Lysine Content Determination in Xianyu 335 Corn and Its Uncertainty Assessment

[Objective] To establish a mathematical model of uncertainty assessment for lysine content in Xianyu 335 corn by the amino acid assay, completely concerning the sources of uncertainty in the measurement process. [Methods] Analyze and measure the main source of uncertainty, and evaluate and calculate the each component of uncertainty. [Results] For 0.1055 g sample, the lysine determination in Xianyu 335 showed a good linear relationship. [Conclusion] This method is suitable for the Uncertainty Evaluation of lysine measurement in Xianyu 335 by amino acid assay

Danshensu exerts cardioprotective effects in rats with acute myocardial infarction via reduction of infiltration of inflammatory cells and mitigation of myocardial fibrosis

Purpose: To investigate the mitigative impact of danshensu on heart tissues in acute myocardial infarction (AMI) rats, and the mechanism of action involved. Methods: Seventy-five male Sprague-Dawley (SD) rats were used in this study. After successful induction of myocardial infarction, the rats were divided into model group (MG), low-dose danshensu group (LDG; 15 mg/kg), middle-dose danshensu group (MDG; 30 mg/kg), and high-dose danshensu group (HDG; 60 mg/kg), with 15 rats per group. Rats in sham group (SG; n = 15) served as control. Serum levels of biochemical indicators and expressions of various proteins in myocardial tissue were determined using Western blotting, and compared amongst the rat groups. Results: Serum cTnI concentrations in MDG and HDG were significantly decreased, relative to the corresponding concentrations in MDG. There were significantly lower serum concentrations of IL-1 in MDG and HDG than in model rats. Rats in HDG had lower serum IL-6 concentration than MG rats, while TNF-α levels were down-regulated in MDG and HDG, relative to MG (p < 0.05). Conclusion: Danshensu protects the heart function of rats with AMI by decreasing inflammationderived cells and mitigating myocardial fibrosis. Thus, it may be useful in the management of AMI in humans but clinical trials are necessary to ascertain this. Keywords: Danshens; Acute myocardial infarction; Myocardial ischemia-reperfusion; Myocardial fibrosi

Quaternary amines exert anti-myocardial ischemia effects via regulation of energy metabolism and oxygen free radicals in myocardial cells in acute myocardial infarction rats

Purpose: To investigate the effect of quaternary amines on myocardial cells of a rat model of cardiac arrest, with respect to energy generation potential and oxygen free radicals. Methods: Forty-five Sprague-Dawley (SD) rats were assigned to sham, model and quaternary amine groups (each with 15 rats). After their corresponding treatments, lectrocardiogram (ECG) monitoring of the rats in the three groups at various time periods was carried out. Serum levels of myocardial enzymes, thromboxane B2 (TXB2), prostacyclin I2 (PGI2), serum carbon monoxide (CO), and changes in endothelial carbon monoxide synthase (eNOS) and endothelin (ET), were determined. Results: The levels of NO and eNOS were significantly reduced in model rats, relative to sham operation rats, while ET was significantly elevated in sham rats (p < 0.05). There were higher levels of NO and eNOS in the quaternary amine group than in model rats, but ET was higher in quaternary amine group than in model rats. Thromboxane B2 (TXB2) concentration was higher in model rats than in sham rats (p < 0.05). While PGI2 was markedly lower in quaternary group than in sham operation rats. TXB2 was lower in the quaternary amine group than in model rats, while PGI2 was significantly higher in quaternary amine group, relative to model rats (p < 0.05). Conclusion: Quaternary amines exert anti-myocardial effects by regulating energy metabolism and oxygen free radicals in myocardial cells of congestive heart failure rats, and thus are potentially useful for the management of acute myocardial infarction. Keywords: Quaternary amine; Acute myocardial infarction; Electrocardiogram; Serum myocardial enzymes; Myocardial cell

Black Hole Hyperaccretion Inflow-outflow Model. I. Long And Ultra-long Gamma-ray Bursts

Long-duration gamma-ray bursts (LGRBs) and ultra-LGRBs (ULGRBs) originate from collapsars, in the center of which a newborn rotating stellar-mass black hole (BH) surrounded by a massive accretion disk may form. In the scenario of the BH hyperaccretion inflow-outflow model and Blandford-Znajek (BZ) mechanism to trigger gamma-ray bursts (GRBs), the real accretion rate to power a BZ jet is far lower than the mass supply rate from the progenitor star. The characteristics of the progenitor stars can be constrained by GRB luminosity observations, and the results exceed usual expectations. LGRBs lasting from several seconds to tens of seconds in the rest frame may originate from solar-metallicity (Z ∼ 1 Z⊙, where Z and Z⊙ are the metallicities of progenitor stars and the Sun), massive (M ≳ 34 M⊙, where M and M⊙ are the masses of progenitor stars and the Sun) stars or some zerometallicity (Z ∼ 0) stars. A fraction of low-metallicity (Z ≲ 10-2Z⊙) stars, including Population III stars, can produce ULGRBs such as GRB 111209A. The fraction of LGRBs lasting less than tens of seconds in the rest frame is more than 40%, which cannot conform to the fraction of the demanded type of progenitor star. It possibly implies that the activity timescale of the central engine may be much longer than the observed timescale of prompt emission phase, as indicated by X-ray late-time activities. Alternatively, LGRBs and ULGRBs may be powered by a millisecond magnetar central engine. © 2017. The American Astronomical Society. All rights reserved

Blood-Oxygenation-Level-Dependent-(BOLD-) Based R2′ MRI Study in Monkey Model of Reversible Middle Cerebral Artery Occlusion

Objective. To investigate the value of BOLD-based reversible transverse relaxation rate (R2′) MRI in detecting ischemic penumbra (IP) in a monkey model of reversible middle cerebral artery occlusion (MCAO) and time evolution of relative R2′ (rR2′) in infarcted core, IP, and oligemia. Materials and Methods. 6 monkeys were used to make MCAO by the microcatheter method. MR scans were performed at 0 h (1 h after MCAO), 1 h, 3 h, 6 h, 12 h, 24 h, and 48 h after reperfusion. R2′ was calculated using quantitative T2 and T2* maps. Ischemic area was subdivided into infracted core, IP and oligemia. rR2′ was calculated respectively. Results. Reversible MCAO model for 4/6 monkeys was made successfully. rR2′ values were significantly different at each time point, being highest in oligemia followed by IP and infarcted core (P < .05). With reperfusion time evolution, rR2′ in infarcted core showed a decreased trend: sharply decreased within 6 hours and maintained at 0 during 6–48 hours (P < .05). rR2′ values in IP and oligemia showed similar increased trend: sharply increased within 6 hours, maintained a plateau during 6–24 hours, and slightly increased until 48 hours. Conclusion. BOLD-based R2′ MRI can be used to describe changes of cerebral oxygen extract in acute ischemic stroke, and it can provide additional information in detecting IP. The time evolution rR2′ in infarcted core, IP, and oligemia is in accordance with the underlying pathophysiology