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.

OBJECTIVETo study the effect of lycopene on red blood cell and the level of blood lipid.

METHODSAccording to the level of serum total cholesterol and weight, forty-eight adult male SD rats were divided randomly into six groups: normal control (group A), fed by normal feed; hyperlipidemia group (group B): fed by high fat diet; positive control group (group C): fed by high fat diet plus 10 mg * kg(-1) * d(-1) fluvastatin sodium; lycopene groups: fed by high fat diet plus 11 (group D), 22 (group E), 44 mg * kg(-1) * d(-1) (group F) lycopene through gavage, respectively. For all six groups, the level of serum total cholesterol (TC) and total triglyceride (TG) were measured at the end of 0, 1, 3 weeks of the study by taking samples from tail vein. At the end of the experiment, RBC and HGB were measured.

RESULTSAfter the rats were fed with high-fat feed for a week, models of hyperlipidemia rats were established. At the end of 3 weeks, TC of group A, B, C, D, E and F were (1.31 +/- 0.05), (19.40 +/- 0.54), (4.66 +/- 0.07), (7.18 +/- 0.06), (5.30 +/- 0.28), (4.49 +/- 0.23) mmol/L (F = 4395.72, P = 0.00), respectively;and TG were (0.42 +/- 0.01), (2.29 +/- 0.42), (0.69 +/- 0.03), (1.10 +/- 0.05), (0.63 +/- 0.02), (0.62 +/- 0.04) mmol/L (F = 127.26, P = 0.00), respectively; HGB were (143.13 +/- 6.33), (112.63 +/- 2.56), (124.75 +/- 3.62), (124.63 +/- 7.78), (132.38 +/- 6.41), (142.13 +/- 5.54) g/L (F = 34.14, P = 0.00), respectively; RBC were (6.75 +/- 0.60) x 10(12)/L, (5.08 +/- 0.75) x 10(12)/L, (7.14 +/- 0.82) x 10(12)/L, (5.94 +/- 1.09) x 10(12)/L, (6.18 +/- 0.36) x 10(12)/L and (7.31 +/- 0.58) x 10(12)/L (F = 10.35, P = 0.00), respectively.

CONCLUSIONLycopene have some protective effects on red blood cells of the hyperlipidemic rats by regulating the blood lipid and antioxidant.

Animals ; Carotenoids ; pharmacology ; Cholesterol ; blood ; Cholesterol, LDL ; blood ; Erythrocytes ; drug effects ; Hypercholesterolemia ; blood ; Lipids ; blood ; Male ; Rats ; Rats, Sprague-Dawley ; Triglycerides ; blood

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 study the clinicopathologic features, immunophenotype and differential diagnosis of sclerosing epithelioid fibrosarcoma (SEF).

METHODSEight cases of SEF were investigated by light microscopy and immunohistochemistry.

RESULTSThere were five males and three females. Clinically, most patients presented as a slowly growing mass. Six tumors were located in the extremities or limb girdles, and two in the trunk. Grossly, most lesions were relatively well-circumscribed with a nodular or lobulated appearance. They ranged from 2.0 to 10.5 cm in size (mean 6 cm). On sectioning, they had a gray-whitish cut surface and were firm in consistency. Microscopically, the tumors were composed of uniformly round or polygonal epithelioid cells with clear to eosinophilic cytoplasm. The tumor cells were arranged predominantly in single strands or cords and embedded in a heavily hyalinized matrix. In some areas, nests, sheets, acini or alveolar structures were also noted. Nuclei atypia and brisk mitotic activity was not evident. The mitotic count measured less than 1 per 10 high power fields. However in two cases, focal areas exhibited increased cellularity, nuclei atypia and higher mitotic activity, resembling conventional fibrosarcoma. Immunohistochemically, the tumor cells showed diffuse and strong positivity for vimentin and focal or weak positivity for EMA. There was no expression for AE1/AE3, S-100 protein, HMB45, alpha-SMA, MSA, desmin, CD34, bcl-2, CD30 and LCA. Follow-up information in six patients revealed local recurrence in 3 cases and lung metastasis in 1 case.

CONCLUSIONSSEF is a rare variant of fibrosarcoma. Despite the relatively bland appearance and low mitotic activity, the tumor is capable of local recurrence and distant metastasis. Thus, it should be considered and treated as a low to intermediate grade sarcoma. SEF needs to be differentiated from a variety of benign or malignant tumors exhibiting epithelioid features and sclerotic stromal response.

Adult ; Diagnosis, Differential ; Extremities ; Female ; Fibrosarcoma ; metabolism ; pathology ; secondary ; Follow-Up Studies ; Humans ; Lung Neoplasms ; secondary ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Neoplasm Recurrence, Local ; Soft Tissue Neoplasms ; metabolism ; pathology ; Vimentin ; metabolism