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71.
U. Kster V. N. Fedoseyev V. I. Mishin L. Weissman M. Huyse K. Kruglov W. F. Mueller P. Van Duppen J. Van Roosbroeck P. Thirolf H. G. Thomas D. Weisshaar W. Schulze R. Borcea M. La Commara H. Schatz K. Schmidt S. Rttger G. Huber V. Sebastian K. L. Kratz R. Catherall U. Georg J. Lettry M. Oinonen H. L. Ravn H. Simon ISOLDE collaboration 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2000,160(4):528-535
Radioactive copper isotopes were ionized with the resonance ionization laser ion source (RILIS) at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d10 4s 2S1/2 – 3d10 4p 2P01/2 transition the low- and high-spin isomers of 70Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers (CVL) and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1+ ground state of 70Cu a magnetic moment of (+)1.8(3) μN and for the high-spin isomer of 70Cu a magnetic moment of (±)1.2(3) μN could be deduced. 相似文献
72.
Occurrence of antibiotics in the aquatic environment 总被引:62,自引:0,他引:62
The recent monitoring of drug residues in the aquatic environment has gained much interest as many pharmaceutical compounds can frequently be found in sewage treatment plant (STP) effluents and river water at concentrations up to several microgram/l. This article describes the analysis of various water samples for 18 antibiotic substances, from the classes of macrolid antibiotics, sulfonamides, penicillins and tetracyclines. Samples were preconcentrated via lyophilization and quantified using HPLC-electrospray-tandem-mass spectrometry. The investigated STP effluents and surface water samples showed frequent appearance of an erythromycin degradation product, roxithromycin and sulfamethoxazole with concentrations up to 6 micrograms/l. Neither tetracyclines nor penicillins could be detected at concentration levels above 50 and 20 ng/l, respectively. From the large number of ground water samples that were taken from agricultural areas in Germany, no contamination by antibiotics was detected except for two sites. This indicates that intake from veterinary applications to the aquatic environment is of minor importance. 相似文献
73.
Sigrid L?bell-Behrends Wolfgang B?se Sibylle Maixner Evamaria Kratz Matthias Kohl-Himmelseher Gerhard Marx Dirk W. Lachenmeier 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2011,6(3):385-393
An interdisciplinary team comprising experts in law, food chemistry and pharmacy, studied the requirements for food surveillance focusing on new forms of trade. In online marketing, the classification of products in categories that are regulated by food laws (i.e., foods, cosmetic products and other commodities) is often problematic, particularly for borderline products. In order to facilitate this classification based on the information provided online, we have established a decision tree. Moreover, existing regulations for sampling are only partially applicable to the new forms of marketing. It must be taken into account that sampling can be manipulated, if specimens are simply ordered by the responsible authority. Furthermore it is not feasible to leave behind samples for a supplementary expert opinion. Therefore a new policy framework is required that allows online sampling - anonymously in suspicious cases. Further suggestions include establishing a central register for online vendors as well as the necessity to present mandatory food information in a conspicuous place before the purchase is concluded. Future law amendments need to be implemented in a sophisticated manner taken into account the realities of online marketing. National regulations in Germany could be established prior to EU-wide regulations. Finally the legislative body must make sure not to privilege or penalize online vendors with respect to conventional trade. We propose complementary measures that include improved risk communication provisions for consumers as well as a certified seal of approval for registered businesses. 相似文献
74.
Minimally invasive surgery often requires devices that can change their geometry or shape when placed inside the body. Here, the potential of thermoplastic temperature‐memory polymers (TMP) for the design of intelligent devices, which can be programmed by the clinician to individually adapt their shifting geometry and their response temperature Tsw to the patient's needs, is explored. Poly(ω‐pentadecalactone) as hard segments and poly(?‐caprolactone) segments acting as crystallizable controlling units for the temperature‐memory effect (TME) are chosen to form multiblock copolymers PDLCL. These components are selected according to their thermal properties and their good biocompatibility. Response temperatures obtained under stress‐free and constant strain recovery can be systematically adjusted by variation of the deformation temperature in a temperature range from 32 °C to 65 °C, which is the relevant temperature range for medical applications. The working principle of TMP based instruments for minimally invasive surgical procedures is successfully demonstrated using three temperature‐memory catheter concepts: individually programmable TM‐catheter, an in‐situ programmable TM‐catheter, and an intelligent drainage catheter for gastroenterology. 相似文献
75.
76.
The E2 component of pyruvate dehydrogenase is engineered to form a caged, hollow dodecahedral protein assembly, and the feasibility of this scaffold to be used as a drug delivery system is examined by introducing cysteines to the internal cavity (D381C). The fluorescent dye Alexa Fluor 532 (AF532M) and the antitumor drug doxorubicin are coupled to this internal cavity through maleimides on the guest molecules. The viruslike particle's structure and stability remain intact after binding of the molecules within the interior of the nanocapsule. The pH-dependent hydrolysis of a hydrazone linkage to doxorubicin allows 90% drug release from the D381C scaffold within 72 h at pH 5.0. Fluorescence microscopy of MDA-MB-231 breast cancer cells indicates significant uptake of the D381C scaffold incorporating AF532M and doxorubicin, and suggests internalization of the nanoparticles through endocytosis. It is observed that the protein scaffold does not induce cell death, but doxorubicin encapsulated in D381C is indeed cytotoxic, yielding an IC(50) of 1.3 ± 0.3 μM. While the majority of particulate-based drug delivery strategies encapsulates drugs within polymeric nanoparticles, these results show the potential for using macromolecular protein assemblies. This approach yields a promising new opportunity for designing highly defined nanomaterials for therapeutic delivery. 相似文献
77.
78.
Ewa Janiszewska Izabela Kokot Agnieszka Kmieciak Zuzanna Stelmasiak Iwona Gilowska Ricardo Faundez Ewa Maria Kratz 《International journal of molecular sciences》2022,23(18)
Nearly 30% of infertility cases are caused by male factor. This study aimed at checking the associations between the sialylation degree of glycoprotein clusterin (CLU) and levels of oxidative–antioxidant balance markers in infertile men. Using lectin-ELISA with biotinylated lectins specific to α2,6-linked (Sambucus nigra agglutinin, SNA) and α2,3-linked (Maackia amurensis agglutinin, MAA) sialic acid (SA), the CLU sialylation in 132 seminal plasmas (SP) and 91 blood sera (BS) were analyzed. Oxidative–antioxidant status was measured by determining Sirtuin-3 (SIRT3), Sirtuin-5 (SIRT5), total antioxidant status (TAS), and ferric reducing antioxidant power (FRAP) levels. We indicate that multiple sperm disorders are associated with decreased expression of MAA-reactive SA in SP. Decreased SP SIRT3 concentrations may be associated with teratozoospermia and oligoasthenoteratozoospermia. ROC curve and cluster analysis revealed that SP relative reactivity of CLU glycans with MAA, the value of MAA/SNA ratio, and SIRT3 and SIRT5 concentrations may constitute an additional set of markers differentiating infertile oligoasthenoteratozoospermic patients (OAT) from normozoospermic (N), asthenoteratozoospermic (AT) and teratozoospermic (T). The multinomial logistic regression analysis confirmed the potential utility of SIRT3 determinations for differentiation between N and OAT groups as well as between N and T groups for SIRT3 and SIRT5. For BS, based on ROC curve and cluster analysis, relative reactivities of CLU glycans with SNA, MAA, SIRT3 and FRAP concentrations may be useful in the differentiation of normozoospermic patients from those with sperm disorders. The multinomial logistic regression analysis showed that the SNA relative reactivity with CLU glycans significantly differentiated the N group from AT, OAT and T groups, and FRAP concentrations significantly differed between N and AT groups, which additionally confirms the potential utility of these biomarkers in the differentiation of infertile patients with abnormal sperm parameters. The knowledge about associations between examined parameters may also influence future research aimed at seeking new male infertility therapies. 相似文献
79.
Bettina Lommel Willy Brüchle Klaus Eberhardt Willi Hartmann Annett Hübner Birgit Kindler Jens Volker Kratz Dirk Liebe Matthias Schdel Jutta Steiner 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,590(1-3):141
At GSI the gas-filled separator TASCA (TransActinide Separator and Chemistry Apparatus) was set up to investigate the chemical and physical properties of the heaviest elements making use of the highest beam intensities available [www.gsi.de/tasca; M. Schädel, D. Ackermann, A. Semchenkov, A. Türler, GSI Scientific Report 2005, GSI Report 2006-1, p. 262]. Appropriate backings and targets have to be developed.Conceivable backing materials are aluminium, titanium, and carbon. Aluminium backings and titanium backings in different thickness and from different companies are produced by cold rolling. Deposition by resistance heating is applied for carbon backings. For experiments in a chemically active atmosphere, beryllium has to be employed as backing, which is commercially available and produced by cold rolling.The task is to find the best material and thickness for backings to withstand two different processes: the electrodeposition, applied for the production of lanthanide and actinide targets at the Institut für Kernchemie, at the Universität Mainz [K. Eberhardt, et al., Contribution to this conference; D. Liebe, et al., Contribution to this conference], on the one hand, and deposition by thermal evaporation and sputtering on the other.We report on first tests with targets of uranium tetrafluoride (UF4) and metallic uranium on various backings. In addition, the behaviour and durability will be described for the different backing–target combinations in a C-beam and in an Mg beam. For the upcoming beam time U, 208PbS, 144Sm, 154Sm, and Gd are required. 相似文献
80.
EC Lai KJ Felice BW Festoff MJ Gawel DF Gelinas R Kratz MF Murphy HM Natter FH Norris SA Rudnicki 《Canadian Metallurgical Quarterly》1997,49(6):1621-1630
The objective of this study was to investigate the safety and efficacy of recombinant human insulinlike growth factor-I (rhIGF-I) in the treatment of sporadic ALS. A double-blind, placebo-controlled, randomized study of 266 patients was conducted at eight centers in North America. Placebo or rhIGF-I (0.05 mg/kg/day or 0.10 mg/kg/day) was administered for 9 months. The primary outcome measure was disease symptom progression, assessed by the rate of change (per patient slope) in the Appel ALS rating scale total score. The Sickness Impact Profile (SIP), a patient-perceived, health-related quality of life assessment, was a secondary outcome variable. Progression of functional impairment in patients receiving high-dose (0.10 mg/kg/day) rhIGF-I was 26% slower than in patients receiving placebo (p = 0.01). The high-dose treatment group was less likely to terminate the study due to protocol-defined markers of disease symptom progression, and members in this group exhibited a slower decline in quality of life, as assessed by the SIP. Patients receiving 0.05 mg/kg/day of rhIGF-I exhibited trends similar to those associated with high-dose treatment, suggesting a dose-dependent response. The incidence of clinically significant adverse experiences was comparable among the three treatment groups. Recombinant human insulin-like growth factor-I slowed the progression of functional impairment and the decline in health-related quality of life in patients with ALS with no medically important adverse effects. 相似文献