Objective To investigate the predictive value of quantitative parameters of contrast-enhanced ultrasound (CEUS) in evaluating kidneys from donation after brain death (DBD) for the occurrence of delayed graft function (DGF) in recipients. Methods The clinical data of 134 DBD donors and 202 corresponding kidneys and recipients were retrospective analyzed. The recipients were divided into DGF group (n=39) and non-DGF group (n=163) according to the renal function after kidney transplantation. Conventional ultrasound, CEUS parameters, and clinical data were compared between the two groups. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off values for predicting DGF using CEUS parameters, clinical parameters, and their combination, based on the highest Youden index. The predictive ability of different parameters for DGF was evaluated. Results There were statistically significant differences in cortical peak intensity (PIc), medullary peak intensity (PIm), donor albumin (ALB), serum creatinine (Scr) after admission, and the Na⁺ concentration of recipients between the two groups (all P<0.05). The area under the curve (AUC) for predicting DGF using the combination of CEUS parameters PIc and PIm was 0.711, with an optimal cut-off value of 0.193 and a Youden index of 0.382. The AUC for predicting DGF using the combination of CEUS parameters PIc, PIm and clinical parameters was 0.808, with an optimal cut-off value of 0.191 and a Youden index of 0.517. The sensitivity and specificity were 0.769 and 0.613 for the former, and 0.769 and 0.748 for the latter, respectively. The AUC for predicting DGF using CEUS parameters PIc and PIm combined with clinical parameters was significantly higher than that using CEUS parameters PIc and PIm (P<0.05). Conclusions The CEUS quantitative parameters PIc and PIm have good predictive value in assessing kidneys from DBD donors for DGF in recipients, and the diagnostic efficacy is better when combined with clinical parameters.

Objective:To investigate the effect of radon on the expressions of miR-16, miR-106b, miR-449a, let-7g, miR-21, miR-221 and miR-34a in peripheral blood plasma of miners.Methods:A total of 46 randomly selected miners worked underground(the underground group)and 38 miners worked aboveground (the control group). MiRNA levels in the underground and control groups were detected by qRT-PCR and their relationship with cumulative effective dose was further analyzed.Results:The levels of miR-106b, miR-21, miR-221 in plasma of the study group were significantly higher than those in the control group( Z=-2.32, -2.47, -2.79, P<0.05), the corresponding Fc values were 1.61, 1.75, 1.30, respectively. The levels of miR-16, miR-449a, let-7g and miR-34a were slightly higher than those in the control group ( P>0.05). After controlling of confounding factors such as age, BMI and smoking, the alteration of miR-16, miR-106b, let-7g, miR-21 and miR-221 in plasma of the underground group were positively correlated with the cumulative effective dose( t=2.50, 3.31, 2.60, 2.95, 3.25, P<0.05). No significant difference was observed in the plasma levels of miR-449a and miR-34a between the two groups ( P>0.05). Conclusions:miR-106b, miR-21 and miR-221 could be used as potential biomarkers of radon exposure.

In the study of oral orthodontics, the dental tissue models play an important role in finite element analysis results. Currently, the commonly used alveolar bone models mainly have two kinds: the uniform and the non-uniform models. The material of the uniform model was defined with the whole alveolar bone, and each mesh element has a uniform mechanical property. While the material of the elements in non-uniform model was differently determined by the Hounsfield unit (HU) value of computed tomography (CT) images where the element was located. To investigate the effects of different alveolar bone models on the biomechanical responses of periodontal ligament (PDL), a clinical patient was chosen as the research object, his mandibular canine, PDL and two kinds of alveolar bone models were constructed, and intrusive force of 1 N and moment of 2 Nmm were exerted on the canine along its root direction, respectively, which were used to analyze the hydrostatic stress and the maximal logarithmic principal strain of PDL under different loads. Research results indicated that the mechanical responses of PDL had been affected by alveolar bone models, no matter the canine translation or rotation. Compared to the uniform model, if the alveolar bone was defined as the non-uniform model, the maximal stress and strain of PDL were decreased by 13.13% and 35.57%, respectively, when the canine translation along its root direction; while the maximal stress and strain of PDL were decreased by 19.55% and 35.64%, respectively, when the canine rotation along its root direction. The uniform alveolar bone model will induce orthodontists to choose a smaller orthodontic force. The non-uniform alveolar bone model can better reflect the differences of bone characteristics in the real alveolar bone, and more conducive to obtain accurate analysis results.
Biomechanical Phenomena ; Computer Simulation ; Finite Element Analysis ; Humans ; Models, Biological ; Periodontal Ligament ; Stress, Mechanical ; Tooth Movement Techniques

Objective:To study serum procalcitonin (PCT), C-reactive protein (CRP) and platelet count (PLT) in evaluation of severity of acute cholangitis (AC).Methods:Ninety patients with AC who were treated at the General Surgery Department, Guangming Hospital, Liaocheng, Shandong Province from January 2016 to December 2018 entered into the observation group, while 60 patients with bile duct stones but without infection treated at the hospital during the study period entered into the control group. Using the " Guidelines for the Diagnosis and Treatment of Acute Biliary Tract Infections" , the study group of patient was further divided into the mild infection, moderate infection, and severe infection groups. The PCT, CRP and PLT levels of all the subjects were checked. Spearman correlation was used to analyze the relationship between PCT, CRP, PLT indexes with severity of infection. The receiver operating characteristic curve was used to analyze the sensitivity and specificity of PCT, CRP and PLT in the diagnosis of patients with different degrees of infection.Results:In the observation group, there were 46 males and 44 females with a Mean±SD age of (45.6±21.1) years. In the control group, there were 30 males and 30 females, with a Mean±SD age of (45.0±19.3) years. The levels of PLT in the observation group and the control group were (8.2±1.1) ng/ml and (0.4±0.1) ng/ml, respectively. The corresponding CRP were (92.7±21.1) mg/L and (6.1±1.0) mg/L, respectively. The observation group had higher levels than the control group. The PLT counts were (62.6±17.6)×10 9/L and (156.3±35.3)×10 9/L for the two groups, with the observation group having lower platelet count than the control group (both P<0.05). The severity of infection was positively correlated with blood PCT levels and CRP indicators ( r=0.427, r=0.584, all P<0.05), and negatively correlated with the PLT ( r=-0.429, P<0.05). The sensitivity and specificity of PCT using a cut-off value of 9.4 μg/L were 84.0% and 65.0%, respectively, which were higher than the CRP using a cut-off value of 145.7 mg/L. The sensitivity and specificity were 67.0% and 48.0%, respectively. When PLT using a cut-off value of 52.8×10 9/L, the sensitivity and specificity were 71.0% and 52.0%, respectively. Conclusions:Changes in serum PCT, CRP and PLT reflected the severity of infection in patients with AC; PCT had a higher sensitivity and specificity, and it can be used to guide treatment.

Objective To realize the extra-oral measurement of initial recovery force produced by orthodontic wire using simulated dental model. Methods A clinical patient was selected as the study objective, and maxillary dental models, which were in accordance with the real dentition of patient, were fabricated by three-dimensional printing. An orthodontic force measuring system was constructed using Nano17 F/T mechanical sensors to measure the initial recovery forces on two maxillary central incisors, which were produced by a standard circle Ni-Ti wire with the diameter of 355.6 μm after the archwire was assembled on the dental model. Results Central incisor 21 suffered a lager initial orthodontic force compared with incisor 11, and the force systems on two incisors were both adverse to tooth ideal movement, therefore, an assistive device was necessary to improve force status of the teeth. When the orthodontic treatment plan was optimized, a satisfactory result was obtained after 18 months of treatment. Conclusions Force systems caused by orthodontic wire and exerted on the teeth could be accurately measured using the simulated dental model of patient, so as to predict the teeth moving type, and improve teeth treatment plan on this basis. The extra-oral measuring technique of orthodontic force provides an important reference for clinical orthodontic treatment, and creates a novel idea for the optimal design of orthodontic plan.

OBJECTIVES: To investigate the clinical characteristics and risk factors for severe events of coronavirus disease 2019 (COVID-19) in elderly patients. METHODS: Retrospective analysis was performed on the clinical data of all elderly COVID- 19 patients treated in Changsha Public Health Treatment Center from January 17, 2020 to March 15, 2020, which included basic diseases, symptoms, test results, and other clinical characteristics, and prognostic indicators such as severity of illness, length of hospital stay, virus shedding time and mortality rate. The differences in clinical characteristics and prognostic indicators between elderly, middle-aged, and young COVID-19 patients were also analyzed. Logistic regression model was used to conduct univariate and multivariate analysis of risk factors for developing severe events in elderly COVID-19 patients; receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction efficacy. RESULTS: Of the 230 COVID-19 adult patients, 34 were young patients (14.8%), 136 were middle-aged patients (59.1%), and 60 were elderly (26.1%). Among the 60 elderly patients, 23 were male (38.3%) and 37 were female (61.7%), with a medium age of 66 years old. Common symptoms were fever (66.7%), cough (50.0%), and fatigue (41.7%). C reactive protein (CRP) was increased significantly. The proportion of severe cases was 31.7%, and mortality was 1.7%. The median length of hospitalization and median virus shedding time were 18.5 days and 21 days, respectively. Compared with the young and the middle-aged patients, the elderly had a higher proportion of hypertension, diabetes, and cardiovascular diseases, more common shortness of breath, higher proportions of pneumonia and severe cases (all <0.05), and the decreased lymphocyte count and lymphocyte percentage (both <0.05), as well as higher CRP and erythrocyte sedimentation rate (ESR) levels (both <0.05). Compared with non-severe cases, severe elderly patients demonstrated higher CRP and aspartate aminotransferase (AST) levels (all <0.05), the reduced lymphocyte count (<0.05), and the prolonged length of hospitalization and virus shedding duration (both <0.05). Univariate logistic regression analysis indicated that the lymphocytes proportion, CRP and AST levels were significantly correlated with the risk for developing severe events in elderly COVID-19 patients (all <0.05). Multivariate logistic regression found that severe events in elderly patients with COVID-19 were significantly correlated with CRP level (OR=1.041, =0.013). ROC curve analysis revealed that the area under the curve (AUC) for CRP to diagnose severe events in elderly COVID 19 patients was 0.851. CONCLUSIONS The proportion of severe cases in elderly COVID-19 patients is higher than that in young and middle-aged patients. CRP level has a good predictive value for the possibility of severe events in elderly COVID-19 patients.
Adult ; Aged ; Betacoronavirus ; C-Reactive Protein ; analysis ; China ; Comorbidity ; Coronavirus Infections ; diagnosis ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; physiopathology ; Retrospective Studies ; Risk Factors

Objective To observe potential effect of radon hot springs on the changes of cell cycle and its regulatory proteins of CDK1,CDK2,CDK4,CDK6,CyclinD1,CyclinE1,WEE1,CDC25A in the peripheral blood lymphocytes of residents.Methods A random sampling method was used to persons 46 persons from the residents around radon hot spring in Wentang town,and 39 persons were selected from the control area without radon exposure.Flow cytometry was used to detect the changes of cell cycle and the expressions of cell cycle-related regulatory proteins.Multiple linear regression method was used to analyze the relationship between the expressions of cell cycle regulatory proteins and radon exposure.Results The percentages of cells at G0/G1 phase and S phase in lymphocytes were different in the two groups (t =2.250,-2.382,P ＜ 0.05).The expression levels of CDK1,CDK6 and CyclinE1 in the peripheral blood lymphocytes of radon hot spring group were significantly decreased (t =4.770,11.419,5.238,P ＜ 0.05) and negatively correlated with radon exposure (t =-5.097,-11.128,-5.117,P ＜0.05).The expression levels of CDK2,CDK4,CyclinD1,WEE1 and CDC25A in the peripheral blood lymphocytes of radon hot spring group were increased but not significantly(P ＞ 0.05).Conclusions The incidences of a higher ratio of S-phase cells and lower expression levels of CDK1,CDK6 and CyclinE1 in the peripheral blood lymphocytes of residents in Wentang town may be related to long-term radon exposure.

Objective To analyze the biological dose estimation ability of the radiation health technology institutions nationwide from 2015 to 2017,and their development in recent years.Methods SPSS 19.0 software was used to analyze and pack the data involved in the 2015-2017 year assessments by using x2 test.Statistical analysis was conducted of qualification rate,excellent rate,participating units and dose estimation deviation distribution.Results The qualification rate gradually increased from 2015 to 2017.Compared with 2015,the passing rate significantly increased in 2017 with statistically significant difference(x2 =3.978,P ＜0.05).A total of 53 units participated in the biological dose assessment,of which 30 units were involved over the three consecutive years,accounting for 57％.In the distribution of the relative deviation of dose estimates made by the units participating in the three-year assessment,the proportion of estimated deviations in the range of 5％-10％ increased whereas those in the range of 15％-20％ and ＞ 20％ decreased.Conclusions During 2015-2017 year period the biological dose estimation ability of all units involved in the assessment nationwide was basically stable,with gradually improved test level,qualification rate and steady excellence rate.

Objective To explore the role of γ-synuclein(SNCG) siRNA in the radiosensitivity of breast cancer T47D cells.Methods SNCG siRNA was synthesized according to the coding sequence of SNCG mRNA and then transiently transferred into T 47D cell with lipofectamine .The expression of SNCG gene and protein was detected by RT-PCR and Western-blot, respectively.Cells were divided into three groups, SNCG siRNA interference group , negative control group and blank control group , which were irradiated with different doses of 60 Coγ-rays.Cell radiosensitivity was evaluated by colony formation assay , cell proliferation was assayed by CCK-8 kit, and the protein expressions of phosphorylated-AKT and mTOR were detected by Western blot assay .Results Compared with blank control cells , the expressions of SNCG gene and protein in the SNCG siRNA transferred T 47D cells were efficiently diminished .Cell colony formation results showed that , under 4, 6, 8 Gy irradiation, the cell survival of siRNA transfection group was lower than that of control group (t=5.449, 8.882, 21.503, P<0.05).CCK-8 experiments showed that the cell proliferation abilities of siRNA group at 24, 48, 72 h after 6 Gy irradiation were lower than those of control group (t=5.603, 4.839, 6.115, P<0.05).In addition, after 6 Gy irraddaition, the AKT and mTOR phosphorylation levels in the siRNA group were more obviously reduced compared with blank groups , but the total AKT and mTOR had no changes .Conclusions Transfection of SNCG siRNA can enhance the radiosensitivity of breast cancer cells probably by inhibiting p -AKT signal pathway .

Objective To explore the effects of high background radiation on the expressions of miR-16, miR-106b, miR-449a, miR-34a and let-7g in peripheral blood plasma of the residents .Methods Totally 110 healthy female long-term local residents aged over 50 years were randomly selected from the high background radiation area and the control area , while their age, body mass index(BMI) and other indicators were surveyed .The relative expression levels of miRNAs in peripheral blood plasma of these women were quantitatively detected by real-time fluorescence quantitative PCR ( RT-PCR) .Then t-test was used to analyze the cumulative dose , age and BMI between the high background and control group .Mann-Whitney U-test was used for statistical analysis of miRNA expression levels between two groups , and the multiple regression analysis was used finally .Results Compared with the control group , the cumulative dose of individuals in the high background group was about four times higher (t=42.803, P<0.05), and the levels of miR-16 and miR-106b in plasma of high background group were down-regulated, while the level of miR-449a was up-regulated ( Z =4.180, 2.422, 2.794, P <0.05 ).After controlling of confounding factors such as age and BMI , the expression levels of miR-16 and miR-106b were negatively correlated with the cumulative dose of individuals (P<0.05).On the contrary, no significant correlation was observed between the levels of miR-449a, miR-34a, let-7g and the individual cumulative dose (P>0.05).Conclusions miR-16 and miR-106b may serve as biomarkers for the early stage of low dose radiation health effects .