Lead halide perovskite nanowires (NWs) have been demonstrated in pulsed lasing with high quantum yields, low thresholds, and broad tunability. However, continuous‐wave (CW) lasing, necessary for many ...optoelectronic applications, has not been achieved to date. This is thought to be due to many‐body screening, which reduces the excitonic resonance enhancement of the oscillator strength at high excitation densities necessary for population inversion. Here CW lasing in CsPbBr3 perovskite NWs is reported. Analysis of the cavity modes and their temperature dependence reveals that both CW and pulsed lasing originate from polariton modes near the bottleneck region on the lower polariton branch, with a vacuum Rabi splitting of 0.20 ± 0.03 eV. These findings suggest that lead halide perovskite NWs may serve as low‐power CW coherent light sources and as model systems for polaritonics in the strong‐coupling regime.
Optically pumped, continuous‐wave lasing in a CsPbBr3 nanowire is enabled by strong confinement‐enhanced light–matter coupling. Nanowire waveguide‐cavity photons are strongly coupled to the CsPbBr3 exciton resonance to give suboptical bandgap exciton–polariton states that undergo stimulated emission. The Rabi splitting is quantified by modeling the light leaking out at the end facets. This interaction leads to low‐threshold lasing and high effective Q‐factors.
Summary
Background
Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time.
Objectives
This study aimed to clarify the ...current epidemiological characteristics and pathogen spectrum of tinea capitis in China.
Methods
A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. When necessary, the pathogens were further identified by morphology or molecular sequencing in the central laboratory.
Results
Among all enrolled patients, 74·1% of the cases were in patients aged 2–8 years. The children with tinea capitis were mainly boys (56·2%) and were more likely than adults to have a history of animal contact (57·4% vs. 35·3%, P = 0·012) and zoophilic dermatophyte infection (73·5% vs. 47%). The adults were mainly female (83%) and were more likely than children to have anthropophilic agent infection (53% vs. 23·9%). The most common pathogen was zoophilic Microsporum canis (354, 65·2%), followed by anthropophilic Trichophyton violaceum (74, 13·6%). In contrast to the eastern, western and northeastern regions, where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69%, P < 0·001), where the patients had the most tinea at other sites (20%) and dermatophytosis contact (26%) but the least animal contact (39%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang province.
Conclusions
Boys aged approximately 5 years were the most commonly affected group. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.
What is already known about this topic?
Tinea capitis is an infection of the scalp and hair caused by dermatophytes and is still common in developing countries. Prepubertal children are mainly affected.
The pathogen spectrum of tinea capitis varies across different geographical areas and changes over time.
Nationwide prospective epidemiological surveys of tinea capitis in China are rare and out of date.
What does this study add?
This study provides data concerning the epidemiological characteristics and pathogen spectrum of tinea capitis in contemporary China.
Boys aged approximately 5 years were most commonly affected and were more likely than adults to have zoophilic dermatophyte infection.
The main pathogens of tinea capitis in China are zoophilic dermatophytes, mainly Microsporum canis. In contrast to the other regions, the predominant pathogens in central China are anthropophilic dermatophytes.
Plain language summary available online
We analyzed the terrigenous fraction of a sediment core from the northern slope of the South China Sea, to better understand the depositional history of the region since the Last Glacial Maximum ...(LGM). Temporal variations in the grain size and clay mineral composition revealed a complex set of overlapping controls. Approximately 90% of terrigenous sediment throughout the core ranged in size from 5.5 to 8.5 Φ, with the 5.25–6.25 Φ size class being particularly sensitive to environmental changes. The proportion of this fraction decreased during deglacial, indicating a reduction in the supply of coarser grains due to coastline retreat. As the sea level rose toward its present position, the relative proportion of clay derived from Taiwan increased; however, the mass accumulation rate of Taiwan-derived clay decreased, suggesting a reduction in the westward bottom current intensity. In contrast, the relative contribution of clay from the Pearl River decreased from ~40% during the LGM, to ~5% when the sea level reached ~70m below its present position. The Pearl River contribution has remained consistently low throughout the Holocene, indicating that shore-parallel circulation patterns on the shelf resembled their present configuration by 13ka. Compared to Taiwan and the Pearl River, the proportion of clay derived from the area east of Pearl River (EPR) was relatively minor, and less variable. A local peak in the relative contribution from this area occurred during a Melt Water Pulse Event (MWP-1A), suggesting that a reservoir of smectite-rich clays residing in coastal bays was remobilized by this marine transgression. Spectral analysis of the relative contributions of the three major clay sources revealed a significant periodicity of ~380years, which may reflect changes in solar insolation modulating the flux of clay minerals from Taiwan and the Pearl River to the deposition site on a centennial scale.
•Taiwan sediment contribution reached the peak (>80%) in the Holocene.•The Pearl River sediment contribution was the highest (<30%) during the LGM.•The KC might be significant force for Taiwanese sediment transport.•Sediment sources remained stable as sea level rose to a certain height.
Abstract
We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionization (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperature ...fluctuation power spectrum from the EoR. The KDE estimates the underlying probability distribution function of fluctuations as a function of spatial scale, and contains different systematic biases and errors to the typical approach to estimating the fluctuation power spectrum. Extraction of histograms of visibilities allows moments analysis to be used to discriminate foregrounds from 21 cm signal and thermal noise. We use the information available in the histograms, along with the statistical dis-similarity of foregrounds from two independent observing fields, to robustly separate foregrounds from cosmological signal, while making no assumptions about the Gaussianity of the signal. Using two independent observing fields to robustly discriminate signal from foregrounds is crucial for the analysis presented in this paper. We apply the techniques to 13 h of Murchison Widefield Array EoR data over two observing fields. We compare the output to that obtained with a comparative power spectrum estimation method, and demonstrate the reduced foreground contamination using this approach. Using the second moment obtained directly from the KDE distribution functions yields a factor of 2–3 improvement in power for k < 0.3 h Mpc−1 compared with a matched delay space power estimator, while weighting data by additional statistics does not offer significant improvement beyond that available for thermal noise-only weights.
Shikonin and its derivatives are important medicinal secondary metabolites accumulating in roots of Lithospermum erythrorhizon. Although some membrane proteins have been identified as transporters of ...secondary metabolites, the mechanisms underlying shikonin transport and accumulation in L. erythrorhizon cells still remain largely unknown. In this study, we isolated a cDNA encoding LeMRP, an ATP-binding cassette transporter from L. erythrorhizon, and further investigated its functions in the transport and biosynthesis of shikonin using the yeast transformation and transgenic hairy root methods, respectively. Real-time PCR was applied for expression analyses of LeMRP and shikonin biosynthetic enzyme genes. Functional analysis of LeMRP using the heterologous yeast cell expression system showed that LeMRP could be involved in shikonin transport. Transgenic hairy roots of L. erythrorhizon demonstrated that LeMRP overexpressing hairy roots produced more shikonin than the empty vector (EV) control. Real-time PCR results revealed that the enhanced shikonin biosynthesis in the overexpression lines was mainly caused by highly up-regulated expression of genes coding key enzymes (LePAL, HMGR, Le4CL and LePGT) involved in shikonin biosynthesis. Conversely, LeMRP RNAi decreased the accumulation of shikonin and effectively down-regulated expression level of the above genes. Typical inhibitors of ABC proteins, such as azide and buthionine sulphoximine, dramatically inhibited accumulation of shikonin in hairy roots. Our findings provide evidence for the important direct or indirect role of LeMRP in transmembrane transport and biosynthesis of shikonin.
Background
Recent advances in technology have enabled the development of various non‐invasive skin imaging tools to aid real‐time diagnosis of both benign and malignant skin tumours, minimizing the ...need for invasive skin biopsy. Multispectral optoacoustic tomography (MSOT) is a recently developed non‐invasive imaging tool, which offers the unique capacity for high resolution three dimensional (3D) optical mapping of tissue by further delivering highly specific optical contrast from a depth of several millimetres to centimetres in living tissues. MSOT enables volumetric, spectroscopic differentiation of tissue, both in vivo and in real time, with and without the application of biomarker‐specific probes, and is further able of providing spatial maps of skin chromophores, as well as underlying blood vasculature.
Methods
Three patients with suspicious skin tumours consented to have their lesions imaged with MSOT prior to excision. The histological findings and measurements were compared.
Results
We demonstrated the first in vivo clinical use of MSOT for 3D reconstruction of skin tumours in three patients with good histological correlation.
Conclusion
Our findings confirm the potential benefit of the new imaging method in guiding surgical intervention to achieve a more precise excision with better clearance and lower relapse rates. It can also potentially help to shorten the duration of Mohs’ micrographic surgery. Further large‐scale studies are necessary to ensure correlation between MSOT and histology.
We present a list of candidate gravitationally lensed dusty star-forming galaxies (DSFGs) from the HerMES Large Mode Survey and the Herschel Stripe 82 Survey. Together, these partially overlapping ...surveys cover 372 deg super(2) on the sky. After removing local spiral galaxies and known radio-loud blazars, our candidate list of lensed DSFGs is composed of 77 sources with 500 mum flux densities (S sub(500)) greater than 100 mJy. Such sources are dusty starburst galaxies similar to the first bright sub-millimeter galaxies (SMGs) discovered with SCUBA. We expect a large fraction of this list to be strongly lensed, with a small fraction made up of bright SMG-SMG mergers that appear as hyper-luminous infrared galaxies (L sub(IR)> 10 super(13)L sub(middot in circle)). Thirteen of the 77 candidates have spectroscopic redshifts from CO spectroscopy with ground-based interferometers, putting them at z> 1 and well above the redshift of the foreground lensing galaxies. The surface density of our sample is 0.21 + or - 0.03 deg super(-2). We present follow-up imaging of a few of the candidates to confirm their lensing nature. The sample presented here is an ideal tool for higher-resolution imaging and spectroscopic observations to understand the detailed properties of starburst phenomena in distant galaxies.
•The method can select the model class with suitable parameterized complexity.•Matching between measured modes and model predicted modes is avoided.•Information obtained in the calibration stage is ...utilized as pseudo-data.
There usually exist multitudinous finite element (FE) models with varying level of complexity which can be developed from the engineering judgment for the purpose of structural system identification and health monitoring. By following the theory of Bayesian evidence statistic, this paper proposes a methodology to investigate the issues of FE model-class selection for choosing suitable parameterized structural models utilized in dynamic reduction-based structural health monitoring (SHM). By employing the concept of information divergence, the amount of information needed to be extracted from the measured data is explicitly quantified during the procedure of FE model updating-based structural health monitoring. Then, for achieving a trade-off between the complexity of a parameterized FE model class and that of its corresponding information-theoretic interpretation, such information is utilized for penalizing the complexity of model class to ensure that a relatively simple parameterization scheme can be achieved. The proposed methodology consists of calibration and subsequent monitoring stages, and the information obtained in the former stage is utilized as pseudo-data which is learned by the latter stage to improve the model parameter estimation by implementing the delayed rejection adaptive Metropolis algorithm. Through numerical case studies conducted for a four-storey two-bay steel frame structure considering semi-rigid connections as well as laboratory experiment performed for a two-storey bolt-connected steel frame model, the feasibility and validity of proposed methodology is demonstrated.
Glioblastoma-associated macrophages are a major constituent of the immune response to therapy and are known to engulf the iron-based MR imaging contrast agent, ferumoxytol. Current ferumoxytol MR ...imaging techniques for localizing macrophages are confounded by contaminating intravascular signal. The aim of this study was to assess the utility of a newly developed MR imaging technique, segregation and extravascular localization of ferumoxytol imaging, for differentiating extravascular-from-intravascular ferumoxytol contrast signal at a delayed 24-hour imaging time point.
Twenty-three patients with suspected post-chemoradiotherapy glioblastoma progression underwent ferumoxytol-enhanced SWI. Segregation and extravascular localization of ferumoxytol imaging maps were generated as the voxelwise difference of the delayed (24 hours) from the early (immediately after administration) time point SWI maps. Continuous segregation and extravascular localization of ferumoxytol imaging map values were separated into positive and negative components. Image-guided biologic correlation was performed.
Negative segregation and extravascular localization of ferumoxytol imaging values correlated with early and delayed time point SWI values, demonstrating that intravascular signal detected in the early time point persists into the delayed time point. Positive segregation and extravascular localization of ferumoxytol imaging values correlated only with delayed time point SWI values, suggesting successful detection of the newly developed extravascular signal.
Segregation and extravascular localization of ferumoxytol MR imaging improves on current techniques by eliminating intrinsic tissue and intravascular ferumoxytol signal and may inform glioblastoma outcomes by serving as a more specific metric of macrophage content compared with uncorrected T1 and SWI techniques.
Abstract
We report on analysis of observations of the bright transient X-ray pulsar Swift J0243.6+6124 obtained during its 2017-2018 giant outburst with Insight-HXMT, NuSTAR, and Swift observatories. ...We focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-Eddington accretion rates, which we associate with the transition of the accretion disk to a radiation pressure dominated (RPD) state, the first ever directly observed for magnetized neutron star. This transition occurs at slightly higher luminosity compared to already reported transition of the source from sub- to super-critical accretion regime associate with onset of an accretion column. We argue that this scenario can only be realized for comparatively weakly magnetized neutron star, not dissimilar to other ultra-luminous X-ray pulsars (ULPs), which accrete at similar rates. Further evidence for this conclusion is provided by the non-detection of the transition to the propeller state in quiescence which strongly implies compact magnetosphere and thus rules out magnetar-like fields.
PDF
