Laryngeal graft after total laryngectomy in humans: A SWiM analysis

Evaluation of the results of laryngeal transplantation (LT) in humans. Analysis of 3 bibliographic databases with the keywords "larynx, transplantation, autograft". In total, 626 abstracts were read and 25 articles selected. The main objective was to analyze the characteristics of laryngeal transplant patients. The accessory objectives comprised analysis of operative technique, immunosuppressive treatment and results. Four articles were selected for analysis. Two patients were transplanted after total laryngectomy for laryngeal carcinoma and 2 after laryngeal trauma. Three of the 4 patients had true transplantation with arterial, venous and neural microanastomosis. Two patients were decannulated and the tracheostomy tube was maintained in the other 2. Three of the 4 patients had good-quality phonation and could feed without a gastric tube. One patient died of carcinoma progression and 1 patient had to be explanted 14 years after transplantation. The number of LTs reported is too small for scientific determination of the place of this intervention in laryngology. The published results could, at first sight, suggest that the future of LT is uncertain. However, several elements, also suggest that otolaryngologists should continue to take an interest in this technique.

[Meralgia paraesthetica as complication of patient positioning : A not fully controllable risk]

Als Meralgia paraesthetica (MP) bezeichnet man eine zu den neurologischen Engpasssyndromen zählende Schädigung des aus dem Plexus lumbalis entspringenden sensiblen N. cutaneus femoris lateralis. Symptome sind temporäre oder bleibende Parästhesien und Schmerzen an der Vorder- und Außenseite des Oberschenkels. Die MP kann idiopathisch auftreten, sich genuin als z. B. „seat belt syndrome“ oder „Jeans-Syndrom“ verwirklichen, sie kann aber auch Folge eines operativen Eingriffs oder einer chirurgischen bzw. intensivmedizinischen Lagerung sein. Im Fokus stehen hierbei in der Literatur die Steinschnitt-, die Bauch- und die „Beach-chair“-Lagerung.

Analysiert wurden 21 Beschwerden über eine postoperativ erstmals aufgetretene MP, die bei der Gutachterkommission für ärztliche Behandlungsfehler bei der Ärztekammer Nordrhein im Verlauf der letzten 10 Jahre eingereicht wurden. Unter diesen konnten 6 Fälle als Lagerungsschaden nach Steinschnittlagerung identifiziert werden; in 3 Fällen trat eine MP nach Rückenlagerung auf; die Ätiologie konnte nicht sicher geklärt werden. In 12 Fällen wurde die MP als direkte Operationskomplikation erkannt.

Pathophysiologie, Inzidenz und Verlauf sowie juristische Implikationen der lagerungsbedingten MP werden beschrieben. Als hauptsächlicher Pathomechanismus wird eine Druckschädigung des Nervs an seiner Kreuzungsstelle mit dem Leistenband diskutiert. Wenngleich alle hier vorgestellten Fälle nach der Steinschnittlagerung auftraten, scheint sich die Komplikation nach Literaturdaten auch bei anderen Lagerungsarten, am häufigsten möglicherweise bei Bauchlagerungen, zu verwirklichen. Dies erklärt auch die zunehmenden Fallberichte einer MP nach Bauchlagerung bei COVID-19-Patient*innen. Eine sichere Vermeidung der lagerungsbedingten Komplikation erscheint aufgrund der anatomischen Variabilität des Nervenverlaufs und der unklaren Pathomechanismen nicht möglich.

Control of the acoustic waves generated by intense laser filamentation in water

Experiments and simulations are performed to study filamentation and generation of acoustic waves in water by loosely focused multi-millijoules laser pulses. When the laser pulse duration is increased from femtosecond to nanosecond duration, a transition is observed from a filamentary propagation with extended and low energy density deposition to a localized breakdown, related to high energy density deposition. The transition suggests that Kerr self-focusing plays a major role in the beam propagation dynamics. As a result, the shape, the amplitude and the spectrum of the resulting pressure wave present a strong dependence on the laser pulse duration.

[Thalamic infarction following paradoxical embolism during total hip replacement : Case report and pathophysiological considerations]

Because of a painful right-sided coxarthrosis a 57-year-old female patient underwent a cementless total arthroplasty under general anesthesia. Except for Asperger's syndrome and an occlusion of a vein in her left eye she stated no other diseases or complaints, especially no cardiac problems. Postoperatively she developed neurological symptoms of left-sided hemiparesis and hemihypesthesia. A cranial computer tomography was performed and a right-sided infarction of the thalamic region was found. A patent foramen ovale (PFO) and atrial septal aneurysm were detected 5 days later. The incidence of a PFO is given as 25% of the population. A paradoxical air embolism in the presence of a PFO is a feared complication in neurosurgical interventions in a semi-sitting or sitting position. Corpuscular emboli, such as bone, cement, fat or wound debris may be the reason for paradoxical embolisms in combination especially with partial or total hip replacement. The kind of embolism in the case described could not be clarified. Deep vein thrombosis or cardiac arrhythmia could be excluded. Therefore, it can be considered most likely that the operation site was the source of the embolism. The trigger for a paradoxical embolism is a reversal of the pressure difference between the right and left atria: normally the left atrial pressure exceeds the right atrial pressure by ca. 2-4 mm Hg, resulting possibly in a small clinically irrelevant left-to-right shunt. If the pulmonary arterial circulation is compromised and pulmonary vascular resistance increases, the pressure gradient between the left and right atria reverses and a right-to-left shunt can occur causing a paradoxical embolism. Positive end-expiratory pressure (PEEP) ventilation during anesthesia could be an important reason for a shunt reversal between the right and left atria and therefore favoring a paradoxical embolism but the pathophysiological role of PEEP has not yet been finally clarified.

[Arachnoiditis following spinal anesthesia-Case report and review of the literature]

A 61-year-old woman underwent a tension-free vaginal tape (TVT) operation due to stress incontinence. After technically difficult spinal anesthesia with two attempts the patient developed symptoms of nerve irritation, complained about neckache and headache and showed signs of agitation. The regimen was shifted to general anesthesia and surgery was performed. Because of postoperatively persistent headache and sensory disturbances an MRI scan of the lumbar spine was performed on the first postoperative day without pathological findings. The patient was able to leave the hospital after 1 week with significant relief of symptoms but 3 weeks later she developed neurocognitive impairment with memory deficits. A second MRI scan of the head now showed signs of disturbance of CSF circulation with hydrocephalus. Treatment was performed with drainage and ventriculoperitoneal shunt. Further evaluation showed a severe, multisegmental arachnoiditis and the patient developed a progressive paraparesis. The patient presented her case for assessment to a commission on medical malpractice 13 months after anesthesia. The commission detected no treatment errors. In connection to the case report a literature review of characteristics and etiologies of chronic adhesive arachnoiditis is given, which is a known but very rare complication of spinal anesthesia or similar procedures.

Relevance of heat stress and dehydration to chronic kidney disease (CKDu) in Sri Lanka

Chronic kidney disease in the absence of hypertension and diabetes is a growing problem among agricultural laborers in tropical and subtropical regions. It is unclear if heat stress and dehydration are risk factors for this form of chronic kidney disease (CKDu). To investigate this relationship, agricultural workers in four villages (n = 261) in North Central Province, Sri Lanka completed the US National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation of heat stress, translated into Sinhalese (July 2017). We constructed a heat stress/dehydration index based on the frequency of 16 symptoms (range 0-32; reliability, 0.84). Workers provided a urine sample for dipstick assessment of urine albumin-creatinine ratio (ACR) and refractometer analysis of urine concentration. Of 261 respondents, 41 participants reported diabetes or chronic kidney disease. They scored higher on the heat stress-dehydration index (10.78 vs. 8.03, p < .01) and were more likely to have ACR > 30 (85.4% vs. 69.4%, p < .05). Among 216 non-pregnant agricultural workers without diabetes or kidney disease (mean age, 46.6; 37% male), villagers in the high-CKDu prevalence area were more likely to show signs of dehydration (for example, greater urine concentration, 1.015 vs. 1.012, p < .05, among males); however, the heat stress-dehydration index overall was not associated with ACR or urine concentration. Because an elevated ACR (proteinuria) is not a reliable marker of early CKDu, additional studies are needed to assess the association between heat stress-dehydration symptoms and risk of CKDu.

Assessment of swallowing function after circumferential pharyngolaryngectomy. A multicenter study by the GETTEC group

OBJECTIVE

Circumferential pharyngolaryngectomy is performed for advanced pharyngeal tumor or in a context of postradiation recurrence. Several free or pedicle flaps have been described for pharyngeal defect reconstruction, with choice at the surgeon's discretion. The aim of this study was to evaluate long-term swallowing function according to the type of flap used for reconstruction.

MATERIAL AND METHOD

A multicenter retrospective study was conducted from January to September 2016 within the French GETTEC head and neck tumor study group. All patients in remission after circumferential pharyngolaryngectomy were included and filled out the Deglutition Handicap Index (DHI) questionnaire and underwent swallowing function fiberoptic endoscopy assessment. 46 patients (39 men, 7 women) were included. Reconstruction used a tubularized forearm free flap (FFF group) in 19 cases, pectoralis major myocutaneous flap (PMMF group) in 15 cases and free jejunum flap (FJF group) in 12 cases.

RESULTS

Mean DHI was 24: 20 in the FFF group, 23 in the FJF group and 25 in the PMMF group, without significant differences. 27 patients had normal swallowing, 9 mixed diet, 8 liquid diet and 3 were fed by gastrostomy. On endoscopy, free flaps (FJF and FFF) were associated with significantly greater rates of normal swallowing of saliva and yogurt than in the PMMF group (P=0.04).

CONCLUSION

Type of flap reconstruction after circumferential pharyngolaryngectomy had no significant impact on postoperative swallowing function assessed on the self-administered DHI questionnaire.

Improving supersonic flights with femtosecond laser filamentation

When a flying object becomes supersonic, a concomitant increase in drag leads to a considerable rise in fuel consumption. We show experimentally that an embarked terawatt femtosecond laser can significantly decrease this drag. We measured a 50% transient reduction of drag on a test model placed in a supersonic wind tunnel at Mach 3. This effect was initiated by the thin hot air column created in front of the supersonic object by filamentation of the laser pulse. We also show that this technique offers possibilities for steering.

International consensus (ICON) on functional and aesthetic rhinoplasty

During the 2017 IFOS international congress in Paris, a roundtable discussion on the topic of functional and aesthetic rhinoplasty was organised. Five experts, from the five continents and renown in the field of rhinoplasty, were brought together to discuss the issue from an international perspective and to put forward a consensus or on the contrary practical differences. Five questions were put to the experts beforehand to guarantee independent answers, which were then discussed during the roundtable. The questions were the following: - What are the age limits for achieving a rhinoplasty? - Do you use objective measurements before, during and after surgery? (facial landmarks, airflow, peroperative measurements) - How do you manage the preoperative general information and computer imaging of the patient? - What are the indications in your practice to perform a CT-scan or endoscopic examination before doing a rhinoplasty? - What kind of graft or prosthesis do you use for an augmentation rhinoplasty? This paper offers a synthesis of the roundtable based on the experts' answers to the different questions.

Unifying different interpretations of the nonlinear response in glass-forming liquids

This work aims at reconsidering several interpretations coexisting in the recent literature concerning nonlinear susceptibilities in supercooled liquids. We present experimental results on glycerol and propylene carbonate, showing that the three independent cubic susceptibilities have very similar frequency and temperature dependences, for both their amplitudes and phases. This strongly suggests a unique physical mechanism responsible for the growth of these nonlinear susceptibilities. We show that the framework proposed by two of us [J.-P. Bouchaud and G. Biroli, Phys. Rev. B 72, 064204 (2005)PRBMDO1098-012110.1103/PhysRevB.72.064204], where the growth of nonlinear susceptibilities is intimately related to the growth of glassy domains, accounts for all the salient experimental features. We then review several complementary and/or alternative models and show that the notion of cooperatively rearranging glassy domains is a key (implicit or explicit) ingredient to all of them. This paves the way for future experiments, which should deepen our understanding of glasses.

Selective area growth of AlN/GaN nanocolumns on (0001) and (11-22) GaN/sapphire for semi-polar and non-polar AlN pseudo-templates

Despite the strong interest in optoelectronic devices working in the deep ultraviolet range, no suitable low cost, large-area, high-quality AlN substrates have been available up to now. The aim of this work is the selective area growth of AlN nanocolumns by plasma assisted molecular beam epitaxy on polar (0001) and semi-polar (11-22) GaN/sapphire templates. The resulting AlN nanocolumns are vertically oriented with semi-polar {1-103} top facets when grown on (0001) GaN/sapphire, or oriented at 58° from the template normal and exposing {1-100} non-polar top facets when growing on (11-22) GaN/sapphire, in both cases reaching filling factors ≥80%. In these kinds of arrays each nanostructure could function as a building block for an individual nano-device or, due to the large filling factor values, the overall array top surfaces could be seen as a quasi (semi-polar or non-polar) AlN pseudo-template.

High-resolution FTIR spectroscopy of trisulfane HSSSH: a candidate for detecting parity violation in chiral molecules

We present the first analysis of high resolution infrared spectra for trisulfane, a candidate to measure molecular parity violation.

[Diverging detection limits of immunochemical tests for occult blood underline the necessity of standardization and quality assurance]

BACKGROUND

Immunological fecal occult blood tests (FIT) are superior in detecting colorectal cancer and its precursors compared to conventional Guajac-based tests. Besides quantitative, laboratory-based FITs qualitative, office-based FITs are increasingly employed. Studies have shown major variation of these tests with respect to sensitivity and specificity, which is most probably caused by different detection limits. In the present study we therefore determined and compared the detection limits and other criteria of commercial FITs.

METHODS

We determined the detection limits for 21 qualitative and one quantitative FIT using commercial control solutions with defined hemoglobin (Hb) concentrations. These detection limits were compared with the manufacturers' data.

RESULTS

The detection limits of the tests showed a wide range of 2 to over 60 µg Hb per gram stool. In many cases the detection limits we determined were not in accordance with the manufacturers' data. Two tests didn't show a positive reaction even with the highest hemoglobin concentration of 440 ng/mL. On the other hand one test showed a positive reaction even at the lowest hemoglobin concentration of 25 ng/mL.

CONCLUSION

The large differences in the detection limits found in this study are consistent with observations of large variation of sensitivity and specificity of qualitative FITs in screening practice. Proper clinical validation of each FIT is to be required before admission for colorectal cancer screening. An additional regular quality control, i. e. by means of external quality control measures and documentation of results of colonoscopies following positive tests results, should be mandatory.

Titanium induced polarity inversion in ordered (In,Ga)N/GaN nanocolumns

We report on the formation of polarity inversion in ordered (In,Ga)N/GaN nanocolumns grown on a Ti-masked GaN-buffered sapphire substrate by plasma assisted molecular beam epitaxy. High-resolution transmission electron microscopy and electron energy-loss spectroscopy reveal a stacking fault-like planar defect at the homoepitaxial GaN interface due to Ti incorporation, triggering the generation of N-polar domains in Ga-polar nanocolumns. Density functional theory calculations are applied to clarify the atomic configurations of a Ti monolayer occupation on the GaN (0002) plane and to prove the inversion effect. The polarity inversion leads to an enhanced indium incorporation in the subsequent (In,Ga)N segment of the nanocolumn. This study provides a deeper understanding of the effects of Ti mask in the well-controlled selective area growth of (In,Ga)N/GaN nanocolumns.

Merkel cell carcinoma: value of sentinel lymph-node status and adjuvant radiation therapy

BACKGROUND

Sentinel lymph-node (LN) biopsy (SLNB) is a valuable tool to assess the regional LN status in Merkel cell carcinoma (MCC). However, its prognostic value is still debated. This study was undertaken to assess SLNB usefulness for MCC management and to determine the impact of SLNB status on disease-free survival (DFS) and overall survival (OS) by comparing SLNB-positive versus -negative patients according to demographic, clinical and treatment characteristics.

PATIENTS AND METHODS

In this retrospective, multicenter observational study, SLNB was proposed to all patients referred for clinically N0 MCC. Treatment schedule consisted of wide-margin surgical resection of primary MCC followed by adjuvant radiation therapy (aRT) to the primary site and, for SLNB-positive patients, radical LN dissection followed by regional aRT. Univariate and multivariate analyses determined factors associated with DFS and OS.

RESULTS

Among 87 patients with successful SLNB, 21 (24.1%) were SLNB-positive. Median follow-up for the entire series was 39 months; respective 3-year DFS and OS rates were 73% and 81.4%, respectively. Univariate analysis (all patients) identified SLNB-negativity as being associated with prolonged OS (P = 0.013) and aRT (all sites considered) was associated with longer DFS (P = 0.004) and OS (P = 0.018). Multivariate analysis (all patients) retained SLNB status and aRT (all sites considered) as being associated with improved DFS (P = 0.014 and 0.0008) and OS (P = 0.0020 and 0.0019). Moreover, for SLNB-negative patients, tumor-bed irradiation was also significantly associated with prolonged DFS (P = 0.006) and OS (P = 0.014).

CONCLUSIONS

The present study demonstrates that SLNB-negativity is a strong predictor of longer DFS and OS in stage I and II MCC patients. The similar benefit for aRT on tumor bed observed in this study has to be confirmed by a prospective study. The results advocate for SLNB being considered to all MCC patients.

High resolution GHz and THz (FTIR) spectroscopy and theory of parity violation and tunneling for 1,2-dithiine (C4H4S2) as a candidate for measuring the parity violating energy difference between enantiomers of chiral molecules

Our results show that this molecule is a suitable candidate for a possible first determination of the parity violating energy difference Δ_pvE between enantiomers.

Distinguishing cubic and hexagonal phases within InGaN/GaN microstructures using electron energy loss spectroscopy

3D InGaN/GaN microstructures grown by metal organic vapor phase epitaxy (MOVPE) and molecular beam epitaxy (MBE) have been extensively studied using a range of electron microscopy techniques. The growth of material by MBE has led to the growth of cubic GaN material. The changes in these crystal phases has been investigated by Electron Energy Loss Spectroscopy, where the variations in the fine structure of the N K‐edge shows a clear difference allowing the mapping of the phases to take place. GaN layers grown for light emitting devices sometimes have cubic inclusions in the normally hexagonal wurtzite structures, which can influence the device electronic properties. Differences in the fine structure of the N K‐edge between cubic and hexagonal material in electron energy loss spectra are used to map cubic and hexagonal regions in a GaN/InGaN microcolumnar device. The method of mapping is explained, and the factors limiting spatial resolution are discussed.

Generation and optimization of the self-administered bleeding assessment tool and its validation as a screening test for von Willebrand disease

INTRODUCTION/AIM

Our aim was to generate, optimize and validate a self-administered bleeding assessment tool (self-BAT) for von Willebrand disease (VWD).

METHODS

In Phase 1, medical terminology in the expert-administered International Society on Thrombosis and Haemostasis (ISTH)-BAT was converted into a Grade 4 reading level to produce the first version of the Self-BAT which was then optimized to ensure agreement with the ISTH-BAT. In Phase 2, the normal range of bleeding scores (BSs) was determined and test-retest reliability analysed. In Phase 3, the optimized Self-BAT was tested as a screening tool for first time referrals to the Haematology clinic.

RESULTS

Bleeding score from the final optimized version of the Self-BAT showed an excellent intra-class correlation coefficient (ICC) of 0.87 with ISTH-BAT BS in Phase 1. In Phase 2, the normal range of BSs for the optimized Self-BAT was determined to be 0 to +5 for females and 0 to +3 for males and excellent test-retest reliability was shown (ICC = 0.95). In Phase 3, we showed that a positive Self-BAT BS (≥6 for females, ≥4 for males) has a sensitivity of 78%, specificity of 23%, positive predictive value (PPV) of 0.15 and negative predictive value (NPV) of 0.86 for VWD; these figures improved when just the females were analysed; sensitivity of 100%, specificity of 21%, PPV = 0.17 and NPV = 1.0.

CONCLUSION

We show an optimized Self-BAT can generate comparable BS to the expert-administered ISTH-BAT and is a reliable, effective screening tool to incorporate into the assessment of individuals, particularly women, referred for a possible bleeding disorder.

Light-emitting-diodes based on ordered InGaN nanocolumns emitting in the blue, green and yellow spectral range

The growth of ordered arrays of InGaN/GaN nanocolumnar light emitting diodes by molecular beam epitaxy, emitting in the blue (441 nm), green (502 nm), and yellow (568 nm) spectral range is reported. The device active region, consisting of a nanocolumnar InGaN section of nominally constant composition and 250 to 500 nm length, is free of extended defects, which is in strong contrast to InGaN (planar) layers of similar composition and thickness. Electroluminescence spectra show a very small blue shift with increasing current (almost negligible in the yellow device) and line widths slightly broader than those of state-of-the-art InGaN quantum wells.

Inflammatory myofibroblastic tumours of the maxillary sinus: A brief clinical report and review of the literature

Although inflammatory myofibroblastic tumours (IMTs) have been accepted as a clonal neoplasm, their pathology is poorly understood due to variable presentation. There is no identifiable cause and they are usually observed as tumour growth combined with inflammation. In the current WHO classification, IMTs are designated as intermediate malignancies. In terms of biological potential, IMTs are classified under 'rarely metastasizing'. IMTs are rare in the maxillary sinus but, when reported, can be locally aggressive or even destructive if they invade the orbit. The authors present a brief clinical report describing a five-year-old girl with a slow-growing mass in the right maxillary sinus extending into the lacrimal sac and its management.

Management of somatic pain induced by treatment of head and neck cancer: Postoperative pain. Guidelines of the French Oto-Rhino-Laryngology--Head and Neck Surgery Society (SFORL)

OBJECTIVE

To present the guidelines of the French Oto-Rhino-Laryngology--Head and Neck Surgery Society (SFORL) concerning the management of somatic pain induced by the treatment of head and neck cancer, and in particular the management of early and late post-surgical pain.

METHODS

A multidisciplinary work group conducted a review of the scientific literature on the study topic. An editorial group subsequently read the resulting guidelines before validation.

RESULTS

It is recommended to prevent onset of pain caused by malpositioning on the operating table, as well as pain related to postoperative care. During surgery, it is recommended to spare nerve and muscle structures as far as possible to limit painful sequelae. Management of early postoperative pain upon tumor resection and flap harvesting sites requires patient-controlled analgesia by morphine pump. Physical therapy is recommended after flap harvesting to minimize painful sequelae.

CONCLUSION

Preventive and curative measures should be undertaken for appropriate management of post-surgical pain in the treatment of head and neck cancers.

Indicators of coral reef ecosystem recovery following reduction in logging and implementation of community-based management schemes in the Solomon Islands

The livelihood of many coastal communities in the Pacific Islands is directly dependent on the health of adjacent coral reefs. Reduction in water quality and over-harvesting of herbivorous fish are known to drive reef ecosystems towards a more degraded state. Community-based resource management practices have the potential to improve damaged reefs but quantitative data on their effectiveness remains largely unreported. This study investigated how land use changes and implementation of marine management influenced water quality, herbivorous fish biomass and reef condition of Marovo Lagoon in the Solomon Islands. Four study sites were located along a gradient of water quality, with two of the sites located inside marine protected areas (MPAs) designated in 2006. The results suggest that water quality in coastal areas adjacent to catchments modified by logging was negatively impacted. However, following natural revegetation of bare soil in the catchment between 2000 and 2010, water quality improved at all sites. The biomass of herbivorous fish was significantly greater in the MPAs compared to other sites and, importantly, we detected an increase in herbivore biomass between 2005 and 2008. Inshore reefs adjacent to logging operations had significantly lower coral cover and higher macroalgal cover than those offshore. Between 2005 and 2008 all sites showed an increase in crustose coralline algae cover and a decrease in turf algae colonising rocks, with the changes indicative of improving reef health. Collectively, these results indicate that reduction in logging and implementation of community-based management can have a positive influence on reefs in Marovo Lagoon.

Adherence to consensus-based diagnosis and treatment guidelines in adult soft-tissue sarcoma patients: a French prospective population-based study

BACKGROUND

Soft-tissue sarcomas (STSs) are rare tumors with varied histological presentations. Management and treatment are thus complex, but crucial for patient outcomes. We assess adherence to adult STS management guidelines across two French regions (10% of the French population). We also report standardized incidence.

PATIENTS AND METHODS

STS patients diagnosed from 1 November 2006 to 31 December 2007 were identified from pathology reports, medical hospital records, and cancer registries. Guideline adherence was assessed by 23 criteria (validated by Delphi consensus method), and age and sex-standardized incidence rates estimated. Associations between patient, treatment, and institutional factors and adherence with three major composite criteria relating to diagnostic imaging and biopsy as well as multidisciplinary team (MDT) case-review are reported.

RESULTS

Two hundred and seventy-four patients were included (57.7% male, mean age 60.8 years). Practices were relatively compliant overall, with over 70% adherence for 10 criteria. Three criteria with perfect Delphi consensus had low adherence: receiving histological diagnosis before surgery, adequacy of histological diagnosis (adherence around 50% for both), and MDT discussion before surgery (adherence <30%). Treatment outside of specialized centers was associated with lower adherence for all three composite criteria, and specific tumor sites and/or features were associated with lower adherence for diagnostic imaging, methods, and MDT meetings. STS standardized incidence rates were 4.09 (European population) and 3.33 (World) /100 000 inhabitants.

CONCLUSIONS

Initial STS diagnosis and treatment across all stages (imaging, biopsy, and MDT meetings) need improving, particularly outside specialized centers. Educational interventions to increase surgeon's sarcoma awareness and knowledge and to raise patients' awareness of the importance of seeking expert care are necessary.

Selective area growth of In(Ga)N/GaN nanocolumns by molecular beam epitaxy on GaN-buffered Si(111): from ultraviolet to infrared emission

Selective area growth of In(Ga)N/GaN nanocolumns was performed on GaN-buffered Si(111) substrates by plasma-assisted molecular beam epitaxy. Undoped and Si-doped GaN buffer layers were first grown on Si(111) substrates, showing photoluminescence excitonic emission without traces of other low energy contributions, in particular, the yellow band. The GaN buffer surface roughness (between 10 and 14 nm, the rms value in a 10 × 10 μm(2) area) was low enough to allow the fabrication of a thin (7 nm thick) well defined Ti nanohole mask, for the selective area growth. Ordered In(Ga)N/GaN nanocolumns emitting from the ultraviolet (3.2 eV) to the infrared (0.78 eV) were obtained. The morphology and the emission efficiency of the In(Ga)N/GaN nanocolumns emitting at a given wavelength could be substantially improved by tuning the In/Ga and total III/N ratios. An estimated internal quantum efficiency of 36% was derived from photoluminescence data for green emitting nanocolumns.