| 1. |
- Eisenberg, Tobias, et al.
(author)
-
Cardioprotection and lifespan extension by the natural polyamine spermidine
- 2016
-
In: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 22:12, s. 1428-1438
-
Journal article (peer-reviewed)abstract
- Aging is associated with an increased risk of cardiovascular disease and death. Here we show that oral supplementation of the natural polyamine spermidine extends the lifespan of mice and exerts cardioprotective effects, reducing cardiac hypertrophy and preserving diastolic function in old mice. Spermidine feeding enhanced cardiac autophagy, mitophagy and mitochondrial respiration, and it also improved the mechano-elastical properties of cardiomyocytes in vivo, coinciding with increased titin phosphorylation and suppressed subclinical inflammation. Spermidine feeding failed to provide cardioprotection in mice that lack the autophagy-related protein Atg5 in cardiomyocytes. In Dahl salt-sensitive rats that were fed a high-salt diet, a model for hypertension-induced congestive heart failure, spermidine feeding reduced systemic blood pressure, increased titin phosphorylation and prevented cardiac hypertrophy and a decline in diastolic function, thus delaying the progression to heart failure. In humans, high levels of dietary spermidine, as assessed from food questionnaires, correlated with reduced blood pressure and a lower incidence of cardiovascular disease. Our results suggest a new and feasible strategy for protection against cardiovascular disease.
|
|
| 2. |
- Echternach, Matthias, et al.
(author)
-
Laryngeal evidence for the first and second passaggio in professionally trained sopranos
- 2017
-
In: PLOS ONE. - : Public Library Science. - 1932-6203. ; 12:5
-
Journal article (peer-reviewed)abstract
- Introduction Due to a lack of empirical data, the current understanding of the laryngeal mechanics in the passaggio regions (i.e., the fundamental frequency ranges where vocal registration events usually occur) of the female singing voice is still limited. Material and methods In this study the first and second passaggio regions of 10 professionally trained female classical soprano singers were analyzed. The sopranos performed pitch glides from A3 (f(o) = 220 Hz) to A4 (f(o) = 440 Hz) and from A4 (f(o) = 440 Hz) to A5 (f(o) = 880 Hz) on the vowel [i:]. Vocal fold vibration was assessed with trans-nasal high speed videoendoscopy at 20,000 fps, complemented by simultaneous electroglottographic (EGG) and acoustic recordings. Register breaks were perceptually rated by 12 voice experts. Voice stability was documented with the EGG-based sample entropy. Glottal opening and closing patterns during the passaggi were analyzed, supplemented with open quotient data extracted from the glottal area waveform. Results In both the first and the second passaggio, variations of vocal fold vibration patterns were found. Four distinct patterns emerged: smooth transitions with either increasing or decreasing durations of glottal closure, abrupt register transitions, and intermediate loss of vocal fold contact. Audible register transitions (in both the first and second passaggi) generally coincided with higher sample entropy values and higher open quotient variance through the respective passaggi. Conclusions Noteworthy vocal fold oscillatory registration events occur in both the first and the second passaggio even in professional sopranos. The respective transitions are hypothesized to be caused by either (a) a change of laryngeal biomechanical properties; or by (b) vocal tract resonance effects, constituting level 2 source-filter interactions.
|
|
| 3. |
- Fogelberg, Maria, et al.
(author)
-
Underreporting of complete uterine rupture and uterine dehiscence in women with previous cesarean section
- 2017
-
In: Journal of Maternal-Fetal and Neonatal Medicine. - : Informa UK Limited. - 1476-7058 .- 1476-4954. ; 30:17, s. 2058-2061
-
Journal article (peer-reviewed)abstract
- Objective: To determine the true incidence of complete uterine rupture and uterine dehiscence among women delivered by cesarean section after a previous cesarean section. Methods: Medical records of all women who delivered at University Hospital in Malmö, Sweden, during 2005–2009 (n = 21 420) were retrieved from the electronic patient record system (EPRS). After adjustment for inaccuracies, 716 women who had undergone repeat cesarean section were identified and their operation reports were reviewed. Descriptions of complete uterine rupture or uterine dehiscence in operation reports were compared with diagnoses registered in EPRS with International Classification of Diseases codes version 10 (ICD-10). Sensitivity and specificity of complete uterine rupture registration were calculated. Results: There were 13 women with a registered diagnosis of uterine rupture. After reviewing medical records of women with repeat cesarean section, seven additional cases of complete uterine rupture, 33 cases of uterine dehiscence and 39 cases of extremely thin myometrium were identified. The incidence of complete uterine rupture and uterine dehiscence for women who delivered by repeat cesarean section was 2.8% and 10.1%, respectively. Conclusions: Diagnosis of complete uterine rupture was underreported in the EPRS by 35% and diagnosis of uterine dehiscence was missing in 100% of cases.
|
|
| 4. |
- Liljeström, Lena, 1977-
(author)
-
Birth asphyxia : Fetal scalp blood sampling and risk factors for hypoxic ischemic encephalopathy
- 2018
-
Doctoral thesis (other academic/artistic)abstract
- Preventing birth asphyxia is a major challenge in delivery care. The aims of this thesis were to evaluate fetal scalp blood sampling (FBS) and explore risk factors for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE).In a study of 241 deliveries monitored by FBS, a discrepancy between pH and lactate (one abnormal and one normal value) was common (55%) in combined FBS. We found that the frequency of operative deliveries for fetal distress (ODFD) was lower when both pH and lactate were analysed in FBS compared with analysis of only pH or lactate, without affecting neonatal outcome. (Study I)In a questionnaire study, women (n = 51) monitored by FBS generally tolerated the test well. Women without epidural, with higher body mass index (BMI), and with less cervical dilatation had higher pain ratings compared with their counterparts. The obstetricians that performed the test generally experienced the test as easy to perform, but more complicated with high maternal BMI, less cervical dilatation, and higher station of the fetal head. (Study II)In a national cohort of 692 428 live births ≥ 36 weeks, risk factors for moderate to severe HIE were identified. We found a linear association between increasing maternal BMI and decreasing maternal height and risk of HIE. Compared with non-short (≥156 cm) and normal weight (BMI<25 kg/m2) women, short and overweight women had a threefold risk of HIE. (Study III)Obstetric emergencies occurred in 29% of HIE cases, more commonly in parous (37%) than in nulliparous (21%) women. Among nulliparous women, shoulder dystocia was most common, with the strongest association to HIE. In parous women without previous caesarean, shoulder dystocia was most common, but placental abruption had the strongest association to HIE. Among parous women with previous caesarean, uterine rupture was the most prevalent, with the strongest association to HIE. (Study IV)Conclusions: Combined FBS might decrease the frequency of ODFD. FBS is well tolerated in women and generally uncomplicated for the obstetrician to perform. Women with short stature and overweight have increased risk of having an infant with HIE. Obstetric emergencies are common underlying causes of HIE, especially in parous women.
|
|
| 5. |
- Lindegren, Lina, et al.
(author)
-
Improved neonatal outcome after active management of prolonged pregnancies beyond 41+2 weeks in nulliparous, but not among multiparous women
- 2017
-
In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349. ; 96:12, s. 1467-1474
-
Journal article (peer-reviewed)abstract
- Introduction: Prolonged pregnancies are associated with adverse maternal and fetal outcome. In Sweden, no national guidelines exist for when to induce prolonged pregnancies. Material and methods: Singleton cephalic prolonged pregnancies (defined as ≥ 41+3 gestational weeks) during 2001-2013 (n = 199 770) were identified using the Swedish Medical Birth Register. The maternity units were divided into three groups (tertiles) based on the proportion of pregnancies ≥ 42+3 gestational weeks among all pregnancies ≥ 41+3 weeks. The pregnancy outcome among women delivered at the units with the most expectant management of prolonged pregnancies (> 17.6% proceeding to 42+3 weeks), was compared with that among women delivered at units with the most active management (< 12.6% proceeding to 42+3 weeks). Odds ratios (OR) were calculated using simple and multiple logistic regression. Adjustments were made for year of delivery, hospital level, maternal age, body mass index, and smoking. Results: Among primiparas, an increased risk of Apgar score < 7 at 5 minutes [odds ratio (OR) 1.27, 95% CI 1.16-1.41] and meconium aspiration (OR 1.49, 95% CI 1.14-1.95) was found after birth at most expectant units compared with most active units, but among multiparas, no such associations were detected. A decreased rate of cesarean section was found for both primiparas (OR 0.83, 95% CI 0.80-0.86) and multiparas (OR 0.82, 95% CI 0.77-0.86) at units with expectant versus active management. No association between perinatal death and delivery-unit specific management of prolonged pregnancies was detected. Conclusions: Offspring to primiparas might gain from a more active management of prolonged pregnancies, whereas no such improvement of neonatal outcome among multiparous women was detected.
|
|
| 6. |
|
|
| 7. |
- Moraghebi, Roksana, et al.
(author)
-
Term amniotic fluid : An unexploited reserve of mesenchymal stromal cells for reprogramming and potential cell therapy applications
- 2017
-
In: Stem Cell Research and Therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 8:1
-
Journal article (peer-reviewed)abstract
- Background: Mesenchymal stromal cells (MSCs) are currently being evaluated in numerous pre-clinical and clinical cell-based therapy studies. Furthermore, there is an increasing interest in exploring alternative uses of these cells in disease modelling, pharmaceutical screening, and regenerative medicine by applying reprogramming technologies. However, the limited availability of MSCs from various sources restricts their use. Term amniotic fluid has been proposed as an alternative source of MSCs. Previously, only low volumes of term fluid and its cellular constituents have been collected, and current knowledge of the MSCs derived from this fluid is limited. In this study, we collected amniotic fluid at term using a novel collection system and evaluated amniotic fluid MSC content and their characteristics, including their feasibility to undergo cellular reprogramming. Methods: Amniotic fluid was collected at term caesarean section deliveries using a closed catheter-based system. Following fluid processing, amniotic fluid was assessed for cellularity, MSC frequency, in-vitro proliferation, surface phenotype, differentiation, and gene expression characteristics. Cells were also reprogrammed to the pluripotent stem cell state and differentiated towards neural and haematopoietic lineages. Results: The average volume of term amniotic fluid collected was approximately 0.4 litres per donor, containing an average of 7 million viable mononuclear cells per litre, and a CFU-F content of 15 per 100,000 MNCs. Expanded CFU-F cultures showed similar surface phenotype, differentiation potential, and gene expression characteristics to MSCs isolated from traditional sources, and showed extensive expansion potential and rapid doubling times. Given the high proliferation rates of these neonatal source cells, we assessed them in a reprogramming application, where the derived induced pluripotent stem cells showed multigerm layer lineage differentiation potential. Conclusions: The potentially large donor base from caesarean section deliveries, the high yield of term amniotic fluid MSCs obtainable, the properties of the MSCs identified, and the suitability of the cells to be reprogrammed into the pluripotent state demonstrated these cells to be a promising and plentiful resource for further evaluation in bio-banking, cell therapy, disease modelling, and regenerative medicine applications.
|
|
| 8. |
- Muscheler, Raimund, et al.
(author)
-
The Revised Sunspot Record in Comparison to Cosmogenic Radionuclide-Based Solar Activity Reconstructions
- 2016
-
In: Solar Physics. - : Springer Science and Business Media LLC. - 0038-0938 .- 1573-093X. ; 291:9-10, s. 3025-3043
-
Journal article (peer-reviewed)abstract
- Recent revisions in the sunspot records illustrate the challenges related to obtaining a 400-year-long observational record of past solar-activity changes. Cosmogenic radionuclides offer the possibility of obtaining an alternative and completely independent record of solar variability. Here, we illustrate that these records offer great potential for quantitative solar-activity reconstructions far back into the past, and we provide updated radionuclide-based solar-activity reconstructions for the past 2000 years. However, cosmogenic-radionuclide records are also influenced by processes independent of solar activity, leading to the need for critical assessment and correction for the non-solar influences. Independent of these uncertainties, we show a very good agreement between the revised sunspot records and the 10Be records from Antarctica and, in particular, the 14C-based solar-activity reconstructions. This comparison offers the potential of identifying remaining non-solar processes in the radionuclide-based solar-activity reconstructions, but it also helps identifying remaining biases in the recently revised sunspot records.
|
|
| 9. |
- Rebmann, Corinna, et al.
(author)
-
ICOS eddy covariance flux-station site setup : A review
- 2018
-
In: International Agrophysics. - : Walter de Gruyter GmbH. - 0236-8722 .- 2300-8725. ; 32:4, s. 471-494
-
Research review (peer-reviewed)abstract
- The Integrated Carbon Observation System Research Infrastructure aims to provide long-Term, continuous observations of sources and sinks of greenhouse gases such as carbon dioxide, methane, nitrous oxide, and water vapour. At ICOS ecosystem stations, the principal technique for measurements of ecosystem-Atmosphere exchange of GHGs is the eddy-covariance technique. The establishment and setup of an eddy-covariance tower have to be carefully reasoned to ensure high quality flux measurements being representative of the investigated ecosystem and comparable to measurements at other stations. To fulfill the requirements needed for flux determination with the eddy-covariance technique, variations in GHG concentrations have to be measured at high frequency, simultaneously with the wind velocity, in order to fully capture turbulent fluctuations. This requires the use of high-frequency gas analysers and ultrasonic anemometers. In addition, to analyse flux data with respect to environmental conditions but also to enable corrections in the post-processing procedures, it is necessary to measure additional abiotic variables in close vicinity to the flux measurements. Here we describe the standards the ICOS ecosystem station network has adopted for GHG flux measurements with respect to the setup of instrumentation on towers to maximize measurement precision and accuracy while allowing for flexibility in order to observe specific ecosystem features.
|
|
| 10. |
- Söderfjäll, Markus, et al.
(author)
-
Influence on friction from piston ring design, cylinder liner roughness and lubricant properties
- 2017
-
In: Tribology International. - : Elsevier. - 0301-679X .- 1879-2464. ; 116, s. 272-284
-
Journal article (peer-reviewed)abstract
- The piston rings are responsible for a large portion of the fuel consumption in heavy duty diesel engines. In this work a high speed component test rig for evaluation of piston ring friction is used. A number of different piston rings and cylinder liners are evaluated based on their friction performance. Shear thinning of typical multi grade oil is investigated by comparing it to single grade oil. Experimental simulation of higher speeds by decreasing the viscosity is evaluated. A method for indication of effects on oil consumption, without combustion, for different oil control rings is presented. Finally, a numerical simulation model for the oil control ring is validated by comparing the friction predicted with the model to the experimental results
|
|
