Investigating a subfertile couple

published_or_final_versio

Can the Hospital Anxiety and Depression (HAD) Scale be used on Chinese elderly in general practice?

A study was carried out in a general practice in Hong Kong to find out if the Hospital Anxiety and Depression (HAD) Scale could be used to detect psychological problems in Chinese elderly. The HAD Scale was translated into Cantonese and administered by an interviewer to 298 Chinese aged 60 or above before their doctor consultations. The acceptance rate of the Scale was 96% and each interview took only 5-10 min to complete. All 298 elderly understood and completed the HAD Scale. Validation of the results of the HAD Scale by the Clinical Interview Schedule (CIS) was done on a random sample of 100 elderly. Relative operating characteristic (ROC) analysis showed that the optimal cut-off points of the HAD Scale was a depression score of 6 and an anxiety score of 3. The sensitivity was 80%, specificity was 90%, OMR (overall misclassification rate) was 12%, positive predictive value was 67% and negative predictive value was 95%. Thirty-six per cent of the,elderly had scores above these cut-off points. More females than males had high anxiety scores. Nearly half of those with positive HAD scores were not known to have any psychological illness. The HAD Scale has great potential to be used as a screening instrument for psychological illnesses in Cantonese-speaking Chinese elderly all over the world.postprin

Human oviductal cells produces three glycoprotein fractions that stimulate mouse embryo development

published_or_final_versio

Properties of a hand-printed Chinese character recognizer based on contexted vector quantization

A hand-printed Chinese character recognizer based on Contextual Vector Quantization (CVQ) has been built previously. In this paper, several properties of the recognizer will be discussed and the recognizer of 4516 Chinese characters has a successful rate of 91.0%. Then the output of the recognizer is passed to a language model which when applied to recognize a passage of about 1200 characters raises the rate from 91.5% to 97.5%.published_or_final_versio

Influence of the device architecture to the ITO surface treatment effects on organic solar cell performance

In this work, we investigate the influence of different indium tin oxide (ITO) surface treatments on the performance of organic solar cells with different device architectures. Two layer cells with different layer hierarchy (ITO/copper phthalocyanine (CuPc)/fullereve (C60/Al and ITO/C 60/CuPc/Cu) and three layer cells with mixed layer inserted between CuPc and C60 were fabricated. We found that in all cases the short circuit current was the parameter which was most significantly affected by ITO surface treatment. However, the performance of the cells with C60 layer in contact with ITO was markedly less sensitive to the ITO surface treatments compared to the cells with CuPc in contact with ITO. The cells with C60 layer in contact with ITO also exhibited higher efficiency compared to the cells with CuPc in contact with ITO. We also fabricated two layer cells with structures ITO/CuPc/perylene tetracarboxylic acid diimide (PTCDI)/Al and ITO/PTCDI/CuPc/Cu. In this case, we also obtain higher efficiency and lower sensitivity to ITO properties when "n type" material is in contact with ITO. The best obtained AMI power conversion efficiency was 0.4% for ITO/PTCDI/CuPc/Cu cell and ITO/C60/CuPc:C60/CuPc/Cu cells.published_or_final_versio

Channel coding for progressive images in a 2-D time-frequency OFDM block with channel estimation errors.

Coding and diversity are very effective techniques for improving transmission reliability in a mobile wireless environment. The use of diversity is particularly important for multimedia communications over fading channels. In this work, we study the transmission of progressive image bitstreams using channel coding in a 2-D time-frequency resource block in an OFDM network, employing time and frequency diversities simultaneously. In particular, in the frequency domain, based on the order of diversity and the correlation of individual subcarriers, we construct symmetric n -channel FEC-based multiple descriptions using channel erasure codes combined with embedded image coding. In the time domain, a concatenation of RCPC codes and CRC codes is employed to protect individual descriptions. We consider the physical channel conditions arising from various coherence bandwidths and coherence times, leading to a range of orders of diversities available in the time and frequency domains. We investigate the effects of different error patterns on the delivered image quality due to various fade rates. We also study the tradeoffs and compare the relative effectiveness associated with the use of erasure codes in the frequency domain and convolutional codes in the time domain under different physical environments. Both the effects of intercarrier interference and channel estimation errors are included in our study. Specifically, the effects of channel estimation errors, frequency selectivity and the rate of the channel variations are taken into consideration for the construction of the 2-D time-frequency block. We provide results showing the gain that the proposed model achieves compared to a system without temporal coding. In one example, for a system experiencing flat fading, low Doppler, and imperfect CSI, we find that the increase in PSNR compared to a system without time diversity is as much as 9.4 dB

Nanocomposite solar cells - Influence of particle concentration, size and shape on the device performance

Solar cells based on poly(3-hexylthiophene) (P3HT) :TiO2 nanocomposite films were investigated. We studied the influence of the nanoparticle concentrations and different nanostructures (spherical particles with size ∼5 nm and ∼20-40 nm, and rods with diameter ∼10 nm and length ∼40 nm) on the performance of the nanocomposite solar cells. PL quenching and improved external quantum efficiency (EQE) was observed for all the nanocomposite devices compared to that of pristine P3HT solar cells. However, TiO2 (∼5 nm spheres) and TiO2 rods showed only small improvement in EQE. The small improvement for the 5 nm TiO 2 spheres was attributed to the lack of connectivity of nanoparticles for electron conduction. Therefore, the charge collection efficiency was limited. For TiO2 rods, the tendency of the rods to lie in the plane of substrates also limited the charge conduction and collection in the direction perpendicular to the substrates. Therefore, the improvement of the devices made by these nanoparticles was limited. For TiO2 (20-40 nm spheres) with optimal concentration, external quantum efficiency up to 15% and AM1 power conversion efficiency of 0.42% were obtained. The improvement in the efficiency was related to the improved morphology of the film and was attributed to the formation of percolation paths of TiO2 for electron conduction.published_or_final_versio

Indium-tin-oxide surface treatments: Influence on the performance of CuPc/C60 solar cells

The performance of organic solar cells was influenced by different indium tin oxide (ITO) surface treatments. The uses of Hall measurements, Seebeck coefficient measurements, surface sheet measurements, and surface probe microscopy to characterize ITO sustrates were discussed. The parameters of ITO such as work function, carrier concentration, sheet resistance and surface roughness were changed due to the surface treatments.published_or_final_versio

An interpenetrating network composite for a regenerative spinal disc application

Severe degeneration of the intervertebral disc has an immensely debilitating effect on quality of life that has become a serious health and economic burden throughout the world. The disc plays an integral role in biomechanical movement and support within the spine. The emergence of tissue engineering endeavours to restore the structural characteristics and functionality of the native tissue. Hydrogels have been widely investigated as a candidate for regeneration of the gelatinous nucleus pulposus due to its architectural resemblance and fluid retention characteristics. However, hydrogels are often limited due to small compressive stiffness and tear resistance, leading to extrusion complications. Reinforcement of the hydrogel network using polymeric scaffolds may address these issues of inadequate mechanical properties and implant instability. This study investigates the potential of a carrageenan gel-infused polycaprolactone scaffold for nucleus pulposus tissue engineering. Mechanical properties were characterised using viscoelastic and poroelastic frameworks via microindentation. The incorporation of polymeric reinforcement within the gels increased material stiffness to that comparable to the native nucleus pulposus, however permeability was significantly greater than native values. A preliminary cell evaluation culturing NIH 3T3s over 21 days suggested the incorporation of polymeric networks also enhanced cellular proliferation compared to gels alone

Genetics of Lumbar Disk Degeneration: Technology, Study Designs, and Risk Factors

Lumbar disk degeneration (LDD) is a common musculoskeletal condition. Genetic risk factors have been suggested to play a major role in its cause. This article reviews the main research strategies that have been used to study the genetics of LDD, and the genes that thus far have been identified to influence susceptibility to LDD. With the rapid progress in genomic technologies, further advances in the genetics of LDD are expected in the next few years. © 2011 Elsevier Inc.postprin