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This work describes exploration of mitigating the parasitic amorphous alumina (Al2O3) shell of aluminum nanoparticles (n-Al) and modifying the surface using different plasmas, leading to n-Al with thinner shell and different coatings including carbons and oxidizing salt called aluminum iodate hexahydrate (AIH), respectively. The approach exploits a prototype atmospheric non-thermal plasma reactor with dielectric barrier discharge (DBD) configuration for nanoparticle surface modifications using n-Al of 80 nm average diameter as an example. Preliminary results indicate that the amorphous Al2O3 shell surrounding the active aluminum core can be mitigated with inert plasmas by as much as 40% using either helium (He) or argon (Ar). The particle surface becomes carbon-rich with carbon monoxide (CO) / He plasmas. By immersing the plasma-treated n-Al in an iodic acid (HIO3) solution, AIH crystals can be formed on the n-Al surface. Transmission electron microscopy (TEM) is used as a major tool to study the details of the modified surface morphologies, diffraction patterns, and chemical composition of the modified n-Al. The results demonstrate effective surface passivation of n-Al via atmospheric plasma techniques.
A transannular patch is often used in the contemporary surgical repair of tetralogy of Fallot. This can lead to significant pulmonary insufficiency and increased right ventricular volumes and ultimately pulmonary valve replacement. Cardiopulmonary exercise testing is used to assess exercise capacity in tetralogy of Fallot patients before pulmonary valve replacement. There is only few published literatures on how lung function affects functional capacity in tetralogy of Fallot patients repaired with a transannular patch.
A retrospective chart review was done from 2015 to 2017 on patients with tetralogy of Fallot who underwent maximal effort cardiopulmonary exercise testing with cycle ergometry and with concurrent pulmonary function testing. Tetralogy of Fallot patients repaired with a transannular patch without pulmonary valve replacement were compared with age, gender, and size-matched normal controls.
In the tetralogy of Fallot group, 24 out of 57 patients underwent primary repair with a transannular patch. When compared to the normal controls, they demonstrated abnormal predicted forced expiratory volume in one second (79 ± 23.1% versus 90.7 ± 14.1%, p<0.05), predicted maximal voluntary ventilation (74 ± 18% versus 90.5 ± 16.2%, p<0.05) while having low-normal predicted forced vital capacity (80.5 ± 17.2% versus 90.2 ± 12.4%, p<0.05) and normal breathing reserve percentage (50.3 ± 11.3% versus 47.5 ± 17.3%, p = 0.52). Cardiopulmonary exercise testing abnormalities included significantly lower percent predicted oxygen consumption (63.2 ± 12.2% versus 87 ± 12.1%, p<0.05), maximal heart rate (171.8 ± 18.9 versus 184.6 ± 13.6, p<0.05), and percent predicted maximum workload (61.7 ± 15.9% versus 88.3 ± 21.5%, p<0.05).
Tetralogy of Fallot patients repaired with a transannular patch can have abnormal pulmonary function testing with poor exercise capacity in addition to chronotropic incompetence and impaired muscular power.
An investigation of the effect of experimental parameters on the temperature and uniformity of material deposition by atmospheric pressure dielectric barrier discharge (DBD) planar plasma reactors was conducted. The apparatus consisted of a pulsed AC high voltage power source with various electrode materials (aluminum, copper wire mesh, and aluminum/copper wire mesh) operating under a range of load resistances. Possible effects of non-ideal interfacial conditions for the contact surface between the electrode and the substrate were also studied with various modified surface thermal conditions. It was found that a hybrid electrode design with a fine copper (Cu) wire mesh attached to an aluminum plate of approximately 3 mm thickness produced the most visually uniform deposit, presumably as a result of both the superior conductivity provided by the Al metal plate and the stable plasma resulting from the relatively low breakdown voltage by using helium (He) as the dilution gas. Although the experimental conditions of plasma-enhanced chemical vapor deposition (PECVD) are often specific to particular systems and applications, this work provides insights on technical details which can be applied to various plasma DBD reactors.
The current study examined whether consistency in day-to-day interactions between children and parents related to inflammatory cytokine production in youths. One hundred twenty-three parents recorded the daily quality of interactions and timing of leisure activities with their adolescent children for 2 weeks, and the degree of variability in those ratings was calculated. One year later, the production of proinflammatory cytokines in youths’ blood was measured in response to in vitro exposure to lipopolysaccharide (a bacterial product). The results indicate that greater variability in parent–child relationship quality related to greater stimulated proinflammatory cytokine production in youths, above and beyond overall relationship quality. Greater variability in the timing of parent–child leisure activities also predicted greater stimulated proinflammatory cytokine production in youths, regardless of the frequency of interactions. In sum, consistency in both the affective and temporal aspects of parent–child relationships may contribute to inflammatory processes in youth.
This work reports the fabrication and characterization of superstrate-type Zn1-xMgxO/CdTe heterojunction solar cells on both CdxSnyO and commercial SnO2:F transparent conducting oxides (TCOs) in which the ZMO and CTO layers are produced for the first time by hollow cathode sputtering. The sputtering is conducted in a reactive mode using metal or alloyed metal targets fitted to a custom-made linear cathode. It is notable that the CdS buffer layer conventionally employed in CdTe solar cells is entirely replaced by the ZMO window layer. The use of ZMO is found to eliminate the blue loss associated with CdS optical absorption and further results in a higher open-circuit voltage. Key parameters were found to be the conduction band offset at the ZMO/CdTe interface and the ZMO thickness. It was discovered that the ZMO exhibits intense photoluminescence even at room temperature. Most of the solar cells were fabricated in the FTO/ZMO/CdTe configuration although CTO/ZMO/CdTe solar cells were also demonstrated. The CTO was produced with an electron mobility of 46 cm2 V-1s-1 without any post-deposition annealing or treatment.
Introduction: The CJEM Social Media Team was created in 2014 to assist the journal with the dissemination of its research online. It consists of two Social Media Editors (Junior and Senior) and a team of volunteer medical students and residents to assist their work. Collaborative promotional agreements were developed to promote CJEM articles on the Skeptics’ Guide to Emergency Medicine (SGEM) podcast through the ‘Hot off the Press’ (HOP) series and the CanadiEM blog through an infographic series. Methods:CJEM papers were selected for promotion by the Team based on their perceived interest to the online community of emergency physicians. Altmetric scores, which are a measure of online dissemination derived from a weighted algorithm of social media metrics, were collated for articles promoted using the SGEM HOP or CanadiEM blogs. A control group was created using the articles with the top two Altmetric scores in each CJEM issue in 2015 and 2016. Erratum, Letters, and articles written by the social media editors were excluded from the control groups. The success of the social media promotion was quantified through the measurement of Altmetric scores as of January 1, 2017. Unpaired two-tailed t-tests with unequal variance were used to test for significant differences. Results: 106 and 82 eligible articles were published in 2015 and 2016, respectively. Four articles in 2015 and two articles in 2016 were excluded from the control groups because they were written by the social media editors. SGEM HOP podcasts promoted one article in 2015 and five articles in 2016. CanadiEM infographics promoted three articles in 2015 and eight articles in 2016. No articles were promoted in both series. The average Altmetric score was higher for SGEM HOP (61.0) than CanadiEM Infographics (31.5, p<0.04), 2015 controls (15.8, p<0.01), and 2016 controls (13.6, p<0.01). The average Altmetric score for CanadiEM Infographics was higher than 2015 controls (p<0.04) and 2016 controls (p<0.02). There was no significant difference between the control groups. Conclusion: The results suggest that collaborating with established social media websites to promote CJEM articles using podcasts and infographics increases their social media dissemination. Given the nonrandomized design of these results, causative conclusions cannot be drawn. A randomized study of the impact of social media promotion on readership is underway.
Introduction: Podcasts and blog posts are gaining popularity in Free Open Access Medical education (FOAMed). However, there remains a paucity of research comparing the two media for undergraduate medical education. This study aims to investigate if there are differences in medical students’ usage conditions, knowledge retention and preferences in the two types of media (podcasts, blog posts). Methods: Medical students were block-randomized to either the podcast or blog post group according to their year of schooling. They completed an online assessment of their baseline knowledge on the subject matter and preferences within the various types of media. Participants then received access to learning materials and were given four weeks to complete the follow-up assessment. Simple descriptive statistical data were used to detail student preferences. Paired samples t-tests and a Repeated Measures Analysis of Variance (RM-ANOVA) were conducted to assess knowledge acquisition. A carry forward analysis was used to impute missing data from students lost to follow-up. Results: A total of 65 medical students participated in our study (podcasts n=33, blog posts n=32). The initial survey suggests that students prefer general topic discussion and “approach-to” themes (68% and 84%, respectively). 55% of students in the podcast group preferred podcasts that were less than 30 minutes. None of the blog post group preferred a shorter text, and each blog post required a mean of 25 minutes to read. Completion of at least one follow-up assessment was comparable (68% podcasts, 70% blog posts). The podcast listeners tended to engage in multiple activities while using the learning material (e.g. at least 2-3 of the following: driving, eating, chores, taking notes, exercising), while the blog readers tended to do fewer activities (e.g. only 1 of the following: taking notes, eating, only reading). Both groups showed significant improvements in their test scores (Asthma: 22% improvement, Toxicology: 29%; p<0.01 for both), with blog posts demonstrating a larger but non-significant difference (RM-ANOVA, Topic*Modality F(1,59)=0.001, p=0.973). Conclusion: This study suggests that podcasts and blog posts significantly improve medical student knowledge retention to a similar degree, but differ in usage conditions.
Fontan survivors have depressed cardiac index that worsens over time. Serum biomarker measurement is minimally invasive, rapid, widely available, and may be useful for serial monitoring. The purpose of this study was to identify biomarkers that correlate with lower cardiac index in Fontan patients.
Methods and results
This study was a multi-centre case series assessing the correlations between biomarkers and cardiac magnetic resonance-derived cardiac index in Fontan patients ⩾6 years of age with biochemical and haematopoietic biomarkers obtained ±12 months from cardiac magnetic resonance. Medical history and biomarker values were obtained by chart review. Spearman’s Rank correlation assessed associations between biomarker z-scores and cardiac index. Biomarkers with significant correlations had receiver operating characteristic curves and area under the curve estimated. In total, 97 cardiac magnetic resonances in 87 patients met inclusion criteria: median age at cardiac magnetic resonance was 15 (6–33) years. Significant correlations were found between cardiac index and total alkaline phosphatase (−0.26, p=0.04), estimated creatinine clearance (0.26, p=0.02), and mean corpuscular volume (−0.32, p<0.01). Area under the curve for the three individual biomarkers was 0.63–0.69. Area under the curve for the three-biomarker panel was 0.75. Comparison of cardiac index above and below the receiver operating characteristic curve-identified cut-off points revealed significant differences for each biomarker (p<0.01) and for the composite panel [median cardiac index for higher-risk group=2.17 L/minute/m2 versus lower-risk group=2.96 L/minute/m2, (p<0.01)].
Higher total alkaline phosphatase and mean corpuscular volume as well as lower estimated creatinine clearance identify Fontan patients with lower cardiac index. Using biomarkers to monitor haemodynamics and organ-specific effects warrants prospective investigation.
In otolaryngology, surgical emergencies can occur at any time. An annual surgical training camp (or ‘boot camp’) offers junior residents from across North America the opportunity to learn and practice these skills in a safe environment. The goals of this study were to describe the set-up and execution of a simulation-based otolaryngology boot camp and to determine participants' confidence in performing routine and emergency on-call procedures in stressful situations before and after the boot camp.
There were three main components of the boot camp: task trainers, simulations and an interactive panel discussion. Surveys were given to participants before and after the boot camp, and their confidence in performing the different tasks was assessed via multiple t-tests.
Participants comprised 22 residents from 12 different universities; 10 of these completed both boot camp surveys. Of the nine tasks, the residents reported a significant improvement in confidence levels for six, including surgical airway and orbital haematoma management.
An otolaryngology boot camp gives residents the chance to learn and practice emergency skills before encountering the emergencies in everyday practice. Their confidence in multiple skillsets was significantly improved after the boot camp. Given the shift towards competency-based learning in medical training, this study has implications for all surgical and procedural specialties.
The aim of the present study was to report the survival outcomes and late toxicity of high-dose-rate brachytherapy (HDRBT) boost for dose escalation in patients with intermediate-to-high-risk prostate cancer.
Materials and methods
Retrospective data were collected from 137 patients who had undergone definitive radiotherapy for prostate cancer between 2006 and 2010. All patients had external-beam radiotherapy (median dose 46Gy) and HDRBT. Brachytherapy dose was 19Gy in two fractions (6 hours apart) with one implant using Ir-192.
There were 94 high-risk and 43 intermediate-risk patients (NCCN classification). The median follow-up period was 60 months. The 5-year biochemical progression-free survival was 92 and 76% for intermediate- and high-risk groups, respectively. Prostate cancer-specific survival for the intermediate-risk group was 100% and for the high-risk group it was 92% at 5 years. For the entire cohort, the 5-year rate of urethral stricture formation was 13%, and the 5-year rate of late grade 2 and grade 3 gastrointestinal toxicity was 4·7 and 4·6%, respectively. There was no grade 3 or greater genitourinary toxicity.
Our data add to the growing body of literature supporting the use of HDRBT in prostate cancer. Late toxicity rates were marginally higher than that expected.
We examined developmental programming studies that reported sex-specific effects published between 2012 and 2014, and examined whether the authors reported a statistical approach to explicitly test whether the effect of treatment differed between the sexes, for example, a sex by treatment interaction term. Less than half of the studies that reported sex-specific effects described explicitly testing whether effects were indeed sex-specific; in most cases, an effect was considered ‘sex-specific’ if it was significant in one sex but not the other. This is not a robust approach, since significance in one sex and lack of significance in the other sex does not imply a significant difference between the sexes. However, sample size often limits statistical power to detect interactions. We suggest that if the effect is significant in only one sex, but the interaction term is not significant, alternative solutions would be to present the confidence intervals for the effect size for each sex, or using Bayesian approaches to calculate the probability that the effect sizes differ between the sexes. We present a simple example of a Bayesian analysis to illustrate that this approach is reasonably easy to implement and interpret.
Nasolacrimal duct obstruction is common and is usually a result of benign stricture formation. Although neoplasia near or around the lacrimal system may produce epiphora, the incidence of neoplasia from within the lacrimal system as a cause of nasolacrimal duct obstruction is not well documented.
A retrospective study was performed on all patients undergoing dacryocystorhinostomy with a history of epiphora. The incidence of patients with operative findings of intra-lacrimal neoplasm was sought. Histopathologically confirmed cases were included.
The study comprised 537 patients, who underwent a total of 631 endoscopic dacryocystorhinostomy procedures between January 1998 and July 2013. Non-stenotic causes of nasolacrimal duct obstruction were encountered in 3.01 per cent of dacryocystorhinostomy procedures, and included neoplastic, inflammatory and infectious pathologies. Inverted papilloma was the most common cause, encountered in 0.79 per cent of dacryocystorhinostomy operations.
These findings suggest that neoplasia is an uncommon but not a rare cause of nasolacrimal duct obstruction. Surgical teams performing high numbers of dacryocystorhinostomy procedures should be aware of such pathology and patients counselled appropriately.
The effects of alloying elements (Ni/Ta) on the temperature dependence of yield stress in Co3(Al,W) with the L12 structure have been investigated through compression tests of nearly single-phase polycrystalline alloys in the temperature range between room temperature to 1,473K. Compared with a ternary Co3(Al,W), a Ni/Ta-added Co3(Al,W) alloy exhibits a higher γ΄ solvus temperature and lower onset temperature of the yield stress anomaly (positive temperature dependence of yield stress), suggesting that the CSF energy is increased by Ni/Ta addition. As a consequence, the high-temperature strength in Co3(Al,W) is considerably enhanced.
A radio-frequency magnetron sputtering technique and subsequent rapid thermal annealing (RTA) at 600, 700, 800, and 900 °C were implemented to grow high-quality Ga-doped MgxZn1-xO (GMZO) epi-layers. The GMZO films were deposited using a radio-frequency magnetron sputtering system and a 4 inch ZnO/MgO/Ga2O3 (75/20/5 wt %) target. The Hall results, X-ray diffraction (XRD), and transmittance were determined and are reported in this paper. The Hall results indicated that the increase in mobility was likely caused by the improved crystallization in the GMZO films after thermal annealing. The XRD results revealed that MgxZn1-xO (111) and MgO2 (200) peaks were obtained in the GMZO films. The absorption edges of the as-grown and annealed GMZO films shifted toward the short wavelength of 373 nm at a transmittance of 90%. According to these results, GMZO films are feasible for forming transparent contact layers for near-ultraviolet light-emitting diodes.
Carbon/carbon composites (C/C composites) possess superior characteristics of low density, high strength, extremely low coefficient of thermal expansion, high fatigue resistance. In carbonization process, the high temperature pyrolysis made of carbon, hydrogen, oxygen and other elements, results in a lot of voids and cavities generated in the interior of C/C composites. Therefore, the C/C composites are densified to fill the void by using repeated impregnation. But densification is a time-wasting and complex process, which increases production costs in the manufacturing process.
In this study, the Multi-Wall Carbon Nanotubes (MWNTs) were adopted as reinforcement material for C/C composites to reduce the existence of voids or cavities and enhance the mechanical properties of C/C composites under environment aging effects. Three different temperature with high moisture conditions are used to be tested, including high temperature (150°C/ 90%RH), room temperature (25°C/90%RH), and low temperature (-15°C/90%RH) to analyze the mechanical properties of C/C composites, such as flexural and Interlaminar Shear Strength (ILSS).
Effective tissue removal techniques are essential in endoscopic skull base surgery. Improvements in technology permit more accurate application of CO2 laser and coblation during endonasal procedures. This study assessed the thermal injury patterns associated with fibre CO2 laser and coblation.
Fresh frozen cadaveric heads were used. Mucosal removal was performed at the ethmoid roof. Structured lesions were created using either CO2 laser or coblation. The corresponding thermal injury patterns on dural tissue were assessed and compared between the two groups.
Five cadaveric heads were obtained; five sides received CO2 laser lesions and five coblation lesions. Forty per cent (n = two sides) of the CO2 specimens had macroscopic foci of grey-black discolouration on the dural aspect. No macroscopic dural changes were seen in the coblation specimens.
Dural injury was seen following CO2 laser use despite attempts to avoid it. Both CO2 laser and coblation have their advantages; however, the lower thermal working power of coblation and superior depth control may make it more suitable for endoscopic endonasal periorbital and peridural surgery.