In this work, the adsorption of a type of cruciform system integrated by an anthracene central part and two side chains with a pyridine‐vinyl structure (DPAC) was studied on plasmonic nanoparticles ...of silver and gold. The adsorption was investigated by surface‐enhanced Raman scattering, which reveals very valuable information about both the interaction mechanism and the molecular orientation. The highest Raman enhancement was measured on Ag nanostars due to the combination of gaps and tips in these nanostructures. The changes observed in the surface‐enhanced Raman scattering spectra indicate that the adsorption of DPAC on the metal is bifunctional in the case of Ag and Au nanoparticles. Considering that the Raman signals enhancement is several orders of magnitude higher in gaps in relation to regions out of these areas, it is estimated that the enhancement ability of DPAC in Ag nanostars is so high that it allows the detection of a concentration close to pM.
In this work, we study the adsorption of a type of cruciform system integrated by an anthracene central part and two side chains with a pyridine‐vinyl structure (DPAC) on plasmonic nanoparticles of silver and gold by SERS. The highest Raman enhancement was measured on Ag nanostars due to the combination of gaps and tips in these nanostructures. SERS spectra indicate that the adsorption of DPAC on the metal is bifunctional in the case of Ag and Au nanoparticles.
Silver nanoparticles (AgNPs) were synthetized and employed in surface-enhanced Raman scattering measurements to study the chemical behavior when thiacloprid (Thia) interacts with the surface of Ag ...nanospheres (AgNSp) and Ag nanostars (AgNSt) upon excitation of the system with a 785 nm laser. Experimental results show that the deactivation of the localized surface plasmon resonance induces structural changes in Thia. When AgNSp are used, it is possible to observe a mesomeric effect in the cyanamide moiety. On the other hand, when AgNSt are employed, it promotes the cleavage of the methylene (−CH2−) bridge in Thia to produce two molecular fragments. To support these results, theoretical calculations based on topological parameters described by the atoms in molecules theory, Laplacian of the electron density at the bond critical point (∇2ρ BCP), Laplacian bond order, and bond dissociation energies were made, confirming that the bond cleavage is centered at the −CH2– bridge in Thia.
A feasibility study of the synthesis of gel polymer electrolytes based in methyl methacrylate (MMA) and 1-vinyl-2-pyrrolidone (VP) using HEMImBF
4
as common ionic liquid has been done. A novel ...PVP/HEMImBF
4
solid-state and self-standing ion gel electrolyte has been successfully prepared. The thermal degradation of PVP/HEMImBF
4
ion gel occurs in two steps with the first one at above 200 °C and the main one over 390 °C. This solid-state ion gel is transparent, showing an optical transmittance with a maximum value of 90% in the visible wavelength region from 370 to 770 nm. The synthesized PVP/HEMImBF
4
solid-state ion gel exhibits an electrochemical stability window of ca. 5.0 V and an acceptable ionic conductivity of
σ
= 5.7 10
−3
S cm
−1
at room temperature. A symmetrical pseudocapacitive supercapacitor has been assembled and characterized using this PVP/HEMImBF
4
solid-state ion gel—glass/ITO/PEDOT/PVP/HEMImBF
4
/PEDOT/ITO/glass. It is found that the supercapacitor shows a typical areal specific capacitance of 3.1 mF cm
−2
, a maximum energy density of 2.5 μWh cm
−2
, and an areal specific power density of ca. 1 mW cm
−2
.
Graphical abstract
Squeme and cyclic voltammogram curves of the tested supercapacitor device
Blood transfusion is a lifesaving treatment for hemorrhagic shock. During storage, red blood cells (RBC) undergo progressive deleterious functional, biochemical and structural alterations, which are ...collectively termed the “storage lesion”. The association between transfusion of blood stored for more than 14 days and adverse clinical outcomes (increased infection, multi-organ failure and mortality) is controversial. Studying mice with hemorrhagic shock, we recently found that resuscitation with blood stored for prolonged periods (SRBC) was associated with worse outcomes than was resuscitation with fresh blood (FRBC). The mechanisms responsible for the adverse effects associated with transfusion of SRBC are incompletely characterized. However, it is known that transfusion of SRBC increases plasma levels of hemoglobin (Hb), which can scavenge vascular nitric oxide (NO). Intravenous infusion of a solution containing cell-free Hb induces systemic hypertension in wild-type (WT) mice, but not in mice that are congenitally deficient in NO synthase 3 (NOS3-/-). In the present study, we sought to determine if NOS3-/- mice are protected from the adverse effects associated with resuscitation of hemorrhagic shock with SRBC.
Leukoreduced, packed RBC from WT C57BL6 mice were stored with 14% CPDA-1 anticoagulant at 4°C for either ≤24 h (FRBC) or 2 weeks (SRBC). Mice, of each genotype that were not subjected to hemorrhagic shock or resuscitation, served as control groups. Anesthetized WT mice and NOS3-/- mice (on a C57BL6 background) were bled to a mean arterial pressure (MAP) of 40 mmHg over 10 min. After 90 min of hemorrhagic shock, mice were resuscitated with FRBC or SRBC. Survival rates for up to 7 days were determined. In addition, blood and tissue samples were collected at 4 h after resuscitation to measure plasma markers of liver and kidney injury, plasma Hb and interleukin 6 (IL-6) levels, tissue IL-6 mRNA levels, and pulmonary myeloperoxidase activity and mRNA levels. All data are expressed as mean±SD.
Baseline MAP under anesthesia was higher in NOS3-/- mice than in WT mice (111±4 vs 83±5 mmHg; P<0.01). After hemorrhagic shock and resuscitation with either FRBC or SRBC, MAP returned to the respective baseline values in each genotype. Survival rates at one week did not differ between WT or NOS3-/- mice resuscitated with either FRBC or SRBC. In both genotypes, after hemorrhagic shock, resuscitation with FRBC elevated plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities similarly as compared to a control group (P<0.01). Plasma levels of ALT and AST were greater after resuscitation with SRBC than after resuscitation with FRBC in both genotypes at 4 h (P<0.01). Resuscitation with SRBC, but not FRBC, increased plasma blood urea nitrogen and creatinine levels similarly in WT and NOS3-/- mice. Plasma Hb levels were greater in mice resuscitated with SRBC than in those resuscitated with FRBC in both genotypes at 4 h after resuscitation (WT: 202±79 vs 5±2 µM, respectively; NOS3-/-: 240±51 vs 14±3 µM, respectively; P<0.001 for both). At 4 h after resuscitation, plasma IL-6 levels were greater in mice treated with SRBC than in mice treated with FRBC in both genotypes (WT: 0.8±0.1 vs 0.5±0.1 ng/ml, respectively; NOS3-/-: 0.8±0.1 vs 0.4±0.1 ng/ml; P<0.01 for both). In both WT and NOS3-/- mice, IL-6 mRNA levels were greater in the liver, kidney, and spleen after resuscitation with SRBC than after resuscitation with FRBC (P<0.01, all values differ SRBC vs FRBC for both genotypes). Pulmonary myeloperoxidase activity and mRNA levels were greater in both genotypes after resuscitation with SRBC than mice resuscitated with FRBC (P<0.01, all values differ SRBC vs FRBC for both genotypes).
Survival rate after hemorrhagic shock did not differ in WT and NOS3-/- mice resuscitated with either FRBC or SRBC. Resuscitation with SRBC induced greater tissue injury and a more marked inflammatory response than did resuscitation with FRBC, but there was no difference between the genotypes. Our data suggest that mice with NOS3 deficiency are not protected from the adverse effects associated with resuscitation of hemorrhagic shock with SRBC. These findings suggest that the adverse effects of transfusing blood stored for prolonged periods in mice with hemorrhagic shock are not exclusively attributable to scavenging of NOS3-generated NO by increased plasma Hb levels.
No relevant conflicts of interest to declare.
Remodeling of the pulmonary arteries is a common feature among the heterogeneous disorders that cause pulmonary hypertension. In these disorders, the remodeled pulmonary arteries often demonstrate ...inflammation and an accumulation of pulmonary artery smooth muscle cells (PASMCs) within the vessels. Adipose tissue secretes multiple bioactive mediators (adipokines) that can influence both inflammation and remodeling, suggesting that adipokines may contribute to the development of pulmonary hypertension. We recently reported on a model of pulmonary hypertension induced by vascular inflammation, in which a deficiency of the adipokine adiponectin (APN) was associated with the extensive proliferation of PASMCs and increased pulmonary artery pressures. Based on these data, we hypothesize that APN can suppress pulmonary hypertension by directly inhibiting the proliferation of PASMCs. Here, we tested the effects of APN overexpression on pulmonary arterial remodeling by using APN-overexpressing mice in a model of pulmonary hypertension induced by inflammation. Consistent with our hypothesis, mice that overexpressed APN manfiested reduced pulmonary hypertension and remodeling compared with wild-type mice, despite developing similar levels of pulmonary vascular inflammation in the model. The overexpression of APN was also protective in a hypoxic model of pulmonary hypertension. Furthermore, APN suppressed the proliferation of PASMCs, and reduced the activity of the serum response factor-serum response element pathway, which is a critical signaling pathway for smooth muscle cell proliferation. Overall, these data suggest that APN can regulate pulmonary hypertension and pulmonary arterial remodeling through its direct effects on PASMCs. Hence, the activation of APN-like activity in the pulmonary vasculature may be beneficial in pulmonary hypertension.
Aquí se presentan los resultados de los análisis de espectroscopía Raman e Infrarroja de pigmentos rojos provenientes de dos contextos fúnebres del cementerio de Topater-1, además de otras dos ...muestras, una del sector San Salvador y otra sin referencia como muestra de control. Todos los pigmentos fueron hallados en el área de Calama, norte de Chile (ca. 500 AC – 100 DC). El cromóforo rojo identificado en todos los casos fue hematita, además de distintos tipos de arcilla y cantidades variables de materia orgánica. Los contenidos de arcillas se relacionan con diversas fuentes de aprovisionamiento, mientras que la presencia de materia orgánica sugiere procesos tecnológicos. Luego, el contraste de estos resultados con la evidencia arqueológica local permite explorar prácticas tecnológicas donde es importante la relación individuo-paisaje o medio ambiente. Esta evidencia es significativa porque confluye con prácticas fúnebres donde se depositan estos pigmentos en valvas de Concholepas concholepas. La realización en la región de estudios de largo alcance bajo esta óptica permitiría: i) dar fundamento estadístico a estas nociones preliminares, ii) proponer acciones analítico-instrumentales posteriores, y iii) inferir sobre el manejo y la circulación local de la hematita y las prácticas asociadas.
The electron donor-acceptor properties of 9,10-bis((
E
)-2-(pyridin-4-yl)vinyl) anthracene (BP4VA) are studied by means of surface-enhanced Raman scattering (SERS) spectroscopy and vibronic theory of ...resonance Raman spectroscopy. The SERS spectra recorded in an electrochemical cell with a silver working electrode have been interpreted on the basis of resonance Raman vibronic theory assisted by DFT calculations. It is demonstrated that the adsorbate-metal interaction occurs through the nitrogen atom of the pyridyl moiety. Concerning the electron donor-acceptor properties of the adsorbate, it is shown that the charge transfer excited states of BP4VA are not optically active, in contrast, an internal transition to an excited state of BP4VA, which is localized in the anthracene framework, is strongly allowed. The charge transfer states will be populated by an ultrafast non-radiative process, that is, internal conversion. Thus, irradiation of BP4VA interacting with an appropriate surface creates an effective charge separation.
Surface enhanced Raman spectroscopy in conjunction with quantum chemistry is a valuable tool for characterization of organic functional materials.
Abstract only Bone Morphogenetic Proteins (BMP) signaling is required for the development of cardiac hypertrophy. BMP signaling mediates its action via BMP type I and type II receptors. We sought to ...determine which type I receptors are required for cardiac hypertrophy. We studied BMP signaling in neonatal rat cardiomyocytes (NRCs) stimulated with phenylephrine (PE) or isoproterenol (ISO). In comparison with untreated NRCs, PE (10 μM) and ISO (10 μM) induced hypertrophy, as reflected by increases in cell size (457±50 and 401±35 vs 254±23 μm2, p<0.01) and expression of the gene encoding B-type natriuretic peptide (NPPB; 4.0±1.0 and 3.2±0.8-fold, p<0.01). PE and ISO induced expression of genes specifying BMP2 (6.7±0.5 and 5.6±0.6-fold), BMP7 (4.1±0.4 and 3.6±0.9-fold), and the BMP target gene, Id-1, (3.7±0.1 and 4.2±1.0-fold, p<0.001). PE and ISO also induced phosphorylation of BMP-responsive Smads 1 and 5 and increased activity of a BMP response element-luciferase reporter (14.5±0.8 and 11.9±1.1 vs 5.4±0.4, p<0.01). Incubation of NRCs with the BMP inhibitors, LDN193189 (100 nM) or noggin (100 ng/ml), markedly suppressed the ability of PE and ISO to increase cell size, NPPB gene expression, and Smad1/5 phosphorylation. qRT-PCR analysis revealed that ALK2 and ALK3 were highly expressed in NRC, whereas ALK1 and ALK6 were expressed at very low levels. siRNA-mediated silencing of ALK2 or ALK3, but not ALK1 or ALK6, blocked PE-induced hypertrophy in NRCs. Using cardiomyocytes from ALK1flox/flox and ALK2flox/flox neonatal mice infected with Ad-Cre (to delete the floxed allele) or Ad-RFP (as a control) revealed that PE-induced hypertrophy requires Alk2 but not Alk1. Based on these observations, we conclude that BMP signaling is upregulated in NRCs in response to hypertrophic stimuli. ALK2 and ALK3 appear to be the BMP type I receptors which are required for the development of hypertrophy in neonatal cardiac myocytes.
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