Transmission of a Symmetric Light Pulse through a Wide QW

The reflection, transmission and absorption of a symmetric electromagnetic pulse, which carrying frequency is close to the frequency of an interband transition in a QW (QW), are obtained. The energy levels of a QW are assumed discrete, one exited level is taken into account. The case of a wide QW is considered when a length of the pulse wave, appropriate to the carrying frequency, is comparable to the QW's width. In figures the time dependencies of the dimensionless reflection, absorption are transmission are represented. It is shown, that the spatial dispersion and a distinction in refraction indexes influence stronger reflection.Comment: 8 pages,8 figures with caption

Associated Complication of Gastrointestinal Stromal Tumours of the Small Intestine

Aim. To consider the possibility of the diagnosis of a rare small bowel tumour complicated by small bowel obstruction and small bowel bleeding, as well as the surgical treatment of this pathology using a minimally invasive surgical approach.Results and discussion. The authors present a clinical case of associated complication of a gastrointestinal stromal tumour (GIST) of the small intestine in a 48-year-old patient. The patient was admitted to a surgical clinic with small bowel obstruction, episodes of intestinal bleeding and anaemia. The diagnosis was determined using CT enterography. In line with the current trends for minimally invasive surgery, minimally invasive laparotomy was performed drawing on the CT mapping of the anterior abdominal wall. The last stage involved in the morphological verification of GIST, which employs a standard procedure of IHC testing, revealed a malignant GIST, spindle cell variant. The verified histotype of a small intestinal tumour provides the opportunity to choose the necessary variant of adjuvant chemotherapy, as well as to improve general and relapse-free survival.Conclusion. Minimally invasive operations can be performed in the complicated course of GIST due to the biological properties of this pathology (absence of lymphogenic metastasis and infiltrative growth) without decreasing five-year survival rate. The use of CT helps make a topical diagnosis and plan minimally invasive surgical treatment

Characteristic features of the nanocrystalline structure formation in Ln2Hf2O7Ln_{2}Hf_{2}O_{7} (Ln = Gd, Dy) compounds

A combination of modern locally sensitive methods of structure analysis based on the interaction of synchrotron radiation with condensed matter was used to study the formation and evolution of crystal structures, change in the size of crystallites, the type and degree of cationic ordering, and features of the local atomic structures of compounds Ln2Hf2O7 (Ln = Gd, Dy) prepared by heat treatment of X-ray amorphous precursors