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1.
Int J Phytoremediation ; : 1-10, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39254259

RESUMO

This study was aimed at evaluating the removal of different cationic dyes onto phosphoric acid-activated coconut shell carbon. The activated carbon was characterized for surface functional groups, thermal decomposition profiles, surface morphology, and textural properties. The specific area was recorded as 1,221 m2/g with 100% mesoporosity. On molecular basis, the activated carbon adsorbs malachite green, methylene blue, and rhodamine B at maximum capacities of 1.52 mmol/g, 0.80 mmol/g, and 0.58 mmol/g, respectively. It indirectly implies the selectivity of activated carbon toward malachite green, and behaves differently due to steric hindrance of dye molecules. All equilibrium data obeyed Langmuir model, while the kinetic data are closely fitted to pseudo-second order model as concentration increases. To conclude, coconut shell activated carbon is more effective to remove malachite green compared to methylene blue and rhodamine B.


This paper is expected to give a further insight into the valorization of coconut shell into activated carbon, and its re-purpose for the remediation of dye-contaminated streams, for which methylene blue, malachite green and rhodamine B were used as model pollutants. This study aims to contribute to the growing body of research on the selective removal of malachite green over the other two dyes onto coconut shell activated carbon, which to the best of our knowledge is still absent in the open literature.

2.
Molecules ; 29(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38930855

RESUMO

Zero-dimensional graphene quantum dots (GQDs) present unique optoelectronic properties in the large-spectrum range from UV to visible. However, the origin of luminescence in GQDs is still a debatable question. Therefore, the present work investigates the features of trap-mediated and edge-state-functionalized group-associated luminescence enhancement of GQDs. The attached functional groups' involvement in the upsurge of photoluminescence has been discussed theoretically as well as experimentally. In addition, the role of the aromatic ring, the functional group attached, and their positions of attachment to the aromatic ring to tune the emission wavelength and Raman modes have been elucidated theoretically as well as experimentally. We found that in the case of the -OH group attached outside of the aromatic ring, the long-range π hybridization dominates, which suggests that the emission from this model can be dictated by long-range π hybridization. In particular, we found that oxygen-containing functional groups attached outside of the aromatic ring are the main source of the luminescence signature in GQDs. Furthermore, density functional theory (DFT) indicates that the -OH functional group attached outside of the aromatic ring perfectly matched with our experimental results, as the experimental bandgap (2.407 eV) is comparable with the theoretical simulated bandgap (2.399 eV) of the -OH group attached outside of the aromatic ring.

3.
AJR Am J Roentgenol ; 221(6): 748-758, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37466185

RESUMO

BACKGROUND. Precontrast CT is an established means of evaluating for hepatic steatosis; postcontrast CT has historically been limited for this purpose. OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of portal venous phase postcontrast CT in detecting at least moderate hepatic steatosis using liver and spleen attenuation measurements determined by an automated artificial intelligence (AI) tool. METHODS. This retrospective study included 2917 patients (1381 men, 1536 women; mean age, 56.8 years) who underwent a CT examination that included at least two series through the liver. Examinations were obtained from an AI vendor's data lake of data from 24 centers in one U.S. health care network and 29 centers in one Israeli health care network. An automated deep learning tool extracted liver and spleen attenuation measurements. The reference for at least moderate steatosis was precontrast liver attenuation of less than 40 HU (i.e., estimated liver fat > 15%). A radiologist manually reviewed examinations with outlier AI results to confirm portal venous timing and identify issues impacting attenuation measurements. RESULTS. After outlier review, analysis included 2777 patients with portal venous phase images. Prevalence of at least moderate steatosis was 13.9% (387/2777). Patients without and with at least moderate steatosis, respectively, had mean postcontrast liver attenuation of 104.5 ± 18.1 (SD) HU and 67.1 ± 18.6 HU (p < .001); a mean difference in postcontrast attenuation between the liver and the spleen (hereafter, postcontrast liver-spleen attenuation difference) of -7.6 ± 16.4 (SD) HU and -31.8 ± 20.3 HU (p < .001); and mean liver enhancement of 49.3 ± 15.9 (SD) HU versus 38.6 ± 13.6 HU (p < .001). Diagnostic performance for the detection of at least moderate steatosis was higher for postcontrast liver attenuation (AUC = 0.938) than for the postcontrast liver-spleen attenuation difference (AUC = 0.832) (p < .001). For detection of at least moderate steatosis, postcontrast liver attenuation had sensitivity and specificity of 77.8% and 93.2%, respectively, at less than 80 HU and 90.5% and 78.4%, respectively, at less than 90 HU; the postcontrast liver-spleen attenuation difference had sensitivity and specificity of 71.4% and 79.3%, respectively, at less than -20 HU and 87.0% and 62.1%, respectively, at less than -10 HU. CONCLUSION. Postcontrast liver attenuation outperformed the postcontrast liver-spleen attenuation difference for detecting at least moderate steatosis in a heterogeneous patient sample, as evaluated using an automated AI tool. Splenic attenuation likely is not needed to assess for at least moderate steatosis on postcontrast images. CLINICAL IMPACT. The technique could promote early detection of clinically significant nonalcoholic fatty liver disease through individualized or large-scale opportunistic evaluation.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Tomografia Computadorizada por Raios X , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Inteligência Artificial
4.
Environ Res ; 216(Pt 2): 114524, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36228692

RESUMO

Road transport contributes over 70% of air pollution in urban areas and is the second largest contributor to the total carbon dioxide emissions in Malaysia at 21% in 2016. Transport-related air pollutants (TRAPs) such as NOx, SO2, CO and particulate matter (PM) pose significant threats to the urban population's health. Malaysia has targeted to deploy 885,000 EV cars on the road by 2030 in the Low Carbon Mobility Blueprint (LCMB). This study aims to quantify the health co-benefits of electric vehicle adoption from their impacts on air quality in Malaysia. Two EV uptake projections, i.e. LCMB and Revised EV Adoption (REVA) projections, and five electricity generation mix scenarios were modelled up to 2040. We used comparative health risk assessment to estimate the potential changes in mortality and burden of diseases (BoD) from the emissions in each scenario. Intake fractions and exposure-risk functions were used to calculate the burden from respiratory diseases (PM2.5, NOx, SO2, CO), cardiovascular diseases and lung cancer (PM2.5). Results showed that along with a net reduction of carbon emissions across all scenarios, there could be reduced respiratory mortality from NOx by 10,200 mortality (176,200 DALYs) and SO2 by 2600 mortality (45,400 DALYs) per year in 2040. However, there could also be additional 719 mortality (9900 DALYs) per year from PM2.5 and 329 mortality (5600 DALYs) from CO per year. The scale of reduction in mortality and BoD from NOx and SO2 are significantly larger than the scale of increase from PM2.5 and CO, indicating potential net positive health impacts from the EV adoption in the scenarios. The health cost savings from the reduced BoD of respiratory mortality could reach up to RM 7.5 billion per year in 2040. In conclusion, EV is a way forward in promoting a healthy and sustainable future transport in Malaysia.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Doenças Respiratórias , Humanos , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Emissões de Veículos/toxicidade , Emissões de Veículos/análise , Malásia , Poluição do Ar/análise , Material Particulado/toxicidade , Material Particulado/análise , Eletricidade , Doenças Respiratórias/induzido quimicamente , Doenças Respiratórias/epidemiologia
5.
Environ Monit Assess ; 195(10): 1218, 2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37718332

RESUMO

This study presents the kinetics and thermodynamics of biomass pyrolysis. The kinetics of the pyrolysis process was estimated using ten kinetic models from three different mechanisms, namely chemical reaction, diffusion, and nucleation and growth. Results showed that each pyrolysis subdivision was described by a different reaction model, signifying the complex nature of the pyrolysis process. The average values of activation energy determined from the kinetic models for empty fruit bunch, coconut shell, bamboo, and cardboard are 10.2-64.6 kJ/mol, 18.7-186.2 kJ/mol, 8.0-70.8 kJ/mol, and 13.1-277.3 kJ/mol, respectively. The biomass pyrolysis is endothermic and non-spontaneous and would require external energy to initiate the degradation process. The findings are helpful in characterizing the thermal degradation of biomass in exploring its potential as a source of alternative solid fuel.


Assuntos
Cocos , Frutas , Óleo de Palmeira , Cinética , Pirólise , Monitoramento Ambiental , Termodinâmica
6.
Environ Monit Assess ; 195(11): 1356, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37870632

RESUMO

This study evaluated the adsorptive properties of deep eutectic solvent (DES)-treated palm oil mill sludge adsorbents for methylene blue removal. The adsorbents were prepared at a ratio of 1:2 at 80°C to form P1:D2@80°C, at 25°C to form P1:D2@25°C and without DES to form dry sludge (DS). The adsorbent samples were characterized for surface functional groups, textural properties and surface morphology. The values of specific area were 534, 236 and 184 m2/g, respectively. Batch adsorption of methylene blue at varying concentration, adsorbent dosage, pH, contact time and temperature was performed. The maximum adsorption capacities by Sips model were recorded as 72.07, 56.18 and 48.33 mg/g for P1:D2@80°C, P1:D2@25°C and DS, respectively. P1:D2@80°C displayed the highest rate constant (Ks = 0.0037 g/mg.min). The adsorption data were well fitted into Sips isotherm and pseudo-second-order kinetic models, suggesting that the adsorption is a physical process onto heterogeneous adsorbent surface via pore filling and electrostatic attraction. The adsorption was spontaneous, feasible and exothermic with decreased disorderliness in the solid-bulk solution interface. The DES-treated palm oil mill sludge adsorbent is a promising alternative adsorbent for dye removal from wastewater.


Assuntos
Azul de Metileno , Esgotos , Óleo de Palmeira , Esgotos/química , Azul de Metileno/química , Solventes Eutéticos Profundos , Adsorção , Monitoramento Ambiental
7.
J Gene Med ; 23(12): e3381, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34312940

RESUMO

BACKGROUND: Long non-coding RNA ADAM metallopeptidase with thrombospondin type 1 motif, 9 antisense RNA 2 (ADAMTS9-AS2) was recognized as a novel tumor suppressor and plays an important role in the initiation and progression of malignant behavior in human cancers, although its plasma expression and clinical value in patients with non-small cell lung cancer (NSCLC) remain unknown. We aimed to analyze the diagnostic role of ADAMTS9-AS2 and cytokeratin 19 fragmentation antigen (CYFRA 21-1) in NSCLC. METHODS: The present study included 80 control subjects, 80 patients with benign lung lesion and 80 NSCLC patients. The expression of ADAMTS9-AS2 in the tissue and plasma was detected by a real-time polymerase chain reaction. Serum CYFRA 21-1 was analyzed using an enzyme-linked immunosorbent assay. RESULTS: In comparison with benign lung lesion and controls, tissue and plasma ADAMTS9-AS2 expression were significantly down-regulated in NSCLC (p < 0.001). Decreased ADAMTS9-AS2 expression was associated with TNM stages in NSCLC patients (p < 0.001). Up-regulation of CYFRA 21-1 was reported among NSCLC patients and it was associated with TNM staging. Tissue and plasma ADAMTS9-AS2 expression levels were the predicting factors for NSCLC and they both correlated negatively with CYFRA 21-1 levels. Plasma ADAMTS9-AS2 levels had a significant positive correlation with their tumor tissue levels. Plasma ADAMTS9-AS2 showed a higher sensitivity (95%) and specificity (99.1%) in the diagnosis of NSCLC than CYFRA 21-1 (61.3% sensitivity and 60% specificity). CONCLUSIONS: Our results suggested that decreased plasma ADAMTS9-AS2 expression might act as a novel non-invasive tumor biomarker in NSCLC diagnosis. Furthermore, plasma ADAMTS9-AS2 might predict aggressive tumor behavior.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , RNA Longo não Codificante , Antígenos de Neoplasias , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células/genética , Egito , Humanos , Queratina-19 , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , RNA Longo não Codificante/sangue , RNA Longo não Codificante/genética
8.
Clin Transplant ; 35(6): e14297, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33768630

RESUMO

INTRODUCTION: COVID-19 is an ongoing pandemic with high morbidity and mortality and with a reported high risk of severe disease in kidney transplant recipients (KTR). AIM: We aimed to report the largest number of COVID-19-positive cases in KTR in a single center and to discuss their demographics, management, and evolution. METHODS: We enrolled all the two thousand KTR followed up in our center in Kuwait and collected the data of all COVID-19-positive KTR (104) from the start of the outbreak till the end of July 2020 and have reported the clinical features, management details, and both patient and graft outcomes. RESULTS: Out of the one hundred and four cases reported, most of them were males aged 49.3 ± 14.7 years. Eighty-two of them needed hospitalization, of which thirty-one were managed in the intensive care unit (ICU). Main comorbidities among these patients were hypertension in 64.4%, diabetes in 51%, and ischemic heart disease in 20.2%. Management strategies included anticoagulation in 56.7%, withdrawal of antimetabolites in 54.8%, calcineurin inhibitor (CNI) withdrawal in 33.7%, the addition of antibiotics in 57.7%, Tocilizumab in 8.7%, and antivirals in 16.3%. During a follow-up of 30 days, the reported number of acute kidney injury (AKI) was 28.7%, respiratory failure requiring oxygen therapy 46.2%, and overall mortality rate was 10.6% with hospital mortality of 13.4% including an ICU mortality rate of 35.5%. CONCLUSION: Better outcome of COVID-19-positive KTR in our cohort during this unremitting stage could be due to the younger age of patients and early optimized management of anticoagulation, modification of immunosuppression, and prompt treatment of secondary bacterial infections. Mild cases can successfully be managed at home without any change in immunosuppression.


Assuntos
COVID-19 , Transplante de Rim , Anticoagulantes/uso terapêutico , Feminino , Humanos , Terapia de Imunossupressão , Transplante de Rim/efeitos adversos , Masculino , Estudos Retrospectivos , SARS-CoV-2 , Transplantados
9.
Nano Lett ; 18(5): 3172-3179, 2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29584948

RESUMO

Layered black phosphorus (BP) has attracted wide attention for mid-infrared photonics and high-speed electronics, due to its moderate band gap and high carrier mobility. However, its intrinsic band gap of around 0.33 electronvolt limits the operational wavelength range of BP photonic devices based on direct interband transitions to around 3.7 µm. In this work, we demonstrate that black arsenic phosphorus alloy (b-As xP1- x) formed by introducing arsenic into BP can significantly extend the operational wavelength range of photonic devices. The as-fabricated b-As0.83P0.17 photodetector sandwiched within hexagonal boron nitride (hBN) shows peak extrinsic responsivity of 190, 16, and 1.2 mA/W at 3.4, 5.0, and 7.7 µm at room temperature, respectively. Moreover, the intrinsic photoconductive effect dominates the photocurrent generation mechanism due to the preservation of pristine properties of b-As0.83P0.17 by complete hBN encapsulation, and these b-As0.83P0.17 photodetectors exhibit negligible transport hysteresis. The broad and large photoresponsivity within mid-infrared resulting from the intrinsic photoconduction, together with the excellent long-term air stability, makes b-As0.83P0.17 alloy a promising alternative material for mid-infrared applications, such as free-space communication, infrared imaging, and biomedical sensing.

10.
Bioorg Chem ; 74: 41-52, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28750204

RESUMO

A novel series of nitrogenous heterocycles starting from chalcones including thiazolo[3,2-a]pyrimidines (20-67), were synthesized. Structure elucidation of the synthesized compounds was attained by the use of 1H NMR, 13CC NMR, and Mass spectrometry. The obtained compounds were evaluated for their in vitro anticancer activity at the National Cancer Institute (NCI) 60 cell lines panel assay. Three cell lines, non-small cell lung cancer Hop-92, ovarian cancer IGROV1, and melanoma SK-MEL-2, exhibited some sensitivity against most of the tested compounds. Six compounds have passed the 5-log dose level NCI assay. Compounds 34 and 24 proved to be the most active derivatives with GI50, TGI, LC50 of 5.89, 20.0, 66.1% and 5.0, 19.5, 52.5% respectively. Compounds 36, 39, 63 showed lesser activity with GI50, TGI, LC50 3.2, 11.8, 38.9%, 3.4, 16.6, 60.3%, 3.5, 17.8, 66.1% respectively. DNA binding assay of synthesized compound were performed. Molecular docking showed that compounds 34, 42, and 60 could effectively fit into the minor groove and selectively bind with AT base pairs. The results could confer the anticancer activity of compounds 24, 34, 36, and 39in vitro to their abilities to bind at DNA minor groove.


Assuntos
Antineoplásicos/farmacologia , Pirimidinas/farmacologia , Tiazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Sítios de Ligação/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA de Neoplasias , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química
11.
Reprod Health ; 14(1): 108, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28854947

RESUMO

BACKGROUND: The existing literature is contradictory regarding effects of female genital mutilation/cutting (FGM/C) on sexual functions. The aim of this study was to explore the impact of type I and II FGM/C on sexual function of Egyptian women. METHODS: We recruited 197 cut women and 197 control women from those visiting Assiut University hospitals for different reasons. We asked each woman to fill the Arabic female sexual function index (FSFI) (a self reported 19-item questionnaire assessing the main domains of female sexual function). Genital Examination was done to confirm the type of FGM. RESULTS: Female sexual dysfunction (FSD) was found in 83.8% of FGM/C cases in contrast to 64.5% of the control. The total FSFI score in the FGM/C group (19.82 ± 7.1) was significantly lower than in the control group (23.34 ± 8.1). Concerning the types of FGM/C, type 73.6% of cases had type I and 26.4% had type II. Type I FGM/C was performed mainly by physicians (62.1%) while type II was performed mainly by midwives (44.4%). FSD was found in 83.4% of FGM/C I cases and in 84.6% of FGM/C II cases. There was no statistically significant difference between the two types of FGM/C as regards total and individual domain scores except for the pain domain. There were significantly lower total and individual domain scores in both FGM/C types except for the desire domain compared to control. CONCLUSION: In this study, FGM/C was associated with reduced scores of FSFI on all domains scores, and among both types I and II, both were associated with sexual dysfunction.


Assuntos
Circuncisão Feminina/efeitos adversos , Disfunções Sexuais Fisiológicas/epidemiologia , Estudos de Casos e Controles , Circuncisão Feminina/estatística & dados numéricos , Egito , Feminino , Humanos
12.
Water Sci Technol ; 75(3-4): 864-880, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28234287

RESUMO

This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m2/g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.


Assuntos
Carvão Vegetal/química , Cloretos/química , Rodaminas/análise , Ricinus communis/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Cátions , Difusão , Compostos Férricos/química , Cinética , Cloreto de Magnésio/química , Rodaminas/química , Sementes/química , Propriedades de Superfície , Temperatura , Termodinâmica , Poluentes Químicos da Água/química , Compostos de Zinco/química
13.
Water Sci Technol ; 76(7-8): 2232-2241, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29068353

RESUMO

The present work was aimed at evaluating the multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) ions onto natural bentonite. The bentonite clay adsorbent was characterized for physical and chemical properties using X-ray diffraction, X-ray fluorescence, Brunauer-Emmett-Teller surface area and cation exchange capacity. The column performance was evaluated using adsorbent bed height of 5.0 cm, with varying influent concentrations (10 mg/L and 50 mg/L) and flow rates (1.4 mL/min and 2.4 mL/min). The result shows that the breakthrough time for all metal ions ranged from 50 to 480 minutes. The maximum adsorption capacity was obtained at initial concentration of 10 mg/L and flow rate of 1.4 mL/min, with 2.22 mg/g of lead(II), 1.71 mg/g of cadmium(II) and 0.37 mg/g of manganese(II). The order of metal ions removal by natural bentonite is lead(II) > cadmium(II) > manganese(II). The sorption performance and the dynamic behaviour of the column were predicted using Adams-Bohart, Thomas, and Yoon-Nelson models. The linear regression analysis demonstrated that the Thomas and Yoon-Nelson models fitted well with the column adsorption data for all metal ions. The natural bentonite was effective for the treatment of wastewater laden with multi-metals, and the process parameters obtained from this work can be used at the industrial scale.


Assuntos
Bentonita/química , Cádmio/química , Chumbo/química , Manganês/química , Poluentes Químicos da Água/química , Adsorção , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água/métodos , Difração de Raios X
14.
J Am Chem Soc ; 138(47): 15488-15496, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27933922

RESUMO

Graphene nanoribbons (GNRs), quasi-one-dimensional graphene strips, have shown great potential for nanoscale electronics, optoelectronics, and photonics. Atomically precise GNRs can be "bottom-up" synthesized by surface-assisted assembly of molecular building blocks under ultra-high-vacuum conditions. However, large-scale and efficient synthesis of such GNRs at low cost remains a significant challenge. Here we report an efficient "bottom-up" chemical vapor deposition (CVD) process for inexpensive and high-throughput growth of structurally defined GNRs with varying structures under ambient-pressure conditions. The high quality of our CVD-grown GNRs is validated by a combination of different spectroscopic and microscopic characterizations. Facile, large-area transfer of GNRs onto insulating substrates and subsequent device fabrication demonstrate their promising potential as semiconducting materials, exhibiting high current on/off ratios up to 6000 in field-effect transistor devices. This value is 3 orders of magnitude higher than values reported so far for other thin-film transistors of structurally defined GNRs. Notably, on-surface mass spectrometry analyses of polymer precursors provide unprecedented evidence for the chemical structures of the resulting GNRs, especially the heteroatom doping and heterojunctions. These results pave the way toward the scalable and controllable growth of GNRs for future applications.

15.
J Am Chem Soc ; 137(13): 4453-9, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25823532

RESUMO

Recently, chemical synthesis of a range of large nanographene molecules with various shapes and sizes opened a new path to utilize them in various applications and devices. However, due to their extended aromatic cores and high molecular weight, film formation of large nanographene molecules, bearing more than 90 sp(2) carbon atoms in aromatic cores, is very challenging, which has prevented their applications such as in thin-film transistors. Here, we developed an effective approach to prepare films of such large nanographene molecules using a vapor-phase transport (VPT) technique based on molecule sublimation. The VPT of these molecules was made possible by combining the molecules and the target substrate in a small confinement of vacuum-sealed glass tube, so that a small amount of sublimation can be utilized to create films. Surprisingly, such heavy and large molecules can be deposited on any substrate by this method to create films of assembled large nanographene molecules while maintaining their aromatic cores intact, which was confirmed using mass spectrometry measurements. Moreover, field-effect transistors based on these films are depleted and show significantly improved current on/off ratio compared to previous large nanographene-based transistors fabricated using liquid-phase-based process. Our work shows that VPT deposition can be a viable technique to prepare films based on large nanographene molecules and potentially other high molecular weight compounds, which may find exciting applications in electronics and optoelectronics.

16.
J Am Chem Soc ; 136(21): 7555-8, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24831246

RESUMO

Bottom-up synthesis of graphene nanoribbons (GNRs) is an essential step toward utilizing them in electronic and sensing applications due to their defined edge structure and high uniformity. Recently, structurally perfect GNRs with variable lengths and edge structures were created using various chemical synthesis techniques. Nonetheless, issues like GNR deposition, characterization, electronic properties, and applications are not fully explored. Here we report optimized conditions for deposition, characterization, and device fabrication of individual and thin films of ultra-long chemically synthesized GNRs. Moreover, we have demonstrated exceptional NO2 gas sensitivity of the GNR film devices down to parts per billion (ppb) levels. The results lay the foundation for using chemically synthesized GNRs for future electronic and sensing applications.


Assuntos
Grafite/química , Nanotubos de Carbono/química , Substâncias Macromoleculares/química , Conformação Molecular , Propriedades de Superfície
17.
Oxf Med Case Reports ; 2024(8): omae088, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39161846

RESUMO

Foreign bodies are a rare cause of obstructive jaundice. In this case report, we present the case of a 59-year-old male who presented with abdominal pain and obstructive jaundice, which was later found out to be caused by an impacted shrapnel splinter in the common bile duct 7 years after a combat injury. To our knowledge, this is the first documented case from Syria. This case report is a reminder that impacted foreign bodies should be considered as a potential cause of obstructive jaundice in patients with previous combat injury.

18.
AMB Express ; 14(1): 43, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658456

RESUMO

A former work conducted in our Lab, lead to in a effective scale up of vitamin D3 bioconversion into calcitriol by Actinomyces (A.) hyovaginalis isolate CCASU-A11-2 in Lab fermenter (14 L) resulting in 32.8 µg/100 mL of calcitriol. However, the time needed for such a bioconversion process was up to 5 days. Therefore, the objective of this study was to shorten the bioconversion time by using cell-free lysate and studying different factors influencing bioconversion. The crude cell lysate was prepared, freeze-dried, and primarily fractionated into nine fractions, of which, only three fractions, 50, 100, and 150 mM NaCl elution buffers showed 22, 12, and 2 µg/10 mL, calcitriol production, respectively. Ammonium sulfate was used for protein precipitation, and it did not affect the bioconversion process except at a concentration of 10%w/v. Secondary fractionation was carried out using 80 mL of the 50 mM NaCl elution buffer and the results showed the 80 mL eluent volume was enough for the complete elution of the active protein. The pH 7.8, temperature 28 °C, and 6 h reaction time were optimum for maximum calcitriol production (31 µg/10 mL). In conclusion, the transformation of vitamin D3 into calcitriol was successfully carried out within 6 h and at pH 7.8 and 28 °C using fractionated cell lysate. This process resulted in a 10-fold increase in calcitriol as compared to that produced in our previous study using a 14 L fermenter (32.8 µg/100 mL). Therefore, cell-free lysate should be considered for industrial and scaling up vitamin D3 bioconversion into calcitriol.

19.
Int J Biol Macromol ; 277(Pt 4): 134353, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39089559

RESUMO

The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.


Assuntos
Celulose , Carvão Vegetal , Vermelho Congo , Azul de Metileno , Azul de Metileno/química , Celulose/química , Vermelho Congo/química , Adsorção , Carvão Vegetal/química , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Papel , Purificação da Água/métodos , Termodinâmica , Sais/química , Temperatura
20.
Eur J Gastroenterol Hepatol ; 35(11): 1298-1305, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37724477

RESUMO

AA amyloidosis is a rare and significant complication of long-term inflammation that can be caused by a variety of disorders, including inflammatory bowel disease, and is linked to an increased risk of morbidity and mortality. To date, there has been no effective direct treatment, and treatment aims at treating the underlying condition with potent immunosuppression to limit inflammatory activity and, as a result, switch off amyloidogenesis. Theoretically, biological treatment can control AA amyloidosis by inducing and maintaining inflammatory bowel disease remission and inhibiting the synthesis of Serum Amyloid A, which is an acute phase reactant and precursor protein of AA amyloidosis that accumulates in the organs. We report the first case of ustekinumab's therapeutic effect after infliximab's loss of response in AA amyloidosis associated with Crohn's disease. We also conducted a literature review of the therapeutic effect of biological treatment on AA amyloidosis.


Assuntos
Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Doença de Crohn/complicações , Doença de Crohn/diagnóstico , Doença de Crohn/tratamento farmacológico , Proteína Amiloide A Sérica , Inflamação
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