Abstract:A secure communication network with quantum key distribution in a metropolitan area is reported. Six different QKD systems are integrated into a mesh-type network. GHz-clocked QKD links enable us to demonstrate the world-first secure TV conferencing over a distance of 45km. The network includes a commercial QKD product for long-term stable operation, and application interface to secure mobile phones. Detection of an eavesdropper, rerouting into a secure path, and key relay via trusted nodes are demonstrated in this network. ©2011 Optical Society of AmericaOCIS codes: (270.5568) Quantum cryptography; (060.5565) Quantum communications. References and links1. N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, "Quantum cryptography," Rev. Mod. Phys. 74(1), 145-195 (2002). 2. V. Scarani, H. Bechmann-Pasquinucci, N. J. Cerf, M. Dušek, N. N. Lütkenhaus, and M. Peev, "The security of practical quantum key distribution," Rev. Mod. Phys. 81(3), 1301-1350 (2009

Embryonic development of multilineage hematopoiesis requires the precisely regulated expression of lineage-specific transcription factors, including AML-1 (encoded by Runx1; also known as CBFA-2 or PEBP-2alphaB). In vitro studies and findings in human diseases, including leukemias, myelodysplastic syndromes and familial platelet disorder with predisposition to acute myeloid leukemia (AML), suggest that AML-1 has a pivotal role in adult hematopoiesis. However, this role has not been fully uncovered in vivo because of the embryonic lethality of Runx1 knockout in mice. Here we assess the requirement of AML-1/Runx1 in adult hematopoiesis using an inducible gene-targeting method. In the absence of AML-1, hematopoietic progenitors were fully maintained with normal myeloid cell development. However, AML-1-deficient bone marrow showed inhibition of megakaryocytic maturation, increased hematopoietic progenitor cells and defective T- and B-lymphocyte development. AML-1 is thus required for maturation of megakaryocytes and differentiation of T and B cells, but not for maintenance of hematopoietic stem cells (HSCs) in adult hematopoiesis.

The Notch genes play a key role in cellular differentiation. The significance of Notch1 during thymocyte development is well characterized, but the function of Notch2 is poorly understood. Here we demonstrate that Notch2 but no other Notch family member is preferentially expressed in mature B cells and that conditionally targeted deletion of Notch2 results in the defect of marginal zone B (MZB) cells and their presumed precursors, CD1d(hi) fraction of type 2 transitional B cells. Among Notch target genes, the expression level of Deltex1 is prominent in MZB cells and strictly dependent on that of Notch2, suggesting that Deltex1 may play a role in MZB cell differentiation.

The chromosomal translocations found in acute myelogenous leukemia (AML) generate oncogenic fusion transcription factors with aberrant transcriptional regulatory properties. Although therapeutic targeting of most leukemia fusion proteins remains elusive, the posttranslational modifications that control their function could be targetable. We found that AML1-ETO, the fusion protein generated by the t(8;21) translocation, is acetylated by the transcriptional coactivator p300 in leukemia cells isolated from t(8;21) AML patients, and that this acetylation is essential for its self-renewal–promoting effects in human cord blood CD34+ cells and its leukemogenicity in mouse models. Inhibition of p300 abrogates the acetylation of AML1-ETO and impairs its ability to promote leukemic transformation. Thus, lysine acetyltransferases represent a potential therapeutic target in AML.

Fibreoptic tracheal intubation is a useful technique in patients whose tracheas are dif®cult to intubate. 66 69 However, there are two major dif®culties with this technique. The ®rst is location of the glottis and insertion of a ®brescope into the trachea. Induction of general anaesthesia (with or without neuromuscular block) causes the soft palate, tongue and epiglottis to approximate to the posterior pharyngeal wall, 64 and thus little air space is left in the oropharynx for manoeuvring the tip of the ®brescope to locate the glottis. 58 The second dif®culty is insertion of a tube over the ®brescope into the trachea. There have been reports of failed tracheal intubation despite successful insertion of a ®brescope into the trachea. 67 89 To solve the ®rst dif®culty, several manoeuvres (such as thrusting the jaw forward, extension of the head, or traction of the tongue) have been proposed, and airway intubators (such as the Berman, 17 Ovassapian 66 and Williams 87 ) have been developed. In addition, there have been comprehensive articles discussing effective ways of teaching ®brescopy. 58 66 69 85 In contrast, there have been no textbooks or reviews which comprehensively deal with the second dif®culty, of advancing a tracheal tube over a ®brescope. Therefore, the main aim of this review article is to analyse the incidence of, causes of and possible solution to, the dif®culty in advancing a tube over a ®brescope into the trachea. Problems associated with dif®cult intubation over a ®brescopeDif®culty in ®breoptic intubation is associated with two major problems. The ®rst is apnoea. Time taken to intubate the trachea, and thus the duration of apnoea, is generally markedly longer for ®breoptic intubation than intubation using a laryngoscope. 74 80±82 As a consequence, stress responses, such as the increase in the heart rate and blood pressure, are more likely to be greater during ®breoptic intubation. 80±82 If apnoea continues unduly, the patient may become hypoxic. 56 It is particularly awkward if, after successful insertion of a ®brescope into the trachea despite considerable dif®culty in a patient with a dif®cult airway, it is still dif®cult to advance a tube over the scope into the trachea and the arterial haemoglobin oxygen saturation starts to decrease.The second problem associated with dif®cult ®breoptic intubation is damage to the upper airway. Repeated attempts at inserting a ®brescope into the trachea and advancing a tube over the scope increase the risk of injury to the larynx and surrounding tissues, leading to bleeding from, or oedema of, the tissues. Although rare, complete airway obstruction could occur during attempts at ®breoptic intubation even when the patient is not anaesthetized. 18 59 What tends to be ignored is that at no time during insertion of a tracheal tube over a ®brescope can the tip of the tube be seen directly. Therefore, a tracheal tube should be advanced over a ®brescope with great caution, particularly in patients with pathological changes to the glottis or surrounding tissues. 44 ...