446 research outputs found

    Correlated Quantum Memory: Manipulating Atomic Entanglement via Electromagnetically Induced Transparency

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    We propose a feasible scheme of quantum state storage and manipulation via electromagnetically induced transparency (EIT) in flexibly unitedunited multi-ensembles of three-level atoms. For different atomic array configurations, one can properly steer the signal and the control lights to generate different forms of atomic entanglement within the framework of linear optics. These results shed new light on designing the versatile quantum memory devices by using, e.g., an atomic grid.Comment: 5 pages, 1 figur

    ZnO homojunction photodiodes based on Sb-doped p-type nanowire array and n-type film for ultraviolet detection

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    ZnO p-n homojunctions based on Sb-doped p-type nanowire array and n-type film were grown by combining chemical vapor deposition (for nanowires) with molecular-beam epitaxy (for film). Indium tin oxide and Ti/Au were used as contacts to the ZnO nanowires and film, respectively. Characteristics of field-effect transistors using ZnO nanowires as channels indicate p-type conductivity of the nanowires. Electron beam induced current profiling confirmed the existence of ZnO p-n homojunction. Rectifying I-V characteristic showed a turn-on voltage of around 3 V. Very good response to ultraviolet light illumination was observed from photocurrent measurements

    Bioluminescence imaging of hepatitis B virus enhancer and promoter activities in mice

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    AbstractBy bioluminescence imaging and hydrodynamic gene transfer technology, the activities of hepatitis B virus (HBV) promoters and the effects of HBV enhancers on these promoters in mice under true physiological conditions have been assessed. Our studies reveal that either of the two HBV enhancers can stimulate HBV major promoter activity in hepa 1–6 cells (in vitro) and in mouse liver (in vivo), and the enhancer effects on the three promoters (S1, S2 and X promoter) are markedly greater in vivo than in vitro. The two HBV enhancers have no cooperative action on HBV promoters in vitro or in vivo

    Enhanced surface acceleration of fast electrons by using sub-wavelength grating targets

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    Surface acceleration of fast electrons in intense laser-plasma interaction is improved by using sub-wavelength grating targets. The fast electron beam emitted along the target surface was enhanced by more than three times relative to that by using planar target. The total number of the fast electrons ejected from the front side of target was also increased by about one time. The method to enhance the surface acceleration of fast electron is effective for various targets with sub-wavelength structured surface, and can be applied widely in the cone-guided fast ignition, energetic ion acceleration, plasma device, and other high energy density physics experiments.Comment: 14 pages, 4figure

    Iron and Alzheimer’s Disease: From Pathogenesis to Therapeutic Implications

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    As people age, iron deposits in different areas of the brain may impair normal cognitive function and behavior. Abnormal iron metabolism generates hydroxyl radicals through the Fenton reaction, triggers oxidative stress reactions, damages cell lipids, protein and DNA structure and function, and ultimately leads to cell death. There is an imbalance in iron homeostasis in Alzheimer’s disease (AD). Excessive iron contributes to the deposition of β-amyloid and the formation of neurofibrillary tangles, which in turn, promotes the development of AD. Therefore, iron-targeted therapeutic strategies have become a new direction. Iron chelators, such as desferoxamine, deferiprone, deferasirox, and clioquinol, have received a great deal of attention and have obtained good results in scientific experiments and some clinical trials. Given the limitations and side effects of the long-term application of traditional iron chelators, alpha-lipoic acid and lactoferrin, as self-synthesized naturally small molecules, have shown very intriguing biological activities in blocking Aβ-aggregation, tauopathy and neuronal damage. Despite a lack of evidence for any clinical benefits, the conjecture that therapeutic chelation, with a special focus on iron ions, is a valuable approach for treating AD remains widespread

    Diffusion basis spectrum imaging detects axonal loss after transient dexamethasone treatment in optic neuritis mice

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    Optic neuritis is a frequent first symptom of multiple sclerosis (MS) for which corticosteroids are a widely employed treatment option. The Optic Neuritis Treatment Trial (ONTT) reported that corticosteroid treatment does not improve long-term visual acuity, although the evolution of underlying pathologies is unclear. In this study, we employed non-invasive diffusion basis spectrum imaging (DBSI)-derived fiber volume to quantify 11% axonal loss 2 months after corticosteroid treatment (vs. baseline) in experimental autoimmune encephalomyelitis mouse optic nerves affected by optic neuritis. Longitudinal DBSI was performed at baseline (before immunization), after a 2-week corticosteroid treatment period, and 1 and 2 months after treatment, followed by histological validation of neuropathology. Pathological metrics employed to assess the optic nerve revealed axonal protection and anti-inflammatory effects of dexamethasone treatment that were transient. Two months after treatment, axonal injury and loss were indistinguishable between PBS- and dexamethasone-treated optic nerves, similar to results of the human ONTT. Our findings in mice further support that corticosteroid treatment alone is not sufficient to prevent eventual axonal loss in ON, and strongly support the potential of DBSI as a

    Measurement of the quadratic Zeeman shift of ^{85}Rb hyperfine sublevels using stimulated Raman transitions

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    We demonstrate a technique for directly measuring the quadratic Zeeman shift using stimulated Raman transitions.The quadratic Zeeman shift has been measured yielding [delta][nju] = 1296.8 +/-3.3 Hz/G^{2} for magnetically insensitive sublevels (5S1/2, F = 2,mF = 0 -> 5S1/2, F = 3,mF = 0) of ^{85}Rb by compensating the magnetic eld and cancelling the ac Stark shift. We also measured the cancellation ratio of the differential ac Stark shift due to the imbalanced Raman beams by using two pairs of Raman beams ([sigma]^{+}, [sigma]^{+}) and it is 1:3.67 when the one-photon detuning is 1.5 GHz in the experiment

    Analysis and realization of pathology diagnosis on intraoperative frozen sections of papillary thyroid carcinoma

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    目的  探讨术中冷冻切片在甲状腺肿瘤手术中的应用,提高甲状腺乳头状癌术中冷冻病理诊断的准确率。方法  回顾性观察我科43例甲状腺乳头状癌患者的术中冷冻切片。结果  术中冷冻切片诊断甲状腺乳头状癌43例,确诊率为100%。结论  为提高术中冷冻切片病理诊断的准确性,必须加强与临床医师沟通,详细了解患者的临床资料,正确全面的取材,掌握甲状腺乳头状癌的病理诊断及鉴别要点,提高冷冻切片质量。Objective:To explore the application of intraoperative frozen sections in thyroid tumor surgery and to improve its diagnostic accuracy in thyroid tumor surgery. Methods:To respectively analyze the intraoperative frozen sections of 43 cases of papillary thyroid carcinoma in our department. Results:By intraoperative frozen sections, 43 cases of papillary thyroid carcinoma were diagnosed, the diagnostic accuracy amounting to 100%.Conclusion:Increasing the diagnosis accuracy of intraoperative frozen sections counts in understanding clinical data in detail,drawing materials correctly and comprehensively,commanding common papillary thyroid carcinoma pathologic diagnosis and differentiated points,enhancing the communication with clinicians and improving the quality of frozen sections
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