Inverse-Perovskite Ba3 BO (B = Si and Ge) as a High Performance Environmentally Benign Thermoelectric Material with Low Lattice Thermal Conductivity.

High energy-conversion efficiency (ZT) of thermoelectric materials has been achieved in heavy metal chalcogenides, but the use of toxic Pb or Te is an obstacle for wide applications of thermoelectricity. Here, high ZT is demonstrated in toxic-element free Ba3 BO (B = Si and Ge) with inverse-perovskite structure. The negatively charged B ion contributes to hole transport with long carrier life time, and their highly dispersive bands with multiple valley degeneracy realize both high p-type electronic conductivity and high Seebeck coefficient, resulting in high power factor (PF). In addition, extremely low lattice thermal conductivities (κlat ) 1.0-0.4 W m-1  K-1 at T = 300-600 K are observed in Ba3 BO. Highly distorted O-Ba6 octahedral framework with weak ionic bonds between Ba with large mass and O provides low phonon velocities and strong phonon scattering in Ba3 BO. As a consequence of high PF and low κlat , Ba3 SiO (Ba3 GeO) exhibits rather high ZT = 0.16-0.84 (0.35-0.65) at T = 300-623 K (300-523 K). Finally, based on first-principles carrier and phonon transport calculations, maximum ZT is predicted to be 2.14 for Ba3 SiO and 1.21 for Ba3 GeO at T = 600 K by optimizing hole concentration. Present results propose that inverse-perovskites would be a new platform of environmentally-benign high-ZT thermoelectric materials.

Accumulation mechanisms of radiocaesium within lichen thallus tissues determined by means of in situ microscale localisation observation.

Many lichens are well known to accumulate radiocaesium and, thus acting as biomonitors of contamination levels. However, the actual localisation and chemical forms of radiocaesium in contaminated lichens have not yet been elucidated because, despite their high radioactivity, these forms are present in trace amounts as chemical entities. Here, we use autoradiography and demonstrate for the first time in situ microscale localisation of radiocaesium within thallus tissues to investigate the radiocaesium forms and their accumulation mechanism. Radiocaesium distributions showed similar trends in lichen tissues collected two and six years after the Fukushima nuclear accident. The radiocaesium was localised in the brown pigmented parts i.e., melanin-like substances, in the lower cortex of lichen thallus. Quantum chemical calculations showed that functional group of melanin-like substances can chelate Cs+ ion, which indicates that the Cs+ ions form complexes with the substances. Based on these findings, we suggest that radiocaesium ions may be retained stably in melanin-like substances for long periods (two to six years) due to steric factors, such as those seen in porphyrin-like structures and via multimer formation in the lower cortex. In addition, electron microscopy and autoradiography were used to observe radiocaesium-bearing microparticles (CsMPs) on/in the upper cortex and around the medullary layer. Micron-sized particles appeared to adhere to the surface tissue of the thallus, as shown by electron microscopy, suggesting that the particles were trapped by development of an adhesive layer; that is, CsMPs were trapped both physically and physiologically. These findings provide information on in situ localisation of two chemical forms of radiocaesium, cations and particles, in lichen thallus tissues and their accumulation mechanisms.

Design, Synthesis, and Optoelectronic Properties of the High-Purity Phase in Layered AETMN2 (AE = Sr, Ba; TM = Ti, Zr, Hf) Semiconductors.

We report the synthesis and optoelectronic properties of high phase-purity (>94 mol %) bulk polycrystals of KCoO2-type layered nitrides AETMN2 (AE = Sr, Ba; and TM = Ti, Zr, Hf), which are expected to exhibit unique electron transport properties originating from their natural two-dimensional (2D) electronic structure, but high-purity intrinsic samples have yet been reported. The bulks were synthesized using a solid-state reaction between AENH and TMN precursors with NaN3 to achieve high N chemical potential during the reaction. The AETMN2 bulks are n-type semiconductors with optical band gaps of 1.63 eV for SrTiN2, 1.97 eV for BaZrN2, and 2.17 eV for BaHfN2. SrTiN2 and BaZrN2 bulks show degenerated electron conduction due to the natural high-density electron doping and paramagnetic behavior in all of the temperature ranges examined, while such unintentional carrier generation is largely suppressed in BaHfN2, which exhibits nondegenerated electron conduction. The BaHfN2 sample also exhibits weak ferromagnetic behavior at temperatures lower than 35 K. Density functional theory calculations suggest that the high-density electron carriers in SrTiN2 come from oxygen impurity substitution at the N site (ON) acting as a shallow donor even if the high-N chemical potential synthesis conditions are employed. On the other hand, the formation energy of ON becomes larger in BaHfN2 because of the stronger TM-N chemical bonds. Present results demonstrate that the easiness of impurity incorporation is designed by density functional calculations to produce a more intrinsic semiconductor in wider chemical conditions, opening a way to cultivating novel functional materials that are sensitive to atmospheric impurities and defects.

Association between pretreatment neutrophil-to-lymphocyte ratio and immune-related adverse events due to immune checkpoint inhibitors in patients with non-small cell lung cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced or recurrent non-small cell lung cancer (NSCLC). They cause immune-related adverse events (irAEs), but the underlying mechanisms and predictors remain to be fully elucidated. In this retrospective study, we investigated the association between pretreatment neutrophil-to-lymphocyte ratio (NLR) and the occurrence of irAEs. METHODS: The study involved 115 patients with NSCLC who started ICI-only treatment in our hospital between January 2016 and April 2020. RESULTS: Forty-five patients (39.1%) had irAEs, and pretreatment NLR was significantly lower in the irAEs group than in the non-irAEs group (2.8 vs. 4.1; p = 0.036). The cutoff value of the NLR was 2.86 (area under curve, 0.62; sensitivity, 0.56; specificity, 0.71), and the incidence rate of irAEs was significantly higher in the NLR < 2.86 group than in the NLR ≥2.86 group (p = 0.004; odds ratio [OR]: 3.12; 95% confidence interval [CI]: 1.43-6.84). The multivariate analysis showed that the NLR was significantly associated with the occurrence of irAEs (p = 0.016; OR: 2.69; 95% CI: 1.21-6.01). CONCLUSIONS: Low pretreatment NLR may be a predictive factor for the occurrence of irAEs. By focusing on the potential risk of irAEs in patients with a low pretreatment NLR, irAEs can be appropriately managed from an early period.

X-ray diffraction measurement of a single nanometre-sized particle levitated in air by an optical-trap sample holder.

A single-beam optical-trap sample holder for X-ray diffraction measurements with synchrotron radiation has been developed. The sample holder was used to obtain an X-ray diffraction image of a single ZnO particle levitated in air, without mechanical contact, by the optical gradient force exerted by a focused laser beam. The diffraction image showed a Debye ring pattern, which was similar to a powder diffraction pattern of an assemblage of ZnO particles. While the ZnO particle is held by the optical trap in air, it rotates irregularly. Therefore, the Debye ring pattern of the ZnO particle can be clearly obtained even if the ZnO particle is a single grain. Lattice parameters and crystallite size of the single ZnO particle were determined simultaneously. The lattice parameters were determined to be a = 3.2505 ± 0.0005 Šand c = 5.207 ± 0.006 Å, which are consistent with those of the assemblage of ZnO particles. The crystallite size determined by the Scherrer method was 193.4 ± 26.2 nm.

Extended Polymorphism of Two-Dimensional Material.

When controlling electronic properties of bulk materials, we usually assume that the basic crystal structure is fixed. However, in two-dimensional (2D) materials, atomic structure or polymorph is attracting growing interest as a controlling parameter to functionalize their properties. Various polymorphs can exist in transition metal dichalcogenides (TMDCs) from which 2D materials are generated, and polymorphism has drastic impacts on the electronic states. Here we report the discovery of an unprecedented polymorph of a TMDC 2D material. By mechanical exfoliation, we made thin flakes from a single crystal of 2Ha-type tantalum disulfide (TaS2), a metallic TMDC with a charge-density-wave (CDW) phase. Microbeam X-ray diffraction measurements and electrical transport measurements indicate that thin flakes possess a polymorph different from any one known in TaS2 bulk crystals. Moreover, the flakes with the unique polymorph displayed the dramatically enhanced CDW ordering temperature. The present results suggest the potential existence of diverse structural and electronic phases accessible only in 2D materials.

Development of optical choppers for time-resolved measurements at soft X-ray synchrotron radiation beamlines.

Two types of optical choppers for time-resolved measurements at synchrotron radiation soft X-ray beamlines have been developed. One type uses an air-spindle-type rotation mechanism with a two-stage differential pumping system to maintain the ultra-high vacuum of the X-ray beamline, and the other uses a magnetic bearing. Both can be installed at the soft X-ray beamlines at SPring-8, greatly improving the accessibility of pump-and-probe spectroscopy. The combination of X-ray chopper and pump-and-probe photoemission electron microscope at SPring-8 provides drastic improvements in signal-to-noise ratio and resolution compared with techniques using high-voltage gating of channel plate detectors. The choppers have the capability to be used not only at synchrotron radiation facilities but also at other types of soft X-ray and VUV beamlines.

Tomographic Mapping Analysis in the Depth Direction of High-Ge-Content SiGe Layers with Compositionally Graded Buffers Using Nanobeam X-ray Diffraction.

A high-Ge-content Si1-yGey/compositionally graded Si1-xGex-stacked structure grown on Si(001) is now considered to be an important platform for the realization of advanced nanometer-scale complementary metal oxide semiconductor devices with high-mobility channel materials, such as III-V materials and Ge, and monolithically integrated photonic modules. The performance of such advanced devices is critically influenced by crystalline inhomogeneity in the stacked structure; therefore, precise characterization of the crystallinity is important. In particular, the development of a characterization method not only for in-plane crystallinity but also for in-depth crystallinity is strongly required. This is because the crystalline quality of the constant composition Si1-yGey is sensitively dependent on that of the compositionally graded Si1-xGex layers underneath. Here, we have demonstrated in-depth tomographic mapping of a high-Ge-content Si1-yGey/compositionally graded Si1-xGex-stacked structure using position-dependent ω-2θ map measurement using nanobeam X-ray diffraction. This mapping technique is based on the correspondence of each 2θ value in the ω-2θ map to the lattice constant of stacked layers in the depth direction. Application of the proposed analytical procedure provides tomographic maps of the local variation in lattice plane tilting (VLPT) from the obtained ω-2θ maps. It is quantitatively verified that the local crystallinity in the layer at a certain depth is strongly influenced by that underneath the layer. The correlation between the local VLPT and real structural defects in the stacked structure is also discussed in detail.

Successful Endoscopic Treatment of an Actively Bleeding Jejunal Dieulafoy's Lesion.

Although small bowel endoscopy is commonly performed, cases of ongoing bleeding from small bowel lesions have not been commonly encountered. In the present report, we describe a case of successful endoscopic treatment of an actively bleeding jejunal Dieulafoy's lesion in a 79-year-old man with persistent anemia and melena. Capsule endoscopy indicated active bleeding in the jejunum. Thereafter, double-balloon endoscopy-performed via the oral approach-showed active bleeding from a jejunal Dieulafoy's lesion, which was treated using argon plasma coagulation and hemoclips. The melena subsequently resolved, and the patient's condition improved after the endoscopic treatment.

Controlling charge-density-wave states in nano-thick crystals of 1T-TaS2.

Two-dimensional crystals, especially graphene and transition metal dichalcogenides (TMDs), are attracting growing interests because they provide an ideal platform for novel and unconventional electronic band structures derived by thinning. The thinning may also affect collective phenomena of electrons in interacting electron systems and can lead to exotic states beyond the simple band picture. Here, we report the systematic control of charge-density-wave (CDW) transitions by changing thickness, cooling rate and gate voltage in nano-thick crystals of 1T-type tantalum disulfide (1T-TaS2). Particularly the clear cooling rate dependence, which has never been observed in bulk crystals, revealed the nearly-commensurate CDW state in nano-thick crystals is a super-cooled state. The present results demonstrate that, in the two-dimensional crystals with nanometer thickness, the first-order phase transitions are susceptible to various perturbations, suggestive of potential functions of electronic phase control.

[A case report of hepatocellular carcinoma with metastases to the lip, stomach, and colorectum].

A 79-year-old man was diagnosed with hepatocellular carcinoma in 2000 and treated with partial hepatectomy. Intrahepatic carcinoma recurred with lung metastases 7 years later. Several transcatheter arterial chemoembolizations were performed to treat the recurrence, and a right lower lobectomy was performed for lung metastasis. Twelve years after the original carcinoma diagnosis, lip and lung metastases were detected, and he was hospitalized for radiotherapy of the lung metastasis; an oral molecular-targeting drug was initiated. During the therapy, hematochezia was observed, and a colonoscopy was performed. A submucosal lesion with a blood clot measuring approximately 4mm in diameter was found in the sigmoid colon, and endoscopic mucosal resection was performed. Furthermore, an elevated lesion with a 5-mm diameter recess was observed on upper gastrointestinal endoscopy. Both lesions were diagnosed histopathologically as hepatocellular carcinoma metastases.

Oesophageal cooling with ice water does not reduce the incidence of oesophageal lesions complicating catheter ablation of atrial fibrillation: randomized controlled study.

AIM: Atrial fibrillation (AF) ablation can result in oesophageal injuries that lead to atrio-oesophageal fistulae, a life-threatening complication. This study aimed to evaluate whether oesophageal cooling could prevent oesophageal lesions complicating AF ablation. METHODS AND RESULTS: We randomly assigned 100 patients with drug-resistant AF to an oesophageal cooling group or a control group. In the oesophageal cooling group, we injected 5 mL of ice water into the oesophagus prior to radiofrequency (RF) energy delivery adjacent to the oesophagus. If the oesophageal temperature reached 42°C, the RF energy delivery was stopped, and the ice water injection was repeated. In the control group, oesophageal cooling was not applied. Oesophageal endoscopy was performed 1 day after the catheter ablation, and lesions were qualitatively assessed as mild, moderate, or severe. The numbers of ablation sites with an oesophageal temperature of >42°C were 1.7 ± 1.4 and 2.6 ± 1.7 in the oesophageal cooling group and the control group, respectively (P = 0.04), and the maximal oesophageal temperature at those sites was 43.0 ± 0.6 and 44.7 ± 0.9°C (P < 0.0001). Oesophageal lesions occurred almost equally between the oesophageal cooling group [10 of 50 patients (20%)] and the control group [11 of 50 patients (22%)]. However, the severity of the oesophageal lesions was slightly milder in the oesophageal cooling group (three moderate, seven mild) than in the control group (three severe, one moderate, seven mild). CONCLUSION: Oesophageal cooling may alleviate the severity of oesophageal lesions but does not reduce the incidence of this complication under the specific protocol evaluated here.

System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process.

We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge2Sb2Te5 film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width (ΔE∕E ~ 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge2Sb2Te5 phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge2Sb2Te5 layers on laser power.

Incidence of intussusception as studied from a hospital-based retrospective survey over a 10-year period (2001-2010) in Akita Prefecture, Japan.

One concern about rotavirus vaccines is its possible association with intussusception. Thus, it is necessary to determine the baseline incidence for intussusception in the first year of life in places where rotavirus vaccines are introduced. However, few safety data exist for the period at which the first dose of Rotarix and RotaTeq are allowed to administer in Japan. The first dose of Rotarix is scheduled to administer at 6-20 weeks of age and that of RotaTeq is scheduled to administer at 6-24 weeks of age; the upper limits for these vaccines is later than the upper limit recommended by the World Health Organization by 5 and 9 weeks, respectively. We performed a retrospective cross-sectional study by reviewing medical charts of all hospitals that provided pediatric beds in Akita Prefecture, Japan, and identifying the cases of intussusception that met the Brighton criteria level 1 in these hospitals between January 2001 and December 2010. During this 10-year period, 122 children younger than 1 year of age were diagnosed with intussusception. The incidence of intussusception was estimated at 158 per 100,000 person-years among children younger than 1 year (95% confidence interval, 131-188), 10 per 100,000 person-years for children aged 0-2 months, 165 for children aged 3-5 months, and 300 for children aged 6-8 months. This rapid and substantial increase in the incidence of intussusception during the first year of life should be considered when formulating the immunization schedule for administering rotavirus vaccines in Japan.

STXBP1 mutations in early infantile epileptic encephalopathy with suppression-burst pattern.

PURPOSE: De novo STXBP1 mutations have been found in individuals with early infantile epileptic encephalopathy with suppression-burst pattern (EIEE). Our aim was to delineate the clinical spectrum of subjects with STXBP1 mutations, and to examine their biologic aspects. METHODS: STXBP1 was analyzed in 29 and 54 cases of cryptogenic EIEE and West syndrome, respectively, as a second cohort. RNA splicing was analyzed in lymphoblastoid cells from a subject harboring a c.663 + 5G>A mutation. Expression of STXBP1 protein with missense mutations was examined in neuroblastoma2A cells. RESULTS: A total of seven novel STXBP1 mutations were found in nine EIEE cases, but not in West syndrome. The mutations include two frameshift mutations, three nonsense mutations, a splicing mutation, and a recurrent missense mutation in three unrelated cases. Including our previous data, 10 of 14 individuals (71%) with STXBP1 aberrations had the onset of spasms after 1 month, suggesting relatively later onset of epileptic spasms. Nonsense-mediated mRNA decay associated with abnormal splicing was demonstrated. Transient expression revealed that STXBP1 proteins with missense mutations resulted in degradation in neuroblastoma2A cells. DISCUSSION: Collectively, STXBP1 aberrations can account for about one-third individuals with EIEE (14 of 43). These genetic and biologic data clearly showed that haploinsufficiency of STXBP1 is the important cause for cryptogenic EIEE.

Endoscopic hemostasis of gastric ulcer bleeding by hemostatic forceps coagulation.

Endoscopic submucosal dissection (ESD) for early gastric carcinoma has been widely performed in Japan. In this technique, when hemorrhaging from vessels is observed, the bleeding point is coagulated using hemostatic forceps with the soft coagulation. There have been reports that using hemostatic forceps with soft coagulation is a safe and effective method of controlling upper gastrointestinal ulcer bleeding. However, there have been no reports regarding the comparative effectiveness of hemostatic forceps and clipping in upper gastrointestinal ulcer bleeding. Between April 2003 and December 2008, a total of 124 patients with gastric ulcer bleeding causing melena or hematochezia were treated with endoscopic hemostasis in our hospital. Two endoscopic hemostatic methods were used for different groups of patients: coagulation with hemostatic forceps was used for Group A and clipping was used for Group B. The rate of additional treatment required after the initial procedure was 28.6% (8/28) for Group A and 79.2% (76/96) for Group B, indicating a significantly lower rate for Group A than that for Group B (P < 0.01). Additional treatment consists of a hypertonic saline epinephrine injection. The rebleeding rate was 3.6% (1/28) for Group A and 8.3% (8/96) for Group B, again indicating a lower rate for Group A than for Group B. Finally, successful endoscopic hemostasis was 100% in both groups. Using the soft coagulation mode of hemostatic forceps is shown to be a safe, easy and effective method of controlling gastric ulcer bleeding in relation to clipping.

Liquid-crystal periodic zigzags from geometrical and surface-anchoring-induced confinement: origin and internal structure from mesoscopic scale to molecular level.

We figured out periodic undulations of lamellae "zigzags" in liquid crystals under confinement by glass and patterned silicon hybrid cell, but in the absence of applied fields. The optical and internal structures of zigzags have been investigated from mesoscopic scale to molecular level by convoluting real and reciprocal space probes, such as polarized light microscopy, scanning electron microscopy, and microbeam x-ray diffraction. The homeotropic anchoring happens at air/liquid crystal, while planar one appears at glass or patterned silicon surfaces. The wetting and displacement of lamellae near the glass surface give rise to tilting and bending in the stacking of lamellae. This can provide a solution for the origin of periodic zigzags: asymmetric strain exerted to lamellae at two-dimensional glass surface and one-dimensional-like pattern. This can give a hint for potential photonic applications such as optical gratings and modulators due to its high periodicity.

X-ray diffractometry for the structure determination of a submicrometre single powder grain.

A high-precision diffractometer has been developed for the structure analysis of a submicrometre-scale single grain of a powder sample at the SPring-8 BL40XU undulator beamline. The key design concept is the combination of a stable focused synchrotron radiation beam and the precise axis control of the diffractometer, which allows accurate diffraction intensity data of a submicrometre-scale single powder grain to be measured. The phase zone plate was designed to create a high-flux focused synchrotron radiation beam. A low-eccentric goniometer and high-precision sample positioning stages were adopted to ensure the alignment of a micrometre-scale focused synchrotron radiation beam onto the submicrometre-scale single powder grain. In order to verify the diffractometer performance, the diffraction pattern data of several powder grains of BaTiO(3), of dimensions approximately 600 x 600 x 300 nm, were measured. By identifying the diffraction data set of one single powder grain, the crystal structure was successfully determined with a reliable factor of 5.24%.

Predicting the response to 48-week combination therapy with peginterferon alpha-2b plus ribavirin from the estimated HCV RNA load index after negative serum change in genotype 1b hepatitis C patients.

AIM: We estimated viral dynamics after serum hepatitis C virus (HCV) RNA became negative and assessed the relation between the estimated viral load at the end of treatment (EVE) index and the response to the combination therapy with peginterferon alpha-2b plus ribavirin. METHODS: Patients with chronic HCV, genotype 1b, and a high viral load were treated with this combination therapy for 48 weeks, and serum HCV RNA was measured frequently during the treatment period. In the patients showing an end-of-treatment response (ETR), the viral load profile from the start of treatment until serum HCV RNA became negative was expressed by an approximate curve. Then the EVE index was calculated by using the expression obtained from the curve, and differences between the sustained virologic response (SVR) and relapse groups were investigated. RESULTS: The SVR rate increased as the EVE index became lower, and the EVE index was significantly lower in the SVR group than in the relapse group. The SVR rate was higher for those in whom the EVE index was below the cut-off point. CONCLUSION: Prediction of SVR and relapse from the EVE index is more useful than prediction from viral dynamics at the time when HCV RNA becomes negative or when HCV RNA shows a decrease of 2-log or more.