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1.
Glob Chang Biol ; 30(1): e17005, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37905717

RESUMO

Climate change has induced substantial shifts in vegetation boundaries such as alpine treelines and shrublines, with widespread ecological and climatic influences. However, spatial and temporal changes in the upper elevational limit of alpine grasslands ("alpine grasslines") are still poorly understood due to lack of field observations and remote sensing estimates. In this study, taking the Tibetan Plateau as an example, we propose a novel method for automatically identifying alpine grasslines from multi-source remote sensing data and determining their positions at 30-m spatial resolution. We first identified 2895 mountains potentially having alpine grasslines. On each mountain, we identified a narrow area around the upper elevational limit of alpine grasslands where the alpine grassline was potentially located. Then, we used linear discriminant analysis to adaptively generate from Landsat reflectance features a synthetic feature that maximized the difference between vegetated and unvegetated pixels in each of these areas. After that, we designed a graph-cut algorithm to integrate the advantages of the Otsu and Canny approaches, which was used to determine the precise position of the alpine grassline from the synthetic feature image. Validation against alpine grasslines visually interpreted from a large number of high-spatial-resolution images showed a high level of accuracy (R2 , .99 and .98; mean absolute error, 22.6 and 36.2 m, vs. drone and PlanetScope images, respectively). Across the Tibetan Plateau, the alpine grassline elevation ranged from 4038 to 5380 m (5th-95th percentile), lower in the northeast and southeast and higher in the southwest. This study provides a method for remotely sensing alpine grasslines for the first-time at large scale and lays a foundation for investigating their responses to climate change.


Assuntos
Mudança Climática , Tecnologia de Sensoriamento Remoto , Tibet , Pradaria , Ecossistema
2.
Dermatol Ther ; 35(12): e15942, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36254686

RESUMO

We here report a case of a middle-aged man with an unusual case of bullous lichen sclerosus complicated with generalized morphea. He showed initial recurrent flaccid bullae, followed by ivory-white sclerotic plaques and extensive skin sclerosis, with additional walking disorder caused by knee-joint contracture, and ulcers on the lower extremities and back. The patient had no visceral involvement. After oral hydroxychloroquine and oral corticosteroids failed, the patient was given tofacitinib, which resolved his ulcers after 4 weeks and ameliorated his knee-joint contracture and skin sclerosis within 4 months. Owing to the occurrence of diffuse large B-cell lymphoma, he stopped using tofacitinib, and the ulcer and walking disorder reappeared. This is rare case of bullous lichen sclerosus-generalized morphea overlap syndrome. The patient recovered well after treatment with tofacitinib. His symptoms recurred after discontinuation of tofacitinib.


Assuntos
Contratura , Líquen Escleroso e Atrófico , Esclerodermia Localizada , Escleroderma Sistêmico , Dermatopatias , Pessoa de Meia-Idade , Masculino , Humanos , Esclerodermia Localizada/complicações , Esclerodermia Localizada/diagnóstico , Esclerodermia Localizada/tratamento farmacológico , Esclerose/complicações , Úlcera , Recidiva Local de Neoplasia
3.
Molecules ; 27(11)2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35684379

RESUMO

A magnetic metal-organic framework nanocomposite (magnetic MIL-68(Ga)) was synthesized through a "one pot" reaction and used for heavy metal ion removal. The morphology and elemental properties of the nanocomposite were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), as well as zeta potential. Moreover, the factors affecting the adsorption capacity of the nanocomposite, including time, pH, metal ion type and concentration, were studied. It was found that the adsorption capacity of magnetic MIL-68(Ga) for Pb2+ and Cu2+ was 220 and 130 mg/g, respectively. Notably, the magnetic adsorbents could be separated easily using an external magnetic field, regenerated by ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) and reused three times, in favor of practical application. This study provides a reference for the rapid separation and purification of heavy metal ions from wastewater.


Assuntos
Estruturas Metalorgânicas , Metais Pesados , Poluentes Químicos da Água , Adsorção , Íons , Fenômenos Magnéticos , Estruturas Metalorgânicas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química
4.
Environ Pollut ; 355: 124194, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38782158

RESUMO

Nowadays, silica products are widely used in daily life, especially in skin applications, which inevitably increases the risk of silica exposure in general population. However, inadequate awareness of silica's potential hazards and lack of self-protection are of concern. Systemic sclerosis (SSc) is characterized by progressive tissue fibrosis under environmental and genetic interactions. Silica exposure is considered an important causative factor for SSc, but its pathogenesis remains unclear. Within this study, we showed that lower doses of silica significantly promoted the proliferation, migration, and activation of human skin fibroblasts (HSFs) within 24 h. Silica injected subcutaneously into mice induced and exacerbated skin fibrosis. Notably, silica increased histone deacetylase-4 (HDAC4) expression by inducing its DNA hypomethylation in normal HSFs. The elevated HDAC4 expression was also confirmed in SSc HSFs. Furthermore, HDAC4 was positively correlated with Smad2/3 phosphorylation and COL1, α-SMA, and CTGF expression. The HDAC4 inhibitor LMK235 mitigated silica-induced upregulation of these factors and alleviated skin fibrosis in SSc mice. Taken together, silica induces and exacerbates skin fibrosis in SSc patients by targeting the HDAC4/Smad2/3 pathway. Our findings provide new insights for evaluating the health hazards of silica exposure and identify HDAC4 as a potential interventional target for silica-induced SSc skin fibrosis.


Assuntos
Fibrose , Histona Desacetilases , Escleroderma Sistêmico , Dióxido de Silício , Pele , Proteína Smad2 , Proteína Smad3 , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/induzido quimicamente , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Animais , Camundongos , Humanos , Proteína Smad3/metabolismo , Pele/metabolismo , Proteína Smad2/metabolismo , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Transdução de Sinais/efeitos dos fármacos
5.
Biomed Pharmacother ; 166: 115282, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37567070

RESUMO

Systemic sclerosis (SSc) is an autoimmune disease characterized by immune dysfunction, vascular system dysfunction, and tissue fibrosis. Vascular injury, vascular remodeling, and endothelial dysfunction are the hallmark pathological changes of the disease. In the early stages of SSc development, endothelial cell injury and apoptosis can lead to vascular and perivascular inflammation, oxidative stress, and tissue hypoxia, which can cause clinical manifestations in various organs from the skin to the parenchymal organs. Early diagnosis and rational treatment can improve patient survival and quality of life. Ancillary examinations such as nailfold capillaroscopy as well as optical coherence tomography can help early detect vascular injury in SSc patients. Studies targeting the mechanisms of vascular lesions will provide new perspectives for treatment of SSc.


Assuntos
Escleroderma Sistêmico , Doenças Vasculares , Lesões do Sistema Vascular , Humanos , Qualidade de Vida , Fibrose
6.
Int Immunopharmacol ; 116: 109764, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36706594

RESUMO

Scleroderma is an autoimmune disease mainly characterized by progressive fibrosis of the skin. There are two types of scleroderma, namely localized scleroderma (LS) and systemic sclerosis (SSc); skin lesions in both types of scleroderma are histologically identical. Progressive skin sclerosis induces psychological and ecological burden for scleroderma patients. However, there is no effective treatment for scleroderma due to its unclear etiology. Aryl hydrocarbon receptor (AhR) is recognized as an environmental chemical effector that can respond to ultraviolet radiation, which has been demonstrated to participate in the pathogenesis of SSc in our previous study. In this study, we verify whether the anti-fibrosis effect of ultraviolet A1 (UVA1) phototherapy could be partially induced through Ficz/AhR/MAPK signaling activation for fibrotic lesions in both SSc and LS patients. This is the first study to show the association between the AhR pathway and the anti-fibrotic mechanism of UVA1 phototherapy, which provides additional evidence of the role of AhR in the fibrotic mechanism of systemic scleroderma from different perspectives. Ficz and other AhR agonists may replace UVA1 phototherapy as anti-fibrotic agents in scleroderma.


Assuntos
Esclerodermia Localizada , Escleroderma Sistêmico , Humanos , Esclerodermia Localizada/radioterapia , Esclerodermia Localizada/metabolismo , Raios Ultravioleta , Receptores de Hidrocarboneto Arílico , Escleroderma Sistêmico/radioterapia , Escleroderma Sistêmico/patologia , Colágeno/metabolismo
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