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排序方式: 共有430条查询结果,搜索用时 18 毫秒
21.
In an unselected collective of 100 employees of a big concern the knowledge with regard to body weight, nutrition and nicotine abuse was studied and the eating habits as well as the principles of education connected with them were ascertained. Nearly all questioned persons knew their body weight. Half of them were able to indicate their ideal weight with a precision of +/- 10%. The rate of the considerably overweight persons in the collective showed a dependence on higher age and female sex. Among the questionees with secondary education more normalweight persons were found. The test persons were well informed about the disadvantages of overweight and controlled their body weight in two thirds of the cases at least once a week. They stated to have met the term "diet" above all in the mass media. About half of them were able to define the term "calorie" approximately precisely. The questionees, however, often underestimated the required caloric quantity, apparently without drawing conclusions. The caloric content of alcoholic drinks was underestimated. Beer ranked first among the consumed alcoholic drinks. Only one fifth of the test persons "reward" their children with sweets and wish that they eat up their dinner. About half of the questionees were smokers. One fourth had never smoked, while another fourth had given up smoking. Mostly cigarettes were consumed, although nearly all test persons regarded inhaling smoking as harmful. The sole knowledge of factors that have a detrimental effect on the state of health (e.g. overweight, smoking) seems to be not sufficient to lead a healthy life. Since the test persons are, however, willing to do something for their health it would be useful to concentrate adipose persons and smokers into groups that should be treated by behaviour therapy and be positively motivated. 相似文献
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Purpose. Recently, colloidal dispersions made of mixtures from solid and liquid lipids have been described to combine controlled-release characteristics with higher drug-loading capacities than solid lipid nanoparticles (SLNs). It has been proposed that these nanostructured lipid carriers (NLCs) are composed of oily droplets that are embedded in a solid lipid matrix. The present work investigates the structure and performance of NLCs.
Methods. Colloidal lipid dispersions were produced by high-pressure homogenization and characterized by laser diffraction, photon correlation spectroscopy, wide-angle x-ray scattering, and differential scanning calorimetry. Proton nuclear magnetic resonance spectroscopy and electron spin resonance experiments were performed to investigate the mobility of the components and the molecular environment of model drugs. Furthermore, a nitroxide reduction assay with ascorbic acid was conducted to explore the accessibility of the lipid model drug from the outer aqueous phase.
Results. Proton nuclear magnetic resonance spectra clearly demonstrate that NLC nanoparticles differ from nanoemulsions and from SLNs by forming a liquid compartment that is in strong interaction to the solid lipid. The electron spin resonance model drug was found to be accommodated either on the particle surface with close water contact (SLN) or additionally in the oil (NLC). The oil compartment must be localized on the particle surface, because it can be easily reached by ascorbic acid.
Conclusion. Neither SLN nor NLC lipid nanoparticles showed any advantage with respect to incorporation rate or retarded accessibility to the drug compared with conventional nanoemulsions. The experimental data let us conclude that NLCs are not spherical solid lipid particles with embedded liquid droplets, but they are rather solid platelets with oil present between the solid platelet and the surfactant layer. 相似文献
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Malchaire J Kampmann B Mehnert P Gebhardt H Piette A Havenith G Holmér I Parsons K Alfano G Griefahn B 《International archives of occupational and environmental health》2002,75(3):153-162
OBJECTIVE: To co-ordinate the work of the main European research teams in the field of thermal factors in order to develop and improve significantly the methods presently available for assessing the risks of heat disorders encountered during work in hot conditions. METHOD: Each item from the required sweat rate model was reviewed on the basis of the most recent literature. A database with 1,113 laboratory and field experiments, covering the whole range of hot working conditions, was assembled and used for the validation. RESULTS: Influence of clothing ensemble on heat exchange: methods and formulas were developed that take into account the dynamic effects associated with forced convection and the pumping effect associated with body movements and exercise. Prediction of the average skin temperature: the model used in the required sweat rate standard ISO 7933 was extended to cover more severe conditions with high radiation and high humidity and different clothing and take into account the rectal temperature for the prediction of the skin temperature. Criteria for estimating acceptable exposure times in hot work environments: criteria were reviewed and updated concerning the maximum increase in core temperature and the acceptable water loss, for acclimatised and nonacclimatised subjects. These limits are intended to protect 95% of the population. Measuring strategy: a strategy was developed to assess the risks in any working situation with varying conditions of climate, metabolic rate or clothing. A detailed methodology was developed in three stages: an "observation" method for the recognition of the conditions that might lead to thermal stress; an "analysis" method for evaluating the problem and optimising the solutions; and an "expert" method for in-depth analysis of the working situation when needed. Validation: the different results were used to prepare a revision of the interpretation procedure proposed in the ISO standard 7933. We validated the modified approaches using the database. This involved the whole range of conditions for which the model was extended, namely conditions with high and low radiation, humidity and air velocity as well as fluctuating conditions. Based on these results, the predicted heat strain model was developed: it is presently proposed as an ISO and CEN standard. 相似文献
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The influence of diabetes on the primary and long-term success rate after 145 local thrombolyses in peripheral arterial disease stages III and IV was evaluated. 75 patients suffered from thrombotic, 62 patients from embolic occlusions, with eight patients suffering from thrombangitis obliterans. Regarding the localisation of vascular occlusion 0.6% suffered under an occlusion of the iliacal artery, 21% of the femoral artery, 16% of the popliteal artery, 7% of the vessel of the lower limb and 55.4% showed a combined occlusion of the femoral- and popliteal artery and the artery of the lower limb. In cases of embolic occlusions only marginal differences could be observed, while the primary success-rate of thrombotic occlusions showed greater differences between both groups (75% vs. 91%). During the follow-up, no differences between both groups could be established (patency-rate of 79% for both groups). The same applies to the prognostic factors: peripheral run off, length, duration of occlusion and the clinical stage (Fontaine IIb to IV). The remarkable differences between diabetic and non-diabetic patients in cases of occlusions of more than 16 cm (66% vs. 88% in primary and 55% vs. 77% in long-term success) can be explained by the high percentage of diabetic patients with poor run-off and microangiopathy. Regarding the above parameters, primary and long-term results seemed to be less in diabetic patients, even though a long-term patency could be observed in 2/3 of diabetic patients in stages IIb and IV with primary success. 相似文献
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Alpha-lipoic acid in the treatment of diabetic polyneuropathy in Germany: current evidence from clinical trials. 总被引:4,自引:0,他引:4
D Ziegler M Reljanovic H Mehnert F A Gries 《Experimental and clinical endocrinology & diabetes》1999,107(7):421-430
Diabetic neuropathy represents a major health problem, as it is responsible for substantial morbidity, increased mortality, and impaired quality of life. Near-normoglycaemia is now generally accepted as the primary approach to prevention of diabetic neuropathy, but is not achievable in a considerable number of patients. In the past two decades several medical treatments that exert their effects despite hyperglycaemia have been derived from the experimental pathogenetic concepts of diabetic neuropathy. Such compounds have been designed to improve or slow the progression of the neuropathic process and are being evaluated in clinical trials, but with the exception of alpha-lipoic acid (thioctic acid) which is available in Germany, none of these drugs is currently available in clinical practice. Here we review the current evidence from the clinical trials that assessed the therapeutic efficacy and safety of thioctic acid in diabetic polyneuropathy. Thus far, 15 clinical trials have been completed using different study designs, durations of treatment, doses, sample sizes, and patient populations. Within this variety of clinical trials, those with beneficial effects of thioctic acid on either neuropathic symptoms and deficits due to polyneuropathy or reduced heart rate variability resulting from cardiac autonomic neuropathy used doses of at least 600 mg per day. The following conclusions can be drawn from the recent controlled clinical trials. 1.) Short-term treatment for 3 weeks using 600 mg of thioctic acid i.v. per day appears to reduce the chief symptoms of diabetic polyneuropathy. A 3-week pilot study of 1800 mg per day given orally indicates that the therapeutic effect may be independent of the route of administration, but this needs to be confirmed in a larger sample size. 2.) The effect on symptoms is accompanied by an improvement of neuropathic deficits. 3.) Oral treatment for 4-7 months tends to reduce neuropathic deficits and improves cardiac autonomic neuropathy. 4.) Preliminary data over 2 years indicate possible long-term improvement in motor and sensory nerve conduction in the lower limbs. 5.) Clinical and postmarketing surveillance studies have revealed a highly favourable safety profile of the drug. Based on these findings, a pivotal long-term multicenter trial of oral treatment with thioctic acid (NATHAN I Study) is being conducted in North America and Europe aimed at slowing the progression of diabetic polyneuropathy using a clinically meaningful and reliable primary outcome measure that combines clinical and neurophysiological assessment. 相似文献
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R H Müller S A Runge V Ravelli A F Thünemann W Mehnert E B Souto 《European journal of pharmaceutics and biopharmaceutics》2008,68(3):535-544
Solid lipid nanoparticles (SLN) were produced loaded with cyclosporine A in order to develop an improved oral formulation. In this study, the particles were characterized with regard to the structure of the lipid particle matrix, being a determining factor for mode of drug incorporation and drug release. Differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) measurements were employed for the analysis of the polymorphic modifications and mode of drug incorporation. Particles were produced using Imwitor 900 as lipid matrix (the suspension consisted of 10% particles, 8% Imwitor 900, 2% cyclosporine A), 2.5% Tagat S, 0.5% sodium cholate and 87% water. DSC and WAXS were used to analyse bulk lipid, bulk drug, drug incorporated in the bulk and unloaded and drug-loaded SLN dispersions. The processing of the bulk lipid into nanoparticles was accompanied by a polymorphic transformation from the beta to the alpha-modification. After production, the drug-free SLN dispersions converted back to beta-modification, while the drug-loaded SLN stayed primarily in alpha-modification. After incorporation of cyclosporine A into SLN, the peptide lost its crystalline character. Based on WAXS data, it could be concluded that cyclosporine is molecularly dispersed in between the fatty acid chains of the liquid-crystalline alpha-modification fraction of the loaded SLN. 相似文献
30.