Robust Pixel Design Methodologies for a Vertical Avalanche Photodiode (VAPD)-Based CMOS Image Sensor.

We present robust pixel design methodologies for a vertical avalanche photodiode-based CMOS image sensor, taking account of three critical practical factors: (i) "guard-ring-free" pixel isolation layout, (ii) device characteristics "insensitive" to applied voltage and temperature, and (iii) stable operation subject to intense light exposure. The "guard-ring-free" pixel design is established by resolving the tradeoff relationship between electric field concentration and pixel isolation. The effectiveness of the optimization strategy is validated both by simulation and experiment. To realize insensitivity to voltage and temperature variations, a global feedback resistor is shown to effectively suppress variations in device characteristics such as photon detection efficiency and dark count rate. An in-pixel overflow transistor is also introduced to enhance the resistance to strong illumination. The robustness of the fabricated VAPD-CIS is verified by characterization of 122 different chips and through a high-temperature and intense-light-illumination operation test with 5 chips, conducted at 125 °C for 1000 h subject to 940 nm light exposure equivalent to 10 kLux.

A 250 m Direct Time-of-Flight Ranging System Based on a Synthesis of Sub-Ranging Images and a Vertical Avalanche Photo-Diodes (VAPD) CMOS Image Sensor.

We have developed a direct time-of-flight (TOF) 250 m ranging Complementary Metal Oxide Semiconductor (CMOS) image sensor (CIS) based on a 688 × 384 pixels array of vertical avalanche photodiodes (VAPD). Each pixel of the CIS comprises VAPD with a standard four transistor pixel circuit equipped with an analogue capacitor to accumulate or count avalanche pulses. High power near infrared (NIR) short (<50 ns) and repetitive (6 kHz) laser pulses are illuminated through a diffusing optics. By globally gating the VAPD, each pulse is counted in the in-pixel counter enabling extraction of sub-photon level signal. Depth map imaging with a 10 cm lateral resolution is realized from 1 m to 250 m range by synthesizing subranges images of photon counts. Advantages and limitation of an in-pixel circuit are described. The developed CIS is expected to supersede insufficient resolution of the conventional light detection and ranging (LiDAR) systems and the short range of indirect CIS TOF.

[Mechanism of action of antiviral drugs].

Antiviral therapy is now one of routine practices and as common as chemotherapy against bacterial infection. Therefore it is important for the clinicians to understand the differences between bacterial and viral infections in order to use antiviral drugs properly. This review focuses the difference of the mechanism of action of antiviral drugs and antibiotics and the importance of host immune status to recover from microbial infection.

Different immunohistochemical localization for TMEM16A and CFTR in acinar and ductal cells of rat major salivary glands and exocrine pancreas.

We investigated the mRNA expression and immunohistochemical localization of Cl- channels, transmembrane member 16A (TMEM16A or anoctamin 1), and cystic fibrosis transmembrane conductance regulator (CFTR) in rat major salivary glands and exocrine pancreas. RT-PCR detected mRNA expression of TMEM16A and CFTR in the extracts of the parotid gland (PG), submandibular gland (SMG), sublingual gland (SLG), and pancreas. Immunoreactivity for TMEM16A was localized in the apical membrane of serous acinar and intercalated ductal cells in the PG and SMG as well as mucous acinar cells in the SLG; however, it was not detected in striated ductal cells of these tissues. Although striated ductal cells in the PG, SMG and SLG, and granular ductal cells in the SMG, were immunoreactive for CFTR in the luminal side, serous, mucous acinar, and intercalated ductal cells were not immunoreactive for CFTR in any of the major salivary glands. In the exocrine pancreas, immunoreactivity for TMEM16A was localized in the apical membrane of acinar cells, while immunoreactivity for CFTR was localized in the luminal side of intercalated ductal cells. These results suggest that different localization of TMEM16A and CFTR immunoreactivities reflects the respective functions of acinar and ductal cells in major salivary glands and exocrine pancreas.

[Intraluminal ureteral hematoma complicating anticoagulant therapy].

Intraluminal ureteral hematoma is a rare disease and only a few cases have been previously described. We report a case of intraluminal ureteral hematoma induced by anticoagulant therapy. A 65-year old man having the oral anticoagulant therapy for prevention of secondary thrombolism following atrial fibrillation was referred to us for gross hematuria. Ultrasound sonography (US) revealed right renal mild wide pelvis. Computed tomography (CT) showed the right ureteral submucosal hematoma. This ureteral hematoma penetrated the ureteral mucosa and caused macrohematuria. The patient had been anticoagulated on Warfarin with Bucolome for 18 days, so the prothrombin times (PT) was found to be excessively prolonged beyond the normal therapeutic range. The oral anticoagulation was stopped and intravenous Vitamin K2 was given, so PT was normalized. Though estimate hemorrhage quantity reached 1,200 ml, we had no blood transfusion. The hematoma was completely diminished 4 months later, no reccurence has been occurred. Bucolome has especially pharmacokinetic positive interaction to Warfarin, so we must check PT-INR frequently.