Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Integrating transcriptome-wide association study and mRNA expression profiling identifies novel genes associated with bone mineral density

To scan novel candidate genes associated with osteoporosis, a two-stage transcriptome-wide association study (TWAS) of bone mineral density (BMD) was conducted. The BMD-associated genes identified by TWAS were then compared with the gene expression profiling of BMD in bone cells, B cells, and mesenchymal stem cells. We identified multiple candidate genes and gene ontology (GO) terms associated with BMD.

INTRODUCTION

Osteoporosis (OP) is a metabolic bone disease characterized by decrease in BMD. Our objective is to scan novel candidate genes associated with OP.

METHODS

A transcriptome-wide association study (TWAS) was performed by integrating the genome-wide association study (GWAS) summary of bone mineral density (BMD) with two pre-computed mRNA expression weights of peripheral blood and muscle skeleton. Then, another independent GWAS data of BMD was used to verify the discovery results. The BMD-associated genes identified between discovery and replicate TWAS were further subjected to gene ontology (GO) analysis implemented by DAVID. Finally, the BMD-associated genes and GO terms were further compared with the mRNA expression profiling results of BMD to detect the common genes and GO terms shared by both DNA-level TWAS and mRNA expression profile analysis.

RESULTS

TWAS identified 95 common genes with permutation P value < 0.05 for peripheral blood and muscle skeleton, such as TMTC4 in muscle skeleton and DDX17 in peripheral blood. Further comparing the genes detected by discovery-replicate TWAS with the differentially expressed genes identified by mRNA expression profiling of OP patients found 18 overlapped genes, such as MUL1 in muscle skeleton and SPTBN1 in peripheral blood. GO analysis of the genes identified by discovery-replicate TWAS detected 12 BMD-associated GO terms, such as negative regulation of cell growth and regulation of glycogen catabolic process. Further comparing the GO results of discovery-replicate TWAS and mRNA expression profiles found 6 overlapped GO terms, such as membrane and cell adhesion.

CONCLUSION

Our study identified multiple candidate genes and GO terms for BMD, providing novel clues for understanding the genetic mechanism of OP.

The applied anatomy and clinical significance of the proximal, V1 segment of vertebral artery

BACKGROUND

The aim of the study was to probe the morphological features of the proximal segment (V1) of vertebral artery (VA) in a sample of Chinese cadavers.

MATERIALS AND METHODS

The origin, course and outer diameter at origin of the pre-vertebral part of the VAs were evaluated in 119 adult cadavers.

RESULTS

It was found that 94.12% of the VAs originated from the subclavian arteries, bilaterally. The variant origins were present in 5.88% of the cadavers and all originated directly from the arch of the aorta. All the variations were observed on the left side of male cadavers. The average outer diameters at origin of the normal and variation groups were 4.35 ± 1.00 mm and 4.82 ± ± 1.42 mm, respectively, p = 0.035. In the normal group, but not in the variation group, the average diameter in the males was significantly larger than that in the females (4.50 ± 0.99 mm, 3.92 ± 0.92 mm, respectively, p = 0.000). In addition, only 5 cadavers in the normal group had hypoplastic VAs (4.20%, 4 males, 3 right-sided). Vertebral artery dominance (VAD) was present in 91 (69 males) out of 112 cadavers and more common on the left (n = 48). In addition, 3 cadavers satisfied conditions for coexistence of VAD and vertebral artery hypoplasia. All 7 cadavers in the variation group exhibited VAD, which was more common on the right side (n = 5).

CONCLUSIONS

The morphologic variations and frequencies described above have implications for the early prevention, abnormal anatomy detection, accurate diagnosis, safe surgery and endovascular treatment of cardiovascular and neurological disease.

The potential of cadmium ion-immobilized Rhizobium pusense KG2 to prevent soybean root from absorbing cadmium in cadmium-contaminated soil

AIMS

Because the effect of Cd2+ -immobilized microbe on Cd uptake of plants in Cd-contaminated soil remains underexplored, this study focuses on the effect of Cd2+ -immobilized rhizobia on Cd uptake of soybean.

METHODS AND RESULTS

Strain KG2 from soybean nodule was identified as Rhizobium pusense KG2 by phylogenetic analysis. Rhizobium pusense KG2 showed the 120 mg l-1 of minimal lethal concentration for Cd2+ . In 50 and 100 mg l-1 of Cd2+ liquid, approximately 2 × 1010 cells removed 56·71 and 22·11% of Cd2+ , respectively. In pot soil containing 50 and 100 mg kg-1 of Cd2+ , strain KG2 caused a 45·9 and 35·3% decrease in soybean root Cd content, respectively. Meanwhile, KG2 improved the root and shoot length, nitrogen content and biomass of soybean plants and superoxide dismutase activity.

CONCLUSIONS

The Cd2+ -immobilized rhizobia could inhibit soybean plants to absorb Cd2+ from soil, promote plant growth and improve plant's tolerance against Cd. This study is the first time to report that R. pusense is an effective nodulating rhizobium of legume.

SIGNIFICANCE AND IMPACT OF THE STUDY

Some Cd2+ -immobilized microbe lowering Cd uptake of plant and promoting plant growth should be considered as an effective strategy for producing safety crops in the Cd-contaminated agricultural soil.

[Clinical significance of exosomal miR-1231 in pancreatic cancer]

Objective: To investigate the expression and clinical significance of exosomal miR-1231 in plasma of pancreatic cancer (PC) patients and pancreatic cancer cells. Methods: A total of 16 patients who were diagnosed with pancreatic cancer in Hunan Cancer Hospital were collected from April 2016 to August 2017. Meanwhile, 16 healthy volunteers were recruited as the healthy control group at the same period. The plasma exosomes were extracted, and the levels of miR-1231 were detected by qRT-PCR in PC and healthy control groups. Moreover, the clinicopathological significance of exosomal miR-1231 expression was analyzed. Furthermore, the expression of exosomal miR-1231 was detected in several pancreatic cancer cells (MIA PaCa-2, PANC-1, SW1990, AsPC-1 and BxPc-3) and two normal pancreatic epithelial cells (HPDE and human primary pancreatic epithelial cell). Results: qRT-PCR results showed that the expression level of miR-1231 in plasma exosomes of pancreatic cancer patients (1.06±0.46) was significantly lower than that in healthy controls (2.30±0.99; P<0.05). The levels of exosomal miR-1231 in patients with stage Ⅰ-Ⅱ (1.515±0.531), no distant metastasis (1.236±0.461) and no lymph node metastasis (1.337±0.522) were significantly higher than those with stage Ⅲ-Ⅳ (0.848±0.224), distant metastasis (0.757±0.278) and lymph node metastasis (0.838±0.261), respectively (P<0.05 for all). In addition, there were no correlation between exosomal miR-1231 expression and age, sex, smoking history, CA19-9 levels and tumor sites (P>0.05). Furthermore, the expression level of exosomal miR-1231 in pancreatic cancer cell lines (0.142±0.135) was significantly lower than that in normal epithelial cells (1.127±0.179; P<0.05). Conclusions: The downregulation of exosomal miR-1231 in plasma of pancreatic cancer patients and pancreatic cancer cells suggests that it is related to the initiation and development of PC. It may be a new diagnostic and prognostic marker for PC.

Negative Association of Serum URIC Acid with Peripheral Blood Cellular Aging Markers

OBJECTIVES

We aimed to explore the association between serum UA and cellular aging markers.

DESIGN

The current cross-sectional analysis was based on data collected within a type 2 diabetes project.

SETTINGS

Serum uric acid (UA), which has both antioxidant and pro-oxidant properties, is thought to be involved in cellular aging processes.

PARTICIPANTS

There are 536 participants included in total, 65.3% of which are women. The average serum UA in women was 267.8 umol/l, lower than in men of 337.7 umol/l (P<0.001).

MEASUREMENTS

Serum UA, blood lipid profile, HbA1c, plasma glucose and insulin were determined. The peripheral blood leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn) were assessed using a real-time PCR assay. Logistic regressions were used to analyze the associations between serum UA and cellular aging markers.

RESULTS

In Spearman's correlation analysis, there were significantly negative correlations between serum UA and LTL in both women and men (r=-0.162, P=0.006; and r=-0.232, P=0.004, respectively). The logistic regression adjusted for age, BMI, WC, daily energy intake, HbA1c, TG, and LDL-C revealed that the ORs of shorter LTL comparing the extreme serum UA quintiles was 5.52 (95% CI 1.69-18.02; P for trend =0.025) in women and 6.49 (95% CI 1.38-30.45; P for trend =0.108) in men. Furthermore, the OR (95% CI) for shorter LTL per 1 SD increment in serum UA was 1.51(1.10-2.07) in women and 1.64(1.01-2.65) in men. In regard to mtDNAcn, the association between elevated serum UA and lower mtDNAcn only reached significance in men when comparing the second and fifth quintiles with reference quintile (OR=3.73(1.07-13.04) and 3.76(1.01-14.09) , separately, and P for trend=0.066).

CONCLUSIONS

Our results indicate a significant negative association between serum UA and peripheral blood cellular aging markers. Serum UA might play a role in promoting cellular aging.

[Effect of enteral nutrition on accidental upper gastrointestinal injury in children]

Objective: To evaluate the effectiveness of enteral nutrition in children with accidental upper gastrointestinal injury. Methods: The medical records of 128 patients with mechanical or chemical gastrointestinal mucosal injury, who were hospitalized in Department of Gastroenterology, Children's Hospital of Zhejiang University School of Medicine from January 1, 2011 to December 30, 2017, were collected. All cases were treated with enteral nutrition. The clinical features and etiologies were retrospectively analyzed. Weight-for-age Z score and lab findings including white blood cells, C-reactive protein, neutrophils, albumin, prealbumin, urea nitrogen and hemoglobin before and after treatment were extracted. The clinical characteristics, the duration of enteral nutrition and gastrointestinal mucosal healing between different etiologies were further analyzed. Normal distribution variables and categorized variables were compared with t test and χ(2) test respectively, and abnormal distribution data was compared with Wilcoxon test. Results: Among all the cases, 77 were males and 51 were females. The average age was (29±22) months. The mean duration of hospitalization and enteral nutrition were (11±7)d and (27±20)d respectively. Vomiting was the most common clinical presentation (72 cases, 56.3%). In 79 cases the problems were caused by mechanical injury, among which coins were most commonly seen. The rest 49 cases were caused by chemical injury. However, the duration of hospitalization ((13±8) d vs. (10±6)d, t=-3.089, P=0.002) and enteral nutrition ((39±22) vs. (19±14) d, t=-5.365, P=0.000) were longer in children with chemical injury than those with mechanical injury. A total of 112 cases got complete blood count and C-reactive protein both before and after enteral nutrition. Inflammatory markers, including leukocytes ((7.7±2.7) ×10(9)/L vs. (13.7±5.0) ×10(9)/L, t=12.244, P <0.05), neutrophils ((3.4±1.9)×10(9)/L vs. (9.4±4.6) ×10(9)/L, t=13.655, P<0.05), and C-reactive proteins (5.0(3.0,7.8) vs. 13.5(6.0,40.5) mg/L, Z=7.776, P <0.05) were significantly decreased. The nutritional markers, including the weight-for-age z score (-0.1 ± 1.0 vs. 0.0 ± 1.0, t=-2.622, P=0.010) and the prealbumin (0.1 ± 0.1 vs. 0.2 ± 0.0 g/L, t=-3.671, P=0.001) were significantly increased. Fifty-five (82.1%) children in mechanical injury group recovered in 4 weeks, while 27 (79.4%) children in chemical injury group recovered in 7 weeks. Conclusion: Enteral nutrition can provide adequate nutritional requirements for children with upper gastrointestinal injury, and may help to decrease imflammation and improve mucosal healing.

Cell-bound complement activation products (CB-CAPs) have high sensitivity and specificity in pediatric-onset systemic lupus erythematosus and correlate with disease activity

OBJECTIVE

Elevated levels of cell-bound complement activation products (CB-CAPs) (C4d deposition on B lymphocytes (BC4d) and/or erythrocytes (EC4d)) are sensitive and specific in diagnosis and monitoring of adult systemic lupus erythematosus (SLE). Our objective was to evaluate the role of CB-CAPs for diagnosis and monitoring of pediatric-onset SLE (pSLE).

METHODS

A prospective cohort study of 28 pSLE and 22 juvenile arthritis patients was conducted. SLE disease activity was determined using a clinical Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) that excluded serologies. Autoantibodies were measured using solid-phase immunoassays, C3 and C4 using immunoturbidimetry, and CB-CAPs using quantitative flow cytometry. Abnormal CB-CAPs were defined as EC4d or BC4d above the 99th percentile for healthy adults (>14 and > 60 net mean fluorescence intensity (MFI), respectively). Performance characteristics of CB-CAPs were assessed using area under the curve (AUC) for receiver operating characteristics. Linear mixed effect models evaluated the correlation between CB-CAPs and clinical SLEDAI over 6 months.

RESULTS

BC4d yielded higher AUC (0.91 ± 0.04) than C3 (0.63 ± 0.08) and C4 (0.67 ± 0.08) ( p < 0.05). Abnormal CB-CAPs were 78% sensitive and 86% specific for diagnosis of pSLE (Youden's index = 0.64 ± 0.11). In contrast to BC4d, EC4d levels correlated with clinical SLEDAI ( p < 0.01).

CONCLUSION

CB-CAPs (EC4d and BC4d) have higher sensitivity and specificity than low complement in pSLE, and may help with diagnosis of pSLE. EC4d could provide a useful biomarker for disease activity monitoring.

Highly efficient extraction and purification of low-density lipoprotein from hen egg yolk

Low-density lipoprotein (LDL) from hen egg yolk has high nutritional value and plays an important role in the fields of biology, medicine, and materials. To develop fundamental research about LDL, a highly efficient extraction method is necessary. We found that 30% saturated ammonium sulfate can extract more crude LDL than 40% saturation. We selected polyethylene glycol (PEG; nonionic type) to obtain crude LDL. Three factors were employed, namely, degree of polymerization, concentration of PEG, and pH of egg yolk plasma. The optimized condition was 5% PEG 4,000 and plasma pH 6.0, and the best extraction efficiency was 68.1 ± 0.5 g lipid /100 g DM and 69.9 ± 2.0% protein. The crude LDL oil of PEG precipitation was very significantly higher (P < 0.01) than ammonium sulfate precipitation (ASP), while there was no significant difference in protein, which indicates that PEG can extract more crude LDL. When ascorbic acid was added, hydrosulfuryl (SH) groups and lipids oxidation degree of crude LDL extracted by PEG (PEG-LDL) was very significantly lower than ASP (P < 0.01). We also obtained both purified LDL and yolk immunoglobulin (IgY) with an appropriate purification column. This paper proposes a highly efficient method to extract LDL with high activity using PEG and ensures co-purification of LDL and IgY.

Protective effects of Herpetospermum caudigerum extracts against liver injury induced by carbon tetrachloride in mouse

Herpetospermum caudigerum (H. caudigerum; HC), popularly known as “Sejimeiduo” in Tibet, it is widely used in Tibetan traditional medicine for the treatment of dyspepsia, liver and colic diseases. This study was designed to evaluate the effect of H. caudigerum extract (HCE) on suppressing liver injury induced by carbon tetra chloride (CCl4). For this purpose, we used CCl4 to induce acute liver injury in mouse model. The protective effects of HCE against liver injury were evaluated by biochemical parameters, histopathological and immunohistochemical staining. The results showed that the superoxide dismutase (SOD) activity was significantly increased with the increasing dose of HCE as compared to the CCl4-treated group (p less than 0.01); while AST and ALT levels in serum, MDA and MPO in liver were reduced in a dose-dependent manner. The histopathology showed that HCE treatment promoted the recovery of histopathological changes in liver in a dose-dependent way. Meanwhile, there was a higher expression of caspase-3 and NF-κB in the nucleus of several liver cells in the CCl4-induced group, and a low expression of caspase-3 and NF-κB were found with the increasing dose of HCE. Therefore, the present study suggests that HCE is a potent hepatoprotective agent that can treat acute liver injury and this ability may be attributed towards its anti-inflammatory and antioxidant potential.

Alternaria alternata challenge at the nasal mucosa results in eosinophilic inflammation and increased susceptibility to influenza virus infection

BACKGROUND

Eosinophils in the nasal mucosa are an elemental feature of allergic rhinitis.

OBJECTIVE

Our objective was to explore eosinophilic inflammation and its impact on respiratory virus infection at the nasal mucosa.

METHODS

Inflammation in the nasal mucosae of mice was evaluated in response to repetitive stimulation with strict intranasal volumes of a filtrate of Alternaria alternata. Mice were then challenged with influenza virus.

RESULTS

Repetitive stimulation with A. alternata resulted in eosinophil recruitment to the nasal passages in association with elevated levels of IL-5, IL-13 and eotaxin-1; eosinophil recruitment was diminished in eotaxin-1^-/- mice, and abolished in Rag1^-/- mice. A. alternata also resulted in elevated levels of nasal wash IgA in both wild-type and eosinophil-deficient ∆dblGATA mice. Interestingly, A. alternata-treated mice responded to an influenza virus infection with profound weight loss and mortality compared to mice that received diluent alone (0% vs 100% survival, ***P < .001); the lethal response was blunted when A. alternata was heat-inactivated. Minimal differences in virus titre were detected, and eosinophils present in the nasal passages at the time of virus inoculation provided no protection against the lethal sequelae. Interestingly, nasal wash fluids from mice treated with A. alternata included more neutrophils and higher levels of pro-inflammatory mediators in response to virus challenge, among these, IL-6, a biomarker for disease severity in human influenza.

CONCLUSIONS AND CLINICAL RELEVANCE

Repetitive administration of A. alternata resulted in inflammation of the nasal mucosae and unanticipated morbidity and mortality in response to subsequent challenge with influenza virus. Interestingly, and in contrast to findings in the lower airways, eosinophils recruited to the nasal passages provided no protection against lethal infection. As increased susceptibility to influenza virus among individuals with rhinitis has been the subject of several clinical reports, this model may be used for further exploration of these observations.