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1.
Dejan Popovic Tessa Gordon Victor F. Rafuse Dr. Arthur Prochazka 《Annals of biomedical engineering》1991,19(3):303-316
Implanted wire electrodes are increasingly being used for the functional electrical stimulation of muscles in partially paralysed
patients, yet many of their basic characteristics are poorly understood. In this study we investigated the selectivity, recruitment
characteristics and range of control of several types of electrode in triceps surae and plantaris muscles of anaesthetized
cats. We found that nerve cuffs are more efficient and selective (i.e., cause less stimulus spread to surrounding muscles)
than intramuscular electrodes. Bipolar intramuscular stimulation was more efficient and selective than monopolar stimulation,
but only if the nerve entry point was between the electrodes. Monopolar electrodes are efficient and selective if located
close to the nerve entry point, but their performance declines with distance from it. Nonetheless, for a variety of reasons
monopolar stimulation provides the best compromise in many current applications. Short duration pulses offer the best efficiency
(least charge per pulse to elicit force) but high peak currents, increasing the risk of electrode corrosion and tissue damage.
Electrode size has little effect on recruitment and should therefore be maximised because this minimises current density. 相似文献
2.
Dejan Nikolic Yongmei Li Lucas R Chadwick Simonida Grubjesic Pia Schwab Peter Metz Richard B van Breemen 《Drug metabolism and disposition》2004,32(2):272-279
The female flowers of hops are used throughout the world as a flavoring agent for beer. Recently, there has been increasing interest in the potential estrogenic properties of hop extracts. Among the possible estrogenic compounds in hops, 8-prenylnaringenin is perhaps most significant due to its high in vitro potency exceeding that of other known phytoestrogens. Since data regarding the pharmacokinetic properties of this compound are lacking, we investigated the in vitro metabolism of 8-prenylnaringenin by human liver microsomes. A total of 12 metabolites were identified, and biotransformation occurred on the prenyl group and the flavanone skeleton. The major site of oxidation was on the terminal methyl groups, and of the two possible isomers, the transisomer was more abundant. The double bond on the prenyl group was also oxidized to an epoxide that was opened by intramolecular reaction with the neighboring hydroxyl group. On the flavanone skeleton, the major site of oxidation was at 3'position on the B ring. Other metabolites included oxidation at carbon-3 as well as desaturation of the C ring to produce 8-prenylapigenin. An unusual hydroxy quinone product formed by ipso hydroxylation of the B ring of 8-prenylnaringenin was also detected. This product was probably an intermediate for the B ring cleavage product, 8-prenylchromone. 相似文献
3.
Karen Marr Dejan Jakimovski Marcello Mancini Ellen Carl Robert Zivadinov 《Ultrasound in medicine & biology》2018,44(8):1762-1769
A consensus on venous flow quantification using echo spectral Doppler sonography is lacking. Doppler sonography data from 83 healthy individuals were examined using manually traced transverse cross-sectional area and diameter-derived cross-sectional area obtained in longitudinal view measurements of the internal jugular vein. Time-averaged velocity over a 4-s interval was obtained in the longitudinal plane using manual tracing of the waveform. Manual and computer-generated blood flow volume calculations were also obtained for the common carotid artery, for accuracy purposes. No differences were detected between semi-automated and manual blood flow volume calculations for the common carotid artery. The manual calculation method resulted in almost twofold larger venous internal jugular vein flow measurements compared with the semi-automated method. Doppler sonography equipment does not provide accurate automated calculation of venous size and blood flow. Until further technological development occurs, manual calculation of venous blood flow is warranted. 相似文献
4.
Uroš Rajkovič Marija Milavec Kapun Dejan Dinevski Vesna Prijatelj Marija Zaletel Olga Šušteršič 《Journal of medical systems》2016,40(9):198
Health documentation is a prerequisite for good and sustainable health and social care. It is especially important for patient involvement and their empowerment. A transition from paper to e-documentation together with the electronic patient record should be based on thorough knowledge of the current state of documentation and its usages. The main objective of this paper was to analyse which documents and work methods of documenting processes within nursing are being used within different environments. Furthermore, what are the main reasons for their discrepancies from theoretical approaches and best practices. The analysis is based on a survey carried out on all three levels of healthcare. The survey questionnaire consisted of 12 questions to which responded 286 nursing teams from community health centres, hospitals and retirement homes in Slovenia. The results point to diversity in documenting as well as lack of interoperability. This is reflected in a great number of different documents. All phases of the nursing process were being documented in only 31.8 % of cases. The main reasons for this can be attributed to work organisation, different definitions of data-set requirements and inadequate knowledge by nurses. Survey results pointed out a need for the renewal of nursing documentation towards a more uniform system based on contemporary health technologies. 相似文献
5.
Dejan Susic Bo Rønn Hansen Torben Bæk Hansen 《Journal of plastic surgery and hand surgery》2013,47(3):319-320
To find out if a non-invasive technique (ultrasonography) was able to identify a dislocated ligament of a metacarpophalangeal joint of the thumb with instability of the ulnar collateral ligament, 14 consecutive patients with clinical rupture of the ulnar collateral ligament were examined with ultrasono-graphy before the ligament was explored. At exploration all ligaments were ruptured, and only five out of the 14 were dislocated. Ultrasonography recognised only two of the dislocated ligaments, and in half of the 14 patients the ultrasound scan gave incorrect information about the position of the ligament. We conclude that ultrasonography is not adequate for identifying dislocated ulnar collateral ligaments of the metacarpophalangeal joint of the thumb, and exploration is indicated in those with clinical instability in which palpation either suggests a dislocated ligament or is inconclusive. 相似文献
6.
7.
Dejan Orlic Bernhard Reimers Goran Stankovic Nicola Corvaja Alaide Chieffo Flavio Airoldi Vassilis Spanos Luca Favero Carlo Di Mario Antonio Colombo 《Catheterization and cardiovascular interventions》2003,60(2):159-166
The purpose of this study was to evaluate the safety and efficacy of the new Fox Hollow atherectomy device (FHT) designed for more efficient and easier plaque removal. The FHT has short rigid section and low-profile cutter mounted on a monorail catheter. The FHT catheter was utilized in 77 patients with 98 lesions. Mean reference vessel diameter was 2.75 +/- 0.51 mm. Successful atherectomy with tissue retrieval was performed in 94 lesions (96%). Following atherectomy, mean diameter stenosis was reduced from 71.1% to 31.9% and further to 10.4% following adjunctive treatment. Angiographic complications were one coronary perforation and one adventitial staining, both successfully treated with prolong balloon inflation and stent implantation. Nine patients (11.7%) had in-hospital non-Q-wave myocardial infarction (MI). One patient died (1.3%) for noncardiac reasons and one had MI (1.3%) at 6-month follow-up. Target lesion revascularization was required in 13 (13.8%) lesions and target vessel revascularization in 15 (20.3%) patients. There was target vessel failure in 17 (23.0%) patients. Plaque debulking with the FHT catheter can be performed safely and effectively in relatively small vessels and complex lesions located in mid-distal artery segments with 6-month clinical outcome similar to prior atherectomy devices. 相似文献
8.
Jakimovski Dejan Benedict Ralph H. B. Weinstock-Guttman Bianca Ozel Osman Fuchs Tom A. Lincoff Norah Bergsland Niels Dwyer Michael G. Zivadinov Robert 《Journal of neurology》2021,268(7):2578-2588
Journal of Neurology - The relationship between visual impairment and cognitive performance in multiple sclerosis (MS) remains poorly understood. To determine associations between visual acuity and... 相似文献
9.
Bojan?V.?StimecEmail author Bjarte?T.?Andersen Stefan?R.?Benz Jean?H.?D.?Fasel Knut?M.?Augestad Dejan?Ignjatovic 《International journal of colorectal disease》2018,33(6):771-777
Background
The middle colic artery (MCA) is of crucial importance in abdominal surgery, for laparoscopic or open right and transverse colectomies. Against this background, a high number of reports concerning anatomical variations of the MCA have been published intended to contribute to the improvement of operative techniques for the treatment of colon cancer. Despite this extensive literature, briefly reviewed in the present paper, a course of the MCA posterior to the superior mesenteric vein, called a retromesenteric trajectory, has been related to only once, to the best of our knowledge.Methods
A total series of 507 patients included in two prospective trials concerning laparoscopic or open right colectomy for cancer between 2011 and 2017 are reported. The investigation included preoperative or postoperative multidetector-computed tomography angiography.Results
We found four (0.79%) cases of retromesenteric MCA. They all underwent meticulous image analysis with mesenteric vessels’ road mapping, detailed morphometry, and surgical validation which revealed that, apart from their course, those cases did not differ significantly from the rest of the series.Conclusion
This paper therefore documents the worth-knowing behavior causing considerable confusion for the operating surgeon unaware of the abnormality and shows its concrete impact on patient-tailored surgical practice, in particular for laparoscopic D3 colectomy (including the “uncinated process first” approach).10.
Jelena Ciric Dejan M. Petrovic Katja Loos 《Macromolecular chemistry and physics.》2014,215(10):931-944
Starch, glycogen, and cellulose are all around us. They are eaten and used on a daily basis but they are not understood completely. Even though these carbohydrates are simple, concerning their repeating unit, they are hard to characterize. In order to try to understand as much as possible about their structure and the relationship between their molecular structure and physical properties, it is very practical to create such polysaccharides, for instance enzymatically, characterize them, and use them as standards for the characterization of natural ones. Therefore, the main objective of this Trend article is to outline different enzymatic routes to such carbohydrates, possibilities for their characterization, and the characterization of natural ones. 相似文献