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1.
J Am Chem Soc ; 145(30): 16843-16851, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37470345

RESUMO

With the growing popularity of serine/threonine ligation (STL) and cysteine/penicillamine ligation (CPL) in chemical protein synthesis, facile and general approaches for the preparation of peptide salicylaldehyde (SAL) esters are urgently needed, especially those viable for obtaining expressed protein SAL esters. Herein, we report the access of SAL ester surrogates from peptide hydrazides (obtained either synthetically or recombinantly) via nitrite oxidation and phenolysis by 3-(1,3-dithian-2-yl)-4-hydroxybenzoic acid (SAL(-COOH)PDT). The resulting peptide SAL(-COOH)PDT esters can be activated to afford the reactive peptide SAL(-COOH) esters for subsequent STL/CPL. While being operationally simple for both synthetic peptides and expressed proteins, the current strategy facilitates convergent protein synthesis and combined application of STL with NCL. The generality of the strategy is showcased by the N-terminal ubiquitination of the growth arrest and DNA damage-inducible protein (Gadd45a), the efficient synthesis of ubiquitin-like protein 5 (UBL-5) via a combined N-to-C NCL-STL strategy, and the C-to-N semisynthesis of a myoglobin (Mb) variant.


Assuntos
Peptídeos , Proteína C , Proteínas , Cisteína , Serina , Treonina , Ésteres
2.
Molecules ; 28(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36838862

RESUMO

Metabolic-associated fatty liver disease (MAFLD) is one of the most common chronic liver diseases, which in turn triggers mild inflammation, metabolic dysfunction, fibrosis, and even cancer. Accumulating evidence has suggested that Berberine (BBR) could significantly improve MAFLD progression. Clock and Bmal1 as heterodimer proteins highly participated in the development of MAFLD, but whether BBR targets Clock and Bmal1 in MAFLD remains poorly understood. The result suggested that the protein levels of Clock and Bmal1 were decreased in MAFLD mice, which was negatively correlated with elevated reactive oxygen species (ROS) accumulation, the H2O2 level, liver inflammation, metabolic dysfunction, and insulin resistance. The mRNA and protein levels of Clock and Bmal1 were also decreased in glucosamine-induced HepG2 cells, which were are negatively related to glucose uptake, the ROS level, and the H2O2 level. More importantly, Bmal1 siRNA could mimic the effect of glucosamine in HepG2 cells. Interestingly, Berberine (BBR) could rescue metabolism disorder and redox homeostasis through enhancing Clock and Bmal1 expression in vivo and in vitro. Therefore, BBR might be an effective natural compound for alleviating redox homeostasis, metabolism disorder, and liver pathological changes in MAFLD by activating Clock and Bmal1 expression.


Assuntos
Berberina , Doenças Metabólicas , Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Fatores de Transcrição ARNTL/genética , Berberina/metabolismo , Glucosamina , Homeostase , Peróxido de Hidrogênio/metabolismo , Inflamação/metabolismo , Fígado/metabolismo , Doenças Metabólicas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Humanos , Células Hep G2
3.
Angew Chem Int Ed Engl ; 61(15): e202115377, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35060269

RESUMO

The hydrazinolysis of S-cyanylated peptide provides an alternative way to afford protein α-hydrazide, a key reagent used in native chemical ligation (NCL), without the aid of any inteins or enzymes. The currently used non-selective S-cyanylation, however, allows no other cysteine in the protein besides the one at the cleavage site. Herein, we report a regioselective S-cyanylation and hydrazinolysis strategy achieved via the fusion of a tetracysteine tag to the C-terminal of the protein of interest. We term it tetracysteine enabled protein ligation (TCEPL). While highly selective, the strategy is applicable for proteins expressed as inclusion bodies, and this was showcased by the efficient semi-synthesis of an iron-sulfur protein rubredoxin and the catalytic and hinge domains of matrix metalloprotease-14 (MMP-14) containing 207 amino acid residues. Furthermore, the TCEPL strategy was exploited for protein C-terminal labeling with amino reagents bearing a variety of functional groups, demonstrating its versatility and generality.


Assuntos
Peptídeos , Proteínas , Cisteína/química , Indicadores e Reagentes , Inteínas , Peptídeos/química
4.
Anal Biochem ; 619: 114128, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33577792

RESUMO

Rubredoxins (Rds), like those from Pyrococcus furious (Pf), have largely been found to be expressed in Escherichia coli (E. coli) as a mixture of different N-terminal forms, which may affect the properties of the protein. The typical procedures for the purification of Rds are cumbersome and usually with low yield. We present herein a streamlined purification strategy based on the reversed-phase high performance liquid chromatography (RP-HPLC), which offers high yield and high resolution after simply one-step purification following pre-treatment. We also show that RP-HPLC can be a valuable tool to gain information related to the thermal decomposition pathway of Pf-Rds.


Assuntos
Proteínas Arqueais/química , Modelos Moleculares , Processamento de Proteína Pós-Traducional , Pyrococcus furiosus/química , Rubredoxinas/química , Proteínas Arqueais/genética , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Escherichia coli/química , Escherichia coli/genética , Pyrococcus furiosus/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Rubredoxinas/genética , Rubredoxinas/isolamento & purificação
5.
Inorg Chem ; 60(18): 14364-14370, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34503329

RESUMO

Nitric oxide (NO) is an essential biological messenger, contributing a significant role in a diverse range of physiological processes. The light-controllable NO releasers are of great interest because of their potential as agents for NO-related research and therapeutics. Herein, we developed a pair of red-light-controllable NO releasers, pfRd-C9A-{FeNO}7 and pfRd-C42A-{FeNO}7 (pfRd = Pyrococcus furiosus rubredoxin), by constructing a nonheme {FeNO}7 center within the redesigned iron-sulfur protein scaffolds. While shown to be both air and thermally stable, these complexes are highly sensitive to red-light irradiation with temporal precision, which was confirmed by electron paramagnetic resonance spin trapping and Griess assay. The temporally controlled NO release from these complexes was also demonstrated in DNA cleavage assay. Overall, this study demonstrates that such a protein-based nonheme iron nitrosyl system could be a viable chemical tool for precise NO administration.


Assuntos
Ferro/metabolismo , Luz , Óxido Nítrico/metabolismo , Pyrococcus furiosus/química , Rubredoxinas/química , Ferro/química , Modelos Moleculares , Óxido Nítrico/química
6.
Environ Sci Technol ; 55(8): 4658-4668, 2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33754703

RESUMO

Microplastics (MPs) pollution has caused a threat to soil ecosystem diversity and functioning globally. Recently, an increasing number of studies have reported effects of MPs on soil ecosystems. However, these studies mainly focused on soil bacterial communities and a few limited functional genes, which is why MPs effects on soil ecosystems are still not fully understood. Fertilization treatment often coinsides with MPs exposure in practice. Here, we studied effects of an environmentally relevant concentration of polyethylene on soil properties, microbial communities, and functions under different soil types and fertilization history. Our results showed that 0.2% PE MPs exposure could affect soil pH, but this effect varied according to soil type and fertilization history. Long-term fertilization history could alter effects of MPs on soil bacterial and fungal communities in diverse farmland ecosystems (P < 0.05). Soil fungal communities are more sensitive to MPs than bacterial communities under 0.2% PE MPs exposure. MPs exposure has a greater impact on the soil ecosystem with a lower microbial diversity and functional genes abundance and increases the abundance of pathogenic microorganisms. These findings provided an integrated picture to aid our understanding of the impact of MPs on diverse farmland ecosystems with different fertilization histories.


Assuntos
Microbiota , Poluentes do Solo , Ecossistema , Fazendas , Fertilização , Microplásticos , Plásticos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
7.
Anal Chem ; 92(23): 15472-15479, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33169970

RESUMO

The rapid spread of antibiotic resistance threatens our fight against bacterial infections. Environments are an abundant reservoir of potentially transferable resistance to pathogens. However, the trajectory of antibiotic resistance genes (ARGs) spreading from environment to clinic and the associated risk remain poorly understood. Here, single-cell Raman spectroscopy combined with reverse D2O labeling (Raman-rD2O) was developed as a sensitive and rapid phenotypic tool to track the spread of plasmid-borne ARGs from soil to clinical bacteria via transformation. Based on the activity of bacteria in assimilating H to substitute prelabeled D under antibiotic treatment, Raman-rD2O sensitively discerned a small minority of phenotypically resistant transformants from a large pool of recipient cells. Its single-cell level detection greatly facilitated the direct calculation of spread efficiency. Raman-rD2O was further employed to study the transfer of complex soil resistant plasmids to pathogenic bacteria. Soil plasmid ARG-dependent transformability against five clinically relevant antibiotics was revealed and used to assess the spreading risk of different soil ARGs, i.e., ampicillin > cefradine and ciprofloxacin > meropenem and vancomycin. The developed single-cell phenotypic method can track the fate and risk of environmental ARGs to pathogenic bacteria and may guide developing new strategies to prevent the spread of high-risk ARGs.


Assuntos
Resistência Microbiana a Medicamentos/genética , Fenótipo , Análise de Célula Única/métodos , Análise Espectral Raman/métodos , Humanos , Plasmídeos/genética , Risco , Coloração e Rotulagem
8.
J BUON ; 23(6): 1656-1661, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30610791

RESUMO

INTRODUCTION: The purpose of this study was to analyze the efficacy and safety of induction chemotherapy and sequential Nimotuzumab combined with concurrent chemoradiotherapy in N3M0 stage nasopharyngeal carcinoma (NPC). METHODS: This study included 45 N3 stage NPC patients treated with induction chemotherapy, sequential Nimotuzumab plus concurrent chemoradiotherapy. The intensity modulated radiation therapy (IMRT) doses for planning target volume (PTV) were 70-72 Gy for gross disease in the nasopharynx, and 66-70 Gy for positive lymph nodes. The doses for high risk and low risk regions PTV were 60-62 Gy and 54-56 Gy in 31-33 fractions. Induction chemotherapy consisted of 3 cycles of docetaxel (75 mg/m2, day 1) plus lobaplatin (30 mg/m2, day 1). Concurrent with radiotherapy, patients received chemotherapy consisting of lobaplatin 50 mg/m2, day 1. Targeted drug therapy given on the first time of IMRT consisted of Nimotuzumab (200mg, iv weekly for 7 courses). Cycle repetition of chemotherapy was every 21 days. RESULTS: The efficacy of 3 cycles of induction chemotherapy before the start of concurrent chemoradiotherapy was 100%, and the overall efficacy after the end of chemoradiotherapy was also 100%. Three-year overall survival (OS), distant metastasis-free survival (DMFS), locoregional control (LRC) and progression-free survival (PFS) rates were 85.6, 81.9, 97.8 and 79.5%, respectively. The main adverse reactions were hematologic toxicity, particularly neutropenia (100%), anemia (88.9%) and thrombocytopenia (68.9%). Patients developed a relatively low degree of mucositis and vasculitis. Chronic toxicity was mainly grade I-II radiation-induced xerostomia (18 cases). There were 11 cases of hearing loss and 4 cases of neck skin fibrosis. No cases of treatment-related death and radiation-induced cranial nerve damage or trismus were observed. CONCLUSION: In N3 stage NPC, induction chemotherapy and sequential Nimotuzumab plus concurrent chemoradiotherapy yielded an excellent survival benefit, and the toxicities were tolerable. Distant metastasis was the main cause of treatment failure.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia/mortalidade , Quimioterapia de Indução/mortalidade , Neoplasias Nasofaríngeas/terapia , Recidiva Local de Neoplasia/terapia , Adulto , Idoso , Anticorpos Monoclonais Humanizados/administração & dosagem , Ciclobutanos/administração & dosagem , Docetaxel/administração & dosagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/patologia , Recidiva Local de Neoplasia/patologia , Compostos Organoplatínicos/administração & dosagem , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
9.
Anticancer Drugs ; 27(7): 685-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27088576

RESUMO

To evaluate the efficacy and safety of the chemotherapy program of docetaxel combined with lobaplatin for Chinese patients with pulmonary and hepatic metastasis of nasopharyngeal carcinoma (NPC). This study included 37 NPC patients with pulmonary and hepatic metastasis. The chemotherapy program included docetaxel (75 mg/m, day 1) plus lobaplatin (30 mg/m, day 1). Cycle repetition was every 21 days. Patients were monitored for 7-41 months, with a median follow-up duration of 18 months. The total efficiency of this group was 67.6% and the disease control rate was 81.1%. The median progression-free survival was 9.4 months (95% confidence interval, 6.8-14.3 months), the median overall survival was 18.3 months (95% confidence interval, 13.7-22.8 months), and the 2-year survival rate was 37.8%. The main hematological toxicities were leukopenia (91.9%), anemia (81.1%), and thrombocytopenia (70.3%); other adverse reactions were mild. Changes in Epstein-Barr-DNA levels can basically reflect the dynamic changes in the efficacy of chemotherapy. Docetaxel combined with lobaplatin has a favorable outcome for the treatment of pulmonary and hepatic metastatic NPC. It has been a convenient regimen with tolerable toxicity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Neoplasias Nasofaríngeas/tratamento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma/patologia , Ciclobutanos/administração & dosagem , Ciclobutanos/efeitos adversos , Docetaxel , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patologia , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Taxoides/administração & dosagem , Taxoides/efeitos adversos
10.
J BUON ; 21(1): 161-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27061544

RESUMO

PURPOSE: To evaluate the efficacy and safety of lobaplatin combined with docetaxel as neoadjuvant chemotherapy followed by concurrent lobaplatin with intensity-modulated radiotherapy (IMRT) for high-risk positive lymph node (N+) nasopharyngeal carcinoma (NPC). METHODS: This study enrolled 37 primary high-risk N+ NPC patients. The neoadjuvant chemotherapy program consisted of lobaplatin (30 mg/m(2), day 1) plus docetaxel (75 mg/m(2), day 1) for two cycles, 3 weeks apart. Concurrently with IMRT, patients received a chemotherapy program of lobaplatin 50mg/m(2). Cycle repetition was every 21 days. The IMRT doses were planning target volume (PTV) 68-72 Gy for gross disease in the nasopharynx, and 66-70 Gy for positive lymph nodes in 33 FRACTIONS. The doses for high risk and low risk region PTV were 59.4 Gy in 33 fractions and 50.4 Gy in 28 fractions. RESULTS: The median follow-up duration was 31 months (range 4-52). The 3-year overall survival (OS) was 74.3%. The 3-year distant metastasis-free survival (DMFS) was 67.4%. The 3-year locoregional relapse-free survival (LRFS) was 91.5%, and the 3-year progression-free survival (PFS) was 61.2%. The efficiency of short-term effects of neoadjuvant chemotherapy and chemoradiotherapy were 83.8% and 100.0%, respectively. Serious acute toxicities observed were neutropenia (97.3%), thrombocytopenia (83.8%) and anemia (81.1%). CONCLUSIONS: In patients with high-risk N+ NPC, lobaplatin combined with docetaxel neoadjuvant chemotherapy followed by concurrent lobaplatin with IMRT yielded excellent short-term results with mild and tolerable toxicities.


Assuntos
Quimiorradioterapia , Neoplasias Nasofaríngeas/terapia , Radioterapia de Intensidade Modulada , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma , Ciclobutanos/administração & dosagem , Docetaxel , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Terapia Neoadjuvante , Compostos Organoplatínicos/administração & dosagem , Taxoides/administração & dosagem
11.
J BUON ; 20(1): 206-11, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25778317

RESUMO

PURPOSE: To explore the clinical efficacy of radiotherapy combined with concurrent combination chemotherapy in the treatment of patients with advanced nasopharyngeal carcinoma (NPC). METHODS: Two hundred patients with stage III/IV NPC were randomly allocated into the treatment group (N=100) and the control group (N=100). Patients in the control group received conventional fractionated radiotherapy, while patients in the treatment group received conventional fractionated radiotherapy combined with concurrent combination chemotherapy with cisplatin and 5-fluorouracil (5-FU). Short-term efficacy, radiotherapy toxicity, shortand long-term survival were compared. RESULTS: The short-term response rate of the treatment group was 96%, which was significantly higher than that of the control group (87%, p<0.05). The local radiation toxicity of the treatment group was similar to that of the control group p>0.05), but the hematological and gastrointestinal toxicities were significantly higher in the treatment group p<0.05). The 1-, 3- and 5-year overall survival rates were 87, 80, and 76%, respectively, in the treatment group and 74, 64, and 51%, respectively, in the control group, significantly favoring the treatment group p<0.05). CONCLUSION: Radiotherapy with concurrent combination chemotherapy can improve the prognosis of patients with advanced NPC but at the cost of significant toxicity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia Adjuvante , Neoplasias Nasofaríngeas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma , Quimiorradioterapia Adjuvante/efeitos adversos , China , Cisplatino/administração & dosagem , Fracionamento da Dose de Radiação , Feminino , Fluoruracila/administração & dosagem , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Estadiamento de Neoplasias , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
12.
Materials (Basel) ; 16(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37895644

RESUMO

The interaction between low-molecular-weight organic acids (LMWOAs) and minerals in nature has been widely studied; however, limited research has been conducted on the dissolution mechanism of sillimanite in the presence of different organic acids. In this study, the interaction between the sillimanite sample and LMWOAs (citric acid, oxalic acid, and citric/oxalic mixture) at the same pH was investigated. The dissolution rate of Si and Al was high during the initial reaction time, then slowed down in the presence of LMWOAs. The dissolution data for Si and Al from sillimanite in the LMWOAs fit well with the first-order equation (Ct = a(1 - exp(-kt))) (R2 > 0.991). The dissolution process of sillimanite in the organic acids was controlled by the surface chemical reaction step. The dissolution concentration of Si in aqueous citric acid was higher than that in oxalic acid. In contrast, the dissolution concentration of Al in oxalic acid was more than that in citric acid. The maximum concentrations of Si and Al in the presence of composite organic acids were 1754 µmol/L and 3904 µmol/L. The sillimanite before and after treatment with LMWOAs were studied using X-ray diffraction (XRD) and scan electron microscopy (SEM). These results are explained by the characterization of the sillimanite. Under the single acid solution, the (210) crystal plane with a high areal density of Al in sillimanite was easily dissolved by the oxalic acid, while the (120) in sillimanite with a high areal density of Si was more easily dissolved by citric acid. In the composite organic acids, the Si-O bond and Al-O bond in sillimanite were attacked alternately, leading to the formation of some deeper corrosion pits on the surface of sillimanite. The results are of interest in the dissolution mechanisms of sillimanite in the low-molecular-weight organic acids and the environmentally friendly activation of sillimanite.

13.
Materials (Basel) ; 16(24)2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38138844

RESUMO

The modification mechanism of low-molecular-weight organic acids on a single-chain silicate mineral (wollastonite) was investigated through a leaching method. Solid and liquid samples were analyzed using atomic absorption spectrophotometer (AAS), X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR). After 720 h of reaction, the results revealed that the dissolution concentration of Si (2200 µmol/L) in citric acid solution is more than that (1950 µmol/L) in oxalic acid. In the composite acids (citric acid and oxalic acid), the dissolution concentration of Si release from wollastonite reached the maximum value of 3304 µmol/L. The dissolution data of Si in wollastonite were fittingly described by the parabolic equation (Ct = a + bt1/2), with the highest correlation coefficients (R2 > 0.993), in the presence of the low-molecular-weight organic acids. The dissolution data suggested that the dissolution reaction process of Si was consistent with the diffusion-controlled model. Citric acid exhibited a higher affinity for attacking the (200) surface, while oxalic acid was prone to dissolve the (002) crystal face. The synergistic effects of oxalic acid and citric acid led to the weakening of the XRD diffraction peak intensity of wollastonite. When exposed to composite acids, the surface of wollastonite was covered with insoluble reactants that restricted the substance diffusion and hindered the reaction. This study offers valuable theoretical insights into the modification or activation of wollastonite by composite low-molecular-weight organic acids.

14.
Materials (Basel) ; 16(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36837244

RESUMO

A high sintering temperature is required to acquire excellent performance in the production of porcelain but results in high fuel consumption. To prepare the porcelain with outstanding performance at a lower temperature, a self-produced additive containing calcium (CaK) was added into a three-component system of kaolinite-feldspar-quartz. XRD and SEM were used to characterize the samples. The toughening mechanism and Gibbs free energy were investigated. After introducing the CaK, the bending strength of the porcelain fired at 1513 K increased from 56.32 ± 0.65 MPa to 95.31 ± 0.63 MPa, which was 21.83% higher than that of the porcelain without CaK at an optimal firing temperature of 1603 K. The main crystal phase of the sample comprised mullite and quartz in the raw materials at 1453~1603 K. The anorthite was observed at 1453 K and interlocked with needle-shaped mullite at 1513 K in the porcelain after adding CaK, which resulted in the higher bending strength. Quantitative analysis indicated that the amount of anorthite decreased at 1513 K and disappeared at 1543 K; the amount of mullite increased with temperature. The Gibbs free energy of the reaction (CaO•Al2O3•2SiO2 + 2(Al2O3•2SiO2) → 3Al2O3•2SiO2 + CaO + 4SiO2) at high temperature was negative, which suggested that the formation of mullite (3Al2O3•2SiO2) from anorthite (CaO•Al2O3•2SiO2) was possible. These findings implied that the addition of CaK contributed to the appropriate phase composition and microstructure, and the excellent performance of the porcelain at a lower temperature. In addition, the transformation between anorthite and mullite was possible in the special raw material system. The results are of interest in producing anorthite/mullite ceramics at reduced sintering temperatures and the conversion between anorthite and mullite.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 286: 121934, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36242836

RESUMO

In this paper, alkali ion (Li+ Na+ K+ and Rb+)-doped Y2O3:Yb3+/Ho3+ up conversion films were prepared using the sol-gel method. The structures of the films were studied by using X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. A series of high-quality thin films with good crystallization were prepared. For all samples, two emission bands were observed: green emission at 539 (550) nm and red emission at 664 nm, which can be attributed to 5F4 (5S2)→5I7 and 5F5→5I8, respectively. The green emission is dominant, and the red emission is extremely weak. The effect of each alkali-ion dopant on the emission and color adjustment of samples was investigated. The green emission intensity is increased by a factor of 6.33 (Li), 2.03 (Na), 4.82 (K) and 1.92 (Rb) with increasing alkali-ion doping concentration, and red emission is increased by a factor of 7.80 (Li), 1.92 (Na), 4.78 (K) and 1.90 (Rb). The extreme value appears earlier with increasing ion radius. Li+ doping boosts luminescence in three ways, and the other alkali ions affect the light emission in two ways. Li+ doping and K+ doping can be used to adjust the color coordinates towards the 539 nm and 550 nm directions, respectively. Na+ and Rb+ doping can enhance emission with a stable color. This means that each alkali ion is a suitable choice as a color-regulating ion and can play a role in the regulation of luminescence.

16.
Materials (Basel) ; 16(20)2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37895686

RESUMO

Feldspar is a high-abundance mineral in the earth's crust, and its natural weathering and dissolution processes are an important phenomenon on the earth's surface. This study focused on the dissolution behavior of silicon (Si) and aluminum (Al) in feldspar minerals (microcline and albite) when exposed to low-molecular-weight organic acids (LMWOAs). Various analytical techniques, including atomic absorption spectrophotometer, X-ray diffraction, scanning electron microscope, and Fourier-transform infrared spectroscopy, were employed to investigate these processes. The results revealed that the concentration of Si and Al released from alkali feldspar increased after treatment with LMWOAs, exhibiting non-stoichiometric dissolution. The Si/Al release ratio from feldspar deviated from the expected value of three. Among the LMWOAs tested, oxalic acid was found to be more effective in dissolving aluminum, while citric acid showed greater efficacy in dissolving silicon. Notably, the composite acid demonstrated the highest capacity for feldspar dissolution, with values of 538 µM (Si) and 287 µM (Al) after treatment for 720 h, respectively. The dissolution data for Si and Al in the organic acid solution was fittingly described by a first-order equation, with high correlation coefficients (R2 ≥ 0.992). The characterization of feldspar powders indicated that the (040) crystal plane of feldspar was particularly susceptible to attack by organic acids. In the presence of these acids, the chemical bonds Si (Al)-O, Si-Si(Al), and O-Si(Al)-O shifted to higher wavenumbers. Additionally, the surface corrosion morphology of feldspar exhibited distinct nanostructures, which became more pronounced with increasing exposure time. It was also observed that the reactivity of feldspar increased over time. These findings provide valuable insights into the natural dissolution process of feldspar and offer a new perspective for the study of this phenomenon.

17.
J Cachexia Sarcopenia Muscle ; 14(2): 815-825, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36872457

RESUMO

BACKGROUND: Induction chemotherapy (IC) and concurrent chemoradiotherapy (CCRT) is the standard of care for locoregionally advanced nasopharyngeal carcinoma (LA-NPC). This intensive treatment regimen increases acute toxicities, which could negatively impact patients' nutritional status. We conducted this prospective, multicentre trial to investigate the effects of IC and CCRT on nutritional status in LA-NPC patients, so as to provide evidence for further study of nutritional intervention, which was registered in ClinicalTrials.gov (NCT02575547). METHODS: Patients with biopsy-proven NPC and planned for IC + CCRT were recruited. IC entailed two cycles of 3-weekly docetaxel 75 mg/m2 and cisplatin 75 mg/m2 ; CCRT entailed two to three cycles of 3-weekly cisplatin 100 mg/m2 depending on the duration of radiotherapy. Nutritional status and quality of life (QoL) were assessed pre-IC, post-cycles one and two of IC, W4 and W7 of CCRT. Primary endpoint was the cumulative proportion of ≥ 5.0% weight loss (WL5.0 ) by the end of treatment (W7-CCRT). Secondary endpoints included body mass index, NRS2002 and PG-SGA scores, QoL, hypoalbuminaemia, treatment compliance, acute and late toxicities and survivals. The associations between primary and secondary endpoints were also evaluated. RESULTS: One hundred and seventy-one patients were enrolled. Median follow-up was 67.4 (IQR: 64.1-71.2) months. 97.7% (167/171) patients completed two cycles of IC, and 87.7% (150/171) completed at least two cycles of concurrent chemotherapy; all, except one patient (0.6%), completed IMRT. WL was minimal during IC (median of 0.0%), but increased sharply at W4-CCRT (median of 4.0% [IQR: 0.0-7.0%]) and peaked at W7-CCRT (median of 8.5% [IQR: 4.1-11.7%]). 71.9% (123/171) of patients recorded a WL5.0 by W7-CCRT, which was associated with a higher malnutrition risk (NRS2002 ≥ 3 points: 87.7% [WL ≥ 5.0%] vs 58.7% [WL < 5.0%], P < 0.001) and requirement of nutritional intervention (PG-SGA ≥ 9 points: 82.0% [WL ≥ 5.0%] vs 66.7% [WL < 5.0%], P = 0.038). The median %WL at W7-CCRT was higher in patients who suffered from ≥ G2 mucositis (9.0% vs 6.6%, P = 0.025) and xerostomia (9.1% vs 6.3%, P = 0.003). Besides, patients with cumulative WL5.0 also reported a higher detriment on QoL at W7-CCRT compared with patients without, with a difference of -8.3 points (95% CI [-15.1, -1.4], P = 0.019). CONCLUSIONS: We observed a high prevalence of WL among LA-NPC patients who were treated with IC + CCRT, which peaked during CCRT, and had a detriment on patients' QoL. Our data support the need to monitor patient's nutritional status during the later phase of treatment with IC + CCRT and inform on nutritional intervention strategies.


Assuntos
Neoplasias Nasofaríngeas , Estado Nutricional , Humanos , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/radioterapia , Estudos Prospectivos , Qualidade de Vida , Cisplatino/efeitos adversos , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/patologia , Quimioterapia de Indução , Fluoruracila/uso terapêutico
18.
Materials (Basel) ; 15(11)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35683167

RESUMO

A high sintering temperature is usually required to acquire excellent performance in the ceramic industry, but it results in high fuel consumption and high pollution. To reduce the sintering temperature and to toughen the porcelain, a self-produced sintering additive of citric acid activated kaolinite was added to the raw material; X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and thermal gravity analysis and differential scanning calorimetry (TG-DSC) were used to characterize the samples, and the toughening mechanism was discussed. The citric acid activated kaolinite obtained high activity and a large specific surface area. After introducing the activated kaolinite, the bending strength of porcelain at 1270 °C increased from 100.08 MPa to 124.04 Mpa, which was 11.45% higher than that of porcelain without activated kaolinite at 1350 °C. The results of XRD revealed that the content of mullite increased and the quartz decreased at 1270 °C, and the well-distributed needle-like mullite was observed in the images of SEM with the addition of citric acid activated kaolinite. The TG-DSC results indicated adding activated kaolinite to porcelain raw materials reduced the formation of mullite to 994.6 °C. The formation of mullite in a lower temperature served as mullite seeds in a green body during firing, and it enhanced the growth of mullite. These contributed to the appropriate phase composition and the excellent microstructure of porcelain. Thus, the distinguished mechanical performance of porcelain was obtained. Moreover, the sintering additive had no adverse effect on the porcelain body as citric acid-activated kaolinite was one of the main components of the porcelain raw material.

19.
Nanomaterials (Basel) ; 12(12)2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35745445

RESUMO

In this study, a series of well-crystallized Yb3+/Er3+/Tm3+-tridoped Y2O3-ZnO ceramic nano-phosphors were prepared using sol-gel synthesis, and the phosphor structures were studied using X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The phosphors were well crystallized and exhibited a sharp-edged angular crystal structure and mesoporous structure consisting of 270 nm nano-particles. All phosphors generated blue, green, and red emission bands attributed to Tm: 1G4→3H6, Er: 2H11/2 (4S3/2)→4I15/2, and Er: 4F9/2→4I15/2 radiative transitions, respectively. Increasing in luminescent centers, weakening of lattice symmetry, and releasing of dormant rare earth ions can enhance all emissions. Er3+ can obtain energy from Tm3+ to enhance green and red emission. These colors can be tuned by optimizing the doping concentrations of the Er3+ ion. The color coordinates were adjusted by tuning both the Er3+ concentration and excitation laser pump power to shift the color coordinates and correlated color temperature. The findings of this study will broaden the potential practical applications of phosphors.

20.
Transl Lung Cancer Res ; 10(4): 1711-1719, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34012787

RESUMO

BACKGROUND: Some pulmonary nodules are not suitable for computed tomography-guided percutaneous localization. This study aimed to investigate the feasibility and safety of real-time localization for these non-palpable pulmonary nodules using watershed analysis of the target pulmonary artery during thoracoscopic wedge resection. METHODS: Watershed analysis is a novel technique that can be used to create a specific area on the lung surface for nodule localization. This analysis is performed by temporarily blocking the target pulmonary artery and using indocyanine green fluorescence during surgery. In our study, the surgery was simulated and evaluated preoperatively using a high-precision three-dimensional reconstruction model obtained by multidetector spiral computed tomography. The lung was observed using an infrared thoracoscopy system after an intravenous injection of indocyanine green (2.5 mg/mL), and the white-to-blue transitional zone was marked using electrocautery, after which a wedge resection was performed. RESULTS: A total of 25 out of 26 patients underwent successful wedge resection. The mean tumor size and depth based on computed tomography scans were 13.2±6.4 and 12.2±7.8 mm, respectively. The mean operation duration was 142.6±52.8 min. The mean bleeding volume during surgery was 12.9±9.7 mL. The mean drainage tube indwelling time was 35.6±20.0 h, and the median length of postoperative stay was 3 days (range, 2-6 days). CONCLUSIONS: Our experience showed that the watershed analysis of the target pulmonary artery for nodule localization was safe and feasible. It may become an effective and attractive alternative method for localizing non-palpable pulmonary nodules in selected patients undergoing thoracoscopic wedge resection.

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