Electrodeposition and Corrosion Resistance of Ni-Graphene Composite Coatings

The research on the graphene application for the electrodeposition of nickel composite coatings was conducted. The study assessed an important role of graphene in an increased corrosion resistance of these coatings. Watts-type nickel plating bath with low concentration of nickel ions, organic addition agents, and graphene as dispersed particles were used for deposition of the composite coatings nickel-graphene. The results of investigations of composite coatings nickel-graphene deposited from the bath containing 0.33, 0.5, and 1 g/dm³ graphene and one surface-active substance were shown. The contents of particles in coatings, the surface morphology, the cross-sectional structures of the coated samples, and their thickness and the internal stresses were studied. Voltammetric method was used for examination of the corrosion resistance of samples of composite coatings in 0.5 M NaCl. The obtained results suggest that the content of incorporated graphene particles increases with an increasing amount of graphene in plating bath. The application of organic compounds was advantageous because it caused compressive stresses in the deposited coatings. All of the nickel-graphene composite layers had better corrosion resistance than the nickel coating.     

Pathology of sudden death in the young

Demographic trends reveal the elderly to be the fastest growing segment of the population. Physicians can therefore anticipate encountering increasing numbers of older patients with alcohol-related problems. These problems include liver disease, dementia, confusion (masquerading as dementia), peripheral neuropathy, insomnia, late-onset seizure disorder, poor nutrition, incontinence, diarrhea, myopathy, inadequate self-care, macrocytosis, depression, fractures, and adverse reactions to medications. Despite the prevalence of alcohol use in older people, their risks and problems are often unrecognized. We reviewed published literature on the determinants and consequences of alcohol-related problems in persons aged 65 years and older and the usefulness of available screening measures. Thirteen of 25 eligible studies on determinants and consequences met quality criteria and were reviewed. Nine additional studies on screening tests were also evaluated. Determinants include history of alcohol use and abuse, social isolation, and reduced mobility; consequences consist of risks of hip fracture from falls, neoplasms, and psychiatric illness. Currently accessible screening tests focus on high levels of alcoholic beverage use and abuse and dependence. They are not useful in screening for hazardous consumption that may result from relatively low levels of alcohol use alone or in combination with medications, medical illness, or preexisting diminished physical, emotional, or social function. Research is needed on the consequences of lower levels of alcohol consumption on the physical and psychosocial health of older individuals and on methods for distinguishing alcohol-related from age-related problems. Existing screening tests should be expanded or new screening methods developed in anticipation of a growing public health problem.     

Clinical efficacy and safety of a novel controlled-release morphine suppository and subcutaneous morphine in cancer pain: a randomized evaluation

PURPOSE: A significant number of cancer patients will require an alternate route of morphine administration at some point during their illness. This study compared the clinical efficacy and safety of a novel morphine sulfate controlled-release suppository (MS-CRS) and subcutaneous (SC) morphine in patients with cancer pain. METHODS: Thirty patients with cancer pain were randomized in a double-blind crossover study to MS-CRS every 12 hours or SC morphine every 4 hours for 4 days each, using a 2.5:1 analgesic equivalence ratio. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed with a VAS. Evaluations were made by the patient at 8 AM, noon, 4 PM, and 8 PM and rescue morphine consumption recorded. RESULTS: Twenty-three patients completed the study (13 men and 10 women; mean age, 64.0 +/- 2.0 years) and were treated with mean daily MS-CRS and SC morphine doses of 326 +/- 69 mg and 138 +/- 28 mg, respectively. There was a small but significant difference in overall ordinal pain-intensity scores in favor of MS-CRS (0.7 +/- 0.1 v 0.9 +/- 0.1, P = .0459). There were no significant differences between MS-CRS and SC morphine in overall VAS scores for pain intensity (13 +/- 3 v 13 +/- 3 mm), sedation (23 +/- 3 v 25 +/- 4 mm), and nausea (8 +/- 2 v 9 +/- 2 mm). The mean daily rescue analgesic consumption during MS-CRS and SC morphine did not differ significantly (1.2 +/- 0.4 v 1.2 +/- 0.4 doses/d). CONCLUSION: MS-CRS, administered every 12 hours, provides analgesia comparable to SC morphine and represents a reliable, noninvasive alternative method of pain control for patients unable to take oral morphine.     

The Influence of Method of Carburizing and Nitrocarburizing on the Microstructure and Properties of Tool Steels

The paper presents the results of wear and metallography tests of tool steel grades: ASTM A681, ChI2M and Ch12FS per GOST, AMS 6437E i BS X46Cr13, all surface hardened by the Carbo process (carburizing) and by the NiCar process (nitrocarburizing). The therrno-chemical treatment was conducted in powder pack for a duration of 6 h (carburizing) and for 4 h in the case of nitrocarburizing. Factors investigated were: morphology, depth and microhardness of the cases obtained, their microstructure, as well as phase composition. Wear tests were conducted by the three cylinder-cone method.Wear velocity was 0.58 m/s, unit load was 50 MPa and 400Mpa, wear path was 3470 m. Oil SAE30 was applied at the rate of 30 drops per minute.     

Ligand-induced conformational transitions in Escherichia coli phosphofructokinase 2: evidence for an allosteric site for MgATP2-

The binding of ligands to phosphofructokinase 2 (Pfk-2) from Escherichia coli induces changes in the fluorescence emission properties of its single tryptophan residue, Trp88, suggesting that upon binding the protein undergoes a conformational change. This fluorescence probe was used to determine the presence of an allosteric site for MgATP2- in the enzyme. Fructose 6-phosphate (fructose-6-P), the first substrate that binds to the enzyme with an ordered bi-bi mechanism, increases the fluorescence up to 30%. The saturation curve for this compound is hyperbolic with a Kd of 6 microM. The titration of Pfk-2 with MgATP2- causes a quenching of fluorescence of about 30% of its initial value, with a blue shift of 7 nm in the emission maximum. The response is cooperative with a Kd of 80 microM and a Hill coefficient of 2. The interaction of MgATP2- cannot take place at the active site in the absence of fructose-6-P, due to the ordered kinetic mechanism. Addition of compounds that bind to the catalytic site of Pfk-2, such as ATP4- or Mg-AMP-PNP, did not produce significant changes in the fluorescence spectrum of Trp88. However, in the absence of Mg2+, the addition of ATP4- to the enzyme-fructose-6-P complex shows a hyperbolic increase of fluorescence of 8%. Acrylamide steady-state quenching experiments for different enzyme-ligand complexes of Pfk-2, indicate that the tryptophan in the enzyme-MgATP2- complex is exposed to a much smaller extent to the solvent than in the free enzyme or in the enzyme-fructose-6-P complex. The effect of the binding of fructose-6-P or MgATP2- on the polarization fluorescence of the emission of Trp88 in Pfk-2 indicates changes in the local mobility of the Trp88 in both enzyme complexes. The average lifetime for Trp88 in Pfk-2 was found to be unusually large, approximately 7.7 ns, and did not vary significantly with the ligation state of the enzyme, which demonstrates that the quenching or enhancement of fluorescence induced by the ligands is mainly due to the complex formation with Pfk-2. These results demonstrate the presence of an allosteric site for MgATP2- in Pfk-2 from E. coli, responsible for the inhibition of the enzyme activity by this ligand.     

CO2 separation performance by chitosan/tetraethylenepentamine/poly(ether sulfone) composite membrane

CO₂ separation from CO₂/N₂ (20:80) gas mixture has been demonstrated by tetraethylenepentamine blended with chitosan (CS‐TEPA) membrane. Optimization of CS and TEPA weight ratio were carried out based on characterization details involving thermogravimetric analysis, Fourier transform infrared spectroscopy, X‐ray diffraction, atomic force microscope, and field emission scanning electron microscope. Effects of water flow rate, pressure, and temperature were concurrently studied on CS‐TEPA membranes through gas permeation. Almost twofold increase in CO₂ permeance (24.7 GPU) was detected in CS blend with 30% (w/w) of TEPA (CS70) as compared to pure CS membrane (12.5 GPU). CS70 yielded CO₂/N₂ selectivity of 80 whereas CS demonstrated a maximum of 54 at 90 °C. The membrane also exhibited improved stability at temperatures less than 120 °C which was evident from TGA isotherm trace. The proposed composite membrane can be a promising candidate for flue gas separation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45206.     

Preparation and characterization of poly(ethylene glycol) stabilized nano silver particles by a mechanochemical assisted ball mill process

Nano silver particles with an average mean crystallite size of between 10 and 12 nm were synthesized from different molecular weights of poly(ethylene glycol) as a stabilizing agents, through solid state oxidation of silver nitrate using a higher energy planetary ball mill. Ultraviolet‐Visible spectra were used to confirm the synthesis of nano silver particles. The surface plasmon resonance bands were observed around 410 nm. Fourier transformed infrared spectrum, X‐ray diffraction, and transmission electronic microscopy techniques were used to characterize the nano silver particles synthesized. Thermal stability was determined using thermogravimetic analysis and the elemental composition of the sample was determined by energy dispersive X‐ray analysis. The nano silver particles synthesized, exhibited very good antibacterial activity against Gram‐positive bacteria (Bacillus) and Gram‐negative bacteria (Pseudomonas aeruginosa). Based on the obtained results, it was additionally explored that the size and the stabilization of the nano silver particles synthesized, strongly depend on the molecular weight of poly(ethylene glycol). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43027.     

(Fe)-C-N合金经沉淀硬化后的疲劳强度

为了寻求新的方法促进渗氮工艺在重型机械零件中的应用，渗氮层的硬化及通过对基体和心部进行进一步奥氏体化并快冷使其硬化的可能性引起了注意。本文给出了渗氮后的45钢(C-0．45％；Mn-0．65％)经沉淀硬化处理后的疲劳强度试验结果。试验结果表明经沉淀硬化后其近表层获得了不同的组织，可发现形态上与不同沉淀分散程度的贝氏体组织相似的纯马氏体区。渗氮后沉淀硬化有利于碳钢及其抗疲劳强度。本文还讨论了渗氮后沉淀硬化处理可替代渗碳或感应淬火。     

Efficacy of oxycodone in neuropathic pain: a randomized trial in postherpetic neuralgia

OBJECTIVE: Although opioid analgesics are used in the management of neuropathic pain syndromes, evidence of their efficacy remains to be established. We evaluated the clinical efficacy and safety of oxycodone in neuropathic pain using postherpetic neuralgia as a model. METHODS: Patients with postherpetic neuralgia of at least moderate intensity were randomized to controlled-release oxycodone 10 mg or placebo every 12 hours, each for 4 weeks, using a double-blind, crossover design. The dose was increased weekly up to a possible maximum of 30 mg every 12 hours. Pain intensity and pain relief were assessed daily, and steady (ongoing) pain, brief (paroxysmal) pain, skin pain (allodynia), and pain relief were recorded at weekly visits. Clinical effectiveness, disability, and treatment preference were also assessed. RESULTS: Fifty patients were enrolled and 38 completed the study (16 men, 22 women, age 70+/-11 years, onset of postherpetic neuralgia 31+/-29 months, duration of pain 18+/-5 hours per day). The oxycodone dose during the final week was 45+/-17 mg per day. Compared with placebo, oxycodone resulted in pain relief (2.9+/-1.2 versus 1.8+/-1.1, p=0.0001) and reductions in steady pain (34+/-26 versus 55+/-27 mm, p=0.0001), allodynia (32+/-26 versus 50+/-30 mm, p=0.0004), and paroxysmal spontaneous pain (22+/-24 versus 42+/-32 mm, p=0.0001). Global effectiveness, disability, and masked patient preference all showed superior scores with oxycodone relative to placebo (1.8+/-1.1 versus 0.7+/-1.0, p=0.0001; 0.3+/-0.8 versus 0.7+/-1.0, p=0.041; 67% versus 11%, p=0.001, respectively). CONCLUSIONS: Controlled-release oxycodone is an effective analgesic for the management of steady pain, paroxysmal spontaneous pain, and allodynia, which frequently characterize postherpetic neuralgia.