Management of Symptomatic Sacral Perineural Cysts

BACKGROUND: There has been no consensus on the optimal treatment of symptomatic sacral perineural cysts. Most previous reports concerning the management methods were either sporadic case reports or a series of limited cases. This study is to further optimize the management for patients with symptomatic sacral perineural cysts by analyzing the outcomes of a cohort of patients who were treated with different strategies. METHODS AND FINDINGS: We reviewed the outcomes of 15 patients with symptomatic sacral perineural cysts who were managed by three different modalities from 1998 through 2010. Six patients underwent microsurgical cyst fenestration and cyst wall imbrication. Seven patients underwent a modified surgical procedure, during which the cerebrospinal fluid leak aperture was located and repaired. Two patients were treated with medication and physical therapy. Outcomes of the patients were assessed by following up (13 months to 10 years). All of the six patients treated with microsurgical cyst fenestration and cyst wall imbrication experienced complete or substantial relief of their preoperative symptoms. However, the symptoms of one patient reappeared eight months after the operation. Another patient experienced a postoperative cerebrospinal fluid leakage. Six of the seven patients treated with the modified surgical operation experienced complete or substantial resolution of their preoperative symptoms, with only one patient who experienced temporary worsening of his preoperative urine incontinence, which disappeared gradually one month later. No new postoperative neurological deficits, no cerebrospinal fluid leaks and no recurrence were observed in the seven patients. The symptoms of the two patients treated with conservative measures aggravated with time. CONCLUSIONS: Microsurgical operation should be a treatment consideration in patients with symptomatic sacral perineural cysts. Furthermore, the surgical procedure with partial cyst removal and aperture repair for prevention of cerebrospinal fluid leakage seemed to be more simple and effective

Knowledge-Based Reconstruction of mRNA Transcripts with Short Sequencing Reads for Transcriptome Research

While most transcriptome analyses in high-throughput clinical studies focus on gene level expression, the existence of alternative isoforms of gene transcripts is a major source of the diversity in the biological functionalities of the human genome. It is, therefore, essential to annotate isoforms of gene transcripts for genome-wide transcriptome studies. Recently developed mRNA sequencing technology presents an unprecedented opportunity to discover new forms of transcripts, and at the same time brings bioinformatic challenges due to its short read length and incomplete coverage for the transcripts. In this work, we proposed a computational approach to reconstruct new mRNA transcripts from short sequencing reads with reference information of known transcripts in existing databases. The prior knowledge helped to define exon boundaries and fill in the transcript regions not covered by sequencing data. This approach was demonstrated using a deep sequencing data set of human muscle tissue with transcript annotations in RefSeq as prior knowledge. We identified 2,973 junctions, 7,471 exons, and 7,571 transcripts not previously annotated in RefSeq. 73% of these new transcripts found supports from UCSC Known Genes, Ensembl or EST transcript annotations. In addition, the reconstructed transcripts were much longer than those from de novo approaches that assume no prior knowledge. These previously un-annotated transcripts can be integrated with known transcript annotations to improve both the design of microarrays and the follow-up analyses of isoform expression. The overall results demonstrated that incorporating transcript annotations from genomic databases significantly helps the reconstruction of novel transcripts from short sequencing reads for transcriptome research

Polyacrylonitrile-encapsulated amorphous zirconium phosphate composite adsorbent for Co, Nd and Dy separations

Recycled Nd and Dy from the end-of-life NdFeB permanent magnet is an important supplement for the increasing demand of rare-earth elements. Thus, there is an urgent need to develop an environmentally friendly recycling method. Amorphous zirconium phosphate exhibits selective separation properties towards the ternary Co-Nd-Dy system, however, its powdery form limits development of scaled-up applications. We present an efficient amorphous ZrP/Polyacrylonitrile (am-ZrP/PAN) composite ion exchanger for uptake and separation of Nd, Dy and Co. The am-ZrP/PAN composite was synthesized and its structural, morphologic and acidic properties were investigated by various methods. X-ray tomography revealed rather evenly distributed am-ZrP in the PAN polymer matrix. The selectivity and ion-exchange kinetics of the am-ZrP/PAN composite were determined in relation to the individual elements. Due to dimethylformide (DMF) intercalation into the interlayer of ZrP, the uptake of Co, Nd and Dy increased 50% compared with that of the pristine am-ZrP. Column separation of Co, Nd and Dy from the Co-Nd-Dy ternary system was assessed by varying the feed concentration, loading degree, temperature, running speed and elution agent (HNO3) concentration. Finally, gradient elution was employed for Co, Nd and Dy separation from a simulated ternary leachate. Fractions with 87.9% pure Co, 96.4% pure Nd and 40% pure Dy were collected through a single-column operation.Peer reviewe

Selective ion-exchange separation of scandium(III) over iron(III) by crystalline alpha-zirconium phosphate platelets under acidic conditions

A continuous worldwide increase in scandium (Sc) criticality leads to a quest for secondary scandium resources. Among them, bauxite residue (BR) – a waste product from alumina refineries – often contains substantial amounts of scandium. However, the complexity in BR composition drives the need for developing a selective, efficient and cost-effective process to achieve the separation and purification of scandium. Insoluble salts of tetravalent metal ions are inorganic, acid-resistant ion exchangers with well-established preparation procedures, but their potential use in rare-earth recovery and purification has not been extensively explored yet. Zirconium and titanium phosphates, both in amorphous and α-layered crystalline forms, were screened for Sc(III)/Fe(III) separation, as Fe(III) is one of the base elements in BR that is the most challenging to separate from Sc(III). The studied α-zirconium phosphate (α-ZrP, Zr(HPO4)2·H2O) exhibited the highest Sc(III)/Fe(III) separation factors (up to approximately 23) from HCl solutions. The metal selectivity of α-ZrP was considered to be affected by the solution pH, and the size and hydration enthalpy of the metal cations. Breakthrough curves for a binary Sc(III)/Fe(III) solution, composed of metal concentrations realistic to a typical BR leachate, revealed the selectivity of α-ZrP for Sc(III). Furthermore, chromatographic separation of Sc(III) from a real HCl leachate of BR was successfully achieved on an α-ZrP column. After a two-step elution with HCl about 60 % of Sc(III) was collected in fractions without measurable Fe(III), Al(III) or other rare-earth impurities. Overall, this study highlights the possibility for direct and simplified separation of Sc(III) from a much higher concentration of Fe(III) in BR, without the need of using reducing agents.Peer reviewe

Efficient and Selective Recovery of Trace Scandium by Inorganic Titanium Phosphate Ion-Exchangers from Leachates of Waste Bauxite Residue

The research leading to these results has received funding from the European Union (EU) Horizon 2020 Programme Marie Skłodowska-Curie actions under Grant Agreement no. 636876 (MSCA-ETN REDMUD).Bauxite residue (BR) is an inevitable industrial waste generated through the classic Bayer extraction of alumina from bauxite minerals. It contains relatively significant amount of valuable rare earth elements, including scandium, and therefore, we explored the suitability of trace scandium recovery from BR acid leachate by titanium phosphate (TiP) ion exchangers. Three kinds of TiP materials (amorphous TiP, α-TiP, and γ-TiP) were synthesized through fluorine-free precursors and characterized by chemical analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR), ultraviolet/visible (UV/vis) diffuse reflectance spectrometry, 31P magic angle spinning (MAS) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and potentiometric titration. The Sc3+ exchange capacities were determined as 1.74, 0.55, and 0.22 mequiv g–1 for amorphous, α-, and γ-TiP, respectively. Competition of major elements (Fe, Al, Ca) in BR leachate with Sc uptake were studied in batch experiments using binary equimolar mixtures, and the separation factors of Sc/Fe2+, Sc/Al, and Sc/Ca reached magnitudes of 10–1000 on amorphous TiP. The high Sc3+selectivity by amorphous TiP was suspected to be the matching of Ti4+ lattice radius with Sc3+ ionic radius (both 0.745 Å). Finally, the separation of trace scandium from the simulated BR leachate solution was demonstrated on an amorphous TiP column. The interference of Fe3+ has been partially resolved by on-column reduction using sodium sulphite. The optimized final eluate contained only Sc, Fe, and Al. The concentration ratio of Sc/Fe can be increased by a factor of 8.8 and Sc/Al by 265 through a single cycle of chromatographic separation with an Sc recovery rate of 91.1%.Peer reviewe

Variable pitch approach for performance improving of straight-bladed VAWT at rated tip speed ratio

This paper presents a new variable pitch (VP) approach to increase the peak power coefficient of the straight-bladed vertical-axis wind turbine (VAWT), by widening the azimuthal angle band of the blade with the highest aerodynamic torque, instead of increasing the highest torque. The new VP-approach provides a curve of pitch angle designed for the blade operating at the rated tip speed ratio (TSR) corresponding to the peak power coefficient of the fixed pitch (FP)-VAWT. The effects of the new approach are exploited by using the double multiple stream tubes (DMST) model and Prandtl’s mathematics to evaluate the blade tip loss. The research describes the effects from six aspects, including the lift, drag, angle of attack (AoA), resultant velocity, torque, and power output, through a comparison between VP-VAWTs and FP-VAWTs working at four TSRs: 4, 4.5, 5, and 5.5. Compared with the FP-blade, the VP-blade has a wider azimuthal zone with the maximum AoA, lift, drag, and torque in the upwind half-cycle, and yields the two new larger maximum values in the downwind half-cycle. The power distribution in the swept area of the turbine changes from an arched shape of the FP-VAWT into the rectangular shape of the VP-VAWT. The new VP-approach markedly widens the highest-performance zone of the blade in a revolution, and ultimately achieves an 18.9% growth of the peak power coefficient of the VAWT at the optimum TSR. Besides achieving this growth, the new pitching method will enhance the performance at TSRs that are higher than current optimal values, and an increase of torque is also generated

Solid lipid nanoparticle suspension enhanced the therapeutic efficacy of praziquantel against tapeworm

Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and −11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ

Separation of cobalt, neodymium and dysprosium using amorphous zirconium phosphate

The purpose of this study was to investigate the separation of Co, Nd and Dy from a ternary Co-Nd-Dy solution using amorphous zirconium phosphate (am-ZrP). Am-ZrP was synthesized by a precipitation method at room temperature and subsequently characterized by Fourier transform-infrared spectrometry, thermogravimetry, scanning electron microscopy, X-ray diffraction, solid-state 31P magic angle spinning nuclear magnetic resonance spectrometry and sodium hydroxide titration (with and without background salt). The ion exchange kinetics of am-ZrP that were determined in ternary 1 mM equimolar solutions at equilibrium pH 2.5. The effect of pH on the adsorption was studied in ternary 1 mM equimolar solutions and the uptakes of the metals increased with increasing pH until approximately pH 3.5. The adsorption isotherms of Co, Nd and Dy were tested in a series of ternary equimolar solution, the total uptake amounted to 4.13 meq/g at pH ~ 3.0. The preference of am-ZrP for these metals occurred in decreasing order Dy > Nd ≫ Co. The separation of Co, Nd and Dy from their 1 mM equimolar ternary mixture was investigated on an am-ZrP column. Effects of loading (7.8%, 62% and 100%) on the separation were compared by measuring the corresponding HNO3 elution fractions. It was found that with a lower metal loading of 7.8%, three clear elution bands were obtained. Am-ZrP exhibited selective separation properties towards the ternary Co-Nd-Dy system, which contribute to the future scale-up studies for the recycling of NdFeB magnets.Peer reviewe