Addressing Prolonged Restore Challenges in Further Scaling DRAMs

As the de facto memory technology, DRAM has enjoyed continuous scaling over the past decades to keep performance growth and capacity enhancement. However, DRAM further scaling into deep sub-micron regime faces significant challenges. Among the induced issues, prolonged restore time is expected to be one of the major concerns, but it has been paid little attention. Aiming at restore issue, this thesis performs pioneering studies to characterize the problems, and presents techniques from different perspectives to overcome them. First, our experimental studies quantify the significant restore process variations, causing serious degradations on yield and/or performance. To solve the problem, we propose schemes to expose the variations to the architectural levels. Fast restore chunks can thus be constructed utilizing DRAM organization, and they can be exposed to the memory controller to effectively compensate the performance loss. Further, we maximize the improvement by applying restore-time-aware rank construction and hotness-aware page allocation schemes to fully utilize the fast regions. Second, in addition to simply expose the variations to higher levels, we investigate DRAM cell structures and behaviors finding that refresh and restore are two strongly correlated operations. Whereas are being fully restored after each read or write access, DRAM cells are always being fully charged by periodical refresh operations, providing an opportunity to early terminate restore. With the insight, we first propose to truncate a restore using the time distance to next refresh. Further, to provide more truncation opportunities, we integrate the multirate-refresh concepts to shorten the distance by increasing the refresh rate of recently accessed regions. Lastly, we explore higher to the application level with the inspiration that a large set of applications can well tolerate output accuracy loss and runtime errors, enabling us to exploit approximate computing to mitigate prolonged restore. By utilizing the variance in restore timing exhibited at different row segments, we reduce the restore time such that only partial segments are fully reliable. We then map the critical data onto the reliable segments to keep the application-level errors low. Atop of the approximation-aware technique, we further generalize it to support precise computing as well

A case of the application of Paxlovid for a patient infected by the SARS-CoV-2 Omicron variant

Coronavirus disease 2019 (COVID-19) is a new acute respiratory infectious disease with high infectivity. To date, > 500 million cases of COVID-19 have been confirmed worldwide (World Health Organization). The Omicron variant has affected nearly every country worldwide due to its high infectivity and immune evasion, which has caused widespread anxiety. However, most of the existing treatments do not effectively reduce the risk of progression to more severe disease, or the existing treatments are too costly or not suitable for extensive use.Paxlovid is a novel oral antiviral drug that has proven effective against symptomatic COVID-19 infection by reducing the risk of progression to severe disease, hospitalization, and mortality

Analysis of the imaging and clinical features of subsolid pulmonary nodules in stage IA non-small cell lung cancer

The subsolid pulmonary nodules (SSPNs) in the imaging diagnosis of stage IA non-small cell lung cancer (NSCLC) is very important since they are closely related to early lung cancer. The CT imaging and pathology data of 230 patients with solitary pulmonary nodules (SPNs) who underwent thoracoscopic treatment at Guizhou Provincial People’s Hospital between July 2021 and June 2022 were collected. Based on postoperative pathology, the patients were divided into a benign group and a stage IA NSCLC group. The imaging and clinical features of SPNs in stage IA NSCLC were analysed. A total of 230 patients with SPNs were enrolled. There were 146 cases of SSPNs (including 34 cases of pure ground-glass opacities (pGGOs) and 112 cases of mixed GGOs (mGGOs)), and the incidence rate was significantly higher in the stage IA NSCLC group than in the benign group [96.7% (146/151) vs. 74.7% (59/79), P<0.05]. The overall malignancy rate of subsolid nodules was 71.2% (146/205); the malignancy rate of mGGO lesions was higher (75.2%) than that of pGGO lesions (60.7%) and solid nodules (20%). Malignant subsolid nodules mostly occurred in middle-aged women, mostly in the upper lobe of the lungs, with unclear edges and lobular signs, and accompanied by spur signs and pleural indentation signs (P<0.05). SSPNs are an important sign of lung cancer, and mGGO lesions have the highest malignant tendency. CT imaging findings such as unclear lesion edges, lobular signs, and pleural indentation signs are important for determining benign and malignant SSPNs. CT imaging manifestations are helpful for correctly assessing the nature of early SSPNs so that patients can receive timely and effective treatment

Environmental Factors Influencing the Durability of Concrete Structures in Maine Environments

Concrete structures built in marine environment may suffer serious durability problems. Focusing on the reaction between concrete materials and environmental conditions on structural durability, the coefficients of environmental temperature and chloride content are established. Referring to only experimental data tested following the procedure similar to the regulations in NT Build 443(Concrete, Hardened: Accelerated Chloride Penetration) of North Europe, the relationship between D28 and water/binder ratio, which are converted into equivalent values of a standard reference environmental condition at 20ºC and a concentration of 165 g ± 1 g NaCl per dm3 solution, using the established formula of coefficients of environmental temperature and chloride content, is presented. The converted results of different environmental conditions at laboratory and natural environment have a good agreement with each other, which indicates that the coefficients of environmental temperature and chloride content are reasonably determined. The ratio of wetting time per-period defined as the time proportion of concrete in wet conditions to the whole time period can be used to describe the dry-wet conditions in concrete. Analysis on the in-situ detected results shows that the penetration of chloride, the accumulation of surface chloride concentration and the decay of chloride diffusion coefficient are all related to the ratio of wetting time per-period. Subsequently, the formula of apparent chloride diffusion coefficient is proposed with consideration of surrounding temperature, sodium chloride solution concentration, age factor and altitude

Laparoscopic surgery for intestinal obstruction in children due to water absorbing gel beads

Introductions: Super absorbent polymer gel bead (SAPGB) is increasingly available as toys for children. When ingested it swells by absorbs water and leads to acute intestinal obstruction. Diagnosis and surgery is challenging as its radiolucent, fragile and slippery. We present outcome of our innovative technique of stabilization and removal SAPGBs by laparoscopy minimal invasive surgery (lap-MIS). Methods: This retrospective analyse of outcome of lap-MIS in intestinal obstruction caused by ingestion of foreign body, the SAPGBs, in children who were managed at Children's Hospital Affiliated to Zhengzhou University, China. The outcome variables included removal of SAPGBs, length of hospital stay and postoperative occurrence of anastomotic leak, wound infection, wound dehiscence, re-surgery, or mortality. Results: There were 15 children, male 9 (60%), average age 2 years, and duration of ingestion of SAPGBSs 1.5 days (range 2-4 days), parents gave history of accidental ingestion in 6 (40%). All children had uneventful postoperative recovery after lap-MIS removal of foreign body with no wound infection, anastomotic leak, re-surgery or mortality. Average hospital stay was 4 days (range 3 to 5 days). Conclusions: We had successful outcome lap-MIS with our innovative technique to stabilize and extract foreign bodies, the super water absorbent gel beads, ingested by children. Keywords: children, foreign body, gastrointestinal obstruction, laparoscopy minimal invasive surgery, super absorbent polymer gel bead