SecNVM: An Efficient and Write-Friendly Metadata Crash Consistency Scheme for Secure NVM

Data security is an indispensable part of non-volatile memory (NVM) systems. However, implementing data security efficiently on NVM is challenging, since we have to guarantee the consistency of user data and the related security metadata. Existing consistency schemes ignore the recoverability of the SGX style integrity tree (SIT) and the access correlation between metadata blocks, thereby generating unnecessary NVM write traffic. In this article, we propose SecNVM, an efficient and write-friendly metadata crash consistency scheme for secure NVM. SecNVM utilizes the observation that for a lazily updated SIT, the lost tree nodes after a crash can be recovered by the corresponding child nodes in NVM. It reduces the SIT persistency overhead through a restrained write-back metadata cache and exploits the SIT inter-layer dependency for recovery. Next, leveraging the strong access correlation between the counter and DMAC, SecNVM improves the efficiency of security metadata access through a novel collaborative counter-DMAC scheme. In addition, it adopts a lightweight address tracker to reduce the cost of address tracking for fast recovery. Experiments show that compared to the state-of-the-art schemes, SecNVM improves the performance and decreases write traffic a lot, and achieves an acceptable recovery time.

Comparison of the effects of remifentanil and dexmedetomidine on surgeon satisfaction with surgical field visualization and intraoperative bleeding during rhinoplasty

Objective We aimed to compare the effect of dexmedetomidine with remifentanil on hemodynamic stability, surgical field quality, and surgeon satisfaction during rhinoplasty. Methods and materials In this double-blind randomized controlled-trial, 60 participants scheduled for rhinoplasty at the Mother and Child Hospital, Shiraz, Iran, was randomely divided into the dexmedetomidine group (IV infusion of 1 μg/kg dexmedetomidine over 20 min before induction of anesthesia then 0.6 μg/kg/hr. dexmedetomidine from the time of induction until the end of the operation) or in the the remifentanil group (an infusion rate of 0.25 μg/kg/min from the time of anesthesia induction until the end of the operation). Bleeding volume, surgeon satisfaction, postoperative pain (visual analog scale (VAS)), Level of sedation (Richmond Agitation Sedation Scale (RASS)), Patient satisfaction, Vital signs & recovery, and the Aldrete Score (used to discharge the patients from recovery) were measured for all participants. Results The patients in the dexmedetomidine group had less bleeding (p = 0.047) and shorter time to return of respiration, extubation, and the postoperative recovery time (p < 0.001). The surgeon satisfaction was higher in the dexmedetomidine group (p < 0.001). Patient satisfaction was significantly different between the two groups (p < 0.001). VAS scores, intaking paracetamol, and RASS score were significantly lower in the remifentanil group (p < 0.001). SBP, DBP, MAP, and heart rate were lower in dexmedetomidine group. Conclusion Dexmedetomidine was associated with relatively stable hemodynamics, leading to decreased intraoperative bleeding, recovery time, and greater surgeon satisfaction and the level of consciousness in the recovery ward. However, painlessness and patient satisfaction were greater with the use of remifentanil. Trial registration IRCT20141009019470N112.

Ajmaline‐Induced Abnormalities in Brugada Syndrome: Evaluation With ECG Imaging

Background The rate of sudden cardiac death (SCD) in Brugada syndrome (BrS) is ≈1%/y. Noninvasive electrocardiographic imaging is a noninvasive mapping system that has a role in assessing BrS depolarization and repolarization abnormalities. This study aimed to analyze electrocardiographic imaging parameters during ajmaline test (AJT). Methods and Results All consecutive epicardial maps of the right ventricle outflow tract (RVOT‐EPI) in BrS with CardioInsight were retrospectively analyzed. (1) RVOT‐EPI activation time (RVOT‐AT); (2) RVOT‐EPI recovery time, and (3) RVOT‐EPI activation‐recovery interval (RVOT‐ARI) were calculated. ∆RVOT‐AT, ∆RVOT‐EPI recovery time, and ∆RVOT‐ARI were defined as the difference in parameters before and after AJT. SCD‐BrS patients were defined as individuals presenting a history of aborted SCD. Thirty‐nine patients with BrS were retrospectively analyzed and 12 patients (30.8%) were SCD‐BrS. After AJT, an increase in both RVOT‐AT [105.9 milliseconds versus 65.8 milliseconds, P <0.001] and RVOT‐EPI recovery time [403.4 milliseconds versus 365.7 milliseconds, P <0.001] was observed. No changes occurred in RVOT‐ARI [297.5 milliseconds versus 299.9 milliseconds, P =0.7]. Before AJT no differences were observed between SCD‐BrS and non SCD‐BrS in RVOT‐AT, RVOT‐EPI recovery time, and RVOT‐ARI ( P =0.9, P =0.91, P =0.86, respectively). Following AJT, SCD‐BrS patients showed higher RVOT‐AT, higher ∆RVOT‐AT, lower RVOT‐ARI, and lower ∆RVOT‐ARI ( P <0.001, P <0.001, P =0.007, P =0.002, respectively). At the univariate logistic regression, predictors of SCD‐BrS were the following: RVOT‐AT after AJT (specificity: 0.74, sensitivity 1.00, area under the curve 0.92); ∆RVOT‐AT (specificity: 0.74, sensitivity 0.92, area under the curve 0.86); RVOT‐ARI after AJT (specificity 0.96, sensitivity 0.58, area under the curve 0.79), and ∆RVOT‐ARI (specificity 0.85, sensitivity 0.67, area under the curve 0.76). Conclusions Noninvasive electrocardiographic imaging can be useful in evaluating the results of AJT in BrS.

Metformin Alters the Chemotaxis and Flagellar Motility of Escherichia coli

Metformin is a biguanide molecule that is widely prescribed to treat type 2 diabetes and metabolic syndrome. Although it is known that metformin promotes the lifespan by altering intestinal microorganism metabolism, how metformin influences and alters the physiological behavior of microorganisms remains unclear. Here we studied the effect of metformin on the behavior alterations of the model organism Escherichia coli (E. coli), including changes in chemotaxis and flagellar motility that plays an important role in bacterial life. It was found that metformin was sensed as a repellent to E. coli by tsr chemoreceptors. Moreover, we investigated the chemotactic response of E. coli cultured with metformin to two typical attractants, glucose and α-methyl-DL-aspartate (MeAsp), finding that metformin prolonged the chemotactic recovery time to the attractants, followed by the recovery time increasing with the concentration of stimulus. Metformin also inhibited the flagellar motility of E. coli including the flagellar motor rotation and cell swimming. The inhibition was due to the reduction of torque generated by the flagellar motor. Our discovery that metformin alters the behavior of chemotaxis and flagellar motility of E. coli could provide potential implications for the effect of metformin on other microorganisms.

Differences in Outcome and Comparison of Stress and Immune Status in Patients with Recurrent Common Bile Duct Stones after Biliary Tract Surgery Choosing Three Procedures (ERCP, OCBDE, and LCBDE) for Treatment

Objective. To compare the effect of choosing ERCP, OCBDE, and LCBDE for the treatment of patients with recurrent common bile duct stones after biliary tract surgery. Method. 115 patients with recurrent common bile duct stones after biliary surgery in our hospital were retrospectively analyzed and divided into three groups according to the procedure, 36 patients in the ERCP group, 38 patients in the OCBDE group, and 41 patients in the LCBDE group, and compared the efficacy, stress status, and immune status of the three groups. Result. The stone removal rates were 91.67%, 97.37%, and 97.56% in the ERCP, OCBDE, and LCBDE groups, respectively ( P > 0.05 ). There were statistical differences between the ERCP, OCBDE, and LCBDE groups in terms of operative time, postoperative recovery time of exhaustion, recovery time of defecation, recovery time of feeding, and hospitalization time ( P < 0.05 ). The postoperative complication rates were 8.33%, 10.53%, and 7.32% in the ERCP, OCBDE, and LCBDE groups, respectively ( P > 0.05 ). The recurrence rates within 1 year after surgery were 2.78%, 7.89%, and 2.44% in the ERCP, OCBDE, and LCBDE groups, respectively ( P > 0.05 ). Conclusion. ERCP has short operative time, short hospital stay, and rapid postoperative recovery. LCBDE has mild trauma, and OCBDE has a wide range of application. Each of the three procedures has its own advantages and shortcomings, and the most appropriate procedure should be selected on the basis of comprehensive evaluation.

What Is the Evidence on Natural Recovery Over the Year Following Sports-Related and Non-sports-Related Mild Traumatic Brain Injury: A Scoping Review

Background: Treatment approaches often differ dependent upon whether a person experiences a sports-related or a non-sports-related mild traumatic brain injury. It remains unclear if recovery from these injuries is comparable or unique to context of the injury.Objective: To identify knowledge gaps on self-reported outcomes and trajectories between sports- and non-sports-related mild traumatic brain injuries and how they are assessed in adults.Methods: This scoping review used a systematic search of key electronic databases, including PubMed, SPORTDiscus, Embase, MEDLINE, and CINAHL for articles published in 1937 until March 10, 2021. Articles were included if they were available in English; full text published in a peer-reviewed journal; had a prospective or retrospective study design; reported data on mild TBI cases &gt;16 years of age, and included data from at least two time points on self-reported outcomes within 12 months post-injury. A standardized data extraction spreadsheet was used to determine the participant characteristics, definitions, assessment methods, outcomes, and recovery time frames.Results: Following removal of duplicates, the search strategy elicited 6,974 abstracts. Following abstract review, 174 were retained for full text review. Of the 42 articles that met inclusion criteria, 18 were sports related (15 in the USA and three in Canada) and 24 were general population studies (six in USA, three in Canada, three in Australasia, nine in Europe, two in Taiwan, and one in Morocco). Direct comparison in recovery trajectories between the sport and general population studies was difficult, given notable differences in methodology, definitions, types of outcome measures, and timing of follow-up assessments. Only one article reported on both sports-related and non-sports-related traumatic brain injuries separately at comparable timepoints. This study revealed no differences in recovery time frames or overall symptom burden.Discussion: Whilst there is a clear benefit in researching specific subpopulations in detail, standardized outcome measures and follow-up time frames are needed across contexts to facilitate understanding of similarities and differences between sports- and non-sports-related mild traumatic brain injuries to inform clinical treatment.