Arthroscopic Resection of Humeral Enchondroma

Enchondromas are common benign bone tumors. They are often found incidentally and usually do not require any treatment other than clinical surveillance. Signs of lesion progression or nontolerable pain are criteria for surgical resection. We present a case of a 44-year-old woman with long-lasting shoulder pain, diagnosed with enchondroma. Imaging studies showed an enchondroma near the great tuberosity. Shoulder arthroscopy made it possible to diagnose and treat an SLAP lesion as well as to resect by curettage and shaving through the subacromial lateral portal. One year after surgery, the patient had significant pain relief and improved shoulder function. Shoulder arthroscopy seems to be a safe and suitable technique for resection of small-sized humeral enchondromas, with the advantage of allowing to treat other possible concomitant shoulder pathologies.

Study of open versus closed reduction of mandibular condyle fractures

Background: Condylar fractures of the mandible are a commonest occurrence in maxillofacial surgery. Many surgeons prefer closed therapy with maxillomandibular fixation, while open treatment with rigid internal fixation has become more common in recent years. This study provides a comparative evaluation of open and closed reduction of the mandibular condyle.Methods: The 50 patients with condylar fractures were treated with open and closed reduction as per the requirement.Results: A higher incidence of unilateral segmented condylar fractures were seen in young adult males. Open reduction and internal fixation (ORIF) with a combined approach was the preferred treatment of choice with fewer post-op complications.Conclusions: ORIF is a suitable technique in the treatment of condylar fractures as it promises few complications.

Photocatalytic Inactivation of Salmonella typhimurium by Floating Carbon-Doped TiO2 Photocatalyst

Photocatalysis application is considered as one of the most highly promising techniques for the reduction in wastewater pollution. However, the majority of highly efficient photocatalyst materials are obtained as fine powders, and this causes a lot of photocatalyst handling and reusability issues. The concept of the floating catalyst proposes the immobilization of a photocatalytic (nano)material on relatively large floating substrates and is considered as an encouraging way to overcome some of the most challenging photocatalysis issues. The purpose of this study is to examine floating photocatalyst application for Salmonella typhimurium bacteria inactivation in polluted water. More specifically, high-density polyethylene (HDPE) beads were used as a photocatalyst support for the immobilization of carbon-doped TiO2 films forming floating photocatalyst structures. Carbon-doped TiO2 films in both amorphous and anatase forms were deposited on HDPE beads using the low-temperature magnetron sputtering technique. Bacteria inactivation, together with cycling experiments, revealed promising results by decomposing more than 95% of Salmonella typhimurium bacteria in five consecutive treatment cycles. Additionally, a thorough analysis of the deposited carbon-doped TiO2 film was performed including morphology, elemental composition and mapping, structure, and depth profiling. The results demonstrate that the proposed method is a suitable technique for the formation of high-quality photocatalytic active films on thermal-sensitive substrates.

Infrared thermography analysis with a low-cost camera in plaster sculptures of museum collections

Infrared thermography (IRT) is a non-destructive and non-invasive technique that provides the possibility to investigate the surface of sculptures for the detection of subsurface features and anomalies such as delamination, layer structure, fillings, and defects. IRT has been widely used in buildings and large structures, as well as in works of art such as bronze sculptures and paintings. This article describes the application of active infrared thermography, using a portable low-cost IRT camera, in the examination of plaster sculptures, a material where it has not yet been applied to. In particular, it was used in two plaster sculptures by 19th-century Portuguese artist Soares dos Reis, within a wider project (GEO-SR) aimed at the study of his work. The results indicate that thermography is a suitable technique with a great potential to detect alterations under the surface of plaster, revealing a new look into its manufacturing and conservation.

High efficiency Doherty power amplifiers for modern wireless communication systems: A brief review

Due<span lang="EN-MY">to the high peak to average power ratio (PAPR) of modern modulated signals, power amplifiers (PAs) have been forced to operate at the back-off (BO) region of their saturation power in order to avoid signal clipping and distortion. However, classical PAs suffer from low efficiency in the BO region operation. Therefore, efficiency has to be enhanced in that region. Many techniques have been proposed. Among them, the Doherty power amplifier (DPA) is considered as the most suitable technique due to its simple structure and high performance. However, its conventional design is limited to a 6 dB BO level, which does not satisfy the requirements of modern communication systems. In this paper, a brief review of the most significant techniques of high-efficiency DPA is presented. First, DPA topology and its operation principles are briefly discussed. Second, efficiency enhancement techniques such as an asymmetrical DPA, output combiner modification, gate bias adaption, offset line optimization, and multi-way DPA were discussed. The study shows that the most suitable, simple, and effective solution is an asymmetrical approach. However, it needs to be investigated in terms of bandwidth in order to meet the efficiency-bandwidth requirements of modern wireless communication systems such as </span>5G.

Ecological Responses of Macroinvertebrates to an In-Stream Ecosystem Restoration Technique in a Tropical Stream in Eastern Uganda

A field experiment was conducted to examine the ecological responses of macroinvertebrates to an in-stream ecosystem restoration technique called woody debris introduced in a stream in different arrangements to show how they (woody debris) affected the macroinvertebrate ecology, specifically assemblage composition and biometrics in River Nabongo. The experiment was carried out in two heterogeneous stream environments i.e., i) in a riffle found in the middle reaches of the river at a higher altitude and ii) a pool in the lower altitude and reaches of the river. Each of these two treatments had a control plot for comparison purposes. Four macroinvertebrate sampling campaigns were launched in experimental sites from September 2019 to April 2021. All restoration structures had more macroinvertebrates than control and pre-treatment sites. The introduction of simple structures at the riffle site led to an increase in collector-filterers from 9-128 individuals, while at the pool site all the structures increased macroinvertebrates by 1151 individuals. Taxon richness was highest in the complex plot with 14±0.41 which significantly differed from the rest of the sampling plots at P<0.05. The relative abundance of taxa at the pool site varied significantly from one sampling plot to another at P<0.05 with the highest mean abundance registered in complex and simple structures having 61.3±0.10 and 23.5±0.11 respectively. It was concluded that complex woody debris structures increase the diversity, abundance and richness of aquatic macroinvertebrates by providing hard substrates for colonization by algae and microorganisms on which macroinvertebrates feed. We recommended that other researchers should study the impact of other in-stream ecosystem restoration techniques such as floating islands, constructed wetlands, D-deflectors, a comparison of which with restored woody debris will enable ecologists to choose the most suitable technique to apply at different stream points.

Separation of carvone by batch distillation from the mixture obtained from limonene oxidation

Limonene is the main constituent of citrus oils whose oxidation produces a set of fine chemical compounds such as carvone, carveol, and limonene 1,2-epoxide. This contribution reports the results of the experimental evaluation and computational simulation of carvone separation by fractional distillation from the reaction mixture. Carvone was obtained from limonene oxidation over a perchlorinated iron phthalocyanine supported on modified silica catalyst (FePcCl16-NH2-SiO2) and t-butyl hydroperoxide (TBHP) as oxidant. Both experimental and simulation results support that fractional distillation (in batch and continuous) is a suitable technique for concentrating carvone. However, in the presence of water, the formation of immiscible L-L phases makes the experimental separation of carvone more difficult. Simulation results of the batch distillation incorporating the NRTL-RK thermodynamic model indicate that if water, acetone, and t-butanol are previously removed from the reaction mixture, carvone composition can be enriched in the reboiler from 4% up to 50%, or around 86.5% if the removal is in a third distillate cut under vacuum conditions.

Comparative Study of Three Vitrification Solutions for an Effective Droplet-vitrification Cryopreservation Procedure for Pfaffia Glomerata (Spreng.) Pedersen

Aims: The objective of this research was to establish a cryopreservation protocol for shoot tips (ST) of in vitro P. glomerata using the droplet-vitrification technique. Study Design: The experimental design was a factorial, with four factors, arranged in a completely randomized design. Three vitrification solutions (PVS2, PVS3, PVS4), three times (20, 40, 60 min) and two temperatures (25 ± 2 °C and 0 °C) of treatment with the solutions, followed by freezing (LN+) or not (LN-) with liquid nitrogen (LN) were tested. All tests were performed using six replicates and the results analysed using Two-way ANOVA and Tukey’s tests and expressed as the mean ± the standard error of the means (SEM) deviation. Place and Duration of Study: Laboratory of Plant Cryobiology, Embrapa Genetic Resources and Biotechnology, over a two-year period. Methodology: ST excised from in vitro plantlets were pre-cultured overnight (19h), treated with a loading solution (LS) and three different vitrification solutions (PVS2, PVS3, PVS4) prior to freezing in LN. Treatment with the vitrification solutions was carried out at 0 or 25°C, for 20, 40 or 60 min. For freezing, drops of the vitrification solutions containing a single ST were dispensed on aluminum foil strips and the strips were submerged in LN (-196°C). For thawing, foil strips were submerged into unloading solution (US) at 40 ± 2°C, for three min. Thawed ST were transferred to regeneration medium and cultured in vitro. Results: Highest regeneration percentages after cryopreservation were 82% for ST treated with PVS3, at 0°C, for 60 min; 32% for ST treated with PVS4 at 25°C for 60 min or 0°C for 40 min and 22% for those treated with PVS2 at 0°C for 60 min. Conclusion: Droplet-vitrification is a suitable technique to ensure survival of P. glomerata ST after cryopreservation. This procedure can be applied to establish germplasm collections of this medicinal species in gene banks.

Application of Empty Oil Palm Bunches as CMC to Prevent Loss Circulation

Drilling is an activity carried out to obtain the desired target. Furthermore, drilling mud a very significant material involved in the drilling process, and must, therefore, obtain a rational value from the rheology. A suitable technique to achieve this goal is the use of additives, for instance, Carboxymethyl Cellulose (CMC) to improve the viscosity and air binding. This study, therefore, uses CMC produced from organic oil palm bunches as an alternative for industrial CMC. CMC of Oil Palm Empty Bunches have been tested by Energy Dispersive X-ray Spectroscopy (EDS) to determine its composition. The Empty Oil Palm Oil which uses Tenera type was taken from Riau Province, Rokan Hulu Regency, Kunto Darussalam District. In this study, this experiment used CMC Empty Oil Palm and industrial CMC to find the value of viscosity, plastic thickness, melting point, gel strength, mud cake, and filtering volume of drilling mud and prevent the loss circulation with adding each CMC composition to mud samples with amount of 2 gr, 4 gr, 6 gr, 8 gr and 10 gr. According to the EDS analysis, the Carbon (C) and Oxygen (O) content of CMC from empty oil palm bunches were 58.85% and 41.15%, respectively. In addition, the industrial standard for plastic viscosity and yield point were not attained by using 8 gr and 10 gr of this CMC.