Dielectric, magnetic and structural properties of novel multiferroic Eu(0.5)Ba(0.5)TiO(3) ceramics.

Dielectric properties of Eu(0.5)Ba(0.5)TiO(3) ceramics were investigated between 10 and 300 K in the frequency range of 1 MHz-100 THz. Permittivity exhibits a strong peak near the ferroelectric phase transition at 215 K. This is mainly due to softening of the lowest frequency polar phonon revealed in THz and infrared spectra. Dielectric relaxation was observed also below the ferroelectric soft mode frequency in the whole investigated temperature region, but it is probably caused by some defects such as Eu(3 + ) cations or oxygen vacancies. This implies that the ferroelectric phase transition has predominantly a displacive character. Raman scattering spectra revealed a lowering of crystal symmetry in the ferroelectric phase and XRD analysis indicated orthorhombic A2mm symmetry below 215 K. The magnetic measurements performed at various frequencies in the field cooled and field heating regime after cooling in zero magnetic fields excluded spin glass behavior and proved an antiferromagnetic order below 1.9 K in Eu(0.5)Ba(0.5)TiO(3).

The structure and growth mechanism of Si nanoneedles prepared by plasma-enhanced chemical vapor deposition.

Silicon nanowires and nanoneedles show promise for many device applications in nanoelectronics and nanophotonics, but the remaining challenge is to grow them at low temperatures on low-cost materials. Here we present plasma-enhanced chemical vapor deposition of crystalline/amorphous Si nanoneedles on glass at temperatures as low as 250 °C. High resolution electron microscopy and micro-Raman spectroscopy have been used to study the crystal structure and the growth mechanism of individual Si nanoneedles. The H(2) dilution of the SiH(4) plasma working gas has caused the formation of extremely sharp nanoneedle tips that in some cases do not contain a catalytic particle at the end.

Creating nanocrystals in amorphous silicon using a conductive tip.

Field-enhanced metal-induced solid phase crystallization (FE-MISPC) of amorphous silicon is scaled down to nanoscale dimensions by using a sharp conductive tip in atomic force microscopy (AFM) as one of the electrodes. The room temperature process is driven by the electrical current of the order of 100 pA between the tip and the bottom nickel electrode. This results in energy transfer rates of 30-50 nJ s(-1). Amplitude of the current is limited by a MOSFET transistor to avoid electrical discharge from parasitic parallel capacitance. Limiting the current amplitude and control of the transferred energy (approximately 100 nJ) enables formation of silicon crystals with dimensions smaller than 100 nm in the amorphous film. Formation of the nanocrystals is localized by the AFM tip position. The presence of nanocrystals is detected by current-sensing AFM and independently corroborated by micro-Raman spectroscopy. The nanocrystal formation is discussed based on a model considering microscopic electrical contact, thermodynamics of crystallization and silicide formation.

Factors affecting recurrence after incisional hernia repair.

Incisional hernias occur primarily as a result of high tension and inadequate healing of a previous incision, the latter of which is frequently related to infection at the surgical site. Despite recent advances in operative techniques, the recurrence rate remains unacceptably high. To evaluate the impact of different predisposing factors for the recurrence of incisional hernia, we reviewed retrospectively the medical records of 297 patients who had undergone incisional herniorrhaphy (188 tissue repairs, 109 mesh repairs) in our hospital. Demographic data (age and gender), type of repair, body mass index, hernia size, presence of chronic illnesses and wound complications were evaluated in a univariate and multivariate manner analysis. The overall recurrence rate was 30.3%, with the recurrence rate in patients who underwent tissue repair being 39.4% and that in patients following prosthetic repair 14.6%. The recurrence rate was significantly influenced by type of repair, obesity, hernia size, wound healing disorders and some chronic comorbidities. We conclude that it is necessary to become familiar with the risk factors for recurrence of incisional hernia in order to eliminate or decrease their effect on the positive outcome of incisional herniorrhaphy.

The basket plate in the osteosynthesis of comminuted fractures of distal pole of the patella.

The purpose of this study was to evaluate the basket plate in the treatment of comminuted fractures of the distal pole of the patella (patellar apex fracture). The basket plate was designed by Smiljanic Branimir M.D., Clinical Professor of Surgery, at the Department of Surgery, The University Hospital Sestre milosrdnice, Zagreb, Croatia. In the period from 1988 to 2003, more than 100 patients with comminuted patellar apex fractures had been treated with basket plate osteosynthesis in the Department of Surgery. Only 51 patients were subsequently available for knee examination. For evaluation of the knee, we used a modified Cincinnati knee rating system, using a manual dynamometer in the evaluation of the knee extension. The results were excellent in 30 patients, good in 16 and satisfactory in 5 patients; no poor results were observed. The stability of the osteosynthesis by basket plate allows osseous consolidation if the fracture and permits loading the leg with full body weight early in the postoperative period.

Phagocytic functions of salivary neutrophils in oral mucous membrane diseases.

BACKGROUND AND PURPOSE: Phagocytic functions of salivary polymorphonuclear neutrophils (sPMNs) have not been comprehensively studied in patients with oral mucous membrane diseases, although available data suggest the role of immunity in their pathogenesis. SUBJECTS AND METHODS: Phagocytic functions of sPMN were determined in 15 patients with acute recurrent aphthous ulceration (RAU), 11 patients with oral lichen planus (OLP) and 20 healthy volunteers. In healthy subjects, the same parameters were also determined in peripheral blood polymorphonuclear neutrophils (bPMNs). Phagocytic activity (proportion of ingesting cells, PA), ingestion ability (number of ingested targets per 100 phagocytes, IA) and intracellular microbicidity (proportion of killed targets, IM) of PMNs separated from peripheral blood and the whole unstimulated saliva were determined by acridine orange method with living yeast cells as targets. RESULTS: Salivary PMNs in healthy individuals showed significant reduction in PA (33% vs. 76%; P < 0.009) and IA (0.47% vs. 2.93%; P < 0.009) and significant increase in IM (12.0% vs. 5.5%; P = 0.011) in comparison with bPMNs. In RAU patients, reduced PA (27% vs. 37%; P = 0.035) and IA (0.25% vs. 0.47%; P = 0.05) were detected, while in OLP patients enhanced IM was detected (12% vs. 19%; P = 0.033) in comparison with healthy controls. CONCLUSION: Salivary PMNs present functional features distinct from those in peripheral blood. Some phagocytic functions of sPMNs are reduced in RAU and enhanced in OLP, indicating their role in pathogenesis or reflecting clinical changes in these conditions.

Safety of simultaneous resections of colorectal cancer and liver metastases.

Liver resection is the only potentially curative method for patients with colorectal cancer metastases and 5-year survival rates are 20%-40%. Simultaneous resection of colorectal cancer and synchronous liver metastases has been recommended if minor hepatectomy is indicated. The purpose of this paper is to analyze the treatment of hepatic colorectal secondaries and to assess the safety of simultaneous and delayed liver resections and relations of morbidity to the extensiveness of hepatectomy and perioperative factors. Analyzed were 21 patients with liver metastases from colorectal cancer operated between 1997 and 1999 in the Clinical Hospital "Sestre milosrdnice". Operating time for simultaneous colorectal and liver resections was not significantly longer compared to liver resections alone. No significant difference in complication rate was found after simultaneous procedures and liver resection alone (38% vs. 31%). Complication rate after major liver resections was not significantly greater than after minor resections (38% vs. 31%). No statistically significant differences were found in operation time and blood replacement between patients who developed postoperative complications and those who did not. In conclusion, simultaneous resections of primary colorectal cancer and liver metastases may be considered safe. Morbidity rates are not significantly different from those after liver resections alone, nor depend significantly upon the extensiveness of liver resection, providing that the operation time and blood loss are within the range observed in this study.

Some structural characteristics of the inguinal region in the northern Croatia.

In studying anatomical samples of both inguinal hernia patients and healthy controls with no changes observable in the inguinal region, the authors aimed at investigating the constitution of the inguinal region in relation to the formation of inguinal hernia. The morphological investigation of 68 anatomical samples and 44 inguinal regions at autopsy, revealed that the length of the interspinal line, independent of sex, varies from 180 to 310 mm and is 63 to 132 mm removed from the pubic tubercle (the height of the anterior pelvic arch). Thus, in 35% of male and 22% of female subjects the height of the anterior pelvic arch exceeded 75 mm indicating a low position of the groin. The research carried out in 640 inguinal hernia patients and 186 controls indicated a shift towards higher values in the interspinal line in inguinal hernia patients as compared with the controls. In addition, the height of the anterior pelvic arch in patients with inguinal hernia conspicuously exceeded that observed in the controls. The present study undoubtedly shows that the number of muscle and connective structure variations of the inguinal region depends upon the position of the groin in relation to the interspinal plane. The authors therefore agree with the classification of these relationships to high, medial and low groin position. The high position of the pubic tubercles up to 75 mm removed from the interspinal spine is accompanied with the firm constitution of the entire inguinal region. Moreover, the medical position of pubic tubercles 75 to 90 mm removed from the interspinal line does not indicate the risk of developing inguinal hernia. On the other hand, the low position of the pubic tubercles more than 90 mm removed from the interspinal line is often due to the inferior constitution of the inguinal region. This group is regularly at higher risk of developing inguinal hernia, particularly with other risk factors being added as well. The identification of structural characteristics of the inguinal region therefore enables the selection of the most appropriate operation procedure, i.e. between the classic hernia repair and endoscopic approach for prosthetic mesh implantation.