12,069 research outputs found
Increase of the Energy Necessary to Probe Ultraviolet Theories Due to the Presence of a Strong Magnetic Field
We use the gauge gravity correspondence to study the renormalization group
flow of a double trace fermionic operator in a quark-gluon plasma subject to
the influence of a strong magnetic field and compare it with the results for
the case at zero temperature and no magnetic field, where the flow between two
fixed points is observed. Our results show that the energy necessary to access
the physics of the ultraviolet theory increases with the intensity of the
magnetic field under which the processes happen. We provide arguments to
support that this increase is scheme independent, and to exhibit further
evidence we do a very simple calculation showing that the dimensional reduction
expected in the gauge theory in this scenario is effective up to an energy
scale that grows with the strength of such a background field. We also show
that independently of the renormalization scheme, the coupling of the double
trace operators in the ultraviolet fixed point increases with the intensity of
the background field. These effects combined can change both, the processes
that are expected to be involved in a collision experiment at a given energy
and the azimuthal anisotropy of the measurements resulting of them.Comment: 23 pages, 10 figures. Added section about renormalization scheme
independenc
Relativistic quantum mechanics of a Dirac oscillator
The Dirac oscillator is an exactly soluble model recently introduced in the
context of many particle models in relativistic quantum mechanics. The model
has been also considered as an interaction term for modelling quark confinement
in quantum chromodynamics. These considerations should be enough for
demonstrating that the Dirac oscillator can be an excellent example in
relativistic quantum mechanics. In this paper we offer a solution to the
problem and discuss some of its properties. We also discuss a physical picture
for the Dirac oscillator's non-standard interaction, showing how it arises on
describing the behaviour of a neutral particle carrying an anomalous magnetic
moment and moving inside an uniformly charged sphere.Comment: 19 pages, 1 figur
The LATERAL ORGAN BOUNDARIES Domain gene family in grapevine: Genome-wide characterization and expression analyses during developmental processes and stress responses
LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) constitute a family of plant-specific transcription factors with key roles in the regulation of plant organ development, pollen development, plant regeneration, pathogen response, and anthocyanin and nitrogen metabolisms. However, the role of LBDs in fruit ripening and in grapevine (Vitis vinifera L.) development and stress responses is poorly documented. By performing a model curation of LBDs in the latest genome annotation 50 genes were identified. Phylogenetic analysis showed that LBD genes can be grouped into two classes mapping on 16 out of the 19 V. vinifera chromosomes. New gene subclasses were identified that have not been characterized in other species. Segmental and tandem duplications contributed significantly to the expansion and evolution of the LBD gene family in grapevine as noticed for other species. The analysis of cis-regulatory elements and transcription factor binding sites in the VviLBD promoter regions suggests the involvement of several hormones in the regulation of LBDs expression. Expression profiling suggest the involvement of LBD transcription factors in grapevine development, berry ripening and stress responses. Altogether this study provides valuable information and robust candidate genes for future functional analysis aiming to clarify mechanisms responsible for the onset of fruit ripening and fruit defense strategies. © 2017 The Author(s)
Enhanced Phenotype Definition for Precision Isolation of Precursor Exhausted Tumor-Infiltrating CD8 T Cells.
In the context of adoptive T cell transfer (ACT) for cancer treatment, it is crucial to generate in vitro large amounts of tumor-specific CD8 T cells with high potential to persist in vivo. PD-1, Tim3, and CD39 have been proposed as markers of tumor-specific tumor-infiltrating CD8 T lymphocytes (CD8 TILs). However, these molecules are highly expressed by terminally differentiated exhausted CD8 T cells (Tex) that lack proliferation potential. Therefore, optimized strategies to isolate tumor-specific TILs with high proliferative potential, such as Tcf1+ precursor exhausted T cells (Tpe) are needed to improve in vivo persistence of ACT. Here we aimed at defining cell surface markers that would unequivocally identify Types for precision cell sorting increasing the purity of tumor-specific PD-1+ Tcf1+ Tpe from total TILs. Transcriptomic analysis of Tpe vs. Tex CD8 TIL subsets from B16 tumors and primary human melanoma tumors revealed that Tpes are enriched in Slamf6 and lack Entpd1 and Havcr2 expression, which encode Slamf6, CD39, and Tim3 cell surface proteins, respectively. Indeed, we observed by flow cytometry that CD39- Tim3- Slamf6+ PD-1+ cells yielded maximum enrichment for tumor specific PD-1+ Tcf1+ OT1 TILs in B16.OVA tumors. Moreover, this population showed higher re-expansion capacity upon an acute infection recall response compared to the CD39+ counterparts or bulk PD-1+ TILs. Hence, we report an enhanced sorting strategy (CD39- Tim3- Slamf6+ PD-1+) of Tpes. In conclusion, we show that optimization of CD8 TIL cell sorting strategy is a viable approach to improve recall capacity and in vivo persistence of transferred cells in the context of ACT
An Immunomodulatory Gallotanin-Rich Fraction From Caesalpinia spinosa Enhances the Therapeutic Effect of Anti-PD-L1 in Melanoma.
PD-1/PD-L1 pathway plays a role in inhibiting immune response. Therapeutic antibodies aimed at blocking the PD-1/PD-L1 interaction have entered clinical development and have been approved for a variety of cancers. However, the clinical benefits are reduced to a group of patients. The research in combined therapies, which allow for a greater response, is strongly encouraging. We previously characterized a polyphenol-rich extract from Caesalpinia spinosa (P2Et) with antitumor activity in both melanoma and breast carcinoma, as well as immunomodulatory activity. We hypothesize that the combined treatment with P2Et and anti-PD-L1 can improve the antitumor response through an additive antitumor effect. We investigated the antitumor and immunomodulatory activity of P2Et and anti-PD-L1 combined therapy in B16-F10 melanoma and 4T1 breast carcinoma. We analyzed tumor growth, hematologic parameters, T cell counts, cytokine expression, and T cell cytotoxicity. In the melanoma model, combined P2Et and anti-PD-L1 therapy has the following effects: decrease in tumor size; increase in the number of activated CD4 <sup>+</sup> and CD8 <sup>+</sup> T cells; decrease in the number of suppressor myeloid cells; increase in PD-L1 expression; decrease in the frequency of CD8 <sup>+</sup> T cell expressing PD-1; improvement in the cytotoxic activity of T cells; and increase in the IFN γ secretion. In the breast cancer model, P2Et and PD-L1 alone or in combination show antitumor effect with no clear additive effect. This study shows that combined therapy of P2Et and anti-PD-L1 can improve antitumor response in a melanoma model by activating the immune response and neutralizing immunosuppressive mechanisms
Excess abdominal fat is associated with cutaneous allodynia in individuals with migraine: a prospective cohort study
Objective: To investigate the specific relationship between cutaneous allodynia (CA) and the percentages of body
fat (BF) and abdominal fat in migraineurs. Additionally, we compared serum levels of inflammatory biomarkers in
patients with and without CA.
Background: Excess abdominal fat might facilitate progressive changes in nociceptive thresholds causing central
sensitization, clinically reflected as CA, which could drive migraine progression.
Methods: This prospective cohort study included 80 patients with migraine (mean age 39 years, 81.2% female) and
39 non-migraine controls. We analysed each participant’s height, body weight, and body mass index (BMI). The
amount and distribution of BF was also assessed by air displacement plethysmography (ADP) and ViScan,
respectively. We analysed serum levels of markers of inflammation, during interictal periods.
Results: We studied 52 patients with episodic migraine (EM) and 28 with chronic migraine (CM). Of the 80 patients,
53 (53.8%) had CA. Migraineurs with CA had a higher proportion of abdominal fat values than patients without CA
(p = 0.04). The independent risk factors for CA were the use of migraine prophylaxis (OR 3.26, 95% CI [1.14 to 9.32];
p = 0.03), proportion of abdominal fat (OR 1.13, 95% CI [1.01 to 1.27]; p = 0.04), and presence of sleep disorders (OR
1.13, 95% CI [00.01 to 1.27]; p = 0.04). The concordance correlation coefficient between the ADP and BMI
measurements was 0.51 (0.3681 to 0.6247). CA was not correlated with the mean plasma levels of inflammatory
biomarkers.
Conclusions: There is a relation between excess abdominal fat and CA. Abdominal obesity might contribute to the
development of central sensitization in migraineurs, leading to migraine chronification
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