Stability of di-butyl-dichalcogenide-capped gold nanoparticles: experimental data and theoretical insights

Metals capped with organochalcogenides have attracted considerable interest due to their practical applications, which include catalysis, sensing, and biosensing, due to their optical, magnetic, electrochemical, adhesive, lubrication, and antibacterial properties. There are numerous reports of metals capped with organothiol molecules; however, there are few studies on metals capped with organoselenium or organotellurium. Thus, there is a gap to be filled regarding the properties of organochalcogenide systems which can be improved by replacing sulfur with selenium or tellurium. In the last decade, there has been significant development in the synthesis of selenium and tellurium compounds; however, it is difficult to find commercial applications of these compounds because there are few studies showing the feasibility of their synthesis and their advantages compared to organothiol compounds. Stability against oxidation by molecular oxygen under ambient conditions is one of the properties which can be improved by choosing the correct organochalcogenide; this can confer important advantages for many more suitable applications. This paper reports the successful synthesis and characterization of gold nanoparticles functionalized with organochalcogenide molecules (dibutyl-disulfide, dibutyl-diselenide and dibutyl-ditelluride) and evaluates the oxidation stability of the organochalcogenides. Spherical gold nanoparticles with diameters of 24 nm were capped with organochalcogenides and were investigated using X-ray photoelectron spectroscopy (XPS) to show the improved stability of organoselenium compared with organothiol and organotellurium. The results suggest that the organoselenium is a promising candidate to replace organothiol because of its enhanced stability towards oxidation by molecular oxygen under ambient conditions and its slow oxidation rate. The observed difference in the oxidation processes, as discussed, is also in agreement with theoretical calculations.

This study presents the improved stability against oxidation by molecular oxygen under ambient conditions of organoselenium compared with organothiol, and organotellurium.     

Electron beam irradiation for the formation of thick Ag film on Ag3PO4

This study demonstrates that the electron beam irradiation of materials, typically used in characterization measurements, could be employed for advanced fabrication, modification, and functionalization of composites. We developed irradiation equipment using an electron beam irradiation source to be applied in materials modification. Using this equipment, the formation of a thick Ag film on the Ag₃PO₄ semiconductor is carried out by electron beam irradiation for the first time. This is confirmed by various experimental techniques (X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy) and ab initio molecular dynamics simulations. Our calculations demonstrate that, at the earlier stages, metallic Ag growth is initiated preferentially at the (110) surface, with the reduction of surface Ag cations forming metallic Ag clusters. As the (100) and (111) surfaces have smaller numbers of exposed Ag cations, the reductions on these surfaces are slower and are accompanied by the formation of O₂ molecules.

This study demonstrates that the electron beam irradiation of materials, typically used in characterization measurements, could be employed for advanced fabrication, modification, and functionalization of composites.     

Long-term follow-up of ruptured intracranial aneurysms treated by microsurgical wrapping with autologous muscle

The purpose of this study is to describe our series of nine unclippable and uncoilable ruptured aneurysms in eight patients treated by microsurgical wrapping with autologous muscle. Records were retrospectively reviewed for rebleeding rate, morbidity and mortality, changes in size or the aneurysm’s configurations, and inflammatory reaction. We conducted a Medline search in the post-microsurgical era, excluding patients in whom wrapping was part of the aneurysm treatment in combination with clipping or coiling. The surgically related morbidity was 12.5 %. Global mortality rate was 25 % due to vasospasm (one case) and rebleeding (one case). Six patients are still alive. Rebleeding rate was 14.3 % within 6 months; then, it was zero. Glasgow outcome scale (GOS) score at discharge was 1 and 4 in one patient, respectively, and 5 in the remaining six. Mean clinical follow-up was 126 months. GOS at last follow-up was 4 and 5 in 50 % of patients, respectively. Mean mRS score was 0.8 at 2 months, and 2.4 at 12 months. Follow-up MR demonstrated persistence of the aneurysm’s sac, without changes in size and configuration. Patients did not describe or exhibit symptoms attributable to complications inherent to the use of muscle. Microsurgical muscle-wrapping of ruptured intracranial aneurysm is safe, is associated with a low rate of acute and delayed postoperative complications and rebleeding, and could be a valid alternative for unclippable and non-amenable to endovascular procedure ruptured aneurysms.     

Laser irradiation did not increase the proliferation or the differentiation of stem cells from normal and inflamed dental pulp

ObjectiveLow-level laser therapy (LLLT) has been reported to be responsible for promoting photostimulatory and photobiomodulatory effects in vivo and in vitro, stimulating cell growth, increasing cell metabolism, improving cell regeneration and invoking an anti-inflammatory response. This study was performed in order to investigate whether low-level laser therapy could increase the proliferation and differentiation potentials of hDPSC isolated from healthy dental pulps and from inflamed pulps.DesignHuman dental pulp stem cells (hDPSC) were isolated from normal and inflamed dental pulps from different patients. STRO-1-positive cells were isolated and irradiated with a red low-level laser (660 nm) in four different energy fluences (0.05, 0.30, 7 and 42 J/cm²); the authors hypothesized that the first three fluences would promote biostimulatory effects, whereas the highest dose would induce antiproliferative effects. The two lower fluences were produced by irradiating the two higher fluences through a dentine disc, which was used to simulate a clinical condition. The proliferation and the cell odonto-osteogenic differentiation competence were compared.ResultsNo statistically significant differences were observed between the proliferation rates and the relative productions of mineralized nodules compared to the respective controls, either for hDPSC from normal or inflamed dental pulps.ConclusionsThe irradiation with low-level InGaAlP red low-level laser (660 nm) in four different energy fluences (0.05, 0.30, 7 and 42 J/cm²) potentiated neither proliferation nor odonto-osteogenic differentiation of hDPSC isolated from patients with normal and inflamed pulps.     

Cryptococcal meningitis in a patient treated with infliximab

Infliximab, a tumor necrosis factor-alpha inhibitor, is increasingly used for the therapy of different inflammatory conditions. We report the first case of cryptococcal meningitis in a patient treated with infliximab and other immunosuppressive agents, and review a further 5 reported cryptococcal infections. All of them involved fungal pneumonia. Outcome was favorable in all cases.     

Second cycle of intralesional Collagenase Clostridium histolyticum for Peyronie's disease using the modified shortened protocol: Results from a retrospective analysis

The purpose of this study was to evaluate the effectiveness and safety of the second cycle of Collagenase Clostridium histolyticum injections using the modified shortened protocol. We performed a retrospective analysis on patients who had already undergone the first cycle of injections using the modified shortened protocol and requested more injections to improve the remaining curvature. The International Index of Erectile Function, the Peyronie's Disease Questionnaire and the Global Assessment of Peyronie's Disease questionnaire were self-administered to all patients. All the parameters were recorded at baseline, after the first cycle and after the second cycle of injections. All adverse events were recorded. Seventeen patients completed two cycles of injections. All patients had a reduction of the initial curvature after the first cycle, with a mean improvement of 17.4° (27.4%). After the second cycle, the reduction of the curvature was 7.9° (17.1%), and 29.4% of patients had no further improvement. No severe side effect was recorded. The results of the present study confirm the effectiveness and safety of the modified shortened protocol of Collagenase C. histolyticum injections for Peyronie's disease. However, the second cycle of three injections may be less effective, and patients may not be completely satisfied.