Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

From an aqueous extract of the Angelica sinensis root head (guitou), nine pairs of lignanoid enantiomers [(+)-/(-)-1-(+)-/(-)-9], including three pairs of new structures [(+)-/(-)-1-(+)-/(-)-3] and two pairs of chiral separated enantiomers for the first time [(+)-/(-)-4 and (+)-/(-)-5], were isolated and chirally separated by column chromatography over different types of resin, normal and reversed phase silica gels, together with HPLC techniques using reversed phase and chiral columns. Their structures were determined by spectroscopic data analysis, theoretic calculation of electronic circular dichroism (ECD) spectra, and single-crystal X-ray diffraction. The chiral separated new enantiomers named (+)-/(-)-angelignanins Q-T [(+)-/(-)-1-(+)-/(-)-4] and (+)-/(-)-daphneresinol [(+)-/(-)-5], respectively.

Objective To observe the cage subsidence after oblique lateral interbody fusion(OLIF)for lumbar spondylo-sis,summarize the characteristics of the cage subsidence,analyze causes,and propose preventive measures.Methods The data of 144 patients of lumbar spine lesions admitted to our hospital from October 2015 to December 2018 were retrospectively ana-lyzed.There were 43 males and 101 females,and the age ranged from 20 to 81 years old,with an average of(60.90±10.06)years old.Disease types:17 patients of lumbar intervertebral disc degenerative disease,12 patients of giant lumbar disc hernia-tion,5 patients of discogenic low back pain,33 patients of lumbar spinal stenosis,26 patients of lumbar degenerative spondy-lolisthesis,28 patients of lumbar spondylolisthesis with spondylolisthesis,11 patients of adjacent vertebral disease after lumbar internal fixation,7 patients of primary spondylitis in the inflammatory outcome stage,and 5 patients of lumbar degenerative scoliosis.Preoperative dual-energy X-ray bone mineral density examination showed 57 patients of osteopenia or osteoporosis,and 87 patients of normal bone density.The number of fusion segments:124 patients of single-segment,11 patients of two-seg-ment,8 patients of three-segment,four-segment 1 patient.There were 40 patients treated by stand-alone OLIF,and 104 patients by OLIF combined with posterior pedicle screw.Observed the occurrence of fusion cage settlement after operation,conducted monofactor analysis on possible risk factors,and observed the influence of fusion cage settlement on clinical results.Results All operations were successfully completed,the median operation time was 99 min,and the median intraoperative blood loss was 106 ml.Intraoperative endplate injury occurred in 30 patients and vertebral fracture occurred in 5 patients.The mean follow-up was(14.57±7.14)months from 6 to 30 months.During the follow-up,except for the patients of primary lumbar interstitial in-flammation and some patients of lumbar spondylolisthesis with spondylolisthesis,the others all had different degrees of cage subsidence.Cage subsidence classification:119 patients were normal subsidence,and 25 patients were abnormal subsidence(23 patients were grade Ⅰ,and 2 patients were grade Ⅱ).There was no loosening or rupture of the pedicle screw system.The height of the intervertebral space recovered from the preoperative average(9.48±1.84)mm to the postoperative average(12.65±2.03)mm,and the average(10.51±1.81)mm at the last follow-up.There were statistical differences between postop-erative and preoperative,and between the last follow-up and postoperative.The interbody fusion rate was 94.4％.The low back pain VAS decreased from the preoperative average(6.55±2.2 9)to the last follow-up(1.40±0.82),and there was statistically significant different.The leg pain VAS decreased from the preoperative average(4.72±1.49)to the final follow-up(0.60± 0.03),and the difference was statistically significant(t=9.13,P＜0.000 1).The ODI index recovered from the preoperative av-erage(38.50±6.98)％to the latest follow-up(11.30±3.27)％,and there was statistically significant different.The complication rate was 31.3％(45/144),and the reoperation rate was 9.72％(14/144).Among them,8 patients were reoperated due to fusion cage subsidence or displacement,accounting for 57.14％(8/14)of reoperation.The fusion cage subsidence in this group had obvious characteristics.The monofactor analysis showed that the number of abnormal subsidence patients in the osteopenia or osteoporosis group,Stand-alone OLIF group,2 or more segments fusion group,and endplate injury group was higher than that in the normal bone mass group,OLIF combined with pedicle screw fixation group,single segment fusion group,and no endplate injury group,and the comparison had statistical differences.Conclusion Cage subsidence is a common phenomenon after 0-LIF surgery.Preoperative osteopenia or osteoporosis,Stand-alone OLIF,2 or more segments of fusion and intraoperative end-plate injury may be important factors for postoperative fusion cage subsidence.Although there is no significant correlation be-tween the degree of cage subsidence and clinical symptoms,there is a risk of cage migration,and prevention needs to be strengthened to reduce serious complications caused by fusion of cage subsidence,including reoperation.

Objective To explore the analgesic effect of different doses of dezocine combined with ropivacaine for thoracic paravertebral block(TPVB)on patients undergoing thoracoscopic radical resection of lung cancer and the influence on hemodynamics and immune function of patients.Methods Patients with lung cancer who underwent thoracoscopic radical resection were divided into low-dose group and high-dose group according to random number table method.Both groups of patients were given total intravenous anesthesia to complete the surgery.At 15 min before general anesthesia induction,the low-dose group was given TPBV with 0.1 mg·kg-1 dezocine+0.375％ropivacaine for a total of 20 mL,and the high-dose group was given TPBV with 0.15 mg·kg-1 dezocine+0.375％ropivacaine for a total of 20 mL.Comparisons were performed on both groups in terms of analgesic effect,hemodynamic parameters,immune function and occurrence of adverse drug reactions.Results There were 48 cases in low-dose group and 46 cases in high-dose group.In low-dose group,the heart rate values before TPVB,before skin incision,at 5 min after sectioning and at the end of surgery were(78.52±6.54),(70.79±7.07),(74.48±6.68)and(76.69±7.29)beat·min-1,the mean arterial pressure values were(93.16±5.72),(86.38±7.51),(92.15±6.36)and(91.14±6.13)mmHg.In high-dose group,the heart rate values at the above time points were(79.36±7.11),(71.68±6.49),(74.76±7.06)and(76.57±6.52)beat·min-1;the mean arterial pressure values were(93.89±7.18),(85.27±7.41),(90.34±6.52)and(92.43±6.34)mmHg,there were no statistical differences between the two groups(all P＞0.05).The resting state scores at 2,6 and 12 h after surgery were(1.38±0.19),(1.54±0.21)and(1.72±0.16)points,the pain scores at motion state were(1.88±0.15),(2.36±0.37)and(3.26±0.38)points in low-dose group;in high-dose group,the resting state scores were(1.32±0.17),(1.58±0.22)and(1.81±0.18)points,the pain scores at motion state were(1.81±0.13),(2.11±0.31)and(3.03±0.36)points,respectively,there were no statistical differences between the two groups(all P＞0.05).The number of analgesic pump compressions at 24 h after surgery and the number of cases with analgesic remedy were(5.12±1.26)times and 15 cases in low-dose group and were(4.74±1.03)times and 10 cases in high-dose group,with no statistical differences between the groups(all P＞0.05).The percentages of CD3+cells in low-dose group at the end of surgery and at 12 h and 24 h after surgery were(68.51±6.76)％,(54.22±5.43)％and(51.47±6.58)％,the percentages of CD4+cells were(40.29±5.02)％,(34.94±4.79)％and(30.48±5.11)％,CD4+/CD8+ratios were 1.54±0.34,1.36±0.28 and 1.16±0.23;the percentages of CD3+cells in high-dose group were(67.92±7.11)％,(56.58±6.36)％and(54.47±6.89)％,percentages of CD4+cells were(41.33±5.75)％,(35.86±5.21)％and(32.27±4.78)％,the CD4+/CD8+were 1.53±0.35,1.40±0.30 and 1.22±0.26,all with no significant difference(all P＞0.05).The incidence of postoperative adverse drug reactions in high-dose group and low-dose group were 32.61％and 14.58％,with significant difference(P＜0.05).Conclusion When TPVB regimen of dezocine combined with ropivacaine is used in thoracoscopic radical resection of lung cancer,the analgesic effect of low-dose dezocine is comparable to that of high-dose dezocine,with lower risk of adverse drug reactions.

A portable multi-wavelength spectral detector was developed for on-site,rapid and accurate detection of organic pollutants in surface water using ultraviolet light-emitting diodes(UV-LEDs)and the corresponding spectral detection method was built.By measuring the fluorescence spectrum and absorption light intensity and combining with the multi-wavelength spectral correlation calculation method to analyze the target,the developed detector was able to qualitatively and quantitatively detect organic pollutants that responded in the UV-light range of 260-370 nm.The proposed detector was used to detect polycyclic aromatic hydrocarbons(PAHs)and Rhodamine B.The linear ranges of anthracene and Rhodamine B in absorption mode were 10-100 and 8.5-100 mg/L,respectively.In fluorescence mode,the linear ranges for anthracene and Rhodamine B were 0.006-50 and 0.02-0.781 mg/L,correspondingly.The absorption/fluorescence concurrent mode could extend the detection ranges of anthracene and Rhodamine B to 0.006-100 and 0.02-100 mg/L,respectively.The recoveries of PAHs in surface water ranged from 97.4%to 105.1%for anthracene and 84.5%to 91.2%for anthracene,naphthalene,and pyrene in absorption and fluorescence modes,respectively.The method was accurate in both modes.The mixtures containing PAHs were identified by the proposed method under the optimized multi-wavelength spectral correlation calculation.The results demonstrated that the method could achieve a similarity of 75%or more when identifying two different concentrations of solutions containing a single or a mixture of targets within the linear concentration range of the targets.However,the similarity dropped to less than 25%when identifying two solutions of different substances.The proposed method had excellent recognition abilityof targets.The proposed detector and method combined fluorescence and absorption spectroscopy,which could expand the application of spectroscopy in the in situ rapid identification and detection of pollutants such as PAHs in surface water.

Magnetic beads (MB),composed of magnetic nanoparticles and biocompatible materials including cellulose,chitosan,silica and polystyrene,are ideal platforms for specific detection of cancer cells,virus and nucleic acids when loaded with antibodies,fluorescent and conjugation molecules. With the ease of separations using magnets,magnetic particles show tremendous advantages over other platforms and thus arising potentials in circulating tumor cell (CTC),virus (such as SARS-CoV-2) antibody and antigen detections,and nucleic acid extractions and purifications. In addition,when combined with microfluidic devices,magnetic particles can be used to develop detection platforms with high throughputs,as well as portable and point-of-care apparatus. In accompany with their huge potentials in all kinds of biomedical and clinical scenarios,magnetic particles based medical devices have been commercialized such as antigen test kits that have been commonly used during the pandemic. In this review,the progress in detailed antibody conjugation practice used in each application scenario based on MB platform was summarized and the commercialization of analytical devices combined with microfluidics and others was discussed.

Objective:To observe the intervention effect of aerobic Baduanjin exercise combined with treadmill train-ing on chronic obstructive pulmonary disease(COPD)complicated chronic heart failure(CHF).Methods:A total of 180 COPD+CHF patients who were treated in Mianyang Central Hospital from January 2019 to June 2021 were selected.They were equally divided into control group(basic treatment and intervention)and experimental group(received aerobic Baduanjin exercise combined with treadmill training based on control group)by random number table method,both groups were intervened for 12 weeks.COPD assessment test(CAT)score,left ventricular ejec-tion fraction(LVEF),left ventricular end systolic volume(LVESV),left ventricular end diastolic volume(LV-EDV),scores of modified medical research council(mMRC)and Minnesota living with heart failure questionnaire(MLHFQ)were compared between two groups before,4,8 and 12 weeks after intervention.Results:During 12-week intervention,CAT score,LVESV,LVEDV,scores of mMRC and MLHFQ showed a gradual decreasing trend,while LVEF showed a gradual increasing trend in two groups,P＜0.05 or＜0.01.Compared with control group after 12-week intervention,there were significant reductions in CAT score[(17.47±3.96)points vs.(13.36±3.42)points],LVEDV[(139.44±7.12)ml vs.(131.74±6.47)ml],LVESV[(81.84±8.54)ml vs.(74.29±9.18)ml],scores of mMRC[(1.67±0.47)points vs.(1.42±0.50)points],each dimension and total score of MLHFQ[(40.07±6.86)points vs.(32.54±6.61)points],and significant rise in LVEF[(41.29±4.76)％vs.(44.56±4.42)％]in experimental group(P＜0.001 all).Conclusion:Aerobic Baduanjin exercise combined with treadmill training based on basic treatment can significantly improve cardiopulmonary function,re-lieve dyspnea and improve quality of life in COPD+CHF patients,which is worth promoting.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]