Voltage-time dilemma and stochastic threshold voltage variation in pure silver atomic switches

The formation and dissolution of silver nanowires plays a fundamental role in a broad range of resistive switching devices, fundamentally relying on the electrochemical metallization phenomenon. It was shown, however, that resistive switching may also appear in pure metallic nanowires lacking any silver-ion-hosting embedding environment, but this pure atomic switching mechanism fundamentally differs from the conventional electrochemical-metallization-based resistive switching. To facilitate the quantitative description of the former phenomenon, we investigate broad range of Ag atomic junctions with a special focus on the frequency-dependence and the fundamentally stochastic cycle-to-cycle variation of the switching threshold voltage. These devices are established in an ultra-high purity environment where electrochemical metallization can be excluded. The measured characteristics are successfully described by a vibrational pumping model, yielding consistent predictions for the weak frequency dependence and the large variance of the switching threshold voltage. We also demonstrate that electrochemical-metallization-based resistive switching and pure atomic switching may appear in the same device structure, and therefore the proper understanding of the pure atomic switching mechanism has a distinguished importance in silver-based electrochemical metallization cells

Az invazív urothelsejtes carcinoma morfológiai variánsai

Az urothelsejtes carcinoma a húgyutak leggyakoribb rosszindulatú daganata, amely a vesemedencében, a húgyvezetékben, a húgyhólyagban és ritkán a húgycsőben alakul ki. Szövetileg az urothelsejtes carcinomát nem invazív, illetve invazív kategóriába soroljuk. Az előbbi papillaris növekedésű, általában jól differenciált és kedvező kimenetelű, míg az utóbbi infiltratívan szűri be a kiindulási szerveket, jellemzően rosszul differenciált, és gyakran rossz prognózissal társul. Invazív urothelsejtes carcinoma esetén a kórlefolyást elsődlegesen az invázió mélysége határozza meg, az újabb adatok szerint viszont az urothelsejtes carcinoma morfológiai variánsai eltérően reagálnak az onkológiai kezelésekre, továbbá ezek biológiai viselkedése is különböző. Ezek az altípusok és variánsok hazánkban, illetve nemzetközileg is jelentősen aluldiagnosztizáltak, ugyanis a szövettani kórisme kritériumai sok esetben nem egyértelműek. A húgyúti daganatok legfrissebb, 2022. évi WHO-klasszifikációja jelentősen pontosította az egyes altípusok és variánsok definícióit. Ebben a dolgozatban az aktuális klasszifikációból kiindulva áttekintjük ezen altípusok, illetve variánsok morfológiai, immunhisztokémiai, differenciáldiagnosztikai, prognosztikai és prediktív jellemzőit azzal a céllal, hogy ezek minél inkább megjelenjenek a mindennapi diagnosztikában. A munka célja továbbá az urothelsejtes carcinoma egyes altípusainak és variánsainak bemutatása a hazai patológus-, onkológus- és urológusközösségnek azért, hogy az eddigi magas szintű uroonkológiai ellátás még inkább személyre szabottá válhasson. Orv Hetil. 2023; 164(40): 1567–1582

Conception and reality: outcome of SARS-CoV-2 infection and vaccination among Hungarian IBD patients on biologic treatments

Inflammatory bowel disease potentially elevates the risk of infections, independently from age, while the disease activity and medical treatment(s) can also increase the risks. Nevertheless, it is necessary to clarify these preconceptions as well during the COVID-19 pandemic.An observational, questionnaire based study was conducted in Hungary between February and August 2021. 2 questionnaires were completed. The first questionnaire surveyed the impact of the pandemic on patients with biologic treatments and assessed the severity and outcome of the infection, whereas the second one assessed vaccination rate and adverse events.472 patients participated in the study. 16.9% of them acquired the infection and 6.3% needed hospitalization. None of them required ICU care. Male sex elevated the risk of infection (p=0.008), while glove (p=0.02) and mask wearing (p=0.005) was the most effective prevention strategy. Nevertheless, abstaining from community visits or workplace did not have an impact on the infection rate. Smoking, age, and disease type did not elevate the risk. UC patients had poorer condition during the infection (p=0.003); furthermore, the disease activity could potentially worsen the course of infection (p=0.072). The different biological treatments were equally safe; no difference was observed in the infection rate, course of COVID-19. Azathioprine and corticosteroids did not elevate the infection rate. 28 patients (35.0%) suspended the ongoing biologic treatment, but it had no impact on the disease course. However, it resulted in changing the current treatment (p=0.004). 9.8% of the respondents were sceptic about being vaccinated, and 90% got vaccinated. In one case, a serious flare-up occurred.Most patients acquired the infection at workplace. Biologic therapies had no effect on the COVID-19 infection, whereas male sex, an active disease, and UC could be larger threat than treatments. Vaccination was proved to be safe, and patient education is important to achieve mass vaccination of the population

Voltage-time dilemma and stochastic threshold-voltage variation in pure-silver atomic switches

The formation and dissolution of silver nanowires plays a fundamental role in a broad range of resistive-switching devices, which fundamentally rely on the electrochemical-metallization phenomenon. It has been shown that resistive switching may also appear in pure metallic nanowires lacking any silver-ion-hosting embedding environment but this pure atomic switching mechanism differs fundamentally from the conventional electrochemical-metallization-based resistive switching. To facilitate the quantitative description of the former phenomenon, we investigate a broad range of Ag atomic junctions, with a special focus on the frequency dependence and the fundamentally stochastic cycle-to-cycle variation of the switching-threshold voltage. These devices are established in an ultrahigh-purity environment in which electrochemical metallization can be excluded. The measured characteristics are successfully described by a vibrational-pumping model, yielding consistent predictions for the weak frequency dependence and the large variance of the switching-threshold voltage. We also demonstrate that electrochemical-metallization-based resistive switching and pure atomic switching may appear in the same device structure and therefore the proper understanding of the pure atomic switching mechanism has a very relevant importance in silver-based electrochemical-metallization cells. © 2024 American Physical Society