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Polymer-based dielectric films with desirable heat dissipation property hold great promise as thermal management materials in advanced electronics and high power devices. Herein, we report a new strategy for preparing thermally conductive films by synergistically combining one-dimensional (1D) aramid nanofiber (ANF) with 2D edge-hydroxylated boron nitride nanosheet (OH-BNNS) via a vacuum-assisted self-assembly technique. The obtained ANF/OH-BNNS film exhibits an ultrahigh in-plane thermal conductivity of 32.3 W m−1K−1 at 40 wt% BNNS-OH loading, which is 3530% greater than that of the pure ANF film. The excellent thermal conductivity results from the special 'brick-and-mortar' layered structure of ANF/OH-BNNS, in which the increased contacting and overlapping of OH-BNNS promotes the formation of the thermal conduction pathways. In addition, the rigid ANFs act as bridges linking OH-BNNS by favorable hydrogen bonding interactions, which efficiently enhance phonon propagation and stress transfer in the film. Moreover, the ANF/OH-BNNS film simultaneously shows low dielectric loss (~0.03), high tensile strength (~88 MPa), and a high decomposition temperature (>510 °C). We believe that these findings are of great importance for the fabrication and practical application of thermal management materials in high-temperature electronics and devices. [ABSTRACT FROM AUTHOR]

The diagenetic mineral assemblages in mudstones during diagenesis can indicate the changing diagenetic environmental characteristics, providing possibility to study the influence of the diagenetic environment on the evolution of organic matter (OM). In the present study, mudstones from the Dongying Depression were selected and evaluated by X-ray diffraction (XRD), thin section, and scanning electron microscopy (SEM). The SEM and XRD results indicated that detrital minerals are depositional minerals, whereas clay minerals are diagenetic minerals; carbonate are a combination of depositional and diagenetic minerals. According to the diagenetic mineral content and content change rates, three diagenetic mineral assemblages were distinguished: I. smectite/I-S (1,000-2,000 m); II. Smectite/I-S + illite + kaolinite (2,000-3,000 m); III. Smectite/I-S + illite + chlorite + ankerite (>3,000 m). Kaolinite is formed in acidic environments, while the other diagenetic minerals are formed and stable under alkaline conditions. Therefore, the evolution of the diagenetic environment was investigated using the K/(I + Ch + A) ratio (K:Kaolinite; I:Illite; Ch:Chlorite; A:Ankerite), and the formations were found to have undergone alkaline-acidic-alkaline changes. For OM with different chemical properties, huge differences exist in hydrocarbon generation between acidic and alkaline diagenetic environments. Therefore, for hydrocarbon generation, attention should be paid to the changes in diagenetic environment, which are important for understanding the hydrocarbon generation, hydrocarbon expulsion and hydrocarbon accumulation in mudstones. [ABSTRACT FROM AUTHOR]

Mechanical metamaterials have attracted tremendous interests, owing to their fruitfulness of underlying physics and mechanics as well as diverse potential applications. Conventional soft mechanical metamaterials contain periodic distribution of holes having identical sizes, which can only display one mechanical function. Periodically dispersing a regular pattern of through-holes with two sizes into an elastomer results in metamaterials with more mechanical functions and deformation scenarios. We numerically investigate the deformation behaviors of this type of metamaterials. Switching of modes from the buckling-dominated deformation to a loss-of-instability deformation is emphasized. Replacing the pattern of holes with the same sizes by a pattern of holes with two sizes imposes higher compliance and even loss of negative Poisson’s ratio of the material. [ABSTRACT FROM AUTHOR]

Mitochondrial energy metabolism disorder is one of the important reasons of leukodystrophy. Mutations of mitochondrial complex I genes have been implicated in more common neurological disorders such as Leigh syndrome. We describe a case of a child manifested as regression of mental and motor development, aggravated obviously after suffering infection. Physical and auxiliary examinations demonstrated that a series of changes including white matter lesions of magnetic resonance imaging, peripheral neuropathy with high muscle tension and hyperreflexia of limbs pointed to the diagnosis of leukodystrophy, with what can’t explain the high levels of lactate and creatine kinase. Spontaneously, genetic analysis covered known leukodystrophy and mitochondrial genes were adapted for this child and his parents. Results showed the child was compound heterozygous mutation (c.278A > G; c.247G > A) within exon 2 in the NDUFAF1 gene, his parents carried a heterozygous mutation each. The authors report a case of leukodystrophy associated with mitochondrial complex I deficiency due to a novel mutation in the NDUFAF1 gene. This is the first report that NDUFAF1 mutations cause leukodystrophy. [ABSTRACT FROM AUTHOR]

Conclusions: Endoscopic resection of nasopharyngeal angiofibroma is less traumatic, causes less bleeding, and provides a good curative effect. Using pre-operative embolization and controlled hypotension, reasonable surgical strategies and techniques lead to successful resection tumors of a maximum Andrews-Fisch classification stage of III. Objective: To investigate surgical indications, methods, surgical technique, and curative effects of transnasal endoscopic resection of nasopharyngeal angiofibroma, this study evaluated factors that improve diagnosis and treatment, prevent large intra-operative blood loss and residual tumor, and increase the cure rate. Methods: A retrospective analysis was performed of the clinical data and treatment programs of 23 patients with nasopharyngeal angiofibroma who underwent endoscopic resection with pre-operative embolization and controlled hypotension. The surgical method applied was based on the size of tumor and extent of invasion. Curative effects were observed. Results: No intra-operative or perioperative complications were observed in 22 patients. Upon removal of nasal packing material 3–7 days post-operatively, one patient experienced heavy bleeding of the nasopharyngeal wound, which was treated compression hemostasis using post-nasal packing. Twenty-three patients were followed up for 6–60 months. Twenty-two patients experienced cure; one patient experienced recurrence 10 months post-operatively, and repeat nasal endoscopic surgery was performed and resulted in cure. [ABSTRACT FROM AUTHOR]

Reduction of childhood mortality is a worldwide health priority. By investigating the most frequent causes of childhood death and analyzing the major causes of misdiagnosis, this study aims to quantify the value of autopsy and guide further research for improving health services. A total of 240 autopsied cases were recruited into the study. The major causes of death according to the system were respiratory diseases, followed by neoplasms and infectious diseases, while the top three causes of death according to diseases were lobular pneumonia, septicemia, and malignant histiocytosis. Agreement between pathologic and clinical diagnoses was shown in 169 autopsies (70.5%%), and the other 71 cases (29.6%%) had been misdiagnosed. This study demonstrated the value of the routine autopsy by documenting the high rate of disagreement between clinical and autopsy diagnoses. However, the role of routine autopsy for determining in-born errors of metabolism is limited. [ABSTRACT FROM AUTHOR]