Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 19(4): e0301910, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635672

RESUMO

With the increasing demand for electricity, microgrid systems are facing issues such as insufficient backup capacity, frequent load switching, and frequent malfunctions, making research on microgrid resilience crucial, especially to improve system power supply reliability. This paper proposes a method for analyzing the resilience metric of new energy grid-connected microgrid system, and proposes optimization strategies to improve resilience. Firstly, a measurement method for the resilience of the microgrid system is established based on the operating characteristics of the system components. Secondly, the sensitivity relationship between system resilience and parameters is established, and an optimization model for resilience improvement strategies of microgrid systems based on parameter sensitivity is constructed. Finally, simulation verification is conducted based on the IEEE 37-node microgrid system. The results show that the proposed measurement method can scientifically and reasonably measure the resilience of the microgrid system, and the resilience improvement strategy significantly improves the operational resilience, verifying the effectiveness and robustness of the proposed analysis method.


Assuntos
Resiliência Psicológica , Reprodutibilidade dos Testes , Simulação por Computador , Sistemas Computacionais , Fontes de Energia Elétrica
2.
J Ethnopharmacol ; 329: 118130, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38565407

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Psoraleae Fructus (Bu Gu Zhi) is the fruit of Psoralea corylifolia L. (PCL) and has been used for centuries in traditional Chinese medicine formulas to treat osteoporosis (OP). A new drug called "BX" has been developed from PCL, but its mechanism for treating OP is not yet fully understood. AIM OF THE STUDY: To explore the mechanism of action of BX in the treatment of ovariectomy-induced OP based function-oriented multi-omics analysis of gut microbiota (GM) and metabolites. MATERIALS AND METHODS: C57BL/6 mice were bilaterally ovariectomized to replicate the OP model. The therapeutic efficacy of BX was evaluated by bone parameters (BMD, BV/TV, Tb.N, Tb.Sp), hematoxylin and eosin (H&E) staining results, and determination of bone formation markers procollagen type Ⅰ amino-terminal peptide (PⅠNP) and bone-specific alkaline phosphatase (BALP). Serum and fecal metabolomics and high-throughput 16S rDNA sequencing were performed to evaluate effects on endogenous metabolites and GM. In addition, an enzyme-based functional correlation algorithm (EBFC) algorithm was used to investigate functional correlations between GM and metabolites. RESULTS: BX improved OP in OVX mice by increasing BMD, BV/TV, serum PⅠNP, BALP, and improving Tb.N and Tb.Sp. A total of 59 differential metabolites were identified, and 9 metabolic pathways, including arachidonic acid metabolism, glycerophospholipid metabolism, purine metabolism, and tryptophan metabolism, were found to be involved in the progression of OP. EBFC analysis results revealed that the enzymes related to purine and tryptophan metabolism, which are from Lachnospiraceae_NK4A136_group, Blautia, Rs-E47_termite_group, UCG-009, and Clostridia_UCG-014, were identified as the intrinsic link between GM and metabolites. CONCLUSIONS: The regulation of GM and restoration of metabolic disorders may be the mechanisms of action of BX in alleviating OP. This research provides insights into the function-oriented mechanism discovery of traditional Chinese medicine in the treatment of OP.

3.
Sci Rep ; 14(1): 9340, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654052

RESUMO

High voltage circuit breakers are one of the core equipment in power system operation, and the voiceprint signals generated during operation contain extremely rich information. This paper proposes a fault identification method for high voltage circuit breakers based on voiceprint information data. Firstly, based on the developed voiceprint information data acquisition device, the voiceprint information of a certain high voltage circuit breaker is obtained; Secondly, an improved S-transform is proposed in the article, which generates an amplitude matrix based on the S-transform of voiceprint information; Then, through the matrix Singular value decomposition method, the fault feature quantity of voiceprint information is extracted from the time-frequency angle, and the diagnosis system of the support vector machine model is established, and the system is trained to realize the fault identification of the high-voltage circuit breaker; Finally, through experimental simulation calculations, it was shown that the accuracy of the proposed fault identification method in different operating conditions reached 92.6%, verifying the good accuracy and robustness of the proposed method and equipment.

4.
EJNMMI Phys ; 11(1): 40, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662044

RESUMO

PURPOSE: This study aimed to evaluate the feasibility of 11C-CFT PET brain imaging in Parkinson's Disease using a total-body PET/CT scanner and explore the optimal scan duration to guide the clinical practice. METHODS: Thirty-two patients with Parkinson's disease (PD) performing 11C-CFT PET/CT brain imaging using a total-body PET/CT scanner were retrospectively enrolled. The PET data acquired over a period of 900 s were reconstructed into groups of different durations: 900-s, 720-s, 600-s, 480-s, 300-s, 180-s, 120-s, 60-s, and 30-s (G900 to G30). The subjective image quality analysis was performed using 5-point scales. Semi-quantitative measurements were analyzed by SUVmean and dopamine transporter (DAT) binding of key brain regions implicated in PD, including the caudate nucleus and putamen. The full-time images (G900) were served as reference. RESULTS: The overall G900, G720, and G600 image quality scores were 5.0 ± 0.0, 5.0 ± 0.0, and 4.9 ± 0.3 points, respectively, and there was no significant difference among these groups (P > 0.05). A significant decrease in these scores at durations shorter than 600 s was observed when compared to G900 images (P < 0.05). However, all G300 image quality was clinically acceptable (≥ 3 points). As the scan duration reduced, the SUVmean and DAT binding of caudate nucleus and putamen decreased progressively, while there were no statistically significant variations in the SUVmean of the background among the different groups. Moreover, the changes in the lesion DAT binding (ΔDAT-binding) between the full-time reference G900 image and other reconstructed group G720 to G30 images generally increased along with the reduced scan time. CONCLUSION: Sufficient image quality and lesion conspicuity could be achieved at 600-s scan duration for 11C-CFT PET brain imaging in PD assessment using a total-body PET/CT scanner, while the image quality of G300 was acceptable to meet clinical diagnosis, contributing to improve patient compliance and throughput of PET brain imaging.

5.
J Cardiothorac Surg ; 19(1): 133, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491390

RESUMO

BACKGROUND: Aortic intramural hematoma (IMH) is one of the typical entities of acute aortic syndrome and probably accounts for 5-25% of all cases. The ulcer-like projections (ULP), which are described as a focal, blood-filled pouch protruding into the hematoma of the aortic wall, are regarded as one of the high-risk imaging features of IMH and may cause initial medical treatment failure and death. CASE PRESENTATION: We present a case report of an acute type B IMH patient with impaired renal function and newly developed ULP in the acute phase. The 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MR) was performed to evaluate the condition of aortic hematoma. The 18F-FDG focal uptake along the aortic wall of the hematoma was normal compared to the background (SUVmax 2.17; SUVSVC 1.6; TBR 1.35). We considered the IMH stable in such cases and opted for medical treatment and watchful observation. Six months after discharge, the patient's recovery was satisfactory, and aortic remodeling was ideal. CONCLUSIONS: The 18F-FDG PET/MR is a novel tool to evaluate the risk of IMH patients and thus provides information for therapy selection.


Assuntos
Doenças da Aorta , Fluordesoxiglucose F18 , Humanos , Tomografia Computadorizada por Raios X/métodos , Tomografia por Emissão de Pósitrons/métodos , Doenças da Aorta/diagnóstico por imagem , Imageamento por Ressonância Magnética , Hematoma/diagnóstico por imagem , Hematoma/terapia , Estudos Retrospectivos
6.
Ann Hematol ; 102(10): 2779-2789, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37530853

RESUMO

This study aimed to clarify the clinical and prognostic role of body composition and metabolic parameters extracted from baseline 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma (DLBCL). We retrospectively collected the clinicopathological and 18F-FDG PET/CT parameters of 181 DLBCL patients. The indexes of skeletal muscle, subcutaneous adipose tissue, and visceral adipose tissue were calculated using the area measured at the 3rd lumbar level normalized for height. Additionally, the metabolic activity of corresponding muscle and adipose tissue, and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of all lesions were measured. Survival endpoints included progression-free survival (PFS) and overall survival (OS). We identified 75 (41.4%) patients with low skeletal muscle index (sarcopenia), presenting risk factors including male, high ß2-microglobulin, low BMI, high visceral adipose tissue index, low SUVmax of skeletal muscle, and high SUVmax of visceral adipose tissue. Male, low BMI, low visceral adipose tissue index, and high SUVmax of subcutaneous adipose tissue were risk factors for low subcutaneous adipose tissue index diagnosed in 105 (58.0%) patients. In total, 132 (79.2%) patients represented low visceral adipose tissue index, associated with younger age, B symptoms, and low BMI. Eastern Cooperative Oncology Group (ECOG) status, sarcopenia, and visceral adipose tissue index were found independently predictive of PFS and OS, while ß2-microglobulin was independently predictive of OS. In conclusion, body composition indexes were correlated with both clinical characteristics and 18F-FDG PET/CT metabolic parameters, significantly impacting survival, such that sarcopenia and high visceral adipose tissue index were powerful predictors of poor DLBCL outcomes.


Assuntos
Linfoma Difuso de Grandes Células B , Sarcopenia , Humanos , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Estudos Retrospectivos , Sarcopenia/diagnóstico por imagem , Sarcopenia/etiologia , Prognóstico , Composição Corporal , Carga Tumoral , Compostos Radiofarmacêuticos
7.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(3): 1711-2, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-25242179

RESUMO

In the present study, we determined the complete nucleotide sequence of the mitochondrial (mt) genome of Chinese hare, Lepus sinensis (Leporidae: Lepus) by using polymerase chain reaction (PCR) technique. The entire mtDNA sequence is 17438 nucleotides long and contains 13 protein-coding genes, 2 ribosomal tRNA 22 transfer RNA gens and one long non-coding region known as the control region. The mt gene arrangement of L. sinensis is identical to those typical for vertebrates.


Assuntos
DNA Mitocondrial/genética , Lebres/genética , Animais , Composição de Bases/genética , Pareamento de Bases/genética , Sequência de Bases , Genes Mitocondriais , Genoma Mitocondrial
8.
Mitochondrial DNA ; 25(5): 359-60, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23815324

RESUMO

Emberiza rutila is a passerine bird of eastern Asia which belongs to the genus Emberiza in the bunting family Emberizidae. The complete mitochondrial genome of E. rutila was obtained for the first time in this study. The circular genome (16,803 bp in length) consists of 37 typical animal mitochondrial genes (13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes) and 1 control region. Overall base composition of the complete mitochondrial DNA was 30% A, 22.8% T, 32.8% C and 14.3% G. Except for 8 tRNA genes and ND6 gene, the relative position and orientation of all the genes were identical to those of most vertebrates.


Assuntos
Genoma Mitocondrial , Passeriformes/genética , Análise de Sequência de DNA/métodos , Animais , Composição de Bases , Genes Mitocondriais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...