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The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response. Ivermectin was reported as one of the positive allosteric modulators, since the binding of Ivermectin to the channel enhances acetylcholine-evoked α7 currents. One research has suggested that tilting motions of the nicotinic acetylcholine receptor are responsible for channel opening and activation. To verify this hypothesis applies to α7 nicotinic acetylcholine receptor, we utilized a diffracted X-ray tracking method to monitor the stable twisting and tilting motion of nAChR α7 without a ligand, with acetylcholine, with Ivermectin, and with both of them. The results show that the α7 nicotinic acetylcholine receptor twists counterclockwise with the channel transiently opening, transitioning to a desensitized state in the presence of acetylcholine and clockwise without the channel opening in the presence of Ivermectin. We propose that the conformational transition of ACh-bound nAChR α7 may be due to the collective twisting of the five α7 subunits, resulting in the compression and movement, either downward or upward, of one or more subunits, thus manifesting tilting motions. These tilting motions possibly represent the transition from the resting state to channel opening and potentially to the desensitized state. [ABSTRACT FROM AUTHOR]

X-ray crystallography has revolutionized our understanding of biological macromolecules by elucidating their three-dimensional structures. However, the use of X-rays in this technique raises concerns about potential damage to the protein crystals, which results in a quality degradation of the diffraction data even at very low temperatures. Since such damage can occur on the micro- to millisecond timescale, a development in its real-time measurement has been expected. Here, we introduce diffracted X-ray blinking (DXB), which was originally proposed as a method to analyze the intensity fluctuations of diffraction of crystalline particles, to small-angle X-ray scattering (SAXS) of a lysozyme single-crystal. This novel technique, called the small-angle X-ray blinking (SAXB) method, analyzes the fluctuation in SAXS intensity reflecting the domain fluctuation in the protein crystal caused by the X-ray irradiation, which could be correlated with the X-ray-induced damage on the crystal. There was no change in the protein crystal's domain dynamics between the first and second X-ray exposures at 95K, each of which lasted 0.7 s. On the other hand, its dynamics at 295K increased remarkably. The SAXB method further showed a dramatic increase in domain fluctuations with an increasing dose of X-ray radiation, indicating the significance of this method. [ABSTRACT FROM AUTHOR]

Many psychrophilic microorganisms synthesize ice-binding proteins (IBPs) to survive the cold. The functions of IBPs are evaluated by the effect of the proteins on the nonequilibrium water freezing-point depression, which is called “thermal hysteresis (TH)”, and the inhibitory effect of the proteins on the growth of larger ice crystals, which is called “ice recrystallization inhibition (IRI)”. To obtain mechanical insight into the two activities, we developed a modified method of ice affinity purification and extracted two new IBP isoforms from Psychromyces glacialis, an Arctic glacier fungus. One isoform was found to be an approximately 25 kDa protein (PsgIBP_S), while the other is a 28 kDa larger protein (PsgIBP_L) that forms an intermolecular dimer. Their TH activities were less than 1 °C at millimolar concentrations, implying that both isoforms are moderately active but not hyperactive IBP species. It further appeared that both isoforms exhibit high IRI activity even at submicromolar concentrations. Furthermore, the isoforms can bind to the whole surface of a hemispherical single ice crystal, although such ice-binding was generally observed for hyperactive IBP species. These results suggest that the binding ability of IBPs to whole ice crystal surfaces is deficient for hyperactivity but is crucial for significant IRI activity. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA is detectable in nasopharyngeal specimens for up to 12–20 days regardless of the presence of chronic diseases in patients. We report a case of prolonged SARS-CoV-2 infection that lasted for more than eight weeks. The patient had persistent lymphopenia after receiving six cycles of bendamustine and rituximab (BR) therapy for follicular lymphoma; the last chemotherapy session was completed nine months before admission. The first nasopharyngeal specimen (NPS) for the SARS-CoV-2 polymerase chain reaction assay tested positive for the N501Y variant five weeks before admission. The patient's general and respiratory conditions gradually worsened; therefore, he was admitted to our hospital, and the same SARS-CoV-2 variant was subsequently identified on admission. Treatment for coronavirus disease was initiated, and the patient's condition improved; however, the NPS tested positive on day 15. The patient was discharged on day 28 and was instructed to isolate at home for a month. Hence, possible prolonged SARS-CoV-2 shedding should be considered in patients who receive BR therapy. [ABSTRACT FROM AUTHOR]

Purpose: To develop a noninvasive prognostic imaging biomarker related to hypoxia to predict SABR tumor control.Methods and Materials: A total of 145 subcutaneous syngeneic Dunning prostate R3327-AT1 rat tumors were focally irradiated once using cone beam computed tomography guidance on a small animal irradiator at 225 kV. Various doses in the range of 0 to 100 Gy were administered, while rats breathed air or oxygen, and tumor control was assessed up to 200 days. Oxygen-sensitive magnetic resonance imaging (MRI) (T1-weighted, ΔR1, ΔR2*) was applied to 79 of these tumors at 4.7 T to assess response to an oxygen gas breathing challenge on the day before irradiation as a probe of tumor hypoxia.Results: Increasing radiation dose in the range of 0 to 90 Gy enhanced tumor control of air-breathing rats with a TCD50 estimated at 59.6 ± 1.5 Gy. Control was significantly improved at some doses when rats breathed oxygen during irradiation (eg, 40 Gy; P < .05), and overall there was a modest left shift in the control curve: TCD50(oxygen) = 53.1 ± 3.1 Gy (P < .05 vs air). Oxygen-sensitive MRI showed variable response to oxygen gas breathing challenge; the magnitude of T1-weighted signal response (%ΔSI) allowed stratification of tumors in terms of local control at 40 Gy. Tumors showing %ΔSI >0.922 with O2-gas breathing challenge showed significantly better control at 40 Gy during irradiation while breathing oxygen (75% vs 0%, P < .01). In addition, increased radiation dose (50 Gy) substantially overcame resistance, with 50% control for poorly oxygenated tumors. Stratification of dose-response curves based on %ΔSI >0.922 revealed different survival curves, with TCD50 = 36.2 ± 3.2 Gy for tumors responsive to oxygen gas breathing challenge; this was significantly less than the 54.7 ± 2.4 Gy for unresponsive tumors (P < .005), irrespective of the gas inhaled during tumor irradiation.Conclusions: Oxygen-sensitive MRI allowed stratification of tumors in terms of local control at 40 Gy, indicating its use as a potential predictive imaging biomarker. Increasing dose to 50 Gy overcame radiation resistance attributable to hypoxia in 50% of tumors. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) inhibit ice growth by adsorbing onto specific ice planes. Microbial AFPs show diverse antifreeze activity and ice plane specificity, while sharing a common molecular scaffold. To probe the molecular mechanisms responsible for AFP activity, we here characterized the antifreeze activity and crystal structure of TisAFP7 from the snow mold fungus Typhula ishikariensis. TisAFP7 exhibited intermediate activity, with the ability to bind the basal plane, compared with a hyperactive isoform TisAFP8 and a moderately active isoform TisAFP6. Analysis of the TisAFP7 crystal structure revealed a bound-water network arranged in a zigzag pattern on the surface of the protein's ice-binding site (IBS). While the three AFP isoforms shared the water network pattern, the network on TisAFP7 IBS was not extensive, which was likely related to its intermediate activity. Analysis of the TisAFP7 crystal structure also revealed the presence of additional water molecules that form a ring-like network surrounding the hydrophobic side chain of a crucial IBS phenylalanine, which might be responsible for the increased adsorption of AFP molecule onto the basal plane. Based on these observations, we propose that the extended water network and hydrophobic hydration at IBS together determine the TisAFP activity. [ABSTRACT FROM AUTHOR]

Captions, which are used as a means of information support for deaf and hard-of-hearing students, are usually presented only in text form. Therefore, when mathematical equations and figures are frequently used in a classroom, the captions will show several demonstrative words such as "this equation" or "that figure." As there is a delay between the teacher's utterance and the display of the captions sometimes, it is difficult for users to grasp the target of these demonstrative words accurately. In this study, we prepared hybrid captions with mathematical equations and figures and verified their effectiveness via a comparison with conventional text-only captions. The results suggested that the hybrid captions were at least as effective as the conventional captions at helping the students understand the lesson contents. A subjective evaluation with a questionnaire survey also showed that the experimental participants found the hybrid captions to be acceptable without any discomfort. Furthermore, there was no difference in the number of eye movements of the participants during the experiment, suggesting that the physical load was similar for both types of captions. [ABSTRACT FROM AUTHOR]

Electro-oxidation is a promising technology to recover water from urine for space applications. The process generates oxidants such as reactive oxygen species and chlorine containing species that prevent microbial growth in the plumbing and decrease total organic carbon (TOC), chloride, and ammonia while waste heat generated from the electrochemical process facilitates evaporation of water to be recovered elsewhere. Resulting wastewater and generated gas constituents could be useful for recycling, further closing the environmental loop, and reducing trash/waste volume. In order to investigate the wastewater and generated gas constituents comprehensively, a full-scale urine processor for four crewmembers was built. Raw human urine (8.4 L) was circulated and processed by a flow-through oxidation cell (anode: boron-doped diamond on Niobium, cathode: Tungsten). The average water evaporation rate was 2.0 g/min. The 30-A current decreased TOC, chloride, and ammonia essentially to zero in the urine wastewater within 532, 622, and 373 A h, respectively. Total nitrogen (TN) was decreased from 5695 mg/L to 725 mg/L within 400 A h. Most of the remaining nitrogen was nitrate. Approximately 2.6 g of chlorine/chlorine dioxide, 0.85 g of ozone, 46.5 g of carbon dioxide, 15 g of hydrogen, and 0.1 g of ammonia gases were generated from 8.4 L of urine. The test demonstrated water evaporation for water recovery and identified useful gases to be recycled in an environmental control and life support system for space applications. • Total organic carbon, Cl⁻, and NH₃ were decreased in urine by electro-oxidation. • The heat from oxidation process evaporated water for recovery in space application. • The oxidation process lowered the pH of the urine wastewater without pretreatment. • CO₂, Cl₂, O₃, H₂, and NH₃ gases were generated, to be recycled or scrubbed. [ABSTRACT FROM AUTHOR]

In recent years, several studies have been performed on methods of investigating the periphery of power lines using remote sensing. Among the survey methods using unmanned aerial vehicles (UAVs), those methods are being studied wherein the environment around power lines is photographed by a UAV, and separation measurements are performed by reconstructing the three‐dimensional (3D) point cloud between power lines and the vegetation. Such methods currently rely on reconstructing the power line, making it necessary to acquire images from a position close to the power line. However, by using information available from the power company on the position and structure of pylons and the sag of power lines, it is possible to calculate the position of the power line without 3D reconstruction. In this study, time series management of vegetation around power lines was enabled using the data obtained by UAVs at different times and information on the transmission equipment. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Mycoplasma pneumonia with mild CNS involvements should be considered of MERS, even in adult. From the case series, splenial single lesions by MRI and prodromal fever with varied neurological manifestations recovered completely by antibiotics were seen. [ABSTRACT FROM AUTHOR]

Various microbes, including fungi and bacteria, that live in cold environments produce ice‐binding proteins (IBPs) that protect them from freezing. Ascomycota and Basidiomycota are two major phyla of fungi, and Antarctomyces psychrotrophicus is currently designated as the sole ascomycete that produces IBP (AnpIBP). However, its complete amino acid sequence, ice‐binding property, and evolutionary history have not yet been clarified. Here, we determined the peptide sequences of three new AnpIBP isoforms by total cDNA analysis and compared them with those of other microbial IBPs. The AnpIBP isoforms and ascomycete‐putative IBPs were found to be phylogenetically close to the bacterial ones but far from the basidiomycete ones, which is supported by the higher sequence identities to bacterial IBPs than basidiomycete IBPs, although ascomycetes are phylogenetically distant from bacteria. In addition, two of the isoforms of AnpIBP share low sequence identity and are not close in the phylogenetic tree. It is hence presumable that these two AnpIBP isoforms were independently acquired from different bacteria through horizontal gene transfer (HGT), which implies that ascomycetes and bacteria frequently exchange their IBP genes. The non‐colligative freezing‐point depression ability of AnpIBP was not very high, whereas it exhibited significant abilities of ice recrystallization inhibition, ice shaping, and cryo‐protection against freeze–thaw cycles even at submicromolar concentrations. These results suggest that HGT is crucial for the cold‐adaptive evolution of ascomycetes, and their IBPs offer freeze resistance to organisms to enable them to inhabit the icy environments of Antarctica. Databases: Nucleotide sequence data are available in the DDBJ database under the accession numbers LC378707, LC378707, LC378707 for AnpIBP1a, AnpIBP1b, AnpIBP2, respectively. Ice‐binding proteins (IBPs) are cryoprotective polypeptides produced by various cold‐adapted microbes, such as bacteria and fungi. We identified two IBP genes from an Antarctic fungus, Antarctomyces psychrotrophicus. Phylogenetic analysis revealed that these two genes were possibly acquired from two different bacteria through horizontal gene transfer, which suggests that IBP genes are frequently exchanged between different microbes in Antarctica. [ABSTRACT FROM AUTHOR]

A resin bead Mitsubishi DIAION™ CR20 was identified and characterized as a first commercial off-the shelf regenerable carbon dioxide (CO 2 ) sorbent candidate for space life support system applications at room temperature. The CO 2 adsorption rates and capacities of CR20 at varying CO 2 partial pressures were obtained. The data were used to numerically simulate CO 2 adsorption by a swingbed, a pair of two sorbent beds that alternately adsorb and desorb CO 2 in a space suit portable life support system (PLSS). The result demonstrated that a reasonable volume of CR20 would be able to continuously adsorb CO 2 with bed-swing interval of 4 min at 300-W metabolic rate, and that commercial off-the shelf CR20 would have similar performance of CO 2 adsorption to the proprietary swingbed sorbent SA9T for PLSS applications. [ABSTRACT FROM AUTHOR]

Multi-modality image-guided radiotherapy is the standard of care in contemporary cancer management; however, it is not common in preclinical settings due to both hardware and software limitations. Soft tissue lesions, such as orthotopic prostate tumors, are difficult to identify using cone beam computed tomography (CBCT) imaging alone. In this study, we characterized a research magnetic resonance (MR) scanner for preclinical studies and created a protocol for combined MR-CBCT image-guided small animal radiotherapy. Two in-house dual-modality, MR and CBCT compatible, phantoms were designed and manufactured using 3D printing technology. The phantoms were used for quality assurance tests and to facilitate end-to-end testing for combined preclinical MR and CBCT based treatment planning. MR and CBCT images of the phantoms were acquired utilizing a Varian 4.7 T scanner and XRad-225Cx irradiator, respectively. The geometry distortion was assessed by comparing MR images to phantom blueprints and CBCT. The corrected MR scans were co-registered with CBCT and subsequently used for treatment planning. The fidelity of 3D printed phantoms compared to the blueprint design yielded favorable agreement as verified with the CBCT measurements. The geometric distortion, which varied between -5% and 11% throughout the scanning volume, was substantially reduced to within 0.4% after correction. The distortion free MR images were co-registered with the corresponding CBCT images and imported into a commercial treatment planning software SmART Plan. The planning target volume (PTV) was on average 19% smaller when contoured on the corrected MR-CBCT images relative to raw images without distortion correction. An MR-CBCT based preclinical workflow was successfully designed and implemented for small animal radiotherapy. Combined MR-CBCT image-guided radiotherapy for preclinical research potentially delivers enhanced relevance to human radiotherapy for various disease sites. This novel protocol is wide-ranging and not limited to the orthotopic prostate tumor study presented in the study. [ABSTRACT FROM AUTHOR]

A definition of chaos in the sense of Li-Yorke is given for an action of a group on a uniform space, and it is shown that if a continuous action of an Abelian group G on a second countable Baire Hausdorff uniform space X without isolated points is chaotic in the sense of Devaney, then it is also chaotic in the sense of Li-Yorke. [ABSTRACT FROM AUTHOR]

Key points Pulmonary perfusion measurement using magnetic resonance imaging combined with deformable image registration enabled us to quantify the change in the spatial distribution of pulmonary perfusion at different lung volumes., The current study elucidated the effects of tidal volume lung inflation [functional residual capacity (FRC) + 500 ml and FRC + 1 litre] on the change in pulmonary perfusion distribution., Changes in hydrostatic pressure distribution as well as transmural pressure distribution due to the change in lung height with tidal volume inflation are probably bigger contributors to the redistribution of pulmonary perfusion than the changes in pulmonary vasculature resistance caused by lung tissue stretch., Abstract Tidal volume lung inflation results in structural changes in the pulmonary circulation, potentially affecting pulmonary perfusion. We hypothesized that perfusion is recruited to regions receiving the greatest deformation from a tidal breath, thus ensuring ventilation-perfusion matching. Density-normalized perfusion (DNP) magnetic resonance imaging data were obtained in healthy subjects ( n = 7) in the right lung at functional residual capacity (FRC), FRC+500 ml, and FRC+1.0 l. Using deformable image registration, the displacement of a sagittal lung slice acquired at FRC to the larger volumes was calculated. Registered DNP images were normalized by the mean to estimate perfusion redistribution (nDNP). Data were evaluated across gravitational regions (dependent, middle, non-dependent) and by lobes (upper, RUL; middle, RML; lower, RLL). Lung inflation did not alter mean DNP within the slice ( P = 0.10). The greatest expansion was seen in the dependent region ( P < 0.0001: dependent vs non-dependent, P < 0.0001: dependent vs middle) and RLL ( P = 0.0015: RLL vs RUL, P < 0.0001: RLL vs RML). Neither nDNP recruitment to RLL [+500 ml = −0.047(0.145), +1 litre = 0.018(0.096)] nor to dependent lung [+500 ml = −0.058(0.126), +1 litre = −0.023(0.106)] were found. Instead, redistribution was seen in decreased nDNP in the non-dependent [+500 ml = −0.075(0.152), +1 litre = −0.137(0.167)) and increased nDNP in the gravitational middle lung [+500 ml = 0.098(0.058), +1 litre = 0.093(0.081)] ( P = 0.01). However, there was no significant lobar redistribution ( P < 0.89). Contrary to our hypothesis, based on the comparison between gravitational and lobar perfusion data, perfusion was not redistributed to the regions of the most inflation. This suggests that either changes in hydrostatic pressure or transmural pressure distribution in the gravitational direction are implicated in the redistribution of perfusion away from the non-dependent lung. [ABSTRACT FROM AUTHOR]

Purpose: Sparse-sampling and reconstruction techniques represent an attractive strategy to achieve faster image acquisition speeds, while maintaining adequate spatial resolution and signal-to-noise ratio in rapid magnetic resonance imaging (MRI). The authors investigate the use of one such sequence, broad-use linear acquisition speed-up technique (k-t BLAST) in monitoring tumor motion for thoracic and abdominal radiotherapy and examine the potential trade-off between increased sparsification (to increase imaging speed) and the potential loss of "true" information due to greater reliance on a priori information. Methods: Lung tumor motion trajectories in the superior–inferior direction, previously recorded from ten lung cancer patients, were replayed using a motion phantom module driven by an MRI-compatible motion platform. Eppendorf test tubes filled with water which serve as fiducial markers were placed in the phantom. The modeled rigid and deformable motions were collected in a coronal image slice using balanced fast field echo in conjunction with k-t BLAST. Root mean square (RMS) error was used as a metric of spatial accuracy as measured trajectories were compared to input data. The loss of spatial information was characterized for progressively increasing acceleration factor from 1 to 16; the resultant sampling frequency was increased approximately from 2.5 to 19 Hz when the principal direction of the motion was set along frequency encoding direction. In addition to the phantom study, respiration-induced tumor motions were captured from two patients (kidney tumor and lung tumor) at 13 Hz over 49 s to demonstrate the impact of high speed motion monitoring over multiple breathing cycles. For each subject, the authors compared the tumor centroid trajectory as well as the deformable motion during free breathing. Results: In the rigid and deformable phantom studies, the RMS error of target tracking at the acquisition speed of 19 Hz was approximately 0.3–0.4 mm, which was smaller than the reconstructed pixel resolution of 0.67 mm. In the patient study, the dynamic 2D MRI enabled the monitoring of cycle-to-cycle respiratory variability present in the tumor position. It was seen that the range of centroid motion as well as the area covered due to target motion during each individual respiratory cycle was underestimated compared to the entire motion range observed over multiple breathing cycles. Conclusions: The authors' initial results demonstrate that sparse-sampling- and reconstructionbased dynamic MRI can be used to achieve adequate image acquisition speeds without significant information loss for the task of radiotherapy guidance. Such monitoring can yield spatial and temporal information superior to conventional offline and online motion capture methods used in thoracic and abdominal radiotherapy. [ABSTRACT FROM AUTHOR]

Abstract: Orthostatic intolerance (OI) is a significant challenge for astronauts after long-duration spaceflight. Depending on flight duration, 20–80% of astronauts suffer from post-flight OI, which is associated with reduced vascular resistance. This paper introduces a novel algorithm for continuously monitoring changes in total peripheral resistance (TPR) by processing the peripheral arterial blood pressure (ABP). To validate, we applied our novel mathematical algorithm to the pre-flight ABP data previously recorded from twelve astronauts ten days before launch. The TPR changes were calculated by our algorithm and compared with the TPR value estimated using cardiac output/heart rate before and after phenylephrine administration. The astronauts in the post-flight presyncopal group had lower pre-flight TPR changes (1.66 times) than those in the non-presyncopal group (2.15 times). The trend in TPR changes calculated with our algorithm agreed with the TPR trend calculated using measured cardiac output in the previous study. Further data collection and algorithm refinement are needed for pre-flight detection of OI and monitoring of continuous TPR by analysis of peripheral arterial blood pressure. [Copyright &y& Elsevier]

There is a gravitational influence on pulmonary perfusion, including in the most dependent lung, where perfusion is reduced, termed Zone 4. Studies using xenon-133 show Zone 4 behaviour, present in the dependent 4 cm at total lung capacity (TLC), affects the dependent 11 cm at functional residual capacity (FRC) and almost all the lung at residual volume (RV). These differences were ascribed to increased resistance in extra-alveolar vessels at low lung volumes although other mechanisms have been proposed. To further evaluate the behaviour of perfusion in dependent lung using a technique that directly measures pulmonary perfusion and corrects for tissue distribution by measuring regional proton density, seven healthy subjects (age = 38 ± 6 years, FEV= 104 ± 7% predicted) underwent magnetic resonance imaging in supine posture. Data were acquired in the right lung during breath-holds at RV, FRC and TLC. Arterial spin labelling quantified regional pulmonary perfusion, which was normalized for regional proton density measured using a fast low-angle shot technique. The height of the onset of Zone 4 behaviour was not different between lung volumes ( P= 0.23). There were no significant differences in perfusion (expressed as ml min g) between lung volumes in the gravitationally intermediate (RV = 8.9 ± 3.1, FRC = 8.1 ± 2.9, TLC = 7.4 ± 3.6; P= 0.26) and dependent lung (RV = 6.6 ± 2.4, FRC = 6.1 ± 2.1, TLC = 6.4 ± 2.6; P= 0.51). However, at TLC perfusion was significantly lower in non-dependent lung than at FRC or RV (3.6 ± 3.3, 7.7 ± 1.5, 7.9 ± 2.0, respectively; P < 0.001). These data suggest that the mechanism of the reduction in perfusion in dependent lung is unlikely to be a result of lung volume related increases in resistance in extra-alveolar vessels. In supine posture, the gravitational influence on perfusion is remarkably similar over most of the lung, irrespective of lung volume. The lung is subject to multiple influences that affect its function. In particular the effect of gravity has attracted considerable interest, especially as it relates to the distribution of blood flow. In the most gravitationally dependent part of the lung, blood flow is reduced, and this region is known as Zone 4. Zone 4 has been suggested to result from increased resistance in some of the blood vessels, and this effect is thought to be the smallest when the lung is at a high volume as the elastic structures of the lung hold the vessels open minimizing resistance. Using novel magnetic resonance imaging techniques to measure blood flow, this study shows that the distribution of blood flow in the dependent lung is unchanged when the lung volume is changed and suggests that the intrinsic structure of the vessels is a more likely explanation for this behaviour. [ABSTRACT FROM AUTHOR]

Abstract: For long term missions on the moon and Mars, regenerative life support systems emerge as a promising key technology for sustaining successful explorations with reduced re-supply logistics and cost. The purpose of this study was to create a simple model of a regenerative life support system which allows preliminary investigation of system responses. A simplified regenerative life support system was made with MATLAB Simulink. Mass flows in the system were simplified to carbon, water, oxygen and carbon dioxide. The subsystems included crew members, animals, a plant module, and a waste processor, which exchanged mass into and out of mass reservoirs. Preliminary numerical simulations were carried out to observe system responses. The simplified life support system model allowed preliminary investigation of the system response to perturbations such as increased or decreased number of crew members. The model is simple and flexible enough to add new components, and also possible to numerically predict non-linear subsystem functions and responses. Future work includes practical issues such as energy efficiency, air leakage, nutrition, and plant growth modeling. The model functions as an effective teaching tool about how a regenerative advanced life support system works. [Copyright &y& Elsevier]

Abstract: Let f be a continuous map from a compact metric space X to itself. The map f is called to be P-chaotic if it has the pseudo-orbit-tracing property and the closure of the set of all periodic points for f is equal to X. We show that every P-chaotic map from a continuum to itself is chaotic in the sense of Devaney and exhibits distributional chaos of type 1 with positive topological entropy. [Copyright &y& Elsevier]

In the second paragraph of Definition 2.4, we defined elements x and y to be asymptotic if for any U ∈ 𝓤 and any {Gi | i ∈ ℕ} ∈ 𝓖, there exists k ∈ ℕ such that (gx,gy) ∈ U for each g ∈ G∖Gk. However, this definition is incorrect, because it holds that x and y are asymptotic if and only if x = y. [ABSTRACT FROM AUTHOR]

Beetle hyperactive antifreeze protein (AFP) has a unique ability to maintain a supercooling state of its body fluids, however, less is known about its origination. Here, we found that a popular stag beetle Dorcus hopei binodulosus (Dhb) synthesizes at least 6 isoforms of hyperactive AFP (DhbAFP). Cold-acclimated Dhb larvae tolerated −5 °C chilled storage for 24 h and fully recovered after warming, suggesting that DhbAFP facilitates overwintering of this beetle. A DhbAFP isoform (~10 kDa) appeared to consist of 6−8 tandem repeats of a 12-residue consensus sequence (TCTxSxNCxxAx), which exhibited 3 °C of high freezing point depression and the ability of binding to an entire surface of a single ice crystal. Significantly, these properties as well as DNA sequences including the untranslated region, signal peptide region, and an AFP-encoding region of Dhb are highly similar to those identified for a known hyperactive AFP (TmAFP) from the beetle Tenebrio molitor (Tm). Progenitor of Dhb and Tm was branched off approximately 300 million years ago, so no known evolution mechanism hardly explains the retainment of the DNA sequence for such a lo-ng divergence period. Existence of unrevealed gene transfer mechanism will be hypothesized between these two phylogenetically distant beetles to acquire this type of hyperactive AFP. [ABSTRACT FROM AUTHOR]

Many microbes that survive in cold environments are known to secrete ice-binding proteins (IBPs). The structure–function relationship of these proteins remains unclear. A microbial IBP denoted AnpIBP was recently isolated from a cold-adapted fungus, Antarctomyces psychrotrophicus. The present study identified an orbital illumination (prism ring) on a globular single ice crystal when soaked in a solution of fluorescent AnpIBP, suggesting that AnpIBP binds to specific water molecules located in the ice prism planes. In order to examine this unique ice-binding mechanism, we carried out X-ray structural analysis and mutational experiments. It appeared that AnpIBP is made of 6-ladder β-helices with a triangular cross section that accompanies an "ice-like" water network on the ice-binding site. The network, however, does not exist in a defective mutant. AnpIBP has a row of four unique hollows on the IBS, where the distance between the hollows (14.7 Å) is complementary to the oxygen atom spacing of the prism ring. These results suggest the structure of AnpIBP is fine-tuned to merge with the ice–water interface of an ice crystal through its polygonal water network and is then bound to a specific set of water molecules constructing the prism ring to effectively halt the growth of ice. [ABSTRACT FROM AUTHOR]

Hydration is crucial for a function and a ligand recognition of a protein. The hydration shell constructed on an antifreeze protein (AFP) contains many organized waters, through which AFP is thought to bind to specific ice crystal planes. For a Ca2+-dependent species of AFP, however, it has not been clarified how 1 mol of Ca2+-binding is related with the hydration and the ice-binding ability. Here we determined the X-ray crystal structure of a Ca2+-dependent AFP (jsAFP) from Japanese smelt, Hypomesus nipponensis, in both Ca2+-bound and -free states. Their overall structures were closely similar (Root mean square deviation (RMSD) of Cα = 0.31 Å), while they exhibited a significant difference around their Ca2+-binding site. Firstly, the side-chains of four of the five Ca2+-binding residues (Q92, D94 E99, D113, and D114) were oriented to be suitable for ice binding only in the Ca2+-bound state. Second, a Ca2+-binding loop consisting of a segment D94–E99 becomes less flexible by the Ca2+-binding. Third, the Ca2+-binding induces a generation of ice-like clathrate waters around the Ca2+-binding site, which show a perfect position-match to the waters constructing the first prism plane of a single ice crystal. These results suggest that generation of ice-like clathrate waters induced by Ca2+-binding enables the ice-binding of this protein. [ABSTRACT FROM AUTHOR]

Ice recrystallization is a phenomenon observed as the increase in ice crystal size within an already frozen material. Antifreeze proteins (AFPs), a class of proteins capable of arresting ice crystal growth, are known to inhibit this phenomenon even at sub milli-molar concentrations. A tremendous range in the possible applications of AFPs is hence expected in both medical and industrial fields, while a key determinant of the ice recrystallization inhibition (IRI) is hardly understood. Here, IRI efficiency and ice plane affinity were examined for the wild-type AFPI-III, a defective AFPIII isoform, and a fungal AFP isoform. To simplify the IRI analysis using the formal representation of Ostwald-ripening (r3 = r03 + kt), we monitored specific ice grains exhibiting only uniform growth, for which maximum Feret diameter was measured. The cube of an ice grain's radius (r3) increased proportionately with time (t), and its slope gave the recrystallization rate (k). There was a significant difference in the IRI efficiency between the samples, and the fungal AFP possessing the activity with the smallest amount (0.27 μM) exhibited an affinity to multiple ice planes. These results suggest that the IRI efficiency is maximized when AFPs bind to a whole set of ice planes. [ABSTRACT FROM AUTHOR]

Introduction: We previously introduced the inverse solution guidance algorithm (ISGA) methodology using a Single Equivalent Moving Dipole model of cardiac electrical activity to localize both the exit site of a re‐entrant circuit and the tip of a radiofrequency (RF) ablation catheter. The purpose of this study was to investigate the use of ISGA for ablation catheter guidance in an animal model. Methods: Ventricular tachycardia (VT) was simulated by rapid ventricular pacing at a target site in eleven Yorkshire swine. The ablation target was established using three different techniques: a pacing lead placed into the ventricular wall at the mid‐myocardial level (Type‐1), an intracardiac mapping catheter (Type‐2), and an RF ablation catheter placed at a random position on the endocardial surface (Type‐3). In each experiment, one operator placed the catheter/pacing lead at the target location, while another used the ISGA system to manipulate the RF ablation catheter starting from a random ventricular location to locate the target. Results: The average localization error of the RF ablation catheter tip was 0.31 ± 0.08 cm. After analyzing approximately 35 cardiac cycles of simulated VT, the ISGA system's accuracy in locating the target was 0.4 cm after four catheter movements in the Type‐1 experiment, 0.48 cm after six movements in the Type‐2 experiment, and 0.67 cm after seven movements in the Type‐3 experiment. Conclusion: We demonstrated the feasibility of using the ISGA method to guide an ablation catheter to the origin of a VT focus by analyzing a few beats of body surface potentials without electro‐anatomic mapping. [ABSTRACT FROM AUTHOR]

The photoinduced crawling motion of crystals is a continuous motion that azobenzene molecular crystals exhibit under light irradiation. Such motion enables object manipulation at the microscale with a simple setup of fixed LED light sources. Transportation of nano-/micromaterials using photoinduced crawling motion has recently been reported. However, the details of the motion mechanism have not been revealed so far. Herein, we report visualization of the dynamics of fine particles in 4-(methylamino)azobenzene (4-MAAB) crystals under light irradiation via diffracted X-ray tracking (DXT). Continuously repeated melting and recrystallization of 4-MAAB crystals under light irradiation results in the flow of liquid 4-MAAB. Zinc oxide (ZnO) particles were introduced inside the 4-MAAB crystals to detect diffracted X-rays. The ZnO particles rotate with the flow of liquid 4-MAAB. By using white X-rays with a wide energy width, the rotation of each zinc oxide nanoparticle was detected as the movement of a bright spot in the X-ray diffraction pattern. It was clearly shown that the ZnO particles rotated increasingly as the irradiation light intensity increased. Furthermore, we also found anisotropy in the rotational direction of ZnO particles that occurred during the crawling motion of 4-MAAB crystals. It has become clear that the flow perpendicular to the supporting film of 4-MAAB crystals is enhanced inside the crystal during the crawling motion. DXT provides a unique means to elucidate the mechanism of photoinduced crawling motion of crystals. [ABSTRACT FROM AUTHOR]

Antifreeze proteins (AFPs) are multifunctional polypeptides that adsorb onto ice crystals to inhibit their growth and onto cells to protect them from nonfreezing hypothermic damage. However, the mechanism by which AFP exerts its hypothermic cell protective (HCP) function remains uncertain. Here, we assessed the HCP function of three types of fish-derived AFPs (type I, II, and III AFPs) against human T-lymphoblastic lymphoma by measuring the survival rate (%) of the cells after preservation at 4 °C for 24 h. All AFPs improved the survival rate in a concentration-dependent manner, although the HCP efficiency was inferior for type III AFP compared to other AFPs. In addition, after point mutations were introduced into the ice-binding site (IBS) of a type III AFP, HCP activity was dramatically increased, suggesting that the IBS of AFP is involved in cell adsorption. Significantly, high HCP activity was observed for a mutant that exhibited poorer antifreeze activity, indicating that AFP exerts HCP- and ice-binding functions through a different mechanism. We next incubated the cells in an AFP-containing solution, replaced it with pure EC solution, and then preserved the cells, showing that no significant reduction in the cell survival rate occurred for type I and II AFPs even after replacement. Thus, these AFPs irreversibly bind to the cells at 4 °C, and only tightly adsorbed AFP molecules contribute towards the cell-protection function. • Antifreeze proteins bind to ice crystals and cells to perform different functions. • The correlation between antifreeze and cell protective functions of AFP was studied. • AFPs protect the white blood cell line in a concentration-dependent manner at 4 °C. • Irreversible binding at the ice-binding site of AFP leads to its protective function. [ABSTRACT FROM AUTHOR]

Dynamic behavior in soft matter physics, biology, and nanoscience frequently occurs on submicrosecond timescales. Diffracted x-ray blinking (DXB) is a unique method that can provide a broad range of spatial scale information and is becoming an attractive tool for use at high repetition rate x-ray facilities. In this study, we performed DXB experiments with 890 ns time resolution at the European X-ray Free-Electron Laser Facility to obtain dynamic information about rubber samples that are typically used in automobile tires. Time-resolved scattering was simultaneously recorded for two samples that mainly consisted of carbon black (CB) and polybutadiene (PB). These samples contained either graphitized or non-graphitized CB and displayed significantly different dynamics. A clear interaction between CB and PB was observed, indicating that the mobility of PB was changed by the introduction of CB. Restricted polymer motion was observed in the q-range of 0.78–1.58 Å−1 regions. Our results suggest that the particle network can be flexibly controlled without impairing the mechanical strength of the rubber. [ABSTRACT FROM AUTHOR]

A cryoprotectant known as ice-binding protein (IBP) is thought to facilitate the cold survival of plants, insects, and fungi. Here, we prepared a genetically modified Caenorhabditis elegans strain to synthesize fish-derived IBPs in its body wall muscles and examined whether the antifreeze activity modification of this IBP by point mutation affects the cold tolerance of this worm. We chose a 65-residue IBP identified from notched-fin eelpout, for which the replacement of the 20th alanine residue (A20) modifies its antifreeze activity. These mutant proteins are denoted A20L, A20G, A20T, A20V, and A20I along with the wild-type (WT) protein. We evaluated the survival rate (%) of the transgenic C. elegans that synthesized each IBP mutant following 24 h of preservation at −5, +2, and +5 °C. Significantly, a dramatic improvement in the survival rate was detected for the worms synthesizing the activity-enhanced mutants (A20T and A20I), especially at +2 °C. In contrast, the rate was not improved by the expression of the defective mutants (A20L, A20G, WT and A20V). The survival rate (%) probably correlates with the antifreeze activity of the IBP. These data suggest that IBP protects the cell membrane by employing its ice-binding mechanism, which ultimately improves the cold tolerance of an IBP-containing animal. • Ice-binding protein (IBP) improves the cold tolerance of transgenic C. elegans. • IBP activity improvement affects the survival rate of C. elegans. • Cell protection and ice binding by IBPs may originate from the same mechanism. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study?How does the interaction between posture and gravity affect the stresses on the lung, particularly in highly inflated gravitationally non‐dependent regions, which are potentially vulnerable to increased mechanical stress and injury?What is the main finding and its importance?Changes in stress attributable to gravity are not well characterized between postures. Using a new metric of gravitational stress, we show that regions of the lung near maximal inflation have the greatest gravitational stresses while supine, but not while prone. In simulations of increased lung weight consistent with severe pulmonary oedema, the prone lung has lower gravitational stress in vulnerable, non‐dependent regions, potentially protecting them from overinflation and injury. Prone posture changes the gravitational vector, and potentially the stress induced by tissue deformation, because a larger lung volume is gravitationally dependent when supine, but non‐dependent when prone. To evaluate this, 10 normal subjects (six male and four female; age, means ± SD = 27 ± 6 years; height, 171 ± 9 cm; weight, 69 ± 13 kg; forced expiratory volume in the first second/forced expiratory volume as a percentage of predicted, 93 ± 6%) were imaged at functional residual capacity, supine and prone, using magnetic resonance imaging, to quantify regional lung density. We defined regional gravitational stress as the cumulative weight, per unit area, of the column of lung tissue below each point. Gravitational stress was compared between regions of differing inflation to evaluate differences between highly stretched, and thus potentially vulnerable, regions and less stretched lung. Using reference density values for normal lungs at total lung capacity (0.10 ± 0.03 g/ml), regions were classified as highly inflated (density < 0.13 g/ml, i.e., close to total lung capacity), intermediate (0.13 ≤ density < 0.16 g/ml) or normally inflated (density ≥ 0.16 g/ml). Gravitational stress differed between inflation categories while supine (−1.6 ± 0.3 cmH2O highly inflated; −1.4 ± 0.3 cmH2O intermediate; −1.1 ± 0.1 cmH2O normally inflated; P = 0.05) but not while prone (−1.4 ± 0.2 cmH2O highly inflated; −1.3 ± 0.2 cmH2O intermediate; −1.3 ± 0.1 cmH2O normally inflated; P = 0.39), and increased more with height from dependent lung while supine (−0.24 ± 0.02 cmH2O/cm supine; −0.18 ± 0.04 cmH2O/cm prone; P = 0.05). In simulated severe pulmonary oedema, the gradient in gravitational stress increased in both postures (all P < 0.0001), was greater in the supine posture than when prone (−0.57 ± 0.21 cmH2O/cm supine; −0.34 ± 0.16 cmH2O/cm prone; P = 0.0004) and was similar to the gradient calculated from supine computed tomography images in a patient with acute respiratory distress syndrome (−0.51 cmH2O/cm). The non‐dependent lung has greater gravitational stress while supine and might be protected while prone, particularly in the presence of oedema. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline perovskite KNbO3 is prepared by a peroxo-precursor decomposition method at moderate temperatures of 650–900°C. Peroxo-heteropoly-niobic acid is prepared by direct reaction between NbC powder and H2O2 aq, and mixing the peroxo-heteropoly-niobic acid with KOH aq yields an amorphous precursor salt. Perovskite KNbO3 is obtained by heating the precursor in air for 1h at 650–900°C. The X-ray diffraction patterns were well fitted with the space group Pm3m in the Rietveld analysis. The X-ray diffraction peak profiles and field emission scanning electron microscope images indicate the crystallite size is in the range of 25–35nm. [ABSTRACT FROM AUTHOR]

This article focuses on a study related to cervical spinal cord injury in sumo wrestling. Sumo has long been a traditional sport in Japan. But the first World Sumo Championship was held only as recently as 1992, when the International Sumo Federation was established. Since then, the World Sumo Championships have been held in Japan, Germany, and Brazil. In the present case a 19-year-old collegiate sumo wrestler, 166 cm tall and weighing 78 kg, had been practicing sumo for 10 years. During an intercollegiate sumo championship on October 31, 1999, he competed with an opponent whose weight was 120 kg.

Purpose: To accurately and efficiently reconstruct a continuous surface from noisy point clouds captured by a surface photogrammetry system (VisionRT). Methods: The authors have developed a level-set based surface reconstruction method on point clouds captured by a surface photogrammetry system (VisionRT). The proposed method reconstructs an implicit and continuous representation of the underlying patient surface by optimizing a regularized fitting energy, offering extra robustness to noise and missing measurements. By contrast to explicit/discrete meshing-type schemes, their continuous representation is particularly advantageous for subsequent surface registration and motion tracking by eliminating the need for maintaining explicit point correspondences as in discrete models. The authors solve the proposed method with an efficient narrowband evolving scheme. The authors evaluated the proposed method on both phantom and human subject data with two sets of complementary experiments. In the first set of experiment, the authors generated a series of surfaces each with different black patches placed on one chest phantom. The resulting VisionRT measurements from the patched area had different degree of noise and missing levels, since VisionRT has difficulties in detecting dark surfaces. The authors applied the proposed method to point clouds acquired under these different configurations, and quantitatively evaluated reconstructed surfaces by comparing against a high-quality reference surface with respect to root mean squared error (RMSE). In the second set of experiment, the authors applied their method to 100 clinical point clouds acquired from one human subject. In the absence of ground-truth, the authors qualitatively validated reconstructed surfaces by comparing the local geometry, specifically mean curvature distributions, against that of the surface extracted from a high-quality CT obtained from the same patient. Results: On phantom point clouds, their method achieved submillimeter reconstruction RMSE under different configurations, demonstrating quantitatively the faith of the proposed method in preserving local structural properties of the underlying surface in the presence of noise and missing measurements, and its robustness toward variations of such characteristics. On point clouds from the human subject, the proposed method successfully reconstructed all patient surfaces, filling regions where raw point coordinate readings were missing. Within two comparable regions of interest in the chest area, similar mean curvature distributions were acquired from both their reconstructed surface and CT surface, with mean and standard deviation of (μrecon = -2.7×10-3 mm-1,σrecon = 7.0×10-3 mm-1) and (μCT = -2.5×10-3 mm-1,σCT = 5.3×10-3 mm-1), respectively. The agreement of local geometry properties between the reconstructed surfaces and the CT surface demonstrated the ability of the proposed method in faithfully representing the underlying patient surface. Conclusions: The authors have integrated and developed an accurate level-set based continuous surface reconstruction method on point clouds acquired by a 3D surface photogrammetry system. The proposed method has generated a continuous representation of the underlying phantom and patient surfaces with good robustness against noise and missing measurements. It serves as an important first step for further development of motion tracking methods during radiotherapy. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we compared the cytotoxic effects of natural conjugated linolenic acids (CLnAs) on human adenocarcinoma cells (DLD-1) in vitro, with the goal of finding CLnA isomers with strong cytotoxic effects. The antitumor effect of the CLnA with the strongest cytotoxic effect was then examined in mice. The results showed that all CLnA isomers have strong cytotoxic effects on DLD-1 cells, with jacaric acid (JA) having the strongest effect. Examination of the mechanism of cell death showed that CLnAs induce apoptosis in DLD-1 cells via lipid peroxidation. The intracellular levels of incorporated CLnAs were measured to examine the reason for differences in cytotoxic effects. These results showed that JA was taken into cells efficiently. Collectively, these results suggest that the cytotoxic effect of CLnAs is dependent on intracellular incorporation and induction of apoptosis via lipid peroxidation. JA also had a strong preventive antitumor effect in vivo in nude mice into which DLD-1 cells were transplanted. These results suggest that JA can be used as a dietary constituent for prevention of cancer. [Copyright &y& Elsevier]

Membrane proteins change their conformations in response to chemical and physical stimuli and transmit extracellular signals inside cells. Several approaches have been developed for solving the structures of proteins. However, few techniques can monitor real-time protein dynamics. The diffracted X-ray tracking method (DXT) is an X-ray-based single-molecule technique that monitors the internal motion of biomolecules in an aqueous solution. DXT analyzes trajectories of Laue spots generated from the attached gold nanocrystals with a two-dimensional axis by tilting (θ) and twisting (χ). Furthermore, high-intensity X-rays from synchrotron radiation facilities enable measurements with microsecond-timescale and picometer-spatial-scale intramolecular information. The technique has been applied to various membrane proteins due to its superior spatiotemporal resolution. In this review, we introduce basic principles of DXT, reviewing its recent and extended applications to membrane proteins and living cells, respectively. [ABSTRACT FROM AUTHOR]

Acetazolamide (ACZ) is used to prevent acute mountain sickness at altitude. Because it could affect O2 transport in several different and potentially conflicting ways, we examined its effects on pulmonary and muscle gas exchange and acid–base status during cycle exercise at ∼30, 50 and 90% in normoxia and acute hypoxia . In a double-blind, order-balanced, crossover design, six healthy, trained men (normoxic = 59 ml kg−1 min−1) exercised at both values after ACZ (3 doses of 250 mg, 8 h apart) and placebo. One week later this protocol was repeated using the other drug (placebo or ACZ). We measured cardiac output , leg blood flow (LBF), and muscle and pulmonary gas exchange, the latter using the multiple inert gas elimination technique. ACZ did not significantly affect , , LBF or muscle gas exchange. As expected, ACZ led to lower arterial and venous blood [HCO3−], pH and lactate levels ( P < 0.05), and increased ventilation ( P < 0.05). In both normoxia and hypoxia, ACZ resulted in higher arterial PO2 and saturation and a lower alveolar–arterial PO2 difference (Aa DO2) due to both less mismatch and less diffusion limitation ( P < 0.05). In summary, ACZ improved arterial oxygenation during exercise, due to both greater ventilation and more efficient pulmonary gas exchange. However, muscle gas exchange was unaffected. [ABSTRACT FROM AUTHOR]

Cells for therapeutic use are often preserved at +4 °C, and the storage period is generally limited to 2–3 days. Here, we report that the survival rate (%) of mammalian cells is improved to 10–20 days when they are preserved with a subzero supercooled solution containing the antifreeze protein (AFP), for which an ability to stabilize both supercooled water and cell membrane integrity has been postulated. We chose adherent rat insulinoma (RIN-5F) cells as the preservation target, which were immersed into −5 °C-, −2 °C-, or +4 °C-chilled "unfrozen" solution of Euro-Collins or University of Washington (UW) containing the AFP sample obtained from insect or fish. Our results show that the survival rate of the cells preserved with the solution containing insect AFP was always higher than that of the fish AFP solution. A combination of the −5 °C-supercooling and insect AFP gave the best preservation result, namely, UW solution containing insect AFP kept 53% of the cells alive, even after 20 days of preservation at −5 °C. The insect AFP locates highly organized ice-like waters on its molecular surface. Such waters may bind to semiclathrate waters constructing both embryonic ice crystals and a membrane–water interface in the supercooled solution, thereby protecting the cells from damage due to chilling. [ABSTRACT FROM AUTHOR]

Tetra[2,3-thienylene] planarised by sulphur bridges and radially π-extended with (triisopropylsilyl)ethynyl groups had a narrow HOMO–LUMO gap due to the antiaromatic cyclooctatetraene core, and its single crystal FET device exhibited ambipolar characteristics with hole and electron mobilities of up to 0.40 and 0.18 cm2 V−1 s−1, respectively. [ABSTRACT FROM AUTHOR]

The concentration of a protein is highly related to its biochemical properties, and is a key determinant for its biotechnological applications. Antifreeze proteins (AFPs) and antifreeze glycoproteins (AFGPs) are structurally diverse macromolecules that are capable of binding to embryonic ice crystals below 0 °C, making them useful as protectants of ice-block formation. In this study, we examined the maximal solubility of native AFP I–III and AFGP with distilled water, and evaluated concentration dependence of their ice-binding property. Approximately 400 mg/mL (AFP I), 200 mg/mL (AFP II), 100 mg/mL (AFP III), and >1800 mg/mL (AFGP) of the maximal solubility were estimated, and among them AFGP's solubility is much higher compared with that of ordinary proteins, such as serum albumin (~500 mg/mL). The samples also exhibited unexpectedly high thermal hysteresis values (2–3 °C) at 50–200 mg/mL. Furthermore, the analysis of fluorescence-based ice plane affinity showed that AFP II binds to multiple ice planes in a concentration-dependent manner, for which an oligomerization mechanism was hypothesized. The difference of concentration dependence between AFPs and AFGPs may provide a new clue to help us understand the ice-binding function of these proteins. [ABSTRACT FROM AUTHOR]