Crystal structures of 5-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II) and Zn(II)

The crystal and molecular structures of [bis(5-chloro-2-methoxybenzoate)tetraaquamanganese(II)], [pentaaqua(5-chloro-2-methoxybenzoato)cobalt(II)] (5-chloro-2-methoxybenzoate), [pentaaqua(5-chloro-2-methoxybenzoato)nickel(II)] (5-chloro-2-methoxybenzoate) and [aquabis(5-chloro-2-methoxybenzoate)zinc(II)] monohydrate were determined by a single-crystal X-ray analysis. Mn(H2O)4L2 (where L = C8H6ClO3) crystallizes in the monoclinic system, space group P21/c. [Co(H2O)5L]L and [Ni(H2O)5L]L both are isostructural, space group P212121. The crystals of [Zn(H2O)L2] H2O are monoclinic, space group Pc. Mn(II) ion is positioned at the crystallographic symmetry center. Mn(II) and Co(II) ions adopt the distorted octahedral coordination but Zn(II) tetrahedral one.The carboxylate groups in the complexes with M(II) cations function as monodentate, bidentate and/or free COO-groups. The ligands exist in the crystals as aquaanions. The complexes of 5-chloro-2-methoxybenzoates with Mn(II), Co(II) and Zn(II) form bilayer structure.

Thermal and spectral properties of di-and trimethoxybenzoates of silver (I)

The complexes of silver(I) with 2,3-, 2,4-, 2,6-, 3,4-, 3,5-dimethoxy-, and 2,3,4- and 3,4,5-trimethoxybenzoic acid anions have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric and X-ray studies. Their solubility in water has been also determined at 293K. All analysed complexes were found to be crystalline, anhydrous compounds with low symmetry. The carboxylate groups act as bidentate or monodentate ligands. The thermal stability of compounds has been examined in air in temperature range of 293-1173K. The analysed complexes were found to be stable at room temperature and their solubilities in water at 293K to be in the order of 10-4 mol.dm-3.

Quasiclassical Approach to the Vortex State in Iron-based Superconductors

The quasiclassical approach was applied to the investigation of the vortex properties in the ironbased superconductors. The special attention was paid to manifestation of the nonlocal effects of the vortex core structure. The main results are as follows: (i) The effects of the pairing symmetries (s+ and s₊₊) on the cutoff parameter of field distribution, ξh, in stoichiometric (like LiFeAs) and nonstoichiometric (like doped BaFe₂As₂) iron pnictides have been investigated using Eilenberger quasiclassical equations. Magnetic field, temperature and impurity scattering dependences of ξh have been calculated. Two opposite behavior have been discovered. The ξh /ξc2 ratio is less in s+ symmetry when intraband impurity scattering (Γ₀) is much larger than one and much larger than interband impurity scattering (Γπ), i.e. in nonstoichiometric iron pnictides. Opposite, the value ξh /ξc2 is higher in s+ case and the field dependent curve is shifted upward from the "clean" case (Γ₀ = Γπ = 0) for stoichiometric iron pnictides (Γ₀ = Γπ ≪ 1). (ii) Eilenberger approach to the cutoff parameter, ξh, of the field distribution in the mixed state of high

Jatkuvan äänitehojakautuman algoritmi pitkien käytävien äänikenttien mallintamiseen

JÄKÄLA-algoritmi (Jatkuvan Äänitehojakautuman algoritmi Käytävien Äänikenttien LAskentaan) ja sen NUMO- ja APPRO-laskentayhtälöt perustuvat käytävällä olevan todellisen äänilähteen kuvalähteiden symmetriaan. NUMO on algoritmin numeerisen ratkaisun ja APPRO likiarvoratkaisun laskentayhtälö. Algoritmia johdettaessa oletettiin, että absorptiomateriaali oli jakautunut tasaisesti käytävän ääntä heijastaville pinnoille. Suorakaiteen muotoisen käytävän kuvalähdetason muunto jatkuvaksi äänitehojakautumaksi sisältää kolme muokkausvaihetta. Aluksi suorakaiteen kuvalähdetaso muunnetaan neliön muotoiseksi. Seuraavaksi neliön muotoisen kuvalähdetason samanarvoiset kuvalähteet siirretään koordinaattiakselille diskreetiksi kuvalähdejonoksi. Lopuksi kuvalähdejono muunnetaan jatkuvaksi äänitehojakautumaksi, jolloin käytävän vastaanottopisteen äänenpainetaso voidaan laskea integroimalla jatkuvan äänitehojakautuman yli. JÄKÄLA-algoritmin validiteetin toteamiseksi käytettiin testattua kaupallista AKURI-ohjelmaa. AKURI-ohjelma antoi myös hyvän käsityksen siitä, miten NUMO- ja APPRO-yhtälöillä lasketut arvot mahdollisesti eroavat todellisilla käytävillä mitatuista arvoista. JÄKÄLA-algoritmin NUMO- ja APPRO-yhtälöitä testattiin myös vertaamalla niiden antamia tuloksia kolmen erityyppisen käytävän äänenpainetasomittauksiin. Tässä tutkimuksessa on osoitettu, että akustisen kuvateorian pohjalta on mahdollista johtaa laskenta-algoritmi, jota voidaan soveltaa pitkien käytävien äänikenttien pika-arvioinnissa paikan päällä. Sekä teoreettinen laskenta että käytännön äänenpainetasomittaukset todellisilla käytävillä osoittivat, että JÄKÄLA-algoritmin yhtälöiden ennustustarkkuus oli erinomainen ideaalikäytävillä ja hyvä niillä todellisilla käytävillä, joilla ei ollut ääntä heijastavia rakenteita. NUMO- ja APPRO-yhtälöt näyttäisivät toimivan hyvin käytävillä, joiden poikkileikkaus oli lähes neliön muotoinen ja joissa pintojen suurin absorptiokerroin oli korkeintaan kymmenen kertaa pienintä absorptiokerrointa suurempi. NUMO- ja APPRO-yhtälöiden suurin puute on, etteivät ne ota huomioon pintojen erilaisia absorptiokertoimia eivätkä esineistä heijastuvia ääniä. NUMO- ja APPRO- laskentayhtälöt poikkesivat mitatuista arvoista eniten käytävillä, joilla kahden vastakkaisen pinnan absorptiokerroin oli hyvin suuri ja toisen pintaparin hyvin pieni, ja käytävillä, joissa oli massiivisia, ääntä heijastavia pilareita ja palkkeja. JÄKÄLA-algoritmin NUMO- ja APPRO-yhtälöt antoivat tutkituilla käytävillä kuitenkin selvästi tarkempia arvoja kuin Kuttruffin likiarvoyhtälö ja tilastollisen huoneakustiikan perusyhtälö. JÄKÄLA-algoritmin laskentatarkkuutta on testattu vain neljällä todellisella käytävällä. Algoritmin kehittämiseksi tulisi jatkossa käytävän vastakkaisia pintoja ja niiden absorptiokertoimia käsitellä laskennassa pareittain. Algoritmin validiteetin varmistamiseksi on mittauksia tehtävä lisää käytävillä, joiden absorptiomateriaalien jakautumat poikkeavat toisistaan.

Research and development of III-V semiconductor surfaces for improved device interfaces

This thesis is devoted to understanding and improving technologically important III-V compound semiconductor (e.g. GaAs, InAs, and InSb) surfaces and interfaces for devices. The surfaces and interfaces of crystalline III-V materials have a crucial role in the operation of field-effect-transistors (FET) and highefficiency solar-cells, for instance. However, the surfaces are also the most defective part of the semiconductor material and it is essential to decrease the amount of harmful surface or interface defects for the next-generation III-V semiconductor device applications. Any improvement in the crystal ordering at the semiconductor surface reduces the amount of defects and increases the material homogeneity. This is becoming more and more important when the semiconductor device structures decrease to atomic-scale dimensions. Toward that target, the effects of different adsorbates (i.e., Sn, In, and O) on the III-V surface structures and properties have been investigated in this work. Furthermore, novel thin-films have been synthesized, which show beneficial properties regarding the passivation of the reactive III-V surfaces. The work comprises ultra-high-vacuum (UHV) environment for the controlled fabrication of atomically ordered III-V(100) surfaces. The surface sensitive experimental methods [low energy electron diffraction (LEED), scanning tunneling microscopy/spectroscopy (STM/STS), and synchrotron radiation photoelectron spectroscopy (SRPES)] and computational density-functionaltheory (DFT) calculations are utilized for elucidating the atomic and electronic properties of the crucial III-V surfaces. The basic research results are also transferred to actual device tests by fabricating metal-oxide-semiconductor capacitors and utilizing the interface sensitive measurement techniques [capacitance voltage (CV) profiling, and photoluminescence (PL) spectroscopy] for the characterization. This part of the thesis includes the instrumentation of home-made UHV-compatible atomic-layer-deposition (ALD) reactor for growing good quality insulator layers. The results of this thesis elucidate the atomic structures of technologically promising Sn- and In-stabilized III-V compound semiconductor surfaces. It is shown that the Sn adsorbate induces an atomic structure with (1×2)/(1×4) surface symmetry which is characterized by Sn-group III dimers. Furthermore, the stability of peculiar ζa structure is demonstrated for the GaAs(100)-In surface. The beneficial effects of these surface structures regarding the crucial III-V oxide interface are demonstrated. Namely, it is found that it is possible to passivate the III-V surface by a careful atomic-scale engineering of the III-V surface prior to the gate-dielectric deposition. The thin (1×2)/(1×4)-Sn layer is found to catalyze the removal of harmful amorphous III-V oxides. Also, novel crystalline III-V-oxide structures are synthesized and it is shown that these structures improve the device characteristics. The finding of crystalline oxide structures is exploited by solving the atomic structure of InSb(100)(1×2) and elucidating the electronic structure of oxidized InSb(100) for the first time.

Ring Dark Solitons in Toroidal Bose-Einstein Condensates

In this Thesis, we study various aspects of ring dark solitons (RDSs) in quasi-two-dimensional toroidally trapped Bose-Einstein condensates, focussing on atomic realisations thereof. Unlike the well-known planar dark solitons, exact analytic expressions for RDSs are not known. We address this problem by presenting exact localized soliton-like solutions to the radial Gross-Pitaevskii equation. To date, RDSs have not been experimentally observed in cold atomic gases, either. To this end, we propose two protocols for their creation in experiments. It is also currently well known that in dimensions higher than one, (ring) dark solitons are susceptible, in general, to an irreversible decay into vortex-antivortex pairs through the snake instability. We show that the snake instability is caused by an unbalanced quantum pressure across the soliton's notch, linking the instability to the Bogoliubov-de Gennes spectrum. In particular, if the angular symmetry is maintained (or the toroidal trapping is restrictive enough), we show that the RDS is stable (long-lived with a lifetime of order seconds) in two dimensions. Furthermore, when the decay does take place, we show that the snake instability can in fact be reversible, and predict a previously unknown revival phenomenon for the original (many-)RDS system: the soliton structure is recovered and all the point-phase singularities (i.e. vortices) disappear. Eventually, however, the decay leads to an example of quantum turbulence; a quantum example of the laminar-to-turbulent type of transition.

Segmentation of overlapping convex objects

This thesis presents a framework for segmentation of clustered overlapping convex objects. The proposed approach is based on a three-step framework in which the tasks of seed point extraction, contour evidence extraction, and contour estimation are addressed. The state-of-art techniques for each step were studied and evaluated using synthetic and real microscopic image data. According to obtained evaluation results, a method combining the best performers in each step was presented. In the proposed method, Fast Radial Symmetry transform, edge-to-marker association algorithm and ellipse fitting are employed for seed point extraction, contour evidence extraction and contour estimation respectively. Using synthetic and real image data, the proposed method was evaluated and compared with two competing methods and the results showed a promising improvement over the competing methods, with high segmentation and size distribution estimation accuracy.

Lecythidaceae Poit. in the Tupé Sustainable Development Reserve, Manaus, Brazil

Lecythidaceae is the family of the Brazil nut, and comprises about 300 species belonging to 17 genera with pantropical distributions. One hundred and twenty-two species belonging to nine genera are distributed throughout Brazil, demonstrating its greatest diversity in the Amazon rainforest where Lecythidaceae is also one of the most abundant families. It is usually difficult to collect fertile material from these trees because of their canopy heights, and species determinations using sterile material can be complex because of their morphological similarities. There have been relatively few studies of this family even though it is one of the most important groups in the Amazon region, and a detailed taxonomic treatment of the species of Lecythidaceae in the Tupé Sustainable Development Reserve was therefore the goal of the present work. Ten species were found, Allantoma lineata (Mart. ex O.Berg) Miers, Bertholletia excelsa Bonpl., Couratari tenuicarpa A.C.Sm., Lecythis poiteaui O. Berg; and six species of Eschweilera, the richest genus. The descriptions and identification keys of the species used 56 characters. The main reproductive characters useful for distinguishing the species were the pubescence of the inflorescence rachis, pedicel length and trichomes presence, floral symmetry, hood type, filament shape, stigma shape, fruit shape and size, and aril type. The most diagnostic vegetative characters were the type and color of the outer bark, inner bark color, midrib prominence, and petiole shape and pubescence.

Occurrence of Akodon cursor (Rodentia, Cricetidae) with 14, 15 and 16 chromosome cytotypes in the same geographic area in Southern Brazil

The karyotype of Akodon cursor (initially identified as A. arviculoides) had been reported with chromosomal numbers 14 and 15 in the South and Southeast and 16 in Northeastern Brazil. We found the three cytotypes in a region of Southern Brazil. The G-band patterns of these specimens were the same as those from southeastern and northeastern regions. Seventeen different combinations of chromosomes due to a complex rearrangement in pair 1 and pericentric inversions in pairs 2 and 3 were identified. Seven of these combinations are new to in the literature.

Trisomy 13 mosaicism demonstrated only in skin fibroblasts in a patient presenting psychomotor retardation, pigmentary dysplasia and some dysmorphic features

A Brazilian female infant presented delayed psychomotor development, skin pigmentary dysplasia and some dysmorphic features. Chromosome analysis from peripheral blood culture was normal, but the karyotype from skin fibroblasts revealed mosaicism for trisomy 13. This case demonstrates the relevance of performing chromosomal analysis of skin fibroblasts in patients with mental retardation, associated with pigmentary dysplasia of the skin and a normal karyotype in peripheral blood lymphocytes. To our knowledge, it is the first report of trisomy 13 demonstrated only in skin fibroblasts.

First description of microchromosome in the Anostomidae fish Schizodon nasutus from Argentina

Thirty-six specimens of Schizodon nasutus (Anostomidae-Characiformes) from the middle Paraná River (Posadas, Argentina) were analyzed cytogenetically. The karyotype of this species was similar to those described for this species in the literature. C-banding technique showed a rich heterochromatic pattern relative to other Anostomidae species. The NORs were located on one chromosome pair in terminal position and showed a very marked size heteromorphism. A microchromosome was observed with a frequency of about 20% in the sample studied. This additional element was punctiform, negative C-band, and constant in all metaphase plates of the seven carriers. The present study is the first karyotypic approach to Schizodon nasutus from Argentina and the first description of microchromosome in Anostomidae

Chromosome number and secondary constriction variation in 51 accessions of a citrus germplasm bank

The mitotic chromosomes of 51 citrus accessions from the Centro Nacional de Pesquisa em Mandioca e Fruticultura Tropical, Cruz das Almas, BA, Brazil, were analyzed. The sample included representatives of 20 Citrus species, one of Poncirus and seven hybrids. All accessions showed 2n = 18 without any evidence of numerical variation. The most clearly variable karyotype feature was the number and position of secondary constrictions (SECs). In 19 accessions the SECs were not identified, mainly due to the degree of chromatin condensation. In the remainder they varied in number from one to three per karyotype. They were found in the proximal region of one of the three largest chromosome pairs, in the terminal/subterminal region of a smaller chromosome or, more seldom, terminally in a larger chromosome. Only in a few cases were such constrictions observed simultaneously in both homologues of the same chromosome pair. The high variability of this karyotype feature may be due to the activation of this region in the previous interphase but may also indicate a high structural variability and heterozygosity of citrus germplasms

Deletion/inversion in the X-chromosome and increased telomeric associations in a female with primary amenorrhea

We describe a new case of a partial interstitial deletion and inversion of the long arm of the X-chromosome associated with a high incidence of telomeric associations in an 18-year old female who showed underdeveloped secondary sex characteristics, including small breasts and primary amenorrhea. Her karyotype was considered to be 46,X,del(Xq13 -> q22)inv(X)(q23-q27). The buccal mucosal cells showed absence of a typical Barr body, and the 5’-bromo-2-deoxyuridine incorporation studies revealed that neither the normal X-nor the abnormal X-chromosome was late replicating. The case is being presented for its extreme rarity

Evaluation of techniques for C and ASG banding of the mitotic chromosomes of Anastrepha species (Diptera, Tephritidae)

Methods previously described by Canovai et al. (Caryologia 47: 241-247, 1994) which produced C and ASG bands in mitotic chromosomes of Ceratitis capitata were applied to the chromosomes of several Anastrepha species. Metaphase plate yield was substantially increased by use of imaginal disks together with cerebral ganglia. The C-bands were quite prominent allowing the resolution of tiny blocks of heterochromatin. The ASG method produced G-like banded chromosomes, which permitted recognition of each individual chromosome. These simple techniques do not require special equipment and may be valuable for karyotype variability studies in fruit flies and other Diptera

Acute promyelocytic leukemia: the study of t(15;17) translocation by fluorescent in situ hybridization, reverse transcriptase-polymerase chain reaction and cytogenetic techniques

Acute promyelocytic leukemia (AML M3) is a well-defined subtype of leukemia with specific and peculiar characteristics. Immediate identification of t(15;17) or the PML/RARA gene rearrangement is fundamental for treatment. The objective of the present study was to compare fluorescent in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR) and karyotyping in 18 samples (12 at diagnosis and 6 after treatment) from 13 AML M3 patients. Bone marrow samples were submitted to karyotype G-banding, FISH and RT-PCR. At diagnosis, cytogenetics was successful in 10 of 12 samples, 8 with t(15;17) and 2 without. FISH was positive in 11/12 cases (one had no cells for analysis) and positivity varied from 25 to 93% (mean: 56%). RT-PCR was done in 6/12 cases and all were positive. Four of 8 patients with t(15;17) presented positive RT-PCR as well as 2 without metaphases. The lack of RT-PCR results in the other samples was due to poor quality RNA. When the three tests were compared at diagnosis, karyotyping presented the translocation in 80% of the tested samples while FISH and RT-PCR showed the PML/RARA rearrangement in 100% of them. Of 6 samples evaluated after treatment, 3 showed a normal karyotype, 1 persistence of an abnormal clone and 2 no metaphases. FISH was negative in 4 samples studied and 2 had no material for analysis. RT-PCR was positive in 4 (2 of which showed negative FISH, indicating residual disease) and negative in 2. When the three tests were compared after treatment, they showed concordance in 2 of 6 samples or, when there were not enough cells for all tests, concordance between karyotype and RT-PCR in one. At remission, RT-PCR was the most sensitive test in detecting residual disease, as expected (positive in 4/6 samples). An incidence of about 40% of 5' breaks and 60% of 3' breaks, i.e., bcr3 and bcr1/bcr2, respectively, was observed.