The Role of Al4C3 Morphology in Tensile Properties of Carbon Fiber Reinforced 2024 Aluminum Alloy during Thermal Exposure.

The aluminum alloy drill pipe suffers long-term high-temperature conditions during ultra-deep well drilling. In this paper, the samples were prepared by vacuum hot pressing, followed by hot extrusion and T6 heat treatment. The mechanical properties of short carbon fiber reinforced 2024 aluminum alloy composites (SCFs/2024 Al) and the microstructure evolution at the interface region thermal exposure at 160 °C for 500 h are discussed. The experimental results showed that the effect of short carbon fiber on 2024 aluminum alloy remained steady throughout the whole process of the heat exposure experiment. The distribution and volume of interface products (Al4C3) changed with the prolonging of heat exposure time, and connected after coarsening. The evolution of the morphology of Al4C3 relieved the stress of the interface between carbon fiber and aluminum alloy matrix and enhanced the mechanical properties of the composite.

Choriocarcinoma in a viable pregnancy with the rare presentation of intractable lower back pain.

OBJECTIVE: We present a case of choriocarcinoma in a viable pregnancy with the rare presentation of intractable lower back pain. CASE REPORT: The patient is a 34-year-old multiparous woman with her second pregnancy, and a history of scoliosis with spinal fixation. Her first pregnancy was uneventful, with a term vaginal delivery. She was hospitalized four times due to intractable back pain from 25 to 31 weeks, and terminated at 31 weeks. The placenta was unremarkable on gross examination. Postpartum, the patient developed obstructive ileus, requiring a rectosigmoid resection. She was diagnosed with metastatic choriocarcinoma to the liver, para-aortic lymph nodes, and mesentery. A week later, she developed micro-thrombosis of all limbs, massive ascites, pleural effusion. Patient refused chemotherapy and died on post-operative Day 15. CONCLUSION: Presentation of choriocarcinoma in pregnancy varies widely. Clinicians should consider the differential diagnosis of choriocarcinoma when faced with abnormal unexplained symptoms during pregnancy.

The effect of electron beam irradiation on WS2 nanotubes.

WS(2) nanotubes were irradiated with a focused electron beam in an electron microscope. The results show that the nanotubes are destroyed from the outer layer to the inside. The displaced atoms can leave the irradiated area by sputtering events or by diffusive migration along the shells and the inner hollow. The smaller tubes have a lower stability. The stability of the tube increases after the central hollow is closed and the asymmetric irradiation can lead to a bending of the tube. Electron irradiation causes the change of WS(2) nanotubes into a polycrystalline structure. The primary cause of the electron irradiation damage in WS(2) nanotubes is knock-on collisions.

Combined prenatal ultrasound and magnetic resonance imaging in an extensive congenital fibrosarcoma: a case report and review of the literature.

OBJECTIVE: Tumors of congenital origin differ in their symptoms and signs, predominant location and prognosis from those occurred later in childhood. To determine whether the prognosis of congenital (infantile) fibrosarcoma in the retroperitoneum, an extremely rare form of soft tissue malignant tumor, can be assessed prenatally. METHODS: We describe a case of this condition diagnosed in utero, including the assessment of the tumor behavior by ultrasound and magnetic resonance imaging. We also review the English language literature in Medline over the past 10 years and describe the management options available in such cases. RESULTS: Our case had precise prenatal findings revealed unfavorable conditions such as bulky tumor mass, spinal metastasis and pulmonary hypoplasia. CONCLUSION: Fetal imaging studies could accurately identify the invasion of tumor. The outcome is usually poor, especially for those fetuses affected by an axial location of the tumor.