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1.
Cancer Res ; 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38471084

RESUMO

Dysregulation of cholesterol homeostasis is implicated in the development and progression of hepatocellular carcinoma (HCC) that is characterized by intrahepatic and early extrahepatic metastasis. A better understanding of the underlying mechanisms regulating cholesterol metabolism in HCC could help identify strategies to circumvent the aggressive phenotype. Here, we found that high expression of intracellular SPARC was significantly associated with elevated cholesterol levels and an enhanced invasive phenotype in HCC. SPARC potentiated cholesterol accumulation in HCC cells during tumor progression by stabilizing the ApoE protein. Mechanistically, SPARC competitively bound to ApoE, impairing its interaction with the E3 ligase tripartite motif containing 21 (TRIM21) and preventing its ubiquitylation and subsequent degradation. ApoE accumulation led to cholesterol enrichment in HCC cells, stimulating PI3K-AKT signaling and inducing epithelial-mesenchymal transition (EMT). Importantly, sorafenib-resistant HCC cells were characterized by increased expression of intracellular SPARC, elevated cholesterol levels, and enhanced invasive capacity. Inhibiting SPARC expression or reducing cholesterol levels enhanced the sensitivity of HCC cells to sorafenib treatment. Together, these findings unveil interplay between SPARC and cholesterol homeostasis. Targeting SPARC-triggered cholesterol-dependent oncogenic signaling is a potential therapeutic strategy for advanced HCC.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 311: 123995, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38341934

RESUMO

In this study, a simple, rapid and sensitive method combining surface-enhanced Raman spectroscopy and Schiff base reaction was developed for the detection of tryptophan. This method does not require product separation to obtain a significant Raman signal of the derivatized product, and the derivatization reaction can be controlled by experimental parameters such as reaction temperature, time, concentration of derivatization reagent and concentration of sodium nitrite. The characteristic peak of the derivative of tryptophan (1620 cm-1) was selected for quantitative analysis, and the intensity of the characteristic Raman spectrum peak showed a linear relationship with the concentration of tryptophan (10-8-10-4 mol/L) in the range of with a correlation coefficient R2 of 0.9922. This assay combines surface-enhanced Raman spectroscopy and Schiff base reaction, which is characterized by high sensitivity and easy operation, and has good application prospects in the detection of tryptophan in food.


Assuntos
Nanopartículas Metálicas , Triptofano , Triptofano/química , Prata/química , Análise Espectral Raman/métodos , Bases de Schiff , Nanopartículas Metálicas/química
3.
Sheng Wu Gong Cheng Xue Bao ; 40(1): 35-52, 2024 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-38258630

RESUMO

WRKYs is a unique family of transcription factors (TFs) in plants, and belongs to the typical multifunctional regulator. It is involved in the regulation of multiple signaling pathways. This type of transcription factor is characterized to contain about 60 highly conservative amino acids as the WRKY domain, and usually also has the Cys2His2 or Cys2His-Cys zinc finger structure. WRKYs can directly bind to the W-box sequence ((T)(T) TGAC (C/T)) in the promoter region of the downstream target gene, and activate or inhibit the transcription of the target genes by interacting with the target protein. They may up-regulate the expression of stress-related genes through integrating signal pathways mediated by abscisic acid (ABA) and reactive oxygen species (ROS), thus playing a vital role in regulating plant response to abiotic stresses. This review summarizes the advances in research on the structure and classification, regulatory approach of WRKYs, and the molecular mechanisms of WRKYs involved in response to drought and salt stresses, and prospects future research directions, with the aim to provide a theoretical support for the genetic improvement of crop in response to abiotic stresses.


Assuntos
Ácido Abscísico , Fatores de Transcrição , Fatores de Transcrição/genética , Aminoácidos , Secas , Estresse Fisiológico/genética
4.
RSC Adv ; 14(4): 2678-2686, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38229715

RESUMO

Coal and coal ash (slag and fly ash) have emerged as important potential sources for rare earth elements (REY). The distribution and enrichment of REY during coal combustion from coal-fired power plants are of great significance for the recovery of REY. In this study, the concentration of REY in coal and coal ash from four coal-fired power plants in China was determined using microwave digestion-inductively coupled plasma mass spectrometry. The distribution and enrichment characteristics of REY in coal and coal ash were studied. The coal ash contains 310-683 µg g-1 of REY, and the proportion of critical REY was greater than 30%, which is higher than the extraction concentration (300 µg g-1) recommended by the United States Department of Energy, indicating significant REY recovery potential. The concentration of REY in coal was positively correlated with ash yield, which could be explained by the fact that REY are mainly distributed in minerals. Coal and coal ash show similar REY distribution patterns, indicating that REY were not fractionated during the coal combustion. In addition, the enrichment coefficient of REY in fly ash was greater than that in slag, which revealed that REY were mainly enriched in fly ash. Therefore, the REY in fly ash has more recycling potential.

5.
Obes Surg ; 34(3): 1049-1051, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38285302

RESUMO

Single-port or single-incision laparoscopic surgery (SILS) is esteemed for its efficacy in achieving superior postoperative cosmetic outcomes compared to the conventional laparoscopic approach (Behnia-Willison et al. in Aust N Z J Obstet Gynaecol 52:366-370, 2012; Rogula et al. in Obes Surg 24:1102-1108, 2014; Pitot et al. in Surg Endosc 28:3007-3011, 2014). The introduction of SILS for bariatric procedures can be attributed to the pioneering work of Saber in 2008, who initially applied this technique to laparoscopic sleeve gastrectomy (SG), followed by its utilization in laparoscopic adjustable gastric banding (AGB) (Saber et al. in Obes Surg 18:1338-1342, 2008;Nguyen et al. in Obes Surg 18:1628-1631, 2008). The inaugural application of SILS in Roux-en-Y gastric bypass (RYGB) was documented in 2009, employing a plastic reconstruction methodology. Acknowledging the intricate nature of complex bariatric interventions, we previously detailed a modified SILS approach termed the transumbilical two-site (TUTS) technique for RYGB, which was established as a standard procedure in 2010 (Lee et al. in Surg Obes Relat Dis. 8:208-13, 2012). At that juncture, a solitary article surfaced in 2010 elucidating the dimensions of the small gastric pouch as a mere 8-9 cm, falling short of contemporary surgical requisites for optimal outcomes in one anastomosis gastric bypass (OAGB) (Tacchino et al. in Obes Surg 20:1154-1160, 2010). Notably, the TUTS technique, which was successfully implemented for RYGB, had hitherto not been extended to OAGB due to the complexities associated with creating a slender gastric tube spanning 25 cm. In a pioneering development this year, we have devised a novel strategy to surmount this challenge. The present study is designed to expound upon the transumbilical stapling technique tailored to the unique demands of OAGB.


Assuntos
Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Humanos , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Estômago/cirurgia , Gastrectomia/métodos , Laparoscopia/métodos , Estudos Retrospectivos
6.
Asian J Endosc Surg ; 17(1): e13258, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37952933

RESUMO

BACKGROUND: One anastomosis gastric bypass (OAGB) is a new recognized metabolic surgery, but the problem that we cannot screen the excluded stomach is a troubling issue in China. The emergence of sleeve gastrectomy plus one anastomosis bipartition (SG + OAB) makes us see a hope to solve this problem. OBJECTIVES: By comparing the efficacy of the two surgical methods, to evaluate whether SG + OAB surgery can solve the dilemma faced by OAGB that the excluded stomach cannot be screened. METHODS: A retrospective study to compare the patients who underwent OAGB and SG + OAB was conducted. The main outcome measures were (1) operation risk, (2) weight loss, and (3) diabetes remission at 6 months. RESULTS: This study was conducted in the bariatric/metabolic surgical center. From November 2021 to February 2022, a total of 30 patients with obesity who received SG + OAB surgery were recruited. Another matched 60 patients undergoing OAGB were recruited as control group. There was no difference in preoperative age (32.15 ± 9.02 vs. 34.47 ± 7.22; p = .224), female ratio (83% vs. 85%; p = .837), and BMI (36.18 ± 5.30 vs. 34.68 ± 5.58; p = .217) between the two groups. OAGB had a shorter mean operation time (121.67 ± 20.41 vs. 143.50 ± 25.07 min; p < .001) and a lower intraoperative blood loss (21.92 ± 12.35 vs. 32.43 ± 22.01 mL; p = .005), but a longer postoperative flatus passage (2.13 ± 0.43 vs. 1.87 ± 0.43 days; p = .007) compared with the SG + OAB group. Two patients (6.7%) developed major surgical complication in SG + OAB group but no major complication developed in OAGB group. At 6 months after surgery, SG + OAB had a higher %total weight loss than OAGB (31.05 ± 3.12 vs. 28.14 ± 5.43%; p = .015), but diabetes remission rate was similarly high in both groups. CONCLUSIONS: SG + OAB operation had a non-inferior or even better weight loss than OAGB, with a similar glycemic control efficacy. However, the high complication rate of SG + OAB is the major drawback that needs attention.


Assuntos
Diabetes Mellitus , Derivação Gástrica , Obesidade Mórbida , Humanos , Feminino , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Obesidade Mórbida/complicações , Projetos Piloto , Estudos Retrospectivos , Gastrectomia/métodos , Redução de Peso , Diabetes Mellitus/cirurgia , Resultado do Tratamento
8.
Int J Ophthalmol ; 16(6): 855-862, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37332540

RESUMO

AIM: To determine the effects of protocatechuic acid (PCA) on streptozocin-induced diabetic retinopathy (DR) in rats. METHODS: Wistar rats were given a 50 mg/kg intraperitoneal injection of streptozocin to induce diabetes. Animals were assigned randomly one of four groups (8 rats per group): control, diabetic, diabetic plus PCA (25 mg/kg·d), and diabetic plus PCA (50 mg/kg·d). After inducing diabetes, treatments were started one week later and continued for eight weeks. After the experiment, the rats were sacrificed, and their retinas were taken for biochemical and molecular analysis. RESULTS: PCA administration diminished the blood glucose and glycated haemoglobin levels relative to the diabetic group. In diabetic rats, PCA lowered elevated levels of advanced glycosylated end products (AGEs) and receptor for AGEs (RAGE). In the retina of diabetic rats, PCA effectively decreased inflammatory cytokine, nuclear factor-κB, tumour necrosis factor-α, interleukin-1ß, and vascular endothelial growth factor, and increased antioxidant markers glutathione, superoxide dismutase, and catalase. CONCLUSION: The protective benefits of PCA against DR may be attributable to its suppression of the AGEs and RAGE and its antioxidant and anti-inflammatory properties.

9.
Molecules ; 28(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37175147

RESUMO

H1.6Mn1.6O4 lithium-ion screen adsorbents were synthesized by soft chemical synthesis and solid phase calcination and then applied to the recovery of metal Li and Co from waste cathode materials of a lithium cobalt oxide-based battery. The leaching experiments of cobalt and lithium from cathode materials by a citrate hydrogen peroxide system and tartaric acid system were investigated. The experimental results showed that under the citrate hydrogen peroxide system, when the temperature was 90 °C, the rotation speed was 600 r·min-1 and the solid-liquid ratio was 10 g·1 L-1, the leaching rate of Co and Li could reach 86.21% and 96.9%, respectively. Under the tartaric acid system, the leaching rates of Co and Li were 90.34% and 92.47%, respectively, under the previous operating conditions. The adsorption results of the lithium-ion screen showed that the adsorbents were highly selective for Li+, and the maximum adsorption capacities were 38.05 mg·g-1. In the process of lithium removal, the dissolution rate of lithium was about 91%, and the results of multiple cycles showed that the stability of the adsorbent was high. The recovery results showed that the purity of LiCl, Li2CO3 and CoCl2 crystals could reach 93%, 99.59% and 87.9%, respectively. LiCoO2 was regenerated by the sol-gel method. XRD results showed that the regenerated LiCoO2 had the advantages of higher crystallinity and less impurity.

10.
Artigo em Inglês | MEDLINE | ID: mdl-35926705

RESUMO

As the representative genetic and economic trait of ornamental fish, skin color has a strong impact on speciation and adaptation. However, the genetic basis of skin color pigmentation, differentiation and change is still not understood. The Midas cichlid fish with three typical body color transition stages of "black-gray­gold" is an ideal model system for investigating the formation and change of fish body color. In this study, to investigate the regulatory role of the pair box 3 (pax3) gene in the early body color fading process of Midas cichlids, the complete cDNA sequence (3513 bp) of pax3 was successfully isolated from Midas cichlids (Amphilophus Citrinellus), and found to encode polypeptides of 491 amino acids. Expression patterns of the pax3 gene in tissues of Midas cichlids during different periods, including embryonic development and body color fading stages were detected by quantitative real-time PCR. The qRT-PCR analysis showed that pax3 was expressed in all tissues of adult fish, with a higher expression level in muscle and skin. The highest expression level in muscle tissue was significantly higher than that in other tissues (P < 0.05). During embryonic development, the expression tendency of pax3 was first increased and then decreased. In the three typical stages of early skin color fading from black to gold, pax3 expression in skin, caudal fin and scales all showed a downward trend. The expression level in the black stage was significantly higher than that in other stages (P < 0.05). Positive signal of pax3 protein was detected in the three typical skin color conversion stages, and the highest positive signal intensity was detected in the black stage, which was consistent with qRT-PCR results. After pax3 RNA interference, pax3 and the downstream genes mitf and tyr all decreased, while dct mRNA expression increased in the skin of fish. Western blotting also showed a decrease in pax3 protein concentration. Those results suggest that pax3 plays an important role in skin color formation, distribution and change in Midas cichlids through the melanogenesis pathway.

11.
Artigo em Inglês | MEDLINE | ID: mdl-36429557

RESUMO

The quality of teacher-student relationships has been shown to relate to adolescents' prosocial behavior, but the motivational mechanisms underlying this association remained unclear. Based on relationships motivation theory (RMT), we examined whether the associations between teacher-student relationships (closeness and conflict) and prosocial behavior are bidirectional, and the mediating role of basic psychological need satisfaction (autonomy, competence, and relatedness need satisfaction) in these links. Data were collected from a sample of 438 secondary school students who completed a survey at two-time points over eight months. The cross-lagged autoregressive model revealed that the relation between close teacher-student relationship and prosocial behavior was bidirectional over time. Moreover, relatedness need satisfaction mediated the positive effect of close teacher-student relationship and the negative effect of teacher-student relationship conflict on adolescents' prosocial behavior. This study highlights the importance of close teacher-student relationship and relatedness need satisfaction to foster adolescents' prosocial behavior.


Assuntos
Pessoal de Educação , Satisfação Pessoal , Humanos , Adolescente , Altruísmo , Relações Interpessoais , Estudantes/psicologia
12.
Sheng Wu Gong Cheng Xue Bao ; 38(10): 3773-3789, 2022 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-36305409

RESUMO

High-affinity K+ transporter (HAK) is one of the most important K+ transporter families in plants and plays an important role in plant K+ uptake and transport. To explore the biological functions and gene expression patterns of the HAK gene family members in sugar beet (Beta vulgaris), physicochemical properties, the gene structure, chromosomal location, phylogenetic evolution, conserved motifs, three-dimensional structure, interaction network, cis-acting elements of promoter of BvHAKs were predicted by bioinformatic analysis, and their expression levels in different tissues of sugar beet under salt stress were analyzed by qRT-PCR. A total of 10 BvHAK genes were identified in the sugar beet genome. They contained 8-10 exons and 7-9 introns. The average number of amino acids was 778.30, the average molecular weight was 88.31 kDa, and the isoelectric point was 5.38-9.41. The BvHAK proteins contained 11-14 transmembrane regions. BvHAK4, -5, -7 and -13 were localized on plasma membrane, while others were localized on tonoplast. Phylogenetic analysis showed that HAK in higher plants can be divided into five clusters, namely cluster Ⅰ, Ⅱ, Ⅲ, Ⅳ, and Ⅴ, among which the members of cluster Ⅱ can be divided into three subclusters, including Ⅱa, Ⅱb, and Ⅱc. The BvHAK gene family members were distributed in cluster Ⅰ-Ⅳ with 1, 6, 1, and 2 members, respectively. The promoter of BvHAK gene family mainly contained stress responsive elements, hormone responsive elements, and growth and development responsive elements. The expression pattern of the BvHAK genes were further analyzed in different tissues of sugar beet upon salt treatment, and found that 50 and 100 mmol/L NaCl significantly induced the expression of the BvHAK genes in both shoots and roots. High salt (150 mmol/L) treatment clearly down-regulated their expression levels in shoots, but not in roots. These results suggested that the BvHAK gene family plays important roles in the response of sugar beet to salt stress.


Assuntos
Beta vulgaris , Beta vulgaris/genética , Regulação da Expressão Gênica de Plantas , Filogenia , Raízes de Plantas , Açúcares/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
13.
Child Abuse Negl ; 132: 105806, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35917752

RESUMO

BACKGROUND: Parental neglect has been shown to be associated with adolescents' peer alienation. However, few previous studies have considered parental phubbing as a new form of social neglect during parent-child interactions related to adolescents' peer alienation, and much less is known about the mechanisms underlying this relationship. OBJECTIVE: The present study explored the relationship between father phubbing (Fphubbing) and mother phubbing (Mphubbing) and adolescents' peer alienation. Moreover, it examined whether adolescents' perceived paternal and maternal rejection mediate these associations. PARTICIPANTS AND SETTING: A sample of 1140 students (Mage = 12.18 years, SD = 0.90) completed the measures of parental phubbing, parental rejection, and peer alienation. METHODS: Structural equation modeling was used to assess the direct effects of Fphubbing and Mphubbing on adolescents' peer alienation and their indirect effects through adolescents' perceived paternal and maternal rejection as mediators. RESULTS: The results indicated that Fphubbing and Mphubbing were positively related to adolescents' peer alienation. Perceived maternal rejection mediated the relationship between Mphubbing and adolescents' peer alienation. The relationship between Mphubbing and maternal rejection was stronger for adolescent girls. CONCLUSIONS: Our study offers a preliminary understanding of how parental phubbing associates with adolescents' peer alienation through the mediating role of adolescents' perceived parental rejection, which has certain theoretical and practical implications for comprehending adolescents' peer alienation in the mobile age.


Assuntos
Relações Pais-Filho , Pais , Adolescente , Criança , Pai , Feminino , Humanos , Masculino , Mães , Grupo Associado
14.
Obes Surg ; 32(9): 2945-2951, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35790674

RESUMO

BACKGROUND: One anastomosis gastric bypass (OAGB) is gradually accepted worldwide but still new in China. MATERIALS AND METHODS: Retrospective review of the patients who received OAGB in a new bariatric/metabolic surgical center in China and compared the data with a center of excellence in Taiwan. All in-patient and outpatient follow-up data were analyzed. The main outcome measures were (1) operation risk (2) weight loss (3) diabetes remission. RESULTS: Between August 2019 and October 2021, 100 consecutive patients who received OAGB in situ in China and 225 patients who received OAGB with the same technique were recruited from Taiwan. Taiwan patients were older (39.2 ± 10.6 vs. 33.3 ± 8.8 years old, p < 0.001), and to have more diabetes (32.4% vs. 20.0%, p = 0.022) comparing to the patients of China. Operation time was significantly longer for Taiwan patients (172.4 ± 36.9 vs. 128.5 ± 29.8, p < 0.001). Taiwan patients lost more blood during the operation (35.5 ± 25.2 vs. 22.4 ± 15.6, p < 0.001) but patients in China need more time to postoperative flatus passage (1.3 ± 0.5 vs. 2.0 ± 0.5, p < 0.001). There was no major surgical complication in this study, minor complication rates were similar low for both groups (1.0% vs. 1.8%, p = 0.891). At 1 year after surgery, %TWL and %EWL of both centers were similar (33.9 ± 7.43% vs. 32.6 ± 11.2%, p = 0.91; 81.9 vs. 19.8 vs. 85.4 ± 13.2, p = 0.798). T2DM remission (HbA1c < 6.5%) was 100% for patients of China and 95.9% for patients of Taiwan (p = 0.836). CONCLUSIONS: OAGB in situ is a safe and effective bariatric/metabolic surgery. With proper training and proctorship, these results are reproduceable in a new bariatric/metabolic surgical center in China.


Assuntos
Cirurgia Bariátrica , Derivação Gástrica , Obesidade Mórbida , Adulto , China/epidemiologia , Derivação Gástrica/métodos , Humanos , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Redução de Peso , Adulto Jovem
15.
Sens Actuators B Chem ; 369: 132306, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35813462

RESUMO

The continuing global spread of Coronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, has led to an unprecedented global health crisis. Effective and affordable methods are needed to diagnose SARS-CoV-2 infection. In this work, a ratiometric fluorescence probe, Si-Mn:ZnSe nanoparticles, was constructed through the electrostatic interaction between Si dots and Mn:ZnSe QDs, and the fluorescence of Mn:ZnSe QDs has a specifical response to H2O2. An immunocomplex was formed by the recognition of capture antibody/spike (S) protein/spike neutralizing antibody/biotinylated second antibody/streptavidin/biotinylated catalase (CAT). In the presence of S protein, CAT effectively catalyzed the decomposition of H2O2 in the system, and the fluorescence of Mn:ZnSe QDs was not specifically quenched. Based on this principle, a ratiometric immunoassay of SARS-CoV-2 S protein was established. The sensitivity of the proposed ELISA method was comparable to that of the commercial kit. In addition, this method can effectively distinguish the pseudo-SARS-CoV-2 virus and other pseudovirus. Therefore, this method provided a reliable and potential direction for diagnosing SARS-CoV-2 infection.

16.
Front Chem ; 10: 912489, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646813

RESUMO

With the environmental deterioration and the rise in demand for sustainability, the lack of freshwater resources has emerged as a global concern. To address this issue, the desalination of water using solar evaporation is centered on as a promising approach. In this study, we designed a light and photothermal liquefied-chitin-based polyurethane foam to achieve efficient water evaporation benefiting from their powerful solar spectral absorption, low thermal conductivity, quick transportation of water, hierarchically porous structures, and anti-biofouling natures. Moreover, because of the introduction of nano-silver, the newly developed foam exhibits considerable antibacterial ability and improved photothermal performance. Notably, the low thermal conductivity of the foam can reduce the loss of absorbed solar heat, whereas its large porous structure provides a smooth water transport channel. More importantly, with the assistance of heat, polyacrylamide hydrogels adhering along with the pores rapidly absorb and desorb water molecules, promoting the evaporation of water and improving solar energy conversion efficiency. Ultimately, under irradiation by one sunlight, the proposed material demonstrated a water evaporation rate and solar photothermal conversion efficiency of 2.44 kg m-2 h-1 and 153.2%, respectively.

18.
Anal Methods ; 14(23): 2266-2276, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35621162

RESUMO

In the present study, a novel simple and sensitive method was developed for the determination of pectin based on the decarboxylation derivatization reaction and surface-enhanced Raman scattering (SERS) without complicated separation steps. The derivatization reaction can be controlled by the experimental parameters such as reaction time, temperature and the amount of hydrochloric acid. Additionally, the method was used to accurately and reliably detect pectin added in honey or apple, which can be detected at levels as low as 0.5 or 0.01 ppm, respectively. Based on the conventional decarboxylation reaction, a simple and sensitive SERS method was proposed for the detection of pectin, which shows potential for practical application.


Assuntos
Mel , Malus , Descarboxilação , Malus/química , Pectinas , Análise Espectral Raman
19.
Anal Chem ; 94(18): 6665-6671, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35466670

RESUMO

Intracellular pH is an important regulator of cell function, and its subtle changes may greatly affect cell activities and cause diseases. Reliable imaging of intracellular pH remains a huge challenge. Dual-emitting Mn2+-doped quantum dots (QDs) can be directly used as a ratiometric fluorescent probe without further modification, but they displayed low performance in terms of photoluminescence, stability, and intensity ratio regulation. Here, we report intrinsic dual-emitting CdZnSe/Mn:ZnS QDs with high photoluminescence efficiency, good stability, and biocompatibility. The emission intensity ratio was selectively regulated by Mn2+ doping. Because of aggregation-induced quenching of QDs, the exciton emission of CdZnSe/Mn:ZnS QDs (471 nm) was sensitive to pH, while the Mn2+-doped emission (606 nm) was passive to pH, which was probably due to little self-quenching in Mn2+-doped emission caused by weak Mn-Mn coupling interaction. Dual-emitting CdZnSe/Mn:ZnS QDs exhibited excellent pH-responsiveness in the range of pH 4.0 to 12.0 and were used for pH imaging in live HeLa cells. When the pH value of HeLa cells changed from 5.0 to 9.0, the emission changed from red to blue. Furthermore, these dual-emitting CdZnSe/Mn:ZnS QDs can provide a versatile platform for biosensors and biological imaging.


Assuntos
Pontos Quânticos , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Manganês , Pontos Quânticos/toxicidade , Sulfetos , Compostos de Zinco
20.
Environ Sci Pollut Res Int ; 29(29): 44709-44722, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35133594

RESUMO

Coal ash has emerged as an important alternative source for rare earth elements (REEs). The enrichment and occurrence form of REEs among coal combustion products are of great significance for both technical design and economic evaluation of recovering REEs from the coal ash. Here, the enrichment and occurrence form of REEs in the ash were investigated. Compared with ashes from muffle furnace, coal fly ash (CFA) from power plants involved higher enrichment ratio of REEs, which was explained by the fractionation of coal ashes to concentrate REEs in finer CFA, higher combustion temperature to vaporize more volatile elements, and longer residence time of fly ash to absorb REEs in the gas. In addition, CFA samples were analyzed by sequence chemical extraction procedure (SCEP) and scanning electron microscope with an energy dispersive spectrometer (SEM-EDX), which revealed the important role of aluminum in the occurrence form of REEs compared with Si in aluminosilicates of CFA. This conclusion was further confirmed by thermodynamic equilibrium calculation, which also agreed qualitatively with the observation that REEs mainly existed in the solid phase. Both experimental and computational results of this work provided insights to understand the distribution of REEs in CFA and optimize their extraction processes.


Assuntos
Carvão Mineral , Metais Terras Raras , Fracionamento Químico , Carvão Mineral/análise , Cinza de Carvão/análise , Centrais Elétricas
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