1 V

I am in the Charge Station

Abstract

A new definition of electrolyte-solution acidity in the terms of "real" hydrogen-ion activity aH+r is proposed. The applicability of the Volta method for paH+ r determinations and for the establishment of a universal acidity scale in HClH 2O and HCOOHH 2O mixtures is shown.

Résumé

Une nouvelle méthode de détermination de la teneur en acide des solutionsélectrolytiques en fonction de la valeur "réelle" d'activitédes ions d'hydrogène aH+ r est proposée. En outre, l'on a montréla possibilitéde l'application de la méthode des différences Volta de potentiel pour la mesure de la grandeur paHr et pour l'établissement d'une echelle universelle de teneur en acide dans les mélanges HClH 2O et HCOOHH 2O.

Zusammenfassung

Eine neue Definition der Azidität von Elektrolytlösungen durch die Werte der "reellen" Wasserstoffionenaktivität aH+ r wird vorgeschlagen. Die Anwendbarkeit der Methode der Voltapotentialdifferenz-Messung zur Ermittlung der paH+ r-Werte und Bildung der universellen Aziditätskala in HClH 2O und HCOOHH 2O-Mischungen wird gezeigt.

Publisher Summary

Volta accepted the evidence of the attractive forces between the different particles of the electric fluid. His explanation of the electric phenomenon is based on the theory that an attractive force exists between a body and the electric fluid it contains, and that this force is dependent on the position of the particles that constitute the body. When these particles are excited by friction, they exchange places, and the balance of attractive forces is upset, causing the body to become electrized. To restore equilibrium, it is necessary that these forces should be balanced by either adding or subtracting such a quantity of electric fluid, that the natural balance of the system is reconstituted. With the condenser, Volta ascertained the existence of negative electricity in water vapor in the gas obtained by dissolving iron in a weak solution of sulfuric acid, and in the smoke of burning coal. He published his findings in a communication to the Royal Society of London.

Lightweight block ciphers based on symmetric cipher are tailored to addressing security issues for highly constrained Internet of things devices. In this article, we explore general software implementations of lightweight ciphers on GPU architectures, with a special focus on LED, Piccolo and PRESENT. First, we implement the lightweight block ciphers using lookup table based technique. Then we analyze the effect of different factors on the encryption performance, such as the size of lookup table, the parallelism level, the use of different type of memory and the idle state caused by data transmission. We evaluated the three lightweight block ciphers on Nvidia Tesla V100 and Nvidia GTX1060 GPUs. Finally, the experimental result shows a great improvement on all the investigated ciphers compared to the unoptimized implementations.

International Journal of Radiation Oncology*Biology*Physics

Volume 69, Issue 3, 1 November 2007, Pages 732-739

Clinical Investigation

The Different Volume Effects of Small-Bowel Toxicity During Pelvic Irradiation Between Gynecologic Patients With and Without Abdominal Surgery: A Prospective Study With Computed Tomography-Based Dosimetry

Author links open overlay panelEng-YenHuangM.D.∗†‡Kuender D.YangM.D., Ph.D.†

Outline

Cite

https://doi.org/10.1016/j.ijrobp.2007.03.060Get rights and content

Purpose

To evaluate the effect of abdominal surgery on the volume effects of small-bowel toxicity during whole-pelvic irradiation in patients with gynecologic malignancies.

Methods and Materials

From May 2003 through November 2006, 80 gynecologic patients without (Group I) or with (Group II) prior abdominal surgery were analyzed. We used a computed tomography (CT) planning system to measure the small-bowel volume and dosimetry. We acquired the range of small-bowel volume in 10% (V10) to 100% (V100) of dose, at 10% intervals. The onset and grade of diarrhea during whole-pelvic irradiation were recorded as small-bowel toxicity up to 39.6 Gy in 22 fractions.

Results

The volume effect of Grade 2–3 diarrhea existed from V10 to V100 in Group I patients and from V60 to V100 in Group II patients on univariate analyses. The V40 of Group I and the V100 of Group II achieved most statistical significance. The mean V40 was 281 ± 27 cm3 and 489 ± 34 cm3 (p < 0.001) in Group I patients with Grade 0–1 and Grade 2–3 diarrhea, respectively. The corresponding mean V100 of Group II patients was 56 ± 14 cm3 and 132 ± 19 cm3 (p = 0.003). Multivariate analyses revealed that V40 (p = 0.001) and V100 (p = 0.027) were independent factors for the development of Grade 2–3 diarrhea in Groups I and II, respectively.

Conclusions

Gynecologic patients without and with abdominal surgery have different volume effects on small-bowel toxicity during whole-pelvic irradiation. Low-dose volume can be used as a predictive index of Grade 2 or greater diarrhea in patients without abdominal surgery. Full-dose volume is more important than low-dose volume for Grade 2 or greater diarrhea in patients with abdominal surgery.

International Journal of Radiation Oncology*Biology*Physics

Volume 56, Issue 2, 1 June 2003, Pages 462-467

Clinical investigation: prostate

Is intraoperative nomogram-based overplanning of prostate implants necessary?

Author links open overlay panelWarren DD'SouzaPh.D.*AlanPollackM.D., Ph.D.*

Outline

Cite

https://doi.org/10.1016/S0360-3016(02)04620-5Get rights and content

Abstract

Purpose

Several investigators have described intraoperative planning of prostate implants based on a nomogram. The aim of this work was to investigate the adequacy of the nomogram in predicting the total activity necessary for optimal dosimetry.

Methods and materials

Eighty CT-based postimplant treatment plans were performed for patients who underwent ultrasound guided I-125 permanent implants alone between April 2000 and March 2001. The cohort of 40 patients had early stage (T1-T2) prostatic carcinoma and pre-treatment prostate volumes of 19–50 cc. I-125 seeds (0.391 mCi/seed) were implanted to achieve a distribution of 75% of the activity peripherally and 25% centrally. The CT studies were obtained on the day of (CT1) and at 1 month (CT2) after implant. All patients were catheterized at CT1, and 28 patients were catheterized at CT2 to visualize the urethra. For each patient, the percentage difference (dA) between the total implanted and nomogram predicted activity for a known prostate volume was calculated. The V200 (volume receiving 200% of the prescribed dose), V150, V100, V90, D100 (maximum dose received by 100% of the volume), D90, and D80 were measured for the prostate at CT1 and CT2. For the urethra, V275, V250, V200, and V150 were evaluated, and V100 and V70 were evaluated for the rectum. The Pearson test was used to correlate the dosimetric parameters with dA. Linear regression was used to fit the correlation of the volume and dose parameters with dA.

Results

The median V100 at CT1 and CT2 was 91.8% and 94.2%, respectively. The Pearson test was significant for the prostate V100 and dA measured at CT1 (p = 0.005) but not at CT2 (p = 0.106). A similar correlation was found for the prostate D90 at CT1 (p = 0.002), but not at CT2 (p = 0.076). D100 (maximum dose received by 100% of volume) for prostate did not correlate with dA at CT1 (p = 0.094) and CT2 (p = 0.148). The volume of the prostate receiving higher doses (greater than 150% and 200% of the prescribed dose) correlated with dA. There were no significant correlations between V275, V250, V200, and V150 at CT1 and CT2 as a function of dA for the urethra. V100 and V70 for the rectum correlated significantly with dA; for V100, p = 0.041 at CT1 and p = 0.014 at CT2 and for V70, p = 0.041 at CT1 and p = 0.026 at CT2. A linear regression model fitted to the prostate data obtained from CT1 with the goal of achieving a V100 of 90% and D90 of 145 Gy suggests that no increase in the number of seeds may be warranted using intraoperative planning. The implants examined showed no concomitant increase of urethral doses with increase in activity relative to the nomogram, but showed an increase in the rectal doses for the same increase in activity.

Conclusion

The doses evaluated at CT1 represent an underestimate, whereas those obtained at CT2 represent an overestimate of the actual delivered protracted permanent implant dose. Based on these results and consideration of the dynamic nature of the dose distribution, target coverage obtained with intraoperative planning using the nomogram predicted activity is consistent with published guidelines for a quality implant and critical structure doses are within tolerance.

Medical Dosimetry

Volume 41, Issue 4, Winter 2016, Pages 296-299

The comparison of 5-field conformal radiotherapy techniques for the treatment of prostate cancer: The best for femoral head sparing

Author links open overlay panelMahkamehZareM.D.*MahboobehAlamolhodaB.Sc.*

Outline

Cite

https://doi.org/10.1016/j.meddos.2016.06.008Get rights and content

Abstract

External radiotherapy is a standard treatment procedure for localized prostate cancer. Given the relatively high long term survival treatment complications have been brought in center of attention. In this planning study, between 2012 and 2014, CT simulation data of 90 consecutive high-risk prostate cancer patients were collected. In the first phase, all were planned for whole pelvis irradiation up to 46Gy in 23 daily fractions. In the second phase, only the prostate gland was the target of radiation. Next, the subjects were divided randomly into three groups and each received a unique 5field conformal radiation plan including Plan A (Gantry angle: 0, 60, 120, 240, and 300), Plan B (Gantry angles: 0, 90, 120, 240, and 270) and Plan C (Gantry angles: 0, 60, 90, 270, and 300). The total dose was 70Gy. For each patient, the rectum, bladder, and both femoral heads were contoured as the at risk organs (OAR). From dose volume histograms, the proportional dose of PTV V100, the bladder and rectum V80 and V90 and femoral head V50 and V100 were calculated in all subjects and compared across plans. A statistically significant difference in the femoral head V50 and V100 was found between our studied 5field plans so that in Plan A (beam angles: 0, 60, 120, 240 and 300) less dose was received by both heads of femur. This study suggests that 5 field treatment planning including an anterior, two anterior oblique and two posterior oblique portals to be more proper for 3D conformal radiotherapy in order to spare femoral head with acceptable PTV coverage, and bladder and rectal doses.

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