4,670 research outputs found
Unbroken supersymmetry in the Aharonov-Casher effect
We consider the problem of the bound states of a spin 1/2 chargless particle
in a given Aharonov-Casher configuration. To this end we recast the description
of the system in a supersymmetric form. Then the basic physical requirements
for unbroken supersymmetry are established. We comment on the possibility of
neutron confinement in this system
Supracricoid Partial Laryngectomy: Oncological and Functional Outcomes
Introduction In the present study, we have reviewed the outcomes of patients with supracricoid partial laryngectomy (SCPL) in our institution. Our results show that SCPL is a well-tolerated procedure with generally good functional outcomes for patients with advanced laryngeal cancer. Objective We analyzed the oncological and functional results of a cohort of 35 patients who had undergone SCPL, and we highlighted the complications, identified the overall and disease-free survivals, demonstrating that the reconstructive laryngectomy guarantees the oncological safety and reproducibility of the oncological results, preserving the laryngeal functions and promoting an improvement in the patient's quality of life, favoring communication and interpersonal relationships. Methods Between 2010 and 2018, 35 patients underwent SCPL for primary and recurrent laryngeal squamous cell carcinomas, and they were divided into two subgroups: in 16 cases, the cricohyoidoepiglottopexy according to the Mayer-Piquet technique was performed, while the remaining 19 cases were submitted to the cricohyoidopexy according to the Labayle technique. In addition to evaluating the oncological results of patients undergoing reconstructive laryngectomy, the present study also aimed to evaluate the functionality of the residual larynx and the quality of life. Results The overall and disease-free survivals were of 83% and 76.3% respectively. All patients were able to swallow. The nasogastric tube was removed after a mean period of 21.8 days (range: 14 to 28 days). The mean decannulation time was of 23.4 days after surgery (range: 15 to 36 days). Conclusion The curves for the overall and disease-free survivals show that SCPL can guarantee oncological safety comparable to that of total laryngectomies in diseases in the intermediate stage and in carefully-selected advanced stages
Noncommutative quantum mechanics and the Aharonov-Casher effect
In this work a new method is developed to investigate the Aharonov-Casher
effect in a noncommutative space. It is shown that the holonomy receives
non-trivial kinematical corrections.Comment: 8 pages, Plain Tex, to appear in Eur. Phys. J.
Herbicidal potential of ophiobolins produced by Drechslera gigantea
Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds. © 2006 American Chemical Society
Inuloxin E, a New Seco-Eudesmanolide Isolated from Dittrichia viscosa, Stimulating Orobanche cumana Seed Germination
A new sesquiterpenoid belonging to the subgroup seco-eudesmanolides and named inuloxin E was isolated from Dittrichia viscosa, together with the already known sesquiterpenoids inuloxins A–D and -costic acid. Inuloxin E was characterized by spectroscopic data (essentially NMR and ESIMS) as 3-methylene-6-(1-methyl-4-oxo-pentyl)-3a,4,7,7a-tetrahydro-3H-benzofuran-2-one. Its relative configuration was determined by comparison with the closely related inuloxin D and chemical
conversion of inuloxin E into inuloxin D and by the observed significant correlation in the NOESY spectrum. Both inuloxins D and E induced germination of the parasitic weed Orobanche cumana, but were inactive on the seeds of Orobanche minor and Phelipanche ramosa. The germination activity of some hemisynthetic esters of inuloxin D was also investigated
Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis
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Ophiobolin E and 8-epi-ophiobolin J produced by Drechslera gigantea, a potential mycoherbicide of weedy grasses
Drechslera gigantea, a fungal pathogen isolated from large crabgrass (Digitaria sanguinalis) and proposed as a potential mycoherbicide of grass weeds, produces phytotoxic metabolites in liquid and solid cultures. Ophiobolin A and three minor ophiobolins i.e., 6-epi-ophiobolin A, 3-anhydro-6-epi-ophiobolin A and ophiobolin I were obtained from the liquid culture broths. Interestingly and unexpectedly, ophiobolins also appeared in cultures of this fungus and they were isolated together with the known ophiobolins B and J, and designed as ophiobolin E and 8-epi-ophiobolin J. They were characterized using essentially spectroscopic methods. It is noteworthy that D. gigantea produces such a plethora of bioactive organic substances. Some structure-activity relationship results are also discussed in this report. © 2006 Elsevier Ltd. All rights reserved
Sporadic Porphyria Cutanea Tarda in a Patient with Multiple Sclerosis Treated with Interferon Beta 1-a Therapy: A Case Report
Muon Radiography Investigations in Boreholes with a Newly Designed Cylindrical Detector
Muons are constantly produced in cosmic-rays and reach the Earth surface with a flux of about 160 particles per second per square meter. The abundance of muons with respect to other cosmic particles and their capability to cross dense materials with low absorption rate allow them to be exploited for large scale geological or human-made object imaging. Muon radiography is based on similar principles as X-ray radiography, measuring the surviving rate of muons escaping the target and relating it to the mass distribution inside the object. In the course of decades, after the first application in 1955, the methodology has been applied in several different fields. Muography allows us to measure the internal density distribution of the investigated object, or to simply highlight the presence of void regions by observing any excess of muons. Most of these applications require the detector to be installed below the rock being probed. In case that possible installation sites are not easily accessible by people, common instrumentation cannot be installed. A novel borehole cylindrical detector for muon radiography has been recently developed to deal with these conditions. It has been realized with a cylindrical geometry to fit typical borehole dimensions. Its design maximizes the geometrical acceptance, minimizing the dead spaces by the use of arc-shaped scintillators. The details of the construction and preliminary results of the first usage are described in this paper. © 2022 by the authors
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