Device Retention Research Articles

Modeling and Verification of Interface and Bulk Trap Level Density Extraction in SONOS Memory Charge Trapping Layer

Retention characteristics of silicon-oxide-nitride-oxide-silicon (SONOS) nonvolatile memory are affected by properties such as energy level and spatial location. In this study, a model was presented that separately evaluated the bulk and interface trap level density distributions in the SONOS nonvolatile memory charge trapping layer (CTL). This model is proposed in the form of a first-order function of nitride thick XN, so the bulk and interface trap densities, gbulk and ginterface, respectively, can be extracted from the slope and y-intercept. Measurements were performed on various thickness samples. For verification, CTL1 and CTL2 were formed by different processes. The extracted CTL1 gbulk and ginterface are on the order of 1017 cm−3 and 1011 cm−2, and the CTL2 gbulk and ginterface are of the order of 1018 cm−3 and 1012 cm−2, respectively. Using this model, a direction to improve the SONOS device retention characteristics can be suggested.

Magnetic Living Hydrogels for Intestinal Localization, Retention, and Diagnosis

Natural microbial sensing circuits can be rewired into new gene networks to build living sensors that detect and respond to disease-associated biomolecules. However, synthetic living sensors, once ingested, are cleared from the gastrointestinal (GI) tract within 48 hours; retaining devices in the intestinal lumen is prone to intestinal blockage or device migration. To localize synthetic microbes and safely extend their residence in the GI tract for health monitoring and sustained drug release, an ingestible magnetic hydrogel carrier is developed to transport diagnostic microbes to specific intestinal sites. The magnetic living hydrogel is localized and retained by attaching a magnet to the abdominal skin, resisting the peristaltic waves in the intestine. The device retention is validated in a human intestinal phantom and an in vivo rodent model, showing that the ingestible hydrogel maintains the integrated living bacteria for up to seven days, which allows the detection of heme for GI bleeding in the harsh environment of the gut. The retention of microelectronics is also demonstrated by incorporating a temperature sensor into the magnetic hydrogel carrier.

Empirical metal-oxide RRAM device endurance and retention model for deep learning simulations

Memristive devices including resistive random access memory (RRAM) cells are promising nanoscale low-power components projected to facilitate significant improvement in power and speed of Deep Learning (DL) accelerators, if structured in crossbar architectures. However, these devices possess non-ideal endurance and retention properties, which should be modeled efficiently. In this paper, we propose a novel generalized empirical metal-oxide RRAM endurance and retention model for use in large-scale DL simulations. To the best of our knowledge, the proposed model is the first to unify retention-endurance modeling while taking into account time, energy, SET-RESET cycles, device size, and temperature. We compare the model to state-of-the-art and demonstrate its versatility by applying it to experimental data from fabricated devices. Furthermore, we use the model for CIFAR-10 dataset classification using a large-scale deep memristive neural network (DMNN) implementing the MobileNetV2 architecture. Our results show that, even when ignoring other device non-idealities, retention and endurance losses significantly affect the performance of DL networks. Our proposed model and its DL simulations are made publicly available.

Frozen versus fresh corneal graft carriers in Boston keratoprosthesis surgery: 10-year outcomes

ObjectiveTo compare 10-year clinical outcomes of frozen versus fresh corneal graft carriers for the Boston Keratoprosthesis type 1 (KPro). DesignProspective, non-masked randomized controlled trial. ParticipantsNineteen eyes of 19 patients having undergone Boston KPro type 1 implantation using a fresh or frozen graft carrier. MethodsAll patients that underwent Boston KPro type 1 implantation by a single experienced surgeon using an allograft carrier between October 2008 and March 2010 at the Centre Hospitalier de l'Université de Montréal were considered. Patients were excluded if they had a history of prior KPro implantation in the same eye. A subset of the patient cohort enrolled in the initial study protocol of 24 months continued follow-up to 120 months. Participants were randomized to receive either a fresh or frozen corneal graft carrier depending on tissue availability from the eye bank on the day of KPro implantation. ResultsNineteen eyes of 19 patients were included, with 11 in the fresh group and 8 in the frozen group. At 10 years, in the fresh and frozen groups respectively, device retention was 91% and 75%; mean best corrected visual acuity increased from counting fingers preoperatively to 20/300 and 20/125; and incidence of complications per patient was 2.36 and 2.37. There were no statistically significant differences between groups for any of these outcome measures (p > 0.05 for all analyses). ConclusionsFresh and frozen corneal graft carriers offer similar clinical outcomes for KPro implantation in terms of device retention, change in visual acuity, and rate of complications at 10 years.

Management of endophthalmitis related to glaucoma drainage devices: review of the literature and our experience.

Glaucoma drainage device (GDD)-related endophthalmitis is a devastating complication of device implantation. There are no guidelines in the literature to assist clinicians in deciding if the GDD should be explanted or if patients require pars plana vitrectomy (PPV). This study compares the outcomes of GDD explantation with device retention and also independently compares the outcomes of PPV versus intravitreal antibiotics alone in patients with GDD-related endophthalmitis. A literature search for studies discussing GDD-related endophthalmitis from 2005 to 2019 was performed; 30 articles were included. The visual acuity/anatomical outcomes were compared between GDD explantation and retention, and between patients that received a PPV and those that did not. These outcomes were combined with a medical records review of 13 patients with GDD-related endophthalmitis from an academic institution. A total of 88 eyes were included. 70.5% underwent GDD explantation, while 37.8% received a PPV. GDD explantation was associated with a lower rate of evisceration/enucleation when compared to GDD retention (4.8% versus 19.2%, OR 0.22, 95% CI 0.05-1.01, p = 0.05), but visual acuity outcomes were similar. No eyes that received an immediate vitrectomy became phthisic or required evisceration/enucleation, compared an evisceration/enucleation rate of 15.2% in eyes treated solely with intravitreal antibiotics (OR 1.18, 95% CI 1.04-1.33, p = 0.04). Explantation of the GDD and immediate vitrectomy are both associated with better anatomical outcomes in GDD-related endophthalmitis. Further research is needed to provide more definitive guidelines in the ideal management of these patients.

High-Performance Radiation-Hardened Spintronic Retention Latch and Flip-Flop for Highly Reliable Processors

Radiation vulnerability and high power density are critical challenges in modern CMOS processors. Spin-based devices like magnetic tunnel junction (MTJ) are among the promising alternatives for addressing these challenges thanks to their fascinating properties such as radiation immunity, non-volatility, high endurance, and compatibility with the CMOS fabrication process. Utilizing the fascinating non-volatile property of the MTJ device, a high-performance, and energy-efficient soft error immune retention latch, and a high-reliable non-volatile flip-flop (FF) are proposed in this paper. Thanks to the single event upset (SEU) immunity, the proposed circuits are applicable in designing highly reliable processors, especially in applications like aerospace systems, where immunity to radiation induced soft errors is very critical. Because of the innovative design of the proposed approach, the MTJ switching delay does not affect the performance of the proposed latch. The simulation results indicate that the proposed latch offers lower delay, power consumption, and power delay product (PDP) than the state-of-the-art designs. The results of the comprehensive Monte-Carlo simulations also demonstrate that the proposed approach is more robust to process, voltage, and temperature variations as compared to their previous counterparts. This is because our designs do not use a pre-charge sense amplifier (PCSA) to read the data stored in the MTJs, and hence, the proposed designs have lower error rates. Furthermore, the transient impact of the particle strikes on the internal nodes is not transferred to the output node of the proposed circuits. The proposed design also has a significantly shorter output recovery time compared to its state-of-the-art counterparts.

Trade-off between variability and retention of memristive epitaxial SrTiO3 devices

We present a study of the trade-off between the retention and variability of SrTiO3-based memristive devices. We identified the applied switching current and the device stoichiometry as main influence factors. We show that the SrO formation at the electrode interface, which has been revealed to improve the device retention significantly, is associated with an increased cycle-to-cycle and device-to-device variability. On the other hand, devices with homogeneous, Ti-terminated SrTiO3–Pt interfaces exhibit poor retention but the smallest variability. These results give valuable insights for the application of memristive SrTiO3 devices as non-volatile memory or in neural networks, where the control of variability is of key relevance.

Complications During Grayson Presurgical Nasoalveolar Molding Method in Nonsyndromic Infants With Complete Unilateral Cleft Lip and Palate.

Within the treatment protocols of patients with cleft lip and palate, the nasoalveolar molding (NAM) acquire more followers every day.Their benefits have been well documented, but not equally their complications. The purpose of this study was to describe the complications produced during treatment with Grayson presurgical NAM in nonsyndromic infants with complete unilateral cleft lip and palate. Bibliographic review on 8 databases using search algorithms. By applying the exclusion and inclusion criteria, 21 articles were detected, which were analyzed in full text. Complication, cause, and solution data were presented in supplemental tables. Complications are related to soft tissues, hard tissues, and those derived from care. irritation, ulceration, gingival, facial, or nasal bleeding. Candidiasis. An overexpanded nostril creation to improper placement or modifications of the nasal stent at home.The most frequent were lip and cheeks skin irritation by taping, and gingival ulceration due to excessive pressure. misalignment of alveolar segments and the premature eruption of teeth. inadequate device retention, adherence problems to treatment, poor/excessive care of the caregiver, intolerance to the device, eating problems, breathing, and socioeconomic issues. The main complications occur in soft tissues, related to the retention mechanisms and an inadequate adjustment of the device.The benefits of NAM exceed the complications. It is necessary to know them to avoid any harmful results since they could prolong or stop the treatment, compromising the result. The active collaboration of the family in the insertion and maintenance of the device is crucial for success.

Extending the Color Retention of an Electrochromic Device by Immobilizing Color Switching and Ion-Storage Complementary Layers

The thermal polymerization of a bis(triphenylamine)-bis(styrene) monomer on ITO coated glass gave an electroactive film that underwent two stepwise oxidations. The perceived color change of the film upon stepwise oxidation was colorless-to-yellow followed by yellow-to-blue. The anodic cyclic voltammogram of the monomer was consistent over multiple cycles. The immobilized film could be reversibly switched between its colorless and blue states with applied potential in both a half- and full-electrochromic functioning device. The devices could also reversibly switch their colors upwards of 6 h. The retention of the electrochemically induced blue color was contingent on the device architecture. Upwards of 80% of the color was maintained 30 min after the potential was turned off with the double-layer electrochromic device structure. This device was prepared from two electroactive layers: a bis(triphenylamine) and viologen-based polymers that were immobilized on the electrodes. In contrast, 50% of the color of the active electrochromic device that was prepared from a single electroactive layer bleached 7 min once the potential was no longer applied.

Efficacité d’un traitement intravaginal à base de progestérone chez des vaches croisées <em> Bos indicus </em> x <em> Bos taurus </em>

L’étude a eu pour objectif d’évaluer l’efficacité d’un traitement combiné à base de progestérone intravaginale sur l’induction de l’oestrus de femelles croisées au Cameroun. Un total de 116 vaches Goudali (Bos indicus) x Charolaises (Bos taurus) ayant mis bas au moins une fois, sans antécédent pathologique, avec une note d’état corporel supérieure à 2, ont été sélectionnées dans des élevages du département de la Vina (arrondissement de Nyambaka). Elles ont été rassemblées dans un ranch et réparties en lots de 10 animaux. Le protocole d’induction et de synchronisation des chaleurs a consisté en la pose d’un dispositif intravaginal à base de progestérone (Prid Delta) pendant huit à neuf jours. Vingt-quatre heures avant son retrait, une injection de cinq millilitres de prostaglandine F2alpha (Dinoprost, Enzaprost) a été administrée. Au moment du retrait, 500 UI de gonadotropine chorionique équine ont été injectées. Cinquante-six heures après le retrait, l’insémination a été effectuée à heure fixe avec de la semence de taureaux Gyr et Brahman. Les taux d’induction de l’oestrus et de synchronisation, de rétention du dispositif intravaginal, de gravidité en première insémination, de fécondité, et d’avortement ont été respectivement de 100 %, 100 %, 56,0 %, 51,7 %, et 4,3 % (en % des vaches traitées). Le Prid Delta s’est révélé efficace pour l’induction des chaleurs et l’obtention de gravidités chez les vaches Goudali x Charolaises.

A highly stretchable and deformation-insensitive bionic electronic exteroceptive neural sensor for human-machine interfaces

Bionic integrated sensing devices with numerous distributed electronic elements substantially expand the human’s interactive control capabilities. Several difficulties need to be overcome, including intricate interconnections, complicated structures, and electromagnetic interference/compatibility in signal transmission. In addition, retention of device’s functionalities under high deformation is desired, while it faces huge challenges to achieve stretchability and deformation insensitivity. Herein, a highly stretchable and deformation-insensitive bionic electronic exteroceptive neural sensor is first presented and fabricated from the functional composite of polyester thread coated with carbon nanotubes. The bionic electronic exteroceptive neural sensor features all-in-one bionic multifunctional characteristics, which effectively avoids the use of numerous distributed electronic elements. Importantly, it achieves high stretchability and characterizes unprecedented deformation-insensitive functional property. The properties enable the bionic electronic exteroceptive neural sensor to serve as a wearable device and function continuously without interference even when being greatly stretched (100% strain). Other prominent advantages of the bionic electronic exteroceptive neural sensor are excellent stability (> 15,000 cyclical tests), rapid response (≤ 15 ms), high robustness, geometrically hierarchical sensing, and personalized cuttability. The tremendous potential applications of the bionic electronic exteroceptive neural sensor are demonstrated in the fields of human-machine interactions, information security system, and Internet of things.

Impact of La–OH bonds on the retention of Co/LaSiO CBRAM

Co/LaSiO conducting bridge random access memory is a promising candidate for low power storage class memories due to its high endurance and short switching pulse width. Moisture has been hypothesized to be an important parameter in determining device retention. In this study, we anneal the LaSiO layers at different temperatures and pressures in order to reduce the absorbed moisture and improve retention. We evidence by Fourier transform infrared and x-ray reflectivity that the moisture content does not change with these anneal conditions. However, we find that increasing the amount of La–OH bonds is an effective way to improve the low resistance state retention.

Outcomes and complications of Boston keratoprosthesis type I implantation in unilateral versus bilateral corneal blindness

ObjectiveTo compare the outcomes of Boston keratoprosthesis (KPro) type I implantation between patients who are legally blind versus sighted in the contralateral eye. DesignSingle centre retrospective comparative case series. ParticipantsPatients who underwent Boston KPro type I implantation between 2008 and 2017. MethodsSingle-center retrospective comparative case series. Patients were divided into 2 groups based on the preoperative best-corrected visual acuity (BCVA) in the contralateral eye: group I (>20/200) and group II (20/200). Main outcome measuresPostoperative BCVA, device retention, and complications. ResultsGroup I (56 eyes) and group II (53 eyes) had similar demographics, median preoperative BCVA (hand movements) in the operated eye, and median duration of postoperative follow-up (76.92 vs 85.6 months, respectively). Final postoperative BCVA of the operated eye was statistically better in group I compared with group II (20/400 and hand movements, respectively, p = 0.03). There was no statistical significance in device retention mean survival time. The most common complication in both groups was retroprosthetic membrane. Cystoid macular edema occurred more frequently in group I (p = 0.004), whereas retinal detachment was more common in group II (p = 0.052). ConclusionsMost patients who underwent Boston KPro type I implantation experienced an improvement in their vision, with final BCVA being superior in the unilateral blind group. Despite similar complication rates and device retention, there are additional socioeconomic factors that need to be considered in sighted individuals. Because the prognosis is tied to the underlying etiology, it is important to recognize that some diagnoses may influence a better outcome.

DEVELOPMENT OF A PORTABLE HOUSEHOLD WATER DEVICE FOR IMPROVING DRINKING WATER QUALITY IN NIGERIA

Pipe borne water supplied to Nigerian households may not always meet the accepted drinking water quality standards due to possible water pipe damage. The objective of this study was, therefore, to develop a portable water filter device for improving household drinking water quality. Five litres of representative tap water samples collected from Lagos State University Staff quarters were passed through the developed device. The experimental variables investigated for data acquisition were aeration period of untreated tap water; device backwashing operation cycles and retention times of tap water in the filter device. The results of the analyses of water samples for the various values of the experimental variables showed that the range values of water parameters between the treated and untreated tap water samples were 0.04-0.05, 0.02-0.03, 0.04-0.12, 0.3-0.4, 125-137, 10-20, 3-10 mg/L for barium, chromium, iron, pH, Total Dissolved Solids, hardness and chloride, respectively. Although the developed device helped in improving the quality of the tap water; the p-values for the different experimental variables were greater than α-level of 0.05 indicating the non-significance of using the developed water device. Consequently, future study will consider other experimental variables that will justify the significance of using the developed device.

Non-equivalent Tl doping for high performance perovskite solar cells: Crystal quality improvement with enhanced p-type character

Organic–inorganic hybrid perovskite solar cells, whose highest power conversion efficiency (PCE) already exceeds 25%, have been attracting considerable attention. However, there are still various challenges, such as their low repeatability, large number of intrinsic defects, and low environmental stability. In this study, we dope monovalent thallium (Tl+) into the precursor to form a pinhole-free perovskite film with improved photo-voltaic performance and environmental stability. The incorporation of Tl+ into CH3NH3PbI3 can improve the crystal quality of perovskite film by adjusting the rate of crystalline growth. Due to the non-equivalent doping of Tl+, the Fermi level is lowered by 0.31 eV toward the highest occupied molecular orbital, indicating that Tl behaves as a p-type dopant. An improved carrier dynamics and balanced charge transportation can be observed in MAPb0.99Tl0.01I3. After the doping of 1 mol% Tl into the perovskite film, the average PCE of the cells is increased from 15.1 to 17.8%. Furthermore, the thallium-doped perovskite solar cell exhibits outstanding environmental stability because of the improved moisture resistance. After 200 h of storage under ambient conditions, the Tl-doped perovskite solar cell retains 82.7% of its initial power conversion efficiency, which is higher than the retention of the intrinsic perovskite device (55.9%).

Defective 3D nitrogen-doped carbon nanotube-carbon fibre networks for high-performance supercapacitor: Transformative role of nitrogen-doping from surface-confined to diffusive kinetics

This work demonstrates hierarchical 3D nitrogen-doped carbon nanotube-carbon fibre (N-CNT@CF) networks obtained via a two-step synthetic technique: electrospinning and chemical vapour deposition (CVD) methods. Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) reveal randomly entangled networks structure. Raman spectroscopy show structural defects, X-ray Diffraction spectroscopy (XRD) confirm the purity of the materials, while BET analysis show increase in surface area after nitrogen doping. Electrochemistry reveals that nitrogen-doping transforms surface-confined to diffusion-confined energy-storage mechanism (i.e., high power) even at low cycling rate, significantly increasing the specific capacitance of the symmetric device (155 F/g), specific energy (5.5 Whkg−1), specific power (254 W kg−1) and capacitance retention of 93% even after 10,000 cycles at 10 Ag−1. The N-CNT@CF-based symmetric cell exhibits higher fo value (ca. 82 Hz, response time,τ, of 12 ms) than the CNT@CF-based cell (ca. 25.1 Hz, 40 ms). The excellent performance of N-CNT@CF hybrid material is attributed to the Faradaic charge contribution arising from synergistic interaction between the nitrogen-doped carbon nanotubes and carbon nanofibers, high conductivity, high surface area coupled with enough accessible active sites for electrochemical reactions. This work underscores the importance of defect engineering and decoration of the vacant sites by nitrogen for enhanced supercapacitance.

Predictive factors of Boston Type I Keratoprosthesis outcomes: A long-term analysis

PurposeTo study the long-term visual- and device retention-related outcomes and complications of the Boston Type I Keratoprosthesis (KPro). MethodsSingle-center, retrospective cohort study of all patients undergoing KPro implantation from February 2007 to April 2014 with at least 5 years of follow-up. Results68 eyes from 65 patients underwent KPro implantation during the study period. At 5 and 10 years, the probability of maintaining or improving visual acuity (VA) was 75.0% and 66.7%, respectively, and the probability of KPro retention was 89.2% and 89.2%, respectively. Initial device retention rate at 10 years was significantly lower in those with underlying ocular surface disease (46.8% [30.6–63.2] vs 75.8% [61.0–90.7], P = 0.03), while other baseline characteristics showed no significant association. Final VA was more likely to be stable or improved in patients with fewer failed grafts (2 [1–6] vs 3 [1–6], P < 0.01), and a final VA of 20/200 or better was more likely in primary KPro eyes (44.8% [26.7–62.9] vs 19.4% [6.5–32.3], P = 0.03). Combined KPro-vitrectomy eyes were more likely to have stable or improved final VA than non-vitrectomy eyes (88.5% [76.2–100.0] vs 64.1% [49.1–79.1], P = 0.04). All complications had increasing incidence beyond 5 years; in particular, corneal melt, surgical glaucoma interventions, and endophthalmitis tended to have late presentations, with 79.0%, 78.6%, and 88.9% of these complications occurring beyond one year, respectively. ConclusionsKPro devices show favorable long-term visual and retention outcomes in select patients. Careful long-term, multidisciplinary follow-up is warranted to address potential complications.

Interplay Between Switching and Retention in HfO2-Based Ferroelectric FETs

Long data retention is a critical requirement for many of the potential applications of HfO2-based ferroelectric field-effect transistors (FeFETs). However, methods for its rapid assessment are still missing. In this article, we report a detailed investigation of the retention and switching properties of FeFETs fabricated in the 28-nm high- ${k}$ metal gate technology. We identify a clear correlation between the two properties and propose a method for fast prediction of the device retention behavior, which can be easily adopted to judge different fabrication processes. Finally, we extend the validity of the method to a direct assessment of disturb-free operating conditions, which may be particularly valuable for FeFET array operation.

Web Revisitation using Content and Context Tokens

Right now, the Internet is the most common medium people use to obtain access to knowledge. One's requirements vary from a single word sense to specialized papers and self-education. Revisiting previously visited web pages is one of the most common and unpleasant activities a person does. In fact, a significant primary feedback technique is included in tailoring the individual's memory of vigor and re-examination patterns. Our successful control of environment and object recollections, including decay and reinforcing techniques, may imitate device retention and retention mechanisms. This proposed solution takes into consideration the normal human retrieval method of utilizing episodic and textual memory signals for fast retrieval and includes a different site revisitation mechanism known as the "Web Page Preview" via meaning and information gained through user discovery and web page visits. The underlying methods for the collection, preservation, degradation and usage of meaning and quality of consumer memories for page re-discovery are addressed. Our 3 month user study says that of the time, location, and activity context factors in Web Page Prep, activity is the best recall guide, and context + content based re-discovery provides the highest results relative to context and content individual rediscovery. This concept, if completed, can be used to improve web surfing functionality by providing users a variety of apps with a rather simple UI.

Exploring Balloon Sinuplasty Adverse Events With the Innovative OpenFDA Database.

Balloon sinuplasty (BSP) has become a common, minimally invasive treatment for chronic sinusitis. Like any surgical procedure, there are definite risks when using it as a stand-alone procedure or in conjunction with other revision procedures. To explore the adverse events of BSP using the openFDA cloud with regard to malfunction and injury following surgery. Between January 2015 and December 2018, the Food and Drug Administration's (FDA) openFDA database was queried for adverse event use. Reports were further categorized by procedure location, injury type, device malfunction, procedure (stand-alone BSP vs hybrid), and source of complication (anatomical or surgeon related). Seventy-eight events were reported to the FDA in the study period. Majority of cases consisted of device malfunctions (64.1%), while patient injuries consisted of 43.5%. Frontal sinus procedures had the greatest presence of adverse events (47.4%) with the majority reporting significant cerebrospinal fluid (CSF) leaks (P < .001) and device retention (P = .021). Orbital complications (P = .004) were found to be significantly associated with dilation of the maxillary sinus. Skull-based injuries were the only factor incident in which surgeon-reported anatomical complications were significant (P = .018). As balloon dilation procedure continues to rise in the United States, significant adverse events continue to occur. Frontal sinus BSP leads to the highest number of complications and a 4.75 reported CSF leaks yearly. Based on real data, surgeons performing the procedure should be acquainted with common BSP-related injuries so they can prepare for those circumstances and share informed consent with their patients.