Sequential Column Research Articles

Dynamic modeling and modification of ternary semicontinuous distillation without a middle vessel for improved controllability and energy performance

Ternary distillation conventionally requires two sequential columns. In a process intensification technique, the second column is eliminated by operating the first column in a cyclic manner, where the intermediate component is withdrawn periodically from a side stream. This process, called semicontinuous distillation (SCD) without a middle vessel, can lower the separation costs significantly. However, it exhibits controllability challenges due to the periodic recycling of the side stream. In this work, the process controllability is improved by adding a surge tank in the side stream recycle path. The modification increases significantly the process robustness without changing the operation recipe. Also, the modified SCD can lower maintenance costs as the manipulated variables experience milder oscillations. Moreover, it is shown to have a faster startup than the original design, yielding about 13 % energy saving per feed processed and processing about 25 % more feed during the startup compared with the original design. The case studies show the surge tank volume should be chosen based on the trade-off between attenuation of undesired disturbances and slow-down of desired control actions. Also presented in this article is detailed hybrid discrete-continuous dynamic modeling of the SCD and how the resulting model is implemented in the open-source software OpenModelica.

Comparative Studies of Diclofenac Sodium (NSAID) Adsorption on Wheat (Triticum aestivum) Bran and Groundnut (Arachis hypogaea) Shell Powder using Vertical and Sequential Bed Column

Wheat bran and groundnut shell powder have been used to study the mechanism of diclofenac sodium adsorption from aqueous solution using batch as well as column modes and maximum uptake is 84.3% for wheat bran and 82.4% for groundnut shell powder at pH 6, drug concentration 1 mg/L at 298 K for 30min. Isotherm and error analysis reveals that Freundlich and Langmuir isotherms fitted well. Kinetic studies show that the adsorption process follows second-order kinetics and thermodynamic study shows endothermic adsorption process. Column adsorption study is important for industrial scale adsorption and column studies have been carried out using vertical bed and sequential bed adsorption columns at pH 6 which is the optimum pH for maximum adsorption for batch experiments. Vertical and sequential bed columns setup is simple and economical which provides flow under gravity. The effect of varying inlet feed concentration and flow rate on the breakthrough and exhaustion time of columns has been studied to determine the bed capacities of both columns. Thomas model and Yoon-Nelson models fitted well with experimental data for continuous flow column studies.

Continuous flow column adsorption and desorption for the study of interaction of fluoroquinolone antibiotic ofloxacin hydrochloride with ZnO and CuO nanometal oxides in aqueous solution: (Continuous column adsorption desorption)

Broad-spectrum antibiotic, major veterinary medicines, due to large consumption and inappropriate disposal contribute a major part in generation of pharmaceutical pollutants in aquatic environment. The study investigates the interaction of nanometal oxides for adsorption and desorption of Fluoroquinolone antibiotic, ofloxacin hydrochloride from aqueous solution using vertical and sequential bed adsorption columns: designing parameters of adsorption column determined using bed depth service time model. To optimize the continuous flow column adsorption, varying initial drug concentration and flow rates have been studied using ZnO and CuO nanoparticles at pH 4, already determined for optimized batch studies. To access the characteristic behaviour of breakthrough curves, Thomas model and Yoon-Nelson models have been studied, which were in good agreement with experimental data. Sequential bed column shows slightly better results than vertical bed column as the sequential bed is simple and economical, the solution flows in continuous manner under gravity without any mechanical devices and come into contact with fresh adsorbent bed having same amount as that in vertical bed. Therefore sequential bed column can consider in small scale industries for pharmaceutical wastewater treatment. Column desorption experiments have also been carried out by using HCl/NaOH as desorbing agent for the regeneration of drug loaded adsorbent column.

Repetition blindness in a saccadic persistence of vision display.

A form of repetition blindness in visually unimpaired individuals was found for objects presented during saccades. Observers were asked to draw their percepts after making saccades across an LED strip that "painted" an image on their retinas by presenting sequential columns of a bitmap at a speed to match a 30-degree saccade. During experimental trials, repetitions of a single letter (either "A," "X," "H," or "V") were presented across saccades. Although an average of six letters were presented across each saccade, observers typically indicated perceiving only a single instance of the letter in their drawings. This inability to perceive multiple instances of a letter was not due to a limited region of attentional processing, as it only attained for multiple instances along the axis of the saccade-horizontal saccades did not affect perception of multiple letters along the vertical axis. This effect is likely due to selective suppression of visual areas during saccades.

Cytotoxic Effects of Ardisiacrispin A from Labisia pumila on A549 Human Lung Cancer Cells.

Lung cancer is the predominant cause of cancer-related fatalities. This prompted our exploration into the anti-lung cancer efficacy of Labisia pumila, a species meticulously selected from the preliminary screening of 600 plants. Through the strategic implementation of activity-guided fractionation, ardisiacrispin A (1) was isolated utilizing sequential column chromatography. Structural characterization was achieved employing various spectroscopic methods, including nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared spectroscopy (IR). L. pumila 70% EtOH extract showed significant toxicity in A549 lung cancer cells, with an IC50 value of 57.04 ± 10.28 µg/mL, as well as decreased expression of oncogenes and induced apoptosis. Compound 1, ardisiacrispin A, induced a 50% cell death response in A549 cells at a concentration of 11.94 ± 1.14 µg/mL. The present study successfully investigated ardisiacrispin A extracted from L. pumila leaves, employing a comprehensive spectroscopic approach encompassing NMR, IR, and MS analyses. The anti-lung cancer efficacy of ardisiacrispin A and L. pumila extract was successfully demonstrated for the first time, to the best of our knowledge.

Separation and purification of nylon 54 salts from fermentation broth by an integrated process involving microfiltration, ultrafiltration, and ion exchange.

Nylon 54 is a novel, biodegradable polyamide with excellent thermal resistance and water absorption properties. It can be polymerized using bio-based cadaverine and succinic acid as monomers. Traditional separation methods isolate individual monomers from the fermentation broth through acidification or alkalization, resulting in significant amounts of waste salts; however, synchronous separation of dibasic acids and diamines has not been reported. This study investigated an integrated process for the separation and extraction of nylon 54 salts from a co-fermentation broth without acidification or alkalization. We meticulously optimized the operational parameters of the integrated process to achieve maximum separation efficiency. Following microfiltration, ultrafiltration, and decolorization, the bacterial eliminating rate was ≥99.83%, and the protein concentration was ≤40mg/L. The absorbance of the decolorized solution was ≤0.021 at 430nm, and the recovery rate of nylon 54 salt reached 97%. Then, the pretreated solution was passed through sequential chromatographic columns, which effectively removed organic acid by-products (such as acetic acid and lactic acid), SO4 2-, and NH4 + from the fermentation broth, resulting in a cadaverine yield of 98.01% and a succinic acid yield of 89.35%. Finally, by concentrating and crystallizing the eluent, the simulated fermentation broth yielded nylon 54 salt with a purity of 99.16% and a recovery rate of 58%, and the real fermentation broth yielded nylon 54 salt with a purity of 98.10% and a recovery rate of 56.21%. This integrated process offers a sustainable and environmentally friendly pathway for the complete biosynthesis of nylon 54 salt and has the potential to be extended to the preparation of other nylon salts.

Preparative separation of iridoid glucosides and crocins from Gardeniae Fructus using sequential macroporous resin column chromatography and evaluation of their anti-inflammatory and antioxidant activities

Iridoid glycosides (geniposide (GP), genipin-1-gentiobioside (GB), etc.) and crocins (crocin Ⅰ (CR1), crocin Ⅱ(CR2), etc.) are two main bioactive components in Gardeniae Fructus (GF), which is a famous traditional Chinese medicine. Iridoid glycosides exhibit many activities and are used to manufacture gardenia blue pigment for the food industry. Crocins are rare natural water-soluble carotenoids that are often used as food colorants. A sequential macroporous resin column chromatography technology composed of HC-500B and HC-900B resins was developed to selectively separate iridoid glucosides and crocins from GF. The adsorption of GP on HC-900B resin was an exothermic process. The adsorption of CR1 on HC-500B resin was an endothermic process. The two kinds of components were completely separated by a sequential resin column. GB and GP were mainly found in product 1 (P1) with purities of 11.38% and 46.83%, respectively, while CR1 and CR2 were mainly found in product 2 (P2) with purities of 12.32% and 1.40%, respectively. The recovery yields of all the compounds were more than 80%. The above results showed that sequential resin column chromatography technology achieved high selectivity and recovery yields. GF extract, P1 and P2 could significantly inhibit the secretion of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-induced RAW264.7 cells, indicating that iridoid glycosides and crocins provide a greater contribution to the anti-inflammatory activity of GF. At the same time, compared to the GF extract and P1, P2 exhibited stronger scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, indicating that crocins may provide a significant contribution to the antioxidant activity of GF.

Maximal performance of intact N-glycopeptide enrichment using sequential HILIC and MAX columns.

Low abundance and heterogeneity of N-glycosylation at the peptide level poses a great challenge to the structural and functional analysis of glycosylation in the field of glycobiology. Solving this conundrum requires a sufficient and specific method for intact N-glycopeptide enrichment. Using the C18 or HLB desalting column followed by the mixed-mode strong anion exchange (MAX) or hydrophilic interaction chromatography (HILIC) glycopeptide enrichment column are commonly applied approaches for sample preparation of intact N-glycopeptides from complex samples. Herein, we compared the effects of different combinations of two desalting columns and two enrichment columns using equal amounts of mouse brain tissues from the same source. The results revealed the C18 column was a bit superior to the HLB column, and the MAX and HILIC columns were complementary on intact N-glycopeptides enrichment. Additionally, the results also demonstrated that enriching glycopeptides using a HILIC column followed by a MAX column from the flow-through solution got a better enrichment performance than the reversed order. Based on these results, the sequential enrichment of glycopeptides using HILIC and then MAX columns could maximize the enrichment performance of intact N-glycopeptides, and therefore is an option for in-depth analysis of site-specific glycoproteome.

Rapid and Simultaneous Determination of 238Pu, 239Pu, 240Pu, and 241Pu in Samples with High-Level Uranium Using ICP-MS/MS and Extraction Chromatography.

As the most important plutonium isotopes, 238Pu, 239Pu, 240Pu, and 241Pu are normally measured by two to three techniques, which are tedious, time-consuming, and not suitable for rapid analysis in emergency situations. Recently, ICP-MS has become a competitive technique for the rapid measurement of 239Pu, 240Pu, and 241Pu. However, ICP-MS is difficult to measure 238Pu due to the serious isobaric interference of 238U. This work reports a rapid analytical method to solve this problem for the simultaneous determination of 238Pu, 239Pu, 240Pu, and 241Pu using triple-quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) combined with chemical separation. Chemical separation achieved a high decontamination factor of 2.12 × 109 for the most critical interfering element, uranium, by using two sequential TK200 columns. The interferences of 238U1H+ and 238U+ were effectively eliminated by using 12 mL/min He-6 mL/min NH3 as the reaction gases in the octupole collision/reaction cell in ICP-MS/MS. Combined with chemical separation, the overall elimination efficiency of 238U1H+ reached 3.6 × 1017, which is 105 times better than the reported method. With the high 238U+ elimination efficiency of 1.12 × 104 in the ICP-MS/MS measurement, the overall removal efficiency of 238U+ reached 1013, guaranteeing accurate determination of femtogram-level 238Pu as well as 239Pu, 240Pu, and 241Pu in the samples containing milligram-level 238U. The detection time is reduced to minutes, well fulfilling the requirement of rapid analysis. This method is validated by analyzing the standard reference material and the spiked samples.

Simulation Studies on Recovery of Acetonitrile from Aqueous Acetonitrile Waste from Pharmaceutical Processes

This paper presents simulation studies on the recovery of Acetonitrile from aqueous Acetonitrile waste from pharmaceutical processes. The focus is on atmospheric distillation in two sequential columns to understand the separation feasibility of the system; the first column produces a distillate of azeotropic composition, which is mixed with a fresh stream and fed to a second column, which produces a 99.9% pure Acetonitrile in the residue. The effect of reflux ratio, reboiler duty and the fresh stream flowrate on the purity of the product is analyzed. The study was performed using steady state simulator Aspen Plus, version 11.1. The simulation results indicate that it is possible to obtain a product of 99.9% w/w Acetonitrile from a 1:1 feed with a recovery of ~ 60%.

Ultrafiltration isolation, structure and effects on H1N1-induced acute lung injury of a heteropolysaccharide from Houttuynia cordata

Previous studies showed that crude Houttuynia cordata polysaccharides (CHCP) exerted therapeutic effects on acute lung injury induced by influenza A virus (IAV) in mice. Here, an acidic heteropolysaccharide from H. cordata, named HCPM (Mw, 19.1 kDa), was obtained directly from CHCP using sequential ultrafiltration membrane columns. The backbone of HCPM was consisted of 1, 3, 6-β-Manp, 1, 4-α-GalpA, 1, 2-α-Rhap, and 1, 2, 4-α-Rhap, with main branches of glucan, arabinan, and galactan substituted at C-3 of 1, 3, 6-β-Manp or C-4 of 1, 2, 4-α-Rhap. The structural information was further validated by oligosaccharide sequencing analysis using UPLC-ESI-MS. Furthermore, HCPM exhibited a potent anti-complementary activity with CH50 value of 254.1 ± 7.8 μg/mL in vitro and significantly attenuated IAV-induced lung and gut injuries in vivo by inhibiting viral replication, reducing inflammatory responses, and suppressing complement overactivation. These results suggested that HCPM might be a key H. cordata substance for pulmonary infection treatment.

A novel and greener sequential column leaching approach for the treatment of two different Greek laterites

Τhe present study investigates, from an environmental protection viewpoint, the efficiency of sequential column leaching of two different Greek laterites, i.e. a limonitic ore from central and a saprolitic ore from northern Greece. First, the most refractory limonitic laterite is leached in the first column for 15 days and the obtained pregnant leach solution (PLS) is further used for the leaching of the easier to treat saprolitic ore in the second column, thus achieving a significantly reduced acid consumption. The main parameters affecting the process efficiency, i.e. acid molarity (1.5 or 3 mol/L H2SO4) and addition of sodium sulfite (Na2SO3) in the leaching solution were studied. The extraction of Ni, Co, Fe, Al, Mg, Mn and Ca was determined by Atomic Absorption Spectroscopy (AAS), while the characterization of the ores and final residues was carried out by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA/DTA), and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS) analysis. The results confirm the efficiency of the proposed green approach, which with the use of leaching solution containing 1.5 mol/L H2SO4 and 20 g/L Na2SO3 resulted in 73.8 % Ni, 71.6 % Co and 8.4 % Fe extraction after a short period of time (33 days), while the acid consumption, which is a serious environmental concern, was very low and did not exceed 300 kg/t ore. Overall, the proposed process not only improves the efficiency of leaching of different types of laterites for the recovery of both Ni and Co but also reduces the environmental impacts due to the significantly lower acid consumption.

Sequential Application of Column Leaching and Plant Uptake Tests to Assess the Effect of Various Commercial Amendments on Cu Immobilization in Ultra-High Cu-Contaminated Soil.

The presence of copper (Cu)-contaminated soil has increased recently due to agricultural and industrial activities. Immobilization techniques using soil amendments have attracted significant research because of their cost-effectiveness, eco-friendliness, and community acceptance. This study used various commercial amendments, including magnetite (M), talc (T), activated carbon (AC), and cornstarch (CS), to immobilize Cu in soil contaminated by acidic waste materials with Cu in Korea (9546 ± 5 mg/kg). To evaluate the immobilizing effect of these amendments, this study applied a sequential process of column leaching and plant uptake tests to observe the ability of Cu to remain in soil with and without amendments through the Cu removal rate. The amendments were characterized by SEM, XRD, and specific surface area and applied to the soil at a rate of 2% (w/w). The first stage of evaluation, i.e., the column leaching test, was conducted by continuously pumping distilled water (DW) for 28 days, and the second stage of evaluation, i.e., the plant uptake test, was started immediately after by planting 10-day-old lettuce seedlings for 28 days. The experimental results showed that all of the amendments had a significant effect on Cu immobilization Cu in soil (p < 0.05), and the T treatment showed the highest efficiency in Cu immobilization, with only 47.0% Cu loss compared to 73.5% in the control soil when assessed by sequential column leaching and plant uptake tests. In conclusion, this study provides an effective assessment method to evaluate the effect of amendments on Cu immobilization in soil, as well as providing feasible options to immobilize Cu using commercial amendments.

Simultaneous determination of actinides and 90Sr in large-size soil and sediment samples

A simultaneous analytical method for sequential separation and determination of actinides and 90Sr in large-size environmental samples has been developed. In this method, successive co-precipitation steps were firstly conducted to remove matrix elements, then sequential column separation method was applied for simultaneous separation and purification of actinides and 90Sr/90Y. By using vacuum box technology, the total analytical time was minimized and batch processing allowed analyzing 12 samples in four days. The activity of 90Sr was obtained immediately by measuring its daughter radionuclide (90Y) with triple-to-double coincidence ratio (TDCR) Cherenkov counting, while the concentrations of Pu isotopes and 241Am could be measured by alpha spectrometry and mass spectrometric techniques. The overall recoveries of Pu, Am, Sr and Y were higher than 70% for the entire procedure, while the recovery ratios of Sr/Y were between 0.95 and 1.04 before chromatographic separation. The developed method was verified using 20 g and 50 g of environmental soil samples spiked with certified reference materials IAEA-384 or IAEA-385 and standard solution of 90Sr/90Y, and good agreement between the expected values and measured results has been achieved.

Robust Pricing of Energy and Ancillary Services in Combined Electricity and Natural Gas Markets

Rapid growth of gas-fired generators strengthens the interdependency of electricity and natural gas markets. To meet the uncertainty challenge, a robust day-ahead market clearing framework for the integrated electricity and natural gas system (IEGS) is presented. First, a robust security-constrained unit commitment (SCUC) model is built considering the joint dispatch of ancillary services. Regulation-up/down reserve is scheduled to balance electrical load/wind power uncertainties, spinning reserve is to manage N-1 generator outage, and natural gas reserve is to withstand gas load uncertainty and provide fuel for gas-fired electrical reserve. The SCUC model is a two-stage mixed-integer nonlinear optimization problem so that a sequential linear approximation-based Column & Constraint Generation (SLA-based C&CG) algorithm is proposed. Then, according to SCUC solutions, an economic dispatch model is derived to obtain market clearing and pricing results. Based on locational marginal pricing, novel definitions of electrical energy, natural gas and multiple ancillary service prices are proposed, which can reflect network limits and uncertainty effects. Numerical cases on two test IEGSs and a provincial-level IEGS demonstrate the high accuracy of proposed SLA-based C&CG algorithm and the impact of uncertainties on market clearing.

Purification, characterization of α-galactosidase from a novel Bacillus megaterium VHM1, and its applications in the food industry

An extracellular thermostable α-galactosidase from Bacillus megaterium VHM1 was purified 94.26-fold by precipitation with ethanol, followed by sequential column chromatography with DEAE-Sephacel and G75 column. The purified enzyme was homogeneous on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE). It was found to be a monomeric protein with a molecular weight of about 66 kDa. The purified enzyme showed optimum activity in p-nitrophenyl α-D-galactopyranoside (PNPG) at pH 7.0 and a temperature of 60??C. The enzyme was thermostable, showing complete activity even after heating at 55??C for 60 minutes. The substrate specificity of α-galactosidase on PNPG, ortho-Nitrophenyl-β-galactoside, and raffinose was investigated and Km was found to be 0.508, 0.529, and 5.0 mM and Vmax was 3.492, 4.287, and 14.20 μ mol/ml/minute, respectively. Among the metal ions and reagents tested, Hg2+, Cu2+, and Ag2+ strongly inhibited the α-galactosidase activity, and ethylenediaminetetraacetic acid showed no effect on enzymes. The present study supports the application of α-galactosidase from B. megaterium VHM1 as a potent enzyme in the food processing industry.

A Sustainable and Low-Cost Soil Filter Column for Removing Pathogens from Swine Wastewater: The Role of Endogenous Soil Protozoa

The increase of swine production in the Pacific Islands has inevitably led to environmental pollution concerns from discharged wastewater derived from both washing and manure. The slurry accumulates in lagoons, where supernatant wastewater containing high levels of pathogens and nutrients becomes nonpoint source water pollution that deteriorates the quality of receiving water bodies. Soil filtration is a promising cost-effective technology for removing pollutants from swine wastewater; however, the excessive growth of bacteria in soil media often accompanies the filtration process. This study investigates soil filtration mediated by protozoa activities to remove Escherichia coli (E. coli) in synthetic swine wastewater. The experiment used plastic columns packed with Leilehua soil from Oahu Island, Hawaii. The soil physicochemical adsorption was seen to reduce 95.52–96.47% of E. coli. However, the average removal efficiencies were increased to 98.17% in a single stage, and 99.99% in two sequential columns, under predation conditions. The filtration media containing naturally established bacterivores with the prey, provided a bioactive means to remove E. coli from the influent. The proper design of Leilehua soil filters potentially removes E. coli from the influent to meet the standard level of recycled water.

Damping characteristics of thermal elastohydrodynamic lubricated point contacts

The present work envisaged the development of a novel method for computing the damping coefficients of thermal elastohydrodynamic lubricated point contacts based on energy conservation. The effects of load, entrainment velocity, and slide–roll ratio were studied, and the results were compared with the ISO thermal results. Multi-level method and discrete convolution fast Fourier transform method were employed to improve the solution convergence efficiency, and a sequential column sweeping technique was employed to solve the energy equations. The results indicated an increase in the damping coefficients with an increase in the load, and a corresponding decrease with an increase in the speed. When the entrainment velocity was relatively low, or the slide–roll ratio was relatively small, the influence of the slide–roll ratio was negligible. Subsequently, the relation between the damping coefficients and the load, speed, and slide–roll ratio was established using the least-square method.

Anti-inflammatory effects of 18-nor-ent-pimara-9(11),15-diene-4\u03b2-ol isolated from the roots of Aralia continentalis on LPS-induced in RAW264.7 cells

Aralia continentalis (A. continentalis) is a medicinal plant belonging to Araliaceae, it has been reported to exert anti-cancer, anti-bacterial, anti-inflammatory, anti-platelet and anti-oxidative activities. But the potential mechanism for the anti-inflammatory effect of compounds isolated from the roots of A. continentalis is still insufficient. So, we evaluated whether compounds isolated from the roots of A. continentalis exert anti-inflammatory effects and elucidated its potential mechanism in RAW264.7 cells. The concentrated residue was subsequently suspended in H2O and partitioned with n-hexane, methylene chloride (CH2Cl2), ethyl acetate (EtOAc) and n-butanol (n-BuOH). The fractions were subjected to sequential column chromatography over silica-gel, RP-18, MPLC, recycling and preparative HPLC to isolated the novel compound. The novel compound was identified as 18-nor-ent-pimara-9(11),15-diene-4β-ol and confirmed anti-inflammatory activity. The 18-nor-ent-pimara-9(11),15-diene-4β-ol dose-dependently blocked NO production and inhibited iNOS, COX-2, TNF-α and IL-1β expression in LPS-stimulated RAW264.7 cells. The 18-nor-ent-pimara-9(11),15-diene-4β-ol inhibited LPS-stimulated degradation of IκB-α and nuclear accumulation of p65, which resulted in the suppression of NF-κB activation in RAW264.7 cells. Also, the 18-nor-ent-pimara-9(11),15-diene-4β-ol attenuated the phosphorylation of p38 and ERK1/2 in LPS-induced RAW264.7 cells. These results suggest that the nor-ent-pimara-9(11),15-diene-4β-ol isolated from the roots of A. continentalis may have grate potential for the development of anti-inflammatory drugs.

Single-Stage Posterior Vertebral Column Resection With Circumferential Reconstruction for Thoracic/Thoracolumbar Burst Fractures With or Without Neurological Deficit: Clinical Neurological and Radiological Outcomes.

Study Design:Retrospective study.Objective:The aim of this study is to evaluate the clinical, neurological, and radiological outcomes of posterior vertebral column resection (PVCR) technique for treatment of thoracic and thoracolumbar burst fractures.Methods:Fifty-one patients (18 male, 33 female) with thoracic/thoracolumbar burst fractures who had been treated with PVCR technique were retrospectively reviewed. Preoperative and most recent radiographs were evaluated and local kyphosis angle (LKA), sagittal and coronal spinal parameters were measured. Neurological and functional results were assessed by the American Spinal Injury Association (ASIA) Impairment Scale, visual analogue scale score, Oswestry Disability Index, and Short Form 36 version 2.Results:The mean age was 49 years (range 22-83 years). The mean follow-up period was 69 months (range 28-216 months). Fractures were thoracic in 16 and thoracolumbar in 35 of the patients. AO spine thoracolumbar injury morphological types were as follows: 1 type A3, 15 type A4, 4 type B1, 23 type B2, 8 type C injuries. PVCR was performed in a single level in 48 of the patients and in 2 levels in 3 patients. The mean operative time was 434 minutes (range 270-530 minutes) and mean intraoperative blood loss was 520 mL (range 360-1100 mL). The mean LKA improved from 34.7° to 4.9° (85.9%). For 27 patients, the initial neurological deficit (ASIA A in 8, ASIA B in 3, ASIA C in 5, and ASIA D in 11) improved at least 1 ASIA grade (1-3 grades) in 22 patients (81.5%). Solid fusion, assessed with computed tomography at the final follow-up, was achieved in all patients.Conclusion:Single-stage PVCR provides complete spinal canal decompression, ideal kyphosis correction with gradual lengthening of anterior column together with sequential posterior column compression. Anterior column support, avoidance of the morbidity of anterior approach and improvement of neurological deficit are the other advantages of the single stage PVCR technique in patients with thoracic/thoracolumbar burst fractures.