SiGe quantum dot crystals with periods down to 35 nm.

By combining extreme ultraviolet interference lithography with Si/Ge molecular beam epitaxy, densely packed quantum dot (QD) arrays with lateral periodicities down to 35 nm are realized. The QD arrays are featured by perfect alignment and remarkably narrow size distribution. Also, such small periodicities allow the creation of three-dimensional QD crystals by vertical stacking of Si/Ge layers using very thin Si spacer layers. Simulations show that the distances between adjacent QDs are small enough for coupling of the electron states in lateral as well as vertical directions.

Fabrication of high-resolution large-area patterns using EUV interference lithography in a scan-exposure mode.

Limited beam spot size is a major limitation of interference lithography. This limits the area of patterning and reduces the pattern homogeneity. We describe a scanning exposure technique to circumvent this problem. We show the generation of uniform and seamless gratings with half-pitches down to 35 nm over an area of several mm(2) using EUV interference lithography. The presented technique offers a fast and cost-effective method of fabricating one- and two-dimensional periodic nanostructures with improved uniformity and increased patterning area.

Investigation of Effects of Two Chronic Stress Protocols on Depression-Like Behaviors and Brain Mineral Levels in Female Rats: an Evaluation of 7-Day Immobilization Stress.

We aimed to investigate the effects of two different chronic immobilization stress protocols on depression-related behaviors and brain mineral levels. Adult female Wistar albino rats were divided into 3 groups as follows (n = 10/group): control, immobilization stress-1 (45 min daily for 7 days), and immobilization stress-2 (45 min twice a day for 7 day). Stress-related behavior was evaluated by means of the forced swimming test (FST) and open field test (OFT). Minerals were analyzed using an inductively coupled plasma mass spectrometer. In the FST, swimming and immobility were significantly lower in the immobilization stress-1 and immobilization stress-2 groups. The climbing duration of the immobilization stress-2 group was higher than the control group. In the OFT, percentage of time spent in the central area was significantly lower in the immobilization stress-1 and immobilization stress-2 groups. Values of latency to center area, rearing, and grooming did not significantly differ between groups. In the immobilization stress-1 group, zinc was lower, and iron, copper, and manganese were higher than the control group. In the immobilization stress-2 group, copper and manganese were higher, and phosphate was lower than the control group. Our results showed that depression-related behaviors were more dominant in the immobilization stress-1 group. A decrease in the brain zinc level was valid only for the immobilization stress-1 group. These results point to the role of low brain zinc levels in the pathophysiology of depression.

Direct formation of ZnO nanostructures by chemical solution deposition and EUV exposure.

The development of effective methods for the fabrication of ZnO nanostructures is important for the use of this semiconductor material with interesting optical and electronic properties. Chemical solution deposition methods have been demonstrated for creating ZnO films and electron beam exposure of a precursor film, zinc naphthenate, has been shown to yield ZnO nanostructures. Here, we report on the fabrication of ZnO nanostructures with photon beam exposure of a precursor film in the extreme ultraviolet range followed by a high temperature anneal in air. Interference lithography at this wavelength (13.5 nm) led to the production of extremely smooth line/space and dot array type periodic nanostructures with sizes as small as 10 nm. ZnO films obtained through EUV exposure exhibit markedly improved PL spectra with a sharp emission line in the UV range and much suppressed green emission. Electron microscopy and x-ray diffraction measurements also show strong effects of the EUV exposure step in ZnO formation as a function of precursor film thickness, EUV exposure dose and anneal temperature. The use of energetic photons for direct formation of ZnO nanostructures is found to be a method that warrants more investigation for the fabrication of patterned ZnO films with controlled properties.

Electric and magnetic resonances in arrays of coupled gold nanoparticle in-tandem pairs.

We present an experimental and theoretical study on the optical properties of arrays of gold nanoparticle in-tandem pairs (nanosandwiches). The well-ordered Au pairs with diameters down to 35 nm and separation distances down to 10 nm were fabricated using extreme ultraviolet (EUV) interference lithography. The strong near-field coupling of the nanoparticles leads to electric and magnetic resonances, which can be well reproduced by Finite-Difference Time-Domain (FDTD) calculations. The influence of the structural parameters, such as nanoparticle diameter and separation distance, on the hybridized modes is investigated. The energy and lifetimes of these modes are studied, providing valuable physical insight for the design of novel plasmonic structures and metamaterials.

Cilostazol enhances atorvastatin-induced vasodilation of female rat aorta during aging.

Statins have cholesterol-independent effects including an increased vascular nitric oxide activity and are commonly used by patients with cardiovascular disease. Such patients frequently have cardiovascular diseases, which may be treated with cilostazol, a platelet aggregation inhibitor. This study was designed to investigate whether combined use of cilostazol would increase the inhibitory effect of statin on vascular smooth muscle and how maturation would affect these responses. Female Wistar rats, aged 3-4 months (young) and 14-15 months (adult), were sacrificed by cervical dislocation and the thoracic aorta was dissected and cut into 3- to 4-mm-long rings. The rings were mounted under a resting tension of 1 g in a 20-ml organ bath filled with Krebs-Henseleit solution. Rings were precontracted with phenylephrine (10-6 M), and the presence of endothelium was confirmed with acetylcholine (10-6 M). Then, the concentration-response curves were obtained for atorvastatin alone (10-10 to 3 × 10-4 M; control) and in the presence of cilostazol (10-6 M) in young and adult rat aortas. This experimental protocol was also carried out in aorta rings, which had been pretreated with NG-nitro-l-arginine methyl ester (l-NAME, 10-4 M). Atorvastatin induced concentration-dependent relaxations in young and adult rat thoracic aorta rings precontracted with phenylephrine. The pIC50 value of atorvastatin was significantly decreased in adult rat aortas. In addition, pretreatment of aortas with cilostazol enhanced the potency of atorvastatin in both young and adult aortas. Incubation with l-NAME did not completely eliminate the relaxations to atorvastatin in the presence of cilostazol. These results suggest that combined application of cilostazol with atorvastatin was significantly more potent than atorvastatin alone. Combined drug therapy may be efficacious in delaying the occurrence of cardiovascular events.

Methods of treatment of childhood empyema in a Turkish university hospital.

In the last ten years, 120 patients were admitted to our clinic with empyema. Empyema and effusion have been investigated for pathogenesis. Microbiologic studies of pleural aspiration fluid showed that Staphylococcus aureus was the most common pathogen, found in 44 patients (36.7 percent). Other pathogens found were streptococci in 23 (19.2 percent) and Pneumococcus in 18 (15 percent) in sequence. No production occurred in cultures of 19 (15.8 percent) patients. In 16 (13.3 percent), Pseudomonas and Enterobacteria such as E coli, Klebsiella and Proteus occurred. Surgical intervention has been carried out depending on clinical conditions. In the 24 (20 percent) patients, pleural aspiration and lavage, decortication in 23 (19.2 percent), pulmonary resection (segmentectomy, lobectomy) in seven (5.8 percent), and only drainage and thoracic lavage in 66 (52.5 percent) have been carried out. Three patients (2.5 percent) died due to respiratory failure and septic shock, and the others have been discharged with healing.

Chest injuries in civilian life and their treatment.

Between 1971 and 1980, some 1,452 patients who had injuries to their chest were hospitalized and treated in our clinic; 949 (65.4 percent) of them had blunt chest injury, and 504 (34.7 percent) had open chest injury. Conservative treatment was given in 1,327 cases. Surgical exploration was carried out in the remaining 125 patients. Twenty-nine of these patients (2 percent) were operated on immediately, and late thoracotomy was carried out in 96 (8 percent). A total of 1,272 of the patients who had conservative treatment (95.9 percent) and 118 who had surgery (94 percent) recovered. The overall mortality in patients who had conservative treatment was 4.1 percent (55 cases) and in those who had surgery was 6 percent (seven cases).

Dangerous pencils and a new technique for removal of foreign bodies.

Aspirated foreign bodies are important problems during childhood. Some instances may be fatal. Most of the foreign bodies are removed with use of classic instruments like rigid bronchoscopes and foreign body forceps. But sometimes we fail to remove them, particularly aspirated beads and spherical objects. In this case, a Fogarty catheter is helpful. Although we have had many experiences recently we failed to remove one aspirated foreign body which was a pencil cap. We succeeded in removing this pencil cap with a new technique that is explained in this article. We used a Storz transbronchial aspiration biopsy needle and a cotton-carrier stylet to remove the pencil cap.

Peripheral vascular injuries in children.

We report 94 arterial injuries in 91 children treated at the Department of Thoracic and Cardiovascular Surgery, Medical School of Dicle University, between 1978 and 1988. The average age was 10.3 (range, 3 to 14) years. Stab wounds were seen in 37 patients (40%). Gunshot wounds were seen in 21 patients (23%), and two cases were caused by iatrogenesis. Vein damage was present in 39 patients (44.4%), and nerve loss was observed in 20 patients (21.2%). Twenty-one cases (23.3%) were associated with fractures. Diagnosis of arterial injury was made by clinical findings. Arteriography was used in 15 patients (16.5%) as the diagnostic method. The surgical interventions performed for arterial repair in our series were end-to-end anastomosis in 61 (64.5%), interposition of autogenous reversed saphenous vein grafts in 22 (23.4%), lateral suture in 8 (8.3%), and ligation in 3 (3.9%) patients. Four patients (5.3%) underwent limb amputation.

Empyema thoracis--a series of 230 cases.

A retrospective analysis of 230 cases of empyema thoracis which occurred in our clinic during the last 14 years have been presented. The causes, the pathogen organism, treatment with antibiotic are enumerated. The surgical treatment carried in resistant cases have been described Ten patients (4.34 percent) died due to respiratory failure and septic shock. Importance of early and appropriate treatment has been stressed.

Lung hydatid cyst rupture and its surgery.

Hydatid cysts are common in Turkey. Authors have seen 248 cases of lung hydatid cysts; Fifty hydatid cyst of lung had ruptured. Their symptoms and detailed findings are reported. Rupture caused asphyxia in 3, haemoptysis in 20, lung abcess in 16, rupture in pleural cavity in 4 and anaphylactic reaction in one case.

The pH changes of four different calcium hydroxide mixtures used for intracanal medication.

The purpose of this study was to determine the pH values of calcium hydroxide mixtures in combination with either distilled water, two different local anaesthetic solutions or physiological saline solution, which are commonly used as a dressing materials during endodontic treatment. The pH of each vehicle prior to mix with calcium hydroxide and subsequently each prepared combination was determined using a digital pH meter. The pH measurements were determined at 3 min, 10 min, 1 h, 24 h, 48 h and 7 days. The results of this study indicated that four different water-based vehicles demonstrated similar pH changes range within pH 11-12 when mixed with calcium hydroxide.

[In vitro investigation of Gutta-percha amounts in different root obturation techniques]. / Farkli kanal dolgu tekniklerinde kök kanallarinin içerdigi Güta-perka miktarlarinin in vitro olarak incelenmesi.

Several obturation techniques and obturation materials are developed in order to fill the root canals completely. It was necessary to fill the root canals with solid and semisolid materials due to the unproduction of an ideal root canal sealer. The well known material that is being used, for this purpose today is gutta-percha. Single cone techniques, lateral condensation techniques and thermoplastic gutta-percha enjection techniques are used with sealers and without sealers in single rooted 30 teeth. And than, the amount of gutta-percha were evaluated by mean of herizontally taken section from 3 different levels of root canals. Finally the gutta-percha enjection techniques found to contein more gutta-percha amount in all three section levels than the single cone techniques and laterally condancation technique.

[A case of bronchial leiomyoma]. / Ein Fall von bronchialem Leiomyom.

Pulmonary leiomyomas are the least common benign tumors of the lung. These tumors originate from smooth muscles of the bronchial walls, peripheral small airways, or from perivascular smooth muscles. It is reported that the diagnosis of the tumor has been established bronchoscopically and proved with thoracotomy. The characteristics of the tumor and treatment modalities are discussed.

Supravalvular aortic stenosis without Williams syndrome.

In this article, the case of a 30-years-old female patient with supravalvular aortic stenosis is reported. Her clinical picture was otherwise completely different from Williams syndrome. Since supravalvular aortic stenosis is rarely seen, its forms are discussed and it is concluded that supravalvular aortic stenosis can be present without Williams syndrome.

The hydatid cyst of the lung in children and results of surgical treatment.

Between 1976 and 1986 one hundred and ten children with pulmonary hydatid disease were treated surgically. Sixty five of the patients were males and 45 were females. We diagnosed hydatid cyst in 36 cases submitted in our clinic with hemoptysis. Thirty of the patients had cough, 16 had chest pain and dyspnea, 12 had purulent sputum and 8 cases had fever and anaphylactic phenomena. In most of the patients hydatid cysts were localised in the right lung. However, they had affinity for the lower lobes of both lungs, rather than the upper lobes. The radiological examination was found to be the most reliable diagnostic method. In the majority of our cases we performed thoracotomy + cystotomy + capitonnage, while in some cases we performed resection, like cystectomy, wedge resection and lobectomy. We did not encounter any serious operative and postoperative complications, except for one pleural empyema and a single case of mortality.

Injuries of the peripheral arteries and their surgical treatment.

196 cases of peripheral arterial injury presented to our clinic between 1976 and 1986 are summarised. Most of the cases were between 11 and 30 years of age and most of the injuries were by fire-arms and sharp weapons. The most common localisations were a. femoralis (29% cases), a. poplitea and branches (28%), a. brachialis injury (20%). The most common surgical measures were end-to-end anastomosis (43% cases) and venous orthograft replacement (17%). There were 5 mortalities. Factors affecting treatment success are discussed.