Tranexamic acid is widely used in joint orthopedic surgery.At the same time,it has high safety and few adverse drug reactions.It can effectively improve intraoperative bleeding and promote early functional recovery of patients.This article reviews the mode of administration,safe dose,administration time and adverse drug reactions of tranexamic acid in the perioperative period of joint replacement and arthroscopic surgery,in order to provide reference for the clinical application of tranexamic acid.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective To assess the value of acute gastrointestinal injury(AGI)and intestinal fatty acid-binding protein(I-FABP)in the prognosis of liver cirrhotic patients with sepsis.Methods Clinical data of 84 liver cirrhosis patients with sepsis who were admitted to the intensive care unit(ICU)of a hospital from September 2020 to March 2023 were analyzed retrospectively,and 41 patients with decompensated liver cirrhosis during the same period were selected as the control group.Serum I-FABP level in patients was determined with enzyme-linked immunosorbent assay(ELISA).Scores of the model of end-stage liver disease(MELD)and sequential organ failure assessment(SOFA)were calculated.AGI was evaluated based on medical records.30-day and 90-day survival was observed.Correlation among variables was analyzed by Spearman correlation.Risk factors for death in patients with liver cir-rhosis and sepsis was determined by multivariate Cox regression analysis.The optimal cut-off value was determined by receiver operating characteristic(ROC)curve,and the diagnostic efficacy was compared through the area under the ROC curve(AUC).Results Both AGI grading and I-FABP level in liver cirrhosis patients with sepsis were higher than those in the control group(both P＜0.05).I-FABP level was correlated with procalcitonin(PCT),MELD,and SOFA scores in patients with liver cirrhosis and sepsis(all P＜0.05).AGI grading was positively cor-related with SOFA score(P=0.038).The 30-day and 90-day mortality of patients in the liver cirrhosis with sepsis group were 25.0％(n=21)and 35.7％(n=30),respectively.Multivariate Cox regression analysis showed that baseline I-FABP and SOFA scores were independently correlated with 30-day and 90-day survival,and the I-FABP quartile showed good prognostic differentiation efficacy.ROC curve showed that I-FABP could significantly improve the predictive effect of SOFA score on the prognosis of patients.Conclusion AGI grading and I-FABP level in liver cirrhosis patients with sepsis are elevated significantly.Serum I-FABP is associated with the prognosis of patient and can improve the predictive efficacy of SOFA score for survival.

In recent years, nucleic acid therapy, as a revolutionary therapeutic tool, has shown great potential in the treatment of genetic diseases, infectious diseases and cancer. Lipid nanoparticles (LNPs) are currently the most advanced mRNA delivery carriers, and their emergence is an important reason for the rapid approval and use of COVID-19 mRNA vaccines and the development of mRNA therapy. Currently, mRNA therapeutics using LNP as a carrier have been widely used in protein replacement therapy, vaccines and gene editing. Conventional LNP is composed of four components: ionizable lipids, phospholipids, cholesterol, and polyethylene glycol (PEG) lipids, which can effectively load mRNA to improve the stability of mRNA and promote the delivery of mRNA to the cytoplasm. However, in the face of the complexity and diversity of clinical diseases, the structure, properties and functions of existing LNPs are too homogeneous, and the lack of targeted delivery capability may result in the risk of off-targeting. LNPs are flexibly designed and structurally stable vectors, and the adjustment of the types or proportions of their components can give them additional functions without affecting the ability of LNPs to deliver mRNAs. For example, by replacing and optimizing the basic components of LNP, introducing a fifth component, and modifying its surface, LNP can be made to have more precise targeting ability to reduce the side effects caused by treatment, or be given additional functions to synergistically enhance the efficacy of mRNA therapy to respond to the clinical demand for nucleic acid therapy. It is also possible to further improve the efficiency of LNP delivery of mRNA through machine learning-assisted LNP iteration. This review can provide a reference method for the rational design of engineered lipid nanoparticles delivering mRNA to treat diseases.

The main components and working principle of the negative pressure isolation treatment equipment were described,and the classification and application scopes of the negative pressure isolation treatment equipment from foreign countries and China were reviewed.The structure,key technical parameters and characteristics of different types of negative pressure isolation treatment equipment were analyzed under different conditions.The problems of the negative pressure isolation treatment equipment were analyzed,and it's pointed out it would be enhanced in component simplification,comfort,intelligence and multifunctionality.[Chinese Medical Equipment Journal,2024,45(2):97-104]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective:To explore the effect of heterozygous deletion of histone methyltransferase Kmt2c gene on the hematological system of mice.Methods:CRISPR/Cas9 technology was used to construct mice model of Kmt2c heterozygous deletion(Kmt2c+/-)and the changes of whole blood cell count in mice were continuously monitored by blood routine test.The clonal expansion ability of bone marrow cells was explored by colony formation assay in vitro and the proportion of primitive hematopoietic cells,including long-term hematopoietic stem cell(LT-HSC),short-term hematopoietic stem cell(ST-HSC),and multipotent progenitor cell in mutant mice was analyzed by flow cytometry.Results:Kmt2c+/-mice model was successfully constructed,and the mRNA expression level of Kmt2c was 28％of that of C57BL/6J mice.The colony formation ability of bone marrow cells of Kmt2c+/-mice in vitro increased with the passage times,and the colony number in the fourth generation was significantly higher than that of control group(P＜0.05).The proportions of LT-HSC and ST-HSC in the primitive hematopoietic cell population of Kmt2c+/-mice was 19.6％±3.3％and 28.9％±4.9％,respectively,which showed an increasing trend compared with 16.9％±2.6％and 18.9％±2.5％in control group,but the difference was not statistically significant(P＞0.05).The white blood cell count of Kmt2c+/-mice gradually increased after 12 weeks of monitoring and reached(9.8±1.0)×109/L at the 14th week,which was significantly higher than(7.3±1.4)× 109/L of control group(P＜0.05).Conclusion:The bone marrow cells of Kmt2c+/-mice have potential of clonal expansion.

Objective To explore the common features of Chinese ethnic groups.Methods Eight body indexes of 62 ethnic groups in China were analyzed.Results The cluster analysis showed that 52 males and 59 females ethnic groups were grouped into the mixed group dominated by the northern ethnic group and the mixed group dominated by the southern ethnic group.Eight Han ethnic groups were grouped into each group,but no Han group was aggregated.The result of body index classification showed that the main body types of Chinese male population were long trunk,middle chest,wide shoulder,wide pelvis and middle leg.Middle body,wide chest,wide shoulder,wide pelvis and middle leg were the main body types of Chinese female population.This showed that the characteristics of Chinese ethnic groups had obvious consistency.The consistency of Chinese group features was related to its close origin.It should be said that Han nationality played an important role in the process of communication and integration of various ethnic groups in China.In the history of the Han nationality,there had been many large-scale population migration.The southern movement of the northern ethnic minorities into the northern Han and the southward movement of the northern Han into the south promoted the formation of the Southern Han,which made the southern Han and the northern Han had similar body features,and also promoted the southern ethnic minorities into the southern Han.In addition,the Han nationality who moved into minority areas also gradually integrated into minority areas.Conclusion There are obvious commonalities in Chinese ethnic groups.

Objective To survey and analysis of cephalometric indicators of Wa adults in China.Methods Cephalometric parameters were measured in 1996 cases(858 males and 1138 females)of Wa adults in China,including 927 cases(381 males and 546 females)of the Baraoke ethnic group,564 cases(241 males and 323 females)of the A Wa ethnic group,and 505 cases(236 males and 269 females)of the Wa ethnic group by using sliding caliper and spreading caliper.Seventeen direct cephalofacial parameters and one indirect parameter for each of the three dialect ethnic groups were derived separately and analyzed for age correlations,inter-sex u-tests,and multiple comparisons.Finally,the three dialect ethnic groups were subjected to cluster analysis and principal component analysis with 15 ethnic groups in China.Results Nose breadth,mouth breadth and physiognomic ear length were significantly and positively correlated with age for both sexes in the three Wa dialect ethnic groups,while head breadth and lip height were significantly and negatively correlated with age.Except for the interocular breadth,there were gender differences between males and females in the cephalometric parameters of the three Wa dialect ethnic groups.The cephalofacial features of the Baraoke,A Wa and Wa ethnic groups were different,as evidenced by the fact that males and females of the Baraoke and Wa dialect ethnic group had higher lip height,wider nasal breadth and wider mouth breadth,while males and females of the A Wa ethnic group had lower nasal height.Conclusion The cephalofacial features of the three Wa dialect ethnic groups are close to those of the Khmus and Mang,who have their origins in the ancient Baipu people and are also members of the Mon-Khmer language group of the Austroasiatic linguistic.

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.