Innovation in lignocellulosics dewatering and drying for energy sustainability and enhanced utilization of forestry, agriculture, and marine resources - A review.

Efficient utilization of forestry, agriculture, and marine resources in various manufacturing sectors requires optimizing fiber transformation, dewatering, and drying energy consumption. These processes play a crucial role in reducing the carbon footprint and boosting sustainability within the circular bioeconomy framework. Despite efforts made in the paper industry to enhance productivity while conserving resources and energy through lower grammage and higher machine speeds, reducing thermal energy consumption during papermaking remains a significant challenge. A key approach to address this challenge lies in increasing dewatering of the fiber web before entering the dryer section of the paper machine. Similarly, the production of high-value-added products derived from alternative lignocellulosic feedstocks, such as nanocellulose and microalgae, requires advanced dewatering techniques for techno-economic viability. This critical and systematic review aims to comprehensively explore the intricate interactions between water and lignocellulosic surfaces, as well as the leading technologies used to enhance dewatering and drying. Recent developments in technologies to reduce water content during papermaking, and advanced dewatering techniques for nanocellulosic and microalgal feedstocks are addressed. Existing research highlights several fundamental and technical challenges spanning from the nano- to macroscopic scales that must be addressed to make lignocellulosics a suitable feedstock option for industry. By identifying alternative strategies to improve water removal, this review intends to accelerate the widespread adoption of lignocellulosics as feasible manufacturing feedstocks. Moreover, this review aims to provide a fundamental understanding of the interactions, associations, and bonding mechanisms between water and cellulose fibers, nanocellulosic materials, and microalgal feedstocks. The findings of this review shed light on critical research directions necessary for advancing the efficient utilization of lignocellulosic resources and accelerating the transition towards sustainable manufacturing practices.

Optimizing Bleaching Operating Conditions Based on Mathematical Programming to Reduce AOX Emissions.

This study describes the optimization of a eucalyptus elemental chlorine-free (ECF) bleach plant to reduce adsorbable organic halogen (AOX). The correlations between operating conditions of each stage and pulp quality indices as well as the AOX content in wastewater are analyzed, taking an ECF bleaching technology (D0EpPD1) as an example. The calculation models of pulp quality indices and AOX content in wastewater are established. Then, an optimization model aiming at minimizing AOX emission is structured. The model shows a good simulation effect because the errors between the calculated and experimental values are within 6.3%. By analyzing the impact of various operating conditions on AOX emissions, it was found that chlorine dioxide reduced in the D0 stage has the greatest impact on AOX. The optimization results show that AOX can be reduced from 90.84 to 79.58 kg/h, a decrease of 12.5%. The verification experiment results based on the optimized operating conditions showed that the experimental results are in good agreement with the calculated results of the optimization model, and the effect of reducing AOX based on the optimization model is obvious.

Carcinogenic effects in a phenylketonuria mouse model.

Phenylketonuria (PKU) is a metabolic disorder caused by impaired phenylalanine hydroxylase (PAH). This condition results in hyperphenylalaninemia and elevated levels of abnormal phenylalanine metabolites, among which is phenylacetic acid/phenylacetate (PA). In recent years, PA and its analogs were found to have anticancer activity against a variety of malignancies suggesting the possibility that PKU may offer protection against cancer through chronically elevated levels of PA. We tested this hypothesis in a genetic mouse model of PKU (PAH(enu2)) which has a biochemical profile that closely resembles that of human PKU. Plasma levels of phenylalanine in homozygous (HMZ) PAH(enu2) mice were >12-fold those of heterozygous (HTZ) littermates while tyrosine levels were reduced. Phenylketones, including PA, were also markedly elevated to the range seen in the human disease. Mice were subjected to 7,12 dimethylbenz[a]anthracene (DMBA) carcinogenesis, a model which is sensitive to the anticancer effects of the PA derivative 4-chlorophenylacetate (4-CPA). Tumor induction by DMBA was not significantly different between the HTZ and HMZ mice, either in total tumor development or in the type of cancers that arose. HMZ mice were then treated with 4-CPA as positive controls for the anticancer effects of PA and to evaluate its possible effects on phenylalanine metabolism in PKU mice. 4-CPA had no effect on the plasma concentrations of phenylalanine, phenylketones, or tyrosine. Surprisingly, the HMZ mice treated with 4-CPA developed an unexplained neuromuscular syndrome which precluded its use in these animals as an anticancer agent. Together, these studies support the use of PAH(enu2) mice as a model for studying human PKU. Chronically elevated levels of PA in the PAH(enu2) mice were not protective against cancer.

Recovery and STR amplification of DNA from RFLP membranes.

Restriction fragment length polymorphism (RFLP) techniques were utilized in the forensic DNA community until the mid 1990s when less labor-intensive polymerase chain reaction short tandem repeat (PCR STR) techniques became available. During the transition from RFLP technology to PCR-based STR platforms, a method for comparing RFLP profiles to STR profiles was not developed. While the preferred approach for applying new technology to old cases would be to analyze the original biological stain, this is not always possible. For unsolved cases that previously underwent RFLP analysis, the only DNA remaining may be restriction cut and bound to nylon membranes. These studies investigate several methods for obtaining STR profiles from membrane bound DNA, including removal of bound DNA with bases, acids, detergents, various chemicals, and conventional cell extraction solutions. Direct multiplex STR amplification of template in the membrane-bound state was also explored. A partial STR profile was obtained from DNA that was recovered from an archived membrane using conventional extraction buffer components, indicating promise for recovering useful STR information from RFLP membranes that have been maintained in long-term frozen storage.

ENU mutagenesis in the mouse.

This unit describes the treatment of laboratory mice with the mutagen N-ethyl-N-nitrosourea (ENU) to achieve very highly induced rates of mutation throughout the genome. Further, it describes several popular mating schemes designed to produce animals displaying phenotypes associated with the induced mutations.

High levels of orexin A in the brain of the mouse model for phenylketonuria: possible role of orexin A in hyperactivity seen in children with PKU.

Phenylketonuria (PKU) is a metabolic disorder caused by phenylalanine hydroxylase deficiency leading to increased levels of phenylalanine in the brain. Hyperactivity is reportedly induced by a high level of orexin A, and therefore orexin A content was studied in the PKU mice. Hypothalamus and brain stem had higher levels of orexin A compared to cerebrum and cerebellum both in wild type and PKU mice brains as observed by radioimmunoassay method. Interestingly, all these regions of the brain in PKU mouse showed a higher level of orexin A compared to the wild type. Heart and plasma also had higher levels of orexin A in PKU compared to the wild type. Immunohistochemical analysis revealed an increased number of orexin A-stained cells in the brain and heart of PKU mouse compared to the wild type. This is the first report of increased level of orexin in the PKU mouse brain. Hyperactivity is commonly observed in children with PKU; thus these findings suggest that orexin A is a contributing factor for the hyperactivity.

Oxidative stress in a phenylketonuria animal model.

Oxidative stress is seen in various metabolic disorders for unknown reasons. Oxidative stress is defined as an imbalance between pro-oxidant and antioxidant status in favor of the former. This study investigated whether oxidative stress exists in phenylketonuria (PKU) using the BTBR-Pah(enu2) animal model for PKU. Animals (14-24 weeks old) were sacrificed and brain and red blood cells (RBCs) were obtained aseptically. The lipid peroxidation by-product, evaluated as malondialdehyde (MDA), was significantly higher in the brains and RBCs of PKU animals (n = 6) than in controls (n = 6). Glutathione/glutathione disulfide, a good indicator for tissue thiol status, was significantly decreased both in the brains and RBCs. Some antioxidant enzymes were also analyzed in RBCs, including glucose-6-phosphate dehydrogenase (G6PD), which provides the RBC's main reducing power, reduced nicotinamide adenine dinucleotide phosphate (NADPH), and catalase detoxifies H2O2 by catalyzing its reduction to O2 and H2O. Both catalase and G6PD were significantly increased in the RBCs of PKU animals.

Efficient generation and mapping of recessive developmental mutations using ENU mutagenesis.

Treatment with N-ethyl-N-nitrosourea (ENU) efficiently generates single-nucleotide mutations in mice. Along with the renewed interest in this approach, much attention has been given recently to large screens with broad aims; however, more finely focused studies have proven very productive as well. Here we show how mutagenesis together with genetic mapping can facilitate the rapid characterization of recessive loci required for normal embryonic development. We screened third-generation progeny of mutagenized mice at embryonic day (E) 18.5 for abnormalities of organogenesis. We ascertained 15 monogenic mutations in the 54 families that were comprehensively analyzed. We carried out the experiment as an outcross, which facilitated the genetic mapping of the mutations by haplotype analysis. We mapped seven of the mutations and identified the affected locus in two lines. Using a hierarchical approach, it is possible to maximize the efficiency of this analysis so that it can be carried out easily with modest infrastructure and resources.