基于生物学义教新课标的跨学科项目式学习初探——以“关注生命指标-血氧饱和度”为例

在2022版义务教育生物学新课程标准的指导下,以“关注生命指标-血氧饱和度”为例开展跨学科项目式学习,着力培养学生社会责任感、创新精神和实践能力。

超声显示脂肪肝者血脂、血糖、肝功能等生化指标分析

目的:探讨超声结合血脂、血糖、肝功能等生化指标对脂肪肝的诊断和临床应用价值。方法:对93例患有脂肪肝的住院患者及健康体检者进行超声检查,并结合血脂、血糖、肝功能等生化指标进行分析。结果:本组超声表现脂肪肝者,甘油三酯(TG)、空腹血糖(GLU)及二者合并异常达82.0%。结论:超声作为脂肪肝筛选的重要方式,其结合血脂、血糖、肝功能等生化指标进行分析,更能有效地提供治疗依据。

基于新课标探究唾液淀粉酶对淀粉的消化作用

本文基于新课标“探究唾液淀粉酶对淀粉的消化作用”进行研究,探究淀粉溶液浓度、唾液淀粉酶溶液浓度和水浴温度对淀粉褪色时间的影响。建议使用0.5%淀粉溶液、2.0%唾液淀粉酶溶液,在37℃条件下开展定性、定量实验。对师生基于新课标开展本实验探究活动提供参考。

Advances and Challenges of Exosome Metabolomics in Body Fluids

Exosomes,ubiquitously present in body fluids,serve as non-invasive biomarkers for disease diagnosis,monitoring,and treatment.As intercellular messengers,exosomes encapsulate a rich array of proteins,nucleic acids,and metabolites,although most studies have primarily focused on proteins and RNA.Recently,exosome metabolomics has demonstrated clinical value and potential advantages in disease detection and pathophysiology,despite significant challenges,particularly in exosome isolation and metabolite detection.This review discusses the significant technical challenges in exosome isolation and metabolite detection,highlighting the advancements in these areas that support the clinical application of exosome metabolomics,and illustrates the potential of exosomal metabolites from various body fluids as biomarkers for early disease diagnosis and treatment.

UBE2C as an Immune-Related Biomarker for Breast Cancer:A Study Based on Multiple Databases

Objective To screen the target genes that are associated with survival of breast cancer(BRCA) and explore their prognostic values and immune correlations with BRCA using multiple databases..Methods The microarray expression datasets of BRCA were downloaded from the Gene Expresssion Omnibus database(GEO) and analyzed to obtain differentially expressed genes(DEGs). Hub genes were obtained by constructing and visualizing the protein-protein interaction network of DEGs. The key gene was determined using R language, STRING, and Cytoscape, and the differential expression of the key gene was verified using external datasets The Cancer Genome Atlas(TCGA) and quantitative real-time PCR(q RT-PCR) for BRCA tissues of 37 patients. The prognostic value and immunological correlation of UBE2C in BRCA were explored using R language, TIMER, and Gene Set Enrichment Analysis(GSEA).Results Of 10 hub genes seleceed from 302 DEGS, UBE2C was identified as the gene associated with BRCA survival. The expression of UBE2C was differentially upregulated in BRCA, as verified by TCGA and q RT-PCR. Prognostic analysis revealed that UBE2C served as an independent prognostic factor. High expression of UBE2C was associated with decreased immune infiltration levels of B cells, CD4+ T cells, CD8+ T cells, macrophages, and myeloid dendritic cells in BRCA tissue. The expression of UBE2C in BRCA showed a significant correlation with immune checkpoints genes PDCD1, CD274, and CTLA4 expressions. There was a positive correlation between the expression of UBE2C and the tumor mutational burden and microsatellite instability. GSEA demonstrated that UBE2C expression significantly enriched 786 immune-related gene sets.Conclusions UBE2C expression in BRCA tissues is closely related to the BRCA immune microenvironment and showes predictive values on the survivals and prognosis of BRCA patients and the effecacy of immunotherapy. UBE2C may be an potential immune-related prognostic biomarker for BRCA.

2022年版义务教育生物学课程标准框架逻辑分析

从课程目标、课程内容、课程实施、课程评价4个方面对《义务教育生物学课程标准(2022年版)》的总体编写逻辑进行梳理分析,并从“整体”到“分解”分别对这4个方面的内涵及突出特征进行解读,以回应与总体编写逻辑的关系。从框架入手到分步解读的落地,帮助教师理解新课标“整体”与“分解”的逻辑性。

Integrating proteomics and targeted metabolomics to reveal the material basis of liver-gallbladder damp-heat syndrome in chronic hepatitis B

Objective To elucidate the biological basis of liver-gallbladder damp-heat syndrome(LGDHS)within the framework of traditional Chinese medicine(TCM)as a complementary diagnostic and therapeutic approach in chronic hepatitis B(CHB).Methods CHB patients and healthy volunteers were enrolled from Shuguang Hospital Affili-ated to Shanghai University of Traditional Chinese Medicine between August 21,2018 and December 31,2020.They were divided into three groups:healthy group,LGDHS group,and latent syndrome(LP)group.Proteomic analysis using isobaric tags for relative and absolute quantitation(iTRAQ)was performed to identify differentially expressed proteins(DEPs).Metabolomic profiling via ultra-performance liquid chromatography-tandem mass spec-trometry(UPLC-MS/MS)was applied to serum samples to detect differentially regulated metabolites(DMs).Kyoto Encyclopedia of Genes and Genomes(KEGG)and Gene Ontology(GO)enrichment were employed to explore dysregulated pathways.Principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA)were utilized to visualize group separation and identify key metabolites and proteins contributing to LGDHS differentiation.Receiver operating characteristic(ROC)curve analysis evaluated the diagnostic performance of key biomarkers,while logistic regression models assessed their predictive accuracy.P values were corrected for multiple tests using the Benjamini-Hochberg method to control the false discovery rate(FDR).Validation of potential biomarkers was con-ducted using independent microarray data and real-time quantitative polymerase chain reac-tion(RT-qPCR).Results A total of 150 participants were enrolled,including healthy group(n=45),LGDHS group(n=60),and LP group(n=45).254 DEPs from proteomics data and 72 DMs from metabolomic profiling were identified by PCA and OPLS-DA.DEPs were mainly enriched in immune and complement pathways,while DMs involved in amino acid and energy metabolism.The integrated analysis identified seven key biomarkers:α1-acid glycoprotein(ORM1),asparagine synthetase(ASNS),solute carrier family 27 member 5(SLC27A5),glu-cosidase II alpha subunit(GANAB),hexokinase 2(HK2),5-methyltetrahydrofolate-homocys-teine methyltransferase(MTR),and maltase-glucoamylase(MGAM).Microarray validation confirmed the diagnostic potential of these genes,with area under the curve(AUC)values for ROC analysis ranging from 0.536 to 0.759.Among these,ORM1,ASNS,and SLC27A5 showed significant differential ability in differentiating LGDHS patients(P=0.016,P=0.035,and P<0.001,respectively),with corresponding AUC of 0.749,0.743,and 0.759,respectively.A logis-tic regression model incorporating these three genes demonstrated an AUC of 0.939,indicat-ing a high discriminatory power for LGDHS.RT-qPCR further validated the differential ex-pression of ORM1 and SLC27A5 between LGDHS and LP groups(P=0.011 and P=0.034,re-spectively),with ASNS showing a consistent trend in expression(P=0.928).Conclusion This study integrates multi-omics approaches to uncover the molecular mecha-nisms underlying LGDHS in CHB.The identification of biomarkers ORM1,ASNS,and SLC27A5 offers a solid basis for the objective diagnosis of LGDHS,contributing to the stan-dardization and modernization of TCM diagnostic practices.

Genetic Study on JS399-19 Resistance in Hyphal Fusion of Fusarium graminearum by Using Nitrate Nonutilizing Mutants as Genetic Markers

Twenty-two nitrate nonutilizing （nit） mutants were recovered from five wild-type isolates of Fusarium graminearum and fifty nit mutants were recovered from three JS399-19-resistant mutants of F. graminearum cultured on MMC medium. Some biological properties were compared between nit mutants and their parental isolates. The results showed that there were no significant differences in growth rate, cultural characters or pathogenicity between JS399-19-resistant nit mutants and their parental isolates. But the conidial production and the sexual reproduction ability changed to some extent. There was no cross resistance toward chlorate and JS399-19 in F. graminearum and the resistance could be stable through 20-time subcultures. Therefore, the nit could be used as a genetic marker for studying the genetics of JS399-19 resistance in E graminearum, which was used to study JS399-19 resistance transferability in hyphal fusion. Resistance in JS399-19 could not be transferred by hyphal fusion or could be transferred with low chance between two compatible isolates, which would delay the development of JS399-19 resistance in the field.

Effects of Nitrogen Fertilizer Management on Biological Traits and Physiological Indexes at Seedling Stage and Yield of Directly-sown Rapeseed(Brassica napus L.)

Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed （Brassica napus L.） at the seedling stage and investigate the relationship between these biological traits or physiological indexes at the seedling stage and yield, so as to provide scientific theoretical support for high yield and efficient fertilization management in production of winter rapeseed. Field trials were conducted in Chengdu plain of Sichuan Province under rice-rapeseed rotation system during the period of 2011-2012. The nitrogen application rate trial consisted of five nitrogen levels （0, 90, 180, 270 and 360 kg/hm2） and the nitrogen application time trial included NTl（single application as base fertilized）, NT2 （bottom application ＋one time of topdressing at seedling stage） and NT3 （bottom application＋two times of topdressing at seedling stage） under the same nitrogen rate （225 kg/hm2）. The results indicated that compared with no nitrogen application （NO） treatment, the in- crease of nitrogen fertilizer is beneficial to the increase of biological traits including plant height, green leaf number, leaf area index and dry weight of rapeseed at the seedling stage, the improvement of physiological indexes including total nitrogen content, chlorophyll content and soluble protein content of functional leaves, and the reduction of soluble sugar content. Nitrogen rate was linearly correlated with various biological traits at the seedling stage and physiological indexes including total nitro- gen content, chlorophyll content and soluble sugar content in functional leaves over- a/I, but in parabolic correlation with soluble protein content. Under the same nitrogen rate, NT2 treatment exhibited biological traits remarkably or significantly higher than NT1 treatment and NT3 treatment. The nitrogen application times were linearly cor- related with the physiological indexes of functional leaves at the seedling stage. The various biological traits and physiological index of functional leaves at the seedlings stage were in quadratic function parabolic correlation with seed yield, and the corre- lation was significant （P〈0.05）. Therefore, under the rice-rapeseed rotation system in Chengdu plain, the economic rational nitrogen rate is 180-225 kg/hm2, and the mode of bottom application ＋ one time of topdressing （NT2） is suitable.

The Establishment and Characterization of a Continuous Cell Line of Mouse Cervical Carcinoma

OBJECTIVE To establish a murine uterine cervical cancer cell line and to define its biological characters. METHODS Transplanted tumor tissue was used for in vitro primary culture of U14 cervical carcinoma cells. After 20 passages, we examined its morphology, chromosomes, tumorigenicity and produced a growth curve. CK was detected by immunohistochemistry, the cell cycle determined by flow cytometry and the metastatic potential assessed in 615 and C57BL/c mice. We also transfected the cells with the pEGFP-N1 plasmid. RESULTS A newly established murine cell line was passaged 50 times over a period of 10 months. The cells grow as a partially suspended culture, and are immunohistochemically CK（＋）. The cell line is characterized by a hypotetraploid karyotype, a chromosomal number of 64-68 and a doubling time of 21.8 h. Exponential growth occurs by the third and forth day of culture. Cell cycle analysis showed G1 34%, G2 26%, and 40% in the S phase. The tumorigenicity was 100% upon implantation. No mycoplasma contamination was detected. A monoclonal continuous U14-GFP cell strain which was 100% GFP （＋） was also produced. CONCLUSION We successfully established a new murine cervical U14 carcinoma cell line and an U14-GFP monoclonal strain. These cell lines are ideal for combined in vivo and in vitro tumor research.

生物学:新课程实施中的五个关注点

在落实义务教育生物学课程标准过程中,教师要关注以下五点:以立德树人为根本,以新课标为指导,以发展核心素养为目标,以生物学概念为基础,以情境创设为依托。

Molecular Detection of Healthiness of Bombyx mori

[Objective] The paper was to explore the regularity between heat shock protein expression and the healthiness changes of Bombyx moil materials. [Method] The representative heat shock protein gene Bmhsp24.3 was screened by bioinfor- matic analysis method, and carried out real-time PCR expression analysis. [Result] The target gene Bmhsp24.3 expressed in different B. mori materials, but the expres- sion level in different materials significantly varied. The relative expression level of the gene had different degrees of changes under different rearing conditions. With the increase of rearing temperature, the gene expression was upregulated. The ma- terials with better healthiness had remarkable increase in expression of target gene, while the materials with poorer healthiness had less increase in expression of target gene. The expression difference of target gene Bmhsp24.3 was exactly consistent with the healthiness of breeds. [Conclusion] The healthiness of materials had rela- tionship with expression of target gene Bmhsp24.3. the higher the expression of tar- get gene Bmhsp24.3 was, the better the healthiness of materials was; conversely, the lower the expression of target gene Bmhsp24.3 was, the poorer the healthiness of materials was.

Rab23 is a potential biological target for treating hepatocellular carcinoma

AIM： To elucidate the role of Rab23 in hepatocellular carcinoma （HCC） by assessing the expression of Rab23 in HCC tissue and in HCC cell lines. METHODS： Primary tumors （n = 100） were stained with Rab23 antibodies using immunohistochemistry and in situ hybridization in tissue microarrays. Relationships between gene expression and pathology parameters were analysed. The biological significance of Rab23 in Hep-3B cells was examined by knocking down Rab23 gene expression. We designed a pair of doublestranded RNAs against human rab23 and transfected siRNA into Hep-3B cells. Rab23 expression in these cells was examined using RT-PCR and Western blots. We investigated cell growth by MTT assays and fluorescenceactivated cell sorting. RESULTS： High cytoplasmic and nuclear expression of Rab23 was found in 38 of 71 （53.5%） and in 49 of 68 HCC patients （72%） respectively, which correlated with tumor size. HCC cell lines expressed Rab23. In Hep3B cells, siRNA for Rab23 decreased Rab23 mRNA by 4.5-fold and protein expression by 2-fold. Survival rates at 24 and 48 h for Hep-3B cells tTansfected with siRNA were lower and about 30% Hep-3B cells were apoptotic. Knocking down rab23 suppressed Hep3B cell growth, suggesting that rab23 could play an important role in Hep3B cell growth. CONCLUSION： Rab23 is overexpressed and/or activatedin HCC. Rab23 may be both a HCC predictor and a target for treating HCC.

Urinary nucleosides as biological markers for patients with colorectal cancer

AIM: Fourteen urinary nucleosides, primary degradation products of tRNA, were evaluated to know the potential as biological markers for patients with colorectal cancer. METHODS: The concentrations of 14 kinds of urinary nucleosides from 52 patients with colorectal cancer, 10 patients with intestinal villous adenoma and 60 healthy adults were determined by column switching high performance liquid chromatography method. RESULTS: The mean levels of 12 kinds of urinary nucleosides (except uridine and guanosine) in the patients with colorectal cancer were significantly higher than those in patients with intestinal villous adenoma or the healthy adults. Using the levels of 14 kinds of urinary nucleosides as the data vectors for principal component analysis, 71% (37/52) patients with colorectal cancer were correctly classified from healthy adults, in which the identification rate was much higher than that of CEA method (29%). Only 10% (1/10) of patients with intestinal villous adenoma were indistinguishable from patients with colorectal cancer. The levels of m1G, Pseu and m1A were positively related with tumor size and Duke's stages of colorectal cancer. When monitoring the changes in urinary nucieoside concentrations of patients with colorectal cancer associated with surgery, it was found that the overall correlations with clinical assessment were 84% (27/32) and 91% (10/11) in response group and progressive group, respectively. CONCLUSION: These findings indicate that urinary nucleosides determined by column switching high performance liquid chromatography method may be useful as biological markers for colorectal cancer.

New serological biomarkers of inflammatory bowel disease

Serological biomarkers in inflammatory bowel disease (IBD) are a rapidly expanding list of non-invasive tests for objective assessments of disease activity, early diagnosis, prognosis evaluation and surveillance. This review summarizes both old and new biomarkers in IBD, but focuses on the development and character-ization of new serological biomarkers (identifi ed since 2007). These include fi ve new anti-glycan antibodies, anti-chitobioside IgA (ACCA), anti-laminaribioside IgG (ALCA), anti-manobioside IgG (AMCA), and antibod-ies against chemically synthesized (∑) two major oligomannose epitopes, Man α-1,3 Man α-1,2 Man (∑Man3) and Man α-1,3 Man α-1,2 Man α-1,2 Man (∑Man4). These new biomarkers serve as valuable complementary tools to existing biomarkers not only in differentiating Crohn's disease (CD), ulcerative colitis (UC), normal and other non-IBD gut diseases, but also in predicting disease involvement (ileum vs colon), IBD risk (as subclinical biomarkers), and disease course (risk of complication and surgery). Interestingly, the prevalence of the antiglycan antibodies, including anti-Saccharomyces cerevisiae antibodies (ASCA), ALCA and AMCA, was found to be associated with single nucleotide polymorphisms (SNPs) of IBD susceptible genes such as NOD2/CARD15, NOD1/CARD4, toll-likereceptors (TLR) 2 and 4, and β-defensin-1. Further-more, a gene dosage effect was observed: anti-glycan positivity became more frequent as the number of NOD2/CARD15 SNPS increased. Other new serum/ plasma IBD biomarkers reviewed include ubiquitination factor E4A (UBE4A), CXCL16 (a chemokine), resistin, and apolipoprotein A-IV. This review also discusses the most recent studies in IBD biomarker discovery by the application of new technologies such as proteomics, fourier transform near-infrared spectroscopy, and mul-tiplex enzyme-linked immunosorbent assay (ELISA)'s (with an emphasis on cytokine/chemokine profiling). Finally, the prospects of developing more clinically use-ful novel diagnostic algorithms by incorporating new technologies in serological biomarker profiling and integrating multiple biomarkers with bioinformatics analysis/modeling are also discussed.

How to Analyze the Function of Control Genes in Batches

Functional analysis of control genes is playing an important role in animal development.The research is mainly focused on developing a method of estimating the gene's effect or function in the development of animals.In this article,the gene's expression and control are described by models of quantitative genetics,which include the genetic models about the genes with no interaction and interaction effect.On this basis,a method analyzing the functions of control genes in batches is advanced,the method includes three steps as follows: Firstly,describe the gene's expression and control with multiple regression models in statistic method in different conditions.Secondly,collect the material of gene's polymorphism related to the gene's expression and control.Because,gene's polymorphism or the codominant molecular marker electropherogram in a gene locus present 3 states,and can be expressed with -1,0 and 1 respectively.The author thinks it can be regarded as levels in orthogonal layout.Discard the materials of gene's polymorphism not fitting the orthogonal layout,and use the materials of gene's polymorphism fitting the orthogonal layout as the data to estimate the gene's effects.Thirdly,analyze the gene's effect or function with equations as follows:suppose that a quantitative trait is controlled by N gene loci,in each locus there are two alleles,the alleles' effects are A GM1 ?a GM1 ;A GM2 ? a GM2 ;...;A GMi ?a GMi ;...;A GMN ;a GMN units respectively.When the genotype in a locus is heterozygous A GMi a GMi ,the interaction coefficient of alleles in a locus is K units.If there is no interaction among different gene loci,the author thinks,the gene's effects and gene's type can be estimated by using such equation: P GM =2∑Ni=1(A i-a i+K i)+∑Ni=1(A i-a i)M GMi -∑Ni=1K GMi M GMi 2 If there are interactions among different gene loci,and the effect of the x th gene's state combined with the y th gene's state in the k th gene group is defined as Y xyr ,and let gene group electropherogram states be r (where r∈ ),the author thinks,the gene group's effects can be estimated by the equation: Y xyr = K PCxy0 +K PCxy r+K PCxy' r 2+K PCxy'' 3+K PCxy(3') r 4+K PCxy(4') r 5+K PCxy(5') r 6+K PCxy(6') r 7+K PCxy(7') r 8 If there are interactions among more genes,the analogous method can also be used. In this way,be using the gene's codominent marker materials fitting the orthogonal layout,the gene's expression and control can be researched by the method of multiple regression,the gene's relative effect can be estimated,the overdominant gene's overdominant coefficient can be assessed,the gene's type can be identified,the interaction gene group's relative effect and the interaction gene's relation can be estimated as well,and furthermore,the gene's relation can be expressed in equations.For the sake of understanding the method used in this paper,the rout to prove it is given as well.Finally,the author thinks,this method is very useful to research the gene's function in molecular developmental biology.

The expression of Elf-1 and Ki-67 and their correlations in non-small-cell lung cancer

Objective: Elf-1 is a member of the proto-oncogenes Ets-related transcription factor family and over-expressed in many human tumors, Ki-67 is an important nuclear antigen associated with cell proliferation. This study investigated the expression of Elf-1 and Ki-67 in non-small-cell lung cancer(NSCLC) and studied their correlation with the clinicopathological features. Methods: Tissue microarray from 64 cases lung cancer tissue and 10 cases normal lung tissue was constructed, immunohistochemical method was used to evaluate the protein expressions of Elf-1 and Ki-67, correlations of the expression of Elf-1 and Ki-67 to clinicopathological features of NSCLC were analyzed. Results: Expression of Elf-1 and Ki-67 in NSCLC tissues were significantly higher than in normal lung tissues(P < 0.05), the positive rate of Elf-1 and Ki-67 was 73.44% and 64.06% in NSCLC group, Overexpression of Elf-1 in NSCLC was significantly related to histopathological grading, different clinical staging and the intensity of ELF-1 expression was significantly higher in the group with lymph node metastasis than that without(P < 0.05). Overexpression of Ki-67 was also closely related to tumor differentiation, clinical stages and lymph node metastasis(P < 0.05). In addition positive correlation was found between the expressive intensity of Elf-1 and Ki-67(τ = 0.295, P = 0.018). Conclusion: The high expression and positive correlation of Elf-1 and Ki-67 in NSCLC suggest that they probably play a role in onset and progression of lung cancer, united detecting their expression could be used as an valuable molecular biological index for predicting the malignant behavior and early diagnosis of NSCLC.

Uncertainties in Stock Assessment and the Precautionary Management Suggestions for the Anchovy (Engraulis japonicus) Stock in the Yellow Sea

Anchovy(Engraulis japonicus) is an abundant fish species in the Yellow Sea,and its natural stock is decreasing rapidly in recent years. Based on the stock-recruitment(SR) data from 1987 to 2002 published in Zhao et al.(2003),the criterion BIC(Bayesian Information Criterion) is applied to selecting a suitable model from six normal and lognormal error structured SR statisti-cal models,the age-structured model is used to calculate the biological reference points(BRPs),and the precision of the SR parame-ters and BRPs are calculated using bootstrap method. The results indicate that the anchovy fishery resource in the Yellow Sea is in an over-fished state. The precaution management principle requires that the fishery should be closed immediately.

Advances in the application of quantum dots in tumor markers investigation

Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as ceils and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carders would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability.

Biomechanical characteristics of an anterior cruciate ligament injury in javelin throwing

Purpose： The purpose of this study was to understand the mechanism of an anterior cruciate ligament （ACL） injury in javelin throwing and javelin throwing techniques relevant to this ACL injury. Methods： The patient in this study was an elite female javelin thrower who completed the first three trials and sustained a non-contact ACL injury on her left knee in the fourth trial of javelin throwing during a recent track and field meet. Three-dimensional kinematic data were collected in the injury and non-injury trials. The kinematic data of 52 male and 54 female elite javelin throwers were obtained from a javelin throwing biomechanical database. Results： The patient had greater forward center of mass velocity and less vertical center of mass velocity after the first 25% of the delivery phase in the injury trial compared to non-injury trials. The patient had less left knee flexion angle and angular velocity but similar left knee valgus and internal rotation angles during the first 21% of the delivery phase in the injury trial compared to non-injury trials. The video images showed an obvious tibia anterior translation at the 30% of the delivery phase in the injury trial. The left knee flexion angle and angular velocity at the time of the left foot landing and the maximal left knee flexion angle during the delivery phase were not significantly correlated to the official distance for 52 male and 54 female elite javelin throwers. Conclusion： The ACL injury in this study occurred during the first 30% of the delivery phase, most likely during the first 25% of the delivery phase. A stiff landing of the left leg with a small knee flexion angle was the primary contributor to this injury. Javelin throwers may have a soft left leg landing with a flexed knee, which may help them prevent ACL injuries without compromising performance.