35 research outputs found

    Thermal Properties and Magnetic Susceptibility of Hellmann Potential in Aharonov–Bohm (AB) Flux and Magnetic Fields at Zero and Finite Temperatures

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    This research deals with the behavior of recycled aggregate concrete (RAC). In this study an experimental work was undertaken. The study examines the effect of using recycled coarse aggregate (RCA) on the workability and the mechanical performance of RAC. The influences of using silica fume (SF) as cement replacement material on the performance of RAC were also examined. Silica fume was used at four contents (5%, 10%, 15% and 20%). The total number of mixes was six. Four mixes of RAC made with these four contents of SF, one RAC mix was made without SF and one mix was made with natural coarse aggregate (NCA) as a reference mix. The outcomes of this study reveal that workability and mechanical performance of RAC are lower than that made with NCA. Also, Silica fume has an adverse influence on workability of the RAC. However, the silica fume possesses a positive influence on mechanical properties of RAC. Silica fume can be used at contents of (10-20)% of cement mass to obtain mechanical performance for the RAC comparable to the concrete includes NCA

    Using Altman and Sherrod Z- Score Models to Detect Financial Failure for the Banks Listed on the Iraqi Stock Exchange (ISE) Between 2009 – 2013

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    Purpose: The Purpose of the study was to examine the validity of the Altman Z- Score and Sherrod Z- Score models in financial failure prediction. To achieve the study's goal, references from various authors who have reviewed this topic were used.   Theoretical framework: The study highlights the importance of analyzing and delving into the various notions of financial failure and distress. When it comes to potential effects on the wealth of creditors, stockholders, and society as a whole, academics and researchers consider a company's distress and bankruptcy to be the most important issue to be studied. In order to maintain the goal of company survival and continuity before the disaster happens, many academics started looking for a method to identify and forecast distress and failure.   Design/methodology/approach: Altman Z-score and Sherrod Z- score employed a multi-discriminant model to predict the financial position of ten ISE banks between 2009 - 2013. Z- Score models from Altman and Sherrod were used to determine whether the banks listed on the ISE are exposed to failing financially. Ten banks out of the forty - six banks listed on the ISE were selected. The study only used secondary data obtained from the chosen banks' financial statements in ISE.   Findings: Based on Altman's Z- score model, the study examines that certain banks are particularly exposed to failure. In contrast, the Sherrod Z- Score model indicates that the chosen banks have some issues, but they are minor, and the risk of bankruptcy is low.   Research, scientific and social implications: By using a failure prediction model, it is possible to determine the likelihood that banks will experience financial failure in the future. Investors could use this information to guide their decision-making going forward.   Originality/value: The value and importance of research related to the study of financial failure prediction models in Iraqi commercial banks. The research also seeks to explain financial failure models and the extent to which investors benefit from these models

    Superior loco-regional control after primary surgery compared to chemo-radiotherapy for advanced stage laryngeal cancer.

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    OBJECTIVE The optimal strategy to treat loco-regionally advanced squamous cell carcinoma of the larynx (LSCC) remains to be defined. The goal of this single institution retrospective study was to report on oncologic outcome of advanced LSCC treated with curative intent. METHODS Patients diagnosed and treated for stage T3-T4a LSCC between 2001 and 2014 were retrospectively analyzed. Time-to-event endpoints were calculated beginning from the date of histologic diagnosis, which were analyzed with log-rank test and Cox proportional hazard models. RESULTS The cohort was divided into two subgroups: primary radiotherapy with concomitant cisplatin (CRT) (n=30, 38%) and primary surgery (n=48, 62%). Median follow-up was 56 months. Locoregional control (LRC) for the primary surgery and CRT were 95% and 50% in 5 years, respectively (p<0.01). Progression free survival (PFS) for the primary surgery and CRT were 61% and 38% in 5 years, respectively (p=0.23). The overall survival (OS) after primary surgery and CRT in 5 years were 63% vs. 65%, respectively (p=0.93). The 5-years LRC was significantly superior after surgery compared to RT for cT3 primaries (100% vs 50%, p= 0.0022). No significant differences were observed in the remaining subgroups regarding cT stage and PFS or OS. CONCLUSION Our series demonstrated superior LRC after primary surgery followed by risk-adapted adjuvant (C)RT compared to primary CRT in cT3 LSCC, but no significant difference in PFS or OS in locally-advanced LSCC. The optimal patient selection criteria for the ideal treatment for loco-regionally advanced LSCC still needs to be defined

    Dose-escalated salvage radiotherapy after radical prostatectomy in high risk prostate cancer patients without hormone therapy: outcome, prognostic factors and late toxicity

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    Purpose: Evaluation of dose escalated salvage radiotherapy (SRT) in patients after radical prostatectomy (RP) who had never received antihormonal therapy. To investigate prognostic factors of the outcome of SRT and to analyze which patient subsets benefit most from dose escalation. Materials and methods: Between 2002 and 2008, 76 patients were treated in three different dose-groups: an earlier cohort treated with 66 Gy irrespective of pre-RT-characteristics and two later cohorts treated with 70 Gy or 75 Gy depending on pre-RT-characteristics. Biochemical-relapse-free-survival (bRFS), clinical-relapse-free-survival (cRFS) and late toxicity were evaluated. Results: Four-year bRFS and cRFS were 62.5% and 85%. Gleason score &lt;8, positive surgical resection margin (PSRM) and low PSA (&lt;= 0.5 ng/ml) before SRT resulted in higher bRFS. Analysis of the whole group showed no clear dose-outcome relationship. Patients with PSRM, however, had improved bRFS when escalating &gt;66 Gy. While &gt;70 Gy did not improve the overall results, 4-year bRFS for patients with manifest local recurrence in the high-dose group was still comparable to those without manifest local recurrences. No grade 4 and minimal grade 3 gastrointestinal and urinary toxicity were observed. Conclusions: Dose-escalated SRT achieves high biochemical control. The data strongly support the application of at least 70 Gy rather than 66 Gy. They do not prove positive effects of doses &gt;70 Gy but do not disprove them as these doses were only applied to an unfavorable patients selection

    Influencing Factors on Radiotherapy Outcome in Stage I-II Glottic Larynx Cancer—A Multicenter Study

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    Background and Purpose: Larynx cancer represents one of the most frequently diagnosed head and neck malignancies, which is most often confined to the glottic area. The aim of this study was to report the oncological outcome and identify prognostic factors in early-stage glottic squamous cell carcinoma treated with radiotherapy. Material and Methods: Patients (n = 761) diagnosed and treated in 10 centers between 1990 and 2015 were retrospectively analyzed. Probabilities of loco-regional control (LRC) and overall survival (OS) were calculated and possible prognostic factors were analyzed using Cox proportional hazards models. Results: The median follow-up was 63 months (range: 2-243). Three hundred and sixty-four, 148 and 249 patients had cT1a, cT1b, and cT2 stage I-II disease, respectively. Five and 10-years LRC/OS rates in the whole cohort were 83/82% and 80/68%, respectively. Three patients developed distant recurrences. In univariate analysis, male sex (HR: 3.49; 95% CI: 1.47-11.37; p < 0.01), T2 vs. T1a (HR: 1.62; 95% CI: 1.08-2.43; p = 0.02) and anterior commissure involvement (ACI) (HR: 1.66; 95% CI: 1.38-2.45; p < 0.01) were associated with impaired LRC. In multivariate analysis, male sex (HR: 3.42; 95% CI: 1.44-11.17; p < 0.01) and ACI (HR: 1.51; 95% CI: 1.01-2.28; p = 0.047) remained poor prognostic factors. No relation of treatment technique and biologically equivalent dose (BED) to oncological outcome was identified except for higher BED10(L = 25; T = 1) yielding better LRC in T1a tumors (p = 0.04) in univariate analyses. Conclusion: Our results highlight the negative impact of ACI on tumor control. A less-expected finding was the impact of sex on tumor control. Further research is needed to validate its prognostic value and investigate any related biologic or behavioral factors, which may be modified to improve oncologic outcome

    Disease Control With Delayed Salvage Radiotherapy for Macroscopic Local Recurrence Following Radical Prostatectomy

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    Purpose: To retrospectively assess clinical outcomes and toxicity profile of prostate cancer patients treated with delayed dose-escalated image-guided salvage radiotherapy (SRT) for macroscopic local recurrence after radical prostatectomy (RP).Material and Methods: We report on a cohort of 69 consecutive patients with local recurrence after RP and no evidence of regional or distant metastasis who were referred for salvage radiotherapy between 2007 and 2016. SRT consisted of 64–66 Gy (2 Gy/fraction) to the prostatic bed followed by dose escalation to 72–74 Gy (2Gy/fraction) to the macroscopic disease. All patients received concurrent short-term androgen deprivation therapy (ADT). Biochemical recurrence-free survival (bRFS) and clinical progression-free-survival (cPFS) were depicted using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predictors of survival outcomes. Baseline, acute, and late urinary and gastrointestinal (GI) toxicity rates were reported using CTCAE v4.03.Results: Median time from RP to SRT was 66 months (IQR: 32–124). Median pre-SRT prostate-specific antigen (PSA) was 2.7 ng/ml (IQR: 0.9–6.5). Median follow-up after SRT was 38 months (IQR: 24–66). The 3- and 5-year bRFS were 58 and 44%, respectively. The 3- and 5-year cPFS were 91 and 76%, respectively. Median time from SRT to clinical disease progression was 102 months (IQR 77.5–165). At baseline, 3 patients (4%) had grade 3 urinary symptoms. Six patients (9%) developed acute and six patients (9%) developed late grade 3 urinary toxicity. Five patients (7%) had acute grade 2 GI toxicity. No acute grade 3 GI toxicity was reported. Late grade 3 GI toxicity was reported in one patient (1.5%).Conclusions: Delayed dose-escalated SRT combined with short-course ADT for macroscopic LR after RP was associated with 44% bRFS and 76% cPFS at 5 years. Albeit improved patient stratification is warranted, these data suggest that delayed SRT provides inferior tumor control compared to early intervention

    The prognostic significance of a negative PSMA-PET scan prior to salvage radiotherapy following radical prostatectomy.

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    AIM The optimal management for early recurrent prostate cancer following radical prostatectomy (RP) in patients with negative prostate-specific membrane antigen positron-emission tomography (PSMA-PET) scan is an ongoing subject of debate. The aim of this study was to evaluate the outcome of salvage radiotherapy (SRT) in patients with biochemical recurrence with negative PSMA PET finding. METHODS This retrospective, multicenter (11 centers, 5 countries) analysis included patients who underwent SRT following biochemical recurrence (BR) of PC after RP without evidence of disease on PSMA-PET staging. Biochemical recurrence-free survival (bRFS), metastatic-free survival (MFS) and overall survival (OS) were assessed using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predefined predictors of survival outcomes. RESULTS Three hundred patients were included, 253 (84.3%) received SRT to the prostate bed only, 46 (15.3%) additional elective pelvic nodal irradiation, respectively. Only 41 patients (13.7%) received concomitant androgen deprivation therapy (ADT). Median follow-up after SRT was 33 months (IQR: 20-46 months). Three-year bRFS, MFS, and OS following SRT were 73.9%, 87.8%, and 99.1%, respectively. Three-year bRFS was 77.5% and 48.3% for patients with PSA levels before PSMA-PET ≀ 0.5 ng/ml and > 0.5 ng/ml, respectively. Using univariate analysis, the International Society of Urological Pathology (ISUP) grade > 2 (p = 0.006), metastatic pelvic lymph nodes at surgery (p = 0.032), seminal vesicle involvement (p 0.5 ng/ml (p = 0.004), and lack of concomitant ADT (p = 0.023) were significantly associated with worse bRFS. On multivariate Cox proportional hazards, seminal vesicle infiltration (p = 0.007), ISUP score >2 (p = 0.048), and pre SRT PSA level > 0.5 ng/ml (p = 0.013) remained significantly associated with worse bRFS. CONCLUSION Favorable bRFS after SRT in patients with BR and negative PSMA-PET following RP was achieved. These data support the usage of early SRT for patients with negative PSMA-PET findings

    Development and Validation of a Multi-institutional Nomogram of Outcomes for PSMA-PET-Based Salvage Radiotherapy for Recurrent Prostate Cancer.

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    IMPORTANCE Prostate-specific antigen membrane positron-emission tomography (PSMA-PET) is increasingly used to guide salvage radiotherapy (sRT) after radical prostatectomy for patients with recurrent or persistent prostate cancer. OBJECTIVE To develop and validate a nomogram for prediction of freedom from biochemical failure (FFBF) after PSMA-PET-based sRT. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study included 1029 patients with prostate cancer treated between July 1, 2013, and June 30, 2020, at 11 centers from 5 countries. The initial database consisted of 1221 patients. All patients had a PSMA-PET scan prior to sRT. Data were analyzed in November 2022. EXPOSURES Patients with a detectable post-radical prostatectomy prostate-specific antigen (PSA) level treated with sRT to the prostatic fossa with or without additional sRT to pelvic lymphatics or concurrent androgen deprivation therapy (ADT) were eligible. MAIN OUTCOMES AND MEASURES The FFBF rate was estimated, and a predictive nomogram was generated and validated. Biochemical relapse was defined as a PSA nadir of 0.2 ng/mL after sRT. RESULTS In the nomogram creation and validation process, 1029 patients (median age at sRT, 70 years [IQR, 64-74 years]) were included and further divided into a training set (n = 708), internal validation set (n = 271), and external outlier validation set (n = 50). The median follow-up was 32 months (IQR, 21-45 months). Based on the PSMA-PET scan prior to sRT, 437 patients (42.5%) had local recurrences and 313 patients (30.4%) had nodal recurrences. Pelvic lymphatics were electively irradiated for 395 patients (38.4%). All patients received sRT to the prostatic fossa: 103 (10.0%) received a dose of less than 66 Gy, 551 (53.5%) received a dose of 66 to 70 Gy, and 375 (36.5%) received a dose of more than 70 Gy. Androgen deprivation therapy was given to 325 (31.6%) patients. On multivariable Cox proportional hazards regression analysis, pre-sRT PSA level (hazard ratio [HR], 1.80 [95% CI, 1.41-2.31]), International Society of Urological Pathology grade in surgery specimen (grade 5 vs 1+2: HR, 2.39 [95% CI, 1.63-3.50], pT stage (pT3b+pT4 vs pT2: HR, 1.91 [95% CI, 1.39-2.67]), surgical margins (R0 vs R1+R2+Rx: HR, 0.60 [95% CI, 0.48-0.78]), ADT use (HR, 0.49 [95% CI, 0.37-0.65]), sRT dose (>70 vs ≀66 Gy: HR, 0.44 [95% CI, 0.29-0.67]), and nodal recurrence detected on PSMA-PET scans (HR, 1.42 [95% CI, 1.09-1.85]) were associated with FFBF. The mean (SD) nomogram concordance index for FFBF was 0.72 (0.06) for the internal validation cohort and 0.67 (0.11) in the external outlier validation cohort. CONCLUSIONS AND RELEVANCE This cohort study of patients with prostate cancer presents an internally and externally validated nomogram that estimated individual patient outcomes after PSMA-PET-guided sRT

    [Early salvage radiation therapy of the prostate bed appears to be equally effective compared to adjuvant radiation therapy after radical prostatectomy].

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    This review details and discusses the technological quality requirements to ensure the desired quality for stereotactic radiotherapy using photon external beam radiotherapy as defined by the DEGRO Working Group Radiosurgery and Stereotactic Radiotherapy and the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The covered aspects of this review are 1) imaging for target volume definition, 2) patient positioning and target volume localization, 3) motion management, 4) collimation of the irradiation and beam directions, 5) dose calculation, 6) treatment unit accuracy, and 7) dedicated quality assurance measures. For each part, an expert review for current state-of-the-art techniques and their particular technological quality requirement to reach the necessary accuracy for stereotactic radiotherapy divided into intracranial stereotactic radiosurgery in one single fraction (SRS), intracranial fractionated stereotactic radiotherapy (FSRT), and extracranial stereotactic body radiotherapy (SBRT) is presented. All recommendations and suggestions for all mentioned aspects of stereotactic radiotherapy are formulated and related uncertainties and potential sources of error discussed. Additionally, further research and development needs in terms of insufficient data and unsolved problems for stereotactic radiotherapy are identified, which will serve as a basis for the future assignments of the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The review was group peer-reviewed, and consensus was obtained through multiple working group meetings

    Feasibility of Using Nanoparticles of SiO 2

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