Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

Clinical and molecular insights into Glanzmann's thrombasthenia in China

Glanzmann's thrombasthenia (GT) is a rare bleeding disorder characterized by spontaneous mucocutaneous bleeding. The disorder is caused by quantitative or qualitative defects in integrin αIIbβ3 (encoded by ITGA2B and ITGB3) on the platelet and is more common in consanguineous populations. However, the prevalence rate and clinical characteristics of GT in non-consanguineous populations have been unclear. We analyzed 97 patients from 93 families with GT in the Han population in China. This analysis showed lower consanguinity (18.3%) in Han patients than other ethnic populations in GT-prone countries. Compared with other ethnic populations, there was no significant difference in the distribution of GT types. Han females suffered more severe bleeding and had a poorer prognosis. We identified a total of 43 different ITGA2B and ITGB3 variants, including 25 previously unidentified, in 45 patients. These variants included 14 missense, 4 nonsense, 4 frameshift, and 3 splicing site variants. Patients with the same genotype generally manifested the same GT type but presented with different bleeding severities. This suggests that GT clinical phenotype does not solely depend on genotype. Our study provides an initial, yet important, clinical and molecular characterization of GT heterogeneity in China.

Genetic characterization of a novel group of avastroviruses in geese

As part of aetiological studies, we tested 28 samples collected from domestic geese showing enteritis and sporadic death. A novel group of avastroviruses was found in six samples. One isolate was completely sequenced, which comprised 7,148 nucleotides. Pairwise comparisons and phylogenetic analysis demonstrated that the goose astrovirus is highly divergent from all previously described avastroviruses. Our data support the view that domestic geese can be infected by astroviruses with different genetic backgrounds, and have raised a concern about the role of domestic geese as reservoirs for diverse astroviruses.

Multi-level coding-recoding by ultrafast phase transition on Ge2Sb2Te5 thin films

Quickly switching among different states (levels) is crucial for reconfigurable metamaterials and devices. In this study, the dynamics of establishment and transformation of five amorphous or near-amorphous intermediate states with obvious optical contrasts on Ge₂Sb₂Te₅ phase-change thin films driven by ultrashort laser pulses were investigated using real-time reflectivity measurements. The reversible coding-recoding among the five optical levels was realized by using single-shot picosecond laser pulses with designed fluences. The optical constants, crystalline states and surface morphologies before and after ultrafast multi-level coding were also compared and analyzed. These results may lay a foundation for the further design and application of dynamically reconfigurable optical/photonic devices.

Isolation and characterization of pectolytic bacterial pathogens infecting potatoes in Nakuru County, Kenya

AIMS

Isolation and characterization of pectolytic bacteria associated with soft rot disease of potatoes in Nakuru, Kenya, to provide the basis for the development of disease control measures.

METHODS AND RESULTS

Potato tubers showing symptoms of soft rot were collected from different farms in Molo and Mau Narok regions within Nakuru county. Isolation was done using crystal violet pectate medium (CVPM). Out of the 71 isolates that showed growth on CVPM, pathogenicity tests revealed that 36 of them had the ability to macerate tissues of potato tubers. All the isolates yielded a fragment of approximately 1500 bp after 16S rDNA amplification. Using the BIOLOG microbial identification system, 20 bacterial isolates were identified as Pectobacterium carotovorum subsp. carotovorum, 7 were Pseudomonas fluorescens B while 9 were Ps. fluorescens A. Y1/Y2 primers successfully amplified pectate lyase-encoding (pel) gene, approximately 434 bp, in all the 20 P. carotovorum species. The virulence of the isolated strains to cause disease, according to pectinolytic tests, varied with change in incubation temperature of the test samples. Pectobacterium carotovorum strains were the most virulent at 30°C while disease severity due to infection by Ps. fluorescens A strains was high at 20°C compared to the other isolates.

CONCLUSION

This study reveals the identity of pectolytic bacterial species from two genera, Pectobacterium and Pseudomonas, as causative agents of potato soft rot in Nakuru, Kenya.

SIGNIFICANCE AND IMPACT OF THE STUDY

Research findings from this study will aid in developing suitable risk mitigation methods for adoption by farmers to prevent losses due to soft rot.

[Study on relationship between Set gene expression and clinical manifestations in bone marrow of patients with acute myelogenous leukemia]

Objective: To explore the expression and significance of Set gene in Acute myeloid leukemia (AML) patients , and to analyze its effect for the prognosis of AML. Methods: The level of Set gene expression was detected by real-time PCR in 59 AML patients and 20 heathy people. The mutations in C-kit 8/17 gene, NPM1 gene and FLT3-TKD/ITD gene in 59 AML patients were detected by direct sequencing. Results: The level of Set gene expression[1.41(0.41-3.31)]was significantly higher in 59 AML patients.The expression of Set gene was correlated with the percentage of marrow blasts and CR in AML patients (P=0.040, P<0.001); the CR rate of Set gene high expression group was significantly lower than that of Set gene low expression group(32.1% vs 83.9%, P=0.01). In the intermediate-risk of AML patients with chromosome karyotype analysis, the CR rate of Set gene high expression group and low expression group were 34.8% and 88.9%, and there are significantly different between two groups(P<0.001); univariate and multivariate analysis showed that Set gene high expression group correlated with poor OS[4(2-15)months]and EFS[3(2-13)months])(P=0.021, P=0.017). It suggests that the Set gene maybe one of AML independent poor prognostic marker.The level of Set gene expression did not correlate with sex, age, WBC, HGB, PLT, FAB typing, chromosomal karyotype and NPM1, C-Kit8/17, CEBPa, FLT3-ITD/TKD gene mutations in AML patients(all P>0.05). Conclusions: The level of Set gene expression in bone marrow maybe play an important role in AML. The high expression of Set gene indicates poor prognosis in AML patients.

Baicalin inhibits Escherichia coli isolates in bovine mastitic milk and reduces antimicrobial resistance

In this study, we aimed to evaluate the inhibitory effect of baicalin on Escherichia coli in vitro and the effects of baicalin treatment on antimicrobial resistance of the E. coli isolates. Through isolation, purification, and identification, a total of 56 E. coli strains were isolated from 341 mastitic milk samples. The study of inhibition effect of baicalin on the E. coli strains in vitro was focused on permeability and morphology of the isolates using an alkaline phosphatase kit and scanning electron microscopy. Furthermore, the resistance spectrum of the isolates to the common antimicrobial agents was tested at sub-minimum inhibitory concentrations of baicalin by the agar dilution method. Extended-spectrum β-lactamase and plasmid-mediated quinolone resistance genes were amplified by PCR before and after incubation with baicalin. The results revealed that baicalin has certain inhibitory effects on the isolates in vitro. The alkaline phosphatase enzyme activity was significantly increased from 1.246 to 2.377 U/100 mL, and the surface of E. coli was concave and shriveled. Analysis of the resistance spectrum and PCR amplification showed that, after administration with baicalin, the sensitivity of most strains to the selected antimicrobial agents was enhanced. Strikingly, the drug-resistant genes from 71.43% (40/56) of these isolates were found to have drug-resistant genes to different extents. Altogether, the current study confirmed both the inhibitory effect on Escherichia coli in vitro and the reduction of antimicrobial resistance by baicalin. This is the first comprehensive study to report on baicalin, a traditional Chinese medicine that acts on E. coli isolated from the mastitic milk samples.

Role of fibroblast growth factor receptors (FGFR) and FGFR like-1 (FGFRL1) in mesenchymal stromal cell differentiation to osteoblasts and adipocytes

Fibroblast growth factors (FGF) and their receptors (FGFRs) regulate many developmental processes including differentiation of mesenchymal stromal cells (MSC). We developed two MSC lines capable of differentiating to osteoblasts and adipocytes and studied the role of FGFRs in this process. We identified FGFR2 and fibroblast growth factor receptor like-1 (FGFRL1) as possible actors in MSC differentiation with gene microarray and qRT-PCR. FGFR2 and FGFRL1 mRNA expression strongly increased during MSC differentiation to osteoblasts. FGF2 treatment, resulting in downregulation of FGFR2, or silencing FGFR2 expression with siRNAs inhibited osteoblast differentiation. During adipocyte differentiation expression of FGFR1 and FGFRL1 increased and was down-regulated by FGF2. FGFR1 knockdown inhibited adipocyte differentiation. Silencing FGFR2 and FGFR1 in MSCs was associated with decreased FGFRL1 expression in osteoblasts and adipocytes, respectively. Our results suggest that FGFR1 and FGFR2 regulate FGFRL1 expression. FGFRL1 may mediate or modulate FGFR regulation of MSC differentiation together with FGFR2 in osteoblastic and FGFR1 in adipocytic lineage.

A comparative study of low energy radiation response of AlAs, GaAs and GaAs/AlAs superlattice and the damage effects on their electronic structures

In this study, the low energy radiation responses of AlAs, GaAs and GaAs/AlAs superlattice are simulated and the radiation damage effects on their electronic structures are investigated. It is found that the threshold displacement energies for AlAs are generally larger than those for GaAs, i.e., the atoms in AlAs are more difficult to be displaced than those in GaAs under radiation environment. As for GaAs/AlAs superlattice, the Ga and Al atoms are more susceptible to the radiation than those in the bulk AlAs and GaAs, whereas the As atoms need comparable or much larger energies to be displaced than those in the bulk states. The created defects are generally Frenkel pairs, and a few antisite defects are also created in the superlattice structure. The created defects are found to have profound effects on the electronic properties of GaAs/AlAs superlattice, in which charge transfer, redistribution and even accumulation take place, and band gap narrowing and even metallicity are induced in some cases. This study shows that it is necessary to enhance the radiation tolerance of GaAs/AlAs superlattice to improve their performance under irradiation.

[Value of split hand in the differential diagnosis of amyotrophic lateral sclerosis and cervical spondylotic amyotrophy]

Objective: To investigate the value of split hand in the differential diagnosis of amyotrophic lateral sclerosis(ALS) and cervical spondylotic amyotrophy (CSA). Methods: A total of 62 ALS patients, 57 CSA patients and 65 normal controls who visited the Neurology and Spine Department of Beijing Jishuitan Hospital from May 2013 to June 2017 were enrolled into this study.The amplitudes of compound muscle action potentials (CMAP) were recorded from abductor digiti minimi (ADM) and abductor pollicis brevis (APB). Moreover, the ratio of CMAP amplitude between ADM and APB (ADM/APB) was calculated. Results: The ADM/APB of the ALS group (1.93±1.97)was significantly higher than that of the normal control group (0.92±0.22)(P<0.05); the ADM/APB of the CSA group (0.74±0.32)was significantly lower than that of the normal control group (0.92±0.22)(P<0.05); the ADM/APB of the ALS group (1.93±1.97)was significantly higher than that of the CSA group(0.74±0.32)(P<0.05); the areas under receiver operator characteristic curve in patients with ALS was 0.843, the diagnostic sensitivity and specificity for ALS were 75.8% and 83.1% with the cutoff value of ADM/APB=1.077; the areas under receiver operator characteristic curve in patients with CSA was 0.737, the diagnostic sensitivity and specificity for CSA were 64.9% and 87.1% with the cutoff value of ADM/APB=0.739. Conclusion: The ADM/APB has certain clinical value for the differentiation of ALS and CSA.

Expression of IFNAR1 and IFNAR2 in cattle placenta during early pregnancy

Interferon-tau (IFNT), a type I interferon, is an antiluteolytic factor secreted by trophoderm during pregnancy. IFNT transmitted signals or stimulated the expression of some factors to build maternal recognition and keep pregnancy by binding its receptors, IFNT receptor 1(IFNAR1) and IFNT receptor 2 (IFNAR2). Up to now, the expression model and roles of IFNAR1 and IFNAR2 in placenta have not been investigated in cattle. In this study, the localization and expression of IFNAR1 and IFNAR2 in the cattle placenta at days 18-50 of pregnancy were detected by histological examination, immunofluorescence staining and real-time qPCR. The results showed that IFNAR1 mainly distributed in chorioallantoic membrane, endometrial epithelium, cotyledon and caruncle during the early pregnancy of cattle with change in time- and position-dependent. IFNAR1 and IFNAR2 mRNA expression were mainly detected in chorioallantoic membrane and cotyledon, and markedly increased along with pregnancy process. Moreover, the mRNA expression level of IFNAR1 in chorioallantoic membrane and cotyledon was higher than that of IFNAR2. IFNAR mRNA was also expressed in caruncle tissues, which experienced a tendency of decrease from days 21 to 36, followed by increase after days 36. These results provide morphological basis and quantitative data for investigating the roles of IFNAR1 and IFNAR2 on development of cattle placenta and pregnancy maintenance.