Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
Appl Opt ; 63(8): 2109-2120, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38568655

RESUMO

This paper proposes a switchable multifunctional metamaterial device operating in the terahertz (THz) band. The device is loaded with an equivalent diode and utilizes vanadium dioxide (V O 2). The middle layer of the whole device, a metal layer, divides the device into the I side and the II side. When the diode is ON, the I side can achieve dual-band absorption at 1.975 and 4.345 THz. When the diode is OFF, the I side can achieve single-band absorption at 4.28 THz. In the case of V O 2 being insulating, the II side can achieve linear-to-linear (LTL) polarization conversion at 2.342-4.18 THz. In the case of V O 2 being conductive, the II side can realize linear-to-circular (LTC) polarization conversion at 2.105-3.283 THz. The device provides a new strategy for the subsequent combination of multiple functions. The device can be used in electromagnetic stealth, intelligent applications, radiometers, and sensors and has relatively large application potential in miniaturized multifunctional metamaterials and THz band research.

2.
Front Immunol ; 15: 1353339, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464524

RESUMO

As a new type of anti-tumor immunotherapy, immune checkpoint inhibitors (ICIs) have improved the prognosis of multiple malignancies. However, renal complications are becoming more frequent. Nephrotoxicity often manifests as acute kidney injury (AKI), and the most common histopathological type is acute tubulointerstitial nephritis (ATIN). Based on previous studies of the incidence and potential risk factors for nephrotoxicity, in this review, we describe the mechanism of AKI after ICIs treatment, summarize the incidence, risk factors, and outcomes of AKI, and discuss the diagnosis and management of immune checkpoint inhibitors-associated acute kidney injury (ICI-AKI). In addition, we review the current status of ICIs rechallenge and the therapeutic strategies of ICIs applied in kidney transplant recipients. Finally, we emphasize the importance of collaboration between nephrologists and oncologists to guide the treatment of ICIs and the management of renal complications.


Assuntos
Injúria Renal Aguda , Nefrite Intersticial , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/terapia , Rim , Imunoterapia/efeitos adversos , Nefrite Intersticial/induzido quimicamente
3.
Adv Mater ; 36(21): e2311643, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38407359

RESUMO

Ultrafast manipulation of magnetic order has challenged the understanding of the fundamental and dynamic properties of magnetic materials. So far single-shot magnetic switching has been limited to ferrimagnetic alloys, multilayers, and designed ferromagnetic (FM) heterostructures. In FM/antiferromagnetic (AFM) bilayers, exchange bias (He) arises from the interfacial exchange coupling between the two layers and reflects the microscopic orientation of the antiferromagnet. Here the possibility of single-shot switching of the antiferromagnet (change of the sign and amplitude of He) with a single femtosecond laser pulse in IrMn/CoGd bilayers is demonstrated. The manipulation is demonstrated in a wide range of fluences for different layer thicknesses and compositions. Atomistic simulations predict ultrafast switching and recovery of the AFM magnetization on a timescale of 2 ps. The results provide the fastest and the most energy-efficient method to set the exchange bias and pave the way to potential applications for ultrafast spintronic devices.

4.
ACS Nano ; 18(1): 761-769, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38127497

RESUMO

Magnetic skyrmions are topologically protected swirling spin textures with great potential for future spintronic applications. The ability to induce skyrmion motion using mechanical strain not only stimulates the exploration of exotic physics but also affords the opportunity to develop energy-efficient spintronic devices. However, the experimental realization of strain-driven skyrmion motion remains a formidable challenge. Herein, we demonstrate that the inhomogeneous uniaxial compressive strain can induce the movement of isolated skyrmions from regions of high strain to regions of low strain at room temperature, which was directly observed using an in situ Lorentz transmission electron microscope with a specially designed nanoindentation holder. We discover that the uniaxial compressive strain can transform skyrmions into a single domain with in-plane magnetization, resulting in the coexistence of skyrmions with a single domain along the direction of the strain gradient. Through comprehensive micromagnetic simulations, we reveal that the repulsive interactions between skyrmions and the single domain serve as the driving force behind the skyrmion motion. The precise control of skyrmion motion through strain provides exciting opportunities for designing advanced spintronic devices that leverage the intricate interplay between strain and magnetism.

5.
Front Bioeng Biotechnol ; 11: 1273263, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38026896

RESUMO

Objective: This study presents an innovative articular fossa prosthesis generated by the envelope surface of condyle movement, and compares its mandible movements, muscle activities, and joint reaction forces with two temporomandibular joint (TMJ) prostheses using multibody musculoskeletal simulation. Methods: A healthy 23-year-old female was recruited for this study. Cone-beam computed tomographic (CBCT) was performed to reconstruct the mandibular bone geometry. A customized TMJ fossa prosthesis was designed based on the subject-specific envelope surface of condyle movement (ESCM). Mandibular kinematics and jaw-closing muscle electromyography (EMG) were simultaneously recorded during maximum jaw opening-closing movements. To validate our prosthesis design, a mandibular musculoskeletal model was established using flexible multibody dynamics and the obtained kinematics and EMG data. The Biomet fossa prosthesis and the ellipsoidal fossa prosthesis designed by imitating the lower limb prostheses were used for comparison. Simulations were performed to analyze the effects of different fossa prostheses on jaw opening-closing motions, mandibular muscle activation, and contact forces. Results: The maximum opening displacement for the envelope-based fossa prosthesis was greater than those for Biomet and ellipsoidal prostheses (36 mm, 35 mm, and 33 mm, respectively). The mandibular musculoskeletal model with ellipsoidal prosthesis led to dislocation near maximal jaw opening. Compared to Biomet, the envelope-based fossa reduced the digastric and lateral pterygoid activation at maximal jaw opening. It also reduced the maximal resistance to condylar sliding on the intact side by 63.2 N. Conclusion: A customized TMJ fossa prosthesis was successfully developed using the ESCM concept. Our study of musculoskeletal multibody modeling has highlighted its advantages and potential. The artificial fossa design successfully achieved a wider condylar range of motion. It also reduced the activation of jaw opening muscles on the affected side and resistance on the intact side. This study showed that an ESCM-based approach may be useful for optimizing TMJ fossa prostheses design.

6.
Ageing Res Rev ; 92: 102094, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37863436

RESUMO

As a global public health problem, low back pain (LBP) caused by intervertebral disc degeneration (IDD) seriously affects patients' quality of life. In addition, the prevalence of IDD tends to be younger, which brings a huge burden to individuals and society economically. Current treatments do not delay or reverse the progression of IDD. The emergence of biologic therapies has brought new hope for the treatment of IDD. Among them, extracellular vesicles (EVs), as nanoscale bioactive substances that mediate cellular communication, have now produced many surprising results in the research of the treatment of IDD. This article reviews the mechanisms and roles of EVs in delaying IDD and describes the prospects and challenges of EVs.


Assuntos
Vesículas Extracelulares , Degeneração do Disco Intervertebral , Deslocamento do Disco Intervertebral , Humanos , Degeneração do Disco Intervertebral/terapia , Qualidade de Vida
7.
Front Pediatr ; 11: 1210569, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37670741

RESUMO

Background: The impact of hypertensive disorders of pregnancy (HDP) on outcomes of twin gestations is not clear. We aimed to collate data via this meta-analysis to examine how HDP alters maternal and neonatal outcomes of twin gestations. Methods: Studies comparing pregnancy outcomes of twin gestations based on HDP and published on the databases of PubMed, CENTRAL, Scopus, Web of Science, and Embase between 1 January 2000 to 20 March 2023 were eligible for inclusion. Results: Twelve studies were included. A cumulative of 355,129 twin gestations were analyzed in the current meta-analysis. The pooled analysis found that the presence of HDP increases the risk of preterm birth (OR: 1.86 95% CI: 1.36, 2.55 I2 = 99%) and cesarean section in twin gestations (OR: 1.36 95% CI: 1.20, 1.54 I2 = 89%). Meta-analysis showed a significantly increased risk of low birth weight (OR: 1.30 95% CI: 1.10, 1.55 I2 = 97%), small for gestational age (OR: 1.30 95% CI: 1.09, 1.55 I2 = 96%) and neonatal intensive care unit admissions (OR: 1.77 95% CI: 1.43, 2.20 I2 = 76%) with HDP in twin gestations. There was no difference in the incidence of 5-min Apgar scores <7 (OR: 1.07 95% CI: 0.87, 1.38 I2 = 79%) but a lower risk of neonatal death (OR: 0.39 95% CI: 0.25, 0.61 I2 = 62%) with HDP. Conclusion: HDP increases the risk of preterm birth, cesarean sections, low birth weight, SGA, and NICU admission in twin gestations. Contrastingly, the risk of neonatal death is reduced with HDP. Further studies are needed to corroborate the current results. Systematic Review Registration: PROSPERO (CRD42023407725).

8.
Front Cardiovasc Med ; 10: 1207339, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37593147

RESUMO

Here, we report an unusual case of left atrial myxoma presented with morphology of cavernous hemangioma supplied by the right coronary artery. Surgical resection of the left atrium myxoma was performed, and the patient experienced an uneventful recovery during hospitalization.

9.
Heliyon ; 9(7): e17769, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37483714

RESUMO

The present study aimed to predict the envelope surfaces from facial morphology. Condylar envelope surfaces for 34 healthy adults were formed and simplified as sagittal section curves. Cephalometric and maximum mandibular moving distances measurement were performed on the participants. There was no statistically significant difference (p = 0.763) between the left and right maximum lateral movements. There was a statistically significant difference in the mandibular body length between the sexes. The envelope surfaces were divided into type 1 with Hp2 ≥ 1/3 Hp1 and type 2 with Hp2 < 1/3 × Hp1. SNA and SNB for type 2 were significantly greater than those for type 1 (p < 0.001). Therefore, the participants were divided into four groups based on gender and envelope surface morphology. The curves could be fitted using the second-order Fourier function (R-square ≥0.95). Six facial parameters were selected and a matrix was used to map facial morphology to the envelope surface. Individual sagittal curves were predicted using the matrix and facial parameters, and the envelope surface was predicted using the curve and the condyle model. Deviation analysis for the predicted envelope surface using the actual envelope as a reference was carried out (root mean square = 0.9970 mm ± 0.2918 mm). This method may lay a foundation for the geometric design of artificial fossa components of temporomandibular joint replacement systems. It may improve prosthesis design without flexible tissue repair and guide the movement of the artificial joint head.

10.
J Ethnopharmacol ; 316: 116760, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37301307

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Potentilla discolor Bunge (PD) is a member of the Rosaceae family. It has been traditionally used in folk medicine for the treatment of diabetes. Additionally, people in folk also eat fresh and tender PD stems as vegetables or brew them as tea. AIM OF THE STUDY: The aim of this study was to explore the antidiabetic effects and underlying mechanisms of the water extract of Potentilla discolor (PDW) in a fruit fly model of high-sugar diet-induced type 2 diabetes. MATERIALS AND METHODS: The antidiabetic efficacy of PDW was evaluated in a fruit fly model of diabetes induced by a high-sugar diet (HSD). Various physiological parameters were tested to evaluate the anti-diabetic effect of PDW. Gene expression levels related to insulin signaling pathways, glucose metabolism, lipid metabolism, and JAK/STAT signaling pathways were primarily analyzed using RT-qPCR to investigate the therapeutic mechanisms. RESULTS: In this study, we found that the water extract of Potentilla discolor (PDW) can ameliorate type II diabetes phenotypes induced by the HSD in fruit flies. These phenotypes include growth rate, body size, hyperglycemia, glycogen metabolism, fat storage, and intestinal microflora homeostasis. PDW also improved the body size of s6k and rheb knockdown flies, suggesting its potential to activate the downstream insulin pathway and alleviate insulin resistance. Furthermore, we demonstrated that PDW reduced the expression of two target genes of the JAK/STAT signaling pathway, namely the insulin antagonist Impl2 and insulin receptor inhibitor Socs36E, which act as regulators inhibiting the activation of the insulin signaling pathway. CONCLUSIONS: This study provides evidence for the anti-diabetic activity of PDW and suggests that its underlying mechanism may involve the improvement of insulin resistance by inhibiting the JAK/STAT signaling pathway.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Potentilla , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Drosophila melanogaster , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Transdução de Sinais , Dieta , Açúcares/metabolismo
11.
Appl Opt ; 62(12): 3149-3159, 2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37133163

RESUMO

This paper proposes a multifunctional metamaterial device operating in the terahertz (THz) band. The metamaterial device can switch functions by using the phase transition properties of vanadium dioxide (V O 2) and the photoconductive effect of silicon. An intermediate metal layer divides the device into the I side and II side. When V O 2 is in the insulating state, the I side can achieve polarization conversion from linear polarization waves to linear polarization waves at 0.408-0.970 THz. When V O 2 is in the metal-like state, the I side can perform polarization conversion from linear polarization waves to circular polarization waves at 0.469-1.127 THz. When silicon is not excited in the absence of light, the II side can perform polarization conversion from linear polarization waves to linear polarization waves at 0.799-1.336 THz. As the light intensity increases, the II side can realize stable broadband absorption at 0.697-1.483 THz when silicon is in the conductive state. The device can be applied to wireless communications, electromagnetic stealth, THz modulation, THz sensing, and THz imaging. Moreover, it provides a fresh idea for the design of multifunctional metamaterial devices.

12.
Front Vet Sci ; 10: 1099255, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37180076

RESUMO

Lysine acetylation modification is a dynamic and reversible post-translational modification, which plays an important role in the metabolism and pathogenicity of pathogenic bacteria. Vibrio alginolyticus is a common pathogenic bacterium in aquaculture, and bile salt can trigger the expression of bacterial virulence. However, little is known about the function of lysine acetylation in V. alginolyticus under bile salt stress. In this study, 1,315 acetylated peptides on 689 proteins were identified in V. alginolyticus under bile salt stress by acetyl-lysine antibody enrichment and high-resolution mass spectrometry. Bioinformatics analysis found that the peptides motif ****A*Kac**** and *******Kac****A* were highly conserved, and protein lysine acetylation was involved in regulating various cellular biological processes and maintaining the normal life activities of bacteria, such as ribosome, aminoacyl-tRNA biosynthesis, fatty acid metabolism, two-component system, and bacterial secretion system. Further, 22 acetylated proteins were also found to be related to the virulence of V. alginolyticus under bile salt stress through secretion system, chemotaxis and motility, and adherence. Finally, comparing un-treated and treated with bile salt stress lysine acetylated proteins, it was found that there were 240 overlapping proteins, and found amino sugar and nucleotide sugar metabolism, beta-Lactam resistance, fatty acid degradation, carbon metabolism, and microbial metabolism in diverse environments pathways were significantly enriched in bile salt stress alone. In conclusion, this study is a holistic analysis of lysine acetylation in V. alginolyticus under bile salt stress, especially many virulence factors have also acetylated.

13.
IEEE/ACM Trans Comput Biol Bioinform ; 20(5): 3306-3313, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37037235

RESUMO

The functions of proteins are largely determined by their three-dimensional (3D) structures. Loop modeling tries to predict the conformation of a relatively short stretch of protein backbone and sidechain. It is a difficult problem due to conformational variability. Recently, AlphaFold2 has achieved outstanding results in 3-D protein structure prediction and is expected to perform well on loop modeling. In this paper, we investigate the performances of AlphaFold2 variants on popular loop modeling benchmark datasets and propose an efficient protocol of using AlphaFold2 for loop modeling, called IAFLoop. To predict the structure of a loop region, IAFLoop gives a moderately extended segment of the target loop region as input to AlphaFold2, runs a fast version of AlphaFold2 using a reduced database without ensembling, and uses RMSD based consensus scores to select the final output models. Our experimental results on benchmark datasets show that IAFLoop generated highly accurate loop models. It achieves comparable performance to the original application of AlphaFold2 in terms of RMSD error, and achieving much better results on some targets, while only using half of the time. Compared to the best previous methods, IAFLoop reduces the RMSD error by almost half on the 8-residual loop dataset, and more than 70% on the 12-residual loop dataset.


Assuntos
Proteínas , Proteínas/genética , Proteínas/química , Conformação Proteica , Bases de Dados Factuais
14.
Folia Neuropathol ; 61(1): 1-7, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37114955

RESUMO

Cerebral small vessel disease (cSVD) is a disease defined by clinical symptoms and neuroimaging, which often causes a series of pathophysiological changes, blood-brain barrier destruction, brain tissue ischemia and involves cerebral arterioles, capillaries and venules. The exact pathogenesis of cSVD is unclear and there is no specific prevention and treatment for this potentially high disability rate disease. This article reviewed the latest research progress of neuroimaging of cSVD in order to improve our understanding of cSVD's manifestation and potential mechanism. We introduced the neuroimaging markers which can be accurately identified by diffusion tensor imaging, including recent subcortical infarction, white matter lesions, brain atrophy, lacunar infarction, cerebral microhaemorrhage and other cSVD neuroimaging markers. Besides, we also interpreted the total load score of cSVD, which described a wide range of clinical, pathological and neuroimaging features, reflecting the acute and chronic damage of the whole brain. Combined with the neuroimaging methods, capturing the imaging features of early cSVD can improve the diagnostic ability of cSVD and provide strong support for the longitudinal study.


Assuntos
Isquemia Encefálica , Doenças de Pequenos Vasos Cerebrais , Humanos , Imagem de Tensor de Difusão/efeitos adversos , Estudos Longitudinais , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/patologia , Neuroimagem , Encéfalo/patologia , Isquemia Encefálica/complicações , Imageamento por Ressonância Magnética
15.
Int J Mol Sci ; 24(8)2023 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-37108087

RESUMO

Tigecycline is a last-resort antibiotic for the treatment of infections caused by multidrug-resistant bacteria. The emergence of plasmid-mediated tigecycline resistance genes is posing a serious threat to food safety and human health and has attracted worldwide attention. In this study, we characterized six tigecycline-resistant Escherichia fergusonii strains from porcine nasal swab samples collected from 50 swine farms in China. All the E. fergusonii isolates were highly resistant to tigecycline with minimal inhibitory concentration (MIC) values of 16-32 mg/L, and all contained the tet(X4) gene. In addition, 13-19 multiple resistance genes were identified in these isolates, revealed by whole-genome sequencing analysis. The tet(X4) gene was identified as being located in two different genetic structures, hp-abh-tet(X4)-ISCR2 in five isolates and hp-abh-tet(X4)-ΔISCR2-ISEc57-IS26 in one isolate. The role of efflux pumps in tigecycline resistance was evaluated by using inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). The MIC values of tigecycline showed a 2- to 4-fold reduction in the presence of CCCP, indicating the involvement of active efflux pumps in tigecycline resistance in E. fergusonii. The tet(X4) gene was found to be transferable to Escherichia coli J53 by conjugation and resulted in the acquisition of tigcycline resistances in the transconjugants. Whole-genome multilocus sequence typing (wgMLST) and phylogenetic analysis showed a close relationship of five isolates originating from different pig farms, suggesting the transmission of tet(X4)-positive E. fergusonii between farms. In conclusion, our findings suggest that E. fergusonii strains in pigs are reservoirs of a transferable tet(X4) gene and provide insights into the tigecycline resistance mechanism as well as the diversity and complexity of the genetic context of tet(X4) in E. fergusonii.


Assuntos
Antibacterianos , Escherichia coli , Animais , Suínos , Humanos , Tigeciclina/farmacologia , Carbonil Cianeto m-Clorofenil Hidrazona , Filogenia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Plasmídeos , Testes de Sensibilidade Microbiana
16.
Proc Natl Acad Sci U S A ; 120(11): e2214324120, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36881626

RESUMO

Chemerin is a processed protein that acts on G protein-coupled receptors (GPCRs) for its chemotactic and adipokine activities. The biologically active chemerin (chemerin 21-157) results from proteolytic cleavage of prochemerin and uses its C-terminal peptide containing the sequence YFPGQFAFS for receptor activation. Here we report a high-resolution cryo-electron microscopy (cryo-EM) structure of human chemerin receptor 1 (CMKLR1) bound to the C-terminal nonapeptide of chemokine (C9) in complex with Gi proteins. C9 inserts its C terminus into the binding pocket and is stabilized through hydrophobic interactions involving its Y1, F2, F6, and F8, as well as polar interactions between G4, S9, and several amino acids lining the binding pocket of CMKLR1. Microsecond scale molecular dynamics simulations support a balanced force distribution across the whole ligand-receptor interface that enhances thermodynamic stability of the captured binding pose of C9. The C9 interaction with CMKLR1 is drastically different from chemokine recognition by chemokine receptors, which follow a two-site two-step model. In contrast, C9 takes an "S"-shaped pose in the binding pocket of CMKLR1 much like angiotensin II in the AT1 receptor. Our mutagenesis and functional analyses confirmed the cryo-EM structure and key residues in the binding pocket for these interactions. Our findings provide a structural basis for chemerin recognition by CMKLR1 for the established chemotactic and adipokine activities.


Assuntos
Adipocinas , Quimiocinas , Receptores de Quimiocinas , Humanos , Membrana Celular , Quimiocinas/metabolismo , Microscopia Crioeletrônica , Receptores de Quimiocinas/metabolismo
17.
Opt Express ; 31(5): 8884-8896, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36859994

RESUMO

Frequency selective surfaces (FSSs), modern artificial materials, show great potential in engineering applications due to their excellent frequency selection capabilities. In this paper, we introduce a flexible strain sensor based on FSS reflection characteristics, which can be well conformally attached to the surface of an object and bear mechanical deformation from a certain load. When the FSS structure changes, the original working frequency will be shifted. By measuring the difference in electromagnetic performance, the strain degree of the object can be monitored in real-time. In this study, we designed an FSS sensor with a working frequency of 31.4 GHz and amplitude that reaches -35 dB that exhibits favorable resonance properties in the Ka-band. The quality factor of FSS is 16.2, which indicates that the sensor has excellent sensing performance. The sensor was applied in the strain detection of a rocket engine case through statics and electromagnetic simulations. The analysis showed that the working frequency of the sensor shifted by approximately 200 MHz for 1.64% radial expansion of the engine case and the frequency shift exhibits an excellent linear relationship with the deformation in diverse loads, so it can be used for accurate strain detection of the case. Based on experiments, we carried out the uniaxial tensile test of the FSS sensor in this study. The sensor's sensitivity was 1.28 GHz/mm when the FSS was stretched by 0-3 mm in the test. Therefore, the FSS sensor has high sensitivity and strong mechanical properties, which verifies the practical value of the FSS structure designed in this paper. It has a broad development space in this field.

18.
Sci Rep ; 13(1): 5276, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37002275

RESUMO

Eight cases of bidirectional leader (BL) development in artificially triggered lightning flashes are reported with synchronous high-speed camera images and electric field signals. Based on optical progressing characteristics, the eight cases can be divided into three types: a reflection type, a discontinuity type, and an inducement type. For the reflection type, the tail of a dart leader may begin to extend backward when the leader's head reaches a branch point, or the top of the exploded triggering wire. For the discontinuity type, the initiation of a bidirectional leader below a decayed attempted leader may occur more than once preceding one return stroke. For the inducement type, the approach of another leader with the same polarity will turn a dart leader into a bidirectional leader. The reflection type and inducement type are first observed here. Two cases of the discontinuity type are observed, and both are multiple-bidirectional leaders observed for the first time. For the reflection type and inducement type, there are fluctuations in the electric field related to the BL development. The dissipation of the downward leader slows down the negative increase of the electric field. Once the BL development starts, the downward negative end of the BL moves towards the ground with the E-field negatively increasing. For the discontinuity type, the close electric field result shows no fluctuations. The BL development has a much longer duration than the other two BL types.

19.
Artigo em Inglês | MEDLINE | ID: mdl-36888898

RESUMO

Precise manipulation of skyrmion nucleation in microscale or nanoscale areas of thin films is a critical issue in developing high-efficient skyrmionic memories and logic devices. Presently, the mainstream controlling strategies focus on the application of external stimuli to tailor the intrinsic attributes of charge, spin, and lattice. This work reports effective skyrmion manipulation by controllably modifying the lattice defect through ion implantation, which is potentially compatible with large-scale integrated circuit technology. By implanting an appropriate dose of nitrogen ions into a Pt/Co/Ta multilayer film, the defect density was effectively enhanced to induce an apparent modulation of magnetic anisotropy, consequently boosting the skyrmion nucleation. Furthermore, the local control of skyrmions in microscale areas of the macroscopic film was realized by combining the ion implantation with micromachining technology, demonstrating a potential application in both binary storage and multistate storage. These findings provide a new approach to advancing the functionalization and application of skyrmionic devices.

20.
Foods ; 12(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36673425

RESUMO

Culinary circles have experienced a recent trend towards low-salt hotpot sauces. Here, changes in the physicochemical quality, flavour, and bacterial diversity of hotpot sauces with different salt concentrations were studied during storage. The results indicated that the peroxide and acid values of hotpot sauce increased gradually and that the quality began to deteriorate with storage. A storage temperature of 4 °C and salt concentration above 4.4% significantly reduced spoilage. The salt concentration had no significant effect on the flavour but extended storage resulted in significant differences in flavour reflected in the changes of sweet, sour, bitter, umami, aftertaste-A, abundance, organic sulphide, and alkanes. Significant differences were found in the bacterial composition between samples stored at different temperatures. Norank-f-o-Chloroplast was the main bacterium in the samples stored at low temperatures, which was beneficial for preservation. Bacillus was detected in 4.1% NaCl samples stored at 25 °C, directly promoting sauce spoilage and an unpleasant flavour. This bacterium signalled the spoilage of low-salt hotpot sauce stored at room temperature.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...