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1.
Bioinspir Biomim ; 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38848735

RESUMEN

Shoulder joints determine the motion range of the upper limb. Thus, the compact and well-stiffened spherical parallel mechanism (SPM) has emerged as the mainstream shoulder prosthesis design approaches. However, the SPM's moving pairs of redundant motions impose excessive constraints that limit its workspace. Therefore, amplifying the workspace of the SPM to cover the motion range required by human daily activities is a pressing problem in shoulder prosthesis design. To address this challenge, this study proposed a workspace amplification approach through the kinematic analysis of a symmetrically arranged 2 degrees of freedom (DoFs) passive mechanism, together with the designed and optimized 3-RRR SPM, to construct an anthropomorphic shoulder. The effectiveness and reliability of the proposed mechanism was verified through thorough analyses. Simulation and experiment results demonstrated that the workspace amplification mechanism (WAM) could significantly increase the maximum motion match index between the shoulder prosthesis and the daily workspace of the human shoulder from only 26.3% to 94.79%, solving the problem that the traditional SPM-based prostheses cannot satisfy the motion range required by daily activities. Moreover, the proposed mechanism has the potential to amplify the workspace of most parallel mechanisms with multiple DoFs after proper modification.

2.
J Magn Reson Imaging ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38874990

RESUMEN

BACKGROUND: Self-body satisfaction is considered a psychological factor for exercise dependence (EXD). However, the potential neuropsychological mechanisms underlying this association remain unclear. PURPOSE: To investigate the role of white matter microstructure in the association between body satisfaction and EXD. STUDY TYPE: Prospective. POPULATION: One hundred eight regular exercisers (age 22.11 ± 2.62 years; 58 female). FIELD STRENGTH/SEQUENCE: 3.0 Tesla; diffusion-weighted echo planar imaging with 30 directions. ASSESSMENT: The Body Shape Satisfaction (BSS) and Exercise Dependence Scale (EDS); whole-brain tract-based spatial statistics (TBSS) and correlational tractography analyses; average fractional anisotropy (FA) and quantitative anisotropy (QA) values of obtained tracts. STATISTICAL TESTS: The whole-brain regression model, mediation analysis, and simple slope analysis. P values <0.05 were defined as statistically significant. RESULTS: The BSS and EDS scores were 37.33 ± 6.32 and 68.22 ± 13.88, respectively. TBSS showed negative correlations between EDS and FA values in the bilateral corticospinal tract (CST, r = -0.41), right cingulum (r = -0.41), and left superior thalamic radiation (STR, r = -0.50). Correlational tractography showed negative associations between EDS and QA values of the left inferior frontal occipital fasciculus (r = -0.35), STR (r = -0.42), CST (r = -0.31), and right cingulum (r = -0.28). The FA values, rather than QA values, mediated the BSS-EDS association (indirect effects = 0.30). The BSS was significantly associated with the EDS score at both low (ß = 1.02) and high (ß = 0.43) levels of FA value, while the association was significant only at the high level of QA value (ß = 1.26). DATA CONCLUSION: EXD was correlated with white matter in frontal-subcortical and sensorimotor networks, and these tracts mediated the body satisfaction-EXD association. White matter microstructure could be a promising neural signature for understanding the underlying neuropsychological mechanisms of EXD. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

3.
Opt Express ; 32(11): 18441-18452, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38858999

RESUMEN

Imaging the complex dynamics of micro-vibrations plays a fundamental role in the investigation of microelectromechanical systems (MEMS). However, it remains a challenge for achieving both a wide bandwidth and a low noise due to the high photodetector noise and electromagnetic interference at GHz frequencies. Here, we propose a pulsed laser interferometry system with an adaptable switch to image GHz vibrations based on stroboscopic mixing, while measuring lower-frequency vibrations based on the homodyne scheme. The noise power spectral density is shown in both regions from DC to 10 GHz with an average noise down to 30.8 fm/√Hz at GHz frequencies, which holds the highest resolution to the best of our knowledge. Vibrational amplitude and phase mappings of a kHz comb-drive resonator, a GHz piezoelectric transducer, and a GHz film bulk acoustic resonator are presented with animated visualizations and k-space analysis, paving a new paradigm for the first time to image and analyze various MEMS devices of a bandwidth spanning 10 orders of magnitude.

4.
Opt Express ; 32(11): 20066-20079, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38859124

RESUMEN

In the field of machine vision, depth segmentation plays a crucial role in dividing targets into different regions based on abrupt changes in depth. Phase-shifting depth segmentation is a technique that extracts singular points to form segmentation lines by leveraging the phase-shifting invariance of singular points in different wrapped phase maps. This makes it immune to color, texture, and camera exposure. However, current phase-shifting depth segmentation techniques face challenges in the precision of segmentation. To overcome this issue, this paper proposes a singular points extraction technique by constructing a more comprehensive threshold with the help of the minimum period of the phase map. Taking full advantage of the proposed technique, mean-value points and order singular points are accurately filtered out, and the integrity of segmentation lines in high-curvature regions can be guaranteed. During optimization processing, the precision of segmentation is improved by employing a low-cost morphology-based optimization model. Simulation results demonstrate the segmentation accuracy reaches up to 98.58% even in a noisy condition. Experimental results on different objects indicate that the proposed method exhibits good generalization and robustness.

5.
Org Lett ; 26(21): 4422-4426, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38767940

RESUMEN

Catalytic cyclization via dual C-H bond activation has evolved as a powerful strategy for building bi- and polycyclic molecules. Herein, a palladium-catalyzed annulation of tertiary anilines with 3-butenoic acid via N-α-C(sp3)-H and ortho-C(sp2)-H activation is described. The remarkable characteristics of this reaction include excellent diastereoselectivity, broad substrate scope, and good tolerance for some highly sensitive groups. In addition, the KIE experiment suggested that the C-H bond abscission is not the turnover-limiting step.

6.
IEEE Trans Cybern ; PP2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748528

RESUMEN

In gene regulatory networks (GRNs), it is important to model gene regulation based on a priori information and experimental data. As a useful mathematical model, probabilistic Boolean networks (PBNs) have been widely applied in GRNs. This article addresses the optimal reconstruction problem of PBNs based on several priori Boolean functions and sampled data. When all candidate Boolean functions are known in advance, the optimal reconstruction problem is reformulated into an optimization problem. This problem can be well solved by a recurrent neural network approach which decreases the computational cost. When parts of candidate Boolean functions are known in advance, necessary and sufficient conditions are provided for the reconstruction of PBNs. In this case, two types of reconstruction problems are further proposed: one is aimed at minimizing the number of reconstructed Boolean functions, and the other one is aimed at maximizing the selection probability of the main dynamics under noises. At last, examples in GRNs are elaborated to demonstrate the effectiveness of the main results.

7.
Nanomicro Lett ; 16(1): 191, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38700650

RESUMEN

Low-temperature processed electron transport layer (ETL) of TiO2 that is widely used in planar perovskite solar cells (PSCs) has inherent low carrier mobility, resulting in insufficient photogenerated electron transport and thus recombination loss at buried interface. Herein, we demonstrate an effective strategy of laser embedding of p-n homojunctions in the TiO2 ETL to accelerate electron transport in PSCs, through localized build-in electric fields that enables boosted electron mobility by two orders of magnitude. Such embedding is found significantly helpful for not only the enhanced crystallization quality of TiO2 ETL, but the fabrication of perovskite films with larger-grain and the less-trap-states. The embedded p-n homojunction enables also the modulation of interfacial energy level between perovskite layers and ETLs, favoring for the reduced voltage deficit of PSCs. Benefiting from these merits, the formamidinium lead iodide (FAPbI3) PSCs employing such ETLs deliver a champion efficiency of 25.50%, along with much-improved device stability under harsh conditions, i.e., maintain over 95% of their initial efficiency after operation at maximum power point under continuous heat and illumination for 500 h, as well as mixed-cation PSCs with a champion efficiency of 22.02% and over 3000 h of ambient storage under humidity stability of 40%. Present study offers new possibilities of regulating charge transport layers via p-n homojunction embedding for high performance optoelectronics.

8.
Front Psychol ; 15: 1349918, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38655217

RESUMEN

Introduction: Self-efficacy (SE), defined as an individual's belief in their ability to complete a task, is linked to top-down attentional control, influencing motor performance in sports. Although the behavioral effects of SE are well-documented, there is a lack of research on the mechanisms through which SE affects sports performance. Our research aims to elucidate the neurophysiological mechanisms that underlie the impact of self-efficacy on sports performance. Specifically, we intend to explore the effects of low and high SE on frontal midline theta (Fmθ) activity, associated with sustained top-down attention, and on motor performance. Methods: We recruited thirty-four professional golfers to perform 60 putts, during which their electroencephalographic activity was monitored. SE levels were assessed using a visual analog scale from 0 to 10 before each putt, with scores categorized into higher or lower SE based on each golfer's individual average score. Results: Paired t-tests indicated that trials with higher SE scores had a higher putting success rate than those with lower SE scores (53.3% vs. 46.7%). Furthermore, trials associated with higher SE scores exhibited lower Fmθ activity compared to those with lower SE scores (4.49 vs. 5.18). Discussion: Our results suggest that higher SE is associated with reduced top-down attentional control, leading to improved putting performance. These findings support Bandura's theory of SE, which suggests that the effects of efficacy beliefs are mediated by cognitive, motivational, emotional, and decision-making processes. This study sheds light on the intermediate processes of SE by examining its impact on the anticipation of outcomes, sports performance, and attentional control prior to putting.

9.
Adv Sci (Weinh) ; : e2308835, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38647364

RESUMEN

Soft material-based robots, known for their safety and compliance, are expected to play an irreplaceable role in human-robot collaboration. However, this expectation is far from real industrial applications due to their complex programmability and poor motion precision, brought by the super elasticity and large hysteresis of soft materials. Here, a soft collaborative robot (Soft Co-bot) with intuitive and easy programming by contact-based drag teaching, and also with exceptional motion repeatability (< 0.30% of body length) and ultra-low hysteresis (< 2.0%) is reported. Such an unprecedented capability is achieved by a biomimetic antagonistic design within a pneumatic soft robot, in which cables are threaded to servo motors through tension sensors to form a self-sensing system, thus providing both precise actuation and dragging-aware collaboration. Hence, the Soft Co-bots can be first taught by human drag and then precisely repeat various tasks on their own, such as electronics assembling, machine tool installation, etc. The proposed Soft Co-bots exhibit a high potential for safe and intuitive human-robot collaboration in unstructured environments, promoting the immediate practical application of soft robots.

10.
Eur J Radiol ; 175: 111398, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38579540

RESUMEN

PURPOSE: This retrospective study aimed to investigate the effectiveness and safety of bronchial arterial chemoembolization with drug-eluting beads (DEB-BACE) plus chemotherapy versus chemotherapy alone in patients with stage III and IV lung squamous cell carcinoma (LSCC) who are not appropriate candidates for radiochemotherapy. MATERIALS AND METHODS: In this retrospective analysis, we screened all adult patients undergoing either DEB-BACE plus chemotherapy or chemotherapy alone for stage III or IV LCSS at authors' center from January 2018 to August 2021. Each 21-day chemotherapy cycle consisted of intravenous injection of gemcitabine (1.0 g/m2) on days 1 and 8 and cisplatin 75 (mg/m2) on day 1. The planned cycles were 4. DEB-BACE consisted of microcatheter infusion of CalliSpheres beads carrying cisplatin (75 mg/m2) and gemcitabine (1.0 g/m2), at 3 weeks prior to chemotherapy. The primary outcome was overall survival (OS). The secondary outcomes included progression-free survival (PFS), pulmonary response, and adverse events (AEs). RESULTS: The final analysis included 95 patients in the chemotherapy group and 41 patients in the combination treatment group. The median OS was 14 months (95 % CI 11.0-17.0) in the chemotherapy group and 19 months (95 % CI 18.0-24.0) in the combination group (P = 0.015). In multivariate Cox regression analysis, DEB-BACE plus chemotherapy was associated with lower risk of death versus chemotherapy only (HR 0.16, 95 % CI 0.05-0.52; log rank test P = 0.003). The median PFS was 6 months (95 % CI 4.0-7.0) in the chemotherapy group and 8 months (95 % CI 6.0-8.0) in the combination group (P = 0.015). The pulmonary objective response rate (ORR) and disease control rate (DCR) were 48.4 % and 62.1 % in chemotherapy group versus 82.9 % and 90.2 % in combination group (P < 0.001 and = 0.001, respectively). AEs occurred in 133 patients (97.8 %). The rate of bone marrow suppression was 48.4 % (46/95) in the chemotherapy group versus 7.3 % (3/41) in the combination group (P < 0.001). CONCLUSION: Compared with chemotherapy alone, DEB-BACE plus chemotherapy was associated with longer survival outcomes and lower rate of bone marrow suppression.


Asunto(s)
Arterias Bronquiales , Quimioembolización Terapéutica , Cisplatino , Desoxicitidina , Gemcitabina , Neoplasias Pulmonares , Estadificación de Neoplasias , Humanos , Masculino , Femenino , Estudios Retrospectivos , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Persona de Mediana Edad , Cisplatino/administración & dosificación , Desoxicitidina/análogos & derivados , Desoxicitidina/administración & dosificación , Quimioembolización Terapéutica/métodos , Anciano , Resultado del Tratamiento , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/tratamiento farmacológico
11.
IEEE Trans Med Robot Bionics ; 6(1): 135-145, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38304756

RESUMEN

Subretinal injection methods and other procedures for treating retinal conditions and diseases (many considered incurable) have been limited in scope due to limited human motor control. This study demonstrates the next generation, cooperatively controlled Steady-Hand Eye Robot (SHER 3.0), a precise and intuitive-to-use robotic platform achieving clinical standards for targeting accuracy and resolution for subretinal injections. The system design and basic kinematics are reported and a deflection model for the incorporated delta stage and validation experiments are presented. This model optimizes the delta stage parameters, maximizing the global conditioning index and minimizing torsional compliance. Five tests measuring accuracy, repeatability, and deflection show the optimized stage design achieves a tip accuracy of < 30 µm, tip repeatability of 9.3 µm and 0.02°, and deflections between 20-350 µm/N. Future work will use updated control models to refine tip positioning outcomes and will be tested on in vivo animal models.

12.
Nutr Cancer ; 76(4): 379-392, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38332562

RESUMEN

Idebenone, a mitochondrial regulator, has exhibited anti-cancer activity in neurogenic and prostate tumor cells; however, its efficacy and specific targets in the treatment of triple-negative breast cancer (TNBC) remain unclear. This study aims to evaluate the potential of Idebenone as a therapeutic agent for TNBC. TNBC cell lines and Xenograft mouse models were used to assess the effect of Idebenone on TNBC both in vitro and in vivo. To investigate the underlying mechanism of Idebenone's effect on TNBC, cell viability assay, transwell invasion assay, cell cycle analysis, apoptosis assay, mitochondrial membrane potential assay, immunofluorescence staining, and transcriptome sequencing were utilized. The results showed that Idebenone impeded the proliferation, colony formation, migration, and invasion of TNBC cells, suppressed apoptosis, and halted the cell cycle in the G2/M phase. The inhibitory effect of Idebenone on TNBC was associated with the GADD45/CyclinB/CDK1 signaling pathway. By disrupting the mitochondrial membrane potential (MMP) and promoting mitophagy, Idebenone promoted cell autophagy through the AMPK/mTOR pathway, thus further suppressing the proliferation of TNBC cells. Furthermore, we found that Idebenone inhibited the development of TNBC in vivo. In conclusion, Idebenone may be a promising therapeutic option for TNBC as it is capable of inducing autophagy and apoptosis.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Ubiquinona/análogos & derivados , Humanos , Animales , Ratones , Neoplasias de la Mama Triple Negativas/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Proliferación Celular , Línea Celular Tumoral , Transducción de Señal , Modelos Animales de Enfermedad
13.
Small ; : e2310997, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38353064

RESUMEN

Sodium-ion batteries (SIBs) are potential candidates for large energy storage usage because of the natural abundance and cheap sodium. Nevertheless, improving the energy density and cycling steadiness of SIB cathodes remains a challenge. In this work, F-doping Na3 Al2/3 V4/3 (PO4 )3 (NAVP) microspheres (Na3 Al2/3 V4/3 (PO4 )2.9 F0.3 (NAVPF)) are synthesized via spray drying and investigated as SIB cathodes. XRD and Rietveld refinement reveal expanded lattice parameters for NAVPF compared to the undoped sample, and the successful cation doping into the Na superionic conductor (NASICON) framework improves Na+ diffusion channels. The NAVPF delivers an ultrahigh capacity of 148 mAh g-1 at 100 mA g-1 with 90.8% retention after 200 cycles, enabled by the activation of V2+ /V5+ multielectron reaction. Notably, NAVPF delivers an ultrahigh rate performance, with a discharge capacity of 83.6 mAh g-1 at 5000 mA g-1 . In situ XRD demonstrates solid-solution reactions occurred during charge-discharge of NAVPF without two-phase reactions, indicating enhanced structural stability after F-doped. The full cell with NAVPF cathode and Na+ preintercalated hard carbon anode shows a large discharge capacity of 100 mAh g-1 at 100 mA g-1 with 80.2% retention after 100 cycles. This anion doping strategy creates a promising SIB cathode candidate for future high-energy-density energy storage applications.

14.
Gut Microbes ; 16(1): 2316575, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38381494

RESUMEN

Intestinal microbiota dysbiosis and metabolic disruption are considered essential characteristics in inflammatory bowel disorders (IBD). Reasonable butyrate supplementation can help patients regulate intestinal flora structure and promote mucosal repair. Here, to restore microbiota homeostasis and butyrate levels in the patient's intestines, we modified the genome of Saccharomyces cerevisiae to produce butyrate. We precisely regulated the relevant metabolic pathways to enable the yeast to produce sufficient butyrate in the intestine with uneven oxygen distribution. A series of engineered strains with different butyrate synthesis abilities was constructed to meet the needs of different patients, and the strongest can reach 1.8 g/L title of butyrate. Next, this series of strains was used to co-cultivate with gut microbiota collected from patients with mild-to-moderate ulcerative colitis. After receiving treatment with engineered strains, the gut microbiota and the butyrate content have been regulated to varying degrees depending on the synthetic ability of the strain. The abundance of probiotics such as Bifidobacterium and Lactobacillus increased, while the abundance of harmful bacteria like Candidatus Bacilloplasma decreased. Meanwhile, the series of butyrate-producing yeast significantly improved trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice by restoring butyrate content. Among the series of engineered yeasts, the strain with the second-highest butyrate synthesis ability showed the most significant regulatory and the best therapeutic effect on the gut microbiota from IBD patients and the colitis mouse model. This study confirmed the existence of a therapeutic window for IBD treatment by supplementing butyrate, and it is necessary to restore butyrate levels according to the actual situation of patients to restore intestinal flora.


Asunto(s)
Colitis , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Humanos , Animales , Ratones , Saccharomyces cerevisiae/genética , Butiratos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Disbiosis , Suplementos Dietéticos
16.
Neuroimage ; 287: 120520, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38242489

RESUMEN

The human ventral occipito-temporal cortex (VOTC) has evolved into specialized regions that process specific categories, such as words, tools, and animals. The formation of these areas is driven by bottom-up visual and top-down nonvisual experiences. However, the specific mechanisms through which top-down nonvisual experiences modulate category-specific regions in the VOTC are still unknown. To address this question, we conducted a study in which participants were trained for approximately 13 h to associate three sets of novel meaningless figures with different top-down nonvisual features: the wordlike category with word features, the non-wordlike category with nonword features, and the visual familiarity condition with no nonvisual features. Pre- and post-training functional MRI (fMRI) experiments were used to measure brain activity during stimulus presentation. Our results revealed that training induced a categorical preference for the two training categories within the VOTC. Moreover, the locations of two training category-specific regions exhibited a notable overlap. Remarkably, within the overlapping category-specific region, training resulted in a dissociation in activation intensity and pattern between the two training categories. These findings provide important insights into how different nonvisual categorical information is encoded in the human VOTC.


Asunto(s)
Aprendizaje , Lóbulo Temporal , Humanos , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiología , Reconocimiento en Psicología , Imagen por Resonancia Magnética/métodos , Mapeo Encefálico/métodos , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos
17.
Medicine (Baltimore) ; 103(2): e36736, 2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38215097

RESUMEN

INTRODUCTION: Lymphoma can appear in all parts of the body and present with different symptoms. However, bronchial lymphoma is rare and can be misdiagnosed as airway malignancy or lung disease.Patient: An older adult woman with tracheal lymphoma experienced severe breathing difficulties, and chest computed tomography indicated severe narrowing of the airway. She did not respond to repeated antibiotic treatment, and she was eventually diagnosed with lymphoma based on pathology after surgical removal of the tumor. DIAGNOSIS: The patient received a diagnosis of thoracic tracheal stenosis due to intratracheal inflammatory granulomatous lesions or a tumor. INTERVENTIONS: Treatment involved the use of a high-frequency electrotome, freezing, and argon plasma coagulation. OUTCOMES: The patient reported improvements in dyspnea, cough, and other symptoms after the operation. The pathological results confirmed follicular lymphoma. Reexamination by fiberbronchoscopy indicated that the degree of stenosis in the middle and upper tracheal segments was significantly reduced following interventional therapy. CONCLUSION: Endoscopic interventional therapy can be an effective treatment for tracheal lymphoma.


Asunto(s)
Neoplasias de los Bronquios , Linfoma , Neoplasias de la Tráquea , Estenosis Traqueal , Femenino , Humanos , Anciano , Broncoscopía/métodos , Tráquea , Estenosis Traqueal/etiología , Estenosis Traqueal/cirugía , Neoplasias de la Tráquea/diagnóstico , Neoplasias de la Tráquea/cirugía , Linfoma/diagnóstico , Linfoma/cirugía , Disnea/etiología
18.
Nat Immunol ; 25(2): 307-315, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38182667

RESUMEN

The global outbreak of the mpox virus (MPXV) in 2022 highlights the urgent need for safer and more accessible new-generation vaccines. Here, we used a structure-guided multi-antigen fusion strategy to design a 'two-in-one' immunogen based on the single-chain dimeric MPXV extracellular enveloped virus antigen A35 bivalently fused with the intracellular mature virus antigen M1, called DAM. DAM preserved the natural epitope configuration of both components and showed stronger A35-specific and M1-specific antibody responses and in vivo protective efficacy against vaccinia virus (VACV) compared to co-immunization strategies. The MPXV-specific neutralizing antibodies elicited by DAM were 28 times higher than those induced by live VACV vaccine. Aluminum-adjuvanted DAM vaccines protected mice from a lethal VACV challenge with a safety profile, and pilot-scale production confirmed the high yield and purity of DAM. Thus, our study provides innovative insights and an immunogen candidate for the development of alternative vaccines against MPXV and other orthopoxviruses.


Asunto(s)
Monkeypox virus , Vacunas , Animales , Ratones , Proteínas del Envoltorio Viral , Anticuerpos Antivirales , Virus Vaccinia , Antígenos Virales , Inmunidad
19.
Soft Matter ; 20(6): 1173-1185, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38164656

RESUMEN

Glycyrrhizic acid (GA), a naturally derived food-grade saponin molecule, is a promising alternative to synthetic surfactants for stabilizing multiphase systems including emulsions and foams, due to its biological activity and surface-active properties. Understanding the interfacial behavior of GA, particularly in relation to its complex self-assembly behaviors in water induced by multiple environmental stimuli, is crucial to its application in multiphase systems. In this study, we comprehensively investigate the interfacial structure and rheological properties of GA systems, as a function of pH and temperature, through Langmuir-Blodgett films combined with atomic force microscopy, interfacial particle tracking, adsorption kinetics, stress-relaxation behavior and interfacial dilatational rheology. The variation of solution pH provokes pronounced changes in the interfacial properties of GA. At pH 2 and 4, GA fibril aggregates/fibrils adsorb rapidly, followed by rearrangement into large lamellar and rod-like structures, forming a loose and heterogeneous fibrous network at the interface, which exhibit a stretchable gel-like behavior. In contrast, GA at pH 6 and 8, featuring micelles or monomers in solutions, adsorb slowly to the interface and re-assemble partially into small micelle-like or irregular structures, which lead to a dense and homogeneous interfacial layer with stiffer glassy-like responses. With successively elevated temperature, the GA structures (pH 4) at the interface break into smaller fragments and further adsorption is promoted. Upon cooling, the interfacial tension of GA further decreases and a highly elastic interfacial layer may be formed. The diverse GA assemblies in bulk solution impart them with rich and intriguing interfacial behaviors, which may provide valuable mechanistic insights for the development of novel edible soft matter stabilized by GA.


Asunto(s)
Ácido Glicirrínico , Agua , Tensión Superficial , Propiedades de Superficie , Reología , Emulsiones , Agua/química , Adsorción
20.
Plant Physiol ; 194(3): 1794-1814, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38036294

RESUMEN

Bud dormancy is an important physiological process during winter. Its release requires a certain period of chilling. In pear (Pyrus pyrifolia), the abscisic acid (ABA)-induced expression of DORMANCY-ASSOCIATED MADS-box (DAM) genes represses bud break, whereas exogenous gibberellin (GA) promotes dormancy release. However, with the exception of ABA and GA, the regulatory effects of phytohormones on dormancy remain largely uncharacterized. In this study, we confirmed brassinosteroids (BRs) and jasmonic acid (JA) contribute to pear bud dormancy release. If chilling accumulation is insufficient, both 24-epibrassinolide (EBR) and methyl jasmonic acid (MeJA) can promote pear bud break, implying that they positively regulate dormancy release. BRASSINAZOLE RESISTANT 2 (BZR2), which is a BR-responsive transcription factor, inhibited PpyDAM3 expression and accelerated pear bud break. The transient overexpression of PpyBZR2 increased endogenous GA, JA, and JA-Ile levels. In addition, the direct interaction between PpyBZR2 and MYELOCYTOMATOSIS 2 (PpyMYC2) enhanced the PpyMYC2-mediated activation of Gibberellin 20-oxidase genes PpyGA20OX1L1 and PpyGA20OX2L2 transcription, thereby increasing GA3 contents and accelerating pear bud dormancy release. Interestingly, treatment with 5 µm MeJA increased the bud break rate, while also enhancing PpyMYC2-activated PpyGA20OX expression and increasing GA3,4 contents. The 100 µm MeJA treatment decreased the PpyMYC2-mediated activation of the PpyGA20OX1L1 and PpyGA20OX2L2 promoters and suppressed the inhibitory effect of PpyBZR2 on PpyDAM3 transcription, ultimately inhibiting pear bud break. In summary, our data provide insights into the crosstalk between the BR and JA signaling pathways that regulate the BZR2/MYC2-mediated pathway in the pear dormancy release process.


Asunto(s)
Brasinoesteroides , Ciclopentanos , Oxilipinas , Pyrus , Triazoles , Brasinoesteroides/farmacología , Pyrus/genética , Reguladores del Crecimiento de las Plantas/farmacología , Ácido Abscísico
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