Pencil Graphite Electrodes Decorated with Platinum Nanoparticles as Efficient Electrocatalysts for Hydrogen Evolution Reaction

Platinum-based materials are widely known as the most utilized and advanced catalysts for hydrogen evolution reaction. For this reason, several studies have reported alternative methods of incorporating this metal into more economical electrodes with a carbon-based support material. Herein, we report on the performance of pencil graphite electrodes decorated with electrochemically deposited platinum nanoparticles as efficient electrocatalysts for hydrogen evolution reaction. The electrodeposition of platinum was performed via pulsed current electrodeposition and the effect of current density on the electrocatalytic activity was investigated. The obtained electrodes were characterized using cyclic voltammetry, while the electrocatalytic activity was assessed through linear sweep voltammetry. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were utilised to gain an insight into surface morphology and chemical analysis of platinum nanoparticles. The best performing electrocatalyst, at both low and high current densities, was characterized by the highest exchange current density of 1.98 mA cm⁻² and an ultralow overpotential of 43 mV at a current density of 10 mA cm⁻². The results show that, at low current densities, performances closest to that of platinum can be achieved even with an ultralow loading of 50 µg cm⁻² Pt.     

Probability rates for different pregnancy outcomes in carriers of reciprocal chromosomal translocations involving chromosome 13

OBJECTIVES: The aim of study was to estimate the probability rates for unfavorable pregnancy outcomes in carriers of reciprocal chromosomal translocations involving 13 chromosome (RCT-13q). MATERIAL AND METHODS: We collected total empirical data about 232 pregnancies of 56 carriers coming from 28 pedigrees. RCT classification was based on classic cytogenetic methods for interpretation of breakpoint position. The probability rates of particular type of pathology related to the total number of pregnancies after ascertainment correction have been calculated with the help of Stengel-Rutkowski and Stene method. RESULTS: The risk figures for unbalanced offspring after 2:2 disjunction and adjacent-1 segregation for the whole group of pedigrees were calculated as 5.2 +/- 1.7% (9/173)--medium risk, for maternal (MAT) and paternal (PAT) carriers were about 6.2 +/- 2.3% (7/173) and 4.8 +/- 3.3% (2/42) respectively. Considering different segment lengths of 13q, similar values for shorter and longer segments were obtained [4.3 +/- 1.9% (5/115) for 13q21-->qter and 7.0 +/- 3.3% (4/58) for 13q12-->qter]. The risk figures for miscarriages as 36.4 +/-3.6% (63/173) and for stillbirths/early death as 4.6 +/- 31.6% (8/173) were obtained. The risk figures for unbalanced offspring after 3:1 disjunction were calculated as 7.7 +/- 7.45 (9/13). Conclusions: 1. Risk figures for different pregnancy outcomes are differ among particular forms of pathology. 2. Probability rate for unbalanced progeny at birth was calculated as a medium risk and similar values for carriers of different segments of 13q were obtained. 3. Probability rate for miscarriages was high but risk for stillbirths/early deaths of newborn was low. 4. No differences in values of rate for particular forms of pathology were found for maternal and paternal carriers of RCT-13q.     

Urodynamic studies before and after retropubic colpo-urethrocystopexy in fertile women with stress urinary incontinence

Summary We compared urodynamic parameters in a group of 30 healthy women of fertile age, before and after primary retropubic colpo-urethrocystopexy carried out to correct genuine stress urinary incontinence. The mean interval between surgical treatment and follow-up was 38.0 (SD 10.2) months. In 26 women, subjectively and objectively cured at follow-up, we found an increase of 5.1 mm in functional length of the urethra (t=4.5;P<0.001), an increase of 12.3 cm H₂O in the urethral closure pressure (t=3.9;P<0.001), and a 22.1% increase in the transmission ratio (t=3.2;P<0.01). However, 9 of these 26 women satisfied with the results of the surgical treatment showed a drop in at least 2 of the parameters studied. In the group of 4 women not satisfied with the results of the surgical treatment we found an improvement in all of the urodynamic parameters studied, similar to those found in the group of satisfied women, though less pronounced. This study indicates that successful surgical treatment of genuine stress urinary incontinence is not related to surgically induced changes in the urodynamic parameters.     

Medio-thoracic esophageal stenosis,produced by pseudotumoral ulcer

A non-specific esophagitis developed in a young male, apparently determined by heavy abuse of alcohol. Shortly after, a stenotic pseudo-tumoral mediothoracic esophageal lesion was diagnosed. Although there was a high index of suspicion regarding the caustic origin of the lesion, cancer could not be excluded using current diagnostic methods. Temporary feeding jejunostomy was followed by uneventful total esophagectomy and gastric pull-up. Pathologic examination of the resected specimen was a surprise, revealing an esophageal ulcer based on massive severe non-specific esophagitis. Retrospectively, the ulcer was judged as primitive or idiopathic. We discuss some etiopathogenic aspects of common secondary esophageal ulcers (related or not to reflux disease), in contrast with idiopathic esophageal ulcers.     

Laser ‘miniconisation’ and the outcome of subsequent pregnancy

We routinely use the carbon dioxide laser miniconisation procedure for cervical interepithelial neoplasia 1–111. A retrospective case control study was conducted in 1,485 miniconised women during 250 subsequent pregnancies (including three twin pregnancies). The analysis showed that the miniconised subjects had no significant pregnancy complications and the same preterm birth ratio (8.0%) as controls matched for age and parity.     

Subjective sleep complaints in pediatric depression: a controlled study and comparison with EEG measures of sleep and waking

OBJECTIVE: Children with major depressive disorder (MDD) often complain of sleep disturbances; however, polysomnographic studies have failed to find objective evidence of these disturbances. This article examines subjective sleep reports of children with MDD and healthy controls focusing on comparing subjective and objective sleep measures. METHOD: Fifty-one subjects with MDD and 42 healthy subjects, 8-17 years old, participated in a comprehensive psychobiologic study including three nights of EEG sleep recording. Each morning, subjects completed a post-sleep form subjectively rating their sleep, which was then compared with their polysomnographic studies. RESULTS: Depressed subjects reported significantly worse sleep on four scales: subjective sleep quality, perceived number of awakenings, estimated minutes awake, and perceived ease of waking. In contrast to these subjective complaints, objective EEG measures indicated no evidence of disturbed sleep in the depressed sample compared to controls. Furthermore, exploratory analyses focusing on the subset of depressed subjects with the greatest subjective sleep disturbance showed, paradoxically, significantly better sleep in terms of the number of EEG awakenings and objective disturbances. CONCLUSIONS: Despite clinical evidence of subjective sleep complaints in depressed children, our EEG measures showed little evidence to indicate an objective basis for these perceptions. These findings raise provocative questions regarding the nature of sleep complaints associated with early-onset depression.     

Ectopic intestinal varices in cirrhotic patients; an infrequent cause of severe intestinal bleeding

We report on a cirrhotic patient, with history of colecistectomy, admitted for acute digestive bleeding. Esogastric causes were excluded by endoscopy; due to continuous hemorrhage, the patient was operated in the next 20 hours. The cause was established during the operation; solitary omfalo-enteric varices, with active vascular fistula. Preoperative etiology of acute intestinal bleeding may be difficult to establish, sometimes even during the surgical intervention. We comment upon rare causes of acute intestinal bleeding, mainly ectopic varices determined by portal hypertension.     

Urodynamic studies of women with prolapse and stress incontinence before and after surgical repair

Twenty-one women, 11 suffering from both prolapse and stress incontinence and 10 with prolapse only were investigated before and at different intervals after surgical repair of the disorders. The investigations comprised a gynaecological examination, urine culture, observation of residual urine and simultaneous urethro-cystometry including measurement of the urethral pressure profile.--The prolapse patients were operated upon by conventional Manchester technique. The patients suffering from both prolapse and stress incontinence were operated with a combined vaginal-abdominal repair using Lyodura slings.--It was found that the pre-operative urethral pressure at rest was lower in the inconinent-prolapse patients compared with that in patients suffering from prolapse only. After surgery the urethral pressure at rest was significantly decreased in the incontinent-prolapse patients whereas it did not change in patients operated because of prolaspe only.--Prior to the operation, all incontinent-prolapse women had a negative urethral closure pressure at stress. After surgery the closure pressure became positive in all patients and none complained about urinary incontinence. In all patients suffering from prolapse only the urethral closure pressure was positive at stress before as well as after surgery. The functional and the absolute urethral lengths increased in both categories of patients after the operation.