Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Anti-A and anti-B titers, age, gender, biochemical parameters, and body mass index in Japanese blood donors

It has been reported that anti-A and anti-B (ABO antibody) titers decrease with age, but little is known about the association between ABO antibody titers and physiologic/biochemical parameters such as body mass index (BMI), gamma-glutamyl transpeptidase (GGT), and total cholesterol (T-Cho). We investigated the present situation of ABO antibody titers among healthy blood donors in Japan and the physiologic/biochemical factors that may be associated with changes in ABO antibody titers. Plasma from 7450 Japanese blood donors was tested for ABO antibody titers using ABO reverse typing reagents by an automated microplate system; donor samples were classified into low, middle, and high titers according to the agglutination results obtained with diluted plasma samples. Multivariate regression analysis was performed to analyze the association between ABO antibody titers and age, gender, biochemical parameters (alanine transaminase [ALT], GGT, globulin, T-Cho, and glycosylated albumin [GA]), and BMI according to the ABO blood groups. A significant correlation between ABO antibody titers and age/gender, except for gender in anti-A of blood group B donors, was observed. BMI showed significant but negative correlations with anti-A and anti-B (β = -0.085 and -0.062, respectively; p < 0.01) in blood group O donors. In addition, significant but negative correlations between GGT and T-Cho with anti-B of blood group A donors (β = -0.055 and -0.047, respectively; p < 0.05) were observed. Although differences existed among the ABO blood groups, ABO antibody titers seem to be associated with physiologic and biochemical parameters of healthy individuals.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with prostate cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of prostate cancer was published in 2020. It was therefore decided, by both the ESMO and the Singapore Society of Oncology (SSO), to convene a special, virtual guidelines meeting in November 2021 to adapt the ESMO 2020 guidelines to take into account the differences associated with the treatment of prostate cancer in Asia. These guidelines represent the consensus opinions reached by experts in the treatment of patients with prostate cancer representing the oncological societies of China (CSCO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter were discussed when appropriate. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with prostate cancer across the different regions of Asia.

POS0734 THE CLINICAL JUDGMENT FOR THE ACCEPTABILITY OF PREGNANCY IN PATIENTS WITH SEROLOGICALLY ACTIVE SLE IN JAPAN: A NATIONWIDE ONLINE SURVEY FROM THE VIGNETTE STUDY

Background

The risk of pregnancy complications, such as gestational hypertension is high in pregnancies with SLE. In addition, the risk of flare is elevated if pregnancy occurs during the high disease activity. The EULAR recommendation provides a checklist for preconception counseling, in which patients with SLE desiring pregnancy were required the condition that the disease activity prior to pregnancy should be stable for 6-12 months in terms of serological activity (1). However, it does not provide specific criteria for serological activity so that physicians should evaluate the risk of pregnancy in each case by their clinical intuitions.

Objectives

In order to uncover the present clinical situation for the acceptability of pregnancy in patients with SLE, we performed questionnaire survey to physicians regarding to the degree of serological activity.

Methods

This cross-sectional study was performed to physicians registered with the Japanese College of Rheumatology from December 2020 to January 2021 using the online survey. The questionnaire asked about the characteristics of physicians, facilities and the permission of pregnancies with SLE using vignette scenarios. In this study, data from vignettes of women visiting a regular outpatient clinic were used. The vignettes varied in age (28 or 35 years), duration of stable disease and serological activity. Analysis methods were descriptive statistics, chi-square test. generalized estimating equations (GEE) was performed to investigate the relationship between the determining permission for pregnancy and the scenario patient’s characteristics (age, period of stable disease, titer of anti ds-DNA antibody)

Results

The questionnaire was distributed to 4946 physicians, and 463 responded. Completion rate (ratio agreed to participate/finished survey) of survey was 91.1%. The median age of physicians was 46 (interquartile range (IQR) 2-10). The specialty was rheumatology (84.9%), other internal medicine (8%), and pediatrics (5.6%). There were no significant differences in patient’s age about the acceptability of pregnancy (coeffficianet -0.02, 95% CI -0.17 -0.01, p=0.42). Case who had been stable for 6 months were more tolerant of pregnancy than case who had been stable for 3 months (coeffficianet 0.12, 95% CI 0.09-0.15, P<0.001) Pregnancy was not allowed in case with mild or high serological activity (mild: coefficient -0.49, 95% CI -0.29- -0.22, p <0.001, high: -0.64, 95% CI -0.65 - -0.61, p <0.001). In contrast, as many as 92 (19.2%) physicians tolerated pregnancy even in the presence of residual high anti ds-DNA antibody titers. Female physicians are significantly more cautious about pregnancy than male when patients have a serologically high activity (12% vs 37.5%, p<0.001). There were no significant differences in specialty status or clinical experience.

Conclusion

We found that even mild serological activity alone had a significant negative effect on the physician’s decision to allow pregnancy. We conclude that current physicians make cautious decisions about pregnancies of patients with SLE following the recommendation. On the other hand, an additional investigation should be performed about the results of pregnancies in patients with serological abnormalities, since there are some physicians who thought that pregnancy may be acceptable for patients with only serological abnormalities if the clinical symptoms are stable.

References

[1]Ann Rheum Dis．2017 Mar;76(3):476-485

Acknowledgements

I would like to express my gratitude to the members of Japan College of Rheumatology who cooperated in filling out the questionnaire.

Disclosure of Interests

Sakiko Isojima: None declared, Nobuyuki Yajima: None declared, Ryo Yanai: None declared, Yoko Miura: None declared, Shingo Fukuma: None declared, Kayoko Kaneko: None declared, Keishi Fujio: None declared, Kenji Oku: None declared, Masakazu Matsushita: None declared, Takako Miyamae: None declared, Takashi Wada: None declared, Yuko Kaneko: None declared, Yoshiya Tanaka Speakers bureau: Y. Tanaka has received speaking fees and/or honoraria from Gilead, Abbvie, Behringer-Ingelheim, Eli Lilly, Mitsubishi-Tanabe, Chugai, Amgen, YL Biologics, Eisai, Astellas, Bristol-Myers, Astra-Zeneca, Grant/research support from: Y. Tanaka has received research grants from Asahi-Kasei, Abbvie, Chugai, Mitsubishi-Tanabe, Eisai, Takeda, Corrona, Daiichi-Sankyo, Kowa, Behringer-Ingelheim, and consultant fee from Eli Lilly, Daiichi-Sankyo, Taisho, Ayumi, Sanofi, GSK, Abbvie., Ayako Nakajima: None declared, ATSUKO MURASHIMA: None declared

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with renal cell carcinoma

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of renal cell carcinoma was published in 2019 with an update planned for 2021. It was therefore decided by both the ESMO and the Singapore Society of Oncology (SSO) to convene a special, virtual guidelines meeting in May 2021 to adapt the ESMO 2019 guidelines to take into account the ethnic differences associated with the treatment of renal cell carcinomas in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with renal cell carcinoma representing the oncological societies of China (CSCO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter were discussed when appropriate.

Open-label phase II study of the efficacy of nivolumab for cancer of unknown primary

BACKGROUND

Cancer of unknown primary (CUP) has a poor prognosis. Given the recent approval of immune checkpoint inhibitors for several cancer types, we carried out a multicenter phase II study to assess the efficacy of nivolumab for patients with CUP.

PATIENTS AND METHODS

Patients with CUP who were previously treated with at least one line of systemic chemotherapy constituted the principal study population. Previously untreated patients with CUP were also enrolled for exploratory analysis. Nivolumab (240 mg/body) was administered every 2 weeks for up to 52 cycles. The primary endpoint was objective response rate in previously treated patients as determined by blinded independent central review according to RECIST version 1.1.

RESULTS

Fifty-six patients with CUP were enrolled in the trial. For the 45 previously treated patients, objective response rate was 22.2% [95% confidence interval (CI), 11.2% to 37.1%], with a median progression-free survival and overall survival of 4.0 months (95% CI, 1.9-5.8 months) and 15.9 months (95% CI, 8.4-21.5 months), respectively. Similar clinical benefits were also observed in the 11 previously untreated patients. Better clinical efficacy of nivolumab was apparent for tumors with a higher programmed death-ligand 1 expression level, for those with a higher tumor mutation burden, and for microsatellite instability-high tumors. In contrast, no differences in efficacy were apparent between tumor subgroups based on estimated tissue of origin. Adverse events were consistent with the known safety profile of nivolumab. No treatment-related death was observed.

CONCLUSIONS

Our results demonstrate a clinical benefit of nivolumab for patients with CUP, suggesting that nivolumab is a potential additional therapeutic option for CUP.

Transmission of extended-spectrum β-lactamase-producing Klebsiella pneumoniae associated with sinks in a surgical hospital ward, confirmed by single-nucleotide polymorphism analysis

BACKGROUND

Although sink- and drain-related carbapenemase-producing Enterobacterales transmission has been reported previously, there is limited research regarding the transmission of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales.

AIM

To investigate nosocomial ESBL-producing Klebsiella pneumoniae transmission via patient sinks and drains on a general surgical hospital ward.

METHODS

ESBL-producing K. pneumoniae transmission on a surgical ward at Tokyo Medical University Hospital (built in July 2019) from July 2019 to February 2020 was investigated. Information regarding the relatedness of the isolates from the patients and the environment was provided by whole-genome sequence analysis.

FINDINGS

Four clinical isolates of K. pneumoniae (TUM19831, TUM19832, TUM19833 and TUM19834) were detected during the study. TUM19831 was identified prior to moving to the new building and was detected again in the new building. TUM19832 and TUM19833 were detected in July 2019, and TUM19834 was detected in December 2019. TUM19835 and TUM19836 were detected in two different sinks and drains in July 2019, while a further two sinks and drains tested positive for TUM19837 and TUM19838 in February 2020. Whole-genome analysis revealed that all strains were ST307 and CTXM15 sequence types, and the isolates were indistinguishable by genetic analysis. Due to inadequate removal of the slime biofilm coating, the sinks needed to be cleaned again before TUM19837 and TUM19838 could be detected.

CONCLUSIONS

This study demonstrated the transmission of indistinguishable ESBL-producing K. pneumoniae strains from sinks and drains in the patient area of a general surgical hospital ward. There is a need to recognize this risk and develop optimal management strategies for plumbing systems in hospitals and other healthcare settings.

Observation of Nonlinear Spin-Charge Conversion in the Thin Film of Nominally Centrosymmetric Dirac Semimetal SrIrO_{3} at Room Temperature

Spin-charge conversion via spin-orbit interaction is one of the core concepts in the current spintronics research. The efficiency of the interconversion between charge and spin current is estimated based on Berry curvature of Bloch wave function in the linear-response regime. Beyond the linear regime, nonlinear spin-charge conversion in the higher-order electric field terms has recently been demonstrated in noncentrosymmetric materials with nontrivial spin texture in the momentum space. Here, we report the observation of the nonlinear charge-spin conversion in a nominally centrosymmetric oxide material SrIrO_{3} by breaking inversion symmetry at the interface. A large second-order magnetoelectric coefficient is observed at room temperature because of the antisymmetric spin-orbit interaction at the interface of Dirac semimetallic bands, which is subject to the symmetry constraint of the substrates. Our study suggests that nonlinear spin-charge conversion can be induced in many materials with strong spin-orbit interaction at the interface by breaking the local inversion symmetry to give rise to spin splitting in otherwise spin degenerate systems.

Feasibility and safety of non-contrast percutaneous coronary intervention in patients with complicated acute coronary syndrome

Background

Contrast-induced acute kidney injury (CI-AKI) occurs in 10% to 20% of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), resulting in a poor short- and long-term prognosis. Reducing the amount of contrast medium can prevent CI-AKI.

Objectives

This study aimed to examine the feasibility and safety of non-contrast PCI in patients with ACS.

Methods

The study was a prospective and single-center registry. Successful non-contrast PCI was confirmed when contrast medium was not injected from the guiding catheter engagement to wire removal in ad-hoc PCI. Coronary angiography after the PCI procedure was permitted once. CI-AKI was defined as an increase in the serum creatinine of ≥0.5 mg/dL from or ≥1.25 times the baseline within 72 hours after PCI. Worsening renal function (WRF) was defined as an increase in the serum creatinine of ≥0.3 mg/dL from baseline after the PCI.

Results

The present study included 106 lesions from 81 patients. Forty-eight lesions were (45%) type C lesions. Successful non-contrast PCI was performed in 95 lesions (90%). CI-AKI was observed in 4 (5%); coronary perforation, 0; no/slow flow, 9 (11%); periprocedural death, 0. The follow-up period was 348 (190–492) days. Successful non-contrast PCI was not associated with the incidence of CI-AKI. However, WRF at 6-month was observed in 18 individuals (22%). Successful non-contrast PCI was inversely associated with WRF (hazard ratio, 0.28; 95% confidence interval, 0.09–0.90) after adjustment for renal function.

Conclusions

The present study suggests that non-contrast PCI is feasible and safe in ACS patients with complex lesions.

Funding Acknowledgement

Type of funding source: None

AB0090 DEATH RECEPTOR 3 REGULATES THE GENE EXPRESSIONS OF VARIOUS KEY MOLECULES IN RHEUMATOID SYNOVIAL FIBROBLASTS

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes hyperplasia of synovial tissue. Death receptor 3 (DR3) is a tumor necrosis factor receptor and binds to TL1A, a member of the TNF family. DR3 is involved in the mechanism of cell proliferation and apoptosis through NF-κB signaling. Suppression of DR3 in rheumatoid synovial fibroblasts (RA-FLS) is associated with hyperplasia of rheumatoid synovial tissue [1]. We previously revealed the expression profiles regulated by TL1A, suggesting that TL1A might affect the pathogenesis of RA, including proliferation, regulation of B cells and T cells, inflammation, and cytokine processing [2].

Objectives:

In this study, we investigated the gene expression profiles regulated by DR3 in RA-FLS to reveal how DR3 is involved in the pathogenesis of RA.

Methods:

RA-FLS were from patients with RA. Four individual lines of primary cultured RA-FLS were incubated either with 1000 ng/ml of human DR3-Fc protein or 1000ng/ml of human IgG1 as a control for 12h. Gene expressions were detected by microarray assay.

Results:

Microarray data analysis revealed that DR3 up-regulated or down-regulated the expression of various genes in RA-FLS (Figure). The function of regulated genes included protein-L-isoaspartate (D-aspartate) O-methyltransferase activity, carboxyl-O-methyltransferase activity, protein carboxyl O-methyltransferase activity, regulation of cilium assembly, O-methyltransferase activity, regulation of plasma membrane bounded cell projection assembly, regulation of cell projection assembly, regulation of organelle assembly, protein methyltransferase activity, and S-adenosylmethionine-dependent methyltransferase activity. The most up-regulated 2 genes by DR3 were KIAA1109 (KIAA1109), and adhesion G protein-coupled receptor A3 (ADGRA3). The most down-regulated 2 genes by DR3 were RNA exonuclease 2 (REXO2), and family with sequence similarity 120A (FAM120A).

Conclusion:

In this study, we first revealed the expression profiles of genes regulated by DR3 in RA-FLS. KIAA1109/TENR/IL2/IL21 gene is strongly associated with RA in European descent populations [3]. ADGRA3 is a member of G protein-coupled receptors (GPCRs). GPCRs associates with the regulation of cytoskeletal organization, the cell adhesion and migration, cell proliferation and apoptosis, and cell differentiation [4]. Loss of REXO2 affects cell growth and morphology [5], and REXO2 was identified as a target gene for inflammatory bowel disease-associated variants [6]. FAM120A regulates activity of Src kinase to protect cells from oxidative stress-induced apoptosis [7]. DR3 regulates the gene expressions of various key molecules in RA-FLS and may affect the pathogenesis of RA by regulating gene expression of RA-FLS.

References:

[1]Takami N. et al., Arthritis Rheuma. 2006;54:779-787.

[2]Fukuda K. et al., Biomed Rep. 2019;1:1-5.

[3]Teixeira VH. et al., Arthritis Research & Therapy. 2009;11:R45.

[4]Hamann J. et al., Pharmacol Rev. 2015;67:338-367.

[5]Bruni F, et al., PLoS One. 2013;8:e64670.

[6]Hulur I, et al., BMC Genomics. 2015;16:138.

[7]Tanaka M. et al., Mol Cell Biol. 2009;29:402-413.

Disclosure of Interests:

None declared

Quantification of Turbulent Driving Forces for the Geodesic Acoustic Mode in the JFT-2M Tokamak

We investigate spatial structures of turbulence and turbulent transport modulated by the geodesic acoustic mode (GAM), from which the excitation mechanism of the GAM is discussed. The GAM is found to be predominantly excited through a localized Reynolds stress force, rather than the dynamic shearing force. The evaluated growth rate is larger than the linear damping coefficients and is on the same order of magnitude as the effective growth rate evaluated from time evolution in the GAM kinetic energy.

Controlling the lectin recognition of glycopolymersviadistance arrangement of sugar blocks

Control of molecular recognitionvialiving radical polymerization.

Turbulent transport reduction induced by transition on radial electric field shear and curvature through amplitude and cross-phase in torus plasma

Spatiotemporal evolutions of radial electric field and turbulence are measured simultaneously in the H-mode transition, which is a prototypical example of turbulence structure formation in high-temperature plasmas. In the dynamical phase where transport barrier is established abruptly, the time-space-frequency-resolved turbulent particle flux is obtained. Here we report the validation of the mechanism of transport barrier formation quantitatively. It is found that the particle flux is suppressed predominantly by reducing density fluctuation amplitude and cross phase between density fluctuation and potential fluctuation. Both radial electric field shear and curvature are responsible for the amplitude suppression as was predicted by theory. Turbulence amplitude reduction immediately responds to the growth of the radial electric field non-uniformity and saturates, while cross phase continuously approaches zero.

Culturing Periosteum in Vitro: The Influence of Different Sizes of Explants

Periosteal transplantation is being used clinically to repair articular defects. Isolated cells and very small periosteal explants can be grown in tissue culture, but it will be necessary to test larger sizes for tissue engineering to be applied to clinical transplantation of periosteum. This study was conducted to assess the chondrogenic potential of different sizes of periosteal explants in agarose culture. Ninety-six rabbit tibial periosteal explants in three different sizes (small 1.5 × 2, medium 3 × 2, and large 4 × 6 mm, 32 pieces per size) were cultured in agarose suspension for 6 wk and given TGF-β1 (10 ng/mL) for the first 2 wk. Tissue growth, as indicated by normalized final wet weights of the explants after 6 wk in culture, was inversely proportional to explant size. Cartilage formation was observed in all explante. Histomorphometry revealed that cartilage formation was significantly better for the smaller explants (80% cartilage), but similar in the medium and larger explants (60% cartilage). Similar proportions of type II collagen were present in the different-sized explants. This study demonstrates that various sizes of periosteal explants can be grown in culture. Abundant cartilage was produced even by the large explants. © 1998 Elsevier Science Inc.

Crystallographic and electronic properties of AlCrN films that absorb visible light

We investigate the crystallographic and electronic properties of wurtzite Cr-doped AlN (AlCrN) films (Cr ≤12.0%) that absorb visible light. We confirmed that the films consist of wurtzite columnar single crystals that are densely packed, c-axis oriented, and exhibit a random rotation along the a-axis in plane by using transmission electron microscopy. The oxidation state of Cr was found to be 3+ using Cr K-edge X-ray absorption near edge structure, which implies that Cr can be a substitute for Al3+ in AlN. The first nearest neighbor distances estimated using Cr K-edge extended X-ray absorption fine structure (EXAFS) were found to be nearly isotropic for incident light with electric fields that are parallel and perpendicular to the plane. The results of ab initio lattice relaxation calculations for the model of wurtzite Al1-xCrxN supercell where Cr replaces Al support the EXAFS results. The calculations for the model showed that additional energy bands are formed in the band gap of AlN, in which the Fermi energy (EF ) is present. As expected from the calculation results, the electrical conductivity increases with increase in the Cr concentration, implying that the density of states at EF increases monotonically. From these results, we can conclude that AlCrN films are an intermediate band material with respect to their crystallographic and electric properties.