697 research outputs found
Duality and Serre functor in homotopy categories
For a (right and left) coherent ring , we show that there exists a duality
between homotopy categories {\mathbb{K}}^{{\rm{b}}}({\rm mod}{\mbox{-}}A^{{\rm
op}}) and {\mathbb{K}}^{{\rm{b}}}({\rm mod}{\mbox{-}}A). If is
an artin algebra of finite global dimension, this duality restricts to a
duality between their subcategories of acyclic complexes,
{\mathbb{K}}^{{\rm{b}}}_{\rm ac}({\rm mod}{\mbox{-}}\Lambda^{\rm op}) and
{\mathbb{K}}^{{\rm{b}}}_{\rm ac}({\rm mod}{\mbox{-}}\Lambda). As a result, it
will be shown that, in this case, {\mathbb{K}}_{\rm ac}^{{\rm{b}}}({\rm
mod}{\mbox{-}}\Lambda) admits a Serre functor and hence has Auslander-Reiten
triangles.Comment: arXiv admin note: text overlap with arXiv:1605.0474
Increased expression of two alternative spliced variants of CD1d molecule in human gastric cancer
Background: CD1d presents glycolipid antigens to invariant natural killer T (iNKT) cells. The role of CD1d in the development of peptic ulcer and gastric cancer has not been revealed, yet. Objective: To clarify the expression of alternatively spliced variants of CD1d in peptic ulcer and gastric cancer. Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC), according to their endoscopic and histopathological examinations. H. pylori infection was diagnosed by rapid urease test and histopathology. The expression levels of V2, V4, and V5 spliced variants of CD1d molecule were determined by quantitative Reverse Transcriptase PCR. Results: Relative gene expression levels of V4 were higher in GC patients (n=37) than those in NUD (n=49) and PUD (n=51) groups (p<0.05 and p<0.01, respectively). Moreover, GC patients showed higher expression levels of V5 compared to NUD and PUD groups (p<0.001 and p<0.001, respectively). Positive correlation coefficients were attained between V4 and V5 expression in patients with PUD (r=0.734, p<0.0001) and GC (r=0.423, p<0.01), but not in patients with NUD. Among NUD patients, the expression levels of V4, but not V5, were higher in H. pylori-positive patients than in H. pylori-negative ones (p<0.01). Conclusion: Collectively, both membrane-bound (V4) and soluble (V5) isoforms of CD1d were over-expressed in gastric tumor tissues, suggesting that they are involved in anti-tumor immune responses. © 2015, Shiraz University of Medical Sciences. All rights reserved
Expression levels of vascular endothelial growth factors A and C in patients with peptic ulcers and gastric cancer
Purpose: Vascular endothelial growth factor (VEGF) is one of the most important growth factors for metastatic tumors. To clarify the role of VEGF-A and C in patients with peptic ulcer disease (PUD) or gastric cancer (GC), we evaluated the expression levels of these two molecules. We also analyzed the effect of Helicobacter pylori infection on VEGF-A and C expression levels
5-year efficacy of all surface laser ablation with cross-linking (ASLA-XTRA) for the treatment of myopia.
The purpose of our study is to examine the long (5-year) efficacy of the all surface laser ablation (ASLA) combined with accelerated cross-linking (CXL) for the treatment of myopia without the use of mitomycin-C (MMC).
This retrospective study consisted of 202 eyes of 118 myopic (SD: 2.41, range: - 1.50 to - 12.75 D) patients (44 males, 74 females). Mean age was 28.50 years (SD: 6.45, range: 18 to 51 years) that underwent ASLA with accelerated CXL for the treatment of their myopia.
The patients underwent routine postoperative assessment on the 1st, 3rd, 7th day and in the 1st, 3rd, 6th and 12th month, 30th month (±6 months), 4th and 5th year. The mean spherical equivalent (SEq) refractive error changed from - 6.41 ± 2.41 D preoperatively to - 0.02 ± 0.53 D at 5 years postoperatively. The haze score was 0.18, 0.25 and 0.28 at 1, 3 and 6 months postoperatively. At 12 months after the treatment, no eyes had significant corneal haze and in all the following postoperative time intervals the haze traces were gone.
ASLA combined with accelerated CXL (ASLA-XTRA) appears to be safe, efficacious and offering very good refractive results. The potential additional benefits of this modality are the stabilizing effect of the refraction and its sterilization effect on the treated cornea without the potential side effects of MMC
Extended vertical trapezius fasciocutaneous flap (back flap) in face and neck burn scar reconstruction
Elevation of the skin along with its deep fascia vascular network is a recent facility for flap design. The longitudinal trapezius fasciocutaneous flap was first introduced in 1996; at that time it did not receive much attention, although it has many significant benefits compared with other available procedures.Sixteen trapezius fasciocutaneous flaps were elevated in 15 patients for reconstruction of severe scarring of the neck and midface. All flaps were based on the deep branch of the transverse cervical artery and included the overlying fascia of the trapezius muscle. Delaying was applied for very long flaps. Two flaps developed minimal distal necrosis (10 cm below the muscle border). The results indicate that an extra-long back fascia flap based on the descending branch of the transverse cervical artery could be formed, which would be long enough to reconstruct the entire neck and safely transfer it to the midface.The vertical trapezius fasciocutaneous flap, with its abundant tissue, excellent blood supply, anatomic proximity, wide arc of rotation, and hidden donor site scar, provides a simple and reliable method for primary reconstruction of various midface and neck defects. Copyright © 2008 by Lippincott Williams & Wilkins
Extended vertical trapezius fasciocutaneous flap (back flap) in face and neck burn scar reconstruction
Elevation of the skin along with its deep fascia vascular network is a recent facility for flap design. The longitudinal trapezius fasciocutaneous flap was first introduced in 1996; at that time it did not receive much attention, although it has many significant benefits compared with other available procedures.Sixteen trapezius fasciocutaneous flaps were elevated in 15 patients for reconstruction of severe scarring of the neck and midface. All flaps were based on the deep branch of the transverse cervical artery and included the overlying fascia of the trapezius muscle. Delaying was applied for very long flaps. Two flaps developed minimal distal necrosis (10 cm below the muscle border). The results indicate that an extra-long back fascia flap based on the descending branch of the transverse cervical artery could be formed, which would be long enough to reconstruct the entire neck and safely transfer it to the midface.The vertical trapezius fasciocutaneous flap, with its abundant tissue, excellent blood supply, anatomic proximity, wide arc of rotation, and hidden donor site scar, provides a simple and reliable method for primary reconstruction of various midface and neck defects. Copyright © 2008 by Lippincott Williams & Wilkins
Gauge fields for ultracold atoms in optical superlattices
We present a scheme that produces a strong U(1)-like gauge field on cold
atoms confined in a two-dimensional square optical lattice. Our proposal relies
on two essential features, a long-lived metastable excited state that exists
for alkaline-earth or Ytterbium atoms, and an optical superlattice. As in the
proposal by Jaksch and Zoller [New Journal of Physics 5, 56 (2003)],
laser-assisted tunneling between adjacent sites creates an effective magnetic
field. In the tight-binding approximation, the atomic motion is described by
the Harper Hamiltonian, with a flux across each lattice plaquette that can
realistically take any value between 0 and . We show how to take advantage
of the superlattice to ensure that each plaquette acquires the same phase, thus
simulating a uniform magnetic field. We discuss the observable consequences of
the artificial gauge field on non-interacting bosonic and fermionic gases. We
also outline how the scheme can be generalized to non-Abelian gauge fields
Regulatory t-cells and their impacts on cytokine profile of end-stage renal disease patients suffering from systemic lupus erythematosus
Autoimmunity is an identified factor for development of end-stage renal disease (ESRD). Regulatory T-cells (Tregs) play a fundamental role in preventing autoimmunity. This study aimed to determine Treg frequency and its effects on cytokine profile of ESRD patients with and without systemic lupus erythematosus (SLE). Moreover, this study also determines how Treg number is affected by blood transfusion and gender. Peripheral blood mononuclear cells were isolated from 26 ESRD and 10 healthy subjects and stained with anti-CD4, anti-CD25, and anti-FoxP3 antibodies. Treg frequencies in ESRD patients with and without blood transfusion were determined by flow cytometry. Antibodies against human leukocyte antigens (HLAs) were investigated by panel-reactive antibodies screening. Tumor growth factor (TGF)-β1, interleukin (IL)-4, IL-10, TNF-α, IL-17A, and interferon (IFN)-γ serum levels in participants were measured by enzyme-linked immunoasorbent assay (ELISA). ESRD patients with SLE, unlike the patients without SLE, showed a significant reduction in Treg percentage compared to healthy subjects (P < 0.01). All women had a reduced number of Tregs compared to men. Treg number was significantly decreased in ESRD patients with HLA antibodies (P < 0.05). Blood transfusion enhanced Treg development in ESRD patients without SLE, unlike the patients with SLE (P < 0.05). ESRD patients with low Treg showed a reduction in TGF-β1 and IL-4 and an increase in TNF-α and IL-17A levels compared to control groups (P < 0.05�0.0001). However, no change was observed in IL-10 and IFN-γ levels. Treg frequency was negatively associated with the age of patients (P < 0.01), while this association was not observed in healthy subjects. Based on these findings, it can be observed that reduction in Treg number may contribute to ESRD development in patients with SLE. © The Author(s) 2019
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