Steric modulation of ionic currents in DNA translocation through nanopores

Ionic currents accompanying DNA translocation strongly depend on molarity of the electrolyte solution and the shape and surface charge of the nanopore. By means of the Poisson-Nernst-Planck equations it is shown how conductance is modulated by the presence of the DNA intruder and as a result of competing electrostatic and confinement factors. The theoretical results reproduce quantitatively the experimental ones and are summarized in a conductance diagram that allows distinguishing the region of reduced conductivity from the region of enhanced conductivity as a function of molarity and the pore dimension.Comment: 22 pages, 7 figure

Photonics based perfect secrecy cryptography : toward fully classical implementations

Funding: A.D.F. acknowledges support from UK EPSRC (EP/L017008/1).Developing an unbreakable cryptography is a longstanding question and a global challenge in the internet era. Photonics technologies are at the frontline of research, aiming at providing the ultimate system capable of ending the cybercrime industry by changing the way information is treated and protected now and in the long run. Such perspective discusses some of the current challenges as well as opportunities that classical and quantum systems open in the field of cryptography as both a science and an engineering.PostprintPeer reviewe

The influence of physical activity performed at 20-40 years of age on cardiovascular outcomes in medical patients aged 65-75

Summary Introduction Several studies show that physical activity can reduce the risk of cardiovascular disease, but the vast majority of these focus on the short- to intermediate-term benefits or refer to very specific populations. This observational study was conducted to determine whether physical activity performed during the third or fourth decade of life influences the occurrence of cardiovascular events in patients aged 65-75 years. Materials and methods We studied a cohort of 2191 unselected patients admitted to Internal Medicine Departments. Data were collected on the patients' medical history and their physical activity level when they were 20 to 40 years old. For the latter purpose, we used a specific questionnaire to assess the levels of physical activity related to the patients' job, daily life, leisure time, and sports. Results Almost half (44.2%) of the patients we evaluated reported moderate-intense physical activity when they were 20-40 years old. Around one third (35.8%) of the patients had experienced at least one major cardiovascular event, and there was a slight trend towards fewer cardiovascular events in patients with histories of physical activity (mean risk reduction: 4%, multivariate analysis). More evident benefits were observed in the subgroup of patients with diabetes, where cardiovascular outcomes were much better in patients who had been physically active than in those with sedentary life-styles (mean risk reduction: 24%). Conclusions Given its design, our study may have underestimated the cardiovascular benefits of physical activity. Nonetheless, our results suggest that moderate-intense exercise during young adulthood may have limited beneficial effects on cardiovascular disease in old age, except in specific high-risk populations (diabetic patients). More evident benefits are probably associated with regular physical activity throughout life

Initial Experience with Radical Prostatectomy Following Holmium Laser Enucleation of the Prostate

BACKGROUND: Although an increasing number of prostate cancer (PCa) patients received holmium laser enucleation of the prostate (HoLEP) previously for benign prostatic obstruction (BPO), there is still no evidence regarding the outcomes of radical prostatectomy (RP) in this setting. OBJECTIVE: To assess functional and oncological results of RP in PCa patients who received HoLEP for BPO previously in a contemporary multi-institutional cohort. DESIGN, SETTING, AND PARTICIPANTS: A total of 95 patients who underwent RP between 2011 and 2019 and had a history of HoLEP were identified in two institutions. Functional as well as oncological follow-up was prospectively assessed and retrospectively analyzed. INTERVENTION: RP following HoLEP compared with RP without previous transurethral surgery. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients with complete follow-up data were matched with individuals with no history of BPO surgery using propensity score matching. Complications were assessed using the Clavien-Dindo scale. RESULTS AND LIMITATIONS: The median follow-up was 50.5 mo. We found no significant impact of previous HoLEP on positive surgical margin rate (14.0% [HoLEP] vs 18.8% [no HoLEP], p =  0.06) and biochemical recurrence-free survival (hazard ratio 0.74, 95% confidence interval [CI] 0.32-1.70, p =  0.4). Patients with a history of HoLEP had increased 1-yr urinary incontinence rates after RP. After adjusting for confounders, no significant impact of previous HoLEP was found (odds ratio [OR] 0.87, 95% CI 0.74-1.01; p = 0.07). Previous HoLEP did not hamper 1-yr erectile function recovery (OR 1.22, 95% CI 1.05-1.43; p =  0.01). Limitations include retrospective design and small sample size. CONCLUSIONS: RP after previous HoLEP is surgically feasible, with low complication rates and no negative impact on biochemical recurrence-free survival. However, in a multivariable analysis, we observed significantly worse 1-yr continence rates in patients after previous HoLEP. PATIENT SUMMARY: In the current study, we assessed the oncological and functional outcomes of radical prostatectomy in patients who underwent holmium laser enucleation of the prostate (HoLEP) previously due to prostatic bladder outlet obstruction. A history of HoLEP did not hamper oncological results, 1-yr continence, and erectile function recovery

Broadband Holography via Structured Black Silicon Nano-Antennas

Computer-generated holograms have wide applications in different fields of optics, ranging from imaging, data storage, to security.Herein, we report a new method for the fabrication of large-scale computer-generated holograms from an inexpensive material, such as Silicon. Our approach exploits dry etching to create a series of broadband nanoantennas, which can tune the reflectivity of Si from an average of 0.35 to 0.1 in the entire visible range. We demonstrated the realisation of different images at wavelengths of 450 nm, 532 nm, and 632 nm with an efficiency of 10%, 14%, and 12%, respectively, thus opening up the application of large-scale broadband computer-generated holographic surfaces

Clean Carbon Cycle via High‐Performing and Low‐Cost Solar‐Driven Production of Freshwater

While renewable power available worldwide costs increasingly less than the least expensive option based on fossil fuels, countries continue to increase their coal-fired capacity, which should conversely fall by 80% within a decade to limit global warming effects. To address the challenges to the implementation of such an aim, here, a path is explored that leverages on a previously unrecognized aspect of coal, opening to a new solar-driven carbon cycle that is environmentally friendly. By engineering the porosity matrix of coal into a suitably designed compressed volumetric structure, and by coupling it with a network of cotton fibers, it is possible to create a record performing device for freshwater production, with a desalination rate per raw material cost evaluated at 1.39 kg h − 1 $ − 1 at one sun intensity. This value is between two and three times higher than any other solar desalination device proposed to date. These results could envision a clean and socially sustainable cycle for carbon materials that, while enabling an enhanced water economy with global access to freshwater and sanitation, poses zero risks of reinjecting C O 2 into the environment through competing economies in the fossil's market