OBJECTIVE: To analyze and characterize the separation effectiveness of self-constructed asymmetrical flow field-flow fractionation system on proteins and lipoproteins, to achieve the optimization of the experimental conditions when separating lipoproteins by orthogonal design test and to investigate the carrier viscosity's influence on separation effectiveness. METHODS: The evaluation of asymmetrical flow field-flow fractionation separation capacity was conducted by using two standard proteins (carbonic anhydrase and thyroglobulin). Under the optimized separation conditions of carbonic anhydrase and thyroglobulin, the channel actual thickness (after assembling, the actual thickness of separation channel was less than initial thickness) was calculated by the analytes' elution time based on the hydrokinetic theory. With orthogonal design test the optimized experimental conditions were studied and statistical analysis was carried on to find out the factors with statistical significance which needed further exploration. RESULTS: According to the hydrodynamics principle and Stoke's function, the channel actual thickness was measured to be 164 μm by separating the two standard proteins, carbonic anhydrase and thyroglobulin, under proper experimental conditions. By the optimization based on orthogonal design test, base-line separation (the resolution had to be higher than 1.50) was achieved. The resolutions of the two experiments were 1.61 and 1.58. According to previous study/ pre-study and supporting theory, in the orthogonal design test, the total 5 factors were integrated for comprehensive investigation: the total flow rate (3.00, 3.50, 4.00, 4.50 mL/min), focus time (3.00, 3.50, 4.00, 4.50 min), transition time (0.5, 1.0, 1.5, 2.0 min), pH of the carrier fluid(6.8, 7.00, 7.20, 7.40) and viscosity of the carrier fluid hydroxypropylmethylcellulose concentration: 0.00%, 0.03%, 0.06%, 1.00%). Among the 5 factors, viscosity was found to have the statistical significance on separation effectiveness which was further investigated. The resolution of high density lipoprotein and low density lipoprotein was increased by the increasing viscosity which also caused more obvious negative spikes. CONCLUSION The separating capacities of self-constructed asymmetrical flow field-flow fractionation system on lipoproteins were verified to be effective and an optimized experimental condition was found to achieve the base-line separation of high density lipoprotein and low density lipoprotein. Viscosity of the carrier fluid was proved to have the statistical significance on lipoprotein separation.
Fractionation, Field Flow ; Lipoproteins ; Lipoproteins, LDL

The dummy template molecularly imprinted polymers not only has such characteristics of normal imprinted polymers as rapid identification, easy preparation, stable structure and multiple reuse, but also can imprint the compounds in natural products that are not suitable as direct template. Therefore, it has drawn more and more attention in the field of the study of natural products. This paper summarizes the methods for the selection of dummy template molecules by investigating the relevant literatures in the past ten years, analyzes the advantages and disadvantages of dummy template molecules in the practical application, and based on the types of natural products active ingredients, this paper is the first to review of the latest progress in extraction and separation of dummy template molecularly imprinted polymers. We believed that this paper could provide references for better applications of the dummy template molecularly imprinted polymers to extract and separate natural products.
Biological Products/chemistry* ; Chemical Fractionation ; Molecular Imprinting ; Polymers

To access the result of radiation therapy for 8 years experiences, 21 patients who were treated with superior vena cava syndrome had been analysed according to dose fractionation and toal dose. The results are as follows; 1. In high fractionate dose group, six of eleven patients (54.5%) exhibited relief of symptoms in 1-2 days, and additional three patients of nine (81.7%) within 3-4 days, while standard fractionated dose treatment is not effective to achieve initial relief of symptoms. 2. Graded response by total dose was correlated with total dose rather than dose fractionation. 3. Overall one year survival rate with superior vana cava syndrome was 9.1% and mean survival was 4.2 months.
Dose Fractionation ; Humans ; Radiotherapy ; Superior Vena Cava Syndrome* ; Survival Rate ; Vena Cava, Superior*

Total of 53 patients of unresectable and recurrent rectal cancer treated with neutron beam during the period from Oct. 1987 to Apr. 1992 were analyzed. Dose fractionation for the neutron only group was 1.5 Gy per fraction, 3 fraction per week, 21 Gy/41/2 wks for 42 patients out of 53(76%). Neutron only but modified fractionation schedule (10% more or less of total dose) was applied for 9 patients, and mixed team (neutron boost) was for 4 patients. Complete tumor response was obtained in 40 patients(76% response rate). Local control rate was 28 out of 53(53%). Statistically significant better prognostic factors for local control were age below 49 years old (15/22, 68%) than above 50 years old (13/31, 42%), male (20/32, 63%) than female(8/21, 38%), tumor size less than 5 cm and non-metastatic(16/24, 67%) than size more than 5 cm or metastatic(12/29, 4l%). Major complication had developed in 7 patients (13%). Two year overall survival rate by Kaplan-Meier method was 30%, but it was rised to, 47% when the tumor was less than 5cm non-metastatic.
Appointments and Schedules ; Dose Fractionation ; Humans ; Male ; Middle Aged ; Neutrons* ; Rectal Neoplasms* ; Survival Rate

For further improving the extraction efficiency of microwave extraction, a microwave-assisted contijuous extraction (MACE) device has been designed and utilized. By contrasting with the traditional methods, the characteristics and extraction efficiency of MACE has also been studied. The method was validated by the analysis of the triterpenoids in Ganoderma lucidum. The extraction conditions of MACE were: using 95% ethanol as solvent, microwave power 200 W and radiation time 14.5 min (5 cycles). The extraction results were subsequently compared with traditional heat reflux extraction ( HRE) , soxhlet extraction (SE), ultrasonic extraction ( UE) as well as the conventional microwave extraction (ME). For triterpenoids, the two methods based on the microwaves (ME and MACE) were in general capable of finishing the extraction in 10, 14.5 min, respectively, while other methods should consume 60 min and even more than 100 min. Additionally, ME can produce comparable extraction results as the classical HRE and higher extraction yield than both SE and UE, however, notably lower extraction yield than MASE. More importantly, the purity of the crud extract by MACE is far better than the other methods. MACE can effectively combine the advantages of microwave extraction and soxhlet extraction, thus enabling a more complete extraction of the analytes of TCMs in comparison with ME. And therefore makes the analytic result more accurate. It provides a novel, high efficient, rapid and reliable pretreatment technique for the analysis of TCMs, and it could potentially be extended to ingredient preparation or extracting techniques of TCMs.
Chemical Fractionation ; methods ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Microwaves ; Reishi ; chemistry ; Terpenes ; analysis ; isolation & purification

The schemes of dose fractionation play an important role in tumor radiotherapy. We used mathematical methods to describe the process of tumor cells evolution during radiotherapy, trying to find how the schemes of dose fractionation affect tumor cells. In clinical radiobiology, linear-quadratic (LQ) model is frequently used to describe radiation effects of tumor cells. We integrated LQ model with effect of oxygen, and with the phenomenon of repopulation and reoxygenation in the theory of radiation biology. While we considered the disappearing progress of doomed cells in tumor, we established the mathematical model of tumor evolution in radiotherapy. We simulated some common treatment schedules, and studied the change role of tumor cells during radiotherapy. These results can serve for the optimization of dose fractionation scheme based on tumor radiobiological characteristics.
Cell Growth Processes ; radiation effects ; Dose Fractionation ; Humans ; Models, Theoretical ; Neoplasms ; pathology ; physiopathology ; radiotherapy ; Radiobiology

It is well known that intracavitary radiotherapy (ICR), either alone or in combination with external-beam radiotherapy (EBRT) is an essential component of the radiation treatment of uterine cervical cancer. Although low-dose-rate (LDR) brachytherapy has been successfully applied to the management of such patients, several radiation oncologists have experience of using high-dose-rate (HDR) brachytherapy with promising clinical results over the past 4 decades. However, there has been a considerable reluctance by radiation oncologists and gynecologists in North America to employ the HDR remote afterloading technique instead of the more firmly established LDR treatment modality. In contrast, the HDR-ICR system is rapidly gaining acceptance in Korea since the introduction of the Ralstron, remotely controlled afterloading system using HDR Co-60 sources, at the Yonsei Cancer Center in 1979. According to brachytherapy statistics reported by the Korean Society of Therapeutic Radiology and Oncology, in 1997, brachytherapy was performed upon 1,758 Korean patients with uterine cervical cancer, of whom approximately 83% received HDR brachytherapy. In this review, we present our experiences of HDR-ICR for the treatment of uterine cervical cancer. In addition, we discuss the controversial points, which are raised by those considering the use of HDR-ICR for uterine cervical cancer; these issues include physical and radiobiological considerations, and the prospect of future technical improvements.
Brachytherapy/*methods ; Cervix Neoplasms/*radiotherapy ; Dose Fractionation ; Female ; Human ; Radiotherapy Planning, Computer-Assisted

PURPOSE: The purpose of this study was to describe treatment patterns of radiotherapy (RT) for prostate cancer in Korea. MATERIALS AND METHODS: A questionnaire about radiation treatment technique and principles in 2013 was sent to 83 radiation oncologists and data from 57 hospitals were collected analyzed to find patterns of RT for prostate cancer patients in Korea. RESULTS: The number of patients with prostate cancer treated with definitive RT ranged from 1 to 72 per hospital in 2013. RT doses and target volumes increased according to risk groups but the range of radiation doses was wide (60 to 81.4 Gy) and the fraction size was diverse (1.8 to 5 Gy). Intensity-modulated radiation therapy was used for definitive treatment in 93.8% of hospitals. Hormonal therapy was integrated with radiation for intermediate (63.2%) and high risk patients (77.2%). Adjuvant RT after radical prostatectomy was performed in 46 hospitals (80.7%). Indications of adjuvant RT included positive resection margin, seminal vesicle invasion, and capsular invasion. The total dose for adjuvant RT ranged from 50 to 72 Gy in 24–39 fractions. Salvage RT was delivered with findings of consecutive elevations in prostate-specific antigen (PSA), PSA level over 0.2 ng/mL, or clinical recurrence. The total radiation doses ranged from 50 to 80 Gy with a range of 1.8 to 2.5 Gy per fraction for salvage RT. CONCLUSION: This nationwide patterns of care study suggests that variable radiation techniques and a diverse range of dose fractionation schemes are applied for prostate cancer treatment in Korea. Standard guidelines for RT in prostate cancer need to be developed.
Dose Fractionation ; Humans ; Korea* ; Prostate* ; Prostate-Specific Antigen ; Prostatectomy ; Prostatic Neoplasms* ; Radiotherapy* ; Recurrence ; Seminal Vesicles

BACKGROUND/AIMS: This study reports treatment outcomes after helical intensity-modulated radiotherapy (IMRT) in unresectable hepatocellular carcinoma (HCC) patients for whom transarterial chemoembolization (TACE) was considered ineffective or unsuitable. METHODS: From January 2008 to December 2011, 22 unresectable HCC patients received helical IMRT. A daily dose of 1.8 to 4 Gy was delivered at five fractions per week to deliver a total dose of 30 to 60 Gy. The most-prescribed dose fractionation was a total dose of 50 to 57.5 Gy, with a daily dose of 2.3 to 2.5 Gy. RESULTS: In the entire group, the objective response rate of the primary tumor was 72.7%. In the eight patients with portal vein thrombosis (PVT), the objective response rate of PVT was 50.0%. Median disease progression-free survival was 11.8 months, and the 1-year disease progression-free survival rate was 40.2%. The median overall survival was 14.4 months, and the 1- and 2-year overall survival rates were 86.4% and 69.1%, respectively. PVT and Child-Pugh classifications were significant prognostic factors for overall survival in multivariate analyses. CONCLUSIONS: Helical IMRT in patients with unresectable HCC resulted in high treatment response and survival rates. This study suggests helical IMRT is a practical treatment option for HCC patients in whom TACE is unsuitable or ineffective.
Carcinoma, Hepatocellular ; Disease-Free Survival ; Dose Fractionation ; Humans ; Portal Vein ; Radiotherapy, Intensity-Modulated ; Survival Rate ; Thrombosis

In the previous review, the physical aspect of heavy particles, with a focus on the carbon beam was introduced. Particle beam therapy has many potential advantages for cancer treatment without increasing severe side effects in normal tissue, these kinds of radiation have different biologic characteristics and have advantages over using conventional photon beam radiation during treatment. The relative biological effectiveness (RBE) is used for many biological, clinical endpoints among different radiation types and is the only convenient way to transfer the clinical experience in radiotherapy with photons to another type of radiation therapy. However, the RBE varies dependent on the energy of the beam, the fractionation, cell types, oxygenation status, and the biological endpoint studied. Thus this review describes the concerns about RBE related to particle beam to increase interests of the Korean radiation oncologists' society.
Carbon ; Cell Fractionation ; Oxygen ; Photons ; Population Characteristics ; Protons ; Relative Biological Effectiveness