Hydrogen storage performance of the multi-principal-component CoFeMnTiVZr alloy in electrochemical and gas–solid reactions

The single-phase multi-principal-component CoFeMnTiVZr alloy was obtained by rapid solidification and examined by a combination of electrochemical methods and gas–solid reactions. X-ray diffraction and high-resolution transmission electron microscopy analyses reveal a hexagonal Laves-phase structure (type C14). Cyclic voltammetry and electrochemical impedance spectroscopy investigations in the hydrogen absorption/desorption region give insight into the absorption/desorption kinetics and the change in the desorption charge in terms of the applied potential. The thickness of the hydrogen absorption layer obtained by the electrochemical reaction is estimated by high-resolution transmission electron microscopy. The electrochemical hydrogen storage capacity for a given applied voltage is calculated from a series of chronoamperometry and cyclic voltammetry measurements. The selected alloy exhibits good stability for reversible hydrogen absorption and demonstrates a maximum hydrogen capacity of ∼1.9 wt% at room temperature. The amount of hydrogen absorbed in the gas–solid reaction reaches 1.7 wt% at 298 K and 5 MPa, evidencing a good correlation with the electrochemical results.

The single-phase multi-principal-component CoFeMnTiVZr alloy was obtained by rapid solidification and examined by a combination of electrochemical methods and gas–solid reactions.     

Laparotomy prevents lethal endotoxemia in a murine sequential insult model by an IL-10-dependent mechanism

Multiple organ dysfunction and death are common sequelae after mesenteric ischemia-reperfusion injury as seen with mesenteric revascularization and thoracoabdominal aortic aneurysm repair. A second insult such as bacterial pneumonia occurring subsequent to the ischemia-reperfusion injury may contribute to these untoward effects. We hypothesized the sequential visceral/lower torso ischemia-reperfusion and endotoxemia in a murine model would increase the magnitude of the proinflammatory cytokine response and decrease survival. C57BL/6 mice underwent 20 min of supraceliac occlusion (IR), sham laparotomy (LAP), or no initial insult (CTRL) followed by intraperitoneal injection of a lethal dose of endotoxin (LPS [lipopolysaccharide 50 mg/kg] or saline vehicle at 24 h. Serum cytokine levels were measured by enzyme-linked immunosorbent assay (IL-10, IL-6) or WEHI bioassay [tumor necrosis factor (TNF)], and survival was determined at 5 days. The role of IL-10 on the TNF response and survival was examined in a subset of mice given mouse anti IL-10 IgM (25 mg/kg intraperitoneally) 2 h prior to the initial insult. Survival after LPS was significantly different (P < 0.05) among the treatment groups (IR, 64%; LAP, 55%; CTRL, 11%) and appeared to trend directly with the magnitude of the initial operation. The serum IL-10 levels in the IR and LAP groups were significantly increased 4 h after the initial insult and remained elevated at 24 h. Peak serum TNF levels after LPS were significantly lower in the IR and LAP groups. Administration of anti IL-10 IgM resulted in uniform mortality and a significant increase in the peak TNF levels after LPS administration for all initial treatment groups. Endogenous production of IL-10 following laparotomy down-regulates the TNF response and improves survival after endotoxemia.     

The influence of duration of breastfeeding on bone mass in postmenopausal women of different age groups

This study examines the influence of duration of breastfeeding on bone mineral density (BMD) and investigates the relationship between duration of breastfeeding and bone mass at four sites in postmenopausal women of different ages. A total of 509 postmenopausal women aged 45-86 years were included in the study. Patients were divided into three groups: never breastfed (n=67), < 96 months (n=157) and > or = 96 months (n=285); they were further classified into two age groups, 40-59 years (n=233) and 60-80 years (n=276). In all patients and in the 40-59 year age group, BMD of the spine was found to be significantly lower in the never-breastfed group, while BMD of the trochanter was significantly lower in the > or = 96 month breastfeeding group. BMD of the spine and femur tended to decrease with longer breastfeeding in all groups, while BMD of the spine and trochanter tended to decrease with longer breastfeeding in the 40-59 year group. Of patients in the 60-80 year group who had never breastfed, spinal BMD was significantly higher than that of the > or = 96 month group, while in the > or = 96 month group trochanter BMD was significantly lower than in other groups. In the never-breastfed group, ward's triangle BMD was significantly higher than that of other groups. There was a significant correlation between duration of breastfeeding and BMD of the spine, neck, trochanter and ward's triangle. The study suggests that duration of breastfeeding has an effect on BMD, and extended breastfeeding leads to lower BMD.     

Endovascular management of juxtarenal aneurysms with fenestrated endovascular grafting

PURPOSE: To evaluate the technical feasibility and short-term results of juxtarenal aneurysm repair with an endovascular graft that incorporated the visceral aortic segment with graft material. METHODS: Patients were studied prospectively after the implantation of an endovascular device with graft material extending proximal to the renal arteries, variably incorporating the superior mesenteric and celiac arteries. All patients were deemed to be high risk with respect to open surgical repair and had compromised proximal neck anatomy. Proximal neck lengths were 相似文献   

Nasality evaluation of Turkish phonemes in vowel-consonant combinations

Objectives

The purpose of this study is to find average nasalance values of Turkish syllables with the nasometer.

Methods

This study is done at Hacettepe University Department of Otolaryngology Audiology and Speech Pathology Unit with 50 participating children.

Results

The normative nasalance values of Turkish phonemes are determined. It is found that nasalance scores of syllables that is combined with/i/phoneme is statistically have higher nasalance scores than/a/and/e/phonemes (p < 0.05). There is no difference find statistically between age and nasalance value (p > 0.05). Statistical difference between age and nasalance score is found in “iki, ?e, e?e, i?i, aç, eç, çi, içi, iç, al, yi, iy, iyi, yiy, ana, ne” syllables (p < 0.05). These phonemes have positive relation with the age. There is no statistical difference between sex and nasalance scores (p < 0.05). Statistical difference is only found in “tat- te- li- lil- aya” syllables (p < 0.05). On these phonemes it is found that girls have higher nasalance score than boys.

Conclusion

As a result, it is thought that gathered nasalance values of Turkish phonemes will be useful for resonance disorder diagnosis and follow ups on treatment.     

Twenty years of experience with perineal injury in children

Purpose

The aim of this study was to review our 20 years of experience determining the common mechanisms of perineal trauma and initial management to evaluate the effects of classification for treatment.

Methods

A total of 75 children with perineal injuries were reviewed retrospectively, including patient demographics, mechanism of injury, associated injuries, injury severity score, presenting symptoms and methods of diagnosis and treatment.

Results

Amongst the 75 children (55 females and 20 males; mean age, 8 years), fall from height, followed by motor vehicle crash and sexual abuse were the most common reasons for injury. The most common symptom on presentation was bleeding, followed by abdominopelvic pain and tenderness. Eleven patients were allowed to heal secondarily, and 64 were examined under general anaesthesia. The affected area was repaired in 48, further diagnostic tools were needed in 20 and 11 cystoscopic, 10 rectoscopic, and 5 vaginoscopic evaluations were performed. Six patients with full-thickness injuries that extended to the peritoneum were treated with colostomy, and all were victims of motor vehicle crashes.

Conclusion

The genital injury score is a useful genital trauma scale for predicting anogenital injury severity. Identifying the mechanism and severity of perineal and associated injuries under general anaesthesia may facilitate appropriate classification and management.

     

Short and long-term results of the Karydakis flap versus the Limberg flap for treating pilonidal sinus disease: a prospective randomized study

Background

Pilonidal sinus is a common disease that mostly affects young people. Although various surgical techniques have been described for treating sacrococcygeal pilonidal disease (SPD), controversy still exists as to the best surgical technique. The purpose of this study was to compare the efficiency and short-term and long-term results of the Karydakis flap with that of the Limberg flap for treating SPD.

Methods

In this prospective randomized study, 269 patients with SPD were recruited to undergo either the Karydakis flap (n = 135) or the Limberg flap (n = 134) procedure between September 2004 and September 2008.

Results

The mean operative time for the Karydakis group (42.32 ± 8.64 minutes) was shorter than that for the Limberg group (50.14 ± 6.96 minutes) (P = .01). The complication rate for the Karydakis group (n = 15 [11.1%]) was lower than that for the Limberg group (n = 28 [20.8%]) (P = .029). The visual analogue scale score for postoperative pain at the operation site on the 30th day was lower in the Karydakis group than in the Limberg group (2.22 ± 1.01 vs 3.23 ± 1.14, P = .01). The visual analogue scale score for satisfaction with the cosmetic appearance of the scars in the Karydakis group was 7.08 ± 1.75, whereas it was 3.16 ± 1.40 in the Limberg group at the 3rd month (P = .01). Length of hospital stay was significantly shorter in the Karydakis group than in the Limberg group (3.40 ± .94 vs 3.8 ± 1.19 days, P = .03). Only 4 patients in the Karydakis group developed recurrence (3%), whereas 9 patients (6.9%) did so in the Limberg group (P = .151).

Conclusions

The Karydakis flap procedure should be chosen instead of the Limberg flap for treating uncomplicated SPD because of its lower postoperative complication rate, lower pain scores, shorter operation time and length of hospital stay, and good cosmetic satisfaction. However, no differences existed between the 2 surgical procedures in terms of recurrence prevention.