Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Progress in research of rash and fever syndrome surveillance and early warning]

Objective: To introduce the progress in research of rash and fever syndrome (RFS) surveillance and early warning both at home and abroad, and provide reference for surveillance and prevention of RFS in China. Methods: The keywords "fever" "rash" and "surveillance" and others were used for a literature retrieval by using China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed and Web of Science. The languages of literatures were limited in Chinese and English. The key information of the literatures were collected and analyzed with Excel. Results: A total of 36 study papers (21 in Chinese and 15 in English) were included. The studies mainly focused on the pathogen surveillance of RFS (n=19). The pathogens included measles virus, varicella-zoster virus, rubella virus, enterovirus, human B19 virus, dengue virus, streptococcus group A, Salmonella typhi and Salmonella paratyphoid,human herpesvirus, mumps virus and adenovirus. Eight studies were about the surveillance in major events, such as sport game, World Expo and religious gathering, or sudden natural disasters, such as earthquake and tropical storm, during 2010-2015. Eight studies focused on case or epidemic surveillance, most of which were studies from other counties. The surveillance sites were medical institutions. RFS was diagnosed according to the International Classification of Diseases, 9th (ICD-9) and symptoms descripted in chief-complaint. Only one study in Mongolia conducted RFS epidemic prediction. The analysis methods of 36 papers included simple descriptive analysis, time-based early warning models (such as regression analysis, fixed threshold method, Hugh Hart control chart method and cumulative sum control chart method) and time series analysis method. Conclusions: In the future, RFS surveillance system should cover both known pathogens and emerging pathogens. Automatic surveillance using information capture and intelligent modelling can be applied to improve the sensitivity and specificity of RFS surveillance and early warning.

Application opportunity of Doppler ultrasound combined with CT angiography in diabetic lower extremity arterial disease and the analysis of the risk factors

Objective

This study examined the potential of combining Doppler ultrasound (DUS) and CT angiography (CTA) for early detection and intervention of lower extremity arterial disease (LEAD) in diabetes.Concurrently, risk factors influencing LEAD progression were analyzed.

Methods

106 Type-2 diabetes patients with LEAD, having undergone DUS and CTA, were divided into four stages according to Fontaine stage. Results of DUS and CTA were compared across stages and potential risk factors were analyzed.

Results

Positive detection rates of LEAD differed between DUS and CTA for Fontaine stages I and II (P < 0.05), with no significant difference for stages III and IV (P > 0.05). CTA identified subgroups with mild to moderate stenosis and severe stenosis or occlusion, with positive rates on DUS of 17.95% and 89.9% respectively. Hypertension was found as an independent risk factor affecting LEAD progression.

Conclusion

CTA should be performed early for LEAD in diabetes patients at Fontaine stages I and II, regardless of DUS results. For diabetes patients with LEAD, stringent blood pressure control is crucial to delay disease progression.

Adventitious root culture of Lessertia frutescens for the production of triterpenoid saponins and polysaccharides

Lessertia frutescens is a perennial shrub of commercial importance in South Africa, but the scarcity of plant resources has limited current product production. In this study, to provide an alternative approach for obtaining L. frutescens material, adventitious roots (ARs) were induced from sterilized seedlings and cultured in a suspension culture system. During this process, selection tests were conducted to find a suitable auxin and its concentration for AR induction and a suitable basal medium for AR growth and metabolite accumulation; a kinetic study was then performed to constructure kinetic models. The results showed that compared to other auxins and concentrations, indole-3-butyric acid at 3 mg/L was suitable for increasing the number and length of ARs during AR induction. In AR suspension culture, Schenk and Hildebrandt (SH) was better than other basal media, and the maximum AR fresh (86.9 g/L) or dry weight (5.5 g/L), total triterpenoid saponin (92.6 mg/g DW), and polysaccharide (114.7 mg/g DW) contents were determined in the 1.5×SH medium. In addition, AR biomass and metabolite contents reached the maximum on day 42. The kinetic models for AR growth and triterpenoid and polysaccharide production were constructed, providing the basis for further optimization of culture conditions and large-scale culture.

Evaluation of the "Relative Ordered Structure of Hericium erinaceus Polysaccharide" from Different Origins: Based on Similarity and Dissimilarity

Polysaccharides are organic compounds widely distributed in nature, but structural order and disorder remain a formidable problem. In this study, based on the theoretical framework of the "relative ordered structure of polysaccharide" proposed in our previous work, the structural order of Hericium erinaceus polysaccharides from different regions was evaluated by FT-IR, methylation analysis, and 1H NMR spectroscopy combined with chemometric methods. The results of principal component analysis and heatmap cluster analysis revealed that 18-subfractions exhibit four different structural types with representative glycoside linkage types: fucogalactoglucan, glucofucogalactan, fucoglucan, and glucan. The main chain of heteroglucans often consists of β-(1 → 6)-Glcp, β-(1 → 4)-Glcp, and β-(1 → 3)-Glcp residues, which are predominantly substituted at the O-3 and O-6 positions. The main chain structure of heterogalactans is α-(1 → 6)-Galp residues, which may be replaced by Fucp and Galp residues at O-2. Overall, our findings demonstrate the validity of the "relative ordered structure of polysaccharide" in Hericium erectus polysaccharides and simplify the complexity of polysaccharide structures.

Exploring the partial degradation of polysaccharides: Structure, mechanism, bioactivities, and perspectives

Polysaccharides are promising biomolecules with lowtoxicity and diverse bioactivities in food processing and clinical drug development. However, an essential prerequisite for their applications is the fine structure characterization. Due to the complexity of polysaccharide structure, partial degradation is a powerful tool for fine structure analysis, which can effectively provide valid information on the structure of backbone and branching glycosidic fragments of complex polysaccharides. This review aims to conclude current methods of partial degradation employed for polysaccharide structural characterization, discuss the molecular mechanisms, and describe the molecular structure and solution properties of degraded polysaccharides. In addition, the effects of polysaccharide degradation on the conformational relationships between the molecular structure and bioactivities, such as antioxidant, antitumor, and immunomodulatory activities, are also discussed. Finally, we summarize the prospects and current challenges for the partial degradation of polysaccharides. This review will be of great value for the scientific elucidation of polysaccharide fine structures and potential applications.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Improving Flavonoid Accumulation of Bioreactor-Cultured Adventitious Roots in Oplopanax elatus Using Yeast Extract

Oplopanax elatus is an endangered medicinal plant, and adventitious root (AR) culture is an effective way to obtain its raw materials. Yeast extract (YE) is a lower-price elicitor and can efficiently promote metabolite synthesis. In this study, the bioreactor-cultured O. elatus ARs were treated with YE in a suspension culture system to investigate the elicitation effect of YE on flavonoid accumulation, serving for further industrial production. Among YE concentrations (25-250 mg/L), 100 mg/L YE was the most suitable for increasing the flavonoid accumulation. The ARs with various ages (35-, 40-, and 45-day-old) responded differently to YE stimulation, where the highest flavonoid accumulation was found when 35-day-old ARs were treated with 100 mg/L YE. After YE treatment, the flavonoid content increased, peaked at 4 days, and then decreased. By comparison, the flavonoid content and antioxidant activities in the YE group were obviously higher than those in the control. Subsequently, the flavonoids of ARs were extracted by flash extraction, where the optimized extraction process was: 63% ethanol, 69 s of extraction time, and a 57 mL/g liquid-material ratio. The findings provide a reference for the further industrial production of flavonoid-enriched O. elatus ARs, and the cultured ARs have potential application for the future production of products.

[The correlations between influenza and meteorological factors in 15 cities of northern China, 2008-2020]

Objective: To understand the influence of meteorological factors on the morbidity of influenza in northern cities of China and explore the differences in the influence of meteorological factors on the morbidity of influenza in 15 cities. Methods: The monthly reported morbidity of influenza and monthly meteorological data from 2008 to 2020 were collected in 15 provincial capital cities, including Xi 'an, Lanzhou, Xining, Yinchuan and Urumqi (5 northwestern cities), Beijing, Tianjin, Shijiazhuang, Taiyuan, Hohhot, Ji'nan, Zhengzhou (7 northern cities), Shenyang, Changchun and Harbin (3 northeastern cities). The panel data regression model was applied to conduct quantitative analyze on the influence of meteorological factors on influenza morbidity. Results: The univariate and multivariate panel regression analysis showed that after controlling the population density and other meteorological factors, for each 5 ℃ drop of monthly average temperature, the morbidity change percentage (MCP) of influenza was 11.35%, 34.04% and 25.04% in the 3 northeastern cities, 7 northern cities and 5 northwestern cities, respectively, and the best lag period months was 1, 0 and 1 month; When the monthly average relative humidity decreased by 10%, the MCP was 15.84% in 3 cities in northeastern China and 14.80% in 7 cities in northern China respectively, and the best lag period months was 2 and 1 months respectively; The MCP of 5 cities in northwestern China was 4.50% for each 10 mm reduction of monthly accumulated precipitation, and the best lag period months was 1 month; The MCPs of 3 cities in northeastern China and 5 cities in northwestern China were 4.19% and 5.97% respectively when the accumulated sunshine duration of each month decreased by 10 hours, the best lag period months was 1 month. Conclusions: In northern cities of China from 2008 to 2020, the temperature, relative humidity, precipitation and sunshine duration all had negatively impact on the morbidity of influenza, and temperature and relative humidity were the main sensitive meteorological factors. Temperature had a strong direct impact on the morbidity of influenza in 7 cities in northern China, and relative humidity had a strong lag effect on the morbidity of influenza in 3 cities in northeastern China. The duration of sunshine in 5 cities in northwestern China had a greater impact on the morbidity of influenza compared with 3 cities in northeastern China.

[Assessment of intensity of seasonal influenza activity in Beijing-Tianjin-Hebei region, 2019-2021]

Objective: To explore the feasibility of moving epidemic method (MEM) in the assessment of seasonal influenza (influenza) activity intensity from the perspective of urban agglomeration, assess influenza activity intensity in the Beijing-Tianjin-Hebei region from 2019 to 2021 and evaluate the reliability of surveillance data and the effectiveness of the MEM model application. Methods: The weekly reported incidence rate (IR) of influenza and the percentage of influenza-like illness (ILI%) from 2011-2021 in Beijing-Tianjin-Hebei region were collected to establish MEM models respectively. The model fitting effect and the reliability of the two data were evaluated for the purpose of establishing an optimal model to assess the influenza activity intensity in Beijing-Tianjin-Hebei region from 2019-2021. A cross-validation procedure was used to evaluate the performance of the models by calculating the Youden's index, sensitivity and specificity. Results: The MEM model fitted with weekly ILI% had a higher Youden's index compared with the model fitted with weekly IR at both Beijing-Tianjin-Hebei region level and provincial level. The MEM model based on ILI% showed that the epidemic threshold in Beijing-Tianjin-Hebei region during 2019-2020 was 4.42%, the post-epidemic threshold was 4.66%, with medium, high and very high intensity thresholds as 5.38%, 7.22% and 7.84%, respectively. The influenza season during 2019-2020 had 10 weeks (week 50 of 2019 to week 7 of 2020). The influenza season started in week 50 of 2019, and the intensity fluctuated above and below medium epidemic level for six consecutive weeks. The high intensity was observed in week 4 of 2020, the threshold of very high intensity was excessed in week 5, and the intensity gradually declined and became lower than the threshold at the end of the influenza season in week 8. The epidemic threshold was 4.29% and the post-epidemic threshold was 4.35% during 2020-2021. Influenza activity level never excessed the epidemic threshold throughout the year, and no epidemic period emerged. Conclusions: The MEM model could be applied in the assessment of influenza activity intensity in Beijing-Tianjin-Hebei region, and the use of ILI% to assess influenza activity intensity in this region was more reliable than IR data. Influenza activity intensity in Beijing-Tianjin-Hebei region was higher during 2019-2020 but significantly lower in 2020-2021.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Recent advances in research of modes of hepatocyte death in anti-tuberculosis drug-induced liver injury

Antituberculosis drug-induced liver injury (ATB-DILI) is the most common and most serious side effect of antituberculous drug therapy, which brings great challenges to drug treatment of tuberculosis. Isoniazid and rifampicin as first-line anti-tuberculosis drugs produce a variety of toxic metabolites that directly cause liver cell necrosis, and a large amount of free radicals that induce oxidative stress, leading to programmed death of liver cells such as apoptosis, ferroptosis, and autophagy. Iron death is a recently discovered mode of cell death, and its role in ATB-DILI has not been fully elucidated. Blocking the pathway of hepatocyte death is an important means to treat ATB-DILI. In this paper, we discuss the mechanism and characteristics of different cell death modes in order to help identify new diagnostic markers and therapeutic drug targets.

A New Species of Free-living Marine Nematode (Ptycholaimellus: Chromadoridae: Chromadorida: Nematoda) from Mangrove Wetlands in China

This study presents a new species of free-living marine nematode, Ptycholaimellus luoyang sp. nov., from mangrove wetlands in China. The identification was confirmed by analyzing morphological characteristics and three genes: COI, 18S rDNA, and 28S rDNA. This species is distinguished from allied species by its short cephalic setae, cylindrical pharynx with anterior swelling, sclerotized transverse ridges occurring near the dorsal tooth, rod-like gubernaculum and proximal, arch-like, slightly waved, middle curved, and distally pointed spicules. The Bayesian topology was regarded as morphological evidence of P. luoyang sp. nov. being a distinct species. Interspecific and intrageneric thresholds of the K2P distance divergence have been presented here for the first time.

METTL3 modulates m6A modification of CDC25B and promotes head and neck squamous cell carcinoma malignant progression

BACKGROUND

N6-methyladenosine (m6A) RNA methylation and its methyltransferase METTL3 have been widely reported to be involved in different cancers by regulating RNA metabolism and function. Here, we aimed to explore the biological function and clinical significance of m6A modification and METTL3 in head and neck squamous cell carcinoma (HNSCC).

METHODS

The prognostic value of METTL3 expression was evaluated using tissue microarray and immunohistochemical staining analyses in a human HNSCC cohort. The biological role and mechanism of METTL3 in HNSCC tumour growth, metastasis and angiogenesis were determined in vitro and in vivo.

RESULTS

M6A levels and METTL3 expressions in HNSCC tissues were significantly increased compared with paired adjacent tissues. Meanwhile, METTL3 was an independent risk factor for the prognosis of HNSCC patients. Moreover, METTL3 overexpression promoted HNSCC cell proliferation, migration, invasion, and angiogenesis, while knockdown of METTL3 had an opposite effect in vivo and in vitro. Mechanistically, METTL3 enhanced the m6A modification of CDC25B mRNA, which maintained its stability and upregulated its expression, thereby activating G2/M phase of cell cycle and leading to HNSCC malignant progression.

CONCLUSIONS

METTL3 may be a potential prognostic biomarker and therapeutic target for HNSCC.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Resonant sheath heating in weakly magnetized capacitively coupled plasmas due to electron-cyclotron motion

An electron heating mechanism based on a resonance between the cyclotron motion of electrons and the radio frequency sheath oscillations is reported in weakly magnetized capacitively coupled plasmas at low pressure. If half of the electron cyclotron period coincides with the radio frequency period, then electrons will coherently collide with the expanding sheath and gain substantial energy, which enhances the plasma density. A relation between the magnetic field and the driving frequency is found to characterize this resonance effect and the kinetics of electrons are revealed at resonance conditions for various driving frequencies.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

A functional variant in the promoter region of IGF1 gene is associated with chicken abdominal fat deposition

Insulin-like growth factor 1 (IGF1) plays an important role in the regulation of cell growth, proliferation, differentiation, and apoptosis. Previously several studies revealed that genotypes of chicken IGF1 c.-366A > C were significantly associated with abdominal fat weight and body weight in chickens. But the underlying mechanism is still unknown. To investigate the mechanism underlying the association, herein, we performed IGF1 gene mRNA expression profiling, a dual-luciferase reporter assay and electrophoretic mobility shift assay (EMSA). Quantitative real-time PCR results showed that IGF1 gene was widely expressed in 14 tissues. The mRNA expression levels of IGF1 gene in both abdominal fat and jejunum were significantly higher in fat broilers than in lean broilers. However, the opposite results were observed in the pancreas. The reporter gene assay showed that the promoter luciferase activity of allele A was significantly higher than that of allele C (P < 0.05). In addition, the luciferase activity of allele A promoted by the transcription factor AP1 and OCT1 was higher than that of allele C (P < 0.05). Electrophoretic mobility shift assay result showed that allele A binding to the transcription factor AP1 and OCT1 was stronger than that of allele C. All in all, our data indicated that the IGF1 gene c.-366A > C is a functional SNP responsible for chicken adipose deposition.

[Clinical features of intracranial vessel involvement in Takayasu's arteritis]

Objective: To analyze clinical characteristics of intracranial vessel involvement in Takayasu's arteritis (TA). Methods: Retrospectively analyzed 135 hospitalized TA patients' clinical data in Beijing Anzhen Hospital from November 2012 to November 2018. Based on intracranial artery (IA) complicated or not, TA patients were divided into two groups:32 patients within involvement and 103 patients without involvement. The difference in comparison of imaging types, basic data and laboratory test were analyzed. Results: The proportion of TA patients with intracranial vascular involvement was 23.7% (32/135) and the most common site was internal carotid artery (intracranial segment) (59.4%, 19/32). The incidences of hypertension and coronary heart disease were significantly higher in TA patients with intracranial vascular involvement compared with the patients without intracranial involvement (46.9% vs 26.2%, 21.9% vs 6.8%, χ(2)=4.863, 4.460, all P<0.05). The rate of tocilizumab treatment in the intracranial vascular involved group was higher than that in the group without intracranial vascular involvement (40.6% vs 19.4%, χ(2)=5.945, P<0.05). The platelet count in patients with intracranial involvement group was significantly lower than that in patients without intracranial involvement group [(218±55)×10(9)/L vs (272±71)×10(9)/L, t=-3.570, P<0.01], while the hemoglobin [(130±17) vs (121±18) g/L, t=2.363, P<0.05] and triglyceride [1.22(0.75, 1.64) vs 0.92(0.63, 1.21) mmol/L, U=1 017.000, P<0.01] were significantly higher than those without intracranial vascular involvement. Moreover, coronary artery involvement presented more frequently in the intracranial vascular involved group than the group without intracranial vascular involvement (43.8% vs 14.6%, χ(2)=12.331, P<0.01). Logistic regression analysis showed that the incidence of intracranial vascular disease in TA patients with coronary artery involvement was 4 times higher than that in patients without coronary artery lesions (OR=3.965, 95%CI:1.584-9.926, P=0.003). Conclusion: The proportion of intracranial vascular involvement in TA is not rare, TA patients with cardiovascular risk factors should be considered to strengthen imaging examination of intracranial vessels.

Single-Fiber Laser Ablation in Treating Selected Metastatic Lymph Nodes of Papillary Thyroid Carcinoma and Benign Cold Thyroid Nodules-Preliminary Results

Background and Objectives

To evaluate the feasibility and efficacy of single‐fiber laser ablation (LA) under ultrasound guidance and appropriate ablation modes in the treatment of selected metastatic lymph nodes of papillary thyroid carcinoma (PTC) and benign cold thyroid nodules

Study Design/Materials and Methods

A total of 18 patients (consisting of 8 patients with 18 metastatic lymph nodes of PTC and 10 patients with 10 benign cold thyroid nodules) each underwent one session of single‐fiber LA under ultrasound guidance. On the basis of the sizes of the nodules, the ablation modes were chosen accordingly. The single‐dot ablation mode was used in the nodules with three orthogonal diameters measuring no greater than 10 mm in diameter, with a dot, a level and an insertion. The double‐dots overlapping ablation mode was used in the nodules with the largest diameters measuring greater than 10 mm (in which the nodules measured no more than 15 mm in diameter and with the other two perpendicular diameters measuring no greater than 10 mm in diameter) with two dots, a level and two insertions. The multiple levels and dots overlapping ablation mode was used in the nodules with the three orthogonal diameters all measuring larger than 10 mm, with multiple dots, levels and insertions.

Results

After 12 months of follow‐up in the treated nodules of the metastatic lymph nodes of PTC and benign cold thyroid nodules, the mean baseline volumes decreased from 0.29 ± 0.12  to 0.03 ± 0.03 ml and 3.85 ± 0.64 to 1.1 ± 0.37 ml, respectively, and the mean volume reduction ratios (VRRs), which was calculated as {[(initial volume−final volume) × 100%]/initial volume}, were 90.3 ± 7.6% and 72 ± 5.8%, respectively. There were six ablative zones that completely disappeared, whereas the ablative zones that still existed presented as scar‐like areas or small hyperechoic areas that were compatible with scar tissue among the 18 malignant nodules at the last follow‐up.

Conclusions

Single‐fiber LA under ultrasound guidance, with the appropriate ablation modes, is feasible and effective for the treatment of selected metastatic lymph nodes of PTC and benign cold thyroid nodules. This study suggests that single‐fiber LA may be applied to selected cases with appropriate ablation modes. Lasers Surg. Med. 2019 © 2019 Wiley Periodicals, Inc.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100  TeV. As a result, we observed 24 photonlike events with E>100  TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100  TeV from an astrophysical source.

[Spontaneous focal lamina cribrosa defect in glaucoma and its relationship with nonprogressive glaucomatous neuropathy]

Objective: To investigate the relationship between the spontaneous focal lamina cribrosa (LC) defect and the progression of visual field defect (VFD) in primary open-angle glaucoma (POAG). Methods: Case-control study. The patients who were diagnosed as POAG with at least 5 visual field results had been collected from June 2018 to January 2019 at Beijing Tongren Hospital Affiliated to Capital Medical University. Serial imaging by swept source optical coherence tomography B-Scan of the optic discs were acquired at the end of the follow-up and LC defects status were reviewed. Intraocular pressure, mean defects of visual field, central corneal thickness and axis length were recorded in the follow-up duration. Eyes were classified as having either progressive or nonprogressive VFD, and associating factors were evaluated by χ(2) or Fisher's test, mixed-effect model analysis and multivariate Logistical regression analysis. Results: A total of 32 subjects (64 eyes) were enrolled in the study with mean age of (47±14) years, the group consisted of 17 males and 15 females. Fourty-five eyes showed nonprogressive VFD. LC defects were more common in eyes without (28/45) rather than with progressive VFD (5/19) (χ(2)=6.896, P=0.009). Eyes with nonprogressive VFD showed longer axis length[(26.82±1.34) mm vs. (25.79±1.44) mm; t=6.589, P=0.013] and wider LC defects diameter[211 (165-326) μm vs. 114 (106-156) μm; Z=4.797, P=0.042]. Multivariate Logistic regression analysis revealed that the presence of LC defect was significantly associated with nonprogressive VFD (odds ratio=0.217, P=0.012). There were 7 subjects with asymmetry VFD and the incedence of LC defects without progression (7/7) is higher than fellow eye with progression (1/7, P=0.002). There was only one patient with progressive VFD showed one LC defect with an smaller diameter (169 μm) than that in the contralateral eyes with stable VFD (269 μm). Conclusions: LC defects are more common in eyes with nonprogressive VFD. Spontaneous LC defects are associated with nonprogressive glaucomatous defects and could be a protective factor for POAG. (Chin J Ophthalmol, 2019, 55:338-346).

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

Efficacy, safety and influencing factors of intra-calf muscular injection of bone marrow mononuclear cells in the treatment of type 2 diabetes mellitus-induced lower extremity vascular disease

The efficacy, safety and impact of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) associated with the intra-calf muscular injection of bone marrow mononuclear cells (BMMCs) in the treatment of type 2 diabetes mellitus (T2DM)-induced lower extremity vascular disease (LEVD) were evaluated. Patients with T2DM-LEVD were randomly divided into a control group and BMMCs group to assess the efficacy and safety of the treatment; serum VEGF and bFGF levels were detected. The BMMCs group was divided into superior genicular artery (SGA) and inferior genicular artery (IGA) subgroups as well as low-dose and high-dose subgroups for the comparison of efficacy indices. The BMMCs group exhibited significantly improved indices (P<0.05) compared with the control group and no fatalities or cancer occurred. There were no significant changes in serum VEGF and bFGF levels (P>0.05). The claudication distance in the IGA subgroup was significantly greater that in the SGA subgroup (P<0.05); the low-dose subgroup and the high-dose subgroup did not demonstrate any significant differences in each index (P>0.05). BMMC treatment for T2DM-LEVD was found to be safe and effective and had no significant impact on serum VEGF and bFGF levels in the short term; However, the degree of LEVD may affect its efficacy.

Injection of Toll-like receptor 4 siRNA into the ventrolateral periaqueductal gray attenuates withdrawal syndrome in morphine-dependent rats

We assessed the role of the Toll-like receptor 4 (TLR4) gene in the ventrolateral periaqueductal gray (vlPAG) region of morphine-dependent rats on attenuating withdrawal syndrome, and regulating glutamic acid decarboxylase (GAD67), glutamic acid (Glu), and gamma-aminobutyric acid (GABA). After siRNA-mediated downregulation of TLR4, changes were observed in withdrawal behavior and downstream signaling molecules. Rats were injected into the vlPAG with TLR4 siRNA, followed by intraperitoneal injection of morphine for 5 consecutive days, and then naloxone, and the behavioral indices of morphine withdrawal were observed. 'Wet-dog' shakes, teeth chattering, and the total scores of withdrawal reactions were reduced. TLR4 expression and Glu levels were reduced, whereas GAD67 and GABA levels were increased. Overall, these findings indicate that modifying TLR4 gene expression in the vlPAG stimulates expression of the downstream signaling molecule, GAD67, which decreases Glu levels and increases GABA levels. This mechanism may explain the inhibition of withdrawal syndrome in morphine-dependent rats.

Co-expression of Cyanobacterial Genes for Arsenic Methylation and Demethylation in Escherichia coli Offers Insights into Arsenic Resistance

Arsenite [As(III)] and methylarsenite [MAs(III)] are the most toxic inorganic and methylated arsenicals, respectively. As(III) and MAs(III) can be interconverted in the unicellular cyanobacterium Nostoc sp. PCC 7120 (Nostoc), which has both the arsM gene (NsarsM), which is responsible for arsenic methylation, and the arsI gene (NsarsI), which is responsible for MAs(III) demethylation. It is not clear how the cells prevent a futile cycle of methylation and demethylation. To investigate the relationship between arsenic methylation and demethylation, we constructed strains of Escherichia coli AW3110 (ΔarsRBC) expressing NsarsM or/and NsarsI. Expression of NsarsI conferred MAs(III) resistance through MAs(III) demethylation. Compared to NsArsI, NsArsM conferred higher resistance to As(III) and lower resistance to MAs(III) by methylating both As(III) and MAs(III). The major species found in solution was dimethylarsenate [DMAs(V)]. Co-expression of NsarsM and NsarsI conferred As(III) resistance at levels similar to that with NsarsM alone, although the main species found in solution after As(III) biotransformation was methylarsenate [MAs(V)] rather than DMAs(V). Co-expression of NsarsM and NsarsI conferred a higher level of resistance to MAs(III) than found with expression of NsarsM alone but lower than expression of only NsarsI. Cells co-expressing both genes converted MAs(III) to a mixture of As(III) and DMAs(V). In Nostoc NsarsM is constitutively expressed, while NsarsI is inducible by either As(III) or MAs(III). Thus, our results suggest that at low concentrations of arsenic, NsArsM activity predominates, while NsArsI activity predominates at high concentrations. We propose that coexistence of arsM and arsI genes in Nostoc could be advantageous for several reasons. First, it confers a broader spectrum of resistance to both As(III) and MAs(III). Second, at low concentrations of arsenic, the MAs(III) produced by NsArsM will possibly have antibiotic-like properties and give the organism a competitive advantage. Finally, these results shed light on the role of cyanobacteria in the arsenic biogeochemical cycle.

Potential application of digital image-processing method and fitted logistic model to the control of oriental fruit moths (Grapholita molesta Busck)

Monitoring of oriental fruit moths (Grapholita molesta Busck) is a prerequisite for its control. This study introduced a digital image-processing method and logistic model for the control of oriental fruit moths. First, five triangular sex pheromone traps were installed separately within each area of 667 m2 in a peach orchard to monitor oriental fruit moths consecutively for 3 years. Next, full view images of oriental fruit moths were collected via a digital camera and then subjected to graying, separation and morphological analysis for automatic counting using MATLAB software. Afterwards, the results of automatic counting were used for fitting a logistic model to forecast the control threshold and key control period. There was a high consistency between automatic counting and manual counting (0.99, P < 0.05). According to the logistic model, oriental fruit moths had four occurrence peaks during a year, with a time-lag of 15-18 days between adult occurrence peak and the larval damage peak. Additionally, the key control period was from 28 June to 3 July each year, when the wormy fruit rate reached up to 5% and the trapping volume was approximately 10.2 per day per trap. Additionally, the key control period for the overwintering generation was 25 April. This study provides an automatic counting method and fitted logistic model with a great potential for application to the control of oriental fruit moths.

Centipeda minima (Ebushicao) extract inhibits PI3K-Akt-mTOR signaling in nasopharyngeal carcinoma CNE-1 cells

Background

Centipeda minima (Ebushicao) has been used for the treatment of various diseases, such as nasal allergies, rhinitis and sinusitis, nasopharyngeal carcinoma, cough, and headache. This study aims to investigate the anticancer activities of Centipeda minima ethanol extracts (CME) against nasopharyngeal carcinoma cell CNE-1 and their underlying mechanism.

Methods

CNE-1 cells were treated with different concentrations (15–50 μg/mL) of CME for different time intervals (24, 48, and 72 h). Cytotoxicity of CME was determined by MTT assay. Cell morphological changes were observed by fluorescence microscopy after HO 33258 staining. Cell cycle status was evaluated by flow cytometry following propidium iodide staining. Apoptosis was detected by flow cytometry following annexin V-FITC/PI staining. The levels of apoptosis-associated and PI3K-Akt-mTOR signaling related proteins were measured by western blotting analysis.

Results

CME (15–50 μg/mL) significantly inhibited the proliferation of CNE-1 in a dose- and time-dependent manner (P = 0.026 for 15 μg/mL, P < 0.001 for 25, 30, 40, and 50 μg/mL, respectively); the IC₅₀ values (μg/mL) were 41.57 ± 0.17, 30.34 ± 0.06 and 24.98 ± 0.08 for 24, 48 and 72 h treatments, respectively. Significant morphological changes of CNE-1 cells displaying apoptosis were observed after CME treatment. CME showed low cytotoxicity toward normal LO2 cells. CNE-1 cells were arrested in the G2/M phase while treated with 15, 25, 40 μg/mL of CME, respectively (P = 0.032, P = 0.0053, P < 0.001). CME (15, 25, 40 μg/mL) down-regulated Bcl-2 expression (P = 0.032, P = 0.0074, P < 0.001), and up-regulated Bax (P = 0.026, P = 0.0056, P < 0.001) with activation of caspase-3, caspase-8, caspase-9, and PARP observed in CNE-1 cells (P = 0.015, P = 0.0067, P < 0.001 for caspase 3; P = 0.210, 0.028, < 0.001 for caspase 8; P = 0.152, 0.082, 0.0080 for caspase 9; P = 0.265, 0.0072, < 0.001 for PARP). CME suppressed the activation of the PI3K-AKT-mTOR pathway (P = 0.03, 0.0007, 0.004, 0.006, 0.022 for p-PI3K, p-Akt-Ser⁴⁷³, p-Akt-Thr³⁰⁸, p-mTOR-Ser²⁴⁴⁸, p-mTOR-Ser²⁴⁸¹, respectively after 40 μg/mL of CME treated for 24 h).

Conclusion

CME inhibited the proliferation of CNE-1 cells and activation of the PI3K-AKT-mTOR signaling pathway.

Development-related expression patterns of protein-coding and miRNA genes involved in porcine muscle growth

Muscle growth and development is associated with remarkable changes in protein-coding and microRNA (miRNA) gene expression. To determine the expression patterns of genes and miRNAs related to muscle growth and development, we measured the expression levels of 25 protein-coding and 16 miRNA genes in skeletal and cardiac muscles throughout 5 developmental stages by quantitative reverse transcription-polymerase chain reaction. The Short Time-Series Expression Miner (STEM) software clustering results showed that growth-related genes were downregulated at all developmental stages in both the psoas major and longissimus dorsi muscles, indicating their involvement in early developmental stages. Furthermore, genes related to muscle atrophy, such as forkhead box 1 and muscle ring finger, showed unregulated expression with increasing age, suggesting a decrease in protein synthesis during the later stages of skeletal muscle development. We found that development of the cardiac muscle was a complex process in which growth-related genes were highly expressed during embryonic development, but they did not show uniform postnatal expression patterns. Moreover, the expression level of miR-499, which enhances the expression of the β-myosin heavy chain, was significantly different in the psoas major and longissimus dorsi muscles, suggesting the involvement of miR-499 in the determination of skeletal muscle fiber types. We also performed correlation analyses of messenger RNA and miRNA expression. We found negative relationships between miR-486 and forkhead box 1, and miR-133a and serum response factor at all developmental stages, suggesting that forkhead box 1 and serum response factor are potential targets of miR-486 and miR-133a, respectively.

Evaluation of coarsely ground wheat as a replacement for ground corn in the diets of lactating dairy cows

Eight multiparous Holstein cows (569±47 kg of BW; 84±17 DIM) were used to evaluate the effects of different levels of coarsely ground wheat (CGW) as replacements for ground corn (GC) in diets on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites profiles in dairy cows. The cows were settled in a replicated 4×4 Latin square design with 3-wk treatment periods; four cows in one of the replicates were fitted with rumen cannulas. The four diets contained 0, 9.6, 19.2, and 28.8% CGW and 27.9, 19.2, 9.6, and 0% GC on dry matter (DM) basis, respectively. Increasing dietary levels of CGW, daily DM intake tended to increase quadratically (p = 0.07); however, apparent digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were significantly decreased (p<0.01) in cows fed the 28.8% CGW diets. Ruminal pH remained in the normal physiological range for all dietary treatments at all times, except for the 28.8% CGW diets at 6 h after feeding; moreover, increasing dietary levels of CGW, the daily mean ruminal pH decreased linearly (p = 0.01). Increasing the dietary levels of CGW resulted in a linear increase in ruminal propionate (p<0.01) and ammonia nitrogen (NH3-N) (p = 0.06) concentration, while ruminal acetate: propionate decreased linearly (p = 0.03) in cows fed the 28.8% CGW diets. Milk production was not affected by diets; however, percentage and yield of milk fat decreased linearly (p = 0.02) when the level of CGW was increased. With increasing levels of dietary CGW, concentrations of plasma beta-hydroxybutyric acid (BHBA) (p = 0.07) and cholesterol (p<0.01) decreased linearly, whereas plasma glucose (p = 0.08), insulin (p = 0.02) and urea nitrogen (p = 0.02) increased linearly at 6 h after the morning feeding. Our results indicate that CGW is a suitable substitute for GC in the diets of dairy cows and that it may be included up to a level of 19.2% of DM without adverse effects on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites if the cows are fed fiber-sufficient diets.

Protective Efficacy of Alpha-lipoic Acid against AflatoxinB1-induced Oxidative Damage in the Liver

Alpha-lipoic acid (α-LA) is not only involved in energy metabolism, but is also a powerful antioxidant that can protect against hepatic oxidative stress induced by some drugs, toxins, or under various physiological and pathophysiological conditions. Here, we investigated the effect of α-LA against liver oxidative damage in broilers exposed to aflatoxin B₁ (AFB₁). Birds were randomly divided into four groups and assigned different diets: basal diet, 300 mg/kg α-LA supplementation in basal diet, diet containing 74 μg/kg AFB₁, and 300 mg/kg α-LA supplementation in diet containing 74 μg/kg AFB₁, for 3 weeks. The results revealed that the addition of 300 mg/kg α-LA protected against the liver function damage of broilers induced by chronic low dose of AFB₁ as estimated by a significant (p<0.05) change in levels of plasma total protein, albumin, alkaline phosphatase and the activities of liver glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase. The histopathological analysis also showed that liver tissues were injured in the AFB₁ diet, but this effect was alleviated by the addition of 300 mg/kg α-LA. Additionally, AFB₁ induced a profound elevation of oxidative stress in birds, as indicated by an increase in malondialdehyde level, a decrease in glutathione peroxidase activity and a depletion of the glutathione content in the liver. All of these negative effects were inhibited by treatment with α-LA. Our results suggest that the inhibition of AFB₁-induced excess production of lipid peroxides and the maintenance of intracellular antioxidant status may play important roles in the protective effects of α-LA against AFB₁-induced oxidative damage in the liver.

[Distribution of compact bone mesenchymal stem cells in lung tissue and bone marrow of mouse]

This study was aimed to investigate the distribution of compact bone mesenchymal stem cells(MSC) marked with lentiviral plasmid pGC FU-RFP-LV in lung tissue and bone marrow of mouse. The MSC were infected by lentivirus with infection efficiency 78%, the infected MSC were injected into BALB/c mice via tail veins in concentration of 1×10(6) /mouse. The mice were randomly divided into 4 group according to 4 time points as 1, 2, 5 and 7 days. The lung tissue and bone marrow were taken and made of frozen sections and smears respectively in order to observed the distributions of MSC. The results indicated that the lentiviral infected MSC displayed phenotypes and biological characteristics which conformed to MSC by immunophenotyping analysis and induction differentiation detection. After the MSC were infected with optimal viral titer MOI = 50, the cell growth no significantly changed; the fluorescent microscopy revealed that the distributions of MSC in bone marrow on day 1, 2, 5 and 7 were 0.50 ± 0.20, 0.67 ± 0.23, 0.53 ± 0.14, 0.33 ± 0.16; those in lung tissue were 0.55 ± 0.15, 0.47 ± 0.13, 0.29 ± 0.13, 0.26 ± 0.08. It is concluded that the distribution of MSC in lung tissue reaches a peak on day 1, while distribution of MSC in bone marrow reaches a peak on day 2. The distribution of mouse MSC relates with RFP gene expression and implantation of MSC in lung tissue and bone marrow.

Ethanolic extract of rhizome of Ligusticum chuanxiong Hort. (chuanxiong) enhances endothelium-dependent vascular reactivity in ovariectomized rats fed with high-fat diet

Rhizome of Ligusticum chuanxiong Hort. (LC), also known as chuanxiong, is a very common herb widely used to treat cardiovascular and cerebrovascular diseases.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

Origin of strong white electroluminescence from dense Si nanodots embedded in silicon nitride

Strong white electroluminescence (EL) from SiN-based devices containing Si nanodots with a density of more than 4.6×10(12)cm(2) was investigated. The white EL illustrates enhanced light emission with increasing applied voltage and can be divided into two components, a dominant peak at ~710 nm and weak one at ~550 nm, which are close to those of the PL spectra optically pumped by the 325 and 488 nm lines, respectively. Based on the PL characteristics, we propose that the dominant EL band arises from the band-to-band recombination in the dense Si nanodots where quantum confinement plays a decisive role in the light emission, whereas the weak EL band originates from the radiative Si dangling bond (K⁰) centers in the silicon nitride matrix.

[Research progress on immunologic mechanisms of mesenchymal stem cells for treatment of graft-versus-host disease]

Mesenchymal stem cells (MSC) are the non-hematopoietic stem cells with a multi-differentiation potentials, which has a low immunogenicity and immune regulation ability. MSC immune regulation ability is particularly important, such as MSC can inhibit the activation and proliferation of T, B lymphocytes, NK cells and dendritic cells (DC). Meanwhile, MSC is able to reconstruct the human hematopoietic microenvironment, improving the successful rate of hematopoietic stem cell transplantation. Graft versus host disease (GVHD) is the main factor causing hematopoietic stem cell transplantation-related mortality. Based on the above mentioned properties, MSCs are used to treat autoimmune diseases and GVHD, recently. Therefore, deep exploration of the cellular immune mechanisms of MSC to treat GVHD is particularly important. This review focuses on progress of research related to treatment of GVHD by MSC immune mechanisms and briefly summarizes the status of the clinical studies.

Enhanced electroluminescence from SiN-based multilayer structure by laser crystallization of ultrathin amorphous Si-rich SiN layers

Luminescent SiN-based multilayers were prepared in a plasma enhanced chemical vapor deposition system followed by subsequently laser crystallization of ultrathin amorphous Si-rich SiN sublayers. The cross-sectional TEM analysis reveals that grain size of Si nanocrystals embedded in the Si-rich SiN sublayers is independent of the laser fluence, while the grain density can be well controlled by the laser fluence. The devices containing the laser crystallized multilayers show a low turn-on voltage of 5 V and exhibit strong green light emission under both optical and electrical excitations. Moreover, the device after laser-irradiated at 554 mJ/cm(2) shows a significantly enhanced EL intensity as well as external quantum efficiency compared with the device without laser irradiation. The EL mechanism is suggested from the bipolar recombination of electron-hole pairs at Si nanocrystals. The improved performance of the devices was discussed.

Superconductivity in iron telluride thin films under tensile stress

By realizing in thin films a tensile stress state, superconductivity of 13 K was introduced into FeTe, a nonsuperconducting parent compound of the iron pnictides and chalcogenides, with a transition temperature higher than that of its superconducting isostructural counterpart FeSe. For these tensile stressed films, superconductivity is accompanied by a softening of the first-order magnetic and structural phase transition, and also, the in-plane extension and out-of-plane contraction are universal in all FeTe films independent of the sign of the lattice mismatch, either positive or negative. Moreover, the correlations were found to exist between the transition temperatures and the tetrahedra bond angles in these thin films.

Effect of tea saponin on methanogenesis, microbial community structure and expression of mcrA gene, in cultures of rumen micro-organisms

AIMS

To determine the in-vitro effect and mode of action of tea saponin on the rumen microbial community and methane production.

METHODS AND RESULTS

Saponin extracted from tea seeds was added to (1) an in-vitro fermentation inoculated with rumen fluid and (2) a pure culture of Methanobrevibacter ruminantium. Methane production and expression of the methyl coenzyme-M reductase subunit A (mcrA) were monitored in both cultures. Abundance of methanogens, protozoa, rumen fungi and cellulolytic bacteria were quantified using real-time PCR, and bacterial diversity was observed using denaturing gradient gel electrophoresis. Addition of tea saponin significantly reduced methane production and mcrA gene expression in the ruminal fermentation but not with the pure culture of M. ruminantium. The abundance of protozoa and fungi were significantly decreased 50% and 79% respectively but methanogen numbers were not affected, and Fibrobacter succinogenes increased by 41%. Bacterial diversity was similar in cultures with or without tea saponin.

CONCLUSIONS

Tea saponin appeared to reduce methane production by inhibiting protozoa and presumably lowering methanogenic activity of protozoal-associated methanogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Tea saponin may be useful as a supplement to indirectly inhibit methane production in ruminants without a deleterious effect on rumen function.

Frequency spectra of beam-plates revisited

Based on Mindlin's plate theory, the frequency spectra for flexural and thickness-shear vibrations of a finite beam-plate with different combinations of boundary conditions are presented and studied. Comparing them with the dispersion curves of the infinite beam-plate reveals an intrinsic relation between resonant vibration and guided wave propagation. The fundamental frequency spectra, which are for beam-plates with hinged and/or guided edges, are found to play an important role in understanding the spectra of beam-plates with other boundary conditions.

Using molecular markers to identify two major loci controlling carotenoid contents in maize grain

Maize is an important source of pro-vitamin A; beta-carotene, alpha-carotene and beta-cryptoxanthin, and the non-pro-vitamin A carotenoids including lutein and zeaxanthin. In the present study, a recombinant inbred (RI) population with 233 RI lines derived from a cross between By804 and B73 was employed to detect QTL for these nutritionally important components in maize grain. High Performance Liquid Chromatography was used to measure amounts of individual carotenoids over 2 years. A genetic linkage map was constructed with 201 molecular markers. In all, 31 putative QTL including 23 for individual and 8 for total carotenoids were detected on chromosome(s) 1, 3, 5, 6, 7, 8 and 10. The notable aspect of this study was that much of the phenotypic variation in contents of carotenoids could be explained by two loci (y1 and y9), and the QTL for carotenoids elucidated the interrelationships among these compounds at the molecular level. A gene targeted marker (Y1ssr) in the candidate gene phytoene synthase 1 (psy1) tightly linked to a major QTL explaining 6.6-27.2% phenotypic variation for levels of carotenoids was identified, which may prove useful to expedite breeding for higher level of carotenoids in maize grain. This functionally characterized gene (psy1) could also be exploited for further development of functional marker for carotenoids in maize. The QTL cluster located at y9 locus may also be used for pyramiding favorable alleles controlling contents of carotenoids from diverse maize germplasm.

Sustained elevation of Epstein-Barr virus antibody levels preceding clinical onset of nasopharyngeal carcinoma

We have monitored Epstein–Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37±28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.

Measurements of the continuum R(uds) and R values in e(+)e(-) annihilation in the energy region between 3.650 and 3.872 GeV

We report measurements of the continuum R(uds) near the center-of-mass energy of 3.70 GeV, the R[uds(c)+psi(3770)](s) and the R(had)(s) values in e(+)e(-) annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collider. We obtain the R(uds) for the continuum light hadron (containing u, d, and s quarks) production near the DD threshold to be R(uds)=2.141+/-0.025+/-0.085.