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1.
In vivo activation analysis has proved to be an analytical assay for the elemental composition of the human body. Applications have included the diagnosis of disease, the evaluation of therapeutic clinical interventions, the study of basic human physiology (especially of the aging process), and the development of reference standards for indirect measures of body composition. This paper will focus on the in vivo activation techniques currently in use and their future prospects, with an emphasis on body Ca, N, C and Cd. The prospects for delayed, prompt, and pulsed neutron activation will be included in the discussion.  相似文献   

2.
1 INTRODUCTION Bauxite porcelain is a novel “K2O–Al2O3–SiO2” system ceramic by using sintered bauxite, clay and potash feldspar and albite as the main raw materials with the Al2O3’s content of 50%~60(massfraction). Compared to the traditional“K2O–Al2O3–SiO2” feldspar porcelain by using quartz, bolus alb and potash feldspar and albite as the main raw materials, the bauxite porcelain possesses such advantages as high mechanical strength, excellent electrical insula- tion prop…  相似文献   

3.
This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract.  相似文献   

4.
The article is devoted to the element composition of the human body ash residue of some Russian cities. It presents the element composition of the human body ash residue, the distribution of elements in the ash residue depending on age and sex. The specific elements of different cities, showing the possible influence of the environmental conditions on the element composition of the human body ash residue. The main objective of this paper is to study the element composition of the human body ash residue and determine the regional characteristics. The methods of instrumental neutron activation analysis and inductively coupled plasma mass spectrometry were applied, an electronic microscope being used as a tool. The result of the research is 63 elements identified within in the human body ash residue. The issue is topical as it expands the knowledge of rare and radioactive elements within the human body and contributes to medicine, for example, by identifying the chemical elements to be included in a person's diet.  相似文献   

5.
Servais AC  Crommen J  Fillet M 《Electrophoresis》2006,27(13):2616-2629
The coupling of CE with MS detection, a relatively recent hyphenated technique, has gained increasing respect in the field of bioanalytical applications over the past few years. The first part of this review presents CE-MS applications dealing with drug bioanalysis, including forensic analysis and metabolism studies. Practical considerations to achieve a robust and sensitive CE-MS coupling are also presented. It is indeed essential to strictly control some critical electrospray parameters, such as the sheath liquid composition and flow rate, the nebulizing gas pressure as well as the capillary outlet position. The second part of the review critically describes the applications of CE coupled on-line to MS for the identification of biomarkers in body fluids for diagnostic purposes. Since the sample preparation procedures strongly differ according to the intended use (drug bioanalysis or biomarker discovery), they are discussed separately, taking into account the particular properties of plasma and urine matrices.  相似文献   

6.
The protein nature of soluble immune complexes (IC) from fresh plasma, cerebrospinal fluid (CSF), and urine was studied by combining several analytical and biochemical techniques. In plasma and CSF, free immunoglobulins G were separated from larger IC by gel filtration with a fast protein liquid chromatographic system. In urine, IC were separated by precipitation with polyethylene glycol. IC were further purified by protein-A and protein-G affinity chromatography and analyzed by two-dimensional gel electrophoresis. Apart from plasma samples from healthy donors, IC from cases with macrocreatine kinase type 1 and multiple sclerosis were analyzed. For CSF two cases of multiple sclerosis and for urine one case with urinary tract infection are shown. The method can be used for the examination of IC of unknown protein composition in body fluids.  相似文献   

7.
Complexation of iron(III), aluminum(III), and chromium(III) cations with monocarboxy cellulose was studied by potentiometric titration and IR spectroscopy. The composition and stability constants of the complexes were determined.  相似文献   

8.
Postbiotics are health-promoting microbial metabolites delivered as a functional food or a food supplement. They either directly influence signaling pathways of the body or indirectly manipulate metabolism and the composition of intestinal microflora. Cancer is the second leading cause of death worldwide and even though the prognosis of patients is improving, it is still poor in the substantial part of the cases. The preventable nature of cancer and the importance of a complex multi-level approach in anticancer therapy motivate the search for novel avenues of establishing the anticancer environment in the human body. This review summarizes the principal findings demonstrating the usefulness of both natural and synthetic sources of postbotics in the prevention and therapy of cancer. Specifically, the effects of crude cell-free supernatants, the short-chain fatty acid butyrate, lactic acid, hydrogen sulfide, and β-glucans are described. Contradictory roles of postbiotics in healthy and tumor tissues are highlighted. In conclusion, the application of postbiotics is an efficient complementary strategy to combat cancer.  相似文献   

9.
Potassium o-nitrophenolate (1) was reacted with various lanthanide trichlorides under different reaction conditions. By using the smaller lanthanides and working under rigorous exclusion of air, infinite chains of composition [(THF)4[K(o-O2N-C6H4-O)4Ln]4]n (Ln = Y (2a), Er (2b), Lu (2c)) were obtained. Using the same conditions but performing the crystallization under air, tetradecanuclear clusters of composition H18[Ln14(micro-eta2-o-O2N-C6H4-O)8(eta2-o-O2N-C6H4-O)16(micro4-O)2(micro3-O)16] (Ln = Dy (3a), Er (3b), Tm (3c), Yb (3d)) were isolated. Using larger center metals such as samarium, europium, and terbium and working under rigorous exclusion of air, infinite layers of composition [[K2(o-O2N-C6H4-O)5Tb]n] (4) and [[K2(o-O2N-C6H4-O)5Ln)]n] (Ln = Sm (5a), Eu (5b)) were obtained. In 4 the layers have a closer packing than those in compound 5. The closer packing is a result of the increased coordination number of the lanthanide metal and the potassium atoms. In contrast, the more open structures of 5 results in channels which are rectangular through the layers. All compounds reported including 1 have been investigated by single-crystal X-ray diffraction.  相似文献   

10.
Calculating body water through isotope dilution has become a useful way to nondestructively estimate body composition in many species. The most accurate estimates using this method require calibration against proximate chemical analysis of body composition for individual species, but no studies to our knowledge have calibrated this method on a hibernating mammal that seasonally undergoes dramatic changes in body composition. We use deuterium oxide to estimate total body water in captive arctic ground squirrels, Urocitellus parryii, and compare two approaches of calculating lean mass from total body water, both calibrated against lean mass based on proximate analysis. The first method uses a single tissue hydration constant to calculate lean mass from total body water; the second method uses a predictive equation to calculate lean mass from total body water and body mass. We found that the predictive equation performs better over the large range of body composition common to this species. Distillation of blood samples did not affect lean mass estimates from either calculation method. These findings indicate that isotope dilution using a predictive equation should work well as an alternative to destructive methods in other small mammals that undergo radical changes in body composition across their annual cycle.  相似文献   

11.
Vegetable oils (VOs), being our major dietary fat source, play a vital role in nourishment. Different VOs have highly contrasting fatty acid (FA) profiles and hence possess varying levels of health protectiveness. Consumption of a single VO cannot meet the recommended allowances of various FA either from saturated FA (SFA), monounsaturated FA (MUFA), polyunsaturated FA (PUFA), Ω-3 PUFAs, and medium-chain triglycerides (MCTs). Coconut oil (CO), flaxseed oil (FO), olive oil (OO), and sunflower oil (SFO) are among the top listed contrast VOs that are highly appreciated based on their rich contents of SFAs, Ω-3 PUFAs, MUFAs, and Ω-6 PUFA, respectively. Besides being protective against various disease biomarkers, these contrasting VOs are still inappropriate when consumed alone in 100% of daily fat recommendations. This review compiles the available data on blending of such contrasting VOs into single tailored blended oil (BO) with suitable FA composition to meet the recommended levels of SFA, MUFA, PUFA, MCTs, and Ω-3 to Ω-6 PUFA ratios which could ultimately serve as a cost-effective dietary intervention towards the health protectiveness and improvement of the whole population in general. The blending of any two or more VOs from CO, FO, OO, and SFO in the form of binary, ternary, or another type of blending was found to be very conclusive towards balancing FA composition; enhancing physiochemical and stability properties; and promising the therapeutic protectiveness of the resultant BOs.  相似文献   

12.
A mounting body of evidence suggests that changes in energetic conditions like prolonged starvation can be monitored using stable isotope ratios of tissues such as bone, muscle, hair, and blood. However, it is unclear if urinary stable isotope ratios reflect a variation in energetic condition, especially if these changes in energetic condition are accompanied by shifts in dietary composition. In a feeding experiment conducted on captive bonobos (Pan paniscus), we monitored urinary δ(13)C, δ(15)N, total C (carbon), total N (nitrogen), and C/N ratios and compared these results with glucocorticoid levels under gradually changing energy availability and dietary composition. Measurements of daily collected urine samples over a period of 31 days showed that while shifts in urinary isotope signatures of δ(13)C and δ(15)N as well as total C were best explained by changes in energy consumption, urinary total N excretion as well as the C/N ratios matched the variation in dietary composition. Furthermore, when correcting for fluctuations in dietary composition, the isotope signatures of δ(13)C and δ(15)N as well as total C correlated with urinary glucocorticoid levels; however, the urinary total N and the C/N ratio did not. These results indicate for the first time that it is possible to non-invasively explore specific longitudinal records on animal energetic conditions and dietary compositions with urinary stable isotope ratios and elemental compositions, and this research provides a strong foundation for investigating how ecological factors and social dynamics affect feeding habits in wild animal populations such as primates.  相似文献   

13.
The composition and percentage distribution of the sterols in preparations of the free (I), glycosylated (II), and esterified (III) sterols in the pulp of citrus fruits have been studied. In the sterol preparations, cholesterol, campesterol, stigmasterol, and β-sitosterol have been identified and detected, and three other sterols have been detected but not identified. It has been established that the sequences of the relative amounts of sterols in preparations (I), (II), and (III) of the grapefruit and the orange are similar and differ from that of mandarin pulp.  相似文献   

14.
The marine microalgaePhaeodactylum tricornutum, with a high lipid content constituting 20–60% of its dry weight under controlled growth conditions (1), has recently come into focus as a potentially rich source of dietary marine vegetable oil. In particular, this species has a characteristic high content of eicosapentenoic acid (EPA), which has potential benefits in human nutrition, since it cannot be synthesized in vivo in the human body. Some factors that could alter the biochemical composition ofPhaeodactylum tricornutum in favor of lipid production have been examinated in this study.  相似文献   

15.
Copper(II) complexes having the general composition Cu(L)(2)X(2) [where L = isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC), and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl(-), 1/2SO(4)(2-)] have been synthesized. All the Cu(II) complexes reported here have been characterized by elemental analyses, molar conductance, magnetic moment susceptibility, EI mass, (1)H NMR, IR, EPR, and electronic spectral studies. All the complexes were found to have magnetic moments corresponding to one unpaired electrons. The possible geometries of the complexes were assigned on the basis of EPR, electronic, and infrared spectral studies.  相似文献   

16.
陈然然  吴德华  王辛  龙成生 《色谱》2019,37(1):54-62
气相色谱-质谱法(GC-MS)是目前分析人体气味的主要技术手段,其不但可以分析人体气味的组成成分,还可以比较不同个体气味之间的差异。该文首先介绍了人体气味的提取和样品前处理的手段,随后对GC-MS在人体气味的采集及储存、成分分析及差异性研究、用于个体识别和健康表征等方面进行了综述,最后对GC-MS在人体气味分析中的发展趋势进行了展望。  相似文献   

17.
The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale (E(T)) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.  相似文献   

18.
The composition, structure, and adsorption behavior of activated carbons (ACs) derived from three different types of waste polymers, i.e., tire rubber (TR), polyvinyl chloride (PVC), and polyethyleneterephtalate (PET), by KOH activation were compared. The AC derived from PET exhibited the largest surface area (2831 m(2)/g) and pore volume (1.68 cm(3)/g) due to the homogenous aromatic composition of PET. The AC derived from PVC exhibited relatively lower surface area (2666 m(2)/g) but more narrowed pore size distribution (2-3 nm). The complex composition and high ash content of tire particles resulted in AC product with significantly lower surface area (398.5 m(2)/g) and heterogeneous pore width. Adsorption data of methylene blue (MB) were fitted well by Langmuir equation, indicating monolayer coverage on the ACs. The high oxygen content of PET-derived AC heavily affected its adsorption to MB and iodine. Due to the remarkable surface area and highly mesoporous structures, ACs based on both PET and PVC exhibited much higher adsorption capacities than that of TR and commercial coal-based AC (F400). This study demonstrates that the properties of ACs are highly dependent on their starting polymers and the potential of converting synthetic polymer waste into effective adsorbents for environmental remediation and cleanup.  相似文献   

19.
The terpolymerization of ethyl methacrylate (EMA), N‐phenylmaleimide (NPMI), and itaconic acid (IA) was investigated. The terpolymer composition was determined by elemental analysis and 1H NMR spectroscopy. The reactivity ratios of the three binary systems (EMA/NPMI, EMA/IA, and NPMI/IA) were calculated and used for the calculation of the terpolymer composition with the terminal model equations. A comparison between the experimental and theoretical compositions was made. The rate of the terpolymerization process was measured dilatometrically at two total monomer concentrations; this was done to establish the presence of intermolecular interactions between the investigated monomers. The thermal analysis of the obtained terpolymers was performed by thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3180–3187, 2003  相似文献   

20.
The paper compares the effects of various surface modifications, ion implantation, alkaline treatment and anodic oxidation, upon the corrosion resistance and bioactivity of titanium. The chemical composition of the surface layers thus produced was determined by XPS, SIMS and EDS coupled with SEM. The structure of the layers was examined by TEM, and their phase composition by XRD. The corrosion resistance was determined by electrochemical methods after the samples were exposed to the test conditions for 13 h. The bioactivity of titanium was evaluated in a simulated body fluid at a temperature of 37°C after various exposure time.  相似文献   

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