Application of Mass Transfer Models in Environmental Engineering

Generally, unit operation processes that are used in environmental engineering are involved in interfacial reaction where mass transfer is an extremely essential component for system optimization. The purposes of this chapter were intended to provide the information of both theoretical model development and engineering practice for mass transfer of important processes in environmental engineering. Those processes include, but are not limited to, (1) ozonation (gas–liquid process), (2) ion exchange (liquid–solid process), (3) biological activated carbon (liquid–solid process), (4) chlorination (gas–liquid process), and (5) carbonation (gas–liquid–solid process)

Astroconformer: The Prospects of Analyzing Stellar Light Curves with Transformer-Based Deep Learning Models

Light curves of stars encapsulate a wealth of information about stellar oscillations and granulation, thereby offering key insights into the internal structure and evolutionary state of stars. Conventional asteroseismic techniques have been largely confined to power spectral analysis, neglecting the valuable phase information contained within light curves. While recent machine learning applications in asteroseismology utilizing Convolutional Neural Networks (CNNs) have successfully inferred stellar attributes from light curves, they are often limited by the local feature extraction inherent in convolutional operations. To circumvent these constraints, we present $\textit{Astroconformer}$, a Transformer-based deep learning framework designed to capture long-range dependencies in stellar light curves. Our empirical analysis, which focuses on estimating surface gravity ($\log g$), is grounded in a carefully curated dataset derived from $\textit{Kepler}$ light curves. These light curves feature asteroseismic $\log g$ values spanning from 0.2 to 4.4. Our results underscore that, in the regime where the training data is abundant, $\textit{Astroconformer}$ attains a root-mean-square-error (RMSE) of 0.017 dex around $\log g \approx 3$. Even in regions where training data are sparse, the RMSE can reach 0.1 dex. It outperforms not only the K-nearest neighbor-based model ($\textit{The SWAN}$) but also state-of-the-art CNNs. Ablation studies confirm that the efficacy of the models in this particular task is strongly influenced by the size of their receptive fields, with larger receptive fields correlating with enhanced performance. Moreover, we find that the attention mechanisms within $\textit{Astroconformer}$ are well-aligned with the inherent characteristics of stellar oscillations and granulation present in the light curves.Comment: 13 pages, 9 figures, Submitted to MNRA

Using local ecological knowledge to assess the status of the Critically Endangered Chinese giant salamander Andrias davidianus in Guizhou Province, China

The Critically Endangered Chinese giant salamander Andrias davidianus, the world's largest amphibian, is severely threatened by unsustainable exploitation of wild individuals. However, field data with which to assess the salamander's status, population trends, or exploitation across its geographical range are limited, and recent field surveys using standard ecological field techniques have typically failed to detect wild individuals. We conducted community-based fieldwork in three national nature reserves (Fanjingshan, Leigongshan and Mayanghe) in Guizhou Province, China, to assess whether local ecological knowledge constitutes a useful tool for salamander conservation. We collected a sample of dated salamander sighting records and associated data from these reserves for comparative assessment of the relative status of salamander populations across the region. Although Fanjingshan and Leigongshan are still priority sites for salamander conservation, few recent sightings were recorded in either reserve, and respondents considered that salamanders had declined locally at both reserves. The species may already be functionally extinct at Mayanghe. Although respondent data on threats to salamanders in Guizhou are more difficult to interpret, overharvesting was the most commonly suggested explanation for salamander declines, and it is likely that the growing salamander farming industry is the primary driver of salamander extraction from Guizhou's reserves. Questionnaire-based surveys can collect novel quantitative data that provide unique insights into the local status of salamander populations, and we advocate wide-scale incorporation of this research approach into future salamander field programmes

Abnormal glucose metabolism in virus associated sepsis

Sepsis is identified as a potentially lethal organ impairment triggered by an inadequate host reaction to infection (Sepsis-3). Viral sepsis is a potentially deadly organ impairment state caused by the host’s inappropriate reaction to a viral infection. However, when a viral infection occurs, the metabolism of the infected cell undergoes a variety of changes that cause the host to respond to the infection. But, until now, little has been known about the challenges faced by cellular metabolic alterations that occur during viral infection and how these changes modulate infection. This study concentrates on the alterations in glucose metabolism during viral sepsis and their impact on viral infection, with a view to exploring new potential therapeutic targets for viral sepsis

The pan-inhibitor of Aurora kinases danusertib induces apoptosis and autophagy and suppresses epithelial-to-mesenchymal transition in human breast cancer cells

Danusertib (Danu) is a pan-inhibitor of Aurora kinases and a third-generation breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (Bcr-Abl) tyrosine kinase inhibitor, but its antitumor effect and underlying mechanisms in the treatment of human breast cancer remain elusive. This study aimed to investigate the effects of Danu on the growth, apoptosis, autophagy, and epithelial-to-mesenchymal transition (EMT) and the molecular mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. The results demonstrated that Danu remarkably inhibited cell proliferation, induced apoptosis and autophagy, and suppressed EMT in both breast cancer cell lines. Danu arrested MCF7 and MDA-MB-231 cells in G2/M phase, accompanied by the downregulation of cyclin-dependent kinase 1 and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53. Danu significantly decreased the expression of B-cell lymphoma-extra-large (Bcl-xl) and B-cell lymphoma 2 (Bcl-2), but increased the expression of Bcl-2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and promoted the cleavage of caspases 3 and 9. Furthermore, Danu significantly increased the expression levels of the membrane-bound microtubule-associated protein 1A/1B-light chain 3 (LC3-II) and beclin 1 in breast cancer cells, two markers for autophagy. Danu induced the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (Erk1/2) and inhibited the activation of protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways in breast cancer cells. Treatment with wortmannin (a phosphatidylinositol 3-kinase inhibitor) markedly inhibited Danu-induced activation of p38 MAPK and conversion of cytosolic LC3-I to membrane-bound LC3-II. Pharmacological inhibition and small interfering RNA-mediated knockdown of p38 MAPK suppressed Akt activation, resulting in LC3-II accumulation and enhanced autophagy. Pharmacological inhibition and small interfering RNA-mediated knockdown of Erk1/2 also remarkably increased the level of LC3-II in MCF7 cells. Moreover, Danu inhibited EMT in both MCF7 and MDA-MB-231 cells with upregulated E-cadherin and zona occludens protein 1 (ZO-1) but downregulated N-cadherin, zinc finger E-box-binding homeobox 1 (TCF8/ZEB1), snail, slug, vimentin, and β-catenin. Notably, Danu showed lower cytotoxicity toward normal breast epithelial MCF10A cells. These findings indicate that Danu promotes cellular apoptosis and autophagy but inhibits EMT in human breast cancer cells via modulation of p38 MAPK/Erk1/2/Akt/mTOR signaling pathways. Danu may represent a promising anticancer agent for breast cancer treatment. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Danu in breast cancer therapy

GABA, progesterone and zona pellucida activation of PLA2 and regulation by MEK-ERK1/2 during acrosomal exocytosis in guinea pig spermatozoa

AbstractWe investigated whether GABA activates phospholipase A2 (PLA2) during acrosomal exocytosis, and if the MEK-ERK1/2 pathway modulates PLA2 activation initiated by GABA, progesterone or zona pellucida (ZP). In guinea pig spermatozoa prelabelled with [14C]arachidonic acid or [14C]choline chloride, GABA stimulated a decrease in phosphatidylcholine (PC), and release of arachidonic acid and lysoPC, during exocytosis. These lipid changes are indicative of PLA2 activation and appear essential for exocytosis since inclusion of aristolochic acid (a PLA2 inhibitor) abrogated them, along with exocytosis. GABA activation of PLA2 seems to be mediated, at least in part, by diacylglycerol (DAG) and protein kinase C since inclusion of the DAG kinase inhibitor R59022 enhanced PLA2 activity and exocytosis stimulated by GABA, whereas exposure to staurosporine decreased both. GABA-, progesterone- and ZP-induced release of arachidonic acid and exocytosis were prevented by U0126 and PD98059 (MEK inhibitors). Taken together, our results suggest that PLA2 plays a fundamental role in agonist-stimulated exocytosis and that MEK-ERK1/2 are involved in PLA2 regulation during this process

Recent advances in carbon dioxide utilization

Carbon dioxide (CO2) is the major contributor to greenhouse gas (GHG) emissions and the main driver of climate change. Currently, CO2 utilization is increasingly attracting interest in processes like enhanced oil recovery and coal bed methane and it has the potential to be used in hydraulic fracturing processes, among others. In this review, the latest developments in CO2 capture, utilization, conversion, and sequestration are examined through a multi-scale perspective. The diverse range of CO2 utilization applications, including mineralization, biological utilization, food and beverages, energy storage media, and chemicals, is comprehensively presented. We also discuss the worldwide research and development of CO2 utilization projects. Lastly, we examine the key challenges and issues that must be faced for pilot-scale and industrial applications in the future. This study demonstrates that CO2 utilization can be a driver for the future development of carbon capture and utilization technologies. However, considering the amount of CO2 produced globally, even if it can be reduced in the near-to mid-term future, carbon capture and storage will remain the primary strategy and, so, complementary strategies are desirable. Currently, the main CO2 utilization industry is enhanced oil and gas recovery, but considering the carbon life cycle, these processes still add CO2 to the atmosphere. In order to implement other CO2 utilization technologies at a large scale, in addition to their current technical feasibility, their economic and societal viability is critical. Therefore, future efforts should be directed toward reduction of energy penalties and costs, and the introduction of policies and regulation encouraging carbon capture, utilization and storage, and increasing the public acceptance of the strategies in a complementary manner

Protective Effects of Total Saponins of Panax Notoginseng on Steroid-Induced Avascular Necrosis of the Femoral Head In Vivo and In Vitro

This research was designed to investigate the protective effects of TSPN on steroid-induced avascular necrosis of the femoral head (ANFH) and the likely mechanisms of those effects. As an in vivo study, TSPN was shown to be protective against steroid-induced ANFH due to the upregulation of VEGF-A. Furthermore, TSPN attenuated the apoptosis of osteocytes and reduced the expression of Caspase-3 relative to the model group. As an in vitro study, TSPN exerted a concentration-dependent protective effect against apoptosis in MC3T3-E1 cells. Moreover, TSPN (at a dose of 100 μg/mL) significantly reversed the dexamethasone-induced augmentation of Caspase-3 expression and activity. Therefore, our study demonstrated that TSPN had a protective effect against steroid-induced ANFH that was related to the upregulation of VEGF-A and the inhibition of apoptosis and Caspase-3 activation