No abstract

Glioma is the most frequent form of malignant brain tumors. Surgical debulking is a major strategy for glioma treatment. However, there is a great challenge for the neurosurgeons to intraoperatively identify the true margins of glioma because of its infiltrative nature. Tumor residues or microscopic satellite foci left in the resection bed are the main reasons leading to early recurrence as well as poor prognosis. In this study, a surface-enhanced resonance Raman scattering (SERRS) probe was developed to intraoperatively guide glioma resection. In this probe, molecular reporters with absorptive maxima at the near-infrared wavelength range were covalently functionalized on the surface of gold nanostars. This SERRS probe demonstrated an ultrahigh sensitivity with a detection limit of 5.0 pM in aqueous solution. By the development of glioma xenografts in a mouse dorsal skin window chamber, extravasation of this probe from leaky tumor vasculature as functions of time and distance to tumor boundary was investigated. Importantly, the invasive margin of the tumor xenograft was demarcated by this probe with a high signal-to-background ratio. Preoperative magnetic resonance imaging (MRI) first defined the position of orthotopic glioma xenografts in the brain of rat models, and the craniotomy plan was designed. The brain tumor was then excised intraoperatively step-by-step with the assistance of a handheld Raman scanner till the Raman signals of the probe completely disappeared in the resection bed. Notably, longitudinal MRI showed that SERRS-guided surgery significantly reduced the tumor recurrence rate and improved the overall survival of rat models compared with the white light-guided surgery. Overall, this work demonstrates the prognostic benefit of SERRS-guided glioma surgery in animal models. Because delineation of tumor-invasive margins is a common challenge faced by the surgeons, this SERRS probe with a picomolar detection limit holds the promise in improving the surgical outcome of different types of infiltrated tumors.

No abstract

Under the shallow coal mining condition and based on the cracking and movement rules of the roof in different mining stages, the mechanical models of symmetrical pressure-arch, stepped pressure-arch, rotating-squeezed pressure-arch in the mining field were established. Then, the instability criterion of each pressure-arch structure was derived. Through the similarity material experiment and numerical simulation, the evolution characteristics of the composite pressure-arches in the near- and far-field were revealed. Results show that the stepped pressure-arch in broken blocks of the basic roof was formed when the horizontal principal stress was greater than the in-situ stress. The broken blocks’ sliding could induce roof cutting off and strong weighting load. The structural characteristics of the overlying strata were determined by the thickness of the bedrock. The upper broken rocks formed a symmetrical pressure-arch in the near- and a far-field pressure-arch formed in the mining field. The median periodic broken rocks formed the rotating-squeezed pressure-arch, bearing the load of the loose layers and protecting the mining panel. After all bedrocks breaking, the latter arch foot of the far-field pressure-arch was transferred to the compacted caving zone. This study can provide a theoretical reference for the similar mining engineering.

No abstract

The inert C(sp 3)–H bond and easy overoxidation of toluene make the selective oxidation of toluene to benzaldehyde a great challenge. Herein, we present that a photocatalyst, constructed with a small amount (1 mol %) of amorphous BiOCl nanosheets assembled on TiO2 (denoted as 0.01BOC/TiO2), shows excellent performance in toluene oxidation to benzaldehyde, with 85% selectivity at 10% conversion, and the benzaldehyde formation rate is up to 1.7 mmol g–1 h–1, which is 5.6 and 3.7 times that of bare TiO2 and BOC, respectively. In addition to the charge separation function of the BOC/TiO2 heterojunction, we found that the amorphous structure of BOC endows its abundant surface oxygen vacancies (Ov), which can further promote the charge separation. Most importantly, the surface Ov of amorphous BOC can efficiently adsorb and activate O2, and amorphous BOC makes the product, benzaldehyde, easily desorb from the catalyst surface, which alleviates the further oxidation of benzaldehyde, and results in the high selectivity. This work highlights the importance of the microstructure based on heterojunctions, which is conducive to the rational design of photocatalysts with high performance in organic synthesis.

A novel copper and carbon co-modified TiO2 photocatalyst (TiO2–Cu/C) was prepared using a simple sol–gel method.

Duck hepatitis A virus 3 (DHAV-3), the only member of the novel genus Avihepatovirus, in the family Picornaviridae, can cause significant economic losses for duck farms in China. Reports on the pathogenicity and the antiviral molecular mechanisms of the lethal DHAV-3 strain in ducklings are inadequate and remain poorly understood. We conducted global gene expression profiling and screened differentially expressed genes (DEG) of duckling liver tissues infected with lethal DHAV-3. There were 1643 DEG and 8979 DEG when compared with mock ducklings at 12 hours post-infection (hpi) and at 48 hpi, respectively. Gene pathway analysis of DEG highlighted mainly biological processes involved in metabolic pathways, host immune responses, and viral invasion. The results may provide valuable information for us to explore the pathogenicity of the virulent DHAV-3 strain and to improve our understanding of host–virus interactions.Electronic supplementary materialThe online version of this article (10.1186/s13567-018-0545-7) contains supplementary material, which is available to authorized users.