7,800 research outputs found
Integrin α2β1 Expression Regulates Matrix Metalloproteinase-1-Dependent Bronchial Epithelial Repair in Pulmonary Tuberculosis.
Pulmonary tuberculosis (TB) is caused by inhalation of Mycobacterium tuberculosis, which damages the bronchial epithelial barrier to establish local infection. Matrix metalloproteinase-1 plays a crucial role in the immunopathology of TB, causing breakdown of type I collagen and cavitation, but this collagenase is also potentially involved in bronchial epithelial repair. We hypothesized that the extracellular matrix (ECM) modulates M. tuberculosis-driven matrix metalloproteinase-1 expression by human bronchial epithelial cells (HBECs), regulating respiratory epithelial cell migration and repair. Medium from monocytes stimulated with M. tuberculosis induced collagenase activity in bronchial epithelial cells, which was reduced by ~87% when cells were cultured on a type I collagen matrix. Matrix metalloproteinase-1 had a focal localization, which is consistent with cell migration, and overall secretion decreased by 32% on type I collagen. There were no associated changes in the specific tissue inhibitors of metalloproteinases. Decreased matrix metalloproteinase-1 secretion was due to ligand-binding to the α2β1 integrin and was dependent on the actin cytoskeleton. In lung biopsies, samples from patients with pulmonary TB, integrin α2β1 is highly expressed on the bronchial epithelium. Areas of lung with disrupted collagen matrix showed an increase in matrix metalloproteinases-1 expression compared with areas where collagen was comparable to control lung. Type I collagen matrix increased respiratory epithelial cell migration in a wound-healing assay, and this too was matrix metalloproteinase-dependent, since it was blocked by the matrix metalloproteinase inhibitor GM6001. In summary, we report a novel mechanism by which α2β1-mediated signals from the ECM modulate matrix metalloproteinase-1 secretion by HBECs, regulating their migration and epithelial repair in TB
Ferromagnetism below 10 K in Mn doped BiTe
Ferromagnetism is observed below 10 K in [Bi0.75Te0.125Mn0.125]Te. This
material has the BiTe structure, which is made from the stacking of two
Te-Bi-Te-Bi-Te blocks and one Bi-Bi block per unit cell. Crystal structure
analysis shows that Mn is localized in the Bi2 blocks, and is accompanied by an
equal amount of TeBi anti-site occupancy in the Bi2Te3 blocks. These TeBi
anti-site defects greatly enhance the Mn solubility. This is demonstrated by
comparison of the [Bi1-xMnx]Te and [Bi1-2xTexMnx]Te series; in the former, the
solubility is limited to x = 0.067, while the latter has xmax = 0.125. The
magnetism in [Bi1-xMnx]Te changes little with x, while that for
[Bi1-2xTexMnx]Te shows a clear variation, leading to ferromagnetism for x >
0.067. Magnetic hysteresis and the anomalous Hall Effect are observed for the
ferromagnetic samples.Comment: Accepted for publication in Phys. Rev.
Comparing the Efficacy of Defusion, Self-as-Context, and Distraction Strategies For Getting Rid of Possessions
Interventions for hoarding disorder need to target difficulty letting go of items to reduce clutter and improve functioning. The present studies were designed to test the efficacy of brief cognitive interventions for letting go of possessions and self-report outcomes. Participants (N = 67 in Study 1; N = 110 in Study 2) received training on defusion or distraction in Study 1 and defusion, self-as-context, or distraction in Study 2 and completed measures at pre- and postintervention. Study 1 found no differences between defusion and distraction on saving, self-rated discomfort with discarding, or perceived importance of the target belonging. In Study 2, participants provided most favorable feedback for self-as-context compared to defusion and distraction, indicating promise of this strategy. Nonetheless, findings from both studies overall provide minimal support for use of present procedures to reduce saving. Limitations include use of non-clinical samples and single-item variables to obtain participant feedback
Empires and Percolation: Stochastic Merging of Adjacent Regions
We introduce a stochastic model in which adjacent planar regions merge
stochastically at some rate , and observe analogies with the
well-studied topics of mean-field coagulation and of bond percolation. Do
infinite regions appear in finite time? We give a simple condition on
for this {\em hegemony} property to hold, and another simple condition for it
to not hold, but there is a large gap between these conditions, which includes
the case . For this case, a non-rigorous analytic
argument and simulations suggest hegemony.Comment: 13 page
Epidermal transient receptor potential vanilloid 1 in idiopathic small nerve fibre disease, diabetic neuropathy and healthy human subjects
10.1111/j.1365-2559.2007.02851.xHistopathology515674-68
Examining the Feasibility and Effectiveness of Online Acceptance and Commitment Therapy Self-Help in a Quasi-Stepped Care Model: A Pilot Study
The global burden of mental illness and limited resources make increasing the efficiency of available mental healthcare resources especially crucial. One way this can be done is a stepped care approach to treatment. To test the viability of using internet-based self-help in a stepped care model, we examined the feasibility, acceptability, and effectiveness of an online self-help acceptance and commitment (ACT) program prior to starting in-person therapy at a university community clinic (N = 51). Online program acceptability was at least moderate. There was clinically significant change in 75.9 to 79.3% and reliable change in 31.0 to 100% of our sample on three of four outcomes of interest (e.g., symptom impairment) after the online program. In addition, 60 to 100% reliably improved from the online program as well as from subsequent treatment on three of four outcomes, indicating that most of our sample progressed through the steps of care effectively and benefited from the quasi-stepped care approach. Scores also indicated positive overall effects of the online program and in-person therapy. Our findings tentatively support the use of low-intensity resources like online self-help programs to reduce therapist burden in outpatient clinics by initiating client progress before intake. Limitation to this approach and the study are discussed
Predictive Modelling Using Unstructured Data From Online Forums: A Case Study on E-cigarette Users
In the age of the digital economy, social media, forums and other online platforms have played active parts in our daily activities. The amount of data digitized and recorded in these platforms have surged exponentially. Many believed that this underexplored unstructured data sources have huge potential in offering insights to policy makers and companies. This paper aims to propose a hybrid approach using inductive and deductive reasoning to identify motivational factors to use e-cigarettes for predictive modelling. A total of 790 comments and discussions relevant to e-cigarette use and motivations to use e-cigarette were scraped and stored from online forums like Reddit, Vapingunderground and e-cigarette-forum. A series of text analytics were conducted on the text corpus and the cluster analysis enabled us to build a predictive model. Using Bayesian Structural Equation Modelling, we concluded that the constructs derived by clustering, i.e. Cost and Convenience and Enjoyment, have significant associations with smokers trying to quit smoking. While health-related issues were inherent to the notion of quitting smoking, enjoyment, cost and convenience were motivational factors which will generate favourable response towards quitting smoking. The findings showed encouraging results from a methodological standpoint and offered insights to policy makers and companies on health-related issues pertaining to the use of e-cigarettes
Memory function approach to the Hall constant in strongly correlated electron systems
The anomalous properties of the Hall constant in the normal state of
high- superconductors are investigated within the single-band Hubbard
model. We argue that the Mori theory is the appropriate formalism to address
the Hall constant, since it aims directly at resistivities rather than
conductivities. More specifically, the frequency dependent Hall constant
decomposes into its infinite frequency limit and a memory function
contribution. As a first step, both terms are calculated perturbatively in
and on an infinite dimensional lattice, where is the correlation strength.
If we allow to be of the order of twice the bare band width, the memory
function contribution causes the Hall constant to change sign as a function of
doping and to decrease as a function of temperature.Comment: 35 pages, RevTex, 3 ps figures include
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