Promoting formic acid oxidation performance of Pd nanoparticles via Pt and Ru atom mediated surface engineering

The alteration of surface functional properties via incorporation of foreign atoms is supposed to be a key strategy for the enhanced catalytic performance of noble-metal based nanocatalysts (NCs). In the present study, carbon-supported palladium (Pd)-based NCs including Pd, PdPt and PdRuPt have been prepared via a polyol reduction method under the same reduction conditions as for formic acid oxidation reaction (FAOR) applications. By cross-referencing the results of the microscopic, spectroscopic and electrochemical analysis we demonstrated that adding a small amount of platinum (Pt) into Pd NCs (i.e. PdPt NCs) significantly promotes the FAOR performance as compared to that of Pd NCs via weakening the CO^ads bond strength at a lower voltage (0.875 V vs. NHE) than Pd (0.891 V vs. NHE). Of special relevance, the PdPt NC shows a mass activity (MA) of 1.0 A mg⁻¹ and 1.9 A mg⁻¹, respectively, in the anodic and cathodic scan. These values are ∼1.7-fold (0.6 A mg⁻¹) and ∼4.8-fold (0.4 A mg⁻¹) higher than those of Pd NC. Moreover, PdPt NC retains a higher MA (54 mA mg⁻¹) than that of Pd NC (9 mA mg⁻¹) after chronoamperometric (CA) stability tests over 2000 s. Meanwhile, further addition of ruthenium (Ru) (i.e. PdRuPt NCs) outstandingly enhances the CO tolerance during the CA test via removal of adsorbed CO^ads and thus shows the highest MA (62 mA mg⁻¹) after CA testing, which is higher than that of PdPt (54 mA mg⁻¹) and Pd (9 mA mg⁻¹) NCs. The intriguing results obtained in this study have great significance to provide further strategic opportunities for tuning the surface electronic properties of Pd-based NCs to design Pd-based NCs with improved electrochemical performance.

Pt atoms attract electrons from neighboring atoms. Ru atoms attract hydroxide ligands. These two characteristics respectively weaken the bonding and recovering of the Pt site from CO oxidation and then facilitate the FAO in ternary PdPtRu NCs.     

Does retinal vascular geometry vary with cardiac cycle?

Purpose. Changes in retinal vascular parameters have been shown to be associated with systemic vascular diseases. In this study, we assessed the physiologic variations in retinal vascular measurements during the cardiac cycle. Methods. Fundus images were taken using electrocardiogram-synchronized retinal camera at nine distinct cardiac points from 15 healthy volunteers (135 images). Analyses of retinal vessel geometric measures, including retinal vessel caliber (individual and summary), tortuosity, branching angle, length-diameter ratio (LDR), and optimality deviation, were performed using semiautomated computer software. Repeated-measures ANOVAs were used to obtain the means and to estimate the variation of each cardiac point compared with cardiac point 1. Results. There was a significant variation of the caliber of the individual arteriolar and venular vessels. However, there was no significant variation found for vessel caliber summary, represented by the central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE). There was also no significant variation found for tortuosity and branching angle, and LDR showed none or very little variations at different cardiac points: variations in caliber ranges between 0 and 4.1%, tortuosity 0 and 1.5%, branching angle 0 and 3.5%, and LDR 0 and 2%; all values for variations, P > 0.1; linear trend, P > 0.5; and nonlinear trend, P > 0.8. Conclusions. This study showed that there were minimal variations in the CRAE, CRVE, tortuosity, and branching angle that are clinically used for two-dimensional measures of retinal vascular geometry during cardiac cycles. However, there was significant variation in the caliber of the individual vessels over the cardiac cycle.     

甲状腺相关性眼病伴眼外肌肌腱受累1例

目的：报告1例甲状腺相关性眼病的非典型CT扫描表现。方法：一位64岁的中国女性出现复视3mo,无视力模糊。14a前她曾患甲状腺功能亢进症伴多结节甲状腺肿并行甲状腺切除术。眼科检查发现双眼下斜视并向上注视受限。左眼red desaturation并Ⅰ级相对性瞳孔传入障碍。T3,T4和促甲状腺激素（thyroid stimulating hormone,TSH）正常。TSH受体、抗体水平高,与Graves＇病一致。磁共振成像（magnetic resonance imaging,MRI）显示双下直肌弥漫性增大,肌腱受累。结果：给予几周期静脉注射甲基强的松龙继之以口服强的松后视力无提高,反之继续下降。行左眼眼眶减压术,术后其左眼视力有所改善。结论：有肌腱受累的眼外肌增大不能排除甲状腺相关性眼眶病（thyroid assciated orbitopathy,TAO）的可能。     

Focal knee resurfacing

A significant number of patients suffer from focal articular damage that is neither appropriate for traditional arthroplasty, nor for biological repair. Since 2005, contoured focal resurfacing systems for the femoral condyle have been available that can cater for this specific subgroup of patients. Independent long-term data on these implants have previously been lacking, but are now becoming available. This review will look at: the basic biology of cartilage, the natural progression of focal cartilage disease in the knee, the surgical and non-surgical options available, the indications for focal resurfacing, surgical techniques, which implants are currently available, and the current clinical data with respect to these.     

Treatment of acute gout: A systematic review

Objective

Acute gout is traditionally treated with NSAIDs, corticosteroids, and colchicine; however, subjects have multiple comorbidities that limit the use of some conventional therapies. We systematically reviewed the published data on the pharmacologic and non-pharmacologic agents used for the treatment of acute gouty arthritis.

Methods

A systematic search was performed using PubMed and Cochrane database through May 2013. We included only randomized controlled trials (RCTs) that included NSAIDs, corticosteroids, colchicine, adrenocorticotropic hormone (ACTH), interleukin-1 (IL-1) inhibitors, topical ice, or herbal supplements.

Results

Thirty articles were selected for systematic review. The results show that NSAIDs and COX-2 inhibitors are effective agents for the treatment of acute gout attacks. Systemic corticosteroids have similar efficacy to therapeutic doses of NSAIDs, with studies supporting oral and intramuscular use. ACTH is suggested to be efficacious in acute gout. Oral colchicine demonstrated to be effective, with low-dose colchicine demonstrating a comparable tolerability profile as placebo and a significantly lower side effect profile to high-dose colchicine. The IL-1β inhibitory antibody, canakinumab, was effective for the treatment of acute attacks in subjects refractory to and in those with contraindications to NSAIDs and/or colchicine. However, rilonacept was demonstrated to be not as effective, and there are no RCTs for the use of anakinra.

Conclusion

NSAIDs, COX-2 selective inhibitors, corticosteroids, colchicine, ACTH, and canakinumab have evidence to suggest efficacy in treatment of acute gout.     

Prevalence of Hypertension in Member Countries of South Asian Association for Regional Cooperation (SAARC): Systematic Review and Meta-Analysis

Hypertension is a leading attributable risk factor for mortality in South Asia. However, a systematic review on prevalence and risk factors for hypertension in the region of the South Asian Association for Regional Cooperation (SAARC) has not carried out before.The study was conducted according to the Meta-Analysis of Observational Studies in Epidemiology Guideline. A literature search was performed with a combination of medical subject headings terms, “hypertension” and “Epidemiology/EP”. The search was supplemented by cross-references. Thirty-three publications that met the inclusion criteria were included in the synthesis and meta-analyses. Hypertension is defined when an individual had a systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg, was taking antihypertensive drugs, or had previously been diagnosed as hypertensive by health care professionals. Prehypertension is defined as SBP 120–139 mm Hg and DBP 80–89 mm Hg.The overall prevalence of hypertension and prehypertension from the studies was found to be 27% and 29.6%, respectively. Hypertension varied between the studies, which ranged from 13.6% to 47.9% and was found to be higher in the studies conducted in urban areas than in rural areas. The prevalence of hypertension from the latest studies was: Bangladesh: 17.9%; Bhutan: 23.9%; India: 31.4%; Maldives: 31.5%; Nepal: 33.8%; Pakistan: 25%; and Sri Lanka: 20.9%. Eight out of 19 studies with information about prevalence of hypertension in both sexes showed that the prevalence was higher among women than men. Meta-analyses showed that sex (men: odds ratio [OR] 1.19; 95% confidence interval [CI]: 1.02, 1.37), obesity (OR 2.33; 95% CI: 1.87, 2.78), and central obesity (OR 2.16; 95% CI: 1.37, 2.95) were associated with hypertension.Our study found a variable prevalence of hypertension across SAARC countries, with a number of countries with blood pressure above the global average. We also noted that studies are not consistent in their data collection about hypertension and related modifiable risk factors.     

Implant Retained Auricular Prosthesis with a Modified Hader Bar: A Case Report

Auricular prostheses for defects of external ear are retained either by mechanical means or implants. All implant retained prostheses are retained by various means such as bar and clip, magnetic attachments or a combination of bar, clip and magnets. The commonest problem encountered with the bar and clip system is loosening of the clip after 3–4 months. When magnets are used as retaining component they tend to corrode over a period of time. So various alternative retention methods which possess good retentive qualities, ease of reparability and patient friendly were tried. In the present case a newly modified Hader bar design which can act as an additional retentive feature apart from the clip is employed to increase retention. The major advantages in the modified Hader bar system were that only two implants were employed, the additional loops in the Hader bar prevented micro movements and the retentive acrylic locks were easy to repair if broken. The modified Hader bar has anti-rotational slots which prevents the sliding or rotation of the prosthesis which gave new confidence to the patient who was otherwise worried of inadvertent displacement of the ear prosthesis while playing.