Publications by authors named "Tomonori Saito"

58 Publications

Ischemic hepatitis with infectious endocarditis: A case report.

Biomed Rep 2021 Nov 22;15(5):97. Epub 2021 Sep 22.

Department of Gastroenterology, Suzuka General Hospital, Suzuka, Mie 513-8630, Japan.

A 58-year-old woman was admitted to Suzuka General Hospital with fever. She was diagnosed with infectious endocarditis based on the presence of anterior mitral leaflet vegetation on the echocardiography analysis and isolation of by blood culture. During treatment, the hepatic enzymes levels, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were increased without any abdominal symptoms. Prolonged prothrombin time (PT) and prothrombin time international normalized ratio were observed, and acute hepatic failure was diagnosed. However, the hepatic injury resolved spontaneously with restoration of the PT value after the hepatic enzymes (AST, ALT, LDH and ALP) peaked. Diffusion-weighted imaging of hepatic magnetic resonance imaging showed diffuse high intensity of the entire liver except for part of the left lobe. The hepatic injury was diagnosed as ischemic hepatitis caused by embolization from the vegetation associated with infectious endocarditis. The recovery from hepatic ischemia was thought to be due to hepatic blood supply from extrahepatic collateral blood. After antibiotic treatment, the patient underwent resection of the vegetation on the anterior mitral valve leaflet. Hepatic artery occlusion is rare, but it may cause severe hepatic complications. During follow-up of infectious endocarditis, clinicians should be aware of the potential for whole organ ischemic damage caused by vessel occlusion, as well as hepatic ischemic damage.
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http://dx.doi.org/10.3892/br.2021.1473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8493543PMC
November 2021

Additive manufacturing of strong silica sand structures enabled by polyethyleneimine binder.

Nat Commun 2021 Aug 26;12(1):5144. Epub 2021 Aug 26.

Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.

Binder Jet Additive Manufacturing (BJAM) is a versatile AM technique that can form parts from a variety of powdered materials including metals, ceramics, and polymers. BJAM utilizes inkjet printing to selectively bind these powder particles together to form complex geometries. Adoption of BJAM has been limited due to its inability to form strong green parts using conventional binders. We report the discovery of a versatile polyethyleneimine (PEI) binder for silica sand that doubled the flexural strength of parts to 6.28 MPa compared with that of the conventional binder, making it stronger than unreinforced concrete (~4.5 MPa) in flexural loading. Furthermore, we demonstrate that PEI in the printed parts can be reacted with ethyl cyanoacrylate through a secondary infiltration, resulting in an increase in flexural strength to 52.7 MPa. The strong printed parts coupled with the ability for sacrificial washout presents potential to revolutionize AM in various applications including construction and tooling.
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http://dx.doi.org/10.1038/s41467-021-25463-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8390701PMC
August 2021

Polymers with Dynamic Bonds: Adaptive Functional Materials for a Sustainable Future.

J Phys Chem B 2021 08 29;125(33):9389-9401. Epub 2021 Jul 29.

Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.

Polymeric materials play critical role in many current technologies. Among them, adaptive polymeric materials with dynamic (reversible) bonds exhibit unique properties and provide exciting opportunities for various future technologies. Dynamic bonds enable structural rearrangements in polymer networks in specific conditions. Replacement of a few covalent bonds by dynamic bonds can enhance polymeric properties, e.g., strongly improve the toughness and the adhesive properties of polymers. Moreover, they provide recyclability and enable new properties, such as self-healing and shape memory effects. We briefly overview new developments in the field of polymers with dynamic bonds and current understanding of their dynamic properties. We further highlight several examples of unique properties of polymers with dynamic bonds and provide our perspectives for them to be used in many current and future applications.
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http://dx.doi.org/10.1021/acs.jpcb.1c03511DOI Listing
August 2021

Early stage clear cell adenocarcinoma coexisting with tubular adenoma and adenoma with clear cell change in the colon.

Clin J Gastroenterol 2021 Apr 8;14(2):589-593. Epub 2021 Jan 8.

Department of Clinical Laboratory Medicine, Shiga University of Medical Science, 520-2192, Seta Tsukinowa, Otsu, Shiga, Japan.

Primary clear cell adenocarcinoma (CCA) of the colorectum is rare. We report a case of a 57-year-old man with early-stage CCA with conventional tubular adenoma and tubular adenoma with clear cell change in the transverse colon, diagnosed with image-enhanced endoscopy. The tumor was then treated with endoscopic submucosal dissection. The endoscopic findings characteristic of clear cell adenoma/adenocarcinoma could not be identified. Therefore, similar diagnostic tools as for conventional colorectal adenoma/cancer were considered. The pathogenesis of the clear cell change was unknown, but it might appear with the progression of the malignancy.
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http://dx.doi.org/10.1007/s12328-020-01334-xDOI Listing
April 2021

Viscoelasticity in associating oligomers and polymers: experimental test of the bond lifetime renormalization model.

Soft Matter 2020 Jan;16(2):390-401

Department of Materials Science and Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37996, USA.

Recent findings that the association bond lifetimes τα* in associating polymers diverge from their supramolecular network relaxation times τc challenge past theories. The bond lifetime renormalization proposed by Rubinstein and coworkers [Stukalin et al., Macromolecules, 2013, 46, 7525] provides a promising explanation. To examine systematically its applicability, we employ shear rheology and dielectric spectroscopy to study telechelic associating polymers with different main chain (polypropylene glycol and polydimethylsiloxane), molecular weight (below entanglement molecular weight) and end groups (amide, and carboxylic acid) which form dimeric associations by hydrogen bonding. The separation between τc (probed by rheology) and τα* (probed by dielectric spectroscopy) strongly increases with chain length as qualitatively predicted by the model. However, to describe the increase quantitatively, a transition from Rouse to reptation dynamics must be assumed. This suggests that dynamics of super-chains must be considered to properly describe the transient network.
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http://dx.doi.org/10.1039/c9sm01930hDOI Listing
January 2020

What dielectric spectroscopy can tell us about supramolecular networks.

Eur Phys J E Soft Matter 2019 Oct 18;42(10):133. Epub 2019 Oct 18.

Department of Chemistry, University of Tennessee, Knoxville, 37996, Knoxville, TN, USA.

Polymers which can form supramolecular networks are a promising class of materials to provide highly sought-after properties such as self-healing, enhanced mechanical strength, super-stretchability as well as easy recyclability. However, due to the vast range of possible chemical structures it is very demanding to optimize these materials for the desired performance. Consequently, a detailed understanding of the molecular processes that govern the macroscopic properties is paramount to their technological application. Here we discuss some telechelic model systems with hydrogen-bonding end groups and how dielectric spectroscopy in combination with linear oscillatory shear rheology helped to understand the association mechanism on a molecular scale, and verify the model of bond-lifetime renormalization. Furthermore, we analyze a limitation of these H-bonding polymers, namely that there is a trade-off between high plateau modulus and long terminal relaxation time --both cannot be maximized at the same time. Finally, we show how more complex end groups phase separate from the main chain melt and thus lead to a more sophisticated rheological behavior which can overcome that limitation.
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http://dx.doi.org/10.1140/epje/i2019-11897-4DOI Listing
October 2019

The spontaneous clearance of hepatitis E virus (HEV) and emergence of HEV antibodies in a transfusion-transmitted chronic hepatitis E case after completion of chemotherapy for acute myeloid leukemia.

Clin J Gastroenterol 2020 Apr 24;13(2):252-259. Epub 2019 Jul 24.

Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.

A 64-year-old woman was infected with hepatitis E virus (HEV) during chemotherapy for leukemia. By retrospective analyses of stored serum from the blood products and the patient, the source of the infection was determined to be platelet concentration (PC) transfused during chemotherapy. The partial nucleotide sequence of the HEV strain isolated from the donated PC and that from the patient's sera was identical and was subgenotype 3b. Clinical indicators such as alanine aminotransferase, HEV RNA titer, and anti-HEV antibodies in the serum were investigated from the beginning of the infection until 1 year after the termination of HEV infection. HEV RNA had propagated over 6 months and then cleared spontaneously after the completion of chemotherapy. Anti-HEV antibodies appeared in the serum just before the clearance of HEV RNA. Interestingly, HEV RNA was detected in the patient's urine, spinal fluid, and saliva. The HEV RNA titers in those samples were much lower than in the serum and feces. No renal, neurological, or salivary gland disorders appeared during the follow-up. We observed virological and biochemical progress and cure of transfusion-transmitted chronic hepatitis E in the patient despite an immunosuppressive status during and after chemotherapy against hematological malignancy.
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http://dx.doi.org/10.1007/s12328-019-01024-3DOI Listing
April 2020

Structural correlations tailor conductive properties in polymerized ionic liquids.

Phys Chem Chem Phys 2019 Jul;21(27):14775-14785

Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.

Polymerized ionic liquids (PolyILs) are promising materials for applications in electrochemical devices spanning from fuel cells to capacitors and batteries. In principle, PolyILs have a competitive advantage over traditional electrolytes in being single ion conductors and thus enabling a transference number close to unity. Despite this perceived advantage, surprisingly low room temperature ionic conductivities measured in the lab raise an important fundamental question: how does the molecular structure mediate conductivity? In this work, wide-angle X-ray scattering (WAXS), vibrational sum frequency generation (vSFG), and density functional theory (DFT) calculations were used to study the bulk and interfacial structure of PolyILs, while broad band dielectric spectroscopy (BDS) was used to probe corresponding dynamics and conductive properties for a series of the PolyIL samples with tunable chemistries and structures. Our results reveal that the size of the mobile anions has a tremendous impact on chain packing in PolyILs that wasn't addressed previously. Larger mobile ions tend to create a well-packed structure, while smaller ions frustrate chain packing. The magnitude of these changes and level of structural heterogeneity are shown to depend on the chemical functionality and flexibility of studied PolyILs. Furthermore, these experimental and computational results provide new insight into the correlation between conductivity and structure in PolyILs, suggesting that structural heterogeneity helps to reduce the activation energy for ionic conductivity in the glassy state.
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http://dx.doi.org/10.1039/c9cp02268fDOI Listing
July 2019

Understanding the Static Interfacial Polymer Layer by Exploring the Dispersion States of Nanocomposites.

ACS Appl Mater Interfaces 2019 May 1;11(19):17863-17872. Epub 2019 May 1.

Laboratoire Charles Coulomb (L2C), Université de Montpellier , CNRS, F-34095 Montpellier , France.

The dynamic and static properties of the interfacial region between polymer and nanoparticles have wide-ranging consequences on performances of nanomaterials. The thickness and density of the static layer are particularly difficult to assess experimentally due to superimposing nanoparticle interactions. Here, we tune the dispersion of silica nanoparticles in nanocomposites by preadsorption of polymer layers in the precursor solutions, and by varying the molecular weight of the matrix chains. Nanocomposite structures ranging from ideal dispersion to repulsive order or various degrees of aggregation are generated and observed by small-angle scattering. Preadsorbed chains are found to promote ideal dispersion, before desorption in the late stages of nanocomposite formation. The microstructure of the interfacial polymer layer is characterized by detailed modeling of X-ray and neutron scattering. Only in ideally well-dispersed systems a static interfacial layer of reduced polymer density over a thickness of ca. 2 nm is evidenced based on the analysis with a form-free density profile optimized using numerical simulations. This interfacial gradient layer is found to be independent of the thickness of the initially adsorbed polymer, but appears to be generated by out-of-equilibrium packing and folding of the preadsorbed layer. The impact of annealing is investigated to study the approach of equilibrium, showing that initially ideally well-dispersed systems adopt a repulsive hard-sphere structure, while the static interfacial layer disappears. This study thus promotes the fundamental understanding of the interplay between effects which are decisive for macroscopic material properties: polymer-mediated interparticle interactions, and particle interfacial effects on the surrounding polymer.
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http://dx.doi.org/10.1021/acsami.9b04553DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6998785PMC
May 2019

Hepatic Injury without Granulomatous Formation Associated with Intravesical Bacillus Calmette-Guérin Therapy.

Intern Med 2019 May 10;58(10):1429-1432. Epub 2019 Jan 10.

Department of Pathology, Suzuka General Hospital, Japan.

A 74-year-old man developed hepatic injury after intravesical Bacillus Calmette-Guérin (BCG) therapy for bladder carcinoma. Although hepatitis-associated disseminated BCG was suspected, granulomatous formations were undetectable. The hepatic injury was considered to have resulted from an allergic reaction to BCG therapy because a histopathological assessment revealed enlarged portal areas with eosinophils and neutrophils. The hepatic injury was resolved by prednisolone. This case suggested that hepatic injury associated with BCG therapy might be due to an allergic mechanism unrelated to disseminated BCG disease. A liver biopsy is needed to confirm the histopathological findings of hepatic injury after BCG therapy in order to differentiate allergic hepatic injury from infectious hepatic injury.
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http://dx.doi.org/10.2169/internalmedicine.2073-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6548914PMC
May 2019

Conspicuity of Malignant Liver Tumors on Diffusion-Weighted Imaging With Short tau Inversion Recovery After Gadolinium Ethoxybenzyl Diethylenetriaminepentaacetic Acid Administration.

J Magn Reson Imaging 2019 02 13;49(2):565-573. Epub 2018 Aug 13.

Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima City, Japan.

Background: Diffusion-weighted imaging (DWI) has been used for the detection and characterization of liver tumors because it has excellent contrast resolution. DWI using short tau inversion recovery (STIR) can improve tumor-to-liver contrast after gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) administration that shortens the T relaxation of liver parenchyma.

Purpose: To quantitatively and qualitatively compare the conspicuity of malignant liver tumors on DWI after Gd-EOB-DTPA administration between STIR and chemical shift selective (CHESS) sequences.

Study Type: Single-institution retrospective study.

Subjects: Fifty-seven patients with histologically confirmed malignant liver tumors were evaluated.

Field Strength/sequence: Low b-value DWIs with STIR and CHESS sequences 18-20 minutes after Gd-EOB-DTPA administration were acquired at 1.5T.

Assessment: Tumor contrast-to-noise ratio (CNR) and visual grade of tumor conspicuity on DWI between STIR and CHESS sequences were compared.

Statistical Tests: Paired Student's t-test and the Wilcoxon signed rank-test were applied. P < 0.05 was considered statistically significant.

Results: The mean tumor CNR and visual grade of tumor conspicuity on DWI were significantly higher for STIR than for CHESS (both P < 0.001). Regardless of the presence of chronic liver disease, the mean CNR (normal liver 33.5 ± 19.8 vs. 15.7 ± 12.2, P < 0.001; chronic liver disease 19.6 ± 11.0 vs. 9.2 ± 7.8, P < 0.001) and the visual conspicuity grade (normal liver 3.36 ± 0.64 vs. 2.56 ± 0.77, P < 0.001; chronic liver disease 2.94 ± 0.80 vs. 2.25 ± 0.84, P = 0.001) were significantly higher for STIR than for CHESS. Mean CNR and the visual conspicuity grade were also significantly higher for STIR than for CHESS in patients with hepatocellular carcinomas (CNR 18.1 ± 10.5 vs. 8.8 ± 7.2, P < 0.001; visual grade 2.88 ± 0.83 vs. 2.22 ± 0.87, P = 0.001) or metastases (CNR 35.0 ± 19.3 vs. 16.2 ± 13.1, P < 0.001; visual grade 3.45 ± 0.51 vs. 2.59 ± 0.73, P < 0.001).

Data Conclusion: DWI using STIR may be more helpful for depicting malignant liver tumors after Gd-EOB-DTPA administration compared with DWI using CHESS.

Level Of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:565-573.
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http://dx.doi.org/10.1002/jmri.26196DOI Listing
February 2019

Early stage clear cell adenocarcinoma of the colon examined in detail with image-enhanced endoscopy: a case report.

Clin J Gastroenterol 2018 Dec 30;11(6):465-469. Epub 2018 Jul 30.

Department of Pathology, Niigata Cancer Center Hospital, 2-15-3, Kawagishicho, Chuo-ku, Niigata-Shi, Niigata, Japan.

Primary clear cell adenocarcinoma (CCA) of the colorectum is a rare tumor. We report on a 48-year-old man with early stage CCA in the descending colon who underwent detailed examination with image-enhanced endoscopy, such as magnifying endoscopy with narrow-band imaging and crystal violet staining. The tumor was treated successfully with endoscopic mucosal resection at our hospital.
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http://dx.doi.org/10.1007/s12328-018-0889-6DOI Listing
December 2018

Gastric adenocarcinoma coexisting with a reddish semipedunculated polyp arising from Helicobacter pylori-negative normal gastric mucosa: a report of two cases.

Clin J Gastroenterol 2018 Dec 18;11(6):481-486. Epub 2018 Jul 18.

Happy GI Clinic, 2-9-33 Honmachi, Kameyama, Mie, Japan.

We experienced two cases of adenocarcinoma coexisting with a hyperplastic polyp arising from Helicobacter pylori-negative normal gastric mucosa. The first case was of a 59-year-old man. Esophagogastroduodenoscopy revealed a protruding lesion measuring 4 mm in diameter on the greater curvature of the middle gastric body. The second case was of a 47-year-old man. Esophagogastroduodenoscopy showed a protruding lesion measuring 5 mm located at the greater curvature of the upper gastric body. The absence of atrophic changes in the entire gastric mucosa was confirmed endoscopically in both cases. Multiple H. pylori tests were all negative. Endoscopically, these protruding lesions appeared as reddish, semipedunculated polyps. Hyperplastic polyps were suspected based on white light endoscopic findings. Magnified endoscopy with narrow band imaging could not predict the coexistence of cancer. However, histopathological examination of the resected specimen revealed focal cancer at the surface of the gastric hyperplastic polyps. Considering the possibility that cancer may be coexisting in polyps, when reddish polyps are detected in H. pylori-negative normal gastric mucosa, it is important to perform a biopsy, or a careful follow-up endoscopy.
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http://dx.doi.org/10.1007/s12328-018-0887-8DOI Listing
December 2018

Influence of hydrophilic groups and metal-ion adsorption on polymer-chain conformation of amidoxime-based uranium adsorbents.

J Colloid Interface Sci 2018 Aug 6;524:399-408. Epub 2018 Apr 6.

School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0373, USA; Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. Electronic address:

This study focuses on the influence of hydrophilic groups and metal-ion loading on adsorbent polymer conformation, which controls access to adsorption sites and may limit adsorption capacity. Gaining a better understanding of the factors that influence conformation may yield higher-capacity adsorbents. Polyamidoxime (PAO), deuterated-PAO polyacrylic acid diblock copolymers (d-PAO-b-PAA), and randomly configured copolymers (PAO-co-PAA) were synthesized and characterized by neutron reflectometry in air and DO. For d-PAO-b-PAA, characterization was also performed after alkali conditioning and in simulated seawater. PAO and PAO-co-PAA, with similar molecular weight and grafting density, extended from 95-Å thickness in air to 180 and 280-Å in DO, respectively. This result suggests that polymer swelling may cause the additional adsorption capacity observed when polymer hydrophilicity increases. Two d-PAO-b-PAA samples, A and B, with a d-PAO thickness of 55-Å swelled to 110-Å and 140-Å, respectively, with an overall thickness increase of ∼160% in DO. After alkali conditioning, molecular interactions increased the density of PAA near the PAO-PAA interface, while the d-PAO thickness only decreased by ∼10 Å. The d-PAO thickness of both samples declined to ∼90-Å after adsorption in simulated seawater due to polymer-chain crosslinking. These results are expected to aid in improving adsorbent synthesis to increase uranium capacity.
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http://dx.doi.org/10.1016/j.jcis.2018.04.021DOI Listing
August 2018

Estimation of proton density fat fraction of the salivary gland.

Br J Radiol 2018 May 6;91(1085):20170671. Epub 2018 Feb 6.

1 Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University , Fukuoka , Japan.

Objective: Our first objective was to prove the validity of the six-point Dixon method for estimating the proton density fat fraction (PDFF) of the salivary gland. The second objective was to estimate the salivary gland PDFF using Dixon method to evaluate the pathological conditions.

Methods: At first, 12 volunteers underwent two types of sequences: single-voxel magnetic resonance spectroscopy and the Dixon method and the PDFFs obtained by the two methods were compared. Next, a total of 67 individuals [normal, n = 46; Sjögren's syndrome (SS), n = 11; and IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), n = 4, parotitis, n = 6] were enrolled to estimate the parotid gland (PG) and submandibular gland (SMG) PDFF using the Dixon method.

Results: This volunteer study demonstrated excellent correlation between two methods (R = 0.964, slope = 1.05). In the normal group, the PG-PDFF was correlated with the weight and body mass index (BMI) (ρ = 0.38, p = 0.0085; and ρ = 0.63, p < 0.0001). The SMG-PDFF was also correlated with the weight, BMI, and serum triglyceride (ρ = 0.37, p = 0.0067; ρ = 0.42, p = 0.0022; and ρ = 0.35, p = 0.024). The PG-PDFF of the SS group (48.2 ± 15.1%) was higher than that of any other groups; however, no significant difference was found due to the wide overlap. The SS group (39.0 ± 26.14%) also had significantly higher SMG-PDFF than the normal group (8.9 ± 5.4%), p < 0.0001) and IgG4-DS group (3.8 ± 2.3%), p = 0.020).

Conclusion: The Dixon method is a feasible method for estimating the PDFF and demonstrates fat accumulation in SMG in the SS group. Advances in knowledge: The PDFF obtained by the Dixon method is helpful for understanding the salivary gland pathological condition.
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http://dx.doi.org/10.1259/bjr.20170671DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6190763PMC
May 2018

Hydrogen-bond strength changes network dynamics in associating telechelic PDMS.

Soft Matter 2018 Feb;14(7):1235-1246

Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.

Associating polymers are a class of materials with widely tunable macroscopic properties. Here, we investigate telechelic poly(dimethylsiloxanes) of several molecular weights (M) with different hydrogen bonding end groups. Besides the well-established increase of the glass transition temperature T with decreasing M, T remains unchanged as the end group varies from NH over OH to COOH. For the latter system, a 2nd T is found which indicates a segregated phase. In contrast, rheological measurements reveal a qualitative difference in the viscoelastic response of NH-terminated and COOH-terminated chains. Both systems show clear signs of end group association, but only the latter exhibits an extended rubbery plateau. All features observed in the rheology experiments have corresponding processes in the dielectric measurements. This provides insight into the underlying molecular mechanisms, and especially reveals that many end groups of the COOH-terminated chains phase segregate while a certain fraction forms binary associates and remains non-segregated. In contrast, the NH-terminated systems form only binary associates increasing the effective chain length, whereas the COOH-terminated system consists of two types of associates forming a crosslinked network. Remarkably, a single species of end group forms two qualitatively different types of associates: transient bonds which allow stress release by a bond-partner exchange mechanism, and effectively permanent bonds formed by a phase segregated fraction of end groups which are stable on the timescale of the transient mechanism.
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http://dx.doi.org/10.1039/c7sm01805cDOI Listing
February 2018

Effect of Binder Architecture on the Performance of Silicon/Graphite Composite Anodes for Lithium Ion Batteries.

ACS Appl Mater Interfaces 2018 Jan 19;10(4):3470-3478. Epub 2018 Jan 19.

Department of Physics and Engineering Physics, Tulane University , New Orleans, Louisiana 70118, United States.

Although significant progress has been made in improving cycling performance of silicon-based electrodes, few studies have been performed on the architecture effect on polymer binder performance for lithium-ion batteries. A systematic study on the relationship between polymer architectures and binder performance is especially useful in designing synthetic polymer binders. Herein, a graft block copolymer with readily tunable architecture parameters is synthesized and tested as the polymer binder for the high-mass loading silicon (15 wt %)/graphite (73 wt %) composite electrode (active materials >2.5 mg/cm). With the same chemical composition and functional group ratio, the graft block copolymer reveals improved cycling performance in both capacity retention (495 mAh/g vs 356 mAh/g at 100th cycle) and Coulombic efficiency (90.3% vs 88.1% at first cycle) than the physical mixing of glycol chitosan (GC) and lithium polyacrylate (LiPAA). Galvanostatic results also demonstrate the significant impacts of different architecture parameters of graft copolymers, including grafting density and side chain length, on their ultimate binder performance. By simply changing the side chain length of GC-g-LiPAA, the retaining delithiation capacity after 100 cycles varies from 347 mAh/g to 495 mAh/g.
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http://dx.doi.org/10.1021/acsami.7b13205DOI Listing
January 2018

Materials for the Recovery of Uranium from Seawater.

Chem Rev 2017 Dec 22;117(23):13935-14013. Epub 2017 Nov 22.

Chemical Sciences Division, Oak Ridge National Laboratory , One Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.

More than 1000× uranium exists in the oceans than exists in terrestrial ores. With nuclear power generation expected to increase over the coming decades, access to this unconventional reserve is a matter of energy security. With origins in the mid-1950s, materials have been developed for the selective recovery of seawater uranium for more than six decades, with a renewed interest in particular since 2010. This review comprehensively surveys materials developed from 2000-2016 for recovery of seawater uranium, in particular including recent developments in inorganic materials; polymer adsorbents and related research pertaining to amidoxime; and nanostructured materials such as metal-organic frameworks, porous-organic polymers, and mesoporous carbons. Challenges of performing reliable and reproducible uranium adsorption studies are also discussed, as well as the standardization of parameters necessary to ensure valid comparisons between different adsorbents.
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http://dx.doi.org/10.1021/acs.chemrev.7b00355DOI Listing
December 2017

Tunable synthetic control of soft polymeric nanoparticle morphology.

Soft Matter 2017 Nov;13(46):8849-8857

Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA.

With a growing variety of nanoparticles available, research probing the influence of particle deformability, morphology, and topology on the behavior of all polymer nanocomposites is also increasing. In particular, the behavior of soft polymeric nanoparticles in polymer nanocomposites has displayed unique behavior, but their precise performance depends intimately on the internal structure and morphology of the nanoparticle. With the goal of providing guidelines to control the structure and morphology of soft polymeric nanoparticles, we have examined monomer starved semi-batch nano-emulsion polymerizations that form organic, soft nanoparticles, to correlate the precise structure of the nanoparticle to the rate of monomer addition and crosslinking density. The synthesis method produces 5-20 nm radii polystyrene nanoparticles with tunable morphologies. We report small angle neutron scattering (SANS) results that correlate synthetic conditions to the structural characteristics of soft polystyrene nanoparticles. These results show that the measured molecular weight of the nanoparticles is controlled by the monomer addition rate, the total nanoparticle radius is controlled by the excess surfactant concentration, and the crosslinking density has a direct effect on the topology of each nanoparticle. These studies thus provide pathways to control these 3 structural characteristics of the nanoparticle. This research, therefore provides a conduit to thoroughly investigate the effect of structural features of soft nanoparticles on their individual properties and those of their polymer nanocomposites.
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http://dx.doi.org/10.1039/c7sm01533jDOI Listing
November 2017

Usefulness of Endoscopic Transpapillary Tissue Sampling for Malignant Biliary Strictures and Predictive Factors of Diagnostic Accuracy.

Clin Endosc 2018 Mar 31;51(2):174-180. Epub 2017 Aug 31.

Department of Surgery, Suzuka General Hospital, Suzuka, Japan.

Background/aims: It is sometimes difficult to distinguish between malignant and benign biliary strictures using imaging studies alone, and pathological diagnosis is necessary. The aim of this study was to determine the usefulness of endoscopic transpapillary tissue sampling and factors predictive of diagnostic accuracy.

Methods: From April 2008 to December 2014, 136 patients underwent endoscopic transpapillary tissue sampling for malignant biliary strictures. The cytological and histological findings were reported as negative, suspicious, or positive. Suspicious and positive findings were defined as pathologically positive.

Results: The sensitivity was 65.0% for forceps biopsy, 49.5% for brush cytology, 46.2% for bile aspiration cytology, and 21.9% for endoscopic nasobiliary drainage cytology. The combination of these procedures improved the sensitivity (72.8%). Endoscopic transpapillary tissue sampling was more sensitive for lesions of biliary origin (91.4%) than for extrabiliary lesions (66.3%). In surgical cases, the sensitivity for tumors with an infiltrative growth pattern (53.3%) was significantly lower than for a tumor with an expanding or intermediate growth pattern (87.5%).

Conclusions: Combining procedures can improve diagnostic accuracy. It may be possible to predict the sensitivity of endoscopic transpapillary tissue sampling by evaluating the etiology and tumor growth pattern using preoperative imaging studies.
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http://dx.doi.org/10.5946/ce.2017.082DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5903074PMC
March 2018

Robust and Elastic Polymer Membranes with Tunable Properties for Gas Separation.

ACS Appl Mater Interfaces 2017 Aug 28;9(31):26483-26491. Epub 2017 Jul 28.

Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States.

Polymer membranes with the capability to process a massive volume of gas are especially attractive for practical applications of gas separation. Although much effort has been devoted to develop novel polymer membranes with increased selectivity, the overall gas-separation performance and lifetime of membrane are still negatively affected by the weak mechanical performance, low plasticization resistance and poor physical aging tolerance. Recently, elastic polymer membranes with tunable mechanical properties have been attracting significant attentions due to their tremendous potential applications. Herein, we report a series of urethane-rich PDMS-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation. The cross-link density of U-PDMS-NWs is tailored by varying the molecular weight (M) of PDMS. The U-PDMS-NWs show up to 400% elongation and tunable Young's modulus (1.3-122.2 MPa), ultimate tensile strength (1.1-14.3 MPa), and toughness (0.7-24.9 MJ/m). All of the U-PDMS-NWs exhibit salient gas-separation performance with excellent thermal resistance and aging tolerance, high gas permeability (>100 Barrer), and tunable gas selectivity (up to α[P/P] ≈ 41 and α[P/P] ≈ 16). With well-controlled mechanical properties and gas-separation performance, these U-PDMS-NW can be used as a polymer-membrane platform not only for gas separation but also for other applications such as microfluidic channels and stretchable electronic devices.
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http://dx.doi.org/10.1021/acsami.7b09017DOI Listing
August 2017

A case of diminished pericardial effusion after treatment of a giant hepatic cyst.

Clin J Gastroenterol 2017 Aug 18;10(4):377-382. Epub 2017 May 18.

Department of Cardiology, Suzuka General Hospital, 1275-53 Yasuduka-cho, Suzuka, Mie, 513-8630, Japan.

A 75-year-old woman was discovered to have a pericardial effusion when she was admitted to our hospital because of a giant hepatic cyst. We could not detect the cause of the effusion and diagnosed idiopathic pericardial effusion. The patient underwent transcutaneous drainage of the hepatic cyst and an injection of antibiotics. There was no communication between the pericardial effusion and the hepatic cyst. Although the hepatic cyst was reduced in size, the pericardial effusion showed no remarkable change immediately after treatment; however, 5 months later, the pericardial effusion was found to be diminished. The pericardial effusion might have been caused by the physical pressure of the giant hepatic cyst and disturbance in the balance between the production and reabsorption of the pericardial fluid. When we experience a huge hepatic cyst, we should take into account its influence against the surrounding organs, including the intrapleural space.
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http://dx.doi.org/10.1007/s12328-017-0748-xDOI Listing
August 2017

A Rayleighian approach for modeling kinetics of ionic transport in polymeric media.

J Chem Phys 2017 Feb;146(6):064902

Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

We report a theoretical approach for analyzing impedance of ionic liquids (ILs) and charged polymers such as polymerized ionic liquids (PolyILs) within linear response. The approach is based on the Rayleigh dissipation function formalism, which provides a computational framework for a systematic study of various factors, including polymer dynamics, in affecting the impedance. We present an analytical expression for the impedance within linear response by constructing a one-dimensional model for ionic transport in ILs/PolyILs. This expression is used to extract mutual diffusion constants, the length scale of mutual diffusion, and thicknesses of a low-dielectric layer on the electrodes from the broadband dielectric spectroscopy measurements done for an IL and three PolyILs. Also, static dielectric permittivities of the IL and the PolyILs are determined. The extracted mutual diffusion constants are compared with the self-diffusion constants of ions measured using pulse field gradient (PFG) fluorine nuclear magnetic resonance (NMR). For the first time, excellent agreement between the diffusivities extracted from the Electrode Polarization spectra (EPS) of IL/PolyILs and those measured using the PFG-NMR are found, which allows the use of the EPS and the PFG-NMR techniques in a complimentary manner for a general understanding of the ionic transport.
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http://dx.doi.org/10.1063/1.4975309DOI Listing
February 2017

Hemostasis by esophageal stent placement for management of esophageal tumor bleeding:a case report.

Nihon Shokakibyo Gakkai Zasshi 2016 ;113(12):2029-2034

Department of Gastroenterology, Suzuka General Hospital.

A 67-year-old male was diagnosed with advanced esophageal cancer. A computed tomography scan showed multiple intra-abdominal lymphadenopathies. Because the tumor was thought to be unresectable, we initiated chemotherapy. Twelve months later, the patient was admitted to our hospital because of hematemesis. Gastroduodenoscopy revealed oozing bleeding from the esophageal tumor. Hemostasis was not achieved with conservative treatment, and frequent blood transfusions were required. Endoscopic hemostasis was difficult to achieve because of the malignant esophageal stenosis. To treat the malignant esophageal stricture and esophageal tumor bleeding, we attempted to insert an esophageal covered self-expandable metallic stent. After the procedure, hemostasis was achieved by mechanical tamponade. Here we report a rare case of esophageal tumor bleeding that was managed with mechanical tamponade using an esophageal covered self-expandable metallic stent.
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http://dx.doi.org/10.11405/nisshoshi.113.2029DOI Listing
May 2017

An impacted minor papilla stone in a patient with pancreas divisum that caused acute exacerbation of chronic pancreatitis: a case report.

Nihon Shokakibyo Gakkai Zasshi 2016 ;113(11):1916-1922

Department of Gastroenterology, Suzuka General Hospital.

A 75-year-old woman with epigastric pain was admitted to our emergency department. She was diagnosed with an acute exacerbation of chronic pancreatitis based on the results of blood tests and abdominal computed tomography (CT). The abdominal CT and magnetic resonance cholangiopancreatography revealed pancreas divisum. Abdominal CT also showed a stone in the minor papilla, with impaction of the stone being the most likely cause of the acute episode. Therefore, endoscopic sphincterotomy of the minor papilla and endoscopic naso-pancreatic duct drainage were performed to remove the stone and decrease the internal pressure of the pancreatic duct. These procedures improved the patient's clinical status. The naso-pancreatic drainage tube was removed, and her pancreatitis has not recurred. Herein, we report a rare case of an impacted minor papilla stone in a patient with pancreas divisum that caused an acute exacerbation of chronic pancreatitis.
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http://dx.doi.org/10.11405/nisshoshi.113.1916DOI Listing
March 2017

Controlling Interfacial Dynamics: Covalent Bonding versus Physical Adsorption in Polymer Nanocomposites.

ACS Nano 2016 07 29;10(7):6843-52. Epub 2016 Jun 29.

Department of Chemistry, Columbus State University , Columbus, Georgia 33232, United States.

It is generally believed that the strength of the polymer-nanoparticle interaction controls the modification of near-interface segmental mobility in polymer nanocomposites (PNCs). However, little is known about the effect of covalent bonding on the segmental dynamics and glass transition of matrix-free polymer-grafted nanoparticles (PGNs), especially when compared to PNCs. In this article, we directly compare the static and dynamic properties of poly(2-vinylpyridine)/silica-based nanocomposites with polymer chains either physically adsorbed (PNCs) or covalently bonded (PGNs) to identical silica nanoparticles (RNP = 12.5 nm) for three different molecular weight (MW) systems. Interestingly, when the MW of the matrix is as low as 6 kg/mol (RNP/Rg = 5.4) or as high as 140 kg/mol (RNP/Rg= 1.13), both small-angle X-ray scattering and broadband dielectric spectroscopy show similar static and dynamic properties for PNCs and PGNs. However, for the intermediate MW of 18 kg/mol (RNP/Rg = 3.16), the difference between physical adsorption and covalent bonding can be clearly identified in the static and dynamic properties of the interfacial layer. We ascribe the differences in the interfacial properties of PNCs and PGNs to changes in chain stretching, as quantified by self-consistent field theory calculations. These results demonstrate that the dynamic suppression at the interface is affected by the chain stretching; that is, it depends on the anisotropy of the segmental conformations, more so than the strength of the interaction, which suggests that the interfacial dynamics can be effectively tuned by the degree of stretching-a parameter accessible from the MW or grafting density.
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http://dx.doi.org/10.1021/acsnano.6b02501DOI Listing
July 2016

A case of gastric crystal-storing histiocytosis.

Nihon Shokakibyo Gakkai Zasshi 2016 ;113(6):968-74

Department of Gastroenterology, JA Suzuka General Hospital.

A 54-year-old male patient underwent upper gastrointestinal endoscopy, which revealed a 25-mm brown region in the angular section of the greater curvature of the stomach. The region was histologically determined to be gastric mucosa with an accumulation of histiocytes containing eosinophilic substances in the cytoplasm and chronic inflammatory cell infiltration. Histiocytes were immunohistologically positive for CD68, IgG, and κ. Based on these findings, the patient was diagnosed with gastric crystal-storing histiocytosis comprised of histiocytes phagocytosing IgG-κ-type immunoglobulin. This is a rare disease of which there have been no previous reports that included long-term follow-up. Here, we report the case with a literature review.
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http://dx.doi.org/10.11405/nisshoshi.113.968DOI Listing
February 2017

[Acute obstructive suppurative pancreatic ductitis after endoscopic retrograde cholangiopancreatography in a patient with carcinoma of the pancreatic head:a case report].

Nihon Shokakibyo Gakkai Zasshi 2016 ;113(2):289-95

Department of Gastroenterology, Suzuka General Hospital.

An 85-year-old woman with jaundice was referred to our hospital where she was diagnosed with obstructive jaundice due to carcinoma of the pancreatic head based on blood tests and abdominal computed tomography (CT). We performed endoscopic retrograde cholangiopancreatography (ERCP) for biliary drainage, but 5 days after the procedure, she complained of epigastric pain. Laboratory data revealed an elevated white blood cell count and a high serum amylase concentration. Follow-up CT 6 days after the ERCP revealed that the main pancreatic duct diameter had increased since the time of admission. Therefore, ERCP was performed for pancreatic ductal drainage. Purulent pancreatic juice was drained by endoscopic placement of a nasopancreatic drainage tube in the main pancreatic duct, resulting in marked alleviation of clinical symptoms;however, after removal of the tube, the abdominal pain recurred. Subsequent endoscopic placement of a pancreatic stent improved her clinical status once again. Herein, we report this rare case of acute obstructive suppurative pancreatic ductitis in a patient with carcinoma of the pancreatic head.
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http://dx.doi.org/10.11405/nisshoshi.113.289DOI Listing
February 2017

Unexpected Molecular Weight Effect in Polymer Nanocomposites.

Phys Rev Lett 2016 Jan 22;116(3):038302. Epub 2016 Jan 22.

Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

The properties of the interfacial layer between the polymer matrix and nanoparticles largely determine the macroscopic properties of polymer nanocomposites (PNCs). Although the static thickness of the interfacial layer was found to increase with the molecular weight (MW), the influence of MW on segmental relaxation and the glass transition in this layer remains to be explored. In this Letter, we show an unexpected MW dependence of the interfacial properties in PNC with attractive polymer-nanoparticle interactions: the thickness of the interfacial layer with hindered segmental relaxation decreases as MW increases, in sharp contrast to theoretical predictions. Further analyses reveal a reduction in mass density of the interfacial layer with increasing MW, which can elucidate these unexpected dynamic effects. Our observations call for a significant revision of the current understandings of PNCs and suggest interesting ways to tailor their properties.
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http://dx.doi.org/10.1103/PhysRevLett.116.038302DOI Listing
January 2016
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