1.Development of a mobile personnel radiation protection equipment
Yuan HE ; Hongchao PANG ; Yang LIU ; Jianhua WU ; Junlin WANG ; Yanan HONG ; Xubiao CHEN ; Hualin WANG ; Xiaoyu SHI ; Miao PAN ; Qiang WANG
Chinese Journal of Radiological Health 2024;33(2):158-163
Objective To design a mobile personnel radiation protection equipment for operation in environments with high radiation such as spent fuel reprocessing plants, to achieve simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol, to reduce the internal and external exposure dose of radioactive workers, and to meet the requirement of operation for two hours. Methods The core parts of the mobile personnel radiation protection equipment included a shielding chamber and a respiratory maintenance system. An automated chassis was used for the movement and lifting of the shielding chamber. MCNP software was used to simulate and calculate the protective effects of shielding chamber made of different materials and material thicknesses. Experimental verification of the shielding chamber design was conducted. Mathematical models were established to describe the variations in the content of various gases in the chamber with personnel operation time. A respiratory maintenance system, a harmful gas absorption device, and an automated mobile chassis were designed. Results The shielding chamber made of polyethylene with a thickness of 80 mm achieved an 80% neutron shielding rate. The respiratory maintenance system could support workers for 2 hours of operation inside the equipment. The mobile chassis allowed operation of the equipment with one person. Conclusion This mobile personnel radiation protection equipment can solve the problem in simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol. The equipment can provide radiation protection for radioactive workers, reduce exposure dose, and reduce personnel burden. This system provides technical means for the operation and maintenance of equipment in high-radiation sites such as spent fuel reprocessing plants.
2.Feasibility study of low tube voltage and low contrast medium combined with IMR technology in 3DCTA of vertebral artery V3 segment
Junlin YANG ; Duchang ZHAI ; Xiuzhi ZHOU ; Rong LIU ; Guohua FAN ; Wu CAI
Chongqing Medicine 2024;53(1):5-10
Objective To investigate the feasibility of low-voltage,automatic tube current adjustment(ATCM)and low contrast agent concentration,dose and injection rate combined with full-model iterative re-construction(IMR)in vertebral artery V3-segment three-dimensional CT angiography(3DCTA).Methods A total of 60 patients with suspected upper cervical spine,craniocervical junction lesions undergoing cervical vertebral artery V3 segment 3DCTA in this hospital from November 2019 to May 2020 were selected and divided into the group A and B by adopting the random number table method,30 cases in each group.The group A adopted the ATCM technology of 80 kV,average tube current of 50 mAs,25 mL of contrast agent io-hexol(iodine content 300 mg/mL)combined IMR technology with an injection rate of 3 mL/s,while the group B adopted 120 kV,150 mAs fixed tube current,50 mL injection rate of 5 mL/s contrast agent iopamidol(iodine content 370 mg/mL)combined filter back projection(FBP)reconstruction technology.CT value,noise,signal-to-noise ratio(SNR),contrast noise ratio(CNR)and image sensitivity(FOM)were measured and compared between the two groups and the quality of the resulting images was evaluated.The CT volumet-ric dose index(CTDIvol)and dose-length product(DLP)were recorded,and the effective dose(ED)was cal-culated.Results There was no statistically significant difference in the vertebral arterial CT value between the two groups(P>0.05),but the noise of the group A was lower than that of the group B(P<0.05),SNR,CNR and FOM of the group A were greater than those of the group B(P<0.05).The image quality of the two groups met the requirements of clinical diagnosis[(4.78±0.41)points vs.(4.85±0.35)points],and there was no statistically significant difference in the subjective evaluation of image quality(P>0.05).The CTDIvol,DLP and ED levels in the group A were lower than those in the group B(P<0.05).The iodine in-takes of contrast medium in the group A and group B were 7.5 g and 18.5 g,respectively,and the iodine flow rates of contrast agent were 0.9 and 1.85 mg/s,respectively,and compared with group B,the iodine intake and iodine flow rate of the group A were decreased by 59.5%and 51.4%,respectively.Conclusion Low tube voltage ATCM and low contrast concentration,dose and injection rate combined with IMR technology can not only ensure the 3DCTA image quality of vertebral artery V3 segment,but also reduce the radiation dose re-ceived by the patients,and reduce the iodine intake and iodine flow rate of contrast agent.
3.Influence of storage temperature and storage time on the optically stimulated luminescence characteristics of chip resistors in dose reconstruction for nuclear accident
Junlin WANG ; Jianhua WU ; Yang LIU ; Ling CHEN
Chinese Journal of Radiological Health 2024;33(3):273-277
Objective To assess the feasibility of employing chip resistors for retrospective dose reconstruction following nuclear accidents, to examine the effects of storage temperature and storage time on the optically stimulated luminescence (OSL) characteristics of the chip resistors, and to explore measures to mitigate these effects. Methods Chip resistors were analyzed using automated instruments for measuring thermoluminescence and OSL manufactured by Risø in Denmark with various parameters to understand the impact of storage temperature and storage time on OSL signals. Results The OSL signals of chip resistors exhibited exponential attenuation within 10 min after irradiation, and then stabilized (count change < 10%) within 2-7 days of storage. The chip resistors exhibited linear dose responses within 1-3 days of storage after 0.1-2 Gy irradiation. OSL signals diminished as the storage temperature increased. However, preheating at 130 ℃ for 1 min effectively eliminated the differences caused by temperatures between 25 ℃ and 45 ℃. Conclusion The OSL signals of chip resistors are influenced by storage temperature and storage time. When preheated at 130 ℃ for 1 min, chip resistors stored for 1-7 days and at 25-45 ℃ exhibited OSL signal errors of 10% or less. This result emphasizes the importance of preheating for measurements in practical applications, thus providing a scientific approach and a solid foundation for the use of chip resistors in retrospective dose reconstruction.
4.Subacute exposure to DEHP leads to impaired decidual reaction and exacerbates the risk of early miscarriage in mice
Qiuju LIU ; Liping TAN ; Liu YUAN ; Xuemei CHEN ; Fangfang LI ; Junlin HE ; Rufei GAO
Journal of Zhejiang University. Medical sciences 2024;53(3):331-341
Objective:To investigate the effect of subacute exposure of Di(2-ethylhexyl)phthalate(DEHP)on endometrial decidualization and early pregnancy miscarriage in mice.Methods:CD1 mice were orally administrated with 300(low-dose group),1000(medium-dose group),or 3000 mg·kg-1·d-1 DEHP(1/10 LD50,high-dose group)for 28 days,respectively.An early natural pregnancy model and an artificially induced decidualization model were established.The uterine tissues were collected on D7 of natural pregnancy and D8 of artificially induced decidualization,respectively.The effects of a subacute exposure to DEHP on the decidualization of mice were detected by HE staining,Masson staining,TUNEL assay,and Western blotting.A model of spontaneous abortion was constructed in mice after subacute exposure to 300 mg·kg-1·d-1 DEHP,and the effect of impaired decidualization on pregnancy was investigated by observing the pregnancy outcome on the 10th day of gestation.Results:Compared with the control group,the conception rate was significantly decreased in the high-dose DEHP subacute exposure group(P<0.05).HE staining showed that,compared with the control group,the decidual stromal cells in the low-and medium-dose exposure groups were disorganized,the nuclei of the cells were irregular,the cytoplasmic staining was uneven,and the number of polymorphonuclear cells was significantly reduced.Masson staining showed that compared with the control group,the collagen fibers in the decidua region of the DEHP low-dose group and the medium-dose group were more distributed,more abundant and more disorderly.TUNEL assay showed increased apoptosis in the decidua area compared to the control group.Western blotting showed that the expression of BMP2,a marker molecule for endometrial decidualization,was significantly reduced(P<0.05 or P<0.01).The abortion rate and embryo resorption rate were increased,and the number of embryos,uterine wet weight,uterine area and placenta wet weight were decreased in DEHP low-dose group compared to the control group stimulated by mifepristone,an abortifacient drug(P<0.05 or P<0.01).Conclusion:Subacute exposure to DEHP leads to impaired endometrial decidualization during early pregnancy and exacerbates the risk of adverse pregnancy outcomes in mice.
5.Effects of glenosphere offsets on impingement-free range of motion in reverse total shoulder arthroplasty: a standardized computer simulation study
Xiaopei XU ; Qingnan SUN ; Maoqi GONG ; Xieyuan JIANG ; Yang LIU ; Dong WANG ; Hanzhou WANG ; Shuo DIAO ; Junlin ZHOU
Chinese Journal of Orthopaedic Trauma 2024;26(2):156-162
Objective:To compare the effects of glenosphere offset positions on the impingement-free range of motion (ROM) in reverse total shoulder arthroplasty (RTSA).Methods:Shoulder joint models were reconstructed using shoulder CT scans of 6 patients with primary osteoarthritis. RTSA was performed virtually according to standard surgical procedures, and shoulder movements were simulated. Reverse shoulder models were constructed with 2 lateral offsets (0 and 4 mm) and 6 positional offsets (center, inferior, posterior, anterior, anterior-inferior, and posterior-inferior). The impingement-free ROM and impingement sites for abduction-adduction, flexion-extension, total rotation (sum of internal and external rotation), and total ROM (sum of ROM in all movement modes) were evaluated.Results:All the 12 combinations of different glenosphere offsets achieved 50% of the original shoulder ROM in all movements. In the abduction-adduction motion with 0 and 4 mm lateral offsets, the anterior-inferior offset provided the largest ROM (94.4°±8.7° and 105.3°±6.9°, respectively), but there was no significant difference between the positions ( P>0.05). In the flexion-extension motion with 0 and 4 mm lateral offsets, the posterior-inferior offset showed the largest ROM (194.1°±6.9° and 196.9°±9.7°, respectively), but there was no significant difference between the positions ( P>0.05). In the total rotation motion with 0 and 4 mm lateral offsets, the anterior-inferior offset had the largest ROM (141.5°±5.9° and 160.6°±8.5°, respectively), showing significant advantages over the center, anterior, and posterior offsets ( P<0.05), but insignificant advantages over the inferior and posterior-inferior offsets ( P>0.05). In total ROM, the anterior-inferior offset provided the largest ROM. When the lateral offset was 0 mm, the anterior-inferior offset provided a ROM of 421.8°±16.4°, showing significant advantages over the center and posterior offsets ( P<0.05). Compared with the lateral glenosphere offset of 0 mm, the lateral glenosphere offset of 4 mm significantly improved total shoulder ROM (122.8°±10.6° versus 145.8°±4.8°) and total ROM (390.9°±11.6° versus 428.4°±19.8°) ( P<0.05). Conclusions:The anterior-inferior, inferior, and posterior-inferior glenosphere offsets can improve ROM in all movement patterns. The position and lateral offset of the glenosphere significantly affect the total rotation and total ROM of the shoulder joint. Specifically, the anterior-inferior and inferior offsets show significant advantages over the center position in total rotation and total ROM of the shoulder joint.
6.Effect of radiofrequency ablation on improving cardiac structure and function in patients with atrial fibrillation and functional mitral regurgitation
Shunxiang LI ; Zhuoshan HUANG ; Suhua LI ; Junlin ZHONG ; Xujing XIE ; Ruimin DONG ; Jinlai LIU ; Jieming ZHU ; Zhenda ZHENG
Chinese Journal of Cardiology 2024;52(10):1170-1176
Objective:Exploring the effect of radiofrequency ablation treatment to restore sinus rhythm on the improvement of functional mitral regurgitation (FMR) and cardiac structure in patients with atrial fibrillation combined with moderate or severe FMR, compared with drug therapy alone.Methods:This retrospective cohort study consecutively enrolled patients diagnosed with persistent atrial fibrillation and moderate or severe FMR who were admitted to the Third Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2021. Forty-eight patients who were treated with radiofrequency ablation and maintained sinus rhythm were enrolled in the ablation group, and 63 patients who were treated with medication alone during the same period were in the medicine group. Patients in the ablation group and medicine group were matched in a 1∶1 ratio using a propensity score, and 41 patients were finally included in each of the 2 groups. All patients reexamined echocardiography after 3-month of treatment. The proportion of patients with FMR improvement and the differences in changes of cardiac structural and functional parameters were compared between groups.Results:After propensity score matching, the ablation group was aged (69.3±7.1) years with 21 males (51.2%) and the medicine group was aged (71.3±9.4) years with 21 males (51.2%). The echocardiography after 3-month of treatment showed the rate of FMR improvement was significantly higher in the ablation group than in the medicine group (19 (46.3%) vs. 33 (80.5%), P<0.001), and patients in the ablation group showed a significant decrease in FMR extent (Δmitral regurgitation area: (-1.30±2.64) cm 2 vs. (-3.55±2.50) cm 2, P<0.001), left atrial size (Δleft atrial diameter: (-0.17±3.78) mm vs. (-2.46±4.01) mm, P=0.009) and E/e′ (ΔE/e′:-2.54±7.34 vs.-6.34±7.08, P=0.021) compared with the medicine group. There was also a significant decrease in left ventricular size (Δleft ventricular end diastolic diameter: (-3.12±6.62) mm vs. (-0.73±3.62) mm, P=0.046) and significant increase in left ventricular ejection fraction (Δleft ventricular ejection fraction: (2.73±9.69) % vs. (-0.93±5.41) %, P=0.038) in ablation group. Conclusion:Performing radiofrequency ablation to restore sinus rhythm can effectively reduce the severity of mitral regurgitation and improve left atrial and left ventricular remodeling and cardiac function in patients with atrial fibrillation and FMR.
7.Clinical efficacy of full surgical area closure technique in percutaneous co-axial large-channel endo-scopic lumbar interbody fusion in the treatment of degenerative lumbar spondylolisthesis
Junlin LIU ; Qiang YU ; Pin FENG
Chinese Journal of Spine and Spinal Cord 2024;34(6):576-584
Objectives:To explore the application value of percutaneous co-axial large-channel endoscopic lumbar interbody fusion(PLE-LIF)combined with full surgical area closure technique(FSAC)in the treatment of degenerative lumbar spondylolisthesis.Methods:A retrospective analysis was conducted on 83 patients with single-segment degenerative lumbar spondylolisthesis who underwent PLE-LIF in our hospital from January 2020 to January 2023.Among the patients,46 received FSAC treatment during operation(FSAC group),and 37 patients did not receive FSAC treatment(N-FSAC group).Both groups of patients were comparable in gen-eral information such as gender,age,course of illness,and length of hospital stay(P>0.05).The two groups of patients were followed up for l year.The operative time and complications of the two groups of patients were recorded.Both groups of patients were followed up regularly for 1 year.The visual analogue scale(VAS)for low back pain and lower limb pain was recorded on ld before surgery,3d after surgery,at 3 months and 1 year after surgery,in addition,the Oswestry disability index(ODI)on 1d before surgery,at 3 months and 1 year after surgery was recorded.X-ray examination was performed at 3 months after operation,and Meyerding grading was used to evaluate the reduction of spondylolisthesis.CT examination was performed at 1 year after operation,and Brantigan criteria were used to evaluate the intervertebral fusion.Results:The operative time in the FSAC group was shorter than that in the N-FSAC group(118.9±10.6min vs 130.6±16.3min,P<0.05).The VAS for low back pain and lower limb pain and ODI at each postoperative time point in the two groups were significantly lower than those before surgery(P<0.05),and there was no statistically significant difference between the two groups at each time point(P>0.05).Two cases of lower limb numbness occurred in the N-FSAC group,while none occurred in the FSAC group;There were 4 cases and 1 case of neuroedema pain in the N-FSAC group and FSAC group,respectively;1 case in each group respectively had cage displacement,and there was no internal fixation loosening,infection,or dural sac tear in both groups.The incidence rate of intraoperative complications in the N-FSAC group was higher than that in the FSAC group(18.9%vs 4.3%)(P<0.05).One year after surgery,the degree of slippage in both groups of patients improved significantly compared to the conditions before operation(P<0.05),and there was no significant difference between the two groups(P>0.05);Intervertebral fusion occurred in 42 cases in the FSAC group,and 34 cases in the N-FSAC group,and no statistically significant difference was there in the fusion rate(91.3%vs 91.9%)and intervertebral fusion grading between the two groups(P<0.05).Conclusions:PEL-LIF combined with FSAC can shorten the operative time and improve safety in treating single-segment degenerative lumbar spondylolisthesis.
8.Advances in the study of epigenetic regulatory mechanisms of astrocytes
Liuqing XU ; Peiyuan ZHAO ; Xihong LIU ; Xiaodan DU ; Mengyang FAN ; Junlin HOU
Chinese Journal of Comparative Medicine 2024;34(5):126-133
Astrocytes(AS)are the most abundant glial cells in the central nervous system and are involved in many physiological and pathological processes in the nervous system.Alterations in their phenotype are particularly important for the health of the CNS.Epigenetic mechanisms,including DNA methylation,histone modification,non-coding RNA regulation,and chromatin remodeling,are closely linked to alterations in AS proliferation,differentiation,inflammation,and other phenotypic features,but how these mechanisms function needs to be explored and summarized.By reviewing the recent advances in the role of epigenetic mechanisms in AS under various physiological and pathological states,we aim to provide new ideas for the understanding and treatment of related diseases.
9.Characterization and antibacterial activity of prokaryotic recombinantly expressed phage lysin LysZHSHW of Acinetobacter baumannii
Yuqian LIN ; Junlin LIU ; Jiali DENG ; Jinglin HUANG ; Zheming SHI ; Fenglin FENG ; Yongxue SUN
Chinese Journal of Veterinary Science 2024;44(9):1965-1975
The aim of this study is to evaluate the in vitro and in vivo antibacterial potential of Ly-sZHSHW,a phage lysin against Acinetobacter baumannii infections,and to study its characteris-tics.The pET28a-Lys recombinant plasmid containing LysZHSHW coding gene was constructed by PCR,enzyme digestion and ligation using the expression plasmid pET28a as the backbone and ex-pressed in E.coli BL21(DE3).After confirming the expression of the LysZHSHW through West-ern blot analysis,its characterization and potential applications were assessed both in vitro and in vivo.The results showed that the pET28a-Lys recombinant plasmid was successfully constructed and the LysZHSHW protein was expressed correctly.The mass concentration of the purified en-zyme was 4 086 mg/L,which could be used for subsequent experiments.The enzymatic activity of LysZHSHW was determined to be 630 U/μg,with maximum activity observed at 25 ℃ and pH9.0.In vitro experiments demonstrated that 1 000 or 750 mg/L of LysZHSHW,in the presence of EDTA,resulted in a four-log reduction in bacterial counts without any cytotoxicity.In vivo,2.5 μg of LysZHSHW combined with EDTA could increase the survival rate of Galleria mellonel-la larvae infection model to 92.86%after 24 hours,and 0.15 mg of LysZHSHW reduced the bacte-rial load in the thighs of mice by 2.8 logs and alleviated the inflammatory response in muscle fi-bers.In conclusion,LysZHSHW derived from Acinetobacter baumannii bacteriophage exhibited characteristics such as stability at room temperature,alkaline pH,and safety,making it a promis-ing candidate as a novel antimicrobial agent.
10.Research progress of microRNA involved in perioperative neurocognitive disorders regulation
Junlin LIU ; Yi LI ; Wenjie LIU
The Journal of Clinical Anesthesiology 2024;40(10):1079-1084
Perioperative neurocognitive disorders(PND)is one of the common complications in the perioperative period,especially in elderly patients,and the incidence of PND is high and it is closely related to the prognosis of surgery.The currently accepted pathogenesis of PND includes central nervous sys-tem inflammation,synaptic dysfunction,apoptosis,oxidative stress,and neurofibrillary tangles,etc.Mi-croRNAs(miRNAs),as key gene expression regulators of neurological development and function,are not only directly involved in these processes,but also indirectly affect PND development through the modulation of the microbiota-gut-brain axis,perioperative mood regulation,and postoperative pain.In this paper,we review the role of miRNA in regulating perioperative neurocognitive disorders,with the aim of providing new ideas for the diagnosis and prevention of PND,as well as for the development of targeted therapies for this disease.

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