Stopped-Flow Kinetic Study of Reduction of Ferric Maltol Complex by Ascorbate

Stopped-flow kinetic investigation of reduction of Fe(III)-maltol complex is reported. The rates are dependent on pH in a complex way. On one hand at low pH there is a predominance of Fe(III)(maltol)2 which is easier to reduce compared to Fe(III) (maltol)3 which is more resistant to reduction. On the other hand ascorbate is a stronger reducing agent at higher pH. The rates are also found to be inversely dependent on the concentration of free ligand. These observations are explained by the following rate law:Rate = ((k0 +k1[H+])k2 [Asc-]/ (k-1[HMal] + k2[Asc-])) + k3 [Asc-] ) [FeIII(Mal)3] Here k1 is the rate constant for acid hydrolysis of the Fe(maltol)3 complex to Fe(maltol)2 complex and is directly controlled by H+, k0 is the rate constant for hydrolysis of the Fe(maltol)3 complex to Fe(maltol)2 complex and is an intrinsic process, k-1 is the rate constant of reformation of the tris complex by reaction of the bis complex and the free ligand, k2 is the rate constant for reduction of the bis complex by ascorbate and k3 is the rate constant for the reduction of the tris complex by ascorbate

Comparative assessment of serum biochemical profile in riverine and cultured populations of Channa marulius (Hamilton, 1822)

1010-1016Serum biochemical assessment is an important tool to provide information about the internal organs, metabolic and nutritional parameters and electrolytes. Present study was conducted to determine the serum biochemistry of Channa marulius in hatchery and riverine populations. For this purpose blood samples were collected by caudal vein puncture. Inferences of the study showed non-significantly (p ≥ 0.05) higher values of calcium 10.24 mmol/L as compared to lower 9.66 mmol/L whereas, significantly (p ≤ 0.05) higher values of serum globulin 21.06 g/L, total protein 53.0 g/L, albumin 14.87 g/L, cholesterol 6.116 mmol/L, alanine transaminase 530 U/L and alkaline phosphatase 398 µ/L were observed in cultured populations as compared to lower 20.40 g/L, 44.84 g/L, 12.30 g/L, 5.084 mmol/L, 453 U/L and 255 µ/L in riverine populations. On the other side, non-significantly (p ≥ 0.05) higher values of serum triglyceride 0.674 mmol/L as compared to lower 0.604 mmol/L, while significantly (p ≤ 0.05) higher values of glucose 28.43 g/L, urea 2.541 mmol/L, bilirubin 28.20 µmol/L, chlorine 70.3 mmol/L, potassium 13.43 mmol/L, sodium 126.5 mmol/L and aspartate transaminase 1169 U/L in riverine populations as compared to lower 23.89 g/L, 2.17 mmol/L, 26.23 µmol/L, 61.9 mmol/L, 12.08 mmol/L, 111.2 mmol/L and 1029 U/L were recorded in cultured populations, respectively. Findings of the study will be helpful in the field of biochemistry, physiology and toxicology as well as to enhance the management and rearing potential of the Chnanna marulius

Partial characterization of glutathione S-transferase (GST) isolated from hepatocytes of Cyprinus carpio from river Ravi Punjab, Pakistan

1017-1024Glutathione S-transferase (GST) is vital in oxidative stress. Keeping in view the importance of this enzyme, present study was conducted for partial characterization of GST from hepatocytes of Cyprinus carpio. The inferences showed higher (GST) activity in liver of C. carpio collected from Chashma Barrage (144.33±1.15) as compared to Trimmu Head works (128.66.3±0.577) and Rasul Barrage (111.66±0.577) sampling sites. The highest GST activity was 128±0.333 U mL-1 from the crude extract fraction of liver as compared to other fractions of appraisal fish liver. Whereas the lowest activity (109±0.666 U mL-1) was from desalted fraction. Optical density was recorded by spectrophotometer at 280 nm, the fractions that showed high optical density were subjected to enzyme assay. Highest specific activity was 183.63, 153.84 and 162.50 U mg-1 for purified liver GST of C. carpio captured from Trimmu Head works, Rasul Barrage and Chashma Barrage, respectively. Whereas, fold purification was 2.86, 2.69 and 2.10 while, percent recovery was 78.90, 72.07 and 63.19 %, respectively for purified liver GST. The optimum pH was 6.5, 6.0 and 6.8 whereas, temperature was 30.5 oC, 31 oC and 30 oC followed by substrate concentration 40.3 mM, 40 mM and 41 mM, for purified liver GST of C. carpio captured from Trimmu Head works, Rasul Barrage and Chashma Barrage, respectively. It should be noted that detailed studies can be beneficial in the fields of physiology, biochemistry and toxicology

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Numerical study on nanofluidic transport mechanism in Ellis flow within curved channel comprising compliant walls subjected to peristaltic activity

Peristaltic movement of fluid flows has significant applications in biomedical engineering, medicine, human physiology, etc. Specifically, it is very useful to understand and cure the very common intestinal diseases in human beings. A number of theoretical and empirical models are used to analyze peristaltic movement. In this work, the peristaltic movement of nanofluid is modeled with a non-Newtonian Ellis fluid model in a curved channel with compliant wall properties. The effects of Brownian motion, thermophoresis, and nonlinear radiations are considered in the heat transfer for better thermal analysis. The mathematical modeling of the physical problem yields the nonlinear partial differential equations with boundary conditions. First, the governing partial differential equations are non-dimensionalized, and then the resultant system is simplified by using the assumptions of a small Reynolds number and long wavelength. Then the obtained boundary value problem of differential equations is solved with the built-in Mathematica command NDSolve. The accuracy and reliability of the adopted procedure are verified by comparing the computed results with the reported literature. The impacts of the pertinent parameters (Brownian motion, thermal radiation, mixed convection, and thermophoresis phenomenon) on thermal energy, velocity, concentration, heat transfer rate, and stress at the lower wall are analyzed both in qualitative and quantitative manners. This study revealed some interesting facts, such as the peristaltic-driven motion of nanoliquid is strongly influenced by wall properties (i.e., wall elasticity, mass density, and wall damping). In addition, the flow experienced more resistance in the case of larger wall damping, but larger wall elasticity and mass density provide favorable movement for fluid motion. In addition, mixed convection plays a vital role in heat transfer and nanoparticle concentration in the curved domain. In addition, the curved channel walls have a higher stress factor than straight-plane channels. The results of the current study are very useful to understand many biological phenomena, such as the peristaltic movement of liquid during dialysis, food movement through the intestine, etc

Acetohydroxamatoiron(III) complexes : thermodynamics of formation and temperature dependent speciation.

Studies of the thermodynamics of formation of the acetohydroxamatoiron(III) complexes were carried out in acidic media at temperatures ranging from 293 to 323 K. Through the isolation of the unique UV-visible spectra of all three complexes, it was possible to determine their formation constants and deduce enthalpies and entropies of formation as well as their molar absorptivities. The enthalpies of formation of the mono-, bis- and trisacetohydroxamatoiron(III) complexes were found to be -56.4, -17.09 and +19.74 kJ.mol(-1), respectively. Following the determination of the enthalpy and entropy of formation of these complexes, speciation diagrams were calculated for the complexes at temperatures ranging from 293 to 323 K