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1.
J Colloid Interface Sci ; 658: 90-99, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38100979

RESUMO

The electrochemical properties of corn starch (CS)-based hydrothermal carbon microsphere (CMS) electrode materials for supercapacitor are closely related to their structures. Herein, cetyltrimethyl ammonium bromide (CTAB) was used as a soft template to form the corn starch (CS)-based carbon microspheres with radial hollow structure in the inner and middle layers by hydrothermal and sol-gel method. Due to the introduction of multi-layer hollow structure of carbon microsphere, more micropores were produced during CO2 activation, which increased the specific surface area and improved the capacitance performance. Compared to commercial activated carbon, the four different morphologies of corn starch CMS had better electrochemical performances. Consequently, the proposed CO2-(CTAB)-CS-CS exhibits a high discharge specific capacitance of 242.5F/g at 1 A/g in three-electrode system with 6 M KOH electrolyte, better than commercial activated carbon with 208.5F/g. Moreover, excellent stability is achieved for CO2-(CTAB)-CS-CS with approximately 97.14 % retention of the initial specific capacitance value after 10,000 cycles at a current density of 2 A/g, while the commercial activated carbon has 86.96 % retention. This implies that the corn starch-based multilayer hollow CMS could be a promising electrode material for high-performance supercapacitors.

2.
Metabolomics ; 18(12): 99, 2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-36441416

RESUMO

INTRODUCTION: Previous studies have explored prediction value of serum metabolites in neoadjuvant chemoradiation therapy (NCRT) response for rectal cancer. To date, limited literature is available for serum metabolome changes dynamically through NCRT. OBJECTIVES: This study aimed to explore temporal change pattern of serum metabolites during NCRT, and potential metabolic biomarkers to predict the pathological response to NCRT in locally advanced rectal cancer (LARC) patients. METHODS: Based on dynamic UHPLC-QTOF-MS untargeted metabolomics design, this study included 106 LARC patients treated with NCRT. Biological samples of the enrolled patients were collected in five consecutive time-points. Untargeted metabolomics was used to profile serum metabolic signatures from LARC patients. Then, we used fuzzy C-means clustering (FCM) to explore temporal change patterns in metabolites cluster and identify monotonously changing metabolites during NCRT. Repeated measure analysis of variance (RM-ANOVA) and multilevel partial least-squares discriminant analysis (ML-PLS-DA) were performed to select metabolic biomarkers. Finally, a panel of dynamic differential metabolites was used to build logistic regression prediction models. RESULTS: Metabolite profiles showed a clearly tendency of separation between different follow-up panels. We identified two clusters of 155 serum metabolites with monotonously changing patterns during NCRT (74 decreased metabolites and 81 increased metabolites). Using RM-ANOVA and ML-PLS-DA, 8 metabolites (L-Norleucine, Betaine, Hypoxanthine, Acetylcholine, 1-Hexadecanoyl-sn-glycero-3-phosphocholine, Glycerophosphocholine, Alpha-ketoisovaleric acid, N-Acetyl-L-alanine) were further identified as dynamic differential biomarkers for predicting NCRT sensitivity. The area under the ROC curve (AUC) of prediction model combined with the baseline measurement was 0.54 (95%CI = 0.43 ~ 0.65). By incorporating the variability indexes of 8 dynamic differential metabolites, the prediction model showed better discrimination performance than baseline measurement, with AUC = 0.67 (95%CI 0.57 ~ 0.77), 0.64 (0.53 ~ 0.75), 0.60 (0.50 ~ 0.71), and 0.56 (0.45 ~ 0.67) for the variability index of difference, linear slope, ratio, and standard deviation, respectively. CONCLUSION: This study identified eight metabolites as dynamic differential biomarkers to discriminate NCRT-sensitive and resistant patients. The changes of metabolite level during NCRT show better performance in predicting NCRT sensitivity. These findings highlight the clinical significance of metabolites variabilities in metabolomics analysis.


Assuntos
Terapia Neoadjuvante , Neoplasias Retais , Humanos , Metabolômica , Neoplasias Retais/terapia , Metaboloma , Acetilcolina , Glicerilfosforilcolina
3.
ACS Appl Mater Interfaces ; 14(21): 24497-24508, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35580353

RESUMO

Redox electrolytes for supercapacitors (SCs) have recently sparked widespread interest. Due to the redox reactions within electrolytes, they can achieve high capacitance and long cycle stability. However, the energy density of SCs with redox electrolytes is limited by the narrow applied electrochemical window due to the irreversible side reaction of redox mediators at high potential. To overcome this issue, a redox mediator with a high redox potential, tetrachloridehydroquinone (TCHQ), is added to organic electrolytes to obtain a broad electrochemical window. TCHQ is designed to undergo a dehydrogenation reaction catalyzed by N-doped activated carbon to provide capacitance. The pyrrole N atoms have the highest electrocatalytic activity based on the theoretical calculation of reaction overpotential with predicted reaction pathways due to their Lewis basicity. Benefitting from that, TCHQ shows promising reversibility with a larger electrochemical window (up to 2.7 V). As a result, a higher energy density is obtained when compared to commercial SCs. This study proposes a strategy for designing redox mediators and interfaces of SCs with high energy density and a calculation method of dehydrogenation reaction electrocatalysis.

4.
Br J Radiol ; 91(1092): 20180580, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30160183

RESUMO

OBJECTIVES:: To investigate the use of shortened contrast injection with late triggering in coronary CT angiography (CCTA) for decreasing contrast dose and maintaining image quality. METHODS:: 106 patients for CCTA on a 16-cm wide-detector CT were prospectively enrolled into groups A (n = 50) and B (n = 56) randomly. Patient weight-dependent contrast medium (Iopamiro, 370 mgI ml-1) at dose rate of 25 mgI/kg/s was used with 8 s and the standard 10 s injection time in groups A and B, respectively. CT values of the aortic sinus (AS), right coronary artery, left anterior descending and left circumflex at the proximal, middle and distal segments were measured and compared. Subjective image quality was evaluated and analyzed with Fisher exact test. Contrast dose, injection rate and enhancement duration (between the start of enhancement in AS and scan finish) were also compared. RESULTS:: There was no difference in the injection rate and enhancement duration between the two groups (p > 0.05), while the total contrast dose in group A (36.2 ± 5.7 ml) was significantly lower than in group B (46.4 ± 6.3 ml) (p < 0.001). There was no difference for CT values in all major coronary vessels between the two groups and no difference in subjective image quality scores (all p > 0.05). CONCLUSION:: It is feasible to shorten contrast injection to 8 s in CCTA on wide-detector CT systems to significantly reduce contrast dosage, maintain adequate enhancement and reduce contrast-related artifacts. ADVANCES IN KNOWLEDGE:: (1) Coronary CT angiography (CCTA) scans with shortened contrast medium injection duration and late triggering are feasible with a 16-cm wide-detector CT system (2) Compared with the conventional CCTA with 10 s contrast injection duration, the new contrast injection protocol of using shortened injection duration (to 8 s) and late triggering reduces contrast dose to 36.2 ml, while maintaining adequate enhancement in vessels and reducing contrast-related artifacts.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Iopamidol/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Artefatos , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 867-870, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28268461

RESUMO

Motion classification system based on surface Electromyography (sEMG) pattern recognition has achieved good results in experimental condition. But it is still a challenge for clinical implement and practical application. Many factors contribute to the difficulty of clinical use of the EMG based dexterous control. The most obvious and important is the noise in the EMG signal caused by electrode shift, muscle fatigue, motion artifact, inherent instability of signal and biological signals such as Electrocardiogram. In this paper, a novel method based on Canonical Correlation Analysis (CCA) was developed to eliminate the reduction of classification accuracy caused by electrode shift. The average classification accuracy of our method were above 95% for the healthy subjects. In the process, we validated the influence of electrode shift on motion classification accuracy and discovered the strong correlation with correlation coefficient of >0.9 between shift position data and normal position data.


Assuntos
Algoritmos , Eletromiografia/métodos , Processamento de Sinais Assistido por Computador , Artefatos , Eletrodos , Eletromiografia/instrumentação , Mãos , Humanos , Movimento (Física) , Fadiga Muscular/fisiologia , Punho
6.
J Am Chem Soc ; 135(13): 5068-73, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-23464924

RESUMO

A novel type of cellular-uptake-shielding multifunctional envelope-type mesoporous silica nanoparticle (MEMSN) was designed for tumor-triggered targeting drug delivery to cancerous cells. ß-Cyclodextrin (ß-CD) was anchored on the surface of mesoporous silica nanoparticles via disulfide linking for glutathione-induced intracellular drug release. Then a peptide sequence containing Arg-Gly-Asp (RGD) motif and matrix metalloproteinase (MMP) substrate peptide Pro-Leu-Gly-Val-Arg (PLGVR) was introduced onto the surface of the nanoparticles via host-guest interaction. To protect the targeting ligand and prevent the nanoparticles from being uptaken by normal cells, the nanoparticles were further decorated with poly(aspartic acid) (PASP) to obtain MEMSN. In vitro study demonstrated that MEMSN was shielded against normal cells. After reaching the tumor cells, the targeting property could be switched on by removing the PASP protection layer via hydrolyzation of PLGVR at the MMP-rich tumor cells, which enabled the easy uptake of drug-loaded nanoparticles by tumor cells and subsequent glutathione-induced drug release intracellularly.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Neoplasias/tratamento farmacológico , Dióxido de Silício/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Portadores de Fármacos/síntese química , Humanos , Microscopia Eletrônica de Transmissão , Porosidade
7.
J Mater Sci Mater Med ; 21(10): 2817-25, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20857324

RESUMO

Amphiphilic triblock copolymers monomethoxyl poly(ethylene glycol) (mPEG)-b-poly(ε-caprolactone) (PCL)-b-poly(aminoethyl methacrylate)s (PAMAs) (mPECAs) were synthesized as gene delivery vectors. They exhibited lower cytotoxicity and higher transfection efficiency in COS-7 cells in presence of serum compared to 25 kDa bPEI. The influence of mPEG and PCL segments in mPECAs was evaluated by comparing with corresponding diblock copolymers. The studies showed the incorporation of the hydrophobic PCL segment in triblock copolymers affected the binding capability to pDNA and surface charges of complexes due to the formation of micelles increasing the local charges. The presence of mPEG segment in gene vector decreased the surface charges of the complexes and increased the stability of the complexes in serum because of the steric hindrance effect. It was also found that the combination of PEG and PCL segments into one macromolecule might lead to synergistic effect for better transfection efficiency in serum.


Assuntos
Técnicas de Transferência de Genes , Vetores Genéticos , Polímeros/química , Polímeros/síntese química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Células COS , Chlorocebus aethiops , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/toxicidade , Etilaminas/química , Etilenoglicóis/química , Espectroscopia de Ressonância Magnética , Teste de Materiais , Metacrilatos/química , Micelas , Tamanho da Partícula , Poliésteres/química , Polietilenoglicóis/química , Polímeros/toxicidade , Transfecção
8.
Acta Biomater ; 6(7): 2658-65, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20097315

RESUMO

In this study poly(aminoethyl methacrylate) (PAEMA), poly(3-amino-2-hydroxypropyl methacrylate) (PAHPMA), poly(2-(2-aminoethylamino)ethyl methacrylate) (PAEAEMA) and poly(3-(2-aminoethylamino) 2-hydroxypropyl methacrylate) (PAEAHPMA) were synthesized using atom transfer radical polymerization to evaluate the effect of hydroxyl groups on the relative properties of cationic polymeric gene vectors. The results of heparin displacement assays showed that PAHPMA possessed a stronger binding capacity than PAEMA. PAHPMA/DNA complexes and PAEAHPMA/DNA complexes had lower zeta potentials than those of PAEMA and PAEAEMA. MTT assay results indicated that PAHPMA and PAEAHPMA exhibited obviously lower cytotoxicities than PAEMA and PAEAEMA. Subsequently, in vitro gene transfection studies in 293T cells without serum showed that PAHPMA exhibited a lower transfection efficiency than PAEMA and PAEAHPMA/DNA complexes possessed a similar transfection efficiency to PAEAEMA/DNA complexes. Moreover, PAHPMA and PAEAHPMA retained similar transfection efficiencies in DMEM with 10% serum, but PAEMA and PAEAEMA showed slightly lower transfection efficiencies than in the absence of serum. The reason for these phenomena might be attributed to the introduction of hydroxyl groups into PAHPMA and PAEAHPMA, i.e. the existence of hydroxyl groups might increase the binding capacity to DNA and at the same time decrease the surface charge of the polymer/DNA complexes due to the formation of hydrogen bonds between the polymers and DNA. Therefore, a lower zeta potential and stronger binding ability may result in a lower gene transfection efficiency. This effect of hydroxyl groups decreased with increasing amino group density on the polymer.


Assuntos
Vetores Genéticos , Radical Hidroxila/química , Ácidos Polimetacrílicos/administração & dosagem , Linhagem Celular , Cromatografia em Gel , Humanos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Ácidos Polimetacrílicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Transfecção
9.
Zhonghua Wai Ke Za Zhi ; 45(22): 1530-2, 2007 Nov 15.
Artigo em Chinês | MEDLINE | ID: mdl-18282386

RESUMO

OBJECTIVE: To evaluate the efficacy and practicability between bronchial sleeve resection or reconstruction of the pulmonary artery by video-assisted thoracic small incision and routine posterolateral incision for lung cancer. METHODS: The clinic data was analyzed retrospectively, including 139 cases in our hospital underwent sleeve lobectomy and bronchoplasty by video-assisted thoracic small incision surgery for lung cancer from January 1995 to July 2007 and 99 cases in the HUAXI Hospital of SICHUAN University underwent routine posterolateral incision from April 2000 to December 2005. All patients whose bronchus and/or pulmonary artery were involved underwent the operation and experienced the bronchial sleeve resection or reconstruction of the pulmonary artery. RESULTS: All patients were done operation successfully with no perioperative mortality and no occurrence of anastomosis stenosis as well as fistula. The median survival period of video-assisted thoracic small incision patients and the posterolateral incision patients were 63.17 months and 42.00 months, respectively (P > 0.05). There was no sign of reperfusion injury in the reconstruction of the pulmonary artery patients. The small incisions' length was from 8 to 13 cm and the mean length was 10 cm. The routine posterolateral incisions' mean length was 30 cm. Compared to the patients underwent the routine posterolateral incision, patients underwent the operation of video assisted thoracic small incision had less operation time, less chest tube time, less hospitalization time and less postoperative shoulder joint dysfunction. CONCLUSIONS: The bronchial sleeve resection and reconstruction of the pulmonary artery by video-assisted thoracic small incision surgery for lung cancer can finish the same work as the traditional thoracic lateral incision with less trauma and recovery time.


Assuntos
Brônquios/cirurgia , Neoplasias Pulmonares/cirurgia , Toracoscopia , Adulto , Idoso , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Pneumonectomia , Artéria Pulmonar/cirurgia , Veias Pulmonares/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
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