Magnetic resonance imaging of total body fat

In this study we assessed different magneticresonance imaging (MRI) scanning regimes and examined some of theassumptions commonly made for measuring body fat content by MRI. Wholebody MRI was used to quantify and study different body fat depots in 67 women. The whole body MRI results showed that there was a significant variation in the percentage of total internal, as well as visceral, adipose tissue across a range of adiposity, which could not be predicted from total body fat and/or subcutaneous fat.Furthermore, variation in the amount of total, subcutaneous, andvisceral adipose tissue was not related to standard anthropometricmeasurements such as skinfold measurements, body mass index, andwaist-to-hip ratio. Finally, we show for the first time subjects with apercent body fat close to the theoretical maximum (68%). This studydemonstrates that the large variation in individual internal fatcontent cannot be predicted from either indirect methods or directimaging techniques, such as MRI or computed tomography, on the basis ofa single-slice sampling strategy.

     

Comparative study of turbulent solid-liquid extraction methods for the determination of organochlorine pesticides

The aim of any extraction method in analytical chemistry is to effectively separate the analytes from the matrix with minimal solvent and time required. In this study, a comparison of the classical Soxhlet extraction and some new turbulent solid-liquid extraction techniques, such as fluidized-bed extraction (FBE), modified dive-in fluidized-bed extraction (dive-in FBE), modified dive-in Soxhlet extraction (dive-in SE) and dive-in thimble extraction (dive-in TE) for the determination of organochlorine pesticides (OCPs) was carried out. The turbulent extraction methods were performed by using the fexIKA vario control series extractor and by modification of the extraction system to dive-in technique, respectively. In addition, FBE and dive-in FBE were operated under the same, only for the FBE system established, optimum conditions. For the determination of the analytes a selective clean-up of the extracts followed by a gas chromatography (GC) method with mass spectrometric detection was used. All advanced extraction methods with reduced time and solvent consumption exhibited higher extraction efficiency than the standard procedure, Soxhlet extraction.     

Using automated flight mills to manipulate fat reserves in Douglas-fir beetles (Coleoptera: Curculionidae)

Because current techniques for quantifying fat, the main fuel used for flight in insects, are destructive, researchers are limited to only one direct measure of fat per specimen. This limitation is problematic for studies aimed at assessing whether fat loss through flight influences subsequent behavioral activity. To overcome this problem, we used body volume, body mass, emergence day, and brood density as parameters in a multiple regression model to predict initial fat levels in female Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, on emergence from the host. The model explained 54% of the variation in fat reserves as determined by Soxhlet extraction with petroleum ether. Treatments of 30-1,380 min of flight on rotary flight mills were used to establish the relationship between flight and fat reserves. Using a model that incorporated estimated initial fat levels, as well as time spent in flight and time in nonflight activities on the flight mills, we found that 6 h of flight decreased fat by approximately 50%. Flight activity and nonflight activity did not differ significantly in terms of their effect on fat reserves. Individual beetles with high initial fat content flew longer and faster on flight mills than beetles with low initial fat reserves. Our study shows how researchers can manipulate fat levels in bark beetles and other insects through flight, thereby opening the door to using these manipulations in behavioral studies.     

Energy balance of hibernating mouse-eared batMyotis myotis: a study with a TOBEC instrument

We used a non-invasive TOBEC method (Total Body Electric Conductivity) to estimate lean body mass and fat content in mouse-eared batsMyotis myotis (Borkhausen, 1797) hibernating in Poznañ Forts (W Poland) and in a semi-natural cave-mine Miedzianka (SE Poland). In December, fat content averaged 5.5 g in females (body mass = 29.4 g) and 5.3 g in males (body mass = 28.4 g). At the end of hibernation (April), fat content averaged 2.2 g in females (body mass = 25.6 g) and 1.4 g in males (body mass = 23.7 g). Fat content did not differ between the localities either in December or in April, but the pattern of changes of fat content was different. We calculated the rate of energy expenditure in hibernating bats using two methods, based on independent samples (fat content in first-time captured individuals) and based on paired observations (changes of fat content in re-captured individuals), and discussed problems associated with the two approaches. Both methods show that the bats need about 4.9 g of fat (191 kJ) to sustain a 165-day hibernation. However, the rate of fat usage varied considerably between the sites and hibernation phase. Although the average amount of fat remaining in April would be sufficient to support at least six more weeks of hibernation, the level of reserves was close to zero in some individuals.     

Effect of extraction method on the yield of furanocoumarins from fruits of Archangelica officinalis Hoffm

Optimal conditions for the extraction and analysis of furanocoumarins from fruits of Archangelica officinalis Hoffm. have been determined. The following extraction methods were used: exhaustive extraction in a Soxhlet apparatus, ultrasonication at 25 and 60 degrees C, microwave-assisted solvent extraction in open and closed systems, and accelerated solvent extraction (ASE). In most cases the yields of furanocoumarins were highest using the ASE method. The effects of extracting solvent, temperature and time of extraction using this method were investigated. The highest yield of furanocoumarins by ASE was obtained with methanol at 100-130 degrees C for 10 min. The extraction yields of furanocoumarins from plant material by ultrasonication at 60 degrees C and microwave-assisted solvent extraction in an open system were comparable to the extraction yields obtained in the time- and solvent-consuming exhaustive process involving the Soxhlet apparatus.     

Extraction Efficiency and HPLC Determination of Imidacloprid in Soil

Two extraction methods were successfully applied to study the extraction of imidacloprid from soil. The first method, using a mix of acetone and hexane, was based on Soxhlet extraction, and the second method, using acetonitrile, methanol, and water, was a modified version of a liquid extraction method. Quantification was performed by reversed-phase High Performance Liquid Chromatography (HPLC) with Diode Array Detection (DAD) at 270 nm using 40:60 (v/v) acetonitrile/water as a mobile phase. The mean recoveries for imidacloprid from soil ranged from 82.6 to 109%, with a relative standard deviation between 1.9 and 5.6% for both extraction methods. The detector linearity and the reproducibility of the method proved to be very precise. The limits of detection were 0.08 and 0.06 mg kg^?1 for liquid extraction and Soxhlet extraction, respectively. Overall, the efficiency of the Soxhlet extraction at lower concentrations was better than at higher concentrations, while liquid extraction proved efficient for all spiked levels. Liquid extraction performed better at higher concentrations compared to Soxhlet extraction. Taken together, our study suggests that the analysis of imidacloprid in soil can be performed with the modified liquid extraction method with a higher recovery and a lower RSD than Soxhlet extraction.     

A Rapid Method,Combining Microwave-Assisted Extraction and Gas Chromatography-Mass Spectrometry with a Database,for Determining Organochlorine Pesticides and Polycyclic Aromatic Hydrocarbons in Soils and Sediments

A rapid method for determining organochlorine pesticides and polycyclic aromatic hydrocarbons in soils and sediments was developed to allow pollution surveys to be performed in emergencies. The method involves microwave-assisted extraction and uses an automated identification/quantification system with a gas chromatography mass spectrometry database. A sample (3 g) is extracted with a 3:2 v/v hexane:water mixture (10 mL) for 30 min using a microwave-assisted extraction system at 120°C. The hexane extract is then cleaned using silica gel, then analyzed by gas chromatography mass spectrometry. The total analysis time is approximately 4 h. The precision of the quantitative results and accuracy of the analyte identification were determined. The total analyte concentrations were generally comparable to (61%–110% of) the concentrations determined using a Soxhlet extraction method, but the concentrations of individual high-molecular-weight polycyclic aromatic hydrocarbons were unacceptably low compared with the concentrations determined using the Soxhlet method. However, these compounds (e.g., benzo(ghi)perylene and indeno(1,2,3-cd)pyrene) were subsequently efficiently extracted using a hexane:water:ethanol mixture. The accuracy of identification was evaluated using accurate masses determined by gas chromatography time-of-flight mass spectrometry, and the mass error was 2 ppm for 21 of the 22 compounds identified using the new method.     

阔叶十大功劳叶与花总黄酮提取及含量测定

目的:研究阔叶十大功劳叶与花总黄酮的提取方法和含量测定。方法:比较以索氏提取法、超声波提取法和微波辅助提取法3种方法提取阔叶十大功劳叶与花中总黄酮,用亚硝酸钠-硝酸铝-氢氧化钠比色法测定总黄酮含量。结果:3种提取方法中,微波法提取效率最高,结果重现性好,并测得叶与花中总黄酮含量分别为2.182%和8.155%。结论:阔叶十大功劳总黄酮含量较高,总黄酮在花中的含量明显高于叶。     

四种真菌油脂提取方法的比较研究

采用索氏法、超临界CO2萃取法、酸热法和有机溶剂法分别提取雅致枝霉、拉曼被孢霉、少根根霉、畸雌腐霉和橙黄红酵母的油脂,从样品要求、最小样品量、仪器要求、处理样品能力及油脂得率等方面对4种提取方法进行综合评价,并对索氏法、超临界CO2萃取法和酸热法提取的雅致枝霉油脂的脂肪酸组成进行气相色谱分析。索氏法的油脂得率最高,但耗时较长;超临界CO2萃取法和酸热法的油脂得率相近,较索氏法略低,但酸热法更为简便,单位时间内样品处理能力强;有机溶剂法提取效果最差。我们建立的酸热法是一种适合油脂及多水饱和脂肪酸高产菌株筛选的简便、有效的真菌油脂提取方法。     

A classification scheme for scoring subcutaneous fat depots of shorebirds

ABSTRACT.   Different scoring systems have been developed for assessing fat stores in birds. Most have been used with passerines, and there is no widely used standard for studies of shorebirds. I developed a new fat-scoring classification scheme for shorebirds that was tested in Poland with juvenile Dunlins ( Calidris alpina ) during autumn and Wood Sandpipers ( Tringa glareola ) during spring migration. My proposed fatness scale is based on a qualitative assessment of the amount of fat in the axillary region and, if necessary, the furcular region. The resulting fat scores do not predict the actual amount of fat carried by a bird, but can be used to assign birds to a particular state of fatness and allow comparison of birds with different scores. Analysis revealed that the relationship between fat scores and predicted fat mass was approximately linear for both Dunlins and Wood Sandpipers. Although the scale I propose was tested with 20 species of shorebirds, sample sizes for larger species were small and consisted exclusively of lean and moderately fat birds. As a result, my proposed fat-scoring system should be evaluated using larger and fatter shorebirds because it has only been validated for one small and one medium-sized species.     

Are morphometric indices accurate indicators of stored energy in herring Clupea harengus?

The accuracy of the morphometric indices Fulton's K, somatic K and relative condition factor, K_n, as measures of individual North Sea herring Clupea harengus muscle fat content was investigated using the Distell Fish Fat meter. The accuracy of fat‐meter readings from an individual fish was validated by comparison with Soxhlet extraction analysis. The studies conducted demonstrated that Fulton's K is not consistently or strongly correlated with individual C. harengus muscle fat content, as defined by the fat‐meter estimates. The study shows that somatic K and K_n may be better indices of individual North Sea C. harengus muscle fat content than Fulton's K. These morphometric indices, however, should only be used after prior validation against a more direct measure of fat content.     

Multivariate optimisation of microwave-assisted extraction of capsaicin from Capsicum frutescens L. and quantitative analysis by 1H-NMR

A simple and rapid microwave-assisted extraction (MAE) procedure combined with 1H-NMR spectrometry was developed and optimised for the extraction and quantitative determination of capsaicin in Capsicum frutescens. The influence of experimental variables, including irradiation power, extraction temperature and dynamic extraction time before reaching the selected extraction temperature, on the performance of the extraction procedure was systematically studied using a Box-Behnken experimental design followed by a conventional central composite design approach. Statistical treatment of the results together with results from some additional experiments suggested optimum extraction conditions as 120 degrees C and 150 W, for 15 min with acetone as extractant. The optimised MAE method provides extracts that can be analysed quantitatively using 1H-NMR without any preliminary clean-up or derivatisation steps. In the 1H-NMR spectrum of the crude extracts the doublet signal in the delta range 4.349-4.360 ppm was well separated from other resonances in deuterated chloroform. The quantity of the compound was calculated from the relative ratio of the integral value of the target peak to that of a known amount of dimethylformamide as internal standard. In comparison with traditional Soxhlet extraction, the proposed method is less labour-intensive and provides a drastic reduction of extraction time and solvent consumption. In addition, MAE showed higher extraction yield and selectivity, with comparable reproducibility and recovery, relative to both conventional Soxhlet and sonication methods.     

Plumbagin recovery from field specimens of Drosophyllum lusitanicum (L.) link

The naphthoquinone plumbagin has a broad spectrum of biological activities. The aim of this study was to investigate the efficiency of two extraction methods (Soxhlet and ultrasound-assisted extraction) and three solvents (methanol, chloroform and hexane) to recover plumbagin from fresh and dried tissues of field specimens of Drosophyllum lusitanicum (L.) Link. The highest extraction yields were obtained with methanol as solvent and using fresh plant material. The obtained extracts were analysed by gas chromatography with mass spectrometric detection and plumbagin was the major compound present. Plumbagin was quantified in the extracts using the external standard methodology. The results obtained showed that the best recoveries of plumbagin were attained using fresh plant material and there were no significant differences between Soxhlet and ultrasound-assisted extraction. Moreover, hexane proved to be the more appropriate solvent for the extraction of plumbagin, providing high recoveries and the most concentrated extracts, yielding 2.42 mg of plumbagin per gram of plant material with the highest degree of purity. This method is a simple and efficient one to extract large amounts of plumbagin from D. lusitanicum field specimens.     

Isolation of chlorophylls and carotenoids from freshwater algae using different extraction methods

Usually marine algae are an excellent source of pigments for different commercial sectors. Freshwater macroalgae can be exploited as a good source of biologically active compounds provided an appropriate extraction method is developed. The efficiency of four methods, like microwave‐assisted (MAE), ultrasound‐assisted extraction (UAE), supercritical fluid extraction (SFE) with ethanol as a co‐solvent, as well as conventional Soxhlet extraction were studied in the same conditions (time, solvent and temperature) for the recovery of chlorophylls and carotenoids from three freshwater green algae species: Cladophora glomerata, Cladophora rivularis and Ulva flexuosa. UV‐Vis spectrophotometry was used to determine chlorophyll a, chlorophyll b and total carotenoid content in obtained extracts. The results of this study showed that the advantages of novel extraction techniques (MAE and UAE) include higher yield and, in consequence, lower costs compared to traditional solvent extraction techniques. These methods were much more efficient in freshwater green algae pigment recovery than the classic Soxhlet extraction as well as SFE.     

薇甘菊提取物对螺旋粉虱的生物活性

【背景】薇甘菊和螺旋粉虱均为我国入侵物种,且二者之间无寄生关系。本研究旨在挖掘薇甘菊的利用价值,为其在螺旋粉虱生态防控中的使用提供依据。【方法】采用药膜法和田间喷雾法,研究了4种提取方法（冷浸法、索氏提取法、冷浸—索氏提取法、温浸法）获得的薇甘菊提取物对螺旋粉虱成虫的室内生物活性和田间防治效果。【结果】在所选择的4种提取方法中,索氏提取法和温浸法的提取率最高,分别为9.90%和9.35%;冷浸—索氏提取法和冷浸法的提取率相对较低,分别为7.73%和4.50%。室内生物测定表明,采用冷浸法、冷浸—索氏提取法、索氏提取法和温浸法所获得的薇甘菊提取物对螺旋粉虱成虫的LC50值分别为8.94、9.03、6.32和7.51 mg·mL-1,但由于95%置信区间存在重合,不同提取物活性之间的差异不显著。田间试验结果则表明,不同提取方法获得的薇甘菊提取物对螺旋粉虱成虫都具有良好的防治效果,100倍液处理7 d后,对螺旋粉虱的校正防效均在75%以上。但是,索氏提取法和温浸法提取物防治效果显著优于冷浸—索氏提取法和冷浸法。【结论与意义】薇甘菊提取物对螺旋粉虱具有生物活性。     

A noninvasive method to determine fat content in small fish based on swim bladder size estimation

The presence of fat stores in fish is widely used as a correlate of fish health and fitness. Techniques to measure fat content with some accuracy are available for medium-sized and large fish, but apart from morphometric indices, a noninvasive method to determine fat content in small fish has hitherto been lacking. In this study, we introduce a novel method to measure the fat content in live fish that can be applied also to small fish of less than 0.5?g of body mass. This approach relies on a precise measurement of the swim bladder volume, from which fat content can subsequently be deduced. As fat is positively buoyant, fish with larger fat stores require a smaller swim bladder to attain neutral buoyancy. To determine swim bladder volume, we developed a measuring device, which makes use of the differential compressibility of air and water. A fish is placed in a pressure-tight chamber to which a standardized amount of water is added. The resulting change in pressure Δp is inversely proportional to the volume of the swim bladder. Using juveniles and adults of Simochromis pleurospilus (Nelissen, '78; Pisces: Tropheini) a small cichlid fish, we show that Δp is tightly related to structural size, mass, and body condition. Most importantly, this approach allows to predict the visceral fat content of small fish more precisely than the six most commonly used morphometric body indices.     

破壁马尾松花粉中脂肪酸的成分分析

以石油醚为溶剂,采用索氏抽提法提取破壁马尾松花粉中的粗脂肪,进行甲酯化处理,并用GC-MS技术对脂肪酸甲酯进行分离鉴定,共鉴定出11种脂肪酸;测定其相对含量,不饱和脂肪酸相对含量高达73.14%,其中亚油酸相对含量最高,达36.53%.     

A non-destructive morphometric technique for estimation of body and mesenteric lipid in Arctic charr: a case study of its application

Weight and eight linear measurements were made on Arctic charr from the domesticated Hammerfest strain from Norway and offspring of wild charr of a pelagic morph from Loch Rannoch, Scotland. Guts and mesenteries were removed from the Hammerfest charr only, and the amount of lipid in both carcass and mesenteries measured by Soxhlet extraction. Lipid was extracted from the whole body of the Loch Rannoch charr. Multiple regression analysis was used to derive morphometric predictors of total lipid for the Hammerfest charr and percentage body lipid for the Loch Rannoch charr, the regressions explaining 83 and 59% of variance respectively. For the Hammerfest charr, multiple regression also provided a reliable predictor of mesenteric fat, accounting for 65% of its variance. Hammerfest charr that exhibited high aggression rates had 53% more whole body lipid and 100% more mesenteric fat than those with low aggression rates, using direct measures of lipid levels. Indirect, morphometrically-derived measures of lipid levels gave almost identical results. It is concluded that morphometric techniques can provide estimates of both whole body and mesenteric lipid in studies requiring repeated measures on the same individuals.     

Optimisation of supercritical fluid extraction of indole alkaloids from Catharanthus roseus using experimental design methodology--comparison with other extraction techniques

Response surface modelling, using MODDE 6 software for Design of Experiments and Optimisation, was applied to optimise supercritical fluid extraction (SFE) conditions for the extraction of indole alkaloids from the dried leaves of Catharanthus roseus. The effects of pressure (200-400 bar), temperature (40-80 degrees C), modifier concentration (2.2-6.6 vol%) and dynamic extraction time (20-60 min) on the yield of alkaloids were evaluated. The extracts were analysed by high-performance liquid chromatography and the analytes were identified using ion trap-electrospray ionisation-mass spectrometry. The method was linear for alkaloid concentration in the range 0.18-31 microg/mL. The limits of detection and quantification for catharanthine, vindoline, vinblastine and vincristine were 0.2, 0.15, 0.1 and 0.08 microg/mL and 2.7, 2.0, 1.3 and 1.1 microg/g, respectively. The dry weight content of major alkaloids in the plants were compared using different extraction methods, i.e. SFE, Soxhlet extraction, solid-liquid extraction with sonication and hot water extraction at various temperatures. The extraction techniques were also compared in terms of reproducibility, selectivity and analyte recoveries. Relative standard deviations for the major alkaloids varied from 4.1 to 17.5% in different extraction methods. The best recoveries (100%) for catharanthine were obtained by SFE at 250 bar and 80 degrees C using 6.6 vol% methanol as modifier for 40 min, for vindoline by Soxhlet extraction using dichloromethane in a reflux for 16 h, and for 3',4'-anhydrovinblastine by solid-liquid extraction using a solution of 0.5 m sulphuric acid and methanol (3:1 v/v) in an ultrasonic bath for 3 h.     

温度和高脂食物对黑线仓鼠代谢产热和体脂累积的影响

能量代谢的适应性调节是小型哺乳动物应对环境季节性变化的主要策略之一。为探讨不同温度下动物在代谢产热能量支出与脂肪累积之间的权衡策略,以成年雄性黑线仓鼠为研究对象开展了3 个实验:实验1 将动物驯化于高脂和低脂食物;实验2 将动物暴露于低温(5℃)和暖温(30℃);实验3 将饲喂高脂食物的动物暴露于低温。以食物平衡法测定摄食量、摄入能和消化率,以开放式氧气分析仪测定代谢产热,以索氏抽提法测定脂肪含量。结果发现,取食高脂食物的黑线仓鼠摄食量显著减少,但脂肪累积显著增加;暖温下摄食量显著减少,但体脂含量显著增加,低温下摄食量显著升高,但体脂含量显著减少;饲喂高脂食物的黑线仓鼠在低温下摄入能显著增加,非颤抖性产热增强,但体脂含量显著降低。结果表明高脂食物对黑线仓鼠体脂累积的影响与环境温度有关,低温诱导脂肪动员,暖温促进脂肪贮存;低温下黑线仓鼠增加能量摄入不能完全补偿用于产热的能量支出,导致脂肪动员增加;暖温下代谢产热降低是脂肪累积的主要因素;与能量摄入相比代谢产热的能量支出在体脂累积的适应性变化中发挥更重要的作用。