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Objective To investigate the effects of force on mechanical stability of FLNa-Ig21/αⅡbβ3-CT complex and the regulation mechanism.Methods The FLNa-Ig21/αⅡbβ3-CT crystal structures were taken from the PDB database.The stability of the complexes in a physiological environment as well as the unfolding path and mechanical stability induced by mechanical forces were analyzed using equilibrium and steered molecular dynamics simulations.Results During the equilibration,the survival rate of most salt bridge and hydrogen bonds was below 0.5,and the interactions between FLNa-Ig21 and αⅡbβ3-CT was relatively weak.During stretching at a constant velocity,the complex could withstand a tensile force of 70-380 pN,and its mechanical strength depended on the force-induced dissociation path.Under a constant force of 0-60 pN,the complexes exhibited a slipping-bond trend,and the force increase facilitated the breakage of the R995-D723 salt bridge and the activation of αⅡbβ3 integrin.Conclusions The force-induced allostery of αⅡbβ3-MP enhanced the complex mechanical strength and delayed FLNa-Ig21 dissociation from αⅡbβ3-CT.After breaking through the 20 pN threshold,force positively regulated the activation of αⅡbβ3 integrin.These results provide insights into the molecular mechanism of αⅡbβ3 activation and the development of related targeted drugs.
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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.
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Objective To investigate the effect of dynamic monitoring of occlusal force on the final therapeutic effect and the change of periodontal supporting tissue during combined periodontal orthodontic treatment.Methods The periodontal clinical index of 20 patients with traditional periodontal orthodontic treatment and 20 patients with combined periodontal orthodontic treatment assisted by T-Scan Ⅲ and Anycheck digital occlusion analysis system were compared before,during and after treatment,as well as the changes of bite force,bite time and tooth mobility in the experimental group.Results The depth of periodontal pocket(PD),loss of attachment(AL),bleeding index(BI)and tooth looseness were significantly reduced after combined periodontal orthodontic treatment in both groups.In the control group,the percentage of anterior and posterior biting force changed obviously,and the occlusion force balance was improved.Conclusion The combined treatment of periodontitis and orthodontics can improve the periodontal tissue of patients with periodontitis,and T-Scan system can observe and guide the adjustment of occlusal and better achieve occlusion force balance.
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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.
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Objective:To investigate the role of a simple Nomogram model in evaluating the severity of mycoplasma pneumoniae pneumonia (MPP) in adults.Methods:The clinical data of 162 patients with MPP who received treatment in Wenzhou Central Hospital from March 2015 to October 2022 were retrospectively analyzed. These patients were divided into a severe group ( n = 67) and a common group ( n = 95) according to whether they were diagnosed with severe MPP. The clinical data of patients were recorded. Fourteen clinical variables were screened, including age, sex, onset season, fever, heat peak, fever duration, cough duration, white blood cell count, percentage of neutrophils, percentage of lymphocytes, hemoglobin, platelet count, C-reactive protein, and procalcitonin. Multivariate logistic regression analysis of statistically significant variables in univariate analysis was performed. The Nomogram model was constructed with the R language software package (version 3.6.2). The model was verified with a calibration curve and receiver operating characteristic curve. Results:Univariate analysis results showed that in the severe group, the fever peak ( Z = 5.03, P < 0.001) was higher, fever duration ( χ2 = 27.55, P < 0.001), and cough duration ( χ2 = 28.72, P < 0.001) were longer, white cell count ( t = 2.93, P = 0.004), percentage of neutrophils ( t = 9.08, P < 0.001), C-reactive protein ( t = 35.05, P < 0.001), and procalcitonin level ( t = 15.09, P < 0.001) were greater compared with the common group. The percentage of lymphocytes ( t = 1.16, P < 0.001), hemoglobin level ( t = 1.22, P < 0.001), and platelet count ( t = 2.82, P < 0.001) in the severe group were significantly lower than those in the common group. Multivariate logistic regression analysis results showed that heat peak, cough duration, and C-reactive protein were positively correlated with the severity of MPP (all P < 0.05). The percentage of lymphocytes, hemoglobin concentration, and platelet count were negatively correlated with the severity of MPP (all P < 0.05). The establishment and validation results of the Nomogram model showed that the accuracy of the model was good, with a sensitivity of 88.73%, a specificity of 77.61%, and a C-index of 0.904. Conclusion:Heat peak, cough duration, percentage of lymphocytes, platelet count, and C-reactive protein are closely related to the severity of early MPP. A simple Nomogram model can be one of the tools for early assessment of the severity of MPP.
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Objective To explore how hyaluronic acid ( HA) in extracellular matrix regulates the adhesion ofCD44+tumor cells. Methods MDA-MB-231 cells or HL60 cells were perfused in a parallel plate chamber. Themovement of cells over immobilized HA was observed and analyzed to obtain the characteristics of cell adhesionand rolling. Results The adhesion number of MDA-MB-231 cells on HA substrate was positively regulated by HAconcentration, but not by HA molecular weight. Compared with physically adsorbed HA, immobilized HA byavidin-biotin could significantly improve the cell adhesion ratio. With the increase of shear stress in the range of30-50 mPa, the rolling velocity of cells increased and the adhesion ratio decreased, but the tether lifetime of cellswas not affected. In the same flow field, compared with MDA-MB-231 cells, HL60 cells with low expression ofCD44 rolled more quickly on immobilized HA, with shorter tether lifetime and much lower adhesion ratio(<1. 5% ). Conclusions Fluid shear stress might mediate the rolling velocity of MDA-MB-231 cells by regulatingthe CD44-HA association rate rather than their dissociation rate. The interaction between CD44 and HA is involved in the initial adhesion of HL60 cells, but it does not play a major role. This study will provide references for the design of anti-tumor drugs.
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Objective To develop a simplified phantom for the calibration of whole-body counters. Methods A simplified phantom design method for the calibration of whole-body counters was established based on the process and method of calibrating whole-body counters. By using the established method and Monte Carlo method, a simplified phantom including the total body, thyroid, lungs, and gastrointestinal tract was designed to calibrate the ORTEC-Stand FAST II whole-body counter. The simplified phantom was compared with the BOMAB phantom through experimental measurements. Results Within the range of 50 keV to 2 MeV, for rays of the same energy in the same organ of the simplified phantom and BOMAB phantom, the simulated data of detection efficiency by whole-body counting showed an error within 5%, and the experimental measurements showed an error within 10%. Conclusion We developed a simplified phantom for the calibration of the whole-body counter, demonstrating the feasibility of using the simplified phantom instead of a physical body phantom for whole-body counter calibration, which can greatly facilitate whole-body counter calibration for internal radiation monitoring.
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The binding of talin-F0 domain to ras-related protein 1b (Rap1b) plays an important role in the formation of thrombosis. However, since talin is a force-sensitive protein, it remains unclear whether and how force regulates the talin-F0/Rap1b interaction. To explore the effect of force on the binding affinity and the dynamics mechanisms of talin-F0/Rap1b, molecular dynamics simulation was used to observe and compare the changes in functional and conformational information of the complex under different forces. Our results showed that when the complex was subjected to tensile forces, there were at least two dissociation pathways with significantly different mechanical strengths. The key event determining the mechanical strength difference between the two pathways was whether the β4 sheet of the F0 domain was pulled away from the original β1-β4 parallel structure. As the force increased, the talin-F0/Rap1b interaction first strengthened and then weakened, exhibiting the signature of a transition from catch bonds to slip bonds. The mechanical load of 20 pN increased the interaction index of two residue pairs, ASP 54-ARG 41 and GLN 18-THR 65, which resulted in a significant increase in the affinity of the complex. This study predicts the regulatory mechanism of the talin-F0/Rap1b interaction by forces in the intracellular environment and provides novel ideas for the treatment of related diseases and drug development.
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Molecular Dynamics Simulation , TalinABSTRACT
In resting platelets, the 17 th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 rd phenylalanine (PHE 563-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
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Filamins/metabolism , Platelet Glycoprotein GPIb-IX Complex/metabolism , Molecular Dynamics Simulation , Ligands , Protein Binding , Blood Platelets/metabolism , von Willebrand Factor/metabolismABSTRACT
Objective:To compare the difference between breast bracket combined with polyurethane foam and single polyurethane foam in the accuracy of immobilization, providing a better immobilization for breast cancer radiotherapy.Methods:Fifty breast cancer patients who received radiotherapy in Sun Yat-sen University Cancer Center from March 2021 to July 2021 were selected. Among them, 25 patients were immobilized with polyurethane foam (foam group), and the other 25 patients were immobilized with polyurethane foam combined with breast bracket (combination group). All patients were scanned by CBCT once a week to obtain setup errors in the SI, LR and AP directions for t-test. The formula M PTV=2.5 Σ+0.7 σ was used to calculate the margin of the planning target volume(M PTV). Results:The setup errors in the foam group were SI (2.0±3.26) mm, LR (0.88±2.76) mm, AP (1.22±3.55) mm, Rtn -0.24°±0.85°, Pitch 0.16°±1.11°, Roll -0.32°±1.05°, and the M PTV were 6.75 mm, 8.46 mm and 8.73 mm, respectively. The setup errors in the combination group were SI (1.0±3.01) mm, LR (0.62±2.74) mm, AP (1.82±3.21) mm, Rtn 0.64°±0.59°, Pitch 0.71°±1.22°, Roll 0.29°±0.73°, and the M PTV were 6.35 mm, 7.47 mm, and 7.61 mm, respectively. After comparing the setup errors in the three-dimensional directions between two groups, the t value of LR, SI, AP and Rtn, Pitch, Roll was -4.304, -2.681, 1.384, and -9.457, -3.683, -5.323, respectively. And the differences in the LR, SI, Rtn, Pitch and Roll directions were statistically significant (all P<0.05). Conclusions:The immobilization effect of polyurethane foam combined with breast bracket is better and the M PTV is also smaller than those of polyurethane foam alone. Therefore, it is recommended to use polyurethane foam combined with breast bracket for immobilization in breast cancer radiotherapy.
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Objective:Before the radiotherapy was performed, patients with pelvic tumors were analyzed for the consistency of bladder filling in the three steps of " Immobilization" , " CT Simulation" and " X-ray Simulation" .Methods:In 2014, 105 patients (68 cases of cervical cancer, 32 cases of rectal cancer, 3 cases of vaginal cancer and 2 cases of prostate cancer) with pelvic tumor radiotherapy were randomly assigned to monitor bladder urine volume to a target urine volume of 400 ml. First, patient were exhorted to empty the bladder, and the bladder volume meter BVI 9400 was used to measure the urine volume of the patient after emptying of the bladder. The patient immediately drank about 540 ml of water and suppressed urine, measurements were taken every 0.5 h. At the same time, when the patient complained of " urgency of urine" , bladder urine volume would be measured again and the time would also be recorded. Every other half an hour (emptying, 0.5 h after emptying, 1.0 h after emptying), when complaining of " urgency of urine" , when actually performing urine volume and time were described as: U 0 and t 0, U 0.5 and t 0.5, U 1.0 and t 1.0, U t and t, U T and T. Results:There was a statistically significant difference in gender and age, and women had stronger ability to urinate than men U 1.0( P=0.003), young people had stronger ability to urinate than middle-aged U 1.0( P=0.002). In the three-step comparison, there was no statistically difference between 1 hour after emptying urine volume U 1.0( P=0.177) and the actually performing urine volume U T ( P=0.052). And the final urine volume was concentrated at 298-526 ml. After the patient emptied the urine volume and complained of " urgency of urine" , the time slot was t=(75.2±49.9) min, with the urine volume of U t=(331.2±140.3) ml. And there was no statistically difference between U t and U T ( P=0.198) at X-ray Simulation. Conclusions:The patient emptied the bladder and immediately drank 540 ml of water. After 1 hour of suppressing urine, he complained of " urgency of urine" and achieved the target urine volume (400 ml). At this time, the bladder urine volume U 1.0 was consistency in the immobilization, CT Simulation, and X-ray Simulation.
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Objective:Exploring the " bottle neck" factors in the scientific research management of recipient hospitals, making good use of counterpart support resources to help identifying appropriate, tailored strategies of scientific research management that might improve the research capacity of recipient hospitals.Methods:Data were collected according to questionnaire survey and on-site interview, ABC classification method were used to perform statistical analysis, and " bottleneck" factors that constraint the scientific research work of the recipient hospital were summarized.Results:" Insufficient scientific research skills and lacking of talents" and " lacking of scientific research environment and recognition" are the two most prominent factors that negatively affect the scientific research capacity building of the recipient hospitals, followed closely by " the out-dated scientific research policies and lacking support from the hospital leadership" , insufficient of research platform or resources including research funding, as well as other factors. Based on such findings, this article took the First People's Hospital of Kashgar (Guangdong counterpart support) as an example, and tried to discuss some corresponding measures on how to make good use of counterpart support resources.Conclusions:The ABC classification method were used to identify the main " bottleneck" factors, and a series of effective measures that help to making good use of counterpart support resources were explored. As a result, the efficiency of the scientific research management of the recipient hospitals, which in terms of management methods, management concepts and management models, were improved.
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Primary hospitals are engaged in such responsibilities as diagnosis and treatment of endemic diseases and common illnesses of the locality, as well as relevant research work which bears more prominent importance than ever before. Given the importance of research, the hospitals are mostly plagued by such setbacks as obsolete research management concepts, poor experiences, poor perception of research, poor professional competency and lack of academic exchange among the medical workers. A primary hospital had set up a novel management mechanism, featuring " full-staff involvement, full-process supervision and full-dimensional guidance" , and " tight formal examination and tight content examination" . This mechanism has been in place since 2016 in research project management practice, achieving such progresses as significant rise in the number of research project applications, that of approved projects, and project implementation capabilities.Future improvements in this regard should be made in higher pertinence, optimized management flow and better research service system.
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Neutrophil extracellular traps (NETs) play an important role in the formation of immunothrombosis. However, how vascular endothelial cells mediate the formation of NETs has not been fully understood. We stimulated neutrophils firmly attached on the endothelial cell surface intercellular adhesion molecule-1 (ICAM-1) with lipopolysaccharide (LPS) or phorbol-12-myristate-13-acetate (PMA) for 4 h, then labeled NETs-DNA with Sytox green dye and the formation of NETs was observed by fluorescent microscopy. The area and fluorescence intensity of NETs-DNA were analyzed to quantify the formation of NETs. The results showed that both PMA and LPS were able to induce firmly adhered neutrophils on ICAM-1 to produce NETs. NETs induced by PMA were independent of neither β2 integrin lymphocyte function-associated antigen-1 (LFA-1) nor macrophage antigen complex-1 (Mac-1). In contrast, LPS-stimulated NETs were mediated by Mac-1 integrin, but not by LFA-1. After inhibition of actin filaments or Talin-1, the formation of NETs irrespective of the stimulus was significantly reduced. This study reveals the mechanism of the direct interaction between neutrophils and endothelial cells to produce NETs under inflammatory conditions, providing a new theoretical basis for the treatment of related diseases and the development of new drugs.
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Cytoskeletal Proteins , Endothelial Cells , Extracellular Traps , Integrins , Intercellular Adhesion Molecule-1 , Lipopolysaccharides/pharmacology , Macrophages , NeutrophilsABSTRACT
Fibrinogen (Fg) in human plasma plays an important role in hemostasis, vascular repair and tissue integrity. The surface chemistry of extracellular matrix or biological materials affects the orientation and distribution of Fg, and changes the exposure of integrin binding sites, thereby affecting its adhesion function to platelets. Here, the quantity, morphology and side chain exposure of Fg adsorbed on hydrophilic, hydrophobic and avidin surfaces were measured by atomic force microscopy (AFM) and flow cytometry (FCM), then the rolling behavior of platelets on Fg was observed through a parallel plate flow chamber system. Our results show that the hydrophobic surface leads to a large amount of cross-linking and aggregation of Fg, while the hydrophilic surface reduces the adsorption and accumulation of Fg while causing the exposure and spreading of the α chain on Fg and further mediating the adhesion of platelets. Fg immobilized by avidin / biotin on hydrophilic surface can maintain the monomer state, avoid over exposure and stretching of α chain, and bind to the platelets activated by the A1 domain of von Willebrand factor instead of inactivated platelets. This study would be helpful for improving the blood compatibility of implant biomaterials and reasonable experimental design of coagulation
Subject(s)
Humans , Adsorption , Blood Platelets , Fibrinogen , Platelet Adhesiveness , von Willebrand FactorABSTRACT
Objective To investigate the effects of fluid shear stress on rolling adhesion of neutrophils on immobilized platelets under flows. Methods Experiments were performed at the parallel plate flow chamber. Platelets were adhered to the functionalized flow chamber bottom which were coated with vWF-A1 first, and then washed with PBS under wall shear stress (WSS) of 1 Pa for different time (0 min, 2.5 min, 7.5 min). A high-speed camera was used to observe and record the rolling adhesion events of neutrophils on immobilized platelets under 50 mPa WSS, and the adhesion parameters such as the number of adhesion events, the tether lifetime of cells and rolling velocity. Results Neutrophils could specifically bind to the immobilized platelets on vWF-A1-coated bottom of the flow chamber. Mechanical stimulation on immobilized platelets had no effects on the tether lifetime of neutrophils on the platelets, but up-regulated the adhesive ratio of neutrophils on the platelets and slowed down the rolling of neutrophils on the platelets. Conclusions Mechanical stimulation on the immobilized platelets will significantly make the circulating neutrophils to be captured easily and promote the rolling adhesion of neutrophils on platelets.
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Objective To investigate the interaction between von Willebrand factor (vWF) A1 and A3 domain, and type 2 M mutant W1745C-A3 effect on thermal stability and mechanical stability of A3/A1. Methods The crystal structures of A1 and A3 were downloaded from Protein Data Base (PDB). The wild-type (WT) A3/A1 structure was obtained by using SwarmDock Server, then W1745C-A3/A1 mutant was constructed by replacing the Trp1745 with Cys1745 in A3/A1. Through steered molecular dynamics simulation, formation and evolution of hydrogen bond and salt bridge between A1 and A3 interfaces were observed, and the differences in conformation, disrupted force and dissociation time between WT-A3/A1 and W1745C-A3/A1 were compared. Results There were 5 pairs of hydrogen bonds with survival rate > 0-2 and 1 pair of salt bridge with survival rate > 0-5 between A1 and A2. The W1745C-A3/A1 complex could withstand greater disrupted force and longer dissociation time compared with WT-A3/A1, by improving the stability of hydrogen bonds and increasing 1 pair of stable salt bridge. Conclusions The interaction between A1 and A3 would hinder the binding sites of A1 to GPIbα, and the W1745C-A3 mutation would further reduce the affinity of A1 to platelets. These results provide references for revealing the molecular mechanism of von Willebrand diseases in the clinic and developing the corresponding drugs targeted to hemostasis disorders.
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Objective To investigate the mechanism of mechano-chemical coregulation in chemokine-induced calcium response of Jurkat T cells under fluid shear stress (FSS). Methods By using parallel-plate flow chamber combined with fluorescence microscope, the calcium response of Jurkat T cells on CXCL12 was observed to extract the corresponding characteristic parameters under static or flow state, with or without extracellular Ca2+, respectively. Results Immobilized CXCL12 could induce firm adhesion of the circulating Jurkat T cells, and the arrested cells increased with the increase of CXCL12 concentration. Force could trigger the calcium response of Jurkat T cells and sharply raised the activation ratio from 4% up to 75% when the FSS increased from 0 to 20 mPa. Under 20 mPa FSS, extracellular Ca2+ could stimulate quickly the calcium response by shortening the delay time (about 23 s), and enhance calcium intensity by prolonging the climbing time (about 7 s) and half time (about 20 s). Conclusions The cooperation between FSS and extracellular Ca2+ would accelerate and enhance CXCL12-mediated-calcium response of Jurkat T cells, which indicated a fast mechanosensitive pathway through ‘extracellular calcium influx-intracellular calcium store release’. The research results would contribute to understanding the process of T cells activation and providing the clue for relevant pathological and drug research.
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Objective:To analyze the dynamic characteristics of rodents population density distribution in plague foci of Yinchuan City, Ningxia, and to provide reference for early warning of the plague.Methods:The plague surveillance results and epidemic reports of Yinchuan City from 2015 to 2018 were collected retrospectively, and the data were obtained from the database of Yinchuan City Center for Disease Control and Prevention. Descriptive method was used to analyze the species, number, density, fleas, vector index, etiology and serology results of rodents in the plague foci.Results:From 2015 to 2018, 4 families, 8 genera, 13 species, and 8 843 rodents were captured in the plague foci of Yinchuan City, and Meriones unguiculatus (4 557 rodents) was the dominant species. The survey area of host animal density was 1 459 hm 2, 3 805 rodents were captured, and the average density was 2.61/hm 2, of which the Meriones unguiculatus density was 1.98/hm 2. A total of 41 488 traps of nocturnal rodents were investigated, and 2 660 rodents were captured, with an average capture rate of 6.41%. A total of 6 952 fleas were obtained, belonging to 4 families, 7 genera, and 8 species; Xenopsylla conformis conformis (4 597 fleas) and Nosopsyllus laeviceps kuzenkovi (1 761 fleas) were the dominant species. Among them, there were 2 286 flea-infected rodents, the body flea-infected rate was 25.85% (2 286/8 843), and the body flea-infected index was 0.76. A total of 220 gerbils nests were investigated, and the nest flea-infected rate was 34.55% (76/220), and the nest flea-infected index was 0.98. No plague bacterium was isolated by pathogen detection of rodents and fleas. The results of indirect hemagglutination test were all negative. Conclusion:The Meriones unguiculatus is the dominant species in the plague foci of Yinchuan City, the average density is still high, attention should be paid to the occurrence of plague outbreaks.
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Objective:To evaluate the efficacy and safety of Tyrosine Kinase Inhibitors (TKIs) combined with stereotactic body radiation therapy(SBRT) in the treatment of renal cell carcinoma (RCC) patients with bone metastasis.Methods:The clinical data of 80 RCC patients with bone metastasis in Sun Yat-sen University Cancer Center from April 2010 to April 2020 were analyzed retrospectively. Among them, 64 patients were medium or high risk according to the International Metastatic Renal Cell Carcinoma Database Consortium(IMDC) score. Twenty-four patients received TKI therapy alone(Group A), and the other 56 cases received TKIs combined with SBRT to bone metastastic lesions (Group B).Results:The median follow-up period was 20.7 months (4.8-115.6 months), 70 patients received second or third-line targeted drug therapy, and 4 patients in group A and 15 patients in group B received TKI plus immunotherapy. Fifty-four patients had symptoms of bone pain before radiotherapy, 46 patients were satisfied with the analgesic effect after SBRT treatment. Twelve patients got complete response (CR) after bone lesions, and 32 patients achieved partial response (PR). Forty patients died of disease progression during follow-up. The median OS was: 20.7 months vs not reached(Group A vs. Group B), and the 2-y OS and 5-y OS were 50% vs. 62%, and 19% vs. 56%, respectively ( P=0.006). There were only 2 patients (3.6%) had grade 3 SBRT related adverse events. Conclusions:SBRT combined with TKIs improved the quality of life and prolonged the overall survival of RCC patients with bone metastasis.