RESUMO
The exploration of synaptic plasticity in metal-oxide-based ferroelectric thin-film transistors has been limited. As a perovskite ferroelectric material, LiNbO3 is widely studied; but its potential use as a neuromorphic device, like synaptic transistors, has not been realized. In this study, a solution-processed ferroelectric thin-film transistor (FeTFT) with an alternating layer of LiNbO3 and Li5AlO4 as a gate dielectric has been fabricated. This configuration reduces the depolarization field by leveraging the large ionic polarization of Li+ ions in the Li5AlO4 layer, while the wide bandgap helps mitigate the leakage current. FeTFT exhibits impressive transistor performance, including a saturation mobility of 0.478 cm2V-1 s-1, an on/off ratio of 3.08 × 103, and a low trap-state density of 1.3 × 1013 cm-2. Moreover, the device demonstrates good memory retention, retaining information for nearly 1 day. It successfully emulates synaptic plasticity, specifically short-term plasticity and long-term plasticity. Besides, a 94% training accuracy has been achieved through artificial neural network simulation. Notably, the FeTFT consumes minimal power, with energy consumption of approximately 3.09 nJ per synaptic event, which is remarkably low compared to other reported solution-processed FeTFT devices.
RESUMO
OBJECTIVE: Telehealth is the use of technology to deliver medical services. Potential uses among veterinarians include consulting with specialists about complicated cases, sending in electronic prescriptions, or meeting with clients to discuss patient health. Although the coronavirus disease 2019 pandemic posed many challenges to the veterinary profession, it accelerated the adoption of telehealth among veterinarians. As many of these changes took place quickly in response to the pandemic, many of those in practice did not receive much training or guidance; therefore, this study explores veterinary students' perceptions regarding incorporating telehealth into the veterinary curriculum and the utilization of telehealth in the future. METHODS: An email survey was sent to students at a veterinary school. RESULTS: 80 students provided answers to the 11-question survey. Nearly 80% reported that it is either "important" or "very important" to incorporate telehealth training into the veterinarian curriculum, whereas almost 90% indicated that they would benefit from more telemedicine training prior to graduation. Almost 75% of participants had legal and malpractice concerns, which may present a barrier to using the technology upon graduation. CONCLUSIONS: This study suggests that veterinary schools should explore how to incorporate telehealth training into their curriculum, especially in regard to navigating the potential pitfalls that may be encountered when employing telehealth within the context of a veterinarian-client-patient relationship. CLINICAL RELEVANCE: Telehealth is a valuable tool, and its use has become commonplace. Educational programs that emphasize telehealth will better equip future clinicians to manage the nuances of this modality in practice.
RESUMO
Large negative photoconductance (NPC) of SnO2/TiO2 nanoparticles (NPs) heterostructure has been observed with thin film transistor (TFT) geometry and has been investigated using sub-bandgap light (blue) illumination. This negative photoconduction has been detected both in accumulation and depletion mode operation, which effectively reduces the carrier mobility (µ) of the TFT. Moreover, the threshold voltage (Vth) widely shifted in the positive direction under illumination. The combined effects of the reduction of mobility and Vth shifting led to a faster reduction of On (or Off) state current under illumination. The negative photosensitivity of this system is as high as 3.2 A W-1, which has been rarely reported in the earlier literature. Moreover, the variation of On (or Off) current, µ and Vth shift is linear with low-intensity blue light. This SnO2/TiO2 NP bilayer channel has been deposited on top of an ionic dielectric (Li-Al2O3) that reduces its operating voltage of this TFT within 2 V. Furthermore, the device has achieved a saturation mobility of 0.4 cm2 V-1 s-1 with an on/off ratio of 7.4 × 103 in the dark. An energy band diagram model has been proposed based on the type-II heterostructure formation between SnO2/TiO2 semiconductors to explain this NPC mechanism. According to the energy band diagram model, adsorbed H2O molecules of TiO2 NPs created a depleted layer in the heterostructure that accelerated the recombination process of photo-generated carriers rather than its transport.
RESUMO
Non-linear optical (NLO) features of 3-[(4-Nitrophenyl Azo)]-9H-Carbazole-9-Ethanol (NPACE) chromophore were investigated by FT-IR, FT-Raman, and UV-visible spectra aided by Density Functional Theory (DFT) using the B3LYP/6-311++G(d,p) basis set of Gaussian 16 W package. It is observed from the DFT calculation that the slight increase in the endocyclic angle of C13 -C14 -C15 and the reduction in exocyclic angle of N40 -N39 -C14 and C15 -C14 -N39 ascertained by experimental XRD values indicating the intramolecular charge-transfer interaction between the carbazole and nitrophenyl group through the diazo bridge. The vibrational contribution to the linear electro-optic effect is 15% of the total hyperpolarizability being calculated at B3LYP/6-311++G (d, p) for the NPACE molecule. It is also observed that the 8a, 19a, and 19b modes of the carbazole ring and the 8a, 8b, and 19b modes of the phenyl ring are found to be simultaneously and intensely active in IR and Raman spectra explaining the charge transfer interactions throughout the molecule. The low value of the HOMO- LUMO energy gap (2.5843 eV) and the deviation between the measured absorption wavelength (3.36 eV) from the computed (3.87 eV), both these facts substantiate the intramolecular charge transfer. The polarizability and first-order hyperpolarizability were calculated as 6.48 × 10-24 and 3.8 × 10-29 esu, respectively. The second harmonic generation (SHG) measurement experiment of NPACE was carried out using the powder method. The SHG efficiency is measured in comparison with the urea standard. The calculated torsional mode at 20 cm-1 is in excellent quantitative agreement with the experimentally determined terahertz absorption peak. The two-photon absorption coefficient of NPACE was estimated to be 0.9 × 10-11 mW-1, which is mainly due to the D-π-A type of molecular structure, and the optical limiting threshold for NPACE was estimated to be 1.52 × 1013 Wm-2 enabling this material as a potential candidate for optical limiting applications.
RESUMO
Introduction Pregnancy-induced hypertension (PIH) is a hypertensive disorder in pregnancy that occurs after 20 weeks of pregnancy in the absence of previously known hypertension. PIH is a common and serious complication accompanying pregnancy. Pre-eclampsia and eclampsia are multisystem disorders that can involve end organs like kidneys, liver, eyes, haematopoietic system and placenta. Though ocular involvement is not uncommon in PIH, ocular examination is not always done in all cases of PIH. Timely detection of changes in retinal vasculature can be a hint to the underlying changes in the vascular system of the various end organs of the human body including placental circulation. Adequate management of PIH is very important for both fetal and maternal well-being. Aim To evaluate the ocular manifestations in women affected by PIH (mild pre-eclampsia, severe pre-eclampsia and eclampsia) presenting to a tertiary-level hospital. Methodology This was a hospital-based cross-sectional study carried out for a period of one year at a tertiary-level hospital. A total of 120 subjects diagnosed as cases of pre-eclampsia/eclampsia admitted to the eclampsia ward of the obstetric unit formed the study population. After taking history, a detailed ocular examination was done for all patients and the findings were noted. Results The mean age of the study population was 31.91 ± 4.38 years (range 21 to 39 years). The mean gestational age was 30.89 ± 3.98 weeks. Fifty-three (44.17%) were primigravida, 64 (53.33%) were multiparous, and three (2.5%) were grand multiparous. Sixty-two (51.67%) had mild pre-eclampsia, 50 (41.67%) had severe pre-eclampsia and eight (6.67%) had eclampsia. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) recorded in the study were 155.32 ± 11.89 mmHg and 104.3 ± 11.41 mmHg respectively. Ocular symptoms were present in 43 (35.83%) participants. Blurring of vision (19.17%) was the commonest ocular symptom observed in the study population followed by photopsia (13.33%), diplopia (9.17%), intermittent loss of vision (5.83%), ocular pain (6.67%), and scotoma (1.67%). Systemic symptoms included headache (11.67%), epigastric pain (3.33%), and nausea (5%). Anterior segment findings like conjunctival congestion, lid edema, and subconjunctival hemorrhage each accounted for 1.67% of the study population. Fundal changes were present in 33.33% of cases. Arteriolar narrowing was the commonest fundal finding amounting to 15.83%, followed by arteriovenous (AV) crossing changes also in 15.83%, cotton wool spots in 5.83%, retinal haemorrhages in 8.33%, papilledema in 2.5%, and choroidal infarcts in 1.67% participants. Grade 1 hypertensive retinopathy was observed in 15.83% of participants, grade 2 in 8.33% of participants, grade 3 in 6.67% of participants and grade 4 in 2.5% of participants. The mean SBP and mean DBP were high among those with fundal changes (163.35 ± 10.25 mmHg and 111.15 ± 10.29 mmHg) compared to those without fundal changes (151.3 ± 10.58 mmHg and 100.88 ± 10.41 mmHg). This was statistically significant. Proteinuria showed significant correlation with retinal changes. Conclusion The retinal vasculature changes correlate with the severity of hypertension, hence, it is very important to seek ophthalmologic opinion for evaluation, diagnosis and prompt management of PIH.
RESUMO
Exosomes, a subtype of the class of extracellular vesicles and nano-sized particles, have a specific membrane structure that makes them an alternative proposition to combat with cancer through slight modification. As constituents of all most all the primary body fluids, exosomes establish the status of intercellular communication. Exosomes have specific proteins/mRNAs and miRNAs which serve as biomarkers, imparting a prognostic tool in clinical and disease pathologies. They have efficient intrinsic targeting potential and efficacy. Engineered exosomes are employed to deliver therapeutic cargos to the targeted tumor cell or the recipient. Exosomes from cancer cells bring about changes in fibroblast via TGFß/Smad pathway, augmenting the tumor growth. These extracellular vesicles are multidimensional in terms of the functions that they perform. We herein discuss the uptake and biogenesis of exosomes, their role in various facets of cancer studies, cell-to-cell communication and modification for therapeutic and diagnostic use.