ZnO nanorods for solar cells: Hydrothermal growth versus vapor deposition

Performance of dye-sensitized solar cells (DSSCs) based on ZnO nanorods prepared by hydrothermal and vapor-deposition methods has been investigated. In spite of their inferior optical properties, DSSCs based on hydrothermally grown rods exhibit higher power conversion efficiency, which can be attributed to the higher dye adsorption. Hydrothermally grown and vapor deposited nanorods also exhibit different dependence of photovoltaic performance on the annealing conditions of the rods, indicating significant effect of the native defects on the achievable photocurrent and power conversion efficiency. Efficiency of 0.22% is obtained for both as grown hydrothermally grown nanorods and vapor deposited nanorods annealed in oxygen at 200 °C. © 2008 American Institute of Physics.published_or_final_versio

Dye-sensitized solar cells using ZnO tetrapods

One dimensional (1D) ZnO nanostructures are of interest for applications in dye-sensitized solar cells (DSSCs) since they exhibit significantly improved electron transport compared to that in porous films. However, 1D nanostructures also have a significantly lower surface area than the porous films. Thus, the achieved solar cell efficiencies are typically much lower in spite of the improved charge transport. In this work, we investigated DSSCs based on ZnO tetrapods to achieve an increased surface area compared to that of 1D nanostructures. The cell performance as a function of the tetrapod film thickness and the dye used was studied. To further increase the surface area, mixed morphologies (tetrapods with nanoparticles) were also investigated. Under optimal conditions, an AM 1.5 power conversion efficiency of ∼1.2% was achieved. © 2008 American Institute of Physics.published_or_final_versio

NiOZnO light emitting diodes by solution-based growth

Heterojunction NiOZnO light emitting diodes have been fabricated using low temperature solution-based growth methods. While negligible light emission has been obtained for the as-grown NiO film, devices with annealed NiO film exhibit room-temperature electroluminescence (EL), which was attributed to the detrimental effects of nickel oxide hydroxide in as-grown NiO layers. The device performance can be further modified by insertion of the organic layers between NiO and ZnO and the EL spectra exhibited dependence on the bias voltage. For higher bias voltages, strong UV-violet emission peak can be obtained in spite of the dominance of defect emission in the photoluminescence spectra. © 2008 American Institute of Physics.published_or_final_versio

Assessment of median nerve mobility by ultrasound dynamic imaging in carpal tunnel syndrome diagnosis

2013 Joint UffC, EFTF and PFM SymposiumCarpal tunnel syndrome (CTS) is a common entrapment neuropathy. Nerve conduction studies (NCS) have been used as a standard for CTS diagnosis. Complementing NCS, ultrasound imaging provides anatomic information on pathologic changes of the median nerve, such as the reduced median nerve mobility. Motion of median nerve is dependent on mechanical characteristics, and body movements. The purpose of this study was therefore to measure transverse sliding patterns of the median nerve during fingers flexion and extension in ultrasound B-mode images for distinguishing healthy from CTS subjects, and to investigate any correlation between NCS severity and median nerve motion. Transverse ultrasound images were acquired from 19 normal, 15 mild, and 10 severe CTS subjects confirmed by NCS. In two-second acquisition, their fingers were initially in natural position; the median nerve was then moved toward the ulnar side and radius side in fingers flexion and extension, respectively. The displacements of the median nerve were calculated by the multilevel block-matching pyramid algorithm and averaged. All the average displacements at different acquisition times were then accumulated to obtain cumulative displacements, which were curve-fitted by polynomial function. To differentiate the normal from CTS cases, the R-squared, curvature, and amplitude of the fitted curves were computed, to evaluate the goodness, variation, and maximum value of the fit, respectively. Compared to the CTS patients, the normal subjects had higher R-square, curvature, and amplitude estimates. The three parameters were then inputted to a fuzzy c-means algorithm to classify normal cases and CTS ones. The diagnostic efficiency had an accuracy of 93.2%, a specificity of 100%, and a sensitivity of 88%. Further study includes measuring mechanical strain and stress at different neural sites to provide elasticity of the median nerve. © 2013 IEEE.published_or_final_versio

Effect of annealing on the performance of CrO3/ZnO light emitting diodes

Heterojunction CrO3/ZnO light emitting diodes have been fabricated. Their performance was investigated for different annealing temperature for ZnO nanorods. Annealing in oxygen atmosphere had significant influence on carrier concentration in the nanorods, as well as on the emission spectra of the nanorods. Surprisingly, annealing conditions, which yield the lowest band edge-to-defect emission ratio in the photoluminescence spectra, result in the highest band edge-to-defect emission ratio in the electroluminescence spectra. The influence of the native defects on ZnO light emitting diode performance is discussed. © 2009 American Institute of Physics.published_or_final_versio

Expanding genotype/phenotype of neuromuscular diseases by comprehensive target capture/NGS

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Cyclopia with shoulder dystocia leading to an obstetric catastrophe: a case report

<p>Abstract</p> <p>Introduction</p> <p>Cyclopia is a rare fetal malformation characterized by a single palpebral fissure and a proboscis associated with severe brain malformations. Approximately 1.05 in 100,000 births including stillbirths are identified as cyclopean. The prevalence is about one in 11,000 to 20,000 in live births and one in 250 during embryogenesis.</p> <p>Case presentation</p> <p>A 30-year-old Indian woman of Asian origin, sixth gravida, was referred to the labor room of our hospital. There were no ultrasound examinations performed during this pregnancy as our patient had not received regular antenatal care. We found out that the head of her baby was already outside the vulva but the remaining parts of the baby were not yet delivered. Further examination was carried out and a diagnosis of shoulder dystocia with intrauterine fetal demise was made. A stillborn baby boy of 3.5 kg was delivered using McRoberts' maneuver. The baby was suspected of having features of cyclopia and this was later confirmed by autopsy and anatomic correlation. The mother had a cervical tear which extended into the lower segment of her uterus, thus leading to the rupture of her uterus. There was a massive broad ligament hematoma on the left side of her uterus. A total abdominal hysterectomy was carried out.</p> <p>Conclusion</p> <p>Prenatal diagnosis by ultrasound examination might help in detecting cyclopia and preventing complications associated with this condition. However, in developing countries where women do not receive regular antenatal care and do not undergo prenatal diagnosis, such cases will go undetected. In our case report, the occurrence of shoulder dystocia could be coincidental, as no risk factors were previously noted.</p