This article expounds the method of quality control and quality assurance for the isocenter of the medical linear accelerator and explains the content and standards of its regular examinations, in order to ensure the safety and efficiency in use.
Particle Accelerators ; standards ; Quality Control ; Radiation Oncology ; instrumentation ; standards

Background The visual system of animal have to optimally adjust in various environmental conditions in order to obtain stable and effective visual funetion.However,the color vision system of animals which encounter uncertainty of spectral signals should be plastic.Whether the densities of various cones and expression of opsins change with long-time spectral deprivation is unclear.Objective This study was to investigate the changes of cone density as well as the expression of corresponding opsin and mRNA following the long-term illumination of monochromatic light.Methods Thirty 3-day-old guinea pigs were randomized into 3 groups and exposed tO the 530 nm green light,400 nm purple light and white light for consecutive 8 weeks respectively.The flat-mounted retinal sample was prepared and divided into dorsal zone,ventral zone and mixed zone anatomically according to the distribution of difierent light-sensitive cone.The changes in density of cone cells sensitivited to different colored light were detected by single-1abel or double-label immunocytochemistry.The levels of opsin and its mRNA were determined using Western-blot and real-time PCR respectively.Results The density of green-sensitivity cones was significantly different in the dorsal zone of retina among green light group,purple light group and white light group (F=234.28,P<0.01).Compared with white light group,the density of green-sensitive cones in dorsal retina of green light group was obviously higher but that of purple light group wag evidently lower(q=389.68,P<0.01；q=67.11,P<0.01).No significant difference was found in the density of purple-sensitive cones in the ventral zone of retina among green light group,purple light group and white light group(F=3.14,P>0.05).The density of coexpression of the mixed cone cells was increased in green light group(q=157.55,P<0.01)but decreased in purple light roup (q=254.85,P<0.01)in comparison with white light group.The expression levels of green-opsin and green-opsin mRNA in green light group was significantly elevated(q=184.45,P<0.01；q=4.71,P<0.05),but those of purple light group were evidently declined(q=5.87,P<0.05；q=346.66,P<0.01)in comparison with white light group.There was no statistically significant differences were found in the expression of purple-opsin and its mRNA among all the groups(F=1.24,P>0.05；F=3.27,P>0.05).Conclusion After the exposure of long-time monochromatic light illumination,monochromatic cones density and its opsin in guinea pig occur the corresponding alteration to gain good spatial vision as a compensatory reaction.These outcomes imply that there is some plasticity during the development of color vision.The increase of green-sensitive cones might be from the differentiation of coexpression cones in transition region.

This article expounds the quality assurance for the radiotherapy simulator. Emphasis is given to its necessities and the methods, and standards of regular examinations are illustrated for the aim of meeting the requirements of the quality assurance in radiotherapy by the WHO.
Quality Assurance, Health Care ; Quality Control ; Radiotherapy ; instrumentation

OBJECTIVE: To evaluate the sub-acute oral effect of titanium dioxide (TiO₂) nanoparticles on the oxidation/antioxidation biomarkers and inflammatory cytokines in blood, liver, intestine, and colon in rats. METHODS: Twenty four 4-week-old clean-grade Sprague Dawley (SD) rats were randomly devided into 4 groups by body weight (n=6, control, low, middle, and high), in which the rats were orally exposed to TiO₂ nanoparticles at doses of 0, 2, 10 and 50 mg/kg body weight/day for 28 consecutive days separately. Food intake, body weight and abnormal behaviors during the experiment were recorded. The rats were euthanized on the 29th day. The blood was collected via abdominal aortic method and centrifuged to collect the serum. Tissues from liver, intestine and colon were collected and homogenated. Then enzyme-linked immunosorbent assay (ELISA) and microwell plate methods were used to detect oxidation/antioxidation biomarkers including superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px), total mercapto (T-SH), glutathione disulfide (GSSG), malomdialdehvde (MDA) and inflammatory cytokines including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the serum, liver, intestine and colon in the rats. RESULTS: Compared with the control group, no significant differences in body weight, food intake and organ coefficients were observed in all the three groups after TiO₂ gavage. No significant changes in GSH, GSH-Px, T-SH, and IL-6 were observed. Compared with the control group, significant increase of SOD activity in serum in high dose group, signi-ficant increase of GSSG concentration in intestine in middle and high dose group and significant increase of MDA concentration in liver in low and high dose group were observed. Compared with the control group, a significant increase of TNF-α in liver in middle and high dose group was observed. CONCLUSION TiO₂ nanoparticle can increase antioxidant enzymes activities in blood, increase oxidative biomarkers in liver and intestine, increase inflammatory cytokines in liver in rats after a 28-day sub-acute orally administration. Among blood, liver, intestine, and colon, liver is most sensitive to the toxicity induced by TiO₂ nanoparticles, followed by intestine, blood, and colon in sequence.
Animals ; Antioxidants ; Biomarkers ; Cytokines ; Nanoparticles ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Titanium

Taking Children's Hospital in Hunan Province as an example,the paper introduces the design and application of the security mode for the mobile business platform of hospital from the aspects of the overall structure,implementation plans of security access equipment,security authentication modes and strategies,etc.,and provides ideas for safely implementing remote deployment and mobile application.

The paper points out that informatization development of hospital has three stages,namely,the stage of hospital management informatization,the stage of clinical management informatization and the stage of regional health informatization.It expatiates on the impact of each stage on medical staffs' behavior,points out that informatization is able to increase medical staffs' work efficiency,regulate their diagnosis and treatment behavior and enhance diagnosis and treatment quality.

In order to improve the access and control of core data in medical information security,the paper builds a virtual isolation private cloud storage architecture in hospital,including virtualized reconstruction,metadata model application based on hierarchical model,access to remote clients design and application based on virtual isolation and so on,providing a reliable method for the isolation and intercommunication between the intranet and extranet.

Adult ; Aged ; Bone Screws ; Female ; Femoral Neck Fractures ; surgery ; Fracture Fixation, Intramedullary ; Humans ; Internal Fixators ; Male ; Middle Aged

OBJECTIVETo study the related factors of right recurrent nerve nodal involvement in esophageal cancer.

METHODS280 patients with thoracic esophageal cancer received esophagectomy and right recurrent nerve node dissection. The clinicopathological data were analyzed retrospectively. Univariate data were analyzed by chi-square test, and multivariate data were analyzed by logistic regression.

RESULTSThe right recurrent nerve nodal metastasis was found in 76 cases (27.1%, 76/280). In the 979 excised right recurrent nerve nodes, metastases were found in 118 nodes (12.1%). The tumor staging, the total number of involved lymph nodes, vascular invasion, the number of lymph node metastases in the thorax, the number of lymph node metastasis in the abdomen, subcarinal node metastasis, and peri-esophageal lymph node metastasis were independent risk factors of right recurrent nerve node metastasis in esophageal carcinoma.

CONCLUSIONRight recurrent nerve lymph nodes should be dissected in those patients with high risk factors of lymph node metastasis in thoracic esophageal carcinoma.

Adult ; Aged ; Esophageal Neoplasms ; pathology ; surgery ; Esophagectomy ; Female ; Humans ; Logistic Models ; Lymph Node Excision ; Lymph Nodes ; pathology ; surgery ; Lymphatic Metastasis ; Male ; Middle Aged ; Recurrent Laryngeal Nerve ; pathology ; Retrospective Studies ; Risk Factors

OBJECTIVETo compare the clinical results of early and delayed intramedullary nailing and locked plating for the treatment of multi-segments tibial fractures of type AO/ASIF-42C2.

METHODSBetween January 2010 and January 2013,45 patients with multi-segments closed tibial fractures of AO/ASIF-42C2 were treated by early primary intramedullary nailing and locked plating in 20 cases as early group and delayed in 25 cases as delayed group. In early group,20 cases included 13 males and 7 females with an average age of (37.9±14.3) years old ranging from 20 to 56 years;according to soft tissue injury Tscherne classification, 8 fractures were frade I,12 were grade II. In delayed group, 25 cases included 17 males and 8 females with an average age of (38.7±17.2) years old ranging from 24 to 55 years,4 fractures were grade I ,19 were grade II ,2 were grade III. The operative time, blood loss, hospital stay,fracture healing time and complications were recorded. At final follow-up, the Johner-Wruhs score were used to evaluate functional efficacy, and the posterior-anterior and lateral X-ray to evaluate fracture reduction and alignment.

RESULTSAll the patients were followed up for (12.5±2.5) months in early group and (13.2±2.8) months in delayed group (P>0.05). No wounds infections were happened. At the last follow-up, the mean range of knee joint was 10°-0°-120°. According to Johner-Wruhs scoring,there were 15 cases in excellent,3 in good,fair in 2 in early group; 21 in excellent,2 in good,2 in fair. The average operative time,blood loss had no significant differences between two groups (P>0.05), but hospital stay in early group was significantly shorter than those in delayed group(P<0.05). Average fracture healing time of early group and delayed group were (5.3±2.6) months and (6.0±2.9) months, respectively (P>0.05).

CONCLUSIONFor multi-segments tibial fractures of type AO/ASIF-42C2 with preoperative minor soft tissue injuries lighter of Tscherne grade I or II, early primary intramedullary nailing and locked plating does not significantly increase the postoperative incidence of soft tissue complications for patients. The early and delayed primary intramedullary nailing and locked plating for treatment of AO/ASIF-42C2 proximal third tibial fractures can get similar curative effect.

Adult ; Bone Plates ; Female ; Fracture Fixation, Intramedullary ; methods ; Humans ; Male ; Middle Aged ; Tibial Fractures ; surgery