Surface modification, strengthening effect and electrochemical comparative study of Zn-Al2O3-CeO3 and Zn-TiO2-CeO3 coating on mild steel

Surface enhancement of engineering materials is necessary for preventing service failure and corrosion attacks industrially. The surface modification, strengthening effect and electrochemical comparative study of Zn-Al2O3-CeO3 and Zn-TiO2-CeO3 coating on mild steel was investigated. Deposition was performed to obtain a better surface adherent coating using the electrodeposition technique. Co-deposition of mild steel resulted into surface modification attributes to the complex alloys that were developed. Films of mild steel were electrodeposited on zinc electrodes using the chloride bath solutions. The effect of deposition potentials was systematically studied using a focus ion beam scanning electron microscope (FIB-SEM) and an atomic force microscope (AFM) to observe the surface morphology, topography and the surface adherent properties of the coatings. The elemental composition and the phases evolved in composite coatings were measured by means of the energy dispersed spectrometer (EDS). The microhardness measurements and corrosion behaviours of the deposits were investigated. Weight loss measurement was conducted on the plated samples to observe the rate of corrosion and it was observed that there was severe corrosion on the controlled sample in comparison to the plated samples and that Zn-TiO2-CeO3 resisted more corrosion attacks

Effect of WO3 Nanoparticle Loading on the Microstructural, Mechanical and Corrosion Resistance of Zn Matrix/TiO2-WO3 Nanocomposite Coatings for Marine Application

In this study, for marine application purposes, we evaluated the effect of process parameter and particle loading on the microstructure, mechanical reinforcement and corrosion resistance properties of a Zn-TiO2-WO3 nanocomposite produced via electrodeposition. We characterized the morphological properties of the composite coatings with a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS). We carried out mechanical examination using a Dura Scan hardness tester and a CERT UMT-2 multi-functional tribological tester. We evaluated the corrosion properties by linear polarization in 3.5% NaCl. The results show that the coatings exhibited good stability and the quantitative particle loading greatly enhanced the structural and morphological properties, hardness behavior and corrosion resistance of the coatings. We observed the precipitation of this alloy on steel is greatly influenced by the composite characteristics

Response to Letter Regarding Article, "Comparison of Transplacental Treatment of Fetal Supraventricular Tachyarrhythmias With Digoxin, Flecainide, and Sotalol: Results of a Nonrandomized Multicenter Study"

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Chemical interaction, interfacial effect and the microstructural characterization of the induced zinc–aluminum–Solanum tuberosum in chloride solution on mild steel

In this study, we report the effect of Solanum tuberosum (ST) as a strong additive on the morphological interaction, wear, and hardness properties of electroplated zinc coating in chloride bath solutions. The structural and the mechanical behavior of the Zn–Al–ST coating were studied and compared with the properties of Zn coatings. Characterization of the electrodeposited coatings were carried out using scanning electron microscopy, energy dispersive spectrometer, AFM, and X-ray diffraction techniques. The adhesion between the coatings and substrate was examined mechanically using hardness and wear techniques. From the results, amorphous Zn–Al–ST coatings were effectively obtained by electrodeposition using direct current. The coating morphology was revealed to be reliant on the bath composition containing strong leveling additives. From all indications, ST content contribute to a strong interfacial surface effect leading to crack-free and better morphology, good hardness properties, and improved wear resistance due to the precipitation of Zn2Si and Zn7Al2Si3. Hence, addition of ST is beneficial for the structural strengthening, hardness, and wear resistance properties of such coatings

Use of uterine fundal pressure maneuver at vaginal delivery and risk of severe perineal laceration

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Polycystic ovary syndrome

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the presence of hyperandrogenism, ovulatory dysfunction and PCOM. Treatment should be tailored to the complaints and needs of the patient and involves targeting metabolic abnormalities through lifestyle changes, medication and potentially surgery for the prevention and management of excess weight, androgen suppression and/or blockade, endometrial protection, reproductive therapy and the detection and treatment of psychological features. This Primer summarizes the current state of knowledge regarding the epidemiology, mechanisms and pathophysiology, diagnosis, screening and prevention, management and future investigational directions of the disorder.Robert J Norman, Ruijin Wu and Marcin T Stankiewic

Comparison of Transplacental Treatment of Fetal Supraventricular Tachyarrhythmias With Digoxin, Flecainide, and Sotalol Results of a Nonrandomized Multicenter Study

Fetal tachyarrhythmia may result in low cardiac output and death. Consequently, antiarrhythmic treatment is offered in most affected pregnancies. We compared 3 drugs commonly used to control supraventricular tachycardia (SVT) and atrial flutter (AF). We reviewed 159 consecutive referrals with fetal SVT (n=114) and AF (n=45). Of these, 75 fetuses with SVT and 36 with AF were treated nonrandomly with transplacental flecainide (n=35), sotalol (n=52), or digoxin (n=24) as a first-line agent. Prenatal treatment failure was associated with an incessant versus intermittent arrhythmia pattern (n=85; hazard ratio [HR]=3.1; P <0.001) and, for SVT, with fetal hydrops (n=28; HR=1.8; P=0.04). Atrial flutter had a lower rate of conversion to sinus rhythm before delivery than SVT (HR=2.0; P=0.005). Cardioversion at 5 and 10 days occurred in 50% and 63% of treated SVT cases, respectively, but in only 25% and 41% of treated AF cases. Sotalol was associated with higher rates of prenatal AF termination than digoxin (HR=5.4; P=0.05) or flecainide (HR=7.4; P=0.03). If incessant AF/SVT persisted to day 5 (n=45), median ventricular rates declined more with flecainide (-22%) and digoxin (-13%) than with sotalol (-5%; P <0.001). Flecainide (HR=2.1; P=0.02) and digoxin (HR=2.9; P=0.01) were also associated with a higher rate of conversion of fetal SVT to a normal rhythm over time. No serious drug-related adverse events were observed, but arrhythmia-related mortality was 5%. Flecainide and digoxin were superior to sotalol in converting SVT to a normal rhythm and in slowing both AF and SVT to better-tolerated ventricular rates and therefore might be considered first to treat significant fetal tachyarrhythmi

Multifaceted incorporation of Zn-Al2O3/Cr2O3/SiO2 nanocomposite coatings: anti-corrosion, tribological, and thermal stability

Nano-sized particle incorporation into metal matrix has gained worldwide acceptance. Al2O3, Cr2O3, and SiO2 nanoparticles have been co-deposited with Zn using electrodeposition process to produce advanced alloy. The coatings were characterized using SEM/EDX and XRD. The mechanical properties of the coatings were studied using microhardness indenter and dry abrasive wear tester. Zn-10 g/L Cr2O3 nanocomposite exhibited the highest microhardness of 228 HVN; Zn-5 g/L Al2O3 nanocomposite possessed the highest corrosion resistance and lowest wear loss. Zn-5 g/L SiO2 nanocomposite showed good stability against other composite coatings. The incorporation of the Al2O3, Cr2O3, and SiO2 shows grain refinement and modify orientation on Zn matrix

Imidacloprid-Induced Impairment of Mushroom Bodies and Behavior of the Native Stingless Bee Melipona quadrifasciata anthidioides

Declines in pollinator colonies represent a worldwide concern. The widespread use of agricultural pesticides is recognized as a potential cause of these declines. Previous studies have examined the effects of neonicotinoid insecticides such as imidacloprid on pollinator colonies, but these investigations have mainly focused on adult honey bees. Native stingless bees (Hymenoptera: Apidae: Meliponinae) are key pollinators in neotropical areas and are threatened with extinction due to deforestation and pesticide use. Few studies have directly investigated the effects of pesticides on these pollinators. Furthermore, the existing impact studies did not address the issue of larval ingestion of contaminated pollen and nectar, which could potentially have dire consequences for the colony. Here, we assessed the effects of imidacloprid ingestion by stingless bee larvae on their survival, development, neuromorphology and adult walking behavior. Increasing doses of imidacloprid were added to the diet provided to individual worker larvae of the stingless bee Melipona quadrifasciata anthidioides throughout their development. Survival rates above 50% were only observed at insecticide doses lower than 0.0056 µg active ingredient (a.i.)/bee. No sublethal effect on body mass or developmental time was observed in the surviving insects, but the pesticide treatment negatively affected the development of mushroom bodies in the brain and impaired the walking behavior of newly emerged adult workers. Therefore, stingless bee larvae are particularly susceptible to imidacloprid, as it caused both high mortality and sublethal effects that impaired brain development and compromised mobility at the young adult stage. These findings demonstrate the lethal effects of imidacloprid on native stingless bees and provide evidence of novel serious sublethal effects that may compromise colony survival. The ecological and economic importance of neotropical stingless bees as pollinators, their susceptibility to insecticides and the vulnerability of their larvae to insecticide exposure emphasize the importance of studying these species