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1.
Bioact Mater ; 20: 93-110, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35633874

RESUMO

The revolutionary role of tissue adhesives in wound closure, tissue sealing, and bleeding control necessitates the development of multifunctional materials capable of effective and scarless healing. In contrast to the use of traditionally utilized toxic oxidative crosslinking initiators (exemplified by sodium periodate and silver nitrate), herein, the natural polyphenolic compound tannic acid (TA) was used to achieve near instantaneous (<25s), hydrogen bond mediated gelation of citrate-based mussel-inspired bioadhesives combining anti-oxidant, anti-inflammatory, and antimicrobial activities (3A-TCMBAs). The resulting materials were self-healing and possessed low swelling ratios (<60%) as well as considerable mechanical strength (up to ∼1.0 MPa), elasticity (elongation ∼2700%), and adhesion (up to 40 kPa). The 3A-TCMBAs showed strong in vitro and in vivo anti-oxidant ability, favorable cytocompatibility and cell migration, as well as photothermal antimicrobial activity against both Staphylococcus aureus and Escherichia coli (>90% bacterial death upon near-infrared (NIR) irradiation). In vivo evaluation in both an infected full-thickness skin wound model and a rat skin incision model demonstrated that 3A-TCMBAs + NIR treatment could promote wound closure and collagen deposition and improve the collagen I/III ratio on wound sites while simultaneously inhibiting the expression of pro-inflammatory cytokines. Further, phased angiogenesis was observed via promotion in the early wound closure phases followed by inhibition and triggering of degradation & remodeling of the extracellular matrix (ECM) in the late stage (supported by phased CD31 (platelet endothelial cell adhesion molecule-1) PDGF (platelet-derived growth factor) and VEGF (vascular endothelial growth factor) expression as well as elevated matrix metalloprotein-9 (MMP-9) expression on day 21), resulting in scarless wound healing. The significant convergence of material and bioactive properties elucidated above warrant further exploration of 3A-TCMBAs as a significant, new class of bioadhesive.

2.
Bioact Mater ; 19: 360-375, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35574051

RESUMO

The high demand for rapid wound healing has spurred the development of multifunctional and smart bioadhesives with strong bioadhesion, antibacterial effect, real-time sensing, wireless communication, and on-demand treatment capabilities. Bioadhesives with bio-inspired structures and chemicals have shown unprecedented adhesion strengths, as well as tunable optical, electrical, and bio-dissolvable properties. Accelerated wound healing has been achieved via directly released antibacterial and growth factors, material or drug-induced host immune responses, and delivery of curative cells. Most recently, the integration of biosensing and treatment modules with wireless units in a closed-loop system yielded smart bioadhesives, allowing real-time sensing of the physiological conditions (e.g., pH, temperature, uric acid, glucose, and cytokine) with iterative feedback for drastically enhanced, stage-specific wound healing by triggering drug delivery and treatment to avoid infection or prolonged inflammation. Despite rapid advances in the burgeoning field, challenges still exist in the design and fabrication of integrated systems, particularly for chronic wounds, presenting significant opportunities for the future development of next-generation smart materials and systems.

3.
Bioact Mater ; 20: 598-609, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35846837

RESUMO

There is a continuing need for artificial bone substitutes for bone repair and reconstruction, Magnesium phosphate bone cement (MPC) has exceptional degradable properties and exhibits promising biocompatibility. However, its mechanical strength needs improved and its low osteo-inductive potential limits its therapeutic application in bone regeneration. We functionally modified MPC by using a polymeric carboxymethyl chitosan-sodium alginate (CMCS/SA) gel network. This had the advantages of: improved compressive strength, ease of handling, and an optimized interface for bioactive bone in-growth. The new composites with 2% CMCS/SA showed the most favorable physicochemical properties, including mechanical strength, wash-out resistance, setting time, injectable time and heat release. Biologically, the composite promoted the attachment and proliferation of osteoblast cells. It was also found to induce osteogenic differentiation in vitro, as verified by expression of osteogenic markers. In terms of molecular mechanisms, data showed that new bone cement activated the Wnt pathway through inhibition of the phosphorylation of ß-catenin, which is dependent on focal adhesion kinase. Through micro-computed tomography and histological analysis, we found that the MPC-CMCS/SA scaffolds, compared with MPC alone, showed increased bone regeneration in a rat calvarial defect model. Overall, our study suggested that the novel composite had potential to help repair critical bone defects in clinical practice.

4.
Artigo em Inglês | MEDLINE | ID: mdl-36076020

RESUMO

Serum amyloid P component (SAP) is a universal constituent of human amyloid deposits including those in Alzheimer's disease. SAP has been observed to be elevated in patients with depression, and higher SAP levels are associated with better response to the antidepressant escitalopram. The mechanisms underlying these clinical observations remain unclear. We examined the effect of SAP on serotonin transporter (SERT) expression and localization using Western blot, confocal microscopy, and positron emission tomography with the radioligand [11C]DASB. We also investigated the effect of SAP on treatment response to escitalopram in mice with the forced swim test (FST), a classical behaviour paradigm to assess antidepressant effects. SAP reduced [11C]DASB binding as an index of SERT levels, consistent with Western blots showing decreased total SAP protein because of increased protein degradation. In conjunction with the global decrease in SERT levels, SAP also promotes VAMP-2 mediated SERT membrane insertion. SAP levels are correlated with behavioural despair and SSRI treatment response in mice with FST. In MDD patients, the SAP and membrane SERT levels are correlated with response to SSRI treatment. SAP has complex effects on SERT levels and localization, thereby modulating the effect of SSRIs, which could partially explain clinical variability in antidepressant treatment response. These results add to our understanding of the mechanism for antidepressant drug action, and with further work could be of clinical utility.

5.
Med Oncol ; 39(12): 182, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071287

RESUMO

Glioblastoma multiforme (GBM) and Alzheimer's disease (AD) are two major diseases in the nervous system with a similar peak age of onset, which has the typical characteristics of high cost, difficult treatment, and poor prognosis. Epidemiological studies and a few molecular biological studies have hinted at an opposite relationship between AD and GBM. However, there are few studies on their reverse relationship, and the regulatory mechanism is still unclear, indicating that further systematic research is urgently needed. Our study firstly employs advanced bioinformatics methods to explore the inverse relationship between them and find various target drugs. We obtained the gene expression dataset from public databases (GEO, TCGA, and GTEx). Then, we identified 122 differentially expressed genes (DEGs) of AD and GBM. Four significant gene modules were identified through protein-protein interaction (PPI) and module construction, and 13 hub genes were found using cytoHubba. We constructed co-expression networks and found various target drugs through these hub genes. Functional enrichment analysis revealed that the AMPK pathway, cell cycle, and cellular senescence play important roles in AD and GBM. Our study may provide a potential direction for studying the opposite molecular mechanism of AD and GBM in the future.


Assuntos
Doença de Alzheimer , Glioblastoma , Doença de Alzheimer/genética , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos
6.
Hortic Res ; 9: uhac140, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072835

RESUMO

Isatis indigotica accumulates several active substances, including C-glycosylflavonoids, which have important pharmacological activities and health benefits. However, enzymes catalyzing the methylation step of C-glycosylflavonoids in I. indigotica remain unknown. In this study, three O-methyltransferases (OMTs) were identified from I. indigotica that have the capacity for O-methylation of the C-glycosylflavonoid isoorientin. The Type II OMTs IiOMT1 and IiOMT2 efficiently catalyze isoorientin to form isoscoparin, and decorate one of the aromatic vicinal hydroxyl groups on flavones and methylate the C6, C8, and 3'-hydroxyl positions to form oroxylin A, wogonin, and chrysoeriol, respectively. However, the Type I OMT IiOMT3 exhibited broader substrate promiscuity and methylated the C7 and 3'-hydroxyl positions of flavonoids. Further site-directed mutagenesis studies demonstrated that five amino acids of IiOMT1/IiOMT2 (D121/D100, D173/D149, A174/A150R, N200/N176, and D248/D233) were critical residues for their catalytic activity. Additionally, only transient overexpression of Type II OMTs IiOMT1 and IiOMT2 in Nicotiana benthamiana significantly increased isoscoparin accumulation, indicating that the Type II OMTs IiOMT1 and IiOMT2 could catalyze the methylation step of C-glycosylflavonoid, isoorientin at the 3'-hydroxyl position. This study provides insights into the biosynthesis of methylated C-glycosylflavonoids, and IiOMTs could be promising catalysts in the synthesis of bioactive compounds.

7.
J Pharmacol Sci ; 150(2): 110-122, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055749

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases, and there are no effective drugs available so far. Lactucin and Lactucopicrin belong to sesquiterpene lactones and are extracted from Cichorium glandulosum Boiss. et Huet (CG) possesses multiple biopharmacological activities. However, the therapeutic effects of both Lactucin and Lactucopicrin on many diseases and their underlying mechanisms remain largely unknown. Here, we analyzed the both natural compounds hypolipidemic effects on FFA-induced HepG2 cells and their potential mechanisms based on transcriptomics and experimental tests. Our results indicated that Lactucin (10 µM) and Lactucopicrin (20 µM) remarkably reduced TG accumulation. Transcriptomics analysis identified 1960, 1645, and 1791 differentially expressed genes (DEGs) and obtained 611 and 635 specific genes in different comparisons, respectively. The enrichment analysis and experimental validations (RT-qPCR and Western Blot) showed that their hypolipidemic activities were most probably exerted via regulating numerous key DEGs involved in lipid metabolism. Taken together, both Lactucin and Lactucopicrin may represent potent hepatoprotective agents. Both of them exhibited therapeutic effects against liver diseases such as NAFLD by regulating multi-gene and proteins like HADHA, ADAM17, SQSTM1, and GBA and modulating multi-pathways like fatty acid oxidation metabolic signaling.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Sesquiterpenos , Células Hep G2 , Humanos , Lactonas/farmacologia , Lactonas/uso terapêutico , Metabolismo dos Lipídeos/genética , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Forbóis , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêutico
8.
Front Public Health ; 10: 837238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36062111

RESUMO

With the rapid development of digital information technology, life has become more convenient for people; however, the digital divide for the elderly was even more serious, so they became a forgotten group in the internet age over time. Residents' demand for healthcare is rising, but the wisdom healthcare service supported by digital information technology is less acceptable to the elderly due to the digital divide. Based on the knowledge gap theory and combining the value perception and satisfaction model, this study explores the influence of the digital divide for the elderly on wisdom healthcare satisfaction and takes the perceived value of wisdom healthcare as a mediator, and artificial intelligence and big data as moderators into the research framework. Based on the data of 1,052 elderly people in China, the results show that the digital divide for the elderly has a negative influence on wisdom healthcare satisfaction and perceived value. Moreover, it is found that wisdom healthcare perception value mediated the relationship between the digital divide for the elderly and the wisdom healthcare satisfaction, which enhances the negative effect of the digital divide for the elderly on wisdom healthcare satisfaction. Furthermore, the moderating effect of artificial intelligence and big data on the relationship between the digital divide for the elderly and the perceived value of wisdom healthcare is opposite to that between the perceived value of wisdom healthcare and wisdom healthcare satisfaction. Therefore, this study has a reference value for the development and optimization of smart medical industry.


Assuntos
Big Data , Exclusão Digital , Idoso , Inteligência Artificial , Atenção à Saúde , Humanos , Indústrias
9.
Clin Nucl Med ; 47(10): 885-887, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36067086

RESUMO

ABSTRACT: Intraventricular metastasis from extracranial tumor is rare. We describe MRI and 68Ga-FAPI-04 PET/CT findings in a case of histologically proved solitary choroid plexus metastasis from clear cell renal cell carcinoma. The tumor showed remarkable enhancement on MRI and increased FAPI uptake with high tumor-to-background activity ratio on PET/CT. This case indicates FAPI PET may be useful for detection of intraventricular metastasis from renal cell carcinoma.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/patologia , Plexo Corióideo/patologia , Fluordesoxiglucose F18 , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Quinolinas
10.
Phys Med Biol ; 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36070774

RESUMO

OBJECTIVE: Radiation therapy requires a precise target location. However, respiratory motion increases the uncertainties of the target location. Accurate and robust tracking is significant for improving operation accuracy. APPROACH: In this work, we propose a tracking framework Multi3, including a Multi-templates Siamese network, Multi-peaks detection and Multi-features refinement, for target tracking in ultrasound sequences. Specifically, we use two templates to provide the location and deformation of the target for robust tracking. Multi-peaks detection is applied to extend the set of potential target locations, and multi-features refinement is designed to select an appropriate location as the tracking result by quality assessment. MAIN RESULTS: The proposed Multi3 is evaluated on a public dataset, i.e. MICCAI 2015 Challenge on Liver UltraSound Tracking (CLUST), and our clinical dataset provided by the Chinese People's Liberation Army General Hospital. Experimental results show that Multi3 achieves accurate and robust tracking in ultrasound sequences (0.75±0.62 mm and 0.51±0.32 mm tracking errors in two datasets). SIGNIFICANCE: The proposed Multi3 is the most robust method on the CLUST 2D benchmark set, exhibiting potential in clinical practice.

11.
Zhongguo Zhong Yao Za Zhi ; 47(15): 4074-4083, 2022 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-36046897

RESUMO

The lignan glycosyltransferase UGT236(belonging to the UGT71 B family) from Isatis indigotica can catalyze the production of phloridzin from phloretin in vitro. UGT236 shares high identity with P2'GT from apple. In this study, the recombinant plasmid pET28 a-MBP-UGT236 was transferred into Escherichia coli Rosetta(DE3) cells and induced by isopropyl-ß-D-thiogalactoside(IPTG). The purified UGT236 protein was used for enzymatic characterization with phloretin as substrate. The results showed that UGT236 had the optimal reaction temperature of 40 ℃ and the optimal pH 8(Na_2HPO_4-NaH_2PO_4 system). The UGT236 activity was inhibited by Ni~(2+) and Al~(3+), enhanced by Fe~(2+), Co~(2+), and Mn~(2+), and did not affected by Mg~(2+), Ca~(2+), Li~+, Na~+, or K~+. The K_m, K_(cat), and K_(cat)/K_m of phloretin were 61.03 µmol·L~(-1), 0.01 s~(-1), and 157.11 mol~(-1)·s~(-1)·L, and those of UDPG were 183.6 µmol·L~(-1), 0.01 s~(-1), and 51.91 mol~(-1)·s~(-1)·L, respectively. The possible active sites were predicted by homologous modeling and molecular docking. By mutagenisis and catalytic activity detection, three key active sites, Glu391, His15, and Thr141, were identified, while Phe146 was related to product diversity. In summary, we found that the lignan glycosyltransferase UGT236 from I.indigotica could catalyze the reaction of phloretin into phloridzin. Several key amino acid residues were identified by structure prediction, molecular docking, and site-mutagenesis, which provided a basis for studying the specificity and diversity of phloretin glycoside products. This study can provide a reference for artificially producing glycosyltransferase elements with high efficiency and specific catalysis.


Assuntos
Isatis , Lignanas , Glucosiltransferases/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Lignanas/metabolismo , Simulação de Acoplamento Molecular , Floretina/metabolismo , Florizina/metabolismo
12.
Zhongguo Zhong Yao Za Zhi ; 47(15): 4214-4220, 2022 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-36046912

RESUMO

This study aims to establish an ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method for the determination of emodin-8-O-ß-D-glucoside(EG) and its metabolites in plasma, and to investigate the toxicokinetics(TK) behavior of them in rats. To be specific, the TK of EG and its metabolites from the first to the last administration in the repeated dose toxicity study was determined, and the kinetic parameters were calculated. The exposure of EG prototype and metabolites in rat plasma after oral administration of different doses of EG was evaluated. The result showed that the prototype of EG and its metabolites aloe-emodin-8-O-ß-D-glucoside, emodin, aloe-emodin, and hydroxyemodin could be detected in rats after oral administration of high-, medium-, and low-dose EG. The area under the curve(AUC) of the prototype and metabolites after the first and last administration was in positive correlation with the dose. The time to the maximum concentration(T_(max)) of EG and metabolites in the three administration groups was <6 h, and the longest in vivo residence time was 12 h. The T_(max) and in vivo residence time of EG were prolonged with the increase in the dose. The metabolites emodin, aloe-emodin, and hydroxyemodin all had two peaks. Both hydroxyemodin and aloe-emodin exhibited increased plasma exposure, slow metabolism, and accumulation in vivo. In addition, aloe-emodin-8-O-ß-D-glucoside and emodin disappeared with the increase in dose, suggesting the change of the metabolic pathway of EG in vivo in the case of high-dose administration. The mechanism of high-dose EG in vivo needs to be further explored. This study preliminarily elucidates the TK behavior of EG in rats, which is expected to support clinical drug use.


Assuntos
Emodina , Animais , Antraquinonas , Cromatografia Líquida de Alta Pressão/métodos , Emodina/toxicidade , Glucosídeos/toxicidade , Espectrometria de Massas , Ratos , Toxicocinética
13.
iScience ; 25(9): 104917, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36051182

RESUMO

Robust axon regeneration of motoneurons (MNs) occurs in rodent models upon peripheral nerve injury (PNI). However, genome-wide dynamic molecules and permissive microenvironment following insult in MNs remain largely unknown. Here, we firstly tackled by high-coverage and massive sequencing of laser-dissected individual ChAT+ cells to uncover molecules and pro-regenerative programs of MNs from injury to the regenerating phase after PNI. "Injured" populations at 1d∼7d were well distinguished and three response phases were well defined by elucidating with several clues (Gap43, etc). We found remarkable changes of genes expressed by injured motoneurons to activate and enhance intrinsic axon regrowth or crosstalk with other cellular or non-cellular counterpart in the activated regenerative microenvironment, specifically microglia/macrophage. We also identified an injury and regeneration-associated module and critical regulators including core transcription factors (Atf3, Arid5a, Klf6, Klf7, Jun, Stat3, and Myc). This study provides a vital resource and critical molecules for studying neural repair of axotomized motoneurons.

14.
Kaohsiung J Med Sci ; 2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36056704

RESUMO

Renal epithelioid angiomyolipoma (EAML) is a unique subtype of angiomyolipoma that contains a variety of cytoplasmic-rich, eosinophilic cytoplasm epithelioid cells in addition to mature adipocytes, hyaline thick-walled vessels, and smooth muscle-like spindle cells. In recent years, increasing evidence has shown that EAML is a potentially malignant tumor. Due to the lack of typical clinical manifestations and imaging features, it is difficult to diagnose before surgery, and the diagnosis mainly depends on postoperative histopathological examination. With the advancement of pathological diagnostic techniques, more EAML cases has been discovered, but clinicians still lack a comprehensive understanding of EAML. This review comprehensively describes some pathological and clinical features of EAML, with special attention to the pathogenesis and treatment of malignant EAML in order to assist with clinical diagnosis and treatment.

15.
J Endovasc Ther ; : 15266028221120770, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36052436

RESUMO

PURPOSE: Our goal was to report the transcatheter closure of a paravalvular leak after transcatheter aortic valve replacement (TAVR) using 3-dimensional (3D) printing. CASE REPORT: A 66-year-old man who had undergone transapical and TAVR 2 years ago due to aortic regurgitation, presented with palpitations and shortness of breath owing to exacerbation of paravalvular regurgitation. Echocardiography suggested that the stented aortic valve was fixed securely in place and the valve leaflets moved normally after TAVR, but there was severe paravalvular regurgitation (3 bundles, volume 11.0 mL). Due to the high surgical risk, we closed the transcatheter paravalvular leak using preprocedural guidance with 3D printing and intraprocedural guidance with digital subtraction angiography. Postoperative echocardiography showed that the paravalvular leak was significantly reduced. 3D construction showed that the occluders and the stent valve were well placed. CONCLUSION: Transcatheter closure of a paravalvular leak of the aortic valve may be feasible with appropriate pre- and intraoperative 3D printing guidance. CLINICAL IMPACT: 3D printing technology may help surgeons to make accurate preoperative strategy before occlusion procedures.

16.
Biomed Pharmacother ; 153: 113493, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36076508

RESUMO

Natural polypeptides, a kind of molecular polymer with obvious biological activity, are widely existing in nature. They participate in various physiological activities of living organisms and play an important role in promoting human health. They are also widely applied in medicine, food, and cosmetic industries. By searching literature from Pubmed, Google Scholar, Web of Science, Springer Link and Elsevier, this work presents an overview of the preparation methods, the relationship between structure and function, and the application of natural polypeptides. The preparation methods mainly include solvent extraction, enzymatic decomposition, microbiological fermentation, chemical synthesis, genetic engineering recombination, and using cell free system. Natural polypeptide's physiological function mainly includes antioxidative, antibacterial, antihypertensive. This review could provide scientific basis for the research and development of natural polypeptide.


Assuntos
Anti-Hipertensivos , Peptídeos , Humanos , Peptídeos/química , Polímeros
17.
Biosci Trends ; 2022 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-36089338

RESUMO

Hepatocellular carcinoma (HCC) remains a health challenge with increasing incidence worldwide. Radiofrequency ablation (RFA) is a potentially curative option for patients with early-stage HCC. However, the high rate of tumor recurrence limits long-term survival when the tumors are larger than 2 cm and undergoing insufficient RFA (iRFA). Notably, in situ tumor necrosis due to thermal ablation is assumed to be a source of antigens that induce antitumor immunity. Therefore, mounting studies and trials have attempted to provide a rational and effective therapeutic strategy combining RFA and immunotherapy to treat HCC. Nowadays, many controversies and challenges with this combined therapeutic strategy remain to be resolved, such as the indications for adjuvant immunotherapy along with RFA in early HCC, the sequence of the two treatments in advanced HCC, and the optimal timing of immunotherapy before or after RFA. In addition, individualized treatment strategies need to be perfected for patients with HCC.

18.
Polymers (Basel) ; 14(17)2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36080596

RESUMO

Based on the electronic universal testing machine with a temperature chamber, this paper investigated the temperature and filler effects on the hyper-elastic behavior of reinforced rubbers and revealed the regulation of the stress and strain of the natural rubber and filled rubber with temperature. The experimental results showed that the hyper-elastic behavior of the filled rubber was temperature-dependent in a wide range. Comparing the adaptability of different models to the stress-strain variation with temperature, the Yeoh model was proven to reasonably characterize the experimental data at different temperatures. Based on the Yeoh model, an explicit temperature-dependent constitutive model was developed to describe the stress-strain response of the filled rubber in a relatively large temperature range. The prediction data of this proposed constitutive model fit well with the test data of the mechanical experiments, indicating that the model is suitable to characterize the large deformation behavior of filled rubbers at different temperatures to a certain degree. The proposed model can be used to obtain the material parameters and has been successfully applied to finite element analysis (FEA), suggesting a high application value. Notably, the model has a simple form and can be conveniently applied in related performance tests of actual production or finite element analysis.

19.
Sensors (Basel) ; 22(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36081158

RESUMO

In this paper, we design a silica-cladded Germania-doped ring-core fiber (RCF) that supports orbital angular momentum (OAM) modes. By optimizing the fiber structure parameters, the RCF possesses a near-zero flat dispersion with a total variation of <±30 ps/nm/km over 1770 nm bandwidth from 1040 to 2810 nm for the OAM1,1 mode. A beyond-two-octave supercontinuum spectrum of the OAM1,1 mode is generated numerically by launching a 40 fs 120 kW pulse train centered at 1400 nm into a 12 cm long designed 50 mol% Ge-doped fiber, which covers 2130 nm bandwidth from 630 nm to 2760 nm at -40 dB of power level. This design can serve as an efficient way to extend the spectral coverage of beams carrying OAM modes for various applications.

20.
Front Cell Neurosci ; 16: 910699, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36090791

RESUMO

A previously published study showed that stress may interfere with associative aversive learning and facilitate mood-related disorders. However, whether emotional stress alone affects aversive learning is unknown. Using three chamber-vicarious social defeat stress (3C-VSDS) model mice, we investigated the effect of emotional stress on aversive learning. An important origin of dopamine (DA) neurons, the zona incerta (ZI), is expected to be a novel target for the modulation of aversive learning. However, less is known about the circuit mechanism of ZI DA neurons in aversive learning. Here, we subjected mice to a fear-conditioning system (FCS) and observed an increased calcium activity of ZI TH+ neurons in aversive expectation during the conditioning phase, especially during the late stage of the conditional stimulus (CS) when CS and unconditional stimulus (US) pairings were used. Optogenetic inhibition of ZI TH+ neurons at the late stage of CS disrupted conditioned fear learning in mice. We further identified a TH+ projection from the ZI to the basomedial amygdala (BMA) and found that optogenetic inhibition of the ZI-BMA circuit could also block aversive learning. Finally, we used 3C-VSDS mice as a model of emotional stress. We found that the 3C-VSDS model mice demonstrated reduced aversive expectation associated with ZI TH+ neurons in the late stage of CS and impaired aversive learning in FCS. Optogenetic activation of ZI-BMA TH+ projections in the late stage of CS significantly reversed the aversive FCS learning disability of 3C-VSDS model mice. These data suggest that a TH+ circuit from the ZI to the BMA is required for aversive expectation, both at baseline and in 3C-VSDS-induced aversive learning deficits and that this circuit is a potential target for the modulation of aversive learning. Low activity of ZI-BMA TH+ projections is one reason for 3C-VSDS-induced aversive learning deficits.

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