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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
اطلاعات دوره: 
  • سال: 

    2016
  • دوره: 

    -
  • شماره: 

    1 (74)
  • صفحات: 

    30-36
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    10758
  • دانلود: 

    9195
چکیده: 

Bone metastasis is a major clinical concern that can cause severe pain, bone fractures, spinalcord compression, hypercalcemia and other problems for patients. Variuos β emitter radionuclides havebeen used for bone pain palliation, but recently α emitter radionucliedes also have shown acceptable resultsof treatment of bone metastasis. radium-223 (t1/2=11.43 d) is one of the suitable α emitters that emits highenergy α particles (Ēav=5.64 MeV) with high linear energy transfer (LET) that delivers a killing dose to thetumor cells. In this research, the feasibility of production of radium-223 from radium-226 was studied inTehran Research Reactor (TRR) in thermal neutron flux of 4×1013 cm-2 s-1 using MATLAB software.Then, the data were compared with the experimental results. On average, over 80 percent agreement wasobserved between the calculated and experimental data, and under appropriate conditions the acceptableactivity of 227Ac as a precursor of 223Ra was obtained. The results showed that with one month neutronbombardment of 2.5 mg 226Ra in TRR and cooling for 4 months, it is theoretically possible to achieveabout 8.51 MBq (0.23 mCi) activity of 223Ra, that with respect to injection of about 3.7 MBq (0.1 mCi) perpatient (with normally 70 kg weight), it is possible to administer the produced 223Ra to more than 2 patientsin every equilibrium period.

آمار یکساله:  

بازدید 10758

دانلود 9195 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2022
  • دوره: 

    20
  • شماره: 

    1
  • صفحات: 

    75-81
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    36
  • دانلود: 

    31
چکیده: 

Background: We investigated therapeutic outcomes of radium-223 (Ra-223) treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases. Materials and Methods: Outcomes were retrospectively examined in 20 patients starting Ra-223 treatment at a single university hospital from January 2017 to January 2020. Results: Median patient age was 70 years. Median values included prostate specific antigen (PSA) 10. 73 ng/ml, PSA doubling time (PSADT) 3. 7 months, alkaline phosphatase (ALP) 315 IU/L, lactate dehydrogenase (LDH) 186 IU/L, neutrophil-to-lymphocyte ratio (NLR) 2. 22, and Gleason score 9. Extent of disease (EOD) was 3 or more in 55%, and Eastern Cooperative Oncology Group performance status was 0 in 80%. 16 patients (80%) completed Ra-223 treatment. Ra-223 was administered in 11 (55%) with ≤,3 lines of treatment and 9 (45%) with ≥,4. Concomitant drug was enzalutamide and abiraterone in 6 and 7 patients, respectively. Bone modifier agents (BMA) were used in 11 patients. Symptomatic skeletal events (SSE) occurred in 5 patients and were associated with abiraterone combination. BMA during Ra-223 treatment did not affect SSE. Median overall survival from initiation of Ra-223 treatment was 32. 7 months. Prognosis was significantly better with PSADT ≤,3 months, EOD ≤,2, no SSE, no opioid use, and completion of Ra-223 treatment. PSA, LDH, NLR, PSADT, and Ra-223 treatment line after mCRPC were associated with Ra-223 completion. Anemia of Grade 3 occurred in 1 patient. Conclusion: Ra-223 treatment is safe, with good prognosis if completed. Combination treatment with abiraterone during Ra-223 treatment may cause SSE.

آمار یکساله:  

بازدید 36

دانلود 31 استناد 0 مرجع 0
نویسندگان: 

اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    20
  • شماره: 

    3
  • صفحات: 

    289-293
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    3253
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 3253

دانلود 9195 استناد 315 مرجع 0
گارگاه ها آموزشی
اطلاعات دوره: 
  • سال: 

    2018
  • دوره: 

    6
  • شماره: 

    1
  • صفحات: 

    61-67
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    15961
  • دانلود: 

    16696
چکیده: 

A 76-year-old man with symptomatic bone metastases from castration-resistant prostate cancer underwent radium-223-dichloride (Ra-223) therapy. Before Ra-223 therapy, he had normal peripheral blood cell counts. Ra-223 therapy relieved his shoulder and low back pain. The elevation of the serum prostate-specific antigen (PSA), doubling every month during Ra-223 therapy, suggested a PSA flare or relapse. Some lesions showed decrease and some lesions showed increase on Tc-99m hydroxymethylene diphosphonate bone scintigraphy at two weeks after the third injection of Ra-223 therapy. Ra-223 therapy was discontinued due to thrombocytopenia that was getting worse rapidly. After treatment discontinuation, namely four weeks after the third injection of Ra-223, F-18 fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) /CT and a biopsy were performed to evaluate for metastases, and bone marrow metastases were found. Ra-223 was effective for osteoblastic lesions, but not for bone marrow metastases. FDG PET/CT, but not a Tc-99m based bone scan, detected diffuse bone marrow involvement by cancer. This case report is the first to clarify the utility of FDG PET for the detection of bone marrow metastases confirmed by pathological examination in Ra-223 therapy for progressive castration-resistant prostate cancer.

آمار یکساله:  

بازدید 15961

دانلود 16696 استناد 0 مرجع 444
اطلاعات دوره: 
  • سال: 

    2021
  • دوره: 

    9
  • شماره: 

    2
  • صفحات: 

    131-139
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    5692
  • دانلود: 

    9649
چکیده: 

Objective(s): Ra-223 is a promising radionuclide for the treatment of skeletal metastases in castration-resistant prostate cancer patients. This study aims to estimate the lower limits for feasible Ra-223 single-photon emission computerized tomography (SPECT) imaging using a Monte Carlo simulation study. Methods: The SPECT images were produced on a homemade code: the Monte Carlo simulation of electrons and photons for SPECT (MCEP-SPECT). The National Electrical Manufacturers Association (NEMA) phantom with six hot spheres of diameters of 37, 28, 22, 17, 13, and 10 mm installed inside, was used. The background activity concentration was 0. 6 kBq/mL, and the ratios of hot concentrations to the background (RHB) were 25, 20, 15, 10, and 5. When RHB was 15, the background concentrations of 1. 5, 0. 9, 0. 3, and 0. 15 kBq/mL were also tested. The energy window was 84 keV± 10%. The number of projections was 60/360° , and the acquisition time was 60 s per projection. Two kinds of collimators: middle-energy general-purpose (MEGP) and high-energy generalpurpose (HEGP), were examined. The SPECT images were evaluated based on two quantitative indexes: contrast-to-noise ratio (CNR) for detectability and contrast recovery coefficient (CRC) for quantitative accuracy. Results: The CRC for the HEGP collimator was 35– 40%, while the CRC for the MEGP collimator was 25– 30%. The CNRs for the MEGP collimator were larger than those for the HEGP collimator. The CNRs of the hot spheres with diameters less than 22 mm were lower than 5. 0 for both collimators, when RHB and the background concentration were 15 and 0. 6 kBq/mL, respectively. Based on the obtained results, it was estimated that the lower limit of RHB for the detection of the hot sphere with a diameter of 37 mm would be approximately 20 if the background concentration is 0. 05 kBq/mL. Conclusions: The MEGP collimator is superior in terms of detectability, while the HEGP collimator is superior in terms of quantitative accuracy. When the lesion size is small, the MEGP collimator may be favorable. Based on these results, the estimated lower limit of the activity concentration would be approximately 1 kBq/mL if the background concentration is 0. 05 kBq/mL for a large lesion.

آمار یکساله:  

بازدید 5692

دانلود 9649 استناد 0 مرجع 0
نویسندگان: 

SHAKIR KHAN M. | NAQVI A.H. | AZAM A. | SRIVASTAVA D.S.

اطلاعات دوره: 
  • سال: 

    2011
  • دوره: 

    8
  • شماره: 

    4
  • صفحات: 

    207-210
تعامل: 
  • استنادات: 

    455
  • بازدید: 

    56226
  • دانلود: 

    27872
چکیده: 

Background: Everyone is exposed to radon because it is present everywhere with varying concentrations. Radon and its progeny are well established as lung carcinogenic.Materials and Methods: Track etch technique using LR-115 plastic track detectors has been used to measure the effective radium content and radon exhalation rates in soil samples collected from urban area of Etah district of Uttar Pradesh province in Northern India.Results: The values of effective radium content are found to vary from 27.87 to 45.14 Bq.kg-1 with a mean value of 34.98 Bq.kg-1. The mass exhalation rates of radon vary from 2.38 × 10-6 to 3.86 × 10-6 Bq.kg-1.d-1 with a mean value of 2.99 × 10-6 Bq.kg-1.d-1. The surface exhalation rates of radon have been found to vary from 6.19 × 10-5 to 10.03 × 10-5 Bq.m-2.d-1 with a mean value of 7.77 × 10-5 Bq.m-2.d-1.Conclusion: Radon exhalation study is important for understanding the relative contribution of the material to the total radon concentration found inside the dwellings. The values of radium and radon exhalation rates are found to be below the safe limit recommended by OECD, 1979.

آمار یکساله:  

بازدید 56226

دانلود 27872 استناد 455 مرجع 0
strs
اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    25
  • شماره: 

    1
  • صفحات: 

    31-38
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    13705
  • دانلود: 

    9032
چکیده: 

(-)-Gephyrotoxin-223 was formally synthesized from chiral synthon 1 which has been chemoenzymatically synthesized in the presence of Candida Antartica lipase.  

آمار یکساله:  

بازدید 13705

دانلود 9032 استناد 0 مرجع 0
نویسندگان: 

Hameed A.S. | Hashim A.K. | Jasim Mohammed E.

اطلاعات دوره: 
  • سال: 

    2020
  • دوره: 

    18
  • شماره: 

    3
  • صفحات: 

    461-466
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    12161
  • دانلود: 

    16200
چکیده: 

Background: Many people in Iraq and indeed the world choose to drink coffee on a daily basis; accordingly, we planned to find the radium and uranium concentrations in addition to the Radon emission rate to determine if coffee shows the levels of radioactivity that may affect people’ s lives. Material and Methods: A nuclear track detector (CR-39) was used to study the natural radioactivity of ten samples of coffee collected from local Iraqi markets. Results: The effective radium content varied from 0. 13 to 0. 66 Bq/kg with a mean 0. 32 Bq/kg. The mass exhalation rates of radon vary from 0. 024 – 0. 121/kg. h, with a mean 0. 059 Bq/kg. h, while the surface exhalation rates of radon vary from 0. 47 – 2. 39/ 2. h, with a mean 1. 16 Bq/m2. h. Uranium content varied from 0. 10 to 0. 54 ppm with a mean value of 0. 26 ppm. Conclusion: Insofar as health effects are concerned, the results have shown that all the samples were entirely safe.

آمار یکساله:  

بازدید 12161

دانلود 16200 استناد 0 مرجع 0
نویسندگان: 

ABBASI A. | Mirekhtiary F.

اطلاعات دوره: 
  • سال: 

    2019
  • دوره: 

    17
  • شماره: 

    1
  • صفحات: 

    163-169
تعامل: 
  • استنادات: 

    455
  • بازدید: 

    29498
  • دانلود: 

    46793
چکیده: 

Background: One of the most significant radionuclides in natural drinking waters is 226Ra and its decay products. It is potential of health problems, including cancer risk. In this study, the effect of 226Ra concentration in 28 drinking water samples collected from the North Guilan province was investigated. Materials and Methods: The activity concentrations of 226Ra were measured by using of radon emanation method and Pylon AB-5 radon scintillation detector. The annual effective dose distribution by age groups, radiological risk and chemical toxicity risk were calculated in drinking water. Results: The activity concentration results range from a low limit of detection (LLD) 2. 0± 0. 1 mBq l-1 to 38. 2± 2. 4 mBq l-1. Also, the annual effective dose distribution by age groups estimated results were from 1. 8×10-6 Sv y-1 for adults to 1. 5×10-5 Sv y-1 for infants. The radiological risk assessment results were 1. 06×10-6 to 2. 03×10-5 for morbidity risk, 7. 32×10-7 to 1. 40×10-5 for mortality risk. The chemical toxicity risk results obtained from 1. 08×10-1 to 5. 63×10-3. Conclusion: The activity concentration level of 226Ra in all drinking water samples were less than the recommended level WHO for drinking water 1000 mBq l-1. Meanwhile, annual effective dose level, cancer morbidity, mortality risk and life annual daily dose due to consumption of selected drink water samples were less than the standard limit.

آمار یکساله:  

بازدید 29498

دانلود 46793 استناد 455 مرجع 3552
اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    19
  • شماره: 

    3
  • صفحات: 

    9-13
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    17954
  • دانلود: 

    9552
چکیده: 

Purpose: To investigate etiological factors of endophthalmitis in Farabi Eye Hospital. Methods: In a retrospective study, the clinical records of 223 patients admitted to the hospital with final diagnosis of endophthalmitis between March 2002 and March 2004 were reviewed. Analyzed factors included: age, sex, clinical presentation, clinical course, microbiological data, treatment modality, visual outcome, and surgical complications.Results: Two hundred twenty three patients with final diagnosis of endophthalmitis were evaluated. One hundred and fifty patients (67%) were male and 73 (33%) were female. 50.2% of the patients were older than 40 years, 14.3% fall in the range of 17-40 years and 30.5% in the range of 2-16 years, and 4.9% were younger than 2 years of age. 57% of endophthalmitis cases were postoperative, 40.5% were posttraumatic, and 2.5% were endogenous. Overall 15.9% of the cases had positive culture. Wound leakage was noted in 39% and vitreous loss in 22% of postoperative patients. During 3.5-6.5 months (mean 4.5 months) visual acuity was 20/400 or better in 69.5% of posttraumatic cases and in 44.5% of postoperative patients. Finally 92.8% of patients required at least one vitrectomy procedure as a part of their management. Evisceration or enucleation was performed in 8.1% as a primary operation or in the course of their treatment.Conclusion: The incidence of postoperative endophthalmitis in this study is similar to other studies.Posttraumatic endophthalmitis incidence is less than the mean incidence of other reports. The rate of positive culture was also less than other studies.

آمار یکساله:  

بازدید 17954

دانلود 9552 استناد 315 مرجع 0
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