1,432 research outputs found

    Techno-Economic Analysis of Biogas Production from Microalgae through Anaerobic Digestion

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    Microalgae are a promising feedstock for bioenergy due to higher productivity, flexible growing conditions, and high lipid/polysaccharide content compared to terrestrial biomass. Microalgae can be converted to biogas through anaerobic digestion (AD). AD is a mature technology with a high energy return on energy invested. Microalgae AD can bypass energy intensive dewatering operations that are associated with liquid fuel production from algae. A techno-economic assessment of the commercial feasibility of algae-based biogas production was conducted using Cyanothece BG0011 biomass as an example. BG0011 is a naturally occurring, saline cyanobacterium isolated from Florida Keys. It fixes atmospheric nitrogen and produces exopolysaccharide (EPS). Maximum cell density and EPS concentration of 2.7 and 2.1 g afdw1/L (for total algae biomass concentration of 4.8 g afdw/L) were obtained by air sparging. For an areal cell and EPS productivity of 12.4 and 9.6 g afdw/m2/day, respectively, the biomethane production cost was 14.8 /MMBtuusingcoveredanaerobiclagoonandhigh−pressurewaterscrubbingforbiogaspurification.Electricityproductionfrombiogascosts13cents/kwh.Ifarealproductivitywasincreasedby33/MMBtu using covered anaerobic lagoon and high-pressure water scrubbing for biogas purification. Electricity production from biogas costs 13 cents/kwh. If areal productivity was increased by 33% from the same system, by sparging air enriched with 1% CO2, then biomethane cost was reduced to 12.16 /MMBtu and electricity cost to 11 cents/kwh

    Help-seeking behaviors for female sexual dysfunction: a cross sectional study from Iran

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    <p>Abstract</p> <p>Background</p> <p>Female sexual dysfunctions (FSD) are prevalent multifactor problems that in general remain misdiagnosed in primary health care. This population-based study investigated help-seeking behaviors among women with FSD in Iran.</p> <p>Methods</p> <p>This was a cross sectional study carried out in Kohgilouyeh-Boyer-Ahmad province in Iran. Using quota sampling all sexually active women aged 15 and over registered in primary health care delivery centers were studied. Experience of sexual problems was assessed using an ad-hoc questionnaire (Female sexual dysfunction: help-seeking behaviors survey) containing 14 items. Trained female nurses interviewed all participants after a verbal informed consent. Data were analyzed in a descriptive manner.</p> <p>Results</p> <p>In all 1540 women were studied. Of these, 786 (51%) cases had experienced at least one of the FSD problems. Results showed that 35.8% of women with FSD had sought no professional help and the most reasons for not seeking help were identified as: 'time constraints' and believing that it 'did not occur to me' (39.1 and 28.5% respectively). Sixty one percent of women who sought help for FSD reported that 'doctor gave me a definite diagnosis' and 'a definite treatment plan was given' in 57% of cases.</p> <p>Conclusion</p> <p>The study findings indicated that FSD problems were prevalent and many women did not seek help for their problem. Finding 'time constraints' and believing that the problem 'did not occur to me' as the most cited reasons for not seeking help might facilitate to understand potential barriers that exist in recognition and treatment of the female sexual dysfunctions. Since FSD might have a negative impact on interpersonal relationships and women's quality of life, it seems that there is need to address the problem both at local and national primary health care services.</p

    Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index

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    <p>Abstract</p> <p>Background</p> <p>Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI).</p> <p>Methods and Results</p> <p>In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time), standard deviation (SD) of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (≤ 0.90 or ≥ 1.40) was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007). In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04). In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P < 0.01). None of the other indexes of BP variability were associated with ABI in univariate and multivariate analyses.</p> <p>Conclusion</p> <p>Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.</p

    Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

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    Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects

    Human Papilloma Virus vaccine and cervical cancer screening acceptability among adults in Quebec, Canada

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    <p>Abstract</p> <p>Background</p> <p>The Pap test has been used for cervical cancer screening for more than four decades. A human papillomavirus (HPV) vaccine has been approved for use in Canada and is commercially available now. These two preventive interventions should be considered simultaneously. General population support is an important factor for the successful combination of these interventions. The study had two objectives: 1) To assess practices, beliefs, and attitudes regarding Pap test screening and HPV immunization; 2) To identify socio-demographic factors for Pap screening and vaccine acceptability.</p> <p>Methods</p> <p>In 2006, 500 adults were invited to participate in a telephone survey in the region of Quebec City (urban and rural population, 600 000), Canada. Some neutral and standardized information on Pap test and HPV was provided before soliciting opinions.</p> <p>Results</p> <p>471 adults (18–69 year-olds) answered the questionnaire, the mean age was 45 years, 67% were female, and 65% had college or university degree. Eighty-six percent of women had undergone at least one Pap-test in their life, 55% in the last year, and 15% from 1 to 3 years ago. Among screened women, the test had been performed in the last three years in 100% of 18–30 year-olds, but only in 67% of 60–69 year-olds (P < 0.0001). Only 15% of respondents had heard of HPV. Eighty-seven percent agreed that HPV vaccines could prevent cervical cancer, 73% that the vaccine has to be administered before the onset of sexual activity, 89% would recommend vaccination to their daughters and nieces. Among respondents < 25 years, 91% would agree to receive the vaccine if it is publicly funded, but only 72% would agree to pay $100/dose.</p> <p>Conclusion</p> <p>There is an important heterogeneity in cervical cancer screening frequency and coverage. Despite low awareness of HPV infection, the majority of respondents would recommend or are ready to receive the HPV vaccine, but the cost could prevent its acceptability.</p
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