ABSTRACT
Objective To develop a new botox-like polypeptide with anti-wrinkle and anti-aging functions, which will be used in the field of cosmetics and dermatology. Methods A series of new peptide compounds were synthesized via modifying the structure of SYN-AKE by peptide synthesis technology. Simulating muscle contraction by using co-culture model of human muscle cells and mouse embryonic spinal cord neurons to test the effects. Results Six new synthetic peptides were selected. The results showed that the muscle contraction frequency was lowered by adding C19 H30 N5 O4 compound than adding SYN-AKE in 1 min(P<0.05). Conclusion C19H30N5O4 is expected to become a new cosmetic peptide raw material and dermatology drug in the field of anti-wrinkle and anti-aging.
ABSTRACT
Objective To develop a new botox-like polypeptide with anti-wrinkle and anti-aging functions, which will be used in the field of cosmetics and dermatology. Methods A series of new peptide compounds were synthesized via modifying the structure of SYN-AKE by peptide synthesis technology. Simulating muscle contraction by using co-culture model of human muscle cells and mouse embryonic spinal cord neurons to test the effects. Results Six new synthetic peptides were selected. The results showed that the muscle contraction frequency was lowered by adding C19 H30 N5 O4 compound than adding SYN-AKE in 1 min(P<0.05). Conclusion C19H30N5O4 is expected to become a new cosmetic peptide raw material and dermatology drug in the field of anti-wrinkle and anti-aging.
ABSTRACT
PurposeTo perform a quality assurance program for Truebeam imaging system using MIMI phantom, and to evaluate the accuracy of the imaging system center with the radiation isocenter and the accuracy of couch shift.Materials and Methods The reference images of MIMI phantom were acquired using CT scanner. The reference images were imported into the treatment planning system and a simple plan was created. The MIMI phantom was placed on the treatment couch. The images were acquired using the MV/KV imaging system, and a match registration was performed with the reference images from the TPS.Results Measured over six months, the precision of the imager and linac's isocenter was <1 mm, and the couch shift accuracy was <1 mm. The measurements over six months demonstrate that isocenters of the MV/KV imaging systems on Truebeam system are stable.Conclusion The accuracy of the Truebeam imaging system center and couch shift is safe and reliable. The error of Truebeam imaging system center and couch shift can be tested on a monthly base.
ABSTRACT
Objective To perform a routine quality assurance procedure for Truebeam multi-leaf collimator (MLC) using MLC quality assurance (QA) phantom,verifying the reliability of MLC during the treatment.Methods MLC QA phantom was a specialized phantom for multi-leaf collimator QA,and contained five radio-opaque spheres that were embedded in an L-shape.The phantom was placed isocentrically on the Truebeam treatment couch for the tests.A quality assurance plan was settled up in the Eclipse v10.0 so that the fields for acquiring the necessary images could be created.The images were acquired by the electronic portal imaging device (EPID),and imported into the PIPSpro software for the analysis.The tests were delivered once a week for six weeks to verify consistency of the delivery,and the images were acquired in the same manner each time.Results For the leaf position test,the average position error was (0.21 ± 0.02) mm.The leaf width was measured at the isocenter,and the average error was (0.04±0.02) mm for the leaf width test.Multi-Port test showed the dynamic leaf shift error,the average error was (0.26 ± 0.04) mm.For the leaf transmission test,the average inter-leaf leakage value was 1.0％ ± 0.14％.Conclusions The MLC system of Truebeam could operate very well and the QA phantom is a useful test tool for the MLC QA.
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Objective To compare the dosimetric differences of volumetric modulated arc therapy (VMAT) for preoperative radiotherapy of rectal cancer using 6MV X-ray flattening filter-free (FFF) and flattening filter (FF) modes.Methods FF-VMAT and FFF-VMAT plans were designed for 15 rectal cancer patients with preoperative radiotherapy by planning treatment system (Eclipse 10.0),respectively.Prescription dose of PTV was 50 Gy in 25 fractions.When the plans were normalized to 50 Gy to 95 ％ of PTV,the dose volume histogram (DVH),target and risk organ doses,conformity indexes (CI),homogeneity indexes (HI),low dose volume of normal tissue (B-P),monitor units (MU) and treatment time (TT) were compared between the two kinds of plans.Results FF-VMAT provided the lower Dmean,V105,HI (P ＜ 0.05),and higher CI (P ＜ 0.05) compared with FFF-VMAT.Small intestine (D5),Bladder (D5,Dmean V40,V50),L-femoral head (V40),R-femoral head (Dmean) were lower in FF-VMAT than those in FFF-VMAT (P ＜ 0.05).FF-VMAT had higher B-P (V5) compared with FFF-VMAT (P ＜ 0.05).FF-VMAT reduced the monitor units (MU) by 21％ (382±53 vs 483±26,P ＜ 0.05),as well as the treatment time (TT) in FF-VMAT was no significant difference compared with that in FFF-VMAT [(148±4) s vs (146±3) s,P ＞ 0.05)].Conclusions The qualities of FF-VMAT and FFF-VMAT plans were comparable and both clinically acceptable.When comparing two plans,FF-VMAT showed better target coverage and some of OARs sparing.The MUs of FFF-VMAT were higher than those of FF-VMAT,yet were not delivered within the same time.
ABSTRACT
Objective To compare IMSure QA and MatriXX for intensity modulated radiotherapy plans,and to investigate the credibility of IMSure QA software.Methods Ten patients receiving intensity modulated radiotherapy were randomly chosen for the quality assurance plans with IMSure QA and MatriXX.Results The overall average of percentage pass points in 3％ and 3 mm were (98.1 ± 0.8) ％ with IMSure QA,and (97.9 ±0.6)％ with MatriXX(t =0.86,P ＞0.05).Conclusion IMSure QA can be a reliable verification tool for IMRT QA.