1,359 research outputs found
Perpendicular momentum injection by lower hybrid wave in a tokamak
The injection of lower hybrid waves for current drive into a tokamak affects
the profile of intrinsic rotation. In this article, the momentum deposition by
the lower hybrid wave on the electrons is studied. Due to the increase in the
poloidal momentum of the wave as it propagates into the tokamak, the parallel
momentum of the wave increases considerably. The change of the perpendicular
momentum of the wave is such that the toroidal angular momentum of the wave is
conserved. If the perpendicular momentum transfer via electron Landau damping
is ignored, the transfer of the toroidal angular momentum to the plasma will be
larger than the injected toroidal angular momentum. A proper quasilinear
treatment proves that both perpendicular and parallel momentum are transferred
to the electrons. The toroidal angular momentum of the electrons is then
transferred to the ions via different mechanisms for the parallel and
perpendicular momentum. The perpendicular momentum is transferred to ions
through an outward radial electron pinch, while the parallel momentum is
transferred through collisions.Comment: 22 pages, 4 figure
A novel developmental encephalopathy with epilepsy and hyperkinetic movement disorders associated with a deletion of the sodium channel gene cluster on chromosome 2q24.3
We reported a 21 months-old boy with a complex epilepsy phenotype, developmental delay, and hyperkinetic movement disorders, associated with a deletion of the whole sodium channel gene cluster. Whether this unusual phenotype results from leading to haploinsufficiency of either SCN1A or SCN2A, or the combination of both, remains subject of speculation. However, nobody of the numerous reported patients with truncating mutations in SCN1A has ever manifested such a clinical phenotyp
3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds
Aim: To develop a methodology for producing patient-specific scaffolds that mimic the annulus fibrosus (AF) of the human intervertebral disc (IVD) by means of combining magnetic resonance imaging (MRI) and 3D bioprinting. Methods: In order to obtain the AF 3D model from patientĂą s volumetric MRI dataset, the RheumaSCORE segmentation software was used. Polycaprolactone scaffolds with three different internal architectures were fabricated by 3D bioprinting, and characterized by micro-computed tomography.
Results: The demonstrated methodology of a geometry reconstruction pipeline enabled to successfully obtain an accurate AF model and 3D print patient-specific scaffolds with different internal architectures.
Conclusion: The results guide us towards patient-specific IVD tissue engineering as demonstrated a way of manufacturing personalized scaffolds using patient's MRI data.The authors would like to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAPEXPL/BBB-ECT/0050/2014),
funded in the Framework of the âInternational Collaboratory for Emerging Technologies, CoLabâ, UT
justin|Portugal Program. FCT is also acknowledged for the PhD scholarship attributed to IF Cengiz (SFRH/
BD/99555/2014) and the financial support provided to J Silva-Correia (SFRH/BPD/100590/2014 and IF/00115/2015).
JM Oliveira also thanks the FCT for the funds provided under the program Investigador FCT (IF/00423/2012 and IF/01285/2015). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.info:eu-repo/semantics/publishedVersio
Surveillance of colonization and infection with Staphylococcus aureus susceptible or resistant to methicillin in a community skilled-nursing facility
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen in acute care hospitals and long-term care facilities. Few studies have been reported in private skilled nursing facilities (SNFs) not experiencing outbreaks of infections caused by MRSA. METHODS: From a 149-bed SNF with no outbreaks, we report a 1-year prospective surveillance study of S. aureus colonization and infection, with focus on S. aureus phenotypes, both methicillin susceptible (MS) and methicillin resistant (MR). Nasal and stool or rectal screening cultures were done on admission, and all patients underwent screening on at least a quarterly basis for 1 year. RESULTS: Overall, 35% of patients were colonized at least once with S. aureus, (72% MS, 25% MR, and 3% mixed phenotypes), 94% of the MRSA were ciprofloxacin resistant. Nasal colonization with any S. aureus was more frequent, but 13% of patients had positive results only in rectal specimens. Twenty-one percent of the newly admitted and 15% of continuing patients acquired colonization during their stay in the SNE Colonization was transient or persistent, persisted longer in the nares compared with colonization in rectal specimens, and was more stable for methicillin-susceptible S. aureus. Nine percent of patients had development of infection with S. aureus. There was no indication that MRSA colonization led to more infections than methicillin-susceptible S. aureus. Of the 13 infected patients in whom cultures had previously been obtained, seven (54%) had been colonized by the same phenotype strains. CONCLUSIONS: In this private SNF, endemic S. aureus infections occur at a low frequency, reflecting a moderate level of colonization with S. aureus. However, a trend showing gradual increases in frequencies of colonization and infection is of concern and suggests that in this SNF, future intervention could become warranted
Farnesyltransferase inhibitors and human malignant pleural mesothelioma: a first-step comparative translational study.
It is known that the potential clinical use of farnesyltransferase
inhibitors (FTI) could be expanded to include
cancers harboring activated receptor tyrosine kinases.
Approximately 70% of malignant pleural mesotheliomas
(MPM) overexpress epidermal growth factor receptors
(EGFR) and a subset express both EGFR and transforming
growth factor A (TGF-A), suggesting an autocrine role for
EGFR in MPM. We checked on MPM cells (10 human cell
lines, 11 primary cultures obtained by human biopsies, and
7 short-term normal mesothelial cell cultures) concerning the
following: (a) the relative overexpression of EGFR (Western
blotting, flow cytometry, immunohistochemistry), (b) the
relative expression of EGFR ligands (EGF, amphiregulin,
TGF-A, ELISA), (c) the relative increase of the activated
form of Ras (Ras-bound GTP) after EGF stimulation (Ras
activation assay), (d) the efficacy of five different FTIs (HDJ2
prenylation, cell cytotoxicity, and apoptosis using ApopTag
and gel ladder). EGFR was overexpressed in MPM cells
compared with normal pleural mesothelial cells in equivalent
levels as in non\u2013small cell lung cancer cells A549.
MPM cells constitutively expressed EGFR ligands; however,
Ras activation was attenuated at high EGF concentrations
(100 ng/mL). Growth of MPM cells was substantially not
affected by treatment with different FTIs (SCH66336, BMS-
214662, R115777, RPR-115135, and Manumycin). Among
these, BMS-214662 was the only one moderately active.
BMS-214662 triggered apoptosis in a small fraction of cells
(not higher than 30%) that was paralleled by a slight
decrease in the levels of TGF-A secreted by treated MPM
cells. Our data highlighted the concept that the same
signaling pathway can be regulated in different ways and
these regulations can differ between different cells of
different origin
Genetic susceptibility to malignant pleural mesothelioma and other asbestos-associated diseases.
Exposure to asbestos fibers is a major risk factor for malignant pleuralmesothelioma (MPM), lung cancer,
and other non-neoplastic conditions, such as asbestosis and pleural plaques. However, in the last decade
many studies have shown that polymorphism in the genes involved in xenobiotic and oxidative
metabolism or in DNA repair processes may play an important role in the etiology and pathogenesis of
these diseases. To evaluate the association between diseases linked to asbestos and genetic variability we
performed a review of studies on this topic included in the PubMed database. One hundred fifty-nine
citations were retrieved; 24 of them met the inclusion criteria and were evaluated in the review. The most
commonly studied GSTM1 polymorphism showed for all asbestos-linked diseases an increased risk in
association with the null genotype, possibly linked to its role in the conjugation of reactive oxygen
species. Studies focused on GSTT1 null and SOD2 Ala16Val polymorphisms gave conflicting results, while
promising results came from studies on a1-antitrypsin in asbestosis and MPO in lung cancer. Among
genetic polymorphisms associated to the risk of MPM, the GSTM1 null genotype and two variant alleles of
XRCC1 and XRCC3 showed increased risks in a subset of studies. Results for the NAT2 acetylator status,
SOD2 polymorphism and EPHX activity were conflicting. Major limitations in the study design, including
the small size of study groups, affected the reliability of these studies. Technical improvements such as
the use of high-throughput techniques will help to identify molecular pathways regulated by candidate
genes
A Value-Based Approach to Increase Breast Cancer Screening and Health-Directed Behaviors among American Indian Women
American Indian/Alaska Native (AI/AN) women have the lowest cancer-screening rate of any ethnic or racial group; AI/AN women in all regions are less likely than non-Hispanic white women to be diagnosed with localized breast cancer; and those AI/AN women presenting with breast cancer have the lowest 5-year survival rate compared to other ethnic groups. This study found that cultural beliefs are more of a factor in mammography screening behavior than other barriers such as access; and that a more holistic educational intervention designed by AI/AN women prompted individual intent and actions to seek mammograms among AI/AN women >40 and to change unhealthy eating and sedentary lifestyles
- âŠ