A theory of the spin-crossover phenomena in the rare earth perovskite LaCoO3induced by temperature or a magnetic field.

Published magnetic data for LaCoO3are successfully analyzed with coexisting5Dand low-spin (LS) cobalt states. Energy levels of the two states are derived in analytic forms. To this end, fictitious orbital angular momentumlof magnitude one defines the Γ5(5D) state. Our Hamiltonian includes the spin-orbit interaction, and a cubic crystal field embellished by a trigonal distortion9B20(lz2-2/3)-80B40(lz2-9/10). A singlet ground state with an energy gap to the first excited doublet is realized for certain values of the parameters. The temperature-independent paramagnetic susceptibility (TIPS) of the5Dstate has a finite value, which accords with the observation. Whereas, TIPS is symmetry forbidden in the LS state. A rigorous calculation is made of the excitation spectrum in the LS state. The elementary excitation is modeled as a creation of an electron-hole pair that results in an energy level scheme in which the first excited quartet lies above the singlet ground state. The electron spin resonance data are successfully equated with transitions within the excited quartet. Available magnetization data delineate parameters in the5DHamiltonian. The temperature dependence of the susceptibility of our coexisting model is qualitatively reasonable. To improve on a quantitative outcome, we are led to introduce a temperature dependent concentration for the5Dand LS states. Calculated Bragg diffraction patterns gathered with x-rays tuned to the CoK-edge reveal potential to refine the current crystal structure and to shed light on the origin of the coexisting states.

Reversal of freshening trend of Antarctic Bottom Water in the Australian-Antarctic Basin during 2010s.

The Antarctic continental margin supplies the densest bottom water to the global abyss. From the late twentieth century, an acceleration in the long-term freshening of Antarctic Bottom Waters (AABW) has been detected in the Australian-Antarctic Basin. Our latest hydrographic observations reveal that, in the late 2010s, the freshening trend has reversed broadly over the continental slope. Near-bottom salinities in 2018-2019 were higher than during 2011-2015. Along 170° E, the salinity increase between 2011 and 2018 was greater than that observed in the west. The layer thickness of the densest AABW increased during the 2010s, suggesting that the Ross Sea Bottom Water intensification was a major source of the salinity increase. Freshwater content on the continental slope decreased at a rate of 58 ± 37 Gt/a in the near-bottom layer. The decadal change is very likely due to changes in Ross Sea shelf water attributable to a decrease in meltwater from West Antarctic ice shelves for the corresponding period.

Bioactive surface modification of Ti-29Nb-13Ta-4.6Zr alloy through alkali solution treatments.

Bioactive surface modification of Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) was performed through three different alkali solution treatments, including the electrochemical (E), hydrothermal (H), and hydrothermal-electrochemical (HE) processes; all of the processes lead to the formation of sodium-contained amorphous titanium oxide layers on TNTZ samples. The TNTZ samples subjected to the E, H, and HE processes exhibit a flat surface, smooth and fine mesh-like structure surface, and rough mesh-like structure surface, respectively. In the bioactive test, namely, simulated body fluid test, apatite inductivity increases as the surface morphology becomes rough. The order of inductivity for the three processes was HE>H>E. The surface chemical composition also affects the apatite induction ability. The surface with fewer niobium species exhibits better apatite inductivity.

Adhesive strength of bioactive oxide layers fabricated on TNTZ alloy by three different alkali-solution treatments.

Bioactive oxide layers were fabricated on Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) by three different alkali solution treatments: hydrothermal (H), electrochemical (E), and hydrothermal-electrochemical (HE). The adhesive strength of the oxide layer to the TNTZ substrate was measured to determine whether this process achieves sufficient adhesive strength for implant materials. Samples subjected to the HE process, in which a current of 15mA/cm(2) was applied at 90°C for 1h (HE90-1h), exhibited a comparatively higher adhesive strength of approximately 18MPa while still maintaining a sufficiently high bioactivity. Based on these results, an oxide layer fabricated on TNTZ by HE90-1h is considered appropriate for practical biomaterial application, though thicker oxide layers with many cracks can lead to a reduced adhesive strength.

Changes in Ocean Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP Global Repeat Hydrography.

Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcing and ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.

Randomized phase III trial of treatment duration for oral uracil and tegafur plus leucovorin as adjuvant chemotherapy for patients with stage IIB/III colon cancer: final results of JFMC33-0502.

BACKGROUND: While adjuvant chemotherapy is preferable for high-risk colon cancer, treatment duration is controversial. Oral uracil and tegafur (UFT)/leucovorin (LV) is widely used as a standard adjuvant chemotherapy for colon cancer in Japan. We conducted a phase III trial to investigate the optimal duration of adjuvant chemotherapy for stage IIB/III colon cancer. PATIENTS AND METHODS: Patients with curatively resected stage IIB/III colon cancer were eligible for enrollment in this trial. Patients were registered within 6 weeks after surgery and were randomly assigned to receive UFT/LV for 28 of 35 days for 6 months in the control group or for 5 consecutive days per week for 18 months in the study group. The primary end point was the disease-free survival (DFS), and the secondary end points were overall survival (OS) and safety. RESULT: A total of 1071 patients were registered from 233 centers. A statistically significant difference in DFS was not observed between the study group and the control group; the 5-year DFS was 69% in the study group and 69% in the control group. The 5-year OS was 85% in the study group and 85% in the control group. CONCLUSION: Eighteen-month treatment with UFT/LV did not improve DFS or OS compared with 6-month UFT/LV treatment in patients with stage IIB/III colon cancer. The important finding from this study is that not 18 months but 6 months of treatment is enough for postoperative UFT/LV for stage IIB/III colon cancer. CLINICAL TRIAL NUMBER: UMIN-CTR C000000245.

Clinical efficacy and safety of monthly oral ibandronate 100 mg versus monthly intravenous ibandronate 1 mg in Japanese patients with primary osteoporosis.

UNLABELLED: The MOVEST study evaluated the efficacy and safety of monthly oral ibandronate versus licensed monthly IV ibandronate in Japanese osteoporotic patients. Relative BMD gains after 12 months were 5.22 % oral and 5.34 % IV, showing non-inferiority of oral to IV ibandronate (primary endpoint). No new safety concerns were identified. INTRODUCTION: The randomized, phase 3, double-blind MOVEST (Monthly Oral VErsus intravenouS ibandronaTe) study evaluated the efficacy and safety of monthly oral ibandronate versus the licensed monthly intravenous (IV) ibandronate regimen in Japanese patients with osteoporosis. METHODS: Ambulatory patients aged ≥ 55 years with primary osteoporosis were randomized to receive oral ibandronate 100 mg/month plus monthly IV placebo, or IV ibandronate 1 mg/month plus monthly oral placebo. The primary endpoint was non-inferiority of oral versus IV ibandronate with respect to bone mineral density (BMD) gains at the lumbar spine after 12 months of treatment. RESULTS: Four hundred twenty-two patients were enrolled with 372 patients in the per-protocol set (183 and 189 in the oral and IV ibandronate groups, respectively). The relative change from baseline in lumbar spine BMD values for the oral and IV ibandronate groups, respectively, was 5.22 % (95 % confidence interval [CI] 4.65, 5.80) and 5.34 % (95 % CI 4.78, 5.90). The least squares mean difference between the two groups was -0.23 % (95 % CI -0.97, 0.51), showing non-inferiority of oral ibandronate to IV ibandronate (non-inferiority limit = -1.60). Changes in BMD values at other sites, and bone turnover marker levels in the oral ibandronate group, were comparable with those of the IV group. The safety profile was similar to that previously demonstrated; no new safety concerns were identified. CONCLUSIONS: This study demonstrated the non-inferiority of oral ibandronate 100 mg/month to IV ibandronate 1 mg/month (licensed dose in Japan) in increasing lumbar spine BMD in Japanese patients with primary osteoporosis.

Analysis of autonomic nerve preservation and pouch reconstruction influencing fragmentation of defecation after sphincter-preserving surgery for rectal cancer.

Our questionnaire survey on defecation disorders after rectal cancer surgery revealed that 66.7% of postoperative patients were most annoyed with fragmentation of defecation. Therefore, we performed a change-over-time analysis on the relationship of fragmentation and factors including location of rectal cancer, surgical technique, anastomosis method, pouch reconstruction, extent of lymph node dissection, and degree of pelvic and colonic nerve preservation surrounding the superior mesenteric artery. The fragmentation decreased over time at the postoperative time points of 6 months, 2 and 5 years. A statistical analysis of factors influencing fragmentation revealed that location of cancer, reconstruction technique, anastomosis method and degree of pelvic nerve preservation were significant factors for the entire patient population and that colonic nerve preservation was a significant factor 5 years after surgery. Analysis of patients with lower rectal cancer only showed that in addition to surgical technique and anastomosis method, pouch reconstruction was effective and autonomic nerve preservation was effective 5 years after surgery. As a result, when the anastomotic site was closer to the anus, the frequency of fragmentation increased; we concluded that pouch reconstruction was an effective surgical technique and colonic nerve preservation was effective in the longer term.

A study of the incidence of implantation cyst at anastomotic sites after low anterior resection of the rectum with the double stapling technique.

BACKGROUND: The incidence of implantation cyst occurring at sites of anastomosis after low anterior resection of the rectum were studied in two different periods depending on the type of surgical devices used to close the rectal stump. SUBJECTS: The study included 361 patients undergoing the surgery during the first 8-year period between 1996 and 2003 and 87 patients undergoing the surgery during the second 3-year period between 2004 and 2006. RESULTS: Implantation cysts were found in nine (2.5%) of the patients undergoing the surgery during the first period and one of them also had local recurrence. Implantation cysts occurred 9 to 31 months postoperatively (mean, 17.1 +/- 6.9 months). Clinical symptoms were noted in one patient and treatment of the cysts, including local recurrence, was given to two patients. Anastomosis of the distal rectum was performed with the Roticulator or the Access 55 in all patients. Although implantation cysts were found in any patient undergoing surgery during the second period, no statistically significant difference was recognized (p = 0.217). Anastomosis of the distal rectum was performed with the TX30 in all patients. CONCLUSION: The pathogenesis of implantation cysts may be explained by the production of mucus when the mucosal epithelium of the colon is caught under the submucosa, forming a cyst after closure of the rectal stump, and the difference in the incidence rates of implantation cyst was presumably due to the characteristics of the device used and progress of the operative procedure.

X-ray diffractometer combining synchrotron radiation and pulsed magnetic fields up to 40 T.

A synchrotron X-ray diffractometer incorporating a pulsed field magnet for high fields up to 40 T has been developed and a detailed description of this instrument is reported. The pulsed field magnet is composed of two coaxial coils with a gap of 3 mm at the mid-plane for passage of the X-rays. The pixel detector PILATUS 100K is used to store the diffracted X-rays. As a test of this instrument, X-ray diffraction by a powder sample of the antiferromagnet CoO is measured below the Néel temperature. A field-dependent lattice distortion of CoO due to magnetostriction is observed up to 38 T.

Thermodynamic properties in the approach to the quantum critical point of the spin-ladder material Na2Co2(C2O4)3(H2O)2.

Magnetic susceptibility and heat capacity measurements as a function of temperature on a single-crystal sample of a spin-ladder material, Na2Co2(C2O4)3(H2O)2, are reported. Principal susceptibilities, parallel and perpendicular to the ladder direction, respectively, show broad maxima around 22 and 17 K. Both susceptibilities decay exponentially down to about 5 K and thereafter they are essentially independent of temperature. These findings amount to a signature of a quantum phase transition from a spin-liquid to Néel ordered state previously predicted theoretically. No anomaly is found in the heat capacity around the transition temperature.

Association of HLA-DM polymorphism with the production of antiphospholipid antibodies.

OBJECTIVE: To investigate whether variation in the HLA-DM gene is important in producing a group of pathogenic autoantibodies-antiphospholipid antibodies (aPL)-on the basis that HLA class II restricted antigen presentation is involved in the production of aPL. METHODS: HLA-DMA and DMB polymorphisms were genotyped by polymerase chain reaction combined with restriction enzyme digestion in 51 white patients with primary antiphospholipid syndrome (APS), 82 with systemic lupus erythematosus (SLE) (42 with APS and 40 without APS), and 109 healthy white controls. The association with the aPL profile was examined. RESULTS: The distribution of DMA alleles in APS patients and in patients with APS associated with SLE was significantly different from that in controls by 4x2 chi(2) test with 3 degrees of freedom (p = 0.035 and 0.011, respectively), but it was not different between SLE patients without APS and controls. The allelic distribution of DMA was also different between patients with IgG class anticardiolipin antibody or those with lupus anticoagulant (LA) and controls (p = 0.012 and 0.007, respectively) and between patients with and without LA among SLE patients (p = 0.035). All these differences included the increase in DMA*0102 in the former groups. CONCLUSIONS: The results suggest that HLA-DMA*0102 or its linked gene(s) form one of the genetic risks for the production of aPL.

Zeeman levels with exotic field dependence in the high field phase of an S=1 Heisenberg antiferromagnetic chain.

We have performed electron spin resonance measurements over a wide frequency and magnetic field range on a single crystal of the S=1 quasi-one-dimensional Heisenberg antiferromagnet Ni(C5H14N2)2N3(PF6). We observed gapped excitation branches above the critical field H(c) where the Haldane gap closes. These branches are analyzed by a phenomenological field theory using the complex-field phi(4) model. A satisfactory agreement between experiment and theory is obtained.

Quasielastic neutron scattering in the high-field phase of a Haldane antiferromagnet.

Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet Ni(C5D14N2)2-N3(PF6) are performed in magnetic fields below and above the critical field H(c) at which the gap closes. Quasielastic neutron scattering is found for H>H(c), indicating topological excitations in the high-field phase.

Field-induced three- and two-dimensional freezing in a quantum spin liquid.

Field-induced commensurate transverse magnetic ordering is observed in the Haldane-gap compound Ni(C(5)D(14)N(2))2N(3)(PF(6)) by means of neutron diffraction. Depending on the direction of applied field, the high-field phase is shown to be either a three-dimensional ordered Néel state or a short-range ordered state with dominant two-dimensional spin correlations. The structure of the high-field phase is determined, and properties of the observed quantum phase transition are discussed.

Plasma tumor necrosis factor alpha levels and the -238*A promoter polymorphism in patients with antiphospholipid syndrome.

OBJECTIVES: To explore the possible involvement of the proinflammatory and prothrombotic cytokine TNFalpha in APS by determining the plasma levels in patients and to test for association of TNFA promoter polymorphisms and HLA class II genotypes with both plasma TNFalpha and disease. PATIENTS AND METHOD: We studied 83 Caucasoid patients with APS and two groups of healthy controls. TNFalpha levels were determined in plasma from 35 patients' and 21 controls using a highly sensitive sandwich ELISA. The full patient group was genotyped together with 95 ethnically matched healthy controls. -308 and -238 TNFA promoter polymorphisms were assessed by ARMS-PCR. HLA-DQB1, DQA1 and DRB1 genotypes were determined by PCR using sequence specific primers. RESULTS: TNFalpha levels were significantly higher in patients with APS than healthy controls (median 2.95 pg/ml [range 0.51-10.75] vs. 0.95 pg/ml [0.51-1.6], respectively; p = 0.0001). Frequencies of TNFA-308*2 genotype did not differ between patients and controls. In contrast, TNFA-238*A positive genotype was more frequent in APS patients with arterial thrombosis and pregnancy loss than in controls (OR 3.7 [95% CI 1.37-10.1], p = 0.007 and OR 3.95 [95% CI 1.3-11.7], p = 0.01; respectively). DQB1*0303-DRB1*0701 haplotype was associated with TNFA-238*A in the control group (OR 96.0 [95% CI 9.6-959], p <0.0001) as well as in APS patient's group (OR 54.2 [95% CI 9.6-306.5], p <0.0001). CONCLUSIONS: Raised plasma TNFalpha levels were found in patients with APS. As a prothrombotic and proinflammatory cytokine, TNFalpha may be involved in the development of clinical features of APS. The lack of correlation between the TNFA-238 polymorphism and plasma levels associated with disease suggests that the TNF genetic marker may only indirectly relate to protein levels by virtue of allelic association with a functional marker which may reside in the HLA class II region.

[Recurrent breast cancer successfully treated with a weekly dose of paclitaxel--a case report].

The patient was a 46-year-old women who was treated for axillary lymph node recurrence of breast cancer by a variety of methods, including surgery, chemotherapy, and radiotherapy, but who experienced recurrences in the cervical and mediastinal lymph nodes and skin, and developed hydrothorax and ascites. Although the recurrent foci responded to 4 cycles of CAF chemotherapy, there was concern that the foci would become refractory or resistant to chemotherapy. The administration of paclitaxel was therefore initiated. The patient received a dose of paclitaxel once a week for 5 consecutive weeks followed by a 1-week recovery period (one cycle). After two cycles of the paclitaxel treatment, a marked shrinkage of the lymph nodes and complete resolution of the hydrothorax and ascites were observed. Even though the patient exhibited bone marrow suppression and G-CSF was administered twice for neutropenia, there were no adverse effects except mild alopecia, again suggesting the possibility that paclitaxel is effective chemotherapy for recurrent breast cancer.

Mössbauer study of the reaction of laser-evaporated iron atoms with nitrogen molecules in low-temperature argon matrices.

Reaction products of laser-evaporated iron atoms with nitrogen molecules were investigated using a low-temperature matrix isolation technique. The products observed in the Mössbauer spectra were FeNNN, Fe(NN), and Fe(NN)2, isolated in argon matrices. Yields of the species changed, depending on the concentration of nitrogen in the matrix. A product assigned to Fe(NN)6 was obtained in a pure nitrogen matrix. Infrared spectra and molecular orbital calculations of the products support these findings.