Niclosamide is the most commonly used molluscicide. Along with a lot of application of niclosamide more and more scientists studied its toxic effects to aquatic organisms as well as the related cell toxicity mechanism. This paper summariz?es the toxicity on cell organelle enzyme cell signaling pathway and genetic material caused by niclosamide and puts for?ward the future research direction.

Purpose: To analyze factors which influence the precision & accuracy of target positions in Alderson Head phantom and(or) patients.Materials and Methods: A target position simulator was used to determine the precision and accuracy of target localization while Alderson head phantom used to determine the overall precision and accuracy through the treatment procedure.Results: The overall precision and accuracy through the treatment procedure was found to be 1.72?0.60mm, and its contribution from CT localizing step, which was 1.4?0.3mm。Conclusion: Since there are more factors related to patients' treatment, the precision and accuracy of simulating in Alderson phantom is the best estimate for patient treatment.

Objective To introduce a finger leaf design that is applied to dual layer MLCs.Methods An optimization model was firstly constructed to describe the problem of determining leaf end shapes,and the corresponding problems were then solved by the simplex search method or the simulated annealing technique.Optimal parameters for arc shapes of leaf end projections were obtained,and a comparison was done between optimized MLCs and conventional MLCs in terms of field conformity.The optimization process was based on 634 target fields selected from the patient data base of a treatment planning system.Areas of these fields ranged from 20.0 to 602.7 cm with a mean and its standard deviation of (125.7 ±0.0) cm~2.Results The optimized leaf end shapes projected to the isocenter plane were semicircles.With the finger leaf design,the total area of discrepancy regions between MLC fields and target fields was reduced by 32.3% .Conclusions The finger leaf design improves the conformity of the MLC shaped fields to the desired target fields.

Objective To design leaf patterns for Multileaf Collimator(MLC)routine quality assurance(OA)with a 2D diode array.Methods According to the detector distribution characteristic of the 2D diode array and basillg on the"picket fence"pattern,design the"stepwise"pattern.For each diode involving MLC QA,a calibration curve of relative output versus leaf positioning error was measured through delivering a set of patterns with different intentionally introduced positioning errors.When this proposed technique was delivered,the referenced patterns were exposed,and the calibration curves were used as a mean to quantitative determination of the leaf possible positioning errors through the detector readings.Results Compared with the"picket fence"pattern,the"stepwise"pattern not only had a high detecting efficiency,but also increased the dosimetric sensidvity to leaf positioning error.A 1 mm Ieaf positioni.error corresponds to a dose variation of 25% for the"stepwise"pattern,while for the"picket fence"pattern the same positioning error just causes a 17% dose vailation.Conclusions The new"stepwise"pattern is more efficient to be carried out,and more sensitive to sub-millimeter changes of leaf positioning.

Objective To evaluate the improvement of cone beam CT (CBCT) image quality by using bewtie filter (F_1) and water calibration. Methods First the multi-level gain calibration of the detector panel with the method of Cal_2 calibration was performed, and the CT images of CATPHAN503 with F_0 and bowtic filter were collected, respectively. Then the detector panel using water calibration kit was calibrated, and images were acquired again. Finally, the change of image quality after using F_1 and (or) water calibration method was observed. The observed indexes included low contrast visibility, spatial uniformity, ring artifact, spatial resolution and geometric accuracy. Results Comparing with the traditional combination of F_0 filter and Cal_2 calibration, the combination of bowtie filter F_1 and water calibration improves low contrast visibility by 13.71%, and spatial uniformity by 54. 42%. Water calibration removes ring artifacts effectively. However, none of them improves spatial resolution and geometric accuracy. Conclusions The combination of F_1 and water calibration improves CBCT image quality effectively. This improvement is aid to the registration of CBCT images and localization images.

Biogenic molluscicides refer to the use of plants,animals and micro?organisms or their metabolites,and synthesis biomimetic molluscicides to kill Oncomelania hupensis snails. With the rapid development of science and technology,new bio?genic molluscicides are continuously emerging and the category also continues to expand. According to the molluscicidal active ingredient and sources,at present,the biogenic molluscicides with in?depth studies include plant?derived molluscicides,micro?organism molluscicides,microbial metabolite molluscicides and animal molluscicides. This paper reviews the advances in the re?searches of biogenic molluscicides in recent years.

Objective:Through the discussion on the purchasing mode of hospital equipment in China, fully understand the advantages and disadvantages of various procurement ways, choose reasonable acquisition method, optimize acquisition method, standardize the procurement management objective.Methods: By using the method of analogy, comparison of the four main acquisition methods. By the comparative analysis, the scope of each purchase way was confirmed. Results: Public bidding was better for more than 500000 yuan or the treasury payment items, competitive negotiation approach applies to 50000 yuan-500000 yuan purchase project. Consultation approach can be applied to 50000 yuan purchase project. Information project procurement preferred to methods of government procurement.Conclusion: Reasonable choices of purchasing and proper optimization has significant meaning for equipment purchasing and management in hospital.

Objective To investigate the molluscicidal effect of 5%niclosamide ethanolamine granules against Oncomela-nia hupensis in a marshland field. Methods The 5%niclosamide ethanolamine granules were sprayed at a dose of 40 g/m2 on 3 snail-breeding marshlands in Yangzhong City of Jiangsu Province to assess its field molluscicidal actions while 26%suspension concentrate of metaldehyde and niclosamide MNSC) at a dose of 4 g/m2 and fresh water served as controls. Results After seven days spraying, 5%niclosamide ethanolamine granules resulted in a of snail mortal85.42%ity while the mortality rates of snails were 82.35% and 2.86% in the MNSC and water control groups respectively. Conclusion 5% niclosamide ethanol-amine granules exhibit a high molluscicidal activity which is suitable to be used in the mashland.

Objective To develop a novel suspension concentrate of niclosamide (SCN) and evaluate its characteristics and molluscicidal effect against Oncomelania snails. Methods Niclosamide was milled by a sand granule mill and mixed with different amounts of wetting agent, dispersant agent, thickener, and water etc., to develop suspension concentrates, and its dispersion, suspensibility and stability were evaluated. According to the results of evaluation the best recipe and quality indexes for producing SCN were selected. The molluscicidal effects against Oncomelania snails were tested under lab condition and in field. Results The novel SCN contained 25% niclosamide (w/w), 1.5%-2.0% wetting agent (RS 3), 4% dispersant (FS 2), 0.10% thickener, a litte of other agent and water. The quality indexes which the SCN reached were as following: the content of niclosamide was more than 25%(w/w); the suspensibal rate was more than 90%; the pH was from 4 to 7; the size of more than 98% granules of niclosamide was smaller than 44?m; the thickener was smaller than 600 mpa.s. The SCN was very stable when it was stored in high or in low temperature. Under lab condition the LC 50 concentrations of SCN by the immersion method for 24, 48 and 72 hours were 0.0474 mg/L, 0.0412 mg/L and 0.0412 mg/L respectively while the LC 50 concentrations of 50% wettable powder of niclosamide (WPN) were 0.0947 mg/L, 0.0583 mg/L and 0.0442 mg/L. In the field death rates of the snails sprayed with 2.0 g/(L?m 2 ) of 25% SCN after 3, 7 and 15 days were 95.77%, 99.07%, 97.09% while the death rates of the snails sprayed with 2.0 g/(L?m 2 )of 50% WPN were 97.37%, 95.17% and 97.41%. Conclusion SCN had stable quality and high molluscicidal effect against Oncomelania snails, and it was suitable to be used in the field. The molluscicidal effect using 2.0 g/(L? m 2 ) of 25% SCN was similar with that using 2.0 g/(L?m 2) of 50% WPN.

ce, sIMRT and IMRT radiotherapy techniques can protect the lung and spinal cord well.