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In cryptography, a ring signature is anonymous as it hides the signer’s identity among other users. When generating the signature, the users are arranged as a ring. Compared with group signatures, a ring signature scheme needs no group manager or special setup and supports flexibility of group choice. However, the anonymity provided by ring signatures can be used to conceal a malicious signer and put other ring members under suspicion. At the other extreme, it does not allow the actual signer to prove their identity and gain recognition for their actions. A deniable ring signature is designed to overcome these disadvantages. It can initially protect the signer, but if necessary, it enables other ring members to deny their involvement, and allows the real signer to prove who made the signed action. Many real-world applications can benefit from such signatures. Inspired by the requirement for them to remain viable in the post-quantum age, this work proposes a new non-interactive deniable ring signature scheme based on lattice assumptions. Our scheme is proved to be anonymous, traceable and non-frameable under quantum attacks.

We sought to examine the impact of race on the management and outcomes of appendicitis in children aged 20 years or younger. We studied 96,865 inpatient admissions for children undergoing an appendectomy for acute appendicitis in 2009 using the Kids' Inpatient Database. Perforation at presentation was more common among African-Americans and Hispanics than Caucasians (27.5% and 32.5%, respectively, vs 23.9%, P < .001). African-Americans were less likely to have a laparoscopic procedure (odds ratio [OR]: .839, P < .001) and more likely to experience a complication (OR: 1.753, P < .001). Hispanics were also more likely to have a complication (OR: 1.123, P = .001). African-Americans and Hispanics remained in the hospital for .73 more days than Caucasians (3.07 vs 2.34 days, P < .001). African-American and Hispanic children present more often with perforation. Adjusting for perforation, they were more likely to have a complication and longer hospital stays. Access to care and delayed presentations may be potential explanations.

To report a case that substantiates the presence of hypoglycemia at the time of death of a young man with type 1 diabetes, who was found unresponsive in his undisturbed bed in the morning. We describe a 23-year-old man with a history of type 1 diabetes treated with an insulin pump, who had recurrent severe hypoglycemia. In an effort to understand these episodes better and attempt to eliminate them, a retrospective (non-real-time) continuous subcutaneous glucose monitoring system (CGMS) was attached to the patient. He was found dead in his undisturbed bed 20 hours later. The insulin pump and CGMS were both downloaded for postmortem study. Postmortem download of the data in the CGMS demonstrated glucose levels below 30 mg/dL around the time of his death, with only a minimal counter-regulatory response. This finding corresponded to a postmortem vitreous humor glucose of 25 mg/dL. An autopsy showed no major anatomic abnormalities that could have contributed to his death. To our knowledge, this is the first documentation of hypoglycemia at the time of death in a patient with the \"dead-in-bed\" syndrome. This report should raise the awareness of physicians to the potentially lethal effects of hypoglycemia and provide justification for efforts directed at avoiding nocturnal hypoglycemia.

The pseudopterosins are a family of diterpene marine natural products, which, by virtue of their interesting anti-inflammatory and analgesic properties, have attracted the attentions of many synthetic chemists. The most efficient syntheses reported to date are 14 and 20 steps in the longest linear sequence for chiral pool and enantioselective approaches, respectively, and all start with precursors that are easily mapped onto the natural product structure. Here, we describe an unconventional approach in which a chiral cross-conjugated hydrocarbon is used as the starting material for a series of three cycloadditions. Our approach has led to a significant reduction in the step count required to access these interesting natural products (10 steps chiral pool and 11 steps enantioselective). Furthermore it demonstrates that cross-conjugated hydrocarbons, erroneously considered by many to be too unstable and difficult to handle, are viable precursors for natural product synthesis. The pseudopterosins are a family of natural products whose interesting anti-inflammatory and pain-relieving properties have inspired many synthetic approaches. Now, an unusual approach that starts with an axially chiral hydrocarbon that engages in a triple Diels–Alder sequence has been shown to result in the shortest total synthesis of a pseudopterosin so far.

End-stage renal disease occurs when there is permanent loss of the kidney’s ability to filter toxins from the blood. Due to the limited number of transplants, dialysis is currently the most common treatment, but it significantly limits a patient’s lifestyle and has significant side effects. One solution is an artificial kidney, but significant challenges remain in its development. One challenge is the separation of glucose from urea. Nanofiltration is ideal for this separation; however, there is little understanding of the important parameters for this separation under physiological conditions. In this study, operating parameters (pressure and temperature) as well as feed conditions (increased glucose/salt) were explored for their effects on the separation of glucose from urea in six commercial membranes. The rejection of monovalent and divalent ions was also characterized. While increasing pressure increased flux, it had little effect on metabolite rejection, except for glucose, which increased above 20 psi. Increasing temperature led to a slight increase in flux and a slight decrease in the rejection of divalent ions. Glucose rejection was sensitive to feed conditions, while urea rejection was less affected. Divalent ions were rejected more strongly than monovalent ions and were also more affected by feed conditions.

Objective This study aimed to investigate the sociodemographic, clinical and renal correlates associated with severe anaemia among people with HIV. Methods We conducted a cross-sectional analysis of people with HIV on antiretroviral therapy (ART) for at least 6 months, stratified by anaemia status. Anaemia was defined based on the World Health Organisation (WHO) classification, as haemoglobin concentration lower than normal i.e. <12 g/dl in females and < 13 g/dl in males and the primary outcome, severe anaemia, as a haemoglobin level below 8 g/dl according to the World Health Organisation. Results The study comprised 372 participants receiving ART, of whom 236 (63.4%) were females. The mean age ± SD of the participants was 44.8 ± 12.4 years. The overall prevalence of severe anaemia was 7.8% (95% CI: 0.053–0.111). In multivariable logistic regression analysis, factors significantly associated with severe anaemia were female sex (Adjusted Odds Ratio (AOR: 14.3, 95% CI: 2.14–126.6), albumin (AOR: 0.93 95% CI: 0.88–0.98) and creatinine levels (AOR: 1.01 95% CI: 1.00-1.03).

Hyperglycemia is associated with increased mortality in critically ill patients treated with total parenteral nutrition (TPN). The role of glucose variability (GV) in predicting outcomes in these patients is not known. This retrospective study included medical and surgical patients receiving TPN in a community teaching hospital. GV was calculated by standard deviation (SD) of blood glucose (BG) values and by mean BG daily (Δ) change (daily max - daily minimum). A total of 276 medical and surgical patients (mean age: 51 ± 18 years), 19% with a history of diabetes mellitus (DM), and 74% with intensive care unit (ICU) admission were treated with TPN. During TPN, the mean daily BG was 142.9 ± 33 mg/dL; frequencies of hypoglycemia < 70 and < 40 mg/dL were 41% and 3%, respectively; and hospital mortality was 27.2%. The mean GV by SD was 38 ± 21 mg/dL and by mean (D) change 58 ± 34 mg/dL. GV was significantly higher in deceased patients (SD: 48 ± 25 vs. 34 ± 18 mg/dL and Δ change: 75 ± 39 vs. 51 ± 29 mg/dL, both P < .01) than surviving patients. Multivariate analysis adjusted for age, DM status, gender, APACHE (Acute Physiology and Chronic Health Evaluation) score, mean daily glucose, and hypoglycemia revealed that GV was an independent predictor of hospital mortality (P < .05). The association between GV and mortality was limited to patients without a history of DM and was not present in patients with DM. High GV is associated with increased hospital mortality independent of the presence and severity of hyperglycemia or hypoglycemia during TPN therapy. Prospective randomized trials are needed to determine if reduction in GV with intensive glycemic control improves clinical outcomes in patients treated with TPN.

Extracorporeal membrane oxygenation (ECMO) is an increasingly used supportive measure for patients with refractory cardiogenic shock (CS). Despite its increasing use, there remain minimal data regarding which patients with refractory CS are most likely to benefit from ECMO. We retrospectively studied all patients (n = 123) who underwent initiation of ECMO for CS from February 2009 to September 2014 at a single center. Baseline patient characteristics, including demographics, co-morbid illness, cause of CS, available laboratory values, and patient outcomes were analyzed. Overall, 69 patients (56%) were weaned from ECMO, with 48 patients (39%) surviving to discharge. Survivors were younger (50 vs 60 years; p ≤0.0001), had a lower rate of previous smoking (27 vs 56%; p = 0.01) and chronic kidney disease (2% vs 13%; p = 0.03), and had lower lactate measured soon after ECMO initiation (3.1 vs 10.2 mmol/l; p = 0.01). Patients with pulmonary embolism (odds ratio 8.0, 95% confidence interval 2.00 to 31.99; p = 0.01) and acute cardiomyopathy (odds ratio 7.5, 95% confidence interval 1.69 to 33.27; p = 0.01) had a higher rate of survival than acute myocardial infarction, chronic cardiomyopathy, and miscellaneous etiologies compared to postcardiotomy CS as a referent. In conclusion, survival after ECMO initiation differs based on underlying cause of CS. Survival may be lower in older patients and those with early evidence of persistent hypoperfusion after initiation of ECMO for CS.

Aortic valve stenosis (AS) is the most common valvular heart disease, and valve replacement is the only definitive treatment. Here we report a large genome-wide association (GWA) study of 2,457 Icelandic AS cases and 349,342 controls with a follow-up in up to 4,850 cases and 451,731 controls of European ancestry. We identify two new AS loci, on chromosome 1p21 near PALMD (rs7543130; odds ratio (OR) = 1.20, P  = 1.2 × 10 −22 ) and on chromosome 2q22 in TEX41 (rs1830321; OR = 1.15, P  = 1.8 × 10 −13 ). Rs7543130 also associates with bicuspid aortic valve (BAV) (OR = 1.28, P  = 6.6 × 10 −10 ) and aortic root diameter ( P  = 1.30 × 10 −8 ), and rs1830321 associates with BAV (OR = 1.12, P  = 5.3 × 10 −3 ) and coronary artery disease (OR = 1.05, P  = 9.3 × 10 −5 ). The results implicate both cardiac developmental abnormalities and atherosclerosis-like processes in the pathogenesis of AS. We show that several pathways are shared by CAD and AS. Causal analysis suggests that the shared risk factors of Lp(a) and non-high-density lipoprotein cholesterol contribute substantially to the frequent co-occurence of these diseases. Aortic valve stenosis (AS) is the most common valvular heart disease. Here the authors identify two new AS loci that also associate with bicuspid aortic valve, aortic root diameter and/or coronary artery disease implicating both developmental abnormalities and atherosclerosis-like processes in AS.

Initiation of the antiarrhythmic medication dofetilide requires an FDA-mandated 3 days of telemetry monitoring due to heightened risk of toxicity within this time period. Although a recommended dose management algorithm for dofetilide exists, there is a range of real-world approaches to dosing the medication. In this multicenter investigation, clinical data from the Antiarrhythmic Drug Genetic (AADGEN) study was examined for 354 patients undergoing dofetilide initiation. Univariate logistic regression identified a starting dofetilide dose of 500 mcg (OR 5.0, 95%CI 2.5-10.0, p<0.001) and sinus rhythm at the start of dofetilide loading (OR 2.8, 95%CI 1.8-4.2, p<0.001) as strong positive predictors of successful loading. Any dose-adjustment during loading (OR 0.19, 95%CI 0.12-0.31, p<0.001) and a history coronary artery disease (OR 0.33, 95%CI 0.19-0.59, p<0.001) were strong negative predictors of successful dofetilide loading. Based on the observation that any dose adjustment was a significant negative predictor of successful initiation, we applied multiple supervised approaches to attempt to predict the dose adjustment decision, but none of these approaches identified dose adjustments better than a probabilistic guess. Principal component analysis and cluster analysis identified 8 clusters as a reasonable data reduction method. These 8 clusters were then used to define patient states in a tabular reinforcement learning model trained on 80% of dosing decisions. Testing of this model on the remaining 20% of dosing decisions revealed good accuracy of the reinforcement learning model, with only 16/410 (3.9%) instances of disagreement. Dose adjustments are a strong determinant of whether patients are able to successfully initiate dofetilide. A reinforcement learning algorithm informed by unsupervised learning was able to predict dosing decisions with 96.1% accuracy. Future studies will apply this algorithm prospectively as a data-driven decision aid.