Directly diode-pumped, Kerr-lens mode-locked, few-cycle Cr:ZnSe oscillator

Lasers based on Cr$^{2+}$-doped II-VI material, often known as the Ti:Sapphire of the mid-infrared, can directly provide few-cycle pulses with super-octave-spanning spectra, and serve as efficient drivers for generating broadband mid-infrared radiation. It is expected that the wider adoption of this technology benefits from more compact and cost-effective embodiments. Here, we report the first directly diode-pumped, Kerr-lens mode-locked Cr$^{2+}$-doped II-VI oscillator pumped by a single InP diode, providing average powers of over 500 mW and pulse durations of 45 fs - shorter than six optical cycles at 2.4 $\mu$m. These correspond to a sixty-fold increase in peak power compared to the previous diode-pumped record, and are at similar levels with respect to more mature fiber-pumped oscillators. The diode-pumped femtosecond oscillator presented here constitutes a key step towards a more accessible alternative to synchrotron-like infrared radiation, and is expected to accelerate research in laser spectroscopy and ultrafast infrared optics.Comment: 8 pages, 5 figure

Supercontinuum generation in the vacuum ultraviolet through dispersive-wave and soliton-plasma interaction in noble-gas-filled hollow-core photonic crystal fiber

We report on the generation of a three-octave-wide supercontinuum extending from the vacuum ultraviolet (VUV) to the near-infrared, spanning at least 113 to 1000 nm (i.e., 11 to 1.2 eV), in He-filled hollow-core kagome-style photonic crystal fiber. Numerical simulations confirm that the main mechanism is a novel and previously undiscovered interaction between dispersive-wave emission and plasma-induced blueshifted soliton recompression around the fiber zero dispersion frequency. The VUV part of the supercontinuum, which modeling shows to be coherent and possess a simple phase structure, has sufficient bandwidth to support single-cycle pulses of 500 attosecond duration. We also demonstrate, in the same system, the generation of narrower-band VUV pulses, through dispersive-wave emission, tunable from 120 to 200 nm with efficiencies exceeding 1% and VUV pulse energies in excess of 50 nJ.Comment: 7 pages, 5 figure

Reactivation of Epstein–Barr virus by a dual-responsive fluorescent EBNA1-targeting agent with Zn2+-chelating function

EBNA1 is the only Epstein–Barr virus (EBV) latent protein responsible for viral genome maintenance and is expressed in all EBV-infected cells. Zn2+ is essential for oligomerization of the functional EBNA1. We constructed an EBNA1 binding peptide with a Zn2+ chelator to create an EBNA1-specific inhibitor (ZRL5P4). ZRL5P4 by itself is sufficient to reactivate EBV from its latent infection. ZRL5P4 is able to emit unique responsive fluorescent signals once it binds with EBNA1 and a Zn2+ ion. ZRL5P4 can selectively disrupt the EBNA1 oligomerization and cause nasopharyngeal carcinoma (NPC) tumor shrinkage, possibly due to EBV lytic induction. Dicer1 seems essential for this lytic reactivation. As can been seen, EBNA1 is likely to maintain NPC cell survival by suppressing viral reactivation

Hsa-miRNA-765 as a key mediator for inhibiting growth, migration and invasion in fulvestrant-treated prostate cancer

Fulvestrant (ICI-182,780) has recently been shown to effectively suppress prostate cancer cell growth in vitro and in vivo. But it is unclear whether microRNAs play a role in regulating oncogene expression in fulvestrant-treated prostate cancer. Here, this study reports hsa-miR-765 as the first fulvestrant-driven, ERβ-regulated miRNA exhibiting significant tumor suppressor activities like fulvestrant, against prostate cancer cell growth via blockage of cell-cycle progression at the G2/M transition, and cell migration and invasion possibly via reduction of filopodia/intense stress-fiber formation. Fulvestrant was shown to upregulate hsa-miR-765 expression through recruitment of ERβ to the 5′-regulatory-region of hsa-miR-765. HMGA1, an oncogenic protein in prostate cancer, was identified as a downstream target of hsa-miR-765 and fulvestrant in cell-based experiments and a clinical study. Both the antiestrogen and the hsa-miR-765 mimic suppressed HMGA1 protein expression. In a neo-adjuvant study, levels of hsa-miR-765 were increased and HMGA1 expression was almost completely lost in prostate cancer specimens from patients treated with a single dose (250 mg) of fulvestrant 28 days before prostatectomy. These findings reveal a novel fulvestrant signaling cascade involving ERβ-mediated transcriptional upregulation of hsa-miR-765 that suppresses HMGA1 protein expression as part of the mechanism underlying the tumor suppressor action of fulvestrant in prostate cancer. © 2014 Leung et al

The Use of Computer-Assisted, Interactive Role-Play Simulation in Hong Kong

This paper reports feedback from both undergraduate and postgraduate students’ participation in Fish Bank, Ltd., a computerassisted, interactive role-playing simulation in which teams are to manage a fishing company to compete in the fishing industry. The survey focused on how students viewed computerassisted, interactive role-playing simulation as a learning tool for them and how they perceived that this type of role-playing simulation can actually help them understand the subject matter more in depth. Overall results are highly favorable at postgraduate level and favorable at undergraduate level respectively

How can Sweden’s “trash economy” be explained by international relations theories?

published_or_final_versionInternational and Public AffairsMasterMaster of International and Public Affair

Extracardiac Fontan Operation for Right Isomerism, Left-Sided IVC, and Apicocaval Juxtaposition

The patient is a five-year-old girl weighing 21 kg with right isomerism, right-sided superior vena cava (SVC), and left-sided inferior vena cava (IVC). The patient’s pulmonary venous confluence drained to the left atrium. She had a dominant right ventricle and double outlet right ventricle. A right-sided bilateral cavopulmonary connection had been performed four years prior. Surgeons planned for a Fontan completion. Preoperative cardiac catheterization showed good pulmonary vasculature, patent right side cavopulmonary connection, and left-sided IVC with apicocaval juxtaposition. For the ipsilateral method, the IVC conduit would be compressed by the spine, pulmonary venous confluence, and ventricle. For the contralateral method, the IVC conduit would not be compressed if there was adequate pericardial space between the pericardium and pulmonary venous confluence. First, cardiopulmonary bypass was established with ascending aorta, SVC, and left femoral vein cannulation. The left-sided IVC was identified and dissected out. The right pulmonary vein and pulmonary venous confluence was then dissected. The Gortex membrane between aorta and pulmonary artery, which was put in during the stage II operation, was dissected out. The Gortex membrane was put in to facilitate dissection between aorta and PA during the Fontan operation. After complete adhesiolysis, there was adequate pericardial space to accommodate the IVC conduit. On testing, the IVC conduit was not compressed by the ventricle or the spine. IVC conduit configuration was straight with gentle curvature and no acute kinking when placed with the contralateral method. The left-sided IVC was mobilized as low as possible to reduce angulation between the conduit and left-sided IVC after anastomosis. Next, a pulmonary arteriotomy was performed over the inferior aspect of the pulmonary artery. Superior anastomosis between the pulmonary artery and conduit was performed with a beating heart. The left-sided inferior vena cava was transected and the conduit was trimmed. Inferior anastomosis between the left-sided IVC and conduit was performed with an arrested heart. Next, 4 mm fenestration was made on the conduit. The cardiac end of the IVC stump was sutured around the fenestration. The heart resumed beating in sinus rhythm after the cross clamp was removed. The patient had an uneventful recovery. Upon her six-month follow up, the patient was well with good saturation. An echocardiogram showed good ventricular function and a patent IVC conduit.</p