In vivo Assessments of Bioabsorbable AZ91 Magnesium Implants Coated with Nanostructured Fluoridated Hydroxyapatite by MAO/EPD Technique for Biomedical Applications

Although magnesium (Mg) is a unique biodegradable metal which possesses mechanical property similar to that of the natural bone and can be an attractive material to be used as orthopedic implants, its quick corrosion rate restricts its actual clinical applications. To control its rapid degradation, we have modified the surface of magnesium implant using fluoridated hydroxyapatite (FHA: Ca10(PO4)6OH2 − xFx) through the combined micro-arc oxidation (MAO) and electrophoretic deposition (EPD) techniques, which was presented in our previous paper. In this article, the biocompatibility examinations were conducted on the coated AZ91 magnesium alloy by implanting it into the greater trochanter area of rabbits. The results of the in vivo animal test revealed a significant enhancement in the biocompatibility of FHA/MAO coated implant compared to the uncoated one. By applying the FHA/MAO coating on the AZ91 implant, the amount of weight loss and magnesium ion release in blood plasma decreased. According to the histological results, the formation of the new bone increased and the inflammation decreased around the implant. In addition, the implantation of the uncoated AZ91 alloy accompanied by the release of hydrogen gas around the implant; this release was suppressed by applying the coated implant. Our study exemplifies that the surface coating of magnesium implant using a bioactive ceramic such as fluoridated hydroxyapatite may improve the biocompatibility of the implant to make it suitable as a commercialized biomedical product

Vanjski fokus pažnje poboljšava izvedbu bacanja diska

A performer’s focus of attention has been shown to influence motor performance and learning in a variety of motor skills. The purpose of the current study was to examine the effects of an external and internal focus of attention on discus throwing. Participants (N=20; mean age: 22 years, SD: 1.58) were recruited from an undergraduate male student population that had limited experience with the task. Using a within-participants design, all participants completed five maximum effort trials under each attentional focus condition (external and internal). The results of a repeated-measures ANCOVA revealed that participants had a significantly more effective performance in external focus of attention condition compared with the internal attentional focus. These findings are in line with the previous studies showing enhanced motor performance as a result of using external versus internal focus of attention. Therefore, it is suggested that coaches and practitioners give instructions that promote an external focus of attention.Dokazano je da usmjerenost pažnje izvođača motoričkog zadatka utječe na motoričku uspješnost i motoričko učenje velikog broja motoričkih vještina. Cilj je ovog istraživanja bio utvrditi učinke vanjskog i unutarnjeg usmjeravanja (fokusa) pažnje na izvedbu bacanja diska. Dvadeset ispitanika, u dobi od 22±1,58 godina, bilo je uzorkovano iz populacije dodiplomskih studenata koji nisu imali velikog iskustva u izvedbi motoričkog zadatka. Svi su ispitanici izveli zadatak po pet puta maksimalnim intenzitetom u svakoj od situacija usmjerenosti pažnje (vanjska i unutarnja usmjerenost pažnje). Rezultati analize ANCOVA pokazali su da je motorička izvedba bila značajno učinkovitija u uvjetima vanjske usmjerenosti pažnje u usporedbi s izvedbom u uvjetima s unutarnjim fokusom pažnje. Rezultati ovog istraživanja u skladu su s rezultatima ranije provedenih istraživanja koji pokazuju poboljšanu motoričku izvedbu u uvjetima vanjskog fokusa pažnje u odnosu na unutarnji fokus pažnje. Preporuča se, stoga, da treneri i stručnjaci daju instrukcije sportašu u vidu promoviranja vanjskog usmjeravanja pažnje

BASE OIL BLENDS - A GREAT OPPORTUNITY FOR GREASE FORMULATORS

Mineral oils used by grease manufacturers can be divided into two major groups, naphthenic oils and paraffinic oils. These categories of base oils have their own advantages and disadvantages depending on the applications and conditions. The most important advantages of the naphthenic oils over the paraffinic oils, with the same viscosity and similar aromatic content, are better low-temperature flowability and better solvency. The contribution of having base oils with good solvency towards the thickener is that less thickener is needed to obtain a certain consistency of the finished product. For instance, a typical NLGI grade 2 lithium based grease, based on a solvent neutral 500, group one (Gr I) oil, may contain 9-14 wt% thickener; while 6-8% thickener is required for an equivalent viscosity oil of naphthenic nature. Using blends of naphthenic oil and paraffinic group one oil have successfully been used during the past decade in India. However, the author believes that the surplus of paraffinic Gr II and Gr III base oils is one among a number of market trends that brings some great opportunities to the grease formulators, if they look for blends where naphthenic oils are regarded as part of the solution for a sustainable formulation. A number of key parameters important for the performance of the finished product could be obtained within reasonable cost. The purpose of this work was to compare “side by side” three base oil blends where paraffinic Gr I, Gr II and Gr III, in combination with naphthenic, were used for preparation of lubricating greases. Since the target viscosity was 150 mm2/s at 40ºC, a naphthenic oil was used in order to reach this viscosity. The overall results obtained, reveal some interesting aspects of the use of Gr II as a substitute to Gr I for preparation of greases. The outcome of this work emphasizes that blends should be regarded as a great opportunity for grease formulators who are looking for some further development of their current formulations and furthermore, the lubricating grease based on the blend of paraffinic Gr II and naphthenic oil performs better than others

Protective effect of citrus lemon on inflammation and adipokine levels in acrylamide-induced oxidative stress in rats

The high exposure to acrylamide (AA) due to smoking and increased consumption of processed and fast foods in recent years, has become one of the health threatening problems. This study examined the effect of lemon juice on inflammation and adipokines in acrylamide-induced oxidative stress in rats. Forty animals were divided into five groups. Toxicity was induced by AA (35mg/kg) for two weeks in all groups except normal control group. After that, lemon juice in three doses was administrated to treatment groups for 4 weeks. Serum levels of adipokines and inflammatory parameters and both serum and liver levels of oxidative stress parameters were measured. The results showed groups were received AA had significant higher levels of malondialdehyde, tumor necrosis factor alpha, leptin and C-reactive protein and lower levels of total antioxidant capacity compared to the negative control group. Lemon juice in all three doses significantly improved serum levels of TAC, MDA, TNFα and hs-CRP in treated groups. Also, 7.5 ml/kg lemon juice significantly decreased leptin levels. However, lemon juice had no significant effect on adiponectin levels. This study suggests lemon juice as a potential dietary alternative could attenuate leptin levels and manage oxidative and inflammatory damages in acrylamide- induced toxicity in rats

Biodegradable Magnesium Bone Implants Coated with a Novel Bioceramic Nanocomposite

Magnesium (Mg) alloys are being investigated as a biodegradable metallic biomaterial because of their mechanical property profile, which is similar to the human bone. However, implants based on Mg alloys are corroded quickly in the body before the bone fracture is fully healed. Therefore, we aimed to reduce the corrosion rate of Mg using a double protective layer. We used a magnesium-aluminum-zinc alloy (AZ91) and treated its surface with micro-arc oxidation (MAO) technique to first form an intermediate layer. Next, a bioceramic nanocomposite composed of diopside, bredigite, and fluoridated hydroxyapatite (FHA) was coated on the surface of MAO treated AZ91 using the electrophoretic deposition (EPD) technique. Our in vivo results showed a significant enhancement in the bioactivity of the nanocomposite coated AZ91 implant compared to the uncoated control implant. Implantation of the uncoated AZ91 caused a significant release of hydrogen bubbles around the implant, which was reduced when the nanocomposite coated implants were used. Using histology, this reduction in the corrosion rate of the coated implants resulted in an improved new bone formation and reduced inflammation in the interface of the implants and the surrounding tissue. Hence, our strategy using a MAO/EPD of a bioceramic nanocomposite coating (i.e., diopside-bredigite-FHA) can significantly reduce the corrosion rate and improve the bioactivity of the biodegradable AZ91 Mg implant

Prevalence and molecular characterization of alpha-thalassemia among newborns in Ardabil Province

Background and objective: Alpha-thalassemia is one of the most recessively congenital hemoglobin disorders in the world, and is characterized by decreased or absence of alpha globin chains production. Although it has been suggested that the frequency of alpha-thalassemia in Iran is greater than worldwide, its exact rate is unknown. Due to lack of more studies on this topic in this area, the aim of the present study was to determine prevalence and molecular characterization of alpha-thalassemia among newborns in Ardabil Province. Methods: In this cross-sectional study, one thousand newborns were referred for screening of alpha thalassemia at a pediatric unit in Ardabil province between April 2016 and March 2018. Cases with Mean Corpuscular Volume (MCV) <100 fL and Mean Corpuscular Hemoglobin (MCH) < 33 pg were referred for serum Ferritin measurement, Hb electrophoresis and then genetic analysis. Collected data were analyzed by statistical methods such as number, percent and Mean±SD in SPSS version 21. Results: The prevalence of α-thalassemia in studied newborns was 3.3% in Ardabil province. The most common mutation was the 3.7 single gene deletions that were found in 42.4% (14 cases) of newborns with α-Thalassemia. Conclusions: Results showed that, the prevalence of α-thalassemia in Ardabil province was lower than the average rate for the country and the most common mutation was –α3.7/αα, which was similar to other places in Iran

COX inhibition: Catalepsy and Striatum Dopaminergic-GABAergic-Glutamatergic Neurotransmission

Selective COX-2 and COX-1 inhibitors were administered (i.p. acutely) to normal and parkinsonian rats, followed by the analysis of the striatal dopamine, GABA and glutamate concentrations using the microdialysis technique, simultaneously, the catalepsy of animals was evaluated. Selective COX-2 inhibition showed improving effects on the catalepsy followed by decreasing the striatum glutamatergic-GABAergic and enhancing the dopaminergic neurotransmission. Nonetheless COX inhibition had no significant improving effects on damaged Substantia Nigra Pars Compacta (SNc) neurons

Quality of life among Ardabil patients with beta-thalassemia major

Background: Thalassemia as the most common genetic disorder worldwide is regarded as a serious problem in public health issues in the Mediterranean region. Patients with beta-thalassemia major experience physical, psychological and social problems that lead to decreased quality of life. The aim of this study was to assess health-related quality of life and its determinants among patients with major beta-thalassemia.Methods: This was a population-based cross-sectional survey of quality of life. Population with thalassemia major (aged ≥ 2 years) of both genders who had records in Thalassemia Clinic of Bu-Ali Hospital, and those who regularly refer for blood transfusion or follow-up visits. Data were collected from December 2013 to May 2014.The self-administered short form-36 (SF-36) questionnaire was used to measure quality of life in patients with thalassemia. Data were analysed using descriptive statistical tests (mean, SD, and frequency), and inferential statistical test (t-test) in SPSS.17 software.Results: Our samples were 20 men and 23 women. The median age was 20 years (2-42). After reviewing the patients' quality of life, it was observed that the mean score for physical function was 79.8, role limitations due to physical reasons 78.8, bodily pain 74.4, general health 59.1, fatigue or vitality 63.3, social function 70.21, role limitations due to psychological reasons (emotional) 77.3 and mental health 65.4. On two scales, role physical (P = 0.33) and role emotional (P = 0.13), the men showed significantly lower scores than the women.Conclusions: After reviewing the patients' quality of life, the highest quality in physical function and lowest quality in general health of patients were observed. In the quality of care data all scales were in very good level except general health.