Reliability of lower limb strength assessment in female team sport athletes.

BACKGROUND: Lower limb injury rates have increased dramatically in line with increased female sport participation levels. Muscle strength is a modifiable lower limb injury risk factor, guiding performance monitoring and rehabilitation. OBJECTIVES: The aim of this study was to investigate the test-retest reliability of isokinetic and isometric lower limb peak torque to body mass of muscles acting on the hip, knee, and ankle in female team sport athletes. It was hypothesised the test-retest reliability would be good (intraclass correlation coefficients (ICC) ≥ 0.75). METHODS: Thirty-eight female athletes (Australian Rules Football = 18, netball = 12, soccer = 8) aged 16-35 years participated in this study. Participants performed isokinetic (60°/s and 120°/s) and isometric testing on a Biodex Isokinetic Dynamometer on three separate days. RESULTS: Poor to good reliability was demonstrated for all joint movements (ICC = 0.38-0.88) with small to moderate effect sizes (0.00-0.43) and typical errors (5.65-24.49). CONCLUSION: Differences in peak torque to body mass were observed between sessions one and two and/or one and three, demonstrating a learning effect. Therefore, three testing sessions, and/or the inclusion of a familiarisation session, is recommended for future assessments in populations unfamiliar with dynamometry.

The interaction between wheat and pea protein influences the final chemical and sensory characteristics of extruded high moisture meat analogs.

Plant-based meat analog products, including those produced by extrusion processing, have become increasingly popular. Complete comprehension of the texturization mechanism and the formation of fibrousness would help improve existing products and extend the variety of plant sources used. Therefore, this study aimed to provide improved insight into the mechanism of texturization during the processing of high-moisture meat analog (HMMA) products. Blends with different wheat and pea protein ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wheat:pea) were extruded at a screw speed of 400 rpm, two different moisture contents (50% and 55%), and a feed rate of 90 g/min using a co-rotating twin-screw extruder. Extrudates were analyzed for their texture, free sulfhydryl groups, disulfide bonds, and solubility in different extractants relative to the raw ingredient blends. In addition, a sensory analysis was conducted using the rapid and cost-effective "rate-all-that-apply" (RATA) methodology. The interplay between the two protein types had synergistic effects on the system parameters torque, pressure, and specific mechanical energy, as well as on some textural and sensory parameters. Molecular analyses were not influenced by the interplay between wheat and pea protein as the molecular analyses followed linear trends with the pea inclusion level. Analysis of protein solubility suggests that the texturization mechanism differs slightly depending on the protein type. It is suggested that the texturization of wheat protein depends highly on disulfide bonds, whereas the texturization of pea protein relies on the combination of disulfide bonds and non-covalent interactions. Additionally, RATA was found to be a valuable tool for HMMA products.

High methoxyl pectin can improve the extrusion characteristics and increase the dietary fiber content of starch-cellulose extrudates.

Improving total dietary fiber content while maintaining the texture/expansion of extruded products is a challenge. Pectin has a dual function; it is a source of dietary fiber and it also functions as a hydrocolloid, which could improve the texture of high-fiber extruded foods. The objective of this study was to evaluate the impacts of pectin types from citrus peel on the expansion characteristics of starch-cellulose extrudates. High and low methoxyl pectin (HMP and LMP) was added to the starch-cellulose mixtures and extruded using a twin-screw extruder. The pasting properties of raw mixtures, extrusion properties, microstructure, and dietary fiber contents of the extrudates were studied. The inclusion of HMP in raw material improved the peak viscosity (629.7 ± 8.1 to 754.7 ± 80.1 mPa s) and maintained the final viscosity compared to the control (starch-cellulose mixture alone), unlike LMP. HMP relatively maintained the extrusion process parameters such as torque, back pressure, and specific mechanical energy as the control. Interestingly, the addition of 7% of HMP had a similar expansion ratio (3.41 ± 0.08 to 2.35 ± 0.06) compared to the control (3.46 ± 0.08 to 2.32 ± 0.09) under the extrusion conditions studied. The total dietary fiber content improved from 12.22 ± 0.01% to 18.26 ± 0.63% (w/w). HMP maintained the expansion characteristic of starch-cellulose extrudates and improved its total dietary fiber content relative to LMP. Adding HMP to the mixtures improved the extensibility of the melt, favoring bubble growth and expansion of the starch-cellulose extrudates. Fourier transform infrared spectroscopy data suggested that there could be intermolecular interactions between starch, cellulose, and pectin, but the nature of these interactions needs further investigation. PRACTICAL APPLICATION: The study provides practical information on the influence of the addition of high and low methoxyl pectin on starch-cellulose extrudates. The results can help the industry to produce snack products that are more nutritious but are still well accepted by the consumers.

Reliability of the running vertical jump test in female team sport athletes.

Injury rates to the lower limb have increased over the past 40 years, coinciding with increases in female sport participation rates. Sport specific tests such as the running vertical jump (RVJ) are utilised for injury risk profiling, however the test-retest reliability is unknown. OBJECTIVES: The aim of this study was to investigate the test-retest reliability of the thorax, pelvis and lower limb joint angular kinematics and kinetics for the RVJ test in female team sport athletes. DESIGN: Three-dimensional motion capture with force plate integration was utilised as participants performed five trials on each limb on three separate days. SETTING: Testing occurred in a biomechanics laboratory. PARTICIPANTS: Thirty-four females (Australian Rules Football = 15, Netball = 12, Soccer = 7) participated in this study. MAIN OUTCOME MEASURES: Intraclass correlation coefficients (ICC), effect sizes and typical errors (TE) of segment and joint angular kinematics and kinetics were calculated. RESULTS: Poor to excellent reliability (ICC = -0.12 - 0.92), small to large effect sizes (0.00-0.90) and TE (0.02-289.24) were observed across segment and joint angular kinematics and kinetics. CONCLUSIONS: The RVJ test is recommended when analysing ground reaction forces and joint angular kinematics in female team sport athletes.

Influences of modified fiber inclusion with varying particle size on corn starch-based extrudate expansion.

The inclusion of cellulose nanocrystals (CNC) and microcrystalline cellulose (MCC) during extrusion processing of corn starch (CS) is presented in this study. Blends were prepared by incorporating CNC and MCC at different concentrations, 1%, 3%, 5%, and 10% w/w in CS. The crystallinity index (CrI) of CNC and MCC was determined using X-ray diffraction, and the chemical functionality of CNC, MCC, and CS was studied using Fourier transform infrared spectroscopy. The pasting properties of the blends were studied using Micro Visco-Amylo-Graph before extrusion. The blends were preconditioned to 18 ± 0.5% (w.b.) moisture and extruded using a twin-screw extruder at 200 and 250 rpm at 140°C. CS-CNC's expansion ratio (ER) values were 2.95 to 3.35 and 2.72 to 3.22 for MCC. CNC's CrI and particle size were significantly lower than MCC, allowing CNC-based extrudates to have ER values similar to the control even at high CNC concentration (≤10% w/w). This study demonstrated that fiber with particle size <100 µm can be added in direct-expanded product formulations at high concentrations without negatively influencing the extrudate texture while offering increased nutritional value. PRACTICAL APPLICATION: This study gives insight into the potential application of cellulose nanocrystals and microcrystalline cellulose in manufacturing direct-expanded extruded products, providing high fiber content without compromising the product quality. This knowledge could also be translated into manufacturing other food products such as breakfast cereals, pasta, and bread.

Energetic Stability and Interfacial Complexity of Ti3C2Tx MXenes Synthesized with HF/HCl and CoF2/HCl as Etching Agents.

MXenes are ultra-thin two-dimensional layered early transition-metal carbides and nitrides with potential applications in various emerging technologies, such as energy storage, water purification, and catalysis. MXenes are synthesized from the parent MAX phases with different etching agents [hydrofluoric acid (HF) or fluoride salts with a strong acid] by selectively removing a more weakly bound crystalline layer of Al or Ga replaced by surface groups (-O, -F, -OH, etc.). Ti3C2Tx MXene synthesized by CoF2/HCl etching has layered heterogeneity due to intercalated Al3+ and Co2+ that act as pillars for interlayer spacings. This study investigates the impacts of etching environments on the compositional, interfacial, structural, and thermodynamic properties of Ti3C2Tx MXenes. Specifically, compared with HF/HCl etching, CoF2/HCl treatment leads to a Ti3C2Tx MXene with a broader distribution of interlayer distances, increased number of intercalated cations, and decreased degree of hydration. Moreover, we determine the enthalpies of formation at 25 °C (ΔHf,25°C) of Ti3C2Tx MXenes etched with CoF2/HCl, ΔHf,25°C = -1891.7 ± 35.7 kJ/mol Ti3C2, and etched with HF/HCl, ΔHf,25°C = -1978.2 ± 35.7 kJ/mol Ti3C2, using high-temperature oxidation drop calorimetry. These energetic data are discussed and compared with experimentally derived and computationally predicted values to elucidate the effects of intercalants and surface groups of MXenes. We find that MXenes with intercalated metal cations have a less exothermic ΔHf,25°C from an increase in the interlayer space and dimension heterogeneity and a decrease in the degree of hydration leading to reduced layer-layer van der Waals interactions and weakened hydration effects applied on the MXene layers. The outcomes of this study further our understanding of MXene's energetic-structural-interfacial property relationships.

Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded extrudates.

Due to their dense characteristics, direct-expanded products fortified with insoluble fiber are generally not well accepted. Understanding the interactions between starch and fiber could help to effectively choose and modify ingredients to produce products containing high amounts of fiber. Therefore, this study aims to explain the interplay between two starches (native and waxy corn) and two pomace types (blueberry and cranberry). Blends up to 100% of pomace were extruded using a co-rotating twin-screw extruder. Raw material and milled extrudates were analyzed for their pasting and hydration properties. Fourier-transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy were conducted to observe molecular changes. The expansion ratio (ER) significantly decreased as pomace was added and ranged from 3.85 for pure waxy corn starch to approximately 1 for blends that contained 80% pomace. Distinctions between the blends were observed. Particularly, at 20% of pomace inclusion, native corn starch with cranberry pomace showed a significantly higher ER. Different behaviors were also detected during the physicochemical analyses. A nonlinear trend between pomace level and water solubility as well as absorption was observed for native corn starch blends, suggesting that molecular interactions between the biopolymers occur. FTIR and NMR results give no evidence for new covalent bonds; hence, the most likely interactions occurring are hydrogen bonds. In addition to the dilution effect of pomace addition, the enhancement or weakening of such interactions between starch molecules by pomace compounds may reduce the ER.

Exploration of physicochemical properties and molecular interactions between cellulose and high-amylose cornstarch during extrusion processing.

Incorporating fiber at high levels (>10%) into direct-expanded products with acceptable texture is challenging. Fundamental explanations for the interaction of starch and fiber and the cause of expansion reduction need further understanding for the effective incorporation of fiber into expanded products. This study aims to explain how cellulose content impacts the physicochemical properties of starch-based extrudates and the long-range and short-range molecular changes of starch. Mixtures of cornstarch (50% amylose) and cellulose were extruded using a co-rotating twin-screw extruder. Thermal and pasting properties of the raw mixtures were evaluated, and the physicochemical properties and microstructure of extrudates were determined. Long-range and short-range molecular changes of starch-cellulose mixtures before and after extrusion were observed by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The expansion ratio of extrudates reduced significantly as the cellulose content increased and had a strong negative correlation with crystallinity. Cell structures of starch-cellulose extrudates had a smaller and more uniform pore size but possessing a more ruptured matrix. FTIR spectra suggested that there was no covalent bonding interaction between starch and fiber after extrusion. Extrusion reduced the overall crystallinity compared to the raw mixtures. XRD showed that the crystallinity of the starch-cellulose extrudates increased as the cellulose content increased, and the XRD peaks representing cellulose remained unchanged. Cellulose could interfere with starch chain reassociation through intermolecular hydrogen bonding during the expansion process. Phase separation of starch and cellulose is likely to occur at high cellulose content, which could be another reason for the reduced expansion.

Ionic Liquid Aggregation Mechanism for Nanoparticle Synthesis.

Nanoparticle synthesis with silylamine reversible ionic liquids (RevILs) has been previously demonstrated to offer unique alternatives to traditional nanoparticle syntheses, allowing for size control and facile deposition onto support surfaces via the switchable nature of the IL. However, the mechanism of nanoparticle synthesis remains uncharacterized. The use of RevILs facilitates the synthesis of size-controlled nanoparticles without the use of additional stabilizing agents (i.e., surfactants, ligands, and polymers) that passivate the nanoparticle surface, which are traditionally required to control the nanoparticle size. Traditional techniques often require harsh activation steps that ultimately impact nanoparticle size and morphology. While RevIL syntheses offer an excellent alternative, as they do not require additional activation steps, the mechanism through which nanoparticles are synthesized in these systems has not been studied previously. Preceding work hypothesized nanoparticles prepared with RevILs are formed via a reverse micelle mechanism, in which nanoparticles are stabilized and templated within the aqueous core of the organized micelle structures. In this work, DOSY-NMR is used to demonstrate that nanoparticles synthesized with 3-aminopropyltriethylsilane RevIL are not formed through a reverse micelle mechanism but rather a switchable aggregation mechanism that affords control over the nanoparticle size via manipulation of the RevIL structure and concentration. Furthermore, it is shown that the addition of water to RevIL systems has detrimental effects on the aggregation behavior of the ionic liquid molecules in solution, causing disassembly of the ion pairs. However, because nanoparticle reduction likely occurs faster than the disassembly of the ion pairs, nanoparticle size is unaffected by the addition of water during nanoparticle reduction.

Subtle changes in hydrogen bond orientation result in glassification of carbon capture solvents.

Water-lean CO2 capture solvents show promise for more efficient and cost-effective CO2 capture, although their long-term behavior in operation has yet to be well studied. New observations of extended structure solvent behavior show that some solvent formulations transform into a glass-like phase upon aging at operating temperatures after contact with CO2. The glassification of a solvent would be detrimental to a carbon-capture process due to plugging of infrastructure, introducing a critical need to decipher the underlying principles of this phenomenon to prevent it from happening. We present the first integrated theoretical and experimental study to characterize the nano-structure of metastable and glassy states of an archetypal single-component alkanolguanidine carbon-capture solvent and assess how minute changes in atomic-level interactions convert the solvent between metastable and glass-like states. Small-angle neutron scattering and neutron diffraction coupled with small- and wide-angle X-ray scattering analysis demonstrate that minute structural changes in solution precipitae reversible aggregation of zwitterionic alkylcarbonate clusters in solution. Our findings indicate that our test system, an alkanolguanidine, exhibits a first-order phase transition, similar to a glass transition, at approximately 40 °C-close to the operating absorption temperature for post-combustion CO2 capture processes. We anticipate that these phenomena are not specific to this system, but are present in other classes of colvents as well. We discuss how molecular-level interactions can have vast implications for solvent-based carbon-capture technologies, concluding that fortunately in this case, glassification of water-lean solvents can be avoided as long as the solvent is run above its glass transition temperature.

Family satisfaction with critical care in the UK: a multicentre cohort study.

OBJECTIVE: To assess family satisfaction with intensive care units (ICUs) in the UK using the Family Satisfaction in the Intensive Care Unit 24-item (FS-ICU-24) questionnaire, and to investigate how characteristics of patients and their family members impact on family satisfaction. DESIGN: Prospective cohort study nested within a national clinical audit database. SETTING: Stratified, random sample of 20 adult general ICUs participating in the Intensive Care National Audit & Research Centre Case Mix Programme. PARTICIPANTS: Family members of patients staying at least 24 hours in ICU were recruited between May 2013 and June 2014. INTERVENTIONS: Consenting family members were sent a postal questionnaire 3 weeks after the patient died or was discharged from ICU. Up to four family members were recruited per patient. MAIN OUTCOME MEASURES: Family satisfaction was measured using the FS-ICU-24 questionnaire. MAIN RESULTS: A total of 12 346 family members of 6380 patients were recruited and 7173 (58%) family members of 4615 patients returned a completed questionnaire. Overall and domain-specific family satisfaction scores were high (mean overall family satisfaction 80, satisfaction with care 83, satisfaction with information 76 and satisfaction with decision-making 73 out of 100) but varied significantly across adult general ICUs studied and by whether the patient survived ICU. For family members of ICU survivors, characteristics of both the family member (age, ethnicity, relationship to patient (next-of-kin and/or lived with patient) and visit frequency) and the patient (acute severity of illness and receipt of invasive mechanical ventilation) were significant determinants of family satisfaction, whereas, for family members of ICU non-survivors, only patient characteristics (age, acute severity of illness and duration of stay) were significant. CONCLUSIONS: Overall family satisfaction in UK adult general ICUs was high but varied significantly. Adjustment for differences in family member/patient characteristics is important to avoid falsely identifying ICUs as statistical outliers. TRIAL REGISTRATION NUMBER: ISRCTN47363549.

Alcohol Clustering Mechanisms in Supercritical Carbon Dioxide Using Pulsed-Field Gradient, Diffusion NMR and Network Analysis: Feedback on Stepwise Self-Association Models.

Co-solvent clustering in complex fluids is fundamental to solution phase processes, influencing speciation, reactivity, and transport. Herein, methanol (MeOH) clustering in supercritical carbon dioxide is explored with pulsed-field gradient, diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR), and molecular dynamics (MD) simulations. Refinements on the application of self-association models to DOSY-NMR experiments on clustering species are presented. Network analysis of MD simulations reveals an elevated stability of cyclic tetrameric clusters across MeOH concentrations, which is consistent with experimental DOSY-NMR molecular cluster distributions calculated with self-association models that include both cooperative cluster assembly and entropic penalties for the formation of large clusters. Simulations also detail the emergence of cluster-assembly and cluster-disassembly reactions that deviate from stepwise monomer addition or removal. This combination of experiment, simulation, and novel analyses facilitates refinement of models that describe co-solvent aggregation with far-reaching impact on the prediction of solution phase properties of complex fluids.

Metabolic fingerprinting unveils quinoa oil as a source of bioactive phytochemicals.

Quinoa is a pseudo-cereal with high phytochemical contents with proven biological and nutritional significance. In recent decades several breeding programmes have introduced new and traditional quinoa varieties to North America and other non-traditional quinoa regions, raising questions regarding variability in their secondary metabolite profiles. In this work, we have fingerprinted 28 quinoa varieties cultivated in Washington State, focussing on the poorly investigated oil fraction. We found variability in both phenolics and carotenoid contents, which is reflected in different antioxidant capacities, as measured by FRAP and DPPH. Fatty acid profiles show significant differences in palmitic acid and long-chain fatty acids. Finally, conspicuous amounts of phytosterols and squalene were found. Through factor analysis, we classified the quinoa varieties into two groups: a first comprising varieties with higher phytochemical and PUFA contents and a second group, with higher linolenic and long-chain fatty acid contents. Both groups may be suitable for potential food applications.

Restricted fluid bolus versus current practice in children with septic shock: the FiSh feasibility study and pilot RCT.

BACKGROUND: There has been no randomised controlled trial (RCT) of fluid bolus therapy in paediatric sepsis in the developed world despite evidence that excess fluid may be associated with harm. OBJECTIVES: To determine the feasibility of the Fluids in Shock (FiSh) trial - a RCT comparing restricted fluid bolus (10 ml/kg) with current practice (20 ml/kg) in children with septic shock in the UK. DESIGN: (1) Qualitative feasibility study exploring parents' views about the pilot RCT. (2) Pilot RCT over a 9-month period, including integrated parental and staff perspectives study. SETTING: (1) Recruitment took place across four NHS hospitals in England and on social media. (2) Recruitment took place across 13 NHS hospitals in England. PARTICIPANTS: (1) Parents of children admitted to a UK hospital with presumed septic shock in the previous 3 years. (2) Children presenting to an emergency department with clinical suspicion of infection and shock after 20 ml/kg of fluid. Exclusion criteria were receipt of > 20 ml/kg of fluid, conditions requiring fluid restriction and the patient not for full active treatment (i.e. palliative care plan in place). Site staff and parents of children in the pilot were recruited to the perspectives study. INTERVENTIONS: (1) None. (2) Children were randomly allocated (1 : 1) to 10- or 20-ml/kg fluid boluses every 15 minutes for 4 hours if in shock. MAIN OUTCOME MEASURES: (1) Acceptability of FiSh trial, proposed consent model and potential outcome measures. (2) Outcomes were based on progression criteria, including recruitment and retention rates, protocol adherence and separation between the groups, and collection and distribution of potential outcome measures. RESULTS: (1) Twenty-one parents were interviewed. All would have consented for the pilot study. (2) Seventy-five children were randomised, 40 to the 10-ml/kg fluid bolus group and 35 to the 20-ml/kg fluid bolus group. Two children were withdrawn. Although the anticipated recruitment rate was achieved, there was variability across the sites. Fifty-nine per cent of children in the 10-ml/kg fluid bolus group and 74% in the 20-ml/kg fluid bolus group required only a single trial bolus before shock resolved. The volume of fluid (in ml/kg) was 35% lower in the first hour and 44% lower over the 4-hour period in the 10-ml/kg fluid bolus group. Fluid boluses were delivered per protocol (volume and timing) for 79% of participants in the 10-ml/kg fluid bolus group and for 55% in the 20-ml/kg fluid bolus group, mainly as a result of delivery not being completed within 15 minutes. There were no deaths. Length of hospital stay, paediatric intensive care unit (PICU) transfers, and days alive and PICU free did not differ significantly between the groups. Two adverse events were reported in each group. A questionnaire was completed by 45 parents, 20 families and seven staff were interviewed and 20 staff participated in focus groups. Although a minority of site staff lacked equipoise in favour of more restricted boluses, all supported the trial. CONCLUSIONS: Even though a successful feasibility and pilot RCT were conducted, participants were not as unwell as expected. A larger trial is not feasible in its current design in the UK. FUTURE WORK: Further observational work is required to determine the epidemiology of severe childhood infection in the UK in the postvaccine era. TRIAL REGISTRATION: Current Controlled Trials ISRCTN15244462. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 51. See the NIHR Journals Library website for further project information.

Switchable Surfactants for the Preparation of Monodisperse, Supported Nanoparticle Catalysts.

Synthesis methods for the preparation of monodisperse, supported nanoparticles remain problematic. Traditional synthesis methods require calcination following nanoparticle deposition to remove bound ligands and expose catalytic active sites. Calcination leads to significant and unpredictable growth of the nanoparticles resulting in polydisperse size populations. This undesired increase in nanoparticle size leads to a decrease in catalytic activity due to a loss of total surface area. In this work, we present the use of silylamines, a class of switchable solvents, for the preparation of monodisperse, supported nanoparticles. Silylamines are switchable molecules that convert between molecular and ionic forms by reaction with CO2. Upon addition of an alkane, the switchable solvent behaves as a switchable surfactant (SwiS). The SwiS is used to template nanoparticles to aid in synthesis and subsequently used to release nanoparticles for deposition onto a support material. The use of SwiS allowed for the preservation of nanoparticle diameter throughout the deposition process. Finally, it is demonstrated that supported gold nanoparticle catalysts prepared using SwiS are up to 300% more active in the hydrogenation of 4-nitrophenol than their traditionally prepared analogues.

Biological synthesis of nanoparticles in biofilms.

The biological synthesis of nanoparticles (NPs) by bacteria and biofilms via extracellular redox reactions has received attention because of the minimization of harmful chemicals, low cost, and ease of culturing and downstream processing. Bioreduction mechanisms vary across bacteria and growth conditions, which leads to various sizes and shapes of biosynthesized NPs. NP synthesis in biofilms offers additional advantages, such as higher biomass concentrations and larger surface areas, which can lead to more efficient and scalable biosynthesis. Although biofilms have been used to produce NPs, the mechanistic details of NP formation are not well understood. In this review, we identify three critical areas of research and development needed to advance our understanding of NP production by biofilms: 1) synthesis, 2) mechanism and 3) stabilization. Advancement in these areas could result in the biosynthesis of NPs that are suitable for practical applications, especially in drug delivery and biocatalysis. Specifically, the current status of methods and mechanisms of nanoparticle synthesis and surface stabilization using planktonic bacteria and biofilms is discussed. We conclude that the use of biofilms to synthesize and stabilize NPs is underappreciated and could provide a new direction in biofilm-based NP production.

Production of gold nanoparticles by electrode-respiring Geobacter sulfurreducens biofilms.

The goal of this work was to synthesize gold nanoparticles (AuNPs) using electrode-respiring Geobacter sulfurreducens biofilms. We found that AuNPs are generated in the extracellular matrix of Geobacter biofilms and have an average particle size of 20nm. The formation of AuNPs was verified using TEM, FTIR and EDX. We also found that the extracellular substances extracted from electrode-respiring G. sulfurreducens biofilms reduce Au3+ to AuNPs. From FTIR spectra, it appears that reduced sugars were involved in the bioreduction and synthesis of AuNPs and that amine groups acted as the major biomolecules involved in binding.

GC-MS Profiling of Triterpenoid Saponins from 28 Quinoa Varieties (Chenopodium quinoa Willd.) Grown in Washington State.

Quinoa (Chenopodium quinoa Willd) contains 2 to 5% saponins in the form of oleanane-type triterpenoid glycosides or sapogenins found in the external layers of the seeds. These saponins confer an undesirable bitter flavor. This study maps the content and profile of glycoside-free sapogenins from 22 quinoa varieties and 6 original breeding lines grown in North America under similar agronomical conditions. Saponins were recovered using a novel extraction protocol and quantified by GC-MS. Oleanolic acid (OA), hederagenin (HD), serjanic acid (SA), and phytolaccagenic acid (PA) were identified by their mass spectra. Total saponin content ranged from 3.81 to 27.1 mg/g among the varieties studied. The most predominant sapogenin was phytolaccagenic acid with 16.72 mg/g followed by hederagenin at 4.22 mg/g representing the ∼70% and 30% of the total sapogenin content. Phytolaccagenic acid and the total sapogenin content had a positive correlation of r2 = 0.88 (p < 0.05). Results showed that none of the varieties we studied can be classified as "sweet". Nine varieties were classified as "low-sapogenin". We recommend six of the varieties be subjected to saponin removal process before consumption. A multivariate analysis was conducted to evaluate and cluster the different genotypes according their sapogenin profile as a way of predicting the possible utility of separate quinoa in food products. The multivariate analysis showed no correlations between origin of seeds and saponin profile and/or content.

Phonotactic constraints: Implications for models of oral reading in Russian.

The present article investigates how phonotactic rules constrain oral reading in the Russian language. The pronunciation of letters in Russian is regular and consistent, but it is subject to substantial phonotactic influence: the position of a phoneme and its phonological context within a word can alter its pronunciation. In Part 1 of the article, we analyze the orthography-to-phonology and phonology-to-phonology (i.e., phonotactic) relationships in Russian monosyllabic words. In Part 2 of the article, we report empirical data from an oral word reading task that show an effect of phonotactic dependencies on skilled reading in Russian: humans are slower when reading words where letter-phoneme correspondences are highly constrained by phonotactic rules compared with those where there are few or no such constraints present. A further question of interest in this article is how computational models of oral reading deal with the phonotactics of the Russian language. To answer this question, in Part 3, we report simulations from the Russian dual-route cascaded model (DRC) and the Russian connectionist dual-process model (CDP++) and assess the performance of the 2 models by testing them against human data.

Reading aloud: the cumulative lexical interference effect.

Picture naming shows a cumulative semantic interference effect: Latency for naming a target picture increases as a function of the number of pictures semantically similar to the target that have previously been named (Howard, Nickels, Coltheart, & Cole-Virtue, Cognition 100:464-482, 2006). Howard and colleagues, and also Oppenheim, Dell, and Schwartz (Cognition 114:227-252, 2010), argued that this occurs because of the joint presence in the picture-naming system of three critical properties: shared activation, priming, and competition. They also discussed the possibility that whenever any cognitive system possesses these three properties, a cumulative similarity-based interference effect from repeated use of that cognitive system will occur. We investigated this possibility by looking for a cumulative lexical interference effect when the task is reading aloud: Will the latency of reading a target word aloud increase as a function of the number of words orthographically/phonologically similar to the target that have previously been read aloud? We found that this was so. This supports the general idea that cumulative similarity-based interference effects will arise whenever any cognitive system that possesses the three key properties of shared activation, priming, and competition is repeatedly used.