Background Under the background of global climate change, temperature has increased dramatically. Most studies about association between temperature and human health are conducted in low-altitude areas, but rarely focus on plateau areas. Objective To examine the association between temperature and non-accidental mortality risk in Tibet Plateau, China and to identify vulnerable populations for formulating targeted policies of climate change adaptation. Methods The mortality data, meteorological data, and pollutant data of Tibet area between 2013 to 2019 were collected. Based on time-stratified case-crossover design, conditional logistic regression models were used to analyze the exposure-response relationship between temperature and cause-specific mortality, which was linearized to obtain excess risk for 1 ℃ change; attributable fraction was calculated for assessing burden attributable to temperature; and stratified analyses were further conducted by gender, age (＜65 years old, ≥65 years old), and causes of death (cardiovascular diseases, cerebrovascular diseases, and respiratory diseases). Sensitivity analyses were conducted by adjusting model parameters and variables. Results A total of 26 045 non-accidental deaths were collected in Tibet during 2013 and 2019, and the P₅₀ of temperature was 5.0 ℃. The non-accidental mortality risk increased as temperature become colder. A 1 ℃ decrease in temperature was associated with a 2.01% (95%CI: 0.94%-3.07%) increase in total non-accidental mortality, while the association changed to 2.05% (95%CI: 0.62%-3.47%) for male and 1.96% (95%CI: 0.34%-3.56%) for female, both of statistial significance; 1.45% (95%CI: −0.10%-2.98%) for the people <65 years old (not of significance) and 2.52% (95% CI : 1.04%-3.99%) for the people ≥65 years old (of significance); the excess risk for cardiovascular mortality was 2.65% (95%CI: 1.03%-4.24%), for cerebrovascular mortality was 3.70% (95%CI: 0.74%-6.57%), both of statistical significance, and for respiratory mortality was 2.18% (95%CI: −0.14%-4.44%), without significance. The total attribution number of non-accidental mortality was 5340 (95%CI: 2719-7528), and the total attributable fraction was 20.50% (95%CI: 10.44%-28.91%). The attributable fractions were higher in specific subgroups like male (20.72%), people ≥65 years (23.33%), and people with cardiovascular diseases (26.07%). Conclusion The exposure-response relationship between temperature and non-accidental mortality in Tibet showes that the non-accidental mortality risk increase as temperature become colder. The attributable burden of disease is heavy. Residents being male, ≥65 years, with cardiovascular diseases and respiratory diseases may be vulnerable to nonoptimal temperature.

Objective To compare the epidemiological characteristics of COVID-19 in Guangzhou and Wenzhou, and evaluate the effectiveness of their prevention and control measures. Methods Data of COVID-19 cases reported in Guangzhou and Wenzhou as of 29 February, 2020 were collected. The incidence curves of COVID-19 in two cities were constructed. The real time reproduction number ( R t ) of COVID-19 in two cities was calculated respectively. Results A total of 346 and 465 confirmed COVID-19 cases were analysed in Guangzhou and Wenzhou, respectively. In two cities, most cases were aged 30-59 years (Guangzhou: 54.9%; Wenzhou: 70.3%). The incidence curve peaked on 27 January, 2020 in Guangzhou and on 26 January, 2020 in Wenzhou, then began to decline in both cities. The peaks of imported COVID-19 cases from Hubei occurred earlier than the peak of COVID-19 incidences in two cities, and the peak of imported cases from Hubei occurred earlier in Wenzhou than in Guangzhou. In early epidemic phase, imported cases were predominant in both cities, then the number of local cases increased and gradually took the dominance in Wenzhou. In Guangzhou, the imported cases was still predominant. Despite the different epidemic pattern, the R t and the number of COVID-19 cases declined after strict prevention and control measures were taken in Guangzhou and in Wenzhou. Conclusion The time and scale specific differences of imported COVID-19 resulted in different epidemic patterns in two cities, but the spread of the disease were effectively controlled after taking strict prevention and control measures.

Objective To investigate the clinical and CT features of basal cell adenomas (BCA)of parotid gland,and to improve the understanding of the disease.Methods Clinical and CT data of 1 8 patients with BCA of parotid gland confirmed by surgery and pathology were collected.The characteristics of age,sex,clinical symptom,lesion site,number,size,shape,density and CT dualGphase enhancement of the lesions were retrospectively analyzed.Results (1)Age and sex of onset:1 2 cases(6 6.6 7%)of age stage from 30 to 5 9,5 cases (27.78%)of the elder over 60,1 case of the younger below 29,5 cases (27.78%)for males,1 3cases (72.22%)for females,the incidence ratio of male to female being 1 ︰ 2.5.(2)Clinical manifestations:there were sporadic masses in the parotid region,3 cases were accompanied by mild pain and all patients had no facial nerve symptoms.(3)Location site,number,size:23 lesions in 18 cases, of which 15 cases (83.3%)were single and 3 cases (16.7%)had multiple lesions on one side.17 lesions (73.9%)were located in superficial lobe, and 6 lesions (26.1%)were located in the deep lobe;(4)Shape and cross section diameter:the shape of the tumor was round or ellipse with wellG defined margin,13 cases (56.5%)of the round shape,10 cases (43.5%)of the ellipse;the maximum cross section diameter was (2.49±1.3 8)cm,the superficial lobe group was (2.05 ±1.02)cm,and the deep lobe group was (3.73 ±1.59)cm.The difference between the two groups on the maximum cross section diameter was significant (P＜ 0.05).(5)Density:the density of most lesions was heterogeneous.17 lesions were accompanied by central or peripheral cystic degeneration of varying degrees,of which 10 lesions with cystic regions ＞ 50% and 2 lesions with maximum transverse diameter ＜ 0.8 cm.(6)CT dualGphase enhancement:19 lesions showed obvious homogeneous or heterogeneous enhancement on the arterial phase,and persistent enhancement on the venous phase.4 lesions showed progressive heterogeneous enhancement,and the enhancement degree of venous phase was even higher than that of arterial phase.Conclusion The BCA of the parotid gland aremainly occuring in middleGaged and older women,displaying regular shape of lesions,developing to cystic degeneration easily and presenting＂fastGelevation and sustained enhancement＂or progressive enhancement patterns in the dualGphase enhanced scans.These characteristics are helpful to make a diagnosis preoperatively.

Objective To explore the value of combined application of prenatal ultrasound and MRI in diagnosis of fetal agenesis of corpus callosum (ACC).Methods The fetal brain ultrasound and MRI examination were performed in 1 1 7 fetuses with enlarged posterior horn of lateral ventricle and diaphanous diaphragm reduction or disappearance,and compared with postpartum diagnosis.Results Among the 48 cases of postpartum ACC confirmed by MRI,40 cases were diagnosed by prenatal ultrasound and 45 cases by prenatal MRI,and the sensitivity of the two methods was 83.33%,93.75% respectively(P<0.05).The sensitivity of combined diagnosis was 95.83%. Conclusion Fetal craniocerebral ultrasound combined with MRI can accurately diagnose fetal ACC,especially improve the detection rate of partial corpus callosum deletion,and provide a reliable basis for clinical diagnosis.

Objective To explore the value of ultrasound-guided balloon control technique in abdominal aorta for reducing intraoperative hemorrhage in high-risk placenta previa undergoing cesarean section.Methods From Aug 2013 to Oct 2017,40 cases were admitted,among them,16 cases were treated with ultrasound-guided towed balloon prophylactic control technique of abdominal aorta (the study group) before cesarean,and 24 cases did not receive balloon occlusion (the control group) during the cesarean.Clinical data were compared between the two groups.Results The time used for uterine suture (t =10.34,P =0.01),the amount of intraoperative blood loss (t =9.51,P =0.01) and blood transfusion (t =3.41,P=0.005)in the two groups were all statistically different.While the differences in PT (t =1.02,P =0.32),ALT (t =0.54,P =0.59),AST(t =0.91,P =0.37),creatinine(t =0.75,P =0.46) were not statistically significant between the two groups.Conclusion Ultrasound-guided abdominal aortic balloon control technique can reduce the blood loss significantly in cesarean section with high-risk placenta previa.

Objective To explore the imaging biomarker for early diagnosis and disease course monitoring of Parkinson disease (PD) in arterial spin labeling (ASL) technique. Methods Between July, 2014 and May, 2017, 23 patients with PD underwent magnetic resonance imaging (MRI) and ASL examinations in our hospital, including 13 in the early stage and 10 in advanced stages. Voxel-based analysis (VBA) was used to observe the regional cerebral blood flow (rCBF) characteristics in PD patients in different stages and three-dimensional continuous arterial spin labeling (3D CASL) was used to analyze the mean cerebral blood flow (mCBF). Results No significant difference was found in mCBF among PD patients in the early stage, patients in advanced stages and normal control subjects (P=0.30). Compared with the normal control group, the patients with early-stage PD had decreased rCBF in resting state mainly in the right superior occipital gyrus and the right superior frontal gyrus as revealed by VBA (P<0.001);the patients with advanced PD showed decreased rCBF mainly in the left precentral gyrus and the postcentral gyrus (P<0.001). The patients with advanced PD exhibited lowered rCBF in the right substantia nigra and the bilateral corpus callosum as compared with the early-stage patients (P<0.001). Conclusions VBA of ASL reveals rCBF alterations in association with the disease progression in PD patients, suggesting that this technique might provide assistance in identification of potential markers for early PD diagnosis and for monitoring the disease course.

Objective To explore the imaging biomarker for early diagnosis and disease course monitoring of Parkinson disease (PD) in arterial spin labeling (ASL) technique. Methods Between July, 2014 and May, 2017, 23 patients with PD underwent magnetic resonance imaging (MRI) and ASL examinations in our hospital, including 13 in the early stage and 10 in advanced stages. Voxel-based analysis (VBA) was used to observe the regional cerebral blood flow (rCBF) characteristics in PD patients in different stages and three-dimensional continuous arterial spin labeling (3D CASL) was used to analyze the mean cerebral blood flow (mCBF). Results No significant difference was found in mCBF among PD patients in the early stage, patients in advanced stages and normal control subjects (P=0.30). Compared with the normal control group, the patients with early-stage PD had decreased rCBF in resting state mainly in the right superior occipital gyrus and the right superior frontal gyrus as revealed by VBA (P<0.001);the patients with advanced PD showed decreased rCBF mainly in the left precentral gyrus and the postcentral gyrus (P<0.001). The patients with advanced PD exhibited lowered rCBF in the right substantia nigra and the bilateral corpus callosum as compared with the early-stage patients (P<0.001). Conclusions VBA of ASL reveals rCBF alterations in association with the disease progression in PD patients, suggesting that this technique might provide assistance in identification of potential markers for early PD diagnosis and for monitoring the disease course.

Objective To compare and analyze the diagnostic value of prenatal ultrasound and MRI in fetal thoracic abnormalities, as well as the advantages and disadvantages, respectively, and to explore the clinical value of the combined use in diagnosing fetal thoracic abnormalities.Methods The prenatal ultrasound and MRI images of total 94 cases with thoracic abnormalities were analyzed retrospectively.All the patients received MRI exams within 2 days after the preliminary ultrasound diagnosis of abnormalities.All cases were confirmed by autopsy or postnatal follow-ups.Results 94 cases of thoracic abnormalities included 48 cases of cystic adenoma abnormalities, 33 cases of bronchopulmonary sequestration, 10 cases of diaphragmatic hernia and 3 cases of primary pulmonary hypoplasia.The diagnosis coincidence rate of ultrasound was 82.98% (78/94), while the combined use was 93.62% (88/94).There were statistical differences between the combined use and single ultrasound examination in detecting fetal thoracic abnormalities(P<0.05).Conclusion Both ultrasound and MRI could diagnose fetal thoracic abnormalities well and had its own advantages and disadvantages.The combined use of ultrasound and MRI could improve the sensitivity and specificity of prenatal diagnostic accuracy and have a better advantage in diagnosing fetal thoracic abnormalities.

Objective To explore the application value of 256-slice high resolution CT(HRCT)and reconstuction technique in the preoperative assessment of ossicular chain trauma.Methods 106 cases of temporal bone trauma were scanned using 256-slice HRCT,38 cases of ossicular chain trauma were collected.The multi-planar reformaition(MPR),curved plannar reformation(CPR) and three-dimensional volume rendering reformation (3D VR)of the ossicular chain were performed on Philips work station.The locations, types and the involving structures were analyzed,then these cases were followed up.The display rates of AX,MPR,CPR,3D VR were evaluated.Results Among 106 cases of temporal bone trauma,38 cases(76 ears)were found ossicular chain trauma,in which there were 43 ears of ossicular dislocation,22 ears incudomalleolar joint separation,6 ears incudomalleolar and incudostapedial joint separation,3 ears incudostapedial joint separation,11 ears translocation of the ossicles,1 ear stapediovestibular dislocation;4 ears ossicular fractures,2 ears fracture of the malleus,1 ear fracture of the incus,1 ear fracture of the stapes.Among 38 cases,11 cases underwent surgery,and the surgical results were consistent with CT findings.The display rates of AX,MPR,CPR,3D VR were 97.87％,100％, 97.87％,82.98％ respectively.Conclusion 256-slice HRCT and reconstuction technique can clearly reveal the whole structure of ossicular chain trauma,which are effective methods for diagonsis of ossicular chain trauma before surgery.

Objective To investigate the correlation between mammographic findings and different molecular subtypes of breast cancer.Methods Totally 84 patients with breast cancer proved pathologically who underwent digital mammography examination before operation were enrolled.All cases were examined by immunohistochemical staining,the expression levels of estrogen receptor(ER),progesterone receptor (PR)and human epidermal growth factor receptor-2(HER-2)in tumor cells were analyzed.They were classified into four molecular subtypes:Luminal A,Luminal B,HER-2 + and Basal-like tumors according to their expression levels.The correlation between mammographic findings and different molecular subtypes of breast cancer were analyzed.Results Among the 84 cases of breast cancer,there were significant differences between mass shadow and mass shape in the four subtypes of tumors(P<0.05).Luminal A,Luminal B breast cancer showed more irregular edge of the tumor;HER-2 + breast cancer with more malignant calcifications,of which simple calcifications of breast cancer were more;Basal-like breast cancer with regular shape,clear border shadow,rarely accompanied by malignant calcifications.Conclusion Mammographic features of breast cancer can predict its molecular subtypes to some extent,which can provide objective basis for the selection of clinical preoperative treatment protocols.