•Increasing the volumetric-energy-density during DMLS reduces the surface roughness.•Decreasing the hatch-distance forms a periodic large and small melt pools pattern.•The larger melt pools revealed ...coarser microstructural features.•The larger melt pools control the overall corrosion resistance of the part.•Faster solidification rate along melt pool borders improves the corrosion behavior.
In this study, in-depth microstructure and electrochemical properties of highly smoothed AlSi10Mg parts fabricated through direct-metal-laser-sintering are reported. The samples with the lowest surface roughness were characterized by having a periodic large and small melt pools (MPs) pattern in their upskin layers. Consequently, a noticeably coarser eutectic-Si network, Al-dendrite and grain size formed along the larger MPs’ borders, rationalized by their slower solidification rate. Such microstructural features were found to control/deteriorate the electrochemical performance of the as-printed samples than their surface roughness. An improved electrochemical stability for the samples that experience the fastest solidification rate along their MP-boundaries was revealed.
Enterotoxigenic Bacteroides fragilis (ETBF), a human commensal and candidate pathogen in colorectal cancer (CRC), is a potent initiator of interleukin-17 (IL-17)-dependent colon tumorigenesis in Min
...mice. We examined the role of IL-17 and ETBF on the differentiation of myeloid cells into myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages, which are known to promote tumorigenesis. The myeloid compartment associated with ETBF-induced colon tumorigenesis in Min mice was defined using flow cytometry and gene expression profiling. Cell-sorted immature myeloid cells were functionally assayed for inhibition of T-cell proliferation and inducible nitric oxide synthase expression to delineate MDSC populations. A comparison of ETBF infection with that of other oncogenic bacteria (Fusobacterium nucleatum or pks
Escherichia coli) revealed a specific, ETBF-associated colonic immune infiltrate. ETBF-triggered colon tumorigenesis is associated with an IL-17-driven myeloid signature characterized by subversion of steady-state myelopoiesis in favor of the generation of protumoral monocytic-MDSCs (MO-MDSCs). Combined action of the B. fragilis enterotoxin BFT and IL-17 on colonic epithelial cells promoted the differentiation of MO-MDSCs, which selectively upregulated Arg1 and Nos2, produced NO, and suppressed T-cell proliferation. Evidence of a pathogenic inflammatory signature in humans colonized with ETBF may allow for the identification of populations at risk for developing colon cancer.
In this study, the impact of surface finishing procedures on the corrosion resistance of an AlSi10Mg_200C alloy manufactured through direct metal laser sintering (DMLS) versus its die cast ...counterpart was investigated. The as-printed DMLS-AlSi10Mg_200C and as-cast A360.1 alloys were subjected to various surface finishing processes including grinding and sandblasting. The corrosion performance of the surfaces was then evaluated using a potentiodynamic polarization test and electrochemical impedance spectroscopy in an aerated 3.5 wt.% NaCl solution. The results highlighted the better corrosion resistance of DMLS-AlSi10Mg_200C than its cast counterpart with a similar surface finish. The grinding of both as-printed DMLS and as-cast samples was found to initially deteriorate the corrosion performance of the surface by exposing cathodic sites to the electrolyte. However, for longer immersion times and after complete repassivation of the surface, the ground surface showed the highest resistance to the selective attack. The sandblasting process was found to have a detrimental effect on the corrosion resistance of both alloys.
The hydrogen effect on a X65 carbon steel was investigated by tensile tests under both ex-situ and in-situ hydrogen charging conditions. The fractured samples were characterized and compared using a ...combination of scanning electron microscopy, electron backscattering diffraction, and energy-dispersive spectroscopy. The work highlights that the in-situ hydrogen charging is a necessity for investigation of hydrogen detrimental effects on the studied material, where a pronounced reduction in fracture elongation, the evolution of secondary cracks on gauge surface, and the corresponding brittle fractography were thoroughly characterized after in-situ testing. The reason resides in the rapid hydrogen outgassing effect, which was proved by Fick's law-based diffusion models. Then the interrupted tensile tests were performed to track the crack initiation and propagation behavior. The results show that the majority of cracks initiated at the interfaces of MnS and Al2O3 inclusions or between inclusions and matrix, which attributes to the elevated stress concentration around the inclusions. Moreover, the cracks were found to propagate along the {110} slip planes.
•Ex-situ and in-situ H charging method was compared on a X65 carbon steel.•In-situ H charging is more suitable for investigation of hydrogen embrittlement.•H-induced cracks initiate at non-metallic inclusions due to stress concentration.•H-induced cracks propagate in transgranular manner along the {110} planes.
It is now widely accepted that dietary phytochemicals inhibit cancer progression and enhance the effects of conventional chemotherapy. In this report, we comparatively studied the cellular and ...molecular aspects of apoptosis induction by the methanolic extract of
Baneh
fruit skin in comparison to Doxorubicin (Dox), a well-known anticancer drug, in human breast cancer T47D cells
.
The MTT assay was used to determine the antiproliferative effects. The flow cytometric and microscopic analyses were done to evaluate the apoptosis induction. Furthermore, western blot analyses have been done to study the role of key molecular players of apoptosis including caspase 3 and PARP. The
Baneh
extract showed strong antiproliferative activity against T47D cells in a dose- and time-dependent manner that was comparable to and even stronger than Dox in certain concentrations. Analysis of
Baneh
-treated cells by flow cytometry and fluorescence microscopy indicated strong apoptosis induction and nuclear morphological alterations similar to or greater than Dox. Finally, molecular analysis of apoptosis by western blotting proved activation of caspase 3 followed by poly ADP ribose polymerase (PARP) cleavage more efficiently in
Baneh
than in Dox treated cancer cells. These findings indicate that
Baneh
extract contains phytochemicals which act as inhibitor of cell proliferation and inducer of apoptosis in human breast cancer T47D cells that makes it a potentially good candidate for new anticancer drug development.
The study of community structure changes in relation to environmental gradients can help assessing and predicting community response to anthropogenic disturbances; however, such types of studies are ...rare in semi-arid regions. This study aimed at investigating the macroinvertebrate community composition in response to environmental variables in rivers of a semi-arid mountainous region, i.e., the Zagros mountain range, southwestern Iran. Environmental variables and macroinvertebrates were sampled at 54 sites in four seasons during 2018–2019. A total of 101 families of benthic macroinvertebrates from 8 classes and 21 orders were identified. Diversity and evenness indices showed significant temporal variation (
p
< 0.05). Also, taxa richness and Ephemeroptera, Plecoptera, and Trichoptera taxa showed strong seasonal stability, whereas spatial variation among all metrics was significantly different (
p
< 0.05). Taxa richness and density weekly correlated with altitudinal gradient. Correlation analysis, cluster analysis, non-metric multidimensional scaling, and canonical correspondence analysis demonstrated associations between community composition and environment variables, including definition of site groupings according to aggregated quality estimates. The results suggest that both physico-chemical variables of water (nitrate, total dissolved solids,
Escherichia coli
, temperature, chemical oxygen demand, and dissolved oxygen) and habitat structure (wetted river width, altitude, and riffles presence) determined the community composition of macroinvertebrates. Seasonal variation of community indices and community composition in our region seemed to differ from those estimated from subarctic, temperate and subtropical ecosystems. Our study provides a strong basis for further research, planning, and conservation of macroinvertebrate communities in the Karun River basin and similar river systems in the region.
IntroductionWheat is globally one of the most critical cereals. It is necessary to increase its yield to cope with the increasing population through management improvement or breeding due to ...decreased arable lands. Soil moisture before planting and rainfall during the growing season are the two primary water supply sources for rainfed wheat production. However, the non-uniform distribution of rainfall during the growing season leads to drought, affecting crop water consumption and natural wheat growth. Irrigation is the primary way to meet the plant's water requirement for growth, development, and high yield. Since water availability is limited in Iran and on the other hand, different cultivars have different sensitivities to drought stress at various stages of growth, so reducing different degrees of water consumption may have unequal effects on crop yield. This type of management, known as deficit-irrigation, often increases water use efficiency. Drip irrigation provides optimized use of water and nutrients during the growing season. In addition to water consumption, the balanced application of fertilizers is an influential factor in increasing agricultural production, and nitrogen is the most critical fertilizer recommended to improve wheat yield. Nitrogen can increase wheat yield by increasing the number of spikes per square meter, the number of grains per spike, and 1000-grain weight. This study aims to determine the optimum water consumption and nitrogen fertilizer under the drip irrigation system according to wheat physiological traits.Materials and MethodsThis experiment was performed as split plot based on a randomized complete block design with three replications in the Research Farm of the University of Kurdistan located in the Dehgolan plain in 2018-19 cropping year. Factors were in various irrigation levels (60, 80, 100, and 120% of crop water requirement) as the main plots and nitrogen fertilizer treatments (fertilizer application of 50, 75, 100, and 125% of plant nitrogen requirement based on soil test) as subplots. Sampling was done in all three replications to calculate soil weight moisture and determine the irrigation water requirement in each irrigation stage. The soil moisture balance method was used to determine the crop's water requirement according to the volume percentage of moisture in the control plot (treatment of providing 100% water requirement). Based on the soil test results, the optimal nitrogen application in the control treatment was considered equivalent to 200 kg.ha-1 of urea. Other experimental treatments were calculated based on the control treatment. In this experiment, traits such as biological yield, grain yield, harvest index, water use efficiency (WUE), chlorophyll content (chlorophyll a, chlorophyll b, and total chlorophyll), remobilization, grain protein content, protein percent, and agronomic nitrogen use efficiency (ANUE) were evaluated. Data were analyzed using SAS statistical software, and the means were compared using Duncan's multiple range test at 5% probability.Results and DiscussionThe results showed that the effects of different irrigation and nitrogen levels were significant on biological yield, grain yield (P <0.01), and grain protein percent (p≤0.05). The interaction effect of irrigation and nitrogen was significant on WUE (p≤0.05), chlorophyll content, remobilization, and ANUE (P <0.01). In comparing different irrigation levels, The highest and lowest biological yields were obtained in the treatments of 120% water requirement (15976 kg.ha-1) and 60% water requirement (12975 kg.ha-1), respectively. Among different nitrogen treatments, the highest and lowest biological yields were observed in 125% fertilizer requirement (15141 kg.ha-1) and 50% fertilizer requirement (12640 kg.ha-1), respectively. The highest and lowest yields were observed in the treatments of supply of 120% (6498 kg.ha-1) and 60% (4933 kg.ha-1) of water requirement, respectively. The rate of yield increase in 120% water requirement treatment was 9, 18, and 24%, compared to 100, 80, and 60% of water requirement treatments, respectively. However, the highest WUE was obtained in 60% crop water requirement treatment and providing 100% of nitrogen consumption (3.08 kg.m-3). In water deficit conditions, providing 100% of the plant's nitrogen requirement keeps WUE in high level. If the amount of nitrogen is reduced, WUE was also decreased. The highest and lowest ANUE were observed in 100% water requirement treatment fertilized with 75% of nitrogen requirement (79 kg.kg-1) and 120% water requirement treatment fertilized with 100% nitrogen requirement (9 kg.kg-1), respectively. With decreasing water consumption, the rate of stem remobilization increased to the highest level, which was observed in the treatment of 60% of water requirement fertilized with 100% nitrogen requirement. The highest chlorophyll concentration was related to the 100% crop water requirement treatment fertilized with 100% of nitrogen requirementirement.
In this study we report theoretical and experimental evidence for the formation of ionic products by the ion-neutral reaction of C2H2N+ with C2H6. Our investigations consist of laboratory ...measurements using a guided ion beam mass spectrometer together with complementary ab initio quantum chemical computations, at the MP2/6-311++G(d,p) level of theory, in order to elucidate the energetics and geometries of the intermediates and transition states that are involved in the production of the observed product ions. This study also provides insights on the isomeric nature of the observed product ions, their formation pathways together with collision energy and pressure dependences. The experimental data agrees well with the predictions of the ab initio calculations. Despite data provides evidence for the occurrence of C2H5+ as the most salient product ion, the production of CH3+, C2H3+, C3H5+, C3H7+ and C2H4N+ is also evident. A reaction scheme was proposed to elucidate the mechanisms responsible for the formation of the observed product ions. These processes might be intermediate steps in the generation of long chain carbon and nitrogen-bearing compounds in Titan's ionosphere, the interstellar medium or circumstellar envelopes.
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