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PURPOSE: Renal artery stenosis leads to ischemic renal insufficiency, but methods for assessing renal perfusion are limited. This study aimed to evaluate the association between renal slow perfusion and impaired renal function in atherosclerotic renal artery stenosis (ARAS). PATIENTS AND METHODS: A total of 79 consecutive patients with uncontrolled hypertension who underwent renal angiography and renal dynamic scintigraphy for suspected ARAS were enrolled in the retrospective descriptive study. Based on the status of renal artery stenosis and renal perfusion, participants were divided into three groups: the control group (n=26), the unilateral ARAS with renal normal perfusion group (RNP, n=30), and the unilateral ARAS with renal slow perfusion group (RSP, n=23). RSP was defined as renal blush grade (RBG) ≤1, while RBG>1 belonged to RNP. Split renal function (SRF) was achieved from 99mTc-DTPA renal scintigraphy. The value of the difference in split renal function (DSRF) is contralateral SRF minus impaired SRF of paired kidneys in ARAS. We compared the SRF and DSRF between different groups to identify the association between renal slow perfusion and renal impairment in ARAS. RESULTS: We analyzed SRF for paired kidneys and found the following: (1) The SRF of the paired kidney was similar in the RNP group (24.3 ± 10.2 mL/min vs 27.5 ± 8.4 mL/min; P = 0.19); however, the impaired SRF was obviously decreased compared with the contralateral SRF in the RSP group (13.5 ± 8.6 mL/min vs 36.7 ± 16.9 mL/min; P < 0.001); and (2) The difference in SRF in the RSP group was significantly higher than that in the control and RNP groups (19.8 ± 11.9 mL/min vs 4.8 ± 8.1 mL/min; 19.8 ± 11.9 mL/min vs 4.6±3.7 mL/min; P < 0.05). CONCLUSION: As an angiographic phenomenon, renal slow perfusion might be an indicator of severely impaired renal function.
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Adiabatic quantum control is a very important approach for quantum physics and quantum information processing (QIP). It holds the advantage with robustness to experimental imperfections but accumulates more decoherence due to the long evolution time. Here, we propose a universal protocol for fast and robust quantum control in multimode interactions of a quantum system by using shortcuts to adiabaticity. The results show this protocol can speed up the evolution of a multimode quantum system effectively, and it can also keep the robustness very good while adiabatic quantum control processes cannot. We apply this protocol for the quantum state transfer in QIP in the photon-phonon interactions in an optomechanical system, showing a perfect result. These good features make this protocol have the capability of improving effectively the feasibility of the practical applications of multimode interactions in QIP in experiment.
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Quantum repeater is the key element in quantum communication and quantum information processing. Here, we investigate the possibility of achieving a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We design the compact quantum circuits for nonlocal entanglement generation, entanglement swapping, and entanglement purification, and discuss the feasibility of our protocols with current experimental technology. In our scheme, we use a parametric down-conversion source instead of ideal single-photon sources to realize the heralded quantum repeater. Moreover, our protocols can turn faulty events into the detection of photon polarization, and the fidelity can reach 100% in principle. Our scheme is attractive and scalable, since it can be realized with artificial solid-state quantum systems. With developed experimental technique on controlling emitter-waveguide systems, the repeater may be very useful in long-distance quantum communication.
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We investigate the formation of discrete breathers (DBs) and the dynamics of the mixture of two-species Bose-Einstein condensates (BECs) in open boundary optical lattices using the discrete nonlinear Schrödinger equations. The results show that the coupling of intra- and interspecies interaction can lead to the existence of pure single-species DBs and symbiotic DBs (i.e., two-species DBs). Furthermore, we find that there is a selective distillation phenomenon in the dynamics of the mixture of two-species BECs. One can selectively distil one species from the mixture of two-species BECs and can even control dominant species fraction by adjusting the intra- and interspecies interaction in optical lattices. Our selective distillation mechanism may find potential application in quantum information storage and quantum information processing based on multi-species atoms.
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Atomic ensembles are effective memory nodes for quantum communication network due to the long coherence time and the collective enhancement effect for the nonlinear interaction between an ensemble and a photon. Here we investigate the possibility of achieving the entanglement distillation for nonlocal atomic ensembles by the input-output process of a single photon as a result of cavity quantum electrodynamics. We give an optimal entanglement concentration protocol (ECP) for two-atomic-ensemble systems in a partially entangled pure state with known parameters and an efficient ECP for the systems in an unknown partially entangled pure state with a nondestructive parity-check detector (PCD). For the systems in a mixed entangled state, we introduce an entanglement purification protocol with PCDs. These entanglement distillation protocols have high fidelity and efficiency with current experimental techniques, and they are useful for quantum communication network with atomic-ensemble memories.
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In the present paper, the absorption spectra of Ho3+ (0.5 mol%)-doped oxyfluoride glass (FOG) sample and Ho3+ (0.5 mol%)-doped oxyfluoride vitroceramics (FOV) sample were measured through experiment. The authors calculated the intensity parameters omega 2, 4, 6 of the two materials according to J-O theory, and analyzed the possible reason for the difference between the two materials on the intensity parameters. After that the authors calculated oscillator strength, spontaneous radiative transition rate, branching ratio and integrated emission cross section and some other spectroscopic parameters of several excited states and then made a comparative analysis of the two materials based on these spectroscopic parameters. The authors found that the oscillator strength of trivalent holmium iron in FOV is about the same with the oscillator strength in YAlO3 and is similar to oscillator strength in FOG, while slightly larger than in that LBTAF and much larger than that in LaF3 and ZBLAN. By analyzing the calculated spectroscopic parameters, it can be found that some transitions, especially 5I7 --> 5I8, 5F5 --> 5I8 etc., have a relatively large oscillator strengths(larger than 10(-6)) and large integrated emission cross sections(larger than 10(-18) cm). These transitions have the conditions to form laser passages, so they are worth a lot of attention. At last, application prospects of several strong luminescence transitions were concluded.
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Infrared quantum cutting of rare earth ion is an international hot research field. It is significant for the enhancement of solar cell efficiency and for the reduction of solar cell price. The present paper summarizes the research significance of infrared quantum cutting of rare earth ion. Based on the summarization of general principle and loss mechanism of solar cell, the possible method to enhance the solar cell efficiency by infrared quantum cutting is analyzed. Meanwhile, the present paper summarizes the infrared quantum cutting phenomena of Er3+ ion single-doped material. There is intense 4I13/2 --> 4I15/2 infrared quantum cutting luminescence of Er3+ ion when the 2H11/2 energy level is excited. The intense {2H11/2 --> 4I9/2, 4I15/2 --> 4I13/2} cross energy transfer is the main reason for the result in the high quantum cutting efficiency when the 2H11/2 energy level is excited.
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The present article reports the infrared quantum cutting study of the nanophase oxyfluoride vitroceramics Tb(0.7)Yb (5.0) : FOV. The visible to infrared fluorescence emission spectra, excitation spectra and fluorescence lifetime were measured carefully. The infrared quantum cutting phenomenon {1([5 D4 --> 7 F6](Tb3+), 2([2 F7/2 --> 2 F5/2](Yb3+)} was analyzed based on the above experiments. It was found that the theoretical quantum cutting efficiency is about 121.35% when 5D4 level is excited by 487.0nm light, and about 136.27% when (5D3, 5G6) levels are excited by 378.0 nm light respectively. Meanwhile, it is first time for the present paper to find a cooperative downconversion phenomenon {2([(5D3, 5G6) --> 5D4] (Tb3+), 1([2 F7/2 --> 2 F5/2] (Yb3+)}. That is, the authors found for the first time that the donor Tb3+ ion releases two pieces of energy [(5D3, 5G6) --> 5D4] of small energy photon to produce a middle energy photon [2 F5/2 --> 2 F7/2] of acceptor Yb3+ ion.
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The upconversion luminescence of nanophase oxyfluoride vitroceramics Tm(0.35)Yb(5) : FOV when excited by a 975 nm diode laser was studied in the present paper. Several ultraviolet upconversion luminescence lines positioned at 363.6 nm, (462.6 nm, 477.0 nm), 648.7 nm, (699.7 nm, 680.7 nm) and (777.6 nm, 800.7 nm) were found. They can be attributed to the fluorescence transitions of 1 D2-->3 H6, 1 G4-->3 H6, 1 G4-->3 F4, 3 F3-->3 H6 and 3 H4-->3 H6 of Tm3+ ion. The careful measurement and analysis of the variation of upconversion luminescence intensity F as a function of the 975 nm pumping laser power P has proven that the upconversion luminescence of 1 D2 state is partly a five-photon upconversion luminescence, while the upconversion luminescence of 1 G4 and 3 H4 state is the three-photon and two-photon upconversion luminescence respectively.