Kondo correlation and spin-flip scattering in spin-dependent transport through a quantum dot coupled to ferromagnetic leads

We investigate the linear and nonlinear dc transport through an interacting quantum dot connected to two ferromagnetic electrodes around Kondo regime with spin-flip scattering in the dot. Using a slave-boson mean field approach for the Anderson Hamiltonian having finite on-site Coulomb repulsion, we find that a spin-flip scattering always depresses the Kondo correlation at arbitrary polarization strength in both parallel and antiparallel alignment of the lead magnetization and that it effectively reinforces the tunneling related conductance in the antiparallel configuration. For systems deep in the Kondo regime, the zero-bias single Kondo peak in the differential conductance is split into two peaks by the intradot spin-flip scattering; while for systems somewhat further from the Kondo center, the spin-flip process in the dot may turn the zero-bias anomaly into a three-peak structure.Comment: 4 pages, 2 figure

Persistent Biomechanical Alterations After ACL Reconstruction Are Associated With Early Cartilage Matrix Changes Detected by Quantitative MR.

BackgroundThe effectiveness of anterior cruciate ligament (ACL) reconstruction in preventing early osteoarthritis is debated. Restoring the original biomechanics may potentially prevent degeneration, but apparent pathomechanisms have yet to be described. Newer quantitative magnetic resonance (qMR) imaging techniques, specifically T1ρ and T2, offer novel, noninvasive methods of visualizing and quantifying early cartilage degeneration.PurposeTo determine the tibiofemoral biomechanical alterations before and after ACL reconstruction using magnetic resonance imaging (MRI) and to evaluate the association between biomechanics and cartilage degeneration using T1ρ and T2.Study designCohort study; Level of evidence, 2.MethodsKnee MRIs of 51 individuals (mean age, 29.5 ± 8.4 years) with unilateral ACL injuries were obtained prior to surgery; 19 control subjects (mean age, 30.7 ± 5.3 years) were also scanned. Follow-up MRIs were obtained at 6 months and 1 year. Tibial position (TP), internal tibial rotation (ITR), and T1ρ and T2 were calculated using an in-house Matlab program. Student t tests, repeated measures, and regression models were used to compare differences between injured and uninjured sides, observe longitudinal changes, and evaluate correlations between TP, ITR, and T1ρ and T2.ResultsTP was significantly more anterior on the injured side at all time points (P < .001). ITR was significantly increased on the injured side prior to surgery (P = .033). At 1 year, a more anterior TP was associated with elevated T1ρ (P = .002) and T2 (P = .026) in the posterolateral tibia and with decreased T2 in the central lateral femur (P = .048); ITR was associated with increased T1ρ in the posteromedial femur (P = .009). ITR at 6 months was associated with increased T1ρ at 1 year in the posteromedial tibia (P = .029).ConclusionPersistent biomechanical alterations after ACL reconstruction are related to significant changes in cartilage T1ρ and T2 at 1 year postreconstruction. Longitudinal correlations between ITR and T1ρ suggest that these alterations may be indicative of future cartilage injury, leading to degeneration and osteoarthritis.Clinical relevanceNewer surgical techniques should be developed to eliminate the persistent anterior tibial translation commonly seen after ACL reconstruction. qMR will be a useful tool to evaluate the ability of these newer techniques to prevent cartilage changes

Mesoscopic Kondo effect of a quantum dot embedded in an Aharonov-Bohm ring with intradot spin-flip scattering

We study the Kondo effect in a quantum dot embedded in a mesoscopic ring taking into account intradot spin-flip scattering $R$. Based on the finite-$U$ slave-boson mean-field approach, we find that the Kondo peak in the density of states is split into two peaks by this coherent spin-flip transition, which is responsible for some interesting features of the Kondo-assisted persistent current circulating the ring: (1) strong suppression and crossover to a sine function form with increasing $R$; (2) appearance of a "hump" in the $R$-dependent behavior for odd parity. $R$-induced reverse of the persistent current direction is also observed for odd parity.Comment: 7 pages,6 figures, to be published by Europhys. Let

The plastidial retrograde signal methyl erythritol cyclopyrophosphate is a regulator of salicylic acid and jasmonic acid crosstalk.

The exquisite harmony between hormones and their corresponding signaling pathways is central to prioritizing plant responses to simultaneous and/or successive environmental trepidations. The crosstalk between jasmonic acid (JA) and salicylic acid (SA) is an established effective mechanism that optimizes and tailors plant adaptive responses. However, the underlying regulatory modules of this crosstalk are largely unknown. Global transcriptomic analyses of mutant plants (ceh1) with elevated levels of the stress-induced plastidial retrograde signaling metabolite 2-C-methyl-D-erythritol cyclopyrophosphate (MEcPP) revealed robustly induced JA marker genes, expected to be suppressed by the presence of constitutively high SA levels in the mutant background. Analyses of a range of genotypes with varying SA and MEcPP levels established the selective role of MEcPP-mediated signal(s) in induction of JA-responsive genes in the presence of elevated SA. Metabolic profiling revealed the presence of high levels of the JA precursor 12-oxo-phytodienoic acid (OPDA), but near wild type levels of JA in the ceh1 mutant plants. Analyses of coronatine-insensitive 1 (coi1)/ceh1 double mutant plants confirmed that the MEcPP-mediated induction is JA receptor COI1 dependent, potentially through elevated OPDA. These findings identify MEcPP as a previously unrecognized central regulatory module that induces JA-responsive genes in the presence of high SA, thereby staging a multifaceted plant response within the environmental context

Energy Efficiency-Spectral Efficiency Trade-Off of Transmit Antenna Selection

We investigate the energy efficiency-spectral efficiency (EE-SE) trade-off of transmit antenna selection/maximum ratio combining (TAS) scheme. A realistic power consumption model (PCM) is considered, and it is shown that using TAS can provide significant energy savings when compared to multiple-input multiple-output (MIMO) in the low to medium SE region, regardless the number of antennas, as well as outperform transmit beamforming scheme (MRT) for the entire SE range. For a fixed number of receive antennas, our results also show that the EE gain of TAS over MIMO becomes even greater as the number of transmit antennas increases. The optimal value of SE that maximizes the EE is obtained analytically, and confirmed by numerical results. Moreover, the influence of receiver correlation is also evaluated and it is shown that considering a non-realistic PCM can lead to mistakes when comparing TAS and MIMO

Evaluation of decellularization of porcine pericardium: Decellularization of porcine pericardium

The porcine pericardium has been used for its great potential as a biological scaffold, produced from the extracellular matrix (ECM) and used mainly in surgeries reconstructive, tissue repair and surgical procedures for corneal reconstruction. The adequate preservation and biocompatibility of the pericardial ECM structure during the decellularization process is fundamental, the biggest challenge being the total removal of cellular material without damage to the structure. All agents used in decellularization change the composition and cause some damage to the ultrastructure. Sodium Dodecil Sulfate (SDS) is the most effective for removing cell residue from tissue compared to other detergents, which is also the most used for the decellularization process. This work aimed to test 3 different concentrations of SDS, in order to assess the concentration (0.1, 0.5 and 1%) that best preserves the structure of the ECM pericardial. In addition, we listed the type of daily wash to make the process more effective (only distilled water or PBS 1x), in order to assess the concentration capable of decellularizing the tissue and better preserving the pericardial ECM. The concentration of SDS at 1%, when compared to the lowest concentrations of 0.1 and 0.5%, was more effective in the decellularization process, however it did not obtain good results in the preservation of the ECM. Regarding daily washing, there was no difference in the frequency assessed in the experimental groups

Eficácia dos exercícios para ombro nas complicações loco-regionais em mulheres submetidas a radioterapia para câncer de mama: ensaio clínico

OBJECTIVE: To investigate the effect of shoulder exercises during radiotherapy in relation to prevention of locoregional physical complications: limitation of range of motion (ROM) and functional capacity, arm circumference and scar tissue adhesion. METHODS: Sixty-six women without shoulder ROM impairment following breast cancer surgery that included complete axillary dissection were allocated to one of two groups: 32 in the physical therapy group (PG) (52.7±10.2 years), who underwent an exercise program; and 34 in the control group (CG) (48±10.1 years). Shoulder ROM, upper-limb circumference and functional capacity and scar tissue adhesion were evaluated at the beginning and end of radiotherapy and six months after completing radiotherapy. RESULTS: The PG showed improvements in flexion and abduction ROM between the first and third evaluations (flexion from 164.77°±8.9° to 167.98°±9.5° and abduction from 168.56°±10.0° to 175.62°±10.2°), which was not observed in the CG (flexion from 167.06±06° to 165.16°±9.2° and abduction from 169.71°±10.1° to 169.53°±12.8°). There was a statistically significant increase in ROM in the PG in relation to the CG (flexion, p=0.02; and abduction, p=0.004). The circumference and functional capacity were similar between the groups and the frequency of scar tissue adhesion in the CG was twice that observed in the PG (48% versus 24%, p=0.04). CONCLUSIONS: These results suggest that shoulder exercises favor maintenance of flexion and abduction ROM of the shoulder and minimize the incidence of scar tissue adhesion in women undergoing radiotherapy for breast cancer treatment.OBJETIVO: Verificar o efeito da realização de exercícios para o ombro durante a radioterapia na prevenção de complicações físicas loco-regionais: limitação da amplitude de movimento (ADM) e da capacidade funcional, circunferência do braço e aderência cicatricial. MÉTODOS: Sessenta e seis mulheres sem comprometimento de ADM de ombro no pós-operatório de cirurgia para câncer de mama com dissecção axilar completa foram alocadas em dois grupos, sendo 32 no grupo de fisioterapia (GF) (52,7±10,2 anos), o qual foi submetido a um programa de exercícios, e 34 no grupo controle (GC) (48±10,1 anos). A ADM do ombro, a circunferência e capacidade funcional dos membros superiores e a aderência cicatricial foram avaliados no início e no final da radioterapia e seis meses após seu término. RESULTADOS: O GF apresentou melhora da ADM de flexão e abdução entre a primeira e terceira avaliação (Flexão: de 164,77°±8,9° para 167,98°±9,5° e Abdução: 168,56°±10° para 175,62°±10,2°), o que não se observou no GC (Flexão: 167,06°±6° para 165,16°±9,2° e Abdução: 169,71°±10,1° para 169,53°±12,8°), demonstrando uma melhora significativa do GF em relação do GC (Flexão: p=0,02 e Abdução: p=0,004). A circunferência e a capacidade funcional foram similares entre os grupos e a frequência de aderência cicatricial no GC foi o dobro daquela observada no GF (48% e 24%, p=0,04). CONCLUSÕES: Esses resultados sugerem que exercícios para o ombro favorecem a manutenção da ADM de flexão e abdução de ombro e minimizam a incidência de aderência cicatricial em mulheres submetidas à radioterapia para tratamento por câncer de mama.13614

Seed Coating: A Tool for Delivering Beneficial Microbes to Agricultural Crops

Plant beneficial microbes (PBMs), such as plant growth-promoting bacteria, rhizobia, arbuscular mycorrhizal fungi, and Trichoderma, can reduce the use of agrochemicals and increase plant yield, nutrition, and tolerance to biotic-abiotic stresses. Yet, large-scale applications of PBM have been hampered by the high amounts of inoculum per plant or per cultivation area needed for successful colonization and consequently the economic feasibility. Seed coating, a process that consists in covering seeds with low amounts of exogenous materials, is gaining attention as an efficient delivery system for PBM. Microbial seed coating comprises the use of a binder, in some cases a filler, mixed with inocula, and can be done using simple mixing equipment (e.g., cement mixer) or more specialized/sophisticated apparatus (e.g., fluidized bed). Binders/fillers can be used to extend microbial survival. The most reported types of seed coating are seed dressing, film coating, and pelleting. Tested in more than 50 plant species with seeds of different dimensions, forms, textures, and germination types (e.g., cereals, vegetables, fruits, pulses, and other legumes), seed coating has been studied using various species of plant growth-promoting bacteria, rhizobia, Trichoderma, and to a lesser extent mycorrhizal fungi. Most of the studies regarding PBM applied via seed coating are aimed at promoting crop growth, yield, and crop protection against pathogens. Studies have shown that coating seeds with PBM can assist crops in improving seedling establishment and germination or achieving high yields and food quality, under reduced chemical fertilization. The right combination of biological control agents applied via seed coating can be a powerful tool against a wide number of diseases and pathogens. Less frequently, studies report seed coating being used for adaptation and protection of crops under abiotic stresses. Notwithstanding the promising results, there are still challenges mainly related with the scaling up from the laboratory to the field and proper formulation, including efficient microbial combinations and coating materials that can result in extended shelf-life of both seeds and coated PBM. These limitations need to be addressed and overcome in order to allow a wider use of seed coating as a cost-effective delivery method for PBM in sustainable agricultural systems.info:eu-repo/semantics/publishedVersio

Using microbial seed coating for improving cowpea productivity under a low‐input agricultural system

BACKGROUND Plant‐growth‐promoting rhizobacteria (PGPR) and arbuscular mycorrhizal (AM) fungi have the ability to enhance the growth, fitness, and quality of various agricultural crops, including cowpea. However, field trials confirming the benefits of microbes in large‐scale applications using economically viable and efficient inoculation methods are still scarce. Microbial seed coating has a great potential for large‐scale agriculture through the application of reduced amounts of PGPR and AM fungi inocula. Thus, in this study, the impact of seed coating with PGPR, Pseudomonas libanensis TR1 and AM fungus, Rhizophagus irregularis (single or multiple isolates) on grain yield and nutrient content of cowpea under low‐input field conditions was evaluated. RESULTS Seed coating with P. libanensis + multiple isolates of R. irregularis (coatPMR) resulted in significant increases in shoot dry weight (76%), and in the number of pods and seeds per plant (52% and 56%, respectively) and grain yield (56%), when compared with non‐inoculated control plants. However, seed coating with P. libanensis + R. irregularis single‐isolate (coatPR) did not influence cowpea grain yield. Grain lipid content was significantly higher (25%) in coatPMR plants in comparison with control. Higher soil organic matter and lower pH were observed in the coatPMR treatment. CONCLUSIONS Our findings indicate that cowpea field productivity can be improved by seed coating with PGPR and multiple AM fungal isolates under low‐input agricultural systems. © 2019 Society of Chemical Industryinfo:eu-repo/semantics/publishedVersio