224 research outputs found
Metric Algebroid and Poisson-Lie T-duality in DFT
In this article we investigate the gauge invariance and duality properties of
DFT based on a metric algebroid formulation given previously in [1]. The
derivation of the general action given in this paper does not employ the
section condition. Instead, the action is determined by requiring a pre-Bianchi
identity on the structure functions of the metric algebroid and also for the
dilaton flux. The pre-Bianchi identity is also a sufficient condition for a
generalized Lichnerowicz formula to hold. The reduction to the D-dimensional
space is achieved by a dimensional reduction of the fluctuations. The result
contains the theory on the group manifold, or the theory extending to the GSE,
depending on the chosen background. As an explicit example we apply our
formulation to the Poisson-Lie T-duality in the effective theory on a group
manifold. It is formulated as a 2D-dimensional diffeomorphism including the
fluctuations.Comment: 61 page
Physiological and developmental mechanism of regressive molt in a damp-wood termite Hodotermopsis sjostedti
In some species of termites, a part of nymphs can undergo “regressive molt,” in which imaginal characters such as wing buds and body size are reduced. The function of regressive molt is thought to be a regulatory mechanism controlling caste composition in a colony. However, little is known about the physiological and developmental processes resulting in the regressive molt. In this study, therefore, regressive molt was observed in a damp-wood termite Hodotermopsis sjostedti, under rearing conditions, and histological and morphological observations during regressive molt (especially the reduction of wing buds) were carried out. It was found that nymphs with wing buds were classified into three morphological types. Almost all nymphs with swollen wing buds (Type 1) differentiated into alates, while nymphs with pigmented wing buds (Type 2) or with flat wing buds (Type 3) underwent regressive molts to become pseudergates (workers). Through the regressive molt, a part of nymphs differentiated into presoldiers or neotenic reproductives. Histological observations showed that, in nymphs undergoing regressive molt, epithelial tissue of wing buds was degenerated. Consistently, real-time qPCR analyses revealed that, apoptosis-related factors were up-regulated in the thoracic parts of Type 3 nymphs. Furthermore, expression analyses on developmental and endocrine factors by real-time qPCR were carried out, showing that, the expression pattern of these factors in regressive molt is nearly identical to that in stationary molt. These results suggest that the differentiation fate of nymph is determined during the intermolt period before the differentiation into Type 1 or Type 2/3 nymphs. The regressive molt itself would be almost identical to stationary molt
Perihilar or (Hilar) Cholangiocarcinoma: Interventional to Surgical Management
Peri-hilar cholangiocarcinoma (PHC) or hilar cholangiocarcinoma (HCCA) characterizes a critical effort to assess significantly sick patients. The existing scenery and proof to the diagnosis and treatments for hilar cholangiocarcinoma are improving day by day. Patients with HCCA encounter numerous obstacles in acquiring efficient therapies. The condition is uncommon, and the majority patients don’t have any distinct risk factors, doing selection process inadequate. The initial signs and symptoms in many cases are non-specific, and in many patients the tumors are not resectable because of involvement of the perihilar structures. MRI with MRCP offers further information about the extent of biliary involvement. Furthermore, endoscopic stenting and percutaneous drain could be useful for intricate hilar strictures. Surgical resections with negative margins are related to good likelihood of survival for patients representing with HCCA. Regardless of the accessibility of curative treatment strategies such as operative resection and liver transplantation, most sufferers with HCCA shows with repeated, metastases or locally advanced disease with a poor prognosis. Within this chapter, we have tried to elaborate the modalities of treatment from intervention to surgical approach for HCCA
Stabilization of a honeycomb lattice of IrO octahedra in superlattices with ilmenite-type MnTiO
In the quest for quantum spin liquids, thin films are expected to open the
way for the control of intricate magnetic interactions in actual materials by
exploiting epitaxial strain and two-dimensionality. However, materials
compatible with conventional thin-film growth methods have largely remained
undeveloped. As a promising candidate towards the materialization of quantum
spin liquids in thin films, we here present a robust ilmenite-type oxide with a
honeycomb lattice of edge-sharing IrO octahedra artificially stabilized by
superlattice formation with an ilmenite-type antiferromagnetic oxide MnTiO.
The stabilized sub-unit-cell-thick Mn-Ir-O layer is isostructural to MnTiO,
having the atomic arrangement corresponding to ilmenite-type MnTiO not
discovered yet. By spin Hall magnetoresistance measurements, we found that
antiferromagnetic ordering in the ilmenite Mn sublattice is suppressed by
modified magnetic interactions in the MnO planes via the IrO planes.
These findings lay the foundation for the creation of two-dimensional Kitaev
candidate materials, accelerating the discovery of exotic physics and
applications specific to quantum spin liquids
Cystic Artery Variations and Associated Vascular Complications in Laparoscopic Cholecystectomy
Substantial knowledge of the arterial supply and its anatomical variations of the gall bladder and liver are important in all the hepatobiliary surgical procedures. The arterial supply of gallbladder called cystic artery (CA) is a vital structure required to get ligated or clipped in the path of laparoscopic cholecystectomy. The possible concerns like intra-operative bleeding or adjoining accidental injuries will almost always be focused on the research consisting of dissection and clipping with cystic artery. Pseudoaneurysm of the cystic artery has additionally been belonging to the presence of acute cholecystitis or pancreatitis. An original supply of CA is usually assessed depending on the existence of hepatic artery variants. Laparoscopic cholecystectomy is really a recent and arduous noninvasive procedure and might even result in substantial unintended effects possibly iatrogenic or in the form of post-procedural complications. The perfect knowledge of anatomy in addition to feasible variation of cystic artery is mandatory. An efficient operative strategy and consciousness are probably the key components with all the results and marginal likelihood of complications, which often can be ultimately attainable. Within this chapter, we have attempted to explore some variations of cystic artery, complications and management
Nickel Carbide Nanoparticle Catalyst for Selective Hydrogenation of Nitriles to Primary Amines
Yamaguchi S., Kiyohira D., Tada K., et al. Nickel Carbide Nanoparticle Catalyst for Selective Hydrogenation of Nitriles to Primary Amines. Chemistry - A European Journal 30, e202303573 (2024); https://doi.org/10.1002/chem.202303573.Despite its unique physicochemical properties, the catalytic application of nickel carbide (Ni3C) in organic synthesis is rare. In this study, we report well-defined nanocrystalline Ni3C (nano-Ni3C) as a highly active catalyst for the selective hydrogenation of nitriles to primary amines. The activity of the aluminum-oxide-supported nano-Ni3C (nano-Ni3C/Al2O3) catalyst surpasses that of Ni nanoparticles. Various aromatic and aliphatic nitriles and dinitriles were successfully converted to the corresponding primary amines under mild conditions (1 bar H2 pressure). Furthermore, the nano-Ni3C/Al2O3 catalyst was reusable and applicable to gram-scale experiments. Density functional theory calculations suggest the formation of polar hydrogen species on the nano-Ni3C surface, which were attributed to the high activity of nano-Ni3C towards nitrile hydrogenation. This study demonstrates the utility of metal carbides as a new class of catalysts for liquid-phase organic reactions
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