Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Int J Surg ; 110(5): 2593-2603, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38748500

RESUMO

PURPOSE: The authors aimed to establish an artificial intelligence (AI)-based method for preoperative diagnosis of breast lesions from contrast enhanced mammography (CEM) and to explore its biological mechanism. MATERIALS AND METHODS: This retrospective study includes 1430 eligible patients who underwent CEM examination from June 2017 to July 2022 and were divided into a construction set (n=1101), an internal test set (n=196), and a pooled external test set (n=133). The AI model adopted RefineNet as a backbone network, and an attention sub-network, named convolutional block attention module (CBAM), was built upon the backbone for adaptive feature refinement. An XGBoost classifier was used to integrate the refined deep learning features with clinical characteristics to differentiate benign and malignant breast lesions. The authors further retrained the AI model to distinguish in situ and invasive carcinoma among breast cancer candidates. RNA-sequencing data from 12 patients were used to explore the underlying biological basis of the AI prediction. RESULTS: The AI model achieved an area under the curve of 0.932 in diagnosing benign and malignant breast lesions in the pooled external test set, better than the best-performing deep learning model, radiomics model, and radiologists. Moreover, the AI model has also achieved satisfactory results (an area under the curve from 0.788 to 0.824) for the diagnosis of in situ and invasive carcinoma in the test sets. Further, the biological basis exploration revealed that the high-risk group was associated with the pathways such as extracellular matrix organization. CONCLUSIONS: The AI model based on CEM and clinical characteristics had good predictive performance in the diagnosis of breast lesions.


Assuntos
Inteligência Artificial , Neoplasias da Mama , Mamografia , Humanos , Feminino , Mamografia/métodos , Neoplasias da Mama/diagnóstico por imagem , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Meios de Contraste , Idoso , Aprendizado Profundo , Mama/diagnóstico por imagem , Mama/patologia
2.
Int J Biol Macromol ; 271(Pt 1): 132394, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38761905

RESUMO

The treatment of peripheral nerve injury is a clinical challenge that tremendously affected the patients' health and life. Anisotropic topographies and electric cues can simulate the regenerative microenvironment of nerve from physical and biological aspects, which show promising application in nerve regeneration. However, most studies just unilaterally emphasize the effect of sole topological- or electric- cue on nerve regeneration, while rarely considering the synergistic function of both cues simultaneously. In this study, a biomimetic-inspired piezoelectric topological ovalbumin/BaTiO3 scaffold that can provide non-invasive electrical stimulation in situ was constructed by combining piezoelectric BaTiO3 nanoparticles and surface microtopography. The results showed that the incorporation of piezoelectric nanoparticles could improve the mechanical properties of the scaffolds, and the piezoelectric output of the scaffolds after polarization was significantly increased. Biological evaluation revealed that the piezoelectric topological scaffolds could regulate the orientation growth of SCs, promote axon elongation of DRG, and upregulate the genes expression referring to myelination and axon growth, thus rapidly integrated chemical-mechanical signals and transmitted them for effectively promoting neuronal myelination, which was closely related to peripheral neurogenesis. The study suggests that the anisotropic surface topology combined with non-invasive electronic stimulation of the ovalbumin/BaTiO3 scaffolds possess a promising application prospect in the repair and regeneration of peripheral nerve injury.

3.
Colloids Surf B Biointerfaces ; 239: 113967, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38761494

RESUMO

The re-bridging of the deficient nerve is the main problem to be solved after the functional impairment of the peripheral nerve. In this study, a directionally aligned polycaprolactone/triiron tetraoxide (PCL/Fe3O4) fiber scaffolds were firstly prepared by electrospinning technique, and further then grafted with IKVAV peptide for regulating DRG growth and axon extension in peripheral nerve regeneration. The results showed that oriented aligned magnetic PCL/Fe3O4 composite scaffolds were successfully prepared by electrospinning technique and possessed good mechanical properties and magnetic responsiveness. The PCL/Fe3O4 scaffolds containing different Fe3O4 concentrations were free of cytotoxicity, indicating the good biocompatibility and low cytotoxicity of the scaffolds. The IKVAV-functionalized PCL/Fe3O4 scaffolds were able to guide and promote the directional extension of axons, the application of external magnetic field and the grafting of IKVAV peptides significantly further promoted the growth of DRGs and axons. The ELISA test results showed that the AP-10 F group scaffolds promoted the secretion of nerve growth factor (NGF) from DRG under a static magnetic field (SMF), thus promoting the growth and extension of axons. Importantly, the IKVAV-functionalized PCL/Fe3O4 scaffolds could significantly up-regulate the expression of Cntn2, PCNA, Sox10 and Isca1 genes related to adhesion, proliferation and magnetic receptor function under the stimulation of SMF. Therefore, IKVAV-functionalized PCL/Fe3O4 composite oriented scaffolds have potential applications in neural tissue engineering.


Assuntos
Poliésteres , Alicerces Teciduais , Animais , Poliésteres/química , Ratos , Alicerces Teciduais/química , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Gânglios Espinais/efeitos dos fármacos , Fator de Crescimento Neural/farmacologia , Fator de Crescimento Neural/química , Regeneração Nervosa/efeitos dos fármacos , Campos Magnéticos , Compostos Férricos/química , Compostos Férricos/farmacologia , Ratos Sprague-Dawley , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Células PC12
4.
Ying Yong Sheng Tai Xue Bao ; 35(3): 695-704, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38646757

RESUMO

To understand the effects of different stover mulching amounts in no-tillage on soil carbon and nitrogen contents and enzyme activities, finding a stover mulching amount which can meet the requirement of soil carbon and nitrogen accumulation while maximizing economic benefits, we conducted a long-term conservation tillage field experiment since 2007 in Mollisols area of Northeast China. We analyzed soil carbon and nitrogen contents, enzyme activities and economic benefits under conventional tillage (Control, CT), no-tillage without stover mulching (NT0), no-tillage with 33% stover mulching (NT33), no-tillage with 67% stover mulching (NT67), and no-tillage with 100% stover mulching (NT100) before planting in May 2020. The results showed that compared with CT, NT0 did not affect soil organic carbon (SOC) and total nitrogen (TN) contents, but increased soil organic carbon recalcitrance and decreased the availability of dissolved organic nitrogen (DON) and ammonium nitrogen. Compared with NT0, no-tillage with stover mulching significantly increased SOC contents in 0-10 cm layer and increased with the amounts of stover. In addition, NT67 and NT100 significantly increased SOC stocks, facilitating the accumulation of soil organic matter. The effects of different stover mulching amounts on soil nitrogen content in 0-10 cm layer were different. Specifically, NT33 increased DON content and DON/TN, NT67 increased DON content, while NT100 increased TN content. Compared with CT, NT0 decreased peroxidase (POD) activity in 0-10 cm layer. Compared with NT0, NT33 increased ß-glucosidase (ßG), cellobiase (CB), 1,4-ß-N-acetylglucosaminidase (NAG), polyphenol oxidase (PPO) and POD activities, while NT67 only increased CB, NAG and POD activities in 0-10 cm soil layer, both alleviated microbial nutrient limitation. NT100 increased PPO activity in 10-20 cm layer. NT33 increased carbon conversion efficiency of stover compared with NT100, and had the highest economic benefit. In all, no-tillage with 33% stover mulching was the optimal strategy, which could promote nutrient circulation, boost stover utilization efficiency, improve the quality of Mollisols, and maximize guaranteed income.


Assuntos
Agricultura , Carbono , Ciclo do Nitrogênio , Nitrogênio , Solo , Nitrogênio/metabolismo , Nitrogênio/análise , Solo/química , Carbono/metabolismo , Carbono/análise , Agricultura/métodos , China
5.
Biophys J ; 123(9): 1085-1097, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38640928

RESUMO

As the main gatekeeper of the nucleocytoplasmic transport in eukaryotic cells, the nuclear pore complex (NPC) faces the daunting task of facilitating the bidirectional transport of a high volume of macromolecular cargoes while ensuring the selectivity, speed, and efficiency of this process. The competition between opposing nuclear import and export fluxes passing through the same channel is expected to pose a major challenge to transport efficiency. It has been suggested that phase separation-like radial segregation of import and export fluxes within the assembly of intrinsically disordered proteins that line the NPC pore could be a mechanism for ensuring efficient bidirectional transport. We examine the impact of radial segregation on the efficiency of bidirectional transport through the NPC using a coarse-grained computational model of the NPC. We find little evidence that radial segregation improves transport efficiency. By contrast, surprisingly, we find that NTR crowding may enhance rather than impair the efficiency of bidirectional transport although it decreases the available space in the pore. We identify mechanisms of this novel crowding-induced transport cooperativity through the self-regulation of cargo density and flux in the pore. These findings explain how the functional architecture of the NPC resolves the problem of efficient bidirectional transport, and provide inspiration for the alleviation of clogging in artificial selective nanopores.


Assuntos
Poro Nuclear , Poro Nuclear/metabolismo , Poro Nuclear/química , Cinética , Transporte Ativo do Núcleo Celular , Modelos Biológicos
6.
Sci Total Environ ; 924: 171596, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38461990

RESUMO

Climate change affects microbial community physiological strategies and thus regulates global soil organic carbon (SOC) decomposition. However, SOC decomposition by microorganisms, depending on home-field advantage (HFA, indicating a faster decomposition rate in 'Home' than 'Away' conditions) or environmental advantage (EA, indicating a faster decomposition rate in warmer-wetter environments than in colder-drier environments) remains unknown. Here, a soil transplantation experiment was conducted between warmer-wetter and colder-drier evergreen broadleaved forests in subtropical China. Specifically, soil samples were collected along a 60 cm soil profile, including 0-15, 15-30, 30-45, and 45-60 cm layers after one year of transplantation. SOC fractions, soil chemical properties, and microbial communities were evaluated to assess where there was an HFA of EA in SOC decomposition, along with an exploration of internal linkages. Significant HFAs were observed, particularly in the deep soils (30-60 cm) (P < 0.05), despite the lack of a significant EA along a soil profile, which was attributed to environmental changes affecting soil fungal communities and constraining SOC decomposition in 'Away' conditions. The soils transplanted from warmer-wetter to colder-drier environments changed the proportions of Mortiereltomycota or Basidiomycota fungal taxa in deep soils. Furthermore, the shift from colder-drier to warmer-wetter environments decreased fungal α-diversity and the proportion of fungal necromass carbon, ultimately inhibiting SOC decomposition in 'Away' conditions. However, neither HFAs nor EAs were significantly present in the topsoil (0-30 cm), possibly due to the broader adaptability of bacterial communities in these layers. These results suggest that the HFA of SOC decomposition in deep soils may mostly depend on the plasticity of fungal communities. Moreover, these results highlight the key roles of microbial communities in the SOC decomposition of subtropical forests, especially in deep soils that are easily ignored.


Assuntos
Carbono , Solo , Solo/química , Carbono/química , Florestas , Mudança Climática , Bactérias , Microbiologia do Solo
7.
Bioact Mater ; 35: 401-415, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38384987

RESUMO

Peripheral nerve injury (PNI) seriously affects the health and life of patients, and is an urgent clinical problem that needs to be resolved. Nerve implants prepared from various biomaterials have played a positive role in PNI, but the effect should be further improved and thus new biomaterials is urgently needed. Ovalbumin (OVA) contains a variety of bioactive components, low immunogenicity, tolerance, antimicrobial activity, non-toxicity and biodegradability, and has the ability to promote wound healing, cell growth and antimicrobial properties. However, there are few studies on the application of OVA in neural tissue engineering. In this study, OVA implants with different spatial structures (membrane, fiber, and lyophilized scaffolds) were constructed by casting, electrospinning, and freeze-drying methods, respectively. The results showed that the OVA implants had excellent physicochemical properties and were biocompatible without significant toxicity, and can promote vascularization, show good histocompatibility, without excessive inflammatory response and immunogenicity. The in vitro results showed that OVA implants could promote the proliferation and migration of Schwann cells, while the in vivo results confirmed that OVA implants (the E5/70% and 20 kV 20 µL/min groups) could effectively regulate the growth of blood vessels, reduce the inflammatory response and promote the repair of subcutaneous nerve injury. Further on, the high-throughput sequencing results showed that the OVA implants up-regulated differential expression of genes related to biological processes such as tumor necrosis factor-α (TNF-α), phosphatidylinositide 3-kinases/protein kinase B (PI3K-Akt) signaling pathway, axon guidance, cellular adhesion junctions, and nerve regeneration in Schwann cells. The present study is expected to provide new design concepts and theoretical accumulation for the development of a new generation of nerve regeneration implantable biomaterials.

8.
Regen Biomater ; 11: rbae003, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38414796

RESUMO

Bioprosthetic heart valve (BHV) replacement has been the predominant treatment for severe heart valve diseases over decades. Most clinically available BHVs are crosslinked by glutaraldehyde (GLUT), while the high toxicity of residual GLUT could initiate calcification, severe thrombosis, and delayed endothelialization. Here, we construed a mechanically integrating robust hydrogel-tissue hybrid to improve the performance of BHVs. In particular, recombinant humanized collagen type III (rhCOLIII), which was precisely customized with anti-coagulant and pro-endothelialization bioactivity, was first incorporated into the polyvinyl alcohol (PVA)-based hydrogel via hydrogen bond interactions. Then, tannic acid was introduced to enhance the mechanical performance of PVA-based hydrogel and interfacial bonding between the hydrogel layer and bio-derived tissue due to the strong affinity for a wide range of substrates. In vitro and in vivo experimental results confirmed that the GLUT-crosslinked BHVs modified by the robust PVA-based hydrogel embedded rhCOLIII and TA possessed long-term anti-coagulant, accelerated endothelialization, mild inflammatory response and anti-calcification properties. Therefore, our mechanically integrating robust hydrogel-tissue hybrid strategy showed the potential to enhance the service function and prolong the service life of the BHVs after implantation.

9.
Nat Commun ; 15(1): 735, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38272886

RESUMO

Drug-eluting stent implantation suppresses the excessive proliferation of smooth muscle cells to reduce in-stent restenosis. However, the efficacy of drug-eluting stents remains limited due to delayed reendothelialization, impaired intimal remodeling, and potentially increased late restenosis. Here, we show that a drug-free coating formulation functionalized with tailored recombinant humanized type III collagen exerts one-produces-multi effects in response to injured tissue following stent implantation. We demonstrate that the one-produces-multi coating possesses anticoagulation, anti-inflammatory, and intimal hyperplasia suppression properties. We perform transcriptome analysis to indicate that the drug-free coating favors the endothelialization process and induces the conversion of smooth muscle cells to a contractile phenotype. We find that compared to drug-eluting stents, our drug-free stent reduces in-stent restenosis in rabbit and porcine models and improves vascular neointimal healing in a rabbit model. Collectively, the one-produces-multi drug-free system represents a promising strategy for the next-generation of stents.


Assuntos
Reestenose Coronária , Stents Farmacológicos , Suínos , Animais , Coelhos , Reestenose Coronária/prevenção & controle , Stents , Colágeno , Cicatrização
10.
J Magn Reson Imaging ; 59(5): 1710-1722, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37497811

RESUMO

BACKGROUND: Accurate diagnosis of breast lesions and discrimination of axillary lymph node (ALN) metastases largely depend on radiologist experience. PURPOSE: To develop a deep learning-based whole-process system (DLWPS) for segmentation and diagnosis of breast lesions and discrimination of ALN metastasis. STUDY TYPE: Retrospective. POPULATION: 1760 breast patients, who were divided into training and validation sets (1110 patients), internal (476 patients), and external (174 patients) test sets. FIELD STRENGTH/SEQUENCE: 3.0T/dynamic contrast-enhanced (DCE)-MRI sequence. ASSESSMENT: DLWPS was developed using segmentation and classification models. The DLWPS-based segmentation model was developed by the U-Net framework, which combined the attention module and the edge feature extraction module. The average score of the output scores of three networks was used as the result of the DLWPS-based classification model. Moreover, the radiologists' diagnosis without and with the DLWPS-assistance was explored. To reveal the underlying biological basis of DLWPS, genetic analysis was performed based on RNA-sequencing data. STATISTICAL TESTS: Dice similarity coefficient (DI), area under receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, and kappa value. RESULTS: The segmentation model reached a DI of 0.828 and 0.813 in the internal and external test sets, respectively. Within the breast lesions diagnosis, the DLWPS achieved AUCs of 0.973 in internal test set and 0.936 in external test set. For ALN metastasis discrimination, the DLWPS achieved AUCs of 0.927 in internal test set and 0.917 in external test set. The agreement of radiologists improved with the DLWPS-assistance from 0.547 to 0.794, and from 0.848 to 0.892 in breast lesions diagnosis and ALN metastasis discrimination, respectively. Additionally, 10 breast cancers with ALN metastasis were associated with pathways of aerobic electron transport chain and cytoplasmic translation. DATA CONCLUSION: The performance of DLWPS indicates that it can promote radiologists in the judgment of breast lesions and ALN metastasis and nonmetastasis. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 3.


Assuntos
Neoplasias da Mama , Aprendizado Profundo , Humanos , Feminino , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/patologia , Estudos Retrospectivos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Imageamento por Ressonância Magnética
11.
Eur Urol ; 85(3): 283-292, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37802683

RESUMO

BACKGROUND: Optimal patient selection for neoadjuvant chemotherapy prior to surgical extirpation is limited by the inaccuracy of contemporary clinical staging methods in high-risk upper tract urothelial carcinoma (UTUC). OBJECTIVE: To investigate whether the detection of plasma circulating tumor DNA (ctDNA) can predict muscle-invasive (MI) and non-organ-confined (NOC) UTUC. DESIGN, SETTING, AND PARTICIPANTS: Plasma cell-free DNA was prospectively collected from chemotherapy-naïve, high-risk UTUC patients undergoing surgical extirpation and sequenced using a 152-gene panel and low-pass whole-genome sequencing. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: To test for concordance, whole-exome sequencing was performed on matching tumor samples. The performance of ctDNA for predicting MI/NOC UTUC was summarized using the area under a receiver-operating curve, and a variant count threshold for predicting MI/NOC disease was determined by maximizing Youden's J statistic. Kaplan-Meier methods estimated survival, and Mantel-Cox log-rank testing assessed the association between preoperative ctDNA positivity and clinical outcomes. RESULTS AND LIMITATIONS: Of 30 patients enrolled prospectively, 14 were found to have MI/NOC UTUC. At least one ctDNA variant was detected from 21/30 (70%) patients, with 52% concordance with matching tumor samples. Detection of at least two panel-based molecular alterations yielded 71% sensitivity at 94% specificity to predict MI/NOC UTUC. Imposing this threshold in combination with a plasma copy number burden score of >6.5 increased sensitivity to 79% at 94% specificity. Furthermore, the presence of ctDNA was strongly prognostic for progression-free survival (PFS; 1-yr PFS 69% vs 100%, p < 0.001) and cancer-specific survival (CSS; 1-yr CSS 56% vs 100%, p = 0.016). CONCLUSIONS: The detection of plasma ctDNA prior to extirpative surgery was highly predictive of MI/NOC UTUC and strongly prognostic of PFS and CSS. Preoperative ctDNA demonstrates promise as a biomarker for selecting patients to undergo neoadjuvant chemotherapy prior to nephroureterectomy. PATIENT SUMMARY: Here, we show that DNA from upper tract urothelial tumors can be detected in the blood prior to surgical removal of the kidney or ureter. This circulating tumor DNA can be used to predict that upper tract urothelial carcinoma is invasive into the muscular lining of the urinary tract and may help identify those patients who could benefit from chemotherapy prior to surgery.


Assuntos
Carcinoma de Células de Transição , DNA Tumoral Circulante , Neoplasias Ureterais , Neoplasias da Bexiga Urinária , Humanos , Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/cirurgia , Carcinoma de Células de Transição/diagnóstico , DNA Tumoral Circulante/genética , Estudos Retrospectivos , Prognóstico , Músculos/patologia , Neoplasias Ureterais/genética , Neoplasias Ureterais/cirurgia
13.
Adv Clin Exp Med ; 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38085007

RESUMO

BACKGROUND: The number and activity of osteoblasts and osteoclasts play an important role in skeletal biology, especially in bone reconstruction. Scientific and rational regulation of osteoclast formation and activity has become a critical strategy aimed at inhibiting the loss of bone mass in the body and alleviating the occurrence of bone diseases. Currently, there are only a few reports related to hesperetin-regulated osteoclast differentiation. OBJECTIVES: To investigate the influence of hesperetin on osteoclast-like cell differentiation and formation, and determine whether the MAPK signaling pathway is involved in the differentiation process. MATERIAL AND METHODS: The RAW264.7 cells were induced and cultured in vitro to promote their differentiation into osteoclast-like cells. Tetrazolium bromide was utilized to determine the effects of different concentrations (100, 200, 400, and 600 µM) of hesperetin on the proliferation of osteoclast-like cell precursors. Osteoclast-like cell differentiation was conducted using tartrate-resistant acid phosphatase (TRAP) staining assay. The status of nuclei and actin filaments of differentiated osteoclast-like cells was observed with the use of 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and actin-tracker green staining experiments. Changes in key proteins of the MAPK signaling pathway were detected using western blot. RESULTS: The results of TRAP staining experiments showed that the number of osteoclast-like cells decreased with the increase in hesperetin concentration. The DAPI and actin-tracker green staining demonstrated that the nuclei of differentiated osteoclast-like cells reduced in size with the increase in hesperetin concentration, and the osteoclast-like cells became smaller. Western blot for key MAPK signaling pathway proteins revealed that phospho-ERK and phospho-p38 protein levels were not significantly inhibited, but phospho-JNK protein levels were reduced. CONCLUSIONS: Hesperetin inhibits the differentiation of osteoclast-like cells. Further studies revealed that hesperetin also affects the activation level of phospho-JNK, a key signaling protein of the MAPK signaling pathway, in the induced differentiation of osteoclast-like cells.

14.
Front Mol Biosci ; 10: 1260914, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028555

RESUMO

The stepping dynamics of cytoskeletal motor proteins determines the dynamics of cargo transport. In its native cellular environment, a molecular motor is subject to forces from several sources including thermal forces and forces ensuing from the interaction with other motors bound to the same cargo. Understanding how the individual motors respond to these forces can allow us to predict how they move their cargo when part of a team. Here, using simulation, we show that details of how the kinesin motor responds to small assisting forces-which, at the moment, are not experimentally constrained-can lead to significant changes in cargo dynamics. Using different models of the force-dependent detachment probability of the kinesin motor leads to different predictions on the run-length of the cargo they carry. These differences emerge from the thermal forces acting on the cargo and transmitted to the motor through the motor tail that tethers the motor head to the microtubule. We show that these differences appear for cargo carried by individual motors or motor teams, and use our findings to propose the use of thermal forces as a probe of kinesin's response to force in this otherwise inaccessible force regime.

15.
Biomater Sci ; 11(22): 7296-7310, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37812084

RESUMO

The purpose of nerve regeneration via tissue engineering strategies is to create a microenvironment that mimics natural nerve growth for achieving functional recovery. Biomaterial scaffolds offer a promising option for the clinical treatment of large nerve gaps due to the rapid advancement of materials science and regenerative medicine. The design of biomimetic scaffolds should take into account the inherent properties of the nerve and its growth environment, such as stiffness, topography, adhesion, conductivity, and chemical functionality. Various advanced techniques have been employed to develop suitable scaffolds for nerve repair. Since neuronal cells have electrical activity, the transmission of bioelectrical signals is crucial for the functional recovery of nerves. Therefore, an ideal peripheral nerve scaffold should have electrical activity properties similar to those of natural nerves, in addition to a delicate structure. Piezoelectric materials can convert stress changes into electrical signals that can activate different intracellular signaling pathways critical for cell activity and function, which makes them potentially useful for nerve tissue regeneration. However, a comprehensive review of piezoelectric materials for neuroregeneration is still lacking. Thus, this review systematically summarizes the development of piezoelectric materials and their application in the field of nerve regeneration. First, the electrical signals and natural piezoelectricity phenomenon in various organisms are briefly introduced. Second, the most commonly used piezoelectric materials in neural tissue engineering, including biocompatible piezoelectric polymers, inorganic piezoelectric materials, and natural piezoelectric materials, are classified and discussed. Finally, the challenges and future research directions of piezoelectric materials for application in nerve regeneration are proposed.


Assuntos
Materiais Biocompatíveis , Alicerces Teciduais , Alicerces Teciduais/química , Materiais Biocompatíveis/química , Engenharia Tecidual/métodos , Medicina Regenerativa , Regeneração Nervosa
16.
Int J Biol Macromol ; 253(Pt 4): 127015, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37758111

RESUMO

Peripheral nerve injuries (PNI) currently have limited therapeutic efficacy, and functional scaffolds have been shown to be effective for treating PNI. Ovalbumin (OVA) is widely used as a natural biomaterial for repairing damaged tissues due to its excellent biocompatibility and the presence of various bioactive components. However, there are few reports on the repair of PNI by ovalbumin. In this study, a novel bionic functionalized topological scaffold based on ovalbumin and grafted with tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide was constructed by micro-molding method and surface-biomodification technology. The scaffolds were subjected to a series of evaluations in terms of morphology, mechanics, hydrophilicity, and biocompatibility, and the related molecular mechanisms were further penetrated. The results showed that the scaffolds prepared in this study had aligned ridge/groove structure, good mechanical properties and biocompatibility, and could be used as carriers to slowly release YIGSR, which effectively promoted the proliferation, migration and elongation of Schwann Cells (SCs), and significantly up-regulated the gene expression related to proliferation, apoptosis, migration and axon regeneration. Therefore, the bionic functional topological scaffold has significant application potential for promoting peripheral nerve regeneration and provides a new therapeutic option for repairing PNI.


Assuntos
Axônios , Traumatismos dos Nervos Periféricos , Humanos , Ovalbumina/metabolismo , Regeneração Nervosa/fisiologia , Células de Schwann , Peptídeos/química , Traumatismos dos Nervos Periféricos/terapia , Alicerces Teciduais/química
17.
FEMS Microbiol Ecol ; 99(11)2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37771081

RESUMO

Litter decomposition is a fundamental ecosystem process controlling the biogeochemical cycling of energy and nutrients. Using a 360-day lab incubation experiment to control for environmental factors, we tested how litter quality (low C/N deciduous vs. high C/N coniferous litter) governed the assembly and taxonomic composition of bacterial communities and rates of litter decomposition. Overall, litter mass loss was significantly faster in soils amended with deciduous (DL) rather than coniferous (CL) litter. Communities degrading DL were also more taxonomically diverse and exhibited stochastic assembly throughout the experiment. By contrast, alpha-diversity rapidly declined in communities exposed to CL. Strong environmental selection and competitive biological interactions induced by molecularly complex, nutrient poor CL were reflected in a transition from stochastic to deterministic assembly after 180 days. Constraining how the diversity and assembly of microbial populations modulates core ecosystem processes, such as litter decomposition, will become increasingly important under novel climate conditions, and as policymakers and land managers emphasize soil carbon sequestration as a key natural climate solution.


Assuntos
Ecossistema , Plantas , Clima , Solo/química , Bactérias/genética , Folhas de Planta/química , Microbiologia do Solo
18.
Chin J Cancer Res ; 35(4): 408-423, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37691895

RESUMO

Objective: Accurate detection and classification of breast lesions in early stage is crucial to timely formulate effective treatments for patients. We aim to develop a fully automatic system to detect and classify breast lesions using multiple contrast-enhanced mammography (CEM) images. Methods: In this study, a total of 1,903 females who underwent CEM examination from three hospitals were enrolled as the training set, internal testing set, pooled external testing set and prospective testing set. Here we developed a CEM-based multiprocess detection and classification system (MDCS) to perform the task of detection and classification of breast lesions. In this system, we introduced an innovative auxiliary feature fusion (AFF) algorithm that could intelligently incorporates multiple types of information from CEM images. The average free-response receiver operating characteristic score (AFROC-Score) was presented to validate system's detection performance, and the performance of classification was evaluated by area under the receiver operating characteristic curve (AUC). Furthermore, we assessed the diagnostic value of MDCS through visual analysis of disputed cases, comparing its performance and efficiency with that of radiologists and exploring whether it could augment radiologists' performance. Results: On the pooled external and prospective testing sets, MDCS always maintained a high standalone performance, with AFROC-Scores of 0.953 and 0.963 for detection task, and AUCs for classification were 0.909 [95% confidence interval (95% CI): 0.822-0.996] and 0.912 (95% CI: 0.840-0.985), respectively. It also achieved higher sensitivity than all senior radiologists and higher specificity than all junior radiologists on pooled external and prospective testing sets. Moreover, MDCS performed superior diagnostic efficiency with an average reading time of 5 seconds, compared to the radiologists' average reading time of 3.2 min. The average performance of all radiologists was also improved to varying degrees with MDCS assistance. Conclusions: MDCS demonstrated excellent performance in the detection and classification of breast lesions, and greatly enhanced the overall performance of radiologists.

19.
Medicine (Baltimore) ; 102(39): e34366, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773819

RESUMO

INTRODUCTION: In recent years, efferocytosis in cardiovascular diseases has become an intense area of research. However, only a few bibliometric analyses have been conducted in this area. In this review, we used CiteSpace 5.7. R2 and VOSviewer 1.6.17 software to perform text mining and knowledge map analysis. This study summarizes the latest progress, development paths, frontier research hotspots, and future research trends in this field. MATERIALS AND METHODS: Studies on efferocytosis in cardiovascular diseases were downloaded from the Web of Science Core Collection. RESULTS: In total, 327 studies published by 506 institutions across 42 countries and regions were identified. The number of studies on efferocytosis in cardiovascular diseases has increased over time. Arteriosclerosis Thrombosis and Vascular Biology published the highest number of articles and was the top co-cited journal. Tabas Ira. was the most prolific researcher and co-cited the most. The most productive countries were the United States and China. Columbia University, Harvard Medical School, and Brigham Women's Hospital were the 3 most productive institutions in the field of research. Keyword Co-occurrence, Clusters, and Burst analyses showed that inflammation, atherosclerosis, macrophages, and phagocytosis appeared with the highest frequency in these studies. CONCLUSION: Multinational cooperation and multidisciplinary intersections are characteristic trends of development in the field, and the immune microenvironment, glycolysis, and lipid metabolism will be the focus of future research.


Assuntos
Doenças Cardiovasculares , Feminino , Humanos , Doenças Cardiovasculares/epidemiologia , Fagocitose , Inflamação , Macrófagos , Bibliometria
20.
Proc Natl Acad Sci U S A ; 120(33): e2305704120, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37549277

RESUMO

Biocompatible and morphable hydrogels capable of multimode reprogrammable, and adaptive shape changes are potentially useful for diverse biomedical applications. However, existing morphable systems often rely on complicated structural designs involving cumbersome and energy-intensive fabrication processes. Here, we report a simple electric-field-activated protein network migration strategy to reversibly program silk-protein hydrogels with controllable and reprogrammable complex shape transformations. The application of a low electric field enables the convergence of net negatively charged protein cross-linking networks toward the anode (isoelectric point plane) due to the pH gradient generated in the process, facilitating the formation of a gradient network structure and systems suitable for three-dimensional shape change. These tunable protein networks can be reprogrammed or permanently fixed by control of the polymorphic transitions. We show that these morphing hydrogels are capable of conformally interfacing with biological tissues by programming the shape changes and a bimorph structure consisting of aligned carbon nanotube multilayers and the silk hydrogels was assembled to illustrate utility as an implantable bioelectronic device for localized low-voltage electrical stimulation of the sciatic nerve in a rabbit.


Assuntos
Hidrogéis , Seda , Animais , Coelhos , Seda/química , Hidrogéis/química , Ponto Isoelétrico , Materiais Biocompatíveis/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA