Laser-induced microexplosion confined in a bulk of silica: formation of nanovoids

We report on the nanovoid formation inside synthetic silica, viosil, by single femtosecond pulses of 30–100nJ energy, 800nm wavelength, and 180fs duration. It is demonstrated that the void is formed as a result of shock and rarefaction waves at pulse power much lower than the threshold of self-focusing. The shock-compressed region around the nanovoid is demonstrated to have higher chemical reactivity. This was used to reveal the extent of the shock-compressed region by wet etching. Application potential of nanostructuring of dielectrics is discussed

Impact of the Student Doctor Ceremony and Receiving a White Coat Before Clinical Clerkship Among Medical Students

The first white coat ceremony took place at a Japanese medical school in 2001 and was designed to reaffirm the responsibilities of medical students becoming student doctors（SDs）prior to their clinical clerkships. Dokkyo Medical University has been holding an SD ceremony, rather than a white coat ceremony, since March of 2014. White coats adorned with the school emblem and students’ names were distributed to students after the SD ceremony for the first time in 2018. Using an anonymous questionnaire, this study examined changes in the students’ moods before and after the SD ceremony as well as their impressions of the white coat.Of 115 responses, 106 with valid data were analyzed. The mean age was 23.44 years. The results indicated that students felt more cheerful, nervous, motivated, hopeful, steadfast, active, and restless after the ceremony than before, with 79.2％ of the students reporting a favorable opinion of the white coat adorned with the school’s emblem. Additionally, the top three meanings associated with the white coat were cleanliness, uniform, and propriety.This study revealed the impact of the SD ceremony and the meanings of the white coat among medical students. Both the SD ceremony and white coat ceremony are worthy of future examination

Oculomotor Nerve Palsy following Cardiac Tamponade with Churg-Strauss Syndrome: A Case Report

A 57-year-old man with a history of more than 10 years of bronchial asthma and chronic sinusitis complained of double vision which developed 18 days after cardiac tamponade with eosinophil-rich fluid (eosinophils 30%). He had oculomotor nerve palsy, and a blood test revealed eosinophilia (12,700/mm3) and elevation of both C-reactive protein and rheumatoid factor. He was diagnosed as having Churg-Strauss syndrome. His symptoms were relieved by corticosteroid therapy. Our case and previous cases in the literature revealed that oculomotor nerve palsy in Churg-Strauss syndrome is associated with pupil involvement and may be relieved by corticosteroid treatment

Coupling Between B Cell Receptor and Phospholipase C-γ2 Is Essential for Mature B Cell Development

Two signaling pathways known to be essential for progression from immature to mature B cells are BAFF receptor (BAFF-R) and the B cell receptor (BCR). Here, we first show that phospholipase C (PLC)-γ2 is required for a BAFF-R–mediated survival signal. Then, we have examined the question of whether the reduced number of mature B cells in PLC-γ2−/− mice is caused by a defect in either BCR or BAFF-R signaling. We find that a PLC-γ2 SH2 mutant, which inhibits coupling between BCR and PLC-γ2, fails to restore B cell maturation, despite supporting BAFF-dependent survival. Therefore, our data suggest that the BAFF-R–mediated survival signal, provided by PLC-γ2, is not sufficient to promote B cell maturation, and that, in addition, activation of PLC-γ2 by BCR is required for B cell development

Syndiotactic- and heterotactic-specific radical polymerization of N-n-propylmethacrylamide complexed with alkali metal ions

We investigated the radical polymerization of N-n-propylmethacrylamide (NNPMAAm) in the presence of alkali metal bis(trifluoromethanesulfonyl)imides (MNTf2), in particular LiNTf2. The addition of MNTf2 led to a significant improvement in the yield and molecular weight of the resulting poly(NNPMAAm)s. Furthermore, the solvent employed influenced stereospecificity in the presence of LiNTf2. The stoichiometry of the NNPMAAm–Li+ complex appeared to be critical to determining the stereospecificity in the NNPMAAm polymerization. The 1:1-complexed monomer in protic polar solvents provided syndiotactic-rich polymers, whereas the 2:1-complexed monomer in aprotic solvents gave heterotactic-rich polymers. Stereochemical analyses revealed that m-addition by an r-ended radical was the key step in the induction of heterotactic specificity in the aprotic solvents. Spectroscopic analyses suggested that the Li+ cation played a dual role in the polymerization process, with Li+ stabilizing the propagating radical species and also activating the incoming monomer. Kinetic studies with the aid of electron spin resonance spectroscopy revealed that the addition of LiNTf2 caused a significant increase in the kp value and a decrease in the kt value. The stereoregularity of poly(NNPMAAm)s was found to influence the phase transition behavior of their aqueous solutions. In a series of syndiotactic-rich polymers, the phase-transition temperature decreased gradually with increase in rr triad content. Furthermore, heterotactic-rich poly(NNPMAAm) exhibited high hysteresis, which increased in magnitude with increasing mr triad content

Long-range heteronuclear J-coupling constants in esters: Implications for 13C metabolic MRI by side-arm parahydrogen-induced polarization

Side-arm parahydrogen induced polarization (PHIP-SAH) presents a cost-effective method for hyperpolarization of 13C metabolites (e.g. acetate, pyruvate) for metabolic MRI. The timing and efficiency of typical spin order transfer methods including magnetic field cycling and tailored RF pulse sequences crucially depends on the heteronuclear J coupling network between nascent parahydrogen protons and 13C, post-parahydrogenation of the target compound. In this work, heteronuclear nJHC (1 < n ≤ 5) couplings of acetate and pyruvate esters pertinent for PHIP-SAH were investigated experimentally using selective HSQMBC-based pulse sequences and numerically using DFT simulations. The CLIP-HSQMBC technique was used to quantify 2/3-bond JHC couplings, and 4/5-bond JHC ≲ 0.5 Hz were estimated by the sel-HSQMBC-TOCSY approach. Experimental and numerical (DFT-simulated) nJHC couplings were strongly correlated (P < 0.001). Implications for 13C hyperpolarization by magnetic field cycling, and PH-INEPT and ESOTHERIC type spin order transfer methods for PHIP-SAH were assessed, and the influence of direct nascent parahydrogen proton to 13C coupling when compared with indirect homonuclear TOCSY-type transfer through intermediate (non-nascent parahydrogen) protons was studied by the density matrix approach

Improvement of convergence and stability in moving object extraction by the level set method

金沢大学理工研究域電子情報学系Semantic object extraction from a video sequence is an indispensable technique in new content-based applications, such as in the international standards MPEG-4 and MPEG- 7. In the present paper, we propose a technique that extracts the shape of moving objects from a video sequence with a stationary background by the level set method. In the proposed method, two concepts are incorporated into a novel speed function of the level set method in order to improve convergence and stability. The first concept is the object map, which represents the outline of object regions and the background. The speed function is changed using the object map in order to improve convergence. The second concept is the contour potential energy, which represents the energy in the direction of an object\u27s contour. The efficiency of the proposed method for moving object extraction is demonstrated through computer simulations

Improvement of convergence and stability in moving object extraction by the level set method

金沢大学理工研究域電子情報学系Semantic object extraction from a video sequence is an indispensable technique in new content-based applications, such as in the international standards MPEG-4 and MPEG- 7. In the present paper, we propose a technique that extracts the shape of moving objects from a video sequence with a stationary background by the level set method. In the proposed method, two concepts are incorporated into a novel speed function of the level set method in order to improve convergence and stability. The first concept is the object map, which represents the outline of object regions and the background. The speed function is changed using the object map in order to improve convergence. The second concept is the contour potential energy, which represents the energy in the direction of an object\u27s contour. The efficiency of the proposed method for moving object extraction is demonstrated through computer simulations

Requirement for Ras Guanine Nucleotide Releasing Protein 3 in Coupling Phospholipase C-γ2 to Ras in B Cell Receptor Signaling

Two important Ras guanine nucleotide exchange factors, Son of sevenless (Sos) and Ras guanine nucleotide releasing protein (RasGRP), have been implicated in controlling Ras activation when cell surface receptors are stimulated. To address the specificity or redundancy of these exchange factors, we have generated Sos1/Sos2 double- or RasGRP3-deficient B cell lines and determined their ability to mediate Ras activation upon B cell receptor (BCR) stimulation. The BCR requires RasGRP3; in contrast, epidermal growth factor receptor is dependent on Sos1 and Sos2. Furthermore, we show that BCR-induced recruitment of RasGRP3 to the membrane and the subsequent Ras activation are significantly attenuated in phospholipase C-γ2–deficient B cells. This defective Ras activation is suppressed by the expression of RasGRP3 as a membrane-attached form, suggesting that phospholipase C-γ2 regulates RasGRP3 localization and thereby Ras activation