Sustainable Lignin Extraction Using a Mild Acidic γ-Valerolactone Process for the Identification of White and Red Oaks.

Current wood identification struggles to differentiate white and red oak (Quercus alba and Quercus rubra) due to highly similar microstructures, as demonstrated by morphological microscope analysis. The present research explores lignin composition as a potential discriminating factor. Here, a rapid and sustainable method for extracting high-quality lignin from oak samples using acidic γ-valerolactone (GVL) under mild conditions is described. As-extracted lignin is thoroughly characterized using various analytical methods, and results reveal a distinct structural difference between the lignin from the two species. White oak lignin possesses a unique "Hibbert ketone" unit detectable by nuclear magnetic resonance spectroscopy (NMR), which is absent in red oak lignin. In addition, infrared spectroscopy differentiates the species based on specific carbonyl groups present in their lignin. These findings suggest that identifying the presence of the Hibbert ketone unit in lignin may offer a highly efficient and reliable method for differentiating white and red oak, opening new avenues for wood identification.

[Development and application of a rapid scheme for detection of respiratory virus nucleic acid].

This study aimed to develop a portable, accurate and easy-to-operate scheme for rapid detection of respiratory virus nucleic acid. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the effect of extraction-free respiratory virus treatment reagent (RTU) on viral nucleic acid treatment and the effect of ultra-fast fluorescence quantitative PCR instrument (FQ-8A) on nucleic acid amplification, respectively. RTU and FQ-8A were combined to develop a rapid detection scheme for respiratory virus nucleic acid, and the positive detection rate was judged by Ct value using a fluorescence quantitative PCR instrument, and the accuracy of the scheme in clinical samples detection was investigated. The results showed that RTU had comparable sensitivity to the automatic nucleic acid extraction instrument, its extraction efficiency was comparable to the other 3 extraction methods when extracting samples of different virus types, but the extraction time of RTU was less than 5 min. FQ-8A had good consistency in detection respiratory syncytial virus (RSV) and adenovirus (ADV) compared with the control instrument ABI-7500, with kappa coefficients of 0.938 (P < 0.001) and 0.887 (P < 0.001), respectively, but the amplification time was only about 0.5 h. The RTU and FQ-8A combined rapid detection scheme had a highly consistent detection rate with the conventional detection scheme, with a sensitivity of 91.70% and specificity of 100%, and a kappa coefficient was 0.944 (P < 0.001). In conclusion, by combining RTU with FQ-8A, a rapid respiratory virus nucleic acid detection scheme was developed, the whole process could be completed in 35 min. The scheme is accurate and easy-to-operate, and can provide important support for the rapid diagnosis and treatment of respiratory virus.

Kynurenic acid blunts A1 astrocyte activation against neurodegeneration in HIV-associated neurocognitive disorders.

Despite extensive astrocyte activation in patients suffering from HIV-associated neurocognitive disorders (HAND), little is known about the contribution of astrocytes to HAND neuropathology. Here, we report that the robust activation of neurotoxic astrocytes (A1 astrocytes) in the CNS promotes neuron damage and cognitive deficits in HIV-1 gp120 transgenic mice. Notably, knockout of α7 nicotinic acetylcholine receptors (α7nAChR) blunted A1 astrocyte responses, ultimately facilitating neuronal and cognitive improvement in the gp120tg mice. Furthermore, we provide evidence that Kynurenic acid (KYNA), a tryptophan metabolite with α7nAChR inhibitory properties, attenuates gp120-induced A1 astrocyte formation through the blockade of α7nAChR/JAK2/STAT3 signaling activation. Meanwhile, compared with gp120tg mice, mice fed with tryptophan showed dramatic improvement in cognitive performance, which was related to the inhibition of A1 astrocyte responses. These initial and determinant findings mark a turning point in our understanding of the role of α7nAChR in gp120-mediated A1 astrocyte activation, opening up new opportunities to control neurotoxic astrocyte generation through KYNA and tryptophan administration.

Reducing the Effectiveness of Ward Particulate Matter, Bacteria and Influenza Virus by Combining Two Complementary Air Purifiers.

Air purifiers should pay much attention to hospital-associated infections, but the role of a single air purifier is limited. The goal of this study was to evaluate the effectiveness of the combined application of the nonequilibrium positive and negative oxygen ion purifier (PNOI) and the high-efficiency particulate air filter (HEPA) on a complex, polluted environment. Two of the better performing purifiers were selected before the study. The efficacy of their use alone and in combination for purification of cigarette particulate matter (PM), Staphylococcus albicans, and influenza virus were then evaluated under a simulated contaminated ward. PNAI and HEPA alone are deficient. However, when they were combined, they achieved 98.44%, 99.75%, and 100% 30 min purification rates for cigarette PM, S. albus, and influenza virus, respectively. The purification of pollution of various particle sizes and positions was optimized and reduced differentials, and a subset of airborne influenza viruses is inactivated. Furthermore, they were superior to ultraviolet disinfection for microbial purification in air. This work demonstrates the strong purification capability of the combined application of these two air purifiers for complex air pollution, which provides a new idea for infection control in medical institutions.

Enhancement of the production of bio-aromatics from renewable lignin by combined approach of torrefaction deoxygenation pretreatment and shape selective catalytic fast pyrolysis using metal modified zeolites.

In this work, combined approach of torrefaction deoxygenation pretreatment (TDP) and shape selective catalytic fast pyrolysis (SS-CFP) using bifunctional catalyst (metal modified HZSM-5) were employed to improve the yield of bio-BTX derived from the renewable starting material of lignin. Results showed that after TDP, the oxygen element could be removed effectively. The oxygen removal efficiency reached its maximum value of 22.27% at 300 °C, resulting in markedly decrease of unnecessary oxygenates in bio-oil. Compared to parent HZSM-5, all metal modified HZSM-5 (Ga/HZSM-5, Zn/HZSM-5, and Ga-Zn/HZSM-5) promoted the formation of bio-BTX. Zn/HZSM-5 showed the highest selective yield of bio-BTX because of the enhancement deoxygenation reaction of oxygenates and the aromatization reaction of olefins. The combined approach of TDP and SS-CFP remarkably improved the selective yield of bio-BTX, reaching the maximum value of 65.19%, which was much higher than that from single approach of TDP (33.84%) and SS-CFP (47.36%).

Research on pyrolysis behavior of Camellia sinensis branches via the Discrete Distributed Activation Energy Model.

This study aims at investigating the pyrolysis behavior of Camellia sinensis branches by the Discrete Distributed Activation Energy Model (DAEM) and thermogravimetric experiments. Then the Discrete DAEM method is used to describe pyrolysis process of Camellia sinensis branches dominated by 12 characterized reactions. The decomposition mechanism of Camellia sinensis branches and interaction with components are observed. And the reaction at 350.77°C is a significant boundary of the first and second reaction range. The pyrolysis process of Camellia sinensis branches at the heating rate of 10,000°C/min is predicted and provides valuable references for gasification or combustion. The relationship and function between four typical indexes and heating rates from 10 to 10,000°C/min are revealed.