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The analysis of the shift in photoluminescence emission for a blend of polyvinylcarbazole and acrylonitrile derivative compounds is reported. The small-molecule compounds have different functional groups, phenyl, pyridine, or methyl phenyl, attached to an acrylonitrile group. According to the functional group, the blue emission for pure dye shifts to green or yellowish in the blend film. Several PVK:dye ratios from 0:100 to 20:80 were used for film deposition. The film morphology was analyzed by atomic force microscopy; for low dye content, homogeneous films were achieved. However, aggregates of several micrometers are formed on the surface of films with higher dye concentrations. The shift in emission occurs only with PVK, and for a non-conjugated matrix such as polystyrene, the emission remains unchanged. The interaction of dyes with PVK leading to change in emission was also achieved by grinding dye and polymer. Results showed that shifts in emission could come from exciplex formation along with changes in dye intermolecular interactions. The blend films were highly transparent in the visible spectra due to the absorption in the UV region for dye and matrix. The films with ratio PVK: dye ratio 80:20 was used as active layer in OLEDs.
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PURPOSE: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease characterized by persistent fatigue and decreased daily activity following physical and/or cognitive exertion. While ME/CFS affects both sexes, there is a higher prevalence in women. However, studies evaluating this sex-related bias are limited. METHODS: Circulating steroid hormones, including mineralocorticoids (aldosterone), glucocorticoids (cortisol, corticosterone, 11-deoxycortisol, cortisone), androgens (androstenedione, testosterone), and progestins (progesterone, 17α-hydroxyprogesterone), were measured in plasma samples using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Samples were obtained from mild/moderate (ME/CFSmm; females, n=20; males, n=8), severely affected patients (ME/CFSsa; females, n=24; males, n=6), and healthy controls (HC, females, n=12; males, n=17). RESULTS: After correction for multiple testing, we observed that circulating levels of 11-deoxycortisol, 17α-hydroxyprogesterone in females, and progesterone in males were significantly different between HC, ME/CFSmm, and ME/CFSsa. Comparing two independent groups, we found that female ME/CFSsa had higher levels of 11-deoxycortisol (vs. HC and ME/CFSmm) and 17α-hydroxyprogesterone (vs. HC). In addition, female ME/CFSmm showed a significant increase in progesterone levels compared to HC. In contrast, our study found that male ME/CFSmm had lower circulating levels of cortisol and corticosterone, while progesterone levels were elevated compared to HC. In addition to these univariate analyses, our correlational and multivariate approaches identified differential associations between our study groups. Also, using two-component partial least squares discriminant analysis (PLS-DA), we were able to discriminate ME/CFS from HC with an accuracy of 0.712 and 0.846 for females and males, respectively. CONCLUSION: Our findings suggest the potential value of including steroid hormones in future studies aimed at improving stratification in ME/CFS. Additionally, our results provide new perspectives to explore the clinical relevance of these differences within specific patient subgroups.
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PURPOSE: The superior orbital fissure contains cranial nerves III, IV, VI, and V1 with their three branches: frontal, lacrimal, and nasociliary. Superior orbital fissure syndrome (SOFS) is rare and can occur as a result of compression of these nerves due to trauma, bleeding, or inflammation in the retrobulbar space, but no cases of SOFS after deep lateral orbital wall decompression (DLOWD) have been reported. The aim of this paper is to describe this pathology, its possible causes, management, and outcome. METHODS: Retrospective study of 575 DLOWD in patients with disfiguring exophthalmos due to Graves' ophthalmopathy performed in our hospital between 2010 and 2023. Three cases of postoperative SOFS were identified based on clinical presentation, history, physical examination, and radiological study. All patients were observed for a minimum of 12 months. RESULTS: SOFS was diagnosed with the presence of ophthalmoplegia, ptosis, fixed and dilated pupils, hypo/anesthesia of the upper eyelid and forehead, loss of corneal reflex, and no loss of vision after DLOWD. Fractures, edema, and hemorrhages were excluded. They were treated with high-dose intravenous steroids and the patients recovered completely. CONCLUSIONS: DLOWD challenges orbital surgeons because it requires removing bones near the globe or neurovascular structures. SOFS may occur due to the proximity and increased pressure on these structures.
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Descompresión Quirúrgica , Oftalmopatía de Graves , Órbita , Humanos , Estudios Retrospectivos , Oftalmopatía de Graves/cirugía , Femenino , Persona de Mediana Edad , Órbita/cirugía , Masculino , Adulto , Tomografía Computarizada por Rayos X , Síndrome , Síndromes de Compresión Nerviosa/etiología , Síndromes de Compresión Nerviosa/cirugía , Complicaciones Posoperatorias , Imagen por Resonancia MagnéticaRESUMEN
Endothelial progenitor cells (EPCs) are stem cells mainly derived from bone marrow; from where they migrate to repair and regenerate damaged tissues. eEPCs have been classified into two sub-populations, early (eEPC) and late EPCs (lEPC), depending on maturation stages in vitro. In addition, eEPC release endocrine mediators, including small extracellular vesicles (sEVs), which in turn may enhance the eEPC-mediated wound healing properties. Nevertheless, adenosine contributes to angiogenesis by recruiting eEPC at the injury site. However, whether ARs may enhance the secretome of eEPC, including sEVs, is unknown. Therefore, we aimed to investigate whether AR activation increase the release of sEVs in eEPC, which in turn has paracrine effects on recipient endothelial cells. Results shown that 5'-N-ethylcarboxamidoadenosine (NECA), a non-selective agonist, increase both the protein levels of the vascular endothelial growth factor (VEGF), and the number of sEVs released to the conditioned medium (CM) in primary culture of eEPC. Importantly, CM and EVs harvested from NECA-stimulated eEPC promote in vitro angiogenesis, without changes in cell proliferation, in recipient ECV-304 endothelial cells. This constitutes the first evidence showing that adenosine enhances sEVs release from eEPC, which has pro-angiogenic capacity on recipient endothelial cells.
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Células Progenitoras Endoteliales , Humanos , Células Progenitoras Endoteliales/metabolismo , Adenosina/farmacología , Adenosina/metabolismo , Adenosina-5'-(N-etilcarboxamida)/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Células Madre/metabolismo , Medios de Cultivo Condicionados/metabolismoRESUMEN
PURPOSE: To understand the natural history and optimal treatment strategy for pituitary gland metastasis. METHODS: We performed both a retrospective chart review of patients treated at our institution and a scoping review of the topic. RESULTS: The retrospective review identified seven patients with an average age of 59.6 years. Primary histologies included breast cancer (4), melanoma (1), renal cell carcinoma (1), and sarcoma (1). Two patients had anterior pituitary endocrine dysfunction, one of whom was the only patient with visual symptoms. All patients were treated with radiosurgery and two also underwent surgical resection. Overall survival ranged from 6.5 to 117 months. Literature review identified 166 patients from 71 studies. The most common primary cancer was lung (27.7%), followed by breast (18.7%) and renal (14.5%) cancer. 107 presented with endocrine dysfunction, including 41 cases of diabetes insipidus and 55 cases of hypopituitarism. 110 presented with visual compromise. 107 patients received radiotherapy, 96 underwent surgical resection and 44 received systemic chemotherapy/immunotherapy. Surgery was significantly associated with an increased likelihood of vision improvement and a decreased likelihood of endocrine normalization. Radiographic regression predicted visual improvement. Median overall survival was 9.9 months (range: 0.2-96). CONCLUSIONS: This scoping review showed that both radiosurgery and surgical resection have been frequently used to treat pituitary metastases with good response. Vision improvement is more likely to happen following surgical resection, likely at the expense of endocrine dysfunction. Despite treatment and radiographic response, patient survival remains less than a year.
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Carcinoma de Células Renales , Diabetes Insípida , Neoplasias Renales , Neoplasias Hipofisarias , Radiocirugia , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias Hipofisarias/cirugía , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND: Metastasis is the most common brain tumor in adults. It is the standard of care at most North American centers to obtain an early postoperative imaging after their resection. However, the necessity of this practice in the absence of a new postoperative deficit remains unclear. METHODS: We retrospectively reviewed our surgical cohort of patients who underwent resection of brain metastases from July 2018 to June 2019. We collected demographic data and reviewed results of routine postoperative CT scans and neurological morbidities to examine the diagnostic and therapeutic yield of an early postoperative scan. In addition, we performed a systematic review of the topic. RESULTS: Our review included 130 patients, all of whom underwent gross total resection of one or more brain metastases. On postoperative CT, none had unexpected findings such as cavity hematoma or new ischemia; no changes in management resulted from postoperative imaging. One patient required a higher dose of dexamethasone on postoperative day 4 for delayed hemiparesis and aphasia due to cerebral edema. Three additional patients underwent a wound washout for delayed infection during a subsequent admission. Our systematic review identified three additional studies; in a combined cohort of 450 patients (including our own), no patients had clinically actionable findings on routine postoperative CT. CONCLUSIONS: Following resection of brain metastases, a routine postoperative CT scan has low diagnostic yield and did not change patient management in any cases examined in this work.
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Neoplasias Encefálicas , Tomografía Computarizada por Rayos X , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Craneotomía , Humanos , Periodo Posoperatorio , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodosRESUMEN
Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN.
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Aterosclerosis , Células Progenitoras Endoteliales , Ftalazinas , Animales , Aorta/metabolismo , Aorta/patología , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/etiología , Aterosclerosis/metabolismo , Aterosclerosis/patología , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Células Progenitoras Endoteliales/efectos de los fármacos , Células Progenitoras Endoteliales/metabolismo , Células Progenitoras Endoteliales/patología , Inflamación/tratamiento farmacológico , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Lipoproteínas LDL/metabolismo , Hígado/metabolismo , Ratones , Ftalazinas/farmacología , Receptores Depuradores de Clase E/genética , Receptores Depuradores de Clase E/metabolismoRESUMEN
PURPOSE: Orbital tumor surgery can be challenging when the tumor is located in a very narrow surgical field and close to important structures, such as nerves or extraocular muscles that can be damaged during surgery. Advances in technology and special surgical techniques help to avoid such damage. We describe our experience using SONOPET® ultrasonic surgical aspirator to remove 12 different orbital tumors that were difficult to treat due to their poorly defined borders, adhesions, or location. METHODS: This is a retrospective case series that describes 12 operations that occurred between March 2016 to December 2018 using an ultrasonic device to debulk or remove orbital tumors. Different approaches and handpieces were used for each case depending on the location and consistency of the tumor. RESULTS: All patients experienced an improvement in preoperative signs and symptoms, pain, proptosis, diplopia, or lagophthalmos. Visual acuity, which had been reduced due to the tumor, was also recovered. There were no intraoperative or postoperative complications due to the use of the device. CONCLUSIONS: The ultrasonic aspirator is a safe, useful device that can successfully remove or debulk infiltrating orbital masses through any orbital access, regardless of their consistency. It is helpful in cases of difficult anatomical access or difficult extraction due to size or adhesions to the surrounding tissues.
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Exoftalmia , Neoplasias Orbitales , Exoftalmia/cirugía , Humanos , Órbita/diagnóstico por imagen , Órbita/cirugía , Neoplasias Orbitales/diagnóstico por imagen , Neoplasias Orbitales/cirugía , Estudios Retrospectivos , UltrasonidoRESUMEN
PURPOSE: Differentiation of radiation necrosis from tumor progression in brain metastases treated with stereotactic radiosurgery (SRS) is challenging. For this, we assessed the performance of the centrally restricted diffusion sign. METHODS: Patients with brain metastases treated with SRS who underwent a subsequent intervention (biopsy/resection) for a ring-enhancing lesion on preoperative MRI between 2000 and 2020 were included. Excluded were lesions containing increased susceptibility limiting assessment of DWI. Two neuroradiologists classified the location of the diffusion restriction with respect to the post-contrast T1 images as centrally within the ring-enhancement (the centrally restricted diffusion sign), peripherally correlating to the rim of contrast enhancement, both locations, or none. Measures of diagnostic accuracy and 95% CI were calculated for the centrally restricted diffusion sign. Cohen's kappa was calculated to identify the interobserver agreement. RESULTS: Fifty-nine patients (36 female; mean age 59, range 40 to 80) were included, 36 with tumor progression and 23 with radiation necrosis based on histopathology. Primary tumors included 34 lung, 12 breast, 5 melanoma, 3 colorectal, 2 esophagus, 1 head and neck, 1 endometrium, and 1 thyroid. The centrally restricted diffusion sign was seen in 19/23 radiation necrosis cases (sensitivity 83% (95% CI 63 to 93%), specificity 64% (95% CI 48 to 78%), PPV 59% (95% CI 42 to 74%), NPV 85% (95% CI 68 to 94%)) and 13/36 tumor progression cases (difference p < 0.001). Interobserver agreement was substantial, at 0.61 (95% CI 0.45 to 70.8). CONCLUSION: We found a low probability of radiation necrosis in the absence of the centrally restricted diffusion sign.
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Neoplasias Encefálicas , Traumatismos por Radiación , Radiocirugia , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Necrosis/diagnóstico por imagen , Necrosis/etiología , Necrosis/patología , Traumatismos por Radiación/diagnóstico por imagen , Traumatismos por Radiación/etiología , Traumatismos por Radiación/cirugía , Radiocirugia/efectos adversos , Radiocirugia/métodos , Estudios RetrospectivosRESUMEN
Brain metastases (BM) are the most common intracranial neoplasm and represent a major clinical challenge across many medical disciplines. The incidence of BM is increasing, largely due to improvements in primary disease therapeutics conferring greater systemic control, and advancements in neuroimaging techniques and availability leading to earlier diagnosis. In recent years, the landscape of BM treatment has changed significantly with the advent of personalized targeted chemotherapies and immunotherapy, the adoption of focal radiotherapy (RT) for higher intracranial disease burden, and the implementation of new surgical strategies. The increasing permutations of options available for the treatment of patients diagnosed with BM necessitate coordinated care by a multidisciplinary team. This review discusses the current treatment regimens for BM as well as examines the salient features of a modern multidisciplinary approach.
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Neoplasias Encefálicas , Neoplasias Encefálicas/terapia , Humanos , Inmunoterapia , IncidenciaRESUMEN
The compounds I (Z)-2-(phenyl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile with one side (2,4,5-MeO-), one symmetrical (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(2,4,5-trimethoxyphenyl)acrylonitrile), II (both sides with (2,4,5-MeO-), and three positional isomers with pyridine (Z)-2-(pyridin-2- 3, or 4-yl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile, III-V were synthetized and characterized by UV-Vis, fluorescence, IR, H1-NMR, and EI mass spectrometry as well as single crystal X-ray diffraction (SCXRD). The optical properties were strongly influenced by the solvent (hyperchromic and hypochromic shift), which were compared with the solid state. According to the solvatochromism theory, the excited-state (µe) and ground-state (µg) dipole moments were calculated based on the variation of Stokes shift with the solvent's relative permittivity, refractive index, and polarity parameters. SCXRD analyses revealed that the compounds I and II crystallized in the monoclinic system with the space group, P21/n and P21/c, respectively, and with Z = 4 and 2. III, IV, and V crystallized in space groups: orthorhombic, Pbca; triclinic, P-1; and monoclinic, P21 with Z = 1, 2, and 2, respectively. The intermolecular interactions for compounds I-V were investigated using the CCDC Mercury software and their energies were quantified using PIXEL. The density of states (DOS), molecular electrostatic potential surfaces (MEPS), and natural bond orbitals (NBO) of the compounds were determined to evaluate the photophysical properties.
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Insulin regulates the l-arginine/nitric oxide (NO) pathway in human umbilical vein endothelial cells (HUVECs), increasing the plasma membrane expression of the l-arginine transporter hCAT-1 and inducing vasodilation in umbilical and placental veins. Placental vascular relaxation induced by insulin is dependent of large conductance calcium-activated potassium channels (BKCa), but the role of KCa channels on l-arginine transport and NO synthesis is still unknown. The aim of this study was to determine the contribution of KCa channels in both insulin-induced l-arginine transport and NO synthesis, and its relationship with placental vascular relaxation. HUVECs, human placental vein endothelial cells (HPVECs) and placental veins were freshly isolated from umbilical cords and placenta from normal pregnancies. Cells or tissue were incubated in absence or presence of insulin and/or tetraethylammonium, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole, iberiotoxin or NG-nitro-l-arginine methyl ester. l-Arginine uptake, plasma membrane polarity, NO levels, hCAT-1 expression and placenta vascular reactivity were analyzed. The inhibition of intermediate-conductance KCa (IKCa) and BKCa increases l-arginine uptake, which was related with protein abundance of hCAT-1 in HUVECs. IKCa and BKCa activities contribute to NO-synthesis induced by insulin but are not directly involved in insulin-stimulated l-arginine uptake. Long term incubation (8 h) with insulin increases the plasma membrane hyperpolarization and hCAT-1 expression in HUVECs and HPVECs. Insulin-induced relaxation in placental vasculature was reversed by KCa inhibition. The results show that the activity of IKCa and BKCa channels are relevant for both physiological regulations of NO synthesis and vascular tone regulation in the human placenta, acting as a part of negative feedback mechanism for autoregulation of l-arginine transport in HUVECs.
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Canales de Potasio de Conductancia Intermedia Activados por el Calcio/metabolismo , Canales de Potasio de Gran Conductancia Activados por el Calcio/metabolismo , Óxido Nítrico/metabolismo , Venas Umbilicales/metabolismo , Adulto , Arginina/metabolismo , Transportador de Aminoácidos Catiónicos 1/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Femenino , Células Endoteliales de la Vena Umbilical Humana , Humanos , Insulina/farmacología , Canales de Potasio de Conductancia Intermedia Activados por el Calcio/antagonistas & inhibidores , Canales de Potasio de Gran Conductancia Activados por el Calcio/antagonistas & inhibidores , Péptidos/farmacología , Placenta/efectos de los fármacos , Placenta/metabolismo , Bloqueadores de los Canales de Potasio/farmacología , Embarazo , Pirazoles/farmacología , Venas Umbilicales/efectos de los fármacos , Adulto JovenRESUMEN
OBJECTIVE: To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. METHODS: Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. RESULTS: The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256µg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. CONCLUSION: OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.
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Purpose: To share our experience on deep lateral wall rim-sparing orbital decompression for the prevention of further spontaneous globe subluxation, in patients with shallow orbits and eyelid laxity.Methods: This is a retrospective, interventional case series review. We report the results of deep lateral wall rim-sparing orbital decompression in 7 patients with recurrent spontaneous globe subluxation, operated in our department between 2010 and 2016. The orbital morphology was established by computed tomography scan images, and all patients with shallow orbit configuration and who in addition had eyelid laxity were included. Patients with thyroid eye disease were excluded.Results: No significant intraoperative and postoperative complications were encountered. In all cases, the patients were satisfied with the aesthetic result and none reported further episodes of globe subluxation.Conclusions: Deep lateral wall rim-sparing orbital decompression is a safe and effective decompressive procedure associated with minimal complications, which can be performed successfully in patients with spontaneous globe subluxation associated with shallow orbits with enough eyelid laxity.
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Descompresión Quirúrgica/métodos , Exoftalmia/cirugía , Órbita/cirugía , Anciano , Párpados/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
PulseNet Latin America and Caribbean (PNLAC) was established in 2003 and is one of seven Regional networks within PulseNet International. The main objectives of the network are to strengthen national and regional laboratory-based foodborne disease surveillance for early detection and investigation of outbreaks to setup control and prevention strategies in contribution to Public Health. Participants perform standardized pulsed-field gel electrophoresis (PFGE) protocols and analysis. For functioning, it is important for the network, the development of national and regional databases (RDBs) and the communication between countries, regionally and internationally. Metadata from over 8600 cases/outbreaks are profiled and isolated by PFGE and are incorporated into the RDB, hosted by the Pan American Health Organization. Currently PNLAC is moving toward whole-genome sequencing to use as a complementary strategy for surveillance. The aim of this article was to describe the experience of the construction of PNLAC, and its contribution to the surveillance of the foodborne diseases at the country and regional levels.
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Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Vigilancia en Salud Pública , Técnicas de Tipificación Bacteriana , Región del Caribe/epidemiología , ADN Bacteriano/análisis , Bases de Datos Factuales , Brotes de Enfermedades/prevención & control , Electroforesis en Gel de Campo Pulsado , Humanos , Laboratorios , América Latina/epidemiología , Secuenciación Completa del GenomaRESUMEN
Production of second-generation bioethanol uses lignocellulose from agricultural by-products such as sugarcane bagasse (SCB). A lignocellulose pre-treatment is required to degrade lignin, ensuring further efficient saccharification. Two experimental designs were set up to define culture conditions of Pycnoporus sanguineus in mesocosms to increase laccase activities and thus delignification. The first experimental design tested the effect of phenolic complementation (via coffee pulp) and the use of urea as a simple nitrogen source and the second defined more precisely the percentages of coffee pulp and urea to enhance delignification. The responses measured were: lignocellulolytic activities, laccase isoform profiles by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the chemical transformation of the substrate using solid-state NMR of 13C. Adding 10% of coffee pulp increased laccase activities and fungal biomass (32.5% and 16% respectively), enhanced two constitutive isoforms (Rf 0.23 and 0.27), induced a new isoform (Rf 0.19) and led to a decrease in total aromatics. However, higher concentrations of coffee pulp (25%) decreased laccase and cellulase activities but no decrease in aromaticity was observed, potentially due to the toxic effect of phenols from coffee pulp. Moreover, laccase production was still inhibited even for lower concentrations of urea (0-5%). Our findings revealed that an agricultural by-product like coffee pulp can enhance laccase activity -though to a threshold- and that urea limited this process, indicating that other N-sources should be tested for the biological delignification of SCB.
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Celulasa , Celulasas , Pycnoporus , Saccharum , Celulosa , Café , Lacasa , Lignina , UreaRESUMEN
Several interventions have been shown to counteract the effects of stress that may be related to improved neuroplasticity and neuronal activation. In this sense, environmental enrichment (ENR) protects against acute stress and increases neuroplasticity. It has been suggested that the use of patterned auditory stimuli (PAS) may be beneficial in increasing the effectiveness of ENR on disorders related to stress, such as depression and anxiety. Examples of PAS are classical music compositions that have interesting effects at both clinical and preclinical levels. Thus, we analyzed the effects of the exposure to PAS, represented in this study by Mozart's compositions, during ENR housing for 35 days in adult male Balb/C mice to evaluate depression-associated behavior using the forced-swim test (FST) paradigm with an additional short exposure to PAS. We found that the ENR mice that were exposed to PAS during both housing and behavioral task (ENR + PAS/FST + PAS) show decreased immobility and the number of despair episodes within a higher latency to show the first bout of immobility. Additionally, we found increased neuronal activation evaluated by the identification of activity-regulated cytoskeleton-associated protein- (Arc-) labeled cells in the prefrontal cortex (PFC) in mice exposed to PAS during housing and in the absence or presence of PAS during FST. Moreover, we found increased neuronal activation in the auditory cortex (AuCx) of mice exposed to PAS during FST. Our study suggests that the exposure to PAS during an emotional challenge decreases despair-like behavior in rodents that were previously housed in an enriched environment in combination with auditory stimuli. Thus, our data indicate that the role of the exposure to PAS as an intervention or in combination with positive environment to aid in treating neuropsychiatric disorders is worth pursuing.
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Estimulación Acústica/métodos , Depresión , Vivienda para Animales , Estrés Fisiológico/fisiología , Estrés Psicológico/fisiopatología , Animales , Corticosterona/sangre , Ambiente , Masculino , Ratones , Ratones Endogámicos BALB C , Neuronas/fisiología , Estrés Psicológico/psicología , NataciónRESUMEN
Gold nanoparticles (AuNPs) are currently under intense investigation for biomedical and biotechnology applications, thanks to their ease in preparation, stability, biocompatibility, multiple surface functionalities, and size-dependent optical properties. The most commonly used method for AuNP synthesis in aqueous solution is the reduction of tetrachloroauric acid (HAuCl4) with trisodium citrate. We have observed variations in the pH and in the concentration of the gold colloidal suspension synthesized under standard conditions, verifying a reduction in the reaction yield by around 46% from pH 5.3 (2.4 nM) to pH 4.7 (1.29 nM). Citrate-capped AuNPs were characterized by UV-visible spectroscopy, TEM, EDS, and zeta-potential measurements, revealing a linear correlation between pH and the concentration of the generated AuNPs. This result can be attributed to the adverse effect of protons both on citrate oxidation and on citrate adsorption onto the gold surface, which is required to form the stabilization layer. Overall, this study provides insight into the effect of the pH over the synthesis performance of the method, which would be of particular interest from the point of view of large-scale manufacturing processes.
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Four low molecular weight compounds-three of them new, two of them with carbazole (Cz) as functional group and the other two with thienopyrroledione (TPD) group-were used as emitting materials in organic light emitting diodes (OLEDs). Devices were fabricated with the configuration ITO/PEDOT:PSS/emitting material/LiF/Al. The hole injector layer (HIL) and the emitting sheet were deposited by spin coating; LiF and Al were thermally evaporated. OLEDs based on carbazole derivatives show luminances up to 4130 cd/m², large current efficiencies about 20 cd/A and, cautiously, a very impressive External Quantum Efficiency (EQE) up to 9.5%, with electroluminescence peaks located around 490 nm (greenish blue region). Whereas, devices manufactured with TPD derivatives, present luminance up to 1729 cd/m², current efficiencies about 4.5 cd/A and EQE of 1.5%. These results are very competitive regarding previous reported materials/devices.
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Carbazoles/química , Semiconductores , Tienopiridinas/químicaRESUMEN
Since the establishment of perovskite solar cells (PSCs), there has been an intense search for alternative materials to replace lead and improve their stability toward moisture and light. As single-metal perovskite structures have yielded unsatisfactory performances, an alternative is the use of double perovskites that incorporate a combination of metals. To this day, only a handful of these compounds have been synthesized, but most of them have indirect bandgaps and/or do not have bandgaps energies well-suited for photovoltaic applications. Here we report the synthesis and characterization of a unique mixed metal ⟨111⟩-oriented layered perovskite, Cs4CuSb2Cl12 (1), that incorporates Cu2+ and Sb3+ into layers that are three octahedra thick (n = 3). In addition to being made of abundant and nontoxic elements, we show that this material behaves as a semiconductor with a direct bandgap of 1.0 eV and its conductivity is 1 order of magnitude greater than that of MAPbI3 (MA = methylammonium). Furthermore, 1 has high photo- and thermal-stability and is tolerant to humidity. We conclude that 1 is a promising material for photovoltaic applications and represents a new type of layered perovskite structure that incorporates metals in 2+ and 3+ oxidation states, thus significantly widening the possible combinations of metals to replace lead in PSCs.