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INTRODUCTION: Biomarkers are urgently required to identify peritoneal dialysis (PD) patients at risk of cardiovascular (CV) events. This study aimed to investigate the predictive value of soluble suppression of tumorigenicity-2 (sST2) for CV events in patients undergoing incident PD. METHODS: In this prospective cohort study, incident PD patients were enrolled. Blood samples to measure sST2 levels were obtained before PD catheter implantation. The patients underwent a standard peritoneal equilibration test (PET) after initiation of PD for 4-6 weeks. The sST2 levels both in serum and dialysate were determined using enzyme-linked immunosorbent assay. CV events were recorded during the follow-up period. RESULTS: A total of 137 patients were enrolled. During the follow-up period of 17.3 months, 49 (35.76%) patients experienced CV events. When patients were dichotomized based on the median values and the calculated cutoff values of sST2, the higher sST2 group had 2.980- and 3.048-fold increased risks of CV events, respectively, when compared with the lower sST2 group. Moreover, the prognostic value of sST2 remained significant as a continuous variable (per 1 standard deviation increase, hazard ratio [HR]=1.037, 95% confidence interval [CI] 1.010-1.066, P=0.008). N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were found to indicate a higher risk only when dichotomized based on the calculated cut-off values. Furthermore, serum sST2 and NT-proBNP levels simultaneously above the calculated cutoff values were associated with a higher risk of CV events (HR=3.398, 95% CI 1.813-6.367, P<0.001). CONCLUSION: Baseline serum sST2 level is an independent predictor of the risk of CV events in patients receiving incident PD, and in combination with NT-proBNP level, it can provide a more accurate predictive value.
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INTRODUCTION: Some biomarkers in drained dialyzate or peritoneal membrane have been found related to the dialyzate/plasma ratio of creatinine at 4 h (D/P Cr) in patients undergoing peritoneal dialysis (PD). But so far, there is no report on serum markers. Some biomarkers are associated with cardiovascular diseases (CVDs). Chemerin is a multifunctional chemoattractant adipokine which plays important roles in inflammation, adipogenesis, and metabolism. We intended to investigate the role of chemerin in the peritoneal membrane transport function and CVDs in incident PD patients. METHODS: This prospective cohort study was conducted in our PD center. The patients underwent initial standardized peritoneal equilibration test after PD for 4-6 weeks. Level of serum chemerin was determined via enzyme-linked immunosorbent assay. The patients' CVDs were recorded during the follow-up period. RESULTS: 151 eligible patients with a mean age of 46.59 ± 13.52 years were enrolled, and the median duration of PD was 25.0 months. The median concentration of serum chemerin was 29.09 ng/mL. Baseline D/P Cr was positively correlated with serum chemerin (r = 0.244, p = 0.003). The multivariate analyses revealed that serum chemerin (p = 0.002), age (p = 0.041), albumin (p = 0.000), and high-density lipoprotein (p = 0.022) were independent factors of D/P Cr. The serum chemerin level was significantly higher in diabetes mellitus (DM) patients than that of patients without DM (36.45 ng/mL vs. 27.37 ng/mL, p = 0.000), and there was a significant statistical difference in CVDs between the high chemerin group (≥29.09 ng/mL) and low chemerin group (<29.09 ng/mL) (42 vs. 21%, p = 0.009). CONCLUSIONS: Serum chemerin has a positive correlation with baseline D/P Cr in incident PD patients. It may be a biomarker that can predict the baseline transport function of the peritoneal membrane, and serum chemerin may be a risk factor of CVDs for incident PD patients. Multicenter studies with a larger sample size are warranted in the future.
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Diabetes Mellitus , Diálise Peritoneal , Adulto , Humanos , Pessoa de Meia-Idade , Biomarcadores , Soluções para Diálise , Peritônio/metabolismo , Estudos ProspectivosRESUMO
During urgent-start peritoneal dialysis (USPD) in end-stage renal disease (ESRD) patients, both adequate dialysis and skill training for fluid exchange are essential. However, automated peritoneal dialysis (APD) alone or manual fluid exchange peritoneal dialysis (MPD) alone could meet the above demands. Therefore, our study combined APD with MPD (A-MPD), and compared A-MPD with MPD, aiming to find the most appropriate treatment mode. This was a single-center, prospective, randomized controlled study. All eligible patients were randomized into the MPD and A-MPD groups. All patients underwent a five-day USPD treatment 48 h after catheter implantation, and they were followed up for six months after discharge. Overall, 74 patients were enrolled in this study. Among these, 14 and 60 patients quit due to complications during USPD and completed the study (A-MPD = 31, MPD = 29), respectively. Compared with MPD, the A-MPD treatment mode had a better effect on removing serum creatinine, blood urea nitrogen, and potassium and improving serum carbon dioxide combining power levels; it had less time expenditure on the fluid exchange by nurses (p < 0.05). In addition, patients in the A-MPD group had higher scores on the skill tests than those in the MPD group (p = 0.002). However, no significant differences in short-term peritoneal dialysis (PD) complications, PD technical survival rate, or mortality were found between the two groups. Therefore, the A-MPD mode could be recommended as an adoptable and suitable PD modality for USPD in the future.
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Falência Renal Crônica , Diálise Peritoneal , Humanos , Estudos Prospectivos , Falência Renal Crônica/terapia , Diálise Renal , Nitrogênio da Ureia SanguíneaRESUMO
Laccases (EC 1.10.3.2) are green biocatalysts with a considerable potential in numerous environmental and industrial applications due to their abilities to oxidize a wide range of substrates, such as aromatic amines, while reducing molecular oxygen to water. In this study, a putative laccase, LacMp1, encoding a protein of 48.3 kDa and belonging to the Cu-oxidase_3 superfamily, was cloned and overexpressed in Escherichia coli with a light-induced expression system. High-level expression of recombinant protein LacMp1 was achieved under the light intensity of 6500 ± 200 lx from a white light-emitting diode (LED) belt. The purified LacMp1 showed high activity toward various laccase substrates, with the lowest Km value and highest kcat/Km value for syringaldazine at the optimal temperature and pH of 50 °C and 7.5. Dimethyl sulfoxide, ethanol, and metal ions such as Co2+, Ca2+, K+, Li+, Zn2+, Mn2+, Fe3+, and Ni2+ did not significantly inhibit the activity of LacMp1. Furthermore, LacMp1 showed tolerance to NaCl and kept 66.67 ± 2.24% of its initial activity at concentrations lower than 400 mM. Moreover, LacMp1 exhibited wide-spectrum decolorization ability towards indigoid, anthraquinonic, and azo dyes without the aid of redox mediators at pHs ranging from 5.0 to 9.0. It decolorized 99.83 ± 0.12% of indigo carmine, 99.54 ± 0.43% of Congo red, 88.41 ± 3.22% of Eriochrome black T, and 51.61 ± 1.82% of Reactive blue 4, respectively. These unusual properties demonstrated that LacMp1 had potential in specific industrial or environmental applications.
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Escherichia coli , Lacase , Corantes/química , Escherichia coli/genética , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Lacase/química , Marinomonas , TemperaturaRESUMO
Recently, the application of metal-organic frameworks (MOFs) in thermal energy storage has attracted increasing research interests. MOF-ammonia working pairs have been proposed for controlling/sensing the air quality, while no work has yet been reported on the immense potential of MOFs for thermal energy storage up till now. Herein, the feasibility of thermal energy storage using seven MOF-ammonia working pairs is experimentally assessed. From ammonia sorption stability and sorption thermodynamics results, it is found that MIL-101(Cr) exhibits both high ammonia sorption stability and the largest sorption capacity of ≈0.76 g g-1 . Compared with MIL-101(Cr)-water working pair, MIL-101(Cr)-ammonia working pair improves the sorption capacity by over three times with evaporation temperature lower than 8.4 °C. Due to stable ammonia sorption stability and negligible hysteresis, MIL-101(Cr) and ZIF-8(Zn) are tested at condensation/evaporation temperature of 30 °C/10 °C. The thermal energy storage density (reaching over 1200 kJ kg-1 ) and coefficient of performance of MIL-101(Cr)-based system are both higher than ZIF-8(Zn)-based one due to larger average isosteric enthalpy and cycle sorption capacity. This experimental work paves the way for developing the high efficient and stable thermal energy storage system with MOF-ammonia working pairs especially for critical conditions with low evaporation temperature and high condensation temperature.
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BACKGROUND: Since the outbreak of COVID-19 in December 2019, it has spread rapidly and widely, bringing great psychological pressure to the public. In order to prevent the epidemic, traffic lockdown was required in many areas of China, which led to inconvenience of treatment for dialysis patients. This study was conducted to explore the psychological distress and the psychological demand induced by CO-VID-19 in the patients undergoing dialysis and compare the difference between hemodialysis (HD) and peritoneal dialysis (PD) patients during the traffic lockdown period. METHODS: Questionnaires were given to the dialysis patients in the West China Hospital of Sichuan University. The Impact of Event Scale (IES) was used to investigate the patients' trauma-related distress in response to COVID-19. RESULTS: 232 eligible respondents were enrolled in this cross-section study, consisting of 156 PD patients and 76 HD patients. The median IES score for all the enrolled patients was 8.00 (2.00-19.00), which belonged to the subclinical dimension of post-traumatic stress symptoms (PTSS). HD patients had a significant higher IES score than PD patients (11.50 vs. 8.00) (p < 0.05). HD patients already got more psychological support from the medical staff. According to IES scores, 22.4% HD patients and 13.4% PD patients were classified as having moderate or severe PTSS, which need psychological support (p < 0.05). But more patients of both groups considered psychological support was necessary (HD: 50%, PD: 45.5%) (p > 0.05). In the multivariate regression analysis, we found that dialysis vintage, the impact of COVID-19 on the severity of illness and daily life, and confidence in overcoming the disease contributed to IES score (p < 0.05). CONCLUSIONS: HD patients had more severe trauma-related stress symptoms than PD patients. When major public healthy events occurred, careful psychological estimate and sufficient psychological support should be provided to the dialysis patients, especially to the HD patients.
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COVID-19/psicologia , Falência Renal Crônica/terapia , Angústia Psicológica , Sistemas de Apoio Psicossocial , Quarentena/psicologia , Diálise Renal/psicologia , SARS-CoV-2 , Transtornos de Estresse Pós-Traumáticos/etiologia , Atividades Cotidianas , Adulto , COVID-19/prevenção & controle , Estudos Transversais , Feminino , Necessidades e Demandas de Serviços de Saúde , Hemodiálise no Domicílio/psicologia , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/psicologia , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal/psicologia , Relações Profissional-Paciente , Qualidade de Vida , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Inquéritos e Questionários , Centros de Atenção Terciária/estatística & dados numéricos , Índices de Gravidade do Trauma , Adulto JovemRESUMO
Environmental pollution affects human health, reduces work motivation, and addressing environmental pollution is a common challenge faced by the world. The Chinese government has recently implemented a new environmental policy - the national-level ecological economic zone - to develop a green economy and reduce environmental pollution. This study utilizes the difference-in-difference method to analyze the impact of the Dongting Lake ecological economic zone on environmental pollution. The results show that: policy led to a 68 % reduction in sulfur dioxide emissions. This impact was more pronounced in economically developed areas, regions with a high concentration of foreign-invested, and areas with greater economic openness. Mechanism tests indicate that the policy reduces environmental pollution by promoting technological progress. Robustness checks show that the policy also resulted in a 37 % reduction in industrial wastewater emissions. The results offer new insights to advance the development of the ecological economic zone more effectively. The ecological economic zone should focus on enhancing technological advancement and green total factor productivity to amplify the policy's positive effects.
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Background: Pancreatic ductal adenocarcinoma (PDAC) is frequently diagnosed in advanced stages, necessitating pancreaticoduodenectomy (PD) as a primary therapeutic approach. However, PD surgery can engender intricate complications. Thus, understanding the factors influencing postoperative complications documented in electronic medical records and their impact on survival rates is crucial for improving overall patient outcomes. Methods: A total of 749 patients were divided into two groups: 598 (79.84%) chose the RPD (Robotic pancreaticoduodenectomy) procedure and 151 (20.16%) chose the LPD (Laparoscopic pancreaticoduodenectomy) procedure. We used correlation analysis, survival analysis, and decision tree models to find the similarities and differences about postoperative complications and prognostic survival. Results: Pancreatic cancer, known for its aggressiveness, often requires pancreaticoduodenectomy as an effective treatment. In predictive models, both BMI and surgery duration weigh heavily. Lower BMI correlates with longer survival, while patients with heart disease and diabetes have lower survival rates. Complications like delayed gastric emptying, pancreatic fistula, and infection are closely linked post-surgery, prompting conjectures about their causal mechanisms. Interestingly, we found no significant correlation between nasogastric tube removal timing and delayed gastric emptying, suggesting its prompt removal post-decompression. Conclusion: This study aimed to explore predictive factors for postoperative complications and survival in PD patients. Effective predictive models enable early identification of high-risk individuals, allowing timely interventions. Higher BMI, heart disease, or diabetes significantly reduce survival rates in pancreatic cancer patients post-PD. Additionally, there's no significant correlation between DGE incidence and postoperative extubation time, necessitating further investigation into its interaction with pancreatic fistula and infection.
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Metal-organic frameworks (MOFs) are one of the most promising adsorbents in the adsorption cooling system (ACS) for their outstanding water adsorption performance. Notwithstanding that fact, numerous reports pay more attention to the ACS performance improvement through enhancing equilibrium water uptake of MOFs. However, adsorption cooling performance, including specific cooling power (SCP) and coefficient of performance for cooling (COPC) of MOF/water working pairs, always depends on the water adsorption kinetics of MOFs in ACS. In this work, to increase the water adsorption rate, the preparation of MOP/MIL-101(Cr) was achieved by encapsulating hydrophilic metal-organic polyhedral (MOP) into MIL-101(Cr). It was found that the hydrophilicity of MOP/MIL-101(Cr) was enhanced upon hydrophilic MOP3 encapsulation, resulting in a remarkable improvement in water adsorption rates. Furthermore, both SCP and COPC for MOP/MIL-101(Cr)-water working pairs were also improved because of the fast water adsorption of MOP/MIL-101(Cr). In brief, an effective approach to enhance the water adsorption rate and cooling performance of MOF-water working pairs through enhancing the hydrophilicity of MOFs by encapsulating MOP into MOFs was reported in this work, which provides a new strategy for broadening the application of MOF composites in ACS.
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Background: Prokinetic agents are currently considered the first-line therapy to improve gastric emptying when feeding intolerance occurred in critically ill adults. In this study, we developed a technique to assess the feasibility of predicting prokinetic agent efficacy in critically ill patients. Methods: The first images of each patient were obtained after EFI had occurred but before the first dose of prokinetic agents was administered and additional images were obtained every morning until the seventh day. The gastric antrum echodensity was recorded based on grayscale values (50th percentile, ED50; 85th percentile, ED85; mean, EDmean) and daily energy and protein intake was collected as the judgment for effective and ineffective group. A receiver operating characteristic curve was analyzed to distinguish the thresholds between the two groups and thus determine the ability of the gastric antrum echodensity to predict the efficacy of prokinetic agents. Results: In total, 83 patients were analyzed. Patients in the ineffective group had a higher ED50 (58.13 ± 14.48 vs. 49.88 ± 13.78, p < 0.001, difference 95% CI: 5.68, 10.82), ED85 (74.81 ± 16.41 vs. 65.70 ± 16.05, p < 0.001, difference 95% CI:6.16, 12.05), and EDmean (60.18 ± 14.31 vs. 51.76 ± 14.08, p < 0.001, difference 95% CI: 5.85, 11.00) than those in the effective group. Patients in the effective group more easily reached the target energy 16.21 ± 7.98 kcal/kg vs. 9.17 ± 6.43 kcal/kg (p < 0.001), 0.72 ± 0.38 g/kg vs. 0.42 ± 0.31 g/kg (p < 0.001) than in the ineffective group intake by day. Conclusion: The gastric antrum echodensity might serve as a tool for judging the efficacy of prokinetic agents, helping clinicians to decide whether to use prokinetic agents or place a post-pyloric tube when feeding intolerance occurs in critically ill patients.Clinical trial registration:http://www.chictr.org.cn/addproject2.aspx, ChiCTR2200058373. Registered 7 April 2022.
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A strategy for building ring-like deposit surface-enhanced Raman scattering (SERS) sensors with the coffee ring effect through the functional modification of the silica nanoparticle surface encapsulated by free-tagged Ag nanoparticles is addressed along with their applications in the SERS-based detection and degradation of target species, including paraquat, diquat, and their free radicals. The nanogap formed by two interparticles with SERS hotspots provides a gigantic amplification signal for the Raman scattering intensity of the analyte molecule located approximately at the hotspots. The enhanced Raman spectrum signals of these target analytes were achieved through the hotspot region of the surface plasmon resonance (SPR) located on the embankment formed by self-aggregation of SiO2@Ag nanoparticles due to the coffee ring effect. Meanwhile, the intrinsic properties of Ag nanoparticles embedded onto the silica surface were applied to photocatalytically degrade the target analytes by harvesting energy from sunlight. The SERS sensor detected the analytes down to 10-9 M in the aqueous solution.
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Herbicidas , Nanopartículas Metálicas , Diquat , Paraquat , Dióxido de Silício , PrataRESUMO
Herein, a strategy for a metal ion-imprinted artificial antibody with recognition sites tagged by fluorescein was carried out to construct the selective sites with a sensitive optical response signal to the specific metal ion. The synthesized silica nanoparticles were modified by the derivative residue group of 3-aminopropyltriethoxysilane conjugated with a 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) molecule through the hydrolysis and condensation reactions. The as-prepared silica nanoparticles were encapsulated by metal ion (Cu2+, Cd2+, Hg2+, and Pb2+)-imprinted polymers with nanostructured layers through the copolymerization of ethyl glycol dimethyl methacrylate (EGDMA) as a cross-linker, AIBN as an initiator, metal ions as template molecules, AA as a functional monomer, and acetonitrile as a solvent. The layers of molecular imprinted polymers (MIPs) with a core-shell structure removed template molecules by EDTA-2Na to retain the cavities and spatial sizes to match the imprinted metal ions. The microsensor arrays were achieved by the self-assembly technique of SiO2@MIP nanoparticles on the etched silicon wafer with regular dot arrays. The nanostructured-shell layers with fluorescence-tagged recognition sites rebound metal ions by the driving force of concentration difference demonstrates the high selective recognition and sensitive detection to heavy metal ions through the decline of fluorescence intensity. The LOD concentration for four metal ions is down to 10-9 mol·L-1. The method will provide biomimetic synthesis, analyte screen, and detection of highly dangerous materials in the environment for theoretical foundation and technological support.
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Anticorpos/química , Materiais Biomiméticos/química , Fluorescência , Metais Pesados/análise , Microtecnologia , Nanoestruturas/química , Materiais Biomiméticos/síntese química , Íons/análise , Teste de Materiais , Impressão Molecular , Polímeros/química , Dióxido de Silício/química , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
Adsorption-driven osmotic heat engines offer an alternative way for harvesting low-grade waste heat below 80°C. In this study, we performed a high-throughput computational screening based on grand canonical Monte Carlo simulations to identify the high-performance metal-organic frameworks (MOFs) from 1322 computationally ready experimental MOF structures for adsorption-driven osmotic heat engines with LiCl-methanol as the working fluid. Structure-property relationship analysis reveals that MOFs exhibiting high energy efficiency possess large working capacity, pore size and surface area, and moderate adsorption enthalpy comparable to the evaporation enthalpy. Furthermore, machine learning is employed to accelerate the computational screening for satisfied MOFs via the structure properties. The optimal structure properties of the MOFs are further identified via the ensemble-based regression model by optimizing the energy efficiency via the genetic algorithm, which shed light on rationally designing and fabricating MOFs for desired heat-to-electricity conversion.
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Exploring high-performing adsorption-driven heat pumps (AHPs) remains a challenging task owing to the low working capacity, high regeneration temperature, and low energy efficiency of conventional adsorbents. Quick discovery of the novel promising adsorbents could help to improve the coefficient of performance of AHPs for heating (COPH) and cooling (COPC). Herein, we reported an approach to identify the high-performing covalent-organic frameworks (COFs) for heating, cooling, and ice making by high-throughput computational screening based on grand canonical Monte Carlo simulations and, for the first time, machine learning. It was demonstrated that compared with metal-organic frameworks (MOFs), COFs were more suitable adsorbents of AHPs for cooling because of their weak interaction toward ethanol that favors stepwise adsorption. Structure-property relationship analysis revealed that the average enthalpy of adsorption commensurate with the enthalpy of evaporation will benefit the performance of AHPs besides the high working capacity and low step positions of adsorption isotherms. In order to reduce the computational cost of screening, a random forest model was developed to successfully predict the COPC of both COFs and MOFs.
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The thermal conductivity measurement of metal-organic frameworks (MOFs), which plays an important role in thermal management of MOF-based gas separation, storage, and thermal energy conversion (e.g., adsorption heat pumps), has been a challenging task for decades. However, the direct thermal conductivity measurement of a single-crystal MOF is currently limited by their small crystal sizes, since no sophisticated approach has ever been reported. In this study, the Raman-resistance temperature detectors (Raman-RTDs) method was developed for in situ measuring of the thermal conductivity of single-crystal ZIF-8, whose system error resulting from the thermal contact resistance between sample and RTDs can be eliminated. According to the dependence of thermal resistance of MOF crystals on the laser spot location, the thermal conductivities of polycrystalline and single-crystal ZIF-8 were derived to be 0.21 ± 0.03 and 0.64 ± 0.09 W/(m·K), respectively. The proposed in situ thermal conductivity measurement method may be further extended to other types of microscale particles.
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As an important cholesterol oxide, 7-ketocholesterol plays a deleterious role in the occurrence of cancer. Although the fact had been proved that 7-ketocholesterol could induce several biological phenomena, including apoptosis, DNA damage, et al., this issue whether 7-ketocholesterol led to mutagenesis in mammalian cells remains largely unexplored. Here, we investigated the major role of lipid peroxidation in the genotoxic response to 7-ketocholesterol in chinese hamster ovary (CHO) cells. The results showed that 7-ketocholesterol induced gene mutation and DNA double-strand breaks (DSBs) in concentration- and time-dependent manner. After CHO cells were treated with 25 µM 7-ketocholesterol for 48 h, the mutation frequency at hprt gene loci and the level of γ-H2AX protein were both significantly increased. Exposure to 7-ketocholesterol resulted in a concentration-dependent increase in the apoptotic rate and the protein expression of cleaved caspase-3 and -7 in CHO cells. Moreover, a significant increase of superoxide dismutase (SOD) activity and content of malondialdehyde (MDA) was also observed. Using a inhibitor of lipid peroxidation (butylated hydroxytoluene), it was found to remarkably inhibit the genotoxicity and MDA levels caused by 7-ketocholesterol. These findings indicated that lipid peroxidation was involved in the mutagenic process of 7-ketocholesterol in CHO cells.
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Dano ao DNA/efeitos dos fármacos , Cetocolesteróis/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Animais , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Cricetinae , Cricetulus , Dano ao DNA/fisiologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/toxicidade , Peroxidação de Lipídeos/fisiologia , Testes de Mutagenicidade/métodosRESUMO
Ultrasonic solvent extraction (USE) of pesticide multi-residues including monocrotophos, dimethoate, imidacloprid, carbendazim, carbaryl and simazine from leafy vegetables is presented. The extraction procedure was optimized with regard to the solvent type and amount, sonication time and number of extraction steps. The extract did not need clean-up before injected into liquid chromatography-tandem mass spectrometry (LC-MS-MS) which was employed together with electron microscope to verify the effect of USE method. The proposed procedure allows the extraction of six pesticide residues in a single step with 40 ml of ethyl acetate for 35 min sonication, providing recovery over 83% and LOQ less than 1.4 microg/kg. The optimized USE method is a simple, low cost and an effective preparation method for determination of pesticide multi-residues at trace levels in leafy vegetables in comparison with homogenized extraction method.
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Resíduos de Praguicidas/análise , Ultrassom , Verduras/metabolismo , Acetatos/análise , Cromatografia Líquida/métodos , Análise de Alimentos , Contaminação de Alimentos , Espectrometria de Massas/métodos , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Praguicidas/análise , Praguicidas/química , Reprodutibilidade dos Testes , Solventes/química , Fatores de TempoRESUMO
Needle-free injection (NFI), as an alternative drug delivery strategy, owns great potential. It is able to reduce complaints about needle phobia and avoid the occurring of accidental needle stick injuries. The nozzle diameter is inherently important in determining the injection dose, injection depth, and pain associated with NFIs. In this work, needle-free injectors with nozzle diameters of 0.17, 0.20, 0.30, 0.40, and 0.50 mm were studied in the simulation and experiment. This article optimizes the mathematical model for spring-powered NFI by considering the hydraulic loss due to the abrupt change in the nozzle exit area and the friction force between the piston and ampoule. We explore the dispersion pattern in gels with different nozzle diameters. Mice insulin injection was conducted to investigate the pharmacological effect of different injection methods. The experimental results show that there is the best dispersion effect and available injection depth while the nozzle diameter is 0.30 mm, which is in agreement with the result predicted by the mathematical model. Also, there is a satisfactory pharmacological effect on the mice insulin injection under the same injection condition. Undoubtedly, the mathematical model is capable of predicting the suitable nozzle diameter under the given conditions.