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Journal articles on the topic 'Fragmentation'

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Author: Grafiati

Published: 4 June 2021

Last updated: 31 July 2024

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1

Payami, M. "Stabilized jellium model and structural relaxation effects on the fragmentation energies of ionized silver clusters." Canadian Journal of Physics 82, no. 3 (March 1, 2004): 239–47. http://dx.doi.org/10.1139/p04-004.

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Using the stabilized jellium model (SJM) in two schemes of "relaxed" and "rigid", we calculate the dissociation energies and the fission-barrier heights for the binary fragmentations of singly-ionized and doubly-ionized Ag clusters. In the calculations, we assume spherical geometries for the clusters. Comparison of the fragmentation energies in the two schemes show differences that are significant. This result reveals the advantages of the relaxed SJM over the rigid SJM in dynamical processes such as fragmentation. Comparing the relaxed SJM results and experimental data on fragmentation energies, it is possible to predict the sizes of the clusters just before their fragmentations. PACS Nos.: 36.40.Qv, 36.40.c, 36.40.Wa

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2

Marinkovic, Aleksandar, Tatjana Vasiljevic, Mila Lausevic, and Bratislav Jovanovic. "ESI-MS spectra of 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones." Journal of the Serbian Chemical Society 74, no. 3 (2009): 223–35. http://dx.doi.org/10.2298/jsc0903223m.

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Twelve 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones were investigated by tandem mass spectrometry using positive as well as negative electrospray ionization. The influence of the electron affinity of the substituent and the steric effect on the fragmentation is discussed. Pyridinones with a substituent of low proton affinity show loss of water, HCN or benzene from the pyridinone ring in the first step of MS2 fragmentations. Oppositely, if a substituent with high proton affinity is present on the phenyl ring in the 4-position of pyridinone, the fragmentation paths are complex, depending mainly on the substituent proton acceptor ability. Elimination of neutral molecules CO, HCN, H2O, PhH (benzene) or Ph and CN radicals are fragmentation processes common for all compounds in the subsequent steps of the fragmentations.

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3

Bertoin, Jean. "Compensated fragmentation processes and limits of dilated fragmentations." Annals of Probability 44, no. 2 (March 2016): 1254–84. http://dx.doi.org/10.1214/14-aop1000.

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4

Shukla, Deepak, Guanghua Liu, Joseph P. Dinnocenzo, and Samir Farid. "Controlling parameters for radical cation fragmentation reactions: Origin of the intrinsic barrier." Canadian Journal of Chemistry 81, no. 6 (June 1, 2003): 744–57. http://dx.doi.org/10.1139/v03-078.

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CC bond cleavages of radical cations of 2-substituted benzothiazoline derivatives were investigated to determine the parameters controlling the fragmentation rate constants. In spite of the low oxidation potentials of the compounds, fragmentation rate constants greater than 1 × 106 s1 could be achieved through weakening of the fragmenting bond by substituents that stabilize the radical fragment and exert steric crowding. A quantitative assessment of the relative roles of radical stabilization vs. steric effects to weaken the fragmenting CC bond was achieved through DFT calculations. The calculated activation enthalpies matched reasonably well with the experimentally determined values. A thermokinetic analysis revealed that the fragmentations of benzothiazoline radical cations have relatively large intrinsic kinetic barriers, ascribed to the delocalized nature of the product radical and cation fragments. Interestingly, the same factors that lead to the large intrinsic barriers led, simultaneously, to large thermodynamic driving forces for the fragmentations, which should lead to lower activation barriers. These effects oppose each other kinetically and provide important insight into the design of fast radical ion fragmentation reactions.Key words: benzothiazoline, radical cation, fragmentation, steric effects, DFT.

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5

Brodskii, R. Ye. "Fragmentation of thin lenses." Functional materials 23, no. 2 (June 15, 2016): 279–92. http://dx.doi.org/10.15407/fm23.02.279.

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6

Hamilton, Brett, Mónica Díaz Sierra, Mary Lehane, Ambrose Furey, and Kevin J. James. "The fragmentation pathways of azaspiracids elucidated using positive nanospray hybrid quadrupole time-of-flight (QqTOF) mass spectrometry." Spectroscopy 18, no. 2 (2004): 355–62. http://dx.doi.org/10.1155/2004/949018.

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The azaspiracids, AZA1, AZA2 and AZA3, are the predominant shellfish toxins responsible for the human toxic syndrome, azaspiracid poisoning. Collision induced dissociation (CID) mass spectra were generated for azaspiracids using nano-electrospray ionisation (ESI) with a hybrid quadrupole time-of-flight (QqTOF) mass spectrometer in positive mode. Six main backbone fragmentations of the polyether skeleton of azaspiracids were observed as well as multiple neutral losses of water molecules from the parent and product ions. The characteristic charge-remote fragmentation of the carbon skeleton of azaspiracids produced nitrogenous ions. The three azaspiracids differ from one another by 14 Da due to methylation in the A- and E-rings. Three fragmentation pathways, involving cleavage of the E-ring, C27–C28 and G-ring, gave ions that were common to all azaspiracids. Another three fragmentations involving the A-ring, C-ring and C19–C20, were useful for distinguishing between azaspiracid analogues. Multiple tandem ion‒trap mass spectrometry (MSn) was used to confirm the fragmentation pathways.

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7

Buré, Corinne, Olivier Boujard, Marylène Bertrand, Catherine Lange, and Agnès F. Delmas. "Collision-Induced Dissociation of Peptide Thioesters: The Influence of Peptide Length on Fragmentation." European Journal of Mass Spectrometry 11, no. 1 (February 2005): 31–34. http://dx.doi.org/10.1255/ejms.709.

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Five peptide thioesters of increasing length were fragmented using two processes, in-source and in-collision cell fragmentation, using an electrospray source coupled to a triple quadrupole mass spectrometer. Comparison of their fragmentations was made in regard to their length. The two fragmentation conditions show that the peptide length has no influence on structural information and that the fragmentation efficiency is higher for the smallest peptides than for the longest. The particularity of these peptide thioesters consists of the neutral loss of ethanethiol. The absence of the a3 fragment ion and the presence of the (a3–17) ion on the collision-induced dissociation mass spectra are noted.

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8

Lensu, Mikko. "Distribution of the number of fragmentations in continuous fragmentation." Journal of Physics A: Mathematical and General 31, no. 26 (July 3, 1998): 5705–15. http://dx.doi.org/10.1088/0305-4470/31/26/010.

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9

Gaaku, Godwin Yao, and Selina Ewoenam Ahorsu. "Social Fragmentation in Achebe’s Things Fall Apart and Head’s Maru: A Comparative Study." International Journal of Language and Literary Studies 5, no. 3 (August 22, 2023): 285–300. http://dx.doi.org/10.36892/ijlls.v5i3.1299.

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This qualitative research sought to do a comparative analysis of social fragmentation in Things Fall Apart and Maru. Textual analysis was employed to analyse, interpret and evaluate the two novels in the light of postcolonial criticism, focusing on otherness. The researchers engaged the texts in multiple readings to gain a descriptive understanding of them and take descriptive notes at every stage of reading. Excerpts were purposefully sampled from the novels and analysed thematically. The study revealed that in pre-colonial Africa, social fragmentation resulted from classism, patriarchy and bad tradition; hence, the society operates in a binary relationship. In colonial Africa, social fragmentation resulted from religion and racism. However, post-colonial Africa experienced the deepest form of social fragmentation; spiced by tribalism and other pre-colonial factors. The study concluded that both novels confirm the concept of ‘otherness’. So, future research can focus on emotional and structural fragmentations.

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10

Hassanain Elsayed, Yasser Mohammed. "Qrs-Complex Fragmentations and Right Ventricular Infarction in the Presence of Inferior Infarction with Triple-Vessels Disease; Bad Initials but a Good Outcome." Journal of Thoracic Disease and Cardiothoracic Surgery 3, no. 1 (January 15, 2022): 01–04. http://dx.doi.org/10.31579/2693-2156/032.

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Rationale: The term “fragmentation of the QRS complex” denotes the existence of high-frequency potentials (spikes) in the QRS-complex. It is either a marker for cardiac structural diseases inducing biventricular hypertrophy or any condition interfering with the normally homogeneous depolarization status inside the myocardium. An associated right ventricular infarction with inferior infarction maybe carry a risk impact and serious complications. Patient concerns: A 64-year-old married, farmer, heavy smoker, Egyptian male patient presented with acute severe chest pain and inferior with right ventricular ST-segment elevation myocardial infarction and fragmentation of the QRS complex. Diagnosis: QRS-complex fragmentations and right ventricular infarction in the presence of inferior infarction with the triple-vessels disease. Interventions: Electrocardiography, oxygenation, streptokinase intravenous infusion, echocardiography, and percutaneous transluminal coronary angioplasty. Outcomes: Dramatic response of acute inferior with right ventricular ST-segment elevation myocardial infarction and QRS-complex fragmentations to streptokinase. Lessons: Despite the presence of inferior and right ventricular ST-segment elevation myocardial infarction with QRS-complex fragmentations, but there is no correlation with the severity of the disease. Dramatic clinical and electrocardiographic response signifying the role of streptokinase and fibrinolytic. The presence of fragmentation of the QRS-complex may have a bidirectional impact from seriousness to complications.

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11

Liu, Yong Gang, Yong Liu, and Qun Ma. "Fragmentation Pathway of Acevaltrate by Electro-Spray Ionization Ion-Trap Mass Spectrometry." Advanced Materials Research 361-363 (October 2011): 1745–47. http://dx.doi.org/10.4028/www.scientific.net/amr.361-363.1745.

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The fragmentation pathway of acevaltrate was investigated by electro-spray ionization ion-trap mass spectrometry．Under the positive ion mode, pseudo-molecular [M+Na]+ could be easily obtained，and fragmentation pathway presented a certain regularity. One of the major fragmentations observed in the collision induced dissociation(CID) spectrum was loss of branched-chain, and the other was that three-membered oxygen-containing rings would break into aldehyde. These results might be used to forecast the structures of irodoids.

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12

Zhang, Pengwei, Wan Chan, Irene Ang, Rui Wei, Melody Lam, Kate Lei, and Terence Poon. "Gas-Phase Fragmentation Reactions of Protonated Cystine using High-Resolution Tandem Mass Spectrometry." Molecules 24, no. 4 (February 19, 2019): 747. http://dx.doi.org/10.3390/molecules24040747.

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Cystine is an important biomolecule in living systems. Although collision-induced dissociation (CID)-based tandem mass spectrometry (MS/MS) is commonly applied for identification and quantification of cystine in both biomedical and nutritional studies, gas-phase fragmentation reactions of cystine in CID has remained unclear. This may lead to improper assay design, which may in turn result in inaccurate test results. In the present study, gas-phase fragmentation reactions of protonated cystine in CID were characterized using high-resolution MS/MS and pseudo MS3. Fragmentations started from cleavages of disulfide bond (S–S) and carbon–sulfur bond (C–S). When cleaving at the S–S, protonated cysteine was generated as one of the predominant fragmentation products. Minor fragmentations started from the loss of H2O + CO and the loss of NH3. Our results reveal that the m/z 74 fragment ion, which is commonly used as a product ion of the transition (precursor/product ion pair) in selected reaction monitoring (SRM) assay for quantifying cystine, comprises two isobaric fragments originating from different parts of cystine. This indicates the need for careful selection of a stable isotope-labeled cystine molecule as an internal standard for SRM assays. Here, we provide a clear picture of the fragmentation reactions of protonated cystine in CID. It can serve as a useful guidance for designing MS/MS-based assays for cystine testing.

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13

Herrmann, Hans J., Falk K. Wittel, and Ferenc Kun. "Fragmentation." Physica A: Statistical Mechanics and its Applications 371, no. 1 (November 2006): 59–66. http://dx.doi.org/10.1016/j.physa.2006.04.087.

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14

Villermaux, E. "Fragmentation." Annual Review of Fluid Mechanics 39, no. 1 (January 2007): 419–46. http://dx.doi.org/10.1146/annurev.fluid.39.050905.110214.

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15

Kettle, Chris J. "Fragmentation genetics in tropical ecosystems: from fragmentation genetics to fragmentation genomics." Conservation Genetics 15, no. 6 (October 31, 2014): 1265–68. http://dx.doi.org/10.1007/s10592-014-0673-1.

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16

Duchamps, Jean-Jil. "Fragmentations with self-similar branching speeds." Advances in Applied Probability 53, no. 4 (November 22, 2021): 1149–89. http://dx.doi.org/10.1017/apr.2021.11.

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AbstractWe consider fragmentation processes with values in the space of marked partitions of $\mathbb{N}$, i.e. partitions where each block is decorated with a nonnegative real number. Assuming that the marks on distinct blocks evolve as independent positive self-similar Markov processes and determine the speed at which their blocks fragment, we get a natural generalization of the self-similar fragmentations of Bertoin (Ann. Inst. H. Poincaré Prob. Statist.38, 2002). Our main result is the characterization of these generalized fragmentation processes: a Lévy–Khinchin representation is obtained, using techniques from positive self-similar Markov processes and from classical fragmentation processes. We then give sufficient conditions for their absorption in finite time to a frozen state, and for the genealogical tree of the process to have finite total length.

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17

Zhou, Chunfang, Yuluan Zhao, Mingshun Long, and Xiubin Li. "How Does Land Fragmentation Affect Agricultural Technical Efficiency? Based on Mediation Effects Analysis." Land 13, no. 3 (February 25, 2024): 284. http://dx.doi.org/10.3390/land13030284.

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The scientific revelation of the mechanism underlying land fragmentation’s influence on agricultural technical efficiency is extremely important. This study utilized survey data from 305 villages across 12 provinces in Southern China in 2020 to assess technical efficiency through the application of the stochastic frontier production function. Moreover, we investigated the direct impact of land fragmentation on technical efficiency and the indirect impact transmitted through crop diversification and part-time farming by employing Tobit and mediating effect models, respectively. The key findings are as follows: (1) The sampled farmers, on average, operated 0.614 hectares of land with 17.395 plots, and the mean of their technical efficiency was 0.630. (2) The overall effect of land fragmentation on technical efficiency demonstrated a “U”-shaped relationship. (3) Crop diversification and part-time farming were mediating factors in the impact of land fragmentation on technical efficiency. Specifically, an “inverted U”-shaped relationship existed between land fragmentation and crop diversification, whereas a negative linear relationship was observed between land fragmentation and part-time farming. Conversely, crop diversification presented a positive linear relationship with technical efficiency, and part-time farming had an “inverted U”-shaped relationship with technical efficiency. (4) The impact of land fragmentation on technical efficiency varied across altitude zones. It is recommended to control land fragmentation based on local conditions, encourage crop diversification, and strengthen employment guidance and skills training for farmers to ensure the orderly transfer of land.

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18

Merkley, Nadine, Manal El-Saidi, and John Warkentin. "Radicals from fragmentation of benzyloxymethoxycarbenes in solution." Canadian Journal of Chemistry 78, no. 3 (March 1, 2000): 356–61. http://dx.doi.org/10.1139/v00-021.

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2-Benzyloxy-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazolines, including the parent as well as p-substituted analogues, undergo thermolysis at 100°C in benzene to afford a mixture of products. Two primary fragmentations of the oxadiazolines were identified. The major pathway involves 1,3-dipolar cycloreversion to N2 and the corresponding carbonyl ylides. The latter dissociate to acetone and the corresponding benzyloxy(methoxy)carbenes, which undergo fragmentation to ArCH2 and MeOCO radical pairs that recombine to afford methyl arylacetates. Carbene dimers were not observed, showing that the fragmentation process is faster than carbene dimerization. A second fragmentation pathway observed for the oxadiazolines is an alternative cycloreversion to the corresponding benzyl methyl carbonate and 2-diazopropane. Products from diazopropane included acetone azine and, in some instances, traces of propene.Key words: benzyloxy(methoxy)carbene, carbene, radical pair, rearrangement.

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19

Li, Wenqing, John Aloysius Zinda, and Zhiming Zhang. "Does the “Returning Farmland to Forest Program” Drive Community-Level Changes in Landscape Patterns in China?" Forests 10, no. 10 (October 22, 2019): 933. http://dx.doi.org/10.3390/f10100933.

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In China, the Returning Farmland to Forest Program (RFFP) has afforested large areas, transforming land and livelihoods. By impacting vegetation cover, it may also drive spatial pattern changes across landscapes. Most studies have focused on time series data as a means to determine the effectiveness of the program, but there is a paucity of community-level comparative studies. Twelve communities in Northwest Yunnan Province were selected to test whether the RFFP changed landscape patterns by testing the following hypotheses: with (or without) the RFFP, forest and shrubland fragmentations would decrease (or increase) and farmland fragmentation would increase (or decrease). Remote sensing images from 2000, 2010, and 2014 were used to compare the differences in landscape patterns. Survey data from 421 households were used to examine the socioeconomic and ecological factors that affect the differences in landscape fragmentation across communities. The results showed that landscape patterns and fragmentation metrics were not significantly different between communities with or without the RFFP, regardless of the class or landscape level. These communities showed consistent patterns of change in their fragmentation parameters between 2000 and 2014, with forest fragmentation decreasing and the fragmentation of farmland and the overall landscape increasing. The regression models suggest these changes were affected by the local natural conditions, socioeconomic patterns, policy implementation, and farmer livelihoods, with the proximity to market towns and elevation being significant factors. The RFFP alone did not directly drive the changes in landscape patterns for the considered region. For the new RFFP to effectively contribute to reducing fragmentation, managers of afforestation efforts should carefully consider livelihoods and biophysical factors that influence changes in landscape patterns.

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20

Kleshchev, Maxim, Alexander Osadchuk, and Ludmila Osadchuk. "Impaired semen quality, an increase of sperm morphological defects and DNA fragmentation associated with environmental pollution in urban population of young men from Western Siberia, Russia." PLOS ONE 16, no. 10 (October 22, 2021): e0258900. http://dx.doi.org/10.1371/journal.pone.0258900.

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Poor sperm morphology and an elevated DNA fragmentation level are considered to be related to spermiogenesis malfunctions as a result of genetic mutations and effects of environmental factors, including industrial pollution. Standardized cross-sectional population studies of sperm morphology defects and sperm DNA fragmentation, especially in regions with increased environmental pollution may be helpful to investigate an influence of industrial pollution and other population-related factors on spermiogenesis process. The aim of present study was to estimate an influence industrial pollution on sperm morphogenesis and sperm DNA fragmentation in men from the general population of the Western Siberia. The Novosibirsk and Kemerovo cities are located to same climatic conditions in Western Siberia but the Kemerovo city is characterized by increased environmental pollution especially by particulate matter (PM). The male volunteers living in Novosibirsk (n = 278) and Kemerovo (n = 258) were enrolled. Percentages of sperm morphological defects are counted after staining native ejaculate smears by Diff-Quick kits. DNA fragmentation was estimated by a SCSA technique. The residents of Kemerovo were characterized by lowered sperm count and sperm motility, elevated DNA fragmentation, poor sperm morphology and increased incidence of morphological effects of head (pyriform, elongated, round, abnormal acrosome and vacuolated chromatine), asymmetrical neck insertion and excess residual cytoplasm. Moreover, elevated DNA fragmentation was associated with lowered sperm count, sperm motility and increased percentages of several sperm morphology defects, with the place of residence affecting the relationships between conventional semen parameters, sperm morphology and DNA fragmentations. Our study suggests that excessive sperm head elongation and impaired acrosome formation can contribute to sperm morphology deterioration in men from polluted areas. Regional features in the relationships between sperm morphology, sperm count and DNA fragmentation were shown, suggesting an importance of studying sperm morphology pattern in men from different regions.

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21

Švrček, Vladimir. "Nanocrystalline silicon and carbon nanotube nanocomposites prepared by pulsed laser fragmentation." Pure and Applied Chemistry 80, no. 11 (January 1, 2008): 2513–20. http://dx.doi.org/10.1351/pac200880112513.

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This paper outlines the synthesis of nanocrystalline silicon (nc-Si) by nanosecond pulsed laser fragmentation of Si micrograins in liquid solutions, and characterization of the products. We compare micrograin fragmentations in deionized water, and in undoped and phosphorus-doped ethylpolysilicate (C2H5O[SiO(C2H5O)2]n C2H5) based polymers. We show that dissolution and subsequent laser fragmentation of micrograins is more efficient in both polymeric media than in water. In the case of water, micrograin surface wetting by ethanol prior to introduction into water is essential to achieve fragmentation. Prepared nc-Si/polymer nanocomposites display visible photoluminescence (PL) (~430 nm) at room temperature. The phosphorus polymer induces a blue shift of the PL peak. In addition, induced shock waves generated at sufficiently high laser irradiation intensities (>4.3 mJ/pulse) cause carbon nanotube (CNT) cavities to be filled by freshly prepared luminescent nc-Si/polymer nanocomposite.

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22

Han, Sang Beom, Yu-Chi Liu, Melina Setiawan, Isabelle Xin Yu Lee, Moushmi Patil, Hon Shing Ong, and Jodhbir S. Mehta. "Effects of Different Capsulotomy and Fragmentation Energy Levels on the Generation of Oxidative Stress following Femtosecond Laser-Assisted Cataract Surgery." Biomolecules 14, no. 3 (March 7, 2024): 318. http://dx.doi.org/10.3390/biom14030318.

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Purpose. This study was conducted to evaluate the effects of different capsulotomy and fragmentation energy levels on the production of oxidative free radicals following femtosecond laser-assisted cataract surgery (FLACS) with a low-energy platform. Methods. The experimental study included 60 porcine eyes (12 groups). In each group, capsulotomies with 90% or 150% energy, and fragmentations with 90%, 100%, or 150% energy or 150% with high spot density, respectively, were performed. Control samples were obtained from non-lasered eyes at the beginning (five eyes) and end (five eyes) of the experiment. In the clinical study, 104 eyes were divided into 5 groups, and they received conventional phacoemulsification (20 eyes), FLACS with 90% capsulotomy and 100% fragmentation energy levels without NSAIDs (16 eyes), FLACS with 90% (26 eyes) or 150% (22 eyes) capsulotomy energy levels, respectively, with a 100% fragmentation energy level and NSAIDs, and FLACS with 90% capsulotomy and 150% fragmentation energy levels and NSAIDs (20 eyes). Aqueous samples were analyzed for their malondialdehyde (MDA) and superoxide dismutase (SOD) levels. Results. In the experimental study, there were no significant differences in the MDA and SOD levels between the groups with different capsulotomy energy levels. An increase in the fragmentation energy from 100% to 150% led to significantly higher MDA levels in the groups with both 90% (p = 0.04) and 150% capsulotomy energy levels (p = 0.03), respectively. However, increased laser spot densities did not result in significant changes in MDA or SOD levels. In the clinical study, all four of the FLACS groups showed higher MDA levels than the conventional group. Similarly, the increase in the fragmentation energy from 100% to 150% resulted in significantly elevated levels of MDA and SOD, respectively. Conclusions. Although increasing the FSL capsulotomy energy level may not have increased free radicals, higher fragmentation energy levels increased the generation of aqueous free radicals. However, fragmentation with high spot density did not generate additional oxidative stress. Increased spot density did not generate additional oxidative stress, and this can be helpful for dense cataracts.

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23

Combes, Audrey, Soo Jin Choi, Cyril Pimentel, Hervé Darbon, Dietmar Waidelich, Denis Mestivier, and Jean-Michel Camadro. "Determination with Matrix-Assisted Laser Desorption/Ionization Tandem Time-of-Flight Mass Spectrometry of the Extensive Disulfide Bonding in Tarantula Venom Peptide Psalmopeotoxin I." European Journal of Mass Spectrometry 15, no. 4 (August 2009): 517–29. http://dx.doi.org/10.1255/ejms.1000.

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Psalmopeotoxin I (PcFK1) is a 33-residue peptide isolated from the venom of the tarantula Psalmopoeus cambridgei. This peptide specifically inhibits the intra-erythrocyte stage of Plasmodium falciparum in vitro. It contains six cysteine residues forming three disulfide bridges and belongs to the superfamily of natural peptides containing the inhibitor cystine knot (ICK) fold. We produced the wild-type and mutated forms of the recombinant peptide to examine the mechanism of action of PcFK1. The purified toxins were consistently produced as two isobaric peptides (r-PcFK1-1 and r-PcFK1-2) with different retention properties but identical anti-plasmodial biological activity. Comparison of 15N-NMR heteronuclear single quantum correlation spectra revealed that although rPcFK1-1 was highly structured, rPcFK1-2 does not have a stable three-dimensional structure. We used high-energy collision-induced fragmentation of the peptides with a matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometer to further investigate the structure of the native peptides in its natural form and produced in E. coli. The fragmentation spectra of the native peptides were very complex due to the occurrence in the spectrum of ions resulting from (1) cross-linking of fragments through a disulfide bridge and (2) asymmetric fragmentations of the disulfide bridges and (3) multiple neutral losses. The tandem mass spectrometry fragmentation pattern of r-PcFK1-1 was similar to that of the natural peptide isolated from crude venom, but r-PcFK1-2 had a clearly distinct fragmentation pattern, more closely resembling the fragmentation spectra of reduced and alkylated peptides. Observed ions could be attributed to specific fragments by comparing spectra between the wild-type and selected variants with point mutations (Y11W, R20T, Y26W, K28V). The disulfide connections in r-PcFK1-2 differed from those of the native peptide and showed a rare disulfide bridge between vicinal cysteine residues. The r-PcFK1_(R20T) variant showed a very limited fragmentation pattern when analyzed in positive mode but displayed much more fragmentation in negative mode pointing out the importance of the R20 residue in the fragmentation of PcFK1. Using the reductive matrix 1,5-diaminonaphtalene promoted strongly in source decay fragmentation of the peptides in MS mode. Our findings illustrated the critical role of the electronic environment around the central Cys18–Cys19 doublet in PcFK1 in internal fragmentation of the peptide.

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24

Voican, Mădălina. "Fragmentation of Public Contracts and Integrity." Perspectives of Law and Public Administration 13, no. 1 (March 25, 2024): 125–34. http://dx.doi.org/10.62768/plpa/2024/13/1/13.

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This article explores the impact of dividing government contracts into smaller components, highlighting the risks it poses to transparency and integrity in public procurement. Contract fragmentation can obscure decision-making process regarding public expenditure, reduce healthy competition, and facilitate corruption. Real-world examples illustrate these issues. The analysis highlights the need for strengthening public procurement regulations, increasing transparency, and promoting ethical conduct to mitigate these risks. By understanding the complex relationship between contract fragmentation and integrity, decision-makers and stakeholders can better protect public resources by promoting a fairer and more transparent business environment and upholding ethical standards in public procurement.

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25

Ding, Spencer C., and Y. M. Dennis Lo. "Cell-Free DNA Fragmentomics in Liquid Biopsy." Diagnostics 12, no. 4 (April 13, 2022): 978. http://dx.doi.org/10.3390/diagnostics12040978.

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Cell-free DNA (cfDNA) in bodily fluids has rapidly transformed the development of noninvasive prenatal testing, cancer liquid biopsy, and transplantation monitoring. Plasma cfDNA consists of a mixture of molecules originating from various bodily tissues. The study of the fragmentation patterns of cfDNA, also referred to as ‘fragmentomics’, is now an actively pursued area of biomarker research. Clues that cfDNA fragmentation patterns might carry information concerning the tissue of origin of cfDNA molecules have come from works demonstrating that circulating fetal, tumor-derived, and transplanted liver-derived cfDNA molecules have a shorter size distribution than the background mainly of hematopoietic origin. More recently, an improved understanding of cfDNA fragmentation has provided many emerging fragmentomic markers, including fragment sizes, preferred ends, end motifs, single-stranded jagged ends, and nucleosomal footprints. The intrinsic biological link between activities of various DNA nucleases and characteristic fragmentations has been demonstrated. In this review, we focus on the biological properties of cell-free DNA unveiled recently and their potential clinical applications.

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26

Scheu, Bettina, and Donald B. Dingwell. "Magma Fragmentation." Reviews in Mineralogy and Geochemistry 87, no. 1 (May 1, 2022): 767–800. http://dx.doi.org/10.2138/rmg.2021.87.16.

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27

Chen, Daniel, and Darrell Duffie. "Market Fragmentation." American Economic Review 111, no. 7 (July 1, 2021): 2247–74. http://dx.doi.org/10.1257/aer.20200829.

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We model a simple market setting in which fragmentation of trade of the same asset across multiple exchanges improves allocative efficiency. Fragmentation reduces the inhibiting effect of price-impact avoidance on order submission. Although fragmentation reduces market depth on each exchange, it also isolates cross-exchange price impacts, leading to more aggressive overall order submission and better rebalancing of unwanted positions across traders. Fragmentation also has implications for the extent to which prices reveal traders’ private information. While a given exchange price is less informative in more fragmented markets, all exchange prices taken together are more informative. (JEL D47, D82, G14)

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Sposito, Eliseu Savério, and Maria Encarnação Beltrão Sposito. "SOCIOSPACIAL FRAGMENTATION." Mercator 19, no. 6 (June 15, 2020): 1–12. http://dx.doi.org/10.4215/rm2020.e19015.

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29

Stoll, Hans R. "Market Fragmentation." Financial Analysts Journal 57, no. 4 (July 2001): 16–20. http://dx.doi.org/10.2469/faj.v57.n4.2461.

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30

Guariguata, Manuel R. "Connecting Fragmentation." Ecology 79, no. 4 (June 1998): 1472–73. http://dx.doi.org/10.1890/0012-9658(1998)079[1472:cf]2.0.co;2.

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31

Drago-Severson, Eleanor, Patricia Maslin-Ostrowski, and Alexander M. Hoffman. "Resisting Fragmentation." Journal of Research on Leadership Education 7, no. 1 (April 2012): 44–77. http://dx.doi.org/10.1177/1942775112440628.

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32

Pfaff, R., D. J. Morrissey, W. Benenson, M. Fauerbach, M. Hellström, C. F. Powell, B. M. Sherrill, M. Steiner, and J. A. Winger. "Fragmentation ofKr78projectiles." Physical Review C 53, no. 4 (April 1, 1996): 1753–58. http://dx.doi.org/10.1103/physrevc.53.1753.

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33

Webber, B. R. "Jet fragmentation." Journal of Physics G: Nuclear and Particle Physics 17, no. 10 (October 1, 1991): 1493–505. http://dx.doi.org/10.1088/0954-3899/17/10/004.

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34

Yang, Jingyue, Tung T. Hoang, and Gregory B. Dudley. "Alkynogenic fragmentation." Organic Chemistry Frontiers 6, no. 15 (2019): 2560–69. http://dx.doi.org/10.1039/c9qo00266a.

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35

Bertoin, Jean, and Servet Martínez. "Fragmentation energy." Advances in Applied Probability 37, no. 2 (June 2005): 553–70. http://dx.doi.org/10.1239/aap/1118858639.

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Motivated by a problem arising in the mining industry, we estimate the energy ε(η) that is needed to reduce a unit mass to fragments of size at most η in a fragmentation process, when η→0. We assume that the energy used in the instantaneous dislocation of a block of size s into a set of fragments (s1,s2,…) is sβφ(s1/s,s2/s,…), where φ is some cost function and β a positive parameter. Roughly, our main result shows that if α>0 is the Malthusian parameter of an underlying Crump-Mode-Jagers branching process (with α = 1 when the fragmentation is mass-conservative), then there exists a c∈(0,∞) such that ε(η)∼cηβ-α when β<α. We also obtain a limit theorem for the empirical distribution of fragments of size less than η that result from the process. In the discrete setting, the approach relies on results of Nerman for general branching processes; the continuous approach follows by considering discrete skeletons. In the continuous setting, we also provide a direct approach that circumvents restrictions induced by the discretization.

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36

Ernst, M. H., and G. Szamel. "Fragmentation kinetics." Journal of Physics A: Mathematical and General 26, no. 22 (November 21, 1993): 6085–91. http://dx.doi.org/10.1088/0305-4470/26/22/011.

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37

Zelman, Jerry. "Photophaco fragmentation." Journal of Cataract & Refractive Surgery 13, no. 3 (May 1987): 287–89. http://dx.doi.org/10.1016/s0886-3350(87)80072-x.

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38

Battersby, Jessamy. "Habitat fragmentation." Oryx 33, no. 01 (January 1999): 75. http://dx.doi.org/10.1017/s003060530003026x.

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39

Bertoin, Jean, and Servet Martínez. "Fragmentation energy." Advances in Applied Probability 37, no. 02 (June 2005): 553–70. http://dx.doi.org/10.1017/s0001867800000318.

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Abstract:

Motivated by a problem arising in the mining industry, we estimate the energy ε(η) that is needed to reduce a unit mass to fragments of size at most η in a fragmentation process, when η→0. We assume that the energy used in the instantaneous dislocation of a block of size s into a set of fragments (s 1,s 2,…) is s βφ(s 1/s,s 2/s,…), where φ is some cost function and β a positive parameter. Roughly, our main result shows that if α>0 is the Malthusian parameter of an underlying Crump-Mode-Jagers branching process (with α = 1 when the fragmentation is mass-conservative), then there exists a c∈(0,∞) such that ε(η)∼cηβ-α when β<α. We also obtain a limit theorem for the empirical distribution of fragments of size less than η that result from the process. In the discrete setting, the approach relies on results of Nerman for general branching processes; the continuous approach follows by considering discrete skeletons. In the continuous setting, we also provide a direct approach that circumvents restrictions induced by the discretization.

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40

Gonnermann, Helge M. "Magma Fragmentation." Annual Review of Earth and Planetary Sciences 43, no. 1 (May 30, 2015): 431–58. http://dx.doi.org/10.1146/annurev-earth-060614-105206.

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41

Inutsuka, Shu-ichiro, and Toru Tsuribe. "Filament Fragmentation." Symposium - International Astronomical Union 200 (2001): 391–400. http://dx.doi.org/10.1017/s0074180900225448.

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The formation and evolution processes of magnetized filamentary molecular clouds are investigated in detail by linear stability analyses and non-linear numerical calculations. A one-dimensionally compressed self-gravitating sheet-like cloud breaks up into filamentary clouds. The directions of the longitudinal axes of the resulting filaments are perpendicular to the directions of magnetic field lines unless the column density of the sheet is very small. These magnetized filaments tend to collapse radially without characteristic density, length, and mass scale for the further fragmentation during the isothermal phase. The characteristic minimum mass for the final fragmentation is obtained by the investigation of thermal processes. The essential points of the above processes are analytically explained in terms of the basic physics. A theory for the expected mass function of dense molecular cloud cores is obtained. The expected mean surface density of companions of dense cores is also discussed.

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42

Soler, Mark, and Carole Shauffer. "Fighting Fragmentation." Education and Urban Society 25, no. 2 (February 1993): 129–40. http://dx.doi.org/10.1177/0013124593025002002.

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43

Brown, Wilbur K. "Universal fragmentation." Astrophysics and Space Science 121, no. 2 (1986): 351–55. http://dx.doi.org/10.1007/bf00653707.

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44

Kim, Eunja, Young Hee Lee, and Jae Young Lee. "Fragmentation ofC60andC70clusters." Physical Review B 48, no. 24 (December 15, 1993): 18230–34. http://dx.doi.org/10.1103/physrevb.48.18230.

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45

Battersby, Jessamy. "Habitat fragmentation." Oryx 33, no. 1 (January 1999): 75–77. http://dx.doi.org/10.1046/j.1365-3008.1999.00045.x.

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46

Brax, Philippe, and Amol Upadhye. "Chameleon fragmentation." Journal of Cosmology and Astroparticle Physics 2014, no. 02 (February 11, 2014): 018. http://dx.doi.org/10.1088/1475-7516/2014/02/018.

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47

Kabat-Zinn, Jon. "No Fragmentation." Mindfulness 9, no. 2 (March 15, 2018): 669. http://dx.doi.org/10.1007/s12671-018-0935-y.

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48

Heimann, Tomas M. "Ultrasonic Fragmentation." Archives of Surgery 120, no. 10 (October 1, 1985): 1200. http://dx.doi.org/10.1001/archsurg.1985.01390340092020.

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49

Norby, Aaron. "Against Fragmentation." Thought: A Journal of Philosophy 3, no. 1 (March 2014): 30–38. http://dx.doi.org/10.1002/tht3.110.

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50

Ahmad @ Mohamed, Nurulanis, Nor Nazihah Chuweni, and Andrea Blake. "Land Fragmentation and Socio-Economic Wellbeing." Environment-Behaviour Proceedings Journal 8, no. 23 (March 25, 2023): 185–91. http://dx.doi.org/10.21834/ebpj.v8i23.4467.

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Land fragmentation results in reduced agricultural productivity, lack of efficiency, and diminished viability of the land. This study investigates land fragmentation's causes and socio-economic impacts, aiming to develop a conceptual model. Thematic analysis was employed to undertake a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. The findings indicated that land fragmentation resulted in disorganization regarding location and space. This study guides land authorities and urban planners in providing fundamental knowledge to improve land management practices. Keywords: Land Fragmentation; Socio-Economic Wellbeing eISSN: 2398-4287 © 2023. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v8i23.4467

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