Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Front Oncol ; 13: 1180735, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37469402

RESUMO

Background: Small cell lung cancer (SCLC) constitutes 15% of all lung cancer cases, with a comparatively low survival rate. The advent of immune checkpoint inhibitors (ICIs) has provided new alternatives for treating SCLC. However, the effectiveness of camrelizumab in the treatment of SCLC remains unclear. This retrospective case series was designed to investigate the efficacy and safety of camrelizumab in SCLC patients. Methods: The study enrolled SCLC patients recorded as having received more than one cycle of camrelizumab in the electronic medical record system. Data related to clinical and survival times were collected and statistically analyzed. Results: From August 2019 to December 2021, the study enrolled 12 SCLC patients. The objective response rate was 41.7% (95% confidence interval [CI]: 15.2%-72.3%). The disease control rate was 83.3% (95% CI: 51.6%-97.9%). The median progression-free survival (PFS) for all patients was 4.0 months. Notably, the median PFS of patients in third- or post-third-line subgroups was 7 months (95% CI: 1.12-12.88 months). The median overall survival (OS) for all eligible patients was 10.0 months (95% CI: 7.35-12.65 months), with a 1-year survival rate of 25%. Notably, the OS of patients treated with third- or post-third-line therapy was 5-34 months, with a 1-year survival rate of 75%. The two most prevalent non-hematological adverse events associated with the immune response were pneumonitis (44.4%) and reactive cutaneous capillary endothelial proliferation (44.4%). One patient experienced an exacerbation of preexisting diabetes and reached grade 3 hyperglycemia. There were no grade 4/5 immune-related adverse events. Conclusion: This case series highlights the potential benefits and safety concerns of camrelizumab in SCLC patients. These findings suggest a possible strategy for third- and post-third-line treatments of SCLC. However, the conclusion is limited due to the study's retrospective nature and small sample size. Therefore, large-scale randomized controlled studies are needed to determine its efficacy.

2.
Int J Clin Pract ; 2022: 3429462, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35855055

RESUMO

Statins are suggested to improve cancer survival by possible anti-inflammatory effect. However, it remains unclear if concomitant use of statins could improve the efficacy of immune checkpoint inhibitors (ICIs) in patients with non-small-cell lung cancer (NSCLC). Accordingly, a meta-analysis was performed to systematically evaluate the effect of concomitant statins in NSCLC patients receiving ICIs. Relevant studies were obtained by literature search in PubMed, Embase, and Web of Science databases. A conservative random-effect model was used to combine the results. Eight cohorts including 2382 patients were included. The programmed death-1/ligand-1 inhibitors were used in seven studies; while the cytotoxic T-lymphocyte-associated protein 4 inhibitors were used in the other study. It was shown that concomitant use of statin did not significantly affect the progression-free survival (PFS, hazard ratio (HR): 0.86, 95% confidence interval (CI): 0.70 to 1.07, P=0.17; I 2 = 62%) or overall survival (OS, HR: 0.86, 95% CI: 0.74 to 1.01, P=0.07; I 2 = 29%) of NSCLC patients receiving ICIs. Subgroup analyses showed consistent results in studies with univariate or multivariate analytic models (P for subgroup analysis = 0.97 and 0.38 for the outcome of PFS and OS, respectively). In conclusion, concomitant use of statin seemed to have no significant influence on the survival of patients with NSCLC who were treated with ICIs.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Inibidores de Hidroximetilglutaril-CoA Redutases , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico
3.
Materials (Basel) ; 15(8)2022 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-35454619

RESUMO

Under the background of climate change, the steel industry is considered one of the least eco-friendly industries. Flax fiber-reinforced polymer (FFRP) is an emerging sustainable alternative to steel reinforcement bar; however, its application is much restricted due to its interior material properties. This paper proposed a novel way to form closed-shape stirrups with FFRP, which is suitable for replacing steel stirrups. A multi-disciplinary investigation was conducted concerning the structural and environmental performance of FFRP stirrups in reinforced concrete (RC) beams. Seven specimens were tested under a three-point bending load. The FFRP stirrups substantially increased the shear capacity and ultimate vertical displacement by 77% and 74%, respectively, and shifted brittle failure to ductile failure. The closed-shape stirrups avoided the stress concentration and increased the utilization of FFRP tensile capacity to over 80%. Decreasing the spacing of FFRP stirrups effectively increased the shear capacity and ductility; increasing the width or layer of FFRP stirrups improved ductility only. A life cycle assessment (LCA) was later performed to evaluate and compare the environmental performance of steel, FFRP, and carbon FRP stirrups. As compared to carbon FRP and steel ones, FFRP stirrups substantially decreased the global warming and fossil depletion potential by over 60%. The main contributors to the environmental impacts of FFRP stirrups were the heavy metal released into the water and terrestrial environment during the cultivation process.

4.
Front Public Health ; 10: 1101799, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36605233

RESUMO

In China, border cities are developing in the direction of trade, investment, tourism, and regional diversification and becoming crucial for the national opening-up strategy and inter-regional exchange. In this study, we construct a comprehensive system for measuring and evaluating the resilience of border cities in China that also reveals the spatial and temporal characteristics of resilience. Three representative sample zones (Northeast, Northwest, and Southwest) are selected within the three major regions of China to analyze the regional differences in border city resilience and propose targeted coping strategies. The findings of this study are as follows. First, the spatial distribution of resilience in Chinese border cities varies significantly, with the overall resilience decreasing in the following order: Northeast China > Southwest China > Northwest China > North China > Tibetan China. Higher resilience of border cities is predominantly related to better economic foundations and advantages in border trade. Second, the resilience of China's border cities has increased significantly over the past decade, with highly resilient border cities concentrated in the northeastern part of China, the northern part of Xinjiang, and Guangxi Province. Moreover, high resilience generally spreads to surrounding low-resilience cities over time. Third, the spatial distribution and development trends of resilience levels differ among the three sample zones. Therefore, it is crucial to improve urban resilience according to the regional characteristics of each border city and its specific developmental stage.


Assuntos
População do Leste Asiático , Investimentos em Saúde , Humanos , Cidades , China
5.
Mikrochim Acta ; 188(3): 74, 2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-33558967

RESUMO

The architecture of PO43- modified 2D TiO2 nanosheets was constructed by ionic liquids (ILs)-assisted hydrothermal method. The nanosheet structure can be regulated by the addition of different amount of ionic liquid. Using the composite nanosheets  a chemoresistive gas sensor was prepared for trimethylamine (TMA) detection. Most reported TMA sensors need to be operated at a relatively high operating temperature, but in this paper, the as-synthesized PO43--modified 2D TiO2/Ti2O(PO4)2 nanosheet sensor has high response (S = 87.46), short response time (14.6 s), and good reproducibility to 100 ppm TMA gas, when the temperature is 170 °C. In contrast to the single-phase TiO2 sensor, the gas-sensing property of the composite one is obviously enhanced. Moreover, its response shows excellent linear relationship with TMA concentration from 0.2 to 500 ppm, and a detection limit of 0.2 ppm. The TMA detection mechanism was investigated by analyzing the changes of the surface adsorption oxygen content by XPS and gaseous products using gas chromatography after the sensor was in contact with TMA.


Assuntos
Poluentes Atmosféricos/análise , Líquidos Iônicos/química , Metilaminas/análise , Nanoestruturas/química , Fosfatos/química , Titânio/química , Adsorção , Poluentes Atmosféricos/química , Gases/análise , Gases/química , Imidazóis/química , Limite de Detecção , Metilaminas/química , Oxirredução , Oxigênio/química , Fosfatos/síntese química , Espectroscopia Fotoeletrônica , Reprodutibilidade dos Testes , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
6.
Materials (Basel) ; 13(1)2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31948090

RESUMO

Steel corrosion is considered as the main factor for the insufficient durability of concrete structures, especially in the marine environment. In this paper, to further inhibit steel corrosion in a high chloride environment and take advantage of the dual-functional carbon fiber reinforced polymer (CFRP), the impressed current cathodic protection (ICCP) technique was applied to the hybrid-reinforced concrete beam with internally embedded CFRP bars and steel fiber reinforced polymer composite bar (SFCB) as the anode material while the steel bar was compelled to the cathode. The effect of the new ICCP system on the flexural performance of the hybrid-reinforced concrete beam subjected to corrosion was verified experimentally. First, the electricity-accelerated precorrosion test was performed for the steel bar in the hybrid-reinforced beams with a target corrosion ratio of 5%. Then, the dry-wet cycles corrosion was conducted and the ICCP system was activated simultaneously for the hybrid-reinforced concrete beam for 180 days. Finally, the three-point bending experiment was carried out for the hybrid-reinforced concrete beams. The steel bars were taken out from the concrete to quantitatively measure the corrosion ratio after flexural tests. Results showed that the further corrosion of steel bars could be inhibited effectively by the ICCP treatment with the CFRP bar and the SFCB as the anode. Additionally, the ICCP system showed an obvious effect on the flexural behavior of the hybrid-reinforced concrete beams: The crack load and ultimate load, as well as the stiffness, were enhanced notably compared with the beam without ICCP treatment. Compared with the SFCB anode, the ICCP system with the CFRP bar as the anode material was more effective for the hybrid-reinforced concrete beam to prevent the steel corrosion.

7.
J Hazard Mater ; 385: 121570, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-31753669

RESUMO

Hierarchical and heterogeneous CuO/NiO nanowall arrays were in situ grown on ceramic tubes via a facile template-free hydrothermal route, and then were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption techniques. The resultant composites exhibit network-like CuO/NiO array structures constructed by interconnected porous nanosheets, in which the decoration of CuO nanoparticles in NiO nanowall arrays was confirmed by XRD, XPS and TEM analyses. The 2.84 at % CuO decorated NiO sensor exhibits excellent sensing properties at 133 °C. The response to 5 ppm H2S attains 36.9, which increases as high as 5.6 times compared to the NiO one. The detection limit to H2S is further decreased from 1 ppb for the pure NiO sensor to 0.5 ppb. The CuO/NiO sensor shows a wide linear range from 50 to 1000 ppb, good repeatability, selectivity and long-term stability, which is expected to be a candidate for ppb-level H2S detection in real and complex environment of industrial production. Furthermore, the dominant H2S sensing mechanism is discussed from the view of the homo- and hierarchical architecture of the CuO/NiO arrays as well as the chemical and electronic sensitization effects of CuO decoration.

8.
Am J Physiol Cell Physiol ; 316(4): C481-C491, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30673304

RESUMO

The inadequate trophoblast invasion is associated with the development of preeclampsia (PE). Considering that annexin A4 (ANXA4) enhances tumor invasion, we aimed to explore the functional role of ANXA4 in trophoblast cells and to examine the underlying mechanism. ANXA4 expression in PE placentas was analyzed using immunohistochemistry and Western blotting. Cell proliferation, invasion, and apoptosis were determined using a MTT assay, Transwell assay, and flow cytometry, respectively. The expression levels of matrix metalloproteinase (MMP)-2, MMP-9, phosphoinositide 3-kinase (PI3K), Akt, phosphorylated (p)-Akt, and phosphorylated endothelial nitric oxide synthase (p-eNOS) were detected by Western blotting. Placentas were prepared for pathological examination using hematoxylin and eosin staining and apoptosis determination using the TUNEL method. Expression of ANXA4, PI3K, p-Akt and p-eNOS was downregulated in human PE placentas and PE placenta-derived extravillous cytotrophoblasts (EVCTs). Furthermore, ANXA4 overexpression promoted cell proliferation and invasion, inhibited cell apoptosis, and upregulated protein expression of PI3K, p-Akt, and p-eNOS in human trophoblast cells HTR-8/SVneo and JEG-3. By contrast, ANXA4 knockdown exerted the opposite effects. Furthermore, inhibition of the PI3K/Akt pathway by LY294002 abrogated the ANXA4 overexpression-mediated effects on trophoblast behavior. Furthermore, eNOS knockdown abrogated the ANXA4 overexpression-induced promotion of cell invasion and MMP2/9 expression. Additionally, in N-nitro-l-arginine methyl ester (l-NAME)-induced PE rats, ANXA4 overexpression alleviated PE progression, accompanied by an increase in expression of PI3K, p-Akt, and p-eNOS in rat placentas. Our findings demonstrate that ANXA4 expression is downregulated in PE. ANXA4 may promote trophoblast invasion via the PI3K/Akt/eNOS pathway.


Assuntos
Anexina A4/biossíntese , Óxido Nítrico Sintase Tipo III/biossíntese , Fosfatidilinositol 3-Quinases/biossíntese , Pré-Eclâmpsia/metabolismo , Proteínas Proto-Oncogênicas c-akt/biossíntese , Trofoblastos/metabolismo , Animais , Células Cultivadas , Feminino , Humanos , Pré-Eclâmpsia/patologia , Gravidez , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Trofoblastos/patologia
9.
Materials (Basel) ; 11(10)2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30347761

RESUMO

This paper presents the development of a novel, multifunctional, floatable, lightweight cement composite (FLCC) using three different types of glass microspheres for structural engineering applications. Eight different mixtures of FLCC were produced and their matrix-related parameters were examined experimentally by adopting different types of microsphere fillers, fiber content (polyethylene fibers (PE)), and water-to-binder ratios. Along with the mechanical properties such as compressive, flexural, tensile strengths, and modulus of elasticity, the water tightness of the material was evaluated by sorptivity measurements and the energy efficiency by thermal conductivity. The optimal FLCC has an oven-dry density of 750 kg/m³, compressive strength (fcm) up to 41 MPa after 28-day moist curing, low thermal conductivity of 0.152 W/mK, and very low sorptivity. It is found that an optimized amount of PE fiber is beneficial for improving the tensile resistance and ductility of FLCC while a relatively large amount of microspheres can increase the entrapped air voids in the FLCC matrix and reduce its density and thermal conductivity. Microstructural analysis by scanning electron microscopy (SEM) reveals that the microspheres are distributed uniformly in the cement matrix and are subjected to triaxial compression confinement, which leads to high strength of FLCC. Segregation due to density difference of FLCC ingredients is not observed with up to 60% (by weight) of glass microspheres added. Compared to the other lightweight aggregate concretes, the proposed FLCC could be used to build floating concrete structures, insulating elements, or even load-bearing structural elements such as floor and wall panels in which self-weight is a main concern.

10.
Sensors (Basel) ; 18(10)2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30340427

RESUMO

The realization of reducing concrete self-weight is mainly to replace ordinary aggregates with lightweight aggregates; such replacement usually comes with some intrinsic disadvantages in concrete, such as high brittleness and lower mechanical properties. However, these shortages can be effectively remedied by external confinement such as fiber reinforced polymer (FRP) jacketing. To accurately predict the stress-strain behavior of lightweight concrete with lateral confinement, it is necessary to properly understand the coupling effects that are caused by diverse aggregates types and confinement level. In this study, FRP-confined lightweight concrete cylinder with varying aggregate types were tested under axial compression. Strain gauges and linear variable displacement transducers were used for monitoring the lateral and axial deformation of specimens during the tests. By sensing the strain and deformation data for the specimens under the tri-axial loads, the results showed that the lateral to axial strain relation is highly related to the aggregate types and confinement level. In addition, when compared with FRP-confined normal weight aggregate concrete, the efficiency of FRP confinement for lightweight concrete is gradually reduced with the increase of external pressure. Replace ordinary fine aggregate by its lightweight counterparts can be significantly improved the deformation capacity of FRP-confined lightweight concrete, meanwhile does not lead to the reduction of compressive strength. Plus, this paper modified a well-established stress-strain model for an FRP-confined lightweight concrete column, involving the effect of aggregate types. More accurate expressions pertaining to the deformation capacity and the stress-strain relation were proposed with reasonable accuracy.

11.
Materials (Basel) ; 11(8)2018 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30115842

RESUMO

This paper presents the authors' newly developed hybrid ultra-high performance (HUHP) engineered cementitious composite (ECC) with steel (ST) and polyethylene (PE) fibers. From this point on it will be referred to as HUHP-ECC. The volumes of steel and PE fibers were adjusted to obtain different mechanical properties, including compressive strength, tensile, and flexural properties. We found that tensile and flexural properties, including bending strength and ductility indexes, increased with higher PE fiber amounts but reduced with the increased ST fiber volume. Notably, the compressive strength had the opposite tendency and decreased with increases in the PE volume. The ST fiber had a significantly positive effect on the compressive strength. The fluidity of HUHP-ECC improved with the increasing amount of ST fiber. The pseudo strain-hardening (PSH) values for all the HUHP-ECC mixtures were used to create an index indicating the ability of strain capacity; thus, the PSH values were calculated to explain the ductility of HUHP-ECC with different fiber volumes. Finally, the morphology of PE and ST fibers at the fracture surface was observed by an environmental scanning electron microscope (ESEM).

12.
Polymers (Basel) ; 10(8)2018 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-30960817

RESUMO

In recent years, the application of engineered cementitious composites (ECCs) in structures subjected to cyclic fatigue loading, such as highway bridges, has gained widespread attention. However, most existing ECCs do not have sufficient strength and ductility, which limits their applications, especially in highway bridge structures under high-stress. In this work, an ultra-high performance engineered cementitious composite (UHP-ECC) was configured, which had a compressive strength of approximately 120 MPa, a tensile strength of up to 12 MPa, and a tensile strain capacity of more than 8%. This paper presents a study of the fatigue performance of UHP-ECC at four different fatigue stress levels through the four-point bending test. The mid-span deflection of the specimen was monitored along with the crack opening displacement (COD) of the pure bending section at the bottom of the specimen, and the crack width. In addition, the dissipated energy was calculated at various stress levels. The progressive formation of cracks under static loading was monitored using the digital image correlation (DIC) technique. The fibers at the fractured surface of the specimens were observed and analyzed by environmental scanning electron microscopy, and the morphology of the fibers was obtained at different fatigue stress levels. Eventually, the fatigue life under different stress levels was obtained, and the relationship between the fatigue life and the stress level was established.

13.
Prenat Diagn ; 37(4): 318-322, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28152582

RESUMO

OBJECTIVE: The aim of the study was to determine the contribution and significance of maternal copy number variations (CNVs) to false-positive noninvasive prenatal testing (NIPT) trisomy results. METHODS: A total of 112 021 patients were referred for NIPT. Fetal aneuploidy testing was performed using low coverage massively parallel sequencing, and results reported as chromosome Z-scores. Copy number variation sequencing (CNV-Seq) was used to detect maternal DNA CNVs. RESULTS: Confirmatory amniocentesis and karyotyping of 563 of 781 patients (72%) receiving a positive trisomy result revealed 489 true and 74 false positives. In 6 of these 74 patients (8.1%), CNV-Seq revealed non-pathogenic maternal duplications (1.76-10.90 megabases) on the chromosome associated with the fetal trisomy. There was a strong correlation of higher Z-scores with increasing size of the maternal CNVs (R2 = 0.94). When the contribution of the maternal CNV-Seq reads to chromosome Z-scores were removed, all original Z-scores shifted to the normal range. CONCLUSIONS: Maternal CNVs can potentially contribute to a small but significant number of false-positive fetal trisomies detected by NIPT. To avoid unnecessary invasive procedures and better manage patients, we recommend that confirmatory maternal DNA sequencing is performed when the NIPT methodology used indicates a high risk of a maternal CNV. © 2017 John Wiley & Sons, Ltd.


Assuntos
Variações do Número de Cópias de DNA/genética , Doenças Fetais/diagnóstico , Diagnóstico Pré-Natal/métodos , Trissomia/diagnóstico , Adulto , Erros de Diagnóstico , Reações Falso-Positivas , Feminino , Doenças Fetais/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cariotipagem/métodos , Mães , Gravidez , Análise de Sequência de DNA/métodos , Trissomia/genética
14.
ACS Appl Mater Interfaces ; 9(2): 1661-1670, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-28009163

RESUMO

Monodisperse, hierarchical α-MoO3 hollow spheres were fabricated using a facile template-free solvothermal method combined with subsequent calcination. Various quantities of Au nanoparticles (NPs) were deposited on the α-MoO3 hollow spheres to construct hybrid nanomaterials for chemical gas sensors and their BTX sensing properties were investigated. The 2.04 wt % Au-loaded α-MoO3 sensor can detect BTX effectively at 250 °C, especially, its responses to 100 ppm toluene and xylene are 17.5 and 22.1, respectively, which are 4.6 and 3.9 times higher than those of pure α-MoO3 hollow spheres at 290 °C. Besides, Au loading decreased the response times to toluene and xylene from 19 and 6 s to 1.6 and 2 s, respectively, lowered the working temperature from 290 to 250 °C as compared with those of pure α-MoO3. The surface status of Au/α-MoO3 hollow spheres before and after contacting with toluene at 250 °C was analyzed through XPS technique. Possible oxidization product of toluene was confirmed by GC for the first time. The gas-sensing mechanism of the Au/α-MoO3 was speculated as the oxidation of toluene to water and carbon dioxide by chemisorbed oxygen and lattice oxygen. The possible reason related with improved gas-sensing properties of the Au-functionalized α-MoO3 was discussed.

15.
Polymers (Basel) ; 8(10)2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-30974652

RESUMO

The in situ application of recycled aggregate concrete (RAC) is of great significance in environmental protection and construction resources sustainability. However, it has been limited to nonstructural purposes due to its poor mechanical performance. External confinement using steel tubes and fiber-reinforced polymer (FRP) can significantly improve the mechanical performance of RAC and thus the first-ever study on the axial compressive behavior of glass FRP (GFRP)-confined RAC was recently reported. To have a full understanding of FRP-confined RAC, this paper has extended the type of FRP and presents a systematic experimental study on the axial compressive performance of carbon FRP (CFRP)-confined RAC. The mechanical properties of CFRP-confined RAC from the perspective of the failure mode, ultimate strength and strain, and stress⁻strain relationship responses were analyzed. Integrated with existing experimental data of FRP-confined RAC, the paper compiles a database for the mechanical properties of FRP-confined RAC. Based on the database, the effects of FRP type (i.e., GFRP and CFRP) and the replacement ratio of recycled coarse aggregate were investigated. The results indicated that the stress⁻stain behavior of FRP-confined RAC depended heavily on the unconfined concrete strength and the FRP confining pressure instead of the replacement ratio. Therefore, this study adopted eleven high-performance ultimate strength and strain models developed for FRP-confined normal aggregate concrete (NAC) to predict the mechanical properties of FRP-confined RAC. All the predictions had good agreement with the test results, which further confirmed similar roles played by FRP confinement in improving the mechanical properties of RAC and improving those of NAC. On this basis, this paper finally recommended a stress⁻strain relationship model for FRP-confined RAC.

16.
Luminescence ; 30(6): 867-71, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25611700

RESUMO

In this work, fluorescent carbon dots (CDs) were synthesized using a hydrothermal method with glucose as the carbon source and were surface-modified with ethylenediamine. The properties of as-prepared CDs were analyzed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), ultraviolet-visible light (UV/vis) absorption and fluorescent spectra. Furthermore, CDs conjugated with mouse anti-(human carcinoembryonic antigen) (CEA) monoclonal antibody were successful employed in the biolabeling and fluorescent imaging of human gastric carcinoma cells. In addition, the cytotoxicity of CDs was also tested using human gastric carcinoma cells. There was no apparent cytotoxicity on human gastric carcinoma cells. These results suggest the potential application of the as-prepared CDs in bioimaging and related fields.


Assuntos
Anticorpos Monoclonais/química , Etilenodiaminas/química , Corantes Fluorescentes/química , Pontos Quânticos , Neoplasias Gástricas/diagnóstico por imagem , Animais , Carbono/química , Antígeno Carcinoembrionário/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes/síntese química , Química Verde , Humanos , Camundongos , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Sondas Moleculares/química , Sondas Moleculares/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Neoplasias Gástricas/patologia
17.
J Chromatogr A ; 1348: 137-49, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-24845825

RESUMO

Multivalent pneumococcal vaccines were used worldwide to protect human beings from pneumococcal diseases. In order to eliminate the toxic organic solutions used in the traditional vaccine purification process, an alternative chromatographic process for Streptococcus pneumoniae serotype 23F capsular polysaccharide (CPS) was proposed in this study. The strategy of Design of Experiments (DoE) was introduced into the process development to solve the complicated design procedure. An initial process analysis was given to review the whole flowchart, identify the critical factors of chromatography through FMEA and chose the flowthrough mode due to the property of the feed. A resin screening study was then followed to select candidate resins. DoE was utilized to generate a resolution IV fractional factorial design to further compare candidates and narrow down the design space. After Capto Adhere was selected, the Box-Behnken DoE was executed to model the process and characterize all effects of factors on the responses. Finally, Monte Carlo simulation was used to optimize the process, test the chosen optimal conditions and define the control limit. The results of three scale-up runs at set points verified the DoE and simulation predictions. The final results were well in accordance with the EU pharmacopeia requirements: Protein/CPS (w/w) 1.08%; DNA/CPS (w/w) 0.61%; the phosphorus content 3.1%; the nitrogen 0.315% and the Methyl-pentose percentage 47.9%. Other tests of final pure CPS also met the pharmacopeia specifications. This alternative chromatographic purification process for pneumococcal vaccine without toxic organic solvents was successfully developed by the DoE approach and proved scalability, robustness and suitability for large scale manufacturing.


Assuntos
Cromatografia , Polissacarídeos Bacterianos/isolamento & purificação , Projetos de Pesquisa , Streptococcus pneumoniae/química , Método de Monte Carlo , Polissacarídeos Bacterianos/química , Sorotipagem
18.
Artigo em Inglês | MEDLINE | ID: mdl-23933844

RESUMO

Fluorescent carbon dots (CDs) were synthesized by a solvothermal method with glucose as carbon source and surface-modified with 1,6-hexamethylene diamine. In this hybrid CDs, the modification played important role for improving the fluorescent performance by introducing nitrogenous compound to passivate CD's surface, making the CDs emit strong fluorescence. The as-prepared CDs were linked with mouse anti-human Alpha fetoprotein (AFP) antibody and goat anti-mouse immunoglobulin (IgG) to directly and indirectly label fixed human hepatocellular carcinoma cells, respectively. The cytotoxicity of these CDs were also tested using the human hepatocellular carcinoma cells. No apparent cytotoxicity was observed, which suggested the potential application of the as-prepared CDs in bioimaging.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Diaminas , Corantes Fluorescentes , Neoplasias Hepáticas/diagnóstico , Pontos Quânticos , Animais , Anticorpos/química , Anticorpos/imunologia , Linhagem Celular Tumoral , Diaminas/química , Diaminas/toxicidade , Corantes Fluorescentes/química , Corantes Fluorescentes/toxicidade , Humanos , Camundongos , Pontos Quânticos/química , Pontos Quânticos/toxicidade , alfa-Fetoproteínas/imunologia
19.
Sheng Wu Gong Cheng Xue Bao ; 28(3): 358-67, 2012 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-22712394

RESUMO

In recent years, Chinese hamster ovary (CHO) production vessel volume has reached more than 1 000 L in Chinese biopharms, and 10 000 L in foreign big biopharms, such as Lonza and Genetech. In general, there are some steps seed bioreactor for seed expansion, which decreases the efficiency of production process. In this work, a perfusion-based process was developed to drastically increase the split ratio during the scale-up of CHO cell cultures. Fed-batch cultures were inoculated with cells propagated in either batch or perfusion cultures that grown in disposable Cellbags using the WAVE Bioreactor system. The higher cell concentration of 2 x 10(7) cells/mL with 95% viability allowed to increase the split ratio to about 1:50-1:100 for inoculum propagated in perfusion culture. The method described here could reduce the number of required expansion steps and eliminate two or three bioreactors. Disposable perfusion bioreactor with only a few liters working volume have the potential to directly inoculate volumes of up to 1 000 liters. This would allow to shorten process time in these bioreactors, which often are the bottleneck in plant throughput.


Assuntos
Reatores Biológicos , Células CHO/citologia , Técnicas de Cultura de Células/métodos , Animais , Técnicas de Cultura de Células/instrumentação , Cricetinae , Cricetulus
20.
Water Sci Technol ; 64(1): 162-70, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22053471

RESUMO

This paper studied the influence of the operating conditions, e.g., current density, electrolyte and exposure time, on the variation of the algal viability during electrochemical disinfection processes. An electrochemical tube employing Ti/RuO2 as anodes was constructed for inactivation of cyanobacteria (often called blue-green algae) Microcystis aeruginosa. Viability of algal cells was determined by 2,3,5-triphenyl-tetrazoliumchloride (TTC) dehydrogenase activity assay and neutral red (NR) staining assay. Algal suspensions with cell density of 5-7 x 10(9) L(-1) were exposed to current densities from 1 to 8 mA cm(-2) at room temperature (25-30 degrees C) for 30 min. The results showed that the cell viability decreased obviously with the increase of current density. After exposure to 4 mA cm(-2) for more than 7 min, Microcystis aeruginosa didn't have the ability to resume growth. Comparative disinfection tests with different electrolytes were conducted, including chlorides, sulfates, nitrates and phosphates. Microcystis aeruginosa appeared to be sensitive to electro-generated chlorine oxidants. The inactivation effect was also demonstrated to occur in chlorine-free electrolytes. However, decrease of the inactivation effect by adding ascorbic acid as an oxidant scavenger indicated that the reactive oxygen species, especially *OH radicals, played an important role for chlorine-free electrolytes.


Assuntos
Desinfecção/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Microcystis/efeitos dos fármacos , Compostos de Rutênio/química , Titânio/química , Ácido Ascórbico/química , Compostos Clorados/farmacologia , Técnicas Eletroquímicas/instrumentação , Microcystis/fisiologia , Vermelho Neutro/química , Espécies Reativas de Oxigênio/química , Sais de Tetrazólio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...