BACKGROUND:With the deepening of research on stem cell technology,how to make its accurate homing has become a major problem in clinical application.In addition to the induction of drugs and chemokines,electric fields are also widely used to guide the directional migration of stem cells.They can enhance their migration speed and orientation.OBJECTIVE:To summarize the effect of an electric field on the characteristics of stem cell migration and analyze the possible mechanism of action.METHODS:PubMed and CNKI databases were searched to collect relevant literature up to March 2024,with Chinese and English search terms"stem cells,direct current electric field,pulsed electric field,migration,electric field device,mechanism."Literature that was not available in full text and unrelated to the topic was excluded.RESULTS AND CONCLUSION:A total of 58 articles were included according to the screening requirements,including 15 Chinese articles and 43 English articles.In the literature,the effects of different parameters of the electric field on the migration of adipose-derived mesenchymal stem cells,bone marrow mesenchymal stem cells,neural stem cells,epidermal stem cells,human embryonic stem cells,and human induced pluripotent stem cells and its mechanism were studied in a migration device.(1)As a simple,non-invasive,and stable intervention method,the electric field plays an active role in guiding the directional migration of stem cells.(2)Different types of stem cells had different directions of electrotaxis migration,and the migration speed and directionality of most stem cells increased with the increase of electric field intensity.(3)Different electric field devices have different focuses in observing stem cell migration,and the relevant devices can be selected according to the purpose of the experiment.(4)The mechanism of electrotaxis migration of different stem cells is not completely the same.MAPK pathway,ROCK activation,and PI3K function are involved in the migration process of most stem cells,and other protein complexes and signaling pathways are involved in the regulation of this process.(5)In addition to different electric field parameters,cell senescence and culture environment also affect the results of electrotaxis migration.In summary,as an important signal that affects the migration characteristics of stem cells,the application of electric field combined with other emerging materials has shown certain potential in tissue engineering.It is expected to play a more important role in guiding stem cells to home,promoting bone tissue regeneration and repair,and making greater breakthroughs in the research of the nervous system,autoimmune system,tumors,and other diseases.

Objective To explore the differences in terahertz(THz)signal characteristics between normal and ischemic liver tissues of New Zealand rabbits using THz time-domain spectroscopy(THz-TDS),thereby providing a novel detection technique for the pathological detection of liver tissues.Methods Liver ischemia models were established in New Zealand rabbits.The THz scanning signal maps of normal and ischemic liver tissues were obtained using a reflective THz-TDS system,and the acquired signals were subjected to principal component analysis.Results Both normal and ischemic liver tissues displayed two distinct peaks in their THz signals.However,the amplitude of the THz signal in ischemic liver tissue was higher than that in normal liver tissue,with significant differences also observed in their signal morphologies.Principal component analysis results revealed a clear clustered distribution between the signals of normal and ischemic liver tissues,indicating that THz-TDS could effectively distinguish between the two tissue types.Conclusion THz-TDS can be applied to the detection of ischemic liver tissue,providing experimental evidence to support further research on the early diagnosis of liver ischemia and exhibiting broad prospects for clinical application.

Objective To explore the differences in terahertz(THz)signal characteristics between normal and ischemic liver tissues of New Zealand rabbits using THz time-domain spectroscopy(THz-TDS),thereby providing a novel detection technique for the pathological detection of liver tissues.Methods Liver ischemia models were established in New Zealand rabbits.The THz scanning signal maps of normal and ischemic liver tissues were obtained using a reflective THz-TDS system,and the acquired signals were subjected to principal component analysis.Results Both normal and ischemic liver tissues displayed two distinct peaks in their THz signals.However,the amplitude of the THz signal in ischemic liver tissue was higher than that in normal liver tissue,with significant differences also observed in their signal morphologies.Principal component analysis results revealed a clear clustered distribution between the signals of normal and ischemic liver tissues,indicating that THz-TDS could effectively distinguish between the two tissue types.Conclusion THz-TDS can be applied to the detection of ischemic liver tissue,providing experimental evidence to support further research on the early diagnosis of liver ischemia and exhibiting broad prospects for clinical application.

BACKGROUND:With the deepening of research on stem cell technology,how to make its accurate homing has become a major problem in clinical application.In addition to the induction of drugs and chemokines,electric fields are also widely used to guide the directional migration of stem cells.They can enhance their migration speed and orientation.OBJECTIVE:To summarize the effect of an electric field on the characteristics of stem cell migration and analyze the possible mechanism of action.METHODS:PubMed and CNKI databases were searched to collect relevant literature up to March 2024,with Chinese and English search terms"stem cells,direct current electric field,pulsed electric field,migration,electric field device,mechanism."Literature that was not available in full text and unrelated to the topic was excluded.RESULTS AND CONCLUSION:A total of 58 articles were included according to the screening requirements,including 15 Chinese articles and 43 English articles.In the literature,the effects of different parameters of the electric field on the migration of adipose-derived mesenchymal stem cells,bone marrow mesenchymal stem cells,neural stem cells,epidermal stem cells,human embryonic stem cells,and human induced pluripotent stem cells and its mechanism were studied in a migration device.(1)As a simple,non-invasive,and stable intervention method,the electric field plays an active role in guiding the directional migration of stem cells.(2)Different types of stem cells had different directions of electrotaxis migration,and the migration speed and directionality of most stem cells increased with the increase of electric field intensity.(3)Different electric field devices have different focuses in observing stem cell migration,and the relevant devices can be selected according to the purpose of the experiment.(4)The mechanism of electrotaxis migration of different stem cells is not completely the same.MAPK pathway,ROCK activation,and PI3K function are involved in the migration process of most stem cells,and other protein complexes and signaling pathways are involved in the regulation of this process.(5)In addition to different electric field parameters,cell senescence and culture environment also affect the results of electrotaxis migration.In summary,as an important signal that affects the migration characteristics of stem cells,the application of electric field combined with other emerging materials has shown certain potential in tissue engineering.It is expected to play a more important role in guiding stem cells to home,promoting bone tissue regeneration and repair,and making greater breakthroughs in the research of the nervous system,autoimmune system,tumors,and other diseases.

Cryoablation therapy with explicit anti-tumor mechanisms and histopathological manifestations has a long history.A large number of clinical practice has shown that cryoablation therapy is safe and effective,making it an ideal tumor treatment method in theory.Previously,its efficacy and clinical application were constrained by the limitations of refrigerants and refrigeration equipment.With the development of the new generation of cryoablation equipment represented by argon helium knives,significant progress has been made in refrigeration efficien-cy,ablation range,and precise temperature measurement,greatly promoting the progression of tumor cryoablation technology.This consensus systematically summarizes the mechanism of cryoablation technology,indications for oral mucosal melanoma(OMM)cryotherapy,clinical treatment process,adverse reactions and management,cryotherapy combination therapy,etc.,aiming to provide reference for carrying out the standardized cryoablation therapy of OMM.

Objective:To investigate the influences and mechanism of extracellular vesicles from dermal papilla cells (DPC-EVs) of mice on human hypertrophic scar fibroblasts (HSFs).Methods:The study was an experimental research. The primary dermal papilla cells (DPCs) of whiskers were extracted from 10 6-week-old male C57BL/6J mice and identified successfully. The DPC-EVs were extracted from the 3 rd to 5 th passage DPCs by ultracentrifugation, and the morphology was observed through transmission electron microscope and the particle diameter was detected by nanoparticle tracking analyzer ( n=3) at 24 h after culture. The 3 rd passage of HSFs were divided into DPC-EV group and phosphate buffer solution (PBS) group, which were cultured with DPC-EVs and PBS, respectively. The cell scratch test was performed and cell migration rate at 24 h after scratching was calculated ( n=5). The cell proliferation levels at 0 (after 12 h of starvation treatment and before adding DPC-EVs or PBS), 24, 48, 72, and 96 h after culture were detected by using cell counting kit 8 ( n=4). The protein expressions of α-smooth muscle actin (α-SMA) and collagen typeⅠ (ColⅠ) in cells at 24 h after culture were detected by immunofluorescence method and Western blotting, and the protein expression of Krüppel-like factor 4 (KLF4) in cells at 24 h after culture was detected by Western blotting. After the 3 rd passage of HSFs were cultured with DPC-EVs for 24 h, the cells were divided into blank control group, KLF4 knockdown group, and KLF4 overexpression group according to the random number table. The cells in blank control group were only routinely cultured for 48 h. The cells in KLF4 knockdown group and KLF4 overexpression group were incubated with KLF4 knockdown virus for 24 h, then the cells in KLF4 knockdown group were routinely cultured for 24 h while the cells in KLF4 overexpression group were incubated with KLF4 overexpression virus for 24 h. The protein expressions of KLF4, α-SMA, and ColⅠ in cells were detected by Western blotting at 48 h after culture. Results:At 24 h after culture, the extracted DPC-EVs showed vesicular structure with an average particle diameter of 108.8 nm. At 24 h after scratching, the migration rate of HSFs in PBS group was (54±10)%, which was significantly higher than (29±8)% in DPC-EV group ( t=4.37, P<0.05). At 48, 72, and 96 h after culture, the proliferation levels of HSFs in DPC-EV group were significantly lower than those in PBS group (with t values of 4.06, 5.76, and 6.41, respectively, P<0.05). At 24 h after culture, the protein expressions of α-SMA and ColⅠ of HSFs in DPC-EV group were significantly lower than those in PBS group, while the protein expression of KLF4 was significantly higher than that in PBS group. At 48 h after culture, compared with those in blank control group, the protein expression of KLF4 of HSFs in KLF4 knockdown group was down-regulated, while the protein expressions of α-SMA and ColⅠ were both up-regulated; compared with those in KLF4 knockdown group, the protein expression of KLF4 of HSFs in KLF4 overexpression group was up-regulated, while the protein expressions of ColⅠ and α-SMA were down-regulated. Conclusions:The DPC-EVs of mice can inhibit the proliferation and migration of human HSFs and significantly inhibit the expressions of fibrosis markers α-SMA and ColⅠ in human HSFs by activating KLF4.

Objective:To analyze the current situation and influencing factors of work-related musculoskeletal disorders (WMSDs) among scientific researchers in a computer workstation of a high-tech aerospace enterprise, and to provide data support for the improvement of occupational health management policies in this type of enterprise.Methods:From March to April 2023, using convenient sampling method, 1398 scientific researchers using computer workstations in an aerospace high-tech enterprise in Beijing were selected as the research subjects. The incidence of WMSDs in various parts of the body was investigated by using the Musculoskeletal Disorders Questionnaire, and the influencing factors of WMSDs in neck, lower back, shoulder and upper back were analyzed by logistic regression.Results:The total incidence of WMSDs was 55.4% (774/1398) in the scientific researchers who used computer workstations. The top 4 body parts in WMSDs incidence were neck (24.3%, 340/1398), lower back (20.4%, 285/1398), shoulder (18.7%, 262/1398), upper back (12.7%, 177/1398). The results of multivariate logistic regression analysis showed that feeling slightly tired and tired after work, setting a rest/break time of 10 to 15 min before the next continuous job, and operating computer for 2 to 4 hours and >4 hours were the influencing factors for the occurrence of neck WMSDs ( OR=3.08, 1.90, 0.60, 2.00, 1.49, P<0.05). Female, 5-<10 years of working experience, feeling slightly tired, tired and very tired after work, operating computer for 6-<8 hours and 8-10 hours a day were all the influencing factors for the occurrence of WMSDs in the lower back ( OR=1.82, 0.64, 2.95, 1.80, 1.61, 1.82, 1.73, P<0.05). Female, feeling slightly tired and tired after work were the influencing factors of shoulder WMSDs occurrence ( OR=2.42, 2.09, 2.00, P<0.05). Female, 5-<10 years, 10-15 years of working age, 1-3 times of physical exercise/quarter, feeling slightly tired, tired and very tired after work were the influencing factors for the occurrence of upper back WMSDs ( OR=2.76, 2.19, 2.78, 0.48, 4.20, 2.66, 2.19, P<0.05) . Conclusion:The incidence of WMSDs among scientific researchers in computer workstations of aerospace high-tech enterprises is high, which is closely related to individual characteristics and workstation usage characteristics. Measures should be taken to prevent and improve the WMSDs status of scientific researchers.

Objective:To analyze the current situation and influencing factors of work-related musculoskeletal disorders (WMSDs) among scientific researchers in a computer workstation of a high-tech aerospace enterprise, and to provide data support for the improvement of occupational health management policies in this type of enterprise.Methods:From March to April 2023, using convenient sampling method, 1398 scientific researchers using computer workstations in an aerospace high-tech enterprise in Beijing were selected as the research subjects. The incidence of WMSDs in various parts of the body was investigated by using the Musculoskeletal Disorders Questionnaire, and the influencing factors of WMSDs in neck, lower back, shoulder and upper back were analyzed by logistic regression.Results:The total incidence of WMSDs was 55.4% (774/1398) in the scientific researchers who used computer workstations. The top 4 body parts in WMSDs incidence were neck (24.3%, 340/1398), lower back (20.4%, 285/1398), shoulder (18.7%, 262/1398), upper back (12.7%, 177/1398). The results of multivariate logistic regression analysis showed that feeling slightly tired and tired after work, setting a rest/break time of 10 to 15 min before the next continuous job, and operating computer for 2 to 4 hours and >4 hours were the influencing factors for the occurrence of neck WMSDs ( OR=3.08, 1.90, 0.60, 2.00, 1.49, P<0.05). Female, 5-<10 years of working experience, feeling slightly tired, tired and very tired after work, operating computer for 6-<8 hours and 8-10 hours a day were all the influencing factors for the occurrence of WMSDs in the lower back ( OR=1.82, 0.64, 2.95, 1.80, 1.61, 1.82, 1.73, P<0.05). Female, feeling slightly tired and tired after work were the influencing factors of shoulder WMSDs occurrence ( OR=2.42, 2.09, 2.00, P<0.05). Female, 5-<10 years, 10-15 years of working age, 1-3 times of physical exercise/quarter, feeling slightly tired, tired and very tired after work were the influencing factors for the occurrence of upper back WMSDs ( OR=2.76, 2.19, 2.78, 0.48, 4.20, 2.66, 2.19, P<0.05) . Conclusion:The incidence of WMSDs among scientific researchers in computer workstations of aerospace high-tech enterprises is high, which is closely related to individual characteristics and workstation usage characteristics. Measures should be taken to prevent and improve the WMSDs status of scientific researchers.

Objective:To analyze the occurrence of early hypotony after the intravitreal injection of anti-vascular endothelial growth factor (VEGF) and its risk factors.Methods:A case-control study was performed.One hundred and twenty-seven eyes of 127 patients with fundus vascular disease who received intravitreal injections of anti-VEGF drugs were enrolled in Henan Provincial People's Hospital from January 2020 to January 2022.Of the 127 patients, there were 71 males and 56 females, with an average age of (61.85±11.53) years and a mean intraocular pressure of (15.28±3.71)mmHg (1 mmHg=0.133 kPa). All subjects were intravitreally injected with 0.05 ml of anti-VEGF drugs, including 56 cases receiving ranibizumab, 38 cases receiving conbercept and 33 cases receiving aflibercept.The intraocular pressure was measured with a non-contact tonometer at 30 minutes, 1 hour and 2 hours after the injection.The cases were grouped as hypotony group or non-hypotony group according to the intraocular pressure of subjects was less than 10 mmHg or not.The differences in sex, age, distribution of left eye and right eye, disease type, intraocular pressure before injection, injection frequency, lens status, drug type, injection timing, injection site, with or without high myopia, with or without a history of glaucoma or ocular hypertension, and with or without a history of vitreoretinal surgery were analyzed to investigate the factors with a P-value <0.05, which were used as the independent variable and the occurrence of hypotony as the dependent variable in logistic regression analysis to explore the risk factors for hypotony.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Henan Eye Hospital (No.HNEEC-2022-42). Results:Hopotony occurred in 8 eyes within 2 hours after the injection.There were significant differences in intraocular pressure at different time points before and after injection between the hypotony and non-hypotony groups ( Fgroup=62.177, P<0.001; Ftime=25.128, P<0.001). The intraocular pressure of the hypotony group at 30 minutes, 1 hour and 2 hours after injection were lower than before injection, and the intraocular pressure of the non-hypotony group was higher at 30 minutes after injection than before injection (all at P<0.05). The average reduction of intraocular pressure of the hypotony group was 7.88, 7.63 and 7.23 mmHg at 30 minutes, 1 hour and 2 hours after the injection, and the intraocular pressure returned to baseline level at 1 day after injection.There was no significant difference in sex, distribution of left and right eyes, disease type, pre-injection intraocular pressure, injection frequency, lens status, drug type, injection timing, injection site, with or without a history of high myopia and with or without a history of glaucoma or ocular hypertension between the two groups.There were significant differences in age and with or without a history of vitreoretinal surgery between the two groups ( t=8.265, P<0.001; χ2=6.907, P=0.035). Multivariate logistic regression analysis showed younger patients and having a history of vitreoretinal surgery were the risk factors for early hypotony after anti-VEGF intravitreal injection (odds ratio=88.563, P<0.001; odds ratio=20.991, P=0.009). Conclusions:Patients with younger age and having a history of vitreoretinal surgery are susceptible to early hypotony after anti-VEGF intravitreal injection.

Objective:To evaluate the value of dual-energy CT (DECT) mixed images CT in predicting hemorrhagic transformation (HT) after endovascular therapy (EVT) of acute ischemic stroke (AIS).Methods:From October 2018 to January 2020, the immediate dual-energy CT images of intracranial high attenuation (HA) regions in patients with AIS after endovascular treatment in Wuhan No.1 Hospital were retrospectively analyzed. According to the diagnostic criteria of CT or diffusion weighted image in 72 hours of follow-up, they were classified into HT group and non-HT group. The CT value of mixed images, contrast media, and virtual non-enhancement (VNC) and iodine concentration in the highest attenuation areas were measured. Intragroup correlation coefficient was used to evaluate the consistency among the readers; Mann-Whitney U test was used to compare the difference between the two groups of quantitative parameters; Spearman correlation analysis was uesd for evaluating correlation between mixed images CT value and contrast media CT value, VNC CT value, and iodine concentration. The receiver operating characteristic curve was used to analyze the quantitative parameters to predict the diagnostic efficacy of HT. Results:A total of 154 cases were enrolled, with 65 cases in the HT group and 89 cases in the non-HT group. The intraclass correlation coefficient of CT values of mixed images was 0.861 ( P<0.05). Comparing the non-HT group and the HT group,the CT value of mixed images [59.40(54.84, 63.05) HU vs 100.10(79.90, 122.40) HU, Z=-10.87, P<0.001],contrast agent CT value [24.90(20.75, 30.05) HU vs 66.60(47.10, 84.15) HU, Z=-10.85, P<0.001] and iodine concentration [1.10(1.00, 1.30) mg/ml vs 2.90(2.05, 3.65) mg/ml, Z=-10.85, P<0.001] both increased in the HT group, but there was no significant difference in VNC CT values between the two groups [33.60(31.80, 35.70) HU vs 34.30(30.90, 38.00) HU, Z=-0.50, P=0.62]. There was a highly significant correlation between the CT value of mixed images and iodine concentration ( r=0.99, P<0.01). Using CT value>72.60 HU as the diagnostic cutoff value for predicting HT, the sensitivity and specificity were 89.23% and 95.51%, respectively. Conclusions:The CT value of DECT mixed images after EVT can be used to predict HT within 72 hours. When DECT was not available, conventional CT scan′s intracranial HA density over 72.60 HU can be selected as the cutoff value for predicting HT.