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Добірка наукової літератури з теми "High and Ultra High Molecular Weight DNA"

Автор: Grafiati

Опубліковано: 11 березня 2023

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Статті в журналах з теми "High and Ultra High Molecular Weight DNA"

1

‘Giron’ Koetsier, Paul A., and Eric J. Cantor. "A simple approach for effective shearing and reliable concentration measurement of ultra-high-molecular-weight DNA." BioTechniques 71, no. 2 (August 2021): 439–44. http://dx.doi.org/10.2144/btn-2021-0051.

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Pipetting and concentration measurement of viscous ultra-high-molecular-weight (UHMW) DNA samples is challenging and often highly imprecise. Effective guidelines for handling UHMW samples are missing in the field. Herein, a simple and low-cost workflow is presented that enables accurate pipetting and reliable concentration measurement. Central to the workflow is the shearing of representative small aliquots of UHMW DNA samples to a fragment size <150 kb by vortexing them for 1 min with a glass bead in a round-bottomed 2-ml tube. Additionally, a solution is provided for accurate quantitation of high-molecular-weight DNA with fluorometric (Qubit [Thermo Fisher Scientific, MA, USA]) methods by using an appropriate genomic DNA standard, resulting in values that match spectrophotometric (Nanodrop [Thermo Fisher Scientific]) optical density readings.

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2

Ho, S. P., L. Riester, M. Drews, T. Boland, and M. LaBerge. "Nanoindentation properties of compression-moulded ultra-high molecular weight polyethylene." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 217, no. 5 (May 1, 2003): 357–66. http://dx.doi.org/10.1243/095441103770802522.

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This paper investigates the elastic modulus and hardness of untreated and treated compression-moulded ultra-high molecular weight polyethylene (UHMWPE) tibial inserts of a total knee replacement (TKR) prosthesis. Investigations were carried out at a nanoscale using a Nanoindenter™ at penetration depths of 100, 250 and 500 nm. The nanomechanical properties of surface and subsurface layers of the compression-moulded tibial inserts were studied using the untreated UHMWPE. The nanomechanical properties of intermediate and core layers of the compression-moulded tibial insert were studied using the cryoultrasectioned and etched UHMWPE treated samples. The cryoultrasectioning temperature (-150°C) of the samples was below the glass transition temperature, Tg(-122± 2°C), of UHMWPE. The measurement of the mechanical response of crystalline regions within the nanostructure of UHMWPE was accomplished by removing the amorphous regions using a time-varying permanganic-etching technique. The percentage crystallinity of UHMWPE was measured using differential scanning calorimetry (DSC) and the Tg of UHMWPE was determined by dynamic mechanical analysis (DMA). Atomic force microscopy (AFM) was used to assess the effect of surface preparation on the samples average surface roughness, Ra. In this study, it was demonstrated that the untreated UHMWPE samples had a significantly lower ( p<0.0001) elastic modulus and hardness relative to treated UHMWPE cryoultrasectioned and etched samples at all penetration depths. No significant difference ( p > 0.05) in elastic modulus and hardness between the cryoultrasectioned and etched samples was observed. These results suggest that the surface nanomechanical response of an UHMWPE insert in a total joint replacement (TJR) prosthesis is significantly lower compared with the bulk of the material. Additionally, it was concluded that the nanomechanical response of material with higher percentage crystallinity (67 per cent) was predominantly determined by the crystalline regions within the semi-crystalline UHMWPE nanostructure.

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3

Rahmah, Alyda Aliyah, Silvana Tana, and Siti Muflichatun Mardiati. "Analisis Hematologi Kelinci setelah Implantasi Ultra High Molecular Weight Poliethylene (UHMWPE) pada Sendi Lutut." Buletin Anatomi dan Fisiologi 2, no. 2 (November 8, 2017): 99. http://dx.doi.org/10.14710/baf.2.2.2017.99-106.

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Penelitian ini bertujuan untuk menganalisis respon fisiologi tubuh kelinci terhadap implantasi Ultra High Molecular Weight Poliethylene (UHMWPE) dilihat dari aspek jumlah eritrosit, jumlah leukosit dan kadar hemoglobin sebagai salah satu data pendukung untuk dasar penelitian lebih lanjut dalam rangka pembuatan sendi buatan yang sesuai dengan anatomi tubuh orang Indonesia. Penelitian ini menggunakan Rancangan Acak Kelompok menggunakan 6 ekor kelinci jenis Lop umur 2,5 bulan yang dibagi dalam dua (2) perlakuan yaitu membandingkan kelinci yang tidak diberikan implantasi UHMWPE (kontrol) (P0) dengan kelinci yang diberikan perlakuan implantasi UHMWPE (P1). Parameter utama adalah jumlah eritrosit, jumlah leukosit dan kadar hemoglobin, serta parameter pendukung adalah konsumsi pakan dan bobot tubuh kemudian dianalisis dengan Uji T Sampel Independen dengan bantuan perangkat lunak SPSS pada taraf kepercayaan 95%. Hasil penelitian menunjukkan bahwa jumlah eritrosit, jumlah leukosit dan kadar hemoglobin berbeda tidak nyata (p>0,05) antara kontrol dengan perlakuan. Penggunaan implantasi UHMWPE selama 2,5 bulan tidak menyebabkan perubahan pada jumlah eritrosit, jumlah leukosit dan kadar hemoglobin dalam tubuh hewan model. Hal ini dapat disimpulkan bahwa material UHMWPE merupakan material implan yang dapat digunakan pada tubuh manusia. Kata Kunci : Ultra High Molecular Weight Poliethylene (UHMWPE), Kelinci, hematologi

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4

Jaudou, Sandra, Mai-Lan Tran, Fabien Vorimore, Patrick Fach, and Sabine Delannoy. "Evaluation of high molecular weight DNA extraction methods for long-read sequencing of Shiga toxin-producing Escherichia coli." PLOS ONE 17, no. 7 (July 13, 2022): e0270751. http://dx.doi.org/10.1371/journal.pone.0270751.

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Next generation sequencing has become essential for pathogen characterization and typing. The most popular second generation sequencing technique produces data of high quality with very low error rates and high depths. One major drawback of this technique is the short reads. Indeed, short-read sequencing data of Shiga toxin-producing Escherichia coli (STEC) are difficult to assemble because of the presence of numerous mobile genetic elements (MGEs), which contain repeated elements. The resulting draft assemblies are often highly fragmented, which results in a loss of information, especially concerning MGEs or large structural variations. The use of long-read sequencing can circumvent these problems and produce complete or nearly complete genomes. The ONT MinION, for its small size and minimal investment requirements, is particularly popular. The ultra-long reads generated with the MinION can easily span prophages and repeat regions. In order to take full advantage of this technology it requires High Molecular Weight (HMW) DNA of high quality in high quantity. In this study, we have tested three different extraction methods: bead-based, solid-phase and salting-out, and evaluated their impact on STEC DNA yield, quality and integrity as well as performance in MinION long-read sequencing. Both the bead-based and salting-out methods allowed the recovery of large quantities of HMW STEC DNA suitable for MinION library preparation. The DNA extracted using the salting-out method consistently produced longer reads in the subsequent MinION runs, compared with the bead-based methods. While both methods performed similarly in subsequent STEC genome assembly, DNA extraction based on salting-out appeared to be the overall best method to produce high quantity of pure HMW STEC DNA for MinION sequencing.

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Demas, J. N., Ming Wu, Peter M. Goodwin, Rhett L. Affleck, and Richard A. Keller. "Fluorescence Detection in Hydrodynamically Focused Sample Streams: Reduction of Diffusional Defocusing by Association of Analyte with High-Molecular-Weight Species." Applied Spectroscopy 52, no. 5 (May 1998): 755–62. http://dx.doi.org/10.1366/0003702981944184.

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Fluorescence methods have been developed for ultra-low-level detection down to the single molecule level. In ultra-low-level analysis, one successful approach to background reduction is to use hydrodynamically focused sample streams coupled with focused laser excitation to reduce detection volumes. However, low-molecular-weight analytes such as fluorescent dyes or fluorescently tagged nucleotides can diffuse radially out of the sample stream before detection, which can cause a significant reduction in the detection efficiency. Diffusional spreading can cause sample stream mixing in multiplexed analyses. Also, axial diffusion can cause misordering of analyte molecules in DNA sequencing at high analysis rates. A new method is presented for reducing diffusion effects by incorporating a high-molecular-weight species that has a strong binding affinity for the analyte (anchor) into the sheath fluid. As the analyte starts to diffuse out of the sample stream, it associates with the anchor and effectively assumes the anchor's molecular weight. This association reduces the analyte's mobility to that of the anchor. Consequently, both radial and axial diffusion are reduced. Further, in favorable cases, this adduct can have significantly increased luminescence yields and photostability compared to the free analyte. Examples of several dye polymer combinations involving electrostatic and other binding modes are given that show the very beneficial effects of this approach. Extension to other systems is described.

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Wang, Fei, Jiabin Yu, Lichao Liu, Ping Xue, and Ke Chen. "Influence of high-density polyethylene content on the rheology, crystal structure, and mechanical properties of melt spun ultra-high-molecular weight polyethylene/high-density polyethylene blend fibers." Journal of Industrial Textiles 53 (January 2023): 152808372211501. http://dx.doi.org/10.1177/15280837221150198.

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High-density polyethylene (HDPE) content significantly influences the structure and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE)/HDPE blend fibers. The molecular chain disentanglement and crystallization characteristics of as-spun filaments and fibers and how the structure affects the final mechanical properties of the fibers were thoroughly studied by adding different contents of HDPE. Dynamic mechanical analysis (DMA) and rheological analysis indicated that the molecular entanglement decreased with increasing HDPE content, improving the UHMWPE melt processability. Sound velocity orientation (SVO) studies indicated that the UHMWPE/HDPE as-spun filaments and fibers with an HDPE content of 40 wt% (U6H4) had a higher molecular chain orientation level. Furthermore, differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) analyses indicated that U6H4 had the highest crystallinity and the thinnest grains in the axial direction, respectively. The compact crystal structure and fully stretched molecular chains of U6H4 yielded the best mechanical properties. The present work disclosed the effect mechanism of HDPE contents on the preparation and properties of UHMWPE/HDPE fibers, which provided an effective and universal strategy for manufacturing high-strength UHMWPE/HDPE fibers with the melt spinning method.

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7

Zarvianti, Enny, Dian Fitriyani, Elvaswer Elvaswer, Winda Surya Bery, Abu Khalid Rivai, Mardiyanto Mardiyanto, and Sulistioso G.S. "Karakterisasi Bahan Perisai Radiasi Neutron Ultra High Molecular Weight Polyethyene Dengan Filler Gd2O3 Menggunakan Teknik Radiografi Neutron." JURNAL ILMU FISIKA | UNIVERSITAS ANDALAS 9, no. 1 (March 23, 2017): 1–6. http://dx.doi.org/10.25077/jif.9.1.1-6.2017.

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Radiasi merupakan pancaran energi melalui suatu materi atau ruang dalam bentuk energi, panas, partikel atau gelombang yang dapat diserap oleh bahan lain. Beberapa radiasi dapat mengionisasi bahan yang dilaluinya salah satunya radiasi neutron karena memiliki daya tembus yang tinggi sehingga sangat diperlukan perisai radiasi. Adapun kriteria dari perisai radiasi neutron harus memiliki kandungan hidrogen yang tinggi, memiliki nilai tampang lintang yang baik dan tidak bersifat korosi. Bahan UHMWPE (Ultra High Molecular Weight Polyethyene) memiliki kandungan hidrogen yang tinggi dan tidak mudah korosi dan bahan Gadolinium oxide (Gd2O3) sangat baik menyerap neutron karena mempunyai tampang lintang serapan neutron yang tinggi. Berdasarkan hal tersebut maka dibuat komposit UHMWPE-Gd2O3 dengan tujuan dapat meningkatkan nilai serapan neutron sehingga dalam aplikasinya bisa lebih efektif untuk memperlambat bahkan menahan radiasi neutron. Telah dilakukan karakterisasi bahan perisai radiasi neutron yang dibuat sendiri dengan teknik radiografi neutron. Bahan perisai radiasi dibuat dengan bahan utama UHMWPE dan penambahan filler Gadolinium Oxide (Gd2O3) dengan kompoisisi 70% : 30% massa menggunakan metode blending dan kompaksi. Bahan dibuat dengan ketebalan yang bervariasi dari 0,5 cm hingga 2 cm. Hasil karakterisasi XRD menunjukkan tidak terbentuk senyawa kimia antara kedua bahan dan karakterisasi menggunakan SEM terlihat hasil distribusi unsur yang terkandung dalam filler Gd2O3 merata pada bahan dasar polimer. Pengujian serapan neutron menggunakan teknik radiografi neutron dengan metode film. Dengan penambahan variasi ketebalan meningkatkan daya serap bahan dari 58,78% menjadi 67,89% dan nilai koefisien atenuasi diperoleh sebesar 1,025.Kata kunci: perisai radiasi, UHMWPE,Gd2O3, radiografi neutron, daya serap dan koefisien atenuasi.

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Goldrich, David Y., Brandon LaBarge, Scott Chartrand, Lijun Zhang, Henry B. Sadowski, Yang Zhang, Khoa Pham, et al. "Identification of Somatic Structural Variants in Solid Tumors by Optical Genome Mapping." Journal of Personalized Medicine 11, no. 2 (February 18, 2021): 142. http://dx.doi.org/10.3390/jpm11020142.

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Genomic structural variants comprise a significant fraction of somatic mutations driving cancer onset and progression. However, such variants are not readily revealed by standard next-generation sequencing. Optical genome mapping (OGM) surpasses short-read sequencing in detecting large (>500 bp) and complex structural variants (SVs) but requires isolation of ultra-high-molecular-weight DNA from the tissue of interest. We have successfully applied a protocol involving a paramagnetic nanobind disc to a wide range of solid tumors. Using as little as 6.5 mg of input tumor tissue, we show successful extraction of high-molecular-weight genomic DNA that provides a high genomic map rate and effective coverage by optical mapping. We demonstrate the system’s utility in identifying somatic SVs affecting functional and cancer-related genes for each sample. Duplicate/triplicate analysis of select samples shows intra-sample reliability but also intra-sample heterogeneity. We also demonstrate that simply filtering SVs based on a GRCh38 human control database provides high positive and negative predictive values for true somatic variants. Our results indicate that the solid tissue DNA extraction protocol, OGM and SV analysis can be applied to a wide variety of solid tumors to capture SVs across the entire genome with functional importance in cancer prognosis and treatment.

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Dayyoub, Tarek, Aleksey Maksimkin, Leonid K. Olifirov, Dilus Chukov, Evgeniy Kolesnikov, Sergey D. Kaloshkin, and Dmitry V. Telyshev. "Structural, Mechanical, and Tribological Properties of Oriented Ultra-High Molecular Weight Polyethylene/Graphene Nanoplates/Polyaniline Films." Polymers 15, no. 3 (February 2, 2023): 758. http://dx.doi.org/10.3390/polym15030758.

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Preparing high-strength polymeric materials using an orientation drawing process is considered one of the most urgent topics in the modern world. Graphene nanoplates/polyaniline (GNP/PANI) were added to the commercial grade UHMWPE (GUR 4120) matrix as a filler with antifriction properties. The effect of GNP/PANI addition on the structure, the orientation process, the void formation (cavitation), the mechanical, and tribological properties was studied using differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), and scanning electron microscopy (SEM). The paper’s findings indicated an increase in the cavitation effect of 120–320% after the addition of GNP/PANI to the UHMWPE polymer matrix. This increase, during the process of the oriented films’ thermal orientation hardening, led, in turn, to a decrease in the tensile strength during the process of the oriented films’ thermal orientation hardening. Furthermore, the decrease in the coefficient of friction in the best samples of oriented UHMWPE films was two times greater, and the increase in wear resistance was more than an order of magnitude. This process was part of the orientation hardening process for the UHMWPE films containing PE-wax as an intermolecular lubricant, as well as the presence of GNP/PANI in the material, which have a high resistance to abrasive wear.

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Yang, Hui, Guillermo Garcia-Manero, Guillermo Montalban-Bravo, Kelly S. Chien, Awdesh Kalia, Zhenya Tang, Yue Wei, et al. "High-Throughput Characterization of Cytogenomic Heterogeneity of MDS Using High-Resolution Optical Genome Mapping." Blood 138, Supplement 1 (November 5, 2021): 105. http://dx.doi.org/10.1182/blood-2021-154005.

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Abstract Introduction Introduction of next-generation sequencing has defined the somatic mutational landscape in MDS. Comprehensive high-throughput structural variant profiling (SVP) is as important as mutation profiling in characterizing MDS clonal architecture since these large genomic aberrations have already shown to be critical for diagnosis and risk-stratification of MDS. A subset (MECOM, KMT2A rearrangements) are therapeutic targets in clinical trials. At this time, technical advances in SVP for copy number alterations (CNAs) and fusions have not been congruent with mutation profiling due to the inability of short-read (150bp) NGS to detect SVs. Currently available long-read (10-20Kbp) and whole genome sequencing cannot detect all SVs due to the presence of repeat sequences. Hence, conventional karyotyping (CK) remains the gold standard. Optical genome mapping (OGM) is a novel single-platform technique that measures ultra-long-range sequence patterns (>300Kbp), thereby unaffected by repeat sequences, enabling unbiased evaluation of all types of SVs at a high resolution. Here, we performed comprehensive SVP and mutation profiling in a large well-characterized cohort of MDS. Methods We selected samples with available fresh/frozen BM cells from consecutive treatment-naïve MDS pts who also underwent standard-of-care tests (CK, FISH, targeted 81-gene NGS for mutations). For OGM, ultra-high-molecular-weight-DNA was extracted, followed by labeling, linearization and imaging of DNA (Saphyr, Bionano) [median coverage:>300X]. The results were analyzed using de novo (>500 bp), rare variant (>5000 bp) and copy number (>500,000 bp) pipelines. The data was compared against 200 healthy controls to exclude common germline SVs. Clinical significance of the SVs was determined based on the location/overlap with the coding region of myeloid malignancy associated genes. The detection sensitivity was 10%. Results There were 76 treatment naïve MDS patients. Baseline characteristics, comprehensive cytogenetic scoring system (CCSS) and R-IPPS risk categories and somatic mutations are in Fig 1. OGM identified all clonal abnormalities detected by CK [CNAs, inversions, inter/intra-chromosomal translocations, dicentric, complex derivative chromosomes]. Precise mapping of SVs by OGM at gene-level allowed determining the status of clinically informative biomarkers such as TET2, MECOM, TP53 and KMT2A, without the need for confirmatory assays. Detailed gene-level characterization of different SVs included KMT2A-ELL [t(11;19)] in MDS with WT1 mut, t(9;11) with SYTL2 fusion (and not KMT2A), der(1;7) leading to del(7q) in MDS with GATA2 mut/IDH2 mutand t(1;3)(p36;q21) rearrangements with potential PRDM16 disruption in SF3B1 mut/RUNX1 mutMDS, among others. Using OGM, we mapped the sequence patterns in both samples with IM with high level of confidence. Additionally, OGM identified 23 cryptic, clinically significant SVs in 14 (18%) of 76 pts. These included deletions of TET2, KMT2A, and del(5q), KMT2A amplification in MDS with FLT3-ITD/DNMT3A mut/RAS mut, NUP98-PRRX2, MECOM rearrangement in TET mut mutated NK-MDS. In addition, there were SVs of uncertain significance: duplications of chr1 (PDE41P), deletions of chr21 (involving RUNX1), chr2 (DNMT3A, ASXL2), chr12 (ETV6) and chr22 (EP300) and der(16)t(12;16)(q21.1;q12.1). These cryptic SVs were noted across all R-IPSS risk categories (highest yield in very-low and low R-IPSS) and across all cytogenetic risk-groups (very-good to very-poor). In complex karyotype setting, OGM could resolve the markers and additional genetic material, and in most cases, showed a much higher the degree of complexity within the genome than was apparent by CK. Four pts showed SV patterns typical of chromothripsis/chromoplexy. The median number of mutations per pt was 1 (0-6). When compared to mutation subsets, cryptic SVs were only identified in pts with ≤3 mutations. Majority represented either MDS with TP53 mut (6, 29%) or SF3B1 mut/TET mut (deletions of TET2, KMT2A, NOTCH1 and EP300 genes). Conclusions Unbiased, high-throughput whole genome SVP revealed cryptic, clinically significant SVs in ~18% of MDS pts. OGM is a single-platform cytogenomic tool that can facilitate SVP at a gene-level resolution. This study provides strong support for further validation in expanded cohorts to guide clinical implementation and integration of SVP for routine work-up. Figure 1 Figure 1. Disclosures Wei: Daiichi Sanko: Research Funding. Kantarjian: Ipsen Pharmaceuticals: Honoraria; Amgen: Honoraria, Research Funding; Astellas Health: Honoraria; Astra Zeneca: Honoraria; AbbVie: Honoraria, Research Funding; KAHR Medical Ltd: Honoraria; NOVA Research: Honoraria; Ascentage: Research Funding; Aptitude Health: Honoraria; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Jazz: Research Funding; Immunogen: Research Funding; Daiichi-Sankyo: Research Funding; BMS: Research Funding; Precision Biosciences: Honoraria; Taiho Pharmaceutical Canada: Honoraria.

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Дисертації з теми "High and Ultra High Molecular Weight DNA"

1

Roukema, Mees. "High-speed spinning of ultra-high molecular weight polyethylene fibres." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 1991. http://irs.ub.rug.nl/ppn/291241077.

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Karanfilov, Christopher. "ION IMPLANTATION OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243981285.

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Burger, Nicolaas Daniel Lombard. "Failure analysis of ultra-high molecular weight polyethyelene acetabular cups." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-12142006-134036.

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Zhang, Zhijie. "A study of ultra-high-molecular-weight polyethylene, UHMWPE, foams." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60758.pdf.

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Boontongkong, Yot. "Orientation of channel die-compressed ultra-high molecular weight polyethylene." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/46093.

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Burger, N. D. L. (Nicolaas Daniel Lombard). "Failure analysis of ultra-high molecular weight polyethyelene acetabular cups." Thesis, University of Pretoria, 2005. http://hdl.handle.net/2263/30360.

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Owing to the crippling nature of arthritis, surgeons have been trying for well over a century to successfully treat this debilitating disease particularly when attacking the hip joint. In the early 1970s, Sir John Charnley started with total hip replacement as a solution to this ever-increasing problem. Many different designs were developed but all the designs revolved around a femoral stem, femoral head and acetabular component. Independent of the design, longevity of the implant remains a problem. The major cause of replacements, according to various hip registers, is due to aseptic loosening resulting from osteolysis. According to these registers, the average in-vivo life of a hip replacement is approximately 12 years. The main aim of this study was to determine the root cause of mechanical failure of the acetabular cups and to determine the origin of the excessive amount of ultra-high molecular weight polyethylene (UHMWPE) wear debris floating in the joint resulting in osteolysis. During the study, various techniques were used to investigate the acetabular components to try to establish the root cause of mechanical failure. These techniques included: 1. Visual inspection 2. Investigation making use of dye penetrant spray 3. Investigation under stereo microscope 4. Investigation making use of a scanning electron microscope 5. Electrophoresis 6. Mass-spectrometric analysis 7. Analysis of the synovial fluid on high-frequency linear-oscillation machine (SRV). The wear debris retrieved from the scar tissue surrounding the joints of a number of patients was also analysed. Apart from the obvious defects such as mechanical damage due to impingement, the main defect on which this study focuses is the wear patches found on the inside of the acetabular components. The wear areas were presented as areas where the surface layer of the UHMWPE was ripped off by adhering to the rotating femoral head. This type of failure is possible if localised overheating takes place resulting in the material either adhering to the rotating femoral head or the material being squeezed out under the prevailing pressure. Both these mechanisms were confirmed by the wear debris retrieved from the scar tissue, being either droplets of UHMWPE or whisker-like wear products. To confirm the existence of elevated temperatures the brown discolouring on the inside of the acetabular cups was analysed, making use of electrophoresis, mass-spectrometric analysis and scanning electron microscope recordings. In this part of the study, it was confirmed that localised temperatures on the bearing surface had reached at least 60°C during in-vivo service. This temperature was confirmed by inserting a thermocouple just under the surface of an acetabular cup and then measuring the temperature while in-vitro testing was taking place on a hip simulator. The wear debris as retrieved was also duplicated in laboratory experiments while the temperature on the surface of an acetabular cup was monitored. It was established that wear particles similar in shape and size were formed at temperatures in excess of 90°C. At temperatures above 50°C the UHMWPE had visually shown extensive increase in creep, indicating that at these temperatures the material softens sufficiently for this type of debris to be generated The overheating as described can also only occur if there is a lack of lubrication in the bearing couple. The synovial fluid from 12 patients was retrieved during revision surgery. This synovial fluid was then tested on a high-frequency linear-oscillation machine (Optimol SRV test machine) to determine the lubricity characteristics of the synovial fluid as retrieved. It was discovered that the load-carrying capability of the synovial fluid did not comply with the minimum requirements for a fluid to function as a lubricant. The final conclusion of this study is that excessive amounts of wear debris are generated due to the localised overheating of the bearing couple as a result of insufficient lubrication. The localised heat build-up results in excessive amounts of wear debris being generated and deposited in the joint area resulting in osteolysis.
Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2005.
Mechanical and Aeronautical Engineering
unrestricted

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Wernle, James David. "Micron-scale wear mechanisms in ultra high molecular weight polyethylene." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.

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8

Titone, John Carlos. "Supercritical carbon dioxide sterilization of ultra-high molecular weight polyethylene." Connect to resource, 2009. http://hdl.handle.net/1811/37004.

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9

Ruan, Shilun. "Multi-walled carbon nanotube reinforced ultra-high molecular weight polyethylene composites /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20RUAN.

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10

Ma, Yue. "Polymer grafted carbon nanotube reinforced ultra high molecular weight polyethylene fibre." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/45828.

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In this research, a series of experiments have been conducted to develop a high performance ultra-high molecular weight polyethylene (UHMWPE) fibre with improved mechanical properties. A novel process was developed whereby polyethylene grafted multi-walled carbon nanotubes (PE-g-MWCNTs) were used to reinforce UHMWPE fibre. PE-g-MWCNT/UHMWPE fibres with remarkable modulus and tensile strength of 125.5 GPa and 4.0 GPa, respectively, were successfully fabricated and showed definite potential for reducing the weight of body armour. A systematic study was carried out to investigate the effects of gel spinning conditions on tensile properties and morphologies of UHMWPE fibre. Spinning parameters, including polymer concentration, spinning temperature and winding-up speed, were selected and studied systematically and the spinning condition of UHMWPE fibre was optimized by design of experiment. Intensive experiments were conducted to investigate the feasibility of reinforcing UHMWPE fibre with pristine multi-walled carbon nanotubes (MWCNTs). Various mechanical methods include ultra-sonication, ball milling, microfluidizing, etc. were applied for dispersing pristine MWCNTs. Studies on tensile properties and morphologies of formed MWCNT/ UHMWPE fibre demonstrated that pristine MWCNTs tend to exist in micro-meter size agglomerations and no improvement in tensile properties of the MWCNT/UHMWPE fibres was found. Finally, chemical functionalization of MWCNTs using a coupling agent and polymer grafting technology was studied. The effective modulus and strength of MWCNTs were calculated based on the ‘rule of mixture’. Compared to coupling agent functionalization, polymer grafting has been found to be more effective in improving reinforcement of MWCNTs in UHMWPE fibre due to a stronger load transfer on the interface. The reinforcement mechanism of polymer grafted MWCNTs was analyzed based on experimental observations.

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Книги з теми "High and Ultra High Molecular Weight DNA"

1

Gsell, RA, HL Stein, and JJ Ploskonka, eds. Characterization and Properties of Ultra-High Molecular Weight Polyethylene. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 1998. http://dx.doi.org/10.1520/stp1307-eb.

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2

1944-, Gsell Ray A., Stein Harvey L. 1947-, Ploskonka John J. 1951-, ASTM Committee F-4 on Medical and Surgical Materials and Devices., and Symposium on Characterization and Properties of Ultra-high Molecular Weight Polyethylene (1996 : New Orleans, La.), eds. Characterization and properties of ultra-high molecular weight polyethylene. West Conshohocken, PA: ASTM, 1998.

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3

-G, Willert H., Buchhorn G, and Eyerer Peter, eds. Ultra-high molecular weight polyethylene as biomaterial in orthopedic surgery. Toronto: Hogrefe & Huber Publishers, 1991.

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4

J, Patterson W., and United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch., eds. Formulation/cure technology for ultra-high molecular weight silphenylene-siloxane polymers. [Washington, DC]: National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1985.

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5

Hundley, N. H. Formulation/cure technology for ultra-high molecular weight silphenylene-siloxane polymers. [Washington, DC]: National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1985.

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6

Kurtz, SM, RA Gsell, and J. Martell, eds. Crosslinked and Thermally Treated Ultra-High Molecular Weight Polyethylene for Joint Replacements. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2004. http://dx.doi.org/10.1520/stp1445-eb.

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7

Kurtz, Steven M. The UHMWPE handbook: Ultra-high molecular weight polyethylene in total joint replacement. Amsterdam: Academic Press, 2004.

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8

Yu, Jie. Oxidation of ultra high molecular weight polyethylene (UHMWPE) containing traces of cobaltion. Ottawa: National Library of Canada, 2000.

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9

Ji, Tiezheng. Preparation and electrical properties of carbon black, ultra-high molecular weight polyethylene composites. Berlin: Köster, 2004.

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10

Ji, Tiezheng. Preparation and electrical properties of carbon black, ultra-high molecular weight polyethylene composites. Berlin: Köster, 2004.

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Частини книг з теми "High and Ultra High Molecular Weight DNA"

1

Gooch, Jan W. "Ultra High Molecular Weight." In Encyclopedic Dictionary of Polymers, 778. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_12286.

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2

Gooch, Jan W. "Ultra-High-Molecular-Weight Polyethylene." In Encyclopedic Dictionary of Polymers, 778. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_12287.

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3

Bashford, David. "Ultra High Molecular Weight Polyethylene (UHMW PE)." In Thermoplastics, 162. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-1531-2_19.

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4

Bouchez, David, and Christine Camilleri. "High Molecular Weight DNA Extraction from Arabidopsis." In Arabidopsis Protocols, 61–70. Totowa, NJ: Humana Press, 1998. http://dx.doi.org/10.1385/0-89603-391-0:61.

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5

Zhang, Shasha, and Alejandro Sánchez Alvarado. "Planarian High Molecular Weight DNA Isolation by Spooling." In Methods in Molecular Biology, 277–84. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-7802-1_8.

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6

Brown, Susan J., and Michelle Coleman. "Isolation of High Molecular Weight DNA from Insects." In Methods in Molecular Biology, 27–32. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-8775-7_3.

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7

Chung, B., and A. E. Zachariades. "Viscoelastic Behavior of Ultra High Molecular Weight Polyethylene Pseudogels." In Reversible Polymeric Gels and Related Systems, 22–32. Washington, DC: American Chemical Society, 1987. http://dx.doi.org/10.1021/bk-1987-0350.ch002.

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8

Murphy, Nicholas M., Colin W. Pouton, and Helen R. Irving. "High Molecular Weight DNA Enrichment with Peptide Nucleic Acid Probes." In Methods in Molecular Biology, 73–85. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-6750-6_4.

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9

Costa, L., P. Bracco, and E. M. del Brach Prever. "The Crosslinked Ultra-high Molecular Weight Polyethylene: Risk and Limitation." In Bioceramics in Joint Arthroplasty, 89–92. Heidelberg: Steinkopff, 2004. http://dx.doi.org/10.1007/978-3-7985-1968-8_16.

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10

Eyerer, Peter. "Degradation of Ultra High Molecular Weight Polyethylene for Joint Endoprostheses." In Materials Sciences and Implant Orthopedic Surgery, 345–54. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4474-9_26.

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Тези доповідей конференцій з теми "High and Ultra High Molecular Weight DNA"

1

Ghasemi, Hadi, Nagarajan Thoppey, Xiaopeng Huang, James Loomis, Xiaobo Li, Jonathan Tong, Jianjian Wang, and Gang Chen. "High thermal conductivity ultra-high molecular weight polyethylene (UHMWPE) films." In 2014 IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm). IEEE, 2014. http://dx.doi.org/10.1109/itherm.2014.6892287.

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2

Novotná, Z., V. Lacmanová, S. Rimpelová, P. Juřik, M. Polívková, and V. Švorčik. "Biocompatibility of modified ultra-high-molecular-weight polyethylene." In SPIE Nanoscience + Engineering, edited by Hooman Mohseni, Massoud H. Agahi, and Manijeh Razeghi. SPIE, 2016. http://dx.doi.org/10.1117/12.2237379.

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3

Van Citters, Douglas W., Ashley E. Levack, and Francis E. Kennedy. "Wear of Highly Crystalline Ultra-High Molecular Weight Polyethylene." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71175.

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Highly crystalline ultra-high molecular weight polyethylene (UHMWPE) has historically experienced little success as a bearing material in total joint arthroplasty due to oxidation related fatigue failures. Recent sterilization and treatment advances have reduced or eliminated the risk of oxidation, allowing for a renewed interest in this particular material. The current study investigates the wear resistance of a highly crystalline UHMWPE in comparison to clinically relevant control materials. The highly crystalline material exhibits a wear rate superior to never irradiated material, and similar to irradiated material. The wear rate reduction is attributed to the larger crystallites’ ability to slow subsurface crack growth.

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4

Suyitno and Lazuardi Pujilaksono. "Fatigue crack propagation of ultra-high molecular weight polyethylene." In 2017 7th International Annual Engineering Seminar (InAES). IEEE, 2017. http://dx.doi.org/10.1109/inaes.2017.8068563.

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5

Hooks, D. E., J. M. Lang, J. D. Coe, and D. M. Dattelbaum. "High pressure deep-release impact experiments on high density and ultra-high molecular weight polyethylene." In SHOCK COMPRESSION OF CONDENSED MATTER - 2017: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter. Author(s), 2018. http://dx.doi.org/10.1063/1.5044774.

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6

"Extraction of high-molecular-weight DNA from poplar plants for Nanopore sequencing." In Current Challenges in Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences Novosibirsk State University, 2019. http://dx.doi.org/10.18699/icg-plantgen2019-51.

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7

Gan, B. K., N. J. Nosworthy, P. K. Chu, M. M. M. Bilek, D. R. McKenzie, and C. G. Remedios. "Enhancement of hrp binding on plasmatreated ultra-high molecular weight polyethylene." In IEEE Conference Record - Abstracts. The 33rd IEEE International Conference on Plasma Science. IEEE, 2006. http://dx.doi.org/10.1109/plasma.2006.1707206.

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8

Panin, S. V., L. A. Kornienko, V. O. Alexenko, D. G. Buslovich, and Yu V. Dontsov. "Extrudable polymer-polymer composites based on ultra-high molecular weight polyethylene." In MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS-2017): Proceedings of the 11th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures. Author(s), 2017. http://dx.doi.org/10.1063/1.5017317.

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9

Sepulveda, M. E., J. M. Martinez-Tarifa, and J. Sanz-Feito. "Ultra high molecular weight polyethylene (UHMWPE): Dielectric strength and space charge characteristics." In 2013 IEEE International Conference on Solid Dielectrics (ICSD). IEEE, 2013. http://dx.doi.org/10.1109/icsd.2013.6619837.

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10

Nguyen, Long H., Shannon Ryan, Adrian C. Orifici, and Stephen J. Cimpoeru. "A penetration model for semi-infinite ultra-high molecular weight polyethylene composite." In 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/hvis2019-046.

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Abstract Ultra-high molecular weight polyethylene (UHMW-PE) composite has been shown to be an effective material for ballistic protection against blunt penetrators [1]. The material exhibits multiple stages of penetration, typically characterised by an initial local penetration phase followed by large bulge deformation of the back face [2]. The location at which transition occurs between the localised penetration stage and non-localised bulging stage is an important property of UHMW-PE composite armour. However, the conditions required to induce transition are poorly understood with a range of different mechanisms proposed to explain the behaviour [2,3], none of which can be used to predict the transition location within the target.

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Звіти організацій з теми "High and Ultra High Molecular Weight DNA"

1

Kelly, Daniel, and April Dawn Longhair. XPS and IR Characterization of Ultra-High Molecular Weight Polyethylene. Office of Scientific and Technical Information (OSTI), May 2015. http://dx.doi.org/10.2172/1179842.

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2

Fang, Hsu-Wei, Stephen M. Hsu, and Jan V. Sengers. Ultra-high molecular weight polyethylene wear particle effects on bioactivity. Gaithersburg, MD: National Institute of Standards and Technology, 2003. http://dx.doi.org/10.6028/nist.sp.1002.

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3

Zhang, Timothy G., Sikhanda S. Satapathy, Lionel R. Vargas-Gonzalez, and Shawn M. Walsh. Modeling Ballistic Response of Ultra-High-Molecular-Weight Polyethylene (UHMWPE). Fort Belvoir, VA: Defense Technical Information Center, July 2016. http://dx.doi.org/10.21236/ad1012075.

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4

Bly, Peter. Development of expedient ultra-high molecular weight aircraft arresting system panel installation procedures. Engineer Research and Development Center (U.S.), July 2020. http://dx.doi.org/10.21079/11681/37536.

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5

Brown, E. R. Evaluation of Ultra High Molecular Weight (UHMW) Polyethylene Panels for Aircraft Arresting Systems. Fort Belvoir, VA: Defense Technical Information Center, August 2009. http://dx.doi.org/10.21236/ada508608.

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6

Griep, Mark H., Victor Rodriguez-Santiago, Andres A. Bujanda, Josh Martin, Shashi P. Karna, and Daphne D. Pappas. Development of Thin-film Dye-sensitized Photoactive Materials on Ultra High Molecular Weight Polyethylene. Fort Belvoir, VA: Defense Technical Information Center, April 2012. http://dx.doi.org/10.21236/ada559275.

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7

Yamaleyeva, Dina, Paul Baker, and Shane Catledge. A Wear Evaluation of Ultra High Molecular Weight Polyethylene (UHMWPE) against Nanostructured Diamond-Coated Ti-6Al-4V Alloy. Journal of Young Investigators, September 2016. http://dx.doi.org/10.22186/jyi.31.3.21-26.

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8

Doyle, Jesse D., Nolan R. Hoffman, and M. Kelvin Taylor. Aircraft Arrestor System Panel Joint Improvement. U.S. Army Engineer Research and Development Center, August 2021. http://dx.doi.org/10.21079/11681/41342.

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Aircraft Arresting Systems (AAS) for military applications utilize sacrificial panels made of Ultra-High Molecular Weight polyethylene (UHMWPE) that are embedded into the pavement beneath the AAS cable to protect the pavement from cable damage. Problems have been observed with the materials and practices used to seal the UHMWPE panel joints from water and debris. Data obtained from laboratory and field studies were used make improvements to current practice for sealing UHMWPE panel joints. The study evaluated four joint-sealant materials, eight alternative surface treatment and preparation techniques to promote adhesion to UHMWPE, and seven joint-edge geometries. Bond-strength testing of joint-sealant specimens was conducted in the laboratory, followed by field evaluation of construction techniques. Field performance of the joint systems was monitored for 24 months after installation. Additionally, a thermal response model was developed to refine the joint design dimensions. Results confirmed that the best material to use was self-leveling silicone joint sealant. It was recommended that a dovetail groove be cut into the edge of UHMW panels to provide positive mechanical interlock and to reduce adhesive failures of the sealant. It was also recommended that the panel-to-panel joint-sealant reservoir be widened to prevent sealant compression damage.

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9

Christopher, David A., and Avihai Danon. Plant Adaptation to Light Stress: Genetic Regulatory Mechanisms. United States Department of Agriculture, May 2004. http://dx.doi.org/10.32747/2004.7586534.bard.

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Original Objectives: 1. Purify and biochemically characterize RB60 orthologs in higher plant chloroplasts; 2. Clone the gene(s) encoding plant RB60 orthologs and determine their structure and expression; 3. Manipulate the expression of RB60; 4. Assay the effects of altered RB60 expression on thylakoid biogenesis and photosynthetic function in plants exposed to different light conditions. In addition, we also examined the gene structure and expression of RB60 orthologs in the non-vascular plant, Physcomitrella patens and cloned the poly(A)-binding protein orthologue (43 kDa RB47-like protein). This protein is believed to a partner that interacts with RB60 to bind to the psbA5' UTR. Thus, to obtain a comprehensive view of RB60 function requires analysis of its biochemical partners such as RB43. Background & Achievements: High levels of sunlight reduce photosynthesis in plants by damaging the photo system II reaction center (PSII) subunits, such as D1 (encoded by the chloroplast tpsbAgene). When the rate of D1 synthesis is less than the rate of photo damage, photo inhibition occurs and plant growth is decreased. Plants use light-activated translation and enhanced psbAmRNA stability to maintain D1 synthesis and replace the photo damaged 01. Despite the importance to photosynthetic capacity, these mechanisms are poorly understood in plants. One intriguing model derived from the algal chloroplast system, Chlamydomonas, implicates the role of three proteins (RB60, RB47, RB38) that bind to the psbAmRNA 5' untranslated leader (5' UTR) in the light to activate translation or enhance mRNA stability. RB60 is the key enzyme, protein D1sulfide isomerase (Pill), that regulates the psbA-RN :Binding proteins (RB's) by way of light-mediated redox potentials generated by the photosystems. However, proteins with these functions have not been described from higher plants. We provided compelling evidence for the existence of RB60, RB47 and RB38 orthologs in the vascular plant, Arabidopsis. Using gel mobility shift, Rnase protection and UV-crosslinking assays, we have shown that a dithiol redox mechanism which resembles a Pill (RB60) activity regulates the interaction of 43- and 30-kDa proteins with a thermolabile stem-loop in the 5' UTR of the psbAmRNA from Arabidopsis. We discovered, in Arabidopsis, the PD1 gene family consists of II members that differ in polypeptide length from 361 to 566 amino acids, presence of signal peptides, KDEL motifs, and the number and positions of thioredoxin domains. PD1's catalyze the reversible formation an disomerization of disulfide bonds necessary for the proper folding, assembly, activity, and secretion of numerous enzymes and structural proteins. PD1's have also evolved novel cellular redox functions, as single enzymes and as subunits of protein complexes in organelles. We provide evidence that at least one Pill is localized to the chloroplast. We have used PDI-specific polyclonal and monoclonal antisera to characterize the PD1 (55 kDa) in the chloroplast that is unevenly distributed between the stroma and pellet (containing membranes, DNA, polysomes, starch), being three-fold more abundant in the pellet phase. PD1-55 levels increase with light intensity and it assembles into a high molecular weight complex of ~230 kDa as determined on native blue gels. In vitro translation of all 11 different Pill's followed by microsomal membrane processing reactions were used to differentiate among PD1's localized in the endoplasmic reticulum or other organelles. These results will provide.1e insights into redox regulatory mechanisms involved in adaptation of the photosynthetic apparatus to light stress. Elucidating the genetic mechanisms and factors regulating chloroplast photosynthetic genes is important for developing strategies to improve photosynthetic efficiency, crop productivity and adaptation to high light environments.

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