ObjectiveThis study aims to investigate the regulatory effects of microcapsules with different matrix stiffness on the survival, proliferation, adhesion, and osteogenic differentiation of mesenchymal stem cells (MSCs), to further explore the relationship between matrix stiffness and MSCs osteogenic behavior, and to evaluate the in vivo histological responses and osteogenic-related protein expression of the microcapsules using an animal subcutaneous implantation model. MethodsIn this study, three-dimensional carbon nanofiber (CNF)/sodium alginate (SA) microcapsules with different matrix stiffness were constructed. By adjusting the CNF content, three groups of microcapsules with stiffness values of 27.05, 35.90, and 52.40 kPa were prepared, and their physicochemical properties, including morphology, mechanical properties, particle size, chemical structure, and degradation properties, were characterized. The effects of these microcapsules with different stiffness on the survival, adhesion, and osteogenic differentiation of MSCs were evaluated. Live/dead staining was used to observe cell survival and distribution in the microcapsules, while alkaline phosphatase (ALP) activity and the expression of osteopontin (OPN) and osteocalcin (OCN) were examined to assess osteogenic differentiation. Immunofluorescence staining was further performed to observe the expression of Yes-associated protein (YAP) and integrin β1 under different stiffness conditions. In addition, a rat subcutaneous implantation model was used to evaluate the in vivo tissue compatibility of the microcapsules. Histological staining and immunohistochemical analysis were carried out to examine local tissue responses and the expression of osteogenic-related proteins. ResultsThe results showed that all three groups of microcapsules exhibited regular and uniform morphology and similar particle size, and all groups showed good degradability. Except for the differences in mechanical properties, no obvious differences were found in the other physicochemical properties among the three groups. Live/dead staining indicated that all groups of microcapsules had good cytocompatibility. MSCs in the low-stiffness group were mostly round, whereas cells in the medium- and high-stiffness groups showed more obvious spreading. Higher matrix stiffness was more favorable for MSC adhesion, growth, and survival. ALP staining and quantitative analysis showed that ALP activity increased significantly with increasing matrix stiffness. The expression of the osteogenic-related proteins OPN and OCN also increased with increasing stiffness, and the high-stiffness group showed the strongest positive signals. Immunofluorescence results further indicated that YAP and integrin β1 fluorescence signals tended to increase in MSCs with increasing matrix stiffness, suggesting that matrix stiffness may influence MSC osteogenic differentiation through stiffness-related cell adhesion and mechanotransduction. In vivo experiments showed that all three groups of microcapsules exhibited good histocompatibility after subcutaneous implantation, although different degrees of degradation and local tissue response were observed. Immunohistochemical analysis showed that the expression levels of OPN and OCN increased with increasing matrix stiffness, and the high-stiffness group exhibited higher expression of these osteogenic-related proteins. ConclusionCNF endows SA microcapsules with tunable matrix stiffness. While maintaining good biocompatibility, the high-stiffness microenvironment can effectively promote the adhesion and osteogenic differentiation of MSCs, accompanied by increased ALP activity and enhanced OPN and OCN expression. The increased YAP and integrin β1 fluorescence signals in the high-stiffness group further indicate that matrix stiffness is closely related to cellular mechanical responses. These findings provide a three-dimensional cell carrier with potential application value for MSC delivery and bone tissue regeneration based on mechanical microenvironment regulation.

ObjectivePeripheral nerve injury is a common clinical condition that can impair the regulatory function of target organs, leading to functional disability; severe injuries may even result in lifelong disability. Therefore, how to effectively promote the morphological and functional reconstruction of injured peripheral nerves has become a critical scientific issue that urgently needs to be addressed. This study biomimicked the highly oriented structure and electrophysiological properties of peripheral nerves and investigated the feasibility and effectiveness of combining electrical stimulation (ES) with oriented conductive substrates for the repair of injured peripheral nerves at the cellular level. MethodsPolydimethylsiloxane (PDMS) substrates with oriented microgroove structures of varying widths (0, 5, 10, and 20 μm) were fabricated using silicon wafers with micropatterned grooves as templates. Graphene-based conductive patterned substrates (GCPSs) with oriented microgrooves were then constructed via soft lithography and designated as GCPS 0, GCPS 5, GCPS 10, and GCPS 20 according to the groove width. The GCPSs were prepared from collagen/polycaprolactone (PCL) matrices containing 1.0 wt% graphene, and their morphology, wettability, and conductivity were characterized. Mesenchymal stem cells (MSCs) viability, proliferation, adhesion, and orientation on the substrates were evaluated before ES treatment. Then, ES at a frequency of 2 Hz and field strengths of 10, 20, or 50 mV/cm were applied to the cells for 10 min daily, over 3 or 7 consecutive days. Neural differentiation was assessed by morphological observation, immunofluorescence staining, and analysis of neural lineage-related markers. ResultsThe oriented microgroove PDMS substrates supported long-term MSCs growth, guided cells to align along the groove direction, and promoted a morphological transition toward neural-like cells, exhibiting the capacity to induce MSCs differentiation toward the neural lineage. Microgroove structures effectively guided the alignment of MSCs and promoted the development of a more elongated, neural-like morphology, with the most pronounced morphological changes observed on grooves of 10 and 20 μm in width. Meanwhile, the incorporation of graphene endowed the GCPSs with favorable electrical conductivity, though the groove width did not significantly affect the conductive performance. The GCPSs showed good cytocompatibility with MSCs, and cell proliferation on these substrates exhibited a time-dependent pattern, with no significant effect observed from groove width. The inductive effect of ES combined with GCPSs on MSCs differentiation toward specific neural lineages was co-regulated by ES intensity (0, 10, 20, and 50 mV/cm) and microgroove width. ES at 10 mV/cm and 20 mV/cm promotes MSCs differentiation toward neurons on microgrooved substrates of various widths (5, 10, and 20 μm); under the same ES intensities, microgrooves with widths of 5 μm and 10 μm are more favorable for MSCs differentiation toward glial cells/SCs. Notably, low-intensity ES (10 or 20 mV/cm) combined with GCPS 10 significantly enhanced the neural differentiation of MSCs. Neurotrophic factor secretion levels by MSCs cultured on various GCPS substrates after 3 d of ES application was further detected. There were no significant differences in nerve growth factor‑β (NGF‑β) and brain-derived neurotrophic factor (BDNF) concentrations among the GCPS 5, GCPS 10, and GCPS 20 substrates, and these levels were not affected by variations in ES intensity. Under ES at 10 mV/cm, the glial cell line-derived neurotrophic factor (GDNF) concentration in each GCPS substrate was higher than that in the corresponding non-ES group on the same substrate. However, as ES intensity increased, the GDNF concentration decreased to varying degrees. ConclusionThis study demonstrates that the combined strategy of “oriented topographical structure+ES” can effectively promote the neural differentiation of MSCs and holds promise for accelerating the repair process of peripheral nerve injuries.

Objective To develop and evaluate a nucleic acid amplification test for spectinomycin-resistant Neisseria gonorrhoeae(N.gonorrhoeae).Methods N.gonorrhoeae-specific primers NG1/NG2 and primers specific to the N.gonorrhoeae rpsE gene mutation(80_82 delTTA)were designed.Genomic nucleic acids of spectinomycin-sensitive and resistant N.gonorrhoeae,Escherichia coli,Pseudomonas aeruginosa,and Salmonella typhi were used as templates to be amplified by PCR and quantitative real-time PCR(qPCR).The sensitivity and specificity of the method were evaluated accordingly.Results The NG1/NG2 primers could effectively amplify specific fragments of N.gonorrhoeae,yielding negative results for the nucleic acid amplification test of the other types of bacteria tested.E64/E175R and E-87/E95R could effectively differentiate the wild type and mutant(80_82 delTTA)rpsE genes.In PCR reactions,the minimum limits of NG1/NG2,E64/E175R,and E87/E95R for the target genes were 414.8 copies,414.8 copies,and 4.1 copies/μL,respectively,while those for qPCR reactions were 41.5,41.5,and 4.1×10-2 copies/μL,respectively.Conclusion A nucleic acid amplification test for spectinomycin-resistant N.gonorrhoeae with high specificity and sensitivity was successfully established in this study,which is expected to provide support for the rapid diagnosis of N.gonorrhoeae infection and treatment decision-making in clinical settings.

Objective To investigate the role of a novel rpsE gene mutation in mediating high-level spectinomycin resistance in Neisseria gonorrhoeae and to evaluate its effect on the biological fitness of the bacteria.Methods Spectinomycin-containing medium was used to screen for Neisseria gonorrhoeae strains with spontaneous mutations that conferred spectinomycin resistance.Minimum inhibitory concentrations(MIC)were determined,and the rpsE gene was sequenced.Changes in the growth rates of spectinomycin-resistant strain were assessed using the drop plate method and growth curves.Additionally,in vitro competition experiments were conducted with spectinomycin at different concentrations to assess changes in the biological fitness of the spectinomycin-resistant strain.Results A Neisseria gonorrhoeae strain with high-level spectinomycin resistance mediated by a novel rpsE gene mutation(88_90delGTT)was successfully identified and designated NG-SPTR.Compare with the wild-type strain,the NG-SPTR exhibited reduced growth rate(optical density[OD]comparison,P<0.05).In addition,in vitro competition experiments showed a competitive index(CI)<1 in gonococcal base liquid(GCBL)without or with low-concentration spectinomycin(≤16 μg/mL).In the GCBL with 32 μg/mL spectinomycin,the CI value gradually increased from<1 before 18 h to>1 after 18 h.The mutant strain showed CI>1 in GCBL with spectinomycin concentrations≥64 μg/mL.Conclusion The rpsE gene mutation(88_90delGTT)mediates high-level spectinomycin resistance in Neisseria gonorrhoeae,and imposes a fitness cost on the bacteria.The biological fitness of the mutant strain is influenced by the concentration of spectinomycin.

Objective:To summarize the experience and effect of extracorporeal cardiopulmonary resuscitation (ECPR) in acute myocardial infarction (AMI) with in-hospital cardiac arrest (IHCA).Methods:The data of 70 patients with AMI-IHCA-ECPR in extracorporeal life support center of the first affiliated hospital of Nanjing medical university from January 2017 to December 2024 were retrospectively analyzed. The patients were grouped by Survival/death at 90 days, with/without combined intra-aortic balloon pump (IABP). Age, sex, Charlson comorbidity index, initial rhythm, Gensini score, ECPR initial blood gas pH and lactate value, no-flow time, time from cardiac arrest to extracorporeal membrane oxygenation (ECMO) initiation (CA-Pump On time), ECMO treatment time, 90-day survival rate were analyzed.Results:Among the 70 patients with AMI-IHCA-ECPR, 22 (31.4%) patients survived at 90 days, of whom 19 (86.4%) patients had good neurological outcomes. About 50% of AMI-IHCA-ECPR patients had severe multi-vessel coronary artery lesions, and there was no significant difference in survival outcomes among different vascular lesions. In the IABP group, the success rate of ECMO withdrawal was low, the duration of ECMO treatment was long, and the combination of IABP did not reduce the mortality. Compared with the death group, the 90-day survival group had a lower Gensini score, a higher ECPR initial blood gas pH and a lower lactic acid value.Conclusions:AMI-IHCA-ECPR combined with IABP did not show significant survival benefits, and about 50% of patients had severe lesions of multiple coronary arteries. It is difficult to evaluate the prognosis based on a single offender vessel. It is recommended to evaluate the outcome of patients by quantification of the severity of coronary artery lesions by Gensini score.

[Purpose]To analyze the screening results of urban cancer early diagnosis and treat-ment program in Shaanxi Province from 2021 to 2022.[Methods]The risk assessment and clini-cal screening data of five high incidence malignant tumors(female breast cancer,lung cancer,upper gastrointestinal cancer,liver cancer and colorectal cancer)in the urban cancer early diag-nosis and treatment program in Shaanxi Province were collected and analyzed.The high-risk rate,screening compliance rate,and positive detection rate of the above 5 types of malignant tumors were calculated.[Results]A total of 17 921 urban residents in Shaanxi Province completed the cancer risk survey from 2021 to 2022(44.12％were males and 55.88％were females),9 270 were identified as high-risk(51.7％):34.2％for breast cancer,24.2％for lung cancer,20.7％for upper gastrointestinal cancer,7.5％for liver cancer,and 29.8％for colorectal cancer.Among 18 145 person-times of high-risk,6 357 person-times underwent clinical screening,with an overall com-pliance rate of 35.0％.The participating number and compliance rate of individual cancer screening were 1 451 person-times(42.3％)for female breast cancer,2 064 person-times(47.7％)for lung cancer,1 125 person-times(30.4％)for upper gastrointestinal cancer,468 person-times(35.0％)for liver cancer,and 1 249 person-times(23.4％)for colorectal cancer.The detected positive cases and the detection rate were 142 cases(9.8％)for frmale breast cancer,373 cases(18.1％)for lung cancer,13 cases(1.2％)for upper gastrointestinal cancer,8 cases(1.7％)for liver cancer,and 68 cases(5.4％)for colorectal cancer.[Conclusion]The screening results of early diagnosis and treatment project for urban cancer in Shaanxi Province shows a relative higher risk rate and lower compliance rate with significant differences among various types of cancer.

AIM To optimize the extraction process for total polyphenols from Conioselinum vaginatu(Spreng.)Thell.,make component analysis,and evaluate their anti-oxidant,hypoglycemic activities.METHODS The effects of ultrasound,enzymatic hydrolysis,acid hydrolysis,alcohol extraction and hydrolysis processes on the extraction quantity of total polyphenols were investigated,respectively.With extraction temperature,extraction time,ethanol concetration and liquid-solid ratio as influencing factors,extraction quantity of total polyphenols as an evaluation index,the extraction process was optimized by response surface method.HPLC was adopted in the identification of polyphenolic composition and determination of their contents.Subsequently,total polyphenols' scavenging capacities on DPPH,ABTS,OH free radicals,total reducing power and inhibitory capacity on α-glucosidase were determined.RESULTS The highest extraction quantity of total polyphenols was observable when extraction process was employed.The optimal conditions were determined to be 62 ℃ for extraction temperature,54 min for extraction time,69％for ethanol concentration,and 50∶1 for liquid-solid ratio,the extraction quantity of total polyphenols was(9.51±0.2)mg GAE/g.Seven constituents existed in C.vaginatu,among which ferulic acid demonstrated the highest content,followed by that of myricetin,while D-tryptophan content was the lowest.At the concentration of 7.61 mg/L,total polyphenols displayed the scavenging rates on DPPH,ABTS,OH free radicals of 80.70％,85.97％,28.60％,total reducing power of 0.22,and inhibition rate on α-glucosidase of 77.23％,respectively.CONCLUSION This stable and reliable method can be used for the extraction of total polyphenols from C.vaginatum with strong anti-oxidant,hypoglycemic activities.

Aim To explore the mechanism of the syn-ergistic effect of the ferroptosis inducer erastin com-bined with shikonin in promoting ferroptosis in human hypertrophic scar fibroblasts(HSFBs).Methods Hypertrophic scar tissues provided by the General Hos-pital of Ningxia Medical University were collected,and HSFBs were extracted.HSFBs were identified by HE staining and immunofluorescence.The inhibitory rates of Era and SHK on HSFBs at different concentrations were detected by CCK-8 assay,and the IC50 value was calculated.CompuSyn software was used to calculate the co-use index(CI).Control group,Erastin(Era)group,shikonin(SHK)group and Era+SHK group were set up,and the number and morphological chan-ges of cells were observed after 24 hours of interven-tion.The ability of cell migration and invasion was de-tected by scratch test and Transwell test.The changes of malondialdehyde(MDA),total iron ion and reactive oxygen species(ROS)were detected by corresponding biochemical kits.The expressions of collagen I,α-SMA and GOT1,SLC7A11,GPX4 and FTH1 were detected by Western blot.Results The IC50 value of Era and SHK of primary HSFBs was 2.22 μmol·L-1 and 3.94μmol·L-1 respectively,which was used as the single drug concentration for subsequent experiments.The CompuSyn software was employed to calculate the CI value when the two drugs were used in combination,and the concentrations corresponding to CI=0.39597(Era:1.2 μmol·L-1+SHK:1.5 μmol·L-1)were selected as subsequent combination concentrations(Because when CI was equal to 0.395 97,the concen-tration of each drug was lower than the concentration of single drug,and the inhibition rate of combined drug was greater than 50％).Compared with the monother-apy group,the number of HSFBs in the SHK+Era group was significantly reduced,cell membrane showed breakage and vesiculation,cell wrinkling became smal-ler,and cytoplasm was concentrated.The migration and invasion ability of HSFBs in the SHK+Era group were obviously weakened(P＜0.05),and the expres-sion of fibrosis-related proteins collagen Ⅰ and α-SMA was reduced(P＜0.05);the contents of MDA,total i-ron ions,and ROS in HSFBs of the SHK+Era group increased(P＜0.05),and the protein expression lev-els of SLC7A11,GOT1,GPX4,and FTH1 further de-creased(P＜0.05).Conclusions Erastin in combi-nation with shikonin can synergistically inhibit the pro-liferation,migration and fibrosis levels of HSFBs.The mechanism may be that erastin enhances the inhibition of shikotin on GOT1,increases the levels of cellular i-ron ions,ROS,and lipid peroxides,thereby promoting ferroptosis in HSFBs.

Risks of food safety induced by small molecule drug residues in animal food and environment have become an increasing public concern,so it is necessary to develop highly sensitive and easy-to-operate techniques to detect small molecules.Herein,a metasurface plasma resonance(MetaSPR)sensor chip coupled with gold nanoparticles(AuNPs)was developed for detection of enrofloxacin(ENR)based on competitive immunoassay.The detection range of the sensor for ENR was 0.025-3.2 ng/mL,and the detection limit(3σ)was 20 pg/mL.The biosensor showed excellent performance including high selectivity,good stability,ease to operate and high throughput,etc.The developed method was applied to detection of ENR residues in real samples,with recoveies of 96.0% -105.0%.The proposed sensing strategy provided new technique reference for detection of other small molecules in the field of residue analysis in food safety and environment monitoring.

Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.