Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.

Porcine arthritis,one of the common chronic diseases in large-scale pig farms,can signifi-cantly reduce the production performance of meat pigs.In this study,a strain of Haemophilus pa-rasuis(HPS)was isolated from the joint fluid of a lame pig.The HPS was analyzed in terms of se-rotypes,virulence genes,and resistance genes.Additionally,it was treated with sensitive antibiotics to provide a theoretical basis for the comprehensive prevention and treatment of arthritis in meat pigs in future production settings.A strain of HPS type 14 was isolated from the joint fluid of dis-eased pigs.The HPS isolate demonstrated sensitivity to β-lactams and tetracyclines,while florfeni-col and polymyxin effectively inhibited its growth at low concentrations.However,the bacteria ex-hibited resistance to sulfonamides and ciprofloxacin.The treatment of affected pigs with clinical ar-thritis using doxycycline and enrofloxacin injections proved effective.Compared to the infected group,in which the sick pigs experienced difficulty flexing their carpal and tarsal joints and exhibi-ted significant lameness,the pigs in the treatment group showed marked improvement.Their joints were only slightly swollen,and the clinical symptoms of arthropathy were alleviated.

Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.

Porcine arthritis,one of the common chronic diseases in large-scale pig farms,can signifi-cantly reduce the production performance of meat pigs.In this study,a strain of Haemophilus pa-rasuis(HPS)was isolated from the joint fluid of a lame pig.The HPS was analyzed in terms of se-rotypes,virulence genes,and resistance genes.Additionally,it was treated with sensitive antibiotics to provide a theoretical basis for the comprehensive prevention and treatment of arthritis in meat pigs in future production settings.A strain of HPS type 14 was isolated from the joint fluid of dis-eased pigs.The HPS isolate demonstrated sensitivity to β-lactams and tetracyclines,while florfeni-col and polymyxin effectively inhibited its growth at low concentrations.However,the bacteria ex-hibited resistance to sulfonamides and ciprofloxacin.The treatment of affected pigs with clinical ar-thritis using doxycycline and enrofloxacin injections proved effective.Compared to the infected group,in which the sick pigs experienced difficulty flexing their carpal and tarsal joints and exhibi-ted significant lameness,the pigs in the treatment group showed marked improvement.Their joints were only slightly swollen,and the clinical symptoms of arthropathy were alleviated.

Objective To systematically retrieve,evaluate and integrate the best evidences on the early fluid resuscitation management in the patients with acute pancreatitis(AP)at home and abroad to provide ref-erence for clinical decision.Methods The related evidences on the early fluid resuscitation management in the AP patients were retrieved by computer from the databases of BMJ Best Practice,Up To Date,JBI,National Institute for Health and Care Excellence,Registered Nurses Association of Ontario,Guideline International Network,Scottish Intercollegiate Guidelines Network,International Association of Pancreatology,American Pancreatic Association,American College of Gastroenterology,Yimaitong,Cochrane Library,PubMed,Em-bass,CINAHL,The Web of Science,CNKI,Wanfang databases.The retrieval time limit was from the data-base establishment to March 20,2022.The literatures types included thematic evidence summarization,guide-lines,evidence summaries,systematic reviews and expert consensus.The researchers conducted the literature quality evaluation.The literatures meeting the standard conducted the evidence extraction.Results A total of 13 arti-cles were included,including 3 special subject evidence summary,4 guidelines,2 evidence summary,2 systematic evalu-ation and 2 expert consensus.A total of 16 pieces of best evidence were integrated,involving 4 aspects of organization management,evaluation and monitoring,fluid infusion strategy and health education.Conclusion It is recommended to use the target-oriented therapy for early fluid resuscitation management,and perform the fluid resuscitation immediate-ly after diagnosis,according to the patient's underlying disease,disease changes and monitoring indicators,implement precise early fluid resuscitation in order to reverse pancreatic microcirculation disorder,increase tissue perfusion and improve the patient's prognosis.

BACKGROUND:The assessment of asymmetric gait quality plays a pivotal role in guiding rehabilitation training;however,the link between gait quality and kinematic-kinetic gait parameters remains ambiguous. OBJECTIVE:To formulate a machine-learning model for evaluating gait quality based on gait parameters,identify factors sensitive to gait quality from asymmetric gait parameters,investigate the relationship between gait indicators and gait quality,and provide guidance for asymmetric gait training and rehabilitation. METHODS:An asymmetric gait database was established through the creation of asymmetric conditions.Kinematic and kinetic data were collected from 8 young and 8 elderly subjects(all male,right dominant population)during gait tests.Gait quality for each test data set was assessed using symmetry indices,resulting in the creation of a gait parameter-gait quality dataset.Utilizing the Random Forest algorithm,a gait quality evaluation model was developed and key quality parameter factors were identified through differential analysis.This model was iteratively refined.The model's performance was evaluated through 10-fold cross-validation,and its effectiveness was verified using the cross-validation dataset. RESULTS AND CONCLUSION:(1)A gradient test was designed to categorize gait quality into optimal,suboptimal,intermediate,and poor groups,with 759,329,133,and 125 instances,respectively.(2)The application of the Random Forest algorithm in gait quality assessment was explored.A relationship model was established between gait indicators and gait quality,yielding a predictive model accuracy of 95.99%.(3)The 13 main parameters significantly influencing asymmetric gait quality were identified through the Random Forest model's feature importance ranking.(4)An analysis of gait quality sensitivity factors using the 13 important parameters led to the identification of five key sensitivity indexes.The Random Forest model utilizing these sensitivity factors achieved a predictive accuracy of 94.20%.

Objective:To explore the effects of ultra-high dose rate pulsed electron beams on Caenorhabditis elegans ( C. elegans). Methods:The adult wild-type strain (N2) of C. elegans was synchronized and cultured to L4 stage, and then randomly divided into control group (SHAM group), conventional radiotherapy dose rate group (CONV group) and ultra-high dose rate radiation group (UHDR group). The CONV and UHDR groups were exposed to 3 Gy of the pulsed electron beam at dose rates of 0.3 and 200 Gy/s, respectively. After irradiation, the egg-laying capacity of each group was assessed, and the developmental progress, motility, and survival rates each were evaluated at day 3, 6, and 10. Results:On the 3 rd day post-irradiation, both the CONV and UHDR groups showed shorter body lengths compared to the SHAM group ( t=4.81, 4.83, P<0.05), with no significant differences in body width ( P>0.05). On the 6 th and 10 th days, the CONV group showed a significant reduction in both body length and width compared to the SHAM group ( t=3.18-3.63, P<0.05), whereas the UHDR group displayed a significant increase in body length ( t=-9.85, -2.87, P<0.05) with no significant change in body width. When comparing the UHDR group to the CONV group on day 6 and 10, a significant increase in body width was observed ( t=-4.43, -3.37, P<0.05). Motor activity, including head swinging and body bending, significantly decreased in the CONV and UHDR groups compared to the SHAM group on day 6 ( t=2.91, 3.52, 3.97, 2.71, P<0.05), with no significant differences among the three groups by day 10 ( P>0.05). Egg-laying capacity significantly reduced in both irradiated groups compared to the SHAM group ( t=1.72, 5.54, P<0.05), while the UHDR group exhibited higher fecundity than the CONV group ( t=-5.99, P<0.05). Lifespan was significantly shortened in the CONV group compared to the SHAM group ( χ2=8.49, P<0.05), whereas the survival time of the UHDR group was not significantly differ from that of the SHAM group ( P>0.05). Conclusions:Exposure to a conventional electron beam result in developmental delays, reduced mobility, decreased fecundity, and a shortened lifespan in C. elegans. However, only slight side effects were observed when C. elegans were exposed to an ultra-high dose rate pulsed electron beam at the same dosage.

ObjectiveTo explore the mechanism of Buyang Huanwutang combined with bone marrow mesenchymal stem cell （BMSC） transplantation in the treatment of spinal cord injury （SCI）. MethodDifferent concentrations （12.5， 25， 50 g·kg^-1） of Buyang Huanwutang were administrated to rats by gavage. The spinal cord function of rats was measured by modified Tarlov score， and the most suitable concentration of Buyang Huanwutang was screened out. SD rats were then divided into 6 groups， namely， the sham operation group （gavage of equal amount of normal saline）， the model group （gavage of equal amount of normal saline）， the Buyang Huanwutang group （gavage of 25 g·kg^-1 Buyang Huanwutang）， the BMSC transplantation group （tail vein injection of BMSCs 1 mL）， the Buyang Huanwutang+BMSC group （gavage of 25 g·kg^-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL）， the Buyang Huanwutang+BMSC+LY294002 group （gavage of 25 g·kg^-1 Buyang Huanwutang and tail vein injection of BMSCs 1 mL and 40 mg·kg^-1 LY294002）， with 10 rats in each group. The spinal cord function was measured by the modified Tarlov score， inclined plate test， and latency of cortical somatosensory evoked potential. Immunohistochemistry was used to detect the number of 5-bromo-2-deoxyuracil nucleoside （Brdu）-labeled positive cells in the spinal cord tissue. The protein expression levels of phosphorylated protein kinase B （p-Akt）， glycoprotein 130 （gp130）， and interleukin-6 （IL-6） in spinal cord were detected by Western blot. ResultAs compared with the sham operation group， the Tarlov score and the critical angle of tilt plane in the model group were significantly decreased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 were significantly increased （P<0.05）. As compared with the model group， the Tarlov score and the critical angle of tilt plane in the sham operation group and each treatment group were significantly increased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 were significantly decreased （P<0.05）. As compared with the BMSC group， the Tarlov score and the critical angle of inclined plane in the Buyang Huanwutang+BMSC group increased （P<0.05）， the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 decreased （P<0.05）， and the number of Brdu-labeled positive cells increased 5 weeks after transplantation （P<0.05）. As compared with the Buyang Huanwutang+BMSC group， the Tarlov score and the critical angle of the inclined plane in the Buyang Huanwutang+BMSC+LY294002 group increased （P<0.05）， and the latency of cortical somatosensory evoked potential wave and the protein expression levels of p-Akt， gp130， and IL-6 decreased significantly （P<0.05）. Five weeks after transplantation， the number of Brdu-labeled positive cells increased significantly in the Buyang Huanwutang+BMSC+LY294002 group （P<0.05）. ConclusionBuyang Huanwutang can promote BMSCs migration and restore spinal cord function by inhibiting phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signal.

ObjectiveTo investigate the effect of calycosin-mediated glucoprotein130/Janus kinase/signal transducer and activator of transcription factor （GP130/JAK/STAT） signaling pathway on oxidative injury of astrocytes in spinal cord. MethodAstrocytes in rat spinal cord were isolated and identified by immunofluorescence detection of glial fibrillary acidic protein （GFAP）. The cells were respectively pre-treated with 5， 10， 20 μmol·L^-1 calycosin for 12 h， and then 100 μmol·L^-1 H₂O₂ （24 h） was added to induce oxidative injury. Cell counting kit-8 （CCK-8） assay was employed to detect cell proliferation and select the optimal concentration of calycosin. The following experimental groups were designed： control group， model group （100 μmol·L^-1 H₂O₂）， calycosin group （20 μmol·L^-1 calycosin）， calycosin + LY294002 group （20 μmol·L^-1 calycosin + 10 μmol·L^-1 LY294002）， and calycosin + Stattic group （20 μmol·L^-1 calycosin + 3 μmol·L^-1 Stattic）. CCK-8 assay and immunofluorescence method were used to detect the proliferation of cells and flow cytometry was applied to detect cell apoptosis and cycle. The protein expression of phosphorylated （p）-JAK2， p-STAT3， p-protein kinase B （Akt）， GP130， and interleukin-6 （IL-6） was detected by Western blotting. ResultCompared with the control group， the model group showed low proliferation activity and high apoptosis rate of cells （P<0.05）. Compared with the model group， calycosin （20 μmol·L^-1） group displayed high proliferation activity and low apoptosis rate of cells （P<0.05）. Compared with calycosin （20 μmol·L^-1） group， both phosphatidylinosirtol-3-kinases （PI3K） inhibitor LY294002 and STAT3 inhibitor Stattic significantly reduced the proliferation activity and increased the apoptosis rate of cells （P<0.05）. The protein expression of p-JAK2， p-STAT3， p-Akt， GP130， and IL-6 in the model group was higher than that in the control group （P<0.05）， and the expression of the above indicators was lower in each treatment group than in the model group （P<0.05）. ConclusionCalycosin can promote the proliferation and inhibit the apoptosis of astrocytes with oxidative injury by inhibiting the phosphorylation of PI3K/Akt pathway and JAK2/STAT3 pathway.

OBJECTIVE: To compare the diagnostic efficacy among three RT-PCR test kits for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection. METHODS: The throat swab samples from 40 hospitalized patients clinically diagnosed as coronavirus disease 2019 (COVID-19) and 16 hospitalized non-COVID-19 patients were recruited. The SARS-CoV-2 nucleic acid was detected in throat swab samples with RT-PCR test kits from Sansure Biotech ("Sansure" for short), Jiangsu Bioperfectus Technologies ("Bioperfectus" for short) and BGI Genomics ("BGI" for short). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Kappa value were analyzed. The viral nucleic acid was extracted from the throat swab samples by one-step cleavage and magnetic bead methods, and the efficacy of two extraction methods was also compared. The results of magnetic bead method for nucleic acid extraction by two different extractors (Sansure Natch CS S12C Fully Automated Nucleic Acid Extraction System vs. Tianlong NP968-C Nucleic Acid Extractor) were also compared. RESULTS: The sensitivity, specificity, PPV, NPV and kappa value were 95.00%, 87.50%, 95.00%, 87.50%and 0.825 for Sansure kit; 90.00%, 87.50%, 94.74%, 77.78%and 0.747 for the Bioperfectus kit, and 82.50%, 81.25%, 91.67%, 65.00%and 0.593 for the BGI kit, respectively. The positive, negative and total coincident rates and kappa value of viral nucleic acid detection results using the samples extracted by one-step cleavage and magnetic bead methods were 95.24%, 100.00%, 96.43%and 0.909, respectively, but the one-step cleavage method took only 25 min, while the magnetic bead method required 180 min. The positive, negative and total coincident rates and kappa value of viral nucleic acid detection results using the samples extracted by the two different nucleic acid extractors were 85.00%, 100.00%, 89.29% and 0.764, respectively. CONCLUSIONS The detection efficacy for SARS-CoV-2 nucleic acid by the Sansure kit is relatively higher and the one-step cleavage method has advantages of convenient operation and less time consuming.
Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnosis ; virology ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; RNA, Viral ; genetics ; isolation & purification ; Reagent Kits, Diagnostic ; standards