Nano-Hydroxyapatite and Nano-Hydroxyapatite/Zinc Oxide Scaffold for Bone Tissue Engineering Application

This research aims to evaluate the mechanical properties, biocompatibility, and degradation behavior of scaffolds made of pure hydroxyapatite (HA) and HA‐modified by ZnO for bone tissue engineering applications. HA and ZnO were developed using sol‐gel and precipitation methods respectively. The scaffolds properties were characterized using X‐ray diffraction (XRD), Fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), atomic absorption (AA), and atomic force microscopy (AFM). The interaction of scaffold with cells was assessed using in vitro cell proliferation and alkaline phosphatase (ALP) assays. The obtained results indicate that the HA/ZnO scaffolds possess higher compressive strength, fracture toughness, and density—but lower hardness—when compared to the pure HA scaffolds. After immersing the scaffold in the SBF solution, more deposited apatite appeared on the HA/ZnO, which results in the rougher surface on this scaffold compared to the pure HA scaffold. Finally, the in vitro biological analysis using human osteoblast cells reveals that scaffolds are biocompatible with adequate ALP activity

Deep analysis of perception through dynamic structures that emerge in cortical activity from self-regulated noise

The statistical properties of the spontaneous background electrocorticogram (ECoG) were modeled, starting with random numbers, constraining the distributions, and identifying characteristic deviations from randomness in ECoG from subjects at rest and during intentional behaviors. The ECoG had been recorded through 8 × 8 arrays of 64 electrodes, from the surfaces of auditory, visual, or somatic cortices of 9 rabbits, and from the inferotemporal cortex of a human subject. Power spectral densities (PSD) in coordinates of log10 power versus log10 frequency of ECoG from subjects at rest usually conformed to noise in power-law distributions in a continuum. PSD of ECoG from active subjects usually deviated from noise in having peaks in log10 power above the power-law line in various frequency bands. The analytic signals from the Hilbert transform after band pass filtering in the beta and gamma ranges revealed beats from interference among distributed frequencies in band pass filtered noise called Rayleigh noise. The beats were displayed as repetitive down spikes in log10 analytic power. Repetition rates were proportional to filter bandwidths for all center frequencies. Resting ECoG often gave histograms of the magnitudes and intervals of down spikes that conformed to noise. Histograms from active ECoG often deviated from noise in Rayleigh distributions of down spike intervals by giving what are called Rice (Mathematical analysis of random noise—and appendixes—technical publications monograph B-1589. Bell Telephone Labs Inc., New York, 1950) distributions. Adding power to noise as signals at single frequencies simulated those deviations. The beats in dynamic theory are deemed essential for perception, by gating beta and gamma bursts at theta rates through enhancement of the cortical signal-to-noise ratio in exceptionally deep down spikes called null spikes

Hydroxyl radical-aided thermal pretreatment of algal biomass for enhanced biodegradability

BACKGROUND: Algal biomass, known as a potential feedstock for biofuel production, has cell wall structures that differ from terrestrial biomass. The existing methods for processing algae are limited to conventional pretreatments for terrestrial biomass. RESULTS: In this study, we investigated a novel hydroxyl radical-aided approach for pretreating different types of algal biomass. In this process, hydroxyl radicals formed by a Fenton system were employed in combination with heating to alter the crystalline structure and hydrogen bonds of cellulose in the algal biomass. FeSO(4) and H(2)O(2) at low concentrations were employed to initiate the formation of hydroxyl radicals. This method releases trapped polysaccharides in algal cell walls and converts them into fermentable sugars. The effects of temperature, time, and hydroxyl radical concentration were analyzed. The optimal pretreatment condition [100 °C, 30 min, and 5.3 mM H(2)O(2) (determined FeSO(4) concentration of 11.9 mM)] was identified using a central composite design. Complete (100 %) carbohydrate recovery was achieved with some algal biomass without formation of inhibitors such as hydroxymethylfurfural and furfural as by-products. Both microalgal and macroalgal biomasses showed higher enzymatic digestibility of cellulose conversion (>80 %) after the milder pretreatment condition. CONCLUSION: Hydroxyl radical-aided thermal pretreatment was used as a novel method to convert the carbohydrates in the algal cell wall into simple sugars. Overall, this method increased the amount of glucose released from the algal biomass. Overall, enhanced algal biomass digestibility was demonstrated with the proposed pretreatment process. The new pretreatment requires low concentration of chemical solvents and milder temperature conditions, which can prevent the toxic and corrosive effects that typically result from conventional pretreatments. Our data showed that the advantages of the new pretreatment include higher carbohydrate recovery, no inhibitor production, and lower energy consumption. The new pretreatment development mimicking natural system could be useful for biochemical conversion of algal biomass to fuels and chemicals. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13068-015-0372-2) contains supplementary material, which is available to authorized users

The psychosocial impact of home use medical devices on the lives of older people: a qualitative study

Background Increased life expectancy and the accompanying prevalence of chronic conditions have led to the focus and delivery of health care migrating from the hospital and into people’s homes. While previous studies have investigated the integration of particular types of medical devices into the home, it was our intention to describe how medical devices are integrated into the lives of older people. Methods Adopting a qualitative study design, 12 older people, who used medical devices in the home, took part in in-depth, semi structured interviews. In 7 of the interviews participants and their partners were interviewed together. These interviews were recorded, transcribed and analysed thematically. Results Two themes were constructed that describe how medical devices that are used in the home present certain challenges to older people and their partners in how the device is adopted and the personal adaptations that they are required to make. The first theme of 'self-esteem’ highlighted the psychological impact on users. The second theme of 'the social device' illustrated the social impact of these devices on the user and the people around them. Conclusions We found that these devices had both a positive and negative psychosocial impact on users’ lives. An improved understanding of these psychological and social issues may assist both designers of medical devices and the professionals who issue them to better facilitate the integration of medical devices into the homes and lives of older people

The impact of diabetes prevention on labour force participation and income of older Australians: an economic study

Background: Globally, diabetes is estimated to affect 246 million people and is increasing. In Australia diabetes has been made a national health priority. While the direct costs of treating diabetes are substantial, and rising, the indirect costs are considered greater. There is evidence that interventions to prevent diabetes are effective, and cost-effective, but the impact on labour force participation and income has not been assessed. In this study we quantify the potential impact of implementing a diabetes prevention program, using screening and either metformin or a lifestyle intervention on individual economic outcomes of pre-diabetic Australians aged 45-64. Methods. The output of an epidemiological microsimulation model of the reduction in prevalence of diabetes from a lifestyle or metformin intervention, and another microsimulation model, Health&WealthMOD, of health and the associated impacts on labour force participation, personal income, savings, government revenue and expenditure were used to quantify the estimated outcomes of the two interventions. Results: An additional 753 person years in the labour force would have been achieved from 1993 to 2003 for the male cohort aged 60-64 years in 2003, if a lifestyle intervention had been introduced in 1983; with 890 person years for the equivalent female group. The impact on labour force participation was lower for the metformin intervention, and increased with age for both interventions. The male cohort aged 60-64 years in 2003 would have earned an additional $30 million in income with the metformin intervention, and the equivalent female cohort would have earned an additional$25 million. If the lifestyle intervention was introduced, the same male and female cohorts would have earned an additional $34 million and$28 million respectively from 1993 to 2003. For the individuals involved, on average, males would have earned an additional $44,600 per year and females an additional$31,800 per year, if they had continued to work as a result of preventing diabetes. Conclusions: In addition to improved health and wellbeing, considerable benefits to individuals, in terms of both additional working years and increased personal income, could be made by introducing either a lifestyle or metformin intervention to prevent diabetes

Effectiveness and acceptability of progestogens in combined oral contraceptives – a systematic review

BACKGROUND: The progestogen component of oral contraceptives (OCs) has undergone changes since it was recognized that their chemical structure can influence the spectrum of minor adverse and beneficial effects. METHODS: The objective of this review was to evaluate currently available low-dose OCs containing ethinylestradiol and different progestogens in terms of contraceptive effectiveness, cycle control, side effects and continuation rates. The Cochrane Controlled Trials Register, MEDLINE and EMBASE databases were searched. Randomized trials reporting clinical outcomes were considered for inclusion and were assessed for methodological quality and validity. RESULTS: Twenty–two trials were included in the review. Eighteen were sponsored by pharmaceutical companies and in only 5 there was an attempt for blinding. Most comparisons between different interventions included one to three trials, involving usually less than 500 women. Discontinuation was less with second-generation progestogens compared to first–generation (RR 0.79; 95% CI 0.69–0.91). Cycle control appeared to be better with second-compared to first-generation progestogens for both, mono-and triphasic preparations (RR 0.69; 95% CI 0.52–0.91) and (RR 0.61; 95% CI 0.43–0.85), respectively. Intermenstrual bleeding was less with third- compared to second-generation pills (RR 0.71; 95% CI 0.55–0.91). Contraceptive effectiveness of gestodene (GSD) was comparable to that of levonorgestrel (LNG), and had similar pattern of spotting, breakthrough bleeding and absence of withdrawal bleeding). Drospirenone (DRSP) was similar compared to desogestrel (DSG) regarding contraceptive effectiveness, cycle control and side effects. CONCLUSION: The third- and second-generation progestogens are preferred over first generation in all indices of acceptability. Current evidence suggests that GSD is comparable to LNG in terms of contraceptive effectiveness and for most cycle control indices. GSD is also comparable to DSG. DRSP is comparable to DSG. Future research should focus on independently conducted well designed randomized trials comparing particularly the third- with second-generation progestogens

Vermiculite bio-barriers for Cu and Zn remediation: an eco-friendly approach for freshwater and sediments protection

The increase in heavy metal contamination in freshwater systems causes serious environmental problems in most industrialized countries, and the effort to find ecofriendly techniques for reducing water and sediment contamination is fundamental for environmental protection. Permeable barriers made of natural clays can be used as low-cost and eco-friendly materials for adsorbing heavy metals from water solution and thus reducing the sediment contamination. This study discusses the application of permeable barriers made of vermiculite clay for heavy metals remediation at the interface between water and sediments and investigates the possibility to increase their efficiency by loading the vermiculite surface with a microbial biofilm of Pseudomonas putida, which is well known to be a heavy metal accumulator. Some batch assays were performed to verify the uptake capacity of two systems and their adsorption kinetics, and the results indicated that the vermiculite bio-barrier system had a higher removal capacity than the vermiculite barrier (?34.4 and 22.8 % for Cu and Zn, respectively). Moreover, the presence of P. putida biofilm strongly contributed to fasten the kinetics of metals adsorption onto vermiculite sheets. In open-system conditions, the presence of a vermiculite barrier at the interface between water and sediment could reduce the sediment contamination up to 20 and 23 % for Cu and Zn, respectively, highlighting the efficiency of these eco-friendly materials for environmental applications. Nevertheless, the contribution of microbial biofilm in open-system setup should be optimized, and some important considerations about biofilm attachment in a continuous-flow system have been discussed.This work has been produced thanks to the collaboration of Dip.SA (University of Bologna) and IBB (University of Minho). A particular acknowledgment is due to Dr. E. Rosales. The work was partially financed by the FCT Strategic Project Pest-OE/EQB/LA0023 and the Project ‘‘BioEnv—Biotechnology and Bioengineering for a sustainable world,’’ co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER

Evaluation of anti-biofilm activity of acidic amino acids and synergy with ciprofloxacin on Staphylococcus aureus biofilms

Acidic amino acids, aspartic acid (Asp) and glutamic acid (Glu) can enhance the solubility of many poorly soluble drugs including ciprofloxacin (Cip). One of the mechanisms of resistance within a biofilm is retardation of drug diffusion due to poor penetration across the matrix. To overcome this challenge, this work set to investigate novel counter ion approach with acidic amino acids, which we hypothesised will disrupt the biofilm matrix as well as simultaneously improve drug effectiveness. The anti-biofilm activity of D-Asp and D-Glu was studied on Staphylococcus aureus biofilms. Synergistic effect of combining D-amino acids with Cip was also investigated as a strategy to overcome anti-microbial resistance in these biofilms. Interestingly at equimolar combinations, D-Asp and D-Glu were able to significantly disperse (at 20 mM and 40 mM) established biofilms and inhibit (at 10 mM, 20 mM and 40 mM) new biofilm formation in the absence of an antibiotic. Moreover, our study confirmed L-amino acids also exhibit anti-biofilm activity. The synergistic effect of acidic amino acids with Cip was observed at lower concentration ranges (<40 mM amino acids and <90.54 µM, respectively), which resulted in 96.89% (inhibition) and 97.60% (dispersal) reduction in CFU with exposure to 40 mM amino acids. Confocal imaging indicated that the amino acids disrupt the honeycomb-like extracellular DNA (eDNA) meshwork whilst also preventing its formation