BACKGROUND:The age distribution of patients with distal femur fracture is bimodal,being more common in young adults with high-energy injuries and older individuals with low-energy injuries.In cases of complex distal femoral fractures,a single less invasive stabilization system or retrograde femoral nail is insufficient to provide a stable environment for fracture healing and combined fixation is often necessary.OBJECTIVE:A novel combined fixation method(less invasive stabilization system combined with retrograde tibial nail)was developed for the treatment of type A3 distal femur fractures.Using finite element analysis,the bio-mechanical properties of this method were compared with two common combined fixation methods—dual plate(less invasive stabilization system combined with locking compression plate)and nail plate combination(less invasive stabilization system combined with retrograde femoral nail).This study aims to provide a theoretical basis for the selection of clinical internal fixation methods for distal femur fracture.METHODS:CT images of a 23-year-old healthy male volunteer were utilized to reconstruct the femur three-dimensional model using Mimics and Geomagic Studio software.This model was then compared with in vitro finite element analysis data from existing literature to validate the accuracy of the femoral three-dimensional model.The three-dimensional model of type A3 distal femur fractures and internal fixation were then created using Creo 5.0 software.Three kinds of different combined fixation methods(less invasive stabilization system+retrograde tibial nail,less invasive stabilization system+locking compression plate,less invasive stabilization system+retrograde femoral nail)were assembled and subjected to Boolean operation to establish three sets of finite element models.These models were then imported into Abaqus finite element analysis software to assign material properties,apply consistent boundary conditions,and submit calculations under three loads(normal standing,slow walking,and descending stairs).The resulting stress distribution within the internal fixation as well as overall and local deformation of the femur was analyzed.Furthermore,the failure risk and anti-deformation ability of the new combined fixation method(less invasive stabilization system combined with retrograde tibial nail)were evaluated.RESULTS AND CONCLUSION:(1)Although the anti-deformation ability of the less invasive stabilization system combined with retrograde tibial nail was approximately 10％lower than that of the less invasive stabilization system combined with locking compression plate,it was comparable to that of less invasive stabilization system combined with retrograde femoral nail and demonstrated good anti-deformation ability.(2)The stiffness of the femur with all three combined fixation methods remained consistent during gait,while femur displacement increased linearly with load,indicating high stability.(3)The failure risk associated with less invasive stabilization system combined with retrograde tibial nail was lower than that of the other two methods,with a 2.94％reduction in failure risk compared to less invasive stabilization system combined with locking compression plate.(4)This new combined fixation method offers distinct advantages in terms of anti-deformation ability,safety,and effectiveness,laying a theoretical foundation for further clinical application.

Objective: To explore the relationship between sleep characteristics, physical activity patterns, with depressive and anxiety symptoms in college students, so as to provide reference for student mental health promotion. Methods: From September to November 2023, a convenience sampling method was used to select 7 954 college students aged 18-22 years from 9 universities in Shanghai, Hubei, and Jiangxi. Assessments were conducted using the International Physical Activity Questionnaire Short-Form (IPAQ-SF), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder Scale-7 (GAD-7), and Pittsburgh Sleep Quality Index (PSQI) to evaluate physical activity, depressive and anxiety symptoms, and sleep quality, respectively. Logistic regression analysis was employed to explore the impact of sleep characteristics and physical activity patterns on depressive and anxiety symptoms and their comorbidity among college students. Results: The detection rates for depressive symptoms, anxiety symptoms, and comorbid depression and anxiety symptoms were 25.67%, 35.39%, and 23.15%, respectively. Factors such as gender, grade, household registration, parental education level, annual family income, family structure, and dietary habits were all associated with the detection rates of depressive and anxiety symptoms and their comorbidity (χ2=4.41-118.39, P<0.05). Physical activity patterns, sleep duration, sleep quality, and sleepwake characteristics were also associated with the occurrence of depressive and anxiety symptoms and their comorbidity (χ2=9.66-627.70, P<0.05). Logistic regression analysis showed that college students who stayed up late and slept less than 7 had the highest risk of depressive and anxiety symptoms and their comorbidity (OR=1.93, 1.85, 1.88, P<0.05). Compared to regular physical activity patterns, insufficient physical activity patterns were associated with an increased risk of depressive and anxiety symptoms (all OR=1.18, P<0.05). Further stratified analysis results showed that the risk of depression, anxiety and their comorbidity increased in college students who stayed up late and slept less than 7 h, went to bed before midnight and slept less than 7 h, or went to bed before midnight and slept more than 7 h but did not have sufficient physical activity (P<0.05). Conclusions Sleep characteristics and physical activity patterns significantly affect depressive and anxiety symptoms in college students. Universities should strengthen sleep management and implement flexible physical activity interventions to help students establish healthy lifestyles.

BACKGROUND:The age distribution of patients with distal femur fracture is bimodal,being more common in young adults with high-energy injuries and older individuals with low-energy injuries.In cases of complex distal femoral fractures,a single less invasive stabilization system or retrograde femoral nail is insufficient to provide a stable environment for fracture healing and combined fixation is often necessary.OBJECTIVE:A novel combined fixation method(less invasive stabilization system combined with retrograde tibial nail)was developed for the treatment of type A3 distal femur fractures.Using finite element analysis,the bio-mechanical properties of this method were compared with two common combined fixation methods—dual plate(less invasive stabilization system combined with locking compression plate)and nail plate combination(less invasive stabilization system combined with retrograde femoral nail).This study aims to provide a theoretical basis for the selection of clinical internal fixation methods for distal femur fracture.METHODS:CT images of a 23-year-old healthy male volunteer were utilized to reconstruct the femur three-dimensional model using Mimics and Geomagic Studio software.This model was then compared with in vitro finite element analysis data from existing literature to validate the accuracy of the femoral three-dimensional model.The three-dimensional model of type A3 distal femur fractures and internal fixation were then created using Creo 5.0 software.Three kinds of different combined fixation methods(less invasive stabilization system+retrograde tibial nail,less invasive stabilization system+locking compression plate,less invasive stabilization system+retrograde femoral nail)were assembled and subjected to Boolean operation to establish three sets of finite element models.These models were then imported into Abaqus finite element analysis software to assign material properties,apply consistent boundary conditions,and submit calculations under three loads(normal standing,slow walking,and descending stairs).The resulting stress distribution within the internal fixation as well as overall and local deformation of the femur was analyzed.Furthermore,the failure risk and anti-deformation ability of the new combined fixation method(less invasive stabilization system combined with retrograde tibial nail)were evaluated.RESULTS AND CONCLUSION:(1)Although the anti-deformation ability of the less invasive stabilization system combined with retrograde tibial nail was approximately 10％lower than that of the less invasive stabilization system combined with locking compression plate,it was comparable to that of less invasive stabilization system combined with retrograde femoral nail and demonstrated good anti-deformation ability.(2)The stiffness of the femur with all three combined fixation methods remained consistent during gait,while femur displacement increased linearly with load,indicating high stability.(3)The failure risk associated with less invasive stabilization system combined with retrograde tibial nail was lower than that of the other two methods,with a 2.94％reduction in failure risk compared to less invasive stabilization system combined with locking compression plate.(4)This new combined fixation method offers distinct advantages in terms of anti-deformation ability,safety,and effectiveness,laying a theoretical foundation for further clinical application.

Objective: To investigate the association between physical activity frequency and anxiety/depression symptoms among college students in Jiangxi Province, so as to provide a basis for the physical and mental health development of adolescents. Methods: From July to October 2023, 5 761 college students from 11 colleges and universities in Jiangxi Province were selected by convenience sampling to conduct an online questionnaire survey regarding physical activity and mental health. Anxiety symptoms and depressive symptoms were assessed by General Anxiety Disorder Scale-7 and Patient Health Questionnaires-9, respectively. Contingency table was used to analyze the distribution of different anxiety and depression symptoms by physical activity frequency, and ordered Logistic regression was used to analyze the association between physical activity frequency with anxiety and depressive symptoms, and stratified analysis was performed based on gender. Results: The detection rate of anxiety symptoms of college students was 43.6% ( n =2 513), and the detection rate of depression symptoms was 63.9% ( n =3 682). There were significant differences in the detection rate of anxiety and depression symptoms among different gender and physical activity frequency groups ( χ 2=15.98, 106.32; 30.65, 150.88, P <0.05). The detection rates of severe anxiety and depression symptoms of male and female who never exercise were higher (severe anxiety: 6.1% for male and 5.2% for female, severe depression: 8.7% for male and 7.4% for female).The results of ordered Logistic regression analysis showed that compared with college students who never exercised, male college students who were physically active almost every day were negatively correlated with mild anxiety and moderate depression symptoms ( OR=0.53，0.33，P <0.05). In addition, male college students who do physical activity 3-4 times a week were negatively correlated with moderate depressive symptoms ( OR =0.43), while male college students who do physical activity 1-2 times a week were negatively correlated with severe depressive symptoms ( OR =0.21) ( P <0.05). Physical activity was negatively correlated with different degress of anxiety and depression symptoms in female college students (anxiety: OR =0.27-0.74, depression: OR =0.18-0.75, P < 0.05). Conclusions The frequency of physical activity in college students (especially female college students) is negatively correlated with anxiety and depressive symptoms. It is suggested to improve the frequency of physical activity to promote physical and mental health.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objective: To investigate the relationship between health literacy and sports injuries among high school students with athletic specialization, so as to provide theoretical basis for the intervention of sports injury occurrence of sports special students. Methods: A total of 443 high school students with athletic specialization aged 16-18 years old from 21 urban and rural areas in Shangrao City, Ganzhou City and Nanchang City of Jiangxi Province were selected by convenient sampling method from March to April 2023, and the health literacy and sports injury incidence were investigated. The assessment of sports injury was based on the Monitoring Method of Child and Adolescent Injury, and the assessment of health literacy level was conducted using the Interactive Health Literacy Questionnaire of Chinese Adolescents. χ 2 test was used to compare the reported rate of sports injuries among the demographic and sports training groups and the correlation between health literacy and sports injuries. Binary Logistic regression analysis was used to infer the correlation between the health literacy level of high school students with athletic specialization and the occurrence of sports injuries. Results: The prevalence of sports injury was 49.4% in high school students with athletic specialization. Binary Logistic regression analysis showed that the risk of sports injury of high school students with athletic specialization with medium and low level of health literacy was significantly increased compared with high level (medium level: OR = 1.98,95% CI =1.12-3.51; low level: OR =2.08, 95% CI =1.18-3.68), high school students with athletic specialization in low level of health awareness of sports injury risk was higher than other dimensions of health literacy level (middle level: OR =2.77, 95% CI =1.48-5.19; low level: OR =2.01, 95% CI =1.04-3.88)( P <0.05). The results of stratified analysis showed that among male students with athletic specialization and students with track and field, students with moderate/low overall health literacy had a higher risk of sports injuries compared to high level students (male students: low level, OR =2.46, 95% CI =1.15-5.28; track and field: intermediate level, OR =2.17, 95% CI =1.06-4.43, low level, OR =2.09, 95% CI =1.02-4.30; P <0.05). Conclusions There is a correlation between the health literacy level of high school students with athletic specialization and the occurrence of sports injuries. Students health awareness should be improved to reduce the risk of sports injuries.

Objective: To investigate the current status of milk tea consumption and its association with psychological distress among college students, so as to provide theoretial support for promoting the mental health of college students. Methods: From September to November 2023, a convenience sampling method was used to select 15 440 college students aged 17-24 from seven universities in Shanghai, Jiangxi, Hubei, and Shanxi. A self designed questionnaire and the Kessler Psychological Distress Scale were used to assess milk tea consumption and psychological distress, respectively. The Mantel-Haenszel test was employed to analyze the trend of psychological distress at different levels of milk tea consumption. Binary Logistic regression analysis was used to determine the association between milk tea consumption and psychological distress, and the restricted cubic spline method was applied to explore the nonlinear relationship between milk tea consumption and symptoms of psychological distress. Results: The detection rate of psychological distress among college students was 59.6%. Univariate analysis indicated a significant trend association between milk tea consumption frequency ( χ 2 trend =42.33) and milk tea intake level ( χ 2 trend = 5.17 ) with psychological distress ( P <0.05). Binary Logistic regression models showed a positive association between different levels of milk tea consumption frequency and psychological distress [1-3 times (mild to moderate distress, OR =1.20,1.41), 4-5 times (mild to severe distress, OR =2.80,5.44,4.12), and ≥6 times (severe distress, OR =8.04); and milk tea intake level: 1-1 500 mL (severe distress, OR =1.35), >1 500- <3 000 mL (mild to moderate distress, OR =1.21, 1.35), ≥3 000 mL (mild to severe distress, OR =1.33,1.71,1.29)] ( P <0.05 ). The restricted cubic spline model showed a nonlinear association between milk tea intake and the risk of psychological distress ( F = 107.34 , P non linear <0.01, P overall <0.01). Conclusions High frequency and high volume milk tea consumption are associated with an increased risk of psychological distress among college students. Reducing the consumption behavior of college students milk tea is helpful to improve mental health.

Objective:To investigate a brucellosis outbreak caused by contact with unquarantined sheep in Chongqing, and provide reference for prevention and control of brucellosis.Methods:In accordance with the requirements of the "Technical Plan of Brucellosis Prevention and Control Project of Chongqing" and the "Working Specification for Epidemic Disposal of Human Brucellosis" (DB50/T 946-2019), a self-designed brucellosis case questionnaire (version 2021) was used to carry out case investigation and laboratory tests on cases reported by medical institutions, and the data were analyzed descriptively.Results:According to "Working Specification for Epidemic Disposal of Human Brucellosis" (DB50/T 946-2019) in Chongqing, the brucellosis outbreak that occurred in December 2021 was determined to be a cluster outbreak, with a total of two confirmed cases of brucellosis, and a incidence rate of 2/9. The reason of the outbreak was the rearing and slaughtering of unquarantined sheep.Conclusion:We should strengthen the inspection and quarantine of livestock such as cattle and sheep, crack down on informal trade of livestock, and reduce the risk of brucellosis.