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1.
Mikrochim Acta ; 191(8): 505, 2024 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-39097544

RESUMO

A novel and sensitive fluorescence ratiometric method is developed for urea detection based  on the pH-sensitive response of two fluorescent carbon dot (CD) systems: R-CDs/methyl red (MR) and NIR-CDs/Cu2+. The sensing mechanism involves breaking down urea using the enzyme urease, releasing ammonia and increasing pH. At higher pH, the fluorescence of NIR-CDs is quenched due to the enhanced interaction with Cu2+, while the fluorescence of R-CDs is restored as the acidic MR converts to its basic form, removing the inner filter effect. The ratiometric signal (F608/F750) of the R-CDs/MR and NIR-CDs/Cu2+ intensities changed in response to the pH induced by urea hydrolysis, enabling selective and sensitive urea detection. Detailed spectroscopic and morphological investigations confirmed the fluorescence probe design and elucidated the sensing mechanism. The method exhibited excellent sensitivity (0.00028 mM LOD) and linearity range (0.001 - 8.0 mM) for urea detection, with successful application in milk samples for monitoring adulteration, demonstrating negligible interference and high recovery levels (96.5% to 101.0%). This ratiometric fluorescence approach offers a robust strategy for selective urea sensing in complicated matrices.


Assuntos
Carbono , Cobre , Corantes Fluorescentes , Limite de Detecção , Pontos Quânticos , Espectrometria de Fluorescência , Ureia , Urease , Ureia/análise , Ureia/química , Urease/química , Cobre/química , Carbono/química , Concentração de Íons de Hidrogênio , Pontos Quânticos/química , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Animais , Leite/química , Compostos Azo/química , Contaminação de Alimentos/análise
2.
Front Endocrinol (Lausanne) ; 15: 1416234, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39145313

RESUMO

Objective: To investigate the factors influencing accelerated aging in patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). Methods: A total of 216 patients diagnosed with T2DM and CHD between August 2019 and August 2023 at Xuzhou Central Hospital were selected. Patients were divided into an aging group and a non-aging group, based on the positive or negative values of phenotypic age acceleration (PhenoAgeAccel). Logistic regression analysis was conducted. Variables that had a univariate analysis P< 0.05 were included in the multivariate analysis to identify factors influencing aging in patients with T2DM and CHD, and the area under the curve of the model was reported. Results: This study included 216 patients, with 89 in the accelerated aging group, and 127 in the non-accelerated aging group. The average age of patients was 70.40 (95% CI: 69.10-71.69) years, with 137 males (63.4%). Compared with the non-accelerated aging group, patients in the accelerated aging group were older, with a higher proportion of males, and a higher prevalence of hypertension, stable angina pectoris, and unstable angina pectoris. Multivariate Logistic regression analysis indicated that the absolute value of neutrophils (NEUT#), urea (UREA), adenosine deaminase (ADA), and the triglyceride-glucose index (TyG) were risk factors for accelerated aging, while cholinesterase (CHE) was a protective factor. For each unit increase in NEUT#, UREA, ADA, and TyG, the risk of aging increased by 64%, 48%, 10%, and 789%, respectively. The overall area under the receiver operating characteristic (ROC) curve of the model in the training set was 0.894, with a 95% confidence interval (CI) of 0.851-0.938. Conclusion: NEUT#, CHE, UREA, ADA, and TyG are predictors of accelerated aging in patients with T2DM and CHD, with the model showing favorable overall predictive performance.


Assuntos
Doença das Coronárias , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/complicações , Masculino , Feminino , Idoso , Doença das Coronárias/epidemiologia , Doença das Coronárias/sangue , Pessoa de Meia-Idade , Senilidade Prematura/epidemiologia , Fatores de Risco , Envelhecimento , Triglicerídeos/sangue , China/epidemiologia , Adenosina Desaminase/metabolismo , Ureia/sangue
3.
BMC Pharmacol Toxicol ; 25(1): 50, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39138519

RESUMO

This study reports a novel, eco-friendly; fast and cost-effective microwave method for synthesizing carboxymethylated graphene oxide (CMGO) from sugarcane residues. Fourier-transform infrared spectroscopy (FTIR) confirmed successful CMGO synthesis through the presence of characteristic peaks at 1567.93 and 1639.29 cm-1 (COONa vibrations) and increased CH2 intensity compared to unmodified graphene oxide (GO). Furthermore, CMGO derived from sugarcane residues demonstrated potential in mitigating the side effects of toxic materials like carbon tetrachloride (CCl4). Treatment with CMGO partially reduced elevated levels of liver enzymes (ALT and AST) and nitrogenous waste products (urea and uric acid) in CCl4-induced liver damage models, suggesting an improvement in liver function despite ongoing cellular damage.This work paves the way for a sustainable and economical approach to produce functionalized graphene oxide with promising biomedical applications in alleviating toxin-induced liver injury.


Assuntos
Tetracloreto de Carbono , Doença Hepática Induzida por Substâncias e Drogas , Grafite , Fígado , Micro-Ondas , Grafite/química , Animais , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/metabolismo , Tetracloreto de Carbono/toxicidade , Masculino , Substâncias Protetoras/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/uso terapêutico , Ácido Úrico , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Ureia/análogos & derivados , Ureia/farmacologia , Camundongos
5.
Cell Biol Toxicol ; 40(1): 64, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096436

RESUMO

BACKGROUND AND PURPOSE: Colorectal cancer (CRC) is a widespread malignancy with a complex and not entirely elucidated pathogenesis. This study aims to explore the role of Bifidobacterium in the urea cycle (UC) and its influence on the progression of CRC, a topic not extensively studied previously. EXPERIMENTAL APPROACH: Utilizing both bioinformatics and experimental methodologies, this research involved analyzing bacterial abundance in CRC patients in comparison to healthy individuals. The study particularly focused on the abundance of BA. Additionally, transcriptomic data analysis and cellular experiments were conducted to investigate the impact of Bifidobacterium on ammonia metabolism and mitochondrial function, specifically examining its regulation of the key UC gene, ALB. KEY RESULTS: The analysis revealed a significant decrease in Bifidobacterium abundance in CRC patients. Furthermore, Bifidobacterium was found to suppress ammonia metabolism and induce mitochondrial dysfunction through the regulation of the ALB gene, which is essential in the context of UC. These impacts contributed to the suppression of CRC cell proliferation, a finding corroborated by animal experimental results. CONCLUSIONS AND IMPLICATIONS: This study elucidates the molecular mechanism by which Bifidobacterium impacts CRC progression, highlighting its role in regulating key metabolic pathways. These findings provide potential targets for novel therapeutic strategies in CRC treatment, emphasizing the importance of microbiota in cancer progression.


Assuntos
Bifidobacterium , Neoplasias Colorretais , Ureia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/patologia , Bifidobacterium/metabolismo , Humanos , Ureia/metabolismo , Animais , Proliferação de Células , Amônia/metabolismo , Camundongos , Mitocôndrias/metabolismo , Linhagem Celular Tumoral , Masculino , Microbioma Gastrointestinal/fisiologia , Feminino
6.
Pediatr Dent ; 46(4): 277-284, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39123328

RESUMO

Purpose: The purpose of this study was to assess, in vitro, the color stability and bleaching response of three bulk-fill composite resins-Activa™, Tetric®-N-Ceram Bulk-Fill, and Filtek™ One Bulk-Fill???and one conventional composite resin, Filtek™ Z250, after immersion in commonly consumed carbonated beverages and subsequent home bleaching with 15 percent carbamide peroxide. Methods: Ninety-six samples (two- and four-mm thick) of the materials were immersed in malt drink, energy drink, cola, or distilled water for one day, one week, and two months. After two months, samples underwent home bleaching with 15 percent carbamide peroxide gel. Spectrophotometric analysis measured color and whiteness changes pre-immersion, post-immersion, and post-bleaching. Statistical significance was determined using factorial mixed analysis of variance (ANOVA), three-way ANOVA, and Bonferroni post hoc tests (P<0.05). Results: All tested composite resins exhibited unacceptable discoloration (color change greater than 3.3) after two months in carbonated beverages. Filtek™ One Bulk-Fill and Filtek™ Z250 displayed the most significant discoloration, particularly when immersed in the malt drink (P<0.05). In contrast, Activa™ samples reached unacceptable discoloration within just one week in malt and cola drinks. Home bleaching yielded limited whiteness recovery, with Activa™ presenting acceptable whiteness post-bleaching after staining with cola and energy drinks. Conclusions: This study highlights the aesthetic risks of prolonged carbonated beverage consumption and the limitations of the assessed home bleaching technique using 15 percent carbamide peroxide. Enhanced dental education on the dietary effects of some beverages on restorative materials is indicated by these findings.


Assuntos
Peróxido de Carbamida , Bebidas Gaseificadas , Cor , Resinas Compostas , Clareamento Dental , Clareamento Dental/métodos , Clareadores Dentários , Humanos , Peróxidos/efeitos adversos , Ureia/análogos & derivados , Ureia/efeitos adversos , Teste de Materiais , Espectrofotometria , Bebidas Energéticas
7.
Bull Exp Biol Med ; 177(2): 181-184, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39090467

RESUMO

We performed a comprehensive study of protein (total protein, medium-molecular-weight peptides, creatinine, and urea), purine (uric acid), and lipid (cholesterol, triglycerides) metabolism, activity of AST, ALT, and acid phosphatase in blood plasma of white male rats under conditions of restriction of motor activity up to 28 days. Patterns of changes in metabolic profile during hypokinesia were established: prevalence of catabolic processes and atherogenic shifts in the lipid spectrum with maximum manifestation on 14-21 days of the experiment.


Assuntos
Colesterol , Triglicerídeos , Animais , Masculino , Ratos , Triglicerídeos/sangue , Triglicerídeos/metabolismo , Colesterol/sangue , Colesterol/metabolismo , Ácido Úrico/sangue , Ácido Úrico/metabolismo , Atividade Motora/fisiologia , Metaboloma/fisiologia , Metabolismo dos Lipídeos/fisiologia , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/metabolismo , Alanina Transaminase/sangue , Alanina Transaminase/metabolismo , Creatinina/sangue , Fosfatase Ácida/metabolismo , Fosfatase Ácida/sangue , Ureia/sangue , Hipocinesia/metabolismo , Hipocinesia/fisiopatologia
8.
Int J Mol Sci ; 25(15)2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39126049

RESUMO

T5 is a siphophage that has been extensively studied by structural and biochemical methods. However, the complete in situ structures of T5 before and after DNA ejection remain unknown. In this study, we used cryo-electron microscopy (cryo-EM) to determine the structures of mature T5 (a laboratory-adapted, fiberless T5 mutant) and urea-treated empty T5 (lacking the tip complex) at near-atomic resolutions. Atomic models of the head, connector complex, tail tube, and tail tip were built for mature T5, and atomic models of the connector complex, comprising the portal protein pb7, adaptor protein p144, and tail terminator protein p142, were built for urea-treated empty T5. Our findings revealed that the aforementioned proteins did not undergo global conformational changes before and after DNA ejection, indicating that these structural features were conserved among most myophages and siphophages. The present study elucidates the underlying mechanisms of siphophage infection and DNA ejection.


Assuntos
Microscopia Crioeletrônica , DNA Viral , Ureia , DNA Viral/genética , Ureia/farmacologia , Ureia/química , Modelos Moleculares , Proteínas Virais/química , Proteínas Virais/metabolismo
9.
Med J Malaysia ; 79(4): 457-463, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39086344

RESUMO

INTRODUCTION: Hyperuricaemia is common in essential hypertension with varying results in different populations. This study sought to ascertain the association between serum uric acid levels and essential hypertension in Hospital Universiti Sains Malaysia (HUSM). MATERIALS AND METHODS: A case-control study design involving 132 subjects (88 subjects of hypertension patients for case group and 44 subjects for control group) aged 18 to 40 years old of both genders was conducted at HUSM primary care clinic and physician clinic from May 2020 to May 2021. Blood samples were collected from each of the case and control subjects and analysed for serum uric acid, urea, creatinine, total cholesterol, triglycerides, LDL and HDL on chemical analyser Architect c8000. The data were analysed by using SPSS Statistics 26.0 version. RESULTS: The proportion of subjects with hyperuricaemia in the case group was 48.9%. A significant difference in the uric acid levels between the case group (390.64±92.65µmol/L) and control group (352.09±86.07µmol/L), (p<0.05) was observed. There was no significant difference in the serum uric acid mean ± SD based on the duration of hypertension (<5 years and ≥5 years), (p=0.331) and stages of hypertension (p>0.05). In case group, significant correlations were established between uric acid and triglycerides (r=0.255, p<0.05), uric acid and HDL (r= -0.223, p<0.05), uric acid and urea (r=0.299, p<0.05), uric acid and creatinine (r=0.486, p<0.01). No correlation among uric acid and total cholesterol levels (p>0.05), uric acid and LDL (p>0.05). Serum uric acid was a vital variable in developing hypertension (p<0.05) but not when adapted for age and body mass index (BMI) (p>0.05). CONCLUSION: Serum uric acid was significantly elevated in essential hypertension. The significant associations were established between uric acid and triglycerides, HDL, urea and creatinine in essential hypertension. Serum uric acid was a vital variable to develop hypertension, but the association was weakened by other co-founders as age and BMI. A large-scale population-based study is required to truly conclude the association between serum uric acid levels and essential hypertension in our population.


Assuntos
Hipertensão Essencial , Hiperuricemia , Ácido Úrico , Humanos , Ácido Úrico/sangue , Masculino , Malásia , Feminino , Adulto , Estudos de Casos e Controles , Hipertensão Essencial/sangue , Adulto Jovem , Hiperuricemia/sangue , Adolescente , Creatinina/sangue , Ureia/sangue
10.
BMC Oral Health ; 24(1): 942, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39143460

RESUMO

AIM: This study compared the effectiveness of several techniques in restoring compromised bonding to recently bleached enamel. METHODS: Seventy-five healthy bovine incisors were divided into five groups (n = 15). Fifteen teeth (Group 1) remained intact, whereas 60 (Groups 2 to 5) underwent at-home bleaching with 16% carbamide peroxide. The bonding procedures were as follows: Group 1: Bonding of resin composite to unbleached enamel; Group 2: Bonding immediately after bleaching; Group 3: Application of a 10% sodium ascorbate solution for 10 min before bonding; Group 4: Enamel removal to the depth of 0.5 mm; and Group 5: Increased curing time of the bonding agent to 80 instead of 20 s. After 24 h, the specimens were subjected to micro-shear testing, and the failure mode was determined. RESULTS: ANOVA revealed a significant difference in bond strength among the groups (P < 0.001). The mean bond strength was significantly lower in group 2 than in other groups (P < 0.05), which showed comparable bond strength to each other (P > 0.05). Adhesive failure was the most predominant failure type in all groups. The mixed failure occurred with a frequency of 26.7% in groups 3 and 5. The Fisher's exact test revealed a significant difference in failure modes among the groups (P = 0.047). CONCLUSIONS: The three experimental procedures used in this study, including the application of 10% sodium ascorbate before bonding, enamel removal to the depth of 0.5 mm, and increasing the curing time of the bonding agent to 80 s, were effective in restoring the compromised bonding to recently bleached enamel.


Assuntos
Ácido Ascórbico , Peróxido de Carbamida , Resinas Compostas , Colagem Dentária , Esmalte Dentário , Peróxidos , Resistência ao Cisalhamento , Clareadores Dentários , Clareamento Dental , Ureia , Animais , Bovinos , Esmalte Dentário/efeitos dos fármacos , Clareamento Dental/métodos , Colagem Dentária/métodos , Peróxidos/farmacologia , Resinas Compostas/química , Ácido Ascórbico/farmacologia , Ureia/análogos & derivados , Ureia/farmacologia , Análise do Estresse Dentário , Fatores de Tempo , Teste de Materiais , Estresse Mecânico , Cimentos de Resina/química
11.
ACS Appl Mater Interfaces ; 16(31): 41321-41331, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39051622

RESUMO

The clearance of urea poses a formidable challenge, and its excessive accumulation can cause various renal diseases. Urease demonstrates remarkable efficacy in eliminating urea, but cannot be reused. This study aimed to develop a composite vector system comprising microcrystalline cellulose (MCC) immobilized with urease and metal-organic framework (MOF) UiO-66-NH2, denoted as MCC@UiO/U, through the dynamic defect generation strategy. By utilizing competitive coordination, effective immobilization of urease into MCC@UiO was achieved for efficient urea removal. Within 2 h, the urea removal efficiency could reach up to 1500 mg/g, surpassing an 80% clearance rate. Furthermore, an 80% clearance rate can also be attained in peritoneal dialyzate from patients. MCC@UiO/U also exhibits an exceptional bioactivity even after undergoing 5 cycles of perfusion, demonstrating remarkable stability and biocompatibility. This innovative approach and methodology provide a novel avenue and a wide range of immobilized enzyme vectors for clinical urea removal and treatment of kidney diseases, presenting immense potential for future clinical applications.


Assuntos
Celulose , Enzimas Imobilizadas , Estruturas Metalorgânicas , Ureia , Urease , Urease/química , Urease/metabolismo , Ureia/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Celulose/química , Estruturas Metalorgânicas/química , Humanos
12.
J Environ Manage ; 367: 121927, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39079497

RESUMO

Given the significance of nitrogen (N) as the most constraining nutrient in agro-ecosystems, it is crucial to develop an updated model for N fertilizers management to achieve higher crop yields while minimizing the negative impacts on the environment. Coated urea is touted as one of the most important controlled-release N fertilizers used in agriculture to reduce cropland emissions and improve nitrogen use efficiency (NUE) for optimal crop yields. The sustainability of coated urea depends on the trade-offs between crop productivity, NUE and greenhouse gas emissions (CO2, CH4 and N2O); however, role of various agro-edaphic factors in influencing these trade-offs remains unclear. To determine the effects of soil properties, climatic conditions, experimental conditions, and type of coated urea on greenhouse gas emissions, NH3 losses, crop productivity, and NUE, we conducted a meta-analysis using data from 76 peer-reviewed studies. Our results showed that the application of coated urea under field conditions contributed to a greater reduction in N2O emissions (-48.67%) and higher NUE (58.72%), but crop yields were not significant. Across different climate regions, subtropical monsoon climate showed a perceptible mitigation for CO2, CH4 and NH3 (-78.38%; -83.33%; -27.46%), while temperate climate reduced N2O emissions by -70.36%. For different crops, only rice demonstrated reduction in CO2, CH4, N2O and NH3 losses. On the other hand, our findings revealed a mitigating trade-off between CO2 and CH4 emissions on medium-textured soils and N2O emissions on fine-textured soils. A significant reduction in N2O and NH3 losses was evident when coated urea was applied to soils with a pH > 5.5. Interestingly, application of coated urea to soils with higher C/N ratios increased NH3 losses but showed a noticeable N2O reduction. We found that polymer-coated urea reduced CH4 and N2O emissions and NH3 losses at the expense of higher CO2 emissions. Moreover, application of a lower dose of coated urea (0-100 kg N ha-1) enhanced CO2 and CH4 mitigation, while N2O mitigation increased linearly with increasing dose of coated urea. Most importantly, our results showed that the application of coated urea leads to a large mismatch between NUE, crop yields and greenhouse gas mitigation. By and large, the application of coated urea did not correspond with higher crop yields despite significant reduction in the emissions and improved NUE. Overall, these results suggest that site-specific agro-edaphic conditions should be considered when applying coated urea to reduce these emissions and N volatilization losses for increasing NUE and crop yields.


Assuntos
Agricultura , Produtos Agrícolas , Fertilizantes , Gases de Efeito Estufa , Ureia , Agricultura/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Solo/química , Metano , Dióxido de Carbono/análise , Nitrogênio , Óxido Nitroso/análise
13.
Langmuir ; 40(31): 16502-16510, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39039728

RESUMO

An oral sorbent with high capacity for NH4+ is desirable in lowering the blood urea level and mitigating the dialysis burden for end-stage kidney disease (ESKD) patients. Zirconium phosphate (ZrP) is an amorphous cation ion exchanger with high NH4+ binding capacity as a sorbent material, but its selectivity to remove NH4+ is limited in the presence of other competing ions in water solution. We previously have developed a gas-permeable and hydrophobic perfluorocarbon coating on ZrP, which improves ZrP's NH4+ selectivity. However, the coating preparation procedure, a wet chemistry approach, is complicated and time-consuming, and more importantly, the large amount of usage of acetone poses a concern for the application of ZrP as an oral sorbent. In this study, we developed a solventless coating protocol that effectively coats ZrP with tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FOTS) via thermal vapor deposition (TVD) in a simplified manner. X-ray photoelectron spectroscopy (XPS) and contact angle measurements verify the two coatings are successfully deposited on the ZrP surface, and the coating condition was optimized based on an in vitro static binding study. The dynamic binding study of competing ions on Na-loaded ZrP with TVD coatings yields a maximum NH4+ removal (∼3.2 mequiv/g), which can be improved to ∼4.7 mequiv/g if H-loaded ZrP under the same coating condition is used in basic stock solutions. More importantly, both materials barely remove Ca2+ and show excellent acid resistance. The significant improvement in the NH4+ binding capacity and selectivity reported here establishes a highly promising surface modification approach to optimize oral sorbents for ESKD patients.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Ureia , Zircônio , Zircônio/química , Ureia/química , Membranas Artificiais , Humanos , Adsorção , Insuficiência Renal/terapia
14.
Org Lett ; 26(31): 6608-6613, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39072587

RESUMO

We report a minimalist gaseous sulfonyl-chloride-derived reagent for multicomponent bioconjugation with amine, phenol, or aniline reagents to afford urea or carbamate products. With the utilization of a gas-phase reagent for a reaction mediated by metal ions, a variety of biologically relevant molecules, such as saccharide, poly(ethylene glycol), fluorophore, and affinity tag, can be efficiently cross-linked to the N terminus or lysine side-chain amines on natural polypeptides or proteins.


Assuntos
Aminas , Aminas/química , Estrutura Molecular , Gases/química , Ureia/química , Carbamatos/química , Indicadores e Reagentes/química , Peptídeos/química , Compostos de Anilina/química , Polietilenoglicóis/química
15.
J Agric Food Chem ; 72(31): 17455-17464, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39072618

RESUMO

We tested the ability of wood distillate (WD) to interact with urea in agricultural soil. WD is a sustainable material that has been addressed as a promising alternative to synthetic soil corroborants. However, there is little information about the effect of WD on the nitrogen cycle. In this study, soils with different amounts of WD and with/without urea were tested for ammonium, urease, nitrate/nitrite, and potential nitrification activity at different points in a 30 day time frame. High concentrations of WD (1-2%) inhibited the hydrolysis of urea and the oxidation of ammonium to nitrate. Thermal desorption coupled to GC-MS and high-performance liquid chromatography-tandem mass spectrometry characterization allowed us to reveal that WD-urea interactions mainly involve lignin-derived compounds in the distillate, such as catechol, resorcinol, and syringol. This study provides the first evidence of a strong interaction between WD and urea in soil that could be used to develop slow-release fertilizers.


Assuntos
Fertilizantes , Madeira , Madeira/química , Ureia/química , Ureia/metabolismo , Urease/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Nitrificação , Compostos de Amônio/química
16.
Artigo em Inglês | MEDLINE | ID: mdl-39013608

RESUMO

The industrial amino acid production workhorse, Corynebacterium glutamicum naturally produces low levels of 2,3,5,6-tetramethylpyrazine (TMP), a valuable flavor, fragrance, and commodity chemical. Here, we demonstrate TMP production (∼0.8 g L-1) in C. glutamicum type strain ATCC13032 via overexpression of acetolactate synthase and/or α-acetolactate decarboxylase from Lactococcus lactis in CGXII minimal medium supplemented with 40 g L-1 glucose. This engineered strain also demonstrated growth and TMP production when the minimal medium was supplemented with up to 40% (v v-1) hydrolysates derived from ionic liquid-pretreated sorghum biomass. A key objective was to take the fully engineered strain developed in this study and interrogate medium parameters that influence the production of TMP, a critical post-strain engineering optimization. Design of experiments in a high-throughput plate format identified glucose, urea, and their ratio as significant components affecting TMP production. These two components were further optimized using response surface methodology. In the optimized CGXII medium, the engineered strain could produce up to 3.56 g L-1 TMP (4-fold enhancement in titers and 2-fold enhancement in yield, mol mol-1) from 80 g L-1 glucose and 11.9 g L-1 urea in shake flask batch cultivation. ONE-SENTENCE SUMMARY: Corynebacterium glutamicum was metabolically engineered to produce 2,3,5,6-tetramethylpyrazine followed by a design of experiments approach to optimize medium components for high-titer production.


Assuntos
Corynebacterium glutamicum , Meios de Cultura , Glucose , Engenharia Metabólica , Pirazinas , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Pirazinas/metabolismo , Engenharia Metabólica/métodos , Meios de Cultura/química , Glucose/metabolismo , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Lactococcus lactis/enzimologia , Carboxiliases/genética , Carboxiliases/metabolismo , Ureia/metabolismo
17.
Lab Chip ; 24(15): 3728-3737, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38953748

RESUMO

We present the development and validation of an impedance-based urine osmometer for accurate and portable measurement of urine osmolality. The urine osmolality of a urine sample can be estimated by determining the concentrations of the conductive solutes and urea, which make up approximately 94% of the urine composition. Our method utilizes impedance measurements to determine the conductive solutes and urea after hydrolysis with urease enzyme. We built an impedance model using sodium chloride (NaCl) and urea at various known concentrations. In this work, we validated the accuracy of the impedance-based urine osmometer by developing a proof-of-concept first prototype and an integrated urine dipstick second prototype, where both prototypes exhibit an average accuracy of 95.5 ± 2.4% and 89.9 ± 9.1%, respectively in comparison to a clinical freezing point osmometer in the hospital laboratory. While the integrated dipstick design exhibited a slightly lower accuracy than the first prototype, it eliminated the need for pre-mixing or manual pipetting. Impedance calibration curves for conductive and non-conductive solutes consistently yielded results for NaCl but underscored challenges in achieving uniform urease enzyme coating on the dipstick. We also investigated the impact of storing urine at room temperature for 24 hours, demonstrating negligible differences in osmolality values. Overall, our impedance-based urine osmometer presents a promising tool for point-of-care urine osmolality measurements, addressing the demand for a portable, accurate, and user-friendly device with potential applications in clinical and home settings.


Assuntos
Impedância Elétrica , Ureia , Urease , Ureia/urina , Ureia/química , Concentração Osmolar , Hidrólise , Humanos , Urease/metabolismo , Urease/química , Urinálise/instrumentação , Desenho de Equipamento
18.
Biochim Biophys Acta Proteins Proteom ; 1872(5): 141032, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39004159

RESUMO

The discovery of a subunit exchange in some oligomeric proteins, implying short-term dissociation of their oligomeric structure, requires new insights into the role of the quaternary structure in oligomeric protein stability and function. Here we demonstrate the effect of pH, protein concentration, and urea on the efficiency of GroES heptamer (GroES7) subunit exchange. A mixture of equimolar amounts of wild-type (WT) GroES7 and its Ala97Cys mutant modified with iodoacetic acid (97-carboxymethyl cysteine or CMC-GroES7) was incubated in various conditions and subjected to isoelectric focusing (IEF) in polyacrylamide gel. For each sample, there are eight Coomassie-stained electrophoretic bands showing different charges that result from a different number of included mutant subunits, each carrying an additional negative charge. The intensities of these bands serve to analyze the protein subunit exchange. The protein stability is evaluated using the transverse urea gradient gel electrophoresis (TUGGE). At pH 8.0, the intensities of the initial bands corresponding to WT-GroES7 and CMC-GroES7 are decreased with a half-time of (23 ± 2) min. The exchange decreases with decreasing pH and seems to be strongly hindered at pH 5.2 due to the protonation of groups with pK âˆ¼ 6.3, which stabilizes the protein quaternary structure. The destabilization of the protein quaternary structure caused by increased pH, decreased protein concentration, or urea accelerates the GroES subunit exchange. This study allows visualizing the subunit exchange in oligomeric proteins and confirms its direct connection with the stability of the protein quaternary structure.


Assuntos
Ureia , Concentração de Íons de Hidrogênio , Ureia/química , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Estabilidade Proteica , Focalização Isoelétrica
19.
Chem Biol Interact ; 399: 111143, 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39004389

RESUMO

Deregulated activation of the Wnt/ß-catenin pathway is observed in many types of human malignancies including colon cancer. Abrogation of the Wnt/ß-catenin pathway has been demonstrated as an effective way of inducing cancer cell death. Herein, a new isoxazolyl-urea (QR-5) was synthesized and examined its efficacy on the viability of colon cancer cell lines. QR-5 displayed selective cytotoxicity towards colon cancer cells over normal counterparts. QR-5 induced apoptosis as evidenced by elevation in sub-G1 cells, decrease in Bcl-2, MMP-9, COX-2, VEGF and cleavage of PARP and caspase-3. QR-5 reduced the mitochondrial membrane potential, decreased the expression of Alix and elevated the expression of ATF4 and CHOP indicating the induction of paraptosis. The inhibitor of apoptosis (Z-DEVD-FMK) and paraptosis (CHX) could not restore Alix expression and PARP cleavage in QR-5 treated cells, respectively suggesting the complementation between the two cell death pathways. QR-5 suppressed the expression of Wnt/ß-catenin pathway proteins which was also evidenced by the downregulation of nuclear and cytoplasmic ß-catenin. The dependency of QR-5 on ß-catenin for inducing apoptosis and paraptosis was demonstrated by knockdown experiments using ß-catenin specific siRNA. Overall, QR-5 induces apoptosis as well as paraptosis by mitigating the Wnt/ß-catenin axis in colon cancer cells.


Assuntos
Apoptose , Neoplasias do Colo , Ureia , Via de Sinalização Wnt , beta Catenina , Humanos , Apoptose/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/tratamento farmacológico , Linhagem Celular Tumoral , beta Catenina/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Ureia/análogos & derivados , Ureia/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Paraptose
20.
J Phys Chem Lett ; 15(30): 7620-7627, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39029245

RESUMO

We examined the effects of trimethylamine N-oxide (TMAO) and urea (known osmolytes) on the liquid-liquid phase separation (LLPS) of fused in sarcoma (FUS) and three FUS-LLPS states: LLPS states at atmospheric pressure with low- and high-salt concentrations and a re-entrant LLPS state above 2 kbar. Temperature- and pressure-scan turbidity measurements revealed that TMAO and urea contributed to stabilizing and destabilizing LLPS, respectively. These results can be attributed to the excluded volume effect of TMAO (preferential hydration) and preferential interaction of urea with proteins. Additionally, TMAO counteracted the effects of equimolar urea on LLPS, a phenomenon not previously reported. The concept of the m-value for osmolyte-induced protein folding and unfolding can be applied to the osmolyte's effects on LLPS. In conclusion, biomolecular LLPS can be modulated by preferential hydration and the interaction of small osmolytes with proteins, thereby facilitating LLPS formation, even in extreme environments characterized by high-salt, high-urea, and high-pressure conditions.


Assuntos
Metilaminas , Ureia , Metilaminas/química , Ureia/química , Água/química , Dobramento de Proteína , Proteínas/química , Temperatura , Separação de Fases
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