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Thioredoxin pathway regulated live-cell synthesis of CdSe quantum dots in Saccharomyces cerevisiae

Science China Chemistry 2024年第11期67卷 3851-3860页

作者： Xu Li Cai-Qin Wu jia-wei tu Juan Kong Ling-Ling Yang Zhi-Xiong Xie Dai-Wen Pang College of Chemistry and Molecular Sciences The Institute for Advanced StudiesCollege of Life SciencesWuhan UniversityWuhan 430072China Research Center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Currently, the application of synthetic biology to artificially manipulate and utilize organisms for the synthesis of desired products such as nanomaterials with excellent fluorescence properties is attracting considerable attention. However, it is still difficult to obtain designed products efficiently due to insufficient knowledge of the biosynthetic mechanisms. The thioredoxin(TRX) and glutathione(GSH) pathways are generally conserved thiol-reductase systems that protect organisms from oxidative stress and are involved in selenium(Se) metabolism. In this study, we revealed the pivotal role of cytoplasmic TRX pathway in regulating the metabolism of Na_(2)SeO_(3) during the live-cell synthesis of cadmium-selenium quantum dots(Cd Se QDs) in Saccharomyces cerevisiae by regulating the expression level of genes related to TRX pathway and measuring the intracellular content of selenocysteine(Se Cys). The determination of Se Cys metabolism in yeast with GSH pathway-related genes deleted demonstrated that the TRX pathway played a more significant role in Se Cys metabolism than GSH pathway. A 6.4-fold enhancement in the synthetic yield of Cd Se QDs was achieved through the overexpression of TRX pathway-related genes,improvement of synthetic procedure, and supplementation of GSH based on the understanding of biological *** the mechanism of CdSe QDs live-cell synthesis facilitates the precise manipulation of biological processes for the synthesis of inorganic nanomaterials.

关键词： thioredoxin glutathione quantum dot live-cell synthesis selenium metabolism Saccharomyces cerevisiae

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Designer cell-self-implemented labeling of microvesicles in situ with the intracellular-synthesized quantum dots

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Science China Chemistry 2020年第4期63卷 448-453页

作者： Ling-Hong Xiong jia-wei tu Ya-Nan Zhang Ling-Ling Yang Ran Cui Zhi-Ling Zhang Dai-Wen Pang College of Chemistry and Molecular Sciences State Key Laboratory of VirologyInstitute for Advanced Studiesand Wuhan Institute of BiotechnologyWuhan UniversityWuhan 430072China State Key Laboratory of Medicinal Chemical Biology Tianjin Key Laboratoryof Biosensing and Molecular RecognitionResearch Center for Analytical Sciencesand College of ChemistryNankai UniversityTianjin 300071China

Cell-derived microvesicles(MVs) are secreted from almost all kinds of mammalian cells into the extracellular space, and play crucial roles in intercellular communication and transporting biomolecules between cells. However, there is a great challenge for visualizing and monitoring of MVs’ bio-behaviors due to the limitations of existing labeling methods. Herein, we report the first paradigm of designer cell-self-implemented labeling of MVs secreted from living mammalian MCF-7 cells in situ using the intracellular-synthesized fluorescent quantum dots(QDs) during the formation of MVs. By elaborately coupling intracellular biochemical reactions and metabolism pathways, the MCF-7 cells can be illuminated brightly by intracellular-biosynthesized fluorescent CdSe QDs. Simultaneously, intracellular-synthesized QDs can be in situ encapsulated by the secreted MVs budding from the plasma membrane of the fluorescing cells to label the MVs with an efficiency of up to 89.9%. The whole labeling process skillfully combines designer precise cell-tuned intricate synthesis of CdSe QDs with mild in-situ labeling via cell-selfimplementation just after feeding the cell with suitable chemicals, which is structure-or function-nondestructive and much more straightforward and milder than those by chemical conjugation or indirect encapsulation with conventional fluorogenic labels.

关键词： in situ labeling live cell synthesis cell-derived microvesicles quantum dot cell-self-implementation

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Intracellular redox potential-driven live-cell synthesis of CdSe quantum dots in Staphylococcus aureus

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Science China Chemistry 2024年第3期67卷 990-999页

作者： Cai-Qin Wu An-An Liu Xu Li jia-wei tu Juan Kong Ling-Ling Yang jian-Hong jia Chuan Wang Bin Hu Zhi-Xiong Xie Dai-Wen Pang The Institute for Advanced Studies College of Chemistry and Molecular SciencesCollege of Life SciencesHubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhan 430072China Research Center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Biosynthesized semiconductor quantum dots(QDs) have bright fluorescence,adjustable particle sizes,and environmental friendliness,endowing them with convenience and potential for biological *** to the unclear mechanism of the cellular environment on the live-cell synthesis of QDs,it is still difficult to regulate their optical ***,the critical role of the intracellular redox environment in regulating the fluorescence properties of biosynthesized CdSe QDs in Staphylococcus aureus(***) has been *** glutathione peroxidase(GPx) activity directly affects the intracellular H_(2)O_(2) produced in the SeO_(3)^(2-) reduction,which further manipulates the glutathione redox cycle to determine the content of low-valence *** a result,the fluorescence intensity of the synthesized CdSe QDs increases by 60% in the GPx overexpressed *** cellular redox potential that is controlled by the GSH redox cycle provides the driving force for the reduction of SeO_(3)^(2-),facilitating the synthesis of CdSe QDs in *** *** proposed mechanism of the cellular redox state provides a new perspective for regulating the synthesis of semiconductor nanomaterials in live cells.

关键词： redox H_(2)O_(2) peroxidase quantum dot Staphylococcus aureus

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Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

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Neural Regeneration Research 2025年第6期20卷 1721-1734页

作者： Xirong Xu Shoumin Xuan Shuai Chen Dan Liu Qian Xiao Jie tu Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases Shenzhen-Hong Kong Institute of Brain ScienceShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina CAS Key Laboratory of Brain Connectome and Manipulation Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina Guangdong Provincial Key Laboratory of Brain Connectome and Behavior the Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina University of Chinese of Academy of Sciences BeijingChina Faculty of Life and Health Sciences Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with ***, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal *** knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was ob

关键词： anxiety astrocytes basolateral amygdala behavior dihydrokainic acid excitatory amino acid transporter 2 fiber photometry glutamate LDN-212320 transporter

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Focusing phenomenon and near-trapped modes of SH waves

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Earthquake Engineering and Engineering Vibration 2016年第3期15卷 477-486页

作者： Jeng-Tzong Chen jia-wei Lee Ya-Ching tu Department of Harbor and River Engineering Taiwan Ocean University Department of Mechanical and Mechatronic Engineering Taiwan Ocean University

In this study, the null-field boundary integral equation method （BIEM） and the image method are used to solve the SH wave scattering problem containing semi-circular canyons and circular tunnels. To fully utilize the analytical property of Circular geometry, the polar coordinates are used to expand the closed-form fundamental solution to the degenerate kernel, and the Fourier series is also introduced to represent the boundary density. By collocating boundary points to match boundary condition on the boundary, a linear algebraic system is constructed. The unknown coefficients in the algebraic system can be easily determined. In this way, a semi-analytical approach is developed. Following the experience of near-trapped modes in water wave problems of the full plane, the focusing phenomenon and near-trapped modes for the SH wave problem of the half-plane are solved, since the two problems obey the same mathematical model. In this study, it is found that the SH wave problem containing two semi-circular canyons and a circular tunnel has the near-trapped mode and the focusing phenomenon for a special incident angle and wavenumber. In this situation, the amplification factor for the amplitude of displacement is over 300.

关键词： SH wave null-field boundary integral equation method degenerate kernel focusing, near-trapped mode

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Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

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Journal of Energy Chemistry 2025年第01期 77-86页

作者： Jinzhi jia Jinhua Zhang Kailu Guo Lanyue Zhang Gening Du Hao You Junfeng Huang Mudong tu Hua Li Yong Peng wei Dou Cailing Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

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Fractional vegetation cover estimation in heterogeneous areas by combining a radiative transfer model and a dynamic vegetation model

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International Journal of Digital Earth 2020年第4期13卷 487-503页

作者： Yixuan tu Kun jia Shunlin Liang Xiangqin wei Yunjun Yao Xiaotong Zhang State Key Laboratory of Remote Sensing Science Faculty of Geographical ScienceBeijing Normal UniversityBeijingPeople’s Republic of China Beijing Engineering Research Center for Global Land Remote Sensing Products Institute of Remote Sensing Science and EngineeringFaculty of Geographical ScienceBeijing Normal UniversityBeijingPeople’s Republic of China Department of Geographical Sciences University of MarylandCollege ParkMDUSA d Institute of Remote Sensing and Digital Earth Chinese Academy of SciencesBeijingPeople’s Republic of China

A fractional vegetation cover(FVC)estimation method incorporating a vegetation growth model and a radiative transfer model was previously developed,which was suitable for FVC estimation in homogeneous areas because the finer-resolution pixels corresponding to one coarseresolution FVC pixel were all assumed to have the same vegetation growth ***,this assumption does not hold over heterogeneous areas,meaning that the method cannot be applied to large ***,this study proposes a finer spatial resolution FVC estimation method applicable to heterogeneous areas using Landsat 8 Operational Land Imager reflectance data and Global LAnd Surface Satellite(GLASS)FVC *** FVC product was first decomposed according to the normalized difference vegetation index from the Landsat 8 OLI ***,independent dynamic vegetation models were built for each finer-resolution ***,the dynamic vegetation model and a radiative transfer model were combined to estimate FVC at the Landsat 8 *** results indicated that the proposed method(R^(2)=0.7757,RMSE=0.0881)performed better than either the previous method(R^(2)=0.7038,RMSE=0.1125)or a commonly used method involving look-up table inversions of the PROSAIL model(R^(2)=0.7457,RMSE=0.1249).

关键词： Dynamic Bayesian network fractional vegetation cover global land surface satellite radiative transfer model dynamic vegetation model

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Study on Porous Silicon with P-N Junction Sensor for Humidity Measurement

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稀有金属材料与工程 2006年第A03期35卷 372-374页

作者： Chuzhe tu Zhenhong jia College of Information science＆ engineering Xinjiang University Urumqi 830046 China

Porous materials used for humidity sensing have been *** this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are *** is made by electro-chemical anodic etched method from silicon wafers with P-N *** porous structure is verified by scanning electronic micrograph. Experiments also show that PNJPS has high sensitivity,short response time (less than 30 seconds),and long-term stability.

关键词： porous silicon humidity sensing characteristics P-N junctions

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Extramedullary plasmacytoma with the uvula as first affected site:A case report

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World Journal of Clinical Oncology 2025年第1期16卷 53-58页

作者： Jing Yang Hui Peng Sheng-Ke tu Min Li Kui Song Department of Hematology The First Affiliated Hospital of Jishou UniversityJishou 416000Hunan ProvinceChina Department of Pharmacy The First Affiliated Hospital of Jishou UniversityJishou 416000Hunan ProvinceChina

BACKGROUND Extramedullary plasmacytoma(EMP)represents one of the rarer forms of plasma cell malignancies,capable of impacting a variety of tissues and organs throughout the *** majority of EMP cases are predominantly found in the head and neck region,especially within the laryngopharynx,as well as in the gastrointestinal *** there have been documented instances of oropharyngeal involvement in EMP cases in the academic literature,it is important to note that EMP specifically affecting the uvula is exceedingly ***,it is noteworthy that over 60% of epithelial carcinomas in the upper respiratory tract and oropharynx tend to metastasize to the cervical lymph nodes,indicating a propensity for regional spread in these types of *** this context,we present a rare case of extramedullary plasmacytoma where the uvula served as the initially affected *** case emphasizes the need for heightened awareness among clinicians regarding such unusual comorbidities,as early recognition and diagnosis can significantly influence patient management and treatment *** addition,a review of the relevant literature is included to further educate and inform healthcare professionals about this rare presentation,ultimately aiming to enhance clinical understanding and improve patient care in similar *** SUMMARY A 51-year-old man was admitted to our hospital because of a slowly enlarging neck mass.A physical examination revealed a palpable left lymph node,and magnetic resonance imaging(MRI)of the oropharynx and the neck showed a soft tissue mass in the oropharynx and enlargement of multiple lymph nodes in the *** soft tissue mass was diagnosed as plasmacytoma by immunohistochemical *** immunoglobulins and bone marrow biopsy showed normal ***,we diagnosed that as EMP of the *** four cycles of adjuvant chemotherapy dominated by bortezomib,MRI reexamination showed a significant reduction of the mass

关键词： Extramedullary plasmacytoma Plasmacytoma Uvula Multiple myeloma Case report

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Strongly adaptive online learning over partial intervals

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Science China(Information Sciences) 2022年第10期65卷 107-121页

作者： Yuanyu WAN wei-wei tu Lijun ZHANG National Key Laboratory for Novel Software Technology Nanjing University 4Paradigm Inc.

To cope with changing environments, strongly adaptive algorithms that almost enjoy the optimal performance on every time interval have been proposed for online learning. However, the best regret bound of existing algorithms on each time interval with length τ is O((τlogT)1/2), and their complexities are increasing with a factor of O(log T), where T is the time horizon. In real-world applications, T could go to infinity,which means that even these logarithmic factors are unacceptable. In this paper, we propose to remove the logarithmic factors of existing algorithms by utilizing prior information of environments. Specifically, we assume a lower bound τ1and an upper bound τ2on how long the environment changes are given, and only focus on the performance over time intervals with length in [τ1, τ2]. Then, we propose a new algorithm with a refined set of intervals that can reduce the complexity and a simple weighting method that can cooperate with our interval set. Theoretical analysis reveals that the regret bound of our algorithm on any focused interval is optimal up to a constant factor. Both the regret bound and the computational cost per iteration are independent of T. Experimental results show that our algorithm outperforms the state-of-the-art algorithm.

关键词： onling learning strongly adaptive changing environments weighing method regret bound

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