Browsing by Author "Colak, S"

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    Dissolution kinetics of phosphate rock with Cl-2 gas in water
    Abali, Y; Colak, S; Yartasi, A
    In this study the dissolution kinetics of phosphate rock with Cl-2 gas in aqueous media were investigated. The effect of particle size, solid-to-liquid ratio, gas flow rate, reaction temperature and stirring speed on the dissolution process were determined. It was observed that the dissolution of the phosphate rock increased with increasing gas flow rate and stirring speed and with decreasing particle size and solid-to-liquid ratio. Increasing reaction temperature increased the dissolution slightly between 12 degrees C and 30 degrees C and decreased it between 40 degrees C and 80 degrees C. By analysis of the experimental data using heterogeneous kinetic models it was determined that the dissolution process is controlled by diffusion through the fluid layer.
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    The optimisation of the dissolution of phosphate rock with Cl-2-SO2 gas mixtures in aqueous medium
    Abali, Y; Colak, S; Yapici, S
    In the present study, aimed at the production of phosphate compounds, the optimum process conditions were sought for the dissolution of phosphate rock from the Mardin-Mazidagi concentrate, The dissolution of this phosphate rock in aqueous solution saturated with a mixture of Cl-2-SO2 gases was optimized by passing Cl-2 gas through the final solution. Reaction temperature, solid-liquid ratio, Cl-2 gas flow rate, reaction period and stirring speed were employed as parameters. Using the Taguchi Fractional Design Method, it was found that the optimum process conditions, at which 93.35% P2O5 conversion was reached, were as follows: Reaction temperature: 20 degrees C Solid-liquid ratio: 1/7 (w/v) Cl-2 gas flow rate: 120 cm(3) min(-1) Reaction period: 20 Stirring speed: 600 min(-1).
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    Rapid drug desensitization with platin-based chemotherapy: Analysis of risk factors for breakthrough reactions
    Akin, BG; Erkoc, M; Korkmaz, ET; Ozturk, BO; Colak, S; Ates, FSO; Bavbek, S
    Background: All platin-based chemotherapeutics can cause hypersensitivity reactions (HSRs). With rapid drug desensitization (RDD), few patients experience breakthrough reactions (BTR) during desensitization. However, data about risk factors for BTRs during RDD in patients with HSRs to platins are limited. We first aimed to describe characteristics of our platin-reactive population and to validate the Brigham and Women's Hospital's (BWH's) RDD protocol in our population along with their outcomes with RDD. Our second aim was to identify the risk factors for BTRs. Method: This was a retrospective chart review (2013-2020) of patients with symptoms of immediate HSRs to platins. Initial HSRs were classified as grade 1, 2, or 3 based on their severity. Skin prick tests (SPT)/intradermal tests (IDT) were performed with implicated platins. A 12-step protocol was used during RDD. Results: The study comprised 65 women and seven men (mean age 57.78 +/- 8.73 years). Initial HSRs to carboplatin, cisplatin, and oxaliplatin occurred in 38, 13, and 21 patients, respectively. All patients reacted at the fifth (median) recurrent infusions (min:1, max:20). The median values for carboplatin, cisplatin, and oxaliplatin were 6 (1-20), 3 (1-15), and 3 (1-11), respectively. Most initial HSRs were grade 2 (n = 40, 55.6%) and 3 (n = 27, 37.5%); only 6.9% (n = 5) were grade 1. Patients with grade 1, 2, and 3 initial HSRs had positive platin skin test results at rates of 80%, 74%, and 88%, respectively. A total of 232 RDDs were performed in 72 patients and 98.7% of these desensitizations were completed. BTRs occurred in 56 (24.1%) (grade 1 n = 14, 25%; grade 2 n = 32, 57%; grade 3 n = 10, 18%) of these desensitizations. Breakthrough reactions were more severe in patients with positive SPTs or 1:100 or 1:10 dilutions of IDT (p = 0.014). BTR was not observed during RDD in any of the patients with positive 1:1 dilutions of IDT. Positivity on prick or 1:100 or 1:10 IDT increased the risk of BTR 5.058 times. There was no significant association between the risk of BTRs and age, drug cycle, sex, comorbidities, or atopy. Conclusion: In our experience, 98.7% of 232 RDDs to platins were completed successfully, showing that RDD was safe and effective. Drug skin test positivity is a potential marker for identifying high-risk patients who will have BTRs during RDDs to platins.