学科分类
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4 个结果
  • 简介:Theparameteridentificationmodelisproposedfordeterminingthelinearadsorptionisothermsandthesoliddiffusioncoefficientsbyusingadsorptionchromatorgaphy.Axialdispersioncoefficientsisfirstlydeterminedbypulse-respondexperimenttechniquewithaninertsubstanceastracer,thentheelutioncurvesofchromatographyseparatingtheisomermannitolandsorbitolaredeterminedbythechromatographicmeasuringtechnique,andpinallytheadsorptionisothermsandthesoliddiffusioncoefficientsofmannitolandsorbitolonCa^2+resinsareestimatedbyusingthismodel.Theresultsshowthattheaxialdispersioncoefficientsincreasewithfluidvelocityincreasing,Theadsorptionequilibriumconstantsdecreasewithtemperaturerising;andthesoliddiffusioncoefficientsincreasewithtemperaturerising.Thetheoreticalelutioncurvesaregoodagreementwiththeexperimentalelutioncurvesoftheliquidadsorptionchromatographyseparatingthemannitolandthesorbitol.Themodelprovidesasimpleandreliableproceduretoestimatethekineticandthermodynamicparmetersoftheadsorption.

  • 标签: 吸附 色谱法 甘露糖醇 山梨醇
  • 简介:AbstractPurpose:Impending compartment syndrome is a common event following closed tibia fractures, which can progress to sinister compartment syndrome. Fasciotomy is the only definitive treatment available, though it has its own drawbacks and complications. Medical management at present consists of limb elevation and adequate hydration. This study aims at determining whether intravenous administration of Mannitol reduced the intracompartmental pressure in patients with closed tibial fractures.Methods:This is a double blinded, randomized control trial done in a single tertiary care center in India. Forty-five patients were recruited between February 2012 and October 2012. Forty patients who presented to the emergency department with isolated, closed, high velocity, and proximal 2/3 tibia fractures were included in this study. Patients with contraindication to Mannitol were excluded. They were allocated into 2 groups by the investigator using computer generated randomization. The pressure in the anterior compartment of the leg was measured with a handheld Stryker pressure monitor. Then either 20% Mannitol or 0.9% normal saline as given intravenously in a blinded manner, based on the randomization. The intracompartmental pressure was measured at 0, 1 and 3 h after the infusion. The participant, investigator and statistician were masked to the group assessment.Results:There was no difference in intracompartmental pressures at 1 or 3 h, between the groups. However, in patients with the baseline of compartmental pressures ≥30 mmHg, Mannitol showed a marked reduction in pressure of 8.5 mmHg at 1 h compared to almost no change in pressure in the saline group. There were no adverse events with the use of Mannitol.Conclusions:This preliminary study appears to show that Mannitol is useful in the management of the increased compartment pressure. The limitations of this study were that it only involved a small group of patients and the baseline pressures in both the groups were not comparable. More studies are required before the use of Mannitol as a standard of care in the management of compartment syndrome can be established.

  • 标签: Mannitol Compartment pressures Acute tibial fractures
  • 简介:AbstractPurpose:Hypertonic fluids such as mannitol and half-molar sodium lactate are given to treat intracranial hypertension in patients with severe traumatic brain injury (TBI). In this study, sodium lactate was compared to mannitol in patients with TBI to investigate the efficacy in reducing intracranial pressure (ICP).Methods:This study was a systematic review with literature research on articles published in any year in the databases of PubMed, ScienceDirect, Asian Journal of Neurosurgery, and Cochrane Central Register of Controlled Trials. The keywords were "half-molar sodium lactate", "mannitol", "cerebral edema or brain swelling", and "severe traumatic brain injury". The inclusion criteria were (1) studies published in English, (2) randomized control trials or retrospective/prospective studies on TBI patients, and (3) therapies including half-molar sodium lactate and mannitol and (4) sufficient data such as mean difference (MD) and risk ratio (RR). Data analysis was conducted using Review Manager 5.3.Results:From 1499 studies, a total of 8 studies were eligible. Mannitol group reduced ICP of 0.65 times (MD 0.65; p= 0.64) and improved cerebral perfusion pressure of 0.61 times (MD 0.61; p= 0.88), better than the half-molar group of sodium lactate. But the half-molar group of sodium lactate maintained the mean arterial pressure level of 0.86 times, better than the mannitol group (MD 0.86; p= 0.09).Conclusion:Half-molar sodium lactate is as effective as mannitol in reducing ICP in the early phase of brain injury, superior over mannitol in an extended period. It is able to prevent intracranial hypertension and give better brain tissue perfusion as well as more stable hemodynamics. Blood osmolarity is a concern as it increases serum sodium.

  • 标签: Half-molar sodium lactate Mannitol Traumatic brain injuries