Flow-through Gas Phase Photocatalysis Using TiO2 Nanotubes on Wirelessly Anodized 3D-Printed TiNb Meshes

In this work, for the first time 3D Ti-Nb meshes of different composition, i.e., Ti, Ti-1Nb, Ti-5Nb, and Ti-10 Nb, were produced by direct ink writing. This additive manufacturing method allows tuning of the mesh composition by simple blending of pure Ti and Nb powders. The 3D meshes are extremely robust with a high compressive strength, giving potential use in photocatalytic flow-through systems. After successful wireless anodization of the 3D meshes toward Nb-doped TiO₂ nanotube (TNT) layers using bipolar electrochemistry, they were employed for the first time for photocatalytic degradation of acetaldehyde in a flow-through reactor built based on ISO standards. Nb-doped TNT layers with low concentrations of Nb show superior photocatalytic performance compared with nondoped TNT layers due to the lower amount of recombination surface centers. High concentrations of Nb lead to an increased number of recombination centers within the TNT layers and reduce the photocatalytic degradation rates.

Photoanodes based on TiO2and α-Fe2O3for solar water splitting – superior role of 1D nanoarchitectures and of combined heterostructures

Solar driven photoelectrochemical water splitting represents a promising approach for a sustainable and environmentally friendly production of renewable energy vectors and fuel sources, such as H₂.

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.

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.

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.

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.

Randomized prospective comparison of postoperative pain control and respiratory complications following midline or transverse laparotomy for aortic surgery

Background

Transverse abdominal incisions are thought to be less painful and followed by fewer pulmonary complications than midline incisions, but reports remain controversial. This study compared midline and transverse incisions for elective transabdominal aortic aneurysm repair with respect to postoperative pain, respiratory function and pulmonary complications.

Methods

Sixty patients were randomized to midline laparotomy and transverse incisions, and evaluated before and after operation for 7 days at regular intervals. Analgesia was provided via a thoracic epidural and pain scores were recorded by means of a visual analogue scale. Respiratory function (peak expiratory flow rate, forced expiratory volume in 1 s and forced vital capacity) and pulmonary complications were monitored as well as patient characteristics, operating time, blood loss, operative exposure, and length of stay on the intensive care unit (ITU) and in hospital.

Results

The two groups included a similar number of patients (n = 30 per group) and basic characteristics such as age and preoperative risk factors. Linear analogue pain scores were significantly lower in the transverse group of patients (P < 0·001). There was no significant difference between the two groups with regard to postoperative ventilatory function and respiratory complications as well as analgesic requirements, operating time, blood loss, and length of ITU and hospital stay.

Conclusion

The direction of incision does not seem to influence the incidence of respiratory complications. However, a transverse incision in combination with a high epidural analgesia seems to offer better postoperative pain control.

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.