Objective To study the maintenance of BJ-6B accelerator. Methods Analyzed retrospectively the maintenance record of BJ-6B accelerator, including phenomena, causes and handle from 2002 to 2009. Results In 231 records, there were motion-controlling 64, hand-controlling-pendant 20.modulator 41, anti-peak overload 36, charging overload 5. Flatness 7, mechanical 21, digital-display 20,others lie in magnetron power, water-cooling system, light-indicator system, dose-monitor system and wedge system. Motion-controlling system is the highest among those, followed by high-voltage modulator and mechanical system. Conclusions The down time for BJ-6B accelerator is low because of its perfect technology. To keep its stability in clinic, the hospital authorities should emphasize training of engineer for improving their maintenance ability. The engineer must be familiar with the circuit diagram, check the electric wire and machine unit on time and prepare unit for maintenance. The temperature and humidity in machine house must be controlled on demand. The engineer must pay attention to machine parameters when beam is on for avoiding the spark's damage to magnetron and accelerating-tube

Objective To investigate the expression of RECK and MMP-9 in pancreatic cancer and to explore the relationship between RECK, MMP-9 expression and the clinicopathological characteristics.Methods PV6000 immunohistochemical method was used to detect the expression of RECK and MMP-9 in 28 cases of pancreatic cancer and 10 cases of normal pancreatic tissue. All the statistical analyses were performed by using SPSS 13.0 statistical software to determine the relationship between RECK, MMP-9 expression and the clinicopathological characteristics. Results The overall positive rate of RECK espression was 46.43% (13/28)in pancreatic cancer, which was significantly lower than that in normal pancreatic tissue (90%, 9/10). The positive rate of RECK espression in Ⅰ + Ⅱ clinical stage (75.0% ,9/12) was significantly higher than that in Ⅲ + Ⅳ stage (25.0%, 4/16 P < 0.05 ). The positive rate of RECK expression in cases without distant metastases (60.0%, 12/60) was significantly higher than that in cases with distant metastasis (12.5%, 1/8,P<0.05). The overall positive rate of MMP-9 was 75% (21/28) in pancreatic cancer, and 20% (2/10) in normal pancreatic tissue. The comparison between these two groups indicated a significant difference (P <0.01 ). The positive rate of MMP-9 in Ⅰ + Ⅱ clinical stage(50.0% ,6/12) was significantly lower than that in Ⅲ + Ⅳ stage (93.8,15/16, P < 0.05). The positive rate of MMP-9 in well differentiation group(33.3%,1/3 ) was significantly lower than that in poor differentiation group ( 100%, 12/12 ,P < 0. 01 ). The expressionof RECK was negatively correlated with the expression of MMP-9 ( r = - 0. 536, P < 0.01 ). Conclusions RECK is lowly expressed in pancreatic cancer, but MMP-9 is highly expressed. RECK and MMP-9 may serve as important markers in the evaluation of tumor stage.

Objective To study the impact of main source voltage fluctuation on dose rate and dose delivery accuracy of BJ-6B accelerator. Methods The accelerator was calibrated by a voltage regulator at an output voltage of 332 V. The main source voltage fluctuation was simulated by changing the output of voltage regulator within the range of 321 - 338 V. The change of dose rate was recorded. Using a water phantom, each absorption dose was measured five times and averaged along the central beam axis at the depth of 1.5 cm, 5 cm and 10 cm, respectively, with the conditions of monitor unit: 100 MU ,field: 10 cm× 10 cm and SSD = 100 cm. The impact of voltage fluctuation on dose rate and dose delivery of BJ-6B accelerator was analyzed. Results Voltage fluctuation had an significant effect on dose rate. In a certain range, dose rate and absorption dose at different depths increased as the output voltage increased. Conclusions It is essential to equip the BJ-6B accelerator with a high accurate voltage stabilizer, and the voltage stabilizer must be adjusted to its highest accuracy.

Objective To study the effect of CT scanning condition on the target position coordinate with WIMRT radiotherapy planning system using the" Z" form localizing frame. Methods The whole Head Phantom containing three metal targets was scanned under the following conditions: localizing frame transver-sally tilting, CT gantry tilting and localizing frame axially tilting. Then the three target coordinates were com-puted respectively and compared with those under the standard condition. Results The height and width of coordinate under the localizing frame transversally tilting condition deviated from those under the standard scanning condition,which was in an angle dependent manner. On the other hand ,a tendency was shown that the greater the absolute height value of the targets coordinate, the greater the width value deviation. And so was the relation between the absolute width value of the coordinate and height value deviation. If CT gantry angle was not zero degree or localizing frame axis is not in the same line with the CT bed moving direction, the calculated longititude value of the targets coordinate was mainly affected. Conclusions CT scanning must be performed strictly under the standard localizing scanning condition by a proficient physicist.

We investigated the prevalence and genetic variation of porcine pseudorabies virus(PRV)in Hunan Province.A total of 18 861 serum samples and 1 725 suspected PRV-infected tissue sam-ples were collected from Hunan Province from 2021 to 2022.ELISA and qPCR assays were used to detect PRV-gE antibodies in serum samples and the PRV-gE nucleic acids in tissue samples.The positive rates of samples in different years and seasons were analyzed correspondingly.Moreover,the gC gene sequences of 15 PRV-positive samples were amplified,sequenced,and analyzed.The results showed that 2 004 serum and 56 tissue samples tested positive,with an average positive rate of 10.74％and 3.25％,respectively.The sequence analysis showed that the nucleotide and ami-no acid sequence identities of the gC gene among 15 PRV-positive samples were 98.4％-100.0％and 98.8％-100.0％,respectively.Further genetic evolution analysis showed that 13 PRV strains belonged to the same branch with the PRV variants,while two strains were clustered into the same branch with the classical PRV strains.The above results indicate that PRV remains widely prevalent in different regions of Hunan Province,and the variant strain is the dominant epi-demic subtype,which provided a scientific basis for exploring the epidemiological characteristics of PRV and the development of vaccines against PR in Hunan Province.

Objective:To analyze the detection strategy and basic detection situation of markers of infectious diseases transmitted by transfusion in blood testing laboratories of blood stations in China.Methods:Based on the data of practice comparison working party of Blood Stations in Mainland of China from 2017 to 2021, the data on the testing strategies and the basic detection information of the markers for the transmission of infectious diseases through transfusion in the member laboratories of the practice comparison working party of Blood Stations in Mainland of China from 2017 to 2021 were collected, and the situation of the selection for testing markers, testing strategy and the testing method and other relevant aspects were sorted out and analyzed by charts.Results:The selection of the testing markers was consistent, but HTLV testing item was added in some member laboratories. The detection strategy of using two ELISA reagents and one nucleic acid testing (NAT) reagent simultaneously was adopted in 47 member blood stations; 3) NAT method was dominated by mini pool-NAT in member laboratories. The number of members adopting mini-pools of 8 (MP8)-NAT decreased from 17 in 2017 to 14 in 2021, while the number of members adopting mini-pools of 6 (MP6)-NAT increased from 13 in 2017 to 22 in 2021; Roche NAT system accounted for the largest proportion.Conclusions:In order to ensure blood safety and avoid missing detection, the blood stations still adopt the detection strategy of using two ELISA reagents and one nucleic acid testing (NAT) reagent simultaneously; Meanwhile, in order to increase the NAT positive rate, the proportion of mini pool-NAT mainly decreased year by year despite its dominating role, while the proportion of individual donation-NAT increased year by year; NAT method is transiting from mini-pools of 8 (MP8) to mini-pools of 6 (MP6); The proportion of imported NAT system used in NAT laboratory is relatively large.

Objective:To investigate and analyze the current situation, screening, clinical characteristics, prevention and treatment of bleeding esophageal varices in cirrhotic patients with portal hypertension in Tibet region.Methods:Clinical data of cirrhotic patients with portal hypertension through March 2017 to February 2020 from Tibet region were collected and analyzed retrospectively.Results:511 cases with liver cirrhosis were included in the study, of which 185 cases (36.20%) had compensated cirrhosis and 326 cases (63.80%) had decompensated cirrhosis. Further analysis of the etiological data of liver cirrhosis showed that 306 cases (59.88%) were of chronic hepatitis B, 113 cases (22.11%) of alcoholic liver disease, and 68 cases (13.31%) of chronic hepatitis B combined with alcoholic liver disease. Among patients with compensated liver cirrhosis, 48 cases (25.95%) underwent endoscopic examination of which 33 diagnosed as high-risk variceal bleeding. However, none of these 33 cases had received non-selective β-blocker therapy, and only four patients had received endoscopic variceal banding therapy. Among patients with decompensated liver cirrhosis, 83 cases (25.46%) had a history of upper gastrointestinal bleeding, 297 cases (91.10%) had ascites, 23 cases (7.05%) had hepatic encephalopathy, and 3 cases (0.92%) had hepatorenal syndrome. Among the patients with a history of upper gastrointestinal bleeding, 42 cases (50.60%) had received secondary preventive treatment for bleeding esophageal varices, including 39 cases of endoscopic treatment, 1 case of endoscopic combined drug treatment, 3 cases of interventional treatment, and 2 cases of surgical treatment.Conclusion:Chronic hepatitis B and alcoholic liver diseases are the main causes of liver cirrhosis in Tibet region. Moreover, this region lacks screening, prevention and treatment for bleeding esophageal varices in cirrhotic patients with portal hypertension. Therefore, it is necessary to increase the screening of high-risk groups to prevent and improve the first-time bleeding, and promote multidisciplinary team to prevent and treat re-bleeding.

Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.
Genome, Viral ; Haplotypes ; Humans ; Mutation ; Open Reading Frames ; Phylogeny ; SARS Virus ; genetics

We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.
Base Sequence ; China ; Cluster Analysis ; Gene Components ; Genetic Variation ; Genome, Viral ; Genotype ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; Sequence Analysis, DNA ; Severe Acute Respiratory Syndrome ; genetics

ObjectiveTo explore the effect of Anmeidan on the sleep quality and serum levels of brain-derived neurotrophic factor （BDNF）， glial fibrillary acidic protein （GFAP）， and irisin in the patients with chronic insomnia. MethodA multicenter， randomized， double-blind， placebo-controlled clinical study was carried out， including 480 patients with chronic insomnia （deficiency syndrome） in Wuhan （Hubei）， Guangzhou （Guangdong）， and Lanzhou （Gansu）. They were randomized into an observation group and a control group at a ratio of 1∶1. The observation group was orally administered with Anmeidan granules at a dose of 11 g， 3 times per day， and the control group with Anmeidan simulant at a dose of 11 g， 3 times per day， Both groups of patients received sleep education after enrollment. After 4 weeks of medication， the Athens insomnia scale （AIS） scores， Spiegel scale scores， and serum levels of BDNF， GFAP， and irisin were compared between the two groups as well as between before and after treatment. ResultA total of 480 adult patients with chronic insomnia were enrolled in this study， with 64 patients falled off. Finally， the 415 patients were included in the analysis， including 213 patients in the observation group and 202 patients in the control group. There was no difference in age or sex between the two groups of patients. Compared with before treatment， the treatment in both groups decreased the AIS and Spiegel scores （P<0.01）. After treatment， the observation group had lower AIS and Spiegel scores than the control group （P<0.01）. The treatment in the observation group slightly lowered the level of BDNF， elevated the level of irisin （P<0.05）， and lowered the level of GFAP （P<0.05） in the serum. After treatment， the observation group showed higher level of irisin （P<0.05） and lower levels of BDNF and GFAP in the serum than the control group. ConclusionAnmeidan may improve the sleep quality of patients with chronic insomnia by elevating the irisin level and lowering the GFAP level in the serum.