Objective To track and evaluate the implementation of the Radiation Shielding Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1–2007) among relevant personnel in medical radiation institutions, and to provide a scientific basis for revising the standard. Methods According to the Guidelines for Health Standards Tracking Evaluation (WS/T 536–2017) and the implementation protocol of standard evaluation, an online survey was conducted among 212 relevant workers from 146 medical radiation institutions across 18 provinces in China. The data were aggregated and analyzed with the use of Microsoft Excel 2010. Results A total of 215 questionnaires were returned, of which 212 were valid. Among the valid respondents, 77.8% believe that this standard is universally applied; 96.2% believe that this standard can meet work needs; 63.7% have participated in relevant training on this standard; 74.1% use this standard once or more per year; and 10.8% believe that this standard needs to be revised. Conclusion Medial radiation workers have a high rate of awareness of the basic information and content of the standard, but the understanding and application of the standard content need to be improved. We recommend that relevant departments further strengthen the promotion of and training on the standard, revise some content based on actual situation, and improve workers’ ability to use the standard.

Objective:To investigate the application value of the ultrasonic elastic tissue dispersion quantitative analysis technique in differentiating thyroid nodules.Methods:A total of 164 nodules in 143 patients with thyroid nodules were examined by elastography ultrasound at Sir Run Run Shaw Hospital of Zhejiang University School of Medicine from January to November 2014. Eleven parameters were obtained by the tissue dispersion quantitative analysis software. These parameters were compared between benign and malignant groups by Mann-Whitney U test. The correlations between all the parameters and the pathologic results of thyroid nodules were analyzed by Spearman analysis. The receiver operating characteristic(ROC) curve of the parameter with the highest correlation coefficient was constructed. The cut-off value was calculated. Results:All parameters except correlation (CORR) had statistically significant differences between the groups of benign and malignant thyroid nodules(all P<0.01). Moreover, except CORR, the other parameters were correlated with the pathologic results of thyroid nodules(all P<0.05), with the highest coefficient in area ration of low-strain region (%AREA)( r s=0.818). ROC curves were constructed to estimate the clinic values of %AREA in diagnosis of thyroid cancer, the area under ROC curve was 0.991 for %AREA, the cut-off point was 74.83%, the sensitivity and specifity was 98.1% and 89.8%, respectively. Conclusions:The tissue dispersion quantitative analysis technique has high value in the differential diagnosis of benign and malignant thyroid nodules.

Objective To explore the sonographic features and clinical factors associated with skip metastasis in papillary thyroid carcinoma (PTC).Methods We reviewed 276 PTC cases pathologically confirmed after operation in our hospital,analyzing the ultrasonographic features and clinical characteristics of primary site and risk factors of skip metastasis.Results The rate of skip metastasis was 16.6％,and level Ⅱ or level Ⅲ were the most common area.In univariate analysis,skip metastasis was associated with tumor location,tumor maximum size,and calcification.Multivariate analysis showed the primary tumor location in the upper portion,tumor size ≤ 10 mm,and microcalcification were independent predictive factors for skip metastasis.Conclusions In papillary thyroid carcinoma,skip metastases rate is high when primary tumor location in the upper portion,tumor size ≤ 10 mm,and there is microcalcification.

Objective The biomimetic osteochondral scaffold contained calcified cartilage layer(CCL) was fabricated using slik fibroin (SF) and hydroxyapatite (HA) for materials.To investigate effects of biomimetic osteochondral scaffold contained CCL compounding with ADSCs on regeneration of the osteochondral defect on the rabbit knee,explore the feasibility of this design as a concept of osteochondral tissue engineering.Methods We fabricated a novel biomimetic osteochondral scaffold with CCL using SF and HA by the combination of paraffin-sphere leaching and modified temperature gradient-guided thermal-induced phase separation (TIPS) technique.The pore size,porosity,and compressive modulus of elasticity of the scaffold cartilage layer and the osteogenic layer were measured by scanning electron microscopy and microscopy CT.The osteochondral defect model on rabbit bilateral knees were established,and implanted with the non-CCL group (non-CCL scaffold compounding with ADSCs) and CCL group (CCL scaffold compounding with ADSCs).At 4,8 and 12 weeks after implantation,the rabbits were euthanized,respectively.Gross observation score,histological and immunohistochemical assessment,biochemical quantitative of new osteochondral tissue,micro-CT scans for new bone,were executed.We evaluated the regeneration of osteochondral defects in each group,and verified the role of CCL in vivo.Results The biomimetic osteochondral scaffold with CCL had a consecutively overlapping trilayer structure with different densities and pore structures,including a chondral layer (top layer),intermediate layer and bony layer (bottom layer).The cartilage layer had a well-oriented microporous structure with a uniform distribution with a pore size of (112.43± 12.65)μm and a porosity of 90.25％±2.05％.The subchondral bone layer had a good three-dimensional macroporous structure,good connectivity,pore size (362.23±26.52) μm,porosity of osteogenic layer was 85.30％± 1.80％.The cartilage regeneration in CCL+AD-SCs group was better than non-CCL+ADSCs group.The content of GAG and type Ⅱ collagen in new cartilage tissue in CCL+AD-SCs group was much more than non-CCL+ADSCs group.The new bone tissue analysis and biomechanical testing had no significant differences between the two groups.Conclusion The biomimetic osteochondral SF/HA scaffold contained CCL mimics the structure of normal osteochondral tissue with good 3-dimensional pore structure and biocompatibility.The scaffold complex autologous ADSCs successfully repair osteochondral defects in rabbit knee,and the presence of CCL accelerates the growth of cartilage.

Objective To investigate the influence of dynamic mechanical stimulation on the annulus fibrosus (AF) cells seeded on silk scaffolds.Methods AF cells were isolated from rabbits and were seeded on the scaffold,then cultured for 3,7,14 days with different range of dynamic compression.Stereomicroscope and scanning electron microscope (SEM) was used to observe the surface morphology of tissue engineering annulus fibrosus cells (TE-AFs).After fixation,samples were harvested for histological staining.AF cells related extracellular matrix (ECM) was evaluated by the quantitative analysis of total DNA,proteoglycan and collagen I.The mechanical properties were compared within different groups.Results Stereomicroscope and SEM results showed that the colors of TE-AFs in all groups were deepening with time going.SEM showed cell adhesion on the scaffold and the secretion of extracellular matrix.Histological,immunohistochemical staining,biochemical quantitative analysis and total DNA content showed that the AF cells inside scaffolds could support AF cell attachment,proliferation and secretion.As a result,the compressive properties were enhanced with increasing culture time.Stereomicroscope showed that the colors of TE-AFs in all groups were deepening with time going after dynamic compression.HE staining,Safranin O staining and Type Ⅰ collagen staining showed that cell proliferation and secretion,GAG secretion and collagen secretion were increased with time going within different groups.Quantitation of GAG achieved maximum in 15％ strain group,and quantitation of collagen achieved maximum in 10％ strain group.The total DNA content achieved maximum in 5％ strain group,and compression elastic modulus achieved maximum in 15％strain goup.The height of TE-AFs did not change after mechanical stimulation for 14 days.Conclusion Suitable mechanical stimulation is a positive factor for new AF tissue engineering that will tend to the nature tissue.Excessive compression can accelerate the progress of cell apoptosis.

Objective To evaluate the strategy and clinical effects of percutaneous endoscopic surgery for cervical disc herniation.Methods Fifty-one patients with cervical disc herniation were treated with percutaneous endoscopic surgery from June 2015 to March 2017,including 32 men and 19 women,with an average age of 52.2 years (range,28-66 years).Radicular symptoms were present in all patients,while 23 patients had mild myelopathy (Nurick Grade:0-3) and 3 patients of multilevel stenosis had severe myelopathy (Nurick Grade:4-5).According to axial image of preoperative magnetic resonance imaging (MRI),31 patients had lateral herniation that was located lateral to the edge of spinal cord,20 patients had central herniation that was located within the lateral edge of spinal cord.Among them,48 patients had soft herniation and 3 patients had ossified lateral herniation combined with foraminal stenosis.All surgery was carried out under general anesthesia,while posterior and anterior percutaneous endoscopic surgeries were performed for lateral herniation and central herniation respectively.Posterior endoscopic surgery was performed with "keyhole" fenestration at "V" point (the junction of lateral edge of lamina space and inner edge of facet).Lateral edge of thecal sac and nerve root were exposed and decompressed,soft herniation was explored and removed.Anterior endoscopic surgery was performed through puncture and 4mm tube between the visceral sheath and vascular sheath.The tube was inserted through disc to the base of herniation under fluoroscopy.The herniation was removed until the dura sac was exposed and relaxed.One stage open-door laminoplasty was performed for 3 patients with severe multiple segmental stenosis and huge central herniation.The operative time and blood loss were recorded,and patients were followed-up (range,6-18 months,average 12.1 months) to evaluate the clinical efficacy.Results The mean operative time of posterior endoscopic surgery was 90 min (range,45-150 min).The nerve root was not well exposed,and the fenestration was too lateral in 1 patient,with partial relieve of symptoms;and simple nerve root decompression was performed for 3 patients of ossified herniation combined with foraminal stenosis.Herniated or sequestered nucleus pulposus was removed for 27 patients,one of them had transient paralysis ipsilateral limb and 2 of them had linkage of cerebrospinal fluid.The Visual Analogue Score (VAS) score improved form preoperative 8.9±1.6 to 0.5±0.4,and the Oswestry Disability Index (ODI) score improved form 32.8±4.2 to 2.3± 1.9 at final follow-up.For anterior percutaneous endoscopic surgery,the mean operative time was 80 min (range,45-120 min).Herniated or free nucleus was successfully removed for all patients.The thecal sac was lacerated due to unclear exposure in 1 case.The VAS score improved form preoperative 6.9±2.3 to 0.9±0.8,and the ODI score improved form 40.1±8.6 to 5.6±3.0 at final follow-up,with improvement of myelopathy at least one Nurick Grade.During follow-up,the alignment of cervical spine was well preserved without kyphosis for two groups,while the height of intervertebral space decreased with 0.4±0.3 mm and 0.9±0.6 mm in posterior and anterior surgery respectively.Conclusion Percutaneous endoscopic surgery provides minimally invasive alternatives for some cervical disc herniation with predominant radicular pain.Posterior endoscopic surgery is suitable for lateral herniation,and anterior endoscopic discectomy is suitable for some central soft herniation without obvious collapse and instability.However,the long-term results of disc space collapsed after anterior approach remains unclear.

Objective To analyze the characteristics of toxin, the PCR-ribotyping(RT) and the multilocus sequence typing(MLST) of Clostridium difficile strains isolated from China-Japan Friendship Hospital in order to provide a basis for monitoring the outbreak of nosocomial Clostridium difficile infection.Methods A total of 321 samples were collected from the patients with suspected Clostridium difficile infection(CDI) in China-Japan Friendship Hospital(CJFH) during 2012 to 2013.All Clostridium difficile strains were isolated and identified by the standard phenotypic culture method.Cytotoxicity test was performed to detect toxin B.Toxin genes (tcdA and tcdB) and binary toxin genes (cdtA and cdtB) harbored by those strains were analyzed.RT and MLST were used for homologous analysis.Clinical data of the patients were collected to analyze the isolation rate of Clostridium difficile in different populations.Results Forty-eight strains of Clostridium difficile were isolated from 46 patients with diarrhea and three of them were isolated from the same patient.The incidence of CDI among all patients, outpatients and inpatients were 14.3%(46/321), 12.8%(5/39) and 14.5%(41/282), respectively.Toxin B was detected in all of the strains as indicated by the cytotoxicity test.Strains of sequence type 1(ST1) showed the strongest cytotoxicity of all the isolated Clostridium difficile strains.Ten out of the 48 strains (20.8%) were tcdA(-)/tcdB(+) strains, which belonged to either ST37 or ST81.The results of RT and MLST were consistent in assigning the strains into nine types, in which the predominant type was ST1/RT027 accounting for 27.1% (13/48).All of the ST1/RT027 strains presented a toxin gene profile of tcdA(+)/tcdB(+) and cdtA(+)/cdtB(+).Most of the ST1/RT027 strains were isolated from the Traditional Chinese Medicine Department of Respiratory, where smallnosocomial outbreaks of ST1/RT027 strain infection might happen.Conclusion CDI diagnosed in CJFH mainly belongs to nosocomial infection.Most of the isolated strains harbor tcdA(+)/tcdB(+) genes.Surveillance for the outbreaks of CDI caused by ST1/RT027 strains over producing toxins A and B should be strengthened in hospitals.

Objective To investigate the feasibility and effects of endoscopic surgical treatment of lumbar intervertebral disc herniation associated with veitebral osteochondrosis.Methods From June 2008 to December 2015,276 cases of lumbar intervertebral disc herniation associated with vertebral osteochondrosis were treated with endoscopic surgery,including 185 men and 91 women,with an average 39.2 years old (range,16-65 years old).The involved level included L2.3 in 2 cases,L3.4 in 9 cases,L4,5 in 126 cases and L5S1 in 139 cases.On preoperative axial CT,the diameter of ossification was more than half of the transverse or sagittal diameter of the spinal canal in 89 cases,and no more than half of the transverse and sagittal diameter of the spinal canal in 187 cases.All patients were operated on the side with serious symptom,181 cases were operated with mobile microendoscopic discectomy (MMED),and 95 cases were operated with percutaneous endoscopic surgery,including percutaneous transforaminal endoscopic discectomy (PTED) in 61 cases and the percutaneous interlaminar endoscopic discectomy (PIED) in 34 cases.The operation and complications were analyzed.Results The soft herniation,broken disc material and the periphery of compressing ossification were removed under the endoscope in all cases,until the nerve was well decompressed.However,the ossification was not complete resected.Dural sac tear occurred in 3 cases of MMED.In the early stage of PTED,2 cases converted to MMED because of intraoperative pain and difficulty,and one case had exiting nerve root injury.At the final follow-up of 12-60 months (average,20.6 months),visual analogue scale decreased from preoperative 8.5±1.2 to 1.0±0.9,Oswestry disability index decreased from preoperative 40.2±8.6 to 3.1±3.0.According to Macnab scale,the results were excellent in 89,good in 154 cases,moderate in 33 cases.Conclusion For most lumbar intervertebral disc herniation associated with vertebral osteochondrosis,good results can be achieve by removal of herniated and broken intervertebral disc and decompression of nerve with endoscope.Therefore,we speculate that the soft disc herniation and spinal stenosis are main pathogenic factors,and that the complete resection of ossification is not needed.

Objective: To investigate the occurrence of occult carcinoma in contralateral lobes based on the ultrasonic features of unilateral papillary thyroid carcinoma. Methods: The study included 202 consecutives cases of unilateral papillary thyroid carcinoma with benign nodules in the contralateral lobe identified by preoperative ultrasound or fine-needle aspiration from June 2014 to December 2015. All patients received total thyroidectomies, and with postoperative pathological examination they were divided into two groups, one including 60 cases with positive occult cancer and another one consisting of 142 cases with negative occult cancer. Univariate and multivariate analyses were performed to analyze the sonographic features of unilateral papillary thyroid carcinoma relevant to the occurrence of occult carcinoma in the contralateral nodules. Results: Univariate analysis indicated occult carcinoma in the contralateral lobes was associated with Hashimoto's thyroiditis(χ²=3.955, P=0.047), unclear border (χ²=4.375, P=0.036)and multifocality in the ipsilateral(χ²=7.375, P=0.007), but not with tumors maximum size, location, A/T, shape, internal structure, internal echo, acoustic halo, calcification, capsular invasion and blood flow signal in the lobe with carcinoma on another side. Multivariate analysis showed unclear border (OR=2.727, P=0.010) and multifocality in the ipsilateral(OR=2.807, P=0.005)of carcinoma were independent predictive factor for contralateral occult PTC. Conclusions Unclear border and multifocality of PTC in the ipsilateral were closely relevant to the occurrence of occult carcinoma in the contralateral nodules.

Objective To establish an animal model of annulus fibrosus (AF) partial defect for the repairing of interver?tebral disc (IVD) defect. Methods Image J 1.46r software was used to measure the T12/L1-L6/S1 intervertebral height in ovine lumbar spine X-ray films. AF thickness was measured by axial split disc. A 11 blade was used to make a trapezoid de?fect of upper bottom 3 mm, lower bottom 5 mm, height 5 mm and thickness 3 mm, whose lower bottom toward the nucleus pulposus (NP) in the left front of ovine lumbar IVD in vitro. The minimally invasive lateral approach was used to make the same type of trapezoid defect in the left front of the ovine lumbar IVD in vivo. The trapezoidal defect length of the axial divid?ing disc was measured, AF and a small amount of NP from trapezoidal defect in IVD were weighed, and the production of trapezoidal defect in IVD was evaluated. Results The lumbar intervertebral space height of ovine was (4.45 ± 0.28) mm. There were significant differences in the thickness of AF (4.08±0.50) mm , thickness (3 mm) and height (5 mm) of trapezoidal defect (P<0.05), respectively. There were no significant differences in trapezoidal defects in ovine lumbar IVD in vitro on the upper bottom (3.03 ± 0.09)mm, the lower bottom (5.03 ± 0.09) mm, the height (4.97 ± 0.10) mm, the thickness(3.02 ± 0.06) mm and the trapezoidal defect predetermined value on the upper bottom 3 mm, the lower bottom 5 mm, the height 5 mm and the thickness 3 mm (P>0. 05). The weights of the AF and NP taken out from ovine lumbar IVD in vitro and in vivo were (0.162 ± 0.011) g and (0.166 ± 0.014) g, and there was no significant difference between them (P > 0.05). Conclusion Through the operation of minimally invasive lateral approach, the method of making a trapezoidal defect in the experiments can establish animal model of AF partial defect, which meets the requirements for the repairing of IVD defect, and is simple, safe and reliable.