Microbiome of limb-threatening diabetic foot ulcers indicates the association of fastidious Stenotrophomonas and major amputation.

BACKGROUND: Proper identification of the polymicrobial microorganisms in patients with limb-threatening diabetic foot ulcers (LTDFUs) using conventional culture is insufficient. This prospective study evaluates the potential value of adjuvant molecular testing assisting in identify fastidious micro-organisms in LTDFUs compared to standard treatment alone. METHODS: Ninety patients with LTDFUs received interdisciplinary and standard antibiotic treatment in a referral diabetic foot center. A simultaneous 16S amplicon sequencing (16S AS) specimen along with conventional culture collected at admission was used to retrospectively evaluate the microbiological findings and its association with amputation outcomes. RESULTS: The microorganism count revealed by 16S AS overwhelmed that of conventional culturing (17 vs. 3 bacteria/ulcer respectively). The Stenotrophomonas spp. revealed in 29 patients were highly correlated with major (above ankle) amputation (OR: 4.76, 95% CI 1.01-22.56), while only one had been concomitantly identified by conventional culturing. Thus, there were 27 cases without proper antibiotics coverage during treatment. CONCLUSIONS: Adjuvant molecular testing assisted identification of fastidious pathogens such as Stenotrophomonas infection and might be associated with major amputation in patients with LTDFUs.

A Curvilinear-Path Umbrella Sampling Approach to Characterizing the Interactions Between Rapamycin and Three FKBP12 Variants.

Rapamycin is an immunosuppressant macrolide that exhibits anti-proliferative properties through inhibiting the mTOR kinase. In fact, the drug first associates with the FKBP12 enzyme before interacting with the FRB domain of its target. Despite the availability of structural and thermodynamic information on the interaction of FKBP12 with rapamycin, the energetic and mechanistic understanding of this process is still incomplete. We recently reported a multiple-walker umbrella sampling simulation approach to characterizing the protein-protein interaction energetics along curvilinear paths. In the present paper, we extend our investigations to a protein-small molecule duo, the FKBP12•rapamycin complex. We estimate the binding free energies of rapamycin with wild-type FKBP12 and two mutants in which a hydrogen bond has been removed, D37V and Y82F. Furthermore, the underlying mechanistic details are analyzed. The calculated standard free energies of binding agree well with the experimental data, and the roles of the hydrogen bonds are shown to be quite different for each of these two mutated residues. On one hand, removing the carboxylate group of D37 strongly destabilizes the association; on the other hand, the hydroxyl group of Y82 is nearly unnecessary for the stability of the complex because some nonconventional, cryptic, indirect interaction mechanisms seem to be at work.

Robust formation of amorphous Sb2S3 on functionalized graphene for high-performance optoelectronic devices in the cyan-gap.

Despite significant progress in the fabrication and application of semiconductor materials for optical emitters and sensors, few materials can cover the cyan-gap between 450 and 500 nm. We here introduce a robust and facile method to deposit amorphous Sb2S3 films with a bandgap of 2.8 eV. By exploiting the tunable functionality of graphene, a two-dimensional material, efficient deposition from a chemical was achieved. Ozone-generated defects in the graphene were shown to be required to enhance the morphology and quality of the material and comprehensive characterization of the seed layer and the Sb2S3 film were applied to design an optimal deposition process. The resulting material exhibits efficient carrier transport and high photodetector performance as evidenced by unprecedented responsivity and detectivity in semiconductor/graphene/glass vertical heterostructures. (112 A/W, 2.01 × 1012 Jones, respectively).

Concurrent electrophysiological and hemodynamic measurements of evoked neural oscillations in human visual cortex using sparsely interleaved fast fMRI and EEG.

Electroencephalography (EEG) concurrently collected with functional magnetic resonance imaging (fMRI) is heavily distorted by the repetitive gradient coil switching during the fMRI acquisition. The performance of the typical template-based gradient artifact suppression method can be suboptimal because the artifact changes over time. Gradient artifact residuals also impede the subsequent suppression of ballistocardiography artifacts. Here we propose recording continuous EEG with temporally sparse fast fMRI (fast fMRI-EEG) to minimize the EEG artifacts caused by MRI gradient coil switching without significantly compromising the field-of-view and spatiotemporal resolution of fMRI. Using simultaneous multi-slice inverse imaging to achieve whole-brain fMRI with isotropic 5-mm resolution in 0.1 â€‹s, and performing these acquisitions once every 2 â€‹s, we have 95% of the duty cycle available to record EEG with substantially less gradient artifact. We found that the standard deviation of EEG signals over the entire acquisition period in fast fMRI-EEG was reduced to 54% of that in conventional concurrent echo-planar imaging (EPI) and EEG recordings (EPI-EEG) across participants. When measuring 15-Hz steady-state visual evoked potentials (SSVEPs), the baseline-normalized oscillatory neural response in fast fMRI-EEG was 2.5-fold of that in EPI-EEG. The functional MRI responses associated with the SSVEP delineated by EPI and fast fMRI were similar in the spatial distribution, the elicited waveform, and detection power. Sparsely interleaved fast fMRI-EEG provides high-quality EEG without substantially compromising the quality of fMRI in evoked response measurements, and has the potential utility for applications where the onset of the target stimulus cannot be precisely determined, such as epilepsy.

Modulation of cell morphogenesis by tousled-like kinase in the Drosophila follicle cell.

BACKGROUND: Tousled-like kinase (Tlk) is a conserved serine/threonine kinase regulating DNA replication, chromatin assembly, and DNA repair. Previous studies have suggested that Tlk is involved in cell morphogenesis in vitro. In addition, tlk genetically interact with Rho1, which encodes a key regulator of the cytoskeleton. However, whether Tlk plays a physiological role in cell morphogenesis and cytoskeleton rearrangement remains unknown. RESULTS: In tlk mutant follicle cells, area of the apical domain was reduced. The density of microtubules was increased in tlk mutant cells. The density of actin filaments was increased in the apical region and decreased in the basal region. Because area of the apical domain was reduced, we examined the levels of proteins located in the apical region by using immunofluorescence. The fluorescence intensities of two adherens junction proteins Armadillo (Arm) and DE-cadherin (DE-cad), atypical protein kinase C (aPKC), and Notch, were all increased in tlk mutant cells. The basolateral localized Discs large (Dlg) shifted apically in tlk mutant cells. CONCLUSIONS: Increase of protein densities in the apical region might be resulted from disruption of the cytoskeleton and shrinkage of the apical domain. Together, these data suggest a novel role of Tlk in maintaining cell morphology, possibly through modulating the cytoskeleton.

Characteristics of Klebsiella pneumoniae bacteremia in community-acquired and nosocomial infections in diabetic patients.

BACKGROUND: Although diabetes mellitus is known as a major risk factor for Klebsiella pneumoniae infection, the differences in clinical characteristics between community-acquired and nosocomial K. pneumoniae bacteremia in diabetic patients have been rarely reported. METHODS: This retrospective analysis enrolled 193 adult diabetic patients with K. pneumoniae bacteremia hospitalized between January 2005 and December 2006. The chi-squared test, analysis of variance (ANOVA), Student's t test, Fisher exact test, and Cox regression model were used for statistical analysis. RESULTS: Of the enrolled patients, 147 had community-acquired infections and 46 had nosocomial infections. Compared with the community group, the nosocomial group had higher rates of in-hospital mortality (41.3% vs. 18.4%, p=0.001), malignancy (50.0% vs. 19.0%, p<0.001), and leukopenia (21.7% vs. 5.4%, p=0.001) but had lower levels of serum C-reactive protein (124.3 mg/L vs. 188.7 mg/L, p=0.018) and HbA1c (8.1% vs. 9.5%, p=0.025). The rate of infection with the extended-spectrum ß-lactamase-producing strain (ESBL infection) in the nosocomial group was 11 times higher than that in the community group (45.7% vs. 4.1%, p<0.001). ESBL infection accounted for 53% of mortality in the nosocomial group. Pneumonia was more common in the nosocomial group, while local abscess was more common in the community group. The risk factors for mortality were pneumonia, leukopenia, cirrhosis, and a high serum creatinine ratio (creatinine level at admission/baseline). CONCLUSIONS: The nosocomial group had more ESBL infections which might account for the higher mortality. The HbA1c level during the course of infection did not affect the outcome. Pneumonia, leukopenia, cirrhosis, and a high serum creatinine ratio at admission were the risk factors for poor outcome.