RESUMO
Osteoarthritis (OA) is a chronic degenerative joint disease that affects worldwide. Oxidative stress plays a critical role in the chronic inflammation and OA progression. Scavenging overproduced reactive oxygen species (ROS) could be rational strategy for OA treatment. Bilirubin (BR) is a potent endogenous antioxidant that can scavenge various ROS and also exhibit anti-inflammatory effects. However, whether BR could exert protection on chondrocytes for OA treatment has not yet been elucidated. Here, chondrocytes were exposed to hydrogen peroxide with or without BR treatment. The cell viability was assessed, and the intracellular ROS, inflammation cytokines were monitored to indicate the state of chondrocytes. In addition, BR was also tested on LPS-treated Raw264.7 cells to test the anti-inflammation property. An in vitro bimimic OA microenvironment was constructed by LPS-treated Raw264.7 and chondrocytes, and BR also exert certain protection for chondrocytes by activating Nrf2/HO-1 pathway and suppressing NF-κB signalling. An ACLT-induced OA model was constructed to test the in vivo therapeutic efficacy of BR. Compared to the clinical used HA, BR significantly reduced cartilage degeneration and delayed OA progression. Overall, our data shows that BR has a protective effect on chondrocytes and can delay OA progression caused by oxidative stress.
Assuntos
NF-kappa B , Osteoartrite , Humanos , NF-kappa B/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Bilirrubina/farmacologia , Lipopolissacarídeos/farmacologia , Osteoartrite/tratamento farmacológico , Osteoartrite/metabolismo , Inflamação/tratamento farmacológico , Condrócitos/metabolismo , Interleucina-1beta/farmacologiaRESUMO
Bacterial infections pose a significant risk to human health. Magnolol, derived from Magnolia officinalis, exhibits potent antibacterial properties. Synthetic biology offers a promising approach to manufacture such natural compounds. However, the plant-based biosynthesis of magnolol remains obscure, and the lack of identification of critical genes hampers its synthetic production. In this study, we have proposed a one-step conversion of magnolol from chavicol using laccase. After leveraging 20 transcriptomes from diverse parts of M. officinalis, transcripts were assembled, enriching genome annotation. Upon integrating this dataset with current genomic information, we could identify 30 laccase enzymes. From two potential gene clusters associated with magnolol production, highly expressed genes were subjected to functional analysis. In vitro experiments confirmed MoLAC14 as a pivotal enzyme in magnolol synthesis. Improvements in the thermal stability of MoLAC14 were achieved through selective mutations, where E345P, G377P, H347F, E346C, and E346F notably enhanced stability. By conducting alanine scanning, the essential residues in MoLAC14 were identified, and the L532A mutation further boosted magnolol production to an unprecedented level of 148.83 mg/L. Our findings not only elucidated the key enzymes for chavicol to magnolol conversion, but also laid the groundwork for synthetic biology-driven magnolol production, thereby providing valuable insights into M. officinalis biology and comparative plant science.
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Compostos Alílicos , Lignanas , Magnolia , Fenóis , Humanos , Magnolia/genética , Magnolia/química , Lacase , Lignanas/química , Compostos de Bifenilo/químicaRESUMO
Age-related variations in many regions and/or networks of the human brain have been uncovered using resting-state functional magnetic resonance imaging. However, these findings did not account for the dynamical effect the brain's global activity (global signal [GS]) causes on local characteristics, which is measured by GS topography. To address this gap, we tested GS topography including its correlation with age using a large-scale cross-sectional adult lifespan dataset (n = 492). Both GS topography and its variation with age showed frequency-specific patterns, reflecting the spatiotemporal characteristics of the dynamic change of GS topography with age. A general trend toward dedifferentiation of GS topography with age was observed in both spatial (i.e., less differences of GS between different regions) and temporal (i.e., less differences of GS between different frequencies) dimensions. Further, methodological control analyses suggested that although most age-related dedifferentiation effects remained across different preprocessing strategies, some were triggered by neuro-vascular coupling and physiological noises. Together, these results provide the first evidence for age-related effects on global brain activity and its topographic-dynamic representation in terms of spatiotemporal dedifferentiation.
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Mapeamento Encefálico , Longevidade , Humanos , Adulto , Mapeamento Encefálico/métodos , Estudos Transversais , Imageamento por Ressonância Magnética/métodos , Encéfalo/fisiologiaRESUMO
OBJECTIVE: To evaluate the feasibility of using an intrarectal Foley catheter during ultrasound-guided high-intensity focused ultrasound (US-HIFU) in patients with benign uterine diseases of the posterior wall beyond the HIFU therapeutic range. METHODS: Patients were treated with US-HIFU and lesion changes were monitored using contrast-enhanced MRI from June 2020 to September 2021. A Foley catheter was inserted into the rectum to facilitate a successful US-HIFU ablation. Complications and lesion responses were recorded during the treatment and follow-up. RESULTS: Thirteen patients with 14 lesions beyond the device's treatable area were enrolled. The average placement time and insertion depth of the intrarectal Foley catheter was 7.6 ± 2.7 min and 23.2 ± 7.6 cm, respectively. A median of 50 mL degassed water was injected into the Foley catheter balloon. All 14 lesions were successfully pushed into a treatable area and subjected to HIFU. The average treatment time, irradiation time, and total therapeutic energy of HIFU were 44.2 ± 17.3 min, 394.4 ± 295.7 s, and 73.3 ± 46.6 kJ, respectively. The mean non-perfusion volume (NPV) in all treated lesions was 23.2 ± 19.2 cm3, and the mean NPV ratio was 57.8 ± 16.9%. Major complications were not observed. CONCLUSION: Intrarectal Foley catheter-assisted US-HIFU is effective and safe. Its clinical application could benefit patients with benign uterine diseases outside the HIFU therapeutic range.
Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Leiomioma , Doenças Uterinas , Neoplasias Uterinas , Feminino , Humanos , Neoplasias Uterinas/cirurgia , Leiomioma/cirurgia , Resultado do Tratamento , Doenças Uterinas/diagnóstico por imagem , Doenças Uterinas/cirurgia , CatéteresRESUMO
Threat generalisation is an adaptive process that is essential for individual survival. In contrast, over-generalisation is a pathological process that underlies the development of anxiety disorders. Intolerance of uncertainty (IU) is an individual characteristic known to influence threat generalisation by altering the responses to threat in uncertain situations. However, how it affects contextual threat generalisation remains unclear. Here, we used a novel paradigm to investigate whether contextual threat generalisation varied between individuals depending on their IU level (high or low) and the predictability of a situation (predictable or unpredictable). We analysed shock expectancy in 82 participants (age: 18-27 years) during threat acquisition and generalisation. Results showed that compared with the low IU group, the high IU group exhibited increased contextual threat generalisation to threat-related cues in unpredictable situation. These findings suggest that IU could be a marker for anxiety disorder susceptibility, as well as a target for anxiety treatment.
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Ansiedade , Individualidade , Humanos , Adolescente , Adulto Jovem , Adulto , Incerteza , Transtornos de Ansiedade , Sinais (Psicologia)RESUMO
At present, the high re-combination rate of photogenerated carriers and the low redox capability of the photocatalyst are two factors that severely limit the improvement of photocatalytic performance. Herein, a dual Z-scheme photocatalyst bismuthzirconate/graphitic carbon nitride/silver phosphate (Bi2Zr2O7/g-C3N4/Ag3PO4 (BCA)) was synthesized using a co-precipitation method, and a dual Z-scheme heterojunction photocatalytic system was established to decrease the high re-combination rate of photogenerated carriers and consequently improve the photocatalytic performance. The re-combination of electron-hole pairs (e- and h+) in the valence band (VB) of g-C3N4 increases the redox potential of e- and h+, leading to significant improvements in the redox capability of the photocatalyst and the efficiency of e--h+ separation. As a photosensitizer, Ag3PO4 can enhance the visible light absorption capacity of the photocatalyst. The prepared photocatalyst showed strong stability, which was attributed to the efficient suppression of photo-corrosion of Ag3PO4 by transferring the e- to the VB of g-C3N4. Tetracycline was degraded efficiently by BCA-10% (the BCA with 10 wt.% of AgPO4) under visible light, and the degradation efficiency was up to 86.2%. This study experimentally suggested that the BCA photocatalyst has broad application prospects in removing antibiotic pollution.
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Antibacterianos , Luz , Catálise , TetraciclinaRESUMO
Concurrent hearing and genetic screening of newborns is expected to play important roles not only in early detection and diagnosis of congenital deafness, which triggers intervention, but also in predicting late-onset and progressive hearing loss and identifying individuals who are at risk of drug-induced HL. Concurrent hearing and genetic screening in the whole newborn population in Beijing was launched in January 2012. This study included 180,469 infants born in Beijing between April 2013 and March 2014, with last follow-up on February 24, 2018. Hearing screening was performed using transiently evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR). For genetic testing, dried blood spots were collected and nine variants in four genes, GJB2, SLC26A4, mtDNA 12S rRNA, and GJB3, were screened using a DNA microarray platform. Of the 180,469 infants, 1,915 (1.061%) were referred bilaterally or unilaterally for hearing screening; 8,136 (4.508%) were positive for genetic screening (heterozygote, homozygote, or compound heterozygote and mtDNA homoplasmy or heteroplasmy), among whom 7,896 (4.375%) passed hearing screening. Forty (0.022%) infants carried two variants in GJB2 or SLC26A4 (homozygote or compound heterozygote) and 10 of those infants passed newborn hearing screening. In total, 409 (0.227%) infants carried the mtDNA 12S rRNA variant (m.1555A>G or m.1494C>T), and 405 of them passed newborn hearing screening. In this cohort study, 25% of infants with pathogenic combinations of GJB2 or SLC26A4 variants and 99% of infants with an m.1555A>G or m.1494C>T variant passed routine newborn hearing screening, indicating that concurrent screening provides a more comprehensive approach for management of congenital deafness and prevention of ototoxicity.
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Testes Genéticos/métodos , Perda Auditiva/diagnóstico , Pequim , Teste em Amostras de Sangue Seco , Feminino , Predisposição Genética para Doença , Humanos , Recém-Nascido , MasculinoRESUMO
As a group of typical endocrine disrupters, phthalates are simultaneously present in a variety of environmental media and enter human body through multiple exposure pathways. In this study, field monitoring data were used to characterize the skin-air (Klg ), dust-air (Kd ), and PM2.5 -air (Kp ) partition coefficients of DiBP, DnBP, and DEHP. The median values of log(Klg ) in the summer and winter were 7.654 and 7.932, 7.265 and 7.902, 9.419 and 9.015 for DiBP, DnBP, and DEHP, respectively, and Klg was significantly higher in the winter. The median Kd (m3 /mg) in the summer (0.036-0.151 for DiBP, 0.021-0.036 for DnBP and 1.479-4.069 for DEHP) were significantly higher than the counterparts in the winter (0.027-0.065 for DiBP, 0.022-0.245 for DnBP, and 0.140-3.250 for DEHP). In addition, Kd was associated with material of surface and residence time of dust. The Kp values (m3 /µg) of DiBP, DnBP, and DEHP in the summer (0.053, 0.015, and 0.021) were also significantly higher than the counterparts in the winter (0.011, 0.004, and 0.025). The partition of phthalates was influenced by built environment, such as temperature, humidity, ventilation, indoor chemistry, smoking, and building age. Except Klg , there was substantial discrepancy between the estimates of K with empirical equations and the values of K based on field monitoring data in our study.
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Poluição do Ar em Ambientes Fechados , Dietilexilftalato , Humanos , Poeira , Dietilexilftalato/análiseRESUMO
BACKGROUND: This study aimed to assess the quality of global guidelines or consensus statements for newborn and childhood hearing screening, as well as to compare various guidelines between other countries and China. METHODS: A PROSPERO registered systematic review (number CRD42021242198) was conducted. Multiple electronic databases and government websites including PubMed, EMBASE, Web of Science, CENTRAL, Cochrane Library, and BMJ Best Practice were searched from inception until May 2021. The latest national and international guidelines, consensus statements, technical specifications, and recommendations regarding newborn or childhood hearing screening that were published in Chinese or English medical journals or elsewhere with the full version available online. The following information was extracted independently by two reviewers for comparative analysis: titles, authors, publication year, country, the source organization, and main key recommendations using systems for assigning the level of evidence and strength of recommendations. The quality of the guidelines was assessed by three independent reviewers using the Appraisal of Guidelines for Research and Evaluation, 2nd edition. Intraclass correlation coefficients (ICCs) were calculated to assess among-reviewer agreement. RESULTS: We assessed 15 newborn and 6 childhood hearing screening guidelines, respectively. Most newborn guidelines recommend the 1-3-6 guidelines and pre-discharge screening; however, the specific screening times differ. 93.33% of newborn hearing guidelines recommend "primary screening-re-screening-diagnosis-intervention" for well-babies while 73.33% of the guidelines recommend "initial screening-diagnosis-intervention" for newborns in neonatal intensive care unit (NICU); 33.33% of the newborn hearing guidelines recommended initial screening coverage of > 95% while 46.66% did not mention it. Further, 26.66% of the newborn hearing guidelines recommended a referral rate to diagnosis within 4% while 60% did not mention it. Regarding childhood hearing screening guidelines, the screening populations differed across guidelines (age range: 0-9 years); most guidelines recommend pediatric hearing screening for all preschoolers. Only 50% of the guidelines specify screening and re-screening techniques, including pure-tone hearing screening, OAE, tympanometry, and others. The "Clarity of Presentation" domain achieved the highest mean score, and the lowest was "Editorial Independence" both in newborn and childhood guidelines. Overall score of newborn hearing screening guidelines ranged from 3 (2018 Europe) to 7 (2019 America), with an average score of 5.33. Average score of childhood hearing screening guidelines was 4.78, with the score ranging from 4 (2017 England, 2012 Europe, 2016 WHO) to 6.67 (2011 America). ICC analysis revealed excellent agreement across 21 guidelines (> 0.75). CONCLUSIONS: These findings indicated newborn hearing screening guidelines had superior quality over childhood ones. Comparative analysis suggested that recommendations of the Chinese newborn and pediatric hearing screening protocols are consistent with the mainstream international opinion. Moreover, this analysis demonstrated that "Editorial Independence" and "Stakeholder Involvement" have the greatest opportunities for improvement. These results may help to advance the quality of hearing screening guidelines in clinical practice and guide evidence-based updates.
Assuntos
Testes Auditivos , Programas de Rastreamento , Criança , Pré-Escolar , China , Audição , Testes Auditivos/métodos , Humanos , Lactente , Recém-Nascido , Encaminhamento e ConsultaRESUMO
BACKGROUND: Preeclampsia (PE) is a condition of high blood pressure that is usually concurrent with proteinuria in pregnancy. PE complicates the management of both maternal and fetal health and contributes to most adverse pregnancy outcomes, but the mechanism underlying the development of PE remains unclear. In this study, we performed a case-control study to compare the gut microbiota of PE (n = 26), abnormal placental growth (APG, n = 25) and healthy pregnant women (n = 28) and analyzed the potential pathogenic role of gut microbiota in PE progression. RESULTS: The clinical pathophysiological state did not affect the bacterial diversity, while the compositions of the gut microbiota were significantly altered in both the PE and APG groups compared with healthy pregnant women. At the phylum level, TM7 was significantly increased in women with APG. Heterogeneity was observed at the genus level, especially in genera with positive LDA scores, suggesting the stage-dependent effect of gut microbiota on the development of PE. The beneficial bacterium Lactobacillus was markedly depleted in the PE and APG groups but was only correlated with blood pressure (BP) and proteinuria levels in the PE group. Two different bacterial taxa belonged to Lactobacillus showed different correlations (OTU255 and OTU784 were significantly related to PE and APG, respectively). CONCLUSIONS: Our results indicated that shifts in the gut microbiota might occur from the early stages of the development of PE, which is of possible etiological and therapeutic importance.
Assuntos
Disbiose/complicações , Disbiose/microbiologia , Pré-Eclâmpsia/microbiologia , Adulto , Bactérias/classificação , Estudos de Casos e Controles , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/fisiologia , Humanos , Placenta/patologia , Doenças Placentárias/microbiologia , Gravidez , RNA Ribossômico 16S/genéticaRESUMO
Metal-free catalysts are widely considered as promising alternatives to traditional metal-based catalysts, which can effectively activate peroxymonosulfate (PMS). In this study, a novel metal-free catalyst, carbonized polypyrrole (CPPy) was synthesized through high-temperature carbonization of PPy, easily achieving the in situ N doping without the addition of nitrogen sources. Tetracycline (TC) was selected as the target contaminant to assess the catalytic activity of the CPPy/PMS system. Enhanced catalytic activity was observed in CPPy/PMS over a wide pH range (3.0-9.0), and the removal rate of TC by CPPy-3/PMS reached 91.3% after 10 min. After regenerating the used catalyst, the catalytic activity was refreshed, implying its stability and recyclability. The catalytic degradation of TC by CPPy/PMS was mainly attributed to a non-radical process. CPPy, as an intermediary, grabbed electrons from the electron-donating groups of TC and transferred them to the PMS molecule. Thereafter, TC that lost electrons was oxidized and degraded, and the O-O bonds of PMS were destroyed by the transferred electrons to form SO42- and OH-. Moreover, Oâ 2- and 1O2 were involved in TC degradation. TC degradation pathway was investigated through HPLC-MS analysis. These findings provide a promising strategy for the construction of catalysts for PMS and environmental remediation.
Assuntos
Polímeros , Pirróis , PeróxidosRESUMO
Visual attention and visual working memory (VWM) are two major cognitive functions in humans, and they have much in common. A growing body of research has investigated the effect of emotional information on visual attention and VWM. Interestingly, contradictory findings have supported both a negative bias and a positive bias toward emotional faces (e.g., angry faces or happy faces) in the attention and VWM fields. We found that the classical paradigms-that is, the visual search paradigm in attention and the change detection paradigm in VWM-are considerably similar. The settings of these paradigms could therefore be responsible for the contradictory results. In this paper, we compare previous controversial results from behavioral and neuroscience studies using these two paradigms. We suggest three possible contributing factors that have significant impacts on the contradictory conclusions regarding different emotional bias effects; these factors are stimulus choice, experimental setting, and cognitive process. We also propose new research directions and guidelines for future studies.
Assuntos
Atenção/fisiologia , Emoções , Expressão Facial , Memória de Curto Prazo/fisiologia , Modelos Neurológicos , Ira , Eletroencefalografia , Felicidade , Humanos , Imageamento por Ressonância Magnética , FotografaçãoRESUMO
OBJECTIVE: To compare efficacy and safety of microbubble contrast agent (SonoVue) and transcatheter arterial chemoembolization (TACE) in combination with high-intensity focused ultrasound (HIFU) for treatment of patients with hepatocellular carcinoma (HCC). METHODS: According to our inclusion criteria, we retrospectively reviewed 52 patients with HCCs, and divided them into SonoVue group and TACE group. Tumors were examined by enhanced magnetic resonance imaging. Change of lesions, alpha-fetoprotein values, hepatic and renal function were measured pre- and postoperatively. Then, adverse events were observed and clinical follow-up was performed. RESULTS: Clinical efficacy and the majority of treatment parameters were similar, except for time and energy required for the first massive grey-scale changes in SonoVue group, which were significantly lower than those in TACE group (p < .05). For adverse events, only rate of fever (3.85%) in SonoVue group was significantly lower than that in TACE group (50.00%, p < .05). The 'diagnosis and treatment cycle' in SonoVue group (11.5 ± 2.9) was remarkably shorter than TACE group (22.7 ± 6.3, p < .05). Energy efficiency factor was positively correlated with distance from the deepest layer of lesion to the hepatic capsule or to the abdominal wall in SonoVue group, while that was negatively correlated with iodized oil deposition in TACE group. CONCLUSION: Using microbubble (SonoVue) in HIFU procedure has a similar therapeutic effect compared with TACE, and does not increase the risk of treatment. It might present a new strategy in clinical treatment, especially for patients with a smaller diameter of HCC.
Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Quimioembolização Terapêutica/métodos , Meios de Contraste/uso terapêutico , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Microbolhas/uso terapêutico , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Activated carbon (AC) was prepared from Platanus orientalis leaves by H3PO4 activation using a microwave heating method and characterized by SEM (scanning electron microscopy), Brunauer-Emmett-Teller (BET) surface area analysis and FTIR (Fourier transform infrared spectroscopy) techniques. AC exhibited a surface area of 1089.67 m2/g and a relatively high pore volume of 1.468 cm3/g. Utilization of AC for the removal of Cr(VI) from aqueous solution was researched. The adsorption efficiency was highly pH dependent and adsorption capacity of AC for Cr(VI) could reach up to 135.24 mg/g. Adsorption equilibrium could be quickly reached within 2 h. A kinetic study indicated that the adsorption of Cr(VI) conformed to the pseudo-second-order model (R2 > 0.99). An intraparticle diffusion model was applied to describe the adsorption kinetics, and the results showed that there are other factors that affect the rate. Chemical regeneration for AC saturated with Cr(VI) was performed and HNO3 displayed the best regeneration performance among the four chemical regeneration agents (HNO3, H2SO4, NaOH, NaCl). The regeneration performance increased at first and then decreased with the rise of HNO3 concentration, and regeneration reaction could reach equilibrium within 4 h in the first cycle. The FTIR spectra revealed that HNO3 successfully introduced N-H bonds onto the AC surface in the regeneration process.
Assuntos
Carvão Vegetal/química , Cromo/química , Folhas de Planta/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Cromo/análise , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análiseRESUMO
OBJECTIVE: The aim of the current study is to evaluate the bioequivalence between the test and reference formulations of memantine in a single-dose, two-period and two-sequence crossover study with a 44-day washout interval. MATERIALS AND METHODS: A total of 20 healthy Chinese male volunteers were enrolled and completed the study, after oral administration of single doses of 10 mg test and reference formulations of memantine. The blood samples were collected at different time points and memantine concentrations were determined by a fully validated HPLC-MS/MS method. The evaluated pharmacokinetic parameters (test vs. reference) including Cmax (18 ± 3.2 vs. 17.8 ± 3.4), AUC0-t (1,188.5 ± 222.2 vs. 1,170.9 ± 135.7), and AUC0-∞ (1,353.3 ± 258.6 vs. 1,291.3 ± 136.7) values were assessed for bioequivalence based on current guidelines. RESULTS: The observed pharmacokinetic parameters of memantine test drug were similar to those of the reference formulation. The 90% confidence intervals of test/reference ratios for Cmax, AUC0-t, and AUC0-∞ were within the bioequivalence acceptance range of 80 - 125%. CONCLUSION: The results obtained from the healthy Chinese subjects in this study suggests that the test formulation of memantine 10 mg tablet is bioequivalent to the reference formulation (Ebixa®10 mg tablet).â©.
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Memantina/farmacocinética , Administração Oral , Adulto , Área Sob a Curva , Povo Asiático , Disponibilidade Biológica , Química Farmacêutica/métodos , Estudos Cross-Over , Meia-Vida , Voluntários Saudáveis , Humanos , Masculino , Comprimidos/farmacocinética , Equivalência Terapêutica , Adulto JovemRESUMO
Activated carbons were derived from Enteromorpha prolifera immersed in H3PO4 solution or the H3PO4 solution mixed with sodium benzenesulfonate (SBS), producing AC and AC-SBS. NaOH solution was employed in regeneration of ciprofloxacin (CIP)-loaded AC and AC-SBS to obtain RAC and RAC-SBS. The properties of the original and regenerated activated carbons were characterized by thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), N2 adsorption/desorption isotherms and Fourier transform infrared spectroscopy (FTIR). Batched adsorption studies were carried out to compare CIP adsorption behaviors of the four carbons. The results suggested that the four samples exhibited higher proportions of mesopores and similar functional groups. Although AC displayed much higher specific surface area (SBET) (1045.79m2/g) than AC-SBS (738.03m2/g), its CIP adsorption capacity was much less than AC-SBS. The maximum adsorption capacity for AC, AC-SBS, RAC and RAC-SBS were found to be 250mg/g, 286mg/g, 233mg/g and 256mg/g, respectively, with the isotherms adhering to Langmuir isotherm model. The electrostatic attraction and cation exchange between CIP and the four carbons were the dominant adsorption mechanisms. Moreover, the thermodynamic parameters represented that the adsorption process had been confirmed to be a spontaneous and endothermic reaction.
Assuntos
Benzenossulfonatos , Carvão Vegetal/síntese química , Clorófitas/química , Ciprofloxacina/química , Ácidos Fosfóricos , Poluentes Químicos da Água/química , Adsorção , Carbono/química , Carvão Vegetal/química , Troca Iônica , Cinética , Microscopia Eletrônica de Varredura , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termodinâmica , Gerenciamento de Resíduos/métodosRESUMO
Er3+/Yb3+ codoped tellurite-zinc-niobium (TZNb) glass was prepared by the melt-quenching method and used for the construction of a point all-fiber temperature sensor. The glass thermal stability and network structural properties were studied by differential thermal analysis and Raman spectrum, respectively. High glass transition temperature is beneficial to widen the working temperature range. The dependence of fluorescence intensity ratio (FIR) of green upconversion emissions on the surrounding temperature from 276 to 363 K was experimentally investigated and the maximum temperature sensitivity is 95 × 10-4 K-1 at 363 K. Strong green upconversion emission, broad temperature measurement range and high sensitivity indicate this point temperature sensor is a promising optical device for application on optical temperature sensing.
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A rapid and sensitive liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to determine clonidine in human plasma was developed and fully validated. Sample preparation was involved an one-step extraction with diethyl ether. Donepezil was employed as the internal standard (IS). Chromatographic separation was performed on a Hypersil BDS C18 column (i.d. 2.1 × 50 mm, particle size 3µm) with a mobile phase of methanol-water (containing 0.1% formic acid; 60:40, v/v) at a flow rate of 200 µL/min. The peaks were detected by mass spectrometry using the electrospray ion source in selected reaction monitoring mode. The extraction recovery was 72.53-85.25%. The method was found to be linear in a concentration range of 0.02-6.00 ng/mL and the lower limit of quantification was 0.02 ng/mL. The within- and between-batch precisions at three concentrations were 4.33-16.47 and 7.24-17.24% with accuracies of -2.47-10.91 and 1.86-10.19%, respectively. This validated method was successfully used for a bioequivalence study of two clonidine transdermal patches on healthy volunteers. The results suggested that the test formulation of clonidine patch met the regulatory criterion for bioequivalence to the reference formulation, but a larger sample size should be needed for the estimation of bioequivalence.
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Cromatografia Líquida de Alta Pressão/métodos , Clonidina/sangue , Clonidina/farmacocinética , Adulto , Área Sob a Curva , Calibragem , Clonidina/administração & dosagem , Voluntários Saudáveis , Humanos , Masculino , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Equivalência Terapêutica , Adesivo TransdérmicoRESUMO
Airborne hexavalent chromium (Cr(VI)) is a known pulmonary carcinogen and can be emitted from both natural and anthropogenic sources, including diesel emissions. However, there is limited knowledge about ambient Cr(VI) concentration levels and its particle size distribution. This pilot study characterized ambient Cr(VI) concentrations in the New Jersey Meadowlands (NJ ML) district, which is close to the heavily trafficked New Jersey Turnpike (NJTPK) as well as Chromium Ore Processing Residue (COPR) waste sites. Monitoring was simultaneously conducted at two sites, William site (~50 m from NJTPK) and MERI site (~700 m from NJTPK). The distance between the two sites is approximately 6.2 km. Ambient Cr(VI) concentrations and PM2.5 mass concentrations were concurrently measured at both sites during summer and winter. The summer concentrations (mean ± S.D. [median]), 0.13 ± 0.06 [0.12] ng/m3 at the MERI site and 0.08 ± 0.05 [0.07] ng/m3 at the William site, were all significantly higher than the winter concentrations, 0.02 ± 0.01 [0.02] ng/m3 and 0.03 ± 0.01 [0.03] ng/m3 at the MERI and William sites, respectively. The site difference (i.e., MERI > William) was observed for summer Cr(VI) concentrations; however, no differences for winter and pooled datasets. These results suggest higher Cr(VI) concentrations may be attributed from stronger atmospheric reactions such as photo-oxidation of Cr(III) to Cr(VI) in the summer. The Cr(VI) distribution as a function of particle size, ranging from 0.18 to 18 µm, was determined at the William site. It was found that Cr(VI) was enriched in the particles less than 2.5 µm in diameter (PM2.5). This finding suggested potential health concerns, because PM2.5 are easily inhaled and deposited in the alveoli. A multiple linear regression analysis confirmed ambient Cr(VI) concentrations were significantly affected by meteorological factors (i.e., temperature and humidity) and reactive gases/particles (i.e., O3, Fe and Mn).
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Activated carbon was prepared from Enteromorpha prolifera (EP) by H3PO4 activation in the presence of doped cetyl trimethyl ammonium bromide (CTAB), producing EPAC-CTAB. The thermal decomposition process of the activated carbon substrate was identified by thermo-gravimetric analysis. Scanning electron microscope (SEM), N2 adsorption/desorption, Fourier transform infrared spectroscopy (FTIR), Boehm titration, and X-ray Photoelectron Spectroscopy (XPS) were employed to characterize the physicochemical properties of native EPAC and EPAC-CTAB. EPAC-CTAB exhibited smaller surface area (689.0m(2)/g) and lower total pore volume (0.361cm(3)/g) than those of EPAC (1045.8m(2)/g and 1.048cm(3)/g), while the number of acidic groups, oxygen and nitrogen groups on the surface of EPAC-CTAB increased through CTAB doping. The batch kinetics and isotherm adsorption studies of nickel(II) onto the adsorbents were examined and agreed well with the pseudo-second-order model and the Langmuir model. The maximum adsorption capacity determined from the Langmuir model was 16.9mg/g for EPAC and 49.8mg/g for EPAC-CTAB. Under acidic condition, the adsorption of nickel(II) onto EPAC and EPAC-CTAB was hindered due to ion competition and electrostatic repulsion. The results indicated that using CTAB as a dopant for EPAC modification could markedly enhance the nickel(II) removal.