Achieving Significant Thermal Conductivity Enhancement via an Ice-Templated and Sintered BN-SiC Skeleton.

Conventional polymer composites normally suffer from undesired thermal conductivity enhancement which has hampered the development of modern electronics as they face a stricter heat dissipating requirement. It is still challenging to achieve satisfactory thermal conductivity enhancement with reasonable mechanical properties. Herein, we present a three-dimensional (3D), lightweight, and mechanically strong boron nitride (BN)-silicon carbide (SiC) skeleton with aligned thermal pathways via the combination of ice-templated assembly and high-temperature sintering. The sintering has introduced atomic-level coupling at the BN-SiC junction which contributes to efficient phonon transport via the newly formed borosilicate glass BCxN3-x (0 ≤ x ≤ 3) and SiCxN4-x (0 ≤ x ≤ 4) phases, leading to much lower interfacial thermal resistance. Thus, the obtained BN-SiC skeleton shows satisfactory thermal performance. The prepared 3D BN-SiC/polydimethylsiloxane (PDMS) composites exhibit a maximum through-plane thermal conductivity of 3.87 W·m-1·K-1 at a filler loading of only 8.35 vol %. The thermal conductivity enhancement efficiency reaches 220% per 1 vol % filler when compared to pure PDMS matrix, superior to other reported BN skeleton-based composites. The feature of our strategy is to allow the oriented three-dimensional skeleton to be strongly bonded by a sintered ceramic phase instead of polymer-like adhesive, namely, to improve the intrinsic thermal conductivity of the skeleton to the greatest extent. This strategy can be applied to develop novel thermal management materials that are lightweight and mechanically tough that rapidly transfer heat. It represents a new avenue to addressing the heat challenges in traditional electronic products.

Polycystic kidney and hepatic disease 1 gene mutations in von Meyenburg complexes: Case report.

Von Meyenburg complexes (VMCs) are a rare type of ductal plate malformation. We herein report two Chinese families with VMCs, and the suspicious gene mutation of this disease. Proband A was a 62-year-old woman with abnormal echographic presentation of the liver. She received magnetic resonance imaging (MRI) examination and liver biopsy, and the results showed she had VMCs. Histologically proved hepatocellular carcinoma was found 1 year after the diagnosis of VMCs. Proband B was a 57-year-old woman with intrahepatic diffuse lesions displayed by abdominal ultrasonography. Her final diagnoses were VMCs, congenital hepatic fibrosis, and hepatitis B surface e antigen-negative chronic hepatitis B after a series of examinations. Then, all the family members of both proband A and proband B were screened for VMCs by MRI or ultrasonography. The results showed that four of the 11 family members from two families, including two males and two females, were diagnosed with VMCs. DNA samples were extracted from the peripheral blood of those 11 individuals of two VMCs pedigrees and subjected to polymerase chain reaction amplification of the polycystic kidney and hepatic disease 1 (PKHD1) gene. Two different mutation loci were identified. Heterozygous mutations located in exon 32 (c.4280delG, p.Gly1427ValfsX6) in family A and exon 28 (c.3118C>T, p.Arg1040Ter) in family B were detected. We speculate that PKHD1 gene mutations may be responsible for the development of VMCs.

The staff and patient perspectives on compliance with mechanical prophylaxis for venous thromboembolism.

BACKGROUND: This study evaluated the accuracy of assessment and compliance with proper use of intermittent pneumatic compression (IPC) devices before and after implementation of education, accountability, and oversight measures for health care providers. METHODS: Prospective analysis of randomly selected, emergently hospitalized adult patients was performed (group 1). IPC use was observed by random visual inspections. These patients underwent independent venous thromboembolism (VTE) risk assessments by the admitting service and a VTE consult service. Mechanical prophylaxis orders were subsequently reviewed. Next, strategies to improve compliance were implemented. One year later, prospective analysis of a similar cohort (group 2) was performed, followed by surveys of staff and patients to identify barriers to compliance. RESULTS: In group 1, VTE risk assessments were accurate and IPC was appropriately ordered. Of patients who needed IPC, 24 had IPC correctly applied and 72 did not. In group 2, VTE risk assessments were accurate and IPC was appropriately ordered. Of patients who needed IPC, 26 had IPC correctly applied and 74 did not. Surveys revealed that most providers are aware of the indications, order appropriately, and make efforts to ensure application. Most nurses reported that orders were placed and that IPC was applied. Most patients claimed to have knowledge of VTE and IPC use, but half reported that they were not educated and complained of sleep interference. CONCLUSIONS: Even with implementation of strategies to improve compliance, most patients do not receive adequate mechanical prophylaxis. Health care providers appropriately order prophylactic measures but do not follow up to ensure application. Discomfort and lack of education of the patient were important barriers to prophylaxis.