Assessment of orthodontic treatment needs in patients with ß-thalassemia major and sickle cell disease.

Patients suffering from hemoglobinopathies may suffer from pathogic dental and orofacial features. This study aimed to assess the prevalence of malocclusion and the need for orthodontic treatment in patients with ß-thalassemia major (BTM) and sickle cell disease (SCD). The study was conducted on 311 blood transfusion-dependent patients with BTM or SCD and 400 healthy individuals aged 10 to 16. The types of malocclusion were evaluated based on Angle's classification and Dewey's modification, and their oral habits were recorded using a questionnaire. The need for orthodontic treatment was assessed through the Dental Health Component of the Index of Orthodontic Treatment Need (IOTN), and the data were compared with normal participants. The Index of Orthodontic Treatment Need-Dental Health Component (IOTN-DHC) assessment showed that patients had a higher prevalence of objective need for treatment (IOTN grades 4 and 5) compared to healthy children. The prevalence of class II malocclusion was significantly higher in patients. Patients showed significantly less Angle's Class I malocclusion compared to normal participants. Oral habits were presented in 61%, 64.15% and 62.4% of normal participants, BTM and SCD patients, respectively. The higher prevalence of Angle's class II malocclusion and higher percentage of IOTN grade 4 and 5 among BTM and SCD patients reveal the importance of early orthodontic assessment and intervention in children with BMT and SDC.

Ultra-compact, broadband adiabatic passage optical couplers in thin-film lithium niobate on insulator waveguides.

We report the first demonstration of broadband adiabatic directional couplers in thin-film lithium niobate on insulator (LNOI) waveguides. A three LN-waveguide configuration with each waveguide having a ridge cross section of less than 1 square micron, built atop a layer of SiO2 based on a 500-µm-thick Si substrate, has been designed and constructed to optically emulate a three-state stimulated Raman adiabatic passage system, with which a unique counterintuitive adiabatic light transfer phenomenon in a high coupling efficiency of >97% (corresponding to a >15 dB splitting ratio) spanning telecom S, C, and L bands for both TE and TM polarization modes has been observed for a 2-mm long coupler length. An even broader operating bandwidth of >800 nm of the device can be found from the simulation fitting of the experimental data. The footprint of the realized LNOI adiabatic coupler has been reduced by >99% compared to its bulk counterparts. Such an ultra-compact, broadband LNOI adiabatic coupler can be further used to implement or integrate with various photonic elements, a potential building block for realizing large-scale integrated photonic (quantum) circuits in LN.

Photon Pairs from Resonant Metasurfaces.

All-dielectric optical metasurfaces are a workhorse in nano-optics, because of both their ability to manipulate light in different degrees of freedom and their excellent performance at light frequency conversion. Here, we demonstrate first-time generation of photon pairs via spontaneous parametric-down conversion in lithium niobate quantum optical metasurfaces with electric and magnetic Mie-like resonances at various wavelengths. By engineering the quantum optical metasurface, we tailor the photon-pair spectrum in a controlled way. Within a narrow bandwidth around the resonance, the rate of pair production is enhanced up to 2 orders of magnitude, compared to an unpatterned film of the same thickness and material. These results enable flat-optics sources of entangled photons-a new promising platform for quantum optics experiments.

Second-Harmonic Generation in Resonant Nonlinear Metasurfaces Based on Lithium Niobate.

Lithium niobate is an excellent and widely used material for nonlinear frequency conversion due to its strong optical nonlinearity and broad transparency region. Here, we report the fabrication and experimental investigation of resonant nonlinear metasurfaces for second-harmonic generation based on thin-film lithium niobate. In the fabricated metasurfaces, we observe pronounced Mie-type resonances leading to enhanced second-harmonic generation in the direction normal to the metasurface. We find the largest second-harmonic generation efficiency for the resonance dominated by the electric contributions because its specific field distribution enables the most efficient usage of the largest element of the lithium niobate nonlinear susceptibility tensor. This is confirmed by polarization-resolved second-harmonic measurements, where we study contributions from different elements of the nonlinear susceptibility tensor to the total second-harmonic signal. Our work facilitates establishing lithium niobate as a material for resonant nanophotonics.

Molecular analysis of patients with severe congenital factor X deficiency: First report from north and northwest of Iran.

Background Congenital FX deficiency is an extremely rare autosomal recessive disorder, mostly present in regions with a high rate of consanguinity, with an incidence of approximately 1:2,000,000 in the general population. The aim of this study was to evaluate the clinical manifestations and to provide a molecular analysis of 14 patients with homozygous factor X deficiency. Methods We evaluated the results of clinical and molecular characterization of 14 new cases (10 males, 4 females aged from 4 to 17 years) of FXD (FX activity <1%) in North and Northwest of Iran. FXD was diagnosed by clinical findings and routine laboratory tests. The PCR products of all the eight exons and their intron-exon boundaries were sequenced using DNA sequencer. Results Mean age of patients and mean age at diagnosis were 9 and 2.5 years, respectively. The molecular analysis revealed five different mutations, all of them were previously described. Molecular analysis showed five different homozygous and double heterozygous mutations including Arg-1Thr, Cys81Tyr, Gly78Asp, IVS1+3, and IVS2-3. Discussion The study of a large population of factor X patients from three institutions indicated that FXD was one of the most serious among rare bleeding disorders and that factor X gene mutation may be related to bleeding tendency in patients.

Comparison of human adipose-derived stem cells and chondroitinase ABC transplantation on locomotor recovery in the contusion model of spinal cord injury in rats.

OBJECTIVES: Spinal cord injury (SCI) is one of the most serious clinical diseases and its treatment has been a subject of interest to researchers. There are two important therapeutic strategies in the treatment of SCI: replacing lost tissue cells through cells implantation and scar elimination. Therefore, in this study we used human adipose-derived stem cells (hADSCs) implantation and injection of Chondroitinase ABC. Aim of present study was to answer to this question: which one is more efficient for Improvement of locomotor recovery after SCI in rat? Transplantation of hADSCs or injection of ChABC. MATERIALS AND METHODS: The spinal cord of rats was injured by contusion using a weight-drop at the level of T8-9, the hADSCs and Chondroitinase ABC were infused in to the spinal cord tissue after injury. BBB test was performed and recorded for each animal weekly for 8 weeks. After the 8(th) weeks, Serial cross-sections were stained with cresyl violet and examined under a light microscope and area of cavity in the spinal cord was measured. RESULTS: At 8(th) weeks after injection, hADSCs and ChABC significantly promote locomotor function (P<0.01) and spinal cords of hADSCs and ChABC group had cavities much smaller than those of the control group (P<0.001). CONCLUSION: Results of the present study shows dealing with inappropriate neuro-inhibitory environment and glial scar by ChABC have equal role compare to cell therapy (with hADSCs) for improving motor function after SCI and this result in adoption of proper therapeutic strategies for SCI intervention is important.