Improving on mapping long-term surface water with a novel framework based on the Landsat imagery series

Surface water plays a crucial role in the ecological environment and societal development. Remote sensing detection serves as a significant approach to understand the temporal and spatial change in surface water series (SWS) and to directly construct long-term SWS. Limited by various factors such as cloud, cloud shadow, and problematic satellite sensor monitoring, the existent surface water mapping datasets might be short and incomplete due to losing raw information on certain dates. Improved algorithms are desired to increase the completeness and quality of SWS datasets. The present study proposes an automated framework to detect SWS, based on the Google Earth Engine and Landsat satellite imagery. This framework incorporates implementing a raw image filtering algorithm to increase available images, thereby expanding the completeness. It improves OTSU thresholding by replacing anomaly thresholds with the median value, thus enhancing the accuracy of SWS datasets. Gaps caused by Landsat7 ETM + SLC-off are respired with the random forest algorithm and morphological operations. The results show that this novel framework effectively expands the long-term series of SWS for three surface water bodies with distinct geomorphological patterns. The evaluation of confusion matrices suggests the good performance of extracting surface water, with the overall accuracy ranging from 0.96 to 0.97, and user's accuracy between 0.96 and 0.98, producer's accuracy ranging from 0.83 to 0.89, and Matthews correlation coefficient ranging from 0.87 to 0.9 for several spectral water indices (NDWI, MNDWI, ANNDWI, and AWEI). Compared with the Global Reservoirs Surface Area Dynamics (GRSAD) dataset, our constructed datasets promote greater completeness of SWS datasets by 27.01%-91.89% for the selected water bodies. The proposed framework for detecting SWS shows good potential in enlarging and completing long-term global-scale SWS datasets, capable of supporting assessments of surface-water-related environmental management and disaster prevention.

[Establishment and efficiency test of a clinical prediction model of bronchopulmonary dysplasia associated pulmonary hypertension in very premature infants]

Objective: To develop a risk prediction model for identifying bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH) in very premature infants. Methods: This was a retrospective cohort study. The clinical data of 626 very premature infants whose gestational age <32 weeks and who suffered from BPD were collected from October 1st, 2015 to December 31st, 2021 of the Seventh Medical Center of the People's Liberation Army General Hospital as a modeling set. The clinical data of 229 very premature infants with BPD of Hunan Children's Hospital from January 1 st, 2020 to December 31st, 2021 were collected as a validation set for external verification. The very premature infants with BPD were divided into PH group and non PH group based on the echocardiogram after 36 weeks' corrected age in the modeling set and validation set, respectively. Univariate analysis was used to compare the basic clinical characteristics between groups, and collinearity exclusion was carried out between variables. The risk factors of BPD associated PH were further screened out by multivariate Logistic regression, and the risk assessment model was established based on these variables. The receiver operating characteristic (ROC) area under curve (AUC) and Hosmer-Lemeshow goodness-of-fit test were used to evaluate the model's discrimination and calibration power, respectively. And the calibration curve was used to evaluate the accuracy of the model and draw the nomogram. The bootstrap repeated sampling method was used for internal verification. Finally, decision curve analysis (DCA) to evaluate the clinical practicability of the model was used. Results: A total of 626 very premature infants with BPD were included for modeling set, including 85 very premature infants in the PH group and 541 very premature infants in the non PH group. A total of 229 very premature infants with BPD were included for validation set, including 24 very premature infants in the PH group and 205 very premature infants in the non PH group. Univariate analysis of the modeling set found that 22 variables, such as artificial conception, fetal distress, gestational age, birth weight, small for gestational age, 1 minute Apgar score ≤7, antenatal corticosteroids, placental abruption, oligohydramnios, multiple pulmonary surfactant, neonatal respiratory distress syndrome (NRDS)>stage Ⅱ, early pulmonary hypertension, moderate-severe BPD, and hemodynamically significant patent ductus arteriosus (hsPDA) all had statistically significant influence between the PH group and the non PH group (all P<0.05). Antenatal corticosteroids, fetal distress, NRDS >stage Ⅱ, hsPDA, pneumonia and days of invasive mechanical ventilation were identified as predictive variables and finally included to establish the Logistic regression model. The AUC of this model was 0.86 (95%CI 0.82-0.90), the cut-off value was 0.17, the sensitivity was 0.77, and the specificity was 0.84. Hosmer-Lemeshow goodness-of-fit test showed that P>0.05. The AUC for external validation was 0.88, and the Hosmer-Lemeshow goodness-of-fit test suggested P>0.05. Conclusions: A high sensitivity and specificity risk prediction model of PBD associated PH in very premature infants was established. This predictive model is useful for early clinical identification of infants at high risk of BPD associated PH.

[Analysis of the relationship between MRI imaging characteristics and clinical symptoms and therapeutic efficacy in adenomyosis patients]

Objective: To investigate the relationship between magnetic resonance imaging (MRI) imaging characteristics and clinical symptoms and therapeutic efficacy in adenomyosis patients. Methods: The clinical characteristics of the adenomyosis questionnaire was self-designed. This was a retrospective study. From September 2015 to September 2020, totally 459 patients were diagnosed with adenomyosis and underwent pelvic MRI examination at Peking University Third Hospital. Clinical characteristics and treatment were collected, MRI was used to determine the lesion location, and to measure the maximum lesion thickness, the maximum myometrium thickness, uterine cavity length, uterine volume, the minimum distance between the lesion and serosa or endometrium, and whether combined with ovarian endometrioma. The difference of MRI imaging characteristics in patients with adenomyosis and its relationship with clinical symptoms and therapeutic efficacy were analyzed. Results: (1) Among the 459 patients, the age was (39.1±6.4) years. There were 376 patients (81.9%, 376/459) with dysmenorrhea. Whether patients had dysmenorrhea were related to uterine cavity length, uterine volume, ratio of the maximum lesion thickness to the maximum myometrium thickness, and whether patients had ovarian endometrioma (all P<0.001). Multivariate analysis suggested that ovarian endometrioma was the risk factor for dysmenorrhea (OR=0.438, 95%CI: 0.226-0.850, P=0.015). There were 195 patients (42.5%, 195/459) with menorrhagia. Whether patients had menorrhagia were related to age, whether patients had ovarian endometrioma, uterine cavity length, the minimum distance between lesion and endometrium or serosa, uterine volume, ratio of the maximum lesion thickness to the maximum myometrium thickness (all P<0.001). Multivariate analysis suggested that ratio of the maximum lesion thickness to the maximum myometrium thickness was the risk factor for menorrhagia (OR=774.791, 95%CI: 3.500-1.715×10⁵, P=0.016). There were 145 patients (31.6%, 145/459) with infertility. Whether the patients had infertility were related to age, the minimum distance between lesion and endometrium or serosa, and whether patients had ovarian endometrioma (all P<0.01). Multivariate analysis suggested that young and large uterine volume were risk factors for infertility (OR=0.845, 95%CI: 0.809-0.882, P<0.001; OR=1.001, 95%CI: 1.000-1.002, P=0.009). (2) The success rate of in vitro fertilization-embryo transfer (IVF-ET) was 39.2% (20/51). Dysmenorrhea, high maximum visual analogue scale score and large uterine volume affected the success rate of IVF-ET (all P<0.05). The smaller the maximum lesion thickness, the smaller the distance between the lesion and serosa, the larger the distance between the lesion and endometrium, the smaller the uterine volume, and the smaller the ratio of the maximum lesion thickness to the maximum myometrium thickness, the better the therapeutic efficacy of progesterones (all P<0.05). Conclusions: Concomitant ovarian endometrioma increases the risk of dysmenorrhea in patients with adenomyosis. The ratio of the maximum lesion thickness to the maximum myometrium thickness is an independent risk factor for menorrhagia. Young and large uterine volume may increase the risk of infertility. Severe dysmenorrhea and large uterine volume affect the success rate of IVF-ET. The therapeutic efficacy of progesterones is relatively better when the lesion is small and far away from the endometrium.

[Investigation of human brucellosis diagnosis and report quality in medical institutions in key areas of Shanxi province]

Objective: To evaluate the accuracy of human brucellosis diagnosis and reporting in medical institutions in Shanxi province, and understand the performance of clinical doctors to diagnose human brucellosis according to diagnostic criteria. Methods: Field investigation was conducted in 6 medical institutions in the key areas of human brucellosis in Shanxi province. The diagnosis data of the reported brucellosis cases in 2015 were collected and reviewed retrospectively for the evaluation of the diagnosis accuracy with systematic sampling method. The database was established with Excel 2010 and the descriptive analysis and statistical test were conducted with software R 3.3.2. Results: The diagnosis consistent rate of the 377 brucellosis cases reviewed was 70.8% (267/377), the diagnosis consistent rates in medical institutions at city-level and country-level were 77.0% (127/165) and 66.0% (140/212) respectively, the differences had significance (χ(2)=5.4, P=0.02). Among the reviewed cases, the diagnosis consistent rate of laboratory diagnosis and clinical diagnosis were 87.1% (256/294) and 13.3% (11/83) respectively, and the differences had significance (χ(2)=170.7, P<0.001). Among the 21 investigated clinical doctors, the numbers of the doctors who correctly diagnosed the suspected cases, probable cases and lab-confirmed cases were only 3, 0 and 8 respectively. All of the clinical doctors knew that it is necessary to report the brucellosis cases within 24 hours after diagnosis. Conclusion: The accuracy of human brucellosis diagnosis in key areas of human brucellosis in Shanxi was low, and the performance of the clinical doctors to diagnose human brucellosis according to diagnostic and case classification criteria was unsatisfied.

Spectrum and features of congenital heart disease in Xi'an, China as detected using fetal echocardiography

This study aimed to investigate the spectrum and features of congenital heart disease (CHD) in Xi'an, China using fetal echocardiography. All pregnant women referred for fetal echocardiography underwent a systematic fetal echocardiographic examination. Each case of complex defects was diagnosed according to the predominant pathophysiology, and the overall frequency of each defect was recorded and classified according to its location in the fetal heart. CHD was diagnosed in 195 fetuses. The top 5 types of CHD were, in order, single ventricle (15.9%, 31/195), atrioventricular septal defect (12.3%, 24/195), ventricular septal defect (VSD) (11.8%, 23/195), tetralogy of Fallot (10.8%, 21/195), and double-outlet right ventricle (8.2%, 16/195). The 195 cases of CHD comprised 316 defects in total. The most common defect was ventricular malformation (40.5%, 128/316), followed by great artery anomalies (38.0%, 120/316), endocardial cushion abnormalities (11.7%, 37/316), atrial abnormalities (6.6%, 21/316), and semilunar valve abnormalities (3.2%, 10/316). VSD accounted for the largest proportion (24.4%, 77/316) of the ventricular malformations. The total proportion of obstructive lesions in this group was much higher for the right than for the left side of the heart (18.4% (58/316) vs 9.5% (30/316), respectively). The spectrum of fetal CHD detected by echocardiography was much different compared to that accepted in the past. Complex defects were more common prenatally. Ventricular malformations were the largest constituent of all of the defects associated with fetal CHD, and VSD was the most common component of complex defects. Chinese fetal CHD encompassed more right-sided than left-sided obstructive lesions.

Relationship between smoking and dyslipidemia in western Chinese elderly males

The relationship between smoking and dyslipidemia was studied in 2,160 elderly Chinese males. Levels of triglycerides (TGs) in current smokers were shown to be significantly higher and levels of high-density lipoprotein cholesterol (HDL-C) lower than for those who had never smoked or had stopped smoking. Interestingly, the level of apoprotein B (apoB) was more frequently abnormal in very heavy smokers compared with light smokers, while low-density lipoprotein cholesterol (LDL-C) levels were more frequently normal in very heavy smokers. When comparing other factors that influence blood lipids, such as alcohol intake, body mass index (BMI), and age, smoking had the greatest influence and was shown to be an independent risk factor for dyslipidemia.

[Cloning and sequencing of the maize ribosome-inactivating protein gene]

A gene encoding maize Ribosome-inactivating protein was amplified by means of PCR using mRNA of maize leaves as a template, and cloned into pUC19 vector. The amplified DNA sequence has been determined, which consists of 828 bp and encodes 275 amino acid residues. Comparison with previously reported sequence shows 98.4% homologies in nucleotide sequence and 97.4% in amino acid sequence, respectively.