Crack growth in Westerly granite during a cyclic loading test

To examine the fatigue process of granite, cylindrical Westerly granite specimens, 10 mm in diameter and 20 mm in length, were subjected to a cyclic loading test under uniaxial compression with a maximum of 140 MPa at room temperature, and crack growth patterns within them were analyzed by microscopic observation and image analysis techniques. The fatigue process is divided into three characteristic stages; a primary stage in which the upper peak strain increases at a decelerating rate (stage I), a second stage with linearly slight increasing rate of strain following stage I (stage II), and the third and final stage in which the upper peak strain increases at an accelerating rate and culminates in specimen failure (stage III). A series of prefailure specimens, of which the stage in the fatigue process was decided by monitoring the strain behavior during the test, were retrieved. In addition, these specimens were compared with specimens stressed to close to the breaking strength by monotonic compression to examine the characteristic features of fatigue. The fluorescent method was applied to identify microcracks within the specimens. The advantage of this method is to provide quick and accurate identification of microcracks with an optical microscope. Microcracks are detected based on a marked difference in brightness under ultraviolet light irradiation because they are fully filled with acrylic resin mixed with a fluorescent substance in advance. Thin sections, including the axis of the specimen, 10 × 20 mm, were prepared for detailed observation after the pretreatment of the method. The results were as follows. At the initial degradation stage, distinguishing crack growth was identified in quartz grains. It is estimated that the slowdown of the strain growth rate at this stage was caused by the decrease in crack growth, that is, the portions with cracking potentiality were damaged at the first or early loading, and no further damage occurred immediately following the first damage. At the second stage, no significant crack growth in quartz grains was identified. On the other hand, in feldspar grains, development of cracks in a preferential direction, parallel to the loading direction, was observed. However, they did not grow into intergranular cracks by cutting across the grain boundaries during this stage. Consequently, it was found that a gradual progress of microcracks within feldspar grains was dominant during the second stage, and this is because the strain growth rate was in a steady and long state. At the final accelerated stage, many intergranular cracks running parallel to the loading direction were identified. It is obvious that these long cracks were formed mainly by the linking and growth of the intragranular cracks in feldspars, which were generated during the former stages. Their formation takes the fatigue process from the second stage to the final stage with a sharp increase in strain, and their further development seemed to lead the whole specimen to ultimate fatigue failure

Functional Outcomes after Selective Clamping in Robot-Assisted Partial Nephrectomy

This study aimed to assess the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN). We retrospectively analyzed 372 patients who had undergone RAPN at our hospital between July 2010 and March 2021. After propensity score matching between the full and selective clamping groups, perioperative outcomes and postoperative preservation ratio of the estimated glomerular filtration rate (eGFR) were compared at 6 and 12 months of follow-up. After propensity score matching, we evaluated 47 patients from each group. While no significant differences were observed in surgical time, warm ischemia time, or incidence rates of all grades of complications between the two cohorts, the estimated blood loss (EBL) was significantly lower in the full clamping group than in the selective clamping group (30 vs. 60, p = 0.046). However, no significant intergroup differences were observed in the postoperative preservation ratio of eGFR at 6 or 12 months of follow-up (full clamping 94.0% vs. selective clamping 92.7%, p = 0.509, and full clamping 92.0% vs. selective clamping 91.6%, p = 0.476, respectively). Selective clamping resulted in higher EBL rates than did full clamping in RAPN. However, selective clamping provided no renal functional advantage over full clamping in our propensity-score-matched cohort

Novel Intraoperative Navigation Using Ultra-High-Resolution CT in Robot-Assisted Partial Nephrectomy

To assess the perioperative and short-term functional outcomes of robot-assisted partial nephrectomy (RAPN) with intraoperative navigation using an ultra-high-resolution computed tomography (UHR-CT) scanner, we retrospectively analyzed 323 patients who underwent RAPN using an UHR-CT or area-detector CT (ADCT). Perioperative outcomes and the postoperative preservation ratio of estimated glomerular filtration rate (eGFR) were compared. After the propensity score matching, we evaluated 99 patients in each group. Although the median warm ischemia time (WIT) was less than 25 min in both groups, it was significantly shorter in the UHR-CT group than in the ADCT group (15 min vs. 17 min, p = 0.032). Moreover, the estimated blood loss (EBL) was significantly lower in the UHR-CT group than in the ADCT group (33 mL vs. 50 mL, p = 0.028). However, there were no significant intergroup differences in the postoperative preservation ratio of eGFR at 3 or 6 months of follow-up (ADCT 91.8% vs. UHR-CT 93.5%, p = 0.195; and ADCT 91.7% vs. UHR-CT 94.0%, p = 0.160, respectively). Although no differences in short-term renal function were observed in intraoperative navigation for RAPN in this propensity score–matched cohort, this study is the first to demonstrate that UHR-CT resulted in a shorter WIT and lower EBL than ADCT

Novel Intraoperative Navigation Using Ultra-High-Resolution CT in Robot-Assisted Partial Nephrectomy

To assess the perioperative and short-term functional outcomes of robot-assisted partial nephrectomy (RAPN) with intraoperative navigation using an ultra-high-resolution computed tomography (UHR-CT) scanner, we retrospectively analyzed 323 patients who underwent RAPN using an UHR-CT or area-detector CT (ADCT). Perioperative outcomes and the postoperative preservation ratio of estimated glomerular filtration rate (eGFR) were compared. After the propensity score matching, we evaluated 99 patients in each group. Although the median warm ischemia time (WIT) was less than 25 min in both groups, it was significantly shorter in the UHR-CT group than in the ADCT group (15 min vs. 17 min, p = 0.032). Moreover, the estimated blood loss (EBL) was significantly lower in the UHR-CT group than in the ADCT group (33 mL vs. 50 mL, p = 0.028). However, there were no significant intergroup differences in the postoperative preservation ratio of eGFR at 3 or 6 months of follow-up (ADCT 91.8% vs. UHR-CT 93.5%, p = 0.195; and ADCT 91.7% vs. UHR-CT 94.0%, p = 0.160, respectively). Although no differences in short-term renal function were observed in intraoperative navigation for RAPN in this propensity score–matched cohort, this study is the first to demonstrate that UHR-CT resulted in a shorter WIT and lower EBL than ADCT

Alanine-Serine-Cysteine Transporter 2 Inhibition Suppresses Prostate Cancer Cell Growth In Vitro

Alanine-serine-cysteine transporter 2 (ASCT2) has been associated with increased levels of metabolism in various malignant tumors. However, its biological significance in the proliferation of prostate cancer (PCa) cells remains under investigation. We used the cBioPortal database to assess the effect of ASCT2 expression on the oncological outcomes of 108 PCa patients. To evaluate the function of ASCT2 in castration-sensitive PCa (CSPC) and castration-resistant PCa (CRPC), LNCaP cells and the ARV7-positive PCa cell line, 22Rv1, were assessed using cell proliferation assays and Western blot analyses. The ASCT2 expression level was associated with biochemical recurrence-free survival after prostatectomy in patients with a Gleason score ≥ 7. In vitro experiments indicated that the growth of LNCaP cells after combination therapy of ASCT2 siRNA and enzalutamide treatment was significantly reduced, compared to that following treatment with enzalutamide alone or ASCT2 siRNA transfection alone (p p < 0.01, 0.01, respectively). We demonstrated that ASCT2 inhibition significantly reduced the proliferation rates of both CSPC and CRPC cells in vitro