Johnsharrington7925

The chemical and thermal stability of alkali metal naphthalenides as powerful reducing agents are examined, including the type of alkali metal ([LiNaph] and [NaNaph]), the type of solvent (THF, DME), the temperature (-30 to +50 °C), and the time of storage (0 to 12 hours). The stability and concentration of [LiNaph]/[NaNaph] are quantified via UV-Vis spectroscopy and the Lambert-Beer law. As a result, the solutions of [LiNaph] in THF at low temperature turn out to be most stable. The decomposition can be related to a reductive polymerization of the solvent. The most stable [LiNaph] solutions in THF are exemplarily used to prepare reactive zerovalent iron nanoparticles, 2.3 ± 0.3 nm in size, by reduction of FeCl3 in THF. Finally, the influence of [LiNaph] and/or remains of the starting materials and solvents upon controlled oxidation of the as-prepared Fe(0) nanoparticles with iodine in the presence of selected ligands is evaluated and results in four novel, single-crystalline iron compounds ([FeI2(MeOH)2], ([MePPh3][FeI3(Ph3P)])4·PPh3·6C7H8, [FeI2(PPh3)2], and [FeI2(18-crown-6)]). Accordingly, reactive Fe(0) nanoparticles can be obtained in the liquid phase via [LiNaph]-driven reduction and instantaneously reacted to give new compounds without remains of the initial reduction (e.g. LiCl, naphthalene, and THF).Reaction of [(3-bdppmapy)(AuCl)2] with NaHmba (3-bdppmapy = N,N'-bis-(diphenylphosphanylmethyl-3-aminopytidine, H2mba = 2-mercaptobenzoic acid) resulted in a new tetranuclear Au/P/S complex [(3-bdppmapy)2(AuHmba)3(AuCl)] (1). Upon excitation at 370 nm, 1 exhibited solid state, room temperature, green fluorescent emission (QY = 4.7%, τ = 2.58 ns) which was significantly enanced at lower temperatures due to strengthening of the Au-Au interaction. Different ratios of 1 with phosphor N630 in PMMA were used to make thermochromic photoluminescent films and fibres that could be fabricated into an optical thermometer sensitive over temperature ranges 80-300 K and 300-370 K.New 1-2 nm macrocyclic iodine(I) complexes prepared VIA a simple ligand exchange reaction manifest rigid 0.5-1 nm cavities that bind the hexafluorophosphate anion in the gas phase. The size of the cavities and the electrostatic interactions with the iodine(I) cations influence the anion binding properties of these macrocyclic complexes.Motivated by the recent experimental discovery of high-temperature carbonaceous sulfur hydride (C-S-H), we have systematically explored the superconductivity of a carbonaceous lanthanum hydride (C-La-H) ternary compound in the pressure range of 50-250 GPa. Based on first-principles calculations and strong-coupling Migdal-Eliashberg theory, we find that a hitherto unreported LaC2H8 ternary system is dynamically and thermally stable above 70 GPa in a clathrate structure with space group Fm3̄m and exhibits a superconducting critical temperature, Tc, in the range of 69-140 K.Interfaces formed between a lipid decorated liquid crystal (LC) film and an aqueous phase can mimic the bimolecular membrane where interfacially occurring biological phenomena (e.g., lipid-protein interactions, protein adsorption) can be visually monitored by observing the surface-sensitive orientations of LCs. The ordering behavior of LCs at different phospholipid-based LC interfaces (1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and lysophosphatidic acid (LPA)) were investigated to determine the sensing of an important cytoplasmic protein (juxtamembrane of epidermal growth factor receptor (JM-EGFR)). At both DLPC and LPA decorated interfaces, the LC adopts homeotropic ordering, causing a dark optical appearance under crossed polarizers. Interestingly, upon the introduction of JM-EGFR to these LC-aqueous interfaces, the homeotropic orientation of the LC changed to planar (bright optical appearance), suggesting the potential of the designed system for JM-EGFR sensing. The use of different lipid decorated LC-aqueous interfaces results in the emergence of distinct optical patterns. For example, at a DLPC laden interface, elongated bright domains are observed, whereas a uniform bright texture is observed on an LPA laden interface. The DLPC decorated LC-aqueous interface is found to be highly selective for the sensing of JM-EGFR with a detection limit in the nanomolar concentration region (∼ 50 nM). When compared to spectroscopic and other conventional techniques, the LC-based design is simpler, and it allows the simple and label-free optical sensing of JM-EGFR at fluidic interfaces.This work describes the assembly of a novel enzyme-controlled nanomachine operated through an AND Boolean logic gate for on-command delivery. The nanodevice was constructed on Au-mesoporous silica Janus nanoparticles capped with a thiol-sensitive gate-like molecular ensemble on the mesoporous face and functionalized with glutathione reductase on the gold face. This autonomous nanomachine employed NADPH and glutathione disulfide as input chemical signals, leading to the enzymatic production of reduced glutathione that causes the disruption of the gating mechanism on the mesoporous face and the consequent payload release as an output signal. The nanodevice was successfully used for the autonomous release of doxorubicin in HeLa cancer cells and RAW 264.7 macrophage cells.Fragment-based drug discovery relies on successful optimization of weakly binding ligands for affinity and selectivity. HIF inhibitor Herein, we explored strategies for structure-based evolution of fragments binding to a G protein-coupled receptor. Molecular dynamics simulations combined with rigorous free energy calculations guided synthesis of nanomolar ligands with up to >1000-fold improvements of binding affinity and close to 40-fold subtype selectivity.Development of small molecule biosensors enables rapid and de-centralized small molecule detection that meets the demands of routine health monitoring and rapid diagnosis. Among them, allosteric transcription factor (aTF)-based biosensors have shown potential in modular design of small molecule detection platforms due to their ligand-regulated DNA binding activity. Here, we expand the capabilities of a biosensor that leverages the aTF-based regulation of toehold-mediated strand displacement (TMSD) circuits for uric acid (UA) detection in non-invasive salivary samples by utilizing the UA-responsive aTF HucR. The impact of the low ligand affinity of the native HucR was addressed by engineering a two-pass TMSD circuit with in silico rational design. This combined strategy achieved enrichment of the output signal and overcame the negative impact of the matrix effect on the sensitivity and overall response of the biosensor when using real samples, which enabled semi-quantitative detection in the normal salivary UA levels. As well, enhancements provided by the two-pass design halved the turnaround time to less than 15 minutes. To sum up, the two-cycle DNA circuit design enabled aTF-based simple, rapid and one-step non-invasive salivary UA detection, showing its potential in metabolite detection for health monitoring.

The aim of this study was to investigate the inhibitory effect of different doses of sodium-2-mercaptoethanesulphonate (MESNA) and 5-fluorouracil on cholesteatoma formation.

Fifty-six Wistar albino male rats were divided into seven groups with eight rats in each. On the first, eighth and fifteenth days, 0.2 ml of saline was administered to the group 1 (control group), and propylene glycol to induce cholesteatoma the other groups. On the 22

day of the study, 0.2 ml saline was given to Group 1 and Group 2. Groups 3 to 7 were treated with 0.2 ml 100% MESNA, 0.2 ml 50% MESNA, 0.2 ml 20% MESNA, 0.2 ml 5-fluorouracil and 0.1 ml 100% MESNA plus 0.1 ml 5-fluorouracil, respectively, with all applications performed by intratympanic injection.

Significant differences were found between Group 1 and all other groups except Group 3. Significant differences were also found between Group 3 and Groups 2, 5 and 6 (P < 0.05).

According to the results of this study, experimental cholesteatoma induced with propylene glycol may be inhibited by MESNA at 100% concentration.

According to the results of this study, experimental cholesteatoma induced with propylene glycol may be inhibited by MESNA at 100% concentration.

To evaluate mean surgical time, incidence of soft tissue reactions, implant survival and intraoperative complications in both minimally invasive ponto surgery (MIPS) and the linear incision with tissue preservation technique (LT).

A retrospective review was carried out on 48 bone anchored hearing system (BAHS) patients between 2014 and 2019 13 patients had undergone LT and formed one group, while 35 patients had undergone MIPS and formed the second group. Mean surgical time, intraoperative complications, implant loss and skin reaction were assessed at each post-operative examination. The Mann-Whitney U test was used for statistical analysis.

The difference in the mean surgical time of 15 mins for MIPS and 36 mins for LT was statistically significant. No intraoperative complications were reported and implant survival was 100% in both groups. The incidence of adverse skin reactions was 7.7% for the LT group and 0% for the MIPS group at first follow-up examination.

Surgical mean time is shorter for MIPS, making this procedure more suitable for local anaesthesia and more cost effective. Moreover, both LT and MIPS demonstrate good surgical outcomes in terms of skin reactions according to Holgers score and equally excellent implant survival.

Surgical mean time is shorter for MIPS, making this procedure more suitable for local anaesthesia and more cost effective. Moreover, both LT and MIPS demonstrate good surgical outcomes in terms of skin reactions according to Holgers score and equally excellent implant survival.

The treatment of choice for Ménière disease (MD) aims at preventing severity and frequency of vertigo attacks. The purpose of this study was to evaluate the effectiveness of ventilation tube (VT) placement on vertigo control in patients affected by MD with no response to standard medical therapy.

76 consecutive outpatients diagnosed with definite MD who failed medical therapy received VT insertion at the Department of Otolaryngology Head and Neck Surgery, "Ospedale del Mare", Naples, Italy, with a 3-year follow up.

Over the long term, VT placement was effective in controlling vertigo in 61.8% of patients. In the control group treated with standard preventive care (SPC) alone, all patients continued to experience recurrent vertigo during the entire study. Comparison of survival curves by using the log-rank test shows that significant differences in survival exist between subjects treated with VT placement and the control sample (p = 0.001).

Our long-term follow-up confirms that VT placement is an effective and safe management option in intractable definite MD, especially in the elderly or in those refusing more invasive treatments.

Our long-term follow-up confirms that VT placement is an effective and safe management option in intractable definite MD, especially in the elderly or in those refusing more invasive treatments.

Benign paroxysmal positional vertigo (BPPV) is a disorder of the inner ear with a high rate of recurrence. Vascular disorders, migraine and autoimmune disorders have been considered facilitating factors for relapsing episodes. Our aim was to assess the role of vascular disorders, migraine and anti-thyroid antibodies in patients with recurrences.

We retrospectively analysed records of 3042 patients treated for BPPV without other lifetime vertigo. Clinical data included previous vascular disorders of the central nervous system, heart disorders, migraine and recent head trauma. The presence of anti-thyroid autoantibodies was assessed in all patients.

Mean age of the first BPPV was 52.8 ± 14.5 years; there were 2339 females (76.9%), while 2048 (67.3%) of patients presented recurrences within two years of follow-up. Previous disorders of the central nervous system, presence of anti-thyroid antibodies, head trauma and migraine showed an association with recurrences. Above all, in subjects having the first BPPV while aged between 40 and 60 years, anti-thyroid antibodies were predictive for recurrences.