Outer membrane vesicles (OMVs) are nanoscale vesicles secreted by Gram-negative bacteria. As a unique bacterial secretion, OMV secretion can help bacteria maintain the outer membrane stability or remove harmful substances. Studies have shown that local separation of outer membrane and peptidoglycan layers led by abnormalities in outer membrane protein function, abnormal structure or excessive accumulation of LPS, and erroneous accumulation of phospholipids in the outer leaflet, which can all lead to bacterial outer membrane protrusion and eventually bud formation of OMVs. Since OMVs are mainly composed of bacterial outer membrane and periplasmic components, the pathogen associated molecular patterns (PAMPs) on their surface can trigger strong immune responses. For example, OMVs can recruit and activate neutrophils, polarize macrophages to secrete large amounts of inflammatory factors. More importantly, OMVs can act as adjuvants to induce dendritic cell (DC) maturation to enhance adaptive immune response in the body. At the same time, OMVs are derived from bacteria, which make it easy to modify. The methods by genetic engineering and others can improve their tumor targeting, give them new functions, or reduce their immunotoxicity, which is conducive to their application in tumor therapy. OMVs not only induce apoptosis or pyroptosis of tumor cells, but also regulate the host immune system, which makes OMVs themselves have a certain killing effect on tumors. In addition, the tendency of neutrophils to inflammatory tumor sites and the formation of neutrophil extracellular traps enable OMVs to target tumor sites, and the suitable size and the characteristic that they are easily taken up by DCs give OMVs a certain lymphatic targeting ability. Therefore, OMVs are often employed as excellent drug or vaccine carriers in tumor therapy. This review mainly discusses the biological mechanism of OMVs, the regulatory effects of OMVs on immune cells, the functional modification strategies of OMVs, and their research progress in tumor therapy.

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 effect of Ginkgo biloba extract(GBE)on depression like behavior in post stroke depression(PSD)model rats,and explore the mechanism of regulating Toll like receptor 4/nuclear factor-κ B(TLR4/NF-κB)pathway to inhibit neuroinflammation.Methods Rats were randomly divided into 6 groups,sham,cerebral ischemia,PSD,paroxetine,low-dose Ginkgo biloba extract(GBE-L)and high-dose Ginkgo biloba extract(GBE-H)groups,10 rats in each group.Except for the sham group,middle cerebral artery occlusion(MCAO)was performed to prepare a left focal cerebral ischemia model.Except for the sham group and cerebral ischemia group,other groups were subjected to chronic unpredictable mild stress(CUMS)to establish PSD rat model for 8 weeks.After 4 weeks of CUMS,the paroxetine group,GBE-L,and GBE-H were treated with paroxetine 5 mg·kg-1,GBE 50 mg·kg-1,and GBE 100 mg·kg-1,respectively.The sham group,cerebral ischemia group,and PSD group were treated with the same volume of 0.9％NaCl and continuously administered by gavage for 28 d.After 4 weeks and 8 weeks of CUMS,the body weight and sugar preference test were measured.Levels of serum tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β)and levels of norepinephrine(NE),serotonin(5-HT),and dopamine(DA)in the cerebral cortex were measured by enzyme-linked immunosorbent assay(ELISA).The mRNA levels of Tlr4,Nfkb1,and nuclear factor κ B-kinase subunit β inhibitory factor(Ikbkb)in the hippocampus of rats were detected by polymerase chain reaction.The protein levels of NF-κB,nuclear factor κB inhibitory protein α(IKBα)and phosphorylation nuclear factor κB inhibitory protein α(p-IKB)in hippocampal tissue were detected by Western blot.Results The body weights of rats in the sham group,cerebral ischemia group,PSD group,paroxetine group,GBE-L group and GBE-H group were(427.10±6.36),(403.10±7.37),(310.10±9.71),(355.00±4.03),(347.90±9.88)and(391.90±5.07)g;sugar preference rate were(93.93±1.78)％,(91.57±1.03)％,(54.72±7.34)％,(88.35±4.36)％,(63.55±12.73)％and(81.04±4.31)％;the levels of NE in the cerebral cortex were(1 951.14±52.86),(1 827.27±23.63),(1 662.12±35.92),(2 033.58±72.28),(1 887.31±33.07)and(2 175.00±42.54)pg·mL-1;the levels of 5-HT in the cerebral cortex were(237.07±8.86),(226.15±10.27),(214.51±3.46),(297.13±5.79),(274.14±7.63)and(285.34±8.72)ng·mL-1;the levels of DA in the cerebral cortex were(1 531.11±47.26),(1 209.89±58.09),(1 143.15±36.31),(1 812.67±51.28),(1 651.56±31.82)and(1 853.33±20.42)pg·mL-1.Compared with the PSD group,GBE significantly increased the body weight of rats(P＜0.01)and increased the preference rate of sugar water in rats,showing the antidepressant like behavioral.GBE significantly reduced the levels of serum TNF-α,IL-1 β(all P＜0.01),increased the levels of NE,5-HT,and DA in the cerebral cortex(all P＜0.01),down regulate the mRNA levels of Tlr4,Nfkb1 and Ikbkb(P＜0.05,P＜0.01),reduced the expression of NF-κB(P＜0.01),and reduced the phosphorylation of IKBα(P＜0.01).Conclusion Ginkgo biloba extract can improve depression-like behavior in PSD model rats,and has antidepressant effect.Its mechanism is related to the inhibition of TLR4/NF-κB pathway,thus reducing neuroinflammation.

Objective To investigate the effect and mechanism of hypericin on osteoporosis(OP)in rats with chronic obstructive pulmonary disease(COPD).Methods COPD combined with OP rat model was established by cigarette combined with bacteria.The rats were randomly divided into control group,model group(COPD combined with OP model was constructed),experimental-L group(50 mg·kg-1 hypericin was given by intragastric administration after constructing COPD combined with OP model),experimental-H group(100 mg·kg-1 hypericin was given intragastric administration after constructing COPD combined with OP model),positive group(subcutaneous injection of 16 U·kg-1 salmon calcitonin after constructing COPD combined with OP model);each group was given 12 rats for 90 days.The lung function of rats was detected by pulmonary function apparatus;bone mineral density(BMD)was detected by micro-computed tomography(CT);serum bone metabolism and inflammatory factors were detected by enzyme-linked immunosorbent assay(ELISA);Western blot assay was used to detect the relevant indicators of the pathway.Results The levels of forced vital capacity(FVC)in control group,model group,experimental-H group and positive group were(10.42±1.40),(4.10±0.60),(6.75±0.37),(4.18±0.33)mL,respectively;BMD levels were(0.31±0.04),(0.12±0.02),(0.28±0.03),(0.29±0.04)g·mm-3,respectively;bone alkaline phosphatase(BALP)levels were(200.04±20.03),(80.80±6.00),(148.16±14.23),(173.97±23.55)U·L1,respectively;interleukin-1β(IL-1β)levels were(122.60±8.70),(695.59±74.84),(422.41±44.86),(527.90±39.36)pg·mL-1,respectively;phosphorylated p38 mitogen-activated protein kinase(p-P38)protein expression levels were 0.99±0.11,0.36±0.05,0.79±0.08,0.36±0.04,respectively.Compared with the control group,the above indexes in the model group had statistical significance(all P＜0.05);the above indexes in experimental-H group were significantly different from those in model group(all P＜0.05).Conclusion Hypericin can inhibit inflammatory response,improve bone metabolism and biomechanics.

In the treatment process of proton radiation therapy,the patient needs to be positioned and immobilized before being moved into the treatment position.In this study,the patient was primarily positioned using the 6R robotic treatment couch as the patient support system(PSS).A simplified three-dimensional model of the treatment room was developed based on the relative motion within the treatment room.The forward and inverse kinematics of the 6R robotic treatment couch were analyzed using an improved Denavit-Hartenberg(D-H)representation.A collision interference model was created based on the actual treatment process.The motion path of the treatment couch was planned and simulated in MATLAB using an improved artificial potential field method for obstacle avoidance.The results indicate that the robotic treatment couch can smoothly navigate around obstacles to reach the target point,satisfying the positioning requirements for proton therapy.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective To develop a biological safety protection third-level(BSL-3)laboratory based on folding-modular shelters to solve the problems of the existing laboratories in space and function expansion,large-scale deployment and low-cost transportation.Methods The BSL-3 laboratory was composed of a folding combined shelter module,a ventilation and purification module,a power supply and distribution module,a monitoring and communication module,a control system module and an equipment module.The folding combined shelter module used a leveling base frame as the foundation and a lightweight panel as the enclosure mechanism,and was divided into an auxiliary area and a protection protected area;the ventilation and purification module was made up of an air supply unit and an air exhaust unit,the air supply unit was integrated with a fresh-air air conditioner and the exhaust unit was equipped with a main fan,a standby fan and a bag in/bag out filter;the control system module adopted a supervision mode of decentralized control and centralized management,which executed communication with the data server as the center and Profinet protocol and MODBUS-TCP.Results The BSL-3 laboratory proved to meet the requirements of relevant standards in internal microenvironment,airflow direction,airtightness,working condition and disinfection effect.Conclusion The BSL-3 laboratory is compatible with large-scale transport and deployment and facilitates reliable and safe experiments for epidemic prevention and control and cross-regional support.[Chinese Medical Equipment Journal,2024,45(3):41-46]

The NiFe2O4-graphene oxide nanocomposite modified with polyethylenimine(GO@PEI-NiFe2O4)was prepared to purify and enrich phosphopeptides from biosamples.The Ni2+and Fe3+ions on its surface could coordinate with phosphate groups and then selectively adsorb phosphopeptides.PEI was conducive to the above combination due to its high hydrophilicity.The material showed good magnetic response properties and could be rapidly separated from samples with the aid of magnet.With tryptic digest of β-casein as sample,the enrichment property of the material to phosphopeptides was studied,which was compared with the results of GO@NiFe2O4,revealing the adsorption mechanism of GO@PEI-NiFe2O4.The static and dynamic binding properties of GO@PEI-NiFe2O4 were investigated using pTyr as a representative phosphopeptide,and the adsorption capacity was 36.2 μg/mg.The results showed that the material could remove the interference of nonphosphopeptides and effectively enrich phosphopeptides in complex matrix.After enrichment by GO@PEI-NiFe2O4,1535 phosphopeptides were identified from the tryptic digest of rat liver by mass spectrum and the enrichment effect of GO@PEI-NiFe2O4 greatly outperformed commercial Fe3+-IMAC kits.This work provided an efficient material for the enrichment of phosphopeptides,showing potential applications in phosphoproteomics research.

An analytical method based on ultra high performance liquid chromatography-high resolution tandem mass spectrometry(UHPLC-HRMS/MS)and high performance liquid chromatography-triple quadrupole mass spectrometry(HPLC-TQ MS)was established to reveal the characteristics of various sulfur mustard analogs with different active thiol molecules in CWC Schedule 1.A.04.Firstly,the toxic agents were prepared by micro-directed synthesis,and then the differences of the reactivity and abundance of formed adducts between different sulfur mustards and glutathione(GSH),cysteine(Cys)and N-acetylcysteine(NAC)in incubation solution,plasma and cell were investigated,respectively.The results indicated that all target sulfur mustards could react with three kinds of thiol molecules.The content of Cys and sulfur mustard adducts in plasma was higher than that of GSH and sulfur mustard adducts,while NAC and sulfur mustard adducts might have fewer types of adducts due to low content or poor mass spectrometry response.Additionally,the content of GSH and sulfur mustard adducts in exposed cells was higher than that of Cys,which should be due to the significant difference in the content of thiol molecules in plasma and cells.

Objective To construct the demand model of four types of medical resources including beds in hospi-tal,beds in intensive care unit(ICU),ventilators and medical human resources during the major infectious disease epidemic events,simulate and analyze the treatment of infectious diseases when different medical resources are in short supply.Methods Based on the susceptible-exposed-infectious-recovered(SEIR)model,considering the infec-tivity of infected persons,the susceptibility of the population and the immunity of convalescents,the characteristics of asymptomatic COVID-19 patients and different clinical types,the"COVID-19 infection-hospitalization model"was constructed.By collecting and setting the parameters of disease transmission,clinical course and medical re-source shortage scenarios,an analysis model of allocation and supply of urban medical resources during infectious di-sease epidemic events was initially formed based on Anylogic platform,the supply and demand of medical resources during infectious disease events in different scenarios were analyzed.Results In the non-intervention scenario,the peak time of bed demand was on the 107th day,and the peak value was 160.92 beds per thousand people;the peak time of ventilator demand was on the 122nd day,and the peak value was 5.61 units per thousand people;the peak time of ICU bed demand was on the 117th day,and the peak value was 12.78 beds per thousand people;the peak time of the demand for medical human resources was on the 109th day,and the peak value was 151.12 persons per thousand persons.The simulation results suggested that there were some differences in the impact of different medi-cal resources on the outcome of medical treatment.Conclusion This study constructs an analytical tool for the allo-cation and supply of urban medical resources under the epidemic events of infectious diseases,and the results of mul-tiple simulation experiments suggest that bed resources and medical human resources play more important roles in the outcome of medical treatment.