Electro-optically tunable microring resonators in lithium niobate

Optical microresonators have recently attracted a growing attention in the photonics community. Their applications range from quantum electro-dynamics to sensors and filtering devices for optical telecommunication systems, where they are likely to become an essential building block. The integration of nonlinear and electro-optical properties in the resonators represents a very stimulating challenge, as it would incorporate new and more advanced functionality. Lithium niobate is an excellent candidate material, being an established choice for electro-optic and nonlinear optical applications. Here we report on the first realization of optical microring resonators in submicrometric thin films of lithium niobate. The high index contrast films are produced by an improved crystal ion slicing and bonding technique using benzocyclobutene. The rings have radius R=100 um and their transmission spectrum has been tuned using the electro-optic effect. These results open new perspectives for the use of lithium niobate in chip-scale integrated optical devices and nonlinear optical microcavities.Comment: 15 pages, 8 figure

Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs

Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90mg AAE/g dw and 783.48mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 mu g/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.FCT, Fundacao para a Ciencia e a Tecnologia of Portugal [SFRH/BSA/139/2014

Predviđanje retencije β-diketonato kompleksa u TLC sistemima na silika-gelu primenom kvantitativnog odnosa strukture i retencije

Quantitative structure retention relationships for a series of 30 mixed beta-diketonato complexes of cobalt(III), chromium(III) and ruthenium(III) were derived by multiple linear regression analyses using molecular descriptors obtained by quantum chemical calculations. The retention parameters were obtained by thin layer chromatography on silica gel using mono and two-component solvent systems. The molecular descriptors included in the multiple linear regression analysis were molecular weight, molecular volume, surface area, hydrophilic lipophilic balance, percent hydrophilic surface area, dipole moment, polarizability, refractivity, energy of the highest occupied molecular orbital and energy of the lowest unoccupied molecular orbital. High agreement between the experimental and predicted retention parameters was obtained when polarizability and the hydrophilic lipophilic balance were used as the molecular descriptors. Comparison of the models with those established on polyacrylonitrile showed that the structure of the sorbent is responsible for the chromatographic behaviour of the same compounds. The presented models can be used for the prediction of the retention of new solutes in screening chromatographic systems.U ovom radu kvantifikovan je odnos strukture i retencije 30 mešovitih β-diketonato kompleksa kobalta(III), hroma(III) i rutenijuma(III) primenom multilinearne regresione analize korišćenjem molekulskih deskriptora, koji su dobijeni pomoću kvantno-hemijskih izračunavanja. Retencioni parametri su dobijeni tankoslojnom hromatografijom na silika-gelu primenom mono-i dvokomponetnih rastvarača. Molekulski deskriptori koji su uključeni u multilinearnu regresionu analizu su molekulska težina, molekulska zapremina, površina, hidrofilni-lipofilni balans, procenat hidrofilne površine, dipolni momenat, polarizabilnost, refraktivnost, energija najviše zauzete molekulske orbitale i energija najniže prazne molekulske orbitale. Dobijena je zadovoljavajuća korelacija između eksperimentalnih retencionih parametara i retencionih parametara predviđenih postavljenim modelima, koji sadrže polarizabilnost i hidrofilni-lipofilni balans kao deskriptore. Poređenja ovih modela sa modelima dobijenim na poliakrilonitrilnom sorbentu, za ista jedinjenja, pokazuju da je struktura sorbenta odgovorna za hromatografsko ponašanje. Ovi modeli se mogu koristiti za predviđanje retencije novih jedinjenja u datim hromatografskim sistemima

Predviđanje retencije β-diketonato kompleksa u TLC sistemima na silika-gelu primenom kvantitativnog odnosa strukture i retencije

Quantitative structure retention relationships for a series of 30 mixed beta-diketonato complexes of cobalt(III), chromium(III) and ruthenium(III) were derived by multiple linear regression analyses using molecular descriptors obtained by quantum chemical calculations. The retention parameters were obtained by thin layer chromatography on silica gel using mono and two-component solvent systems. The molecular descriptors included in the multiple linear regression analysis were molecular weight, molecular volume, surface area, hydrophilic lipophilic balance, percent hydrophilic surface area, dipole moment, polarizability, refractivity, energy of the highest occupied molecular orbital and energy of the lowest unoccupied molecular orbital. High agreement between the experimental and predicted retention parameters was obtained when polarizability and the hydrophilic lipophilic balance were used as the molecular descriptors. Comparison of the models with those established on polyacrylonitrile showed that the structure of the sorbent is responsible for the chromatographic behaviour of the same compounds. The presented models can be used for the prediction of the retention of new solutes in screening chromatographic systems.U ovom radu kvantifikovan je odnos strukture i retencije 30 mešovitih β-diketonato kompleksa kobalta(III), hroma(III) i rutenijuma(III) primenom multilinearne regresione analize korišćenjem molekulskih deskriptora, koji su dobijeni pomoću kvantno-hemijskih izračunavanja. Retencioni parametri su dobijeni tankoslojnom hromatografijom na silika-gelu primenom mono-i dvokomponetnih rastvarača. Molekulski deskriptori koji su uključeni u multilinearnu regresionu analizu su molekulska težina, molekulska zapremina, površina, hidrofilni-lipofilni balans, procenat hidrofilne površine, dipolni momenat, polarizabilnost, refraktivnost, energija najviše zauzete molekulske orbitale i energija najniže prazne molekulske orbitale. Dobijena je zadovoljavajuća korelacija između eksperimentalnih retencionih parametara i retencionih parametara predviđenih postavljenim modelima, koji sadrže polarizabilnost i hidrofilni-lipofilni balans kao deskriptore. Poređenja ovih modela sa modelima dobijenim na poliakrilonitrilnom sorbentu, za ista jedinjenja, pokazuju da je struktura sorbenta odgovorna za hromatografsko ponašanje. Ovi modeli se mogu koristiti za predviđanje retencije novih jedinjenja u datim hromatografskim sistemima

Significance of anatomical variations of the lateral circumflex femoral artery for the tensor fasciae latae flapping

The tensor fasciae latae (TFL) muscle is commonly used in plastic and reconstructive surgery as a transpositional or a free flap, in order to repair different kinds of defects. In most cases its vascularisation is provided by an ascending branch of lateral circumflex femoral artery (LCFA), which gives different numbers of branches and enters the TFL muscle in different manners. The represented study deals with the arterial vascularisation of the TFL muscle: the entrance of the vascular stalk branches; variations of the LCFA bifurcation’s angle; and the skin area of vascularisation. The study was performed on both lower limbs of a 100 foetal and 10 adult cadavers. The LCFA was injected with micropaque solution, afterwards fixed and preserved in 10% formalin solution. Microdissection was performed under magnifying glass and surgical microscope. Analysis of adult cadavers was performed to determine the skin area vascularised by perforating blood vessels from the TFL muscle, by injecting methylene-blue dye into the artery, prior to which all branches of the LCFA, besides the ascending branch, were ligated. The research of a 100 foetal cadavers showed that the LCFA with its ascending branch ensured the blood supply to the muscle. In 85% it gave two branches, the ascending and the descending one, with the angle of bifurcation circa 90o in 73% of cases. The ascending branch can give 0 or more terminal branches, or even form an arterial net. Skin area affected with dye ranged from 18 × 22 cm to 23 × 28 cm and is in positive correlation with the LCFA length and diameter. The understanding of the presented variations have an exceptional significance in planning and applying the TFL flap, especially free flap, in successful repairing and covering the defects, as well as in preventing postoperative complications

An objective comparison of cell-tracking algorithms

We present a combined report on the results of three editions of the Cell Tracking Challenge, an ongoing initiative aimed at promoting the development and objective evaluation of cell segmentation and tracking algorithms. With 21 participating algorithms and a data repository consisting of 13 data sets from various microscopy modalities, the challenge displays today's state-of-the-art methodology in the field. We analyzed the challenge results using performance measures for segmentation and tracking that rank all participating methods. We also analyzed the performance of all of the algorithms in terms of biological measures and practical usability. Although some methods scored high in all technical aspects, none obtained fully correct solutions. We found that methods that either take prior information into account using learning strategies or analyze cells in a global spatiotemporal video context performed better than other methods under the segmentation and tracking scenarios included in the challenge

Massage-like stroking boosts the immune system in mice

Recent clinical evidence suggests that the therapeutic effect of massage involves the immune system and that this can be exploited as an adjunct therapy together with standard drug-based approaches. In this study, we investigated the mechanisms behind these effects exploring the immunomodulatory function of stroking as a surrogate of massage-like therapy in mice. C57/BL6 mice were stroked daily for 8 days either with a soft brush or directly with a gloved hand and then analysed for differences in their immune repertoire compared to control non-stroked mice. Our results show that hand-but not brush-stroked mice demonstrated a significant increase in thymic and splenic T cell number (p lt 0.05; p lt 0.01). These effects were not associated with significant changes in CD4/CD8 lineage commitment or activation profile. The boosting effects on T cell repertoire of massage-like therapy were associated with a decreased noradrenergic innervation of lymphoid organs and counteracted the immunosuppressive effect of hydrocortisone in vivo. Together our results in mice support the hypothesis that massage-like therapies might be of therapeutic value in the treatment of immunodeficiencies and related disorders and suggest a reduction of the inhibitory noradrenergic tone in lymphoid organs as one of the possible explanations for their immunomodulatory function

Hybrid off-river augmentation system as an alternative raw water resource: the hydrogeochemistry of abandoned mining ponds

The use of water from abandoned mining ponds under a hybrid off-river augmentation system (HORAS) has been initiated as an alternative water resource for raw water. However, it raises the questions over the safety of the use of such waters. In this study, the hydrogeochemical analysis of the waters is presented to assess the degree to which the water has been contaminated. Comparisons were made between sampling sites, i.e. abandoned mining ponds, active sand mining ponds and the receiving streams within Bestari Jaya, Selangor River basin. The aqueous geochemistry analysis showed different hydrochemical signatures of major elements between sites, indicating different sources of minerals in the water. Discharges from the sand mining ponds were found to contain elevated availability of dissolved concentrations of iron, manganese, lead, copper and zinc, among others. However, the quality of the water (from the main river) that is supplied for potable water consumption is at a satisfactory level despite being partly sourced from the abandoned mining ponds. In fact, all the metal concentrations detected were well below the Malaysia Ministry of Health guideline limits for untreated raw water. In addition, the results of the geochemical index analysis (i.e. geoaccumulation index, enrichment factor and modified contamination factor) showed that the rivers and abandoned mining ponds were generally unpolluted with respect to the metals found in sediments

Effect of activated charcoal, abscisic acid and polyethylene glycol on maturation, germination and conversion of Aesculus hippocastanum androgenic embryos

The influence of activated charcoal (AC), abscisic acid (ABA) and polyethylene glycol (PEG) on the maturation and conversion of horse chestnut (Aesculus hippocastanum L.) androgenic embryos weretested. Androgenic embryos originating from microspores and anther culture were maturated over 90 days. Androgenic embryos on media containing PEG (50 g l-1), in combination with AC (1 g l-1) showed arapid development of embryos in the cotyledonary stage and lowered percentage of abnormal structures. The best results of androgenic microspore embryo germination were observed on media supplemented with AC alone (99%) and in combination with PEG (100%). Also, the greatest number of androgenic microspore plants (18%) and androgenic anther plants (12%) were formed on media enriched with 1 % AC. Lowest germination percentages of 37 and 39% in microspore culture and 33 and38% in anther culture were obtained on maturation media with ABA 20 mg l-1 alone and in combination with AC 1g l-1. Flow cytometric analysis showed that most of the androgenic embryos were haploid, corresponding to their microspore origin, while half of these became diploid after maturation for 90 days. All regenerants originating from microspore culture were haploid immediately after germination, but only 10% embryos re ained haploidity after 3 years subculturing, while 10.5% were diploid, 73.5% tetraploid and 6% octaploid on hormone-free medium. Unlike those from anther culture, after 3 years of subculturing on hormone-free medium, there were no haploid regenerant from anther culture, while8.5% were diploid, 81% tetraploid and 10.5% octaploid