1,547 research outputs found

    Impact of exercise therapy in patients undergoing breast cancer treatment

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    Abstract (1. publication) Purpose The aim of this work was to investigate cardiorespiratory fitness in breast cancer patients at different time points of anti-cancer treatment. Patients and Methods Non-metastatic breast cancer patients (n=222, mean age 55 years) were categorized into four subgroups according to their treatment status. Cardiopulmonary exercise testing (CPET) was used to measure patients’ cardiorespiratory fitness, including oxygen delivery and metabolic muscle function. Testing was performed by bicycle ergometry, and maximal oxygen uptake (VO2peak) was measured. Heart rate during exercise at 50 watts (HR50) was assessed as a cardiocirculatory parameter and ventilatory threshold (VT) was used as an indicator of the O2 supply to muscle. Analysis of covariance was used to estimate the impact of different cancer treatments on cardiorespiratory fitness with adjustment for clinical factors. Results Submaximal measures were successfully assessed in 220 (99%) and 200 (90%) patients for HR50 and VT, while criteria for maximal exercise testing were met by 176 patients (79%), respectively. The mean VO2peak was 20.6±6.7 ml/kg/min, mean VT 10.7±2.9 ml/min/kg and mean HR50 112±16 beats/min. Chemotherapy was significantly associated with decreased VO2peak, with significantly lower adjusted mean VO2peak among patients post adjuvant chemotherapy compared to patients with no chemotherapy or those who just started chemotherapy regime (all p<0.01). Patients post adjuvant chemotherapy reached only 63% of the VO2peak level expected for their age- and BMI-category (mean VO2peak 15.5±4.8 ml/kg/min). Similarly, HR50 was significantly associated with treatment. However, VT was not associated with treatment. Conclusion Breast cancer patients have marked and significantly impaired cardiopulmonary function during and after chemotherapy. Hereby, chemotherapy appears to impair cardiorespiratory fitness by influencing the oxygen delivery system rather than impacting metabolic muscle function. Our findings underline the need of exercise training in breast cancer patients to counteract the loss of cardiorespiratory fitness during the anti-cancer treatment. Abstract (2. publication) Aim Muscle strength has been associated with a decreased mortality risk and reduced side-effects in oncologic patients. However, little is known about how muscle strength is affected by cancer therapy. We investigated muscle strength in breast cancer patients during treatment and also compared it with healthy individuals. Methods Breast cancer patients (N=255), staged 0-III, aged 54.4±9.4 years, were categorized into four groups according to their treatment status. Their muscle function was assessed with gold standard method by maximal isokinetic peak torque (MIPT) (60°/s, 180°/s) and maximal voluntary isometric contraction (MVIC) tests in lower and upper extremity muscle groups. Additionally, muscular fatigue index (FI%) and shoulder flexibility was evaluated. Healthy women (N=26), aged 53.3±9.8 were tested using the same method. Analysis of covariance was used to estimate the impact of different cancer treatments on muscle function with adjustment for various clinical and socio-demographic factors. Results Consistently lower muscle strength and higher FI% was measured in knee strength in patients after chemotherapy. On average, patients had up to 25% lower strength in lower extremities and 12-16% in upper extremities in MVIC and MIPT during cancer treatment compared to healthy women. No substantial difference between patient groups in shoulder strength, but significantly lower shoulder flexibility in patients with radical mastectomy was measured. No serious adverse events were reported. Conclusions Patients showed markedly impaired muscle strength after adjuvant therapy. The clinically relevant decrease underlines the need of exercise therapy as early as possible in order to prevent or counteract the loss of muscle function. Abstract (3. publication) Purpose Cancer survivors are recommended to perform 150 min/week of moderate or 75 min/week of vigorous aerobic exercise, but it remains unclear how moderate and vigorous intensities can be prescribed. Therefore, it was investigated whether and how intensity prescriptions for healthy adults by the American College of Sports Medicine (ACSM) need to be adapted for breast cancer survivors. Methods 52 breast cancer survivors (stage 0-III, age 52±9 years, BMI 25.4±3.5 kg/m2) performed cardiopulmonary exercise tests at the end of primary-therapy. Intensity classes defined as percentages of maximal heart rate (HRmax), heart rate reserve (HRR), and maximal oxygen uptake (VO2max) were compared to the ACSM’s intensity classes using oxygen uptake reserve as reference. Results The prescriptions for moderate and vigorous exercise intensities were significantly different between breast cancer survivors and healthy adults when using VO2max (moderate 50–66 vs. 46–63 and vigorous 67–91 vs. 64–90 %VO2max) or HRR (moderate 26–50 vs. 40–59 and vigorous 51–88 vs. 60–89 %HRR), but not when using HRmax (moderate 65–76 vs. 64–76 and vigorous 77–94 vs. 77–95 %HRmax). Conclusions In breast cancer survivors, intensity prescriptions for healthy adults result in considerably too intense training if HRR is used as guiding factor. Prescriptions using VO2max result in a slightly too low exercise intensity, whereas recommendations in percentages of HRmax appear valid. Abstract (4. publication) Background Exercise has been reported to decrease cancer-related fatigue and to increase quality of life (QoL) in various breast cancer populations. However, studies investigating exercise during radiotherapy or resistance training are scarce. We conducted a randomized controlled trial (BEST study) to assess the efficacy of 12-week resistance training on fatigue beyond possible psychosocial effects of a group-based intervention. Patients and methods One-hundred-sixty patients with breast cancer stage 0-III were randomly assigned to a 12-week progressive resistance training (2 times/week) or a 12-week relaxation control (2 times/week). Both interventions were group-based. The primary endpoint fatigue was assessed with a 20-item multidimensional questionnaire, QoL with EORTC questionnaires. Statistical analyses were based on analysis of covariance models for the individual changes from baseline to week 13. Results Adherence to the intervention program as well as the completion rate (97%) for the primary outcome variable fatigue were high. In intention-to-treat analyses for the N=155 patients, significant between-group mean differences (MD) favoring the exercise group were observed for general fatigue (P=0.044), especially for the subscale physical fatigue (MD= -0.8; 95% confidence interval = (-1.5, -0.2), P=0.013), but not for affective (P=0.91) or cognitive fatigue (P=0.65). For QoL, significantly larger improvements regarding the role function (P=0.035) and pain (P=0.040) were noted among exercisers compared to relaxation controls. Future perspective improved significantly stronger in the relaxation control group compared to the exercise group (P=0.047). Conclusions The 12-week resistance training program was a safe, feasible and efficacious strategy to improve cancer-related fatigue and components of QoL in breast cancer patients during adjuvant radiotherapy. As exercise was compared to another group-based intervention, results indicate that resistance training effects on fatigue and QoL go beyond psychosocial benefits, and that the clinically relevant overall benefit of resistance exercise compared to usual care can be assumed to be higher

    Sorption properties and reversibility of Ti(IV) and Nb(V)-fluoride doped-Ca(BH4)2-MgH2 system

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    Ajuts: The authors are grateful to the Marie-Curie European Research Training Network (Contract MRTN-CT-2006-03 5366/COSY)In the last decade, alkaline and alkaline earth metal tetrahydroborates have been the focuses of the research due to their high gravimetric and volumetric hydrogen densities. Among them, Ca(BH4)2 and the Ca(BH4)2 + MgH2 reactive hydride composite (RHC), were calculated to have the ideal thermodynamic properties which fall within the optimal range for mobile applications.In this study, the addition of NbF5 or TiF4 to the Ca(BH4)2 + MgH2 reactive hydride composite system was attempted aiming to obtain a full reversible system with the simultaneous supression of CaB12H12. Structural characterization of the specimens was performed by means of in-situ Synchroton Radiation Power X-ray diffraction (SR-PXD) and 11B {1H} Solid State Magic Angle Spinning-Nuclear Magnetic Resonance (MAS-NMR). The evolution of the chemical state of the Nb- and Ti-based additives was monitored by X-ray Absorption Near Edge Structure (XANES). The addition of NbF5 or TiF4 to the Ca(BH4)2 + MgH2 system have not supressed completely the formation of CaB12H12 and only a slight improvement concerning the reversible reaction was displayed just in the case of Nb-doped composite materia

    CME liftoff with high-frequency fragmented type II burst emission

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    Aims: Solar radio type II bursts are rarely seen at frequencies higher than a few hundred MHz. Since metric type II bursts are thought to be signatures of propagating shock waves, it is of interest to know how these shocks, and the type II bursts, are formed. In particular, how are high-frequency, fragmented type II bursts created? Are there differences in shock acceleration or in the surrounding medium that could explain the differences to the "typical" metric type IIs? Methods: We analyse one unusual metric type II event in detail, with comparison to white-light, EUV, and X-ray observations. As the radio event was associated with a flare and a coronal mass ejection (CME), we investigate their connection. We then utilize numerical MHD simulations to study the shock structure induced by an erupting CME in a model corona including dense loops. Results: Our simulations show that the fragmented part of the type II burst can be formed when a coronal shock driven by a mass ejection passes through a system of dense loops overlying the active region.To produce fragmented emission, the conditions for plasma emission have to be more favourable inside the loop than in the interloop area. The obvious hypothesis, consistent with our simulation model, is that the shock strength decreases significantly in the space between the denser loops. The later, more typical type II burst appears when the shock exits the dense loop system and finally, outside the active region, the type II burst dies out when the changing geometry no longer favours the electron shock-acceleration.Comment: 7 pages, 9 figures, A&A accepte

    Factors influencing participation in a randomized controlled resistance exercise intervention study in breast cancer patients during radiotherapy

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    Background: Over the past years knowledge about benefits of physical activity after cancer is evolving from randomized exercise intervention trials. However, it has been argued that results may be biased by selective participation. Therefore, we investigated factors influencing participation in a randomized exercise intervention trial for breast cancer patients. Methods: Non-metastatic breast cancer patients were systematically screened for a randomized exercise intervention trial on cancer-related fatigue. Participants and nonparticipants were compared concerning sociodemographic characteristics (age, marital status, living status, travel time to the training facility), clinical data (body-mass-index, tumor stage, tumor size and lymph node status, comorbidities, chemotherapy), fatigue, and physical activity. Reasons for participation or declination were recorded. Results 117 patients (52 participants, 65 nonparticipants) were evaluable for analysis. Multiple regression analyses revealed significantly higher odds to decline participation among patients with longer travel time (p = 0.0012), living alone (p = 0.039), with more comorbidities (0.031), previous chemotherapy (p = 0.0066), of age ≥ 70 years (p = 0.025), or being free of fatigue (p = 0.0007). No associations were found with BMI or physical activity. By far the most frequently reported reason for declination of participation was too long commuting time to the training facility. Conclusions: Willingness of breast cancer patients to participate in a randomized exercise intervention study differed by sociodemographic factors and health status. Neither current physical activity level nor BMI appeared to be selective for participation. Reduction of personal inconveniences and time effort, e.g. by decentralized training facilities or flexible training schedules, seem most promising for enhancing participation in exercise intervention trials. Trial registration: Registered at ClinicalTrials.gov: NCT01468766 (October 2011)

    Longitudinal relations between teaching-related motivations and student-reported teaching quality

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    Teaching-related motivations are often assumed to influence teaching quality; however, the empirical evidence regarding the directionality of such influences is scarce. The present study thus examined the reciprocal links between teaching-related motivations (self-efficacy and enthusiasm for teaching) and student-reported teaching quality (classroom management, learning support, and cognitive activation). Two-level cross-lagged panel analyses across three time points (with an initial sample of 165 secondary- level mathematics teachers and their 4273 students) revealed no significant cross-lagged effects when teachers' stable inter-individual differences are taken into account. Our findings suggest that teachers' motivations are remarkably stable over time

    Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production

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    Bogen C, Al-Dilaimi A, Albersmeier A, et al. Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production. BMC Genomics. 2013;14(1): 926.BACKGROUND: Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strainof the genus Monoraphidium (SAG 48.87) was investigated in this work as apotential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated. RESULTS: Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category "carbohydrate metabolic process" and in "fatty acid biosynthetic process" in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance. CONCLUSIONS: The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts

    Review of the role of gut microbiota in mass rearing of the olive fruit fly, Bactrocera oleae, and its parasitoids

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    The olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is the major insect pest in commercial olive (Olea europaea L., Oleaceae) production worldwide. Its population management is largely based on the use of insecticides. However, concerns about the impact of insecticides on the environment and human health along with increasing resistance development calls for novel and environment-friendly approaches for population management. Integrated pest management programmes with a sterile insect technique (SIT) component and parasitoids are currently considered for the control of B. oleae. A major challenge for the development of such tools is mass rearing of both host and parasitoids. In this review, we consider the role of endogenous microbiota and its potential exploitation for improving the efficacy, quality, and cost effectiveness of mass rearing B. oleae as well as their parasitoids

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Managing Imbalanced Supply Chain Relationships for Sustainability: A Power Perspective

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    This study adopts a power perspective to investigate sustainable supply chain relationships and specifically uses resource dependence theory (RDT) to critically analyze buyer–supplier–supplier relationships. Empirical evidence is provided, extending the RDT model in this context. The concept of power relationships is explored through a qualitative study of a multinational company and agricultural growers in the UK food industry that work together to implement sustainable practices. We look at multiple triadic relationships involving a large buyer and its small suppliers to investigate how relative power affects the implementation of sustainable supply-management practices. The study highlights that power as dependence is relevant to understanding compliance in sustainable supply chains and to identifying appropriate relationship-management strategies to build more sustainable supply chains. We show the influences of power on how players manage their relationships and how it affects organizational responses to the implementation of sustainability initiatives. Power notably influences the sharing of sustainability-related risks and value between supply chain partners. From a managerial perspective, the study contributes to developing a better understanding of how power can become an effective way to achieve sustainability goals. This paper offers insights into the way in which a large organization works with small and medium size enterprises (SMEs) to implement sustainable practices and shows how power management—that is, the way in which power is used—can support or hinder effective cooperation around sustainability in the supply chain
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