Exploring the potential of neutron imaging for life sciences on IMAT.

Neutron imaging has been employed in life sciences in recent years and has proven to be a viable technique for studying internal features without compromising integrity and internal structure of samples in addition to being complementary to other methods such as X-ray or magnetic resonance imaging. Within the last decade, a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demand for neutron imaging applications in various fields spanning from materials engineering to biology. In this paper, we present the first neutron imaging experiments on different biological samples during the scientific commissioning of the IMAT beamline mainly intended to explore the beamline's capabilities and its potential as a noninvasive investigation tool in fields such as agriculture (soil-plants systems), palaeontology and dentistry. LAY DESCRIPTION: Neutrons form a highly penetrating radiation passing through matter without damaging or structurally modifying it, a property that makes them the ideal tool for many kinds of complementary material investigations. Moreover, the strong interaction of neutrons with hydrogen and their ability to distinguish between hydrogen and deuterium with no radiation damage make neutrons a good probe for imaging biological specimens. The recent technological developments of sources and detectors improved the capabilities of neutron imaging instruments and also have facilitated the use of neutron imaging on a much wider scale than before. Neutron imaging is proving its advantages as being complementary to other known methods of investigation such as X-ray imaging or magnetic resonance imaging and it is no surprise that it is not only employed in engineering or archaeology, but also in life sciences. This definitely opens new perspectives for a more interdisciplinary approach in contemporary science. Within the last decade a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demands of researchers from different fields, spanning from materials engineering to biology. The results presented here, acquired from first measurements on different biological samples during the scientific commissioning of IMAT beamline show the instrument capability and its suitability to palaeontology, agriculture (soil-plants systems) or dentistry applications.

Remote preconditioning and major clinical complications following adult cardiovascular surgery: systematic review and meta-analysis.

BACKGROUND: A number of 'proof-of-concept' trials suggest that remote ischaemic preconditioning (RIPC) reduces surrogate markers of end-organ injury in patients undergoing major cardiovascular surgery. To date, few studies have involved hard clinical outcomes as primary end-points. METHODS: Randomised clinical trials of RIPC in major adult cardiovascular surgery were identified by a systematic review of electronic abstract databases, conference proceedings and article reference lists. Clinical end-points were extracted from trial reports. In addition, trial principal investigators provided unpublished clinical outcome data. RESULTS: In total, 23 trials of RIPC in 2200 patients undergoing major adult cardiovascular surgery were identified. RIPC did not have a significant effect on clinical end-points (death, peri-operative myocardial infarction (MI), renal failure, stroke, mesenteric ischaemia, hospital or critical care length of stay). CONCLUSION: Pooled data from pilot trials cannot confirm that RIPC has any significant effect on clinically relevant end-points. Heterogeneity in study inclusion and exclusion criteria and in the type of preconditioning stimulus limits the potential for extrapolation at present. An effort must be made to clarify the optimal preconditioning stimulus. Following this, large-scale trials in a range of patient populations are required to ascertain the role of this simple, cost-effective intervention in routine practice.

NICE thromboprophylaxis guidelines are not associated with increased pericardial effusion after surgery of the proximal thoracic aorta.

INTRODUCTION: In 2010 the National Institute for Health and Clinical Excellence (NICE) released guidelines on venous thromboembolism. Strategy focused on risk assessment, antiembolic stockings, sequential compression devices, subcutaneous high dose enoxaparin (40 mg), early mobilisation and hydration. The 40 mg enoxaparin dose over the previous 20 mg regimen was worrisome, and its effect on pericardial effusion rates and mortality in proximal aortic surgery was investigated. METHODS: Proximal aortic reconstructions performed between December 2008 and April 2011 were identified from prospectively collected data in a tertiary centre database. Retrospective analysis of patient notes was performed. Proximal aortic surgery patients were categorised as low dose (20 mg) enoxaparin and high dose (40 mg) enoxaparin, and compared for confounding variables. In-hospital, early and one-year readmission rates for pericardial effusion were ascertained from echocardiography reports. The primary outcome was total pericardial effusion rate. Secondary outcomes consisted of 30-day and 1-year mortality. RESULTS: A total of 198 patients underwent proximal thoracic aortic surgery. Nine patients were excluded due to early postoperative death (n=5) and missing patient records (n=4). This left 189 cases for analysis. There were 93 patients in the low dose group and 96 in the high dose group. Groups were comparable for age, cardiopulmonary bypass time, aortic cross-clamp time, postoperative warfarin and antiplatelet agents. Pericardial effusion rates up to one year were comparable (low dose 19% vs high dose 21%). Thirty-day mortality was lower in the low dose group (0 vs 3 deaths). There were four deaths up to one year but these were not attributable to increased enoxaparin. CONCLUSIONS: Increased perioperative thromboprophylaxis dosage does not increase pericardial effusion rates or mortality in proximal aortic surgery.

Pericardial neo-aorta to bridge long segment defects after infected aortic reconstructions.

Aortic prosthetic graft infection is a rare, potentially fatal complication. Surgical explantation of the infected native and prosthetic material with sufficient debridement has sometimes been limited by the lack of a suitable conduit to bridge the residual long segment defect. We describe the implantation of a bovine pericardial fashioned neo-aorta to manage this problem.

The safety and efficacy of itraconazole for the treatment of patients with eumycetoma due to Madurella mycetomatis.

This prospective study aimed to determine the safety and efficacy of itraconazole for the treatment of patients with mycetoma due to Madurella mycetomatis. The study consisted of 13 patients with confirmed disease; all were treated with oral itraconazole in a dose of 400mg daily for three months after which the dose was reduced to 200mg daily for nine months. All patients showed good clinical response to 400mg itraconazole daily, but when the dose was reduced to 200mg daily, the clinical response was gradual and slow. Post-treatment surgical exploration showed that, in all patients, the lesions were well localized, encapsulated with thick capsule and they were easily removed surgically. In all these lesions, grains colonies were encountered and they were viable on culture. Post-operative biopsies showed no significant changes in the morphology of the grains. A constant finding was the presence of between 5-7 grains in a single cavity walled by fibrous tissue. The reaction surrounding the grains was a Type I tissue reaction characterized by a neutrophil zone around grains. Patients were followed up post-operatively for variable periods (range 18-36 months) and only one patient had recurrence. Initial pre-operative treatment with itraconazole may be recommended for eumycetoma patients to enhance lesions encapsulation and localization which can facilitate wide local excision to avoid unnecessary massive mutilating surgery and recurrence.

1-[(Bromo-meth-yl)(phen-yl)meth-ylene]-2-(2,4-dinitro-phen-yl)hydrazine.

The title compound, C(14)H(11)BrN(4)O(4), comprises two crystallographically independent mol-ecules (A and B) in the asymmetric unit. In mol-ecule B, intra-molecular bifurcated N-H⋯O and N-H⋯Br hydrogen bonds and in mol-ecule A, an intra-molecular N-H⋯O hydrogen bond generate S(6) ring motifs. The dihedral angle between the phenyl and benzene rings is 5.44 (6) in mol-ecule A and 7.63 (6)° in mol-ecule B. The ortho- and meta-nitro substituents make dihedral angles of 6.67 (15) and 2.26 (15)° to the attached benzene ring in mol-ecule A and 6.37 (17) and 5.81 (16)° in mol-ecule B. The Br atom in mol-ecule B is disordered over two positions with a refined site-occupancy ratio of 0.61 (3):0.39 (3). Inter-esting features of the crystal structure are the short Br⋯N [3.257 (3)-3.294 (4) Å], Br⋯O [3.279 (3)-3.307 (4) Å] and O⋯O [2.9319 (16)-2.9995 (16) Å] contacts, which are shorter than the sum of the van der Waals radii of these atoms. The crystal structure is further stabilized by inter-molecular C-H⋯O and π-π inter-actions [centroid-centroid distances = 3.6643 (8)-3.8514 (8) Å].

Structural and thermal characterizations of silica nanoparticles grafted with pendant maleimide and epoxide groups.

Grafting of free maleimide and epoxide pendant groups onto the surface of approximately 7-nm silica nanoparticles was investigated. Glycidyloxypropyl groups (3-glycidyloxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane) that carried epoxide groups and aminopropyl groups were grafted to the silica surface with the help of condensation reactions. Maleimide groups [1,1(')-(methylenedi-4,1-phenelene) bismaleimide] were introduced to the silica surface via nucleophilic addition reaction with the aminopropyl groups pre-grafted onto the surface. The grafted silica samples were characterized using CHN, FTIR, DSC, TGA-FTIR, and 13C and 29Si CP/MAS NMR spectroscopy. NMR analyses revealed that all the functional groups were covalently bonded to the silica surface and most of the maleimide and epoxide rings remained intact on surface. DSC analysis showed that the epoxide groups were more reactive than the maleimide groups.

4-(Dimethyl-amino)benzaldehyde 4-ethyl-thio-semicarbazone.

The title thio-semicarbazone derivative, C(12)H(18)N(4)S, features intra-molecular N-H⋯N and C-H⋯S hydrogen bonds which generate S(5) ring motifs. The dihedral angle between the benzene ring and the thio-urea unit is 6.30 (6)° indicating planarity in the mol-ecule. Inter-molecular N-H⋯S hydrogen bonds generate dimers with an R(2) (2)(8) ring motif. The methyl group of the N-ethyl residue is disordered and was refined with site occupancies of 0.521 (5) and 0.479 (5).

Thoraco-abdominal aneurysm repair in a Jehovah's Witness: maximising blood conservation.

Thoraco-abdominal aneurysm repair usually necessitates blood or blood product transfusion which is prohibited in Jehovah's Witnesses. We report the blood conservation strategy used during thoraco-abdominal aneurysm repair in a Jehovah's Witness. This included pre-operative recombinant erythropoietin, per-operative acute normovolaemic haemodilution, cell salvage, aprotinin, restricted heparinisation, left atrial-distal bypass and recombinant factor VIIa. Post-operative haemoglobin levels were maintained, but a left haemothorax necessitated re-thoracotomy on post-operative day 4. Following re-thoracotomy, Hb was 12.0 g.dL(-1) and platelet count 49 x 10(9).L(-1). Recombinant erythropoietin was recommenced. At discharge (day 12), Hb was 10.1 g.d(L-1). The patient remains well at one year. A thoroughly, pre-planned multi-disciplinary blood conservation strategy can be used to undertake high-risk procedures.

Adsorption characteristics of malachite green on activated carbon derived from rice husks produced by chemical-thermal process.

Phosphoric acid (H(3)PO(4)) and sodium hydroxide (NaOH) treated rice husks, followed by carbonization in a flowing nitrogen were used to study the adsorption of malachite green (MG) in aqueous solution. The effect of adsorption on contact time, concentration of MG and adsorbent dosage of the samples treated or carbonized at different temperatures were investigated. The results reveal that the optimum carbonization temperature is 500 degrees C in order to obtain adsorption capacity that is comparable to the commercial activated carbon for the husks treated by H(3)PO(4). It is interesting to note that MG adsorbed preferably on carbon-rich than on silica rich-sites. It is found that the behaviour of H(3)PO(4) treated absorbent followed both the Langmuir and Freundlich models while NaOH treated best fitted to only the Langmuir model.

Polyvinyl chloride-based membranes for flow injection analysis of quinine in beverages.

Potentiometric response characteristics were evaluated for quinine selective sensors based on a lipophilic ion-exchanger potassium tetrakis[3,5-bis(trifluoromethylphenyl)]borate (PTFB) immobilized together with plasticizing solvents in polyvinyl chloride membranes. The use of dioctyl phthalate (DOP), 2-nitrophenyl phenyl ether (NPPE), and bis(2-ethylhexyl)adipate (BEHA) plasticizers produced good quality quinine sensors that were sensitive and fast responding, and exhibited near Nernstian responses when used as batch-sensors. These membranes were further tested in a wall-jet flow-through potentiometric flow injection analysis (FIA) detector. Quinine sensors containing BEHA were the most suitable membrane, with no noticeable differences in sensitivity even after 5 h of continuous exposure to solutions. Interference by foreign species such as alkali, alkaline earth metal ions, sugars, and sodium benzoate was minimal in either the batch-mode (log selectivity coefficients <-2.60) or as FIA detector. When the FIA method was used, recoveries averaged 99.70% from mineral water samples spiked with 16.22 and 162.20 ppm quinine. Results for determination of quinine in other drinks such as carbonated (64.88 and 71.37 ppm) and bitter lemon drinks (55.15 ppm) agreed with those of the manufacturer's claimed values of <68, <81, and 51 ppm, respectively. With a sample throughput of 50 samples/h under optimized flow conditions, the method can be routinely used to monitor quinine in such samples.

Postoperative deep vein thrombosis in Sudanese patients.

The incidence of postoperative deep vein thrombosis diagnosed by radioisotope scanning in 100 Sudanese patients aged 40 or over was 12%. This compares with an incidence of nearly 30% in 542 patients reported from British hospitals using the same diagnostic technique. The reason for the difference is obscure and needs further investigation.