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Abstract Perineural invasion (PNI) is a new approach of cervical cancer invasion and metastasis, involving the cross-talk between tumor and nerve. However, the initiating signals and cellular interaction mechanisms of PNI remain largely elusive. The nerve-sparing radical hysterectomy (NSRH) proposed to improve postoperative quality of life is only applicable to cervical cancer patients without PNI. Therefore, it is important to elucidate the underlying mechanisms initiating PNI, and suggest the effective biomarkers to predict PNI before NSRH surgery. Here, we found that PNI is the characteristic of advanced cervical cancer, and Schwann cells were the antecedent cells that initiating PNI. Further, neuropeptide neuromedin B (NMB) produced by cervical cancer cells was determined to induce PNI by reprogramming Schwann cells, including driving their morphological and transcriptional changes, promoting their proliferation and migration, and initiating PNI by secreting CCL2 and directing axon regeneration. Mechanistically, cervical cancer cells-produced NMB activated its receptor NMBR in Schwann cells, and opened the T-type calcium channels to stimulate Ca2+ influx through PKA signaling, which could be blocked by the inhibitor. Clinically, combined examination of serum NMB and CCL2 levels was suggested to effectively predict PNI in cervical cancer patients. Our data demonstrate that cervical cancer-produced NMB initiates the reprograming of Schwann cells, which then direct axon regeneration, thus causing PNI onset. The elevated serum NMB and CCL2 levels may be useful for the decision-making to nerve sparing during hysterectomy surgery of cervical cancer patients.

Abstract Interleukin-6 (IL-6) is a pleiotropic cytokine and exerts its complex biological functions mainly through three different signal modes, called cis-, trans-, and cluster signaling. When IL-6 binds to its membrane or soluble receptors, the co-receptor gp130 is activated to initiate downstream signaling and induce the expression of target genes. In the liver, IL-6 can perform its anti-inflammatory activities to promote hepatocyte reprogramming and liver regeneration. On the contrary, IL-6 also exerts the pro-inflammatory functions to induce liver aging, fibrosis, steatosis, and carcinogenesis. However, understanding the roles and underlying mechanisms of IL-6 in liver physiological and pathological processes is still an ongoing process. So far, therapeutic agents against IL‑6, IL‑6 receptor (IL‑6R), IL-6-sIL-6R complex, or IL-6 downstream signal transducers have been developed, and determined to be effective in the intervention of inflammatory diseases and cancers. In this review, we summarized and highlighted the understanding of the double-edged effects of IL-6 in liver homeostasis, aging, inflammation, and chronic diseases, for better shifting the “negative” functions of IL-6 to the “beneficial” actions, and further discussed the potential therapeutic effects of targeting IL-6 signaling in the clinics.

Abstract Background Liver ischemia/reperfusion (I/R) injury is usually caused by hepatic inflow occlusion during liver surgery, and is frequently observed during war wounds and trauma. Hepatocyte ferroptosis plays a critical role in liver I/R injury, however, it remains unclear whether this process is controlled or regulated by members of the DEAD/DExH-box helicase (DDX/DHX) family. Methods The expression of DDX/DHX family members during liver I/R injury was screened using transcriptome analysis. Hepatocyte-specific Dhx58 knockout mice were constructed, and a partial liver I/R operation was performed. Single-cell RNA sequencing (scRNA-seq) in the liver post I/R suggested enhanced ferroptosis by Dhx58 hep−/− . The mRNAs and proteins associated with DExH-box helicase 58 (DHX58) were screened using RNA immunoprecipitation-sequencing (RIP-seq) and IP-mass spectrometry (IP-MS). Results Excessive production of reactive oxygen species (ROS) decreased the expression of the IFN-stimulated gene Dhx58 in hepatocytes and promoted hepatic ferroptosis, while treatment using IFN-α increased DHX58 expression and prevented ferroptosis during liver I/R injury. Mechanistically, DHX58 with RNA-binding activity constitutively associates with the mRNA of glutathione peroxidase 4 (GPX4), a central ferroptosis suppressor, and recruits the m6A reader YT521-B homology domain containing 2 (YTHDC2) to promote the translation of Gpx4 mRNA in an m6A-dependent manner, thus enhancing GPX4 protein levels and preventing hepatic ferroptosis. Conclusions This study provides mechanistic evidence that IFN-α stimulates DHX58 to promote the translation of m6A-modified Gpx4 mRNA, suggesting the potential clinical application of IFN-α in the prevention of hepatic ferroptosis during liver I/R injury.

Summary: Ubiquitination is essential for the proteasomal turnover of IRF3, the central factor mediating the antiviral innate immune response. However, the spatiotemporal regulation of IRF3 ubiquitination for the precise activation and timely resolution of innate immunity remains unclear. Here, we identified BRCA1-associated protein-1 (BAP1) and ubiquitin-protein ligase E3C (UBE3C) as the key deubiquitinase and ubiquitinase for temporal control of IRF3 stability during viral infection. In the early stage, BAP1 dominates and removes K48-linked ubiquitination of IRF3 in the nucleus, preventing its proteasomal degradation and facilitating efficient interferon (IFN)-β production. In the late stage, E3 ligase UBE3C, induced by IFN-β, specifically mediates IRF3 ubiquitination and promotes its proteasomal degradation. Overall, the sequential interactions with BAP1 and UBE3C govern IRF3 stability during innate response, ensuring effective viral clearance and inflammation resolution. Our findings provide insights into the temporal control of innate signaling and suggest potential interventions in viral infection.

Abstract Background Genome-scale screening can be applied to efficiently mine for unknown genes with phenotypes of interest or special functions. It is also useful to identify new targets for engineering desirable properties of cell factories. Results Here, we designed a new approach for genome-scale transcription activation using non-homologous end joining (NHEJ)-mediated integration in Yarrowia lipolytica. We utilized this approach to screen for genes that, upon activation, confer phenotypes including improved acetic acid tolerance and xylose metabolism. The candidates were validated using gene overexpression, and functional changes including improved growth performance under multiple stressors and activated pentose metabolism were identified. Conclusions This study provides a simple and effective approach to randomly activate endogenous genes and mine for key targets associated with phenotypes of interest. The specific gene targets identified here will be useful for cell factory construction and biorefining lignocellulose.

Abstract Excitons, bound electron–hole pairs, in two-dimensional hybrid organic inorganic perovskites (2D HOIPs) are capable of forming hybrid light-matter states known as exciton-polaritons (E–Ps) when the excitonic medium is confined in an optical cavity. In the case of 2D HOIPs, they can self-hybridize into E–Ps at specific thicknesses of the HOIP crystals that form a resonant optical cavity with the excitons. However, the fundamental properties of these self-hybridized E–Ps in 2D HOIPs, including their role in ultrafast energy and/or charge transfer at interfaces, remain unclear. Here, we demonstrate that >0.5 µm thick 2D HOIP crystals on Au substrates are capable of supporting multiple-orders of self-hybridized E–P modes. These E–Ps have high Q factors (>100) and modulate the optical dispersion for the crystal to enhance sub-gap absorption and emission. Through varying excitation energy and ultrafast measurements, we also confirm energy transfer from higher energy E–Ps to lower energy E–Ps. Finally, we also demonstrate that E–Ps are capable of charge transport and transfer at interfaces. Our findings provide new insights into charge and energy transfer in E–Ps opening new opportunities towards their manipulation for polaritonic devices.

Wild giant pandas, an endangered species exclusive to China, are a focus of conservation efforts. The behavior of giant pandas reflects their health conditions and activity capabilities, which play an important role in formulating and implementing conservation measures. Researching and developing efficient behavior recognition methods based on deep learning can significantly advance the study of wild giant panda behavior. This study introduces, for the first time, a transformer-based behavior recognition method termed PandaFormer, which employs time-spatial attention to analyze behavioral temporal patterns and estimate activity spaces. The method integrates advanced techniques such as cross-fusion recurrent time encoding and transformer modules, which handle both temporal dynamics and spatial relationships within panda behavior videos. First, we design cross-fusion recurrent time encoding to represent the occurrence time of behaviors effectively. By leveraging the multimodal processing capability of the transformer, we input time and video tokens into the transformer module to explore the relation between behavior and occurrence time. Second, we introduce relative temporal weights between video frames to enable the model to learn sequential relationships. Finally, considering the fixed position of the camera during recording, we propose a spatial attention mechanism based on the estimation of the panda's activity area. To validate the effectiveness of the model, a video dataset of wild giant pandas, encompassing five typical behaviors, was constructed. The proposed method is evaluated on this video-level annotated dataset. It achieves a Top-1 accuracy of 92.25 % and a mean class precision of 91.19 %, surpassing state-of-the-art behavior recognition algorithms by a large margin. Furthermore, the ablation experiments validate the effectiveness of the proposed temporal and spatial attention mechanisms. In conclusion, the proposed method offers an effective way of studying panda behavior and holds potential for application to other wildlife species.

Summary: Scent marking sites served as a primary means of chemical communication for giant pandas, enabling intraspecific communication. We integrated metabolomics and high-throughput sequencing techniques to examine the non-targeted metabolome and microbial community structure of scent marking sites and feces in the field. Integrative analysis revealed a more comprehensive array of chemical compounds compared to previous investigations, including ketones, acids, heterocycles, alcohols, and aldehydes. Notably, specific compounds such as 2-decenal, (E)-, octanal, decanal, L-α-terpineol, vanillin, and nonanal emerged as potential key players in scent signaling. Intriguingly, our study of the microbial domain identified dominant bacterial species from the Actinobacteria, Bacteroidetes, and Proteobacteria phyla, likely orchestrating metabolic processes at scent marking sites. Comparative analyses showed, for the first time, that feces do not share the same functions as scent markers, indicating distinct functional roles. This research deepens scientific understanding of chemical communication in wild pandas.

To enhance the mechanical properties and cost-effectiveness of conventional polyvinyl alcohol fiber reinforced strain hardening cementitious composite (PVA-SHCC), a modified version called multiscale hybrid fiber reinforced SHCC (MsHySHCC) was developed. This new composite incorporates a combination of steel fiber, PVA fiber and calcium carbonate (CaCO3) whisker. Uniaxial direct tensile behaviors (stress-strain relationship, tensile strength, tensile deformation capacity and tensile toughness) of designed MsHySHCCs were investigated and evaluated. The results show that the PVA fibers dominate the ductile behavior and the steel fibers and CaCO3 whiskers effectively affect the strength of MsHySHCCs. The PVA fibers can be partially replaced by CaCO3 whisker and steel fiber, along with an increase in tensile strength and ductility of designed composites. The findings suggest that the configuration of MsHySHCC proves to be a viable approach in simultaneously enhancing the strength and ductility of PVA-SHCC. A semi-theoretical prediction model for tensile constitutive relationship was derived. The comparison of the theoretical results with the experimental data shows that this semi-theoretical model is applicable for determining the tensile constitutive relationship of PVA-SHCCs and MsHySHCCs.

Abstract Succinic acid (SA) is an important C4-dicarboxylic acid. Microbial production of SA at low pH results in low purification costs and hence good overall process economics. However, redox imbalances limited SA biosynthesis from glucose via the reductive tricarboxylic acid (TCA) cycle in yeast. Here, we engineer the strictly aerobic yeast Yarrowia lipolytica for efficient SA production without pH control. Introduction of the reductive TCA cycle into the cytosol of a succinate dehydrogenase-disrupted yeast strain causes arrested cell growth. Although adaptive laboratory evolution restores cell growth, limited NADH supply restricts SA production. Reconfiguration of the reductive SA biosynthesis pathway in the mitochondria through coupling the oxidative and reductive TCA cycle for NADH regeneration results in improved SA production. In pilot-scale fermentation, the engineered strain produces 111.9 g/L SA with a yield of 0.79 g/g glucose within 62 h. This study paves the way for industrial production of biobased SA.

Abstract Background While representing a model bacterium and one of the most used chassis in biomanufacturing, performance of Escherichia coli is often limited by severe stresses. A super-robust E. coli chassis that could efficiently tolerant multiple severe stresses is thus highly desirable. Sterols represent a featured composition that distinguishes eukaryotes from bacteria and all archaea, and play a critical role in maintaining the membrane integrity of eukaryotes. All sterols found in nature are directly synthesized from (S)-2,3-oxidosqualene. However, in E. coli, (S)-2,3-oxidosqualene is not present. Results In this study, we sought to introduce (S)-2,3-oxidosqualene into E. coli. By mining and recruiting heterologous enzymes and activation of endogenous pathway, the ability of E. coli to synthesize (S)-2,3-oxidosqualene was demonstrated. Further analysis revealed that this non-native chemical confers E. coli with a robust and stable cell membrane, consistent with a figurative analogy of wearing an “Iron Man’s armor”-like suit. The obtained Iron Man E. coli (IME) exhibited improved tolerance to multiple severe stresses, including high temperature, low pH, high salt, high sugar and reactive oxygen species (ROS). In particular, the IME strain shifted its optimal growth temperature from 37 °C to 42–45 °C, which represents the most heat-resistant E. coli to the best of our knowledge. Intriguingly, this non-native chemical also improved E. coli tolerance to a variety of toxic feedstocks, inhibitory products, as well as elevated synthetic capacities of inhibitory chemicals (e.g., 3-hydroxypropionate and fatty acids) due to improved products tolerance. More importantly, the IME strain was effectively inhibited by the most commonly used antibiotics and showed no undesirable drug resistance. Conclusions Introduction of the non-native (S)-2,3-oxidosqualene membrane lipid enabled E. coli to improve tolerance to various stresses. This study demonstrated the effectiveness of introducing eukaryotes-featured compound into bacteria for enhancing overall tolerance and chemical production.

2′-Fucosyllactose (2′-FL) has great application value as a nutritional component and the whole cell biosynthesis of 2′-FL has become the focus of current research. Yarrowia lipolytica has great potential in oligosaccharide synthesis and large-scale fermentation. In this study, systematic engineering of Y. lipolytica for efficient 2′-FL production was performed. By fusing different protein tags, the synthesis of 2′-FL was optimized and the ubiquitin tag was demonstrated to be the best choice to increase the 2′-FL production. By iterative integration of the related genes, increasing the precursor supply, and promoting NADPH regeneration, the 2′-FL synthesis was further improved. The final 2′-FL titer, 41.10 g/L, was obtained in the strain F5-1. Our work reports the highest 2′-FL production in Y. lipolytica, and demonstrates that Y. lipolytica is an efficient microbial chassis for the synthesis of oligosaccharides.

Non-contact temperature sensors utilising the fluorescence intensity ratio and the unique up-conversion (UC) luminescence of rare-earth ions have numerous benefits; however, their operational temperature range has remained limited. In this study, NaLuF4:Yb3+/Ho3+ samples were prepared by the hydrothermal method. The samples exhibited exceptional UC luminescence properties at low temperatures. The intensity of the green emission (with peak wavelengths of 540 and 546 nm) gradually decreased with increasing temperature, and the green emissions showed a unique change at low temperatures. In addition, we studied the dependence of the UC luminescence intensity on the excitation power and the variation in the decay lifetime with temperature. The experiments revealed excellent luminous performance and significantly enhanced sensitivity at low temperatures; the maximum absolute sensitivity Sa and relative sensitivity Sr of the 540 and 546 nm thermally coupled energy levels were 1.02% and 0.55% K−1, respectively. The potential temperature sensing properties of Yb3+/Ho3+-co-doped NaLuF4 makes it suitable for temperature sensing applications at temperatures as low as 30 K. This study offers a novel approach for the advancement of temperature sensing technology at low temperatures.

Abstract Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis remain to be fully investigated. Immunoresponsive gene 1 (IRG1) and its enzymatic metabolite itaconate are known to suppress inflammation in myeloid cells, and its expression in liver parenchymal hepatocytes is currently determined. However, the potential roles of IRG1 in hepatocarcinogenesis are still unknown. Here, using the diethylnitrosamine (DEN)-induced hepatocarcinogenesis mouse model, we found that IRG1 expression in hepatocytes was markedly induced upon DEN administration. The DEN-induced IRG1 was then determined to promote the intrinsic mitochondrial apoptosis of hepatocytes and liver damage, thus enhancing the subsequent hepatocarcinogenesis. Mechanistically, the mitochondrial IRG1 could associate and trap anti-apoptotic MCL-1 to inhibit the interaction between MCL-1 and pro-apoptotic Bim, thus promoting Bim activation and downstream Bax mitochondrial translocation, and then releasing cytochrome c and initiating apoptosis. Thus, the inducible mitochondrial IRG1 promotes hepatocyte apoptosis and the following hepatocarcinogenesis, which provides mechanistic insight and a potential target for preventing liver injury and HCC.

In this study, we investigate micrometer-sized NaYF4 crystals double-doped with Yb3+/Er3+ lanthanide ions, designed for temperature-sensing applications. In contrast to previous studies, which focused predominantly on the high-temperature regime, our investigation spans a comprehensive range of both high and ultralow temperatures. We explore the relationship between temperature and the upconversion luminescence (UCL) spectra in both frequency and time domains. Our findings highlight the strong dependence of these spectral characteristics of lanthanide-doped NaYF4 crystals on temperature. Furthermore, we introduce a dual-mode luminescence temperature measurement technique, leveraging the upconversion emission intensity ratio for both green and red emissions. This study also examines the correlation between temperature sensing, energy level disparities, and thermal coupling in Er3+ ions across various temperature scales. Our research contributes to advancing the understanding and application of lanthanide-doped materials, setting a foundation for future innovations in temperature sensing across diverse fields.

Abstract Soil and water assessment tool (SWAT) model was used to calculate the runoff, nitrogen and phosphorus emissions in the Dagu River Basin from 2002 to 2012 and provided preliminary suggestions on environmental protection measures. Calibration on hydrological watershed parameters was obtained from data obtained from multiple representative stations. Cluster analysis was used to group all stations, and the parameters of different representative stations were applied to the entire geographical area to reflect the hydrological conditions of the basin. Additionally, the spatiotemporal changes and pollution source characteristics of nitrogen and phosphorus were analyzed. Anthropogenic sources—chemical fertilizer loss and livestock breeding—accounted for 49.9–29.6% of total nitrogen (TN) and 41.4% and 40.3% of total phosphorus (TP), respectively. Non-point sources accounted for 85.8% of the TN and 89.4% of the TP. Six landscape management practices were set up to evaluate the reduction effect on non-point source pollution loads, and comprehensive measures were proposed to reduce TN (TP) by ~ 70%. According to water quality model, the response relationship between river control and nutrient distribution in Jiaozhou Bay is calculated. Based on the findings, we propose an optimal control scheme for non-point source pollution in the Dagu River Basin and other similar basins.

By improving both effective-index (EI) matching and leakage-factor (LF) matching at multiple wavelengths, a method to achieve a wideband-efficient uniform subwavelength grating coupler (SWGC) has been theoretically demonstrated. First, the root-mean-square-error between the grating EI and ideal EI (RMSE-EI) and root-mean-square-error between the grating LF and ideal LF (RMSE-LF) are adopted to weigh EI and LF matching at multiple wavelengths. It is found that when the RMSE-EI decreases and keeping RMSE-LF almost constant, the coupling bandwidth of the uniform SWGC could be substantially increased. Moreover, when RMSE-LF of the uniform SWGC decreases while RMSE-EI remains almost constant, the overall integral coupling efficiency (ICE) within the band from 1525 nm to 1575 nm is enhanced. Furthermore, by simultaneously enhancing both EI matching and LF matching at three wavelengths, a 1-dB bandwidth of 53.7 nm and ICE of 22.31 is obtained in an optimized SOI uniform SWGC. Using the proposed multi-wavelength optimizing methodology, even more efficient wideband couplers could be expected by adopting more optimization accounting for more structural parameters in the future.

Abstract Background Hepatocarcinogenesis is driven by necroinflammation or metabolic disorders, and the underlying mechanisms remain largely elusive. We previously found that retinoic acid-inducible gene-I (RIG-I), a sensor for recognizing RNA virus in innate immune cells, is mainly expressed by parenchymal hepatocytes in the liver. However, its roles in hepatocarcinogenesis are unknown, which is intensively investigated in this study. Methods DEN-induced necroinflammation-driven hepatocarcinogenesis and STAM NASH-hepatocarcinogenesis were carried out in hepatocyte-specific RIG-I knockout mice. The post-translational modification of RIG-I was determined by mass spectrometry, and specific antibodies against methylated lysine sites and the RIG-I lysine mutant mice were constructed to identify the functions of RIG-I methylation. Results We interestingly found that DEN-induced hepatocarcinogenesis was enhanced, while NASH-induced hepatocarcinogenesis was suppressed by hepatocyte-specific RIG-I deficiency. Further, IL-6 decreased RIG-I expression in HCC progenitor cells (HcPCs), which then viciously promoted IL-6 effector signaling and drove HcPCs to fully established HCC. RIG-I expression was increased by HFD, which then enhanced cholesterol synthesis and steatosis, and the in-turn NASH and NASH-induced hepatocarcinogenesis. Mechanistically, RIG-I was constitutively mono-methylated at K18 and K146, and demethylase JMJD4-mediated RIG-I demethylation suppressed IL-6-STAT3 signaling. The constitutive methylated RIG-I associated with AMPKα to inhibit HMGCR phosphorylation, thus promoting HMGCR enzymatic activity and cholesterol synthesis. Clinically, RIG-I was decreased in human hepatic precancerous dysplastic nodules while increased in NAFLD livers, which were in accordance with the data in mouse models. Conclusions Decreased RIG-I in HcPCs promotes necroinflammation-induced hepatocarcinogenesis, while increased constitutive methylated RIG-I enhances steatosis and NASH-induced hepatocarcinogenesis. JMJD4-demethylated RIG-I prevents both necroinflammation and NASH-induced hepatocarcinogenesis, which provides mechanistic insight and potential target for preventing HCC.

Periodontitis is a chronic inflammatory disease associated with a dysbiotic bacterial biofilm in the subgingival environment that may disturb the balance between the oral microbiome and its host. The inability of the immune system to eliminate inflammation may result in the progressive destruction of tooth-support tissues. Macrophages are crucial cellular components of the innate immune system and play important roles in diverse physiological and pathological processes. In response to periodontitis-associated bacterial communities, macrophages contribute to inflammation and restoration of tissue homeostasis through pattern recognition receptor-induced signaling cascades; therefore, targeting macrophages can be a feasible strategy to treat patients with periodontitis. Although recent studies indicate that macrophages have a spectrum of activation states, ranging from pro-inflammatory to anti-inflammatory, the regulatory mechanism of the macrophage response to dysbiosis in a tissue-specific manner remains largely unclear. Herein, we attempt to summarize the potential role of macrophage activation in the progression of periodontitis, as well as its relevance to future approaches in the treatment of periodontitis.

Abstract Background β-Farnesene is a sesquiterpene with versatile industrial applications. The production of β-farnesene from waste lipid feedstock is an attractive method for sustainable production and recycling waste oil. Yarrowia lipolytica is an unconventional oleaginous yeast, which can use lipid feedstock and has great potential to synthesize acetyl-CoA-derived chemicals. Results In this study, we engineered Y. lipolytica to produce β-farnesene from lipid feedstock. To direct the flux of acetyl-CoA, which is generated from lipid β-oxidation, to β-farnesene synthesis, the mevalonate synthesis pathway was compartmentalized into peroxisomes. β-Farnesene production was then engineered by the protein engineering of β-farnesene synthase and pathway engineering. The regulation of lipid metabolism by enhancing β-oxidation and eliminating intracellular lipid synthesis was further performed to improve the β-farnesene synthesis. As a result, the final β-farnesene production with bio-engineering reached 35.2 g/L and 31.9 g/L using oleic acid and waste cooking oil, respectively, which are the highest β-farnesene titers reported in Y. lipolytica. Conclusions This study demonstrates that engineered Y. lipolytica could realize the sustainable production of value-added acetyl-CoA-derived chemicals from waste lipid feedstock.

Summary With the rapid development of synthetic biology, the oleaginous yeast Yarrowia lipolytica has become an attractive microorganism for chemical production. To better optimize and reroute metabolic pathways, we have expanded the CRISPR‐based gene expression toolkit of Y. lipolytica. By sorting the integration sites associated with high expression, new neutral integration sites associated with high expression and high integration efficiency were identified. Diverse genetic components, including promoters and terminators, were also characterized to expand the expression range. We found that in addition to promoters, the newly characterized terminators exhibited large variations in gene expression. These genetic components and integration sites were then used to regulate genes involved in the lycopene biosynthesis pathway, and different levels of lycopene production were achieved. The CRISPR‐based gene expression toolkit developed in this study will facilitate the genetic engineering of Y. lipolytica.

To accurately unwrap the high-order orbital angular momentum (OAM) for multiplexed vortex beams is a challenge. In this work, over ±160 order OAM topological charges have been unwrapped in multiplexed optical links. Optical imaging based discrepancy identification enables the multiplexed OAM modes separating in physics, and the intelligent pattern recognition further promotes its unwrapping in numerical domain. Particularly, the combination of annular phase grating and auxiliary beams features compound spiral stripes, which paves the way for optical intensity recognition with low-complexity and high-commonality. Moreover, the spiral direction characterizes the symbol of the OAM states, which dramatically broadens the amount of multiplexed links. Here, optical separating means assisted by intelligent pattern recognition opens up a new route to high-speed and large-capacity optical communication, which may shed new light on 6G application.

Summary Engineered Saccharomyces cerevisiae strains are good cell factories, and developing additional genetic manipulation tools will accelerate construction of metabolically engineered strains. Highly repetitive rDNA sequence is one of two main sites typically used for multicopy integration of genes. Here, we developed a simple and high‐efficiency strategy for rDNA‐mediated multicopy gene integration based on the dynamic balance of rDNA in S. cerevisiae. rDNA copy number was decreased by pre‐treatment with hydroxyurea (HU). Then, heterologous genes were integrated into the rDNA sequence. The copy number of the integrated heterologous genes increased along with restoration of the copy number of rDNA. Our results demonstrated that HU pre‐treatment doubled the number of integrated gene copies; moreover, compared with removing HU stress during transformation, removing HU stress after selection of transformants had a higher probability of resulting in transformants with high‐copy integrated genes. Finally, we integrated 18.0 copies of the xylose isomerase gene into the S. cerevisiae genome in a single step. This novel rDNA‐mediated multicopy genome integration strategy provides a convenient and efficient tool for further metabolic engineering of S. cerevisiae.

Summary: Acetyl-coenzyme A (Acetyl-CoA) and malonyl-coenzyme A (malonyl-CoA) are important precursors for producing various chemicals, and their availability affects the production of their downstream chemicals. Storage carbohydrates are considered important carbon and energy reservoirs. Herein, we find that regulating the storage carbohydrate synthesis improves metabolic fluxes toward malonyl-CoA. Interestingly, not only directly decreasing storage carbohydrate accumulation improved malonyl-CoA availability but also increasing the storage carbohydrate by UGP1 overexpression enables an even higher production of acetyl-CoA- and malonyl-CoA-derived chemicals. We find that Ugp1p overexpression dynamically regulates the carbon flux to storage carbohydrate synthesis. In early exponential phases, Ugp1 overexpression causes more storage carbohydrate accumulation, while the carbon flux is then redirected toward acetyl-CoA and malonyl-CoA in later phases, thereby contributing to the synthesis of their derived products. Our study demonstrates the importance of storage carbohydrates rearrangement for the availability of acetyl-CoA and malonyl-CoA and therefore will facilitate the synthesis of their derived chemicals.

Early classification of brain tumors from magnetic resonance imaging (MRI) plays an important role in the diagnosis of such diseases. There are many diagnostic imaging methods used to identify tumors in the brain. MRI is commonly used for such tasks because of its unmatched image quality. The relevance of artificial intelligence (AI) in the form of deep learning (DL) has revolutionized new methods of automated medical image diagnosis. This study aimed to develop a robust and efficient method based on transfer learning technique for classifying brain tumors using MRI. In this article, the popular deep learning architectures are utilized to develop brain tumor diagnostic system. The pre-trained models such as Xception, NasNet Large, DenseNet121 and InceptionResNetV2 are used to extract the deep features from brain MRI. The experiment was performed using two benchmark datasets that are openly accessible from the web. Images from the dataset were first cropped, preprocessed, and augmented for accurate and fast training. Deep transfer learning models are trained and tested on a brain MRI dataset using three different optimization algorithms (ADAM, SGD, and RMSprop). The performance of the transfer learning models is evaluated using performance metrics such as accuracy, sensitivity, precision, specificity and F1-score. From the experimental results, our proposed CNN model based on the Xception architecture using ADAM optimizer is better than the other three proposed models. The Xception model achieved accuracy, sensitivity, precision specificity, and F1-score values of 99.67%, 99.68%, 99.68%, 99.66%, and 99.68% on the MRI-large dataset, and 91.94%, 96.55%, 87.50%, 87.88%, and 91.80% on the MRI-small dataset, respectively. The proposed method is superior to the existing literature, indicating that it can be used to quickly and accurately classify brain tumors.

Acoustic droplet vaporization (ADV) plays an important role in focused ultrasound theranostics. Better understanding of the relationship between the ultrasound parameters and the ADV nucleation could provide an on-demand regulation and enhancement of ADV for improved treatment outcome. In this work, ADV nucleation was performed in a dual-frequency focused ultrasound configuration that consisted of a continuous low-frequency ultrasound and a short high-frequency pulse. The combination was modelled to investigate the effects of the driving frequency and acoustic power on the nucleation rate, efficiency, onset time, and dimensions of the nucleation region. The results showed that the inclusion of short pulsed high-frequency ultrasound significantly increased the nucleation rate with less energy, reduced the nucleation onset time, and changed the length–width ratio of the nucleation region, indicating the dual-frequency ultrasound mode yields an efficient enhancement of the ADV nucleation, compared to a single-frequency ultrasound mode. Furthermore, the acoustic and temperature fields varied independently with the dual-frequency ultrasound parameters. This facilitated the spatial and temporal control over the ADV nucleation, and opens the door to the possibility to realize on-demand regulation of the ADV occurrence in ultrasound theranostics. In addition, the improved energy efficacy that is obtained with the dual-frequency configuration lowered the requirements on hardware system, increasing its flexibility and could facilitate its implementation in practical applications.

Radiotherapy is one of the mainstream treatment modalities for several malignancies. However, radiation-induced injury to surrounding normal tissues limits its efficacy. The NLRP3 inflammasome is an essential mechanism of innate immunity that reacts to challenges from endogenous danger signals and pathological microbes. A growing body of evidence has demonstrated a key role of NLRP3 inflammasome in the pathogenesis of radiation-induced tissue injury. Despite accumulating evidence, the potential value of the NLRP3 inflammasome in the management of radiation-induced tissue injury is not adequately recognized. We conducted a literature review to characterize the relationship between NLRP3 inflammasome and radiation injury. By analyzing recent evidence, we identify NLRP3 inflammasome as one of the executioners of radiation-induced injury, since it responds to the challenges of radiation, induces cell pyroptosis and tissue dysfunction, and initiates non-resolving inflammation and fibrosis. Based on these concepts, we propose early intervention/prevention strategies targeting NLRP3 inflammasome in a radiation context, which may help resolve imperative clinical problems.

Summary Exorbitant outputs of waste xylose mother liquor (WXML) and corncob residue from commercial‐scale production of xylitol create environmental problems. To reduce the wastes, a Saccharomyces cerevisiae strain tolerant to WXML was conferred with abilities to express the genes of xylose reductase, a xylose‐specific transporter and enzymes of the pentose phosphate pathway. This strain showed a high capacity to produce xylitol from xylose in WXML with glucose as a co‐substrate. Additionally, a simultaneous saccharification and fermentation (SSF) process was designed to use corncob residues and cellulase instead of directly adding glucose as a co‐substrate. Xylitol titer and the productivity were, respectively, 91.0 g l‐1 and 1.26 ± 0.01 g l‐1 h‐1 using 20% WXML, 55 g DCW l‐1 delignified corncob residues and 11.8 FPU gcellulose‐1 cellulase at 35° during fermentation. This work demonstrates the promising strategy of SSF to exploit waste products to xylitol fermentation process.

Abstract Producing high value-added products from waste lipid feedstock by microbial cell factory has great advantages to minimize the pollution as well as improve the economic value of wasted oils and fats. Yarrowia lipolytica is a non-conventional oleaginous yeast and can grow on a variety of hydrophobic substrates. In this study, we explored its ability to synthesize α-farnesene, an important sesquiterpene, using lipid feedstock. Based on the α-farnesene production strain, we constructed previously, we identified that Erg12 was the key limiting factor to further increase the α-farnesene production. The α-farnesene production was improved by 35.8% through increasing the copy number of ERG12 and FSERG20 on oleic acid substrate. Expression of heterologous VHb further improved α-farnesene production by 12.7%. Combining metabolic engineering with the optimization of fermentation conditions, the α-farnesene titer and yield reached 10.2 g/L and 0.1 g/g oleic acid, respectively, in fed-batch cultivation. The α-farnesene synthesis ability on waste cooking oil and other edible oils were also explored. Compared with using glucose as carbon source, using lipid substrates obtained higher α-farnesene yield and titer, but lower by-products accumulation, demonstrating the advantage of Y. lipolytica to synthesize high value-added products using lipid feedstock.

Abstract Background Succinic acid (SA) is a crucial metabolic intermediate and platform chemical. Development of biobased processes to achieve sustainable SA production has attracted more and more attention in biotechnology industry. Yarrowia lipolytica has a strong tricarboxylic acid cycle and tolerates low pH conditions, thus making it a potential platform for SA production. However, its SA titers in glucose media remain low. Results In this study, we screened mitochondrial carriers and C4-dicarboxylic acid transporters to enhance SA secretion in Y. lipolytica. PGC62-SYF-Mae strain with efficient growth and SA production was constructed by optimizing SA biosynthetic pathways and expressing the transporter SpMae1. In fed-batch fermentation, this strain produced 101.4 g/L SA with a productivity of 0.70 g/L/h and a yield of 0.37 g/g glucose, which is the highest SA titer achieved using yeast, with glucose as the sole carbon resource. Conclusion Our results indicated that transporter engineering is a powerful strategy to achieve the efficient secretion of SA in Y. lipolytica, which will promote the industrial production of bio-based SA.

Peripheral nerve injury (PNI) is one of the most common concerns in trauma patients. Despite significant advances in repair surgeries, the outcome can still be unsatisfactory, resulting in morbidities such as loss of sensory or motor function and reduced quality of life. This highlights the need for more supportive strategies for nerve regrowth and adequate recovery. Multifunctional cytokine transforming growth factor-β (TGF-β) is essential for the development of the nervous system and is known for its neuroprotective functions. Accumulating evidence indicates its involvement in multiple cellular and molecular responses that are critical to peripheral nerve repair. Following PNI, TGF-β is released at the site of injury where it can initiate a series of phenotypic changes in Schwann cells (SCs), modulate immune cells, activate neuronal intrinsic growth capacity, and regulate blood nerve barrier (BNB) permeability, thus enhancing the regeneration of the nerves. Notably, TGF-β has already been applied experimentally in the treatment of PNI. These treatments with encouraging outcomes further demonstrate its regeneration-promoting capacity. Herein, we review the possible roles of TGF-β in peripheral nerve regeneration and discuss the underlying mechanisms, thus providing new cues for better treatment of PNI.

ABSTRACT Malonyl-coenzyme A (malonyl-CoA) is an important precursor for producing various chemicals, but its low availability limits the synthesis of downstream products in Saccharomyces cerevisiae. Owing to the complexity of metabolism, evolutionary engineering is required for developing strains with improved malonyl-CoA synthesis. Here, using the biosensor we constructed previously, a growth-based screening system that links the availability of malonyl-CoA with cell growth is developed. Coupling this system with in vivo continuous mutagenesis enabled rapid generation of genome-scale mutation library and screening strains with improved malonyl-CoA availability. The mutant strains are analyzed by whole-genome sequencing and transcriptome analysis. The omics analysis revealed that the carbon flux rearrangement to storage carbohydrate and amino acids synthesis affected malonyl-CoA metabolism. Through reverse engineering, new processes especially reduced lysine and arginine synthesis were found to improve malonyl-CoA synthesis. Our study provides a valuable complementary tool to other high-throughput screening method for mutant strains with improved metabolite synthesis and improves our understanding of the metabolic regulation of malonyl-CoA synthesis. IMPORTANCE Malonyl-CoA is a key precursor for the production a variety of value-added chemicals. Although rational engineering has been performed to improve the synthesis of malonyl-CoA in S. cerevisiae, due to the complexity of the metabolism there is a need for evolving strains and analyzing new mechanism to improve malonyl-CoA flux. Here, we developed a growth-based screening system that linked the availability of malonyl-CoA with cell growth and manipulated DNA replication for rapid in vivo mutagenesis. The combination of growth-based screening with in vivo mutagenesis enabled quick evolution of strains with improved malonyl-CoA availability. The whole-genome sequencing, transcriptome analysis of the mutated strains, together with reverse engineering, demonstrated weakening carbon flux to lysine and arginine synthesis and storage carbohydrate can contribute to malonyl-CoA synthesis. Our work provides a guideline in simultaneous strain screening and continuous evolution for improved metabolic intermediates and identified new targets for improving malonyl-CoA downstream product synthesis.

Abstract Valuable polysaccharides are usually produced using wild-type or metabolically-engineered host microbial strains through fermentation. These hosts act as cell factories that convert carbohydrates, such as monosaccharides or starch, into bioactive polysaccharides. It is desirable to develop effective in vivo high-throughput approaches to screen cells that display high-level synthesis of the desired polysaccharides. Uses of single or dual fluorophore labeling, fluorescence quenching, or biosensors are effective strategies for cell sorting of a library that can be applied during the domestication of industrial engineered strains and metabolic pathway optimization of polysaccharide synthesis in engineered cells. Meanwhile, high-throughput screening strategies using each individual whole cell as a sorting section are playing growing roles in the discovery and directed evolution of enzymes involved in polysaccharide biosynthesis, such as glycosyltransferases. These enzymes and their mutants are in high demand as tool catalysts for synthesis of saccharides in vitro and in vivo. This review provides an introduction to the methodologies of using cell-based high-throughput screening for desired polysaccharide-biosynthesizing cells, followed by a brief discussion of potential applications of these approaches in glycoengineering.

Summary Exploring the mechanisms of tolerance in microorganisms to vanillin, which is derived from lignin, will benefit the design of robust cell factories that produce biofuels and chemicals using lignocellulosic materials. Our objective was to identify the genes related to vanillin tolerance in Saccharomyces cerevisiae. We investigated the effects on vanillin tolerance of several genes that have site mutations in the highly vanillin‐tolerant strain EMV‐8 compared to its parental line NAN‐27. The results showed that overexpression of GCY1, a gene that encodes an aldo‐keto reductase that also has mRNA‐binding activity, YPR1, a paralog of GCY1 that encodes an aldo‐keto reductase, PEX5, a gene that encodes a peroxisomal membrane signal receptor and MBF1, a gene that encodes a multiprotein bridging factor increase the specific growth rates (μ) by 49%, 41%, 44% and 48 %, respectively, in medium containing 6 mmol l−1 vanillin. Among these gene products, Gcy1p and Ypr1p showed NADPH‐dependent and NAD(P)H‐dependent vanillin reductase activity, respectively. The reductase‐inactive mutant Gcy1pY56F also increased vanillin tolerance in S. cerevisiae, suggesting that other mechanisms exist. Although TRS85 and PEX5, genes for which the mRNAs are binding targets of Gcy1p, were shown to be related to vanillin tolerance, both the mRNA and protein levels of these genes were not changed by overexpression of GCY1. The relationship between the mRNA‐binding activity of Gcy1p and its positive effect on vanillin tolerance is still not clear. Finally, we found that the point mutation D112A in Mbf1p, which disrupts the binding of Mbf1p and the TATA element‐binding protein (TBP), did not decrease the positive effect of Mbf1p on vanillin tolerance. This indicates that the binding of Mbf1p and TBP is not necessary for the positive effect on vanillin tolerance mediated by Mbf1p. We have successfully identified new genes related to vanillin tolerance and provided novel targets that can be used to improve the vanillin tolerance of S. cerevisiae. Moreover, we have extended our understanding of the proteins encoded by these genes.

Abstract d-Glucaric acid (GA) is a value-added chemical produced from biomass, and has potential applications as a versatile platform chemical, food additive, metal sequestering agent, and therapeutic agent. Marketed GA is currently produced chemically, but increasing demand is driving the search for eco-friendlier and more efficient production approaches. Cell-based production of GA represents an alternative strategy for GA production. A series of synthetic pathways for GA have been ported into Escherichia coli, Saccharomyces cerevisiae and Pichia pastoris, respectively, and these engineered cells show the ability to synthesize GA de novo. Optimization of the GA metabolic pathways in host cells has leapt forward, and the titer and yield have increased rapidly. Meanwhile, cell-free multi-enzyme catalysis, in which the desired pathway is constructed in vitro from enzymes and cofactors involved in GA biosynthesis, has also realized efficient GA bioconversion. This review presents an overview of studies of the development of cell-based GA production, followed by a brief discussion of potential applications of biosensors that respond to GA in these biosynthesis routes.

Summary Saccharomyces cerevisiae is the preferred source of RNA derivatives, which are widely used as supplements for foods and pharmaceuticals. As the most abundant RNAs, the ribosomal RNAs (rRNAs) transcribed by RNA polymerase I (Pol I) have no 5′ caps, thus cannot be translated to proteins. To screen high‐nucleic‐acid content yeasts more efficiently, a cap‐independent protein expression system mediated by Pol I has been designed and established to monitor the regulatory changes of rRNA synthesis by observing the variation in the reporter genes expression. The elements including Pol I‐recognized rDNA promoter, the internal ribosome entry site from cricket paralytic virus which can recruit ribosomes internally, reporter genes (URA3 and yEGFP3), oligo‐dT and an rDNA terminator were ligated to a yeast episomal plasmid. This system based on the URA3 gene worked well by observing the growth phenotype and did not require the disruption of cap‐dependent initiation factors. The fluorescence intensity of strains expressing the yEGFP3 gene increased and drifted after mutagenesis. Combined with flow cytometry, cells with higher GFP level were sorted out. A strain showed 58% improvement in RNA content and exhibited no sequence alteration in the whole expression cassette introduced. This study provides a novel strategy for breeding high‐nucleic‐acid content yeasts.

Nano-copper has been increasingly employed in various products. In previous studies, we showed that nano-copper caused damage in the rat testis, but it remains unclear whether the toxic reaction can affect the reproductive function. In this study, following 28 d of exposure to nano-copper at a dose of 44, 88, and 175 mg/kg/day, there was a decrease in sperm quality, fructose content, and the secretion of sex hormones. Nano-copper also increased the level of oxidative stress, sperm malformation rate, and induced abnormal structural changes in testicular tissue. Moreover, Nano-copper upregulated the expression of apoptosis-related protein Bax and autophagy-related protein Beclin, and downregulated the expression of Bcl2 and p62. Furthermore, nano-copper (175 mg/kg) downregulated the protein expression of AMPK, p-AKT, mTOR, p-mTOR, p-4E-BP1, p70S6K, and p-p70S6K, and upregulated the protein expression of p-AMPK. Therefore, nano-copper induced damage in testicular tissues and spermatogenesis is highly related to cell apoptosis and autophagy by regulating the Akt/mTOR signaling pathway. In summary, excess exposure to nano-copper may induce testicular apoptosis and autophagy through AKT/mTOR signaling pathways, and damage the reproductive system in adult males, which is associated with oxidative stress in the testes.

Abstract Background With the development of engineering the microbial cell factories, biosensors have been used widely for regulation of cellular metabolism and high-throughput screening. However, most of the biosensors constructed in Saccharomyces cerevisiae are designed for transcriptional activation. Very few studies have dedicated to the development of genetic circuit for repressive regulation, which is also indispensable for the dynamic control of metabolism. Results In this study, through transcriptional deactivation design, we developed transcription-factor-based biosensors to allow repressive regulation in response to ligand. Using a malonyl-CoA sensing system as an example, the biosensor was constructed and systematically engineered to optimize the dynamic range by comparing transcriptional activity of the activators, evaluating the positions and numbers of the operators in the promoter and comparing the effects of different promoters. A biosensor with 82% repression ratio was obtained. Based on this design principle, another two biosensors, which sense acyl-CoA or xylose and downregulate gene expression, were also successfully constructed. Conclusions Our work systematically optimized the biosensors for repressive regulation in yeast for the first time. It provided useful framework to construct similar biosensors. Combining the widely reported biosensors for transcriptional activation with the biosensors developed here, it is now possible to construct biosensors with opposing transcriptional activities in yeast.

A novel method is proposed to select vortex beams carrying a specific orbital angular momentum (OAM) mode in turbulence heterodyne coherent mitigation (THCM) link. It is worth mentioning that intelligent phase matching (IPM) of the OAM beams based on the convolutional neural network (CNN) is the remarkable feature. Namely, CNN is particularly trained as the OAM modes classifier by the light intensity distribution patterns of different modes. The classifier actually acts as a mode detector to distinguish OAM modes by the map between the light intensity distribution and OAM mode, and then output mode information (MI). Specially, the phase matching technology is demonstrated to realize selection of specific OAM mode, where exploiting MI to select a specific phase mask is a characteristic of IPM. Subsequently, the phase mask is attached to the Gaussian beam to obtain the OAM beam carrying a special mode. Numerical results show a high IPM accuracy of 99% under medium strength atmospheric turbulence (AT).

Abstract Background Yarrowia lipolytica, a non-traditional oil yeast, has been widely used as a platform for lipid production. However, the production of other chemicals such as terpenoids in engineered Y. lipolytica is still low. α-Farnesene, a sesquiterpene, can be used in medicine, bioenergy and other fields, and has very high economic value. Here, we used α-farnesene as an example to explore the potential of Y. lipolytica for terpenoid production. Results We constructed libraries of strains overexpressing mevalonate pathway and α-farnesene synthase genes by non-homologous end-joining (NHEJ) mediated integration into the Y. lipolytica chromosome. First, a mevalonate overproduction strain was selected by overexpressing relevant genes and changing the cofactor specificity. Based on this strain, the downstream α-farnesene synthesis pathway was overexpressed by iterative integration. Culture conditions were also optimized. A strain that produced 25.55 g/L α-farnesene was obtained. This is the highest terpenoid titer reported in Y. lipolytica. Conclusions Yarrowia lipolytica is a potentially valuable species for terpenoid production, and NHEJ-mediated modular integration is effective for expression library construction and screening of high-producer strains.

NaYF4:Yb,Er@NaYF4 core–shell nanostructures were prepared to investigate their influence on upconversion (UC) luminescence. Tests revealed green radiation (4S3/2→4I15/2) and red radiation (4F9/2→4I15/2) first increased and then gradually decreased as Yb concentration increased in the NaYF4 shell. The strongest fluorescent radiation occurred at an Yb concentration of 5%. To investigate the complicated variation of luminescence, we designed a set of experiments to study the impact of Yb ion concentration on luminescence intensity, and we analyzed the corresponding enhancement mechanism. It is probable that the energy transfers between both Yb and Er ions and Yb and Yb ions are involved in the UC processes. The enhancement of hybrid nanostructures has huge potential in biological detection and solar cells.

Copper oxide nanosheet-loaded zeolite 10X nanocomposites (CuO-zeolite NCs) were successfully prepared by modifying zeolite 10X with CuSO4 aqueous solution. The formation of copper oxide nanosheets on the surface of zeolite 10X was observed by SEM. The thickness of CuO nanosheets was about 30–40 nm, and the width ranged from 200 nm to 300 nm. The XRD patterns showed that the new diffraction peaks of copper oxide appeared at 35.6° and 38.8°. According to the XPS results, the Cu 2p3/2 and Cu 2p1/2 peaks in CuO-zeolite NC were centered at 934.1 eV and 953.8 eV, which could be attributed to Cu(II). The EDS analysis revealed that the energy spectra of calcium gradually decreased as the copper ion concentration increased during the preparation of CuO-zeolite NCs. Meanwhile, the energy spectra of copper increased gradually, and the highest content of copper in CuO-zeolite NCs reached 22.35 wt.%. The BET surface areas of zeolite 10X and CuO-zeolite NCs were 587 and 363 m2/g, respectively, based on the N2 adsorption–desorption experiment. The antibacterial activities of CuO-zeolite NC were evaluated using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The antibacterial activities were related to both copper ion content in CuO-zeolite NCs and the particle size of copper oxide. The results showed that nano CuO-loaded zeolite 10X inhibited the activity of E. coli and S. aureus. CuO-zeolite NCs are expected to be further used in antifouling coating.

Abstract Background Enzymatic glycan synthesis has leapt forward in recent years and a number of glucuronosyltransferase (EC 2.4.1.17) have been identified and prepared, which provides a guide to an efficient approach to prepare glycans containing glucuronic acid (GlcA) residues. The uridine 5′-diphosphate (UDP) activated form, UDP-GlcA, is the monosaccharide donor for these glucuronidation reactions. Results To produce UDP-GlcA in a cost-effective way, an efficient three-step cascade route was developed using whole cells expressing hyperthermophilic enzymes to afford UDP-GlcA from starch. By coupling a coenzyme regeneration system with an appropriate expression level with UDP-glucose 6-dehydrogenase in a single strain, the cells were able to meet NAD+ requirements. Without addition of exogenous NAD+, the reaction produced 1.3 g L−1 UDP-GlcA, representing 100% and 46% conversion of UDP-Glc and UTP respectively. Finally, an anion exchange chromatography purification method was developed. UDP-GlcA was successfully obtained from the cascade system. The yield of UDP-GlcA during purification was about 92.0%. Conclusions This work built a de novo hyperthermophilic biosynthetic cascade into E. coli host cells, with the cells able to meet NAD+ cofactor requirements and act as microbial factories for UDP-GlcA synthesis, which opens a door to large-scale production of cheaper UDP-GlcA.

Template-free preparation of phillipsite as a novel K+ ion-exchanger was studied systematically by hydrothermal synthesis. The alkalinity, dosage of water glass, dosage of H2O, aging time, reaction temperature and time of hydrothermal synthesis were discussed in detail. The optimized material obtained about phillipsite through the synthesis and testing methods was performed. The K+ ion-exchange capacity and selectivity coefficient were tested. The molar composition for preparing high performance phillipsite obtained was 2K2O:18SiO2:Al2O3:510H2O by optimizing synthetic conditions. The K+ ion-exchange capacity of phillipsite was 57.3 mg/g in seawater. The K+ selectivity coefficient was 88.6 in an equimolar K+ and Na+ mixed solution. Phillipsite can selectively capture K+ over other ions, and therefore can be used for potassium extraction selectively from seawater. Phillipsite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The XRD pattern indicated that the synthetic zeolite was phillipsite. The phillipsite particles exhibited cross-like shape and the average particle size was about 2.5 μm. The synthetic phillipsite was mainly consisted of Si, Al, K and O elements.

Abstract Background Cell surface display of recombinant proteins has become a powerful tool for biotechnology and biomedical applications. As a model eukaryotic microorganism, Saccharomyces cerevisiae is an ideal candidate for surface display of heterologous proteins. However, the frequently used commercial yeast surface display system, the a-agglutinin anchor system, often results in low display efficiency. Results We initially reconstructed the a-agglutinin system by replacing two anchor proteins with one anchor protein. By directly fusing the target protein to the N-terminus of Aga1p and inserting a flexible linker, the display efficiency almost doubled, and the activity of reporter protein α-galactosidase increased by 39%. We also developed new surface display systems. Six glycosylphosphatidylinositol (GPI) anchored cell wall proteins were selected to construct the display systems. Among them, Dan4p and Sed1p showed higher display efficiency than the a-agglutinin anchor system. Linkers were also inserted to eliminate the effects of GPI fusion on the activity of the target protein. We further used the newly developed Aga1p, Dan4p systems and Sed1p system to display exoglucanase and a relatively large protein β-glucosidase, and found that Aga1p and Dan4p were more suitable for immobilizing large proteins. Conclusion Our study developed novel efficient yeast surface display systems, that will be attractive tools for biotechnological and biomedical applications

Tipping over avoidance is critical for the success of mobile manipulation, especially in the cases that the onboard manipulators or the mobile vehicles move rapidly. Due to strong dynamics coupling between the onboard manipulator and mobile vehicle, online evaluation of dynamic stability of mobile manipulators and generation of strategies for tip-over avoidance still remain challenging. This paper presents an improvement tip-over moment stability criterion dealing with wheel-terrain and vehicle-manipulator interaction and proposes a real-time tip-over avoidance algorithm to minimize the tip-over moment transfer through either adjusting the posture of the onboard manipulators or changing the running velocity of the vehicle. The simulations and experiments on a four-wheeled mobile manipulator validate the correctness and feasibility of the proposed method.

In this paper, a potassium chabazite (KCHA) zeolite membrane was prepared by coating KCHA zeolite on the surface of a porous alumina sphere. The performance of the KCHA zeolite membrane in extracting potassium from seawater and sea bittern at room temperature was studied in detail. The XRD results show that the prepared KCHA zeolite was a KCHA membrane. The EDS test indicated that the potassium content of the KCHA zeolite membrane reached a value of 18.33 wt.%. The morphology of the KCHA zeolite grown on the surface of the alumina sphere was similar to a sphere, and it had good symmetry. The potassium ion-exchange capacities of the KCHA zeolite membrane reached 32 mg/g in seawater and 77 mg/g in sea bittern at room temperature. Ion exchange between the ammonium ions and potassium ions in the KCHA zeolite membrane could be completed in a short time at room temperature. The KCHA zeolite membrane was proven to have good reusability in seawater and sea bittern. The selective ion-exchange mechanism of the KCHA zeolite membrane was controlled by a specific K+ ion memory.

Behavioral strategies used in scent communication can reflect the adaptive capacity of animals. Signal detection theory and the principle of least effort posit that scent marking must be efficient and energy maximizing. The giant panda (Ailuropoda melanoleuca) is a solitary species that relies heavily on scent communication. There have been few studies on scent communication of wild pandas due to their elusive nature. To deepen the understanding of scent communication in this vulnerable species, we analyze a novel dataset obtained from integrating transect surveys on scent marked trees with infrared camera trapping of wild giant pandas performing scent marking and scent investigation behaviors. We found that pandas selected large coniferous trees for scent marking relative to what was available. Of the scent marked trees, trees that were more frequently marked than others were those of preferred species, high elevation, at topographical aspects conducive for odor transmission, with larger surrounding trees, and at gentle slopes. There were three peaks in the frequency of scent communication throughout the year in October, December, and March, the third period overlapping with the mating season. Scent communication occurred mainly during daytime hours, peaking at dusk (18:00–20:00). Frequency of anogenital gland secretion (AGS) markings were significantly greater than urine markings during the mating season but not during other times of year, which may reflect their stronger capacity to convey estrus state of females during mating season. The findings enrich the understanding of giant panda scent communication, and more broadly emphasize the importance of considering scent communication for conservation efforts such as corridor design for this vulnerable species.