This self-contained textbook is an informal introduction to optimization through the use of numerous illustrations and applications. The focus is on analytically solving optimization problems with a ...finite number of continuous variables. In addition, the authors provide introductions to classical and modern numerical methods of optimization and to dynamic optimization.
The survival of bacteria under antibiotic therapy varies in nature and is based on the bacterial ability to employ a wide range of fundamentally different resistance mechanisms. This great diversity ...requires a disambiguation of the term ‘resistance’ and the development of a more precise classification of bacterial survival strategies during contact with antibiotics. The absence of a unified definition for the terms ‘resistance’, ‘tolerance’ and ‘persistence’ further aggravates the imperfections of the current classification system.
This review suggests a number of original classification criteria that will take into account (1) the bacterial ability to replicate in the presence of antimicrobial agents, (2) existing evolutionary stability of a trait within a species, and (3) the presence or absence of specialized genes that determine the ability of a microorganism to decrease its own metabolism or switch it completely off.
This review describes potential advantages of the suggested classification system, which include a better understanding of the relationship between bacterial survival in the presence of antibiotics and molecular mechanisms of cellular metabolism suppression, the opportunity to pinpoint targets to identify a true bacterial resistance profile. The true resistance profile in turn, could be used to develop effective diagnostic and antimicrobial therapy methods, while taking into consideration specific bacterial survival mechanisms.
•A microarray-based method was evaluated to identify ctDNA BRAF mutations in melanoma patients.•The presence of BRAF mutations in cfDNA correlates with tumor progression (P=0.005).•Increased levels ...of cfDNA correlate with tumor progression (P=0.02).•Coincidence of genotypes between the tumor DNA and ctDNA was 65%.
Background: Circulating tumor DNA (ctDNA) holds great potential for cancer therapy and can provide diagnostic and prognostic information before and during treatment.
Methods: Plasma DNA samples from 97 melanoma patients, 20 healthy donors and 3 patients with benign skin tumors were analyzed by microarray analysis and droplet digital PCR (ddPCR).
Results: A microarray for simultaneous detection of six BRAF V600 mutations in ctDNA has been developed. The method allows the detection of 0.05% mutated DNA from WT DNA background. For paired samples (pre-surgery plasma and tumor tissue) isolated from 74 patients, the concordance of genotypes between tumor DNA and ctDNA was 65% (48/74). BRAF mutations in ctDNA were detected in 27/50 patients with BRAF-positive tumors and in 3/24 patients with BRAF wild-type tumors. The presence of ctDNA BRAF mutations in 23 plasma samples from melanoma patients undergoing therapy correlated significantly with tumor progression (P=0.005). The increase in cell-free DNA levels measured by ddPCR also correlated with disease progression (P=0.02). The concordance of results obtained by microarray identification of BRAF mutations and those obtained by ddPCR was 91%.
Conclusion: The novel microarray-based approach can be a useful non-invasive tool for accurate identification of ctDNA BRAF mutations to monitor disease progression.
Focusing on previously neglected cultural expressions of
colonial-period Korean socialism such as Marxist philosophy,
Marxist historiography, and travelogues by socialist writers, The
Red Decades ...reveals Marxian socialism as a cultural phenomenon of
colonial-age Korea. Providing an account of the social composition
of the Communist milieu in 1920s and 1930s Korea and outlining the
aims of the colonial-period Communist movement as formulated in
programmic documents, this text offers a rich, nuanced description
of the microcosm of Korean Communism-a setting of factional
alignments, pilgrimages to Moscow, extended stays of the Korean
revolutionaries as exiles in China and the Soviet Union, and a
polylingual environment with Chinese, Japanese, English, and
Russian being equally important as the idioms of socialist
propagation and international networking. Placing the endeavors of
colonial-age Communists within a global historical context allows
for dissections of how Korean socialists' ideals interacted with
the realities of the conservative turn taking place in the Soviet
Union since the late 1920s, as well as considering the implication
of Stalinism for Korean revolutionary culture. Yet this analysis
also focuses on the individuals involved, especially on their
persistent issue of factionalism in the Korean Communist movement
and on the role of underground radicalism in shaping the subaltern
subjectivities of the participants. The Red Decades discusses the
world-historical place of "alternative modernity" that colonial-age
socialists of Korea were pursuing. Based on a wealth of Japanese,
Korean, Russian, and Chinese primary sources, including the
Korea-related parts of the archives of Comintern, an under-utilized
resource in Anglophone scholarship. The research also accommodates
the achievements of the last decades, from South Korean, Japanese,
Chinese, Anglophone and Russophone academic worlds. The breadth of
this study situates the philosophical, historiographical, and
political practices of Marxism of colonial Korea in the global
historical perspective and simultaneously explores the long-lasting
influences of the Communist movement in post-1945 North and South
Korea.
Introduction. Stenotrophomonas maltophilia is an opportunistic pathogen that is intrinsically resistant to a wide range of antibiotics. The bacterium is associated with a number of serious diseases ...and makes a significant contribution to the pathogenesis of polymicrobial infections. S. maltophilia has a wide range of virulence factors, information about which is currently presented in the form of scattered and unconsolidated data.
Purposes and objectives: critically analyze and summarize current data regarding the molecular-genetic aspects of S. maltophilia virulence for better understanding of the pathogenesis of infections associated with this pathogen.
Materials and methods. An analysis of information from 80 modern literary sources devoted to the study of the virulent properties of S. maltophilia at the molecular-genetic level has been carried out. The analysis focuses on the mechanisms of production of virulence factors and their genetic determinants.
Results.The molecular mechanisms of virulence that determine the infectious process caused by S. maltophilia have been analyzed and summarized, including the adhesive function of the surface structures of the bacterial cell (lipopolysaccharides, pili/fimbriae, flagella), the production of extracellular enzymes, the ability to form biofilms on abiotic surfaces and on the tissues of the macroorganism, the functioning of efflux pumps, secretion of small molecules into the external environment by the intercellular information exchange system Quorum Sensing, as well as the influence of iron metabolism on the virulence properties of S. maltophilia.
Conclusion. The adaptation mechanisms that allow S. maltophilia to adapt to new habitat niches and survive in the human body and unfavorable environmental conditions have been poorly studied. An analytical review summarizing current information on the molecular-genetic aspects of S. maltophilia virulence will be of interest to clinicians and researchers studying the fundamental mechanisms of virulence.
The structural-phase state of two-dimensional (d = 1 - 3 ML) coatings before and after annealing and that of Fe nanolayers (d = 4 - 10 ML) were investigated on Si (001)2×1 by electron spectroscopy ...methods of Auger-electrons and energy losses. The room (30 °С) and lowed (≤ 1250 °С) temperatures of the Si (001) substrate and Fe vapor, respectively, were used during Fe deposition. This study showed the following. An ordered two-dimensional 1×1 phase of Fe stable up to 600 °C and then a Fe2Si wetting coating stable at 250 °C form near the thickness 1 ML and 3 ML, respectively. Fe deposition on this Fe2Si coating leads to the one-after-another formation of the Fe3Si, the Si-in-Fe solution, and then a stable up to 250 °C Fe nanofilm with segregated Si.
In the course of developing an assay to identify genes responsible for antibiotic resistance in gram-negative bacteria, it has been found that standard (not DNA-free) Taq DNA polymerases were ...contaminated with blaTEM gene fragments that varied in length and quantities. The complete blaTEM gene sequence was either absent or was detected in infinitesimal amounts. We developed an approach to avoid false-positive findings caused by contaminating blaTEM gene sequences in conventional polymerases. The method is based on selection of a target sequence to be detected within the blaTEM gene in such a way that the chosen sequence is amplified with primers incapable of amplifying contaminating DNA sequences of the polymerase.
•Conventional Taq DNA polymerases are contaminated with the blaTEM gene sequences.•The complete blaTEM gene sequence was not found, but its fragments were revealed.•One unit of enzymes contained 102–104 copies of the contaminating DNA fragments.•A method to identify the blaTEM gene using standard polymerases was developed.
In the course of developing an assay to identify genes responsible for antibiotic resistance in gram-negative bacteria, it has been found that standard (not DNA-free) Taq DNA polymerases were ...contaminated with bla
gene fragments that varied in length and quantities. The complete bla
gene sequence was either absent or was detected in infinitesimal amounts. We developed an approach to avoid false-positive findings caused by contaminating bla
gene sequences in conventional polymerases. The method is based on selection of a target sequence to be detected within the bla
gene in such a way that the chosen sequence is amplified with primers incapable of amplifying contaminating DNA sequences of the polymerase.
Biomechanics in Sport is a unique reference text prepared by the leading world experts in sport biomechanics. Over thirty chapters cover a broad spectrum of topics, ranging from muscle mechanics to ...injury prevention, and from aerial movement to wheelchair sport. The biomechanics of sports including running, skating, skiing, swimming, jumping in athletics, figure skating, ski jumping, diving, javelin and hammer throwing, shot putting, and striking movements are all explained.
The steady rise in the spread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) requires rapid and reliable methods to identify resistant strains. The ...current molecular methods to detect MTB resistance to second-line drugs either do not cover an extended spectrum of mutations to be identified or are not easily implemented in clinical laboratories. A rapid molecular technique for the detection of resistance to second-line drugs in M. tuberculosis has been developed using hybridisation analysis on microarrays.
The method allows the identification of mutations within the gyrA and gyrB genes responsible for fluoroquinolones resistance and mutations within the rrs gene and the eis promoter region associated with the resistance to injectable aminoglycosides and a cyclic peptide, capreomycin. The method was tested on 65 M. tuberculosis clinical isolates with different resistance spectra that were characterised by their resistance to ofloxacin, levofloxacin, moxifloxacin, kanamycin and capreomycin. Also, a total of 61 clinical specimens of various origin (e.g., sputum, bronchioalveolar lavage) were tested.
The sensitivity and specificity of the method in the detection of resistance to fluoroquinolones were 98% and 100%, respectively, 97% and 94% for kanamycin, and 100% and 94% for capreomycin. The analytical sensitivity of the method was approximately 300 genome copies per assay. The diagnostic sensitivity of the assay ranging from 67% to 100%, depending on the smear grade, and the method is preferable for analysis of smear-positive specimens.
The combined use of the developed microarray test and the previously described microarray-based test for the detection of rifampin and isoniazid resistance allows the simultaneous identification of the causative agents of MDR and XDR and the detection of their resistance profiles in a single day.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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