Comments on 'Increasing film-focus distance (FFD) reduces radiation dose for X-ray examinations' by P.C. Brennan, S. McDonnell and D. O'Leary

Sir, Comments on ‘Increasing film-focus distance (FFD) reducesradiation dose for X-ray examinations’ by P.C. Brennan,S. McDonnell and D. O'Leary. In a recent publication, Brennan et al.⁽¹⁾ claim that increasingthe film-focus distance (FFD) from 100 to 130 cm will reduceeffective doses (E) by 33% for a pelvic X-ray examination. Thisconclusion is based on a reported 33% reduction in the entrancesurface dose (ESD), by the use of the same effective dose perunit ESD conversion coefficient (E/ESD) at both FFD values.However, E/ESD values are only valid for the specific     

Effective Noise Reduction by Electric Positive and Negative Feedback in Semiconductor Lasers

Semiconductor lasers tend to generate excess intensity noise called the optical feedback noise in addition to the quantum noise. A noise reduction method using an electric positive and negative feedback loop between an optical detector and a semiconductor laser was demonstrated in this paper. The electric positive feedback was set in a high-frequency region, reducing the optical feedback noise, while the electric negative feedback was set in a frequency range lower than the positive-feedback frequency, resulting in the suppression of the quantum noise (optical shot noise). Noise reduction over 100-MHz frequency region and a reduction ability superior to that obtained by the superposition of high-frequency current were confirmed.     

Nonmeat Protein Alternatives as Meat Extenders and Meat Analogs

Abstract: The direct consumption of vegetable proteins in food products has been increasing over the years because of animal diseases, global shortage of animal protein, strong demand for wholesome and religious (halal) food, and economic reasons. The increasing importance of legume and oilseed proteins in the manufacturing of various functional food products is due to their high‐protein contents. However, the greatest obstacle to utilizing these legumes and oilseeds is the presence of antinutrients; but these antinutrients can be successfully removed or inactivated by employing certain processing methods. In contrast, the potential negative impact of the antinutrients is partially balanced by the fact that they may have a health‐promoting role. Legumes and oilseeds provide well‐balanced amino acid profiles when consumed with cereals. Soybean proteins, wheat gluten, cottonseed proteins, and other plant proteins have been used for texturization. Texturized vegetable proteins can extend meat products while providing an economical, functional, and high‐protein food ingredient or can be consumed directly as a meat analog. Meat analogs are successful because of their healthy image (cholesterol free), meat‐like texture, and low cost. Mycoprotein is fungal in origin and is used as a high‐protein, low‐fat, health‐promoting food ingredient. Mycoprotein has a good taste and texture. Texturized vegetable proteins and a number of mycoprotein products are accepted as halal foods. This article summarizes information regarding the molecular, nutritional, and functional properties of alternative protein sources to meat and presents current knowledge to encourage further research to optimize the beneficial effects of alternative protein sources.     

The Tuna Fishing Industry: A New Outlook on Fish Protein Hydrolysates

Abstract: Tuna (Thunnus spp.) and tuna‐like species are significant sources of food and thus play a very important role in the economy of many countries. More than 48 species of tuna swarm the Atlantic, Indian, and Pacific Oceans, and the Mediterranean Sea. The annual global production of tuna has undergone a marked increase from less than 0.6 million metric tons in 1950 to almost 4.5 million metric tons in 2007. Tuna generally is processed as raw fish flesh and marketed as loins/steaks or as a canned food. In the tuna canning process, only about one‐third of the whole fish is used. Thus, the canning industry generates as much as 70% solid wastes from original fish materials. This waste consists of muscle (after loins are taken), viscera, gills, dark flesh/muscle, head, bone, and skin. Conventionally, these protein‐rich by‐products from the tuna industry are processed into low market value products, such as fish meal and fertilizer. However, a promising alternative use of these by‐products is as functional food ingredients. Fish protein hydrolysate (FPH), which is obtained through hydrolysis of tuna waste, can be used as an ingredient in food industries to provide functional effects such as whipping, gelling, and texturing properties. Recently, FPH was found to be a potential source of antioxidants (such as peptides with anticancer properties), antianemia compounds, and components for use in microbial growth media. This article is intended to summarize the existing knowledge about FPH, highlight some pertinent information related to the tuna fishing industry, and provide a new outlook on the production and applications of FPH.     

Ethanolic Noni (Morinda citrifolia L.) leaf extract dechlorophyllised using sedimentation process: Antioxidant,antibacterial properties and efficacy in extending the shelf-life of striped catfish slices

Antioxidant and antimicrobial activities of ethanolic noni leaf extract (ENLE) without and with chlorophyll removal by sedimentation method were comparatively investigated. Total chlorophyll content was reduced by 82% in the top fraction (CR-ENLE) collected after 24 h at 4 °C as compared to that of ENLE. Antioxidant and antimicrobial activities were lower in the bottom fraction rich in chlorophyll (Chlo-ENLE) than others (P < 0.05). Based on the microbiological limit, the shelf-life of striped catfish slices pre-treated with 400 mg kg⁻¹ C-R-ENLE was extended to 9 days as compared to the 3 days recorded for the control (without pre-treatment). Slices treated with CR-ENLE had lower lipid oxidation than those treated with ENLE during refrigerated storage (P < 0.05). The sedimentation process was therefore a potential green method for producing ENLE having improved antioxidant and antimicrobial activities without green colour. It can be used as a natural additive for shelf-life extension of fish slices.     

A robust digital audio watermarking scheme based on DWT and Schur decomposition

The vulnerability of digital audio signals for different types of risks requires an imperceptible and robust digital audio watermarking scheme. In this research, we propose creating one such imperceptible and robust hybrid watermarking scheme based on a discrete wavelet transform (DWT) and Schur decomposition hybrid method. The proposed scheme embeds the foreground bits of the watermarking image into the least significant bit of the diagonal coefficients of the triangular matrix S generated from Schur decomposition. Schur decomposition is applied on the second sub-band HL₂ generated from applying a second-level 2D-Haar DWT on the first channel of the original audio signal. We analyze the proposed digital audio watermarking scheme’s performance in terms of signal to noise ratio (SNR), objective difference grades (ODG), and subjective difference grades (SDG) that resulting 81.43, 4.78 and 0.184, respectively. The resulting of payload capacity, NC, and BER are as high as 319.29 bps, 0.9911, and 0.0135, respectively. Experimental results confirm that the proposed scheme is inaudible and robust against common types of attacks such as Gaussian noise, re-quantization, re-sampling, low-pass filter, high-pass filter, echo, MP3 compression, and cropping. In comparison with state-of-the-art audio watermarking schemes, the proposed scheme’s performance is superior in term of imperceptibility, robustness, and data payload size.

     

Enhancement of Infrared Images Using Super Resolution Techniques Based on Big Data Processing

This paper presents a super-resolution (SR) technique for enhancement of infrared (IR) images. The suggested technique relies on the image acquisition model, which benefits from the sparse representations of low-resolution (LR) and high-resolution (HR) patches of the IR images. It uses bicubic interpolation and minimum mean square error (MMSE) estimation in the prediction of the HR image with a scheme that can be interpreted as a feed-forward neural network. The suggested algorithm to overcome the problem of having only LR images due to hardware limitations is represented with a big data processing model. The performance of the suggested technique is compared with that of the standard regularized image interpolation technique as well as an adaptive block-by-block least-squares (LS) interpolation technique from the peak signal-to-noise ratio (PSNR) perspective. Numerical results reveal the superiority of the proposed SR technique.

     

Correlation between Oxidative Stress and Transforming Growth Factor-Beta in Cancers

The downregulation of reactive oxygen species (ROS) facilitates precancerous tumor development, even though increasing the level of ROS can promote metastasis. The transforming growth factor-beta (TGF-β) signaling pathway plays an anti-tumorigenic role in the initial stages of cancer development but a pro-tumorigenic role in later stages that fosters cancer metastasis. TGF-β can regulate the production of ROS unambiguously or downregulate antioxidant systems. ROS can influence TGF-β signaling by enhancing its expression and activation. Thus, TGF-β signaling and ROS might significantly coordinate cellular processes that cancer cells employ to expedite their malignancy. In cancer cells, interplay between oxidative stress and TGF-β is critical for tumorigenesis and cancer progression. Thus, both TGF-β and ROS can develop a robust relationship in cancer cells to augment their malignancy. This review focuses on the appropriate interpretation of this crosstalk between TGF-β and oxidative stress in cancer, exposing new potential approaches in cancer biology.     

Study of MA Effect on Yield Strength and Ductility of X80 Linepipe Steels Weld

Multipass GMAW (Gas Metal Arc Welding) welding was used to join X80 linepipe materials using two weld metals of slightly different compositions. Welding wires with diameters of 0.984 and 0.909 mm were used while applying the same heat input in each pass. The slight difference in the wire diameters resulted in different HAZ microstructures. The microstructures in the doubly reheated HAZ of both welds were found to contain bainite-ferrite. However, etching also revealed a difference in martensite-austenite (MA) fraction in these reheated zones. The MA exhibited twice the hardness of ferrite when measured by nanoindentation. Tensile testing from the reheated zone of both welds revealed a difference in yield strength, tensile strength and elongation of the transverse weld specimens. In the reheated zone of weld A, (produced with a 0.984 mm wire) a higher fraction of MA was observed, which resulted in higher strength but lower elongation compared to weld B. The ductility of weld A was found severely impaired (to nearly half of weld B) due to formation of closely spaced voids around the MA, along with debonding of MA from the matrix, which occurs just above the yield stress.

     

Thiobarbiturates as sirtuin inhibitors: virtual screening, free-energy calculations, and biological testing

NAD+-dependent histone deacetylases (sirtuins) are enzymes that cleave acetyl groups from lysine residues in histones and other proteins. Potent selective sirtuin inhibitors are interesting tools for the investigation of the biological functions of these enzymes and may be future drugs for the treatment of cancer or neurodegenerative diseases. Herein we present the results from a protein-based virtual screen of a commercial database with subsequent biological testing of the most promising compounds. The combination of docking and in vitro experimental testing resulted in the identification of novel sirtuin inhibitors with thiobarbiturate structure. To rationalize the experimental results, free-energy calculations were carried out by molecular mechanics Poisson-Boltzmann/surface area (MM-PBSA) calculations. A significant correlation between calculated binding free energies and measured Sirt2 inhibitory activities was observed. The analyses suggested a molecular basis for the interaction of the identified thiobarbiturate derivatives with human Sirt2. Based on the docking and MM-PBSA calculations we synthesized and tested five further thiobarbiturates. The MM-PBSA method correctly predicted the activity of the novel thiobarbiturates. The identified compounds will be used to further explore the therapeutic potential of sirtuin inhibitors.