Exciton energy transfer in nanotube bundles

Photoluminescence is commonly used to identify the electronic structure of individual nanotubes. But, nanotubes naturally occur in bundles. Thus, we investigate photoluminescence of nanotube bundles. We show that their complex spectra are simply explained by exciton energy transfer between adjacent tubes, whereby excitation of large gap tubes induces emission from smaller gap ones via Forster interaction between excitons. The consequent relaxation rate is faster than non-radiative recombination, leading to enhanced photoluminescence of acceptor tubes. This fingerprints bundles with different compositions and opens opportunities to optimize them for opto-electronics.Comment: 5 pages, 5 figure

MOISTURE CONTENT OF NATURAL GAS IN BOTTOM HOLE ZONE

For the traditional problem of gas flow to a well in the center of circular reservoir, the influence of initial reservoir conditions on dynamics of gas moisture content distribution has been determined. Investigations have been performed in the framework of mathematical model of non-isothermal real gas flow through porous media where heat conductivity was considered to be negligible in comparison with convective heat transfer. It is closed by empirical correlation of compressibility coefficient with pressure and temperature, checked in previous publications. Functional dependence of moisture content in gas on pressure and temperature is based on empirical modification of Bukacek relation. Numerical experiment was performed in the following way. At first step, axisymmetric problem of non-isothermal flow of real gas in porous media was solved for a given value of pressure at the borehole bottom, which gives the values of pressure and temperature as functions of time and radial coordinate. Conditions at the outer boundary of the reservoir correspond to water drive regime of gas production. At the second step, the calculated functions of time and coordinate were used to find the analogous function for moisture content. The results of experiment show that if reservoir temperature essentially exceeds gas – hydrate equilibrium temperature than moisture content in gas distribution is practically reflects the one of gas temperature. In the opposite case, gas will contain water vapor only near  bottom hole and at the rest of reservoir it will be almost zero. In both cases, pressure manifests its role through the rate of gas production, which in turn influences convective heat transfer and gas cooling due to throttle effect

Emergence of additional visible range photoluminescence due to aggregation of cyanine dye:astraphloxin on carbon nanotubes dispersed with anionic surfactant

Self-organization of organic molecules with carbon nanomaterials leads to formation of functionalized molecular nano-complexes with advanced features. We present a study of physical and chemical properties of carbon nanotube-surfactant-indocarbocyanine dye (astraphloxin) in water focusing on aggregation of the dye and resonant energy transfer from the dye to the nanotubes. Self-assembly of astraphloxin is evidenced in absorbance and photoluminescence depending dramatically on the concentrations of both the dye and surfactant in the mixtures. We observed an appearance of new photoluminescence peaks in visible range from the dye aggregates. The aggregates characterized with red shifted photoluminescence peaks at 595, 635 and 675 nm are formed mainly due to the presence of surfactant at the premicellar concentration. The energy transfer from the dye to the nanotubes amplifying near-infrared photoluminescence from the nanotubes is not affected by the aggregation of astraphloxin molecules providing important knowledge for further development of advanced molecular nano-complexes. The aggregation with the turned-on peaks and the energy transfer with amplified photoluminescence create powerful tools of visualization and/or detection of the nanotubes in visible and near-infrared spectral range, respectively, boosting its possible applications in sensors, energy generation/storage, and healthcare

Wideband-tuneable, nanotube mode-locked, fibre laser

Ultrashort-pulse lasers with spectral tuning capability have widespread applications in fields such as spectroscopy, biomedical research and telecommunications1–3. Mode-locked fibre lasers are convenient and powerful sources of ultrashort pulses4, and the inclusion of a broadband saturable absorber as a passive optical switch inside the laser cavity may offer tuneability over a range of wavelengths5. Semiconductor saturable absorber mirrors are widely used in fibre lasers4–6, but their operating range is typically limited to a few tens of nanometres7,8, and their fabrication can be challenging in the 1.3–1.5 mm wavelength region used for optical communications9,10. Single-walled carbon nanotubes are excellent saturable absorbers because of their subpicosecond recovery time, low saturation intensity, polarization insensitivity, and mechanical and environmental robustness11–16. Here, we engineer a nanotube–polycarbonate film with a wide bandwidth (>300 nm) around 1.55 mm, and then use it to demonstrate a 2.4 ps Er31-doped fibre laser that is tuneable from 1,518 to 1,558 nm. In principle, different diameters and chiralities of nanotubes could be combined to enable compact, mode-locked fibre lasers that are tuneable over a much broader range of wavelengths than other systems

Non-muscle invasive Bladder Cancer. Intravesical chemotherapy and BCG

Treatment of bladder cancer remains a challenge which should take a comprehensive approach that includes removal of the tumor, preventing recurrence of tumor, dispensary observation. Intravesical therapy is used in the treatment of superficial transitional cell bladder cancer (Та, T1 and carcinoma in situ) in order to treat existing or residual tumor, relapse prevention, prevention of disease progression and prolongation of life for patients. The primary stage of the disease and the degree of differentiation of the tumor were important determinants of prognosis, regardless of treatment. Intravesical chemotherapy reduces the recurrence of tumors by 22% of. At present, BCG immunotherapy remains the most effective treatment and prevention of transitional cell bladder cancer (Та, T1, carcinoma in situ): reduces the recurrence of the tumor, disease progression by 34%.Лечение рака мочевого пузыря остается сложной задачей при которой должен использоваться комплексный подход, включающий удаление опухоли, профилактику рецидивов новообразования, диспансерное наблюдение. Внутрипузырная терапия используется в лечении поверхностного переходно-клеточного рака мочевого пузыря (Та, Т1 и карциномы in situ) с целью лечения существующей или остаточной опухоли, профилактики рецидивов, предотвращения прогрессии заболевания и продления жизни пациентов. Первичная стадия заболевания и степень дифференцированности опухоли остаются важными факторами, определяющими прогноз заболевания, независимо от лечения. По данным клиники урологии УГМА, внутрипузырная химиотерапия снижает рецидивы рака мочевого пузыря на 22%. В настоящее время иммунотерапия БЦЖ остается наиболее эффективным методом лечения и профилактики переходно-клеточного рака мочевого пузыря (Та, Т1, карциномы in situ): позволяет уменьшить количество рецидивов опухоли, прогрессирование заболевания на 34%

The presence of detrusor histological material after transurethral resection for non-muscle-invasive bladder cancer

At identification of a superficial cancer of a bladder with the medical and diagnostic purpose, the first stage TUR on the basis of which the stage of process is established is carried out and the further plan of treatment of a disease is formed. In a type of various characteristics of tumoral process, depth of surgical intervention is changeable as, at the small sizes of a tumor the resection can be executed by the uniform block and it doesn't contradict EORTS recommendations, at the same time at formations of the big sizes the stage-by-stage resection of acting part of a tumor, and then and the tumor basis is carried out. One of important points allowing to judge risk of recurrence of a disease is presence of a muscular wall at a remote material at histologic research. Thus, such sign as, existence or lack of a muscular wall at histologic research, can is a predictor of risk of recurrence of a disease of a cancer of a bladder.При выявлении немышечноинвазивного рака мочевого пузыря с лечебно-диагностической целью первым этапом выполняется трануретральная резекция, на основании которой проводится стадирование процесса и составляется дальнейший план лечения заболевания. В виду различных характеристик опухолевого процесса глубина хирургического вмешательства является непостоянной, так как, при размерах опухоли около 5 мм резекция может быть выполнена единым блоком и это не противоречит рекомендациям E0RTS, в то же время при образованиях больших размеров выполняется поэтапная резекция экзофитного компонента, а затем и основания опухоли. Одним из важных моментов позволяющем судить о риске рецидива заболевания является присутствие детрузора в удалённом материале при патаморфологическом исследовании. Таким образом, такой признак как, наличие или отсутствие детрузора при гистологическом исследовании, может является предиктором риска рецидива заболевания рака мочевого пузыря

Анализ клеточного состава нативной трансплантационной аутосмеси, используемой для пластики дефектов костной ткани

The cell composition of native transplant autosmes (NTA) used for bone plastics was studied. The histological examination showed the fragments of bone beams with preserved osteoblasts, the foci of myeloid and lymphoid hematopoiesis and the fibrin deposits, which suggested the presence of MMSCs. Immunophenotyping of the NTA cell population revealed a high level of expression of the surface markers CD105, CD73, and CD90 characteristic for MMSC. DNA-flow cytometry of the bone dust confirmed almost complete preservation of graft viability on the 3rd day of culturing (97.7 % of live cells). The data of this study confirm the presence of the osteogenic, osteoinductive, and osteoconductive properties of the bone dust and emphasize the importance of a further study of this-type bone graft for use in surgical interventions.Проведено исследование клеточного состава нативной трансплантационной аутосмеси (НТА), используемой для костной пластики. Гистологическое исследование показало фрагменты костных балок с сохранившимися остеобластами, очаги миелоидного и лимфоидного кроветворения и отложения фибрина, что позволило предположить наличие мультипотентных мезенхимальных стромальных клеток (ММСК). При имммунофенотипировании популяции клеток НТА выявлен высокий уровень экспрессии поверхностных маркеров CD105, CD73 и CD90, характерных для ММСК. ДНК-проточная цитофлоурометрия костной аутосмеси подтвердила практически полное сохранение жизнеспособности трансплантата на третьи сутки культивирования (97,7 % живых клеток). Полученные данные свидетельствуют о наличии у нативной трансплантационной аутосмеси остеогенных, остеоиндуктивных, остеокондуктивных свойств и обосновывают дальнейшее ее исследование с целью использования в качестве аутотрансплантата при хирургических вмешательствах

Lactate dehydrogenase-5 (LDH-5) overexpression in non-small-cell lung cancer tissues is linked to tumour hypoxia, angiogenic factor production and poor prognosis

Lactate dehydrogenase-5 (LDH-5) catalyses the reversible transformation of pyruvate to lactate, having a principal position in the anaerobic cellular metabolism. Induction of LDH-5 occurs during hypoxia and LDH-5 transcription is directly regulated by the hypoxia-inducible factor 1 (HIF1). Serum LDH levels have been correlated with poor prognosis and resistance to chemotherapy and radiotherapy in various neoplastic diseases. The expression, however, of LDH in tumours has never been investigated in the past. In the present study, we established an immunohistochemical method to evaluate the LDH-5 overexpression in tumours, using two novel antibodies raised against the rat muscle LDH-5 and the human LDH-5 (Abcam, UK). The subcellular patterns of expression in cancer cells were mixed nuclear and cytoplasmic. In direct contrast to cancer cells, stromal fibroblasts were reactive for LDH-5 only in a minority of cases. Serum LDH, although positively correlated with, does not reliably reflect the intratumoral LDH-5 status. Lactate dehydrogenase-5 overexpression was directly related to HIF1alpha and 2alpha, but not with the carbonic anhydrase 9 expression. Patients with tumours bearing high LDH-5 expression had a poor prognosis. Tumours with simultaneous LDH-5 and HIF1alpha (or HIF2alpha) overexpression, indicative of a functional HIF pathway, had a particularly aggressive behaviour. It is concluded that overexpression of LDH-5 is a common event in non-small-cell lung cancer, can be easily assessed in paraffin-embedded material and provides important prognostic information, particularly when combined with other endogenous markers of hypoxia and acidity