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1.
Chem Rev ; 123(5): 1925-2015, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36724185

RESUMO

Modern technology has enabled the isolation of nanocellulose from plant-based fibers, and the current trend focuses on utilizing nanocellulose in a broad range of sustainable materials applications. Water is generally seen as a detrimental component when in contact with nanocellulose-based materials, just like it is harmful for traditional cellulosic materials such as paper or cardboard. However, water is an integral component in plants, and many applications of nanocellulose already accept the presence of water or make use of it. This review gives a comprehensive account of nanocellulose-water interactions and their repercussions in all key areas of contemporary research: fundamental physical chemistry, chemical modification of nanocellulose, materials applications, and analytical methods to map the water interactions and the effect of water on a nanocellulose matrix.

2.
Kidney Int ; 105(3): 442-444, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38388145

RESUMO

This commentary provides an analysis of the study by Fu et al. in Kidney International, which employs 3 administrative databases to investigate the hyperkalemia protective effects of sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors. It emphasizes the methodological approach, notably the use of a fixed-effect model to aggregate pairwise comparisons from 3 data sets. In addition, we explored the broader cardiorenal and potential nonrenal benefits of these drug classes, underscoring the imperative for continued research in this domain.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Hipoglicemiantes/efeitos adversos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Agonistas do Receptor do Peptídeo 1 Semelhante ao Glucagon , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Receptor do Peptídeo Semelhante ao Glucagon 1
3.
Bioorg Chem ; 148: 107482, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795582

RESUMO

Toad venom, a traditional Chinese medicine, exhibits remarkable medicinal properties of significant therapeutic value. The peptides present within toad venom possess a wide range of biological functions, yet the neuropeptide B (NPB) and it modification requires further exploration to comprehensively understand its mechanisms of action and potential applications. In this study, a fusion peptide, ANTP-BgNPB, was designed to possess better analgesic properties through the transdermal modification of BgNPB. After optimizing the conditions, the expression of ANTP-BgNPB was successfully induced. The molecular dynamics simulations suggested that the modified protein exhibited improved stability and receptor binding affinity compared to its unmodified form. The analysis of the active site of ANTP-BgNPB and the verification of mutants revealed that GLN3, SER38, and ARG42 were crucial for the protein's recognition and binding with G protein-coupled receptor 7 (GPR7). Moreover, experiments conducted on mice using the hot plate and acetic acid twist body models demonstrated that ANTP-BgNPB was effective in transdermal analgesia. These findings represent significant progress in the development of transdermal delivery medications and could have a significant impact on pain management.


Assuntos
Analgésicos , Desenho de Fármacos , Animais , Analgésicos/química , Analgésicos/farmacologia , Camundongos , Peptídeos/química , Peptídeos/farmacologia , Administração Cutânea , Masculino , Relação Estrutura-Atividade , Simulação de Dinâmica Molecular , Estrutura Molecular , Relação Dose-Resposta a Droga , Dor/tratamento farmacológico , Humanos
4.
Cryobiology ; 114: 104811, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38061638

RESUMO

A directed vat set (DVS) starter was proposed to improve the drawbacks of liquid starters in fermented production and enhance the survival rates of B. animalis subsp. lactis BZ11, S. thermophilus Q-1, and Lactiplantibacillus plantarum LB12. The protective agent formula was optimized using the response surface method (RSM), with the survival rate as the benchmark. The best combination of cryoprotectants was determined to be BZ11: 10 % skimmed milk powder, 3 % sodium glutamate, and 15 % trehalose; LB12: 10 % skim milk powder, 5 % glutamate sodium, and 10 % trehalose; Q-1: 10 % skimmed milk powder, 3 % sodium glutamate, and 10 % trehalose. The survival rate of BZ11 significantly increased to 92.87 ± 1.25 %. The DVS fermented milk did not differ significantly from the control group regarding cholesterol removal, live cell counts and pH (p > 0.05). All DVS can be stored for at least 2500 d at -20 °C-this DVS starter for fermented milk benefits from its large-scale and automated commercial production.


Assuntos
Leite , Glutamato de Sódio , Animais , Fermentação , Taxa de Sobrevida , Trealose/farmacologia , Pós , Criopreservação/métodos , Crioprotetores/farmacologia
5.
Skin Res Technol ; 30(1): e13540, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38186043

RESUMO

BACKGROUND: Sensitive skin is a common condition affecting a significant proportion of the population, and there is a growing demand for effective and safe management. AIM: To evaluate the efficacy and safety of a cream containing panthenol, prebiotics, and probiotic lysate as an optimal care for facial sensitive skin. METHODS: A total of 110 participants (64 in group A and 46 in group B) with facial sensitive skin applied the cream twice daily for 28 days. Group A evaluated their sensitive skin, product efficacy, and product use experience at D0 (15 min), D1, D14, and D28. In group B, skin barrier function-related indicators were measured at baseline and on D1, D7, D14, and D28. Dermatologists evaluated tolerance for all participants. RESULTS: After 28 days of use, in group A, 100% of participants reported mildness and comfort with product use. Participants demonstrated significant improvements in skin barrier function-related indicators, including increased stratum corneum moisture content, reduced erythema index, elevated sebum content, decreased trans-epidermal water loss, and diminished skin redness parameter a* value (all p < 0.05). Dermatologist evaluations revealed excellent tolerance among all participants. CONCLUSION: The panthenol-enriched cream with prebiotics and probiotic lysate exhibited substantial clinical efficacy in ameliorating facial sensitive skin conditions, coupled with a high safety profile.


Assuntos
Dermatoses Faciais , Probióticos , Humanos , Prebióticos/efeitos adversos , Probióticos/efeitos adversos , Ácido Pantotênico , Emolientes
6.
Crit Care Med ; 51(12): 1777-1789, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37470680

RESUMO

OBJECTIVES: This study aimed to conduct a comprehensive and updated systematic review with network meta-analysis (NMA) to assess the outcome benefits of various blood purification modalities for adult patients with severe infection or sepsis. DATA SOURCES: We conducted a search of PubMed, MEDLINE, clinical trial registries, Cochrane Library, and Embase databases with no language restrictions. STUDY SELECTION: Only randomized controlled trials (RCTs) were selected. DATA EXTRACTION: The primary outcome was overall mortality. The secondary outcomes were the length of mechanical ventilation (MV) days and ICU stay, incidence of acute kidney injury (AKI), and kidney replacement therapy requirement. DATA SYNTHESIS: We included a total of 60 RCTs with 4,595 participants, comparing 16 blood purification modalities with 17 interventions. Polymyxin-B hemoperfusion (relative risk [RR]: 0.70; 95% CI, 0.57-0.86) and plasma exchange (RR: 0.61; 95% CI, 0.42-0.91) were associated with low mortality (very low and low certainty of evidence, respectively). Because of the presence of high clinical heterogeneity and intransitivity, the potential benefit of polymyxin-B hemoperfusion remained inconclusive. The analysis of secondary outcomes was limited by the scarcity of available studies. HA330 with high-volume continuous venovenous hemofiltration (CVVH), HA330, and standard-volume CVVH were associated with shorter ICU stay. HA330 with high-volume CVVH, HA330, and standard-volume CVVH were beneficial in reducing MV days. None of the interventions showed a significant reduction in the incidence of AKI or the need for kidney replacement therapy. CONCLUSIONS: Our NMA suggests that plasma exchange and polymyxin-B hemoperfusion may provide potential benefits for adult patients with severe infection or sepsis/septic shock when compared with standard care alone, but most comparisons were based on low or very low certainty evidence. The therapeutic effect of polymyxin-B hemoperfusion remains uncertain. Further RCTs are required to identify the specific patient population that may benefit from extracorporeal blood purification.


Assuntos
Injúria Renal Aguda , Sepse , Choque Séptico , Adulto , Humanos , Metanálise em Rede , Ensaios Clínicos Controlados Aleatórios como Assunto , Polimixina B/uso terapêutico , Injúria Renal Aguda/tratamento farmacológico
7.
Plant Cell Environ ; 46(8): 2401-2418, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37190917

RESUMO

High temperatures (HTs) seriously affect the yield and quality of tea. Catechins, derived from the flavonoid pathway, are characteristic compounds that contribute to the flavour of tea leaves. In this study, we first showed that the flavonoid content of tea leaves was significantly reduced under HT conditions via metabolic profiles; and then demonstrated that two transcription factors, CsHSFA1b and CsHSFA2 were activated by HT and negatively regulate flavonoid biosynthesis during HT treatment. Jasmonate (JA), a defensive hormone, plays a key role in plant adaption to environmental stress. However, little has been reported on its involvement in HT response in tea. Herein, we demonstrated that CsHSFA1b and CsHSFA2 activate CsJAZ6 expression through directly binding to heat shock elements in its promoter, and thereby repress the JA pathway. Most secondary metabolites are regulated by JA, including catechin in tea. Our study reported that CsJAZ6 directly interacts with CsEGL3 and CsTTG1 and thereby reduces catechin accumulation. From this, we proposed a CsHSFA-CsJAZ6-mediated HT regulation model of catechin biosynthesis. We also determined that negative regulation of the JA pathway by CsHSFAs and its homologues is conserved in Arabidopsis. These findings broaden the applicability of the regulation of JAZ by HSF transcription factors and further suggest the JA pathway as a valuable candidate for HT-resistant breeding and cultivation.


Assuntos
Camellia sinensis , Catequina , Camellia sinensis/metabolismo , Catequina/metabolismo , Temperatura , Proteínas de Plantas/metabolismo , Flavonoides/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Chá/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo
8.
Biomacromolecules ; 24(1): 367-376, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36479984

RESUMO

Here, we describe the all-aqueous bicontinuous emulsions with cholesteric liquid crystal domains through hierarchical colloidal self-assembly of nanoparticles. This is achieved by homogenization of a rod-like cellulose nanocrystal (CNC) with two immiscible, phase separating polyethylene glycol (PEG) and dextran polymer solutions. The dispersed CNCs exhibit unequal affinity for the binary polymer mixtures that depends on the balance of osmotic and chemical potential between the two phases. Once at the critical concentration, CNC particles are constrained within one component of the polymer phases and self-assemble into a cholesteric organization. The obtained liquid crystal emulsion demonstrates a confined three-dimensional percolating bicontinuous network with cholesteric self-assembly of CNC within the PEG phase; meanwhile, the nanoparticles in the dextran phase remain isotropic instead. Our results provide an alternative way to arrest bicontinuous structures through intraphase trapping and assembling of nanoparticles, which is a viable and flexible route to extend for a wide range of colloidal systems.


Assuntos
Cristais Líquidos , Nanopartículas , Celulose/química , Emulsões/química , Cristais Líquidos/química , Dextranos , Polímeros/química , Nanopartículas/química , Polietilenoglicóis , Água/química
9.
Skin Res Technol ; 29(11): e13513, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38009030

RESUMO

BACKGROUND: Oily skin, characterized by excessive sebum production, can lead to acne and have psychosocial impacts due to changes in appearance. Recent research has shown interest in treatments for oil control, with kaolin and bentonite emerging as promising options. Despite their potential, comprehensive studies on these ingredients are still in the nascent stages. AIM: This study aimed to assess the efficacy of a clay mask (La Roche-Posay Effaclar Sebo-Controlling Mask) in reducing skin oiliness and acne, and its safety for use. METHODS: In this study, 75 adults with oily or combination skin were enrolled and provided with a clay mask for twice-weekly use over 4 weeks. Clinical assessments, using instruments like Sebumeter, Vapometer, and Corneometer, were conducted at baseline, and after 1, 2, and 4 weeks, evaluating acne lesions, skin irritation, sebum content, and skin hydration. Participant self-assessment questionnaires were also utilized for subjective evaluation. Statistical analyses were performed accordingly. RESULTS: The study revealed significant improvements in acne-related outcomes, sebum content, skin evenness, stratum corneum water content, and transepidermal water loss following the application of the clay mask. Pore area and porphyrin area showed no significant changes. Tolerance assessment showed reduced dryness and irritation, with self-assessment indicating high product acceptability and perceived oil control effectiveness. CONCLUSION: This study demonstrated the clay mask's efficacy in managing acne and oily skin, improving hydration and texture. Significant improvements in skin parameters and high product safety were observed, supporting its suitability.


Assuntos
Acne Vulgar , Dermatite Seborreica , Adulto , Humanos , Argila , Pele , Acne Vulgar/terapia , Sebo , Água
10.
Cult Health Sex ; 25(4): 413-427, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35294853

RESUMO

Based on one-year's ethnographic fieldwork, this article unpacks experiences of assisted reproductive technology (ART) among queer parents and queer wannabe parents in Guangdong, China. Although existing state regulation on the use of ART and birth planning tends to deny parenthood to single and queer people and further limits their ability to form legible family units, queer parents who have had children through ART are growing in number in urban China. This research delineates how state and cultural conventions, together with market and economic conditions, have shaped queer individuals' decision making regarding whether, when and how to have children. Findings make an original contribution to studies of the use of reproductive technology in Chinese queer lives. Narratives regarding how queer parents employ ART services unscramble links between sexual citizenship and reproductive agency, as individuals make consumer choices and reproductive decisions synchronously. The paper also explores alleged LGBT-friendly ART companies and the image of a desirable 'rainbow baby' they have created. Chinese queer parents' participation in assisted reproduction has destabilised the dominant hetero-reproductive family matrix while simultaneously contributing to stratified reproduction.


Assuntos
Minorias Sexuais e de Gênero , Humanos , Pais , Técnicas de Reprodução Assistida , Comportamento Sexual , China
11.
J Integr Plant Biol ; 65(5): 1153-1169, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36573424

RESUMO

For adaptation to ever-changing environments, plants have evolved elaborate metabolic systems coupled to a regulatory network for optimal growth and defense. Regulation of plant secondary metabolic pathways such as glucosinolates (GSLs) by defense phytohormones in response to different stresses and nutrient deficiency has been intensively investigated, while how growth-promoting hormone balances plant secondary and primary metabolism has been largely unexplored. Here, we found that growth-promoting hormone brassinosteroid (BR) inhibits GSLs accumulation while enhancing biosynthesis of primary sulfur metabolites, including cysteine (Cys) and glutathione (GSH) both in Arabidopsis and Brassica crops, fine-tuning secondary and primary sulfur metabolism to promote plant growth. Furthermore, we demonstrate that of BRASSINAZOLE RESISTANT 1 (BZR1), the central component of BR signaling, exerts distinct transcriptional inhibition regulation on indolic and aliphatic GSL via direct MYB51 dependent repression of indolic GSL biosynthesis, while exerting partial MYB29 dependent repression of aliphatic GSL biosynthesis. Additionally, BZR1 directly activates the transcription of APR1 and APR2 which encodes rate-limiting enzyme adenosine 5'-phosphosulfate reductases in the primary sulfur metabolic pathway. In summary, our findings indicate that BR inhibits the biosynthesis of GSLs to prioritize sulfur usage for primary metabolites under normal growth conditions. These findings expand our understanding of BR promoting plant growth from a metabolism perspective.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Enxofre/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Nephrol Dial Transplant ; 37(10): 1982-1992, 2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34612498

RESUMO

BACKGROUND: Restless legs syndrome (RLS) is common among patients with end-stage kidney disease (ESKD) and is associated with poor outcomes. Several recently published studies had focused on pharmacological and non-pharmacological treatments of RLS, but an updated meta-analysis has not been conducted. METHODS: The study population was adult ESKD patients on dialysis with RLS. Randomized controlled trials (RCTs) were selected. The primary outcome was reduction in RLS severity. The secondary outcomes were improvement in sleep quality and treatment-related adverse events. Frequentist standard network meta-analysis (NMA) and additive component NMA were performed. The evidence certainty was assessed using the Confidence in NMA (CINeMA) framework. RESULTS: A total of 24 RCTs with 1252 participants were enrolled and 14 interventions were compared. Cool dialysate produced the largest RLS severity score reduction {mean difference [MD] 16.82 [95% confidence interval (CI) 10.635-23.02]} and a high level of confidence. Other potential non-pharmacological interventions include intradialytic stretching exercise [MD 12.00 (95% CI 7.04-16.97)] and aromatherapy massage [MD 10.91 (95% CI 6.96-14.85)], but all with limited confidence of evidence. Among the pharmacological interventions, gabapentin was the most effective [MD 8.95 (95% CI 1.95-15.85)], which also improved sleep quality [standardized MD 2.00 (95% CI 0.47-3.53)]. No statically significant adverse events were detected. CONCLUSIONS: The NMA supports that cool dialysate is appropriate to treat patients with ESKD and RLS. Gabapentin is the most effective pharmacological intervention and also might improve sleep quality. Further parallel RCTs with sufficient sample sizes are required to evaluate these potential interventions and long-term effects.


Assuntos
Falência Renal Crônica , Síndrome das Pernas Inquietas , Adulto , Soluções para Diálise , Gabapentina/uso terapêutico , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Metanálise em Rede , Diálise Renal/efeitos adversos , Síndrome das Pernas Inquietas/tratamento farmacológico , Síndrome das Pernas Inquietas/terapia
13.
Crit Rev Food Sci Nutr ; : 1-15, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36218329

RESUMO

Flavonoids are the most abundant polyphenols in plants, and have antioxidant effects as well as other bioactivities (e.g., anti-inflammatory, anti-cancer, anti-allergic, and neuroprotective effects). Vegetables are rich in flavonoids and are indispensable in our daily diet. Moreover, the vegetables as chassis for producing natural products would emerge as a promising means for cost-effective and sustainable production of flavonoids. Understanding the metabolic engineering of flavonoids in vegetables allows us to improve their nutrient composition. In this review, a comprehensive overview of flavonoids in vegetables, including the characterized types and distribution, health-promoting effects, associated metabolic pathways, and applied metabolic engineering are provided. We also introduce breakthroughs in multi-omics approaches that pertain to the elucidation of flavonoids metabolism in vegetables, as well as prospective and potential genome-editing technologies. Based on the varied composition and content of flavonoids among vegetables, dietary suggestions are further provided for human health.

14.
Ren Fail ; 44(1): 706-713, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35450507

RESUMO

Infective endocarditis (IE) is a serious infection and causes significant morbidity and mortality. However, the benefit of surgery for endocarditis besides antibiotic treatment in dialysis patients remains controversial. We performed a systematic review of studies published between 1960 and February 2022. Meta-analysis was conducted with a random-effects model to explore the in-hospital, 30, 60, 90, 180-d, and 1-year mortality rates in adult dialysis patients with IE. Sensitivity analysis, subgroup analysis, and meta-regression were performed to explore potential sources of heterogeneity. Confidence of evidence was evaluated by the GRADE system. Thirteen studies were included. The pooled odds ratio of in-hospital mortality was 0.62 (95% confidence interval [CI]: 0.30-1.28, p = .17), with moderate heterogeneity (I2 = 62%, p < .01). Three studies reported 30-d mortality, and the pooled odds ratio for surgery compared with medical treatment was even lower (0.36; 95% CI: 0.22-0.61, p < .01), with low heterogeneity (I2 = 0%, p = .86). With studies on fewer than 30 patients excluded, the sensitivity analysis revealed a low odds ratio of in-hospital mortality for surgery versus medical treatment (0.52; 95% CI: 0.27-0.99, p = .047), with moderate heterogeneity (I2 = 63%, p < .01). Subgroup analysis revealed no significant differences between any two comparator subgroups. Based on a very low strength of evidence, compared with medical treatment, surgical treatment for IE in patients on dialysis is not associated with lower in-hospital mortality. When studies on fewer than 30 patients were excluded, surgical treatment was associated with better survival.


Assuntos
Endocardite Bacteriana , Endocardite , Adulto , Antibacterianos/uso terapêutico , Endocardite/tratamento farmacológico , Endocardite/etiologia , Endocardite/cirurgia , Mortalidade Hospitalar , Humanos , Diálise Renal/efeitos adversos
15.
J Integr Plant Biol ; 64(5): 1007-1019, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35257500

RESUMO

The tryptophan (Trp)-derived plant secondary metabolites, including camalexin, 4-hydroxy-indole-3-carbonylnitrile, and indolic glucosinolate (IGS), show broad-spectrum antifungal activity. However, the distinct regulations of these metabolic pathways among different plant species in response to fungus infection are rarely studied. In this study, our results revealed that WRKY33 directly regulates IGS biosynthesis, notably the production of 4-methoxyindole-3-ylmethyl glucosinolate (4MI3G), conferring resistance to Alternaria brassicicola, an important pathogen which causes black spot in Brassica crops. WRKY33 directly activates the expression of CYP81F2, IGMT1, and IGMT2 to drive side-chain modification of indole-3-ylmethyl glucosinolate (I3G) to 4MI3G, in both Arabidopsis and Chinese kale (Brassica oleracea var. alboglabra Bailey). However, Chinese kale showed a more severe symptom than Arabidopsis when infected by Alternaria brassicicola. Comparative analyses of the origin and evolution of Trp metabolism indicate that the loss of camalexin biosynthesis in Brassica crops during evolution might attenuate the resistance of crops to Alternaria brassicicola. As a result, the IGS metabolic pathway mediated by WRKY33 becomes essential for Chinese kale to deter Alternaria brassicicola. Our results highlight the differential regulation of Trp-derived camalexin and IGS biosynthetic pathways in plant immunity between Arabidopsis and Brassica crops.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Brassica , Alternaria , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica/genética , Brassica/metabolismo , Brassica/microbiologia , Regulação da Expressão Gênica de Plantas , Glucosinolatos/metabolismo , Indóis/metabolismo , Redes e Vias Metabólicas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Fatores de Transcrição/metabolismo
16.
Nanotechnology ; 32(20): 205503, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33513596

RESUMO

Two-dimensional (2D) nanomaterials with catalytic activity have attracted considerable attention from researchers, but their application in the detection of hazardous substances needs to be further expanded. Herein, layered tungsten sulfide (WS2) nanosheets with peroxidase-mimicking activity were used to construct a colorimetric chemosensor for rapid detection of acetone. WS2 nanosheets can decompose H2O2 to generate hydroxyl radicals (·OH), which will further oxidize o-phenylenediamine (OPD) through hydrogen atom transfer (HAT) to form the yellow product 2,3-diaminophenazine. Acetone can block the HAT from OPD to ·OH, thus causing obvious inhibition of the peroxidase activity of WS2 nanosheets, making the solution appear pale yellow or even colorless. The investigation of catalytic kinetics indicates that the catalytic reaction consists of the 'ping pong' mechanism, and the regulatory effect of acetone on WS2 nanosheets is confirmed to be an irreversible inhibition. The chemosensor can easily distinguish a trace amount of acetone by the naked eye in less than 20 min, and has a limit of detection for acetone of as low as 3.08 mg  l-1. The application in actual samples displays the accuracy and stability of the chemosensor, suggesting that such a method is promising for acetone detection.

17.
Mikrochim Acta ; 187(2): 99, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912245

RESUMO

A colorimetric assay for the determination of heavy metal ions is presented that is based on the regulation of the oxidase-mimicking activity of Mn3O4 nanoparticles (NPs) by oligonucleotides. The chromogenic agent tetramethylbenzidine (TMB) is oxidized by the catalytic action of Mn3O4 NPs to generate products that have a yellow color in acidic solution, with a peak at 450 nm. It is found that random oligonucleotides are absorbed on the regular surface of the Mn3O4 NPs and temporarily inhibit the oxidation of TMB. This leads to a decrease in absorbance and a light-green coloration of the solution. The results show that the purine bases in oligonucleotides play a key role in their regulation of the activity of the NPs. The regulatory effect is assumed to be of the noncompetitive type. In the presence of heavy metal ions like Hg(II) or Cd(II), the inhibition is canceled due to the binding of heavy metal ions to thymine bases, and the color of the solution changes from light green to yellow. The increase in absorbance at 450 nm is related to the amount of heavy metal ions present. The method allows Hg(II) and Cd(II) to be determined visually in concentrations as low as 20 µg·L-1. The detection limit of the colorimetric assay is 3.8 and 2.4 µg·L-1 of Hg(II) and Cd(II), respectively. The assay displays good selectivity over other heavy metal ions. The method was successfully validated by analyzing several water samples. Graphical abstract Schematic representation of the colorimetric assay for Hg(II) and Cd(II) based on the intrinsic oxidase-mimicking activity of Mn3O4 nanoparticles that is regulated by oligonucleotides.


Assuntos
Técnicas Biossensoriais/métodos , Compostos de Manganês/química , Metais Pesados/análise , Nanopartículas/química , Óxidos/química , Poluentes Químicos da Água/análise , Benzidinas/química , Cádmio/análise , Compostos Cromogênicos/química , Colorimetria/métodos , Limite de Detecção , Mercúrio/análise , Oxirredutases/química
18.
Int J Mol Sci ; 21(23)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33256165

RESUMO

For a long time, cisplatin-based chemotherapy had been viewed as first-line chemotherapy for advanced and metastatic urothelial carcinoma (UC). However, many patients with UC had been classified as cisplatin-ineligible who can only receive alternative chemotherapy with poor treatment response, and the vast majority of the cisplatin-eligible patients eventually progressed, even those with objective response with cisplatin-based chemotherapy initially. By understanding tumor immunology in UC, immune checkpoint inhibitors, targeting on programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) pathways, had been proven as first-line treatment for cisplatin-ineligible metastatic UC and as second-line treatment for patients with platinum-refractory metastatic UC by the U.S Food and Drug Administration (FDA). In 2020, JAVEIN bladder 100 further reported that PD-L1 inhibitors showed benefits on prolonged survival and progression-free survival as maintenance therapy. Besides targeting on immune checkpoint, manipulation of the tumor microenvironment by metabolic pathways intervention, including inhibition on tumor glycolysis, lactate accumulation and exogenous glutamine uptake, had been investigated in the past few years. In this comprehensive review, we start by introducing traditional chemotherapy of UC, and then we summarize current evidences supporting the use of immune checkpoint inhibitors and highlight ongoing clinical trials. Lastly, we reviewed the tumor metabolic characteristic and the anti-tumor treatments targeting on metabolic pathways.


Assuntos
Redes e Vias Metabólicas , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/terapia , Urotélio/patologia , Ensaios Clínicos como Assunto , Humanos , Imunoterapia , Modelos Biológicos , Neoplasias da Bexiga Urinária/epidemiologia
19.
Anal Bioanal Chem ; 411(29): 7857-7868, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31705220

RESUMO

A novel colorimetric sensing platform based on the peroxidase activity of hemin regulated by oligonucleotide and pesticide was reported for the ultrasensitive and selective detection of isocarbophos. Oligonucleotides can accumulate on the surface of hemin in acid condition and temporarily inhibit its catalytic activity, which results in the loss of one electron of TMB molecule and produce the blue products. With the addition of isocarbophos, the pesticide molecules can interact with oligonucleotides to form some complexes, which relieve the inhibition of ssDNA to hemin and further enhance its catalytic activity. Thus, the TMB molecules are further oxidized to lose another electron and produce the yellow product in a few minutes, which has the characteristic absorption peak at 450 nm. The color change of the sensing system is related to the amount of isocarbophos, so this method can quickly discriminate whether the target pesticide exceeds the maximal residue limit just by naked eyes. To improve the performance of sensing platform, some important parameters like buffer condition and ssDNA have been investigated, and the peroxidase activity of hemin was further studied to verify the catalytic mechanism. The proposed sensing platform has a detection limit as low as 0.6 µg/L and displays good selectivity against other competitive pesticides. Moreover, the developed sensing platform also exhibits favorable accuracy and stability, indicating that it has potential applications in the detection of pesticide residues in agricultural products. Graphical abstract A novel colorimetric sensing platform based on oligonucleotides and pesticide regulation; the peroxidase catalytic activity of hemin was firstly reported for the ultrasensitive and selective detection of isocarbophos pesticide.


Assuntos
Colorimetria/métodos , Hemina/química , Malation/análogos & derivados , Oligonucleotídeos/farmacologia , Praguicidas/farmacologia , Verduras/química , Catálise , DNA de Cadeia Simples/química , Cinética , Limite de Detecção , Malation/análise
20.
Analyst ; 143(21): 5151-5160, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30251997

RESUMO

This paper reports a novel fluorescent aptasensor for the detection of acetamiprid pesticide with high sensitivity and selectivity based on the inner filter effect (IFE) of gold nanoparticles (AuNPs) toward fluorescent carbon dots (CDs). The aptasensor employs S-18 aptamer as the specific target recognition molecule and CDs as the signal transmission element. Free S-18 aptamer sequences can wrap the surfaces of AuNPs and enable their dispersion state even in the presence of high amounts of Tris-HCl salt, which can effectively quench the fluorescence of the CDs through the IFE. Upon adding acetamiprid pesticide, the free S-18 aptamer sequences are firstly exhausted to form some complexes; thus, the AuNPs tend to aggregate and their absorption spectrum no longer overlaps with the fluorescence emission spectrum of the CDs, which leads to obvious fluorescence recovery of the aptasensor. The properties of the CDs were extensively characterized, and the fluorescence quenching effects of the AuNPs toward the CDs were fully investigated. Additionally, the effects of some vital parameters, such as the type and amount of AuNPs, on the fluorescent aptasensor were also investigated. The proposed aptasensor has a detection limit as low as 1.08 µg L-1 with a linear range of 5 to 100 µg L-1 and shows high selectivity for acetamiprid over other control pesticides. Moreover, the aptasensor displays excellent accuracy and recovery in the detection of spiked real samples, suggesting that this fluorescent aptasensor can play important roles in the fields of food analysis and environmental detection.

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