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Lv H, Wang JC, Wu KL, Gao X, Wang LC, You L, Chen ZJ. Numb regulates meiotic spindle organisation in mouse oocytes. Reprod Fertil Dev 2010; 22:664-72. [PMID: 20353726 DOI: 10.1071/rd09236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 10/12/2009] [Indexed: 11/23/2022] Open
Abstract
Numb is an adaptor protein that controls the fate of cells in different species through asymmetrical inheritance by sibling cells during division. It has been investigated extensively in mitosis, mostly in neural progenitor cells, but its function in meiosis remains unknown. The present study was designed to investigate the expression, subcellular localisation and functional roles of Numb during mouse oocyte meiotic maturation. Using real-time polymerase chain reaction and western blotting, we found that the expression of Numb increased from the germinal vesicle (GV) to MII stages. Immunofluorescent staining revealed that Numb was mainly concentrated in the GV before meiosis resumption, aggregated in the vicinity of the chromosomes after GV breakdown and then localised to the spindle poles from prometaphase I to MII. Nocodazole treatment resulted in spindle destruction and Numb diffusion into the cytoplasm. However, Numb appeared at the spindle poles again once the spindles had formed when nocodazole-treated oocytes were washed and cultured for spindle recovery. Depletion of Numb by RNA interference resulted in chromosome misalignment, spindle deformation and even doubled spindle formation. Our results suggest that Numb is critical for spindle organisation during mouse oocytes meiosis. The present study provides evidence of a new function for Numb in addition to its action as a cell fate-determining factor.
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52
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Shi Y, Chen Z, Yan J, You L, Zhao Y. AC-018 Analysis of clinical characteristics in a large-scale study of Chinese women with polycystic ovary syndrome. Reprod Biomed Online 2008. [DOI: 10.1016/s1472-6483(10)61522-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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53
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Sun B, You L. Observing the Einstein-de Haas effect with atoms in an optical lattice. PHYSICAL REVIEW LETTERS 2007; 99:150402. [PMID: 17995144 DOI: 10.1103/physrevlett.99.150402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Indexed: 05/25/2023]
Abstract
The conservation of magnetization, or atomic spin angular momentum, is broken for anisotropic dipolar interactions. As a result, the Einstein-de Haas effect, or the transfer of spin to spatial angular momentum, arises because the total angular momentum is conserved. We identify the regime for observing this with two 87Rb atoms in a single well, stimulated by the recent result for a condensate. The two-atom system is found to be more easily observed and confirmed with the addition of a periodically modulated magnetic field. Our result of utilizing a feeble dipolar interaction may find potential applications in precision measurements.
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54
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Shi YH, Chen ZJ, You L, Zhao YR. Analysis of clinical data in a large-scale chinese women with polycystic ovary syndrome (PCOS). Fertil Steril 2007. [DOI: 10.1016/j.fertnstert.2007.07.626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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55
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Chang L, Zhai Q, Lu R, You L. Number fluctuation dynamics of atomic spin mixing inside a condensate. PHYSICAL REVIEW LETTERS 2007; 99:080402. [PMID: 17930933 DOI: 10.1103/physrevlett.99.080402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Indexed: 05/25/2023]
Abstract
We investigate the quantum dynamics of number fluctuations inside an atomic condensate during coherent spin mixing among internal states of the ground state hyperfine manifold, by quantizing the semiclassical nonrigid pendulum model in terms of the conjugate variable pair: the relative phase and the atom number. Our result provides a theoretical basis that resolves the resolution limit, or the effective "shot-noise" level, for counting atoms that is needed to clearly detect quantum correlation effects in spin mixing.
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56
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Reza F, Josephs E, Yuan F, Van Dyke B, Lin S, Feltz M, Chung H, Tian J, Heinz A, Tang N, O'Brien P, You L, Indurkhya S, Chandran K, Lakhani N, Lee J, LaBean T. Engineering novel synthetic biological systems. ACTA ACUST UNITED AC 2007. [DOI: 10.1049/iet-stb:20060004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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57
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Zhang P, Jen HH, Sun CP, You L. Angular momentum of a magnetically trapped atomic condensate. PHYSICAL REVIEW LETTERS 2007; 98:030403. [PMID: 17358664 DOI: 10.1103/physrevlett.98.030403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Revised: 09/12/2006] [Indexed: 05/14/2023]
Abstract
For an atomic condensate in an axially symmetric magnetic trap, the sum of the axial components of the orbital angular momentum and the hyperfine spin is conserved. Inside an Ioffe-Pritchard trap (IPT) whose magnetic field (B field) is not axially symmetric, the difference of the two becomes surprisingly conserved. In this Letter we investigate the relationship between the values of the sum or difference angular momentums for an atomic condensate inside a magnetic trap and the associated gauge potential induced by the adiabatic approximation. Our result provides significant new insight into the vorticity of magnetically trapped atomic quantum gases.
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58
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You L, Yin J. Evolutionary design on a budget: robustness and optimality of bacteriophage T7. ACTA ACUST UNITED AC 2006; 153:46-52. [PMID: 16986252 DOI: 10.1049/ip-syb:20050026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exploring how biological systems have been 'designed' by evolution to achieve robust behaviours is now a subject of increasing research effort. Yet, it still remains unclear how environmental factors may contribute to this process. This issue is addressed by employing a detailed computer model for the intracellular growth of phage T7. More than 150 000 in silico T7 mutants were generated and the rates and efficiencies of their growth in two host environments, namely, a realistic environment that offered finite host resources for the synthesis of phage functions and a hypothetical environment where the phage was supplied infinite host resources, were evaluated. Results revealed two key properties of phage T7. First, T7 growth was overall robust with respect to perturbations in its parameters, but fragile with respect to changes in the ordering of its genetic elements. Secondly, the wild-type T7 had close to optimal fitness in the finite environment. Furthermore, a strong correlation was found between fitness and growth efficiency in the finite environment. The results underscore the potential importance of the environment in shaping robust design of a biological system. In particular, the strong correlation between fitness and growth efficiency suggests that T7 may have evolved to maximise its growth rate by minimising waste of finite resources.
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59
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Sun B, Zhang WX, Yi S, Chapman MS, You L. Dipolar effect in coherent spin mixing of two atoms in a single optical lattice site. PHYSICAL REVIEW LETTERS 2006; 97:123201. [PMID: 17025962 DOI: 10.1103/physrevlett.97.123201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Indexed: 05/12/2023]
Abstract
We show that atomic dipolar effects are detectable in the system that recently demonstrated two-atom coherent spin dynamics within individual lattice sites of a Mott state. Based on a two-state approximation for the two-atom internal states and relying on a variational approach, we have estimated the spin dipolar effect. Despite the absolute weakness of the dipole-dipole interaction, it is shown that it leads to experimentally observable effects in the spin mixing dynamics.
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60
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Zhang M, Zhang P, Chapman MS, You L. Controlled splitting of an atomic wave packet. PHYSICAL REVIEW LETTERS 2006; 97:070403. [PMID: 17026215 DOI: 10.1103/physrevlett.97.070403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Indexed: 05/12/2023]
Abstract
We propose a simple scheme capable of adiabatically splitting an atomic wave packet using two independent translating traps. Implemented with optical dipole traps, our scheme allows a high degree of flexibility for atom interferometry arrangements and highlights its potential as an efficient and high fidelity atom optical beam splitter.
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61
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Thung E, Chou J, You L, Xu Z, Jablons D. Hypermethylation Silences Wnt Inhibitory Factor 1 in Nasopharyngeal Carcinoma. J Investig Med 2006. [DOI: 10.1177/108155890605401s28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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62
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You L, Temiyasathit S, Jacobs C. Osteocytes as mechanosensors in the inhibition of bone resorption due to mechanical loading. J Biomech 2006. [DOI: 10.1016/s0021-9290(06)82914-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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63
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You L, Kim J, He B, Xu Z, McCormick F, Jablons D. Wnt-1 signal as a potential cancer therapeutic target. ACTA ACUST UNITED AC 2006. [DOI: 10.1358/dnp.2006.19.1.965871] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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64
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Thung EG, Chou J, You L, Xu Z, Jablons DM. 144 HYPERMETHYLATION SILENCES WNT INHIBITORY FACTOR 1 IN NASOPHARYNGEAL CARCINOMA. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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65
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Mazieres J, You L, He B, Xu Z, Didier A, Jablons D. 061 Wnt2 as a new therapeutic target in malignant pleural mesothelioma. Rev Mal Respir 2005. [DOI: 10.1016/s0761-8425(05)92473-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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66
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Zhang W, Zhou DL, Chang MS, Chapman MS, You L. Dynamical instability and domain formation in a spin-1 Bose-Einstein condensate. PHYSICAL REVIEW LETTERS 2005; 95:180403. [PMID: 16383879 DOI: 10.1103/physrevlett.95.180403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Indexed: 05/05/2023]
Abstract
We interpret the recently observed spatial domain formation in spin-1 atomic condensates as a result of dynamical instability. Within the mean field theory, a homogeneous condensate is dynamically unstable (stable) for ferromagnetic (antiferromagnetic) atomic interactions. We find that this dynamical instability naturally leads to spontaneous domain formation as observed in several recent experiments for condensates with rather small numbers of atoms. For trapped condensates, our numerical simulations compare quantitatively to the experimental results, thus largely confirming the physical insight from our analysis of the homogeneous case.
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67
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Zeng B, Zhou DL, You L. Measuring the parity of an N-qubit state. PHYSICAL REVIEW LETTERS 2005; 95:110502. [PMID: 16196991 DOI: 10.1103/physrevlett.95.110502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Indexed: 05/04/2023]
Abstract
We present a scheme for a projective measurement of the parity operator Pz = Product(N)i=1 sigma(i)z of N qubits. Our protocol uses a single ancillary qubit, or a probe qubit, and involves manipulations of the total spin of the N qubits without requiring individual addressing. We illustrate our protocol in terms of an experimental implementation with atomic ions in a two-zone linear Paul trap, and further discuss its extensions to several more general cases.
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68
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He B, You L, Xu Z, Lee A, Reguart N, Rosell R, Jablons D. O-003 Writ inhibitory factor-1 (WIF-1) is silenced by promoter hypermethylation in human non-small cell lung cancer. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80135-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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69
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He B, Reguart N, Xu Z, You L, Jablons D. PD-013 SFRP4 is silenced by hypermethylation and induces apoptosis in beta-catenin-deficient human mesothelioma cells. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80345-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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70
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Sun Y, Wang J, Liu Y, Song X, Zhang Y, Li K, Zhu Y, Zhou Q, You L, Yao C. Results of phase III trial of rh-endostatin (YH-16) in advanced non-small cell lung cancer (NSCLC) patients. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.7138] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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71
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Yi S, You L, Pu H. Quantum phases of dipolar spinor condensates. PHYSICAL REVIEW LETTERS 2004; 93:040403. [PMID: 15323738 DOI: 10.1103/physrevlett.93.040403] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Indexed: 05/24/2023]
Abstract
We study the zero-temperature ground state structure of a spin-1 condensate with magnetic dipole-dipole interactions. We show that the dipolar interactions break the rotational symmetry of the Hamiltonian and induce new quantum phases. Different phases can be reached by tuning the effective strength of the dipolar interactions via modifying the trapping geometry. The experimental feasibility of detecting these phases is investigated. The spin-mixing dynamics is also studied.
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72
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Yi S, You L. Calibrating dipolar interaction in an atomic condensate. PHYSICAL REVIEW LETTERS 2004; 92:193201. [PMID: 15169400 DOI: 10.1103/physrevlett.92.193201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Indexed: 05/24/2023]
Abstract
We reexamine the topic of a dipolar condensate with the recently derived more rigorous pseudopotential for dipole-dipole interaction [Phys. Rev. A 67, 033607 (2003)]]. Based on the highly successful variational technique, we find that all dipolar effects estimated before (using the bare dipole-dipole interaction) become significantly larger, i.e., are amplified by the new velocity-dependent pseudopotential, especially in the limit of large or small trap aspect ratios. This result points to a promising prospect for detecting dipolar effects inside an atomic condensate.
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73
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Chang MS, Hamley CD, Barrett MD, Sauer JA, Fortier KM, Zhang W, You L, Chapman MS. Observation of spinor dynamics in optically trapped 87Rb Bose-Einstein condensates. PHYSICAL REVIEW LETTERS 2004; 92:140403. [PMID: 15089521 DOI: 10.1103/physrevlett.92.140403] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2003] [Indexed: 05/24/2023]
Abstract
We measure spin mixing of F=1 and F=2 spinor condensates of 87Rb atoms confined in an optical trap. We determine the spin mixing time to be typically less than 600 ms and observe spin population oscillations. The equilibrium spin configuration in the F=1 manifold is measured for different magnetic fields and found to show ferromagnetic behavior for low field gradients. An F=2 condensate is created by microwave excitation from the F=1 manifold, and this spin-2 condensate is observed to decay exponentially with time constant 250 ms. Despite the short lifetime in the F=2 manifold, spin mixing of the condensate is observed within 50 ms.
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74
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Zhang M, You L. Quantum Zeno subspace and entangled Bose-Einstein condensates. PHYSICAL REVIEW LETTERS 2003; 91:230404. [PMID: 14683166 DOI: 10.1103/physrevlett.91.230404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2003] [Indexed: 05/24/2023]
Abstract
We discuss a proposal for the efficient generation of the maximally entangled atomic N-GHZ state in a spinor-1 condensate by driving internal state atomic Raman transitions using (classical) laser fields. We illustrate the dynamics in terms of a quantum Zeno subspace and identify the resultant atomic elastic collision in facilitating the deterministic entanglement creation. Our proposal can be readily implemented in several laboratories where ferromagnetic spinor condensates (of 87Rb atoms) are investigated.
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75
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Yi S, Müstecaplioğlu OE, You L. Quantum phase diffusions of a spinor condensate. PHYSICAL REVIEW LETTERS 2003; 90:140404. [PMID: 12731901 DOI: 10.1103/physrevlett.90.140404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2002] [Indexed: 05/24/2023]
Abstract
We discuss the quantum phases and their diffusion in a spinor-1 atomic Bose-Einstein condensate. For ferromagnetic interactions, we obtain the exact ground state distribution of the phase fluctuations corresponding to the total atom number (N), the magnetization (M), and the alignment (or hypercharge) (Y) of the system. The mean-field ground state is shown to be stable against these fluctuations, which dynamically recover the two continuous symmetries associated with the conservation of N and M as in current experiments.
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