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114 个结果
  • 简介:1Chemistryandsynthesis1.1ProductionandcontrolofmaterialsThesedaystherecanbefewpeoplewhodonotknowthatproteinsaredefinedbyDNA.DNAismadeoftwostrands,eachofwhichhasalongit,likeastringoffairylights,sidebranchesthatmeetbetweenthestrandsandholdthemtogether.

  • 标签: 生物材料 制造 化学合成 结构
  • 简介:MicroRNAs(miRNAs)areendogenouslyexpressednon-codingRNAsof20-24nucleotides,whichpost-transcriptionallyregulategeneexpressioninplantsandanimals.RecentlyithasbeenrecognizedthatmiRNAscompriseoneoftheabundantgenefamiliesinmulticellularspecies,andtheirregulatoryfunctionsinvariousbiologicalprocessesarewidelyspread.Therehasbeenasurgeintheresearchactivitiesinthisfieldinthepastfewyears.Fromtheverybeginning,computationalmethodshavebeenutilizedasindispensabletools,andmanydiscoverieshavebeenobtainedthroughcombinationofexperimentalandcomputationalapproaches.Inthisreview,bothbiologicalandcomputationalaspectsofmiRNAwillbediscussed.AbriefhistoryofthediscoveryofmiRNAanddiscussionofmicroarrayapplicationsinmiRNAresearcharealsoincluded.

  • 标签: 微型RNA 生物学 计算透视图 核苷 基因表达
  • 简介:Anacousticbasedinstrument,theABSAcousticBubbleSpectrometer??(ABS),wasinvestigatedforthedetectionandquantificationofbubblesinbiologicalmedia.Theseincludeviscoelasticmedia(blood),materialsofvaryingdensity(boneintissue),non-homogenousdistributionofbubbles(intravenousbubblyflow),andbubblesmigratingintissue(decompressionsickness,DCS).TheperformanceoftheABSwasdemonstratedinaseriesoflaboratoryexperiments.Validationofthecodewasperformedusingaviscoelasticpolymersolution,Polyox,inwhichthebubblesizedistributionandvoidfractionweredeterminedbyABSmeasurementsandwithimageanalysisofhighspeedvideos.ThesetestsshowedthattheaccuracyoftheABSwasnotsignificantlyaffectedbyviscoelasticityforbubblessmallerthan200microns.TheABSdetectionandmeasurementofnon-homogenousbubbledistributionswasdemonstratedusingabubblyflowthroughasimulatedveinsurroundedbytissue.Thescatterofacousticsignalsduetobonesintheacousticpathwaywasalsoinvestigated.Thesein-vitroexperimentsweredoneusingmeat(beef)asatissuesimulant.Decompressionexperimentsweredoneusingbeefmeatwhichwasheldunderwaterathighpressure(9.9atm)thenrapidlydecompressed.Bubblesizedistributionsandvoidfractioncalculationsintheseexperimentswerethenvalidatedusingimageanalysisofhighspeedvideo.Inaddition,preliminaryexperimentswereperformedwiththeUSNavyMedicalResearchCenter,demonstratingtheutilityofthemodifiedABSsystemindetectingtheevolutionofbubblesinswineundergoingdecompressionsickness(DCS).TheseresultsindicatethattheABSmaybeusedtodetectandquantifytheevolutionofbubblesin-vivoandaidinthemonitoringofDCS.

  • 标签: 声学测量 泡沫 生物 气泡尺寸分布 ABS树脂 粘弹性介质
  • 简介:Anopen-endedcoaxiallinereflectionmethodespeciallysuitableformeas-uringthedielectricpropertiesofbiologicaltissueinvivoisdescribed.Thismethodofferstheadvantageofnotrequiringanyspecialpreparationofthesamplestobemeasuredbutaclosecontactwiththeopenendofacoaxialline.Itis,therefore,veryconvenienttoacquirealargenumberofmeasurementdatainbroadbandrapidly.Themethodmayalsobeusedtomeasurethepropertiesofothersubstances.ThemeasuringsystemconsistsofanetworkanalyzercontrolledbyamicrocomputerandcalibratedbyusingANAproceduretoelimi-hatetheinflunceoferrornetworkintroducedbytheadapter,someconnectors,etc.Inor-dertoreachhigheraccuracy,theiterativemethodisusedtodeterminetheparametersoftheequivalentcircuit.Measurementsofpermeativitiesofsomelivingtissueshavebeenper-formedinthefrequencybandof0.5-2GHz.Comparedwiththeresultsknowninsomepapers,thevalidityofthismethodhasbeenconfirmed.Thedifferenceindielectricproper-tiesbetweenlivinganddeadtissues,andthetissuepermeativites(ε)versusfrequencyanddurationofmeasurementafterdeathhavealsobeenmeasured.

  • 标签: DIELECTRIC property/biological TISSUE open-ended COAXIAL line
  • 简介:Thispaperdiscussesproblemsinbio-pulping,putsforwardtheresolutiontotheseproblems,andpointsouttheadvantagesofbio-pulpingandfuturedevelopmentpotential.

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  • 简介:Intheindustrializedcountriesthemaingoalatthenationalhealthcarepolicymakinglevelistocontaincostswithoutcompromizingthetwogoalsofhealthcare:accessandquality.Atthesametimemedicineisevolvingthroughinevntions,inno-vationsandimprovements.Technologieswhichcanbeusedtoprolonglifebutwhicharenotcurativehavealsoimprovedandbecomewidelyused.Withtheageingpopu-lationsoftheindustrializedcountriescontainingcostsisgettingextremelydifficult.

  • 标签: EXTREMELY CURATIVE prolong GETTING goals ageing
  • 简介:Biologicalelementsusuallyexerttheirfunctionsthroughinteractionswithotherstoformvarioustypesofbiologicalnetworks.Theabilityofcontrollingthedynamicsofbiologicalnetworksisofenormousbenefitstopharmaceuticalandmedicalindustryaswellasscientificresearch.Thoughtherearemanymathematicalmethodsforsteeringdynamicsystemstowardsdesiredstates,themethodsareusuallynotfeasibleforapplyingtocomplexbiologicalnetworks.Thedifficultiescomefromthelackofaccuratemodelthatcancapturethedynamicsofinteractionsbetweenbiologicalelementsandthefactthatmanymathematicalmethodsarecomputationallyintractableforlarge-scalenetworks.Recently,aconceptincontroltheory--controllability,hasbeenappliedtoinvestigatethedynamicsofcomplexnetworks.Inthisarticle,recentadvancesonthecontrollabilityofcomplexnetworksandapplicationstobiologicalnetworksarereviewed.Developingdynamicmodelsisthepriorconcernforanalyzingdynamicsofbiologicalnetworks.First,weintroduceawidelyuseddynamicmodelforinvestigatingcontrollabilityofcomplexnetworks.Thenrecentstudiesoftheoremsandalgorithmsforhavingcomplexbiologicalnetworkscontrollableingeneralorspecificapplicationscenariosarereviewed.Finally,applicationstorealbiologicalnetworksmanifestthatinvestigatingthecontrollabilityofbiologicalnetworkscanshedlightsonmanycriticalphysiologicalormedicalproblems,suchasrevealingbiologicalmechanismsandidentifyingdrugtargets,fromasystematicperspective.

  • 标签: BIOLOGICAL NETWORK NETWORK CONTROLLABILITY STEERING NODE
  • 简介:SurveyonbiologicalfoulingandcorrosionofvesselsINTRODUCTIONSincethesteelshellvesselscameintobeing,biologicalfoulingandcorrosio...

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  • 简介:Thequantumvibrationalenergy-spectraincludinghighexcitedstatesoftheproteinmoleculeshavebeencalculatedbynewtheoryofbio-energytransportalongtheproteinmoleculesanditsdynamicequation,discretenonlinearSchrodingerequation,appropriatetotheproteinmoleculesonthebasisofthelevelofmolecularstructure.Thisenergy-spectraobtainedarebasicallyconsistentwiththeexperimentalvaluesbyinfraredabsorptionandradiatedmeasurementofperson'shandsandlaser-RamanspectrumfrommetabolicallyactiveE.Coli..Fromthisenergy-spectraweknowthattheinfraredlightswith(1-3)x1000nmand(5-7)x1000nmwavelengthcanbeabsorbedbytheproteinmoleculesinthelivingsystems.Inaccordancewiththenon-lineartheoryofthebio-energytransportweknowthattheenergyoftheinfraredlightabsorbedbytheproteinscanresultinvibrationsofamide-Iinaminoacidsandcanfacilitatethebio-energytransportalongtheproteinmolecularchainsfromoneplacetootherforthegrowthoflivingbodies.Thisprocesseisnon-thermal.Thisisjustnon-thermaleffectoftheinfraredlights.Accordingtothemechanismweexplainedfurtherthemedicalfunctionsoftheinfraredlightsabsorbed.

  • 标签: INFRARED light BIO-ENERGY transport energy-spectra NON-THERMAL
  • 简介:BasedontheFenlon‘stheorytheparametriceffectsinfluidsduetothenonlinearinteractionofalowfrequencypumpingwaveandahighfrequencyprobingwaveareanalysed.TheexpressionsofpressureamplitudeofsumordifferencefrequencysidebandandthefromulaofnonlinearityparameterB/Aforlossymediumarederived.Theoreticalcalculationdemonstrated,thatthesidebandcomponentsincreaselinearlywithpumpsignal.Therefore,amethodfordeterminationofB/Aisprovidedandtheval-uesforseveralbiologicalfluidsandmixturesaremeasured.

  • 标签: PUMPING LINEARLY NONLINEARITY PROBING analysed PARAMETRIC
  • 简介:Thisworkbrieflysummarizedtherecentresearcheffortsmadeonthephaseheattransferprocessesinvolvingbiologicalaggregates,withparticularattentiononthecorrelationofaggregatestructureandstateofwaterwiththeprocessefficiency.Thephasechangeprocessesincludeboiling,drying,freezing,sintering,pyrolysis,andsupercriticalextraction,whiletheformerthreewerediscussedinsomedetail.

  • 标签: PHASE-CHANGE AGGREGATES FRACTAL STRUCTURES BOUND water.
  • 简介:Thefieldofmechanicsofbiologicalandbio-inspiredmaterialsunderwentanexcitingdevelopmentoverthepastseveralyears,whichmadeitstandatthecuttingedgeofbothengineeringmechanicsandbiomechanics.Asanintriguinginterdisciplinaryresearchfield,itaimsatelucidatingthefundamentalprinciplesinnature'sdesignofstrong,multi-functionalandsmartMaterialsbyfocusingontheassembly,deformation,stabilityandfailureofthematerials.Theseprinciplesshouldhavewideapplicationsinnotonlymaterialsciencesandmechanicalengineeringbutalsobiomedicalengineering.Forinstance,theknowledgeinMechanicalprinciplesofbiologicalmaterialsisveryhelpfulforaddressingsomemajorchallengesinmaterialsciencesandengineering.Theyalsohavethepotentialtoprovidequantitativeunderstandingabouthowforcesanddeformationaffecthumanbeing'shealth,diseasesandtreatmentattissue,cellularandmolecularlevels.

  • 标签: 材料力学 生物力学 仿生 编辑 工程力学 智能材料
  • 简介:AbstractThe time of birth is a critical determinant of perinatal and long-term outcomes, and even trans-generational effects. Preterm birth is still the leading cause of infant mortality and morbidity. Unfortunately, rates of preterm birth remain high worldwide. Preterm parturition is a complex syndrome, which can be induced by several factors such as infection, cervical pathology, uterine overdistension, progesterone deficiency, vascular alterations (utero-placental ischemia, decidual hemorrhage), maternal and fetal stress, allograft reaction, allergic phenomena, and probably other several unknown factors. The mechanisms responsible for early labor activation have been partially identified and involve receptors, chemokines, and inflammatory cytokines. It is very useful to understand the cellular and biochemical pathways responsible for preterm labor activation to identify, treat, and prevent negative outcome in a timely manner. Researchers and clinicians play a key role in improving biochemical knowledge on preterm delivery, identifying risk factors, and applying multilevel preventive strategies.

  • 标签: Premature birth Biological pathways Inflammation Prevention strategies
  • 简介:Onthebasisofthequantizationofmesoscopicbiologicalcellequivalentcircuit,westudiedthequantumfluctuationsofvoltageandcurrentofmesoscopicbiologicalcellequivalentcircuitasfinitetemperaturebyBogoliuovtransformation.Theresultshowsthatthequantumfluctuationsofvoltageandcurrentnotonlyrelatewiththeparametersofequivalentcircuit,temperature,butalsodecaywithtime.Thisresultmayhavesignificantvalueonthedesignandapplicationofthebio-electronicapparatus.

  • 标签: 量子波动 生物细胞 生物电子 DNA 温度环境