Broadband and large-area optical chirality generated by an achiral metasurface under achiral excitation

Optical chirality plays an essential role in chiral light-matter interactions with broad applications in sensing and spectroscopy. Conventional methods of generating optical chirality usually employ chiral structures or chiral excitations. Here, we propose to use an achiral metasurface consisting of gold disk array excited by a linearly polarized light to generate optical chirality. Using full-wave numerical simulations, we show that the metasurface can give rise to large-area optical chirality of the same sign for the wavelength ranging from 1.2 um to 1.5 um. The magnitude of the chirality is comparable to that of circularly polarized plane waves. The emergence of the optical chirality can be attributed to the asymmetric polarization singularity lines (C lines) in the near fields of the metasurface. We further explore the application of the proposed metasurface in chiral discriminations by simulating the absorption of chiral helix particles immersed in the near fields, and demonstrate that the left-handed and right-handed helix particles give rise to different absorptions. The phenomenon can be understood using an analytical theory based on the dipole approximation, which predicts differential absorption quantitatively agrees with the numerical simulation results. Our study uncovers the subtle relationship between near-field optical chirality, polarization singularities, and symmetry. The results can find applications in optical sensing, chiral quantum optics, and optical manipulations of small particles.Comment: 6 pages, 5 figure

Complete genome sequence of a Megalocytivirus (family Iridoviridae) associated with turbot mortality in China

<p>Abstract</p> <p>Background</p> <p>Turbot reddish body iridovirus (TRBIV) causes serious systemic diseases with high mortality in the cultured turbot, <it>Scophthalmus maximus</it>. We here sequenced and analyzed the complete genome of TRBIV, which was identified in Shandong province, China.</p> <p>Results</p> <p>The genome of TRBIV is a linear double-stranded DNA of 110,104 base pairs, comprising 55% G + C. Total 115 open reading frames were identified, encoding polypeptides ranging from 40 to 1168 amino acids. Amino acid sequences analysis revealed that 39 of the 115 potential gene products of TRBIV show significant homology to other iridovirus proteins. Phylogenetic analysis of conserved genes indicated that TRBIV is closely related to infectious spleen and kidney necrosis virus (ISKNV), rock bream iridovirus (RBIV), orange-spotted grouper iridovirus (OSGIV), and large yellow croaker iridovirus (LYCIV). The results indicated that TRBIV belongs to the genus <it>Megalocytivirus </it>(family Iridoviridae).</p> <p>Conclusions</p> <p>The determination of the genome of TRBIV will provide useful information for comparative study of Megalocytivirus and developing strategies to control outbreaks of TRBIV-induced disease.</p

Efficacy of endoluminal interventional therapy in diabetic peripheral arterial occlusive disease: a retrospective trial

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to assess the efficacy of interventional therapy for peripheral arterial occlusive disease and the difference between diabetic patients and non-diabetic patients.</p> <p>Methods</p> <p>139 consecutive patients between September 2006 and September 2010 who underwent percutaneous lower extremity revascularization for arterial lesions were divided into diabetes group (n = 62) and non-diabetes group (n = 77). Before intervention, rest ankle brachial indexes and three dimensional computed tomography angiography from abdominal aorta to tiptoe were performed. The interventional treatments included angioplasty with or without stenting. The clinical outcomes included rest ankle-brachial indexes, primary patency rates, secondary patency rates and limb-salvage rates for 6-month, 12-month, 24-month and 36-month after treatment. The primary and secondary patency rates of all interventions and the limb-salvage rates of the patients are illustrated by Kaplan-Meier curves and compared by log-rank analysis.</p> <p>Results</p> <p>The interventional operation success rates were 98.4% (61/62) in diabetes group and 100% (77/77) in non-diabetes group. The re-interventional operation success rates were 85.7% (18/21) in diabetes group and 76.9% (20/26) in non-diabetes group. The mean value of ankle brachial indexes was significantly increased after intervention (0.397 ± 0.125 versus 0.779 ± 0.137, t = -25.780, <it>P </it>< 0.001) in diabetes group and (0.406 ± 0.101 versus 0.786 ± 0.121, t = -37.221, <it>P </it>< 0.001) in non-diabetes group. Perioperative 30-day mortality was 0%. Major complications included groin hematoma in 7.2%, and pseudoaneurysm formation 2.2%. In diabetes group, 6, 12, 24, and 36-month primary patency rates were 88.7% ± 4.0%, 62.3% ± 6.6%, 55.3% ± 7.0%, and 46.5% ± 7.5%; secondary patency rates were 93.5% ± 3.1%, 82.3% ± 5.1%, 70.8% ± 6.5%, and 65.7% ± 7%; limb-salvage rates were 95.2% ± 2.7%, 87.7% ± 4.4%, 85.5% ± 4.8%, and 81.9% ± 5.8%. In non-diabetes group, 6, 12, 24, and 36-month primary patency rates were 90.9% ± 3.3%, 71.8% ± 5.4%, 71.8% ± 5.4%, and 60.9% ± 6.2%; secondary patency rates were 96.1% ± 2.2%, 91.6% ± 3.3%, 82.7% ± 4.8%, and 71.8% ± 6.2%; limb-salvage rates were 97.4% ± 1.8%, 94.4% ± 2.7%, 90.6% ± 3.7%, and 83.1% ± 5.4%. The differences between two groups were not significant (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>With a low risk of morbidity and mortality, the percutaneous revascularization accepted by patients does not affect ultimate necessary surgical revascularization and consequently should be considered as the preferred therapy for chronic lower extremity ischemia. The efficacy and prognosis of interventional therapy in diabetic patients is similar that in non-diabetic patients.</p

Fabrication and Properties of High-Content Keratin/Poly (Ethylene Oxide) Blend Nanofibers Using Two-Step Cross-Linking Process

High-content keratin/poly (ethylene oxide) (PEO) (90/10) blend nanofibers were prepared by electrospinning combined with a two-step cross-linking process. The keratin/PEO aqueous solution was firstly mixed with ethylene glycol diglycidyl ether (EGDE) as cross-linker and then electrospun into nanofibers. The resulting nanofibrous mats were cross-linked with EGDE vapor to decrease the solubility of nanofibers in water. The morphologies and properties of electrospun fibers were investigated by SEM, FTIR, TG, XRD, and contact angle testing, respectively. The results showed that the morphologies of nanofibers were uniform at the fiber average diameter of 300 nm with negligible bead defects by adding EGDE to keratin/PEO solutions. The cross-linking results showed that EGDE vapor could improve the hydrophobic property of blended nanofibers. The crystallinity of the keratin/PEO blend nanofiber mat increased from 13.14% for the uncross-linked sample to 21.54% and 35.15% for the first cross-linked and second cross-linked samples, respectively. Free defect nanofiber mats with high keratin content producing from this two-step cross-linking process are particularly promising for tissue engineering and cell-seeded scaffold

Analysis of independent risk factors for progression of different degrees of diabetic retinopathy as well as non-diabetic retinopathy among type 2 diabetic patients

PurposeTo study the independent risk factors for development of different degrees of diabetic retinopathy (DR) as well as non-DR (NDR) among type 2 diabetic patients.MethodsThis cross-sectional study included 218 patients with type 2 diabetes between January 2022 and June 2022. All the patients were divided into two groups: the DR group and the NDR group. The DR group was subdivided into the mild, moderate and severe non-proliferative DR (NPDR) group and the proliferative DR (PDR) group. Data recorded for all patients included age, gender, duration of diabetes, blood pressure, glycated hemoglobin (HbA1c), fasting blood glucose (FBG), blood lipids, best corrected visual acuity (BCVA), intraocular pressure (IOP), axial length (AL), anterior chamber depth (ACD), and renal function. Logistic regression methods were used to analyze the risk factors for DR.ResultsThe prevalence of DR in type 2 diabetes was 28.44%. The duration of diabetes, age, mean arterial pressure (MAP), HbA1c, FBG, urinary albumin/creatinine ratio (UACR), BCVA, AL, and ACD were significantly different between the DR and the NDR groups (p &lt; 0.05). Multivariate logistic regression analysis identified age, FBG, UACR, and AL as the independent risk factors for DR (OR = 0.843, 2.376, 1.049, 0.005; p = 0.034, 0.014, 0.016, p &lt; 0.001).ConclusionYoung age, short AL, higher levels of FBG and UACR were the independent risk factors for the progression of DR in type 2 diabetes