Photoelectrochemical degradation of selected organic substances on Fe2O3 photoanodes: a comparison with TiO2.

The photoelectrochemical degradation of selected aromatic substances, acid orange 7 (AO7), salicylic acid (SA), benzoic acid (BA), and 4-chlorophenol (4-CP) was studied on hematite (α-Fe2O3) and compared with titanium dioxide (TiO2), both deposited as thin films on conducting substrates (FTO/glass). Batch type reactors were used under backside and front side illumination. Electrical bias was applied on the semiconducting electrodes, such that only valence band processes leading to oxidative pathways were followed. The initial Faradaic efficiency, f0, of degradation processes was determined from the UV-Vis absorbance decrease of the starting materials. f0 for 1 mM AO7 degradation in 0.01 M sulphuric acid was found to be 7.5%. When the pH of the solution was neutral (pH 7.2) or alkaline (pH 13), f0 decreased to 1.7%. For 1 mM SA, f0 was 6.2% on hematite photoanodes and 6.1% on titanium dioxide. For 1 mM benzoic acid and 4-chlorophenol, f0 was an order of magnitude lower, but only on hematite. This is ascribed to the lack of OH· radical formation on hematite, which seems to be essential for the photooxidation of these compounds.

Quality improvement framework for major amputation: are we getting it right?

INTRODUCTION: The quality improvement framework for major amputation was developed with the aim of improving outcomes and reducing the perioperartive mortality to less than 5% by 2015. The aim of the study was to assess our compliance with the framework guidelines and look for the reasons for non-compliance. METHOD: All major amputations performed between 2008 and 2010 were included. The following data were collected: presence of infection ± tissue loss, status of arterial supply, revascularisation attempts, time to surgery, type of amputation, morbidity and mortality. RESULTS: A total of 81 patients were included (42 BKAs, 39 AKAs). Ninety percentage had formal preoperative arterial investigations and 84% had an attempted revascularisation procedure. Patients who were transferred late from non-vascular units (n = 12) had a 30-day mortality of 50% whereas patients who presented directly to our unit had a 30-day mortality of 7.2%. The number of amputations has decreased over the last 3 years from 34 to 21 per year, coinciding with the doubling of crural revascularisation procedures performed (from 60 to 120 per year). Ten patients underwent a revision from BKA to AKA because of an inadequate profunda femoris artery (PFA), whereas all those with a healed BKA stump either had a good PFA or a named crural vessel. CONCLUSION: The overall number of amputations is decreasing from year to year. By doubling our crural revascularisation procedures we are saving more limbs. Thirty-day mortality is higher than expected, particularly in patients who present late. Expeditious referral may potentially improve the mortality rate among this group of patients.

Evidence for a genetic role in varicose veins and chronic venous insufficiency.

There is a strong body of circumstantial evidence which implicates genetics in the aetiology and pathology of varicose veins and venous ulcer disease. The aim of this review is to consider the current knowledge of the genetic associations and the ways in which new genetic technologies may be applied to advancing our understanding of the cause and progression of these venous diseases. A number of publications have used a candidate gene approach to identify genes implicated in venous disease. Although these studies have opened up important new insights, there has been a general failure to replicate results in an independent cohort of patients. With our limited knowledge of the biological pathways involved in the pathogenesis of venous disease we are not in a strong position to formulate truly erudite a priori candidate gene hypothesis-directed studies. A genome-wide association study should therefore be considered to help further our understanding of the genetic basis of venous disease. Due to the large sample sizes required for discovery and validation, using the new generations of molecular technologies, it will be necessary to form collaborating groups in order to successfully advance the field of venous disease genetics.

Notes on the photo-induced characteristics of transition metal-doped and undoped titanium dioxide thin films.

This study reports the preparation of thin nanoparticulate films of titanium dioxide and its modified version doped with a transition metal. The behavior of prepared films was described by means of their photocatalytic and photo-induced electrochemical properties. The TiO(2) and M/TiO(2) (M=Ag, Zr, Fe) thin films were produced via a standard sol-gel method using titanium n-butoxide, acetylacetone, and transition metal acetylacetonates as precursors. Prepared films were analyzed by a series of techniques involving XRD, Raman spectroscopy, SEM, AFM, and XPS. Their photocatalytic activity was monitored with the aid of decomposition of the model compound Rhodamine B in water. All films were then tested for their photo-induced electrochemical properties based on evaluation of polarization curves (photocurrents). The highest reaction rate constant (0.0101min(-1)), which was even higher than that for pure TiO(2), was obtained for the Ag/TiO(2) sample. The highest quantum yield of the charge collection was determined for the undoped TiO(2) film.

Should vascular surgeons be trained in endovascular techniques? An observational study.

INTRODUCTION: The aim of this study was to determine if there is a satisfactory cover for interventional radiology and whether vascular surgeons have received sufficient training in endovascular techniques. MATERIALS AND METHODS: This was an observational study based on questionnaires sent to radiology and vascular trainers and vascular trainees in England. A total of 50 NHS trusts were chosen randomly to take part in the study and 320 questionnaires were sent out with an overall consultant response rate of 57%. RESULTS: Of vascular consultants in the study group, 53% have had experience in endovascular procedures. Overall, 87% felt that there were not enough radiologists to fulfil the demand and 64% would like further training in endovascular procedures. In addition, 69% would like to be involved in a vascular rota without the general component. Similarly, 81% of radiologists felt that the demand was not being met, as emergency interventional radiology cover was not available on most nights in 65% of the trusts. Of responders, 72% would not object to training of vascular trainees in interventional work and 43% would be happy to be involved in training. Some 33% would accept a vascular trainee for 1 year. CONCLUSIONS: Integrated fellowship in vascular surgery and interventional radiology has been implemented and tested in a number of centres in the US. This approach could be implemented in some of the larger vascular units in the UK.

Outcome of patients on renal replacement therapy after colorectal surgery.

PURPOSE: Patients on renal replacement therapy are reported to have a high complication rate after abdominal surgery, the result of uremia and immunosuppression. A review of this group of patients undergoing colorectal surgery was undertaken. METHODS: Seventy-three separate colorectal operations were performed for 44 patients. Thirty-eight patients were on dialysis and 35 had a renal transplant. Data (coexisting disease, preoperative blood results, operative details, complications, and colorectal POSSUM score) were completed for each surgical event. RESULTS: Forty-two elective and 31 emergency procedures were performed. Infective complications were common (overall 60 percent). There were two anastomotic leaks in the elective group, but five leaks from seven emergency anastomoses. Stomas were frequently raised. Ninety percent of patients who survived and had a defunctioning stoma underwent a successful reversal. The overall major complication rate after elective and emergency surgery was 19 and 81 percent, respectively, and mortality was 5 and 26 percent, respectively. CONCLUSIONS: Renal patients have a high rate of complications after colorectal surgery, and emergency surgery has a significant risk of anastomotic leak. Primary anastomosis should be avoided in all patients undergoing emergency intestinal resections. Subsequent surgery to restore intestinal continuity is possible in 90 percent of patients with far fewer complications.

Pancreas and cystic fibrosis: the implications of increased survival in cystic fibrosis.

Pancreatitis affects 0.5% people with cystic fibrosis (CF) in the UK and 0.01% of the normal population. Why do some with CF get pancreatitis and some not? And does pancreatitis in neonates result in pancreatic failure with no further inflammation or risk of pancreatic cancer? Review of the literature would suggest that 85% of those with CF have pancreatic destruction as children with minimal risk of further inflammatory or neoplastic changes. Those with a functioning pancreas are at risk of developing pancreatitis. There are several case series of pancreatic cancer reported in CF patients, but overall the risk is unknown. As patients with CF and pancreatic sufficiency are living longer, further studies to assess the risk of developing pancreatic cancer in this subgroup should be considered.

Pancreatic cancer--is an aggressive approach justified?

INTRODUCTION: Surgery is the only curative treatment for carcinoma of the pancreas. Resection rates can be low (4.5%), figures of 30% have also been suggested as possible. The approach undertaken in this unit is to consider all patients as potentially resectable unless otherwise proven. PATIENTS & METHODS: 140 patients were studied over 6-year period; 113 underwent palliative treatment (48% distant metastases, 40% local spread, 11% high operative risk); 14 had a triple bypass (14/113 = 12%), 99 were managed conservatively, 43 received palliative chemotherapy. 23/140 (16%) underwent Whipple's procedure (n = 23; 12 females, 11 males; mean age, 60 years); 4/23 had chronic pancreatitis. Distal pancreatectomy was undertaken in 4 patients. RESULTS: Median survival time for patients undergoing a triple bypass was 5 months (range, 0.1-20 months), 3 months for patients treated conservatively (range, 0.1-30 months) and 5 months for patients undergoing palliative chemotherapy (range, 1-30 months). 30-day mortality for Whipple's procedure was 4% (1/23) with median survival rate for patients with carcinoma of 13 months (range, 5-66 months); 31 months for patients with clear resection margins and negative nodes (n = 5). CONCLUSION: This policy allows a resection rate of 19% with increased median survival rate for patients with cancer by 8 months more than those who where not resected. Aggressive staging and pancreatic biopsies allow patients to be entered into chemotherapy trials with improvement in survival and potential future benefits.

Homogeneous (Fe(III)) and heterogeneous (TiO2) photocatalytic systems for pollutant removal from the aquatic compartment: comparison and complementarity.

Kinetics of the oxidative photodegradation of monuron (3-(4-chlorophenyl)-1-1-dimethylurea) in both homogeneous solution of Fe(ClO4)3 and heterogeneous suspension of TiO2, were investigated and compared. In the homogeneous system (Fe(II)), the speciation of Fe(III) aquacomplexes was shown to play an essential role in the rate of photodegradation. For high concentrations of TiO2 (> 500 mg L(-1)), the photodegradation rate was similar to the reaction rate obtained with a freshly prepared solution of Fe(II) (3 x 10(-4) mol L(-1)). In the combined system (TiO2 + Fe(III)), a synergy effect accelerating the monuron photodegradation was observed. Actually, in the presence of Fe(III) (in concentration compatible with a safe environment), a similar reaction rate for monuron photodegradation was obtained with a TiO2 concentration lower by a factor of 20.

Gluteal compartment syndrome following posterior cruciate ligament repair.

Compartment syndrome is a rare but important complication which may occur following injury or surgery to the lower limb. We present a case of contralateral gluteal compartment syndrome following arthroscopic posterior cruciate ligament repair. In order to gain a greater understanding of this complication, we undertook a limited study to investigate the effect of patient position on gluteal compartment pressures. Three volunteers were positioned in such a way as to recreate the intra-operative position of the patient described. Gluteal compartment pressures were calculated by placing weighing scales under each buttock and measuring the surface area over which the weight was distributed.Mean pressures exerted on the gluteal compartment of the non-operated leg were significantly higher (mean=44 mmHg) than those of the operated leg (mean=24 mmHg). The difference was significant with P<0.001. This limited study has shown that care should be taken when positioning patients on an operating table to reduce the risk of compartment syndrome. Factors that should be taken into account include mean diastolic pressure, length of operation and the surface area in contact with the operating table.