Porphyrin functionalized bismuth ferrite for enhanced solar light photocatalysis

In this work, multiferroic bismuth ferrite (BFO) was functionalized with meso-tetraphenylporphine-4,4',4'',4'''-tetracarboxylic acid (TCPP). This new hybrid organic-inorganic material shows an enhanced photocatalytic activity for the degradation of organic dyes as it combines the properties of BFO which is an efficient visible light photocatalyst with peculiar porphyrin absorption in visible light. The anchoring of TCPP to the OH-terminations of the BFO surface through its carboxylic tethering groups was demonstrated using X-ray photoelectron spectroscopy and FT-IR spectroscopy. The photocatalytic activity of the material was also demonstrated through the photocatalytic degradation of Methylene Blue (MB) and Rhodamine-B (Rhd-B) in water under simulated solar light illumination. The TCPP molecules anchored to BFO slightly decrease (∼0.06 eV) the bandgap energy of the system and act as new catalytic centres, thus improving its photocatalytic activity. A photodegradation mechanism was also proposed. This new material is reusable and stable, as it maintains an unmodified photo-activity after several MB discoloration runs.

Characterization of soft tissue tumours with ultrasound, shear wave elastography and MRI

OBJECTIVE

To predict accurately whether a soft tissue mass was benign or malignant and to characterize its type using ultrasound, shear wave elastography and MRI. We hypothesized that with the addition of shear wave elastography, it would be possible to determine a threshold velocity value to classify a lesion as benign or malignant.

MATERIALS AND METHODS

A total of 151 consecutive, consenting adult patients were prospectively recruited to this study in a tertiary referral musculoskeletal oncology centre. All lesions were assessed with ultrasound, including B mode, Doppler and shear wave elastography measurements. One hundred thirty-eight patients also underwent MRI of the lesion. A histological diagnosis was obtained for all lesions.

RESULTS

Malignant lesions were larger than benign lesions and had a greater Doppler activity. There was no useful threshold shear wave velocity to differentiate between benign and malignant lesions. Longitudinal and transverse shear wave velocities were strongly positively correlated with each other. An inverse correlation was shown with lesion size and depth, regardless of whether it was benign or malignant. A logistic regression model combining the ultrasound and MRI characteristics did not confidently classify a lesion as benign or malignant and was inferior to expert opinion.

CONCLUSION

The strongest predictors of malignancy are large lesion size and high vascularity. The combination of all ultrasound characteristics (including shear wave elastography) and MRI features does not confidently classify a lesion as benign or malignant, and histological diagnosis remains the gold standard.

Prognostic indicators of outcome for patients with skeletal metastases from carcinoma of the prostate

AIMS

The purpose of this study was to identify prognostic indicators of outcome at presentation to the orthopaedic surgeon, in patients with metastatic prostate cancer. Our aim was to use this information in a pragmatic, clinic-based approach so that surgical decision making could be optimized to benefit the patient in their remaining lifetime.

PATIENTS AND METHODS

A cohort analysis was undertaken of all patients with metastatic disease of the prostate who presented to a regional orthopaedic centre in the United Kingdom between 2003 and 2016. Biochemical data were collected in addition to disease and demographic data. These included: prostate-specific antigen (PSA) at orthopaedic presentation; haemoglobin (Hb); platelets (plt); alkaline phosphatase (ALP); albumin (Alb); and corrected calcium (CaC). Statistical analysis included Kaplan-Meier survival analysis, and a Cox proportional hazards model was fitted to the data.

RESULTS

From the departmental database, 137 episodes were identified in 136 patients with a median age at presentation of 72 years (interquartile range (IQR) 66 to 78). Most patients had stage IV disease (n = 98, 72%), and most did not undergo surgical intervention. At one-year follow-up, 50% of patients had died. Biomarkers found to be independently associated with poor survival were: low Hb, low Alb, relatively low PSA (< 30 mmol/l), and a raised ALP. Patients who needed surgical intervention had a poorer survival rate than patients who were managed nonoperatively.

CONCLUSION

The study findings are important for orthopaedic clinical practice in the management of patients with metastatic prostate cancer. The interpretation of routine blood tests can help to predict survival in patients who present with orthopaedic manifestations of prostate cancer. A lower PSA is not necessarily a good prognostic sign. We believe that simple blood testing should be carried out routinely when assessing a patient, guiding potential surgical management and palliative care in the future.

The validity of the Mirels score for predicting impending pathological fractures of the lower limb

Aims

The aim of this study was to validate the Mirels score in predicting pathological fractures in metastatic disease of the lower limb.

Patients and Methods

A total of 62 patients with confirmed metastatic disease met the inclusion criteria. Of the 62 patients, 32 were female and 30 were male. The mean age of patients was 65 years (35 to 89). The primary malignancy originated from the breast in 27 (44%) patients, prostate in 15 (24%) patients, kidney in seven (11%), and lung in four (6%) of patients. One patient (2%) had metastatic carcinoma from the lacrimal gland, two patients (3%) had multiple myeloma, one patient (2%) had lymphoma of bone, and five patients (8%) had metastatic carcinoma of unknown primary. Plain radiographs at the time of initial presentation were scored using Mirels system by the four authors. The radiographic components of the score (anatomical site, size, and radiographic appearance) were scored two weeks apart. Inter- and intraobserver reliability were calculated with Fleiss' kappa test. Bland-Altman plots were created to compare the variances of the individual components of the score and the total Mirels score.

Results

Kappa values for the interobserver variability of the components of the Mirels score were k = 0.554 (95% CI 0.483 to 0.626) for site, k = 0.342 (95% CI 0.285 to 0.400) for size, k = 0.443 (95% CI 0.387 to 0.499) for radiographic appearance, and k = 0.294 (95% CI 0.258 to 0.331)for the total score. Kappa values for the intra-observer reliability were k = 0.608 (95% CI 0.506 to 0.710) for site, k = 0.579 (95% CI 0.487 to 0.670) for size, k = 0.614 (95% CI 0.522 to 0.703) for radiographic appearance, and k = 0.323 (95% CI 0.266 to 0.379) for total score.

Conclusion

Our study showed fair to moderate agreement between authors when using the Mirels score, and moderate to substantial agreement when authors rescored radiographs. The Mirels score is subjective and lacks reproducibility in predicting the risk of pathological fracture. Cite this article: Bone Joint J 2018;100-B:1100-5.

Hemiarthroplasty proximal femoral endoprostheses following tumour reconstruction: is acetabular replacement necessary?

AIMS

Dislocation rates are reportedly lower in patients requiring proximal femoral hemiarthroplasty than for patients undergoing hip arthroplasty for neoplasia. Without acetabular replacement, pain due to acetabular wear necessitating revision surgery has been described. We aimed to determine whether wear of the native acetabulum following hemiarthroplasty necessitates revision surgery with secondary replacement of the acetabulum after proximal femoral replacement (PFR) for tumour reconstruction.

PATIENTS AND METHODS

We reviewed 100 consecutive PFRs performed between January 2003 and January 2013 without acetabular resurfacing. The procedure was undertaken in 74 patients with metastases, for a primary bone tumour in 20 and for myeloma in six. There were 48 male and 52 female patients, with a mean age of 61.4 years (19 to 85) and median follow-up of two years (interquartile range (IQR) 0.5 to 3.7 years). In total, 52 patients presented with a pathological fracture and six presented with failed fixation of a previously instrumented pathological fracture.

RESULTS

All patients underwent reconstruction with either a unipolar (n = 64) or bipolar (n = 36) articulation. There were no dislocations and no acetabular resurfacings. Articular wear was graded using the criteria of Baker et al from 0 to 3, where by 0 is normal; grade 1 represents a narrowing of articular cartilage and no bone erosion; grade 2 represents acetabular bone erosion and early migration; and grade 3 represents protrusio acetabuli. Of the 49 patients with radiological follow-up greater than one year, six demonstrated grade 1 acetabular wear and two demonstrated grade 2 acetabular wear. The remainder demonstrated no radiographic evidence of wear. Median medial migration was 0.3 mm (IQR -0.2 to 0.7) and superior migration was 0.3 mm (IQR -0.2 to 0.6). No relationship between unipolar versus bipolar articulations and wear was evident.

CONCLUSION

Hemiarthroplasty PFRs for tumour reconstruction eliminate joint instability and, in the short to medium term, do not lead to native acetabular wear necessitating later acetabular resurfacing. Cite this article: Bone Joint J 2018;100B:101-8.

The impact and efficacy of surveillance in patients with sarcoma of the extremities

OBJECTIVES

In this cross sectional study, the impact and the efficacy of a surveillance programme for sarcomas of the extremities was analysed.

METHODS

All patients who had treatment with curative intent for a high-grade sarcoma and were diagnosed before 2014 were included and followed for a minimum of two years.

RESULTS

Of the 909 patients who had a review appointment in 2014, 131 were under review for a high-grade sarcoma of the extremities following treatment with curative intent. Of these patients, three patients died of disease, two patients died of other causes, 12 are alive, with disease, and 114 have no evidence of disease. The surveillance programme accounts for 14% of all review appointments.Four of five patients (80%) who developed local recurrence identified the recurrence themselves. Chest radiographs are adequate in identifying metastatic disease and 11 (73%) of metastases were diagnosed during a routine follow up visit. However, the chance of cure is small and only two patients were referred for a metastatectomy. Of these only one survived for more than two years.The mean time for developing metastatic disease and local recurrence was 2.0 and 3.9 years respectively. Once identified, the mean time to death was 2.1 years for patients with metastatic disease.

CONCLUSIONS

Surveillance of sarcoma patients makes up a substantial amount of the workload of a sarcoma unit. The chance of cure following identification of local recurrence or metastatic disease, however, is small. Alternative methods of surveillance that allow better evaluation of the patient's needs are recommended.Cite this article: P. Cool, G. Cribb. The impact and efficacy of surveillance in patients with sarcoma of the extremities. Bone Joint Res 2017;6:224-230. DOI: 10.1302/2046-3758.64.BJR-2016-0253.R1.

Surveillance of intramedullary cartilage tumours in long bones

AIMS

The purpose of this study was to determine if clinical and radiological surveillance of cartilage tumours with low biological activity is appropriate.

PATIENTS AND METHODS

A total of 98 patients with an intramedullary cartilage neoplasm in a long bone met our inclusion criteria and were included in the study. These patients had undergone a total of 384 scans. Patients with radiological follow-up of more than three years (46 patients) were divided into two groups: an active group (11 patients) and a latent group (35 patients).

RESULTS

Active lesions had a total growth in all three planes that was > 6 mm, whilst latent lesions had < 6 mm of growth. Most latent lesions were heavily calcified: active lesions were calcified less than 50% (p = 0.025).

CONCLUSION

Clinico-radiological surveillance can identify growing cartilage lesions: MRI is the surveillance modality of choice. A CT scan is recommended, in addition, at presentation to assess the amount of calcification within the lesion. A first follow-up MRI is suggested one year from diagnosis. If the total growth in the cartilage lesion is > 6 mm, surgical treatment should be considered. Otherwise, a second surveillance scan can be performed at three years to determine further management. Cite this article: Bone Joint J 2016;98-B:1542-7.

A framework for health-related nanomaterial grouping

BACKGROUND

Nanotechnology has been in the limelight since its emergence and its products affect everyday lives. Nanomaterials are characterized by features such as size and shape, thus rendering their possible number essentially unlimited, which in turn makes them difficult to study and categorize regarding possible dangers. This work suggests that grouping could allow studying them with limited testing efforts without endangering safety.

METHODS

Initially, the materials are identified and grouped according to their applications in health/medicine, as well as on their environmentally-friendly potential. The materials are then categorized using various toxicity classification methods to identify those with highest risks and group them with others that demonstrate similar behavior.

RESULTS

The materials studied show promising uses in diagnostics, drug delivery, biosensors, water purification, oil spill cleaning, emission control and other fields. The toxicity risk assessment shows that the majority pose little to moderate risk, however there are certain materials that can be extremely hazardous or even cause death under specific circumstances. A risk mitigation plan was also developed.

CONCLUSIONS

Nanomaterials applications, including drug delivery, cancer treatment, waste treatment, solar energy generation etc. can be very beneficiary, but at the same time, these materials can be extremely harmful or even cause death, thus making the need to prioritize research on high risk materials crucial. A clear regulatory framework that addresses both benefits and risks and communicates that information effectively should play an important part in European and worldwide efforts.

GENERAL SIGNIFICANCE

The risk analysis validated the impression that there is limited research on nanomaterial toxicity risks, which calls for a more organized approach. The framework outlined in this work can be utilized by researchers as well as government bodies, in order to form regulatory policies and adopt a universally accepted labeling system. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

The use of plots in orthopaedic literature

Plots are an elegant and effective way to represent data. At their best they encourage the reader and promote comprehension. A graphical representation can give a far more intuitive feel to the pattern of results in the study than a list of numerical data, or the result of a statistical calculation. The temptation to exaggerate differences or relationships between variables by using broken axes, overlaid axes, or inconsistent scaling between plots should be avoided. A plot should be self-explanatory and not complicated. It should make good use of the available space. The axes should be scaled appropriately and labelled with an appropriate dimension. Plots are recognised statistical methods of presenting data and usually require specialised statistical software to create them. The statistical analysis and methods to generate the plots are as important as the methodology of the study itself. The software, including dates and version numbers, as well as statistical tests should be appropriately referenced. Following some of the guidance provided in this article will enhance a manuscript.

Whole-body magnetic resonance imaging in myxoid liposarcoma: A useful adjunct for the detection of extra-pulmonary metastatic disease

Myxoid liposarcomas (MLS) are a subgroup of soft-tissue sarcomas which have a propensity for extra-pulmonary metastases. Conventional radiological staging of soft-tissue sarcomas consists of chest radiographs (CXR) and thoracic computed tomography (CT) for possible chest metastases, supplemented by magnetic resonance imaging (MRI) for local disease. The optimal radiological modality to detect extra-pulmonary metastases for systemic staging has not been proven. We reviewed the efficacy of Whole-Body MRI (WBMRI) for this purpose. 33 WBMRI and simultaneous CT scans were performed in 28 patients suffering from MLS between 2007 and 2015. 38 metastases were identified in seven patients via WBMRI. Osseous lesions predominated (spine, pelvis, chest-wall and long bones), followed by soft-tissue and abdominal lesions. Of the 29 soft-tissue or osseous metastases that were within the field-of-view of the simultaneous CT scans, five soft-tissue and zero osseous metastases were identified using CT. Metastatic disease was detected in three patients solely using WBMRI, which directly influenced their management. WBMRI is a useful adjunct in the detection of extra-pulmonary metastatic disease, which directly alters patient management. WBMRI has demonstrated an ability to identify more sites of metastatic disease compared to CT. WBMRI should be used in two situations. Firstly, at diagnosis where ablative treatment will be required e.g. amputation, when the diagnosis of occult metastasis would change treatment planning. Secondly, at diagnosis of relapse to confirm if it is a solitary site of relapse prior to consideration of metastectomy.

Physical functioning, pain and quality of life after amputation for musculoskeletal tumours

Patients who have limb amputation for musculoskeletal tumours are a rare group of cancer survivors. This was a prospective cross-sectional survey of patients from five specialist centres for sarcoma surgery in England. Physical function, pain and quality of life (QOL) outcomes were collected after lower extremity amputation for bone or soft-tissue tumours to evaluate the survivorship experience and inform service provision.

Of 250 patients, 105 (42%) responded between September 2012 and June 2013. From these, completed questionnaires were received from 100 patients with a mean age of 53.6 years (19 to 91). In total 60 (62%) were male and 37 (38%) were female (three not specified). The diagnosis was primary bone sarcoma in 63 and soft-tissue tumour in 37. A total of 20 tumours were located in the hip or pelvis, 31 above the knee, 32 between the knee and ankle and 17 in the ankle or foot. In total 22 had hemipelvectomy, nine hip disarticulation, 35 transfemoral amputation, one knee disarticulation, 30 transtibial amputation, two toe amputations and one rotationplasty. The Toronto Extremity Salvage Score (TESS) differed by amputation level, with poorer scores at higher levels (p < 0.001). Many reported significant pain. In addition, TESS was negatively associated with increasing age, and pain interference scores. QOL for Cancer Survivors was significantly correlated with TESS (p < 0.001). This relationship appeared driven by pain interference scores.

This unprecedented national survey confirms amputation level is linked to physical function, but not QOL or pain measures. Pain and physical function significantly impact on QOL. These results are helpful in managing the expectations of patients about treatment and addressing their complex needs.

Cite this article: Bone Joint J 2015;97-B:1284–90.

Intra-epiphyseal stress injury of the proximal tibial epiphysis: preliminary experience of magnetic resonance imaging findings

Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families.

Diffuse pigmented villonodular synovitis (diffuse-type giant cell tumour) of the foot and ankle

Pigmented villonodular synovitis (PVNS) is a rare benign disease of the synovium of joints and tendon sheaths, which may be locally aggressive. We present 18 patients with diffuse-type PVNS of the foot and ankle followed for a mean of 5.1 years (2 to 11.8). There were seven men and 11 women, with a mean age of 42 years (18 to 73). A total of 13 patients underwent open or arthroscopic synovectomy, without post-operative radiotherapy. One had surgery at the referring unit before presentation with residual tibiotalar PVNS. The four patients who were managed non-operatively remain symptomatically controlled and under clinical and radiological surveillance. At final follow-up the mean Musculoskeletal Tumour Society score was 93.8% (95% confidence interval (CI) 85 to 100), the mean Toronto Extremity Salvage Score was 92 (95% CI 82 to 100) and the mean American Academy of Orthopaedic Surgeons foot and ankle score was 89 (95% CI 79 to 100). The lesion in the patient with residual PVNS resolved radiologically without further intervention six years after surgery. Targeted synovectomy without adjuvant radiotherapy can result in excellent outcomes, without recurrence. Asymptomatic patients can be successfully managed non-operatively. This is the first series to report clinical outcome scores for patients with diffuse-type PVNS of the foot and ankle.

Growth in the lower limb following chemotherapy for a malignant primary bone tumour: a straight-line graph

Purpose. The aim of this paper was to assess the growth in the unaffected lower limb of children who had received chemotherapy for a malignant primary bone tumour around the knee.Subjects/methods. Following diagnosis, all children (45, of which 32 were boys and 13 were girls) were staged. If limb-salvage surgery was thought appropriate, measured radiographs of both legs was performed, the bone age was estimated and the expected growth in the femur and tibia was calculated according to Tupman. These procedures were repeated at follow-up and the data plotted. Regression and correlation coefficients were also calculated.Results. The observed regression line in boys was almost identical to Tupman's curve. However, the observed growth in girls was larger than the expected growth.Discussion. It is recommended that the regression lines presented here are used in the calculation of the expected growth in the lower limb of children who have received chemotherapy for a malignant primary bone tumour, especially in girls.

Quality of life in children following treatment for a malignant primary bone tumour around the knee

Purpose. We report on the quality of life following treatment for a malignant primary bone tumour around the knee in skeletally immature children.

Patients. Patients (n = 41; mean age = 18 years; range 8–28) had all experienced chemotherapy in a neo-adjuvant setting, surgical excision of the tumour and endoprosthetic replacement.

Methods. Interviews were conducted separately with the child and mother and focused on mobility, body image and the impact of treatment on schooling, employment and plans for the future.

Results. Mobility in the group was variable. Only 12% reported that they could run with any confidence. The proportion who were able to swim (49%) or ride a bike (46%) was higher. All had experienced major disruption in schooling (mean absence following diagnosis = 12 months). Eight had repeated a school year and 41% patients reported that their schoolwork was affected. As a result of their experience, eight (six females and two males) chose health-related employment. Concerns for the future were highest among males and those with manual jobs. Three patients were receiving psychiatric support, in relation to extreme concern about the risk of recurrence. All expressed satisfaction with treatment, and older patients believed that the prosthesis gave a better quality of life than amputation.

Discussion. Our data suggest that outcome following limb-salvage surgery is variable. Education is disrupted. Even so, only two left school with no qualifications. Employment is most restricted among males with few qualifications who may benefit from sensitive vocational counselling.

New TiO2/MgAl-LDH nanocomposites for the photocatalytic degradation of dyes

In this study we report the synthesis of a series of composite nanostructures comprising LDH and TiO2 phases. The materials characterization showed that the LDH crystallites are encapsulated inside the TiO2 matrix after the anatase seeds are deposited on MgxAl-LDHs. The structure in which LDH phase is embedded into anatase matrix is unique bringing important advantages to the photocatalytic performances of the nanocomposites. The photocatalytic activity of the prepared nanocomposites was tested on the degradation of the methylene blue (MB) in aqueous solution. The photocatalytic activities of the nanocomposites were compared with commercial TiO2 nanoparticles Degussa P25. The nanocomposites exhibited superior photocatalytic activity in basic environment because the negatively charged surface of TiO2 nanoparticles at high pH attracts the positively charged methylene blue species.

Distal tibial giant cell tumour treated with curettage and stabilisation with an Ilizarov frame

A 36-year-old man presented with a long history of pain in his left ankle. Imaging and biopsy confirmed this to be a giant cell tumour of bone. This was treated with curettage of the lesion and stabilisation with an Ilizarov frame. After a prolonged course of rehabilitation he has excellent function and has returned to hill walking and there is no evidence of recurrence of the giant cell tumour.

Is there any microporosity in ordered mesoporous silicas?

The porous structure of nanostructured silicas MCM-41 and SBA-15 has been characterized using N2 adsorption at 77 K, before and after n-nonane preadsorption, together with immersion calorimetry into liquids of different molecular dimensions. Selective blocking of the microporosity with n-nonane proves experimentally that MCM-41 is exclusively mesoporous while SBA-15 exhibits both micro- and mesopores. Additionally, N2 adsorption experiments on the preadsorbed samples show that the microporosity on SBA-15 is located in intrawall positions, the micropore volume accounting for only approximately 7-8 % of the total pore volume. Calorimetric measurements into n-hexane (0.43 nm), 2-methylpentane (0.49 nm), and 2,2-dimethylbutane (0.56 nm) estimate the size of these micropores to be < or = 0.56 nm.

Multistep loading of titania nanoparticles in the mesopores of SBA-15 for enhanced photocatalytic activity

A multistep deposition of anatase nanoparticles was employed to incorporate high amounts of titania into the mesopores of SBA-15. Anatase nanoparticles were synthesized and deposited following the Acid Catalyzed Sol Gel method. With this method, the size of the anatase nanoparticles can be controlled and therefore, the titania loading into the mesopores of SBA-15 can be controlled. Through multistep deposition of anatase nanoparticles, a further increase of titania loading into the mesoporous channels can be obtained. For the degradation of Rhodamine-6G, the samples synthesized by multistep deposition showed an enhanced photocatalytic activity.

Preparation and Characterization of Vanadium Oxide Deposited on Thermally Stable Mesoporous Titania

Vanadium oxide was deposited on mesoporous titania by the molecular designed dispersion method to investigate the potential properties of these catalysts. Mesoporous titania was synthesized following the evaporation-induced self-assembly (EISA) method with a subsequent treatment with ammonia to increase the thermal stability. As a result, the mesoporous titania obtained shows a high surface area (approximately 350 m2/g) and high stability. Vanadium oxide was deposited by the MDD method using a vanadyl acetylacetonate complex that was transformed into VOx after a controlled calcination in air flow at 300 degrees C. The mesostructure and porosity characteristics of titania remain even until the maximum V-loading was reached (0.4 mmol/g), as it was shown by N2 sorption measurements at -196 degrees C. The catalysts were characterized by chemical analysis, Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS), UV-vis diffuse reflectance (DR), and Fourier transform Raman spectroscopy. Raman spectra showed isolated V species for the different V-containing catalysts. Furthermore, UV-vis-DR revealed a higher contribution of polymeric species as the V loading increases. The VOx/mesoporous titania catalysts were highly active in the selective catalytic reduction of NOx. A high activity in the NO conversion was observed, which increases with increasing metal loading.

Surveillance in patients with sarcoma of the extremities

AIM

To evaluate the efficiency of our follow-up regime for patients with sarcoma of the extremities.

METHODS

We have reviewed our follow-up policy in 480 patients with non-metastatic bone or soft tissue sarcomas and with more than 5 years of follow-up.

RESULTS

We detected 24% of the soft tissue sarcoma recurrences and 38% of the bone tumour recurrences. We detected 67% of the pulmonary metastases before they became symptomatic. Only 11% of those patients who developed metastases were cured, as were only 26% of those who developed local recurrence.

CONCLUSIONS

This study shows that our surveillance programme detects most metastases, but only about one third of the local recurrences.

Percutaneous radiofrequency thermocoagulation of osteoid osteomas: factors affecting therapeutic outcome

OBJECTIVE

To examine factors which affect local recurrence of osteoid osteomas treated with percutaneous CT-guided radiofrequency thermocoagulation.

DESIGN AND PATIENTS

A prospective study was carried out on 45 patients with osteoid osteoma who underwent percutaneous radiofrequency thermocoagulation with a minimum follow-up of 12 months.

RESULTS

There were seven local recurrences (16%); all occurred within the first year. Local recurrence was significantly related to a non-diaphyseal location (P<0.01). There was no significant relationship (P=0.05) between local recurrence and age of the patient, duration of symptoms, previous treatment, size of the lesion, positive biopsy, radiofrequency generator used or the number of needle positions. There were no complications.

CONCLUSIONS

Osteoid osteomas in a non-diaphyseal location are statistically more likely to recur than those in a diaphyseal location when treated with CT-guided percutaneous radiofrequency thermocoagulation. This relationship between local recurrence and location has not been previously reported.

Influence of polymer matrix and adsorption onto silica materials on the migration of alpha-tocopherol into 95% ethanol from active packaging

In this study, the effect of polymer materials with different polarity, namely low density polyethylene (LDPE) and ethylene vinyl acetate (EVA), on the migration behaviour of alpha-tocopherol from active packaging was investigated. The antioxidant was also adsorbed onto silica materials, namely SBA-15 (Santa Barbara-15) and Syloblock, in order to protect the antioxidant during extrusion and to ensure a controlled and sufficient release during the shelf-life of the food product. Migration experiments were performed at 7.0 +/- 0.5 degrees C and 95% ethanol was used as fatty food simulant. All films contained a high concentration of alpha-tocopherol, approximately 2000 mg kg(-1), to obtain an active packaging. Polymer matrix had a small influence on the migration profile. The migration of 80% of total migrated amount of antioxidant was retarded for 2.4 days by using LDPE instead of EVA. When alpha-tocopherol was adsorbed onto both silica materials, the migration of 80% of total migrated amount of antioxidant was retarded for 3.4 days in comparison to pure alpha-tocopherol. No difference was seen between the migration profiles of alpha-tocopherol adsorbed onto both silica materials. In the case of pure alpha-tocopherol, 82% of the initial amount of alpha-tocopherol in the film migrated into the food simulant at a rather fast migration rate. In the case of adsorption on silica materials, a total migration was observed. These antioxidative films can have positive food applications.

Characterization of Vanadium and Titanium Oxide Supported SBA-15

Supported vanadium and titanium oxide catalysts were prepared by adsorption and subsequent calcination of the vanadyl and titanyl acetylacetonate complexes, respectively, on mesoporous SBA-15 by the molecular designed dispersion (MDD) method. Liquid and gas phase depositions at different temperatures were carried out with vanadyl acetylacetonate, and the different results together with those of titanyl acetylacetonate in the liquid phase deposition were discussed. The bonding mechanism, the influence of the metal interaction with the support material, and differences due to the way of deposition and the temperature were investigated by TGA, chemical analysis, FTIR, and Raman spectroscopy. Elevated dissolving temperatures in the liquid phase led to higher final loadings on the SBA-15 without the formation of clusters, even at high loadings. The decomposition of the anchored vanadium and titanium complexes, their thermal stability, and the conversion to the covalently bound VO(x) and TiO(x) species on SBA-15 were studied and investigated by in situ transmission IR spectroscopy. In general, the titanium complex is more reactive than the vanadium complex toward the surface of SBA-15 and has a higher thermal stability. The MDD method of the VO(acac)2 and TiO(acac)2 enables to create a dispersed surface of supported VO(x) and TiO(x), respectively. The structure configurations of VO(x) and TiO(x) oxide catalysts obtained at different metal loadings were studied by Raman spectroscopy. Pore size distributions, XRD, and N2 sorption confirmed the structural stability of these materials after grafting. VO(x)/SBA-15 and TiO(x)/SBA-15 samples, with different metal loadings, were also catalytically tested for the selective catalytic reduction (SCR) of NO with ammonia.

Design and applications of a home-built in situ FT-Raman spectroscopic cell

In the field of heterogeneous catalysis, in situ spectroscopy is one of the topics with growing interest. The characterization of a catalyst under working conditions is essential to identify the catalytic active site and to study the relation between the surface structure of a catalyst and its catalytic performance. For the first time, the design of an in situ spectroscopic cell for FT-Raman is presented and its performance is demonstrated by monitoring the thermal conversion of as synthesized mesoporous titanium and by characterizing the molecular surface structure of the vanadium oxides grafted on MCM-48 after exposure to a probe molecule. The results in both cases indicate that the in situ FT-Raman cell is a promising technique for characterizing the molecular surface structure of catalyst materials.

Effects of strontium on the physicochemical characteristics of hydroxyapatite

In a previous experimental study using a chronic renal failure rat model, a dose-related multiphasic effect of strontium (Sr) on bone formation was found that could be reproduced in an in vitro set-up using primary rat osteoblasts. The results from the latter study allowed us to distinguish between a reduced nodule formation in the presence of an intact mineralization at low Sr-doses (1 microg/ml) and an interference of the element with the hydroxyapatite (HA) formation at high doses (20-100 microg/ml). To further investigate the latter effect of Sr on physicochemical bone mineral properties, an in vitro study was set up in which the UMR-106 rat osteosarcoma cell line was exposed to Sr, added to the cell culture medium in a concentration range varying between 0-100 microg/ml. Temporal growth and functionality of the culture was investigated by measurement of the alkaline phosphatase activity and calcium (Ca) concentration in the culture medium (used as an index of Ca-incorporation, i.e., HA formation) at various time points. At the end of the culture period (14 days post-confluence), samples of the mineralized cultures were taken for further analysis using X-ray diffraction (XRD) and Fourier Transform Infra-Red Spectroscopy (FTIR). Synthetic HA doped with various Sr concentrations (based on the cell culture and previous experimental studies and yielding Sr/(Sr + Ca) ratios ranging from 0-60%), was prepared and examined for crystal growth and solubility. Crystal size was assessed using scanning electron microscopy (SEM). Ca incorporation indicated a reduced mineralization in the 20 and 100 microg/ml Sr groups vs. controls. Sr-doped synthetic HA showed a significant dose-dependent reduction in crystal growth, as assessed by SEM, and an increase in solubility, apparent from 12.7% Sr/(Sr + Ca) on. Moreover, in both mineralized cultures and synthetic HA, XRD and FTIR analysis showed a reduced crystallinity and altered crystal lattice at similar concentrations. These new data support our previous in vivo and in vitro findings and point to a potential physicochemical interference of Sr with HA formation and crystal properties in vivo.

Post-synthesis deposition of V-zeolitic nanoparticles in SBA-15

A post-synthesis deposition of vanadium silicalite-1 zeolite nanoparticles in the pores of SBA-15 results in a highly ordered hexagonal templated silica material with V-silicalite zeolitic plugs, giving rise to an increased crystallinity of the amorphous mesoporous walls.

The incidence, location and distribution of degenerative subchondral acetabular cysts in primary osteoarthrosis of the hip

Degenerative subchondral acetabular cysts are a common finding in patients with primary osteoarthritis of the hip. These mainly occur in the superior weight-bearing region of the acetabulum. The aim of this study was to identify the presence and distribution of degenerative acetabular cysts in patients with primary osteoarthritis of the hip. The radiographs of 100 consecutive patients who had a total hip replacement for primary osteoarthritis of the hip were retrospectively analyzed. Eighty-two patients had degenerative subchondral cysts. Of these 44% were solitary. All the cysts occupied the superior zone of the acetabulum with a proportion extending into the middle zone. None involved the inferior zone, the medial acetabular wall. The radiological presence of an acetabular cyst in the inferior zone (medial acetabular wall) warrants further investigation, and should not be presumed to represent a feature of osteoarthritis, even if osteoarthritis is present. (Hip International 2004; 14: 24-7).

A new strategy towards ultra stable mesoporous titania with nanosized anatase walls

A new and generally applicable synthesis procedure is developed in order to synthesise micelle-templated mesoporous titania built up of nanosized anatase walls with thermal stability up to 600 degrees C.

Mesoporous templated silicates: an overview of their synthesis, catalytic activation and evaluation of the stability

The most recent developments in the formation of new mesoporous templated zeolitic materials, characterized by surfaces of more than 1000 m(2)/g, are discussed in this paper. By adapting the synthesis parameters, such as type of silicium source, type of template, pH, temperature, em leader different materials can be synthesized with varying porosity and crystallinity. Besides the synthesis, much attention is focused on the activation of their surfaces by incorporation methods or deposition processes towards catalytic applications. Finally, the stability of the different materials, one of the critical parameters to potential industrial applications, is compared and evaluated.

Plugged hexagonal templated silica: a unique micro- and mesoporous composite material with internal silica nanocapsules

We describe in this paper the development of plugged hexagonal templated silicas (PHTS) which are hexagonally ordered materials, with internal microporous silica nanocapsules; they have a combined micro- and mesoporosity and a tuneable amount of both open and encapsulated mesopores and are much more stable than other tested micellar templated structures.