Geometric Suppression of Single-Particle Energy Spacings in Quantum Antidots

Quantum Antidot (AD) structures have remarkable properties in the integer quantum Hall regime, exhibiting Coulomb-blockade charging and the Kondo effect despite their open geometry. In some regimes a simple single-particle (SP) model suffices to describe experimental observations while in others interaction effects are clearly important, although exactly how and why interactions emerge is unclear. We present a combination of experimental data and the results of new calculations concerning SP orbital states which show how the observed suppression of the energy spacing between states can be explained through a full consideration of the AD potential, without requiring any effects due to electron interactions such as the formation of compressible regions composed of multiple states, which may occur at higher magnetic fields. A full understanding of the regimes in which these effects occur is important for the design of devices to coherently manipulate electrons in edge states using AD resonances.Comment: 4 pages, 2 figure

Dephasing Times in a Non-degenerate Two-Dimensional Electron Gas

Studies of weak localization by scattering from vapor atoms for electrons on a liquid helium surface are reported. There are three contributions to the dephasing time. Dephasing by the motion of vapor atoms perpendicular to the surface is studied by varying the holding field to change the characteristic width of the electron layer at the surface. A change in vapor density alters the quasi-elastic scattering length and the dephasing due to the motion of atoms both perpendicular and parallel to the surface. Dephasing due to the electron-electron interaction is dependent on the electron density.Comment: 4 pages, Revte

Antifungal screening and in silico mechanistic studies of an in-house azole library

Systemic Candida infections pose a serious public health problem with high morbidity and mortality. C. albicans is the major pathogen identified in candidiasis, however non-albicans Candida spp. with antifungal resistance are now more prevalent. Azoles are first-choice antifungal drugs for candidiasis, however they are ineffective for certain infections caused by the resistant strains. Azoles block ergosterol synthesis by inhibiting fungal CYP51, which leads to disruption of fungal membrane permeability. In this study, we screened for antifungal activity of an in-house azole library of 65 compounds to identify hit matter followed by a molecular modelling study for their CYP51 inhibition mechanism. Antifungal susceptibility tests against standard Candida spp. including C. albicans revealed derivatives 12 and 13 as highly active. Furthermore, they showed potent antibiofilm activity as well as neglectable cytotoxicity in a mouse fibroblast assay. According to molecular docking studies 12 and 13 have the necessary binding characteristics for effective inhibition of CYP51. Finally, molecular dynamics (MD) simulations of the C. albicans CYP51 (CACYP51) homology model's catalytic site complexed with 13 was stable demonstrating excellent binding. This article is protected by copyright. All rights reserved

Magnetoresistance of nondegenerate quantum electron channels formed on the surface of superfluid helium

Transport properties of quasi-one-dimensional nondegenerate quantum wires formed on the surface of liquid helium in the presence of a normal magnetic field are studied using the momentum balance equation method and the memory function formalism. The interaction with both kinds of scatterers available (vapor atoms and capillary wave quanta) is considered. We show that unlike classical wires, quantum nondegenerate channels exhibit strong magnetoresistance which increases with lowering the temperature.Comment: 8 pages, 7 figure

Microstructural, Biomechanical, and In Vitro Studies of Ti-Nb-Zr Alloys Fabricated by Powder Metallurgy

Data Availability Statement: The data underpinning this publication can be accessed from Brunel University London’s data repository, Brunelfigshare here under a CCBY licence: https://doi.org/10.17633/rd.brunel.5446813.v1. Non-digital data supporting this study are stored by the corresponding author at Brunel University. Details of how to request access to these data are provided here: https://doi.org/10.17633/rd.brunel.5446813.v1.Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ma16124240/s1, Figure S1: Plasmid–DNA interaction assay for Ti-Nb-Zr based alloys. The migration pattern of plasmid DNA incubated with Ti-Nb-Zr-based alloys and TiRG4 reference materials is shown in the figure. The bands are labeled as NC: Nicked circular and SC: Supercoiled; ddH2O served as a negative control.Copyright © 2023 by the authors. This study investigated the microstructures, mechanical performances, corrosion resistances, and in vitro studies of porous Ti-xNb-10Zr (x: 10 and 20; at. %) alloys. The alloys were fabricated by powder metallurgy with two categories of porosities, i.e., 21–25% and 50–56%, respectively. The space holder technique was employed to generate the high porosities. Microstructural analysis was performed by using various methods including scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction, and x-ray diffraction. Corrosion resistance was assessed via electrochemical polarisation tests, while mechanical behavior was determined by uniaxial compressive tests. In vitro studies, such as cell viability and proliferation, adhesion potential, and genotoxicity, were examined by performing an MTT assay, fibronectin adsorption, and plasmid-DNA interaction assay. Experimental results showed that the alloys had a dual-phase microstructure composed of finely dispersed acicular hcp α-Ti needles in the bcc β-Ti matrix. The ultimate compressive strength ranged from 1019 MPa to 767 MPa for alloys with 21–25% porosities and from 173 MPa to 78 MPa for alloys with 50–56% porosities. Noted that adding a space holder agent played a more critical role in the mechanical behaviors of the alloys compared to adding niobium. The pores were largely open and exhibited irregular shapes, with uniform size distribution, allowing for cell ingrowth. Histological analysis showed that the alloys studied met the biocompatibility criteria required for orthopaedic biomaterial use.EPSRC Future LiME Hub (EP/N007638/1); PhD studentship, the Republic of Turkey Ministry of National Education

SUBURETERIC IMPLANT INJECTION IN THE TREATMENT OF VESICO-URETERAL REFLUX

Amaç: Veziko-üreteral reflünün (VÜR) endoskopik tedavisi son yıllarda birçok çalısmada yüksek basarı oranları sunan popüler tedavi yöntemlerinden biri olmustur. VÜR'un subüreterik enjeksiyon tekniği ile tedavisindeki deneyimimizi sunuyoruz Gereç ve yöntem: Subüreterik enjeksiyon tekniği ile tedavi edilmis yasları 8 ay-16 yas arasındaki 75 hasta 104 reflülü üreter çalısmaya dahil edildi. Subüreterik enjeksiyon tedavisi sistoskopi esliğinde üreter ağzı tabanına submukozal olarak 1-3 cc sodyum hyaluronan içinde dextranomer (Deflux), kalsiyum hidroksilapatit (Coaptite), pirolitik karbon kaplı zirkonyum oksit (Durasphere) veya 0,1-0,9 cc politetrafloroetilen (Teflon) enjeksiyonu yapılarak uygulandı. Hastaların takibinde radyonüklid iseme sistografisi veya konvansiyonel voiding sistoüretrogram (VCUG) yapıldı. Bulgular: Reflü dereceleri I-IV arasındaydı. Enjeksiyon materyali olarak 15 hastada Teflon, 17 hastada Deflux, 26 hastada Coaptite, 17 hastada Durasphere kullanıldı. I.Derece VÜR'de %100, II.derece VÜR'de %87, III.derece VÜR'de %80, IV.derece VÜR'de %68 basarı sağlandı. Toplam basarı oranı %83 olarak bulundu. Enjeksiyon öncesinde ürodinami ile asırı aktif mesane saptanan hastalar oxybutinin HCL ile tedavi edildi. Tembel mesane ve iseme disfonksiyonu olan hastalarda basarı oranı %87,5 bulundu. Asırı aktif mesanesi olan hastalarda basarı oranı %86,6 bulundu. Disfonksiyonel iseme ve asırı aktif mesanesi olan hastalarda basarı oranı %100 bulundu. Reflü derecesi düsük ve asırı aktif mesane olup oxibutinin ile tedavi edilmis hastalarda sonuçların daha basarılı olduğu saptandı. Äslem sonrasında hiçbir hastada obstrüksiyon ve komplikasyon izlenmedi. Sonuç: Vezikoüreteral reflülü hastalarda subüreterik enjeksiyon ile tedavi yönteminde basarıyı reflünün derecesi ve detrusor fonksiyonları etkilemektedir. Subüreterik enjeksiyon yapılacak hastalar bu kriterlere uygun seçildiğinde tedavinin basarı sansını yükselmektedir. Objective: Endoscopic treatment of vesico-ureteral reflux (VUR) has become a popular method with promising results. We herein present our experience with subureteric injection in the treatment of VUR. Material and method: We reviewed the records of 75 patients aged 8 months-16 years who were treated by endoscopic subureteral injection for 104 refluxing ureters. Using a cystoscope subureteral injection was performed by injecting 1.0-3.0 cc dextranomer in sodium hyaluronan (Deflux) or calcium hydroxylapatite (Coaptite) or pyrolytic carbon-coated zirconium oxide beads (Durasphere) or 0.1-0.9 cc politetrafloroetilene (Teflon) to submucosal area in the orifice of ureter. In the follow-up patients were evaluated with radionuclid voiding cystography or conventional voiding cystouretrography (VCUG). Results: Reflux grades were I-IV. The injected implants were Teflon in 15 patients, Deflux in 17 patients, Coaptite in 26 patients and Durasphere in 17 patients. The success rate of SIE was 100% for grade I reflüx, 87% for grade II reflüx, 80% for grade III reflüx and 68% for grade IV reflüx. Overall success rate was 83%. Patients who were evaluated with urodynamic investigations for bladder disfunction. and had over active bladder were treated with oxybutinin HCL. The success rate of SIE was 87,5% for patients with neurogenic bladder with disfunctional voiding, 86.6% patients with over active bladder and 100% patients with disfunctional voiding and over active bladder. Success rate was higher in patients with reflux of lower grade and who were treated with oxybutinin HCL for over active bladder. No treatment-related significant complication such as obstruction was encountered. Conclusion: The success rate of subureteric injection in the treatment of VUR depends on the grade of the reflux and the functions of the detrussor. The success rate of the subureteral injection is higher in patients with these appropriate criterias

LAPAROSCOPIC SPLENECTOMY

Amaç: Çocuklarda çeşitli hastalıklar nedeniyle splenektomi gerekmektedir. Laparoskopik splenektomi (LS) tarif edildikten sonra açık splenektomiye tercih edilmektedir. Laparoskopik splenektomi ile ilgili deneyimlerimizi sunmak istiyoruz. Gereç ve yöntem: 2005-2008 yılları arasında LS yapılan 7 hastanın kayıtları geriye dönük olarak incelendi. Bulgular: LS uygulanan 4 kız, 3 erkek hastanın ortalama yaşı 9,8 ± 3,9 yaş olarak hesaplandı. Splenektomi endikasyonunun 4 hastada herediter sferositoz (HS), 2 hastada idiyopatik trombositopenik purpura (ITP) ve 1 hastada splenik kist olduğu bulundu. Tüm hastalara total LS uygulandı. Ameliyat öncesi abdominopelvik ultrasonografide (US) hiçbir hastada aksesuar dalak görülmedi, HS tanılı 2 hastada ameliyat sırasında dalak hilusunda aksesuar dalak görülerek çıkarıldı. Ameliyat öncesi abdominopelvik US'de HS tanılı 3 hastada kolelitiazis saptandı. Bu hastalara LS öncesinde laparoskopik kolesistektomi (LK) uygulandı. Hiçbir hastada açık splenektomiye geçilmedi. Ameliyat sırasında ve sonrasında komplikasyonla karşılaşılmadı. Ortalama ameliyat süresi LS yapılan hastalarda 132 ± 30 dakika ve LS + LK yapılan hastalarda 170 ± 8 dakika olarak hesaplandı. Ortalama hastanede yatış süresi 2,4 ± 0,5 gün olarak bulundu. Sonuç: Laparoskopik splenektomi çocuklarda güvenli ve başarılı bir yöntem olarak uygulanabilmektedir. Objcetive: Splenectomy is required in children with various diseases. Laparoscopic splenectomy (LS) is preferred than open splenectomy. We herein present our experience with laparoscopic splenectomy. Material and method: The records of 7 patients who underwent LS between 2005- 2008 years were reviewed retrospectively. Results: The mean age of 4 girls and 3 boys who underwent LS was 9.8 ± 3.9 years. The indication for splenectomy was hereditary spherocytosis (HS) (4), idiopathic trombocytopenic purpura (ITP) (2) and splenic cyst (1). All patients underwent total LS.Accessory spleen was identified none of the patients by the preoperative abdominopelvic ultrasonography (US). In 2 patients with HS accessory spleens were detected at the hilus of the spleen during the LS and these patients underwent removal of accessory spleens. Cholelithiasis was identified in 3 patients with HS by the preoperative abdominopelvic US. These patients underwent LS with laparoscopic cholecystectomy (LC). None of the patients required open splenectomy. There were no intraoperative or postoperative complications. The mean duration of surgery for LS was 132 ± 30 min and for LS + LK was 170 ± 8 min. The mean hospital stay was 2.4 ± 0.5 days. Conclusion: Laparoscopic splenectomy can be performed safely and effectively in children