Corrosion resistance of selective laser melted Ti-6Al-4V was investigated. • XY-plane of Selective laser melted alloy shows a better corrosion resistance. • More α' and less β-Ti weaken the corrosion resistance of XZ-plane.

Analysis of the damage initiation in a SiC/SiC composite tube from a direct comparison between large-scale numerical simulation and synchrotron X-ray micro-computed tomography. AbstractDamage initiation is an important issue to understand the mechanical behavior of ceramic matrix composites. In the present work, a braided SiC/SiC composite tube was studied by FFT simulation tightly linked with micro-computed tomography (µCT) observations performed during an in situ uniaxial tensile test, which provide both the real microstructure, with a good description of local microstructural geometries, and location of cracks at the onset of damage. The FFT method was proven applicable to tubular structures and efficient to complete the large-scale simulation on a full resolution µCT scan (~6.7 billion voxels) within a short time. The edge effect due to the numerical periodic boundary conditions prescribed on the real and not rigorously periodic microstructure was quantified. The obtained stress field was compared to the cracks detected by the in situ µCT observations of the same composite tube. This one-to-one comparison showed that cracks preferentially initiated at tow interfaces, where sharp edges of macropores are mostly located and generate stress concentrations.

Ti-6Al-4V alloy produced by selective laser melting (SLM) was reported to exhibit an inferior corrosion resistance compared with the traditionally processed Grade 5 alloy, due to the formation of high-energy metastable α′ martensite with regard to α martensite. This work manipulates the transformation of α′ martensite to α martensite by heat-treatment in SLM-produced Ti-6Al-4V alloy and studies the effect on its corrosion behavior using electrochemical tests and microstructural analysis. The electrochemical results reveal that the heat-treated SLM-produced samples exhibit a higher corrosion rate than the as-received counterparts. The microstructural characterization results show that the acicular α′ martensite vanishes gradually, and a plate-shaped α phase and a lamellar α + β mixture continuously form with enhancing heat-treatment temperature, which increases the grain size. The relation between changes in grain size and corrosion resistance of SLM-produced Ti-6Al-4V has been discussed in detail

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Our findings demonstrate that EMT contributed to enrichment of ovarian CSCs in vitro, making EMT targeting in epithelial ovarian cancer a novel therapeutic option.

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The purpose of this study was to examine metastasis in different nodal stations and the extent of lymphadenectomy for esophageal carcinoma. Eighty-seven thoracic esophageal squamous carcinoma patients underwent esophagectomy with two-field or three-field lymphadenectomy based on cervical ultrasonography. Thirty-five patients (40.2%) with ultrasonography-detected cervical nodes underwent cervical dissection. Significantly more patients with primary tumors in the upper thoracic esophagus had cervical dissection than patients with tumors in the middle and lower esophagus (66.7%vs. 30.2%, P=0.002). Metastasis to cervical, superior mediastinal, mid-mediastinal, and abdominal nodes were 19.5%, 25.3%, 23%, and 24.1%, respectively. Cervical metastasis was 29.2%, 20.8%, and 10% for upper, middle, and lower thoracic esophageal tumors. Regional lymphadenopathy was found in 48 patients (55.2%) and was significantly related to cervical metastasis (31.3%vs. 5.1%, P=0.002). It was significantly less in upper (37.5%) than in middle (62.3%) and lower (60%) thoracic esophageal tumors (P=0.041). When cervical metastasis was included into regional lymphadenopathy, the difference was no longer significant (45.8%vs. 63.5%, P=0.135). Cervical dissection was associated with significantly more morbidities (60%vs. 34.6%, P=0.020), especially recurrent laryngeal nerve palsy (22.9%vs. 9.6%, P=0.089). Recurrent laryngeal nerve palsy was related significantly to anastomotic leakage (53.8%vs. 13.5%, P=0.001). There was no significant difference between the 2-year survivals for patients with or without cervical metastasis (50.0 vs. 72.0%, P=0.094). We conclude that cervical metastasis is of a similar rate as metastasis to mediastinal or abdominal nodes. Cervical nodes should be taken as regional lymph nodes for thoracic esophageal cancer. Cervical dissection is associated with increased morbidity and should be reserved for patients who may benefit from the procedure. Selective three-field dissection based on ultrasonography is helpful in reducing surgical morbidity while increasing the completeness of resection.

Distinct corrosion behavior was reported in multiphased titanium alloys prepared by additive manufacturing and by traditional technologies because of different phase constituents formed during processing. An open question is therefore raised: is there always different corrosion behavior of materials prepared by different methods? This work reports resemble corrosion behavior of selective laser melted and wrought single β-phase Ti-24Nb-4Zr-8Sn (Ti2448) in both NaCl solution and Hank’s solution. The electrochemical measurements showed that both samples have close calculated polarization resistance and corrosion potential in NaCl solution, i.e., 4.99 ± 0.63 MΩ cm2 and −0.26 ± 0.01 V for the selective laser-melted Ti2448, and 4.42 ± 0.71 MΩ cm2 and −0.25 ± 0.01 V for the wrought Ti2448, respectively. Both samples reveal the same variation in weight change after 180-day immersion test in Hank’s solution. Such resemblance in corrosion behavior without pitting morphologies is attributed to the formation of monolithic β-phase during processing, which demonstrates that titanium alloys with single phase show comparable corrosion behavior regardless of the manufacturing methods adopted.