The Contact Charge Densities of 4s Electrons of Fe Impurity Atom in Some Transition and Noble Metals(Physics)

The internal conversion electrons from M and N shells of the 14.4 keV transition of ^Fe diffused into Cr, Ni, Cu, Pt and Au substrates were measured using a high-resolution β-ray spectrometer. From relative intensities of conversion electrons analyzed using a deconvolution method, we deduced the contact charge density of 4s electrons ρ_(0) of ^Fe impurity atom in these host metals. The 4s contact charge density of ^Fe embedded in these host metals, as well as Fe and Co metals, is found to be nearly equal. This fact indicates that the 3s contact charge density ρ_(0) plays an important role in the variation of the isomer shift of ^Fe in these alloys

Widely tunable laser frequency offset lock with 30 GHz range and 5 THz offset

We demonstrate a simple and versatile method to greatly extend the tuning range of optical frequency shifting devices, such as acousto-optic modulators (AOMs). We use this method to stabilize the frequency of a tunable narrow-band continuous-wave (CW) laser to a transmission maximum of an external Fabry-Perot interferometer (FPI) with a tunable frequency offset. This is achieved through a servo loop which contains an in-loop AOM for simple radiofrequency (RF) tuning of the optical frequency over the full 30 GHz mode-hop-free tuning range of the CW laser. By stabilizing the length of the FPI to a stabilized helium-neon (HeNe) laser (at 5 THz offset from the tunable laser) we simultaneously transfer the similar to 1 MHz absolute frequency stability of the HeNe laser to the entire 30 GHz range of the tunable laser. Thus, our method allows simple, wide-range, fast and reproducible optical frequency tuning and absolute optical frequency measurements through RF electronics, which is here demonstrated by repeatedly recording a 27-GHz-wide molecular iodine spectrum at scan rates up to 500 MHz/s. General technical aspects that determine the performance of the method are discussed in detail. (C) 2013 Optical Society of Americ

Photoproduction of Long-Lived Holes and Electronic Processes in Intrinsic Electric Fields Seen through Photoinduced Absorption and Dichroism in Ca_3Ga_{2-x}Mn_xGe_3O_{12} Garnets

Long-lived photoinduced absorption and dichroism in the Ca_3Ga_{2-x}Mn_xGe_3O_{12} garnets with x < 0.06 were examined versus temperature and pumping intensity. Unusual features of the kinetics of photoinduced phenomena are indicative of the underlying electronic processes. The comparison with the case of Ca_3Mn_2Ge_3O_{12}, explored earlier by the authors, permits one to finally establish the main common mechanisms of photoinduced absorption and dichroism caused by random electric fields of photoproduced charges (hole polarons). The rate of their diffusion and relaxation through recombination is strongly influenced by the same fields, whose large statistical straggling is responsible for a broad continuous set of relaxation components (observed in the relaxation time range from 1 to about 1000 min). For Ca_3Ga_{2-x}Mn_xGe_3O_{12}, the time and temperature dependences of photoinduced absorption and dichroism bear a strong imprint of structure imperfection increasing with x.Comment: 20 pages, 10 figure

FABP7 expression in normal and stab-injured brain cortex and its role in astrocyte proliferation

Reactive gliosis, in which astrocytes as well as other types of glial cells undergo massive proliferation, is a common hallmark of all brain pathologies. Brain-type fatty acid-binding protein (FABP7) is abundantly expressed in neural stem cells and astrocytes of developing brain, suggesting its role in differentiation and/or proliferation of glial cells through regulation of lipid metabolism and/or signaling. However, the role of FABP7 in proliferation of glial cells during reactive gliosis is unknown. In this study, we examined the expression of FABP7 in mouse cortical stab injury model and also the phenotype of FABP7-KO mice in glial cell proliferation. Western blotting showed that FABP7 expression was increased significantly in the injured cortex compared with the contralateral side. By immunohistochemistry, FABP7 was localized to GFAP+ astrocytes (21% of FABP7+ cells) and NG2+ oligodendrocyte progenitor cells (62%) in the normal cortex. In the injured cortex there was no change in the population of FABP7+/NG2+ cells, while there was a significant increase in FABP7+/GFAP+ cells. In the stab-injured cortex of FABP7-KO mice there was decrease in the total number of reactive astrocytes and in the number of BrdU+ astrocytes compared with wild-type mice. Primary cultured astrocytes from FABP7-KO mice also showed a significant decrease in proliferation and omega-3 fatty acid incorporation compared with wild-type astrocytes. Overall, these data suggest that FABP7 is involved in the proliferation of astrocytes by controlling cellular fatty acid homeostasis

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 &gt;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

PHOTO-INDUCED EFFECT ON PERMEABILITY IN COBALT DOPED Li- AND Mg-FERRITES

Des échantillons polycristallins de Li0,5Fe2,5O4 et de MgFe2O4 dopés au cobalt (0.001 à 0.006 atomes par formule unité) présentent une diminution photo-induite de la perméabilité initiale à 77 K. Pour des teneurs en cobalt plus élevées, une augmentation ou bien un maximum de l'accroissement de la perméabilité sont observés pendant les illuminations successives. Ces observations peuvent être qualitativement interprétées à partir des modifications photo-induites de la concentration en Co2+.Polycrystalline samples of both Li0.5Fe2.5O4 and MgFe2O4 : Co (0.001-0.006 atoms per formula unit) are found to exhibit a photo-induced decrease in initial permeability at 77 K. With higher Co (0.008-0.08) contents, an increase or a maximum of increased permeability during successive flashes is observed. The observations can be qualitatively interpreted in terms of photo-induced change in [Co2+] concentration

ELECTRON SPECTROMETER FOR MÖSSBAUER SPECTROSCOPY

On a construit un nouveau spectromètre d'électrons à champ retardé pour détecter les électrons de conversion interne émis par effet Mössbauer. Ce spectromètre est intéressant pour étudier les propriétés de surface des solides. Le domaine d'énergie observable est compris entre 0 et 20 keV, avec une résolution de 0,1 % pour une transmission de 1 % des électrons émis par un filament chauffé. Cette résolution est plus mauvaise, par un ordre de grandeur, pour les électrons de conversion issus d'une source radioactive. Le système complet qui est décrit comporte le spectromètre d'électrons un évaporateur et un spectromètre Mössbauer.A new retarding-field electron spectrometer has been constructed to detect internal conversion electrons emited in the Mössbauer effect. This spectrometer is useful to investigate the surface properties of solids. The energy range of the spectrometer is from 0 to 20 keV. The transmission of 1 % at 0.1 % resolution was obtained for electrons emitted from a hot filament, but for conversion electrons from a radioactive source the transmission was so far found to be one order worse. The whole system, which is the combination of the electron spectrometer with a vacuum evaporator and a Mössbauer spectrometer, is also described