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1.
Bioorg Med Chem Lett ; 92: 129393, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37369332

RESUMO

Nicotinamide phosphoribosyltransferase (NAMPT) has emerged as a promising target for cancer therapy due to its strong correlation with nicotinamide adenine dinucleotide (NAD+) metabolism and tumorigenesis. Proteolysis targeting chimeras (PROTACs) provided an attractive strategy for developing NAMPT-targeting NAD+-depleting cancer drugs. Herein, a series of von Hippel-Lindau (VHL)-recruiting NAMPT-targeting PROTACs were designed using NAMPT inhibitor FK866 as the warhead. Among them, compound C5 degraded NAMPT (DC50 = 31.7 nM) in a VHL- and proteasome-dependent manner. Moreover, compound C5 effectively inhibited the proliferation of A2780 cells (IC50 = 30.6 nM) and significantly reduced the general cytotoxicity of FK866 to normal cells.


Assuntos
Nicotinamida Fosforribosiltransferase , Neoplasias Ovarianas , Quimera de Direcionamento de Proteólise , Feminino , Humanos , Linhagem Celular Tumoral , Citocinas/metabolismo , NAD/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Proteólise , Quimera de Direcionamento de Proteólise/química
2.
Arch Biochem Biophys ; 668: 39-45, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-31100219

RESUMO

The Fenton-like reaction of iron(II)-citrate with hydrogen peroxide is physiologically important because it is associated with the oxidative stress and pathological processes induced by the redox-active iron pool in vivo. However, the oxidizing species generated from this reaction at neutral pH has not been convincingly identified because two extremely unstable and hard-to-differentiate species, the hydroxyl radical (•OH) and iron(IV) (ferryl) species, can be produced. Identifying this species is essential for understanding the reaction mechanism. Although there were few data that reported the detection of •OH from this reaction by using the EPR and fluorescence techniques, most of these data were obtained without the necessary assessment with a •OH scavenger. Furthermore, these two techniques may not be able to differentiate the •OH and iron(IV) species. Thus, these reported data cannot lead to a convincing conclusion that the •OH, not the iron(IV) species, was generated. Therefore, in the study reported herein, we carried out systematic investigations first by using the EPR and fluorescence techniques combined with a •OH scavenger to detect the oxidizing species generated from this Fenton-like reaction. Then we utilized NMR spectroscopy and for the first time obtained convincing evidence to demonstrate that this oxidizing species is the •OH rather than iron(IV) species. We also determined the second-order rate constant of the reaction, 3.6 × 103 M-1s-1 (pH7.0, 25 °C), by using the stopped-flow spectrophotometry. On the basis of these findings, a scheme is proposed for the mechanism of this physiologically important Fenton-like reaction.


Assuntos
Compostos Ferrosos/química , Peróxido de Hidrogênio/química , Radical Hidroxila/análise , Ácido Cítrico , Espectroscopia de Ressonância de Spin Eletrônica , Cinética , Modelos Químicos , Oxirredução , Espectrofotometria
3.
Biochem Biophys Res Commun ; 483(1): 159-164, 2017 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-28042034

RESUMO

In vivo physiological ligand citrate can bind iron(II) ions to form the iron(II)-citrate complex. Inhibition of hydroxyl radical (OH) production from the Fenton-like reaction of iron(II)-citrate with H2O2 is biologically important, as this reaction may account for one of the mechanisms of the labile iron pool in vivo to induce oxidative stress and pathological conditions. Nitroxides have promising potentials as therapeutic antioxidants. However, there are controversial findings indicating that they not only act as antioxidants but also as pro-oxidants when engaged in Fenton reactions. Although the underlying mechanisms are proposed to be the inhibition or enhancement of the OH production by nitroxides, the proposed elucidations are only based on assessing biological damages and not demonstrated directly by measuring the OH production in the presence of nitroxides. In this study, therefore, we employed EPR and fluorescence spectroscopies to show direct evidence that nitroxide 2,2,6,6-tetramethyl-piperidine-1-oxyl (Tempo) inhibited OH production from the Fenton-like reaction of iron(II)-citrate with H2O2 by up to 90%. We also demonstrated spectrophotometrically, for the first time, that this inhibition was due to oxidation of the iron(II)-citrate by Tempo with a stoichiometry of Tempo:Iron(III)-citrate = 1.1:1.0. A scheme was proposed to illustrate the roles of nitroxides engaged in Fenton/Fenton-like reactions.


Assuntos
Citratos/química , Óxidos N-Cíclicos/química , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Ferro/química , Espectroscopia de Ressonância de Spin Eletrônica , Compostos Ferrosos/química , Radical Hidroxila/metabolismo , Oxirredução , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
4.
Artigo em Inglês | MEDLINE | ID: mdl-38277248

RESUMO

Federated learning (FL) makes it possible for multiple clients to collaboratively train a machine-learning model through communicating models instead of data, reducing privacy risk. Thus, FL is more suitable for processing data security and privacy for intelligent systems and applications. Unfortunately, there are several challenges in FL, such as the low training accuracy for nonindependent and identically distributed (non-IID) data and the high cost of computation and communication. Considering these, we propose a novel FL framework named dynamic sparse federated contrastive learning (DSFedCon). DSFedCon combines FL with dynamic sparse (DSR) training of network pruning and contrastive learning to improve model performance and reduce computation costs and communication costs. We analyze DSFedCon from the perspective of accuracy, communication, and security, demonstrating it is communication-efficient and safe. To give a practical evaluation for non-IID data training, we perform experiments and comparisons on the MNIST, CIFAR-10, and CIFAR-100 datasets with different parameters of Dirichlet distribution. Results indicate that DSFedCon can get higher accuracy and better communication cost than other state-of-the-art methods in these two datasets. More precisely, we show that DSFedCon has a 4.67-time speedup of communication rounds in MNIST, a 7.5-time speedup of communication rounds in CIFAR-10, and an 18.33-time speedup of communication rounds in CIFAR-100 dataset while achieving the same training accuracy.

5.
Neurogastroenterol Motil ; : e14875, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39077771

RESUMO

BACKGROUND: The traditional herbal medicine Atractylodes macrocephala Koidz. (A. macrocephala) is commonly utilized for alleviating symptoms associated with spleen deficiency, abdominal distension, diarrhea, and constipation. These pharmacological effects are attributed to a variety of active constituents. However, the specific bioactive compounds responsible for promoting defecation and gastrointestinal transit in A. macrocephala remain unidentified. METHODS: The primary polysaccharide characteristics of PAMK was elucidated by HPLC, FT-IR, and HGPGC. Efficacy of PAMK (0.07, 0.14, and 0.28 mg/g) on mice was evaluated in a spleen deficiency constipation mouse model by analyzing stool parameters, constipation-related physiological indexes, and SCFAs. The expression levels of 5-HT3R, 5-HT4R, and related receptor genes were examined by RT-qPCR, and neurotransmitters were examined using ELISA. Finally, the diversity of gut microbiota was analyzed with 16S rDNA sequencing. KEY RESULTS: The results showed that PAMK significantly reduced the gastrointestinal transport time and increased the number of fecal pellets and fecal water content in spleen deficiency constipation model mice. PAMK kept the balance of 5-HT, SCFAs, TPH-1, SERT, CgA, and neurotransmitter levels (VIP, SP, MTL) in mice colon. In addition, PAMK could regulate the abundance of gut microbiota such as Alistopes, Bacteroides, and Odoribacter in spleen deficiency constipation model mice gut. CONCLUSIONS AND INFERENCES: It can be concluded that PAMK effectively ameliorated the symptoms of spleen deficiency constipation in mice by modulating the expression of 5-HT and its associated receptors. The underlying mechanism was elucidated, providing a solid theoretical foundation for the therapeutic application of A. macrocephala in treating spleen deficiency constipation and offering potential for developing novel approaches to address this condition.

6.
Eur J Med Chem ; 264: 116047, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38118394

RESUMO

Hepatocellular carcinoma (HCC) is a highly aggressive and lethal malignancy with poor prognosis, necessitating the urgent development of effective treatments. Targeted photodynamic therapy (PDT) offers a promising way to selectively eradicate tumor cells without affecting normal cells. Inspired by promising features of peptide-drug conjugates (PDCs) in targeted cancer therapy, herein a novel glypican-3 (GPC3)-targeting PDC-PDT strategy was developed for the precise PDT treatment of HCC. The GPC3-targeting photosensitizer conjugates were developed by attaching GPC3-targeting peptides to chlorin e6. Conjugate 8b demonstrated the ability to penetrate HCC cells via GPC3-mediated entry process, exhibiting remarkable tumor-targeting capacity, superior antitumor efficacy, and minimal toxicity towards normal cells. Notably, conjugate 8b achieved complete tumor elimination upon light illumination in a HepG2 xenograft model without harm to normal tissues. Overall, this innovative GPC3-targeting conjugation strategy demonstrates considerable promise for clinical applications for the treatment of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Fotoquimioterapia , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Glipicanas/uso terapêutico , Peptídeos/farmacologia , Peptídeos/uso terapêutico
7.
BMC Neurol ; 13: 134, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-24088363

RESUMO

BACKGROUND: The clinical profiles of cerebellar cavernous malformations (CCMs) with and without associated developmental venous anomalies (DVAs) are not well known. The aims of this study were to analyze the clinical and radiological characteristics of CCMs and to assess the various therapeutic strategies. METHODS: A consecutive series of 41 patients with identified CCMs were retrospectively reviewed. Of these, 11 patients (26.8%) were found to have associated DVAs. We compared the clinical profile of the two groups of patients (CCMs with and without DVAs). The CCMs with DVAs cases underwent radical resection of the CCMs, and the distal radicles of the DVAs that directly drain from the CCMs were coagulated and dissected at the length of the CCMs. RESULTS: There were no statistically significant differences between the two groups with regard to age, sex, location and size of lesions, multiplicity, and surgical prognosis. The patients with CCMs with DVAs did not experience any brain swelling or hemorrhagic tendency intraoperatively. The postoperative course was uneventful for all of the 36 surgical patients with the exception of two of the patients with CCMs with associated DVAs, who suffered from serious cerebellar edema, and one of these two patients underwent an emergency suboccipital decompression craniotomy. With the exception of three patients who were lost to follow-up (mean, 22.3 months), all of the CCMs patients exhibited good long-term prognosis (modified Rankin scale values of 0-2) and no reoccurrence. CONCLUSIONS: It is not rare that associated DVAs occur in CCMs. The total removal of the CCM combined with the coagulation and dissection of the distal radicles of DVA at the length of the associated CCM may result in good long-term prognosis in patients.


Assuntos
Neoplasias do Sistema Nervoso Central/complicações , Veias Cerebrais/anormalidades , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Adolescente , Adulto , Idoso , Análise de Variância , Angiografia Digital , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Neoplasias do Sistema Nervoso Central/cirurgia , Veias Cerebrais/cirurgia , Criança , Pré-Escolar , Feminino , Seguimentos , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomógrafos Computadorizados , Adulto Jovem
8.
J Med Chem ; 66(24): 16828-16842, 2023 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-38055861

RESUMO

Proteolysis-targeting chimeras (PROTACs) have recently emerged as a promising technology for drug development. However, poor water solubility, limited tissue selectivity, and inadequate tumor penetration pose significant challenges for PROTAC-based therapies in cancer treatment. Herein, we developed an iRGD-PROTAC conjugation strategy utilizing tumor-penetrating cyclic peptide iRGD (CRGDK/RGPD/EC) to deliver PROTACs deep into breast cancer tissues. As a conceptual validation study, iRGD peptides were conjugated with a bromodomain-containing protein 4 (BRD4) PROTAC through a GSH-responsive linker. The resulting iRGD-PROTAC conjugate iPR showed enhanced water solubility, tumor-targeting capability, and penetration within tumor tissues, resulting in increased antibreast cancer efficacy in animal models and patient-derived organoids. This study demonstrates the advantages of combining iRGD and PROTACs in improving drug delivery and highlights the importance of tissue selectivity and penetration ability in PROTAC-based therapeutics.


Assuntos
Neoplasias da Mama , Animais , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Proteólise , Quimera de Direcionamento de Proteólise , Proteínas Nucleares , Linhagem Celular Tumoral , Fatores de Transcrição , Água , Proteínas que Contêm Bromodomínio , Proteínas de Ciclo Celular
9.
Sci Total Environ ; 848: 157674, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35926603

RESUMO

Disinfection byproducts (DBPs) are initially formed in the process of chlorination in the drinking water treatment plants (DWTPs), then further formed in the distribution system due to the presence of residual chlorine and reactive organic matters. However, in China, DBPs are monitored in the effluent from the DWTPs, but less is known about concentrations of DBPs in tap water since they are usually monitored once per half a year. The smart water service system is establishing real-time monitoring of water indices, although DBPs are an urgent need, they are difficult to monitor in real-time due to their diversity and complicated detection methods. If the correlation between DBP concentration and routinely real-time monitored water quality parameters (e.g., pH value, residual chlorine, ammonia) can be evaluated, the concentration of DBPs can be predicted, which will strengthen the control of tap water safety. This article comprehensively assessed the physicochemical parameters and the occurrence of DBP formation in the tap water with an 18-month investigation in Z city (China). DBP formation in tap water of different seasons and different water sources were compared. Based on the relationship between DBPs and physicochemical parameters, linear prediction and nonlinear prediction models of trihalomethanes (THMs), haloacetonitriles (HANs) and haloacetic acids (HAAs) were established, and the accuracy of these models was verified by measured data. Finally, the toxicity and carcinogenic and non-carcinogenic health risk assessment of DBPs in tap water were analyzed.


Assuntos
Desinfetantes , Água Potável , Poluentes Químicos da Água , Purificação da Água , Amônia , China , Cloro , Desinfetantes/análise , Desinfecção/métodos , Halogenação , Humanos , Trialometanos/análise , Poluentes Químicos da Água/análise
10.
Environ Pollut ; 283: 117325, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34030065

RESUMO

Fish embryos, as an endogenous system, strictly regulate an energy metabolism that is particularly sensitive to environmental pressure. This study used orange-spotted grouper embryos and stable isotope 67Zn to test the hypothesis that waterborne Zn exposure had a significant effect on energy metabolism in embryos. The fish embryos were exposed to a gradient level of waterborne 67Zn, and then sampled to quantify 67Zn bioaccumulation and mRNA expressions of key genes involved glucose metabolism. The results indicated that the bioaccumulated 67Zn generally increased with increasing waterborne 67Zn concentrations, while it tended to be saturated at waterborne 67Zn > 0.7 mg L-1. As we hypothesized, the expression of PK and PFK gene involved glycolysis pathway was significantly up-regulated under waterborne 67Zn exposure >4 mg L-1. Waterborne 67Zn exposure >2 mg L-1 significantly suppressed PCK and G6PC gene expression involved gluconeogenesis pathway, and also inhibited the AKT2, GSK-3beta and GLUT4 genes involved Akt signaling pathway. Our findings first characterized developmental stage-dependent Zn uptake and genotoxicity in fish embryos. We suggest fish embryos, as a small-scale modeling biosystem, have a large potential and wide applicability for determining cytotoxicity/genotoxicity of waterborne metal in aquatic ecosystem.


Assuntos
Bass , Zinco , Animais , Bioacumulação , Ecossistema , Glucose , Glicogênio Sintase Quinase 3 beta , Zinco/toxicidade
11.
Int J Biol Macromol ; 190: 649-659, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517026

RESUMO

Atractylodes macrocephala Koidz. (AM), an herb of traditional Chinese medicine, is well-known for anti-oxidant, anti-tumor and immune regulation potential. However, it is low bioactive compound content that restricts the application of this species. Elicitation is considered as an effective method to enhance biomass and bioactive compound in plants. Our precious study found that polysaccharide of Chrysanthemun indicum L. could promote plant growth by triggering plant defense. In the present study, polysaccharide of Chrysanthemun indicum L. is used to stimulate the accumulation of biomass and bioactive compound with different concentration in Atractylodes macrocephala Koidz. during pot, plot and field experiments. The results suggested that polysaccharide of Chrysanthemun indicum L. could significantly enhance the accumulation of biomass, atractylenolides and polysacchrides. Moreover, 2 mg/mL is determined and verified to be the appropriate concentration during field experiments. In addition, RT-qPCR revealed that CIP-induced terpenoid synthesis in AM mainly depended on mevalonate (MVA) pathway. This is the first report on the discovery of polysaccharide of Chrysanthemun indicum L. for the enhanced accumulation of biaomass and bioactive compound and the use of its for agricultural production.


Assuntos
Atractylodes/metabolismo , Chrysanthemum/química , Polissacarídeos/farmacologia , Sesquiterpenos/metabolismo , Antioxidantes/farmacologia , Atractylodes/efeitos dos fármacos , Atractylodes/genética , Biomassa , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
12.
J Plant Physiol ; 245: 153107, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31881440

RESUMO

Plant-derived elicitor is a new type of plant vaccine developed in the contemporary era, and it has safe and broad application prospects in organic agriculture. Research on defense mechanisms triggered by elicitor has become a hot topic in recent years. The Chrysanthemum indicum polysaccharide (CIP) obtained by separation and purification from Chrysanthemum indicum was used as an elicitor in this work. This elicitor has been shown to be effective in Atractylodes macrocephala Koidz (A. macrocephala) against Sclerotium rolfsii sacc (S. rolfsii) infection and soil-borne diseases. However, the mechanism of induced disease resistance has not been elucidated. In this research, we study the CIP-induced A. macrocephala defense response from the level of signal molecules and the defensive enzyme gene expression. Several defense responses to CIP treatment have been found in A. macrocephala, including early hydrogen peroxide (H2O2) production, accumulation of salicylic acid (SA) and increased phytoalexin (PA) content. In addition, CIP significantly increased the activity of related defense enzymes in A. macrocephala. RT-qPCR analysis showed that defense-related genes such as polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were up-regulated after CIP treatment. To obtain the sequence of the defense enzyme gene, we are the first to provide a public and comprehensive A. macrocephala database by transcriptome sequencing. These results together demonstrate that CIP triggers defense responses in A. macrocephala. Our research not only provides further research on immune mechanism between plant and elicitor, but also sheds new light on strategy for biocontrol in the future.


Assuntos
Atractylodes/metabolismo , Chrysanthemum/metabolismo , Resistência à Doença/efeitos dos fármacos , Polissacarídeos/farmacologia , Transcriptoma/efeitos dos fármacos , Atractylodes/efeitos dos fármacos , Atractylodes/genética , Atractylodes/microbiologia , Basidiomycota , Catecol Oxidase/efeitos dos fármacos , Catecol Oxidase/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Peróxido de Hidrogênio/metabolismo , Fenilalanina Amônia-Liase/efeitos dos fármacos , Fenilalanina Amônia-Liase/metabolismo , Imunidade Vegetal/efeitos dos fármacos , Folhas de Planta/metabolismo , Polissacarídeos/isolamento & purificação , Ácido Salicílico/metabolismo , Sesquiterpenos/metabolismo , Fitoalexinas
13.
Carbohydr Polym ; 230: 115637, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887887

RESUMO

Some carbohydrate polymers, usually oligosaccharides or polysaccharides, have great potential as an elicitor of plant defense. However, due to the complexity and diversity of poly- and oligosaccharide structure, the molecular mechanisms and structure-activity relationships of carbohydrate elicitors are still not well understood, which hinders the application of carbohydrate elicitors in agriculture. This review introduces the mechanisms of carbohydrate elicitor perception and signaling in plants. The structure and activity relationships of main poly- and oligosaccharides studied for the control of plant diseases are discussed and summarized. Additionally, the effects of carbohydrate elicitors on the secondary metabolite production are also summarized.

14.
Int J Biol Macromol ; 162: 1217-1226, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32574735

RESUMO

The purpose of this study was to identify and determine the physical and structural characterization of the water-soluble galactomannan extracted from endosperm splits of Chinese S. cannabina seeds. The Sesbania galactomannan (SP) was extracted and purified using a novel method with a high yield (40.3 ± 7.2%). The molecular structure of SP was determined by monosaccharide composition, FTIR and NMR spectroscopy. The structural data showed that SP was galactomannan which composed by a ß-(1/4)-linked mannose backbone with galactopyranosyl residues attached through α-(1/6) linkages. The constant mannose/galactose (M/G) ratio and average molecular weight (Mw) of SP was 1.6:1 and 2.16 × 105 g/mol, respectively. The physical results revealed that SP had many branches on the backbone and existed as a random coil state in aqueous solution. SP was a good biopolymer which had smooth and clearer surface with homogeneous composition, and had some degree of crystallinity and prebiotic activity. As a consequence, SP could be a potential prebiotic and was expected to be suitable for applications in food, pharmaceutical, biomedical or cosmetic industries as a promising new biomaterial.


Assuntos
Endosperma/química , Mananas/química , Mananas/isolamento & purificação , Prebióticos , Sesbania/química , Galactose/análogos & derivados
15.
World Neurosurg ; 129: e429-e435, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150855

RESUMO

OBJECTIVE: To evaluate the 30-day outcomes of using the Enterprise stent to treat patients with hypoperfusion of symptomatic severe intracranial stenosis. METHODS: Patients with symptomatic severe intracranial stenosis (70%-99%) who underwent Enterprise stent intervention between August 2014 and November 2018 were retrospectively analyzed. The 30-day primary outcomes included the success rate of stenting and the incidence of complications, including ischemic stroke, cerebral hemorrhage, and death. The 30-day complication rates of patients with different lesion locations and classifications of Mori morphology were compared. RESULTS: Sixty-eight patients were treated using 70 Enterprise stents. The success rate was 100%. The 30-day complication rate was 4.4%. The rates of ischemic stroke, cerebral hemorrhage, and death were 1.5%, 2.9%, and 0%, respectively. No significant difference was found in the 30-day complication rate between patients with different lesion locations and classifications of Mori morphology (P > 0.05). CONCLUSION: Enterprise stents were relatively safe in treating patients with hypoperfusion of symptomatic severe intracranial stenosis.


Assuntos
Arteriopatias Oclusivas/cirurgia , Isquemia Encefálica/etiologia , Hemorragia Cerebral/etiologia , Procedimentos Endovasculares/métodos , Stents , Acidente Vascular Cerebral/etiologia , Idoso , Arteriopatias Oclusivas/complicações , Procedimentos Endovasculares/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Resultado do Tratamento
16.
Carbohydr Polym ; 184: 214-220, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29352914

RESUMO

Non-degradable plastic food packages threaten the security of environment. The cost-effective and biodegradable polymer films with good mechanical properties and low permeability are very important for food packages. Among of biodegradable polymers, PVA/chitosan (CS) biodegradable films have attracted considerable attention because of feasible film forming ability. However, PVA/CS biodegradable films suffered from poor mechanical properties. To improve mechanical properties of PVA/CS biodegradable films, we developed SiO2in situ to enhance PVA/CS biodegradable films via hydrolysis of sodium metasilicate in presence of PVA and chitosan solution. The tensile strength of PVA/CS biodegradable films was improved 45% when 0.6 wt.% SiO2 was incorporated into the films. Weight loss of PVA/CS biodegradable films was 60% after 30 days in the soil. The permeability of oxygen and moisture of PVA/CS biodegradable films was reduced by 25.6% and 10.2%, respectively. SiO2in situ enhanced PVA/CS biodegradable films possessed not only excellent mechanical properties, but also barrier of oxygen and water for food packages to extend the perseveration time.


Assuntos
Quitosana/química , Álcool de Polivinil/química , Dióxido de Silício/química , Embalagem de Alimentos , Concentração de Íons de Hidrogênio , Oxigênio/química , Resistência à Tração
17.
Oncotarget ; 7(21): 31079-87, 2016 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-27145269

RESUMO

This study was to investigate the prognostic role of Ki-67 in further classification of triple negative breast cancer (TNBC), and to test whether high expression level of Ki67 can predict benefit from carboplatin. From January 2004 to December 2012, 363 patients operated for TNBC were identified through the institutional clinical database. After a median follow-up time of 34 months (5.2-120.0 months), 62 patients (17.1%) had relapses and 33 patients (9.1%) died of breast cancer. In univariate analysis, high Ki-67 index as well as larger tumor size and lymph node involvement was associated with shorter disease-free survival (DFS) and overall survival (OS). In multivariate analysis, high Ki-67 is an independent risk factor for DFS (Risk Ratio, RR: 2.835, 95% confidence interval, 95% CI: 1.586-5.068, P < 0.001) and OS (RR: 3.180, 95% CI: 1.488-6.793, P = 0.003). When analyzing the 3-year DFS by Ki-67 distribution, Subpopulation Treatment Effect Pattern Plot analysis showed a beneficial effect of carboplatin in patients with high Ki-67 index. In conclusion, TNBC is probably a heterogeneous disease with different characteristics and prognosis, and may be further subdivided according to the Ki-67 expression levels. Patients in the high Ki- 67 group seem to benefit more from treatment with carboplatin, but this needs to be further verified.


Assuntos
Antígeno Ki-67/biossíntese , Neoplasias de Mama Triplo Negativas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carboplatina/administração & dosagem , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Adulto Jovem
18.
PLoS One ; 10(9): e0137853, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26361016

RESUMO

The evolution and development of the three-dimensional (3D) architectural landscape is the basis of proper urban planning, eco-environment construction and the improvement of environmental quality. This paper presents the spatiotemporal characteristics of the 3D architectural landscape of the Shinan and Shibei districts in Qingdao, China, based on buildings' 3D information extracted from Quickbird images from 2003 to 2012, supported by Barista, landscape metrics and GIS. The results demonstrated that: (1) Shinan and Shibei districts expanded vertically and urban land use intensity increased noticeably from year to year. (2) Significant differences in the 3D architectural landscape existed among the western, central and eastern regions, and among the 26 sub-districts over the study period. The differentiation was consistent with the diverse development history, function and planning of the two districts. Finally, we found that population correlates positively with the variation in the 3D architectural landscape. This research provides an important reference for related studies, urban planning and eco-city construction.


Assuntos
Cidades , Análise Espaço-Temporal , Reforma Urbana , China
19.
Ying Yong Sheng Tai Xue Bao ; 22(2): 453-9, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21608261

RESUMO

Based on the 1:10000 aerial photo in 1997 and the three QuickBird images in 2002, 2005, and 2008, and by using Barista software and GIS and RS techniques, the three-dimensional information of the residential community in Tiexi District of Shenyang was extracted, and the variation pattern of the three-dimensional landscape in the district during its reconstruction in 1997-2008 and related affecting factors were analyzed with the indices, ie. road density, greening rate, average building height, building height standard deviation, building coverage rate, floor area rate, building shape coefficient, population density, and per capita GDP. The results showed that in 1997-2008, the building area for industry decreased, that for commerce and other public affairs increased, and the area for residents, education, and medical cares basically remained stable. The building number, building coverage rate, and building shape coefficient decreased, while the floor area rate, average building height, height standard deviation, road density, and greening rate increased. Within the limited space of residential community, the containing capacity of population and economic activity increased, and the environment quality also improved to some extent. The variation degree of average building height increased, but the building energy consumption decreased. Population growth and economic development had positive correlations with floor area rate, road density, and greening rate, but negative correlation with building coverage rate.


Assuntos
Planejamento de Cidades , Ecossistema , Planejamento Ambiental , Monitoramento Ambiental/métodos , Imageamento Tridimensional , China , Cidades , Sistemas de Informação Geográfica , Comunicações Via Satélite
20.
Ying Yong Sheng Tai Xue Bao ; 21(5): 1190-5, 2010 May.
Artigo em Chinês | MEDLINE | ID: mdl-20707100

RESUMO

The demand for accurate and up-to-date spatial information of urban buildings is becoming more and more important for urban planning, environmental protection, and other vocations. Today's commercial high-resolution satellite imagery offers the potential to extract the three-dimensional information of urban buildings. This paper extracted the three-dimensional information of urban buildings from QuickBird imagery, and validated the precision of the extraction based on Barista software. It was shown that the extraction of three-dimensional information of the buildings from high-resolution satellite imagery based on Barista software had the advantages of low professional level demand, powerful universality, simple operation, and high precision. One pixel level of point positioning and height determination accuracy could be achieved if the digital elevation model (DEM) and sensor orientation model had higher precision and the off-Nadir View Angle was relatively perfect.


Assuntos
Planejamento de Cidades , Arquitetura de Instituições de Saúde , Imageamento Tridimensional , Comunicações Via Satélite , Software , China , Conservação dos Recursos Naturais/métodos
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