Retention Failure Research Articles

POSTOPERATIVE POSTERIOR SEGMENT COMPLICATIONS AFTER BOSTON TYPE 1 KERATOPROSTHESIS: Incidence, Risk Factors, and Intermediate-Term Outcomes.

To identify the incidence of, risk factors for, and outcomes of posterior segment complications (PSC) after Boston Type 1 keratoprosthesis (KPro) implantation. Retrospective, consecutive case series of KPro procedures at the Stein Eye Institute. Data regarding ocular history, intraoperative details, postoperative management, and outcomes were collected. Eyes with at least one PSC (PSC group) were compared with eyes without PSC (No PSC group), and risk factors for PSC were determined. Ninety-five PSC occurred in 69/169 eyes (40.8%), at a mean of 20.1 months after KPro implantation (0.01 complications/eye month). The median follow-up after KPro implantation was 44.0 months (range 3.0-174.4). The most common PSC were epiretinal membrane (16.6%), cystoid macular edema (12.4%), vitritis (11.2%), and retinal detachment (9.5%). Previous retinal detachment repair, concomitant intraocular lens removal, postoperative aphakia, and vitritis were risk factors for retinal detachment. Postoperative infectious keratitis was a risk factor for epiretinal membrane, cystoid macular edema, and vitritis. The posterior segment complication group had a significantly higher rate of eyes failing to maintain visual acuity ≥20/200 (HR = 2.28; 95% CI = 1.35-3.85) and KPro retention failure rate (HR = 1.66; 95% CI = 0.95-2.91). Posterior segment complications occur in approximately 40% of eyes after KPro implantation, resulting in reduced visual outcomes and KPro retention.

A Consistent Model for Short-Term Instability and Long-Term Retention in Filamentary Oxide-Based Memristive Devices.

Major challenges concerning the reliability of resistive switching random access memories based on the valence change mechanism (VCM) are short-term instability and long-term retention failure of the programmed resistance state, particularly in the high resistive state. On the one hand, read noise limits the reliability of VCMs via comparatively small current jumps especially when looking at the statistics of millions of cells that are needed for industrial applications. Additionally, shaping algorithms aiming for an enlargement of the read window are observed to have no lasting effect. On the other hand, long-term retention failures limiting the lifetime of the programmed resistance states need to be overcome. The physical origin of these phenomena is still under debate and needs to be understood much better. In this work, we present a three-dimensional kinetic Monte Carlo simulation model where we implemented diffusion-limiting domains to the oxide layer of the VCM cell. We demonstrate that our model can explain both instability and retention failure consistently by the same physical processes. Further, we find that the random diffusion of oxygen vacancies plays an important role regarding the reliability of VCMs and can explain instability phenomena as the shaping failure as well as the long-term retention failure in our model. Additionally, the results of the simulations are compared with experimental data of read noise and retention investigations on ZrO2-based VCM devices.

Patients, Social Workers, and Pharmacists' Perceptions of Barriers to Providing HIV Care in Community Pharmacies in the United States.

Retaining people living with HIV (PLWH) in clinical care is a global priority to end the HIV epidemic. Community pharmacies in the United States have structural influences on the success or failure of retention in HIV care by supporting patients’ complex needs. However, to date, barriers to retention in care in the community pharmacy setting have not been examined beyond pharmacy services of medication therapy management. We utilized the patient-centered medical home model to examine the barriers to HIV care in the community pharmacy setting. We utilized semi-structured interviews to collect data from 15 participants: five PLWH, five community pharmacists, and five social workers from a midwestern state. Interview data were transcribed and analyzed using directed content analysis. Four key themes emerged regarding the barriers that impact utilization of community pharmacy services by PLWH: the perception of the role of community pharmacists in HIV care, perceptions of pharmacists’ HIV knowledge, perceptions of pharmacy operation and services, and negative experiences within the community pharmacy space. Participants’ perceptions of solutions for improving HIV care in the community pharmacy focused on improving the relationship between pharmacists and patients, ensuring that the community pharmacy is a private and safe space for patients, and having a diverse pharmacy staff that is equipped to take care of the diverse and marginalized HIV population, such as transgender people.

Cradle-to-Prison Pipeline

Youth who experience academic failure are at a greater risk for involvement in delinquency. While studies have revealed a myriad of factors for such failure, the perceptions of these youth regarding their educational experiences have proven to be one of the most valuable resources regarding the systematic barriers to academic achievement. The purpose of this essay is to examine how youth of color are overwhelming affected by a phenomenon known as Cradle-to-Prison Pipeline. Several school districts in the U. S. employ harsh discipline practices that inevitably push students out of classrooms, on the streets, and in the juvenile justice system at an astounding rate. Students of color experience higher rates of suspensions, expulsion, truancy, retention, and academic failure in schools. Harsh discipline polices, along with bias and discrimination have a direct or indirect impact on their academic journey, including feeling of inferiority due to their academic shortcomings.
 *The original version of this article included the term Native Indigenous students. Per the authors request, the term Native Indigenous has been replaced with Indigenous.

Outcomes of Transurethral Resection of Prostate in Patients with and without Renal Failure Secondary to an Enlarged Prostate.

The natural history of benign enlargement of the prostate is variable and ranges from mild symptoms to chronic retention and renal failure. In this study, the outcomes of patients with urinary retention alone were compared with those of chronic retention and renal failure caused by an enlarged prostate. The first group had 79, while the second group had 20 patients included. The mean maximum flow rate after transurethral resection of the prostate (TURP) in the two groups was 16.9 ± 7.9 vs. 14.6 ± 4.1 ml/sec (p value > 0.05), and the mean post-void volume was 15.1 ± 27.6 vs. 21.7 ± 35.7 ml (p value > 0.05), respectively. However, the residual symptoms after surgery were higher in the chronic retention group. It was concluded that patients, with chronic retention experience and higher postoperative residual storage symptoms, after transurethral resection of the prostate, are able to void without a catheter and their renal functions were stabilised. Key Words: Transurethral resection of the prostate, Prostatic hyperplasia, Renal insufficiency, Urinary bladder neck obstruction.

Negatively Charged In-Plane and Out-Of-Plane Domain Walls with Oxygen-Vacancy Agglomerations in a Ca-Doped Bismuth-Ferrite Thin Film.

The interaction of oxygen vacancies and ferroelectric domain walls is of great scientific interest because it leads to different domain-structure behaviors. Here, we use high-resolution scanning transmission electron microscopy to study the ferroelectric domain structure and oxygen-vacancy ordering in a compressively strained Bi0.9Ca0.1FeO3−δ thin film. It was found that atomic plates, in which agglomerated oxygen vacancies are ordered, appear without any periodicity between the plates in out-of-plane and in-plane orientation. The oxygen non-stoichiometry with δ ≈ 1 in FeO2−δ planes is identical in both orientations and shows no preference. Within the plates, the oxygen vacancies form 1D channels in a pseudocubic [010] direction with a high number of vacancies that alternate with oxygen columns with few vacancies. These plates of oxygen vacancies always coincide with charged domain walls in a tail-to-tail configuration. Defects such as ordered oxygen vacancies are thereby known to lead to a pinning effect of the ferroelectric domain walls (causing application-critical aspects, such as fatigue mechanisms and countering of retention failure) and to have a critical influence on the domain-wall conductivity. Thus, intentional oxygen vacancy defect engineering could be useful for the design of multiferroic devices with advanced functionality.

Pediatric dentistry sealants, do they really protect teeth from different mechanical processes?" Literature review

The use of pit and fissure sealants in the area of pediatric dentistry has been very helpful as a preventive measure to avoid carious lesions generally given in the occlusal area of the first permanent molars erupted. These sealants have had constant variations over time, however, the most used are resinous sealants. These types of sealants are mainly classified in polymerization, viscosity and translucency. As dentistry has advanced, they have been divided into two groups (hydrophobic and hydrophilic), both with different characteristics, but with the same purpose, to provide a protective barrier between extrinsic factors and the tooth. However, when in contact with different elements such as humidity, carbohydrates and saliva, as well as having a bad application on the pits and fissures, these tend to fail and begin to present diverse problems such as microfiltration, retention failures and their microhardness. The objective of this literature review was to recognize whether these sealants are adequate to protect the teeth from external factors and whether they can resist various mechanical changes. For this purpose, a literature review was carried out in various databases and dental journals, and articles were selected according to their evidence, established criteria and the year of publication, which was between 2015 and 2020.

Investigation of the adhesion performance of some fast-growing wood species based on their wettability

Abstract The objective of this study was to investigate the adhesion performance of eight fast-growing wood species, namely, Enterolobium cyclocarpum, Paraserianthes falcataria, Shorea sp., Toona sinensis, Gmelina arborea, Pinus merkusii, Acacia mangium, and Acacia hybrid obtained from the tropical region. The wettability test was conducted by contact angle measurement, while the adhesion performance was expressed by strength retention (SR) and wood failure (WF) percentages through block shear tested under the Japanese Agricultural Standard (JAS). Results showed that smaller contact angle for P. falcataria followed by E. cyclocarpum, P. merkusii, T. sinensis, and Shorea indicated that the surfaces were easier to be glued than that of G. arborea, A. mangium, and A. hybrid. It is indicated that high wettability of P. falcataria, E. cyclocarpum, P. merkusii, T. sinensis, and Shorea resulted in the better adhesive spread and more intimate contact between the wood surface and the adhesive as shown by their high SR with high WF percentages.

The quality of etched enamel in different regions and tooth types and its significance in bonding and the development of white spot lesions.

To quantify differences in the etch quality of enamel within and between human teeth, which has not previously been attempted. The buccal right and left halves of 27 extracted human teeth were randomly allocated to scanning electron microscopy (SEM) or micro-computed tomography (μCT) for evaluation. The buccal surfaces were pumiced, etched with 37% phosphoric acid gel etchant for 15 seconds, rinsed, and air dried. Each tooth was divided into three regions (incisal, middle, and cervical) and viewed after etching at 1200× magnification with SEM. The μCT scans were taken before and after etching to calculate apparent and material mineral densities. SEM showed greater aprismatic enamel and poorer etch quality (ie, significantly less percentage enamel) for the posterior than anterior teeth and for the cervical region than for the incisal and middle regions of all teeth. Although there were no density differences prior to etching, μCT demonstrated that etching increased material density significantly more for the anterior than posterior teeth. Prior to etching, the enamel in the cervical regions was significantly less dense than the enamel in the middle or incisal regions. Etching significantly increased the material density of all three regions, which decreased initial regional differences. After etching, the apparent density of the cervical region remained significantly lower than the densities of the other two regions. Based on SEM and μCT, there is greater aprismatic enamel and inferior etch quality in the cervical regions of all tooth types and is clinically significant in explaining the failure of sealant retention and the propensity for white spot lesions.

Accuracy of Predictive Algorithms in Total Hip and Knee Arthroplasty Acute Periprosthetic Joint Infections Treated With Debridement, Antibiotics, and Implant Retention (DAIR)

BackgroundDebridement, antibiotics, and implant retention (DAIR) failure remains high for total hip and knee arthroplasty periprosthetic joint infection (PJI). We sought to determine the predictive value of the CRIME80 and KLIC for failure of DAIR in acute hematogenous (AH) and acute postoperative (AP) PJIs, respectively. MethodsWe identified 134 patients who underwent DAIR for AH PJI with <4 weeks of symptoms after index arthroplasty and 122 patients who underwent DAIR for AP PJI <90 days from index. In the AH group, 15 patients (11%) failed at 90 days and overall, 33 (25%) had failed by 2 years. In the AP group, 39 (32%) failed at 90 days and overall, 52 (43%) failed by 2 years. Logistic regression models were used to determine the area under the curve (AUC) to establish thresholds using the Youden index. ResultsFor the AP cohort, AUCs were below 0.66 for KLIC, Charlson comorbidity index, Elixhauser comorbidity index, and McPherson host grade. For the AH cohort, 90-day AUCs were 0.70 for CRIME80 and below 0.66 for Charlson comorbidity index, Elixhauser comorbidity index, and McPherson host grade. In multivariate analysis controlling for age, sex, and body mass index, the CRIME80 AUC improved to 0.77 at 90 days. ConclusionTo the authors’ knowledge, this study represents the first external validation of the KLIC and CRIME80 for predicting DAIR failure in a North American population. The results indicate that alternative methods for predicting DAIR failure at 90 days and 2 years for acute PJI are needed. Level of EvidencePrognostic III.

Dynamic Behavior Predictions for Fast and Efficient Hybrid STT-MRAM Caches

Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM) is a promising candidate as a universal on-chip memory technology due to its non-volatility, high density, and scalability. However, high write energy and latency are its major shortcomings, particularly for fast cache applications. High write costs can efficiently be reduced by relaxing the STT-MRAM non-volatility requirements at the expense of significant increase in retention failure and read disturb rates resulting in data corruption. Hybrid STT-MRAM architecture combining non-volatile (NVM) and semi-volatile (SVM) STT-MRAM blocks has been proposed recently, which provides energy-efficiency, high storage capacity, better performance, and high reliability. However, a key and challenging requirement is efficient data mapping and migration between NVM and SVM sub-arrays to maximize the benefits of such hybrid caches. On-the-fly data migration decisions usually depend on the last seen data behavior, as it is assumed to be identical to the next one, which has very limited accuracy for rapidly varying workload behavior. In this article, we propose a simple but effective on-the-fly data management policy, which mainly relies on the supervised learning data-pattern classification for quick and highly accurate prediction of the data behavior in the oncoming execution time. Three prediction approaches are proposed and compared for a maximum and average achieved accuracy of 86% and 75%, respectively. Our data management policies aim to optimally leverage the specific features of NVM (high reliability) and SVM blocks (fast and energy-efficient write) of hybrid STT-MRAM memory with minimal migration costs (i.e., energy and performance overheads). Our experimental evaluation reports that for a hybrid STT-MRAM cache with the proposed prediction techniques, the total energy consumption can be reduced around 10.5%, on average, in comparison to the state-of-the-art.

ZEM: Zero-Cycle Bit-Masking Module for Deep Learning Refresh-Less DRAM

In sub-20 nm technologies, DRAM cells suffer from poor retention time. With the technology scaling, this problem tends to be worse, significantly increasing refresh power of DRAM. This is more problematic in memory heavy applications such as deep learning systems, where a large amount of DRAM is required, DRAM refresh power contributes to a considerable portion of total system power. With the growth in deep learning workloads, this is set to get worse. In this work, we present a zero-cycle bit-masking (ZEM) scheme that exploits the asymmetry of retention failures, to eliminate DRAM refresh in the inference of convolution neural networks, natural language processing, and the image generation based on generative adversarial network. Through careful analysis, we derive a bit-error-rate (BER) threshold that does not affect the accuracy of inference. Our proposed architecture, along with the techniques involved, are applicable to all types of DRAMs. Our results on 16Gb devices show that ZEM can improve the performance by up to 17.31% while reducing the total energy consumed by DRAM by up to 43.03%, dependent on the type of DRAM.

Retrospective analysis of the changes in the surgical treatment of benign prostatic hyperplasia during an 11-year period: a single-center experience.

The present study aimed to determine whether the number of patients with symptomatic benign prostatic hyperplasia (BPH) who preferred surgery decreased during the past 11 years at our center (West China Hospital, Chengdu, China), and whether this change affected the timing of surgery and the physical condition of surgical patients. This retrospective study included 57 557 patients with BPH treated from January 2008 to December 2018. Of these, 5427 patients were treated surgically. Surgical patients were divided into two groups based on the time of treatment (groups 8–13 and groups 13–18). The collected data comprised the percentage of all patients with BPH who underwent surgery, baseline characteristics of surgical patients, rehabilitation time, adverse events, and hospitalization costs. The surgery rates in groups 8–13 and groups 13–18 were 10.5% and 8.5% (P < 0.001), respectively. The two groups did not clinically differ regarding patient age and prostate volume. The rates of acute urinary retention and renal failure decreased from 15.0% to 10.6% (P < 0.001) and from 5.2% to 3.1% (P < 0.001), respectively. In groups 8–13 and groups 13–18, the mean catheterization times were 4.0 ± 1.7 days and 3.3 ± 1.6 days (P < 0.001), respectively, and the mean postoperative hospitalization times were 5.1 ± 2.4 days and 4.2 ± 1.8 days (P < 0.001), respectively. The incidences of unplanned second surgery and death reduced during the study period. The surgery rate decreased over time, which suggests that medication was chosen over surgery. However, the percentage of late complications of BPH also decreased over time, which indicates that the timing of surgery was not delayed.

Prevalence of Diabetes Mellitus Among Complete Denture Patients

Diabetes Mellitus is one of the most common metabolic disorders with 1.82 times greater risk in edentulous patients than dentate patients. It is associated with complications like neuropathy, nephropathy, retinopathy, cardiovascular problems and periodontitis. They complain of burning sensation of the mouth and multiple ulcerations in the mouth. All these problems contribute to the failure of retention of complete denture. The aim of the study is to find the prevalence of diabetes mellitus in complete denture patients. Case records of 89,000 patients who visited the hospital between June 2019- April 2020 were retrieved and reviewed. This university setting study involved 351 complete denture patients. Data was tabulated with parameters - name, age, gender, medical history of diabetes or with other systemic diseases. Data was imported to SPSS for statistical analysis. Descriptive statistics and chi-square tests were done. 26.5% of the complete denture patients had diabetes mellitus. Males were found to be slightly more prevalent than females. The most common age group affected was 60-75 years age group. Chi-square test showed no significance between age or gender with diagnosis of diabetes. ( p-value &amp;gt;0.05). Diabetes mellitus is associated directly with edentulism with 26.5% of prevalence with this disease. The most common age group prevalent was in the age group of 60-75 years and commonly seen in males.

Instructional Leadership Practices, Teachers’ Satisfaction and School Performance Indicators

The main thrust of this study was to determine the Instructional Leadership Practices, Teachers’ Satisfaction and the School Performance Indicators and the relationship among these variables. The study was conducted to the thirty secondary schools having full-fledged principals in the Third Congressional District in Bohol. Randomly sampled two hundred eighty five (285) participants comprising 30 principals and the 255 teachers took part in the study. The data were subjected to statistical treatment using the weighted mean to assess the perception of the principals and the teachers about the Instructional Leadership Practices and the teachers’ satisfaction. Pearson Product Moment of Correlation was used to determine the significant relationship between the Instructional Leadership Practices and teachers’ satisfaction. Spearman Rank of Correlation was used to determine the significant relationship between the Instructional Leadership Practices and the school performance indicators. Four of the 10 items of instructional leadership practices were perceived by the principals and teachers as “Always” while 6 of the items were perceived as “Very Often”. Teachers are satisfied in terms of management and very satisfied with their work characteristics and interpersonal relationships. For school performance indicators, most of the respondents obtained a rating of “Outstanding” in terms of retention rate, completion rate, graduation rate, promotion rate, repetition rate, drop-out rate and failure rate. Teachers viewed that the Instructional Leadership Practices is related to teachers’ satisfaction while both the principals and the teachers claimed that it is related to school performance indicators. This study concludes that the principals’ leadership practices can affect teachers’ satisfaction and the school performance indicators. Hence, it is recommended, that DepEd Personnel should utilize the findings of this study and consider the proposed enhancement plan for the improvement of principals instructional leadership practices leading to the improvement of quality of teaching and student learning.

33-Year-Old Woman With Postpartum Acute Shortness of Breath

33-Year-Old Woman With Postpartum Acute Shortness of Breath

Flexoelectricity-induced retention failure in ferroelectric films

Retention failure is deleterious on ferroelectric domain stability, resulting in data loss in ferroelectric memories. However, the understanding of the origin of retention failure remains a challenge for the lack of a direct experimental evidence. Here, using a combination of piezoelectric force microscopy, atomic-scale scanning transmission electron microscopy and reciprocal space mapping, we report that the polarization retention failure is caused by a strain gradient induced flexoelectric field in tetragonal ferroelectric films. Atomic imaging reveals that the strain gradient is introduced by tensile strains, which is resultant from the vertically distributed Pb-rich anti-phase domains. This strain gradient couples with polarizations and results in flexoelectric fields in the films, leading to the retention failure in the films. Our study directly underlines the atomic mechanisms behind the strain gradient induced macroscopic retention failure behavior and clarifies the effect of local strain state on domain relaxation processes, thus can shed light on further understanding and improving the retention properties of oxide ferroelectrics.

Cache-Out: Leaking Cache Memory Using Hardware Trojan

Data leakage is an important security concern in current systems. Existing data leakage prevention techniques assume that the underlying hardware platform is secure and free from tampering. In this work, we present Cache-Out, a class of system attacks involving hardware compromised with a Trojan embedded in the CPU. We assume that a memory Trojan trigger is present in L1 d-cache and gets activated if one particular address of L1 d-cache is hammered with a particular data pattern for a certain number of times. Once the Trojan is triggered, accessing another address delivers payloads, such as, read disturb, write disturb, retention failure, and information leakage. We mainly exploit the advanced circuit features employed in the peripherals of nanometer cache memories, such as wordline underdrive (WLUD) (prevents read disturb) and negative bitline (NBL) (assists write) for static RAM (SRAM) to deliver the payloads. Simulation indicates that WLUD and NBL manipulation can inject read and write failures, respectively. We also show that WLUD activation during write operation can inject write failure. Furthermore, NBL along with column multiplexing can also be leveraged to steal data. We validated Cache-Out using GEM5 architectural simulator. We propose L1 address obfuscation, read/write verification, scrambling error correcting code (ECC) bits, and trusted ECC as countermeasures. Results indicate that read/write verification incurs 7.56 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of area and 0.1 μW/91.3 μW of static/dynamic power in 22-nm technology for a 64-bit word size.

ROCKY: A Robust Hybrid On-chip Memory Kit For The Processors With STT-MRAM Cache Technology

STT-MRAM is regarded as an extremely promising NVM technology for replacing SRAM-based on-chip memories. While STT-MRAM memories benefit from ultra-low leakage power and high density, they suffer from some reliability challenges, namely, read disturbance, write failure, and retention failure. The write failure; storing a wrong value in an STT-MRAM cell during a write operation, is the most crucial reliability challenge. In this article, we propose ROCKY; a robust architecture equipped with efficient replacement policies for STT-MRAM-based cache memory hierarchy to improve the robustness of STT-MRAM part against the write failures. ROCKY reduces susceptible transitions in STT-MRAM cache memories leading to more reliable STT-MRAM write operations. The simulation results through comparison with traditional cache memory hierarchy demonstrate ROCKY decreases the WER of STT-MRAM cache memories by up to 35.4 percent while imposing less than 1 percent performance overhead to the system.

One-year evaluation of a new restorative glass ionomer cement for the restoration of non-carious cervical lesions in patients with systemic diseases: a randomized, clinical trial.

This randomized and clinical trial aimed to evaluate the performance of a new restorative Glass Ionomer Cement (GIC) for the restoration of non-carious cervical lesions (NCCLs) of patients with systemic diseases compared with a posterior resin composite after 12 months. 134 restorations were placed at 30 patients presenting systemic diseases by a single clinician. NCCLs were allocated to two groups according to restorative system used: a conventional restorative GIC [Fuji Bulk (GC, Tokyo Japan) (FB)] and a posterior resin composite [G-ænial Posterior (GC, Tokyo Japan) (GP)] used with a universal adhesive using etch&rinse mode. All restorative procedures were conducted according to manufacturer's instructions. Restorations were scored regarding retention, marginal discoloration, marginal adaptation, secondary caries, surface texture, and post-operative sensitivity using modified United States Public Health Service (USPHS) criteria after 1 week (baseline), 6, and 12 months. Descriptive statistics were performed using chi-square tests. Cochran Q and Mc Nemar's tests were used to detect differences over time. After 12 months, recall rate was 93% and the rates of cumulative retention failure for FB and GP were 4.9% and 1.6% respectively. Both groups presented similar alpha rates for marginal adaptation (FB 86.2%, GP 95.5%) and marginal discoloration (FB 93.8%, GP 97%) at 6-month recall, but FB restorations showed higher bravo scores than GP restorations for marginal adaptation and marginal discoloration after 12 months (p<0.05). Regarding surface texture, 2 FB restorations (3.1%) were scored as bravo after 6 months. All restorations were scored as alpha for secondary caries and postoperative sensitivity after 12 months. Although the posterior resin composite demonstrated clinically higher alpha scores than the conventional GIC for marginal adaptation and discoloration, both materials successfully restored NCCLs at patients with systematic disease after a year. Due to its acceptable clinical results, the tested conventional restorative GIC can be used for the restoration of NCCLs of patients with systemic diseases.