Summary
Silver (Ag)‐doped PbS (PbS:Ag) thin films of 616 to 745 nm in thickness were prepared on glass substrates via cost‐effective nebulizer spray method by adding different Ag levels from 2% to 8% ...at 200°C. For solar cell applications, the effect of Ag doping concentration on structural, morphological, optical, photoluminescence, and electrical chattels of PbS thin film has been studied. X‐ray diffraction pattern confirmed the polycrystalline behavior of the prepared PbS:Ag films with cubic crystalline nature. The crystalline size and texture coefficient were increased by increasing Ag doping concentration. From the morphological studies by scanning electron microscope (SEM) and atomic force microscope (AFM), the grain size of the films and surface roughness values were increased for the increase in Ag doping concentration. EDS spectra confirmed the existence of Ag, Pb, and S elements in the select 6% Ag‐doped PbS film. Peaks related to silver oxide started to emerge at 6% of Ag doping level. The optical direct band gap value was reduced from 1.51 to 1.17 eV for Ag doping from 2% to 6% and thereby slightly increased as 1.79 eV for 8% Ag doping level. For all PbS:Ag films, the photoluminescence spectrum emitted a strong near band edge (NBE) emission at approximately 580 nm, meaning better optical quality. Hall effect measurements evidenced that Ag doping provides enhancement on the characteristics of mobility, carrier concentration, and resistivity with p‐type conducting nature. The observed high carrier concentration and low resistivity values were 4.32 × 1014 cm−3 and 80 Ωcm, for 6% Ag‐doped PbS film. The FTO/CdS/PbS:Ag heterostructure solar cell was formed from 6% Ag‐doped film.
Ocular repeated air blast injuries occur from low overpressure blast wave exposure, which are often repeated and in quick succession. We have shown that caspase-2 caused the death of retinal ganglion ...cells (RGC) after blunt ocular trauma. Here, we investigated if caspase-2 also mediates RGC apoptosis in a mouse model of air blast induced indirect traumatic optic neuropathy (b-ITON). C57BL/6 mice were exposed to repeated blasts of overpressure air (3 × 2 × 15 psi) and intravitreal injections of siRNA against caspase-2 (siCASP2) or against a control enhanced green fluorescent protein (siEGFP) at either 5 h after the first 2 × 15 psi ("post-blast") or 48 h before the first blast exposure ("pre-blast") and repeated every 7 days. RGC counts were unaffected by the b-ITON or intravitreal injections, despite increased degenerating ON axons, even in siCASP2 "post-blast" injection groups. Degenerating ON axons remained at sham levels after b-ITON and intravitreal siCASP2 "pre-blast" injections, but with less degenerating axons in siCASP2 compared to siEGFP-treated eyes. Intravitreal injections "post-blast" caused greater vitreous inflammation, potentiated by siCASP2, with less in "pre-blast" injected eyes, which was abrogated by siCASP2. We conclude that intravitreal injection timing after ocular trauma induced variable retinal and ON pathology, undermining our candidate neuroprotective therapy, siCASP2.
Frustrated Lewis pairs (FLPs) have evolved from a revolutionary concept to widely applied catalysts. We recently reported the ring-expanded N-heterocyclic carbene supported copper(I) ...boryliminomethanide, (6-Dipp)CuC(=NtBu)Bpin and noted it reacted with heterocumulenes in a fashion reminiscent of FLPs. We thus set out to explore its reactivity with a range of other substrates known to react with FLPs. This was undertaken by a series of synthetic studies using NMR spectroscopy, mass spectrometry, IR spectroscopy, and single crystal X-ray crystallography. (6-Dipp)CuC(=NtBu)Bpin was investigated for its reactivity towards water, hydrogen, and phenylacetylene. Its solution stability was also explored. Upon heating, (6-Dipp)CuC(=NtBu)Bpin decomposed to (6-Dipp)CuCN, which was characterised by SC-XRD and NMR spectroscopy, and pinBtBu. Although no reaction was observed with hydrogen, (6-Dipp)CuC(=NtBu)Bpin reacted with water to form (6-Dipp)CuC(=N(H)tBu)B(OH)pin, which was structurally characterised. In contrast to its FLP-reminiscent heterolytic cleavage reactivity towards water, (6-Dipp)CuC(=NtBu)Bpin acted as a Brønsted base towards phenyl acetylene generating (6-Dipp)CuCCPh, which was characterised by SC-XRD, IR, and NMR spectroscopy, and HC(=NtBu)Bpin
Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of ...germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels.
In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes.
In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal temperature. Physiologically, this is important since delaying germination has a protective role at high temperature. Transcriptomic analysis of seeds imbibed at supraoptimal temperature reveal that a complex program is in place, which involves not only the regulation of heat and dehydration response genes to adjust cellular functions, but also the activation of seed-specific programs and the inhibition of germination-promoting programs to delay germination.
Efficacy of Topical Epinephrine in Tympanoplasty List, Marna A.; Dirain, Carolyn O.; Haberman, Rex S. ...
The Laryngoscope,
October 2021, 2021-10-00, 20211001, Letnik:
131, Številka:
10
Journal Article
Recenzirano
Objectives/Hypothesis
To compare the hemostatic effects of commonly used concentrations of topical epinephrine in tympanoplasty.
Study Design
Prospective, randomized, controlled clinical trial.
...Methods
Patients undergoing tympanoplasty were randomized to receive topical epinephrine at 1:1,000 or 1:10,000. With the investigators blinded, hemostasis was assessed with a modified Boezaart scale. Vasoconstriction was measured by laser Doppler. Blood pressure and pulse were tracked.
Results
Thirty patients, 4 to 84 years old, were studied, with 15 patients per group. Boezaart scores dropped a mean of 67% and 62% with 1:1,000 and 1:10,000, respectively (P = .44). Capillary blood flow decreased a mean of 50.4% and 50.9% with 1:1,000 and 1:10,000, respectively (P = .95). The mean change in heart rate and mean arterial pressure after topical epinephrine exposure were −4.9 and −0.73 beats per minute (P = .15), and −0.60 and −0.73 mmHg (P = .96) for 1:1,000 and 1:10,000 respectively. No adverse events occurred in either group.
Conclusions
Topical epinephrine at 1:10,000 has hemostatic efficacy comparable to 1:1,000 in tympanoplasty. Although both concentrations appear safe, use of topical epinephrine 1:10,000 should be considered over 1:1,000 to minimize the potential for adverse events.
Level of Evidence
2 Laryngoscope, 131:2319–2322, 2021
Brain-derived neurotrophic factor (BDNF) is an extremely potent, positive modulator of theta burst induced long-term potentiation (LTP) in the adult hippocampus. The present studies tested whether ...the neurotrophin exerts its effects by facilitating cytoskeletal changes in dendritic spines. BDNF caused no changes in phalloidin labeling of filamentous actin (F-actin) when applied alone to rat hippocampal slices but markedly enhanced the number of densely labeled spines produced by a threshold level of theta burst stimulation. Conversely, the BDNF scavenger TrkB-Fc completely blocked increases in spine F-actin produced by suprathreshold levels of theta stimulation. TrkB-Fc also blocked LTP consolidation when applied 1-2 min, but not 10 min, after theta trains. Additional experiments confirmed that p21 activated kinase and cofilin, two actin-regulatory proteins implicated in spine morphogenesis, are concentrated in spines in mature hippocampus and further showed that both undergo rapid, dose-dependent phosphorylation after infusion of BDNF. These results demonstrate that the influence of BDNF on the actin cytoskeleton is retained into adulthood in which it serves to positively modulate the time-dependent LTP consolidation process.
σ‐Bond metathesis reactions between (6‐Dipp)CuOtBu (6‐Dipp=:C({Dipp}NCH2)2CH2, Dipp=2,6‐iPr2−C6H3) and three diboranes gave access to three new copper(I) boryl complexes (6‐Dipp)CuBcat, ...(6‐Dipp)CuBneop, and (6‐Dipp)CuBhex (cat=1,2‐O2C6H4; neop=(OCH2)2C(CH3)2; hex=OC(CH3)HCH2C(CH3)2O). Whilst (6‐Dipp)CuBcat and (6‐Dipp)CuBneop formed rapidly in toluene, access to (6‐Dipp)CuBhex required heating to 60 °C for days. The complexes were characterised by single‐crystal X‐ray crystallography which showed in all three cases that the systems were monomers and distorted‐linear at the copper atom. The stability of (6‐Dipp)CuBneop was found to be comparable to that of (IPr*)Cu‐Bneop (IPr*=1,3‐bis(2,6‐(diphenylmethyl)‐4‐methylphenyl)imidazol‐2‐ylidene); it persisted in solution for days with no sign of decomposition. (6‐Dipp)CuBhex is a rare crystallographically characterised example of a complex containing a boryl anion supported by the hexylene glycolato ligand.
A ring‐expanded NHC with flanking di‐iso‐propylphenyl groups has been shown to support 3 copper(I) boryl systems. This allows the structural characterisation of (6‐Dipp)CuBcat, (6‐Dipp)CuBneop, and (6‐Dipp)CuBhex (cat=1,2‐O2C6H4; neop=(OCH2)2CMe2; hex=OC(CH3)HCH2C(CH3)2O). All three compounds are reasonably stable, readily isolable sources of boryl nucleophiles, and (6‐Dipp)CuBhex is a rare example of a boryl anion bearing the hexylene glycol ester.
Highlights • GLYX-13 produces antidepressant-like effects for ⩾1 week following a single dose. • GLYX-13 facilitates learning and memory for ⩾1 week following a single dose. • GLYX-13 enhances ...hippocampal metaplasticity 24 h – 2 weeks following a single dose. • Repeat doses of GLYX-13 maintained the metaplasticity effects for at least 8 weeks. • GLYX-13 increased the number of mature dendritic spines 24 h after a single dose.
Reorganization of the actin cytoskeleton is essential for synaptic plasticity and memory formation. Presently, the mechanisms that trigger actin dynamics during these brain processes are poorly ...understood. In this study, we show that myosin II motor activity is downstream of LTP induction and is necessary for the emergence of specialized actin structures that stabilize an early phase of LTP. We also demonstrate that myosin II activity contributes importantly to an actin-dependent process that underlies memory consolidation. Pharmacological treatments that promote actin polymerization reversed the effects of a myosin II inhibitor on LTP and memory. We conclude that myosin II motors regulate plasticity by imparting mechanical forces onto the spine actin cytoskeleton in response to synaptic stimulation. These cytoskeletal forces trigger the emergence of actin structures that stabilize synaptic plasticity. Our studies provide a mechanical framework for understanding cytoskeletal dynamics associated with synaptic plasticity and memory formation.
► Defines a mechanical process controlling F-actin reorganization at synapses ► Myosin II motor activity is engaged by LTP induction ► Myosin II activity produces de novo actin filaments at synapses that maintain LTP ► Myosin II activity regulates actin polymerization that supports memory formation
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