Single-Photon Interference over 8.4 km Urban Atmosphere: Toward Testing Quantum Effects in Curved Spacetime with Photons.

The emergence of quantum mechanics and general relativity has transformed our understanding of the natural world significantly. However, integrating these two theories presents immense challenges, and their interplay remains untested. Recent theoretical studies suggest that the single-photon interference covering huge space can effectively probe the interface between quantum mechanics and general relativity. We developed an alternative design using unbalanced Michelson interferometers to address this and validated its feasibility over an 8.4 km free-space channel. Using a high-brightness single-photon source based on quantum dots, we demonstrated single-photon interference along this long-distance baseline. We achieved a phase measurement precision of 16.2 mrad, which satisfied the measurement requirements for a gravitational redshift at the geosynchronous orbit by 5 times the standard deviation. Our results confirm the feasibility of the single-photon version of the Colella-Overhauser-Werner experiment for testing the quantum effects in curved spacetime.

Quantum State Transfer over 1200 km Assisted by Prior Distributed Entanglement.

Long-distance quantum state transfer (QST), which can be achieved with the help of quantum teleportation, is a core element of important quantum protocols. A typical situation for QST based on teleportation is one in which two remote communication partners (Alice and Bob) are far from the entanglement source (Charlie). Because of the atmospheric turbulence, it is challenging to implement the Bell-state measurement after photons propagate in atmospheric channels. In previous long-distance free-space experiments, Alice and Charlie always perform local Bell-state measurement before the entanglement distribution process is completed. Here, by developing a highly stable interferometer to project the photon into a hybrid path-polarization dimension and utilizing the satellite-borne entangled photon source, we demonstrate proof-of-principle QST at the distance of over 1200 km assisted by prior quantum entanglement shared between two distant ground stations with the satellite Micius. The average fidelity of transferred six distinct quantum states is 0.82±0.01, exceeding the classical limit of 2/3 on a single copy of a qubit.

[Identification of origins of marker chromosomes using fluorescence in situ hybridization].

OBJECTIVE: To assess the value of fluorescence in situ hybridization (FISH) and bacterial artificial chromosome FISH (BAC-FISH) for the diagnosis for patients with marker chromosomes. METHODS: Sixteen patients with marker chromosomes were analyzed with technologies including GTG-banding, Q-banding, multiplex FISH and BAC-FISH. RESULTS: The marker chromosomes in the 16 patients were verified as der(Y) (2 cases), psu dic(Y) (1 case), psu dic(15) (1 case), dic(15) (1 case), del(Y) (1 case), r(X) (5 cases), i(14 or 22) (2 cases), i(18) (1 case). CONCLUSION: FISH and BAC-FISH can both verify the origin of marker chromosomes and provide accurate information for the diagnosis and treatment of patients.

[Application of fluorescence in situ hybridization in prenatal diagnosis of complex chromosomal abnormalities].

OBJECTIVE: To investigate the application of fluorescence in situ hybridization (FISH) technique in prenatal diagnosis of complex chromosomal abnormalities. METHODS: Eleven prenatal diagnosis cases (8 from amniocentesis and 3 from cord blood) with complex chromosomal abnormalities detected by routine G-banding, were further analyzed by FISH. RESULTS: The FISH technique confirmed the results of balanced chromosome rearrangements detected by G-banding, and clarified the structure of the derivative chromosomes in the 3 amniocentesis samples and the origin of the mark chromosomes in the 2 cord blood samples. CONCLUSION: FISH can be used to diagnose the complex chromosomal abnormalities accurately in prenatal diagnosis, and can provide very useful genetic information for clinical diagnosis and treatment.

Satellite testing of a gravitationally induced quantum decoherence model.

Quantum mechanics and the general theory of relativity are two pillars of modern physics. However, a coherent unified framework of the two theories remains an open problem. Attempts to quantize general relativity have led to many rival models of quantum gravity, which, however, generally lack experimental foundations. We report a quantum optical experimental test of event formalism of quantum fields, a theory that attempts to present a coherent description of quantum fields in exotic spacetimes containing closed timelike curves and ordinary spacetime. We experimentally test a prediction of the theory with the quantum satellite Micius that a pair of time-energy-entangled particles probabilistically decorrelate passing through different regions of the gravitational potential of Earth. Our measurement results are consistent with the standard quantum theory and hence do not support the prediction of event formalism.

[Molecular cytogenetic studies of 25 males with azoospermia].

OBJECTIVE: To investigate the clinical correlation of chromosome abnormalities and microdeletion in azoospermic factor (AZF) region on Y chromosome in 25 patients with azoospermia. METHODS: Chromosome analyses were performed by using chromosome GTG-banding, Q-banding, fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) for AZF region on chromosome Yq. RESULTS: Seven cases showed abnormal chromosome karyotype (28%). In 8 azoospermic patients tested, 2 showed microdeletions of AZFb (SY127, SY134)+ AZFc (SY254, SY255) and AZFc(SY243, SY158) on chromosome Yq, respectively. CONCLUSION: Chromosome abnormalities and AZF microdeletion are major cause of azoospermia leading to male infertility; male with azoospermia and infertility should be referred to cytogenetic diagnosis by using chromosome GTG-banding, Q-banding after ruling out clinical factors including testopathy, obstructive azoospermia, and abnormalities in incretion and immune system. FISH or PCR analysis for AZF region on chromosome Yq should be done for the patient with azoospermia if Q-banding indicates the deletion above Yq12 region. It is of essential importance to provide precise diagnosis in genetic counseling for further clinical treatment.

[Molecular and cytogenetic study on 18 cases of amenorrhea: the use of fluorescence in situ hybridization and high resolution-comparative genomic hybridization].

OBJECTIVE: To explore the use of fluorescence in situ hybridization (FISH) and high resolution-comparative genomic hybridization (HR-CGH) techniques in amenorrhea study. METHODS: After routine gynecologic examination, ultrasonography and endocrine examination, 17 cases of primary amenorrhea and 1 case of secondary amenorrhea were analysed by using chromosomal diagnoses including multiplex FISH and HR-CGH analyses. RESULTS: Among 17 cases of primary amenorrhea, 7 revealed a 46,XX karyotype; 10 cases (58.8%) had abnormal karyotype, including 3 cases of 46,XY females, 2 cases of Turner's syndrome with 45,X and 45,X/46,XX, and other 5 cases with abnormal structure of X chromosome (including partial monosomy of X,X isochromosome and X/Y mosaic). The karyotype of the patient with secondary amenorrhea was translocation between X chromosome and euchromosome. CONCLUSION: The using of FISH and HR-CGH can correctly diagnose the patients' karyotypes, and provide absolutely necessarily medical genetic data for clinical diagnosis and therapy.