| 1. |
- Angelini, Giulia, et al.
(author)
-
Small intestinal metabolism is central to whole-body insulin resistance
- 2021
-
In: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 70:6, s. 1098-1109
-
Journal article (peer-reviewed)abstract
- Objective To assess the role of jejunum in insulin resistance in humans and in experimental animals. Design Twenty-four subjects undergoing biliopancreatic diversion (BPD) or Roux-en-Y gastric bypass (RYGB) were enrolled. Insulin sensitivity was measured at baseline and at 1week after surgery using oral glucose minimal model. We excluded the jejunum from intestinal continuity in pigs and created a jejunal loop with its vascular and nerve supply intact accessible from two cutaneous stomas, and reconnected the bowel with an end-to-end anastomosis. Glucose stable isotopes were given in the stomach or in the jejunal loop. In vitro studies using primary porcine and human hepatocytes or myoblasts tested the effects of plasma on gluconeogenesis or glucose uptake and insulin signalling. Results Whole-body insulin sensitivity (SI∙104: 0.54±0.12 before vs 0.82±0.11 after BPD, p=0.024and 0.41±0.09 before vs 0.65±0.09/pM/min after RYGB, p=not significant) and Glucose Disposition Index increased only after BPD. In pigs, insulin sensitivity was significantly lower when glucose was administered in the jejunal loop than in the stomach (glucose rate of disappearance (Rd) area under the curve (AUC)/insulin AUC∙10: 1.82±0.31 vs 2.96±0.33mmol/pM/min, p=0.0017). Metabolomics showed a similar pattern before surgery and during jejunal-loop stimulation, pointing to a higher expression of gluconeogenetic substrates, a metabolic signature of impaired insulin sensitivity. A greater hepatocyte phosphoenolpyruvate-carboxykinase and glucose-6-phosphatase gene expression was elicited with plasma from porcine jejunal loop or before surgery compared with plasma from jejunectomy in pigs or jejunal bypass in humans. Stimulation of myoblasts with plasma from porcine jejunal loop or before surgery reduced glucose uptake, Ser473-Akt phosphorylation and GLUT4 expression compared with plasma obtained during gastric glucose administration after jejunectomy in pigs or after jejunal bypass in humans. Conclusion Proximal gut plays a crucial role in controlling insulin sensitivity through a distinctive metabolic signature involving hepatic gluconeogenesis and muscle insulin resistance. Bypassing the jejunum is beneficial in terms of insulin-mediated glucose disposal in obesity.
|
|
| 2. |
- Fridner, Ann, et al.
(author)
-
Work Environment and Recent Suicidal Thoughts Among Male University Hospital Physicians in Sweden and Italy : The Health and Organization Among University Hospital Physicians in Europe (HOUPE) Study
- 2011
-
In: Gender Medicine. - : Elsevier BV. - 1550-8579 .- 1878-7398. ; 8:4, s. 269-279
-
Journal article (peer-reviewed)abstract
- Background: Male and female physicians are at elevated suicide risk. The work environment has become a focus of attention as a possible contributor to this risk. The potential association between work environment and suicidal thoughts has been examined among female physicians in several countries, and significant findings have been reported. Objective: The purpose of this study was to examine the role of the work environment in relation to suicidal thoughts among male university hospital physicians in 2 European countries. Methods: Cross-sectional multivariate analysis was performed to identify significant associations between work-related factors and suicide risk among male physicians from the Health and Organization among University Hospital Physicians in Europe (HOUPE) study. The dependent variable was termed recent suicidal thoughts, which includes having thought about suicide and/or having thought about specific ways to commit suicide within the previous year. Adjusted odds ratios (ORs) and CIs are reported. Results: Of the 456 Swedish (56%) and 241 Italian (39%) male physicians who participated, 12% of the physicians from each country reported affirmatively regarding recent suicidal thoughts. Degrading work experiences were associated with recent suicidal thoughts for the Swedish and Italian physicians (OR = 2.1; 95% CI, 1.01–4.5; OR = 3.3; 95% CI, 1.3–8.0, respectively). Role conflict was associated with recent suicidal thoughts among the Swedish physicians (OR = 1.6; 95% CI, 1.1–2.2). Support at work when difficulties arose appeared to be protective for the Swedish physicians (OR = 0.7; 95% CI, 0.5–0.96). Italian physicians with little control over working conditions had an increased risk of recent suicidal thoughts, whereas confidential discussions about work experiences appeared to be protective (OR = 0.6; 95% CI, 0.4–0.9). Conclusion: Attention should be paid to the work environment as it relates to suicide risk among male university hospital physicians, particularly to bolstering social support and preventing harassment.
|
|
| 3. |
- Khaustov, Vladislav O., et al.
(author)
-
Heterocontact-Triggered 1H to 1T′ Phase Transition in CVD-Grown Monolayer MoTe2 : Implications for Low Contact Resistance Electronic Devices
-
In: ACS Applied Nano Materials. - 2574-0970.
-
Journal article (peer-reviewed)abstract
- Single-layer molybdenum ditelluride (MoTe2) has attracted attention due to the smaller energy difference between the semiconducting (1H) and semimetallic (1T′) phases with respect to other two-dimensional transition metal dichalcogenides (TMDs). Understanding the phenomenon of polymorphism between these structural phases is of great fundamental and practical importance. In this paper, we report a 1H to 1T′ phase transition occurring during the chemical vapor deposition (CVD) synthesis of single-layer MoTe2 at 730 °C. The transformation originates at the heterocontact between monoclinic and hexagonal crystals and progresses to either yield a partial or complete 1H to 1T′ phase transition. Microscopic and spectroscopic analyses of the MoTe2 crystals reveal the presence of Te vacancies and mirror twin boundaries (MTB) domains in the hexagonal phase. The experimental observations and theoretical simulations indicate that the combination of heterocontact formation and Te vacancies are relevant triggering mechanisms in the observed transformation. By advancing in the understanding and controlling of the direct synthesis of lateral 1T′/1H heterostructures, this work contributes to the development of MoTe2-based electronic and optoelectronic devices with low contact resistance.
|
|
| 4. |
- Mancina, Rosellina Margherita, et al.
(author)
-
PSD3 downregulation confers protection against fatty liver disease.
- 2022
-
In: Nature metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 4:1, s. 60-75
-
Journal article (peer-reviewed)abstract
- Fatty liver disease (FLD) is a growing health issue with burdening unmet clinical needs. FLD has a genetic component but, despite the common variants already identified, there is still a missing heritability component. Using a candidate gene approach, we identify a locus (rs71519934) at the Pleckstrin and Sec7 domain-containing 3 (PSD3) gene resulting in a leucine to threonine substitution at position 186 of the protein (L186T) that reduces susceptibility to the entire spectrum of FLD in individuals at risk. PSD3 downregulation by short interfering RNA reduces intracellular lipid content in primary human hepatocytes cultured in two and three dimensions, and in human and rodent hepatoma cells. Consistent with this, Psd3 downregulation by antisense oligonucleotides in vivo protects against FLD in mice fed a non-alcoholic steatohepatitis-inducing diet. Thus, translating these results to humans, PSD3 downregulation might be a future therapeutic option for treating FLD.
|
|
| 5. |
- Marini, Lorenzo, et al.
(author)
-
Crop management modifies the benefits of insect pollination in oilseed rape
- 2015
-
In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 207, s. 61-66
-
Journal article (peer-reviewed)abstract
- In a factorial field plot experiment, high and low levels of inorganic nitrogen and of insect pollinators visiting the crop were manipulated and their combined effects on oilseed rape yield were quantified. A third factor was also included, testing whether different cultivars responded differently to the tested factors. Insect pollination was required to reach high yield and seed quality (oil content). Final benefits of pollination service were, however, greatly modified by cultivar, where the seed yield of the open-pollinated cultivar largely depended on insect pollination whereas the two hybrid cultivars did not. A near significant interaction between nitrogen input and insect pollination was also found, i.e. benefits to crop yield from insect pollination seemed to increase with decreased nitrogen levels. The differential response of the three cultivars suggested opportunities to use cultivars that are less dependent on insect pollination in landscapes where this service has been deteriorated. Increased access of nitrogen seems to partly compensate yield losses from poor insect pollination. Integrating conservation, environmental and agronomic sciences is therefore crucial to sustain agriculture productions through optimized management of agronomic inputs and biodiversity-based ecosystem services. (C) 2015 Elsevier B.V. All rights reserved.
|
|
| 6. |
- Salvi, Paolo, et al.
(author)
-
Hydrogen evolution reaction in PTFE bonded Raney-Ni electrodes
- 2011
-
In: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 36:13, s. 7816-7821
-
Journal article (peer-reviewed)abstract
- This study is concerned with the hydrogen evolution reaction (HER) in several PTFE bonded Raney-Ni electrodes as function of temperature and treatments. The Mo-doped Raney-Ni catalysts are activated by hours of long cathodic polarization interleaved with few deep "charge - discharge" (polarity reversal) cycles. Moreover, the HER efficiency of the electrode requires additives which enhance conductivity and surface properties: with powders of Ni alloys (Ni-Ti, Ni-Cr, Ni-Fe) the electrode becomes also more stable, and almost insensitive to polarity reversal. The main effect of a temperature increase is the reduction of the Tafel slope, which is about 120 mV/dec at 25 degrees C, and about 60 mV/dec at 60 degrees C. A proper choice of additives yield electrodes which withstand polarity reversal and may be used in electrolysers which are intermittently operated, or have anodes which require periodic in situ re-activation by reduction.
|
|
| 7. |
- Tamburini, Giovanni, et al.
(author)
-
Drought and soil fertility modify fertilization effects on aphid performance in wheat
- 2018
-
In: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 30, s. 23-31
-
Journal article (peer-reviewed)abstract
- Agricultural intensification and climate change are expected to affect pest performance through excessive inputs of chemical fertilizers and increased probability of extreme drought events. Potential interactive effects of fertilization and water availability on aboveground pest performance may depend on soil fertility because of its effect on nutrient availability. In a greenhouse experiment, we examined the effects of inorganic fertilization on the performance of the grain aphid (Sitobion avenae, E), an important pest of wheat, under different conditions of soil fertility and water availability. We found soil fertility and water availability to influence the positive effects of inorganic fertilizers on aphid growth, i.e. fertilization promoted faster aphid development time and higher fecundity and biomass under low fertility and under well-watered conditions. Moreover, although increased soil fertility favored aphid growth under well-watered conditions, it simultaneously sustained plant development. The current practices promoting soil fertility do not have direct negative consequence on crop protection under conventional cropping systems. (C) 2018 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.
|
|
| 8. |
- Tamburini, Giovanni, et al.
(author)
-
Landscape composition predicts the distribution of Philaenus spumarius, vector of Xylella fastidiosa, in olive groves
- 2019
-
In: Journal of Pest Science. - : Springer Science and Business Media LLC. - 1612-4758 .- 1612-4766. ; 92, s. 1101-1109
-
Journal article (peer-reviewed)abstract
- The meadow spittlebug, Philaenus spumarius (Hemiptera: Aphrophoridae; Linnaeus, 1758), is considered the main vector in the ongoing Xylella fastidiosa outbreak in the olive groves of southern Italy. Identifying the factors driving the spatial distribution of P. spumarius is of primary importance to determine X. fastidiosa infection risk in healthy olive groves. Here, we investigated the local and landscape factors shaping the occurrence and abundance of P. spumarius by sampling 182 olive groves over 2years in the Abruzzo region. We found the occurrence and abundance of the vector to be positively associated with the proportion of olive groves in the landscape and negatively with the cover of vineyards. Philaenus spumarius best responded to landscape processes at small spatial scale (125-250m) confirming the available information regarding its dispersal ability. At the local scale, soil management and pesticide application did not affect the vector probably because both interventions were not timed according to the vector biology and ecology. Our findings suggest that the management of agricultural landscape mosaics can drive the spatial distribution of P. spumarius. In particular, the landscape composition of the close surrounding of the olive groves may potentially influence the emergence probability of local X. fastidiosa epidemics through its effects on the vector spatial distribution and activity.
|
|
| 9. |
- Tamburini, Giovanni, et al.
(author)
-
Pollination benefits are maximized at intermediate nutrient levels
- 2017
-
In: Proceedings of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 284
-
Journal article (peer-reviewed)abstract
- Yield production in flowering crops depends on both nutrient availability and pollination, but their relative roles and potential interactions are poorly understood. We measured pollination benefits to yield in sunflower, combining a gradient in insect pollination (0, 25, 50, 100%) with a continuous gradient in nitrogen (N) fertilization (from 0 to 150 kg N ha(-1)) in an experiment under realistic soil field conditions. We found that pollination benefits to yield were maximized at intermediate levels of N availability, bolstering yield by approximately 25% compared with complete pollinator exclusion. Interestingly, we found little decrease in yield when insect visits were reduced by 50%, indicating that the incremental contribution of pollination by insects to yield is greater when the baseline pollination service provision is very low. Our findings provide strong evidence for interactive, nonlinear effects of pollination and resource availability on seed production. Our results support ecological intensification as a promising strategy for sustainable management of agroecosystems. In particular, we found optimal level of pollination to potentially compensate for lower N applications.
|
|
