Iatrogenic uretero-vaginal fistula

A case is presented of iatrogenic late ureterovaginal fistula treated with ureteral transplantation with a very good result. It was found that this was the method of choice in this type of fistulae, and temporary internal ureteral splinting was worthwhile to use as a prophylaxis of iatrogenic ureteral damage.     

Synthesis and two-photon photolysis of 6-(ortho-nitroveratryl)-caged IP3 in living cells

The synthesis of a photolabile derivative of inositol-1,4,5-trisphosphate (IP3) is described. This new caged second messenger (6-ortho-nitroveratryl)-IP3 (6-NV-IP3) has an extinction coefficient of 5000 M(-1) cm(-1) at 350 nm, and a quantum yield of photolysis of 0.12. Therefore, 6-NV-IP3 is photolyzed with UV light about three times more efficiently than the widely used P(4(5))-1-(2-nitrophenyl)ethyl-caged IP3 (NPE-IP3). 6-NV-IP3 has a two-photon cross-section of about 0.035 GM at 730 nm. This absorbance is sufficiently large for effective two-photon excitation in living cells at modest power levels. Using near-IR light (5 mW, 710 nm, 80 MHz, pulse-width 70 fs), we produced focal bursts of IP3 in HeLa cells, as revealed by laser-scanning confocal imaging of intracellular Ca2+ concentrations. Therefore, 6-NV-IP3 can be used for efficient, subcellular photorelease of IP3, not only in cultured cells but also, potentially, in vivo. It is in the latter situation that two-photon photolysis should reveal its true forte.     

Singlet oxygen evolution from layered transition metal oxide cathode materials and its implications for lithium-ion batteries

For achieving higher energy density lithium-ion batteries, the improvement of cathode active materials is crucial. The most promising cathode materials are nickel-rich layered oxides LiNi_xCo_yMn_zO₂ (NCM) and over lithiated NCM (often called HE-NCM). Unfortunately, the full capacity of NCM cannot be utilized due to its limited cycle-life at high state-of-charge (SOC), while HE-NCM requires high voltages. By operando emission spectroscopy, we show for the first time that highly reactive singlet oxygen is released when charging NCM and HE-NCM to an SOC beyond ≈80%. In addition, on-line mass-spectrometry reveals the evolution of CO and CO₂ once singlet oxygen is detected, providing significant evidence for the reaction between singlet oxygen and electrolyte to be a chemical reaction. It is controlled by the SOC rather than by potential, as would be the case for a purely electrochemical electrolyte oxidation. Singlet oxygen formation therefore imposes a severe challenge to the development of high-energy batteries based on layered oxide cathodes, shifting the focus of research from electrochemically stable 5?V-electrolytes to chemical stability toward singlet oxygen.     

Measuring multi-dimensional, time-dependent mechanical properties of a human tibial fracture using an automated system

This paper presents an element of a long-term research project determining a clinically quantifiable end point for fracture healing in humans. An automated loading and measurement device is presented. It has been developed as a research tool for the assessment of the mechanical properties of a healing human tibial fracture. The device has been specifically designed for use with patients treated with external fixation. The characteristics of the device have been presented together with an assessment of errors. A typical sample of results has been presented to demonstrate the significance of the device; subsequent papers will examine the whole data set in greater depth. The results presented here confirm the non-linear behaviour of callus and reinforce the requirement to measure the load rate when measuring the fracture stiffness. A new material property for the assessment of fracture healing, namely gamma, is examined and preliminary results are shown. Polar plots of stiffness demonstrate that, when measuring fracture stiffness, not only should the load rate be considered, but also the orientation of measurement. The results from this work support the view that the fracture stiffness should be measured in at least two planes. Currently a fracture can be considered healed when the fracture stiffness exceeds 15 N m/deg; this paper questions whether this value is now valid and suggests that it should be re-examined.     

A fracture movement monitoring system to aid in the assessment of fracture healing in humans

This paper presents a new design for a device to monitor the motion of fracture fragments in diaphyseal tibial fractures. The device measures the motion that occurs at the fracture site when loaded by gait or by manipulation. It has undergone rigorous calibration and acceptance trials. The device has been used in ethically approved research clinics held at the North Staffordshire Hospital (40 patients). The paper presents a selection of results obtained using the new device. The results demonstrate several new ways of assessing fracture healing by examining fracture site motion. The following conclusions were drawn: 1. If fracture monitoring devices are to be attached to bone screws, it is essential to minimize bone screw errors. To do this, each patient must have similar bone screw lengths, orientations, alignment and siting. This is only achievable using a peroperative reduction device. 2. If fracture stiffness is to be used as a measure of fracture healing, load rate should be controlled; at the very least strain rate should be controlled. 3. It is imperative that fracture stiffness be measured in more than one plane by a biplanar device so that asymmetry may be accommodated. 4. Fracture stiffness, on its own, is probably not a sufficiently rigorous measure of healing end-point. The quantifiably viscoelastic properties of healing callus should be taken into account.     

A device for improved reduction of tibial fractures treated with external fixation

A widely used method of treatment for unstable tibial shaft fractures is unilateral external fixation. The majority of fixators act as three distinct devices: an intra-operative reduction device, a device to maintain fracture alignment during healing and an aid to healing by allowing movement at the fracture site. Conventional operative techniques require the surgeon to manipulate a number of degrees of freedom at once, making reduction of the fracture difficult, and results in the fixator being out of alignment with the long axis of the bone. An operative method has been developed that separates reduction and fixation. A dedicated device has been designed to improve the per-operative control of fracture fragments during fracture reduction. The device has been used in clinical trials for the reduction of 22 diaphyseal tibial fractures. Compared with previous operative techniques there has been a saving of 53 per cent in fracture reduction time and an overall saving of 10 per cent in operating time. Fracture alignment has been improved compared with reductions achieved with a fixator which potentially improves healing and lowers the rate of malunion. In each case the fixator has been applied in alignment with the bone, improving dynamization and reducing the likelihood of malunion due to fixator cam slippage.     

The effect of replacing sand with aggregate from sanitary ceramic waste on the durability of stucco mortars

Clean Technologies and Environmental Policy - During processing and transport, the ceramic industry generates big amounts of waste. In order to limit the number of landfills and to minimise...