173 research outputs found

    Spectroscopic evidence of phase transition of monomolecular water in solid polystyrene.

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    Phase transition behavior of monomolecular water in solid polystyrene was examined by temperature variable Fourier transform infrared spectroscopy. Spectral changes showed for the first time that monomolecular water in a polymer matrix (in a closed system) could be condensed and then frozen and also that the ice formed could be grown and diminished by vapor deposition in cooling process and sublimation in heating process, respectively

    Recrystallization of water in non-water-soluble (meth)acrylate polymers is not rare and is not devitrification.

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    Change in the state of water sorbed into four kinds of non-water-soluble poly(meth)acrylates with low water content by temperature (T) perturbation was examined on the basis of T variable mid-infrared (MIR) spectroscopy. Many studies using differential scanning calorimetry suggested that there was no change in the state. T dependence of their MIR spectra, however, clearly demonstrated various changes in the state. Furthermore, recrystallization, which was crystallization during heating, was observed in all four polymers. The recrystallization observed in this study was not devitrification, which is the change in the state from glassy water to crystalline water, but vapor deposition during heating (vapor re-deposition). There were only two reports about recrystallization of water in a non-water-soluble polymer before this report; therefore, it might be considered to be a rare phenomenon. However, as demonstrated in this study, it is not a rare phenomenon. Recrystallization (vapor re-deposition) of water in the polymer matrices is related to a balance between flexibility and strength of the electrostatic interaction sites of polymer matrices but might not be related to the biocompatibility of polymers

    Mid-infrared spectroscopic investigation of the perfect vitrification of poly(ethylene glycol) aqueous solutions.

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    Crystallization/recrystallization behaviors of poly(ethylene glycol) (PEG) aqueous solutions with water contents (WC\u27s) of ∼36-51 wt % were investigated by temperature-variable mid-infrared spectroscopy. At a WC of 43.2 wt %, crystallization and recrystallization of water and PEG were not observed. At this specific WC value (WCPV), perfect vitrification occurred. Below and above the WCPV value, crystallization/recrystallization behaviors changed drastically. The crystallization temperature below WCPV (237 K) was ∼10 K greater than that above WCPV (226 K). Recrystallization above and below WCPV occurred in one (213 K) and two (198 and 210 K) steps, respectively. These findings resulted from the difference in the (re)crystallization behaviors of water molecules associated with PEG chains with helical and random-coil conformations. These two types of water molecules might have limiting concentrations for their (re)crystallization, indicating that perfect vitrification might have occurred when the concentrations of the two types of water molecules were less than the limiting concentrations of their (re)crystallization

    Two-step recrystallization of water in concentrated aqueous solution of poly(ethylene glycol).

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    Crystallization behavior of water in a concentrated aqueous solution of poly(ethylene glycol) (PEG) with a water content of 37.5 wt % was investigated by temperature variable mid-infrared (mid-IR) spectroscopy in a temperature range of 298-170 K. The mid-IR spectrum of water at 298 K showed that a large water cluster was not formed and that most of the water molecules were associated with the PEG chain. Ice formation, however, occurred as found in previous studies by differential scanning calorimetory. Ice formations were grouped into three types: crystallization at 231 K during cooling, that at 198 K during heating, and that at 210 K during heating. The latter two were just recrystallization. These ice formations were the direct transition from hydration species to ice without condensation regardless of crystallization or recrystallization. This means that the recrystallized water in the present system was not generated from low-density amorphous solid water. At a low cooling rate, nearly complete crystallization at 231 K during cooling and no recrystallization were observed. At a high cooling rate, no crystallization and two-step recrystallization at 198 and 210 K were observed. The former and latter recrystallizations were found to be generated from water associated with the PEG chains with ttg (the sequence -O-CH(2)-CH(2)-O- having a trans (t) conformation about the -C-O- bond and a gauche (g) conformation about the -C-C- bond) and random conformations, respectively. These results indicate that recrystallizable water does not have a single specific water structure

    Diffusion-Controlled Recrystallization of Water Sorbed into Poly(meth)acrylates Revealed by Variable-Temperature Mid-Infrared Spectroscopy and Molecular Dynamics Simulation.

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    Recrystallization behaviors of water sorbed into four poly(meth)acrylates, poly(2-methoxyethyl acrylate), poly(tetrahydrofurfuryl acrylate), poly(methyl acrylate), and poly(methyl methacrylate), are investigated by variable-temperature mid-infrared (VT-MIR) spectroscopy and molecular dynamics (MD) simulation. VT-MIR spectra demonstrate that recrystallization temperatures of water sorbed into the polymers are positively correlated with their glass-transition temperatures reported previously. The present MD simulation shows that a lower-limit temperature of the diffusion for the sorbed water and the glass-transition temperatures of the polymers also have a positive correlation, indicating that the recrystallization is controlled by diffusion mechanism rather than reorientation mechanism. Detailed molecular processes of not only recrystallization during rewarming but also crystallization during cooling and hydrogen-bonding states of water in the polymers are systematically analyzed and discussed

    Tumour blood vessel normalisation by prolyl hydroxylase inhibitor repaired sensitivity to chemotherapy in a tumour mouse model

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    Blood vessels are important tissue structures that deliver oxygen and nutrition. In tumour tissue, abnormal blood vessels, which are hyperpermeable and immature, are often formed; these tissues also have irregular vascularisation and intravasation. This situation leads to hypoperfusion in tumour tissue along with low oxygen and nutrition depletion; this is also called the tumour microenvironment and is characterised by hypoxia, depleted nutrition, low pH and high interstitial pressure. This environment induces resistance to anticancer drugs, which causes an increase in anticancer drug doses, leading to increased side effects. We hypothesised that normalised tumour blood vessels would improve tumour tissue perfusion, resupply nutrition and re-oxygenate the tumour tissue. Chemotherapy would then be more effective and cause a decrease in anticancer drug doses. Here we report a neovascularisation-inducing drug that improved tumour vascular abnormalities, such as low blood flow, blood leakage and abnormal vessel structure. These results could lead to not only an increased chemo-sensitivity and tissue-drug distribution but also an up-regulated efficiency for cancer chemotherapy. This suggests that tumour blood vessel normalisation therapy accompanied by angiogenesis may be a novel strategy for cancer therapy

    Immunohistochemical Features of Primary Pure Squamous Cell Carcinoma in the Thyroid: An Autopsy Case

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    Primary squamous cell carcinoma (SCC) in the thyroid is extremely rare and has been reported in < 1% of all thyroid cancer cases. Primary SCC in the thyroid was thought to be a transitional form derived from adenocarcinomas; therefore, the majority of reported cases have focused on the conjunction with other histological adenocarcinomas. A 73-year-old male presented to our hospital with bilateral vocal fold palsy and an anterior neck mass. Ultrasound sonography revealed a bulky tumor in the thyroid and bilateral cervical lymphadenopathy. We performed fine-needle aspiration cytology from the thyroid tumor, which revealed SCC. Positron emission tomography/computed tomography showed distant metastases in the lungs, mediastinal lymph nodes, and vertebra. We diagnosed the patient as having stage IVC SCC in the thyroid and administered weekly paclitaxel. Four and a half months after treatment initiation, the tumor progression resulted in aspiration pneumonia, which proved fatal. We performed an autopsy in accordance with the patient’s wishes. Pathological findings revealed that all carcinomas in the thyroid, cervical lymph nodes, and lungs were pure SCCs. Immunohistochemical examinations for PAX8, thyroglobulin, and TTF-1 were all negative. Differentiated thyroid carcinomas have 3 major positive markers – PAX8, thyroglobulin, and TTF-1 –, and PAX8 is also sometimes positive for SCC in the thyroid. PAX8 positivity of SCC in the thyroid might, however, be associated with conjunction with other histological adenocarcinomas such as papillary or follicular thyroid carcinoma; therefore, pure SCC in the thyroid might be negative for PAX8

    Bortezomib-cyclophosphamide-dexamethasone induction/consolidation and bortezomib maintenance for transplant-eligible newly diagnosed multiple myeloma: phase 2 multicenter trial

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    [Objectives:] We conducted a phase II trial to prospectively evaluate the efficacy and safety of bortezomib-cyclophosphamide-dexamethasone (VCD) induction, autologous stem cell transplantation (ASCT), VCD consolidation, and bortezomib maintenance in transplant-eligible newly diagnosed multiple myeloma (NDMM) patients in Japan (UMIN000010542). [Methods:] From 2013 to 2016, 42 patients with a median age of 58 (range 42–65) years with NDMM were enrolled in 15 centers. The primary endpoint was the complete response (CR) /stringent CR (sCR) rate after transplantation, and overall/progression-free survival rates were also evaluated. [Results:] Following induction therapy, the overall response rate was obtained in 71% of patients, including a CR/sCR of 10% and a very good partial response (VGPR) of 26%. Twenty-six of the 42 patients completed ASCT following the protocol and CR/sCR and VGPR rate 100 days after ASCT was 26% and 17%, respectively. During consolidation therapy, 3 of the 24 patients achieved deeper responses. Eight of the 18 patients completed 2-year bortezomib maintenance without disease progression and grade 3/4 toxicities. Five patients were VGPR or partial response after ASCT but maintained response with 2-year bortezomib maintenance. Two-year overall and progression-free survival rates were 92.5% (95% confidence interval [CI]: 78.5%−97.5%) and 62.6% (95% CI: 45.8%−75.5%), respectively. Grade 3/4 toxicities (≥ 10%) included neutropenia (19%) and anemia (17%) in induction, and thrombocytopenia (29%) in consolidation. [Conclusion:] VCD induction/consolidation and bortezomib maintenance with ASCT for NDMM resulted in a high CR/sCR rate and provided good overall/progression-free survival in Japan
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