Simultaneous Performance and Stability Enhancement in Intermediate Temperature Solid Oxide Fuel Cells by Powder-Atomic Layer Deposited LSCF@ZrO2 Cathodes.

Employing porous structures is essential in high-performance electrochemical energy devices. However, obtaining uniform functional coatings on high-tortuosity structures can be challenging, even with specialized processes such as atomic layer deposition (ALD). Herein, a novel method for achieving a porous composite electrode for solid oxide fuel cells by coating La0.6 Sr0.4 Co0.2 Fe0.8 O3 -δ (LSCF) powders with ZrO2 using a powder ALD process is presented. Unlike conventional ALD, powder ALD can be used to fabricate extremely uniform coatings on porous electrodes with a thickness of tens of micrometers. The powder ALD ZrO2 coating is found to effectively suppress chemical degradation of the LSCF electrodes. The cell with the powder ALD coated cathode shows a 2.2 times higher maximum power density and 60% lower thermal degradation in activation resistance than the bare LSCF cathode cell at 700-750 °C. The result demonstrated in this study is expected to have significant implications for high-performance and durable electrodes in energy conversion/storage devices.

COMPARISON OF C-PEPTIDE LEVELS IN MONOGENIC FORMS OF DIABETES WITH OTHER TYPES OF DIABETES: A SINGLE-CENTER STUDY.

Objective: This study aimed to evaluate the utility of C-peptide levels in the differentiation of monogenic forms of diabetes from type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in clinical practice. Subjects and Methods: A total of 104 patients aged >16 who visited the Dicle University's Faculty of Medicine between April 2011 and December 2020 and were diagnosed with monogenic diabetes by genetic analysis or with T1DM and T2DM were randomly selected for retrospective evaluation. The C-peptide levels of these patients at the time of diagnosis of diabetes were compared. Results: Of the 104 patients, 24 (23%) were diagnosed with maturity-onset diabetes of the young (MODY), 40 (38.5%) with T1DM, and 40 (38.5%) with T2DM. Median C-peptide levels (ng/mL) (interquartile range) were 1.78 (1.24-2.88) in MODY group, 0.86 (0.34-1.22) in T1DM group, and 2.38 (1.58-4.27) in T2DM group. Conclusions: There was a difference in C-peptide levels between MODY and T1DM groups but not between MODY and T2DM groups. As per clinical evaluations, although C-peptide levels of patients with MODY are similar to those of patients with T2DM patients, the possibility of C-peptide levels being similar to those required for T1DM diagnosis should also be considered.

Investigation of the Importance of Knee Position during Femoral Tunnel Reaming; Figure 4 versus Hyperflexion.

Introduction: We aimed to compare whether the visualisation provided by arthroscopic hyperflexion and Figure 4 has an effect on femoral tunnel placement in patients undergoing single bundle Anterior Cruciate Ligament Reconstruction (ACLR). Material and methods: We retrospectively evaluated 93 patients who underwent single-band ACLR for Anterior Cruciate Ligament (ACL) injury between 2016 and 2019. Eighty patients met the inclusion criteria with a minimum follow-up of 12 months. We divided the patients into Group 1 (figure 4) and Group 2 (hyperflexion). We analysed the demographic, radiological and functional outcomes of the patients. The functional Lysholm score, operative time, radiological Quadrant method (% proximal-distal and % anterior-posterior) measurements, tunnel lengths, axial and coronal plane angles, and iatrogenic chondral injury in the medial femoral condyle were evaluated. Results: Iatrogenic chondral injury developed in the medial femoral condyle in a total of seven patients in both groups: one patient in group 1 (Figure 4) and six patients in group 2 (Hyperflexion). Although statistically insignificant, iatrogenic medial femoral condyle damage was less in group 1. The statistical analysis between surgical operation time (p = 0.046) and tunnel lengths (p = 0.042) was significant. Conclusion: The position of figure 4 provides visualisation of lateral intercondylar notch better than hyperflexion. In the reaming stage, the medial femoral condyle is less damaged in group 1 (Figure 4). In ACLR, which has a long learning curve, short surgery time is seen as an important advantage for surgeons who have just started doing ACLR. We think that it can be used as an alternative method to hyperflexion in the learning process and maybe shorten the learning curve process.

The influence of functional pinealectomy and exogenous melatonin application on healing of a burr hole in adult rat calvaria: a histological and immunohistochemical study.

BACKGROUND: Even today, repair of the cranial defects still represents a significant challenge in neurosurgery and various options have been used for their reconstruction to date. However, there are very few studies investigating the effects of exogenous administration of melatonin (MEL) as an agent that promotes bone regeneration. The goal of this study was to investigate the effects of functional pinealectomy (Px) and exogenous MEL administration on the bone repair properties and surrounding connective tissue alterations in a rat calvaria model. MATERIALS AND METHODS: The total of 30 adult female Wistar-Albino rats was randomly divided into three groups (n = 10): control group (CO; 12 h light/12 h dark exposure), functional Px group (24 h light exposure, light-induced functional Px), and Px+MEL group (light-induced Px + MEL, 20 mg/kg/day for 12 weeks). Critical-sized burr-hole defects (diameter: 3.0 mm) were surgically created by a single operator in the calvarium of all rats, using an electric drill. Animals in Px+MEL group received MEL 20 mg/kg/day for 12 weeks. At the end of the study, bone healing and connective tissue alterations surrounding drilled defect area in the rat calvaria were determined in haematoxylin-eosin-stained and Mallory Azan slices applied in anti-bone sialoprotein. Image Pro Express 4.5 programme was used for histomorphometric calculation of areas of new bone and fibrotic tissue. Normality control was performed by Shapiro-Wilk test. Variance homogeneities were examined by Shapiro-Wilk and Levene tests; Tukey HSD test was used as a post hoc method since there was no homogeneity problem. All hypothesis tests were performed at the 0.05 significance level. RESULTS: Histological analysis showed that the bone repair process in the Px+MEL group was similar to that of the CO group, whereas the functional Px group showed a delay. Histomorphometrically, it was found that the Px group had the largest hole diameter and the most fibrotic scar area, although no binary statistical significance was found between the CO and Px+MEL groups (p = 0.910). In terms of vascularisation, it was observed that the most vascular structure was found in the Px+MEL group among the scar tissue and ossification areas, while the vascularisation was the least in the Px group (p < 0.001). CONCLUSIONS: Our findings revealed that bone repair process was impaired in functional Px group, but exogenous MEL replacement was able to restore this response. Thus, it is concluded that utilisation of MEL may improve the bone repair in calvarial defects.

Evaluation of the effects of Ankaferd haemostat application on bone regeneration in rats with calvarial defects: histochemical, immunohistochemical and scintigraphic study.

BACKGROUND: Bone wax, a haemostatic agent, is widely used in craniospinal surgical procedures for a long time, in spite of controversial results regarding its negative influence upon bone regeneration. In this experimental study, the effects of Ankaferd Blood Stopper (ABS), as an alternative haemostatic agent, were evaluated through histochemical, immunohistochemical and scintigraphic studies. MATERIALS AND METHODS: The total of 30 adult female Wistar albino rats was randomly divided into three groups: intact control group (n = 10), bone wax group (n = 10), and ABS group (n = 10). Surgically, a 3.0 mm hole in diameter was drilled on the right side of calvarium of the rats using a Class Mini Grinder set in all three groups, as described previously. At the end of 8 weeks, bone healing and connective tissue alterations surrounding drilled calvarial defect areas of the rats were determined via haematoxylin and eosin and the Mallory's trichrome staining and anti-bone sialoprotein immunohistochemistry. Image Pro Express 4.5 programme was used for histomorphometric calculation of new bone and fibrotic tissue areas. All statistical analyses were made with SPSS 25.0 and analysis of variance (one-way ANOVA) followed by Bonferroni post hoc test was performed, p < 0.001 was considered as significance level. RESULTS: Histomorphometrically, it was found that he had the largest hole diameter and the least fibrotic scar area in the bone-wax group. In the bone wax group, it was observed that the material closed the hole and there was only a fibrotic scar tissue in the area between the bone tissue at the edge of the hole and bone wax, and a fibrotic tissue was formed in the bone wax area. During the histological procedure, this bone-wax material was poured and the sections were seen as a gap in this area. In the ABS haemostat group, the smallest hole diameter and the least fibrotic scar tissue were observed. Fibrotic scar tissue close to each other was found in the ABS haemostat and bone wax groups. Histological analysis of samples also showed a statistical significance for fibrotic connective tissue area between groups (p < 0.05). Scintigraphically, osteoblastic activity related to blood flow in the animal taken from the group with application of ABS haemostat was more pronounced compared to the other two groups. CONCLUSIONS: In our study, it has been concluded that the ABS yields affirmative effects on the bone healing, while bone wax leads to negative impact on the bone regeneration. Scintigraphic, histochemical and immunohistochemical data support the affirmative impact of the ABS haemostat application upon the bone regeneration apart from the quick stop of haemorrhage.

The effect of Er,Cr:YSGG laser, fluoride, and CPP-ACP on caries resistance of primary enamel.

The aim of this in vitro study was to determine the effect of different remineralization agents and laser on caries resistance of primary enamel. In the study, 150 sound primary molars were used. The initial microhardness values were measured and the teeth were randomly assigned to ten treatment groups (n = 15): no treatment/negative control (C), NaF, APF, fluoride varnish (FV), CPP-ACP, laser (L), L + NaF, L + APF, L + FV, L + CPP-ACP. The microhardness values were measured after the treatments and the pH cycle. The obtained data were analyzed statistically. One sample from each group was examined before treatment, after treatment, and after the pH cycle with a scanning electron microscope. While microhardness values after treatment compared to baseline increased, microhardness after the pH cycle decreased compared to after treatment values in all experimental groups (p < 0.05). In regard to the difference in microhardness after the pH cycle and baseline, there were no statistically significant differences between groups C and NaF and between C and CPP-ACP (p > 0.05). There was a significant difference between groups L and L + FV (p < 0.05), while no significant difference was noted between groups L and L + NaF, L + APF, L + CPP-ACP (p > 0.05). As a conclusion, FV is more effective when used in combination with laser than laser alone. NaF, CPP-ACP, and laser may be insufficient in protecting the primary teeth against acid attacks compared to FV used with laser.

Nivolumab for relapsed or refractory Hodgkin lymphoma: real-life experience.

BACKGROUND: Reed-Sternberg cells of classical Hodgkin's lymphoma (cHL) are characterized by genetic alterations at the 9p24.1 locus, leading to over-expression of programmed death-ligand 1 and 2. In a phase 1b study, nivolumab, a PD-1-blocking antibody, produced a high response in patients with relapsed or refractory cHL, with an acceptable safety profile. PATIENTS AND METHODS: We present a retrospective analysis of 82 patients (median age: 30 years; range: 18-75) with relapsed/refractory HL treated with nivolumab in a named patient program from 24 centers throughout Turkey. The median follow-up was 7 months, and the patients had a median of 5 (2-11) previous lines of therapy. Fifty-seven (70%) and 63 (77%) had been treated by stem-cell transplantation and brentuximab vedotin, respectively. RESULTS: Among 75 patients evaluated after 12 weeks of nivolumab treatment, the objective response rate was 64%, with 16 complete responses (CR; 22%); after 16 weeks, it was 60%, with 16 (26%) patients achieving CR. Twenty patients underwent subsequent transplantation. Among 11 patients receiving allogeneic stem-cell transplantation, 5 had CR at the time of transplantation and are currently alive with ongoing response. At the time of analysis, 41 patients remained on nivolumab treatment. Among the patients who discontinued nivolumab, the main reason was disease progression (n = 19). The safety profile was acceptable, with only four patients requiring cessation of nivolumab due to serious adverse events (autoimmune encephalitis, pulmonary adverse event, and two cases of graft-versus-host disease aggravation). The 6-month overall and progression-free survival rates were 91.2% (95% confidence interval: 0.83-0.96) and 77.3% (0.66-0.85), respectively. Ten patients died during the follow-up; one of these was judged to be treatment-related. CONCLUSIONS: Nivolumab represents a novel option for patients with cHL refractory to brentuximab vedotin, and may serve as a bridge to transplantation; however, it may be associated with increased toxicity.

Clinical performance of aesthetic restorative materials in primary teeth according to the FDI criteria.

AIM: The purpose of this study is to evaluate the clinical performance of three different restorative materials in primary teeth according to the FDI criteria. MATERIALS AND METHODS: Resin-modified glass ionomer cement, compomer and composite resin restorations (n=93) were made in 31 patients. The restorations were clinically evaluated at baseline, 6th, 12th and 18th month with the FDI criteria. RESULTS: The cumulative survival rate after 18 months was found to be 90.3% for resin modified glass ionomer cement restorations, 100% for compomer restorations and 80.6% for composite resin restorations. Statistically significant increase in surface roughness, colour mismatch, anatomic form loss and marginal deterioration were detected in resin- modified glass ionomer group (p<0.05). The most frequent reason for restoration failure in composite resin group was restoration fractures. CONCLUSIONS: The resin-modified glass ionomer restorations necessitates close follow-up because of the risk of increase in surface roughness, changes in colour and loss in anatomic form and marginal adaptation. The clinical performance of compomer restorations is superior to resin-modified glass ionomer and composite resin restorations in primary teeth.

The association between mean platelet volume and infants with meconium stained amniotic fluid.

OBJECTIVE: The exact pathophysiology of meconium passage into the amniotic fluid is unknown, but it is frequently associated with fetal hypoxia. The mean platelet volume (MPV) seems to be a marker of platelet production and consumption and may be related to the severity of some diseases associated with bone marrow, hypoxia, and perinatal infections. We aimed to investigate the association between MPV levels and meconium-stained amniotic fluid (MSAF) in infants. PATIENTS AND METHODS: MPV, serum-reactive protein and hemoglobin levels, and leukocyte and thrombocyte counts were measured in 106 infants with MSAF and a comparison group of 78 healthy control infants. RESULTS: The mean MPV values of the infants with MSAF were statistically significantly lower than those of the control group (p < 0.001). There was no statistically significant difference in the hemoglobin levels or leukocyte and thrombocyte counts in the study group compared to the control group (p > 0.05). There was also no statistically significant difference in the MPV levels of the infants with meconium aspiration syndrome (MAS) compared to the infants with MSAF without MAS (p = 0.107). The optimal cut-off value for the MPV was 9.90 fl (area under the curve [AUC: 0.788]) in the infants with MSAF, with a sensitivity of 78.1% and specificity of 74.3%. CONCLUSIONS: Our data suggest that the MPV levels of infants with MSAF were significantly lower than those of healthy infants. This might be associated with a hypoxic process. However, the MPV levels of infants with MSAF and MAS were statistically similar. Thus, the MPV level could not be used to detect patients with or without severe disease.

Mean platelet volume in hepatitis A.

OBJECTIVE: Hepatitis A virus (HAV) still continues to be a serious public health problem worldwide. Mean platelet volume (MPV) is a marker of platelet function and activation. This study aimed to evaluate the relationship between MPV in acute hepatitis A patients as compared to the control group and to assess MPV as an acute phase reactant in acute hepatitis A. PATIENTS AND METHODS: Seventy-six patients were enrolled in this study. The control group consisted of 41 healthy age- and sex-matched individuals. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, prothrombin time (PT), platelet count (PC), serum albumin (ALB), and mean platelet volume (MPV) levels were recorded. The diagnosis of HAV infection was based on anti-HAV Ig M positivity. RESULTS: The mean levels of MPV in the study group were significantly statistically lower than in the control group (p < 0.001). The MPV levels revealed no correlation with the ALT, AST, ALP, and GGT levels (p > 0.05), but the MPV levels correlated with the platelet counts (p < 0.05). A 9.75 fL [area under the curve (AUC: 0.756)] optimal cutoff level of MPV with a sensitivity of 69.7% and specificity of 68.3% was determined in the children with acute hepatitis A. CONCLUSIONS: MPV levels were significantly lower in the patients with acute hepatitis A as compared to the healthy control group. This study demonstrated that MPV may be a negative acute phase reactant for acute hepatitis A. Further studies will explain the role that MPV plays in inflammation and other viral infections.

Food insecurity: experience in a tertiary health center in Turkey.

AIM: Aim of the study was to determine food insecurity in families presenting to our hospital and the sociodemographic characteristics of those families. METHODS: A survey consisting of 18 questions was administered to the parents of the patients applying to our hospital's pediatric polyclinic in September 01-30, 2011. The administered survey was adapted by us to Turkish from the Household Food Security Survey Module of the American Ministry of Agriculture. The survey was administered to all patients by the same researcher. RESULTS: The study enrolled 283 families. Of the parents filling out the survey 208 (73.5%) were mothers, 53 (18.7%) were fathers and 22 (7.8%) other relatives (grandmother, aunt and uncle). Eighty-two (29%) families were determined to be food secure, 58 (20.5%) borderline food secure, 86 (30.4%) food insecure and 57 (20.1%) severely food insecure. CONCLUSION: Food insecurity ratio in the families presenting to our hospital was found to be fairly high. In our country studies associated with food insecurity should be conducted in larger areas and a higher number of families should be enrolled.

Nanotubular array solid oxide fuel cell.

This report presents a demonstration and characterization of a nanotubular array of solid oxide fuel cells (SOFCs) made of one-end-closed hollow tube Ni/yttria-stabilized zirconia/Pt membrane electrode assemblies (MEAs). The tubular MEAs are nominally ∼5 µm long and have <500 nm outside diameter with total MEA thickness of nearly 50 nm. Open circuit voltages up to 660 mV (vs air) and power densities up to 1.3 µW cm(-2) were measured at 550 °C using H2 as fuel. The paper also introduces a fabrication methodology primarily based on a template process involving atomic layer deposition and electrodeposition for building the nanotubular MEA architecture as an important step toward achieving high surface area ultrathin SOFCs operating in the intermediate to low-temperature regime. A fabricated nanotubular SOFC theoretically attains a 20-fold increase in the effective surface, while projections indicate the possibility of achieving up to 40-fold.

Atomic scale verification of oxide-ion vacancy distribution near a single grain boundary in YSZ.

This study presents atomic scale characterization of grain boundary defect structure in a functional oxide with implications for a wide range of electrochemical and electronic behavior. Indeed, grain boundary engineering can alter transport and kinetic properties by several orders of magnitude. Here we report experimental observation and determination of oxide-ion vacancy concentration near the Σ13 (510)/[001] symmetric tilt grain-boundary of YSZ bicrystal using aberration-corrected TEM operated under negative spherical aberration coefficient imaging condition. We show significant oxygen deficiency due to segregation of oxide-ion vacancies near the grain-boundary core with half-width < 0.6 nm. Electron energy loss spectroscopy measurements with scanning TEM indicated increased oxide-ion vacancy concentration at the grain boundary core. Oxide-ion density distribution near a grain boundary simulated by molecular dynamics corroborated well with experimental results. Such column-by-column quantification of defect concentration in functional materials can provide new insights that may lead to engineered grain boundaries designed for specific functionalities.

Three-dimensional nanostructured bilayer solid oxide fuel cell with 1.3 W/cm(2) at 450 °C.

Obtaining high power density at low operating temperatures has been an ongoing challenge in solid oxide fuel cells (SOFC), which are efficient engines to generate electrical energy from fuels. Here we report successful demonstration of a thin-film three-dimensional (3-D) SOFC architecture achieving a peak power density of 1.3 W/cm(2) obtained at 450 °C. This is made possible by nanostructuring of the ultrathin (60 nm) electrolyte interposed with a nanogranular catalytic interlayer at the cathode/electrolyte interface. We attribute the superior cell performance to significant reduction in both the ohmic and the polarization losses due to the combined effects of employing an ultrathin film electrolyte, enhancement of effective area by 3-D architecture, and superior catalytic activity by the ceria-based interlayer at the cathode. These insights will help design high-efficiency SOFCs that operate at low temperatures with power densities that are of practical significance.

Enhanced oxygen exchange on surface-engineered yttria-stabilized zirconia.

Ion conducting oxides are commonly used as electrolytes in electrochemical devices including solid oxide fuel cells and oxygen sensors. A typical issue with these oxide electrolytes is sluggish oxygen surface kinetics at the gas-electrolyte interface. An approach to overcome this sluggish kinetics is by engineering the oxide surface with a lower oxygen incorporation barrier. In this study, we engineered the surface doping concentration of a common oxide electrolyte, yttria-stabilized zirconia (YSZ), with the help of atomic layer deposition (ALD). On optimizing the dopant concentration at the surface of single-crystal YSZ, a 5-fold increase in the oxygen surface exchange coefficient of the electrolyte was observed using isotopic oxygen exchange experiments coupled with secondary ion mass spectrometer measurements. The results demonstrate that electrolyte surface engineering with ALD can have a meaningful impact on the performance of electrochemical devices.

Aberration-Corrected TEM Imaging of Oxygen Occupancy in YSZ.

We present atomic-scale imaging of oxygen columns and show quantitative analysis on the occupancy of the columns in yttria-stabilized zirconia (YSZ) using aberration-corrected TEM operated under the negative Cs condition. Also, individual contributions both from oxygen column occupancy and the static displacement of oxygen atoms due to occupancy change to the observed column intensities of TEM images were systematically investigated using HRTEM simulation. We found that oxygen column intensity is governed primarily by column occupancy rather than by static displacement of oxygen atoms. Utilizing the aberration-corrected TEM capability and HRTEM simulation results, we experimentally verified that oxygen vacancies segregate near the single grain boundary of a YSZ bicrystal. The methodology and the high spatial resolution characterization tool employed in the present study provide insights into the distribution of oxygen vacancies in the bulk as well as near grain boundaries and pave the way for further investigation and atomic-scale analysis in other important oxide materials.

Enhancing charge transfer kinetics by nanoscale catalytic cermet interlayer.

Enhancing the density of catalytic sites is crucial for improving the performance of energy conversion devices. This work demonstrates the kinetic role of 2 nm thin YSZ/Pt cermet layers on enhancing the oxygen reduction kinetics for low temperature solid oxide fuel cells. Cermet layers were deposited between the porous Pt cathode and the dense YSZ electrolyte wafer using atomic layer deposition (ALD). Not only the catalytic role of the cermet layer itself but the mixing effect in the cermet was explored. For cells with unmixed and fully mixed cermet interlayers, the maximum power density was enhanced by a factor of 1.5 and 1.8 at 400 °C, and by 2.3 and 2.7 at 450 °C, respectively, when compared to control cells with no cermet interlayer. The observed enhancement in cell performance is believed to be due to the increased triple phase boundary (TPB) density in the cermet interlayer. We also believe that the sustained kinetics for the fully mixed cermet layer sample stems from better thermal stability of Pt islands separated by the ALD YSZ matrix, which helped to maintain the high-density TPBs even at elevated temperature.