ObjectiveBola-like short peptides exhibit novel self-assembly properties due to the formation of peptide dimers via hydrogen bonding interactions between their C-terminals. In this configuration, hydrophilic amino acids are distributed at both terminals, making these peptides behave similarly to Bola peptides. The electrostatic repulsive interactions arising from the hydrophilic amino acids at each terminal can be neutralized, thereby greatly promoting the lateral association of β-sheets. Consequently, assemblies with significantly larger widths are typically the dominant nanostructures for Bola-like peptides. To investigate the effect of hydrophilic amino acids on the self-assembly behavior of Bola-like peptides, the peptides Ac-RI₃-CONH₂ and Ac-HI₃-CONH₂ were designed and synthesized using the Bola-like peptide Ac-KI₃-CONH₂ as a template. Their self-assembly behavior was systematically examined. MethodsAtomic force microscopy (AFM) and transmission electron microscopy (TEM) were employed to characterize the morphology and size of the assemblies. The secondary structures of the assemblies were analyzed using circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy. Small-angle neutron scattering (SANS) was used to obtain detailed structural information at a short-length scale. Based on these experimental results, the effects of hydrophilic amino acids on the self-assembly behavior of Bola-like short peptides were systematically analyzed, and the underlying formation mechanism was explored. ResultsThe aggregation process primarily involved three steps. First, peptide dimers were formed through hydrogen bonding interactions between their C-terminals. Within these dimers, the hydrophilic amino acids K, R, and H were positioned at both terminals, enabling the peptides to self-assemble in a manner similar to Bola peptides. Next, β-sheets were formed via hydrogen bonding interactions along the peptide backbone. Finally, self-assemblies were generated through the lateral association of β-sheets. The results demonstrated that both Ac-KI₃-CONH₂ and Ac-RI₃-CONH₂ could self-assemble into double-layer nanotubes with diameters of approximately 200 nm. These nanotubes were formed by the edge fusion of helical ribbons, which initially emerged from twisted ribbons. Notably, the primary assemblies of these peptides exhibited opposite chirality: nanofibers formed by Ac-KI₃-CONH₂ displayed left-handed chirality, whereas those formed by Ac-RI₃-CONH₂ exhibited right-handed chirality. This reversal in torsional direction was primarily attributed to the different abilities of K and R to form hydrogen bonds with water. In contrast, Ac-HI₃-CONH₂ formed narrower twisted ribbons with a significantly reduced width of approximately 30 nm, which was attributed to the strong steric hindrance caused by the imidazole rings. The multilayer height of these ribbons was mainly due to the unique structure of the imidazole rings, which can function as both hydrogen bond donors and acceptors, thereby promoting aggregate growth in the vertical direction. ConclusionThe final morphology of the self-assemblies resulted from a delicate balance of various non-covalent interactions. By altering the types of hydrophilic amino acid residues in Bola-like short peptides, the relative strength of non-covalent interactions that drive assembly formation can be effectively regulated, allowing precise control over the morphology and chirality of the assemblies. This study provides a simple and effective approach for constructing diverse self-assemblies and lays a theoretical foundation for the development of functional biomaterials.

Aim To investigate the mechanism of ligu aged 2 months of the same strain were used as the constilide (LIG) in delaying the senescence of auditory trol (Ctrl) group. Auditory brainstem response test was cortex and treating central presbycusis. Methods used to detect the auditory threshold of mice before and Forty C57BL/6J mice aged 13 months were randomly di after treatment. Levels of serum MDA and activity of vided into ligustilide low-dose(L-LIG) group, ligustil serum SOD were detected to display the level of oxidative ide medium-dose (M-LIG) group, ligustilide high-dose stress. The pathological changes of auditory cortex were (H-LIG) group and aging (Age) group, and 10 mice observed by HE staining. Ferroptosis was observed by

Objective To evaluate the characteristics of different antigen-specific T cell immune responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)after inoculation with 2 doses of SARS-CoV-2 inactivated vaccine for 12 months.Methods Fifteen healthy adults were enrolled in this study and blood samples collected at 12 months after receiving two doses of SARS-CoV-2 inactivated vaccine.The level and phenotypic characteristics of SARS-CoV-2 antigen-specific T lymphocytes were detected by activation-induced markers(AIM)based on polychromatic flow cytometry.Results After 12 months of inoculation with 2 doses of SARS-CoV-2 inactivated vaccine,more than 90%of adults had detectable Spike and Non-spike antigen-specific CD4+ T cells immune responses(Spike:14/15,P=0.0001;Non-spike:15/15,P<0.0001).80%of adults had detectable Spike and Non-spike antigen-specific CD8+ T cells immune responses(Spike:12/15,P=0.0463;Non-spike:12/15,P=0.0806).Antigen-specific CD4+ T cells induced by SARS-CoV-2 inactivated vaccination after 12 months were composed of predominantly central memory(CM)and effector memory 1(EM1)cells.On the other hand,in terms of helper subsets,antigen-specific CD4+ T cells mainly showed T helper 1/17(Th1/17)and T helper 2(Th2)phenotypes.Conclusions SARS-CoV-2 inactivated vaccination generates durable and extensive antigen-specific CD4+ T cell memory responses,which may be the key factor for the low proportion of severe coronavirus disease 2019(COVID-19)infection in China.

ObjectiveTePixD (Tll0078) is a blue light-using flavin (BLUF) photoreceptor protein from Thermosynechococcus elongatus BP-1. TePixD protein has a conserved Tyr8-Gln50-Met93 triad around the FAD pocket to mediate the proton-coupled electron transfer (PCET) process. But the detailed light response mechanism needs further study. We aimed to elucidate the structure and biochemical properties of TePixD mutants at key light response sites to analyze the light response process of TePixD. MethodsWe employed X-ray crystallography to resolve the crystal structure of the TePixD Y8F mutant. The side chain of Tyr8 is involved in PCET while Phe8 in mutation loses the function due to the loss of its hydroxyl group. We compared the structure of TePixD Y8F mutation to TePixD wild type (WT) and its homology protein SyPixD Y8F. Using multi-angle light scattering (MALS), we analyzed the oligomerization of multiple TePixD mutations (Y8F, Q50L, W91F, Y8F/W91F, and Q50L/W91F), focusing specifically on mutational sites that are critical residues for the protein’s photo response to dark and light conditions. ResultsWe resolved the crystal structure of TePixD Y8F mutant at a resolution of 2.54 Å and found that it shares a similar overall structure with the TePixD WT but exhibits significant differences from the SyPixD Y8F structure. Biochemical analysis revealed differences in molecular mass and elution profiles between the TePixD mutants and the WT under dark and light conditions, indicating the perturbation on the light-induced conformational change by the mutants. ConclusionOur structure determination and biochemical analyses will add information to reveal the light response mechanism of BLUF proteins.

Objective To investigate the clinical effect of modified suspension reduction method combined with percuta-neous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures.Methods From February 2020 to October 2021,92 patients with thoracolumbar osteoporotic compression fracture were treated by percutaneous vertebroplasty.According to different treatment methods,they were divided into the observation group and the control group.The observation group was treated with modified suspension reduction and then percutaneous vertebroplasty,while the control group was treated with percutaneous vertebroplasty alone.The observation group(47 cases),including 20 males and 27 females,the age ranged from 59 to 76 years old with an average of(69.74±4.50)years old,fractured vertebral bodies:T10(2 cases),T11(7 cases),T12(19 cases),L1(14 cases),L2(5 cases);the control group(45 cases),including 21 males and 24 females,the age ranged from 61 to 78 years old with an average of(71.02±3.58)years old,fractured vertebral bodies:T10(3 cases),T11(8 cases),T12(17 cas-es),L1(12 cases),L2(5 cases);The leakage of bone cement were observed,the visual analogue scale(VAS),Oswestry lumbar dysfunction index(ODI),anterior vertebrae height(AVH),Cobb angle of kyphosis and the amount of bone cement injected before and after operation were recorded and compared between the two groups.Results All patients were followed up,ranged from 6 to1O with an average of(8.45±1.73)months.Two patients ocurred bone cement leakage in observation group and 3 pa-tients in control group.AVH of observation group increased(P＜0.05)and Cobb angle of injured vertebrae decreased(P＜0.05).Cobb angle of injured vertebrae and AVH of the control group were not significantly changed(P＞0.05).Cobb angle of injured vertebrae of the observation group was lower than that of control group(P＜0.05)and AVH was higher than that of the control group(P＜0.05).In the observation group,VAS before operation and 1 week,3 and 6 months after operation respective-ly were(7.32±1.05)scores,(3.56±1.18)scores,(1.83±0.67)scores,(1.27±0.34)scores,and ODI were(40.12±14.69)scores,(23.76±10.19)scores,(20.15±6.39)scores,(13.45±3.46)scores.In the control group,VAS before operation and 1 week,3 and 6 months after operation respectively were(7.11±5.26)scores,(3.82±0.68)scores,(1.94±0.88)scores,(1.36± 0.52)scores,and ODI were(41.38±10.23)scores,(25.13±14.22)scores,(20.61±5.82)scores,(14.55±5.27)scores.The scores of VAS and ODI after operation were lower than those before operation(P＜0.05),but there was no significant difference between the two groups(P＜0.05).Conclusion Modified suspension reduction method combined with PVP surgery for osteo-porotic thoracolumbar compression fractures has achieved good clinical results,which can effectively relieve lumbar back pain,restore vertebral height,correct kyphosis,improve lumbar function and patients'quality of life.

Objective To observe the efficacy and safety of Morinda officinalis oligosaccharides in the continuation treatment of mild and moderate depression.Methods An open,single-arm,multi-center design was adopted in our study.Adult patients with mild and moderate depression who had received acute treatment of Morinda officinalis oligosaccharides were enrolled and continue to receive Morinda officinalis oligosaccharides capsules for 24 weeks,the dose remained unchanged during continuation treatment.The remission rate,recurrence rate,recurrence time,and the change from baseline to endpoint of Hamilton Depression Scale(HAMD),Hamilton Anxiety Scale(HAMA),Clinical Global Impression-Severity(CGI-S)and Arizona Sexual Experience Scale(ASEX)were evaluated.The incidence of treatment-related adverse events was reported.Results The scores of HAMD-17 at baseline and after treatment were 6.60±1.87 and 5.85±4.18,scores of HAMA were 6.36±3.02 and 4.93±3.09,scores of CGI-S were 1.49±0.56 and 1.29±0.81,scores of ASEX were 15.92±4.72 and 15.57±5.26,with significant difference(P＜0.05).After continuation treatment,the remission rate was 54.59％(202 cases/370 cases),and the recurrence rate was 6.49％(24 cases/370 cases),the recurrence time was(64.67±42.47)days.The incidence of treatment-related adverse events was 15.35％(64 cases/417 cases).Conclusion Morinda officinalis oligosaccharides capsules can be effectively used for the continuation treatment of mild and moderate depression,and are well tolerated and safe.

Objective To observe the therapeutic effect and mechanism of acupuncture at Zusanli-Zhongwan combined matching points on rats with exercise-induced stress gastric ulcer.Methods Forty male SD rats were randomly divided into blank group,model group,acupuncture group and Omeprazole group,with 10 rats in each group.Except for the blank group,the rats in the other groups were used to construct the model of exercise stress gastric ulcer by daily exhaustive swimming.After successful modeling,the acupuncture group was intervened by acupuncture at Zusanli(ST36)and Zhongwan(RN12),once a day,10 minutes each time.Rats in the Omeprazole group were given Omeprazole Enteric-Coated Tablets distilled water suspension by gavage two hours before daily swimming.After continuous 7-day intervention,the overall state and behavior of rats were observed,the gastric mucosal injury index was calculated by Guth method,the pathological morphology of gastric mucosa was observed by hematoxylin-eosin(HE)staining,the contents of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX)and malondialdehyde(MDA)in serum were correspondingly determined by WST-1 method,colorimetry and TBA method,respectively,enzyme-linked immunosorbent assay(ELISA)was used to detect the contents of gastrin(GAS),somatostatin(SS),tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1β),interleukin-6(IL-6)and interleukin-10(IL-10)in serum,the expression levels of epidermal growth factor receptor(EGFR),matrix metalloproteinase 3(MMP3),nuclear factor erythroid-related factor 2(NRF2),heme oxygenase 1(HO-1)and mitochondrial SOD2,TNF-α,IL-1β,IL-6 and IL-10 mRNA in gastric mucosa were detected by real-time fluorescence quantitative polymerase chain reaction(qPCR).Results Compared with the blank group,the body mass of rats in the model group was increased slowly,the activity distance and activity in the open field test were decreased,the gastric mucosal ulcer index was increased significantly,the gastric mucosal function indexes involving GAS level was increased and SS level was decreased in serum,the mRNA expression level of EGFR in gastric mucosa was decreased and the mRNA expression level of MMP3 in gastric mucosa was increased.The serum levels of antioxidant substances SOD and GSH-PX were decreased significantly,and the serum level of oxidation product MDA was increased significantly.The mRNA expression levels of antioxidant genes NRF2,HO-1 and SOD2 in gastric mucosa were significantly decreased.The serum contents and the gastric mucosa mRNA levels of inflammatory factors TNF-α,IL-1α,IL-6 were significantly increased,while the serum content and the gastric mucosa mRNA level of IL-10 were significantly decreased.The differences were statistically significant(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed obvious gastric mucosal injury.Compared with the model group,the above indexes in the acupuncture group and the Omeprazole group were significantly improved(P＜0.05 or P＜0.01 or P＜0.001).HE staining showed that the gastric mucosal injury was significantly reduced.Conclusion Acupuncture at Zusanli-Zhongwan combined matching points can reduce the local oxidative stress and inflammatory response in rats with exercise-induced stress gastric ulcer,reduce gastric mucosal injury,improve the emotional state of rats,and maintain the overall vitality of rats.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

The diaphragm is one of the most important respiratory muscles in the human body,of which 60%-80%of the function of the respiratory muscle is played by the diaphragm.Mechanical ventilation is a common respiratory support method for severely ill patients in clinical.However,improper use of the ventilator can also lead to ventilator-induced diaphragm dysfunction(VIDD)while maintaining patients'respiratory function.The pathogenesis of VIDD is mainly induced by mechanical ventilation leading to diaphragmatic mitochondrial oxidative stress(MOS).In addition,the protein degradation of the ubiquitin-proteasome system(UPS),autophagy,changes in calpain activity,calcium,and cytokines also play important roles in the process of VIDD.In-depth understanding the pathological mechanism of VIDD is beneficial to prevent and treat VIDD.This article reviews the research progress of the potential etiology(improper use of ventilator,age,nutritional and metabolic status,coronary disease,drug factors)and pathogenesis(mitochondrial oxidative stress,autophagy of diaphragm cells,activation of calpain,and increase of intracellular calcium)of VIDD,so as to provide reference for the treatment of VIDD.

Objective:To investigate the knowledge of Sixth Chinese national consensus report on the management of Helicobacter pylori infection ( treatment excluded) (hereinafter referred to as sixth national consensus) and 2022 Chinese national clinical practice guideline on Helicobacter pylori eradication treatment (hereinafter referred to as the guideline)among medical staff from general hospitals in Hainan. Methods:From February 20 to May 7, 2023, a questionnaire survey on the diagnosis and treatment of Helicobacter pylori ( H. pylori) infection was conducted among 1 463 medical staff from 15 general hospitals in Hainan Province. The questionnaire was drawn up according to the sixth national consensus and the guideline, covering knowledge of 6 sections, induding H. pylori related diseases, detection of H. pylori, eradication, prevention and influence factors of eradication of H. pylori, etc. Chi-square test was used for statistical analysis. Results:A total of 1 463 valid questionnaires were collected with the effective responsive rate of 100.00%.The 1 463 subjects included 225 gastroenterologists and 1 238 other medical staff(including 503 physicians from other departments, 264 surgeons and 471 medical technologists and pharmacists). About 78.67%(177/225)of gastroenterologists agreed that the overall infection rate of H. pylori in China was more than 20%, the awareness rate was higher than that of other medical staff (physicians from other departments 65.41%(329/503), surgeons 61.74%(163/264), medical technologists and pharmacists 60.30%(284/471); the following datas were sorted by this position), and the difference was statistically significant ( χ2=30.97, P<0.001). About 51.11%(115/225) of gastroenterologists considered that H. pylori serological antibody test could not be used as a diagnostic method for current infection, the awareness rate was higher than that of other medical staff(22.07%(111/503), 14.02%(37/264), 12.31%(58/471)), and the difference was statistically significant( χ2 =152.66, P<0.001). Proton pump inhibitor and potassium-competitive acid blocker should be discontinued for 2 weeks, and antibiotics and bismuth should be discontinued for 4 weeks before urea breath test, and the awareness rates of gastroenterologists were higher than those of other medical staff (38.67%(87/225) vs. 23.26%(117/503), 19.70%(52/264), 18.47%(87/471); 60.89%(137/225) vs. 26.64%(134/503), 25.76%(68/264), 23.78%(112/471)), and the differences were statistically significant ( χ2 =133.70 and 165.51, both P<0.001). For refractory H. pylori infection, 98.67%(222/225)of gastroenterologists agreed with the individualized diagnosis and treatment of H. pylori infection should be guided by bacterial culture, antibiotic susceptibility test or drug resistance gene test, and the awareness rate was higher than that of other medical staff (91.85%(462/503), 93.56%(247/264), 93.21%(439/471)), and the difference was statistically significant( χ2=20.55, P=0.002). About 70.67% (159/225) of gastroenterologists recommended a bismuth containing quadruple regimen, 80.44% (181/225) supported a 10 to 14 day H. pylori eradication course, and the awareness rates were higher than other medical staff (46.92%(236/503), 33.33%(88/264), 32.91%(155/471); 67.20%(338/503), 59.09%(156/264), 53.93%(254/471)), and the differences were statistically significant ( χ2=111.25 and 59.99, both P<0.001). The understanding rates of the sixth national consensus and the guideline in gastroenterologists was 85.33% (192/225), which was higher than that of other medical staff (64.21%(323/503), 66.67%(176/264), 57.96%(273/471)), and the difference was statistically significant ( χ2=85.47, P<0.001). Conclusions:Gastroenterologists from general hospitals in Hainan Province have a better understanding of the sixth national consensus and the guideline than other medical staff. However, there is still a lack of deep understanding of the sixth national consensus and the guideline, and it is necessary to further strengthen the learning and application of the sixth national consensus and the guideline.