1,878 research outputs found
On Space Mapping Techniques for Microwave Filter Tuning
[EN] Space mapping (SM) and aggressive SM (ASM) techniques are widely used in the synthesis and design of microwave filters. Their popularity stems from the inherent simplicity of the procedures and from their effectiveness. The objective of this article is to extend the state of the art of these techniques by discussing how they can also be used very effectively to tune microwave filters. In addition to the theory, the successful tuning of a six-pole inductive waveguide filter is discussed in detail, thereby fully validating the proposed SM techniques.This work was supported by funds from the "La Caixa" Foundation (Code: B004442) and Agencia Estatal de Investigacion (AEI) and Union Europea through Fondo Europeo de Desarrollo Regional-FEDER-"Una manera de hacer Europa" (AEI/FEDER, UE), under Research Project TEC2016-75934-C4-1-RMelgarejo-Lermas, JC.; Ossorio-García, J.; Cogollos, S.; Guglielmi, M.; Boria Esbert, VE.; Bandler, JW. (2019). On Space Mapping Techniques for Microwave Filter Tuning. IEEE Transactions on Microwave Theory and Techniques. 67(12):4860-4870. https://doi.org/10.1109/TMTT.2019.2944361S48604870671
Circadian rhythm of hepatic cytosolic and nuclear estrogen receptors
The distribution of estrogen receptor between the cytosolic and nuclear compartments were evaluated in liver of male rats to determine whether a circadian rhythm exists. Cytosolic receptor reached a maximum level at 400 hours and a minimum at 2000 and 2400 hr. Nuclear receptor reached a maximum level at 800 hr and was lowest at 1600 and 2000 hr. Serum estradiol levels were also highest at 800 hr and lowest at 1600 hr. The variations in cytosolic and nuclear receptors are not reciprocal; in fact, the overall content of receptor in the liver is not constant and also displays a circadian rhythm. © 1986 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
Technical challenges to surgical clipping of aneurysmal regrowth with coil herniation following endovascular treatment – a case report
In recent years, technical developments have made endovascular procedures attractive therapeutic options and enabled the endovascular surgeon to redefine the management of cerebral aneurysms. However, as the number of aneurysms undergoing endovascular therapy has grown, so has the number of patients with incompletely treated aneurysms who are presenting for further management. In cases of failure of endovascular treatment caused by either incomplete occlusion or regrowth of the aneurysm, a complementary treatment is often necessary. Surgical treatment of these patients is challenging. We present a case of a ruptured posterior cerebral artery aneurysm treated initially with endovascular coiling that left behind significant residual aneurysmal sac. Regrowth of the aneurysm documented on follow-up was treated surgically. At surgery, the coil was found to have herniated through the aneurysmal sac into the subarachnoid space, and the aneurysm was successfully clipped without removing the coils. We review the regrowth of aneurysms following endovascular therapy and potential problems and challenges of surgically managing these lesions
Characterization of a trimeric light-harvesting complex in the diatom Phaeodactylum tricornutum built of FcpA and FcpE proteins
Fucoxanthin chlorophyll proteins (Fcps), the light-harvesting antennas of heterokont algae, are encoded by a multigene family and are highly similar with respect to their molecular masses as well as to their pigmentation, making it difficult to purify single Fcps. In this study, a hexa-histidine tag was genetically added to the C-terminus of the FcpA protein of the pennate diatom Phaeodactylum tricornutum. A transgenic strain expressing the recombinant His-tagged FcpA protein in addition to the endogenous wild type Fcps was created. This strategy allowed, for the first time, the purification of a specific, stable trimeric Fcp complex. In addition, a pool of various trimeric Fcps was also purified from the wild-type cells using sucrose density gradient ultracentrifugation and gel filtration. In both the His-tagged and the wild-type Fcps, excitation energy coupling between fucoxanthin and chlorophyll a was intact and the existence of a chlorophyll a/fucoxanthin excitonic dimer was demonstrated using circular dichroism spectroscopy. Mass spectrometric analyses of the trimeric His-tagged complex indicated that it is composed of FcpA and FcpE polypeptides. It is confirmed here that a trimer is the basic organizational unit of Fcps in P. tricornutum. From circular dichroism spectra, it is proposed that the organization of the pigments on the polypeptide backbone of Fcps is a conserved feature in the case of chlorophyll a/c containing algae
CurlySMILES: a chemical language to customize and annotate encodings of molecular and nanodevice structures
CurlySMILES is a chemical line notation which extends SMILES with annotations for storage, retrieval and modeling of interlinked, coordinated, assembled and adsorbed molecules in supramolecular structures and nanodevices. Annotations are enclosed in curly braces and anchored to an atomic node or at the end of the molecular graph depending on the annotation type. CurlySMILES includes predefined annotations for stereogenicity, electron delocalization charges, extra-molecular interactions and connectivity, surface attachment, solutions, and crystal structures and allows extensions for domain-specific annotations. CurlySMILES provides a shorthand format to encode molecules with repetitive substructural parts or motifs such as monomer units in macromolecules and amino acids in peptide chains. CurlySMILES further accommodates special formats for non-molecular materials that are commonly denoted by composition of atoms or substructures rather than complete atom connectivity
Neutrino hierarchy from CP-blind observables with high density magnetized detectors
High density magnetized detectors are well suited to exploit the outstanding
purity and intensities of novel neutrino sources like Neutrino Factories and
Beta Beams. They can also provide independent measurements of leptonic mixing
parameters through the observation of atmospheric muon-neutrinos. In this
paper, we discuss the combination of these observables from a multi-kton iron
detector and a high energy Beta Beam; in particular, we demonstrate that even
with moderate detector granularities the neutrino mass hierarchy can be
determined for values greater than 4.Comment: 16 pages, 7 figures. Added a new section discussing systematic errors
(sec 5.2); sec.5.1 and 4 have been extended. Version to appear in EPJ
Topical Review on "Beta-beams"
Neutrino physics is traversing an exciting period, after the important
discovery that neutrinos are massive particles, that has implications from
high-energy physics to cosmology. A new method for the production of intense
and pure neutrino beams has been proposed recently: the ``beta-beam''. It
exploits boosted radioactive ions decaying through beta-decay. This novel
concept has been the starting point for a new possible future facility. Its
main goal is to address the crucial issue of the existence of CP violation in
the lepton sector. Here we review the status and the recent developments with
beta-beams. We discuss the original, the medium and high-energy scenarios as
well as mono-chromatic neutrino beams produced through ion electron-capture.
The issue of the degeneracies is mentioned. An overview of low energy
beta-beams is also presented. These beams can be used to perform experiments of
interest for nuclear structure, for the study of fundamental interactions and
for nuclear astrophysics.Comment: Topical Review for Journal of Physics G: Nuclear and Particle
Physics, published version, minor corrections, references adde
Evaluation of the ACS NSQIP Surgical Risk Calculator in Elderly Patients Undergoing Hepatectomy for Hepatocellular Carcinoma
Background: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) surgical risk calculator (SRC) aims to help predict patient-specific risk for morbidity and mortality. The performance of the SRC among an elderly population undergoing curative-intent hepatectomy for hepatocellular carcinoma (HCC) remains unknown.
Methods: Patients > 70 years of age who underwent hepatectomy for HCC between 1998 and 2017 were identified using a multi-institutional international database. To estimate the performance of SRC, 12 observed postoperative outcomes were compared with median SRC-predicted risk, and C-statistics and Brier scores were calculated.
Results: Among 500 patients, median age was 75 years (IQR 72-78). Most patients (n = 324, 64.8%) underwent a minor hepatectomy, while 35.2% underwent a major hepatectomy. The observed incidence of venous thromboembolism (VTE) (3.2%) and renal failure (RF) (4.4%) exceeded the median predicted risk (VTE, 1.8%; IQR 1.5-3.1 and RF, 1.0%; IQR 0.5-2.0). In contrast, the observed incidence of 30-day readmission (7.0%) and non-home discharge (2.5%) was lower than median-predicted risk (30-day readmission, 9.4%; IQR 7.4-12.8 and non-home discharge, 5.7%; IQR 3.3-11.7). Only 57.8% and 71.2% of patients who experienced readmission (C-statistic, 0.578; 95%CI 0.468-0.688) or mortality (C-statistic, 0.712; 95%CI 0.508-0.917) were correctly identified by the model.
Conclusion: Among elderly patients undergoing hepatectomy for HCC, the SRC underestimated the risk of complications such as VTE and RF, while being no better than chance in estimating the risk of readmission. The ACS SRC has limited clinical applicability in estimating perioperative risk among elderly patients being considered for hepatic resection of HCC.info:eu-repo/semantics/publishedVersio
Collateral Circulation and Outcome in Atherosclerotic Versus Cardioembolic Cerebral Large Vessel Occlusion
Background and Purpose- Due to chronic hypoperfusion, cervical atherosclerosis may promote cerebral collateral circulation. We hypothesized that patients with ischemic stroke due to cervical carotid atherosclerosis have a more extensive collateral circulation and better outcomes than patients with cardioembolism. We tested this hypothesis in a population of patients who underwent endovascular treatment for large vessel occlusion. Methods- From the MR-CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), we selected consecutive adult endovascular treatment patients (March 2014 to June 2016) with acute ischemic stroke due to anterior circulation large vessel occlusion and compared patients with cervical carotid artery stenosis >50% to those with cardioembolic etiology. The primary outcome was collateral score, graded on a 4-point scale. Secondary outcomes included the modified Rankin Scale (mRS) score and mortality at 90 days. We performed multivariable regression analyses and adjusted for potential confounders. Results- Of 1627 patients in the Registry, 190 patients with cervical carotid atherosclerosis and 476 with cardioembolism were included. Patients with cervical carotid atherosclerosis were younger (median 69 versus 76 years, P<0.001), more often male (67% versus 47%, P<0.001), more often had an internal carotid artery terminus occlusion (33% versus 18%, P<0.001), and a lower prestroke mRS (mRS score, 0-2; 96% versus 85%, P<0.001), than patients with cardioembolism. Stroke due to cervical carotid atherosclerosis was associated with higher collateral score (adjusted common odds ratio, 1.67 [95% CI, 1.17-2.39]) and lower median mRS at 90 days (adjusted common odds ratio, 1.45 [95% CI, 1.03-2.05]) compared with cardioembolic stroke. There was no statistically significant difference in proportion of mRS 0-2 (aOR, 1.36 [95% CI, 0.90-2.07]) or mortality at 90 days (aOR, 0.80 [95% CI, 0.48-1.34]). Conclusions- Patients with stroke due to cervical carotid atherosclerosis had a more extensive cerebral collateral circulation and a slightly better median mRS at 90 days than patients with cardioembolic stroke
The taming of recurrences in computability logic through cirquent calculus, Part I
This paper constructs a cirquent calculus system and proves its soundness and
completeness with respect to the semantics of computability logic (see
http://www.cis.upenn.edu/~giorgi/cl.html). The logical vocabulary of the system
consists of negation, parallel conjunction, parallel disjunction, branching
recurrence, and branching corecurrence. The article is published in two parts,
with (the present) Part I containing preliminaries and a soundness proof, and
(the forthcoming) Part II containing a completeness proof
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