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1.
Nature ; 585(7824): 225-233, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32908268

RESUMEN

Isoprene is the dominant non-methane organic compound emitted to the atmosphere1-3. It drives ozone and aerosol production, modulates atmospheric oxidation and interacts with the global nitrogen cycle4-8. Isoprene emissions are highly uncertain1,9, as is the nonlinear chemistry coupling isoprene and the hydroxyl radical, OH-its primary sink10-13. Here we present global isoprene measurements taken from space using the Cross-track Infrared Sounder. Together with observations of formaldehyde, an isoprene oxidation product, these measurements provide constraints on isoprene emissions and atmospheric oxidation. We find that the isoprene-formaldehyde relationships measured from space are broadly consistent with the current understanding of isoprene-OH chemistry, with no indication of missing OH recycling at low nitrogen oxide concentrations. We analyse these datasets over four global isoprene hotspots in relation to model predictions, and present a quantification of isoprene emissions based directly on satellite measurements of isoprene itself. A major discrepancy emerges over Amazonia, where current underestimates of natural nitrogen oxide emissions bias modelled OH and hence isoprene. Over southern Africa, we find that a prominent isoprene hotspot is missing from bottom-up predictions. A multi-year analysis sheds light on interannual isoprene variability, and suggests the influence of the El Niño/Southern Oscillation.


Asunto(s)
Atmósfera/química , Butadienos/análisis , Butadienos/química , Mapeo Geográfico , Hemiterpenos/análisis , Hemiterpenos/química , Imágenes Satelitales , África , Australia , Brasil , Conjuntos de Datos como Asunto , El Niño Oscilación del Sur , Formaldehído/química , Radical Hidroxilo/análisis , Radical Hidroxilo/química , Ciclo del Nitrógeno , Óxidos de Nitrógeno/análisis , Óxidos de Nitrógeno/química , Oxidación-Reducción , Estaciones del Año , Sudeste de Estados Unidos
2.
Gene Ther ; 31(1-2): 31-44, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37542151

RESUMEN

Parkinson`s disease (PD) is the second most prevalent neurodegenerative disease, and different gene therapy strategies have been used as experimental treatments. As a proof-of-concept for the treatment of PD, we used SAM, a CRISPR gene activation system, to activate the endogenous tyrosine hydroxylase gene (th) of astrocytes to produce dopamine (DA) in the striatum of 6-OHDA-lesioned rats. Potential sgRNAs within the rat th promoter region were tested, and the expression of the Th protein was determined in the C6 glial cell line. Employing pseudo-lentivirus, the SAM complex and the selected sgRNA were transferred into cultures of rat astrocytes, and gene expression and Th protein synthesis were ascertained; furthermore, DA release into the culture medium was determined by HPLC. The DA-producing astrocytes were implanted into the striatum of 6-OHDA hemiparkinsonian rats. We observed motor behavior improvement in the lesioned rats that received DA-astrocytes compared to lesioned rats receiving astrocytes that did not produce DA. Our data indicate that the SAM-induced expression of the astrocyte´s endogenous th gene can generate DA-producing astrocytes that effectively reduce the motor asymmetry induced by the lesion.


Asunto(s)
Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Ratas , Animales , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/terapia , Enfermedad de Parkinson/metabolismo , ARN Guía de Sistemas CRISPR-Cas , Oxidopamina , Ratas Sprague-Dawley , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Dopamina/metabolismo , Cuerpo Estriado/metabolismo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/metabolismo , Tirosina 3-Monooxigenasa/farmacología , Sustancia Negra/metabolismo
3.
Eur J Neurosci ; 59(7): 1441-1459, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38151481

RESUMEN

Dopamine D2 receptor (D2R) is expressed in striatopallidal neurons and decreases forskolin-stimulated cyclic adenine monophosphate (cAMP) accumulation and gamma-aminobutyric acid (GABA) release. Dopamine D3 receptor (D3R) mRNA is expressed in a population of striatal D2R-expressing neurons. Also, D3R protein and binding have been reported in the neuropil of globus pallidus. We explore whether D2R and D3R colocalize in striatopallidal terminals and whether D3R modulates the D2R effect on forskolin-stimulated [3H]cAMP accumulation in pallidal synaptosomes and high K+ stimulated-[3H]GABA release in pallidal slices. Previous reports in heterologous systems indicate that calmodulin (CaM) and CaMKII modulate D2R and D3R functions; thus, we study whether this system regulates its functional interaction. D2R immunoprecipitates with CaM, and pretreatment with ophiobolin A or depolarization of synaptosomes with 15 mM of K+ decreases it. Both treatments increase the D2R inhibition of forskolin-stimulated [3H]cAMP accumulation when activated with quinpirole, indicating a negative modulation of CaM on D2R function. Quinpirole also activates D3R, potentiating D2R inhibition of cAMP accumulation in the ophiobolin A-treated synaptosomes. D2R and D3R immunoprecipitate in pallidal synaptosomes and decrease after the kainic acid striatal lesion, indicating the striatal origin of the presynaptic receptors. CaM-kinase II alfa (CaMKIIα) immunoprecipitates with D3R and increases after high K+ depolarization. In the presence of KN62, a CaMKIIα blocker, D3R potentiates D2R effects on cAMP accumulation in depolarized synaptosomes and GABA release in pallidal slices, indicating D3R function regulation by CaMKIIα. Our data indicate that D3R potentiates the D2R effect on cAMP accumulation and GABA release at pallidal terminals, an interaction regulated by the CaM-CaMKIIα system.


Asunto(s)
Calmodulina , Receptores de Dopamina D3 , Sesterterpenos , Receptores de Dopamina D3/metabolismo , Quinpirol/farmacología , Calmodulina/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Colforsina , Receptores de Dopamina D2/metabolismo , Ácido gamma-Aminobutírico/metabolismo
4.
Molecules ; 29(4)2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38398597

RESUMEN

Phospholane-phosphites are known to show highly unusual selectivity towards branched aldehydes in the hydroformylation of terminal alkenes. This paper describes the synthesis of hitherto unknown unsaturated phospholene borane precursors and their conversion to the corresponding phospholene-phosphites. The relative stereochemistry of one of these ligands and its Pd complex was assigned with the aid of X-ray crystal structure determinations. These ligands were able to approach the level of selectivity observed for phospholane-phosphites in the rhodium-catalysed hydroformylation of propene. High-pressure infra-red (HPIR) spectroscopic monitoring of the catalyst formation revealed that whilst the catalysts showed good thermal stability with respect to fragmentation, the C=C bond in the phospholene moiety was slowly hydrogenated in the presence of rhodium and syngas. The ability of this spectroscopic tool to detect even subtle changes in structure, remotely from the carbonyl ligands, underlines the usefulness of HPIR spectroscopy in hydroformylation catalyst development.

5.
Cell Biol Toxicol ; 39(3): 751-770, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-34448959

RESUMEN

Autophagy is a conserved intracellular catabolic pathway that removes cytoplasmic components to contribute to neuronal homeostasis. Accumulating evidence has increasingly shown that the induction of autophagy improves neuronal health and extends longevity in several animal models. Therefore, there is a great interest in the identification of effective autophagy enhancers with potential nutraceutical or pharmaceutical properties to ameliorate age-related diseases, such as neurodegenerative disorders, and/or promote longevity. Queen bee acid (QBA, 10-hydroxy-2-decenoic acid) is the major fatty acid component of, and is found exclusively in, royal jelly, which has beneficial properties for human health. It is reported that QBA has antitumor, anti-inflammatory, and antibacterial activities and promotes neurogenesis and neuronal health; however, the mechanism by which QBA exerts these effects has not been fully elucidated. The present study investigated the role of the autophagic process in the protective effect of QBA. We found that QBA is a novel autophagy inducer that triggers autophagy in various neuronal cell lines and mouse and fly models. The beclin-1 (BECN1) and mTOR pathways participate in the regulation of QBA-induced autophagy. Moreover, our results showed that QBA stimulates sirtuin 1 (SIRT1), which promotes autophagy by the deacetylation of critical ATG proteins. Finally, QBA-mediated autophagy promotes neuroprotection in Parkinson's disease in vitro and in a mouse model and extends the lifespan of Drosophila melanogaster. This study provides detailed evidences showing that autophagy induction plays a critical role in the beneficial health effects of QBA.


Asunto(s)
Fármacos Neuroprotectores , Enfermedad de Parkinson , Ratones , Humanos , Abejas , Animales , Neuroprotección , Drosophila melanogaster , Autofagia , Línea Celular , Fármacos Neuroprotectores/farmacología
6.
BMC Cancer ; 22(1): 1150, 2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36348385

RESUMEN

BACKGROUND: Rucaparib is a poly(ADP-ribose) polymerase inhibitor approved in Europe as maintenance therapy for recurrent platinum-sensitive (Pt-S) ovarian cancer (OC). The Rucaparib Access Programme (RAP) was designed to provide early access to rucaparib for the above-mentioned indication, as well as for patients with BRCA-mutated Pt-S or platinum-resistant (Pt-R) OC and no therapeutic alternatives. METHODS: In this observational, retrospective study we analysed the efficacy and safety of rucaparib within the RAP in Spain. Hospitals associated with the Spanish Ovarian Cancer Research Group (GEICO) recruited patients with high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer treated with rucaparib 600 mg twice daily as maintenance or treatment (Pt-S/Pt-R) in the RAP. Baseline characteristics, efficacy, and safety data were collected. RESULTS: Between July 2020 and February 2021, 51 patients treated in 22 hospitals in the RAP were included in the study. Eighteen patients with a median of 3 (range, 1-6) prior treatment lines received rucaparib as maintenance; median progression-free survival (PFS) for this group was 9.1 months (95% confidence interval [CI], 4.2-11.6 months). Among 33 patients (median 5 [range, 1-9] prior treatment lines) who received rucaparib as treatment, 7 and 26 patients had Pt-S and Pt-R disease, respectively. Median PFS was 10.6 months (95% CI, 2.5 months-not reached) in the Pt-S group and 2.2 months (95% CI, 1.1-3.2 months) in the Pt-R group. Grade ≥ 3 treatment-emergent adverse events were reported in 39% of all patients, the most common being anaemia (12% and 15% in the maintenance and treatment groups, respectively). At data cut-off, 5 patients remained on treatment. CONCLUSION: Efficacy results in these heavily pre-treated patients were similar to those from previous trials. The safety profile of rucaparib in real life was predictable and manageable.


Asunto(s)
Antineoplásicos , Neoplasias Ováricas , Humanos , Femenino , España , Neoplasias Ováricas/tratamiento farmacológico , Estudios Retrospectivos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Carcinoma Epitelial de Ovario/tratamiento farmacológico , Inhibidores de Poli(ADP-Ribosa) Polimerasas/efectos adversos , Antineoplásicos/uso terapéutico
7.
Synapse ; 76(11-12): e22246, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35831708

RESUMEN

Striatal medium-sized spiny neurons express mRNA and protein of GPR55 receptors that stimulate neurotransmitter release; thus, GPR55 could be sent to nigral striatal projections, where it might modulate GABA release and motor behavior. Here, we study the presence of GPR55 receptors at striato-nigral terminals, their modulation of GABA release, their signaling pathway, and their effect on motor activity. By double immunohistochemistry, we found the colocation of GPR55 protein and substance P in the dorsal striatum. In slices of the rat substantia nigra, the GPR55 agonists LPI and O-1602 stimulated [3 H]-GABA release induced by high K+ depolarization in a dose-dependent manner. The antagonists CID16020046 and cannabidiol prevented agonist stimulation in a dose-dependent way. The effect of GPR55 on nigral [3 H]-GABA release was prevented by lesion of the striatum with kainic acid, which was accompanied by a decrement of GPR55 protein in nigral synaptosomes, indicating the presynaptic location of receptors. The depletion of internal Ca2+ stores with thapsigargin did not prevent the effect of LPI on [3 H]-GABA release, but the remotion or chelation of external calcium did. Blockade of Gi, Gs, PLC, PKC, or dopamine D1 receptor signaling proteins did not prevent the effect of GPR55 on release. However, the activation of GPR55 stimulated [3 H]-cAMP accumulation and PKA activity. Intranigral unilateral injection of LPI induces contralateral turning. This turning was prevented by CID16020046, cannabidiol, and bicuculline but not by SCH 23390. Our data indicate that presynaptic GPR55 receptors stimulate [3 H]-GABA release at striato-nigral terminals through [3 H]-cAMP production and stimulate motor behavior.


Asunto(s)
Cannabidiol , Receptores de Cannabinoides , Receptores Acoplados a Proteínas G , Receptores Presinapticos , Animales , Compuestos de Azabiciclo , Benzoatos , Bicuculina/farmacología , Calcio/metabolismo , Cannabidiol/metabolismo , Cannabidiol/farmacología , Ácido Kaínico/metabolismo , Ácido Kaínico/farmacología , Neurotransmisores/farmacología , ARN Mensajero/metabolismo , Ratas , Receptores de Cannabinoides/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Presinapticos/metabolismo , Sustancia P/metabolismo , Sustancia Negra/metabolismo , Tapsigargina/metabolismo , Tapsigargina/farmacología , Ácido gamma-Aminobutírico/metabolismo
8.
Gynecol Oncol ; 166(1): 36-43, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35550709

RESUMEN

OBJECTIVE: To evaluate the association between surgical timing and postoperative residual disease status on the efficacy of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer at high risk of recurrence. METHODS: Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) study of niraparib in patients with newly diagnosed primary advanced ovarian, primary peritoneal, or fallopian tube cancer with a complete/partial response to first-line platinum-based chemotherapy. Progression-free survival (PFS) was assessed by surgical status (primary debulking surgery [PDS] vs neoadjuvant chemotherapy/interval debulking surgery [NACT/IDS]) and postoperative residual disease status (no visible residual disease [NVRD] vs visible residual disease [VRD]) in the intent-to-treat population. RESULTS: In PRIMA (N = 733), 236 (32.2%) patients underwent PDS, and 481 (65.6%) received NACT/IDS before enrollment. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) for progression were similar in PDS (13.7 vs 8.2 months; HR, 0.67 [0.47-0.96]) and NACT/IDS (14.2 vs 8.2 months; HR, 0.57 [0.44-0.73]) subgroups. In patients who received NACT/IDS and had NVRD (n = 304), the hazard ratio (95% CI) for progression was 0.65 (0.46-0.91). In patients with VRD following PDS (n = 183) or NACT/IDS (n = 149), the hazard ratios (95% CI) for progression were 0.58 (0.39-0.86) and 0.41 (0.27-0.62), respectively. PFS was not evaluable for patients with PDS and NVRD because of sample size (n = 37). CONCLUSIONS: In this post hoc analysis, niraparib efficacy was similar across PDS and NACT/IDS subgroups. Patients who had NACT/IDS and VRD had the highest reduction in the risk of progression with niraparib maintenance.


Asunto(s)
Neoplasias Ováricas , Carcinoma Epitelial de Ovario/tratamiento farmacológico , Carcinoma Epitelial de Ovario/cirugía , Quimioterapia Adyuvante , Procedimientos Quirúrgicos de Citorreducción , Femenino , Humanos , Indazoles/uso terapéutico , Terapia Neoadyuvante , Estadificación de Neoplasias , Neoplasia Residual , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Neoplasias Ováricas/cirugía , Piperidinas
9.
Cell Biol Toxicol ; 38(5): 889-911, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34060004

RESUMEN

Autophagy is a mechanism responsible for the degradation of cellular components to maintain their homeostasis. However, autophagy is commonly altered and compromised in several diseases, including neurodegenerative disorders. Parkinson's disease (PD) can be considered a multifactorial disease because environmental factors, genetic factors, and aging are involved. Several genes are involved in PD pathology, among which the LRRK2 gene and its mutations, inherited in an autosomal dominant manner, are responsible for most genetic PD cases. The R1441G LRRK2 mutation is, after G2019S, the most important in PD pathogenesis. Our results demonstrate a relationship between the R1441G LRRK2 mutation and a mechanistic dysregulation of autophagy that compromises cell viability. This altered autophagy mechanism is associated with organellar stress including mitochondrial (which induces mitophagy) and endoplasmic reticulum (ER) stress, consistent with the fact that patients with this mutation are more vulnerable to toxins related to PD, such as MPP+.


Asunto(s)
Mitofagia , Enfermedad de Parkinson , Estrés del Retículo Endoplásmico/genética , Humanos , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/metabolismo , Macroautofagia , Mitofagia/genética , Mutación/genética , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Proteínas Serina-Treonina Quinasas/genética
10.
J Nanobiotechnology ; 20(1): 413, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109747

RESUMEN

Parkinson's disease (PD) significantly affects patients' quality of life and represents a high economic burden for health systems. Given the lack of safe and effective treatments for PD, drug repositioning seeks to offer new medication alternatives, reducing research time and costs compared to the traditional drug development strategy. This review aimed to collect evidence of drugs proposed as candidates to be reused in PD and identify those with the potential to be reformulated into nanocarriers to optimize future repositioning trials. We conducted a detailed search in PubMed, Web of Science, and Scopus from January 2015 at the end of 2021, with the descriptors "Parkinson's disease" and "drug repositioning" or "drug repurposing". We identified 28 drugs as potential candidates, and six of them were found in repositioning clinical trials for PD. However, a limitation of many of these drugs to achieve therapeutic success is their inability to cross the blood-brain barrier (BBB), as is the case with nilotinib, which has shown promising outcomes in clinical trials. We suggest reformulating these drugs in biodegradable nanoparticles (NPs) based on lipids and polymers to perform future trials. As a complementary strategy, we propose functionalizing the NPs surface by adding materials to the surface layer. Among other advantages, functionalization can promote efficient crossing through the BBB and improve the affinity of NPs towards certain brain regions. The main parameters to consider for the design of NPs targeting the central nervous system are highlighted, such as size, PDI, morphology, drug load, and Z potential. Finally, current advances in the use of NPs for Parkinson's disease are cited.


Asunto(s)
Enfermedad de Parkinson , Reposicionamiento de Medicamentos , Humanos , Lípidos , Nanotecnología , Enfermedad de Parkinson/tratamiento farmacológico , Preparaciones Farmacéuticas , Polímeros/uso terapéutico , Calidad de Vida
11.
Gac Med Mex ; 157(1): 107-109, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34125803

RESUMEN

INTRODUCTION: Clostridioides difficile causes diarrhea and pseudomembranous colitis. Its diagnosis is made with glutamate dehydrogenase (GDH) or toxins A and B detection and is confirmed with nucleic acid amplification tests. OBJECTIVE: To define if GDH determination is redundant to that of toxins. METHODS: Retrospective, observational study in diarrheal stools of patients with suspected Clostridioides difficile infection. Toxins and GDH were determined by immunochromatography. Bayesian simulation was performed with likelihood ratios; a p-value < 0.05 was regarded as significant. RESULTS: 329 GDH and toxin A and B results were analyzed. Clostridioides difficile infection prevalence was 18.2 %. Sensitivity and specificity of the GDH test were 0.90 and 0.89, respectively. Positive likelihood ratio was 8.9, and negative was 0.11. CONCLUSIONS: A negative GDH result considerably reduces the probability of infection but does not rule it out. Clostridioides difficile toxins detection may be necessary in institutions where nucleic acid amplification is not affordable or accessible.


INTRODUCCIÓN: Clostridioides difficile causa diarrea y colitis pseudomembranosa. Su diagnóstico se realiza con la detección de glutamato-deshidrogenasa (GDH) o las toxinas A y B y se confirma con pruebas de amplificación de ácidos nucleicos. OBJETIVO: Definir si la determinación de GDH es redundante a la de las toxinas. MÉTODOS: Estudio observacional retrospectivo de muestras fecales de pacientes con sospecha de infección por Clostridioides difficile. Las toxinas y GDH se determinaron mediante inmunocromatografía. Se realizó una simulación bayesiana con los cocientes de probabilidad; se consideró significativo un valor de p < 0.05. RESULTADOS: Se analizaron 329 resultados de GDH y toxinas A y B. Se encontró una prevalencia de infección de Clostridioides difficile de 18.2 %. La sensibilidad y especificidad de la prueba de GDH fue de 0.90 y 0.89, respectivamente. El cociente de probabilidad positivo fue de 8.9 y el negativo, de 0.11. CONCLUSIONES: Un resultado negativo de GDH disminuye considerablemente la probabilidad de infección, pero no la descarta. La detección de toxinas de Clostridioides difficile puede ser necesaria en instituciones donde la amplificación de ácidos nucleicos no es económica o accesible.


Asunto(s)
Proteínas Bacterianas/análisis , Toxinas Bacterianas/análisis , Clostridioides difficile , Infecciones por Clostridium/diagnóstico , Enterotoxinas/análisis , Heces/química , Glutamato Deshidrogenasa/análisis , Adulto , Anciano , Teorema de Bayes , Biomarcadores/análisis , Infecciones por Clostridium/epidemiología , Diarrea/microbiología , Heces/enzimología , Femenino , Humanos , Funciones de Verosimilitud , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Sensibilidad y Especificidad
12.
Eur J Neurosci ; 52(11): 4563-4585, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33098606

RESUMEN

Two major groups of terminals release GABA within the Globus pallidus; one group is constituted by projections from striatal neurons, while endings of the intranuclear collaterals form the other one. Each neurons' population expresses different subtypes of dopamine D2-like receptors: D2 R subtype is expressed by encephalin-positive MSNs, while pallidal neurons express the D4 R subtype. The D2 R modulates the firing rate of striatal neurons and GABA release at their projection areas, while the D4 R regulates Globus pallidus neurons excitability and GABA release at their projection areas. However, it is unknown if these receptors control GABA release at pallido-pallidal collaterals and regulate motor behavior. Here, we present neurochemical evidence of protein content and binding of D4 R in pallidal synaptosomes, control of [3 H] GABA release in pallidal slices of rat, electrophysiological evidence of the presence of D4 R on pallidal recurrent collaterals in mouse slices, and turning behavior induced by D4 R antagonist microinjected in amphetamine challenged rats. As in projection areas of pallidal neurons, GABAergic transmission in pallido-pallidal recurrent synapses is under modulation of D4 R, while the D2 R subtype, as known, modulates striato-pallidal projections. Also, as in projection areas, D4 R contributes to control the motor activity differently than D2 R. This study could help to understand the organization of intra-pallidal circuitry.


Asunto(s)
Globo Pálido , Receptores de Dopamina D4 , Animales , Cuerpo Estriado/metabolismo , Dopamina , Globo Pálido/metabolismo , Ratones , Ratas , Receptores de Dopamina D1/metabolismo
13.
Sensors (Basel) ; 21(1)2020 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-33375710

RESUMEN

Ensuring the confidentiality of private data stored in our technological devices is a fundamental aspect for protecting our personal and professional information. Authentication procedures are among the main methods used to achieve this protection and, typically, are implemented only when accessing the device. Nevertheless, in many occasions it is necessary to carry out user authentication in a continuous manner to guarantee an allowed use of the device while protecting authentication data. In this work, we first review the state of the art of Continuous Authentication (CA), User Profiling (UP), and related biometric databases. Secondly, we summarize the privacy-preserving methods employed to protect the security of sensor-based data used to conduct user authentication, and some practical examples of their utilization. The analysis of the literature of these topics reveals the importance of sensor-based data to protect personal and professional information, as well as the need for exploring a combination of more biometric features with privacy-preserving approaches.


Asunto(s)
Privacidad , Telemedicina , Biometría , Seguridad Computacional , Confidencialidad
14.
Molecules ; 25(6)2020 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-32178255

RESUMEN

Benefits of nanotechnology in agriculture include reduced fertilizer loss, improved seed germination rate and increased crops quality and yield. The objective of this research was to evaluate the effects of zinc oxide nanoparticles (ZnO-NPs), at 1500 ppm, on tomato (Solanum lycopersicum L.) growth. ZnO-NPs were synthetized to produce either spherical or hexagonal morphologies. In this research, we also studied two application methods (foliar and drench) and nanoparticles' (NPs) surface modification with maltodextrin. The results obtained indicate that ZnO-NP-treated tomato plants significantly increased plant height, stem diameter and plant organs (leaves, stem and root) dry weight compared to plants without NP treatment.


Asunto(s)
Biomasa , Nanopartículas del Metal/química , Solanum lycopersicum/crecimiento & desarrollo , Óxido de Zinc/farmacología , Fertilizantes , Solanum lycopersicum/química , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Propiedades de Superficie/efectos de los fármacos , Óxido de Zinc/química
16.
Opt Express ; 27(9): 12399-12413, 2019 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-31052780

RESUMEN

A method to simultaneously control aberrations and the aperture of an optical system using a single phase-only spatial light modulator was investigated. The experiment was performed using a liquid-crystal-on-silicon spatial light modulator (LCoS-SLM) within an adaptive optics system used for visual testing, although the method has broader applications in adaptive optics field. The performance of the technique was characterized through the estimation of the system's modulation transfer functions (MTFs) by using a random chart method. MTFs obtained from the phase modulation-based approach were compared with those from using a real aperture (diaphragm). The areas under the MTFs for the two conditions were similar up to 98%, confirming that the low-pass filter effect associated to the size of the entrance pupil was similar for the phase-modulated pupil and the physical pupil. As an example of application, both aberrations and pupil were controlled by a single phase-only modulator to study the through-focus visual performance in real subjects. Limitations and possible enhancements of the presented method were also discussed. The presented technique reduces complexity and cost of adaptive optics systems. It opens the door to new experiments by allowing dynamic modulation of aberrations and apertures of any shape.

17.
Environ Sci Technol ; 53(14): 8057-8067, 2019 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-31184868

RESUMEN

Atomic chlorine (Cl) is a strong atmospheric oxidant that shortens the lifetimes of pollutants and methane in the springtime Arctic, where the molecular halogens Cl2 and BrCl are known Cl precursors. Here, we quantify the contributions of reactive chlorine trace gases and present the first observations, to our knowledge, of ClNO2 (another Cl precursor), N2O5, and HO2NO2 in the Arctic. During March - May 2016 near Utqiagvik, Alaska, up to 21 ppt of ClNO2, 154 ppt of Cl2, 27 ppt of ClO, 71 ppt of N2O5, 21 ppt of BrCl, and 153 ppt of HO2NO2 were measured using chemical ionization mass spectrometry. The main Cl precursor was calculated to be Cl2 (up to 73%) in March, while BrCl was a greater contributor (63%) in May, when total Cl production was lower. Elevated levels of ClNO2, N2O5, Cl2, and HO2NO2 coincided with pollution influence from the nearby town of Utqiagvik and the North Slope of Alaska (Prudhoe Bay) Oilfields. We propose a coupled mechanism linking NOx with Arctic chlorine chemistry. Enhanced Cl2 was likely the result of the multiphase reaction of Cl-(aq) with ClONO2, formed from the reaction of ClO and NO2. In addition to this NOx-enhanced chlorine chemistry, Cl2 and BrCl were observed under clean Arctic conditions from snowpack photochemical production. These connections between NOx and chlorine chemistry, and the role of snowpack recycling, are important given increasing shipping and fossil fuel extraction predicted to accompany Arctic sea ice loss.


Asunto(s)
Cloro , Óxidos de Nitrógeno , Alaska , Regiones Árticas , Halógenos
19.
Angew Chem Int Ed Engl ; 58(7): 2120-2124, 2019 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-30561885

RESUMEN

The hydroformylation of propene to give predominantly iso-butanal has been achieved; class-leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos-biphenols and unusual solvent systems are the key to the selectivity observed.

20.
J Cell Physiol ; 234(1): 692-708, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-30132846

RESUMEN

Sorafenib is the unique accepted molecular targeted drug for the treatment of patients in advanced stage of hepatocellular carcinoma. The current study evaluated cell signaling regulation of endoplasmic reticulum (ER) stress, c-Jun-N-terminal kinase (JNK), Akt, and 5'AMP-activated protein kinase (AMPK) leading to autophagy and apoptosis induced by sorafenib. Sorafenib induced early (3-12 hr) ER stress characterized by an increase of Ser51 P-eIF2α/eIF2α, C/EBP homologous protein (CHOP), IRE1α, and sXBP1, but a decrease of activating transcription factor 6 expression, overall temporally associated with the increase of Thr183,Tyr185 P-JNK1/2/JNK1/2, Thr172 P-AMPKα, Ser413 P-Foxo3a, Thr308 P-AKt/AKt and Thr32 P-Foxo3a/Foxo3a ratios, and reduction of Ser2481 P-mammalian target of rapamycin (mTOR)/mTOR and protein translation. This pattern was related to a transient increase of tBid, Bim EL , Beclin-1, Bcl-xL, Bcl-2, autophagy markers, and reduction of myeloid cell leukemia-1 (Mcl-1) expression. The progressive increase of CHOP expression, and reduction of Thr308 P-AKt/AKt and Ser473 P-AKt/AKt ratios were associated with the reduction of autophagic flux and an additional upregulation of Bim EL expression and caspase-3 activity (24 hr). Small interfering-RNA (si-RNA) assays showed that Bim, but not Bak and Bax, was involved in the induction of caspase-3 in sorafenib-treated HepG2 cells. Sorafenib increased autophagic and apoptotic markers in tumor-derived xenograft model. In conclusion, the early sorafenib-induced ER stress and regulation of JNK and AMPK-dependent signaling were related to the induction of survival autophagic process. The sustained drug treatment induced a progressive increase of ER stress and PERK-CHOP-dependent rise of Bim EL , which was associated with the shift from autophagy to apoptosis. The kinetic of Bim EL expression profile might also be related to the tight balance between AKt- and AMPK-related signaling leading to Foxo3a-dependent BIM EL upregulation.


Asunto(s)
Estrés del Retículo Endoplásmico/genética , Neoplasias Hepáticas/tratamiento farmacológico , Proteínas de Neoplasias/genética , Sorafenib/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Autofagia/efectos de los fármacos , Autofagia/genética , Biomarcadores de Tumor/genética , Caspasa 3/genética , Regulación Neoplásica de la Expresión Génica , Células Hep G2 , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Ratones , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Transducción de Señal/efectos de los fármacos , Factor de Transcripción CHOP/genética , Ensayos Antitumor por Modelo de Xenoinjerto
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