Low SDS Research Articles

“Predicting diabetic kidney disease in youth with type 1 diabetes: Insights from genetic risk assessment”

ObjectiveDiabetic kidney disease (DKD) is influenced by multiple factors, yet its precise progression mechanisms remain largely unclear. This study aimed to create a clinical risk-scoring system based on genetic polymorphisms in the AFF3, CARS, CERS2, ERBB4, GLRA3, RAET1L, TMPO, and ZMIZ1 genes. MethodsThe study included a DKD group diagnosed with diabetic kidney disease before age 18 and a WDC group matched by age, gender, and age at diabetes diagnosis. Genetic data and clinical data from diabetes diagnosis to moderately increased albuminuria (MIA) detection were compared between the groups. ResultsAmong 43 DKD cases, 22 were girls and 21 were boys. At MIA diagnosis, mean body weight SDS was −0.24 ± 0.94, height SDS was 0.34 ± 1.15, and BMI SDS was −0.26 ± 0.94. Systolic blood pressure was at the 72nd percentile (2–99), and diastolic blood pressure was at the 74th percentile (33–99). Significant differences in rs267734, rs267738, and rs942263 polymorphisms were found between DKD and non-complication diabetic groups (13[30.2 %] vs 5[11.6 %], p = 0.034; 14[32.6 %] vs 5[11.6 %], p = 0.019; 26[60.5 %] vs 40[93 %], p < 0.001). ConclusionSeveral factors were identified as significant in DKD onset, including low follow-up weight SDS, elevated diastolic blood pressure, presence of rs267734, and absence of rs942263 polymorphisms. The model demonstrated a specificity of 81.4 % and a sensitivity of 74.4 %.

Assessing Genotoxicity of Bovine Pericardium in Guided Tissue Regeneration: Bacterial Reverse Mutation Assay With Exogenous Metabolic Activation.

Introduction Guided tissue regeneration (GTR) is integral to periodontal therapy, facilitating the repair of osseous defects. Due to the widespread use of bovine pericardium (BP) in GTR, a thorough investigation into its genotoxicity is essential for patient safety and treatment efficacy. This study aimed to evaluate the genotoxic effects of local BP in GTR for periodontal osseous defects. Materials and methods The Bacterial Reverse Mutation Assay (Ames test) was used to assess the genotoxic potential of local BP. An exogenous metabolic activation system was employed to evaluate the direct effects of the material on bacterial cells. Results The study investigated the mutagenic effects of local BP across multiple strains of Salmonella typhimurium, utilizing concentrations ranging from 0.3125 mg/plate to 5 mg/plate. While some variability was observed in revertant counts, the generally low SDs suggest a consistent response to the test substance. The maximum revertant count for each strain did not significantly exceed the mean values, indicating the absence of notable outliers or exceptionally high revertant counts at any specific concentration. Based on the data and toxicity assessment criteria, there is insufficient evidence to suggest that the experimental material induces genotoxic effects in the tested bacterial strains under the provided experimental conditions. Conclusion This study assessed the mutagenic potential of local BP membranes used in GTR with the Ames test. Results showed no evidence of mutagenicity, as revertant counts did not exceed twice the negative control in all bacterial strains with exogenous metabolic activation. This suggests that bovine pericardium membranes are safe for medical use under the test conditions. The study highlights the biocompatibility and non-mutagenic nature of BP membranes in GTR for periodontal therapy.

Analysis of soybean protein aggregates by SDS-PAGE using low concentration SDS extract

Analysis of soybean protein aggregates by SDS-PAGE using low concentration SDS extract

Associations of circulating GDF15 with combined cognitive frailty and depression in older adults of the MARK-AGE study.

Growth differentiation factor-15 (GDF15) might be involved in the development of cognitive frailty and depression. Therefore, we evaluated cross-sectional associations of plasma GDF15 with combined cognitive-frailty-and-depression in older (i.e. ≥ 55years) and younger adults of the MARK-AGE study. In the present work, samples and data of MARK-AGE ("European study to establish bioMARKers of human AGEing") participants (N = 2736) were analyzed. Cognitive frailty was determined by the global cognitive functioning score (GCF) and depression by the Self-Rating Depression Scale (SDS score). Adults were classified into three groups: (I) neither-cognitive-frailty-nor-depression, (II) either-cognitive-frailty-or-depression or (III) both-cognitive-frailty-and-depression. Cross-sectional associations were determined by unadjusted and by age, BMI, sex, comorbidities and hsCRP-adjusted linear and logistic regression analyses. Cognitive frailty, depression, age and GDF15 were significantly related within the whole study sample. High GDF15 levels were significantly associated with both-cognitive-frailty-and-depression (adjusted β = 0.177 [0.044-0.310], p = 0.009), and with low GCF scores and high SDS scores. High GDF15 concentrations and quartiles were significantly associated with higher odds to have both-cognitive-frailty-and-depression (adjusted odds ratio = 2.353 [1.267-4.372], p = 0.007; and adjusted odds ratio = 1.414 [1.025-1.951], p = 0.035, respectively) independent of age, BMI, sex, comorbidities and hsCRP. These associations remained significant when evaluating older adults. We conclude that plasma GDF15 concentrations are significantly associated with combinedcognitive-frailty-and-depression status and, with cognitive frailty and depressive symptoms separately in old as well as young community-dwelling adults.

Redoxless Electrochemical Capacitance Spectroscopy for Investigating Surfactant Adsorption on Screen-Printed Carbon Electrodes

Electrochemical impedance spectroscopy (EIS) is a sensitive analytical method for surface and bulk properties. Classical EIS and derived electrochemical capacitance spectroscopy (ECS) with a redox couple are label-free approaches for biosensor development, but doubts arise regarding interpretability when a redox couple is employed (redox EIS) due to interactions between electroactive probes and interfacial charges or forced potential. Here, we demonstrated redoxless ECS for directly determining surfactant adsorption on screen-printed carbon electrodes (SPCEs), validated through a simulation of equivalent circuits and the electrochemistry of electronic dummy cells. Redoxless ECS provides excellent capacitance plot loci for quantifying the interfacial permittivity of di-electric layers on electrode surfaces. Redoxless ECS was compared with redox EIS/ECS, revealing a favorable discrimination of interfacial capacitances under both low and high SDS coverage on SPCEs and demonstrating potential for probeless (reagentless) sensing. Furthermore, the proposed method was applied in an electrolyte without a redox couple and bare electrodes, obtaining a high performance for the adsorption of surfactants Tween-20, Triton-X100, sodium dodecyl sulfate, and tetrapropylammonium bromide. This approach offers a simple and straightforward means for a semi-quantitative evaluation of small molecule interactions with electrode surfaces. Our proposed approach may serve as a starting point for future probeless (reagentless) and label-free biosensors based on electrochemistry, eliminating disturbance with surface charge properties and minimizing forced potential bias by avoiding redox couples. An unambiguous and quantitative determination of physicochemical properties of biochemically recognizable layers will be relevant for biosensor development.

Association of sleep quality with myopia based on different genetic risk levels.

To analyse the association of sleep quality with myopia under different genetic risk (GR) levels. A cross-sectional survey of students aged 9-14y in Wenzhou, China, was conducted. Refraction without cycloplegia and ocular parameters were measured. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Seventeen single nucleotide polymorphisms (SNPs) were replicated by association analysis and used to compute the GR score (GRS). Possible confounders were assessed by a questionnaire that collected information about the children and their parents. Generalized linear models were used to analyse the sleep quality, the GR, and their interaction effects on the risk of myopia. Out of 1354 children included in this study, 353 (26.07%) had sleep disturbances. The GRS ranged from 4.49 to 12.89 with a mean of 7.74±1.23, and the participants were divided into a low GR group, a moderate GR group and a high GR group according to the GRS quartile. In the generalized linear model, the children with sleep disturbances and high GR had a higher risk of myopia than those without sleep disturbances and with low GR (OR=1.59, 95%CI: 1.12-2.25; OR=1.88, 95%CI: 1.23-2.88, respectively). Compared to those with low GR and SDs, children with high GR with or without SDs had a higher risk of myopia (OR=4.88, 95%CI: 2.03-11.71; OR=1.70, 95%CI: 1.06-2.72, respectively). The prevalence of sleep disturbances in elementary school students in Wenzhou was 26.07%. There is a significant interaction between sleep disturbances and a high GR of myopia, suggesting that a high GR of myopia may increase children's sensitivity to sleep disturbances. This study indicates that children with a high GR of myopia need to achieve adequate sleep duration and excellent sleep quality.

Application of Refined Nursing Combined with Comprehensive Treatment of Traditional Chinese and Western Medicine in Gastrointestinal Dysfunction after Tumor Operation.

After surgical treatment, the gastrointestinal function of tumor patients is inhibited for a short time. Refined nursing is beneficial to the recovery of gastrointestinal function of tumor patients after operation. Traditional Chinese medicine and Western medicine have their own advantages in the treatment of gastrointestinal dysfunction after tumor operation and the combined application of the two is more ideal. Therefore, on the premise of refined nursing, we should carefully study the efficacy of integrated traditional Chinese and Western medicine in the treatment of postoperative gastrointestinal dysfunction in tumor patients. Fifty patients with gastrointestinal dysfunction after tumor surgery admitted to Xiamen University Affiliated Zhongshan Hospital from June 2021 to August 2022 were retrospectively selected. Twenty two of them received refined care + Western medicine (control group, CG) and the other 28 received refined care + Western medicine + moxibustion and thumb-tack needle Chinese medicine (observation group, OG). We compared the recovery of gastrointestinal function, inflammatory factors, negative emotions, sleep quality, length of stay, medical expenses, and adverse reactions. The postoperative recovery effect of gastrointestinal function in the OG was better than that in the CG. The IL-8 level and TNF -α level in OG were lower than those in CG. Relative to CG, the OG had significantly low SDS scores, SAS scores, PSQ1 scores, length of hospital stay, and medical expenses. The OG incidence of adverse reactions was 28.57%; it was significantly lower than 59.09% in the CG. Refined nursing with integrated Chinese and Western medicine therapeutic interventions can promote the recovery of gastrointestinal tract function, relieve anxiety and depression, and improve sleep quality in patients with postoperative gastrointestinal dysfunction after tumor surgery.

Poor Sleep in Community-Dwelling Polysubstance Users: Association With Khat Dependence, Metacognition, and Socio-Demographic Factors.

PurposePoor sleep and cognitive deficits are often associated with increased drug use. However, no study has addressed the relationship between poor sleep, substance dependence, and metacognitive deficit in polysubstance users.MethodsThis was a cross-sectional study with a simple random sampling involving community-dwelling polysubstance users (n = 326, age = 18–43 years) in Mizan, Ethiopia. Participants completed a brief sleep questionnaire, severity of dependence on khat (SDS-Khat), a brief meta-cognition questionnaire, and a socio-demographic survey.ResultsMajority (56.4%) of the polysubstance users had sleep disturbance. Chronic health conditions [adjusted odds ratio (AOR) = 2.52, 95% confidence interval (CI) 1.31–4.85], chronic conditions in the family (AOR = 2.69, 95% CI 1.40–5.20), illiterate-primary level of educational status (AOR = 2.40, 95% CI 1.30–4.04), higher SDS-Khat score (AOR = 1.39, 95% CI 1.13–1.72), and lower meta-cognition score (AOR = 0.90, 95% CI 0.84–0.97) predicted poor sleep in the polysubstance users. Moreover, low metacognition score and high SDS score also predicted additional sleep disturbances like chronic sleep insufficiency, lethargy and restlessness after nighttime sleep, socio-occupational dysfunctions, and daytime disturbances in polysubstance users.ConclusionPoor sleep, severe khat dependence, and metacognitive deficits are common in community polysubstance users. Moreover, poor sleep is associated with higher khat dependence, lower metacognitive ability, lower educational status, and the presence of chronic conditions in polysubstance users or their families.

Evaluation of starch digestibility of Andean crops oriented to healthy diet recommendation

ABSTRACT Starchy Andean crops are often underutilized by consumers, despite their nutritional properties. The starch digestibility of a food is an indicator of its nutritional quality, mainly to prevent cardiometabolic food-related diseases. Limited information on Andean crops’ starch digestibility restricts nutritionists for designing adequate nutrition recommendations. This research evaluates the in-vitro starch digestibility of nine Andean crops flours and provides the knowledge, attitudes, and practices (KAP) survey about them among Ecuadorian nutritionists. The results were analyzed with a principal component analysis (PCA) using starch digestion characteristics (rapidly digested starch, RDS; slowly digested starch, SDS; resistant starch, RS; and estimated glycemic index, eGI). The findings showed that the studied crops could be divided into three groups: (1) Puca shungo potato with high RS, low RDS, SDS, and eGI. (2) Melloco, zarandaja, firiguero, and centenario with low RDS, SDS, eGI, and middle RS; (3) finally, quinoa, amaranth, maca, and arracacha with high RDS, SDS, low RS, and middle to high eGI. In addition, the KAP survey indicated that nutritionists lack knowledge about the starch digestibility of Andean crops, despite having positive attitudes toward recommending them. Our results would allow nutritionists to design healthy diet recommendations.

Repopulation of decellularised porcine pulmonary valves in the right ventricular outflow tract of sheep: Role of macrophages

The primary objective was to evaluate performance of low concentration SDS decellularised porcine pulmonary roots in the right ventricular outflow tract of juvenile sheep. Secondary objectives were to explore the cellular population of the roots over time. Animals were monitored by echocardiography and roots explanted at 1, 3, 6 (n = 4) and 12 months (n = 8) for gross analysis. Explanted roots were subject to histological, immunohistochemical and quantitative calcium analysis (n = 4 at 1, 3 and 12 months) and determination of material properties (n = 4; 12 months). Cryopreserved ovine pulmonary root allografts (n = 4) implanted for 12 months, and non-implanted cellular ovine roots were analysed for comparative purposes. Decellularised porcine pulmonary roots functioned well and were in very good condition with soft, thin and pliable leaflets. Morphometric analysis showed cellular population by 1 month. However, by 12 months the total number of cells was less than 50% of the total cells in non-implanted native ovine roots. Repopulation of the decellularised porcine tissues with stromal (α-SMA+; vimentin+) and progenitor cells (CD34+; CD271+) appeared to be orchestrated by macrophages (MAC 387+/ CD163low and CD163+/MAC 387−). The calcium content of the decellularised porcine pulmonary root tissues increased over the 12-month period but remained low (except suture points) at 401 ppm (wet weight) or below. The material properties of the decellularised porcine pulmonary root wall were unchanged compared to pre-implantation. There were some changes in the leaflets but importantly, the porcine tissues did not become stiffer. The decellularised porcine pulmonary roots showed good functional performance in vivo and were repopulated with ovine cells of the appropriate phenotype in a process orchestrated by M2 macrophages, highlighting the importance of these cells in the constructive tissue remodelling of cardiac root tissues.

493 Using human monogenic disease to quantify the contribution of fetal insulin to birth weight

Fetal insulin affects birth weight, but the extent of this relationship has not been established in humans, nor whether it has any implications for postnatal growth. We sought to investigate this by studying birth size and postnatal growth in individuals with monogenic diseases which result in absent insulin secretion in utero. We studied birth size in individuals with a homozygous insulin gene (INS) mutation or pancreatic agenesis (n=64 for weight, n=17 for length) born after 31 weeks gestation and compared with international growth standards for gestational age and sex (SDS). Postnatal growth was studied in individuals with INS mutations. We analyzed serial measures of weight and length until the age of four years (n=10 and 9, respectively) and most recent available weight and height (n=16 and 15, respectively). In all individuals birth weight and length were low (median (IQR) SDS -3.11 (-3.53,-2.61) and -2.86 (-3.62,-1.90), respectively). Birth weight adjusted to 40 weeks gestation was 1711 g (95% CI 1601,1821 g) vs expected of 3320 g (Fig. 1), showing non-insulin-mediated growth represents 52% of normal birth weight at term. Catch-up growth was rapid with median (IQR) weight and length SDS -0.27 (-0.37,-0.17) and -0.30 (-1.33,0.002), respectively, at 12 months, and 0.02 (-0.35,0.78) and 0.00 (-0.34,0.21), respectively, at 24 months (Fig. 2). Most recent available weight and height SDS were 0.19 (-0.67,1.33) and -0.78 (-1.78,-0.19), respectively. Monogenic diseases resulting in absent fetal insulin have enabled us to answer fundamental questions about early growth in humans. Ultimately, fetal insulin accounts for half of birth weight at term and could be an important cause of fetal growth restriction that is characterised by rapid catch-up growth. Future studies investigating outcomes arising from low and high birth weight should determine differences in insulin and non-insulin-mediated fetal growth, and consider whether they might have different implications for pregnancy outcomes and long-term risk of disease.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Serum Levels of Asprosin, a Novel Adipokine, Are Significantly Lowered in Patients with Acromegaly.

Background Asprosin is a novel identified adipokine secreted mainly by white adipose tissue, which is elevated in metabolic diseases such as diabetes and obesity. Acromegaly is a syndrome caused by pituitary growth hormone (GH) cell adenoma with excessive GH secretion. Serum adipocytokines levels may be involved in abnormal glycolipid metabolism in acromegaly patients. Objectives To investigate serum asprosin levels in acromegaly patients and its correlation with high GH levels and glucolipid metabolic parameters. Methods A retrospective case-control study was conducted and 68 acromegaly patients and 121 controls were included in this study. Clinical information and laboratory examinations were collected and serum asprosin levels were measured by commercial ELISA kits. Results Serum asprosin levels in acromegaly patients were significantly lower than controls (P < 0.001). Serum asprosin levels in patients with the course of acromegaly ≥5 years (compared with <5 years), high area under curve of growth hormone (GH-AUC) after 75 g oral glucose tolerance test (OGTT) (compared with low GH-AUC patients), and high IGF-1 SDS group (compared with low IGF-1 SDS group) were significantly reduced (all P < 0.05). Serum asprosin levels in acromegaly patients were negatively correlated with the course of acromegaly, IGF-1 SDS, nadir growth hormone value (GH-Nadir), and GH-AUC after OGTT. Multiple stepwise linear regression indicated that acromegaly was an independent influencing factor of serum asprosin levels. According to serum asprosin levels tertiles, the risk of acromegaly in the lowest group was 2.67 times higher than the highest group (OR ＝ 3.665, 95% CI 1.677 ∼ 8.007, P=0.001), and the increased risk of the lowest group still existed after adjusting for gender, age, BMI, and TC (Model 2). Conclusions Serum asprosin levels in acromegaly patients are lowered, which may be related to increased blood glucose and reduced body fat mass caused by long-term high GH levels exposure.

Core-shell structured magnetic covalent organic frameworks for magnetic solid-phase extraction of diphenylamine and its analogs.

Core-shell structured magnetic covalent organic frameworks (Fe3O4@COFs) were synthesized via a facile approach at room temperature using 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 2,5-dibromo-1,4-benzenedicarboxaldehyde (DBDA) as two building blocks for the first time. The Fe3O4@COFs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), nitrogen adsorption-desorption isotherms, and zeta potentiometric analysis. The Fe3O4@COFs had a high specific surface area (141.94 m2·g-1) and uniform pore size distribution (average 4.53nm). They also demonstrated good magnetic response (32.49 emu·g-1) and good thermal and chemical stabilities. Furthermore, adsorption experiments were conducted to evaluate the adsorption capacities and adsorption times of Fe3O4@COFs to diphenylamine (DPA) and its analogs, including benzidine (BZ), 1-naphthylamine (1-NA), 4-phenylphenol (4-PP), and O-tolidine (O-TD). From the experimental results, the maximum adsorption capacities of DPA, 1-NA, 4-PP, BZ, and O-TD were calculated as 246.25, 95.20, 85.85, 107.20, and 123.55 mg·g-1, respectively. A duration of 20min was sufficient for adsorption. The Fe3O4@COFs were explored as adsorbents for magnetic solid-phase extraction (MSPE) of DPA and its analogs, and the MSPE parameters, including adsorbent dosage, extraction time, pH, ionic strength, desorption solvent, desorption time, and desorption frequency were optimized. Combined with HPLC using diode-array detection, a simple, fast, and sensitive method was proposed to detect DPA and its analogs, which exhibited good linearity (r >0.9946) in the range of 0.1-100 μg·mL-1. Moreover, the low limits of detection (ranging from 0.02 to 0.08 μg·mL-1, S/N=3), low limits of quantitation (ranging from 0.05 to 0.30 μg·mL-1, S/N=10), good precision with low relative SDs (<5.86% for intra-day and <6.44% for inter-day) were obtained. Finally, Fe3O4@COFs were applied to the effective MSPE of DPA and its analogs in actual samples chosen from the natural environment, and good recoveries (ranging from 79.97 to 122.52%) were observed.

The effect of sodium dodecyl sulfate concentration on the aggregation behavior of Aβ (1–42) peptide: Molecular dynamics simulation approach

Beta-amyloid (1–42) is the most effective peptide in the formation of inter-synaptic aggregate structures. These complex structures lead to disruption of the neural network and the development of Alzheimer's disease. Here, the effect of sodium dodecyl sulfate concentration on Aβ (1–42) structure has been investigated by molecular dynamics simulation. The calculations were performed at concentrations lower than and above than the critical micelle concentration. Two single and six peptide systems were used for each concentration. Calculations were also repeated in the absence of sodium dodecyl sulfate. The secondary structure of Aβ (1–42) was calculated in the designed systems. The results showed that the dominant secondary structure in monomeric systems is the helix. Also, the calculation of the Aβ (1–42) secondary structure shows that the behavior of the peptides is heterogeneous in the hexamer systems. The length of the Lys28-Ala42 salt bridge was calculated in different systems as criterion of peptide toxicity. The results showed that the length of the salt bridge is increased at both SDS concentrations. The radial distribution function was used to investigate the interaction of the peptide with SDS. The result revealed that the distribution of SDS molecules around the amyloid-β peptide residues is great in the presence of low SDS concentration. Also, the interaction intensity between the peptide and SDS at low SDS concentrations is higher than that at high SDS concentration.

Development of an instrumented thoracoscopic surgical trainer for objective evaluation of esophageal atresia/tracheoesophageal fistula repair.

Operative repair of complex conditions such as esophageal atresia and tracheoesophageal fistula (EA/TEF) is technically demanding, but few training opportunities exist outside the operating theater for surgeons to attain these skills. Learning them during surgery on actual neonates where the stakes are high, margins for error narrow, and where outcomes are influenced by technical expertise, is problematic. There is an increasing demand for high-fidelity simulation that can objectively measure performance. We developed such a simulator to measure force and motion reliably, allowing quantitative feedback of technical skill. A 3D-printed simulator for thoracoscopic repair of EA/TEF was instrumented with motion and force tracking components. A 3D mouse, inertial measurement unit (IMU), and optical sensor that captured force and motion data in four degrees of freedom (DOF) were calibrated and verified for accuracy. The 3D mouse had low average relative errors of 2.81%, 3.15%, and 6.15% for 0mm, 10mm offset in Y, and 10mm offset in X, respectively. This increased to - 23.5% at an offset of 42mm. The optical sensors and IMU displayed high precision and accuracy with low SDs and average relative errors, respectively. These parameters can be a useful measurement of performance for thoracoscopic EA/TEF simulation prior to surgery. Graphical abstract Inclusion of sensors into a high-fidelity simulator design can produce quantitative feedback which can be used to objectively asses performance of a technically difficult procedure. As a result, more surgical training can be done prior to operating on actual patients in the operating theater.

Tunable stability of oil-containing foam systems with different concentrations of SDS and hydrophobic silica nanoparticles

Experiment and molecular dynamics simulation were carried out to study the tunable stability of oil-containing SDS-stabilized Nitrogen-in-water foam. The experimental results show that the foam stability could be tuned by the concentrations of SDS and modified SiO2 nanoparticles. In the foam systems with a low SDS concentration (0.2 wt.%), the foams show poor stability and the foam stability was almost not affected by the addition of modified SiO2 nanoparticles. The foam stability was greatly improved at moderate SDS concentration (0.5 wt.%), it enhanced first and then weakened with the increase of modified SiO2 concentration, and the half-life time achieved a maximum value of 1292 s at 0.05 wt.% modified SiO2. However, at high SDS concentration (0.8 wt.%), the foam stability was pretty good except for when the modified SiO2 concentration is too high (>0.2 wt.%). The microscopic mechanism was obtained by investigating the structural and dynamic properties of the foam film. The simulation work showed consistent results of foam stability with the experimental results. Moreover, it also revealed that the concentration and configuration of SDS will affect its interaction with SiO2 and oil molecule, which is critical to foam stability.

Study of O/W emulsion stability in presence of SDS and graphitic carbon nitride (g-C3N4) nanosheets

Surfactants are greatly used to facilitate the formation of O/W emulsions and they have a noticeable effect on the emulsions stability. Recently the stability of emulsions is recently investigated in the presence of different nanoparticles. The effect of graphitic carbon nitride (g-C3N4) nanosheets on the stability of O/W emulsion in the presence of anionic surfactant SDS is studied in this work. Using equilibrium interfacial tension measurements, it was shown that g-C3N4 nanosheets are not surface active, but the interfacial tension of SDS solutions decreases by adding g-C3N4 nanosheets. The emulsion stability of oil/SDS aqueous solution in the absence and presence of g-C3N4 nanosheets was studied and it was observed that g-C3N4 nanosheets increase the stability of oil/water emulsions specially at low SDS concentrations.

SUN-261 Growth Patterns over Two Years after Birth According to the Birth Weight and Length Percentile in Children Born Preterm

Purpose : This study aimed to analyze growth patterns during the first two years after birth according to the birth weight and length percentile in children born preterm, and to investigate factors affecting postnatal growth of these children. Methods : Eighty-two preterm neonates with a gestational age below 37 weeks who followed up until 24 months of corrected age (CA) were retrospectively reviewed. Length, weight and head circumference were measured at birth, 6, 12, 18, and 24 months. Data were analyzed between children born small for gestational age (SGA) and those born appropriate for gestational age (AGA). Results : Most preterm infants born SGA grew higher than -2 SDS in length during the first 6 months. Compared to AGA group, SGA group had a low length SDS at 24 months of CA(-0.87±1.11 vs -0.09±1.06, P=0.01). There was no significant difference in the rate of growth failure (length standard deviation score [SDS] <-2 at 24 months of CA) between SGA and AGA group (15.8 % vs 4.3%, P=0.13). Multivariable logistic regression analysis showed that length below 10th percentile at birth (odds ratio [OR], 47.47; 95% CI, 2.02-1117.13, P=0.02) and longer duration of in neonatal intensive care (NICU) (OR, 1.06; 95% CI, 1.01-1.11, P=0.02) were associated with a decrease of length SDS (lower than -1) at 24 months of CA. Conclusion : Whether SGA or not, most of preterm infants grow higher than -2 SDS during first 2 years. Birth length SDS and length velocity are one of the important factors affecting length SDS at 24 moths of CA in children born SGA.

Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c.

This study presents the structural, kinetic and thermodynamic characterizations of previously unknown submicellar concentrations of SDS-induced molten globule (MGSDS) state of a highly negatively charged base-denatured ferricytochrome c (UB-state) at pH ∼12.8 (±0.2). The far-UV CD, near-UV CD, ANS-fluorescence data of UB-state in the presence of different concentrations of SDS indicate that the submicellar concentrations of SDS (≤0.4 mM) transform the UB-state to MGSDS-state. The MGSDS-state has native-like α-helical secondary structure but lacks tertiary structure. The free energy change (ΔG°D) for UB→ MGSDS transition determined by far-UV CD (∼2.7 kcal mol-1) is slightly higher than those determined by fluorescence (∼2.0 kcal mol-1) at 25°C. At very low SDS and NaCl concentrations, the MGSDS-state undergoes cold denaturation. As SDS concentration is increased, the thermal denaturation temperature increases and the cold denaturation temperature decrease. Kinetic experiments involving the measurement of the CO-association rate to the base-denatured ferrocytochrome c at pH ≈12.8 (±0.2), 25°C indicate that the submicellar concentrations of SDS restrict the internal dynamics of base-denatured protein.

Synthesis of cationic alkylated chitosans and an investigation of their rheological properties and interaction with anionic surfactant

Two methods were used to alkylate high MW chitosan with glycidyltrimethylammonium chloride (GTAC) in order to produce chitosan derivatives that are water-soluble throughout the pH range. In addition, a novel chitosan derivative was created by alkylating one of the products with the GTAC analogue Quab 342 containing C12 alkyl chains. The phase behaviour and rheological characteristics of the chitosan derivatives were studied in the presence of anionic surfactant. The derivatives were found to form soluble complexes at low and high SDS concentrations and that the Quab 342 derivative was able to form gels.