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1.
J Chem Phys ; 153(10): 104305, 2020 Sep 14.
Article in English | MEDLINE | ID: mdl-32933300

ABSTRACT

To investigate microscopic characters of Si-H⋯H-O type dihydrogen bonds, we observed OH and SiH stretch bands in both the S0 and S1 states of phenol-ethyldimethylsilane (PhOH-EDMS) clusters by infrared (IR)-ultraviolet (UV) and UV-IR double resonance spectroscopies. Density functional theory (DFT) calculations and energy decomposition analysis were also performed. Structures of two isomers identified were unambiguously determined through the analysis of IR spectra and DFT calculations. To discuss the strength of dihydrogen bond in various systems, we performed theoretical calculations on clusters of EDMS with several acidic molecules in addition to PhOH. It was revealed that charge-transfer interaction energies from a bonding σ orbital of SiH bond to an anti-bonding σ* orbital of OH bond well reflect strengths of dihydrogen bonds. Additionally, it was found that the red shift of SiH stretch frequencies can be used as a crude measure of the strength of dihydrogen bonds. Relationship between the red shifts of OH/SiH stretch frequencies and various electrostatic components of the interaction energy was examined. In the S1 state, large increases in red shifts were observed for both the OH and SiH stretch frequencies. Since the EDMS moiety is not associated with the electronic excitation in a cluster, the strength of dihydrogen bonds in the S1 and S0 states was able to be directly compared based on the red shifts of the SiH stretch bands. A significant increase in the red shift of SiH stretch frequency indicates a strengthening of the dihydrogen bonds during the electronic excitation of the PhOH moiety.

2.
J Chem Phys ; 152(19): 194306, 2020 May 21.
Article in English | MEDLINE | ID: mdl-33687225

ABSTRACT

Infrared (IR) spectra in a region of the OH stretch band of phenol (PhOH)-ethyldimethylsilane (EDMS), phenol (PhOH)-triethylsilane (TES), and phenol (PhOH)-t-butyldimethylsilane (BDMS) dihydrogen-bonded clusters in the S1 state were observed. All of the species exhibited unconventional band patterns in which many combination bands appeared with comparable intensities to those of allowed bands. Such a behavior is sometimes called a Franck-Condon-like pattern. In the case of the PhOH-BDMS, one intermolecular vibrational mode is involved in this behavior. The observed IR spectra were well reproduced based on the concept of the Franck-Condon-like behavior. As an alternative treatment, we analyzed the band patterns on the concept of intensity borrowing due to the vibrational anharmonic interaction. The analysis was based on an effective Hamiltonian involving an anharmonic interaction between the OH stretch and intermolecular vibrational modes. Two treatments provided the same results. Thus, it was confirmed that the Franck-Condon-like behavior originates from vibrational anharmonic interactions. In the cases of the PhOH-EDMS and PhOH-TES, we carried out a two-dimensional Franck-Condon and an effective Hamiltonian analysis to interpret the Franck-Condon-like patterns. We examined vibrational wave functions obtained by the latter analysis. Shapes of the wave functions suggest that a recombination of the intermolecular vibrational modes occurs during the excitation of OH stretch mode in these clusters, which is a similar behavior to the Duschinsky effect in the electronic transition.

3.
Foods ; 7(11)2018 Oct 25.
Article in English | MEDLINE | ID: mdl-30366388

ABSTRACT

In most cases, a meal cannot be finished with a single bite and sip. During eating and drinking, consumers receive dynamic food perceptions from sensory attributes in foods. Thus, we performed multi-sip time⁻intensity (TI) evaluation of sensory attribute. In each of ten trials, the participant evaluated continuously the intensity of retronasal aroma for 60 s after swallowing oolong tea. We compared the TI parameters (Imax: maximum intensity, Tmax: time point at which intensity reached the maximum value, AUC: area under the TI curve, Dplateau: duration between the first and last time points with values exceeding 90% of the maximum intensity, Rinc: rate of intensity increase between the first time points with values exceeding 5% and 90% of the maximum intensity, and Rdec: rate of intensity decrease between the last time points with values exceeding 5% and 90% of the maximum intensity) and TI curves among the ten trials, and approximated each TI curve with an exponential model. Some TI parameters (Imax, Tmax, AUC, and Rinc) differed significantly between the first and subsequent trials. The TI curve was significantly lower in the first trial than in the subsequent trials, and TI curve during the time from starting the evaluation to reaching maximum intensity was significantly lower in the second trial than in the subsequent trials. The time constant of the fitted exponential function revealed that the decay of retronasal aroma intensity was slightly faster in the second through fourth trials than in the first and the fifth through tenth trials. These results indicate that olfaction might be more perceptive while consumers sip a cup of the beverage.

4.
Surg Today ; 44(11): 2157-61, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24407283

ABSTRACT

Measuring tumor marker levels following cancer treatment can be useful. Although serum thyroglobulin is a useful marker after total thyroidectomy for papillary thyroid carcinoma (PTC), it is not a reliable marker for patients with a high titer of anti-thyroglobulin antibodies or when transformation to undifferentiated carcinoma has occurred. The female patient in this case report underwent total thyroidectomy and oral I-131 therapy for PTC at the age of 47 years, followed by cervical lymph node and lung resections for metastases, 3 and 11 years later, respectively. She also received oral I-131 therapy and external beam radiotherapy for mediastinal lymph node metastases. The lymphadenopathy lesions progressed and multiple lung metastases were detected when she was 61 years of age. She died at the age of 62 years. The serum CA19-9 level had gradually increased in association with enlargement of the recurrent lesions and immunostaining of CA19-9 in the pulmonary metastasis was intense. Thus, we consider that measuring the level of serum CA19-9 is an effective tool for evaluating disease status after surgery for PTC.


Subject(s)
CA-19-9 Antigen/biosynthesis , Carcinoma, Papillary/diagnosis , Carcinoma, Papillary/secondary , Lung Neoplasms/diagnosis , Lung Neoplasms/secondary , Thyroid Neoplasms/pathology , Thyroid Neoplasms/surgery , Biomarkers, Tumor/analysis , Biomarkers, Tumor/blood , CA-19-9 Antigen/analysis , CA-19-9 Antigen/blood , Carcinoma, Papillary/metabolism , Fatal Outcome , Female , Humans , Iodine Radioisotopes/therapeutic use , Lung Neoplasms/metabolism , Lymph Node Excision , Lymphatic Metastasis , Mediastinum , Middle Aged , Radiopharmaceuticals/therapeutic use , Thyroidectomy
5.
Clin J Gastroenterol ; 3(6): 289-95, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21841958

ABSTRACT

Metastasis from a malignant tumor to the palatine tonsils is rare, with only 100 cases reported in the English-language literature. Tonsillar metastasis from a gastric cancer is very rare. We report here a case of palatine tonsillar metastasis after gastric cancer surgery. The patient was an 88-year-old woman who had gastric cancer with abdominal wall invasion. She had undergone a distal gastrectomy with abdominal wall resection and D2 lymph node dissection. Histologically, the tumor was primarily a moderately differentiated adenocarcinoma. It was stage IV (T4, N1, M0) using TNM clinical classification. The patient developed pharyngeal discomfort and abdominal pain and was hospitalized during the follow-up period, 1 year 9 months post-operatively. Multiple lung metastases, Virchow's lymph node metastasis, and adrenal metastasis were observed. A mass of 2.5 cm was also observed in the right palatine tonsil. It was diagnosed as a moderately differentiated adenocarcinoma, a metastasis from gastric cancer. There was a concern of asphyxiation due to hemorrhage of the tumor; however, the tumor dislodged approximately 10 days after biopsy and tonsillar recurrence was not observed. The patient died 1 year 10 months post-operatively. In the literature there are cases with tonsillar metastases where surgical treatment, radiotherapy, and chemotherapy were performed and extension of survival was seen. Tonsillar metastasis is a form of systemic metastasis of a malignant tumor, and there is a high risk for asphyxiation from tumor dislodgement or hemorrhage. Thus, it is important to recognize tonsillar metastasis as an oncologic emergency.

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