434 research outputs found

    Der unbekannte Pionier: Ein neuer Sammelband dokumentiert die wegweisende Marx-Rezeption Alfred Schmidts

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    Alfred Schmidt / Michael Jeske und Bernard Görlich (Hg.): Marx als Philosoph: Studien in der Perspektive Kritischer Theorie. Springe: zu Klampen 2018. 978-38-66-74570-

    Neuromuscular performance of paretic versus non-paretic plantar flexors after stroke.

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    The objective of this study was to compare the neuromuscular function of the paretic and non-paretic plantar flexors (i.e. soleus, gastrocnemius medialis, lateralis) in chronic stroke patients. It was hypothesized that the contractile rate of force development (RFD) and neural activation, assessed by electromyogram (EMG) and V-waves normalized to the M-wave, and voluntary activation (twitch interpolation) would be reduced during plantar flexor maximum voluntary isometric contraction and that the evoked muscle twitch properties would be reduced in the paretic limb. Ten chronic stroke survivors completed the study. The main findings were that the paretic side showed deteriorated function compared to the non-paretic leg in terms of (1) RFD in all analyzed time windows from force onset to 250 ms, although relative RFD (i.e. normalized to maximum voluntary force) was similar; (2) fast neural activation (for most analyzed time windows), assessed by EMG activity in time windows from EMG onset to 250 ms; (3) V-wave responses (except for gastrocnemius medialis); (4) voluntary activation; (5) the evoked peak twitch force, although there was no evidence of intrinsic muscle slowing; (6) EMG activity obtained at maximal voluntary force. In conclusion, this study demonstrates considerable neuromuscular asymmetry of the plantar flexors in chronic stroke survivors. Effective rehabilitation regimes should be investigated

    Clinical Study Arm Crank and Wheelchair Ergometry Produce Similar Peak Oxygen Uptake but Different Work Economy Values in Individuals with Spinal Cord Injury

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    Objective. To study whether values for peak oxygen uptake (VO 2peak ) and work economy (WE) at a standardized workload are different when tested by arm crank ergometry (ACE) and wheelchair ergometry (WCE). Methods. Twelve paraplegic men with spinal cord injury (SCI) in stable neurological condition participated in this cross-sectional repeated-measures study. We determined VO 2peak and peak power output (PO peak ) values during ACE and WCE in a work-matched protocol. Work economy was tested at a standardized workload of 30 Watts (W) for both ACE and WCE. Results. There were no significant differences in VO 2peak (mL⋅kg −1 ⋅min −1 ) between ACE (27.3 ± 3.2) and WCE (27.4 ± 3.8) trials, and a Bland-Altman plot shows that findings are within 95% level of agreement. WE or oxygen consumption at 30 W (VO 2-30W ) was significantly lower during WCE compared to ACE ( < 0.039). Mean (95% CI) PO peak (W) were 130 (111-138) and 100 (83-110) during ACE and WCE, respectively. Conclusion. The findings in the present study support the use of both ACE and WCE for testing peak oxygen uptake. However, WE differed between the two test modalities, meaning that less total energy is used to perform external work of 30 W during wheelchair exercise when using this WCE (VP100 Handisport ergometer). Clinical Trials Protocol Record is NCT00987155/4.2007.2271

    Additive manufacturing of metal-bonded grinding tools

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    Grinding tools with superabrasive grains can be manufactured from different bond materials. In several industrial applications, metallic bond systems are used. In general, these show good grain retention and offer a high thermal conductivity, when compared to the other widely used bond types such as vitrified and resin bonds. One drawback of the metallic bond is the lack of pores in the grinding layer. This is caused by the manufacturing processes that are typically used, like brazing or hot pressing. These generally produce very dense layers. The high density and low porosity lead to comparatively little space for the transport of lubricant, coolant, and chips. One approach to eliminate this disadvantage is to introduce cavities into the grinding layer, using the laser powder bed fusion technique (LPBF). In order to evaluate the general suitability of LPBF in combination with the bond material and diamond grains, grinding layer samples with a nickel-titanium bond were produced. The abrasive behavior of these samples was tested in scratch tests on cemented carbide to verify the applicability as grinding tools. While the diamond grains in the powder mixture are not part of the fusion process, they also did not interfere with the manufacturing process, and the scratch tests showed promising abrasive capabilities. The grinding layer itself withstood the process forces, and no grain breakout could be observed. This indicates that the grain retention forces are high enough for the grinding process and that NiTi has a high potential as a bonding material for the manufacturing of grinding tools via LPBF

    MRI radiomic features are independently associated with overall survival in soft tissue sarcoma

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    Purpose: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. Methods and Materials: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell\u27s concordance index. Results: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; Conclusions: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS

    Somatostatin analogue scintigraphy: A simple and sensitive method for the in vivo visualization of Merkel cell tumors and their metastases

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    Abstract BACKGROUND: Trabecular carcinomas of the skin, or Merkel cell tumors, are aggressive neoplasms that tend to occur in sun-exposed skin. These tumors frequently metastasize and, despite therapy, the number of disease-related deaths is high. Ultrastructurally and immunocytochemically, the majority of these tumors have neuroendocrine characteristics. Recently, we described the in vivo visualization of various neuroendocrine tumors after injection of a radiolabeled somatostatin analogue (octreotide). In this study, we report the results of scintigraphy with radioactive-labeled somatostatin analogues in five patients with Merkel cell tumors. OBSERVATIONS: In all four patients in whom tumor was detected using computed tomographic scanning and ultrasound, the tumor sites were also demonstrated on octreotide scintigrams. In one patient, a tumor with a diameter that was smaller than 0.5 cm could not be detected with octreotide scintigraphy, computed tomography, or ultrasound. Using octreotide scintigraphy we found presumed tumor spots in two patients that were not evident when other techniques were used. CONCLUSIONS: Octreotide scintigraphy has an equal or even greater sensitivity than computed tomography and ultrasound for detecting Merkel cell tumors and their metastases. Establishing the spread of the disease in this way may ensure an optimal choice of treatment in patients with this type of tumor

    Innseiling til Borg havn – modellering av mudrings- og deponeringsoperasjoner - Spredning av finpartikulért materiale

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    Rapporten viser resultatene av en diagnostisk modellering av mudring og deponering ved en utdypning av innseilingen til Borg havn. I den pÄgÄende designfasen er det gjennomfÞrt modellering av turbiditet for Ä forutsi virkningen og omfanget av operasjonene. Turbiditetssimuleringene er gjort ved hjelp av SINTEFs partikkelbaserte DREAM-modell. DREAM-modellen bruker et detaljert datasett for strÞm generert av SINTEFs numeriske 3D-modell SINMOD. Datasettet dekker de hydrodynamiske forholdene i innseilingen til Borg havn fra 1. april til 8. oktober 2013. Borg havneomrÄde inneholder bÄde forurenset og ikke-forurenset sediment og stein. Basert pÄ omfattende feltmÄlinger ble lokalitetene av de forskjellige bunnmaterialene bestemt for to usikkerhetsnivÄer (konfidensintervall). PÄ grunn av de sensitive forholdene i Borg havneomrÄde og den planlagte store mudringen, ble egnede og validerte mudringsteknikker brukt i simuleringen. Turbiditetsverdier ble tatt fra internasjonal litteratur, felt- og laboratoriemÄlinger og tilpasset DREAM-modellen. Forventede effekter er bestemt med et akseptabelt nÞyaktighetsnivÄ. En indikasjon pÄ innvirkningen pÄ sÄrbare omrÄder er gitt. Det er lagt vekt pÄ at en god og miljÞrettet ledelse av mudringsarbeidene krever et grundig operativt overvÄkingsprogram under utfÞrelsen av arbeidene.publishedVersio

    The effect of supplementation with low doses of a cod protein hydrolysate on satiety hormones and inflammatory biomarkers in adults with metabolic syndrome: A randomized, double-blind study

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    Metabolic syndrome (MetS) is characterised by metabolic abnormalities that increase the risk of developing type 2 diabetes mellitus and cardiovascular disease. Altered levels of circulating ghrelin, several adipokines and inflammatory markers secreted from adipose tissue, such as leptin, adiponectin, tumor necrosis factor alpha, are observed in overweight and obese individuals. We assessed the effect of supplementation with low doses of a cod protein hydrolysate (CPH) on fasting and postprandial levels of acylated ghrelin, as well as fasting levels of adiponectin, leptin and inflammatory markers in subjects with MetS. A multicentre, double-blinded, randomized controlled trial with a parallel group design was conducted. Subjects received a daily supplement of CPH (4 g protein, n = 15) or placebo (0 g protein, n = 15). We observed no effect on fasting or postprandial levels of acylated ghrelin, fasting levels of adiponectin (p = 0.089) or leptin (p = 0.967) after supplementation with CPH, compared to placebo. Overall, our study showed that 8 weeks supplementation with a low dose of CPH in subjects with MetS had no effect on satiety hormones or most of the inflammatory markers, but the levels of high-sensitivity C-reactive protein were statistically significantly different in the CPH-group compared to placebo group. The robustness and clinical relevance of these findings should be explored in future studies with a larger sample size.publishedVersio
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