50 research outputs found
Metallic Behavior of Cyclotron Relaxation Time in Two-Dimensional Systems
Cyclotron resonance of two-dimensional electrons is studied at low
temperatures down to 0.4 K for a high-mobility Si/SiGe quantum well which
exhibits a metallic temperature dependence of dc resistivity . The
relaxation time shows a negative temperature dependence, which
is similar to that of the transport scattering time obtained from
. The ratio at 0.4 K increases as the electron
density decreases, and exceeds unity when approaches the critical
density for the metal-insulator transition.Comment: 4 pages, 3 figure
Evaluation and selection of potent fluorescent immunosensors by combining fluorescent peptide and nanobodies displayed on yeast surface
Quenchbody (Q-body) is a quench-based fluorescent immunosensor labeled with fluorescent dye(s) near the antigen-binding site of an antibody. Q-bodies can detect a range of target molecules rapidly and directly. However, because Q-bodies show different antigen responses depending on the antibody used, time-consuming optimization of the Q-body structure is often necessary, and a high-throughput screening method for discriminating and selecting good Q-bodies is required. Here, we aimed to develop a molecular display method of nanobody-based “mini Q-bodies” by combining yeast surface display and coiled-coil forming E4/K4 peptide-based fluorescence labeling. As a result, the yeast-displayed mini Q-body recognizing the anti-cancer agent methotrexate (MTX) showed significant quenching and MTX-dependent dequenching on cells. To demonstrate the applicability of the developed method to select highly responsive mini Q-bodies, a small nanobody library consisting of 30 variants that recognize human serum albumin was used as a model. The best variant, showing a 2.4-fold signal increase, was obtained through selection by flow cytometry. Furthermore, the same nanobody prepared from Escherichia coli also worked as a mini Q-body after dye labeling. The described approach will be applied to quickly obtain well-behaved Q-bodies and other fluorescent biosensors for various targets through directed evolutionary approaches
Home-based aerobic exercise and resistance training
Background
The potential effects of aerobic and resistance training in patients with severe chronic kidney disease (CKD) are not fully elucidated. This study investigated the effects of a home-based exercise programme on physical functioning and health-related quality of life (HRQOL) in patients with Stage 4 CKD, equivalent to estimated glomerular filtration rate of 15–30 mL/min/1.73 m2.
Methods
Forty-six patients with Stage 4 CKD (median age, 73 years; 33 men) were randomly assigned to exercise (n = 23) and control (n = 23) groups. Exercise group patients performed aerobic exercise at 40–60% peak heart rate thrice weekly and resistance training at 70% of one-repetition maximum twice weekly at home for 6 months. Control patients received no specific intervention. Primary outcomes were distance in incremental shuttle walking test and HRQOL assessed using the Kidney Disease Quality of Life—Short Form questionnaire. Secondary outcomes included kidney function assessed with combined urea and creatinine clearance, urinary biomarkers, and anthropometric and biochemical parameters associated with CKD.
Results
Improvement in incremental shuttle walking test was significantly greater in the exercise group compared with controls (39.4 ± 54.6 vs. −21.3 ± 46.1; P < 0.001). Among Kidney Disease Quality of Life domains, significant mean differences were observed between the exercise group and the control group in work status, quality of social interaction, and kidney disease component summary outcomes (12.76 ± 5.76, P = 0.03; 5.97 ± 2.59, P = 0.03; and 4.81 ± 1.71, P = 0.007, respectively). There were greater reductions in natural log (ln)-transformed urinary excretion of liver-type fatty acid-binding protein, ln serum C-reactive protein, and acylcarnitine to free carnitine ratio in the exercise group compared with controls, with significant between-group differences of −0.579 ± 0.217 (P = 0.008), −1.13 ± 0.35 (P = 0.003), and −0. 058 ± 0.024 (P = 0.01), respectively.
Conclusions
Our 6 month home-based exercise programme improved aerobic capacity and HRQOL in patients with Stage 4 CKD, with possible beneficial effects on kidney function and CKD-related parameters
Isolated gestational proteinuria preceding the diagnosis of preeclampsia : an observational study
Introduction. Some pregnant women develop significant proteinuria in the absence of hypertension. However, clinical significance of isolated gestational proteinuria (IGP) is not well understood. This study aimed to determine the prevalence of IGP in singleton pregnancies and the proportion of women with IGP who subsequently developed preeclampsia (IGP-PE) among all PE cases. Material and methods. This was an observational study of 6819 women with singleton pregnancies at 12 centers, including 938 women with at least once determination of protein-to-creatinine ratio (P/Cr). Significant proteinuria in pregnancy (SPIP) was defined as P/Cr (mg/mg) level >0.27. IGP was defined as SPIP in the absence of hypertension. Gestational hypertension (GH) preceding preeclampsia (GH-PE) was defined as preeclampsia (PE) in which GH preceded SPIP. Simultaneous PE (S-PE) was defined as PE in which both SPIP and hypertension occurred simultaneously. Results. IGP and PE were diagnosed in 130 (1.9%) and 158 (2.3%) of 6819 women, respectively. Of 130 women with IGP, 32 (25%) progressed to PE and accounted for 20% of all women with PE. Hence, women with IGP had a relative risk of 13.1 (95% CI; 9.2-18.5) for developing PE compared with those without IGP [25% (32/130) vs. 1.9% (126/6689)]. At diagnosis of SPIP, P/Cr levels already exceeded 1.0 more often in women with S-PE than in those with IGP-PE [67% (33/49) vs. 44% (14/32), respectively, p = 0.031]. Conclusions. IGP is a risk factor for PE, and IGP-PE accounts for a considerable proportion (20%) of all PE
Late-diagnosed cesarean scar pregnancy resulting in unexpected placenta accreta spectrum necessitating hysterectomy
Cesarean scar pregnancy (CSP) is a rare complication involving the implantation of the gestational sac in a cesarean delivery scar. The authors report a case of unexpected placenta accreta spectrum (PAS) caused by late diagnosed CSP, necessitating emergent hysterectomy. A 28-year-old Japanese woman with two previous cesarean deliveries presented to our hospital at 11 weeks of gestation with abnormal transvaginal ultrasound findings obtained at another hospital;however, transabdominal ultrasound revealed that the fetus was already present in the uterine cavity at this time. At 28 weeks, there was no evidence of placenta previa. The woman developed preeclampsia at 29 weeks, and a cesarean section was conducted. Intraoperative findings confirmed PAS, and hysterectomy was conducted immediately
Stereocontrolled Synthesis of Triols Containing Four Asymmetric Centers: Application of <i>C</i>,<i>O</i>‑Chelated Germyl Enolates to a Diastereoselective Aldol Reaction
The treatment of α,β-unsaturated
ketones with divalent
germanium salts cleanly generated <i>C</i>,<i>O</i>-chelated germyl enolates. The aldol reactions of the chelated enolates
with the aldehydes achieved a high diastereoselectivity in the construction
of the five-membered aldol adducts. Furthermore, the subsequent transformation
of the Ge–C bond in the aldol adduct enabled the stereocontrolled
synthesis of triols bearing four asymmetric centers