Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Environ Sci Technol ; 58(5): 2574-2583, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38266484

RESUMO

To recover multimedia mercury from coal-fired power plants, a novel N-containing conjugated polymer (polyaniline and polypyrrole) functionalized fly ash was prepared, which could continuously adsorb 99.2% of gaseous Hg0 at a high space velocity of 368,500 h-1 and nearly 100% of aqueous Hg2+ in the solution pH range of 2-12. The adsorption capacities of Hg0 and Hg2+ reach 1.62 and 101.36 mg/g, respectively. Such a kind of adsorbent has good environmental applicability, i.e. good resistance to coexisting O2/NO/SO2 and coexisting Na+/K+/Ca2+/Mg2+/SO42-. This adsorbent has very low specific resistances (6 × 106-5 × 109 Ω·cm) and thus can be easily collected by an electrostatic precipitator under low-voltage (0.1-0.8 kV). The Hg-saturated adsorbent can desorb almost 100% Hg under relatively low temperature (<250 °C). Characterization and theoretical calculations reveal that conjugated-N is the critical site for adsorbing both Hg0 and Hg2+ as well as activating chlorine. Gaseous Hg0 is oxidized and adsorbed in the form of HgXClX(ad), while aqueous Hg2+ is adsorbed to form a complex with conjugated-N, and parts of Hg2+ are reduced to Hg+ by conjugated-N. This adsorbent can be easily large-scale manufactured; thus, this novel solid waste functionalization method is promising to be applied in coal-fired power plants and other Hg-involving industrial scenes.


Assuntos
Poluentes Atmosféricos , Mercúrio , Cinza de Carvão/química , Poluentes Atmosféricos/análise , Mercúrio/análise , Multimídia , Polímeros , Carvão Mineral , Pirróis , Gases , Centrais Elétricas
2.
Mikrochim Acta ; 190(4): 151, 2023 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-36952093

RESUMO

The development of molecularly imprinted monolith (MIM) for pipette-tip solid-phase extraction (PT-SPE) for sample pretreatment is challenging . In this work, a wax-based molecularly imprinted monolith (WMIM) was successfully prepared with a hybrid method by integration of the traditional packing SPE column and MIM, including preparation of the salt column inside the pipette, polymerization of wax-based imprinted column (WIC) outside the pipette, and immobilization of WIC inside the pipette tip. To ensure the penetration of samples and solvents during the PT-SPE, micrometer-range interconnected macropores were tailor-made via the salt-template sacrifice method. For the production of high affinity imprinted sites within the WIC, octadecanoic acid was used as functional monomer in the paraffin matrix. In terms of the adsorption property, the synthesized WIC exhibited a specific affinity to cardiovascular drugs, with an imprinting factor (IF) of 4.8 for the target analyte. Moreover, the WMIM-based PT-SPE was coupled with fluorescence spectrophotometry for the target propranolol determination  (the excitation and emission wavelengths were 294 nm and 343 nm, respectively). This analytical method showed high recovery of target detection in different real samples (R > 90%), good sensitivity, and accuracy (R2 = 0.99, LOD = 0.03 ng mL-1). We believe this work could provide a significant contribution  for the fabrication of MIM and promote an emerging trend of developing elution-free materials for sample pretreatment.


Assuntos
Impressão Molecular , Impressão Molecular/métodos , Polímeros , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida/métodos , Solventes
3.
J Clin Lab Anal ; 36(5): e24371, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35334501

RESUMO

BACKGROUND: Vascular cell adhesion molecule (VCAM-1) mediates pulpitis via regulating interleukin (IL)-1ß. microRNA (miR)-126 was reported to regulate the VCAM-1 under many different pathophysiological circumstances. We investigated variations of miR-126 and VCAM-1 in inflamed patient pulp tissues and determined potential roles of miR-126 in pulpitis using human dental pulp cells (hDPCs) in vitro. METHODS: We quantitatively measured the transcripts of miR-126 and VCAM-1 in inflamed human pulp tissues using qRT-PCR and compared with those from healthy human pulp tissues. In addition, we transfected miR-126 in hDPCs using plasmid DNA (pDNA)-encoding miR-126 delivered by polyethylenimine (PEI) nanoparticles. RESULTS: The irreversible pulpitis significantly reduced miR-126 and increased the transcript of VCAM-1 in pulp tissues (p < 0.05). pDNA-encoding miR-126 delivered PEI nanoparticles and effectively upregulated the expression of miR-126 in hDPCs (p < 0.05). The overexpression of miR-126 could effectively suppress the transcripts and protein levels of VCAM-1 and IL-1ß induced by Pg-LPS at 100ng/mL in DPCs (p < 0.05). CONCLUSIONS: miR-126 is involved in pulpitis and downregulated the VCAM-1 and IL-1ß in DPCs. miR-126 may be a potential target to attenuate the inflammation of pulpitis.


Assuntos
MicroRNAs , Pulpite , Células Cultivadas , Polpa Dentária , Humanos , Interleucina-1beta/genética , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , Pulpite/induzido quimicamente , Pulpite/metabolismo , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo
4.
Mikrochim Acta ; 189(9): 324, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35939150

RESUMO

An electromembrane microextraction (EME)-assisted fluorescent molecularly imprinted polymer (MIP) sensing method is presented for detecting the total cathinone drugs in urine samples. In this detection system, the clean-up ability of EME eliminated the matrix effects on both target binding with MIPs and the luminescence of the fluorophore in the sensor. Moreover, by optimizing the extraction conditions of EME, different cathinone drugs with a same concentration show a same response on the single aggregation induced emission (AIE) based MIP (AIE-MIP) sensor (λex = 360 nm, λem = 467 nm). The recoveries were 57.9% for cathinone (CAT) and 78.2% for methcathinone (MCAT). The EME-assisted "light-up" AIE-MIP sensing method displayed excellent performance with a linear range of 2.0-12.0 µmol L-1 and a linear determination coefficient (R2) of 0.99. The limit of detection (LOD) value for EME-assisted "light-up" AIE-MIP sensing method was 0.3 µmol L-1. The relative standard deviation (RSD) values for the detection were found to be within the range 2.0-12.0%. To the best of our knowledge, this is the first time that determination of total illicit drugs with a single fluorescent MIP sensor was achieved and also the first utilization of sample preparation to tune the sensing signal of the sensor to be reported. We believe that this versatile combination of fluorescent MIP sensor and sample preparation can be used as a common protocol for sensing the total amount of a group of analytes in various fields.


Assuntos
Alcaloides , Impressão Molecular , Corantes , Limite de Detecção , Impressão Molecular/métodos , Polímeros
5.
Cell Physiol Biochem ; 43(6): 2535-2547, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29131087

RESUMO

BACKGROUND/AIMS: As a vital degradation and recycling system, autophagy plays an essential role in regulating the differentiation of stem cells. We previously showed that iron chelator deferoxamine (DFO) could promote the repair ability of dental pulp stem cells (DPSCs). Here, we investigated the effect of DFO in autophagy and the role of autophagy in regulating the migration and odontoblast differentiation of DPSCs. METHODS: Transmission electron microscopy, immunofluorescence staining and western blotting were performed to evaluate the autophagic activity of DPSCs. Transmigration assay, alkaline phosphatase staining/activity, alizarin red S staining and quantitative PCR were performed to examine the migration and odontoblast differentiation of DPSCs. Reactive oxygen species (ROS) levels and the effects of ROS scavenger in autophagy induction were also detected. Autophagy inhibitors (3-MA and bafilomycin A1) and lentiviral vectors carrying ATG5 shRNA sequences were used for autophagy inhibition. RESULTS: Early exposure to DFO promoted the mineralization of DPSCs and increased autophagic activity. Autophagy inhibition suppressed DFO-induced DPSC migration and odontoblast differentiation. Furthermore, DFO treatment could induce autophagy partly through hypoxia-inducible factor 1α/B cell lymphoma 2/adenovirus E1B 19K-interacting protein 3 (HIF-1α/BNIP3) pathway in a ROS-dependent manner. CONCLUSION: DFO increased DPSC migration and differentiation, which might be modulated through ROS-induced autophagy.


Assuntos
Autofagia/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Desferroxamina/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Adolescente , Proteína 5 Relacionada à Autofagia/antagonistas & inibidores , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Polpa Dentária/citologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Macrolídeos/farmacologia , Proteínas de Membrana/metabolismo , Microscopia Eletrônica de Transmissão , Proteínas Associadas aos Microtúbulos/metabolismo , Odontoblastos/citologia , Odontoblastos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Adulto Jovem
6.
Biomacromolecules ; 16(11): 3723-9, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26444105

RESUMO

In this work we report the in situ preparation of fully biobased stereocomplex poly(lactide) (SC-PLA) nanocomposites grafted onto nanocrystalline cellulose (NCC). The stereocomplexation rate by compounding high-molar-mass poly(D-lactide) (PDLA) with comb-like NCC grafted poly(L-lactide) is rather high in comparison with mixtures of PDLA and PLLA. The rapid stereocomplexation was evidenced by a high stereocomplexation temperature (Tc-sc = 145 °C) and a high SC crystallinity (Xc-sc = 38%) upon fast cooling (50 °C/min) from the melt (250 °C for 2 min), which are higher than currently reported values. Moreover, the half-life crystallization time (175-190 °C) of the SC-PLA was shortened by 84-92% in comparison with the PDLA/PLLA blends. The high(er) stereocomplexation rate and the melt stability of the SC in the nanocomposites were ascribed to the nucleation effect of the chemically bonded NCC and the "memory effect" of molecular pairs in the stereocomplex melt because of the confined freedom of the grafted PLLA chains.


Assuntos
Celulose/química , Poliésteres/química , Materiais Biocompatíveis/química , Varredura Diferencial de Calorimetria , Cristalização , Meia-Vida , Microscopia de Força Atômica , Peso Molecular , Nanoestruturas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Difração de Raios X
7.
Analyst ; 139(13): 3365-8, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24828541

RESUMO

We report a sensitive, selective and low-cost method for the naked-eye detection of Hg(2+). The principle is based on rapid interaction between functionalized PDA vesicles and Hg(2+), which leads to obvious aggregation of vesicles. Furthermore, using only a simple filtration process, without using any other color indicator or specialized equipment, a higher detection sensitivity for Hg(2+) (0.1 µM) than chromophoric colorimetric sensors (approximately 1-100 µM) was obtained.


Assuntos
Colorimetria , Mercúrio/análise , Polímeros/química , Poli-Inos/química , Timina/química , Cátions Bivalentes/análise , Colorimetria/economia , Colorimetria/métodos , Filtração , Limite de Detecção , Polímero Poliacetilênico , Polímeros/isolamento & purificação , Poli-Inos/isolamento & purificação , Timina/isolamento & purificação
8.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(6): 898-902, 2014 Nov.
Artigo em Zh | MEDLINE | ID: mdl-25571711

RESUMO

OBJECTIVE: To investigate the feasibility of tracking bone mesenchymal stem cell (BMSCs) dual- labeled with polyethylenimine 2k-superparamagnetic iron oxide (PEI2k-SPIO) and Luciferase transplantation for acute myocardial infarction in vivo by using magnetic resonance imaging (MRI) and fluorescence imaging. METHODS: BMSCs/Luciferase was incubated with culture medium containing PEI2k-SPIO for 24 h. Prussian-blue staining and MTT were used to assess the efficacy and safety of labeling with PEI2k-SPIO. Guided with echocardiography, the dual-labeled BMSCs were injected into the margin of infarction myocardium. MRI and fluorescence imaging were performed to monitor the cells in vivo at different times (1,2,3,7 d). RESULTS: As demonstrated by MTT, there was no significant difference in survival rate between the labeled and unlabeled cells (P>0. 05). Within a week after transplantation, all PEI2k-SPIO-labeled BMSCs showed a significant decreased signal on MRI. Dual-labeled BMSCs were detected bioluminescence with fluorescence imaging, but disappeared after one week. CONCLUSION: Multi- modality imaging can not only trace the location of labeled BMSCs but also demonstrate the survival of labeled BMSCs in vivo.


Assuntos
Transplante de Células-Tronco Mesenquimais , Imagem Molecular , Infarto do Miocárdio/terapia , Animais , Dextranos , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Células-Tronco Mesenquimais , Polietilenoimina
9.
Int J Biol Macromol ; 265(Pt 1): 130911, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38492693

RESUMO

In this study, the solubilization and structural changes of lignin in naked oat stems were investigated under subcritical water autohydrolysis systems (170-210 °C, 0.68-1.85 MPa). In this system, Hemicellulose was preferentially hydrolyzed in the liquid water at elevated temperatures, leading to the production of acetic acid and glucuronic acid, which acidified the reaction system. Under acidic and high-temperature conditions, lignin primarily underwent degradation and condensation reactions. At autohydrolysis temperatures below 190 °C and autohydrolysis pressures below 1.22 MPa, lignin degradation was predominant, realizing a maximum lignin removal of 47.8 % and breakage of numerous ß-O-4 bonds from lignin. At autohydrolysis temperatures above 190 °C and autohydrolysis pressures above 1.22 MPa, lignin condensation dominated, with an increase in the amount of organic acids generated upon hemicellulose degradation, leading to condensation reactions with the degraded low-molecular-weight lignin. The degree of lignin condensation was positively correlated with the temperature of the reaction system. This study provides essential insights into the dynamic changes in the structure of lignin in both the hydrolysis residue and hydrolysis solution during subcritical water autohydrolysis.


Assuntos
Lignina , Água , Lignina/química , Avena , Compostos Orgânicos , Temperatura , Hidrólise
10.
Int J Biol Macromol ; 261(Pt 2): 129834, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38302029

RESUMO

The unique stere-complex crystal formed by poly(ʟ-lactide)/poly(ᴅ-lactide) (PLLA/PDLA) has a significant impact on properties of poly-lactide materials and is considered an effective means to improve the barrier properties of poly-lactide (PLA). In this work, poly-lactide films with different aggregate structures were prepared and the relationship of aggregate structure and barrier properties were explored. The results show that the crystal structure including crystallinity and crystal forms can be controlled by adjusting the isothermal crystallization time and crystallization temperature during the molding process. PLLA/PDLA composite films contain both homochiral crystallites and stereo-complex crystallites, and there is a synergistic crystallization effect between the two of them, which provides the composite films with high crystallinity and excellent barrier properties. Compared to the PLLA with homochiral crystallites, the PLLA/PDLA composite film with only stereo-complex crystallites exhibits higher barrier properties. The linear correlation between the crystallinity and the barrier properties is weak due to the changes in crystallization behavior and then the structure of poly-lactide caused by stereo-complexation. The linear correlation between the crystallinity and the barrier properties of the blend film is strong in the low crystallinity but weak at high crystallinity. Compared to homochiral crystallites, stereo-complex crystallites exhibits lower crystallinity dependence. It has been proven that different crystal forms have different design ideas for preparing high-barrier films, but the stereo-complexation resulting from the intermolecular forces between PLLA and PDLA having complementary chemical structure, is an effective method for enhancing the barrier performances of poly-lactide sustainably.


Assuntos
Dioxanos , Poliésteres , Cristalização , Poliésteres/química
11.
BMC Cancer ; 13: 129, 2013 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-23510112

RESUMO

BACKGROUND: Oral cancer develops through multi-stages: from normal to mild (low grade) dysplasia (LGD), moderate dysplasia, and severe (high grade) dysplasia (HGD), to carcinoma in situ (CIS) and finally invasive oral squamous cell carcinomas (OSCC). Clinical and histological assessments are not reliable in predicting which precursor lesions will progress. The aim of this study was to assess the potential of a noninvasive approach to assess progress risk of oral precancerous lesions. METHODS: We first used microRNA microarray to profile progressing LGD oral premaligant lesions (OPLs) from non-progressing LGD OPLs in order to explore the possible microRNAs deregulated in low grade OPLs which later progressed to HGD or OSCC. We then used RT-qPCR to detect miRNA targets from the microarray results in saliva samples of these patients. RESULTS: We identified a specific miRNA signature that is aberrantly expressed in progressing oral LGD leukoplakias. Similar expression patterns were detected in saliva samples from these patients. CONCLUSIONS: These results show promise for using saliva miRNA signature for monitoring of cancer precursor lesions and early detection of disease progression.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma in Situ/genética , Carcinoma de Células Escamosas/genética , Leucoplasia Oral/genética , MicroRNAs/genética , Neoplasias Bucais/genética , Lesões Pré-Cancerosas/genética , Saliva , Idoso , Carcinoma in Situ/patologia , Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/genética , Progressão da Doença , Feminino , Humanos , Leucoplasia Oral/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Lesões Pré-Cancerosas/patologia , Medição de Risco
12.
Clin Case Rep ; 11(9): e7831, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37636887

RESUMO

Key Clinical Message: A 31-year-old female with a diagnosis of bipolar disorder developed black hairy tongue after alprazolam therapy. Her symptom resolved 10 days after the cessation of alprazolam. Abstract: Alprazolam is a widely used antidepressant and antianxiety drug. Mild to moderate side effect of alprazolam was commonly seen, including lethargy, dizziness, headache, dry mouth, nausea, fatigue, constipation, and blurred vision. In this case, we reported a patient developed black hairy tongue after alprazolam intake, and her symptom resolved after 10-day discontinuation of alprazolam. This rare adverse event should be of concern to clinicians. This is the first paper to report an alprazolam-induced BHT. This rare side effect of alprazolam should be concern of clinicians; we hope our report will promote the understand of BHT and acknowledge clinicians of this rare side effect of alprazolam.

13.
Int J Biol Macromol ; 247: 125744, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37423438

RESUMO

Polylactide, a biodegradable polymer, can alleviate white pollution, but the use of polylactide in food packaging is limited by high transmittance to light with a specific wavelength, UV (185-400 nm) and short-wavelength visible (400-500 nm) light. Herein, the polylactide end-capped with renewable light absorber aloe-emodin (PLA-En), is blended with commercial polylactide (PLA) to fabricate the polylactide film with the function of blocking light with a specific wavelength, PLA/PLA-En film. Only 40 % of light around 287 and 430 nm transmits through PLA/PLA-En film incorporating 3 mass% of PLA-En, while the film still maintains good mechanical properties and high transparency more than 90 % at 660 nm because of the good compatibility with PLA. The PLA/PLA-En film exhibits stable light-blocking properties under light irradiation and anti-solvent migration under the immersion of fat simulant. Almost no PLA-En migrated out of the film with the molecular weight of PLA-En only 2.89 × 104 g/mol. Compared with PLA film and commercial PE plastic wrap, the designed PLA/PLA-En film exhibits a better preservative effect on riboflavin and milk for inhibiting the production of 1O2. This study offers a green strategy for developing UV and short-wavelength light protective food package film based on renewable resource.


Assuntos
Aloe , Emodina , Poliésteres , Polímeros
14.
Waste Manag ; 169: 374-381, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37527617

RESUMO

Waste nylon-tire (WNT) is a typical solid municipal waste, pyrolysis efficiently disposes WNT to produce oil containing high-value chemicals. Upgrading the quality of oil is the key to improve WNT pyrolysis economy. Herein, swelling was applied to pretreat WNT, and swelled waste nylon-tire (SWNT) was pyrolyzed at different temperatures (400 °C-600 °C). Lower than 500 °C, swelling pretreatment realized the number of compounds in oil by GC-MS decreased 59.57% at 400 °C (60.78% at 450 °C, 67.97% at 500 °C) compared to Waste nylon-tire pyrolytic oil (TPO). Over 500 °C, this phenomenon weakened, decreased 47.67% at 550 °C (11.48% at 600 °C). At 400 °C and 450 °C, long chain methyl esters yield was over 30 A.% instead of short chain alkanes in TPO. D-limonene yield was over 20 A.% in oil of swelled waste nylon-tire (STPO). From 500 °C to 600 °C, swelling pretreatment affected the relative content of BTX and PAHs. At 500 °C and 550 °C, the relative content of BTX in STPO was more than twice of TPO, and BTX reached 28.75 A.% at 600 °C. PAHs in STPO appeared at 500 °C higher than TPO (450 °C), and PAHs was 0.73 A.% at 500 °C. Swelling pretreatment could produce more larger pores in particle during pyrolysis, which sharply inhibited the interaction of volatiles inside tire, so the number of compounds in oil sharply decreased at lower temperatures. Over 550 °C, temperature became the dominant role for generating oil, and components tended to be similar for STPO and TPO. CS2 with high-volatility released quickly from WNT during pyrolysis, it could be recycled to reduce final cost and environment impacts.


Assuntos
Nylons , Hidrocarbonetos Policíclicos Aromáticos , Pirólise , Temperatura , Alcanos , Resíduos Sólidos , Temperatura Alta
15.
Zhongguo Gu Shang ; 36(5): 445-9, 2023 May 25.
Artigo em Zh | MEDLINE | ID: mdl-37211937

RESUMO

OBJECTIVE: To verify the safety of three dimensional printing percutaneous guide plate assisted percutaneous kyphoplasty(PKP) in the treatment of osteoporotic vertebral compression fractures(OVCFs). METHODS: The clinical data of 60 patients with OVCFs treated by PKP from November 2020 to August 2021 were retrospectively analyzed. There were 24 males and 36 females, aged from 72 to 86 years old with an average of (76.5±7.9) years. Routine percutaneous kyphoplasty was performed in 30 cases (conventional group) and three dimensional printing percutaneous guide plate assisted PKP was performed in 30 cases (guide plate group). Intraoperative pedicle puncture time (puncture needle to posterior vertebral body edge) and number of fluoroscopy, total operation time, total number of fluoroscopy, amount of bone cement injection, and complication (spinal canal leakage of bone cement) were observed. The visual analogue scale (VAS) and the anterior edge compression rate of the injured vertebra were compared before operation and 3 days after operation between two groups. RESULTS: All 60 patients were successfully operated without complication of spinal canal leakage of bone cement. In the guide plate group, the pedicle puncture time was(10.23±3.15) min and the number of fluoroscopy was(4.77±1.07) times, the total operation time was (33.83±4.21) min, the total number of fluoroscopy was(12.27±2.61) times;and in the conventional group, the pedicle puncture time was (22.83±3.09) min and the number of fluoroscopy was (10.93±1.62) times, the total operation time was(44.33±3.57) min, the total number of fluoroscopy was(19.20±2.67) times. There were statistically significant differences in the pedicle puncture time, intraoperative number of fluoroscopy, the total operation time, and the total number of fluoroscopy between the two groups(P<0.05). There was no significant difference in amount of bone cement injection between the two groups(P>0.05). There were no significant differences in VAS and the anterior edge compression rate of the injured vertebra at 3 days after operation between two groups(P>0.05). CONCLUSION: Three dimensional printing percutaneous guide plate assisted percutaneous kyphoplasty is safe and reliable, which can reduce the number of fluoroscopy, shorten the operation time, and decrease the radiation exposure of patients and medical staff, and conforms to the concept of precise orthopaedic management.


Assuntos
Fraturas por Compressão , Cifoplastia , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Masculino , Feminino , Humanos , Idoso , Idoso de 80 Anos ou mais , Cifoplastia/métodos , Fraturas por Compressão/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Cimentos Ósseos , Estudos Retrospectivos , Resultado do Tratamento , Fraturas por Osteoporose/cirurgia
16.
Nanomedicine ; 8(1): 46-53, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21658475

RESUMO

The effect of gold nanoparticles (Au NPs) on cells remains open for investigation. Here we show that small Au NPs can be endocytosed by cells and form aggregates inside the cell, resulting in cytotoxicity. When the aggregates become too large to enter the cell and instead adhere onto the cell surface, however, the growth rate of HeLa cells increases. Printed patterns of Au NPs fabricated through inkjet printing technology were used to study the effects of Au NP aggregation on human cervical carcinoma (HeLa) cell activity. The growth of the HeLa cells was inhibited on the polymer-coated Au NPs but increased on the silicon substrate. On the uncoated Au NP surface, however, the HeLa cell growth rate was higher than that on the silicon substrate. Experiments with Escherichia coli cells showed a similar effect of the Au NPs. This phenomenon provides a new perspective for research on toxicity in nanoparticle biology. FROM THE CLINICAL EDITOR: Printed patterns of Au NPs fabricated through inkjet printing technology were used to study the effects of Au NP aggregation on human cervical carcinoma (HeLa) cell activity. Small Au NPs can be endocytosed by cells resulting in cytotoxicity; in contrast, large aggregates adhere onto the cell surface and increase the growth rate of HeLa cells.


Assuntos
Escherichia coli/efeitos dos fármacos , Ouro/toxicidade , Nanopartículas/toxicidade , Proliferação de Células/efeitos dos fármacos , Endocitose/fisiologia , Escherichia coli/citologia , Células HeLa/efeitos dos fármacos , Humanos , Polímeros/química , Povidona/química , Propriedades de Superfície , Análise Serial de Tecidos
17.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 43(4): 578-83, 2012 Jul.
Artigo em Zh | MEDLINE | ID: mdl-22997900

RESUMO

OBJECTIVE: To explore the optimal concentration of polyethylenimine-superparamagnetic iron oxide (PEI2k-SPIO) particles for labeling bone marrow mesenchymal stem cells (BMSCs) in vitro, then to demonstrate the imaging characteristics of the cells by 7.0-T MR scanner. The lowest cell quantity and the optimal cell quantity detected on MR was observed. METHODS: Cells at 2nd passage were inoculated into the 6-hole plate with cover glass. The different concentrations of PEI2k-SPIO (5 microg/mL, 7 microg/mL, 10 microg/mL, 15 microg/mL, 20 microg/mL) were added into different holes, respectively. After labeled with different concentrations of PEI2k-SPIO, the Prussian blue stain was used for determining the labeling efficiency. MTT growth curves were used to identify the activity of BMSCs and to determine the optimal threshold of SPIO nanocomposite particles labeled the stem cells at different PEI2k-SPIO concentrations (7, 10, 15, 20 microg Fe/mL medium). To definite the lowest cells quantity and the optimal observable cells quantity on MR imaging, 1 x 10(6), 1 x 10(5), 1 x 10(4) and 1 x 10(3) cells labeled with optimal threshold of PEI2k-SPIO and 1 x 10(6) cells unlabeled suspended in 0.2 mL agarose (10 g/L), respectively undergone MR scan. RESULTS: MTT growth curves showed the optimal threshold of PEI2k-SPIO labeled BMSCs was 7 microg/mL, which indicates has no adverse effects on the growth of stem cells. At the opimal concentration (7 microg Fe/mL), the lowest observable cell quantity of PEI2k-SPIO-labeled cells for MRI was 1 x 10(4), and the optimal observable cell quantity was 1 x 10(6). CONCLUSION: At the opimal concentration, adverse effect to stem cell activities had not be detected when were labeled with PEI2k-SPIO and the clearly image of MRI of labeled BMSCs could be obtained.


Assuntos
Rastreamento de Células , Dextranos/química , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita/química , Células-Tronco Mesenquimais/citologia , Polietilenoimina/química , Animais , Animais Recém-Nascidos , Células Cultivadas , Feminino , Compostos Férricos , Masculino , Ratos , Ratos Sprague-Dawley
18.
Arch Oral Biol ; 133: 105312, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34808514

RESUMO

OBJECTIVE: RNA-activated protein kinase-like ER-resident kinase (PERK) was a major transducer of Endoplasmic reticulum (ER) stress response and it directly phosphorylated α-subunit of eukaryotic initiation factor 2 (eIF2α), which specifically promoted the translation of activating transcription factor 4 (ATF4), an important transcription factor in cells' differentiation. The purpose of this study was to establish whether ER stress mediated by PERK-eIF2α-ATF4 pathway was involved in odontoblastic differentiation of human dental pulp cells (DPCs). METHODS: DPCs were isolated from extracted teeth and cultured in odontogenic medium. A recombinant lentiviral vector was constructed to transfect DPCs for PERK knockdown. Alkaline phosphatase (ALP) and Alizarin red S staining were used to characterize the odontoblastic differentiation. Real-time polymerase chain reactions (RT-PCR) were performed to analyze the genes' expressions in DPCs' odontoblastic differentiation. The mRNA and protein levels of ER stress markers were examined by RT-PCR and western blot. RESULTS: DPCs cultured in odontogenic media showed increased ALP activity and mineralized nodule formation. Notably, treatment with differentiation medium resulted in the up-regulation of genes, such as osteocalcin (OCN), bone sialoprotein (BSP), dentin sialophosphoprotein (DSPP), splicing x-box binding protein-1 (sXBP1), ATF4 and glucose-regulated protein 78 (GRP78). Meanwhile, the expressions of PERK-eIF2α-ATF4 pathway proteins, phosphorylated PERK, phosphorylated eIF2α and ATF4, increased in odontoblastic induction cells compared with controls. Furthermore, inhibition of PERK (PERK knockdown) decreased ALP activity and matrix mineralization in DPCs accompanied by the decrease expression of phosphorylated eIF2α and ATF4. CONCLUSION: These results suggested that PERK-eIF2α-ATF4 pathway was involved in the odontoblastic differentiation of DPCs.


Assuntos
Fator 4 Ativador da Transcrição , Fator de Iniciação 2 em Eucariotos , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Diferenciação Celular , Polpa Dentária/metabolismo , Estresse do Retículo Endoplasmático , Fator de Iniciação 2 em Eucariotos/metabolismo , Humanos , Odontoblastos/metabolismo , Transdução de Sinais
19.
Biosens Bioelectron ; 205: 114113, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35219945

RESUMO

Development of a specific "light-up" sensor for detection of psychoactive drug has been a great challenge in forensic analysis. To achieve this goal, an aggregation induced emission (AIE) functional monomer containing both phenylboronic group and double bond was synthesized for construction of molecularly imprinted polymers (MIPs) based fluorescent sensor. In this AIE-MIP sensor, the AIE fluorophore could vibrate freely in the absence of the target analyte (cathinone, CAT), while this vibration was restricted after the specific molecular recognition, leading to "light-up" character of the corresponding sensor. FT-IR and LC-MS characterizations proved the AIE monomer was successfully introduced onto AIE-MIPs. SEM analysis indicated the AIE-MIPs was ∼140 nm in diameter. Binding experiments indicated the AIE-MIPs owned high specificity towards CAT. Fluorescent studies confirmed that the "light-up" capability of the AIE-MIPs was highly selective. On this basis, the AIE-MIP sensor was applied in detecting CAT in forensic samples. The sensor reached a detection limit of 0.32 µmol L-1 and exhibited a linear range of 2-12 µmol L-1. Compared to previously reported MIPs based electrochemical sensors and fluorescent sensors for measurement of CAT drug and its analogue, the present AIE-MIP sensor showed much higher sensitivity. To the best of our knowledge, this is the first time that an AIE functional monomer was synthesized for molecular imprinting, and also the first "light-up" AIE-MIP sensor to be reported. We believe that this versatile design of the specific "light-up" sensor can be used as a general protocol for construction of advanced sensor in various fields.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Impressão Molecular/métodos , Polímeros Molecularmente Impressos , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Int J Biol Macromol ; 207: 927-940, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35364194

RESUMO

Up to now, unbalanced mechanical properties and poor heat resistance have become two major problems of polylactic acid (PLA). In this study, the coupling between Cellulose nanocrystal (CNC) and strong shearing field formed a unique hierarchical structure. Compared with pure PLA, the tensile strength of DPIM PLA/CNC increased from 57.9 MPa to 79.6 MPa without sacrificing the toughness of PLA, and the vicat softening temperature of DPIM PLA/CNC increased from 60 °C to 155 °C. The microstructure of PLA/CNC composites was analyzed by SEM, SAXS and WAXD, and it was found that the coupling effect of CNC and strong shear flow field could significantly change the crystallization behavior of PLA. CNC could increase PLA shish length from 251 nm to 889 nm under the action of shear field. At the same time, due to this coupling effect, more PLA shish-kebab structures were induced at the interface. This special hierarchical structure composed of CNC and PLA Shish-Kebab is of great significance and can provide important guidance for achieving the balance of strength and toughness of polymer materials.


Assuntos
Celulose , Nanopartículas , Celulose/química , Nanopartículas/química , Poliésteres/química , Espalhamento a Baixo Ângulo , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA