Objective To develop a predictive model for postoperative mortality risk in patients with acute aortic dissection(AAD)using the Extreme Gradient Boosting(XGBoost)algorithm combined with Shapley Additive Explanation(SHAP),and to establish a prediction website to serve as a diagnostic and therapeutic support platform for clinicians and patients.Methods A retrospective cohort study design was adopted.Data from 782 AAD patients who underwent surgical treatment at the Fourth Hospital of Hebei Medical University from January 2013 to December 2023 were collected,including basic information and initial serum biomarker test results.Patients were randomly divided into training and test sets at a 7:3 ratio.An external validation set consisting of 313 AAD patients admitted to the Second Hospital of Hebei Medical University from January 2020 to December 2023 was also established for further model validation.Variables were screened using LASSO regression,and an XGBoost machine learning model was constructed and interpreted using SHAP.The predictive performance of the model was evaluated using receiver operating characteristic(ROC)curve analysis.Using the Shiny package,the XGBoost model was deployed to shinyapps.io to create a prediction website for postoperative mortality risk in AAD patients.One patient was selected by simple random sampling from the test set and the external validation set respectively for the prediction example on the Shiny webpage.Results The XGBoost model demonstrated high predictive performance for postoperative mortality in AAD patients,with area under the ROC curve(AUC)values of 0.928(95%CI 0.901-0.956)in the training set,0.919(95%CI 0.891-0.949)in the test set,and 0.941(95%CI 0.915-0.967)in the external validation set.SHAP values indicated the following order of variable importance in the model(from highest to lowest):"lactate dehydrogenase""blood chlorine""multiple organ injury""carbon dioxide combining power""prothrombin time""α-hydroxybutyric acid""creatine kinase isoenzyme""Stanford classification""combined use of bedside blood purification""gender""acute kidney injury""gastrointestinal bleeding""brain injury"and"shock".A risk prediction website for adverse postoperative outcomes in AAD patients was developed using XGBoost-SHAP method(https://dun-dunxiaolu.shinyapps.io/document/)and validated with examples.One randomly selected patient from each of the test and external validation sets was applied:the predicted mortality risk value for patient 1(who died postoperatively)was 0.9539,and that for patient 2(who survived postoperatively)was 0.0206.Conclusions The XGBoost-SHAP model demonstrates high accuracy in predicting postoperative mortality risk for AAD patients.The online prediction tool established based on this model enhances the identification efficiency of high-risk postoperative mortality patients.

Objective To investigate the association of digit ratio with single nucleotide polymorphism(SNP)at three loci(rs17576,rs3918249,rs9509)of matrix metallopeptidase 9(MMP-9)gene.Methods A total of 804 Ningxia Han youths(399 males and 405 females)were used as the study subjects.A digital camera was used to take frontal photographs of the hands,and image analysis software was used to mark the anatomical points and measure the lengths of each finger of both hands(2D,3D,4D,5D);Multiplexed PCR was used to detect the three polymorphic sites of the MMP-9 gene,SPSS 25.0 and R Studio software were used for data analysis and plotting.Results The 2D/3D(P＜0.05)and 2D/4D(left,P＜0.01,right,P＜0.05)of both hands,2D/5D(P＜0.01),3D/5D,4D/5D(P＜0.05)of the right hand,and 3D/4D(P＜0.05)of the left hand in female youths of Ningxia Han were significantly higher than those in males,Differences in genotypes and allele frequencies at all 3 loci of the MMP-9 gene were not statistically significant between genders(P＞0.05).Right hand 2D/4D was significantly associated with genotypes at the rs17576 and rs3918249 loci in male youths(P＜0.05).Conclusion MMP-9 gene SNPs(rs17576 and rs3918249)may be associated with the formation of 2D/4D of Ningxia Han male youths.

Trauma is an important cause of death in young- and middle-aged people. Trauma is comprehensive and includes many surgical specialties, and the surgical techniques of these specialties have long been mature. To reduce the mortality and disability rate of trauma patients, it is necessary to improve trauma management. Trauma has attracted attention in China and trauma treatment and care developed rapidly in recent years. To decrease traumatic mortality and disability rates, our team is committed to building an efficient trauma system in Shaanxi province and has successfully developed a trauma limb salvage map to address the high rates of amputation and disability in patients with limb injuries. This article elaborates on the construction experience of a trauma limb salvage map and its application details in Shaanxi province of China.
Humans ; China ; Limb Salvage/methods* ; Wounds and Injuries/surgery* ; Male ; Extremities/injuries* ; Adult ; Amputation, Surgical ; Middle Aged ; Female

This paper aims to study the effect of Ziziphi Spinosae Semen extracts on chronic unpredictable mild stress(CUMS)-induced depression-like and insomnia behavior models of mice. The CUMS-induced depression-like and insomnia behavior model of mice was established by CUMS treatment for three weeks. The mice were randomly divided into control group, model group, positive drug diazepam group(2 mg·kg~(-1)), as well as low-dose group(1.95 g·kg~(-1)), medium-dose group(3.9 g·kg~(-1)), and high-dose group(7.8 g·kg~(-1)) of Ziziphi Spinosae Semen extracts, with 18 mice in each group. On the 15th day of modeling, the drug was administered intragastrically once a day for one week. Then, the pentobarbital sodium cooperative righting experiment, open field experiment, and elevated plus maze experiment were carried out, respectively. The contents of neurotransmitters 5-hydroxytryptamine(5-HT) and 5-hydroxyindoleacetic acid(5-HIAA) in serum and thalamus of mice, as well as the levels of corticotropin releasing hormone(CRH), adrenocorticotropic hormone(ACTH), and corticosterone(CORT) in serum, were determined by enzyme-linked immunosorbent assay(ELISA). The neuron damage in the hippocampus of mice was observed by hematoxylin-eosin(HE) staining and Nissl staining. Western blot was used to detect the expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), monoamine oxidase A(MAOA), five prime repressors under dual repression binding protein 1(Freud1), synaptic plasticity-related proteins [cellular gene FOS(C-FOS), postsynaptic density protein 95(PSD95), synapsin 1(SYN1), and activity-regulated cytoskeleton-associated gene(ARC)], blood-brain barrier(BBB) permeability-related proteins [zonula occludens 1(ZO-1), occludin, and claudin 1], inflammatory factors [NOD-, LRR-and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein(ASC), gasdermin D(GSDMD), caspase-3, and caspase-8], and antioxidant factors [nuclear factor erythroid 2-related factor 2(NRF2) and heme oxygenase 1(HO1)] in thalamic tissue of mice. The results indicated that compared with that in the model group, the sleep latency was significantly shortened, and the sleep duration was significantly prolonged in each dose group of Ziziphi Spinosae Semen extracts. The number of visits to the central area of the open field and the distance and time of visits were significantly increased in each dose group of Ziziphi Spinosae Semen extracts. In addition, the proportion of distance and time of entering the open arm area of the elevated plus maze was significantly increased in each dose group of Ziziphi Spinosae Semen extracts. The contents of 5-HT and 5-HIAA in serum and thalamus of mice increased to varying degrees in each dose group of Ziziphi Spinosae Semen extracts; the contents of CRH, ACTH, and CORT in serum of mice were significantly decreased. The protein expression of TPH2 was significantly increased. The protein expression of MAOA, SERT, and Freud1 was significantly decreased. Ziziphi Spinosae Semen extracts could also significantly reduce the protein expression of C-FOS but significantly increase the protein expression of PSD95, ARC, and SYN1. They could reduce the pathological damage of the hippocampus in mice and significantly increase the protein expression of ZO-1, occluding, and claudin 1. The protein expression of NLRP3, GSDMD, ASC, caspase-3, and caspase-8 in the thalamic tissue of mice was significantly decreased, and the protein expression of HO1 and NRF2 was significantly increased. In conclusion, Ziziphi Spinosae Semen extracts could effectively improve sleep disorders and depression-like behaviors in CUMS-induced model mice, which may be related to regulating the 5-HT anabolism process and hypothalamic-pituitary-adrenal(HPA) axis-related hormone levels, reducing pathological damage in the hippocampus, improving synaptic plasticity, repairing BBB integrity, and alleviating inflammatory response and oxidative stress damage.
Animals ; Ziziphus/chemistry* ; Mice ; Male ; Depression/psychology* ; Drugs, Chinese Herbal/administration & dosage* ; Sleep Initiation and Maintenance Disorders/psychology* ; Stress, Psychological/complications* ; Behavior, Animal/drug effects* ; Humans ; Disease Models, Animal

Objective:To investigate the clinical value of laparoscopic evaluation of anato-mical position of inferior mesenteric artery (IMA), inferior mesenteric vein (IMV) and left colic artery (LCA).Methods:The prospective one-arm study was conducted. The clinical data of 229 pati-ents who underwent laparoscopic left hemicolectomy for left colon or laparoscopic radical resection of rectal cancer in The Second Affiliated Hospital of Air Force Medical University from December 2022 to December 2023 were selected. The distance between the origin point of IMA and the origin point of the first branch (L1) as well as the distance from the origin point of LCA root to the junction of LCA and IMV (L2) were measured during the operation. IMA classification, the location relation-ship of LCA and IMV junction were recorded. Observation indicators: (1) situations of enrolled patients; (2) difference analysis between L1, L2 and clinical features; (3) distribution characteristics of the location relationship between LCA and IMV in different types of IMA. Mann-Whitney U test was used for comparison of measurement data with skewed distribution between groups, Kruskal-Wallis H test was used for comparison between multiple groups, and Dunn-Bonferroni test was used for pairwise comparison. Comparison of count data between groups was performed by chi-square test. Pearson or Spearman correlation analysis was conducted for correlation of continuous variables. Results:(1) Situations of enrolled patients. A total of 229 eligible patients were screened out, including 146 males and 83 females, aged 64(range, 55-71)years. The height of 229 patients was 168(range, 160-172)cm, the weight was 65.0(55.5,71.5)kg, the body surface area was (1.68±0.17)m 2, the tumor maximum diameter was 3.0(2.5,4.0)cm. The total number of lymph nodes dissected was 19(17,21), and the number of No.253 lymph node dissected was 4(3,5). The L1 was 3.50(1.20,8.00)cm, and the L2 was 2.20(0.50,7.30)cm. There were 58, 31, 32, 71, 22, 90, 26 and 212 patients with smoking, alcohol drinking, diabetes, hypertension, coronary heart disease, neoadjuvant chemo-therapy, neoadjuvant radiotherapy and preservation of the LCA, respectively. Among 229 patients, cases with BMI <18.5 kg/m 2, 18.5-23.9 kg/m 2 and >23.9 kg/m 2 were 11, 133 and 85, respectively. There were 153 cases in pathological stage Ⅰ-Ⅱ and 76 cases in stage Ⅲ. There were 168 cases of Dixon operation, 6 cases of Miles operation and 55 cases of sigmoid colon resection. There were 135 cases of IMA type 1, 44 cases of IMA type 2, 23 cases of IMA type 3, 2 cases of IMA type 4, and 25 cases of IMA type unable to judge. (2) Difference analysis between L1, L2 and clinical features.Correlation analysis showed negative correlation between the height, body surface area and L1 ( r=-0.17, -0.15, P<0.05). The L1 was 3.20(2.68,4.00)cm for male patients and 3.60(3.00,4.20)cm for female patients, respectively, showing a significant difference between the two groups ( Z=-2.37, P<0.05). The L1 of patients with IMA type 1, 2, and 3 was 3.20(2.80,4.00)cm, 3.85(3.00,4.48)cm, and 3.20(2.50,4.30)cm, respectively, showing a significant difference among them ( H=7.54, P<0.05). Further pairwise com-parison showed that there was a significant difference in L1 between patients with IMA type 2 and those with IMA type 1 ( P<0.05). The L2 of smokers and non-smokers were 2.50(1.95,3.20)cm and 2.20(1.60,2.80)cm, respectively, showing a significant difference between the two groups ( Z=-2.24, P<0.05). (3)Distribution characteristics of the location relationship between LCA and IMV in different types of IMA. There was no significant difference in LCA distribution between the anterior and posterior positions of IMV among the three IMA types (type 1, 2, 3) ( χ2=1.63, P>0.05). Conclusions:Patients with greater height have larger body surface area and shorter L1. L1 is significantly longer in female patients than in male patients. L1 is significantly longer in patients with IMA type 2 than in those with type 1. L2 is significantly longer in smokers than in non-smokers. There was no significant difference in the distribution location between LCA and IMV among patients of IMA type 1, 2 and 3.

Objective:To investigate the clinical value of laparoscopic evaluation of anato-mical position of inferior mesenteric artery (IMA), inferior mesenteric vein (IMV) and left colic artery (LCA).Methods:The prospective one-arm study was conducted. The clinical data of 229 pati-ents who underwent laparoscopic left hemicolectomy for left colon or laparoscopic radical resection of rectal cancer in The Second Affiliated Hospital of Air Force Medical University from December 2022 to December 2023 were selected. The distance between the origin point of IMA and the origin point of the first branch (L1) as well as the distance from the origin point of LCA root to the junction of LCA and IMV (L2) were measured during the operation. IMA classification, the location relation-ship of LCA and IMV junction were recorded. Observation indicators: (1) situations of enrolled patients; (2) difference analysis between L1, L2 and clinical features; (3) distribution characteristics of the location relationship between LCA and IMV in different types of IMA. Mann-Whitney U test was used for comparison of measurement data with skewed distribution between groups, Kruskal-Wallis H test was used for comparison between multiple groups, and Dunn-Bonferroni test was used for pairwise comparison. Comparison of count data between groups was performed by chi-square test. Pearson or Spearman correlation analysis was conducted for correlation of continuous variables. Results:(1) Situations of enrolled patients. A total of 229 eligible patients were screened out, including 146 males and 83 females, aged 64(range, 55-71)years. The height of 229 patients was 168(range, 160-172)cm, the weight was 65.0(55.5,71.5)kg, the body surface area was (1.68±0.17)m 2, the tumor maximum diameter was 3.0(2.5,4.0)cm. The total number of lymph nodes dissected was 19(17,21), and the number of No.253 lymph node dissected was 4(3,5). The L1 was 3.50(1.20,8.00)cm, and the L2 was 2.20(0.50,7.30)cm. There were 58, 31, 32, 71, 22, 90, 26 and 212 patients with smoking, alcohol drinking, diabetes, hypertension, coronary heart disease, neoadjuvant chemo-therapy, neoadjuvant radiotherapy and preservation of the LCA, respectively. Among 229 patients, cases with BMI <18.5 kg/m 2, 18.5-23.9 kg/m 2 and >23.9 kg/m 2 were 11, 133 and 85, respectively. There were 153 cases in pathological stage Ⅰ-Ⅱ and 76 cases in stage Ⅲ. There were 168 cases of Dixon operation, 6 cases of Miles operation and 55 cases of sigmoid colon resection. There were 135 cases of IMA type 1, 44 cases of IMA type 2, 23 cases of IMA type 3, 2 cases of IMA type 4, and 25 cases of IMA type unable to judge. (2) Difference analysis between L1, L2 and clinical features.Correlation analysis showed negative correlation between the height, body surface area and L1 ( r=-0.17, -0.15, P<0.05). The L1 was 3.20(2.68,4.00)cm for male patients and 3.60(3.00,4.20)cm for female patients, respectively, showing a significant difference between the two groups ( Z=-2.37, P<0.05). The L1 of patients with IMA type 1, 2, and 3 was 3.20(2.80,4.00)cm, 3.85(3.00,4.48)cm, and 3.20(2.50,4.30)cm, respectively, showing a significant difference among them ( H=7.54, P<0.05). Further pairwise com-parison showed that there was a significant difference in L1 between patients with IMA type 2 and those with IMA type 1 ( P<0.05). The L2 of smokers and non-smokers were 2.50(1.95,3.20)cm and 2.20(1.60,2.80)cm, respectively, showing a significant difference between the two groups ( Z=-2.24, P<0.05). (3)Distribution characteristics of the location relationship between LCA and IMV in different types of IMA. There was no significant difference in LCA distribution between the anterior and posterior positions of IMV among the three IMA types (type 1, 2, 3) ( χ2=1.63, P>0.05). Conclusions:Patients with greater height have larger body surface area and shorter L1. L1 is significantly longer in female patients than in male patients. L1 is significantly longer in patients with IMA type 2 than in those with type 1. L2 is significantly longer in smokers than in non-smokers. There was no significant difference in the distribution location between LCA and IMV among patients of IMA type 1, 2 and 3.

The CRISPR/Cas system consists of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (Cas). The system forms an adaptive immune system in archaea and bacteria. The inherent defense mechanism enables these microorganisms to protect themselves against the invasion of foreign genetic material. The system functions of immune response including three main stages: adaptation, expression/maturation, and interference, each stage needs specific Cas proteins encoded by Cas gene located near the CRISPR sequences, along with other auxiliary proteins. In 2015, Zhang et al. reportedCas12a (Cpf1) as a member of the Class II type V CRISPR/Cas12a system, which possesses endonuclease activity. This finding holds great promise for its application in the field of biotechnology. In 2018, Doudna’s team first applied the CRISPR/Cas12a system for detecting HPV nucleic acid. The system comprises the following essential components in vitro detection: Cas12a, the crRNA sequence complementary to the target DNA, the PAM sequence, and the ssDNA reporter. Cas12a possesses a typical RuvC domain, displaying a canonical bilobed architecture that consists of a recognition (REC) lobe and a nuclease (NUC) lobe. The REC lobe contains the REC1 and REC2 domains, and the NUC lobe includes RuvC, PAM-interacting (PI), Wedge (WED), and bridge helix (BH) domains. The mature crRNA for Cas12a has a length of 42-44 nt, consists of repeat sequence (19/20 nt) and spacer sequence (23-25 nt). The crRNA spacer sequence has been found to require a length of 18 nt to achieve complete cleavage activity in vitro. Additionally, mutation in the bases of crRNA can indeed affect the activity of Cas12a. The PAM sequence plays a critical role in the recognition and degradation of DNA by the CRISPR/Cas system, enabling the system to distinguish between self and non-self genomic materials. Cas12a can effectively target the spacer sequence downstream of a T-rich PAM sequence at the 5' end. LbCas12a and AsCas12a both recognize the PAM sequences of 5'-TTTN-3', while FnCas12a recognizes the PAM sequences of 5'-TTN-3'. All of these PAM sequences are located upstream on the non-template strand (NTS) at the 5' end. Cas12a (Cpf1), guided by the crRNA, binds to the target DNA by recognizing the PAM sequence. It exhibits the ability to induce arbitrary cleavage of ssDNA within the system while cleaving the target ssDNA or dsDNA. According to this feature, an array of nucleic acid detection methods has been developed for tumor detection and infection diagnostics, such as the DETECTR (RPA-CRISPR/Cas12a method) and HOLMES (PCR-CRISPR/Cas12a method) in 2018. Then, in 2019, Cas12aVDet (one-step detection method), where Cas12a protein was immobilized on the upper wall of the reaction tube. This not only prevented contamination from opening the tube but also reduced the detection reaction time. In 2021, the dWS-CRISPR (digital warm-start CRISPR) was developed as a one-pot detection method. It serves as an accurate approach for quantitatively detectingSARS-CoV-2 in clinical specimens. With the innovation of scientific technology, the high-sensitivity signal transduction technology has also been integrated with the CRISPR/Cas12a system, enabling direct detection of nucleic acids, and eliminating the need for nucleic acid amplification steps. Here, we elaborated the detection principles of CRISPR/Cas12a in in vitro detection. We discussed the different stages leading to the catalytic pathway of target DNA, and the practical applications of Cas12a in nucleic acid detection. These findings revealed a target interference mechanism that originates from the binding of Cas12a-guided RNA complex to complementary DNA sequences within PAM-dependent (dsDNA) regions. The crRNA-DNA binding activates Cas12a, enabling site-specific dsDNA cleavage and non-specific ssDNA trans-cleavage. The release of Cas12a ssDNase activity provides a novel approach to enhance the sensitivity and specificity of molecular diagnostic applications. Before these CRISPR/Cas12a-based nucleic acid detection methods can be introduced into clinical use, substantial work is still required to ensure the accuracy of diagnosis. Nevertheless, we believe that these innovative detection tools based on CRISPR/Cas will revolutionize future diagnostic technologies, particularly offering significant assistance in pathogen infection diagnosis for developing countries with relatively poor healthcare conditions and high prevalence of infectious diseases.

Objective To assess the screening efficacy of a novel esophageal cell collector and esophageal exfoliated cell cytology examination for esophageal cancer and investigate risk factors associated with cytological examination results in the Han and Mongolian ethnic groups.Methods ①A total of 1196 high-risk individuals with esophageal cancer were selected for treatment at the Second Affiliated Hospital of Baotou Medical College.Esophageal cells were collected,and endoscopic examination and mucosal biopsy of the esophagus were performed.The pathological examination of the digestive tract endoscopic biopsy tissue was used as the gold standard to verify the diagnostic efficacy of cytological examination.① In this study,9256 Han and 572 Mongolian individuals who participated in esophageal cancer screening in the Baotou area were selected as the research subjects.General information,dietary habits,lifestyle habits,and other information of the subjects were collected through a questionnaire survey.Esophageal cells were collected using a new type of esophageal cell collector,and logistic regression analysis was used to identify the risk factors for positive cytology in Han and Mongolian populations.Results ① The novel esophageal cell collector and esophageal exfoliated cell cytology examination demonstrated excellent screening capabilities for esophageal cancer,with sensitivity(92.86％),specificity(99.58％),positive predictive value(PPV)of 72.22％,negative predictive value(NPV)of 99.92％,positive likelihood ratio(PLR)of 221.10,negative likelihood ratio(NLR)of 0.07,Youden index of 0.92,and an area under the ROC curve of 0.961(0.923-1.0).The optimal cutoff value was 2.50,yielding a sensitivity of 92.90％and specificity of 88.20％.②The cytological positivity rate among the Mongolian population(2.27％)was higher than that among the Han population(1.12％).The proportion of alcohol drinkers,those with a preference for hot and spicy foods,and those consuming pickled foods was higher in the Mongolian population than in the Han population.Logistic regression analysis revealed risk factors for the Han population:gender(OR=0.381,95％CI:0.256-0.568),age(OR=1.091,95％CI:1.067-1.116),alcohol consumption(OR=1.693,95％CI:1.150-2.492),and smoking(OR=2.127,95％CI:1.439-3.143).Risk factors for the Mongolian population were gender(OR=0.174,95％CI:0.047-0.638),age(OR=1.124,95％CI:1.052-1.200),and alcohol consumption(OR=3.945,95％CI:1.074-14.489).Conclusion ①The novel type of esophageal cell collector-esophageal exfoliative cytology examination has good screening efficacy for esophageal cancer.② Gender,age,alcohol consumption,and hot eating habits are the main risk factors for positive cytological diagnosis in the Mongolian population,while gender,age,alcohol consumption,and smoking are the main risk factors for positive cytological diagnosis in the Han population.

Objective To investigate the association between the index finger and ring finger length ratio (2D ∶ 4D) and of four loci (rs6461992‚ rs6968828‚ rs7801581‚ rs17427875) polymorphism of homeobox (HOX) A11 gene among Ningxia college students. Methods Digit camera was used to collect frontal hand photos of 667 Han college students (348 males and 319 females) from Ningxia province; Image analysis software was used to mark the anatomical points and measure finger lengths of the index and ring fingers of both hands; multiplex PCR was used to detect each locus polymorphisms of HOXA11 gene; statistical software was used to compare and analyze the differences and associations of 2D ∶4D and gene polymorphisms between different genders. Results Among Ningxia Han college students‚ both left hand and right hand 2D ∶ 4D were significantly higher in females than those of in males (all P< 0. 05)‚ and there were no significant sex differences in right-left hand 2D ∶4D; the genotypes and allele frequencies of rs7801581 locus of HOXA11 gene differed significantly between genders (all P < 0. 05)‚ and none of the other locus polymorphisms showed any significant sex differences; only female left hand 2D ∶4D was significantly associated with rs6461992 locus genotype in the relationship between 2D ∶4D and HOXA11 polymorphisms (P<0. 05). Conclusion There were significant sex differences in 2D ∶ 4D among Han college students in Ningxia‚ and the rs6461992 locus polymorphism of HOXA11 gene may be associated with the formation of 2D ∶4D in females.

Objective To investigate the association of 13 single nucleotide polymorphism(SNP)sites in 6 phalange-bone development related genes[fibroblast growth factor receptor 2(FGFR2),indian hedgehog signaling molecule(IHH),Msh homeobox 1(MSX1),Runx family transcription factor 2(RUNX2),SRY-box transcription factor 9(SOX9),Wnt family member 5A(WNT5A)]with human index-ring finger length ratio(2D∶4D).Methods Digital cameras were used to take frontal photographs of the hands of 731 college students(358 males and 373 females)in Ningxia,and image analysis software was used to mark anatomical points and measure finger lengths of index(2th)and ring(4th);genotyping of 13 SNP sites(rs1047057,rs755793,rs41258305,rs3731881,rs3100776,rs12532,rs3821949,rs45585135,rs3749863,rs1042667,rs12601701,rs1829556,rs3732750)for 6 genes by multiplex PCR;One-Way ANOVA or independent sample t-test indirectly assessed the association between 2D∶4D and 13 SNP sites.Results Both left and right hand 2D∶4D were significantly higher in females than males in Ningxia college students(all P<0.01);no statistically significant differences in genotype and allele frequencies of the 13 SNP sites among different sexes(all P>0.05);among different sexes,male left hand 2D∶4D was significantly associated with the genotype of SOX9 gene rs12601701 site(P<0.05)and right hand 2D∶4D was significantly associated with the genotype of WNT5A gene rs1829556 site(P<0.05);the female right hand 2D∶4D was significantly associated with the MSX1 gene rs12532(P<0.01)and rs3821949(P<0.05)sites genotypes.Conclusion SOX9(rs12601701),WNT5A(rs1829556)and MSX1(rs12532 and rs3821949)gene polymorphisms may be associated with the formation of 2D∶4D in Ningxia population.