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Experimental test of an extension of the Rosenzweig-Porter model to mixed integrable-chaotic systems experiencing time-reversal invariance violation
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作者 Xiaodong Zhang Jiongning Che Barbara Dietz 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第12期203-213,共11页
We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal(T)invariance.The measureme... We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal(T)invariance.The measurements are performed with a flat superconducting microwave resonator with circular shape in which chaoticity is induced by using either long antennas or inserting two circular disks into the cavity,and by magnetizing a ferrite disk placed at its center,which leads to violation of T invariance.We propose an extension of the Rosenzweig-Porter(RP)model,which interpolates between mixed regular-chaotic instead of integrable dynamics and fully chaotic dynamics with violated T-invariance,and derive a Wigner-surmise like analytical expression for the corresponding nearest-neighbor spacing distribution.We propose a procedure involving this result and those for the RP model to determine the size of T-invariance violation and chaoticity and validate it employing the experimental eigenfrequency spectra. 展开更多
关键词 wave chaos quantum chaos quantum billiards microwave billiards random matrix theory microwave experiments
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Genetics and genomics of prostate cancer 被引量:2
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作者 Michael Dean Hong LOU 《Asian Journal of Andrology》 SCIE CAS CSCD 2013年第3期309-313,共5页
Prostate cancer (PCa) is one of the most common malignancies in the world with over 890 000 cases and over 258 000 deaths worldwide each year. Nearly all mortalities from PCa are due to metastatic disease, typically... Prostate cancer (PCa) is one of the most common malignancies in the world with over 890 000 cases and over 258 000 deaths worldwide each year. Nearly all mortalities from PCa are due to metastatic disease, typically through tumors that evolve to be hormone-refractory or castrate-resistant. Despite intensive epidemiological study, there are few known environmental risk factors, and age and family history are the major determinants. However, there is extreme heterogeneity in PCa incidence worldwide, suggesting that major determining factors have not been described. Genome-wide association studies have been performed and a considerable number of significant, but low-risk loci have been identified. In addition, several groups have analyzed PCa by determination of genomic copy number, fusion gene generation and targeted resequencing of candidate genes, as well as exome and whole genome sequencing. These initial studies have examined both primary and metastatic tumors as well as murine xenografts and identified somatic alterations in TP53and other potential driver genes, and the disturbance of androgen response and cell cycle pathways. It is hoped that continued characterization of risk factors as well as gene mutation and misregulation in tumors will aid in understanding, diagnosing and better treating PCa. 展开更多
关键词 androgen receptor cancer progression chromatin remodeling METASTASIS prostate cancer (PCa) risk factor somaticmutation tumor heterogeneity
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Persistence of Pleural Effusions and Empyemas after Pneumococcal Conjugate Vaccine Implementation in Uruguay
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作者 Miguel Estevan Luis Martínez +1 位作者 Edith Arreisengor Maria Hortal 《World Journal of Vaccines》 2012年第4期179-181,共3页
In Uruguay a post pneumococcal conjugate vaccine implementation surveillance of hospitalized children with pneumonia showed an increase of complicated pneumonias, while uncomplicated pneumonias decreased. Out of 151 p... In Uruguay a post pneumococcal conjugate vaccine implementation surveillance of hospitalized children with pneumonia showed an increase of complicated pneumonias, while uncomplicated pneumonias decreased. Out of 151 pleural effusions, 62 were empyemas requiring drainage, the rest of cases were treated with antibiotics with a favorable outcome. Patient’s vaccinated status varied. Pneumococcal etiology was poorly documented. The few identified sero-types were 1 and 3, a fact that urges PCV13 use for their control. 展开更多
关键词 PNEUMONIA PLEURAL EFFUSION PNEUMOCOCCAL INFECTIONS Conjugate Vaccine
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Effect of 7 and 13-Valent Pneumococcal Conjugate Vaccines Different Number of Doses for Pneumonia Control in 2008 and 2010 Birth Cohort Children
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作者 María Hortal Miguel Meny +2 位作者 Miguel Estevan Fernando Arrieta Hilda Laurani 《World Journal of Vaccines》 2015年第1期37-42,共6页
The 7-valent pneumococcal conjugate vaccine (PCV) was introduced in Uruguay in March 2008. In April 2010, it was replaced by PCV13. Surveillance of both vaccines was performed on hospitalized children with consolidate... The 7-valent pneumococcal conjugate vaccine (PCV) was introduced in Uruguay in March 2008. In April 2010, it was replaced by PCV13. Surveillance of both vaccines was performed on hospitalized children with consolidated pneumonia. The effect of different number of vaccine doses was evaluated in 2008 and 2010 birth cohorts vaccinated with PCV7 and PCV13 respectively. The study aims to estimate the effects of PCV7 and PCV13 different number of doses on consolidated pneumonia, through the study of hospitalized children from 2008 and 2010 birth cohorts. Vaccination records of every child were available providing precise vaccination data;therefore a new approach was used to estimate PCVs effect. Incidence rate was calculated for each year of the study and for the different number of vaccine doses used each year. Exposure was calculated as person per year and rate ratio values determined the decrease of consolidated pneumonias. This decrease in percentage was estimated as the difference between the incidence with no vaccine and the incidence of every one of the doses. Incidence rate ratio revealed significant values for the three vaccine doses of PCVs for both cohorts. Upon comparing incidences, significant reduction percentages of consolidated pneumonia admissions were found. The reduction percentage of consolidated pneumonia for fully vaccinated (3 doses) patients was 69.3% and 84.6 % for PCV7 and PCV13, respectively. These results confirm that PCV7 and PCV13 are highly effective for reducing pediatric hospitalizations due to consolidated pneumonia, as reported by other national publications and demonstrated by international researchers. 展开更多
关键词 PNEUMOCOCCAL CONJUGATE Vaccine PNEUMONIA BIRTH COHORT Incidence Rate Dose SCHEDULE
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Thr231磷酸化对顺式和反式tau蛋白226-236多肽六聚体结构的影响
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作者 孟青青 曾鑫成 +3 位作者 苏玉红 白钢钢 Ruth Nussinov 马步勇 《阿尔茨海默病及相关病杂志》 2020年第4期258-266,共9页
目的:研究Thr231磷酸化对于顺-反式tau异构体构象以及聚集行为的影响,探讨可能的在阿尔茨海默病和相关疾病中的毒性关联。方法:采用副本交换分子动力学模拟分析Tau蛋白226-246多肽片段六聚体的相互作用和结构。采用NAMD和CHARMM36分子... 目的:研究Thr231磷酸化对于顺-反式tau异构体构象以及聚集行为的影响,探讨可能的在阿尔茨海默病和相关疾病中的毒性关联。方法:采用副本交换分子动力学模拟分析Tau蛋白226-246多肽片段六聚体的相互作用和结构。采用NAMD和CHARMM36分子力场的隐式溶剂化GBIS模型。使用了温度分布从300K到450K的56个模拟副本,每个模拟副本的模拟时间为200 ns,总模拟时间为11200 ns。结果:天然态时Thr231-Pro232是顺式和反式Tau226-236六聚体的相互作用中心,尽管顺式和反式tau多肽六聚体中肽链间有着不同的主链相互作用。反式比顺式tau多肽更易形成主链间氢键,226VAVVR231T部分在顺反式tau中均有4-10%的²结构,而反式tau多肽²结构略多。虽然反式tau蛋白多肽比顺式更为伸展末端距较长,但顺式和反式Tau226-236六聚体具有类似的表面积和回转半径。Thr231磷酸化完全破坏了顺式tau中主链间的氢键和²结构,反式Tau226-236六聚体中主链间的氢键和²结构也随Thr231磷酸化而减少,但影响较小。磷酸化Thr231在顺-反式Tau226-236六聚体中都易与Arg230形成盐桥。Thr231磷酸化促使顺式Tau226-236六聚体中VAVV部分有较大的疏水暴露面积,而这一作用在反式Tau226-236六聚体中较小。结论:Thr231磷酸化对顺式和反式Tau226-236六聚体结构有不同的影响,但是缺乏清晰的局部结构区别。Thr231磷酸化后六聚体中VAVV部分疏水暴露面积的差异和顺反式Tau226-236末端距的明显差别需要在全长Tau蛋白单体和寡聚体中进一步研究。 展开更多
关键词 阿尔茨海默病 TAU蛋白 淀粉样变性 磷酸化 分子动力学模拟
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Nontrivial coupling of light into a defect:the interplay of nonlinearity and topology 被引量:6
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作者 Shiqi Xia Dario Jukic +9 位作者 Nan Wang Daria Smirnova Lev Smirnov Liqin Tang Daohong Song Alexander Szameit Daniel Leykam Jingjun Xu Zhigang Chen Hrvoje Buljan 《Light(Science & Applications)》 SCIE EI CAS CSCD 2020年第1期646-655,共10页
The flourishing of topological photonics in the last decade was achieved mainly due to developments in linear topological photonic structures.However,when nonlinearity is introduced,many intriguing questions arise.For... The flourishing of topological photonics in the last decade was achieved mainly due to developments in linear topological photonic structures.However,when nonlinearity is introduced,many intriguing questions arise.For example,are there universal fingerprints of the underlying topology when modes are coupled by nonlinearity,and what can happen to topological invariants during nonlinear propagation?To explore these questions,we experimentally demonstrate nonlinearity-induced coupling of light into topologically protected edge states using a photonic platform and develop a general theoretical framework for interpreting the mode-coupling dynamics in nonlinear topological systems.Performed on laser-written photonic Su-Schrieffer-Heeger lattices,our experiments show the nonlinear coupling of light into a nontrivial edge or interface defect channel that is otherwise not permissible due to topological protection.Our theory explains all the observations well.Furthermore,we introduce the concepts of inherited and emergent nonlinear topological phenomena as well as a protocol capable of revealing the interplay of nonlinearity and topology.These concepts are applicable to other nonlinear topological systems,both in higher dimensions and beyond our photonic platform. 展开更多
关键词 NONLINEARITY TOPOLOGICAL COUPLING
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Disorder-protected quantum state transmission through helical coupled-resonator waveguides 被引量:1
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作者 JUNG YUN HAN ANDREY ASUKHORUKOV DANIEL LEYKAM 《Photonics Research》 SCIE EI CSCD 2020年第10期I0019-I0028,共10页
We predict the preservation of temporal indistinguishability of photons propagating through helical coupled-resonator optical waveguides(H-CROWs).H-CROWs exhibit a pseudospin-momentum locked dispersion,which we show s... We predict the preservation of temporal indistinguishability of photons propagating through helical coupled-resonator optical waveguides(H-CROWs).H-CROWs exhibit a pseudospin-momentum locked dispersion,which we show suppresscs on-site disorder-induced backscattering and group velocity fluctuations.We simulate numerically the propagation of two-photon wave packets,demonstrating that they exhibit almost perfect Hong-Ou-Mandel dip visibility and then can preserve their quantum coherence even in the presence of moderate disorder,in contrast with regular CROws,which are highly sensitive to disorder.As indistinguishability is the most fundamental resource of quantum information processing,H-CROWs may find applications for the implementation of robust optical links and delay lines in the emerging quantum photonic communication and computational platforms. 展开更多
关键词 RESONATOR WAVEGUIDES QUANTUM
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Simultaneous creation of multiple vortex-antivortex pairs in momentum space in photonic lattices 被引量:1
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作者 Feng Li Sergei V.Koniakhin +6 位作者 Anton V.Nalitov Evgeniia Cherotchenko Dmitry D.Solnyshkov Guillaume Malpuech Min Xiao Yanpeng Zhang Zhaoyang Zhang 《Advanced Photonics》 SCIE EI CAS CSCD 2023年第6期92-100,共9页
Engineering of the orbital angular momentum(OAM)of light due to interaction with photonic lattices reveals rich physics and motivates potential applications.We report the experimental creation of regularly distributed... Engineering of the orbital angular momentum(OAM)of light due to interaction with photonic lattices reveals rich physics and motivates potential applications.We report the experimental creation of regularly distributed quantized vortex arrays in momentum space by probing the honeycomb and hexagonal photonic lattices with a single focused Gaussian beam.For the honeycomb lattice,the vortices are associated with Dirac points.However,we show that the resulting spatial patterns of vortices are strongly defined by the symmetry of the wave packet evolving in the photonic lattices and not by their topological properties.Our findings reveal the underlying physics by connecting the symmetry and OAM conversion and provide a simple and efficient method to create regularly distributed multiple vortices from unstructured light. 展开更多
关键词 VORTEX photonic lattice orbital angular momentum TOPOLOGY SYMMETRY
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