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1.
Int J Nanomedicine ; 19: 8709-8727, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39220191

RESUMO

Background: The formation of adhesion after tendon injury represents a major obstacle to tendon repair, and currently there is no effective anti-adhesion method in clinical practice. Oxidative stress, inflammation, and fibrosis can occur in tendon injury and these factors can lead to tendon adhesion. Antioxidant carbon dots and ursolic acid (UA) both possess antioxidant and anti-inflammatory properties. In this experiment, we have for the first time created RCDs/UA@Lipo-HAMA using red fluorescent carbon dots and UA co-encapsulated liposomes composite hyaluronic acid methacryloyl hydrogel. We found that RCDs/UA@Lipo-HAMA could better attenuate adhesion formation and enhance tendon healing in tendon injury. Materials and Methods: RCDs/UA@Lipo-HAMA were prepared and characterized. In vitro experiments on cellular oxidative stress and fibrosis were performed. Reactive oxygen species (ROS), and immunofluorescent staining of collagens type I (COL I), collagens type III (COL III), and α-smooth muscle actin (α-SMA) were used to evaluate anti-oxidative and anti-fibrotic abilities. In vivo models of Achilles tendon injury repair (ATI) and flexor digitorum profundus tendon injury repair (FDPI) were established. The major organs and blood biochemical indicators of rats were tested to determine the toxicity of RCDs/UA@Lipo-HAMA. Biomechanical testing, motor function analysis, immunofluorescence, and immunohistochemical staining were performed to assess the tendon adhesion and repair after tendon injury. Results: In vitro, the RCDs/UA@Lipo group scavenged excessive ROS, stabilized the mitochondrial membrane potential (ΔΨm), and reduced the expression of COL I, COL III, and α-SMA. In vivo, assessment results showed that the RCDs/UA@Lipo-HAMA group improved collagen arrangement and biomechanical properties, reduced tendon adhesion, and promoted motor function after tendon injury. Additionally, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the RCDs/UA@Lipo-HAMA group increased; the levels of cluster of differentiation 68 (CD68), inducible Nitric Oxide Synthase (iNOS), COL III, α-SMA, Vimentin, and matrix metallopeptidase 2 (MMP2) decreased. Conclusion: In this study, the RCDs/UA@Lipo-HAMA alleviated tendon adhesion formation and enhanced tendon healing by attenuating oxidative stress, inflammation, and fibrosis. This study provided a novel therapeutic approach for the clinical treatment of tendon injury.


Assuntos
Antioxidantes , Carbono , Hidrogéis , Lipossomos , Ratos Sprague-Dawley , Traumatismos dos Tendões , Triterpenos , Ácido Ursólico , Animais , Triterpenos/farmacologia , Triterpenos/química , Antioxidantes/farmacologia , Antioxidantes/química , Lipossomos/química , Traumatismos dos Tendões/tratamento farmacológico , Aderências Teciduais/tratamento farmacológico , Carbono/química , Carbono/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Ratos , Estresse Oxidativo/efeitos dos fármacos , Masculino , Cicatrização/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Pontos Quânticos/química , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Tendão do Calcâneo/efeitos dos fármacos , Tendão do Calcâneo/lesões
2.
PNAS Nexus ; 3(9): pgae389, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39295949

RESUMO

Understanding processes driving air-sea gas transfer and being able to model both its mean and variability are critical for studies of climate and carbon cycle. The air-sea gas transfer velocity (K 660) is almost universally parameterized as a function of wind speed in large scale models-an oversimplification that buries the mechanisms controlling K 660 and neglects much natural variability. Sea state has long been speculated to affect gas transfer, but consistent relationships from in situ observations have been elusive. Here, applying a machine learning technique to an updated compilation of shipboard direct observations of the CO2 transfer velocity (K CO2,660), we show that the inclusion of significant wave height improves the model simulation of K CO2,660, while parameters such as wave age, wave steepness, and swell-wind directional difference have little influence on K CO2,660. Wind history is found to be important, as in high seas K CO2,660 during periods of falling winds exceed periods of rising winds by ∼20% in the mean. This hysteresis in K CO2,660 is consistent with the development of waves and increase in whitecap coverage as the seas mature. A similar hysteresis is absent from the transfer of a more soluble gas, confirming that the sea state dependence in K CO2,660 is primarily due to bubble-mediated gas transfer upon wave breaking. We propose a new parameterization of K CO2,660 as a function of wind stress and significant wave height, which resemble observed K CO2,660 both in the mean and on short timescales.

3.
Sci Adv ; 10(30): eadn5781, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39047102

RESUMO

The Southern Ocean is the primary region for the uptake of anthropogenic carbon dioxide (CO2) and is, therefore, crucial for Earth's climate. However, the Southern Ocean CO2 flux estimates reveal substantial uncertainties and lack direct validation. Using seven independent and directly measured air-sea CO2 flux datasets, we identify a 25% stronger CO2 uptake in the Southern Ocean than shipboard dataset-based flux estimates. Accounting for upper ocean temperature gradients and insufficient temporal resolution of flux products can bridge this flux gap. The gas transfer velocity parameterization is not the main reason for the flux disagreement. The profiling float data-based flux products and biogeochemistry models considerably underestimate the observed CO2 uptake, which may be due to the lack of representation of small-scale high-flux events. Our study suggests that the Southern Ocean may take up more CO2 than previously recognized, and that temperature corrections should be considered, and a higher resolution is needed in data-based bulk flux estimates.

4.
Acta Biomater ; 184: 171-185, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38871202

RESUMO

Avoiding ischemic necrosis after flap transplantation remains a significant clinical challenge. Developing an effective pretreatment method to promote flap survival postoperatively is crucial. Cobalt chloride (CoCl2) can increase cell tolerance to ischemia and hypoxia condition by stimulating hypoxia-inducible factor-1 (HIF-1) expression. However, the considerable toxic effects severely limit the clinical application of CoCl2. In this study, cobalt-based metal-organic frameworks (Co-MOF) encapsulated in a microneedle patch (Co-MOF@MN) was developed to facilitate the transdermal sustained release of Co2+ for rapid, minimally invasive rapid pretreatment of flap transplantation. The MN patch was composed of a fully methanol-based two-component cross-linked polymer formula, with a pyramid structure and high mechanical strength, which satisfied the purpose of penetrating the skin stratum corneum of rat back to achieve subcutaneous vascular area administration. Benefiting from the water-triggered disintegration of Co-MOF and the transdermal delivery via the MN patch, preoperative damage and side effects were effectively mitigated. Moreover, in both the oxygen-glucose deprivation/recovery (OGD/R) cell model and the rat dorsal perforator flap model, Co-MOF@MN activated the HIF-1α pathway and its associated downstream proteins, which reduced reperfusion oxidative damage, improved blood supply in choke areas, and increased flap survival rates post-transplantation. This preprotection strategy, combining MOF nanoparticles and the MN patch, meets the clinical demands for trauma minimization and uniform administration in flap transplantation. STATEMENT OF SIGNIFICANCE: Cobalt chloride (CoCl2) can stimulate the expression of hypoxia-inducible factor (HIF-1) and improve the tolerance of cells to ischemia and hypoxia conditions. However, the toxicity and narrow therapeutic window of CoCl2 severely limit its clinical application. Herein, we explored the role of Co-MOF as a biocompatible nanocage for sustained release of Co2+, showing the protective effect on vascular endothelial cells in the stress model of oxygen-glucose deprivation. To fit the clinical needs of minimal trauma in flap transplantation, a Co-MOF@MN system was developed to achieve local transdermal delivery at the choke area, significantly improving blood supply opening and flap survival rate. This strategy of two-step delivery of Co2+ realized the enhancement of biological functions while ensuring the biosafety.


Assuntos
Cobalto , Estruturas Metalorgânicas , Retalhos Cirúrgicos , Animais , Humanos , Masculino , Ratos , Cobalto/química , Cobalto/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isquemia/patologia , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Necrose , Ratos Sprague-Dawley , Adesivo Transdérmico
5.
Opt Express ; 32(6): 8572-8579, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571113

RESUMO

In this paper, we propose a system for enhancing the RF output power of the photodetector, especially the power of fundamental tune and second-order harmonic, by feeding back part of the RF signal through an electrical feedback circuit. As a result of bias modulation and opto-electric mixing, the RF output power can be effectively enhanced. The structure of uni-traveling carrier photodetector (UTC-PD) is employed in this work. With the RF enhancement system, the power of fundamental tune and second-order harmonic improve by 6.4 dB and 9.9 dB respectively, under the condition of 26 dBm input optical power, 3 V bias voltage, and 14 GHz input optical signal. Further, it was observed that third-order harmonic appeared under the influence of this system.

6.
J Nanobiotechnology ; 22(1): 100, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38462597

RESUMO

BACKGROUND: Despite the higher sensitivity of melanoma towards ferroptosis and photodynamic therapy (PDT), the lack of efficient ferroptosis inducers and the poor solubility of photosensitizers restrict their synergistic strategies. With unique advantages, carbon dots (CDs) are expected to serve as innovative building blocks for combination therapy of cancers. RESULTS: Herein, an ferroptosis/PDT integrated nanoplatform for melanoma therapy is constructed based on chlorin e6-modified Fe ions-doped carbon dots (Fe-CDs@Ce6). As a novel type of iron-carbon hybrid nanoparticles, the as-prepared Fe-CDs can selectively activate ferroptosis, prevent angiogenesis and inhibit the migration of mouse skin melanoma cells (B16), but have no toxicity to normal cells. The nano-conjugated structures facilitate not only the aqueous dispersibility of Ce6, but also the self-accumulation ability of Fe-CDs@Ce6 within melanoma area without requiring extra targets. Moreover, the therapeutic effects of Fe-CDs@Ce6 are synergistically enhanced due to the increased GSH depletion by PDT and the elevated singlet oxygen (1O2) production efficiency by Fe-CDs. When combined with laser irradiation, the tumor growth can be significantly suppressed by Fe-CDs@Ce6 through cyclic administration. The T2-weighted magnetic resonance imaging (MRI) capability of Fe-CDs@Ce6 also reveals their potentials for cancer diagnosis and navigation therapy. CONCLUSIONS: Our findings indicate the multifunctionality of Fe-CDs@Ce6 in effectively combining ferroptosis/PDT therapy, tumor targeting and MRI imaging, which enables Fe-CDs@Ce6 to become promising biocompatible nanoplatform for the treatment of melanoma.


Assuntos
Ferroptose , Melanoma , Nanopartículas , Fotoquimioterapia , Camundongos , Animais , Fotoquimioterapia/métodos , Melanoma/tratamento farmacológico , Carbono/farmacologia , Carbono/química , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/química , Imageamento por Ressonância Magnética , Nanopartículas/química
7.
J Nanobiotechnology ; 21(1): 431, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978538

RESUMO

BACKGROUND: Tumor treatment still remains a clinical challenge, requiring the development of biocompatible and efficient anti-tumor nanodrugs. Carbon dots (CDs) has become promising nanomedicines for cancer therapy due to its low cytotoxicity and easy customization. RESULTS: Herein, we introduced a novel type of "green" nanodrug for multi-level cancer therapy utilizing Fe-doped carbon dots (Fe-CDs) derived from iron nutrient supplement. With no requirement for target moieties or external stimuli, the sole intravenous administration of Fe-CDs demonstrated unexpected anti-tumor activity, completely suppressing tumor growth in mice. Continuous administration of Fe-CDs for several weeks showed no toxic effects in vivo, highlighting its exceptional biocompatibility. The as-synthesized Fe-CDs could selectively induce tumor cells apoptosis by BAX/Caspase 9/Caspase 3/PARP signal pathways and activate antitumoral macrophages by inhibiting the IL-10/Arg-1 axis, contributing to its significant tumor immunotherapy effect. Additionally, the epithelial-mesenchymal transition (EMT) process was inhibited under the treatment of Fe-CDs by MAPK/Snail pathways, indicating the capacity of Fe-CDs to inhibit tumor recurrence and metastasis. CONCLUSIONS: A three-level tumor treatment strategy from direct killing to activating immunity to inhibiting metastasis was achieved based on "green" Fe-CDs. Our findings reveal the broad clinical potential of Fe-CDs as a novel candidate for anti-tumor nanodrugs and nanoplatform.


Assuntos
Neoplasias , Pontos Quânticos , Animais , Camundongos , Carbono/farmacologia , Neoplasias/tratamento farmacológico
8.
Proc Natl Acad Sci U S A ; 120(25): e2218127120, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37314935

RESUMO

Reduced nitrogen (N) is central to global biogeochemistry, yet there are large uncertainties surrounding its sources and rate of cycling. Here, we present observations of gas-phase urea (CO(NH2)2) in the atmosphere from airborne high-resolution mass spectrometer measurements over the North Atlantic Ocean. We show that urea is ubiquitous in the lower troposphere in the summer, autumn, and winter but was not detected in the spring. The observations suggest that the ocean is the primary emission source, but further studies are required to understand the responsible mechanisms. Urea is also observed aloft due to long-range transport of biomass-burning plumes. These observations alongside global model simulations point to urea being an important, and currently unaccounted for, component of reduced-N to the remote marine atmosphere. Airborne transfer of urea between nutrient-rich and -poor parts of the ocean can occur readily and could impact ecosystems and oceanic uptake of carbon dioxide, with potentially important climate implications.

9.
Front Neurol ; 14: 1184246, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37377855

RESUMO

The nerve trunk healing process of a transected peripheral nerve trunk is composed of angiogenesis, nerve fiber regeneration, and scarring. Nerve trunk healing and neuroma formation probably share identical molecular mediators and similar regulations. At the nerve transection site, angiogenesis is sufficient and necessary for nerve fiber regeneration. Angiogenesis and nerve fiber regeneration reveal a positive correlation in the early time. Scarring and nerve fiber regeneration show a negative correlation in the late phase. We hypothesize that anti-angiogenesis suppresses neuromas. Subsequently, we provide potential protocols to test our hypothesis. Finally, we recommend employing anti-angiogenic small-molecule protein kinase inhibitors to investigate nerve transection injuries.

10.
Adv Healthc Mater ; 12(26): e2300890, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37279380

RESUMO

Periodontitis is a type of chronic inflammatory oral disease characterized by the destruction of periodontal connective tissue and progressive alveolar bone resorption. As oxidative stress is the key cause of periodontitis in the early periodontal microenvironment, antioxidative therapy has been considered a viable treatment for periodontitis. However, more stable and effective reactive oxygen species (ROS)-scavenging nanomedicines are still highly needed due to the instability of traditional antioxidants. Herein, a new type of N-acetyl-l-cysteine (NAC)-derived red fluorescent carbonized polymer dots (CPDs) has been synthesized with excellent biocompatibility, which can serve as an extracellular antioxidant to scavenge ROS effectively. Moreover, NAC-CPDs can promote osteogenic differentiation in human periodontal ligament cells (hPDLCs) under H2 O2 stimulation. In addition, NAC-CPDs are capable of targeted accumulation in alveolar bone in vivo, reducing the level of alveolar bone resorption in periodontitis mice, as well as performing fluorescence imaging in vitro and in vivo. In terms of mechanism, NAC-CPDs may regulate redox homeostasis and promote bone formation in the periodontitis microenvironment by modulating the kelch-like ECH-associated protein l (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. This study provides a new strategy for the application of CPDs theranostic nanoplatform for periodontitis.


Assuntos
Reabsorção Óssea , Periodontite , Camundongos , Humanos , Animais , Espécies Reativas de Oxigênio/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Acetilcisteína/farmacologia , Acetilcisteína/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Osteogênese , Antioxidantes/metabolismo , Estresse Oxidativo , Periodontite/tratamento farmacológico , Periodontite/metabolismo , Homeostase
12.
Biomater Sci ; 11(11): 3998-4008, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37128751

RESUMO

Ischemic stroke (IS) is a leading cause of death in the world, and there is still a lack of effective treatments. Ginkgolide B (GB) can antagonize the platelet activating factor receptor and has shown a significant curative effect on cerebral ischemia. However, GB and other drugs for IS have shown poor clinical efficacy due to their inability to cross the blood-brain barrier (BBB). Herein, red fluorescent carbonized polymer dots (CPDs) were developed as biocompatible nanocarriers to deliver GB to the brain tissue. Both in vivo and in vitro experiments verified the ability of GB-CPDs to penetrate the BBB, and GB-CPDs remained in the brain significantly longer than unmodified CPDs. In a rat model of middle cerebral artery occlusion (MCAO), circulatory administration of GB-CPDs effectively reduced cerebral infarct size and neuronal apoptosis, with a significantly better therapeutic effect compared to GB. This study provided a novel GB-based nanodrug that could target the brain with improved efficacy, showing great application potential in central nervous system diseases.


Assuntos
Isquemia Encefálica , Traumatismo por Reperfusão , Ratos , Animais , Encéfalo , Ginkgolídeos/farmacologia , Ginkgolídeos/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Barreira Hematoencefálica , Traumatismo por Reperfusão/tratamento farmacológico
13.
Philos Trans A Math Phys Eng Sci ; 381(2249): 20220070, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37150199

RESUMO

The 5-year Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) programme and its 1-year extension ENCORE (ENCORE is the National Capability ORCHESTRA Extension) was an approximately 11-million-pound programme involving seven UK research centres that finished in March 2022. The project sought to radically improve our ability to measure, understand and predict the exchange, storage and export of heat and carbon by the Southern Ocean. It achieved this through a series of milestone observational campaigns in combination with model development and analysis. Twelve cruises in the Weddell Sea and South Atlantic were undertaken, along with mooring, glider and profiler deployments and aircraft missions, all contributing to measurements of internal ocean and air-sea heat and carbon fluxes. Numerous forward and adjoint numerical experiments were developed and supported by the analysis of coupled climate models. The programme has resulted in over 100 peer-reviewed publications to date as well as significant impacts on climate assessments and policy and science coordination groups. Here, we summarize the research highlights of the programme and assess the progress achieved by ORCHESTRA/ENCORE and the questions it raises for the future. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

14.
Appl Opt ; 62(4): 1057-1065, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36821163

RESUMO

A modified uni-traveling carrier photodiode with an electric field control layer is proposed to achieve high-speed and high-power performance at a lower bias voltage. By inserting the 10 nm p-type InGaAs electric field control layer between the intrinsic absorption layer and space layer, the electric field distribution in the depleted absorption layer and depleted non-absorption layer can be changed. It is beneficial for reducing power consumption and heat generation, meanwhile suppressing the space-charge effect. Compared with the original structure without the electric field control layer, the 3 dB bandwidth of the 20 µm diameter novel structure, to the best of our knowledge, is improved by 27.1% to 37.5 GHz with a reverse bias of 2 V, and the RF output power reaches 23.9 dBm at 30 GHz. In addition, under 8 V bias voltage, the bandwidth reaches 47.3 GHz.

15.
Acta Biomater ; 159: 353-366, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36669552

RESUMO

Activation of autophagy in Schwann cells (SCs) has emerged as a powerful trigger for peripheral nerve injury (PNI) repair. Lithium ion (Li+) is a classical autophagy activator that plays an important role in promoting axonal extension and remyelination. However, the therapeutic window of existing lithium drugs is extremely narrow, and the adverse side effects, especially nephrotoxicity, severely limit their therapeutic value. Herein, Li+-doped carbonized polymer dots (Li-CPDs) was synthesized for the first time to change the pharmacokinetics of Li+ from occupying epithelial sodium channels to lipid raft-mediated endocytosis. The in-vivo results confirmed that Li-CPDs could accelerate the removal of myelin debris and promote nerve regeneration via activating autophagy of SCs. Moreover, Li-CPDs exhibited almost no renal toxicity compared to that of raw lithium drugs. Thus, Li-CPDs could serve as a promising Li+-based nanomedicine for PNI regeneration with improved biosafety. STATEMENT OF SIGNIFICANCE: Regardless of the fact that lithium drugs have been used in treatment of mental illness such as manic depression, the systemic side effects and renal metabolic toxicity still seriously restrict their clinical application. Since Li+ and Na+ compete for ion channels of cell membrane, the cell entry efficiency is extremely low and easily affected by body fluctuations, which seems to be an unsolvable problem. Herein, we rationally exploited the endocytotic features of CPDs to develop Li-CPDs. The Li-CPDs improved the entry pathway, greatly reduced nephrotoxicity, and inherited the biological function of Li+ to activate autophagy for promoting peripheral nerve regeneration. Due to the BBB-crossing property of Li-CPDs, it also showed application prospects in future research on central nervous system diseases.


Assuntos
Traumatismos dos Nervos Periféricos , Polímeros , Humanos , Polímeros/metabolismo , Lítio , Células de Schwann/metabolismo , Autofagia , Traumatismos dos Nervos Periféricos/metabolismo , Regeneração Nervosa/fisiologia
16.
Sci Adv ; 9(4): eadd9031, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36706174

RESUMO

Reactive trace gas emissions from the polar oceans are poorly characterized, even though their effects on atmospheric chemistry and aerosol formation are crucial for assessing current and preindustrial aerosol forcing on climate. Here, we present seawater and atmospheric measurements of benzene and toluene, two gases typically associated with pollution, in the remote Southern Ocean and the Arctic marginal ice zone. Their distribution suggests a marine biogenic source. Calculated emission fluxes were 0.023 ± 0.030 (benzene) and 0.039 ± 0.036 (toluene) and 0.023 ± 0.028 (benzene) and 0.034 ± 0.041 (toluene) µmol m-2 day-1 for the Southern Ocean and the Arctic, respectively. Including these average emissions in a chemistry-climate model increased secondary organic aerosol mass concentrations only by 0.1% over the Arctic but by 7.7% over the Southern Ocean, with transient episodes of up to 77.3%. Climate models should consider the hitherto overlooked emissions of benzene and toluene from the polar oceans.

17.
Biomater Sci ; 11(3): 894-907, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36524407

RESUMO

Myocardial fibrosis (MF) is a critical pathological lesion in the progression of various acute and chronic cardiovascular diseases. However, there is still a lack of clinically effective drugs and treatments for MF therapies. Herein, for the first time, we developed fluorescent sulfur-doped carbonized polymer dots (S-CPDs) as new nano-antioxidants to reduce the cardiomyocyte damage caused by reactive oxygen species (ROS) in the early stage of fibrotic lesions. In vitro results suggested that the pre-protection of S-CPDs significantly increased the survival rate of H9c2 cells under severe oxidative stress, inhibited the isoproterenol (ISO)-induced hypertrophy of myocardial cells through improving the content of mitochondria related proteins and adenosine triphosphate (ATP) in cells. Moreover, S-CPD administration could effectively decrease cardiac hypertrophy and promote heart function in MF rat models. The rapid internalization, high biocompatibility and fluorescence imaging potential of S-CPDs revealed their promising application prospects in the diagnoses and treatments of cardiovascular diseases.


Assuntos
Doenças Cardiovasculares , Ratos , Animais , Polímeros/metabolismo , Cardiomegalia/induzido quimicamente , Cardiomegalia/tratamento farmacológico , Cardiomegalia/metabolismo , Mitocôndrias/metabolismo , Fibrose
18.
Neurophotonics ; 9(4): 045002, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36284541

RESUMO

Significance: Functional near-infrared spectroscopy (fNIRS) for resting-state neonatal brain function evaluation provides assistance for pediatricians in diagnosis and monitoring treatment outcomes. Artifact contamination is an important challenge in the application of fNIRS in the neonatal population. Aim: Our study aims to develop a correction algorithm that can effectively remove different types of artifacts from neonatal data. Approach: In the study, we estimate the recognition threshold based on the amplitude characteristics of the signal and artifacts. After artifact recognition, Spline and Gaussian replacements are used separately to correct the artifacts. Various correction method recovery effects on simulated artifact and actual neonatal data are compared using the Pearson correlation ( R ) and root mean square error (RMSE). Simulated data connectivity recovery is used to compare various method performances. Results: The neonatal resting-state data corrected by our method showed better agreement with results by visual recognition and correction, and significant improvements ( R = 0.732 ± 0.155 , RMSE = 0.536 ± 0.339 ; paired t -test, ** p < 0.01 ). Moreover, the method showed a higher degree of recovery of connectivity in simulated data. Conclusions: The proposed algorithm corrects artifacts such as baseline shifts, spikes, and serial disturbances in neonatal fNIRS data quickly and more effectively. It can be used for preprocessing in clinical applications of neonatal fNIRS brain function detection.

19.
Atmos Chem Phys ; 22(1): 641-674, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35136405

RESUMO

Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due to human activities. The nonlinearity of cloud-state changes to aerosol perturbations make it challenging to attribute causality in observed relationships of aerosol radiative forcing. Using correlations to infer causality can be challenging when meteorological variability also drives both aerosol and cloud changes independently. Natural and anthropogenic aerosol perturbations from well-defined sources provide "opportunistic experiments" (also known as natural experiments) to investigate ACI in cases where causality may be more confidently inferred. These perturbations cover a wide range of locations and spatiotemporal scales, including point sources such as volcanic eruptions or industrial sources, plumes from biomass burning or forest fires, and tracks from individual ships or shipping corridors. We review the different experimental conditions and conduct a synthesis of the available satellite datasets and field campaigns to place these opportunistic experiments on a common footing, facilitating new insights and a clearer understanding of key uncertainties in aerosol radiative forcing. Cloud albedo perturbations are strongly sensitive to background meteorological conditions. Strong liquid water path increases due to aerosol perturbations are largely ruled out by averaging across experiments. Opportunistic experiments have significantly improved process-level understanding of ACI, but it remains unclear how reliably the relationships found can be scaled to the global level, thus demonstrating a need for deeper investigation in order to improve assessments of aerosol radiative forcing and climate change.

20.
Sci Rep ; 11(1): 13584, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193883

RESUMO

The flux of CO2 between the atmosphere and the ocean is often estimated as the air-sea gas concentration difference multiplied by the gas transfer velocity (K660). The first order driver for K660 over the ocean is wind through its influence on near surface hydrodynamics. However, field observations have shown substantial variability in the wind speed dependencies of K660. In this study we measured K660 with the eddy covariance technique during a ~ 11,000 km long Southern Ocean transect. In parallel, we made a novel measurement of the gas transfer efficiency (GTE) based on partial equilibration of CO2 using a Segmented Flow Coil Equilibrator system. GTE varied by 20% during the transect, was distinct in different water masses, and related to K660. At a moderate wind speed of 7 m s-1, K660 associated with high GTE exceeded K660 with low GTE by 30% in the mean. The sensitivity of K660 towards GTE was stronger at lower wind speeds and weaker at higher wind speeds. Naturally-occurring organics in seawater, some of which are surface active, may be the cause of the variability in GTE and in K660. Neglecting these variations could result in biases in the computed air-sea CO2 fluxes.

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