Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 277
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Biol ; 21(12): e3002387, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38048360

RESUMO

Lysophosphatidylserine (LysoPS) is a naturally occurring lipid mediator involved in various physiological and pathological processes especially those related to the immune system. GPR34, GPR174, and P2Y10 have been identified as the receptors for LysoPS, and its analogues have been developed as agonists or antagonists for these receptors. However, the lack of structural information hinders the drug development with novel characteristics, such as nonlipid ligands and allosteric modulators. Here, we determined the structures of human GPR34 and GPR174 in complex with LysoPS and G protein by cryo-EM. Combined with structural analysis and functional studies, we elucidated the lipid-binding modes of these receptors. By structural comparison, we identified the structural features of GPR34 and GPR174 in active state. Taken together, our findings provide insights into ligand recognition and signaling of LysoPS receptors and will facilitate the development of novel therapeutics for related inflammatory diseases and autoimmune diseases.


Assuntos
Lisofosfolipídeos , Receptores Acoplados a Proteínas G , Humanos , Ligantes , Lisofosfolipídeos/farmacologia , Lisofosfolipídeos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Lisofosfolipídeos/agonistas , Receptores de Lisofosfolipídeos/metabolismo
2.
Nano Lett ; 24(33): 10196-10201, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39132984

RESUMO

Cesium lead iodide light-emitting diodes (LEDs) are attractive for displays due to their Rec. 2020 red standard compliance. However, achieving high current efficiencies (CEs), which is important for displays, is challenging because their emission spectrum is near the tail of the photopic luminosity function. Substituting some iodine with bromine can improve CEs by enlarging the bandgap, but defects easily form in iodine-bromine mixed perovskites. Here, we successfully reduced defect formation by adding organic ammonium salts and zwitterions. The organic ammonium salts do not form low-dimensional perovskites under the hydrogen bonding interaction of zwitterions. Instead, they passivate the cesium vacancy by forming new hydrogen bonds after perovskite crystallization. This approach leads to a red perovskite LED with a high CE of 12.8 cd A-1 and a peak external quantum efficiency of 20.3%, meeting the Rec. 2020 standard. It can be extended to large-area devices (2500 mm2) without a significant efficiency loss.

3.
Anal Chem ; 96(24): 9935-9943, 2024 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-38847283

RESUMO

Biopharmaceuticals, such as monoclonal antibodies (mAbs), need to maintain their chemical and physical stability in formulations throughout their lifecycle. It is known that exposure of mAbs to light, particularly UV, triggers chemical and physical degradation, which can be exacerbated by trace amounts of photosensitizers in the formulation. Although routine assessments of degradation following defined UV dosages are performed, there is a fundamental lack of understanding regarding the intermediates, transient reactive species, and radicals formed during illumination, as well as their lifetimes and immediate impact post-illumination. In this study, we used light-coupled NMR spectroscopy to monitor in situ live spectral changes in sealed samples during and after UV-A illumination of different formulations of four mAbs without added photosensitizers. We observed a complex evolution of spectra, reflecting the appearance within minutes of transient radicals during illumination and persisting for minutes to tens of minutes after the light was switched off. Both mAb and excipient signals were strongly affected by illumination, with some exhibiting fast irreversible photodegradation and others exhibiting partial recovery in the dark. These effects varied depending on the mAb and the presence of excipients, such as polysorbate 80 (PS80) and methionine. Complementary ex situ high-performance size-exclusion chromatography analysis of the same formulations post-UV exposure in the chamber revealed significant loss of purity, confirming formulation-dependent degradation. Both approaches suggested the presence of degradation processes initiated by light but continuing in the dark. Further studies on photoreaction intermediates and transient reactive species may help mitigate the impact of light on biopharmaceutical degradation.


Assuntos
Anticorpos Monoclonais , Raios Ultravioleta , Anticorpos Monoclonais/química , Espectroscopia de Ressonância Magnética , Fotólise , Composição de Medicamentos , Estabilidade de Medicamentos , Luz
4.
Small ; 20(29): e2311500, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38372501

RESUMO

Singlet oxygen (term symbol 1Δg, hereafter 1O2), a reactive oxygen species, has recently attracted increasing interest in the field of rechargeable batteries and electrocatalysis and photocatalysis. These sustainable energy conversion and storage technologies are of vital significance to replace fossil fuels and promote carbon neutrality and finally tackle the energy crisis and climate change. Herein, the recent progresses of 1O2 for energy storage and conversion is summarized, including physical and chemical properties, formation mechanisms, detection technologies, side reactions in rechargeable batteries and corresponding inhibition strategies, and applications in electrocatalysis and photocatalysis. The formation mechanisms and inhibition strategies of 1O2 in particular aprotic lithium-oxygen (Li-O2) batteries are highlighted, and the applications of 1O2 in photocatalysis and electrocatalysis is also emphasized. Moreover, the confronting challenges and promising directions of 1O2 in energy conversion and storage systems are discussed.

5.
Opt Express ; 32(2): 2884-2893, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297806

RESUMO

We numerically investigate the figures of merit for single-photon emission in a planar GaAs-on-insulator waveguide featuring a V-groove geometry. Thanks to a field enhancement effect arising due to boundary conditions of this waveguide, the structure features an ultra-small mode area enabling a factor of a maximum 2.8 times enhancement of the Purcell factor for quantum dot and a more significant 7 times enhancement for the atomic-size solid-state emitters with the aligned dipole orientation. In addition, the coupling efficiency to the fundamental quasi-TE mode is also improved. To take into account potential on-chip integration, we further show that the V-groove mode profile can be converted using a tapering section to the mode profile of a standard ridge waveguide while maintaining both the high Purcell factor and the good fundamental mode coupling efficiency.

6.
Environ Res ; 242: 117754, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38016497

RESUMO

Submerged macrophytes play important roles in nutrient cycling and are widely used in ecological restoration to alleviate eutrophication and improve water quality in lakes. Epiphytic microbial communities on leaves of submerged macrophytes might promote nitrogen cycling, but the mechanisms and quantification of their contributions remain unclear. Here, four types of field zones with different nutrient levels and submerged macrophytes, eutrophic + Vallisneria natans (EV), eutrophic + V. natans + Hydrilla verticillata, mesotrophic + V. natans + H. verticillata, and eutrophic without macrophytes were selected to investigate the microbial communities that involved in nitrification and denitrification. The alpha diversity of bacterial community was higher in the phyllosphere than in the water, and that of H. verticillata was higher compared to V. natans. Bacterial community structures differed significantly between the four zones. The highest relative abundance of dominant bacterioplankton genera involved in nitrification and denitrification was observed in the EV zone. Similarly, the alpha diversity of the epiphytic ammonia-oxidizing archaea and nosZI-type denitrifiers were highest in the EV zone. Consist with the diversity patterns, the potential denitrification rates were higher in the phyllosphere than those in the water. Higher potential denitrification rates in the phyllosphere were also found in H. verticillata than those in V. natans. Anammox was not detected in all samples. Nutrient loads, especially nitrogen concentrations were important factors influencing potential nitrification, denitrification rates, and bacterial communities, especially for the epiphytic nosZI-type taxa. Overall, we observed that the phyllosphere harbors more microbes and promotes higher denitrification rates compared to water, and epiphytic bacterial communities are shaped by nitrogen nutrients and macrophyte species, indicating that epiphytic microorganisms of submerged macrophytes can effectively contribute to the N removal in shallow lakes.


Assuntos
Desnitrificação , Hydrocharitaceae , Nitrogênio , Nitrificação , Bactérias/genética , Organismos Aquáticos , Lagos/microbiologia
7.
Addict Biol ; 29(3): e13382, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38488467

RESUMO

Methamphetamine (METH) is a highly addictive psycho-stimulant that induces addictive behaviour by stimulating increased dopamine release in the nucleus accumbens (NAc). The sarco/endoplasmic reticulum calcium ion transport ATPases (SERCA or ATP2A) is a calcium ion (Ca2+) pump in the endoplasmic reticulum (ER) membrane. SERCA2b is a SERCA subtype mainly distributed in the central nervous system. This study used conditioned place preference (CPP), a translational drug reward model, to observe the effects of SERCA and SERCA2b on METH-CPP in mice. Result suggested that the activity of SERCA was significantly decreased in NAc after METH-CPP. Intraperitoneal SERCA agonist CDN1163 injection or bilateral CDN1163 microinjection in the NAc inhibited METH-CPP formation. SERCA2b overexpression by the Adeno-associated virus can reduce the DA release of NAc and inhibit METH-CPP formation. Although microinjection of SERCA inhibitor thapsigargin in the bilateral NAc did not significantly aggravate METH-CPP, interference with SERCA2b expression in NAc by adeno-associated virus increased DA release and promoted METH-CPP formation. METH reduced the SERCA ability to transport Ca2+ into the ER in SHSY5Y cells in vitro, which was reversed by CDN1163. This study revealed that METH dysregulates intracellular calcium balance by downregulating SERCA2b function, increasing DA release in NAc and inducing METH-CPP formation. Drugs that target SERCA2b may have the potential to treat METH addiction.


Assuntos
Benzamidas , Estimulantes do Sistema Nervoso Central , Metanfetamina , Camundongos , Animais , Metanfetamina/farmacologia , Metanfetamina/metabolismo , Núcleo Accumbens , Cálcio/metabolismo , Aminoquinolinas/metabolismo , Aminoquinolinas/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/metabolismo
8.
BMC Public Health ; 24(1): 1682, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914970

RESUMO

BACKGROUND: Falls are common in the elderly and can lead to adverse consequences, like injuries, hospitalization, disability even mortality. Successful ageing emerged in sight to assess physical, psychological and social status of older adults. This study is conducted to explore the association between them in a large Indian community-dwelling population. METHODS: Data were based on the wave 1 survey of the Longitudinal Ageing Study in India (LASI). People aged 60 and above with complete information were included. The elderly met five standards including absence of chronic diseases, freedom from disability, high cognitive ability, free from depressive symptoms and active social engagement, were classified into successful agers. The assessment of falls, fall-related injuries and multiple falls depended on interview. Multivariate logistic regression was conducted to find the associations between falls, fall-injury, multiple falls and successful ageing after adjusting both socio-demographic and biological covariates. The log-likelihood ratio test was calculated interactions in subgroups. RESULTS: 31,345 participants in LASI were finally included in our study. Of them, 20.25% reported fall, and 25% were classified into successful agers. After full adjustment, successful ageing was negatively associated with falls (OR 0.70; 95%CI 0.65-0.76) and multiple falls (OR 0.70; 95%CI 0.63-0.78). And the association did not show the significance in older adults with fall-related injuries (OR 0.86; 95%CI 0.72-1.04). CONCLUSIONS: Successful ageing was negatively associated with falls and multiple falls, but not fall-related injuries in older people in India. Future studies are demanded to explore the causal relationship and to reveal the underlying mechanism.


Assuntos
Acidentes por Quedas , Humanos , Acidentes por Quedas/estatística & dados numéricos , Índia/epidemiologia , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Estudos Transversais , Estudos Longitudinais , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Fatores de Risco
9.
Lett Appl Microbiol ; 77(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38366661

RESUMO

This study aims to isolate microbial strains for producing mono-rhamnolipids with high proportion. Oily sludge is rich in petroleum and contains diverse biosurfactant-producing strains. A biosurfactant-producing strain LP20 was isolated from oily sludge, identified as Pseudomonas aeruginosa based on phylogenetic analysis of 16S rRNA. High-performance liquid chromatography-mass spectrometry results indicated that biosurfactants produced from LP20 were rhamnolipids, mainly containing Rha-C8-C10, Rha-C10-C10, Rha-Rha-C8-C10, Rha-Rha-C10-C10, Rha-C10-C12:1, and Rha-C10-C12. Interestingly, more mono-rhamnolipids were produced by strain LP20 with a relative abundance of 64.5%. Pseudomonas aeruginosa LP20 optimally produced rhamnolipids at a pH of 7.0 and a salinity of 0.1% using glycerol and nitrate. The culture medium for rhamnolipids by strain LP20 was optimized by response surface methodology. LP20 produced rhamnolipids up to 6.9 g L-1, increased by 116%. Rhamnolipids produced from LP20 decreased the water surface tension to 28.1 mN m-1 with a critical micelle concentration of 60 mg L-1. The produced rhamnolipids emulsified many hydrocarbons with EI24 values higher than 56% and showed antimicrobial activity against Staphylococcus aureus and Cladosporium sp. with inhibition rates 48.5% and 17.9%, respectively. Pseudomonas aeruginosa LP20 produced more proportion of mono-rhamnolipids, and the LP20 rhamnolipids exhibited favorable activities and promising potential in microbial-enhanced oil recovery, bioremediation, and agricultural biocontrol.


Assuntos
Decanoatos , Pseudomonas aeruginosa , Ramnose/análogos & derivados , Esgotos , Pseudomonas aeruginosa/genética , Filogenia , RNA Ribossômico 16S/genética , Glicolipídeos , Tensoativos/farmacologia
10.
Biomed Chromatogr ; : e5980, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39189506

RESUMO

The antioxidant activity of Ginkgo biloba leaf (GBL) extract is closely related to its efficacy against various diseases; however, the antioxidant activities of the specific constituents of GBL remain unclear. In this study, 194 GBL constituents were identified using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry, including 97 flavonoids, 37 terpenoids, 29 lignans, 19 carboxylic acids, 5 alkylphenolic acids, 5 alkylphenols, and 2 other compounds. The cleavage rules of the main constituents of GBL were dissected in detail. The 36 GBL constituents with high antioxidant activity were subsequently discovered using the oxygen radical absorbance capacity assay, including 30 flavonoids and six carboxylic acids. Finally, an HPLC analysis method was established to determine the content of the nine major antioxidants in the three batches of GBL. Among them, kaempferol 3-O-ß-D-(6″-p-coumaroyl) glucopyranosyl-(1-2)-α-L-rhamnopyranoside, kaempferol-3-O-rutinoside, and rutin exhibited high antioxidant activity and were found in significant amounts in GBL, with concentrations greater than 0.7 mg/g. These results provide an important reference for the development of pharmaceuticals and health products containing GBL.

11.
BMC Palliat Care ; 23(1): 51, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38389106

RESUMO

BACKGROUND: Predicting mortality in the emergency department (ED) is imperative to guide palliative care and end-of-life decisions. However, the clinical usefulness of utilizing the existing screening tools still leaves something to be desired. METHODS: We advanced the screening tool with the A-qCPR (Age, qSOFA (quick sepsis-related organ failure assessment), cancer, Performance Status Scale, and DNR (Do-Not-Resuscitate) risk score model for predicting one-year mortality in the emergency department of Taipei City Hospital of Taiwan with the potential of hospice need and evaluated its performance compared with the existing screening model. We adopted a large retrospective cohort in conjunction with in-time (the trained and the holdout validation cohort) for the development of the A-qCPR model and out-of-time validation sample for external validation and model robustness to variation with the calendar year. RESULTS: A total of 10,474 patients were enrolled in the training cohort and 33,182 patients for external validation. Significant risk scores included age (0.05 per year), qSOFA ≥ 2 (4), Cancer (5), Eastern Cooperative Oncology Group (ECOG) Performance Status score ≥ 2 (2), and DNR status (2). One-year mortality rates were 13.6% for low (score ≦ 3 points), 29.9% for medium (3 < Score ≦ 9 points), and 47.1% for high categories (Score > 9 points). The AUROC curve for the in-time validation sample was 0.76 (0.74-0.78). However, the corresponding figure was slightly shrunk to 0.69 (0.69-0.70) based on out-of-time validation. The accuracy with our newly developed A-qCPR model was better than those existing tools including 0.57 (0.56-0.57) by using SQ (surprise question), 0.54 (0.54-0.54) by using qSOFA, and 0.59 (0.59-0.59) by using ECOG performance status score. Applying the A-qCPR model to emergency departments since 2017 has led to a year-on-year increase in the proportion of patients or their families signing DNR documents, which had not been affected by the COVID-19 pandemic. CONCLUSIONS: The A-qCPR model is not only effective in predicting one-year mortality but also in identifying hospice needs. Advancing the screening tool that has been widely used for hospice in various scenarios is particularly helpful for facilitating the end-of-life decision-making process in the ED.


Assuntos
Hospitais para Doentes Terminais , Neoplasias , Humanos , Estudos Retrospectivos , Pandemias , Serviço Hospitalar de Emergência , Morte , Prognóstico
12.
Chem Biodivers ; 21(4): e202302053, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38270380

RESUMO

Five compounds (1-5), one long-chain fatty acid (1), two thiophenes (2 and 3), one alkaloid (4), and one phenyl ester (5), were isolated from the aerial part of Echinops davuricus. The structures of the products were established by performing detailed nuclear magnetic resonance (NMR) analysis, and the structure of compound 1 was determined via high-resolution electrospray ionization mass spectrometry (HRESIMS) and NMR. Compounds 1, 4, and 5 were isolated from Echinops davuricus for the first time. Based on network pharmacology methods, AKR1B10 was selected as a key anticancer target. Compounds 1 and 5 exhibited significant AKR1B10 inhibitory activities, with IC50 values of 156.0±1.00 and 146.2±1.50 nM, respectively, with epalrestat used as the positive control (81.09±0.61 nM). Additionally, the interactions between the active compounds and AKR1B10 were evaluated via molecular docking. Ultimately, the GO and KEGG enrichment analysis indicated that the key signaling pathways associated with the active compounds may be related to the PI3K-Akt, MAPK, apoptotic, cellular senescence, and TNF signaling pathways and the human diseases corresponding to the targets are cancer. Our study reveals for the first time the anticancer properties of Echinops davuricus and provides a comprehensive understanding of its application in traditional medicine.


Assuntos
Medicamentos de Ervas Chinesas , Fosfatidilinositol 3-Quinases , Humanos , Simulação de Acoplamento Molecular , Tenrecidae , Ésteres , Ácidos Graxos , Aldo-Ceto Redutases
13.
Environ Toxicol ; 39(3): 1769-1779, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38064270

RESUMO

BACKGROUND: Cardiovascular diseases represent a significant complication arising from chronic kidney disease (CKD). Vascular calcification is an important risk factor for cardiovascular diseases. Reducing vascular calcification is therefore critical to reducing mortality in CKD patients. HYPOTHESIS: This study aims to establish a vascular calcification model in rats with CKD by administering subcutaneous injections of calcitriol in combination with a high-calcium and high-phosphorus diet. METHODS: The rats were divided into the CKD vascular calcification model group (subtotal nephrectomy+ [SNx+]) and the sham-operated control group (subtotal nephrectomy- [SNx-]). The rats in the SNx(+) group were administered high-calcium and high-phosphorus feeds following a 5/6 nephrectomy. Calcitriol (1 µg/kg, three times a week) was injected subcutaneously at weeks 0, 4, 8, and 12 after the operation. Measurements of body weight, urine, serum biochemical indicators and vascular calcification level were conducted in rats. RESULTS: (1) Compared with the SNx(-) group, rats in the SNx(+) group experienced an increase in 24-h urine output, urinary phosphorus, and urinary microprotein excretion, along with the development of severe anemia. Additionally, there was a notable elevation in serum phosphorus, blood urea nitrogen, blood creatinine, fibroblast growth factor 23 (FGF-23), and intact parathyroid hormone levels, accompanied by severe hypoproteinemia at week 12. (2) The results of micro-compuyed tomography (µCT) and alizarin S staining of the thoracic aorta demonstrated an increase in vascular calcification in the SNx(+) group. (3) The expression levels of vascular calcification-related proteins were increased. CONCLUSIONS: The administration of calcitriol combined with a high-calcium and high-phosphorus diet was found to induce vascular calcification in CKD rats, leading to a disturbance in mineral metabolism. Vascular calcification was effectively induced in CKD rats after 12 weeks of modeling, thereby presenting a novel approach for establishing a vascular calcification model in CKD rats, helping to elucidate this clinical condition and its underlying molecular mechanisms.


Assuntos
Doenças Cardiovasculares , Insuficiência Renal Crônica , Calcificação Vascular , Humanos , Ratos , Animais , Calcitriol , Cálcio/metabolismo , Doenças Cardiovasculares/complicações , Calcificação Vascular/complicações , Calcificação Vascular/metabolismo , Fósforo , Dieta
14.
Environ Toxicol ; 39(4): 2363-2373, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38156404

RESUMO

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD). VC is a gene-regulated process similar to osteogenic differentiation. There are still no convincing schemes to prevent and reduce the development of VC. It has been reported that hypoxia-inducing factor 1α (HIF-1α) and endothelin-1(ET-1) are related to VC. In this study, we found that the expression of ET-1 and HIF-1α was enhanced after VC, the interaction between HIF-1α and ET-1 was confirmed by CO-IP and luciferase experiments. We found that ET-1 was an upregulated differential gene of calcified vascular smooth muscle cells (VSMCs) through gene sequencing. However, hypoxia-inducing factor 2α (HIF-2α) and HIF-1α have antagonistic effects on each other. HIF-1α is a pro-inflammatory cytokine, and HIF-2α can improve inflammation and fibrosis. Roxadustat, as a selective PHD3 inhibitor, preferentially activates HIF-2α. It is still unclear whether roxadustat improves VC in CKD by regulating the expression of HIF-2α/HIF-1α. Alizarin red staining and western blot as well as immunohistochemical results showed that roxadustat could significantly reduce the degree of vascular and VSMCs calcification in CKD rats. Serum HIF-1α and ET-1 were significantly decreased after roxadustat treatment. In addition, western blot results showed that roxadustat could decrease the expression of HIF-1α and ET-1 in vascular tissues and calcified VSMC, but HIF-2α expression significantly increased. Interestingly, our study confirmed that activation of HIF-1α or inhibition of HIF-2α reversed the ameliorating effect of roxadustat on VC, proving that the effect mediated by roxadustat is HIF-2α/HIF-1α dependent. We have demonstrated for the first time that roxadustat improves VC in CKD rats by regulating HIF-2α/HIF-1α, thus providing a new idea for the application of roxadustat in VC of CKD.


Assuntos
Insuficiência Renal Crônica , Calcificação Vascular , Ratos , Animais , Osteogênese , Calcificação Vascular/tratamento farmacológico , Calcificação Vascular/prevenção & controle , Calcificação Vascular/complicações , Hipóxia , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia
15.
Sensors (Basel) ; 24(14)2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39065831

RESUMO

Aiming at the problem of the difficult segmentation of adherent images due to the not fully convex shape of peanut pods, their complex surface texture, and their diverse structures, a multimodal fusion algorithm is proposed to achieve a 2D segmentation of adherent peanut images with the assistance of 3D point clouds. Firstly, the point cloud of a running peanut is captured line by line using a line structured light imaging system, and its three-dimensional shape is obtained through splicing and combining it with a local surface-fitting algorithm to calculate a normal vector and curvature. Seed points are selected based on the principle of minimum curvature, and neighboring points are searched using the KD-Tree algorithm. The point cloud is filtered and segmented according to the normal angle and the curvature threshold until achieving the completion of the point cloud segmentation of the individual peanut, and then the two-dimensional contour of the individual peanut model is extracted by using the rolling method. The search template is established, multiscale feature matching is implemented on the adherent image to achieve the region localization, and finally, the segmentation region is optimized by an opening operation. The experimental results show that the algorithm improves the segmentation accuracy, and the segmentation accuracy reaches 96.8%.

16.
Sensors (Basel) ; 24(3)2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38339584

RESUMO

In the face of complex scenarios, the information insufficiency of classification tasks dominated by a single modality has led to a bottleneck in classification performance. The joint application of multimodal remote sensing data for surface observation tasks has garnered widespread attention. However, issues such as sample differences between modalities and the lack of correlation in physical features have limited the performance of classification tasks. Establishing effective interaction between multimodal data has become another significant challenge. To fully integrate heterogeneous information from multiple modalities and enhance classification performance, this paper proposes a dual-branch cross-Transformer feature fusion network aimed at joint land cover classification of hyperspectral imagery (HSI) and Light Detection and Ranging (LiDAR) data. The core idea is to leverage the potential of convolutional operators to represent spatial features, combined with the advantages of the Transformer architecture in learning remote dependencies. The framework employs an improved self-attention mechanism to aggregate features within each modality, highlighting the spectral information of HSI and the spatial (elevation) information of LiDAR. The feature fusion module based on cross-attention integrates deep features from two modalities, achieving complementary information through cross-modal attention. The classification task is performed using jointly obtained spectral and spatial features. Experiments were conducted on three multi-source remote sensing classification datasets, demonstrating the effectiveness of the proposed model compared to existing methods.

17.
Molecules ; 29(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38792128

RESUMO

The main varieties of Echinopsis Radix recorded in the Chinese Pharmacopoeia are the roots of Echinops latifolius Tausch or Echinops grijsii Hance. However, the chemical constituents and biological activities of this herb have not been reviewed. In order to clarify the chemical constituents of the main varieties of this herb and improve the quality of Chinese medicinal material resources, this paper systematically reviewed their chemical constituents and related biological activities. Phytochemical investigations reveal eighty-five compounds including fort y-nine thiophenes (1-49), eight flavonoids (50-57), seven caffeic acids and its derivatives (58-64), eight sesquiterpenoids (65-72), and thirteen triterpenoids and other compounds (73-85) were reported from Echinopsis Radix. The review of biological activities suggests that thiophenes are the main secondary metabolites of the medicinal material which exert antitumor, insecticidal and antifungal activities. In addition, caffeic acid and its derivatives and sesquiterpenes are potential active ingredients worthy of further study. This review provides an important scientific basis for the development of active ingredients and resource quality evaluation of Echinopsis Radix.


Assuntos
Compostos Fitoquímicos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Echinops (Planta)/química , Humanos , Raízes de Plantas/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Animais , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Flavonoides/química , Flavonoides/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia
18.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(3): 494-502, 2024 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-38932535

RESUMO

In the extraction of fetal electrocardiogram (ECG) signal, due to the unicity of the scale of the U-Net same-level convolution encoder, the size and shape difference of the ECG characteristic wave between mother and fetus are ignored, and the time information of ECG signals is not used in the threshold learning process of the encoder's residual shrinkage module. In this paper, a method of extracting fetal ECG signal based on multi-scale residual shrinkage U-Net model is proposed. First, the Inception and time domain attention were introduced into the residual shrinkage module to enhance the multi-scale feature extraction ability of the same level convolution encoder and the utilization of the time domain information of fetal ECG signal. In order to maintain more local details of ECG waveform, the maximum pooling in U-Net was replaced by Softpool. Finally, the decoder composed of the residual module and up-sampling gradually generated fetal ECG signals. In this paper, clinical ECG signals were used for experiments. The final results showed that compared with other fetal ECG extraction algorithms, the method proposed in this paper could extract clearer fetal ECG signals. The sensitivity, positive predictive value, and F1 scores in the 2013 competition data set reached 93.33%, 99.36%, and 96.09%, respectively, indicating that this method can effectively extract fetal ECG signals and has certain application values for perinatal fetal health monitoring.


Assuntos
Algoritmos , Eletrocardiografia , Processamento de Sinais Assistido por Computador , Humanos , Eletrocardiografia/métodos , Gravidez , Feminino , Monitorização Fetal/métodos , Feto/fisiologia
19.
Angew Chem Int Ed Engl ; 63(26): e202406069, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38630112

RESUMO

The construction of C(sp3)-N bonds via direct N-centered radical addition with olefins under benign conditions is a desirable but challenging strategy. Herein, we describe an organo-photocatalytic approach to achieve anti-Markovnikov alkene hydroamidation with sulfonyl azides in a highly efficient manner under transition-metal-free and mild conditions. A broad range of substrates, including both activated and unactivated alkenes, are suitable for this protocol, providing a convenient and practical method to construct sulfonylamide derivatives. A synergistic experimental and computational mechanistic study suggests that the additive, Hantzsch ester (HE), might undergo a triplet-triplet energy transfer manner to achieve photosensitization by the organo-photocatalyst under visible light irradiation. Next, the resulted triplet excited state 3HE* could lead to a homolytic cleavage of C4-H bond, which triggers a straightforward H-atom transfer (HAT) style in converting sulfonyl azide to the corresponding key amidyl radical. Subsequently, the addition of the amidyl radical to alkene followed by HAT from p-toluenethiol could proceed to afford the desired anti-Markovnikov hydroamidation product. It is worth noting that mechanistic pathway bifurcation could be possible for this reaction. A feasible radical chain propagation mechanistic pathway is also proposed to rationalize the high efficiency of this reaction.

20.
Cardiovasc Diabetol ; 22(1): 268, 2023 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-37777746

RESUMO

BACKGROUND: Previous studies have reported that inflammatory responses can promote the onset of cardiovascular diseases; however, its association with cardiac conduction disorders remains unclear. The present community-based cohort study aimed to elucidate the effects of inflammatory responses on the risk of developing cardiac conduction disorders. METHODS: After the exclusion of participants failing to meet the inclusion criteria, 86,234 eligible participants (mean age: 50.57 ± 11.88 years) were included. The participants were divided into high-sensitivity C-reactive protein (hsCRP) ≤ 3 mg/L, and hsCRP > 3 mg/L groups based on hsCRP values. Multivariate Cox proportional hazard model was used to analyze the relationship between inflammatory responses and various cardiac conduction disorders. RESULTS: After adjusting for confounding factors, we observed that compared with the hsCRP ≤ 3 mg/L group, the hsCRP > 3 mg/L group exhibited increased risks of atrioventricular block (hazard ratio [HR]:1.64, 95%confidence interval [CI] 1.44-1.87) and left (HR:1.25, 95% CI 1.07-1.45) and right bundle branch block (HR:1.31, 95% CI 1.17-1.47). Moreover, the risk of various cardiac conduction disorders increased for every 1 standard deviation increase in log (hsCRP). The restricted cubic spline function confirmed a linear relationship between log (hsCRP) and the risk of developing cardiac conduction disorders (All nonlinearity P > 0.05). CONCLUSIONS: High hsCRP levels are an independent risk factor for cardiac conduction disorders, and hsCRP levels are dose-dependently associated with the risk of conduction disorders. Our study results may provide new strategies for preventing cardiac conduction disorders.


Assuntos
Proteína C-Reativa , Doenças Cardiovasculares , Humanos , Adulto , Pessoa de Meia-Idade , Proteína C-Reativa/análise , Estudos de Coortes , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA