Vlažni zrak, kao neizbježna pojava u jamskoj atmosferi igra važnu ulogu, u definiranju klimatskih prilika i dopuštenih uvjeta okoline za normalan rad. Zasićenost zraka vlagom sprečava mogućnost ...odvođenja suvišne tjelesne topline procesom isparavanja, pa je zbog toga u rudarskoj praksi od izuzetnog značaja utvrđivanje relativne vlage, bilo direktnim ili indirektnim metodama.
Određivanje postotka vlage vrši se pomoću tablica, dijagrama ili proračunom, od kojih svaki navedeni način ima prednosti i nedostatke. .Klasičan proračun teče po Sprung-ovoj formuli, ali i u tom slučaju vrijednosti parcijalnih tlakova treba očitali iz tablica za vodenu para. Ovdje je prvi put prikazati novi način direktnog proračuna bez upotrebe tablica ili dijagrama, pri čemu se parcijalni tlakovi određuju na osnovu funkcionalne zavisnosti tlaka o temperaturi na graničnoj liniji.
Provider: - Institution: - Data provided by Europeana Collections- Steklovina in drugi pripomočki so bili potrebnipri mikroskopiranju, tehtanju in spravilu drobnih semen, odmerjanju kemičnih ...sredstev …- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Občutljivi stekleni predmeti so se uporabljali za shranjevanje, črpanje in prelivanje tekočin, za odmerjanje in mešanje kemičnih ...snovi ter vode.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We ...aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes.
We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident type 2 diabetes. We assessed the relative risk of type 2 diabetes prospectively for each cohort and lipid compartment separately using a prespecified analytic plan for exposures, covariates, effect modifiers, and analysis, and the findings were then pooled using inverse-variance weighted meta-analysis.
Participants were 39 740 adults, aged (range of cohort means) 49-76 years with a BMI (range of cohort means) of 23·3-28·4 kg/m
, who did not have type 2 diabetes at baseline. During a follow-up of 366 073 person-years, we identified 4347 cases of incident type 2 diabetes. In multivariable-adjusted pooled analyses, higher proportions of linoleic acid biomarkers as percentages of total fatty acid were associated with a lower risk of type 2 diabetes overall (risk ratio RR per interquintile range 0·65, 95% CI 0·60-0·72, p<0·0001; I
=53·9%, p
=0·002). The associations between linoleic acid biomarkers and type 2 diabetes were generally similar in different lipid compartments, including phospholipids, plasma, cholesterol esters, and adipose tissue. Levels of arachidonic acid biomarker were not significantly associated with type 2 diabetes risk overall (RR per interquintile range 0·96, 95% CI 0·88-1·05; p=0·38; I
=63·0%, p
<0·0001). The associations between linoleic acid and arachidonic acid biomarkers and the risk of type 2 diabetes were not significantly modified by any prespecified potential sources of heterogeneity (ie, age, BMI, sex, race, aspirin use, omega-3 PUFA levels, or variants of the FADS gene; all p
≥0·13).
Findings suggest that linoleic acid has long-term benefits for the prevention of type 2 diabetes and that arachidonic acid is not harmful.
Funders are shown in the appendix.
Tungsten-Based Catalysts for Selective Deoxygenation Gosselink, Robert W.; Stellwagen, Daniel R.; Bitter, Johannes H.
Angewandte Chemie (International ed.),
May 3, 2013, Letnik:
52, Številka:
19
Journal Article
Recenzirano
On the tip of the tung(sten): The title catalysts selectively perform deoxygenation of vegetable‐oil‐based feeds by either decarboxylation/decarbonylation or hydrodeoxygenation (HDO) pathways, ...depending on the dominant tungsten phase (WO3 and W2C). The process upgrades vegetable‐oil‐based feeds, under a hydrogen atmosphere, to high‐value olefinic products, thus providing a significant advantage over other types of deoxygenation catalysts.
Fusarium spp. are one of the most widespread mycotoxin-producing fungi in small-grain cereals like wheat. Their rate of infection and production of mycotoxins is mainly influenced by weather and ...pre-harvest agronomic measures. Consequently, farmers' prevention and control of mycotoxins are imperative since it is difficult to remove mycotoxins further down the cereal supply chain. This study aimed to (i) identify which pre-harvest preventive and control measures Dutch wheat farmers currently apply against Fusarium spp. infection and mycotoxin contamination and to (ii) examine which farm and farmer characteristics explain the implementation of these measures. Field data on pre-harvest measures, like the selection of resistant varieties, fungicide use, and crop rotation, along with farm and farmer characteristics were collected from Dutch wheat farmers via an online questionnaire. Probit models were applied to examine farm and farmer characteristics that explain the implementation of pre-harvest measures. Results showed that most farmers applied six or more different measures against Fusarium spp. infection and mycotoxin contamination in wheat and that the use of pre-harvest measures is related to at least one other measure. However, results indicated that about 44% of farmers could become more effective if they implemented a benchmark approach consisting of a combination of fungicide use during flowering, selection of a Fusarium resistant wheat variety, and plowing or crop rotation. Five out of the ten evaluated farm and farmer characteristics significantly (p < 0.05) explained the implementation of at least one of the eight pre-harvest control measures. These five farm and farmer characteristics include wheat as main income crop, the use of a decision support system, the education level of the farmer, the farmer's knowledge about mycotoxins, and the farmer's level of risk aversion. Insight into relevant characteristics can be used by farmer cooperatives, processing industries and government agencies to improve the overall mycotoxin management of wheat farmers.
•Most Dutch wheat farmers used at least six mycotoxin pre-harvest control measures.•The use of pre-harvest control measures was related to at least one other measure.•Fifty-six percent of farmers used an effective set of preventive control measures.•There are opportunities to enhance mycotoxin management by Dutch wheat farmers.•Five farm & farmer characteristics explained the implementation of control measures.
The fatty acid composition of serum cholesteryl esters is used as a qualitative biomarker of fatty acid intake, but quantitative data are scarce. Between 1987 and 1992, the authors fed various fatty ...acids in four controlled trials to 232 healthy Dutch volunteers and measured the proportion of fatty acids in participants' cholesteryl esters. Each 10% of energy fed as linoleic acid (18: 2) raised the proportion of linoleic acid in cholesteryl esters by 9.3 g per 100 g of fatty acids (standard deviation (SD) 3.1). For oleic acid (cis-18: 1), this figure was 6.5 g/100 g (SD 1.7); for trans fatty acids (frans-18: 1), it was 1.1 (SD 0.5); for stearic acid (18: 0), 1.0 (SD 0.4); for palmitic acid (16: 0), 1.7 (SD 0.5); for myristic acid (14: 0), 2.1 (SD 0.7); and for a mixture of saturated fatty acids (12: 0, 14: 0, and 16: 0), it was 2.2 g/100 g (SD 1.0). The coefficient of variation of the responses was fairly constant, indicating that changes in intake for each of these fatty acids can be monitored with similar precision. These data can be used to estimate the degree of compliance in experimental studies involving exchanges of single dietary fatty acids. Most fatty acids in cholesteryl esters may also be used in observational studies to estimate differences in intake. However, because of multiple simultaneous differences in fatty acid intake between free-living individuals and between populations, such data cannot provide information on absolute intake of fatty acids. Am J Epidemiol 1997; 145: 1114–22.
Membranes as a target for stress adaptation Russell, N.J.; Evans, R.I.; ter Steeg, P.F. ...
International journal of food microbiology,
12/1995, Letnik:
28, Številka:
2
Journal Article
Provider: - Institution: - Data provided by Europeana Collections- Paginarea: 198-199- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 ...Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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