Nano-mechanical properties of Fe-Mn-Al-C lightweight steels

High Al Low-density steels could have a transformative effect on the light-weighting of steel structures for transportation and achieving the desired properties with the minimum amount of Ni is of great interest from an economic perspective. In this study, the mechanical properties of two duplex low-density steels, Fe-15Mn-10Al-0.8C-5Ni and Fe-15Mn-10Al-0.8C (wt.%) were investigated through nano-indentation and simulation through utilization of ab initio formalisms in Density Functional Theory (DFT) in order to establish the hardness resulting from two critical structural features (ߢ-carbides and B2 intermetallic) as a function of annealing temperature (500 − 1050 ℃) and the addition of Ni. In the Ni-free sample, the calculated elastic properties of kappa-carbides were compared with those of the B2 intermetallic Fe3Al − L12, and the role of Mn in the kappa structure and its elastic properties were studied. The Ni-containing samples were found to have a higher hardness due to the B2 phase composition being NiAl rather than FeAl, with Ni-Al bonds reported to be stronger than the Fe-Al bonds. In both samples, at temperatures of 900 ℃ and above, the ferrite phase contained nano-sized discs of B2 phase, wherein the Ni-containing samples exhibited higher hardness, attributed again to the stronger Ni-Al bonds in the B2 phase. At 700 ℃ and below, the nano-sized B2 discs were replaced by micrometre sized needles of kappa in the Ni-free sample resulting in a lowering of the hardness. In the Ni-containing sample, the entire alpha phase was replaced by B2 stringers, which had a lower hardness than the Ni-Al nano-discs due to a lower Ni content in B2 stringer bands formed at 700 ℃ and below. In addition, the hardness of needle-like kappa-carbides formed in alpha phase was found to be a function of Mn content. Although it was impossible to measure the hardness of cuboid kappa particles in gamma phase because of their nano-size, the hardness value of composite phases, e.g. gamma + kappa was measured and reported. All the hardness values were compared and rationalized by bonding energy between different atoms

Development of a Simple Scoring System for Predicting Discharge Safety from the Medical ICU to Low-Acuity Wards: The Role of the Sequential Organ Failure Assessment Score, Albumin, and Red Blood Cell Distribution Width

Despite advancements in artificial intelligence-based decision-making, transitioning patients from intensive care units (ICUs) to low-acuity wards is challenging, especially in resource-limited settings. This study aimed to develop a simple scoring system to predict ICU discharge safety. We retrospectively analyzed patients admitted to a tertiary hospital’s medical ICU (MICU) between July 2016 and December 2021. This period was divided into two phases for model development and validation. We identified risk factors associated with unexpected death within 14 days of MICU discharge and developed a predictive scoring system that incorporated these factors. We verified the system’s performance using validation data. In the development cohort, 522 patients were discharged from the MICU, and 42 (8.04%) died unexpectedly. In multivariate analysis, the Sequential Organ Failure Assessment (SOFA) score (odds ratio [OR] 1.26, 95% confidence interval [CI] 1.13–1.41), red blood cell distribution width (RDW) (OR 1.20, 95% CI 1.07–1.36), and albumin (OR 0.37, 95% CI 0.16–0.84) were predictors of unexpected death. Each variable was assigned a weighted point in the scoring system, and the area under the curve (AUC) was 0.788 (95% CI 0.714–0.855). The scoring system was performed using an AUC of 0.738 (95% CI 0.653–0.822) in the validation cohort of 343 patients with 9.62% of unexpected deaths. When a cut-off of 0.032 was applied, a sensitivity and a specificity of 81.8% and 55.2%, respectively, were achieved. This simple bedside predictive score for ICU discharge uses the SOFA score, albumin level, and RDW to aid in timely decision-making and optimize critical care facility allocation in resource-limited settings

Information resource preferences by general pediatricians in office settings: a qualitative study

BACKGROUND: Information needs and resource preferences of office-based general pediatricians have not been well characterized. METHODS: Data collected from a sample of twenty office-based urban/suburban general pediatricians consisted of: (a) a demographic survey about participants' practice and computer use, (b) semi-structured interviews on their use of different types of information resources and (c) semi-structured interviews on perceptions of information needs and resource preferences in response to clinical vignettes representing cases in Genetics and Infectious Diseases. Content analysis of interviews provided participants' perceived use of resources and their perceived questions and preferred resources in response to vignettes. RESULTS: Participants' average time in practice was 15.4 years (2–28 years). All had in-office online access. Participants identified specialist/generalist colleagues, general/specialty pediatric texts, drug formularies, federal government/professional organization Websites and medical portals (when available) as preferred information sources. They did not identify decision-making texts, evidence-based reviews, journal abstracts, medical librarians or consumer health information for routine office use. In response to clinical vignettes in Genetics and Infectious Diseases, participants identified Question Types about patient-specific (diagnosis, history and findings) and general medical (diagnostic, therapeutic and referral guidelines) information. They identified specialists and specialty textbooks, history and physical examination, colleagues and general pediatric textbooks, and federal and professional organizational Websites as information sources. Participants with access to portals identified them as information resources in lieu of texts. For Genetics vignettes, participants identified questions about prenatal history, disease etiology and treatment guidelines. For Genetics vignettes, they identified patient history, specialists, general pediatric texts, Web search engines and colleagues as information sources. For Infectious Diseases (ID) vignettes, participants identified questions about patients' clinical status at presentation and questions about disease classification, diagnosis/therapy/referral guidelines and sources of patient education. For ID vignettes, they identified history, laboratory results, colleagues, specialists and personal experience as information sources. CONCLUSION: Content analysis of office-based general pediatricians' responses to clinical vignettes provided a qualitative description of their perceptions of information needs and preferences for information resource for cases in Genetics and Infectious Diseases. This approach may provide complementary information for discovering practitioner's information needs and resource preferences in different contexts

AXR1-ECR1 and AXL1-ECR1 heterodimeric RUB-activating enzymes diverge in function in Arabidopsis thaliana

RELATED TO UBIQUITIN (RUB) modification of CULLIN (CUL) subunits of the CUL-RING ubiquitin E3 ligase (CRL) superfamily regulates CRL ubiquitylation activity. RUB modification requires E1 and E2 enzymes that are analogous to, but distinct from, those activities required for UBIQUITIN (UBQ) attachment. Gene duplications are widespread in angiosperms, and in line with this observation, components of the RUB conjugation pathway are found in multiples in Arabidopsis. To further examine the extent of redundancy within the RUB pathway, we undertook biochemical and genetic characterizations of one such duplication event- the duplication of the genes encoding a subunit of the RUB E1 into AUXIN RESISTANT1 (AXR1) and AXR1-LIKE1 (AXL1). In vitro, the two proteins have similar abilities to function with E1 C-TERMINAL-RELATED1 (ECR1) in catalyzing RUB1 activation and RUB1-ECR1 thioester formation. Using mass spectrometry, endogenous AXR1 and AXL1 proteins were found in complex with 3HA-RUB1, suggesting that AXR1 and AXL1 exist in parallel RUB E1 complexes in Arabidopsis. In contrast, AXR1 and AXL1 differ in ability to correct phenotypic defects in axr1-30, a severe loss-of-function AXR1 mutant, when the respective coding sequences are expressed from the same promoter, suggesting differential in vivo functions. These results suggest that while both proteins function in the RUB pathway and are biochemically similar in RUB-ECR1 thioester formation, they are not functionally equivalent

Leucine-Rich Repeat Kinase 2 (LRRK2) phosphorylates p53 and induces p21WAF1/CIP1 expression

BACKGROUND: Leucine-rich repeat kinase 2 (LRRK2) is a gene in which a mutation causes Parkinson’s disease (PD), and p53 is a prototype tumor suppressor. In addition, activation of p53 in patient with PD has been reported by several studies. Because phosphorylation of p53 is critical for regulating its activity and LRRK2 is a kinase, we tested whether p53 is phosphorylated by LRRK2. RESULTS: LRRK2 phosphorylates threonine (Thr) at TXR sites in an in vitro kinase assay, and the T304 and T377 were identified as putative phosphorylated residues. An increase of phospho-Thr in the p53 TXR motif was confirmed in the cells overexpressing G2019S, and human induced pluripotent stem (iPS) cells of a G2019S carrier. Interactions between LRRK2 and p53 were confirmed by co-immunoprecipitation of lysates of differentiated SH-SY5Y cells. LRRK2 mediated p53 phosphorylation translocalizes p53 predominantly to nucleus and increases p21(WAF1/CIP1) expression in SH-SY5Y cells based on reverse transcription-polymerase chain reaction and Western blot assay results. The luciferase assay using the p21(WAF1/CIP1) promoter-reporter also confirmed that LRRK2 kinase activity increases p21 expression. Exogenous expression of G2019S and the phosphomimetic p53 T304/377D mutants increased expression of p21(WAF1/CIP1) and cleaved PARP, and cytotoxicity in the same cells. We also observed increase of p21 expression in rat primary neuron cells after transient expression of p53 T304/377D mutants and the mid-brain lysates of the G2019S transgenic mice. CONCLUSION: p53 is a LRRK2 kinase substrate. Phosphorylation of p53 by LRRK2 induces p21(WAF1/CIP1) expression and apoptosis in differentiated SH-SY5Y cells and rat primary neurons. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13041-015-0145-7) contains supplementary material, which is available to authorized users

Improving mechanical properties of alginate hydrogel by reinforcement with ethanol treated polycaprolactone nanofibers

Hydrogels offer interesting possibilities in various biomedical applications, including tissue regeneration, drug delivery, and cell therapy, due to excellent biocompatibility and good nutrient and oxygen transportation abilities. However, most of these applications require improvements in mechanical properties and functionalization. In this study, a novel technique for fabricating 3D nanofiber-reinforced hydrogel composites is described as a means of enhancing the strength and durability of hydrogels. The method is based on the layer-by-layer electrospinning of nanofibers on an evenly spread, thin hydrogel solution. A coaxial nozzle was introduced for electrospinning highly wettable ethanol-treated nanofibers. This process enhanced the compatibility between the nanofiber reinforcements and the hydrogel matrix. The compressive strength and stiffness of the resulting nanofiber-reinforced hydrogel composites were enhanced to similar to 221% and similar to 434% compared to the pure hydrogel, respectively. Moreover, the equilibrium modulus was increased by a factor of nearly 1.73 when the volume fraction of nanofibers was 0.085. It was demonstrated that a 3D nanofiber-reinforced hydrogel composite could be fabricated without the cumbersome stacking of hydrogel-coated fiber meshes. Furthermore, the mechanical properties of the reinforced composites can be modulated by adjusting the volume fraction of nanofibers. (c) 2012 Elsevier Ltd. All rights reserved.X112318sciescopu

Temperature-dependent nanomorphology-performance relations in binary iridium complex blend films for organic light emitting diodes

Understanding the mechanism responsible for the temperature-dependent performances of emitting layers is essential for developing advanced phosphorescent organic light emitting diodes. We described the morphological evolution occurring in PVK:Ir(ppy)(3) binary blend films, with respect to thermal annealing up to 300 degrees C, by coupling atomic force microscopy and transmission electron microscopy. In particular, in situ temperature-dependent experimental characterization was performed to directly determine the overall sequence of morphological evolution occurring in the films. The device thermally annealed at 200 degrees C exhibits a noticeable enhancement in the performances, compared to the devices in the as-processed state and to the devices annealed at 300 degrees C. Our approaches reveal that the Ir(ppy)(3) molecules, with a needle-like structure in the as-processed state, were aggregated, and thus diffused into PVK without a morphological change at the temperature regime between 150 degrees C and 200 degrees C. Moreover, both network-like and droplet patterns existed in the devices annealed at 300 degrees C, which was beyond the glass temperature of PVK, leading to a profound increase in the surface roughness. The observed pattern formation is discussed in terms of viscoelastic phase separation. Based on our experimental findings, we propose that the performances of the devices are significantly controlled by the diffusion of dopant molecules and the morphological evolution of the host materials in binary blend systems.1122sciescopu