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Imaging of cellular layers in a gut-on-a-chip system has been confined to two-dimensional (2D)-imaging through conventional light microscopy and confocal laser scanning microscopy (CLSM) yielding three-dimensional- and 2D-cross-sectional reconstructions. However, CLSM requires staining and is unsuitable for longitudinal visualization. Here, we compare merits of optical coherence tomography (OCT) with those of CLSM and light microscopy for visualization of intestinal epithelial layers during protection by a probiotic Bifidobacterium breve strain and a simultaneous pathogen challenge by an Escherichia coli strain. OCT cross-sectional images yielded film thicknesses that coincided with end-point thicknesses derived from cross-sectional CLSM images. Light microscopy on histological sections of epithelial layers at the end-point yielded smaller layer thicknesses than OCT and CLSM. Protective effects of B. breve adhering to an epithelial layer against an E. coli challenge included the preservation of layer thickness and membrane surface coverage by epithelial cells. OCT does not require staining or sectioning, making OCT suitable for longitudinal visualization of biological films, but as a drawback, OCT does not allow an epithelial layer to be distinguished from bacterial biofilms adhering to it. Thus, OCT is ideal to longitudinally evaluate epithelial layers under probiotic protection and pathogen challenges, but proper image interpretation requires the application of a second method at the end-point to distinguish bacterial and epithelial films.
Bioinformatic investigations indicate that has-mir-206 (microRNA-206, miRNA-206) could regulate BDNF protein synthesis by interfering with BDNF mRNA translation, which is disrupted in bipolar disorder (BPD).
This study is to investigate whether miRNA-206 gene variants were associated with BPD susceptibility in a Han Chinese population.
342 patients who met DSM-IV criteria for bipolar disorder type I (BPD-I) or type II (BPD-II) and 386 matched health controls were enrolled into this study. the miRNA-206 gene and +/-500bp were selected for gene sequencing. for the case-control genetic comparisons, differences in the genotype and allele distributions between patients and controls were examined using Pearson's χ2 test.
Gene sequencing showed that there are two polymorphisms rs16882131(C/T) and rs62408583 (A/C) located at the upstream of miRNA-206 gene, which are complete linkage disequilibrium. the association analysis showed that there was no significant difference for genotype frequencies (χ2 = 2.075, df = 2, P = 0.354) or for allele frequencies (χ2 = 0.041, df = 1, P = 0.839) between BPD patients and controls. Similarly, no significant difference was found between BPD-I patients and controls (genotype χ2 = 1.411, df = 2, P = 0.494; allele χ2 = 0.380, df = 1, P = 0.538). However, there was significant difference between BPD-II patients and controls (genotype χ2 = 7.933, df = 2, P = 0.019; allele χ2 = 5.403, df = 1, P = 0.020).
Our findings do not support that BPD susceptibility was associated with miRNA-206 gene polymorphisms in the studied Han Chinese population. the association between miRNA-206 gene polymorphisms and bipolar disorder type II is needed to be carefully interpreted. Further studies are necessary to elucidate the involvement miRNA-206 in the pathophysiology of BPD.
To explore the factors associated with occurrence of suicidal risk after treatment of SSRI in bipolar disorder with their first depressive episode.
One hundred and seventy seven bipolar patients were enrolled in this retrospective study. One hundred fifty four patients were included in non-occurrence of suicidal risk group, while twenty three were included in occurrence of suicidal risk group. To compare the demographic and clinic features between these two groups. Stepwise Logistic regression model was used to identify the associated factors. Concordance statistics (i.e. the area under the ROC curve) was used to compute the discrimination of the associated factors, and Hosmer-Lemeshow goodness-of-fit statistic was used to measure the goodness-of-fit.
Clinical features associated with occurrence of suicidal risk after treatment of SSRI in bipolar disorder were as follows: psychotic symptom and symptom of irritability. The odd ratio was 6.23 and 4.04 separately.
This study demonstrated indicated that psychotic symptom and symptom of irritability were associated with occurrence of suicidal risk after treatment of SSRI in bipolar disorder, and it suggested that these two symptoms might be potential to be the predictors of occurrence of suicidal risk after treatment of SSRI in bipolar disorder.
Major depressive disorder (MDD) is associated with abnormal functional connectivity (FC) of amygdala and decreased function of cortico-limibic circuit, which play important roles in the pathogenesis of MDD. However, little is known about the connectivity alterations in late-onset depression (LOD), and whether such disrupted function is correlated with cognitive impairment is unclear.
A total of twenty-three LOD patients and thirty-seven controls underwent neuropsychological tests and resting-state functional magnetic resonance imaging (RS-fMRI). Regional homogeneity (ReHo) and FC of bilateral amygdala seed were used to analyze blood oxygen level-dependent fMRI data between groups.
Compared to controls, LOD groups showed weaker functional activity in bilateral middle frontal gyrus and left medial orbitofrontal gyrus, moreover, the decreased ReHo was positively correlated with Trail making test-B score (TMTB, r= 0.462,P= 0.04). In aspects of FC, left amygdala has reduced FC with right fusiform gyrus, right superior temporal gyrus and right putamen, while right amygdala has reduced FC with left cerebellum. Further correlative analysis found that the decreased FC between amygdala and right putamen was positively correlated with Verbal fluency test-verb score (VFT-verb, r= 0.513,P= 0.021) and the decreased FC between amygdala and superior temporal gyrus was positively correlated with Auditory Verbal Memory Test-delayed recall score (AVLT-delayed recall, r= 0.446,P= 0.049).
Our finding of reduced activation of prefrontal gyrus as well as decreased connection of bilateral amygdala may be key factors of impaired cognitive function in LOD patients and these changes could be early indicator for cognitive deficits.
The present study compared the expression profile and made the classification with the leukocytes by using whole-genome cRNA microarrays among patients with SSD, major depressive disorder (MDD) and healthy controls.
Gene expression profiling was conducted in peripheral blood leucocytes from drug-free first-episode subjects with SSD, MDD, and matched controls (8 subjects in each group) using global mRNA expression arrays. Support vector machines (SVMs) were utilized for training and testing on candidate signature expression profiles from signature selection step.
We identified SSD and MDD gene signatures from blood-based gene expression profile and build a SSD- MDD disorder model with higher predictive power. Firstly, we identified 63 differentially expressed SSD signatures in contrast to control (P <= 5.0E-4) and 30 differentially expressed MDD signatures in contrast to control, respectively. Then, 123 gene signatures were identified with significantly differential expression level between SSD and MDD. Secondly, in order to conduct priority selection for biomarkers for SSD and MDD together, we selected top gene signatures from each group of pair-wise comparison results, and merged the signatures together to generate better profiles used for clearly classify SSD and MDD sets in the same time. In details, we tried different combination of signatures from the three pair-wise compartmental results and finally determined 48 gene expression signatures with 100% accuracy.
Blood cell-derived RNA may have significant value for performing diagnostic functions and identifying disease biomarkers in SSD and MDD. These 48 gene model could classify SSD, MDD, and healthy controls.
To study the relationship between insulin-like growth factor 1 receptor (IGF1R)and subsyndromal symptomatic depression (SSD).
In this case-control study, real-time quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) with TaqMan MGB was used to analyzing the differences of IGF1R gene mRNA expression in peripheral leukocytes between subsyndromal symptomatic depression group(n = 47) and healthy controls(n = 52). At the same time Hamilton Depression Rating Scale -17(HAMD17) were assessed.
IGF1R gene mRNA expression was 0.21 ± 0.11 in SSD group, 0.56 ± 0.37 in healthy group, and there was significant difference between both groups on IGF1R expression(z = 39.54, P < 0.001). the expression levels of IGF1R in SSD patients was not correlated with Hamilton score(r = −0.292, p = 0.275).
This study suggested that the decreased expression of IGF1R were related with the pathophysiology of SSD.
Epigenetic changes may play a role in the etiology of psychotic diseases. It has been demonstrated that olig2 is implicated in schizophrenia (SCZ) and bipolar disorder (BPD). the aim of this study was to investigate the methylation status of a promoter region of the olig2 gene in BPD and SCZ patients.
Our study included 41 BPD and 45 SCZ (DSM-IV criteria) as well as 53 control subjects. DNA was extracted from blood leukocytes and bisulfited sequence analysis was used to determine the DNA methylation status of a typical CpGs island within the promoter region of olig2.
We found the methylated cytosines occurred mainly in two clusters. Olig2 gene promoter was hyper-methylated(∼30%) in DNA derived from the blood leukocytes in SCZ and BD compared to the controls subjects(P = 0.01 and P = 0.03, respectively). There was no statistically significant difference in frequency of site-specific cytosine methylation modification of Olig2 gene between SCZ patients and BD patients(P = 0.21).
We observed increased DNA methylation in the promoter region of the olig2 gene of SCZ and BPD. This could explain the reported decrease of the gene expression. the current study supports the growing interest of DNA methylation in psychopathology.
The potential pattern of regional cerebral blood flow (rCBF) in major depressive disorder (MDD) underlies different response to antidepressants medication remain unclear. This study aimed to investigate the differences of rCBF between patients with different treatment response.
Eighty MDD patients [(44 treatment-responsive depression (RD) and 36 non-responding depression (NRD)] and 42 healthy controls (HC) underwent pulsed arterial spin labeling (PASL) scans in magnetic resonance imaging and clinical estimates. The exact rCBF values of each groups were obtained via quantification evaluation.
Compared to NRD, the RD patients showed decreased rCBF values in frontal sensorimotor network (i.e. left paracentral lobule, left medial frontal gyrus, right superior frontal gyrus and right middle frontal gyrus), and further receiver operating curve (ROC) analyses demonstrated that the altered rCBF in these four regions exhibited outstanding performance on distinguishing NRD from RD. The NRD also exhibited reduced rCBF in bilateral cerebellum posterior lobe and right middle occipital gyrus and elevated rCBF in right postcentral gyrus and right middle frontal gyrus as compared to HC.
The decreased rCBF in frontal sensorimotor network appeared to be distinct characteristics for NRD, and might be severed as promising neuroimaging markers to differentiate depressed patients with weak early response to antidepressant medication. These findings expand our understanding of neural substrate underlying the antidepressant efficacy.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
The intuitive association between cognitive dysfunction in late onset depression (LOD) and the aberrant functional activity in the brain's default-mode network (DMN) has prompted interest in exploring the role of the DMN in LOD. The altered pattern of resting state voxel-mirrored homotopic connectivity (VMHC) in cognitive processes is not yet well understood in LOD.
The study was designed to examine the implicit coupling between the alteration of interhemispheric functional coordination and cognitive impairment in LOD. Thirty-one LOD patients and 37 matched healthy controls (HC) underwent neuropsychological tests and functional magnetic resonance imaging (fMRI) in this study.
Compared to HC group, attenuated VMHC in superior frontal gyrus, superior temporal gyrus, posterior cerebellar lobe, postcentral and precentral gyrus was observed in LOD. Neuro-behavioral relevancy approach revealed that the imbalanced interhemispheric functional coordination in bilateral cerebellum was positively correlated with the performance of trail making test in LOD (r = 0.367, P = 0.040).
Altered linkage pattern of intrinsic homotopic connectivity and cognition was firstly investigated in LOD, and it would provide a novel clue to reveal the neural substrates underlying the cognitive dysfunction in LOD.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Emerging evidences indicate that the alteration of interhemispheric functional coordination may be involved in the pathogenesis of major depressive disorder (MDD). In present study, we aim to explore the potential marker by using the voxel-mirrored homotopic connectivity (VMHC) approach, which may be contributing to predict the clinical prognosis in MDD.
Eighty-two MDD patients and 50 normal control (NC) subjects participated in this study. We divided the MDD group into unremitted and remitted group according to the reduction rate of Hamilton Rating Scale for Depression (HAMD) within 2 weeks.
The study detected significantly decreased VMHC in bilateral precuneus (pCu), inferior temporal gyrus (ITG) and increased VMHC in middle frontal gyrus (MFG) and caudate nucleus when compared remitted depression (RD) group to unremitted depression (URD) group. Meanwhile, when compared with NC group, the URD group presented reduced VMHC in bilateral cerebellum anterior lobe, thalamus and postcentral gyrus. Furthermore, the VHMC in media frontal gyrus, postcentral gyrus and precentral gyrus were significantly decreased in RD group. Correlation analysis suggested that reduced VMHC in bilateral pCu was negatively correlated with the baseline HAMD score of URD (r = −0.325, P = 0.041). Receiver operating characteristic (ROC) curve indicated that three regional VMHC changes could identify depressed patient with poorer treatment response: ITG [area under curve (AUC) = 0.699, P = 0.002, 95% CI = 0.586–0.812], MFG (AUC = 0.692, P = 0.003, 95% CI = 0.580–0.805), pCu (AUC = 0.714, P = 0.001, 95% CI = 0.603–0.825).
The current study combined with previous evidence indicates that the subdued intrinsic interhemispheric functional connectivity might represents a novel neural trait involved in the pathophysiology of MDD.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
The hexagonal boron nitride (h-BN) as a wide bandgap semiconductor is an attractive material for deep ultraviolet (DUV) generation. In this paper we study the prospect of using the stacking hexagonal boron nitride nanosheets (h-BNNS) for generating DUV emission by impact excitation in alternating current driven thin electroluminescence devices (ACTEL) based on BN phosphors having different morphologies. A theoretical approach considered is based on the impact excitation model for generating DUV from stacking h-BNNS under a high electric field. It was found that in the h-BNNS with a thickness of 90 nm biased at 3.33×109 V/m, the quantum yield can reach to 86.8%, and the power conversion efficiency of 1.68%. To achieve the same quantum yield and power conversion efficiency for the ACTEL based on h-BN single crystal, the active phosphor layer should be 2 μm thick when biased at 1.5×108 V/m.
One of the critical components of energy savings in buildings is thermal insulation, especially for windows in cold climates. The conventional approach mainly relies on a double-pane design. In this study, a new concept of “Green Window” has been designed for single-pane applications that lower the U-factor. The “Green Window” is structurally and simply composed of a thin film window coating of chlorophyll that exhibits pronounced photothermal effect, while remaining highly transparent. We demonstrate a new concept in “thermal insulation” via optical means instead of solely through thermal insulators or spectral selectivity. This concept lifts the dependence on insulating materials making single-pane window highly possible.
To explore the prevalence and drivers of hospital-level variability in antibiotic utilization among hematopoietic cell transplant (HCT) recipients to inform antimicrobial stewardship initiatives.
Retrospective cohort study using data merged from the Pediatric Health Information System and the Center for International Blood and Marrow Transplant Research.
The study included 27 transplant centers in freestanding children’s hospitals.
The primary outcome was days of broad-spectrum antibiotic use in the interval from day of HCT through neutrophil engraftment. Hospital antibiotic utilization rates were reported as days of therapy (DOTs) per 1,000 neutropenic days. Negative binomial regression was used to estimate hospital utilization rates, adjusting for patient covariates including demographics, transplant characteristics, and severity of illness. To better quantify the magnitude of hospital variation and to explore hospital-level drivers in addition to patient-level drivers of variation, mixed-effects negative binomial models were also constructed.
Adjusted hospital rates of antipseudomonal antibiotic use varied from 436 to 1121 DOTs per 1,000 neutropenic days, and rates of broad-spectrum, gram-positive antibiotic use varied from 153 to 728 DOTs per 1,000 neutropenic days. We detected variability by hospital in choice of antipseudomonal agent (ie, cephalosporins, penicillins, and carbapenems), but gram-positive coverage was primarily driven by vancomycin use. Considerable center-level variability remained even after controlling for additional hospital-level factors. Antibiotic use was not strongly associated with days of significant illness or mortality.
Among a homogenous population of children undergoing HCT for acute leukemia, both the quantity and spectrum of antibiotic exposure in the immediate posttransplant period varied widely. Antimicrobial stewardship initiatives can apply these data to optimize the use of antibiotics in transplant patients.
Muons produced by the Bethe–Heitler process from laser wakefield accelerated electrons interacting with high
materials have velocities close to the laser wakefield. It is possible to accelerate those muons with laser wakefield directly. Therefore for the first time we propose an all-optical ‘Generator and Booster’ scheme to accelerate the produced muons by another laser wakefield to supply a prompt, compact, low cost and controllable muon source in laser laboratories. The trapping and acceleration of muons are analyzed by one-dimensional analytic model and verified by two-dimensional particle-in-cell (PIC) simulation. It is shown that muons can be trapped in a broad energy range and accelerated to higher energy than that of electrons for longer dephasing length. We further extrapolate the dependence of the maximum acceleration energy of muons with the laser wakefield relativistic factor
and the relevant initial energy
. It is shown that a maximum energy up to 15.2 GeV is promising with
on the existing short pulse laser facilities.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
The SkyMapper Transient survey (SMT) is exploring variability in the southern sky by performing (a) a rolling search to discover and study supernovæ, and (b) a Target of Opportunity programme that uses the robotic SkyMapper Telescope at Siding Spring Observatory. The supernova survey is obtaining a non-targeted sample of Type Ia supernovæ (SNe Ia) at low redshifts, z < 0.1, and studying other interesting transients found with the search strategy. We have a Target of Opportunity programme with an automatic response mechanism to search for optical counterparts to gravitational-wave and fast radio-burst events; it benefits from SkyMapper’s large field of view of 5.7 sq. deg. and a rapid data reduction pipeline.
We present first results of the SMT survey. The SMT pipeline can process and obtain potential candidates within 12 hours of observation. It disentangles real transients from processing artefacts using a machine-learning algorithm. To date, SMT has discovered over 60 spectroscopically confirmed supernovæ, several peculiar objects, and over 40 SNe Ia including one (SNIa 2016hhd) which was found within the first few days of explosion. We have also participated in searches for optical counterparts of gravitational waves, fast radio bursts and other transients, and have published observations of the optical counterpart of the gravitational-wave event GW170817. We also participate in coordinated observations with the Deeper Wider Faster programme, and the Kepler K2 cosmology project.
With so many spectroscopic surveys, both past and upcoming, such as SDSS and LAMOST, the number of accessible stellar spectra is continuously increasing. There is therefore a great need for automated procedures that will derive estimates of stellar parameters. Working with spectra from SDSS and LAMOST, we put forward a hybrid approach of Kernel Principal Component Analysis (KPCA) and Support Vector Machine (SVM) to determine the stellar atmospheric parameters effective temperature, surface gravity and metallicity. For stars with both APOGEE and LAMOST spectra, we adopt the LAMOST spectra and APOGEE parameters, and then use KPCA to reduce dimensionality and SVM to measure parameters. Our method provides reliable and precise results; for example, the standard deviation of effective temperature, surface gravity and metallicity for the test sample come to approximately 47–75 K, 0.11–0.15 dex and 0.06–0.075 dex, respectively. The impact of the signal:noise ratio of the observations upon the accuracy of the results is also investigated.
Using the spectroscopic distances of over 0.12 million A-type stars selected from the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC), we map their three-dimensional number density distributions in the Galaxy. These stellar number density maps allow an investigation of the Galactic young age thin disk structure with no a priori assumptions about the functional form of its components. The data show strong evidence for a significant flaring young disk. A more detail analysis show that the stellar flaring have different behaviours between the Northern and the Southern Galactic disks. The maps also reveal spatially coherent, kpc-scale stellar substructure in the thin disk. Finally, we detect the Perseus arm stellar overdensity at R ~ 10 kpc.
Using the data from the LAMOST Galactic spectroscopic surveys and some other surveys, we have started a series of work to measure the mass distribution of our Galaxy. As a result of the first-stage, we have constructed the Galactic rotation curve out to 100 kpc and the Galactic escape velocity curve between 5 and 14 kpc. From the two curves, we have built parametrized mass models for our Galaxy, respectively. Both models yield a similar result for the Milky Way's virial mass: ~ 0.9 × 1012 M⊙.
In a previous study we investigated three-scalar mixing in a turbulent coaxial jet (Cai et al.J. Fluid Mech., vol. 685, 2011, pp. 495–531). In this flow a centre jet and a co-flow are separated by an annular flow; therefore, the resulting mixing process approximates that in a turbulent non-premixed flame. In the present study, we investigate the effects of the velocity and length scale ratios of the annular flow to the centre jet, which determine the relative mean shear rates between the streams and the degree of separation between the centre jet and the co-flow, respectively. Simultaneous planar laser-induced fluorescence and Rayleigh scattering are employed to obtain the mass fractions of the centre jet scalar (acetone-doped air) and the annular flow scalar (ethylene). The results show that varying the velocity ratio and the annulus width modifies the scalar fields through mean-flow advection, turbulent transport and small-scale mixing. While the evolution of the mean scalar profiles is dominated by the mean-flow advection, the shape of the joint probability density function (JPDF) was found to be largely determined by the turbulent transport and molecular diffusion. Increasing the velocity ratio results in stronger turbulent transport, making the initial scalar evolution faster. However, further downstream the evolution is delayed due to slower small-scale mixing. The JPDF for the higher velocity ratio cases is bimodal at some locations while it is always unimodal for the lower velocity ratio cases. Increasing the annulus width delays the progression of mixing, and makes the effects of the velocity ratio more pronounced. For all cases the diffusion velocity streamlines in the scalar space representing the effects of molecular diffusion generally converge quickly to a curved manifold, whose curvature is reduced as mixing progresses. The curvature of the manifold increases significantly with the velocity and length scale ratios. Predicting the observed mixing path along the manifold as well as its dependence on the velocity and length scale ratios presents a challenge for mixing models. The results in the present study have implications for understanding and modelling multiscalar mixing in turbulent reactive flows.