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Investigation of combined degrader for proton facility based on BDSIM/FLUKA Monte Carlo methods

Nuclear Science and Techniques 2022年第2期33卷 30-39页

作者： man-fen han Jin-Xing Zheng Xian-Hu Zeng Jun-Song Shen Hefei Institutes of Physical Science Chinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

The significant advantage of proton therapy over other particle-based techniques is in the unique physical characteristics of the Bragg *** can achieve a highly conformal dose distribution and maximize the probability of tumor control by varying the irradiation *** proton facilities use cyclotrons for fixed energy beam extraction and are equipped with degrader and collimator systems for energy modulation and emittance ***,interactions between charged particles and degrader materials inevitably cause beam loss and divergence and deteriorate beam performance,which present great challenges for downstream transport and clinical *** this work,we investigate a method of energy reduction by combining boron carbide and graphite in a degrader to obtain greater beam transmission at lower *** results demonstrate that the beam size and emittance at the exit of the combined degrader diverge less than those of multi-wedge one in the energy range of 70-160 ***,the transmission efficiency after the first dipole also shows improvements of 36.26%at 70 MeV and 70.55%at 110 *** a component with a high activity level,the degrader causes additional ambient radiation during *** induced radiation even remains several hours after system *** of material activation and induced radiation based on 1 h irradiation with a 400 nA beam current shows that the combined degrader has a definite advantage in shielding despite producing more secondary *** radioactivity and average ambient dose equivalent are reduced by 50%compared with the multiwedge degrader at the important cooling time of 1 *** 12 h and 24 h of cooling,the radiation levels of degraders decrease slightly due to the presence of long half-life residual *** average dose generated from the multi-wedge degrader is still 1.25 times higher than that of the combined one.

关键词： Proton therapy Degrader Boron carbide Transmission efficiency Radionuclide Ambient dose equivalent

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Brain region-specific roles of brain-derived neurotrophic factor in social stress-induced depressive-like behavior

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Neural Regeneration Research 2025年第1期20卷 159-173页

作者： man han Deyang Zeng Wei Tan Xingxing Chen Shuyuan Bai Qiong Wu Yushan Chen Zhen Wei Yufei Mei Yan Zeng Brain Science and Advanced Technology Institute Wuhan University of Science and TechnologyWuhanHubei ProvinceChina Geriatric Hospital Affiliated to Wuhan University of Science and Technology WuhanHubei ProvinceChina School of Public Health Wuhan University of Science and TechnologyWuhanHubei ProvinceChina

Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral *** studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and *** how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress *** this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of *** focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine *** determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic ***,BDNF might be a biological indicator regulating stress-related processes in various brain regions.

关键词： amygdala chronic mild stress chronic social defeat stress corticolimbic system depression hippocampus medial prefrontal cortex nucleus accumbens social stress models ventral tegmental area

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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

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FSD1 inhibits glioblastoma diffuse infiltration through restriction of HDAC6-mediated microtubule deacetylation

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Science China Life Sciences 2025年

作者： Dake Xiao Haowen Ran Lishu Chen Yuanyuan Li Yan Cai Songyang Zhang Qinghui Qi Huiran Wu Cheng Zhang Shuailiang Cao Lanjuan Mi Haohao Huang Ji Qi Qiuying han Haiqing Tu Huiyan Li Tao Zhou Fangye Li Ailing Li Jianghong man Nanhu Laboratory National Center of Biomedical Analysis School of Traditional Chinese Medicine Capital Medical University Department of Neurosurgery General Hospital of Central Theater Command of Chinese PLA School of Life and Health Sciences Huzhou College Department of Neurosurgery Beijing Fengtai Hospital Department of Neurosurgery First Medical Center of PLA General Hospital

The infiltration of glioblastoma multiforme(GBM) is predominantly characterized by diffuse spread, contributing significantly to therapy resistance and recurrence of GBM. In this study, we reveal that microtubule deacetylation, mediated through the downregulation of fibronectin type III and SPRY domain-containing 1(FSD1), plays a pivotal role in promoting GBM diffuse infiltration. FSD1 directly interacts with histone deacetylase 6(HDAC6) at its second catalytic domain, thereby impeding its deacetylase activity on α-tubulin and preventing microtubule deacetylation and depolymerization. This inhibitory interaction is disrupted upon phosphorylation of FSD1 at its Ser317 and Ser324 residues by activated CDK5, leading to FSD1 dissociation from microtubules and facilitating HDAC6-mediated α-tubulin deacetylation. Furthermore, increased expression of FSD1 or interference with FSD1 phosphorylation reduces microtubule deacetylation, suppresses invasion of GBM stem cells, and ultimately mitigates tumor infiltration in orthotopic GBM xenografts. Importantly, GBM tissues exhibit diminished levels of FSD1 expression, correlating with microtubule deacetylation and unfavorable clinical outcomes in GBM patients. These findings elucidate the mechanistic involvement of microtubule deacetylation in driving GBM cell invasion and offer potential avenues for managing GBM infiltration.

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Enhancement of Performance by Blade Optimization in Two-Stage Ring Blower

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Journal of Thermal Science 2010年第5期19卷 383-389页

作者： Choon-man Jang Gi-Young han Plant Research Division Korea Institute of Construction Technology dh-m co. ltd.626-5Bulmo-dongSeo-guIncheon404-270Korea

This paper describes the shape optimization of an impeller used for two-stage high pressure ring *** shape variables,which are used to define an impeller shape,are introduced to increase the blower *** pressure of a blower is selected as an object function,and the blade optimization is performed by a response surface ***-dimensional Navier-Stokes equations are introduced to analyze the internal flow of the blower and to find the value of object function for the training *** good agreement between experimental measurements and numerical simulation is obtained in the present *** the shape optimization,it is found that a hub height is effective to increase pressure in the ring *** pressure rise for the optimal two-stage ring blower is successfully increased up to 1.86% compared with that of reference at the design flow *** recirculation flow having low velocity is formed in both sides of the impeller outlet by different flow direction of the inlet and outlet of the *** flow field inside the ring blower is also analyzed and discussed.

关键词： Ring blower Blower performance Numerical simulation Blade optimization Response surface method

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Complexation Induced by Weak Interaction between DNA and PEO-b-P4VP below the CMC of the Polymer

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Chinese Journal of Polymer Science 2017年第1期35卷 46-53页

作者： han miao ya-fen wang hai-yan dong 陈道勇 The State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai 200433 China

The complexation between circular DNA and individual chains of PEO-b-P4VP with a relatively long PEO block and a short P4VP block is highly controllable when the interaction between DNA and the polymer is weak enough. When one circular DNA chain is taken into consideration, and the polymer concentration is far below its critical micelle concentration （CMC）, polymer chains are absorbed by DNA chain due to the interaction between the negatively charged DNA chain and the slightly positively charged P4VP block chains. After the adsorption/complexation, the DNA chain is converted into a nanoring （type 1）. In the nanoring, the DNA chain is sufficiently wrapped by the polymer and adopts a fully stretched conformation, so that the DNA compact ratio in the nanorings is close to 1. When the polymer concentration is close to but lower than the CMC, the free polymer chains in the solution are adsorbed not only by the DNA chain but also by the polymer chains that have already been adsorbed on the DNA chain. As a result, the circular DNA chain adsorbs more polymer chains, and thus the resultant nanoring （type 2） has a larger width. In the type 2 nanoring, the DNA chain is slightly compressed; the DNA compact ratio is only about 2-3. Therefore, complexation induced by the weak interaction between DNA and PEO-b-P4VP below the CMC can produce narrow-disperse and large nanorings with a perimeter of micrometers, which are difficult to prepare by existing methods.

关键词： Weak interaction DNA Individual polymer chains Block copolymer Critical micelle concentration

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Complementarity between micro-micro and micro-macro entanglement in a Bose–Einstein condensate with two Rydberg impurities

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Communications in Theoretical Physics 2020年第2期72卷 30-37页

作者： Zhen Li Yu han Le-man Kuang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

We theoretically study complementarity between micro-micro and micro-macro entanglement in a Bose–Einstein condensate with two Rydberg *** investigate quantum dynamics of micro-micro and micro-macro entanglement in the micro-macro *** is found that strong micro-macro entanglement between Rydberg impurities and the BEC can be generated by the use of initial micro-micro entanglement between two Rydberg impurities,which acts as the seed entanglement to create micro-macro *** demonstrate a curious complementarity relation between micro-micro and micro-macro entanglement,and find that the complementarity property can be sustained to some extent even though in the presence of the BEC decoherence.

关键词： complementarity micro-macro entanglement micro-micro entanglement a Bose-Einstein condensate Rydberg impurities

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Quantum dynamics of an impurity-doped Bose–Einstein condensate system

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Communications in Theoretical Physics 2020年第9期72卷 49-57页

作者： Yu han Zhen Li Le-man Kuang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

We study the quantum dynamics of an impurity-doped Bose–Einstein condensate(BEC) *** show how to generate the macroscopic quantum superposition states(MQSSs) of the BEC by the use of projective measurements on impurity atoms. It is found that the nonclassicality of MQSSs can be manipulated by changing the number of the impurities and their interaction with the BEC. It is shown that the BEC matter-wave field exhibits a collapse and revival phenomenon which reveals the quantum nature of the BEC matter-wave field. We investigate the micro-macro entanglement between the impurities and the BEC, and find enhancement of the micro-macro entanglement induced by the initial quantum coherence of the impurity atoms.

关键词： quantum dynamics an impurity-doped Bose–Einstein condensate macroscopic quantum superposition states quantum collapse and revival phenomenon micro-macro entanglement

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Review of energy consumption research for papermaking industry based on life cycle analysis

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1543-1553页

作者： Yi man Yulin han Jigeng Li Mengna Hong State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China Guangdong Provincial Key Lab of Green Chemical Product Technology South China University of TechnologyGuangzhou 510640China

Papermaking industry is a high-energy-consuming industry with long supply *** growth of paper product demand further intensifies the need of energy *** saving through the full supply chain has become a focal point for long-term sustainable development of the papermaking *** paper reviews the advances in life cycle analysis for the papermaking industry in recent *** the stages from the full supply chain are involved to give a panoramic overview of the papermaking *** object of this paper is to provide scientific basis to industry and decision-makers with profound understanding of the energy consumption and energy saving potential in a life cycle perspective.

关键词： Life cycle analysis Pulp Papermaking Energy consumption Energy saving

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Effects of rainfall regime and its character indices on soil loss at loessial hillslope with ephemeral gully

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Journal of Mountain Science 2017年第3期14卷 527-538页

作者： han Yong ZHENG fen-li XU Xi-meng State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Institute of Soil and Water ConservationChinese Academy of SciencesYangling 712100China University of Chinese Academy of Sciences Beijing 100049China Institute of Soil and Water Conservation NorthwestA&F UniversityYangling 712100China

Understanding the relationship between hillslope soil loss with ephemeral gully and rainfall regime is important for soil loss prediction and erosion control. Based on 12-year field observation data, this paper quantified the rainfall regime impacts on soil loss at loessial hillslope with ephemeral gully. According to three rainfall parameters including precipitation （P）, rainfall duration （t）, and maximum 30-minute rainfall intensity （I30）, 115 rainfall events were classified by using K-mean clustering method and Discriminant Analysis. The results showed that 115 rainfall events could be divided into three rainfall regimes. Rainfall Regime 1 （RR1） had large I30 values with low precipitation and short duration, while the three rainfall parameters of Rainfall Regime 3 （RR3） were inversely different compared with those of RR1; for Rainfall Regime 2 （RR2）, the precipitation, duration and Iso values were all between those of RR1 and RR3. Compared with RR2 and RR3, RR1 was the dominant rainfall regime for causing soil loss at the loessial hillslope with ephemeral gully, especially for causing extreme soil loss events. PI30 （Product of P and Izo） was selected as the key index of rainfall characteristics to fit soil loss equations. Two sets of linear regression equations between soil loss and Plzo with and without rainfall regime classification were fitted. Compared with the equation without rainfall regime classification, the cross validation results of the equations with rainfall regime classification was satisfactory. These results indicated that rainfall regime classification could not only depict rainfall characteristics precisely, but also improve soil loss equation prediction accuracy at loessial hillslope with ephemeral gully.

关键词： Rainfall regime Soil loss Rainfall character indices Loessial hillslope Ephemeral gully

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