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1.
Plant Cell Environ ; 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38533601

RESUMEN

As the global climate continues to change, plants will increasingly experience abiotic stress(es). Stomata on leaf surfaces are the gatekeepers to plant interiors, regulating gaseous exchanges that are crucial for both photosynthesis and outward water release. To optimise future crop productivity, accurate modelling of how stomata govern plant-environment interactions will be crucial. Here, we synergise optical and thermal imaging data to improve modelled transpiration estimates during water and/or nutrient stress (where leaf N is reduced). By utilising hyperspectral data and partial least squares regression analysis of six plant traits and fluxes in wheat (Triticum aestivum), we develop a new spectral vegetation index; the Combined Nitrogen and Drought Index (CNDI), which can be used to detect both water stress and/or nitrogen deficiency. Upon full stomatal closure during drought, CNDI shows a strong relationship with leaf water content (r2 = 0.70), with confounding changes in leaf biochemistry. By incorporating CNDI transformed with a sigmoid function into thermal-based transpiration modelling, we have increased the accuracy of modelling water fluxes during abiotic stress. These findings demonstrate the potential of using combined optical and thermal remote sensing-based modelling approaches to dynamically model water fluxes to improve both agricultural water usage and yields.

2.
J Surg Res ; 293: 196-203, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37778087

RESUMEN

INTRODUCTION: Despite advances in antiarrhythmia therapies, ventricular tachycardia (VT) is a leading cause of sudden cardiac death. Investigation into the characteristics and new treatments for this arrhythmia is required to improve outcomes and a reproducible model of VT would be useful in these endeavors. We therefore created a canine model of ischemia-induced VT. MATERIALS AND METHODS: A pacing lead was implanted in the right ventricle in canines (n = 13) and the left anterior descending artery was occluded in two locations for 2 h and subsequently released to create an ischemia-reperfusion injury. In the 10 dogs that survived the first 48 h following the initial study, a terminal study was conducted 4-7 d later and VT was induced using premature stimulation or burst pacing through the right ventricle lead. The arrhythmia was terminated using either antitachycardia pacing or a defibrillatory shock. Multiple inductions into sustained VT were attempted. RESULTS: Sustained VT was induced in eight of 10 dogs with an average cycle length of 335 ± 70 bpm. Multiple episodes of VT were induced. Episodes of VT exhibited different electrocardiogram morphologies and cycle lengths in individual animals. CONCLUSIONS: This canine model provides a consistent technique for inducing multiple episodes of sustained VT. It may be useful for investigating VT mechanisms and testing novel therapeutics and treatments for patients with VT.


Asunto(s)
Estimulación Cardíaca Artificial , Taquicardia Ventricular , Humanos , Perros , Animales , Estimulación Cardíaca Artificial/efectos adversos , Estimulación Cardíaca Artificial/métodos , Taquicardia Ventricular/etiología , Taquicardia Ventricular/terapia , Ventrículos Cardíacos , Electrocardiografía/efectos adversos , Isquemia/complicaciones
3.
Chem Soc Rev ; 52(2): 454-472, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36594823

RESUMEN

The design and development of functional materials with real-life applications are highly demanding. Understanding and controlling inter- and intra-molecular interactions provide opportunities to design new materials. A judicious manipulation of the molecular structure significantly alters such interactions and can boost selected properties and functions of the material. There is burgeoning evidence of the beneficial effects of non-covalent interactions (NCIs), showing that manipulating NCIs may generate functional materials with a wide variety of physical properties leading to applications in catalysis, drug delivery, crystal engineering, etc. This prompted us to review the implications of NCIs on the molecular packing, optical properties, and applications of functional π-conjugated materials. To this end, this tutorial review will cover different types of interactions (electrostatic, π-interactions, metallophilic, etc.) and their impact on π-conjugated materials. Attempts have also been made to delineate the effects of weak interactions on opto-electronic (O-E) applications.

4.
Am J Physiol Heart Circ Physiol ; 324(6): H751-H761, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-36961487

RESUMEN

Preclinical large animal models of chronic heart failure (HF) are crucial to both understanding pathological remodeling and translating fundamental discoveries into novel therapeutics for HF. Canine models of ischemic cardiomyopathy are historically limited by either high early mortality or failure to develop chronic heart failure. Twenty-nine healthy adult dogs (30 ± 4 kg, 15/29 male) underwent thoracotomy followed by one of three types of left anterior descending (LAD) coronary artery ligation procedures: group 1 (n = 4) (simple LAD: proximal and distal LAD ligation); group 2 (n = 14) (simple LAD plus lateral wall including ligation of the distal first diagonal and proximal first obtuse marginal); and group 3 (n = 11) (total LAD devascularization or TLD: simple LAD plus ligation of proximal LAD branches to both the right and left ventricles). Dogs were followed until chronic severe HF developed defined as left ventricular ejection fraction (LVEF) < 40% and NH2-terminal-prohormone B-type natriuretic peptide (NT-proBNP) > 900 pmol/L. Overall early survival (48-h postligation) in 29 dogs was 83% and the survival rate at postligation 5 wk was 69%. Groups 1 and 2 had 100% and 71% early survival, respectively, yet only a 50% success rate of developing chronic HF. Group 3 had excellent survival at postligation 48 h (91%) and a 100% success in the development of chronic ischemic HF. The TLD approach, which limits full LAD and collateral flow to its perfusion bed, provides excellent early survival and reliable development of chronic ischemic HF in canine hearts.NEW & NOTEWORTHY The novel total left anterior descending devascularization (TLD) approach in a canine ischemic heart failure model limits collateral flow in the ischemic zone and provides excellent early survival and repeatable development of chronic ischemic heart failure in the canine heart. This work provides a consistent large animal model for investigating heart failure mechanisms and testing novel therapeutics.


Asunto(s)
Insuficiencia Cardíaca , Función Ventricular Izquierda , Perros , Masculino , Animales , Volumen Sistólico , Insuficiencia Cardíaca/etiología , Corazón , Enfermedad Crónica , Modelos Animales de Enfermedad
5.
New Phytol ; 237(6): 2180-2195, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36630602

RESUMEN

A warming climate coupled with reductions in water availability and rising salinity are increasingly affecting rice (Oryza sativa) yields. Elevated temperatures combined with vapour pressure deficit (VPD) rises are causing stomatal closure, further reducing plant productivity and cooling. It is unclear what stomatal size (SS) and stomatal density (SD) will best suit all these environmental extremes. To understand how stomatal differences contribute to rice abiotic stress resilience, we screened the stomatal characteristics of 72 traditionally bred varieties. We found significant variation in SS, SD and calculated anatomical maximal stomatal conductance (gsmax ) but did not identify any varieties with SD and gsmax as low as transgenic OsEPF1oe plants. Traditionally bred varieties with high SD and small SS (resulting in higher gsmax ) typically had lower biomasses, and these plants were more resilient to drought than low SD and large SS plants, which were physically larger. None of the varieties assessed were as resilient to drought or salinity as low SD OsEPF1oe transgenic plants. High SD and small SS rice displayed faster stomatal closure during increasing temperature and VPD, but photosynthesis and plant cooling were reduced. Compromises will be required when choosing rice SS and SD to tackle multiple future environmental stresses.


Asunto(s)
Oryza , Estomas de Plantas , Oryza/genética , Fitomejoramiento , Plantas Modificadas Genéticamente , Estrés Fisiológico , Sequías , Agua
6.
J Cardiovasc Electrophysiol ; 34(5): 1249-1256, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37125623

RESUMEN

INTRODUCTION: Antitachycardia pacing (ATP) is used to terminate ventricular tachycardia (VT) by delivering rapid, low energy pacing to the right ventricle (RV). Unfortunately, ATP is not effective against all VT episodes and can result in adverse outcomes, such as VT acceleration and degeneration into ventricular fibrillation (VF). Improving ATP is therefore desirable. Our objective was to compare the efficacy and safety of ATP delivered at the His bundle to traditional ATP. METHODS: Six dogs were anesthetized and pacing leads were implanted in the RV and His bundle. The left anterior descending artery was occluded for 2 h to create an ischemic injury. In a study 4-7 days later, a 128-electrode sock was placed snugly around the ventricles and VT was induced using rapid pacing. ATP was delivered from either the His bundle or RV lead, then attempted at the other location if unsuccessful. Success rates and instances of VT acceleration and degeneration into VF were calculated. RESULTS: We induced 83 runs of VT and attempted ATP 128 times. RV ATP was successful in 36% of attempts; His ATP was successful in 38% of attempts. RV ATP resulted in significantly more adverse outcomes. RV and His ATP induced VT acceleration in 9% and 3% of trains, respectively, and induced degeneration into VF in 5% and 1% of trains, respectively. CONCLUSION: His bundle ATP is safer, but not significantly more effective, than RV ATP.


Asunto(s)
Desfibriladores Implantables , Taquicardia Ventricular , Perros , Animales , Ventrículos Cardíacos , Fascículo Atrioventricular , Estimulación Cardíaca Artificial/métodos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/terapia , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/terapia , Adenosina Trifosfato
7.
Chemistry ; 29(37): e202300376, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37062705

RESUMEN

Two novel nona-coordinated Eu(III) complexes [Eu(btfa)3 (Ph-TerPyr)] (Eu-1) and [Eu(NTA)3 (Ph-TerPyr)] (Eu-2) have been synthesized and characterized. The structure of the complexes was elucidated by density functional theory (DFT) methods. The experimental photophysical properties of the complexes were investigated and complemented with theoretical calculations. Effective energy transfer (ET) pathways for the sensitized red luminescence is discussed. The complexes were tested as emitting layers (EML) in organic light emitting diodes (OLEDs). At the optimum doping concentration of 4 wt.%, the double-EML OLEDs of Eu-1 exhibited red electroluminescence (EL) with an EQE of 4.0 % and maximum brightness (B)=1179 cd/m2 , maximum current efficiency (ηc )=5.64 cd/A, and maximum power efficiency (ηp )=4.78 lm/W at the current density (J) of 10 mA/cm2 . Interestingly, the double-EML OLEDs of Eu-2 at the optimum concentration of 3 wt.%, displayed an outstanding EL performance with EQE of 7.32 % and B=838 cd/m2 , ηc =10.19 cd/A and ηp =10.33 lm/W at J=10 mA/cm2 . The EL performance of this device is among the best reported for devices incorporating a europium complex as a red emitter.

8.
Eur J Immunol ; 51(7): 1774-1784, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33772778

RESUMEN

Optimal vaccines are needed for sustained suppression of SARS-CoV-2 and other novel coronaviruses. Here, we developed a recombinant type 5 adenovirus vector encoding the gene for the SARS-CoV-2 S1 subunit antigen (Ad5.SARS-CoV-2-S1) for COVID-19 immunization and evaluated its immunogenicity in mice. A single immunization with Ad5.SARS-CoV-2-S1 via S.C. injection or I.N delivery induced robust antibody and cellular immune responses. Vaccination elicited significant S1-specific IgG, IgG1, and IgG2a endpoint titers as early as 2 weeks, and the induced antibodies were long lasting. I.N. and S.C. administration of Ad5.SARS-CoV-2-S1 produced S1-specific GC B cells in cervical and axillary LNs, respectively. Moreover, I.N. and S.C. immunization evoked significantly greater antigen-specific T-cell responses compared to unimmunized control groups with indications that S.C. injection was more effective than I.N. delivery in eliciting cellular immune responses. Mice vaccinated by either route demonstrated significantly increased virus-specific neutralization antibodies on weeks 8 and 12 compared to control groups, as well as BM antibody forming cells (AFC), indicative of long-term immunity. Thus, this Ad5-vectored SARS-CoV-2 vaccine candidate showed promising immunogenicity following delivery to mice by S.C. and I.N. routes of administration, supporting the further development of Ad-based vaccines against COVID-19 and other infectious diseases for sustainable global immunization programs.


Asunto(s)
Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , COVID-19/prevención & control , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adenoviridae/genética , Adenoviridae/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , Inmunidad Celular/inmunología , Inmunidad Humoral/inmunología , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos BALB C , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Linfocitos T/inmunología , Vacunación
9.
Artículo en Inglés | MEDLINE | ID: mdl-35258449

RESUMEN

A polyhydroxybutyrate (PHB)-degrading actinomycete, strain SFB5AT, was identified as a species of Streptomyces based on its membrane fatty acid profile and the presence of ll-diaminopimelic acid in the cell wall. It formed sporulating mycelia on most agar media, but flat or wrinkled, moist colonies on trypticase soy agar. Spores were smooth, cylindrical, and borne on long, straight to flexuous chains. It produced a light brown diffusible pigment, but not melanin. Comparison of genomic digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values indicated that strain SFB5AT was related to Streptomyces litmocidini JCM 4394T, Streptomyces vietnamensis GIMV4.0001T, Streptomyces nashvillensis JCM 4498T and Streptomyces tanashiensis JCM 4086T, plus 11 other species. However, the dDDH and ANI values were well below the species differentiation thresholds of <70 and <95 %, respectively; also, multilocus sequence analysis distances exceeded the species threshold of 0.007. Moreover, strain SFB5AT differed from the other species in pigmentation and its ability to catabolize arabinose. Strain SFB5AT and 11 of its 15 closest relatives degraded PHB and have genes for extracellular, short-chain-length denatured polyhydroxyalkanoate depolymerases. These enzymes from strain SFB5AT and its closest relatives had a type 1 catalytic domain structure, while those from other relatives had a type 2 structure, which differs from type one in the position of a consensus histidine in the active site. Thus, phenotypic and genotypic differences suggest that strain SFB5AT represents a new species of Streptomyces, for which we propose the name Streptomyces nymphaeiformis sp. nov. The type strain is SFB5AT (=NRRL B-65520T=DSM 112030T).


Asunto(s)
Ácidos Grasos , Streptomyces , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptomyces/genética
10.
Molecules ; 27(13)2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35807497

RESUMEN

Trialkyl and triaryl phosphines are important classes of ligands in the field of catalysis and materials research. The wide usability of these low-valent phosphines has led to the design and development of new synthesis routes for a variety of phosphines. In the present work, we report the synthesis and characterization of some mixed arylalkyl tertiary phosphines via the Grignard approach. A new asymmetric phosphine is characterized extensively by multi-spectroscopic techniques. IR and UV-Vis spectra of some selected compounds are also compared and discussed. Density functional theory (DFT)-calculated results support the formation of the new compounds.


Asunto(s)
Fosfinas , Catálisis , Ligandos , Fosfinas/química
11.
J Community Psychol ; 50(3): 1454-1469, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34626493

RESUMEN

Global warming is occurring at an alarming rate, with climate change creating severe water-related hazards that are at the top of the natural disasters list. The highest human losses have been recorded in the past 50 years based on world meteorological organization calculations. Thus, everyone needs to play their part in environmental sustainability (ES). This will require a change in behavior; therefore, the current study considered pro-environmental behavior (PEB) crucial to ES among university employees. The moderating effect of green organizational culture (GOC) on the relationship between PEB and ES was also investigated. As it is typical of a Thai public university to expend a considerable amount of natural resources in the process of conducting its routine academic and operational activities, it is a setting worthy of investigation. The higher education sector is rarely explored in the areas of resource use and conservation; for this reason, this study was specifically targeted at the human factor in this specialized setting. A survey was performed on the faculty members of Thai public universities to verify the model. It was found that PEB influenced ES, and GOC moderated the relationship between PEB and ES. The results encompassed six dimensions of PEB and the moderating effect of GOC in the context of higher educational institutions. The findings have provided new insights into PEB intervention and modification in the context of higher education institutions whose management may use the results to strengthen employees' PEB by offering information, knowledge, and training.


Asunto(s)
Cultura Organizacional , Organizaciones , Humanos , Encuestas y Cuestionarios , Universidades
12.
Omega (Westport) ; 85(3): 574-578, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32807008

RESUMEN

Aortic dissections and aneurysms (ADA) are associated with significant morbidity and mortality, and location of death for these patients is important in determining impact on end of life care. We analyzed the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research database. Black and Hispanic backgrounds had decreased odds of dying at home from ADA. Married or educated individuals tended to die at home at a higher rate than unmarried individuals. Overall, we have shown place of death in individuals with ADA is different among individuals of different demographics.


Asunto(s)
Aneurisma de la Aorta , Disección Aórtica , Cuidados Paliativos al Final de la Vida , Cuidado Terminal , Humanos
13.
Am J Physiol Heart Circ Physiol ; 320(1): H13-H22, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33124884

RESUMEN

His bundle pacing utilizes the His-Purkinje system to produce more physiological activation compared with traditional pacing therapies, but differences in electrical activation between pacing techniques are not yet quantified in terms of activation pattern. Furthermore, clinicians distinguish between selective and nonselective His pacing, but measurable differences in electrical activation remain to be seen. Hearts isolated from seven dogs were perfused using the Langendorff method. Electrograms were recorded using two 64-electrode basket catheters in the ventricles and a 128-electrode sock situated around the ventricles during sinus rhythm (right atrial pacing), right ventricular (RV) pacing, biventricular cardiac resynchronization therapy (biV-CRT), selective His pacing (selective capture of the His bundle), and nonselective His pacing (capture of nearby myocardium and His bundle). Activation maps were generated from these electrograms. Total activation time (TAT) was measured from the activation maps, and QRS duration was measured from a one-lead pseudo-ECG. Results showed that TAT, QRS duration, and activation sequence were most similar between sinus, selective, and nonselective His pacing. Bland-Altman analyses showed highest levels of similarity between all combinations of sinus, selective, and nonselective His pacing. RV and biV-CRT activation patterns were distinct from sinus and had significantly longer TAT and QRS duration. Cumulative activation graphs were most similar between sinus, selective, and nonselective His pacing. In conclusion, selective pacing and nonselective His bundle pacing are more similar to sinus compared with RV and biV-CRT pacing. Furthermore, selective pacing and nonselective His bundle pacing are not significantly different electrically.NEW & NOTEWORTHY Our high-density epicardial and endocardial electrical mapping study demonstrated that selective pacing and nonselective His bundle pacing are more electrically similar to sinus rhythm compared with right ventricular and biventricular cardiac resynchronization therapy pacing. Furthermore, small differences between selective and nonselective His bundle pacing, specifically a wider QRS in nonselective His pacing, do not translate into significant differences in the global activation pattern.


Asunto(s)
Potenciales de Acción , Fascículo Atrioventricular/fisiología , Estimulación Cardíaca Artificial/métodos , Frecuencia Cardíaca , Ramos Subendocárdicos/fisiología , Animales , Función del Atrio Derecho , Dispositivos de Terapia de Resincronización Cardíaca , Perros , Técnicas Electrofisiológicas Cardíacas , Preparación de Corazón Aislado , Masculino , Factores de Tiempo , Función Ventricular Izquierda , Función Ventricular Derecha
14.
Inorg Chem ; 60(2): 745-759, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33382607

RESUMEN

Pt(II) diynes and polyynes incorporating 5,5'- and 6,6'-disubstituted 2,2'-bipyridines were prepared following conventional Sonogashira and Hagihara dehydrohalogenation reaction protocols. Using Pt(II) dimers and polymers as a rigid-rod backbone, four new heterobimetallic compounds incorporating Re(CO)3Cl as a pendant functionality in the 2,2'-bipyridine core were obtained. The new heterobimetallic Pt-Re compounds were characterized by analytical and spectroscopic techniques. The solid-state structures of a Re(I)-coordinated diterminal alkynyl ligand and a representative model compound were determined by single-crystal X-ray diffraction. Detailed photophysical characterization of the heterobimetallic Pt(II) diynes and polyynes was carried out. We find that the incorporation of the Re(CO)3Cl pendant functionality in the 2,2'-bipyridine-containing main-chain Pt(II) diynes and polyynes has a synergistic effect on the optical properties, red shifting the absorption profile and introducing strong long-wavelength absorptions. The Re(I) moiety also introduces strong emission into the monomeric Pt(II) diyne compounds, whereas this is suppressed in the polyynes. The extent of the synergy depends on the topology of the ligands. Computational modeling was performed to compare the energetic stabilities of the positional isomers and to understand the microscopic nature of the major optical transitions. We find that 5,5'-disubstituted 2,2'-bipyridine systems are better candidates in terms of yield, photophysical properties, and stability than their 6,6'-substituted counterparts. Overall, this work provides an additional synthetic route to control the photophysical properties of metallaynes for a variety of optoelectronic applications.

15.
J Electrocardiol ; 69: 36-43, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34555557

RESUMEN

BACKGROUND: postoperative atrial fibrillation (POAF) is a common cardiac surgery complication that is associated with increased complications and negative outcomes, but the association between presurgical atrial conduction abnormalities and POAF has not been investigated clinically during premature atrial S1S2 stimulation. This clinical study sought to examine whether intraoperative premature atrial stimulation reveals increased areas of slowed and/or blocked conduction in patients that develop POAF. METHODS: High-density intraoperative epicardial left atrial mapping was conducted in 20 cardiac surgery patients with no prior history of atrial fibrillation (AF). In 20 patients, 6 (30%) developed POAF. A flexible-array of 240-electrodes was placed on the posterior left atrial wall in between the pulmonary veins. Activation maps were generated for sinus and premature atrial S1S2 stimulated beats. The area of conduction block (CB), conduction delay (CD) and the combination of both (CDCB) for conduction velocity < 0.1, 0.1 ≤ x < 0.2 and < 0.2 m/s, respectively were quantified. RESULTS: For a premature atrial S2 beat with shortest cycle length captured, conduction velocity maps revealed a significantly higher area for CD (13.19 ± 6.59 versus 6.06 ± 4.22 mm2, p = 0.028) and CDCB (17.36 ± 8.75 versus 7.41 ± 6.39 mm2, p = 0.034), and a trend toward a larger area for CB (4.17 ± 3.66 versus 1.34 ± 2.86 mm2, p = 0.063) in patients who developed POAF in comparison to those that remained in the sinus. Sinus and S1 paced beats did not show substantial differences in abnormal conduction areas between patients with and without POAF. CONCLUSION: In comparison to sinus and S1 beats, premature atrial S2 beats accentuate conduction abnormalities in the posterior left atrial wall of cardiac surgery patients that developed POAF.


Asunto(s)
Fibrilación Atrial , Procedimientos Quirúrgicos Cardíacos , Fibrilación Atrial/etiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Electrocardiografía , Atrios Cardíacos , Humanos , Complicaciones Posoperatorias/etiología
16.
Chem Rev ; 118(18): 8474-8597, 2018 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-30112905

RESUMEN

Conjugated poly-ynes and poly(metalla-ynes) constitute an important class of new materials with potential application in various domains of science. The key factors responsible for the diverse usage of these materials is their intriguing and tunable chemical and photophysical properties. This review highlights fascinating advances made in the field of conjugated organic poly-ynes and poly(metalla-ynes) incorporating group 4-11 metals. This includes several important aspects of conjugated poly-ynes viz. synthetic protocols, bonding, electronic structure, nature of luminescence, structure-property relationships, diverse applications, and concluding remarks. Furthermore, we delineated the future directions and challenges in this particular area of research.

17.
Biomed Eng Online ; 19(1): 19, 2020 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-32276597

RESUMEN

BACKGROUND: The His-Purkinje (HP) system provides a pathway for the time-synchronous contraction of the heart. His bundle (HB) of the HP system is gaining relevance as a pacing site for treating non-reversible bradyarrhythmia despite limited availability of tools to identify the HB. In this paper, we describe a real-time stimulation and recording system (rt-SRS) to investigate using multi-electrode techniques to identify and selectively pace the HB. The rt-SRS can not only be used in sinus rhythm, but also during ventricular fibrillation (VF). The rt-SRS will also help investigate the so far unknown causal effects of selectively pacing the HB during VF. METHODS: The rt-SRS consists of preamplifiers, data acquisition cards interfaced with a real-time controller, a current source, and current routing switches on a remote computer, which may be interrupted to stimulate using a host machine. The remote computer hosts a series of algorithms designed to aid in identifying electrodes directly over the HB, to accurately detect activation rates without over-picking, and to deliver stimulation pulses. The performance of the rt-SRS was demonstrated in seven isolated, perfused rabbit hearts. RESULTS: The rt-SRS can visualize up to 96 channels of raw data, and spatial derivative data at 6.25-kHz sampling rate with an input-referred noise of 100 µV. The rt-SRS can send up to ± 150 V of stimuli pulses to any of the 96 channels. In the rabbit experiments, HB activations were detected in 18 ± 6.8% of the 64 electrodes used during VF. CONCLUSIONS: The rt-SRS is capable of measuring and responding to cardiac electrophysiological phenomena in real-time with precisely timed and placed electrical stimuli. This rt-SRS was shown to be an effective research tool by successfully detecting and quantifying HB activations and delivering stimulation pulses to selected electrodes in real-time.


Asunto(s)
Fascículo Atrioventricular/fisiopatología , Electrofisiología/instrumentación , Fibrilación Ventricular/fisiopatología , Algoritmos , Animales , Sistemas de Computación , Electrodos , Conejos
18.
J Cardiothorac Vasc Anesth ; 34(7): 1933-1941, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31653497

RESUMEN

Postoperative atrial fibrillation (POAF) after cardiac surgery remains a highly prevalent and costly condition that negatively impacts patient quality of life and survival. Numerous retrospective studies, meta-analysis, and review papers have been reported identifying POAF risk based on patients' risk factors and clinical biomarkers. In this narrative review, the authors report significant variations among selected pre- and perioperative biomarkers used to predict POAF incidence in patients without a history of atrial fibrillation (AF). POAF prediction based on B-type natriuretic peptide, N-terminal pro B-type natriuretic peptide, C-reactive protein, interleukin-6, creatinine, and plasminogen activator inhibitor-1 differs significantly among different studies, thereby limiting their clinical utility to predict POAF risk with high accuracy. Conversely, soluble vascular endothelial cells adhesion molecule-1, soluble CD40 ligand, Galectin-3, and aldosterone show promise for better POAF prediction. However, the current datasets for these selected biomarkers are not of sufficient size to validate the broad clinical application specifically for patients with no prior history of AF.


Asunto(s)
Fibrilación Atrial , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Fibrilación Atrial/etiología , Biomarcadores , Puente de Arteria Coronaria/efectos adversos , Células Endoteliales , Humanos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Calidad de Vida , Estudios Retrospectivos , Factores de Riesgo
19.
Chem Soc Rev ; 48(23): 5547-5563, 2019 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-31720563

RESUMEN

Square planar platinum(ii) complexes have been known for 150 years and pincer complexes, supported by a tridentate chelating ligand such as terpyridyl, have been known for more than 70 years. The development of cyclometallated platinum(ii) pincer complexes, in which the tridentate ligand forms one or more platinum-carbon bonds, has been much more recent. Particularly, in terms of their solution and solid-state luminescence these cyclometallated complexes show substantial advantages over their terpyridyl analogues. This tutorial review introduces the reader to the area of platinum(ii) cyclometallated pincer chemistry and shows the advantage of having an alkynyl group in the fourth coordination site on the metal. The basic design principles for the preparation of highly luminescent platinum(ii) cyclometallated pincer complexes are outlined and the strategy to improve the luminescence further by chemical manipulation of the pincer ligand and of the auxiliary ligand in the fourth coordination site are illustrated with recent examples from the literature. Recent applications of these cyclometallated pincer complexes in the area of opto-electronics is described, with emphasis on their use in OLEDs, OFETs and as NLO materials as well as demonstrating their potential use as triplet photosensitizers and as metal ion sensors. The aim of this review is to show the recent advances in this rapidly developing research field and to highlight the future promise of these materials.

20.
Int J Mol Sci ; 21(11)2020 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-32481556

RESUMEN

Inflammation is a hallmark of many metabolic diseases. We previously showed that ferrocene-appended 1H-1,2,3-triazole hybrids inhibit nitric oxide (NO) production in in vitro models of lipopolysaccharide-induced inflammation in the BV-2 cell. In the present study, we explored the viability, anti-inflammatory, and antioxidant potential of ferrocene-1H-1,2,3-triazole hybrids using biochemical assays in rat mesangial cells (RMCs). We found that, among all the ferrocene-1H-1,2,3-triazole hybrids, X2-X4 exhibited an antioxidant effect on mitochondrial free radicals. Among all the studied compounds, X4 demonstrated the best anti-inflammatory effect on RMCs. These results were supplemented by in silico studies including molecular docking with human cytosolic phospholipase A2 (cPLA2) and cyclooxygenase 2 (COX-2) enzymes as well as absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling. Besides, two new crystal structures of the compounds have also been reported. In addition, combining the results from the inducible nitric oxide synthase (iNOS), cPLA2, COX-2, and matrix metalloproteinase-9 (MMP-9) enzymatic activity analysis and NO production also confirmed this argument. Overall, the results of this study will be a valuable addition to the growing body of work on biological activities of triazole-based compounds.


Asunto(s)
Antiinflamatorios/farmacología , Antioxidantes/farmacología , Enfermedades Renales/tratamiento farmacológico , Células Mesangiales/efectos de los fármacos , Triazoles/farmacología , Animales , Antioxidantes/metabolismo , Supervivencia Celular/efectos de los fármacos , Celobiosa/análogos & derivados , Cristalografía por Rayos X , Ciclooxigenasa 2/metabolismo , Radicales Libres , Fosfolipasas A2 Grupo IV/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Lipopolisacáridos/farmacología , Metaloproteinasa 9 de la Matriz/metabolismo , Células Mesangiales/metabolismo , Mitocondrias/metabolismo , Simulación del Acoplamiento Molecular , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Ratas
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