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.

[Clinical features and laboratory data analysis of Aeromonas bacteremia with hematological diseases]

目的

分析患有血液系统疾病患者气单胞菌血流感染的临床及实验室特征，为该类患者气单胞菌感染的防治提供依据。

方法

回顾性分析中国医学科学院血液病医院2014年1月至2018年12月5年发生气单胞菌血症的血液系统疾病患者，收集患者临床感染特征、菌株耐药性、发生季节、治疗及转归情况等相关信息。

结果

共42例血液病患者发生气单胞菌血流感染，其中39例（92.9%）血流感染发生于粒细胞缺乏（粒缺）期，平均发热时间为4（1~27）d，22例（52.4%）患者症状仅为发热，6例（14.3%）伴消化道症状（腹痛、腹泻、恶心、上消化道出血），8例（19.0%）伴肺部感染，13例（31.0%）伴皮肤软组织感染。7例（16.7%）患者死亡，且均伴皮肤软组织感染。气单胞菌对碳青霉烯类抗菌药物的耐药率为68.3%~70.7%，而对头孢菌素类、喹诺酮类及氨基糖苷类抗菌药物的耐药率均小于10%。

结论

血液系统疾病合并气单胞菌血流感染主要发生在粒缺期，主要以发热为主，当伴有皮肤软组织感染时死亡率高。抗菌药物选择应依据药敏结果，避免使用碳青霉烯类抗菌药物。

[Expression and influencing factors of hepcidin in classical paroxysmal nocturnal hemoglobinuria]

目的

研究铁调素在经典型阵发性睡眠性血红蛋白尿症（PNH）患者血清中的表达及其影响因素。

方法

以2016年3月至2017年3月36例经典型PNH患者为研究对象，采用ELISA方法检测血清铁调素水平，并结合患者铁稳态状况和临床资料，分析经典型PNH患者血清铁调素水平与血清铁蛋白（SF）、可溶性转铁蛋白受体、C反应蛋白、EPO、网织红细胞绝对值、网织红细胞血红蛋白等血液学参数的相关性。

结果

36例经典型PNH患者血清铁调素水平为32.03（23.11，118.48）µg/L，明显低于正常对照组的181.42（106.80，250.53）µg/L（z=−5.107，P<0.001）。其中，铁蛋白正常经典型PNH患者血清铁调素水平为56.41（44.60，95.06）µg/L，经典型PNH伴缺铁组血清铁调素水平为23.75（21.77，30.35）µg/L，均低于正常对照组；而经典型PNH伴铁蛋白升高组血清铁调素水平为336.19（304.19，375.08）µg/L，高于正常对照组、铁蛋白正常经典型PNH组及经典型PNH伴缺铁组。多重线性回归分析显示SF、转铁蛋白饱和度和血清白蛋白水平是经典型PNH患者血清铁调素水平的独立影响因素。

结论

经典型PNH患者血清铁调素水平减低，其表达主要受铁代谢因素影响。

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.

Comparison of different approaches to the surgical treatment of penile fractures: quicker return to sexual function with longitudinal incisions

The objective of this study was to compare the long-term clinical outcomes from longitudinal incisions and subcoronal circumferential degloving incisions in the surgical treatment of penile fractures. From July 2001 to July 2014, 23 patients were identified with penile fractures. Fourteen patients underwent longitudinal incisions after ultrasound localization; nine patients underwent subcoronal circumferential degloving incisions. Sexual function was evaluated preoperatively and postoperatively using an abridged International Index of Erectile Function (IIEF) questionnaire. The mean (±s.d.) operative time was 19.1 (±3.9) min in the longitudinal incision group and was 45.1 (±6.5) min in the subcoronal circumferential degloving incision group (P<0.05). The mean (±s.d.) times required to recover sexual function were 35.6 (±6.0) days in the longitudinal incision group and 54.0 (±5.8) days in the circumferential incision group (P<0.05). Six months postoperatively, the erectile functions of all cases were comparable to the level preoperatively except three patients. One patient from each group reported symptoms associated with mild ED, but they experienced satisfying sexual orgasms after psychotherapy for 2 months. Another patient's score on the IIEF-5 declined from 25 to 24 points in the circumferential incision group 10 months postoperatively, and this was associated with maintaining an erection after vaginal penetration. In conclusion, the longitudinal incision may allow quicker return to sexual function but not necessarily improved the long-term clinical outcomes. Furthermore, postoperative psychosocial nursing and psychotherapy should receive more attention.

Effects of a biocontrol agent and methyl jasmonate on postharvest diseases of peach fruit and the possible mechanisms involved

AIMS

To investigate effects of application of 200 micromol l(-1) methyl jasmonate [MeJA (200)] and Cryptococcus laurentii alone or in combination against postharvest diseases (Monilinia fructicola and Penicillium expansum) in peach fruit stored at 25 and 0 degrees C, and to evaluate the possible mechanisms involved.

METHODS AND RESULTS

The efficacy of controlling postharvest diseases by resistance induced in peach fruit treated with MeJA (200) and C. laurentii alone or in combination and the relationship between activities of defence-related enzymes in peach fruit and lesions caused by M. fructicola and P. expansum were examined. At the same time, the effects of MeJA (200) on the population of C. laurentii in the peach wounds and on the mycelial growth of M. fructicola and P. expansumin vitro were investigated. The results indicated that treatment of peach fruit with C. laurentii at 1 x 10(8) CFU ml(-1) alone, or combining C. laurentii at 5 x 10(7) CFU ml(-1) with MeJA (200) all resulted in a lower lesion diameter of brown rot and blue mould caused by M. fructicola and P. expansum compared with the controls in peach fruit. MeJA (200) enhanced the population of C. laurentii, and inhibited mycelial growth of P. expansum. However, it had a little effect on M. fructicolain vitro. MeJA and C. laurentii alone or in combination induced higher activities of Chitinase, beta-1,3-glucanase, phenylalanine ammonia-lyase and peroxidase (POD) than applying the yeast alone at both 25 and 0 degrees C.

CONCLUSIONS

MeJA (200) not only directly inhibited mycelial spread of postharvest pathogens, but also increased population of C. laurentii, which induced stronger disease resistance in fruit than MeJA or yeast alone, and resulted in a lower lesion diameter of brown rot and blue mould caused by M. fructicola and P. expansum.

SIGNIFICANCE AND IMPACT OF THE STUDY

MeJA (200) in combination with C. laurentii was beneficial for controlling brown rot and blue mould caused by M. fructicola and P. expansum in peach fruit. The inhibitory mechanism was mainly because of resistance induced in peach fruit by MeJA and C. laurentii. In addition, direct inhibition of MeJA on P. expansum also played a role in controlling blue mould.

Transcriptional mapping in Chilo iridescent virus infections

Chilo iridescent virus (CIV) belongs to the family Iridoviridae, which are icosahedral cytoplasmic DNA viruses with large, linear, and circularly permuted genomes. Previous studies on infected-cell-specific polypeptides suggested temporal regulation of CIV gene expression. Recently, we demonstrated three temporal classes at the transcriptional level, in CIV infections of a spruce budworm cell line. We also demonstrated a transcriptional cascade with positive and negative control. In this paper, we assign all detectable viral transcripts into respective temporal classes and map them using restriction fragments from a genomic library. More than 90 percent of the genome is transcriptionally active with at least four major clusters of immediate-early transcription and at least three delayed-early clusters. Late transcripts were observed throughout the genome. There was at least one exclusive region in the genome for each of the three temporal classes. We correlated transcribed regions with ORFs on the CIV genome and showed that known ORFs in the exclusive regions are generally consistent with phase-specific requirements of large DNA viruses. Our data also suggest the presence of 5' or 3' coterminal transcripts. This is the first complete transcription map for a member of the genus Iridovirus.

Effective induction, purification and characterization of Trichoderma koningii G-39 beta-xylosidase with high transferase activity

A beta-xylosidase was induced and purified from the culture filtrate of Trichoderma koningii G-39, grown in a medium containing 1% oat spelts xylan and 0.1% xylose. The presence of xylose unequivocally enhanced the induction of beta-xylosidase. The purified enzyme, which exhibited a significant alpha-arabinosidase activity, was obtained with high yield simply via ethanol precipitation and a single anion-exchange chromatography and was characterized as a monomeric glycoprotein with an estimated molecular mass of 104 kDa and a pI of 4.6. The K(m) values towards p-nitrophenyl beta-D-xylopyranoside and p-nitrophenyl alpha-L-arabinopyranoside are 0.04 and 7.5 mM, respectively. It is stable at pH 2.5-7.4, 37 degrees C. The pH and temperature optima are in the range of 3.5-4.0 and 55-60 degrees C, respectively. Contrary to most beta-xylosidases from other sources, Hg(2+) (up to 25 mM) has no effect on enzyme activity. Xylose was shown to inhibit the purified enzyme with a moderate K(i) value of 5 mM. The enzyme exhibited transxylosylation activity and was characterized as a 'retaining' enzyme, catalysing the hydrolysis of substrate with the retention of anomeric configuration.

Mechanistic study of beta-xylosidase from Trichoderma koningii G-39

The catalytic mechanism of the beta-xylosidase purified from the culture filtrate of Trichoderma koningii G-39 was investigated. By NMR spectroscopy, the stereochemistry of the enzyme catalyzing the hydrolysis of 2,4-dinitrophenyl and p-nitrophenyl-beta-D-xylosides was found unequivocally to involve retention of the anomeric configuration. Based on the k(cat) values of a series of arylxylosides with leaving group pK(a)s in the range of 4-10, an extended Bronsted plot was constructed with a slope (beta(lg)) near zero. Enzymatic hydrolysis of aryl-beta-D-xylosides in acetate buffer (pH 4.0) containing 3 or 5% methanol showed a constant product ratio (methylxyloside/xylose), indicating the presence of a common intermediate, probably the xylosyl-enzyme intermediate. In the presence of DTT, the k(cat) values of p-cyanophenyl-beta-D-xylopyranoside and p-nitrophenyl-beta-D-xylopyranoside increased greatly. A two-step mechanism involving the formation and breakdown of the xylosyl-enzyme intermediate was therefore proposed. The rate-limiting step is the breakdown of the intermediate. The secondary deuterium kinetic isotope effect (k(H)/k(D)) measured for 2,4-dinitrophenyl-beta-D-xyloside was 1.02+/-0.01, suggesting that the transition state for breakdown of the xylosyl-enzyme intermediate is S(N)2-like.