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1.
RSC Adv ; 14(23): 16560-16573, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38779388

RESUMEN

A cheap, versatile, sustainable and energy-efficient gel-combustion method was applied to develop a series of green-emitting down-converted Y2Si2O7:Tb3+ (YPS:Tb3+) nanophosphors. Employing XRD-based Rietveld refinement approach, the phase purity and crystallographic evaluation of the produced phosphor were conducted, revealing a triclinic crystal with P1̄ space group. EDX and TEM analyses were performed on the synthesized samples to determine their elemental composition and morphological properties. Diffuse reflectance spectra yielded 5.61 eV and 5.79 eV optical energy band gaps for the host and the optimized (0.04 mole of Tb3+) sample, respectively. UV light has the ability to excite the nanocrystalline phosphor in an efficient manner, leading to significant luminosity qualities attributed to the radiative relaxation of 5D4 → 7FJ (J = 6, 5, 4, 3). The bi-exponential decay function was derived by the PL decay curves. With an activation energy of 0.2206 eV, the Y1.96Si2O7:0.04Tb3+ phosphor exhibits good thermal quenching capabilities. Improved photometric attributes including CIE coordinates, CCT and color purity confirmed the green glow, indicating a strong competitor for cool-green emission in lighting applications.

2.
Bioorg Chem ; 147: 107363, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38657527

RESUMEN

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.


Asunto(s)
Antioxidantes , Dipeptidil Peptidasa 4 , Hipoglucemiantes , Pirazoles , Triazoles , alfa-Amilasas , Pirazoles/química , Pirazoles/farmacología , Pirazoles/síntesis química , Antioxidantes/farmacología , Antioxidantes/química , Antioxidantes/síntesis química , Triazoles/química , Triazoles/farmacología , Triazoles/síntesis química , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipoglucemiantes/síntesis química , Relación Estructura-Actividad , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo , Dipeptidil Peptidasa 4/metabolismo , Estructura Molecular , Humanos , Relación Dosis-Respuesta a Droga , Inhibidores de la Dipeptidil-Peptidasa IV/química , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Inhibidores de la Dipeptidil-Peptidasa IV/síntesis química , Simulación del Acoplamiento Molecular , Picratos/antagonistas & inhibidores , Compuestos de Espiro/química , Compuestos de Espiro/farmacología , Compuestos de Espiro/síntesis química , Oxindoles/farmacología , Oxindoles/química , Oxindoles/síntesis química , Benzopiranos , Nitrilos
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 315: 124307, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38653075

RESUMEN

Europium complexes exhibiting red luminescence were prepared by employing ß-diketone as main ligand and 1,10-phenanthroline as an additional ligand. Various methods, including 1H NMR, IR spectroscopy and analysis of optical band gap were employed to examine these complexes. The luminescent photophysical properties were investigated using PL spectroscopy and theoretical calculations were conducted to explore radiative transitions probabilities and Judd-Ofelt (J-O) parameters for transitions of type 5D0 → 7F2, 4. J-O parameters were determined using the JOES computer program and results were in good agreement with the outcomes obtained experimentally. The luminescence analysis results have verified the vibrant, single-color red emission of the prepared complexes. The band gap of ternary europium complexes, determined optically, electronically, and theoretically, falls within the range of 3-4 eV. This similarity indicates that these complexes are potentially suitable as semiconductor materials. The results from absorption, electrochemical and photophysical analyses indicate the potential use of synthesized complexes in lighting and display applications.

4.
RSC Adv ; 14(14): 9406-9439, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38516158

RESUMEN

Supercapacitors are the latest development in the field of energy storage devices (ESDs). A lot of research has been done in the last few decades to increase the performance of supercapacitors. The electrodes of supercapacitors are modified by composite materials based on conducting polymers, metal oxide nanoparticles, metal-organic frameworks, covalent organic frameworks, MXenes, chalcogenides, carbon nanotubes (CNTs), etc. In comparison to rechargeable batteries, supercapacitors have advantages such as quick charging and high power density. This review is focused on the progress in the development of electrode materials for supercapacitors using composite materials based on conducting polymers, graphene, metal oxide nanoparticles/nanofibres, and CNTs. Moreover, we investigated different types of ESDs as well as their electrochemical energy storage mechanisms and kinetic aspects. We have also discussed the classification of different types of SCs; advantages and drawbacks of SCs and other ESDs; and the use of nanofibres, carbon, CNTs, graphene, metal oxide-nanofibres, and conducting polymers as electrode materials for SCs. Furthermore, modifications in the development of different types of SCs such as pseudo-capacitors, hybrid capacitors, and electrical double-layer capacitors are discussed in detail; both electrolyte-based and electrolyte-free supercapacitors are taken into consideration. This review will help in designing and fabricating high-performance supercapacitors with high energy density and power output, which will act as an alternative to Li-ion batteries in the future.

5.
RSC Adv ; 14(2): 755-770, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38174268

RESUMEN

The present study reveals the structural and optoelectronic characteristics of a down-converted (DC) green luminous Er3+ doped LaSr2AlO5 phosphor that was produced by employing an efficient and reliable gel-combustion process assisted with urea as a fuel. Using Rietveld refinement of diffraction data, the crystal structure and phase formation were examined. The surface morphology and elemental configuration of the phosphor were analyzed via TEM and EDX spectroscopy, respectively. The band gap of LaSr2AlO5 (5.97 eV) and optimized La0.96Sr2AlO5:4 mol% Er3+ (5.51 eV) classify the optimized sample as a direct band-gap material. The PL peaks located in the visible range corresponding to transitions 2H9/2 → 4I15/2 (406 nm), 2H11/2 → 4I15/2 (520 nm), 4S3/2 → 4I15/2 (550 nm), and 4F9/ 2 → 4I15/2 (665 nm) were revealed by photoluminescence spectroscopy under 377 nm excitation. Above 4 mol% Er3+ doping, concentration quenching was observed, which was controlled by the quadrupole-quadrupole interaction. Based on the findings of the double exponential fitting of lifetime curves acquired from the emission spectra at λex = 377 nm and λem = 550 nm, the average lifetime of the excited levels of considered nanomaterials was estimated. The temperature-dependent emission spectra of the La0.96Sr2AlO5:4 mol% Er3+ sample were collected in the range 298-498 K. The considered phosphor was found to have a high thermal stability as evidenced by the luminous intensity being sustained at 74.29% at 498 K compared to the intensity at ambient temperature (298 K) with an activation energy of 0.1453 eV. The calculated color purity and superb chromaticity coordinates indicates that the phosphors have a high degree of color purity, which further supports its applicability as a green component in solid-state lighting.

7.
Future Med Chem ; 15(16): 1511-1525, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37610859

RESUMEN

Aim: To enrich the pool of α-amylase inhibitors to manage Type 2 diabetes. Methods: Synthesis, conformational study, α-amylase inhibitory action and various in silico studies of novel N'-(arylbenzylidene)-2-(4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d]imidazol-1-yl)acetohydrazides carried out. Results: Compound H6 demonstrated the highest activity (IC50 = 0.0437 µmol mL-1) among the tested compounds. Structure-activity relationship study suggested that variable substitution at the aryl ring has a pivotal role in determining the inhibitory action of tested compounds. Docking simulations of the most active compound (H6) confirmed its interaction potential with active site residues of A. oryzae α-amylase. The root-mean-square deviation fluctuations substantiated the stability of protein-ligand complex. Absorption, distribution, metabolism and excretion prediction revealed optimal values for absorption, distribution, metabolism and excretion parameters. Conclusion: The developed molecules could be beneficial for the development of novel α-amylase inhibitors to treat Type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hidrazonas , Humanos , Hidrazonas/farmacología , alfa-Amilasas , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Imidazoles/farmacología , Imidazoles/química , Relación Estructura-Actividad
8.
Future Med Chem ; 15(14): 1273-1294, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37551699

RESUMEN

Aim: The primary objective of this investigation was the synthesis, spectral interpretation and evaluation of the α-amylase inhibition of rationally designed thiazolidinedione-triazole conjugates (7a-7aa). Materials & methods: The designed compounds were synthesized by stirring a mixture of thiazolidine-2,4-dione, propargyl bromide, cinnamaldehyde and azide derivatives in polyethylene glycol-400. The α-amylase inhibitory activity of the synthesized conjugates was examined by integrating in vitro and in silico studies. Results: The investigated derivatives exhibited promising α-amylase inhibitory activity, with IC50 values ranging between 0.028 and 0.088 µmol ml-1. Various computational approaches were employed to get detailed information about the inhibition mechanism. Conclusion: The thiazolidinedione-triazole conjugate 7p, with IC50 = 0.028 µmol ml-1, was identified as the best hit for inhibiting α-amylase.

9.
Angew Chem Int Ed Engl ; 62(41): e202308813, 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37594782

RESUMEN

One route to address climate change is converting carbon dioxide to synthetic carbon-neutral fuels. Whereas carbon dioxide to CO conversion has precedent in homo- and heterogeneous catalysis, deoxygenative coupling of CO to products with C-C bonds-as in liquid fuels-remains challenging. Here, we report coupling of two CO molecules by a diiron complex. Reduction of Fe2 (CO)2 L (2), where L2- is a bis(ß-diketiminate) cyclophane, gives [K(THF)5 ][Fe2 (CO)2 L] (3), which undergoes silylation to Fe2 (CO)(COSiMe3 )L (4). Subsequent C-OSiMe3 bond cleavage and C=C bond formation occurs upon reduction of 4, yielding Fe2 (µ-CCO)L. CO derived ligands in this series mediate weak exchange interactions with the ketenylidene affording the smallest J value, with changes to local metal ion spin states and coupling schemes (ferro- vs. antiferromagnetism) based on DFT calculations, Mössbauer and EPR spectroscopy. Finally, reaction of 5 with KEt3 BH or methanol releases the C2 O2- ligand with retention of the diiron core.

10.
Global Spine J ; : 21925682231188363, 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-37411005

RESUMEN

OBJECTIVE: To report clinical characteristics and course of care for patients diagnosed with hematogenous spinal osteomyelitis (HVO). METHODS: Medical records of patients presenting to two tertiary care centers with HVO were reviewed. RESULTS: 96 consecutive patients with HVO were identified. Mean follow-up was 8.9 months. Most infections occurred in the lumbar region (50.0%). Of the cultures taken, MRSA accounted for 9%; MSSA, 26%; Streptococcus species, 12%; other gram-positive bacteria, 23%; gram-negative, 17%; fungal, 2.6%; and 11.5% of cultures returned no growth. 57 patients underwent surgery. Of these, 79% of the patients had undergone a trial of empiric antibiotics (cefepime and vancomycin) of the day prior to surgery. 44% underwent secondary surgeries, typically due to a heavy wound burden of necrotic tissue and pus. Postoperative antibiotics were prescribed to all patients. 51.6% of the patients were prescribed antibiotic therapy >6 months. Overall mortality rate was 3.8%. Major cause of all deaths was septic shock. Post-infection sequelae occurred in 47.4% of patients. The most common sequelae were persistent or new sites of infection, sepsis, and abscess. CONCLUSIONS: Diabetes, hypertension, and renal failure appear to increase the risk of post-infection sequelae and death. While non-operative management was attempted in nearly 47%, ultimately 73% had surgery. This high rate may reflect our population of patients hospitalized in a tertiary care center. Available data suggests that patients presenting with hematogenous osteomyelitis be followed closely as failure of non-operative management, and resulting morbidity, was high.

11.
Luminescence ; 38(10): 1789-1802, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37495554

RESUMEN

Yellowish-white light-emitting Gd2-x Si2 O7 :xDy3+ (x = 1-5 mol%) nanophosphors were prepared using a solution combustion synthesis method. Fluorescence spectrophotometry and X-ray diffraction measurements were performed to scrutinize the optical performances and phase recognition of the designated nanophosphors. The outcomes specified that the prepared phosphors were crystallized into a triclinic phase with a P-1 space group. As the concentration of Dy3+ ions was increased, the unit-cell volume decrease proportionally due to the replacement of large-sized Gd3+ by small-sized Dy3+ ions. Under ultraviolet excitation at 349 nm, emission spectra consisted of two pronounced emission lines at ~482 nm (blue line), ~578 nm (yellow line), and a relatively weaker emission at ~670 nm (red line) due to 4 F9/2 →6 H15/2 , 4 F9/2 →6 H13/2 , and 4 F9/2 →6 H11/2 intraconfigurational transitions of Dy3+ ions, respectively. The evidence about the site symmetry around Dy3+ ions was examined by considering the ratio of yellow-to-blue emission intensity. The observed critical distance (Rc ) value was ~20.56 Å (≫5 Å), which signified that energy transfer primarily occurred due to multipolar interaction. The obtained coordinates were close to the white region of the Commission Internationale de l'Éclairage chromaticity diagram, which marked a significant milestone in the development of white light-emitting diodes.

12.
J Clin Med ; 12(14)2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37510691

RESUMEN

Unlike other adverse drug reactions, visceral organ involvement is a prominent feature of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and correlates with mortality. The aim of this study was to systematically review cases published in PubMed-indexed, peer-reviewed journals in which patients had renal injury during the episode of DRESS syndrome (DS). We found 71 cases, of which 67 were adults and 56% were males. Female sex was associated with higher mortality. Chronic kidney disease (CKD) was present in 14% of patients who developed acute kidney injury (AKI) during DS. In 21% of cases, the kidneys were the only visceral organ involved, while 54% of patients had both liver and kidney involvement. Eosinophilia was absent in 24% of patients. The most common classes of medication associated with renal injury in DS were antibiotics in 34%, xanthine oxidase inhibitors in 15%, and anticonvulsants in 11%. Among antibiotics, vancomycin was the most common culprit in 68% of patients. AKI was the most common renal manifestation reported in 96% of cases, while isolated proteinuria or hematuria was present in only 4% of cases. In cases with AKI, 88% had isolated increase in creatinine and decrease in glomerular filtration (GFR), 27% had AKI concomitantly with proteinuria, 18% had oliguria, and 13% had concomitant AKI with hematuria. Anuria was the rarest manifestation, occurring in only 4% of patients with DS. Temporary renal replacement therapy was needed in 30% of cases, and all but one patient fully recovered renal function. Mortality of DS in this cohort was 13%, which is higher than previously reported. Medication class, latency period, or pre-existing CKD were not found to be associated with higher mortality. More research, particularly prospective studies, is needed to better recognize the risks associated with renal injury in patients with DS. The development of disease-specific biomarkers would also be useful so DS with renal involvement can be easier distinguished from other eosinophilic diseases that might affect the kidney.

13.
JBJS Rev ; 11(4)2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-37071742

RESUMEN

¼: Minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) are both metrics at interpreting patient-reported outcome measures (PROMs). ¼: MCID values tend to vary significantly depending on the baseline pain and function in both acute and chronic symptom states while PASS thresholds are more stable. ¼: MCID values are more easily attainable than PASS thresholds. ¼: Although PASS is more relevant to the patient, it should continue to be used in tandem with MCID when interpreting PROM data.


Asunto(s)
Procedimientos Ortopédicos , Ortopedia , Humanos , Resultado del Tratamiento , Diferencia Mínima Clínicamente Importante
14.
RSC Adv ; 13(13): 9033-9045, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36950083

RESUMEN

A series of lanthanide complexes have been synthesized with fluorinated 1,3-diketones and heteroaromatic ancillary moieties. Spectroscopic studies reveal the attachment of the respective lanthanide ion to the oxygen site of ß-diketone and nitrogen site of auxiliary moieties. The conducting behavior of the complexes is proposed by their optical energy gaps which lie in the range of semiconductors. The emission profiles of the lanthanide complexes demonstrate red and green luminescence owing to the distinctive transitions of Sm3+ and Tb3+ ions, respectively. Energy transfer via antenna effect clearly reveals the effective transfer of energy from the chromophoric moiety to the Ln3+ ion. The prepared conducting and luminescent Ln(iii) complexes might be employed as the emitting component in designing OLEDs.

15.
Comput Biol Med ; 157: 106776, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36947906

RESUMEN

α-Amylase (EC.3.2.1.1) is a ubiquitous digestive endoamylase. The abrupt rise in blood glucose levels due to the hydrolysis of carbohydrates by α-amylase at a faster rate is one of the main reasons for type 2 diabetes. The inhibitors prevent the action of digestive enzymes, slowing the digestion of carbs and eventually assisting in the management of postprandial hyperglycemia. In the course of developing α-amylase inhibitors, we have screened 2-aryliminothiazolidin-4-one based analogs for their in vitro α-amylase inhibitory potential and employed various in silico approaches for the detailed exploration of the bioactivity. The DNSA bioassay revealed that compounds 5c, 5e, 5h, 5j, 5m, 5o and 5t were more potent than the reference drug (IC60 value = 22.94 ± 0.24 µg mL-1). The derivative 5o with -NO2 group at both the rings was the most potent analog with an IC60 value of 19.67 ± 0.20 µg mL-1 whereas derivative 5a with unsubstituted aromatic rings showed poor inhibitory potential with an IC60 value of 33.40 ± 0.15 µg mL-1. The reliable QSAR models were developed using the QSARINS software. The high value of R2ext = 0.9632 for model IM-9 showed that the built model can be applied to predict the α-amylase inhibitory activity of the untested molecules. A consensus modelling approach was also employed to test the reliability and robustness of the developed QSAR models. Molecular docking and molecular dynamics were employed to validate the bioassay results by studying the conformational changes and interaction mechanisms. A step further, these compounds also exhibited good ADMET characteristics and bioavailability when tested for in silico pharmacokinetics prediction parameters.


Asunto(s)
Diabetes Mellitus Tipo 2 , Simulación de Dinámica Molecular , Humanos , Simulación del Acoplamiento Molecular , Relación Estructura-Actividad Cuantitativa , Colorimetría , Reproducibilidad de los Resultados , alfa-Amilasas
16.
RSC Adv ; 13(11): 7703-7718, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36908532

RESUMEN

A material's luminosity characteristics, which in turn dictate its applicability, are critically influenced by its structure. Therefore, it is essential for design and fabrication of optical nanocrystalline materials to comprehend the relationship between structural and luminescence properties. The gel-combustion approach was used to produce a sequence of orange-red light emanating GdSr2AlO5:Sm3+ (GSA:Sm3+) nanophosphors which are used for warm white-light-emitting diodes (w-LEDs). Comprehensive investigation of the structural and optical characteristics of GdSr2AlO5:Sm3+ nanophosphors has been done in a detailed manner. The synthesized powdered nanophosphors are crystallized in a tetragonal phase with I4/mcm (140) space group, affirmed through Rietveld refining method. The nano size with an aggregated, spherical form of the particles in the powdered nanocrystalline material was revealed by TEM analysis. These orange-red emitting phosphors Gd1-x Sr2AlO5:xSm3+ (x = 1-7 mol%) were shown to possess photoluminosity (PL) properties that demonstrated the presence of most intense emission peaks at 603 nm that were caused by 4G5/2 → 6H7/2 transitions of the Sm3+ ion under 273 nm excitation. Considering its long decay lifespan and PL emission, it can be concluded that the GdSr2AlO5:Sm3+ phosphor is a potential single element for the fabrication of warm white light-emitting devices.

17.
RSC Adv ; 13(12): 7752-7765, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36909772

RESUMEN

Cool green light emanating monoclinic Y4-x Al2O9:xTb3+ (x = 1-5 mol%) nanophosphors have been fabricated through gel-combustion method. X-ray diffraction and transmission electron-microscopy data have been utilized to assess their structural and microstructural characteristics, including cell parameters and crystallite size. Uneven aggregation of nanoparticles in the nano-scale with distinctive porosity can be seen in the TEM micrograph. Kubelka-Munk model imitative diffuse reflectance spectra and an optical band gap of 5.67 eV for the Y3.97Al2O9:0.03Tb3+ nanophosphor revealed high optical quality in the samples, which were thought to be non-conducting. The emission (PL) and excitation (PLE) spectra as well as lifetime measurements have been used to determine the luminescence characteristics of the synthesized nanophosphors. The emission spectra show two color i.e. blue color due to 5D3 → 7F J (J = 4 and 5) transitions and green color due to 5D4 → 7F J (J = 3, 4, 5 and 6) transitions. The most dominant transition (5D4 → 7F5) at 548 nm was responsible for the greenish color in focused nanocrystalline samples. Calculated colorimetric characteristics such as CIE, and CCT along with color purity of the synthesized nanocrystalline materials make them the best candidate for the solid-state lighting (SSL).

18.
Luminescence ; 38(5): 585-599, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36929247

RESUMEN

Terbium(III)-doped yttrium aluminate perovskite (YAP:xTb3+ ) (x = 0.01-0.08 mol) was synthesized using a simple gel-combustion method. Structural elucidations were performed using X-ray diffraction (XRD) and Rietveld analysis. Fourier-transform infrared spectral studies validated the efficient synthesis of designed doped samples. Transmission electron microscopic images showed the agglomerated irregular dimensions of the synthesized nanocrystalline materials. When excited at 251 nm, a strong emissive line attributed to 5 D4 → 7 F5 electronic transition was observed at 545 nm (green emission). The maximum luminescence was found at the optimized concentration (0.05 mol) of Tb3+ ions; this emission was quenched by dipolar-dipolar (d-d) interactions. Chromaticity (x and y) and correlated colour temperature parameters were obtained by analysing the emission profiles. Finally, the colour coordinates of nanophosphors were closer to the National Television Standards Committee green coordinates, which replicates their potency in the design and architecture of R-G-B-based white LEDs.


Asunto(s)
Iluminación , Óxidos , Óxidos/química , Terbio/química , Luminiscencia , Difracción de Rayos X
19.
Luminescence ; 38(1): 56-63, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36511827

RESUMEN

A series of heteroleptic terbium(III) complexes with fluorinated 2-thenoyltrifluoroacetone (TTFA) and other heteroaromatic units have been synthesized. The developed heteroleptic complexes were inspected via elemental study, cyclic voltammetry, thermal analysis and spectroscopic investigations. Optical band-gap data proposed the conducting property of prepared complexes. The photoluminescence emission profiles illustrated peaks based on terbium(III) cation (Tb3+ ) positioned at ~617, 586, 546 and 491 nm, imputed to 5 D4 to 7 FJ (J = 3,4,5,6) transitions separately. Most intense peak at 546 nm corresponding to 5 D4 → 7 F5 transition is accountable for the green emissive character of developed complexes. The luminous character of complexes reveals the sensitization of Tb3+ by ligands. Color parameters further corroborates the green emanation of Tb3+ complexes. The photometric characteristics of complexes recommended their usages in designing display devices.

20.
Global Spine J ; 13(1): 197-208, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35410499

RESUMEN

STUDY DESIGN: Systematic review and Meta-analysis. OBJECTIVE: This systematic review seeks to compare fusion, reoperation and complication rates, estimated blood loss (EBL), and surgical time between multi-level instrumented fusions with LIVs (lowest instrumented vertebra) in the cervical spine and those that extend into the thoracic spine. SUMMARY OF BACKGROUND DATA: Several studies address the question of whether to extend a long-segment, posterior cervical fusions, performed for degenerative disease, into the upper thoracic spine. Recommendations for appropriate LIV continue to vary. METHODS: A comprehensive computerized literature search through multiple electronic databases without date limits up until April 3rd, 2020 using combinations of key search terms and sets of inclusion/exclusion criteria was performed. RESULTS: Our comprehensive literature search yielded 3852 studies. Of these, 8 articles consisting of 1162 patients were included in the meta-analysis. In 61.2% of the patients, the fusion did not cross the cervicothoracic junction (CTJ) (cervical LIV, CLV). In the remaining 38.8%, the fusion extended into the upper thoracic spine (thoracic LIV, TLV). Overall, mean patient age was 62.5 years (range: 58.8-66.1 years). Our direct analysis showed that odds of fusion were not statistically different between the CLV and TLV groups (OR: .648, 95% CI: .336-1.252, P = .197). Similarly, odds of reoperation (OR: 0.726, 95% CI: 0.493-1.068, P = .104) and complication rates were similar between the 2 groups (OR: 1.214, 95% CI: 0.0.750-1.965, P = .430). Standardized mean difference (SMD) for the blood loss (SMD: .728, 95% CI: 0.554-.901, P = .000) and operative (SMD: 0.653, 95% CI: .479-.826, P = .000) differed significantly between the 2 groups. The indirect analysis showed similar fusion (Effect Size (ES)TLV: .892, 95% CI: .840-.928 vs ESCLV:0.894, 95% CI:0.849-.926); reoperation rate (ESTLV:0.112, 95% CI: 0.075-.164 vs ESCLV: .125, 95% CI: .071-.211) and complication rates (ESTLV: .108, 95% CI: .074-.154 vs ESCLV:0.081, 95% CI: .040-.156). CONCLUSIONS: Our meta-analysis showed that fusion, complication, and reoperation rates did not differ significantly between patients in whom multi-level posterior fusions ended in the cervical spine vs those of which was extended into the thoracic spine. The mean blood loss, operative time and length of stay were significantly lower in patients with CLV at C6 or C7, compared to their counterparts. These data suggest that, absent focal, C7-T1 pathology, extension of long, posterior cervical fusions into the thoracic spine may not be necessary.

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