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In this paper, a novel multilayer substrate integrated dual-mode dielectric resonator (DR) filter is proposed. The square dual-mode DR is made of the high permittivity substrate by removing the undesired portions and the surface coppers so that the relatively high unloaded quality factor of the dominate TM11 pair can be obtained which compared to these fully dielectric-filled substrate integrated waveguides. Meanwhile, it can be easily integrated in an equivalent cavity implemented by multilayer printed circuit boards for filter design, showcasing low in-band loss, light weight, and compact size. For demonstration, a multilayer substrate integrated DR bandpass filter centered at X-band is designed and measured. Good agreement between the simulated and measured results can be observed, and the measured insertion loss at the passband center frequency (8.38 GHz) is 1.1 dB.
A band-stop angular filter (BSF) based on hump volume Bragg gratings (HVBGs) is proposed. Band-stop filtering in a two-stage amplifier laser system is discussed and simulated. Simulation results show that small-scale self-focusing effects in the laser system can be effectively suppressed with the BSF due to the control of fast nonlinear growth in a specific range of spatial frequencies in the laser beam. Near-field modulation of the output beam from the laser system was decreased from 2.69 to 1.37 by controlling the fast nonlinear growth of spatial frequencies ranging from
with the BSF. In addition, the BSF can be used in a plug-and-play scheme and has potential applications in high-power laser systems.
This paper presents a novel balanced-to-balanced power divider (PD) based on a simple and compact three-line coupled structure for the first time. By bisecting the proposed symmetrical structure, the differential mode (DM) and the common mode (CM) equivalent circuits can be obtained for analysis. The DM equivalent circuit exhibits a three-line in-phase power dividing response, and then a resistor is added between the two outputs for achieving good isolation. Meanwhile, the CM equivalent circuit shows a three-line all-stop response so that the CM suppression in this design does not need to be considered. Accordingly, the detailed design procedure of the DM PD is given. For demonstration, a prototype centered at 1.95 GHz is designed, fabricated, and measured. The simulated and measured results with good agreement are presented, showing low DM loss and wideband CM suppression.
Previous neuroimaging studies demonstrated that retinal detachment (RD) subjects were associated with abnormal spontaneous brain activities; however, whether the altered interhemispheric functional connectivity (FC) occurred in RD patients remains unknown. The current study tried to explore the alternations of interhemispheric FC of the whole brain in unilateral RD patients using the voxel-mirrored homotopic connectivity (VMHC) method and their connections to clinical features. Methods: We recruited 30 patients with RD (16 males and 14 females) and 30 healthy controls (HCs) (16 males and 14 females) whose age and sex were closely matched. All subjects underwent the rs-fMRI scans. The VMHC method was applied to directly assess the hemispheres’ functional interaction. The VMHC in these brain areas, which could be used as biomarkers to differentiate RD from HC, was identified by the receiver operating characteristic (ROC) curve analyses. The relations between these patients’ clinical features and their mean VMHC signal values in multiple brain regions were calculated by Pearson correlation analysis. Results: RD patients had significantly lower VMHC values than HCs in the bilateral occipital lobe (Brodmann areas, BA 18), bilateral superior temporal gyrus (BA 39), and bilateral cuneus (BA 19). Moreover, the mean VMHC signal values of the bilateral cuneus were in positive correlation with the duration of the RD (r = 0.446, P = 0.013). Conclusion: Our results provided an evidence of disturbed interhemispheric FC in the visual area occurred in RD patients, which might provide some useful information to understand the neural mechanism of RD patients with acute vision loss. Furthermore, the VMHC values might indicate the progress of the RD.
China’s urban population has experienced rapid fertility decline over the past six decades. This drastic change will have a significant impact on China’s demographic, social and economic future. However, the patterns and characteristics of urban China’s fertility decline have not been systematically examined. This study analyses the trends and age patterns of fertility in urban China since the 1950s, and summarizes the major characteristics of reproductive behaviours into four ‘lows’: extremely ‘low’ level of fertility; ‘low’ proportion of two and higher parity births; ‘low’ mean age at birth; and ‘low’ level of childlessness. The paper argues that the highly homogenous reproductive behaviours found in China’s now near 800 million urban population have been in part shaped by the country’s unprecedented government intervention in family planning. The ‘later, longer, fewer’ campaign in the 1970s and the ‘one-child’ policy, in particular, have left clear imprints on China’s reproductive norms and fertility patterns. The government-led family planning programme, however, has not been the only driving force of fertility decline. A wide range of social, economic, political and cultural changes have also affected the transition in family formation, reproductive behaviour and fertility patterns, and this has become increasingly prominent in the past two decades.
A glacier system is regarded as the ensemble of many glaciers sharing the same region, influenced by a similar climate and organized by certain intrinsic laws. It can be either ‘sensitive’ or ‘steady’. On the basis of the structure of the glacier system and the nature of the equilibrium-line altitudes at the steady state, functional models of a glacier system responding to climate warming were established, using the Kotlyakov–Krenke equation relating annual glacier ablation and mean summer temperature and the glacier system’s median size. The modeling results under the climatic scenarios with a rate of temperature increase of 0.01, 0.03 and 0.05 K a-1 indicate that by the end of this century the glacial area of China will be reduced by –14%, –40%and –60% respectively. However, model results show distinct differences between the sensitive glacier system and the steady glacier system.
In the past few years, we have performed a 22 GHz H2O maser survey towards hundreds of BGPS sources using the 25-meter Nanshan Radio Telescope (NSRT) of the Xinjiang Astronomical Observatory, and detected more than one hundred masers. Our aim is to study star formation activities associated with these sources, as well as search for any correlations that may exist between 22 GHz H2O masers and the evolutionary stage of high-mass star formation regions. The NSRT has been upgraded and have now an effective diameter of 26 meter. Besides, cryogenically cooled dual-beam receiver systems covering seven millimeter-wave observing bands have been installed on the NSRT. For the next step of maser observation, we will continue to do H2O and SiO masers survey of massive dust clumps and monitor some maser sources.
Nosocomial outbreaks caused by Salmonella are rare. We describe the investigation and control of a cluster of novel extended-spectrum β-lactamase (ESBL) Salmonella enterica serotype Isangi in a hospital in southeastern Michigan.
An epidemiologic investigation, including case-control study, assessment of infection control practices and environmental cultures, was performed to identify modes of transmission. Healthcare workers (HCWs) exposed to case patients were screened. Strain relatedness was determined using pulsed-field gel electrophoresis (PFGE); ESBL confirmation was conducted using real-time PCR. Control measures were implemented to prevent further transmission.
Between September 2 and October 22, 2015, 19 surgical patients, including 10 organ transplant recipients and 1 HCW, had positive S. Isangi cultures. Of these case patients and HCW, 13 had gastroenteritis, 2 had bacteremia, 1 had surgical-site infection, and 4 were asymptomatic. Pulsed-field gel electrophoresis (PFGE) showed 89.5% similarity among the isolates in these cases. Isolates with resistant-phenotypes possessed plasmid-mediated CTX-M15 ESBL. A total of 19 case patients were compared with 57 control participants. Case patients had significantly higher odds of exposure to an intraoperative transesophageal (TEE) probe (adjusted odds ratio 9.0; 95% confidence interval, 1.12–72.60; P=.02). Possible cross-transmission occurred in the HCW and 2 patients. Cultures of TEE probes and the environment were negative. The outbreak ended after removal of TEE probes, modification of reprocessing procedures, implementation of strict infection control practices, and enhanced environmental cleaning.
We report the first nosocomial ESBL S. Isangi outbreak in the United States. Multiple control measures were necessary to interrupt transmission of this gastrointestinal pathogen. Exposure to possibly contaminated TEE probes was associated with transmission. Periodic monitoring of reprocessing procedures of TEE probes may be required to ensure optimal disinfection.
A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3–5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at 3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.
Optics surface phase defects induced intensity modulation in high-power laser facility for inertial confinement fusion research is studied. Calculations and experiments reveal an exact mapping of the modulation patterns and the optics damage spot distributions from the surface phase defects. Origins are discussed during the processes of optics manufacturing and diagnostics, revealing potential improvements for future optics manufacturing techniques and diagnostic index, which is meaningful for fusion level laser facility construction and its operation safety.
Inspired by the problem of inferring gene networks associated with the host response to infectious diseases, a new framework for discriminative factor models is developed. Bayesian shrinkage priors are employed to impose (near) sparsity on the factor loadings, while non-parametric techniques are utilized to infer the number of factors needed to represent the data. Two discriminative Bayesian loss functions are investigated, i.e. the logistic log-loss and the max-margin hinge loss. Efficient mean-field variational Bayesian inference and Gibbs sampling are implemented. To address large-scale datasets, an online version of variational Bayes is also developed. Experimental results on two real world microarray-based gene expression datasets show that the proposed framework achieves comparatively superior classification performance, with model interpretation delivered via pathway association analysis.
From a statistical-modeling perspective, gene expression analysis can be roughly divided into two phases: exploration and prediction. In the former, the practitioner attempts to get a general understanding of a dataset by modeling its variability in an interpretable way, such that the inferred model can serve as a feature extractor and hypotheses generating mechanism of the underlying biological processes. Factor models are among the most widely employed techniques for exploratory gene expression analysis [1, 2], with principal component analysis a popular special case . Predictive modeling, on the other hand, is concerned with finding a relationship between gene expression and phenotypes, that can be generalized to unseen samples. Examples of predictive models include classification methods like logistic regression and support vector machines [4, 5].
Factor models infer a latent covariance structure among the genes or biomarkers, with data modeled as generated from a noisy low-rank matrix factorization, manifested in terms of a loadings matrix and a factor scores matrix. Different specifications for these matrices give rise to special cases of factor models, such as principal components analysis , nonnegative matrix factorization , independent component analysis , and sparse factor models . Factor models employing a sparse factor loadings matrix are of significant interest in gene-expression analysis, as the nonzero elements in the loadings matrix may be interpreted as correlated gene networks [1, 2, 9].
Most long QT syndrome patients are associated with genetic mutations. We aimed to investigate the clinical and biochemical characteristics and look for genotype-based preventive implications in Chinese long QT syndrome patients.
Methods and results
We identified two missense mutations of the KCNQ1 gene in two independent Chinese families, including a previously reported mutation R380S in the C-terminus and a novel mutation W305L in the P-loop domain of the Kv7.1 channel, respectively. The proband with R380S was an 11-year-old girl who suffered a prolonged corrected QT interval of 660 ms, recurrent syncope, and sudden cardiac death, whose father was an asymptomatic carrier. The mutation W305L was detected in a 36-year-old woman with long QT syndrome and her immediate family members including the proband’s younger sister with an unexplained syncope, her son, and her elder daughter without symptoms. Metoprolol appeared to be effective in preventing arrhythmias and syncope in long QT syndrome patients with mutation W305L. Both R380S and W305L mutations led to “loss-of-function” of the Kv7.1 channel accounting for the clinical phenotypes.
We first show two missense KCNQ1 mutations – R380S and W305L – in Chinese long QT syndrome patients, resulting in the loss of protein function. Mutation W305L in the P-loop domain of the Kv7.1 may derive a pronounced benefit from β-blocker therapy in symptomatic long QT syndrome patients, whereas mutation R380S located in the C-terminus may be associated with a high risk of sudden cardiac death.
How to link genotypes and phenotypes is a long-standing question in modern biology. Modern high-throughput approaches are key technologies at the forefront of genetic research. They enable the analysis of a biological response to thousands of experimental perturbations and require a tight collaboration between experimental and computational scientists. Perturbation studies and computational approaches have revolutionized research in functional genomics and genetics and promise to lay the foundation for personalized medicine. For modern high-throughput technologies, computation is as important as experimentation. Genome-wide image-based RNA interference (RNAi) screens, for example, are only feasible because of computational techniques. Computational skills to analyse the data have become as important as experimental skills to generate the data.
Design and analysis of phenol typing screens depend on the number of genes perturbed and the richness of the phenotype observed (Figure 6.1). At one extreme are high-throughput screens with single reporters, e.g. a genome-wide screen for new components of a pathway. At the other extreme are perturbations of individual genes with very rich phenotypes, e.g. assessing the effects of a single gene perturbation on several molecular levels over time. Between these two extremes lie a variety of possible screen designs. Two widely used scenarios are small-scale perturbations (<20 genes) of a single target pathway with rich readouts, e.g. a global transcriptional profile, and medium-scale perturbations (hundreds of genes) with multi-parametric readouts, e.g. cell morphology or growth in different media. In the following we will discuss statistical and computational methodologies for functional analysis in all four scenarios.
Scenario 1: Genome-wide screens with single reporters
RNAi screens have been frequently and successfully applied for functional profiling of genes on a large scale (Boutros & Ahringer 2008). The vast majority of these applications use a single phenotype (e.g. cell viability, growth rate, activity of reporter constructs) to characterize the function of genes in specific biological pathways.
While a broad line of the Fe Kα emission is commonly found in the X-ray spectra of typical Seyfert galaxies, the situation is unclear in the case of Narrow Line Seyfert 1 galaxies (NLS1s)—an extreme subset which are generally thought to harbor less massive black holes with higher accretion rates. We report results of our study of the assemble property of the Fe K line in NLS1s by stacking the X-ray spectra of a large sample of 51 NLS1s observed with XMM-Newton. We find in the stacked X-ray spectra a prominent, broad emission feature over 4–7 keV, which is characteristic of the broad Fe Kα line. Our results suggest that a relativistic broad Fe line may in fact be common in NLS1s. The line profile is used to study the average spin of the black holes in the sample. We find, for the first time, that their black holes are constrained to be likely spinning at averagely low or moderate rates as a population. The implications of the results are discussed in the context of the black hole growth in NLS1 galaxies.
A study of 7,388 consecutive patients after hepatic resection between 2011 and 2012 identified hepatolithiasis, cirrhosis, and intraoperative blood transfusion as the only independent risk factors of both incisional and organ/space surgical site infection (SSI). Patients with these conditions should be cared for with caution to lower SSI rates.
The present study was conducted to investigate the effects of chitosan (CS)-Zn on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function in weanling pigs. A total of 150 weanling barrows with a body weight of 7·2 kg were randomly allocated into five groups. A basal diet without Zn supplementation was used as the control and other four groups were fed the control diet supplemented with 50 or 100 mg/kg of Zn as CS-Zn, 100 mg/kg of Zn as ZnSO4 and 3000 mg/kg of Zn as ZnO, respectively. The feeding trial lasted for 28 d. The results showed that serum diamine oxidase activities, d-lactate levels and endotoxin contents were lower in pigs fed dietary 100 mg/kg of Zn as CS-Zn or 3000 mg/kg of Zn as ZnO than in pigs fed the control or 100 mg Zn/kg as ZnSO4 diet. The ratios of the villus height:crypt depth of the duodenum, jejunum and ileum were higher in pigs that received 100 mg/kg of Zn as CS-Zn or a high level of Zn as ZnO than in pigs fed the control diet. Moreover, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL)-stained ileal epithelial cells were found in the control group, and apoptotic cells did not appear prominently in pigs that received the 100 mg/kg of CS-Zn or ZnO diet. Secretory IgA concentration in ileal mucus was increased in the dietary group that received 100 mg/kg of CS-Zn or ZnO. These results indicated that dietary 100 mg CS-Zn/kg had similar biological effects to dietary 3000 mg ZnO/kg on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function.
Fine-sized powders of BaSi3Al3O4N5:Eu2+ phosphors with high stability and improved photoluminescence properties were successfully synthesized by the traditional solid-state reaction method under a reductive atmosphere using BaF2-fluxing additives in the raw powder mixture. The produced phosphors had strong blue emission under excitation in ultraviolet (UV) and vacuum ultraviolet (VUV) light, due to the 4f 5d–4f7 transition of Eu2+ ions. X-ray diffraction, scanning electron microscopy, XANES, and the photoluminescence (PL) spectra under UV and VUV were used to characterize the as-received samples. The experimental results showed that the addition of BaF2 flux improved the crystalline regime and the PL properties of the produced phosphors. Most significantly, it allowed control of the particle size and particle size distribution in the final powders but did not jeopardize the high thermal and chemical stability of the phosphors produced. With the modification of the BaF2 flux, the blue-emitting BaSi3Al3O4N5:Eu2+ phosphors will show excellent packing and coating properties and could be a good candidate for the light-emitting diodes and plasma display panels.