Search

Halide perovskites (HPs) are promising materials for memristor devices because of their unique characteristics. In this study, nonvolatile resistive switching memory devices based on thick MAPbI3 perovskite (800 nm) films with structure FTO/MAPbI3/polymethyl methacrylate (PMMA)/Ag are presented. Reproducible and reliable bipolar switching characteristics are demonstrated with an ultra‐low operating voltage (−0.1 V), high ON/OFF ratio (106), endurance (>2 × 103 times) and a record retention time (>105 s). The I–V curve of the first cycle exhibits self‐formed conductive filaments. These are attributed to the presence of metallic Pb resulting from an excess of PbI2 in the perovskite film. The subsequent activation process involves the formation of conductive filaments, consisting of either iodide vacancies or migrated charged metals. Numerical simulations are then carried out to understand the nature of these conductive filaments and the role of the internal electric field in the migration of iodide ions, iodide vacancies, and Ag cations. Finally, an exhaustive model is proposed that explains the set and reset processes governing the first voltage cycle and the steady state, at different voltage ranges. In summary, this work offers a novel and thorough perspective of the complete resistive switching (RS) behavior in a MAPbI3/buffer/Ag memristor, supported by numerical simulations. [ABSTRACT FROM AUTHOR]

BackgroundObjectivesMethodsResultsConclusionsSensorimotor dysfunction, as measured by tactile acuity and active joint repositioning, has been identified as a contributing factor of chronic low back pain (CLBP). Existing research suggests that further research is necessary to improve the characterization of sensorimotor perception in patients with CLBP.The main aim is to investigate whether tactile acuity and repositioning errors differ between individuals with CLBP and controls without CLBP. A secondary aim was to investigate the association between age, body mass index (BMI) and physical activity, and tactile acuity and repositioning sense.Cross-sectional study. Sixty-eight participants (36 with, 32 without CLBP) were examined. Two-Point Discrimination (TPD) test (four measures: horizontal and vertical run, left and right side) and Active Joint Reposition Sense (AJRS) test (2 directions: to flexion and to extension) were used.No differences were found for TPD (right horizontal run: p = .069; left horizontal run: p = .066; right vertical run: p = .933; left vertical run: p = .285) or AJRS (flexion: p = .792; extension: p = .956) between participants with and without CLBP. Older subjects had significantly worse tactile acuity (3 sites, p = .018, p = .004, p = .041) and worse repositioning sense (2 directions, p = .026, p = .040,) than younger subjects. Individuals with BMI ≥ 25 had significantly worse TPD compared to individuals with normal weight (2 sites, p = .028, p = .020).Individuals with CLBP did not have impaired tactile and repositioning accuracy when compared to controls without CLBP. Future studies comparing sensorimotor performance should consider age and BMI as potential confounding factors. [ABSTRACT FROM AUTHOR]

Background: Currently, for in vitro embryo production in live mares, immature oocytes are retrieved by transvaginal follicular aspiration or ovum pick up (OPU). Occasionally, ovarian abscesses have been described after OPU, but no current consensus exists on how to treat this condition. Objectives: To describe diagnosis and successful treatment of ovarian abscesses in two mares subjected to OPU. Study design: Case report. Methods: Case records were reviewed and summarised. Results: In the first case, a pony mare showed tachypnoea, tachycardia, high temperature, leukocytosis, left hindlimb lameness and slight increase in concentration of serum amyloid A. Ultrasonography revealed an increase in the size of the left ovary and two well defined structures suggestive of ovarian abscess. A left ovariectomy by standing laparoscopy was the treatment of choice: the diagnosis was confirmed, and bacterial culture produced heavy growth of Streptococcus equi Zooepidemicus. In the second mare, an abnormal structure was observed in the left ovary in a routine transrectal ultrasonographic exam in the absence of any clinical signs or abnormal blood parameters. A medical approach was chosen and a sample of the purulent material was aspirated with a transvaginal ultrasound‐guided approach. The sample yielded a heavy growth of Streptococcus equi Zooepidemicus after culture. Treatment was initiated with rifampicin and trimethoprim—sulfadiazine based on the antibiogram results and the abscess completely resolved after 40 days. Main limitations: Limited to two cases. Conclusions: Ovarian abscesses in mares can be successfully treated both surgically and medically. [ABSTRACT FROM AUTHOR]

Limitations in diagnostic test performance are one of the major challenges hampering the eradication of bovine tuberculosis (bTB). Non-tuberculous mycobacteria (NTM) are considered one of the main causes of non-specific reactions in the intradermal tuberculin test, the most widely used bTB diagnostic test. To determine the role of NTMs in bTB misdiagnosis in Spain, an experimental study including the NTM species most commonly found in bTB-positive animals from bTB-free farms in the country (M. avium subsp. avium (Maa), "Mycobacterium avium subsp. hominissuis" (Mah), M. bourgelatii, M. intermedium, M. kansasii and M. nonchromogenicum) was carried out on guinea pigs and cattle. First, guinea pigs were sensitized with the selected NTMs, and six weeks post-sensitization four antigen mixtures (bovine-PPD, avian-PPD, P22 and ESAT6-CFP10) were inoculated intradermally and their effect was measured 24- and 48-h post-inoculation. Larger erythematous reactions were observed in guinea pigs sensitized with Mah, M. kansasii, and Maa, with significant differences in the reactions measured at the bovine-PPD inoculation site for the two first bacteria compared with other NTMs. The sensitization process was repeated in cattle, and five months post-sensitization the same antigen mixtures were inoculated in the cervical region and responses were measured at 48- and 72-h post-inoculation. A significantly higher increase in the skinfold thickness measured at the bovine-PPD inoculation site was observed in calves sensitized with Mah, Maa, M. intermedium and M. kansasii. These results demonstrate that certain NTM species may play a more significant role in bTB diagnostic interferences and show that results obtained in guinea pig and bovine models do not always coincide., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)