Mesoscopic Architectures Made of Electrically Charged Binary Colloidal Nanosheets in Aqueous System

Inorganic layered materials can be converted to colloidal liquid crystals through exfoliation into inorganic nanosheets, and binary nanosheet colloids exhibit rich phase behavior characterized by multiphase coexistence. In particular, niobate–clay binary nanosheet colloids are characterized by phase separation at a mesoscopic (∼several tens of micrometers) scale whereas they are apparently homogeneous at a macroscopic scale. Although the mesoscopic structure of the niobate–clay binary colloid is advantageous to realize unusual photochemical functions, the structure itself has not been clearly demonstrated in real space. The present study investigated the structure of niobate–clay binary nanosheet colloids in detail. Four clay nanosheets (hectorite, saponite, fluorohectorite, and tetrasilisic mica) with different lateral sizes were compared. Small-angle X-ray scattering (SAXS) indicated lamellar ordering of niobate nanosheets in the binary colloid. The basal spacing of the lamellar phase was reduced by increasing the concentration of clay nanosheets, indicating the compression of the liquid crystalline niobate phase by the isotropic clay phase. Scattering and fluorescence microscope observations using confocal laser scanning microscopy (CLSM) demonstrated the phase separation of niobate and clay nanosheets in real space. Niobate nanosheets assembled into domains of several tens of micrometers whereas clay nanosheets were located in voids between the niobate domains. The results clearly confirmed the spatial separation of two nanosheets and the phase separation at a mesoscopic scale. Distribution of clay nanosheets is dependent on the employed clay nanosheets; the nanosheets with large lateral length are more localized or assembled. This is in harmony with larger basal spacings of niobate lamellar phase for large clay particles. Although three-dimensional compression of the niobate phase by the coexisting clay phase was observed at low clay concentrations, the basal spacing of niobate phase was almost constant irrespective of niobate concentrations at high clay concentrations, which was ascribed to competition of compression by clay phase and restoring of the niobate phase

糖尿病患者における足部関節可動域と動脈硬化指標の関係

Foot ulcers cause gait disturbances, decreased quality of life, and high rates of mortality in diabetic patients. High plantar pressure and failure of peripheral circulation dynamics have been mentioned as risk factors for diabetic foot ulcers. It has been reported that plantar pressure is affected by the limited joint mobility （LJM） of foot joints. Therefore, preventing LJM of foot joints is important for prevention of diabetic foot ulcers. Failure of peripheral circulation dynamics can be evaluated by measuring brachial-ankle pulse wave velocity （baPWV）. The LJM of foot joints and arteriosclerosis are involved in the etiology of diabetic foot ulcers, but there have been no studies regarding the relationship between these two factors. We investigated the relationship between the range of motion （ROM） of foot joints and baPWV in diabetic patients.The study population consisted of 48 diabetic patients admitted to hospital for glycemic control and diabetes education. The LJM parameters measured were passive ROM of plantar flexion and dorsiflexion of the ankle joint, flexion and extension of the first metatarsophalangeal joint, and pronation and supination of the subtalar joint. baPWV was measured using an automated device. Pearsonʼs and partial correlation coefficients of patientsʼ baPWV and ROM values were calculated. The control conditions were age, gender, diabetes condition （diabetes duration, HbA1c levels, and diabetic polyneuropathy）, and arteriosclerosis status （systolic and diastolic blood pressure）.The mean age of the subjects was 57.4±11.8 years. ROM values for ankle, first metatarsophalangeal, and subtalar joints were 56.9°±8.8°, 89.7°±11.8°, and 27.0°±7.1°, respectively. Partial correlation analysis revealed a negative correlation between baPWV and ankle ROM （r=－0.35, p=0.03） after controlling for age, sex, systolic and diastolic blood pressure, diabetes duration, HbA1c level, and diabetic polyneuropathy. No significant associations of these outcomes were found in other joints.In diabetic patients, baPWV and ankle ROM were significantly negatively correlated when controlling for factors such as age, systolic and diastolic blood pressure, diabetes duration, HbA1c level, and diabetic polyneuropathy. However, additional studies are needed to draw clinical conclusions.糖尿病性足部潰瘍は歩行障害、QOL の低下、死亡率の上昇を引き起こす。糖尿病性足部潰瘍の危険因子として高すぎる足底圧と末梢循環動態の障害が報告されている。足底圧は、足部関節の可動域制限の影響を受けることが示されている。従って、足部関節の関節可動域制限を予防することは、糖尿病性足部潰瘍の予防において重要である。末梢循環動態は、上腕 ‐ 足首脈波速度（baPWV）で評価できる。足部関節の可動域制限および動脈硬化は糖尿病性足部潰瘍に個々に関与しているが、両者の関係は不明である。そこで本研究の目的は、糖尿病患者の足部関節の関節可動域と baPWV の関係を調べることとした。対象は、血糖コントロールと糖尿病教育のために入院した 48 人の糖尿病患者とした。測定された関節可動域は、足関節の背屈および底屈、第1中足趾節間関節の屈曲および伸展、および距骨下関節の回内および回外方向の他動関節可動域とした。baPWV は専用の自動計測装置で測定した。対象の baPWV および各関節の関節可動域のピアソンおよび偏相関係数を計算した。偏相関係数の統制条件は、年齢、性別、糖尿病の状態（糖尿病罹病期間、 HbA1c 値および糖尿病性多発性神経障害）および動脈硬化に関連する値（収縮期血圧および拡張期血圧）とした。対象の平均年齢は 57.4 ± 11.8 歳であった。足関節、第 1 中足趾節間関節、距骨下関節の関節可動域は、それぞれ 56.9 ± 8.8°、89.7 ± 11.8°、27.0 ± 7.1°であった。偏相関分析は、年齢、性別、収縮期血圧および拡張期血圧、糖尿病期間、HbA1c 値および糖尿病性多発性神経障害の有無で制御した後、baPWV と足関節の関節可動域との間に負の相関を示した（r = -0.35、p = 0.03）。他の関節では有意な関連は認められなかった。糖尿病患者では、年齢、収縮期および拡張期血圧、糖尿病期間、HbA1c 値および糖尿病性多発性神経障害の因子で統制しても、baPWV および足関節の関節可動域は有意に負の相関関係を認めた。しかしながら、臨床的結論を引き出すためにはさらなる研究が必要である