Novel approaches to produce Al2O3–TiC/TiCN–Fe composite powders directly from ilmenite

AbstractAl2O3–TiC/TiCN–Fe composite powders were successfully prepared directly from ilmenite at 1300–1400°C. The effects of Al/C ratio, sintering atmosphere, and reaction temperature and time on the reaction products were investigated. Results showed that the nitrogen atmosphere was beneficial to the reduction of ilmenite and the formation of Al2O3–TiC/TiCN–Fe composite powders. When the reaction temperature was between 600 and 1100°C, the intermediate products, TiO2, Ti3O5 and Ti4O7 were found, which changed to TiC or TiCN at higher temperature. Al/C ratio was found to affect the reaction process and synthesis products. When Al addition was 0.5mol, the Al2O3 phase did not appear. The content of carbon in TiCN rose when the reaction temperature was increased

Identification of a Dominant Gene in Medicago truncatula That Restricts Nodulation by Sinorhizobium meliloti Strain Rm41

BACKGROUND: Leguminous plants are able to form a root nodule symbiosis with nitrogen-fixing soil bacteria called rhizobia. This symbiotic association shows a high level of specificity. Beyond the specificity for the legume family, individual legume species/genotypes can only interact with certain restricted group of bacterial species or strains. Specificity in this system is regulated by complex signal exchange between the two symbiotic partners and thus multiple genetic mechanisms could be involved in the recognition process. Knowledge of the molecular mechanisms controlling symbiotic specificity could enable genetic improvement of legume nitrogen fixation, and may also reveal the possible mechanisms that restrict root nodule symbiosis in non-legumes. RESULTS: We screened a core collection of Medicago truncatula genotypes with several strains of Sinorhizobium meliloti and identified a naturally occurring dominant gene that restricts nodulation by S. meliloti Rm41. We named this gene as Mt-NS1 (for M.truncatulanodulation specificity 1). We have mapped the Mt-NS1 locus within a small genomic region on M. truncatula chromosome 8. The data reported here will facilitate positional cloning of the Mt-NS1 gene. CONCLUSIONS: Evolution of symbiosis specificity involves both rhizobial and host genes. From the bacterial side, specificity determinants include Nod factors, surface polysaccharides, and secreted proteins. However, we know relatively less from the host side. We recently demonstrated that a component of this specificity in soybeans is defined by plant NBS-LRR resistance (R) genes that recognize effector proteins delivered by the type III secretion system (T3SS) of the rhizobial symbionts. However, the lack of a T3SS in many sequenced S. meliloti strains raises the question of how the specificity is regulated in the Medicago-Sinorhizobium system beyond Nod-factor perception. Thus, cloning and characterization of Mt-NS1 will add a new dimension to our knowledge about the genetic control of nodulation specificity in the legume-rhizobial symbiosis

Routing Protocols for Underwater Acoustic Sensor Networks: A Survey from an Application Perspective

Underwater acoustic communications are different from terrestrial radio communications; acoustic channel is asymmetric and has large and variable end‐to‐end propagation delays, distance‐dependent limited bandwidth, high bit error rates, and multi‐path fading. Besides, nodes’ mobility and limited battery power also cause problems for networking protocol design. Among them, routing in underwater acoustic networks is a challenging task, and many protocols have been proposed. In this chapter, we first classify the routing protocols according to application scenarios, which are classified according to the number of sinks that an underwater acoustic sensor network (UASN) may use, namely single‐sink, multi‐sink, and no‐sink. We review some typical routing strategies proposed for these application scenarios, such as cross‐layer and reinforcement learning as well as opportunistic routing. Finally, some remaining key issues are highlighted

On the microstructure and mechanical property of as-extruded Mg-Gd-Y-Zn alloy with Sr addition

In this study, microstructure evolutions of Mg-6Gd-3Y-0.1Zn-xSr (x=0, 0.2, 0.6) alloys (named as sample 0Sr, 0.2Sr, 0.6Sr) during heat-treatment and extrusion were investigated. As-cast sample 0Sr contains typical long period stacking ordered (LPSO) phases and MgRE. With Sr addition, amounts of LPSO phases decrease and are gradually replaced by the MgSr phases. After homogenization and annealing treatment, profuse strip LPSO phases readily precipitate in grain interiors of sample 0Sr, while only MgSr and MgRE phases are detected in samples 0.2Sr and 0.6Sr. It suggests that the Sr addition would inhibit LPSO phases. After extrusion, the bimodal grain structures, the bulk and strip LPSO phases are detected in sample 0Sr, which can contribute to providing strengthening and extra strain hardening. In as-extruded sample 0.2Sr, finer recrystallized grain size, bulk MgSr and LPSO phases (micron-scale) and MgRE phase (nano-scale) are found due to the pre-annealing treatment. However, lower amounts of both nano-sized and macro-sized LPSO phases lead to the low ultimate strength (300 MPa). In sample 0.6Sr, the strip LPSO phases are readily formed even though the length and total amounts of LPSO phases decrease. More bulk MgSr phases and LPSO phases are also precipitated, which lead to the more superior yield and ultimate strengths of 0.6Sr sample under higher temperature, as compared with the 0Sr sample

Discovery of N-arylsulfonyl-3-acylindole benzoyl hydrazone derivatives as anti-HIV-1 agents

The discovery and development of novel inhibitors with activity against variants of human immunodeficiency virus type 1 (HIV-1) is pivotal for overcoming treatment failure. As our ongoing work on research of anti-HIV-1 inhibitors, 32 N-arylsulfonyl-3-acylindole benzoyl hydrazone derivatives were prepared by introduction of the hydrazone fragments on the N-arylsulfonyl-3-acylindolyl skeleton and preliminarily screened in vitro as HIV-1 inhibitors for the first time. Among of all the reported analogues, eight compounds exhibited significant anti-HIV-1 activity, especially N-(3-nitro)phenylsulfonyl-3- acetylindole benzoyl hydrazone (18) and N-(3-nitro)phenylsulfonyl-3-acetyl-6-methylindole benzoyl hydrazone (23) displayed the most potent anti-HIV-1 activity with EC50 values of 0.26 and 0.31 μg/mL, and TI values of >769.23 and >645.16, respectively. It is noteworthy that introduction of R3 as the methyl group and R2 as the hydrogen group could result in more potent compounds. This suggested that introduction of R3 as the methyl group could be taken into account for further preparation of these kinds of compounds as anti-HIV-1 agents

The Soybean \u3cem\u3eRfg1\u3c/em\u3e Gene Restricts Nodulation by \u3cem\u3eSinorhizobium fredii\u3c/em\u3e USDA193

Sinorhizobium fredii is a fast-growing rhizobial species that can establish a nitrogen-fixing symbiosis with a wide range of legume species including soybeans (Glycine max). In soybeans, this interaction shows a high level of specificity such that particular S. fredii strains nodulate only a limited set of plant genotypes. Here we report the identification of a dominant gene in soybeans that restricts nodulation with S. fredii USDA193. Genetic mapping in an F2 population revealed co-segregation of the underlying locus with the previously cloned Rfg1 gene. The Rfg1 allele encodes a member of the Toll-interleukin receptor/nucleotide-binding site/leucine-rich repeat class of plant resistance proteins that restricts nodulation by S. fredii strains USDA257 and USDA205, and an allelic variant of this gene also restricts nodulation by Bradyrhizobium japonicum USDA122. By means of complementation tests and CRISPR/Cas9-mediated gene knockouts, we demonstrate that the Rfg1 allele also is responsible for resistance to nodulation by S. fredii USDA193. Therefore, the Rfg1 allele likely provides broad-spectrum resistance to nodulation by many S. fredii and B. japonicum strains in soybeans

As demências na perspectiva do familiar à luz da teoria das incertezas de Mishel

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ceilândia, Programa de Pós-Graduação em Ciências e Tecnologias em Saúde, 2017.INTRODUÇÃO: A incerteza em relação à doença é considerada como a inabilidade da pessoa em determinar o significado dos eventos relacionados ao fenômeno da doença. A teoria de Mishel trata das incertezas na doença e sugere que as incertezas sejam encaradas como forma de crescimento. O fenômeno das demências, é visto atualmente como um problema de saúde pública e atinge não apena o doente, mas também os familiares, principalmente aqueles que participam diretamente do cuidado. OBJETIVO: Invetigar a incerteza na doença na perspectiva do familiar do individuo com demência sob a ótica da Teoria de Mishel. MÉTODO: Trata-se de um estudo exploratório e descritivo, de corte transversal realizado em em Brasília/DF, na Associação Brasileira de Alzheimer (ABRAz-DF). Participaram os familiares de indivíduos com diagnostico de demência e que participavam das reuniões de apoio da associação. Os dados foram coletados a partir de dois instrumentos, o sócio demográfico e a Escala de Incerteza de Merle Mishel. RESULTADOS: Dentre os quatro domínios da incerteza mensurados (ambiguidade, falta de clareza, falta de informação e imprevisibilidade), constatou-se que 70% (14) dos familiares relataram sentimento de ambiguidade em relação a melhora, ao tratamento, as medicações. Assim como, o sentimento de ambiguidade em relação a quem cuidará do individuo com demência. Da mesma forma em relação ao domínio da imprevisibilidade. O maior grau de incerteza concentrou-se no domínio ambiguidade e imprevisibilidade envolvendo a tomada de decisões e incertezas relacionadas ao futuro do doente. CONCLUSÃO: Pode-se concluir que a incerteza dos familiares estão associados às questões vinculadas ao futuro, pela evolução da doença ser imprevisível, e assim os familiares não conseguem fazer planos futuros de curto e longo prazo, e preocupam-se com a capacidade de desenvolver os cuidados necessários, tais incertezas podem ser amenizadas com esclarecimentos de profissionais de saúde e redes de apoio.INTRODUCTION: The uncertainty regarding the disease is considered as the inability of the person to determine the meaning of the events related to the phenomenon of the disease. Mishel's theory addresses uncertainties in the disease and suggests that uncertainties are viewed as a form of growth. The phenomenon of dementia is currently seen as a public health problem and affects not only the patient, but also the relatives, especially those who participate directly in the care. OBJECTIVE: To investigate the uncertainty in the disease from the family perspective of the individual with dementia from the perspective of the Mishel Theory. METHOD: This is an exploratory and descriptive cross-sectional study carried out in Brasília / DF, at the Brazilian Association of Alzheimer's (ABRAz-DF). Family members of individuals diagnosed with dementia participated in the association's support meetings. Data were collected from two instruments, the demographic partner and the Merle Mishel Uncertainty Scale. RESULTS: Among the four areas of uncertainty measured (ambiguity, lack of clarity, lack of information and unpredictability), it was found that 70% (14) of family members reported a feeling of ambiguity regarding improvement, treatment and medications. As well as the feeling of ambiguity towards who will take care of the individual with dementia. Likewise in relation to the domain of unpredictability. The greater degree of uncertainty focused on the ambiguity and unpredictability domain involving decision-making and uncertainties related to the patient's future. CONCLUSION: It can be concluded that family members' uncertainty is associated with issues related to the future, the evolution of the disease is unpredictable, and thus, family members can not make future plans for the short and long term, and are concerned with the capacity to develop the necessary care, such uncertainties can be softened with clarifications from health professionals and support networks

Are narcissists more creative? Only if we believe it: How narcissism can relate to creativity

The relationship between narcissism and creativity has inspired interesting debates for decades. Drawing on a new perspective, the current study tried to explain how narcissism influences others’ creativity evaluation in the organizational context. Based on the theory of impression management, we suggested that narcissism and creativity may have a more complex relationship rather than a simple linear link. To test this relationship, we conducted a survey of 596 subordinates and 60 leaders in three high-technology companies. The result showed that there was an inverted U-shaped relationship between narcissism and creativity evaluation. Moreover, personal reputation mediated this curvilinear relationship and this relationship was significant only when narcissists were low in political skill. Theoretical and practical implications, limitations and future directions have also been discussed