Cardiovascular disease, chronic kidney disease, and diabetes mortality burden of cardiometabolic risk factors from 1980 to 2010: A comparative risk assessment

Background: High blood pressure, blood glucose, serum cholesterol, and BMI are risk factors for cardiovascular diseases and some of these factors also increase the risk of chronic kidney disease and diabetes. We estimated mortality from cardiovascular diseases, chronic kidney disease, and diabetes that was attributable to these four cardiometabolic risk factors for all countries and regions from 1980 to 2010. Methods: We used data for exposure to risk factors by country, age group, and sex from pooled analyses of population-based health surveys. We obtained relative risks for the effects of risk factors on cause-specific mortality from meta-analyses of large prospective studies. We calculated the population attributable fractions for each risk factor alone, and for the combination of all risk factors, accounting for multicausality and for mediation of the effects of BMI by the other three risks. We calculated attributable deaths by multiplying the cause-specific population attributable fractions by the number of disease-specific deaths. We obtained cause-specific mortality from the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study. We propagated the uncertainties of all the inputs to the final estimates. Findings: In 2010, high blood pressure was the leading risk factor for deaths due to cardiovascular diseases, chronic kidney disease, and diabetes in every region, causing more than 40% of worldwide deaths from these diseases; high BMI and glucose were each responsible for about 15% of deaths, and high cholesterol for more than 10%. After accounting for multicausality, 63% (10·8 million deaths, 95% CI 10·1-11·5) of deaths from these diseases in 2010 were attributable to the combined effect of these four metabolic risk factors, compared with 67% (7·1 million deaths, 6·6-7·6) in 1980. The mortality burden of high BMI and glucose nearly doubled from 1980 to 2010. At the country level, age-standardised death rates from these diseases attributable to the combined effects of these four risk factors surpassed 925 deaths per 100 000 for men in Belarus, Kazakhstan, and Mongolia, but were less than 130 deaths per 100 000 for women and less than 200 for men in some high-income countries including Australia, Canada, France, Japan, the Netherlands, Singapore, South Korea, and Spain. Interpretation: The salient features of the cardiometabolic disease and risk factor epidemic at the beginning of the 21st century are high blood pressure and an increasing effect of obesity and diabetes. The mortality burden of cardiometabolic risk factors has shifted from high-income to low-income and middle-income countries. Lowering cardiometabolic risks through dietary, behavioural, and pharmacological interventions should be a part of the global response to non-communicable diseases. Funding: UK Medical Research Council, US National Institutes of Health. © 2014 Elsevier Ltd

Mechanical and biological behaviors of titania and tantala nanotubular arrays decorated with silver oxide on Ti-6Al-4V alloy / Masoud Sarraf

Ti-6Al-4V alloy is among the most widely-used metallic materials for orthopedic and dental application due to its desirable features such as high strength and low density. However, Ti-6Al-4V cannot meet all of the clinical necessities owing to the lack of osseointegration required for implant longevity. The current research aimed to employ a novel surface modification for development of two different metallic oxides, including TiO2 and Ta2O5 nanotubes on biomedical-graded Ti-6Al-4V plates to improve the mechanical properties, tribological, corrosion behavior, osseointegration, and biocompatibility. The optimized self-organized TiO2 nanotubular arrays were fabricated by electrochemical anodization, followed by heat treatment at 500°C for 1.5 h to improve the adhesion strength of nanotubular arrays. On the other hand, for development of well-adherent Ta2O5 nanotubular coatings, an optimized PVD approach to deposit the thin films tantalum followed by a two-step anodization were performed. To improve the adhesion of nanotubular arrays, heat treatment was carried out at 450°C for 1 hour. Moreover, for improving the antibacterial properties of these two coatings, the Ag2O nanoparticles were decorated on the nanotube edges via PVD magnetron sputtering approach. The adhesion strengths between the coatings and substrates were evaluated using a microscratch tester under different conditions. The surface topography of the nanostructured coatings was examined by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy (EDS) and X-ray electron spectroscopy (XPS) were also utilized to investigate the chemical composition of the developed thin films. The corrosion behavior, wear resistance, hardness, surface wettability, in-vitro bioactivity in simulated body fluids (SBF), antibacterial characteristics and biocompatibility of the products were also investigated in order to provide a better understanding of the specimen function in physiological conditions. The effective sputter yield of tantalum during the magnetron sputtering process was achieved with a DC power of 350W, temperature of 250°C and a deposition time of 6h. The anodization results showed that the time and electrolyte played a key role in the growth of TiO2 and Ta2O5 NTs as well as their microstructural evolution. The optimum pore sizes of TiO2 and Ta2O5 nanotubes were around 72nm and 40nm, while their lengths were identical (1μm). The scratch length, failure point, and adhesion strength of the annealed samples were 1000μm, 557.89μm, and 1814.28mN for TiO2 NTs as well as 1024μm, 863μm, and 2301mN for Ta2O5 NTs respectively. The annealed coating showed the highest wettability (lowest contact angle value), tribology (lowest coefficient of friction), corrosion resistance (highest percentage of protection efficiency) and highest hardness value among the specimens. In-vitro bioactivity tests before and after deposition of Ag2O NPs showed that the bone-like apatite layer was formed on nanotubular array coating as early as 1 day immersion in SBF, indicating the importance of nanotubular configuration of the in-vitro bioactivity. Finally, cell culture and antibacterial properties also showed promising results after decoration of Ag2O NPs. This multi-step approach could be considered for the design of various nanostructured titanium implant surfaces

Microstructural, thermal, electrical, and magnetic properties of optimized Fe3O4–SiC hybrid nano filler reinforced aluminium matrix composite

In the present study, the hybrid reinforcements (Fe3O4–SiC) novel composite has been successfully fabricated by powder metallurgy method. Adding Fe3O4 nanoparticles and SiC hybrid reinforcements in the aluminium matrix, improved the magnetic permeability of aluminium matrix composites as well as, thermal properties without mechanical degradation. In this study, the aim was to define the influence of SiC–Fe3O4 nanoparticles on microstructural, thermal, electrical, and magnetic properties of the composite. Based on obtained results, the highest density and hardness is 2.72 g/cm3 and 93 HV respectively. Adding (10–30 wt% SiC) into Al–15Fe3O4 slightly improved the magnetic saturation from approximately 2 to 6 (emu/g) and decreased coercivity from 238 to 177 G. The addition of (30 wt%) Fe3O4 nano particles and (10–20 wt%) SiC into aluminium resulted in magnetic saturation between 5 and 11.058 (emu/g) and decreased coercivity to 131G. Moreover, the thermal conductivity values at high weight percentage (30 wt %) of SiC was 190 W/mk. Increasing the SiC has improved the thermal conductivity of aluminium by 37%. Electrical resistivity of the Al–Fe3O4–SiC composites increased by adding Fe3O4 and SiC. By comparing all samples, Al-30 Fe3O4 -15 SiC can be selected as an optimization composite

Magnetic, Electrical, and Physical Properties Evolution in Fe3O4 Nanofiller Reinforced Aluminium Matrix Composite Produced by Powder Metallurgy Method

An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find the optimum wt.% and its effect on the microstructure, thermal, magnetic, and electrical properties of aluminum matrix composite was conducted using the powder metallurgy method. The purpose of this research was to develop magnetic properties in aluminum. Based on the obtained results, the value of density, hardness, and saturation magnetization (Ms) from 2.33 g/cm3, 43 HV and 2.49 emu/g for Al-10 Fe3O4 reached a maximum value of 3.29 g/cm3, 47 HV and 13.06 emu/g for the Al-35 Fe3O4 which showed an improvement of 41.2%, 9.3%, and 424.5%, respectively. The maximum and minimum coercivity (Hc) was 231.87 G for Al-10 Fe3O4 and 142.34 G for Al-35 Fe3O4. Moreover, the thermal conductivity and electrical resistivity at a high weight percentage (35wt%) were 159 w/mK, 9.9 × 10−4 Ω.m, and the highest compressive strength was 133 Mpa

In vitro bioactivity and corrosion resistance enhancement of Ti-6Al-4V by highly ordered TiO2 nanotube arrays

In the present study, the structural features, corrosion behavior, and in vitro bioactivity of TiO 2 nanotubular arrays coated on Ti–6Al–4V (Ti64) alloy were investigated. For this reason, Ti64 plates were anodized in an ammonium fluoride electrolyte dissolved in a 90:10 ethylene glycol and water solvent mixture at room temperature under a constant potential of 60 V for 1 h. Subsequently, the anodized specimens were annealed in an argon gas furnace at 500 and 700 °C for 1.5 h with a heating and cooling rate of 5 °C min −1 . From XRD analysis and Raman spectroscopy, a highly crystalline anatase phase with tetragonal symmetry was formed from the thermally induced crystallization at 500 °C. Besides, the Ti 2p 3/2 and Ti 2p 1/2 binding energies showed the presence of the Ti 4+ oxidation state. According to the in vitro bioassay, the modified surface proved its outstanding capability in enhancing the bioactivity, where a thick layer of bone-like apatite was formed on the annealed TiO 2 nanotube surface. In addition, the corrosion measurements indicated that the corrosion protection efficiency increased remarkably and reached 87% after annealing at 500 °C. [Figure not available: see fulltext.]. © 2018, Australian Ceramic Society

Micromechanical properties of hydroxyapatite nanocomposites reinforced with CNTs and ZrO2

This study examined the mechanical properties, wettability, and tribology of hydroxyapatite (HA)–zirconia (ZrO2)–carbon nanotube (CNTs) ceramic nanocomposites (with various CNT ratios (x): 1, 5, and 10 wt%). HA–ZrO2–CNT-x powders were hydrothermally synthesized. Hot isostatic pressing (HIP) and cold isostatic pressing were used to manufacture solid and dense tablets; consolidation was performed by sintering the nanocomposites under Ar gas at 1150 °C during HIP. The microstructure and morphology of the nanocomposites were characterized via transmission electron microscopy, energy-dispersive X-ray spectroscopy, powder X-ray diffractometry, Fourier transform infrared (FTIR), and scanning electron microscopy. The effects of ZrO2 and CNTs on the mechanical characteristics of the nanocomposites were examined via nanoindentation, reciprocating wear, and Vickers hardness tests. The microhardness of HA–ZrO2–CNT-1% and HA–ZrO2–CNT-5% increased by 36.8% and 66.67%, respectively, compared with that of pure HA. The nanohardness of the HA–ZrO2–CNT-1%, HA–ZrO2–CNT-5%, and HA–ZrO2–CNT-10% samples was 8.3, 9.65, and 8.02 Gpa, and the corresponding elastic modulus was 83.72, 114.34, and 89.27 GPa, respectively. Both of these parameters were higher than those of pure HA. However, in the nanocomposite reinforced with 10% CNT, as opposed to those with lower CNT ratios, their values were lower. Additionally, HA–ZrO2–CNT-10% was the most hydrophilic nanocomposite synthesized in this study with a contact angle of 48.8°.This work was supported by the National Research Foundation of Korea (grant number NRF-2020R1A4A1019074 ), Qatar National Research Fund, Qatar Foundation , Doha, Qatar (grant number NPRP11S-0102-180178 ), and Ajman University (grant agreement 2021-IRG-ENIT-12).Scopu

Effect of zirconia nanotube coating on the hydrophilicity and mechanochemical behavior of zirconium for biomedical applications

Zirconium has attracted considerable attention in the biomedical field owing to its biocompatibility and desirable tribological and mechanical properties. In this study, we anodized pure zirconium in an ammonium fluoride and ethylene glycol electrolyte, which produced a coating of ZrO2 nanotubes (NTs). The ZrO2 coated samples were annealed at different temperatures, and the morphology and structure of the coated substrates were studied using XPS, SEM, TEM, EDS, and SAED. The micro/nanomechanical properties and corrosion resistance of the samples were evaluated. Wear tests performed on bare and coated substrates revealed that the coated samples annealed at 400 °C had a significantly lower average coefficient of friction than the other substrates. The corrosion test was performed on different substrates, and the results showed that the corrosion resistance of the coated sample annealed at 400 °C was considerably higher than that of the other substrates. According to the nanoindentation tests, the elastic modulus of the Zr sample decreased from 74.3 to 31.7 GPa after anodization and the creation of ZrO2 NTs. Biocompatibility tests revealed that cell attachment to the surface of the ZrO2 NTs decreased due to the presence of F−; however, the cell viability increased after the ZrO2 NT-coated samples were annealed at 200 and 400 °C.This work was supported by the National Research Foundation of Korea (grant number NRF-2020R1A4A1019074 ) and the Qatar National Research Fund, the Qatar Foundation, Doha, Qatar (grant number NPRP11S-0102-180178 ). The authors also would like to acknowledge University of Malaya and Sharif University of Technology for supporting this research.Scopu