Medium optimization for endochitinase production by recombinant Pichia pastoris ZJGSU02 using response surface methodology

Plackett-Burman design and response surface methodology were employed to optimize the medium components for endochitinase production by Pichia pastoris. A Plackett- Burman design of seven factors with 12 runs was applied to evaluate the effects of different medium components. Yeast extract, oleic acid and Tween-80 were found to have significant influence on endochitinase production. The optimal concentrations of three factors were investigated by the response surface methodology using Box- Behnken design. The optimal medium components obtained for achieving the maximum activity of the endochitinase were as follows: Yeast extract 24.36 g/l, tryptone 20 g/l, YNB 5.0 g/l, potassium phosphate 100 mM, methanol 5 ml/l, oleic acid 1.758 ml/l, Tween-80 6.2 ml/l, Pichia trace metals (PTM1) 4.0 ml/ l and biotin 4.00 × 10-4 g/l. Under these conditions, endochitinase activity was up to 88.26 μ/ml, which was about 1.14-fold higher than using the original medium (77.62 μ/ml). This work will be very helpful for large-scale production of endochitinase for future industrial application.Keywords: Recombinant endochitinase, Plackett-Burman design, response surface methodology, fermentatio

Optimized Design on the Width and Spacing of the Cross Passageway in Tunnels

AbstractCross passageways have been commonly applied in the evacuation system of tunnels, and the width and spacing of the cross passageways decide the evacuation capacity of the tunnel. In design, increasing the width of the cross passageways and reducing their spacing can improve the evacuation ability of tunnels. However, it will certainly increase the cost of the project. Under the precondition of meeting evacuation requirements, an optimization model was established in this article, which aimed at reducing the cost of the project. Finally, discussions on the application of this optimization model were carried on, and this method may provide reference for designing cross passageways

Transient analysis for hypersonic inlet accelerative restarting process

A three-dimensional computational fluid dynamics code that solves the unsteady compressible Reynolds-averaged Navier–Stokes equations was used to investigate the transient accelerative restarting processes of a planar hypersonic inlet. The characteristics of the accelerative restarting process were analyzed, and they revealed that the wall pressure time histories could be used to monitor whether the hypersonic inlet restarted. In addition, the effects of acceleration and flight trajectories on the transient accelerative process were studied. The results showed that the process of the disappearance of the separation bubble was delayed as the acceleration was increased. As a result, the corresponding flight Mach number at which the inlet restarted increased accordingly. The unsteady simulation results also indicated that the trajectory had great impact on the accelerative restarting process

Combining Coauthorship Network and Content for Literature Recommendation

This paper studies literature recommendation approaches using both content features and coauthorship relations of articles in literature databases. Most literature databases allow data access (via site subscription) without having to identify users, and thus task-focused recommendation is more appropriate in this context. Previous work mostly utilizes content and usage log for making task-focused recommendation. More recent works start to incorporate coauthorship network for recommendation and found it beneficial when the specified articles preferred by authors are similar in their content. However, it was also found that recommendation based on content features achieves better performance under other circumstances. Therefore, in this work we propose to incorporate both content and coauthorship network in making task-focused recommendation. Three hybrid methods, namely switching, proportional, and fusion are developed and compared. Our experimental results show that in general the proposed hybrid approach achieves better performance than approaches that utilize only one source of knowledge. In particular, the fusion method tends to have higher recommendation accuracy for articles of higher ranks. Besides, the content-based approach is more likely to recommend articles of low fidelity, whereas the coauthorship network-based approach has the least chance

Wildfire: distributed, Grid-enabled workflow construction and execution

BACKGROUND: We observe two trends in bioinformatics: (i) analyses are increasing in complexity, often requiring several applications to be run as a workflow; and (ii) multiple CPU clusters and Grids are available to more scientists. The traditional solution to the problem of running workflows across multiple CPUs required programming, often in a scripting language such as perl. Programming places such solutions beyond the reach of many bioinformatics consumers. RESULTS: We present Wildfire, a graphical user interface for constructing and running workflows. Wildfire borrows user interface features from Jemboss and adds a drag-and-drop interface allowing the user to compose EMBOSS (and other) programs into workflows. For execution, Wildfire uses GEL, the underlying workflow execution engine, which can exploit available parallelism on multiple CPU machines including Beowulf-class clusters and Grids. CONCLUSION: Wildfire simplifies the tasks of constructing and executing bioinformatics workflows

A five-year experience in endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma

Introduction: Juvenile nasopharyngeal angiofibroma (JNA) is a histological benign but locally aggressive vascular tumour which can invade the base of skull. Aim: This is a retrospective study with the aim to examine the outcome of patients with JNA and endoscopic endonasal excision of tumour at a tertiary center in Malaysia. Material and methods: 9 patients were identified from the medical record office from 2015 to 2019. We review the data on patient demographics, clinical presentations, laboratory investigations, intraoperative blood loss and duration of hospital stay. Results and discussion: 8 patients were male, 1 was female. The average age of diagnosis was 15 (range 11 to 29) years. The commonest chief complaint was recurrent epistaxis, followed by nasal obstruction and nasal discharge. Three patients were at stage I, 4 patients at stage II, 1 patient at stage III and 1 patient at stage IV based on Fisch classification. All patients underwent primary endoscopic endonasal excision of tumour with no vascular, ophthalmological or neurological complication. Seven patients had preoperative embolization done. Average operation time was 137 minutes (range 60–360 minutes). Intraoperative blood lost varied from 500 mL to 1300 mL (mean 777.7 mL). All patients were discharged well with no recurrence. Conclusions: The management of JNA can be challenging. The current shift in management favouring endoscopic endonasal excision of JNA reduces postoperative morbidity. It is possible to be applied on all stages of tumour with good success rate

The Involvement of Neuron-Specific Factors in Dendritic Spinogenesis: Molecular Regulation and Association with Neurological Disorders

Dendritic spines are the location of excitatory synapses in the mammalian nervous system and are neuron-specific subcellular structures essential for neural circuitry and function. Dendritic spine morphology is determined by the F-actin cytoskeleton. Factin remodeling must coordinate with different stages of dendritic spinogenesis, starting from dendritic filopodia formation to the filopodia-spines transition and dendritic spine maturation and maintenance. Hundreds of genes, including F-actin cytoskeleton regulators, membrane proteins, adaptor proteins, and signaling molecules, are known to be involved in regulating synapse formation. Many of these genes are not neuron-specific, but how they specifically control dendritic spine formation in neurons is an intriguing question. Here, we summarize how ubiquitously expressed genes, including syndecan-2, NF1 (encoding neurofibromin protein), VCP, and CASK, and the neuron-specific gene CTTNBP2 coordinate with neurotransmission, transsynaptic signaling, and cytoskeleton rearrangement to control dendritic filopodia formation, filopodia-spines transition, and dendritic spine maturation and maintenance. The aforementioned genes have been associated with neurological disorders, such as autism spectrum disorders (ASDs), mental retardation, learning difficulty, and frontotemporal dementia. We also summarize the corresponding disorders in this report

A five-year experience in endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma

Introduction: Juvenile nasopharyngeal angiofibroma (JNA) is a histological benign but locally aggressive vascular tumour which can invade the base of skull. Aim: This is a retrospective study with the aim to examine the outcome of patients with JNA and endoscopic endonasal excision of tumour at a tertiary center in Malaysia. Material and methods: 9 patients were identified from the medical record office from 2015 to 2019. We review the data on patient demographics, clinical presentations, laboratory investigations, intraoperative blood loss and duration of hospital stay. Results and discussion: 8 patients were male, 1 was female. The average age of diagnosis was 15 (range 11 to 29) years. The commonest chief complaint was recurrent epistaxis, followed by nasal obstruction and nasal discharge. Three patients were at stage I, 4 patients at stage II, 1 patient at stage III and 1 patient at stage IV based on Fisch classification. All patients underwent primary endoscopic endonasal excision of tumour with no vascular, ophthalmological or neurological complication. Seven patients had preoperative embolization done. Average operation time was 137 minutes (range 60–360 minutes). Intraoperative blood lost varied from 500 mL to 1300 mL (mean 777.7 mL). All patients were discharged well with no recurrence. Conclusions: The management of JNA can be challenging. The current shift in management favouring endoscopic endonasal excision of JNA reduces postoperative morbidity. It is possible to be applied on all stages of tumour with good success rate