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We fabricated and characterized a single-crystal silicon phonon waveguide structure with lead zirconate titanate (PZT) piezoelectric transducers. The compressive stress in a silicon-on-insulator wafer causes a membrane waveguide to buckle, leading to the quadratic nonlinearity. The PZT transducer integrated in an on-chip configuration enables us to excite high-intensity mechanical vibration, which allows the characterization of nonlinear behavior. We observed a softening nonlinear response as a function of the drive power and demonstrated the mode shift and frequency conversion. This is the first report of the nonlinear behavior caused by the quadratic nonlinearity in a buckled phonon waveguide structure. This study provides a method to control the sign and the order of nonlinearity in a phonon waveguide by utilizing the internal stress, which allows the precise manipulation of elastic waves in phononic integrated circuits.

We have investigated a newly found α′′-phase bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) molecular arrangement system, namely, α′′-(BEDT-TTF)2Rb2xCo(SCN)4 (α′′-Rb2xCo), with localized S = 3/2 ...

Nonlinearity is the key to control a traveling wave beyond linear regime. In contrast to a field of optics where highly functional devices have been developed utilizing the optical nonlinearity, making use of nonlinear effect in a field of acoustic devices has yet to be fully performed. This is due to the lack of a suitable platform realizing a low-loss waveguide as well as an efficient electro-acoustic transduction enough to excite and propagate an intense nonlinear acoustic wave. In this study, we have demonstrated that most fundamental nonlinear phenomena of self-phase modulation and four-wave mixing are fully realized using a developed platform of nanoelectrome-chanical waveguides. Combining the leading-edge technology of high-crystalline-quality nanoelectromechanical waveguide with piezoelectric interdigital transducer, we efficiently excite an intense and long-lived traveling wave enough to induce and characterize acoustic nonlinearity. The observed nonlinear phenomena are perfectly described by the model using the nonlinear Schrodinger equation, so that this system enables the nonlinear dynamics to be precisely tuned. The design flexibility and integratability of this platform extend the ability to manipulate acoustic wave propagation on a chip, thus holding promise for promoting highly-functional acoustic devices and investigating nonlinear acoustics.

The ability to manipulate acoustic and elastic waveforms in continuous media has attracted significant research interest and is crucial for practical applications ranging from biological imaging to material characterization. Although several spatial focusing techniques have been developed, these systems require sophisticated resonant structures with narrow bandwidth, which limit their practical applications. Here we demonstrate temporal pulse manipulation in a dispersive one-dimensional phononic crystal waveguide, which enables the temporal control of ultrasonic wave propagation. On-chip pulse focusing is realized at a desired time and position with chirped input pulses that agree perfectly with the theoretical prediction. Moreover, traveling four-wave mixing experiments are implemented, providing a platform on which to realize novel nonlinear phenomena in the system. Incorporating this dispersive pulse engineering scheme into nonlinear phononic crystal architecture opens up the possibility of investigating novel phenomena such as phononic solitons., Here the authors demonstrate the temporal control of ultrasonic wave propagation in a one-dimensional phononic crystal waveguide. Four-wave mixing experiments are implemented, providing a platform on which to realize novel nonlinear phenomena in the system.

Background. We investigated peritoneal protein selectivity to evaluate whether it may indicate changes in peritoneal pores and be related to the morphological changes in the peritoneal membrane during the course of continuous ambulatory peritoneal dialysis (CAPD) therapy. Methods. Seventeen patients on CAPD (11 men, 6 women; average age, 48.4 ± 2.8 years [mean ± SE]) were studied. The duration of CAPD ranged from 1 to 42 months (21.7 ± 3.8 months [mean ± SE]). Urea nitrogen, creatinine, transferrin, and IgG in both serum and CAPD waste fluid were measured, and dialysate/plasma (D/P) ratios for these substances were determined. To evaluate changes in the large pores, in the peritoneal membrane, the peritoneal selectivity index (PSI) was calculated in the same manner as the urinary protein selectivity index is determined; namely, as the ratio of IgG clearance to transferrin clearance into CAPD waste fluid. Results. There was no significant correlation among the D/P ratios for urea nitrogen, creatinine, transferrin, IgG, and the duration of CAPD therapy. However, the PSI showed low-grade selectivity in patients on relatively shorter periods of CAPD therapy, and high-grade selectivity in patients with longer periods of CAPD therapy. There was a significant inverse correlation between the PSI (Y) and the duration of CAPD therapy (X) (Y = −0.007X + 0.75; r = 0.75, P < 0.05). We performed a prospective study after 12 months, and 8 patients were available to measure PSI again, and almost all patients showed a decrease in the PSI (−22.8 ± 0.8%; P < 0.02). In addition, we carried out morphological evaluation of the peritoneum in 13 patients who stopped CAPD. There was a significant difference in PSI value between those with and without peritoneal fibrotic change, while there was no significant difference in PSI values for those with and without mesothelial damage or with and without arteriolar sclerosis. Conclusions. From these results, we hypothesize that reduction in the PSI may reflect the shrinkage of large peritoneal pores and the presence of peritoneal fibrotic change in CAPD patients.

一般に糖尿病性腎症由来の血液透析患者 (DM-HD) は適正な血圧コントロールが困難である. 今回我々はDM-HD患者における透析中の血圧変化および透析前後の起立性低血圧の特徴を把握した上で, さらにamezinium metilsulfate (AM) の効果について検討した.対象は当院および関連施設における安定維持期のDM-HD, 非糖尿病性腎症血液透析患者 (non-DM-HD) 各16名である. 透析前後の臥位, 立位および透析開始直前, および透析開始後1時間毎に血圧を測定した. また体液量の指標としてクリットラインモニターを用い, 経時的変化を検討した.Non-DM-HD群とDM-HD-AM非投与群の比較検討では, 両群で同程度の除水量, 除水率にもかかわらずDM-HD-AM非投与群では, 透析開始2時間後から血圧が有意に低下したが, non-DM-HD群では明らかな血圧低下を認めなかった. 起立性低血圧に関しては, 透析前には両群で同程度の血圧低下だった. 一方, 透析後DM-HD-AM非投与群で起立による血圧低下は顕著で, non-DM-HDでは平均血圧が6.8mmHgの低下に対してDM-HDでは20.5mmHg低下した.次に, DM-HD-AM非投与群とDM-HD-AM投与群の比較検討では, 透析中の血圧はAM投与によりその低下が抑制されたが, 透析後の起立性低血圧はAM投与によって減弱されなかった.糖尿病性腎症透析患者においては, 透析による除水で透析中に血圧低下が起こりやすく, また透析後には起立性低血圧が増強される. 一方, AMは透析中の血圧低下には有効だが, 透析後の起立性低血圧には効果がないと考えられた.

目的: 近年透析人口増加に伴い, 高齢者の透析導入が増加している. そこで高齢者透析導入の特徴を把握するため, 当院における導入患者を比較検討した.対照と方法: 1989年から1998年までの間に, 血液透析に導入した719人を若年群 (65歳未満; 517名) と高齢群 (65歳以上; 202名) に分け, 導入時の臨床所見を比較した.結果: 1989年に19%であった高齢群の透析導入は, 1998年には41%に増加した. 若年群に比較し高齢群の特徴として以下の3点が挙げられた. (1) 慢性糸球体腎炎 (CGN) による導入が少なく, 腎硬化症による導入が多い. (2) 心胸比が大きく, 体液過剰を呈する率が高い. (3) クレアチニンが低く, 消化器症状を呈する率が低い. また1989, 90年に導入した145人と比較し, 1997, 98年の170人において, 高齢群で腎硬化症の割合が有意に減少し, 糖尿病性腎症 (DN) の増加がみられた. 若年群ではDNの割合が有意に増加しCGNが有意に減少した. 疾患の特徴としては若年群の中でDNはCGNに比べ心胸比, リン, 重炭酸イオンが有意に高く, 平均血圧, 尿毒窒素, クレアチニンが有意に低いという特徴があった. しかし高齢群でのDNの特徴はクレアチニンが低いことのみであった.考察: 近年高齢者の透析導入が増加し, その内訳にDNによる導入の増加が伴っていた. しかし, 若年群にみられたCGNとDNの違いは高齢になると薄らいでしまった. 高齢者の透析導入には高齢者そのものの特徴を理解し対処することが望ましいと考えられた.

Since the accumulation of intestinal putrefactive products, such as indole and phenol, is known to play a role in the exacerbation of chronic renal failure, reduction of these intestinal putrefactive products can be expected to retard the progression of renal failure. In the present study, an enteric capsule preparation containing Bifidobacterium longum(Bifidus HD) was administered orally to 27 patients with chronic renal failure(CRF) for 6 months. Though no significant effect was found in the whole group, a significant retardation of the progression of renal failure was found in patients with an initial serum creatinine levelor = 4.0 mg/dl or those with an initial serum inorganic phosphate levelor = 4.0 mg/dl. There was no adverse effect observed in any case. Bifidus HD is considered a useful tool for suppressing the progression of chronic renal failure(CRF) in the conservative period.

♦ Objectives To study changes in peritoneal function after transfer from chronic peritoneal dialysis (CPD) to hemodialysis (HD), especially the effects on peritoneal coagulation, fibrinolytic markers, and mesothelium. ♦ Design Prospective observational study. ♦ Setting A tertiary-care university hospital. ♦ Patients Nine patients who transferred from CPD to HD were enrolled in the study after giving fully informed consent. ♦ Methods After transfer to HD, the peritoneal cavity was lavaged with low glucose PD solution once per day through PD catheters left in place. Thrombin–antithrombin III complex (TAT) was measured serially as a marker of peritoneal coagulation. As fibrinolytic markers, fibrinogen/fibrin degradation products (FDP) and plasmin–α2-antiplasmin complex (PIC) were assessed. Cancer antigen 125 (CA125) was measured as a marker of mesothelial cell mass. ♦ Results Levels of peritoneal TAT and FDP were much higher than plasma levels, indicating high local fibrin turnover. Transfer to HD induced a significant fall in mean peritoneal TAT, from 115.8 ± 52.1 to 60.7 ± 21.8 ng/mL, p < 0.05. Except for 1 patient with a 20-fold increase, mean peritoneal FDP decreased significantly, from 43.6 ± 11.1 to 19.6 ± 3.5 μg/mL, p < 0.05. Mean peritoneal PIC increased significantly, from 1.9 ± 0.4 to 3.9 ± 0.6 μg/mL, p < 0.05. Peritoneal CA125 increased from 156.4 ± 57.3 to 1426.2 ± 389.4 U/mL, p < 0.05. ♦ Conclusions Peritoneal fibrin turnover was accelerated on CPD and stabilized after transfer to HD. Transfer to HD also induced mesothelial regeneration.

We report a case of immunotactoid glomerulopathy with unique histologic findings in serial biopsies. A 73-year-old man complained of developing general edema. Laboratory data on admission presented moderate renal dysfunction with nephrotic syndrome. There was no evidence of systemic disease that might cause secondary glomerulopathy. Light microscopy of the renal specimen revealed lobulation of glomerular tufts and massive endothelial deposition of hyaline-like periodic acid-Schiff-positive substance with neutrophilic infiltration. The deposits were positive for immunoglobulin by immunohistochemical stains but negative for Congo red stain. Electron microscopy disclosed the deposition of microtubular structure (60 nm in diameter) predominantly in the subendothelial area and to some extent in the subepithelial and mesangial areas. Some of the tubules were extremely large (100 to 130 nm in diameter) and displayed a unique scroll structure in cross-section. The patient was treated with two sessions of plasma exchange and subsequent oral prednisolone (30 mg/d). Proteinuria and renal dysfunction improved significantly in the following 2 months. Second and third renal biopsies revealed disappearance of the deposit along with the improvement of proteinuria and renal dysfunction. Because similar microtubular structures were found in neutrophils in the glomerulus as well as in the urinary sediment, phagocytosis was suggested as a possible mechanism for removal of the deposit.