79 research outputs found
Homology of (n+1)-types and Hopf type formulas
AbstractThe tripleability of the category of crossed n-cubes is studied. The leading cotriple homology of these homotopy (n+1)-types is investigated, describing it as Hopf type formulas
Molecular genotyping of bacillus anthracis strains from Georgia and northeastern part of Turkey
Bacillus anthracis is the causal agent of anthrax and has a history of use
as a biological weapon. Anthrax cases occur worldwide and the disease is
endemic in certain regions. Here we describe a study of the genetic diversity
of B. anthracis strains in two endemic areas: The country of Georgia and the
Kars region of Turkey. Thirty Turkish isolates and thirty Georgian isolates were
subjected to Single Nucleotide Polymorphism (SNP) sub typing, followed by
higher-resolution genotyping using 25-loci variable-number tandem repeat
analysis (MLVA-25). Canonical SNP typing indicated that Turkish strains
belonged to both the A.Br.003 linage and the Australian 94 lineage. In light of
a recent analysis that placed the majority of Georgian B. anthracis isolates in
one phylogenetic group, we screened the Turkish strains using a previously
developed Georgian SNP panel. Minimal diversity was observed among the
Kars strains within the Georgian SNP lineage: all 30 of these strains grouped
with A.Br.026, ten strains were derived from A.Br.028, and only two isolates
belonged to A.Br.029. According to the results of MLVA-25 genotyping, all 30
Turkish strains belong to two clusters. Cluster A is more diverse than cluster
B. Our results suggest that B. anthracis strains originating from Georgia and
the northeastern part of Turkey are genetically interrelated, which could be
explained by the geographic proximity of the countries
Human Oral Mucosa Tissue-Engineered Constructs Monitored by Raman Fiber-Optic Probe
In maxillofacial and oral surgery, there is a need for the development of tissue-engineered constructs. They are used for reconstructions due to trauma, dental implants, congenital defects, or oral cancer. A noninvasive monitoring of the fabrication of tissue-engineered constructs at the production and implantation stages done in real time is extremely important for predicting the success of tissue-engineered grafts. We demonstrated a Raman spectroscopic probe system, its design and application, for real-time ex vivo produced oral mucosa equivalent (EVPOME) constructs noninvasive monitoring. We performed in vivo studies to find Raman spectroscopic indicators for postimplanted EVPOME failure and determined that Raman spectra of EVPOMEs preexposed to thermal stress during manufacturing procedures displayed correlation of the band height ratio of CH2 deformation to phenylalanine ring breathing modes, giving a Raman metric to distinguish between healthy and compromised postimplanted constructs. This study is the step toward our ultimate goal to develop a stand-alone system, to be used in a clinical setting, where the data collection and analysis are conducted on the basis of these spectroscopic indicators with minimal user intervention.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140248/1/ten.tec.2013.0622.pd
Tissue-Engineered Constructs of Human Oral Mucosa Examined by Raman Spectroscopy
A noninvasive quality monitoring of tissue-engineered constructs is a required component of any successful tissue-engineering technique. During a 2-week production period, ex vivo produced oral mucosa-equivalent constructs (EVPOMEs) may encounter adverse culturing conditions that might compromise their quality and render them ineffective. We demonstrate the application of near-infrared Raman spectroscopy to in vitro monitoring of EVPOMEs during their manufacturing process, with the ultimate goal of applying this technology in situ to monitor the grafted EVPOMEs. We identify Raman spectroscopic failure indicators for less-than optimal EVPOMEs that are stressed by higher temperature and exposure to higher than normal concentration of calcium ions. Raman spectra of EVPOMEs exposed to thermal and calcium stress showed correlation of the band height ratio of CH2 deformation to phenylalanine ring breathing modes, providing a Raman metric to distinguish between viable and nonviable constructs. We compared these results to histology and glucose consumption measurements, demonstrating that Raman spectroscopy is more sensitive and specific to changes in proteins' secondary structure not visible by HandE histology. We also exposed the EVPOMEs to rapamycin, a cell growth inhibitor and cell proliferation capacity preserver, and distinguished between EVPOMEs pretreated with 2?nM rapamycin and controls, using the ratio of the Amide III envelope to the phenylalanine band as an indicator.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140240/1/ten.tec.2012.0287.pd
Molecular genotyping of bacillus anthracis strains from Georgia and northeastern part of Turkey
Bacillus anthracis is the causal agent of anthrax and has a history of use
as a biological weapon. Anthrax cases occur worldwide and the disease is
endemic in certain regions. Here we describe a study of the genetic diversity
of B. anthracis strains in two endemic areas: The country of Georgia and the
Kars region of Turkey. Thirty Turkish isolates and thirty Georgian isolates were
subjected to Single Nucleotide Polymorphism (SNP) sub typing, followed by
higher-resolution genotyping using 25-loci variable-number tandem repeat
analysis (MLVA-25). Canonical SNP typing indicated that Turkish strains
belonged to both the A.Br.003 linage and the Australian 94 lineage. In light of
a recent analysis that placed the majority of Georgian B. anthracis isolates in
one phylogenetic group, we screened the Turkish strains using a previously
developed Georgian SNP panel. Minimal diversity was observed among the
Kars strains within the Georgian SNP lineage: all 30 of these strains grouped
with A.Br.026, ten strains were derived from A.Br.028, and only two isolates
belonged to A.Br.029. According to the results of MLVA-25 genotyping, all 30
Turkish strains belong to two clusters. Cluster A is more diverse than cluster
B. Our results suggest that B. anthracis strains originating from Georgia and
the northeastern part of Turkey are genetically interrelated, which could be
explained by the geographic proximity of the countries
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