4,584 research outputs found
Dynamic Control of a Multistate Chiral Supramolecular Polymer in Water
Natural systems transfer chiral information across multiple length scales through dynamic supramolecular interaction to accomplish various functions. Inspired by nature, many exquisite artificial supramolecular systems have been developed, in which controlling the supramolecular chirality holds the key to completing specific tasks. However, to achieve precise and non-invasive control and modulation of chirality in these systems remains challenging. As a non-invasive stimulus, light can be used to remotely control the chirality with high spatiotemporal precision. In contrast to common molecular switches, a synthetic molecular motor can act as a multistate chiroptical switch with unidirectional rotation, offering major potential to regulate more complex functions. Here, we present a light-driven molecular motor-based supramolecular polymer, in which the intrinsic chirality is transferred to the nanofibers, and the rotation of molecular motors governs the chirality and morphology of the supramolecular polymer. The resulting supramolecular polymer also exhibits light-controlled multistate aggregation-induced emission. These findings present a photochemically tunable multistate dynamic supramolecular system in water and pave the way for developing molecular motor-driven chiroptical materials
Comparative efficacy and acceptability of non-surgical brain stimulation for the acute treatment of major depressive episodes in adults: systematic review and network meta-analysis
OBJECTIVE
To estimate the comparative clinical efficacy and
acceptability of non-surgical brain stimulation for
the acute treatment of major depressive episodes in
adults.
DESIGN
Systematic review with pairwise and network meta-
analysis.
DATA SOURCES
Electronic search of Embase, PubMed/Medline,
and PsycINFO up to 8 May 2018, supplemented by
manual searches of bibliographies of several reviews
(published between 2009 and 2018) and included
trials.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Clinical trials with random allocation to
electroconvulsive therapy (ECT), transcranial magnetic
stimulation (repetitive (rTMS), accelerated, priming,
deep, and synchronised), theta burst stimulation,
magnetic seizure therapy, transcranial direct current
stimulation (tDCS), or sham therapy.
MAIN OUTCOME MEASURES
Primary outcomes were response (efficacy) and all
cause discontinuation (discontinuation of treatment
for any reason) (acceptability), presented as odds
ratios with 95% confidence intervals. Remission and
continuous depression severity scores after treatment
were also examined.
RESULTS
113 trials (262 treatment arms) that randomised
6750 patients (mean age 47.9 years; 59% women)
with major depressive disorder or bipolar depression
met the inclusion criteria. The most studied treatment
comparisons were high frequency left rTMS and tDCS
versus sham therapy, whereas recent treatments
remain understudied. The quality of the evidence was
typically of low or unclear risk of bias (94 out of 113
trials, 83%) and the precision of summary estimates
for treatment effect varied considerably. In network
meta-analysis, 10 out of 18 treatment strategies
were associated with higher response compared
with sham therapy: bitemporal ECT (summary odds
ratio 8.91, 95% confidence interval 2.57 to 30.91),
high dose right unilateral ECT (7.27, 1.90 to 27.78),
priming transcranial magnetic stimulation (6.02, 2.21
to 16.38), magnetic seizure therapy (5.55, 1.06 to
28.99), bilateral rTMS (4.92, 2.93 to 8.25), bilateral
theta burst stimulation (4.44, 1.47 to 13.41), low
frequency right rTMS (3.65, 2.13 to 6.24), intermittent
theta burst stimulation (3.20, 1.45 to 7.08), high
frequency left rTMS (3.17, 2.29 to 4.37), and tDCS
(2.65, 1.55 to 4.55). Network meta-analytic estimates
of active interventions contrasted with another
active treatment indicated that bitemporal ECT and
high dose right unilateral ECT were associated with
increased response. All treatment strategies were at
least as acceptable as sham therapy.
CONCLUSIONS
These findings provide evidence for the consideration
of non-surgical brain stimulation techniques as
alternative or add-on treatments for adults with major
depressive episodes. These findings also highlight
important research priorities in the specialty of brain
stimulation, such as the need for further well designed
randomised controlled trials comparing novel
treatments, and sham controlled trials investigating
magnetic seizure therapy
The multiple solutions of self-consistency condition in Walecka model and the validity of the Brown-Rho scaling law
We investigate the self-consistency condition (SCC) of mean-field theory in
Walecka model and find that the solutions of the SCC are multiple at high
temperature and chemical potential. Using the effective Lagrangian approach, we
study medium effects on the meson mass by taking into account of
vacuum effects. We show that the meson mass decreases with both
temperature and chemical potential with a general tendency, while near the
critical point several meson masses become degenerate due to the
multiple solutions of the SCC. We check the validity of Brown-Rho scaling law
in this case. Finally, we calculate the thermodynamic potential and prove that
the multiple solutions of the SCC result from a first-order phase transition of
nuclear matter in the Walecka model at high temperature and chemical potential.Comment: 10 pages in Revtex with 9 figure
What Does Brain Response to Neutral Faces Tell Us about Major Depression? Evidence from Machine Learning and fMRI
Introduction: A considerable number of previous studies have shown abnormalities in the processing of emotional faces in major depression. Fewer studies, however, have focused specifically on abnormal processing of neutral faces despite evidence that depressed patients are slow and less accurate at recognizing neutral expressions in comparison with healthy controls. The current study aimed to investigate whether this misclassification described behaviourally for neutral faces also occurred when classifying patterns of brain activation to neutral faces for these patients. Methods: Two independent depressed samples: (1) Nineteen medication-free patients with depression and 19 healthy volunteers and (2) Eighteen depressed individuals and 18 age and gender-ratio-matched healthy volunteers viewed emotional faces (sad/neutral; happy/neutral) during an fMRI experiment. We used a new pattern recognition framework: first, we trained the classifier to discriminate between two brain states (e.g. viewing happy faces vs. viewing neutral faces) using data only from healthy controls (HC). Second, we tested the classifier using patterns of brain activation of a patient and a healthy control for the same stimuli. Finally, we tested if the classifier's predictions (predictive probabilities) for emotional and neutral face classification were different for healthy controls and depressed patients. Results: Predictive probabilities to patterns of brain activation to neutral faces in both groups of patients were significantly lower in comparison to the healthy controls. This difference was specific to neutral faces. There were no significant differences in predictive probabilities to patterns of brain activation to sad faces (sample 1) and happy faces (samples 2) between depressed patients and healthy controls. Conclusions: Our results suggest that the pattern of brain activation to neutral faces in depressed patients is not consistent with the pattern observed in healthy controls subject to the same stimuli. This difference in brain activation might underlie the behavioural misinterpretation of the neutral faces content by the depressed patients. © 2013 Oliveira et al
Multi-Target Prediction: A Unifying View on Problems and Methods
Multi-target prediction (MTP) is concerned with the simultaneous prediction
of multiple target variables of diverse type. Due to its enormous application
potential, it has developed into an active and rapidly expanding research field
that combines several subfields of machine learning, including multivariate
regression, multi-label classification, multi-task learning, dyadic prediction,
zero-shot learning, network inference, and matrix completion. In this paper, we
present a unifying view on MTP problems and methods. First, we formally discuss
commonalities and differences between existing MTP problems. To this end, we
introduce a general framework that covers the above subfields as special cases.
As a second contribution, we provide a structured overview of MTP methods. This
is accomplished by identifying a number of key properties, which distinguish
such methods and determine their suitability for different types of problems.
Finally, we also discuss a few challenges for future research
Multiple Group IRT Measurement Invariance Analysis of the Forms of Self-Criticising/Attacking and Self-Reassuring Scale in Thirteen International Samples
The purpose of this study was to examine the measurement invariance of the Forms of Self-Criticising/Attacking & Self-Reassuring Scale (FSCRS) in terms of Item Response Theory differential test functioning in thirteen distinct samples (N = 7714) from twelve different countries. We assessed differential test functioning for the three FSCRS subscales, Inadequate-Self, Hated-Self and Reassured-Self separately. 32 of the 78 pairwise comparisons between samples for Inadequate-Self, 42 of the 78 pairwise comparisons for Reassured-Self and 54 of the 78 pairwise comparisons for Hated-Self demonstrated no differential test functioning, i.e. measurement invariance. Hated-Self was the most invariant of the three subscales, suggesting that self-hatred is similarly perceived across different cultures. Nonetheless, all three subscales of FSCRS are sensitive to cross-cultural differences. Considering the possible cultural and linguistic differences in the expression of self-criticism and self-reassurance, future analyses of the meanings and connotations of these constructs across the world are necessary in order to develop or tailor a scale which allows cross-cultural comparisons of various treatment outcomes related to self-criticism
General boundary conditions for the envelope function in multiband k.p model
We have derived general boundary conditions (BC) for the multiband envelope
functions (which do not contain spurious solutions) in semiconductor
heterostructures with abrupt heterointerfaces. These BC require the
conservation of the probability flux density normal to the interface and
guarantee that the multiband Hamiltonian be self--adjoint. The BC are energy
independent and are characteristic properties of the interface. Calculations
have been performed of the effect of the general BC on the electron energy
levels in a potential well with infinite potential barriers using a coupled two
band model. The connection with other approaches to determining BC for the
envelope function and to the spurious solution problem in the multiband k.p
model are discussed.Comment: 15 pages, 2 figures; to be published in Phys. Rev. B 65, March 15
issue 200
Intracellular chloride concentration influences the GABAA receptor subunit composition
GABAA receptors (GABAARs) exist as different subtype variants showing unique functional properties and defined spatio-temporal expression pattern. The molecular mechanisms underlying the developmental expression of different GABAAR are largely unknown. The intracellular concentration of chloride ([Cl−]i), the main ion permeating through GABAARs, also undergoes considerable changes during maturation, being higher at early neuronal stages with respect to adult neurons. Here we investigate the possibility that [Cl−]i could modulate the sequential expression of specific GABAARs subtypes in primary cerebellar neurons. We show that [Cl−]i regulates the expression of α3-1 and δ-containing GABAA receptors, responsible for phasic and tonic inhibition, respectively. Our findings highlight the role of [Cl−]i in tuning the strength of GABAergic responses by acting as an intracellular messenger
Recommended from our members
Measurements of traffic-dominated pollutant emissions in a Chinese megacity
Direct measurements of NOx, CO and aromatic volatile organic compound (VOC) (benzene, toluene, C2-benzenes and C3-benzenes) flux were made for a central area of Beijing using the eddy-covariance technique. Measurements were made during two intensive field campaigns in central Beijing as part of the Air Pollution and Human Health (APHH) project, the first in November–December 2016 and the second during May–June 2017, to contrast wintertime and summertime emission rates. There was little difference in the magnitude of NOx flux between the two seasons (mean NOx flux was 4.41 mg m−2 h−1 in the winter compared to 3.55 mg m−2 h−1in the summer). CO showed greater seasonal variation, with mean CO flux in the winter campaign (34.7 mg m−2 h−1) being over twice that of the summer campaign (15.2 mg m−2 h−1). Larger emissions of aromatic VOCs in summer were attributed to increased evaporation due to higher temperatures. The largest fluxes in NOx and CO generally occurred during the morning and evening rush hour periods, indicating a major traffic source with high midday emissions of CO, indicating an additional influence from cooking fuel. Measured NOx and CO fluxes were then compared to the MEIC 2013 emissions inventory, which was found to significantly overestimate emissions for this region,providing evidence that proxy-based emissions inventories have positive biases in urban centres. This first set of pollutant fluxes measured in Beijing provides an important benchmark of emissions from the city which can help to inform and evaluate current emissions inventories
A new class of pluripotent stem cell cytotoxic small molecules
10.1371/journal.pone.0085039PLoS ONE93-POLN
- …