Cosmology-independent Estimate of the Fraction of Baryon Mass in the IGM from Fast Radio Burst Observations

The excessive dispersion measure (DM) of fast radio bursts (FRBs) has been proposed to be a powerful tool to study intergalactic medium (IGM) and to perform cosmography. One issue is that the fraction of baryons in the IGM, f IGM, is not properly constrained. Here, we propose a method of estimating f IGM using a putative sample of FRBs with the measurements of both DM and luminosity distance d L. The latter can be obtained if the FRB is associated with a distance indicator (e.g., a gamma-ray burst or a gravitational-wave event), or the redshift z of the FRB is measured and d L at the corresponding z is available from other distance indicators (e.g., SNe Ia) at the same redshift. As d L/DM essentially does not depend on cosmological parameters, our method can determine f IGM independent of cosmological parameters. We parameterize f IGM as a function of redshift and model the DM contribution from a host galaxy as a function of star formation rate. Assuming f IGM has a mild evolution with redshift with a functional form and by means of Monte Carlo simulations, we show that an unbiased and cosmology-independent estimate of the present value of f IGM with a ~12% uncertainty can be obtained with 50 joint measurements of d L and DM. In addition, such a method can also lead to a measurement of the mean value of DM contributed from the local host galaxy

丹蛭降糖胶囊对糖尿病大鼠肾组织NF-κB表达的影响*

Objective: To investigate the expression level of NF- κ B in renal tissue of diabetic rodent model and the regulating action of Danzhi Jiangtang Capsule (DJC) . Methods: 55 male SD rats were randomly divided into 2 groups, normal control group and experimental group. Normal control group was fed with basal diet, the experimental group were fed with high calorie diet. A single intraperitoneal injection of streptozotocin (STZ) of 35mg/kg to establish the animal model of diabetes mellitus, blood glucose was measured after 120h,when the diabetic rodent model was built, the experimental group were randomly divided into 4 groups, high does group of DJC, low does group of DJC , pioglitazone group and model group. In addition to the model group and control group, each group was kept with continuous intragastric administration of drugs for 8 weeks, high does group of DJC, low does group of DJC were treated with 1.08g/ (kg • d), 0.54 g/ (kg • d) by gavage, pioglitazone group was treated with 10mg/ (kg • d) by gavage, the blank group and the model group  were treated with physiological saline 5ml/ (kg • d)  by gavage. Then determined NF-κB by immunohistochemical method and detected blood glucose of rats . Results:  The expression of NF-κB in model group was strongly and significantly increased compared with the normal control group （P＜0.05 or P＜0.01）; after being given Danzhi Jiangtang Capsule for 8 weeks , high expression of NF-κB in high DJC group and low DJC group were significantly decreased (P＜0.05), much more than pioglitazone group . When the diabetic rodent model was built, the blood glucose of model group was increased significantly compared with the control group (P＜0.01).After the experimental group been given Danzhi Jiangtang Capsule for 2 weeks , the level of glucose was decreased significantly compared with model group (P＜0.01) , the blood glucose index declined steadily after 4~8 weeks（P＜0.01）. Conclusion: Danzhi Jiangtang Capsule can reduce blood sugar ,which delay the progression of diabetic nephropathy through inhibiting the high expression of NF- κ B in diabetic rats.目的  探讨NF-κB在糖尿病大鼠肾组织中的表达水平及丹蛭降糖胶囊（DJC）的调节作用。方法  取55只健康雄性大鼠随机分为两组，即正常对照组和实验组。正常对照组予普通饲料喂养，实验组予高脂饲料喂养。采用链尿佐菌素（STZ）单次腹腔注射35mg/kg，建立糖尿病动物模型，120h后测血糖，造模成功后，再将实验组随机分为丹蛭高、低剂量组,吡咯列酮组，模型组。除模型组和对照组外，各组连续灌胃药物8周，丹蛭高、低剂量组分别按1.08g/(kg•d)、0.54 g/(kg•d)灌胃，吡格列酮组按10mg/(kg•d)灌胃，正常对照组和模型组按5ml/(kg•d)给予生理盐水灌胃。免疫组化法检测NF-κB在肾脏中的表达水平，并测定各组大鼠血糖。结果 模型组的NF-κB的表达明显升高，多为强阳性，与正常对照组比较差异有显著性（P＜0.01）；丹蛭高、低剂量组灌胃8周后，两组NF-κB的高表达明显下降，多为弱阳性或不表达，与模型组比较有统计学意义（P＜0.01），疗效优于吡格列酮组。造模后，模型组血糖显著升高（P＜0.01），丹蛭降糖胶囊灌胃2周后，血糖显著下降，与模型组比较（P＜0.01），4~8周后血糖指标下降平稳（P＜0.01）。结论  丹蛭降糖胶囊可能通过抑制糖尿病大鼠NF-κB的高表达，降低血糖，延缓糖尿病肾病的进程