Characterization of lycopene ß-cyclase from Dunaliella bardawil for enhanced ß-carotene production and salt tolerance.

Dunaliella can accumulate more ß-carotene (10 % or even more of the dry weight of cells) than any other species. Lycopene ß-cyclase (LcyB) is the key enzyme in the catalysis of lycopene to ß-carotene. In the present research, we used Escherichia coli BL21 (DE3) as host to construct two different types of engineering bacteria, one expressing the D. bardawil LcyB and the other expressing the orthologue Erwinia uredovora crtY. The catalytic ability of LcyB and CrtY were evaluated by comparing the ß-carotene yields of the two E. coli BL21(DE3) strains, whose salt tolerance was simultaneously compared by cultivated them under different NaCl concentrations (1 %, 2 %, and 4 %). We also interfered with the LcyB gene to investigate the effect of LcyB in D. bardawil. Results displayed that the ß-carotene yield of the LcyB-transformant significantly increased by about 48 % compared with the crtY-transformant. Additionally, LcyB was verified to be able to enhance the salt tolerance of E. coli BL21 (DE3). It is concluded that D. bardawil LcyB not only has better catalytic ability but also is able to confer salt tolerance to cells. Interfering D. bardawil LcyB induced the low expression of LcyB and the changes of growth and carotenoids metabolism in D. bardawil.

A novel intelligent fault diagnosis method for gearbox based on multi-dimensional attention denoising convolution.

In the field of intelligent fault diagnosis, particularly concerning rotating machinery, convolutional neural networks (CNNs) face significant challenges when applied to real industrial vibration data. These data are not only contaminated by various types of noise but also exhibit fault features that vary across different scales. Consequently, the effective suppression of extraneous noise and accurate extraction of multi-scale fault features are crucial issues. To address these challenges, this study proposes a novel deep neural network framework, termed the Multidimensional Fusion Residual Attention Network (MFRANet), for gearbox fault diagnosis. The MFRANet employs a multi-scale deep separable convolution module to thoroughly investigate the fundamental characteristics of the original vibration signals in both the time and time-frequency domains. To enhance the detailed analysis of diagnostic data and mitigate the risks of overfitting and noise interference, an efficient residual channel attention module is incorporated to weight and denoise the feature maps. Additionally, an external attention module is introduced to create implicit connections between the denoised multi-scale feature maps and to highlight potential correlations within the sample data, thereby improving the accuracy of fault diagnosis. Experimental evaluations on a gearbox fault dataset demonstrate that the proposed method surpasses several benchmark and state-of-the-art techniques in terms of diagnostic performance, exhibiting robust noise resilience across various noise levels. This indicates enhanced reliability and accuracy in gearbox fault diagnosis, providing an innovative and efficient solution for fault diagnosis in rotating machinery. The study underscores the contributions of artificial intelligence through the innovative structure of the method and the integration of advanced deep learning modules, while its engineering application is evidenced by addressing practical challenges in rotating machinery fault diagnosis. This work meets the urgent need for reliable diagnostic methods in industrial environments.

Thioredoxin reductase inhibition and glutathione depletion mediated by glaucocalyxin A promote intracellular disulfide stress in gastric cancer cells.

Thioredoxin reductase 1 (TXNRD1) has been identified as one of the promising chemotherapeutic targets in cancer cells. Therefore, a novel TXNRD1 inhibitor could accelerate chemotherapy in clinical anticancer research. In this study, glaucocalyxin A (GlauA), a natural diterpene extracted from Rabdosia japonica var. glaucocalyx, was identified as a novel inhibitor of TXNRD1. We found that GlauA effectively inhibited recombinant TXNRD1 and reduced its activity in gastric cancer cells without affecting the enzyme's expression level. Mechanistically, the selenocysteine residue (U498) of TXNRD1 was irreversibly modified by GlauA through a Michael addition. Additionally, GlauA formed a covalent adduct with glutathione (GSH) and disrupted cellular redox balance by depleting cellular GSH. The inhibition of TXNRD1 and depletion of GSH by GlauA conferred its cytotoxic effects in spheroid culture and Transwell assays in AGS cells. The disulfide stress induced cytotoxicity of GlauA could be mitigated by adding reducing agents, such as DTT and ß-ME. Furthermore, the FDA-approval drug auranofin, a TXNRD1 inhibitor, triggered oligomerization of the cytoskeletal protein Talin-1 in AGS cells, indicating that inhibiting TXNRD1 triggered disulfide stress. In conclusion, this study uncovered GlauA as an efficient inhibitor of TXNRD1 and demonstrated the potential of TXNRD1 inhibition as an effective anticancer strategy by disrupting redox homeostasis and inducing disulfide stress.

Determination of Lubrication Layer Thickness and Its Effect on Concrete Pumping Pressure.

The flow of six kinds of fresh concrete under different flow rates and lubrication layer thickness (TLL) values in the horizontal pipe was numerically simulated. The influence of the TLL on the pressure per unit length (PL) was analyzed. It was determined that the formation of the lubrication layer (LL) significantly reduces the PL in concrete pumping. As the TLL increased, the PL decreased. However, the degree of reduction in the PL gradually decreased as the TLL increased. Relating the simulated PL with the experimental PL, the size of the TLL was obtained, which was between 1 and 3 mm. The minimum and maximum were 1.23 and 2.58 mm, respectively, and the average value was 1.97 mm. The strength (S24, S50), the size of the aggregate (A10, A20, A25), and the flow rate of pumping all affected the TLL. The type of fresh concrete and the flow rate of pumping significantly affected the PL, which impacted the TLL. However, the TLL also impacted the PL. Finally, this made the TLL change within a certain range. When PL > 14,000 Pa/m, 2 mm < TLL< 3 mm; on the other hand, 1 mm < TLL< 2 mm. Therefore, we can use CFD to simulate the flow of all types of concrete in the actual pumping pipeline with a TLL of 2 mm to obtain their pumping pressure and guide the actual construction.

The Efficacy and Safety of Bevacizumab Plus Anti-PD-1/PD-L1 Inhibitors in Combination with Hepatic Arterial Infusion Chemotherapy for Initially Unresectable Hepatocellular Carcinoma.

Objection: To report the efficacy and safety of triple combination therapy with bevacizumab plus anti-PD-1 (BP1) or anti-PD-L1 inhibitors (BPL) combined with hepatic arterial infusion chemotherapy (HAIC) as a first-line treatment for initially unresectable hepatocellular carcinoma (uHCC). Methods: In this retrospective study, patients with initially uHCC received either BP1-HAIC or BPL-HAIC as first-line treatment. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), objective response rate (ORR) and disease control rate (DCR). Results: Between January 2020 and December 2022, a total of 136 patients with initially uHCC received triple combination therapy, with 76 in the BP1-HAIC group and 60 in the BPL-HAIC group. The median PFS for the entire cohort was 11.1 months (95% CI, 8.0-13.7 months), and the median OS was 22.4 months (95% CI, 21.3- not reached). Comparative analysis revealed no significant differences in PFS (HR, 0.91, P = 0.69) or OS (HR, 0.71, P = 0.31) between the BP1-HAIC and BPL-HAIC groups. The ORR was 46.3% per RECIST v1.1 and 66.9% per mRECIST, with a DCR of 83.1% under both criteria. Common adverse events (AEs) included hypoalbuminemia and elevated aspartate/alanine aminotransferase, with 5.1% (7/136) experienced upper gastrointestinal bleeding. Multivariate Cox analysis identified tumor number and BCLC stage as independent prognostic factors for OS, and tumor number for PFS. Conclusion: Triple combination therapy demonstrated significant therapeutic efficacy and tumor response in initially uHCC. No notable differences in outcomes were observed between the BP1-HAIC and BPL-HAIC groups. AEs were manageable in clinical practice.

Effects of different microplastic types on soil physicochemical properties, enzyme activities, and bacterial communities.

Global concern continues to mount regarding the accumulation of microplastics (MPs) in soil. However, little is known about how various types of MPs influence the properties of soil ecosystems. Here, we evaluated the effects of six different types of MPs, including low-density polyethylene (LDPE), polyamide (PA), polystyrene (PS), polyhydroxy-alkanoates (PHA), polybutadiene styrene (PBS), and polylactide (PLA), on soil physicochemical properties, enzyme activities, and microbial communities. At the end of a 230-day soil incubation, we observed significant changes in soil moisture content, soil organic carbon, pH, NH4+-N, NO3--N, and available phosphorus. The addition of MPs had a significant influence on the activities of soil ß-glucosidase, acid phosphatase, urease, and fluorescein diacetate hydrolase, with effects varying with MP type. Results of 16S rRNA gene high throughput sequencing showed that MP exposure had little effect on soil microbial alpha diversity, but that PHA contamination significantly reduced ACE, Chao1, and Shannon index values. MP contamination also altered soil microbial community composition. In particular, the relative abundance of Firmicutes increased significantly while the relative abundance of Actinobacteriota, Proteobacteria (especially the nitrogen-fixing rhizobia), and Acidobacteriota decreased following exposure to PHA. Redundancy analysis showed that acid phosphatase and pH were the two main environmental factors affecting bacterial community structure at the phylum and order levels. Furthermore, Tax4Fun2 analysis found that MP treatment disrupted fundamental bacterial metabolic pathways. Our findings indicate that different types of MPs can affect soil fertility, bacterial community structure, and function in various ways, and highlight that biodegradable MPs may alter soil bacterial communities more than conventional MPs.

Adversarial training collaborating hybrid convolution-transformer network for automatic identification of reactive lymphocytes in peripheral blood.

Reactive lymphocytes may indicate diseases such as viral infections. Identifying these abnormal lymphocytes is crucial for disease diagnosis. Currently, reactive lymphocytes are mainly manually identified by pathological experts with microscopes and morphological knowledge, which is time-consuming and laborious. Some studies have used convolutional neural networks (CNNs) to identify peripheral blood leukocytes, but there are limitations in the small receptive field of the model. Our model introduces a transformer based on CNN, expands the receptive field of the model, and enables it to extract global features more efficiently. We also enhance the generalization ability of the model through virtual adversarial training (VAT) without changing the parameters of the model. Finally, our model achieves an overall accuracy of 93.66% on the test set, and the accuracy of reactive lymphocytes also reaches 88.03%. This work takes another step toward the efficient identification of reactive lymphocytes.

GOI-YOLOv8 Grouping Offset and Isolated GiraffeDet Low-Light Target Detection.

In the realm of computer vision, object detection holds significant importance and has demonstrated commendable performance across various scenarios. However, it typically requires favorable visibility conditions within the scene. Therefore, it is imperative to explore methodologies for conducting object detection under low-visibility circumstances. With its balanced combination of speed and accuracy, the state-of-the-art YOLOv8 framework has been recognized as one of the top algorithms for object detection, demonstrating outstanding performance results across a range of standard datasets. Nonetheless, current YOLO-series detection algorithms still face a significant challenge in detecting objects under low-light conditions. This is primarily due to the significant degradation in performance when detectors trained on illuminated data are applied to low-light datasets with limited visibility. To tackle this problem, we suggest a new model named Grouping Offset and Isolated GiraffeDet Target Detection-YOLO based on the YOLOv8 architecture. The proposed model demonstrates exceptional performance under low-light conditions. We employ the repGFPN feature pyramid network in the design of the feature fusion layer neck to enhance hierarchical fusion and deepen the integration of low-light information. Furthermore, we refine the repGFPN feature fusion layer by introducing a sampling map offset to address its limitations in terms of weight and efficiency, thereby better adapting it to real-time applications in low-light environments and emphasizing the potential features of such scenes. Additionally, we utilize group convolution to isolate interference information from detected object edges, resulting in improved detection performance and model efficiency. Experimental results demonstrate that our GOI-YOLO reduces the parameter count by 11% compared to YOLOv8 while decreasing computational requirements by 28%. This optimization significantly enhances real-time performance while achieving a competitive increase of 2.1% in Map50 and 0.6% in Map95 on the ExDark dataset.

Pharmacological Inhibition of TXNRD1 by a Small Molecule Flavonoid Butein Overcomes Cisplatin Resistance in Lung Cancer Cells.

Mammalian cytosolic selenoprotein thioredoxin reductase (TXNRD1) is crucial for maintaining the reduced state of cellular thioredoxin 1 (TXN1) and is commonly up-regulated in cancer cells. TXNRD1 has been identified as an effective target in cancer chemotherapy. Discovering novel TXNRD1 inhibitors and elucidating the cellular effects of TXNRD1 inhibition are valuable for developing targeted therapies based on redox regulation strategies. In this study, we demonstrated that butein, a plant-derived small molecule flavonoid, is a novel TXNRD1 inhibitor. We found that butein irreversibly inhibited recombinant TXNRD1 activity in a time-dependent manner. Using TXNRD1 mutant variants and LC-MS, we identified that butein modifies the catalytic cysteine (Cys) residues of TXNRD1. In cellular contexts, butein promoted the accumulation of reactive oxygen species (ROS) and exhibited cytotoxic effects in HeLa cells. Notably, we found that pharmacological inhibition of TXNRD1 by butein overcame the cisplatin resistance of A549 cisplatin-resistant cells, accompanied by increased cellular ROS levels and enhanced expression of p53. Taken together, the results of this study demonstrate that butein is an effective small molecule inhibitor of TXNRD1, highlighting the therapeutic potential of inhibiting TXNRD1 in platinum-resistant cancer cells.

Redox pathways in melanoma.

Cases of melanoma are doubling every 12 years, and in stages III and IV, the disease is associated with high mortality rates concomitant with unresectable metastases and therapeutic drug resistance. Despite some advances in treatment success, there is a marked need to understand more about the pathology of the disease. The present review provides an overview of how melanoma cells use and modulate redox pathways to facilitate thiol homeostasis and melanin biosynthesis and describes plausible redox targets that may improve therapeutic approaches in managing malignant disease and metastasis. Melanotic melanoma has some unique characteristics. Making melanin requires a considerable dedication of cellular energy resources and utilizes glutathione and glutathione transferases in certain steps in the biosynthetic pathway. Melanin is an antioxidant but is also functionally important in hematopoiesis and influential in various aspects of host immune responses, giving it unique characteristics. Together with other redox traits that are specific to melanoma, a discussion of possible therapeutic approaches is also provided.

EC-YOLO: Improved YOLOv7 Model for PCB Electronic Component Detection.

Electronic components are the main components of PCBs (printed circuit boards), so the detection and classification of ECs (electronic components) is an important aspect of recycling used PCBs. However, due to the variety and quantity of ECs, traditional target detection methods for EC classification still have problems such as slow detection speed and low performance, and the accuracy of the detection needs to be improved. To overcome these limitations, this study proposes an enhanced YOLO (you only look once) network (EC-YOLOv7) for detecting EC targets. The network uses ACmix (a mixed model that enjoys the benefits of both self-attention and convolution) as a substitute for the 3 × 3 convolutional modules in the E-ELAN (Extended ELAN) architecture and implements branch links and 1 × 1 convolutional arrays between the ACmix modules to improve the speed of feature retrieval and network inference. Furthermore, the ResNet-ACmix module is engineered to prevent the leakage of function data and to minimise calculation time. Subsequently, the SPPCSPS (spatial pyramid pooling connected spatial pyramid convolution) block has been improved by replacing the serial channels with concurrent channels, which improves the fusion speed of the image features. To effectively capture spatial information and improve detection accuracy, the DyHead (the dynamic head) is utilised to enhance the model's size, mission, and sense of space, which effectively captures spatial information and improves the detection accuracy. A new bounding-box loss regression method, the WIoU-Soft-NMS method, is finally suggested to facilitate prediction regression and improve the localisation accuracy. The experimental results demonstrate that the enhanced YOLOv7 net surpasses the initial YOLOv7 model and other common EC detection methods. The proposed EC-YOLOv7 network reaches a mean accuracy (mAP@0.5) of 94.4% on the PCB dataset and exhibits higher FPS compared to the original YOLOv7 model. In conclusion, it can significantly enhance high-density EC target recognition.

Photo-uncaging Triggers on Self-Blinking to Control Single-Molecule Fluorescence Kinetics for Super-resolution Imaging.

Super-resolution imaging, especially a single-molecule localization approach, has raised a fluorophore engineering revolution chasing sparse single-molecule dark-bright blinking transforms. Yet, it is a challenge to structurally devise fluorophores manipulating the single-molecule blinking kinetics. In this pursuit, we have developed a triggering strategy by innovatively integrating the photoactivatable nitroso-caging strategy into self-blinking sulfonamide to form a nitroso-caged sulfonamide rhodamine (NOSR). Our fluorophore demonstrated controllable self-blinking events upon phototriggered caging unit release. This exceptional blink kinetics improved the super-resolution imaging integrity on microtubules compared to self-blinking analogues. With the aid of paramount single-molecule fluorescence kinetics, we successfully reconstructed the ring structure of nuclear pores and the axial morphology of mitochondrial outer membranes. We foresee that our synthetic approach of photoactivation and self-blinking would facilitate rhodamine devising for super-resolution imaging.

Fostering effective and sustainable scientific collaboration and knowledge exchange: a workshop-based approach to establish a national ecological observatory network (NEON) domain-specific user group.

The decision to establish a network of researchers centers on identifying shared research goals. Ecologically specific regions, such as the USA's National Ecological Observatory Network's (NEON's) eco-climatic domains, are ideal locations by which to assemble researchers with a diverse range of expertise but focused on the same set of ecological challenges. The recently established Great Lakes User Group (GLUG) is NEON's first domain specific ensemble of researchers, whose goal is to address scientific and technical issues specific to the Great Lakes Domain 5 (D05) by using NEON data to enable advancement of ecosystem science. Here, we report on GLUG's kick off workshop, which comprised lightning talks, keynote presentations, breakout brainstorming sessions and field site visits. Together, these activities created an environment to foster and strengthen GLUG and NEON user engagement. The tangible outcomes of the workshop exceeded initial expectations and include plans for (i) two journal articles (in addition to this one), (ii) two potential funding proposals, (iii) an assignable assets request and (iv) development of classroom activities using NEON datasets. The success of this 2.5-day event was due to a combination of factors, including establishment of clear objectives, adopting engaging activities and providing opportunities for active participation and inclusive collaboration with diverse participants. Given the success of this approach we encourage others, wanting to organize similar groups of researchers, to adopt the workshop framework presented here which will strengthen existing collaborations and foster new ones, together with raising greater awareness and promotion of use of NEON datasets. Establishing domain specific user groups will help bridge the scale gap between site level data collection and addressing regional and larger ecological challenges.

The emerging therapies are reshaping the first-line treatment for advanced hepatocellular carcinoma: a systematic review and network meta-analysis.

Background: Given the superior performance of various therapies over sorafenib in advanced hepatocellular carcinoma (HCC) and the absence of direct comparisons, it is crucial to explore the efficacy of these treatments in phase III randomized clinical trials. Objectives: The goal is to identify which patients are most likely to benefit significantly from these emerging therapies, contributing to more personalized and informed clinical decision-making. Design: Systematic review and network meta-analysis. Data sources and methods: PubMed, Embase, ClinicalTrials.gov, and international conference databases have been searched from 1 January 2010 to 1 December 2023. Results: After screening, 17 phase III trials encompassing 18 treatments were included. In the whole-population network meta-analysis, the newly first-line tremelimumab plus durvalumab (Tre + Du) was found to be comparable with atezolizumab plus bevacizumab (Atezo + Beva) in providing the best overall survival (OS) benefit [hazard ratio (HR) 1.35, 95% confidence interval (CI): 0.93-1.92]. Concerning OS benefits, sintilimab plus bevacizumab biosimilar (Sint + Beva), camrelizumab plus rivoceranib (Camre + Rivo), and lenvatinib plus pembrolizumab (Lenva + Pemb) appear to exhibit similar effects to Tre + Du and Atezo + Beva. In the context of progression-free survival, Atezo + Beva seemed to outperform Tre + Du (HR: 0.66 CI: 0.49-0.87), while the effects are comparable to Sint + Beva, Camre + Rivo, and Lenva + Pemb. Upon comparison between Asia-Pacific and non-Asia-Pacific cohorts, as well as between hepatitis B virus (HBV)-infected and non-HBV-infected populations, immune checkpoint inhibitor (ICI)-based treatments seemed to exhibit heightened efficacy in the Asia-Pacific group and among individuals with HBV infection. However, combined ICI-based therapies did not show more effectiveness than molecular-targeted drugs in patients without macrovascular invasion and/or extrahepatic spread. As for grades 3-5 adverse events, combined therapies showed comparable safety to sorafenib and lenvatinib. Conclusion: Compared with sorafenib and lenvatinib, combination therapies based on ICIs significantly improved the prognosis of advanced HCC and demonstrated similar safety. At the same time, the optimal treatment approach should be tailored to individual patient characteristics, such as etiology, tumor staging, and serum alpha-fetoprotein levels. With lower incidence rates of treatment-related adverse events and non-inferior efficacy compared to sorafenib, ICI monotherapies should be prioritized as a first-line treatment approach for patients who are not suitable candidates for ICI-combined therapies. Trial registration: PROSPERO, CRD42022288172.

Lay summary/Key points The efficiency of various systemic therapies in advanced HCC patients with specific characteristics remains to be explored. This study revealed that the efficacy of ICI combined therapies is influenced by factors such as tumor staging, etiology, patient demographics, and more. Additionally, ICI monotherapies should be prioritized as a first-line treatment approach for patients who are not suitable candidates for ICI combined therapies. Complementing to recent guidelines, this study indicated that several critical factors needed to be took into consideration for patients with advanced HCC.

Submerged Culture of Edible and Medicinal Mushroom Mycelia and Their Applications in Food Products: A Review.

Edible mushrooms have rich nutrition (e.g., proteins, dietary fibers, polysaccharides) and they can be potential sources of important ingredients in food processing. However, the cultivation of mushroom fruiting bodies needs a relatively long time, and they can be easily polluted during the growth process. At the same time, a lot of labor and larger planting areas are also required. As we all know, submerged fermentation is a good way to produce edible mushroom mycelia with less environmental pollution and small footprint, which are also rich in nutrition and bioactive components that are used as dietary supplements or health care products in the food industry. Therefore, it can be considered that the replacement of edible mushroom fruiting bodies with edible mushroom mycelia produced through submerged fermentation has great application potential in food production. At present, most of the research about edible mushroom mycelia focuses on the production of bioactive metabolites in fermentation liquid, but there are few reports that concentrate on their applications in food. This paper reviews the research progress of submerged culture of edible mushroom mycelia and their applications in food products.

Improvement of Formability in Parallel Double-Branched Tube Hydroforming Combined with Pre-Forming and Crushing Processes.

In hydroforming of parallel double-branch tubes, the material entering the branch zone is obstructed by material accumulation in the main tubes and corners, which decreases the branch height. A tube hydroforming approach is combined with pre-forming and crushing (THPC) to mitigate this problem. A larger diameter tube blank is flattened for pre-forming and then subjected to radial compression for crushing. In the next step, hydroforming forms the parallel double-branch tubes. Experiments and numerical simulations are then carried out to analyze the effect of traditional tube hydroforming (TTH) and the proposed THPC process on the formability of parallel double-branch tubes. The results show that for tubes obtained via THPC, the tube burst pressure increases by 27.5% and the branch height increases 2.37-fold compared to TTH. Additionally, the flattening, pre-forming, and crushing stages cause work hardening of the tube when using the TPHC process. Flattened tubes undergo radial compression to improve the material flowing into the branch tube. The formability of parallel double-branched tubes can be improved by using the TPHC process. Consequently, tube hydroforming, combined with pre-forming and crushing, has been confirmed as a feasible forming process for fabricating parallel double-branch tubes.

Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk: A meta-analysis.

Nitrosamines are a class of carcinogens which have been detected widely in food, water, some pharmaceuticals as well as tobacco. The objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents, and assessing the health risks of tobacco nitrosamines exposure to Chinese smokers. We searched the publications in English from "Web of Science" and those in Chinese from the "China National Knowledge Infrastructure" in 2022 and collected 151 literatures with valid information. The content of main nitrosamines in tobacco, including 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB), total tobacco-specific nitrosamines (TSNA), and N-nitrosodimethylamine (NDMA) were summarized. The information of daily tobacco consumption of smokers in 30 provinces of China was also collected. Then, the intakes of NNN, NNK, NAT, NAB, TSNAs, and NDMA via tobacco smoke were estimated as 1534 ng/day, 591 ng/day, 685 ng/day, 81 ng/day, 2543 ng/day, and 484 ng/day by adult smokers in 30 provinces, respectively. The cancer risk (CR) values for NNN and NNK inhalation intake were further calculated as 1.44 × 10-5 and 1.95 × 10-4. The CR value for NDMA intake via tobacco smoke (inhalation: 1.66 × 10-4) indicates that NDMA is similarly dangerous in tobacco smoke when compared with the TSNAs. In China, the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following: smoke (3.75 × 10-4) > food (1.74 × 10-4) > drinking water (1.38 × 10-5). Smokers in China averagely suffer 200% of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

Research progress on carotenoid production by Rhodosporidium toruloides.

Carotenoids are natural lipophilic pigments, which have been proven to provide significant health benefits to humans, relying on their capacity to efficiently scavenge singlet oxygen and peroxyl radicals as antioxidants. Strains belonging to the genus Rhodosporidium represent a heterogeneous group known for a number of phenotypic traits including accumulation of carotenoids and lipids and tolerance to heavy metals and oxidative stress. As a representative of these yeasts, Rhodosporidium toruloides naturally produces carotenoids with high antioxidant activity and grows on a wide variety of carbon sources. As a result, R. toruloides is a promising host for the efficient production of more value-added lipophilic compound carotenoids, e.g., torulene and torularhodin. This review provides a comprehensive summary of the research progress on carotenoid biosynthesis in R. toruloides, focusing on the understanding of biosynthetic pathways and the regulation of key enzymes and genes involved in the process. Moreover, the relationship between the accumulation of carotenoids and lipid biosynthesis, as well as the stress from diverse abiotic factors, has also been discussed for the first time. Finally, several feasible strategies have been proposed to promote carotenoid production by R. toruloides. It is possible that R. toruloides may become a critical strain in the production of carotenoids or high-value terpenoids by genetic technologies and optimal fermentation processes. KEY POINTS: • Biosynthetic pathway and its regulation of carotenoids in Rhodosporidium toruloides were concluded • Stimulation of abiotic factors for carotenoid biosynthesis in R. toruloides was summarized • Feasible strategies for increasing carotenoid production by R. toruloides were proposed.

Adaptive changes in tumor cells in response to reductive stress.

Reductive stress is characterized by an excess of cellular electron donors and can be linked with various human pathologies including cancer. We developed melanoma cell lines resistant to reductive stress agents: rotenone (ROTR), n-acetyl-L-cysteine, (NACR), or dithiothreitol (DTTR). Resistant cells divided more rapidly and had intracellular homeostatic redox-couple ratios that were shifted towards the reduced state. Resistance caused alterations in general cell morphology, but only ROTR cells had significant changes in mitochondrial morphology with higher numbers that were more isolated, fragmented and swollen, with greater membrane depolarization and decreased numbers of networks. These changes were accompanied by lower basal oxygen consumption and maximal respiration rates. Whole cell flux analyses and mitochondrial function assays showed that NACR and DTTR preferentially utilized tricarboxylic acid (TCA) cycle intermediates, while ROTR used ketone body substrates such as D, L-ß-hydroxybutyric acid. NACR and DTTR cells had constitutively decreased levels of reactive oxygen species (ROS), although this was accompanied by activation of nuclear factor erythroid 2-related factor 2 (Nrf2), with concomitant increased expression of the downstream gene products such as glutathione S-transferase P (GSTP). Further adaptations included enhanced expression of endoplasmic reticulum proteins controlling the unfolded protein response (UPR). Although expression patterns of these UPR proteins were distinct between the resistant cells, a trend implied that resistance to reductive stress is accompanied by a constitutively increased UPR phenotype in each line. Overall, tumor cells, although tolerant of oxidative stress, can adapt their energy and survival mechanisms in lethal reductive stress conditions.

Ganoderma Fusions with High Yield of Ergothioneine and Comparative Analysis of Its Genomics.

Ergothioneine (EGT), an exceptional antioxidant found ubiquitously across diverse living organisms, plays a pivotal role in various vital physiological regulatory functions. Its principal natural sources are mushrooms and animal liver tissues. Ganoderma spp., a traditional Chinese food and medicinal mushroom, boasts high concentrations of EGT. To advance the development of novel Ganoderma spp. strains with enhanced EGT yields, we employed an efficient Ganoderma spp. protoplasmic fusion system. Through molecular and biological characterization, we successfully generated seven novel fusion strains. Notably, fusion strain RS7 demonstrated a remarkable increase in mycelial EGT production (12.70 ± 1.85 mg/L), surpassing the parental strains FQ16 and FQ23 by 34.23% and 39.10%, respectively. Furthermore, in the context of the fruiting body, fusion strain RS11 displayed a notable 53.58% enhancement in EGT production (11.24 ± 1.96 mg/L) compared to its parental strains. Genomic analysis of the RS7, the strain with the highest levels of mycelial EGT production, revealed mutations in the gene EVM0005141 associated with EGT metabolism. These mutations led to a reduction in non-productive shunts, subsequently redirecting more substrate towards the EGT synthesis pathway. This redirection significantly boosted EGT production in the RS7 strain. The insights gained from this study provide valuable guidance for the commercial-scale production of EGT and the selective breeding of Ganoderma spp. strains.