stable visible-light-stimulated UL-RTP (lifetime up to 2.01 s and efficiency up to 35.4 % upon excitation at 450 nm) in flexible films using multi-esterified coronene, which allows high-tech applications in single-component time-delayed white light-emitting diodes and information technology based on flashlight-activated afterglow encryption.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...