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.

Relationships between diabetic nephropathy and insulin resistance, inflammation, Trx, Txnip, CysC and serum complement levels

OBJECTIVE

To investigate the relationships between diabetic nephropathy (DN) and insulin resistance, inflammation, thioredoxin (Trx), thioredoxin-interacting protein (Txnip), Cystatin C (CysC) and serum complement levels.

PATIENTS AND METHODS

A total of 119 patients with type 2 diabetes mellitus (T2DM) treated in the Endocrinology Department of our hospital from January 2017 to December 2017 were enrolled as the experiment group, while 30 healthy volunteers were selected as the control group. The expression levels of inflammatory factors, Trx, Txnip, CysC and serum complements in every subject were detected. In addition, the type 2 diabetic nephropathy rat model was established via high-fat diet and injection of low-dose streptozotocin. Blood glucose, insulin resistance indexes and 24h-urinary albumin excretion were measured, and the histomorphological characteristics of the kidney in animals were observed.

RESULTS

In clinical subjects, Trx level was notably lower in the simple DM group, early DN group and clinical DN group in comparison with that in the control group. The levels of Txnip and CysC in the simple DM group, early DN group and clinical DN group were remarkably higher than those in the control group. Moreover, the expression levels of TNF-α and IL-6 in the clinical DN group were significantly elevated compared with those in the simple DM group and early DN group. In addition, C1q expression in the clinical DN group was higher than that in the simple DM group and early DN group. In model rats, HOMA-IR was distinctly higher in the DM group and DN group than that in the control group. The ratio of kidney weight to body weight (KW/BW) was evidently higher in the DN group in comparison with that in the control group and DM group.

CONCLUSIONS

Insulin resistance, inflammatory factors, and levels of Trx, Txnip, CysC and serum complement C1q are related to the progression of DM.

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.

[Risk factors of blood loss during liver transplantation in children with biliary atresia and its influence on prognosis]

Objectives: To study the risk factors for massive intraoperative blood loss in children with biliary atresia who underwent liver transplantation for the first time,and to analyze their impacts on graft survival,hospital stay and postoperative complications. Methods: The data of 613 children with biliary atresia who underwent liver transplantation at Department of Pediatric Organ Transplantation,Tianjin First Central Hospital from January 2015 to December 2018 were collected and analyzed. There were 270 males and 343 females, aged 7.4 (3.9) months (range: 3.2 to 148.4 months), the body weight of the recipients were (7.8±3.5) kg (range: 4.0 to 43.3 kg).According to the 85^th quad of estimated blood loss(EBL),they were divided into two groups:massive EBL group(96 cases) and non massive EBL group(517 cases). The age,height,weight and other factors between the two groups were analyzed and compared. Univariate Logistic regression and multiple stepwise regression were used to determine the risk factors of massive EBL. Then,the postoperative complications of the two groups,including portal vein thrombosis and portal vein anastomotic stenosis etc.,were analyzed and compared by chi square test. Kaplan Meier curve and log rank test were used to analyze the recipient and graft survival rate of the two groups. Results: During the study period,713 transplants were performed and 613 patients were enrolled in the study. Ninety-six patients(15.7%) had massive EBL,and the postoperative hospital stay was 21(16) days(range:2 to 116 days),the hospital stay of non-massive EBL group was 22(12)days(range:3 to 138 days)(U=24 224.0,P=0.32). Univariate Logistic regression analysis showed that the recipient's weight,Kasai portoenterostomy,platelet count,operation time and cold ischemia time were the risk factors of massive EBL during biliary atresia transplantation. Multiple regression analysis showed that cold ischemia time ≥10 hours,prolonged operation time(≥8 hours) and body weight<5.5 kg were important independent risk factors for massive EBL.The incidence of portal vein thrombosis,hepatic vein stenosis,intestinal leakage and pulmonary infection in patients with massive EBL were significantly higher than those without massive EBL(3.1% vs. 0.8%,9.4% vs. 2.1%,6.3% vs. 0.8%,30.2% vs. 20.1%,all P<0.05). The 3-year overall graft and recipient survival rate were significantly lower in patients with massive EBL than those without massive EBL(87.5% vs. 95.7%,P=0.001;84.4% vs. 95.4%,P<0.01,respectively). Conclusions: In children with biliary atresia who underwent liver transplantation for the first time,the effective control of intraoperative bleeding should shorten the operation time and reduce the cold ischemia time as far as possible,on the premise of ensuring the safety of operation. For children without growth disorder,the weight of children should be increased to more than 5.5 kg as far as possible to receive the operation. Reducing intraoperative bleeding is of great significance to the prognosis of children.

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.

Oxidized low-density lipoprotein stimulates dendritic cells maturation via LOX-1-mediated MAPK/NF-κB pathway

Dendritic cells (DCs) play a crucial role as central orchestrators of immune system response in atherosclerosis initiation and progression. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is involved in the immune maturation of DCs, but the underlying mechanisms remain unclear. We isolated mouse bone marrow progenitors and stimulated them with granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4 to induce immature DCs. We then treated DCs with oxidized low-density lipoprotein (oxLDL) to induce maturation. LOX-1 siRNA was used to investigate the modulation of LOX-1 on the development of DCs and the underlying signal pathways. CD11c-positive DCs were successfully derived from mouse bone marrow progenitors. OxLDL promoted the expressions of DCs maturation markers and pro-inflammatory cytokines. OxLDL also upregulated LOX-1 expression and activated MAPK/NF-κB pathways. LOX-1 siRNA could attenuate the expression of MAPK/NF-κB pathways and inflammatory cytokines. In conclusion, oxLDL induced the maturation of DCs via LOX-1-mediated MAPK/NF-κB pathway, which contributed to the initiation and progression of atherosclerosis.

MiRNA-488-3p inhibits malignant progression of NSCLC by modulating ADAM9

OBJECTIVE

The purpose of this study was to investigate the role of microRNA-488-3p in the proliferation, invasion and migration of lung cancer cells and to further explore the potential regulatory mechanisms.

PATIENTS AND METHODS

MicroRNA-488-3p expression in 46 pairs of tumor tissue and paracancerous tissue specimens collected from non-small cell lung cancer (NSCLC) patients were measured through quantitative real-time polymerase chain reaction (qRT-PCR) method, and the interplay between microRNA-488-3p expression and some clinical indicators of these subjects was also analyzed. In addition, microRNA-488-3p overexpression models were constructed in NSCLC cell lines, and then Cell Counting Kit-8 (CCK-8) test and transwell assays were carried out to evaluate the effect of microRNA-488-3p on the NSCLC cell functions. Furthermore, bioinformatics analysis and luciferase reporter gene assay were carried out to uncover the potential interaction between microRNA-488-3p and its downstream gene ADAM9.

RESULTS

QPCR results revealed that microRNA-488-3p showed a significant lower expression in NSCLC tissue samples than in adjacent normal ones. In comparison to patients with high expression of microRNA-488-3, patients with low expression of microRNA-488-3 exhibited higher incidence of lymph node or distant metastasis and lower survival rate. In vitro cell experiments showed that, in comparison to control group, overexpression of microRNA-488-3p significantly weakened the proliferation ability as well as the invasion and migration of NSCLC cells. Subsequently, a significant increase in ADAM9 expression in NSCLC tissue samples was found, which indicated its negative correlation with microRNA-488-3p. In addition, cell recovery experiment demonstrated that overexpression of ADAM9 could counteract the impact of microRNA-488-3p upregulation on the proliferation and invasion ability of NSCLC cells, and the two may thus together affect the malignant progression of NSCLC.

CONCLUSIONS

It can be concluded that microRNA-488-3p, which is associated with the incidence of metastasis in NSCLC patients, can inhibit the malignant progression of NSCLC cells by modulating ADAM9 expression.

Personalized drug testing in a patient with non-small-cell lung cancer using cultured cancer cells from pleural effusion

Objective

Patients with non-small-cell lung cancer (NSCLC) and primary or acquired resistance do not respond to targeted drugs. We explored whether cancer cells can be cultured from liquid biopsies from patients with primary resistance to tyrosine kinase inhibitors (TKIs). We aimed to predict patients’ responses to drugs according to in vitro drug testing results.

Methods

Cancer cell cultures were established from the pleural effusion of a patient with TKI-resistant NSCLC using a conditional reprogramming technique. Phenotypic drug sensitivity tests were performed using the Cell Counting Kit-8 assay. We tested individual drugs and compared the synergistic and inhibitory effects of drug combinations.

Results

The results of our in vitro sensitivity test using the combination of cisplatin and pemetrexed were correlated with the patient’s response.

Conclusion

This represents the first successful report of predictive testing for combination therapy in patients with epidermal growth factor receptor-mutant NSCLC and primary TKI resistance. This strategy should be applicable to both chemotherapies and targeted therapies, and it will significantly improve the clinical treatment and management of patients with NSCLC and primary or acquired resistance to targeted therapies, as well as patients lacking targetable mutations.

[Initial exploration of transfusion-free liver transplantation]

Objective: To evaluate the effect of transfusion-free techniques on the prognosis of liver transplant patients. Methods: The recipients of adult liver transplantation at Tianjin First Central Hospital from August to December 2019 were included in the clinical observation. Liver transplantation without allogeneic blood transfusion was performed through anesthesia management techniques such as acute hemodilution or phlebotomy without volume replacement,maintaining decreased baseline central venous pressure and cell saver. According to the actual results,the patients were divided into two groups: transfusion-free group(n=21) and allogeneic transfusion group(n=28). There were 13 males and 8 females aged of (56.3±11.6) years in the transfusion-free group;and there were 16 males and 12 females aged (54.3±14.2)years in the allogeneic transfusion group. The transplant recipients who had not adopted transfusion management strategy from January to July 2019 were included as control group(27 males and 13 females,aged of (58.9±14.1)years). The clinical data of patients in perioperative period were collected to compare whether there were differences in the recovery of liver function and early complications among the three groups, one-way ANOVA test, rank-sum test, and χ² test were used for data analysis. Results: The amount of intraoperative blood loss in both the transfusion-free group and the transfusion group was less than that in the control group((454.2±271.3)ml vs.(673.6±333.4)ml vs.(890.3±346.7)ml;q=-6.342,-5.286,both P<0.05).The duration of stay in ICU of the transfusion-free group was less than that of the transfusion group and control group((36.4±9.1)hours vs.(44.3±14.9)hours vs.(58.2±21.1)hours;q=-4.432,-3.824,both P<0.05).The mean ALT level at 7 days after operation was significantly lower in the transfusion-free group than in the control group((56.8±32.1)U/L vs.(89.6±45.6)U/L;q=-3.358,P<0.05). Conclusions: The improvement of multi-disciplinary transfusion management technology aimed at transfusion-free liver transplantation can effectively reduce intraoperative hemorrhage and help to avoid surgical transfusion. Transfusion-free liver transplantation is beneficial to the early postoperative recovery,and its long-term clinical significance is worthy of further clinical research.

Effect of heat input on interfacial characterization of the butter joint of hot-rolling CP-Ti/Q235 bimetallic sheets by Laser + CMT

Composite structures made of 2 mm-thick titanium and 10 mm-thick carbon steel are widely used in infrastructures such as long-distance gas transportation. However, cracking, which is caused by intermetallic compounds (ICs), is a dominate failure mode in welds of this structure. Thus, a common way to improve the in-service life of is reduce the number of ICs. In this paper, we employ a novel hybrid welding method to fabricate composite structures of TA₂ titanium and Q235 carbon steel. Specifically, Ti and carbon steel is welded by laser and double Cold Metal Transfer (CMT) welding, respectively. The microstructure near the interface of Ti and steel is then examined using SEM, EBSD, EDS, with emphasis on the ICs in terms of chemical elements and morphologies. Results show that FeTi and Fe₂Ti are the main ICs near the interface, and responsible for the failure of the welds. The effect of welding heat input on the formation of ICs is investigated as well. Results show that ICs are smaller when the heat input is low. Under low heat input circumstance, the tensile strength of the weld can reach up to 420 MPa.

Thyroid hormone concentrations in severely or critically ill patients with COVID-19

OBJECTIVE

COVID-19 is a new coronavirus infectious disease. We aimed to study the characteristics of thyroid hormone levels in patients with COVID-19 and to explore whether thyroid hormone predicts all-cause mortality of severely or critically ill patients.

METHODS

The clinical data of 100 patients with COVID-19, who were admitted to Wuhan Tongji Hospital from February 8 to March 8, 2020, were analyzed in this retrospective study. The patients were followed up for 6-41 days. Patients were grouped into non-severe illness and severe or critical illness, which included survivors and non-survivors. Multivariate Cox proportional hazards analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality in association with continuous and the lower two quartiles of thyroid hormone concentrations in severely or critically ill patients.

RESULTS

The means of free T3 (FT3) were 4.40, 3.73 and 2.76 pmol/L in non-severely ill patients, survivors and non-survivors, respectively. The lower (versus upper) two quartiles of FT3 was associated with all-cause mortality HR (95% CI) of 9.23 (2.01, 42.28). The HR (95% CI) for all-cause mortality in association with continuous FT3 concentration was 0.41 (0.21, 0.81). In the multivariate-adjusted models, free T4 (FT4), TSH and FT3/FT4 were not significantly related to all-cause mortality. Patients with FT3 less than 3.10 pmol/L had increased all-cause mortality.

CONCLUSION

FT3 concentration was significantly lower in patients with severe COVID-19 than in non-severely ill patients. Reduced FT3 independently predicted all-cause mortality of patients with severe COVID-19.

Smoking and HIV associated with subclinical tuberculosis: analysis of a population-based prevalence survey

BACKGROUND: Despite multiple tuberculosis (TB) prevalence surveys reporting a relatively high frequency of bacteriologically confirmed, active TB among individuals reporting no typical symptoms of disease, our understanding of this phenomenon is limited.OBJECTIVE: To quantify the epidemiological burden and estimate associations between individual-level variables and this "subclinical" presentation.METHODS: We performed a secondary analysis of TB prevalence survey data from the South African communities of the Zambia, South Africa Tuberculosis and AIDS Reduction trial. Generalized estimating equations were used to estimate the association between individual-level demographic, behavioral, socio-economic, and medical variables and the risk of bacteriologically positive TB among participants not reporting any symptoms consistent with active TB.RESULTS: The crude prevalence of TB was 2222.1 cases per 100 000 population (95% CI 2053.4-2388.5); 44.7% (295/660) of all documented prevalent cases of TB were subclinical. Current tobacco smoking (OR 2.37, 95% CI 1.41-3.99) and HIV-positive status (OR 3.26, 95% CI 2.31-4.61) were significantly associated with subclinical TB.CONCLUSION: Individuals who smoke or have HIV may be at increased risk of active TB and not report typical symptoms consistent with disease. This suggests possible shortcomings of symptom-based case finding which may need to be addressed in similar settings.

[Analysis for the breast cancer screening among urban population in Hebei province, 2018-2019]

From 2018 to 2019, 3 453 cases of high-risk population were screened by the Cancer Screening Program in Urban China (CanSPUC) in Hebei Province, with the age of (53.94±8.00). 147 and 686 cases of breast cancer positive and suspicious positive patients were found, with the positive rate and suspicious positive rate of 4.26% and 19.87% respectively. The suspicious positive rate of 45-49 years old age group was the highest (28.32%), and the positive rate of over 70 years old age group was the highest (7.32%). The positive detection rate of mammography combined with ultrasound was 5.16%, which was higher than that of ultrasound alone (2.46%) (χ²=30.28,P<0.001) or mammography alone (3.06%) (χ²=14.56,P<0.001).

Acute care utilisation towards the end of life and the place of death for patients with serious mental disorders: a register-based cohort study in South London

OBJECTIVES

The aim of the study was to explore acute care utilisation towards end of life by and the place of death for patients with serious mental disorders and to demonstrate any inequalities in end-of-life care faced by this patient group.

STUDY DESIGN

This is a retrospective cohort study using linked, routinely collected data.

METHODS

This study used linked data extracted from mental health records, Hospital Episode Statistics and mortality data. Adult cases (≥18 years old) were included if they had a serious mental disorder and died between 2007 and 2015. Multiple imputation was used to manage missing data, and generalised linear models were used to assess multiple adjusted associations between sociodemographic and clinical explanatory variables and acute service use at the end of life and in-hospital deaths.

RESULTS

A cohort of 1350 adults was analysed. More than half visited the accident and emergency (A&E) department in the last 90 days of life, and a third had a burdensome transition (multiple hospital admissions in the last 90 days of life or at least one in the last three days); the median number of days spent in the hospital was 4 (range: 0-86). Having more comorbidities was a strong correlate of more A&E visits (adjusted odds ratio [OR] = 1.03 [95% confidence interval = 1.02-1.04]), burdensome transitions (adjusted OR = 1.06 [1.04-1.08]) and days spent in the hospital (adjusted OR = 1.04 [1.03-1.05]). Having a diagnosis of schizophrenia spectrum disorder, compared with other serious mental disorder diagnoses, was associated with fewer A&E visits (adjusted OR = 0.78 [0.71-0.88]) and fewer days in the hospital (adjusted OR = 0.77 [0.66-0.89]). Younger age was associated with more A&E visits (adjusted OR = 1.28 [1.07-1.53]) and fewer days spent in the hospital (adjusted OR = 0.70 [0.52-0.95]). Hospital deaths were high (51%), and in a fully adjusted model, they were associated with having more comorbidities (adjusted OR = 1.02 [1.01-1.03]) and accessing acute care at the end of life (including more A&E visits; adjusted OR = 1.07 [1.05-1.10]), burdensome transitions (adjusted OR = 1.53 [1.37-1.71]) and days spent in the hospital (adjusted OR = 2.05 [1.70-247]).

CONCLUSION

People with comorbidities are more likely to use more burdensome acute health care at the end of life and are more likely to die in the hospital. Hospital deaths could be reduced, and end-of-life care could be improved by targeting patients with comorbidities and who are accessing more acute healthcare services.

Effects of oral sialic acid on gut development, liver function and gut microbiota in mice

Sialic acid (N-acetylneuraminic acid), a 9-carbon monosaccharide, has been widely studied in immunology, oncology and neurology. However, the effects of sialic acid on organ and intestinal development, liver function and gut microbiota were rarely studied. In this study, we found that oral sialic acid tended to increase the relative weight of liver and decreased the serum aspartate aminotransferase (GPT) activity. In addition, sialic acid treatment markedly reduced gut villus length, depth, the ratio of villus length/depth (L/D), areas, width and the number of goblet cells. Furthermore, gut microbes were changed in response to oral sialic acid, such as Staphylococcus lentus, Corynebacterium stationis, Corynebacterium urealyticum, Jeotgalibaca sp_PTS2502, Ignatzschineria indica, Sporosarcina pasteurii, Sporosarcina sp_HW10C2, Facklamia tabacinasalis, Oblitimonas alkaliphila, Erysipelatoclostridium ramosum, Blautia sp_YL58, Bacteroids thetaiotaomicron, Morganella morganii, Clostridioides difficile, Helicobacter tryphlonius, Clostridium sp_Clone47, Alistipes finegoldii, [pseudomonas]_geniculata and Pseudomonas parafulva at the species level. In conclusion, oral sialic acid altered the intestinal pathological state and microbial compositions, and the effect of sialic acid on host health should be further studied.

Effect of self-control on health promotion behavior in patients with coronary heart disease: mediating effect of ego-depletion

The present study used a cross-sectional survey design to explore the role of ego-depletion in the relationship between self-control and health-promoting behaviors in patients with coronary heart disease (CHD). This study recruited 277 patients with CHD to measure the levels of ego-depletion, self-control and health-promotion (HP) behavior using Self-Regulatory Fatigue Scale (SRF-s), Dual-Mode of Self-Control Scale (DMSD-s) and Health Promotion Lifestyle Profile-II (HPLP-II) to examine the relationship between the three. Study found that self-control improved the patients' HP behaviors to some extent. Self-control in patients with CHD uses ego-depletion as the mediating variable to indirectly and positively predict the level of HP behavior, and the mediating effects account for 47.76% (impulsive system) and 15.6% (control system) of the total effects, respectively.