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.

[Clinical analysis of hemorrhagic cystitis in children and adolescents with hematological diseases post haplo-hematopoietic stem cell transplantation]

目的

观察儿童及青少年血液病患者单倍型造血干细胞移植（haplo-HSCT）后出血性膀胱炎（HC）的临床特征并探讨其影响因素。

方法

回顾性分析2015至2016年接受haplo-HSCT的89例儿童及青少年血液病患者的临床资料。

结果

全部89例患者中，≤14岁62例（儿童组）、>14~<18岁27例（青少年组）；男56例，女33例；中位移植年龄10（1~17）岁；急性淋巴细胞白血病（ALL）44例，急性髓系白血病（AML）33例，急性混合细胞白血病（AHL）3例，骨髓增生异常综合征（MDS）9例。移植物来源均为骨髓+外周血干细胞。全部89例患者中32例（36%）发生HC，其中迟发型31例，早发型1例；Ⅰ度6例、Ⅱ度16例、Ⅲ度8例、Ⅳ度2例；HC发病中位时间为移植后25（2~55）d，中位持续时间为19（3~95）d；所有患儿均获得治愈。儿童组HC发病率低于青少年组[27.4%（17/62）对55.6%（15/27），χ²=6.466，P<0.05]。儿童组中<5岁组HC发生率低于5~14岁组[0（0/12）对34%（17/50），χ²=4.043，P<0.05]。

结论

HC是儿童及青少年血液病患者haplo-HSCT的常见并发症，总体预后良好，年龄是其发生的影响因素。

IgG1+ B-cell immunity predates IgE responses in epicutaneous sensitization to foods

BACKGROUND

The generation of IgE-mediated food allergy in humans is silent and only diagnosed upon manifestation of clinical symptoms. While experimental models have been used to investigate some mechanisms of allergic sensitization, the generation of humoral immunity and memory remains to be elucidated. Here, we defined the evolution of allergen-specific B-cell responses during epicutaneous sensitization to foods.

METHODS

Wild-type and genetic knockout animals, and drug or antibody strategies for cell depletion and immunoglobulin signaling blockade were used to investigate epicutaneous sensitization and disease progression; we analyzed allergen-specific germinal centers and IgG1⁺ memory B cells by flow cytometry, evaluated humoral responses, and determined clinical reactivity (anaphylaxis).

RESULTS

Epicutaneous sensitization caused microscopic skin damage, inflammation, and recruitment of activated dendritic cells to the draining lymph nodes. This process generated allergen-specific IgG1⁺ germinal center B cells, serum IgG1, and anaphylaxis that was mediated by the alternative pathway. Whether we used peanut and/or ovalbumin from the egg white for sensitization, the allergen-specific IgG1⁺ memory compartment predominantly exhibited an immature, pro-germinal center phenotype (PDL-2^- CD80^- CD35⁺ CD73⁺ ). Subsequent subclinical exposures to the allergen induced IgE⁺ germinal center B cells, serum IgE, and likely activated the classical pathway of anaphylaxis.

CONCLUSIONS

Our data demonstrate that IgG1⁺ B-cell immunity against food allergens in epicutaneous sensitization precedes the generation of IgE responses. Therefore, the assessment of allergen-specific cellular and humoral IgG1⁺ immunity may help to identify individuals at risk of developing IgE-mediated food allergy and hence provide a window for therapeutic interventions.

[Pharmacokinetics of generic dasatinib in the management of chronic myeloid leukemia in the choronie phase]

Objective: To evaluate the pharmacokinetics and bioequivalence of generic dasatinib in patients with chronic myeloid leukemia in the choronie phase (CML-CP). Methods: Using randomized, parallel, overlapping, self-control designed study, a 100 mg dose of the reference or test tablet was given to 12 CML-CP patients who were resistant or intolerant to Imatinib and Nilotinib in a randomized two-way crossover design, and the plasma concentration of the medicine was assayed by HPLC-MS-MS. The main pharmacokinetic parameters and bioequivalence of the two formulations were evaluated. Results: The major pharmacokinetic parameters were as follows: C_max (209.01±58.69) μg/L and (223.07±79.51) μg/L, T_max (1.1±0.8) h and (1.1±0.8) h, T_1/2 (5.10±1.34) h and (4.39±0.74) h, AUC_0-τ (646.65±185.67) h·μg/L and (695.84±273.40) h·μg/L (all P>0.05); AUC_0-∝ (668.11±186.00) h·μg/L and (712.42±278.08) h·μg/L, MRT (5.32 ± 1.70) h and (4.68 ± 1.53) h (all P>0.05). Conclusion: The two formulations were bioequivalent.

GRAPHITE: A Graphical Environment for Scalable in situ Video Tracking of Moving Insects

1. Methods for measuring animal movement are critical for understanding numerous ecological and evolutionary processes. However, few methods are available for small organisms, and even fewer methods offer consistent individual-level resolution while remaining affordable, scalable and operable in the field. 2. We describe a low-cost animal movement tracking method with a user-friendly graphical interface, called GRAPHITE. Our automated software can quantify motions of insects by offline video analysis of inexpensive and lightweight human-readable tags attached to individual insects. The integrated graphical editor provides a full-featured environment for users to review the generated tracking data and make individual- or group-level edits. 3. GRAPHITE is a novel video analysis and graphical editing software (MATLAB v.9.0.0+) that identifies tags in image frames with a minimal false negative rate, links sequences of corresponding tags into "tracks" for each individual insect, infers the tag identifier, and provides a user-friendly graphical environment for editing tracking data. Users can either batch process raw video data using the full analysis pipeline or execute GRAPHITE modules independently for a tailored analysis. 4. We demonstrate the efficacy of the developed software with a specific application to the movement of honey bees at the entrance of hives. However, this system can be easily modified to track individually marked insects of 3 mm and larger. A notable advantage of this method is its ability to provide easy access to individual-level tracking data using human-readable tags.

[A preliminary study on the application of two-point traction with guidewire method in percutaneous transhepatic sinus tract dilation]

Objective: To explore the feasibility and effectiveness of the two-point traction with guidewire method to improve the safety of percutaneous transhepatic sinus tract dilation. Methods: The clinical data of 18 patients underwent the two-point traction guided by percutaneous transhepatic sinus dilation between January 2013 and July 2017 in Shengjing Hospital of China Medical University were analyzed retrospectively. The operation time, volume of intraoperative blood loss and postoperative complications were recorded. Results: All of the 18 patients were treated successfully. The mean size of the percutaneous transhepatic sinus tract was (18.6±2.3) Fr. The operation time was 15-45 min, with an average of 30 minutes, and the average intraoperative blood loss was about 11.7 ml. The incidence of postoperative complications was 22.2% (4/18), including cholangitis in 3 patients, pancreatitis in 1 case. All the complications were relieved after symptomatic treatment, no severe complications (biliary tract perforation or severe haemorrhage) occurred. A total of (3.3 ± 2.6) times cholangioscopic explorations for stone extraction were performed, with a overall clearance rate of 64.7% (11/17). Conclusions: From the results of limited patient data in this group, the two-point traction with guidewire can provide the exact guidance for percutaneous transhepatic sinus tract dilation, which is effective and easily conducted, but still need further clinical study to confirm.

[Metabolic Characteristics of Lethal Bradycardia Induced by Myocardial Ischemia]

OBJECTIVES

To explore the metabolic characteristics of lethal bradycardia induced by myocardial ischemia in rat's serum.

METHODS

A rat myocardial ischemia-bradycardia-sudden cardiac death （MI-B-SCD） model was established, which was compared with the sham-operation group. The metabolic profile of postmortem serum was analyzed by gas chromatography-mass spectrometry （GC-MS）, coupled with the analysis of serum metabolic characteristics using metabolomics strategies.

RESULTS

The serum metabolic profiles were significantly different between the MI-B-SCD rats and the control rats. Compared to the control rats, the MI-B-SCD rats had significantly higher levels of lysine, ornithine, purine, serine, alanine, urea and lactic acid; and significantly lower levels of succinate, hexadecanoic acid, 2-ketoadipic acid, glyceraldehyde, hexendioic acid and octanedioic acid in the serum. There were some correlations among different metabolites.

CONCLUSIONS

There is obvious metabolic alterations in the serum of MI-B-SCD rat. Both lysine and purine have a high value in diagnosing MI-B-SCD. The results are expected to provide references for forensic and clinical applications of prevention and control of sudden cardiac death.

Experimental study of delivery of humidified-warm carbon dioxide during open abdominal surgery

Background

The aim of this study was to monitor the effect of humidified‐warm carbon dioxide (HWCO₂) delivered into the open abdomen of mice, simulating laparotomy.

Methods

Mice were anaesthetized, ventilated and subjected to an abdominal incision followed by wound retraction. In the experimental group, a diffuser device was used to deliver HWCO₂; the control group was exposed to passive air flow. In each group of mice, surgical damage was produced on one side of the peritoneal wall. Vital signs and core temperature were monitored throughout the 1‐h procedure. The peritoneum was closed and mice were allowed to recover for 24 h or 10 days. Tumour cells were delivered into half of the mice in each cohort. Tissue was then examined using scanning electron microscopy and immunohistochemistry.

Results

Passive air flow generated ultrastructural damage including mesothelial cell bulging/retraction and loss of microvilli, as assessed at 24 h. Evidence of surgical damage was still measurable on day 10. HWCO₂ maintained normothermia, whereas open surgery alone led to hypothermia. The degree of tissue damage was significantly reduced by HWCO₂ compared with that in controls. Peritoneal expression of hypoxia inducible factor 1α and vascular endothelial growth factor A was lowered by HWCO₂. These effects were also evident at the surgical damage sites, where protection from tissue trauma extended to 10 days. HWCO₂ did not reduce tumorigenesis in surgically damaged sites compared with passive air flow.

Conclusion

HWCO₂ diffusion into the abdomen in the context of open surgery afforded tissue protection and accelerated tissue repair in mice, while preserving normothermia.

The global regulator CodY responds to oxidative stress by the regulation of glutathione biosynthesis in Streptococcus thermophilus

CodY_st is a global transcriptional regulator that modulates the metabolic network in Streptococcus thermophilus ST2017. In this study, experimental data showed that the cell survival of the codY_st defective mutant obviously declined at the presence of 10 mM H₂O₂, suggesting CodY_st was involved in response to the oxidative stress. To investigate this phenomenon, transcriptome analysis and real time-quantitative PCR were performed and the results indicated that the transcriptional level of a bifunctional glutathione synthetase gene (gshF) was downregulated by about 3-fold in the codY_st defective mutant, along with a decrease by 20% of the glutathione yield compared with the wild-type in minimal chemical defined medium, whereas half of the viable cells remained after H₂O₂ challenge. In vitro gel shift assays showed that the purified CodY_st could bind to the promoter region of gshF, with a conserved CodY_st box, confirming the regulation of CodY_st on the gshF gene. To our knowledge, this is first report of CodY_st in response to oxidative stress mediated by the regulation of gshF in S. thermophilus.