Objective To study the root canal morphology of permanent mandibular anterior teeth and explore its correlation with the occurrence of three-rooted mandibular molars using cone beam computed tomographic(CBCT)imaging.Methods CBCT image data of 200 subjects were randomly collected from dental clinics.The root canal morphology of the mandibular anterior teeth was identified and classified by Vertucci's classification,and the root length and labio-lingual dimension at the tooth neck level were measured.The occurrence of three-rooted mandibular first molars was examined as well.The concurrence rates of double-canaled anterior teeth and three-rooted mandibular first molars at each side,and concurrence rates of bilateral double-canaled anterior teeth and three-rooted man-dibular first molars were calculated.Spearman correlation tests were applied to analyze the correlation between the double-canaled ante-rior teeth and three-rooted mandibular first molars,as well as the bilateral antimetric teeth.Results The incidence of double-canaled system was 10.4％,18.6％and 6.5％in mandibular central incisors,lateral incisors and canines,respectively;the bilateral concur-rence rates were 5.7％,11.1％and 3.0％,respectively,and Spearman correlation coefficients(rho)were 0.487,0.505 and 0.440(P＜0.01),respectively;gender difference and side difference were not detected(P＞0.05).The frequency of three-rooted mandibular first molars was 24.6％;gender difference was not detected(P＞0.05),while the incidence was significantly higher at the right side(29.0％)than the left side(20.3％)(P＜0.05).The bilateral concurrence rate was 17.4％,and a moderate correlation was detected(rho=0.666,P＜0.01).The concurrence rates between the double-canaled anterior teeth and three-rooted mandibular first molars at each side were very low(2.6％-7.6％),and Spearman correlation tests demonstrated that no correlation(P＞0.05)could be detected between them.Conclusion The lateral incisors exhibited the highest incidence of two root canals among the mandibular anterior teeth.Ad-ditionally,there was no significant corr-elation between three-rooted mandibular first molars and double-canaled mandibular anterior teeth.

Objective:To analyze the iodine nutrition status of children aged 8 to 10 years in Zhejiang Province from 2016 to 2021.Methods:A multi-stage stratified sampling method was used to select non-residential children aged 8 to 10 years from 90 counties in Zhejiang Province. A total of 114 103 children were included in the study from 2016 to 2021. Direct titration method and arsenic-cerium catalytic spectrophotometry were used to detect salt iodine content and urinary iodine level, respectively, to evaluate the iodine nutritional status of children. Ultrasound was used to detect thyroid volume and analyze the current prevalence of goiter in school-age children.Results:The age of 114 103 children was (9.04 ± 0.81) years old, with 50.0% of (57 083) boys. The median of iodine content M ( Q1, Q3) in children's household salt was 23.00 (19.80, 25.20) mg/kg, including 17 242 non-iodized salt, 6 173 unqualified iodized salt, and 90 688 qualified iodized salt. The coverage rate of iodized salt was 84.89%, and the coverage rate of qualified iodized salt was 79.48%. The proportion of non-iodized salt increased from 11.85% in 2016 to 16.04% in 2021 ( χ 2trend=111.427, P<0.001). The median of urinary iodine concentration M ( Q1, Q3) in children was 182.50 (121.00, 261.00) μg/L, among which the proportions of iodine deficiency, iodine suitability, iodine over suitability, and iodine excess were 17.25% (19 686 cases), 39.21% (44 745 cases), 26.85% (30 638 cases), and 16.68% (19 034 cases), respectively. The median of urinary iodine concentration in children in inland areas [ M ( Q1, Q3): 190.90 (128.80, 269.00) μg/L] was significantly higher than that in children in coastal areas [ M ( Q1, Q3): 173.00 (113.00, 250.30) μg/L] ( P<0.001). From 2016 to 2021, a total of 39 134 ultrasound examinations were conducted, and 1 229 cases of thyroid enlargement were detected. The goiter rate was 3.14% (95% CI: 2.97%-3.32%). The incidence of goiter in children in coastal areas [3.45% (95% CI: 3.19%-3.72%), 641/18 604] was higher than that in children in inland areas [2.86% (95% CI: 2.64%-3.10%), 588/20 530] ( P=0.001). Conclusion:From 2016 to 2021, the iodine nutrition level of children aged 8-10 years in Zhejiang Province is generally suitable, and the rate of goiter in children meets the limit of iodine deficiency disease elimination standards.

Objective To investigate the differential diagnostic value of 18F-fluorodeoxyglucose(18F-FDG)/PET/CT combined with serum lactate dehydrogenase(LDH),β2-microglobulin(β2-MG),and C-reactive protein(CRP)in sarcoidosis and lymphoma.Methods The 18F-FDG PET/CT images of 19 patients with sarcoidosis and 33 patients with lymphoma were analyzed retrospectively.The lymph node maximum diameter,density,distribution morphology,maximum standardized uptake value(SUVmax),extra-nodal involvement,and serum LDH,β2-MG,and CRP results were analyzed and compared.Results There was no statistically significant difference between sarcoidosis and lymphoma in lymph node density,necrosis rate,and SUVmax(P＞0.05).There was statistically significant difference in the maximum diameter between lymph nodes in sarcoidosis(2.4±0.7)cm and lymphoma(3.3±1.3)cm(P＜0.05).The incidence of symmetric enlargement of mediastinal and hilar lymph nodes was 84.2％in sarcoidosis,the lymph node fusion rate was 21.1％,the lung involvement rate was 57.8％,the spleen involvement rate was 10.5％,and the rates of lymphoma were 15.2％,63.6％,0.0％,and 36.4％,with statistically significant differences(P＜0.05).There were statistically significant differences in LDH and β2-MG between the two groups(P＜0.05),but the differences in CRP were not statistically significant(P＞0.05).Conclusion PET/CT can show the anatomy of mediastinal and hilar lymph nodes and extra-nodal affected organs as well as glucose metabolism,showing a certain differential diagnostic value of sarcoidosis and lymphoma when combined with serum LDH and β2-MG levels.

Objective:To summarize the practice and experience of medical service support for Shenzhou manned spaceflight mission, and to explore the accurate medical service support strategy with new regions and new types.Methods:A systematic summary was made from the force command, action framework, technical support, and the practice and experience in the application of medical support force for Shenzhou manned flight mission were sorted out.. Furthermore, the key and difficult problems of the new domains with new types of military medical service support were analyzed, and the scheme and significance of establishing the accurate support mode of the new medical service support force were proposed.Results:The Shenzhou emergency rescue mission was an elite combat supported by a large platform. It was an important basis to realize accurate medical service support by the experience of utilizing the medical force of Shenzhou emergency rescue and the strengthening of war-building mode optimization.Conclusions:This paper systematically summarizes the experience and characteristics of medical force application in Shenzhou manned spaceflight missions, and provides new ideas and methods for future diversified and accurate s medical service support with new regions and new types.

Objective:To explore the predictive value of low-dose biphasic (inspiratory and expiratory) CT air trapping sign and semi-quantitative score in predicting abnormal blood gas parameters and progression to severe disease in COVID-19 patients.Methods:Patients with non-severe COVID-19 who were diagnosed by nucleic acid testing and hospitalized in designated hospitals in Wuxi City from January 23 to February 29, 2020 were prospectively and consecutively recruited. All patients received low-dose biphasic CT examination on admission and repeated CT examination at regular intervals during the course. On the inspiratory phase admission of the bipolar CT, the scope of the lesion was evaluated by semi-quantitative score, and the air trapping sign on bipolar CT was assessed. The differences of semi-quantitative score, the presence of the air trapping sign and other clinical factors were compared between the patients with abnormal and the normal blood gas index, as well as between the cases progressed to severe disease and cases without disease progression using the independent sample t-test or χ 2 test. The area under the curve (AUC) of receiver operating characteristic (ROC) and the comprehensive discriminant improvement index (IDI) were used to evaluate the predictive effectiveness of the semi-quantitative scores, air trapping sign, and combination of two factors in differentiating cases with abnormal and normal blood gas indexes, as well as in differentiating cases with and without disease progression to severe COVID-19 cases. Results:In total 51 non-severe COVID-19 cases were included, with 16 cases showed air trapping sign during the first biphasic CT examination on admission. During the course of the disease, there were 13 patients with abnormal blood gas index, and 9 cases displaying air trapping sign (9/13). All 7 cases with progression to severe cases showed air trapping sign (7/7). Patients with advanced age, air trapping sign and higher semi-quantitative score were found more likely to have abnormal blood gas index ( t=3.10, χ 2=9.38, t=3.34, P<0.05); patients with advanced age, underlying diseases, air trapping sign and higher semi-quantitative score were more likely to develop into severe disease ( t=2.68, χ 2=6.65, χ 2=4.25, t=4.33, P<0.05). The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing abnormal blood gas index from normal blood gas index was 0.803, 0.754 and 0.794 respectively. The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing cases with progression to severe cases from non-progression was 0.881, 0.898 and 0.932, respectively. Air trapping sign combined with semi-quantitative score significantly improved the prediction effectiveness of disease progression, compared with semi-quantitative score or air trapping sign (IDI=0.271, 0.117). Conclusion:Air trapping sign and semi-quantitative score might be used as effective indicators to predict the progression of COVID-19 cases, and the combination of these two factors might be more helpful to predict the disease progression.

Objective: To examine the association of body mass index (BMI) and waist circumference (WC) with frailty among oldest-old adults in China. Methods: A total of 7 987 people aged 80 years and older (oldest-old) who participated in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2017-2018 were included. Information on demographic characteristics, behavior pattern, diet, activities of daily living, cognitive function, health status, disease condition were collected by questionnaire and physical examination. Generalized linear mixed model and restricted cubic splines (RCS) were used to analyze the association of BMI and WC with frailty. Results: The mean age of all participants was 91.7 years, and their mean BMI and WC were (21.3±3.5) kg/m² and (82.9±10.5) cm, respectively. The proportion of male was 42.3% (3 377/7 987), and the proportion of people with frailty was 33.7% (2 664/7 987). After controlling confounding factors, compared with T₂ (19.1-22.1 kg/m²) of BMI, the OR (95%CI) of the female T₁ (<19.1 kg/m²) and T₃ (≥22.2 kg/m²) group was 1.39 (1.17-1.65) and 1.27 (1.07-1.52), respectively. Compared with T₂ (77-85 cm) of WC, the OR (95%CI) of female T₁ (<77 cm) and T₃ (≥86 cm) group was 1.20 (1.01-1.42) and 1.10 (0.93-1.31), respectively. The results of multiple linear regression model with restrictive cubic spline showed that there was a non-linear association of BMI and WC with frailty in female. Conclusion: There is a U-shaped association of BMI and WC with frailty in female participants.
Adult ; Male ; Female ; Humans ; Aged, 80 and over ; Waist Circumference ; Body Mass Index ; Frailty/epidemiology* ; Activities of Daily Living ; China/epidemiology* ; Risk Factors

Background::The heavy metals cadmium (Cd) and mercury (Hg) are known to be widespread environmental contaminants and high occupational exposure adversely affects the risk of chronic kidney disease (CKD). However, evidence from epidemiological studies linking low Cd and Hg exposure (or non-industrial) to the risk of progression to CKD are conflicting. This study aimed to explore the association of low Cd and Hg exposure with the risk of CKD in Chinese adults aged ≥80 years.Methods::The participants were recruited for the Healthy Aging and Biomarkers Cohort Study in 2017, an ongoing perspective survey conducted in longevity areas in China initially involving 3016 older adults. We used logistic regression models to estimate odds ratios (ORs) with 95% confidence intervals of CKD setting Cd and Hg as categorical variables. Logistic regression with restricted cubic spline was used to characterize a dose-response relationships between Cd or Hg concentrations and the risk of CKD in the study population.Results::The ORs for the risk of CKD comparing the fourth to the first quartile of blood Cd, blood Hg, urine Cd, and urine Hg were 1.77, 1.57, 2.03, and 1.50, respectively. Restricted cubic spline models showed that blood Cd and urine Hg were significantly linearly correlated with the risk of CKD, while blood Hg and urine Cd were non-linearly correlated with the risk of CKD with a steeper slope at concentrations <2.30 μg/L and 3.30 μg/g creatinine.Conclusions::Our findings suggest that even low Cd and Hg exposure (or non-industrial) were associated with increased risk of CKD in Chinese oldest old, although we did not find a significant multiplicative and additive interaction between Cd and Hg levels in relation to the risk of CKD.

Objective:To explore the effect of precision nursing based on evidence-based concept in the perioperative period of patients with total knee arthroplasty (TKA) .Methods:From January 2018 to December 2020, 200 TKA patients admitted to the First Affiliated Hospital of Zhengzhou University were selected as the study subject by convenience sampling. The patients were divided into the control group and the observation group according to simple random sampling with 100 cases in each group. The control group adopted routine nursing, while the observation group conducted precise nursing based on evidence-based concept on the basis of the control group. The incidence of postoperative complications and knee function between the two groups were compared.Results:The incidence of complications in the observation group was lower than that in the control group, with a statistically significant difference ( P<0.05) . At one, three and six months after operation, the knee function score of New York Hospital for Special Surgery (HSS) in both groups showed an upward trend. The HSS scores of the observation group at one, three, six months after operation were higher than those of the control group, and the difference was statistically significant ( P<0.01) . Conclusions:The precision nursing based on the evidence-based concept has a definite effect in the perioperative nursing of patients with TKA, which can reduce complications and improve the knee function.

Objective To determine the effect of trunk motion control on knee biomechanics during single-leg landing. Methods Twenty male healthy basketball players were recruited. The kinematics, kinetics parameters and surface electromyogram (EMG) of knee joints under trunk motion control during single-leg landing were studied by using Vicon motion Analysis system, Kistler force platform and Noraxon surface EMG system. Results Compared with natural landing, there were significant differences in flexion angle at initial contact moment, peak flexion angle and peak flexion moment during deeply inspiratory landing and landing with a stick, and a significantly larger flexion angle at initial contact moment, a larger peak flexion angle and smaller peak flexion moment were also found. Compared with natural landing, there was no statistical difference in peak valgus angle and peak valgus moment, as well as EMG activity of hamstrings, quadriceps muscles of the knee during deeply inspiratory landing and landing with a stick. Conclusions Deeply inspiratory landing or landing with a stick reduce the risk of anterior cruciate ligament (ACL) injury, and the results provide the theoretical basis for prevention of ACL injuries in basketball players during landing.

Objective:To evaluate the stability of newly formed blood vessels in the carotid plaque using qualitative and quantitative analysis of contrast-enhanced ultrasound images and to investigate its correction with the occurrence of ischemic stroke.Methods:A total of 100 patients with carotid artery plaques diagnosed by routine ultrasound who received treatment between August 2017 and December 2019 in Haiyan People's Hospital, China were included in this study. They were divided into an ischemic stroke group ( n = 60) and a non-ischemic stroke group ( n = 40) according to the occurrence of stroke. Two groups of patients underwent contrast-enhanced ultrasound examination of the carotid artery. The correlation between the stability of the newly formed vessels in the carotid plaque and the occurrence of ischemic stroke was quantitatively analyzed. Results:Contrast-enhanced ultrasound results revealed low or medium intensity of echoes. The proportion of patients exhibiting grade 3-4 intensity of echoes in the ischemic stroke group was significantly higher than that in the non-ischemic stroke group ( P < 0.05). Time to peak in the ischemic stroke group was significantly shorter than that in the non-ischemic stroke group [(25.46 ± 3.25) seconds vs. (32.77 ± 4.28) seconds, t = 3.783, P = 0.000]. In the ischemic stroke group, peak intensity [(59.62 ± 10.18) dB vs. (47.53 ± 14.36) dB, t = 3.263, P = 0.000] and the area under the receiver operating characteristic curve [(2 365.37 ± 346.03) cm 2vs. (1 695.42 ± 525.44) cm 2, t = 4.981, P = 0.000] were significantly higher than those in the non-ischemic stroke group (both P < 0.05). Conclusion:Contrast-enhanced ultrasound visual scoring combined with quantitative ultrasonography technology can be used to assess the stability and possible development process of carotid plaques, which provide practical and reliable evidence for selecting a rational opportunity for clinical treatment of ischemic cerebrovascular disease and developing a reasonable treatment plan.