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Ion beam induced modification of thin metallic films is an emerging approach to grow metallic nanoparticles controllably. Modification of thin solid films is helpful in fabricating arrays of nanoscale particles for electronic and photonic devices and for the catalyzed synthesis of nanotubes and nanowires. In this work, the modification and nanostructures formation over the surface of SiC/Pd thin films of 15 and 45 nm thicknesses, grown on crystalline Silicon (c-Si) substrate by electron beam deposition, upon ion irradiation, have been investigated by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Rutherford backscattering spectrometry (RBS), Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. The SiC/Pd bilayer films were irradiated with 100 keV Ar+ ions at fluences of 1 × 1015 and 5 × 1015 ions/cm2 at room temperature. The surface morphology from SEM analysis showed the formation of nanoparticles that were interconnected after irradiation. The RBS and EDS results confirmed the presence of Pd, C, O and Si. While the Raman spectrum of the pristine sample displayed only a sharp peak at 520 cm−1 characteristic to c-Si substrate, the spectra of the irradiated sample red-shifted to lower wavenumbers indicating the appearance of Si nanocrystals.. Hence, ion beam irradiation is a promising method for the fabrication of SiC nanostructures on c-Si substrate. [ABSTRACT FROM AUTHOR]

Abstract Silicon (Si) has been the most widely used semiconductor for decades, playing an important role in the field of electronics, energy conversion and energy storage. Because of their unique morphological energy band characteristics, Si nanostructures exhibit superior performance in many applications in comparison with their bulk counterparts. In this study, the effects of thermal annealing on elemental composition and morphological properties of palladium metal thin films grown on c-Si substrates were investigated. Palladium (Pd) thin films of different thicknesses were deposited on Si (1 0 0) with and without native oxide layers by electron beam evaporation and annealed in vacuum at 600 °C for two hours. Scanning electron microscopy (SEM) studies have shown that the surface morphology showed an effective dewetting in individual droplets and islands which further coalesce into bigger islands. Rutherford backscattering spectrometry (RBS) and electrical measurements analyses revealed the diffusion of the Si substrate into the Pd layer during annealing. This contribution will discuss the effects of the metal layer thickness as well as the native oxide on the metal thin films. [ABSTRACT FROM AUTHOR]

The human papilloma virus has been shown to play a significant aetiological role in invasive cervical cancer. The changes caused by human papilloma virus can be evaluated using Pap smear. The discovery of Pap smears has led to an unprecedented dramatic decline in the incidence of cervical cancer over the past five decades. This has been the case in high income countries due to effective cervical cancer screening programmes. The effectiveness of this simple cost-effective tool has led to attempts at improving the quality of the Pap smear sample as well as the processing technique in the laboratory. This has led to the introduction of Liquid based cytology, a technique slowly replacing conventional cytology in the world due to its advantages. Although initially thought to be more sensitive and specific than conventional cytology, recent studies suggest that there are no significant differences in this aspect. The main advantage is that Liquid based cytology is less likely to be unsatisfactory or limited. Liquid based cytology has also reduced the screening time leading to improved turn-around time. The specimen submitted for liquid based cytology can be used to perform further tests such as molecular and microbiological studies. The Pap smear still plays an integral part in cervical cancer screening, despite recent advances in detection of human Papilloma virus using molecular techniques. The implementation of cervical screening programmes in low and middle income countries will assist in reducing the mortality related to invasive cervical cancer. [ABSTRACT FROM AUTHOR]

The choice of the short-term extender is important to preserve the quality of the diluted South African indigenous Kolbroek boar semen during short-term storage prior to artificial insemination. The aim of this study was to identify the suitable extender for short-term storage of Kolbroek boar semen at 17°C. Five ejaculates were collected separately from five Kolbroek boars using the gloved-hand technique in a 300-mL glass beaker. The filtered sperm fraction were sealed with a gauze filter inside a prewarmed (39°C) insulated thermos flask. Following semen collection, the semen was evaluated for macroscopic characteristics; semen volume, pH, and concentration. Sperm cells morphology was evaluated using eosin-nigrosin staining solution using fluorescent microscope system. Only ejaculates with >75% motile sperm and <15 abnormalities were used. The semen was pooled and diluted with five different short-term extenders, namely: Beltsville Thawing Solution (BTS), Kobidil+, Hungarian Standard, Citrate, and Tris-based extenders at a ratio of 1:1 (v/v). Sperm cells motility parameters were evaluated using a sperm class analyzer (SCA) at 0, 3, 24, and 48h intervals. The data were analysed by SPSS. The results demonstrated that sperm cell motility rate did not differ when stored at 0 (88.9±8.3) and 3 (93.8±4.4)h irrespective of extender. However, semen that was diluted with Hungarian extender and Tris-based extender maintained higher proportion of sperm cells motility (90.0±2.5 and 87.8±4.8, respectively) for a longer period during storage for 24h as compared with the other extenders. In conclusion, the study demonstrated that prolonged storage of boar sperm cells reduces motility rates. However; Hungarian Standard and Tris-based extenders preserved sperm motility rate better than the other extenders when stored up to 48h at 17°C. Thus, this study suggests that Kolbroek sperm cells can be transported within 24 to 48h in South African regions without adversely affecting motility rates when diluted with Hungarian Standard and Tris-based extender at 17°C without cryopreserving them. This study was funded by the Department of Agriculture Forestry and Fishery, ARC, DST (RT19000), and National Research Foundation (NRF, Grant. No. RT21 and 24000). [ABSTRACT FROM AUTHOR]

Background: Two drugs under consideration for inclusion in antiretroviral therapy (ART) regimens for human immunodeficiency virus (HIV) infection are dolutegravir (DTG) and tenofovir alafenamide fumarate (TAF). There are limited data on their use in low- and middle-income countries.Methods: We conducted a 96-week, phase 3, investigator-led, open-label, randomized trial in South Africa, in which we compared a triple-therapy combination of emtricitabine (FTC) and DTG plus either of two tenofovir prodrugs - TAF (TAF-based group) or tenofovir disoproxil fumarate (TDF) (TDF-based group) - against the local standard-of-care regimen of TDF-FTC-efavirenz (standard-care group). Inclusion criteria included an age of 12 years or older, no receipt of ART in the previous 6 months, a creatinine clearance of more than 60 ml per minute (>80 ml per minute in patients younger than 19 years of age), and an HIV type 1 (HIV-1) RNA level of 500 copies or more per milliliter. The primary end point was the percentage of patients with a 48-week HIV-1 RNA level of less than 50 copies per milliliter (as determined with the Snapshot algorithm from the Food and Drug Administration; noninferiority margin, -10 percentage points). We report the primary (48-week) efficacy and safety data.Results: A total of 1053 patients underwent randomization from February 2017 through May 2018. More than 99% of the patients were black, and 59% were female. The mean age was 32 years, and the mean CD4 count was 337 cells per cubic millimeter. At week 48, the percentage of patients with an HIV-1 RNA level of less than 50 copies per milliliter was 84% in the TAF-based group, 85% in the TDF-based group, and 79% in the standard-care group, findings that indicate that the DTG-containing regimens were noninferior to the standard-care regimen. The number of patients who discontinued the trial regimen was higher in the standard-care group than in the other two groups. In the per-protocol population, the standard-care regimen had equivalent potency to the other two regimens. The TAF-based regimen had less effect on bone density and renal function than the other regimens. Weight increase (both lean and fat mass) was greatest in the TAF-based group and among female patients (mean increase, 6.4 kg in the TAF-based group, 3.2 kg in the TDF-based group, and 1.7 kg in the standard-care group). No resistance to integrase inhibitors was identified in patients receiving the DTG-containing regimens.Conclusions: Treatment with DTG combined with either of two tenofovir prodrugs (TAF and TDF) showed noninferior efficacy to treatment with the standard-care regimen. There was significantly more weight gain with the DTG-containing regimens, especially in combination with TAF, than with the standard-care regimen. (ADVANCE ClinicalTrials.gov number, NCT03122262.). [ABSTRACT FROM AUTHOR]

A letter to the editor on tuberculous keratoconjunctivitis is presented.

Improving techniques for liquid storage of cock semen can increase the efficiency of AI programs in the poultry industry. The aims of the present study were (1) to compare storage of cock sperm for 24 h at 5 and 25°C and (2) to test the cryotolerance of sperm cell motility in individual Venda cocks. Semen was collected with the abdominal massage method, from 6 indigenous Venda cocks. Cocks were 26 weeks of age and were kept under the same conditions. After macroscopic analysis, semen was pooled and diluted (1:2) with Kobidil+ extender and divided into 3 equal parts. Part 1 was evaluated immediately (0 h), part 2 was stored at 5°C and part 3 was stored at 25°C and evaluated for sperm motility and velocity parameters at 4, 8, 12 and 24 h of storage. For cryopreservation, semen was diluted (1:2) with modified Kobidil+ extender supplemented with 8% of dimethyl sulfoxide. Individual ejaculates were equilibrated at 5°C for 4 h and then loaded into the programmable freezer. Then, semen straws were thawed at 5°C. Sperm motility and velocity parameters were evaluated using the Sperm Class Analyzer® system. Six replicates were done per trial. Data were analysed using the statistical programme GenStat®. Treatment means were separated using Fisher's protected t-test least significant difference (P < 0.05). Total sperm cell motility rate was 87.5% and decreased significantly during in vitro storage and was <31% after 24 h at 25°C. Semen samples stored at 5°C showed a total sperm cell motility rate of above 50% after 24 h. There was a slight linear decrease in the percentage of sperm with progressive motility and rapid velocity as the storage period increased, irrespective of the storage temperature. The rapid and medium motility percentages were higher in fresh semen and significantly decreased (P < 0.05) during the incubation period. There was variation in the total sperm cell motility of fresh and frozen semen among cocks. There was no significant difference in variation in non-progressive and medium percentage (P > 0.05) motility in diluted fresh or frozen sperm cells or in the percentage of sperm with rapid motility in thawed semen. There was variation in <25% of the cocks in total sperm motility rate. In summary, cryopreservation reduced sperm cell motility and velocity rates in all the cock semen donors. We found that cryotolerance of cock sperm does vary among males. Furthermore, the lower temperature 5°C was suitable for semen storage of Venda cocks. This temperature (5°C) could potentially improve methods of semen equilibration before cryopreservation. The study was supported by an Agricultural Research Council Parliamentary Grant, Department of Agriculture Forestry and Fisheries and National Research Foundation-GUN No RT21 and 24000 (NRF). The Germplasm Conservation & Reproduction Biotechnologies (GCRB) group is thanked for their support. [ABSTRACT FROM AUTHOR]