準安定誘導体を用いたN-混乱ポルフィリンのπサーキットスイッチング

主1工学_物質創造工

π Circuit Switching of N-Confused Porphyrin using Metastable Derivatives

主1工学_物質創造工

Spectroscopic and Theoretical Studies of Acid–Base Behaviors of N‑Confused Porphyrins: Effects of <i>meso</i>-Aryl Substituents

The acid–base properties of a series of <i>meso</i>-aryl-substituted N-confused porphyrins (NCPs) were examined in aqueous sodium dodecyl sulfate (SDS) micellar solutions by both spectrophotometric methods and theoretical calculations. Reflecting the unsymmetrical structure of NCP having an outward-pointing pyrrolic nitrogen atom, the first and second protonations were distinguishable in the absorption and ¹H NMR spectra, unlike for porphyrins, and the p<i>K</i>₃ and p<i>K</i>₄ values were determined discretely. The individual basicities of the NCPs were directly related to the inductive effect of para substituents on the <i>meso</i>-phenyl groups: A linear relationship between the p<i>K</i>₃ (p<i>K</i>₄) and Hammett σ_para parameters was revealed. In the case of deprotonation, the structure of monoanionic NCP species was similarly characterized by the absorption and ¹H NMR spectra. For the second deprotonation, the p<i>K</i>₁ value was determined to be 11.39 for the NCP derivative with pentafluorophenyl groups. DFT calculations support the changes in electronic structures and aromaticity of the cationic and anionic species. It is demonstrated that NCPs are easily protonated and deprotonated compared to the corresponding regular congeners

The role of initial neck dissection for patients with node-positive oropharyngeal squamous cell carcinomas

Background: The current study sought to assess the role of initial neck dissection (ND) for patients with node-positive oropharyngeal squamous cell carcinomas (OPSCC). Methods: The data for 202 patients with previously untreated node-positive OPSCC were gathered from 12 institutions belonging to the Head and Neck Cancer Study Group in the Japan Clinical Oncology Group. These patients were categorized into two groups, consisting of the initial ND group and the wait-and-see group, according to treatment policy. Results: Regional recurrence was observed in 17 of 93 patients undergoing initial ND, whereas, recurrent or persistent diseases were observed in 40 of 109 patients who did not undergo initial ND. The 4-year overall survival rates (OS) for the wait-and-see group and initial ND groups were 74.0% and 78.7%, respectively, and the 4-year regional control rates (RC) for each group were 77.6% and 84.9%. There were no significant differences in either OS or RC (p = 0.3440 and p = 0.2382, respectively). However, for patients with N3 disease, the 4-year OS of the initial ND group (100%) was favorable. For patients with N2a disease, the 4-year RC of the initial ND group was higher than that of the wait-and-see group statistically (100% vs 62.5%, p = 0.0156). Conclusions: The role of initial ND was limited in patients with node-positive OPSCC. The treatment strategy not involving initial ND is considered feasible and acceptable when nodal evaluation after definitive radiotherapy or chemoradiotherapy is applied adequately. However, it is possible that initial ND improves outcomes in patients with resectable large-volume nodal disease. (C) 2014 Elsevier Ltd. All rights reserved

Multi-institutional retrospective study for the evaluation of ocular function-preservation rates in maxillary sinus squamous cell carcinomas with orbital invasion

Background. This study aimed to evaluate ocular function and survival rates among treatment modalities in patients with maxillary sinus cancer with orbital invasion. Methods. Eighty-seven patients were classified according to the main treatment modality. Ocular function preservation rates and survival rates were evaluated for each therapeutic modality. Results. The 5-year overall survival rate for the en bloc resection, conservative surgery, superselective intra-arterial chemotherapy and radiotherapy (RADPLAT), intra-venous chemoradiotherapy (IV-CRT) was 70%, 35%, 49%, and 31%, respectively. Ocular function preservation rate for each group was 15%, 27%, 30%, and 17%, respectively. In the en bloc resection group, there was no significant difference in the 5-year overall survival rate between patients with orbital exenteration and those without orbital exenteration (72% vs 71%, p=0.9321). Conclusions. The en bloc resection group showed a favorable survival rate, but a low preservation rate. Preservation of orbital contents did not reduce the survival rate

Tautomerism-Induced Cis–Trans Isomerization of Pyridylethenyl N-Confused Porphyrin

Pyridylethenyl-substituted N-confused porphyrins (NCPs) were synthesized, and their cis–trans isomerization was studied. Among four possible isomers, trans-3H and cis-2H types of structures, of which aromaticity and absorption/emission properties differ largely, were isolated. The cis-isomer was largely stabilized by the intramolecular hydrogen bonding between the pyrrolic-NH and the pyridinic-N in the vicinity. The thermal cis–trans isomerization proceeded even at 30 °C, which was significantly accelerated by the pyridine added to the system. The kinetic studies revealed that the isomerization reaction was second-order and the activation energy of the thermal isomerization from cis to trans isomer was ΔG0⧧cis→trans = 35.7 kcal/mol at 298 K, which is significantly smaller than that of Ni complex (42.3 kcal/mol). An intermolecular proton transfer induced cis–trans isomerization mechanism was proposed.by Ryuichi Sakashita, Yasutaka Oka, Hisanori Akimaru, Praseetha E. Kesavan, Masatoshi Ishida, Motoki Toganoh, Tomoya Ishizuka, Shigeki Mori and Hiroyuki Furut

Influence of light exposure at nighttime on sleep development and body growth of preterm infants

Previous studies have demonstrated that a light-dark cycle has promoted better sleep development and weight gain in preterm infants than constant light or constant darkness. However, it was unknown whether brief light exposure at night for medical treatment and nursing care would compromise the benefits brought about by such a light-dark cycle. To examine such possibility, we developed a special red LED light with a wavelength of > 675 nm which preterm infants cannot perceive. Preterm infants born at < 36 weeks' gestational age were randomly assigned for periodic exposure to either white or red LED light at night in a light-dark cycle after transfer from the Neonatal Intensive Care Unit to the Growing Care Unit, used for supporting infants as they mature. Activity, nighttime crying and body weight were continuously monitored from enrolment until discharge. No significant difference in restactivity patterns, nighttime crying, or weight gain was observed between control and experimental groups. The data indicate that nursing care conducted at 3 to 4-hour intervals exposing infants to light for < 15 minutes does not prevent the infants from developing circadian rest-activity patterns, or proper body growth as long as the infants are exposed to regular light-dark cycles

Extracting interpretable features for pathologists using weakly supervised learning to predict p16 expression in oropharyngeal cancer

Abstract One drawback of existing artificial intelligence (AI)-based histopathological prediction models is the lack of interpretability. The objective of this study is to extract p16-positive oropharyngeal squamous cell carcinoma (OPSCC) features in a form that can be interpreted by pathologists using AI model. We constructed a model for predicting p16 expression using a dataset of whole-slide images from 114 OPSCC biopsy cases. We used the clustering-constrained attention-based multiple-instance learning (CLAM) model, a weakly supervised learning approach. To improve performance, we incorporated tumor annotation into the model (Annot-CLAM) and achieved the mean area under the receiver operating characteristic curve of 0.905. Utilizing the image patches on which the model focused, we examined the features of model interest via histopathologic morphological analysis and cycle-consistent adversarial network (CycleGAN) image translation. The histopathologic morphological analysis evaluated the histopathological characteristics of image patches, revealing significant differences in the numbers of nuclei, the perimeters of the nuclei, and the intercellular bridges between p16-negative and p16-positive image patches. By using the CycleGAN-converted images, we confirmed that the sizes and densities of nuclei are significantly converted. This novel approach improves interpretability in histopathological morphology-based AI models and contributes to the advancement of clinically valuable histopathological morphological features