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Sunlight exposure is known to affect mood, learning, and cognition. However, the molecular and cellular mechanisms remain elusive. Here, we show that moderate UV exposure elevated blood urocanic acid (UCA), which then crossed the blood-brain barrier. Single-cell mass spectrometry and isotopic labeling revealed a novel intra-neuronal metabolic pathway converting UCA to glutamate (GLU) after UV exposure. This UV-triggered GLU synthesis promoted its packaging into synaptic vesicles and its release at glutamatergic terminals in the motor cortex and hippocampus. Related behaviors, like rotarod learning and object recognition memory, were enhanced after UV exposure. All UV-induced metabolic, electrophysiological, and behavioral effects could be reproduced by the intravenous injection of UCA and diminished by the application of inhibitor or short hairpin RNA (shRNA) against urocanase, an enzyme critical for the conversion of UCA to GLU. These findings reveal a new GLU biosynthetic pathway, which could contribute to some of the sunlight-induced neurobehavioral changes.
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Encéfalo/efeitos da radiação , Ácido Glutâmico/biossíntese , Aprendizagem/efeitos da radiação , Memória/efeitos da radiação , Raios Ultravioleta , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Cromatografia Líquida de Alta Pressão , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/fisiologia , Técnicas de Patch-Clamp , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espectrometria de Massas em Tandem , Urocanato Hidratase/antagonistas & inibidores , Urocanato Hidratase/genética , Urocanato Hidratase/metabolismo , Ácido Urocânico/sangue , Ácido Urocânico/metabolismoRESUMO
Due to their programmable stimuli-responsiveness, excellent biocompatibility, and water-rich and soft structures similar to biological tissues, smart DNA hydrogels hold great promise for biosensing and biomedical applications. However, most DNA hydrogels developed to date are composed of randomly oriented and isotropic polymer networks, and the resulting slow response to biotargets and lack of anisotropic properties similar to those of biological tissues have limited their extensive applications. Herein, anisotropic DNA hydrogels consisting of unidirectional void channels internally oriented up to macroscopic length scales were constructed by a directional cryopolymerization method, as exemplified by a DNA-incorporated covalently cross-linked DNA cryogel and a DNA duplex structure noncovalently cross-linked DNA cryogel. Results showed that the formation of unidirectional channels significantly improved the responsiveness of the gel matrix to biomacromolecular substances and further endowed the DNA cryogels with anisotropic properties, including anisotropic mechanical properties, anisotropic swelling/shrinking behaviors, and anisotropic responsiveness to specific biotargets. Moreover, the abundant oriented and long macroporous channels in the gel matrix facilitated the migration of cells, and through the introduction of aptamer structures and thermosensitive polymers, an anisotropic DNA cryogel-based platform was further constructed to achieve the highly efficient capture and release of specific cells. These anisotropic DNA hydrogels may provide new opportunities for the development of anisotropic separation and biosensing systems.
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Criogéis , Hidrogéis , Criogéis/química , Hidrogéis/química , Polímeros/química , DNARESUMO
Stimuli-responsive DNA hydrogels have shown great potential in sensing applications due to their attractive properties such as programmable target responsiveness, excellent biocompatibility, and biodegradability. In contrast to the extensively developed DNA hydrogel sensing systems based on the stimuli-responsive hydrogel-to-solution phase transition of the hydrogel matrix, the quantitative sensing application of DNA hydrogels exhibiting smart shape deformations has rarely been explored. Moreover, bulk DNA hydrogel-based sensing systems also suffer from high material cost and slow response. Herein, free-standing bilayer polyacrylamide/DNA hybrid hydrogel films with programmable responsive properties directed by the sequence of functional DNA units have been constructed. Compared with bulk DNA hydrogels, these DNA hydrogel films with a thickness at the micrometer scale not only greatly reduce the consumption of DNA materials but also facilitate the mass transfer of biomacromolecular substances within the hydrogel network, thus favoring their sensing applications. Therefore, a target-responsive smart DNA hydrogel film-based sensor system is further demonstrated based on the large amplitude macroscopic shape deformation of the film as a visual signal readout. As a proof of concept, Pb2+ or UO22+ ion-responsive DNA units were introduced into the active layer of the bilayer hydrogel films. In the presence of Pb2+ or UO22+ ions, the occurrence of a cleavage reaction within the DNA units leads to the release of DNA segments from the hydrogel film, inducing a dramatic shape deformation of the film, and thus sensing of Pb2+ or UO22+ ions with high specificity is achieved based on measuring the bending angle changes of these smart free-standing films. These smart DNA hydrogel film sensors with target-programmable responsiveness, simple operation, and ease of storage may hold promise for future rapid on-site testing applications.
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Resinas Acrílicas , Hidrogéis , Chumbo , Metilgalactosídeos , DNA , ÍonsRESUMO
As a fundamental product of CO2 conversion through two-electron transfer, CO is used to produce numerous chemicals and fuels with high efficiency, which has broad application prospects. In this work, it has successfully optimized catalytic activity by fabricating an electrocatalyst featuring crystalline-amorphous CoO-InOx interfaces, thereby significantly expediting CO production. The 1.21%CoO-InOx consists of randomly dispersed CoO crystalline particles among amorphous InOx nanoribbons. In contrast to the same-phase structure, the unique CoO-InOx heterostructure provides plentiful reactive crystalline-amorphous interfacial sites. The Faradaic efficiency of CO (FECO) can reach up to 95.67% with a current density of 61.72 mA cm-2 in a typical H-cell using MeCN containing 0.5 M 1-Butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) as the electrolyte. Comprehensive experiments indicate that CoO-InOx interfaces with optimization of charge transfer enhance the double-layer capacitance and CO2 adsorption capacity. Theoretical calculations further reveal that the regulating of the electronic structure at interfacial sites not only optimizes the Gibbs free energy of *COOH intermediate formation but also inhibits HER, resulting in high selectivity toward CO.
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In wheat (Triticum aestivum L.), breeding efforts have focused intensively on improving grain yield and quality. For quality, the content and composition of seed storage proteins (SSPs) determine the elasticity of wheat dough and flour processing quality. Moreover, starch levels in seeds are associated with yield. However, little is known about the mechanisms that coordinate SSP and starch accumulation in wheat. In this study, we explored the role of the endosperm-specific NAC transcription factor TaNAC019 in coordinating SSP and starch accumulation. TaNAC019 binds to the promoters of TaGlu-1 loci, encoding high molecular weight glutenin (HMW-GS), and of starch metabolism genes. Triple knock-out mutants of all three TaNAC019 homoeologs exhibited reduced transcript levels for all SSP types and genes involved in starch metabolism, leading to lower gluten and starch contents, and in flour processing quality parameters. TaNAC019 directly activated the expression of HMW-GS genes by binding to a specific motif in their promoters and interacting with the TaGlu-1 regulator TaGAMyb. TaNAC019 also indirectly regulated the expression of TaSPA, an ortholog of maize Opaque2 that activates SSP accumulation. Therefore, TaNAC019 regulation of starch- and SSP-related genes has key roles in wheat grain quality. Finally, we identified an elite allele (TaNAC019-BI) associated with flour processing quality, providing a candidate gene for breeding wheat with improved quality.
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Endosperma/metabolismo , Proteínas de Plantas/metabolismo , Amido/metabolismo , Fatores de Transcrição/metabolismo , Alelos , Endosperma/genética , Glutens/genética , Glutens/metabolismo , Proteínas de Plantas/genética , Amido/genética , Fatores de Transcrição/genética , Triticum/genética , Triticum/metabolismoRESUMO
Electrochemical CO2 reduction is a promising method for converting atmospheric CO2 into valuable low-carbon chemicals. In this study, a crystalline cadmium sulfide/amorphous cadmium hydroxide composite was successfully deposited on the carbon paper substrate surface by in-situ chemical bath deposition (named as c-CdS/a-Cd(OH)2/CP electrodes) for the efficient electrochemical CO2 reduction to produce CO. The c-CdS/a-Cd(OH)2/CP electrode exhibited high CO Faradaic efficiencies (>90 %) under a wide potential window of 1.0â V, with the highest value reaching ~100 % at the applied potential ranging from -2.16â V to -2.46â V vs. ferrocene/ferrocenium (Fc/Fc+), superior to the crystalline counterpart c-CdS/CP and c-CdS/c-Cd(OH)2@CP electrodes. Meanwhile, the CO partial current density reached up to 154.7â mA cm-2 at -2.76â V vs. Fc/Fc+ on the c-CdS/a-Cd(OH)2/CP electrode. The excellent performance of this electrode was mainly ascribed to its special three-dimensional structure and the introduction of a-Cd(OH)2. These structures could provide more active sites, accelerate the charge transfer, and enhance adsorption of *COOH intermediates, thereby improving the CO selectivity. Moreover, the electrolytes consisting of 1-butyl-3-methylimidazolium tetrafluoroborate and acetonitrile also enhanced the reaction kinetics of electrochemical CO2 reduction to CO.
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BACKGROUNDS: Lymphoplasmacyte-rich meningioma(LPM) is a rare subtype of meningioma with a low degree of malignancy and an overall preferable prognosis. The purpose of this article is to increase the understanding of the disease, reduce misdiagnosis, and improve prognosis. METHODS: A search was conducted in the PubMed database for English articles published from 1993 to 2023. The keywords were "lymphoplasmacyte-rich (all fields) and meningioma (all fields) and English (lang)" and "lymphoplasmacyte-rich meningioma (title/abstract) and English (lang)".We further analyzed the clinical manifestations, imaging manifestations, pathological features, treatment strategies, and prognosis of LPM.The possible prognostic indicators were analyzed by the log-rank test and Pearson's chi-squared test. RESULTS: Fourteen reports with 95 LPM patients were included in this report, including 47 males and 48 females who were diagnosed between the ages of 9 and 79, with an average age of 45 years. The most common clinical manifestations are headache and limb movement disorders. In most cases, the tumor occurred on the convex portion of the brain. All tumors showed significant enhancement, with homogeneous enhancement being more common, and most patients showed peritumoral edema. Postoperative pathological EMA, LCA, and vimentin positivity were helpful for the final diagnosis of the patient. Log-rank tests showed a correlation between complete resection and better prognosis and recurrence. CONCLUSION: There is a lack of significant differences in the clinical symptoms and imaging manifestations of LPM compared to other diseases that need to be differentiated, and a clear diagnosis requires pathological examination. After standardized surgical treatment, the recurrence rate and mortality rate of LPM are both low. Complete surgical resection of tumors is associated with a better prognosis and lower recurrence rate.
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Neoplasias Meníngeas , Meningioma , Feminino , Masculino , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Meningioma/diagnóstico , Meningioma/epidemiologia , Prognóstico , Encéfalo , Bases de Dados Factuais , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/epidemiologiaRESUMO
Stimuli-responsive upconversion nanoparticle (UCNP)-poly-N-isopropylacrylamide (pNIPAM)/DNA core-shell microgels with tunable sizes and programmable functions have been prepared. Thanks to the near-infrared (NIR)-responsive UCNP cores and thermosensitive polymeric shells, functional DNA-incorporated microgels with high DNA activity and loading efficiency are obtained, and the activity of the loaded DNA structures can be smartly regulated by NIR illumination and temperature simultaneously.
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BACKGROUND: The MACF1 gene, found on chromosome 1p34.3, is vital for controlling cytoskeleton dynamics, cell movement, growth, and differentiation. It consists of 101 exons, spanning over 270 kb. The 16p13.11 microduplication syndrome results from the duplication of 16p13.11 chromosome copies and is associated with various neurodevelopmental and physiological abnormalities. Both MACF1 and 16p13.11 microduplication have significant impacts on neural development, potentially leading to nerve damage or neurological diseases. This study presents a unique case of a patient simultaneously experiencing a de novo MACF1 mutation and a hereditary 16p13.11 microduplication, which has not been reported previously. CASE PRESENTATION: In this report, we describe a Chinese preterm newborn girl exhibiting the typical characteristics of 16.13.11 microduplication syndrome. These features include developmental delay, respiratory issues, feeding problems, muscle weakness, excessive joint movement, and multiple congenital abnormalities. Through whole-exome sequencing, we identified a disease-causing mutation in the MACF1 gene (c.15266T > C / p. Met5089Thr). Additionally, after microarray analysis, we confirmed the presence of a 16p13.11 microduplication (chr16:14,916,289 - 16,315,688), which was inherited from the mother. CONCLUSIONS: The patient's clinical presentation, marked by muscle weakness and multiple birth defects, may be attributed to both the de novo MACF1 mutation and the 16p13.11 duplication, which could have further amplified her severe symptoms. Genetic testing for individuals with complex clinical manifestations can offer valuable insights for diagnosis and serve as a reference for genetic counseling for both patients and their families.
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Anormalidades Múltiplas , Cromossomos Humanos Par 16 , Hipotonia Muscular , Humanos , Feminino , Recém-Nascido , Hipotonia Muscular/genética , Cromossomos Humanos Par 16/genética , Anormalidades Múltiplas/genética , Recém-Nascido Prematuro , Duplicação Cromossômica , Mutação , Proteínas dos Microfilamentos/genéticaRESUMO
In order to improve the prediction accuracy of the sound quality of vehicle interior noise, a novel sound quality prediction model was proposed based on the physiological response predicted metrics, i.e., loudness, sharpness, and roughness. First, a human-ear sound transmission model was constructed by combining the outer and middle ear finite element model with the cochlear transmission line model. This model converted external input noise into cochlear basilar membrane response. Second, the physiological perception models of loudness, sharpness, and roughness were constructed by transforming the basilar membrane response into sound perception related to neuronal firing. Finally, taking the calculated loudness, sharpness, and roughness of the physiological model and the subjective evaluation values of vehicle interior noise as the parameters, a sound quality prediction model was constructed by TabNet model. The results demonstrate that the loudness, sharpness, and roughness computed by the human-ear physiological model exhibit a stronger correlation with the subjective evaluation of sound quality annoyance compared to traditional psychoacoustic parameters. Furthermore, the average error percentage of sound quality prediction based on the physiological model is only 3.81%, which is lower than that based on traditional psychoacoustic parameters.
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Percepção Sonora , Ruído dos Transportes , Psicoacústica , Humanos , Percepção Sonora/fisiologia , Estimulação Acústica/métodos , Análise de Elementos Finitos , Modelos Biológicos , Automóveis , Membrana Basilar/fisiologia , Cóclea/fisiologia , Percepção Auditiva/fisiologia , Ruído , Orelha Média/fisiologia , Simulação por ComputadorRESUMO
Robust object detection in complex environments, poor visual conditions, and open scenarios presents significant technical challenges in autonomous driving. These challenges necessitate the development of advanced fusion methods for millimeter-wave (mmWave) radar point cloud data and visual images. To address these issues, this paper proposes a radar-camera robust fusion network (RCRFNet), which leverages self-supervised learning and open-set recognition to effectively utilise the complementary information from both sensors. Specifically, the network uses matched radar-camera data through a frustum association approach to generate self-supervised signals, enhancing network training. The integration of global and local depth consistencies between radar point clouds and visual images, along with image features, helps construct object class confidence levels for detecting unknown targets. Additionally, these techniques are combined with a multi-layer feature extraction backbone and a multimodal feature detection head to achieve robust object detection. Experiments on the nuScenes public dataset demonstrate that RCRFNet outperforms state-of-the-art (SOTA) methods, particularly in conditions of low visual visibility and when detecting unknown class objects.
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Due to their sequence-directed functions and excellent biocompatibility, smart DNA microgels have attracted considerable research interest, and the combination of DNA microgels with functional nanostructures can further expand their applications in biosensing and biomedicine. Gallium-based liquid metals (LMs) exhibiting both fluidic and metallic properties hold great promise for the development of smart soft materials; in particular, LM particles upon sonication can mediate radical-initiated polymerization reactions, thus allowing the combination of LMs and polymeric matrix to construct "soft-soft" materials. Herein, by forming active surfaces under sonication, LM nanoparticles (LM NPs) initiated localized radical polymerization reactions allow the combination of functional DNA units and different polymeric backbones to yield multifunctional core/shell microgels. The localized polymerization reaction allows fine control of the microgel compositions, and smart DNA microgels with tunable catalytic activities can be constructed. Moreover, due to the excellent photothermal effect of LM NPs, the resulting temperature gradient between microgels and surrounding solution upon NIR light irradiation can drive the oriented locomotion of the microgels, and remote control of the activity of these smart microgels can be achieved. These microgels may hold promise for various applications, such as the development of in vivo and in vitro biosensing and drug delivery systems.
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Gálio , Microgéis , Polímeros Responsivos a Estímulos , Microgéis/química , Polímeros/química , DNA/químicaRESUMO
The electrochemical conversion of CO2 into valuable chemicals is a promising route for renowable energy storage and the mitigation of greenhouse gas emission, and production of multicarbon (C2+) products is highly desired. Here, we report a 1.4%Pd-Cu@CuPz2 comprising of dispersive CuOx and PdO dual nanoclusters embedded in the MOF CuPz2 (Pz = Pyrazole), which achieves a high C2+ Faradaic efficiency (FEC2+) of 81.9% and C2+ alcohol FE of 47.5% with remarkable stability when using 0.1 M KCl aqueous solution as electrolyte in a typical H-cell. Particularly, the FE of alcohol is obviously improved on 1.4%Pd-Cu@CuPz2 compared to Cu@CuPz2. Theoretical calculations have revealed that revealed that the enhanced interfacial electron transfer facilitates the adsorption of *CO intermediate and *CO-*CO dimerization on the Cu-Pd dual sites bridged by Cu nodes of CuPz2. Additionally, the oxophilicity of Pd can stabilize the key intermediate *CH2CHO and promote subsequent proton-coupled electron transfer more efficiently, confirming that the formation pathway is skew towards *C2H5OH. Consequently, the Cu-Pd dual sites play a synergistic tandem role in cooperatively improving the selectivity of alcohol and accelerating reductive conversion of CO2 to C2+.
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Allenes are important building blocks, and derivatization of products via cycloadditions of allenes could become a powerful strategy for constructing carbocyclic and heterocyclic rings. However, the development of catalytic site-selective and enantioselective cycloaddition reactions of allenes still presents significant challenges. Here, we report chiral π-Cu(II)-complex-catalyzed isomerization of N-(3-butynoyl)-3,5-dimethyl-1H-pyrazole to generate N-allenoylpyrazole in situ and subsequent α,ß-site-selective and enantioselective [3 + 2], [4 + 2], or [2 + 2] cycloaddition or conjugate addition reactions. The asymmetric environment created by the intramolecular π-Cu(II) interactions provides the corresponding adducts in moderate to high yield with excellent enantioselectivity. To the best of our knowledge, this is the first successful method for chiral-Lewis-acid-catalyzed tandem isomerization/α,ß-site-selective and enantioselective cycloaddition or conjugate addition reactions of latent non-γ-substituted allenoyl derivative.
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A rational design of high-efficiency electrocatalysts and thus achieving sensitive electrochemical sensing remains a great challenge. In this work, single-atom indium anchored on nitrogen-doped carbon (In1-N-C) with an In-N4 configuration is prepared successfully through a high-temperature annealing strategy; the product can serve as an advanced electrocatalyst for sensitive electrochemical sensing of dopamine (DA). Compared with In nanoparticle catalysts, In1-N-C exhibits high catalytic performance for DA oxidation. The theoretical calculation reveals that In1-N-C has high adsorption energy for hydroxy groups and a low energy barrier in the process of DA oxidation compared to In nanoparticles, indicating that In1-N-C with atomically dispersed In-N4 sites possesses enhanced intrinsic activity. An electrochemical sensor for DA detection is established as a concept application with high sensitivity and selectivity. Furthermore, we also verify the feasibility of In1-N-C catalysts for the simultaneous detection of uric acid, ascorbic acid, and DA. This work extends the application prospect of p-block metal single-atom catalysts in electrochemical sensing.
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Dopamina , Nanopartículas , Índio , Técnicas Eletroquímicas/métodos , Carbono , Ácido AscórbicoRESUMO
As advanced electrochemical catalysts, single-atom catalysts have made great progress in the field of catalysis and sensing due to their high atomic utilization efficiency and excellent catalytic performance. Herein, stannum-doped copper oxide (CuOSn1 ) nanosheets with single-site SnOCu pairs as active sites are synthesized as electrocatalysts for biological molecule detection. Compared with CuO-based electrochemical sensors, the CuOSn1 -based electrochemical sensors have improved detection sensitivity with a rapid electrochemical response. Theoretical calculation reveals that the single-site SnOCu pairs induced interfacial electronic transfer effect can strengthen hydroxy adsorption and thus reduce the energy barrier of the biological molecule oxidation process. As a concept application, electrochemical detection of dopamine and uric acid molecules is achieved, exhibiting satisfactory sensitivity and selectivity. This work demonstrates the advantages of single-site SnOCu pairs in electrochemical catalysis and sensing, which provides theoretical guidance for understanding the structure-activity relationship for sensitive electrochemical sensing.
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Exaggerated startle has been recognized as a core hyperarousal symptom of multiple fear-related anxiety disorders, such as post-traumatic stress disorder (PTSD) and panic disorder. However, the mechanisms driving this symptom are poorly understood. Here we reveal a neural projection from dorsal raphe nucleus (DRN) to a startle-controlling center reticulotegmental nucleus (RtTg) that mediates enhanced startle response under fear condition. Within RtTg, we identify an inhibitory microcircuit comprising GABAergic neurons in pericentral RtTg (RtTgP) and glutamatergic neurons in central RtTg (RtTgC). Inhibition of this RtTgP-RtTgC microcircuit leads to elevated startle amplitudes. Furthermore, we demonstrate that the conditioned fear-activated DRN 5-HTergic neurons send inhibitory projections to RtTgP GABAergic neurons, which in turn upregulate neuronal activities of RtTgC glutamatergic neurons. Chemogenetic activation of the DRN-RtTgP projections mimics the increased startle response under fear emotions. Moreover, conditional deletion of 5-HT1B receptor from RtTgP GABAergic neurons largely reverses the exaggeration of startle during conditioned fear. Thus, our study establishes the disinhibitory DRN-RtTgP-RtTgC circuit as a critical mechanism underlying exaggerated startle under fear emotions, and provides 5-HT1B receptor as a potential therapeutic target for treating hyperarousal symptom in fear-associated psychiatric disorders.
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Medo , Receptor 5-HT1B de Serotonina , Núcleo Dorsal da Rafe , Medo/fisiologia , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/fisiologia , Mesencéfalo/metabolismo , Mesencéfalo/fisiologia , Receptor 5-HT1B de Serotonina/genética , Receptor 5-HT1B de Serotonina/metabolismo , Reflexo de Sobressalto/fisiologia , Animais , CamundongosRESUMO
OBJECTIVES: To describe the prevalence of self-reported musculoskeletal disorders among workers in the electronics manufacturing industry and to investigate the relations between work-related musculoskeletal disorders (WMSDs) and work-related variables. METHODS: An interview-based questionnaire survey was carried out in thirty electronics manufacturing factories in China in 2018. The prevalence of WMSDs was estimated using the modified Nordic Musculoskeletal Questionnaire (NMQ). A multivariate logistic regression model was applied to evaluate the effects of risk factors on WMSDs on multiple body parts. RESULTS: The 12-month prevalence of WMSDs among participants was 40.6%, and the common body sites affected were the neck (26.8%), shoulder (22.8%), upper back (14.9%), and lower back (14.8%). The results of logistic regression showed that female adults, > 5 job tenure and work-related factors (including awkward posture, lifting or carrying weights, excessive repetition, prolonged sitting, monotonous work and working under conditions of cold or temperature variations) led to a higher risk of WMSDs on most body parts. Upper back, wrist/hand and elbow pain levels were significantly higher for workers with vibration. However, more frequently, physical exercise was a protective factor against WMSDs on most body parts except the upper back, leg and knee. CONCLUSIONS: The study indicates a high prevalence of musculoskeletal pain among the electronics manufacturing industry in China. Different personal and work factors are related to the occurrence of WMSD on different body parts. Preventive measures should be implemented based on the characteristics of WMSD in the electronic manufacturing industry. Furthermore, the training and intervention guidance of ergonomic hazards in the workplace need to be strengthened by understanding the impact of bad posture, avoiding long-term sitting posture and increasing physical activities.
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Doenças Musculoesqueléticas , Dor Musculoesquelética , Doenças Profissionais , Adulto , Humanos , Feminino , Prevalência , Estudos Transversais , Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Doenças Musculoesqueléticas/epidemiologia , Doenças Musculoesqueléticas/prevenção & controle , Fatores de Risco , Inquéritos e Questionários , Dor Musculoesquelética/epidemiologia , Ergonomia , China/epidemiologia , EletrônicaRESUMO
The use of mobile phones has become one of the major threats to road safety, especially in young novice drivers. To avoid crashes induced by distraction, adaptive distraction mitigation systems have been developed that can determine how to detect a driver's distraction state. A driving simulator experiment was conducted in this paper to better explore the relationship between drivers' cognitive distractions and traffic safety, and to better analyze the mechanism of distracting effects on young drivers during the driving process. A total of 36 participants were recruited and asked to complete an n-back memory task while following the lead vehicle. Drivers' vehicle control behavior was collected, and an ANOVA was conducted on both lateral driving performance and longitudinal driving performance. Indicators from three aspects, i.e., lateral indicators only, longitudinal indicators only, and combined lateral and longitudinal indicators, were inputted into both SVM and random forest models, respectively. Results demonstrated that the SVM model with parameter optimization outperformed the random forest model in all aspects, among which the genetic algorithm had the best parameter optimization effect. For both lateral and longitudinal indicators, the identification effect of lateral indicators was better than that of longitudinal indicators, probably because drivers are more inclined to control the vehicle in lateral operation when they were cognitively distracted. Overall, the comprehensive model built in this paper can effectively identify the distracted state of drivers and provide theoretical support for control strategies of driving distraction.
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Condução de Veículo , Direção Distraída , Humanos , Atenção , Máquina de Vetores de Suporte , Algoritmo Florestas Aleatórias , Cognição , Acidentes de Trânsito/prevenção & controleRESUMO
Automated vehicles are expected to greatly boost traffic efficiency. However, how to estimate traffic breakdown probability for the mixed flow of autonomous vehicles and human driven vehicles around ramping areas remains to be answered. In this paper, we propose a stochastic temporal queueing model to reliably depict the queue dynamics of mixed traffic flow at ramping bottlenecks. The new model is a specified Newell's car-following model that allows two kinds of vehicle velocities and first-in-first-out (FIFO) queueing behaviors. The jam queue join time is supposed to be a random variable for human driven vehicles but a constant for automated vehicles. Different from many known models, we check the occurrence of significant velocity drop along the road instead of examining the duration of the simulated jam queue so as to avoid drawing the wrong conclusions of traffic breakdown. Monte Carlo simulation results show that the generated breakdown probability curves for pure human driven vehicles agree well with empirical observations. Having noticed that various driving strategy of automated vehicles exist, we carry out further analysis to show that the chosen car-following strategy of automated vehicles characterizes the breakdown probabilities. Further tests indicate that when the penetration rate of automated vehicles is larger than 20%, the traffic breakdown probability curve of the mixed traffic will be noticeably shifted rightward, if an appropriate car-following strategy is applied. This indicates the potential benefit of automated vehicles in improving traffic efficiency.