Publications by authors named "Daisuke Hojo"

19 Publications

  • Page 1 of 1

Improvement in Surgical Outcomes Using 3D Printed Models for Lateral Pelvic Lymph Node Dissection in Rectal Cancer.

Dis Colon Rectum 2021 Oct 29. Epub 2021 Oct 29.

Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo Department of Biostatistics, School of Public Health, Graduate School of Medicine, The University of Tokyo.

Background: Lateral pelvic lymph node dissection for rectal cancer is challenging due to the complexity of the pelvic wall anatomy, and incomplete lateral pelvic lymph node dissection may result in local recurrence in the lateral pelvis. Although three-dimensional printed organ models are useful for understanding spatial anatomy, it currently remains unclear whether they improve surgical outcomes.

Objective: We aimed to assess whether the surgical effectiveness of lateral pelvic lymph node dissection is increased by the use of individualized three-dimensional printed pelvic models.

Design: This was a retrospective study using a propensity matching analysis.

Settings: This study was conducted at a university hospital in Japan.

Patients: In total, 115 patients comprising 184 pelvic sides (right, 85 sides; left, 99 sides) who underwent lateral pelvic lymph node dissection for colorectal adenocarcinoma between January 2012 and December 2019 were enrolled.

Interventions: We compared surgical outcomes using three-dimensional printed pelvic models with control outcomes.

Main Outcome Measures: The primary outcome was the number of harvested lateral pelvic lymph nodes on one pelvic side after the propensity matching analysis.

Results: After matching, 35 pelvic sides each were allocated to the three-dimensional model and control groups, and no significant differences were observed in patient characteristics between the two groups. The number of harvested lateral pelvic lymph nodes was significantly higher in the three-dimensional model group (median, 9; range 3-16) than in the control group (median, 6; range, 0-22) (p=0.047).

Limitations: This was a retrospective study using propensity score matching. However, historical backgrounds were not matched and the majority of lateral pelvic lymph node dissection procedures in the three-dimensional model group were recently performed. This limitation may have influenced surgical outcomes.

Conclusion: The present study demonstrated that by referring to individualized three-dimensional printed pelvic models, colorectal surgeons harvested a larger number of lateral pelvic lymph nodes during lateral pelvic lymph node dissection. This result suggests that three-dimensional printed models help surgeons to complete more detailed procedures. See Video Abstract at http://links.lww.com/DCR/B776.
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http://dx.doi.org/10.1097/DCR.0000000000002327DOI Listing
October 2021

Retrospective analysis of the effect of inhaler education on improvements in inhaler usage.

Respir Investig 2021 May 23;59(3):312-319. Epub 2020 Oct 23.

Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.

Introduction: Various types of inhalation devices have been released, and it is necessary to acquire the skills for using each of them. The factors that have been previously associated with poor inhalator usage include gender, duration of disease, age, and the type of device. However, it is unclear whether these factors also apply to the Japanese population. The number of education sessions needed to acquire inhaler usage skills is also not established.

Patients And Methods: We performed a retrospective review of the medical records of selected patients and their subjective assessments of their inhaler usage skills between January 2016 and March 2018. The primary outcome was the effect of inhaler education for each inhaler device. The secondary outcomes were the factors affecting the effectiveness of inhaler education, the effects of inhalation education stratified by age, and the number of inhaler education sessions needed to improve inhaler usage skills.

Results: Data from 399 patients were analyzed. Age and the type of delivery device affected the mastery of inhaler usage skills. Approximately half of the patients had acquired inhaler usage skills during baseline evaluation. Approximately 90% of patients acquired inhalation usage skills after two education sessions, regardless of the type of inhalation device. Among the older patients, 35.0% had acquired inhaler usage skills during the baseline evaluation, and 86.8% acquired them after two education sessions.

Conclusions: Inhaler usage skills significantly improved, regardless of the device, after inhalation education, and this was also observed in elderly patients after two education sessions.
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http://dx.doi.org/10.1016/j.resinv.2020.09.008DOI Listing
May 2021

Establishment of deformable three-dimensional printed models for laparoscopic right hemicolectomy in transverse colon cancer.

ANZ J Surg 2021 Jul 26;91(7-8):E493-E499. Epub 2021 Feb 26.

Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.

Background: Applications of three-dimensional (3-D) printed solid organ models for navigation and simulation were previously reported for abdominal surgeries, and their usefulness was shown by subjective evaluation. However, thus far, no study has examined the effect of intraoperative movements for tissue handling. Novel, deformable 3-D printed models of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) were created to optimize laparoscopic right hemicolectomy. The aim of this study was to establish a method using these individualized models for use in surgical practice.

Methods: Deformable 3-D models for laparoscopic right hemicolectomy were created using a 3-D printing flexible filamentous material (thermoplastic polyurethane). Five patients with transverse colon cancer who underwent laparoscopic right hemicolectomy with D3 lymphadenectomy between April 2017 and September 2019 were enrolled in this study. Then, the created patient-specific models were compared with the previously recorded intraoperative video views.

Results: Transverse colon mobilization changed the spatial arrangement of the branches of the SMA and SMV. The 3-D models reproduced the intraoperative view, although approaches to the dominant vessels to complete D3 lymphadenectomy may vary.

Conclusions: Deformable 3-D models of the SMA and SMV with added branches may aid in optimizing laparoscopic right hemicolectomy operations.
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http://dx.doi.org/10.1111/ans.16659DOI Listing
July 2021

A Questionnaire Survey of the Inhalation Instruction in Pharmacies.

Kobe J Med Sci 2020 Nov 17;66(3):E113-E118. Epub 2020 Nov 17.

Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.

Few studies have focused on the inhalation instruction in pharmacies which have the crucial role on the inhalation instruction. The aim of this study is to evaluate the level of knowledge and the degree of interest for asthma inhalation instruction methods among pharmacists receiving prescription from clinics. We conducted questionnaire surveys to chief pharmacists of 39 consecutive pharmacies belonging to HANSHIN Dispensing Pharmacy in Hyogo, Japan at July 2011. We obtained valid responses from 35 pharmacies. Among them, 14 pharmacies dealt with prescriptions mainly from the clinics (clinic pharmacies) and 21 pharmacies dealt with prescriptions originated from hospitals (hospital pharmacies), including 13 pharmacies that dealt with prescription filled by respiratory physicians (specialty hospital pharmacies). Although the inhalation instruction at the first visit was provided at every pharmacy, only 54.3% of all pharmacies provided inhalation instructions after the second visit. Compared to 0% of the clinic pharmacies, 40% of the specialty hospital pharmacies visually checked the patient's inhalation procedure after the second visit. Visual confirmation of the inhalation technique, especially in the clinic pharmacies, might play an important role in maintaining treatment adherence.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7837665PMC
November 2020

Utility of a three-dimensional printed pelvic model for lateral pelvic lymph node dissection.

Int J Colorectal Dis 2020 May 2;35(5):905-910. Epub 2020 Mar 2.

Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.

Purpose: In patients with advanced lower rectal cancer, the complex pelvic anatomy renders lateral pelvic lymph node dissection to be challenging. Therefore, we evaluated the utility of printing a three-dimensional (3D) pelvic model for lateral pelvic lymph node dissection.

Methods: We included 22 patients who underwent lateral pelvic lymph node dissection for rectal cancer between June 2017 and February 2019. Using CT scans, 3D pelvic images and models were constructed and printed, respectively. Thirty colorectal surgeons subjectively evaluated the utility of 3D pelvic models based on a 5-point Likert scale questionnaire (1 = strongly disagree, 5 = strongly agree).

Results: The average Likert score for the question "Would a 3D model be useful for understanding pelvic anatomy?" was 4.68. Cases with clinically diagnosed metastatic lymph nodes (4.79 ± 0.44) scored higher than those without them (4.38 ± 0.77, p = 0.02). For spatial comprehension of pelvic anatomy, 3D models scored higher (4.83) than 3D images (4.36, p < 0.001). The ease of use of 3D models and images was scored 4.60 and 4.20, respectively (p = 0.015). With experience, the 3D image reconstruction time decreased from 900 to 150 min.

Conclusion: The 3D pelvic models may be helpful for experienced surgeons to understand the pelvic anatomy in lateral pelvic lymph node dissection.
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http://dx.doi.org/10.1007/s00384-020-03534-wDOI Listing
May 2020

A cross sectional study to investigate internal hernia post left-sided colectomy preserving superior rectal artery.

Ann Med Surg (Lond) 2019 Dec 4;48:124-128. Epub 2019 Nov 4.

Department of Surgical Oncology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Background: and Purpose: Intestinal obstruction caused by an internal hernia projecting through a mesenteric defect is a rare sequela of laparoscopic colectomy, as surgeons usually leave such defects open. In this study, we investigated cases of internal hernia after laparoscopic left-sided colectomy.

Methods: Data of 308 patients who underwent laparoscopic left hemicolectomy or sigmoidectomy at our institute between 2013 and 2018 were retrospectively reviewed. Patient characteristics and surgical variables were analyzed. The distance between the superior rectal artery (SRA) and abdominal aorta at the level of aortic bifurcation was measured using postoperative computed tomography in patients who underwent SRA-preserving colectomy.

Results: In all, 3 patients (0.97%), all of whom had undergone colostomy without anastomosis and with SRA preservation, developed internal hernia passing between the SRA and the aorta. The distance between the SRA and abdominal aorta in patients who underwent ostomy was significantly more than that in patients who underwent non-ostomy (10.6 mm vs. 4.7 mm, respectively, p < 0.001).

Conclusions: SRA preservation and stoma construction are potential risk factors for internal hernia after laparoscopic left-sided colectomy. Lifting of the SRA due to stoma construction possibly enlarges the space between the SRA and aorta. When colostomy is created, it is important to evaluate the space behind the SRA.
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http://dx.doi.org/10.1016/j.amsu.2019.10.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864359PMC
December 2019

Utility of a Three-Dimensional Printed Pelvic Model for Lateral Pelvic Lymph Node Dissection Education: A Randomized Controlled Trial.

J Am Coll Surg 2019 12 5;229(6):552-559.e3. Epub 2019 Sep 5.

Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.

Background: Lateral pelvic lymph node dissection for rectal cancer is a difficult technique due to the complex pelvic anatomy involved. Three-dimensional (3D) organ models have been introduced as education tools to study anatomy in some fields. In this study, we educated the participants about pelvic anatomy using a 3D model, and evaluated learning efficiency, comparing the outcomes with those using a traditional textbook.

Study Design: This study was a randomized, controlled, single-center trial conducted between July 2018 and July 2019. A total of 102 participants (34 medical students, 34 residents, and 34 surgeons) were enrolled. Participants were randomly assigned to the 3D model group or the textbook group. First, they completed a short test to confirm their basic knowledge before further education. After collocated education, they completed the same short test again and another long test to evaluate their learning outcomes.

Results: Before education, there was no significant difference in the short test scores between the 3D model group and the textbook group. After education, the short and long test scores of the 3D model group were significantly higher than those of the textbook group for students (short test; p = 0.05, long test; p = 0.03), residents (short test; p = 0.05, long test; p = 0.002), and surgeons (short test; p = 0.009, long test; p < 0.001).

Conclusions: Using a 3D pelvic model is superior to using a textbook when learning pelvic anatomy required for lateral pelvic lymph node dissection.
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http://dx.doi.org/10.1016/j.jamcollsurg.2019.08.1443DOI Listing
December 2019

Efficacy of 18-fluoro deoxy glucose-positron emission tomography computed tomography for the detection of colonic neoplasia proximal to obstructing colorectal cancer.

Medicine (Baltimore) 2018 Aug;97(31):e11655

Department of Surgical Oncology Division of Nuclear medicine, Department of Radiology, Faculty of Medicine, University of Tokyo Department of Radiology, International University of Health and Welfare, School of Medicine, Japan.

Identification of secondary colonic neoplasia proximal to obstructing colorectal cancer is essential for determining the range of colorectal resection.We examined the accuracy of 18-fluoro deoxy glucose-positron emission tomography (FDG-PET) for detection of colonic neoplasia.We recruited patients with obstructing colorectal cancer from our registry. Preoperative FDG-PET was performed, and the detection rate for colonic neoplasia was estimated. Preoperative colonoscopy or postoperative colonoscopy within a year after operation was employed as the indexed standard.Ninety-three patients were included in this study. Colonic neoplasia proximal to obstruction was confirmed in 83 cases. The sensitivity and positive predictive value of FDG-PET were 25.3% and 77.8%, respectively. The sensitivity was higher in larger lesions (3.2% for <5 mm, 29.4% for 6-10 mm, 45.5% for 11-20 mm, and 71.4% for >21 mm) and in higher pathological grade lesions (14.6% for low-grade adenoma, 38.5% for high-grade adenoma, 66.7% for carcinoma in situ, and 100% for invasive carcinoma). The round shape in PET images was a predictor for neoplasia, with an area under the curve of 0.75293 at an aspect ratio of 1.70.FDG-PET should be used as a screening modality for invasive colorectal cancer (CRC) proximal to obstructing colorectal cancer.
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http://dx.doi.org/10.1097/MD.0000000000011655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6081081PMC
August 2018

Marked edema of colonic stoma after colectomy and severe pulmonary hypertension: Report of two cases.

Clin Res Hepatol Gastroenterol 2018 02 29;42(1):e1-e4. Epub 2017 Dec 29.

Department of Surgical Oncology, Faculty of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.

Introduction: Pulmonary hypertension (PH) is a disease with a poor prognosis and is a risk for perioperative heart and respiratory failure. Few reports exist regarding a colectomy performed in patients with PH. Herein, we report two cases of colectomy performed in patients with severe PH, accompanied with marked edema of the colonic stoma after surgery.

Case Presentation: In case 1, a 54-year-old patient with sigmoid cancer and severe primary PH underwent Hartmann's operation. After the operation, his stoma became markedly edematous and ulcerated. Swelling of the stoma became gradually reduced, and the patient was discharged from hospital 36 days after the operation. In case 2, a 62-year-old patient with upper rectal cancer and severe PH also underwent Hartmann's operation; his stoma became markedly edematous without ulceration.

Conclusion: Marked edema of the colonic stoma was observed in two cases with severe PH, with ulceration of the mucosa observed in one case. It was considered reasonable to avoid anastomosis in cases with severe PH.
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http://dx.doi.org/10.1016/j.clinre.2017.04.003DOI Listing
February 2018

Catechol-TiO hybrids for photocatalytic H production and photocathode assembly.

Chem Commun (Camb) 2017 Nov;53(94):12638-12641

Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.

Visible-light driven H evolution in water is achieved using catechol-photosensitised TiO nanoparticles with a molecular nickel catalyst. Layer-by-layer immobilisation of catechol-TiO onto tin-doped indium oxide electrodes generates photocathodic currents in the presence of an electron acceptor. This approach represents a new strategy for controlling photocurrent direction in dye-sensitised photoelectrochemical applications.
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http://dx.doi.org/10.1039/c7cc05094aDOI Listing
November 2017

Exploring Step-by-Step Assembly of Nanoparticle:Cytochrome Biohybrid Photoanodes.

ChemElectroChem 2017 08 15;4(8):1959-1968. Epub 2017 May 15.

School of Biomedical Sciences, and The Astbury Centre for Structural Molecular Biology University of Leeds Leeds LS2 9JT U.K.

Coupling light-harvesting semiconducting nanoparticles (NPs) with redox enzymes has been shown to create artificial photosynthetic systems that hold promise for the synthesis of solar fuels. High quantum yields require efficient electron transfer from the nanoparticle to the redox protein, a property that can be difficult to control. Here, we have compared binding and electron transfer between dye-sensitized TiO nanocrystals or CdS quantum dots and two decaheme cytochromes on photoanodes. The effect of NP surface chemistry was assessed by preparing NPs capped with amine or carboxylic acid functionalities. For the TiO nanocrystals, binding to the cytochromes was optimal when capped with a carboxylic acid ligand, whereas for the CdS QDs, better adhesion was observed for amine capped ligand shells. When using TiO nanocrystals, dye-sensitized with a phosphonated bipyridine Ru(II) dye, photocurrents are observed that are dependent on the redox state of the decaheme, confirming that electrons are transferred from the TiO nanocrystals to the surface via the decaheme conduit. In contrast, when CdS NPs are used, photocurrents are not dependent on the redox state of the decaheme, consistent with a model in which electron transfer from CdS to the photoanode bypasses the decaheme protein. These results illustrate that although the organic shell of NPs nanoparticles crucially affects coupling with proteinaceous material, the coupling can be difficult to predict or engineer.
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http://dx.doi.org/10.1002/celc.201700030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573906PMC
August 2017

Electric Properties of Dirac Fermions Captured into 3D Nanoporous Graphene Networks.

Adv Mater 2016 Dec 11;28(46):10304-10310. Epub 2016 Oct 11.

WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.

Nanoporous graphene- based electric-double-layer transistors (EDLTs) are successfully fabricated. Transport measurements of the EDLTs demonstrate that the ambipolar electronic states of massless Dirac fermions with a high carrier mobility are well preserved in 3D nanoporous graphene along with anomalous nonlinear Hall resistance and exceptional transistor on/off ratio. This study may open a new avenue for device applications of graphene.
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http://dx.doi.org/10.1002/adma.201601067DOI Listing
December 2016

Correlation between Chemical Dopants and Topological Defects in Catalytically Active Nanoporous Graphene.

Adv Mater 2016 Dec 10;28(48):10644-10651. Epub 2016 Oct 10.

CREST, Japan Science and Technology Agency, Saitama, 332-0012, Japan.

The interplay between chemical dopants and topological defects plays a crucial role in electrocatalysis of doped graphene. By systematically tuning the curvatures, thereby the density of topological defects, of 3D nanoporous graphene, the intrinsic correlation of topological defects with chemical doping contents and dopant configurations is revealed, shining lights into the structural and chemical origins of HER activities of graphene.
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http://dx.doi.org/10.1002/adma.201604318DOI Listing
December 2016

A case report of anorectal malignant melanoma with mucosal skipped lesion.

Int J Surg Case Rep 2016 30;24:206-10. Epub 2016 Apr 30.

University of Tokyo, Department of Surgical Oncology, Tokyo, Japan. Electronic address:

Introduction: We report our experience involving a case of relatively rare anorectal malignant melanoma with skipped lesion.

Presentation Of Case: The patient was a 72-year-old man who had visited a local clinic complaining of a mass in the anal region, whereupon he was referred to our hospital on suspicion of a malignant melanoma. Close examination revealed a 25-mm black type 1 tumor one-third the size of the circumference of the anal canal and located externally to it. We performed transanal resection of the tumor and confirmed a diagnosis of malignant melanoma. Notably, multiple macular black lesions spaced away from the main lesion were observed during surgery in half of the circumference of the anal canal, from the tumor to the pectinate line. A biopsy of the area also revealed malignant melanoma; therefore, we performed abdominoperineal resection. Pathological diagnosis indicated a submucosal depth; the patient was thus diagnosed with T4 N2c M0 stage IIIb malignant melanoma and was followed on an outpatient basis.

Discussion: Patients with anorectal malignant melanoma have very poor prognoses owing to early lymph node metastasis and hematogenous metastasis. Our case illustrates that small anorectal malignant melanoma lesions can spread from the main lesion and invade the mucosa; examinations may sometimes miss such skipped lesions.

Conclusion: Skipped lesions can occur in anorectal melanomas; thus, careful scrutiny of such lesions is required. Moreover, lesion resection is critical for anorectal malignant melanomas.
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http://dx.doi.org/10.1016/j.ijscr.2016.04.049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4906122PMC
July 2016

Green solvent for green materials: a supercritical hydrothermal method and shape-controlled synthesis of Cr-doped CeO2 nanoparticles.

Philos Trans A Math Phys Eng Sci 2015 Dec;373(2057)

Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 6-6-10 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan

This paper describes a supercritical hydrothermal synthesis method as a green solvent process, along with products based on this method that can be used as green materials that contribute to solving environmental problems. The first part of this paper summarizes the basics of this method, including the mechanism of the reactions, specific features of the supercritical state for nanoparticle synthesis, the continuous flow-type reactor and applications; this provides a better understanding of the suitability of this method to synthesize green materials. The second part of the paper describes the method used to synthesize Cr-doped CeO(2) nanoparticles, which show an extremely high oxygen storage capacity, suggesting their high potential as an environmental catalyst. Transmission electron microscopy and scanning electron microscope images showed octahedral Cr-doped CeO(2) nanoparticles with sizes of 15-30 nm and cubic Cr-doped CeO(2) nanoparticles with sizes of 5-8 nm. Octahedral Cr-doped CeO(2) nanoparticles exposing (111) facets and cubic Cr-doped CeO(2) nanoparticles exposing (100) facets were determined by high-resolution transmission electron microscopy and selected area electron diffraction. The X-ray diffraction peaks shifted to a high angle because the radius of the Cr ion is smaller than that of the Ce ion.
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http://dx.doi.org/10.1098/rsta.2015.0012DOI Listing
December 2015

A Decaheme Cytochrome as a Molecular Electron Conduit in Dye-Sensitized Photoanodes.

Adv Funct Mater 2015 Apr 11;25(15):2308-2315. Epub 2015 Mar 11.

School of Biomedical Sciences, University of Leeds Leeds, LS2 9JT, UK E-mail: ; The Astbury Centre for Structural Molecular Biology, University of Leeds Leeds, LS2 9JT, UK.

In nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. Here, it is aimed to mimic this by coupling dye-sensitized TiO nanocrystals to a decaheme protein, MtrC from MR-1, where the 10 hemes of MtrC form a ≈7-nm-long molecular wire between the TiO and the underlying electrode. The system is assembled by forming a densely packed MtrC film on an ultra-flat gold electrode, followed by the adsorption of approximately 7 nm TiO nanocrystals that are modified with a phosphonated bipyridine Ru(II) dye (RuP). The step-by-step construction of the MtrC/TiO system is monitored with (photo)electrochemistry, quartz-crystal microbalance with dissipation (QCM-D), and atomic force microscopy (AFM). Photocurrents are dependent on the redox state of the MtrC, confirming that electrons are transferred from the TiO nanocrystals to the surface via the MtrC conduit. In other words, in these TiO/MtrC hybrid photodiodes, MtrC traps the conduction-band electrons from TiO before transferring them to the electrode, creating a photobioelectrochemical system in which a redox protein is used to mimic the efficient charge separation found in biological photosystems.
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http://dx.doi.org/10.1002/adfm.201404541DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4493899PMC
April 2015

Chemically exfoliated ReS2 nanosheets.

Nanoscale 2014 Nov;6(21):12458-62

WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.

The production of two-dimensional rhenium disulfide (ReS2) nanosheets by exfoliation using lithium intercalation is demonstrated. The vibrational and photoluminescence properties of the exfoliated nanosheets are investigated, and the local atomic structure is studied by scanning and transmission electron microscopy. The catalytic activity of the nanosheets in a hydrogen evolution reaction (HER) is also investigated. The electrochemical properties of the exfoliated ReS2 nanosheets include low overpotentials of ∼100 mV and low Tafel slopes of 75 mV dec(-1) for HER and are attributed to the atomic structure of the superlattice 1T' phase. The presence of bandgap photoluminescence demonstrates that the nanosheets retain their semiconducting nature. ReS2 nanosheets produced by this method provide unique photocatalytic properties that are superior to those of other two-dimensional systems.
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http://dx.doi.org/10.1039/c4nr03740eDOI Listing
November 2014

Hydrothermal synthesis of inorganic-organic hybrid gadolinium hydroxide nanoclusters with controlled size and morphology.

Dalton Trans 2013 Dec 19;42(45):16176-84. Epub 2013 Sep 19.

New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan.

A series of gadolinium hydroxide [Gd(OH)3] nanoclusters having different morphologies was synthesized in the presence of 3,4-dihydroxy hydrocinnamic acid (DHCA), an organic modifier, under subcritical water conditions. These well-shaped Gd(OH)3 clusters are composed of many nanorods in a parallel orientation, rather than a disordered aggregation of nanorods, which are linked together by organic DHCA molecules. Here DHCA works as an inter-linker to form these cluster-like structures through coordination bonds. All samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and SQUID magnetometry. We investigated the effect of the concentrations of DHCA and KOH on the size and morphology of the Gd(OH)3 clusters. Their possible formation mechanism is also briefly discussed.
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http://dx.doi.org/10.1039/c3dt51692jDOI Listing
December 2013

Atomic layer deposition and abrupt wetting transitions on nonwoven polypropylene and woven cotton fabrics.

Langmuir 2010 Feb;26(4):2550-8

Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.

Atomic layer deposition (ALD) of aluminum oxide on nonwoven polypropylene and woven cotton fabric materials can be used to transform and control fiber surface wetting properties. Infrared analysis shows that ALD can produce a uniform coating throughout the nonwoven polypropylene fiber matrix, and the amount of coating can be controlled by the number of ALD cycles. Upon coating by ALD aluminum oxide, nonwetting hydrophobic polypropylene fibers transition to either a metastable hydrophobic or a fully wetting hydrophilic state, consistent with well-known Cassie-Baxter and Wenzel models of surface wetting of roughened surfaces. The observed nonwetting/wetting transition depends on ALD process variables such as the number of ALD coating cycles and deposition temperature. Cotton fabrics coated with ALD aluminum oxide at moderate temperatures were also observed to transition from a natural wetting state to a metastable hydrophobic state and back to wetting depending on the number of ALD cycles. The transitions on cotton appear to be less sensitive to deposition temperature. The results provide insight into the effect of ALD film growth mechanisms on hydrophobic and hydrophilic polymers and fibrous structures. The ability to adjust and control surface energy, surface reactivity, and wettability of polymer and natural fiber systems using atomic layer deposition may enable a wide range of new applications for functional fiber-based systems.
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http://dx.doi.org/10.1021/la902830dDOI Listing
February 2010
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