Abstract
The technology of creating patterned flexible electrodes based on single-walled carbon nanotubes and polydimethylsiloxane was demonstrated in this paper. A series of experiments were carried ...out to study whether the percolation affects the conductivity of patterned SWCNT layers. It was found that in patterns with the linewidth above 1 μm and the cell size above 50 μm the random character of SWCNT networks may be neglected. The impact of bending on the grid conductivity was studied. We observed a very moderate increase of resistance below 5% under the strain up to 4 %, which is comparable with the previous results for continuous SWCNT layers and shows the improvement in comparison with the previous reports on patterned SWCNT layers.
▶ Femtosecond laser machining of PCL electrospun membranes. ▶ Useful platform for fabricating patterned structures on membranes. ▶ Ultrafast laser processing of materials can minimize and control ...deformation of electrospun fibers.
We demonstrate that a femtosecond laser can be used to machine arbitrary patterns and pattern arrays into free-standing electrospun polycaprolactone (PCL) membranes. We also examine the influence of various laser irradiation settings on the final microstructure of electrospun membranes. A beam fluence of 0.6J/cm2 is used to ablate holes in 100μm thick PCL membranes. The machined holes have an average diameter of 436μm and a center-to-center spacing of 1000μm. Based on these results, the femtosecond ablation of electrospun membranes shows great potential for fabricating a variety of functional tissue scaffolds. This technique will advance scaffold design by providing the ability to rapidly tailor surface morphology, while minimizing and controlling the deformation of the electrospun fibers.
•MEG data from 7 TS patients with surgically confirmed epileptogenic zone location.•Interictally “MEG-silent” tubers were not epileptogenic.•Interictally “EEG/MEG-active” tuber not necessarily ...coincided with EZ.•Ictal MEG helped to select the EZ among several interictally “MEG-active” tubers.•Combination of ictal/interictal MEG may improve the non-invasive evaluation of EZ.
Drug resistant epilepsy (DRE) is common in patients with tuberous sclerosis (TS). Interictal MEG has been shown as a valuable instrument in the presurgical workup. The goal of our study was to evaluate the role of ictal MEG in epileptogenic tuber selection, especially in patients with multiple irritative zones.
The clinical and MEG data of 23 patients with TS and DRE from two medical/research centers were reviewed. Seven pediatric patients, who had seizures during MEG recording and underwent resection or disconnection surgery, were included into the study. Cortical sources of ictal and interictal epileptiform MEG discharges were compared with epileptogenic zone location in six patients with favorable surgery outcome.
In patients who improved substantially after surgery all resected and several other tubers demonstrated epileptiform activity on interictal MEG. Ictal MEG provided crucial information about lobar location of the seizure onset zone (SOZ) in two cases, and in the other four it confirmed the SOZ location derived from the interictal data. In one case, ictal MEG findings were unreliable. In one patient, who did not benefit from surgical treatment, the resected tubers did not overlap with interictal and ictal MEG sources.
The combination of interictal and ictal MEG is a valuable tool for identification of the epileptogenic tuber/tubers in presurgical work-up in patients with TS.
A comparative study of residual thermal effects in aluminum following ns- and fs-laser ablation shows a surprisingly similar trend in their behavior, despite many differences between ns and fs ...laser-matter interactions. At laser fluences above the ablation threshold where plasmas are produced and at a sufficiently high ambient gas pressure, an enhanced coupling of pulsed laser energy to the sample occurs. This effect appears to be a universal phenomenon for both ns- and fs-laser ablation in gas media. Furthermore, in contrast to the common belief that residual thermal energy is negligible in fs-laser ablation, our study shows that up to 70% of the incident pulse energy can be retained in the sample following single-pulse fs-laserablation in 1-atm air. In both ns- and fs-laser ablation, the major factors governing thermal energy coupling to the sample are the laser fluence and ambient gas pressure. Residual thermal energy deposition decreases with reducing ambient gas pressure.
We recently synthesized prospective new materials composed of alternating quasi-atomic sheets of brucite-type hydroxide (Mg, Fe)(OH)2 and CuFe1–x S2 sulfide (valleriites). Herein, their thermal ...behavior important for many potential applications has been studied in inert (Ar) and oxidative (20% O2) atmospheres using thermogravimetry (TG) and differential scanning calorimetry (DSC) analyses and characterization with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). In the Ar media, the processes are determined by the dehydroxylation of the hydroxide layers forming MgO, with the temperature of the major endothermic maximum of the mass loss at 413 °C. Sulfide sheets start to degrade below 500 °C and melt at nearly 800 °C, with bornite, chalcopyrite, and troilite specified as the final products. In the oxidative atmosphere, the exothermic reactions with the mass increase peaked at 345 and 495 °C, corresponding to the partial and major oxidations of Cu–Fe sulfide layers. Sulfur oxides captured in magnesium hydroxide layers to form MgSO4 compromised the layer integrity and promoted the oxidation of the sulfide entities. The final products also contained minor MgO, Cu2MgO3, Fe3O4, and MgFe2O4 phases. Samples doped with Al, which decreases the content of Fe in hydroxide layers, show notably impeded decay of valleriite in argon but facilitated the oxidation of Cu–Fe sulfides, while the impact of Li (it slightly increases the number of the Fe–OH sites) was less expressed. The mutual stabilization of the two-dimensional (2D) hydroxide and sulfide layers upon heating in an inert atmosphere but not in oxygen as compared with bulk brucite and chalcopyrite was suggested to explain high thermal resistance across the stacked incommensurate sheets, which slows down the endothermic reactions and accelerates the exothermic oxidation; the high number of Fe atoms in the hydroxide sheets are expected to promote the phonon exchange and heat transfer between the layers.
The healing potential of individual polymer implants for the reconstruction of extensive craniofacial defects after cancer resection is largely determined by the internal architecture of the implant. ...The architecture of an implant during polymer crystallization could affect the structure and shape of the implant at the micro and macro levels. In this study, the relationship between the internal architecture (triply periodic minimum surface structure (gyroid), cube, grid, and honeycomb) and shape changes of individual implants by 3D printing with a vinylidene fluoride-tetrafluoroethylene copolymer after crystallization is examined at a filling density of 70%. Using the method of differential scanning calorimetry, it is established that crystallization leads to the rearrangement of the crystalline structure of the implant into electrically active (ferroelectric) crystalline phases. Moreover, the type of internal architecture affects the change in the shape of the implant after crystallization. The results of the computed tomography show that structures with a triply periodic minimum surface (gyroid) provide the minimal deformation of the implant during crystallization, which makes such structures optimal for manufacturing implants for replacing bone defects in the zygomatic-orbital complex.
The behavior of hydroxyapatite containing zinc and silicate ions during selective laser melting under irradiation at 10.6 µm was studied for the first time. For comparison, the behavior of the ...material heated in a high-temperature furnace was investigated. It was found that, in contrast to the slow heating in the furnace, heating of the mechanochemically synthesized material with the degree of substitution
x
= 0.2 by scanning the laser spot enables its recrystallization with retention of substituent ions in the apatite structure. At high degrees of substitution (
x
= 1, 2), hydroxyapatites are unstable under both heating regimes. Different heating conditions lead to the formation of different impurity phases.
To characterize a group of patients with follicular lymphoma (FL) with leukemization and to evaluate the efficiency of different therapy options (R-CHOP/R-FMC/high-dose chemotherapy (HDCT)).
18 ...(7.2%) out of 250 patients diagnosed with FL, who were examined and treated at the National Research Center for Hematology, Ministry of Health of the Russian Federation, were found to have leukemic FL (tumor cells in the peripheral blood smears were detected by cytology and flow cytofluorometry. Eight of the 18 patients had extranodal foci of involvement: lung, stomach, spleen, lumbar muscles, upper jaw, and vertebrae. Bone marrow was involved in 17 of the 18 patients. Tumor biopsy specimens displayed a morphological pattern of indolent FL in the majority of patients (10 of the 18 patients had cytological grade 1-2 tumors and 14 patients had a nodular or nodular-diffuse tumor growth pattern). The patients underwent R-CHOP/R-FMC) or HDCT cycles as first-line therapy, followed by autologous stem cell transplantation (auto-SCT).
The median follow-up was 66 months (range 12-217 months). The 5-year overall survival (OS) and progression-free survival (PFS) rates were 70% (10% SEM) and 35% (15% SEM), respectively. The median OS was not reached; the median PFS was 3 years.
Leukemic FL is characterized by low OS and PFS rates. The most effective chemotherapy regimens were R-CHOP, followed by HDCT and auto-SCT in first remission or R-FMC. These cycles can to a greater extent achieve a complete eradication of the bone marrow tumor clone. Due to the relapsing course of FL and the aggressiveness of leukemic FL, it is expedient to carry out auto-SCT in first remission.
The work is dedicated to the development of the optimal technological process for the manufacture of hot stamping dies and die casting molds made of steel grade 4X5MF1С, in order to ensure the ...required performance characteristics. The mode of hardening heat treatment of this steel grade was established, which allows to recommend it as a heat-resistant structural material for metal products with the required yield strength σ0.2 within 750 to 1000 MPa.
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