Nanohybrids of reduced graphene oxide and cobalt hydroxide (Co(OH)2|rGO) for the thermal decomposition of ammonium perchlorate

The catalytic activity of nanoparticles of cobalt hydroxide supported on reduced graphene oxide, Co(OH)₂|rGO, was studied for the decomposition of ammonium perchlorate (AP), the principal ingredient of composite solid propellants. Co(OH)₂|rGO was synthesized by an in situ reduction method, which avoided the application of extremely high temperatures and harsh processes. rGO stabilized the nanoparticles effectively and prevented their agglomeration. The performance of Co(OH)₂|rGO as a catalyst was measured by differential scanning calorimetry. Co(OH)₂|rGO affected the high-temperature decomposition (HTD) of AP positively, decreasing the decomposition temperature of AP to 292 °C, and increasing the energy release to 290 J g⁻¹. The diminution of the HTD of AP by Co(OH)₂|rGO is in between the best values reported to date, suggesting its potential application as a catalyst for AP decomposition.

Cobalt hydroxide nanoparticles supported on reduced graphene oxide increased the energy release and lowered the decomposition temperature of ammonium perchlorate.     

Update on prehospital emergency care of severe trauma patients

The prognosis of severe trauma patients is determined by the ability of a healthcare system to provide high intensity therapeutic treatment on the field and to transport patients as quickly as possible to the structure best suited to their condition. Direct admission to a specialized center (“trauma center”) reduces the mortality of the most severe trauma at 30 days and one year. Triage in a non-specialized hospital is a major risk of loss of chance and should be avoided whenever possible. Medical dispatching plays a major role in determining patient care. The establishment of a hospital care network is an important issue that is not formalized enough in France. The initial triage of severe trauma patients must be improved to avoid taking patients to hospitals that are not equipped to take care of them. For this purpose, the MGAP score can predict severity and help decide where to transport the patient. However, it does not help predict the need for urgent resuscitation procedures. Hemodynamic management is central to the care of hemorrhagic shock and severe head trauma. Transport helicopter with a physician on board has an important role to allow direct admission to a specialized center in geographical areas that are difficult to access.     

Multicenter precision of cortical and trabecular bone quality measures assessed by high‐resolution peripheral quantitative computed tomography

High‐resolution peripheral quantitative computed tomography (HR‐pQCT) has recently been introduced as a clinical research tool for in vivo assessment of bone quality. The utility of this technology to address important skeletal health questions requires translation to standardized multicenter data pools. Our goal was to evaluate the feasibility of pooling data in multicenter HR‐pQCT imaging trials. Reproducibility imaging experiments were performed using structure and composition‐realistic phantoms constructed from cadaveric radii. Single‐center precision was determined by repeat scanning over short‐term (<72 hours), intermediate‐term (3–5 months), and long‐term intervals (28 months). Multicenter precision was determined by imaging the phantoms at nine different HR‐pQCT centers. Least significant change (LSC) and root mean squared coefficient of variation (RMSCV) for each interval and across centers was calculated for bone density, geometry, microstructure, and biomechanical parameters. Single‐center short‐term RMSCVs were <1% for all parameters except cortical thickness (Ct.Th) (1.1%), spatial variability in cortical thickness (Ct.Th.SD) (2.6%), standard deviation of trabecular separation (Tb.Sp.SD) (1.8%), and porosity measures (6% to 8%). Intermediate‐term RMSCVs were generally not statistically different from short‐term values. Long‐term variability was significantly greater for all density measures (0.7% to 2.0%; p < 0.05 versus short‐term) and several structure measures: cortical thickness (Ct.Th) (3.4%; p < 0.01 versus short‐term), cortical porosity (Ct.Po) (15.4%; p < 0.01 versus short‐term), and trabecular thickness (Tb.Th) (2.2%; p < 0.01 versus short‐term). Multicenter RMSCVs were also significantly higher than short‐term values: 2% to 4% for density and micro–finite element analysis (µFE) measures (p < 0.0001), 2.6% to 5.3% for morphometric measures (p < 0.001), whereas Ct.Po was 16.2% (p < 0.001). In the absence of subject motion, multicenter precision errors for HR‐pQCT parameters were generally less than 5%. Phantom‐based multicenter precision was comparable to previously reported in in vivo single‐center precision errors, although this was approximately two to five times worse than ex vivo short‐term precision. The data generated from this study will contribute to the future design and validation of standardized procedures that are broadly translatable to multicenter study designs. © 2013 American Society for Bone and Mineral Research.     

Update in the surgical principles and therapeutic outcomes of inguinal lymph node dissection for penile cancer

ObjectivesInguinal lymph node dissection (ILND) for the treatment of metastatic penile squamous cell carcinoma (SCC) has historically been associated with significant morbidity. This review addresses the surgical principles and techniques to decrease its perioperative morbidity, while optimizing its oncologic outcomes.Materials and methodsA review of the English scientific literature from 1966 to present was conducted using the PubMed search engine as well as of additional cited works not initially noted in the search using as keywords penile cancer, inguinal lymph node dissection, inguinal lymph node metastasis, morbidity, and complications.ResultsThe contemporary outcomes of ILND in the context of penile cancer have built on the significant contributions made by surgeons and scientists worldwide. In this review, we provide a comprehensive overview of the principles of ILND optimizing oncological outcomes, while minimizing its attributable morbidity. It is hoped this review will serve as a benchmark for clinicians to approach this often highly aggressive tumor phenotype.ConclusionsILND remains an important diagnostic and therapeutic procedure for patients with penile SCC, as contemporary ILND series have reported a decrease in its associated morbidity, with the potential for further treatment outcomes in years to come. ILND can in appropriately selected patients render them disease-free, thus justifying its associated morbidity.     

Age assessment based on dental calcification in individuals with Down syndrome

It is important to estimate both chronological age (CA) and maturational age of an individual, in order to perform orthopedic treatment or surgery, and in cases of lost documentation. Use of dental age (DA) for these purposes has been widely studied; however, the literature is scarce with regard to individuals with Down syndrome (DS), a prevalent condition worldwide. In this study the chronology of dental maturation was evaluated by analyzing the DA of individuals with DS based on the Chronological Mineralization Table proposed by Nolla (1960). Thus, second molars were evaluated in 57 panoramic radiographs of male and female individuals with DS, between 5 and 16 years-old. These data were compared with a control group of 191 nonsyndromic individuals of the same age group. Correlation between CA and DA was ascertained using Pearson's correlation coefficient (r), and the difference between these variables was measured using Student's t-test for paired samples and the method proposed by Bland and Altman. The difference between DA and CA was compared between the control and DS groups using Student's t-test for independent samples (α = 0.05). DA was slightly lower than the CA; however, this difference was only significant for females. The difference between DA and CA was not significant between individuals with DS and control group (both genders, p = 0.945; males, p = 0.542; females, p = 0.381). We concluded that dental maturation in individuals with DS occurs similarly to that of nonsyndromic individuals.     

Inequality in pediatric kidney transplantation in Brazil

Background

The aim of this study was to describe the access and factors associated with kidney transplantation for children in different regions of Brazil.

Methods

We analyzed a cohort of 1211 children enrolled on the transplant list from January 2011 to December of 2013. We fitted regression models to investigate factors associated with: (a) undergoing kidney transplantation from a deceased donor, and (b) being removed from the waiting list.

Results

The incidence of transplantation was uneven across regions, with the lowest rate at 0.4 per million age-related population (pmarp) in the Midwest and the highest incidence rate of 8.3 cases pmarp in the South. Children from the North and the Midwest regions had a 3–4 times lower probability of undergoing a deceased donor transplant (p < 0.05). Apart from the geographic region, age of recipients and GDP influenced the outcome. The likelihood of undergoing transplantation was very low in the youngest children in the North and Midwest. The number of transplant centers was not associated with either outcome.

Conclusions

Factors of inequality in transplantation in Brazil are of macroeconomic origin, but there is room to reduce inequalities. Training existing transplant center professionals in the care of children could diminish the discrepancies.

     

Spinal metallosis: a systematic review

Purpose

To document a rarely reported complication associated with spinal instrumentation and to evaluate the current literature on spinal metallosis and spinal metalloma.

Methods

A local case report is presented. EBSCOhost, PubMed and ScienceDirect databases were used to conduct a systematic review for articles describing spinal metallosis and spinal metalloma.

Results

A total of 836 articles were identified using the terms “metalloma” or “metallosis”. Exclusion of arthroplasty-related abstracts retrieved 46 articles of which 3 full text articles presenting spinal metalloma as a causative pathological finding responsible for neurological signs and symptoms in patients with previous spinal fusion instrumentation were reviewed. Our case is the first described with titanium-composed posterior instrumentation and fifth reported, demonstrating the phenomena of neurological symptoms and signs attributed directly to neural tissue compression by spinal metalloma after spinal instrumentation.

Conclusion

Spinal metallosis can present weeks to years after spinal instrumentation surgery and is a potential cause of neural compression. This process appears to be independent of the instrument composition as metallosis has now been demonstrated in both titanium and stainless steel constructs.