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1.
Nano Lett ; 23(22): 10374-10382, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37921703

RESUMO

The development of new antimicrobial agents to treat infections caused by Gram-negative bacteria is of paramount importance due to increased antibiotic resistance worldwide. Herein, we show that a water-soluble porphyrin-cored hyperbranched conjugated polyelectrolyte (PorHP) exhibits high photodynamic bactericidal activity against the Gram-negative bacteria tested, including a multidrug-resistant (MDR) pathogen, while demonstrating low cytotoxicity toward mammalian cells. Comprehensive analyses reveal that the antimicrobial activity of PorHP proceeds via a multimodal mechanism by effective bacterial capsule shedding, strong bacterial outer membrane binding, and singlet oxygen generation. Through this multimodal antimicrobial mechanism, PorHP displays significant performance for Gram-negative bacteria with >99.9% photodynamic killing efficacy. Overall, PorHP shows great potential as an antimicrobial agent in fighting the growing threat of Gram-negative bacteria.


Assuntos
Anti-Infecciosos , Bactérias Gram-Negativas , Animais , Polieletrólitos/farmacologia , Anti-Infecciosos/farmacologia , Oxigênio Singlete , Antibacterianos/química , Testes de Sensibilidade Microbiana , Mamíferos/metabolismo
2.
Int J Environ Health Res ; : 1-15, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38153391

RESUMO

Existing evidence suggested that the risk of tuberculosis (TB) infection was associated to the variations in temperature and PM2.5. A total of 9,111 cases of TB were reported in Ningxia Hui Autonomous Region, China from 2013 to 2015 on a daily basis, and 57.2% of them were male. The TB risk was more prominent for a lower temperature in males (RR of 1.724, 95% CI: 1.241, 2.394), the aged over 64 years (RR of 2.241, 95% CI: 1.554, 3.231), and the high mobility occupation subpopulation (RR of 2.758, 95% CI: 1.745, 4.359). High concentration of PM2.5 showed a short-term effect and was only associated with an increased risk in the early stages of exposure for the female, and aged 36-64 years group. There were 15.06% (1370 cases) of cases of TB may be attributable to the temperature, and 2.94% (268 cases) may be attributable to the increase of PM2.5 exposures. Low temperatures may be associated with significantly increase in the risk of TB, and high PM2.5 concentrations have a short-term association on increasing the risk of TB. Strengthening the monitoring and regular prevention and control of high risk groups will provide scientific guidance to reduce the incidence of TB.

3.
Analyst ; 143(5): 1242-1249, 2018 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-29431796

RESUMO

A new turn-on near-infrared fluorescence probe (BDP) based on dibenzo[a,c]phenazine for superoxide anion detection with aggregation-induced emission properties as well as a desirable large Stokes shift was designed and synthesized. After BDP reacted with superoxide, the initial diphenyl-phosphinyl groups of BDP were cleaved, resulting in the production of the pyridinium modified fluorophore (BD) with near-infrared emission. The fluorescent sensor BDP has a high selectivity for superoxide anions over some other intracellular ROSs, reductants, metal ions and amino acids. When HepG2 cells undergo apoptosis and inflammation, BDP is a good probe to keep track of the endogenous superoxide anion level by confocal laser scanning microscopic imaging.


Assuntos
Corantes Fluorescentes , Fenazinas , Superóxidos/análise , Células Hep G2 , Humanos , Microscopia Confocal
4.
Med Sci Monit ; 23: 5735-5743, 2017 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-29197895

RESUMO

BACKGROUND The aim of this study was to screen the molecular targets of miR-34a in colorectal cancer (CRC) and construct the regulatory network, to gain more insights to the pathogenesis of CRC. MATERIAL AND METHODS The microarray data of CRC samples and normal samples (GSE4988), as well as CRC samples transformed with miR-34a and non-transfected CRC samples (GSE7754), were downloaded from the Gene Expression Omnibus (GEO) database. The differently expressed genes (DEGs) were identified via the LIMMA package in R language. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to identify significant Gene Ontology (GO) terms and pathways in DEGs. The targets of miR-34a were obtained via the miRWalk database, and then the overlaps between them were selected out to construct the regulatory network of miR-34a in CRC using the Cytoscape software. RESULTS A total of 392 DEGs were identified in CRC samples compared with normal samples, including 239 upregulated genes and 153 downregulated ones. These DEGs were enriched in 75 GO terms and one Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. At the same time, 332 DEGs (188 upregulated and 144 downregulated) were screened out between miR-34a transformed CRC and miR-34a non-transfected CRC samples and they were enriched in 20 GO terms and eight KEGG pathways. Six overlapped genes were identified in two DEGs groups. There were 1,668 targets of miR-34a obtained via the miRWalk database, among which 21 were identified differently expressed in miR-34a transformed CRC samples compared with miR-34a non-transfected CRC samples. Two regulatory networks of miR-34a in CRC within these two groups of overlapped genes were constructed respectively. CONCLUSIONS Pathways related to cell cycle, DNA replication, oocyte meiosis, and pyrimidine metabolism might play critical roles in the progression of CRC. Several genes such as SERPINE1, KLF4, SEMA4B, PPARG, CDC45, and KIAA0101 might be the targets of miR-34a and the potential therapeutic targets of CRC.


Assuntos
Neoplasias Colorretais/genética , MicroRNAs/genética , Neoplasias Colorretais/metabolismo , Biologia Computacional/métodos , Bases de Dados Genéticas , Progressão da Doença , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Fator 4 Semelhante a Kruppel , MicroRNAs/metabolismo
5.
Environ Microbiol ; 18(11): 3867-3883, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27105123

RESUMO

Cyanobacterial blooms have disrupted the efficient utilization of freshwater worldwide. A new freshwater bacterial strain with strong algicidal activity, GLY-2107, was isolated from Lake Taihu and identified as Aeromonas sp. It produced two algicidal compounds: 2107-A (3-benzyl-piperazine-2,5-dione) and 2107-B (3-methylindole). Both compounds exhibited potent algicidal activities against Microcystis aeruginosa, the dominant bloom-forming cyanobacterium in Lake Taihu. The EC50 values (concentration for 50% maximal effect) of 3-benzyl-piperazine-2,5-dione and 3-methylindole were 4.72 and 1.10 µg ml-1 respectively. Based on a thin-layer chromatography biosensor assay and ultra-performance liquid chromatography-coupled high resolution-tandem mass spectrometry (UPLC-HRMS/MS), the N-acyl homoserine lactone (AHL) profile of strain GLY-2107 was identified as two short side-chain AHLs: N-butyryl-homoserine lactone (C4-HSL) and N-hexanoyl-homoserine lactone (C6-HSL). The production of the two algicidal compounds was controlled by AHL-mediated quorum sensing (QS), and C4-HSL was the key QS signal for the algicidal activity of the strain GLY-2107. Moreover, 3-methylindole was found to be positively regulated by C4-HSL-mediated QS, whereas 3-benzyl-piperazine-2,5-dione might be negatively controlled by C4-HSL-mediated QS. This study suggests that a QS-regulated algicidal system may have potential use for the development of a novel control strategy for harmful cyanobacterial blooms.


Assuntos
4-Butirolactona/análogos & derivados , Aeromonas/fisiologia , Antibiose , Eutrofização , Microcystis/crescimento & desenvolvimento , Percepção de Quorum , 4-Butirolactona/metabolismo , Aeromonas/genética , Cromatografia em Camada Fina , Lagos/microbiologia
6.
Med Sci Monit ; 22: 310-5, 2016 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-26822491

RESUMO

BACKGROUND: The aim of this study was to investigate the roles of cytochrome P450 2C19 (CYP2C19) polymorphisms in primary open-angle glaucoma (POAG) susceptibility and individual responses to drug treatment. MATERIAL/METHODS: This case-control study consisted of 93 cases with POAG and 125 controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze CYP2C19 single-nucleotide polymorphisms (SNPs). After timolol treatment, patients were classified into side effect (SE) group and non-side effect (NSE) group. According to drug treatment responses, patients were divided into 3 groups: excellent group (Ex) (IOP ≥8 mm Hg); utility group (Ut) (5 0.05). Frequencies of extensive metabolizer phenotype and poor metabolizer phenotype or poor metabolizer phenotype and intermediate metabolizer phenotype were significantly different between the SE group and NSE group (both P<0.05). The distribution of intermediate metabolizer phenotype and extensive metabolizer phenotype were significantly different among Ex group, Ut group, and In group (all P<0.05). CONCLUSIONS: We found no evidence that CYP2C19 polymorphisms are associated with susceptibility to POAG. However, different CYP2C19 metabolizer phenotypes were identified and observed to have important effects on the individual differences in drug treatment response.


Assuntos
Citocromo P-450 CYP2C19/genética , Predisposição Genética para Doença , Glaucoma de Ângulo Aberto/tratamento farmacológico , Glaucoma de Ângulo Aberto/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Frequência do Gene/genética , Glaucoma de Ângulo Aberto/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Timolol/efeitos adversos , Timolol/uso terapêutico , Resultado do Tratamento , Adulto Jovem
7.
Appl Microbiol Biotechnol ; 99(12): 5227-36, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25683664

RESUMO

The acid tolerance is particularly important for bifidobacteria to function as probiotics because they usually encounter acidic environments in food products and gastrointestinal tract passage. In this study, two acid-resistant derivatives Bifidobacterium longum JDY1017dpH and Bifidobacterium breve BB8dpH, which displayed a stable acid-resistant phenotype, were generated. The relationship between acid tolerance and cell membrane was investigated by comparing the two acid-resistant derivatives and their parental strains grown in medium with and without Tween 80. The fold increase in acid tolerance of the two acid-resistant derivatives relative to their parental strains was much higher when cells were grown in medium with Tween 80 (10(4) ~ 10(5)-fold) than without Tween 80 (181- and 245-fold). Moreover, when cells were grown in medium with Tween 80, the two acid-resistant derivatives exhibited more C18:1 and cycC19:0, higher mean fatty acid chain length, lower membrane fluidity, and higher expression of cfa gene encoding cyclopropane fatty acid synthase than their parental strains. No significant differences in cell membrane were observed between the two acid-resistant derivatives and their parental strains when cells were grown in medium without Tween 80. The present study revealed that, when cells were grown in medium with Tween 80, the significant fold increase in acid tolerance of the two acid-resistant derivatives was mainly ascribed to the pronounced changes in cell membrane compared with their parental strains. Results presented here could provide a basis for developing new strategies of cell membrane modification to enhance acid tolerance in bifidobacteria.


Assuntos
Ácidos/metabolismo , Bifidobacterium/metabolismo , Membrana Celular/metabolismo , Polissorbatos/metabolismo , Bifidobacterium/química , Bifidobacterium/crescimento & desenvolvimento , Membrana Celular/química , Meios de Cultura/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Fluidez de Membrana
8.
Appl Microbiol Biotechnol ; 98(10): 4737-48, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24566920

RESUMO

Cyanobacterial blooms have become a serious problem in Lake Taihu during the last 20 years, and Microcystis aeruginosa and Synechococcus sp. are the two dominant species in cyanobacterial blooms of Lake Taihu. A freshwater bacterial strain, Shewanella sp. Lzh-2, with strong algicidal properties against harmful cyanobacteria was isolated from Lake Taihu. Two substances with algicidal activity secreted extracellularly by Shewanella sp. Lzh-2, S-2A and S-2B, were purified from the bacterial culture of strain Lzh-2 using ethyl acetate extraction, column chromatography, and high performance liquid chromatography (HPLC) in turn. The substances S-2A and S-2B were identified as hexahydropyrrolo[1,2-a]pyrazine-1,4-dione and 2, 3-indolinedione (isatin), respectively, based on liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), and hydrogen-nuclear magnetic resonance (H-NMR) analyses, making this the first report of their algicidal activity toward cyanobacteria. S-2A (hexahydropyrrolo[1,2-a]pyrazine-1,4-dione) had no algicidal effects against Synechococcus sp. BN60, but had a high level of algicidal activity against M. aeruginosa 9110. The LD50 value of S-2A against M. aeruginosa 9110 was 5.7 µg/ml. S-2B (2, 3-indolinedione) showed a potent algicidal effect against both M. aeruginosa 9110 and Synechococcus sp. BN60, and the LD50 value of S-2B against M. aeruginosa 9110 and Synechococcus sp. BN60 was 12.5 and 34.2 µg/ml, respectively. Obvious morphological changes in M. aeruginosa 9110 and Synechococcus sp. BN60 were observed after they were exposed to S-2A (or S-2B) for 24 h. Approximately, the algicidal activity, the concentration of S-2A and S-2B, and the cell density of Lzh-2 were positively related to each other during the cocultivation process. Overall, these findings increase our knowledge about algicidal substances secreted by algicidal bacteria and indicate that strain Lzh-2 and its two algicidal substances have the potential for use as a bio-agent in controlling cyanobacterial blooms in Lake Taihu.


Assuntos
Anti-Infecciosos/metabolismo , Indóis/metabolismo , Lagos/microbiologia , Pirazinas/metabolismo , Shewanella/isolamento & purificação , Shewanella/metabolismo , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Cromatografia Líquida , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Indóis/análise , Indóis/isolamento & purificação , Dose Letal Mediana , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Microcystis/efeitos dos fármacos , Microscopia , Dados de Sequência Molecular , Pirazinas/análise , Pirazinas/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Shewanella/classificação , Shewanella/genética , Synechococcus/efeitos dos fármacos
9.
Adv Mater ; 36(7): e2307940, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37921569

RESUMO

Selective and targeted removal of individual species or strains of bacteria from complex communities can be desirable over traditional and broadly acting antibiotics in several conditions. However, strategies that can detect and ablate bacteria with high specificity are emerging in recent years. Herein, a platform is reported that uses bacteria as a template to synthesize polymers containing guanidinium groups for self-selective depletion of specific pathogenic bacteria without disturbing microbial communities. Different from conventional antibiotics, repeated treatment of bacteria with the templated polymers does not evolve drug resistance mutants after 20 days of serial passaging. Especially, high in vivo therapeutic effectiveness of the templated polymers is achieved in E. coli- and P. aeruginosa-induced microbial peritonitis. The templated polymers have shown high selectivity in in vivo antimicrobial activity, which has excellent potential as systemic antimicrobials against bacterial infections.


Assuntos
Escherichia coli , Polímeros , Polímeros/uso terapêutico , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias
10.
Sci Rep ; 14(1): 13071, 2024 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844544

RESUMO

Knowledge, Attitude, and Practice (KAP) survey, as an effective measure tool, is of practical significance for identifying the susceptible population in high-incidence regions of tuberculosis (TB). We aim to identify the health education targeted susceptible population of TB and discuss the acting pathway of KAP in Ningxia. A multistage random sampling method was used to conduct a face-to-face questionnaire survey for residents. The latent class analysis (LCA) model was used to classify susceptible populations of TB, and the structural equation modeling (SEM) model was also employed to investigate the interaction mechanisms of KAP (mediation analysis). We further applied the ordered logistic regression model to explore the associated factors. A total of 973 residents were enrolled, 70.6% were male, aged from 16 to 89. The LCA analysis demonstrated that 3 categories of susceptible populations of TB ("overall good", "positive attitude" and "overall poor") have optimal goodness of fit (BIC = 7889.5, Entropy = 0.923). SEM model indicated that the attitude plays a significant mediation effect from knowledge to practice toward TB (an indirect effect of 0.038, and a direct effect of 0.138). The ordered logistic regression results found that age, sex, marital status, education level, occupation, family income, self-perceived health status, having a family member or friend with TB, and knowing the DOTS strategy were significantly associated with classifications of KAP level towards TB. Based on the LCA model, we accurately classified the susceptible population of TB into 3 groups with different degrees of KAP. We found that TB attitude plays a mediating role between knowledge and practice. Therefore, we should pay more attention and carry out targeted health education in the community to these populations with overall poor KAP towards TB, and develop effective strategies and measures to realize the End TB Plan.


Assuntos
Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Tuberculose , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , China/epidemiologia , Adolescente , Idoso , Tuberculose/epidemiologia , Adulto Jovem , Idoso de 80 Anos ou mais , Inquéritos e Questionários
11.
Rev Sci Instrum ; 95(6)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38832847

RESUMO

The core of electrostatic tomography (EST) is to solve the inverse problem, but the EST independent measurement data are much smaller than the value that needs to be reconstructed, resulting in a more serious inverse problem. This paper presents an improved ResNet-34 network (P-ResNet), which consists of an input layer, a residual feature extraction layer, and an output layer. The number of residual blocks is 3, 4, 4, and 3. After the second convolution in the main path of each residual block, a ReLU activation function is added to enhance the nonlinear expression ability of the network, and the generalization ability of the model is improved by introducing the L2 regularization loss function. A total of 15 930 sets of samples were simulated for the simulation test. After 200 rounds of iteration, the reconstruction results show that the network achieves high accuracy in EST image reconstruction tasks. In addition, the model is tested under different degrees of Gaussian white noise to verify its anti-noise ability. Compared with the traditional algorithms, the image correlation coefficients of this proposed model network are higher. In addition, this paper designs a small sensor to obtain the induced charge values through the principle of electrostatic induction. The reconstructed results obtained from the experimental data are consistent with the simulation results, which verifies the effectiveness and generalization ability of the proposed model.

12.
IEEE Trans Image Process ; 33: 2714-2729, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38557629

RESUMO

Billions of people share images from their daily lives on social media every day. However, their biometric information (e.g., fingerprints) could be easily stolen from these images. The threat of fingerprint leakage from social media has created a strong desire to anonymize shared images while maintaining image quality, since fingerprints act as a lifelong individual biometric password. To guard the fingerprint leakage, adversarial attack that involves adding imperceptible perturbations to fingerprint images have emerged as a feasible solution. However, existing works of this kind are either weak in black-box transferability or cause the images to have an unnatural appearance. Motivated by the visual perception hierarchy (i.e., high-level perception exploits model-shared semantics that transfer well across models while low-level perception extracts primitive stimuli that result in high visual sensitivity when a suspicious stimulus is provided), we propose FingerSafe, a hierarchical perceptual protective noise injection framework to address the above mentioned problems. For black-box transferability, we inject protective noises into the fingerprint orientation field to perturb the model-shared high-level semantics (i.e., fingerprint ridges). Considering visual naturalness, we suppress the low-level local contrast stimulus by regularizing the response of the Lateral Geniculate Nucleus. Our proposed FingerSafe is the first to provide feasible fingerprint protection in both digital (up to 94.12%) and realistic scenarios (Twitter and Facebook, up to 68.75%). Our code can be found at https://github.com/nlsde-safety-team/FingerSafe.


Assuntos
Mídias Sociais , Humanos , Dermatoglifia , Privacidade , Percepção Visual
13.
Adv Mater ; 36(21): e2313179, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38353598

RESUMO

Single-atom decorating of Pt emerges as a highly effective strategy to boost catalytic properties, which can trigger the most Pt active sites while blocking the smallest number of Pt atoms. However, the rational design and creation of high-density single-atoms on Pt surface remain as a huge challenge. Herein, a customized synthesis of surface-enriched single-Bi-atoms tailored Pt nanorings (SE-Bi1/Pt NRs) toward methanol oxidation is reported, which is guided by the density functional theory (DFT) calculations suggesting that a relatively higher density of Bi species on Pt surface can ensure a CO-free pathway and accelerate the kinetics of *HCOOH formation. Decorating Pt NRs with dense single-Bi-atoms is achieved by starting from PtBi intermetallic nanoplates (NPs) with intrinsically isolated Bi atoms and subsequent etching and annealing treatments. The SE-Bi1/Pt NRs exhibit a mass activity of 23.77 A mg-1 Pt toward methanol oxidation in alkaline electrolyte, which is 2.2 and 12.8 times higher than those of Pt-Bi NRs and Pt/C, respectively. This excellent activity endows the SE-Bi1/Pt NRs with a high likelihood to be used as a practical anodic electrocatalyst for direct methanol fuel cells (DMFCs) with high power density of 85.3 mW cm-2 and ultralow Pt loading of 0.39 mg cm-2.

14.
Front Public Health ; 11: 996694, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36844832

RESUMO

Background: Neonatal mortality rate (NMR), infant mortality rate (IMR), and child mortality rate (CMR) show a huge difference across countries, which has been posing challenges for public health policies and medical resource allocation. Methods: Bayesian spatiotemporal model is applied to assess the detailed spatiotemporal evolution of NMR, IMR, and CMR from a global perspective. Panel data from 185 countries from 1990 to 2019 are collected. Results: The continuously decreasing trend of NMR, IMR, and CMR indicated a great improvement in neonatal, infant, and child mortality worldwide. Further, huge differences in the NMR, IMR, and CMR still exist across countries. In addition, the gap of NMR, IMR, and CMR across the countries presented a widening trend from the perspective of dispersion degree and kernel densities. The spatiotemporal heterogeneities demonstrated that the decline degree among these three indicators could be observed as CMR > IMR > NMR. Countries such as Brazil, Sweden, Libya, Myanmar, Thailand, Uzbekistan, Greece, and Zimbabwe showed the highest values of b1i , indicating a weaker downward trend compared to the overall downward trend in the world. Conclusions: This study revealed the spatiotemporal patterns and trends in the levels and improvement of NMR, IMR, and CMR across countries. Further, NMR, IMR, and CMR show a continuously decreasing trend, but the differences in improvement degree present a widening trend across countries. This study provides further implications for policy in newborns, infants, and children's health to reduce health inequality worldwide.


Assuntos
Mortalidade da Criança , Disparidades nos Níveis de Saúde , Criança , Lactente , Humanos , Recém-Nascido , Teorema de Bayes , Mortalidade Infantil , Política Pública
15.
Rev Sci Instrum ; 94(3): 034706, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37012813

RESUMO

Electromagnetic tomography (EMT) is used to create tomographic images of the electrical properties of conducting material based on electromagnetic measurements from coils evenly distributed around the imaging region. EMT is widely used in industrial and biomedical fields for which it offers the advantages of being non-contact, fast, and non-radiative. Most EMT measurement systems are implemented with commercial instruments, such as impedance analyzers and lock-in amplifiers, which are bulky and inconvenient for portable detection devices. In order to improve the portability and extensibility, a purpose-built flexible and modularized EMT system is presented in this paper. The hardware system consists of six parts: the sensor array, signal conditioning module, lower computer module, data acquisition module, excitation signal module, and the upper computer. The complexity of the EMT system is reduced by a modularized design. The sensitivity matrix is calculated by the perturbation method. The split Bregman algorithm is applied to solve the L1 norm regularization problem. The effectiveness and advantages of the proposed method are verified by numerical simulations. The average signal to noise ratio of the EMT system is 48 dB. Experimental results verified that the reconstructed images can show the number and positions of the imaging objects, demonstrating the feasibility and effectiveness of the novel imaging system design.

16.
Int J Public Health ; 68: 1605345, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37234944

RESUMO

Objectives: It's evident that women have a longer life expectancy than men. This study investigates the spatiotemporal trends of gender gaps in life expectancy (GGLE). It demonstrates the spatiotemporal difference of the influence factors of population-weighted air pollution (pwPM2.5) and urbanization on GGLE. Methods: Panel data on GGLE and influencing factors from 134 countries from 1960 to 2018 are collected. The Bayesian spatiotemporal model is performed. Results: The results show an obvious spatial heterogeneity worldwide with a continuously increasing trend of GGLE. Bayesian spatiotemporal regression reveals a significant positive relationship between pwPM2.5, urbanization, and GGLE with the spatial random effects. Further, the regression coefficients present obvious geographic disparities across space worldwide. Conclusion: In sum, social-economic development and air quality improvement should be considered comprehensively in global policy to make a fair chance for both genders to maximize their health gains.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Feminino , Masculino , Poluentes Atmosféricos/análise , Urbanização , Teorema de Bayes , Fatores Sexuais , Poluição do Ar/análise , Expectativa de Vida
17.
Front Pediatr ; 11: 1112121, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37051430

RESUMO

Background: Deviations from the regular pattern of growth and development could lead to early childhood diseases, suggesting the importance of evaluating early brain development. Through this study, we aimed to explore the changing patterns of white matter and gray matter during neonatal brain development using diffusion kurtosis imaging (DKI). Materials and methods: In total, 42 full-term neonates (within 28 days of birth) underwent conventional brain magnetic resonance imaging (MRI) and DKI. The DKI metrics (including kurtosis parameters and diffusion parameters) of white matter and deep gray matter were measured. DKI metrics from the different regions of interest (ROIs) were evaluated using the Kruskal-Wallis test and Bonferroni method. Spearman rank correlation analysis of the DKI metrics was conducted, and the age at the time of brain MRI acquisition was calculated. The subjects were divided into three groups according to their age at the time of brain MRI acquisition: the first group, neonates aged ≤7 days; the second group, neonates aged 8-14 days; and the third group, neonates aged 15-28 days. The rate of change in DKI metrics relative to the first group was computed. Results: The mean kurtosis (MK), axial kurtosis (Ka), radial kurtosis (Kr), and fractional anisotropy (FA) values showed positive correlations, whereas mean diffusion (MD), axial diffusion (Da), and radial diffusion (Dr) values showed negative correlations with the age at the time of brain MRI acquisition. The absolute correlation coefficients between MK values of almost all ROIs (except genu of the corpus callosum and frontal white matter) and the age at the time of brain MRI acquisition were greater than other metrics. The kurtosis parameters and FA values of central white matter were significantly higher than that of peripheral white matter, whereas the MD and Dr values were significantly lower than that of peripheral white matter. The MK value of the posterior limb of the internal capsule was the highest among the white matter areas. The FA value of the splenium of the corpus callosum was significantly higher than that of the other white matter areas. The kurtosis parameters and FA values of globus pallidus and thalamus were significantly higher than those of the caudate nucleus and putamen, whereas the Da and Dr values of globus pallidus and thalamus were significantly lower than those of the caudate nucleus and putamen. The relative change rates of kurtosis parameters and FA values of all ROIs were greater than those of MD, Da, and Dr values. The amplitude of MK values of almost all ROIs (except for the genu of the corpus callosum and central white matter of the centrum semiovale level) was greater than that of other metrics. The relative change rates of the Kr values of most ROIs were greater than those of the Ka value, and the relative change rates of the Dr values of most ROIs were greater than those of the Da value. Conclusion: DKI parameters showed potential advantages in detecting the changes in brain microstructure during neonatal brain development.

18.
IEEE Trans Pattern Anal Mach Intell ; 45(10): 11689-11706, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37141057

RESUMO

Generative data-free quantization emerges as a practical compression approach that quantizes deep neural networks to low bit-width without accessing the real data. This approach generates data utilizing batch normalization (BN) statistics of the full-precision networks to quantize the networks. However, it always faces the serious challenges of accuracy degradation in practice. We first give a theoretical analysis that the diversity of synthetic samples is crucial for the data-free quantization, while in existing approaches, the synthetic data completely constrained by BN statistics experimentally exhibit severe homogenization at distribution and sample levels. This paper presents a generic Diverse Sample Generation (DSG) scheme for the generative data-free quantization, to mitigate detrimental homogenization. We first slack the statistics alignment for features in the BN layer to relax the distribution constraint. Then, we strengthen the loss impact of the specific BN layers for different samples and inhibit the correlation among samples in the generation process, to diversify samples from the statistical and spatial perspectives, respectively. Comprehensive experiments show that for large-scale image classification tasks, our DSG can consistently quantization performance on different neural architectures, especially under ultra-low bit-width. And data diversification caused by our DSG brings a general gain to various quantization-aware training and post-training quantization approaches, demonstrating its generality and effectiveness.

19.
IEEE Trans Cybern ; 53(8): 5226-5239, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35976829

RESUMO

Recently, deep neural networks have achieved promising performance for in-filling large missing regions in image inpainting tasks. They have usually adopted the standard convolutional architecture over the corrupted image, leading to meaningless contents, such as color discrepancy, blur, and other artifacts. Moreover, most inpainting approaches cannot handle well the case of a large contiguous missing area. To address these problems, we propose a generic inpainting framework capable of handling incomplete images with both contiguous and discontiguous large missing areas. We pose this in an adversarial manner, deploying regionwise operations in both the generator and discriminator to separately handle the different types of regions, namely, existing regions and missing ones. Moreover, a correlation loss is introduced to capture the nonlocal correlations between different patches, and thus, guide the generator to obtain more information during inference. With the help of regionwise generative adversarial mechanism, our framework can restore semantically reasonable and visually realistic images for both discontiguous and contiguous large missing areas. Extensive experiments on three widely used datasets for image inpainting task have been conducted, and both qualitative and quantitative experimental results demonstrate that the proposed model significantly outperforms the state-of-the-art approaches, on the large contiguous and discontiguous missing areas.

20.
Huan Jing Ke Xue ; 44(7): 3933-3944, 2023 Jul 08.
Artigo em Zh | MEDLINE | ID: mdl-37438292

RESUMO

The Tuojiang River and Fujiang River, two important tributaries of the upper reaches of the Yangtze River, have serious water pollution problems, among which nitrogen (N) and phosphorus (P) are the most important pollutants. Therefore, the aim of this study was to identify the influencing factors of water quality in different spaces and provide a scientific basis for the prevention and control of surface water pollution in the upper reaches of the Yangtze River and its tributaries. Water samples of trunk and tributaries in the Tuojiang River and Fujiang River were collected, and the spatial distribution characteristics of water N and P were analyzed. The results showed that the Tuojiang River and Fujiang River showed serious pollution of total nitrogen (TN), with a water quality worse Ⅴ-section proportion as high as 94% and 50%, respectively. Both rivers showed that TN and TP concentrations in the tributaries were higher than those in the main stream. For both rivers, total phosphorus (TP), with moderate pollution, was mainly concentrated in Ⅱ, Ⅲ, and Ⅳ class water quality, whereas the P pollution was more serious for the Fujiang River compared to that of the Fujiang River. For the Tuojiang River, nitrate nitrogen (NN) concentration from upstream to downstream showed a trend of decreasing after the first increase, with the maximum concentration of ammonium nitrogen (AN) exhibiting at the upstream site. In particular, TP concentration increased significantly after rivers flowed through a city. For the Fujiang River trunk stream, TN and NN concentration exhibited a gradually increasing trend from the middle to lower reaches. Generally, our study revealed that TN, TP, and NN in the rivers were affected by water pH and water temperature (T). Therefore, the control of N and P pollution in rivers should pay attention to the influence of water environmental factors.


Assuntos
Poluentes Ambientais , Nitratos , Nitrogênio , Nutrientes , Fósforo , Poluição da Água
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