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 plane3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Stringent Tests of Lorentz Invariance Violation from LHAASO Observations of GRB 221009A.

On 9 October 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time gamma-ray burst 221009A, recording the highest photon statistics in the TeV band ever obtained from a gamma-ray burst. We use this unique observation to place stringent constraints on the energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are E_{QG,1}>10 times the Planck energy E_{Pl} for the linear LIV effect, and E_{QG,2}>6×10^{-8}E_{Pl} for the quadratic LIV effect. Our limits on the quadratic LIV case improve previous best bounds by factors of 5-7.

Constraints on Ultraheavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations.

In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.

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.

[A real-world study of the clinical application of the Paris system for reporting urinary cytology in cancer hospital].

Objectives: To evaluate the clinical value of the Paris system for reporting urinary cytology (TPS) in the diagnosis of urothelial carcinoma (UC). Methods: A total of 1 744 cytological diagnostic records (from 751 cases) were collected retrospectively. All specimens were voided urines and histopathology as the gold standard. The sensitivity and specificity of urinary cytological diagnosis of UC and risk of high grade malignant (ROHM) in each diagnostic category were compared. Results: There were 360 cases with histopathology. The percentage of negative for high-grade urothelial carcinoma (NHGUC) was 30.1% (226/751), atypical urothelial cells (AUC) was 29.8% (224/751), suspicious for high-grade urothelial carcinoma (SHGUC) was 16.8% (126/751), high grade urothelial carcinoma (HGUC) was 21.2% (159/751), and non-urothelial malignancy (NUM) was 2.1% (16/751). The histpathologic ROHM corresponding to each cytological diagnosis category were 27.3% for NHGUC, 32.7% for AUC, 74.7% for SHGUC, 96.6% for HGUC and 100.0% for NUM, respectively. ROHM of SHGUC was significantly higher than that of AUC group, and the difference between the two groups was statistically significant (P＜0.001). ROHM of HGUC group was significantly higher than that of SHGUC group, and the difference was statistically significant (P＜0.001). With SHGUC as the cut-off value, the sensitivity and specificity of cytological diagnosis of HGUC were 76.7% (165/215) and 85.7% (18/21), and with HGUC as the cut-off value, the sensitivity and specificity of cytological diagnosis of HGUC were 53.0% (114/215) and 100.0% (21/21), respectively. Conclusions: Urine cytology has high sensitivity and specificity in the diagnosis of HGUC. The malignant risk of TPS varies with different diagnosis category. The high malignant risk population in cancer hospital leads to the relatively high malignant proportion and ROHM in each diagnosis category. Urinary cytology TPS reporting system is helpful to clinical management and has good clinical application value.

[A real-world study on the features of postpartum hepatitis flares in pregnant women with chronic HBV infection].

Objective: To analyze the clinical features of postpartum hepatitis flares in pregnant women with hepatitis B virus (HBV) infection. Methods: A retrospective study was conducted. Patients who met the enrollment criteria were included. Liver function and HBV virology tests were collected from pregnant women with chronic HBV infection at delivery, 6, 24, 36, and 48 weeks after delivery through the hospital information and test system. Additionally, antiviral therapy types and drug withdrawal times were collected. Statistical analysis was performed on all the resulting data. Results: A total of 533 pregnant women who met the inclusion criteria were included, with all patients aged (29.5±3.7) years old. A total of 408 cases received antiviral drugs during pregnancy to interrupt mother-to-child transmission. There was no significant difference in the levels of alanine aminotransferase (ALT, z = -1.981, P = 0.048), aspartate aminotransferase (AST, z = -3.956, P < 0.001), HBV load (z = -15.292, P < 0.001), and HBeAg (z = -4.77, P < 0.001) at delivery in patients who received medication and those who did not. All patients ALT, AST, total bilirubin, direct bilirubin, and albumin showed an upward trend within six weeks after delivery. A total of 231 cases developed hepatitis within 48 weeks after delivery. Among them, 173 cases first showed ALT abnormalities within six weeks postpartum. Conclusion: Hepatitis flare incidence peaked six weeks after delivery or six weeks after drug withdrawal in pregnant women with chronic HBV infection.

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.

[The efficacy of radiotherapy based combined therapy for unresectable locally invasive bladder cancer and its associated factors analysis].

Objective: Retrospective analysis of the efficacy and influencing factors of bladder preservation integrated therapy for unresectable invasive bladder cancer confined to the pelvis was done, also including the bladder function preservation and adverse effects analysis. Methods: Sixty-nine patients with unresectable locally invasive bladder cancer who received radiotherapy-based combination therapy from March 1999 to December 2021 at our hospital were selected. Among them, 42 patients received concurrent chemoradiotherapy, 32 underwent neoadjuvant chemotherapyand 43 with transurethral resection of bladder tumors (TURBT) prior to radiotherapy. The late adverse effect of radiotherapy, preservation of bladder function, replase and metastasis and survival were followed-up. Cox proportional hazards models were applied for the multifactorial analysis. Results: The median age was 69 years. There were 63 cases (91.3%) of uroepithelial carcinoma, 64 of stage Ⅲ and 4 of stage Ⅳ. The median duration of follow-up was 76 months. There were 7 grade 2 late genito urinary toxicities, 2 grade 2 gastrointestinal toxicities, no grade 3 or higher adverse events occurred. All patients maintained normal bladder function, except for 8 cases who lost bladder function due to uncontrolled tumor in the bladder. Seventeen cases recurred locally. There were 11 cases in the concurrent chemoradiotherapy group with a local recurrence rate of 26.2% (11/42) and 6 cases in the non-concurrent chemoradiotherapy group with a local recurrence rate of 22.2% (6/27), and the difference in local recurrence rate between the two groups was not statistically significant (P=0.709). There were 23 cases of distant metastasis (including 2 cases of local recurrence with distant metastasis), including 10 cases in the concurrent chemoradiotherapy group with a distant metastasis rate of 23.8% (10/42) and 13 cases in the non-concurrent chemoradiotherapy group with a distant metastasis rate of 48.1% (13/27), and the distant metastasis rate in the non-concurrent chemoradiotherapy group was higher than that in the concurrent chemoradiotherapy group (P=0.036). The median 5-year overall survival (OS) time was 59 months and the OS rate was 47.8%. The 5-year progression-free survival (PFS) time was 20 months and the PFS rate was 34.4%. The 5-year OS rates of concurrent and non-concurrent chemoradiotherapy group were 62.9% and 27.6% (P<0.001), and 5-year PFS rates were 45.4% and 20.0%, respectively (P=0.022). The 5-year OS rates of with or without neoadjuvant chemotherapy were 78.4% and 30.1% (P=0.002), and the 5-year PFS rates were 49.1% and 25.1% (P=0.087), respectively. The 5-year OS rates with or without TURBT before radiotherapy were 45.5% and 51.9% (P=0.233) and the 5-year PFS rates were 30.8% and 39.9% (P=0.198), respectively. Multivariate Cox regression analysis results showed that the clinical stage (HR=0.422, 95% CI: 0.205-0.869) was independent prognostic factor for PFS of invasive bladder cancer. The multivariate analysis showed that clinical stages (HR=0.278, 95% CI: 0.114-0.678), concurrent chemoradiotherapy (HR=0.391, 95% CI: 0.165-0.930), neoadjuvant chemotherapy (HR=0.188, 95% CI: 0.058-0.611), and recurrences (HR=10.855, 95% CI: 3.655-32.638) were independent prognostic factors for OS of invasive bladder cancer. Conclusion: Unresectable localized invasive bladder cancer can achieve satisfactory long-term outcomes with bladder-preserving combination therapy based on radiotherapy, most patients can retain normal bladder function with acceptable late adverse effects and improved survival particularly evident in patients with early, concurrent chemoradiotherapy and neoadjuvant chemotherapy.

[Construction and validation of a nomogram model of early related factors for hepatic insufficiency after hemihepatectomy].

Objectives: To investigate the early related factors for hepatic insufficiency after hemihepatectomy and to construct and validate a nomogram model. Methods: This was a retrospective cohort study.There were 207 patients with liver tumor who underwent hemihepatectomy in the Department of Hepatobiliary Surgery,Cancer Hospital,Chinese Academy of Medical Sciences from October 2016 to December 2022. Using the random number method,patients were randomly divided into a model group(n=166) and a validation group(n=41) according to an 4︰1 ratio. There were 118 males and 48 females in the modeling group,with an age (M(IQR)) of 59.0(13.3) years (range: 22.0 to 81.0 years),42 patients in the group with postoperative liver insufficiency and 124 patients in the group without postoperative liver insufficiency. There were 32 males and 9 females in the validation group, with an age of 54.0(19.0) years (rang: 25.0~81.0 years). The first results of the peripheral blood test of patients within 24 hours after surgery were collected,and the independent related factors for incomplete postoperative liver function were determined by multivariate Logistic regression analysis,and related factors of postoperative incomplete liver function were screened by best subset selection. A nomogram model of the risk of postoperative hepatic insufficiency after hemihepatectomy was constructed using R software,followed by internal and external validation of the model. Results: Multivariate logistic regression analysis showed that elevated D-dimer level and decreased antithrombin Ⅲ (AT-Ⅲ) activity within 24 hours after surgery were independent related factors for the development of postoperative hepatic insufficiency in hemihepatectomized patients. The results of the best subset selection showed that ALT,D-dimer, and AT-Ⅲ activity levels within 24 hours postoperatively were the most relevant factors for postoperative hepatic insufficiency. The R software was applied to build a nomogram prediction model based on the above three indicators in the model set,and the receiver operating characteristic(ROC) curve of the model showed an area under the curve of 0.803 and the calibration curve showed a U-index of -0.012 for the model(P=0.977). The results of the clinical decision analysis and the clinical impact curve indicated that the model had good clinical utility. The internal validation results of the Bootstrap method suggested that the model had reasonable consistency. The area under the ROC curve of the validation group model was 0.806,suggesting that the model had a good generalization prediction ability. Conclusions: The levels of ALT,D-dimer,and AT-Ⅲ activity within 24 hours after hemihepatectomy are valuable indicators for predicting liver insufficiency after hemihepatectomy. The nomogram model is reliable and can be used as an indicator for close postoperative monitoring.

[Effect of postoperative adjuvant chemotherapy on prognosis of patients with intrahepatic cholangiocarcinoma:a multicenter retrospective study].

Objectives: To examine the influence of adjuvant chemotherapy after radical resection on the survival of patients with intrahepatic cholangiocarcinoma(ICC) and to identify patients who may benefit from it. Methods: The clinical and pathological data of 654 patients with ICC diagnosed by postoperative pathology from December 2011 to December 2017 at 13 hospitals in China were collected retrospectively. According to the inclusion and exclusion criteria,455 patients were included in this study,including 69 patients (15.2%) who received adjuvant chemotherapy and 386 patients (84.8%) who did not receive adjuvant chemotherapy. There were 278 males and 177 females,with age of 59 (16) years (M(IQR))(range:23 to 88 years). Propensity score matching (PSM) method was used to balance the difference between adjuvant chemotherapy group and non-adjuvant chemotherapy group. Kaplan-Meier method was used to plot the survival curve,the Log-rank test was used to compare the difference of overall survival(OS) and recurrence free survival(RFS)between the two groups. Univariate analysis was used to determine prognostic factors for OS. Multivariate Cox proportional hazards models were then performed for prognostic factors with P<0.10 to identify potential independent risk factors. The study population were stratified by included study variables and the AJCC staging system,and a subgroup analysis was performed using the Kaplan-Meier method to explore the potential benefit subgroup population of adjuvant chemotherapy. Results: After 1∶1 PSM matching,69 patients were obtained in each group. There was no significant difference in baseline data between the two groups (all P>0.05). After PSM,Cox multivariate analysis showed that lymph node metastasis (HR=3.06,95%CI:1.52 to 6.16,P=0.039),width of resection margin (HR=0.56,95%CI:0.32 to 0.99,P=0.044) and adjuvant chemotherapy (HR=0.51,95%CI:0.29 to 0.91,P=0.022) were independent prognostic factors for OS. Kaplan-Meier analysis showed that the median OS time of adjuvant chemotherapy group was significantly longer than that of non-adjuvant chemotherapy group (P<0.05). There was no significant difference in RFS time between the adjuvant chemotherapy group and the non-adjuvant chemotherapy group (P>0.05). Subgroup analysis showed that,the OS of female patients,without HBV infection,carcinoembryonic antigen<9.6 µg/L,CA19-9≥200 U/ml,intraoperative bleeding<400 ml,tumor diameter>5 cm,microvascular invasion negative,without lymph node metastasis,and AJCC stage Ⅲ patients could benefit from adjuvant chemotherapy (all P<0.05). Conclusion: Adjuvant chemotherapy can prolong the OS of patients with ICC after radical resection,and patients with tumor diameter>5 cm,without lymph node metastasis,AJCC stage Ⅲ,and microvascular invasion negative are more likely to benefit from adjuvant chemotherapy.

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.

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.

[Stereotactic body radiation therapy for patients with lung and liver oligometastases from colorectal cancer: a phase â ¡ trial].

Objective: To explore the safety and effectiveness of stereotactic body radiation therapy (SBRT) for oligometastases from colorectal cancer (CRC). Methods: This is a prospective, single-arm phase Ⅱ trial. Patients who had histologically proven CRC, 1 to 5 detectable liver or lung metastatic lesions with maximum diameter of any metastases ≤5 cm were eligible. SBRT was delivered to all lesions. The primary endpoint was 3-year local control (LC). The secondary endpoints were treatment-related acute toxicities of grade 3 and above, 1-year and 3-year overall survival (OS) and progression free survival (PFS). Survival analysis was performed using the Kaplan-Meier method and Log rank test. Results: Petients from 2016 to 2019 who were treated in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Forty-eight patients with 60 lesions were enrolled, including 37 liver lesions and 23 lung lesions. Forty-six patients had 1 or 2 lesions, with median diameter of 1.3 cm, the median biologically effective dose (BED(10)) was 100.0 Gy. The median follow-up was 19.5 months for all lesions. Twenty-five lesions developed local failure, the median local progression free survival was 15 months. The 1-year LC, OS and PFS was 70.2% (95% CI, 63.7%~76.7%), 89.0% (95% CI, 84.3%~93.7%) and 40.4% (95%CI, 33.0%~47.8%). The univariate analysis revealed that planning target volume (PTV) and total dose were independent prognostic factors of LC (P<0.05). For liver and lung lesions, the 1-year LC, OS and PFS was 58.7% and 89.4% (P=0.015), 89.3% and 86.5% (P=0.732), 30.5% and 65.6% (P=0.024), respectively. No patients developed acute toxicity of grade 3 and above. Conclusion: SBRT is safe and effective treatment method for oligometastases from CRC under precise respiratory motion management and robust quality assurance.

[Status and related factors on the drinking behavior among primary and secondary students in China rural middle and western regions in 2019].

Objective: To analyze the daily drinking behavior and related factors of primary and middle school students in the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) pilot regions. Methods: Multi-stage stratified random cluster sampling method was used to select one to three national pilot counties in 22 provinces in central and western China where the NIPRCES was implemented in 2019. According to different feeding patterns, two primary schools and two middle schools were selected as key monitoring schools. One or two classes were selected from grade 3 to grade 9. The student questionnaire was used to collect the basic information and daily drinking behavior. Taking whether the drinking water ≥5 cups every day as the dependent variable, multivariate logistic regression model was used to analyze the related factors of drinking behavior among students. Results: A total of 27 374 students were included. On average, primary and middle school students in the regions where NIPRCES was implemented had 3.9 cups of water every day. Logistic regression model showed that boys (OR=1.230, P<0.001), primary school students (OR=1.379, P<0.001), father worked outside the home (OR=1.169, P<0.001), both parents worked outside the home (OR=1.228, P<0.001), non-resident students (OR=1.142, P<0.001), the school in the village (OR=1.638, P<0.001) or township (OR=1.358, P<0.001), school feeding (OR=1.252, P<0.001), the school building with flush toilets (OR=1.384, P<0.001) and the central regions (OR=1.300, P<0.001) students were more likely to drink ≥5 cups water every day. Conclusion: The water consumption of primary and middle school students in the pilot regions of NIPRCES is low, and their drinking behaviors are affected by many factors.

A New Berberine Preparation Protects Pancreatic Islet Cells from Apoptosis Mediated by Inhibition of Phospholipase A2/p38 MAPK Pathway.

We studied an amorphous solid dispersion of berberine with absorption enhancer sodium caprate (Huang-Gui solid dispersion preparations, HGSD). A therapeutic effect of HGSD was revealed in mice with type 2 diabetes mellitus and palmitate-induced injury to MIN6 ß-cells. HGSD treatment (150 mg/kg) improved glucose metabolism and decreased ß-cell apoptosis in diabetic mice. Furthermore, the effective component of HGSD berberine significantly attenuated the palmitate-induced decrease in MIN6 ß-cells viability and insulin secretion. Moreover, molecular docking analysis and Western blotting showed that berberine decreased cell apoptosis and expression of group VIA phospholipase A2 (iPLA2), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3. These data suggest that HGSD treatment protected ß-cells via inhibiting the iPLA2/p38 MAPK pathway.

[Comparison of follow-up treatment regimens for colorectal cancer liver metastases without objective response to neoadjuvant chemotherapy: direct surgery or surgery after second-line chemotherapy].

Objective: To compare the effect of direct surgery or surgery after second-line chemotherapy for colorectal cancer patients with liver metastases who did not achieve objective remission after neoadjuvant chemotherapy. Methods: A retrospective case cohort study was used. The clinical and pathological data of 107 patients with colorectal cancer liver metastases who did not achieve objective response to neoadjuvant chemotherapy at Department of Hepatobiliary Surgery,Cancer Hospital,Chinese Academy of Medical Sciences from December 2008 to December 2016 were retrospectively collected. There were 71 males and 36 females, median age was 57 years (range: 28 to 79 years). According to the different treatment regimens after neoadjuvant chemotherapy,107 cases were divided into a direct surgery group (direct group,n=65) and an operation after receiving second-line chemotherapy group (second-line group,n=42). The propensity score matching(PSM) of the Logistic regression model was used to match the bilobar distribution of liver metastases and the number of first-line chemotherapy cycles in the two groups of patients. The caliper value was set to 0.10 and the matching ratio was 1∶2. T test, Mann-Whitney U test, χ2 test or Fisher's exat test was used to analyzed the data between the tuo groups, respectively. Survival analysis design was used to investigate the difference in prognosis between the two groups of patients. Results: The follow-up time(M(IQR)) was 56.3(34.3) months (range: 2.1 to 95.0 months),and all patients were followed up. After PSM,there were 28 cases in the direct group and 42 cases in the second-line group, there were no significant differences in whether R0 resection was feasible,blood loss,blood transfusion,postoperative complications and postoperative hospital stay between the two groups (all P>0.05). The 1,3,and 5-year progression-free survival(PFS) rates of the direct group were 40.0%,16.5%,and 11.0%,and the 1,3,and 5-year overall survival(OS) rates were 98.5%,61.2%,and 41.4%,respectively, the second-line group 1,3,5 years PFS rates were 35.7%,14.3%,14.3%,1,3,5-year OS rate were 95.2%,55.1%,44.4%,respectively. The median PFS time of the direct group and the second-line group was 8.5 months and 7.5 months,respectively,and the difference was not statistically significant (P=0.826). The median OS time of the direct group and the second-line group were 33.8 months and 46.9 months,respectively. The difference was not statistically significant(P=0.646).The median PFS time of the direct group and second-line chemotherapy complete remission and partial remission group(CR/PR group) was 10.2 months and 9.1 months,respectively,and the difference was not statistically significant(P=0.669). The median OS time of the direct group and the second-line CR/PR group was 51.0 months and 46.9 months,respectively,and the difference was not statistically significant(P=0.427). The results of survival analysis suggested that major liver resection was an independent prognosis factor for PFS (HR=1.809,95%CI: 1.067 to 3.067,P=0.028) and OS(HR=2.751,95%CI: 1.317 to 5.747,P=0.007). Second-line chemotherapy was not an independent prognostic factor for PFS (HR=0.945, 95%CI:0.570 to 1.567,P=0.828) and OS (HR=0.866,95%CI: 0.468 to 1.602,P=0.646). Conclusions: There is no significant difference in the short-term outcome and long-term prognosis between direct surgery patients and second-line chemotherapy followed by surgery. Second-line chemotherapy is not an independent prognostic factor for colorectal cancer liver metastases patients who fail to achieve objective response after neoadjuvant chemotherapy.

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.

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.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission.

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

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.