Stefanus Renaldi Wijaya, Augusto Martins, Katie Morris
et al.
The detection of low-molecular-weight biomarkers is essential for diagnosing and managing various diseases, including neurodegenerative conditions such as Alzheimer’s disease. A biomarker’s low molecular weight is a challenge for label-free optical modalities, as the phase change they detect is directly proportional to the mass bound on the sensor’s surface. To address this challenge, we used a resonant Young’s slit interferometer geometry and implemented several innovations, such as phase noise matching and optimisation of the fringe spacing, to maximise the signal-to-noise ratio. As a result, we achieved a limit of detection of 2.9 × 10<sup>−6</sup> refractive index units (RIU). We validated our sensor’s low molecular weight capability by demonstrating the detection of Aβ-42, a 4.5 kDa peptide indicative of Alzheimer’s disease, and reached the clinically relevant pg/mL regime. This system builds on the guided mode resonance modality we previously showed to be compatible with handheld operation using low-cost components. We expect this development will have far-reaching applications beyond Aβ-42 and become a workhorse tool for the label-free detection of low-molecular-weight biomarkers across a range of disease types.
The helmet shell material featuring a gradient in bending is urgently required for the next-generation integrated helmet system. However, achieving a bending gradient design for orthogonal woven composites on a 3D shell surface is a significant challenge. Here, nonorthogonal woven composites at 30°, 45°, and 60° were fabricated, and their bending properties are discussed. Furthermore, their bending properties are compared to those of plain off-axis woven composites, which indicates that the bending linearity trend of nonorthogonal woven composites is evident. Notably, the bending strength of the 30° and 60° nonorthogonal woven composites is 66.9 and 67.4% higher, respectively, than that of the plain off-axis woven composites, and the bending modulus is 169.8 and 196.9% higher, respectively. Finally, a finite element analysis of the bending properties of nonorthogonal woven composites was conducted, and a stress analysis of the inner layers was also conducted. This work paves the way for designing gradient materials for helmet shells.
Operation mode is widely used in a refinery production process, bringing great convenience to its daily operations. However, the refinery scheduling model with operation mode makes the scheduling model become large and thus difficult to solve. In this article, we present a new refinery scheduling model based on Variable Driven Modelling (VDM) approach. The proposed model is with less variables, less constraints, and less branching nodes compared with the existing works. Furthermore, VDM builds model from a novel aspect of variable (i.e. variable-based), while the traditional method building model from rule aspect (i.e. rule-based). The model built by VDM has a more stable form and better readability, and is beneficial for building a widely applicable and standard refinery scheduling model. The results of numerical experiments show computational advantages of the proposed model.
HOU Dali, HAN Xin, TANG Hongming, GUO Jianchun, GONG Fengming, SUN Lei, QIANG Xianyu
Adsorbed gas represents a primary mode of shale gas occurrence and is a major source of shale gas production in the later stages of development. It primarily resides within the organic kerogen and clay minerals of shale formations, with organic kerogen being the dominant host. Consequently, the study of organic kerogen characteristics and its adsorption mechanisms is crucial for understanding shale gas development. In this paper, the kerogen of Longmaxi Shale in the Sichuan Basin is taken as the research object. The microstructure of kerogen is expressed by combining methods through the solid-state NMR experiment, Fourier transform infrared spectroscopy experiment, X-ray photoelectron spectroscopy experiment, and the molecular structure model of kerogen is constructed. The adsorption mechanism and characteristics of CH4 in kerogen of Longmaxi Shale are analyzed by magnetic levitation weight experiment, molecular simulation methods of the Grand Canonical Monte Carlo（GCMC）, and Molecular Dynamics（MD）. The results show that the molecular formula of the kerogen of shale experimental sample of Longmaxi Formation is C237H219O21N5S4. The excess adsorption gas volume of CH4 in kerogen increase first and then decreased with the increase of pressure. Under the same pore size and pressure, the excess adsorption gas volume and total gas volume of CH4 decrease with the increase in temperature. The C and S atoms in kerogen are the main cause of CH4 adsorption. The CH4 near the kerogen pore wall presents an adsorption state, while the CH4 far from the kerogen pore wall presents a free state. As the pore size increase, the distance between the two peaks of CH4 density gradually increases, and the peak value decreases gradually.
Petroleum refining. Petroleum products, Gas industry
Ion-sensitive field-effect transistors (ISFETs) are used as elementary devices to build many types of chemical sensors and biosensors. Organic thin-film transistor (OTFT) ISFETs use either small molecules or polymers as semiconductors together with an additive manufacturing process of much lower cost than standard silicon sensors and have the additional advantage of being environmentally friendly. OTFT ISFETs’ drawbacks include limited sensitivity and higher variability. In this paper, we propose a novel design technique for integrating extended-gate OTFT ISFETs (OTFT EG-ISFETs) together with dual-gate OTFT multiplexers (MUXs) made in the same process. The achieved results show that our OTFT ISFET sensors are of the state of the art of the literature. Our microsystem architecture enables switching between the different ISFETs implemented in the chip. In the case of sensors with the same gain, we have a fault-tolerant architecture since we are able to replace the faulty sensor with a fault-free one on the chip. For a chip including sensors with different gains, an external processor can select the sensor with the required sensitivity.
<b>Objective:</b> This study aimed to improve the utilization value of scallop processing by-products, by analyzing the antioxidant activity of its protein hydrolysates. <b>Methods:</b> The processing by-products of <i>Argopecten irradians</i> were used as raw materials, and the proteins were extracted by alkali extraction and acid precipitation, alkali extraction and ammonium sulfate precipitation and low temperature ethanol denaturation precipitation. Then the proteins were analyzed by SDS-PAGE. Pepsin, flavourzyme, dispase and alcalase were used to hydrolyze the protein, and the antioxidant activities of the hydrolysate products were analyzed. The molecular weight distribution, amino acid composition and hydroxyproline content of dispase hydrolysates were further analyzed. <b>Results:</b> The purity of protein obtained by alkaline ammonium sulfate precipitation method was the highest, reaching 91.16%, with the optima electrophoretic results. All the four hydrolysates had DPPH, ABTS, hydroxyl radical scavenging ability and reducing ability, and the dispase hydrolysate showed the highest antioxidant ability, especially hydroxyl radical scavenging rate, which reached （77.24±1.87）%. The hydrolysate of dispase contained 15 kinds of amino acids such as aspartic acid, with a total content of 84 g/100 g, and the content of hydroxyproline reached （11.82±0.09）%. <b>Conclusion:</b> The protein obtained from the by-products of scallop processing by alkaline extraction and ammonium sulfate precipitation, and its dispase hydrolysates have optimal antioxidant activity and high nutritional value, which can be further developed as antioxidant functional food.
Petros Petrounias, Panagiota P. Giannakopoulou, Aikaterini Rogkala
et al.
This study was based on the reduction of the extraction of natural resources and, at the same time, was focused on the use of by-products and various wastes in construction applications by following the principles of circular economy. Sterile natural rocks (limestones, basalts), industrial by-products (slags), hotel construction wastes (bathroom wastes) and electronic wastes (e-wastes) were tested for pervious concrete aggregates. For this reason, ten concrete specimens were prepared and tested petrographically, structurally, and physically. The physical properties of the tested raw materials directly depended on their petrographic characteristics and played crucial role for the permeability of the produced concrete specimens, for their mechanical behavior, and for the freeze–thaw test results. Generally, from this study, strong encouraging results were achieved as concrete made by variable wastes and by-products can be compatible for concrete production as they show similar performance both in the mechanical strength test and in the freeze–thaw test with those made by natural aggregates. Another goal of this study was to recommend to other researchers the extended use of by-products, construction wastes, and e-wastes as concrete aggregates for producing eco-friendly constructions.
Abolfazl Jahangiri, Parviz Owlia, Iraj Rasooli
et al.
Abstract Acinetobacter baumannii is a serious health threat with a high mortality rate. We have already reported prophylactic effects of IgYs raised against OmpA and Omp34 as well as against inactivated whole-cell (IWC) of A. baumannii in a murine pneumonia model. However, the infection was exacerbated in the mice group that received IgYs raised against the combination of OmpA and Omp34. The current study was conducted to propose reasons for the observed antibody-dependent enhancement (ADE) in addition to the therapeutic effect of specific IgYs in the murine pneumonia model. This phenomenon was hypothetically attributed to topologically inaccessible similar epitopes of OmpA and Omp34 sharing similarity with peptides of mice proteins. In silico analyses revealed that some inaccessible peptides of OmpA shared similarity with peptides of Omp34 and Mus musculus. Specific anti-OmpA and anti-Omp34 IgYs cross-reacted with Omp34 and OmpA respectively. Specific IgYs showed different protectivity against A. baumannii AbI101 in the murine pneumonia model. IgYs triggered against OmpA or IWC of A. baumannii were the most protective antibodies. IgY triggered against Omp34 is ranked next after those against OmpA. The lowest protection was observed in mice received IgYs raised against the combination of rOmpA and rOmp34. In conclusion, specific IgYs against OmpA, Omp34, and IWC of A. baumannii could serve as novel biotherapeutics against A. baumannii pneumonia.
One of the main concerns regarding medical imaging is the danger tissue’s ionizing due to the applied radiation. Many medical procedures are based on this ionizing radiation (such as X-rays and Gamma radiation). This radiation allows the physician to perform diagnosis inside the human body. Still, the main concern is stochastic effects to the DNA, particularly the cause of cancer. The radiation dose endangers not only the patient but also the medical staff, who might be close to the patient and be exposed to this dangerous radiation in a daily manner. This paper presents a novel concept of radiation reduced Computed Tomography (CT) scans. The proposed concept includes two main methods: minification to enhance the energy concertation per pixel and subpixel resolution enhancement, using shifted images, to preserve resolution. The proposed process uses several pinhole masks as the base of the imaging modality. The proposed concept was validated numerically and experimentally and has demonstrated the capability of reducing the radiation efficiency by factor 4, being highly significant to the world of radiology and CT scans. This dose reduction allows a safer imaging process for the patient and the medical staff. This method simplifies the system and improves the obtained image quality. The proposed method can contribute additively to standard existing dose reduction or super-resolution techniques to achieve even better performance.
Ignacio Rubio, Antonio Díaz-Álvarez, Richard Bernier
et al.
This work focuses on the combination of two complementary non-destructive techniques to analyse the final deformation and internal damage induced in aramid composite plates subjected to ballistic impact. The first analysis device, a 3D scanner, allows digitalising the surface of the tested specimen. Comparing with the initial geometry, the permanent residual deformation (PBFD) can be obtained according to the impact characteristics. This is a significant parameter in armours and shielding design. The second inspection technique is based on computed tomography (CT). It allows analysing the internal state of the impacted sample, being able to detect possible delamination and fibre failure through the specimen thickness. The proposed methodology has been validated with two projectile geometries at different impact velocities, being the reaction force history on the specimen determined with piezoelectric sensors. Different loading states and induced damages were observed according to the projectile type and impact velocity. In order to validate the use of the 3D scanner, a correlation between impact velocity and damage induced in terms of permanent back face deformation has been realised for both projectiles studied. In addition, a comparison of the results obtained through this measurement method and those obtained in similar works, has been performed in the same range of impact energy. The results showed that CT is needed to analyse the internal damage of the aramid sample; however, this is a highly expensive and time-consuming method. The use of 3D scanner and piezoelectric sensors is perfectly complementary with CT and could be relevant to develop numerical models or design armours.
The main objective of this work was primary screening and isolation of lipase-producing microorganisms from oil-mill waste. For the screening of fungal strains with lipolytic activity, we employed a sensitive agar plate method, using a medium supplemented with CaCl2 and Tween 80. Another Tributyrin lipase activity was detected from clearing zones due to the hydrolysis of the triacylglycerols. The evolution of biomass and enzyme production has been assayed. A quantitative analysis of lipase activity was performed by the titration method using olive oil as a substrate supplemented with glucose or Tween 80. We have isolated some lipolytic strains from oil-mill effluent. Three of them were found to be excellent lipase producers that were identified as Penicillium sp, Aspergillus fumigatus and Aspergillus terreus. Lipolytic activity and biomass were enhanced in the medium supplemented by glucose. Tween 80 is also considered as a best inducer at the concentration of 1 %. In this condition, these isolates showed maximum lipase production within 24 h; achieved (3.91 IU‧mL-1 ± 0.12) for Penicillium sp.
Poly vinylidene chloride-vinyl chloride emulsions (PVDC) were added as a substitute for chlorinated paraffin (CP) in the preparation of ultra-low density fiberboards (ULDFs). The micromorphology and fire performance of ULDFs were investigated using a scanning electron microscope, limiting oxygen index instrument, and cone calorimeter. The results showed that PVDC specimens were coated with a regularly smooth film, while the distribution of CP inside CP specimens was uneven. The limiting oxygen index increased with the dosage of PVDC, then reached a plateau at 50 mL and 28%, slightly higher than CP specimens (27.3%). The peak of heat release rate, mean heat release rate, mean CO, and total smoke release of PVDC specimens was reduced 43.3%, 13.5%, 38.5%, and 51.5% lower than respective CP specimens, and with nearly the same total heat release (only 0.04 MJ/m2 higher). Thus, PVDC exhibited excellent heat-reducing and smoke-suppressing properties and could replace CP in ULDFs.
Abdo M. Al-Fakih, Madzlan Aziz, Hassan H. Abdallah
et al.
The inhibition of mild steel corrosion in 1 M HCl by 17 furan derivatives was investigated experimentally using potentiodynamic polarization measurements. The furan derivatives inhibit the mild steel corrosion. The experimental inhibition efficiency (IE) was used in a Quantitative Structure-Activity Relationship (QSAR) study. Dragon software was used to calculate the molecular descriptors. Penalized multiple linear regression (PMLR) was applied as a variable selection method using three penalties namely, ridge, LASSO, and elastic net. A number of 8 and 38 significant molecular descriptors were selected by LASSO and elastic net methods, respectively. The most significant descriptors namely, PJI3, P_VSA_s_4, Mor16u, MATS3p, and PDI were selected by both LASSO and elastic net methods. The elastic net results show low mean-squared error of the training set (MSEtrain) of 0.0004 and test set (MSEtest) of 5.332. The results confirm that the penalized multiple linear regression based on elastic net penalty is the most effective method to deal with high dimensional data.
Industrial electrochemistry, Physical and theoretical chemistry
In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS), which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.
Disposable screen-printed nickel/carbon composites on indium tin oxide (ITO) electrodes (DSPNCE) were developed for the detection of glucose without enzymes. The DSPNCE were prepared by screen-printing the ITO substrate with a 50 wt% nickel/carbon composite, followed by curing at 400 °C for 30 min. The redox couple of Ni(OH)2/NiOOH was deposited on the surface of the electrodes via cyclic voltammetry (CV), scanning from 0–1.5 V for 30 cycles in 0.1 M NaOH solution. The DSPNCE were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The resulting electrical currents, measured by CV and chronoamperometry at 0.65 V vs. Ag/AgCl, showed a good linear response with glucose concentrations from 1.0–10 mM. Also, the prepared electrodes showed no interference from common physiologic interferents such as uric acid (UA) or ascorbic acid (AA). Therefore, this approach allowed the development of a simple, disposable glucose biosensor.
Basic materials for the dental and orthopaedic implants production are commercially pure titanium and titanium alloys. Currently, the different methods of the metallic-surface treatments are developed for the purpose of their biocompatible-properties improvement and acceleration of the healing process of titanium implants. These methods are based on the morphological or biochemical modification of physical, chemical and mechanical properties, in particular, changes of surface energy, surface charge, chemical composition, and surface topography. Lately, there is a new prospective area related to the use of laser technology for treatment of the metallic materials for the purpose of improvement of biocompatible, tribology and corrosive characteristics of metallic-implants surface. By such a technology, it is possible to solve a problem of the surface-properties complex modification, in particular, for titanium implants. In a given review, the analysis of works dealing with the researches of an influence of the laser treatment of titanium-implants surface with regard to different aspects of the biocompatibility problem (for in vitro and in vivo experiments) is carried out. The goal of this review is an acquaintance of readers with some works of the last years undertaken by foreign authors in area of the laser-assisted modification of a structure, physicochemical and physical-mechanical properties of a surface of titanium implants as well as researches of both their influence on the behaviour of cell cultures and their interplays with bone tissues. An offered review does not claim to be exhaustive analysis of all known publications in this area. The primary aim of this review lies in demonstration of the most successful areas of the laser-radiation application for increase of the biocompatible-properties complex of titanium implants.
Jasna Mrvčić, Tatjana Prebeg, Lidija Barišić
et al.
Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB) has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h). FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.