A Circularly Polarized Spiral/Loop Antenna and Its Simple Feeding Mechanism

In this chapter, a simple spiral/loop antenna radiating circular polarization is introduced. Circularly polarized antennas are complex structures in general because they are constituted by two or more antennas in multilayer structures or employ phase-shifting circuits. For this reason, the circularly polarized antennas are too complex to be applied to mobile communication devices such as radiofrequency identifier (RFID) and global positioning system (GPS) handy terminals. Simpler and easier circularly polarized antennas are necessary for these devices. The presented circularly polarized antenna is so simple that it is printable, and it has only one port that can be fed through a coaxial cable directly. In the first section, the necessity of the circularly polarized antennas for modern antenna systems is explained. Then, the historical conventional antennas are introduced by referring to important publications. In the second section, the novel simple circularly polarized antenna invented by the author will be presented. The basic structure of the presented antenna and its principle will be explained. In the third section, a feeding mechanism to feed the presented antenna through a coaxial cable will be presented. In conclusion, detailed characteristics of the presented antennas will be summarized

Mechanical Stimulation-Induced Calcium Signaling by Piezo1 Channel Activation in Human Odontoblast Reduces Dentin Mineralization

Odontoblasts play critical roles in dentin formation and sensory transduction following stimuli on the dentin surface. Exogenous stimuli to the dentin surface elicit dentinal sensitivity through the movement of fluids in dentinal tubules, resulting in cellular deformation. Recently, Piezo1 channels have been implicated in mechanosensitive processes, as well as Ca(2+) signals in odontoblasts. However, in human odontoblasts, the cellular responses induced by mechanical stimulation, Piezo1 channel expression, and its pharmacological properties remain unclear. In the present study, we examined functional expression of the Piezo1 channel by recording direct mechanical stimulation-induced Ca(2+) signaling in dentin matrix protein 1 (DMP-1)-, nestin-, and dentin sialophosphoprotein (DSPP)-immunopositive human odontoblasts. Mechanical stimulation of human odontoblasts transiently increased intracellular free calcium concentration ([Ca(2+)](i)). Application of repeated mechanical stimulation to human odontoblasts resulted in repeated transient [Ca(2+)](i) increases, but did not show any desensitizing effects on [Ca(2+)](i) increases. We also observed a transient [Ca(2+)](i) increase in the neighboring odontoblasts to the stimulated cells during mechanical stimulation, showing a decrease in [Ca(2+)](i) with an increasing distance from the mechanically stimulated cells. Application of Yoda1 transiently increased [Ca(2+)](i). This increase was inhibited by application of Gd(3+) and Dooku1, respectively. Mechanical stimulation-induced [Ca(2+)](i) increase was also inhibited by application of Gd(3+) or Dooku1. When Piezo1 channels in human odontoblasts were knocked down by gene silencing with short hairpin RNA (shRNA), mechanical stimulation-induced [Ca(2+)](i) responses were almost completely abolished. Piezo1 channel knockdown attenuated the number of Piezo1-immunopositive cells in the immunofluorescence analysis, while no effects were observed in Piezo2-immunopositive cells. Alizarin red staining distinctly showed that pharmacological activation of Piezo1 channels by Yoda1 significantly suppressed mineralization, and shRNA-mediated knockdown of Piezo1 also significantly enhanced mineralization. These results suggest that mechanical stimulation predominantly activates intracellular Ca(2+) signaling via Piezo1 channel opening, rather than Piezo2 channels, and the Ca(2+) signal establishes intercellular odontoblast-odontoblast communication. In addition, Piezo1 channel activation participates in the reduction of dentinogenesis. Thus, the intracellular Ca(2+) signaling pathway mediated by Piezo1 channels could contribute to cellular function in human odontoblasts in two ways: (1) generating dentinal sensitivity and (2) suppressing physiological/reactional dentinogenesis, following cellular deformation induced by hydrodynamic forces inside dentinal tubules

Perturbed gap-filling synthesis in nucleotide excision repair causes histone H2AX phosphorylation in human quiescent cells

Human histone H2AX is rapidly phosphorylated on serine 139 in response to DNA double-strand breaks and plays a crucial role in tethering the factors involved in DNA repair and damage signaling. Replication stress caused by hydroxyurea or UV also initiates H2AX phosphorylation in S-phase cells, although UV induced H2AX phosphorylation in non-cycling cells has recently been observed. Here we study the UV induced H2AX phosphorylation in human primary fibroblasts under growth-arrested conditions. This reaction absolutely depends on nucleotide excision repair (NER) and is mechanistically distinct from the replication stress-induced phosphorylation. The treatment of cytosine-β-D-arabinofuranoside strikingly enhances the NER-dependent H2AX phosphorylation and induces the accumulation of replication protein A (RPA) and ATR-interacting protein (ATRIP) at locally UV-damaged subnuclear regions. Consistently, the phosphorylation appears to be mainly mediated by ataxia-telangiectasia mutated and Rad3-related (ATR), although Chk1 (Ser345) is not phosphorylated by the activated ATR. The cellular levels of DNA polymerases δ and ε and proliferating cell nuclear antigen are markedly reduced in quiescent cells. We propose a model that perturbed gap-filling synthesis following dual incision in NER generates single-strand DNA gaps and hence initiates H2AX phosphorylation by ATR with the aid of RPA and ATRIP

模擬授業を重視した情報科教育法の授業実践

情報科教育法の授業において、学習者は高校や大学で情報に関する授業を受けているものの、授業実践を前提に学んでいるわけではなく、授業のイメージが湧かないことが多いのが現状である。しかし、教育実習を控えた学習者にとって、情報科教育法は準備する上で不可欠な科目である。限られた時間のなかで、知識と高いコンピュータ技術の習得だけでなく、授業を実践する基本的な考え方を身につけさせるためには、授業方法を工夫する必要がある。実際に授業を設計・実施・評価できるようにするには、教員の指導のもとに学習者が授業を設計し、模擬授業を行ない、自己評価、他者評価を通して、学習者相互に良いところを吸収し、授業スキルを上げることが効果的と考えられる。本稿では模擬授業の実施方法に「自己と他者の比較から学ぶ」という工夫を加えた授業実践を報告する

Physical and functional interaction between DDB and XPA in nucleotide excision repair

Damaged DNA-binding protein (DDB), consisting of DDB1 and DDB2 subunits recognizes a wide spectrum of DNA lesions. DDB is dispensable for in vitro nucleotide excision repair (NER) reaction, but stimulates this reaction especially for cyclobutane pyrimidine dimer (CPD). Here we show that DDB directly interacts with XPA, one of core NER factors, mainly through DDB2 subunit and the amino-acid residues between 185 and 226 in XPA are important for the interaction. Interestingly, the point mutation causing the substitution from Arg-207 to Gly, which was previously identified in a XP-A revertant cell-line XP129, diminished the interaction with DDB in vitro and in vivo. In a defined system containing R207G mutant XPA and other core NER factors, DDB failed to stimulate the excision of CPD, although the mutant XPA was competent for the basal NER reaction. Moreover, in vivo experiments revealed that the mutant XPA is recruited to damaged DNA sites with much less efficiency compared with wild-type XPA and fails to support the enhancement of CPD repair by ectopic expression of DDB2 in SV40-transformed human cells. These results suggest that the physical interaction between DDB and XPA plays an important role in the DDB-mediated NER reaction

情報処理基礎における簡易演習補助システムの開発と実践

"これまでの四年間の情報教育の試行から演習における学習者,指導者,演習システムの間の情報の流れを考察し,その結果を情報教育の演習補助システムにまとめた。その構想の実践における有効性を評価するための当面の課題について具体的に述べた。そして将来の演習指導の展望についてまとめた。

授業支援システムを用いたプログラミング基礎教育の授業実践

大学のプログラミング基礎教育において修得させたい能力は、初歩的なプログラミング能力、課題内容に関して相談できるコミュニケーション能力、論理的思考能力、自己学習能力などである。これらの能力を持つ学習者が世間一般や産業界から求められていると考える。しかし、現状では、積極的に自分でプログラムを考えている学習者は少なく、プログラムの作成から実行までの操作ができれば満足している学習者が多く見受けられる。また、プログラミング初心者は、授業内容が進むにつれて、プログラムの構造が複雑になるため、途中で構造を作ることができなくなり、論理的思考を身につけるまでに至らないことが多い。教員が学習者の学習内容の理解度を把握し、理解度が低い内容は次回の授業に反映させて、つまづきをなくして次の内容に進む工夫が必要と考える。授業を受ける学習者は、高校の教科「情報」で教育をうけており、最低限の機器操作能力は持っているが、抽象的な数操作や概念理解の学習経験が少ないうえ、積極的に学習する心構えは希薄であり、授業活動を支援するシステムが必要となる。そこで、これまでの授業実践より、授業設計に役立つ知見を収集し、それらを組み合わせた授業支援システムを開発した。本稿では、2007年度に実施した授業支援システムを用いた授業実践について述べる

Demographic and Clinical Characteristics of Patients with Severe Asthma in the Asian Pacific Region : data from the International Severe Asthma Registry (ISAR)

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