3,882 research outputs found

    The energy distribution of relativistic electrons in the kilo-parsec scale jet of M87 with Chandra

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    The X-ray emission from the jets in Active Galactic Nuclei (AGN) carries important information on the distributions of relativistic electrons and magnetic fields on large scales. We reanalyze archival Chandra observations on the jet of M87 from 2000 to 2016 with a total exposure of 1460 kiloseconds to explore the X-ray emission characteristics along the jet. We investigate the variability behaviours of the nucleus and the inner jet component HST-1, and confirm indications for day-scale X-ray variability in the nucleus contemporaneous to the 2010 high TeV gamma-ray state. HST-1 shows a general decline in X-ray flux over the last few years consistent with its synchrotron interpretation. We extract the X-ray spectra for the nucleus and all knots in the jet, showing that they are compatible with a single power-law within the X-ray band. There are indications of the resultant X-ray photon index to exhibit a trend, with slight but significant index variations ranging from ≃2.2\simeq 2.2 (e.g. in knot D) to ≃2.4−2.6\simeq 2.4-2.6 (in the outer knots F, A, and B). When viewed in a multi-wavelength context, a more complex situation is arising. Fitting the radio to X-ray spectral energy distributions (SEDs) assuming a synchrotron origin, we show that a broken power-law electron spectrum with break energy EbE_b around 1 (300μG/B)1/21~(300\mu G/B)^{1/2} TeV allows a satisfactorily description of the multi-band SEDs for most of the knots. However, in the case of knots B, C and D we find indications that an additional high energy component is needed to adequately reproduce the broadband SEDs. We discuss the implications and suggest that a stratified jet model may account for the differences.Comment: accepted for publication in A&

    Tentative evidence of spatially extended GeV emission from SS433/W50

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    We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the latest source catalog and diffuse background models, the gamma-ray excess from SS433/W50 is detected with a significance of 6{\sigma} in the photon energy range of 500 MeV - 10 GeV. Our analysis indicates that an extended flat disk morphology is preferred over a point-source description, suggesting that the GeV emission region is much larger than that of the TeV emission detected by HAWC. The size of the GeV emission is instead consistent with the extent of the radio nebula W50, a supernova remnant being distorted by the jets, so we suggest that the GeV emission may originate from this supernova remnant. The spectral result of the GeV emission is also consistent with an supernova remnant origin. We also derive the GeV flux upper limits on the TeV emission region, which put moderate constrains on the leptonic models to explain the multiwavelength data.Comment: 7 pages, 4 figures, accepted for publication in A&

    Next generation sequencing in early diagnosis of pneumocystis jirovecii pneumonia after chemotherapy: a case report

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    The incidence of Pneumocystis pneumonia is increasing in immunosuppressive patients. How to diagnose and treat Pneumocystis pneumonia in the early stage has become an important issue for clinicians. The development of Next-generation Sequencing (NGS) provides technical support for the diagnosis of Pneumocystis pneumonia. Case report: A 14-year-old male patient was diagnosed with T lymphoblastoma and treated with chemotherapy. After chemotherapy, the patient developed bone marrow suppression and was complicated with severe pneumonia. He was given endotracheal intubation and ventilator assisted respiration. Samples of patients' alveolar lavage fluid were obtained, and Next-generation Sequencing (NGS) was used for diagnosis, confirming the pathogen as Pneumocystis jiroveci, which was treated by TMP/SMX. The patient's condition gradually improved, and was finally removed from ventilator and endotracheal tube. Pneumocystis jiroveci is a common opportunistic pathogen in immunosuppressive patients, and Next-generation Sequencing (NGS) can be used for rapid diagnosis of Pneumocystis pneumonia, thus improving the clinical therapeutic effect.

    De novo acute megakaryoblastic leukemia with p210 BCR/ABL and t(1;16) translocation but not t(9;22) Ph chromosome

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    Acute megakaryoblastic leukemia (AMKL) is a type of acute myeloid leukemia (AML), in which majority of the blasts are megakaryoblastic. De novo AMKL in adulthood is rare, and carries very poor prognosis. We here report a 45-year-old woman with de novo AMKL with BCR/ABL rearrangement and der(16)t(1;16)(q21;q23) translocation but negative for t(9;22) Ph chromosome. Upon induction chemotherapy consisting of homoharringtonine, cytarabine and daunorubicin, the patient achieved partial hematological remission. The patient was then switched to imatinib plus one cycle of CAG regimen (low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor), and achieved complete remission (CR). The disease recurred after 40 days and the patient eventually died of infection. To the best of our knowledge, this is the first report of de novo AMKL with p210 BCR/ABL and der(16)t(1;16)(q21;q23) translocation but not t(9;22) Ph chromosome

    Effects of flavonoids extracted from the whole plant of Patrinia Villosa (Thunb) Juss in a rat model of chronic pelvic inflammation

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    Purpose: To investigate the effects of total flavonoids (PLV) extracted from the  whole plant of Patrinia Villosa (Thunb.) Juss (PTJ) in a rat model of chronic pelvic inflammation.Methods: An orthogonal test design was employed to optimize the extraction  conditions of PLV via reflux extraction by ethanol. Rats were randomly divided into control group, model group and PLV groups. An absorbable gelatin sponge with  pathogens was inserted into the cervix of the rat to establish a pelvic inflammatory model. The PLV groups were orally administered PLV at doses of 25, 50 and 100 mg/kg for eight days. Enzyme-linked immunosorbent assay (ELISA) was used for the determination of inflammatory cytokines in rat serum and the culture  supernatant of RAW264.7 cells. Real-time reverse transcription polymerase chain reaction (real-time PCR) was employed to determine mRNA levels.Results: The optimum extraction conditions for PLV by orthogonal test were  obtained: extraction time (120 min), ratio of liquid to raw material (20 mL/g) and ethanol concentration (50 %). By treating with PLV, the levels of TNF-α, IL-6 and IL-1β significantly decreased (p < 0.01), while IL-10 level significantly increased (p < 0.01) in the serum of chronic pelvic inflammatory rats and LPS-stimulated  macrophages. In addition, a similar trend was observed in the mRNA levels of LPS-stimulated macrophages treated with PLV.Conclusion: PLV showes significant anti-inflammatory effects on chronic pelvic inflammation. The potential mechanism is related to regulating the expression of inflammatory factorsKeywords: Patrinia Villosa (Thunb.) Juss, Total flavonoids, Chronic pelvic  inflammation, Inflammatory cytokine

    Comparison of the therapeutic effects of continuous hyperthermic peritoneal perfusion with systemic intravenous chemotherapy

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    Purpose: To compare the effectiveness and safety of intravenous cisplatin (DDP) and 5-fluorouracil (5-FU) alone or in combination with continuous hyperthermic peritoneal perfusion (CHPP) for the treatment of malignant ascites.Methods: In the study, 124 patients with tumour-induced malignant ascites were assign to test and control groups according to the sequence of their hospital visits. Patients in the test group were treated with intravenous DDP and 5-FU combined with CHPP, whereas patients in the control group were only treated with DDP and 5-FU. The treatments in both groups lasted for 4 weeks. Thereafter, treatment efficacy, remission of abdominal distension, ascites, Karnofsky Performance Scale (KPS) score, and incidence of adverse reactions were compared between the two groups.Results: The overall response rates of the test and control groups were 85.50 (53/62) and 35.50 % (22/62), respectively, and the difference was significant (p < 0.05). Patients in the test group showed significant reduction in abdominal distension and markedly reduced ascites compared to the controls. The improvement in KPS score was superior in the test group (p < 0.05). No treatment-associated complications, such as intestinal adhesions or obstruction and grade III or IV toxic and side reactions, were found in either group. The incidence of adverse reactions was lower in the test group than in the controls.Conclusion: Chemotherapy in combination with CHPP is safe and effective for patients with advanced malignant tumours and ascites should be promoted clinically.Keywords: Malignant ascites, Continuous hyperthermic peritoneal perfusion, Systemic intravenous chemotherap

    PEG10 directly regulated by E2Fs might have a role in the development of hepatocellular carcinoma

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    AbstractPEG10 is an imprinted gene which is up-regulated in hepatocelluar carcinoma (HCC). However, the mechanism of PEG10 regulation remains to be elucidated. In this work the transcription factors E2F-1 and -4 were demonstrated to bind directly to the promoter of PEG10 and thereby regulate its expression. The expression profile of HCC tissues also suggested E2Fs were involved in PEG10 regulation. Further functional analysis showed that PEG10 was involved in the repression of apoptosis induced by serum deprivation and chemotherapeutic drugs. These findings link cancer genetics and epigenetics by showing that E2F acts directly upstream of an anti-apoptosis imprinted gene, PEG10
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