cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.15156/bio/sh1291683.08fu
title: SH1291683.08FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.14457/cu.the.2006.1545
title: Robust constrained model predictive control with a parameter-dependent lyapunov function using linear matrix inequalities

description: This thesis presents robust constrained model predictive control for linear time-varying systems under parametric uncertainties. In order to guarantee robust performance, the control law applies a parameter-dependent Lyapunov function which corresponds to vertices of the polytopic uncertainty. The design approach is divided into two parts. The first part is focused on the design of a robust state feedback law that minimizes, at each sampling time, an upper bound of the worst-case objective function, subject to constraints on control inputs and process outputs. The state feedback design problem is cast as convex optimization involving linear matrix inequalities (LMIs) which can be efficiently solved. The second part emphasizes on a robust output feedback scheme that utilizes the state feedback obtained from the first part together with state estimator. The synthesis approach is to solve off-line LMI problems to guarantee the robust stability of the augmented closed-loop system. In comparison with the previous work whose design employs a single Lyapunov function, the method proposed in this thesis yields less conservative performance and further improves the algorithm. In particular, the design method is capable of handling a wider range of uncertain time-varying parameters. Finally, several applications are presented to illustrate the effectiveness of the control technique.
DOI: 10.14457/cu.the.2006.1546
title: Effect of boron-modified MCM-41 on cobalt/MCM-41 catalyst for carbon monoxide hydrogenation

description: In the present study, differences in characteristics and catalytic activity towards CO hydrogenation of Co catalysts dipersed on various boron-modified MCM-41 supports were investigated. The various weight ratios of MCM-41/B were prepared by incipient wetness impregnation method, then calcined them in air. Then, consequently impregnated with the cobalt precursor. After calcinations, the various samples were characterized using N[subscript 2] physisorption, XRD, SEM/EDX, TEM, TPR and H[subscript 2] chemisorption CO hydrogenation (H[subscript 2]/CO = 10/1) was also performed to determine the overall activity and selectivity. It revealed that the size of Co oxide species depends on the boron content on modification support. A wide range of variables including particle size, support interaction, and the boron content can affect the kinetics of reduction. It was found that for the boron modified MCM-41 catalyst, the catalyst dispersed on the high boron content support exhibited low activities due to low reduciblilty. With small amount of cobalt loading, activity decreased due to a decrease in reducibility. Selectivity to C[subscript 2]-C[subscript 4] products slightly increased with increasing boron loading.
DOI: 10.14457/cu.the.2006.1547
title: Analysis of automotive paints by ATR FT-IR microspectroscopy

description: ATR FT-IR microspectroscopy is used to analyze and identify the automotive paints. Three types of automotive paints including paint chips of different colors and shades, multilayer automotive paints, and thin trace smear on automotive paint were characterized by ATR FT-IR microspectroscopy. Two homemade [micro]ATR accessories; the slide-on diamond [micro]IRE and the slide-on Ge [micro]IRE, using an infrared microscope were employed for surface characterization of automotive paints. The spectra acquired by the slide-on diamond [micro]IRE and the slide-on Ge [micro]IRE were similar to those acquired by conventional ATR technique. The spectra from different colors and shades of paint show different spectral features due to the difference in compositions such as binder, pigment, and additive. Due to small contact area of the slide-on diamond [micro]IRE and slide-on Ge [micro]IRE, an individual layer of the multilayered automotive paints can be selectively analyzed without layer separation changing in chemical composition in each small sampling position can be analyzed. In additional, paints with the same colors but different chemical composition can be identified by surface line mapping. Thin trace smear were analyzed directly without interference from paint support by the slide-on Ge [micro]IRE. The slide-on diamond [micro]IRE and the slide-on Ge [micro]IRE were suitable for forensic analysis of automotive paint because of their small contact area and good contact with the sample. The technique is non-destructive, has short analysis time, can be performed without a sample preparation.
DOI: 10.14457/cu.the.2006.1548
title: Analysis and design of a 3-stage CMOS current controlled ring oscillator

description: This thesis describes a ring oscillator using 3 stages of an NMOS driving a current load and a capacitor. Its frequency can be shown to increase monotonically with the load current giving rise to the name current controlled oscillator (CCO). The CCO circuit using 180 [micrometre]/0.18 [micrometre] NMOS with 1pF load can be tuned to oscillate from 468 Hz to 305 MHz using load current from 1nA to 1mA. An accurate derivation of the formulae relating the frequency with current has been derived. Its calculation result agrees with the simulation result to a high accuracy within 1 %. Then the effect of the channel length modulation has been attempted to derive using the same method, but it is too complicated to be solved. Original and improved CCO are designed. They have output frequency of 10.02 MHZ and 10MHz respectively. The improved circuit employs additional buffers to make it is considerably more linear than the conventional one.
DOI: 10.14457/cu.the.2006.1549
title: Synthesis of pyrenylcalix[4]arene-calix[4]pyrrole as fluorogenic sensor for anion

description: A fluorogenic sensor for anion, pyrenylcalix[4]arene-calix[4]pyrrole (7), was successfully synthesized and characterized by spectroscopic techniques. It was revealed that the conformations of calix[4]arene and calix[4]pyrrole of 7 are in cone and 1,3-alternate manners, respectively. The glycolic spacers are in trans-position. Anion complexation studies of ligand 7 were carried with tetrabutylammonium salts by fluorescence spectroscopy. The spectra of all complexes exhibited an increase of monomer fluorescence emission at wavelengths of 376 and 396 nm when excited at 343 nm by a PET-based mechanism. According to fluorescence titrations, fluorogenic sensor 7 formed complexes with high affinity to fluoride following by acetate, chloride, bromide, benzoate, ions with logK of 3.45, 3.25, 1.74, 1.62 and 1.28 respectively. An addition of excesses fluoride ion to a solution of 7 resulted in a color change of solution of 7 and fluorescence quenching at visible region.
DOI: 10.14457/cu.the.2006.1550
title: Changes of lower-leg blood flow and skin temperature in response to cold application in middle aged to elderly men

description: Ice, compression, and elevation are the basic principles of acute soft tissue injuries management. Few clinicians, however, can give specific evidence based guidance on the appropriate recommendation especially for the elderly because no literatures regarding local vascular response and skin temperature during cold application have been reported. The objective of this study was to examine leg arterial blood flow and skin temperature in response to cold application in middle aged to elderly men (OLD group) compared to young men (YOUNG group. Two hundred and fifty healthy men participated as subjects ranging in age for the YOUNG group from 18-35 years (24.7 +- 4.4 years) and 42-85 years (61.6 +- 8.5 years) for the OLD group. An ice pack was wrapped in a wet towel before applied to the left ankle overlying the medial malleolus for 20 minutes. Leg arterial blood flow using venous occlusion strain gauge plethysmography and skin temperature using tele-thermometer were recorded in every minute of cold application. The result showed that the skin temperatures were continuously decreased during cold application in both groups. There was a significant difference in skin temperature between YOUNG group (15.2 +- 2.7 ํC) and OLD group (16.4 +- 2.6 ํC) at the end of cold application (p&lt; 0.001). The YOUNG group demonstrated a greater drop in skin temperature than the OLD group group (17.5 +- 2.3ํC vs 15.7 +- 2.3 ํC). However, a significant difference in blood flow reduction from baseline was not observed between YOUNG and OLD group. In conclusion, the reduction in skin temperature did not coincide with the decrement in leg blood flow for both young and middle aged to elderly men when cryotherapy was applied for a period of up to 20 minutes.
DOI: 10.14457/cu.the.2006.1551
title: Extending language models with term proximity weight to utilize term set relation in information retrieval

description: This research work is aimed at improving the performance of ad hoc information retrieval via a novel method to compute query term weights on the assumption that terms can be grouped by concepts, as against the conventional practice that terms are independent of one another. The new method is based on the approach that the importance of a term is determined by its contribution to the key concept term of the text. The research introduces a heuristics to group terms by concepts. To visualize it, a graph is plotted with the ordered term positions of a query on the x-axis and the well-known idf weights (Inverse Document Frequency) on the y-axis. Peak terms are classified as concept terms if their idf weights are above a threshold. The highest peak term is the key concept term. Each peak terms are supported by satellite terms on both sides. Between two adjacent peak terms, the term with the lowest idf weight is used to mark a boundary of term sets. Computation is a tree-stepped process: the first to compute the importance of the concept term to the distinct key concept term, the second to estimate the importance of a term in reference to the concept term of the same term set, and the last to compute the importance of the term to the key concept. The calculated weights differ from the idf weight in that the former reflects term importance in the context of a reference concept, i.e. it is a local property, whereas the idf weight is a global property derived from a document collection. In this way, the proposed method can be seen as a context-dependent or concept-determined importance. To test the efficiency of the new term weighting scheme, an experimental design is devised on the hypothesis that a query with concept-dependent weights for its terms would yield better ad hoc information retrieval results. Experiments are conducted within the language modeling framework using query likelihood scoring method and Dirichlet prior smoothing technique. They produce convincing gains for the new approach compared to the baseline and the idf-based results. Improvements are significantly positive on all accounts and are particularly outstanding in the precision area. Using TREC 7 and TREC 8 query sets, the experiments report a 16.12% and 15.74% increases in mean average precision (MAP) respectively. The new method also outperforms the idf-based scheme by 9.10%, and 13.34% for TREC 7 and TREC 8 query sets respectively.
DOI: 10.14457/cu.the.2006.1552
title: Cellular effects of barakol-induced apoptosis in P19 cells

description: Barakol is an active constituent extracted from Cassia siamea Lam., which has been used in folk medicine for the treatment of insomnia, however, its toxicity was reported and became an important limitation of using this herbal drug. Since, the mechanism by which barakol-induced toxicity has not been elucidated, this study thus investigated the cytotoxicity of barakol and its underlying mechanism in P19 embryonic stem cells. The extraction of barakol was obtained with a 0.1% yield. The barakol stability in culture medium was clarified and its stability was still stable until 24 h. Treament with barakol decreased cell viability in a time-dependent and a concentration-dependent manner measured by XTT assay with the IC[subscript 50] value of 1.5 mM. Thus the type of cell death was evaluated. Hoechst 33342 assay showed a significant increase in apoptosis after 24 h incubation of barakol. While the pretreatment with antioxidants such as N-acetyl-L-cysteine (NAC) or glutathione (GSH) showed the significant decrease in apoptotic cells, suggesting that reactive oxygen species (ROS) may play a role in barakol-mediated apoptosis. Whereas the flow cytometric analysis using propidium iodide staining showed that the distribution G[subscript 0]/ G[subscript 1] cell cycle phase was different from control. The molecular mechanism of barakol-induced apoptosis via the generation of ROS was further elucidated. Treatment with barakol showed a significant increase in the ROS level, peaking at 2h , detected by flow cytometry using 2' , 7' -dichlorodihydrofluorescein diacetate (DCFH-DA). Pretreatment of cells with NAC or GSH significantly inhibited ROS generation as well as apoptosis induced by barakol. To characterize ROS, The scavenging effects unsing manganese (III)tetrakis (4-benzoic acid) porphyrin chloride (MnTBAP, a superoxide dismutase mimetic), catalase (a hydrogen peroxide scavenger), and sodium formate (a hydroxyl radical scavenger) were performed. Pretreatment with MnTBAP or catalase had no significant change in ROS signal comparing to the barakol treated control, indicating the absence of the involvement of superoxide anion or hydrogen peroxide in this system. Pretreatment with sodium formate completely abolished the effect of barakol-induced ROS generation. The result indicated that the predominant ROS in barakol-induced apoptosis was hydroxyl radical. Furthermore, the activity of caspase-9 significantly increased after treatment of the cells with barakol. Taken together, induction of apoptosis in P19 cells by barakol was mainly associated with the ROS generation, mitochondrial dysfunction, and caspase-9 activation.
DOI: 10.14457/cu.the.2006.1553
title: Antimicrobial agents from endophytic fungi Aspergillus terreus isolated from Zingiber cassumunar Roxb. rhizomes

description: The purpose of this research was to isolate antimicrobial compounds from endophytic fungi isolated from Zingiber cassumunar rhizomes obtained from Surin, Supanburee, Songkhla and Pathumthanee province. The endophytic fungi were isolated using surface-sterilization technique to give 48 isolates including 59% Mycelia sterilia, 35% Fusarium sp., 4% Aspergillus sp. And 2% Schlerotium sp. All isolates were examined antimicrobial activity using agar plate bioassay. The results showed that 10 isolates of the fungi inhibited tested microorganisms. Isolate ZcSR5-4 was selected for the study because it exhibited activity against Bacillus subtilis and Escherichia coli with inhibition clear zone 1.50 and 2.50 cm, respectively while others showed less activity. Based on morphology and nucleotide sequencing of Internal Transcribed Spacer (ITS) regions of rDNA, isolate ZcSR5-4 was identified as Aspergillus terreus. Mycelium and broth of isolate ZcSR5-4 were isolated by extraction and chromatographic technique to give 3 known compounds. On the basis of physical properties and spectroscopic data, they were elucidated as butyrolactone I, butyrolactone III and butyrolactone IV. These compounds were examined Inhibitory Concentrations (MICs). Butyolactone I inhibited B. subtilis ATCC6633, S. aureus ATCC25923, E. coli ATCC25922 with the MICs values of 62.5 [microgram]/ml. (147.41 [micrometre]) and C. albicans ATCC10231 with the MICs values of 15.63 [microgram]/ml (36.86 [micrometre]; butyrolactone III inhibited all tested microorganisms and butyrolactone IV inhibited B. subtilis ATCC6633, S. aureus ATCC25923, E. coli ATCC25922 and P. aeruginosa ATCC27853 with the MICs values of 7.82 (17.77 [micrometre]), 31.25 (71.02 [micrometre]), 62.50 (142.04 micrometre) and 62.50 [microgram]/ml (142.04 micrometre]), respectively. In addition, all compounds were inactivity on cytotoxicity against 5 tumor cell lines.
DOI: 10.14457/cu.the.2006.1554
title: Effects of Malvastrum coromandelianum linn. extract on incision wound healing in diabetic and non-diabetic rats

description: The purpose of this study was to investigate the effect of an aqueous extract of Malvastrum coromandelianum on incision wound healing in diabetic and non-diabetic rats. Experiments were carried out in male Spraque-Dawley rats weighing 250-300 g. Rats were divided into 2 groups of 60 animals each for diabetic and non-diabetic rats models. Diabetes was induced by injection of Streptozotocin in the dose of 50 mg/kg B.W. intraveneously into tail vein. The animal in both groups were randomly subdivided into five sub groups as follow: untreated, NSS-treated, 1%, 5% and 10% of Malvastrum coromandelianum treated-group. Tested substances were applied topically once a day. On day 3 and 7 post wounding, the tensile strength, total collagen content, epidermal thickness and histopathological evaluation were assessed. In addition antibacterial activity of Malvastrum coromandelianum (1%, 5% and 10%) was tested using filter paper disk-agar diffusion. It was found that tensile strength and epidermal thickness of incision wound in diabetic group (day 7) and non-diabetic group (day 3) treated with 1% Malvastrum coromandelianum extract was significantly increased in comparison to those of untreated and NSS-treated groups while no significant increase of total collagen content was observed. In histopathological evaluation, the wound treated with Malvastrum coromandelianum extract tended to heal faster than those found in untreated and NSS-treated groups. Granulation as well as re-epithelialization were detected in herbal-treated groups earlier than those of untreated and NSS-treated groups. In addition none of 1%, 5% and 10% of Malvastrum coromandelianum extract was found to exhibit antibacterial activity against Staphylococcus aureus, Streptococcus pyogens, Pseudomonas aeruginosa and Escherichia coli. The present studies have demonstrated the wound healing effect of the aqueous extract of Malvastrum coromandelianum on incision wound in diabetic as well as non-diabetic rats though a slower rate of healing was noted in the diabetic group. An increase in epidermal thickness and positive effects on some other components than collagen of extracellular matrix exerted by 1% Malvastrum coromandelianum but not antibacterial activity seem to underlie an increase in tensile strength observed. Investigations to identify other possible mechanisms as well as active constituents of Malvastrum coromondelianum responsible for the wound healing effects should be further conducted.
DOI: 10.14457/cu.the.2006.1555
title: Expression and characterization of N-terminal truncation of Plasmodium falciparum orotate phosphoribosyl transferrase enzyme

description: Piasmodium falciparum, the causative agent of the most lethal form of human malaria, totally depends on de novo pyrimidine biosynthetic pathway. A gene encoding orotate phosphoribosyltransferase (OPRT), the fifth enzyme of the de novo pathway catalyzing formation of orotidine 5'-monophosphate (OMP) and pyrophosphate (PP[subscript i]) from 5-phosphoribosyl-1-pyrophosphate (PRPP) and orotate, was identified from P. falciparum (pfOPRT), and was exceptional in that it contained an amino-terminal extension of 66 amino acids, making the longest amino acid sequence (218 amino acids). This unique sequence remains uncharacterized the importance in the parasite. In this study, the cDNA of the full-length and N-terminal truncated pfOPRT gene was cloned and expressed. The both types of the recombinant pfOPRT were purified from the E. coli lysate by nickel metal-affinity chromatography. After that The both types of the recombinant pfOPRT were analyzed by SDS-PAGE and Western blot. Furthermore, the studying in activity and stability were included. The results revealed that the full-length and N-terminal truncated pfOPRT had a molecular mass of 35 kDa and 30 kDa, respectively. The specific activity of the N-terminal truncated pfOPRT was decreased about 10-fold when compared with the full-length pfOPRT. The stability of the N-terminal truncated pfOPRT was lower than the full-length pfOPRT. So, it concluded that the N-terminal truncated pfOPRT, which had a molecular weight of 30 kDa, had less specific activity and stability than the full-length pfOPRT. These evidences provided that the N-terminal extension of pfOPRT may have an important role in the activity and stability of this enzyme, therefore it may be the new target for structure-based antimalarial drug design. To block this extension part will take the action on parasite survival by limiting the pyrimidine base biosynthesis.
DOI: 10.14457/cu.the.2006.1556
title: An enhancement of reeb graph for modeling hydrogeological information

description: Three-dimensional visualization has been useful for several geological information systems. Typical visualization methods in computer graphics usually cannot properly represent the multi-layer geographical data because of the lack of relation between each soil layer. In addition, some errors in the estimated position of soil layers and in the classification of soil layers can occur. This research, therefore, presents an enhancement of Reeb graph method for three-dimensional geological information providing the complex internal structure of soil layers. Proposed method can calculate major geological information, such as the positions of soil layers, the cross-sectional contours of soil layers at each height level corresponding to the input data. Firstly, the original Reeb graph is enhanced by changing from the relation between Reeb node and its contour to the relation between each Reeb node and its set of contours. Then, the surface is constructed from the set of contours. After specifying the position of each soil layer and constructing each surface for each soil layer according to the input depth, the cross-sectional contours of each soil layer at every critical height are then calculated using Morse theory. Next the enhanced Reeb graph is generated. Finally, the reconstructed surfaces represent the complete internal structure of the geological information. The experimental result shows that the proposed method can be efficiently applied for storing and displaying the cross-sectional data and the structure of soil layers of the hydrogeological information.