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Antibodies against immune checkpoint molecules restore T-cell function by inhibiting the binding of PD-1 and PD-L1 and have been shown to exert therapeutic effects in various human cancers. However, to date, no monoclonal antibody that recognizes feline PD-1 or PD-L1 has been reported, and there are many unknowns regarding the expression of immune checkpoint molecules and their potential as therapeutic targets in cats. Here we developed anti-feline PD-1 monoclonal antibody (1A1-2), and found that the monoclonal antibody against anti-canine PD-L1 (G11-6), which was previously developed in our laboratory, cross-reacted with feline PD-L1. Both antibodies inhibited the interaction of feline PD-1 and feline PD-L1 in vitro. These inhibitory monoclonal antibodies augmented the interferon-gamma (IFN-γ) production in activated feline peripheral blood lymphocytes (PBLs). Furthermore, for clinical application in cats, we generated a mouse-feline chimeric mAb by fusing the variable region of clone 1A1-2 with the constant region of feline IgG1 (ch-1A1-2). Ch-1A1-2 also augmented the IFN-γ production in activated feline PBLs. From this study, 1A1-2 is first anti-feline PD-1 monoclonal antibody with the ability to inhibit the interaction of feline PD-1 and PD-L1, and the chimeric antibody, ch-1A1-2 will be a beneficial therapeutic antibody for feline tumors.

As the Internet of Things (IoT) has become a widespread phenomenon, promising sensor applications at the nanoscale have begun to emerge. One example is imaging via distributed massive nanoscale nodes (NSNs), which can be used to implement “invisible surveillance cameras” by, for example, painting liquids containing nanoscale sensors onto walls. This imaging method requires periodic data transfer from thousands of NSNs to a data collection node (DCN). An essential technique for handling such transfers is the media access control (MAC) protocol. However, existing protocols cannot support periodic transfer from numerous NSNs because of inefficient communication caused by a large amount of headers in the packets. In this article, we introduce an original MAC protocol and discuss its capability in terms of implementing imaging applications. The proposed protocol applies a time-division access (TDA) feature to reduce the amount of headers and a two-layered protocol to enable simultaneous transmission among nodes. Slot assignment is an essential function in TDA and requires communication among nodes. Unlike existing methods, our simple approach enables communication by exploiting the unique features of the focused application. The results of the numerical simulation reveal that the proposed MAC protocol allows for periodic imaging with more than three thousand nodes and produces high-quality images very close to those obtained using ideal communication. These results are achieved by employing an original design framework to determine appropriate key parameters, such as the number of clusters and frame rate.

The recent development of mobile sensing nodes, such as unmanned vehicles, has enabled novel sensing applications. In these applications, the nodes periodically send data required for control, such as the position and velocity as well as data sensed data while moving. Prioritized communication is preferable for securing reliable data transfer for control. However, existing methods used for mobile sensor networks do not offer prioritized periodical communication. Herein, we introduce prioritized periodical communication with timing-reservation multiple access. In this method, response frames are extended to communicate the priority level of the transmitted frame. Numerical results show that high-priority data can be transmitted more accurately using the proposed method compared with existing methods, even in a heavy traffic scenario.

The Internet of things has reached the nanoscale, and many applications using the nanoscale size of sensors are emerging. One example is imaging by distributed massive nanoscale nodes. This technique could realize an "invisible surveillance camera" by, for example, painting a liquid that contains the nanoscale sensors on a wall. This imaging method requires periodical data transfer from thousands of nanoscale nodes to a data collection node. The essential technique for handling transmission is Media Access Control (MAC). However, existing MAC protocols, like IEEE 802.11 CSMA/CA, cannot support data transfer among thousands of nodes. In this paper, we introduce a time division multiple access-based MAC protocol and evaluate its imaging performance. Our proposed method is clustering-based, two-layered protocol. A key parameter in the protocol design is the number of clusters as it determines how many sensors can successfully transmit data. Our numerical investigation shows that, depending on the transmission period, a certain number of the cluster achieves a high quality obtained image. Under this setting, a high reception rate is achieved, which significantly contributes to reliable data transfer.

Progress in nanoelectromechanical systems has enabled the development of nanoscale sensor nodes, allowing novel applications. To realize such applications, a media access control (MAC) protocol that supports periodic data collection from a massive number of nodes is required. When extremely small data packets (e.g., 3 bytes) are transmitted, the header in a packet is much larger than the data, decreasing node capacity and the data collection rate due to redundant header information. This study proposes a MAC protocol that employs centralized control with time division multiple access and data aggregation to decrease header size. We analytically demonstrate the enhancement of the data collection rate. The results show that the proposed protocol can be used to achieve a high data collection rate from thousands of nanoscale nodes.