Temperature effects of Mach-Zehnder interferometer using a liquid crystal-filled fiber

We demonstrated a simple and cost-effective method to fabricate all fiber Mach-Zehnder interferometer (MZI) based on cascading a short section of liquid crystal (LC)-filled hollow-optic fiber (HOF) between two single mode fibers by using automatically splicing technique. The transmission spectra of the proposed MZI with different LC-infiltrated length were measured and the temperature-induced wavelength shifts of the interference fringes were recorded. Both blue shift and red shift were observed, depending the temperature range. Based on our experimental results, interference fringe was observed with a maximum interferometric contrast over 35dB. The temperature-induced resonant wavelength blue-shifts 70.4 nm for the MZI with an LC length of 9.79 mm and the wavelength temperature sensitivity of -1.55 nm/°C is easily achieved as the temperature increases from 25°C to 77°C

Utility of Volume Assessment Using Bioelectrical Impedance Analysis in Critically Ill Patients Receiving Continuous Renal Replacement Therapy: A Prospective Observational Study

Background Fluid overload prior to continuous renal replacement therapy (CRRT) is an important prognostic factor. Thus, precise evaluation of fluid status is necessary to treat such patients. In this study, we investigated whether fluid assessment using bioelectrical impedance analysis (BIA) can predict outcomes in critically ill patients requiring CRRT. Methods A prospective observational study was performed in patients who were admitted to the intensive care unit and who required CRRT. BIA was conducted before CRRT; then, the ratio of extracellular water to total body water (ECW/TBW) was derived to estimate volume status. Results A total of 31 patients treated with CRRT were included. There were 18 men (58.1%), and the median age was 67 years (interquartile range, 51 to 78 years). Fourteen patients (45.2%) died within 28 days after CRRT initiation. Patients were divided into 16 with ECW/TBW ≥0.41 and 15 with ECW/TBW <0.41. Survival rate within 28 days was different between the two groups (P = 0.044). Cox regression analysis revealed a relationship between ECW/TBW ≥0.41 and 28-day mortality, but it was not statistically significant (hazard ratio, 3.0; 95% confidence interval, 0.9 to 9.8; P = 0.061). Lastly, the area under the curve of ECW/TBW for 28-day mortality was analyzed. The area under the curve of ECW/TBW was 0.73 (95% confidence interval, 0.54 to 0.92), and this was significant (P = 0.037). Conclusions Fluid status can be assessed using BIA in critically ill patients requiring CRRT, and BIA can predict mortality. Further large trials are needed to confirm the usefulness of BIA in critically ill patients

Prediction of renal recovery following sepsis-associated acute kidney injury requiring renal replacement therapy using contrast-enhanced ultrasonography

Background Microcirculatory dysfunction plays a critical role in sepsis-associated acute kidney injury (S-AKI) development; however, its impact on renal recovery remains uncertain. We investigated the association between cortical microcirculatory function assessed using contrast-enhanced ultrasonography (CEUS) and renal recovery after S-AKI needing renal replacement therapy (RRT). Methods This retrospective study included 23 patients who underwent CEUS among those who underwent acute RRT for S-AKI. In addition, we acquired data from 17 healthy individuals and 18 patients with chronic kidney disease. Renal recovery was defined as sustained independence from RRT for at least 14 days. Results Of the CEUS-derived parameters, rise time, time to peak, and fall time were longer in patients with S-AKI than in healthy individuals (p = 0.045, 0.01, and 0.096, respectively). Fourteen patients (60.9%) with S-AKI receiving RRT experienced renal recovery; and these patients had higher values of peak enhancement, wash-in area under the curve (AUC), wash-in perfusion index, and wash-out AUC than those without recovery (p = 0.03, 0.01, 0.03, and 0.046, respectively). We evaluated the receiver operating characteristic curve and found that the peak enhancement, wash-in AUC, wash-in perfusion index, and wash-out AUC of CEUS derivatives estimated the probability of renal recovery after S-AKI requiring RRT (p = 0.03, 0.01, 0.03, and 0.04, respectively). Conclusion CEUS-assessed cortical microvascular perfusion may predict renal recovery following S-AKI that requires RRT. Further studies are essential to validate the clinical utility of microcirculatory parameters obtained from CEUS to estimate renal outcomes in various etiologies and severities of kidney disease

pH-responsive high-density lipoprotein-like nanoparticles to release paclitaxel at acidic pH in cancer chemotherapy

Jae-Yoon Shin,1,* Yoosoo Yang,1,* Paul Heo,1 Ji-Chun Lee,1 ByoungJae Kong,1 Jae Youl Cho,1 Keejung Yoon,1 Cheol-Su Shin,2 Jin-Ho Seo,3 Sung-Gun Kim,4 Dae-Hyuk Kweon11Department of Genetic Engineering, College of Biotechnology and Bioengineering, and Center for Human Interface Nano Technology, Sungkyunkwan University, 2APTech Research Center, Suwon, 3Department of Agricultural Biotechnology, Seoul National University, Seoul, 4Department of Biomedical Science, Youngdong University, Chungbuk, South Korea*These authors contributed equally to this workBackground: Nanoparticles undergoing physicochemical changes to release enclosed drugs at acidic pH conditions are promising vehicles for antitumor drug delivery. Among the various drug carriers, high-density lipoprotein (HDL)-like nanoparticles have been shown to be beneficial for cancer chemotherapy, but have not yet been designed to be pH-responsive.Methods and results: In this study, we developed a pH-responsive HDL-like nanoparticle that selectively releases paclitaxel, a model antitumor drug, at acidic pH. While the well known HDL-like nanoparticle containing phospholipids, phosphatidylcholine, and apolipoprotein A-I, as well as paclitaxel (PTX-PL-NP) was structurally robust at a wide range of pH values (3.8&amp;ndash;10.0), the paclitaxel nanoparticle that only contained paclitaxel and apoA-I selectively released paclitaxel into the medium at low pH. The paclitaxel nanoparticle was stable at physiological and basic pH values, and over a wide range of temperatures, which is a required feature for efficient cancer chemotherapy. The homogeneous assembly enabled high paclitaxel loading per nanoparticle, which was 62.2% (w/w). The molar ratio of apolipoprotein A-I and paclitaxel was 1:55, suggesting that a single nanoparticle contained approximately 110 paclitaxel particles in a spherical structure with a 9.2 nm diameter. Among the several reconstitution methods applied, simple dilution following sonication enhanced the reconstitution yield of soluble paclitaxel nanoparticles, which was 0.66. As a result of the pH responsiveness, the anticancer effect of paclitaxel nanoparticles was much more potent than free paclitaxel or PTX-PL-NP.Conclusion: The anticancer efficacy of both paclitaxel nanoparticles and PTX-PL-NP was dependent on the expression of scavenger receptor class B type I, while the killing efficacy of free paclitaxel was independent of this receptor. We speculate that the pH responsiveness of paclitaxel nanoparticles enabled efficient endosomal escape of paclitaxel before lysosomal break down. This is the first report on pH-responsive nanoparticles that do not contain any synthetic polymer.Keywords: pH responsiveness, nanoparticle, apolipoprotein A-I, paclitaxe

Psychometric properties of the readiness for return to work scale in occupational rehabilitation in South Korea

This study validated the Korean version of the Readiness to Return to Work (RRTW) scale, as an assessment measure, following a musculoskeletal, work-related injury and as a measure of following return to work. The participants of this study were workers with experience in rehabilitation programs at the Workers Compensation and Welfare Service (KCOMWEL) Hospital in Korea. Factor analyses were employed to ensure the validity and reliability of the RRTW scale in claimants who were in treatment without working (the not-working group) or who had already returned to work (the working group). To test structural validity, we analyzed exploratory factor analysis (EFA) respectively for the not working group (exploratory factor analysis (EFA) (n= 200), confirmatory factor analysis (CFA) (n= 109), and the working group (n= 123). To verify concurrent validity (multidimensional and assignment approach), the variables that were identified as relevant variables in previous studies were analyzed. The not working group EFA, as shown in the original scale, had four dimensions, and one item was deleted: (1) Precontemplation (PC), (2) Contemplation (C), (3) Prepared for Action-Self-evaluative (PAS), and (4) Prepared for Action-Behavioral (PAB). The CFA revealed that a good model fit and reliability were suitable. Regarding the working group of EFA, it appeared in two dimensions as in the original scale, one item was modified from the UM scale to the PM scale, and the reliability was appropriate. Concurrent validity was satisfied based on the correlation between the RRTW factor and related variables. RRTW in the Korean version of the instrument was similar to those reported for the original scale, indicating that it may be used in research and clinical settings