简介:Theconceptof'urbanizationoncityandtownlevel'isanexpressionofChineseversion,oramainlandunderstandingofChina.However,cityandtownareonthedifferentlevels.Inthelightofcensus'measureson'citypopulation'and'townpopulation',thepapertriestoanalyzepopulationsizeanditschangeonboth'city'and'town'levels;tocomparethedifferentpopulationdensityandtheireffect;toobservethemobilepopulationbetween'city'and'town'level,andtheiragestructure.Thepapertriestoexplaintwodemographiceffectsfrom'city'and'town'levelsonthecourseofChineseurbanization.
简介:AbstractBackground:The optimal surgical approach for four-level cervical spondylotic myelopathy remains controversial. The purpose of this study was to compare clinical and radiological outcomes and complications between the anterior and posterior approaches for four-level cervical spondylotic myelopathy.Methods:A total of 19 patients underwent anterior decompression and fusion and 25 patients underwent posterior laminoplasty and instrumentation in this study. Perioperative information, intraoperative blood loss, clinical and radiological outcomes, and complications were recorded. Japanese Orthopedic Association (JOA) score, 36-item short form survey (SF-36) score and cervical alignment were assessed.Results:There were no significant differences in JOA scores between the anterior and posterior group preoperatively (11.6 ± 1.6 vs. 12.1 ± 1.5), immediately postoperatively (14.4 ± 1.1 vs. 13.8 ± 1.3), or at the last follow-up (14.6 ± 1.0 vs. 14.2 ± 1.1) (P > 0.05). The JOA scores significantly improved immediately postoperatively and at the last follow-up in both groups compared with their preoperative values. The recovery rate was significantly higher in the anterior group both immediately postoperatively and at the last follow-up. The SF-36 score was significantly higher in the anterior group at the last follow-up compared with the preoperative value (69.4 vs. 61.7). Imaging revealed that there was no significant difference in the Cobb angle at C2-C7 between the two groups preoperatively (-2.0° ± 7.3° vs. -1.4° ± 7.5°). The Cobb angle significantly improved immediately postoperatively (12.3° ± 4.2° vs. 9.2° ± 3.6°) and at the last follow-up (12.4° ± 3.5° vs. 9.0° ± 2.6°) in both groups compared with their preoperative values (P = 0.00). Three patients had temporary dysphagia in the anterior group and four patients had persistent axial symptoms in the posterior group.Conclusions:Both the anterior and posterior approaches were effective in treating four-level cervical spondylotic myelopathy in terms of neurological clinical outcomes and radiological features. However, the JOA score recovery rate and SF-36 score in the anterior group were significantly higher. Persistent axial pain could be a major concern when undertaking the posterior approach.
简介:Theopticalpropertiesofafive-levelatomicsystemcomposedofaA-typefour-levelatomicandatripodfour-levelatomicsystemsareinvestigated.Itisfoundthatthebehaviorsofelectromagneticallyinducedtransparency(EIT)andgroupvelocitycanbecontrolledbychoosingappropriateparameterswiththeinteractingdarkresonances.Inparticular,whenallthefieldsareonresonance,theslowlightatthesymmetrictransparencywindowswithamuchbroaderEITwidthisobtainedbytuningtheintensityofthecouplingfieldincomparisonwithitssub-system,whichprovidespotentialapplicationsinquantumstorageandretrievaloflight.
简介:这研究试图调查trabecular的地区性的变化,以及决定在trabecular之间的关系词法参数和大腿骨的头的机械参数词法、机械的参数。从有折断的近似腿节的病人的七个大腿骨的头用一个micro-CT系统被扫描。每个大腿骨的头根据trabecular取向被划分成12个分区。一\(125\,\hbox{公里}^{3}\)trabecular立方的模型从每个分区被重建。81个trabecular模型的一个总数被重建,除了从在外科期间的二个大腿骨的头的三个破坏分区。Trabecular词法参数,即trabecular分离(Tb.Sp),trabecular厚度(Tb.Th),特定的骨头表面(BS/BV),骨头体积部分(BV/TV),结构的模型索引(SMI),和anisotropy(DA)的度被测量。微有限的元素分析被执行让每个立方体获得明显的幼仔模量,织物水平von协定在1%下面强调分发沿着三个直角的方向的压缩紧张分别地。结果在词法参数揭示了重要地区性的变化(\(P)。沿着trabecular取向的幼仔moduli比沿着另外的二个方向的那些显著地高。一般来说,trabecular在中间的区域的机械性质是比在侧面的区域的那些低的。沿着trabecular取向的Trabecular机械参数显著地与BS/BV,BV/TV,Tb.Th,和DA被相关。在这研究,在有近似腿节骨折的病人的大腿骨的头的微结构特征和机械性质的地区性的变化彻底地在组织水平被调查。这研究的结果将帮助阐明为减少破裂风险和发展中的治疗策略为的大腿骨的头骨折的机制老。
简介:GroundlevelozonepollutionhasbecomeasignificantairpollutionprobleminBeijing.Becauseofthecomplexwayinwhichozoneisformed,itisdifficultforpolicymakerstoidentifyoptimalcontroloptionsonacost-effectivebasis.Thispaperidenti-fiesandassessesarangeofoptionsforaddressingthisproblem.WeapplytheAmbientLeastCostModelandcomparetheeco-nomiccostsofcontroloptions,thenrecommendthemosteffectivesequencetorealizepollutioncontrolatthelowestcost.ThestudyfindsthatinstallingofStageIIgasolinevaporrecoverysystematBeijing's1446gasolinestationswouldbethemostcost-effectiveoption.Overall,optionstoreduceozonepollutionbycuttingve-hicularemissionsaremuchmorecost-effectivethanoptionsto'cleanup'coal-firedpowerplants.
简介:Thelevelsetmethod,TVDschemeofsecondorderupwindprocedurecoupledwithfluxlimiter,ENOvelocityextensionprocedureinsidethebubble,andMACprojectionalgorithmwereincorporatedtosimulatethewholecollapseevolutionofacavitationbubbleneararigidwallwithmanycomplicatedphenomena,suchastopologydistortionandshrinking,jetimpact,bubblebreakingintoatoroidalform,anddiminishingvolumetozero,etc.Thebubbleshape,evolutionanddistributionofvelocityandpressurefieldsofthefluidduringthebubblecollapsingwereinvestigated.Itisfoundthatthemethodisnumericallystableandhasgoodconvergenceproperty,andtheresultsareingoodagreementswiththoseinpreviouswork.
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简介:AbstractLow-level viremia (LLV) was defined as persistent or intermittent episodes of detectable hepatitis B virus (HBV) DNA (<2000 IU/mL, detection limit of 10 IU/mL) after 48 weeks of antiviral treatment. Effective antiviral therapies for chronic hepatitis B (CHB) patients, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), have been shown to inhibit the replication of HBV DNA and prevent liver-related complications. However, even with long-term antiviral therapy, there are still a number of patients with persistent or intermittent LLV. At present, the research on LLV to address whether adversely affect the clinical outcome is limited, and the follow-up treatment for these patients is open to question. At the same time, the mechanism of LLV is not clear. In this review, we summarize the incidence of LLV, the association between LLV and long-term outcomes, possible mechanisms, and management strategies in these patient populations.
简介:AbstractObjective:To clarify whether the serum squamous cell carcinoma antigen (SCCA) levels of patients with inverted papilloma (IP) are different from patients with nasal polyps (NP) and rhinitis.Materials and methods:Serum SCCA levels were measured in 30 patients with IP and 30 patients with NP at one day before surgery and seven days after surgery and measured in 28 patients with rhinitis.Results:Elevated serum SCCA levels (>1.5 ng/ml) were found in 80.0% of patients in the IP group, 6.7% of patients in the NP group and 14.3% of patients in the rhinitis group, which was a significant difference. The medians of serum SCCA levels in the IP, NP and rhinitis groups were 3.9, 0.8 and 1.1 ng/ml, respectively, which was a significant difference. The SCCA level in IP group was not significantly correlated according to Krouse Staging. There was a significant difference in serum SCCA levels between the pre- and postoperative stages in the IP group, at 3.9 and 0.8 ng/ml, respectively, while in the NP group the levels were 0.8 and 1.0 ng/ml, not significantly different. With regard to the IP diagnosis in the IP and NP group based on the SCCA level (>1.5 ng/ml), sensitivity and specificity was 80.0% and 93.3%, respectively.Conclusions:The serum SCCA level in patients with IP was elevated and then it decreased after surgery. This was different from NP and rhinitis patients who mostly had normal levels, which did not change.
简介:Twouncoupleabledistributions,assigningmissionstorobotsandallocatingrobotstohomestations,accompanytheuseofmobileservicerobotsinhospitals.Inthegivenproblem,twoworkload-relatedobjectivesandfivegroupsofconstraintsareproposed.Abio-mimickedBinaryBeesAlgorithm(BBA)isintroducedtosolvethismultiobjectivemulticonstraintcombinatorialoptimisationproblem,inwhichconstrainthandlingtechnique(MultiobjectiveTransformation,MOT),multiobjectiveevaluationmethod(nondominanceselection),globalsearchstrategy(stochasticsearchinthevariablespace),localsearchstrategy(Hammingneighbourhoodexploitation),andpost-processingmeans(feasibilityselection)arethemainissues.TheBBAisthendemonstratedwithacasestudy,presentingtheexecutionprocessofthealgorithm,andalsoexplainingthechangeofelitenumberinevolutionaryprocess.Itsoptimisationresultprovidesagroupoffeasiblenondominatedtwo-leveldistributionschemes.
简介:Basedonlinearporoelasticandhydrogeologytheory,amathematicalexpressiondescribingtherelationshipbetweenwaterlevelchangeandaquifervolumestrainisputforward.Combinedwithearthtidaltheory,weanalyzetheresponsecharacteristicsfromwell-aquiferwaterlevelchangetoearthtideofvolumestrainandpresentamethodofvolumestraininversionfromwaterlevelchange.Comparingtheresultsofinversionwithrealobserveddata,wefoundthatthereisagoodconsistency.Thissuggeststhatthemethodofvolumestraininversionfromwaterlevelchangeisproper.Itwillofferareferenceforlearningabouthydrogeologycharacteristics,volumestrainandsearchingforprecursoranomalies.
简介:BasedonthesimulationwiththeOcean-AtmosphereCoupledModelCCSMandOceanModelPOPunderthegreenhousegasemissionscenariooftheIPCCSRESA2(IPCC,2001),andontheearthcrustsubsidenceandglaciermeltingdata,therelativesealevelchangeisobtainedalongthecoastofChinainthe21stcentury.UsingtheSRTMelevationdatathesubmergenceofcoastallowlandiscalculatedundertheextremewaterlevelwitha100-yearreturnperiod.Thetotalfloodingareasare98.3×103and104.9×103km2for2050and2080,respectively.Forthethreeregionsmostvulnerabletoextremesealevelrise,i.e.,thecoastofBohaiBay,theYangtzeRiverDeltatogetherwithneighboringJiangsuProvinceandnorthernZhejiangProvince,andthePearlRiverDelta,thefloodedareasare5.0×103,64.1×103and15.3×103km2in2050and5.2×103,67.8×103and17.2×103km2in2080,respectively.