BACKGROUND

The purpose of the present study was to evaluate the effects of surgical timing on the outcome of pediatric lateral condyle fractures (LCF). We hypothesize that performing open reduction and internal fixation (ORIF) for a displaced LCF between 7 and 14 days after the occurrence of injury does not result in significant changes in outcome, as compared with those treated within the first 7 days.

METHODS

A total of 181 pediatric LCFs treated with ORIF, with a mean follow-up of 38 weeks and a mean age of 5 years, were included. All information related to the patient's elbow injury was prospectively collected. We identified 2 specific groups: 133 LCFs that were treated within the first 7 days after injury (group 1), and 48 that were treated between 7 and 14 days after injury (group 2). A satisfactory outcome was one in which there was evidence of healing of the fracture, a range of motion of at least 85% of the normal, contralateral side at the latest follow-up, and no evidence of complications, loss of fixation, infection, or avascular necrosis of the lateral condyle.

RESULTS

Overall, the mean time from injury to surgery was 5 days (range, 0 to 14 d). Initial fracture displacement was slightly larger in group 1 versus group 2, by a mean of 2.6 mm (P=0.004). There were no iatrogenic nerve injuries or vascular complications in either group. There was no difference in the mean surgical time between groups (P=0.004). At the latest follow-up appointment, elbows in both groups had similar range of motion (P=0.5), a low and similar rate of complications, and comparable rates of satisfactory outcomes (88.0% vs. 87.5%; P=0.6).

CONCLUSIONS

Our study suggests that performing an ORIF for a displaced pediatric LCF up to 14 days after the original injury does not adversely affect the outcome of the procedure.

METHODS

Level II-comparative study.

This study explored the fate and adverse effects of 3 main hexabromocyclododecane diastereoisomers (α-, β-, and γ-HBCDDs) in a soil pot system planted with ryegrass (Lolium perenne L.) using a short-term (8 weeks) experiment. At the end of the experiment, soil urease activity in planted spiked soil increased and catalase activity decreased; while there was no obvious change in sucrase and peroxidase activities. HBCDDs mainly accumulated in the root of ryegrass, with root concentration factors (RCF) in the range of 1.46-4.43 and only a small part was transferred to the stem (SCF: 0.198-0.305) and leaf (LCF: 0.042-0.062). The concentration factors varied for different HBCDD diastereoisomers, being in the order of α->> β->> γ-HBCDD for all tissues, indicating preferential accumulation of α-HBCDD in ryegrass tissues. Moreover, the enantiomeric analysis revealed an enrichment of (+)-α-, (-)-β- and (+)-γ-HBCDD enantiomers in ryegrass tissues. β- and γ-HBCDDs (up to 1.90% and 4.11%, respectively) were transformed to aα-HBCDD in ryegrass, while no isomerization product from α-HBCDD was found. Hydroxylated HBCDDs metabolites, such as monoOHHBCDDs and diOHHBCDDs were found in ryegrass tissues for the first time.

A fully quantitative analysis of liquid crystal film (LCF) color patterns, in phantom thermal dosimetry for microwave hyperthermia, is presented. An accurate determination of absorption rate density (ARD) is achieved by color image computer processing. This work is proven to be an improvement upon the semi-quantitative or qualitative descriptions of LCF colors performed essentially by visual analysis of photographs. Temperature-induced chromatic distributions are acquired as R, G, B (red, green, blue) signals by a CCD camera connected to a PC frame grabber board. These data, stored into three 512 x 512 memory buffers, are then converted to H, S, I (hue, saturation, intensity) colorimetric system. Provided a suitable calibration of the LCF, the H quantity can be transformed to temperature using a monotonic relationship. In this way, a temperature accuracy lower than 0.2 degrees C and a spatial resolution less than 1 mm are obtained. A sequence of thermal maps can be acquired and stored on disk at a maximum rate of 1 image/2 s, and then the ARD is calculated at each pixel of the map using the least squares method.

The significance of reciprocal ST-segment depression during acute occlusion of an epicardial coronary artery is still actively debated. "Ischemia at a distance" has been implicated in numerous reports. To determine the prevalence and mechanism of reciprocal changes, we recorded 12-lead electrocardiograms (ECG) during balloon inflation in 66 patients undergoing 79 coronary angioplasty (PTCA) procedures. The 38 men and 28 women had a mean age of 59 +/- 12 years. Twenty nine PTCAs were of the dominant right coronary artery (RCA), 24 were of the proximal left anterior descending artery (LAD), 24 of the left circumflex artery (LCF), and 2 of the diagonal branch of the LAD. Primary ST elevation >> or = 1 mm) occurred in 56 (71%) PTCAs, 49 (88%) of which showed reciprocal >> or = 1 mm) ST depression. Reciprocal changes occurred in 15 of 21, 19 of 20, and 14 of 14 PTCAs of the LAD, RCA, and LCF, respectively (p value not significant [NS]) and were common in patients with collateral vessels supplying the arterial bed distal to the site of balloon occlusion (60%). They were equally prevalent in PTCAs of patients with single-vessel disease and patients with multivessel disease (90% vs 82%, p = NS). We conclude that reciprocal changes occur in the majority regardless of the vessel involved or the extent of coronary artery disease, that they usually represent electric phenomena and not remote ischemia, and that "ischemia at a distance" is not a diagnosis that can be made by ECG.

The purpose of this investigation was to study the low-cycle fatigue (LCF) behavior of a newly developed high-pressure die-cast (HPDC) Al-5.5Mg-2.5Si-0.6Mn-0.2Fe (AlMgSiMnFe) alloy. The effect of heat-treatment in comparison with its as-cast counterpart was also identified. The layered (α-Al + Mg₂Si) eutectic structure plus a small amount of Al₈(Fe,Mn)₂Si phase in the as-cast condition became an in-situ Mg₂Si particulate-reinforced aluminum composite with spherical Mg₂Si particles uniformly distributed in the α-Al matrix after heat treatment. Due to the spheroidization of intermetallic phases including both Mg₂Si and Al₈(Fe,Mn)₂Si, the ductility and hardening capacity increased while the yield stress (YS) and ultimate tensile strength (UTS) decreased. Portevin-Le Chatelier effect (or serrated flow) was observed in both tensile stress-strain curves and initial hysteresis loops during cyclic deformation because of dynamic strain aging caused by strong dislocation-precipitate interactions. The alloy exhibited cyclic hardening in both as-cast and heat-treated conditions when the applied total strain amplitude was above 0.4%, below which cyclic stabilization was sustained. The heat-treated alloy displayed a larger plastic strain amplitude and a lower stress amplitude at a given total strain amplitude, demonstrating a superior fatigue resistance in the LCF regime. A simple equation based on the stress amplitude of the first and mid-life cycles ((Δσ/2)first, (Δσ/2)mid) was proposed to characterize the degree of cyclic hardening/softening (D): D=±(Δσ/2)mid - (Δσ/2)first(Δσ/2)first, where the positive sign "+" represents cyclic hardening and the negative sign "-" reflects cyclic softening.

Keywords: AlMgSiMnFe alloy; cyclic hardening; heat treatment; low-cycle fatigue; serrated flow.

Hybrid laminates consist of layers of different materials, which determine the mechanical properties of the laminate itself. Furthermore, the structure and interfacial properties between the layers play a key role regarding the performance under load and therefore need to be investigated in respect to industrial applicability. In this regard, a hybrid laminate comprised of AA6082 aluminum alloy sheets and glass and carbon fiber-reinforced thermoplastic (polyamide 6) is investigated in this study with a focus on the influence of aluminum surface treatment application on tensile and fatigue behavior. Four different aluminum surface treatments are discussed (adhesion promoter, mechanical blasting, phosphating, and anodizing), which were characterized by Laser Scanning Microscopy. After the thermal consolidation of the hybrid laminate under defined pressure, double notch shear tests and tensile tests were performed and correlated to determine the resulting interfacial strength between the aluminum sheet surface and the fiber-reinforced plastic, and its impact on tensile performance. To investigate the performance of the laminate under fatigue load in LCF and HCF regimes, a short-time procedure was applied consisting of resource-efficient instrumented multiple and constant amplitude tests. Digital image correlation, thermography, and hysteresis measurement methods were utilized to gain information about the aluminum surface treatment influence on fatigue damage initiation and development. The results show that fatigue-induced damage initiation, development, and mechanisms differ significantly depending on the applied aluminum surface treatment. The used measurement technologies proved to be suitable for this application and enabled correlations in between, showing that the hybrid laminates damage state, in particular regarding the interfacial bonding of the layers, can be monitored not just through visual recordings of local strain and temperature development, but also through stress-displacement hysteresis analysis.

Keywords: AA6082; damage mechanisms; digital image correlation; double notch shear test; fatigue behavior; fiber metal laminate; instrumented fatigue testing; surface treatment; thermoplastic.

The present paper aims to analyze the microstructure, microhardness, tensile properties, and low cycle fatigue (LCF) behavior of friction stir welded (FSW) butt joints. The material used in this study was the 5 mm thick 5083 H111 aluminum alloy sheet. Butt joints of AA 5083 H111 were manufactured at different operating parameters of the FSW process. The effect of the welding parameters on microstructure, microhardness, and tensile properties was investigated. Based on microstructure analysis and strength tests, the most favorable parameters of the FSW process were settled on the point of view of weld quality. Then, LCF tests of base material and friction stir welded specimens made of 5083 H111 were carried out for the examined welded samples under selected friction stir welding parameters. The process of low-cycle fatigue of 5083 H111 aluminum alloy was characterized by cyclic hardening for both: base material and FSW joint. It was revealed by a decrease in the width of the hysteresis loop with the simultaneous significant increase in the values of the range of stress. It was determined that fatigue cracks are initiated by cyclic slip deformation due to local stress concentration from the surface in the corner of the samples for the base material and the heat-affected zone for FSW joints. For all tested strain amplitudes, the fatigue crack propagation region is characterized by the presence of fatigue striation with secondary cracks.

Keywords: 5083 aluminum alloy; fracture; friction stir welding; low cycle fatigue.

The quasi-static and low cycle fatigue tests of extruded 7075 Al alloy (Φ200 mm) were investigated in three directions: the extrusion direction (ED), the radial direction (RD), and 45° with ED (45°). Grain morphology analysis, texture measurement, and fatigue fracture characterization were conducted to discuss the relationship between microstructure and mechanical properties. The experimental results showed that the ED specimen had higher ultimate tensile strength (UTS) and low cycle fatigue (LCF) properties, which were mainly attributed to the following three causes. First, the grain boundaries (GBs) had an obvious effect on the crack growth. The number of GBs in the three directions was different due to the shape of the grains elongated along the ED. Second, the sharp <111> texture and the small Schmidt factor along the ED explained the higher ultimate tensile strength (UTS) of the ED specimens. Third, fatigue fracture observation showed that the ED specimen had a narrow fatigue striation spacing, which indicated that the plastic deformation of the ED specimen was the smallest in each cycle. In addition, two fatigue prediction models were established to predict the LCF life of extruded 7075 Al alloy, based on the life response behavior of the three directions under different strains.

Keywords: 7075 Al alloy; anisotropy; fatigue model; low cycle fatigue; texture.

The production of low-cost and high-quality carbon fibers (CFs) from biorenewable lignin precursors has been of worldwide interest for decades. Although numerous works have been reported and the proposed "1.72 GPa/172 GPa" target set by the Department of Energy (DOE) has been closely met in a few studies, most lignin-based CFs (LCFs) have poor strength properties compared to industrial PAN (polyacrylonitrile)-based CFs. The production of LCFs involves several steps, and the final quality of LCFs is governed by both lignin's properties and the manufacturing processes. Therefore, understanding the key factors of producing high quality LCF is of high importance. In this review, we firstly outlined several lignin's properties (e.g., impurities, thermal properties, molecular structure) that may play important role in determining its processability and suitability as carbon fiber precursor. Secondly, conversion strategies include spinning, stabilization and carbonization, and corresponding parameters influencing the final quality of LCF are comprehensively analyzed. Last, additional characterization methods are proposed as a means to facilitate analyzing of lignin and LCF. This review attempts to provide insights towards high quality LCF production from both material and manufacturing aspects.

Keywords: Carbon fiber; Lignin; Strength properties.

Among trace metal pollutants, zinc is the major one in the rivers from the Paris urban area, such as the Orge River, where Zn concentration in the suspended particulate matter (SPM) can reach 2000 mg/kg in the most urbanized areas. In order to better understand Zn cycling in such urban rivers, we have determined Zn speciation in SPM as a function of both the seasonal water flow variations and the urbanization gradient along the Orge River. Using TEM/SEM-EDX and linear combination fitting (LCF) of EXAFS data at the Zn K-edge, we show that Zn mainly occurs as tetrahedrally coordinated Zn(2+) sorbed to ferrihydrite (37-46%), calcite (0-37%), amorphous SiO2 (0-21%), and organic-P (0-30%) and as octahedrally coordinated Zn(2+) in the octahedral layer of phyllosilicates (18-25%). Moreover, the Zn speciation pattern depends on the river flow rate. At low water flow, Zn speciation changes along the urbanization gradient: geogenic forms of Zn inherited from soil erosion decrease relative to Zn bound to organic-phosphates and amorphous SiO2. At high water flow, Zn speciation is dominated by soil-borne forms of Zn regardless the degree of urbanization, indicating that erosion of Zn-bearing minerals dominates the Zn contribution to SPM under such conditions.

Fluorescamine and 2-methoxy-2,4-diphenyl-3(2H)-furanone (MDPF) react with primary amines at alkaline pH to yield highly fluorescent products, claimed to be diaryl-2-hydroxy-pyrrolinones. However, it seems to have been overlooked that these products appear as the pseudobase of coplanar and cationic diarylpyrrolones. Horse blood smears subjected to fluorogenic MDPF and fluorescamine reactions showed eosinophil granules with bright blue-white fluorescence, which required washing at neutral pH and was dependent on the presence of amino groups. The fluorescence of MDPF-butylamine product was abolished at alkaline pH and by bisulphite, suggesting that nucleophilic attacks to the pyrrolone ring (with formation of carbinol (pseudobase) and sulfonate derivatives, respectively), destroy the planarity and conjugation of the whole molecule, thus abolishing the emission at long wavelength. Analysis of the correlation between the largest conjugated fragment (LCF) values and the emission peaks of several fluorophores (fluorescamine- and MDPF-butylamino products, non-rigid fluorochromes) showed the best-fit when the cationic pyrrolones were considered. Although the pseudobases of fluorescamine- and MDPF-amino derivatives are formed at alkaline pH, a full conjugated, coplanar and cationic molecule is suggested to be the true fluorescent product.

The rabbit Semimembranosus proprius (SMp) and Semimembranosus accessorius (SMa) muscles represent good models for studying the transformations of muscle properties during postnatal differentiation. In the adult, these muscles are homogeneous in slow twitch (SMp) and fast twitch (SMa) fibers, respectively. However, they are heterogeneous at birth and express their adult characteristics from two months onwards. During this period we studied the influence of motor innervation on the development of their properties, particularly at the level of acetylcholinesterase (AChE) molecular forms and myosin slow (LCs) and fast (LCf) light chains. The postnatal alteration of SMa and SMp muscles was characterized by the disappearance of the neonatal heterogeneity and the acquisition of the homogeneous fast or slow fiber type pattern. The fibers of these muscles denervated at birth were altered differently: dramatic atrophy of fast twitch fibers whatever the muscles studied, preservation of SMp slow twitch fiber characteristics and fatty degeneration of SMa. At birth, both muscles presented a similar pattern of myosin fast and slow LC. In control muscles, the alteration of fiber populations to homogeneous types led to the disappearance of supernumerary chains from 15 days onwards. In the slow muscle, neonatal denervation prevented LCf disappearance. In the fast muscle, denervation influenced essentially the installation of LCf which was delayed by 15 days. At birth, the polymorphism of AChE was similar in SMp and SMa muscles. One month after denervation, the specific activity of AChE was twice that of the control. Its polymorphism was not much disturbed, while in the adult denervation induced a large increase in AChE specific activity (x 10) and particularly a great alteration in its polymorphism according to the fast or slow muscle fiber types.

Coir is one of the most important natural fibers having significant potentiality in structural biocomposites production. The long coir fiber (LCF) and short fibrous chips (CFC) were extracted from the husk of coconut. The dimensions of the CFC were within 1.0-12.5 mm and the LCF were within 2.0 mm. All the fibers and fibrous chips were treated with 5% NaOH (alkali) before the biocomposite manufacturing. Different percentages (8%, 10%, and 12%) of melamine-urea-formaldehyde (MUF) were used to produce the tri-layered medium density composite panels with 12 mm thickness. The mechanical properties (tensile, flexural, and internal bonding strengths) of coir reinforced multilayered composites has been studied for all the produced biocomposites. The morphological, micro-structural, and bonding mechanisms were investigated by Scanning electron microscope and Fourier-transform infrared spectroscopy analysis. Thermal properties of the biocomposites were studied by thermal conductivity, thermogravimetric analysis, and derivative thermogravimetry characterization. The moisture contents of the final composite panels were also investigated in this study. The main objective of this work is to investigate the influences of MUF on treated coir fiber and fibrous chips reinforced tri-layered biocomposites. Beside, a novel sustainable product is developed through reinforcing the fibrous chip with coir fiber in terms of multilayered biocomposite panels.

Chromium (VI) reduction by organic compounds is one of the major pathways to alleviate the toxicity and mobility of Cr(VI) in the environment. However, oxidative products of organic molecules receive less scientific concerns. In this study, hydroquinone (H₂Q) was used as a representative organic compound to determine the redox reactions with Cr(VI) and the concomitant oxidative products. Spectroscopic analyses showed that Cr(III) hydroxides dominated the precipitates produced during redox reactions of Cr(VI) and H₂Q. For the separated filtrates, the acidification induced the oxidative polymerization of organic molecules, accompanied with the complexation with Cr(III). The aromatic domains dominated the chemical structures of the black and fluffy organic polymers, which was different to the natural humic acids due to the shortage of aliphatic chains. Results of linear combination fitting (LCF) for Cr K-edge X-ray absorption near edge structure (XANES) spectra demonstrated that up to 90.4% of Cr inventory in precipitates derived after the acidification of filtrates was Cr(III) complexed with humic-like polymers, suggesting that Cr(III) possibly acted as a linkage among organic molecules during the polymerization processes of H₂Q. This study demonstrated that Cr(VI) may lead to the polymerization of organic molecules in an acidic solution, and thus, it could raise scientific awareness that the oxidative decomposition of organic molecules may not be the only pathway while interacting with the strong oxidant of Cr(VI).

Redox mapping of solid-phase particles has been used for speciation mapping of near-surface materials or within grains through the use of thin-sections without depth information. Here, a procedure is presented for data collection and processing of depth-dependent redox mapping within solid particles using confocal micro-X-ray fluorescence imaging (CMXRFI). The procedure was applied to a biochar particle that was reacted with Cr(VI)-spiked water. The total Cr distribution was first obtained at an above-edge energy of the K-edge, and showed that Cr was primarily distributed near the surface of the particle. Redox mapping was conducted at 33 representative energies and linear combination fitting (LCF) was performed for the 33 data points from each pixel. The results indicate Cr(III) is the primary species with fractions ranging from 0.6 to 1 and that this fraction is greater in the interior pixels of the particle than at the surface; in contrast, the Cr(VI) fraction is greater at the surface than for interior pixels. The results likely indicate Cr(VI) was first adsorbed and diffused into the biochar, and then reduced to Cr(III). With more Cr(VI) adsorption and the exceedance of the reduction potential of the biochar, remaining Cr(VI) was accumulated on the surface. The redox mapping method was validated by micro-XANES (X-ray absorption near-edge structure) and XPS (X-ray photoelectron spectroscopy) results. This demonstration indicates the developed method combined with CMXRFI can be used to delineate the distribution of different oxidation states of an element within an intact particle or layer.

Control of acidity is critical for cheese quality, as high acidity can be associated with poor flavor and textural attributes. We investigated an alternative method to control cheese acidity, specifically in low-fat (LF) and reduced-fat (RF) milled curd, direct-salted Gouda cheese, which involved altering the initial lactose content of cheesemilk. In traditional Gouda cheese manufacture, a critical technique to control acidity is whey dilution (WD); that is, partial removal of whey and its replacement with water. Direct standardization of the lactose content of milk during the ultrafiltration process could be a simpler and more effective technique to control cheese acidity. This study compared the effect of traditional WD at 2 different levels, 15 and 30% (WD15 and WD30), with the alternative approach of adjustment of the lactose content of milk using low-concentration-factor ultrafiltration (LCF-UF). The composition, texture, functionality, and sensory properties of these LF and RF Gouda cheeses were evaluated. A milled curd, direct-salted cheese manufacturing protocol was used. Milks used for cheesemaking had a lactose-to-casein (L:CN) ratio of approximately 1.8, which is the typical ratio found in milk, whereas milks prepared with lactose standardization (LS) were made from UF concentrated milks with water added during filtration to achieve a L:CN ratio of approximately 1.1. Cheeses made with LS exhibited lower lactose and lactic acid contents than WD30 and WD15, leading to significantly higher pH values in the cheese. Dynamic small-amplitude oscillatory rheology indicated that use of LS led to cheeses with a lower crossover temperature (melting point) than the cheeses made with WD. Cheeses made with LS had lower insoluble Ca contents, likely caused by the addition of water required to achieve the lower L:CN ratio in these milks. Sensory analysis also indicated that LS cheeses had lower acidity and softer texture. These results suggest that standardization of the L:CN ratio of milk could be a useful alternative to WD (or a curd rinse step) to reduce acidity in cheeses. In addition, LS could be used to help soften texture and increase meltability, if desired in lower-fat cheese types.

Cattle-derived biochar (CB), which is derived from industrial pyrolysis of cattle carcasses in harmless treatment plants, is a naturally occurring mineral form of carbonate-bearing hydroxyapatite (CHAP) with a small amount of elemental carbon. CB has 4.02% of carbonate content, which falls under the B-type substitution of CHAP. In this work, the Cd(II) sorption capacity of CB was determined to be 0.82 mmol/g, with 97.6% of the Cd(II) uptake contributing to CHAP and only 2.36% of the Cd(II) uptake contributing to the elemental carbon component. The calculation and linear combination fitting (LCF) of Cd L₃-edge X-ray absorption near-edge structure (XANES) analysis indicated that the contributions of Cd(II) species to CB presented the following order: ion exchange (57.6%-61.0%) > precipitation (24.4%-29.9%) > surface complexation (12.5%-13.4%). The depth dependent X-ray photoelectron spectroscopy (XPS) showed the presence of ion exchange, which is accompanied by intraparticle diffusion. LCF of XANES and Rietveld analysis of X-ray diffraction (XRD) demonstrated that Cd(II) was precipitated in the form of Cd₅H₂(PO₄)₄·4H₂O on the CB surface. Furthermore, the precipitate was directly observed and identified by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). Consequently, we revealed the intricate binding mechanism of Cd(II) to CHAP-rich CB and confirmed the importance of surface precipitation.

Serpentine soils and ultramafic laterites develop over ultramafic bedrock and are important geological materials from environmental, geochemical, and industrial standpoints. They have naturally elevated concentrations of trace metals, such as Ni, Cr, and Co, and also high levels of Fe and Mg. Minerals host these trace metals and influence metal mobility. Ni in particular is an important trace metal in these soils, and the objective of this research was to use microscale (µ) techniques to identify naturally occurring minerals that contain Ni and Ni correlations with other trace metals, such as Fe, Mn, and Cr. Synchrotron based µ-XRF, µ-XRD, and µ-XAS were used. Ni was often located in the octahedral layer of serpentine minerals, such as lizardite, and in other layered phyllosilicate minerals with similar octahedral structure, such as chlorite group minerals including clinochlore and chamosite. Ni was also present in goethite, hematite, magnetite, and ferrihydrite. Goethite was present with lizardite and antigorite on the micrometer scale. Lizardite integrated both Ni and Mn simultaneously in its octahedral layer. Enstatite, pargasite, chamosite, phlogopite, and forsterite incorporated various amounts of Ni and Fe over the micrometer spatial scale. Ni content increased six to seven times within the same 500 µm µ-XRD transect on chamosite and phlogopite. Data are shown down to an 8 µm spatial scale. Ni was not associated with chromite or zincochromite particles. Ni often correlated with Fe and Mn, and generally did not correlate with Cr, Zn, Ca, or K in µ-XRF maps. A split shoulder feature in the µ-XAS data at 8400 eV (3.7 Å-1 in k-space) is highly correlated (94% of averaged LCF results) to Ni located in the octahedral sheet of layered phyllosilicate minerals, such as serpentine and chlorite-group minerals. A comparison of bulk-XAS LCF to averaged µ-XAS LCF results showed good representation of the bulk soil via the µ-XAS technique for two of the three soils. In the locations analyzed by µ-XAS, average Ni speciation was dominated by layered phyllosilicate and serpentine minerals (76%), iron oxides (18%), and manganese oxides (9%). In the locations analyzed by µ-XRD, average Ni speciation was dominated by layered phyllosilicate, serpentine, and ultramafic-related minerals (71%) and iron oxides (17%), illustrating the complementary nature of these two methods.

Disposal of dredged sediments is expensive and poses a major challenge for harbor dredging projects. Therefore beneficial reuse of these sediments as construction material is highly desirable assuming contaminants such as heavy metals are immobilized and organics are mineralized. In this research, the effect of the addition of 2.5% phosphate, followed by thermal treatment at 700 degrees C, was investigated for metal contaminants in dredged sediments. Specifically, Zn speciation was evaluated, using X-ray absorption spectroscopy (XAS), by applying principal component analysis (PCA), target transformation (TT), and linear combination fit (LCF) to identify the main phases and their combination from an array of reference compounds. In dredged sediments, Zn was present as smithsonite (67%) and adsorbed to hydrous manganese oxides (18%) and hydrous iron oxides (15%). Phosphate addition resulted in precipitation of hopeite (22%), while calcination induced formation of spinels, gahnite (44%), and franklinite (34%). Although calcination was previously used to agglomerate phosphate phases by sintering, we found that it formed sparingly soluble Zn phases. Results from the U.S. EPA toxicity characteristic leaching procedure (TCLP) confirmed both phosphate addition and calcination reduced leachability of heavy metals with the combined treatment achieving up to an 89% reduction.

The purpose of this study is to characterize manganese oxidation states and speciation in airborne particulate matter (PM) and describe how these potentially important determinants of PM toxicity vary by location. Ambient PM samples were collected from five counties across the US using a high volume sequential cyclone system that collects PM in dry bulk form segregated into "coarse" and "fine" size fractions. The fine fraction was analyzed for this study. Analyses included total Mn using ICP-MS and characterization of oxidation states and speciation using X-ray absorption spectroscopy (XAS). XAS spectra of all samples and ten standard compounds of Mn were obtained at the National Synchrotron Light Source. XAS data was analyzed using Linear Combination Fitting (LCF). Results of the LCF analysis describe differences in composition between samples. Mn(II) acetate and Mn(II) oxide are present in all samples, while Mn(II) carbonate and Mn(IV) oxide are absent. To the best of our knowledge, this is the first paper to characterize Mn composition of ambient PM and examine differences between urban sites in the US. Differences in oxidation state and composition indicate regional variations in sources and atmospheric chemistry that may help explain differences in health effects identified in epidemiological studies.

Plasma probes are simple and inexpensive diagnostic tools for fast measurements of relevant plasma parameters. While in earlier times being employed mainly in relatively cold laboratory plasmas, plasma probes are now routinely used even in toroidal magnetic fusion experiments, albeit only in the edge region, i.e., the so-called scrape-off layer (SOL), where temperature and density of the plasma are lower. To further avoid overheating and other damages, in medium-size tokamak (MST) probes are inserted only momentarily by probe manipulators, with usually no more than a 0.1 s per insertion during an average MST discharge of a few seconds. However, in such hot and high-density plasmas, their usage is limited due to the strong particle fluxes onto the probes and their casing which can damage the probes by sputtering and heating and by possible chemical reactions between plasma particles and the probe material. In an attempt to make probes more resilient against these detrimental effects, we tested two graphite probe heads (i.e., probe casings with probes inserted) coated with a layer of electrically isolating ultra-nano-crystalline diamond (UNCD) in the edge plasma region of the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, People's Republic of China. The probe heads, equipped with various graphite probe pins, were inserted frequently even into the deep SOL up to a distance of 15 mm inside the last closed flux surface (LCFS) in low- and high-confinement regimes (L-mode and H-mode). Here, we concentrate on results most relevant for the ability to protect the graphite probe casings by UNCD against harmful effects from the plasma. We found that the UNCD coating also prevented almost completely the sputtering of graphite from the probe casings and thereby the subsequent risk of re-deposition on the boron nitride isolations between probe pins and probe casings by a layer of conductive graphite. After numerous insertions into the SOL, first signs of detachment of the UNCD layer were noticed.

Keywords: graphite sputtering; hazardous plasma; hot plasma; plasma; plasma probes; re-deposition; ultra-nano-crystalline diamond coating.

By using metal compounds or oxide/organic acid and enhanced reaction temperatures in the controlled solvothermal oxidation of [Mo3O2(MeCO2)6(H2O)3]2+, more interstitial metal atoms were introduced to produce the largest nanoscale MoIV-polyoxomolybdates, [M2@(MoIV3py3)4Mo18Ox]q- (M = Al, V, Mo). Each [H4V2@(MoIV3py3)4Mo18O84]12- (2a) nanocluster is surrounded by 12 [V3Mo12O42] to build a Lewis catalysis field (LCF) composed of MoIV3[O8Mo4]3 Lewis acid-base cluster pairs in the crystalline 2, accounting for the excellent and stable catalysis performance in the hydrazine reduction of nitroarenes to arylamines in varied solvents. The proposed new concept LCF provides a new way of thinking for designed synthesis and real applications of highly efficient LCF catalysts.

BACKGROUND

Vitamin D may be important for the development and function of the nervous system. Low serum vitamin D levels have been detected in several neurological diseases.

OBJECTIVE

To ascertain the relationship between 25(OH)D serum level and disability in subjects with severe acquired brain injury (sABI).

METHODS

Prospective cross-sectional study Methods: Consecutive subjects with sABI admitted to neuro-rehabilitation were enrolled. A sample of subjects from the neurological ward was considered the control group. Vitamin D serum levels and blood parameters were measured at admission. Disability Rating Scale (DRS), Glasgow Outcome Scale (GOS), and Level of Cognitive Functioning (LCF) were used in assessing disability.

RESULTS

A total of 104 subjects (34 F, 70 M; mean age 53.9 ± 15.2 years) were enrolled: 54 (19 F, 35 M) with sABI and 50 (15 F, 35 M) subjects as control group. Deficient mean serum levels of vitamin D (19.2 ± 9.4 ng/mL) were detected in the subjects with sABI and a significant inverse correlation between vitamin D serum levels and DRS score was detected (p = 0.04).

CONCLUSIONS

Subjects with sABI showed vitamin D deficiency that might correlate to disability severity. The reason is unclear and might represent a secondary phenomenon resulting from the inflammatory process.

A large and important group of acid-base disturbances are the metabolic acidoses. In general, every type of metabolic acidosis can be treated with infusion of base when the underlying cause of the disturbances is removed. In our medical centers, the use of tris and bicarbonate is common. For a long time they were competitive agents and until now it was not possible to decide by available clinical methods which of these substances was more suitable for correction of metabolic acidosis. The intracellular pH of the whole rat (mean lcf-pH) was determined from the distribution of 14C labelled DMO (5,5-dimethyl-2,4-oxazolidinedione) and monitored for 6 h following intravenous application of tris or sodiumbiarbonate in a dose of 10 mmol per kg body mass. Arterial plasma pH and PCO2 were also measured. To determine and compare the effectiveness of the two buffer substances, intra- and extracellular bicarbonate were calculated from the Henderson-Hasselbalch equation. It was found that the buffering following bicarbonate infusion is more effective in both body compartments. Sodiumbicarbonate should be preferred in daily practice.