Emergent Spin-Gapped Magnetization Plateaus in a Spin-1/2 Perfect Kagome Antiferromagnet.

The two-dimensional spin-1/2 kagome Heisenberg antiferromagnet is believed to host quantum spin liquid (QSL) states with no magnetic order, but its ground state remains largely elusive. An important outstanding question concerns the presence or absence of the 1/9 magnetization plateau, where exotic quantum states, including topological ones, are expected to emerge. Here we report the magnetization of a recently discovered kagome QSL candidate YCu_{3}(OH)_{6.5}Br_{2.5} up to 57 T. Above 50 T, a clear magnetization plateau at 1/3 of the saturation moment of Cu^{2+} ions is observed, supporting that this material provides an ideal platform for the kagome Heisenberg antiferromagnet. Remarkably, we found another magnetization plateau around 20 T, which is attributed to the 1/9 plateau. The temperature dependence of this plateau reveals the presence of the spin gap. The observation of 1/9 and 1/3 plateaus highlights the emergence of novel states in quantum spin systems.

Multipole polaron in the devil's staircase of CeSb.

Rare-earth intermetallic compounds exhibit rich phenomena induced by the interplay between localized f orbitals and conduction electrons. However, since the energy scale of the crystal-electric-field splitting is only a few millielectronvolts, the nature of the mobile electrons accompanied by collective crystal-electric-field excitations has not been unveiled. Here, we examine the low-energy electronic structures of CeSb through the anomalous magnetostructural transitions below the Néel temperature, ~17 K, termed the 'devil's staircase', using laser angle-resolved photoemission, Raman and neutron scattering spectroscopies. We report another type of electron-boson coupling between mobile electrons and quadrupole crystal-electric-field excitations of the 4f orbitals, which renormalizes the Sb 5p band prominently, yielding a kink at a very low energy (~7 meV). This coupling strength is strong and exhibits anomalous step-like enhancement during the devil's staircase transition, unveiling a new type of quasiparticle, named the 'multipole polaron', comprising a mobile electron dressed with a cloud of the quadrupole crystal-electric-field polarization.

Magnetoconduction in the Correlated Semiconductor FeSi in Ultrastrong Magnetic Fields up to a Semiconductor-to-Metal Transition.

Magnetoresistance of the correlated narrow-gap semiconductor FeSi was investigated by the radio frequency self-resonant spiral coil technique in magnetic fields up to 500 T, which is supplied by an electromagnetic flux compression megagauss generator. Semiconductor-to-metal transition accomplishes around 270 T observed as a sharp kink in the magnetoresistance, which implies the closing of the hybridization gap by the Zeeman shift of band edges. In the temperature-magnetic field phase diagram, the semiconductor-metal transition field is found to be almost independent of temperature, which is in contrast to a characteristic magnetic field associated with the hopping magnetoconduction in the in-gap localized states, exhibiting a notable temperature dependence.

Anisotropic Fully Gapped Superconductivity Possibly Mediated by Charge Fluctuations in a Nondimeric Organic Complex.

We investigate low-temperature electronic properties of the nondimeric organic superconductor ß^{''}-(ET)_{4}[(H_{3}O)Ga(C_{2}O_{4})_{3}]PhNO_{2}. By examining ultrasonic properties, charge disproportionation (CD) without magnetic field dependence is detected below T_{CD}∼8 K just above the superconducting critical temperature T_{c}∼6 K. From quantum oscillations in high fields, we find variation in the Fermi surface and mass enhancement induced by the CD. Heat capacity studies elucidate that the superconducting gap function is fully gapped in the Fermi surface, but anisotropic with fourfold symmetry. We point out that the pairing mechanism of the superconductivity is possibly dominated by charge fluctuations.

Large Enhancement of Thermoelectric Efficiency Due to a Pressure-Induced Lifshitz Transition in SnSe.

The Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and complex magnetism. However, since the observation of Fermi surfaces is generally difficult in the strongly correlated systems, a direct link between the Lifshitz transition and quantum phenomena has been elusive so far. Here, we report a marked impact of the pressure-induced Lifshitz transition on thermoelectric performance for SnSe, a promising thermoelectric material without a strong electron correlation. By applying pressure up to 1.6 GPa, we have observed a large enhancement of the thermoelectric power factor by more than 100% over a wide temperature range (10-300 K). Furthermore, the high carrier mobility enables the detection of quantum oscillations of resistivity, revealing the emergence of new Fermi pockets at ∼0.86 GPa. The observed thermoelectric properties linked to the multivalley band structure are quantitatively reproduced by first-principles calculations, providing novel insight into designing the SnSe-related materials for potential valleytronic as well as thermoelectric applications.

Prognostic factors for survival in patients with pT1 N+ or T2-3 N0 gastric cancer in Japan.

BACKGROUND: The outcome for pT1 N+ or pT2-3 N0 gastric cancer is favourable, but some patients suffer from recurrent disease. The aim of this study was to identify prognostic factors in patients with pT1 N+ or pT2-3 N0 gastric cancer. METHODS: This was a multicentre, retrospective cohort study. All patients with pT1 N+ or pT2-3 N0 gastric cancer who underwent curative gastrectomy at five high-volume, specialized cancer centres in Japan between 2000 and 2008 were included. Demographic, clinical, surgical and pathological data were collected. Independent prognostic factors were identified using a Cox proportional hazards regression model. RESULTS: Some 1442 patients were included. The 5-year overall survival rate for patients with pT1 N+ or pT2-3 N0 gastric cancer was 92·0 per cent. Multivariable analysis for overall survival identified age (hazard ratio (HR) 2·67, 95 per cent c.i. 2·09 to 3·43), sex (HR 0·57, 0·39 to 0·83) and clinical tumour depth (cT) (HR 1·45, 1·06 to 1·98) as independent prognostic factors. CONCLUSION: Survival of patients with pT1 N+ or pT2-3 N0 gastric cancer is good. Age 65 years or above, male sex and cT2-4 category are associated with worse overall survival.

One-Third Magnetization Plateau with a Preceding Novel Phase in Volborthite.

We have synthesized high-quality single crystals of volborthite, a seemingly distorted kagome antiferromagnet, and carried out high-field magnetization measurements up to 74 T and ^{51}V NMR measurements up to 30 T. An extremely wide 1/3 magnetization plateau appears above 28 T and continues over 74 T at 1.4 K, which has not been observed in previous studies using polycrystalline samples. NMR spectra reveal an incommensurate order (most likely a spin-density wave order) below 22 T and a simple spin structure in the plateau phase. Moreover, a novel intermediate phase is found between 23 and 26 T, where the magnetization varies linearly with magnetic field and the NMR spectra indicate an inhomogeneous distribution of the internal magnetic field. This sequence of phases in volborthite bears a striking similarity to those of frustrated spin chains with a ferromagnetic nearest-neighbor coupling J_{1} competing with an antiferromagnetic next-nearest-neighbor coupling J_{2}.

Inguinal hernia repair in patients with artificial urinary sphincter after radical prostatectomy.

PURPOSE: Stress urinary incontinence (UI) often develops after radical prostatectomy for prostate cancer, and in those patients with moderate-to-severe stress UI an artificial urinary sphincter (AUS) is implanted. Inguinal hernias (IHs) often occur after radical prostatectomy. As the prevalence of AUS implantation increases, it is possible to encounter patients with IHs undergoing AUS implantation (IHA). This study investigated our treatment and discussed an appropriate approach for IHAs. METHODS: We retrospectively investigated patients who underwent IH repair with AUS implantation at our hospital from January 2018 to March 2023. We classified IHAs into Types A-D based on the positions of the IHs and AUS devices (the positions of the control pump, pressure-regulating balloon, and connecting tube). The hernia and control pump were ipsilateral in Types A and B, whereas the hernia and pressure-regulating balloon were ipsilateral in Types A and C. RESULTS: This study included 12 IHs of 11 patients. The median patient age was 77 years. We conducted open repair in nine patients with all types and laparoscopic repair in two patients with Type B. The median operation times for unilateral and bilateral repairs were 96 and 182 min, respectively. There were no complications with AUS or hernia surgeries. CONCLUSION: IHA has its own characteristics, and multidisciplinary knowledge thereof will help surgeons safely perform IH surgery.

Face, content and concurrent validity of the Mimic® dV-Trainer for robot-assisted endoscopic surgery: a prospective study.

OBJECTIVE: The aim of this study was to determine whether any correlation exists between the performance of the Mimic® dV-Trainer (Mimic Technologies, Seattle, Wash., USA) and the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, Calif., USA). METHODS: Twelve participants were recruited, ranging from residents to consultants. We used four training tasks, consisting of 'Pick and Place', 'Peg Board', 'Thread the Rings' and 'Suture Sponge', from the software program of the Mimic dV-Trainer. The performance of the participants was recorded and measured. Additionally, we prepared the same tasks for the da Vinci Surgical System. All participants completed the tasks using the da Vinci Surgical System and were assessed according to time, the Objective Structured Assessment of Technical Skill checklist and the global rating score for endoscopic suturing assessed by two independent blinded observers. After performing these tasks, the participants completed a questionnaire that evaluated the Mimic dV-Trainer's face and content validity. The final results for each participant for the Mimic dV-Trainer and the da Vinci Surgical System were compared. RESULTS: All participants ranked the Mimic dV-Trainer as a realistic training platform that is useful for residency training. There was a significant relationship between the Mimic dV-Trainer and the da Vinci Surgical System in all four tasks. We verified the reliability of the assessment of the checklist and the global rating scores for endoscopic suturing assessed by the two blinded observers using Cronbach's alpha test (r = 0.803, 0.891). CONCLUSIONS: We evaluated the concurrent validity of the Mimic dV-Trainer and the da Vinci Surgical System. Our results suggest the possibility that training using the Mimic dV-Trainer may therefore be able to improve the operator's performance during live robot-assisted surgery.

Long-distance polarizing microscope system combined with solenoid-type magnet for microscopy and simultaneous measurement of physical parameters.

We have developed a long-distance polarizing microscope system combined with a solenoid-type superconducting magnet. By inserting an infinity-corrected objective lens into the magnet, direct or polarizing microscope images are observed in magnetic fields of up to 12 T at various temperatures down to 2 K. Through magneto-optical measurements in the transmission geometry, the local magnetization process of a transparent magnet is evaluated in areas of 10 × 10 µm2. This system enables simultaneous measurements of other physical properties over a wide range of temperatures and magnetic fields. The basic principle of the proposed long-distance microscopy can be applied to imaging experiments in various research fields, particularly biology and chemistry.

Disordered ground state and magnetic field-induced long-range order in an S=3/2 antiferromagnetic honeycomb lattice compound Bi3Mn4O12(NO3).

Bi3Mn4O12(NO3), in which the Mn4+ ions carry S=3/2, is the first honeycomb lattice system that shows no long-range magnetic order. Using neutron scattering, we have determined that short-range antiferromagnetic correlations develop at low temperatures. Applied magnetic fields induce a magnetic transition, in which the short-range order abruptly expands into a long-range order.

Renoprotective effects of telmisartan in patients with advanced chronic kidney disease.

BACKGROUND: Angiotensin II receptor blockers (ARBs) provide renoprotective effects in patients with mild-to-moderate chronic kidney disease (CKD). However, there have been few reports regarding whether ARBs show clinical efficacy and safety in patients with advanced CKD. METHODS: Seventy-two hypertensive patients with Stages 3 - 4 CKD receiving no ARBs were enrolled in this study and observed up to 48 months. Telmisartan was added to conventional antihypertensive agents (n = 36, mean estimated glomerular filtration ratio [eGFR] 19.7 ml/min/1.73 m2) whilst the remaining control patients were not treated with ARBs (n = 36, mean eGFR 19.2 ml/min/1.73 m2). Urinary protein excretion, kidney function, and the occurrence of end-stage renal disease requiring renal replacement therapy, hyperkalemia, and death were analyzed. RESULTS: Baseline characteristics of each group were similar. During the observation period, the blood pressures of each group decreased at similar rates. In the telmisartan group, 17 patients (47.2%) were introduced to renal replacement therapy, as compared with 31 patients (86.1%) in the control group (relative risk 0.55, 95% confidence interval 0.19 - 0.92, p < 0.05). Telmisartan significantly reduced proteinuria levels (from 3.47 +/- 3.00 to 2.41 +/- 2.46 g/g . creatinine, p < 0.05) and was associated with a reduction of 49.6% in the decline rate of eGFR. The incidence of major adverse events in both groups was similar. CONCLUSIONS: The addition of telmisartan to conventional antihypertensive therapy is associated with significant improvement in kidney outcome without increased incidence of adverse effects, even in patients with advanced CKD.

Devil's staircase transition of the electronic structures in CeSb.

Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.

Effect of individual fat areas on early surgical outcomes after open gastrectomy for gastric cancer.

BACKGROUND: Obesity is generally considered a risk factor for postoperative morbidity following open gastrectomy. Body mass index (BMI) is widely accepted as an indicator of obesity, but does not necessarily reflect the distribution of fat. It is unclear how different types of fat may affect the operative procedure and outcome. METHODS: The relationship between fat area (total, visceral and subcutaneous fat, and BMI) and early surgical outcomes (bleeding, operating time, morbidity, hospital death and hospital stay) was investigated in 135 patients who had a curative gastrectomy at the Cancer Institute Hospital, Tokyo, in 2006. RESULTS: Postoperative intra-abdominal infection, which occurred in 13 patients (9.6 per cent), correlated strongly with visceral (P = 0.023) and total (P = 0.037) fat area. Visceral fat area also correlated with hospital death (P = 0.041) and a longer hospital stay (P = 0.001). Subcutaneous fat area and BMI did not correlate with these early surgical outcomes. CONCLUSION: Patients with a high visceral fat area are more likely to develop an intra-abdominal infection after gastrectomy. Assessment of fat area, in particular visceral fat area, should alert surgeons to increased postoperative risks.

Novel multiferroic state of Eu1-xYxMnO3 in high magnetic fields.

Magnetic and dielectric properties of Eu1-xYxMnO3 (x=0 and 0.4) are studied in pulsed magnetic fields up to 55 T. For x=0, application of magnetic fields higher than 20 T along the b axis causes magnetic transitions accompanied by generation of electric polarization (P) along the a axis. Similar first-order transitions are also observed in crystals of x=0.4, in which the ground state at zero magnetic field is already a ferroelectric P parallel a phase of different origin. Realistic model calculation indicates the presence of a novel multiferroic state induced by the spin exchange striction mechanism in high magnetic fields as an essential nature of the frustrated Mn spin system in this class of manganites.

Involvement of Rabphilin-3A in cortical granule exocytosis in mouse eggs.

Rabphilin-3A is a putative target protein for Rab3A, a member of the small GTP-binding protein superfamily that has been suggested to play a role in regulated exocytosis in presynapses. In this study we determined the expression and the function of Rabphilin-3A in mouse eggs at fertilization. Rabphilin-3A mRNA and protein were detected by reverse transcriptase-PCR and immunoblot analysis, respectively, in metaphase II mouse eggs. Immunofluorescence analysis showed that Rabphilin-3A protein was distributed in the cortical region in eggs. Sperm induces cortical granule (CG) exocytosis via an increase in cytosolic Ca2+ at fertilization. We microinjected the NH2- or COOH-terminal fragment of recombinant Rabphilin-3A into metaphase II eggs. Neither treatments altered the sperm-induced cytosolic Ca2+ increase, but both inhibited CG exocytosis in a dose-dependent manner. The NH2-terminal fragment was more effective than the COOH-terminal fragment. Full-length Rabphilin-3A did not affect CG exocytosis, but it attenuated the inhibition of CG exocytosis by the NH2-terminal fragment. These results show that Rabphilin-3A is involved in Ca(2+)-dependent CG exocytosis at fertilization in mouse eggs.

Asymmetric catalysis with water: efficient kinetic resolution of terminal epoxides by means of catalytic hydrolysis.

Epoxides are versatile building blocks for organic synthesis. However, terminal epoxides are arguably the most important subclass of these compounds, and no general and practical method exists for their production in enantiomerically pure form. Terminal epoxides are available very inexpensively as racemic mixtures, and kinetic resolution is an attractive strategy for the production of optically active epoxides, given an economical and operationally simple method. Readily accessible synthetic catalysts (chiral cobalt-based salen complexes) have been used for the efficient asymmetric hydrolysis of terminal epoxides. This process uses water as the only reagent, no added solvent, and low loadings of a recyclable catalyst (<0.5 mole percent), and it affords highly valuable terminal epoxides and 1, 2-diols in high yield with high enantiomeric enrichment.

Small-angle synchrotron x-ray scattering reveals distinct shape changes of the myosin head during hydrolysis of ATP.

In the energy transduction of muscle contraction, it is important to know the nature and extent of conformational changes of the head portion of the myosin molecules. In the presence of magnesium adenosine triphosphate (MgATP), fairly large conformational changes of the myosin head [subfragment-1 (S1)] in solution were observed by small-angle x-ray scattering with the use of synchrotron radiation as an intense and stable x-ray source. The presence of MgATP reduced the radius of gyration of the molecule by about 3 angstrom units and the maximum chord length by about 10 angstroms, showing that the shape of S1 becomes more compact or round during hydrolysis of MgATP. Comparison with various nucleotide-bound S1 complexes that correspond to the known intermediate states during ATP hydrolysis indicates that the shape of S1 in a key intermediate state, S1-bound adenosine diphosphate (ADP) and phosphate [S1**.ADP.P(i)], differs significantly from the shape in the other intermediate states of the S1 adenosine triphosphatase cycle as well as that of nucleotide-free S1.

A series of magnon crystals appearing under ultrahigh magnetic fields in a kagomé antiferromagnet.

Geometrical frustration and a high magnetic field are two key factors for realizing unconventional quantum states in magnetic materials. Specifically, conventional magnetic order can potentially be destroyed by competing interactions and may be replaced by an exotic state that is characterized in terms of quasiparticles called magnons, the density and chemical potential of which are controlled by the magnetic field. Here we show that a synthetic copper mineral, Cd-kapellasite, which comprises a kagomé lattice consisting of corner-sharing triangles of spin-1/2 Cu2+ ions, exhibits an unprecedented series of fractional magnetization plateaus in ultrahigh magnetic fields of up to 160 T. We propose that these quantum states can be interpreted as crystallizations of emergent magnons localized on the hexagon of the kagomé lattice.