MicroRNA-494 (miR-494) is one of the microRNAs from 14q32.31 miR-gene cluster.Recently, miR-494 was found to closely relate with tumors and other diseases .This article reviews the expression changes , roles and possible regulatory mechanisms of miR-494 in multiple tumors and other hypoxia/ischemia diseases .Recent studies demon-strate that the expression of miR-494 is affected by many factors , and miR-494 could be a biomarker of diagnosis , staging and prognosis in tumors and other diseases , and a target of therapy in future .

Objective To study the dosimetric characteristics of flattened and flattening filter free (FFF) beams with 6 MV and 10 MV photon energy using a novel dual-energy medical linear accelerator (Elekta Versa HDTM),to identify the dosimetric characteristics and advantages of FFF beams,and to provide a basis for their clinical application.Methods The percentage depth dose (PDD),profiles/dose rate of off-axis ratio (OAR),field size,penumbral width,dose out of the fields,collimator scatter factor (Sc),and total scatter factor (Sc,p) were compared between flattened and FFF beams.Results (1) After beam energy matching,the FFF beams had the same beam energy with the flattened beams.The matching error of PDD at a depth of 10 cm was less than 1％ between fields.(2) The FFF beams had a smaller variation in dose rate of OAR with the depth than the flattened beams.(3) The FFF beams had smaller variations in field size and penumbral width than the flattened beams.Moreover,the penumbral width of the FFF beams increased with the increasing field size or depth.The FFF beams had a lower dose out of the fields than the flattened beams.(4) The FFF beams had smaller variations in Sc and Sc,p with the field size and depth than the flattened beams.Conclusions Removal of the flattening filter can substantially improve the dose rate,shorten radiotherapy time,and reduce leakage and scattering of the head.The dosimetric advantages make the FFF beams appropriate for clinical treatment.

Objective To evaluate the impacts of slice thickness and registration frame range on the accuracy of cone-beam computed tomography ( CBCT) image-guided head and neck ( HN) radiotherapy, and to provide a basis for positioning correction in image-guided radiotherapy.Methods A planned CT scan was performed for an anthropomorphic HN phantom with slice thickness of 1 mm and 3 mm and simulated positioning errors in x, y, and z directions on the accelerator.CBCT scan and reconstruction were performed with slice thickness of 1 mm and 3 mm.Two different registration frame ranges were used ( range 1:from C7 to superior orbit;range 2:from C7 to calvaria ) .Automatic bony registration was performed for CBCT and planned CT images with slice thickness of 1 mm and 3 mm.The registration accuracy was evaluated.Results For range 1, the registration errors in x, y, and z directions with a slice thickness of 1 mm were significantly lower than those with a slice thickness of 3 mm (0.5±0.2 mm vs.-0.7±0.2 mm, P=0.00;0.5±0.3 mm vs. 1.0±0.3 mm, P=0.00;-0.1±0.5 mm vs.1.5±0.5 mm, P=0.00).For range 2, the registration errors in x, y, and z directions with a slice thickness of 3 mm were-0.4±0.2 mm, 0.5±0.2 mm, and 0.7±0.4 mm, respectively.Conclusions Engagement of calvaria in registration range can substantially enhance the registration accuracy in CBCT or CT images for HN.The registration error with slice thickness of 1 mm can be controlled within 1 mm.

In this paper, the principle of computer vision was introduced and several typical radiotherapy devices based on computer vision were described, including their principle and applications.
Audiovisual Aids ; Imaging, Three-Dimensional ; Radiotherapy, Computer-Assisted ; methods ; Software

To synchronize the radiation of microSelectron-HDR (Nucletron afterloading machine) and measurement of MOSFET dose system, a trigger system based on interface circuit was designed and corresponding monitor and trigger program were developed on Qt platform. This interface and control system was tested and showed stable operate and reliable work. This adopted serial port detect technique may expand to trigger application of other medical devices.
Equipment Design ; Radiotherapy Dosage ; Radiotherapy, Computer-Assisted ; instrumentation ; methods

Objective To evaluate the accuracy of image registration based on bony structure (RBS) and grey-scale (RGS) in positioning correction of radiation treatment,and their reliability in clinical application.Methods Setup errors of anthropomorphic phantom (chest& abdomen,head& neck) were simulated with x-,y-,z-directions.CBCT images were acquired for each simulation and registered with planning CT.using bony structure and grey-scale registration separately.Geometry accuracy of all registration were then obtained and analyzed.Results The errors of RBS and RGS in x-,y-,z-directions were (-0.65 ±0.22) mm and (-0.70±0.17) mm (P=0.00),(1.02 ±0.27) mm and (0.90±0.20) mm (P =0.00),(1.46 ± 0.53) mm and (1.47 ± 0.47) mm (P =0.54) for head& neck positioning; with (0.82±0.33) mm and (0.79±0.18) mm (P=0.03),(2.45±1.17) mm and (1.61 ±0.84) mm (P =0.00),(1.44 ± 3.25) mm and (0.19 ± 1.11) mm (P =0.00) for chest& abdomen positioning.Conclusions RGS is more accurate and stable than RBS.The accuracy of image registration is a little better for head& neck than that for chest& abdomen.The algorithms of image registration used in clinical application needs to be tested independently and the systematic error needs to be corrected before applying in different treatment techniques according to their accuracy requirement.

This study preliminarily discussed the TCM syndrome types of myasthenia gravis (or flaccidity) and its treatments and prescriptions through consensus method,providing evidence and level revision of the recommended expert consensus of myasthenia gravis in TCM clinical practice guideline.Literatures over TCM syndrome types,symptoms,therapeutic regime,medication and acupuncture were involved in the syndrome analysis of myasthenia gravis through literature retrieval.The common clinical syndromes were outputted by mentioned rate.Ten first-rate hospitals were finally included,such as The Affiliated Hospital of Changchun University of Traditional Chinese Medicine,Dongfang Hospital of Beijing University of Chinese Medicine,Guangdong Province Traditional Chinese Medical Hospital and Affiliated Hospital of Anhui University of Traditional Chinese Medicine.Twelve experts in aggregate were confirmed to participate in the discussion for the identification of the TCM syndrome types,treatments and prescriptions of myasthenia gravis.As a result,five TCM syndrome types,such as syndrome of spleen and stomach qi deficiency,syndrome of spleen-kidney deficiency,deficiency syndrome of both qi and yin,syndrome of deficiency and sinking of qi,were confirmed;while five therapeutic regimes were approved,including reinforcement of qi,tonification of spleen and stomach,tonification of spleen and kidney qi,tonification of qi and yin,the supplement of qi and restoration of yang for ascending qi collapse.In addition,five prescriptions were supported by the experts,such as Bu Zhong Yi Qi (BZYQ) decoction,BZYQ decoction combined with You Gui pills,BZYQ decoction combined with Sheng Mai powders and Sheng Xian decoction.In conclusion,the expert consensus method for the screen of TCM syndrome types of myasthenia gravis embodied the conception of literature research based on the clinical practice combined with the scientific methods in conformity with the current research approaches to TCM syndrome types.

UNLABELLEDThe aim of this study is to investigate the characteristics of Elekta delivery system for volumetric modulated arc therapy (VMAT). Five VMAT plans were delivered in service mode and dose rates, and speed of gantry and MLC leaves were analyzed by log files. Results showed that dose rates varied between 6 dose rates. Gantry and MLC leaf speed dynamically varied during delivery.

CONCLUSIONThe technique of VMAT requires linac to dynamically control more parameters, and these key dynamic variables during VMAT delivery can be checked by log files. Quality assurance procedure should be carried out for VMAT related parameter.

Ischemic stroke is a common neurological disease. MicroRNAs not only play an important role in acute phase of ischemic stroke, but also regulate neurogenesis and angiogenesis after stroke. This article reviews the research progress and prospects of microRNAs as a therapeutic target for ischemic stroke.

Objective:To investigate the status and influential factors associated with 2-week prevalence of fever and diarrhea among infants and young children at the age of 6-23 months in poor rural areas.Methods:A total of 8 735 rural infants and young children aged 6-23 months in 30 poor counties of Wuling Mountains and Luoxiao Mountains in Hunan Province were selected in August 2015,and the questionnaires were used to collect information on the prevalence of fever and diarrhea,person and families,and feeding status.The data for prevalence of fever and diarrhea in infants and young children were calculated,and multi-non-conditional logistic regression model were used to analyze the influential factors.Results:The 2-week prevalence of fever and diarrhea in infants and young children was 20.8％ and 12.2％ respectively.The ages (OR=0.66,95％CI 0.58 to 0.75),Dong ethnicity(OR=1.42,95％CI 1.17 to 1.74) and low body weight (OR=1.31,95％CI 1.11 to 1.54) were influential factors for fever among infants and young children in poor rural areas;female (OR=0.86,95％CI 0.76 to 0.98),12-17 months (OR=0.80,95％CI 0.69 to 0.93),18-23 months (OR=0.51,95％CI 0.43 to 0.60),other ethnic minorities (OR=1.70,95％CI 1.13 to 2.56),non-complementary feeding (OR=1.65,95％CI 1.05 to 2.59) and low body weight (OR=1.39,95％CI 1.14 to 1.70) were the influential factors of diarrhea among infants and young children.Conclusion:The 2-week prevalence of fever and diarrhea among infants and young children aged 6-23 months in poor rural areas were quite serious.Low age,Dong ethnicity,and low birth weight are high risk factors for fever.Male,no addition of complementary feeding,and low birth weight are high risk factors for diarrhea.