Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 258
Filtrar
1.
ACS Appl Mater Interfaces ; 16(17): 22035-22047, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639478

RESUMO

Sodium (Na) super ion conductor (NASICON) structure Na3MnTi(PO4)3 (NMTP) is considered a promising cathode for sodium-ion batteries due to its reversible three-electron reaction. However, the inferior electronic conductivity and sluggish reaction kinetics limit its practical applications. Herein, we successfully constructed a three-dimensional cross-linked porous architecture NMTP material (AsN@NMTP/C) by a natural microbe of Aspergillus niger (AsN), and the structure of different NMTP cathodes was optimized by adjusting different transition metal Mn/Ti ratios. Both approaches effectively altered the three-dimensional NMTP structure, not only improving electronic conductivity and controlling Na+ diffusion pathways but also enhancing the electrochemical kinetics of the material. The resultant AsN@NMTP/C-650, sintered at 650 °C, exhibits better electrochemical performance with higher reversible three-electron reactions corresponding to the voltage platforms of Ti4+/3+, Mn3+/2+, and Mn4+/3+ around 2.1, 3.6, and 4.1 V (vs Na+/Na), respectively. The capacity retention rate is up to 89.3% after 1000 cycles at a 2C rate. Moreover, a series of results confirms that the Na3.4Mn1.2Ti0.8(PO4)3 cathode has the most excellent electrochemical performance when the Mn/Ti ratio is 1.2/0.8, with a high capacity of 96.59 mAh g-1 and 97.1% capacity retention after 500 cycles.

2.
Mol Genet Genomic Med ; 12(4): e2439, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613222

RESUMO

OBJECTIVE: To characterize the phenotype spectrum, diagnosis, and response to growth-promoting therapy in patients with ACAN variants causing familial short stature. METHODS: Three families with ACAN variants causing short stature were reported. Similar cases in the literature were summarized, and the genotype and phenotype were analyzed. RESULTS: Three novel heterozygous variants, c.757+1G>A, (splicing), c.6229delG, p.(Asp2078Tfs*1), and c.6679C>T, p.(Gln2227*) in the ACAN gene were identified. A total of 314 individuals with heterozygous variants from 105 families and 8 individuals with homozygous variants from 4 families were confirmed to have ACAN variants from literature and our 3 cases. Including our 3 cases, the variants reported comprised 33 frameshift, 39 missense, 23 nonsense, 5 splicing, 4 deletion, and 1 translocation variants. Variation points are scattered throughout the gene, while exons 12, 15, and 10 were most common (25/105, 11/105, and 10/105, respectively). Some identical variants existing in different families could be hot variants, c.532A>T, p.(Asn178Tyr), c.1411C>T, p.(Gln471*), c.1608C>A, p.(Tyr536*), c.2026+1G>A, (splicing), and c.7276G>T, p.(Glu2426*). Short stature, early-onset osteoarthritis, brachydactyly, midfacial hypoplasia, and early growth cessation were the common phenotypic features. The 48 children who received rhGH (and GnRHa) treatment had a significant height improvement compared with before (-2.18 ± 1.06 SD vs. -2.69 ± 0.95 SD, p < 0.001). The heights of children who received rhGH (and GnRHa) treatment were significantly improved compared with those of untreated adults (-2.20 ± 1.10 SD vs. -3.24 ± 1.14 SD, p < 0.001). CONCLUSION: Our study achieves a new understanding of the phenotypic spectrum, diagnosis, and management of individuals with ACAN variants. No clear genotype-phenotype relationship of patients with ACAN variants was found. Gene sequencing is necessary to diagnose ACAN variants that cause short stature. In general, appropriate rhGH and/or GnRHa therapy can improve the adult height of affected pediatric patients caused by ACAN variants.


Assuntos
Nanismo , Hormônio do Crescimento Humano , Adulto , Humanos , Criança , Genótipo , Fenótipo , Heterozigoto , Homozigoto , Pacientes , Agrecanas
3.
Orphanet J Rare Dis ; 19(1): 179, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685110

RESUMO

Mucopolysaccharidoses (MPSs) are caused by a deficiency in the enzymes needed to degrade glycosaminoglycans (GAGs) in the lysosome. The storage of GAGs leads to the involvement of several systems and even to the death of the patient. In recent years, an increasing number of therapies have increased the treatment options available to patients. Early treatment is beneficial in improving the prognosis, but children with MPSs are often delayed in their diagnosis. Therefore, there is an urgent need to develop a method for early screening and diagnosis of the disease. Tandem mass spectrometry (MS/MS) is an analytical method that can detect multiple substrates or enzymes simultaneously. GAGs are reliable markers of MPSs. MS/MS can be used to screen children at an early stage of the disease, to improve prognosis by treating them before symptoms appear, to evaluate the effectiveness of treatment, and for metabolomic analysis or to find suitable biomarkers. In the future, MS/MS could be used to further identify suitable biomarkers for MPSs for early diagnosis and to detect efficacy.


Assuntos
Mucopolissacaridoses , Espectrometria de Massas em Tandem , Humanos , Mucopolissacaridoses/diagnóstico , Mucopolissacaridoses/metabolismo , Espectrometria de Massas em Tandem/métodos , Biomarcadores/metabolismo , Glicosaminoglicanos/metabolismo
4.
Nat Commun ; 15(1): 2481, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509067

RESUMO

The development of highly efficient electrocatalysts for direct seawater splitting with bifunctionality for inhibiting anodic oxidation reconstruction and selective oxygen evolution reactions is a major challenge. Herein, we report a direct seawater oxidation electrocatalyst that achieves long-term stability for more than 1000 h at 600 mA/cm2@η600 and high selectivity (Faraday efficiency of 100%). This catalyst revolves an amorphous molybdenum oxide layer constructed on the beaded-like cobalt oxide interface by atomic layer deposition technology. As demonstrated, a new restricted dynamic surface self-reconstruction mechanism is induced by the formation a stable reconstructed Co-Mo double hydroxide phase interface layer. The device assembled into a two-electrode flow cell for direct overall seawater electrolysis maintained at 1 A/cm2@1.93 V for 500 h with Faraday efficiency higher than 95%. Hydrogen generation rate reaches 419.4 mL/cm2/h, and the power consumption (4.62 KWh/m3 H2) is lower than that of pure water (5.0 KWh/m3 H2) at industrial current density.

5.
Lipids Health Dis ; 23(1): 83, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509578

RESUMO

OBJECTIVE: To enhance the detection, management and monitoring of Chinese children afflicted with sitosterolemia by examining the physical characteristics and genetic makeup of pediatric patients. METHODS: In this group, 26 children were diagnosed with sitosterolemia, 24 of whom underwent genetic analysis. Patient family medical history, physical symptoms, tests for liver function, lipid levels, standard blood tests, phytosterol levels, cardiac/carotid artery ultrasounds, fundus examinations, and treatment were collected. RESULTS: The majority (19, 73.1%) of the 26 patients exhibited xanthomas as the most prevalent manifestation. The second most common symptoms were joint pain (7, 26.9%) and stunted growth (4, 15.4%). Among the 24 (92.3%) patients whose genetics were analyzed, 16 (66.7%) harbored ABCG5 variants (type 2 sitosterolemia), and nearly one-third (8, 33.3%) harbored ABCG8 variants (type 1 sitosterolemia). Additionally, the most common pathogenic ABCG5 variant was c.1166G > A (p.Arg389His), which was found in 10 patients (66.7%). Further analysis did not indicate any significant differences in pathological traits among those carrying ABCG5 and ABCG8 variations (P > 0.05). Interestingly, there was a greater abundance of nonsense variations in ABCG5 than in ABCG8 (P = 0.09), and a greater frequency of splicing variations in ABCG8 than ABCG5 (P = 0.01). Following a change in diet or a combination of ezetimibe, the levels of cholesterol and low-density lipoprotein were markedly decreased compared to the levels reported before treatment. CONCLUSION: Sitosterolemia should be considered for individuals presenting with xanthomas and increased cholesterol levels. Phytosterol testing and genetic analysis are important for early detection. Managing one's diet and taking ezetimibe can well control blood lipids.


Assuntos
Hipercolesterolemia , Enteropatias , Erros Inatos do Metabolismo Lipídico , Fitosteróis , Fitosteróis/efeitos adversos , Xantomatose , Humanos , Criança , Lipoproteínas/genética , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Fitosteróis/genética , Colesterol , Ezetimiba/uso terapêutico
6.
Sci Total Environ ; 926: 172080, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38554979

RESUMO

The perception of structure-borne noise is particularly salient when train passes through the tunnel under the buildings, which has a negative impact on human health. In the process of constructing buildings along metro lines, it is crucial to estimate indoor structure-borne noise levels in order to enhance design and prevent any negative impact on human comfort. This study conducted measurements of structure-borne noise, reverberation time, and train-induced vibrations in Guangzhou, China to investigate the generation, propagation, and dissipation mechanisms of structure-borne noise. An approach based on Short-Time Fourier Transform and Schroeder integral was proposed for obtaining frequency-dependent reverberation time. Additionally, a deep learning-based approach incorporating indoor vibrations, frequency-dependent reverberation time, and room parameters as inputs was proposed based on Genetic Algorithm-Artificial Neural Network. The estimated structure-borne noise levels demonstrated good agreement with measured values, indicating the feasibility of the approach. The finding of this research facilitates a clear comprehension of the generation, distribution, and dissipation mechanisms of indoor structure-borne noise for engineers while also enabling convenient acquisition of indoor structure-borne noise. The estimated noise levels can be effectively utilized during building design processes along metro lines to mitigate adverse impacts on human comfort.

7.
Huan Jing Ke Xue ; 45(3): 1293-1303, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471846

RESUMO

Electrification of bus fleets is an effective approach to reducing transportation-related pollution and carbon emissions. Evaluating the impact of electrification on existing bus fleets can provide valuable insights for promoting full electrification of public transportation in large cities. Utilizing the fuel life cycle method, we analyzed the CO2 and pollutant emissions of Zhengzhou's bus fleet before and after electrification and evaluated emissions under different electrification scenarios. Our results indicated that after electrification, the fuel life cycle CO2 and PM2.5 emissions increased by 32.6% and 42.6%, respectively, whereas CO, NOx, and VOC emissions decreased by 28%, 34%, and 25%, respectively. Optimizing the power generation structure is a critical factor in reducing CO2 and PM2.5 emissions during the electrification process. The best scenario for comprehensive electrification and power generation structure optimization could result in a 38.7% reduction in CO2, as well as reductions of 80.1% in CO, 84.4% in NOx, 92.2% in VOC, and 30.2% in PM2.5. Prioritizing electrification on long-distance routes is recommended during the replacement process. Additionally, replacing plug-in hybrid natural gas vehicles with pure electric vehicles has both advantages and disadvantages in terms of emission reduction. Achieving pollution reduction and carbon synergies requires advancing fleet replacement and power structure adjustments simultaneously.

8.
Langmuir ; 40(8): 4236-4244, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38364369

RESUMO

NiOx-based two-dimensional perovskite solar cells (2D-PSCs) have the advantages of low fabrication temperature, suitable energy level matching, suppressed hysteresis, and superior stability, while the poor interfacial contacts between NiOx and perovskite layers limit the perovskite film growth and charge transfer. Herein, a simple molecule, urea, was used as a molecular modifier to form bifacial passivation on the buried interface of NiOx/perovskite, resulting in better interfacial contact and efficient bifacial passivation. We demonstrated that efficient bifacial passivation mainly comes from strong interactions between urea and NiOx or perovskite, which make urea a molecular bridge for smoother charge transfer. Moreover, urea can regulate the ratio of Ni3+/Ni2+, therefore boosting the conductivity of NiOx, and adjust the morphology of the NiOx film for better 2D-perovskite crystal growth. Besides, urea also passivates the bifacial defect states of both NiOx and perovskite film, yielding reduced defect density of the perovskite film and superior charge transfer on the buried interface. Consequently, inverted 2D-PSCs with urea modification proved significant improvements in short-circuit current density and fill factor, resulting in improved power conversion efficiency from 14.64 to 16.84% with better stability in air.

9.
Quant Imaging Med Surg ; 14(2): 1591-1601, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38415124

RESUMO

Background: Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) has shown potential in reflecting the hepatic function alterations in nonalcoholic steatohepatitis (NASH). The purpose of this study was to evaluate whether Gd-EOB-DTPA combined with water-specific T1 (wT1) mapping can be used to detect liver inflammation in the early-stage of NASH in rats. Methods: In this study, 54 rats with methionine- and choline-deficient (MCD) diet-induced NASH and 10 normal control rats were examined. A multiecho variable flip angle gradient echo (VFA-GRE) sequence was performed and repeated 40 times after the injection of Gd-EOB-DTPA. The wT1 of the liver and the reduction rate of wT1 (rrT1) were calculated. All rats were histologically evaluated and grouped according to the NASH Clinical Research Network scoring system. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression of Gd-EOB-DTPA transport genes. Analysis of variance and least significant difference tests were used for multiple comparisons of quantitative results between all groups. Multiple regression analysis was applied to identify variables associated with precontrast wT1 (wT1pre), and receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance. Results: The rats were grouped according to inflammatory stage (G0 =4, G1 =15, G2 =12, G3 =23) and fibrosis stage (F0 =26, F1 =19, F2 =9). After the infusion of Gd-EOB-DTPA, the rrT1 showed significant differences between the control and NASH groups (P<0.05) but no difference between the different inflammation and fibrosis groups at any time points. The areas under curve (AUCs) of rrT1 at 10, 20, and 30 minutes were only 0.53, 0.58, and 0.61, respectively, for differentiating between low inflammation grade (G0 + G1) and high inflammation grade (G2 + G3). The MRI findings were verified by qRT-PCR examination, in which the Gd-EOB-DTPA transporter expressions showed no significant differences between any inflammation groups. Conclusions: The wT1 mapping quantitative method combined with Gd-EOB-DTPA was not capable of discerning the inflammation grade in a rat model of early-stage NASH.

10.
Materials (Basel) ; 17(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38399097

RESUMO

There is limited research on the fracture toughness of carbon-fiber-reinforced polymer (CFRP) materials under accelerated UV aging conditions. In this study, the primary focus was on investigating the influence of varying durations of ultraviolet (UV) irradiation at different temperatures on the Mode I, Mode II, and mixed-mode fracture toughness of CFRP laminates. The results indicate that with increasing UV aging duration, the material's Mode I fracture toughness increases, while Mode II fracture toughness significantly decreases. The mixed-mode fracture toughness exhibits an initial increase followed by a subsequent decrease. Furthermore, as the aging temperature increases, the change in the fracture toughness of the material is more obvious and the rate of change is faster. In addition, the crack expansion of the composite layer of crack-containing Type IV hydrogen storage cylinders was analyzed based on the extended finite element method in conjunction with the performance data after UV aging. The results reveal that cracks in the aged composite material winding layers become more sensitive, with lower initiation loads and longer crack propagation lengths under the same load. UV aging diminishes the overall load-bearing capacity and crack resistance of the hydrogen storage cylinder, posing increased safety risks during its operational service.

11.
BMC Pediatr ; 24(1): 118, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355440

RESUMO

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic disease often associated with bone problems, mainly scoliosis and hip dysplasia (HD). This study aimed to analyze the clinical characteristics of orthopedic deformities in patients with PWS. METHODS: A retrospective study was conducted on 175 patients up to March 2023. The Cobb angle(CA) of the spine, the alpha angle of the hip joint, and the acetabular index (AI) were measured. This study aimed to evaluate the relationship between demographic parameters and bone deformities. RESULTS: Scoliosis was found in 66 patients (43.7%), including 52 (78.8%) with mild scoliosis, 10 (15.2%) with moderate scoliosis, and 4 (6.1%) with severe scoliosis. Only seven patients received orthopedic treatment (10.6%). The median age of scoliosis was 4.5 years old, and the prevalence of scoliosis increased rapidly at the age of 5 years and adolescence. The mean CA in this study increased gradually with age. HD was found in 47 patients (38.2%), and 6 patients received orthopedic treatment (12.7%). The median age at HD was 1.8 years old. The mean AI of the study population decreased with age. The prevalence of HD treated with recombinant human growth hormone (rhGH) was low. No significant differences were observed in sex, genotype, body mass index (BMI), obesity rate, or onset of scoliosis and HD. CONCLUSION: The prevalence of scoliosis and HD was higher in patients with PWS. The onset age and developmental trends of the different skeletal malformations were different. Early diagnosis and treatment are important for the prognosis and treatment of orthopedic diseases in patients with PWS.


Assuntos
Hormônio do Crescimento Humano , Síndrome de Prader-Willi , Escoliose , Criança , Adolescente , Humanos , Pré-Escolar , Lactente , Síndrome de Prader-Willi/complicações , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/tratamento farmacológico , Escoliose/etiologia , Estudos Retrospectivos , Hormônio do Crescimento Humano/uso terapêutico , Obesidade/complicações
12.
Inorg Chem ; 63(7): 3267-3282, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38307513

RESUMO

Homoleptic W(0) and Mo(0) complexes containing bis(triarylisocyanide) ligands with bulky substituents were synthesized and spectroscopically characterized. Crystallographically determined structures revealed that these complexes are hourglass-like in shape with the tridentate ligands adopting a facial coordination mode to the metal center. These complexes luminesce in fluid solutions and in the solid state. Typically in toluene at 298 K, the two W(0) complexes display the emission maximum (lifetime and quantum yield) at 591 nm (0.83 µs and 0.35) and 628 nm (1.04 µs and 0.39), and similarly, the two Mo(0) complexes display it at 575 nm (0.54 µs and 0.15) and 617 nm (0.56 µs and 0.23). DFT and TDDFT calculations indicated that the low-energy absorption bands of the W(0) and Mo(0) complexes could be metal-to-ligand charge transfer (MLCT) transitions in nature. These complexes exhibited a reversible M+/0 redox couple at -0.70 and -0.63 V vs Fc+/0 for the W(0) complexes and -0.86 and -0.67 V for the Mo(0) complexes. The excited-state reduction potentials were hence estimated to be -2.91 and -2.74 V vs Fc+/0 for the W(0) complexes and -3.10 and -2.81 V vs Fc+/0 for the Mo(0) complexes, indicating that they are potentially strong photoreductants.

13.
MAGMA ; 37(2): 215-226, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38019377

RESUMO

OBJECTIVE: The study aims to propose an accurate labelling method of interscapular BAT (iBAT) in rats using dynamic MR fat fraction (FF) images with noradrenaline (NE) stimulation and then develop an automatic iBAT segmentation method using a U-Net model. MATERIALS AND METHODS: Thirty-four rats fed different diets or housed at different temperatures underwent successive MR scans before and after NE injection. The iBAT were labelled automatically by identifying the regions with obvious FF change in response to the NE stimulation. Further, these FF images along with the recognized iBAT mask images were used to develop a deep learning network to accomplish the robust segmentation of iBAT in various rat models, even without NE stimulation. The trained model was then validated in rats fed with high-fat diet (HFD) in comparison with normal diet (ND). RESULT: A total of 6510 FF images were collected using a clinical 3.0 T MR scanner. The dice similarity coefficient (DSC) between the automatic and manual labelled results was 0.895 ± 0.022. For the network training, the DSC, precision rate, and recall rate were found to be 0.897 ± 0.061, 0.901 ± 0.068 and 0.899 ± 0.086, respectively. The volumes and FF values of iBAT in HFD rats were higher than ND rats, while the FF decrease was larger in ND rats after NE injection. CONCLUSION: An automatic iBAT segmentation method for rats was successfully developed using the dynamic labelled FF images of activated BAT and deep learning network.


Assuntos
Tecido Adiposo Marrom , Aprendizado Profundo , Ratos , Animais , Tecido Adiposo Marrom/diagnóstico por imagem , Norepinefrina , Dieta Hiperlipídica , Espectroscopia de Ressonância Magnética , Imageamento por Ressonância Magnética/métodos
14.
J Magn Reson Imaging ; 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38050865

RESUMO

BACKGROUND: Axial spondyloarthritis (axSpA) is a group of inflammatory diseases that may lead to ankylosis of the sacroiliac joint and spine. Fat lesion in the sacroiliac joint is an important feature in diagnosis and disease progression of axSpA. However, whether there is alteration of fatty acids (FAs) composition has not been investigated using MRI. PURPOSE: To investigate bone marrow FA composition of the sacroiliac joint in patients with axSpA compared to controls. STUDY TYPE: Prospective. SUBJECTS: Eighty five participants (mean age, 32.3 ± 6.1 years): 48 axSpA (25 male, 23 female) and 37 non-SpA controls (18 male, 19 female). FIELD STRENGTH/SEQUENCE: 3.0 T/Two multiple gradient-echo chemical shift-encoded (CSE) MRI which differed only in echo times (TEs) were scanned consecutively. ASSESSMENT: Axial multi-echo CSE MRI was performed in the sacroiliac joints in vivo. Regions of interest (ROIs) were manually placed on subchondral bone with and without fat lesion in axSpA patients, and on subchondral bone without fat lesion in controls. FA composition was computed within the ROIs using a nonlinear least square method from literature. STATISTICAL TESTS: Intergroup comparisons were performed using t tests. RESULTS: In axSpA, male patients had significantly higher monounsaturated FA compared to controls in areas with fat lesion in the sacrum (+12%) and in the ilium (+9%), and in areas without fat lesion in the sacrum (+10%). Significantly lower polyunsaturated FAs were found in areas with fat lesion in the sacrum (-10%) and ilium (-11%), and lower saturated FAs were found in areas without fat lesion in the sacrum (-6%). In female, patients with axSpA had significantly higher saturated FAs in areas with fat lesion in the ilium (+7%) in comparison to controls. DATA CONCLUSION: FA composition of the sacroiliac joint alters in patients with axSpA, and it can be detected using CSE MRI based analysis.

15.
J Org Chem ; 88(20): 14836-14841, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37779438

RESUMO

A series of diphenylboron-chelating N-substituent 8-aminoquinoline, 5-aminoquinoxaline, and 1-aminophenazine were prepared. They exhibit lowest energy absorption peaks of 444-766 nm, emission peaks of 563-820 nm, and quantum yields of up to 46.5%. Electrochemical and theoretical studies indicate that the N-substituent mainly determines the HOMO and the framework determines the LUMO, thus allowing for a wide-tuning of absorptions/emissions. Intramolecular charge transfer transition leads to large Stokes shifts of up to 166 nm. One selected compound showed satisfactory cytocompatibility and cytoplasm-targeting cell imaging ability.

16.
Chem Commun (Camb) ; 59(78): 11652-11655, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37655497

RESUMO

Bis(adamantylidene-1,2-dioxetane), upon conjugation to a planar chiral scaffold of [2.2]paracyclophane, gave chemical-triggerable circularly polarized chemiluminescence with a dissymmetry factor of 1.1 × 10-3 scale, to which exciton chirality upon chemiexcitation was assigned as the origin.

17.
Environ Pollut ; 336: 122472, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37648057

RESUMO

The Beijing Daxing International Airport is a newly opened airport, and a comprehensive emission inventory of air pollution sources has not yet been established. The lack of basic inventory data will cause difficulties in controlling the air quality (AQ) in and around the airport. Based on actual flight data, we established a comprehensive emission inventory (carbon monoxide (CO), nitrogen oxides (NOX), hydrocarbons (HC), sulfur dioxide (SO2), particulate matter (PM), and carbon dioxide (CO2)) at Beijing Daxing International Airport. Furthermore, we evaluated the impact of airport emissions on the AQ of the surrounding areas using the ADMS-Airport model. The results showed that Beijing Daxing International Airport emitted 1.15 E+03, 1.76 E+03, 1.38 E+02, 1.16 E+02, 3.53 E+01, and 3.75 E+05 t of CO, NOX, HC, SO2, PM, and CO2, respectively, from July 1, 2020, to June 30, 2021. Engine exhaust emissions (landing and takeoff [LTO] cycles) dominated all airport pollutant emissions except for PM from the power plant. Among all aircraft types, B738 emitted the most CO2, as it accounted for almost half of all the flights. The AQ simulations showed that the air pollutant diffusion range was concentrated within 15 km of the airport and the surrounding areas. The contribution of airport emissions to NOX concentrations was most apparent under the most unfavorable meteorological conditions. Based on the average pollutant concentration during the study period, the Gu'an Li Hu Primary School station was the most affected. In particular, NOX concentrations at this station were approximately 50% higher in winter than in summer. Currently, the airport's contribution to pollution in the surrounding areas is insignificant. However, with the continuous increase in the number of flights at the airport, its impact on the AQ in the surrounding areas must be addressed in the future.

18.
J Colloid Interface Sci ; 650(Pt B): 1842-1850, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37515974

RESUMO

Sluggish kinetics of hydrogen oxidation reaction (HOR) in alkaline solution has restricted the rapid development of hydrogen economy. Constructing catalyst with metal-oxide heterostructures can enhance HOR performance; however, little studies concentrate on charge transfer between them, and the corresponding effects on reactions remain unclear. Herein, we report charge-transfer-adjustable CeO2/Rh interfaces uniformly dispersed on multiwalled carbon nanotube (CNT), which exhibit excellent alkaline HOR performance. Results confirm that the charge transfer from Rh to CeO2 could be conveniently tuned via thermal treatment. Consequently, the adsorption free energies of H* in Rh sites and OH* adsorption strength in CeO2 could be adjusted, as corroborated by density functional theory study. The optimized CeO2/Rh interfaces exhibit an exchange current density and a mass-specific kinetic current of 0.53 mA cmPGM-2 and 830 A gPGM-1 at an overpotential of 50 mV, respectively, which surpasses most of the advanced noble-metal-based electrocatalysts. This work provides a new insight of harnessing charge transfer of heterostructure to enhance catalytic activities.

19.
Sci Rep ; 13(1): 11650, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468706

RESUMO

Mediation by sulphate-reducing bacteria (SRB) is responsible for pyrite (FeS2) formation. The origin of the Dachang tin polymetallic ore field is related to the mineralisation of submarine hydrothermal vent sediments. Here, we investigated SRB in these ores via morphological, chemical, and isotopic analyses. Polarised and scanning electron microscopy indicated that trace SRB fossils in the metal sulphide ore were present in the form of tubular, beaded, and coccoidal bodies comprising FeS2 and were enclosed within a pyrrhotite (FeS) matrix in the vicinity of micro-hydrothermal vents. The carbon (C), nitrogen (N), and oxygen (O) contents in the FeS2 synthesised by SRB were high, and a clear biological Raman signal was detected. No such signals were discerned in the peripheral FeS. This co-occurrence of FeS, FeS2, and the remains of bacteria (probably chemoautotrophic bacteria) was interpreted as the coprecipitation process of SRB-mediated FeS2 formation, which has, to the best of our knowledge, not been reported before. Our study also illustrates that combined energy-dispersive X-ray spectroscopy, Raman spectroscopy, and isotopic analysis can be used as a novel methodology to document microbial-mediated processes of mineral deposition in submarine hydrothermal vent ecology on geological time scales.


Assuntos
Desulfovibrio , Estanho , China , Sulfetos , Bactérias , Sulfatos
20.
IEEE Trans Biomed Eng ; 70(12): 3381-3388, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37318962

RESUMO

OBJECTIVE: The purpose of this work is to develop a 3-channel endorectal coil (ERC-3C) structure to obtain higher signal-to-noise (SNR) and better parallel imaging performance for prostate magnetic resonance imaging (MRI) at 3T. METHODS: The coil performance was validated by in vivo studies and the SNR, g-factor, and diffusion-weighted imaging (DWI) were compared. A 2-channel endorectal coil (ERC-2C) with two orthogonal loops and a 12-channel external surface coil were employed for comparison. RESULTS: Compared with the ERC-2C with a quadrature configuration and the external 12-channel coil array, the proposed ERC-3C improved SNR performance by 23.9% and 428.9%, respectively. The improved SNR enables the ERC-3C to produce spatial high-resolution images of 0.24 mm × 0.24 mm × 2 mm (0.1152 µL) in the prostate area within 9 minutes. CONCLUSION: We developed an ERC-3C and validated its performance through in vivo MR imaging experiments. SIGNIFICANCE: The results demonstrated the feasibility of an ERC with more than two channels and that a higher SNR can be achieved using the ERC-3C compared with an orthogonal ERC-2C of the same coverage.


Assuntos
Próstata , Neoplasias da Próstata , Humanos , Masculino , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Pelve , Razão Sinal-Ruído
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...