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1.
J. appl. oral sci ; 32: e20230439, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1558238

RESUMO

Abstract Objective To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety under occlusal loading. Methodology Three-dimensional finite element models were generated for maxillary central incisors with all-ceramic crown restorations. The labiolingual diameters of the tooth, defined as the horizontal distance between the protrusion of the labial and lingual surfaces, were changed as follows: (D1) 6.85 mm, (D2) 6.35 mm, and (D3) 5.85 mm. The model was constructed as follows: (S0) vital pulp tooth; (S1) ET tooth; (S2) ET tooth with a 2 mm ferrule, restored with a fiber post and composite resin core; (S3) ET tooth without a ferrule, restored with a fiber post and composite resin core. A total of 12 models were developed. In total, two force loads (100 N) were applied to the crown's incisal edge and palatal surface at a 45° oblique angle to the longitudinal axis of the teeth. The Von Mises stress distribution and maximum stress of the models were analyzed. Results Regardless of the loading location, stress concentration and maximum stress (34.07~66.78MPa) in all models occurred in the labial cervical 1/3 of each root. Both labiolingual diameter and construction influenced the maximum stress of the residual tooth tissue, with the impact of the labiolingual diameter being greater. A reduction in labiolingual diameter led to increased maximum stress throughout the tooth. The ferrule reduced the maximum stress of the core of S2 models (7.15~10.69 MPa), which is lower compared with that of S3 models (19.45~43.67 MPa). Conclusion The labiolingual diameter exerts a greater impact on the biomechanical characteristics of ET anterior teeth with crown restoration, surpassing the influence of the construction. The ferrule can reduce the maximum stress of the core and maintain the uniformity of stress distribution.

2.
Eur Thyroid J ; 12(6)2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37855414

RESUMO

Background: Incidence rates of papillary thyroid cancer (PTC) have increased rapidly, with incidentally detected cancers contributing a large proportion. We aimed to explore the impact of incidental detection on thyroid cancer-specific and competing mortality among PTC patients. Methods: We conducted a retrospective cohort study of PTC patients at a cancer center in Guangzhou. Baseline information on detection route and other covariates were collected between 2010 and 2018, and death outcome was followed up for each patient. Cumulative incidence functions were used to estimate the mortality risk of thyroid cancer and competing risk. Cause-specific hazard models were then utilized to explore the association between detection routes and PTC-specific and competing mortality. Results: Of the 2874 patients included, 2011 (70.0%) were detected incidentally, and the proportion increased from 36.9% in 2011 to 82.3% in 2018. During a median follow-up of 5.6 years, 42 deaths occurred, with 60% of them due to competing causes. The probability of competing mortality at 5 years in the non-incidental group and incidental group was 1.4% and 0.4%, respectively, and PTC-specific mortality in the non-incidental group and incidental group was 1.0% and 0.1%, respectively. After adjusting for covariates, the HRs of incidental detection were 0.13 (95% CI: 0.04-0.46; P = 0.01) and 0.47 (95% CI: 0.20-1.10; P = 0.10) on PTC-specific mortality and competing mortality, respectively. Conclusions: Incidental detection is associated with a lower risk of PTC-specific and competing mortality. Under the context of increasing magnitude of overdiagnosis, incorporation of detection route in clinical decision-making might be helpful to identify patients who might benefit from more extensive or conservative therapeutic strategies.


Assuntos
Neoplasias da Glândula Tireoide , Humanos , Câncer Papilífero da Tireoide/diagnóstico , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico , Risco , Incidência
3.
Biomed Pharmacother ; 165: 115117, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37406509

RESUMO

An increasing body of research suggests cancer-induced cardiovascular diseases, leading to the appearance of an interdisciplinary study known as onco-cardiology. Lung cancer has the highest incidence and mortality. Cardiac dysfunction constitutes a major cause of death in lung cancer patients. However, its mechanism has not been elucidated because suitable animal models that adequately mimic clinical features are lacking. Here, we established a novel chemically induced lung cancer mouse model using benzo[a]pyrene and urethane to recapitulate the general characteristics of cardiac dysfunction caused by lung cancer, the cardiac disorders in the context of the progression of lung cancer were evaluated using echocardiographic and histological approaches. The pathological changes included myocardial ischaemia, pericarditis, cardiac pre-cachexia, and pulmonary artery hypertension. We performed sequencing to detect the tRNA-derived fragments and tRNA-derived stress-induced RNAs (tRFs/tiRNAs) expressions in mouse heart tissue. 22 upregulated and 16 downregulated tRFs/tiRNAs were identified. Subsequently, the top 10 significant results of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were presented. The in vitro model was established by exposing neonatal rat cardiomyocytes and myocardial fibroblasts to lung tumour cell-conditioned medium, respectively. Western blotting revealed significant changes in cardiac failure markers (atrial natriuretic peptide and α-myosin heavy chain) and cardiac fibrosis markers (Collagen-1 and Collagen-3). Our model adequately reflects the pathological features of lung cancer-induced cardiac dysfunction. Furthermore, the altered tRF/tiRNA profiles showed great promise as novel targets for therapies. These results might pave the way for research on therapeutic targets in onco-cardiology.


Assuntos
Cardiologia , Cardiopatias , Neoplasias Pulmonares , Ratos , Camundongos , Animais , RNA de Transferência/genética , RNA de Transferência/metabolismo , Neoplasias Pulmonares/genética , Colágeno
4.
Crit Rev Eukaryot Gene Expr ; 33(2): 13-25, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36734854

RESUMO

Long non-coding RNA LMCD1 antisense RNA 1 (LMCD1-AS1) has recently been reported to participate in the pathogenesis of several tumors, including thyroid cancer and osteosarcoma. However, the clinical significance of LMCD1-AS1 and the related biological function have not been reported in cervical cancer (CC). In this study, we observed that LMCD1-AS1 expression was highly expressed in CC specimens compared with adjacent normal specimens using quantitative real-time PCR. Chi-square test showed that high LMCD1-AS1 expression was correlated with FIGO stage and lymph node metastasis. Kaplan-Meier survival analysis showed poor prognosis with high LMCD1-AS1 expression. Moreover, FIGO stage, lymph node metastasis and high LMCD1-AS1 expression could be independent prognostic factors for the patients with CC. Functionally, knockdown of LMCD1-AS1 suppressed the proliferation, migration and invasion of two CC cell lines (HeLa and CaSki) cells by CCK-8 assay, colony formation assay, and Transwell assay. Knockdown of LMCD1-AS1 upregulated E-cadherin expression and downregulated the expression of PCNA, N-cadherin, and imentin in HeLa and CaSki cells. Luciferase reporter assay and RIP assay were conducted to evaluate the downstream molecular mechanisms of LMCD1-AS1. LMCD1-AS1 possesses a putative miR-873-3p-binding site and confirmed the negative correlation between them in CC tissues. Moreover, overexpression of LMCD1-AS1 promoted CC cell proliferation and EMT process through the regulation of miR-873-3p. In addition, depletion of LMCD1-AS1 reduced tumor growth and Ki-67 protein expression. In summary, our findings indicate that LMCD1-AS1 might exert an oncogenic role in CC and targeting LMCD1-AS1 might be a promising therapeutic target for CC treatment.


Assuntos
Neoplasias Ósseas , MicroRNAs , RNA Longo não Codificante , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias Ósseas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Metástase Linfática , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Transição Epitelial-Mesenquimal
5.
Front Chem ; 10: 969770, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36147251

RESUMO

With the purpose to improve antiproliferative activity, 26 new betulonic acid-diazine derivatives were designed and synthesized from betulinic acid. The anticancer activity of these semi-synthetic compounds was evaluated by MTT assay in both tumor cell lines and normal cell line. The results indicated that majority of new compounds exhibited improved antitumor activity compared with the parent compound betulonic acid. Compound BoA2C, in particular, had the most significant action with IC50 value of 3.39 µM against MCF-7 cells, while it showed lower cytotoxicity on MDCK cell line than cisplatin. Furthermore, we discovered that BoA2C strongly increased MCF-7 cell damage mostly by influencing arginine and fatty acid metabolism. In addition, the structure-activity relationships were briefly discussed. The results of this study suggested that the introduction of different diazines at C-28 could selectively inhibit different kinds of cancer cells and might be an effective way to synthesize potent anticancer lead compound from betulonic acid.

6.
Talanta ; 236: 122876, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635256

RESUMO

Metal nanoclusters (NCs) as promising nanomaterials for sensing applications have attracted significant attention because of their unique photoluminescence properties. However, the quantum yields of metal NCs are still relatively low when compared to conventional quantum dots and organic dyes, posing a major obstacle to their assay application. It is challenging but important to pursue a way to improve the luminescence of metal NCs. In this work, we developed a novel strategy to enhance the luminescence of silver nanoclusters (Ag NCs) based on the binding with 6-aza-2-thiothymine (ATT) via Au3+ bridging. We studied the possible mechanism of this binding-induced luminescence enhancement and attributed it to the ligands rigidifying. Since 2-thiouracil (2-TU), a common anticancer, antithyroid, and antiviral agent, featured a similar molecular structure of ATT, this luminescence enhancement strategy can be designed to sensitive and selective turn-on detect 2-TU. As far as we know, this is the first report for the fluorescent turn-on detect 2-TU. Benefiting from the good performance of this method and the advantages of fluorescence assay, intracellular imaging of 2-TU, which has yet to be achieved based on currently developed analytical methods for 2-TU, was carried out via our approach. Moreover, to further expand the sensing application of the developed luminescence enhancement method, we constructed a universal detection platform. Taking hyaluronidase as a target, the feasibility of the detection platform was confirmed. The discoveries in this study offer a simple route to improve the optical properties of NCs and design their sensing applications.


Assuntos
Luminescência , Nanopartículas Metálicas , Hialuronoglucosaminidase , Prata , Tiouracila
7.
Food Sci Nutr ; 9(9): 4722-4737, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34531986

RESUMO

AIM: The purpose of this research was to evaluate lncRNA FEZF1-AS1 in cervical cancer development and clinical significance. MATERIALS AND METHODS: Collecting cervical cancer tissues, measuring FEZF1-AS1 expression, and analysis correlation between FEZF1-AS1 and prognosis. In cell vitro study, using MTT assay to measure cell proliferation, evaluating cell apoptosis by flow cytometry, measuring cell invasion and migration by Transwell and wound healing assay; lncRNA FEZF1-AS1 and miR-1254 gene expressions were evaluated by RT-qPCR assay; relative protein (Smurf1, E-cadherin, Vimentin, N-cadherin, AKT, p-AKT, c-Myc, and ZEB1) expressions were measured by Western blot assay. The correlation among FEZF1-AS1, miR-1254, and Smurf1 were analysis by dual luciferase reporter gene assay. RESULTS: By clinical analysis, lncRNA FEZF1-AS1 was high expression in cervical cancer tissues and high expression was closely correlated with poor prognosis in cervical cancer patients. In vitro study, the SiHa and HeLa cell biologically including cell proliferation, migration, and invasion of si-FEZF1-AS1 group which knockdown lncRNA FEZF1-AS1 were significantly depressed (p < .001, respectively). However, with miR-1254 expression inhibiting, the cell biological activities were significantly increased in si-FEZF1-AS1+miRNA inhibitor groups (p < .001, respectively). CONCLUSION: lncRNA FEZF1-AS1 might be an oncological role in cervical cancer; lncRNA FEZF1-AS1 knockdown had antitumor effects with miR-1254 activating in cervical cancer by in vitro study.

8.
J Fluoresc ; 30(6): 1365-1374, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32897496

RESUMO

Two new Zn(II)-based coordination polymers {[Zn3(L1)6(H2O)]∙(H2O)4}n (1, HL1 = 4-(tetrazol-5-yl)phenyl-4,2':6',4″-terpyridine) and [Zn2Cl2(L2)2H2O]n (2, HL2 = 4-([2,2':6',2″'-terpyridin]-4'-yl)benzoic acid) have been successfully prepared using two similar organic ligands with distinct donor groups under similar reaction conditions. The distinct structural features and donor atoms make the two complexes show different water stability, and the complex 1 with good water stability, which can be utilized as the sensor for Fe3+ ion detection in water. The value of Stern-Volmer quenching constant of 1 to the Fe3+ is 5.77 × 104 M- 1, which lies in the top region of the reported CP-based sensors. The mechanism investigation reveals that the energy transfer of resonance from the complex 1 to the Fe3+ ion can account for its fluorescent quenching behavior. The treatment activity of compounds 1 and 2 on the postpartum hemorrhage (PPH) was assessed. First, the cytotoxicity of compounds 1 and 2 on human umbilical vein endothelial cells was assessed with Cell Counting Kit-8 detection kit. Then, to evaluate the prevention of compounds 1 and 2 on the PPH, we conducted the Lowry method and detected the clotting factor IX and anticoagulant factor III contents after the indicated treatment. Finally, the inflammatory response in mice was determined by ELISA method, and the IL-6 and IL-8 levels were determined.


Assuntos
Anticoagulantes/química , Anticoagulantes/farmacologia , Ferro/química , Polímeros/química , Hemorragia Pós-Parto/prevenção & controle , Zinco/química , Ácido Benzoico/química , Estabilidade de Medicamentos , Fibrinogênio/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Ligantes , Hemorragia Pós-Parto/metabolismo , Água/química
9.
Cancer Biomark ; 26(1): 21-30, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31322544

RESUMO

BACKGROUND: Golgi phosphoprotein 3 (GOLPH3) is a novel oncogene overexpressed in several human cancers, but specific contributions to endometrial carcinoma (EC) have not been examined. The aims of this study were to evaluate the GOLPH3 expression in EC and investigate its functions in EC cell proliferation, migration, and survival. METHODS: The expression levels of GOLPH3 in EC patient samples and EC cell lines (HEC-1A, KLE, RL95-2, and Ishikawa) were examined using qRT-PCR, western blotting and immunohistochemistry. Further, EC cell lines with either ectopic GOLPH3 overexpression or knockdown were established, and the effects on proliferation, apoptosis, invasion, and migration were investigated in vitro using cell viability and transwell assays and in mice following cell injection. RESULTS: Compared to adjacent non-cancerous tissues, expression of GOLPH3 was significantly upregulated in EC tissues (P< 0.05), and the expression level of GOPLPH3 was related to the grade of the tumor (P< 0.05). The expression of GOLPH3 was also higher in all four EC cell lines than endometrial stromal cells (ESCs) (P< 0.05). Moreover, GOLPH3 expression was greater in EC cell lines with high invasive capacity than in non-invasive EC cells (P< 0.05). Knockdown of GOLPH3 inhibited EC cell proliferation and increased cell apoptosis in vitro. Further, knockdown of GOLPH3 also inhibited EC cell invasion and migration in vitro and in vivo by regulating the epithelial-mesenchymal transition (EMT). Conversely, GOLPH3 overexpression promoted proliferation and migration. CONCLUSIONS: The present study provides evidence that GOLPH3 promotes EMT and metastasis of EC cells and predicts the risk of EC progression, highlighting its potential as a therapeutic target for this malignancy.


Assuntos
Neoplasias do Endométrio/metabolismo , Proteínas de Membrana/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Transição Epitelial-Mesenquimal , Feminino , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Transfecção
10.
Nanoscale Res Lett ; 11(1): 440, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27709561

RESUMO

In this study, a facile one-step synthesis of a novel nanocomposite catalytic film was developed based on silver nanoparticles (AgNPs) immobilized in tannic acid-modified eggshell membrane (Tan-ESM). Tannic acid, as a typical plant polyphenol from oak wood, was first grafted onto ESM fibers to serve as both the reductant and the stabilizer during the synthesis of AgNPs. The morphology, constitution, and thermal stability of the resulting AgNPs@Tan-ESM composites were fully characterized to explain the excellent catalytic efficiency of AgNPs@Tan-ESM composites. These composite catalysts were applied to the degradation of azo dyes which exhibited the high catalytic activity toward Congo red and methyl orange according to the kinetic curves. More importantly, they can be easily recovered and reused for many times because of their good stability.

11.
Molecules ; 21(4): 402, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-27023498

RESUMO

A series of oleanolic acid derivatives were synthesized by diverse reactions, including the introduction of conjugated alkadiene and epoxy ring moieties formed by means of photosensitized oxidation. Eosin Y was used as photosensitizer during this process. Next the cytotoxicity of the products was evaluated on HepG2.2.15 cells to determine the appropriate treatment concentration for the subsequent experiments. Most of the OA derivatives exhibited anti-HBV antigens secretion activity in HepG2.2.15 cells. Among the tested compounds, OA-4 (3.13 µg/mL) showed significant activity against the secretion of HBsAg, HBeAg, and HBV DNA replication with inhibitory ratios of 90.52% ± 1.78%, 31.55% ± 3.65%, and 94.57% ± 3.11% after 6 days, respectively. Besides, OA-4 was further investigated in a duck model with DHBV infection. When OA-4 was administered at a dosage of 500 mg/kg, the results revealed a significant inhibitory effects of DHBV at 19.94% ± 2.87%, 28.80% ± 3.62% and 29.25% ± 2.65% at days 5, 10, and 3 after the cessation of OA-4 treatment, respectively. It's worth noting that OA-4 is superior to lamivudine in the inhibition of rebound of viral replication rate. The structure-activity relationships of OA derivatives had been preliminary discussed, which should be useful to explore further novel anti-HBV agents.


Assuntos
Antivirais/administração & dosagem , Hepatite B/tratamento farmacológico , Ácido Oleanólico/administração & dosagem , Ácido Oleanólico/síntese química , Animais , Antivirais/síntese química , Antivirais/química , Patos/virologia , Células Hep G2 , Hepatite B/virologia , Antígenos E da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/patogenicidade , Humanos , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
12.
Molecules ; 20(3): 4307-18, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25808146

RESUMO

There has been no remarkable progress in the synthesis of sultones in recent years. To facilitate more detailed studies of this functional group, we found a new method to synthesize the sulfonic acid lactone derivatives and finish its ring-closing reaction. A new sultone derivative, (E)-ethyl 4-oxo-6-styryl-3,4-dihydro-1,2-oxathiine-5-carboxylate 2,2-dioxide (S-CA), was synthesized and structurally identified by 1H-NMR, 13C-NMR, HMQC and X-ray single crystal diffraction analysis. The new rapid synthesis extended the method of ring-closing reaction of sulfonic acid lactone derivatives. The angiogenesis activities of S-CA were evaluated by the chick chorioallantoic membrane (CAM) model. It could selectively suppress small angiogenesis in CAM, without influencing either middle and large angiogenesis. In addition, anticancer efficacy of S-CA was evaluated in vivo using a murine sarcoma S180 model. Reduction of the tumor weight and tumor HE staining regions demonstrated that S-CA (10 mg/kg, intraperitoneal injection) had potent inhibition effects and a 44.71% inhibitory rate in S180 mice. Moreover, an acute toxicity test showed that the LD50 value of S-CA via intraperitoneal injection was 25.624 mg/kg.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/síntese química , Antineoplásicos/administração & dosagem , Antineoplásicos/síntese química , Oxati-Inas/administração & dosagem , Oxati-Inas/síntese química , Inibidores da Angiogênese/efeitos adversos , Animais , Antineoplásicos/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Linhagem Celular Tumoral , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Relação Dose-Resposta a Droga , Injeções Intraperitoneais , Camundongos , Estrutura Molecular , Transplante de Neoplasias , Oxati-Inas/efeitos adversos , Sarcoma/tratamento farmacológico
13.
ACS Appl Mater Interfaces ; 6(7): 4638-49, 2014 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-24624939

RESUMO

Facile, efficient, and robust immobilization of metal nanostructures on porous bioscaffolds is an interesting topic in materials chemistry and heterogeneous catalysis. This study reports a facile in situ method for the synthesis and immobilization of small silver nanoparticles (AgNPs) at room temperature on natural eggshell membrane (ESM), which presents interwoven fibrous structure and can be used as a unique protein-based biotemplate. Procyanidin (Pro), a typical plant polyphenol extracted from grape seeds and skins, was first grafted onto ESM fibers to serve as both reductant and stabilizer during the synthesis process. As a result, the AgNPs were facilely synthesized and robustly immobilized on the ESM fibers without additional chemical reductant or physical treatments. The morphology and microstructure of the as-prepared AgNPs@Pro-ESM composites were characterized by combined microscopy and spectroscopy technologies. The results indicate that small AgNPs with mean diameter of 2.46 nm were successfully prepared on the Pro-ESM biotemplate. The composites exhibited good catalytic activity toward the reduction of 4-nitrophenol (4-NP). More importantly, these composite catalysts can be easily recovered and reused for more than eight cycles because of their high stability.


Assuntos
Biflavonoides/química , Catequina/química , Membrana Celular/química , Nanopartículas Metálicas/química , Óvulo/química , Polímeros/química , Proantocianidinas/química , Prata/química , Animais , Catálise , Galinhas , Nitrofenóis/química , Oxirredução , Tamanho da Partícula , Polímeros/síntese química
14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(12): 3277-80, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25881423

RESUMO

In this paper, total of 5170 flue-cured tobacco samples collected from 2003 to 2012 in the domestic and foreign origin by Shanghai Tobacco Group Technical Center were tested by near infrared spectroscopy, including the typical upper leaves 1394, central 2550, the lower part of 1226. Using projection model of based on principal component and Fisher criterion (PPF), follow the projected results to get no statistically significant differences at adjacent principal components, and the number of principal components as little as possible, in this paper, four main components to build projection analysis model, the model results show that: the near-infrared spectral characteristics of the upper and lower leaves have a significant difference that can be achieved almost entirely distinguished; while the middle leaves with upper and lower have a certain degree of overlap, which is consistent to the actual situation of the continuity of tobacco leaf. At the same time, Euclidean distance between the predicted sample projection values and the mean projection values of each class in the model, a description is given for the prediction samples to quantify the extent of the site features, and its first and second close categories. Using the dispersion of projected values in model and the given threshold value, prediction results can be refined into typically upper, upper to central, central to upper, typical central, central to the lower, the lower to central, typically the lower, or super-model range. The model was validated by 34 tobacco samples obtained from the re-drying process in 2012 with different origins and parts. This kind of analysis methods, not only can achieve discriminant analysis, and get richer feature attribute information, can provide guidance on the raw tobacco processing and formulations.


Assuntos
Nicotiana , Espectroscopia de Luz Próxima ao Infravermelho , China , Análise Discriminante , Modelos Teóricos , Folhas de Planta , Análise de Componente Principal
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(10): 2758-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25739221

RESUMO

In the present paper, six categories of standard industrial grading tobacco provided by Hongta Group are taken as experimental samples, including three different tobacco locations-upper (B), middle(C) and lower(X) parts, with each part containing two kinds of tobacco colors-orange (O) and lemon yellow (L). Two methods including projection model method based on principal component and Fisher criterion (PPF) and support vector machine (SVM) method are used to analyze color and location features of tobacco based on visible-near infrared hyperspectral data. The results of projection model method indicate that in the projection and similarity analysis of tobacco color, location and six tobacco groups classified by color and location, two kinds of color can be fully differentiated, of which the similarity value is -1.000 8. Tobacco from upper and lower parts can also be fully differentiated with similarity value 0.405 3, but they both have intersections with tobac- co from middle part. Six tobacco groups classified by color and location can be fully differentiated as well and their projection positions meet the actual external features of tobacco. The results of support vector machine method indicate that in the discriminant analysis of tobacco color, location and six tobacco groups classified by color and location, the average recognition rate of tobacco colors reaches 98%. The average recognition rate of tobacco location is 96%. The average recognition rate of six tobacco groups is 94%. Therefore, it's feasible to analyze color and location features of tobacco using visible-near infrared hyperspectral data, which can provide reference for tobacco quality evaluation, computer-aided grading and tobacco intelligent acquisition, and also offers a new approach to the analysis of exterior features of other agricultural products.


Assuntos
Cor , Nicotiana/classificação , Espectroscopia de Luz Próxima ao Infravermelho , Modelos Teóricos , Máquina de Vetores de Suporte
16.
Food Chem ; 138(2-3): 1596-603, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411286

RESUMO

The interaction of procyanidins with proteins has aroused extensive attention due to its important relationship with the bioavailability and astringent property of polyphenols. In the present work, we have investigated the interactions of lysozyme with procyanidin dimer (B3) using various biophysical approaches, which aims to provide insights into the mechanism of protein/polyphenol aggregation. Procyanidin B3 spontaneously binds lysozyme, inducing the multilevel structural changes in lysozyme and the formation of insoluble complexes. The relationship between lysozyme aggregation and the loss of enzymatic activity was monitored using dynamic light scattering and fluorescence quenching. The influences of two carbohydrates (gum arabic and sucrose) on lysozyme/B3 aggregation were also studied. Gum arabic effectively inhibited the formation of insoluble aggregates, but was unable to restore the fluorescence and activity of lysozyme. However, sucrose concomitantly decreased the aggregate size with the recovery of fluorescence and lysozyme activity. These results proposed two probable mechanisms by which these two carbohydrates inhibit protein/polyphenol aggregation.


Assuntos
Biflavonoides/química , Carboidratos/química , Catequina/química , Muramidase/química , Proantocianidinas/química , Animais , Galinhas , Modelos Moleculares , Ligação Proteica , Estrutura Secundária de Proteína , Espectrometria de Fluorescência
17.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 22(5): 585-7, 2006 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-16948901

RESUMO

AIM: To study the effect of quercetin on the growth and apoptosis of human gastric carcinoma cell line MGC-803. METHODS: The measurement of inhibitory rate and apoptotic index(AI) of quercetin were done by MTT assay and TUNEL assay. The positive expression rate of P53, C-myc and P16 were detected by immunocytochemical staining. RESULTS: Quercetin at concentrations ranging from 40 mumol/L to 100 mumol/L significantly inhibited the proliferation of MGC-803 cells in a dose- and time-dependent manner (P<0.01). TUNEL assay indicated that the number of apoptotic cells in quercetin-treated group was greater than that in the control group (P<0.01). Expression of P53 and C-myc protein decreased following quercetin induction in a dose-dependent manner, whereas P16 expression increased significantly compared with that of the control group (P<0.01). CONCLUSION: Quercetin can inhibit the growth and induce apoptosis of MGC-803 cells in a dose- and time-dependent manner. Its mechanisms may be relevant to the down-regulation of P53 and C-myc protein expression as well as up-regulation of P16 expression.


Assuntos
Apoptose/efeitos dos fármacos , Quercetina/farmacologia , Neoplasias Gástricas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos
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