RESUMO
To ensure the structural integrity of concrete and prevent unanticipated fracturing, real-time monitoring of early-age concrete's strength development is essential, mainly through advanced techniques such as nano-enhanced sensors. The piezoelectric-based electro-mechanical impedance (EMI) method with nano-enhanced sensors is emerging as a practical solution for such monitoring requirements. This study presents a strength estimation method based on Non-Destructive Testing (NDT) Techniques and Long Short-Term Memory (LSTM) and artificial neural networks (ANNs) as hybrid (NDT-LSTMs-ANN), including several types of concrete strength-related agents. Input data includes water-to-cement rate, temperature, curing time, and maturity based on interior temperature, allowing experimentally monitoring the development of concrete strength from the early steps of hydration and casting to the last stages of hardening 28 days after the casting. The study investigated the impact of various factors on concrete strength development, utilizing a cutting-edge approach that combines traditional models with nano-enhanced piezoelectric sensors and NDT-LSTMs-ANN enhanced with nanotechnology. The results demonstrate that the hybrid provides highly accurate concrete strength estimation for construction safety and efficiency. Adopting the piezoelectric-based EMI technique with these advanced sensors offers a viable and effective monitoring solution, presenting a significant leap forward for the construction industry's structural health monitoring practices.
Assuntos
Materiais de Construção , Impedância Elétrica , Aprendizado de Máquina , Redes Neurais de Computação , Materiais de Construção/análise , Nanotecnologia/instrumentação , Nanotecnologia/métodos , Teste de Materiais/métodosRESUMO
This study investigates digestibility enhancements of lignocellulose from shock pretreatment, alkaline pretreatment, and combination. Shock pretreatment subjects aqueous slurries of lignocellulose to shock waves, which disrupts its structure rendering it more susceptible to hydrolysis. Alkaline pretreatment submerges the biomass in aqueous alkali (NaOH, Ca(OH)2 ), which removes lignin and acetyl groups. As indicators of digestibility, cellulase (CTec3) and hemicellulase (HTec3) were used to saccharify the pretreated corn stover and the resulting filtrate which contains about 10% of the sugars. Shock is most effective when it precedes alkaline pretreatment, presumably because it opens the biomass structure and enhances diffusion of pretreatment chemicals. Lignocellulose digestibility from calcium hydroxide treatment improves significantly with oxygen addition. In contrast, sodium hydroxide is a more potent alkali, and thereby eliminates the need for oxygen to enhance pretreatment. At low hydroxide loadings (<4 g OH- /100 g dry biomass), both NaOH and Ca(OH)2 provide similar increases in digestibility; however, at high hydroxide loadings, NaOH is superior. For animal feed, Ca(OH)2 treatment is recommended, because residual calcium ions are valuable nutrients. In contrast, for methane-arrested anaerobic digestion, NaOH treatment is preferred because NaHCO3 is a stronger buffer. At 50°C, shock pretreatment improves sugar yields at all NaOH loadings. The effect of shock is most pronounced when the no-shock control employed the same soaking-and-drying procedure as the shock treatment. The recommended conditions are shock treatment (5.52 bar [abs] initial H2 /O2 pressure) followed by 50°C alkaline treatment with NaOH loading of 4 g OH- /100 g dry biomass for 1 h.
Assuntos
Álcalis , Zea mays , Álcalis/química , Biomassa , Humanos , Hidrólise , Lignina/química , Oxigênio , Hidróxido de Sódio/química , Zea mays/químicaRESUMO
Corn stover, an underutilized agricultural residue, is a promising lignocellulosic feedstock for producing biofuels. To fully utilize it, pretreatment is needed. Typically, pretreatments are rapidly assessed using extracellular enzymes that release sugars from cellulose and hemicellulose. In contrast, this study uses methane-arrested anaerobic digestion (MAAD) to assess pretreatments. Although time consuming, MAAD is a more accurate assessment technique when lignocellulose is employed in the carboxylate platform, a promising approach that utilizes nearly all biomass components. Using recommended pretreatment conditions identified from a previous study, three corn stover pretreatments were compared using MAAD: (1) shock-only, (2) NaOH-only, and (3) shock + NaOH. Air-dried sewage sludge was used as nutrient source. At 100 g/L initial substrate concentration, compared to untreated corn stover, shock-only decreased conversion (amount of biomass digested) by 14%, NaOH-only increased conversion by 82%, and shock + NaOH increased conversion by 104%. Using batch MAAD data, the continuum particle distribution model simulated four-stage countercurrent fermentation. At an industrial non-acid volatile solids (NAVS) concentration of 300 g/Lliq , for both NaOH-only and shock + NaOH, the model predicts total carboxylic acid concentration of about 58 g/L and conversion of about 0.85 g NAVSdigested /g NAVSfed at liquid retention time of 35 days and volatile solid loading rate of 4 g/(Lliq â day). At this long solid residence time, shock is not necessary; however, with short solid residence times, shock acts synergistically to aid NaOH pretreatment. Shock treatment offers a way to reduce pretreatment costs without sacrificing pretreatment efficacy.
Assuntos
Metano , Zea mays , Álcalis/química , Anaerobiose , Biocombustíveis , Esgotos , Hidróxido de Sódio/química , Zea mays/químicaRESUMO
Hepatic osteodystrophy (HOD) is a metabolic bone disease that is often associated with chronic liver disease and is marked by bone loss. Here, we demonstrate that hepatic expression of the phosphatase PP2Acα is upregulated during HOD, leading to the downregulation of expression of the hepatokine lecithin-cholesterol acyltransferase (LCAT). Loss of LCAT function markedly exacerbates the bone loss phenotype of HOD in mice. In addition, we found that alterations in cholesterol levels are involved in the regulation of osteoblast and osteoclast activities. We also found that LCAT improves liver function and relieves liver fibrosis in the mouse HOD model by promoting reversal of cholesterol transport from the bone to the liver. In summary, defects in a liver-bone axis occur during HOD that can be targeted to ameliorate disease progression.
Assuntos
Doenças Ósseas Metabólicas , Cirrose Hepática , Animais , Doenças Ósseas Metabólicas/metabolismo , Doenças Ósseas Metabólicas/patologia , Colesterol/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Fígado/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Camundongos , Fosfatidilcolina-Esterol O-Aciltransferase/genética , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismoRESUMO
Hepatic stellate cells (HSCs) play a critical role in the pathogenesis and reversal of liver fibrosis. Targeting HSCs is of great significance in the treatment of hepatic fibrosis, and has attracted wide attention of scholars. Here we demonstrated that expression of geranylgeranyldiphosphate synthase (GGPPS) predominantly increased in HSCs in murine fibrotic liver. HSC-specific knockdown of GGPPS using vitamin A-coupled liposome carrying siRNA-ggpps decreased activation of HSCs and alleviated fiber accumulation in vivo. Furthermore, our in vitro studies showed that GGPPS was up-regulated during HSCs activation in TGF-ß1-dependent manner. Inhibition of GGPPS suppressed TGF-ß1 induced F-actin reorganization and HSCs activation in LX-2 cells. Further, we found that GGPPS regulated HSCs activation and liver fibrosis possibly by enhancing RhoA/Rock kinase signaling. So its concluded that GGPPS promotes liver fibrosis by activating HSCs, which may represent a potential target for anti-fibrosis therapies.
RESUMO
BACKGROUND: This study is to investigate the effect of Egr1 on the mineralization and accumulation of chondrocyte extracellular matrix. METHODS: The femoral heads of patients of various heights were collected. Egr1 knockout mice were used. Their limb lengtha nd body weight were assessed. The bone characteristics were detected by micro-CT scan and histological staining. Immature murine articular chondrocytes (iMACs) were isolated. Gross morphology was observed by histological staining. Relevant mRNA and protein expression were detected by qRT-PCR and Western blot, respectively. the related proteins were observed by immunohistochemical staining and immunofluorescence assay. Chromatin immunoprecipitation and reporter gene assay were also used. TUNEL was used to detect apoptosis. RESULTS: It was found that shorter patients had reduced Egr1 expression levels in the hypertrophic cartilage zone of the femoral head. In addition, Egr1 knockout mice exhibited reduced body size. Micro-CT analysis showed that these mice also had reduced bone volume. Safranin-O staining showed that the extracellular matrix of these mice exhibited a relatively limited degree of mineralization, and TUNEL staining showed reduced cell apoptosis levels. After transfecting the iMACs with dominant-negative Egr1 adenoviruses to inhibit Egr1, the enzymes of Adamst4, Adamst5, Mmp3 and Mmp13 were significantly upregulated. ChIP and luciferase assays revealed that Egr1 might regulate the chondrocyte extracellular matrix by the PPARγ/RUNX2 signaling pathways. CONCLUSION: Egr1 has an important regulatory effect on the dynamic equilibrium of the chondrocyte extracellular matrix, which may be achieved through the PPARγ/RUNX2 signaling pathways.
RESUMO
BACKGROUND AND PURPOSE: Enterobacter spp. have emerged as an important cause of nosocomial bacteremia. The purpose of this study was to delineate the clinical, laboratory and microbiologic features that may influence prognosis of Enterobacter cloacae and enable a stratification of those patients at high risk of mortality. METHODS: This retrospective study reviewed 108 episodes of E. cloacae bacteremia occurring over a 2-year period (November 2001 to October 2003) at Taipei Veterans General Hospital. Univariate analysis were performed to demonstrate the relation of possible risk factors to death attributable to E. cloacae bacteremia. RESULTS: Ninety-three episodes (86.1%) were hospital-acquired. The most common portal of entry was the genitourinary tract (17.9%) followed by the gastrointestinal tract (15.1%). Underlying diseases associated with E. cloacae bacteremia were neoplastic diseases (42 episodes, 38.9%), diabetes mellitus (20 episodes, 18.5%) and chronic renal failure (18 episodes, 16.7%). The overall mortality rate was 42.6%, and E. cloacae bacteremia-attributable mortality occurred in 22 patients (20.9%). Factors significantly correlated with death attributable to bacteremia were older age, a higher medium number of underlying diseases, hemoglobin <10 g/dL, serum C-reactive protein >10 mg/dL, hypoalbuminemia, disseminated intravascular coagulation, septic shock, respiratory failure, renal failure (creatinine >2 mg/dL) and delayed clinical response after initiation of antibiotic therapy. CONCLUSIONS: Antibiotic-resistant isolates and appropriate empirical antibiotic use were not independent predictors of mortality in this study. The condition of patients at onset of symptoms and presence of underlying diseases appear to be important predictors mortality from E. cloacae bacteremia.
Assuntos
Bacteriemia/mortalidade , Infecções por Enterobacteriaceae/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Bacteriemia/complicações , Bacteriemia/microbiologia , Sangue/microbiologia , Criança , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Meios de Cultura , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/isolamento & purificação , Infecções por Enterobacteriaceae/complicações , Infecções por Enterobacteriaceae/microbiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prognóstico , Fatores de RiscoRESUMO
AIM: To study the sensitizing effect of acemetacin (ACE) on the weak chemiluminescent (CL) reaction of KMnO4 with sulfite and establish a fast and convenient method for CL detection of ACE. METHODS: Using the sensitizing effect of ACE on KMnO4-Na2SO3 system and flow injection technique to determine the concentration of ACE. RESULTS: Under optimal conditions, the CL intensity of 1.0 x 10(-2) mol x L(-1) H3PO4 - 5.0 x 10(-5) mol x L(-1) KMnO4 - 4.0 x 10(-4) mol x L(-1) Na2SO3 was proportional to the concentration of ACE ranging from 1.0 x 10(-7) to 1.0 x 10(-5) mol x L(-1). The detection limit of ACE was 6.9 x 10(-8) mol x L(-1) at 3sigma. Satisfactory results were obtained for determination of ACE at 2.5 x 10(-6) mol x L(-1). CONCLUSION: The present method showed good precision, high sensitivity and selectivity and could be used for fast and convenient detection of ACE. It would be of significance to the clinical and pharmacological study of acemetacin.
Assuntos
Análise de Injeção de Fluxo/métodos , Indometacina/análogos & derivados , Indometacina/análise , Medições Luminescentes/métodos , Permanganato de Potássio/química , Sulfitos/químicaRESUMO
The involvement of ERK signals in gastric carcinoma was investigated using Western blot, MTT, and flow cytometric analysis in cultured cells SGC7901. Results showed that treatment of sorafenib potently inhibited gastric SGC7901 cells proliferation, migration, invasion as well as promoted apoptosis. Treatment of sorafenib significantly decreased phosphorylation activation of ERK protein in a dose-dependent manner. Treatment of sorafenib still significantly increased caspase-3, bax, cyt-c protein expression and decreased bcl-2 protein in a dose-dependent manner. Our study confirms that ERK signals pathway is closely associated with development of gastric cancer. Deactivation of phosphorylation of ERK protein is one of the mechanisms of sorafenib inhibiting gastric cancer.
Assuntos
Antineoplásicos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Microcystis/metabolismo , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Apoptose , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Niacinamida/farmacologia , Fosforilação/efeitos dos fármacos , Sorafenibe , Neoplasias Gástricas/genéticaRESUMO
The UHRF1 gene plays important roles in both cell proliferation through its NIRF_N domains, a PHD domain, an SRA domain, and a RING domain, and multidrug resistance in breast cancer treatment. In this work, a short-hairpin RNA (shRNA) lentiviral system was introduced in two human breast cancer cell lines (MDA-MB-231 and MCF-7) to downregulate the expression of UHRF1 and study the specific inhibition of UHRF1 in breast cancer growth. The effect of UHRF1-shRNA on breast cancer cell proliferation was examined using methylthiazoletetrazolium, bromodeoxyuridine, and colony formation assays. The proliferative potential of the UHRF1-shRNA-treated cells showed a remarkable decrease. Moreover, the downregulation of UHRF1 in both breast cancer cell lines significantly inhibited the colony formation capacity. Results suggested that the inhibition of UHRF1 via an RNA interference lentiviral system may provide an effective way for breast cancer therapy.
Assuntos
Neoplasias da Mama/genética , Proteínas Estimuladoras de Ligação a CCAAT/antagonistas & inibidores , Proteínas Estimuladoras de Ligação a CCAAT/genética , RNA Interferente Pequeno/administração & dosagem , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Regulação para Baixo , Resistência a Múltiplos Medicamentos , Feminino , Humanos , Interferência de RNA , RNA Interferente Pequeno/genética , Ensaio Tumoral de Célula-Tronco/métodos , Ubiquitina-Proteína LigasesRESUMO
The change in electrochemical behavior of tumor cells induced by antitumor drugs was detected by using a multiwall carbon nanotubes (MWNTs)-modified glass carbon electrode (GCE). Based on the changes observed, a simple, in vitro, electrochemical antitumor drug sensitivity test was developed. MWNTs promoted electron transfer between the electroactive centers of cells and the electrode. Leukemia K562 cells exhibited a well-defined anodic peak of guanine at +0.823 V at 50 mV s(-1). HPLC assay with ultraviolet detection was used to elucidate the reactant responsible for the electrochemical response of the tumor cells. The guanine content within the cytoplasm of each K562 cell was detected to be 920 amol. For the drug sensitivity tests, 5-fluorouracil (5-FU) and several clinical antitumor drugs, such as vincristine, adriamycin, and mitomycin C, were added to cell culture medium. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of MTT assays. In comparison to conventional methods, this electrochemical test is highly sensitive, accurate, inexpensive, and simple. The method proposed could be developed as a convenient means to study the sensitivity of tumor cells to antitumor drugs.
Assuntos
Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Eletroquímica/métodos , Leucemia/tratamento farmacológico , Nanotubos de Carbono/química , Doxorrubicina/farmacologia , Eletroquímica/instrumentação , Fluoruracila/farmacologia , Humanos , Células K562 , Microeletrodos , Mitomicina/farmacologia , Vincristina/farmacologiaRESUMO
A novel renewable reagentless hydrogen peroxide (H(2)O(2)) sensor based on the direct electron transfer of horseradish peroxidase (HRP) is proposed. The direct electrochemistry of HRP immobilized on a colloidal gold-modified carbon paste electrode (Au-CPE) was investigated using electrochemical methods. The immobilized HRP displayed a pair of redox peaks in 0.1M phosphate buffer (PB), pH 7.0, with a formal potential of -0.346 V. The response showed a surface-controlled electrode process with an electron transfer rate constant of 6.04+/-0.18s(-1) determined in the scan rate range from 120 to 500 mV/s. The biosensor displayed an excellent electrocatalytic response to the reduction of H(2)O(2) without the aid of an electron mediator. The sensor surface could be renewed quickly and reproducibly by a simple polish step. The calibration range of H(2)O(2) was 0-0.3mM with linear relation from 0.48 to 50 microM and a detection limit of 0.21 microM at 3 sigma. The response showed Michaelis-Menten behavior at higher H(2)O(2) concentrations. The K(app)(M) value of HRP at HRP-Au-CPE was determined to be 3.69+/-0.71 mM.
Assuntos
Técnicas Biossensoriais/instrumentação , Eletrodos , Coloide de Ouro , Peroxidase do Rábano Silvestre/metabolismo , Peróxido de Hidrogênio/análise , Eletroquímica , Transporte de Elétrons , Enzimas ImobilizadasRESUMO
A novel hepatitis B virus (HBV) DNA biosensor was developed by immobilizing covalently single-stranded HBV DNA fragments to a gold electrode surface via carboxylate ester to link the 3(')-hydroxy end of the DNA with the carboxyl of the thioglycolic acid (TGA) monolayer. A short-stranded HBV DNA fragment (181bp) of known sequence was obtained and amplified by PCR. The surface hybridization of the immobilized single-stranded HBV DNA fragment with its complementary DNA fragment was evidenced by electrochemical methods using [Os(bpy)(2)Cl(2)](+) as a novel electroactive indicator. The formation of double-stranded HBV DNA on the gold electrode resulted in a great increase in the peak currents of [Os(bpy)(2)Cl(2)](+) in comparison with those obtained at a bare or single-stranded HBV DNA-modified electrode. The mismatching experiment indicated that the surface hybridization was specific. The difference between the responses of [Os(bpy)(2)Cl(2)](+) at single-stranded and double-stranded DNA/TGA gold electrodes suggested that the label-free hybridization biosensor could be conveniently used to monitor DNA hybridization with a high sensitivity. X-ray photoelectron spectrometry technique has been employed to characterize the immobilization of single-stranded HBV DNA on a gold surface.
Assuntos
2,2'-Dipiridil/análogos & derivados , 2,2'-Dipiridil/química , Técnicas Biossensoriais , DNA Viral/análise , Vírus da Hepatite B/genética , Compostos Organometálicos/química , Reação em Cadeia da Polimerase/métodos , Pareamento Incorreto de Bases , DNA de Cadeia Simples/análise , DNA Viral/química , Eletroquímica/métodos , Ouro/química , Hibridização de Ácido Nucleico , Sensibilidade e Especificidade , Análise Espectral/métodos , Raios XRESUMO
A novel chemiluminescence (CL) method for the determination of papaverine (PAP) has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic permanganate. A mechanism for the CL reaction has been proposed on the basis of fluorescent and chemiluminescence spectra. The CL response is proportional to the concentration of PAP over the range 0.2-10 micro mol L(-1). The detection limit of PAP is 0.10 micro mol L(-1) (3 s) with a relative standard deviation (RSD) of 2.0% for 10 repetitive determinations of 1.0 micro mol L(-1) PAP. Interferences from other alkaloids in the opium, such as morphine and codeine, are negligible except that of narcotine. The method has been satisfactorily used for the determination of PAP in injections and compound liquorice tablets.
Assuntos
Análise de Injeção de Fluxo/métodos , Compostos de Manganês/química , Óxidos/química , Papaverina/análise , Cinética , Medições Luminescentes , Sensibilidade e EspecificidadeRESUMO
UV irradiation of 2-, 3-, or 4-pyridylacrylic acid (2-, 3-, and 4-HPYA) with Cu(I)Cl at 230 nm in 4 N HCl for 1 week and subsequent hydrothermal reactions yielded three novel highly stable 3-D copper(I)-olefin dimers, [(2-H(2)PYA)(2)Cu(+)(2)Cl(4)](n)() (1), [(3-H(2)PYA)(2)Cu(+)(2)Cl(4)](n)() (2), and [(4-H(2)PYA)(2)Cu(+)(2)Cl(4)(I)](n)() (3), respectively, in which H-bonds play a key role in the stabilization of supramolecular Cu(I)-olefin system and thus the formation of the 3-D networks. The electrochemical properties of 1-3 are also reported.