Hasil untuk "Chemical technology"

C. Zhou, X. Xia, C. Lin et al.

A. Luntz, B. McCloskey

A. Corma

V. Ashokkumar, R. Venkatkarthick, S. Jayashree et al.

Lignocellulosic biomass is a highly renewable, economical, and carbon-neutral feedstock containing sugar-rich moieties that can be processed to produce second-generation biofuels and bio-sourced compounds. However, due to their heterogeneous multi-scale structure, the lignocellulosic materials have major limitations to valorization and exhibit recalcitrance to saccharification or hydrolysis by enzymes. In this context, this review focuses on the latest methods available and state-of-the-art technologies in the pretreatment of lignocellulosic biomass, which aids the disintegration of the complex materials into monomeric units. In addition, this study also deals with the genetic engineering techniques to develop advanced strategies for fermentation processes or microbial cell factories to generate desired products in native or modified hosts. Further, this study also intends to bridge the gap in developing various economically feasible lignocellulosic products and chemicals using biorefining technologies.

E. Merisko-Liversidge, G. Liversidge, E. R. Cooper

M. Sastry, Absar Ahmad, M. I. Khan et al.

D. Dix, K. Houck, Matt T. Martin et al.

D. Spasiano, R. Marotta, S. Malato et al.

S. Dixit, A. Yadav, P. Dwivedi et al.

S. Rahimi, O. Modin, I. Mijakovic

Water contamination is a growing environmental issue. Several harmful effects on human health and the environment are attributed to nitrogen contamination of water sources. Consequently, many countries have strict regulations on nitrogen compound concentrations in wastewater effluents. Wastewater treatment is carried out using energy- and cost-intensive biological processes, which convert nitrogen compounds into innocuous dinitrogen gas. On the other hand, nitrogen is also an essential nutrient. Artificial fertilizers are produced by fixing dinitrogen gas from the atmosphere, in an energy-intensive chemical process. Ideally, we should be able to spend less energy and chemicals to remove nitrogen from wastewater and instead recover a fraction of it for use in fertilizers and similar applications. In this review, we present an overview of various technologies of biological nitrogen removal including nitrification, denitrification, anaerobic ammonium oxidation (anammox), as well as bioelectrochemical systems and microalgal growth for nitrogen recovery. We highlighted the nitrogen removal efficiency of these systems at different temperatures and operating conditions. The advantages, practical challenges, and potential for nitrogen recovery of different treatment methods are discussed.

K. S. Rajmohan, Ramyavardhanee Chandrasekaran, Sunita Varjani

Madison L. Dirks, Joseph Hale, Eric Theiste et al.

Glycomacropeptide (GMP) is isolated from whey and used as an ingredient in phenylketonuria-safe foods because it does not contain phenylalanine. GMP is highly glycosylated and has several sites where <i>N</i>-acetylneuraminic acid (NANA) is bound. In the dairy industry, quantification of NANA from dairy proteins is accomplished by colorimetric, fluorometric, enzymatic, and chromatographic procedures; there is no uniformly accepted industry-wide standard method. In this investigation, NANA quantification methods were evaluated using GMP, and a comparison was made based on the length of time to complete the assay, protein-specificity, linearity, precision, and accuracy. From the methods evaluated, the chromatography protocol was determined to have the greatest benefit for use as a dairy industry standard to measure NANA on GMP. The average mass percent of NANA in 10 statistically independent replicates from a commercial GMP product was measured to be 6.18% ± 0.12%, with a relative standard deviation of 1.94%, which was the lowest of all the methods tested. The accuracy of the chromatographic approach was validated using spike and recovery experiments that provided an average recovery of 90.25%.

Sylwia Stępniewska, Agnieszka Salamon, Grażyna Cacak-Pietrzak et al.

This study aimed to evaluate the use of oyster mushroom (<i>Pleurotus ostreatus</i>) powder (OMP) for producing rye bread. The raw materials were low-extract rye flour and OMP, which were analyzed in terms of their nutritional and health-promoting qualities. Mixtures of rye flour with OMP were prepared, replacing 5, 7.5, and 10% rye flour with OMP. The baking quality of the tested flour samples was assessed based on their water absorption, falling number, and amylograph and swelling curve tests. The laboratory baking test was carried out using the sourdough method, prepared based on LV2 starter cultures, and the bread samples were assessed in terms of their technological, sensory, and nutritional characteristics, as well as the antioxidant potential. The OMP was characterized by a high content of basic nutrition components and a higher antioxidant potential. The addition of OMP increased the nutritional value of the rye flour and its water absorption, significantly prolonged the starch gelatinization time, and increased the xylolytic activity of the flour. The OMP enhanced the bread’s dietary fiber, minerals, protein, and phenolic compounds, and boosted its antioxidant potential. Also, the starch present in the bread with OMP was characterized by a higher pro-health value due to a higher share of slowly digestible starch. Incorporating 7.5% OMP into the rye bread formula positively affected the bread’s sensory profile in contrast to the bread with a 10% addition of OMP.

Fawaz Alhazemi

Using mobile crowd sourcing/sensing (MCS) noise monitoring can lead to false sound level reporting. The methods used for recruiting mobile phones in an area of interest vary from selecting full populations to randomly selecting a single phone. Other methods apply a clustering algorithm based on spatial or noise parameters to recruit mobile phones to MCS platforms. However, statistical <i>t</i> tests have revealed dissimilarities between these selection methods. In this paper, we assign these dissimilarities to (1) acoustic characteristics and (2) outlier mobile phones affecting the noise level. We propose two clustering phases for noise level monitoring in MCS platforms. The approach starts by applying spatial clustering to form focused clusters and removing spatial outliers. Then, noise level clustering is applied to eliminate noise level outliers. This creates subsets of mobile phones that are used to calculate the noise level. We conducted a real-world experiment with 25 mobile phones and performed a statistical <i>t</i> test evaluation of the selection methodologies. The statistical values indicated dissimilarities. Then, we compared our proposed method with the noise level clustering method in terms of properly detecting and eliminating outliers. Our method offers <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>4</mn><mo>%</mo></mrow></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>12</mn><mo>%</mo></mrow></semantics></math></inline-formula> higher performance than the noise clustering method.

Emre Yurdusev, Pierre-Luc Trahan, Jonathan Perreault

Isothermal amplification (IA) techniques like rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) have gained significant attention in recent years due to their ability to rapidly amplify DNA or RNA targets at a constant temperature without the need for complex thermal cycling equipment. Such technologies, combined with colorimetric systems rendering visual confirmation of the amplification event, are ideal for the development of point-of-need detection methods suitable for field settings where access to specialized laboratory equipment is limited. The utility of these technologies, thus far limited to DNA and RNA targets, could be broadened to a wide range of targets by using aptamers. Composed of DNA or RNA themselves, aptamers can bind to substances, including proteins, metabolites, and inorganic substances. Their nucleic acid nature can potentially allow them to serve as a bridge, extending the reach of DNA/RNA-centric technologies to the broader molecular world. Indeed, the change in aptamer conformation occurring during ligand interaction can be used to elaborate ligand-responding RCA or LAMP templates. By using an existing aptamer targeting SARS-CoV-2 Spike protein as a model, we explored the possibility of establishing ligand-responsive IA systems. Our study used aptamers with simple sequence modifications as templates in LAMP assays and hyperbranched RCA (HRCA) by exploiting the dynamic nature of the model aptamer to trigger these IA systems. Importantly, our work uniquely demonstrates that this aptamer’s dynamic response to ligand binding can regulate both RCA and LAMP processes. This novel approach of using aptamer conformational changes to trigger LAMP paves the way for new aptamer-based detection assays. Our system detects 50 nM of Spike protein, with LAMP occurring within 30 min in the presence of Spike. The colorimetric readout showed clear results, allowing for the detection of Spike protein presence.

G. I. Pendinen, V. E. Chernov, M. Scholz

Background. Hordeum bulbosum L. is the only wild species of the genus Hordeum, the gene pool of which is successfully used in introgressive hybridization to increase the genetic diversity of H. vulgare L. When creating introgression forms based on hybrids of H. vulgare with H. bulbosum, it is necessary to take into consideration the ploidy of the parent species, and their genetic features that determine the intensity of the process of H. bulbosum chromosomes elimination in embryogenesis. The purpose of our investigation was to study the features associated with the elimination of bulbous barley chromosomes in embryos obtained in various combinations of crosses involving the tetraploid hybrid H. bulbosum with H. vulgare for its effective use in obtaining introgression lines of H. vulgare. Material and methods. The analysis was performed on 9-15 days old embryos obtained in crosses of the tetraploid hybrid F2 (H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x)) (HbHbHvHv) with ‘Igri’ (2x) and ‘Borwina’ (2x) barley varieties, with H. bulbosum A17 (4x), as well as during its self-pollination. The chromosomal composition of embryos of different ages was analyzed on squashed embryo slides using genomic in situ hybridization (GISH). Results. Among the 11-15 days old embryos obtained from self-pollination of the hybrid, approximately half of the studied ones were mixoploids, while in other embryos the majority of cells contained only the genomic material of H. vulgare. The elimination process was very intensive in crosses of the hybrid with the barley varieties ‘Igri’ (2x) and ‘Borwina’ (2x), and by day 10-11 after pollination cells containing only the genomic material of H. vulgare predominated in all embryos, regardless of the direction of crossing and the variety used. Hybrid embryos with a stable chromosomal composition resulted from a cross of a tetraploid hybrid with H. bulbosum A17 (4x). Embryos with recombinant H. vulgare chromosomes carrying alien genetic material of bulbous barley were identified in all types of crosses. Conclusion. The most efficient way for the mass production of introgression lines of cultivated barley varieties based on the partially fertile hybrid F2 (H. bulbosum A17 (4x) × H. vulgare ‘Borwina’ (4x)), is the crossing with varieties of H. vulgare (2x). The progeny from such crosses will contain only cultivated barley plants, among which it is possible to identify forms with the introgression of H. bulbosum and use already the first generation from their self-pollination for selecting H. vulgare lines carrying the genetic material of bulbous barley in both homologs.

Jolanta H. Kotlinska, Pawel Grochecki, Agnieszka Michalak et al.

Repeated maternal separation (MS) is a useful experimental model in rodents for studying the long-term influence of early-life stress on brain neurophysiology. In our work, we assessed the effect of repeated MS (postnatal day (PND)1–21, 180 min/day) on the postnatal development of rat brain regions involved in memory using proton magnetic resonance spectroscopy (¹HMRS) for tissue volume and the level of amino acids such as glutamate, aspartate, glutamine, glycine and gamma-aminobutyric acid (GABA) in the hippocampus. We assessed whether these effects are sex dependent. We also use novel object recognition (NOR) task to examine the effect of MS on memory and the effect of ethanol on it. Finally, we attempted to ameliorate postnatal stress-induced memory deficits by using VU-29, a positive allosteric modulator (PAM) of the metabotropic glutamate type 5 (mGlu5) receptor. In males, we noted deficits in the levels of glutamate, glycine and glutamine and increases in GABA in the hippocampus. In addition, the values of perirhinal cortex, prefrontal cortex and insular cortex and CA3 were decreased in these animals. MS females, in contrast, demonstrated significant increase in glutamate levels and decrease in GABA levels in the hippocampus. Here, the CA1 values alone were increased. VU-29 administration ameliorated these cognitive deficits. Thus, MS stress disturbs amino acids levels mainly in the hippocampus of adult male rats, and enhancement of glutamate neurotransmission reversed recognition memory deficits in these animals.

Ophélie Pila, Christophe Duret, Typhaine Koeppel et al.

The high variability of upper limb motor recovery with robotic training (RT) in subacute stroke underscores the need to explore differences in responses to RT. We explored differences in baseline characteristics and the RT dose between responders (ΔFugl-Meyer Assessment (FMA) score ≥ 9 points; <i>n</i> = 20) and non-responders (<i>n</i> = 16) in people with subacute stroke (mean [SD] poststroke time at baseline, 54 (26) days, baseline FMA score, 23 (17) points) who underwent 16 RT sessions combined with conventional therapies. Baseline characteristics were compared between groups. During RT sessions, the actual practice time (%), number of movements performed, and total distance covered (cm) in assisted and unassisted modalities were compared between groups. At baseline, participant characteristics and FMA scores did not differ between groups. During the RT, non-responders increased practice time (+15%; <i>p</i> = 0.02), performed more movements (+285; <i>p</i> = 0.004), and covered more distance (+4037 cm; <i>p</i> < 10⁻³), with no difference between physical modalities. In contrast, responders decreased practice time (−21%; <i>p</i> = 0.01) and performed fewer movements (−338; <i>p</i> = 0.03) in the assisted modality while performing more movements (+328; <i>p</i> < 0.05) and covering a greater distance (+4779 cm; <i>p</i> = 0.01) in unassisted modalities. Despite a large amount of motor practice, motor outcomes did not improve in non-responders compared to responders: the difficulty level in RT may have been too low for them. Future studies should combine robot-based parameters to describe the treatment dose, especially in people with severe-to-moderate arm paresis, to optimize the RT and improve the recovery prognosis.

Hasan Demir, Hande Demir, Biljana Lončar et al.

One of the essential factors for the selection of the drying process is energy consumption. This study intended to optimize the drying treatment of capers using convection (CD), refractive window (RWD), and vacuum drying (VD) combined with ultrasonic pretreatment by a comparative approach among artificial neural networks (ANN) and response surface methodology (RSM) focusing on the specific energy consumption (SEC). For this purpose, the effects of drying temperature (50, 60, 70 °C), ultrasonication time (0, 20, 40 min), and drying method (RWD, CD, VD) on the SEC value (MJ/g) were tested using a face-centered central composite design (FCCD). RSM (<i>R</i>²: 0.938) determined the optimum drying-temperature–ultrasonication-time values that minimize SEC as; 50 °C-35.5 min, 70 °C-40 min and 70 °C-24 min for RWD, CD and VD, respectively. The conduct of the ANN model is evidenced by the correlation coefficient for training (0.976), testing (0.971) and validation (0.972), which shows the high suitability of the model for optimising specific energy consumption (SEC).

Dr. Lizhi Qian, Jinliang Li, Gongxu Lan et al.

Abstract Transition metal oxide (TMO)‐based anodes attract much attention for lithium storage due to the merits of high theoretical capacity, facile synthesis, and easy scale‐up. Moreover, the increased working potential avoids the issue of lithium dendrites formation and thus improves battery safety. Herein, we propose a route to significantly improve the electrochemical performance of TMO anodes through configurational entropy optimization. For example, high‐entropy oxide (FeCoNiCrCu)3O4 is synthesized by carefully selecting metal elements. The (FeCoNiCrCu)3O4 electrode ensures not only low potential but also holds high capacity. In the half‐cell configuration, the (FeCoNiCrCu)3O4 electrode provides a specific capacity of 575.7 mAh g−1 after 200 cycles at 0.2 A g−1. More importantly, the electrode showed a relatively low discharge voltage of 0.39 V at 0.5 A g−1, which is caused by the configuration entropy optimization. The assembled (FeCoNiCrCu)3O4//LCO coin‐type full cell exhibits a high capacity of 266.3 mAh g−1 after 100 cycles at 0.2 A g−1 and an operating voltage up to 3.9 V.