Comparative transcriptome analysis of two Daphnia galeata genotypes displaying contrasting phenotypic variation induced by fish kairomones in the same environment of the Han River, Korea.

BACKGROUND: Phenotypic plasticity is a crucial adaptive mechanism that enables organisms to modify their traits in response to changes in their environment. Predator-induced defenses are an example of phenotypic plasticity observed across a wide range of organisms, from single-celled organisms to vertebrates. In addition to morphology and behavior, these responses also affect life-history traits. The crustacean Daphnia galeata is a suitable model organism for studying predator-induced defenses, as it exhibits life-history traits changes under predation risk. To get a better overview of their phenotypic plasticity under predation stress, we conducted RNA sequencing on the transcriptomes of two Korean Daphnia galeata genotypes, KE1, and KB11, collected in the same environment. RESULTS: When exposed to fish kairomones, the two genotypes exhibited phenotypic variations related to reproduction and growth, with opposite patterns in growth-related phenotypic variation. From both genotypes, a total of 135,611 unigenes were analyzed, of which 194 differentially expressed transcripts (DETs) were shared among the two genotypes under predation stress, which showed consistent, or inconsistent expression patterns in both genotypes. Prominent DETs were related to digestion and reproduction and consistently up-regulated in both genotypes, thus associated with changes in life-history traits. Among the inconsistent DETs, transcripts encode vinculin (VINC) and protein obstructor-E (OBST-E), which are associated with growth; these may explain the differences in life-history traits between the two genotypes. In addition, genotype-specific DETs could explain the variation in growth-related life-history traits between genotypes, and could be associated with the increased body length of genotype KE1. CONCLUSIONS: The current study allows for a better understanding of the adaptation mechanisms related to reproduction and growth of two Korean D. galeata genotypes induced by predation stress. However, further research is necessary to better understand the specific mechanisms by which the uncovered DETs are related with the observed phenotypic variation in each genotype. In the future, we aim to unravel the precise adaptive mechanisms underlying predator-induced responses.

Ruegeria spongiae sp. nov., isolated from Callyspongia elongata.

A Gram-stain-negative, rod-shaped, polar flagellated, aerobic, light-yellow bacterium, designated as 2012CJ41-6T, was isolated from a sponge sample of Callyspongia elongata from Chuja-myeon, Jeju-si, Jeju-do, Republic of Korea. On the basis of 16S rRNA gene sequencing, strain 2012CJ41-6T clustered with species of the genus Ruegeria and appeared closely related to R. halocynthiae DSM 27839T (96.46 % similarity), R. denitrificans CECT 4357T (96.32 %), R. profundi ZGT108T (96.32 %), R. litorea CECT 7639T (96.32 %) and R. atlantica CECT 4292T (96.16 %). The average nucleotide identity and digital DNA-DNA hybridization between strain 2012CJ41-6T and the most closely related strain was 75.3 % and 19.6 %, indicating that 2012CJ41-6T represents a novel species of the genus Ruegeria. Growth occurred at 15-37 °C on marine medium in the presence of 0.5-10 % (w/v) NaCl and at pH 5.5-8.5. The DNA G+C content of the genomic DNA was 60.80 mol%, and ubiquinone-10 (Q-10) was the major respiratory quinone. The major cellular fatty acids (>5 %) were C18 : 1 ω7c and/or C18:1 ω6c (summed feature 8). The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified aminolipid, one unidentified aminophospholipid and five unidentified lipids. Physiological and biochemical characteristics indicated that strain 2012CJ41-6T represents a novel species of the genus Ruegeria, for which the name Ruegeria spongiae sp. nov. is proposed. The type strain is 2012CJ41-6T (=KACC 22645T=LMG 32585T).

A Study on Dislocation Mechanisms of Toughening in Cu-Graphene Nanolayered Composite.

We investigated the role of graphene interfaces in strengthening and toughening of the Cu-graphene nanocomposite by a combination of in situ transmission electron microscopy (TEM) deformation and molecular dynamics (MD) simulations. In situ TEM directly showed that dislocation plasticity is strongly confined within single Cu grains by the graphene interfaces and grain boundaries. The weak Cu-graphene interfacial bonding induces stress decoupling, which results in independent plastic deformation of each Cu layer. As confirmed by the MD simulation, the localized deformation made by such constrained dislocation plasticity results in the nucleation and growth of voids at the graphene interface, which acts as a precursor for crack. The graphene interfaces also effectively block crack propagation promoted by easy delamination of Cu layers dissipating the elastic strain energy. The toughening mechanisms revealed by the present study will provide valuable insights into the optimization of the mechanical properties of metal-graphene nanolayered composites.

100 years after Griffith: From brittle bulk fracture to failure in 2D materials.

Brittle fracture and ductile failure are critical events for any structural or functional component, as it marks the end of lifetime and potential hazard to human life. As such, materials scientists continuously strive to better understand and subsequently avoid these events in modern materials. A century after the seminal initial contribution by Griffith, fracture mechanics has come a long way and is still experiencing vivid progress. Building on classical fracture testing standards, advanced in situ fracture experiments allow local quantitative probing of fracture processes on different length scales, while microscopic analysis grants access to chemical and structural information along fracture paths in previously unseen detail. This article will provide an overview of how these modern developments enhance our understanding of local fracture processes and highlight future trends toward designing strong yet ductile and damage-tolerant materials.

Friction Control by Deformation Mode in Nanopatterned Amorphous Carbon.

Traditionally, the manipulation of contact mechanisms has been adopted as the primary strategy to tailor the friction properties of surfaces. On the contrary, the detaching process involving the local deformation and failure at the interface has been considered relatively less important. Here, we present a new approach toward the friction control of amorphous carbon through the plasticity and resultant transition of deformation mode on nanopatterned surfaces. Depending on the topography of the nanopatterns, the mechanical responses of the surfaces alter from elastic fracture to plastic flow, through which the friction coefficient changes by a factor of 5 without manipulation of the intrinsic structure of the material.

Reversed Anionic Hofmeister Effect in Metal-Phenolic-Based Film Formation.

Although metal-phenolic species have emerged as one of the versatile material-independent-coating materials, providing attractive tools for interface engineering, mechanistic understanding of their film formation and growth still remains largely unexplored. Especially, the anions have been overlooked despite their high concentration in the coating solution. Considering that the anions are critical in the reactivity of metal-organic complex and the formation and/or property of functional materials, we investigated the anionic effects on the characteristics of film formation, such as film thickness and properties, in the Fe3+-tannic acid coating. We found that the film characteristics were strongly dictated by the counteranions (e.g., SO42-, Cl-, and Br-) of the Fe3+ ion. Specifically, the film thickness and properties (i.e., mechanical modulus, permeability, and stability) followed the reversed anionic Hofmeister series (Br- > Cl- > SO42-). Mechanistic studies suggested that more chaotropic anions, such as Br-, might induce a more widely extended structure of the Fe3+-TA complexes in the coating solution, leading to thicker, harder, but more porous films. The reversed anionic Hofmeister effect was further confirmed by the additive effects of various sodium salts (NaF, NaCl, NaBr, and NaClO4).

Impact of Remote Consultations on Antibiotic Prescribing in Primary Health Care: Systematic Review.

BACKGROUND: There has been growing international interest in performing remote consultations in primary care, particularly amidst the current COVID-19 pandemic. Despite this, the evidence surrounding the safety of remote consultations is inconclusive. The appropriateness of antibiotic prescribing in remote consultations is an important aspect of patient safety that needs to be addressed. OBJECTIVE: This study aimed to summarize evidence on the impact of remote consultation in primary care with regard to antibiotic prescribing. METHODS: Searches were conducted in MEDLINE, Embase, HMIC, PsycINFO, and CINAHL for literature published since the databases' inception to February 2020. Peer-reviewed studies conducted in primary health care settings were included. All remote consultation types were considered, and studies were required to report any quantitative measure of antibiotic prescribing to be included in this systematic review. Studies were excluded if there were no comparison groups (face-to-face consultations). RESULTS: In total, 12 studies were identified. Of these, 4 studies reported higher antibiotic-prescribing rates, 5 studies reported lower antibiotic-prescribing rates, and 3 studies reported similar antibiotic-prescribing rates in remote consultations compared with face-to-face consultations. Guideline-concordant prescribing was not significantly different between remote and face-to-face consultations for patients with sinusitis, but conflicting results were found for patients with acute respiratory infections. Mixed evidence was found for follow-up visit rates after remote and face-to-face consultations. CONCLUSIONS: There is insufficient evidence to confidently conclude that remote consulting has a significant impact on antibiotic prescribing in primary care. However, studies indicating higher prescribing rates in remote consultations than in face-to-face consultations are a concern. Further, well-conducted studies are needed to inform safe and appropriate implementation of remote consulting to ensure that there is no unintended impact on antimicrobial resistance.

Effect of Li concentration-dependent material properties on diffusion induced stresses of a Sn anode.

Sn is one of the promising Li ion battery anode materials with high theoretical capacity and mechanical properties that allow for effective relaxation of Li diffusion-induced stresses. Sn is a low melting point metal with a low modulus and strength and has the ability to relax stresses via plasticity and creep deformations. In this study, concentration-dependent material properties are used in numerical simulations to model the Li diffusion-induced stress evolution in Sn micropillars. Simulation results using concentration-dependent material properties resulted in a completely different failure mode in comparison to that of concentration-independent simulation results. Tensile hoop stress needed for crack propagation was analyzed to be at the core for concentration-independent material properties, and switched to being at the surface for concentration-dependent simulation results. In addition, by incorporating these maximum tensile DIS results, the critical size for the failure of Sn micropillars was determined to be 5.3 µm at C/10 charging rate. This was then correlated with experimental observations, where fracture occurred in Sn micropillars with sizes larger than 6 µm, while 4.4 µm sized Sn micropillars survived the lithiation cycle.

Role of Graphene in Reducing Fatigue Damage in Cu/Gr Nanolayered Composite.

Nanoscale metal/graphene nanolayered composite is known to have ultrahigh strength as the graphene effectively blocks dislocations from penetrating through the metal/graphene interface. The same graphene interface, which has a strong sp2 bonding, can simultaneously serve as an effective interface for deflecting the fatigue cracks that are generated under cyclic bendings. In this study, Cu/Gr composite with repeat layer spacing of 100 nm was tested for bending fatigue at 1.6% and 3.1% strain up to 1,000,000 cycles that showed for the first time a 5-6 times enhancement in fatigue resistance compared to the conventional Cu thin film. Fatigue cracks that are generated within the Cu layer were stopped by the graphene interface, which are evidenced by cross-sectional scanning electron microscopy and transmission electron microscopy images. Molecular dynamics simulations for uniaxial tension of Cu/Gr showed limited accumulation of dislocations at the film/substrate interface, which makes the fatigue crack formation and propagation through thickness of the film difficult in this materials system.

Size-dependent hardness of five-fold twin structured Ag nanowires.

In this study, the size dependent hardness of silver nanowires with a five-fold twin structure was examined using nanoindentation. As the diameter of the nanowires is reduced, the five-fold twin boundaries restrict the dislocation motion, and therefore a size dependent plasticity is expected for these uniquely structured nanowires. The polyol reduction method with modifications was used to synthesize silver nanowires with different diameters in the range of 70 nm to 144 nm. The nanoindentation experiments were performed on silver nanowires deposited on a stiff MgO substrate, and the resulting h, P, and S data were analyzed using the analytical double contact model for nanowire indentation. The hardness of the nanowires determined using the double contact model showed an increase in the hardness with reduction in the diameter of the nanowires, as expected due to the presence of the twin boundaries. The hardness values determined using the analytical double contact model compared favorably to the hardness values calculated from the contact areas that were extracted from finite element method simulations of an elastic indentation into the silver nanowires on the MgO substrate.

5-(3',4'-Dihydroxyphenyl-γ-valerolactone), a Major Microbial Metabolite of Proanthocyanidin, Attenuates THP-1 Monocyte-Endothelial Adhesion.

Several metabolomics of polymeric flavan-3-ols have reported that proanthocyanidins are extensively metabolized by gut microbiota. 5-(3',4'-dihydroxyphenyl)-γ-valerolactone (DHPV) has been reported to be the major microbial metabolite of proanthocyanidins. We demonstrated that DHPV has stronger prevention effect on tumor necrosis factor (TNF)-α-stimulated adhesion of THP-1 human monocytic cells to human umbilical vein endothelial cells compared to its potential precursors such as procyanidin A1, A2, B1 and B2, (+)catechin, (-)epicatechin and its microbial metabolites such as 3-(3,4-dihydroxyphenyl)propionic acid and 2-(3,4-dihydroxyphenyl)acetic acid. Mechanism study showed that DHPV prevents THP-1 monocyte-endothelial cell adhesion by downregulating TNF-α-stimulated expressions of the two biomarkers of atherosclerosis such as vascular cell adhesion molecule-1 and monocyte chemotactic protein-1, activation of nuclear factor kappa B transcription and phosphorylation of I kappa-B kinase and IκBα. We suggested that DHPV has higher potentiality in prevention of atherosclerosis among the proanthocyanidin metabolites.

Highly reliable ag nanowire flexible transparent electrode with mechanically welded junctions.

Deformation behavior of the Ag nanowire flexible transparent electrode under bending strain is studied and results in a novel approach for highly reliable Ag nanowire network with mechanically welded junctions. Bending fatigue tests up to 500,000 cycles are used to evaluate the in situ resistance change while imposing fixed, uniform bending strain. In the initial stages of bending cycles, the thermally annealed Ag nanowire networks show a reduction in fractional resistance followed by a transient and steady-state increase at later stages of cycling. SEM analysis reveals that the initial reduction in resistance is caused by mechanical welding as a result of applied bending strain, and the increase in resistance at later stages of cycling is determined to be due to the failure at the thermally locked-in junctions. Based on the observations from this study, a new methodology for highly reliable Ag nanowire network is proposed: formation of Ag nanowire networks with no prior thermal annealing but localized junction formation through simple application of mechanical bending strain. The non-annealed, mechanically welded Ag nanowire network shows significantly enhanced cyclic reliability with essentially 0% increase in resistance due to effective formation of localized wire-to-wire contact.

Switchable tribology of ferroelectrics.

Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe-down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is widely applicable across various ferroelectrics with different chemical compositions and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm-cm) size. These findings demonstrate that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.

Limitations and high pressure behavior of MOF-5 for CO2 capture.

Porous network structures (e.g. metal-organic frameworks, MOFs) show considerable potential in dethroning monoethanol amine (MEA) from being the dominant scrubber for CO2 at the fossil-fuel-burning power generators. In contrast to their promise, structural stability and high-pressure behavior of MOFs are not well documented. We herein report moisture stability, mechanical properties and high-pressure compression on a model MOF structure, MOF-5. Our results show that MOF-5 can endure all tested pressures (0-225 bar) without losing its structural integrity, however, its moist air stability points at a 3.5 hour safety window (at 21.6 °C and 49% humidity) for an efficient CO2 capture. Isosteric heats of CO2 adsorption at high pressures show moderate interaction energy between CO2 molecules and the MOF-5 sorbent, which combined with the large sorption ability of MOF-5 in the studied pressure-temperature ranges show the viability of this sorbent for CO2 capturing purposes. The combination of the physicochemical methods we used suggests a generalized analytical standard for measuring viability in CO2 capture operations.

Carotid intima-media thickness in patients with carpal tunnel syndrome.

OBJECTIVES: We measured the carotid intima-media thickness, a surrogate marker of early atherosclerosis, in patients with carpal tunnel syndrome compared to a control group to evaluate the risk of atherosclerotic disease. METHODS: Between January 2011 and December 2011, female patients presenting to the outpatient neurology clinic for pain and paresthesia in the hands were screened for study enrollment. Patients 30 years or older were eligible for the study if they did not have a history of stroke or cardiovascular disease. RESULTS: During the study period, 111 patients (58 in the carpal tunnel syndrome group and 53 in the control group) were enrolled, with a mean age of 56 years (range, 32-79 years). There were no significant differences in baseline characteristics except maximum carotid intima-media thickness and body mass index. The maximum intima-media thickness was greater in the carpal tunnel syndrome group (mean ± SD, 1.05 ± 0.17 mm) than the control group (0.85 ± 0.22 mm; P < .0001). The body mass index was greater among the controls (P = .012). Simple linear regression analysis revealed that age (P < .0001), carpal tunnel syndrome (P < .0001), hypertension (P = .022), and systolic blood pressure (P = .034) were statistically significantly associated with increased intima-media thickness. Multiple linear regression analysis revealed that hypertension (P = .033), systolic blood pressure (P = .022), age (P < .0001), and carpal tunnel syndrome (P < .0001) were significantly associated with increased intima-media thickness, with carpal tunnel syndrome being the most influential factor (ß = 0.489). CONCLUSIONS: The maximum carotid intima-media thickness was significantly increased in patients with carpal tunnel syndrome compared to controls. Chronic inflammation beyond the traditional cardiovascular risk factors might be related to increased carotid intima-media thickness in patients with carpal tunnel syndrome.

Direct Probing of Lattice-Strain-Induced Oxygen Release in LiCoO2 and Li2 MnO3 without Electrochemical Cycling.

Since the recognition of a significant oxygen-redox contribution to enhancing the capacity of Li transition-metal oxide cathodes, the oxygen release and subsequent structural variations together with capacity fading are critical issues to achieve better electrochemical performance. As most previous reports dealt with the structural degradation of cathodes after electrochemical cycling, it is fairly difficult to clarify how substantial the effect of lattice strain on the oxygen release will be while exclusively ruling out any electrochemical influences. By utilizing nanoindentation and mechanical surface polishing of single-crystal LiCoO2 and Li2 MnO3 , the local variations of both the atomic structure and oxygen content are scrutinized. Atomic-column-resolved imaging reveals that local LiM (M = Co and Mn) disordering and further amorphization are induced by mechanical strain. Moreover, substantial oxygen deficiency in the regions with these structural changes is directly identified by spectroscopic analyses. Ab initio density functional theory calculations also demonstrate energetically favorable formation of oxygen vacancies under shear strain. Providing direct evidence of oxygen release as a consequence of lattice strain, the findings in this work suggest that efficient strain relaxation will be of great significance for longevity of the anion framework in layered oxide cathodes.

Multiscale Functional Metal Architectures by Antibody-Guided Metallization of Specific Protein Assemblies in Ex Vivo Multicellular Organisms.

Biological systems consist of hierarchical protein structures, each of which has unique 3D geometries optimized for specific functions. In the past decades, the growth of inorganic materials on specific proteins has attracted considerable attention. However, the use of specific proteins as templates has only been demonstrated in relatively simple organisms, such as viruses, limiting the range of structures that can be used as scaffolds. This study proposes a method for synthesizing metallic structures that resemble the 3D assemblies of specific proteins in mammalian cells and animal tissues. Using 1.4 nm nanogold-conjugated antibodies, specific proteins within cells and ex vivo tissues are labeled, and then the nanogold acts as nucleation sites for growth of metal particles. As proof of concept, various metal particles are grown using microtubules in cells as templates. The metal-containing cells are applied as catalysts and show catalytic stability in liquid-phase reactions due to the rigid support provided by the microtubules. Finally, this method is used to produce metal structures that replicate the specific protein assemblies of neurons in the mouse brain or the extracellular matrices in the mouse kidney and heart. This new biotemplating approach can facilitate the conversion of specific protein structures into metallic forms in ex vivo multicellular organisms.

Clinical Characteristics and Treatment Outcomes of Childhood Acute Promyelocytic Leukemia in Korea: A Nationwide Multicenter Retrospective Study by Korean Pediatric Oncology Study Group.

PURPOSE: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. MATERIALS AND METHODS: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. RESULTS: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). CONCLUSION: This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

Evaluation of early gastric cancer at multidetector CT with multiplanar reformation and virtual endoscopy.

Early gastric cancer (EGC) is defined as a carcinoma in which invasion is limited to the mucosa and submucosa, regardless of lymph node status and distant metastasis. Recent advances in multidetector computed tomography (CT) with multiplanar reformation (MPR) provide a powerful tool for identifying gastric wall invasion and the perigastric extent of gastric cancer. In addition, MPR images confer advantages in the assessment of both intra- and extraluminal processes of the gastric wall and the evaluation of more distant regions, such as the paraaortic lymph nodes and other abdominal organs. Virtual endoscopy performed after air distention of the stomach can aid in the evaluation of gastric endoluminal morphologic features and the extent of EGC. Moreover, virtual endoscopy helps in detecting subtle mucosal changes and differentiating them from submucosal lesions in the same way as conventional endoscopy. Virtual endoscopy can depict abnormal endoluminal lesions within a wider field of view than can conventional endoscopy, and there are no "blind spots" because retrospective image reformation is available, which provides useful information for preoperative mapping. Multidetector CT with MPR and virtual endoscopy is a powerful, noninvasive tool for the early detection and accurate preoperative staging of EGC.

Stretchable, porous, and conductive energy textiles.

Recently there is strong interest in lightweight, flexible, and wearable electronics to meet the technological demands of modern society. Integrated energy storage devices of this type are a key area that is still significantly underdeveloped. Here, we describe wearable power devices using everyday textiles as the platform. With an extremely simple "dipping and drying" process using single-walled carbon nanotube (SWNT) ink, we produced highly conductive textiles with conductivity of 125 S cm(-1) and sheet resistance less than 1 Omega/sq. Such conductive textiles show outstanding flexibility and stretchability and demonstrate strong adhesion between the SWNTs and the textiles of interest. Supercapacitors made from these conductive textiles show high areal capacitance, up to 0.48F/cm(2), and high specific energy. We demonstrate the loading of pseudocapacitor materials into these conductive textiles that leads to a 24-fold increase of the areal capacitance of the device. These highly conductive textiles can provide new design opportunities for wearable electronics and energy storage applications.