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1.
BMC Cancer ; 24(1): 396, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553708

RESUMO

BACKGROUND: Emerging data suggested a favorable outcome in advanced non-small cell lung cancer (NSCLC) with chronic obstructive pulmonary disease (COPD) patients treated by immunotherapy. The objective of this study was to investigate the effectiveness of neoadjuvant immunotherapy among NSCLC with COPD versus NSCLC without COPD and explore the potential mechanistic links. PATIENTS AND METHODS: Patients with NSCLC receiving neoadjuvant immunotherapy and surgery at Shanghai Pulmonary Hospital between November 2020 and January 2023 were reviewed. The assessment of neoadjuvant immunotherapy's effectiveness was conducted based on the major pathologic response (MPR). The gene expression profile was investigated by RNA sequencing data. Immune cell proportions were examined using flow cytometry. The association between gene expression, immune cells, and pathologic response was validated by immunohistochemistry and single-cell data. RESULTS: A total of 230 NSCLC patients who received neoadjuvant immunotherapy were analyzed, including 60 (26.1%) with COPD. Multivariate logistic regression demonstrated that COPD was a predictor for MPR after neoadjuvant immunotherapy [odds ratio (OR), 2.490; 95% confidence interval (CI), 1.295-4.912; P = 0.007]. NSCLC with COPD showed a down-regulation of HERV-H LTR-associating protein 2 (HHLA2), which was an immune checkpoint molecule, and the HHLA2low group demonstrated the enrichment of CD8+CD103+ tissue-resident memory T cells (TRM) compared to the HHLA2high group (11.9% vs. 4.2%, P = 0.013). Single-cell analysis revealed TRM enrichment in the MPR group. Similarly, NSCLC with COPD exhibited a higher proportion of CD8+CD103+TRM compared to NSCLC without COPD (11.9% vs. 4.6%, P = 0.040). CONCLUSIONS: The study identified NSCLC with COPD as a favorable lung cancer type for neoadjuvant immunotherapy, offering a new perspective on the multimodality treatment of this patient population. Down-regulated HHLA2 in NSCLC with COPD might improve the MPR rate to neoadjuvant immunotherapy owing to the enrichment of CD8+CD103+TRM. TRIAL REGISTRATION: Approval for the collection and utilization of clinical samples was granted by the Ethics Committee of Shanghai Pulmonary Hospital (Approval number: K23-228).


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Doença Pulmonar Obstrutiva Crônica , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/genética , Terapia Neoadjuvante , China , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/terapia , Imunoterapia , Imunoglobulinas
2.
Small ; : e2309096, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054612

RESUMO

Recently, nanozyme-based photothermal-catalytic therapy has emerged as a promising strategy for antitumor treatment. Extensive research has focused on optimizing the catalytic activity and photothermal conversion performance of nanozymes through size, morphology, and surface property regulations. However, the biological effects of nanozymes, such as cellular uptake and cytotoxicity, resulting from their physicochemical properties, remain largely unexplored. In this study, two types of polydopamine/platinum (PDA@Pt) nanozymes, flower-like (FPDA@Pt) and mesoporous spherical-like (MPDA@Pt), to comprehensively compare their enzyme-mimicking activity, photothermal conversion capacity, and antitumor efficiency are designed. These findings revealed that FPDA@Pt exhibited superior peroxidase-like activity and higher photothermal conversion efficiency compared to MPDA@Pt. This led to enhanced production of reactive oxygen species (ROS) and increased heat generation at tumor sites. Importantly, it is observed thatthe flower-like structure of FPDA@Pt facilitated enhanced cellular uptake, leading to an increased accumulation of nanozymes within tumor cells. Furthermore, the light irradiation on tumors also triggered a series of anti-tumor immune responses, further enhancing the therapeutic efficacy. This work provides a possible design orientation for nanozyme-based photothermal-catalytic tumor therapy, highlighting the importance of considering the physicochemical properties of nanozymes to optimize their therapeutic potential in antitumor strategies.

3.
Sensors (Basel) ; 23(19)2023 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-37837137

RESUMO

The grinding grooves of material removal machining and the residues of a machining tool on the key component surface cause surface stress concentration. Thus, it is critical to carry out precise measurements on the key component surface to evaluate the stress concentration. Based on white-light interferometry (WLI), we studied the measurement distortion caused by the reflected light from the steep side of the grinding groove being unable to return to the optical system for imaging. A threshold value was set to eliminate the distorted measurement points, and the cubic spline algorithm was used to interpolate the eliminated points for compensation. The compensation result agrees well with the atomic force microscope (AFM) measurement result. However, for residues on the surface, a practical method was established to obtain a microscopic 3D micro-topography point cloud and a super-depth-of-field fusion image simultaneously. Afterward, the semantic segmentation network U-net was adopted to identify the residues in the super-depth-of-field fusion image and achieved a recognition accuracy of 91.06% for residual identification. Residual feature information, including height, position, and size, was obtained by integrating the information from point clouds and super-depth-of-field fusion images. This work can provide foundational data to study surface stress concentration.

4.
J Nanobiotechnology ; 20(1): 199, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35473696

RESUMO

BACKGROUND: Ferroptosis holds promise as a potential tumor therapy by programming cell death with a hallmark of reactive oxygen species (ROS)-induced lipid peroxidation. However, vigorous energy metabolism may assist tumors to resist oxidative damage and thus weaken the effects of ferroptosis in tumor treatment. RESULTS: Herein, a bifunctional antitumor platform was constructed via coordinated interactions between metal ions and nucleotides to synergistically activate ferroptosis and interrupt energy metabolism for tumor therapy. The designed nanoparticles were composed of Fe2+/small interfering RNA (siRNA) as the core and polydopamine as the cloak, which responded to the tumor microenvironment with structural dissociation, thereby permitting tumor-specific Fe2+ and siRNA release. The over-loaded Fe2+ ions in the tumor cells then triggered ferroptosis, with hallmarks of lipid peroxidation and cellular glutathione peroxidase 4 (GPX4) down-regulation. Simultaneously, the released siRNA targeted and down-regulated glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression in the tumor to inhibit glycolytic pathway, which interfered with tumor energy metabolism and enhanced Fe2+-induced ferroptosis to kill tumor cells. CONCLUSIONS: This study presents a concise fabrication of a metal ion/nucleotide-based platform to integrate ferroptosis and energy metabolism intervention in one vehicle, thereby providing a promising combination modality for anticancer therapy.


Assuntos
Ferroptose , Nanopartículas , Íons , Peroxidação de Lipídeos , Nucleotídeos , RNA Interferente Pequeno
5.
Small ; 17(13): e2005473, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33661558

RESUMO

Recent progress in nanotechnology and the ancient use of sulfur in treating dermatological disorders have promoted the development of nano-sulfides for antimicrobial applications. However, the variable valences and abundant forms of nano-sulfides have complicated investigations on their antibacterial activity. Here, carbon nanospheres (CNSs) with decoration of ultrasmall FeS2 nanoparticles (CNSs@FeS2 ) is synthesized, and their antibacterial ability and mechanism are explored. The CNSs@FeS2 released Fe2+ and sulfur ions simultaneously through dissolution and disproportionation. In vitro study indicated that the released Fe2+ killed bacteria by increasing the oxidative state of bacterial surfaces and intracellular molecules. Importantly, the released sulfur exhibited a protective effect on Fe2+ , ensuring the stable existence of Fe2+ to continuously combat bacteria. Moreover, the carbon shells of CNSs@FeS2 not only prevented the aggregation of FeS2 but also accelerated the release of Fe2+ through photothermal effects to achieve synergistic hyperthermia/Fe2+ therapy. In vivo experiments indicated that treatment with CNSs@FeS2 resulted in a marked reduction in bacterial number and improvement in survival in an acute peritonitis mouse model, and antibacterial wound experiments demonstrated high efficacy of CNSs@FeS2 -enabled synergistic hyperthermia/Fe2+ therapy. Thus, this study clarifies the antibacterial mechanism of FeS2 and offers a synergetic therapeutic platform with laser-mediated Fe2+ release for antibacterial applications.


Assuntos
Carbono , Nanopartículas , Animais , Antibacterianos/farmacologia , Ferro , Lasers , Camundongos
6.
Opt Express ; 29(3): 3309-3326, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33770932

RESUMO

The directional polarimetric camera (DPC) is a polarization sensor with the characteristics of ultra-wide-angle and low-distortion imaging. The multi-angle polarization information is helpful to obtain the spatial distribution of target radiation, and multiple data fusion relies on the non-uniformity calibration of image plane. The non-uniformity consists of many factors such as lens, detector assembly, spatial stray light, etc. The single correction method can not distinguish the error source effectively. In consideration of the in-flight operation mode of DPC based on the adjustment of exposure time, the non-uniformity correction method of the detector based on multi parameters is proposed. Through the electro-optical performance measurement system of the CCD detector, the sensitive factors such as temperature, dark current, exposure time and spectral response are obtained. After a series of preprocessing of the image including removal of dark signal, removal of smearing effect and temperature compensation, the non-uniformity calibration based on multi-parameters is imposed on the detector. The low-frequency unbalanced response difference of the image surface is eliminated, and the high-frequency difference is effectively suppressed. The experimental results show that the photo response non-uniformity of 95% full well single frame data is reduced from 2.86% to 0.36%. After correction, the data noise is shown as shot noise, and the detector has good ability of dynamic range adjustment. The non-uniformity calibration by the proposed method can offer data support for the instrumental calibration and in-flight fast calculation, and provide effective reference for the subsequent polarization remote sensing instruments.

7.
Langmuir ; 37(5): 2001-2010, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33502210

RESUMO

Recently, carbon nanomaterials doped with nonmetallic atoms have been used as electrocatalysts involved in oxygen reduction reactions (ORRs) because of the lack of degradation and contamination problems caused by metal dissolution, low cost, sustainability, and multifunctionality. In this study, the metal-free N-, P-, O-tridoped carbon hollow nanospheres (N, P, O-Carbon) with openings in the shell surfaces have been developed, where poly(o-phenylenediamine) hollow nanospheres with openings in the shell surfaces were chosen as a nitrogen-rich polymer, and then different phosphorus sources (such as NaH2PO2, H3PO4, and phytic acid (PA)) were introduced for heat treatment. When used as electrocatalysts, N, P, O-Carbon-PA showed the best ORR electroactivity with an onset potential (Eonset) of 0.98 V and the limit current density of 5.39 mA cm-2. The origin of high activity associated with heteroatom doping was elucidated by X-ray photoelectron spectroscopy and density functional theory. The results evidenced the high potential of N, P, O-Carbon as highly active nonmetal ORR electrocatalysts. It can be expected that the conclusions rendered herein will provide guidance for the reasonable design of other heteroatom-doped carbon for wider applications.

8.
Langmuir ; 37(23): 7067-7077, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34080864

RESUMO

Lamellar liquid crystals have amazing lubricating and drug-solubilizing properties. Hence, the combination of drug molecules with lamellar liquid crystals is expected to be used in joint lubrication and treatment. In this study, the partial phase diagram of the Tween 85/Tween 80/H2O three-component system was determined. The phase structure of the system changed from a hexagonal liquid crystal to a lamellar liquid crystal with the increase of Tween 85 content. The lamellar liquid crystals showed superior lubricating properties due to their unique lamellar structure. Furthermore, the model of drug release during friction was established for the first time. It was found that the order of the lamellar liquid crystals increased with the increase of the mass ratio of Tween 85/Tween 80, leading to the decrease of the ibuprofen release rate. In addition, the release rate of ibuprofen increased progressively with the increase of the friction frequency, but the load had little effect on it. Therefore, the lamellar liquid crystals consisting of nonionic surfactants with good biocompatibility have potential application prospects for joint lubrication and treatment of arthritis.

9.
Soft Matter ; 17(20): 5137-5147, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33881132

RESUMO

In this work, a benzoate ester molecule, dodecamethylnonacosane-2,28-diyl dibenzoate (DMNDB), has been discovered as a new species that aggregates into chiral nano-assemblies. In the tetrahydrofuran (THF)/water system, the benzoate ester, DMNDB, could self-assemble into left-handed twisted nanowires, and the most suitable THF/water volume ratio to obtain uniform twisted nanowires was 3 : 7. The driving forces of assembly and the molecular packing type in assemblies for the twisted nanowires were explored, and a possible assembly mechanism was proposed to understand the generation of chiral assemblies. Interestingly, the left-handed nanowires could cross-link and immobilize the solvent in the isopropanol (iPrOH)/water (2 : 8) system to form chiral gels. When the iPrOH/water ratio was increased to 6 : 4, the left-handed nanowires as structural units were found to evolve to right-handed nanofibers. Accordingly, the intermolecular interactions and the molecular packing type also changed with the solvent ratio. What is more, the xerogel could be obtained by drying the gel and left-handed twisted nanowires could form in the THF/water system again, showing the recyclability of chiral nanoassemblies. Also, these DMNDB chiral nanostructures exhibited potential for application in enantioselective separation by co-assembling with tetra-aniline.

10.
Microb Cell Fact ; 19(1): 191, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028330

RESUMO

BACKGROUND: Nowadays, microbial infections have caused increasing economic losses in aquaculture industry and deteriorated worldwide environments. Many of these infections are caused by opportunistic pathogens through cell-density mediated quorum sensing (QS). The disruption of QS, known as quorum quenching (QQ), is an effective and promising way to prevent and control pathogens, driving it be the potential bio-control agents. In our previous studies, AHL lactonase AiiK was identified with many characteristics, and constitutive expression vector pELX1 was constructed to express heterologous proteins in Lactobacillus casei MCJΔ1 (L. casei MCJΔ1). In this study, recombinant strain pELCW-aiiK/L. casei MCJΔ1 (LcAiiK) and wild-type Aeromonas hydrophila (A. hydrophila) were co-cultured to test the QQ ability of LcAiiK against A. hydrophila. RESULTS: A cell wall-associated expression vector pELCW for L. casei MCJΔ1 was constructed. Localization assays revealed that the expressed AiiK was anchored at the surface layer of LcAiiK via vector pELCW-aiiK. LcAiiK (OD600 = 0.5) degraded 24.13 µM of C6-HSL at 2 h, 40.99 µM of C6-HSL at 12 h, and 46.63 µM of C6-HSL at 24 h. Over 50% LcAiiK cells maintained the pELCW-aiiK plasmid after 15 generations of cultivation without erythromycin. Furthermore, LcAiiK inhibited the swimming motility, extracellular proteolytic activity, haemolytic activity and biofilm formation of A. hydrophila AH-1 and AH-4. CONCLUSION: The AHL lactonase AiiK is firstly and constitutively expressed at the surface layer of L. casei MCJΔ1. LcAiiK displayed considerable AHL lactonase activity and great QQ abilities against A. hydrophila AH-1 and AH-4 by attenuating their QS processes instead of killing them. Therefore, the LcAiiK can be exploited as an anti-pathogenic drug or a bio-control agent to control the AHL-mediated QS of pathogenic bacteria.


Assuntos
Aeromonas hydrophila/metabolismo , Hidrolases de Éster Carboxílico/genética , Lacticaseibacillus casei/genética , Percepção de Quorum , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , Agentes de Controle Biológico , Hidrolases de Éster Carboxílico/metabolismo , Lacticaseibacillus casei/metabolismo
11.
Clin Lab ; 66(4)2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32255290

RESUMO

BACKGROUND: The current study aims to investigate the expression of lncRNA BLACAT1 in patients with acute myeloid leukemia (AML) and to analyze its correlation with clinical prognosis. METHODS: Peripheral blood samples were collected from 68 AML patients, including 48 patients with acute myeloid leukemia (AML), 20 patients with complete response (CR), and 30 patients with iron deficiency anemia (control group). LncRNA BLACAT1 was detected by real-time fluorescence quantitative PCR (qRT-PCR). The expression of BLACAT1 and its relationship with clinicopathological characteristics and prognosis were analyzed. RESULTS: The expression of lncRNA BLACAT1 in AML patients was significantly higher than that in complete remission patients and iron deficiency anemia patients, but the expression of lncRNA BLACAT1 in AML-CR group and control group had no significant difference. Further study showed that the expression of lncRNA BLACAT1 was correlated with the National Comprehensive Cancer Network (NCCN) risk classification, the amount of platelet and bone marrow primordial cells (%), and survival status of patients. The median overall survival time of patients with high expression of lncRNA BLACAT1 was significantly shorter than those with low expression of lncRNA BLACAT1 (p < 0.05). CONCLUSIONS: LncRNA BLACAT1 was involved in regulating the occurrence and development of AML and can be used as a potential prognostic marker and therapeutic target for AML patients.


Assuntos
Biomarcadores Tumorais/genética , Regulação Leucêmica da Expressão Gênica , Leucemia Mieloide/genética , RNA Longo não Codificante/genética , Doença Aguda , Adulto , Biomarcadores Tumorais/sangue , Feminino , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Longo não Codificante/sangue
12.
Nano Lett ; 19(11): 7645-7654, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31580681

RESUMO

Metal-carbon hybrid materials have shown promise as potential enzyme mimetics for antibacterial therapy; however, the effects of metal states and corresponding antibacterial mechanisms are largely unknown. Here, two kinds of copper/carbon nanozymes were designed, with tuned copper states from Cu0 to Cu2+. Results revealed that the copper/carbon nanozymes exhibited copper state-dependent peroxidase-, catalase-, and superoxide dismutase-like activities. Furthermore, the antibacterial activities were also primarily determined by the copper state. The different antibacterial mechanisms of these two copper/carbon nanozymes were also proposed. For the CuO-modified copper/carbon nanozymes, the released Cu2+ caused membrane damage, lipid peroxidation, and DNA degradation of Gram-negative bacteria, whereas, for Cu-modified copper/carbon nanozymes, the generation of reactive oxygen species (ROS) via peroxidase-like catalytic reactions was the determining factor against both Gram-positive and Gram-negative bacteria. Lastly, we established two bacterially infected animal models, i.e., bacteria-infected enteritis and wound healing, to confirm the antibacterial ability of the copper/carbon nanozymes. Our findings provide a deeper understanding of metal state-dependent enzyme-like and antibacterial activities and highlight a new approach for designing novel and selective antibacterial therapies based on metal-carbon nanozymes.


Assuntos
Antibacterianos/farmacologia , Carbono/farmacologia , Cobre/farmacologia , Nanoestruturas , Antibacterianos/química , Infecções Bacterianas/tratamento farmacológico , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Carbono/química , Catalase/química , Catálise , Cobre/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/metabolismo , Humanos , Nanoestruturas/química , Peroxidases/química , Espécies Reativas de Oxigênio/metabolismo
14.
J Exp Bot ; 65(6): 1651-71, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24600016

RESUMO

Fruit ripening is a complex, genetically programmed process that occurs in conjunction with the differentiation of chloroplasts into chromoplasts and involves changes to the organoleptic properties of the fruit. In this study, an integrative analysis of the transcriptome and proteome was performed to identify important regulators and pathways involved in fruit ripening in a spontaneous late-ripening mutant ('Fengwan' orange, Citrus sinensis L. Osbeck) and its wild type ('Fengjie 72-1'). At the transcript level, 628 genes showed a 2-fold or more expression difference between the mutant and wild type as detected by an RNA sequencing approach. At the protein level, 130 proteins differed by 1.5-fold or more in their relative abundance, as indicated by iTRAQ (isobaric tags for relative and absolute quantitation) analysis. A comparison of the transcriptome and proteome data revealed some aspects of the regulation of metabolism during orange fruit ripening. First, a large number of differential genes were found to belong to the plant hormone pathways and cell-wall-related metabolism. Secondly, we noted a correlation between ripening-associated transcripts and sugar metabolites, which suggests the importance of these metabolic pathways during fruit ripening. Thirdly, a number of genes showed inconsistency between the transcript and protein level, which is indicative of post-transcriptional events. These results reveal multiple ripening-associated events during citrus ripening and provide new insights into the molecular mechanisms underlying citrus ripening regulatory networks.


Assuntos
Ácido Abscísico/metabolismo , Citrus sinensis/genética , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Proteoma , Transcriptoma , Ácido Abscísico/análise , Ácidos Carboxílicos/metabolismo , Parede Celular/metabolismo , Clorofila/metabolismo , Citrus sinensis/crescimento & desenvolvimento , Citrus sinensis/metabolismo , Etilenos/análise , Etilenos/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Modelos Biológicos , Fenótipo , Reguladores de Crescimento de Plantas/análise , Proteínas de Plantas/metabolismo , Análise de Sequência de RNA , Especificidade da Espécie , Sacarose
15.
Micromachines (Basel) ; 15(5)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38793228

RESUMO

Many micro-scraps are generated when a micro-triangular pyramid array (MTPA) is machined by the fly-cutting method. Micro-scraps are generally not removed quickly enough; therefore, these residual micro-scraps participate in the cutting process again, scratching the workpiece surface and accelerating diamond tool wear. To remove micro-scraps rapidly, a fly-cutting method to produce MTPAs on vertically oriented working surfaces was developed during this study. The results show that an MTPA produced by fly cutting on a vertical workpiece had a clearly outlined structure, high dimensional accuracy, and a low surface roughness. There was no micro-scrap residue on the workpiece surface and the diamond tool wear was small. The cutting inlet edges had no burrs, and the cutting outlet edges had only a small number of burrs. This method of fly cutting MTPAs on vertically oriented working surfaces provides a foundation for the development of high-precision micro-triangular pyramid optical elements.

16.
Food Chem ; 445: 138701, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38350203

RESUMO

Multi-frequency ultrasound-assisted thawing (MUAT) has been proven to be an effective method of maintaining the quality of frozen food. The effects of magnetic nano-particles (MNPs) combined with MUAT and multi-frequency ultrasound-assisted sequential thawing (MUST) on water retention, myofibrillar protein (MP) structural characteristics, function characteristics, and MP aggregation and degradation of salmon (Salmo salar) were studied. The results showed that MNPs combined with multi-frequency ultrasound-assisted sequential thawing (MNPs-MUST) significantly improved the thawing rate and the retention of water and had better emulsifying and foaming properties. MNPs-MUST treatment reduced the oxidation and degradation of MP, increased sulfhydryl content, and protected the structure of MP. Confocal laser scanning microscopy (CLSM) indicated that the MP transformed into a filamentous polymer into more evenly distributed units, resulting in higher protein solubility, lower surface hydrophobicity, and lower protein turbidity. Therefore, MNPs combined with MUST has a potential application value in the thawing research of frozen salmon.


Assuntos
Salmo salar , Animais , Proteínas , Alimentos Marinhos , Água/química , Fenômenos Magnéticos
17.
Materials (Basel) ; 17(6)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38541536

RESUMO

The demand for titanium alloy has been increasing in various industries, including aerospace, marine, and biomedical fields, as they fulfilled the need for lightweight, high-strength, and corrosion-resistant material for modern manufacturing. However, titanium alloy has relatively low hardness, poor wear performance, and fatigue properties, which limits its popularization and application. These disadvantages could be efficiently overcome by surface strengthening technology, such as the ultrasonic surface rolling process (USRP). In this study, the true thermo-mechanical deformation behavior of Ti-6Al-4V was obtained by dynamic mechanical experiment using a Hopkinson pressure bar. Moreover, USRP was applied on the Ti-6Al-4V workpiece with different parameters of static forces to investigate the evolution in surface morphology, surface roughness, microstructure, hardness, residual stress, and fatigue performance. The strain rate and temperature during the USRP of Ti-6Al-4V under the corresponding conditions were about 3000 s-1 and 200 °C, respectively, which were derived from the numerical simulation. The correlation between the true thermo-mechanical behavior of Ti-6Al-4V alloy and the USRP parameters of the Ti-6Al-4V workpiece was established, which could provide a theoretical contribution to the optimization of the USRP parameters. After USRP, the cross-sectional hardness distribution of the workpiece was shown to initially rise, followed by a subsequent decrease, ultimately to matrix hardness. The cross-sectional residual compressive stress distribution of the workpiece showed a tendency to initially reduce, then increase, and finally decrease to zero. The fatigue performance of the workpiece was greatly enhanced after USRP due to the effect of grain refinement, work hardening, and beneficial residual compressive stress, thereby inhibiting the propagation of the fatigue crack. However, it could be noted that the excessive static force parameter of USRP could induce the decline in surface finish and compressive residual stress of the workpiece, which eliminated the beneficial effect of the USRP treatment. This indicated that the choice of the optimal USRP parameters was highly crucial. This work would be conducive to achieving high-efficiency and low-damage USRP machining, which could be used to effectively guide the development of high-end equipment manufacturing.

18.
Materials (Basel) ; 17(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38893987

RESUMO

Ultrasonic rolling is an effective technique for enhancing surface integrity, and surface integrity is closely related to fatigue performance. The process parameters of ultrasonic rolling critically affect the improvement of surface integrity. This study proposes an optimization method for process parameters by combining machine learning (ML) with the NSGA-II. Five ML models were trained to establish relationships between process parameters and surface residual stress, hardness, and surface roughness by incorporating feature augmentation and physical information. The best-performing model was selected and integrated with NSGA-II for multi-objective optimization. Ultrasonic rolling tests based on a uniform design were performed, and a dataset was established. The objective was to maximize surface residual stress and hardness while minimizing surface roughness. For test specimens with an initial surface roughness of 0.54 µm, the optimized process parameters were a static pressure of 900 N, a spindle speed of 75 rpm, a feed rate of 0.19 mm/r, and rolling once. Using optimized parameters, the surface residual stress reached -920.60 MPa, surface hardness achieved 958.23 HV, surface roughness reduced to 0.32 µm, and contact fatigue life extended to 3.02 × 107 cycles, representing a 52.5% improvement compared to untreated specimens and an even more significant improvement over without parameter optimization.

19.
Crit Rev Anal Chem ; : 1-25, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376891

RESUMO

Vitamin D deficiency is thought to be associated with a wide range of diseases, including diabetes, cancer, depression, neurodegenerative diseases, and cardiovascular and cerebrovascular diseases. This vitamin D deficiency is a global epidemic affecting both developing and developed countries and therefore qualitative and quantitative analysis of vitamin D in a clinical context is essential. Mass spectrometry has played an increasingly important role in the clinical analysis of vitamin D because of its accuracy, sensitivity, specificity, and the ability to detect multiple substances at the same time. Despite their many advantages, mass spectrometry-based methods are not without analytical challenges. Front-end and back-end challenges such as protein precipitation, analyte extraction, derivatization, mass spectrometer functionality, must be carefully considered to provide accurate and robust analysis of vitamin D through a well-designed approach with continuous control by internal and external quality control. Therefore, the aim of this review is to provide a comprehensive overview of the development of mass spectrometry methods for vitamin D accurate analysis, including emphasis on status markers, deleterious effects of biological matrices, derivatization reactions, effects of ionization sources, contribution of epimers, standardization of assays between laboratories.

20.
Cancer Med ; 13(6): e7112, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38509769

RESUMO

BACKGROUND: Patients with non-small cell lung cancer (NSCLC) and chronic obstructive pulmonary disease (COPD) experience worse clinical outcomes but respond better to immunotherapy than patients with NSCLC without COPD. Mucosal-associated invariant T (MAIT) cells, a versatile population of innate immune T lymphocytes, have a crucial function in the response to infection and tumors. This study investigated the distribution of MAIT cells in COPD-associated NSCLC and their involvement in the immune response. METHODS: Flow cytometry, immunohistochemistry, and immunofluorescence were performed on tissue samples of patients with NSCLC, with or without COPD, treated with or without anti-programmed death 1 (PD1) immunotherapy. MAIT cells were stimulated with 5-OP-RU using a mouse subcutaneous tumor model. RESULTS: Tumors contained significantly more MAIT cells than paraneoplastic tissues, and CD8+ MAIT cells accounted for more than 90% of these cells. Patients with NSCLC and COPD had higher CD8+ MAIT cell counts than those with NSCLC without COPD. Additionally, patients with NSCLC and COPD displayed reduced expression of the activation marker, CD69, and functional markers, granzyme B (GZMB) and interferon γ (IFNγ), and higher expression of the immune exhaustion marker, PD1. Among patients who received immunotherapy, the proportion with a complete or partial response was higher in those with COPD than in those without COPD. In patients with NSCLC and COPD, the major pathologic response (MPR) group had higher MAIT levels than those in the no major pathologic response (NPR) group. In the mouse subcutaneous tumor model stimulation of MAIT cells using 5-OP-RU enhanced the antitumor effects of anti-PD1. CONCLUSIONS: In patients with NSCLC and COPD, response to immunotherapy is associated with accumulation of CD8+ MAIT cells showing immune exhaustion. These findings may contribute to innovative approaches for immunotherapy targeting CD8+ MAIT cells.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Células T Invariantes Associadas à Mucosa , Doença Pulmonar Obstrutiva Crônica , Ribitol/análogos & derivados , Uracila/análogos & derivados , Humanos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Células T Invariantes Associadas à Mucosa/metabolismo , Células T Invariantes Associadas à Mucosa/patologia , Neoplasias Pulmonares/metabolismo , Terapia Neoadjuvante , Biomarcadores/metabolismo , Doença Pulmonar Obstrutiva Crônica/terapia , Imunoterapia
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