Surface terminations control charge transfer from bulk to surface states in topological insulators.

Topological insulators (TI) hold significant potential for various electronic and optoelectronic devices that rely on the Dirac surface state (DSS), including spintronic and thermoelectric devices, as well as terahertz detectors. The behavior of electrons within the DSS plays a pivotal role in the performance of such devices. It is expected that DSS appear on a surface of three dimensional(3D) TI by mechanical exfoliation. However, it is not always the case that the surface terminating atomic configuration and corresponding band structures are homogeneous. In order to investigate the impact of surface terminating atomic configurations on electron dynamics, we meticulously examined the electron dynamics at the exfoliated surface of a crystalline 3D TI (Bi 2 Se 3 ) with time, space, and energy resolutions. Based on our comprehensive band structure calculations, we found that on one of the Se-terminated surfaces, DSS is located within the bulk band gap, with no other surface states manifesting within this region. On this particular surface, photoexcited electrons within the conduction band effectively relax towards DSS and tend to linger at the Dirac point for extended periods of time. It is worth emphasizing that these distinct characteristics of DSS are exclusively observed on this particular surface.

Antidiabetic Effect of Urolithin A in Cultured L6 Myotubes and Type 2 Diabetic Model KK-Ay/Ta Mice with Glucose Intolerance.

Diabetes is caused by abnormal glucose metabolism, and muscle, the largest tissue in the human body, is largely involved. Urolithin A (UroA) is a major intestinal and microbial metabolite of ellagic acid and ellagitannins and is found in fruits such as strawberry and pomegranate. In this present study, we investigated the antidiabetic effects of UroA in L6 myotubes and in KK-Ay/Ta, a mouse model of type 2 diabetes (T2D). UroA treatment elevated the glucose uptake (GU) of L6 myotubes in the absence of insulin. This elevation in GU by UroA treatment was partially inhibited by the concurrent addition of LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K) which activates Akt (PKB: protein kinase B) or Compound C, an inhibitor of 5'-adenosine monophosphate-activated protein kinase (AMPK). Moreover, UroA was found to activate both pathways of Akt and AMPK, and then to promote translocation of glucose transporter 4 (GLUT4) from the cytosol to the plasma membrane in L6 myotubes. Based on these in vitro findings, an intraperitoneal glucose tolerance test (IPGTT) was performed after the oral administration of UroA for 3 weeks to KK-Ay/Ta mice with glucose intolerance. UroA was demonstrated to alleviate glucose intolerance. These results suggest that UroA is a biofactor with antihyperglycemic effects in the T2D state.

Collective bending motion of a two-dimensionally correlated bowl-stacked columnar liquid crystalline assembly under a shear force.

Stacked teacups inspired the idea that columnar assemblies of stacked bowl-shaped molecules may exhibit a unique dynamic behavior, unlike usual assemblies of planar disc- and rod-shaped molecules. On the basis of the molecular design concept for creating higher-order discotic liquid crystals, found in our group, we synthesized a sumanene derivative with octyloxycarbonyl side chains. This molecule forms an ordered hexagonal columnar mesophase, but unexpectedly, the columnar assembly is very soft, similar to sugar syrup. It displays, upon application of a shear force on solid substrates, a flexible bending motion with continuous angle variations of bowl-stacked columns while preserving the two-dimensional hexagonal order. In general, alignment control of higher-order liquid crystals is difficult to achieve due to their high viscosity. The present system that brings together higher structural order and mechanical softness will spark interest in bowl-shaped molecules as a component for developing higher-order liquid crystals with unique mechanical and stimuli-responsive properties.

Atomic-scale observation of solvent reorganization influencing photoinduced structural dynamics in a copper complex photosensitizer.

Photochemical reactions in solution are governed by a complex interplay between transient intramolecular electronic and nuclear structural changes and accompanying solvent rearrangements. State-of-the-art time-resolved X-ray solution scattering has emerged in the last decade as a powerful technique to observe solute and solvent motions in real time. However, disentangling solute and solvent dynamics and how they mutually influence each other remains challenging. Here, we simultaneously measure femtosecond X-ray emission and scattering to track both the intramolecular and solvation structural dynamics following photoexcitation of a solvated copper photosensitizer. Quantitative analysis assisted by molecular dynamics simulations reveals a two-step ligand flattening strongly coupled to the solvent reorganization, which conventional optical methods could not discern. First, a ballistic flattening triggers coherent motions of surrounding acetonitrile molecules. In turn, the approach of acetonitrile molecules to the copper atom mediates the decay of intramolecular coherent vibrations and induces a further ligand flattening. These direct structural insights reveal that photoinduced solute and solvent motions can be intimately intertwined, explaining how the key initial steps of light harvesting are affected by the solvent on the atomic time and length scale. Ultimately, this work takes a step forward in understanding the microscopic mechanisms of the bidirectional influence between transient solvent reorganization and photoinduced solute structural dynamics.

Extracting Kinetics and Thermodynamics of Molecules without Heavy Atoms via Time-Resolved Solvent Scattering Signals.

Time-resolved X-ray liquidography (TRXL) has emerged as a powerful technique for studying the structural dynamics of small molecules and macromolecules in liquid solutions. However, TRXL has limited sensitivity for small molecules containing light atoms only, whose signal has lower contrast compared with the signal from solvent molecules. Here, we present an alternative approach to bypass this limitation by detecting the change in solvent temperature resulting from a photoinduced reaction. Specifically, we analyzed the heat dynamics of TRXL data obtained from p-hydroxyphenacyl diethyl phosphate (HPDP). This analysis enabled us to experimentally determine the number of intermediates and their respective enthalpy changes, which can be compared to theoretical enthalpies to identify the intermediates. This work demonstrates that TRXL can be used to uncover the kinetics and reaction pathways for small molecules without heavy atoms even if the scattering signal from the solute molecules is buried under the strong solvent scattering signal.

Operando time-resolved soft x-ray absorption spectroscopy for photoexcitation processes of metal complexes in solutions.

Operando time-resolved soft x-ray absorption spectroscopy (TR-SXAS) is an effective method to reveal the photochemical processes of metal complexes in solutions. In this study, we have developed the TR-SXAS measurement system for observing various photochemical reactions in solutions by the combination of laser pump pulses with soft x-ray probe pulses from the synchrotron radiation. For the evaluation of the developed TR-SXAS system, we have measured nitrogen K-edge x-ray absorption spectroscopy (XAS) spectra of aqueous iron phenanthroline solutions during a photoinduced spin transition process. The decay process of the high spin state to the low spin state in the iron complex has been obtained from the ligand side by N K-edge XAS, and the time constant is close to that obtained from the central metal side by time-resolved Fe K-edge XAS in the previous studies.

Analysis of the risk factors for osteoporosis and its prevalence after gastrectomy for gastric cancer in older patients: a prospective study.

PURPOSE: Osteoporosis leads to fragility fractures and is a major public health problem. We conducted this study to analyze the prevalence of and risk factors for osteoporosis after gastrectomy in older patients. METHODS: This multicenter prospective trial comprised older patients without recurrence of gastric cancer for > 3 years after curative surgery. The prevalence of osteoporosis was identified using the World Health Organization bone mineral density (BMD)-based definition. Univariate and multivariate analyses were performed to identify the risk factors for osteoporosis. RESULTS: BMD values were measured in 267 of the 271 enrolled patients. The prevalence of osteoporosis was 38.2% (men 24.0%; women 60%). Analysis using FRAX® revealed that 51.7% of patients were candidates for pharmacologic therapy. Female sex (odds ratio [OR] 5.16, 95% confidence interval [CI] 2.61-10.2), age (OR 1.06, 95% CI 1.00-1.12), low body mass index (< 19.0 kg/m2) after gastrectomy (OR 5.31, 95% CI 2.79-10.13), and history of fracture (OR 2.06, 95% CI 1.06-4.02) were independently associated with osteoporosis. CONCLUSIONS: The prevalence of osteoporosis in older patients after gastrectomy was 38.2%. Moreover, female sex, age, low body mass index after gastrectomy, and a history of fracture were risk factors significantly associated with osteoporosis. Thus, older patients undergoing gastrectomy should have proactive surveillance and receive treatment for osteoporosis.

[A Case of Primary Liver Cancer and Gastric Glomus Tumor Diagnosed Preoperatively and Treated with Liver Segmentectomy and Local Gastrectomy].

A man in his 70s was concurrently suspected of having a submucosal tumor(SMT)of the stomach and a liver tumor during a medical examination. Abdominal contrast-enhanced CT scan revealed S8 hepatocellular carcinoma(HCC)and an SMT of the stomach, which was strongly enhanced from the early to the later phase. Upper gastrointestinal endoscopy revealed a 20 mm SMT in the antrum of the stomach. Endoscopic ultrasonography showed a hyperechoic tumor in the fourth layer of the gastric wall. T2-weighted MRI showed a 25 mm SMT in the antrum of the stomach with a faint high signal intensity compared with that of the gastric wall. The patient was diagnosed with HCC and gastric glomus tumor, and a liver segmentectomy and a local gastrectomy were performed. Immunohistochemistry of the SMT revealed the expression of α-SMA but no expression of desmin, c-kit, CD34, or S-100. Therefore, a diagnosis of a Glomus tumor of the stomach was made. Gastric Glomus tumors are very rare; therefore, we have reviewed some citations and would like to discuss our case.

[A Case of Small Thymic Carcinoma with Pleural Dissemination Preoperatively Suspected as Pulmonary Metastasis from Rectal Cancer].

A case was 73-year-old man, who had history of laparoscopic high anterior resection surgery for rectal cancer, followed by adjuvant chemotherapy 2 years ago. Preoperative diagnosis was anterior mediastinal tumor, with multiple intrapulmonary nodules noted, though no increasing tendency. During adjuvant chemotherapy for colorectal cancer, the anterior mediastinal tumor showed some shrinkage, while that and 3 intrapulmonary nodules slowly increased in size after completion, thus rectal cancer pulmonary and mediastinal metastasis were suspected. Complete resection of the intrapulmonary nodules and anterior mediastinal tumor was considered feasible. Thoracoscopic observation revealed multiple small pleural seeding lesions and all speculated to be intrapulmonary metastases before surgery were also pleural lesions. Intraoperative rapid diagnostic findings of a biopsy section revealed possible colorectal cancer metastasis, though histological type was not revealed. Final histopathological diagnosis was pleural dissemination of thymic carcinoma. Lenvatinib was introduced 2 months later for thymic carcinoma with pleural dissemination. Two years after surgery, the anterior mediastinum primary tumor had slightly decreased and the pleural nodules also showed a shrinking tendency. In such cases of small tumor with increasing tendency and irregular margins, thymic carcinoma should be considered when planning treatment.

Trial Analysis of the Relationship between Taste and Biological Information Obtained While Eating Strawberries for Sensory Evaluation.

This paper presents a trial analysis of the relationship between taste and biological information obtained while eating strawberries (for a sensory evaluation). This study used the visual analog scale (VAS); we collected questionnaires used in previous studies and human brain activity obtained while eating strawberries. In our analysis, we assumed that brain activity is highly correlated with taste. Then, the relationships between brain activity and other data, such as VAS and questionnaires, could be analyzed through a canonical correlation analysis, which is a multivariate analysis. Through an analysis of brain activity, the potential relationship with "taste" (that is not revealed by the initial simple correlation analysis) can be discovered. This is the main contribution of this study. In the experiments, we discovered the potential relationship between cultural factors (in the questionnaires) and taste. We also found a strong relationship between taste and individual information. In particular, the analysis of cross-loading between brain activity and individual information suggests that acidity and the sugar-to-acid ratio are related to taste.

Design of discotic liquid crystal enabling complete switching along with memory of homeotropic and homogeneous alignment over a large area.

The alignment control of discotic columnar liquid crystals (LCs), featuring a low motility of the constituent molecules and thus having a large viscosity, is a challenging task. Here we show that triphenylene hexacarboxylic ester, when functionalized with hybrid side chains consisting of alkyl and perfluoroalkyl groups in an appropriate ratio, gives a hexagonal columnar (Colh) LC capable of selectively forming large-area uniform homeotropic or homogeneous alignments, upon cooling from its isotropic melt or upon application of a shear force at its LC temperature, respectively. In addition to the alignment switching ability, each alignment state remains persistent unless the LC is heated to its melting temperature. In situ X-ray diffraction analysis under the application of a shear force, together with polarized optical microscopy observations, revealed how the columnar assembly is changed during the alignment-switching process. The remarkable behavior of the discotic LC is discussed in terms of its rheological properties.

Unveiling ultrafast dynamics in bridged bimetallic complexes using optical and X-ray transient absorption spectroscopies.

In photosynthetic systems employing multiple transition metal centers, the properties of charge-transfer states are tuned by the coupling between metal centers. Here, we use ultrafast optical and X-ray spectroscopies to elucidate the effects of metal-metal interactions in a bimetallic tetrapyridophenazine-bridged Os(ii)/Cu(i) complex. Despite having an appropriate driving force for Os-to-Cu hole transfer in the Os(ii) moiety excited state, no such charge transfer was observed. However, excited-state coupling between the metal centers is present, evidenced by variations in the Os MLCT lifetime depending on the identity of the opposite metal center. This coupling results in concerted coherent vibrations appearing in the relaxation kinetics of the MLCT states for both Cu and Os centers. These vibrations are dominated by metal-ligand contraction at the Cu/Os centers, which are in-phase and linked through the conjugated bridging ligand. This study shows how vibronic coupling between transition metal centers affects the ultrafast dynamics in bridged, multi-metallic systems from the earliest times after photoexcitation to excited-state decay, presenting avenues for tuning charge-transfer states through judicious choice of metal/ligand groups.

[A Case of Hypertrophic Pulmonary Osteoarthropathy Associated with Pulmonary Pleomorphic Carcinoma].

Hypertrophic pulmonary osteoarthropathy(HPO)is a tumor-associated syndrome that features the triad of clubbed fingers, periosteal bone growth in long bones, and arthritis, and is often associated with an adenocarcinoma or squamous cell carcinoma. This report presents details of a case of HPO associated with pleomorphic carcinoma, which was relieved by treatment. A 47-year-old woman was presented with a complaint of generalized arthralgia. A physical examination showed swollen joints in the body and clubbed fingers. Chest CT revealed a mass shadow in the left upper lobe and ultrasound- guided biopsy findings led to a diagnosis of non-small cell lung cancer. Furthermore, bone scintigraphy indicated symmetrical accumulation in bones and joints throughout the body. A right upper lobectomy was performed along with combined chest wall resection and mediastinal lymph node dissection with an open chest, and the presence of lung cancer complicated with HPO was indicated. Pathological examination results revealed a diagnosis of pleomorphic carcinoma(pT4N0M0, Stage ⅢA). Systemic arthralgia was resolved on the first postoperative day. One year after surgery, a solitary brain metastasis developed and was removed, with no recurrence at the time of writing. Joint symptoms related to HPO can be expected to improve with treatment of pulmonary lesions, thus aggressive procedures for diagnosis and treatment are desirable.

The Association of Thymidine Phosphorylase with Gastric Cancer Prognosis.

BACKGROUND: Thymidine phosphorylase(TP)plays an important role in angiogenesis and solid tumor invasion. This study aimed to investigate TP expression in gastric cancer(GC), its correlation with clinicopathological features, and its prognostic significance. METHODS: Clinical data and tumor specimens were retrospectively collected from patients with GC in Ikeda Municipal Hospital between January 2005 and December 2006. Tumor specimens were immunohistochemically analyzed for TP expression graded as 0, 1+, 2+, or 3+ and divided into low(0/1+)and high(2+/3+)TP expression groups. To determine its potential prognostic value, any correlation between TP expression and the clinicopathological features of the patients was statistically assessed. RESULTS: Among 111 patients with GC, 33 had high TP expression(29.7%)and 78 had low TP expression(70.3%). There were significant differences in tumor size, tumor depth, venous invasion, lymphatic invasion, and clinical stage between the two groups. Analysis of the Kaplan-Meier survival curves revealed that the high TP group had significantly shorter overall survival(OS; p<0.01)and progression-free survival(PFS; p<0.01)than the low TP group. Moreover, the high TP group had significantly shorter OS(p=0.040)and a trend toward a shorter PFS(p=0.064) than the low TP group in patients with stage Ⅱ, Ⅲ, and Ⅳ cancer. Multivariate analysis revealed that high TP expression was significantly associated with tumor size, tumor type, and lymphatic invasion in patients with GC. CONCLUSIONS: Our results suggest that high TP expression might predict poor prognosis in GC.

[Two Cases of Recurrent Colon Cancer with BRAF Mutation].

We report 2 cases of recurrent colon cancer with BRAF mutation. Case 1, a 75-year-old man, had rapid progress of multiple liver metastasis 5 months after curative resection, and died on 37 days after recurrence without induction of systemic therapy. Case 2, a 67-year-old man with diagnosis of peritoneal dissemination at 8 months after curative resection, received encorafenb and cetuximab (doublet-therapy) with certain effect, nevertheless advanced triplet-therapy with binimetinib was forced to pause due to severe skin disorders and he died on 123 days after recurrence. We considered that closed follow- up should be required after curatively resected colorectal cancers with BRAF mutation for early detection of recurrence, and prompt induction and evaluation of systemic treatment also should be required after unresectable recurrence including careful management with the attention to the features of doublet and triplet-therapy.

Mechanism of H+ dissociation-induced O-O bond formation via intramolecular coupling of vicinal hydroxo ligands on low-valent Ru(III) centers.

The understanding of O-O bond formation is of great importance for revealing the mechanism of water oxidation in photosynthesis and for developing efficient catalysts for water oxidation in artificial photosynthesis. The chemical oxidation of the RuII2(OH)(OH2) core with the vicinal OH and OH2 ligands was spectroscopically and theoretically investigated to provide a mechanistic insight into the O-O bond formation in the core. We demonstrate O-O bond formation at the low-valent RuIII2(OH) core with the vicinal OH ligands to form the RuII2(µ-OOH) core with a µ-OOH bridge. The O-O bond formation is induced by deprotonation of one of the OH ligands of RuIII2(OH)2 via intramolecular coupling of the OH and deprotonated O- ligands, conjugated with two-electron transfer from two RuIII centers to their ligands. The intersystem crossing between singlet and triple states of RuII2(µ-OOH) is easily switched by exchange of H+ between the µ-OOH bridge and the auxiliary backbone ligand.

Utility of monthly minodronate for osteoporosis after gastrectomy: Prospective multicenter randomized controlled trials.

AIM: Osteoporosis in patients after gastrectomy is increasing with the aging of gastric cancer patients. Bisphosphonates are effective treatments for osteoporosis; however, their safety or efficacy in postgastrectomy patients has not been established. The purpose of this multicenter prospective intervention study was to investigate the impact of monthly minodronate on osteoporosis after gastrectomy. METHODS: Of the 261 enrolled gastric cancer patients, 164 patients were diagnosed with osteoporosis based on criteria of the Japan Society of Osteoporosis. They were randomly assigned 1:1 to groups treated with active vitamin D (VD group) or monthly minodronate (MIN group). The primary endpoint was changes in lumbar bone mineral density (L-BMD) 12 mo after the start of administration. The secondary endpoints were changes in bone metabolism markers, adverse events (AEs), or treatment completion rates. RESULTS: There was no significant difference in patient background between the VD (n = 82) and MIN (n = 82) groups. In the MIN group, the increase in L-BMD was significantly higher than that in the VD group (4.52% vs 1.72%, P = .001), with a significant reduction in bone metabolism markers; blood NTX (-25.6% vs -1.6%, P < .01) and serum bone-specific alkaline phosphatase (-34.3% vs -20.1%, P < .01). AEs were observed in 26.8% and 9.3% of the patients and treatment completion rates were 77.5% and 89.3% in the MIN and VD groups, respectively. Serious AEs were not observed in either group. CONCLUSION: This study demonstrated the safety and efficacy of monthly minodronate, suggesting that this treatment may be useful for osteoporosis after gastrectomy (UMIN000015517).

Antidiabetic Effect of Taxifolin in Cultured L6 Myotubes and Type 2 Diabetic Model KK-Ay/Ta Mice with Hyperglycemia and Hyperuricemia.

Muscle is the largest tissue in our body and plays an important role in glucose homeostasis and hence diabetes. In the present study, we examined the effects of taxifolin (TXF) on glucose metabolism in cultured L6 muscle cells (myotubes) and in type 2 diabetic (T2D) model KK-Ay/Ta mice. TXF dose-dependently increased glucose uptake (GU) in L6 myotubes under the condition of insulin absence. This increase in GU was partially, but significantly canceled by TXF treatment in combination with either LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K), which phosphorylates protein kinase B (Akt) or Compound C, an inhibitor of 5'-adenosine monophosphate-activated protein kinase (AMPK). Furthermore, TXF was demonstrated to activate (=phosphorylate) both Akt and AMPK, and promote glucose transporter 4 (GLUT4) translocation to the plasma membrane from cytosol of L6 myotubes via both PI3K/Akt and AMPK signaling pathways. Based on these in vitro findings, we conducted an in vivo experiment in KK-Ay/Ta mice with hyperglycemia and hyperuricemia. Fasting plasma glucose, insulin, uric acid levels and an index of insulin resistance (HOMA-IR) increased significantly in the T2D model mice compared with normal ones. Such rises in the T2D state were significantly suppressed by oral administration of TXF for four weeks. These results suggest that TXF is a potent antihyperglycemic and antihyperuricemic phytochemical in the T2D state.

Structural Dynamics of C2F4I2 in Cyclohexane Studied via Time-Resolved X-ray Liquidography.

The halogen elimination of 1,2-diiodoethane (C2H4I2) and 1,2-diiodotetrafluoroethane (C2F4I2) serves as a model reaction for investigating the influence of fluorination on reaction dynamics and solute-solvent interactions in solution-phase reactions. While the kinetics and reaction pathways of the halogen elimination reaction of C2H4I2 were reported to vary substantially depending on the solvent, the solvent effects on the photodissociation of C2F4I2 remain to be explored, as its reaction dynamics have only been studied in methanol. Here, to investigate the solvent dependence, we conducted a time-resolved X-ray liquidography (TRXL) experiment on C2F4I2 in cyclohexane. The data revealed that (ⅰ) the solvent dependence of the photoreaction of C2F4I2 is not as strong as that observed for C2H4I2, and (ⅱ) the nongeminate recombination leading to the formation of I2 is slower in cyclohexane than in methanol. We also show that the molecular structures of the relevant species determined from the structural analysis of TRXL data provide an excellent benchmark for DFT calculations, especially for investigating the relevance of exchange-correlation functionals used for the structural optimization of haloalkanes. This study demonstrates that TRXL is a powerful technique to study solvent dependence in the solution phase.