Realization of broadband truly rainbow trapping in gradient-index metamaterials

Unidirectionally propagating wave (UPW) such as surface magnetoplasmon (SMP) has been a research hotspot in the last decades. In the study of the UPW, metals are usually treated as perfect electric conductors (PECs). However, it was reported that the transverse resonance condition induced by the PEC wall(s) may significantly narrow up the complete one-way propagation (COWP) band. In this paper, ultra-broadband one-way waveguides are built by utilizing the epsilon-negative (ENG) metamaterial (MM) and/or the perfect magnetic conductor (PMC) boundary. In both cases, the total bandwidth of the COWP bands are efficiently enlarged by more than three times than the one in the original metal-dielectric-semiconductor-metal structure. Moreover, the one-way waveguides consisting of gradient-index metamaterial are proposed to achieve broadband truly rainbow trapping (TRT). In the full-wave simulations, clear broadband TRT without back reflection is observed in terahertz regime. Besides, giant electric field enhancement is achieved in a PMC-based one-way structure, and the amplitude of the electric field is enormously enhanced by five orders of magnitude. Our findings are beneficial for researches on broadband terahertz communication, energy harvesting and strong-field devices.

A review about industrialization of Chinese materia medica decoction pieces

Chinese materia medica decoction pieces (CMMDPs), one of the three pillars of the Chinese materia medica industry, are a key link in the Chinese materia medica industrial chain. Industrialization is the only way for the modernization of CMMDPs. This review mainly summarizes the characteristics, history, current situation and prospect of CMMDPs industry, providing a new reference for promoting the flourishing development of the industrialization of CMMDPs and for serving massive health industry. The literature was collected from databases including Web of Science, PubMed, Elsevier and CNKI (Chinese). CMMDPs industry has the characteristics of regionalism, resource dependency, customer diversity and low industrial concentration. Deeply processed products include traditional Chinese medicine (TCM) formula granules, small-packed decoction pieces, ultrafine decoction pieces, puffed decoction pieces, compressed decoction pieces and instant decoction pieces. Integration of treatment and processing at the place of origin is emerging. However, there is still room for improvement, for example, the manufacturing technologies of CMMDPs industry need to be continually improved. The management of CMMDPs' normalized production also needs to be strengthened. The quality of CMMDPs should be strengthened supervision and it should establish the objective and feasible quality evaluation system for CMMDPs. At present, China has attached unprecedented importance to the development of TCM, and issued a number of supporting policies, sparing no effort to support its development.

Accurate prediction and genome-wide association analysis of digital intramuscular fat content in longissimus muscle of pigs

Intramuscular fat (IMF) content is a critical indicator of pork quality that affects directly the purchasing desire of consumers. However, to measure IMF content is both laborious and costly, preventing our understanding of its genetic determinants and improvement. In the present study, we constructed an accurate and fast image acquisition and analysis system, to extract and calculate the digital IMF content, the proportion of fat areas in the image (PFAI) of the longissimus muscle of 1709 animals from multiple pig populations. PFAI was highly significantly correlated with marbling scores (MS; 0.95, r²  = 0.90), and also with IMF contents chemically defined for 80 samples (0.79, r²  = 0.63; more accurate than direct analysis between IMF contents and MS). The processing time for one image is only 2.31 s. Genome-wide association analysis on PFAI for all 1709 animals identified 14 suggestive significant SNPs and 1 genome-wide significant SNP. On MS, we identified nine suggestive significant SNPs, and seven of them were also identified in PFAI. Furthermore, the significance (-log P) values of the seven common SNPs are higher in PFAI than in MS. Novel candidate genes of biological importance for IMF content were also discovered. Our imaging systems developed for prediction of digital IMF content is closer to IMF measured by Soxhlet extraction and slightly more accurate than MS. It can achieve fast and high-throughput IMF phenotype, which can be used in improvement of pork quality.

Controlled generation of luminescent centers in hexagonal boron nitride by irradiation engineering

Luminescent centers in the two-dimensional material hexagonal boron nitride have the potential to enable quantum applications at room temperature. To be used for applications, it is crucial to generate these centers in a controlled manner and to identify their microscopic nature. Here, we present a method inspired by irradiation engineering with oxygen atoms. We systematically explore the influence of the kinetic energy and the irradiation fluence on the generation of luminescent centers. We find modifications of their density for both parameters, while a fivefold enhancement is observed with increasing fluence. Molecular dynamics simulations clarify the generation mechanism of these centers and their microscopic nature. We infer that V_NC_B and [Formula: see text] are the most likely centers formed. Ab initio calculations of their optical properties show excellent agreement with our experiments. Our methodology generates quantum emitters in a controlled manner and provides insights into their microscopic nature.

[The role of time-series propagation map and activity path of confirmed cases in the analysis and determination of COVID-19 epidemic]

Objective: The time sequence transmission map and the cases travel track were used to explain the chain of transmission, describe the characteristics of transmission and analyze the mode of epidemic of novel coronavirus pneumonia, so as to provide evidence for the relevant government departments to carry out epidemic prevention and control. Methods: The time sequence transmission map and the cases travel track table were drawn, according to the time of incidence, age, sex, number of close contacts and their interrelations. Results: At the end of February 10, 2020, 63 COVID-19 cases were reported in the research area. Among them, 57 cases were confirmed (1 deaths) and 6 cases were asymptomatic, 57 cases were imported cases (90.48%), 36 cases were reported by cluster epidemic (57.14%) among friends and relatives. Cases have been spread to the fourth generation. Conclusion: The time sequence transmission map and the cases travel track showed that, in the research area, the epidemic situation of COVID-19 was mainly caused by imported case, and the clustering transmission was the major spread model. The time sequence transmission map and the cases travel track are worth popularizing in the prevention and control of major infectious diseases.

Silicon Photonic Polarization Multiplexing Sensor with Both Large Range and High Resolution

A silicon photonic polarization multiplexing (PM) sensor featuring both a large range and a high resolution is proposed and experimentally demonstrated. The sensor includes a Fabry-Pérot (FP) resonator and a microring resonator (MRR) functioning as the sensing parts. With PM technology, the FP resonator only works on the transverse-electric mode while the MRR only on the transverse-magnetic mode. Thus, the proposed sensor can simultaneously achieve a large range with a short FP resonator and a high resolution with a high-Q MRR. Measured results show a range of 113 °C and a resolution of 0.06 °C for temperature sensing, and a range of 0.58 RIU (refractive index unit) with the resolution of 0.002 RIU for analyte refractive index sensing.

Clinical features and survival impact of EBV-positive diffuse large B-Cell lymphoma with different age cutoffs

OBJECTIVE

In 2016 WHO classification, EBV +DLBCL of the elderly was replaced by EBV+ DLBCL NOS. This is due to the fact that many young patients of EBV+ DLBCL were found in recent years.

PATIENTS AND METHODS

In this study, we retrospectively analyzed clinical features and survival outcomes of EBV positive DLBCL patients in different age groups. All the patients treated at a single center.

RESULTS

When we use different ages (40, 50 and 60 years old) as cutoffs, the prevalence of EBV positive DLBCL was 12.0%, 12.3% and 13.0% in younger patients and 19.0%, 15.4% and 13.8% in elder patients respectively. Whatever the age cutoff was, EBV positive associated with unfavorable clinical prognosis in elder groups. When we use 40 and 50 years old as age cutoffs, poor impacts of EBV positive on overall survival and progression-free survival were observed only in elder patients, but not in younger patients. It should be noted that when we use 60 years old as age cutoff, the results were the opposite.

CONCLUSIONS

EBV+ DLBCL patients with age of 40 to 60 years old showed poorer prognostic features than EBV- DLBCL patients; however, patients in other age groups did not show evident differences in prognosis between EBV+ DLBCL patients and EBV- DLBCL patients. This finding was not reported before.

miR-18a expression in basal cell carcinoma and regulatory mechanism on autophagy through mTOR pathway

BACKGROUND

Basal cell carcinoma (BCC) is the most common form of skin carcinoma.

AIM

To investigate the function of key micro(mi)RNAs and to explore the potential molecular mechanisms involved in BCC.

METHODS

The microarray dataset GSE34535, which comprises seven BCC samples and seven control samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs (DE-miRNAs) were identified. We collected tissue samples from 20 patients with BCC and 20 healthy controls (HCs), to compare the miR-18a expression in their tissue samples. Expression of miR-18a in A431 and HaCaT cells was also assayed. Following this, we upregulated and downregulated miR-18a expression in A431 cells to examine the effects on cell proliferation, migration and apoptosis. To further investigate the relative mechanism, the proteins LC3, Beclin 1, Akt and mammalian target of rapamycin (mTOR) were examined by quantitative real-time PCR and Western blotting. For further verification, we examined the expression of LC3 in the 20 BCC and 20 HC tissue samples.

RESULTS

In total, 19 DE-miRNAs (13 upregulated and 6 downregulated) that were common to the BCC and HC groups were identified. Levels of miR-18a were about three-fold higher in BCC tissues and A431 cells compared with their respective control groups. In vitro, downregulation of miR-18a was shown to inhibit cell proliferation and activate autophagy via the Akt/mTOR signalling pathway, while upregulation of miR-18a promoted proliferation of these cells. LC3 was decreased in BCC compared with HC tissue samples.

CONCLUSIONS

Our data support an oncogenic role of miR-18a through a novel Akt/mTOR/Beclin 1/LC3 axis, and suggest that the antitumour effects of miR-18a inhibitor may make it suitable for BCC therapy.

Metallic elements and Pb isotopes in PM2.5 in three Chinese typical megacities: spatial distribution and source apportionment

Heavy metal pollution in fine particulate matter (PM_2.5) is a serious environmental and health concern in China, particularly during winter. Here, we detected 40 elements in 24 h integrated daily PM_2.5 samples collected in January 2014 from three typical Chinese metropolises (Beijing, Changchun, and Chengdu) to reflect elemental spatial variations, local sources, and regional transport. The measured elemental concentrations in Changchun were 11.1% and 48.4% higher than those in Beijing and Chengdu, respectively. Thus, PM_2.5 from Changchun exhibited high levels and diversity in the elemental profile (characterized by high concentrations of industrial emission elemental markers). The results of elemental ratios and Pb isotopes proved that, except for a coal combustion source, vehicular emissions contributed more to PM_2.5 heavy metals in Beijing than in the other two cities; Changchun PM_2.5 elements received large contributions from industrial sources, including iron and steel manufacturing, and automobile industry. Moreover, crustal dust from long-range transport of regional air masses from the northwest regions of China played a crucial role in determining elemental levels in Beijing and Changchun, accounting for more than 50% of source intensity. However, a specific dominant source was not determined in Chengdu; the contribution of anthropogenic dust, mainly from construction activities, needs to be paid attention in Chengdu eastern area. This study contributed to enhancing our understanding of elemental spatial distribution characteristics and sources and to setting more judicious standards and strategies for PM_2.5 bound heavy metals in China.

Logistic regression analysis of risk factors for upper gastrointestinal bleeding induced by PCI in combination with double antiplatelet therapy for STEMI patients

OBJECTIVE

To analyze the risk factors for upper gastrointestinal bleeding (UGIB) in patients with ST-segment elevation myocardial infarction (STEMI) during double antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI).

METHODS

A total of 388 patients treated from January 2015 to September 2017 due to STEMI were selected. Thirty-two cases of UGIB occurring during DAPT after PCI were included as a UGIB group, and another 356 cases without UGIB were set as a control group. Age, gender, body mass index, smoking, drinking, history of previous diseases (hypertension, diabetes and digestive tract diseases), infection of Helicobacter pylori (Hp), combined use of other drugs (statins, NSAIDs, β receptor blockers, PPI, H2RA and dabigatran etexilate), as well as serum levels of creatinine (Cr), alanine transaminase (ALT) and C-reactive protein (CRP) were compared. The risk factors for UGIB were subjected to univariate and logistic regression analyses.

RESULTS

Compared with the control group, the UGIB group had significantly longer hospital stay, and higher proportion of discontinuation of antithrombotic drugs and mortality rate (P<0.05). Logistic regression analysis showed that age (P=0.002), smoking (P=0.000), Hp infection (P=0.020), history of digestive tract diseases (P=0.030) and renal insufficiency (P=0.041) were independent risk factors for UGIB, and use of PPI (P=0.028) was a protective factor for UGIB.

CONCLUSIONS

Old age, smoking, Hp infection, history of digestive tract diseases and renal insufficiency are risk factors for UGIB caused by PCI combined with DAPT in patients with STEMI. Proper use of PPI thereafter can reduce the incidence rate of UGIB.

Magnetic field assisted beam-scanning leaky-wave antenna utilizing one-way waveguide

We propose a Leaky-Wave Antenna (LWA) based on one-way yttrium-iron-garnet (YIG)-air-metal waveguide. We first analyze the dispersion of the LWA, showing the one-way feature and the radiation loss. Owing to the unique one-way dispersive property, the beam radiated from the LWA can have very narrow beam width, at the same time having large scanning angle. The main beam angle obtained by full-wave simulation is consistent with our theoretical prediction with the aid of the dispersion. For a given frequency, we can realize continuous beam scanning by varying the magnetic field, where the 3 dB beam width is much narrower than previously demonstrated. Our results pave a new way to realize continuous angle scanning at a fix frequency for modern communications.