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1.
Nephrology (Carlton) ; 29(6): 354-362, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38350237

RESUMO

AIM: Patients undergoing haemodialysis have reduced muscle strength and impaired activities of daily living (ADL). We examined possible relationship between difficult ADL and corresponding muscle weakness in elderly haemodialysis patients. METHODS: This was a single-centre, cross-sectional study. Patient-reported ADL difficulty was examined using a questionnaire in six ADL using upper limbs (eating, grooming and dressing) and lower limbs (bathing, toileting and locomotion). We measured six muscle strengths by dynamometers of shoulder flexion, shoulder abduction, elbow flexion, handgrip, hip abduction and knee extension. The muscle strength with the lowest Z-score was considered as the weakest muscle strength for the patient. RESULTS: The six scores of ADL difficulty were all inversely associated with the six muscle strengths in the 81 total participants of whom 71 individuals (87.7%) had any ADL difficulty. Among the six measurements of muscle strength, handgrip strength showed the highest associations with all ADL difficulties. In 25 patients who perceived that the most difficult ADL was an activity using upper limbs, the common weakest muscle strengths were the hip abduction, handgrip and elbow flexion. In 44 patients who perceived that the most difficult ADL was an activity using lower limbs, knee extension was the most prevalent weakest muscle strength. CONCLUSION: This study suggested preferential relationship between the most difficult ADL and corresponding muscle weakness in elderly haemodialysis patients. This finding may be useful in prevention and treatment.


Assuntos
Atividades Cotidianas , Força Muscular , Debilidade Muscular , Diálise Renal , Humanos , Diálise Renal/efeitos adversos , Debilidade Muscular/fisiopatologia , Debilidade Muscular/etiologia , Debilidade Muscular/diagnóstico , Masculino , Feminino , Idoso , Estudos Transversais , Idoso de 80 Anos ou mais , Força da Mão
2.
Nephrol Dial Transplant ; 38(4): 1002-1008, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-35869969

RESUMO

BACKGROUND: Hyperphosphatemia is a risk factor for cardiovascular outcomes in patients with chronic kidney disease. In an experimental model, hyperphosphatemia promoted atherosclerosis by activating sterol regulatory element-binding protein 2, which controls cholesterol homeostasis. In the present study, we hypothesized that serum phosphate level is associated with cholesterol metabolism in patients with kidney failure. METHODS: We conducted a single-center cross-sectional study including 492 patients undergoing hemodialysis and 100 healthy controls not on statin or ezetimibe treatment. Serum lathosterol and campesterol levels were measured as a marker of cholesterol synthesis and absorption, respectively. As compared with the control group, the hemodialysis patients had higher median phosphate {5.8 mg/dL [interquartile range (IQR 5.0-6.6) versus 3.3 (3.0-3.6); P < .001], lower lathosterol [1.2 µg/mL (IQR 0.8-1.7) versus 2.6 (1.9-3.4); P < .001] and higher campesterol levels [4.5 µg/mL (IQR 3.6-6.0) versus 4.1 (3.2-5.4); P = .02]. Serum phosphate correlated positively to campesterol in the control group (Spearman's r = 0.21, P = .03) and in hemodialysis patients (Spearman's r = 0.19, P < .001). The positive association between phosphate and campesterol levels in the hemodialysis group remained significant in multivariable-adjusted linear regression analysis. There was no significant association between phosphate and lathosterol in either group. CONCLUSIONS: An independent association was found between phosphate and campesterol levels in patients with kidney failure. This study suggests a novel relationship between phosphate and cholesterol metabolism, both of which could affect cardiovascular outcomes in this population.


Assuntos
Hiperfosfatemia , Insuficiência Renal , Humanos , Estudos Transversais , Colesterol/metabolismo , Diálise Renal/efeitos adversos , Fosfatos
3.
Inorg Chem ; 62(45): 18474-18484, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37905815

RESUMO

In this study, we successfully synthesized the double perovskite oxide Cd2FeReO6 by using a high-temperature and high-pressure method. The crystal structure was confirmed to belong to the P21/n space group, exhibiting approximately 68% ordering of Fe3+ and Re5+ ions at the perovskite B-site with the remaining regions showing antisite disorder. The measured Curie temperature of Cd2FeReO6 was 460 K, slightly lower than expected but still significantly above room temperature. Remarkably, Cd2FeReO6 displayed a remarkable low-field butterfly type tunneling magnetoresistance of -23% (-37% between the lowest and the largest values) at 5 K and 90 kOe, the highest among the A2FeReO6 (A = Ca, Sr, Pb, Ba) family. First-principles calculations provided insight into the origin of this observed magnetoresistance behavior, revealing Cd2FeReO6's half-metallic ferrimagnetic nature. This research extends our understanding of the double perovskite family and emphasizes its potential significance in the domains of spintronics and materials science. The exploration of differing magnetoresistance behaviors between Cd2FeReO6 and Ca2FeReO6, along with the influence of antisite disorder in Cd2FeReO6, opens intriguing avenues for further research.

4.
Inorg Chem ; 62(26): 10481-10489, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37349281

RESUMO

Band gap engineering using multiple anions is an established approach to novel photocatalysts that exhibit suitable band gap energies for water splitting and high photocorrosion resistance. However, few studies have been conducted on photocatalysts with polyanions, including polychalcogenide ions. Here, we present a new quaternary gallium oxysulfide with disulfide pairs (S2)2-, La4Ga2S8O3, grown out of a KI molten salt. Single-crystal X-ray diffraction analysis revealed that the oxysulfide crystallizes in the orthorhombic space group Pbcn with lattice constants of a = 18.3330(6) Å, b = 13.0590(5) Å, and c = 5.9022(3) Å. In the crystal structure, the GaS4-based zigzag chains and OLa4-based fluorite-like strips are independently arranged in two dimensions, which alternately stack via the disulfide pairs along the third direction. The oxysulfide is a direct-type semiconductor with a band gap of 2.45 eV. First-principles calculations combined with X-ray photoemission spectroscopy measurements show that S 3p states derived from the disulfide pairs dominate the valence band maximum and conduction band minimum, and these band-edge positions are suitable for the oxidation and reduction of water. Our comprehensive study based on the electronic structure suggests that the disulfide pairs make La4Ga2S8O3 a potential photocatalyst for water splitting under visible-light irradiation.

5.
Inorg Chem ; 61(51): 21148-21156, 2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36516859

RESUMO

Under high-pressure and high-temperature conditions, doped Bi3Re3O11 and Bi3Os3O11 with Fe up to 29 atomic % were synthesized. The crystal structures and chemical compositions of Bi3Os2.45Fe0.55O11 and Bi3Re2.13Fe0.87O11 were determined by synchrotron powder X-ray diffraction and electron probe microanalysis. Both crystal structures were explained by a KSbO3-type model with the space group Pn3̅. Magnetic and electronic transport property measurements showed that Bi3Os2.45Fe0.55O11 exhibited a ferrimagnetic transition at the highest magnetic ordering temperature of 490 K in the KSbO3-type, while Bi3Re2.13Fe0.87O11 exhibited a spin glassy behavior below 22 K. The magnetoresistance at 5 K and 90 kOe was almost zero for Bi3Os2.45Fe0.55O11, but -10% for Bi3Re2.13Fe0.87O11. These results suggest that KSbO3- type 5d oxides, which exhibit only weak temperature-dependent paramagnetism to date, are a group of compounds that can be converted into spintronic materials by doping with 3d elements, leading to the development of new KSbO3-type materials with both theoretical and practical significance.

6.
Heart Vessels ; 37(6): 1066-1074, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35059806

RESUMO

The number of patients on maintenance hemodialysis (HD) diagnosed with sarcopenia has been increasing through as individuals age. Recent focus is on the condition termed, "dynapenia," which reduces only muscle function, as opposed to sarcopenia, which reduces both muscle mass and function. However, the association between dynapenia and cardio-cerebrovascular (CV) events in patients undergoing HD is largely unknown. The purpose of this study was to evaluate whether sarcopenia and dynapenia are associated with the onset of CV events in patients undergoing HD. We retrospectively analyzed 342 patients undergoing HD between January and December 2018. Patients who underwent HD thrice per week for > 3 months were included in the analysis. We adopted the Asian Working Group on Sarcopenia criteria for the diagnosis of sarcopenia and dynapenia. In this study, 244 patients undergoing HD were enrolled. The prevalence of sarcopenia was 38.5%. Sarcopenia was determined to be an independent contributor to CV events in patients undergoing HD. To investigate the clinical relevance of dynapenia in patients with HD, patients without sarcopenia were further divided into dynapenia and non-dynapenia groups. Among 150 patients without sarcopenia, 46 were diagnosed with dynapenia. In the Kaplan-Meier analysis, the rate of CV events was significantly different among the three groups in a stratified manner, with the highest rate in the sarcopenia group and the lowest rate in the non-sarco-dynapenia group. Both patients with sarcopenia and dynapenia had significantly increased CV events compared to those with non-sarco-dynapenia (HR 8.00; 95% CI 2.73-34.1; p < 0.0001 vs. HR 4.85; 95% CI 1.28-23.0; p < 0.02). Both sarcopenia and dynapenia resulted in significantly higher CV events than non-sarco-dynapenia in patients undergoing HD. Therefore, clinicians should evaluate muscle function in addition to muscle quantity to estimate CV events in patients undergoing HD.


Assuntos
Sarcopenia , Humanos , Prevalência , Diálise Renal/efeitos adversos , Estudos Retrospectivos , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia
7.
J Ren Nutr ; 32(6): 751-757, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35122993

RESUMO

OBJECTIVE: Infection is related to a higher rate of hospitalization and subsequent death in patients undergoing hemodialysis. Limited data are available about factors associated with death after hospitalization for infection. Nutritional disorder also known as protein energy wasting is profoundly associated with poor consequences. The Geriatric Nutritional Risk Index (GNRI) is a simple but useful nutritional screening tool to predict mortality. We examined whether the GNRI could predict hospitalization for infection and subsequent death. DESIGN AND METHODS: This was a prospective cohort study on patients undergoing hemodialysis. The predictor was the GNRI. The patients were divided into tertiles of the GNRI (T1 to T3), with the highest tertile of T3 as the referent. The outcomes of interest were all-cause mortality, hospitalization for infection, and subsequent death. RESULTS: Of 518 patients, 107 patients died (median follow-up period: 5.0 years; interquartile range: 3.6-5.0) and 169 patients experienced new hospitalization for infection (median follow-up period: 4.5 years; interquartile range: 3.4-5.0) during the follow-up period from December 2004 to December 2009. A lower GNRI was a significant predictor for all-cause mortality in multivariable Cox models (hazard ratio [HR]: 2.9, 95% confidential interval [CI]: 1.5-5.5, P < .001 for T1 vs. T3). However, the GNRI was not associated with hospitalization for infection in multivariable Fine-Gray models with death as a competing risk (subdistributional HR: 1.5, 95% CI: 1.0-2.3, P = .056 for T1 vs. T3). After hospitalization for infection, 38 patients died during the subsequent 2.5-year follow-up period. The GNRI was a significant predictor of death after hospitalization for infection in multivariable Cox models (HR: 2.7, 95% CI: 1.3-5.6, P = .006 for T1 vs. T2+T3). CONCLUSIONS: A lower GNRI predicted a higher risk of all-cause mortality but not hospitalization for infection. However, a lower GNRI was significantly associated with a higher risk of mortality after hospitalization for infection. These findings suggest that long-term mortality after hospitalization for infection was predicted by nutritional disorder evaluated by the GNRI.


Assuntos
Desnutrição , Distúrbios Nutricionais , Humanos , Idoso , Avaliação Nutricional , Estudos Prospectivos , Estado Nutricional , Avaliação Geriátrica , Diálise Renal , Fatores de Risco , Desnutrição/epidemiologia
8.
J Ren Nutr ; 32(1): 94-101, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34465504

RESUMO

OBJECTIVES: This retrospective cohort study investigated the association of diabetes with mortality in hemodialysis patients with regard to obesity, sarcopenia, and sarcopenic obesity, along with examining the prevalence of each group and diabetes. METHODS: Muscle strength, muscle mass, and fat mass were evaluated using a hand dynamometer and dual-energy X-ray absorptiometry, respectively, in 308 chronic hemodialysis patients (age 58.0 ± 11.9 years, hemodialysis duration 6.5 ± 6.0 years, males 60.1%, diabetes 32.8%). Sarcopenia was defined according to the new criteria established by the Asian Working Group on Sarcopenia 2019. Obesity was defined by percent body fat mass (males ≥25%, females ≥35%). RESULTS: The enrolled patients were divided into the normal (38.7%), obesity (18.8%), sarcopenia (26.9%), and sarcopenic obesity (15.6%) groups. The prevalence of diabetes was significantly skewed among the 4 groups (χ2 test, P = .0057), being higher in the sarcopenic obesity group (54.2%) compared to the others (25.9-33.7%). Multivariate regression analysis revealed that diabetes was significantly and independently associated with sarcopenic obesity (odds ratio 3.495, 95% confidence interval 1.683-7.255, P = .0008) after adjustments for several cofounders, but not significantly associated with sarcopenia. During the follow-up period of 76 ± 35 months, 100 patients died. Those in the sarcopenia and sarcopenic obesity groups had significantly higher rates of all-cause mortality compared to patients in the normal and obesity groups (P = .0004, log-rank test). Furthermore, multivariate Cox proportional hazards analysis revealed that presence of diabetes was significantly associated with higher all-cause mortality in all 308 patients, after adjustments for several factors, including the presence of each group in 4 models. CONCLUSION: Sarcopenic obesity is highly prevalent in chronic hemodialysis patients. Diabetes was found to be a significant and independent contributor to the presence of sarcopenic obesity. Diabetes was shown to be a significant predictor of all-cause mortality, independent of the present normal, obesity, sarcopenia, and sarcopenic obesity groups.


Assuntos
Diabetes Mellitus , Sarcopenia , Idoso , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/epidemiologia , Diálise Renal , Estudos Retrospectivos , Sarcopenia/complicações , Sarcopenia/epidemiologia
9.
J Am Soc Nephrol ; 32(3): 723-735, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33547218

RESUMO

BACKGROUND: In patients on maintenance dialysis, cardiovascular mortality risk is remarkably high, which can be partly explained by severe coronary artery calcification (CAC). Hyperphosphatemia has been reported to be associated with the severity of CAC. However, the optimal phosphate range in patients on dialysis remains unknown. This study was planned to compare the effects on CAC progression of two types of noncalcium-based phosphate binders and of two different phosphate target ranges. METHODS: We conducted a randomized, open-label, multicenter, interventional trial with a two by two factorial design. A total of 160 adults on dialysis were enrolled and randomized to the sucroferric oxyhydroxide or lanthanum carbonate group, with the aim of reducing serum phosphate to two target levels (3.5-4.5 mg/dl in the strict group and 5.0-6.0 mg/dl in the standard group). The primary end point was percentage change in CAC scores during the 12-month treatment. RESULTS: The full analysis set included 115 patients. We observed no significant difference in percentage change in CAC scores between the lanthanum carbonate group and the sucroferric oxyhydroxide group. On the other hand, percentage change in CAC scores in the strict group (median of 8.52; interquartile range, -1.0-23.9) was significantly lower than that in the standard group (median of 21.8; interquartile range, 10.0-36.1; P=0.006). This effect was pronounced in older (aged 65-74 years) versus younger (aged 20-64 years) participants (P value for interaction =0.003). We observed a similar finding for the absolute change in CAC scores. CONCLUSIONS: Further study with a larger sample size is needed, but strict phosphate control shows promise for delaying progression of CAC in patients undergoing maintenance hemodialysis. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Evaluate the New Phosphate Iron-Based Binder Sucroferric Oxyhydroxide in Dialysis Patients with the Goal of Advancing the Practice of EBM (EPISODE), jRCTs051180048.


Assuntos
Calcinose/sangue , Calcinose/etiologia , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Fosfatos/sangue , Diálise Renal/efeitos adversos , Adulto , Idoso , Calcinose/prevenção & controle , Doença da Artéria Coronariana/prevenção & controle , Progressão da Doença , Combinação de Medicamentos , Feminino , Compostos Férricos/efeitos adversos , Compostos Férricos/uso terapêutico , Humanos , Hiperfosfatemia/complicações , Hiperfosfatemia/tratamento farmacológico , Hiperfosfatemia/prevenção & controle , Lantânio/efeitos adversos , Lantânio/uso terapêutico , Masculino , Pessoa de Meia-Idade , Diálise Renal/métodos , Sequestrantes/efeitos adversos , Sequestrantes/uso terapêutico , Sacarose/efeitos adversos , Sacarose/uso terapêutico , Adulto Jovem
10.
J Bone Miner Metab ; 39(6): 1082-1090, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34324082

RESUMO

INTRODUCTION: Romosozumab reportedly increases bone mineral density (BMD) potently but might adversely affect cardiovascular disease (CVD). We evaluated the efficacy of romosozumab in osteoporotic HD patients with a high risk of fracture. MATERIALS AND METHODS: This was a single-center 1-year study in Japanese HD patients. Among 96 HD romosozumab-treated HD patients with high risk of fracture, 76 HD patients completed 1 year of subcutaneous administration of romosozumab (210 mg/4 weeks) for 1 year. Romosozumab-untreated HD patients (n = 55) were also included. Changes in BMD and serum markers, together with fracture occurrence, and CVD events, were monitored. RESULTS: During romosozumab treatment of 76 HD patients, BMD time-dependently increased significantly by 15.3% ± 12.9% at the lumbar spine (L1-4), and 7.2% ± 8.3% at the femoral neck at 1 year. Serum BAP and total P1NP increased significantly and serum TRACP-5b decreased at 4 weeks. Fragility fractures occurred in three (3.8%) patients. Hypocalcemia occurred at 4-48 weeks despite the increased dosing of active vitamin-D derivatives, but without any symptom. New CVD events occurred in 5.2% of romosozumab-treated HD patients and10.9% in romosozumab-untreated HD patients. CONCLUSIONS: BMD was increased significantly during romosozumab treatment at the lumbar spine, and the femoral neck, respectively, at 1 year in HD patients. Hypocalcemia occurred but without any intolerable event. There was no apparent increase in CVD events during 1 year of study, suggesting romosozumab as a promising agent for HD patients with severe osteoporosis.


Assuntos
Conservadores da Densidade Óssea , Osteoporose , Anticorpos Monoclonais , Densidade Óssea , Humanos , Japão , Osteoporose/tratamento farmacológico , Diálise Renal
11.
BMC Nephrol ; 22(1): 104, 2021 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-33743638

RESUMO

BACKGROUND: Inhibition of hypoxia-inducible factor prolyl hydroxylase (HIF-PH) is a novel choice for the treatment of renal anemia, and an oral HIF-PH inhibitor roxadustat was approved for renal anemia. Roxadustat has high affinity to thyroid hormone receptor beta, which may affect thyroid hormone homeostasis. CASE PRESENTATION: We present here a patient undergoing hemodialysis with primary hypothyroidism receiving levothyroxine replacement, who showed decreased free thyroxine (FT4) and thyroid stimulating hormone (TSH) after starting roxadustat. Pituitary stimulation test revealed selective suppression of TSH secretion. Recovery of TSH and FT4 levels after stopping roxadustat suggested the suppression of TSH was reversible. CONCLUSIONS: Physicians should pay special attention to thyroid hormone abnormalities in treatment with roxadustat.


Assuntos
Anemia/tratamento farmacológico , Glicina/análogos & derivados , Isoquinolinas/efeitos adversos , Diálise Renal , Tireotropina/efeitos dos fármacos , Tireotropina/metabolismo , Idoso , Anemia/etiologia , Glicina/efeitos adversos , Humanos , Masculino , Insuficiência Renal/complicações , Insuficiência Renal/terapia
12.
Angew Chem Int Ed Engl ; 60(51): 26561-26565, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34626037

RESUMO

Chalcogenide-containing compounds have been widely studied as infrared nonlinear optical (NLO) materials. However, they have never been applied in the ultraviolet (UV) region owing to the high energy levels of chalcogen anions, leading to band gap narrowing. We report the synthesis of a new UV NLO oxysulfide La3 Ga3 Ge2 S3 O10 with an exceptionally wide band gap of 4.70 eV due to from the unique anion-ordered frameworks comprising 1D 1 ∞ [(Ga3/5 Ge2/5 )3 S3 O3 ] triangular tubes and 0D (Ga3/5 Ge2/5 )2 O7 dimers of corner-sharing (Ga/Ge)S2 O2 and (Ga/Ge)O4 tetrahedra, respectively. Second harmonic generation (SHG) measurements revealed that La3 Ga3 Ge2 S3 O10 was phase matchable with twice the SHG response of KH2 PO4 . The results of theoretical calculations suggest that the strong SHG response is mainly attributable to the S-3p and O-2p orbitals in the occupied states. The anion-directed band-gap engineering may give insights into the application of NLO oxychalcogenides in the UV regions.

13.
Inorg Chem ; 59(6): 4049-4057, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32096400

RESUMO

Polycrystalline Sr3OsO6, which is an ordered double-perovskite insulator, is synthesized via solid-state reaction under high-temperature and high-pressure conditions of 1200 °C and 6 GPa. The synthesis enables us to conduct a comparative study of the bulk form of Sr3OsO6 toward revealing the driving mechanism of 1000 K ferromagnetism, which has recently been discovered for epitaxially grown Sr3OsO6 films. Unlike the film, the bulk is dominated by antiferromagnetism rather than ferromagnetism. Therefore, robust ferromagnetic order appears only when Sr3OsO6 is under the influence of interfaces. A specific heat capacity of 39.6(9) × 10-3 J mol-1 K-2 is found at low temperatures (<17 K). This value is remarkably high, suggesting the presence of possible Fermionic-like excitations at the magnetic ground state. Although the bulk and film forms of Sr3OsO6 share the same lattice basis and electrically insulating state, the magnetism is entirely different between them.

14.
Inorg Chem ; 57(15): 8701-8704, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30024158

RESUMO

Hybridization of coordination polymers allows for combining two or more distinct structures into one material. Here, we explore the core/shell-type materials of Prussian blue analogues (PBAs) by heteroepitaxial growth and demonstrate how one phase structurally dominates the other. The volumetric ratio between the shell and core crystals determine the final structure of the hybrids. The outermost dominated the Na+ ion insertion/extraction, illustrating how the hybridization can adjust the function of PBAs.

15.
Inorg Chem ; 57(9): 5615-5623, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29671318

RESUMO

We report the successful synthesis of three new Ruddlesden-Popper-type scandium oxychloride perovskites, Sr2ScO3Cl, Sr3Sc2O5Cl2, and Ba3Sc2O5Cl2, by conventional solid-state reaction. Small single crystals of Sr2ScO3Cl were obtained by a self-flux method, and the crystal structure was determined to belong to the tetragonal P4/ nmm space group ( a = 4.08066(14) Å, c = 14.1115(8) Å) by X-ray diffraction analysis. The scandium center forms a ScO5Cl octahedron with ordered apical oxygen and chlorine anions. The scandium cation, however, is shifted from the position of the octahedral center toward the apical oxygen anion, such that the coordination geometry of the Sc cation can be effectively viewed as an ScO5 pyramid. These structural features in the oxychloride are different from those of octahedral ScO5F coordinated with a partial O/F anion order at the apical sites in the oxyfluoride Sr2ScO3F. Rietveld refinements of the neutron powder diffraction data of Sr3Sc2O5Cl2 ( I4/ mmm: a = 4.107982(5) Å, c = 23.58454(7) Å) and Ba3Sc2O5Cl2 ( I4/ mmm: a = 4.206920(5) Å, c = 24.54386(6) Å) reveal the presence of pseudo ScO5 pyramids with the Cl anion being distant from the scandium cation, which is similar to the Sc-centered coordination geometry in Sr2ScO3Cl with the exception that the ScO5 pyramids form double layers by sharing the apical oxygen. Density functional calculations on Sr2ScO3Cl indicate the strong covalency of the Sc-O bonds but almost nonbonding interaction between Sc and Cl ions.

16.
Inorg Chem ; 57(13): 7601-7609, 2018 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-29906107

RESUMO

The crystal structure of HgPbO3 was studied using single-crystal X-ray diffraction and powder synchrotron X-ray diffraction. The structure was well characterized as a centrosymmetric model with a space group of R-3 m [hexagonal setting: a = 5.74413(6) Å and c = 7.25464(8) Å] rather than as a noncentrosymmetric model as was expected. It was found that Pb4+ is octahedrally coordinated by six oxygen atoms as usual, while Hg2+ is coordinated by three oxygen atoms in a planar manner, this being a very rare coordination of Hg in a solid-state material. The magnetic and electronic transport properties were investigated in terms of the magnetic susceptibility, magnetization, Hall coefficient, and specific heat capacity of polycrystalline HgPbO3. Although HgPbO3 has a carrier concentration (=7.3-8.5 × 1020 cm-3) that is equal to that of metallic oxides, the very weak temperature dependence of the electrical resistivity (residual-resistivity ratio ∼1.5), the significant diamagnetism (= -1.02 × 10-4 emu mol-1 at 300 K) that is in the same order of that of Bi powder and the remarkably small Sommerfeld coefficient [=1.6(1) × 10-3 J mol-1 K-2] implied that it is semimetallic in nature. HgPbO3 does not have a cage structure; nevertheless, at temperatures below approximately 50 K, it clearly exhibits phonon excitation of an anharmonic vibrational mode that is as significant as those of RbOs2O6. The mechanism of the anharmonic mode of the HgPbO3 has yet to be identified, however.

17.
Clin Exp Nephrol ; 22(4): 967-972, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29536389

RESUMO

BACKGROUND: In dialysis patients, mortality risk due to cardiovascular diseases is remarkably high and prognosis is poor; coronary artery calcification is considered one of the major contributing factors. It is known that hyperphosphatemia is associated with coronary artery calcification. Therefore, controlling serum phosphate level and thereby mitigating vascular calcification could improve the poor prognosis of dialysis patients. However, the optimal phosphate level in dialysis patients remains unknown; hence, this study was planned to compare the effects of two types of non-calcium-based phosphate binders, and examine the effect of strict control of phosphate on coronary artery calcification. METHODS: EPISODE is a randomized, open-label, multi-center, interventional trial with a two-by-two factorial design (UMIN ID: UMIN000023648). This trial will enroll hemodialysis patients who have been on dialysis for at least 3 months with a pre-dialysis serum phosphate level of at least 5.0 mg/dL or at least 6.1 mg/dL, respectively, in those taking or not taking a phosphate binder, as measured during the observation period. Registered patients will be randomized to the sucroferric oxyhydroxide or lanthanum carbonate arm and will receive the assigned drug to reduce serum phosphate to two target levels (3.5-4.5 mg/dL in strict arm and 5.0-6.0 mg/dL in standard arm) for 12 months. The primary endpoint will be percent change in coronary artery calcification score, and the secondary endpoints will include change from baseline serum phosphate and calcium levels, change in renal anemia-related factors, etc. The desired sample size has been calculated to be 200 patients.


Assuntos
Doença da Artéria Coronariana/etiologia , Compostos Férricos/uso terapêutico , Hiperfosfatemia/tratamento farmacológico , Diálise Renal , Sacarose/uso terapêutico , Calcinose , Quelantes , Doença da Artéria Coronariana/prevenção & controle , Combinação de Medicamentos , Humanos , Hiperfosfatemia/complicações , Ferro , Fosfatos , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
J Ren Nutr ; 28(1): 54-63, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29089279

RESUMO

OBJECTIVE: Alterations in the balance between serum n-3 and n-6 polyunsaturated fatty acids (PUFAs) is predictive of cardiovascular events among hemodialysis patients, although little is known about the serum ratio of n-6 arachidonic acid (AA) to n-6 dihomo-γ-linoleic acid (DGLA) in renal failure. We hypothesized that AA/DGLA ratio is altered in hemodialysis patients resulting in poor clinical outcomes. METHODS: This was a single center cohort study in an urban area in Japan with cross-sectional analyses. Subjects were 517 hemodialysis patients and 122 control subjects. The main exposure was serum AA/DGLA ratio, and the main outcome measures were all-cause mortality and cardiovascular events during 5 years. RESULTS: The hemodialysis patients showed a higher median (interquartile range) AA/DGLA ratio than the control subjects (6.46 [5.22-7.81] versus 4.56 [3.74-6.34], P < .001). In a Cox proportional hazard model adjusted for age, sex, dialysis duration, diabetic nephropathy, prior cardiovascular disease, and the ratio of serum n-3 polyunsaturated fatty acids (eicosapentaenoic acid plus docosahexaenoic acid) to AA, the higher quartiles of AA/DGLA ratio were associated with higher risk for all-cause mortality with hazard ratios (95% confidence interval) of 1.50 (0.84-2.76) for quartile 2, 2.10 (1.18-3.86) for quartile 3, and 2.02 (1.10-3.78) for quartile 4 compared with quartile 1. AA/DGLA ratio showed a similar association with the risk of cardiovascular events. CONCLUSIONS: AA/DGLA ratio was elevated in patients with end-stage renal disease requiring hemodialysis, and a high AA/DGLA ratio was an independent predictor of poor clinical outcomes in this population.


Assuntos
Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/mortalidade , Ácidos Graxos Ômega-6/sangue , Diálise Renal/mortalidade , Idoso , Ácido Araquidônico/sangue , Doenças Cardiovasculares/etiologia , Colesterol/sangue , Estudos Transversais , Dessaturase de Ácido Graxo Delta-5 , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Ácidos Graxos Dessaturases/sangue , Feminino , Seguimentos , Humanos , Japão/epidemiologia , Falência Renal Crônica/sangue , Falência Renal Crônica/complicações , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Diálise Renal/efeitos adversos , Fatores de Risco , Albumina Sérica/metabolismo , Resultado do Tratamento
19.
Inorg Chem ; 55(5): 2627-33, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26900953

RESUMO

We have successfully synthesized Sr2MnO3F, a new layered perovskite oxyfluoride with a n = 1 Ruddlesden-Popper-type structure using a high-pressure, high-temperature method. Structural refinements against synchrotron X-ray diffraction data collected from manganese oxyfluoride demonstrated that it crystallizes in a tetragonal cell with the space group I4/mmm, in which the Mn cation is located at the octahedral center position. This is in stark contrast to the related oxyhalides that have square-pyramidal coordination such as Sr2MO3X (M = Fe, Co, Ni; X = F, Cl) and Sr2MnO3Cl. There was no evidence of O/F site order, but close inspection of the anion environment centered at the Mn cation on the basis of bond-valence-sum calculation suggested preferential occupation of the apical sites by the F ion with one oxide ion in a random manner. Magnetic susceptibility and heat capacity measurements revealed an antiferromagnetic ordering at 133 K (=TN), which is much higher than that of the chloride analogue with corrugated MnO2 planes (TN = 80 K).

20.
Inorg Chem ; 54(7): 3422-31, 2015 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-25751088

RESUMO

Double-perovskite oxides Ca2MgOsO6 and Sr2MgOsO6 have been synthesized under high-pressure and high-temperature conditions (6 GPa and 1500 °C). Their crystal structures and magnetic properties were studied by a synchrotron X-ray diffraction experiment and by magnetic susceptibility, specific heat, isothermal magnetization, and electrical resistivity measurements. Ca2MgOsO6 and Sr2MgOsO6 crystallized in monoclinic (P21/n) and tetragonal (I4/m) double-perovskite structures, respectively; the degree of order of the Os and Mg arrangement was 96% or higher. Although Ca2MgOsO6 and Sr2MgOsO6 are isoelectric, a magnetic-glass transition was observed for Ca2MgOsO6 at 19 K, while Sr2MgOsO6 showed an antiferromagnetic transition at 110 K. The antiferromagnetic-transition temperature is the highest in the family. A first-principles density functional approach revealed that Ca2MgOsO6 and Sr2MgOsO6 are likely to be antiferromagnetic Mott insulators in which the band gaps open, with Coulomb correlations of ∼1.8-3.0 eV. These compounds offer a better opportunity for the clarification of the basis of 5d magnetic sublattices, with regard to the possible use of perovskite-related oxides in multifunctional devices. The double-perovskite oxides Ca2MgOsO6 and Sr2MgOsO6 are likely to be Mott insulators with a magnetic-glass (MG) transition at ∼19 K and an antiferromagnetic (AFM) transition at ∼110 K, respectively. This AFM transition temperature is the highest among double-perovskite oxides containing single magnetic sublattices. Thus, these compounds offer valuable opportunities for studying the magnetic nature of 5d perovskite-related oxides, with regard to their possible use in multifunctional devices.

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