Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
J Dairy Sci ; 106(10): 6688-6700, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37558047

RESUMO

Milk-clotting enzyme (MCE) is the essential active agents in dairy processing. The traditional MCE is mainly obtained from animal sources, in which calf rennet is the most widely used in cheese industry. Traditional MCE substitute is becoming necessary due to its limited production and increased cheese consumption. A novel traditional MCE substitute was produced from Bacillus velezensis DB219 in this study. The DB219 MCE exhibited a notable specific activity of 6,110 Soxhlet units/mg and 3.16-fold purification yield with 28.87% recovery through ammonium sulfate fractionation and DEAE-Sepharose Fast Flow. The purified DB219 MCE was a metalloprotease with a molecular weight of 36 kDa. The DB219 MCE was weak acid resistance and stable at pH 6.0 to 10.0 and temperature <45°C. The highest milk-clotting activity was observed in substrate at pH 5.5 added with 20 to 30 mM CaCl2. The Michaelis constant and maximal velocity for casein were 0.31 g/L and 14.22 µmol/min. The DB219 MCE preferred to hydrolyze ß-casein instead of α-casein. The DB219 MCE hydrolyzed α-casein, ß-casein, and κ-casein to generate significantly different peptides in comparison with calf rennet and ES6023 MCE (fungal MCE) through SDS-PAGE and reversed-phase HPLC analysis. The DB219 MCE mainly cleaved Thr124-Ile125 and Ser104-Phe105 bonds in κ-casein and had unique casein cleavage sites and peptide composition through LC-MS/MS analysis. The DB219 MCE was potential to be a new milk coagulant and enriched kinds of traditional MCE substitute.


Assuntos
Queijo , Leite , Animais , Leite/química , Caseínas/química , Cromatografia Líquida/veterinária , Espectrometria de Massas em Tandem/veterinária , Metaloproteases , Peptídeos/análise , Queijo/análise
2.
Chem Biodivers ; 20(4): e202300146, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36919922

RESUMO

Febrifugine is a kind of quinazolinone compound with high biological activity from a Chinese herb called Chang Shan (Dichroa febrifuga). Febrifugine and its derivatives possess extensive biological activities, some of which exhibited anti-tumor activities as FAK inhibitors. However, they are not very effective at inhibiting tumor metastasis, perhaps because tumors gain energy through compensatory activation of other signaling pathways that promote cell migration and invasion. Therefore, seventeen novel febrifugine derivatives with quinazolinone skeleton were designed, synthesized and acted as potential FAK/PLK1 dual inhibitors. These compounds were determined by 1 H-NMR, 13 C-NMR and MS. Most of the compounds exhibited good inhibitory activity against cancer cell lines by computer-assisted screening, antitumor activity test and FAK/PLK1 inhibitory activity test, wherein compound 3b was screened as a high-efficiency lead compound.


Assuntos
Antineoplásicos , Inibidores de Proteínas Quinases , Quinazolinonas , Antineoplásicos/química , Linhagem Celular , Proliferação de Células , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Espectroscopia de Ressonância Magnética , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Quinazolinonas/química , Quinazolinonas/farmacologia , Esqueleto , Relação Estrutura-Atividade , Quinase 1 de Adesão Focal/antagonistas & inibidores , Quinase 1 Polo-Like
3.
Chem Biodivers ; 19(6): e202200189, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35510593

RESUMO

A series of novel quinazolinone hydrazide derivatives were designed and synthesized as EGFR inhibitors. The results indicated that most of the aimed compounds had potential anti-tumor cell proliferation and EGFR inhibitory activities. In the comprehensive analysis of all the tested compounds, the target compound 9c showed the best anti-tumor cell proliferation activity, (IC50 =1.31 µM for MCF-7, IC50 =1.89 µM for HepG2, IC50 =2.10 µM for SGC), and IC50 =0.59 µM for the EGFR inhibitory activity. Docking results showed that compound 9c could ideally insert the active site and interact with the critical amino acid residues (Val702, Lys721, Met769, Asp831) in the active site.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/química , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB , Humanos , Hidrazinas/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Quinazolinonas/química , Relação Estrutura-Atividade
4.
Indian J Microbiol ; 62(2): 273-279, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35462716

RESUMO

Glucosinolate (GSL) is an important active substance in broccoli and can be hydrolyzed to isothiocyanates (ITCs) by endogenous myrosinase. The ITCs are well-known chemopreventive agents that have received significant attention across the nutrition and pharmaceutical industries due to their anticancer properties. Myrosinase activity decreases during the cooking of broccoli, thus it is essential to study the microbiota involved in GSL hydrolysis to maximize their health benefits. In this study, two strains (Enterococcus gallinarum HG001 and Escherichia coli HG002) isolated from the gut microbiota of C57BL/6 mice were identified through 16 S rRNA gene sequence and characteristic analyses. The maximum GSL hydrolysis activity of 12 strains was observed using the cyclocondensation method. Their growth curves, GSL-hydrolysis curves, ITC generation curves and GSL-hydrolysis products were analyzed. The En. gallisepticum HG001 hydrolyzed GSL to a greater level than the E. coli HG002. It was observed that they could hydrolyze GSL to produce erucin nitrile and 4-methylsulfanylbutyro nitrile through gas chromatography-mass spectrometer analysis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01006-z.

5.
Opt Express ; 27(6): 8683-8695, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-31052681

RESUMO

We have theoretically and experimentally investigated the evolution of the temporal contrast in a 10-PW-level Ti:sapphire laser in the Shanghai Superintense Ultrafast Laser Facility (SULF). The effects induced by the grism pair, spectral shaping filter, and increase in gain on the temporal contrast were investigated. First, it was found that the energy loss of clean seed pulses in the grism pair is a major factor in contrast degradation. Because of the low transmission efficiency of the grism pair (~10%), the temporal contrast is degraded by one order of magnitude. Second, the spectral shaping filter in the regenerative amplifier degrades the temporal contrast by increasing the intracavity loss. Finally, as the amplified spontaneous emission pedestal experiences gain more than the main pulse in Ti:sapphire amplifiers, particularly during saturated amplification, the temporal contrast will further deteriorate as the gain increases in multi-stage Ti:sapphire amplifiers. In addition, the effect on the temporal contrast induced by the extraction during pumping technique in large-aperture Ti:sapphire amplifiers has been considered. According to the investigations described above, the design of the SULF can be further improved. It is predicted that a temporal contrast of over 10-11 can be achieved at a peak power of 10 PW following the improvements. The investigations conducted in this study can provide guidelines for improving the temporal contrast in ultrahigh-peak-power Ti:sapphire lasers.

6.
Int J Food Sci Nutr ; 70(5): 585-594, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30773072

RESUMO

After consuming broccoli, isothiocyanates can be produced by the hydrolytic action of myrosinase from plant and/or microbiota. Using male C57BL/6 mice, the present study investigated the effects of broccoli ingestion on the myrosinase-like activity, NAD(P)H:quinone oxidoreductase 1 (NQO1) activity, diversity and composition of the gut microbiota. Compared with the control group, continuously feeding raw or hydrolysed broccoli increased the myrosinase-like activities of the colon and caecum contents, and also improved the NQO1 activity of the colon mucosa. Significant difference between the broccoli and control feeding groups were found. 16S rRNA gene sequencing indicated that broccoli ingestion profoundly affected the composition of the gut bacteria community. The correlation between the gut bacterial community composition and microbiota myrosinase-like activity was also studied. However, one type of glucosinolate, sinigrin, had no effect on these activities, indicating that broccoli component(s), other than glucosinolate, had increased the NQO1 and myrosinase-like activities.


Assuntos
Brassica/metabolismo , Ingestão de Alimentos , Microbioma Gastrointestinal/fisiologia , Glucosinolatos/metabolismo , NAD(P)H Desidrogenase (Quinona)/metabolismo , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Ceco/microbiologia , Colo/microbiologia , Microbioma Gastrointestinal/genética , Glicosídeo Hidrolases , Hidrólise , Mucosa Intestinal , Isotiocianatos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , RNA Ribossômico 16S/genética
7.
Arch Toxicol ; 92(11): 3391-3402, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30238133

RESUMO

Triclosan, a widely used broad spectrum anti-bacterial agent, is hepatotoxic in rodents and exhibits differential effects on mouse and human peroxisome proliferator-activated receptor alpha (PPARα) in vitro; however, the mechanism underlying triclosan-induced liver toxicity has not been elucidated. This study examined the role of mouse and human PPARα in triclosan-induced liver toxicity by comparing the effects between wild-type and PPARα-humanized mice. Female mice of each genotype received dermal applications of 0, 58, or 125 mg triclosan/kg body weight daily for 13 weeks. Following the treatment, triclosan caused an increase in liver weight and relative liver weight only in wild-type mice. The expression levels of PPARα target genes cytochrome P450 4A and acyl-coenzyme A oxidase 1 were increased in livers of both wild-type and PPARα-humanized mice, indicating that triclosan activated PPARα. Triclosan also elevated the expression levels of peroxisomal membrane protein PMP70 and catalase in the livers of both genotypes, suggesting that triclosan promoted the production of hepatocyte peroxisomes. There was an enhanced expression of cyclin D1, c-myc, proliferating cell nuclear antigen, and Ki67, and a higher percentage of BrdU-labeled hepatocytes in wild-type mice, but not in PPARα-humanized mice, demonstrating triclosan-activated PPARα had differential effects on the hepatocyte proliferation. These findings imply that the differential effects of triclosan-activated PPARα on cell proliferation may play a role in the species differences in triclosan-induced liver toxicity.


Assuntos
Fígado/efeitos dos fármacos , PPAR alfa/fisiologia , Triclosan/toxicidade , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/fisiologia , Humanos , Antígeno Ki-67/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/efeitos dos fármacos , Peroxissomos/efeitos dos fármacos , Especificidade da Espécie
8.
Arch Toxicol ; 91(6): 2405-2423, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27896399

RESUMO

Triclosan is a widely used broad-spectrum anti-bacterial agent. The objectives of this study were to identify which cytochrome P450 (CYP) isoforms metabolize triclosan and to examine the effects of CYP-mediated metabolism on triclosan-induced cytotoxicity. A panel of HepG2-derived cell lines was established, each of which overexpressed a single CYP isoform, including CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2A7, CYP2A13, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP4A11, and CYP4B1. The extent of triclosan metabolism by each CYP was assessed by reversed-phase high-performance liquid chromatography with online radiochemical detection. Seven isoforms were capable of metabolizing triclosan, with the order of activity being CYP1A2 > CYP2B6 > CYP2C19 > CYP2D6 ≈ CYP1B1 > CYP2C18 ≈ CYP1A1. The remaining 11 isoforms (CYP2A6, CYP2A7, CYP2A13, CYP2C8, CYP2C9, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP4A11, and CYP4B1) had little or no activity toward triclosan. Three metabolites were detected: 2,4-dichlorophenol, 4-chlorocatechol, and 5'-hydroxytriclosan. Consistent with the in vitro screening data, triclosan was extensively metabolized in HepG2 cells overexpressing CYP1A2, CYP2B6, CYP2C19, CYP2D6, and CYP2C18, and these cells were much more resistant to triclosan-induced cytotoxicity compared to vector cells, suggesting that CYP-mediated metabolism of triclosan attenuated its cytotoxicity. In addition, 2,4-dichlorophenol and 4-chlorocatechol were less toxic than triclosan to HepG2/vector cells. Conjugation of triclosan, catalyzed by human glucuronosyltransferases (UGTs) and sulfotransferases (SULTs), also occurred in HepG2/CYP-overexpressing cells and primary human hepatocytes, with a greater extent of conjugation being associated with higher cell viability. Co-administration of triclosan with UGT or SULT inhibitors led to greater cytotoxicity in HepG2 cells and primary human hepatocytes, indicating that glucuronidation and sulfonation of triclosan are detoxification pathways. Among the 18 CYP-overexpressing cell lines, an inverse correlation was observed between cell viability and the level of triclosan in the culture medium. In conclusion, human CYP isoforms that metabolize triclosan were identified, and the metabolism of triclosan by CYPs, UGTs, and SULTs decreased its cytotoxicity in hepatic cells.


Assuntos
Antibacterianos/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Hepatócitos/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Triclosan/toxicidade , Antibacterianos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , Glucuronosiltransferase/metabolismo , Células Hep G2 , Hepatócitos/enzimologia , Humanos , Isoenzimas , Microssomos Hepáticos/enzimologia , Cultura Primária de Células , Sulfotransferases/metabolismo , Triclosan/metabolismo
9.
Arch Toxicol ; 89(8): 1297-311, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25033989

RESUMO

Triclosan is a broad spectrum anti-bacterial agent widely used in many personal care products, household items, medical devices, and clinical settings. Human exposure to triclosan is mainly through oral and dermal routes. In previous studies, we found that sub-chronic dermal exposure of B6C3F1 mice to triclosan induced epidermal hyperplasia and focal necrosis; however, the mechanisms for these responses remain elusive. In this study, using mouse epidermis-derived JB6 Cl 41-5a cells, we found that triclosan stimulated cell growth in a concentration- and time-dependent manner. Enhanced cell proliferation was demonstrated by a substantial increase in the percentage of BrdU-positive cells, an elevation in the protein levels of cyclin D1 and cyclin A, and a reduction in the protein level of p27(Kip1). Western blotting analysis revealed that triclosan induced the activation of extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), p38, and Akt. Pre-treatment of the cells with PD184352, an inhibitor of the upstream kinase MEK1/2, or with wortmannin, an inhibitor of phosphoinositide 3-kinase, blocked triclosan-mediated phosphorylation of ERK1/2 and Akt, respectively, and substantially suppressed triclosan-stimulated cell proliferation, whereas the JNK inhibitor SP600125 or the p38 inhibitor SB203580 had little to no effect on triclosan-stimulated cell proliferation. The phosphorylation activation of ERK1/2 and Akt was further confirmed on the skin of mice dermally administered triclosan. These data suggest that the activation of ERK1/2 and Akt is involved in triclosan-stimulated proliferation of JB6 Cl 41-5a cells.


Assuntos
Anti-Infecciosos Locais/toxicidade , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Triclosan/toxicidade , Animais , Western Blotting , Técnicas de Cultura de Células , Linhagem Celular , Ensaio Cometa , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Feminino , Camundongos Endogâmicos , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Fatores de Tempo
10.
Phys Med Biol ; 69(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38768601

RESUMO

Objective.Multi-phase computed tomography (CT) has become a leading modality for identifying hepatic tumors. Nevertheless, the presence of misalignment in the images of different phases poses a challenge in accurately identifying and analyzing the patient's anatomy. Conventional registration methods typically concentrate on either intensity-based features or landmark-based features in isolation, so imposing limitations on the accuracy of the registration process.Method.We establish a nonrigid cycle-registration network that leverages semi-supervised learning techniques, wherein a point distance term based on Euclidean distance between registered landmark points is introduced into the loss function. Additionally, a cross-distillation strategy is proposed in network training to further improve registration performance which incorporates response-based knowledge concerning the distances between feature points.Results.We conducted experiments using multi-centered liver CT datasets to evaluate the performance of the proposed method. The results demonstrate that our method outperforms baseline methods in terms of target registration error. Additionally, Dice scores of the warped tumor masks were calculated. Our method consistently achieved the highest scores among all the comparing methods. Specifically, it achieved scores of 82.9% and 82.5% in the hepatocellular carcinoma and the intrahepatic cholangiocarcinoma dataset, respectively.Significance.The superior registration performance indicates its potential to serve as an important tool in hepatic tumor identification and analysis.


Assuntos
Processamento de Imagem Assistida por Computador , Neoplasias Hepáticas , Tomografia Computadorizada por Raios X , Humanos , Processamento de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Aprendizado de Máquina Supervisionado
11.
Chempluschem ; 89(4): e202300475, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37903722

RESUMO

The nitrogen and sulfur co-doped graphene aerogel (SNGA) was synthesized by a one-pot hydrothermal route using graphene oxide as the starting material and thiourea as the S and N source. The obtained SNGA with a three-dimensionally hierarchical structure, providing more available pathways for the transport of lithium ions. The existing form of S and N was regulated by changing the calcination temperature and thiourea doping amount. The results revealed that high temperature could decompose -SOX- functional groups and promote the transformation of C-S-C to C-S, ensuring the cyclic stability of electrode materials, and increasing the thiourea dosage amount introduced more pyridine nitrogen, improving the multiplicative performance of electrode materials. Benefiting from the synergistic effect of sulfur and nitrogen atoms, the prepared SNGA showed superior rate capability (107.8 mAh g-1 at 5 A g-1), twice more than that of GA (52.8 mAh g-1), and excellent stability (232.1 mAh g-1 at 1 A g-1 after 300 cycles), 1.85 times more than that of GA (125.6 mAh g-1). The present study provides a detailed report on thiourea as a dopant to provide a sufficient basis for SNGA and a theoretical guide for further modifying.

12.
J Colloid Interface Sci ; 664: 868-881, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38493652

RESUMO

Conversion of CO2 into high value-added fuels through the photothermal effect is an effective approach for utilizing solar energy. In this study, we prepared the CN-based photocatalyst Py-CTN-Au with both donor-acceptor (D-A) system and dual photothermal effects using a simple two-step method involving calcination and photo-deposition. Real-time monitoring with a thermal imaging camera revealed that Py-CTN-Au0.5 achieved a maximum stable temperature of 180 °C, which was approximately 1.2 times higher than that of Py-CTN (155 °C) and 1.9 times higher than that of g-CN (95 °C) under the same reaction conditions. Under the optimized reaction conditions, Py-CTN-Au0.5 exhibited a CO release rate of 30.59 umol g-1 after 4 h of reaction, which was 7.3 times higher than that of pure g-CN (4.18 umol g-1). The D-A system not only facilitated the separation and transformation of charge carriers but also induced a photothermal effect to accelerate the photoreduction of CO2. Additionally, the cocatalyst Au nanoparticles (Au NPs) further enhanced the charge carrier dynamics and photothermal effect by increasing the built-in electric field intensity and localized surface plasmon resonance (LSPR) effect, respectively. The dual photothermal effects resulting from the non-radiative photon conversion of the D-A structure and the Au NPs LSPR effect, along with the enhanced charge carrier dynamics, catalyzed the efficient photoreduction of CO2. DFT simulations were used to confirm the effect of D-A system and Au NPs. In-situ FTIR results demonstrated that the synergistic photothermal effect promoted the formation of the key intermediate species COOH*, which is beneficial for the photocatalytic reduction of CO2. This study provides valuable insights into the multiple photothermal synergistic effects in photocatalytic reactions.

13.
Quant Imaging Med Surg ; 14(1): 160-178, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38223056

RESUMO

Background: The 2-dimensional proximal isovelocity surface area (2D PISA) method underestimates tricuspid regurgitation (TR) severity. Previously proposed correction algorithms should be further scrutinized. Methods: Two correction algorithms were tested. One approach involves dividing the 2D PISA effective regurgitant orifice area by a constant of 0.7 (EROA0.7). Another approach involves multiplying the unadjusted EROA by Vorifice/(Vorifice - Valiasing), where Vorifice denotes the TR jet velocity, and Valiasing represents the color aliasing velocity (EROAVo-Va). In vitro validation was performed on a commercially available multifunctional valve tester with different size orifices and peak pressure gradients. A true EROA was derived through the regurgitant volume (RVol) calculated from the tester. For clinical validation, RVol was calculated as the difference between the overall stroke volume and the forward stroke volume of the right ventricle. Volumetric EROA was derived by dividing the RVol by the TR velocity-time integral (VTI). The vena contracta area (VCA) was obtained through direct planimetry with 3D echocardiography. The mean of volumetric EROA and VCA served as the reference in clinical validation. Results: Excellent correlation between the calculated EROAs and the true EROA was observed in vitro (r=0.98, r=0.97, and r=0.98 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively; all P values <0.0001). EROAVo-Va underestimated the true EROA and averaged 33% (P=0.3163), while EROA0.7 overestimated the true EROA and averaged 8% (P=0.0032). Clinically, these methods consistently exhibited a notable underestimation that varied with the reference EROA. This systematic underestimation was mitigated by both algorithms when either the VCA (biases of 19.6, 15.1, and 11.8 mm2 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively) or the volumetric EROA (biases of 10.1, 5.6, and 2.3 mm2 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively) served as the reference. Their ability to distinguish severe TR was similar, with area under the curve values of 0.905, 0.903, and 0.893 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively. No statistically significant differences were observed for diagnostic accuracy (all P values >0.05). Conclusions: Using a correction factor of 0.7 in quantifying TR provides similar accuracy when compared to other techniques. This represents a valuable clinical tool for quickly correcting the underestimation of the 2D PISA method in TR. This simple method may increase the frequency of applying the correction and earlier recognition of patients with severe TR.

14.
Food Res Int ; 172: 113202, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37689949

RESUMO

Milk-clotting enzyme (MCE) is a crucial active agent in cheese making. It is necessary to find traditional MCE substitutes due to the limited production of traditional MCE (e.g., calf rennet) and increased cheese consumption. Bacillus megaterium strain LY114 with good milk-clotting activity (MCA) (448 SU/mL) and a high MCA/proteolytic activity (PA) ratio (6.0) was isolated and identified from agricultural soil in Laiyang (Shandong, China) through 16S rRNA sequencing of 45 strains. The Bacillus megaterium LY114 MCE had a remarkable specific activity (7532 SU/mg) and displayed a 4.83-fold purification yield with 34.17% recovery through ammonium sulfate fractionation and DEAE-Sepharose Fast Flow. The purified LY114 MCE was a metalloprotease with a molecular weight of 30 kDa. LY114 MCE was stable at pH 5.0-7.0 and temperature <40 °C. The highest MCA appeared at a substrate pH of 5.5 with 30 mM CaCl2. The Michaelis constant (Km) and maximal velocity (Vm) for casein were 0.31 g/L and 14.16 µmol/min, respectively. LY114 MCE preferred to hydrolyze α-casein (α-CN) rather than ß-casein (ß-CN) and had unique α-CN, ß-CN and κ-casein (κ-CN) cleavage sites. LY114 MCE hydrolyzed casein to generate significantly different peptides compared with calf rennet and fungal MCE as determined by SDS-PAGE analysis. Chemical index analysis and sensory evaluation confirmed the usefulness of LY114 MCE in cheese making. LY114 MCE had the potential to be used in dairy processing and enriched traditional MCE substitutes.


Assuntos
Bacillus megaterium , Queijo , Caseínas , RNA Ribossômico 16S/genética
15.
Artigo em Inglês | MEDLINE | ID: mdl-38082966

RESUMO

Liver cancer is a part of the common causes of cancer death worldwide, and the accurate diagnosis of hepatic malignancy is important for effective next treatment. In this paper, we propose a convolutional neural network (CNN) based on a spatiotemporal excitation (STE) module for identification of hepatic malignancy in four-phase computed tomography (CT) images. To enhance the display detail of lesion, we expand single-channel CT images into three channels by using the channel expansion method. Our proposed STE module consists of a spatial excitation (SE) module and a temporal interaction (TI) module. The SE module calculates the temporal differences of CT slices at the feature level, which is used to excite shape-sensitive channels of the lesion features. The TI module shifts a portion of the channels in the temporal dimension to exchange information among the current CT slice and adjacent CT slices. Four-phase CT images of 398 patients diagnosed with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are used for experiments and five cross-validations are performed. Our model achieved average accuracy of 85.00% and average AUC of 88.91% for classifying HCC and ICC.Clinical Relevance- The proposed deep learning-based model can perform HCC and ICC recognition tasks based on four-phase CT images, assisting doctors to obtain better diagnostic performance.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Redes Neurais de Computação
16.
Artigo em Inglês | MEDLINE | ID: mdl-38083466

RESUMO

Liver cancer has been one of the top causes of cancer-related death. For developing an accurate treatment strategy and raising the survival rate, the differentiation of liver cancers is essential. Multiphase CT recently acts as the primary examination method for clinical diagnosis. Deep learning techniques based on multiphase CT have been proposed to distinguish hepatic cancers. However, due to the recurrent mechanism, RNN-based approaches require expensive calculations whereas CNN-based models fail to explicitly establish temporal correlations among phases. In this paper, we proposed a phase difference network, termed as Phase Difference Network (PDN), to identify two liver cancer, hepatocellular carcinoma and intrahepatic cholangiocarcinoma, from four-phase CT. Specifically, the phase difference was used as interphase temporal information in a differential attention module, which enhanced the feature representation. Additionally, utilizing a multihead self-attention module, a transformer-based classification module was employed to explore the long-term context and capture the temporal relation between phases. Clinical datasets are used in experiments to compare the performance of the proposed strategy versus conventional approaches. The results indicate that the proposed method outperforms the traditional deep learning based methods.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Redes Neurais de Computação , Neoplasias Hepáticas/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Atenção , Tomografia Computadorizada por Raios X/métodos
17.
Food Funct ; 14(7): 3083-3091, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36917481

RESUMO

Patulin is one of the mycotoxins that exists in abundance in fruits and derivative products and is easily exposed in daily life, leading to various toxicities such as genotoxicity, teratogenicity, immunotoxicity, and carcinogenicity in the human body, while the efficient removal or degradation measures are still in urgent demand. In this work, Saccharomyces cerevisiae, a natural yeast with both patulin degradation and intestine damage protection abilities, was first applied to prevent and decrease the hazard after patulin intake. In vitro, Saccharomyces cerevisiae KD (S. cerevisiae KD) could efficiently degrade patulin at high concentrations. In a Canenorhabditis elegans (C. elegans) model fed on S. cerevisiae KD, locomotion, oxidative stress, patulin residual, intestine damage, and gene expression were investigated after exposure to 50 µg mL-1 patulin. The results demonstrated that S. cerevisiae KD could efficiently degrade patulin, as well as weaken the oxidative stress and intestinal damage caused by patulin. Moreover, S. cerevisiae KD could regulate the gene expression levels of daf-2 and daf-16 through the IGF-1 signaling pathway to control the ROS level and glutathione (GSH) content, thus decreasing intestinal damage. In summary, this work uncovers the outstanding characteristic of an edible probiotic S. cerevisiae KD in patulin degradation and biotoxicity alleviation and provides enlightenment toward solving the hazards caused by the accumulation of patulin.


Assuntos
Patulina , Animais , Humanos , Patulina/toxicidade , Saccharomyces cerevisiae/metabolismo , Caenorhabditis elegans/metabolismo , Estresse Oxidativo , Dano ao DNA
18.
Quant Imaging Med Surg ; 13(8): 5089-5099, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37581071

RESUMO

Background: Current guidelines recommend integrating several echocardiographic indices to evaluate the severity of tricuspid regurgitation (TR). Discordance of indices, including qualitative and quantitative methods, commonly exists in practice. The discordance among these parameters has not yet been fully elucidated. Methods: A total of 127 patients with recognizable TR jets without pulmonary regurgitation or intracardiac shunt were prospectively enrolled. We evaluated 8 parameters by 2-dimensional (2D) echocardiography: proximal iso-velocity surface area (PISA)-derived regurgitant volume (RVol), PISA-derived effective regurgitant orifice area (EROA), PISA radius, vena contracta width (VCW), color Doppler jet area, tricuspid valve annular diameter, inferior vena cava (IVC) diameter, and peak E wave. According to current guidelines, each echocardiographic parameter was determined to represent either severe or non-severe TR. A concordance score was calculated as the number of concordant parameters divided by 8, with a higher score reflecting better concordance. Data were further categorized into 3 subgroups: complete concordance (0 discordant parameters), high concordance (1-2 discordant parameters), and low concordance (3-4 discordant parameters). Results: The mean concordance score was 81%±17% for the entire cohort. There were 48 (38%) patients with complete concordance, including 6 patients with severe TR. In contrast, the low concordance group (n=43, 34%) mostly comprised severe TR patients (36 patients). When considering only EROA, RVol, and VCW, concordance improved, with 98 patients (77%) in complete agreement. Conclusions: Concordance seems limited when using echocardiographic parameters to assess TR severity. Applying only EROA, RVol, and VCW results in better concordance, as recommended by the current guidelines.

19.
J Agric Food Chem ; 71(49): 19189-19206, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-37963243

RESUMO

The production of saffron spice results in numerous byproducts, as only 15 g of spice can be produced from 1 kg of flowers, indicating that over 90% of the saffron flower material is eventually discarded as waste. In view of this, the paper reviews current knowledge on the natural active components in saffron byproducts and their biological activities, aiming to lay a theoretical and scientific foundation for the further utilization. Saffron byproducts contain a variety of phytochemical components, such as flavonoids, anthocyanins, carotenoids, phenolic acids, monoterpenoids, alkaloids, glycosides, and saponins. The activities of saffron byproducts and their mechanisms are also discussed in detail here.


Assuntos
Produtos Biológicos , Crocus , Antocianinas , Extratos Vegetais/farmacologia , Carotenoides , Antioxidantes , Flores , Corantes
20.
Foods ; 12(24)2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38137237

RESUMO

Vibrio parahaemolyticus is a halophilic and heat-labile gram-negative bacterium and is the most prevalent foodborne bacterium in seafood. In order to develop a rapid and sensitive method for detecting the foodborne pathogenic bacterium Vibrio parahaemolyticus, an aptamer-modified magnetic nanoparticle and an aptamer-modified upconversion nanoparticle were synthesised and used as a capture probe and a signal probe, respectively. The aptamer-modified magnetic nanoparticle, V. parahaemolyticus cell, and aptamer-modified upconversion nanoparticle formed a sandwich-like complex, which was rapidly separated from a complex matrix using a magnetic force, and the bacterial concentration was determined by fluorescence intensity analysis. The results showed that the fluorescence intensity signal correlated positively with the concentration of V. parahaemolyticus in the range of 3.2 × 102 to 3.2 × 105 CFU/mL, with a linear equation of y = 296.40x - 217.67 and a correlation coefficient of R2 = 0.9610. The detection limit of the developed method was 4.4 CFU/mL. There was no cross-reactivity with other tested foodborne pathogens. This method is highly specific and sensitive for the detection of V. parahaemolyticus, and can achieve the qualitative detection of this bacterium in a complex matrix.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA