The fundamental energy gap of a periodic solid distinguishes insulators from metals and characterizes low-energy single-electron excitations. However, the gap in the band structure of the exact ...multiplicative Kohn–Sham (KS) potential substantially underestimates the fundamental gap, a major limitation of KS densityfunctional theory. Here, we give a simple proof of a theorem: In generalized KS theory (GKS), the band gap of an extended system equals the fundamental gap for the approximate functional if the GKS potential operator is continuous and the density change is delocalized when an electron or hole is added. Our theorem explains how GKS band gaps from metageneralized gradient approximations (meta-GGAs) and hybrid functionals can be more realistic than those from GGAs or even from the exact KS potential. The theorem also follows from earlier work. The band edges in the GKS one-electron spectrum are also related to measurable energies. A linear chain of hydrogen molecules, solid aluminum arsenide, and solid argon provide numerical illustrations.
Radiomics involves the study of tumor images to identify quantitative markers explaining cancer heterogeneity. The predominant approach is to extract hundreds to thousands of image features, ...including histogram features comprised of summaries of the marginal distribution of pixel intensities, which leads to multiple testing problems and can miss out on insights not contained in the selected features. In this paper, we present methods to model the entire marginal distribution of pixel intensities via the quantile function as functional data, regressed on a set of demographic, clinical, and genetic predictors to investigate their effects of imaging-based cancer heterogeneity. We call this approach quantile functional regression, regressing subject-specific marginal distributions across repeated measurements on a set of covariates, allowing us to assess which covariates are associated with the distribution in a global sense, as well as to identify distributional features characterizing these differences, including mean, variance, skewness, heavy-tailedness, and various upper and lower quantiles. To account for smoothness in the quantile functions, account for intrafunctional correlation, and gain statistical power, we introduce custom basis functions we call quantlets that are sparse, regularized, near-lossless, and empirically defined, adapting to the features of a given dataset and containing a Gaussian subspace so non-Gaussianness can be assessed. We fit this model using a Bayesian framework that uses nonlinear shrinkage of quantlet coefficients to regularize the functional regression coefficients and provides fully Bayesian inference after fitting a Markov chain Monte Carlo. We demonstrate the benefit of the basis space modeling through simulation studies, and apply the method to Magnetic resonance imaging (MRI)-based radiomic dataset from Glioblastoma Multiforme to relate imaging-based quantile functions to various demographic, clinical, and genetic predictors, finding specific differences in tumor pixel intensity distribution between males and females and between tumors with and without DDIT3 mutations.
Supplementary materials
for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement.
We present quasielastic neutron scattering results on hydrous silica, sodium aluminosilicate, and sodium trisilicate melts with 10 mol% total water content, studied at high temperature under high ...pressure. Combining neutron time-of-flight spectrometry with neutron backscattering, intrinsic, microscopic proton dynamics is investigated on a time scale from 0.2 ps up to 1 ns between 850 K and 1250 K. All three hydrous silicate melts exhibit a relatively slow proton dynamics, although the melt viscosity is drastically reduced upon water dissolution. The self-diffusion coefficient of proton in the hydrous sodium trisilicate melt is on the order of 10−11 m2s−1, two orders of magnitude slower than the sodium dynamics in the corresponding anhydrous melt. The proton dynamics in hydrous silica and albite is not faster than that time scale. We show that the transport mechanism involves not only –OH but also molecular water species. All protons are mobile during the transport of the water instead of diffusion of a specific water speciation. These characteristics of the proton structural relaxation in the melt can be attributed to a transport in a complex H-bonding environment.
Aliment Pharmacol Ther 31, 486–492
Summary
Background Infliximab was approved for use in ulcerative colitis in recent years. It has been debated if infliximab increases the risk of post‐operative ...complications in patients with ulcerative colitis.
Aim To perform a meta‐analysis that examines the relationship between preoperative infliximab treatment and short‐term post‐operative complications in patients with ulcerative colitis.
Methods We searched the PubMed and MEDLINE databases to identify observational studies on the impact of pre‐operative infliximab use on short‐term post‐operative complications in ulcerative colitis. Infectious complications mainly included wound infection, sepsis and abscess, whereas non‐infectious complications included intestinal obstruction, thromboembolism and gastrointestinal haemorrhage. Pooled odds ratios (ORs) were calculated for each relationship.
Results A total of 5 studies and 706 patients were included in our meta‐analysis. Overall, we did not find a strong association between pre‐operative treatment of infliximab and short‐term infectious OR 2.24, 95% confidence interval (CI) 0.63–7.95 or non‐infectious (OR 0.85, 95% CI 0.50–1.45) post‐operative complications in ulcerative colitis patients. On the contrary, we discovered that pre‐operative infliximab use increased short‐term total post‐operative complications (OR 1.80, 95% CI 1.12–2.87).
Conclusions Pre‐operative infliximab use increased the risk of short‐term post‐operative complications. Subgroup analysis is underpowered to assess the nature of these complications but shows a trend towards increased post‐operative infection.
Recent findings have raised new interests about the use of anticholinergics, especially tiotropium, for the treatment of asthma. This study was performed to determine whether an additional ...improvement in lung function is obtained when tiotropium is administrated in addition to conventional therapies in severe asthmatics, and to identify factors capable of predicting the response to tiotropium, using a pharmacogenetic approach. A total of 138 severe asthmatics on conventional medications and with decreased lung function were randomly recruited. Tiotropium 18 μg was added once a day and lung functions were measured every 4 weeks. Responders were defined as those with an improvement of greater-than-or-equal15% (or 200 ml) in the forced expiratory volume in 1 s (FEV1) that was maintained for at least 8 successive weeks. Eleven single nucleotide polymorphisms (SNPs) in CHRM1-3 (coding muscarinic receptors one to three) which were identified by re-sequencing, and Arg16Gly and Gln27Glu in ADRB2 (coding β₂ adrenoreceptor) were scored in 80 of the 138 asthmatics. Forty-six of the 138 asthmatics (33.3%) responded to tiotropium treatment. Logistic regression analyses (controlled for age, gender, and smoking status) showed that Arg16Gly in ADRB2 P = 0.003, OR (95% CI) = 0.21 (0.07-0.59) in a minor allele-dominant model was significantly associated with response to tiotropium. As many as 30% of severe asthmatics on conventional medications with reduced lung function were found to respond to adjuvant tiotropium. The presence of Arg16Gly in ADRB2 may predict response to tiotropium.
The NuTeV Collaboration has extracted the electroweak parameter sin(2)theta(W) from the measurement of the ratios of neutral current to charged current nu and (-)nu cross sections. Our value, ...sin(2)theta((on-shell))(W) = 0.2277 +/- 0.0013(stat) +/- 0.0009(syst), is 3 standard deviations above the standard model prediction. We also present a model independent analysis of the same data in terms of neutral-current quark couplings.
Globalization of clinical research has led to an increase in clinical trials conducted outside of the United States that are submitted to the US Food and Drug Administration (FDA) in new drug ...applications. This article discusses the FDA's experience with these submissions in specific therapeutic areas, including the extent of this practice, differences between the effectiveness and safety outcomes of studies conducted inside and outside the United States, and the FDA's approach to acceptance of these trials.
Clinical Pharmacology & Therapeutics (2013); 94 2, 230–242. doi:10.1038/clpt.2013.70
PDF
