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The Bardeen-Cooper-Schrieffer (BCS) condensation and the Bose-Einstein condensation (BEC) are the two extreme limits of the ground state of the paired fermion systems. We report crossover behavior from the BCS condensation to the BEC realized in the two-dimensional (2D) superconductor, electron doped layered material ZrNCl. The phase diagram, established by simultaneous experiments of resistivity and tunneling spectra under the ionic gating, demonstrates the pseudogap phase at the low doping regime. In the low carrier density limit, $T_{\rm BKT}$ (Berezinskii-Kosterlitz-Thouless transition temperature for 2D superconductors) scales as $T_{\rm BKT}/T_{\rm F} = 0.12$, where $T_{\rm F}$ is the Fermi temperature, which is consistent with the theoretical upper bound expected in the BCS-BEC crossover regime. The present results indicate that the gate-doped semiconductor provides an ideal platform for the 2D BCS-BEC crossover without any added complexity, such as magnetic orders and density waves., 49 pages, 12 figures

Engineering interface polarization Many properties can emerge at the interface of van der Waals materials created by rotating the layers of a single material or by creating heterointerfaces between different materials. Akamatsu et al. formed an interface that intentionally broke in-plane inversion symmetry by combining crystals of tungsten diselenide with threefold rotational symmetry and black phosphorus with twofold rotational symmetry. This interface creates in-plane electronic polarization that results in a spontaneous photovoltaic effect only along the polarization direction. This effect was explained in terms of a shift current mechanism. Science , this issue p. 68

Spin-torque oscillators (STOs) are unique spintronic devices in which spin current induces the precession of magnetization in the oscillation layer. In this study, we demonstrate coupled out-of-plane oscillation between two oscillation layers within an STO. The coupled oscillation state is observed in the magnetoresistance spectra as well as its degradation due to the mixing of the free oscillation state depending on the bias current. These behaviors are analytically described and numerically reproduced based on the Landau–Lifshitz–Gilbert equation. Since the STO is fabricated in the write head of a hard disk drive, the coupled oscillation state and the subsequent microwave magnetic field are applicable for microwave-assisted magnetic recording for high-density recording.

Corneal opacities are an important cause of blindness, and its major etiology is infectious keratitis. Slit-lamp examinations are commonly used to determine the causative pathogen; however, their diagnostic accuracy is low even for experienced ophthalmologists. To characterize the “face” of an infected cornea, we have adapted a deep learning architecture used for facial recognition and applied it to determine a probability score for a specific pathogen causing keratitis. To record the diverse features and mitigate the uncertainty, batches of probability scores of 4 serial images taken from many angles or fluorescence staining were learned for score and decision level fusion using a gradient boosting decision tree. A total of 4306 slit-lamp images and 312 images obtained by internet publications on keratitis by bacteria, fungi, acanthamoeba, and herpes simplex virus (HSV) were studied. The created algorithm had a high overall accuracy of diagnosis, e.g., the accuracy/area under the curve (AUC) for acanthamoeba was 97.9%/0.995, bacteria was 90.7%/0.963, fungi was 95.0%/0.975, and HSV was 92.3%/0.946, by group K-fold validation, and it was robust to even the low resolution web images. We suggest that our hybrid deep learning-based algorithm be used as a simple and accurate method for computer-assisted diagnosis of infectious keratitis.

Two-dimensional (2D) crystals are attracting growing interest in various research fields such as engineering, physics, chemistry, pharmacy, and biology owing to their low dimensionality and dramatic change of properties compared to the bulk counter parts. Among the various techniques used to manufacture 2D crystals, mechanical exfoliation has been essential to practical applications and fundamental research. However, mechanically exfoliated crystals on substrates contain relatively thick flakes that must be found and removed manually, limiting high-throughput manufacturing of atomic 2D crystals and van der Waals heterostructures. Here, we present a deep-learning-based method to segment and identify the thickness of atomic layer flakes from optical microscopy images. Through carefully designing a neural network based on U-Net, we found that our neural network based on U-net trained only with the data based on realistically small number of images successfully distinguish monolayer and bilayer MoS2 and graphene with a success rate of 70–80%, which is a practical value in the first screening process for choosing monolayer and bilayer flakes of all flakes on substrates without human eye. The remarkable results highlight the possibility that a large fraction of manual laboratory work can be replaced by AI-based systems, boosting productivity.

Interfaces of two dimensional van der Waals crystals are unique material platforms in which we can explore the emergent physical properties and functionalities by selecting the appropriate material combinations and by designing the symmetry of the interface.

Van der Waals (vdW) heterostructures have attracted great interest because of their rich material combinations. The discovery of two-dimensional magnets has provided a new platform for magnetic vdW heterointerfaces; however, research on magnetic vdW heterointerfaces has been limited to those with ferromagnetic surfaces. Here, we report a magnetic vdW heterointerface using layered intralayer-antiferromagnetic MPSe3 (M = Mn, Fe) and monolayer transition-metal dichalcogenides (TMDs). We found an anomalous upshift of the excitonic peak in monolayer TMDs below the antiferromagnetic transition temperature in the MPSe3, capturing a signature of the interlayer exciton-magnon coupling. This is a concept extended from single materials to heterointerfaces. Moreover, this coupling strongly depends on the in-plane magnetic structure and stacking direction, showing its sensitivity to their magnetic interfaces. Our finding offers an opportunity to investigate interactions between elementary excitations in different materials across interfaces and to search for new functions of magnetic vdW heterointerfaces.

Material structures containing tetrahedral FeAs bonds, depending on their density and geometrical distribution, can host several competing quantum ground states ranging from superconductivity to ferromagnetism. Here we examine structures of quasi two-dimensional (2D) layers of tetrahedral Fe-As bonds embedded with a regular interval in a semiconductor InAs matrix, which resembles the crystal structure of Fe-based superconductors. Contrary to the case of Fe-based pnictides, these FeAs/InAs superlattices (SLs) exhibit ferromagnetism, whose Curie temperature (TC) increases rapidly with decreasing the InAs interval thickness tInAs (TC ∝ tInAs−3), and an extremely large magnetoresistance up to 500% that is tunable by a gate voltage. Our first principles calculations reveal the important role of disordered positions of Fe atoms in the establishment of ferromagnetism in these quasi-2D FeAs-based SLs. These unique features mark the FeAs/InAs SLs as promising structures for spintronic applications., In this manuscript, the authors grow very thin layers of FeAs in a matrix of InAs. The resulting superlattice displays ferromagnetism, with the Curie temperature varying depending on the layer thickness. These results further illustrate the wide array of intriguing ground states of materials with tetrahedral FeAs bonds

Quantifying tree damage and mortality caused by single-tree selection harvesting is critical to understanding postharvest forest dynamics and management. In this study, we quantified the effects of tree size and species and the distance from residual trees to felled trees and skid trails on damage to residual trees and mortality in mixed coniferous–broadleaved stands of Hokkaido, northern Japan. Among the 4,961 trees that we studied, 373 (7.5 %) were damaged, and 148 of these trees (3.0 %) died during or immediately after logging. Hierarchical Bayesian modeling showed that the risk of damage to residual trees increased with increasing size of the felled trees and with increasing proximity to felled trees and skid trails. Smaller residual trees had the greatest risk of damage. Species differed in their susceptibility to damage; Abies sachalinensis (Fr. Schm.) Masters and Picea jezoensis (Sieb. et Zucc.) Carr. were the most susceptible species in our sample plots. Smaller damaged trees had the highest risk of mortality. The damaged trees that did not die at the time of logging had a higher risk of postharvest mortality than undamaged trees. Our results indicate that, to minimize logging-induced damage and mortality: (1) the spatial arrangement of skid trails should be optimized and fixed, (2) the risk of skidding damage should be considered before marking the trees to be harvested and choosing the felling direction, and (3) logging operators should be instructed to avoid damaging small trees, especially those of the species that are most susceptible to damage.

Competition among individual trees is a fundamental structuring fea- ture of uneven-aged mixed-species stands. We developed a Bayesian model for neighborhood competition in uneven-aged mixed-species stands, in which the interspecic variability in competitive impact is explicitly represented. We used data from 16 permanent plots in the University of Tokyo Hokkaido Forest, where the diameter at breast height (DBH) of all trees has been repeatedly measured and mapped. To analyze the competitive effect of neighboring trees, we used the "Neighboring Competition Index, "an index in which the competitive effect of neighboring trees is predicted as a function of its DBH, dis- tance from the target tree, and its species. Among three alternative models, a model that represented the interspecic variability to have a common mean value using hierarchical parameter structure exerted the lowest DIC (a criterion for model selection), followed by a model that represented it to be independent. The estimated interspecic variability was smaller than previously reported, in that we found only three out of 39 species were considered to have a signicant dif- ference from other species. Our results showed that although there is clear evidence for interspecic variability, the species-specic effects are not independent of one another, but rather have some similarity. Our results provide a novel approach for efficiently predicting the complex competition in uneven-aged mixed-species stands.

Product customization has been popular since Internet shopping began. Many firms have introduced customization configuration systems, allowing customers to choose a wide range of product attributes, attracting them to participate in the shopping process, and increasing customer satisfaction. Paradoxically, the attribute-by-attribute (AbA) choice in the customization process requires a high-information processing load resulting in shopper confusion. To reduce this confusion, the CvSS (customization via starting solution) system has recently been developed. However, this system provides solution support only for the starting point of the configuration process. Thus, in this study, the authors proposes the CvWS (Customization via Waypoint Solutions) system, which would greatly reduce the customer effort needed to complete the configuration process by using a novel approach to solve the nonlinear knapsack problem. The newly proposed system is theoretically compared with the AbA customization as well as the CvSS system. Also, its feasibility is discussed in the context of the nonlinear multiconstraint knapsack problem.

Prostaglandin F(2alpha) (PGF) induces a rapid reduction in progesterone production (functional luteolysis) followed by tissue degeneration and cell death (structural luteolysis). Reactive oxygen species (ROS) including nitric oxide (NO) play crucial roles in the luteolytic action of PGF. The local concentration of intraluteal ROS is controlled by superoxide dismutase (SOD), the main enzyme involved in the control of intraluteal ROS. To clarify the roles of NO in the regulation of SOD in luteolysis, we examined the effects of NO on SOD expression and activity in cultured bovine luteal endothelial cells (LECs) during short-term (2 h, mimicking functional luteolysis) and long-term (24 h, mimicking structural luteolysis) incubation. We also investigated whether NO modulates PGF production by LECs. LECs were isolated from mid-luteal phase CLs, and exposed to NONOate (a NO donor) for 2 or 24 h. SOD mRNA expression was stimulated by NONOate (10-100 microM) at 2 h (P0.05). Moreover, 10 microM NONOate stimulated SOD protein expression and SOD activity at 2 h (P0.05), whereas NONOate inhibited SOD mRNA and protein expressions at 24 h (P0.05). NONOate stimulated PGF biosynthesis at both incubation times. The overall findings suggest that NO differently regulates SOD in cultured LECs, depending on the exposure time. Acute elevation of SOD may represent a response of LECs to protect themselves against oxidative stress induced by PGF during functional luteolysis, whereas a later reduction of SOD levels by NO may facilitate an excess of intraluteal ROS during structural luteolysis.

When designing a system, there are two methods that can be used to improve the system's reliability without changing the nature of the system: 1) using more reliable components, and/or 2) providing redundant components within the system. The redundancy allocation problem attempts to find the appropriate mix of components & redundancies within a system in order to either minimize cost subject to a minimum level of reliability, or maximize reliability subject to a maximum cost and weight. Redundancy allocation problems can be classified into two groups; one allows the system to have a mix of components with different characteristics incorporated in the system, while the other only allows one type of each component. The former group has a much larger solution space compared to the latter, and therefore obtaining an exact optimal or even a high quality solution for this problem may be more difficult. Optimization techniques, based on meta-heuristic approaches, have recently been proposed to solve the redundancy allocation problem with a mix of components. However, an exact solution method has not been developed. In this paper, we develop an exact solution method, based on the improved surrogate constraint (ISC) method, and use this method to find optimal solutions to problems previously presented in the literature

Using 1,2,4-triphenylbenzene as a photosensitizer, the photoamination of alkenes and alkadienes (1), which had no absorption at >300 nm proceeded efficiently in the presence of p-dicyanobenzene to give addition products by incorporating both amino and p-cyanophenyl groups. The reaction efficiency was discussed in terms of the relationships between 1 and the photosensitizer in their oxidation potentials and the distribution of positive charge on the reaction site of the cation radical of 1 (1+ ).

Symmetry-breaking has been known to play a key role in noncentrosymmetric superconductors with strong spin-orbit-interaction (SOI). The studies, however, have been so far mainly focused on a particular type of SOI, known as Rashba SOI, whereby the electron spin is locked to its momentum at a right-angle, thereby leading to an in-planar helical spin texture. Here we discuss electric-field-induced superconductivity in molybdenum disulphide (MoS2), which exhibits a fundamentally different type of intrinsic SOI manifested by an out-of-plane Zeeman-type spin polarization of energy valleys. We find an upper critical field of approximately 52 T at 1.5 K, which indicates an enhancement of the Pauli limit by a factor of four as compared to that in centrosymmetric conventional superconductors. Using realistic tight-binding calculations, we reveal that this unusual behaviour is due to an inter-valley pairing that is symmetrically protected by Zeeman-type spin-valley locking against external magnetic fields. Our study sheds a new light on the interplay of inversion asymmetry with SOI in confined geometries, and its unprecedented role in superconductivity., 37 pages, 11 figures, http://meetings.aps.org/Meeting/MAR15/Session/G11.11

Background Long‐term survival has not been described following surgical resection for liver metastasis after radical resection of an advanced hilar bile duct carcinoma (Klatskin tumour). One such patient who developed liver metastasis after radical treatment for stage IVA (pTNM) hilar cholangiocarcinoma has survived 5.5 years after resection of the liver metastasis followed by chemotherapy. Case report A 50‐year‐old man developed a solid liver metastasis in segment VIII 17 months after radical resection of a stage IVA (pT3 pN1 M0) Klatskin tumour followed by postoperative radiotherapy (54 Gy) and systemic chemotherapy (oral UFT 450 mg/day plus intravenous cisplatin 20 mg on 5 consecutive days each month). The patient is alive at 7 years after the primary resection followed by resection of the liver metastasis plus further systemic chemotherapy comprising oral UFT combined with intravenous adriamycin (ADM) and mitomycin C (MMC). Conclusion Aggressive salvage resection surgery can be an effective component of a multidisciplinary treatment regimen, even for a postoperative liver metastasis that developed after radical resection of an advanced Klatskin tumour, provided that the metastasis is solid and has not failed local‐regional control.

An improved surrogate constraints method for solving separable nonlinear integer programming problems with multiple constraints is presented. The surrogate constraints method is very effective in solving problems with multiple constraints. The method solves a succession of surrogate constraints problems having a single constraint instead of the original multiple constraint problem. A surrogate problem with an optimal multiplier vector solves the original problem exactly if there is no duality gap. However, the surrogate constraints method often has a duality gap, that is it fails to find an exact solution to the original problem. The modification proposed closes the surrogate duality gap. The modification solves a succession of target problems that enumerates all solutions hitting a particular target. The target problems are produced by using an optimal surrogate multiplier vector. The computational results show that the modification is very effective at closing the surrogate gap of multiple constraint problems.

Retroperitoneal dedifferentiated liposarcoma is associated with a poor prognosis, and the efficacy of chemotherapy in such cases is controversial. We report a case of long -term survival in a patient with dedifferentiated liposarcoma treated with bevacizumab after repeated local recurrences. A 65-year-old man complained of abdominal pain. Abdominal computed tomography (CT) showed a well-enhanced retroperitoneal tumor. The tumor was resected together with the right kidney and adrenal gland. On the basis of histopathological findings, the tumor was diagnosed as a dedifferentiated liposarcoma adenocarcinoma. Eleven months later, local recurrence was diagnosed and the tumor was resected. Thereafter, repeated local recurrences were diagnosed, and repeated tumor resections were performed. Local recurrence and distant metastasis in the axilla and scapula soft tissue was detected 5.9 years after the initial operation. Bevacizumab therapy was initiated, and the tumor markedly reduced in size. Bevacizumab treatment has been continued for 6.7 years after the initial operation, with no tumor recurrence or metastasis.

An upper bound or a lower bound of the Multiple-Choice Knapsack Problem can be calculated by solving LP relaxation. In 1979, Sinha and Zoltners proposed a branch-and-bound algorithm for solving the Multiple-Choice Knapsack Problem, and provided a method to obtain the strict upper bound. In this paper, we propose a new calculation method to obtain a stricter upper bound than the upper bound of Sinha–Zoltners and compare the results of the two methods. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(7): 22–27, 2001

A heuristic procedure called Smart Greedy is proposed for solving a nonlinear knapsack class of reliability optimization problems with multiple constraints (multidimensional nonlinear knapsack problems). At first, by using a surrogate multiplier, the multidimensional nonlinear knapsack problem is translated into an one-dimensional nonlinear knapsack problem, which is called the surrogate problem. Second, modular approach (MA) solves the surrogate problem with the surrogate multiplier given as a centroid of the current polyhedron. Algorithm cut-off polyhedron (COP) provides a cutting plane of the polyhedron, and reduces the polyhedron recursively until the polyhedron becomes empty. Finally, a procedure called Smart Greedy generates an approximate solution of the surrogate problem with the surrogate multiplier finally obtained. The solution obtained is called Smart Greedy solution, which is feasible to the original problem. The computational experiments show hat the present algorithm provides high quality solutions.

In this paper we propose an approximate method for nonlinear integer programming problems. A nonlinear integer programming problem is written as a multidimensional nonlinear knapsack problem. The multidimensional nonlinear knapsack problem can be solved even if the objective and constraint functions of the original nonlinear integer programming problems are nonconvex and undifferentiable. It is difficult to solve large-scale multidimensional nonlinear knapsack problems exactly. Therefore, it is important to develop an effective approximate method for such problems. We propose an approximate method to solve the multidimensional nonlinear knapsack problems using the surrogate constraints method and use the method to solve nonlinear integer programming problems. The proposed approximate method provides an upper bound and an approximate solution that provides a lower bound. We can evaluate the quality of the approximate solution to compare the lower bound with the upper bound. Computational experiments show that the proposed method provides high-quality approximate solutions. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 82(4): 64–70, 1999