Roles of superchirality and interference in chiral plasmonic biodetection

Chiral plasmonic nanostructures enable ≤pg detection and characterization of biomaterials. The sensing capabilities are associated with the chiral asymmetry of the near fields, which locally can be greater than equivalent circularly polarized light, a property referred to as superchirality. However, sensing abilities do not simply scale with the magnitude of superchirality. We show that chiral molecular sensing is correlated to the thickness of a nanostructure. This observation is reconciled with a previously unconsidered interference mechanism for the sensing phenomenon. It involves the “dissipation” of optical chirality into chiral material currents through the interference of fields generated by two spatially separated chiral modes. The presence of a chiral dielectric causes an asymmetric change in the phase difference, resulting in asymmetric changes to chiroptical properties. Thus, designing a chiral plasmonic sensor requires engineering a substrate that can sustain both superchiral fields and an interference effect

Surgical management of proximal fibular tumors: A report of 12 cases

Background/aim Aggressive benign or malignant tumors in the proximal fibula may require en bloc resection of the fibular head, including the peroneal nerve and lateral collateral ligament. Here, we report the treatment outcomes of 12 patients with aggressive benign or malignant proximal fibula tumors. Patients and methods Four patients with osteosarcoma and 1 patient with Ewing\u27s sarcoma were treated with intentional marginal resections after effective chemotherapy, and 4 patients underwent fibular head resections without ligamentous reconstruction. Clinical outcomes were investigated. Results The mean Musculoskeletal Tumor Society scores were 96% and 65% in patients without peroneal nerve resection and those with nerve resection, respectively. No patients complained of knee instability. Conclusion Functional outcomes after resection of the fibular head were primarily influenced by peroneal nerve preservation. If patients are good responders to preoperative chemotherapy, malignant tumors may be treated with marginal excision, resulting in peroneal nerve preservation and good function. © 2016 The AuthorsEmbargo Period 12 month

Evaluation of antigen-positive toxin-negative enzyme immunoassay results for the diagnosis of toxigenic Clostridium difficile infection

Clostridium difficile (C. difficile)-associated diarrhea (CDAD) is a challenging nosocomial infectious disease. C. DIFF Quik Chek Complete assay is widely used to detect glutamate dehydrogenase (GDH) antigen and toxin A/B of C. difficile simultaneously. However, the interpretation of GDH positive/toxin negative results is problematic.We performed a retrospective study of patients with GDH positive/toxin negative results to determine the probability of detecting toxigenic C. difficile and its risk factors. Between April 2012 and March 2017, we investigated cultures of fecal specimens followed by toxin detection tests. The clinical histories of patients with and without toxigenic C. difficile were compared using univariate- and multivariate-analyses. In total, 2675 patients were examined using C. Diff Quik Chek Complete assay. Among 356 GDH positive/toxin negative patients, cultures were performed in 220 cases and toxigenic C. difficile was recovered from 139 (63.2%) specimens. Patients with toxigenic C. difficile had significantly lower body mass index than those without. Over half the GDH positive/toxin negative patients were infected with toxigenic C. difficile. Lower BMI was a CDAD risk factor in this patient population. These data can be utilized to initiate isolation and clinical interventions before confirmatory test results are available

Certification of butyltins and phenyltins in marine sediment certified reference material by species-specific isotope-dilution mass spectrometric analysis using synthesized (118)Sn-enriched organotin compounds

A new marine sediment certified reference material, NMIJ CRM 7306-a, for butyltin and phenyltin analysis has been prepared and certified by the National Metrological Institute of Japan at the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). Candidate sediment material was collected at a bay near industrial activity in Japan. After air-drying, sieving, and mixing the material was sterilized with γ-ray irradiation. The material was re-mixed and packaged into 250 glass bottles (15 g each) and these were stored in a freezer at −30 °C. Certification was performed by use of three different types of species-specific isotope-dilution mass spectrometry (SSID–MS)—SSID–GC–ICP–MS, SSID–GC–MS, and SSID–LC–ICP–MS, with (118)Sn-enriched organotin compounds synthesized from (118)Sn-enriched metal used as a spike. The (118)Sn-enriched mono-butyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were synthesized as a mixture whereas the (118)Sn-enriched di-phenyltin (DPhT) and triphenyltin (TPhT) were synthesized individually. Four different extraction methods, mechanical shaking, ultrasonic, microwave-assisted, and pressurized liquid extraction, were adopted to avoid possible analytical bias caused by non-quantitative extraction and degradation or inter-conversion of analytes in sample preparations. Tropolone was used as chelating agent in all the extraction methods. Certified values are given for TBT 44±3 μg kg(−1) as Sn, DBT 51 ± 2 μg kg(−1) as Sn, MBT 67 ± 3 μg kg(−1) as Sn, TPhT 6.9 ± 1.2 μg kg(−1) as Sn, and DPhT 3.4 ± 1.2 μg kg(−1) as Sn. These levels are lower than in other sediment CRMs currently available for analysis of organotin compounds

Background Factors Affecting Visual Acuity at Initial Visit in Eyes with Central Retinal Vein Occlusion : Multicenter Study in Japan

Purpose: To determine the baseline characteristics of patients with central retinal vein occlusion (CRVO) that were significantly associated with the best-corrected visual acuity (BCVA) at the initial examination. Methods: This was a retrospective multicenter study using the medical records registered in 17 ophthalmological institutions in Japan. Patients with untreated CRVO (≥20-years-of-age) who were initially examined between January 2013 and December 2017 were studied. The patients’ baseline factors that were significantly associated with the BCVA at the initial examination were determined by univariate and multivariate linear regression analyses. Results: Data from 517 eyes of 517 patients were analyzed. Univariate analyses showed that an older age (r = 0.194, p < 0.001) and the right eye (r = −0.103, p < 0.019) were significantly associated with poorer BCVA at the initial visit. Multivariate analyses also showed that an older age (β = 0.191, p < 0.001) and the right eye (β = −0.089, p = 0.041) were significantly associated with poorer BCVA at the initial visit. Conclusions: The results indicate that an older age, a known strong factor, and the right eye were significantly associated with poorer BCVA at the initial visit to the hospital. These results suggest that functional and/or anatomical differences between the right and left eyes may be involved in these results

A Versatile Intermediate for the Systematic Synthesis of all Regioisomers of myo-Inositol Phosphates

Inositol phosphate derivatives are usually synthesized by repeated protection-deprotection procedures, necessitating development of an independent synthetic route for each inositol derivative. Herein, a synthetic precursor for all regioisomers of inositol phosphate has been prepared. A cycloadduct obtained by the Diels-Alder reaction of trans-1-methoxy-3-trimethylsilyloxy-1,3-butadiene and methyl vinyl ketone was converted into an inositol derivative by sequential introduction and immediate protection of hydroxyl groups. Thus, the six hydroxyl groups of the obtained inositol derivative are differentiated by different protective groups that are cleavable under independent conditions. This would enable us to prepare all regioisomers of inositol phosphate derivative