This study employs direct numerical simulations to examine the effects of varying backpressure conditions on the turbulent atomisation of impinging liquid jets. Using the incompressible Navier–Stokes equations, and a volume-of-fluid approach enhanced by adaptive mesh refinement and an isoface-based interface reconstruction algorithm, we analyse spray characteristics in the environments with ambient gas densities ranging from 1 to 40 times the atmospheric pressure under five different backpressure scenarios. We investigate the behaviour of turbulent jets, incorporate realistic orifice geometries and identify significant variations in the atomisation patterns depending on backpressure. Two distinct atomisation types emerge, namely jet-sheet-ligament-droplet at lower backpressures and jet-sheet-fragment-droplet at higher ones, alongside a transition from dilute to dense spray patterns. This variation affects the droplet size distribution and spray dynamics, with increased backpressure reducing the spray's spreading angle and breakup length, while increasing the droplet size variation. Furthermore, these conditions promote distributions that induce rapid, nonlinear wavy motion in liquid sheets. Topological analysis of the atomisation field using velocity-gradient tensor invariants reveals significant variations in topology volume fractions across different regions. Downstream, the droplet Sauter mean diameter increases and then stabilises, reflecting the continuous breakup and coalescence processes, notably under higher backpressures. This research underscores the substantial impact of backpressure on impinging-jet atomisation and provides essential insights for nozzle design to optimise droplet distributions.

Shifts in the maternal gut microbiota have been implicated in the development of gestational diabetes mellitus (GDM). Understanding the interaction between gut microbiota and host glucose metabolism will provide a new target of prediction and treatment. In this nested case-control study, we aimed to investigate the causal effects of gut microbiota from GDM patients on the glucose metabolism of germ-free (GF) mice. Stool and peripheral blood samples, as well as clinical information, were collected from 45 GDM patients and 45 healthy controls (matched by age and prepregnancy body mass index (BMI)) in the first and second trimester. Gut microbiota profiles were explored by next-generation sequencing of the 16S rRNA gene, and inflammatory factors in peripheral blood were analyzed by enzyme-linked immunosorbent assay. Fecal samples from GDM and non-GDM donors were transferred to GF mice. The gut microbiota of women with GDM showed reduced richness, specifically decreased Bacteroides and Akkermansia, as well as increased Faecalibacterium. The relative abundance of Akkermansia was negatively associated with blood glucose levels, and the relative abundance of Faecalibacterium was positively related to inflammatory factor concentrations. The transfer of fecal microbiota from GDM and non-GDM donors to GF mice resulted in different gut microbiota colonization patterns, and hyperglycemia was induced in mice that received GDM donor microbiota. These results suggested that the shifting pattern of gut microbiota in GDM patients contributed to disease pathogenesis.

We present the case of a 2-year-old boy with progressive left-sided weakness and a cranial magnetic resonance imaging (MRI) scan showing a lesion with a cystic component in the right thalamus and basal ganglia. The lesion was subtotally resected and diagnosed as a pilocytic astrocytoma by histopathology. Tumor seeding along the surgical tract was seen on MRI 16 days and 10 weeks after surgery. The patient received vincristine and carboplatin, and MRI performed 4 months after chemotherapy revealed no additional or residual lesions. This case illustrated that a World Health Organization grade I astrocytoma could disseminate along the surgical tract.

A method to design the composite insulation structures in pulsed power systems is proposed in this paper. The theoretical bases for this method include the Weibull statistical distribution and the empirical insulation formula. A uniform formula to describe the reliability (R) for different insulation media such as solid, liquid, gas, vacuum, and vacuum surface is derived. The dependence curves of the normalized applied field on R are also obtained. These curves show that the normalized applied field decreases rapidly as R increases but the declining rates corresponding to different insulation media are different. In addition, if R is required to be higher than a given level, the normalized applied field should be smaller than a certain value. In practical design, the common range of the applied fields for different insulation media should be chosen to meet a global reliability requirement. In the end, the proposed method is demonstrated with a specific coaxial high-voltage vacuum insulator.

A useful procedure is described to rapidly obtain Bragg-reflection intensities from the FULLPROF suite, and the Bragg intensities can then be input into the GEST and the PECKCRYST programs for crystal-structure determination of small molecules. An example on using the new procedure for the structure determination from powder diffraction determination of hydrochlorothiazide (C7H8ClN3O4S2) is presented, and the powder-structure results obtained by the PECKCRYST program are in good agreement with previously reported single-crystal results.

Schwannoma arising from the tympanic membrane is a rare neoplasm. This report describes an external ear canal mass obscuring the tympanic membrane. A transcanal approach identified a tumour adhered to the tympanic membrane. The tumour was excised without myringoplasty. Pathology confirmed the diagnosis of schwannoma. Clinical examination revealed no evidence of recurrence during a follow-up period of one year. The possible origins of schwannoma of the tympanic membrane and lesion management are also discussed.

Salivary duct carcinoma is a rare and invasive malignant tumour with rapid distant metastasis and dismal prognosis. Clinically, perineural invasion of the salivary duct carcinoma is commonly noted. Here, we present a case of salivary duct carcinoma of submandibular gland origin with perineural invasion of the trigeminal nerve proximal to the intracranium, that was well demonstrated by a magnetic resonance image (MRI) and was consistent with the clinical presentation. This case received radical resection and radiotherapy with inclusion of the skull base within the field. There was no tumour recurrence and distant metastasis 24 months post-operatively.

Pure vapor-grown carbon nanofibers (VGCNF's) with controllable diameters of 10–200 nm were prepared by an improved floating catalyst method. Through transmission electron microscopy (TEM) observation, it was found that VGCNF's have a duplex structure, a hollow and high-crystallinity graphite filament called primary carbon fiber surrounded by a pyrocarbon layer with low graphite crystallinity. It was observed using high-resolution TEM that VGCNF's have excellent graphitic crystallinity with graphite layers stacked neatly parallel to fiber axis. Moreover, x-ray diffraction results showed that the graphitic crystallinity of carbon fibers became higher with decreasing diameter of carbon fibers.

We present preliminary results of two monitoring projects on AGNs and BL Lacs with four intermediate-band optical filters at Lick Observatory, South African Astronomical Observatory, and Siding Spring Observatory. We applied differential photometry between the target and non-variable field stars to derive the variability amplitudes. All the AGNs varied in all wavebands, with amplitudes from 30% to 90%. The variations in shorter wavelength filters are always larger than in longer wavelength filters. We did not observe significant continuum slope changes. Continuum variations of BL Lacs up to 0.2 mag in 20 minutes were observed. Interestingly, we found a time lag of 6–8 minutes between two seemingly correlated variations observed in the intermediate U band with the 1-m telescope and in broad V band with the 24-in. telescope at SSO.