Evaluation the Efficiency of Various Types of Corrosion Inhibitors Used for Basrah Water Storage Tanks

In this paper, the efficiency of six different types of corrosion inhibitors used in Basrah drinking water tanks was assessed using a potentiostatic test method. The mechanism of adsorption of silicate and phosphate inhibitors in AISI 316 stainless steel surfaces and the effects of different water components in inhibitors are discussed in detail. The values of corrosion rate obtained from the Potentiostatic test showed that the protection against corrosion in the presence of inhibitors is better compared to the case of absence of inhibitors. The results of the six types of corrosion inhibitors tested showed that the inhibitory efficacy is higher below the temperatures 45oC, but when raise the temperature above 45oC the inhibitory efficiency becomes to decrease. Also, the test results indicated that the corrosion inhibitor involves silicate products provided more inhibited efficiency compared to the phosphate inhibitor alone or used the combined silicate/phosphate corrosion inhibitor. The inspection of the surface of the tested samples using optical methods shows that the pitting corrosion is demonstrated on the specimen surfaces after testing with or without inhibitors.

Protein Tyrosine Phosphatase (PTP1B): A promising Drug Target Against Life-threatening Ailments

Background: Protein tyrosine phosphatases are enzymes which help in the signal transduction in diabetes, obesity, cancer, liver diseases and neurodegenerative diseases. PTP1B is the main member of this enzyme from the protein extract of human placenta. In phosphate inhibitors development, significant progress has been made over the last 10 years. In early-stage clinical trials, few compounds have reached whereas in the later stage trials or registration, yet none have progressed. Many researchers investigate different ways to improve the pharmacological properties of PTP1B inhibitors. Objective: In the present review, authors have summarized various aspects related to the involvement of PTP1B in various types of signal transduction mechanisms and its prominent role in various diseases like cancer, liver diseases and diabetes mellitus. Conclusion: There are still certain challenges for the selection of PTP1B as a drug target. Therefore, continuous future efforts are required to explore this target for the development of PTP inhibitors to treat the prevailing diseases associated with it.

Crystallization of CaCO3 in Aqueous Solutions with Extremely High Concentrations of NaCl

The effect of NaCl at extremely high concentrations from 3.5 to 14 wt. % on the crystallization of CaCO3 was investigated in depth. The static test experiment verified that the Ca2+ retention efficiency (η) of NaCl on CaCO3 scale increased from 31.06% (3.5 wt. %) to 41.56% (14 wt. %). Based on the calculation of supersaturation rations, the high concentration of NaCl could reduce the activity coefficients of [Ca2+] and [CO32−], thus reducing the actual concentration of CaCO3. The CaCO3 deposition rate constants (k) showed that NaCl slowed down the rate of CaCO3 crystallization. The X–ray diffraction (XRD) testing disclosed that the growth of (1 0 4) and (1 1 0) faces from calcite was impeded, while the formation of (1 1 1) face from aragonite was induced by the increasing concentration of NaCl. The inductively coupled plasma optical emission spectrometry (ICP–OES) results indicated that Na+ could be doped into CaCO3, leading to the one–dimensional crystal growth. It was further proved that NaCl heightens the efficiency of the typical phosphate inhibitors (2–phosphonobutane–1,2,4–tricarboxylic acid (PBTCA) and 1–hydroxyethane–1,1–diphosphonic acid (HEDP)) on prohibiting the scale of CaCO3.

Evidence of Multiple Pesticides Resistance in the Tomato Leaf Miner Tuta Absoluta Meyrick (1917) from Savannah Region of Northern Nigeria

In 2016 northern Nigeria experienced a devastating infestation by the tomato leaf miner, leading to soaring in prices of tomato across the country. Unfortunately, information on the bionomics and resistance status of this pest is lacking in northern Nigeria, hampering appropriate control measures. Here, we identified to species level, and using conventional and synergist bioassays characterised pesticides resistance profile of a field population of a tomato leaf miner from northern Nigeria. Highest resistance was obtained with λ-cyhalothrin (Type II pyrethroid) with a low mortality (18.52% at 56hr) and LD50 of 7461.474ppm. Resistance was also established toward propoxur and chlorpyrifos-methyl with average mortalities each of 56% and LD50s of 1023.51ppm and 106.351ppm, respectively. Highest susceptibility was seen with abamectin with mortality of 86% and LD50 of  0.034ppm. Pre-exposure to piperonyl butoxide significantly recovered λ–cyhalothrin susceptibility (mortality = 90% and LD50 = 0.92ppm) implicating the P450 monoxygenases in the resistance. No significant changes in mortalities were obtained on pre-exposure to diethyl maleate and triphenyl-phosphate- inhibitors of glutathione S-transferases and carboxylesterases, respectively. The finding of resistance to these agricultural pesticides will sensitize stakeholders across Nigeria to take action to manage the resistance at an early stage before it gets out of hand.