Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)

The recently discovered iron arsenide superconductors, which display superconducting transition temperatures as high as 55 K, appear to share a number of general features with high-Tc cuprates, including proximity to a magnetically ordered state and robustness of the superconductivity in the presence of disorder. Here we show that superconductivity in Fe1+dSe, the parent compound of the superconducting arsenide family, is destroyed by very small changes in stoichiometry. Further, we show that non-superconducting Fe1+dSe is not magnetically ordered down to low temperatures. These results suggest that robust superconductivity and immediate instability against an ordered magnetic state should not be considered as intrinsic characteristics of iron-based superconducting systems, and that Fe1+dSe may present a unique opportunity for determining which materials characteristics are critical to the existence of superconductivity in high Tc iron arsenide superconductors and which are not.Comment: Updated to reflect final version and include journal referenc

The nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze

Background and Objectives: The aim of this research is study the nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze. With the expansion of e-learning, one of the important aspects of change in education is in the field of teaching and learning, including the relation between the teacher and the learner. In the analysis and evaluation of the nature of the relation and its role in human cognition, one of the post structuralist emerging paradigms is Deleuze's rhizomatic epistemology. In the area of Deleuze's ideas and electronic learning based on connectivism theory, separate researches have been done. However, what distinguishes this study from other studies is the assessment of the important fact that whether the new area which Deleuze names rhizomatic and by which means challenges the traditional relationships between the teacher and the learner in the tree system and deterritorializes can support the new atmosphere of electronic learning. Do these two accompany each other? MethodS:The methodology of this study is philosophical analysis and deduction, which were used to answer the research question (What is the nature of the relation between the teacher and the learner in the process of e-learning?). The method of data collection is desk-documentation study. Based on concept analysis, valid understanding of the concept and a clear explanation of its relationship with other concepts was achieved. Moreover, based on deductive approach, the implications of the nature of the relation between the teacher and the learner according to Deleuze's ideas in the process of teaching - learning in e-learning was assessed. Then, these were analyzed philosophically. In other words, Deleuze's rhizomatic epistemological concepts and the related elements on the one hand and the concepts of electronic learning based on connectivism theory on the other hand were analyzed, interpreted and clarified. In the end, the proportion of relation in e-learning to Deleuze's rhizomatic relation was evaluated.  Findings: First, basic factors in rhizomatic epistemology of Deleuze were investigated. Based on the findings of this study, the essentialistic of the relationship between the teacher and the learner, according to Deleuze’s opinions, is rhizomatic. This means that it has features such as Interconnection and heterogeneity, pluralism, immigration, mapping, and non-indicative dissociation of rhizome, suggesting nonlinear, horizontal and non-hierarchical, fluid and fragile, decentralizing, spontaneous and molecular, dense and multiplexed, flexible and permeable relationships. Second, the nature of relationship in virtual learning process was illuminated according to the principles of communication theory, which is the new theory of learning in the age of information and communication technology, communication in E-learning is a systemic and network communication that has nonlinear relationships among system components and network.According to this theory, E-learning is the process of network components communicating with each other. At the end, the nature of relationship virtual Learning in relation with, the nature of rhizomatic epistemology of Deleuze was examined Therefore, the orientation of communication in E-learning is in line with Deleuze's rhizomatic relationship. Conclusion: Based on connectivism theory, electronic education is the very process of network elements connecting with each other. Thus, the direction of e-learning is aligned with Deleuze's rhizomatic relation. Thus, Deleuze's rhizomatic relationships with regard to the capabilities it holds, promises the ideal relationship between the teacher and the learner in the E-learning era and can serve as a model to address some of the challenges of the traditional educational system.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Effect of Application of Plant Growth Promoting Bacteria and Amino Acids Foliar Application on Growth Characteristics, Yield, and Nutritional Value of Rice (Oryza sativa L.)

Introduction Rice (Oryza sativa L.), as one of the most important cereals, is the main food of more than 50% of the world's population. Excessive use of chemical fertilizers in paddy fields has caused many environmental problems. Therefore, the application of biological fertilizers instead of chemical fertilizers to increase the yield of crops and produce more food is one of the important goals of sustainable agriculture, which is necessary for human life. Bacteria is an example of biological fertilizer used in agriculture, which plays an important role in improving soil structure, improving plant growth, and increasing the quantitative and qualitative yield of crops. Another biological stimulant of plants is amino acids, which can increase plant growth, improve nutrients uptake, and increase grain yield and grain quality of crops. Methionine is the precursor of growth regulators such as auxin, cytokinin, and brassinosteroids and is known as the most important growth-limiting amino acid in plants. Lysine is an essential amino acid that is involved in the germination of pollen grains, chlorophyll synthesis, and crop production. Therefore, the present study aimed to evaluate the effects of different strains of plant growth-promoting bacteria and amino acids on growth, yield, and concentration of nutrients in rice.Materials and Methods The field experiment was arranged as a split-plot in a randomized complete block design with three replications at the farmer's field located in Mazandaran province, Amol during 2019-2020 cropping seasons. In the present research, the plant growth-promoting bacteria at five levels (control or without bacteria [B0], P. agglomerans strain O4 [B1], P. putida strain P13 + P. agglomerans strain P5 [B2], P. koreensis strain S14 + P. vancouverensis strain S19 [B3] and combination of different strains [B4]) as the main factor and amino acids foliar application in four levels (control or without amino acids [A0], methionine [A1], lysine [A2] and methionine + lysine [A3]) as the sub-factor were considered. The plant growth-promoting bacteria at the rate of 100 g.ha-1 and amino acids at a concentration of 2.5 per thousand were applied in this study. At physiological maturity, the growth, yield components, grain yield, and nutrients uptake (NPK) in grain were measured. A combined analysis of variance was performed using SAS software version 9.2. Mean values were compared using least significant difference (LSD) test at 5% probability level.Results and DiscussionThe outcomes established that the bacteria treatment exerted a notable impact on all examined traits, excluding the count of fertile tillers per hill. Equally noteworthy, the amino acid intervention displayed significance in terms of 1000-grain weight, grain yield, and nitrogen concentration in rice grains. However, the interaction between bacteria and amino acids exhibited no significance across the quantitative and qualitative characteristics of rice. The concurrent utilization of bacteria strains, specifically B4, yielded substantial enhancements in panicle length (24.22 cm), the count of filled grains per panicle (60.30 filled grains), 1000-grain weight (28.52 g), grain yield (5097.50 kg.ha-1), and the amelioration of nutrients concentrations. Notably, nutrients like nitrogen (1.61%), phosphorus (7.04%), and potassium (1.53%) exhibited improvements in rice grains, in comparison to instances involving separate strain applications and the control group. Simultaneous foliar application of methionine and lysine amino acids resulted in maximum 1000-grain weight (26.90 g), highest grain yield (4844.73 kg.ha-1), and production of the greatest nitrogen content in grain (1.40%). In the present research, the increase in grain yield by combined application of different bacteria strains might be due to enhancing growth, improving yield components such as 1000-grain weight and filled grains number per panicle, and increasing nutrients concentration (NPK) in rice. Also, the simultaneous foliar application of methionine and lysine led to an increase in rice grain yield through increasing 1000-grain weight and improving nitrogen uptake in rice grains.ConclusionAccording to the results of this experiment, the combined application of the bacteria strains (P. agglomerans strain O4 + P. putida strain P13 + P. agglomerans strain P5 + P. koreensis strain S14 + P. vancouverensis strain S19) and simultaneous foliar application of methionine and lysine can play an important role in improving growth, yield and nutrients uptake in rice grains

Distinct but overlapping roles of LRRTM1 and LRRTM2 in developing and mature hippocampal circuits

LRRTMs are postsynaptic cell adhesion proteins that have region-restricted expression in the brain. To determine their role in the molecular organization of synapses in vivo, we studied synapse development and plasticity in hippocampal neuronal circuits in mice lacking both Lrrtm1 and Lrrtm2. We found that LRRTM1 and LRRTM2 regulate the density and morphological integrity of excitatory synapses on CA1 pyramidal neurons in the developing brain but are not essential for these roles in the mature circuit. Further, they are required for long-term-potentiation in the CA3-CA1 pathway and the dentate gyrus, and for enduring fear memory in both the developing and mature brain. Our data show that LRRTM1 and LRRTM2 regulate synapse development and function in a cell-type and developmental-stage-specific manner, and thereby contribute to the fine-tuning of hippocampal circuit connectivity and plasticity

Structure-based design and synthesis of antiparasitic pyrrolopyrimidines targeting pteridine reductase 1

The treatment of Human African Trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important and pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp. has been identified as a candidate target and it has been shown previously that substituted pyrrolo[2,3-d]pyrimidines are inhibitors of PTR1 from T. brucei (J. Med. Chem. 2010, 53, 221-229). In this study, 61 new pyrrolo[2,3-d]pyrimidines have been prepared, designed with input from new crystal structures of 23 of these compounds complexed with PTR1, and evaluated in screens for enzyme inhibitory activity against PTR1 and in vitro antitrypanosomal activity. 8 compounds were sufficiently active in both screens to take forward to in vivo evaluation. Thus although evidence for trypanocidal activity in a stage I disease model in mice was obtained, the compounds were too toxic to mice for further development

Nanostructured carriers as innovative tools for cancer diagnosis and therapy

Cancer accounts for millions of deaths every year and, due to the increase and aging of the world population, the number of new diagnosed cases is continuously rising. Although many progresses in early diagnosis and innovative therapeutic protocols have been already set in clinical practice, still a lot of critical aspects need to be addressed in order to efficiently treat cancer and to reduce several drawbacks caused by conventional therapies. Nanomedicine has emerged as a very promising approach to support both early diagnosis and effective therapy of tumors, and a plethora of different inorganic and organic multifunctional nanomaterials have been ad hoc designed to meet the constant demand for new solutions in cancer treatment. Given their unique features and extreme versatility, nanocarriers represent an innovative and easily adaptable tool both for imaging and targeted therapy purposes, in order to improve the specific delivery of drugs administered to cancer patients. The current review reports an in-depth analysis of the most recent research studies aiming at developing both inorganic and organic materials for nanomedical applications in cancer diagnosis and therapy. A detailed overview of different approaches currently undergoing clinical trials or already approved in clinical practice is provided

Reproducibility of the mfERG between instruments

Purpose First, to examine both the reproducibility of the multifocal electroretinogram (mfERG) recorded on different versions of the same instrument, and the repeatability of the mfERG recorded on a single instrument using two different amplifiers. Second, to demonstrate a means by which multicenter and longitudinal studies that use more than one recording instrument can compare and combine data effectively. Methods Three different amplifiers and two mfERG setups, one using VERIS™ 4.3 software (mfERG1) and another using VERIS™ Pro 5.2 software (mfERG2), were evaluated. A total of 73 subjects with normal vision were tested in three groups. Group 1 (n = 42) was recorded using two amplifiers in parallel on mfERG1. Group 2 (n = 52) was recorded on mfERG2 using a single amplifier. Group 3 was a subgroup of 21 subjects from groups 1 and 2 that were tested sequentially on both instruments. A fourth group of 26 subjects with diabetes were also recorded using the two parallel amplifiers on mfERG1. P1 implicit times and N1-P1 amplitudes of the 103 local first order mfERGs were measured, and the differences between the instruments and amplifiers were evaluated as raw scores and Z-scores based on normative data. Measurements of individual responses and measurements averaged over the 103 responses were analyzed. Results Simultaneous recordings made on mfERG1 with the two different amplifiers showed differences in implicit times but similar amplitudes. There was a mean implicit time difference of 2.5 ms between the amplifiers but conversion to Z-scores improved their agreement. Recordings made on different days with the two instruments produced similar but more variable results, with amplitudes differing between them more than implicit times. For local response implicit times, the 95% confidence interval of the difference between instruments was approximately ±1 Z-score (±0.9 ms) in either direction. For local response amplitude, it was approximately ±1.6 Z-scores (±0.3 μV). Conclusions Different amplifiers can yield quite different mfERG P1 implicit times, even with identical band-pass settings. However, the reproducibility of mfERG Z-scores across recording instrumentation is relatively high. Comparison of data across systems and laboratories, necessary for multicenter or longitudinal investigations, is facilitated if raw data are converted into Z-scores based on normative data

Lobular Carcinomas In Situ Display Intralesion Genetic Heterogeneity and Clonal Evolution in the Progression to Invasive Lobular Carcinoma

Purpose:; Lobular carcinoma; in situ; (LCIS) is a preinvasive lesion of the breast. We sought to define its genomic landscape, whether intralesion genetic heterogeneity is present in LCIS, and the clonal relatedness between LCIS and invasive breast cancers.; Experimental Design:; We reanalyzed whole-exome sequencing (WES) data and performed a targeted amplicon sequencing validation of mutations identified in 43 LCIS and 27 synchronous more clinically advanced lesions from 24 patients [9 ductal carcinomas; in situ; (DCIS), 13 invasive lobular carcinomas (ILC), and 5 invasive ductal carcinomas (IDC)]. Somatic genetic alterations, mutational signatures, clonal composition, and phylogenetic trees were defined using validated computational methods.; Results:; WES of 43 LCIS lesions revealed a genomic profile similar to that previously reported for ILCs, with; CDH1; mutations present in 81% of the lesions. Forty-two percent (18/43) of LCIS were found to be clonally related to synchronous DCIS and/or ILCs, with clonal evolutionary patterns indicative of clonal selection and/or parallel/branched progression. Intralesion genetic heterogeneity was higher among LCIS clonally related to DCIS/ILC than in those nonclonally related to DCIS/ILC. A shift from aging to APOBEC-related mutational processes was observed in the progression from LCIS to DCIS and/or ILC in a subset of cases.; Conclusions:; Our findings support the contention that LCIS has a repertoire of somatic genetic alterations similar to that of ILCs, and likely constitutes a nonobligate precursor of breast cancer. Intralesion genetic heterogeneity is observed in LCIS and should be considered in studies aiming to develop biomarkers of progression from LCIS to more advanced lesions