145 research outputs found

    An Asymmetrical Model for High Energy Radiation of Cassiopeia A

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    Cassiopeia A (Cas A) supernova remnant shows strong radiation from radio to gamma-ray bands. The mechanism of gamma-ray radiation in Cas A and its possible contribution to PeV cosmic rays are still under debate. The X-ray imaging reveals an asymmetric profile of Cas A, suggesting the existence of a jet-like structure. In this work, we propose an asymmetrical model for Cas A, consisting of a fast moving jet-like structure and a slowly expanding isotropic shell. This model can account for the multi-wavelength spectra of Cas A, especially for the power-law hard X-ray spectrum from ∼\sim 60 to 220 keV. The GeV to TeV emission from Cas A should be contributed by both hadronic and leptonic processes. Moreover, the jet-like structure may produce a gamma-ray flux of ∼10−13erg cm−2 s−1\sim 10^{-13}\rm erg\ cm^{-2}\ s^{-1} at ∼100\sim 100 TeV, to be examined by LHAASO and CTA.Comment: 7 pages, 7 figures. MNRAS in pres

    Constraining interacting dark energy models with the halo concentration - mass relation

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    The interacting dark energy (IDE) model is a promising alternative cosmological model which has the potential to solve the fine-tuning and coincidence problems by considering the interaction between dark matter and dark energy. Previous studies have shown that the energy exchange between the dark sectors in this model can significantly affect the dark matter halo properties. In this study, utilising a large set of cosmological NN-body simulations, we analyse the redshift evolution of the halo concentration - mass (cc - MM) relation in the IDE model, and show that the cc - MM relation is a sensitive proxy of the interaction strength parameter ξ2\xi_2, especially at lower redshifts. Furthermore, we construct parametrized formulae to quantify the dependence of the cc - MM relation on ξ2\xi_2 at redshifts ranging from z=0z=0 to 0.60.6. Our parametrized formulae provide a useful tool in constraining ξ2\xi_2 with the observational cc - MM relation. As a first attempt, we use the data from X-ray, gravitational lensing, and galaxy rotational curve observations and obtain a tight constraint on ξ2\xi_2, i.e. ξ2=0.071±0.034\xi_2 = 0.071 \pm 0.034. Our work demonstrates that the halo cc - MM relation, which reflects the halo assembly history, is a powerful probe to constrain the IDE model.Comment: 9 pages, 5 figures, 5 table

    Clinical efficacy and safety of Kanglaite injection, adjuvant cemcitabine and cisplatin chemotherapy for advanced non-small-cell lung cancer: A systematic review and meta-analysis

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    Purpose: To investigate the effectiveness and safety of the combination of Kanglaite injection (KLTi) and gemcitabine and cisplatin (GP) chemotherapy in the treatment of advanced non-small cell lung cancer (NSCLC).Methods: PubMed, Web of Science, Embase, Cochrane Library, CNKI, Wan-Fang, CBM, and CQVIP were comprehensively searched from January 2010 till November 2020. Randomized controlled trials (RCTs) of KLTi plus GP in the treatment of NSCLC were selected and assessed for inclusion. Review Manager 5.3 software was used for meta-analysis.Results: Twenty-five RCTs on advanced NSCLC examined the inclusion criteria. The meta-analysis showed that compared with GP chemotherapy alone, KLTi plus GP chemotherapy significantly improved objective response rate (ORR) (RR = 1.36, 95% CI 1.23-1.51, p < 0.00001), disease control rate (DCR) (RR = 1.17, 95% CI 1.11 - 1.23, p < 0.00001), and reduced adverse drug reactions(ADRs) such as hair loss (RR = 0.60, 95% CI 0.47 - 0.76, p < 0.0001), gastrointestinal reaction (RR = 0.68, 95% CI 0.62 - 0.75, p < 0.00001), impairment of liver and kidney function (RR = 0.65, 95% CI 0.53 - 0.80, p < 0.001), nervous system damage (RR = 0.42, 95% CI 0.26 - 0.69, p = 0.0005), myelosuppression (I-II phase) (RR = 0.79, 95 % CI 0.66 - 0.95, p = 0.01), myelosuppression (III-IV phase) (RR = 0.44, 95 % CI0.27 - 0.72, p = 0.001), anemia (RR = 0.74, 95 % CI 0.60 - 0.91, p = 0.006), leukopenia (RR = 0.78, 95% CI 0.69, 0.87, p < 0.0001), thrombocytopenia (RR = 0.59, 95 % CI 0.49, 0.72, p < 0.00001), hypochromia (RR = 0.74, 95% CI 0.59, 0.92, p = 0.008).Conclusion: KLTi adjuvant GP chemotherapy reduces adverse effects in patients with advanced NSCLC. Thus, KLTi might be an effective and safe intervention for NSCLC&nbsp

    Therapeutic Angiogenesis of Chinese Herbal Medicines in Ischemic Heart Disease:A Review

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    Ischemic heart disease (IHD) is one of the primary causes of death around the world. Therapeutic angiogenesis is a promising innovative approach for treating IHD, improving cardiac function by promoting blood perfusion to the ischemic myocardium. This treatment is especially important for targeting patients that are unable to undergo angioplasty or bypass surgery. Chinese herbal medicines have been used for more than 2,500 years and they play an important role alongside contemporary medicines in China. Growing evidence in animal models show Chinese herbal medicines can provide therapeutic effect on IHD by targeting angiogenesis. Identifying the mechanism in which Chinese herbal medicines can promote angiogenesis in IHD is a major topic in the field of traditional Chinese medicine, and has the potential for advancing therapeutic treatment. This review summarizes the progression of research and highlights potential pro-angiogenic mechanisms of Chinese herbal medicines in IHD. In addition, an outline of the limitations of Chinese herbal medicines and challenges they face will be presented

    Impacts of hyperfractionated radiotherapy at different fractionated doses on short- and long-term efficacy and toxicity in patients with limited stage small cell lung cancer

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    Objective: To explore the short-and long-term efficacy and toxic and side effects of hyperfractionated radiotherapy with different fractionated doses in patients with limited stage small cell lung cancer (SCLC). Methods: From August 2017 to August 2019, 70 patients with limited stage SCLC admitted to Zhangye People’s Hospital were selected and divided into control group (n=35) and observation group (n=35) according to the random number table method. Conventional chemotherapy and hyperfractionated radiotherapy were used in both groups, with a total dose of 45 Gy in the control group and 60 Gy in the observation group. A three-year follow-up was carried out to compare the short- and long-term efficacy (survival and local control rate), and the occurrence of toxic and side effects between the two groups. Results: The total effective rate in the observation group was obviously higher than that in the control group (91.43% vs 71.43%, χ2=4.629, P=0.031). The 1-, 2-, and 3-year local control rates and survival rates of patients in the observation group were significantly higher than those in the control group (P<0.05). There was no statistically significant difference in the total incidence of adverse reactions between the two groups (P>0.05), and most of adverse reactions were grade Ⅰ-Ⅱ, which did not affect the course of treatment. After treatment, the scores of life quality in both groups increased significantly (P<0.01), and the observation group showed a significant increase compared to the control group (P<0.01). Conclusion: Hyperfractionnated radiotherapy with appropriately increased fractionated dose for patients with limited stage SCLC has better short- and long-term efficacy, higher local control rate and survival, and no significant increase in toxic and side effects, which is safe and can improve the quality of patients' life

    Bone marrow mesenchymal stem cells from leukemia patients inhibit growth and apoptosis in serum-deprived K562 cells

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    <p>Abstract</p> <p>Background</p> <p>The regulation of growth and apoptosis in K562 cells by human bone marrow mesenchymal stem cells (MSCs) from leukemia patients was investigated.</p> <p>Methods</p> <p>K562 cells were cocultured with leukemic MSCs under serum deprivation. Cell Counting Kit-8 (CCK-8), PI staining, Annexin V/PI binding and FACS assays were used to investigate cell proliferation, cell cycle status, and apoptosis of K562 cells cultures in the presence or absence of 10% serum. Western blotting was used to determine the levels of Akt, phosphorylated Akt (p-Akt), the BCL-2 family member Bad, and phosphorylated Bad (p-Bad) proteins in K562 cells after coculturing with MSCs. The effects of LY294002 (a specific inhibitor of PI3K) on protein expression were also determined.</p> <p>Results</p> <p>K562 cell proliferation was inhibited by coculture with MSCs and the dominant cell cycle was the G<sub>0</sub>-G<sub>1 </sub>phase. The proportion of apoptotic K562 cells was decreased and the levels of p-Akt and p-Bad were upregulated after exposing K562 cells to MSCs. However, when LY294002 was used, p-Akt and p-Bad proteins inK562 cells showed a significant reduction, while no distinct variation was seen in the nonphosphorylated Akt and Bad protein levels.</p> <p>Conclusion</p> <p>Leukemic MSCs can inhibit K562 cell expansion and modulate the cell cycle to a state of relative quiescence. This allows the K562 cells to endure adverse conditions such as serum starvation. The PI3K-Akt-Bad signaling pathway may be involved in this antiapoptotic process via phosphorylation of the Akt and Bad proteins. Blocking MSC-induced transduction of the PI3K-Akt-Bad pathway may be a potential strategy for a targeted therapy to combat leukemia.</p

    Causal effect of PM1 on morbidity of cause-specific respiratory diseases based on a negative control exposure

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    Background: Extensive studies have linked PM2.5 and PM10 with respiratory diseases (RD). However, few is known about causal association between PM1 and morbidity of RD. We aimed to assess the causal effects of PM1 on cause-specific RD. Methods: Hospital admission data were obtained for RD during 2014 and 2019 in Beijing, China. Negative control exposure and extreme gradient boosting with SHapley Additive exPlanation was used to explore the causality and contribution between PM1 and RD. Stratified analysis by gender, age, and season was conducted. Results: A total of 1,183,591 admissions for RD were recorded. Per interquartile range (28 μg/m3) uptick in concentration of PM1 corresponded to a 3.08% [95% confidence interval (CI): 1.66%–4.52%] increment in morbidity of total RD. And that was 4.47% (95% CI: 2.46%–6.52%) and 0.15% (95% CI: 1.44%-1.78%), for COPD and asthma, respectively. Significantly positive causal associations were observed for PM1 with total RD and COPD. Females and the elderly had higher effects on total RD, COPD, and asthma only in the warm months (Z = 3.03, P = 0.002; Z = 4.01, P \u3c 0.001; Z = 3.92, P \u3c 0.001; Z = 2.11, P = 0.035; Z = 2.44, P = 0.015). Contribution of PM1 ranked first, second and second for total RD, COPD, and asthma among air pollutants. Conclusion: PM1 was causally associated with increased morbidity of total RD and COPD, but not causally associated with asthma. Females and the elderly were more vulnerable to PM1-associated effects on RD
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