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1.
Inorg Chem ; 63(24): 11279-11295, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38822820

RESUMO

A new array of ternary lanthanide complexes of the form [Ln(hfa)3(tpy-HImzphen)] have been synthesized and thoroughly characterized wherein Ln = LaIII (1), EuIII (2), SmIII (3), and TbIII (4); hfa = hexafluoroacetylacetonate; and tpy-HImzphen = 2-(4-[2,2':6',2″]terpyridin-4'-yl-phenyl)-1H-phenanthro[9,10-d]imidazole. Incorporation of tpy-HImzphen onto the Ln-hfa moiety induced a bathochromic shift of the absorption window of the complexes into the visible region. Extensive investigations of the luminescence characteristics have been conducted both at RT and at 77 K to understand the deactivation pathways of the complexes. Both steady-state and time-resolved emission spectral behaviors indicate four distinctive behaviors upon incorporation of tpy-HImzphen onto the lanthanide core, viz., a huge red-shift of the ligand-centered peak for LaIII; almost complete energy transfer for EuIII; very little energy transfer for SmIII, while reverse energy transfer in the case of TbIII. In addition, the EuIII-complex exhibits its excellence in luminescence thermometry in the solution state as well as in poly(methyl methacrylate) (PMMA) thin films. The thermosensitive luminescence response in solution was further utilized to mimic set-reset flip-flop logic operation. A plausible energy transfer scheme has been devised to explain dissimilar luminescence behaviors in the complexes. The role of LMCT was also considered for the observed thermosensing property of the Eu(III) complex.

2.
J Pept Sci ; 30(2): e3538, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37609959

RESUMO

Morpholine, which scores 7.5 in terms of greenness and is not a regulated substance, could be considered a strong contender for Fmoc removal in solid-phase peptide synthesis (SPPS). Morpholine in dimethylformamide (DMF) (50%-60%) efficiently removes Fmoc in SPPS, minimizes the formation of diketopiperazine, and almost avoids the aspartimide formation. As a proof of concept, somatostatin has been synthesized using 50% morpholine in DMF with the same purity as when using 20% piperidine-DMF.


Assuntos
Fluorenos , Técnicas de Síntese em Fase Sólida , Fluorenos/química , Morfolinas
3.
J Theor Biol ; 572: 111589, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37532028

RESUMO

The renin-angiotensin systems play pivotal role in cardiovascular physiology through its effects on regulating blood pressure and electrolyte homeostasis. Components of circulating RAS (cRAS) that include precursor angiotensinogen, two critical enzymes (renin and angiotensin-converting enzyme, ACE), their bioactive products, angiotensin- I, II together with its receptors (AT1R and AT2R) essentially determine this homeostasis. Most classical studies, however, showed the deleterious role of cRAS in elevating the blood pressure. Contemporary discovery of non-canonical components of the RAS has challenged this classic hypothesis that it can only exert deleterious effects on the cardiovascular systems. Using the classic cRAS model, we have designed in-silico experiments to test the hypothesis that AT2R-mediated feedback effects play pivotal role for maintaining the normal variation of the mean-arterial pressure (MAP).Beside the AT2R-mediation of downstream singling pathways consisting of several non-canonical RAS components, this study first time illustrated AT2R mediated feedback controls over the blood pressure regulation: one that impedes AT1R activity, and the other that downregulates renin. It has been shown that relatively stronger suppression of renin activity significantly contributes in maintaining the normal MAP and that tight AT2R-mediated regulation is relaxed in hyper-and hypotension. This control mechanism is noted to be robustly maintained with the MAP variations through an established linear steady-state relationship among renin, angiotensin I and angiotensin II. This examination suggests that AT2R-mediated downregulation of renin activities potentially counteracts the AT1R-mediated deleterious actions of Ang II. This study, therefore, provides a solid ground for considering different AT2 receptor adaptor protein and direct agonism at AT2R that can cause greater effects along with contemporary approaches of blocking AT1R mediation to attenuate hypertension or other cardiovascular disorders.


Assuntos
Pressão Arterial , Renina , Renina/metabolismo , Retroalimentação , Sistema Renina-Angiotensina/fisiologia , Angiotensina II/metabolismo
4.
Skeletal Radiol ; 52(3): 315-328, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35804163

RESUMO

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.


Assuntos
Neoplasias Ósseas , Fluordesoxiglucose F18 , Criança , Humanos , Pré-Escolar , Compostos Radiofarmacêuticos , Neoplasias Ósseas/patologia , Tomografia por Emissão de Pósitrons/métodos , Imageamento por Ressonância Magnética/métodos , Radiologistas , Espectroscopia de Ressonância Magnética , Estadiamento de Neoplasias
5.
J Environ Manage ; 331: 117264, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36634422

RESUMO

Empirical evidence supporting the associations between malaria incidence and climatic factors has remained controversial, buffering the progress in the Global Malaria Program that aims to eliminate 90% of the world malaria burden by 2030. This study has aimed to evaluate the nature and extent at which these relations are maintained across all the malaria endemic countries of Africa and Asia-Pacific region. We have utilized the last two decades of malaria incidence, annual minimum temperature, and annual precipitation time series data (2000-2020) for the two most malaria-impacted regions. These data were fitted in the generalized linear model and the mixed effects model. The results showed that there exists a large heterogeneity in malaria incidence across the countries, and between the regions. Last two decadal tendencies showed significant reductions in the disease burden in almost all the countries in the Asia Pacific, with several exceptions or relatively slowed reductions in the Africa. We found significant changes in the positive linear associations between malaria incidence, annual minimum temperature, and annual precipitation across African countries. Many Asia-Pacific countries namely Bangladesh, Bhutan, Indonesia, South Korea, Nepal, Thailand, Vietnam showed negative effects in the associations with the annual precipitation. This study indicates that increasing temperature within the range of 12-30 °C can generate positive effects on malaria incidence, but the nature and extent of precipitation effects vary across countries and at a large regional scale.


Assuntos
Malária , Humanos , Incidência , Malária/epidemiologia , Indonésia , Tailândia , África/epidemiologia
6.
J Org Chem ; 87(1): 708-712, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34910477

RESUMO

Chemoselective disulfide formation is accomplished through a thiol-disulfide interchange approach using sec-isoamyl mercaptan (SIT) as an alkyl sulfenyl-protecting group of one of the Cys residues involved in the pairing. SIT has a dual and unique characteristic, acting as a masking group during the synthesis and directing disulfide formation in the presence of a free thiol. This novel approach is illustrated by the synthesis of several peptides of biological interest.


Assuntos
Dissulfetos , Compostos de Sulfidrila , Peptídeos
7.
Skeletal Radiol ; 51(11): 2217-2221, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35301556

RESUMO

The use of computer-navigated, robotic-assisted total knee arthroplasty (TKA) is expanding as the result of widespread efforts to improve the precision of implant placement and to restore mechanical, anatomic, and kinematic alignment. The procedure requires placement of femoral and tibial pins to mount the robotic tracking system. Fractures through tracking pin sites following robotic-assisted TKA are rare; only 30 cases have been reported to our knowledge. It is probable that this complication will become more frequent as the use of robotic-assisted TKAs continues to grow. We report the case of a 67-year-old female who suffered a fracture of the femur through two pin sites 3 months after a robotic-assisted TKA. We believe that this report is the first case in the radiologic literature. Our case demonstrates some of the difficulties of recognizing this complication and raises questions about appropriate post-operative imaging.


Assuntos
Artroplastia do Joelho , Fraturas do Fêmur , Procedimentos Cirúrgicos Robóticos , Cirurgia Assistida por Computador , Idoso , Artroplastia do Joelho/métodos , Pinos Ortopédicos/efeitos adversos , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Humanos , Articulação do Joelho/cirurgia , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Cirurgia Assistida por Computador/métodos
8.
Molecules ; 27(3)2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35164065

RESUMO

The entry of the SARS-CoV-2, a causative agent of COVID-19, into human host cells is mediated by the SARS-CoV-2 spike (S) glycoprotein, which critically depends on the formation of complexes involving the spike protein receptor-binding domain (RBD) and the human cellular membrane receptor angiotensin-converting enzyme 2 (hACE2). Using classical site density functional theory (SDFT) and structural bioinformatics methods, we investigate binding and conformational properties of these complexes and study the overlooked role of water-mediated interactions. Analysis of the three-dimensional reference interaction site model (3DRISM) of SDFT indicates that water mediated interactions in the form of additional water bridges strongly increases the binding between SARS-CoV-2 spike protein and hACE2 compared to SARS-CoV-1-hACE2 complex. By analyzing structures of SARS-CoV-2 and SARS-CoV-1, we find that the homotrimer SARS-CoV-2 S receptor-binding domain (RBD) has expanded in size, indicating large conformational change relative to SARS-CoV-1 S protein. Protomer with the up-conformational form of RBD, which binds with hACE2, exhibits stronger intermolecular interactions at the RBD-ACE2 interface, with differential distributions and the inclusion of specific H-bonds in the CoV-2 complex. Further interface analysis has shown that interfacial water promotes and stabilizes the formation of CoV-2/hACE2 complex. This interaction causes a significant structural rigidification of the spike protein, favoring proteolytic processing of the S protein for the fusion of the viral and cellular membrane. Moreover, conformational dynamics simulations of RBD motions in SARS-CoV-2 and SARS-CoV-1 point to the role in modification of the RBD dynamics and their impact on infectivity.


Assuntos
Enzima de Conversão de Angiotensina 2/ultraestrutura , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/ultraestrutura , Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , COVID-19/fisiopatologia , Biologia Computacional/métodos , Teoria da Densidade Funcional , Humanos , Modelos Teóricos , Ligação Proteica , Domínios Proteicos , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/fisiologia , Relação Estrutura-Atividade
9.
Biophys J ; 118(4): 898-908, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-31699333

RESUMO

Defective nitrate signaling in plants causes disorder in nitrogen metabolism, and it negatively affects nitrate transport systems, which toggle between high- and low-affinity modes in variable soil nitrate conditions. Recent discovery of a plasma membrane nitrate transceptor protein NRT1.1-a transporter cum sensor-provides a clue on this toggling mechanism. However, the general mechanistic description still remains poorly understood. Here, we illustrate adaptive responses and regulation of NRT1.1-mediated nitrate signaling in a wide range of extracellular nitrate concentrations. The results show that the homodimeric structure of NRT1.1 and its dimeric switch play an important role in eliciting specific cytosolic calcium waves sensed by the calcineurin-B-like calcium sensor CBL9, which activates the kinase CIPK23, in low nitrate concentration that is, however, impeded in high nitrate concentration. Nitrate binding at the high-affinity unit initiates NRT1.1 dimer decoupling and priming of the Thr101 site for phosphorylation by CIPK23. This phosphorylation stabilizes the NRT1.1 monomeric state, acting as a high-affinity nitrate transceptor. However, nitrate binding in both monomers, retaining the unmodified NRT1.1 state through dimerization, attenuates CIPK23 activity and thereby maintains the low-affinity mode of nitrate signaling and transport. This phosphorylation-led modulation of NRT1.1 activity shows bistable behavior controlled by an incoherent feedforward loop, which integrates nitrate-induced positive and negative regulatory effects on CIPK23. These results, therefore, advance our molecular understanding of adaptation in fluctuating nutrient availability and are a way forward for improving plant nitrogen use efficiency.


Assuntos
Arabidopsis , Nitratos , Proteínas de Transporte de Ânions , Arabidopsis/metabolismo , Transportadores de Nitrato , Nitratos/metabolismo , Proteínas de Plantas/metabolismo
10.
J Magn Reson Imaging ; 51(3): 768-779, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31313397

RESUMO

BACKGROUND: Super-resolution is an emerging method for enhancing MRI resolution; however, its impact on image quality is still unknown. PURPOSE: To evaluate MRI super-resolution using quantitative and qualitative metrics of cartilage morphometry, osteophyte detection, and global image blurring. STUDY TYPE: Retrospective. POPULATION: In all, 176 MRI studies of subjects at varying stages of osteoarthritis. FIELD STRENGTH/SEQUENCE: Original-resolution 3D double-echo steady-state (DESS) and DESS with 3× thicker slices retrospectively enhanced using super-resolution and tricubic interpolation (TCI) at 3T. ASSESSMENT: A quantitative comparison of femoral cartilage morphometry was performed for the original-resolution DESS, the super-resolution, and the TCI scans in 17 subjects. A reader study by three musculoskeletal radiologists assessed cartilage image quality, overall image sharpness, and osteophytes incidence in all three sets of scans. A referenceless blurring metric evaluated blurring in all three image dimensions for the three sets of scans. STATISTICAL TESTS: Mann-Whitney U-tests compared Dice coefficients (DC) of segmentation accuracy for the DESS, super-resolution, and TCI images, along with the image quality readings and blurring metrics. Sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence intervals compared osteophyte detection for the super-resolution and TCI images, with the original-resolution as a reference. RESULTS: DC for the original-resolution (90.2 ± 1.7%) and super-resolution (89.6 ± 2.0%) were significantly higher (P < 0.001) than TCI (86.3 ± 5.6%). Segmentation overlap of super-resolution with the original-resolution (DC = 97.6 ± 0.7%) was significantly higher (P < 0.0001) than TCI overlap (DC = 95.0 ± 1.1%). Cartilage image quality for sharpness and contrast levels, and the through-plane quantitative blur factor for super-resolution images, was significantly (P < 0.001) better than TCI. Super-resolution osteophyte detection sensitivity of 80% (76-82%), specificity of 93% (92-94%), and DOR of 32 (22-46) was significantly higher (P < 0.001) than TCI sensitivity of 73% (69-76%), specificity of 90% (89-91%), and DOR of 17 (13-22). DATA CONCLUSION: Super-resolution appears to consistently outperform naïve interpolation and may improve image quality without biasing quantitative biomarkers. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:768-779.


Assuntos
Aprendizado Profundo , Osteoartrite , Biomarcadores , Humanos , Imageamento por Ressonância Magnética , Osteoartrite/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos
11.
Inorg Chem ; 58(16): 10725-10735, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31368683

RESUMO

Four new dinuclear complexes, [Co(µ-L)(µ-CCl3COO)Y(NO3)2]·2CHCl3·CH3CN·2H2O (1), [Co(µ-L)(µ-CH3COO)Y(NO3)2]·CH3CN (2), [Co(µ-L)(µ-PhCOO)Y(NO3)2]·3CH3CN·2H2O (3), and [Co(µ-L)(µ-tBuCOO)Y(NO3)2]·CHCl3·2H2O (4), having a CoIIYIII core, have been synthesized by employing a ferrocene based compartmental ligand which was synthesized by the reaction of diacetyl ferrocene with hydrazine hydrate followed by a condensation reaction with o-vanillin. A general synthetic protocol was employed to synthesize complexes 1-4, where the metallic core was kept the same with changing the bridging carboxylate groups. In all the complexes, the main structural motif is kept similar by only slightly varying the substitution on the bridging acetate groups. This variation has resulted in a small but subtle influence on the magnetic relaxation of all these four compounds. Ab initio CASSCF/NEVPT2 calculations were carried out to assess the effect of the different substitutions of the bridging ligands on the magnetic anisotropy parameters and on orbital arrangements. Ab initio calculations yield a very large positive D value, which is consistent with the geometry around the CoII ion and easy plane anisotropy (gxx, gyy > gzz), with the order of the calculated D in the range of 72.4 to 91.7 cm-1 being estimated in this set of complexes. To ascertain the sign of zero-field splitting in these complexes, EPR spectra were recorded, which support the sign of D values estimated from ab initio calculations.

12.
Chembiochem ; 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29897151

RESUMO

Nonalcoholic fatty liver disease (NAFLD), which is characterized by excess accumulation of triglyceride in hepatocytes, is the major cause of chronic liver disease worldwide and no approved drug is available. The mechanistic target of rapamycin (mTOR) complexes has been implicated in promoting lipogenesis and fat accumulation in the liver, and thus, serve as attractive drug targets. The generation of non- or low cytotoxic mTOR inhibitors is required because existing cytotoxic mTOR inhibitors are not useful for NAFLD therapy. New compounds based on the privileged adenosine triphosphate (ATP) site binder quinoline scaffold conjugated to glucose and galactosamine derivatives, which have significantly low cytotoxicity, but strong mTORC1 inhibitory activity at low micromolar concentrations, have been synthesized. These compounds also effectively inhibit the rate of lipogenesis and lipid accumulation in cultured hepatocytes. This is the first report of glycomimetic-quinoline derivatives that reduce lipid load in hepatocytes.

13.
J Phys Chem A ; 122(35): 7089-7098, 2018 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-30101586

RESUMO

Sulfonated polyaniline (SPANI) has emerged as a promising polymer in the past few decades due to its solubility in water and relatively moderate conductivity. However, to date, literature data on the optical characterization of SPANI are very limited and preliminary in nature. In the present work, SPANI is synthesized by direct sulfonation of emeraldine salt form of polyaniline with chlorosulfonic acid in an inert solvent. Detail photophysical properties of SPANI are investigated in aqueous medium by using steady state (concentration, temperature, pH, and excitation wavelength dependence) and time-resolved spectroscopic techniques. The steady state fluorescence emission measurements are carried out carefully to avoid inner filter effect (especially secondary inner filter effect or reabsorption effect) as well as scattering. Two ground state conformations of SPANI are suggested to exist in aqueous medium. Excitation wavelength dependence of the fluorescence emission spectra is attributed to red-edge effect. All these observations are nicely corroborated by the fluorescence lifetime data of SPANI obtained from time-resolved measurements. All these new findings are extremely important in view of the potential applications of SPANI in polymer optoelectronics.

14.
Pediatr Radiol ; 48(11): 1642-1654, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29971479

RESUMO

BACKGROUND: Localized craniofacial scleroderma is a rare pediatric disease that involves a spectrum of discoloration, fibrosis and hemiatrophy of the face and scalp. Children with localized craniofacial scleroderma may have neurological symptoms, and in this context often undergo diagnostic imaging of the brain. OBJECTIVE: To catalogue neuroimaging abnormalities in patients with localized craniofacial scleroderma treated at our institution, review their clinical courses and compare this data with prior studies. MATERIALS AND METHODS: Following Institutional Review Board approval, an imaging database search identified 10 patients with localized craniofacial scleroderma and neuroimaging abnormalities treated at our institution. Neuroimaging exams and the electronic medical record were reviewed for each case. RESULTS: The most common indications for neuroimaging were headache or seizure (80% of cases). The most common neuroimaging abnormalities were T2-hyperintense, subcortical white matter lesions ipsilateral to the cutaneous lesion (90% of cases) on magnetic resonance imaging (MRI). Calcifications or blood products (50%), cysts (40%) and abnormal enhancement (20%) were also observed. A positron emission tomography (PET) scan obtained for a single case demonstrated diminished 18F-fluorodeoxyglucose (FDG) avidity corresponding to the dominant focus of signal abnormality on MRI. Progressive neuroimaging abnormalities were present in 30% of cases. There was no consistent relationship between changes in neurological symptoms following treatment and neuroimaging findings. CONCLUSION: Our results are similar to previously published data. In the absence of new or worsening neurological symptoms, the role of neuroimaging for follow-up of localized craniofacial scleroderma is unclear. Knowledge of intracranial neuroimaging abnormalities that are commonly associated with localized craniofacial scleroderma helps to distinguish these lesions from others that have similar appearance.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico por imagem , Hemiatrofia Facial/diagnóstico por imagem , Neuroimagem/métodos , Esclerodermia Localizada/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
15.
Angew Chem Int Ed Engl ; 57(20): 5797-5802, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29573097

RESUMO

A rapid and scalable synthesis of six new imine-linked highly porous and crystalline COFs is presented that feature exceptionally high chemical stability in harsh environments including conc. H2 SO4 (18 m), conc. HCl (12 m), and NaOH (9 m). This is because of the presence of strong interlayer C-H⋅⋅⋅N hydrogen bonding among the individual layers, which provides significant steric hindrance and a hydrophobic environment around the imine (-C=N-) bonds, thus preventing their hydrolysis in such an abrasive environment. These COFs were further converted into porous, crystalline, self-standing, and crack-free COF membranes (COFMs) with extremely high chemical stability for their potential applications for sulfuric acid recovery. The as-synthesized COFMs exhibit unprecedented permeance for acetonitrile (280 Lm-2 h-1 bar-1 ) and acetone (260 Lm-2 h-1 bar-1 ).

16.
Clin Nephrol ; 88(11): 239-247, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29017699

RESUMO

INTRODUCTION: It is well documented that patients with osteoporosis (OP) have high incidence of hypercalciuria (HC). However, the mechanism of HC in patients with OP is not well established. It is thought to be the result of high bone turnover (HBT) with excessive bone resorption. OP also frequently presents with low bone turnover (LBT). At this time, it is not clear whether OP with LBT is also associated with hypercalciuria. PURPOSE: The purpose of this study is to evaluate urinary calcium excretion in osteoporotic patients with HBT and LBT. MATERIALS AND METHODS: This is a retrospective study of 132 patients with osteoporosis who underwent bone biopsy at the University of Kentucky between January 2010 and December 2012. Based on bone biopsy results, patients were divided into HBT or LBT groups. Demographic data, medical history, bone mineral density, serum creatinine, calcium, phosphorus, estimated glomerular filtration rate (eGFR), filtered calcium load, fractional excretion of calcium and phosphorus, 25-hydroxy vitamin D levels, and 24-hour urinary calcium excretion and creatinine were obtained from the patients' medical records. Also, intact parathyroid hormone (iPTH), serum osteocalcin, bone-specific alkaline phosphatase, N-telopeptide of type I collagen, and urine pyridinium levels were measured. RESULTS: Hypercalciuria was present in approximately half of the patients in both the HBT and LBT groups. Patients with HBT OP were significantly younger than those with LBT OP (p = 0.013). There was no difference between HBT and LBT patients in 24-hour urinary calcium excretion, serum creatinine, calcium, phosphorus, eGFR, filtered calcium load, and fractional excretion of phosphorus. Mean values of serum osteocalcin and serum N-telopeptide of type I collagen were significantly lower in the LBT compared to the HBT group (p = 0.000 and 0.0152, respectively). There was a significant correlation between filtered calcium load and urinary calcium excretion in HBT patients but not in patients with LBT. Fractional excretion of calcium significantly correlated with urinary calcium excretion in both groups. There was no correlation between kidney function and 24-hour urinary calcium excretion. There was no correlation between dual-emission X-ray absorptiometry T-scores and 24-hour urinary calcium excretion. CONCLUSION: HC is frequently present in patients with OP regardless of the underlying bone turnover status. This may suggest the presence of a bone-derived renal calcium regulating factor(s). Further studies are needed to understand the exact mechanism and the potential consequences of HC in OP patients.
.


Assuntos
Remodelação Óssea , Cálcio/urina , Osteoporose/metabolismo , Adulto , Idoso , Densidade Óssea , Colágeno Tipo I/sangue , Creatinina/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteocalcina/sangue , Peptídeos/sangue , Estudos Retrospectivos
17.
Inorg Chem ; 53(13): 6524-33, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24902495

RESUMO

The reaction of Ln(III) nitrate and Mn(ClO4)2·6H2O salts in the presence of a multidentate sterically unencumbered ligand, (E)-2,2'-(2-hydroxy-3-((2-hydroxyphenylimino)methyl)-5-methylbenzylazanediyl)diethanol (LH4) leads to the isolation of four isostructural pentanuclear hetereometallic complexes [Mn(III)2Gd3(LH)4(NO3)(HOCH3)]ClO4·NO3 (1), [Mn(III)2Dy3(LH)4(NO3)(HOCH3)]ClO4·NO3 (2), [Mn(III)2Tb3(LH)4(NO3)(HOCH3)]ClO4·NO3 (3), and [Mn(III)2Ho3(LH)4(NO3)(HOCH3)]ClO4·NO3 (4) with an open-book type structural topology. 1-4 are dicationic and crystallize in the achiral space group, P21/n. A total of four triply deprotonated ligands, [LH](3-), are involved in holding the pentameric metal framework, {Mn(III)2Ln3}. In these complexes both the lanthanide and the manganese(III) ions are doubly bridged, involving phenolate or ethoxide oxygen atoms. The magnetochemical analysis reveals the presence of global antiferromagnetic interactions among the spin centers at low temperatures in all the four compounds. AC susceptibility measurements show the presence of temperature dependent out-of-phase ac signal for compounds 2 and 4 indicating an SMM behavior.

18.
Math Biosci ; 368: 109132, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38128645

RESUMO

Engaging in smoking not only leads to substantial health risks but also imposes considerable financial burdens. To deepen our understanding of the mechanisms behind smoking transmission and to address the tobacco epidemic, we examined a five-dimensional smoking epidemic model that accounts for different degrees of smoking under both deterministic and stochastic conditions. In the deterministic case, we determine the basic reproduction number, analyze the stability of equilibria with and without smoking, and investigate the existence of saddle-node bifurcation. Our analysis reveals that the basic reproduction number cannot completely determine the existence of smoking, and the model possesses bistability, indicating its dynamic is susceptible to interference from environmental noises. In the stochastic case, we establish sufficient conditions for the ergodic stationary distribution and the elimination of smokers by constructing appropriate Lyapunov functions. Numerical simulations suggest that the effects of inevitable random fluctuations in the natural environment on controlling the smoking epidemic may be beneficial, harmful, or negligible, which are closely related to the noise intensities, initial smoking population sizes, and the effective exposure rate of smoking transmission (ß). Given the uncontrollable nature of environmental random effects, effective smoking control strategies can be achieved by: (1) accurate monitoring of initial smoking population sizes, and (2) implementing effective measures to reduce ß. Therefore, it is both effective and feasible to implement a complete set of strong MPOWER measures to control smoking prevalence.


Assuntos
Epidemias , Simulação por Computador , Processos Estocásticos , Número Básico de Reprodução , Fumar/epidemiologia
19.
Dalton Trans ; 53(7): 3065-3074, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38235760

RESUMO

The thermosensing and thermochromic behavior of one of our recently reported terpyridyl-imidazole based ternary europium tris-(ß-diketonate) complexes of the composition [Eu(tta)3(tpy-HImzphen)] (tta = 2-thenoyltrifluoroacetone and tpy-HImzphen = 2-(4-[2,2':6',2''] terpyridin-4'-yl-phenyl)-1H-phenanthro[9,10-d]imidazole) has been thoroughly investigated in this work. The said Eu(III) complex exhibits magnificent thermosensing as well as thermochromic properties and can be recommended as an excellent temperature sensor in a wide temperature domain of 273-343 K in terms of both emission intensity ratio (Sm = 5.78% K-1 at Tm = 343 K, δT = 0.012 K) and lifetime values (Sm = 3.36% K-1 at Tm = 333 K, δT = 0.009 K) or even in terms of its emitting color (red at 268 K, violet at 303 K, and blue at 343 K). Additionally, it displays remarkable solvent-induced luminescence behavior by displaying various emitting colors instead of its sole characteristic red emission upon varying the nature of the solvent. Finally, amalgamating these two features, we are able to attain white light emission (Commission Internationale de l'Eclairage coordinates: x = 0.34, y = 0.38) at 283 K from a single component. A plausible energy transfer mechanism has also been proposed in light of the existence of the ligand-to-metal charge transfer (LMCT) state as the quencher.

20.
Acad Radiol ; 31(2): 390-398, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38160091

RESUMO

The COVID-19 pandemic brought unprecedented challenges in radiology education. RadDiscord, a digital, open-access radiology educational platform now with over 4100 members internationally, emerged as a COVID-era innovation that has transformed radiology education, broken down institutional silos, and equalized access to high-quality education. This special report will discuss the origin of RadDiscord, overcoming early barriers, building an organization and community, innovation and impact, and the future of radiological education. This may offer helpful perspectives to trainees and educators who are interested in innovating in the realm of radiology education.


Assuntos
COVID-19 , Radiologia , Humanos , Pandemias , Radiologia/educação , Radiografia , Escolaridade
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