Tolerability of graded levels of tall oil fatty acids as a nutritional additive for broiler chickens: a 45-day target animal safety study

1. The following study was conducted to evaluate the tolerability of tall oil fatty acid (TOFA) to broiler chickens, at 3 graded levels as a nutritional additive in complete feed.2. 256 one-day-old female and male Cobb 500 broiler chickens were assigned to four dietary treatment groups with TOFA at 0 (control), 1.0, 3.0, or 5.0 g/kg complete feed for 45 days.3. Birds were weighed individually on days 0, 16, 31, and 45, and the feed intake, bird weight gain, and feed conversion ratio were calculated for the respective starter, grower and finisher phases and over the whole study. On day 45, blood samples were drawn from each bird for haematology and blood chemistry measurements. Two birds per pen were subjected to gross pathological examination and sampling of several tissues for histopathology, including weighing the liver.4. The dietary treatments did not affect zootechnical performance parameters or mortality over the whole study period. Bird performance was typical for the breed.5. Haematology, clinical chemistry and histopathology did not reveal any changes associated with dietary TOFA dosing. However, the 5.0 g/kg dose level increased the relative weight of the liver, as a percentage of final body weight, compared to the control group, but there was lack of corresponding histopathology findings.6. In conclusion, the study indicated that oral administration of TOFA for 45 days in feed was well tolerated by the birds at dietary levels of up to 5.0 g/kg.

Establishing the tolerability to broiler chickens and laying hens of nonanoic acid at practical levels of use as a feed flavouring

1. The following experiments were conducted to evaluate the effects of nonanoic acid (NA) in broilers and laying hens, at practical levels as a flavouring in complete feed.2. In the first experiment, 1100, one-day-old Ross 308 chicks, half male and female, were randomly assigned to 50 floor pens containing 22 chicks each. Chicks were fed one of five treatment diets containing either 0 (control), 100, 300, 500 or 1,000 mg NA/kg complete feed for 42 days.3. The NA treatment had no effect on ADFI, but there was a linear relationship with ADG and FCR. No differences were observed in blood parameters or tissue pathology among treatment groups.4. In a second study, 150 Hyline hens aged 24 weeks old were randomly assigned to 50 pens containing three birds each. Laying hens were fed one of five treatment diets containing 0 (control), 100, 300, 500 or 1,000 mg NA/kg complete feed for 56 days.5. Treatment with NA has no effect on live weight, ADFI or egg production in laying hens, and there were no observed changes in tissue pathology.6. The results supported the toleration of NA in broilers or layers at dietary levels of up to 1,000 mg/kg.

Torso body armour coverage defined according to feasibility of haemorrhage control within the prehospital environment: a new paradigm for combat trauma protection

Developments in military personal armour have aimed to achieve a balance between anatomical coverage, protection and mobility. When death is likely to occur within 60 min of injury to anatomical structures without damage control surgery, then these anatomical structures are defined as 'essential'. However, the medical terminology used to describe coverage is challenging to convey in a Systems Requirements Document (SRD) for acquisition of new armour and to ultimately translate to the correct sizing and fitting of personal armour. Many of those with Ministry of Defence responsible for the procurement of personal armour and thereby using SRDs will likely have limited medical knowledge; therefore, the potentially complex medical terminology used to describe the anatomical boundaries must be translated into easily recognisable and measurable external landmarks. We now propose a complementary classification for ballistic protection coverage, termed threshold and objective, based on the feasibility of haemorrhage control within the prehospital environment.

Impact of Obesity in Patients with Candida Bloodstream Infections: A Retrospective Cohort Study

BACKGROUND

Candida species are responsible for 15% of bloodstream infections, leading to prolonged hospitalizations and increased mortality. With the rise in obesity, antifungal dosing is unclear. The purpose of this study was to determine differences in clinical outcomes between obese versus non-obese patients with Candida bloodstream infections.

METHODS

This retrospective cohort included adult patient's first episode of Candida bloodstream infection treated with ≥ 48 h of antifungal therapy between 1 June 2013 and 31 August 2019. Patients were excluded for: dual systemic antifungal therapy, polymicrobial infections, or chronic candidiasis. The primary outcome was infection-related length of stay. Secondary outcomes included: time to candidemia resolution, 30-day readmission rates, and in-hospital mortality.

RESULTS

Eighty patients were included (28 obese; 52 non-obese). Most were male (55%); median age was 54 years. Median BMI and weight were 36.3 kg/m2 and 103 kg versus 20.4 kg/m2 and 61 kg, respectively (p < 0.01). Baseline characteristics were comparable. C. albicans was isolated in 37.5% of cultures and C. glabrata in 30%. Micafungin was utilized empirically in 72.5% of patients; obese patients received definitive micafungin more frequently (57.1% vs. 21.2%; p < 0.01) and were treated longer (13 versus 10 days; p = 0.04). Infection-related length of stay was 19 days in the obese patients and 13 days in the non-obese patients (p = 0.05). Non-obese patients had a shorter duration of candidemia (5 versus 6 days; p = 0.02). In-hospital mortality was numerically higher in obese patients (21.4% versus 13.5%; p = 0.36). There were no differences in 30-day readmissions between groups.

CONCLUSIONS

Worse clinical outcomes were observed for obese versus non-obese patients. Further clinical research is warranted.

Sizing of ballistic arm protection for the VIRTUS body armour and load carriage system

INTRODUCTION

Severe haemorrhage from the arm that is unresponsive to direct pressure necessitates the application of a tourniquet. Detachable arm protection, referred to as brassards, are used by the UK Armed Forces to protect the upper arm from fragmentation threats. However, the coverage they originally provided was based on limited medical evidence. Medical consensus has determined that the dimensions of arm protection should in future be related to how far up the arm a tourniquet can be applied.

METHOD

CT scans of 120 male Armed Forces personnel were analysed to ascertain the vertical distances from acromion process to the point at which a tourniquet can applied, equating to the anterior axillary fold. These values were statistically compared with those derived from the 2007 UK Military anthropometric survey using a paired t-test. Additional distances were added to account for tourniquet width and slippage, with the total value compared with VIRTUS brassard length.

RESULTS

No significant difference (p<0.01) was found in mean acromion to axilla length (114 mm) compared with that found in the anthropometric survey confirming sample validity. The deltoid insertion lay 24 mm below the axillary fold for the 50th percentile value from CT. Essential arm coverage for the 99th percentile male in this study was calculated as 201 mm.

CONCLUSIONS

Based on this research, a single new brassard for the VIRTUS body armour and load carriage system was recommended and manufactured based on the 99th percentile. This is over 30% shorter than the existing VIRTUS brassard, reducing the overall weight burden for the soldier and improving heat dispersion, integration and interoperability. The new brassard has been issued to Armed Forces personnel since October 2018. The reduced mass of ballistic protective material in conjunction with requiring only a single size of brassard has already saved the Ministry of Defence £20 000 in procurement costs.

Minimum depths to essential structures in a UK military population using computed tomography: application to stab-resistant body armour

INTRODUCTION

Edged weapons are a known domestic threat to the police forces of the UK. This threat is mitigated by wearing stab-resistant body armour that is either worn overtly or covertly depending on role. Although the UK military have traditionally focused their body armour design upon ballistic and fragmentation threats, future roles may require protection against an edged weapon threat. Since 2017, UK police body armour requirements for anatomical coverage for both edged weapon and ballistic threats are now based upon the requirements of UK military. This revised coverage may need additional research to determine minimum distances to essential structures.

METHOD

Three entry locations and penetration vectors were chosen using the limited available information in the literature, in combination with a specialist in edged weapons defence. One hundred twenty CT trauma scans of male military service personnel were subsequently analysed to ascertain minimum distances from skin surface to the first structure encountered that is included in essential coverage (heart, aorta, vena cava, liver and spleen) at 3 specific entry points.

RESULTS

Individuals ranged between 18 and 46 years, with a mean body mass index of 24.8. The absolute minimum depth from skin surface to a structure within the auspice of essential coverage was 17 mm to the liver in entry point 3 and 19 mm to the heart in entry point 2.

CONCLUSIONS

Minimum distances to critical structures were significantly larger than those described in previous studies on civilians. This study will be used to supplement existing evidence to support existing UK police requirements for stab-resistant body armour. Using the weapon entry sites and vectors described in this study, overmatching to a behind armour depth of 17 mm would cover all of this population in this study.

Chirality at two-dimensional surfaces: A perspective from small molecule alcohol assembly on Au(111)

The delicate balance between hydrogen bonding and van der Waals interactions determines the stability, structure, and chirality of many molecular and supramolecular aggregates weakly adsorbed on solid surfaces. Yet the inherent complexity of these systems makes their experimental study at the molecular level very challenging. In this quest, small alcohols adsorbed on metal surfaces have become a useful model system to gain fundamental insight into the interplay of such molecule-surface and molecule-molecule interactions. Here, through a combination of scanning tunneling microscopy and density functional theory, we compare and contrast the adsorption and self-assembly of a range of small alcohols from methanol to butanol on Au(111). We find that longer chained alcohols prefer to form zigzag chains held together by extended hydrogen bonded networks between adjacent molecules. When alcohols bind to a metal surface datively via one of the two lone electron pairs of the oxygen atom, they become chiral. Therefore, the chain structures are formed by a hydrogen-bonded network between adjacent molecules with alternating adsorbed chirality. These chain structures accommodate longer alkyl tails through larger unit cells, while the position of the hydroxyl group within the alcohol molecule can produce denser unit cells that maximize intermolecular interactions. Interestingly, when intrinsic chirality is introduced into the molecule as in the case of 2-butanol, the assembly changes completely and square packing structures with chiral pockets are observed. This is rationalized by the fact that the intrinsic chirality of the molecule directs the chirality of the adsorbed hydroxyl group meaning that heterochiral chain structures cannot form. Overall this study provides a general framework for understanding the effect of simple alcohol molecular adstructures on hydrogen bonded aggregates and paves the way for rationalizing 2D chiral supramolecular assembly.

Controlling selectivity in the Ullmann reaction on Cu(111)

Using a surface science approach, the selectivity in the Ullmann cross-coupling of aryl halides on Cu(111) has been understood and controlled. The binding strength of the reactants and repulsion between them dictates which organometallic intermediates form, and hence the product distribution. Cross coupling can be maximized at low reactant concentrations.

Temperature and osmotic stress dependence of the thermodynamics for binding linker histone H10, Its carboxyl domain (H10-C) or globular domain (H10-G) to B-DNA

Linker histones (H1) are the basic proteins in higher eukaryotes that are responsible for the final condensation of chromatin. In contrast to the nucleosome core histone proteins, the role of H1 in compacting DNA is not clearly understood. In this study ITC was used to measure the binding constant, enthalpy change, and binding site size for the interactions of H10, or its C-terminal (H10-C) and globular (H10-G) domains to highly polymerized calf-thymus DNA at temperatures from 288 K to 308 K. Heat capacity changes, ΔCp, for these same H10 binding interactions were estimated from the temperature dependence of the enthalpy changes. The enthalpy changes for binding H10, H10-C, or H10-G to CT-DNA are all endothermic at 298 K, becoming more exothermic as the temperature is increased. The ΔH for binding H10-G to CT-DNA is exothermic at temperatures above approximately 300 K. Osmotic stress experiments indicate that the binding of H10 is accompanied by the release of approximately 35 water molecules. We estimate from our naked DNA titration results that the binding of the H10 to the nucleosome places the H10 protein in close contact with approximately 41 DNA bp. The breakdown is that the H10 carboxyl terminus interacts with 28 bp of linker DNA on one side of the nucleosome, the H10 globular domain binds directly to 7 bp of core DNA, and shields another 6 linker DNA bases, 3 bp on either side of the nucleosome where the linker DNA exits the nucleosome core.

Water-Ice Analogues of Polycyclic Aromatic Hydrocarbons: Water Nanoclusters on Cu(111)

Water has an incredible ability to form a rich variety of structures, with 16 bulk ice phases identified, for example, as well as numerous distinct structures for water at interfaces or under confinement. Many of these structures are built from hexagonal motifs of water molecules, and indeed, for water on metal surfaces, individual hexamers of just six water molecules have been observed. Here, we report the results of low-temperature scanning tunneling microscopy experiments and density functional theory calculations which reveal a host of new structures for water–ice nanoclusters when adsorbed on an atomically flat Cu surface. The H-bonding networks within the nanoclusters resemble the resonance structures of polycyclic aromatic hydrocarbons, and water–ice analogues of inene, naphthalene, phenalene, anthracene, phenanthrene, and triphenylene have been observed. The specific structures identified and the H-bonding patterns within them reveal new insight about water on metals that allows us to refine the so-called “2D ice rules”, which have so far proved useful in understanding water–ice structures at solid surfaces.

The impact of emotion on numerical estimation: A developmental perspective

Recent literature has revealed underestimation effects in numerical judgments when adult participants are presented with emotional stimuli (as opposed to neutral). Whether these numerical biases emerge early in development however, or instead reflect overt, learned responses to emotional stimuli across development are unclear. Moreover, reported links between numerical acuity and mathematics achievement point to the importance of exploring how numerical approximation abilities in childhood may be influenced in real-world affective contexts. In this study, children (aged 6-10 years) and adults were presented with happy and neutral facial stimuli in the context of a numerical bisection task. Results reveal that children, like adults, underestimate number following emotional (i.e., happy) faces (relative to neutral). However, children's, but not adult's, responses were also significantly more precise following emotional stimuli. In a second experiment, adult judgments revealed a similar increase in precision following emotional stimuli when numerical discriminations were more challenging (involving larger sets). Together, results are the first to reveal children, like adults, underestimate number in the context of emotional stimuli and this underestimation bias is accompanied with enhanced response precision.

Determining the dimensions of essential medical coverage required by military body armour plates utilising Computed Tomography

INTRODUCTION

Military body armour is designed to prevent the penetration of ballistic projectiles into the most vulnerable structures within the thorax and abdomen. Currently the OSPREY and VIRTUS body armour systems issued to United Kingdom (UK) Armed Forces personnel are provided with a single size front and rear ceramic plate regardless of the individual's body dimensions. Currently limited information exists to determine whether these plates overprotect some members of the military population, and no method exists to accurately size plates to an individual.

METHOD

Computed Tomography (CT) scans of 120 male Caucasian UK Armed Forces personnel were analysed to measure the dimensions of internal thoraco-abdominal anatomical structures that had been defined as requiring essential medical coverage. The boundaries of these structures were related to three potential anthropometric landmarks on the skin surface and statistical analysis was undertaken to validate the results.

RESULTS

The range of heights of each individual used in this study was comparable to previous anthropometric surveys, confirming that a representative sample had been used. The vertical dimension of essential medical coverage demonstrated good correlation to torso height (suprasternal notch to iliac crest) but not to stature (r(2)=0.53 versus 0.04). Horizontal coverage did not correlate to either measure of height. Surface landmarks utilised in this study were proven to be reliable surrogate markers for the boundaries of the underlying anatomical structures potentially requiring essential protection by a plate.

CONCLUSIONS

Providing a range of plate sizes, particularly multiple heights, should optimise the medical coverage and thus effectiveness of body armour for UK Armed Forces personnel. The results of this work provide evidence that a single width of plate if chosen correctly will provide the essential medical coverage for the entire military population, whilst recognising that it still could overprotect the smallest individuals. With regards to anthropometric measurements; it is recommended, based on this work, that torso height is used instead of stature for sizing body armour. Coverage assessments should now be undertaken for side protection as well as for other non-Caucasian populations and females, with anthropometric surveys utilising the three landmarks recommended in this study.

Ullmann coupling mediated assembly of an electrically driven altitudinal molecular rotor

Surface-bound molecular rotation can occur with the rotational axis either perpendicular (azimuthal) or parallel (altitudinal) to the surface. The majority of molecular rotor studies involve azimuthal rotors, whereas very few altitudinal rotors have been reported. In this work, altitudinal rotors are formed by means of coupling aryl halides through a surface-mediated Ullmann coupling reaction, producing a reaction state-dependent altitudinal molecular rotor/stator. All steps in the reaction on a Cu(111) surface are visualized by low-temperature scanning tunneling microscopy. The intermediate stage of the coupling reaction is a metal-organic complex consisting of two aryl groups attached to a single copper atom with the aryl rings angled away from the surface. This conformation leads to nearly unhindered rotational motion of ethyl groups at the para positions of the aryl rings. Rotational events of the ethyl group are both induced and quantified by electron tunneling current versus time measurements and are only observed for the intermediate structure of the Ullmann coupling reaction, not the starting material or finished product in which the ethyl groups are static. We perform an extensive set of inelastic electron tunneling driven rotation experiments that reveal that torsional motion around the ethyl group is stimulated by tunneling electrons in a one-electron process with an excitation energy threshold of 45 meV. This chemically tunable system offers an ideal platform for examining many fundamental aspects of the dynamics of chemically tunable molecular rotor and motors.

The Biosynthesis of Infrared-Emitting Quantum Dots in Allium Fistulosum

The development of simple routes to emissive solid-state materials is of paramount interest, and in this report we describe the biosynthesis of infrared emitting quantum dots in a living plant via a mutual antagonistic reaction. Exposure of common Allium fistulosum to mercury and tellurium salts under ambient conditions resulted in the expulsion of crystalline, non-passivated HgTe quantum dots that exhibited emissive characteristics in the near-infrared spectral region, a wavelength range that is important in telecommunications and solar energy conversion.

Enhancement of low-energy electron emission in 2D radioactive films

High-energy radiation has been used for decades; however, the role of low-energy electrons created during irradiation has only recently begun to be appreciated. Low-energy electrons are the most important component of radiation damage in biological environments because they have subcellular ranges, interact destructively with chemical bonds, and are the most abundant product of ionizing particles in tissue. However, methods for generating them locally without external stimulation do not exist. Here, we synthesize one-atom-thick films of the radioactive isotope (125)I on gold that are stable under ambient conditions. Scanning tunnelling microscopy, supported by electronic structure simulations, allows us to directly observe nuclear transmutation of individual (125)I atoms into (125)Te, and explain the surprising stability of the 2D film as it underwent radioactive decay. The metal interface geometry induces a 600% amplification of low-energy electron emission (<10 eV; ref. ) compared with atomic (125)I. This enhancement of biologically active low-energy electrons might offer a new direction for highly targeted nanoparticle therapies.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles

INTRODUCTION

Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles.

METHODS

A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy.

RESULTS AND CONCLUSIONS

Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

Structure and energetics of hydrogen-bonded networks of methanol on close packed transition metal surfaces

Methanol is a versatile chemical feedstock, fuel source, and energy storage material. Many reactions involving methanol are catalyzed by transition metal surfaces, on which hydrogen-bonded methanol overlayers form. As with water, the structure of these overlayers is expected to depend on a delicate balance of hydrogen bonding and adsorbate-substrate bonding. In contrast to water, however, relatively little is known about the structures methanol overlayers form and how these vary from one substrate to another. To address this issue, herein we analyze the hydrogen bonded networks that methanol forms as a function of coverage on three catalytically important surfaces, Au(111), Cu(111), and Pt(111), using a combination of scanning tunneling microscopy and density functional theory. We investigate the effect of intermolecular interactions, surface coverage, and adsorption energies on molecular assembly and compare the results to more widely studied water networks on the same surfaces. Two main factors are shown to direct the structure of methanol on the surfaces studied: the surface coverage and the competition between the methanol-methanol and methanol-surface interactions. Additionally, we report a new chiral form of buckled hexamer formed by surface bound methanol that maximizes the interactions between methanol monomers by sacrificing interactions with the surface. These results serve as a direct comparison of interaction strength, assembly, and chirality of methanol networks on Au(111), Cu(111), and Pt(111) which are catalytically relevant for methanol oxidation, steam reforming, and direct methanol fuel cells.

Clinical and post mortem analysis of combat neck injury used to inform a novel coverage of armour tool

INTRODUCTION

There is a requirement in the Ministry of Defence for an objective method of comparing the area of coverage of different body armour designs for future applications. Existing comparisons derived from surface wound mapping are limited in that they can only demonstrate the skin entry wound location. The Coverage of Armour Tool (COAT) is a novel three-dimensional model capable of comparing the coverage provided by body armour designs, but limited information exists as to which anatomical structures require inclusion. The aim of this study was to assess the utility of COAT, in the assessment of neck protection, using clinically relevant injury data.

METHOD

Hospital notes and post mortem records of all UK soldiers injured by an explosive fragment to the neck between 01 Jan 2006 and 31 December 2012 from Iraq and Afghanistan were analysed to determine which anatomical structures were responsible for death or functional disability at one year post injury. Using COAT a comparison of three ballistic neck collar designs was undertaken with reference to the percentage of these anatomical structures left exposed.

RESULTS

13/81 (16%) survivors demonstrated complications at one year, most commonly upper limb weakness from brachial plexus injury or a weak voice from laryngeal trauma. In 14/94 (15%) soldiers the neck wound was believed to have been the sole cause of death, primarily from carotid artery damage, spinal cord transection or rupture of the larynx. COAT objectively demonstrated that despite the larger OSPREY collar having almost double the surface area than the two-piece prototype collar, the percentage area of vulnerable cervical structures left exposed only reduced from 16.3% to 14.4%.

DISCUSSION

COAT demonstrated its ability to objectively quantify the potential effectiveness of different body armour designs in providing coverage of vulnerable anatomical structures from different shot line orientations. To improve its utility, it is recommended that COAT be further developed to enable weapon and tissue specific information to be modelled, and that clinically significant injuries to other body regions are also incorporated.

Impact of branching on the supramolecular assembly of thioethers on Au(111)

Alkanethiolate monolayers are one of the most comprehensively studied self-assembled systems due to their ease of preparation, their ability to be functionalized, and the opportunity to control their thickness perpendicular to the surface. However, these systems suffer from degradation due to oxidation and defects caused by surface etching and adsorbate rotational boundaries. Thioethers offer a potential alternative to thiols that overcome some of these issues and allow dimensional control of self-assembly parallel to the surface. Thioethers have found uses in surface modification of nanoparticles, and chiral thioethers tethered to catalytically active surfaces have been shown to enable enantioselective hydrogenation. However, the effect of structural, chemical, and chiral modifications of the alkyl chains of thioethers on their self-assembly has remained largely unstudied. To elucidate how molecular structure, particularly alkyl branching and chirality, affects molecular self-assembly, we compare four related thioethers, including two pairs of structural isomers. The self-assembly of structural isomers N-butyl methyl sulfide and tert-butyl methyl sulfide was studied with high resolution scanning tunneling microscopy (STM); our results indicate that both molecules form highly ordered arrays despite the bulky tert-butyl group. We also investigated the effect of intrinsic chirality in the alkyl tails on the adsorption and self-assembly of butyl sec-butyl sulfide (BSBS) with STM and density functional theory and contrast our results to its structural isomer, dibutyl sulfide. Calculations provide the relative stability of the four stereoisomers of BSBS and STM imaging reveals two prominent monomer forms. Interestingly, the racemic mixture of BSBS is the only thioether we have examined to date that does not form highly ordered arrays; we postulate that this is due to weak enantiospecific intermolecular interactions that lead to the formation of energetically similar but structurally different assemblies. Furthermore, we studied all of the molecules in their monomeric molecular rotor form, and the surface-adsorbed chirality of the three asymmetric thioethers is distinguishable in STM images.

Real-time imaging and elemental mapping of AgAu nanoparticle transformations

We report the controlled alloying, oxidation, and subsequent reduction of individual AgAu nanoparticles in the scanning transmission electron microscope (STEM). Through sequential application of electron beam induced oxidation and in situ heating and quenching, we demonstrate the transformation of Ag-Au core-shell nanoparticles into: AgAu alloyed, Au-Ag core-shell, hollow Au-Ag2O core-shell, and Au-Ag2O yolk-shell nanoparticles. We are able to directly image these morphological transformations in real-time at atomic resolution and perform energy dispersive X-ray (EDX) spectrum imaging to map changing elemental distributions with sub-nanometre resolution. By combining aberration corrected STEM imaging and high efficiency EDX spectroscopy we are able to quantify not only the growth and coalescence of Kirkendall voids during oxidation but also the compositional changes occurring during this reaction. This is the first time that it has been possible to track the changing distribution of elements in an individual nanoparticle undergoing oxidation driven shell growth and hollowing.

Novel method for comparing coverage by future methods of ballistic facial protection

The wearing of eye protection by United Kingdom soldiers in Afghanistan has reduced the morbidity caused by explosive fragments. However, the remaining face remains uncovered because there is a lack of evidence to substantiate the procurement of methods to protect it. Using a new computerised tool we entered details of the entry sites of surface wounds caused by explosive fragments in all UK soldiers who were injured in the face between 1 January 2010 and 31 December 2011. We compared clinical and predicted immediate and long term outcomes (as defined by the Abbreviated Injury Score (AIS) and the Functional Capacity Index (pFCI), respectively). We also used the tool to predict how additional protection in the form of a visor and mandible guard would affect outcomes. A soldier wearing eye protection was 9 times (1.03/0.12) less likely to sustain an eye injury than one without. However, 38% of soldiers in this series were not wearing eye protection at the time of injury. There was no significant difference between the AIS and pFCI scores predicted by the tool and those found clinically. There is limited evidence to support the use of a mandible guard; its greatest asset is better protection of the nose, but a visor would be expected to reduce long-term morbidity more than eye protection alone, and we recommend future trials to assess its acceptability to users. We think that use of this novel tool can help in the selection of future methods of ballistic facial protection.

Hydrogen Dissociation, Spillover, and Desorption from Cu-Supported Co Nanoparticles

Co-Cu nanoparticles have recently been explored for Fischer-Tropsch synthesis (FTS) as a way to combine the long chain selectivity of Co with Cu's activity for alcohol formation in order to synthesize oxygenated transportation fuels. Depending on particle size, hydrogen dissociation can be a rate-determining step in cobalt-catalyzed FTS. To understand the fundamentals of uptake and release of hydrogen from the Co/Cu bimetallic system, we prepared well-defined Co nanoparticles on Cu(111). We demonstrate that hydrogen spills over from dissociation sites on the Co nanoparticles to the Cu(111) surface via the Co-Cu interface and that desorption of H occurs at a temperature that is lower than from Co or Cu alone, which we attribute to the Co-Cu interface sites. From this data, we have constructed an energy landscape for the facile dissociation, spillover, and desorption of hydrogen on the Co-Cu bimetallic system.

Atomic-scale insight into the formation, mobility and reaction of Ullmann coupling intermediates

The Ullmann reaction of bromobenzene, the simplest coupling reagent, to form biphenyl on a Cu surface proceeds via a highly mobile organometallic intermediate in which two phenyl groups extract and bind a single surface Cu atom.

Using computerised surface wound mapping to compare the potential medical effectiveness of Enhanced Protection Under Body Armour Combat Shirt collar designs

INTRODUCTION

Protecting the neck from explosively propelled fragments has traditionally been achieved through a collar attached to the ballistic vest. An Enhanced Protection Under Body Armour Combat Shirt (EP-UBACS) collar has been identified as an additional method of providing neck protection but limited evidence as to its potential medical effectiveness exists to justify its procurement.

METHOD

Entry wound locations and resultant medical outcomes were determined using Abbreviated Injury Scale (AIS) for all fragmentation neck wounds sustained by UK soldiers between 01 January 2010 and 31 December 2011. Data were prospectively entered into a novel computerised tool base and comparisons made between three EP-UBACS neck collar designs in terms of predicted reduction in AIS scores.

RESULTS

All collars reduced AIS scores, with the greatest reduction provided by designs incorporating increased standoff from the neck and an additional semi-circle of ballistic material underneath the collar at the front and back.

DISCUSSION

This technique confirms that reinforcing the neck collar of an EP-UBACS would be expected to reduce injury severity from neck wounds. However, without knowledge of entry wound locations for injuries to other body areas as well as the use of AIS scores without clinical or pathological verification its further use in the future may be limited. The ability to overlay any armour design onto a standardised human was potentially the most useful part of this tool and we would recommend developing this technique using underlying anatomical structures and not just the skin surface.

Exploring the energetics of histone H1.1 and H1.4 duplex DNA interactions

H1.1 and H1.4 bind tightly to both short DNA oligomers and to CT-DNA (Ka≈1×10(7)). Binding is accompanied by an unfavorable enthalpy change (∆H≈+22 kcal/mol) and a favorable entropy change (-T∆S≈-30 kcal/mol). The Tm for the H1.4/CT-DNA complex is increased by 9 °C over the Tm for the free DNA. H1.4 titrations of the DNA oligomers yield stoichiometries (H1/DNA) of 0.64, 0.96, 1.29, and 2.04 for 24, 36, 48, and 72-bp DNA oligomers. The stoichiometries are consistent with a binding site size of 37±1 bp. CT-DNA titration data are consistent with binding site sizes of 32 bp for H1.1 and 36 bp for H1.4. The heat capacity changes, ΔCp, for formation of the H1.1 and H1.4/CT-DNA complexes are -160 cal mol(-1) K(-1) and -192 cal mol(-1)K(-1) respectively. The large negative ΔCp values indicate the loss of water from the protein DNA interface in the complex.

Calorimetric studies of the interactions of linker histone H1(0) and its carboxyl (H1(0)-C) and globular (H1(0)-G) domains with calf-thymus DNA

Histone H1 is a chromatin protein found in most eukaryotes. ITC and CD have been used to study the binding of H1(0) and its C-terminal, H1(0)-C, and globular, H1(0)-G, domains to a highly polymerized DNA. ITC results indicate that H1(0) and H1(0)-C bind tightly to DNA (Ka≈1×10(7)), with an unfavorable ΔH (ΔH≈+22kcal/mol) and a favorable ΔS (-TΔS≈-30kcal/mol). Binding H1(0)-G to DNA at 25°C is calorimetrically silent. A multiple independent site model fits the ITC data, with the anomaly in the data near saturation attributed to rearrangement of bound H1, maximizing the number of binding sites. CD experiments indicate that H1(0)/DNA and H1(0)-C/DNA complexes form with little change in protein structure but with some DNA restructuring. Salt dependent ITC experiments indicate that the electrostatic contribution to binding H1(0) or H1(0)-C is small ranging from 6% to 17% of the total ΔG.

Molecular-scale perspective of water-catalyzed methanol dehydrogenation to formaldehyde

Methanol steam reforming is a promising reaction for on-demand hydrogen production. Copper catalysts have excellent activity and selectivity for methanol conversion to hydrogen and carbon dioxide. This product balance is dictated by the formation and weak binding of formaldehyde, the key reaction intermediate. It is widely accepted that oxygen adatoms or oxidized copper are required to activate methanol. However, we show herein by studying a well-defined metallic copper surface that water alone is capable of catalyzing the conversion of methanol to formaldehyde. Our results indicate that six or more water molecules act in concert to deprotonate methanol to methoxy. Isolated palladium atoms in the copper surface further promote this reaction. This work reveals an unexpected role of water, which is typically considered a bystander in this key chemical transformation.

Controlling a spillover pathway with the molecular cork effect

Spillover of reactants from one active site to another is important in heterogeneous catalysis and has recently been shown to enhance hydrogen storage in a variety of materials. The spillover of hydrogen is notoriously hard to detect or control. We report herein that the hydrogen spillover pathway on a Pd/Cu alloy can be controlled by reversible adsorption of a spectator molecule. Pd atoms in the Cu surface serve as hydrogen dissociation sites from which H atoms can spillover onto surrounding Cu regions. Selective adsorption of CO at these atomic Pd sites is shown to either prevent the uptake of hydrogen on, or inhibit its desorption from, the surface. In this way, the hydrogen coverage on the whole surface can be controlled by molecular adsorption at a minority site, which we term a 'molecular cork' effect. We show that the molecular cork effect is present during a surface catalysed hydrogenation reaction and illustrate how it can be used as a method for controlling uptake and release of hydrogen in a model storage system.

Visualization of compression and spillover in a coadsorbed system: syngas on cobalt nanoparticles

Competitive adsorption and lateral pressure between surface-bound intermediates are important effects that dictate chemical reactivity. Lateral, or two-dimensional, pressure is known to promote reactivity by lowering energetic barriers and increasing conversion to products. We examined the coadsorption of CO and H2, the two reactants in the industrially important Fischer-Tropsch synthesis, on Co nanoparticles to investigate the effect of two-dimensional pressure. Using scanning tunneling microscopy, we directly visualized the coadsorption of H and CO on Co, and we found that the two adsorbates remain in segregated phases. CO adsorbs on the Co nanoparticles via spillover from the Cu(111) support, and when deposited onto preadsorbed adlayers of H, CO exerts two-dimensional pressure on H, compressing it into a higher-density, energetically less-preferred structure. By depositing excess CO, we found that H on the Co surface is forced to spill over onto the Cu(111) support. Thus, spillover of H from Co onto Cu, where it would not normally reside due to the high activation barrier, is preferred over desorption. We corroborated the mechanism of this spillover-induced displacement by calculating the relevant energetics using density functional theory, which show that the displacement of H from Co is compensated for by the formation of strong CO-Co bonds. These results may have significant ramifications for Fischer-Tropsch synthesis kinetics on Co, as the segregation of CO and H, as well as the displacement of H by CO, limits the interface between the two molecules.

Quantum tunneling enabled self-assembly of hydrogen atoms on Cu(111)

Atomic and molecular self-assembly are key phenomena that underpin many important technologies. Typically, thermally enabled diffusion allows a system to sample many areas of configurational space, and ordered assemblies evolve that optimize interactions between species. Herein we describe a system in which the diffusion is quantum tunneling in nature and report the self-assembly of H atoms on a Cu(111) surface into complex arrays based on local clustering followed by larger scale islanding of these clusters. By scanning tunneling microscope tip-induced scrambling of H atom assemblies, we are able to watch the atomic scale details of H atom self-assembly in real time. The ordered arrangements we observe are complex and very different from those formed by H on other metals that occur in much simpler geometries. We contrast the diffusion and assembly of H with D, which has a much slower tunneling rate and is not able to form the large islands observed with H over equivalent time scales. Using density functional theory, we examine the interaction of H atoms on Cu(111) by calculating the differential binding energy as a function of H coverage. At the temperature of the experiments (5 K), H(D) diffusion by quantum tunneling dominates. The quantum-tunneling-enabled H and D diffusion is studied using a semiclassically corrected transition state theory coupled with density functional theory. This system constitutes the first example of quantum-tunneling-enabled self-assembly, while simultaneously demonstrating the complex ordering of H on Cu(111), a catalytically relevant surface.

Binding of netropsin to several DNA constructs: evidence for at least two different 1:1 complexes formed from an -AATT-containing ds-DNA construct and a single minor groove binding ligand

Isothermal titration calorimetry, ITC, has been used to determine the thermodynamics (DeltaG, DeltaH, and -TDeltaS) for binding netropsin to a number of DNA constructs. The DNA constructs included: six different 20-22mer hairpin forming sequences and an 8-mer DNA forming a duplex dimer. All DNA constructs had a single -AT-rich netropsin binding with one of the following sequences, (A(2)T(2))(2), (ATAT)(2), or (AAAA/TTTT). Binding energetics are less dependent on site sequence than on changes in the neighboring single stranded DNA (hairpin loop size and tail length). All of the 1:1 complexes exhibit an enthalpy change that is dependent on the fractional saturation of the binding site. Later binding ligands interact with a significantly more favorable enthalpy change (partial differential DeltaH(1-2) from 2 to 6 kcal/mol) and a significantly less favorable entropy change (partial differential (-TDeltaS(1-2))) from -4 to -9 kcal/mol). The ITC data could only be fit within expected experimental error by use of a thermodynamic model that includes two independent binding processes with a combined stoichiometry of 1 mol of ligand per 1 mol of oligonucleotide. Based on the biophysical evidence reported here, including theoretical calculations for the energetics of "trapping" or structuring of a single water molecule and molecular docking computations, it is proposed that there are two modes by which flexible ligands can bind in the minor groove of duplex DNA. The higher affinity binding mode is for netropsin to lay along the floor of the minor groove in a bent conformation and exclude all water from the groove. The slightly weaker binding mode is for the netropsin molecule to have a slightly more linear conformation and for the required curvature to be the result of a water molecule that bridges between the floor of the minor groove and two of the amidino nitrogens located at one end of the bound netropsin molecule.

Van't Hoff and calorimetric enthalpies from isothermal titration calorimetry: are there significant discrepancies?

The enthalpy of a reaction is most often determined through one of two means; it can be determined directly using calorimetry or indirectly by measuring the temperature dependence of the equilibrium constant (i.e., the van't Hoff method). Recently, discrepancies have been noted between the enthalpy measured by calorimetry, and the enthalpy determined by the van't Hoff method,. This has been suggested to indicate that the binding reaction is more complex than the simple one-to-one binding model used to describe the data. To better understand possible discrepancies between and, we have undertaken both experimental studies using isothermal titration calorimetry to measure the binding energetics of Ba(2+) binding 18-crown-6 ether and 2'-CMP binding RNase A, along with a simulation of a system involving a molecule in conformational equilibrium coupled with binding. We find that when experimental setup and analysis are correctly performed, no statistically significant discrepancies between and exist even for the linked system.

Corporate compliance programs: risk management for the future

The Department of Justice has estimated that the government loses $100 billion annually in health care fraud. Consequently, the government's health care fraud enforcement activities with respect to all health care providers and suppliers continue to grow. Last year alone, the government collected more than $8 billion in settlements, fines, and penalties involving health care fraud. Recent settlements with the government have begun to include corporate compliance programs that require continued government oversight of the health care organization as an essential part of the settlement. The first section of this article describes the legal significance of health care companies' having corporate compliance programs. The second section provides a sample list of topics that should be included in any corporate compliance program. Finally, we describe various issues related to the creation and implementation of corporate compliance programs.

The determination of nicotine and cotinine by ion pair reversed-phase chromatography

An ion chromatographic method is described for the determination of nicotine and cotinine in aqueous solutions. This method is based on a type of reversed-phase chromatography involving ion pair formation of protonated nicotine, cotinine, pyridine, and pyridine derivatives. Detection is accomplished by measuring the UV absorption at 262 nm. Detection limits for nicotine and cotinine are 8 ng/mL and 2 ng/mL, respectively. Analyses of environmental samples and spiked environmental samples by both this ion chromatographic method and a previously reported gas chromatographic method have been used to demonstrate the accuracy and precision of this technique. The results of the analyses of both sets of samples by the two methods are in excellent agreement with a linear correlation coefficient of 0.97.

Kinetics of drug decomposition by heat conduction calorimetry

The application of heat conduction calorimetry to the determination of decomposition mechanisms and rates for drugs is shown to be a rapid and generally useful method. The application of the method to determine the nature of the decomposition reaction, sources of systematic errors in the method, the equations relating the calorimetric signal to the kinetics of the reaction, and some examples of results are presented and discussed.

Clinical and laboratory evaluation of visible light-cured denture base resins and their application to orthodontics

A series of investigations is being conducted to examine the applicability of visible light-cured resins to orthodontics. The experimental vehicle is the Hawley retainer, which is made from autopolymerized (AP), heat-cured (HC), thermoplastic Biocryl 2 (BC), and Traid visible light-cured (VLC) resins. In all physical property testing, it was found that VLC resins met or exceeded required values as established by ADA Specification No. 12 for denture base polymers. In vitro bacterial adherence studies showed that more organisms adhered to heat-cured specimens than to the other specimens. In vivo studies using split-palate Hawley retainers demonstrated slightly less bacterial adherence to BC than to the other resins. Scanning electron microscopy (SEM) observations have shown the BC surface to be the smoothest, although surface chemistry also seems important. None of the materials being tested appears to cause any significant change in the subjacent subgingival bacterial flora. There was no adverse tissue reaction under any of the materials when observed clinically. Manipulation characteristics and time of fabrication appear to be dependent on the depth of the palate and the skill of the operator.

Subependymal giant-cell astrocytoma in children. An unusual discrepancy between histological and clinical features

The authors describe five cases of subependymal giant-cell astrocytoma in children in which many clinical, histological, immunohistochemical, and ultrastructural features typical of this tumor were present. However, prominent focal necrosis and mitoses, features usually associated with high-grade tumors, were seen in all cases. Despite the presence of necrosis and mitoses, clinical follow-up studies have revealed a lack of aggressive tumor behavior after surgery alone. The discrepancy between the histological and clinical features in these cases is emphasized so that excessive treatment of a basically low-grade tumor may be avoided. Mast cells were seen in all five cases, often in large numbers.

A new visible light-cured resin system applied to removable prosthodontics

Preliminary studies of VLC resins have produced promising results; however, additional research is necessary to completely define qualities of this material. Biologic testing of VLC (Triad) resins indicated that they are nontoxic and biocompatible. They have a wide range of uses in all subdisciplines of prosthodontics. Advantages such as accuracy of fit, superior strength, complete polymerization without residual compounds, ease of fabrication and manipulation, patient acceptance, ability to bond with other denture base resins, and low bacterial adherence make this material an important addition to the choices available to dentists. As with many new materials, there are initial problems or hurdles that must be overcome before there is widespread use. Initial formulations of material had insufficient flexural strength and tended to fracture when flexed over uncut sites on a stone cast. This problem has been reduced by Dentsply International, Inc. with the introduction of the new improved formulation. The original VLC bonding agent did not provide sufficient bond strength with acrylic resin denture base materials, but this also has been improved with development of a new VLC bonding agent. The problem of microporosity and small voids produced when adapting VLC resin sheets against a stone cast may be overcome with pressure or vacuum adaptation techniques. A promising application of VLC resin material is in direct intraoral procedures such as relining of dentures. Physical and chemical properties are superior to autopolymerizing methacrylates. Preliminary studies have shown successful patient acceptance to this clinical procedure. It is of particular advantage to the patient not to be without dentures for the period of at least 1 day necessary for a laboratory-processed relining. Immediate light-curing is time-saving and convenient compared to indirect (heat-cured) relining. Until recently, most direct intraoral applications of autopolymerizing acrylic resin reliner material were considered temporary or expedient to a permanent procedure. The patient and dentist may now have another treatment choice. The release of residual methyl methacrylate, among other shortcomings of AP materials, is not a concern when using the VLC reliner material. Some patients may notice a nonobjectionable taste to the uncured material; however, they can be reassured that the taste will be only temporary until the material is completely polymerized in the curing unit. The flow of the material can be regulated by selection of appropriate viscosity, warming and cooling measures, and partial intraoral polymerization with hand-held curing lights.(ABSTRACT TRUNCATED AT 400 WORDS)

Post-haemorrhagic hydrocephalus in the preterm infant

This prospective study documents the incidence, clinical features and risk factors for post-haemorrhagic hydrocephalus (PHH) as well as the short-term outcome after serial CSF taps. Serial real-time ultrasound scans were performed on 220 infants: on all admissions less than or equal to 1250 g and on an additional 130 infants with birthweights greater than 1250 g with risk factors for intraventricular haemorrhage (IVH). Based on percentile charts of postnatal increase in ventricular size and head circumference growth rate, PHH was defined as ventricular dilatation greater than 95th centile associated with either a head circumference growth greater than 95th centile or with clinical features of raised intracranial pressure (ICP). Forty-eight (22%) infants were found to have IVH of whom 14 had intracerebral extension of IVH. Sixteen (40%) of 40 infants who survived the acute episode of IVH developed PHH. PHH occurred more commonly in those who survived severe birth asphyxia and/or intracerebral extension of IVH. Fifteen infants who developed clinical features of raised ICP were treated with serial CSF taps. This procedure was effective in a staged treatment for PHH in relieving clinical symptoms and deferring ventriculo-peritoneal (VP) shunting. Morbidity associated with serial CSF taps and VP shunting is minimal. A high red cell count and protein concentration in the CSF at diagnosis of PHH identified all five infants who subsequently required VP shunting.

Histone H1: ultracentrifugation studies of the effects of ionic strength and denaturants on the solution conformation

The conformation of histone H1 has been examined under native and denaturing conditions in the absence of DNA or chromatin. Sedimentation coefficients were determined for Histone H1 in 0.1 M KCl and in 6 M guanidine hydrochloride solutions at pH 7.4. The influence of ionic strength on the conformation of histone H1 has been determined by measurement of the sedimentation coefficient in tetramethylammonium chloride solutions of up to 2.5 M and extrapolated to infinite ionic strength. Results from these experiments suggest that the native conformation of histone H1 is very asymmetric in shape. The molecule is best described as a prolate ellipsoid with axes of 312 A (2a) and 16 A (2b) in low ionic strength media and also as a prolate ellipsoid with axes of 202 A (2a) and 20 A (2b) at high ionic strength or when associated with polyanions, e.g., DNA. Denaturation of histone H1 by guanidine hydrochloride was found to be completely reversible. In 6 M guanidine hydrochloride, the H1 molecule collapses to a sphere but the original extended conformation of the protein is readily restored on dialysis. This suggests rigid conformational requirements for the H1 molecule as incorporated into chromatin. The shape and dimensions for the H1 molecule at high ionic strength are not sufficiently conclusive to locate H1 in the chromatin structure. It is proposed, however, that viable models for chromatin architecture must be consistent with the histone H1 solution dimensions obtained here.