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Finite-Size Conformational Transitions: A Unifying Concept Underlying Chromosome Dynamics

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Communications in Theoretical Physics 2014年第10期61卷 607-616页

作者： Bertrand r.caré Pascal carrivain Thierry Forné Jean-Marc Victor Annick Lesne Laboratoire de Physique Théorique de la Matière Condensée CNRS UMR 7600UPMC University Paris 06F-75005ParisFrance CNrS GDr 3536 UPMC University Paris 06F-75005ParisFrance Institut de Génétique Humaine CNRS UPR 1142 MontpellierFrance Institut de Génétique Moléculaire de Montpellier CNRS UMR 5535University of MontpellierMontpellierFrance Kavli Institute for Theoretical Physics China CAS

Investigating average thermodynamic quantities is not sufficient to understand conformational transitions of a finite-size polymer. We propose that such transitions are better described in terms of the probability distribution of some finite-size order parameter, and the evolution of this distribution as a control parameter varies. We demonstrate this claim for the coil-globule transition of a linear polymer and its mapping onto a two-state model. In a biological context, polymer models delineate the physical constraints experienced by the genome at different levels of organization,from DNA to chromatin to chromosome. We apply our finite-size approach to the formation of plectonemes in a DNA segment submitted to an applied torque and the ensuing helix-coil transition that can be numerically observed, with a coexistence of the helix and coil states in a range of parameters. Polymer models are also essential to analyze recent in vivo experiments providing the frequency of pairwise contacts between genomic loci. The probability distribution of these contacts yields quantitative information on the conformational fluctuations of chromosome regions. The changes observed in the shape of the distribution when the cell type or the physiological conditions vary may reveal an epigenetic modulation of the conformational constraints experienced by the chromosomes.

关键词： coil-globule transition helix-coil transition chromosome conformational capture two-state model

Inter-population variabilities in seed mass and germination of Panicum turgidum and Pennisetum divisum in the desert of Kuwait

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Journal of Arid Land 2020年第1期12卷 144-153页

作者： Arvind BHATT Narayana r BHAT Afaf AL-NASSEr María M carÓN AndreaSANTO Kuwait Institute for Scientific research Safat 24885Kuwait Laboratory of Botanical research(LABIBO) Faculty of Natural SciencesNational University of Salta-CONICETSalta 4400Argentina Independent researcher Selargius 09047Italy

Understanding variability in seed germination among populations is essential for planning an effective germplasm collection for restoration and conservation *** knowledge of germination and dormancy patterns among populations of desert grasses is crucial for determining the potential of the species and populations to be used for restoration and conservation as well as forage *** in seed germination of Panicum turgidum Forssk and Pennisetum divisum(Gmel.)*** the desert of Kuwait was evaluated in different populations in May *** of seed germination(25 seeds and 4 replicates)was conducted for each population at night/day temperatures of 15℃/20℃and 20℃/30℃under the following light condition:continuous darkness or 12 h/12 h light/*** showed that seed masses of both species strongly varied according to their seed provenances,and both species produced heavier seeds in population with a higher soil electrical *** germination percentage considerably varied between two species,and the variation in *** was greater(17%–49%)than that of ***(72%–93%).Germination percentage in *** was greater at high temperature(20℃/30℃)than at low temperature(15℃/20℃).However,temperature regimes had no effect on germination percentage of *** *** germination time of both species exhibited significant inter-population *** result is especially relevant to assure the selection of the best population of each species and the regeneration success of the *** this,inter-population variability also provides valuable information for enhancing our understanding of the mechanisms that regulate seed germination and how they might be related to seed provenance.

关键词： desert grass seed germination inter-population variability seed provenance seed dormancy

Stability analysis of slopes with planar failure using variational calculus and numerical methods

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Frontiers of Structural and Civil Engineering 2020年第5期14卷 1262-1273页

作者： Norly BELANDrIA robertoÚcar Francisco M.LEON Ferri HASSANI Geological Engineering School University of Los AndesMérida 5101Venezuela Mechanical Engineering School University of Los AndesMérida 5101Venezuela Department of Mining and Material Engineering McGill UniversityMontrealQC H3A 0E9Canada

This study investigates the technique of variational calculus applied to estimate the slope stability considering the mechanism of planar *** critical plane failure surface should be determined because it theoretically indicates the most unfavorable plane to be considered when stabilizing a slope to rectify the instability generated by several statistically possible *** generates integrals that can be solved by numerical methods,such as the Newton Cotes and the finite differences ***,a system of nonlinear equations is obtained and *** surface of the critical planar failure is determined by applying the condition of transversality in mobile boundaries,for which various examples are *** number of slices is varied in one of the examples,while the surface of the critical planar failure is determined in the *** are compared using analytical methods through axis *** the results obtained by considering normal stress,safety factors,and critical planar failure are nearly the same;however,in this research,a study is carried out for“n”number of slices using programming ***-routines are important because they can be applied in slopes with different geometry,surcharge,interstitial pressure,and pseudo-static load.

关键词： slopes stability planar failure variational calculus numerical methods

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基于大语言模型的糖尿病管理:潜力与展望

Science Bulletin 2024年第5期69卷 583-588页

作者：盛斌管洲榆 Lee-Ling Lim 江泽铧 Nestoras Mathioudakis 李佳佳刘茹涵包玉倩 Yong Mong Bee 王亚星郑颖丰 Gavin Siew Wei Tan 纪宏伟 Josip car 王海波 David C.Klonoff 李华婷覃宇宗黄天荫贾伟平 Shanghai International Joint Laboratory of Intelligent Prevention and Treatment for Metabolic Diseases Department of Computer Science and EngineeringSchool of ElectronicInformationand Electrical EngineeringShanghai Jiao Tong UniversityDepartment of Endocrinology and MetabolismShanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai Diabetes InstituteShanghai Clinical Center for DiabetesShanghai 200240China MOE Key Laboratory of Artificial Intelligence Artificial Intelligence InstituteShanghai Jiao Tong UniversityShanghai 200240China Department of Medicine Faculty of MedicineUniversity of MalayaKuala Lumpur 50603Malaysia Department of Medicine and Therapeutics The Chinese University of Hong KongHong KongChina Asia Diabetes Foundation Hong KongChina Tsinghua Medicine of Tsinghua University Beijing 100084China School of Clinical Medicine Beijing Tsinghua Changgung HospitalBeijing 102218China Division of Endocrinology Diabetes&MetabolismJohns Hopkins University School of MedicineBaltimoreMD 21211USA Department of Endocrinology Singapore General HospitalSingapore 169608Singapore Beijing Institute of Ophthalmology Beijing Tongren HospitalCapital University of Medical ScienceBeijing Ophthalmology and Visual Sciences Key LaboratoryBeijing 100730China State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhou 510060China Singapore Eye research Institute Singapore National Eye CentreSingapore 168751Singapore Department of cardiology the Affiliated Hospital of Qingdao UniversityQingdao 266011China Centre for Population Health Sciences Lee Kong Chian School of MedicineNanyang Technological University SingaporeSingapore 639798Singapore Department of Primary care and Public Health School of Public HealthImperial College LondonLondon SW72BUUK Clinical Trial Unit Research Centre of Big Data and Artificial Intelligence in Medicine

The increasing prevalence of diabetes has become a global public health concern in the 21st *** 2021,it was estimated that 537 million people had diabetes,and this number is projected to reach 643 million by 2030,and 783 million by 2045[1].Such a huge burden of diabetes brings great challenges in its prevention and management,including early diagnosis,timely interventions,and regular monitoring of risk factor control and complications *** self-care support and patient empowerment can enhance clinical and psychobehavioural outcomes[2],although these require additional resources including manpower,infrastructure(hard and technology),and *** emergence of digital health technologies(DHTs),especially artificial intelligence(AI),may help address these obstacles and alleviate the burden of diabetes[3].Large language models(LLMs),a generative AI that can accept image and text inputs and produce text outputs,have shown promise in various aspects of medical care.

关键词： prevention diagnosis finance

Determination of thyreostats in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry

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色谱 2017年第10期35卷 1048-1054页

作者： Lech rODZIEWICZ Jolanta MASLOWIECKA Anna SADOWSKA Halina car Laboratory of Chemical Examination of Foodstuffs Department of Veterinary Hygiene Department of Experimental Pharmacology Medical University of Bialystok

Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization *** and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization *** was achieved on an Acquity UPLC SS T3 *** mobile phase was acetonitrile and water containing 0.2%(v/v)formic *** mass spectrometer was operated in multiple reaction monitoring *** samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/*** accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,rSD)less than 15%for all five *** rSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,*** CCαand CCβvalues were below the recommended concentration,which was set at 10μg/*** results show that the described method is suitable for the direct detection of TSs in bovine *** method can also be used to determine TSs in porcine urine.

关键词： ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) thyreostats (TSs) urine

Thermodynamic Analysis of a Condensate Heating System from a Marine Steam Propulsion Plant with Steam reheating

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Journal of Marine Science and Application 2021年第1期20卷 117-127页

作者： Vedran Mrzljak Ivan Lorencin Nikola Anđelić Zlatan car Faculty of Engineering University of RijekaVukovarska 5851000 RijekaCroatia

The thermodynamic(energy and exergy)analysis of a condensate heating system,its segments,and components from a marine steam propulsion plant with steam reheating is performed in this *** is found that energy analysis of any condensate heating system should be avoided because it is highly influenced by the measuring equipment accuracy and *** the components from the observed marine condensate heating system have energy destructions lower than 3 kW,while the energy efficiencies of this system are higher than 99%.The exergy efficiency of closed condensate heaters continuously increases from the lowest to the highest steam pressures(from 70.10%to 92.29%).The ambient temperature variation between 5℃and 45℃notably influences the exergy efficiency change of both low pressure heaters and the low pressure segment equal to 31.61%,12.37%,and 18.35%,respectively.

关键词： Condensate heating system Marine steam propulsion plant Steam reheating Thermodynamic analysis Energy and exergy analyses Segmental analysis Ambient temperature change

Designing a Scar molecular marker for monitoring Trichoderma cf. harzianum in experimental communities

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2014年第11期15卷 966-978页

作者： Gabriel PérEZ Valentina VErDEJO Clarissa GONDIM-POrTO Julieta OrLANDO Margarita carú Department of Ecological Sciences Faculty of SciencesUniversity of Chile

Several species of the fungal genus Trichoderma establish biological interactions with various micro- and macro-organisms. some of these interactions are relevant in ecological terms and in biotechnological applications, such as biocontrol, where Trichoderma could be considered as an invasive species that colonizes a recipient community. The success of this invasion depends on multiple factors, which can be assayed using experimental communities as study models. Therefore, the aim of this work is to develop a species-specific sequence-characterized amplified region （Scar） marker to monitor the colonization and growth of T. cf. harzianum when it invades experi- mental communities. For this study, 16 randomly amplified polymorphic DNA （rAPD） primers of 10-mer were used to generate polymorphic patterns, one of which generated a band present only in strains of T. cf. harzianum. This band was cloned, sequenced, and five primers of 20-23 mer were designed. Primer pairs 2F2/2r2 and 2F2/2r3 successfully and specifically amplified fragments of 278 and 448 bp from the T. cf. harzianum BpT10a strain DNA, respectively. Both primer pairs were also tested against the DNA from 14 strains of T. cf. harzianum and several strains of different fungal genera as specificity controls. Only the DNA from the strains of T. cf. hat-zianum was successfully amplified. Moreover, primer pair 2F2/2r2 was assessed by quantitative real-time polymerase chain reaction （PCr） using fungal DNA mixtures and DNA extracted from fungal experimental communities as templates. T. cf. harzianum was detectable even when as few as 100 copies of the Scar marker were available or even when its population represented only 0.1% of the whole community.

关键词： Tnchoderma cf. harzianum Sequence-characterized amplified region (Scar) Molecular marker Experimental fungal communities

Coupling textural and stable-isotope variations in fluvial stromatolites:Comparison of Pleistocene and recent records in NE Spain

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Journal of Palaeogeography 2019年第2期8卷 150-169页

作者： C.Arenas M.C.Osácar L.Auqué C.Sancho Department of Earth Sciences University of Zaragoza Geotransfer Group and Institute for research on Environmental Sciences of Aragón(IUCA)

Textural and stable isotopic features of two middle Pleistocene fluvial stromatolite profiles are compared to a recent stromatolite,both formed in the river Piedra system(NE Spain),to test the reliability of climatic,hydrologic and depositional information derived from ancient *** Pleistocene stromatolites formed in a multi-domed,highly-inclined *** recent stromatolite also formed in a highly-inclined cascade of the river Piedra,the sedimentary conditions of which were periodically examined between the years 2000 and *** Pleistocene stromatolites are formed of an alternation of 1) thin large-crystal laminae(type A),with elongated crystals up to 1 mm long,and 2) thick small-crystal laminae(type B),consisting of cyanobacterial fan-and bushshaped *** textural and isotopic comparison with the recent stromatolite shows that each A–B couplet corresponds to one *** type-A laminae are comparable to the macrocrystalline laminae that occur in the cool-period deposits of the recent stromatolite,and the type-B laminae are comparable to the warm-period deposits of the recent *** temperatures(Tw),calculated from δ^(18)O_(calcite) and present measures of δ^(18)O_(water),were similar in the Pleistocene and recent specimens,and close to the measured river ***,the Pleistocene stromatolites formed not far from isotopic equilibrium,as did the recent *** Pleistocene δ^(18) O_(calcite) biannual oscillation is wider in amplitude than in the recent stromatolite,which suggests larger differences in Tw through the year in the Pleistocene than at *** Pleistocene δ^(13)C_(calcite) does not show any pattern;and the values are slightly higher than the recent *** co-evolution of δ^(18)O and δ^(13)C is parallel in the Pleistocene stromatolites,matching the recent stromatolite *** results and their comparison with other ancient examples prove that textural and isotopic features in ancient stromatolites

关键词： Tufa recent and ancient stromatolites Stable isotopes Biotic and abiotic laminae Intra-annual and inter-annual water temperature variations

Foregut duplication cysts of the stomach with respiratory epithelium

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World Journal of Gastroenterology 2007年第8期13卷 1279-1281页

作者： Theodosios Theodosopoulos Athanasios Marinis Konstantinos Karapanos Georgios Vassilikostas Nikolaos Dafnios Lazaros Samanides Εleni carνounis 2nd Department of Surgery Areteion University Hospital 76 Vasilisis Sofias av. Athens 11528 Greece Department of Pathology Areteion University Hospital 76 Vasilisis Sofias av. Athens 11528 Greece

Gastrointestinal duplication is a congenital rare disease entity. Gastric duplication cysts seem to appear even more rarely. Herein, two duplications cysts of the stomach in a 46 year-old female patient are presented. Abdominal computed tomography demonstrated a cystic lesion attached to the posterior aspect of the gastric fundus, while upper gastrointestinal endoscopy was negative. An exploratory laparotomy revealed a non-communicating cyst and a smaller similar cyst embedded in the gastrosplenic ligament. Excision of both cysts along with the spleen was performed and pathology reported two smooth muscle coated cysts with a pseudostratified ciliated epithelial lining (respiratory type).

关键词： Gastric Cyst Foregut Duplication respiratory