Application of biodegradable 3D-printed cage for cervical diseases via anterior cervical discectomy and fusion (ACDF): an in vitro biomechanical study

Objectives

To design and fabricate a 3D-printed cervical cage composite of polylactic acid (PLA)/nano-sized and β-tricalcium phosphate (β-TCP).

Results

CAD analysis provided a useful platform to design the preliminary cage. In vitro cell culture and in vivo animal results showed promising results in the biocompatibility of the constructs. Endplate matching evaluation showed better matching degree of 3D-printed cages than those of conventional cages. Biomechanical evaluation showed better mechanical properties of 3D-printed cages than those of conventional cages.

Conclusion

The novel 3D printed PLA/pβ-TCP cage showed good application potential, indicating a novel, feasible, and inexpensive method to manufacture cervical fusion cages.

     

Fabrication optimisation of carbon fiber electrode with Taguchi method

In this study, we describe an optimised procedure for fabricating carbon fiber electrodes using Taguchi quality engineering method (TQEM). The preliminary results show a S/N ratio improvement from 22 to 30 db (decibel). The optimised parameter was tested by using a glass micropipette (0.3 mm outer/2.5 mm inner length of carbon fiber) dipped into PBS solution under 2.9 V triangle-wave electrochemical processing for 15 s, followed by coating treatment of micropipette on 2.6 V DC for 45 s in 5% Nafion solution. It is thus shown that Taguchi process optimisation can improve cost, manufacture time and quality of carbon fiber electrodes.     

Study of cryopreservation of articular chondrocytes using the Taguchi method

This study evaluates the effect of control factors on cryopreservation of articular cartilage chondrocytes using the Taguchi method. Freeze-thaw experiments based on the L₈(2⁷) two-level orthogonal array of the Taguchi method are conducted, and ANOVA (analysis of variables) is adopted to determine the statistically significant control factors that affect the viability of the cell. Results show that the type of cryoprotectant, freezing rate, thawing rate, and concentration of cryoprotectant (listed in the order of influence) are the statistically significant control factors that affect the post-thaw viability. The end temperature and durations of the first and second stages of freezing do not affect the post-thaw viability. Within the ranges of the control factors studied in this work, the optimal test condition is found to be a freezing rate of 0.61 ± 0.03 °C/min, a thawing rate of 126.84 ± 5.57 °C/min, Me₂SO cryoprotectant, and a cryoprotectant concentration of 10% (v/v) for maximum cell viability. In addition, this study also explores the effect of cryopreservation on the expression of type II collagen using immunocytochemical staining and digital image processing. The results show that the ability of cryopreserved chondrocytes to express type II collagen is reduced within the first five days of monolayer culture.     

Measurement of spontaneous motility in vitro of the cervical ring in sheep

Spontaneous motility has been observed within in vitro preparations by different annulars of the cervix, as well as the characteristics shown this structure. This motor activity is cyclic, amplitude and tone not changing from some annulars to others, working on two grammes tension, but frequency and rhythm show large changes, altering the frequency from 7.3 contractions to minute in the first annular to 4.05 in the fifth annular. However, there appears denticulate peaks, with an incidence of 11% in the first annular, growing to 100% in the fifth annular.     

Optimization of an anti-HER2 nanobody expression using the Taguchi method

Despite being widely used in immunotherapy of cancer, whole antibodies are limited by several disadvantages. This has led to the advent of novel biomolecules such as nanobodies. Taguchi method is a statistical experimental design to study the effect of multiple variables in biological processes. In an effort to overexpress a recombinant anti-human epidermal growth factor receptor type 2 (HER2) nanobody, we performed a detailed study to find optimal condition of temperature, induction, culture media, vector, and host strain, using Taguchi methodology. A total of 16 various experiments were designed. Total protein of the formulated cultures were assessed by Bradford test and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by size exclusion high performance liquid chromatography to quantify the relative concentration of the nanobody in different expression settings. Western blotting was performed to confirm the expression of the anti-HER2 nanobody. When, individually, optimum parameters determined by Taguchi were applied, including SHuffle strain cultured in LB medium, induced with 0.4?mM isopropyl-β-D-thio-galactoside for 18?h at 24°C, production yield further increased by about 9% (25.4?mg/L), compared to the highest expression setting. Flow cytometry and enzyme-linked immunosorbent assay result indicated improved protein binding in optimized conditions. Overall, our findings provide a basis for further investigations on economical production of recombinant nanobodies to improve production yield and activity.     

Optimization of ultrasound-assisted production of ergosterol from Penicillium brevicompactum by Taguchi statistical method

Ergosterol as a primary metabolite and precursor of vitamin D2, is the most plentiful mycosterols in fungal cell membrane. Process optimization to increase the yield and productivity of biological products is a topic of interest. Ultrasonic waves have many applications in biotechnology, like cell disruption, and enhancement of primary and secondary metabolites production. This study disclosed an optimal condition for ultrasound-assisted production (UAP) of ergosterol from Penicillium brevicompactum MUCL 19,011 using L₉ Taguchi statistical method. The intensity (IS), time of sonication (TS), treatment frequency (TF), and number of days of treatment (DT) were allocated to study the effects of ultrasound on ergosterol production. The results were analyzed using Minitab version 19. The maximum ergosterol, 11 mg/g cell dry weight (CDW), was produced on the tenth day while all factors were at a low level. The days of treatment with a contribution of 45.48% was the most significant factor for ergosterol production. For the first time, this study revealed the positive effect of ultrasound on the production of ergosterol. Ergosterol production increased 73% (4.63 mg/g CDW) after process optimization. Finally, a mathematical model of ultrasound factors with a regression coefficient of R²?=?0.978 was obtained for the ergosterol production during ultrasound treatment.

     

Isolation and characterization of distillery spent wash color reducing bacteria and process optimization by Taguchi approach

The ability of five different types of bacterial strains isolated from a distillery mill site was analyzed for decolorization of distillery spent wash. 16S rDNA based denaturing gradient gel electrophoresis (DGGE) and amplified random DNA restriction analysis (ARDRA) were used to characterize the bacterial strains. One of the isolates had higher capability to reduce color (21%) and chemical oxygen demand (COD) (30%) was finally identified by 16S rDNA sequence analysis as Bacillus sp. Different parameters such as pH, temperature, aeration,% carbon,% nitrogen, inoculum size and incubation time were optimized by the Taguchi approach to achieve maximum decolorization of distillery spent wash by the Bacillus sp. Reduction in color (85%) and COD (90%) was observed within 12 h after optimization by the Taguchi method. The significant factor in the optimization process was duration followed by inoculum size to attain maximum color reduction. The Taguchi approach proved to be a reliable tool in optimizing culture conditions and analyzing interaction effects of process parameters in achieving the best possible combination for maximum decolorization of the distillery spent wash.     

Application of modified Rosenbrock's method for optimization of nutrient media used in microorganism culturing.

The Rosenbrock's procedure has been modified for optimization of nutrient medium composition and has been found to be less tedious than the Box-Wilson method, especially for larger numbers of optimized parameters. Its merits are particularly obvious with multiparameter optimization where the gradient method, so far the only one employed in microbiology from a variety of optimization methods (e.g., refs, 9 and 10), becomes impractical because of the excessive number of experiments required. The method suggested is also more stable during optimization than the gradient methods which are very sensitive to the selection of steps in the direction of the gradient and may thus easily shoot out of the optimized region. It is also anticipated that other direct search methods, particularly simplex design, may be easily adapted for optimization of medium composition. It is obvious that direct search methods may find an application in process improvement in antibiotic and related industries.     

前路减压加Cage椎间融合器植入治疗脊髓型颈椎病36例临床观察

目的:探讨前路减压加Cage椎间融合器植入治疗脊髓型颈椎病的方法和疗效.方法:脊髓型颈椎病患者36例,病变累及1个节段者32倒,累及2个节段者4例.全部前路减压加Cage椎间融合器植入治疗.结果:术前JOA评分、术前颈椎高度分别为6.7±0.5、35.4±5.32,术后3月15.7±1.3,38.7±5.82,二者相比P＜0.01,差异有显著性,具有统计学意义;术后1年随访同术后差异无显著性;36例病人全部融合,椎间融合良好,无移位及假关节形成.结论:前路减压加Cage椎间融合器植入是治疗脊髓型颈椎病安全有效的方法.临床效果肯定.     

Sequence classification with side effect machines evolved via ring optimization

The explosion of available sequence data necessitates the development of sophisticated machine learning tools with which to analyze them. This study introduces a sequence-learning technology called side effect machines. It also applies a model of evolution which simulates the evolution of a ring species to the training of the side effect machines. A comparison is done between side effect machines evolved in the ring structure and side effect machines evolved using a standard evolutionary algorithm based on tournament selection. At the core of the training of side effect machines is a nearest neighbor classifier. A parameter study was performed to investigate the impact of the division of training data into examples for nearest neighbor assessment and training cases. The parameter study demonstrates that parameter setting is important in the baseline runs but had little impact in the ring-optimization runs. The ring optimization technique was also found to exhibit improved and also more reliable training performance. Side effect machines are tested on two types of synthetic data, one based on GC-content and the other checking for the ability of side effect machines to recognize an embedded motif. Three types of biological data are used, a data set with different types of immune-system genes, a data set with normal and retro-virally derived human genomic sequence, and standard and nonstandard initiation regions from the cytochrome-oxidase subunit one in the mitochondrial genome.     

Codman颈椎前路钢板系统在脊髓型颈椎病中的应用（附96例报道）

目的：探讨Codman颈椎前路钢板系统治疗脊髓型颈椎病的临床运用疗效。方法：采用Codman颈椎前路钢板系统对96例脊髓型颈椎病患者行前路减压,植骨融合,钢板内固定术。结果：术后经6-14月门诊复查或随诊,全部患者术后症状明显改善或消失,颈椎椎间高度维持良好,植骨全部融合,未出现钢板、螺钉、松动或断裂。结论：Codman颈椎前路钢板系统是一种操作较为方便、安全、有效,固定牢靠的颈椎内固定器械。     

Ketopiperazine-based renin inhibitors: optimization of the "C" ring

A systematic investigation of the S3 sub-pocket activity requirements was conducted. It was observed that linear and sterically small side chain substituents are preferred in the S3 sub-pocket for optimal renin inhibition. Polar groups in the S3-sub-pocket were not well tolerated and caused a reduction in renin inhibitory activity. Further, compounds with clog P's < or = 3 demonstrated a dramatic reduction in CYP3A4 inhibitory activity.     

A field cage method for assessing resistance to turnip root fly in brassicas

A field cage method was evaluated as an alternative to field trials for identifying sources of resistance to turnip root fly in brassicas. This involved the controlled release of adult flies and the use of egg traps to quantify egg-laying on potted plants. Overall levels of resistance to Delia floralis, and its components, were assessed for 15 swede genotypes. Significant levels of antixenosis and antibiosis type resistance were identified in several cultivars and breeding lines. There was a close agreement between the field cage results and those from previous field trials, using comparable susceptible and resistance control cultivars. Compared with field selection, the field cage method reduced by c. 40% the time required to quantify resistance and each of its components.     

寡核苷酸合成的一种优化方法

为提高寡核苷酸的合成效率,结合本实验室研制出的探针并行合成装置,提出了一种寡核苷酸合成的优化方法,可有效减少合成的循环次数,同时使合成成本降低、合成时间缩短,合成效率大大提高。     

Film analysis of activated sludge microbial discs by the Taguchi method and grey relational analysis

A biofilm model with substrate inhibition is proposed for the activated sludge growing discs of rotating biological contactor (RBC); this model is different from the steady-state biofilm model based on the Monod assumption. Both deep and shallow types of biofilms are examined and discussed. The biofilm models based on both Monod and substrate inhibition (Haldane) assumptions are compared. In addition, the relationships between substrate utilization rate, biofilm thickness, and liquid phase substrate concentration are discussed. The influence order of the factors that affect the biofilm thickness is studied and discussed by combining the Taguchi method and grey relational analysis. In this work, a Taguchi orthogonal table is used to construct the series that is needed for grey relational analysis to determine the influence priority of the four parameters S _B , kX _f , K _s, and K _i .     

Application of periostin peptide-decorated self-assembled protein cage nanoparticles for therapeutic angiogenesis

Peptides are gaining substantial attention as therapeutics for human diseases. However, they have limitations such as low bioavailability and poor pharmacokinetics. Periostin, a matricellular protein, can stimulate the repair of ischemic tissues by promoting angiogenesis. We have previously reported that a novel angiogenic peptide (amino acids 142-151) is responsible for the pro-angiogenic activity of periostin. To improve the in vivo delivery efficiency of periostin peptide (PP), we used proteins self-assembled into a hollow cage-like structure as a drug delivery nanoplatform in the present study. The periostin peptide was genetically inserted into lumazine synthase (isolated from Aquifex aeolicus) consisting of 60 identical subunits with an icosahedral capsid architecture. The periostin peptide-bearing lumazine synthase protein cage nanoparticle with 60 periostin peptides multivalently displayed was expressed in Escherichia coli and purified to homogeneity. Next, we examined angiogenic activities of this periostin peptide-bearing lumazine synthase protein cage nanoparticle. AaLS-periostin peptide (AaLS-PP), but not AaLS, promoted migration, proliferation, and tube formation of human endothelial colony-forming cells in vitro. Intramuscular injection of PP and AaLS-PP increased blood perfusion and attenuated severe limb loss in the ischemic hindlimb. However, AaLS did not increase blood perfusion or alleviate tissue necrosis. Moreover, in vivo administration of AaLS-PP, but not AaLS, stimulated angiogenesis in the ischemic hindlimb. These results suggest that AaLS is a highly useful nanoplatform for delivering pro-angiogenic peptides such as PP.     

Application of mathematical optimization methods in microbiology

Mathematical methods of experiment design have so far found little use in the optimization of microbiological processes. The conventional optimization procedure is still the transformation of functional relationship ofn variables into n unidimensional optimizations; furthermore, the Bos-Wilson gradient method is often used. This paper presents a review of methods used in other fields, and their application in microbiological practice. The methods are classified according to whether they require, besides the simple determination of the objective function (direct search methods), also the finding of its first (gradient methods) or second derivative (Newton-Raphson method). A modified Rosenbrock’s method of direot optimum search and the gradient Box-Wilson method were used in parallel for the optimization of yeast growth on methanol. Their comparison showed that Bosenbrock’s method is more suitable for multiparameter systems.     

Another method for specifying furanose ring puckering.

A set of pseudorotation coordinates is proposed for characterizing the puckering of the furanose ring. These are defined from the curvilinear displacements of the C1' and C4' atoms from the planar conformation. The present coordinates have some practical advantages over the ones currently used.