This paper presents the development of a non-contact, nonintrusive wrist pulse sensor based on the near-field variation of an array resonator. A compact resonator and its array were designed and fabricated on flexible substrate. The reflection coefficient of the resonator can vary as a function of the distance between the resonator and the walls of the major arteries, and the corresponding variation is utilized to obtain heart rate information at the wrist. To detect very weak pulse signals from the main arteries, a sensitivity enhancement technique was devised using a radio frequency (RF) array resonator. The sensor system was implemented with an RF switch to combine or select appropriate signals from the resonator element and was tested using the 2.4 GHz ISM band. The results demonstrated the sensor system's excellent performance in both sequential and simultaneous detection schemes. The measurement results showed that a heartbeat pulse can be detected from both radial and ulnar arteries via the array resonators. Considering the high sensitivity and characteristics, the proposed detection system can be utilized as a wearable, long-term health monitoring device.

Upon microbial infection, host immune cells recognize bacterial cell envelope components through cognate receptors. Although bacterial cell envelope components function as innate immune molecules, the role of the physical state of the bacterial cell envelope (i.e., particulate versus soluble) in host immune activation has not been clearly defined. Here, using two different forms of the staphylococcal cell envelope of Staphylococcus aureus RN4220 and USA300 LAC strains, we provide biochemical and immunological evidence that the particulate state is required for the effective activation of host innate immune responses. In a murine model of peritoneal infection, the particulate form of the staphylococcal cell envelope (PCE) induced the production of chemokine (C-X-C motif) ligand 1 (CXCL1) and CC chemokine ligand 2 (CCL2), the chemotactic cytokines for neutrophils and monocytes, respectively, resulting in a strong influx of the phagocytes into the peritoneal cavity. In contrast, compared with PCE, the soluble form of cell envelope (SCE), which was derived from PCE by treatment with cell wall-hydrolyzing enzymes, showed minimal activity. PCE also induced the secretion of calprotectin (myeloid-related protein 8/14 [MRP8/14] complex), a phagocyte-derived antimicrobial protein, into the peritoneal cavity at a much higher level than did SCE. The injected PCE particles were phagocytosed by the infiltrated neutrophils and monocytes and then delivered to mediastinal draining lymph nodes. More importantly, intraperitoneally (i.p.) injected PCE efficiently protected mice from S. aureus infection, which was abolished by the depletion of either monocytes/macrophages or neutrophils. This study demonstrated that the physical state of bacterial cells is a critical factor for efficient host immune activation and the protection of hosts from staphylococcal infections.

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In this paper,the sound intensity and airborne source quantification methods were used to estimate the airborne noise radiating from ag asoline direction injection engine and the relative contributions of each of the engine's components to such airborne noise. In order to estimate noise contribution using airborne source quantification, the sound volume velocity for the source should be estimated. In previous methods, the sound volume velocity wasestimated using the inverse method, whereas in this paper,the sound volume velocity is estimated directly. Forthis work, the sources of noise radiating from thegasoline direction injection engine were first identified by measuring the sound intensity of the noise sources while the engine wasrunning idle. The sound volume velocities of these sources were estimated from the product of the area of that noise source and the directly measured particle velocity.Inorder to validate this method, twospeakers with different frequencies were installed in an anechoic chamber and the contribution of each source wase stimated. Finally,t his proposed method wasa pplied to the identification and contribution of noise sources in agasoline direction injection engine.

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