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1.
Cancer Manag Res ; 11: 9439-9448, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31807073

RESUMO

Purpose: This study aimed to develop and validate a nomogram for predicting the malignancy of small (8-20 mm) solid indeterminate solitary pulmonary nodules (SPNs) in a Chinese population by using routine clinical and computed tomography data. Methods: The prediction model was developed using a retrospective cohort that comprised 493 consecutive patients with small indeterminate SPNs who were treated between December 2012 and December 2016. The model was independently validated using a second retrospective cohort comprising 216 consecutive patients treated between January 2017 and May 2018. The investigated variables included patient characteristics (e.g., age and smoking history), nodule parameters (e.g., marginal spiculation and significant enhancement), and tumor biomarker levels (e.g., carcinoembryonic antigen). A prediction model was developed by using multivariable logistic regression analysis, and the model's performance was presented as a nomogram. The model was evaluated based on its discriminative ability, calibration, and clinical usefulness. Results: The developed nomogram was ultimately based on age, marginal spiculation, significant enhancement, and pleural indentation. The Harrell concordance index values were 0.869 in the training cohort (95% confidence interval: 0.837-0.901) and 0.847 in the validation cohort (95% confidence interval: 0.792-0.902). The Hosmer-Lemeshow test revealed good calibration in each of the training and validation cohorts. Decision curve analysis confirmed that the nomogram was clinically useful (risk threshold from 0.10 to 0.85). Conclusion: Patient age, marginal spiculation, significant enhancement, and pleural indentation are independent predictors of malignancy in small indeterminate solid SPNs. The developed nomogram is easy-to-use and may allow the accurate prediction of malignancy in small indeterminate solid SPNs among Chinese patients.

2.
Clin Ther ; 41(11): 2263-2272, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561881

RESUMO

PURPOSE: The aim of the study is to compare the free hexafluoro-isopropanol (HFIP) concentration in adults' blood and the incidence of emergence agitation (EA) after inhaled different concentrations of sevoflurane. METHODS: Sixty adult patients planning to undergo laparoscopic gastrointestinal surgery were randomly assigned to 3 groups. Each group received sevoflurane as the volatile anesthetic at different concentrations: 0.5 minimum alveolar concentration (MAC), 1.0 MAC, and 1.5 MAC. The use of sevoflurane was continued until the end of surgery. Venous blood samples were obtained at 30, 60, 120, and 180 minutes after starting the use of sevoflurane and subsequently at 60, 180, and 300 minutes after discontinuation of volatile anesthetic administration. Blood concentrations of sevoflurane and free HFIP were determined using gas chromatography. The recovery time and the incidence of EA at different time points were evaluated among the 3 groups. FINDINGS: Changes in the blood concentrations of sevoflurane and free HFIP during and after the use of sevoflurane were similar in all 3 groups. The peak blood concentration of free HFIP occurred 60 minutes after onset of sevoflurane anesthesia in all 3 groups (P < 0.05). The lowest level of free HFIP and the longest recovery time were found in the 1.5-MAC group (P < 0.05). No significant difference was found in the incidence of EA or moderate pain among the 3 groups during recovery. IMPLICATIONS: The generation of HFIP would be inhibited when the inhaled sevoflurane concentration increased to 1.5 MAC. However, the incidence of EA during recovery had nothing to do with the inhaled different sevoflurane concentrations (within 1.5 MAC) in adults. ChicCTR.org identifier: ChiCTR-IPD-17011558.

3.
Mater Sci Eng C Mater Biol Appl ; 105: 110042, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546440

RESUMO

Influences of proteins on degradation of magnesium alloys are of great significance but not well understood. In particular the roles of amino acids, the basic unit of proteins in regulating the progress of biodegradation of magnesium based materials remain unclear. This study aims to investigate the impacts of alanine, glutamic acid and lysine on degradation of pure magnesium in phosphate buffer solution through SEM, XPS, FTIR, potentiodynamic polarisation curves, electrochemical impedance spectroscopy and immersion tests. The changed contents of amino acids in solutions were detected by UV-vis spectrophotometer. Results demonstrate that the charges of the selected amino acids imposed significant contribution to suppressing the degradation of pure magnesium in phosphate buffer solution. The presence of amino acids led to the formation of phosphate-based corrosion products, increasing free corrosion potential, and reduction in corrosion current density and solution pH depending on their isoelectric points and molecular structures. A plausible corrosion mechanism organised by amino acids on pure magnesium was proposed.


Assuntos
Aminoácidos/química , Magnésio/química , Fosfatos/química , Tampões (Química) , Corrosão , Espectroscopia Dielétrica , Eletroquímica , Humanos , Hidrogênio/análise , Ponto Isoelétrico , Conformação Molecular , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
4.
Mater Sci Eng C Mater Biol Appl ; 104: 109926, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499938

RESUMO

Despite of technical advancements in design and development of new biomaterials, device-related infections continue to occur and can be life-threatening. Differing from existing research work pertaining to introducing antibacterial function upon device surface, this study attempts to address such germ-infection issues through controlled release of antibacterial species from bulk gallium (Ga) and strontium (Sr) containing magnesium (Mg) alloys. To validate such a conceptual framework, Mg alloys containing micro-level concentrations of Ga and/or Sr (0.1 wt%) are employed as model materials, along with commercially pure Mg and titanium (Ti) as control groups. Biodegradation progress of such metal specimens is examined through pH and mass loss measurements, and inductively coupled plasma - atomic emission spectrometry (ICP-AES) as a function of immersion time in Trypticase Soy Broth (TSB) solution under physiological conditions. In vitro biocompatibility and antibacterial performance are characterised through MTT proliferation assay with human mesenchymal stem cells (hMSCs) and the spread plate method with three representative bacterial strains, i.e. S. aureus (ATCC 43300), E. coli (ATCC 25922), and S. epidermidis (ATCC 35984). Animal tests are performed through implanting target metal rods into femurs of Sprague Dawley rats, accompanied with injection of S. aureus to build a model of osteomyelitis. Results demonstrate that such lean additions of Ga and/or Sr reduce the degradation kinetics of Mg matrix, and the release of Ga3+ ions plays a crucial role in disabling the viability of all selected bacterial strains. The histological tests confirm that the growth of fibrous tissue has been accelerated in the vicinity of Mg-based implants, in comparison to that of blank and c.p. Ti controls. It is also striking that the smallest number density of S. aureus bacteria on the surface of the retrieved Ga-containing Mg rod implants. Such a proof-of-concept study provides a new and feasible strategy to address the notorious device-infection issues associated with biomedical implants for bone fracture management.


Assuntos
Ligas/farmacologia , Antibacterianos/farmacologia , Gálio/farmacologia , Magnésio/farmacologia , Estrôncio/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Fêmur/efeitos dos fármacos , Fêmur/patologia , Humanos , Implantes Experimentais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Ratos Sprague-Dawley
5.
Materials (Basel) ; 12(15)2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31382506

RESUMO

Additive manufacturing (AM) is a rapidly growing field of technology. In order to increase the variety of metal alloys applicable for AM, selective laser melting (SLM) of duplex stainless steel 2205 powder and the resulting microstructure, density, mechanical properties, and corrosion resistance were investigated. An optimal set of processing parameters for producing high density (>99.9%) material was established. Various post-processing heat treatments were applied on the as-built predominantly ferritic material to achieve the desired dual-phase microstructure. Effects of annealing at temperatures of 950 °C, 1000 °C, 1050 °C, and 1100 °C on microstructure, crystallographic texture, and phase balance were examined. As a result of annealing, 40-46 vol.% of austenite phase was formed. Annealing decreased the high yield and tensile strength values of the as-built material, but significantly increased the ductility. Annealing also decreased the residual stresses in the material. Mechanical properties of the SLM-processed and heat-treated materials outperformed those of conventionally produced alloy counterparts. Using a scanning strategy with 66° rotation between layers decreased the strength of the crystallographic texture. Electrochemical cyclic potentiodynamic polarization testing in 0.6 M NaCl solution at room temperature showed that the heat treatment improved the pitting corrosion resistance of the as-built SLM-processed material.

6.
Acta Biomater ; 98: 196-214, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31154057

RESUMO

A Zinc-loaded montmorillonite (Zn-MMT) coating was hydrothermally prepared using Zn2+ ion intercalated sodium montmorillonite (Na-MMT) upon magnesium (Mg) alloy AZ31 as bone repairing materials. Biodegradation rate of the Mg-based materials was studied via potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests. Results revealed that both Na-MMT and Zn-MMT coatings exhibited better corrosion resistance in Dulbecco's modified eagle medium (DMEM) + 10% calf serum (CS) than bare Mg alloy AZ31 counterparts. Hemolysis results demonstrated that hemocompatibility of the Na-MMT and Zn-MMT coatings were 5%, and lower than that of uncoated Mg alloy AZ31 pieces. In vitro MTT tests and live-dead stain of osteoblast cells (MC3T3-E1) indicated a significant improvement in cytocompatibility of both Na-MMT and Zn-MMT coatings. Antibacterial properties of two representative bacterial strains associated with device-related infection, i.e. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), were employed to explore the antibacterial behavior of the coatings. The measured inhibitory zone and bacterial growth rate confirmed that Zn-MMT coatings exhibited higher suppression toward both E. coli and S. aureus than that of Na-MMT coatings. The investigation on antibacterial mechanism through scanning electron microscopy (SEM) and lactate dehydrogenase (LDH) release assay manifested that Zn-MMT coating led to severe breakage of bacterial membrane of E. coli and S. aureus, which resulted in a release of cytoplasmic materials from the bacterial cells. In addition, the good inhibition of Zn-MMT coatings against E. coli and S. aureus might be attributed to the slow but sustainable release of Zn2+ ions (up to 144 h) from the coatings into the culture media. This study provides a novel coating strategy for manufacturing biodegradable Mg alloys with good corrosion resistance, biocompatibility and antibacterial activity for future orthopedic applications. STATEMENT OF SIGNIFICANCE: The significance of the current work is to develop a corrosion-resistant and antibacterial Zn-MMT coating on magnesium alloy AZ31 through a hydrothermal method. The Zn-MMT coating on magnesium alloy AZ31 shows better corrosion resistance, biocompatibility and excellent antibacterial ability than magnesium alloy AZ31. This study provides a novel coating on Mg alloys for future orthopedic applications.

7.
ACS Appl Mater Interfaces ; 11(15): 14085-14094, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30942998

RESUMO

Non-noble metal-based bifunctional electrocatalysts for both oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) are an essential component of high-performance rechargeable Zn-air batteries (ZABs). Herein, we report a novel and simple method for preparing Co9S8 nanoparticles embedded in N and S codoped carbon materials with aid of carbon dots (CDs). CDs play a key role in distributing Co9S8 nanoparticles in the matrix uniformly and enhancing the specific surface area and the electric conductivity simultaneously. The obtained Co9S8/CD@NSC exhibits an excellent ORR and OER bifunctional catalytic activity and a great long-term durability, with a half-wave potential of 0.84 V versus reversible hydrogen electrode (RHE) for the ORR and a low potential of 1.62 V versus RHE at 10 mA cm-2, which outperform the popular Pt/C and RuO2 commercial catalysts. Moreover, the Co9S8/CD@NSC catalyst also displays a superior activity and cycling stability as a cathode material in ZABs, which is far better than Pt/C + RuO2 mixture catalysts. Such a ZAB shows a low charge/discharge voltage gap of 0.62 V and great cycling stability over 125 h at 10 mA cm-2.

8.
Talanta ; 195: 117-126, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625521

RESUMO

Photoluminescence(PL) nano-biosensors that can be used for accurately and reliably monitoring pH and vitamin hold a great promise in biology and medicine. Herein, a high quantum yield of 16% saccharomyces-derived N-doped carbon dots (s-N-CDs) was synthesized through a simple and one-pot microwave-assisted hydrothermal approach. The produced s-N-CDs are an excellent multi-functional biosensor for the applications of pH sensing and vitamin probing. Fluorescence intensity and fluorescence lifetime dramatically increases with pH decreasing from 14 to 2. Moreover, the fluorescence intensity presents highly reversible abilty from 13 to 2 without any profound attenuation after ten consecutive circles. More importantly, the CDs prepared herein are sound option for assaying cobalamin (VB 12) based fluorescence resonance energy transfer (FRET) with a superior low detection limit of 2.19 µM.


Assuntos
Técnicas Biossensoriais , Concentração de Íons de Hidrogênio , Vitamina B 12/análise , Carbono/química , Etilenodiaminas , Transferência Ressonante de Energia de Fluorescência , Limite de Detecção , Nanopartículas/química , Nitrogênio/química , Saccharomyces , Vitamina B 12/química , Vitaminas
9.
Respiration ; 97(1): 42-51, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30227423

RESUMO

BACKGROUND: Hydrogen-oxygen mixture (H2-O2) may reduce airway resistance in patients with acute severe tracheal stenosis, yet data supporting the clinical use of H2-O2 are insufficient. OBJECTIVES: To evaluate the efficacy and safety of breathing H2-O2 in acute severe tracheal stenosis. METHODS: Thirty-five consecutive patients with severe acute tracheal stenosis were recruited in this prospective self-control study. Air, H2-O2 and O2 inhalation was given in 4 consecutive breathing steps: air for 15 min, H2-O2 (6 L per min, H2:O2 = 2: 1) for 15 min, oxygen (3 L per min) for 15 min, and H2-O2 for 120 min. The primary endpoint was inspiratory effort as assessed by diaphragm electromyography (EMGdi); the secondary endpoints were transdiaphragmatic pressure (Pdi), Borg score, vital signs, and impulse oscillometry (IOS). The concentration of H2 in the ambient environment was obtained with 12 monitors. Adverse reactions during the inhalation were recorded. RESULTS: The mean reduction in the EMGdi under H2-O2 was 10.53 ± 6.83%. The EMGdi significantly decreased during 2 H2-O2 inhalation steps (Steps 2 and 4) compared with air (Step 1) and O2 (Step 3) (52.95 ± 15.00 vs. 42.46 ± 13.90 vs. 53.20 ± 14.74 vs. 42.50 ± 14.12% for Steps 1 through 4, p < 0.05). The mean reduction in the Pdi under H2-O2 was 4.77 ± 3.51 cmH2O. Breathing H2-O2 significantly improved the Borg score and resistance parameters of IOS but not vital signs. No adverse reactions occurred. H2 was undetectable in the environment throughout the procedure. CONCLUSIONS: Breathing H2-O2 may reduce the inspiratory effort in patients with acute severe tracheal stenosis and can be used for this purpose safely.

10.
J Colloid Interface Sci ; 537: 716-724, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30448201

RESUMO

Carbon materials doped with heteroatoms are a class of cost-effective and stable electrocatalysts for oxygen reduction reactions (ORR), whose activities are mainly based on the heteroatom-related active sites. Besides the widely reported one-dimensional carbon nanotubes and two-dimensional graphene materials, carbon dots (CDs), as a new kind of zero-dimensional carbon materials, exhibit a range of unique structures and promising catalytic activities for ORR. In order to optimize the complex conditions of carbon-based catalysts, composites consisting of doped CDs and reduced graphene oxide (rGO) (designated as CD/rGO) are prepared hydrothermally, in comparison with directly doped rGO. All produced composites outperform their corresponding directly doped rGO counterparts in ORR measurements. It is noted that nitrogen and sulfur co-doped samples perform better than those doped by individual N or S. Mechanistic relationships between the ORR catalytic activities and the catalyst features are proposed, including type, location, bonding, fraction and synergistic effects of dopants, as well as the composition and structure of the carbon substrates. It is apparent that doping heteroatoms and constructing carbon substrates play a synergistic role in yielding high-performance carbon based catalysts.

11.
Int J Chron Obstruct Pulmon Dis ; 13: 3031-3044, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30319251

RESUMO

Background: Spirometry confers limited value for identifying small-airway disorders (SADs) in early-stage COPD, which can be detected with impulse oscillometry (IOS) and endobronchial optical coherence tomography (EB-OCT). Whether IOS is useful for reflecting small-airway morphological abnormalities in COPD remains unclear. Objectives: To compare the diagnostic value of spirometry and IOS for identifying SADs in heavy-smokers and COPD based on the objective assessment with EB-OCT. Methods: We recruited 59 COPD patients (stage I, n=17; stage II, n=18; stage III-IV, n=24), 26 heavy-smokers and 21 never-smokers. Assessments of clinical characteristics, spirometry, IOS and EB-OCT were performed. Receiver operation characteristic curve was employed to demonstrate the diagnostic value of IOS and spirometric parameters. Results: More advanced staging of COPD was associated with greater abnormality of IOS and spirometric parameters. Resonant frequency (Fres) and peripheral airway resistance (R5-R20) conferred greater diagnostic values than forced expiratory volume in one second (FEV1%) and maximal (mid-)expiratory flow (MMEF%) predicted in discriminating SADs in never-smokers from heavy-smokers (area under curve [AUC]: 0.771 and 0.753 vs 0.570 and 0.558, respectively), and heavy-smokers from patients with stage I COPD (AUC: 0.726 and 0.633 vs 0.548 and 0.567, respectively). The combination of IOS (Fres and R5-R20) and spirometric parameters (FEV1% and MMEF% predicted) contributed to a further increase in the diagnostic value for identifying SADs in early-stage COPD. Small airway wall area percentage (Aw% 7-9), an EB-OCT parameter, correlated significantly with Fres and R5-R20 in COPD and heavy-smokers, whereas EB-OCT parameters correlated with FEV1% and MMEF% in advanced, rather than early-stage, COPD. Conclusions: IOS parameters correlated with the degree of morphologic abnormalities of small airways assessed with EB-OCT in COPD and heavy-smokers. Fres and R5-R20 might be sensitive parameters that reliably reflect SADs in heavy-smokers and early-stage COPD.


Assuntos
Obstrução das Vias Respiratórias/diagnóstico por imagem , Bronquíolos/diagnóstico por imagem , Oscilometria/métodos , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Espirometria/métodos , Tomografia de Coerência Óptica/métodos , Idoso , Resistência das Vias Respiratórias/fisiologia , Área Sob a Curva , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Doença Pulmonar Obstrutiva Crônica/patologia , Curva ROC , Sensibilidade e Especificidade , Índice de Gravidade de Doença
12.
Dalton Trans ; 47(33): 11554-11562, 2018 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30080210

RESUMO

Carbon nanotubes with encapsulated Co nanospheres (Co@CNTs) were prepared via a simple approach that exhibits promising control over the morphology and size distribution. The individual CNTs interweave with each other and form a three-dimensional network structure. Test results indicate that the presence of polarized interfaces between the Co spheres and CNTs, as well as an excellent impedance match, leads to a superior performance in electromagnetic wave absorption. A maximum reflection loss of -70.8 dB at 6.24 GHz is obtained for a paraffin containing a 30 wt% Co@CNT inclusion. In addition, the effective absorption bandwidth (with a reflection loss below -10 dB) is 12.95-17.7 GHz at a thickness of 1.9 mm, covering most Ku bands. In particular, such Co@CNT structures demonstrate superior and sustainable electromagnetic wave-absorption properties even in contact with concentrated acid or base, owing to their specific encapsulated structure. These findings could provide new guidelines for the preparation and employment of promising microwave absorption materials that can work under harsh environments through a simple and feasible strategy.

13.
Acta Biomater ; 79: 23-36, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30149212

RESUMO

Magnesium (Mg) and its alloys have become a research frontier in biodegradable materials owing to their superior biocompatibility and excellent biomechanical compatibility. However, their high degradation rate in the physiological environment should be well tackled prior to clinical applications. This review summarizes the latest progress in the development of polymeric coatings on biodegradable Mg alloys over the last decade, regarding preparation strategies for polylactic acid (PLA), poly (latic-co-glycolic) acid (PLGA), polycaprolactone (PCL), polydopamine (PDA), chitosan (CS), collagen (Col) and their composite, and their performance in terms of corrosion resistance and biocompatibility. Feasible perspectives and developing directions of next generation of polymeric coatings with respect to biomedical Mg alloys are briefly discussed. STATEMENT OF SIGNIFICANCE: Magnesium (Mg) and its alloys have become a research frontier in biodegradable materials owing to their superior biocompatibility and suitable biomechanical compatibility. However, the principal drawback of Mg-based implants is their poor corrosion resistance in physiological environments. Hence, it is vital to mitigate the degradation/corrosion behavior of Mg alloys for safe biomedical deployments. This review summarizes the latest progress in development of polymeric coatings on biomedical Mg alloys regarding preparation strategy, corrosion resistance and biocompatibility, including polylactic acid (PLA), poly (latic-co-glycolic) acid (PLGA), polycaprolactone (PCL), chitosan (CS), polydopamine (PDA), collagen (Col) and their composite. In addition, functionalized polymer coatings with Mg alloys exhibits a promising prospect owing to their ability of degradation along with biocompatibility, self-healing, drug-delivery and osteoinduction.


Assuntos
Ligas/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Magnésio/farmacologia , Polímeros/farmacologia , Corrosão , Humanos
14.
Bioact Mater ; 3(1): 110-117, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29744448

RESUMO

High corrosion kinetics and localised corrosion progress are the primary concerns arising from the clinical implementation of magnesium (Mg) based implantable devices. In this study, a binary Mg-lithium (Li) alloy consisting a record high Li content of 14% (in weight) was employed as model material aiming to yield homogenous and slow corrosion behaviour in a simulated body fluid, i.e. minimum essential medium (MEM), in comparison to that of generic Mg alloy AZ31 and biocompatible Mg-0.5Zn-0.5Ca counterparts. Scanning electron microscopy examination reveals single-phase microstructural characteristics of Mg-14Li (ß-Li), whilst the presence of insoluble phases, cathodic to α-Mg matrix, in AZ31 and Mg-0.5Zn-0.5Ca. Though slight differences exist in the corrosion kinetics of all the specimens over a short-term time scale (no longer than 60 min), as indicated by potentiodynamic polarisation and electrochemical impedance spectroscopy, profound variations are apparent in terms of immersion tests, i.e. mass loss and hydrogen evolution measurements (up to 7 days). Cross-sectional micrographs unveil severe pitting corrosion in AZ31 and Mg-0.5Zn-0.5Ca, but not the case for Mg-14Li. X-ray diffraction patterns and X-ray photoelectron spectroscopy confirm that a compact film (25 µm in thickness) consisting of lithium carbonate (Li2CO3) and calcium hydroxide was generated on the surface of Mg-14Li in MEM, which contributes greatly to its low corrosion rate. It is proposed therefore that the single-phase structure and formation of protective and defect-free Li2CO3 film give rise to the controlled and homogenous corrosion behaviour of Mg-14Li in MEM, providing new insights for the exploration of biodegradable Mg materials.

15.
Anal Sci ; 34(3): 291-296, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29526895

RESUMO

Cationic poly-diallyldimethylammonium (PDADMAC), green CdTe quantum dots (QDs) or red CdS coated CdTe QDs, and anionic polyacrylic acid (PAA) were respectively assembled on the nano-carrier SiO2 to prepare green fluorescence composite nanoparticles (GF-QDs) and red ones (RF-QDs) with the structure SiO2/PDADMAC/QD/PDADMAC/PAA. The sandwich structure "PDADMAC/QD/PDADMAC" on the nano-carrier not only realized the protection to fluorescence of QDs but also avoided the fluorescence shielding of silica shell for the assembled QDs. In 7 days, the diluent solutions of GF-QD and RF-QD all have a very stable fluorescence. On the contrary, the fluorescence of diluent solutions of red and green QDs reduced by 75.99 and 94.35%, respectively. Indeed, they have not fluorescent shielding and have a very slight fluorescent enhancement. Based on GF-QD and RF-QD, the simultaneous determination of Hepatitis B e antigen and surface antigen has been established. Their determination in buffer and plasma all showed good precision and accuracy.


Assuntos
Antígenos de Superfície da Hepatite B/análise , Antígenos E da Hepatite B/análise , Polieletrólitos/química , Pontos Quânticos/química , Dióxido de Silício/química , Espectrometria de Fluorescência/métodos , Cor , Antígenos de Superfície da Hepatite B/química , Antígenos E da Hepatite B/química
16.
ACS Appl Mater Interfaces ; 10(2): 1810-1818, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29257665

RESUMO

In this research, we provide a simple but sound solution to address the low performance of lithium-ion batteries through preparation of wurtzite Cu9Sn2Se9 nanoparticles with uniform size distribution and morphology via a hot injection colloidal approach as a promising anode material. The Cu9Sn2Se9 nanoparticles anode exhibits superior rate performance and high reversible capacity of 979.8 mAh g-1 in the 100th cycle at a current density of 100 mA g-1, which is approximate 2 times of reported Cu-Sn-S framework (563 mA g-1), 1.5 times of reported pristine Cu2SnS3 (621 mA g-1) and comparable or higher than a number of reported Sn-based nanocomposites based anodes for lithium-ion batteries at the same cycle. The study demonstrate such outstanding properties are attributed to the high structural flexibility of the metal selenide and increased electronic connectivity by colloidal quantum dot ligand exchange procedure associated with mercaptopropionic acid (MPA). In addition, unlike most metal sulfides or selenides, it possesses a stepwise intercalation mechanism during the lithiation/delithiation cycles which is beneficial to buffer against volume variation of the alloy electrode materials. Such findings provide a new and feasible insight into guide the design and manufacturing of high performance lithium-ion batteries for a broad variety of engineering applications.

17.
J Surg Res ; 211: 53-63, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501131

RESUMO

BACKGROUND: Liver resection or partial hepatectomy (PH) is still the most commonly used therapeutic option for hepatocellular carcinoma (HCC) at present. However, the impaired regenerative ability induced by the accompanied liver cirrhosis is an important risk factor of posthepatectomy liver failure, and posthepatectomy liver failure is a feared complication that accounts for up to 75% of mortality after extensive liver resection. MicroRNA(miR)-203 is a tumor suppressor of HCC and may act as a positive intermediary in A20-enhanced interleukin (IL-6)/signal transducer and activator of transcription 3 (STAT3) pro-proliferative signals, which may promote liver regeneration after PH. However, its direct pro-proliferative effect on cirrhotic liver after hepatectomy is unknown. MATERIALS AND METHODS: Liver cirrhosis was induced by intraperitoneal injection of 50% CCl4-olive oil solution in adult male Wistar rat. Rats with liver cirrhosis received portal vein injection of physiological saline, miR-203 lentivirus, or control empty lentivirus, and then 70% PH was performed under ether anesthesia 7 d later. Liver samples were harvested at 0, 24, 36, and 72 h after 70% PH. Hepatic expressions of cyclin D1 and Ki67 were checked to evaluate the liver regenerative ability. Hepatic expressions of IL-6, suppressor of cytokine signaling 3 (SOCS3), and phospho-STAT3 were also tested to clarify the mechanisms of miR-203 in liver regeneration. RESULTS: The regeneration of miR-203 overexpression cirrhotic liver after 70% PH was enhanced and peaked at 24 and 36 h after 70% PH. The cyclin D1-positive liver cells/high-power field (HPF) in miR-203 overexpression liver markedly increased at 24 and 36 h after 70% PH compared with 0-h samples. When comparing with the control groups, cyclin D1-positive liver cells/HPF in miR-203 overexpression liver were also significantly increased at 24 and 36 h after 70% PH. A similar result of the Ki67-positive liver cells/HPF was achieved at 36 h after 70% PH. The hepatic expression of IL-6 showed a rising tendency after 70% PH, and the levels of IL-6 are significantly higher in miR-203 overexpression livers. Hepatic expression of SOCS3 was negatively expressed with hepatic miR-203 expression level, and the reduced expression of SOCS3 facilitated the phosphorylation of STAT3. CONCLUSIONS: By targeting SOCS3 and then enhancing proliferating IL-6/STAT3 signaling pathway, hepatic overexpression of miR-203 can facilitate the initiation of liver regeneration and enhance the potency of liver regeneration after 70% PH in cirrhotic rat. Together with the tumor suppressive effect on HCC, miR-203 would be an ideal candidate for promoting liver regeneration in HCC patients undergoing liver resection without the risk of tumorigenesis or cancer recurrence.


Assuntos
Hepatectomia , Cirrose Hepática/cirurgia , Regeneração Hepática/fisiologia , MicroRNAs/metabolismo , Animais , Biomarcadores/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática/fisiopatologia , Masculino , Período Pós-Operatório , Distribuição Aleatória , Ratos , Ratos Wistar
18.
ACS Appl Mater Interfaces ; 9(21): 18046-18053, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28513141

RESUMO

In this research, we reported the synthesis of quaternary Cu3InSnSe5 nanoparticles with uniform size distribution and morphology for the first time through delicate controls over the chemical reaction kinetics. On the basis of the preparation strategy of Cu3InSnSe5 nanoparticles, Pt-Cu3InSnSe5 and Au-Cu3InSnSe5 heteronanostructures were designed and yielded using a simple and efficient seed growth method. These two heteronanostructures remained monodispersed without presence of any Cu3InSnSe5 nanocrystal impurities. To explore their application potentials for dye-sensitized solar cells, counter electrodes consisting of individual Cu3InSnSe5, Pt-Cu3InSnSe5, or Au-Cu3InSnSe5 constituents were fabricated. Current density-voltage (J-V) characteristics evaluation reveals that Cu3InSnSe5 nanoparticles, Pt-Cu3InSnSe5 and Au-Cu3InSnSe5 heterostructured nanoparticles display a comparative power conversion efficiency (PCE) of 5.8%, 7.6%, and 6.5% to that of a Pt-based counter electrode (7.9%), respectively. As such, we believe that the reported preparation strategy could provide new insights to the design and manufacture of counter electrode materials with controlled structure, morphology, and optimized power conversion efficiency for dye-sensitized solar cells.

19.
Nan Fang Yi Ke Da Xue Xue Bao ; 37(3): 354-359, 2017 03 20.
Artigo em Chinês | MEDLINE | ID: mdl-28377352

RESUMO

OBJECTIVE: To investigate the relationship between miR-501-5p expression and the clinicopathological factors in patients with lung adenocarcinoma in Xuanwei area. METHODS: Surgical specimens of lung adenocarcinoma and paired adjacent tissues from 24 patients with lung adenocarcinoma from Xuanwei area were examined for miR-501-5p expression using microRNA microarray technique and qPCR. Chi-square test was used to analyze the association of miR-501-5P expression with the clinicopathological characteristics of the patients. Multiple regression analysis was performed to analyze the association of miR-501-5p expression with the patients' gender, age, tumor stage, and preoperative CEA level. RESULTS: MicroRNA microarray analysis and qPCR validation results revealed significantly upregulated expressions of miR-501-5p in patients with lung adenocarcinoma from Xuanwei area (Plt;0.01). The microarray data showed an up-regulation of miR-501-5p by 3.17 folds in lung adenocarcinoma tissue compared with the adjacent tissue (P=0.22376, FDR=0.071395). Chi-square test indicated that miR-501-5p expression level was associated with the patients' age (f=7.168, P=0.014), TNM stage (f=36.627, P<0.01), and preoperative serum CEA level (f=30.045, Plt;0.01), but not with the patients' gender (f=3.612, P=0.071). Multiple regression analysis revealed that miR-501-5p expression was positively correlated with the patients' age, TNM stage of the tumor, and serum CEA (Plt;0.05). CONCLUSION: miR-501-5p expression is up-regulated in lung adenocarcinoma with significant associations with the patients' age, TNM stages and serum CEA level in patients from Xuanwei area, suggesting its potential role in the tumorigenesis and progression of lung adenocarcinoma in Xuanwei area.


Assuntos
Adenocarcinoma/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Adenocarcinoma de Pulmão , China , Regulação Neoplásica da Expressão Gênica , Humanos , Estadiamento de Neoplasias
20.
Cancer Sci ; 108(3): 338-346, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28100026

RESUMO

Liver resection is still the most commonly used therapeutic treatment for hepatocellular carcinoma (HCC), and liver regeneration promotes HCC growth in the regenerating liver. The high recurrence/metastasis of HCC is the main cause of death for HCC patients after liver resection. However, how the augmented growth and metastasis of residual HCC induced by the promoted liver regeneration following liver resection can be abolished remains unclear. In this study, a rat model with liver cirrhosis and diffused HCC was established by administration of diethylnitrosamine. Recombinant miR-203 adenovirus was administered to induce hepatic miR-203 overexpression and 30% partial hepatectomy (PH) followed. The effect of miR-203 on the proliferation, invasion and metastasis of the residual HCC in the remnant cirrhotic liver with promoted regeneration was investigated. We found that the basic spontaneous regeneration of the non-tumorous liver by 30% PH promoted proliferation, invasion and lung metastasis of the hepatic residual HCC. miR-203 overexpression further promoted the regeneration of the non-tumorous liver by upregulating Ki67 expression and enhancing IL-6/SOCS3/STAT3 pro-proliferative signals. Importantly, miR-203 overexpression markedly inhibited the proliferation, invasion and metastasis of hepatic residual HCC through suppressing expression of Ki67, CAPNS1 and lung metastasis. Moreover, it was found that miR-203 overexpression reversed the epithelial-mesenchymal transition induced by hepatectomy through targeting IL-1ß, Snail1 and Twist1. In conclusion, our results suggested that miR-203 overexpression inhibited the augmented proliferation and lung metastasis of the residual HCC induced by the promoted liver regeneration following PH partly by regulating epithelial-mesenchymal transition.


Assuntos
Carcinoma Hepatocelular/genética , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Neoplasias Hepáticas/genética , MicroRNAs/genética , Animais , Calpaína/biossíntese , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Dietilnitrosamina/toxicidade , Hepatectomia , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Antígeno Ki-67/biossíntese , Fígado/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Masculino , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica/genética , Recidiva Local de Neoplasia/genética , Ratos , Ratos Wistar , Fator de Transcrição STAT3/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Proteína 1 Relacionada a Twist/metabolismo
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