bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of fibroblast growth factors and their receptors during full-thickness skin wound healing in young and aged mice
Authors: Komi-Kuramochi Akiko , Kawano Mitsuko , Oda Yuko , Asada Masahiro , Suzuki Masashi , Oki Junko , Imamura Toru
Published: August 2005

The highly ordered process of wound healing involves the coordinated regulation of cell proliferation and migration and tissue remodeling, predominantly by polypeptide growth factors. Consequently, the slowing of wound healing that occurs in the aged may be related to changes in the activity of these various regulatory factors. To gain additional insight into these issues, we quantified the absolute copy numbers of mRNAs encoding all the fibroblast growth factors (FGFs), their receptors (FGFRs) and two other growth factors in the dorsal skin of young and aged mice during the healing of full-thickness skin excisional wounds. In young adult mice (8 weeks old), FGF7, FGF10 and FGF22 mRNAs were all strongly expressed in healthy skin, and levels of FGF7 and 10 but not 22 increased 2- to 3.5-fold over differing time courses after wounding. The levels of FGF9, 16, 18 and especially 23 mRNAs were moderate or low in healthy skin but increased 2- to 33-fold after wounding. Among the four FGFRs, expression of only FGFR1 mRNA was augmented during wound healing. Expression of transforming growth factor-β and hepatocyte growth factor was also high in healthy skin and was upregulated during healing. Notably, in aged mice (35 weeks old), where healing proceeded more slowly than in the young, both the basal and wound-induced mRNA expression of most of these genes was reduced. While these results confirm the established notion that FGFR2 IIIB ligands (FGF7 and FGF10) are important for wound healing, they also suggest that decreased expression of multiple FGF ligands contributes to the slowing of wound healing in aged mice and indicate the potential importance of further study of the involvement of FGF9, 16, 18 and 23 in the wound healing process.
Effects of immunoregulatory drugs on human peripheral blood T lymphocytes function in vitro
Authors: Hatzistilianou Marija , Hitoglou Soultana , Gougoustamou Despina , Kotsis Alexandros , Kallinderes Athanasios , Athanassiadou Fanni , Catriu Dorothea
Published: August 2005

BACKGROUND: The purpose of the study was to evaluate the mode of action of different immunoregulatory drugs in lymphocyte proliferation and activation METHODS: The drugs studied were prednisolone (PRED), cyclosporin A (CsA) the recombination of PRED and CsA, L-asparaginase and cytosine-arabinose (ara-C). Peripheral blood lymphocytes from normal blood donors were stimulated by phytohemagglutinin (PHA). Lymphocytes proliferation and activation were determined by tritiated thymidine ([3H]TdR) incorporation secretion of interleukin-2, level of soluble interleukin-2 receptors in the supernatant of the culture medium, and immunophenotyping analysis of T lymphocyte subsets. RESULTS: Among PRED CsA and their combination, the strongest inhibition of cell proliferation was induced by PRED while L-asparaginase and ara-C inhibited PHA stimulated T cells proliferation in concentration and time dependent manner. Among PRED, CsA and their combination, CsA induced the greatest inhibition of IL-2 production. All the immunoregulatory drugs inhibited lymphocyte proliferation and expression of activation antigens. CONCLUSION: The immunoregulatory drugs inhibit both lymphocyte proliferation and activation but in a different way.
Prevention and treatment of secondary lymphedema of the arm in breast cancer patients
Authors: Popovic-Petrovic Svetlana , Vasovic Milka , Nedeljkovic Miroslav
Published: August 2005

A program of early postoperative rehabilitation (kinesy therapy and education) has been conducted since 1996 in our Department for Rehabilitation at the Institute of Oncology in Sremska Kamenica. The aim of this program is to prevent the appearance of secondary lymphedema of the arm and the contacture of the shoulder. Unless the patient, in further follow up, does not have any complication, a program of "late" rehabilitation is conducted. If secondary lymphedema of the arm (SLEA) is evolved, then the patient is submitted to a complex of decongestive physical therapy (CDP) or CDP and sequential pneumatic compression (SEPC). However if SLEA and local alterations on the skin exist, we immobilize the arm (mitela, plaster). In other cases without SLEA, e.g. periarthritis or the damage of brachial plexus, we perform physical procedures (kinesy therapy TENS, kryo-massage and acupuncture). With regard to the degree of complication of SLEA and consequences that might develop the starting point should be directed towards early detection of SLEA.
Rectal dosimetry in intracavitary applications of cervix carcinoma: Comparison of two methods
Authors: Baucal Milutin , Babic Jovan , Kuzmanovic Zoran
Published: August 2005

BACKGROUND: Brachytherapy of cervix carcinoma often results in high doses to surrounding structures, such as rectum and bladder. Therefore, these organs should be closely monitored. Purpose of this work was to evaluate rectal marker made in our institution for rectal dose measurements by comparing it with the method recommended in ICRU (International Commission on Radiation Units and Measurements) Report 38. METHODS: In this work rectal dosimetry was performed by two different methods. In one, rectal marker made in Institute of Oncology Sremska Kamenica was used, while in the other method recommended in ICRU Report 38 dose on ICRU rectal point was measured A total of 34 applications using Microselectron HDR and its standard applicator set were performed in a prospective way. The prescribed dose was 7.6 Gy to point A for each application. Rectal doses were calculated by Nucletron Plato Treatment Planning System. RESULTS: Differences found between the means of ICRU point R and rectal marker points Rref and Rmax were significant (P<0.002 and P<0.00002). The same result was obtained for Rref and Rmax pair (P<0.003). CONCLUSION: Maximal doses obtained using rectal marker were in most cases high- er than those obtained by ICRU method. It conforms well to several CT-based dosimetry studies where rectum dose was found to be higher from that obtained by ICRU method.
Intravascular large cell lymphoma: Clinicopathological and immunohistochemical description of a case
Authors: Dozic Branko , Cvetkovic Dubravka , Dozic Marko , Bumbasirevic Ljiljana
Published: August 2005

A 51-year-old female patient was admitted to the Neurological clinic because of motor seizures with myoclonus of the right hand and right side of the face. The results of initial brain CT scan, chest X rays, EEG ultrasonography of the great blood vessels and laboratory tests made in another hospital were unremarkable. Because of repeated partial seizures transient aphasic disturbances, urinary sphincter disturbances and periodic low-grade fever the patient was transferred to our hospital four months after the disease onset. Laboratory tests and NMR suggested a nonspecific disseminated viral encephalitis. After administration of Endoxan she was ambulatory for several weeks and then became increasingly exhausted confused, febrile, dyspneic, tachypneic and developed a shock status with hepatorenal insufficiency. She died after 7 months of disease duration. Postmortem examination revealed intravascular collections of large atypical lymphoid cells of B cell line. Blood vessels changed in this way were common in the brain and rare in other organs including skin, lungs, heart, liver spleen and digestive system. They were not found in the lymph nodes and bone marrow. A biopsy was not done because of absence of symptomatic and swollen tissues. However, correlation of clinical feature and postmortem findings shows that absence of clinical manifestations in an organ does not mean lack of microscopic pathological changes and biopsy should be done regardless of absence of clinical signs. This case shows that intravascular lymphoma may mimic vasculitis or disseminated nonspecific viral encephalitis.
Principles of surgery for thyroid carcinoma
Authors: Dzodic Radan , Markovic Ivan , Inic Momcilo , Milovanovic Zorka , Jovanovic Nikola
Published: August 2005

Surgery is the initial therapy in thyroid carcinoma. The basic principles of surgical oncology in malignant epithelial tumors have their full improvement in thyroid carcinoma (TC). The surgery is performed on organ of tumor origin and regional lymphatic basins. The aim of surgery in thyroid carcinoma is to eradicate all tumor foci, cure the most number of patients, reduce recurrence and mortality rate, and provide good quality of life. There is no doubt between oncologists that the surgery for thyroid carcinoma has no alternative. The extent of surgery is matter of actual controversies. Surgery is the initial treatment for all differentiated, papillary and follicular, as well as medullary and even anaplastic thyroid carcinoma. It should be performed by well-trained surgeons. The surgery of thyroid gland is the surgery of laryngeal recurrent nerve and parathyroid glands. The extent of primary surgery should be dictated by stage of disease and prognostic factors. The quality of surgery and incidence of complications depends on surgeon's skill and experience. That is why the surgeon is factor of prognosis in treatment of patients with TC.
The action of ionizing irradiation alone or in combination with cisplatin on malignant cells: Investigations in vitro
Authors: Juranic Zorica , Colakovic Slobodanka , Saric Milan , Cikaric Slobodan
Published: August 2005

The paper gives a brief review of the literature data based on in vitro investigations of cytotoxic action of cisplatin and irradiation, applied alone or in combination, to carcinoma cell lines and fresh tumor explants. Presented data, observed in the light of data obtained in clinics, indicate that in vivo some additional tumor destructive activity might be induced by applied therapy. Therefore examinations of the antitumor effect of some treatment need to be more complex and must include determination of the effects of applied therapy on set of parameters, which control tumor growth in vivo.
An overview of Regional training course on therapeutic nuclear medicine
Authors: Rajic Milena
Published: August 2005

Regional training course on therapeutic nuclear medicine was held in Romania in 2002, in the organization of International Atomic Energy Agency. The program covered several topics from oncology, with great attention paid to the treatment of differentiated thyroid cancer, lymphoma, inoperable hepatocellular carcinoma, neuroendocrine tumors and bone pain caused by metastases. Usage of new radionuclides was also promoted with the aim to improve therapy with open sources of radioactivity. Particular attention was paid to the outcome of high and small dose of radioactive iodine (131I) for remnant ablation, to the use of recombinant human TSH in postoperative follow-up, and to radionuclide therapy for non-iodine concentrating thyroid cancers. A new radiopharmaceutical, 188Re (188rhenium)-lipiodol, already used to treat 30 patients, was promoted and pointed to developing of other radioagents for the cure of inoperable hepatocellular carcinoma. Because the treatment of lymphoma with radiolabeled antibodies was proved as successful it was noted that approach could become an important part of therapeutic nuclear medicine over the next couple of years. Targeting therapy for bone pain palliation was shown as relatively cheap and successful, but future possibilities should integrate the use of bone-seeking radiopharmaceuticals at an earlier stage in patients at high risk for developing metastases to avoid their occurrence. This training course pointed out some new radiopharmaceuticals and radionuclides, which predict a further rapid development of therapeutic nuclear medicine and its deeper integration in protocols for the treatment of patients with malignant diseases.
Case-control studies on residential radon and lung cancer: A concise review
Authors: Bochicchio Francesco
Published: August 2005

The risk estimates for the general population extrapolated from the risk obtained from the miner studies leaded many national and international health organizations to estimate that residential exposure to radon and its decay products can be considered one of the main lung cancer risks after the tobacco smoking, which is responsible of a very large fraction of the total number of lung (and other) cancers. Due to this health relevance and to uncertainties in the extrapolation from studies on miners, many residential case-controls studies have been conducted in Europe, North America and China, are shortly reviewed in this paper. Most of these studies estimated an increased risk, proportional to the radon expo- sure, although a statistical significance of the estimated risk was reached only in few studies or restricted analyses, due to the low statistical power related to the relatively small study size and the presence of not negligible uncertainties in the evaluated radon exposure. The effects of these uncertainties were analyzed in some studies, and it was estimated to reduce the risk by 50% to 100%. Moreover, some restricted analyses showed that selecting subjects with a presumably better evaluation of radon exposure, for example with radon measurement covering all the exposure period of interest, the estimated risk increases by a factor of about two. The use of retrospective dosimetry compared with contemporary radon concentration measurements produce higher risks, too. In most of the studies a multiplicative interaction between tobacco smoking and radon is suggested, which implies that the lung cancer risk due to radon exposure is much higher for a smoker, compared with the risk for a never-smoker. More precise and definitive results are expected from pooled analysis. The just published pooled analyses of two Chinese studies and seven North American estimate a (slightly) significant excess odds ratio of 14% and 11% respectively. A more precise and comprehensive assessment is expected from the forthcoming results of the European pooling of 13 studies and the following pooling of all the studies. Other studies will be probably needed to answer some question on the risk for never-smokers and the interaction with passive smoking.
Postoperative radiotherapy after conservative surgery for early breast cancer: 5-year results
Authors: Mladenovic Jasmina , Dozic Marko , Borojevic Nenad
Published: August 2005

BACKGROUND: Breast conserving surgery followed by postoperative radiotherapy, as alternative to radical mastectomy, has been accepted as an optimal method for loco- regional treatment of the majority of women with early stage of breast carcinoma. The aim of the study was to evaluate the results of postoperative radiotherapy after breast conserving surgery in the Institute for oncology and radiology of Serbia. METHODS: During the 3-year period, 109 breast cancer patients with stage I and II were treated with postoperative radiotherapy after breast conserving surgery. Ninety- four patients underwent quadrantectomy with axillary node dissection, and 15 patients underwent only tumorectomy. After surgery all patients received postoperative radiotherapy to the whole breast with tumor dose 50 Gy in 15 fractions every second day. In 52 patients radiotherapy was given to the regional lymphatics with tumor dose 45 Gy in 15 fractions every second day. Twenty-eight patients received a booster dose (10 Gy) to the tumor bed. Adjuvant systemic therapy was administered depending on the nodal involvement and steroid receptors content: 17 patients received adjuvant chemotherapy (CMF or FAC), 18 received adjuvant hormonal therapy (tamoxifen or ovarian ablation), and 6 patients received both chemo- and hormonotherapy. RESULTS: After median follow-up period of 62 months, there was no evidence of loco- regional recurrence in anyone of patients. Distant metastases occurred in 7 patients (6.4%) with median disease free interval of 27.6 months. At last follow-up 91 patients (83.4%) were alive, 4 patients (3.7%) were dead of disease, and the same number was dead of other causes. The 5-year overall survival rate was 92.9% and disease-free survival rate was 92.7%. CONCLUSION: According to our results the combined surgery and radiotherapy approach provides good local control of early breast cancer patients. Postoperative radiotherapy after breast conserving surgery with or without adjuvant systemic therapy has important role in adjuvant treatment of early breast cancer.
Cancer gene therapy
Authors: Mitrovic Tatjana , Radulovic Sinisa
Published: August 2005

Cancer gene therapy can be defined as transfer of nucleic acids into tumor or normal cells with aim to eradicate or reduce tumor mass by direct killing of cells, immunomodulation or correction of genetic errors, and reversion of malignant status. Initially started with lots of optimism and enthusiasm, cancer gene therapy has shown limited success in treatment of patients. This review highlights current limitations and almost endless possibilities of cancer gene therapy. The major difficulty in advancing gene therapy technology from the bench to the clinical practice is problem with gene delivery vehicles (so called vectors) needed to ferry genetic material into a cell. Despite few reports of therapeutic responses in some patients, there is still no proof of clinical efficacy of most cancer gene therapy approaches, primarily due to very low transduction and expression efficacy in vivo of available vectors. An "ideal" gene therapy vector should be administrated through a noninvasive route and should be targeted not only to primary tumor mass but also to disseminated tumor cells and micrometastases; it should also carry therapeutic gene with tumor-restricted, time-regulated, and sustained expression. Current strategies for combating the cancer with gene therapy can be divided into four basic concepts: (1) replacement of missing tumor suppressor gene and/or blocking of oncogenes or pro-inflammatory genes, (2) suicide gene strategies, (3) induction of immune-mediated destruction, and (4) inhibition of tumor angiogenesis. The advance in the clinical benefit of gene therapy will probably be first achieved with combining it with standard cancer treatment: chemotherapy, radiotherapy, and immunotherapy.
The zonal satellite problem. III Symmetries
Authors: Mioc V.
Published: August 2005

The two-body problem associated with a force field described by a potential of the form U =Sum(k=1,n) ak/rk (r = distance between particles, ak = real parameters) is resumed from the only standpoint of symmetries. Such symmetries, expressed in Hamiltonian coordinates, or in standard polar coordinates, are recovered for McGehee-type coordinates of both collision-blow-up and infinity-blow-up kind. They form diffeomorphic commutative groups endowed with a Boolean structure. Expressed in Levi-Civita?s coordinates, the problem exhibits a larger group of symmetries, also commutative and presenting a Boolean structure.
The plasma-solid transition: some implications in astrophysics
Authors: Celebonovic Vladan , Dappen W.
Published: August 2005

Using a criterion proposed by Salpeter and standard solid-state physics, we have determined the Debye temperature of a solid in equilibrium with the electron gas surrounding it. The results obtained can have astrophysical applications in the determination of parameters of interstellar and interplanetary clouds.
On the application of a particular form of the gravitational potential
Authors: Ninkovic Slobodan
Published: August 2005

A formula, already existing in the literature, describing the gravitational potential of a spherically symmetric stellar system is analyzed. Some interesting cases of comparison with empirical formulae are presented. A good agreement is found.
How many universes are necessary for an ice cream to melt?
Authors: Cirkovic Milan
Published: August 2005

We investigate a quantitative consequence of the Acausal-Anthropic approach to solving the long-standing puzzle of the thermo dynamical arrow of time. Notably, the size of the required multiverse is estimated on the basis of the classical Boltzmann connection between entropy and probability, as well as the thermodynamic properties of black holes.
The astronomer - N. N. Donitch
Authors: Baikov A.A. , Gaina A.
Published: August 2005

This paper describes a history of friendship and collaboration between the astronomers N. Donitch and A.A. Baikov. Information on other astronomers L.V. Okulitch and E.A. Von der Pahlen, and meteorologists V.H. Dubinskii and Nina Gouma, can also be found. Details on the expeditions aimed at observing the total solar eclipses on 30 August 1905 (organized by the Imperial Academy of Sciences in Sankt-Petersburg) and 19 June 1936 (organized by the Romanian Royal Cultural foundation) are given. The main part represents the first English translation of the paper by Baikov, published earlier in Russian and Romanian, with a new preface, annotations, and comments.
Spiral soliton solution for disk galaxies
Authors: Savkovic Miroslava , Yoshida Z.
Published: August 2005

In this paper, weakly nonlinear dynamics of spiral galaxies is studied, using reductive perturbation method. One primarily aims at the derivation of possible soliton solution for two dimensional geometry, in the state of marginal stability. In order to use proper coordinate transformation, it was necessary to analyze stability of the linearized system of equations, and to define proper parameter regime. Such parameter regime is in agreement with the observational data, too. The influence of finite-thickness of the galaxy disk on dispersive properties of the system is studied, extending approximate solution of Poisson?s equation. For both cases, infinitesimally thin disk and disk of finite thickness, the same type of NLS equation is derived, but with different coefficients for nonlinear and dispersive terms. This means that corresponding soliton solutions have different properties. By comparing soliton properties with observational data it is possible to control validity of approximation for different geometry of the model.
On determination of the cosmic ray flux using molecular hydrogen absorption lines
Authors: Cirkovic Milan , Damjanov I.
Published: August 2005

We outline a procedure for estimating the cosmic ray flux at remote locations where molecular hydrogen absorption lines have been detected. The method relies on several assumptions whose validity in the local Galactic ISM has been independently verified, so it might be useful for much less accessible objects, especially damped Ly? absorption systems. Since most of low-energy cosmic rays in the Galactic environment are thought to originate in supernovae remnants, the link to the rate of high-mass star formation could in principle, be established. We applied the method to a particular case of high redshift damped Ly? absorption system towards 0528?250 and obtained an estimate of proton density and some useful constraints.
Collision dynamics in Hénon-Heiles’ two-body problem
Authors: Mioc V. , Barbosu M.
Published: August 2005

We tackle the two-body problem associated to H?non-Heiles? potential in the special case of the collision singularity. Using McGehee-type transformations of the second kind, we blow up the singularity and replace it by the collision manifold Mc pasted on the phase spece. We fully describe the flow on Mc. This flow is similar to analogous flows met in post-Newtonian two-body problems.
Dynamics of quadruple system Finsen 332 = ADS 11640 = HIP 92027 = WDS 18455+0530
Authors: Olevic Dragomir , Cvetkovic Zorica
Published: August 2005

In 1829 Struve discovered a double star denoted as STF 2375 AB later on. Its separation was 2". 2. It was noticed by Finsen from the Southern Observatory (Johannesburg) in 1953 that the components A and B are close binaries with separations about 0".15. The motion within this quadruple system - FIN 332 Aa and FIN 332 Bb - has been monitored from that time on. The data about the motion of these close binaries are analyzed by the present authors and the preliminary orbital elements are calculated for each of them. The dynamical parallax from the obtained period and the semi major axis for pair FIN 332 Bb agrees completely with that obtained from the Hipparcos program. In the case of FIN 332 Aa a somewhat higher parallax but within the error limits following from the errors of the period and semimajor axis, is obtained and it agrees with the parallax for FIN 332 Bb. The dynamical masses for the components of both systems are as expected for their spectral type A1V (all of them belong to the Main Sequence and here one uses Angelov?s (1993) relation). According to our results, the motion of both systems takes place approximately in the same plane, confirming thus some general properties already noticed in the case of multiple stars.
Determination of metallicity of the HR7914 solar-like star
Authors: Vince Oliver , Vince Istvan
Published: August 2005

By using the Blackwell program package by R.O. Gray, the metallicity of the HR7914 solar-like star was determined. The program package utilizes measured equivalent widths of several chosen neutral iron spectral lines from the observed spectra, appropriate atomic and spectral line parameters and adequate Kurucz?s stellar atmosphere models. The method is based on determination of the minimum dispersion of the iron abundance versus microturbulent velocity functions for the selected neutral iron spectral lines. The spectra were observed at National Astronomical Observatory Rozhen (NAO Rozhen), Bulgaria, using the 2m-telescope and Coude spectrograph. They were reduced with the IRAF program package. The measurement of the spectral line parameters was done with the SPE program package. The metallicity of the HR7914 solar-like star was determined to be 0.02.
Instrumental profile of the Debrecen solar spectrograph
Authors: Murakezi J. , Vince Istvan , Ludmanj A.
Published: August 2005

The solar spectrograph of the Heliophysical Observatory at Debrecen, Hungary was investigated to determine its instrumental profile. The measurements were made by using a HeNe laser beam. The widths and asymmetries of the profiles decrease toward higher spectral orders, the most advantageous orders being the third and the fourth ones. To eliminate the broadening of solar lines on account of the instrumental profile, the straightforward iteration method of Gurtovenko has been applied. The efficiency of the method is demonstrated by the simulation of the broadened and corrected spectral line profiles.
A comparison of two mass distributions applicable to globular clusters and dwarf galaxies
Authors: Ninkovic Slobodan
Published: August 2005

A particular case of mass distribution in stellar systems, already described in the literature, is compared to the King model of mass distribution. For the cases which would correspond to the description of real stellar systems such as the globular clusters and dwarf galaxies, one finds a satisfactory agreement between these two mass distributions.
Is the "Star trek" concept of aliens really naive?: A comment on Duric and Field
Authors: Cirkovic Milan
Published: August 2005

Several assumptions used in the recent review paper on the search for extraterrestrial intelligence (SETI) by Duric and Field (2003) are critically discussed. New astrobiological results-in particular those on the age distribution of terrestrial planets-enable relaxing of some of these assumptions, which gives further justification to optimism regarding SETI projects.
On radiative transfer problems and their solution
Authors: Atanackovic-Vukmanovic Olga
Published: August 2005

A survey of the main stages in the solution of radiative transfer (RT) problems is given with special emphasis on recent approaches and powerful numerical techniques developed to solve non-LTE RT problems.
Structure formation cosmic rays: Identifying observational constraints
Authors: Prodanovic T. , Fields B.D.
Published: August 2005

Shocks that arise from baryonic in-fall and merger events during the structure formation are believed to be a source of cosmic rays. These "structure formation cosmic rays" (SFCRs) would essentially be primordial in composition, namely, mostly made of protons and alpha particles. However, very little is known about this population of cosmic rays. One way to test the level of its presence is to look at the products of hadronic reactions between SFCRs and the ISM. A perfect probe of these reactions would be Li. The rare isotope Li is produced only by cosmic rays, dominantly in ?? ? 6Li fusion reactions with the ISM helium. Consequently, this nuclide provides a unique diagnostic of the history of cosmic rays. Exactly because of this unique property is Li affected most by the presence of an additional cosmic ray population. In turn, this could have profound consequences for the Big-Bang nucleosynthesis: cosmic rays created during cosmic structure formation would lead to pre-Galactic Li production, which would act as a "contaminant" to the primordial 7Li content of metalpoor halo stars. Given the already existing problem of establishing the concordance between Li observed in halo stars and primordial 7Li as predicted by the WMAP, it is crucial to set limits to the level of this "contamination". However, the history of SFCRs is not very well known. Thus we propose a few model-independent ways of testing the SFCR species and their history, as well as the existing lithium problem: 1) we establish the connection between gamma-ray and Li production, which enables us to place constraints on the SFCR-made lithium by using the observed Extragalactic Gamma-Ray Background (EGRB); 2) we propose a new site for testing the primordial and SFCR-made lithium, namely, low-metalicity High-Velocity Clouds (HVCs), which retain the pre-Galactic composition without any significant depletion. Although using one method alone may not give us strong constraints, using them in concert will shed a new light on the SFCR population and possibly give some answers about the pressing lithium problem. .
Adaptationism fails to resolve Fermi's paradox
Authors: Cirkovic Milan , Dragicevic Ivana , Beric-Bjedov Tanja
Published: August 2005

One of the most interesting problems in the nascent discipline of astrobiology is more than half-century old Fermi's paradox: why, considering extraordinary young age of Earth and the Solar System in the Galactic context, don't we perceive much older intelligent communities or signposts of their activity? In spite of a vigorous research activity in recent years, especially bolstered by successes of astrobiology in finding extrasolar planets and extremophiles, this problem (also known as the "Great Silence" or "astrosociological" paradox) remains as open as ever. In a previous paper, we have discussed a particular evolutionary solution suggested by Karl Schroeder based on the currently dominant evolutionary doctrine of adaptationism. Here, we extend that discussion with emphasis on the problems such a solution is bound to face, and conclude that it is ultimately quite unlikely. .
Differential photometry of EK DRA and 29 DRA
Authors: Zboril M.
Published: August 2005

We report on BVR precise photometry of active late-type stars EK DRA and 29 DRA in the spring of 2004. The analysis suggests a reasonable fit with single spot model for both cases in the season as far as the V-curve is concerned. The spots are generally cooler than surrounding photosphere and are at high latitudes. The maximal brightness changes for both stars implying a non-rotating component of activity signatures, the spots. We expect that the spot configuration is stable over the period of approximately three months. .
Astrometry test of MSCRED IRAF software package
Authors: Popescu R. , Popescu P. , Paraschiv P. , Nedelcu A.
Published: August 2005

Astrometric properties of images obtained using MSCRED IRAF software package are investigated. CCD observations of M35 open cluster were taken in an observation run between October 10 and 17, 2004 at Belogradchick Observatory (Bulgaria) using the 60cm Cassegrain telescope endowed with a 1kX1k Apogee 47P CCD camera, ensuring to a field size of 6.16 square minutes, with a scale of 0.722arcsec/pixel in 2X2 binned mode. Dithered images are resampled and reansambled into a single larger image for which the World Coordinate System (WCS) solution is recomputed and investigated. .
Effect of atmosphere and dopants on sintering of SnO2
Authors: Varela J.A. , Perazolli L.A. , Longo E. , Leite E.R. , Cerri J.A.
Published: August 2005

Tin oxide is an n type semiconductor material with a high covalent behavior. Mass transport in this oxide depends on the surface state promoted by atmosphere or by the solid solution of aliovalent oxide doping. The sintering and grain growth of this type of oxide powder is then controlled by atmosphere and by extrinsic oxygen vacancy formation. For pure SnO2 powder the surface state depends only on the interaction of atmosphere molecules with the SnO2 surface. Inert atmosphere like argon or helium promotes oxygen vacancy formation at the surface due to reduction of SnO2 to SnO at the surface and liberation of oxygen molecules forming oxygen vacancies. As a consequence surface diffusion is enhanced leading to grain coarsening but no densification. Oxygen atmosphere inhibits SnO2 reduction by decreasing the surface oxygen vacancy concentration. Addition of dopants with lower valence at the sintering temperature creates extrinsic charged oxygen vacancies that promote mass transport at the grain boundary leading to densification and grain growth of this polycrystalline oxide.
Kinetics of thermal relaxation of cold sintered amorphous powder of 82Ni18P
Authors: Minic-Popovic Dragica , Maricic Aleksa , Susic N.
Published: August 2005

The process of thermal stabilization of cold sintered amorphous powder of 82Ni18P was studied using the method of measuring the electrical resistance in non-isothermal and isothermal conditions. It was shown that the process of crystallization followed by further structural arrangement occurs in stages in the temperature interval from 623 to 723 K. By measuring the change in electrical resistance at constant temperatures, T1 = 613, T2 = 633 and T3 = 653 K, the kinetic parameters of the process of structural ordering of the evaluated substance were found. It was shown that every stage of crystallization is followed by a decrease in electrical resistance.
The influence of high pressure on the properties of natural alumino-silicates
Authors: Susic N.
Published: August 2005

The effect of the application of high-pressure (up to 12 GPa) on natural alumino-silicates has been studied. Chemical and mineral compositions and thermal behaviour have been analyzed of two samples of alumino-silicates. Results obtained indicate that the application of high pressure causes notable changes. A particularly significant one is the formation of amorphous phases on account of crystalline phases. An amorphous layer formed on particle surfaces with its diverse physical, mechanical, chemical, and other properties, especially over a long period of time, can influence the processes provoking or activating land slides or soil settlements. This enables derivation of many new materials with entirely new properties important for use in the ceramic and brick industries.
Sintering and composition of a powder mixture of fine Al2O3 and beta-sialon composite made from bauxite
Authors: Nan L.I. , Jun Wang
Published: August 2005

The sintering and composition of samples made of powder mixtures consisting of fine a-AI2O3 powder and beta-Sialon composite powder which was made from bauxite by carbonthermal reduction and nitridation were studied. The proportion of fine a-AI2O3 to beta'-Sialon composite powder in the powder mixture and soaking time give influences on porosity and relative density of the samples sintered at 1600eC. AI2O3, 15R and MgO which was added in 2 wt.% to improve sintering of the sample disappeared in the samples made of single P'-Sialon composite powder. They solubilize into beta-Sialon. In the sample made of a powder mixture consiting of 60 wt.% beta'-Sialon composite to 40 wt.% a-AI2O3 with addition of 2 wt.% MgO, beta'-Sialon, ct-AI2O3 and MgAION coexist after sintering at 1600BC.
The effect of ageing on YBa2Cu3O7-x obtained by the photoacoustic method
Authors: Nikolic Pantelija , Radovic-Vasiljevic D. , Radulovic K. , Lukovic D. , Vujatovic S.S. , Djuric S.
Published: August 2005

Thermal diffusivity and electric transport properties of fourteen years old superconducting YBa2Cu3O7-x pellets were obtained using the photoacoustic transmission technique and then compared with freshly made superconducting samples. The theoretical model for photoacoustic (PA) detection configuration is given. The measured amplitude and phase PA signals, as a function of the modulation frequency, were numerically analyzed. The thermal diffusivity, the coefficient of the carrier diffusion, optical absorption coefficient and the excess carrier lifetime were calculated. The thermal diffusivity of freshly produced samples decreased, after ageing, from about 1.3?10-6 to about 6.1?10-7 m2/s.
Electrical and mechanical properties of some high-alumina compositions obtained by the casting process of aqueous suspensions
Authors: Spataru M. , Muntean M.
Published: August 2005

In this paper the choosen material compositions, the manner of preparing and shaping of composites are presented. Measurements of the mechanical resistance and electrical resistivities of cast samples obtained by pouring in plaster moulds are presented comparatively with the same properties obtained on mould samples by other processes.
Mechanically stable insoluble titanium-lead anodes for sulfate electrolytes
Authors: Chmiola J. , Gogotsi Y. , Ferdman A.
Published: August 2005

Different formulations of a new material to be used as an insoluble anode for copper electrowinning, a Ti-Pb composite, were investigated for both mechanical and electrochemical properties. Mechanical and metallographic characteristic tests, as well as short-term deposition tests were used to study the effect of the Ti/Pb ratio on anode performance. Yield strength and elastic modulus, obtained through tensile testing, significantly exceed that of lead. Metallographic procedures were used to assess the uniformity of lead distribution in the material, as well as porosity, which would be decreased below 1 % for most of the compositions under study. Short-term deposition tests were used to determine power consumption, deposit quality current efficiency and weight loss characteristics of the new anode material. The material with only 30 vol.% lead shows approximately the same electrochemical performance as a pure lead anode, but has much higher mechanical properties which prevent warping and extend the lifetime of the anode.
High temperature sintering kinetics of a-Al2o3 powder
Authors: Ivanovic M.R. , Nenezic M. , Jokanovic Vukoman
Published: August 2005

The sintering kinetics of a-Al2O3 powder is investigated in this paper Commercial a-Al2O3 powdered compacts were sintered close to 95 % of the theoretical density. The characteristic parameters of sintering kinetics were also determined.
Synthesis of Ti4O7 magneli phase using mechanical activation
Authors: Gusev A.A. , Avvakumov E.G. , Vinokurova O.B.
Published: August 2005

The processes of phase formation by heating of a mechanically activated mixture of Ti + TiO2 in different atmospheres (air, argon, hydrogen) were investigated. The Ti4O7 compound was obtained by annealing of the mixture in hydrogen atmosphere in the interval of temperatures of 900-1200?C, the Ti2O3 oxide formed at 800?C in argon atmosphere and TiO2 formed in air atmosphere Conductivity and morphology of Ti4O7 samples obtained in hydrogen were studied.
Structural-phase transformations in bentonite after acid treatment
Authors: Vlasova M. , Dominguez-Patiño G. , Kakazey N. , Dominguez-Patiño M. , Juarez-Romero D. , Méndez Enríquez
Published: August 2005

The methods of X-ray diffraction, Fourier transform infra-red spectroscopy (FTIR), X-ray microanalysis, electron microscopy, BET and cation exchange capacity (CEC) were used for investigation of the structural-phase transformations in bentonite under the influence of hydrochloric acid and temperature treatment (100-800?C). It is established that in HCl medium during temperature treatment, dehydration and dehydroxilation of montmorillonite occur. The presence of gypsum and barium chloride results in an intercalation of interlayer space of montmorillonite by Ca and Ba ions Temperature treatment of intercalated montmorillonite leads to the formation of pores.
Thermal conductivity of pressureless sintered silicon nitride materials with LiYO2 additive
Authors: Matovic B. , Rixecker G. , Golczewski J. , Aldinger F.
Published: August 2005

Si3N4 ceramics with different microstructures were prepared by pressureless sintering, using LiYO2 as a sintering additive. The effect of micro structural parameters, such as grain size and volume of intergranular phase on thermal conductivity was studied. Materials with thermal conductivities of 26-38 W?(m?K)-1 were obtained by changing the amount of sintering additive. The highest conductivity was measured for the material with the least amount of additive. Since the phase composition is the same for all sintered materials the difference in thermal conductivity is attributed to the amount of glassy phase in the grain-junctions. .
The effect of temperature on structural changes of NI55CO45 amorphous powder
Authors: Spasojevic M. , Maricic Aleksa , Rafailovic Lidija
Published: August 2005

Cobalt and nickel alloy powders were obtained by electrochemical deposition on a titanium cathode from an ammonium solution of cobalt and nickel sulfate. Powders of a specific chemical structure and composition, particle shape and size were obtained by an appropriate choice of electrolysis parameters, current density, deposit growth rate and solution temperature and composition. Within the current density range of 5 - 450 mAcm-2, the current density did not significantly affect the chemical composition of the powders, but had a significant effect on the particle structure, shape and size. Crystal particles formed at a current density lower than 30 mAcm-2. Amorphous powders were obtained at a current density higher than 50 mAcm-2. Structural changes of the obtained amorphous powder of 55mol.% Ni, 45 mol.% Co, pressed under the pressure of 100 MPa, were investigated by measuring the temperature dependence of electrical resistance in isothermal and non-isothermal conditions varying from room temperature to 750?C. The process of thermal stabilization of defects that appeared during pressing occurred within the temperature range of 200-390?C. The DSC method was used to determine that the powder crystallization process occurred in two stages with peak temperatures of the exothermal maximum in the first and second stage of T1 = 438?C and T2 = 573?C, respectively. A distinct correlation between the change of electrical resistance and the crystallization process was established. The reduction of electrical resistively occurs during each crystallization stage.
Investigation of sintering kinetics of NiO using photo acoustic spectroscopy
Authors: Nikolic M.V. , Lukovic D. , Savic S. , Blagojevic V. , Nikolic Pantelija
Published: August 2005

Sintering kinetics of NiO was investigated using photo acoustic spectroscopy This method was used to follow the change of phase and amplitude of the photo acoustic signal of nickel-oxide samples sintered at 1373 K for 15-240 min. as a function of modulation frequency of the laser beam. Fitting of experimental data enabled determination of photo acoustic properties including thermal diffusivity of sintered nickel-oxide. Analysis of the change of sample density during sintering showed that the sintering process of this material can be observed from the viewpoint of activated volume and the change of thermal diffusivity can be correlated with the change of density of this material.
Sintering AL2O3-CR composites made from micro-and Nan powders
Authors: Pietrzak K. , Chmielewski M. , Włosiński W.
Published: August 2005

This paper presents the results of studies on sintering Al2O3-Cr composites of different chemical compositions (from 25 to 75 vol.% of each component). The factor analyzed was the influence of time (from 15 to 60 min) temperature (from 1200-1600?C), pressure (0.5 and 30 MPa) and powder graining (for Al2O3 powders-80nm or 1?m) on the density of sinters obtained. It was found that Nan powder composites are characterized by a higher density (by about 1-2%) than the micro powder composite, the remaining conditions of the process intact. Using the pressure of 30MPa allows obtaining of a definite sintering degree at a temperature of about 200?C lower than at a pressure of 0.5 MPa.
Stationary transversal hot zones in adiabatic packed‐bed reactors
Authors: Viswanathan G. , Luss D. , Bindal A. , Khinast J.
Published: August 2005

A pseudo‐homogeneous model predicts that a stationary, stable, transversal nonuniform temperature pattern cannot form in any cross section of an adiabatic packed‐bed reactor used to conduct a single reaction, if its dynamics depends only on the concentration of a limiting reactant and temperature. This is due to the fact that the transversal heat dispersion in the reactor is larger than that of the limiting reactant. This conclusion is proved for a shallow packed‐bed reactor described by a pseudo‐homogeneous model. Extensive numerical simulations showed that a two‐phase model of an adiabatic packed‐bed reactor exhibits the same behavioral features. A stable, stationary hot zone can form in the cross section of the reactor only under the unrealistic assumption that the transversal species dispersion exceeded that of the temperature. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Association of malignant disease with critical leg ischaemia
Authors: El Sakka K , Gambhir R P S , Halawa M , Chong P , Rashid H
Published: August 2005

Background

The aim of the study was to determine the prevalence of malignant disease in patients with critical leg ischaemia (CLI).

Methods

Data for all patients with CLI presenting to a tertiary vascular unit over an 18-month interval were collected prospectively. Patients with clinical, laboratory or radiological features suggestive of malignancy were evaluated further.

Results

Of 192 patients admitted with CLI, 22 (11·5 per cent) were found to have an associated malignancy; ten had lung cancer. Fifteen were anaemic on presentation. The prevalence of occult malignancy in patients with acute leg ischaemia was 16 per cent (ten of 62) compared with 9·2 per cent (12 of 130) in those with chronic CLI. Eleven of 22 of patients with CLI and malignancy died within 6 months, compared with 35 (20·6 per cent) of 170 patients with no evidence of malignancy.

Conclusion

A high prevalence of occult cancer was found in patients presenting with CLI; this was associated with a significantly increased mortality rate at 6 months.
Coating of Energetic Materials using Crystallization
Authors: Kim K.‐J. , Kim H.‐S.
Published: August 2005

A sensitive explosive was coated with a less sensitive explosive in order to improve stability while maintaining explosion performance. In this study the sensitive explosive HMX was coated with the less sensitive explosive NTO (3‐nitro‐1, 2, 4‐triazole‐5‐one) by cooling crystallization. The mechanism of coating by crystallization was determined to be an agglomeration and crystal growth phenomenon. The surface morphology and the growth rate of the coating were investigated under various experimental conditions. The surface morphology was predominantly influenced by the solvent type, HMX/NTO ratio, agitation speed, and degree of sub‐cooling. The growth rate of the HMX coating was increased to a certain extent by increasing the concentration ratio of HMX/NTO, but then began to decrease because of high agglomeration. Finally, the optimal conditions to achieve thin and uniform surface coatings on HMX were found experimentally.