A Tesla-pulse forming line-plasma opening switch pulsed power generator

A pulsed power generator based on a high-voltage Tesla transformer which charges a 3.85 /55 ns water-filled pulse forming line to 300 kV has been developed at Loughborough University as a training tool for pulsed power students. The generator uses all forms of insulation specific to pulsed power technology, liquid oil and water , gas SF6 , and magnetic insulation in vacuum, and a number of fast voltage and current sensors are implemented for diagnostic purposes. A miniature centimeter-size plasma opening switch has recently been coupled to the output of the pulse forming line, with the overall system comprising the first phase of a program aimed at the development of a novel repetitive, table-top generator capable of producing 15 GW pulses for high power microwave loads. Technical details of all the generator components and the main experimental results obtained during the program and demonstrations of their performance are presented in the paper, together with a description of the various diagnostic tools involved. In particular, it is shown that the miniature plasma opening switch is capable of reducing the rise time of the input current while significantly increasing the load power. Future plans are outlined in the conclusions

A miniature high-power pos driven by a 300 kV Tesla-charged PFL generator

A pulsed power generator based on a high-voltage Tesla transformer charging a 3.8 ¿/53 ns water-filled pulse forming line (PFL) to 300 kV has been developed at Loughborough University as a training tool for pulsed-power students. The generator uses all forms of insulation specific to pulsed power technology - liquid (oil and water), gas (SF6) and vacuum, a series of fast voltage and current sensors, and is able to produce multi-GW pulses on a simple x-ray diode load. Recently, a miniature (cm-size) plasma opening switch (POS) using protons (H+ ions) has been coupled to the output of the Tesla-charged PFL generator, with the overall system constituting the first phase of a programme aimed at the development of a novel repetitive, table-top generator capable of producing 15 GW pulses for high power microwave loads. Experimental results demonstrating the performance of the POS in reducing the rise time of the input current while increasing the load power are presented, together with constructional details and diagnostic techniques. Future plans are outlined

Разработка учебно-методического обеспечения дисциплины "Физика информационных технологий"

Right-handed subjects only, between-sex differences for all models. Excel file showing global and main effects of RMANOVA for original model (left-most) and four models with age-related effects. The effects are compared with the models with all subjects (Additional file 1), and the significance classified via color-coding cells as “same” (green) or “changed” (orange) according to whether the P value shifted from below or above the 0.05 threshold. (XLSX 14 kb

Role of Macromolecular Crowding on Stability and Iron Release Kinetics of Serum Transferrin

The macromolecular crowding influences the structural stability and functional properties of transferrin (Tf). The equilibrium as well as kinetic studies of Tf at different concentrations of crowding agents (dextran 40, dextran 70, and ficoll 70) and at a fixed concentration of dextran 40 under different concentrations of NaCl at pH 7.4 and 5.6 (±1) revealed that (i) the crowder environment increases the diferric-Tf (Fe₂Tf) stability against iron loss and overall denaturation of the protein, (ii) both in the absence and presence of crowder, the presence of salt promotes the loss of iron and overall denaturation of Fe₂Tf which is due to ionic screening of electrostatic interactions, (iii) the crowder environment retards iron release from monoferric N-lobe of Tf (Fe_NTf) by increasing enthalpic barrier, (iv) the retardation of iron release by crowding is enthalpically dominated than the entropic one, (v) both in the absence and presence of crowder, the presence of salt accelerates the iron release from Fe_NTf due to ionic screening of electrostatic interactions and anion binding to KISAB sites, and (vi) the crowders environment is unable to diminish (a) the salt-induced destabilization of Fe₂Tf against the loss of iron and overall denaturation and (b) the anion effect and ionic screening of diffusive counterions responsible to promote iron release from Fe_NTf

Optimizing Photovoltaic Charge Generation of Hybrid Heterojunction Core–Shell Silicon Nanowire Arrays: An FDTD Analysis

Development of highly efficient nanowire-based photovoltaic devices requires an accurate modeling of light scattering from interfaces and optical carrier generation inside the cell. A comprehensive study of optical absorption and carrier generation enables us to tap the full potential of nanowire arrays (NWAs). In this study, we have done a systematic study to optimize the core–shell structure of vertically aligned silicon nanowire (Si NW) arrays coated with PTB7:PC₇₁BM by means of finite difference time domain optical simulations to maximize the photon absorption. Initially, the core thickness of hybrid Si NWs has been optimized for the most efficient light absorption. The further improvement of light absorption has been studied by varying the coating thickness of low-band gap organic polymer PTB7:PC₇₁BM on Si NWAs. A delineative analysis shows that NWs with a 150 nm thick silicon core and 60 nm thick coating of PTB7:PC₇₁BM exhibit broad band absorption and the optimum ideal current density of about 34.95 mA/cm², which are larger than those of their planar counterpart with the same amount of absorbing material and also better than those previously reported for NWs. The basic principle and the physical process taking place during absorption and current generation have been also discussed. The optimization of the hybrid heterojunction Si NW arrays and understanding of their optical characteristics may contribute to the development of economical and highly efficient hybrid solar cells

Protonation and Anion Binding Control the Kinetics of Iron Release from Human Transferrin

Iron release in vitro from human serum diferric transferrin (hFe₂Tf) in acidic media (4.2 ≤ pH ≤ 5.4) in the presence of nonsynergistic anions occurs in at least five kinetic steps. Step 1 (most rapid) involves proton assisted release of carbonate from the protein. In subsequent steps, iron release from both the N- and C-terminal lobes is controlled by slow proton transfers and anion binding. In step 2, the N-terminal lobe takes up one proton with kinetic linkage to the binding of one anion. In step 3, iron release from the anion-linked N-terminal lobe is controlled by slow uptake of two protons with rate-constant, <i>k</i>_2N, of 2.6(6) × 10⁷, 6.1(6) × 10⁷, and 9(1) × 10⁷ M^–2 s^–1 in the presence of Cl^–, NO₃^–, and SO₄^2–, respectively. In step 4, the C-terminal lobe takes up one proton with kinetic linkage to the binding of one anion. In step 5, iron release from the anion-linked C-terminal lobe is controlled by slow uptake of two protons with rate-constant, <i>k</i>_2C, of 8.4(2) × 10⁴, 4.4(6) × 10⁵, and 8.1(2) × 10⁵ M^–2 s^–1 in the presence of Cl^–, NO₃^–, and SO₄^2–, respectively

Prion Aggregates Are Recruited to the Insoluble Protein Deposit (IPOD) via Myosin 2-Based Vesicular Transport

<div><p>Aggregation of amyloidogenic proteins is associated with several neurodegenerative diseases. Sequestration of misfolded and aggregated proteins into specialized deposition sites may reduce their potentially detrimental properties. Yeast exhibits a distinct deposition site for amyloid aggregates termed “Insoluble PrOtein Deposit (IPOD)”, but nothing is known about the mechanism of substrate recruitment to this site. The IPOD is located directly adjacent to the Phagophore Assembly Site (PAS) where the cell initiates autophagy and the Cytoplasm-to-Vacuole Targeting (CVT) pathway destined for delivery of precursor peptidases to the vacuole. Recruitment of CVT substrates to the PAS was proposed to occur via vesicular transport on Atg9 vesicles and requires an intact actin cytoskeleton and “<b>SNA</b>P (Soluble <a href="https://en.wikipedia.org/wiki/N-ethylmaleimide_Sensitive_Factor_or_fusion_protein" target="_blank">NSF</a> Attachment Protein) <b>Re</b>ceptor Proteins (SNARE)” protein function. It is, however, unknown how this vesicular transport machinery is linked to the actin cytoskeleton. We demonstrate that recruitment of model amyloid PrD-GFP and the CVT substrate precursor-aminopeptidase 1 (preApe1) to the IPOD or PAS, respectively, is disturbed after genetic impairment of Myo2-based actin cable transport and SNARE protein function. Rather than accumulating at the respective deposition sites, both substrates reversibly accumulated often together in the same punctate structures. Components of the CVT vesicular transport machinery including Atg8 and Atg9 as well as Myo2 partially co-localized with the joint accumulations. Thus we propose a model where vesicles, loaded with preApe1 or PrD-GFP, are recruited to tropomyosin coated actin cables via the Myo2 motor protein for delivery to the PAS and IPOD, respectively. We discuss that deposition at the IPOD is not an integrated mandatory part of the degradation pathway for amyloid aggregates, but more likely stores excess aggregates until downstream degradation pathways have the capacity to turn them over after liberation by the Hsp104 disaggregation machinery.</p></div

Regio- and Stereoselective Intermolecular Oxysulfonylation of Alkynes with 1,3-Diketones to Access (<i>Z</i>)‑β-Sulfonated Enethers

The first multicomponent regio- and stereoselective difunctionalization of alkynes via concomitant C–O and C–S bond formation using 1,3-diketones and sodium sulfinate has been developed for the synthesis of various sulfonated enethers. The viability of this strategy is unveiled by gram-scale, various synthetic modifications and late-stage functionalization. This transformation does not require any prefunctionalization, metal catalysts, and oxidants. The present operationally simple, efficient, and sustainable approach provides various functionalized olefins in a one-pot protocol with high Z-selectivity

Ferrocene-Functionalized Fulleropyrrolidine Derivative: A Performance Enhancer for Solid-State Electrochromic Devices

A custom-designed ferrocene-functionalized fulleropyrrolidine derivative Fullerene-Fc has been synthesized, which proves to be a feasible material to improve the performance of solid-state electrochromic devices. The molecule can be used as a dopant to design devices on substrates of rigid (glass) as well as flexible (PET) nature. The switching speed of devices made using poly(3-hexylthiophene) and ethyl viologen could be improved to display a switching time of less than 1 s when the Fullerene-Fc molecule was added. The improvement in the performance of the electrochromic device is likely due to the solution processability of the Fullerene-Fc molecule compatible with other used electrochromic active materials, which helps to facilitate the necessary charge carriers for the redox reaction within the device. Additionally, a coloration efficiency of more than 350 cm2/C and cyclic stability of up to 500 s were shown by the device with a color contrast of more than 40%. Furthermore, the Fullerene-Fc molecule in the P3HT/EV device can be incorporated to fabricate an all-organic flexible device. The charge storage properties of fullerene and the redox behavior of ferrocene make it a good choice to be used as an electrochromic performance enhancer

Identification of PrD amyloid binding proteins.

<p>(<b>A</b>) Electron Microscopy (EM) of PrD amyloid fibers prepared from biotin-labeled and unlabeled recombinant PrD at a ratio of 1:50 after negative staining with uranyl acetate at 50000X magnification. Scale bar, 250 nm. (<b>B</b>) Biotin-labeled PrD fibers were immobilized to avidin-coated magnetic beads and incubated with [<i>PSI</i>⁺] cell lysates. Proteins bound to the resin were eluted by boiling in SDS sample buffer, subjected to SDS-PAGE and stained with Coomassie. The left lane shows the eluate from PrD-fiber containing resin, the right lane an eluate from a control resin without PrD fibers. Eluted proteins were subsequently identified by mass spectrometry (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006324#pgen.1006324.s011" target="_blank">S1 Table</a>).</p