RESUMO
Highly sensitive and selective choline microbiosensors were constructed by microcontact printing (µCP) of choline oxidase (ChOx) in a crosslinked, polyamine-functionalized zwitterionic polymer matrix on microelectrode arrays (MEAs). µCP has emerged as a potential means to create implantable, multiplexed sensor microprobes, which requires the targeted deposition of different sensor materials to specific microelectrode sites on a MEA. However, the less than sufficient enzyme loading and inadequate spatial resolution achieved with current µCP approaches has limited adoption of the method for electroenzymatic microsensors. A novel polymer, poly(2-methacryloyloxyethyl phosphorylcholine)-g-poly(allylamine hydrochloride) (PMPC-g-PAH), has been developed to address this challenge. PMPC-g-PAH contributes to a higher viscosity "ink" that enables thicker immobilized ChOx deposits of high spatial resolution while also providing a hydrophilic, biocompatible microenvironment for the enzyme. Electroenzymatic choline microbiosensors with sensitivity of 639 ± 96 nA µM-1 cm-2 (pH 7.4; n = 4) were constructed that also are selective against both ascorbic acid and dopamine, which are potential electroactive interfering compounds in the mammalian brain. The high sensitivities achieved can lead to smaller MEA microprobes that minimize tissue damage and make possible the monitoring of multiple neurochemicals simultaneously in vivo with high spatial resolution.
Assuntos
Oxirredutases do Álcool , Polímeros , Animais , Colina , MamíferosRESUMO
The sesquiterpenoid hormone methyl farnesoate (MF) plays a vital role during crustacean development, which is mainly evidenced by its varied titers during different developmental stages. However, the biosynthesis pathways of MF remain obscure to some extent. In this study, we identified the complete MF biosynthesis and related pathway genes in Scylla paramamosain, including three involved in acetyl-CoA metabolism, eight in the mevalonate pathway, five in the sesquiterpenoids synthesis pathway, and five in the methionine cycle pathway. Bioinformatics, genomic structure, and phylogenetic analysis indicated that the JH biosynthesis genes might have experienced evolution after species differentiation. The mRNA tissue distribution analysis revealed that almost all genes involving in or relating to MF syntheses were highly expressed in the mandibular organ (MO), among which juvenile hormone acid methyltransferase was exclusively expressed in the MO, suggesting that most of these genes might mainly function in MF biosynthesis and that the methionine cycle pathway genes might play a crucial regulatory role during MF synthesis. In addition, the phylogenetic and tissue distribution analysis of the cytochrome P450 CYP15-like gene suggested that the epoxidized JHs might exist in crustaceans, but are mainly synthesized in hepatopancreas rather than the MO. Finally, we also found that betaine-homocysteine S-methyltransferase genes were lost in insects while methionine synthase was probably lost in most insects except Folsomia candida, indicating a regulatory discrepancy in the methionine cycle between crustaceans and insects. This study might increase our understanding of synthetic metabolism tailored for sesquiterpenoid hormones in S. paramamosain and other closely related species.
Assuntos
Braquiúros , Ácidos Graxos Insaturados , Animais , Braquiúros/genética , Braquiúros/metabolismo , Ácidos Graxos Insaturados/biossíntese , Metionina/metabolismo , FilogeniaRESUMO
BACKGROUND: The expanded polytetrafluoroethylene (ePTFE)-covered stent has been widely used in the transjugular intrahepatic portosystemic shunt (TIPS) procedure. However, the epidemiologic data of acute TIPS occlusion (ATO) and the underlying mechanisms are scarce. AIMS: The purpose of this study was to evaluate the incidence and prognostic factors for ATO within 1 week in TIPS recipients using ePTFE-covered stents. METHODS: We identified 222 patients who underwent ePTFE-covered TIPS creation for complications of portal hypertension between June 2015 and June 2017 at a large tertiary center. Medical records and TIPS procedure data were retrospectively reviewed, and the influence of these variables on ATO was assessed by multivariate logistic regression analysis. RESULTS: TIPS technical success was achieved in 219 patients (98.6%). Two patients were excluded due to missing data, leaving 217 patients for final analysis. ATO occurred in nine patients (4.1%). Blood flow was restored by balloon angioplasty (n = 4), additional stent insertion (n = 4), and parallel TIPS (n = 1). In multivariable logistic regression, intrastent stenosis (HR 43.871; 95% CI 3.816, 504.373; P = 0.002), previous splenectomy (HR 26.843; 95% CI 2.106, 342.124; P = 0.011), and stent shortening in the hepatic vein (HR 11.54; 95% CI 1.021, 130.416; P = 0.048) were demonstrated as independent significant risk factors for ATO. CONCLUSIONS: These findings suggest that the intrastent stenosis, previous splenectomy, and stent shortening in the hepatic vein are vital prognostic factors for ATO in TIPS recipients. Individualized post-TIPS management strategy was required.
Assuntos
Politetrafluoretileno , Derivação Portossistêmica Transjugular Intra-Hepática/efeitos adversos , Derivação Portossistêmica Transjugular Intra-Hepática/instrumentação , Complicações Pós-Operatórias/epidemiologia , Falha de Prótese , Stents , Adulto , Idoso , Angioplastia com Balão/instrumentação , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/terapia , Desenho de Prótese , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Differences of cytotoxicity associated with exposure to different extracts of atmospheric particulate matters (PMs) are still not well characterized by in vitro toxicoproteomics. In this study, in vitro cytotoxicity assays and toxicoproteomic analyses were carried out to investigate toxic effects of PM collected using polytetrafluoroethylene (PTFE) filters extracted with acetone for PM2.1 and water for PM2.1 and PM10 on A549 human lung epithelial cells. The cytotoxicity assays based on cell viability, cell apoptosis and reactive oxygen species generation indicated that PM2.1 extracted with acetone had the highest toxicity. iTRAQ labeling and LC-MS/MS analyses indicated that the number of differentially expressed proteins in A549 cells affected by PM2.1 extracted with acetone was noticeably higher than that of the other two groups. Hierarchical cluster analyses showed that the influences of the extracts of PM2.1 and PM10 using water on the proteome of A549 cells were similar, whereas significantly different from the effect of PM2.1 extracted with acetone. Pathways analyses indicated that PM2.1 extracted with acetone influenced the expression of proteins involved in 14 pathways including glycolysis/gluconeogenesis, pentose phosphate pathway, proteasome, etc. PM2.1 extracted with water affected the expression of proteins involved in 3 pathways including non-homologous end-joining, ribosome and endocytosis. However, PM10 extracted with water affected the expression of proteins involved in only spliceosome pathway. The extracts of PM using different extractants to detach PM from PTFE filters influenced the cytotoxic effects of PM and the proteome of A549 cells. Therefore, extractants should be assessed carefully before the investigations on cytotoxicity to improve the compatibility of experimental results among research teams.
Assuntos
Poluentes Atmosféricos/toxicidade , Material Particulado/toxicidade , Células A549 , Acetona , Apoptose , Atmosfera/química , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/toxicidade , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Politetrafluoretileno , Proteoma/metabolismo , Proteômica/métodos , ÁguaRESUMO
In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.
Assuntos
Alumínio/química , Membranas Artificiais , Oxigênio/química , Óxido de Zinco/química , Propriedades de Superfície , Difração de Raios XRESUMO
Degradation rate is an important index for evaluating biomaterials. The authors' aim was to determine whether the degradation rate of biomaterials is different in distinct tissues and to clarify the underlying mechanism of degradation. The collagen-chitosan (CG-CS) composite scaffolds were prepared using freeze-drying technology. The porosity, water absorption and swelling ratio of the scaffolds were tested in vitro. The scaffolds were implanted into the subcutis, spinal cord and brain tissues of SD rats, the rate of degradation was assessed by continuous monitoring of weight loss, the pathological changes of target areas were observed by histological staining, and matrix metalloproteinase 9 (MMP-9) and lysozyme were detected at the rapid stage of degradation of the scaffolds. Physical and chemical property testing confirmed that CG-CS composite scaffold components can meet the biological requirements of in vivo transplantation. The in vivo experimental results showed that the scaffolds were completely absorbed in the subcutis at 12 days, the scaffolds in the spinal cord and brain groups exhibited progressive mass loss starting from the 3rd week, and a substantial fraction of the scaffold was degraded at 12 weeks. HE staining found that compared with the spinal cord and brain groups, macrophages and capillaries appeared earlier in the subcutis group, and the number was significantly higher (P < 0.05). Western blot analysis showed that the MMP-9 and lysozyme levels in the subcutis were higher than those in the spinal cord and brain (P < 0.05). The results of in vivo experiments demonstrated that the CG-CS scaffold has good biocompatibility and biodegradability, while the rate of degradation was significantly different between the three tissues at the same time point. Macrophage behavior and vascularization in different parts of the body may result in control over the balance of degradation and reconstruction.
Assuntos
Encéfalo/metabolismo , Quitosana/química , Colágeno/química , Medula Espinal/metabolismo , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis , Microscopia Eletrônica de Varredura , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual/métodosRESUMO
The clathrin-mediated endocytosis is likely a major mechanism of liposomes' internalization. A kinetic approach was used to assess the internalization mechanism of doxorubicin (Dox) loaded cationic liposomes and to establish physiology-based cell membrane traffic mathematic models. Lipid rafts-mediated endocytosis, including dynamin-dependent or -independent endocytosis of noncaveolar structure, was a dominant process. The mathematic models divided Dox loaded liposomes binding lipid rafts (B) into saturable binding (SB) and nonsaturable binding (NSB) followed by energy-driven endocytosis. The intracellular trafficking demonstrated early endosome-late endosome-lysosome or early/late endosome-cytoplasm-nucleus pathways. The three properties of liposome structures, i.e., cationic lipid, fusogenic lipid, and pegylation, were investigated to compare their contributions to cell membrane and intracellular traffic. The results revealed great contribution of cationic lipid DOTAP and fusogenic lipid DOPE to cell membrane binding and internalization. The valid Dox in the nuclei of HepG2 and A375 cells treated with cationic liposomes containing 40mol% of DOPE were 1.2-fold and 1.5-fold higher than that in the nuclei of HepG2 and A375 cells treated with liposomes containing 20mol% of DOPE, respectively, suggesting the dependence of cell type. This tendency was proportional to the increase of cell-associated total liposomal Dox. The mathematic models would be useful to predict intracellular trafficking of liposomal Dox.
Assuntos
Doxorrubicina/análogos & derivados , Endocitose/fisiologia , Microdomínios da Membrana/fisiologia , Modelos Biológicos , Transporte Biológico , Cátions , Linhagem Celular , Doxorrubicina/administração & dosagem , Doxorrubicina/metabolismo , Ácidos Graxos Monoinsaturados/química , Células Hep G2 , Humanos , Lipossomos , Fusão de Membrana , Lipídeos de Membrana/química , Microscopia de Fluorescência , Fosfatidiletanolaminas/química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/metabolismo , Compostos de Amônio Quaternário/químicaRESUMO
The damage caused by fluorosis is permanent, and has been recognized as a public health problem in a number of regions of the world. Although multiple studies provided evidence that sodium fluoride (NaF) elicits adverse effects on reproductive function, the effect of fluoride on female germ cell development is not well understood. Therefore, the present study aimed at evaluating the effect of fluoride treatments on in vivo maturation and developmental potential of mouse oocytes, in which female ICR mice were treated with a range of doses (0, 30, 60, and 150 mg/L) of NaF. After treatment, mice were superovulated to collect ovulated oocytes. The effects of NaF on oocyte quality, fertilization potential and early embryonic development were evaluated, as well as the underlying mechanisms were primarily investigated. The findings of this study showed that NaF treatment resulted in abnormal spindle configuration, actin cap formation, and cortical granule-free domain formation. Additionally, overexposure of mice to NaF notably reduced ATP production and mitochondrial membrane potential, further influencing in vitro fertilization and subsequent embryonic development. These results indicated that NaF treatment impairs the subsequent embryonic developmental potential of the oocytes. In conclusion, overexposure to fluoride in vivo was associated with a significant disruption of cytoskeletal dynamics and decreased oocyte quality, affecting the oocyte's subsequent fertilization and embryonic development. Results of this study provide a rationale for treating reproductive diseases such as infertility or miscarriage caused by environmental contaminants. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1486-1495, 2016.
Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Oócitos/efeitos dos fármacos , Oogênese/efeitos dos fármacos , Fluoreto de Sódio/toxicidade , Animais , Células Cultivadas , Feminino , Fertilização/efeitos dos fármacos , Fertilização in vitro , Técnicas de Maturação in Vitro de Oócitos , Masculino , Camundongos , Camundongos Endogâmicos ICR , GravidezRESUMO
PURPOSE: Percutaneous vertebroplasty (PVP) is a common procedure in spine surgery. Bone cement leakage is the most common complication related to this procedure. The purpose of this study was to assess the incidence and risk factors for cement leakage after PVP. METHODS: A total of 485 patients who underwent PVP between August 2003 and August 2013 were enrolled in the study. Clinical and radiological characteristics, including age, gender, diagnosis, operated level, surgical approach, type of anesthesia, volume of bone cement, fracture type, and fracture severity, were considered as potential risk factors. Cement leakage was assessed based on post-operative imaging examination. Six types of leakage were defined and risk factors for each type were analyzed. RESULTS: The incidence of leakage was 58.2 %. Binary logistic analysis revealed that larger volume of bone cement (P < 0.001) and higher fracture severity grade (P < 0.001) were the strongest independent risk factors. Univariate analysis and multinomial logistic analysis showed that surgical approach (P < 0.001), gender (P = 0.016), and operated level (P = 0.032) were additional risk factors for leakage. Further analysis showed that more bone cement was used in bilateral than unilateral approaches, that men had larger volumes of bone cement injected than women, and that more bone cement was injected into lumbar vertebrae than thoracic vertebrae. Therefore, these risk factors (surgical approach, gender, and operated level) could be attributed to excess bone cement usage. CONCLUSIONS: Cement leakage is very common with PVP. Higher fracture severity grade and larger volume of bone cement were the two strongest independent risk factors for leakage.
Assuntos
Cimentos Ósseos/efeitos adversos , Coluna Vertebral/cirurgia , Vertebroplastia/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Coluna Vertebral/patologia , Vertebroplastia/métodosRESUMO
3-Hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductases (HMGRs), which catalyze the conversion of HMG-CoA to mevalonate, may have an important role in the synthesis of methyl farnesoate (MF). In this study, we obtained two HMGR cDNA sequences termed Sp-HMGR1 (membrane-bound form) and Sp-HMGR2 (soluble form), which encode 967 and 654 amino acids, respectively. The two cDNAs possess entirely identical sequences except that Sp-HMGR1 is 1,382 bp, which encodes a sterol-sensed domain (SSD; a membrane-bound domain) and was first found in crustacean HMGR, larger than Sp-HMGR2. Thus, it was deduced that these cDNAs might be derived from a single genomic DNA sequence. Sp-HMGRs have the typical features of the HMGR class of proteins. However, residue 844 in Sp-HMGR1, which is usually occupied by a Ser residue in other species, has an unusual Ala substitution. This Ser is thought to be involved in enzyme activity regulation by reversible phosphorylation. A putative "PEST" sequence that, until now, has only been found in crustacean species was also identified in the C-terminus of both transcripts, and a sterol-sensing domain, which was first found in crustacean species, was identified in Sp-HMGR1; these findings suggest that Sp-HMGR might function in some special regulatory mechanism. Furthermore, the quantitative real-time polymerase chain reaction results showed that the two transcripts have different expression patterns; Sp-HMGR2 was mainly expressed in the mandibular organ (MO) of adult crabs, whereas Sp-HMGR1 was mainly expressed in other tissues and fertilized eggs up until the fourth juvenile crab stage. The fluctuating gene expression seemed to suggest a relationship between Sp-HMGRs and the development of the crab, especially during the larval stage. Besides, the fluctuation of Sp-HMGR1 in ovary, brain, and thoracic ganglia during the ovary development seemed to have some correlation with the nutrition accumulation of ovaries, whether the SSD domain evolved in this process deserve further investigation. Moreover, it remains unclear whether the significant variation in ovary, brain, and thoracic ganglia during ovary development suggests that other tissues in addition to the MO could synthesize MF.
Assuntos
Proteínas de Artrópodes/genética , Braquiúros/crescimento & desenvolvimento , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , Animais , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Braquiúros/genética , Clonagem Molecular , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Isoenzimas/genética , Isoenzimas/metabolismo , Dados de Sequência Molecular , Ovário/crescimento & desenvolvimento , Filogenia , Homologia de Sequência de AminoácidosRESUMO
The colonization ability of bacteria on biomaterial surfaces is influenced by the morphology of the bacteria and the nanotopography of the biomaterial. However, interactions between the bacterial morphology and nanotopography of biomaterials have not yet been completely elucidated. In this article, we quantitatively characterized the bacterial morphology to illuminate the integrated effects of polyethylene terephthalate (PET) nanopillar arrays on the colonization of bacteria cells with different shapes. Our results demonstrated that the interaction between interpillar spacing and the diameter of the bacterial cells impacted the number of bacterial cells that adhered to different PET substrates. The interpillar spacing of nanopillar arrays promotes bacterial adhesion in a definite range (<50 nm). However, further increasing the interpillar spacing inhibited the adhesion of bacteria to the nanopillar arrays. Moreover, the interpillar spacing also influenced the morphologies of adherent bacterial cells on the PET nanopillar arrays, which consequently facilitated bacterial adhesion to the nanopillar arrays. Our findings enhance the understanding of interactions between controlled nanotopography and bacterial colonization and provide an appropriate parameter for the design of antibacterial materials with nanotopography.
Assuntos
Aderência Bacteriana , Nanoestruturas/química , Polietilenotereftalatos/química , Bactérias/crescimento & desenvolvimento , Bactérias/ultraestrutura , Teste de MateriaisRESUMO
Glycosylation plays an important role in protein conformations and functions as well as many biological activities. Capillary electrophoresis combined with various detection methods provided remarkable developments for high-sensitivity glycan profiling. The coating of the capillary is needed for highly polar molecules from complex biosamples. A poly(vinyl alcohol)-coated capillary is commonly utilized in the capillary electrophoresis separation of saccharides sample due to the high-hydrophilicity properties. A modified facile coating workflow was carried out to acquire a novel multiple-layer poly(vinyl alcohol)-coated capillary for highly sensitive and stable analysis of glycans. The migration time fluctuation was used as index in the optimization of layers and a double layer was finally chosen, considering both the effects and simplicity in fabrication. With migration time relative standard deviation less than 1% and theoretical plates kept stable during 100 consecutive separations, the method was presented to be suitable for the analysis of glycosylation with wide linear dynamic range and good reproducibility. The glycan profiling of enzymatically released N-glycans from human serum was obtained by the presented capillary electrophoresis method combined with mass spectrometry detection with acceptable results.
Assuntos
Polissacarídeos/sangue , Álcool de Polivinil/química , Eletroforese Capilar , Humanos , Espectrometria de MassasRESUMO
The effects of fluoride exposure on the functions of reproductive and endocrine systems have attracted widespread attention in academic circle nowadays. However, it is unclear whether the gene-environment interaction may modify the secretion and activity of hypothalamus-pituitary- ovarian (HPO) axis hormones. Thus, the aim of this study was to explore the influence of fluoride exposure and follicle stimulating hormone receptor (FSHR) gene polymorphism on reproductive hormones in Chinese women. A cross sectional study was conducted in seven villages of Henan Province, China during 2010-2011. A total of 679 women aged 18-48 years were recruited through cluster sampling and divided into three groups, i.e. endemic fluorosis group (EFG), defluoridation project group (DFPG), and control group (CG) based on the local fluoride concentration in drinking water. The serum levels of gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were determined respectively and the FSHR polymorphism was detected by real time PCR assay. The results provided the preliminary evidence indicating the gene-environment interaction on HPO axis hormones in women.
Assuntos
Fluoretos/efeitos adversos , Receptores do FSH/genética , Adolescente , Adulto , Fatores Etários , Povo Asiático , China , Estudos Transversais , Estradiol/sangue , Feminino , Fluoretação/efeitos adversos , Fluoretos/administração & dosagem , Fluoretos/urina , Hormônio Foliculoestimulante/sangue , Interação Gene-Ambiente , Hormônio Liberador de Gonadotropina/sangue , Humanos , Hipotálamo/fisiologia , Hormônio Luteinizante/sangue , Pessoa de Meia-Idade , Ovário/fisiologia , Hipófise/fisiologia , Polimorfismo de Nucleotídeo Único , Poluição por Fumaça de Tabaco , Adulto JovemRESUMO
Our goal was to introduce the application of submental island flap in reconstructing through-and-through cheek defects. From January 2009 to January 2013, 7 patients (5 men and 2 women) with full-thickness buccal defects due to tumor resection received submental flap reconstruction at the Affiliated Tumor Hospital of Zhengzhou University; surgical procedure and success rate as well as functional results were described. Distal partial necrosis occurred in 1 flap, but all flaps survived. All patients were capable of maintaining a regular oral diet, and no patients complained of an inability to eat in a public setting, microstomia, or drooling; the appearance was reported to be good or acceptable in all cases, and the mean postoperative mouth-open width was 4.2 (range, 3.7-5.0) cm. One patient had a local recurrence in the follow-up. Therefore, submental island flap is a reliable procedure for through-and-through buccal defects in selected patients.
Assuntos
Carcinoma de Células Escamosas/cirurgia , Bochecha/cirurgia , Neoplasias de Cabeça e Pescoço/cirurgia , Procedimentos Cirúrgicos Bucais/métodos , Procedimentos de Cirurgia Plástica/métodos , Retalhos Cirúrgicos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
Enrichment of microbial consortia provides an approach to simulate and investigate microbial communities in natural environments. In this study, a cellulolytic microbial consortium SQD-1.1 was enriched from mangrove soil of Qinglan port (Hainan, China) by 27 times continuous subcultivation under anaerobic static conditions. The consortium could completely degrade 0.2% (w/v) filter paper within 3 days and utilized it as the sole carbon source. PCR-denaturing gradient gel electrophoresis analysis revealed a stable microbial community structure in the incubation process of 10 days and in the procedure of subcultivation. Twenty-four operational taxonomic units belonging to seven phyla were obtained from the full-length 16S rRNA gene library. Five clones, closest related to the genera Alkaliflexus, Clostridium, Alistipes, Spirochaeta, and Trichococcus, were the predominant ones. Among them, M117, phylogeneticly showing high similarity (16S rRNA gene identity, 95.3%) with the cellulolytic anaerobic bacterium Clostridium straminisolvens CSK1(T), was the potential key cellulolytic bacterium. Using the plate cultivation method, 12 strains, including one potential new species and four potential new species of new genera, were isolated. The strain P2, corresponding to the most frequently detected clone (M05) in the 16S rRNA gene library, showed both CMCase and xylanase activity and may be another important cellulolytic bacterium. The findings of cellulase activity in cell pellet and cohesion and dockerin domains in metagenome data further suggested the potential of utilization of cellulosomes by the consortium to degrade cellulose. Consortium SQD-1.1 provides a candidate for investigating the mechanism of cellulose degradation under anoxic conditions in natural environments.
Assuntos
Celulose/metabolismo , Consórcios Microbianos , Microbiologia do Solo , Anaerobiose , China , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Gradiente Desnaturante , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico 16S , Análise de Sequência de DNARESUMO
Traditional chitosan hydrogels were prepared by chemical or physical crosslinker, and both of the two kinds of hydrogels have their merits and demerits. In this study, researchers attempted to prepare one kind of chitosan hydrogel by slightly crosslinker, which could combine the advantages of the two kinds of hydrogels. In this experiment, the crosslinker was formed by a reaction between the isocyanate group of 1,6-diisocyanatohexan and the hydroxyl group of polyethylene glycol-400 (PEG-400), then the crosslinker reacted with the amidine and the hydroxyl group of ethylene glycol chitosan to form the network structure. Physical properties of the hydrogel were tested by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and biodegradation. Biocompatibility was assessed by cell implantation in vitro and the scaffold was used as a cartilage tissue engineering scaffold to repair a defect in rabbit knee joints in vivo. FTIR results show the formation of a covalent bond during thickening of the ethylene glycol chitosan. SEM and degradation experiments showed that the ethylene glycol chitosan hydrogel is a 3-D, porous, and degradable scaffold. The hydrogel contained 2% ethylene glycol chitosan and 10 µl crosslinker was selected for the biocompatibility experiment in vitro and in vivo. After chondrocytes were cultured in the ethylene glycol chitosan hydrogel scaffold for 1 week cells exhibited clustered growth and had generated extracellular matrix on the scaffold in vitro. The results in vivo showed that hydrogel-chondrocytes promoted the repair of defect in rabbits. Based on these results, it could be concluded that ethylene glycol chitosan hydrogel is a scaffold with excellent physicochemical properties and it is a promising tissue engineering scaffold.
Assuntos
Quitosana/química , Hidrogéis , Isocianatos/química , Polietilenoglicóis/química , Engenharia Tecidual , Alicerces Teciduais , Animais , Células Cultivadas , Condrócitos/metabolismo , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Coelhos , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
In the domain of medical diagnostics, precise identification of various skin and oral diseases is vital for effective patient care. In particular, Mpox is a potentially dangerous viral disease with zoonotic origins, capable of human-to-human transmission, underscoring the urgency of precise diagnostic methods for timely intervention. This paper introduces a novel approach named the Choquet Fuzzy Integral-based Ensemble (CFI-Net) for accurate classification of skin diseases, with a specific emphasis on detecting Mpox, foot ulcers, and various mouth and oral diseases. Our methodology begins with Transfer Learning, enhancing the classification capabilities of base classifiers (DenseNet169, MobileNetV1 and DenseNet201) by incorporating additional layers. Subsequently, we aggregate the prediction scores from each base classifier using the Choquet fuzzy integral (CFI) to derive the final predicted labels, thus ensuring dynamic and robust predictions. Fuzzy measures, a crucial component of this fuzzy integral-based ensemble method, are typically determined through manual experimentation in previous approaches. However, in our study, we have tackled the challenge of manual tuning by employing meta-heuristic optimization algorithm to precisely configure the fuzzy measures for optimal performance. A rigorous evaluation is conducted on four publicly available datasets, encompassing two Mpox datasets, a foot ulcer dataset, and a mouth and oral disease dataset. The experiments reveal the remarkable effectiveness of CFI-Net in significantly improving disease classification accuracy. Additionally, we employ Grad-CAM analysis to provide insights into the decision-making processes of our models. Our findings underscore the exceptional performance of CFI-Net, achieving accuracy rates of 98.06% and 94.81% for Mpox detection, 99.06% for foot ulcer detection, and an impressive 99.61% for mouth and oral disease classification. This research not only contributes to the advancement of disease diagnosis but also demonstrates the effectiveness of ensemble learning techniques coupled with fuzzy integral-based fusion in enhancing diagnostic accuracy.
RESUMO
Medium-entropy alloys (MEAs) typically exhibit outstanding mechanical properties, but their high Young's modulus results in restricted clinical applications. Mismatched Young's modulus between implant materials and human bones can lead to "stress shielding" effects, leading to implant failure. In contrast, ß-Ti alloys demonstrate a lower Young's modulus compared to MEAs, albeit with lower strength. In the present study, based on the bimodal grain size distribution (BGSD) strategy, a series of high-performance TiZrNbTa/Ti composites are obtained by combining TiZrNbTa MEA powders with nano-scale grain sizes and commercially pure Ti (CP-Ti) powders with micro-scale grain sizes. Concurrently, Zr, Nb, and Ta that are ß-Ti stabilizer elements diffuse into Ti, inducing an isomorphous transformation in Ti from the high Young's modulus α-Ti phase to the low Young's modulus ß-Ti phase at room temperature, optimizing the mechanical biocompatibility. The TiZrNbTa/ß-Ti composite demonstrates a yield strength of 1490 ± 83 MPa, ductility of 20.7 % ± 2.9 %, and Young's modulus of 87.6 ± 1.6 GPa. Notably, the yield strength of the TiZrNbTa/ß-Ti composite surpasses that of sintered CP-Ti by 2.6-fold, and its ductility outperforms TiZrNbTa MEA by 2.3-fold. The Young's modulus of the TiZrNbTa/ß-Ti composite is reduced by 28 % and 36 % compared to sintered CP-Ti and TiZrNbTa MEA, respectively. Additionally, it demonstrates superior biocompatibility compared to CP-Ti plate, sintered CP-Ti, and TiZrNbTa MEA. With a good combination of mechanical properties and biocompatibility, the TiZrNbTa/ß-Ti composite exhibits significant potential for clinical applications as metallic biomaterials. STATEMENT OF SIGNIFICANCE: This work combines TiZrNbTa MEA with nano-grains and commercially pure Ti with micro-grains to fabricate a TiZrNbTa/ß-Ti composite with bimodal grain-size, which achieves a yield strength of 1490 ± 83 MPa and a ductility of 20.7 % ± 2.9 %. Adhering to the ISO 10993-5 standard, the TiZrNbTa/ß-Ti composite qualifies as a non-cytotoxic material, achieving a Class 0 cytotoxicity rating and demonstrating outstanding biocompatibility akin to commercially pure Ti. Drawing on element diffusion, Zr, Nb, and Ta serve not only as solvent atoms to achieve solid-solution strengthening but also as stabilizers for the transformation of the ß-Ti crystal structure. This work offers a novel avenue for designing advanced biomedical Ti alloys with elevated strength and plasticity alongside a reduced Young's modulus.
Assuntos
Ligas , Materiais Biocompatíveis , Teste de Materiais , Titânio , Titânio/química , Titânio/farmacologia , Ligas/química , Ligas/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Animais , Módulo de Elasticidade , Humanos , Nióbio/química , Nióbio/farmacologia , Zircônio/química , Zircônio/farmacologia , Transição de Fase , CamundongosRESUMO
Vaccines represent one of the most powerful and cost-effective innovations for controlling a wide range of infectious diseases caused by various viruses and bacteria. Unlike mRNA and DNA-based vaccines, subunit vaccines carry no risk of insertional mutagenesis and can be lyophilized for convenient transportation and long-term storage. However, existing adjuvants are often associated with toxic effect and reactogenicity, necessitating expanding the repertoire of adjuvants with better biocompatibility, for instance, designing self-adjuvating polymeric carriers. We herein report a novel subunit vaccine delivery platform constructed via in situ free radical polymerization of C7A (2-(Hexamethyleneimino) ethyl methacrylate) and acrylamide around the surface of individual protein antigens. Using ovalbumin (OVA) as a model antigen, we observed substantial increases in both diameter (â¼70 nm) and surface potential (-1.18 mV) following encapsulation, referred to as n(OVA)C7A. C7A's ultra pH sensitivity with a transition pH around 6.9 allows for rapid protonation in acidic environments. This property facilitates crucial processes such as endosomal escape and major histocompatibility complex (MHC)-I-mediated antigen presentation, culminating in the substantial CD8+ T cell activation. Additionally, compared to OVA nanocapsules without the C7A components and native OVA without modifications, we observed heightened B cell activation within the germinal center, along with remarkable increases in serum antibody and cytokine production. It's important to note that mounting evidence suggests that adjuvant effects, particularly its targeted stimulation of type I interferons (IFNs), can contribute to advantageous adaptive immune responses. Beyond its exceptional potency, the nanovaccine also demonstrated robust formation of immune memory and exhibited a favorable biosafety profile. These findings collectively underscore the promising potential of our nanovaccine in the realm of immunotherapy and vaccine development.
Assuntos
Camundongos Endogâmicos C57BL , Ovalbumina , Linfócitos T Citotóxicos , Animais , Ovalbumina/imunologia , Ovalbumina/administração & dosagem , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Adjuvantes Imunológicos/química , Feminino , Metacrilatos/química , Polímeros/química , Polímeros/administração & dosagem , Nanopartículas/química , Nanopartículas/administração & dosagem , Camundongos , Vacinas/administração & dosagem , Vacinas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , NanovacinasRESUMO
A novel pH-responsive coating technique was developed and applied to CE successfully in this paper. The coating was formed by bonding mixed opposite charge poly(acrylic acid) and poly(2-vinylpyridine) randomly onto the inner wall of a silica capillary. The coating processes were first characterized by ellipsometry and atomic force microscopy at macroscale and microscale, respectively. Measurements of EOF were implemented to confirm the coating. Direction and velocity of EOF became controllable from negative to positive, showing a perfect sigmoidal curve as the coating net charges alternated by the pH of BGE. The control of the EOF makes it possible to analyze different kinds of small molecules, peptides, and proteins successfully in the same capillary. Results showed that the stability and reproducibility for separations of fluoroquinolone standards were satisfactory for more than a hundred separations. A series of basic and acidic protein standards were separated with admirable efficiency and minimal adsorption using both polarities. The separation of tryptic BSA digest showed that the prepared capillary has immense potential in analyzing a single sample with both acidic and basic separations, which achieved the expectation in proteomics study by CE-MS.