Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 530
Filtrer
1.
Nano Lett ; 24(26): 7953-7961, 2024 Jul 03.
Article de Anglais | MEDLINE | ID: mdl-38888317

RÉSUMÉ

The physical properties of nanoscale cell-extracellular matrix (ECM) ligands profoundly impact biological processes, such as adhesion, motility, and differentiation. While the mechanoresponse of cells to static ligands is well-studied, the effect of dynamic ligand presentation with "adaptive" properties on cell mechanotransduction remains less understood. Utilizing a controllable diffusible ligand interface, we demonstrated that cells on surfaces with rapid ligand mobility could recruit ligands through activating integrin α5ß1, leading to faster focal adhesion growth and spreading at the early adhesion stage. By leveraging UV-light-sensitive anchor molecules to trigger a "dynamic to static" transformation of ligands, we sequentially activated α5ß1 and αvß3 integrins, significantly promoting osteogenic differentiation of mesenchymal stem cells. This study illustrates how manipulating molecular dynamics can directly influence stem cell fate, suggesting the potential of "sequentially" controlled mobile surfaces as adaptable platforms for engineering smart biomaterial coatings.


Sujet(s)
Adhérence cellulaire , Différenciation cellulaire , Mécanotransduction cellulaire , Cellules souches mésenchymateuses , Propriétés de surface , Cellules souches mésenchymateuses/cytologie , Humains , Intégrine alpha5bêta1/métabolisme , Ostéogenèse , Matrice extracellulaire/composition chimique , Matrice extracellulaire/métabolisme , Intégrine alphaVbêta3/métabolisme , Ligands , Contacts focaux
2.
Nat Genet ; 2024 Jun 05.
Article de Anglais | MEDLINE | ID: mdl-38839885

RÉSUMÉ

Aneuploidy is frequently detected in early human embryos as a major cause of early pregnancy failure. However, how aneuploidy affects cellular function remains elusive. Here, we profiled the transcriptomes of 14,908 single cells from 203 human euploid and aneuploid blastocysts involving autosomal and sex chromosomes. Nearly all of the blastocysts contained four lineages. In aneuploid chromosomes, 19.5% ± 1.2% of the expressed genes showed a dosage effect, and 90 dosage-sensitive domains were identified. Aneuploidy leads to prevalent genome-wide transcriptome alterations. Common effects, including apoptosis, were identified, especially in monosomies, partially explaining the lower cell numbers in autosomal monosomies. We further identified lineage-specific effects causing unstable epiblast development in aneuploidies, which was accompanied by the downregulation of TGF-ß and FGF signaling, which resulted in insufficient trophectoderm maturation. Our work provides crucial insights into the molecular basis of human aneuploid blastocysts and may shed light on the cellular interaction during blastocyst development.

3.
Nature ; 630(8018): 943-949, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38898271

RÉSUMÉ

Spatial transcriptomics measures in situ gene expression at millions of locations within a tissue1, hitherto with some trade-off between transcriptome depth, spatial resolution and sample size2. Although integration of image-based segmentation has enabled impactful work in this context, it is limited by imaging quality and tissue heterogeneity. By contrast, recent array-based technologies offer the ability to measure the entire transcriptome at subcellular resolution across large samples3-6. Presently, there exist no approaches for cell type identification that directly leverage this information to annotate individual cells. Here we propose a multiscale approach to automatically classify cell types at this subcellular level, using both transcriptomic information and spatial context. We showcase this on both targeted and whole-transcriptome spatial platforms, improving cell classification and morphology for human kidney tissue and pinpointing individual sparsely distributed renal mouse immune cells without reliance on image data. By integrating these predictions into a topological pipeline based on multiparameter persistent homology7-9, we identify cell spatial relationships characteristic of a mouse model of lupus nephritis, which we validate experimentally by immunofluorescence. The proposed framework readily generalizes to new platforms, providing a comprehensive pipeline bridging different levels of biological organization from genes through to tissues.


Sujet(s)
Cellules , Analyse de profil d'expression de gènes , Espace intracellulaire , Rein , Transcriptome , Animaux , Femelle , Humains , Souris , Cellules/classification , Cellules/métabolisme , Modèles animaux de maladie humaine , Technique d'immunofluorescence , Analyse de profil d'expression de gènes/méthodes , Rein/cytologie , Rein/immunologie , Rein/métabolisme , Rein/anatomopathologie , Glomérulonéphrite lupique/génétique , Glomérulonéphrite lupique/immunologie , Glomérulonéphrite lupique/métabolisme , Glomérulonéphrite lupique/anatomopathologie , Reproductibilité des résultats , Espace intracellulaire/génétique , Espace intracellulaire/métabolisme
4.
J Environ Manage ; 361: 121268, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38820787

RÉSUMÉ

Carbon dioxide (CO2) production and emissions from inland waters play considerable roles in global atmospheric CO2 sources, while there are still uncertainties regarding notable nutrient inputs and anthropogenic activities. Urban inland waters, with frequently anthropogenic modifications and severely nitrogen loadings, were hotspots for CO2 emissions. Here, we investigated the spatiotemporal patterns of partial pressure of CO2 (pCO2) and CO2 fluxes (FCO2) in typical urban inland waters in Tianjin, China. Our observation indicated that pCO2 values were oversaturated in highly polluted waters, particularly in sewage rivers and urban rivers, exhibiting approximately 9 times higher than the atmosphere equilibrium concentration during sampling campaigns. Obviously, the spatiotemporal distributions of pCO2 and FCO2 emphasized that the water environmental conditions and anthropogenic activities jointly adjusted primary productivity and biological respiration of inland waters. Meanwhile, statistically positive correlations between pCO2/FCO2 and NH4+-N/NO3--N (p < 0.05) suggested that nitrogen biogeochemical processes, especially the nitrification, played a dominant role in CO2 emissions attributing to the water acidification that stimulated CO2 production and emissions. Except for slight CO2 sinks in waters with low organic contents, the total CO2 emissions from the urban surface waters of Tianjin were remarkable (286.8 Gg yr-1). The results emphasized that the reductions of nitrogen loadings, sewage draining waters, and agricultural pollution could alleviate CO2 emissions from urban inland waters.


Sujet(s)
Dioxyde de carbone , Azote , Dioxyde de carbone/analyse , Azote/analyse , Surveillance de l'environnement , Chine , Rivières/composition chimique
5.
World J Psychiatry ; 14(3): 456-466, 2024 Mar 19.
Article de Anglais | MEDLINE | ID: mdl-38617984

RÉSUMÉ

BACKGROUND: Adolescent major depressive disorder (MDD) is a significant mental health concern that often leads to recurrent depression in adulthood. Resting-state functional magnetic resonance imaging (rs-fMRI) offers unique insights into the neural mechanisms underlying this condition. However, despite previous research, the specific vulnerable brain regions affected in adolescent MDD patients have not been fully elucidated. AIM: To identify consistent vulnerable brain regions in adolescent MDD patients using rs-fMRI and activation likelihood estimation (ALE) meta-analysis. METHODS: We performed a comprehensive literature search through July 12, 2023, for studies investigating brain functional changes in adolescent MDD patients. We utilized regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) analyses. We compared the regions of aberrant spontaneous neural activity in adolescents with MDD vs healthy controls (HCs) using ALE. RESULTS: Ten studies (369 adolescent MDD patients and 313 HCs) were included. Combining the ReHo and ALFF/fALFF data, the results revealed that the activity in the right cuneus and left precuneus was lower in the adolescent MDD patients than in the HCs (voxel size: 648 mm3, P < 0.05), and no brain region exhibited increased activity. Based on the ALFF data, we found decreased activity in the right cuneus and left precuneus in adolescent MDD patients (voxel size: 736 mm3, P < 0.05), with no regions exhibiting increased activity. CONCLUSION: Through ALE meta-analysis, we consistently identified the right cuneus and left precuneus as vulnerable brain regions in adolescent MDD patients, increasing our understanding of the neuropathology of affected adolescents.

6.
Materials (Basel) ; 17(7)2024 Mar 29.
Article de Anglais | MEDLINE | ID: mdl-38612098

RÉSUMÉ

The flow behaviour of AA2060 Al alloy under warm/hot deformation conditions is complicated because of its dependency on strain rates (ε˙), strain (ε), and deformation modes. Thus, it is crucial to reveal and predict the flow behaviours of this alloy at a wide range of temperatures (T) and ε˙ using different constitutive models. Firstly, the isothermal tensile tests were carried out via a Gleeble-3800 thermomechanical simulator at a T range of 100, 200, 300, 400, and 500 °C and ε˙ range of 0.01, 0.1, 1, and 10 s-1 to reveal the warm/hot flow behaviours of AA2060 alloy sheet. Consequently, three phenomenological-based constitutive models (L-MJC, S1-MJC, S2-MJC) and a modified Zerilli-Armstrong (MZA) model representing physically based constitutive models were developed to precisely predict the flow behaviour of AA2060 alloy sheet under a wide range of T and ε˙. The predictability of the developed constitutive models was assessed and compared using various statistical parameters, including the correlation coefficient (R), average absolute relative error (AARE), and root mean square error (RMSE). By comparing the results determined from these models and those obtained from experimentations, and confirmed by R, AARE, and RMSE values, it is concluded that the predicted stresses determined from the S2-MJC model align closely with the experimental stresses, demonstrating a remarkable fit compared to the S1-MJC, L-MJC, and MZA models. This is because of the linking impact between softening, the strain rate, and strain hardening in the S2-MJC model. It is widely known that the dislocation process is affected by softening and strain rates. This is attributed to the interactions that occurred between ε and ε˙ from one side and between ε, ε˙, and T from the other side using an extensive set of constants correlating the constitutive components of dynamic recovery and softening mechanisms.

7.
J Cancer Res Ther ; 20(2): 615-624, 2024 Apr 01.
Article de Anglais | MEDLINE | ID: mdl-38687932

RÉSUMÉ

AIM: The accurate reconstruction of cone-beam computed tomography (CBCT) from sparse projections is one of the most important areas for study. The compressed sensing theory has been widely employed in the sparse reconstruction of CBCT. However, the total variation (TV) approach solely uses information from the i-coordinate, j-coordinate, and k-coordinate gradients to reconstruct the CBCT image. MATERIALS AND METHODS: It is well recognized that the CBCT image can be reconstructed more accurately with more gradient information from different directions. Thus, this study introduces a novel approach, named the new multi-gradient direction total variation minimization method. The method uses gradient information from the ij-coordinate, ik-coordinate, and jk-coordinate directions to reconstruct CBCT images, which incorporates nine different types of gradient information from nine directions. RESULTS: This study assessed the efficacy of the proposed methodology using under-sampled projections from four different experiments, including two digital phantoms, one patient's head dataset, and one physical phantom dataset. The results indicated that the proposed method achieved the lowest RMSE index and the highest SSIM index. Meanwhile, we compared the voxel intensity curves of the reconstructed images to assess the edge structure preservation. Among the various methods compared, the curves generated by the proposed method exhibited the highest level of consistency with the gold standard image curves. CONCLUSION: In summary, the proposed method showed significant potential in enhancing the quality and accuracy of CBCT image reconstruction.


Sujet(s)
Algorithmes , Tomodensitométrie à faisceau conique , Traitement d'image par ordinateur , Fantômes en imagerie , Humains , Tomodensitométrie à faisceau conique/méthodes , Traitement d'image par ordinateur/méthodes , Interprétation d'images radiographiques assistée par ordinateur/méthodes , Tête/imagerie diagnostique
8.
Diabetes ; 73(6): 953-963, 2024 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-38506952

RÉSUMÉ

Normal-weight individuals with usual-onset type 2 diabetes have reduced ß-cell function and greater insulin sensitivity compared with their obese counterparts. The relative contribution of ß-cell dysfunction and insulin resistance to young-onset type 2 diabetes (YOD) among normal-weight individuals is not well established. In 44 individuals with YOD (24 with normal weight and 20 with obesity) and 24 healthy control individuals with normoglycemia (12 with normal weight and 12 with obesity), we conducted 2-h 12 mmol/L hyperglycemic clamps to measure acute (0-10 min) and steady-state (100-120 min) insulin and C-peptide responses, as well as insulin sensitivity index. Normal-weight individuals with YOD had lower acute insulin response, steady-state insulin and C-peptide responses, and a higher insulin sensitivity index compared with their obese counterparts with YOD. Compared with BMI-matched healthy control individuals, normal-weight individuals with YOD had lower acute and steady-state insulin and C-peptide responses but a similar insulin sensitivity index. The impairment of steady-state ß-cell response relative to healthy control individuals was more pronounced in normal-weight versus obese individuals with YOD. In conclusion, normal-weight Chinese with YOD exhibited worse ß-cell function but preserved insulin sensitivity relative to obese individuals with YOD and BMI-matched healthy individuals with normoglycemia. The selection of glucose-lowering therapy should account for pathophysiological differences underlying YOD between normal-weight and obese individuals.


Sujet(s)
Peptide C , Diabète de type 2 , Insulinorésistance , Cellules à insuline , Insuline , Obésité , Humains , Diabète de type 2/métabolisme , Diabète de type 2/physiopathologie , Cellules à insuline/métabolisme , Cellules à insuline/physiologie , Insulinorésistance/physiologie , Obésité/métabolisme , Obésité/physiopathologie , Mâle , Femelle , Adulte , Peptide C/sang , Peptide C/métabolisme , Insuline/métabolisme , Insuline/sang , Technique du clamp glycémique , Glycémie/métabolisme , Indice de masse corporelle , Chine/épidémiologie , Âge de début , Asiatiques , Jeune adulte , Études cas-témoins , Peuples d'Asie de l'Est
9.
RMD Open ; 10(1)2024 03 22.
Article de Anglais | MEDLINE | ID: mdl-38519110

RÉSUMÉ

BACKGROUND: This study aims to establish a reliable prediction model of progressive fibrosing interstitial lung disease (PF-ILD) in patients with systemic sclerosis (SSc)-ILD, to achieve early risk stratification and to help better in preventing disease progression. METHODS: 304 SSc-ILD patients with no less than three pulmonary function tests within 6-24 months were included. We collected data at baseline and compared differences between SSc patients with and without PF-ILD. Least absolute shrinkage and selection operator regularisation regression and multivariable Cox regression were used to construct the prediction model, which were presented as nomogram and forest plot. RESULTS: Among the 304 patients with SSc-ILD included, 92.1% were women, with a baseline average age of 46.7 years. Based on the 28 variables preselected by comparison between SSc patients without PF-ILD group (n=150) and patients with SSc PF-ILD group (n=154), a 9-variable prediction model was constructed, including age≥50 years (HR 1.8221, p=0.001), hyperlipidemia (HR 4.0516, p<0.001), smoking history (HR 3.8130, p<0.001), diffused cutaneous SSc subtype (HR 1.9753, p<0.001), arthritis (HR 2.0008, p<0.001), shortness of breath (HR 2.0487, p=0.012), decreased serum immunoglobulin A level (HR 2.3900, p=0.002), positive anti-Scl-70 antibody (HR 1.9573, p=0.016) and usage of cyclophosphamide/mycophenolate mofetil (HR 0.4267, p<0.001). The concordance index after enhanced bootstrap resampling adjustment was 0.874, while the optimism-corrected Brier Score was 0.144 in internal validation. CONCLUSION: This study developed the first prediction model for PF-ILD in patients with SSc-ILD, and internal validation showed favourable accuracy and stability of the model.


Sujet(s)
Pneumopathies interstitielles , Sclérodermie systémique , Humains , Femelle , Adulte d'âge moyen , Mâle , Études de cohortes , Pneumopathies interstitielles/diagnostic , Pneumopathies interstitielles/épidémiologie , Pneumopathies interstitielles/étiologie , Cyclophosphamide , Évolution de la maladie , Sclérodermie systémique/complications
10.
ACS Nano ; 18(12): 8754-8767, 2024 Mar 26.
Article de Anglais | MEDLINE | ID: mdl-38456442

RÉSUMÉ

Concepts of sustainability must be developed to overcome the increasing environmental hazards caused by fossil resources. Cellulose derivatives with excellent properties are promising biobased alternatives for petroleum-derived materials. However, a one-pot route to achieve cellulose dissolution and derivatization is very challenging, requiring harsh conditions, high energy consumption, and complex solubilizing. Herein, we design a one-pot tailoring hydronium ion driven dissociation-chemical cross-linking strategy to achieve superfast cellulose dissolution and derivatization for orderly robust cellulose films. In this strategy, there is a powerful driving force from organic acid with a pKa below 3.75 to dissociate H+ and trigger the dissolution and derivatization of cellulose under the addition of H2SO4. Nevertheless, the driving force can only trigger a partial swelling of cellulose but without dissolution when the pKa of organic acid is above 4.26 for the dissociation of H+ is inhibited by the addition of inorganic acid. The cellulose film has high transmittance (up to ∼90%), excellent tensile strength (∼122 MPa), and is superior to commercial PE film. Moreover, the tensile strength is increased by 400% compared to cellulose film prepared by the ZnCl2 solvent. This work provides an efficient solvent, which is of great significance for emerging cellulose materials from renewable materials.

11.
World J Psychiatry ; 14(2): 315-329, 2024 Feb 19.
Article de Anglais | MEDLINE | ID: mdl-38464778

RÉSUMÉ

BACKGROUND: Sleep deprivation is a prevalent issue that impacts cognitive function. Although numerous neuroimaging studies have explored the neural correlates of sleep loss, inconsistencies persist in the reported results, necessitating an investigation into the consistent brain functional changes resulting from sleep loss. AIM: To establish the consistency of brain functional alterations associated with sleep deprivation through systematic searches of neuroimaging databases. Two meta-analytic methods, signed differential mapping (SDM) and activation likelihood estimation (ALE), were employed to analyze functional magnetic resonance imaging (fMRI) data. METHODS: A systematic search performed according to PRISMA guidelines was conducted across multiple databases through July 29, 2023. Studies that met specific inclu-sion criteria, focused on healthy subjects with acute sleep deprivation and reported whole-brain functional data in English were considered. A total of 21 studies were selected for SDM and ALE meta-analyses. RESULTS: Twenty-one studies, including 23 experiments and 498 subjects, were included. Compared to pre-sleep deprivation, post-sleep deprivation brain function was associated with increased gray matter in the right corpus callosum and decreased activity in the left medial frontal gyrus and left inferior parietal lobule. SDM revealed increased brain functional activity in the left striatum and right central posterior gyrus and decreased activity in the right cerebellar gyrus, left middle frontal gyrus, corpus callosum, and right cuneus. CONCLUSION: This meta-analysis consistently identified brain regions affected by sleep deprivation, notably the left medial frontal gyrus and corpus callosum, shedding light on the neuropathology of sleep deprivation and offering insights into its neurological impact.

12.
Clin Rheumatol ; 43(3): 1083-1092, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38302817

RÉSUMÉ

OBJECTIVE: This study aims to investigate the characteristics, risk factors, and outcomes of digital gangrenes in SSc patients, and to identify whether vasculitis is one of the causes for digital gangrene. METHODS: A retrospective case-control study was performed from February 2003 to April 2021. Forty-three SSc patients with digital gangrene admitted to Peking Union Medical College Hospital were included. One-hundred forty-six age- and sex-matched SSc patients without gangrene were selected as controls during the same period. Univariate and multivariate logistic regression analysis was used to determine risk factors. RESULTS: Among 43 SSc patients with gangrene, 93.0% had Raynaud's phenomenon (RP) and 32.6% had current or previous digital ulcers (DU). SSc patients with digital gangrene had more ESR elevation (54.8% vs. 34.9%, p = 0.020) and higher level of high-sensitive C reactive protein (median 7.2 mg/L vs. 1.8 mg/L, p = 0.045) compared with controls. In the multivariable logistic regression analysis, smoking history (OR 4.119, p = 0.037), anti-centromere antibody positivity (OR 3.542, p = 0.016), anti-neutrophil cytoplasmic antibody positivity (OR 22.605, p = 0.037), and anti-phospholipid antibody positivity (OR 16.563, p = 0.001), as well as elevated ESR (OR 2.524, p = 0.038) were identified as independent risk factors for gangrenes. Most (79.1%) cases were treated with combination of immunosuppressive and vasodilating therapy, and four cases also got remised after treatment of only glucocorticoid and immunosuppressive agent. CONCLUSION: Smoking history; positive-ACA, ANCA, and anti-phospholipid antibodies; and increased ESR were independent risk factors for digital gangrenes in SSc. Vasculitis and macrovascular disease may contribute to the progression of digital gangrenes. Key Points •18.6% of SSc patients with digital gangrene had macrovascular stenosis. •Smoking, positive-ACA, ANCA, aPL, and increased ESR were indicators for digital gangrenes in SSc. •Vasculitis and macrovascular disease may involve in the pathogenesis.


Sujet(s)
Sclérodermie systémique , Vascularite , Humains , Autoanticorps , Gangrène/complications , Anticorps anti-cytoplasme des polynucléaires neutrophiles , Études rétrospectives , Études cas-témoins , Sclérodermie systémique/complications
13.
Carbohydr Polym ; 328: 121749, 2024 Mar 15.
Article de Anglais | MEDLINE | ID: mdl-38220317

RÉSUMÉ

This study presents a novel and environmentally friendly method for producing cellulose microspheres (CM) with controllable morphology and size using electrostatic droplets. The traditional droplet method for CM production requires complex equipment and harmful reagents. In contrast, the proposed method offers a simple electrostatic droplet approach to fabricate CM10 at 10 kV, which exhibited a smaller volume, linear microscopic morphology, and a larger specific surface area, with a 36.60 % improvement compared to CM0 (prepared at 0 kV). CM10 also demonstrated excellent underwater structural stability, recovering in just 0.5 s, and exhibited the highest adsorption capacity for Cr(VI) at 190.16 mg/g, a 72.15 % improvement over CM0. This enhanced adsorption capacity can be attributed to the unique structure of CM10 and the introduction of more amino groups. Moreover, CM10 displayed good cyclic adsorption capacity and high dynamic adsorption efficiency, making it highly suitable for practical applications. CM10 exhibited remarkable adsorption capacity, stability, and practical value in treating Cr(VI) wastewater. This work proposes a simple and eco-friendly method for producing CM with excellent structural controllability and stability, providing an effective route for wastewater treatment.

14.
Sci Adv ; 10(4): eadi5300, 2024 Jan 26.
Article de Anglais | MEDLINE | ID: mdl-38266085

RÉSUMÉ

The constant interplay and information exchange between cells and the microenvironment are essential to their survival and ability to execute biological functions. To date, a few leading technologies such as traction force microscopy, optical/magnetic tweezers, and molecular tension-based fluorescence microscopy are broadly used in measuring cellular forces. However, the considerable limitations, regarding the sensitivity and ambiguities in data interpretation, are hindering our thorough understanding of mechanobiology. Here, we propose an innovative approach, namely, quantum-enhanced diamond molecular tension microscopy (QDMTM), to precisely quantify the integrin-based cell adhesive forces. Specifically, we construct a force-sensing platform by conjugating the magnetic nanotags labeled, force-responsive polymer to the surface of a diamond membrane containing nitrogen-vacancy centers. Notably, the cellular forces will be converted into detectable magnetic variations in QDMTM. After careful validation, we achieved the quantitative cellular force mapping by correlating measurement with the established theoretical model. We anticipate our method can be routinely used in studies like cell-cell or cell-material interactions and mechanotransduction.


Sujet(s)
Communication cellulaire , Mécanotransduction cellulaire , Microscopie à force atomique , Microscopie de fluorescence , Diamant
15.
Sci Rep ; 14(1): 1950, 2024 Jan 23.
Article de Anglais | MEDLINE | ID: mdl-38253674

RÉSUMÉ

Double core-holes (DCHs) show remarkable and sensitive effects for understanding electron correlations and coherence. With advanced modulation of x-ray free-electron laser (XFEL) facility, we propose the forthcoming all-attosecond XFEL pump-probe spectroscopy can decipher the hidden photon-initiated dynamics of DCHs. The benchmark case of neon is investigated, and norm-nonconserving Monte-Carlo wavefunction method simulates non-Hermitian dynamics among vast states, which shows superiority in efficiency and reliability. In our scheme, population transfer to DCHs is sequentially irradiated by pump and probe laser. By varying time delay, Stark shifts and quantum path interference of resonant lines sensitively emerge at specific interval of two pulses. These ubiquitous multi-channel effects are also observed in phase-fluctuating pulses, derived from extra phases of impulsive Raman processes by pump laser. Non-perturbation absorption/emission verifies the uniquely interchangeable role of two pules in higher intensity. Our results reveal sensitive and robust responses on pulse parameters, which show potential capacity for XFEL attosecond pulse diagnosis and further attosecond-timescale chemical analysis.

16.
Int J Biol Macromol ; 261(Pt 2): 129778, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38296126

RÉSUMÉ

Serine proteases possess various biological functions. The serine protease p37k exhibits gelatinolytic activity in the silkworm midgut and degrades cuticular proteins in the molting fluid. In this study, we analyzed the activity changes of recombinant p37k (re-p37k) and p37k in the midgut and molting fluid of Bombyx mori. Firstly, in vitro-expressed re-p37k was activated when a 22 kDa band was observed by western blot. Re-p37k exhibits strong gelatinolytic activity, with the highest activity observed at pH 7.0-9.0 and 45 °C. Compared to p37k in the midgut, re-p37k loses thermal stability but can be restored by midgut extract or ions. E64, AEBSF, and an inhibitor cocktail inhibited the hydrolytic activity of re-p37k on epidermal proteins but did not inhibit the gelatinolytic activity. Subsequently, zymography showed that the positions of gelatinolytic band produced by p37k in the midgut and molting fluid were different, 35 kDa and 40 kDa, respectively. Finally, when heated midgut extract was added to re-p37k or molting fluid, the gelatinolytic band shifted from 40 kDa to 35 kDa, and the proteolytic activity of p37k in the molting fluid was inhibited. Collectively, our results demonstrate that p37k exhibits different activities in various tissues, suggesting its distinct tissue-specific functions during insect metamorphosis.


Sujet(s)
Bombyx , Mue , Animaux , Protéases à sérine/métabolisme , Bombyx/métabolisme , Larve/métabolisme , Serine endopeptidases/métabolisme , Protéines d'insecte/métabolisme
17.
Laryngoscope ; 134(2): 937-944, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-37421255

RÉSUMÉ

OBJECTIVE: Our team designed a long-lasting, well-sealed microphone, which uses laser welding and vacuum packaging technology. This study examined the sensitivity and effectiveness of this new floating piezoelectric microphone (NFPM) designed for totally implantable cochlear implants (TICIs) in animal experiments and intraoperative testing. METHODS: Different NFPM frequency responses from 0.25 to 10 kHz at 90 dB SPL were analyzed using in vivo testing of cats and human patients. The NFPM was tested in different positions that were clamped to the ossicular chains or placed in the tympanic cavity of cats and human patients. Two volunteers' long incus foot and four cats' malleus neck of the ossicular chain were clamped with the NSFM. The output electrical signals from different locations were recorded, analyzed, and compared. The NFPM was removed after the test without causing any damage to the middle-ear structure of the cats. Intraoperative tests of the NFPM were performed during the cochlear implant surgery and the cochlear implant surgery was completed after all tests. RESULTS: Compared with the results in the tympanic cavity, the NFPM could detect the vibration from the ossicular chain more sensitively in cat experiments and intraoperative testing. We also found that the signal output level of the NFPM decreased as the acoustic stimulation strength decreased in the intraoperative testing. CONCLUSION: The NFPM is effective in the intraoperative testing, making it feasible as an implantable middle-ear microphone for TICIs. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:937-944, 2024.


Sujet(s)
Implantation cochléaire , Implants cochléaires , Animaux , Humains , Conception de prothèse , Oreille moyenne/chirurgie , Osselets de l'audition/chirurgie
18.
Int J Biol Macromol ; 257(Pt 2): 128715, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-38081484

RÉSUMÉ

Hydrogels with excellent high-water uptake and flexibility have great potential for wound dressing. However, pure hydrogels without fiber skeleton faced poor water retention, weak fatigue resistance, and mechanical strength to hinder the development of the dressing as next-generation functional dressings. We prepared an ultrafast gelation (6 s) Fe3+/TA-CNC hydrogel (CTFG hydrogel) based on a self-catalytic system and bilayer self-assembled composites. The CTFG hydrogel has excellent flexibility (800% of strain), fatigue resistance (support 60% compression cycles), antibacterial, and self-adhesive properties (no residue or allergy after peeling off the skin). CTFG@S bilayer composites were formed after electrospun silk fibroin (SF) membranes were prepared and adhesive with CTFG hydrogels. The CTFG@S bilayer composites had significant UV-shielding (99.95%), tensile strain (210.9 KPa), and sensitive humidity-sensing properties. Moreover, the integrated structure improved the mechanical properties of electrospun SF membranes. This study would provide a promising strategy for rapidly preparing multifunctional hydrogels for wound dressing.


Sujet(s)
Cellulose , Fibroïne , Polyphénols , Céments résine , Bandages , Antibactériens/pharmacologie , Hydrogels , Eau
19.
Int J Biol Macromol ; 254(Pt 3): 128046, 2024 Jan.
Article de Anglais | MEDLINE | ID: mdl-37956816

RÉSUMÉ

The packaging of fresh foods increasingly focuses on renewable and eco-friendly cellulose films, but their low dissolution efficiency and weak mechanical strength greatly limit their wide application, which also cannot be used for smart packaging. Here, a highly efficient synergistic chloride-salt dissolution method was proposed to fabricate robust, transparent, and smart cellulose films. Cellulose films with appropriate Ca2+ concentration exhibited robust mechanical strength, better thermal stability, high transparency and crystallinity. The metal chelation of Ca2+ with cellulose chains could induce cellulose chain arrangement during the cellulose regeneration process. Particularly, compared to pure cellulose films, the tensile strength and elongation at break of cellulose films with suitable Ca2+ were increased by 167 % and 200 %, respectively. Moreover, optimal cellulose films can be used to reflect the quality of the fruit by detecting changes in ethanol gas. Hence, a novel strategy is presented to fabricate robust and transparent cellulose films with great potential application for smart packaging.


Sujet(s)
Cellulose , Emballage de produit , Emballage de médicament , Résistance à la traction , Emballage alimentaire
20.
Int J Biol Macromol ; 254(Pt 2): 127866, 2024 Jan.
Article de Anglais | MEDLINE | ID: mdl-37939769

RÉSUMÉ

The widespread use of petroleum-based plastic mulch in agriculture has accelerated white and microplastic pollution while posing a severe agroecological challenge due to its difficulty in decomposing in the natural environment. However, endowing mulch film with degradability and growth cycle adaptation remains elusive due to the inherent non-degradability of petroleum-based plastics severely hindering its applications. This work reports polylactic acids hyperbranched composite mulch (PCP) and measured biodegradation behavior under burial soil, seawater, and ultraviolet (UV) aging to understand the biodegradation kinetics and to increase their sustainability in the agriculture field. Due to high interfacial interactions between polymer and nanofiler, the resultant PCP mulch significantly enhances crystallization ability, hydrophilicity, and mechanical properties. PCP mulch can be scalable-manufactured to exhibit modulated degradation performance under varying degradation conditions and periods while concurrently enhancing crop growth (wheat). Thus, such mulch with excellent performance can reduce labor costs and the environmental impact of waste mulch disposal to replace traditional mulch for sustainable agricultural production.


Sujet(s)
Nanoparticules , Pétrole , Cellulose , Matières plastiques , Sol/composition chimique , Agriculture , Dépollution biologique de l'environnement
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...