Quantum speed limit of a single atom in a squeezed optical cavity mode

We theoretically study the quantum speed limit of a single atom trapped in a Fabry-Perot microresonator.The cavity mode will be squeezed when a driving laser is applied to the second-order nonlinear medium,and the effective Hamiltonian can be obtained under the Bogoliubov squeezing transformation.The analytical expression of the evolved atom state can be obtained by using the non-Hermitian Schr¨odinger equation for the initial excited state,and the quantum speed limit time coincides very well for both the analytical expression and the master equation method.From the perspective of quantum speed limit,it is more conducive to accelerate the evolution of the quantum state for the large detuning,strong driving,and coupling strength.For the case of the initial superposition state,the form of the initial state has more influence on the evolution speed.The quantum speed limit time is not only dependent on the system parameters but also determined by the initial state.

The clinical characteristics and treatment outcomeof 57 children and adolescents with primary central nervoussystem germ cell tumors

Primary central nervous system germ cell tumors(CNS-GCTs) in children and adolescents have unique clinical features and methods of treatment compared with those in adults. There is little information about Chinese children and adolescents with CNS-GCTs. Therefore, in this study we retrospectively analyzed the clinical features and treatment outcome of Chinese children and adolescents with primary CNS-GCTs. Between January 2002 and December 2012, 57 untreated patients from a single institution were enrolled. They were diagnosed with CNS-GCTs after pathologic or clinical assessment. Of the 57 patients, 41 were males and 16 were females, with a median age of 12.8 years(range, 2.7 to 18.0 years) at diagnosis; 43(75.4%) had non-germinomatous germ cell tumors(NGGCTs) and 14(24.6%) had germinomas; 44(77.2%) had localized disease and 13(22.8%) had extensive lesions. Fifty-three patients completed the prescribed treatment, of which 18 underwent monotherapy of surgery, radiotherapy, or chemotherapy, and 35 underwent multimodality therapies that included radiotherapy combined with chemotherapy or surgery combined with chemotherapy and/or radiotherapy. PEB(cisplatin, etoposide, and bleomycin) protocol was the major chemotherapy regimen. The median follow-up time was 32.3 months(range, 1.2 to 139 months). Fourteen patients died of relapse or disease progression. The 3-year event-free survival(EFS) and overall survival rates for all patients were 72.2% and 73.8%, respectively. The 3-year EFS was 92.9% for germinomas and 64.8% for NGGCTs(P = 0.064). The 3-year EFS rates for patients with NGGCTs who underwent monotherapy and multimodality therapies were 50.6% and 73.5%, respectively(P = 0.042). Our results indicate that multimodality therapies including chemotherapy plus radiotherapy were better treatment option for children and adolescents with CNS-GCTs.

Quantum speed limit for the maximum coherent state under the squeezed environment

The quantum speed limit time for quantum system under squeezed environment is studied.We consider two typical models,the damped Jaynes-Cummings model and the dephasing model.For the damped Jaynes-Cummings model under squeezed environment,we find that the quantum speed limit time becomes larger with the squeezed parameter r increasing and indicates symmetry about the phase parameter valueθ=π.Meanwhile,the quantum speed limit time can also be influenced by the coupling strength between the system and environment.However,the quantum speed limit time for the dephasing model is determined by the dephasing rate and the boundary of acceleration region that interacting with vacuum reservoir can be broken when the squeezed environment parameters are appropriately chosen.

Margolus-Levitin speed limit across quantum to classical regimes based on trace distance

The classical version of Mandelstam-Tamm speed limit based on theWigner function in phase space was reported by Shanahan et al.[Phys.Rev.Lett.120070401(2018)].We present the Margolus-Levitin speed limit across the quantumto-classical transition in phase space based on the trace distance.The Margolus-Levitin speed limit is set by the Schatten L1 norm of the generator of time-dependent evolution for both the quantum and classical domains.As an example,the time-dependent harmonic oscillator is considered to illustrate the result.

云南省昆明市动物园和宠物市场中鸟类鹦鹉热衣原体的流行病学调查及其基因型分布研究（英文）

目的:调查云南省昆明市动物园和宠物市场的鹦形目鸟类中鹦鹉热衣原体的流行情况。创新点:首次在云南地区开展鹦形目鸟类中鹦鹉热衣原体的流行病学调查,发现该地区鹦形目鸟类中具有较高的鹦鹉热衣原体感染率。方法:本研究共采集8种鹦形目鸟类的新鲜粪便样本136份,其中动物园样本60份,宠物市场样本76份。首先,利用高灵敏和高特异性的TaqMan MGB探针荧光定量聚合酶链反应(qPCR)方法检测粪便样品中鹦鹉热衣原体的感染率,然后针对阳性样品,利用PCR技术进行鹦鹉热衣原体OmpA基因扩增、纯化、测序以及基因型分析。结论:本实验结果显示:鹦鹉热衣原体的感染率为19.9%(27/136),其中宠物市场鸟类中鹦鹉热衣原体的感染率(26.3%;20/76)明显高于动物园(11.7%;7/60)(P=0.034);金刚鹦鹉中感染率最高,达41.2%(7/17)。同缘关系进化树分析表明,这些鹦鹉热衣原体都属于易于由鸟向人跨物种传播的A型。综上所述,昆明地区鹦形目鸟类中具有较高的鹦鹉热衣原体流行,给饲养人员和观鸟者的健康带来了潜在的威胁。