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Infrared spectroscopic ellipsometry is used to study the influence of strain and composition on the transverse-optical phonon mode of E[sub 1] symmetry in hexagonal Al[sub 1-x]In[sub x]N films for 0.12≤x≤0.21. The 0.1-0.2-μm thick films were grown on slightly compressively strained hexagonal GaN buffer layers, or directly on [0001] sapphire by metalorganic vapor phase epitaxy. The Al[sub 1-x]In[sub x]N E[sub 1](TO) phonon shows a one-mode behavior in contrast to recent theoretical predictions [H. Grille, C. Schnittler, and F. Bechstedt, Phys. Rev. B 61, 6091 (2000)]. Films grown on GaN reveal the influence of strain on the phonon mode frequencies due to pseudomorphic film growth. Al[sub 1-x]In[sub x]N deposited directly on sapphire possesses phonon modes which indicate fully relaxed film growth. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Wurtzite InGaN thin films grown by metalorganic chemical vapor deposition on sapphire substrates with and without GaN buffer layers are investigated by high-resolution x-ray diffraction measurements. The structural quality, lattice constants, strain, and indium composition of 100 nm thick films with In concentrations up to 33% are evaluated by measuring symmetric (00.2) and asymmetric (20.5) reflexes. The quality of the InGaN layers with widely different biaxial stress is measured and compared. An analytical solution for the determination of the In content of strained epitaxial layers is introduced. The results show that neglecting the strain can result in a severe miscalculation of the In concentration. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Mesenteric cysts are one of the most rare intra-abdominal tumours [1], classified as chylolymphatic, mesothelial (simple), enterogenous, urogenital remnant, dermoid cyst (teratomatous), gas, mycotic, parasitic, tubercular cysts and cysts following malignant degeneration [2]. Dermoid cysts are uncommon mesenteric cysts [3]. Cysts of the mesocolon are rare and usually differentiated from a mesenteric cyst only at the operation [4]. We here report a rare case of a dermoid cyst that was present in the mesentery of the transverse colon.

Congenital diaphragmatic hernia (CDH) which mainly occurs in the newborn or in childhood with severe respiratory distress and high mortality, is rarely found in adults (Yamaguchi et al. Ann Thorac Cardiovasc Surg 8:106-108, 2002; Dalencourt and Katlic Ann Thorac Surg 82:721-722, 2006; Fraser et al. Endosc Percutan Tech 19: e5-e7, 2009; Kanazawa et al. Surg Today 32:812-815, 2002). These patients are been accustomed to adjust their lifestyle to manage symptoms associated with frank herniation of the large bowel and liver inside the diaphragmatic hernial sac. Bowel above the liver surface especially the transverse colon is suggestive of a Chilaiditi's syndrome in these group of patients. Diagnostic laparoscopy plays an important role for diagnosis of diaphragmatic hernia in some cases over other investigations like CT scan and ultrasonography. Chilaiditi's syndrome has no surgical line of treatment but a symptomatic diaphragmatic hernia requires surgical correction. Liver as the main hernial content has been reported only in three cases throughout the world (Goh et al. Am J Surg 194: 390-391, 2007; Luo et al. Hepatobiliary Pancreat Dis Int 6: 219-221, 2007; Bosenberg and Brown RA Curr Opin Anaesthesiol 21: 323-331, 2008). A case of a 27 year old female patient presenting with a symptomatic congenital diaphragmatic hernia is reported.

Photoluminescence (PL) spectroscopy with subwavelength lateral resolution has been employed to probe individual localization centers in a thin InGaN/GaN quantum well. Spectrally narrow emission lines with a linewidth as small as 0.8 meV can be resolved, originating from the recombination of an electron-hole pair occupying a single localized state. Surprisingly, the individual emission lines show a pronounced blueshift when raising the temperature, while virtually no energy shift occurs for increasing excitation density. These findings are in remarkable contrast to the behavior usually found in macro-PL measurements and give a fundamental new insight into the recombination process in semiconductor nanostructures in the presence of localization and strong internal electric fields. We find clear indications for a biexciton state with a negative binding energy of about -5+/-0.7 meV.