Quantum de-trapping and transport of heavy defects in tungsten.

The diffusion of defects in crystalline materials1 controls macroscopic behaviour of a wide range of processes, including alloying, precipitation, phase transformation and creep2. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is dominated by de-trapping processes. It is generally believed that de-trapping occurs only by thermal activation. Here, we report the direct observation of the quantum de-trapping of defects below around one-third of the Debye temperature. We successfully monitored the de-trapping and migration of self-interstitial atom clusters, strongly trapped by impurity atoms in tungsten, by triggering de-trapping out of equilibrium at cryogenic temperatures, using high-energy electron irradiation and in situ transmission electron microscopy. The quantum-assisted de-trapping leads to low-temperature diffusion rates orders of magnitude higher than a naive classical estimate suggests. Our analysis shows that this phenomenon is generic to any crystalline material.

Intensity Interference in a Coherent Spin-Polarized Electron Beam.

We investigate the intensity interference between pairs of electrons using a spin-polarized electron beam having a high polarization and a narrow energy width. We observe spin-dependent antibunching on the basis of coincident counts of electron pairs performed with a spin-polarized transmission electron microscope, which could control the spin-polarization without any changes in the electron optics. The experimental results show that the time correlation was only affected by the spin polarization, demonstrating that the antibunching is associated with fermionic statistics. The coherent spin-polarized electron beam facilitates the extraction of intrinsic quantum interference.

Tunable Liquid Chromatographic Separation of H/D Isotopologues Enabled by Aromatic π Interactions.

We report hydrogen/deuterium (H/D) isotope effects based on weak intermolecular interactions with polar functional groups and aromatic rings in liquid chromatography (LC). Various LC experiments with different aromatic analytes, separation media, and nonpolar mobile phases were conducted under normal phase LC conditions, where the hydrophobic interaction was completely suppressed. The separation media that had polar functional groups, such as silanol groups, allowed for higher separation efficiencies for the pairs of aromatic H/D isotopologues. In comparing the 13C NMR spectra of protiated and deuterated aromatic analytes, the electron density of the deuterated analyte was found to be slightly higher than that of the protiated analytes. In the case of silanol functional groups, aromatic rings of the analyte acted as donors through the OH-π interaction to hydrogen atoms in the silanol groups. Thus, the deuterated analytes were able to be greatly retained by the stronger OH-π interactions. Furthermore, a C70-fullerene bonded monolithic column (C70 column), which effectively provides CH-π interactions, allowed the opposite isotope effect. Briefly, an electrostatic attraction based on the dipole-(induced) dipole interaction dominated in the CH-π interactions, according to a van't Hoff analysis. Hence, the bonding lengths of the C-H or D bonds were sensitively affected, such that we were able to conclude that the CH-π interaction depended on the geometric effect. Applying these opposing H/D isotope effects, we were able to finally demonstrate effective H/D isotopologue separations by utilizing the complementary action of the OH-π and CH-π interactions.

Progress in environmental high-voltage transmission electron microscopy for nanomaterials.

A new environmental high-voltage transmission electron microscope (E-HVEM) was developed by Nagoya University in collaboration with JEOL Ltd. An open-type environmental cell was employed to enable in-situ observations of chemical reactions on catalyst particles as well as mechanical deformation in gaseous conditions. One of the reasons for success was the application of high-voltage transmission electron microscopy to environmental (in-situ) observations in the gas atmosphere because of high transmission of electrons through gas layers and thick samples. Knock-on damages to samples by high-energy electrons were carefully considered. In this paper, we describe the detailed design of the E-HVEM, recent developments and various applications. This article is part of a discussion meeting issue 'Dynamic in situ microscopy relating structure and function'.

3D Vessel Image Reconstruction by MDCT for Surgical Indication and Timing of Strangulating Small Bowel Obstructions.

BACKGROUND: Patients with strangulating small bowel obstructions (SBOs) can rapidly deteriorate, in condition; therefore, immediate and appropriate diagnosis is required. However, some cases of SBO are difficult to diagnose using axial computed tomography (CT) images alone. The impact of 3D vessel imaging for the diagnosis, surgical indication, and timing of strangulating SBOs was investigated, prospectively. METHODS: Clinical data were collected for 111 strangulating SBOs and 48 simple SBOs from patients receiving surgical interventions from January 2009 to March 2018. The accuracy of preoperative diagnoses for the type of SBO was evaluated. Among 159 patients, 27 underwent contrast-enhanced CT imaging as well as prospectively reconstructed 3D vessel imaging of the superior mesenteric artery, vein, and branches. The concordance rate of operative findings and preoperative diagnoses of the type of SBO were compared between axial CT imaging alone and combination of axial and 3D vessel imaging. RESULTS: Overall concordance rate of diagnosis for the type of SBO by axial imaging was 93.1% and that of strangulating and simple SBOs was 92.8% and 93.8%, respectively. Combined axial and 3D vessel imaging resulted in 100% accuracy of preoperative diagnoses for both types of SBO. In addition, abnormalities could be classified from 3D vessel images as central twists or peripheral twists, and deteriorated vascular flow could also be detected. CONCLUSIONS: The combination of axial imaging and 3D vessel imaging can be used to accurately diagnose SBOs, and this imaging technique may be useful for determining the surgical indication and suitable timing of strangulating SBOs.

Influence of gas environment and heating on atomic structures of platinum nanoparticle catalysts for proton-exchange membrane fuel cells.

Atomic-scale relaxations of platinum nanoparticles (Pt NPs) for fuel-cell catalysts are evaluated by spherical-aberration corrected environmental transmission electron microscopy (ETEM) under reference high-vacuum and N2 atmospheres, and then under reactive H2, CO and O2 atmospheres, combined with ex situ durability test using an electrochemical half-cell. In high-vacuum, increasing roughness due to continuous relaxation of surface-adsorbed Pt atoms is quantified in real-space. Under H2 and N2 atmospheres at a critical partial pressure of 1 × 10-2 Pa the stability of the surface facets is for the first time found to be improved. The adsorption behaviour of CO molecules is investigated using experimentally measured Pt-Pt bond lengths on the topmost surface layer of Pt NPs. The deactivation of Pt NPs in the anode environment of a proton-exchange-membrane fuel-cell is demonstrated at the atomic-scale in the ETEM, and the transformation of NPs into disordered nanoclusters is systematically quantified using the partial size distribution of Pt atomic clusters under controlled heating experiments at 423, 573 and 723 K.

[A Case of Rectal Cancers with Pneumonia Combined with Interesting Body Pressure Distribution Before and after Treatment].

A 74-year-old man with aspiration pneumonia was admitted in the internal medicine department. CT revealed progressive carcinoma of RS-Ra, which became the focus of intervention after the pneumonia was treated. After having been allowed temporary discharge, the patient was rehospitalized for surgical operation and rehabilitation. During the perioperative period of cancer patients, we use body distribution data for teaching and environment setting, which is a useful tool in rehabilitation. Rectal cancer was observed after hospitalization for pneumonia, presenting an interesting case. Therefore, care needs to be taken as body pressure distribution may be modified by comorbidity.

[A Case of Metachronous Liver Metastases of Gall Bladder Cancer Successfully Treated by Liver Resection].

A 73-year-old woman was diagnosed with gall bladder cancer by contrast enhanced CT images.The tumor was detected at the fundus of the gall bladder and enhanced heterogeneously.She underwent radical cholecystectomy including Japanese D2 lymph node dissection for gall bladder cancer.After 4 courses of oral S-1(80mg/m2 administered for 4 weeks and then stopped for 2 weeks)as adjuvant chemotherapy, a liver metastasis at segment 5 appeared 11 months postoperatively.It showed a ring enhanced tumor on contrast enhanced CT images.FDG accumulated in a similar lesion on PET-CT images.The patient successfully underwent partial hepatectomy of segment 5 of the liver.However, another liver metastasis at segment 7 appeared 5 months after the second operation, but it was resected successfully.The primary lesion and both liver metastases showed similar microscopic appearances.Seven courses of gemcitabine therapy(gemcitabine 1,000mg/m2 once every week for 3 weeks and then stopped for 1 week)were administered as adjuvant chemotherapy.She is now doing well without any sign of recurrence 2 years after the initial operation and 14 months after the secondary liver resection.

Active control of sound transmission through a rectangular panel using point-force actuators and piezoelectric film sensors.

This study deals with the active control of sound transmission through a rectangular panel, based on single input, single output feedforward vibration control using point-force actuators and piezoelectric film sensors. It focuses on the phenomenon in which the sound power transmitted through a finite-sized panel drops significantly at some frequencies just below the resonance frequencies of the panel in the low-frequency range as a result of modal coupling cancellation. In a previous study, it was shown that when point-force actuators are located on nodal lines for the frequency at which this phenomenon occurs, a force equivalent to the incident sound wave can act on the panel. In this study, a practical method for sensing volume velocity using a small number of piezoelectric film strips is investigated. It is found that two quadratically shaped piezoelectric film strips, attached at the same nodal lines as those where the actuators were placed, can sense the volume velocity approximately in the low-frequency range. Results of simulations show that combining the proposed actuation method and the sensing method can achieve a practical control effect at low frequencies over a wide frequency range. Finally, experiments are carried out to demonstrate the validity and feasibility of the proposed method.

Atomic observation of catalysis-induced nanopore coarsening of nanoporous gold.

Dealloyed nanoporous metals have attracted much attention because of their excellent catalytic activities toward various chemical reactions. Nevertheless, coarsening mechanisms in these catalysts have not been experimentally studied. Here, we report in situ atomic-scale observations of the structural evolution of nanoporous gold during catalytic CO oxidation. The catalysis-induced nanopore coarsening is associated with the rapid diffusion of gold atoms at chemically active surface steps and the surface segregation of residual Ag atoms, both of which are stimulated by the chemical reaction. Our observations provide the first direct evidence that planar defects hinder nanopore coarsening, suggesting a new strategy for developing structurally stable and highly active heterogeneous catalysts.

[A Case of Gastric Cancer with Multiple Liver Metastases Treated with XP Chemotherapy and RFA Resulting in a Complete Response for a Long Time].

A 60-year-old man underwent total gastrectomy with Japanese D2 lymph node dissection for advanced gastric cancer. The resected specimen was diagnosed as well-differentiated tubular carcinoma, pT3, pN1, cM0, and the final stage was considered as ⅡB. During adjuvant chemotherapy with S-1 (120 mg/day, administered for 4 weeks and then stopped for 2 weeks), multiple liver metastases were detected by contrast-enhanced CT images 6 months after the operation. Eight courses of XP therapy (capecitabine 1,600 mg/m2/day: day 1-14, cisplatin 70 mg/m2/day: day 1, then stopped until days 15-21) were administered in consideration of the recurrence during adjuvant chemotherapy with S-1, resulting in a partial response. Adverse events such as grade 1-2 abdominal pain, general fatigue, and the resultant deterioration of ADL led to discontinuation of chemotherapy. The residual liver metastasis was treated with RFA therapy, causing it to disappear completely. Serum CEA level was 5.5 ng/mL postoperatively, elevated to 13.9 ng/mL at the time of recurrence and 2.4 ng/mL after XP and RFA therapy. He is doing well without any recurrence 2 years and 6 months later.

[A Case of Pancreatic Cancer with Multiple Liver Metastases That Developed Postoperatively and Showed a Complete Response with S-1 Monotherapy].

We encountered a case of pancreatic cancer with multiple liver metastases that developed postoperatively and showed a complete response with S-1 monotherapy for a long time. A pancreaticoduodenectomy was successfully performed on an 80- year-old man. Multiple liver metastases developed 6 months postoperatively. Microscopically, the primary lesion was diagnosed as adenosquamous carcinoma with anaplastic carcinoma component, and the final diagnosis was considered to be Stage Ⅲ disease. S-1monotherapy (80 mg/day, administered for 4 weeks and then stopped for 2-weeks) was effective. A partial response was noted after 3 months, and 9 months after the initial administration of S-1, a complete response was achieved, which persisted for more than 12 months, according to contrast-enhanced CT evaluations.Serum CEA and CA19-9 levels, which became slightly elevated at the time of liver metastasis development, normalized promptly and remained within normal limits. Adverse effects of chemotherapy of more than grade 2 severity were not apparent, and the patient tolerated the 11th course of S-1 administration, consistently. A standard therapeutic strategy and its outcomes in cases of pancreatic cancer recurrence are not clearly outlined in the Japanese Guideline for the Treatment of Pancreatic Cancer. A case of pancreatic cancer with multiple liver metastases that developed postoperatively and showed a complete response with S-1 monotherapy is reported in this paper.

[A Case of Unresectable Rectal Cancer Associated with Hemorrhage of the Primary Tumor after Chemotherapy].

A 47-year-old man visited our hospital with complaints of abdominal pain and hematuria.He was diagnosed with unresectable rectal cancer invading the urinary bladder with multiple liver metastases. Systemic chemotherapy with mFOLFOX6 and panitumumab was started soon after sigmoid colostomy. Three months later, both the primary tumor and the liver metastases had partially responded. Another 2 months later, he complained of terrible abdominal pain. CT images revealed a huge primary tumor and hemorrhage in the sigmoid mesocolon occupying the pelvic cavity. A salvage operation was performed and the primary tumor was palliatively resected. Soon after the operation, a local recurrence appeared and grew rapidly. He died 8 months after diagnosis. Rapid growth of the primary tumor seemed a limiting factor for the prognosis.

[A Case of Recurrence of Rectal Cancer with Para-Aortic Lymph Node Metastases Successfully Resected Resulting in Long Term Survival].

Laparoscopy-assisted low anterior resection (Japanese D3 lymph node dissection) was performed to treat a 68-year-old man for rectal cancer. Microscopically, the resected specimen was diagnosed as a moderately differentiated adenocarcinoma and the final stage was considered as pT3, pN1, cM0, pStage Ⅲa. He was administered capecitabine for 6 months as adjuvant chemotherapy. Then, enlarged para-aortic lymph nodes, indicated by follow up CT at 1 year and 11 months postoperatively developed behind the left renal artery. FDG accumulated in it, consistent with the CT images. Para-aortic lymph node dissection was performed after the diagnosis of solitary lymph node metastases. Microscopically, the resected lymph nodes showed features similar to the primary lesion. He is doing well without recurrence for 4 year and 6 months, without any adjuvant chemotherapy. Para-aortic lymph node metastases are frequently associated with other distant metastases; if not, a complete cure may be possible by curative resection for solitary metastases.

Hydrophilic interaction chromatography using a meter-scale monolithic silica capillary column for proteomics LC-MS.

A meter-scale monolithic silica capillary column modified with urea-functional groups for hydrophilic interaction liquid chromatography (HILIC) was developed for highly efficient separation of biological compounds. We prepared a ureidopropylsilylated monolithic silica capillary column with a minimum plate height of 12 µm for nucleosides and a permeability of 2.1 × 10(-13) m(2), which is comparable with the parameters of monolithic silica-C18 capillary columns. Over 300,000 theoretical plates were experimentally obtained in HILIC with a 4 m long column at 8 MPa; this is the best result yet reported for HILIC. A 2 m long ureidopropylsilylated monolithic silica capillary column was utilized to develop a HILIC mode LC-MS system for proteomics applications. Using tryptic peptides from human HeLa cell lysate proteins, we identified the comparable numbers of peptides and proteins in HILIC with those in reversed-phase liquid chromatography (RPLC) using a C18-modified monolithic silica column when shallow gradients were applied. In addition, approximately 5-fold increase in the peak response on average was observed in HILIC for commonly identified tryptic peptides due to the high acetonitrile concentration in the HILIC mobile phase. Since HILIC mode LC-MS shows orthogonal selectivity to RPLC mode LC-MS, it is useful as a complementary tool to increase proteome coverage in proteomics studies.

[A case of locally advanced rectal carcinoma treated with preoperative chemoradiotherapy resulting in pathologically complete response].

An 84-year-old woman presented with the chief complaint of melena. Colonoscopy revealed a type 2 tumor that circumferentially occupied the lumen of the lower rectum about 6 cm from the anal verge. A biopsy specimen was obtained from the tumor and the patient was diagnosed with moderately differentiated adenocarcinoma. Computed tomography revealed that the rectal cancer had invaded the marginal fatty tissue, accompanied by several regional lymph node metastases with no distant metastasis. On the basis of this evidence, the tumor was staged as cT4a, cN2b, cM0 according to the TNM Classification of Malignant Tumors (7th Edition, UICC). Preoperative radiotherapy combined with an oral chemopreventive agent (RT 1.8 Gy × 25 frames; total 45 Gy, S-1 80 mg/day) was administered with trivial adverse effects. Laparoscopy-assisted low anterior resection with Japanese D3 dissection was performed successfully. The patient is doing well without recurrence after 14 months of surgery. Histological examination revealed that both the primary lesion and regional lymph nodes had no residual cancer; that is, the histological effect of the preoperative chemoradiotherapy was a pathologically complete response (pCR).

[A case of colon cancer with multiple liver metastases showing a long-term response following first-line therapy].

A 71-year-old man presented with sigmoid colon cancer and multiple unresectable liver metastases. As the sigmoid colon cancer caused anemia, we performed laparoscopic-assisted sigmoidectomy prior to the administration of systemic chemotherapy. Bevacizumab (Bv) plus modified Leucovorin, 5-fluorouracil, and oxaliplatin (mFOLFOX6) was administered as first line therapy.At 3 months from the start of chemotherapy, computed tomography revealed that the size of the liver metastases reduced by 49.45%, as evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1). The only adverse event observed was Grade 1 peripheral neuropathy after the eighth dose of oxaliplatin.As the progression of peripheral neuropathy was observed at the ninth dose of oxaliplatin, oxaliplatin was omitted from further therapy; the patient was converted to maintenance therapy with simplified biweekly Leucovorin and fluorouracil (sLV5FU2). Bv plus mFOLFOX6 followed by sLV5FU2 for first-line therapy was effective for disease management over 23 months, but a partial response (PR) was the best overall response achieved.

Atomic origins of the high catalytic activity of nanoporous gold.

Distinct from inert bulk gold, nanoparticulate gold has been found to possess remarkable catalytic activity towards oxidation reactions. The catalytic performance of nanoparticulate gold strongly depends on size and support, and catalytic activity usually cannot be observed at characteristic sizes larger than 5 nm. Interestingly, significant catalytic activity can be retained in dealloyed nanoporous gold (NPG) even when its feature lengths are larger than 30 nm. Here we report atomic insights of the NPG catalysis, characterized by spherical-aberration-corrected transmission electron microscopy (TEM) and environmental TEM. A high density of atomic steps and kinks is observed on the curved surfaces of NPG, comparable to 3-5 nm nanoparticles, which are stabilized by hyperboloid-like gold ligaments. In situ TEM observations provide compelling evidence that the surface defects are active sites for the catalytic oxidation of CO and residual Ag stabilizes the atomic steps by suppressing {111} faceting kinetics.

Measuring the orbital angular momentum of electron vortex beams using a forked grating.

The present study experimentally examines how an electron vortex beam with orbital angular momentum (OAM) undergoes diffraction through a forked grating. The nth-order diffracted electron vortex beam after passing through a forked grating with a Burgers vector of 1 shows an OAM transfer of nℏ. Hence, the diffraction patterns become mirror asymmetric owing to the size difference between the electron beams. Such a forked grating, when used in combination with a pinhole located at the diffraction plane, could act as an analyzer to measure the OAM of input electrons.