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.

Development of a real-time impedance matching system for ion cyclotron resonance heating in experimental advanced superconducting tokamak

To achieve stable operation of an ion cyclotron resonance heating (ICRH) system in the Experimental Advanced Superconducting Tokamak (EAST), a real-time impedance matching system needs to be established to respond to antenna load variation during long pulse discharges. A new impedance matching method based on capacitors was proposed in this study. By considering the reflected voltage of the transmission line as the feedback parameter, the real-time impedance-matching system can quickly control the motors based on a programmable logic controller to determine the minimum reflection voltage. A real-time impedance matching system was successfully used on the test platform in the laboratory and on the ICRH system in EAST. A significant result is that we can match the variable impedance within 1 s by suitably adjusting the motor controller to ensure high-power and long-pulse operation of the ICRH system to satisfy the requirements of the EAST experiment.

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.

[Biosafety risk of laboratory-acquired infection and countermeasures based on human factors]

Biosafety of pathogenic microbiology laboratories generally highlights the use of protective equipment, procedures, and operating practices to protect personnel and the environment from potentially hazardous biological materials. Under the current complex situation where traditional and non-traditional biosafety issues coexist, laboratory-acquired infection (LAI) of pathogenic microorganisms may cause illness, disability and even death. Pathogenic microorganisms may also be carried to the surrounding environment, causing community infection, which should be taken seriously. Analysis of LAI cases helps to understand the causes of exposure and learn lessons from post-exposure prophylaxis to be prepared and even prevent problems before they happen. Human factors cause most LAIs, laboratory activities related to aerosolization, laboratory activities related to sharps materials, low ability of personnel performing the work, and deficiencies in laboratory facilities or management are the four main factors. This study focuses on the human factors that lead to LAI, combined with confirmed cases, discusses the biosafety risks of pathogenic microorganism laboratories, reviews the development and evolution of biosafety laboratories and the current protection measures for experimenters, and accordingly puts forward countermeasures and suggestions.

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.

[Establishment of a recombined mannose-binding lectin protein-magnetic beads-enriched binding recombinant enzyme-assisted polymerase chain reaction assay for Candida in blood samples]

Objective: To establish a nested recombinant enzyme-assisted polymerase chain reaction (RAP) technique combined with recombined mannose-binding lectin protein (M1 protein)-magnetic beads enrichment for the detection of Candida albicans (C. albicans) and Candida tropicalis (C. tropicalis) in blood samples for the early diagnosis of candidemia albicans and candidiemia tropicalis. Methods: The primer probes for highly conserved regions of the internal transcribed spacerregions of C. albicans and C. tropicalis were deigned to establish RAP assays for the detections of C. albicans and C. tropicalis; The sensitivity and reproducibility of nucleic acid tests with gradient dilutions of standard strains and specificity of nucleic acid tests with common clinical pathogens causing bloodstream infection were condcuted. M1 protein-magnetic bead enriched plasma C. albicans and C. tropicalis were used for RAP and PCR in with simulated samples and the results were compared. Results: The sensitivity of the established dual RAP assay was 2.4-2.8 copies/reaction, with higher reproducibility and specificity. M1 protein-magnetic bead enrichment of pathogen combined with the dual RAP assay could complete the detections of C. albicans and C. tropicalis in plasma within 4 hours. Fie the pathogen samples at concentration <10 CFU/ml, the number of the samples tested by RAP was higher than that tested by PCR after enrichment. Conclusion: In this study, a dual RAP assay for the detections of C. albicans and C. tropicalis in blood sample was developed, which has the advantages of accuracy, rapidity, and less contaminants and has great potential for rapid detection of Candidemia.

[One case of adult-onset dystonia presenting with chronic progressive external ophthalmoplegia]

We report a case of adult-onset dystonia presenting with chronic progressive external ophthalmoplegia. The patient had ptosis in both eyes, particularly the left eye, for no obvious reason since the age of 10, which was progressively aggravated. The clinical diagnosis was chronic progressive external ophthalmoplegia. However, whole gene sequencing revealed the mitochondrial A3796G missense mutation, so the patient was clearly diagnosed as adult-onset dystonia and given treatment to reduce blood glucose and improve muscle metabolism. The A3796G mutation in the ND1 subunit of the mitochondrial complex leading to ophthalmoplegia is relatively rare, requiring a combination with genetic testing for confirmation of diagnosis.

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.

[The value of CMR high-risk attributes in predicting ventricular remodeling in ST-segment-elevation myocardial infarction patients with mildly reduced or preserved ejection fraction]

Objective: To evaluate the predictive value of a multiparametric cardiac magnetic resonance (CMR) approach for ventricular remodeling in ST-segment-elevation myocardial infarction (STEMI) patients with mildly reduced or preserved left ventricular ejection fraction (LVEF). Methods: This study is a prospective cohort study. STEMI patients with acute LVEF>40% after primary percutaneous coronary intervention (PCI) in Beijing Anzhen Hospital from October 2019 to September 2021 were enrolled. All patients received acute (3-7 days) and follow-up (3 months) CMR post-PCI. According to absence or presence of ventricular remodeling, patients were divided into ventricular remodeling group and non-ventricular remodeling group. Basic clinical characteristics and CMR indicators were analyzed and compared between the two groups. Logistic regression and receiver operating characteristic (ROC) curves were used to explore the predictive performance of CMR high-risk attributes for ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The predictive value of combining multiple high-risk characteristics of CMR for ventricular remodeling was analyzed and compared with the traditional clinical risk factor model. Results: A total of 123 STEMI patients were enrolled (aged (57.1±11.1) years, 102 (82.9%) males). There were 97 cases (78.9%) patients in the non-ventricular remodeling group and 26 cases (21.1%) in the ventricular remodeling group. After adjustment for clinical risk factors, stroke volume<51.6 ml, global circumferential strain>-13.7%, infarct size>39.2%, microvascular obstruction>0.5%, and myocardial salvage index<43.9 were independently associated with ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The incidence of ventricular remodeling increased with the increasing number of CMR high-risk attributes (P<0.01). The number of CMR high-risk attributes ≥3 was an independent predictor of adverse remodeling (adjusted OR=5.95, 95 CI%: 2.25-15.72, P<0.01) in STEMI patients with mildly reduced or preserved LVEF. Furthermore, the number of CMR high-risk attributes had incremental predictive value over baseline clinical risk factors (area under curve: 0.843 vs. 0.696, P<0.01). Conclusions: In STEMI patients with mild reduced or preserved LVEF, 5 CMR characteristics are associated with ventricular remodeling. The combination of ≥3 CMR high-risk characteristics is an independent predictor of ventricular remodeling, which has incremental predictive value beyond traditional risk factors in this patient cohort.

Impedance matching system using triple liquid stub tuners for high-power ion cyclotron resonance heating in EAST tokamak

Ion cyclotron resonance heating (ICRH), one of the main auxiliary methods, for high-power and long-pulse plasma heating had been developed in Experimental Advanced Superconducting Tokamak (EAST). An impedance matching system, one important part of ICRH, had been developed for high-power injection and transmitter protection by reducing the reflected power from the antenna. The input impedance in the outlet of the stub tuner can be measured by voltage-current probes installed on the coaxial transmission line between the antenna and triple liquid stub tuners, and the optimum liquid levels in the stub tuners can be calculated based on the input impedance. The calculation and adjustment process of the optimum liquid levels are described comprehensively in this article. Finally, impedance matching had been achieved between two shots during EAST experiments. In the near future, a real-time impedance matching system will be developed to prevent large variations of the ICRH antenna impedance and achieve steady-state and long-pulse operation with the ICRH system.

[Early effect of extracorporeal membrane oxygenation and factors related to early outcome in adult patients with fulminant myocarditis]

Objective: To evaluate the efficacy within the first 24 h post extracorporeal membrane pulmonary oxygenation (ECMO) and the impact of early efficacy on the prognosis of adult patients with fulminant myocarditis (FM). Methods: This retrospective case analysis study included hospitalized patients (age≥18 years) who were diagnosed with fulminant myocarditis from November 2016 to May 2021 in the First Affiliated Hospital of Zhengzhou University. Patients were divided into survival or non-survival groups according to treatment outcomes. The age, sex, treatments, drug use, ECMO use, clinical and laboratory data (before and 24 h after the use of ECMO) were analyzed. The change rate of clinical and laboratory data after 24 h use of ECMO was calculated to find differences between two groups. Multivariate logistic regression was used to analyze the related factors with in-hospital death and complication between the two groups. Results: A total of 38 FM patients treated with ECMO were included. There were 23 cases (60.5%) in the survival group, aged (39.6±13.7) years, and 17 (73.9%) cases were female. The total ECMO time was (134.4±71.3)h. There were 15 cases (39.5%) in non-survival group, aged (40.0±15.8) years, and there were 12(80.0%) female, the ECMO time was (120.1±72.4) h in this group. The proportion of tracheal intubation and continuous renal replacement therapy in the survivor group and dosage of norepinephrine within 24 h after ECMO implantation were significantly less than in non-survival group (all P<0.05). There was no significant difference in all efficacy related biochemical indexes between two groups before ECMO use. The levels of lactic acid, procalcitonin, creatinine, alanine aminotransferase, aspartate aminotransferase, creatine kinase-MB, cardiac troponin I and N-terminal B-type natriuretic peptide prosoma were significantly less in survival group than in non-survival group at 24 h after the use of ECMO (all P<0.05). Results of multivariate logistic regression analysis showed that the higher 24 h change rate of creatinine (OR=0.587, 95%CI 0.349-0.986, P=0.044) and creatine kinase-MB (OR=0.177, 95%CI 0.037-0.841, P=0.029) were positively correlated with reduced risk of in-hospital mortality. The central hemorrhage and acute kidney injury in survival group were less than in non-survivor group (P<0.05). Conclusions: After 24 h early use of ECMO in FM patients, the improvement of various efficacy related biochemical test indexes in the survival group was better than that in the non-survival group. Faster reduction of creatine kinase-MB and creatinine values within 24 h ECMO use is positively correlated with reduced risk of in-hospital mortality in adult patients with FM.

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.

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.

Enhanced high temperature ferromagnetism in Bi1-xRxFeO3(R= Dy, Y) compounds

In this work we report experimental evidence for the weak high-temperature ferromagnetism in Bi1-xRxFeO3(R= Dy, Y) compounds by systematic characterizations, excluding the possible side-effects from other iron-based impurities. Remarkable saturated magnetic moment was observed in the Y-substituted samples, Bi1-xYxFeO3, which is larger than the moment obtained in Bi1-xDyxFeO3, the Dy-substituted samples with antiferromagnetic background. The physical origin of the weak ferromagnetic transition is discussed and serious lattice distortions have been identified based on the x-ray diffraction and Raman scattering data, although the rhombohedral structure symmetry remains unchanged upon the substitutions. It is believed that the structural distortion suppressed cycloid spin structure is the main factor for the enhanced magnetization in Bi1-xRxFeO3compounds. Additionally, the Dy3+-Fe3+antiferromagnetic coupling, which strengthens the antiferromagnetic interaction in Bi1-xDyxFeO3compounds, acts as the driving force for the magnetic discrepancy between Bi1-xYxFeO3and Bi1-xDyxFeO3samples.

[Application of diffusion weighted imaging in accurate diagnosis of middle ear cholesteatoma]

Objective: To evaluate the accuracy of diffusion weighted magnetic resonance imaging (DWI-MRI) combined with high resolution temporal bone CT (HRCT) in the location diagnosis of middle ear cholesteatoma and its value in the postoperative follow-up. Methods: 134 patients with inital cholesteatoma and 22 patients with suspected recurrent cholesteatoma were selected for HRCT, conventional MRI and DWI examination. Based on the intraoperative and pathological diagnosis, DWI and HRCT images were combined to evaluate the consistency between the lesion location and invasion area of the initial cholesteatoma and intraoperative lesions. The results of HRCT and DWI in the diagnosis of recurrent middle ear cholesteatoma were statistically analyzed to evaluate their diagnostic efficacy. Results: The accuracy rate of DWI combined with HRCT was 90.3%.The sensitivity, specificity, positive predictive value and negative predictive value of HRCT and DWI in the diagnosis of recurrent middle ear cholesteatoma were 27.8%, 75.0%, 83.3%, 18.8% and 100%, 75.0%, 94.7% and 100%, respectively, and the Kappa values consistent with the pathological results were 0.024 and 0.843, respectively. Chi-square test confirmed that there were differences in the diagnosis between groups (P<0.001). Conclusions: Combined with the high sensitivity of DWI and the high resolution of HRCT, the accuracy of preoperative positioning of the newly diagnosed cholesteatoma can be improved and surgery strategy can be guided. DWI is also of high diagnostic value for recurrent cholesteatoma in the middle ear.

[CT manifestations and prognosis of acute paraquat induced lung injury]

Objective: To investigate the CT features of lung injury induced by paraquat poisoning and its relationship with prognosis, and to provide reference for the judgment of the condition and prognosis of paraquat poisoning. Methods: 146 cases of paraquat poisoning patients were treated in the Third People's Hospital of Xuzhou City from January 2013 to April 2016. The cases were divided into mild group, moderate-severe group and fulminant group according to the concentration of paraquat in urine. The clinical data and CT imaging findings were analyzed and reconstructed in three-dimensional reconstruction. The extent of the lesion was observed and the relationship between CT and prognosis was explored. Results: Paraquat lung injury has many manifestations on CT images, and it's performance can be intersecting at the same time. Early lesions lighter cases, late CT imaging lesions can be completely absorbed or residual fibrosis, the prognosis was good; the early lesion was pulmonary consolidation, pleural effusion cases, the late CT image was usually pleural thickening and bronchiectasis, the prognosis was relatively good; early lesions were large patches of ground glass opacity cases, finally, pulmonary fibrosis was common, the mortality rate of 56.57%. There were significant differences in the extent of lung injury between different groups (P<0.001) , and the difference in mortality was statistically significant when the lung injury was different (P<0.001) . Multivariate stepwise Logistic regression analysis showed that ground-glass opacity (OR value=2.013) , interstitial lung fibrosis (OR=3.779) and mediastinal emphysema (OR=33.118) were risk factors for death of lung injury caused by paraquat poisoning (P<0.05) . Conclusion: There were many manifestations on CT images of paraquat lung injury, and the manifestations of paraquat lung injury can be intersecting at the same time. The pulmonary manifestations and outcomes of different paraquat types were different. The CT manifestations of lung injury in paraquat poisoning were mainly exudative changes at early stage, and can be gradually absorbed or evolved into interstitial changes at later stage. The cumulative damage range can be used as a reference for evaluating the prognosis. Ground-glass opacity, interstitial pulmonary fibrosis and mediastinal emphysema are the risk factors for death of lung injury caused by paraquat poisoning.

Key space enhancement of optical chaos secure communication: chirped FBG feedback semiconductor laser

Optical chaos communication has advantages of high speed and long transmission distance. Unfortunately, the key space of the traditional transceiver, i.e. semiconductor laser with mirror feedback, is limited due to the time delay signature. In this paper, we propose and numerically demonstrate a key space enhancement by using semiconductor laser with optical feedback from a chirped fiber Bragg grating (FBG). The chirped FBG feedback can make feedback delay a key parameter by eliminating the time delay signature. Moreover, the grating dispersion and center frequency can also be used as new keys. As a result, the dimension of key space is increased. By taking a bidirectional communication scheme as an example, numerical results show that the key space is raised by 2⁴⁴ times as against mirror feedback with a data rate of 2.5 Gb/s and a coupling strength of 0.447. As the coupling strength decreases, the key space increases due to the fact that chaos synchronization becomes more sensitive to parameter mismatch.

A Correlational Study on Cerebral Microbleeds and Carotid Atherosclerosis in Patients with Ischemic Stroke

PURPOSE

This study aimed to investigate the correlation between cerebral microbleeds and carotid atherosclerosis in patients with ischemic stroke.

SUBJECTS AND METHODS

Patients with ischemic stroke treated in a hospital in China from 2016 to 2017 were enrolled in the study. Based on the results from susceptibility-weighted imaging, the patients were divided into cerebral microbleed and noncerebral microbleed groups. The degree of carotid atherosclerosis was assessed with carotid intima-media thickness (CIMB) and Crouse score of carotid plaque. The details of patients' demographic information, cerebrovascular disease-related risk factors, carotid atherosclerosis indices, cerebral microbleed distribution, and grading were recorded, compared, and analyzed.

RESULTS

Logistic regression analysis of the 198 patients showed that CIMB and Crouse score were significantly correlated with the occurrence of cerebral microbleeds. The CIMB thickening group (P = .03) and the plaque group (P = .01) were more susceptible to cerebral microbleeds. In the distribution of cerebral microbleed sites, Crouse scores were the highest in the mixed group and showed a statistically significant difference (P < .01). As the degree of carotid atherosclerosis increased, the average number of cerebral microbleeds also increased (P < .01). The receiver operating characteristic curve analysis of the carotid atherosclerosis indices showed a statistically significant difference. The CIMB value combined with the Crouse score was the best indicator (P < .01).

CONCLUSION

In patients with ischemic stroke, cerebral microbleeds are closely related to carotid atherosclerosis. Active control of carotid atherosclerosis is important to prevent cerebral microbleeds in patients with ischemic stroke.

Reproductive Cost Associated With Juvenile Hormone in Bt-Resistant Strains of Helicoverpa armigera (Lepidoptera: Noctuidae)

Transgenic Bacillus thuringiensis (Bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of Bt crops. The fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. In this study, we compared the life-history traits of three independent sets of Helicoverpa armigera (Hübner, 1809) adults, of each there were a susceptible population and a Cry1Ac-resistant population derived by selection from it. Confirming to the previous studies, resistant individuals exhibited fewer progeny, less fecundity, lower egg hatching rate, and longer adult longevity. And poor fecundity in resistant strains was associated with the decline of the mature follicular amount, the ovarian weight ratio, and the length of the longest ovarian tubule. Interestingly, the juvenile hormone (JH) level appeared higher in resistant strains relative to susceptible strains. Application of methoprene (JH analogue) in vivo was effective in reducing fecundity and hatchability with the up-regulation of detected JH titer. These results suggested that resistance against Bt toxin reduced the reproductive capacity of H. armigera, and JH level is affected in the tradeoff between reproductive capacity and Bt resistance.

[Clinical application study of non-invasive ventilation in the treatment of the pneumoconiosis patients with chronic type Ⅱ respiratory failure]

Objective: To observe the effect of early intervention and intermittent application of bi level positive air-way pressure ventilation (BiPAP) in patients with pneumoconiosis combined with chronic respiratory failure. Methods: Will meet the diagnostic criteria of pneumoconiosis in GBZ70-2009< >, the blood gas analysis in patients with chronic type II re-spiratory failure in 62 cases were randomly divided into rehabilitation treatment group 32 cases, control group of 30 cases. Pa-tients in the observation group were treated by on-invasive ventilation, while the control group were treated by the convention-al treatment. The data such as arterial blood gas、pulmonary function、the grade about dyspnea and echocardiography was col-lected from the both group before the beginning of the treatment and after the three months. Results: the PaO₂ level、FEV_1.0、FEV_1.0%、the grade of dyspnea and the Right Ventricular Ejection Fractions were not significantly different between the experi-mental group and the control before the start of the treatment (P>0.05) . After the three month treatment, the PaO₂ level of the observation was significantly lower the control (P<0.05) . The data about FEV_1.0、FEV_1.0% and the Right Ventricular Ejection Fractions were higher than the control group (P<0.05) . Conclusion: Non-invasive ventilation has exactly effect in the treat-ment of the pneumoconiosis patients with Chronic Respiratory Failure. It can improve the function of the heart and lung and ease the pain of patients.

Case Report Identification of a novel SLC45A2 mutation in albinism by targeted next-generation sequencing

Albinism is a diverse group of hypopigmentary disorders caused by multiple-genetic defects. The genetic diagnosis of patients affected with albinism by Sanger sequencing is often complex, expensive, and time-consuming. In this study, we performed targeted next-generation sequencing to screen for 16 genes in a patient with albinism, and identified 21 genetic variants, including 19 known single nucleotide polymorphisms, one novel missense mutation (c.1456 G>A), and one disease-causing mutation (c.478 G>C). The novel mutation was not observed in 100 controls, and was predicted to be a damaging mutation by SIFT and Polyphen. Thus, we identified a novel mutation in SLC45A2 in a Chinese family, expanding the mutational spectrum of albinism. Our results also demonstrate that targeted next-generation sequencing is an effective genetic test for albinism.

Altered expression of metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in cervical disc herniation patients

The aim of the current study was to examine matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) expression in patients with cervical disc herniation (CDH). A total of 127 specimens from CDH patients undergoing posterior spinal surgery were obtained for the case group, which was divided into three subgroups: lateral protrusion (N = 102), median protrusion (N = 18), and paramedian protrusion (N = 7). Another 55 specimens from subjects who had cervical spine trauma and underwent spinal canal decompression were obtained for the control group. Routine hematoxylin and eosin staining was performed for pathological diagnosis. Immunohistochemical (IHC) analysis was used to determine MMP-2 and TIMP-2 expression. Under light microscopy, MMP-2-positive cells presented brown-yellow or dark brown staining in the cell membrane or cytoplasm. MMP-2 expression in the case group was significantly higher than that in controls (P < 0.05). Furthermore, MMP-2 expression in the lateral and median protrusion groups was significantly higher compared to that in the paramedian protrusion group (both P < 0.05), while there was no apparent difference in MMP-2 expression between the lateral and median protrusion groups (P > 0.05). IHC results showed that TIMP-2 expression in cases was significantly lower than that in controls (P < 0.05). Spearman correlation analysis indicated that MMP- 2 was negatively correlated with TIMP-2 expression (r = -0.418, P < 0.001). In conclusion, MMP-2 expression increased, whereas TIMP- 2 expression decreased in CDH patients, suggesting that MMP-2 and TIMP-2 expression may contribute to CDH development.

Tradeoff between reproduction and resistance evolution to Bt-toxin in Helicoverpa armigera: regulated by vitellogenin gene expression

Evolution of resistance to insecticides usually has fitness tradeoffs associated with adaptation to the stress. The basic regulation mechanism of tradeoff between reproduction and resistance evolution to Bacillus thuringiensis (Bt) toxin in the cotton bollworm, Helicoverpa armigera (Ha), based on the vitellogenin (Vg) gene expression was analyzed here. The full-length cDNA of the Vg gene HaVg (JX504706) was cloned and identified. HaVg has 5704 base pairs (bp) with an open reading frame (ORF) of 5265 bp, which encoded 1756 amino acid protein with a predicted molecular mass of 197.28 kDa and a proposed isoelectric point of 8.74. Sequence alignment analysis indicated that the amino acid sequence of HaVg contained all of the conserved domains detected in the Vgs of the other insects and had a high similarity with the Vgs of the Lepidoptera insects, especially Noctuidae. The resistance level to Cry1Ac Bt toxin and relative HaVg mRNA expression levels among the following four groups: Cry1Ac-susceptible strain (96S), Cry1Ac-resistant strain fed on artificial diet with Bt toxin for 135 generations (BtR stands for the Cry1Ac Bt resistance), progeny of the Cry1Ac-resistant strain with a non-Bt-toxin artificial diet for 38 generations (CK1) and the direct descendants of the 135th-generation resistant larvae which were fed on an artificial diet without the Cry1Ac protein (CK2) were analyzed. Compared with the 96S strain, the resistance ratios of the BtR strain, the CK1 strain and the CK2 strain were 2917.15-, 2.15- and 2037.67-fold, respectively. The maximum relative HaVg mRNA expression levels of the BtR strain were approximately 50% less than that of the 96S strain, and the coming of maximum expression was delayed for approximately 4 days. The overall trend of the HaVg mRNA expression levels in the CK1 strain was similar to that in the 96S strain, and the overall trend of the HaVg mRNA expression levels in the CK2 strain was similar to that in the BtR strain. Our results suggest that the changes in reproduction due to the Bt-toxin resistance evolution in the BtR strain may be regulated by the Vg gene expression. The down-regulation of HaVg at the early stages resulted in a period of delayed reproduction and decreased fecundity in the BtR strain. This performance disappeared when the Bt-toxin selection pressure was lost.

Impacts of Bt rice expressing Cry1C or Cry2A protein on the performance of nontarget leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), under laboratory and field conditions

Transgenic rice expressing Bacillus thuringiensis Berliner (Bt) protein can effectively control target insects including stem borers and leaf folders. However, the potential effects of Bt rice on nontarget organisms including nontarget herbivores have not been fully evaluated. In the current study, ecological fitness parameters of the nontarget herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae), fed on T1C-19 (Cry1C) or T2A-1 (Cry2A) rice were compared with non-Bt rice (MH63) under laboratory conditions. A 2-yr field trial was also conducted to monitor the population dynamics of N. cincticeps in the Bt and control rice plots using the vacuum-suction machine and yellow sticky card traps. Laboratory results showed that there were no significant differences in some of biological parameters including egg developmental duration, adult fresh weight, adult longevity, and oviposition period when N. cincticeps fed on Bt or non-Bt rice was compared. However, the survival rate of N. cincticeps nymphs fed on T2A-1 Bt rice plants was significantly higher than that on the control. When N. cincticeps fed on T1C-19 Bt rice plants, its nymphal duration was significantly longer and fecundity significantly lower compared with those fed on both T2A-1 Bt and non-Bt rice plants; the preoviposition period of N. cincticeps fed on T1C-19 and T2A-1 Bt rice was also significantly shorter than those on non-Bt rice. Nonetheless, both seasonal density and population dynamics of N. cincticeps adults and nymphs were similar between Bt (T1C-19 and T2A-1) and non-Bt rice plots under field conditions. In conclusion, our results indicate that our two tested Bt rice lines would not lead to higher population of N. cincticeps. Long-term experiments to monitor the population dynamics of N. cincticeps at large scale need to be carried out to confirm the current results.

Dynamic hysteresis scaling of ferroelectric Pb(0.9)Ba(0.1)(Zr(0.52)Ti(0.48))O(3) thin films

We measure systematically the intrinsic scaling behavior of dynamic hysteresis for Pb(0.9)Ba(0.1)(Zr(0.52)Ti(0.48))O(3) (PBZT) ferroelectric thin films with Pt electrodes on Si substrates, utilizing the Sawyer-Tower technique. For the as-prepared thin films of similar thickness and microstructure, over the low frequency range, the scaling follows the power law [Formula: see text] under low E(0) and the power law [Formula: see text] under high E(0), where ⟨A⟩ is the hysteresis area, and f and E(0) are the frequency and amplitude of the external electric field. In the high- f range, the power law for low E(0) takes the form of [Formula: see text], while that for high E(0) takes the form of [Formula: see text]. It is identified that the dynamic behaviors at low frequency mainly come from the intrinsic domain reversal instead of others like the leakage current, while the depolarization field may influence the frequency exponents at high frequency. We study the temperature scaling of the hysteresis, indicating that the scaling under low E(0) is roughly consistent with the (Φ(2))(2) model. Finally, we argue that experimentally obtained power law scaling for Pb(Zr(0.52)Ti(0.48))O(3) thin films prepared under the given conditions may not be reliable due to the polarization fatigue effect.

Comparative flight performance of three important pest Adelphocoris species of Bt cotton in China

The massive adoption of Bt cotton throughout China has been accompanied by outbreaks of secondary pests such as Adelphocoris spp. (Heteroptera: Miridae). The Adelphocoris group primarily consists of three species: A. suturalis, A. fasciaticollis and A. lineolatus, which greatly differ in geographical distribution and seasonal dynamics. However, the underlying drivers of these differences remain to be understood. The study of flight behaviour of these three species can yield important insight into their spatial and temporal dynamics and help explain their distribution. We examined flight propensity of the three Adelphocoris spp. under a range of biological and environmental conditions using a computer-monitored flight-mill. Gender and mating status only had minor effects on flight performance in these species, while age exerted great effects on it. Flight capacity was low for one-day-old adults and increased with age until day 10-13, then gradually decreased afterwards. Temperature and relative humidity affected flight propensity, with 20-23 degrees C and 64-68% RH considered optimal for flight of all three species. Between-species comparisons indicated that A. suturalis and A. fasciaticollis had similar flight distance and duration, which were significantly greater than for A. lineolatus. Our findings provide crucial information for understanding geographical distribution and seasonal occurrence and for developing regional forecasting and pest management protocols for Adelphocoris species.

Competition between quantum fluctuations and antiferroelectric order in Ru-doped Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3)

The competition between quantum fluctuations and the antiferroelectric state in Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3) is investigated by measuring the low-temperature dielectric permittivity and by Raman spectroscopy. We demonstrate the significant impact of quantum fluctuations on the stability of the antiferroelectric polar order. It is revealed that the structural phase transitions can be modified by the quantum fluctuations, enhancing the stability of the high-symmetry phase and suppressing the antiferroelectric transitions. More importantly, a quantum antiferroelectric state, exhibiting similar behavior as the quantum ferroelectric state in terms of dielectric response, is identified. In addition, the effect of quantum fluctuations on the increasing permittivity at low temperature is also discussed.

The evolution of cotton pest management practices in China

The development of cotton pest management practices in China has followed a pattern seen for many crops that rely heavily on insecticides. Helicoverpa armigera resistance to chemical pesticides resulted in the unprecedented pest densities of the early 1990s. Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating H. armigera since 1997. The pest management tactics associated with Bt cotton have resulted in a drastic reduction in insecticide use, which usually results in a significant increase in populations of beneficial insects and thus contributes to the improvement of the natural control of some pests. Risk assessment analyses show that the natural refuges derived from the mixed-planting system of cotton, corn, soybean, and peanut on small-scale, single-family-owned farms play an important function in delaying evolution of cotton bollworm resistance, and that no trend toward Bt cotton resistance has been apparent despite intensive planting of Bt cotton over the past several years.

Antagonistic effect of pseudoginsenoside-F11 on the behavioral actions of morphine in mice

The antagonistic effect of pseudoginoside-F11 (PF(11)) on the various actions of morphine was studied in mice. The results demonstrated that PF(11), at the doses of 4 and 8 mg/kg, PO, significantly inhibited morphine (10 mg/kg, SC)-induced memory impairment in the Morris water maze test. PF(11), at 4 mg/kg, PO, did not influence conditioned place preference per se, yet markedly blocked the conditioned place preference to morphine. PF(11), at the doses of 4 and 8 mg/kg, PO, also significantly antagonized morphine (5 mg/kg, SC)-induced analgesia tested by tail pinch method. PF(11), at 4 mg/kg, PO, did not influence locomotor activity per se, yet inhibited the development of the reverse tolerance, as shown by the increase in locomotor activity, to morphine. At the doses of 4 and 8 mg/kg, PO, PF(11) significantly antagonized the development of analgesia tolerance to morphine in the tail pinch test. Thus, the above results demonstrate for the first time that PF(11) can antagonize some actions of morphine. However, the mechanism of action of PF(11) merits further evaluation.

Protective effects of pseudoginsenoside-F11 on scopolamine-induced memory impairment in mice and rats

This study assessed the effects of pseudoginsenoside-F11, a component of Panax quinquefolium L., on scopolamine-impaired memory performance in mice and rats. In the one-trial step-down and step-through passive avoidance tests, although pseudo-ginsenoside-F11 used alone did not affect passive avoidance behaviour in naive mice, the latency of avoidance shortened by intraperitoneal scopolamine (2 mg kg(-1)) was prolonged after intragastric administration of pseudoginsenoside-F11 (2 or 4 mg kg(-1), for five days) in both test systems in mice. In the water-maze test, in mice, the time taken to locate the platform after administration of pseudoginsenoside-F11 was shorter than that after administration of scopolamine (1 mg kg(-1), i.p.). In the two-way active avoidance response test, the latency of avoidance was significantly shorter for the pseudoginsenoside-F11-(1.2 or 2.4 mg kg(-1), i.g. for five days) and scopolamine-treated group than for the group of rats given scopolamine only (2 mg kg(-1), i.p.). The percentage avoidance was also reduced after intraperitoneal injection of scopolamine, but was reversed by administration of pseudo-ginsenoside-F11. These results suggest that pseudoginsenoside-F11 antagonized the memory dysfunction induced by scopolamine. However, the mechanism of the memory facilitative action of pseudoginsenoside-F11 merits further elucidation.

A simple and rapid method for measuring unconjugated capsular polysaccharide (PRP) of Haemophilus influenzae type b in PRP-tetanus toxoid conjugate vaccine

The authors developed a simple and rapid method for quantitation of free capsular polysaccharide of Haemophilus influenzae type b (polyribosyl ribitol phosphate, PRP) in PRP-tetanus toxoid conjugate vaccine based on acid precipitation of tetanus toxoid (TT). Acid hydrolysis of PRP during the assay was not detected. The conditions used in the assay did not precipitate unconjugated PRP or adipic acid dihydrazide derivatized PRP. The method was highly reliable, reproducible and sensitive. The accuracy of the assay was confirmed by spiking known amounts of unconjugated PRP to PRP-TT conjugate preparations. A PRP-TT preparation, incubated at 37 degrees C for 6 months showing most of the PRP as unconjugated (87% determined by this method), was not immunogenic in mice for the PRP component even after two injections. In contrast, the same preparation held at 4 degrees C for 20 months, showing 17% unconjugated PRP, induced IgG antibodies to PRP which were boosted after second injection. Therefore, this method is very useful to evaluate the stability of PRP-TT conjugate vaccine. The assay may be useful for characterizing other polysaccharide-protein conjugate vaccines.

Determination of protein loading in biodegradable polymer microspheres containing tetanus toxoid

Various methods to determine loading of vaccine in biodegradable polymer microspheres encapsulating tetanus toxoid were evaluated. The microspheres were composed of poly (D-lactic acid) (PLA) and poly (DL-lactic-co-glycolic acid) (PLGA). Dissolution of microspheres in organic solvents such as methylene chloride, chloroform, or dimethyl sulfoxide and extraction of vaccine antigen or total protein with phosphate buffered saline gave variable results which depended upon the characteristics of the microspheres, such as type of polymer, excipients used in the microspheres and formulation conditions. Microspheres made from low molecular weight PLGA polymer and showing a large burst release exhibited up to 25% extraction of antigen whereas microspheres made from PLA microspheres with low burst release showed < 1% extraction. Extraction of total protein with 0.1 N NaOH and 5% sodium dodecyl sulfate showed results similar to those obtained with organic solvent extraction method. Partial digestion of microspheres with 6 N HCl at 60 degrees C for 20 h resulted in approximately 30% loss in TT protein by micro-bicinchoninic acid (BCA) assay. The major problem with this method was strong reactions in the micro-BCA assay of stabilizers, particularly sugars (glucose, sucrose) used in the microsphere formulations. Complete digestion of microspheres with 6 N HCl at 110 degrees C for 20 h or with 13.5 N NaOH at 121 degrees C for 1 h and quantitation of amino acids by a modified ninhydrin assay showed reproducible results on the protein loading in the microspheres. However, this method was affected by the presence of stabilizers, such as gelatin, which contain amino acids. Further, sucrose concentrations higher than 10% caused interference in the ninhydrin assay on samples hydrolyzed with 6 N HCl. In contrast, hydrolysis with 13.5 N NaOH did not show any interference by sucrose. Stabilizers used outside the microspheres for lyophilization purposes may be removed by washing the microspheres before loading determination or by dialysis but stabilizers used inside the microspheres would still cause interference. For reliable determination of total protein in the microspheres containing vaccines, we suggest complete digestion of microspheres with acid or base followed by amino acid analysis by colorimeteric assays such as ninhydrin method or using amino acid analyzers. The method needs to be optimized for each type of formulation to eliminate interference by the excipients. Alternatively, total protein nitrogen in the microspheres may be determined by the Kjel-dahl method if no amino acids or other nitrogen containing stabilizer is used inside the microspheres.

A case report of dorsal pancreas agenesis diagnosed by MRI and ERCP

We present a case of dorsal pancreas agenesis demonstrated by MR imaging. Careful observation with endoscopic retrograde cholangiopancreatography and MR imaging led to the precise diagnosis.

Liver disease associated with duck hepatitis B virus infection of domestic ducks

The liver disease associated with duck hepatitis B viremia was investigated in naturally infected ducks from Chi-tung county in China and in both naturally and experimentally infected ducks from the United States. Liver and serum specimens of adult Chinese ducks were examined for duck hepatitis B virus (DHBV) DNA by dot and gel blot hybridization. DHBV was found in serum and (in episomal form only) in livers of 6 of 11 birds exhibiting various degrees of chronic hepatitis. In 1 bird with hepatocellular carcinoma, DHBV DNA was detected at the limit of assay sensitivity and in another not at all, contrasting with findings in humans and woodchucks. In work with California Pekin and Khaki Campbell ducks, known amounts of DHBV were injected into the egg 10 days before, or into ducklings 1 day after, hatching and the livers were examined 6 weeks later. The majority of the injected ducklings had viremia detectable by hybridization 1 or 2 weeks after injection. The presence but not the amount of viremia correlated with incidence and degree of hepatitis, determined under code. The most severe instances of hepatitis, all in Pekin ducks, resembled the hepatitis in adult Chinese ducks of Chi-tung county. Severe and moderate hepatitis were found only in indoor-caged injected animals with viremia and in some uninjected birds without viremia that had been kept in outdoor flocks. The latter hepatitis, as some hepatitis in adult Chinese ducks, may not be related to DHBV. Mild and insignificant hepatitis were also found in injected and noninjected ducklings, some of which had the vertically transmitted spontaneous viremia previously described. The good correlation of experimentally induced viremia with incidence and severity of hepatitis in the Pekin duckling provides a simple, rapid, and relatively inexpensive model to study the relation of lesions to hepatitis B family infection in nonprimates.

Hemoglobin Quin-Hai, beta 78 (EF2) Leu replaced by Arg, a new abnormal hemoglobin found in Guangdong, China

An electrophoretically slowly moving hemoglobin variant, Hb Quin-Hai was found in an 8-year-old boy and in his father, during a survey for abnormal hemoglobins in Quin-Hai County, Hainan Island, Guangdong, P.R.C. Both carriers were clinically and hematologically normal. Structural studies indicated a new variant beta 78 (EF2) Leu replaced by Arg.