Search

Observation of high energy and very high emission from Gamma Ray Bursts (GRBs) is crucial to study the gigantic explosion and the underline processes. With a large field-of-view and almost full duty cycle, the Water Cherenkov Detector Array (WCDA), a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs. Nevertheless, the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector. To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation. The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV. The sensitivity of the WCDA for GRB detection with the new trigger method is estimated. The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT. The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.

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 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.

BackgroundEngaging patients and families as research partners increases the relevance, quality, and impact of child health research. However, those interested in research engagement may feel underequipped to meaningfully partner. We sought to co-develop an online learning (e-learning) module, “Research 101,” to support capacity-development in patient-oriented child health research amongst patients and families.MethodsModule co-development was co-led by a parent and researcher, with guidance from a diverse, multi-stakeholder steering committee. A mixed-methods usability testing approach, with three iterative cycles of semi-structured interviews, observations, and questionnaires, was used to refine and evaluate the e-learning module. Module feedback was collected during testing and a post-module interview, and with the validated System Usability Scale (SUS), and satisfaction, knowledge, and self-efficacy questionnaires. Transcripts and field notes were analyzed through team discussion and thematic coding to inform module revisions.ResultsThirty participants fully tested Research 101, and another 15 completed confirmatory usability testing (32 caregivers, 6 patients, and 7 clinician-researchers). Module modifications pertaining to learner-centered design, content, aesthetic design, and learner experience were made in each cycle. SUS scores indicated the overall usability of the final version was “excellent.” Participants' knowledge of patient-oriented research and self-efficacy to engage in research improved significantly after completing Research 101 (p < 0.01).ConclusionsCo-development and usability testing facilitated the creation of an engaging and effective resource to support the scaling up of patient-oriented child health research capacity. The methods and findings of this study may help guide the integration of co-development and usability testing in creating similar resources.

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 plane3–6, 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. Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.

We report the discovery of a new unidentified extended $\gamma$-ray source in the Galactic plane named LHAASO J0341+5258 with a pre-trial significance of 8.2 standard deviations above 25 TeV. The best fit position is R.A.$=55.34^{\circ}\pm0.11^{\circ}$ and Dec$=52.97^{\circ}\pm0.07^{\circ}$. The angular size of LHAASO J0341+5258 is $0.29^\circ \pm 0.06^\circ_{stat} \pm0.02^\circ_{sys}$. The flux above 25 TeV is about $20\%$ of the flux of Crab Nebula. Although a power-law fit of the spectrum from 10 TeV to 200 TeV with the photon index $\alpha=2.98 \pm 0.19_{stat} \pm 0.02_{sys}$ is not excluded, the LHAASO data together with the flux upper limit at 10 GeV set by the Fermi LAT observation, indicate a noticeable steepening of an initially hard power-law spectrum %($\alpha \leq 1.75$) spectrum with a cutoff at $\approx 50$ TeV. We briefly discuss the origin of UHE gamma-rays. The lack of an energetic pulsar and a young SNR inside or in the vicinity of LHAASO J0341+5258 challenge, but do not exclude both the leptonic and hadronic scenarios of gamma-ray production., Comment: Accepted by APJL

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 is10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

We present a spatially resolved H ii region study of the gas-phase metallicity, ionization parameter, and interstellar medium (ISM) pressure maps of six local star-forming and face-on spiral galaxies from the TYPHOON program. Self-consistent metallicity, ionization parameter, and pressure maps are calculated simultaneously through an iterative process to provide useful measures of the local chemical abundance and its relation to localized ISM properties. We constrain the presence of azimuthal variations in metallicity by measuring the residual metallicity offset Δ(O/H) after subtracting the linear fits to the radial metallicity profiles. We, however, find weak evidence of azimuthal variations in most of the galaxies, with small (mean 0.03 dex) scatter. The galaxies instead reveal that H ii regions with enhanced and reduced abundances are found distributed throughout the disk. While the spiral pattern plays a role in organizing the ISM, it alone does not establish the relatively uniform azimuthal variations we observe. Differences in the metal abundances are more likely driven by the strong correlations with the local physical conditions. We find a strong and positive correlation between the ionization parameter and the local abundances as measured by the relative metallicity offset Δ(O/H), indicating a tight relationship between local physical conditions and their localized enrichment of the ISM. Additionally, we demonstrate the impact of unresolved observations on the measured ISM properties by rebinning the data cubes to simulate low-resolution (1 kpc) observations, typical of large IFU surveys. We find that the ionization parameter and ISM pressure diagnostics are impacted by the loss of resolution such that their measured values are larger relative to the measured values on sub-H ii region scales.

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 E25 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.

We report the discovery of a UHE gamma-ray source, LHAASO J2108+5157, by analyzing the LHAASO-KM2A data of 308.33 live days. Significant excess of gamma-ray induced showers is observed in both energy bands of 25-100 TeV and $\gt$100 TeV with 9.5 sigma and 8.5 sigma, respectively. This source is not significantly favored as an extensive source with the angular extension smaller than the point-spread function of KM2A. The measured energy spectrum from 20 to 200 TeV can be approximately described by a power-law function with an index of -2.83$\pm$ 0.18stat. A harder spectrum is demanded at lower energies considering the flux upper limit set by Fermi-LAT observations. The position of the gamma-ray emission is correlated with a giant molecular cloud, which favors a hadronic origin. No obvious counterparts have been found, deeper multiwavelength observations will help to shed new light on this intriguing UHE source., Comment: 12 pages, 7 figures, accepted by ApJL

The main scientific goal of the LHAASO WFCTA experiment is to measure the cosmic ray energy spectra and composition from 10 TeV to 1 EeV. Cherenkov photons in the extensive air shower measured by the SiPM camera of Cherenkov telescopes can be used to reconstruct the cosmic ray energy. The absolute calibration of the camera is a crucial step to achieve the accurate measurement of the cosmic ray energy spectrum. A multi-wavelength cylindrical illuminator based on LEDs is developed and mounted inside the telescope to calibrate and monitor the camera, and the illuminator’s stability is better than 0.5% under the temperature variation from -26 to 26 ° C. A portable probe with a single photoelectron resolution of 21.6% is developed. After calibration by National Institute of Metrology, China (NIM), the probe is taken to the LHAASO site to measure the absolute photon density of the cylindrical illuminator inside the telescope. Based on the illuminator with known photon density, the photon conversion factor of the camera can be calibrated, and the overall calibration uncertainty is less than 2.6%.

The Water Cherenkov Detector Array (WCDA) is a major component of the Large High Altitude Air Shower Array Observatory (LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. The WCDA is aimed at the study of TeV $\gamma$-rays. In order to evaluate the prospects of searching for TeV $\gamma$-ray sources with the WCDA, we present in this paper a projection for the one-year sensitivity of the WCDA to TeV $\gamma$-ray sources from TeVCat (footnote: http://tevcat.uchicago.edu) using an all-sky approach. Out of 128 TeVCat sources observable to the WCDA up to a zenith angle of $45^\circ$, we estimate that 42 would be detectable for one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei (AGN)., Comment: 10 pages,10 figures, it is to be published in Chinese Physics C

Cervical cancer seriously threatens women’s health, it seriously harm the patient’s physical and mental health. The new derivative of Acanthus ilicifolius Linn alkaloid 2-benzoxazone was obtained from o-aminophenol, substituted benzaldehyde, trichloroacetic acid and isocyanate via a tandem Ugi 4CC/SN cyclization (N-cyclohexyl-2-(2-benzoxazolone-3-yl)-2-p-trifluoromethylphenylacetamide, BOABB), and the toxicity of the new compound to the cervical cancer C-33A cells was detected by CCK-8 assay, wound healing assay and apoptotic assay. The results exhibited that BOABB had obvious inhibitory effect on C-33A cells, and the calculated IC50 was 32.3 μM. Wound healing assay showed that BOABB could significantly inhibit cell migration (P

The LHAASO-WFCTA experiment, which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique, uses a new generation of high-performance telescopes. To ensure that the experiment has excellent detection capability associated with the measurement of the energy spectrum, the primary composition of cosmic rays, and so on, an accurate geometrical reconstruction of air-shower events is fundamental. This paper describes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA (Wide Field of view Cherenkov/Fluorescence Telescope Array) detectors. Two approaches, which take full advantage of the WFCTA detectors, are investigated. One is the stereo-angular method, which uses the pointing of triggered SiPMs in the shower trajectory, and the other is the stereo-timing method, which uses the triggering time of the fired SiPMs. The results show that both methods have good geometrical resolution; the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.

The isopentytransperase (IPT) gene, coupled to the SAG12 promoter, was successfully transferred into the eggplant (Solanum melongena L.) mediated by Agrobacterium tumefaciens. Four PSAG12 IPT overexpressing transgenic plants were identified by Southern blotting. Reverse transcription polymerase chain reaction revealed that IPT was expressed in senescent leaves under the control of SAG12 promoter. Compared with wild type eggplants, the leaf senescence was significantly delayed and tolerance to drought and cold stress was enhanced in the T1 generation of PSAG12-IPT transgenic eggplants. The contents of chlorophyll, indoleacetic acid, zeatin riboside, and gibberellic acid in the transgenic eggplants were higher than those in the wild type eggplants. The activities of reactive oxygen species-scavenging enzymes in the transgenic eggplants were also higher than those in the wild type eggplants. Abscisic acid and malondialdehyde levels were lower in the transgenic plants than in the wild type plants. Als...

Wide Field view of Cherenkov Telescope Array(WFCTA of LHAASO,consisting of 18 telesopes, has been proposed to mount at Daocheng County, Sichuan Province, China, to probe the galactic cosmic rays with the energies from 3×1013eV-1017eV together with WCDA and KM2A of LHAASO.2 N2 laser systemsand 2YAG lasersystems will bebuilt to calibrate the detection effeciency of WFCTA and monitoring atmosphere. The laser beam in N2 laser systems, originally the rectangle facula with 3mmtimes7mm, are bound the circular facula with the radius not more than 10mm at the 20cm to the N2 laser head. The N2 laser systems are relatively simple to run normally in our testing, at LHAASO base and the campus of Southwest Jiaotong University. To keep a relatively constant temperature condition,an auto-heating belt is fixed outside of the YAG laser head. In this paper the performance of the 4 laser systems will be reported in detail.

Superconductivity in monolayer transition metal dichalcogenides is characterized by Ising-type pairing induced via a strong Zeeman-type spin-orbit coupling. When two transition metal dichalcogenides layers are coupled, more exotic superconducting phases emerge, which depend on the ratio of Ising-type protection and interlayer coupling strength. Here, we induce superconductivity in suspended MoS

The detection of almost 100% linearly polarized emission from the fast radio burst source FRB 121102 implies coherent emission of relativistic electrons moving perpendicular to the ambient magnetic field. The origin of such a particle distribution is very intriguing. Given that FRB 121102 is likely driven by a neutron star, we explored orbits of charged particles trapped in a dipole magnetic field (the Störmer problem). Most previous studies focused on particles with relatively low energies so that the guiding center approximation may be applied. High-energy particles usually have chaotic orbits except those on a periodic orbit or near stable periodic orbits. Via evaluation of the maximum Lyapunov exponent of orbits of particles launched from the equatorial plane with an axial velocity (the angular velocity sets the length and energy scales of the system), we found prominent regions of quasi-periodic orbits around stable periodic orbits in the equatorial plane at high energies. Particles in these orbits oscillate around the equatorial plane and their radial distance from the dipole can vary by a factor of ∼2. Relativistic electrons in such orbits may be responsible for the almost 100% polarized emission from FRB 121102.

A sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV. Even though the detector construction is still underway, half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the KM2A data analysis pipeline and the first observation of the Crab Nebula, a standard candle in very high energy γ-ray astronomy. We detect γ-ray signals from the Crab Nebula in both energy ranges of 10 100 TeV and 100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance, including angular resolution, pointing accuracy and cosmic-ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE = (1.13 0.05 0.08 ) 10 (E/20 TeV) cm s TeV . It is consistent with previous measurements by other experiments. This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena, such as cosmic PeVatrons, might be discovered.

Reservoirs play a significant role in changing the natural hydrological conditions. This paper studies the change characteristics of runoff fluctuation caused by the Gangkouwan Reservoir in Shuiyangjiang River, and collects the hourly flow data from two hydrological stations upstream and downstream of the reservoir. Through the comparison of the uneven coefficient (CV ) and concentration degree (Cd ) of the two stations, reflect the impact of the reservoir on runoff changes at two-time scales of intra-annual and intra-month. The results shown the Gangkouwan Station has significant changes in runoff distribution at intra-annual and intra-month scales, affected by the reservoir. For the intra-month runoff, the runoff process at Gangkouwan Station is more uniform than Hulesi station in the flood season, because the reservoir has to store water. In the dry season, the opposite is realized, because the reservoir needs to discharge water to generate electricity. This paper is more conducive to deepening the understanding of the impact of reservoir operations on hydrological processes.

We evaluated the effect of continuous perfusion of esmolol on cardiovascular risk during curative laparoscopic surgery for gastrointestinal cancer in elderly patients. Sixty patients with gastrointestinal cancer, aged from 60 to 80 years, were divided into an esmolol group (ES, n = 30) and a control group (NS, n = 30). ES patients were treated with esmolol at a dose of 0.3 mg/kg 3 min before tracheal intubation, and received continuous perfusion of esmolol at a dose of 50 μg/kg/min during operation. In NS, esmolol was replaced by saline. SBP/DBP, MAP, HR, SPO2, PETCO2, the depth of anesthesia and the value of RPP were recorded before anesthesia (T0), during intubation (T1), 10 min before pneumoperitoneum (T2), during pneumoperitoneum (T3), 30 min after incision (T4), at the end of surgery (T5), during extubation (T6) and 30 min after extubation (T7). The serum levels of cTnI, CK, CK-MB and LDH were measured before anesthesia, 6 and 30 h after surgery. HR, MAP, RPP at T1, T3, T6 in ES were obviously decreased compared with NS (P0.05). There were no significant differences between both groups at different time points with respects to the serum levels of cTnI, CK, CK-MB and LDH. No major adverse cardiocerebral event was observed in both groups in three postoperative months. The present study indicated that the application of esmolol during curative laparoscopic surgery for gastrointestinal cancer can effectively reduce the cardiovascular responses in intubation, operation and extubation, sustain hemodynamic stable, reduce myocardial oxygen consumption, and prevent perioperative adverse cardiovascular events, but had no significant myocardial protective effect.

The cardanol grafted onto polypropylene (CAPP) was prepared by reactive extrusion with polypropylene (PP) and natural renewable cardanol, which could improve the inherent defects of PP such as chemical inertness and hydrophobicity. Moreover, the cardanol grafted onto PP could resolve the degradation of PP during the process of reactive extrusion, storage and application. In this paper, the yield strength, tensile strength, elongation at break of modified and unmodified PPs were tested during the aging process. A possible aging mechanim of PP and anti-aging mechanism of cardanol grafted onto PP were proposed. Results showed that the initiator dicumyl peroxide caused the degradation of PP chains during the aging processing. After being aged for 24 h, the yield strength CAPP0 decreased from 28 MPa to 15 MPa and the elongation at break reduced by 795%. CAPPs possessed outstanding anti-aging performance owing to the cross-linking and entanglement of the side chains of cardanol grafted onto PP. The yield strength, tensile strength and the elongation at break of CAPP5 changed lightly even when it was in long-term irradiation for 480 h. The CAPPs had better anti-aging properties than the mixture of PP and 5% of cardanol. CAPP containing 3% of cardanol could effectively prevent the degradation of the main chain polypropylene.

By dual gating a few-layer MoS_{2} flake, we induce spatially separated electronic states showing superconductivity and Shubnikov-de Haas (SdH) oscillations. While the highly confined superconductivity forms at the K/K^{'} valleys of the topmost layer, the SdH oscillations are contributed by the electrons residing in the Q/Q^{'} valleys of the rest of the bottom layers, which is confirmed by the extracted Landau level degeneracy of 3, electron effective mass of 0.6m_{e}, and carrier density of 5×10^{12} cm^{-2}. Mimicking conventional heterostructures, the interaction between the heteroelectronic states can be electrically manipulated, which enables "bipolarlike" superconducting transistor operation. The off-on-off switching pattern can be continuously accessed at low temperatures by a field effect depletion of carriers with a negative back gate bias and the proximity effect between the top superconducting layer and the bottom metallic layers that quenches the superconductivity at a positive back gate bias.

Patients with severe burn are characterized by strong oxidative stress and intense inflammatory response, which will cause metabolic disorder. Therefore, nutrition therapy is very important for severe burn. Nutrition therapy includes enteral nutrition (EN) and parenteral nutrition, and EN has the unique advantages. In recent years, more and more researchers focused on the EN for severe burn injuries, but there were still some confusing problems needing to solve. This article reviews the recent research about nutrition therapy for severe burn, including the route of feeding, energy requirements, and supplements of protein, carbohydrates, and microelements, and so on, so as to clarify some confusing questions about nutrition therapy for severe burn in clinical practice.

We investigate the extinction coefficients of the surface atmospheric aerosol over the Large High Altitude Air Shower Observatory (LHAASO), located at the Haizi Mountain, Daocheng County, China. To this end, we utilize the Longtin model, Mie scattering theory, and experimental data obtained by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). Our theoretical calculations show that the total extinction coefficients of the atmospheric aerosol at the wavelength of 200–500 nm are inversely proportional to the laser wavelength, and influenced by the wind speed. From July 2015 to October 2016, the extinction coefficient of the surface atmospheric aerosols at 532 nm wavelength reached 0.04 km−1 with no wind, while it increased to 0.1 km−1 with gusts. In this period, the extinction coefficients of the surface atmospheric aerosol at 532 nm wavelength, obtained by the CALIPSO, change from 0.01 to 0.07 km−1, which is less than the values obtained the theoretical calculation and larger than the average of Tibetan Plateau in 2006−2016. These calculations and experimental evidence provide important arguments to the model of atmospheric aerosol to be applied in the calibration of LHAASO. Our results suggest that the extinction coefficients over LHAASO require further study, including research on the size distribution, shape, concentration of aerosols particles, wind dependence, relative humidity dependence, etc.

Automated identification and characterization of clustered weld defects, which comprise a plural of closely distributed individual member defects, is challenging. In this paper, time, Cartesian and Polar domain features in phased array ultrasonic sectorial scanning data are studied to segment clustered weld defect echoes by density based and K-means clustering. Through multiple domain segmentation, all individual member defect echoes are successfully identified. Then size and depth estimation is performed on each individual member defect to describe its patterns and to locate its depth. The developed technique is applied to experimental data collected from scanning on a tubular T weld test sample and is shown to discriminate, locate, and measure all the individual defects inside clustered defects. Based on the geometrical features of each individual member defect, they are classified as either point, linear or planar defects.

While inspecting on tubular TKY joints, ultrasound travels into the weld cross section from an elliptical surface whose profile changes along the weld seam. The complex geometries of the scanning profile cause two challenging issues for ultrasound inspection: existence of dead zones and localization of a defect. This paper derives the parametric formulations to systematically model the weld cross section profiles. With the established models, the profiles are constructed to visualize ultrasound beam simulation in order to maximize weld coverage. Simulation on typical positions along a Y joint is conducted using 5MHz, 16 and 64-elements phased array transducers. Transducer placement has been simulated and adjusted to determine scanning strategies. 98∼100% of the weld can be covered mainly from the branch pipe side, while at some locations supplemented scanning from the main pipe side is necessary. Sectorial scanning data on a real Y weld is analyzed and then overlaid with the built weld cross section profile enabling intuitive defect localization. Defects are identified at two different locations and their depth and height is also estimated.

The aim of this study was to investigate the efficacy of lumbar cistern drainage combined with intrathecal injection of antibiotics (LCD-ITI) in treating postoperative intracranial infections of hypertensive intracerebral hemorrhage (pHIH-ICI).Sixty pHIH-ICI patients were randomly divided into the control group and the treatment group, with 30 patients in each group. Conventional treatment was performed in the control group, while LCD-ITI was performed in the treatment group. The clinical outcomes, Glasgow Outcome Score (GOS), activities of daily living (ADL) scores, incidence rates of hydrocephalus and other indicators were compared.The improvement time of clinical symptoms, infection control time and hydrocephalus incidence of the treatment group were significantly lower than the control group (P0.05). Also the infection control rate, GOS score and ADL score of the treatment group were significantly higher or better than the control group (P0.05).LCD-ITI could improve clinical treatment and prognosis of pHIH-ICI patients.

We analyzed host-species specificity of Magnaporthe grisea on rice using 110 F1progeny derived from a cross between the Oryza isolate CH87 (pathogenic to rice) and the Digitaria isolate 6023 (pathogenic to crabgrass). To elucidate the genetic mechanisms controlling species specificity in M. grisea, we performed a genetic analysis of species-specific avirulence on this rice population. Avirulent and virulent progeny segregated in a 1:1 ratio on the 2 rice cultivars 'Lijiangxintuanheigu' (LTH) and 'Shin2', suggesting that a single locus, designated PRE1, was involved in the specificity. In a combination between 'Kusabue' and 'Tsuyuake', the segregation of the 4 possible phenotypes of F1progeny was significantly different from the expected 3:1:3:1 and instead fit a ratio of 2:0:1:1. This indicated that 2 loci, PRE1 and AVR2, were involved in specific parasitism on rice. These results suggest that the species specificity of M. grisea on rice is governed by species-dependent genetic mechanisms that are similar to the gene-for-gene interactions controlling cultivar specificity. Pathogenicity tests with various plant species revealed that the Digitaria isolate 6023 was exclusively parasitic on crabgrass. Genetic linkage analysis showed that PRE1 was mapped on chromosome 3 with respect to RAPD and SSR markers. RAPD marker S361 was linked to the avirulence gene at a distance of ~6.4 cM. Two SSR markers, m677–678 and m77–78, were linked to the PRE1 gene on M. grisea chromosome 3 at distances of 5.9 and 7.1 cM, respectively. Our results will facilitate positional cloning and functional studies of this gene.Key words: genetic analysis, graminaceous plants, Magnaporthe grisea, species-specific avirulence gene.

We determined DNA fingerprint haplotypes and pathotypes of the rice-blast fungus Magnaporthe grisea collected from 13 areas in China. This DNA fingerprinting analysis, using rep-PCR, of 381 haplotypes (482 isolates) from China indicated that the M. grisea populations cannot be delineated into region-specific groups. Analyses of the number of alleles (na), Nei's gene diversity, unbiased genetic distance, and Shannon's Information index among 13 populations showed that clusters were not related to the geographic distance between populations with the exception of the Ningxia (NX) and Jilin (JL) cluster. Among northern populations, NX and JL were more similar to one another than to other populations. Pathogen populations consisting of 121 isolates from China were grouped into 53 pathotypes on the basis of disease reaction in differential rice lines. Isolates assayed for pathotypes were detected based on disease reactions. No correlation was observed between fingerprint groups and pathotypes of the pathogen. High frequency of virulence was found on the rice line Shin2 (Pi-k s and Pi-sh) followed by PiNo.4 (Pi-ta 2 and Pi-sh) and Kl (Pi-ta), while it was low on Kanto 51 (Pi-k +?), K3 (Pi-k h ), and Fujisaka (Pi-i and Pi-sh). Virulence was rare on Toride 1 (Pi-z t and Pi-sh). Tetep (Pi-k h +?) was predicted to be a highly effective, as none of the isolates infected this line. These blast-resistant rice lines can be used in resistance breeding for the effective management of rice blast in the respective regions of China.

The China Dark matter Experiment collaboration reports the first experimental limit on WIMP dark matter from 14.6 kg-day of data taken with a 994 g p-type point-contact germanium detector at the China Jinping underground Laboratory where the rock overburden is more than 2400 m. The energy threshold achieved was 400 eVee. According to the 14.6 kg-day live data, we placed the limit of N= 1.75 * 10^{-40} cm^{2} at 90% confidence level on the spin-independent cross-section at WIMP mass of 7 GeV before differentiating bulk signals from the surface backgrounds., Comment: 5 pages, 5 figures

Studying the series Ca 1-x Na x LaBaCu 3 O y one finds that the tetragonal Na-doped CLBCO system exhibits superconducting properties when the oxygen content is below 6.6. X-ray diffraction analysis shows that Na has a limited solubility in the parent compound. It is concluded that the substitution of Na at (1/2, 1/2, 1/2) site reconstructs the long-range ordered Cu-O chains in the CuO planes. This introduces self-doping of holes on the CuO 2 planes, resulting in superconductivity at low oxygen content. But when the oxygen content increases up to y =6.85, the superconductivity can be explained in terms of the nominal hole concentration. The Na doping also decreases the processing temperature of CLBCO.

To examine the hypothesis that the pathway of adaptation to high altitude in natives differs considerably from that in newcomers, we measured maximal O2 uptake (VO2max), minute ventilation, anaerobic threshold (AT), blood lactate, and blood gases during maximal exercise in 17 lifelong Tibetan residents and 14 acclimatized Han Chinese newcomers living at the altitude of 4,700 m. The two groups were similar in age, height, and weight, and the subjects were nonathletes. Although VO2max was significantly lower in the Tibetans than in the Hans (30.4 +/- 1.5 vs. 36.0 +/- 1.9 ml.min-1.kg-1 STPD; P < 0.05), at maximal exercise effort the exercise workload was greater (167.7 +/- 4.2 vs. 150.0 +/- 5.9 W; P < 0.05). The mean AT values (in % VO2max) in the Tibetan and Han subjects were 84.1 and 61.6%, respectively (P < 0.01). Minute ventilation at maximal exercise was significantly lower in the Tibetans than in the Hans (68.4 +/- 3.4 vs. 79.7 +/- 4.1 l/min BTPS; P < 0.05), whereas heart rate at maximal effort was equivalent in the two groups. The Tibetans showed lower blood lactate value than did the Hans both before and at the end of exercise. We conclude that the Tibetan natives have higher exercise performance and AT but lower VO2max and blood lactate concentration than do acclimatized Han newcomers. These results may reflect the effects of genetic or peripheral adaptation factors in the Tibetan natives.

To investigate the possible mechanisms of adaptation to chronic hypoxia in the pulmonary circulation.We made direct measurements of pulmonary arterial pressure (Ppa) in 10 awake pika rodents that were transported to 2 260 m after being captured at 4 300 m and in 10 Wistar rats in a decompression chamber (simulated altitudes of 4 300 and 5 000 m) Ppa was obtained at 1 h of exposure to each simulated altitude.Ppa in the pikas after the 4 300 m and 5 000 m altitude exposed did not significantly increase whereas in the rats Ppa rose significantly. The ratio of right ventricular to left ventricular plus septal weight in the pikas and rats was 0.22 and 0.45 respectively. The pikas maintained levels of Hb, hematocrit and 2.3-diphosphoglycerate lower than those of the rats. The percent wall thickness of the small pulmonary arteries in the pikas and rats was 9.22 and 27.21%, respectively, and it was well correlated with the degree of Ppa in both groups. Mast cells were observed in the lung of the rats (7.1 +/- 0.33 cells/mm2) but not in the pikas, There was highly positive staining for mast cell tryptase around pulmonary vessels in the rats, whereas no demonstrable reaction was observed in the pikas.The pika has adapted to high altitude by losing hypoxia pulmonary vasoconstriction and thin-walled pulmonary arterioles. In rats, mast cells may play an important role in the remodeling of pulmonary vessels by activating some growth factors.

Betulinic acid has attracted attention in terms of its important biological and pharmacological characteristics. The main objective of this work was to optimize the variables of biotransformation process in order to enhance betulinic acid production from betulin catalysed by fungus Armillaria luteo-virens Sacc ZJUQH100-6.Fractional factorial design and response surface methodology were applied to optimize the main parameters that affect betulinic acid production in the growing-cells system. Results indicated that the addition of Tween 80 and substrate concentration were identified as the significant factors on betulinic acid formation, and the central composite experimental design was then adopted to derive a statistical model for optimizing biotransformation conditions. The optimum conditions were observed at pH 6·0, 0·57% Tween 80, 15 mg l(-1) betulin and at 3 days of stage of inoculation.Under the optimized conditions, the highest productivity of betulinic acid predicted was 9·32%, which increased by 74·53% in comparison with that of the nonoptimized. The verified experiment revealed that the model can well simulate betulin biotransformation. Moreover, the bioconversion of betulin and betulin-28-monooxygenase activities was compared between the optimized and the nonoptimized conditions.Current data imply that betulinic acid production from betulin can be effectively enhanced through biotransformation optimization strategy.