Thermal evolution process, properties and photocatalytic activity of sol-gel derived nanocrystalline anatase in dye degradation process

Nanocrystalline anatase aimed to be used as a photocatalyst for dye degradation processes in industrial effluents and has been prepared and investigated. Amorphous titania gel has been prepared using sol–gel process by slow hydrolysis of titanium n–butoxide. The prepared gel has been investigated using Fourier–Transformed Infra–Red Spectroscopy (FTIR), Powder X–ray Diffraction (PXRD), Differential Thermal Analysis (DTA), Thermo–Gravimetric Analysis (TGA), N2 gas adsorption–desorption isotherms and Diffuse Reflectance UV–Vis Spectroscopy (DRS). It was determined that the amorphous gel was comprised of non-hydrolyzed butoxy groups as well as hydroxyl groups bonded to titanium. The thermal evolution of gel is consisted of five steps: elimination of adsorbed water and butanol in temperature range between room temperature and 200 °C, decomposition and elimination of butoxy groups between 200 and 300°C. The crystallization of anatase centered at 404°C, transformation to rutile starting from 540 °C and oxidation of char and tar above 600°C. Thermal treatment of gel at 350 °C for 2 h yields with pure nanocrystalline anatase with average crystallite size of 13.2±0.2 nm, specific surface area of 65.48 m2 g–1 and bandgap, of 3.24 eV. The preliminary assessment of prepared catalyst photocatalytic activity was obtained through degradation process of methylene blue dye under UV light and the 99 % degradation of dye took place within 150 min

Multinuclear Magnetic Resonance Study on Aluminium Sec-butoxide Chelated with Ethyl Acetoacetate in Various Amounts

Reactive aluminum alkoxide (ASB, aluminium sec-butoxide) was chelated using β-diketone (EAA, ethyl acetoacetate) in order to gain control over rapid hydrolysis in the course of the sol-gel process. Derived chelates were analysed using several NMR spectroscopic techniques: one-dimensional 1H, 13C, 27Al NMR and two-dimensional COSY, HSQC and DOSY. The NMR analysis enabled identification of the formed chelate species, as well as determination of their quantitative relationships. Several complexation products were observed: tris-chelated monomer, Al(EAA)3, bis-chelated dimmer, Al2(OnBu)4(EAA) 2, tris-chelated dimmer, Al2(OnBu)3(EAA)3, tetra-chelated dimmer, Al2(OnBu)2(EAA)4, and monochelated trimer, Al3(OnBu)8(EAA). Of the formed oligomer compounds, this is the first evidence of Al2(OR)3L3 in any alkoxide and β-ketoester or β-diketone combination. Aluminium sec-butoxide and ethyl acetoacetate complexes Al2(OnBu)4(EAA) 2 and Al2(OnBu)2(EAA)4 were also observed for the first time. With the increase of the EAA/ASB ratio the coordination of aluminium shifts towards six, whereas above the EAA/ASB ratio of 2.5 solely six-coordinated aluminium exists. This work is licensed under a Creative Commons Attribution 4.0 International License

A Case of Primary Cardiac B-cell Lymphoma Diagnosed with Cardiac MRI

Primary cardiac tumors account for only 0.3% of all cardiac tumors; of these, lymphomas account for only 2% of all primary cardiac tumors. Cardiac lymphomas have a grim prognosis, often less than 1 year due to delays in diagnosis and treatment. Cardiac MRI is the gold standard for the imaging of cardiac tumors. We describe the case of a 76-year-old man with no significant past medical history who presented to the emergency department with a large pericardial effusion that was found to be consistent with cardiac lymphoma on cardiac MRI prior to tissue diagnosis of a primary cardiac diffuse large B-cell lymphoma. The clinical and radiological features of cardiac lymphoma are reviewed, and the therapeutic management and side-effects that the patient experienced are discussed

The preparation of nanocrystalline anatase from modified alkoxide

Keliranjem titanijeva n-butoksida, Ti(OnBu)4, s etil-acetoacetatom, C6H10O3 u različitim molarnim omjerima pripravljena je serija solova. Solovi su potom izloženi utjecaju atmosferske vlage kako bi se sporom hidrolizom transformirali u gelove. Gelovi su termički obrađeni pri različitim temperaturama s ciljem dobivanja čistog nanokristaličnog anatasa. Uzorci solova, gelova te toplinski obrađeni uzorci potom su istraživani metodama 1H, 13C i HSQC NMR, FTIR spektroskopije, UV-Vis i DRS spektroskopije, XRD analize, DTA/TGA, FE-SEM, HR-TEM i N2 adsorpcijsko/desorpcijskim izotermama kako bi se proučio utjecaj dodanog EAA na novonastale vrste i njihove kvantitativne odnose, strukturu i svojstva gelova i toplinski obrađenih uzoraka te tijek same kristalizacije. Utvrđeno je da nastaju tri kelatne vrste i to bis-kelirani monomer, Ti(OnBu)2(EAA)2, bis-kelirani dimer, (Ti(OnBu)3EAA)2 i monokelirani dimer, Ti2(OnBu)7EAA. Porastom udjela kelirajućeg agensa mijenja se dominantna molekula kompleksa, od monokeliranog i bis-keliranog dimera do bis-keliranog monomera. Zapaženo je i da dolazi do reakcije transesterifikacije, što utječe na sastav spojeva. Također je utvrđeno da su modificirani alkoksidi djelomično hidrolizirani te sadrže različite količine butoksi i etil-acetoacetatnih grupa vezanih na titanij. Rendgenskom difrakcijskom analizom uzoraka gela uočeno je postojanje uređenosti na nivou mezostrukture popraćeno karakterističnim širokim maksimumom pri nižim kutovima 2θ, što je nadalje potvrđeno HR-TEM mikroskopijom. Nastala mezostruktura izgrađena je od anorganskoorganskih nanoklastera različite veličine i sastava. Utvrđen je tijek procesa do kojih dolazi termičkom obradom gelova. Toplinskom obradom uzoraka gela pri temperaturi od 350 °C u trajanju 2 h dobiven je čist nanokristaličan anatas. Relativno mala specifična površina anatasa posljedica je smanjenja volumena mezopora zbog prisutnosti zaostale organske faze u porama. Fotokatalitička učinkovitost pripravljenog anatasa je ispitana pri razgradnji organskog bojila metilensko plavilo. Zapaženo je da svi uzorci imaju vrlo dobra fotokatalitička svojstva. Na temelju dobivenih rezultata raspravljeno je o učinku modifikacije titanijeva n-butoksida s etil acetoacetatom na pojavu molekulskih vrsta u solu, strukturu gelova i toplinski obrađenih uzoraka te tijek kristalizacije i svojstva anatasa. Čist, nanokristaličan, fotokatalitički aktivan anatas pripravljen je jednostavnim i ekonomičnim postupkom.Series of sols have been prepared by chelation of titanium n-butoxide, Ti(OnBu)4, with ethyl acetoacetate, C6H10O3, in various ratios. Sols were subsequently transformed to gels by slow hydrolysis after exposition to air moisture. The gels were thermally treated at various temperatures in order to obtain pure nanocrystalline anatase. Sols, gels and thermally treated samples were investigated by means of 1H, 13C i HSQC NMR, FTIR, UV-Vis spectroscopy, DRS, XRD, DTA/TGA, FE-SEM, HR-TEM, N2 adsorption/desorption isotherms in order to provide insight in compounds obtained, their quantitative relationships, structure and properties of gels and thermally treated samples as well as crystallization path. Three compounds, bis-chelated monomer, Ti(OnBu)2(EAA)2, bis-chelated dimer, (Ti(OnBu)3EAA)2 and monochelated dimer, Ti2(OnBu)7EAA have been established. As the molar ratio EAA/Ti(OnBu)4 increases, the dominant complex molecule changes from the monochelated and bis-chelated dimer to bis-chelated monomer. Additionally, the transesterification reaction, influencing the chemical composition of the compounds has been noted. It was also determined that modified alkoxides are partially hydrolyzed having different amounts of butoxide and ethyl acetoacetate groups attached to titanium. XRD pattern of gels exhibited broad, low-angle reflection, which indicates the existence of some degree of ordering on the mesostructure scale. HR-TEM of the gels also revealed the presence of mesostructure. Observed mesostructure was found to consist of inorganic-organic nanoclusters, exhibiting some polydispersity in the size and variations in composition. Thermal evolution processes path of gels have been established. After thermal treatment of the gels at 350 °C for 2 h, pure nanocrystalline anatase was obtained. Relatively low specific surface area of anatase was ascribed to the reduction of mesopores volume due to blockage with carbonaceous material. The photocatalytic efficiency of the prepared nanocrystalline anatase has been tested on the degradation of synthetic organic dye methylene blue. It has been noted that all samples possess very good photocatalytic properties. From the results obtained, the effect of modification of titanium n-butoxide with ethyl acetoacetate on molecular species in sol, on gel structure and crystallization behavior and properties of anatase crystallized thereof was discussed. Pure, nanocrystalline, photocatalytically active anatase has been prepared through simple and affordable procedure

The preparation of nanocrystalline anatase from modified alkoxide

Keliranjem titanijeva n-butoksida, Ti(OnBu)4, s etil-acetoacetatom, C6H10O3 u različitim molarnim omjerima pripravljena je serija solova. Solovi su potom izloženi utjecaju atmosferske vlage kako bi se sporom hidrolizom transformirali u gelove. Gelovi su termički obrađeni pri različitim temperaturama s ciljem dobivanja čistog nanokristaličnog anatasa. Uzorci solova, gelova te toplinski obrađeni uzorci potom su istraživani metodama 1H, 13C i HSQC NMR, FTIR spektroskopije, UV-Vis i DRS spektroskopije, XRD analize, DTA/TGA, FE-SEM, HR-TEM i N2 adsorpcijsko/desorpcijskim izotermama kako bi se proučio utjecaj dodanog EAA na novonastale vrste i njihove kvantitativne odnose, strukturu i svojstva gelova i toplinski obrađenih uzoraka te tijek same kristalizacije. Utvrđeno je da nastaju tri kelatne vrste i to bis-kelirani monomer, Ti(OnBu)2(EAA)2, bis-kelirani dimer, (Ti(OnBu)3EAA)2 i monokelirani dimer, Ti2(OnBu)7EAA. Porastom udjela kelirajućeg agensa mijenja se dominantna molekula kompleksa, od monokeliranog i bis-keliranog dimera do bis-keliranog monomera. Zapaženo je i da dolazi do reakcije transesterifikacije, što utječe na sastav spojeva. Također je utvrđeno da su modificirani alkoksidi djelomično hidrolizirani te sadrže različite količine butoksi i etil-acetoacetatnih grupa vezanih na titanij. Rendgenskom difrakcijskom analizom uzoraka gela uočeno je postojanje uređenosti na nivou mezostrukture popraćeno karakterističnim širokim maksimumom pri nižim kutovima 2θ, što je nadalje potvrđeno HR-TEM mikroskopijom. Nastala mezostruktura izgrađena je od anorganskoorganskih nanoklastera različite veličine i sastava. Utvrđen je tijek procesa do kojih dolazi termičkom obradom gelova. Toplinskom obradom uzoraka gela pri temperaturi od 350 °C u trajanju 2 h dobiven je čist nanokristaličan anatas. Relativno mala specifična površina anatasa posljedica je smanjenja volumena mezopora zbog prisutnosti zaostale organske faze u porama. Fotokatalitička učinkovitost pripravljenog anatasa je ispitana pri razgradnji organskog bojila metilensko plavilo. Zapaženo je da svi uzorci imaju vrlo dobra fotokatalitička svojstva. Na temelju dobivenih rezultata raspravljeno je o učinku modifikacije titanijeva n-butoksida s etil acetoacetatom na pojavu molekulskih vrsta u solu, strukturu gelova i toplinski obrađenih uzoraka te tijek kristalizacije i svojstva anatasa. Čist, nanokristaličan, fotokatalitički aktivan anatas pripravljen je jednostavnim i ekonomičnim postupkom.Series of sols have been prepared by chelation of titanium n-butoxide, Ti(OnBu)4, with ethyl acetoacetate, C6H10O3, in various ratios. Sols were subsequently transformed to gels by slow hydrolysis after exposition to air moisture. The gels were thermally treated at various temperatures in order to obtain pure nanocrystalline anatase. Sols, gels and thermally treated samples were investigated by means of 1H, 13C i HSQC NMR, FTIR, UV-Vis spectroscopy, DRS, XRD, DTA/TGA, FE-SEM, HR-TEM, N2 adsorption/desorption isotherms in order to provide insight in compounds obtained, their quantitative relationships, structure and properties of gels and thermally treated samples as well as crystallization path. Three compounds, bis-chelated monomer, Ti(OnBu)2(EAA)2, bis-chelated dimer, (Ti(OnBu)3EAA)2 and monochelated dimer, Ti2(OnBu)7EAA have been established. As the molar ratio EAA/Ti(OnBu)4 increases, the dominant complex molecule changes from the monochelated and bis-chelated dimer to bis-chelated monomer. Additionally, the transesterification reaction, influencing the chemical composition of the compounds has been noted. It was also determined that modified alkoxides are partially hydrolyzed having different amounts of butoxide and ethyl acetoacetate groups attached to titanium. XRD pattern of gels exhibited broad, low-angle reflection, which indicates the existence of some degree of ordering on the mesostructure scale. HR-TEM of the gels also revealed the presence of mesostructure. Observed mesostructure was found to consist of inorganic-organic nanoclusters, exhibiting some polydispersity in the size and variations in composition. Thermal evolution processes path of gels have been established. After thermal treatment of the gels at 350 °C for 2 h, pure nanocrystalline anatase was obtained. Relatively low specific surface area of anatase was ascribed to the reduction of mesopores volume due to blockage with carbonaceous material. The photocatalytic efficiency of the prepared nanocrystalline anatase has been tested on the degradation of synthetic organic dye methylene blue. It has been noted that all samples possess very good photocatalytic properties. From the results obtained, the effect of modification of titanium n-butoxide with ethyl acetoacetate on molecular species in sol, on gel structure and crystallization behavior and properties of anatase crystallized thereof was discussed. Pure, nanocrystalline, photocatalytically active anatase has been prepared through simple and affordable procedure

High Surface Area Ceria Nanoparticles via Hydrothermal Synthesis Experiment Design

Hydrothermal synthesis of CeO2 was optimized on two reactant concentrations and synthesis temperature and duration, in order to achieve material having the greatest specific surface area (SSA). Taguchi method of experimental design was employed in evaluation of the relative importance of synthesis parameters. CeO2 nanoparticles were characterized using X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. Optimum conditions for obtaining particles with greater SSA were calculated according to Taguchi’s model “the-higher-the-better.” Synthesis temperature was found to be the only parameter significant for enabling nanoparticles with greater SSA. Mesoporous nanocrystalline ceria with SSA as great as 226 m2 g−1 was achieved, which is unprecedented for the hydrothermally synthesized ceria. The reason for this achievement was found in temperature dependence of the diffusion coefficient which, when low, favors nucleation yielding with fine particles, while when high it favors crystal growth and formation of one-dimensional structures. The occurrence of 1D-structure in sample exhibiting the smallest SSA was confirmed. Very fine crystallites with crystallite size as low as 5.9 nm have been obtained being roughly inverse proportional to SSA. Selected samples were tested as catalyst for soot oxidation. Catalyst morphology turned out to be decisive factor for catalytic activity

Hydrothermally-Derived Silver-Decorated Nanocrystalline Anatase Photocatalyst for Reactive Violet 2 Photodegradation

A photocatalyst comprised of Ag nanoparticles dispersed on an anatase matrix has been prepared using a simple hydrothermal method without additional thermal treatment. The prepared material was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV-Vis spectroscopy, and N2 adsorption–desorption isotherms. The prepared catalyst activity was evaluated by photocatalytic degradation of C.I. Reactive Violet 2 (RV2) aqueous solution under UVA and visible light illumination. SEM revealed the non-uniform dispersion of silver particles throughout the matrix composed of fine particles. According to XRD analysis, the matrix was composed of pure anatase with a crystallite size of 8 nm calculated through the Scherrer equation. HRTEM micrograph analysis showed that anatase nanoparticles possess a spherical morphology and a narrow size distribution with an average particle size of 8 nm with more active anatase {100} crystal surface exposed, while silver nanoparticles were between 60 and 90 nm. A bandgap of 3.26 eV has been calculated on the basis of the DRS UV-Vis spectrum, while a specific surface area of 209 m2g−1 has been established from adsorption isotherms. Thus, through a simple synthesis approach without subsequent thermal treatment, the agglomeration of nanoparticles and the reduction of specific surface area have been avoided. Prepared nano Ag/anatase photocatalyst exhibits excellent efficiency for the photodegradation of RV2 under UVA and visible irradiation

Prognostic Value of Venous Thromboembolism Risk Assessment Models in Patients with Severe COVID-19

Introduction Severe novel corona virus disease 2019 (COVID-19) causes dysregulation of the coagulation system with arterial and venous thromboembolism (VTE). We hypothesize that validated VTE risk scores would have prognostic ability in this population. Methods Retrospective observational cohort with severe COVID-19 performed in NorthShore University Health System. Patients were >18 years of age and met criteria for inpatient or intensive care unit (ICU) care. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) and Caprini scores were calculated and patients were stratified. Results This study includes 184 patients, mostly men (63.6%), Caucasian (54.3%), 63 years old (interquartile range [IQR]: 24–101), and 57.1% of them required ICU care. Twenty-seven (14.7%) thrombotic events occurred: 12 (6.5%) cases of disseminated intravascular coagulation (DIC), 9 (4.9%) of pulmonary embolism, 5 (2.7%) of deep vein thrombosis, and 1 (0.5%) stroke. Among them, 86 patients (46.7%) died, 95 (51.6%) were discharged, and 3 (1.6%) were still hospitalized. “Moderate risk for VTE” and “High risk for VTE” by IMPROVE score had significant mortality association: (hazard ratio [HR]: 5.68; 95% confidence interval [CI]: 2.93–11.03; p < 0.001) and (HR = 6.22; 95% CI: 3.04–12.71; p < 0.001), respectively, with 87% sensitivity and 63% specificity (area under the curve [AUC] = 0.752, p < 0.001). “High Risk for VTE” by Caprini score had significant mortality association (HR = 17.6; 95% CI: 5.56–55.96; p < 0.001) with 96% sensitivity and 55% specificity (AUC = 0.843, p < 0.001). Both scores were associated with thrombotic events when classified as “High risk for VTE” by IMPROVE (HR = 6.50; 95% CI: 2.72–15.53; p < 0.001) and Caprini scores (HR = 11.507; 95% CI: 2.697–49.104; p = 0.001). Conclusion The IMPROVE and Caprini risk scores were independent predictors of mortality and thrombotic events in severe COVID-19. With larger validation, this can be useful prognostic information