In this study,the loop-mediated isothermal amplification(LAMP)method was used to develop a rapid and simple detection system for porcine circovirus type 2(PCV2).According to the PCV2 sequences published in GenBank,multiple LAMP primers were designed targeting conserved sequences of PCV2.Using the DNA extracted from PCV2 isolates HUN-09 and SD-09 as the template,LAMP reactions in a PCV2 LAMP system was performed,the amplification products were detected by adding SYBR Green I and could be observed directly by the naked eye.The results showed highly-efficient and specific amplification in 30 min at 63℃ with a LAMP real-time turbidimeter.Furthermore,PCV2 DNA templates,with a detection limit of 5.5×10-5ng of nucleic acid,indicated that this assay was highly sensitive.The results obtained with the naked eye after SYBR Green I staining were consistent with those detected by the real-time turbidimeter,showing the potential simplicity of interpretation of the assay results.The LAMP assay appeared to have greater accuracy than PCR and virus isolation for the analysis of 18 clinical samples.In addition it offers higher specificity and sensitivity,shorter reaction times and simpler procedures than the currently available methods of PCV2 detection.It is therefore a promising tool for the effective and efficient detection of PCV2.

A real-time monitoring reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the sensitive and specific detection of prototypic,prevalent North American porcine reproductive and respiratory syndrome virus (PRRSV)strains.As a higher sensitivity and specificity method than reverse transcription polymerase chain reaction (RT-PCR),the RT-LAMP method only used a turbidimeter,exhibited a detection limit corresponding to a 10-4 dilution of template RNA extracted from 250 μL of 105 of the 50% tissue culture infective dose (TCID50) of PRRSV containing cells,and no cross-reactivity was observed with other related viruses including porcine circovirus type 2,swine influenza virus,porcine rotavirus and classical swine fever virus.From forty-two field samples,33 samples in the RT-LAMP assay was detected positive,whereas three of which were not detected by RT-PCR.Furthermore,in 33 strains of PRRSV,an identical detection rate was observed with the RT-LAMP assay to what were isolated using porcine alveolar macrophages.These findings demonstrated that the RT-LAMP assay has potential clinical applications for the detection of highly pathogenic PRRSV isolates,especially in developing countries.

OBJECTIVE:To provide reference for formulating the policy of promoting the popularization and application of es-sential medicines in second grade or third grade medical institutions. METHODS:Drug purchase and warehousing data was collect-ed from 31 second grade or third grade medicinal institutions in Nanjing during Jan. 2012-Dec. 2015. Excel 2010 and SPSS 20.0 software were used to summarize and analyze statistically the purchase amount of allocation quantity of essential medicines. RE-SULTS:The proportion of essential medicine purchase amount in total medicine purchase amount during 2012-2015 were 18.33%, 18.56%,17.19%,17.53% in 31 medicinal institutions (calledthe ratio of essential medicine purchase amountfor short);the proportion of national essential medicine purchase amount in essential medicine purchase amount(calledthe ratio of essential medi-cine purchase amountfor short)were 31.14%,29.40%,25.69%,25.79%,respectively. The number of generic names for allocat-ed essential medicines were 189.84,205.58,210.26,206.65,respectively. The ratio of essential medicine purchase amount and the ratio of essential medicine purchase amount in 2014 were decreased significantly,compared to in 2013(P<0.05). The number of generic names for allocated essential medicines in 2013 was increased significantly,compared to in 2012 (P<0.05). The ratio of essential medicine purchase amount in second grade medical institutions was significantly higher than third grade medical institu-tions,the ratio of essential medicine purchase amount in general hospital was significantly higher than special hospital;the number of generic names for allocated essential medicines was significantly higher than TCM hospital and special hospital;the ratio of es-sential medicine purchase amount in second grade medical institutions with community health service center in subjection to them was significantly higher than those without community health service center in subjection to them;there was statistical significance (P<0.05). There was negative correlation between the ratio of essential medicine purchase and total purchase amount of medicine in general hospitals(P<0.05). There was positive correlation between the number of generic name of allocated essential medicines and the number of generic name of all medicines in 31 medical institutions(P<0.05). CONCLUSIONS:The ratio of essential med-icine purchase amount and national essential medicine purchase amount,the numbers of generic names of essential medicines were very different and low in these hospitals during 2012-2015. Just one or two had met the requirements of the Jiangsu provincial health and family planning commission. The grade,type,medicine purchase and allocation scale,administering community health service center all influence the purchase and allocation of essential medicines.

Objective To compare the effect of three cryoprotectants on vitrification-cryopreservation of C57BL/6J mouse epididymis.Method Epididymises from 6-8-week old male C57BL/6J mice (age) were cryopreserved using DMSO, PROH and R18S3 cryoprotectant solution and thawed , respectively.The morphology of sperm from thawed epididy-mis, the rate of post-thawing survival and reproductive capacity were determined to evaluate the freezing efficiency of the three cryoprotectants .Results The sperms from thawed epididymis of the three groups were all well-preserved structural-ly.The survival rate of sperms was 88.17%, 61.17% and 16.83% in the PROH, DMSO and R18S3 cryoprotectant solu-tions, respectively, and there were significant differences between the three cryopreservation groups (P<0.05 for all). The number of pups from the DMSO , PROH and R18S3 groups were 13, 8 and 17 mice after ICSI and embryo implantation , respectively.Conclusions All the three cryoprotectants DMSO , PROH and R18S3 solutions are suitable for vitrification-cryopreservation of C57BL/6J mouse epididymis.But PROH is the preference of these cryoprotectant solutions .

Objective To explore the Monte Carlo calculation methods for the absolute dose calibration and output factor of 6 MV flattening-filter ( FF) and flattening-filter free ( FFF) photon beams based on TrueBeam accelerator .Methods The BEAMnrc code was used to model the LINAC head of FF and FFF modes.The BEAM_up covers the components from the target to the monitor chamber , and BEAM_down includes the structures beneath the chamber , the dose deposit to the monitor chamber contributed by the incidence electrons and scattered particles from the secondary collimators were calculated respectively .The incidence electron-induced dose at certain depths on the central axis were simulated by means of the DOSXYZnrc code .By means of dose calibration equation , the calibration factor for the standard field (10 cm ×10 cm) and the output factors for various fields (1 cm ×1 cm-40 cm ×40 cm) were computed respectively .Results For the 6 MV FF and FFF beams under the standard 10 cm ×10 cm field, 1 MU equals to 7.747 ×1013 ±3.099 ×1011 and 3.248 ×1013 ±1.624 ×1011 electrons to the target , respectively , which deposited 21.53 and 35.01 cGy to the monitor chamber of the virtual accelerator respectively .The difference between the simulated and calculated output factors were 0.72%±1.4%and 0.56%±0.78%for FF and FFF , respectively .Conclusions The model generated and measured output factors agree well , indicating the good accuracy of the dose calculation by the model , which would provides basis for further clinical dosimetric studies .

Objective To compare the effects of different transplantation sites on the outcome of testicular grafts in mice, and to provide a basis for development and application of this technique in relevant research .Method 5-day old and 4-week old SPF male C57BL/6J mice were used in this study .Three groups of testicular transplantation , i.e.dorsal subcutaneous transplantation ( 5 mice, 40 testes ) , transplantation inside the testicular tunica albuginea ( 6 mice, 12 testes), and were subrenal capsule transplantation (10 mice,15 testes) groups were set up for evaluating the effect of transplantation site on the outcomes in mice .Sham operation (4 mice) and castration (4 mice) groups were also used in this study.The mice were sacrificed at 8 weeks after transplantation and the transplanted testes were collected for analysis of their weight, transplant survival, weight gain, and germ cell differentiation.Results There were significant differences of the testicular germ cell differentiation in different transplantation groups .The germ cell differentiation was best in the in-tra-tunica albuginea transplantation group , and were similar to that in the sham operation group .The germ cell differentia-tion rate was 100%in the intra-tunica albuginea transplantation group , 29.2% in the subcutaneous transplantation group and 0%in the subrenal capsule transplantation group .Conclusions Transplantation beneath the testicular tunica albug-inea is the most favorable site for germ cell differentiation , and dorsal subcutaneous transplantation is an alternative choice . Subrenal capsule transplantation is not appropriate for preservation of male reproductive organs in mice .

Objective To compare the performances of four commercially available LINAC daily QA instruments.Methods The dosimetric stability of a LINAC including central axis output,flatness and symmetry were verified and fine-tuned using a 3-dimensional water phantom,dosimeters and ionization chambers.The baseline of the four instruments including LINA-C,QUICK-C,BEAM-C and QA3 were set thereafter.Daily measurements of LINAC were conducted with these instruments respectively and the results were compared.Arbitrary errors (CAX and SYM) beyond TG-142 tolerances were introduced to the LINAC to test the sensibilities of each instrument in detecting these changes.Results Relative to the baseline that were measured by the 3-dimensional water phantom and dosimeters,the results monitored by the four instruments were comparable.The maximum disparities of the CAX,FLAT,and SYM were 0.5％ (LINA-C),-0.45％ (QUICK-C),and 0.5％ (BEAM-C),respectively.All checkers detected the known errors successfully.Conclusions The stabilities of all the four evaluated instruments met the requirements of daily QA for LINAC.LINA-C verifies CAX only.QUICKE-C,BEAM-C and QA3 can be used to perform all the daily QA protocols as suggested by AAPM TG 142 report.They also provide unique additional functions.The setup of baseline determines if the morning checkers could measure the LINAC dosimetric parameters correctly.When an error is alarmed by the morning checker,it is recommended to verify the performance of the instrument first rather than recalibrating the LINAC immediately.

Objective:To solve the problems in intensity-modulated radiation therapy (IMRT) planning, such as large labor cost and high dependence on the experience of physicists and great inconsistency in the quality of plan, and to discuss an unsupervised automatic treatment planning procedure of IMRT.Methods:The eclipse scripting application programming interface (ESAPI) within the Eclipse treatment planning system (TPS) 15.6 and optimization parameters tree search algorithm (OPTSA) were used to emulate and realize the whole planning process. Interacted with the TPS through ESAPI, relevant dosimetric parameters were input and output. The OPTSA evaluated the plan qualities based on dosimetric parameters of the targets and organs at risk (OARs) and iteratively adjusted the optimization objective parameters to achieve a progressively improving IMRT plan. In order to verify the effectiveness of the automatic planning, twenty historical rectum cancer cases were selected from the clinical database, and the dose distribution and specific dosimetric parameters were compared between the plans generated by the OPTSA and the manual plans under the same constraints.Results:All the auto plans have met clinical requirements. Furthermore, 90% and 10% of the auto plans were deemed as clinically improved and equally compared with the manual plans, respectively. The average CI for the PTV was 0.88 and 0.80 for the auto and manual plans respectively. Compared with the manual plans, the mean doses of all the OARs in the auto plans were reduced by 11% in average. The average elapsed time of automatic planning and manual planning was (28.15±3.61) and (36.7±4.6) min, respectively.Conclusions:The plans created by the proposed algorithm have been shown to be at least as good as the manual plans. In addition, this method can shorten the labor time in plan designing while ensuring the plan quality and consistency of the plan.

Objective To quantify the correlations between Elekta XVI cone beam CT dose and various scanning protocols,providing mathematical models to assess the protocol-dependency of imaging dose during imnage guided radiotherapy.Methods Based on standard protocols and various combinations of kVp and mA on an XVI mounted on an Elekta Versa HD accelerator,the air KERMA was measured at various positions in a standard PTW CTDI body phantom using calibrated PTW 30009 kV chamber and UNIDOS webline electrometer.Weighted CT dose index (CTDIw) was computed thereafter.SigmaPlot 10.0 was used to fit the measurements against mA and/or kVp yielding empirical functions.Results Under standard protocols,the CTDIw of Varian OBI was only 11.23％ (chest) and 9.15％ (pelvis) of Elekta XVI.Using the default and other 4 investigated kVp values,the central and peripheral KERMA were both proportional to mA,and vet the slope value a varied dramatically from 0.479 to 6.679.Major affecting factors included kVp settings,measurement locations,and dosimetric mnetrics,etc.None linear regressions were used to fit kVp against KERMA at various locations and CTDIw (R2 ＞ 0.997).The differences between all coefficients were statistically significant (P ＜ 0.05).The impact of changing both mA and kVp on the dose to phantom center can be described as mGy =(5.917-0.197 ×kVp+0.002 × kVp2-5.063 × 10-6 × kVp3) × mA.Conclusions Imaging dose of Elekta XVI is strongly dependent on scanning paraneters.The proposed mathematical models can be used as efficient and robust indicators of such dependency.

Objective To compare the impact of immobilization base plates composed of 7 types of materials on the MR-simulation imaging quality used for radiotherapy,aiming to provide reference data for clinical applications.Methods Using identical T1 and T2 sequences of Siemens MR-simulator,the MR images of ACR Large Phantom were acquired on the Orfit carbon fiber laminate,polycarbonate (PC),high precision base plate (HP),Jinan Huayuxin BR,WR,KP and SP materials,respectively.The imaging quality without any plate was used as the baseline data.The following metrics were compared:1.High-contrast spatial resolution:the sharpness of 3 pairs of hole arrays was observed,which represented resolutions of 1.1 mm,1.0 mm and 0.9 mm on the LR and AP directions;2.Image intensity uniformity in terms of percent integral uniformity (PIU):PIU =100× [1-((high-low)/(high +low)];3.Low-contrast resolution:distinguishable spokes representing resolutions of 5.1％,3.6％,2.5％ and 1.4％ were recorded.According to ACR recommendations,high-contrast resolution of 1.0 mm,PIU of T1WI and T2＞82％and low-contrast spoke difference＜3 were considered as clinically acceptable.Results High-contrast T1WI and T2WI resolutions of no plate,PC plate,HP plate and KP material were all 0.9 mm,and those of the remaining materials were =worse than 0.9 mm.The T1WI and T2WI PIU of no plate was＞87％,and the PIU of carbon fiber plate was reduced by＞ 25％.The PIU decrease of remaining materials was within ±4％.Except the carbon fiber plate,the low-contrast spokes of the remaining materials were within ±3 compared with the reference.Conclusions In clinical settings,carbon fiber plate exerts the most significant effect upon the MR-simulation imaging quality,which is unsuitable for MR simulation.Imaging quality of PC and HP plates are consistent with that of no plate.BR and KP materials exert slight effect upon MR signal.The remaining materials are of potential values for the manufacture of immobilization devices and accessories.