Quantum Key Distribution Mehic, Miralem; Niemiec, Marcin; Rass, Stefan ...
ACM computing surveys,
09/2021, Letnik:
53, Številka:
5
Journal Article
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Odprti dostop
The convergence of quantum cryptography with applications used in everyday life is a topic drawing attention from the industrial and academic worlds. The development of quantum electronics has led to ...the practical achievement of quantum devices that are already available on the market and waiting for their first application on a broader scale. A major aspect of quantum cryptography is the methodology of Quantum Key Distribution (QKD), which is used to generate and distribute symmetric cryptographic keys between two geographically separate users using the principles of quantum physics. In previous years, several successful QKD networks have been created to test the implementation and interoperability of different practical solutions. This article surveys previously applied methods, showing techniques for deploying QKD networks and current challenges of QKD networking. Unlike studies focusing on optical channels and optical equipment, this survey focuses on the network aspect by considering network organization, routing and signaling protocols, simulation techniques, and a software-defined QKD networking approach.
Droughts are complex and may be triggered by different mechanisms, such as atmospheric circulation, moisture transport, and thermodynamic processes. Significant research has been completed to ...characterize precipitation in the Intergovernmental Panel on Climate Change (IPCC) reference regions (RRs), but a systematic analysis of atmospheric transport linked to drought episodes is still missing. This article describes a catalog in which the drought episodes over the RRs are identified during 1980–2015, and the role of the moisture transport anomalies from the respective major climatological moisture sources during the most severe meteorological drought episode registered for each RR is analyzed. For each of the 27 RRs defined in the IPCC Fifth Assessment Report, drought episodes were identified at 1-, 6-, and 12-month time scales through the standardized precipitation evapotranspiration index (SPEI). SPEI values were computed using time series of the monthly precipitation and atmospheric evaporative demand (AED) averaged over each RR. The approach, which was applied to both identify the major climatological moisture sources and sinks for each RR and to investigate anomalies in moisture transport during the episode, is based on the Lagrangian flexible particle dispersion model (FLEXPART), integrated with the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) data. For each RR, the following components were analyzed: a) moisture uptake over sources, b) moisture supply from the sources into the RR, and c) moisture supply from the RR into its sink. Although performed for just one case, this analysis illustrates how the moisture transport may impact the RR during extreme conditions. The results are organized in a web page available to the scientific community and stakeholders.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Anti‐SARS‐CoV‐2 S antibodies prevent viral replication. Critically ill COVID‐19 patients show viral material in plasma, associated with a dysregulated host response. If these antibodies ...influence survival and viral dissemination in ICU‐COVID patients is unknown.
Patients/Methods
We studied the impact of anti‐SARS‐CoV‐2 S antibodies levels on survival, viral RNA‐load in plasma, and N‐antigenaemia in 92 COVID‐19 patients over ICU admission.
Results
Frequency of N‐antigenaemia was >2.5‐fold higher in absence of antibodies. Antibodies correlated inversely with viral RNA‐load in plasma, representing a protective factor against mortality (adjusted HR CI 95%, p): (S IgM AUC ≥ 60: 0.44 0.22; 0.88, 0.020); (S IgG AUC ≥ 237: 0.31 0.16; 0.61, <0.001). Viral RNA‐load in plasma and N‐antigenaemia predicted increased mortality: (N1‐viral load ≥2.156 copies/ml: 2.25 1.16; 4.36, 0.016); (N‐antigenaemia: 2.45 1.27; 4.69, 0.007).
Conclusions
Low anti‐SARS‐CoV‐2 S antibody levels predict mortality in critical COVID‐19. Our findings support that these antibodies contribute to prevent systemic dissemination of SARS‐CoV‐2.
Abstract
Context
Total pancreatectomy with islet autotransplantation (TPIAT) is a definitive management for intractable pain in patients with chronic pancreatitis (CP). Islet autotransplantation ...(IAT) allows for the preservation of beta cells to prevent complications of long-term diabetes.
Objective
Our study follows TPIAT recipients for up to 12 years to determine the efficacy of the procedure completed with an off-site islet isolation facility.
Methods
Patient demographics, mixed meal tolerance test measures, glycosylated hemoglobin, insulin requirements, and homeostatic model assessment for insulin resistance values were collected prior to surgery and at the most recent follow-up assessment.
Results
Forty-four patients (median age, 46.0 years; range, 20-78 years) underwent TPIAT for CP. At an overall median follow-up time of 845.5 days (range, 195-4470 days) 8 patients were insulin independent and 36 patients were insulin dependent. At the most recent follow-up time point, islet yield per kilogram was the strongest indicator of insulin independence. Homeostatic model assessment for insulin resistance values were comparable between insulin independent and dependent cohorts.
Conclusions
Our long-term follow-up data suggest that IAT can effectively reduce insulin requirements and improve postoperative glycemic control.
Introduction
Pregnant women are vulnerable to severe acute respiratory syndrome coronavirus (SARS‐CoV‐2) infection. Neutralizing antibodies against the SARS‐CoV‐2 spike (S) protein protect from ...severe disease. This study analyzes the antibody titers to SARS‐CoV‐2 S protein in pregnant women and their newborns at delivery, and six months later.
Methods
We conducted a prospective study on pregnant women with confirmed SARS‐CoV‐2 infection and newborns. Antibody (IgG, IgM, and IgA) titers were determined using immunoassays in serum and milk samples. An angiotensin‐converting enzyme 2 (ACE2) receptor‐binding inhibition assay to the S protein was performed on the same serum and milk samples.
Results
At birth, antibodies to SARS‐CoV‐2 spike protein were detected in 81.9% of mothers' sera, 78.9% of cord blood samples, and 63.2% of milk samples. Symptomatic women had higher antibody titers (IgG, IgM, and IgA) than the asymptomatic ones (P < 0.05). At six months postpartum, IgG levels decreased drastically in children's serum (P < 0.001) but remained high in mothers' serum. Antibody titers correlated positively with its capacity to inhibit the ACE2–spike protein interaction at baseline in maternal sera (R2 = 0.203; P < 0.001), cord sera (R2 = 0.378; P < 0.001), and milk (R2 = 0.564; P < 0.001), and at six months in maternal sera (R2 = 0.600; P < 0.001).
Conclusions
High antibody levels against SARS‐CoV‐2 spike protein were found in most pregnant women. Due to the efficient transfer of IgG to cord blood and high IgA titers in breast milk, neonates may be passively immunized to SARS‐CoV‐2 infection. Our findings could guide newborn management and maternal vaccination policies.
Epidemiologic and animal data indicate that night shift work might increase the risk for breast cancer. We evaluated the association of night work with different clinical types of breast cancer in a ...population based case-control study (MCC-Spain study) taking into account chronotype, an individual characteristic that may relate to night shift work adaptation. Lifetime occupational history was assessed by face-to-face interviews and shift work information was available for 1708 breast cancer cases and 1778 population controls from 10 Spanish regions, enrolled from 2008 to 2013. We evaluated three shift work domains, including shift work type (permanent vs rotating), lifetime cumulative duration and frequency. We estimated odds ratios (OR) for night work compared to day work using unconditional logistic regression models adjusting for confounders. Having ever worked permanent or rotating night shift was associated with an increased risk for breast cancer compared to day workers odds ratio (OR) 1.18; 95 % CI 0.97,1.43. Chronotype was differentially associated with breast cancer depending on the duration of night shift work. Risk was higher in women with invasive tumors (OR 1.23; 95 % CI 1.00, 1.51) and for estrogen and progestagen positive tumors among premenopausal women (OR 1.44; 95 % CI 1.05, 1.99). Having ever performed night shift was associated with a small increased risk for breast cancer and especially in subgroups of women with particular hormone related characteristics.
Increasing age is associated with severity and higher mortality of COVID‐19. Telomere shortening is associated with higher risk of infections and may be used to identify those patients who are more ...likely to die. We evaluated the association between relative telomere length (RTL) and COVID‐19 mortality. RTL was measured in patients hospitalized because of COVID‐19. We used Kaplan–Meier method to analyze survival probabilities, and Cox regression to investigate the association between RTL and mortality (30 and 90 days). Six hundred and eight patients were included in the analysis (mean age =72.5 years, 41.1% women, and 53.8% Caucasic). During the study period, 75 people died from COVID‐19 and 533 survived. Lower RTL was associated with a higher risk of death in women either at 30 (adjusted hazard ratio HR (aHR) = 3.33; 95% confidence interval CI = 1.05–10.00; p = 0.040) and at 90 days (aHR = 3.57; 95%CI = 1.23–11.11; p = 0.019). Lower RTL was associated with a higher risk of dying of COVID‐19 in women. This finding suggests that RTL has an essential role in the prognosis of this subset of the population.
Abstract
Context
Molecular tests have improved the accuracy of preoperative diagnosis of indeterminate thyroid nodules. The Afirma Gene Sequencing Classifier (GSC) was developed to improve the ...specificity of the Gene Expression Classifier (GEC). Independent studies are needed to assess the performance of GSC.
Objective
The aim was to compare the performance of GEC and GSC in the assessment of indeterminate nodules.
Design, Settings, and Participants
Retrospective analysis of Bethesda III and IV nodules tested with GEC or GSC in an academic center between December 2011 and September 2018. Benign call rates (BCRs) and surgical outcomes were compared. Histopathologic data were collected on nodules that were surgically resected to calculate measures of test performance.
Results
The BCR was 41% (73/178) for GEC and 67.8% (82/121) for GSC (P < .001). Among specimens with dominant Hürthle cell cytology, the BCR was 22% (6/27) for GEC and 63.2% (12/19) for GSC (P = .005). The overall surgery rate decreased from 47.8% in the GEC group to 34.7% in the GSC group (P = .025). One GEC-benign and 3 GSC-benign nodules proved to be malignant on surgical excision. GSC had a statistically significant higher specificity (94% vs 60%, P < .001) and positive predictive value (PPV) (85.3% vs 40%, P < .001) than GEC. While sensitivity and negative predictive value (NPV) dropped with GSC (97.0% vs 90.6% and 98.6% vs 96.3%, respectively), these differences were not significant.
Conclusions
GSC reclassified more indeterminate nodules as benign and improved the specificity and PPV of the test. These enhancements appear to be resulting in fewer diagnostic surgeries.
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