421 research outputs found
Size distributions of atmospheric particulate matter and associated trace metals in the multi-industrial city of Ulsan, Korea
Particulate matter (PM) was collected using micro-orifice uniform deposit impactors from a residential (RES) site and an industrial (IND) site in Ulsan, South Korea, in September-October 2014. The PM samples were measured based on their size distributions (11 stages), ranging from 0.06 ??m to over 18.0 ??m. Nine trace metals (As, Se, Cr, V, Cd, Pb, Ba, Sb, and Zn) associated with PM were analyzed. The PM samples exhibited weak bimodal distributions irrespective of sampling sites and events, and the mean concentrations of total PM (TPM) measured at the IND site (56.7 ??g/m3) was higher than that measured at the RES site (38.2 ??g/m3). The IND site also showed higher levels of nine trace metals, reflecting the influence of industrial activities and traffic emissions. At both sites, four trace metals (Ba, Zn, V, and Cr) contributed to over 80% of the total concentrations in TPM. The modality of individual trace metals was not strong except for Zn; however, the nine trace metals in PM2.5 and PM10 accounted for approximately 50% and 90% of the total concentrations in TPM, respectively. This result indicates that the size distributions of PM and trace metals are important to understand how respirable PM affects public health
Low-Energy Electron Scattering from c-C4F8
Electron collision cross-sections of c-C4F8 were investigated at low energies by using the R-matrix method. The static exchange (SE), static exchange with polarization (SEP), and close-coupling (CC) models of the R-matrix method were used for the calculation of the scattering cross-section. The shape resonance was detected with all the models at around 3~4 eV, and a Feshbach resonance was detected with the SEP model at 7.73 eV, in good agreement with the previous theoretical calculation. The resonance detected was also associated with the experimental dissociative electron attachment of c-C4F8, which displayed the resonances at the same energy range. The cross-sections calculated are important for plasma modeling and applications
Dependence of GCRs influx on the Solar North-South Asymmetry
We investigate the dependence of the amount of the observed galactic cosmic
ray (GCR) influx on the solar North-South asymmetry using the neutron count
rates obtained from four stations and sunspot data in archives spanning six
solar cycles from 1953 to 2008. We find that the observed GCR influxes at
Moscow, Kiel, Climax and Huancayo stations are more suppressed when the solar
activity in the southern hemisphere is dominant compared with when the solar
activity in the northern hemisphere is dominant. Its reduction rates at four
stations are all larger than those of the suppression due to other factors
including the solar polarity effect on the GCR influx. We perform the student's
t-test to see how significant these suppressions are. It is found that
suppressions due to the solar North-South asymmetry as well as the solar
polarity are significant and yet the suppressions associated with the former
are larger and more significant.Comment: 17 pages, 3figures, accepted to JAST
Outcomes of endovascular treatment for aortic pseudoaneurysm in Behcet's disease
ObjectiveTo evaluate the effectiveness of endovascular stent grafting for surgical management of aortic pseudoaneurysm in patients with Behcet's disease (BD).MethodsWe present a single-institution retrospective cohort of patients with aortic pseudoaneurysm and BD treated with aortic stent grafting. Computed tomography imaging was obtained preoperatively in all patients and once within 2 weeks postoperatively, and then annually. Clinical follow-up and erythrocyte sedimentation rate were used to follow BD activity. Immunosuppressant therapy was instituted prior to endovascular treatment unless a contraindication existed.ResultsFrom 1998 to 2012, 10 patients (eight male, two female; median age, 39) with BD and aortic pseudoaneurysm were treated with endovascular stent grafting at this institution. Ninety percent of these patients received immunosuppressive therapy before and after surgical treatment. The median follow-up period was 57 months (interquartile range, 43-72). The locations of the 12 pseudoaneurysms treated in this cohort were infrarenal abdominal aorta (seven), descending thoracic aorta (four), and aortic arch (one). Median pseudoaneurysm size was 4.5 cm (interquartile range, 3.4-5.9). At long-term follow-up, complete resolution of the aortic pseudoaneurysm was noted in all patients. No endoleaks occurred. Newly developed pseudoaneurysm at the distal margin of the stent graft was noted in one patient 17 months after the stent graft procedure. One patient required a subsequent stent graft placement for an expanding pseudoaneurysm of the subclavian artery. No patient deaths occurred during the follow-up period.ConclusionsEndovascular treatment of aortic pseudoaneurysm with stent-grafting in patients with BD is safe and effective with long-term durability
Analysis of different tumor volume thresholds of insignificant prostate cancer and their implications for active surveillance patient selection and monitoring
PurposeWe compared oncological outcomes according to tumor volume (TV) thresholds defining both classical and updated insignificant prostate cancer (IPC), since the TV threshold can be used as clinical parameter for active surveillance.MethodsBetween 2001 and 2012, we retrospectively analyzed 331 organ-confined prostate cancer patients who had preoperative Gleason score 6, preoperative PSA under 10 ng/mL and pathologic TV less than 1.3 mL. Among them, 81 of 331 (24.5%) had Gleason grade 4/5 disease postoperatively. Patients were stratified into two groups: (1) TV less than 0.5 mL, using the classical definition; and (2) TV between 0.5 mL and 1.3 mL, using the range of updated definition. We compared biochemical recurrence (BCR)-free survival and identified independent predictors of BCR in each group.ResultsGroup 2 had more Gleason grade 4/5 disease than group 1 (P<0.001). On multivariate analysis, Gleason grade 4/5 disease was not associated with BCR in group 1 (P=0.132). However, it was an independent predictor for BCR in group 2 (P=0.042). BCR-free survival were not significantly different according to the presence of Gleason grade 4/5 disease in group 1 (P=0.115). However, in group 2, it was significantly different according to the presence of Gleason grade 4/5 disease (P=0.041).ConclusionsAlthough the TV thresholds of the two definitions of IPC vary only slightly, this difference was enough to result in different clinical course if Gleason grade 4/5 disease was present. Therefore, the updated IPC TV threshold should be carefully applied as clinical parameter for active surveillance
Antifungal and antiaflatoxigenic methylenedioxy-containing compounds and piperine-like synthetic compounds
Twelve methylenedioxy-containing compounds including piperine and 10 piperine-like synthetic compounds were assessed to determine their antifungal and antiaflatoxigenic activities against Aspergillus flavus ATCC 22546 in terms of their structure-activity relationships. Piperonal and 1,3-benzodioxole had inhibitory effects against A. flavus mycelial growth and aflatoxin B1 production up to a concentration of 1000 mu g/mL. Ten piperine-like synthetic compounds were synthesized that differed in terms of the carbon length in the hydrocarbon backbone and the presence of the methylenedioxy moiety. In particular, 1-(2-methylpiperidin-1-yl)-3-phenylprop-2-en-1-one had potent antifungal and antiaflatoxigenic effects against A. flavus up to a concentration of 1 mu g/mL. This synthetic compound was remarkable because the positive control thiabendazole had no inhibitory effect at this concentration. Reverse transcription-PCR analysis showed that five genes involved in aflatoxin biosynthesis pathways were down-regulated in A. flavus, i.e., aflD, aflK, aflQ, aflR, and aflS; therefore, the synthetic compound inhibited aflatoxin production by down-regulating these genes.ope
Recent Changes in the Clinicopathologic Features of Korean Men with Prostate Cancer: A Comparison with Western Populations
Purpose : The aim of this study was to evaluate the recent changes in the clinicopathologic features of prostate cancer in Korea and to compare these features with those of Western populations.
Materials and methods : We retrospectively reviewed the data of 1582 men undergoing radical prostatectomy for clinically localized prostate cancer between 1995 and 2007 at 10 institutions in Korea for comparison with Western studies. The patients were divided into two groups in order to evaluate the recent clinicopathological changes in prostate cancer: Group 1 had surgery between 1995 and 2003 (n=280) and Group 2 had surgery between 2004 and 2007 (n=1302). The mean follow-up period was 24 months.
Results : Group 1 had a higher prostate-specific antigen level than Group 2 (10.0 ng/mL vs. 7.5 ng/mL, respectively; p<0.001) and a lower proportion of biopsy Gleason scores ≤6 (35.0% vs. 48.1%, respectively; p<0.001). The proportion of patients with clinical T1 stage was higher in Group 2 than in Group 1. Group 1 had a lower proportion of organ-confined disease (59.6% vs. 68.6%; p<0.001) and a lower proportion of Gleason scores ≤6 (21.3% vs. 33.0%; p<0.001), compared to Group 2. However, the relatively higher proportion of pathologic Gleason scores ≤6 in Group 2 was still lower than those of Western men, even though the proportion of organ-confined disease reached to that of Western series.
Conclusion : Korean men with prostate cancer currently present better clinicopathologic parameters. However, in comparison, Korean men still show relatively worse pathologic Gleason scores than Western men.ope
HOXB13 promotes androgen independent growth of LNCaP prostate cancer cells by the activation of E2F signaling
<p>Abstract</p> <p>Background</p> <p>Androgen signaling plays a critical role in the development of prostate cancer and its progression. However, androgen-independent prostate cancer cells emerge after hormone ablation therapy, resulting in significant clinical problems. We have previously demonstrated that the HOXB13 homeodomain protein functions as a prostate cancer cell growth suppressor by inhibiting androgen-mediated signals. However, the role of the HOXB13 in androgen-independent growth of prostate cancer cells remains unexplained.</p> <p>Results</p> <p>In this report, we first demonstrated that HOXB13 was highly overexpressed in hormone-refractory tumors compared to tumors without prostate-specific antigen after initial treatment. Functionally, in an androgen-free environment minimal induction of HOXB13 in LNCaP prostate cancer cells, to the level of the normal prostate, markedly promoted cell proliferation while suppression inhibited cell proliferation. The HOXB13-mediated cell growth promotion in the absence of androgen, appears to be mainly accomplished through the activation of RB-E2F signaling by inhibiting the expression of the p21<sup>waf </sup>tumor suppressor. Indeed, forced expression of HOXB13 dramatically decreased expression of p21<sup>waf</sup>; this inhibition largely affected HOXB13-mediated promotion of E2F signaling.</p> <p>Conclusions</p> <p>Taken together, the results of this study demonstrated the presence of a novel pathway that helps understand androgen-independent survival of prostate cancer cells. These findings suggest that upregulation of HOXB13 is associated with an additive growth advantage of prostate cancer cells in the absence of or low androgen concentrations, by the regulation of p21-mediated E2F signaling.</p
Yonsei Experience in Robotic Urologic Surgery - Application in Various Urological Procedures
PURPOSE: The da Vinci robot system has been used to perform complex reconstructive procedures in a minimally invasive fashion. Robot-assisted laparoscopic radical prostatectomy has recently established as one of the standard cares. Based on experience with the robotic prostatectomy, its use is naturally expanding into other urologic surgeries. We examine our practical pattern and application of da Vinci robot system in urologic field.
PATIENTS AND METHODS: Robotic urologic surgery has been performed during a period from July 2005 to August 2008 in a total of 708 cases. Surgery was performed by 7 operators. In our series, radical prostatectomy was performed in 623 cases, partial nephrectomy in 43 cases, radical cystectomy in 11 cases, nephroureterectomy in 18 cases and other surgeries in 15 cases.
RESULTS: In the first year, robotic urologic surgery was performed in 43 cases. However, in the second year, it was performed in 164 cases, and it was performed in 407 cases in the third year. In the first year, only prostatectomy was performed. In the second year, partial nephrectomy (2 cases), nephroureterectomy (3 cases) and cystectomy (1 case) were performed. In the third year, other urologic surgeries than prostatectomy were performed in 64 cases. The first robotic surgery was performed with long operative time. For instance, the operative time of prostatectomy, partial nephrectomy, cystectomy and nephroureterectomy was 418, 222, 340 and 320 minutes, respectively. Overall, the mean operative time of prostatectomy, partial nephrectomy, cystectomy and nephrourectectomy was 179, 173, 309, and 206 minutes, respectively.
CONCLUSION: Based on our experience at a single-institution, robot system can be used both safely and efficiently in many areas of urologic surgeries including prostatectomy. Once this system is familiar to surgeons, it will be used in a wide range of urologic surgeryope
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