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Familial occurrence of intracranial ependymoma, in the absence of neurofibromatosis type 2 (NF2), is very rare with only a few cases reported in the literature. We report a 62-year-old man, who presented with a posterior fossa ependymoma with the majority of the lesion in the cerebellopontine angle, mimicking an extra-axial tumour. His two brothers also had 4th ventricular ependymomas requiring surgical resection. Such cases add weight to the suggestion of a genetically predisposing mutation in familial cases of intracranial ependymomas. Further genetic testing may help to elucidate the location of the genetic abnormality in patients with non-NF2 familial intracranial ependymomas and promote a better understanding of this rare pathological entity.

Cauda equina paragangliomas are neuroendocrine tumours rarely encountered in neurosurgical practice. Large cauda equina paragangliomas with an intradural and extradural component, dense adhesion to nerve roots and high vascularity are surgically challenging and mandate meticulous operative dissection. The presence of extensive bony erosion can lead to spinal instability requiring solid instrumentation and fixation. We recommend resection of large cauda equina paragangliomas in a staged fashion with the aim of gross total resection and spinal stabilisation.

We report fabrication and measurements of hexagonal boron nitride (h-BN)/chemical vapor deposition (CVD) graphene/h-BN heterostructure devices without using expensive, time-consuming electron-beam lithography and toxic carbon tetrafluoride or sulfur tetrafluoride etching. We use efficient transfer of h-BN/CVD graphene by polypropylene carbonate onto a pre-prepared metal contacts/h-BN/SiO2 substrate. In this case, CVD-graphene is suspended from the h-BN substrate which allows efficient gas annealing process for improving the device mobility. Interestingly, we find that the top h-BN capping layer could enhance the carrier interference effect in CVD graphene, a great advantage for low-cost graphene-based interference-type electronic devices.

Homogeneous, single-crystal, monolayer epitaxial graphene (EG) is the one of most promising candidates for the advancement of quantized Hall resistance (QHR) standards. A remaining challenge for the electrical characterization of EG-based quantum Hall devices as a useful tool for metrology is that they are electrically unstable when exposed to air due to the adsorption of and interaction with atmospheric molecular dopants. The resulting changes in the charge carrier density become apparent by variations in the surface conductivity, the charge carrier mobility, and may result in a transition from n-type to p-type conductivity. This work evaluates the use of Parylene C and Parylene N as passivation layers for EG. Electronic transport of EG quantum Hall devices and non-contact microwave perturbation measurements of millimeter-sized areas of EG are both performed on bare and Parylene coated samples to test the efficacy of the passivation layers. The reported results, showing a significant improvement in passivation due to Parylene deposition, suggest a method for the mass production of millimeter-scale graphene devices with stable electrical properties.

In this paper, a novel prototype liquid-air dual gradient chip is introduced, which has paved the way for effective synergic effect bio-evaluation of air pollutant. The chip is composed of an array of the agarose liquid-air interfaces, top air gradient layer and bottom liquid gradient layer. The novel agarose liquid-air interface allows for non-biased exposure of cells to all the substances in the air and diffusive interactions with the liquid phase; while the dual liquid-air gradient provides powerful screening abilities, which well reduced errors, saved time and cost from repeated experiment. Coupling the two functions, the chip subsequently facilitates synergic effect evaluation of both liquid and air factors on cells. Here cigarette smoke was taken as the model air pollutant, and its strong synergic effects with inflammatory level of A549 lung cancer cells on their fate were successfully quantified for the first time. These results well testified that the proposed dual-gradient chip is powerful and indispensable for bio-evaluation of air pollutant.

In an attempt to arrive at a more potent cytotoxic agent than the parent compound α-hederagenin (H), 24 α-hederagenin derivatives (5–8, 11–24, 27–28, 31–32, and 35–36) were synthesized in a concise and efficient strategy and screened for in vitro cytotoxicity against the human cancer cell lines MKN45 and KB. Among these compounds, the polyamine derivative 15 exhibited more potency than the parent compound with IC50 values in the range of 4.22 μM–8.05 μM. Compound 15 increased Bax/bcl-2 ratio that disrupted the mitochondrial potential and induced apoptosis. Therefore, the present studies highlight the importance of polyamine derivatives of α-hederagenin in the discovery and development of novel anticancer agents.

In order to improve the strength and toughness of the C/C-HfC-ZrB2-SiC composites, uniformly distributed SiC nanowires were in situ grown in C/C preform using a simple precursor infiltration pyrolysis method with ferrocene as catalyst. The SiC nanowires could greatly refine the size of the ultra-high temperature ceramic (HfC-ZrB2-SiC) particles, and make the ceramic particles interconnected with the unitary body. After introducing SiC nanowires, the flexural strength, flexural modulus and fracture toughness of the composites increased by 21%, 29% and 28% respectively, due to interfacial weakening, the deflection of cracks induced by SiC nanowires and the pullout of SiC nanowires. The C/C-HfC-ZrB2-SiC composites with SiC nanowires also displayed good erosion resistance under high velocity Al 2 O 3 particle erosion.

To enhance the oxidation resistance of SiC–MoSi2–ZrB2 coating for C/C composites, pre-oxidation treatment and chemical vapor deposition were applied to construct a SiC nanowire-toughened inlaid transition layer between C/C and SiC–MoSi2–ZrB2 coating. The results show that the coating prepared with pre-oxidation and SiC nanowires has better oxidation resistance, which can protect C/C for 124 h at 1773 K in air with the weight loss per unit area of 1.1 mg cm−2. The synergistic effect of the inlaid structure of the transition layer and SiC nanowires plays positive role on alleviating the mismatch of thermal expansion coefficient between C/C and SiC–MoSi2–ZrB2 coating.

A novel precursor infiltration and pyrolysis (PIP) technique was used to in-situ synthesize SiC nanowires (NWs) on C/C composites, and then pack cementation was applied to prepare a silicide coating. The results show that the NWs could not only grow uniformly on the C/C surface but also be synthesized in some microholes through PIP technique. During thermogravimetry tests from 800 °C to 1400 °C in simulated air, the mass loss of the coated specimen decreased from 11.8% to 1.5% after incorporating PIP-SiC NWs. The introduction of PIP-SiC NWs also increased the thermal shock resistance of the coated specimens. After 24 times thermal cycles between room temperature and 1500 °C, the final mass loss reduced from 3.23% to 0.37%. The improvement of thermal shock resistance of the coated specimens was owing to the nanoscale toughening mechanism including pulling-out, debonding and bridging of PIP-SiC NWs. In addition, NWs at the coating/substrate interface could play as a barrier to restrain the propagation of microcrack and thus decreased the size of micocrack.

In order to improve the mechanical properties of carbon/carbon (C/C) composites, homogeneous and uniform SiC nanowires were in situ grown in low-density 2.5D C/C preform using precursor infiltration pyrolysis method with ferrocene as catalyst. SiC nanowire reinforced C/C composites were obtained via chemical vapor infiltration. The linear nanowires consisted of single crystal β-phase SiC with uniform morphology of about 200 nm in diameter and 100 µm in length. Due to the effect of SiC nanowires, the size of pyrolytic carbon (PyC) grain greatly refined in the process of densification. After introducing SiC nanowires, the flexural and shear strength of the composites increased by 131% and 68%. The strength improvement was attributed to the improvement in the bonding of the fibers/PyC interface, the nanoparticles’ dispersion strengthening effect and the increased energy absorption due to the deflection of cracks, the pullout of SiC nanowires and the break of SiC/PyC microrods.