Search Results (6)

Objective: The aim of this study was to evaluate patients with hereditary hemorrhagic telangiectasia (HHT) for the potential reperfusion of pulmonary arteriovenous malformations (PAVM) treated by catheter embolization using coils or embolization plugs and to analyze causes of possible reperfusion in order to further improve treatment. Methods: This retrospective study analyzed the data of 345 patients who underwent screening for pulmonary arteriovenous malformations in cases of suspected or confirmed HHT (Osler’s disease). Of these, 118 patients with PAVM that underwent catheter embolization and had at least one follow-up study were included in our study and evaluated for potential reperfusion. Screening and follow-up for the detection of PAVM was performed by dynamic and high-resolution contrast-enhanced magnetic resonance angiography (MRA). The average follow-up time was 6.2 years. Results: Reperfusion was detected in 43 of 118 patients at follow-up. Thirty-five of these patients showed a recanalization of the treated vessel and in eleven patients the formation of collateral vessels resupplying the PAVM were identified as the cause of reperfusion. The average time between embolization and detected reperfusion was 5.6 years. The recanalization of both coils and plugs was observed. The recanalization of coils could be attributed in most cases to an insufficient packing density of the implanted coils. In addition, an enlarged diameter of the feeding artery was confirmed as a risk factor for reperfusion. Conclusions: As the reperfusion of embolized pulmonary arteriovenous malformations can occur after a long time interval post-treatment, regular lifelong follow-up studies after embolization are essential to detect reperfusion at an early stage and avoid serious complications like a brain abscess or stroke through prompt re-embolization. After coil embolization, attention should be paid to sufficiently dense packing to achieve adequate and permanent occlusion. Full article

Long-term space missions require careful resource management and recycling strategies to overcome the limitations of resupply missions. In this study, we investigated the potential to recycle space beverage packaging, which is typically made of low-density polyethylene (LDPE) and PET-aluminum-LDPE (PAL) trilaminate, by developing a LDPE-based composite material with PAL inclusions. Due to the limited availability of space beverage packaging, we replaced it with LDPE powder and commercial coffee packaging for the experiments. Fourier transform infrared spectroscopy (FTIR) was employed to thoroughly analyze the composition of the commercial coffee packaging. The simulant packaging was reduced to a filler, and its thermal properties were characterized by differential scanning calorimetry (DSC), while the particle size was analyzed via scanning electron microscopy (SEM) and the bootstrap resampling technique. Composite specimens were then fabricated by incorporating the filler into the LDPE matrix at loadings of 5 wt% and 10 wt%, and their mechanical and thermal properties were assessed through dynamic mechanical analysis (DMA) and thermal conductivity measurements. The 10 wt% corresponds approximately to the radio between PAL and PE in space beverage packaging and is, therefore, the maximum usable percentage when considering a single package. The results indicate that, as the filler loading increased, the mechanical performance of the composite material decreased, while the thermal conductivity was significantly improved. Finally, 10 wt% LDPE/PAL filaments, with a diameter of 1.7 mm and suitable for the fused filament technique, were produced. Full article

High-affinity nitrate transporters (NRT) are key components for nitrogen (N) acquisition and distribution within plants. However, insights on these transporters in wheat are scarce. This study presents a comprehensive analysis of the NRT2 and NRT3 gene families, where the aim is to shed light on their functionality and to evaluate their responses to N availability. A total of 53 NRT2s and 11 NRT3s were identified in the bread wheat genome, and these were grouped into different clades and homoeologous subgroups. The transcriptional dynamics of the identified NRT2 and NRT3 genes, in response to N starvation and nitrate resupply, were examined by RT-qPCR in the roots and shoots of hydroponically grown wheat plants through a time course experiment. Additionally, the spatial expression patterns of these genes were explored within the plant. The NRT2s of clade 1, TaNRT2.1-2.6, showed a root-specific expression and significant upregulation in response to N starvation, thus emphasizing a role in N acquisition. However, most of the clade 2 NRT2s displayed reduced expression under N-starved conditions. Nitrate resupply after N starvation revealed rapid responsiveness in TaNRT2.1-2.6, while clade 2 genes exhibited gradual induction, primarily in the roots. TaNRT2.18 was highly expressed in above-ground tissues and exhibited distinct nitrate-related response patterns for roots and shoots. The TaNRT3 gene expression closely paralleled the profiles of TaNRT2.1-2.6 in response to nitrate induction. These findings enhance the understanding of NRT2 and NRT3 involvement in nitrogen uptake and utilization, and they could have practical implications for improving nitrogen use efficiency. The study also recommends a standardized nomenclature for wheat NRT2 genes, thereby addressing prior naming inconsistencies. Full article

A better understanding of the P dynamic resupply roles of fertilization from soil solids to solution is urgently required to optimize sustainable P fertilizer management practices for efficient supply. A five–year fertilization experiment was used to investigate the effects on soil P fractions and availability, the kinetic P resupply based on a novel simulation technique (Diffusive gradients in thin films (DGT) and DGT–induced fluxes in sediments and soils (DIFS) ) and to identify dominant factors during the maize season under five treatments (no fertilizer (CK), chemical fertilizer (NPK), chemical fertilizer combined with bone meal fertilizer (NPKC), crop straw (NPKS) and bioorganic fertilizer (NPKM)). The results showed that the NPKC and NPKM treatments had higher enhancement effects on Olsen–P and organic P and inorganic Ca₂–P, Ca₈–P, Al–P and Fe–P at maize growth stages, and they buffered pH decrease to delay the substantial Fe–P and Al–P release until a late stage. Inorganic Ca₂–P, Ca₈–P, Al–P and Fe–P heavily effected the Olsen–P levels. The NPKS, NPKC and NPKM treatments yielded higher C_DGT–P levels and a stronger resupply capacity, reflected by higher R and C_E/C_soln and smaller T_c values. The simulation and path model results revealed that the maize plant P uptake was determined by soil P resupply and an inorganic P supply pool. They were positively dominated by soil organic matter (SOM). Our results suggested that organic fertilization, especially NPKC and NPKM treatments, provided greater enhancement effects on the P supply pool and P resupply for higher plant P uptake, identifying them as highly effective P management practices for developing sustainable agriculture. Full article

The seasonal dynamic changes of Tibetan glaciers have seen little prior investigation, despite the increase in geodetic studies of multi-year changes. This study compares seasonal glacier dynamics (“cold” and “warm” seasons) in the ablation zone of Parlung No. 4 Glacier, a temperate glacier in the monsoon-influenced southeastern Tibetan Plateau, by using repeat unpiloted aerial vehicle (UAV) surveys combined with Structure-from-Motion (SfM) photogrammetry and ground stake measurements. Our results showed that the surveyed ablation zone had a mean change of −2.7 m of ice surface elevation during the period of September 2018 to October 2019 but is characterized by significant seasonal cyclic variations with ice surface elevation lifting (+2.0 m) in the cold season (September 2018 to June 2019) but lowering (−4.7 m) in the warm season (June 2019 to October 2019). Over an annual timescale, surface lowering was greatly suppressed by the resupply of ice from the glacier’s accumulation area—the annual emergence velocity compensates for about 55% of surface ablation in our study area. Cold season emergence velocities (3.0 ± 1.2 m) were ~5-times larger than those observed in the warm season (0.6 ± 1.0 m). Distinct spring precipitation patterns may contribute to these distinct seasonal signals. Such seasonal dynamic conditions are possibly critical for different glacier responses to climate change in this region of the Tibetan Plateau, and perhaps further afield. Full article

In this study, we analyzed the night-time light dynamics in Iraq over the period 2012–2017 by using Visible Infrared Imaging Radiometer Suite (VIIRS) monthly composites. The data quality of VIIRS images was improved by repairing the missing data, and the Night-time Light Ratio Indices (NLRIs), derived from urban extent map and night-time light images, were calculated for different provinces and cities. We found that when the Islamic State of Iraq and Syria (ISIS) attacked or occupied a region, the region lost its light rapidly, with the provinces of Al-Anbar, At-Ta’min, Ninawa, and Sala Ad-din losing 63%, 73%, 88%, and 56%, of their night-time light, respectively, between December 2013 and December 2014. Moreover, the light returned after the Iraqi Security Forces (ISF) recaptured the region. In addition, we also found that the night-time light in the Kurdish Autonomous Region showed a steady decline after 2014, with the Arbil, Dihok, and As-Sulaymaniyah provinces losing 47%, 18%, and 31% of their night-time light between December 2013 and December 2016 as a result of the economic crisis in the region. The night-time light in Southern Iraq, the region controlled by Iraqi central government, has grown continuously; for example, the night-time light in Al Basrah increased by 75% between December 2013 and December 2017. Regions formerly controlled by ISIS experienced a return of night-time light during 2017 as the ISF retook almost all this territory in 2017. This indicates that as reconstruction began, electricity was re-supplied in these regions. Our analysis shows the night-time light in Iraq is directly linked to the socioeconomic dynamics of Iraq, and demonstrates that the VIIRS monthly night-time light images are an effective data source for tracking humanitarian disasters in that country. Full article