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.

[Efficacy of Activated Autologous Hematopoietic Stem Cell Transplantation in the Treatment of Acute Myeloid Leukemia]

OBJECTIVE

To compare the efficacy of activated autologous bone marrow and peripheral blood hematopoietic stem cell transplantation (Auto-HSCT) and matched sibling donor allogeneic hematopoietic stem cell transplantation (MSD-HSCT) for the first complete remission of adult acute myeloid leukemia (AML-CR1).

METHODS

For 86 adult patients with first complete remission of AML who underwent auto-HSCT (41 cases) and MSD-HSCT (45 cases) in our hospital from June 2012 to June 2020, the patients were treated with modified MAC ［Malflane 160 mg/(m2·d), -3 days, Ara-C 2 g/(m2·2), -3 days 21∶00, -2 days 9∶00, CTX 60 mg/(kg·d),-3 d, -2 d］, the stem cells were activated by IL-2 (1 000 U/ mL), IFN-α (100 U/ mL) and IFN-γ (100 U/ml). The overall survival (OS), leukemia free survival (LFS), cumulative incidence of recurrence (CIR) and non-recurrence mortality (NRM) of patients with different types of transplantation were compared.

RESULTS

The 3-year OS rates of Auto-HSCT group and MSD-HSCT group were 75% and 69.5%, and the 3-year LFS rates were 70.6% and 82.4%, respectively. There was no statisticaly significant difference in the 3-year OS rates of low risk, medium risk and high risk patients in the Auto-HSCT and MSD-HSCT group (90.2% vs 87.5%, 68.4% vs 68.8%, 28.6% vs 53.3%), the LFS rates of low risk, medium risk and high risk patients in the auto-HSCT and MSD-HSCT group were 90.2% and 87.5%(P=0.838), 71.8% and 91.7%(P=0.184), 0 and 67.5%(P=0.027), respectively. The NRM of Auto-HSCT and MSD-HSCT group were 4.9% and 20% (P=0.036), and CIR were 24.4% and 13.3% (P=0.188). Univariate analysis showed that the survival time of patients was significantly correlated with the number of CR courses and disease risk stratification (P=0.005, P=0.000). Cox multivariate analysis showed that disease risk stratification was an independent risk factor affecting OS (P=0.001).

CONCLUSION

For adult patients with primary AML-CR1, Auto-HSCT is safe and effective. In the absence of sibling donor, Auto-HSCT can be regarded as an effective post-remission treatment for patients with intermediate risk AML-CR1.

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.

[Analysis of Pathogenic Bacterial Spectrum, Drug Resistance and Risk Factors for Mortality of Bloodstream Infection in Patients with Hematologic Diseases]

OBJECTIVE

To analyze the pathogenic bacterial spectrum, drug resistance, and risk factors associated with multidrug-resistant bacterial infection and mortality in patients with hematologic diseases complicated by bloodstream infections, so as to provide reference for rational drug use and improving prognosis.

METHODS

Positive blood culture specimens of patients with hematologic diseases in two Class A tertiary hospitals of Shanxi province from January 2019 to December 2021 were retrospectively analyzed. Pathogen distribution, drug resistance and outcomes of patients with bloodstream infection were investigated, then the multivariate logistic analysis was performed to analyze the risk factors of multidrug-resistant bacterial infection and factors affecting prognosis.

RESULTS

203 strains of pathogens were identified, mainly Gram-negative bacteria (GNB) (69.46%, 141/203), of which Escherichia coli (E.coli) had the highest incidence (41.13%, 58/141), followed by Klebsiella pneumoniae (20.57%, 29/141) and Pseudomonas aeruginosa (12.77%, 18/141). Extended-spectrum beta-lactamase (ESBL)-producing E.coli and Klebsiella pneumoniae were 46.55% (27/58) and 37.93% (11/29), respectively. Carbapenem-resistant Gram-negative bacteria accounted for 10.64% (15/141). And Gram-positive bacteria accounted for 27.59% (56/203), Staphylococcus epidermidis, Streptococcus pneumoniae, and Staphylococcus aureus were the most frequently isolated pathogen among Gram-positive bacteria (14.29%, 12.50% and 10.71%, respectively), of which methicillin-resistant Staphylococcus aureus accounted for 33.33% (2/6), coagulase-negative staphylococci accounted for 87.50% (7/8), without vancomycin- or linezolid-resistant strain. Additionally, fungi accounted for 2.95% (6/203), all of which were Candida. Multidrug-resistant Gram-negative bacteria (MDR-GNB) accounted for 53.90% (76/141). Duration of neutropenia >14 days was a risk factor for developing MDR-GNB infection. The 30-day all-cause mortality was 10.84%. Multivariate logistic regression analysis showed that the significant independent risk factors for mortality were age≥60 years (P <0.01, OR =5.85, 95% CI: 1.80-19.07) and use of vasopressor drugs (P <0.01, OR =5.89, 95% CI: 1.83-18.94).

CONCLUSION

The pathogenic bacteria of bloodstream infection in patients with hematological diseases are widely distributed, and the detection rate of multidrug-resistant bacteria is high. The clinicians should choose suitable antibiotics according to the results of bacterial culture and antibiotic susceptibility test.

[Clinical Characteristics and Risk Factors for 30-Day Mortality in Patients with Hematologic Diseases Infected by Carbapenem-Resistant Organisms]

OBJECTIVE

To explore the clinical characteristics of hospitalized patients with hematologic diseases complicated with carbapenem-resistant organisms (CRO) infection and analyze the risk factors of 30-day all-cause mortality.

METHODS

The clinical data and laboratory test data of 77 hospitalized patients with hematologic diseases complicated with CRO infection in department of hematology of the Third Hospital of Shanxi Medical University from January 2015 to December 2020 were retrospectively analysed, the risk factors of 30-day all-cause mortality after CRO infection were analyzed by multivariate logistic regression.

RESULTS

Among the total of 77 patients with hematologic diseases complicated with CRO infection, 29 died and 48 survived within 30 days of infection, with a case fatality rate of 37.66%. A total of 93 strains of CRO were isolated from these patients, of which Acinetobacter baumannii had the highest detection rate (25.81%, 24/93), followed by Pseudomonas aeruginosa (18.28%, 17/93). The lung was the most common site of CRO infection. The detected pathogens were highly resistant to carbapenems, and 64.52% (60/93) of the pathogens were resistant to imipenem with minimum inhibitory concentration (MIC)≥16 μg/ml. The results of the univariate analysis showed that albumin concentration <25 g/L (P =0.048), serum creatinine concentration≥120 μmol/L (P =0.023), age-adjusted Charlson comorbidity index (ACCI) (P =0.037) and primary treatments (supportive treatment, immunosuppressive therapy, chemotherapy, HSCT) (P =0.048) were significantly associated with 30-day all-cause mortality after infection. The results of multivariate logistic regression analysis showed that when CRO infection confirmed, albumin concentration <25 g/L (P =0.014, OR=6.171), serum creatinine concentration≥120 μmol/L (P =0.009, OR=10.867) were independent risk factors for 30-day mortality of patients with hematologic diseases complicated with CRO infection.

CONCLUSION

The mortality rate of CRO-infected patients with hematologic diseases is high. The detected pathogenic bacteria are highly resistant to imipenem. The albumin concentration <25 g/L and the serum creatinine concentration≥ 120 μmol/L at diagnosis of CRO infection were independent risk factors for 30-day mortality of the patients with hematologic diseases.

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.

[Clinical Characteristics and Nomogram Model of Nosocomial Infection in Patients with Newly Diagnosed Multiple Myeloma]

OBJECTIVE

To explore the clinical characteristics of nosocomial infection in newly diagnosed multiple myeloma(NDMM) patients, and establish a predictive nomogram model.

METHODS

The clinical data of 164 patients with MM who were treated in Shanxi Bethune Hospital from January 2017 to December 2021 were retrospectively analyzed. The clinical characteristics of infection were analyzed. Infections were grouped as microbiologically defined infections and clinically defined infections. Univariate and multivariate regression models were used to analyze the risk factors of infection. A nomogram was established.

RESULTS

164 patients with NDMM were included in this study, and 122 patients (74.4%) were infected. The incidence of clinically defined infection was the highest (89 cases, 73.0%), followed by microbial infection (33 cases, 27.0%). Among 122 cases of infection, 89 cases (73.0%) had CTCAE grade 3 or above. The most common site of infection was lower respiratory in 52 cases (39.4%), upper respiratory tract in 45 cases (34.1%), and urinary system in 13 cases (9.8%). Bacteria(73.1%) were the main pathogens of infection. Univariate analysis showed that ECOG ≥2, ISS stage Ⅲ, C-reactive protein ≥10 mg/L, serum Creatinine ≥177 μmol/L had higher correlation with nosocomial infection in patients with NDMM. Multivariate regression analysis showed that C-reactive protein ≥10 mg/L (P＜0.001), ECOG ≥2 (P=0.011) and ISS stage Ⅲ （P=0.024） were independent risk factors for infection in patients with NDMM. The nomogram model established based on this has good accuracy and discrimination. The C-index of the nomogram was 0.779（95%CI: 0.682-0.875）. Median follow-up time was 17.5 months, the median OS of the two groups was not reached (P=0.285).

CONCLUSION

Patients with NDMM are prone to bacterial infection during hospitalization. C-reactive protein ≥10 mg/L, ECOG ≥2 and ISS stage Ⅲ are the risk factors of nosocomial infection in NDMM patients. The nomogram prediction model established based on this has great prediction value.

[The Characteristics of T Lymphocyte Reconstitution after Haploid Hematopoietic Stem Cell Transplantation in SAA and Its Relationship with aGVHD]

OBJECTIVE

To investigate the recovery characteristics of T cell subsets in patients with severe aplastic anemia (SAA) who received haploid hematopoietic stem cell transplantation(HSCT) and its relationship with acute graft-versus-host disease(aGVHD).

METHODS

The clinical data of 29 SAA patients who received haploid hematopoietic stem cell transplantation in the department of hematology, Shanxi Bethune Hospital from June 2018 to January 2022 were retrospectively analyzed. The absolute counts of CD3⁺T, CD4⁺T, CD8⁺T lymphocytes and the ratio of CD4⁺T/CD8⁺T lymphocytes in all patients before transplantation, 14, 21, 30, 60, 90 and 120 days after transplantation were analyzed. The proportion of T lymphocytes was compared in the non-aGVHD group, the grade Ⅰ-Ⅱ aGVHD group and the grade III-IV aGVHD group.

RESULTS

The counts of all T cells in 27 patients were far below the normal level at 14 and 21 days after transplantation, but there was obvious heterogeneity. There was a certain relationship between T cell immune reconstitution and conditioning regimen, age, and immunosuppressive treatment before transplantation. CD3⁺T cells showed a steady upward trend at 30, 60, 90, and 120 days after transplantation, and returned to the normal levels at 120 days after transplantation; faster recovery of CD4⁺T cells was closely related to aGVHD, which was at 30, 60, 90, 120 days after transplantation showed a slow upward trend, and which was still far below the normal level of 120 days after transplantation. CD8⁺T cell counts began to recover at 14 and 21 days after transplantation, and the recovery was earlier than the CD4⁺T cells, and its recovery speed was rapid 30 and 60 days after transptantation, which showed an upward trend and exceeded the normal levels 90 days after transplantation. Since CD8⁺ T cells reconstituted quickly, while the CD4⁺ T cells reconstitution was slowly, which made the long-term CD4⁺T/CD8⁺T cell ratio after transplantation was inverted . Compared with the non-aGVHD group, the absolute counts of CD3⁺T, CD4⁺T, and CD8⁺T cells in the aGVHD group were significantly higher than those in the non-aGVHD group at each time period after transplantation. In the aGVHD group, grade Ⅲ-Ⅳ aGVHD occurred more frequently in the early post-transplantation period (within 14-21 days), the grade Ⅰ-Ⅱ aGVHD group mostly occurred within 30-90 days after transplantation, and CD3⁺T, CD4⁺T, CD8⁺T cell counts in the grade Ⅲ-Ⅳ aGVHD group were significantly higher than those in the grade Ⅰ-Ⅱ aGVHD group; and the greater the proportion of CD4⁺T, the more severe the degree of aGVHD.

CONCLUSION

The speed of T cell immune reconstitution after SAA haploid transplantation is different, which is related to the conditioning regimen, age, and immunosuppressive therapy before transplantation. The rapid recovery of CD4⁺ T cells is closely related to the occurrence of aGVHD.

[Analysis of WRKY transcription factor family based on full-length transcriptome sequencing in Polygonatum cyrtonema]

WRKY transcription factor family plays an important role in plant growth and development, secondary metabolite synthesis, and biotic and abiotic stress responses. The present study performed full-length transcriptome sequencing of Polygonatum cyrtonema by virtue of the PacBio SMRT high-throughput platform, identified the WRKY family by bioinformatics methods, and analyzed the physicochemical properties, subcellular localization, phylogeny, and conserved motifs. The results showed that 30.69 Gb nucleotide bases and 89 564 transcripts were obtained after redundancy removal. These transcripts had a mean length of 2 060 bp and an N50 value of 3 156 bp. Based on the full-length transcriptome sequencing data, 64 candidate proteins were selected from the WRKY transcription factor family, with the protein size of 92-1 027 aa, the relative molecular mass of 10 377.85-115 779.48 kDa, and the isoelectric point of 4.49-9.84. These WRKY family members were mostly located in the nucleus and belonged to the hydrophobic proteins. According to the phylogenetic analysis of WRKY family in P. cyrtonema and Arabidopsis thaliana, all WRKY family members were clustered into seven subfamilies and WRKY proteins from P. cyrtonema were distributed in different numbers in these seven subgroups. Expression pattern analysis confirmed that 40 WRKY family members had distinct expression patterns in the rhizomes of 1-and 3-year-old P. cyrtonema. Except for PcWRKY39, the expression of 39 WRKY family members was down-regulated in 3-year-old samples. In conclusion, this study provides abundant reference data for genetic research on P. cyrtonema and lays a foundation for the in-depth investigation of the biological functions of the WRKY family.

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 impact of second-donor lymphocyte infusion on secondary graft failure after allogeneic hematopoietic stem cell transplantation through activation of Foxp3 and regulatory T cells

Secondary graft failure (SGF) is a fatal complication of allogeneic hematopoietic stem cell transplantation without effective treatment methods, especially after haploidentical transplantation. This study aimed to analyze the efficacy of donor lymphocyte infusion (DLI) from a second donor in treating SGF and the underlying immune mechanisms. A second donor is a candidate donor who did not initially provide stem cells for HLA-matched sibling donor or HLA-haploidentical donor transplantation. We conducted a retrospective study of 237 patients with a median age of 38 years (range 9-56) for whom the degree of mixed chimerism (MC) and complete donor chimerism (CC), mRNA expression levels of Forkhead box P3 (Foxp3), and the proportion of regulatory T cells (Tregs) were regularly assessed. The median time to SGF was 62 days (range 41-117) after transplantation. Twenty-one patients with SGF received DLI, including 12 patients who initially received DLI from a second donor (i.e., a donor other than the transplantation [first] donor) and 9 patients who initially received DLI from the first donor but showed no response. Three of those 9 patients subsequently received DLI from a second donor. The incidence of acute GVHD and chronic GVHD induced by DLI from the second donor was significantly higher than that of DLI from the first donor (P = 0.006). Twenty-one patients with SGF exhibited synchronous MC, and the overall MC rate after transplantation was 65% (range 42%-85%).The proportion of Tregs significantly decreased in SGF patients, from a median of 2.61% ± 0.88% to 0.92% ± 0.23% at the indicated time point after transplantation (P = 0.03). Second-donor DLI resulted in a complete response (CR) in 13 patients, and MC gradually converted into CC; simultaneously, there was a significant increase in the mRNA level of Foxp3 and the proportion of Tregs (baseline, 0.92% ± 0.23% versus CR, 3.61% ± 0.82%; P = 0.01). For the patients who did not respond to DLI from either donor type, there was no significant change in donor chimerism, Foxp3 expression level or Treg proportion. Overall survival and disease-free survival 2 years after DLI were 66.7% ± 3.08% and 59.8% ± 4.11%, respectively. DLI from a second donor may be an effective treatment for SGF, and the mechanism is related to MC-to-CC conversion and activation of Foxp3 and Tregs.

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.

Effect of donor lymphocyte infusion from two types of donors on Mixed Chimerism with Secondary Graft Failure after allogeneic haematopoietic stem cell transplantation

Mixed chimerism (MC) and secondary graft failure (SGF) with recipient-or donor-type chimerism is a major obstacle in allogeneic hematopoietic stem cell transpl- antation (HSCT). Donor lymphocyte infusion(DLI) can eradicate minimal residual disease or be used to rescue a hematologic relapse, being able to induce durable remissions after HSCT.This study aimed to analyse the efficacy and immune mecha- nism of DLI from the original and alternative donor for patients of mixed donor chimerism with SGF . The alternative donor refers to the candidate relative donor who did not initially provide stem cells include HLA-matched sibling donor(MSD) or HLA- haploidentical donor (HID). We conducted a retrospective study of 246 patients with a median age of 37 (9-58) years who were regularly detected MC, complete donor chimera (CC) and regulatory T cells (Treg). The median diagnosis time of SGF was 69 (39-141) days after transplantation . Sixteen patients of SGF received DLI from the alternative donor, including 3 patients who chose DLI from the original donor with no initial response and 13 patients who directly chose DLI from the alternative donor. Sixteen patients with SGF exsisted mixed chimerism synchronously and the rate calculated overall chimerism of MC was 63% (range, 42%-85%) after transplantation. The proportion of Treg decreased significantly in SGF patients from a median of (2.66% ±0.80%) to (0.93%±0.57%) at a time point after transplantation (p=0.02).The DLI of the alternative donor in 14 patients achieved complete response and MC gradually convert to CC state, simultaneously there was significant increase in the Treg fraction [SGF vs CR: (0.93% ± 0.57%) vs (3.61%±0.82%), p=0.01)].For the clinical nonres- ponders from two types of donor there was no significant change in MC and Treg cells. The OS and DFS at 2 years after DLI were 69.7%±3.19 % and 61.3%±4.80%, respectively. DLI from the alternative donor may be an effective treatment for MC with SGF and the mechanism is closely related to the activation of Treg cells level.

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.

[Transcriptome and quality evaluation of Sichuan Dao-di herbs Zanthoxylum bungeanum]

&quot;Huajiao&quot; is dried ripe fruit peel of Zanthoxylum bungeanum or Z. schinifolium, is konwn as geoherbs, especially the &quot;Dahongpao&quot; cultivated in Hanyuan, Maoxian and Jiulong of Sichuan province. However, the genetic basis of Dao-di &quot;Huajiao&quot; is virtually unknown. The transcriptome of the fruit and leaf from Sichuan(Hanyuan, Jiulong, Lixian, Maoxian), Gansu(Wudu) province and Shaanxi(Fengxian) province was sequenced. Trinity de novo assembling resulted in a total of 177 616 unigenes. Through the KEGG, NR, SwissProt, Trembl, KOG/COG, GO, Pfam database comparision 106 644 annotated Unigene finally, 4 574 deferentially expressed genes were found in fruit between Sichuan and other provinces, including 3 740 up-regulated genes and 834 down-regulated genes. Among the up-regulated genes, 27 up-regulated genes were raleted to terpenoids, and 8 up-regulated genes were related to isoquinoline alkaloid bio-synthesis. Furthermore, it was also showed remarkable differences in groups which enrichment ratio of the diffe-rent expressed gene compared. The different expressed genes were annotated by the KEGG database into plant-pathogen interaction, plant hormone signal transduction and phenylpropanoid biosynthesis in fruit and leaf, but isoflavonoid bio-synthesis and betaine bio-synthesis were significantly different in fruit and leaf. The study laid a certain reference basis for comparison of quality and different expressed gene of Z. bungeanum from different groups.

Mechanisms of CXCR7 induction in malignant melanoma development

Malignant melanoma (MM) is a highly malignant skin tumor. The mechanism of MM pathogenesis and its signaling pathways are not well characterized. C-X-C chemokine receptor type 7 (CXCR7) has been reported to regulate cancer cell invasion. The present study sought to investigate the effects of CXCR7 on MM development. First, CXCR7 expression levels were assessed in the skin tumor tissue of patients with MM. Then, CXCR7 small hairpin RNA was used in M14 melanoma cells in a Transwell culture model and in a transplanted mouse model to test the effects of CXCR7. In addition, immunohistochemistry staining, reverse transcription-quantitative polymerase chain reaction and western blotting were used. The results revealed that CXCR7 expression levels were significantly higher in MM tissue compared with squamous cell carcinoma or basal cell carcinoma tissue. Knocking down CXCR7 in M14 cells significantly inhibited cell migration and invasion in the Transwell culture model. Furthermore, CXCR7 knockdown also significantly reduced the transplanted tumor size, weight and vascular number in the mouse model. It was concluded that CXCR7 interacts with C-X-C motif chemokine ligand 12 to activate the chemokine receptor signaling pathway, and to increase melanoma cell migration, invasion and development.

Effects of RMF on BKCa and Kv channels in basilar arterial smooth‑muscle cells of SHR

The current study observed the effects and investigated the mechanism of remifentanil (RMF) on the isolated cerebral basilar arteries of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. A pressure myograph system was used to observe and compare the effects of different concentrations of RMF (10⁻¹⁰-10⁻⁵ mol/l) on the diameter changes of freshly isolated cerebral basilar arteries, which have been pre-shrunk by phenylephrine (PE), an endothelium-independent vasoconstrictor. Vascular smooth-muscle cells of the cerebral basilar artery (BASMCs) were freshly obtained via enzymolysis. BKCa (large-conductance calcium-activated potassium channels) current (I_BKCa) and Kv (voltage-gated potassium channels) current (I_Kv) were recorded using a whole-cell patch-clamp technique. The changes in I_BKCa and I_Kv produced by different concentrations of RMF (10⁻¹⁰ to 10⁻⁵ mol/l) on the two types of rats with the holding potential of −40 mV were observed and compared. The cerebral basilar arteries of the SHR and WKY rats were relaxed by RMF in a concentration-dependent manner (P<0.05; n=5). At the same concentration, the diastolic effect of RMF on SHR was weaker than that observed in WKY rats (P<0.05, n=5). When the rats were pre-perfused with 10⁻³ mol/l of the BKCa channel blocker tetraethylammonium (TEA), the diastolic amplitudes of RMF in SHR and WKY rats were decreased, and the fitting curves shifted down (P<0.05; n=7 and 6, respectively). However, no statistically significant difference was observed with 10⁻³ mol/l of the Kv channel blocker 4-aminopyridine (4-AP; n=6 and 9, respectively; P>0.05). Outward currents were increased by RMF in both BASMCs of SHR and WKY rats in a voltage- and dose-dependent manner (P<0.05; n=6). At the same concentration, the effect of RMF on the outward currents in BASMCs of WKY rats was stronger than that on SHR (P<0.05; n=6). The enhancing effect of RMF can be partially blocked by either 10⁻³ mol/l TEA (P<0.05; n=6) or 10⁻³ mol/l 4-AP (P<0.05 or 0.01; n=6 and 9, respectively) however can be totally blocked by the mixture of TEA and 4-AP (P<0.05, n=7). RMF served a diastolic role in the cerebral basilar arteries of rats in a dose-dependent manner, likely by activating the BKCa and Kv channels. However, SHR demonstrated a less pronounced diastolic reaction to RMF than that observed in WKY rats.

[Isoliquiritigenin relaxes the cerebral basilar artery by enhancing BKCa current in spontaneously hypertensive rat: role of sGC/cGMP]

The purpose of the present study is to investigate the effect of isoliquiritigenin (ISL) on the cerebral basilar artery in spontaneously hypertensive rats (SHR). The change of SHR systolic pressure was measured by tail artery pressure measurement instrument before and after ISL intervention. After perfusion with 1 × 10(-5) mol/L phenylephrine (PE), 1 × 10(-5) mol/L PE + 1 × 10(-4) mol/L ISL and 1 × 10(-5) mol/L PE, the diameter of the cerebral basilar artery separated from SHR was measured by pressure myograph. The current of large-conductance calcium-activated potassium (BKCa) channel of SHR single vascular smooth muscle cell (VSMC) was recorded by whole-cell patch-clamp technique and the cGMP levels of basilar artery was evaluated by ELISA. The results showed that 1) after intervention with ISL for 14 days, the systolic pressure of SHR was decreased from (218.3 ± 1.6) mmHg to (119.2 ± 1.9) mmHg (P < 0.01), but there was no difference in systolic pressure between ISL-treated SHR and Wistar-Kyoto (WKY) rat; 2) 1 × 10(-4) mol/L ISL relaxed the SHR cerebral basilar artery (P < 0.01); 3) ISL significantly increased the outward current density of VSMC from SHR cerebral basilar artery (P < 0.01, n = 6), and the effect could be reversed by 1 × 10(-3) mol/L TEA (a BKCa channel inhibitor), but 3 × 10(-4) mol/L 4-AP (a Kv channel inhibitor) had no effect on the enhanced current density induced by ISL in VSMC; 4) 1 × 10(-5) mol/L Methylene blue (a sGC inhibitor) significantly inhibited the ISL-enhanced current density in VSMC (P < 0.05, n = 6); 5) ISL significantly increased the cGMP level of SHR basilar artery (P < 0.05, n = 6). The results suggest that the role of the ISL in relaxing the SHR cerebral basilar artery may be related to its effect in enhancing BKCa current by increasing the levels of cGMP in the VSMC.

Extracellular visfatin has nicotinamide phosphoribosyltransferase enzymatic activity and is neuroprotective against ischemic injury

AIM

Visfatin, a novel adipokine, is predominantly produced by visceral adipose tissue and exists in intracellular and extracellular compartments. The intracellular form of visfatin is proved to be nicotinamide phosphoribosyltransferase (NAMPT) and exhibits neuroprotection through maintaining intracellular NAD(+) pool. However, whether extracellular form of visfatin has NAMPT activity and the effect of extracellular visfatin in cerebral ischemia are unknown.

METHODS AND RESULTS

Plasma concentrations of visfatin, NAD(+) , and ATP were increased in mice upon cerebral ischemia. Cultured glia, but not neuron, was able to secrete visfatin. Oxygen-glucose deprivation (OGD) stress increased the secretion of visfatin from glia. Extracellular recombinant mouse wild-type visfatin, but not mouse H247A-mutant enzymatic-dead visfatin, had NAMPT enzymatic function in vitro. Treatment of wild-type visfatin, but not H247A-mutant enzymatic-dead visfatin, significantly attenuated detrimental effect of OGD on the cell viability and apoptosis in both cultured mouse neuron and glia. Treatment of neutralizing antibody, abolished the protective effect of extracellular visfatin on cell viability, but failed to block the antiapoptotic effect of extracellular visfatin. At last, we observed that plasma visfatin concentrations decreased in 6-month-old but not 3-month-old SHR-SP compared with that in age-matched Wistar-Kyoto rats. Inhibition of NAMPT enzymatic function of visfatin (by FK866) accelerated the occurrence of stroke in SHR-SP.

CONCLUSIONS

Extracellular visfatin has NAMPT enzymatic activity and maybe be neuroprotective just as intracellular visfatin in cerebral ischemic injury.

Deficiency of NG2+ cells contributes to the susceptibility of stroke-prone spontaneously hypertensive rats

AIMS

The purpose of this study is to investigate whether the NG2(+) cells, a class of oligodendrocyte progenitor cells, is involved in the pathophysiology of stroke in stroke-prone spontaneously hypertensive rat (SHR-SP).

METHODS

SHR-SP, SHR, Wistar-Kyoto rats (WKY), and C57BJ/6 mice were used. Immunohistochemistry was conducted to evaluate the number of NG2(+) cells in frozen brain sections. Demyelination was evaluated by Sudan black staining and serum level of myelin basic protein. Middle cerebral artery occlusion (MCAO) was performed to prepare experimental stroke model.

RESULTS

The number of NG2(+) cells was significantly decreased in infarct core and increased in penumbra in WKY rats after MCAO. In brain sections of 6-month-old SHR-SP, the number of NG2(+) cells was significantly (P < 0.01) less than that in age-matched SHR and WKY rats. However, this phenomenon was not observed in 3-month-old rats. Demyelination was found in 6-month-old SHR-SP but not in 3-month-old SHR-SP. Pharmacological treatment of cuprizone in mice induced demyelination and enlargement of cerebral infarction after MCAO.

CONCLUSION

The decline of NG2(+) cells may cause demyelination and contribute to the susceptibility of SHR-SP to ischemic brain injury.

Melting, expansion behavior and electric transport of In-filling in MgO nanotubes

By using a one-step approach, In-filled MgO nanotubes with diameters of 200-300 nm and lengths of several micrometers are synthesized. A Gatan heating experiment in a transmission electron microscope (TEM) shows that In-filling begins to melt far below the melting point 156.6 degrees C of In and abnormally shrinks upon increasing temperature above 270 degrees C. Massive In-filled MgO nanotubes were pressed into a disk and its resistance starts dramatically decrease upon increasing temperature above -150 degrees C, suggesting a temperature switch with a protective point -150 degrees C. The expansion and I-V characteristics were discussed.

[Construction of fusion gene vaccine of WT1 multi-epitope fused with stimulating epitope of mycobacterium tuberculosis heat shock protein 70 and its expression and immunogenicity]

This study was purposed to construct a fusion DNA vaccine containing WT1 multi-epitope and stimulating epitope of mycobacterium tuberculosis heat shock protein 70 and to detect its expression and immunogenicity. On the basis of published data, a multi-epitope gene (Multi-WT1) containing three HLA *0201-restricted CTL epitopes: one HLA*2402-restricted CTL epitope, two Th epitopes and one universal Th Pan-DR epitope (PADRE) was constructed. DNA-coding sequence was modified by Computer-Aided Design (CAD) to optimize proteasome-mediated epitope processing through the introduction of different amino acid spacer sequences. The synthetic nucleotide sequence was then inserted into an eukaryotic vector to construct the plasmid pcDNA3.1-WT1.For enhancing CTL activity, HSP70 fragment including stimulatory domain P407-426 was amplified by PCR from mycobacterial HSP70 gene and cloned into pcDNA3.1(+). Then Multi-WT1 was fused to the N-terminal of pcDNA3.1-mHSP70(407-426) to make the multi-epitope fusion gene vaccine pcDNA3.1-WT1-mHSP70(407-426). HEK-293T cells were transfected with this vaccine and the expressed product was identified by RT-PCR. Enzyme-linked immunospot assay (ELISPOT) was used to evaluate the immunological responses elicited by vaccine. The results showed that the most of WT1 epitopes could be correctly cleaved which was confirmed by software Net Chop 3.1 and PAPROCIanalysis. RT-PCR showed correct expression of target gene in HEK293T cells and ELISPOT showed specific T-cell responses. It is concluded that the eukaryotic expression vector PcDNA3.1-WT1-mHSP70(407-426) fusion gene has been successfully constructed and the immunity response is also elicited, which is a good candidate for further research of DNA vaccine.