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Chirality has an important impact on chemical and biological research, as most active substances are chiral. In recent decades, metal–organic frameworks (MOFs), which are assembled from metal ions or clusters and organic linkers via metal–ligand bonding, have attracted considerable scientific interest due to their high crystallinity, exceptional porosity and tunable pore sizes, high modularity, and diverse functionalities. Since the discovery of the first functional chiral metal–organic frameworks (CMOFs), CMOFs have been involved in a variety of disciplines such as chemistry, physics, optics, medicine, and pharmacology. The introduction of defect engineering theory into CMOFs allows the construction of a class of defective CMOFs with high hydrothermal stability and multi-stage pore structure. The introduction of defects not only increases the active sites but also enlarges the pore sizes of the materials, which improves chiral recognition, separation, and catalytic reactions, and has been widely investigated in various fields. This review describes the design and synthesis of various defective CMOFs, their characterization, and applications. Finally, the development of the materials is summarized, and an outlook is given. This review should provide researchers with an insight into the design and study of complex defective CMOFs. [ABSTRACT FROM AUTHOR]

We prove the existence and uniqueness of solution of the loop equation associated with a semisimple generalized Frobenius manifold with non-flat unity, and show, for a particular example of one-dimensional generalized Frobenius manifold, that the deformation of the Principal Hierarchy induced by the solution of the loop equation is the extended q-deformed KdV hierarchy. [ABSTRACT FROM AUTHOR]

Location recommendation is at the core of location-based service, while recommendation based on graph neural networks (GNNs) has recently flourished, and for location recommendation tasks, GNN-based approaches are equally applicable. To provide fair location recommendation services for multi-users, correlation information between non-adjacent locations and non-consecutive visits is essential information in understanding user behavior. The key to GNN-based location recommendation is how to use GNNs to learn embedding representations for users and locations according to their neighbors. Existing approaches usually focus on how to aggregate information from the perspective of spatial structural information, but temporal information about neighboring nodes in the graph has not been fully exploited. In this paper, a GNN location recommendation model, STAGNN, is proposed to incorporate spatio-temporal information to support fairness-driven location-based service. STAGNN facilitates the progression from spatial to spatio-temporal by generating spatio-temporal embeddings from the perspective of spatial structural information and temporal information. STAGNN also explicitly uses spatio-temporal information of all check-ins through an extended attention layer, an improvement that incorporates non-adjacent locations and non-consecutive visits between point-to-point interactions into the learning of user/location embedding representations with significant spatio-temporal effects. STAGNN also employs a multi-head attention mechanism. Experimental results demonstrate that STAGNN brings a good improvement in GNN-based location recommendation, outperforming the optimal baseline by 6%-11% on the three datasets under the HR@20 evaluation metric. [ABSTRACT FROM AUTHOR]

Petroleum industry has started to embrace the advanced petroleum cyber-physical system (CPS) technologies. Offshore petroleum CPS is particularly hard to build, mainly due to the difficulty in detecting and preventing offshore oil leaking. During the oil exploration and transportation process, the remote multi-sensing technology is typically employed for emerging service. It can be utilized for leak detection by enabling the underwater modeling of an offshore petroleum CPS. However, such a technology suffers from insufficient remote sensing resources and expensive computational overhead. In this work, a cross-entropy based leak detection technique is proposed to detect the oil leak, which facilitates the understanding of the oil leak induced marine pollution. Furthermore, a hierarchical parallel approach is proposed on the super computer Tianhe-2 to improve the efficiency of the proposed leak detection technique. Experimental results on Penglai oil spill events demonstrate that the proposed method can effectively identify the sources of oil spilling with accuracy up to 100 % . [ABSTRACT FROM AUTHOR]

Image colorization refers to computer-aided rendering technology which transfers colors from a reference color image to grayscale images or video frames. Deep learning elevated notably in the field of image colorization in the past years. In this paper, we formulate image colorization methods relying on exemplar colorization and automatic colorization, respectively. For hybrid colorization, we select appropriate reference images to colorize the grayscale CT images. The colours of meat resemble those of human lungs, so the images of fresh pork, lamb, beef, and even rotten meat are collected as our dataset for model training. Three sets of training data consisting of meat images are analysed to extract the pixelar features for colorizing lung CT images by using an automatic approach. Pertaining to the results, we consider numerous methods (i.e., loss functions, visual analysis, PSNR, and SSIM) to evaluate the proposed deep learning models. Moreover, compared with other methods of colorizing lung CT images, the results of rendering the images by using deep learning methods are significantly genuine and promising. The metrics for measuring image similarity such as SSIM and PSNR have satisfactory performance, up to 0.55 and 28.0, respectively. Additionally, the methods may provide novel ideas for rendering grayscale X-ray images in airports, ferries, and railway stations. [ABSTRACT FROM AUTHOR]

Early diagnosis of acute myeloid leukemia (AML) in the pre-leukemic stage remains a clinical challenge, as pre-leukemic patients show no symptoms, lacking any known morphological or numerical abnormalities in blood cells. Here, we demonstrate that platelets with structurally abnormal mitochondria emerge at the pre-leukemic phase of AML, preceding detectable changes in blood cell counts or detection of leukemic blasts in blood. We visualized frozen-hydrated platelets from mice at different time points during AML development in situ using electron cryo-tomography (cryo-ET) and identified intracellular organelles through an unbiased semi-automatic process followed by quantitative measurement. A large proportion of platelets exhibited changes in the overall shape and depletion of organelles in AML. Notably, 23% of platelets in pre-leukemic cells exhibit abnormal, round mitochondria with unfolded cristae, accompanied by a significant drop in ATP levels and altered expression of metabolism-related gene signatures. Our study demonstrates that detectable structural changes in pre-leukemic platelets may serve as a biomarker for the early diagnosis of AML. Wang et al characterise platelets in a mouse model of acute myeloid leukemia (AML) using Cryo-electron tomography (Cryo-ET) and find that 23% of platelets in pre-leukemic cells exhibit abnormal, round mitochondria with unfolded cristae. They also detect reduced ATP levels and altered expression of metabolism-related genes, altogether suggesting that platelet alterations may serve as a biomarker for AML. [ABSTRACT FROM AUTHOR]

Port-city system is a complex and integral system, and it can be simulated by system dynamic method, which is used to be employed to solve nonlinear problems. Based on the causality of the every element in the port-city system, the authors analyzed the feedback relation and logical relation among the system variables and system structure. A system-dynamic flow chart and correlation equations were put forward with VENSIM software, the quantitative relation was described, and the model was debugged. The development trend of the main influence factors in port-city system was simulated. By changing the parameters values of variables in the model, we studied the influence degree of each related factor. It is found that: 1) Foreign trade throughput of port play an important role in the development of export-oriented economy. 2) The development of primary industry and secondary industry affects most of the water transportation demand. With the constant increase of tertiary industry proportion in the industrial structure, the demand of national economy for water transportation decreases gradually. 3) Water transportation presents a kind of oversupply development situation, so port construction should properly slow down. 4) With the development of ports, its direct and indirect contribution to urban economy has been continuously increasing, but contribution rate will be continuously decreasing. [ABSTRACT FROM AUTHOR]

The existing SCSI parallel bus has been widely used in various multimedia applications. However, due to the unfair bus accesses the SCSI bus may not be able to fully utilize the potential aggregate throughput of disks. The number of disks that can be attached to the SCSI bus is limited, and link level fault tolerance is not provided. The serial storage interfaces such as Serial Storage Architecture (SSA) provide high data bandwidth, fair accesses, long transmission distance between adjacent devices (disks or hosts) and link level fault tolerance. The fairness algorithm of SSA ensures a fraction of data bandwidth to be allocated to each device. In this paper we would like to know whether SSA is a better alternative in supporting continuous media than SCSI. The scalability of a multimedia server is very important since the storage requirement may grow incrementally as more contents are created and stored. SSA in a shared-storage cluster environment also supports concurrent accesses by different hosts as long as their access paths are not overlapped. This feature is called spatial reuse. Therefore, the effective bandwidth over an SSA can be higher than the raw data bandwidth and the spatial reuse feature is critical to the scalability of a multimedia server. This feature is also included in FC-AL3 with a new mode called Multiple Circuit Mode (MCM). Using MCM, all devices can transfer data simultaneously without collision. In this paper we have investigated the scalability of shared-stroage clusters over an SSA environment. [ABSTRACT FROM AUTHOR]

Digital libraries require not only high storage space capacity but also high performance storage systems which provide the fast accesses to the data. These requirements can not be efficiently supported with the traditional SCSI interfaces. Several serial storage interfaces have been proposed for constructing storage systems with high transfer bandwidth, large storage capacity, and fault tolerance feature. Among them, Serial Storage Architecture (SSA) and Fibre Channel-Arbitrated Loop (FC-AL) are considered as the next generation storage interfaces with broad industry support. Both technologies support simple cabling, long transmission distance, high data bandwidth, large capacity, fault tolerance, and fair sharing of link bandwidth. In this paper, a tutorial and a comparison of these two technologies are presented. The tutorial examines their interface specifications, transport protocols, fairness algorithms, and capabilities of fault tolerance. The comparison focuses on their protocol overhead, flow control, fairness algorithms, and fault tolerance. The paper also summarizes the recently proposed Aaron Proposal which incorporates features from both SSA and FC-AL and targets at merging these two technologies. [ABSTRACT FROM AUTHOR]

A video-on-demand (VOD) server needs to store hundreds of movie titles and to support thousands of concurrent accesses. This, technically and economically, imposes a great challenge on the design of the disk storage subsystem of a VOD server. Due to different demands for different movie titles, the numbers of concurrent accesses to each movie can differ a lot. We define access profile as the number of concurrent accesses to each movie title that should be supported by a VOD server. The access profile is derived based on the popularity of each movie title and thus serves as a major design goal for the disk storage subsystem. Since some popular (hot) movie titles may be concurrently accessed by hundreds of users and a current high-end magnetic disk array (disk) can only support tens of concurrent accesses, it is necessary to replicate and/or stripe the hot movie files over multiple disk arrays. The consequence of replication and striping of hot movie titles is the potential increase on the required number of disk arrays. Therefore, how to replicate, stripe, and place the movie files over a minimum number of magnetic disk arrays such that a given access profile can be supported is an important problem. In this paper, we formulate the problem of the video file allocation over disk arrays, demonstrate that it is a NP-hard problem, and present some heuristic algorithms to find the near-optimal solutions. The result of this study can be applied to the design of the storage subsystem of a VOD server to economically minimize the cost or to maximize the utilization of disk arrays. [ABSTRACT FROM AUTHOR]