A major barrier that limits degradation of the lignocellulosic materials during biogas production is the structure itself. Without pretreatment, enzymatic attack during hydrolysis is not effective ...and leads to a poor yield of biogas. Thus, in this study, the effect of extrusion as pretreatment on wheat straw and deep litter was evaluated. Five screw configurations of the extruder were tested, namely, mild kneading, long kneading, reverse, kneading and reverse, and kneading with reverse. Sugar availability and biogas potentials from extruded samples were examined. Energy consumption, barrel temperature, and residence time of samples during extrusion were measured. The results showed an increment in methane yields of about 4–29 and 1–16% of extruded samples after 28 and 90 days of anaerobic digestion, respectively. A strong positive correlation (R 2 = 0.70) was observed between ultimate sugar availability and methane yields at 28 days. Increases in sugar availability (7–42%) accelerate degradation of the biomasses at the early digestion phases, resulting in higher yield of methane. Extrusion was less effective on deep litter because of the soft texture and possibility of sugar hydrolysis during storage.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Lignocellulosic biomasses such as wheat straw are widely used as a feedstock for biogas production. However, these biomasses are mainly composed of a compact fibre structure and therefore, it is ...recommended to treat them prior to its usage for biogas production in order to improve their bioavailability. The aim of this work is to evaluate, in terms of performance stability, methane yield and economic feasibility, two different scenarios: a mesophilic codigestion of wheat straw and animal manure with or without a low-energy demand alkaline pre-treatment (0.08gKOHgTS−1of wheat straw, for 24h and at 25°C). Besides this, said pre-treatment was also analysed based on the improvement of the bioavailable carbohydrate content in the untreated versus the pre-treated wheat straw. The results pointed out that pre-treated wheat straw prompted a more stable performance (in terms of pH and alkalinity) and an improved methane yield (128% increment) of the mesophilic codigestion process, in comparison to the “untreated” scenario. The pre-treatment increased the content of cellulose, hemicellulose and other compounds (waxes, pectin, oil, etc.) in the liquid fraction, from 5% to 60%, from 11.5% to 39.1% TS and from 57% to 79% of the TS in the liquid fraction for the untreated and pre-treated wheat straws, respectively. Finally, the pre-treated scenario gained an energy surplus of a factor 13.5 and achieved a positive net benefit of 90.4€tVS-WS−1d−1, being a favourable case for an eventual scale-up of the combined process.
Display omitted
•Alkali pre-treatment increased the biodegradability of wheat straw.•Alkali pre-treatment increased digester stability and performance.•Alkali pre-treated wheat straw reaching higher methane yield•Alkali pre-treatment resulted in a positive energy balance.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Display omitted
The present study investigated the feasibility of using pilot-scale anaerobic filter to treat by-product liquid (brown juice, BJ) from grass protein extraction in a green biorefinery, ...and produce biogas via anaerobic digestion without co-digestion substrate. Prior to feed into the un-heated anaerobic filter reactor, the BJ was warmed up to 55−60 °C in order to maintain the digestion temperature. The influence of retention time and feeding frequencies were tested in order to optimize the overall performance. The study demonstrated that anaerobic filter is feasible for converting BJ to biogas. The specific CH production reached 230 mL gCOD−1 d −1 while up to 80 % of influent COD was removed within a hydraulic retention time of 5.5 days. In addition, higher feeding frequencies enhanced the process stability as it narrowed the temperature variation and decreased the instant impact on buffer capacity.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Anaerobic digestion (AD) is a process in which microorganisms, under oxygen-free conditions, convert organic matter into biogas and digestate. Normally, only 40–70% of biomass is converted into ...biogas; therefore, digestate still contains significant amounts of degradable organic matter and biogas potential. The recovery of this residual biogas potential could optimize substrate utilization and lower methane emissions during digestate storage and handling. Post-treatment methods have been studied with the aim of enhancing the recovery of biogas from digestate. This review summarizes the studies in which these methods have been applied to agricultural and wastewater digestate and gives a detailed overview of the existing scientific knowledge in the field. The current studies have shown large variation in outcomes, which reflects differences in treatment conditions and digestate compositions. While studies involving biological post-treatment of digestate are still limited, mechanical methods have been relatively more explored. In some cases, they could increase methane yields of digestate; however, the extra gain in methane has often not covered treatment energy inputs. Thermal and chemical methods have been studied the most and have yielded some promising results. Despite all the research conducted in the area, several knowledge gaps still should be addressed. For a more thorough insight of the pros and cons within post-treatment, more research where the effects of the treatments are tested in continuous AD systems, along with detailed economic analysis, should be performed.
•Danish Death Registry potentially overestimating deaths from prostate cancer.•Chart review was carried out for 670 deaths and compared to the death registry.•Chart review attributed 51.2% of deaths ...to prostate cancer.•Registry data attributed 57.0%–71.7% of deaths to prostate cancer.
Current knowledge of the validity of registry data on prostate cancer-specific death is limited. We aimed to determine the underlying cause of death among Danish men with prostate cancer, to estimate the level of misattribution of prostate cancer death, and to examine the risk of death from prostate cancer when accounting for competing risk of death.
We investigated a nationwide cohort of 15,878 prostate cancer patients diagnosed in 2010–2014; with 3343 deaths occurring through 2016. Blinded medical chart review was carried out for 670 deaths and compared to the national cause of death registry. Five death categories were defined: 1) prostate cancer-specific death, 2) other unspecified urological cancer death, 3) other cancer death 4) cardiovascular disease death, and 5) other causes of death. Competing risk analyses compared Cox cause-specific and Fine-Gray regression models.
Chart review attributed 51.2% of deaths to prostate cancer, 17.0% to cardiovascular disease, and 16.7% to other causes. The Danish Register of Causes of Death attributed 71.7% of deaths to prostate cancer when including all registered contributing causes of death, and 57.0% of deaths when including only the primary registered cause of death. The probability of death by prostate cancer was 10% at 2-year survival.
More than half of the deceased men in our study cohort died of their prostate cancer disease within a mean of 2.4 years of follow up. Data from the death registry is prone to misclassification, potentially overestimating the proportion of deaths from prostate cancer.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The objective of the present study was to evaluate the effect of dairy cow diets on feces composition and methane (CH4) potential from manure with emphasis on fat level and roughage type and compare ...these results with the corresponding enteric CH4 emission. In experiment 1 six different diets, divided into two fat levels (low and high) and three different roughage types (early cut grass silage, late cut grass silage and maize silage), were used. The high fat level was achieved by adding crushed rapeseed. In experiment 2, the influence of increasing the fat level by using three different types of rapeseed: rapeseed cake, whole seed and rapeseed oil against a low fat ration with no rapeseed fat supplementation was studied. The diet and fat level had a significant influence on feces composition and CH4 yield. In general, ultimate CH4 yields (B0) were 8–9% higher than the present international default values for diets without extra fat and in feces from diets with extra fat supply the yield was 25–31% higher. It was possible to predict the B0 value from feed and feces characteristics; in fact, the best correlation was obtained by including both feed and feces characteristics. Addition of crude fat to diets to dairy cows reduced enteric CH4 emission but at the same time increased CH4 potential from feces both in terms of organic matter in feces and dry matter intake which might lead to increasing emissions unless proper manure handling such as anaerobic digestion is included. Without subsequent anaerobic digestion to produce energy the positive effect achieved at cow level could be counteracted by increasing manure emissions.
•We model the methane potential from manure by diet and feces composition.•We correlate crude fat in faces with the methane potential.•Increasing fat in the diet increase the methane potential.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The perennial C4 grass miscanthus was evaluated for use as an energy crop for methane production when harvested green in the autumn. Miscanthus × giganteus (M. × giganteus) and Miscanthus sinensis ...(M. sinensis) were harvested on five occasions, from August to November 2012. Methane yields from stems and leaves were analysed using batch assay after 90 d digestion. Estimated dry matter yields were highest on 1st October for M. × giganteus and 13th September for M. sinensis. Cellulose and lignin contents were greater with M. × giganteus than M. sinensis and low lignin content in leaves led to rapid degradation during the early periods of anaerobic batch assay. After 90 d of anaerobic digestion, cumulative specific methane yields for M. × giganteus varied for stem and leaf from 285 to 333 and 286 to 314 Nl (normalised litre) kg−1 VS and 291 to 312 and 298 to 320 Nl kg−1 VS for M. sinensis. Estimated methane yields per ha were positively correlated with the dry matter yields of miscanthus (r = 0.92) and the optimal harvesting time was between September–October. Methane yield at optimal harvest time was estimated as 3.824 × 106 Nl ha−1 (stem) and 1.605 × 106 Nl ha−1 (leaf) for M. × giganteus and 3.507 × 106 Nl ha−1 (stem) and 2.957 × 106 Nl ha−1 (leaf) for M. sinensis. There was a discrepancy between the estimating dry matter yield by sampling single shoots and whole plot harvesting. This needs to be further investigated.
•Optimal harvesting time for miscanthus was between September and October.•Plant fractions had significant differences in the first 31 d of batch digestion.•Chemical compositions and methane production rates varied.•Significant correlation between methane yield per ha and dry matter yield.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•The risk of serious disease was 34% in patients referred to the diagnostic centre.•The diagnoses consisted of both malignant (12%) and non-malignant diseases (22%).•Patients presented with various ...symptoms and signs.•A multidisciplinary diagnostic approach is needed at the diagnostic centre.
Little is known about the clinical characteristics of patients referred to a diagnostic centre through the Danish urgent referral pathway for non-specific serious symptoms. We aimed at estimating the distribution of serious disease and the diagnostic value of clinical characteristics for the diagnosis of cancer and serious non-malignant disease in these patients.
A cohort study of 938 patients referred by their GP to the diagnostic centre at Silkeborg Regional Hospital. All patients were followed up for three months in national registries. The likelihood ratio (LR) of cancer or serious non-malignant disease were calculated in relation to clinical characteristics.
A total of 327 (34.9%) patients were diagnosed with new serious disease within three months: 118 patients (12.6%) with malignant disease and 209 patients (22.3%) with non-malignant disease. Most patients presented general symptoms. The highest LR of cancer was found for abdominal mass, high lactate dehydrogenase or abnormal findings in the diagnostic imaging. The highest LR of non-malignant disease was found for swollen joints or abnormal auscultation of lung or chest.
Patients referred by their GP to the diagnostic centre have high risk of serious disease. A multidisciplinary diagnostic approach is needed to embrace the diagnostic spectrum.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Campaigns aimed at raising cancer awareness and encouraging early presentation have been implemented in England. However, little is known about whether people with low cancer awareness and increased ...barriers to seeking medical help have worse cancer survival, and whether there is a geographical variation in cancer awareness and barriers in England.
From population-based surveys (n=35 308), using the Cancer Research UK Cancer Awareness Measure, we calculated the age- and sex-standardised symptom awareness and barriers scores for 52 primary care trusts (PCTs). These measures were evaluated in relation to the sex-, age-, and type of cancer-standardised cancer survival index of the corresponding PCT, from the National Cancer Registry, using linear regression. Breast, lung, and bowel cancer survival were analysed separately.
Cancer symptom awareness and barriers scores varied greatly between geographical regions in England, with the worst scores observed in socioeconomically deprived parts of East London. Low cancer awareness score was associated with poor cancer survival at PCT level (estimated slope=1.56, 95% CI: 0.56; 2.57). The barriers score was not associated with overall cancer survival, but it was associated with breast cancer survival (estimated slope=-0.66, 95% CI: -1.20; -0.11). Specific barriers, such as embarrassment and difficulties in arranging transport to the doctor's surgery, were associated with worse breast cancer survival.
Cancer symptom awareness and cancer survival are associated. Campaigns should focus on improving awareness about cancer symptoms, especially in socioeconomically deprived areas. Efforts should be made to alleviate barriers to seeking medical help in women with symptoms of breast cancer.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Danish cancer patients have lower survival rates than patients in many other western countries. Half of the patients present with non-alarm symptoms and thus have a long diagnostic pathway. ...Consequently, an urgent referral pathway for patients with non-specific serious symptoms was implemented throughout Denmark in 2011-2012. As part of the diagnostic workup, a panel of blood tests are performed for all patients referred by their general practitioner (GP) to the urgent referral pathway. In this study, we analysed the probability of being diagnosed with cancer in GP-referred patients with abnormal blood test results.
We performed a cohort study that included all patients aged 18 years or older referred by their GP to Silkeborg Regional Hospital for analysis of a panel of blood tests. All patients were followed for 3 months for a cancer diagnosis in the Danish Cancer Registry. The likelihood ratio and post-test probability of subsequently finding cancer were calculated in relation to abnormal blood test results.
Among the 1499 patients included in the study, 12.2% were subsequently diagnosed with cancer. The probability of cancer increased with the number of abnormal blood tests. Patients with specific combinations of two abnormal blood tests had a 23-62% probability of cancer. Only a few single abnormal blood tests were linked with a high post-test probability of cancer, and most abnormalities were not specific to cancer.
A number of specific abnormal blood tests and combinations of abnormal blood tests markedly increased the probability of cancer being diagnosed. Still, abnormal blood test results should be interpreted cautiously as most are non-specific to cancer. Thus, results from the blood test panel may strengthen the suspicion of cancer, but blood tests cannot be used as a stand-alone tool to rule out cancer.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
