The study of non-Hermitian systems with parity-time (PT) symmetry is a rapidly developing frontier. Realized in recent experiments, PT-symmetric classical optical systems with balanced gain and loss ...hold great promise for future applications. Here we report the experimental realization of passive PT-symmetric quantum dynamics for single photons by temporally alternating photon losses in the quantum walk interferometers. The ability to impose PT symmetry allows us to realize and investigate Floquet topological phases driven by PT-symmetric quantum walks. We observe topological edge states between regions with different bulk topological properties and confirm the robustness of these edge states with respect to PT-symmetry-preserving perturbations and PT-symmetry-breaking static disorder. Our results contribute towards the realization of quantum mechanical PT-synthetic devices and suggest exciting possibilities for the exploration of the topological properties of non-Hermitian systems using discrete-time quantum walks.
Full text
Available for:
IJS, NUK, SBMB, UL, UM, UPUK
Objectives
We aimed to evaluate the relationship between baseline renal function and changes in telomere length in Han Chinese.
Methods
The telomere restriction fragment (TRF) length of leukocytes in ...the peripheral blood was measured in healthy volunteers recruited in 2014. The estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine (Scr) and serum cystatin C (CysC)-eGFRcys and eGFRScr-cys through the Cockcroft-Gault formula (eGFRC-G) or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI / eGFRCKD-EPI) equation. The correlation between telomere length changes over time and renal function was analyzed.
Results
Leukocyte TRF lengths were negatively correlated to age (r = -0.393, p < 0.001) and serum CysC (r = -0.180, p < 0.01), while positively associated with eGFRCKD-EPI, eGFRC-G, eGFRcys, and eGFRScr-cys (r = 0.182, 0.122, 0.290, and 0.254 respectively, p < 0.01). The 3-year change of telomere length was 46 bp/years. When adjusted for age, the associations between telomere length changes and baseline, subsequent TRF lengths, and serum CysC were no longer present. No association was observed between TRF length changes and renal function.
Conclusion
The rate of telomere length changes was affected by age and baseline telomere length. The telomere length changes might be important markers for aging.
Aims: Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer, showing a mixture of hepatocellular and biliary features. Data suggest that most CHC arise from hepatic ...progenitor cells (HPCs). The aim was to investigate the origin of CHC.
Methods and results: Twelve cases of CHC were studied by immunohistochemistry for hepatocytic (hepPar1, α‐fetoprotein), cholangiocytic cytokeratin (CK) 7, CK19, hepatic progenitor cell (OV‐6), haematopoietic stem cell (c‐kit, CD34), as well as CD45 and chromogranin‐A markers. The combination of double‐fluorescence immunostaining consisted of HepPar1 with CK19, and c‐kit with OV‐6. All 12 cases demonstrated more or less transitional areas, with strands/trabeculae of small, uniform, oval‐shaped cells including scant cytoplasm and hyperchromatic nuclei embedded within a thick, desmoplastic stroma; however, two cases were found to consist entirely of such transitional areas. Simultaneous co‐expression of hepPar1 and CK7, or CK19, was demonstrated in 10/12 (83.3%) cases of CHC. c‐kit expression was noted in 10/12 (83.3%) cases, of which 7/10 (70%) showed co‐expression of OV‐6.
Conclusions: The results suggest that CHC are of HPC origin, supporting the concept that human hepatocarcinogenesis may originate from the transformation of HPCs.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
We present the results from the 43 GHz Very Long Baseline Array (VLBA) observations of 124 compact radio-loud active galactic nuclei (AGNs) that were conducted between 2014 November and 2016 May. The ...typical dimensions of the restoring beam in each image are about 0.5 mas × 0.2 mas. The highest resolution of 0.2 mas corresponds to a physical size of 0.02 pc for the lowest redshift source in the sample. The 43 GHz very long baseline interferometry (VLBI) images of 97 AGNs are presented for the first time. We study the source compactness on milliarcsecond and submilliarcsecond scales, and suggest that 95 sources in our sample are suitable for future space VLBI observations. By analyzing our data supplemented with other VLBA AGN surveys from the literature, we find that the core brightness temperature increases with increasing frequency below a break frequency ∼7 GHz, and decreases between ∼7 and 240 GHz but increases again above 240 GHz in the rest frame of the sources. This indicates that the synchrotron opacity changes from optically thick to thin. We also find a strong statistical correlation between radio and γ-ray flux densities. Our correlation is tighter than those in the literature derived from lower-frequency VLBI data, suggesting that the γ-ray emission is produced more cospatially with the 43 GHz VLBA core emission. This correlation can also be extrapolated to the unbeamed AGN population, implying that a universal γ-ray production mechanism might be at work for all types of AGNs.
Background
Diet and exercise during pregnancy have been used to prevent gestational diabetes mellitus (GDM) with some success.
Objective
To examine the effectiveness of lifestyle intervention on GDM ...prevention and to identify key effectiveness moderators to improve the prevention strategy.
Search strategy
Pubmed, Scopus, Cochrane, and cross‐references were searched.
Selection criteria
Randomised controlled trials (RCTs) evaluating lifestyle interventions during pregnancy for GDM prevention.
Data collection and analysis
Two independent reviewers extracted data. A random‐effects model was used to analyse the relative risk (RR) and 95% confidence interval (95% CI). Meta‐regressions and subgroup analyses were used to investigate important moderators of effectiveness.
Main results
Forty‐seven RCTs involving 15 745 participants showed that diet and exercise during pregnancy were preventive of GDM (RR 0.77, 95% CI 0.69–0.87). Four key aspects were identified to improve the preventive effect: targeting the high‐risk population; an early initiation of the intervention; the correct intensity and frequency of exercise; and gestational weight gain management. Although 24 RCTs targeted women who were overweight or obese, body mass index (BMI) failed to predict the effectiveness of an intervention. Instead, interventions are most effective in high‐incidence populations rather than simply in women who are overweight or obese. Furthermore, exercise of moderate intensity for 50–60 minutes twice a week could lead to an approximately 24% reduction in GDM.
Conclusion
The best strategy to prevent GDM is to target the high‐risk population predicted by risk evaluation models and to control the gestational weight gain of women through intensified diet and exercise modifications early in their pregnancy.
Tweetable
Four key effectiveness moderators of lifestyle interventions for GDM prevention.
Tweetable
Four key effectiveness moderators of lifestyle interventions for GDM prevention.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Development of efficient and durable oxygen evolution reaction (OER) catalysts has a direct impact on the water splitting efficiency and cost effectiveness. In this work, we report the successful ...synthesis of a new Ni(OH)
2
structure, strain-stabilized Ni(OH)
2
nanoribbons (NR-Ni(OH)
2
) two to three layers thick, with widths of 2-5 nm,
via
an electro-oxidation route. Conventional Ni(OH)
2
usually has negligible OER activity, while NR-Ni(OH)
2
shows high activity for the oxygen evolution reaction and an overpotential of 162 millivolts and furthermore exhibits long-term stability in alkaline electrolyte. The substantial reduction in the overpotential of NR-Ni(OH)
2
is due to its easier OOH* adsorption by the active four-coordinated Ni edge sites. The enhanced catalytic activity of NR-Ni(OH)
2
makes it an excellent candidate for industrial applications.
Development of efficient and durable oxygen evolution reaction (OER) catalysts has a direct impact on the water splitting efficiency and cost effectiveness.
Abstract Background The purpose of this study was to compare patient outcomes between immediate breast reconstruction (IBR) after mastectomy and mastectomy alone. Methods We conducted a comprehensive ...literature search of PUBMED, EMBASE, Web of Science, and Cochrane Library. The primary outcomes evaluated in this review were overall survival, disease-free survival and local recurrence. Secondary outcome was the incidence of surgical site infection. All data were analyzed using Review Manager 5.3. Results Thirty-one studies, involving of 139,894 participants were included in this paper. Pooled data demonstrated that women who had IBR after mastectomy were more likely to experience surgical site infection than those treated with mastectomy alone (risk ratios 1.51, 95% CI: 1.22–1.87; p = 0.0001). There were no significant differences in overall survival (hazard ratios 0.92, 95% CI: 0.80–1.06; p = 0.25) and disease-free survival (hazard ratios 0.96, 95% CI: 0.84–1.10; p = 0.54) between IBR after mastectomy and mastectomy alone. No significant difference was found in local recurrence between two groups (risk ratios 0.92, 95% CI: 0.75–1.13; p = 0.41). Conclusions Our study demonstrates that IBR after mastectomy does not affect the overall survival and disease-free survival of breast cancer. Besides, no evidence shows that IBR after mastectomy increases the frequency of local recurrence.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The interface between transition metal compounds provides a rich playground for emergent phenomena. Recently, significantly enhanced superconductivity has been reported for single-layer FeSe on ...Nb-doped SrTiO3 substrate. Yet it remains mysterious how the interface affects the superconductivity. Here we use in situ angle-resolved photoemission spectroscopy to investigate various FeSe-based heterostructures grown by molecular beam epitaxy, and uncover that electronic correlations and superconducting gap-closing temperature (Tg) are tuned by interfacial effects. Tg up to 75 K is observed in extremely tensile-strained single-layer FeSe on Nb-doped BaTiO3, which sets a record high pairing temperature for both Fe-based superconductor and monolayer-thick films, providing a promising prospect on realizing more cost-effective superconducting device. Moreover, our results exclude the direct correlation between superconductivity and tensile strain or the energy of an interfacial phonon mode, and highlight the critical and non-trivial role of FeSe/oxide interface on the high Tg, which provides new clues for understanding its origin.
AbstractGravity dams are important infrastructures, and their failure can affect public security. In this work, physical modeling was conducted to determine the dynamic responses and types of damage ...to gravity dams subjected to underwater explosions. Five tests under different impoundment levels, centrifugal accelerations, standoff distances, detonation depth, and equivalent weights were performed in a centrifuge. The mechanism of dynamic responses of the dam was analyzed. The peak strain and displacement by the shock wave and bubble pulse were both reached when the impulses of the dynamic loads were maximum. Different failure modes and degrees of damage were observed in the tests. When the explosive detonated in shallow water, a more substantial structural bending moment was generated by the shock wave to cause structural failure by bending. When the impoundment level was reduced, the dynamic responses were reduced due to the decrease in shock energy or impulse on the structure. However, new deformation or failure mode can be induced when the impoundment level is lower. Better understanding of the dynamic mechanism and proper control of the impoundment level would be helpful for dam protection.
PDF
