2,003 research outputs found

    Quantum tunneling time of a Bose-Einstein condensate traversing through a laser-induced potential barrier

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    We theoretically study the effect of atomic nonlinearity on the tunneling time in the case of an atomic Bose-Einstein condensate (BEC) traversing the laser-induced potential barrier. The atomic nonlinearity is controlled to appear only in the region of the barrier by employing the Feshbach resonance technique to tune interatomic interaction in the tunneling process. Numerical simulation shows that the atomic nonlinear effect dramatically changes the tunneling behavior of the BEC matter wave packet, and results in the violation of Hartman effect and the occurrence of negative tunneling time.Comment: 4 pages, 5 figure

    catena-Poly[[bis­[2-(2-pyrid­yl)-1-H-imidazole-Îș2 N 2,N 3]cadmium]-ÎŒ-benzene-1,3-dicarboxyl­ato-Îș2 O 1:O 3]

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    In the title coordinaltion polymer, [Cd(C8H4O4)(C8H7N3)2]n, the CdII atom, lying on a twofold rotation axis, is six-coordinated by two carboxyl­ate O atoms from two benzene-1,3-dicarboxyl­ate (m-BDC) ligands and four N atoms from two chelating 2-(2-pyrid­yl)imidazole mol­ecules, forming a slightly distorted octa­hedral geometry. The m-BDC ligand is located over a twofold rotation axis. The CdII atoms are bridged by the m-BDC ligands, leading to a wave-shaped chain structure along [010]. N—H⋯O hydrogen bonds connect the chains

    Long-term unmet needs after stroke:systematic review of evidence from survey studies

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    OBJECTIVES: To synthesise evidence on longer term unmet needs perceived by stroke survivors, and psychometric properties of the tools used to evaluate unmet care needs after stroke. DESIGN: Systematic review. SETTING: Community or patients' home. PARTICIPANTS: Stroke survivors. METHODS: We searched PubMed, PsycINFO, CINAHL, EMBASE from inception to 31 March 2018 to identify survey studies that evaluated unmet needs perceived by stroke survivors after hospital discharge. Reported unmet needs were categorised under three domains: body functioning, activity/participation and environmental factors. Ranges of prevalence rates of unmet needs reported in studies were presented. RESULTS: We included 19 eligible studies, with considerable heterogeneity in patients, survey methods and results. Psychometric properties of two stroke-specific tools were formally evaluated, indicating their moderate reliability and content/concurrent validity. The median number of reported unmet needs per stroke survivor was from two to five, and the proportion of stroke survivors with at least one unmet needs was on average 73.8% (range 19.8%- 91.7%). Unmet needs perceived by stroke survivors included 55 records of unmet body functioning needs, 47 records of unmet activities/participatory needs and 101 records of unmet environmental needs. Common unmet service needs were unmet information needs (3.1%- 65.0%), transport (5.4%-53.0%), home help/personal care (4.7%-39.3%) and therapy (2.0%-35.7%). CONCLUSIONS: The prevalence of unmet long-term needs is high among stroke survivors, and there is considerable heterogeneity in type and frequency of specific unmet needs. More research is required to link regular assessment of long-term unmet needs of stroke survivors with the provision of cost-effective patient-centred health and social care services

    A dinuclear copper complex: bis­(Ό-4-amino­benzoato)bis­[aqua(1,10-phenanthroline)copper(II)] dichloride bis(4-amino­benzoic acid) dihydrate

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    The title complex, [Cu2(C7H6NO2)2(C12H8N2)2(H2O)2]·2C7H7NO2·2H2O, consists of a dinuclear [Cu2(C7H6NO2)2(C12H8N2)2(H2O)2]2+ cation, two Cl− anions, two 4-amino­benzoic acid mol­ecules and two disordered water mol­ecules (site occupancy factors 0.5). The Cu(II) ion adopts a distorted square-pyramidal geometry formed by two N atoms from the 1,10-phenanthroline ligand and two O atoms of the two 4-amino­benzoic acid ligands and one water O atom. The Cu⋯Cu separation is 3.109 (2) Å. A twofold axis passes through the mid-point of the Cu⋯Cu vector

    Quantum theory of electronic double-slit diffraction

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    The phenomena of electron, neutron, atomic and molecular diffraction have been studied by many experiments, and these experiments are explained by some theoretical works. In this paper, we study electronic double-slit diffraction with quantum mechanical approach. We can obtain the results: (1) When the slit width aa is in the range of 3λ∌50λ3\lambda\sim 50\lambda we can obtain the obvious diffraction patterns. (2) when the ratio of d+aa=n(n=1,2,3,⋅⋅⋅)\frac{d+a}{a}=n (n=1, 2, 3,\cdot\cdot\cdot), order 2n,3n,4n,⋅⋅⋅2n, 3n, 4n,\cdot\cdot\cdot are missing in diffraction pattern. (3)When the ratio of d+aa≠n(n=1,2,3,⋅⋅⋅)\frac{d+a}{a}\neq n (n=1, 2, 3,\cdot\cdot\cdot), there isn't missing order in diffraction pattern. (4) We also find a new quantum mechanics effect that the slit thickness cc has a large affect to the electronic diffraction patterns. We think all the predictions in our work can be tested by the electronic double-slit diffraction experiment.Comment: 9pages, 14figure

    Corneal stromal acupuncture combined with amniotic membrane transplantation for treating bullous keratopathy

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    AIM: To investigate the clinical effect for treating bullous keratopathy(BK)by anterior corneal stromal acupuncture combined with amniotic membrane transplantation.<p>METHODS: Totally 35 patients(35 eyes)with bullous keratopathy were treated by corneal stromal acupuncture combined with amniotic membrane transplantation. All patients preoperative and postoperative underwent anterior segment OCT, corneal topography, corneal sensitivity and confocal microscopy. To observe postoperative ocular symptoms in patients with BK, recurrence of bulla, changes in corneal thickness, corneal sensitivity and changes in the organizational structure of the layers of the cornea.<p>RESULTS: Thirty-five were followed up for 6-18mo. The symptom of pain disappeared in 32 cases(91%)in the first day after operation and did not recur during follow-up. The symptom of pain relieved in 3 cases(9%)in the first day after operation and disappeared in 3 days. Corneal epithelium of 9 cases(26%)were all healed within 1wk, 21 cases(60%)were all healed within 2wk, and 5 cases(14%)were all healed within 3wk. Following up for 6-18mo, there was no recurrence of symptoms or bulla. A small amount of tiny bubbles in the surrounding area appeared in 2 cases after 3 and 4wk. All patients had no neovascularization, and had smooth corneal surface. The amnions of 30 cases(86%)were thinning after 2mo, partially dissolved and absorped, not seen with the naked eye after 3mo. Thirty-four cases(97%)had no changes in vision, one case(3%)was from the light to front of the manual. After 2mo, corneal sensation decreased in 30 cases(86%), corneal thickness increased from preoperative 788±35Όm to 940±43Όm. After 12mo, corneal thickness increased to 1060±27Όm. Results of confocal microscopy: after 3mo, the number density of the trigeminal nerve fibers under corneal basement membrane reduced, shallow stromal cells became into fibrotic stroma, deep stroma was more loose, and cells swelled significantly. The number of endothelial cells reduced and form swelled more obviously compared with preoperatively.<p>CONCLUSION: Corneal acupuncture combined with amniotic membrane transplantation can effectively control the symptoms of BK, prevent the recurrence of BK, and especially it is a simple, safe and practical way for patients with poor visual function

    Seed Oil of Brucea javanica Induces Apoptotic Death of Acute Myeloid Leukemia Cells via Both the Death Receptors and the Mitochondrial-Related Pathways

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    Seed oil of Brucea javanica (BJO) is extracted from the seeds of herb medicine Brucea javanica (L.), and its emulsion formulation (BJOE) has been used clinically to treat carcinomas for many years in China. The antileukemia potential of BJO was investigated in human acute myeloid leukemia cell lines (AML) U937 and HL-60 in vitro and in a mouse U937 xenograft tumor model. BJO induced AML cell apoptosis through activation of caspase-8 and modulation of apoptosis-related proteins. Meanwhile, the inhibition of survivin and XIAP increased the cytotoxicity of BJO. Consistent with these findings, BJO also increased subG1 phase cells and cause PARP cleavage in AML patients' leukemia cells. In contrast, only weak cytotoxicity of BJO was found in peripheral blood lymphocytes (PBLs) of healthy volunteers. Moreover, oleic acid and linoleic acid were found to be the active components of BJO. Our study provided strong evidence for the first time that BJO induced apoptosis of both cultured and primary AML cells. Furthermore, intravenous injection of BJO significantly inhibited U937 tumor growth in the xenograft mouse model. These results suggest that BJO may have a therapeutic role in the treatment of human leukemia
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