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In this paper, a sequence of passive micromixers with spiral patterns on the side wall of cylindrical chambers are designed, optimized, prepared and tested. The simulation studies show that the vortex magnitude and continuity in the mixing chamber are the most important factors to determine mixing performance, while the inlet position and structural parameters are secondary influences on their performance. According to the above principles, the performance of a micromixer with a continuous sidewall spiral finally wins out. The total mixing length is only 14 mm, but when Re = 5, the mixing index can reach 99.81%. The multi-view visual tests of these mixer chips prepared by 3D printing are consistent with the simulation results. This paper provides a new idea for optimizing the micromixer with spiral patterns on the side wall and the problems of floor area and pressure loss are significantly improved compared to the conventional spiral structure.

A zoned strategy based on the spatial heterogeneity of water pollutant emissions is helpful for water environment management. With principal component analysis and clustering analysis, 31 provincial administrative regions (not including Hong Kong, Macao, and Taiwan regions) of China with emissions of 12 kinds of water quality indicators had been categorized into 4 zone type regions. Zone type-1 is the largest emissions of heavy metals, including mining-developed provinces of Hunan and Jiangxi. Zone type-2 is constituted of economically and agriculturally developed with large COD, NH4+-N, TP, and TN emissions, including Hebei, Jiangsu and Zhejiang, Anhui, Shandong, Henan, Hubei, Guangdong, and Sichuan. Zone type-3 only contains Shanxi with massive oil and volatile phenol emissions. Zone type-4 is the other 19 provinces with small discharges of water pollutants. Zone type-4 could be divided into three subclasses which are related to the location of these areas. With these cluster zones, the targeted water pollutant emissions strategy has been put forward in the paper. These methods and ideas of this paper can be further applied to the analysis of spatial and temporal differentiation of pollutant discharges in basins. With the zoning regions, more concrete water pollution prevention and control strategies can be set at a national level.

Background Congenital heart defects (CHDs) are the most common birth defect around the world. Maternal prepregnancy obesity has been proposed as a risk factor of CHDs, but the relationship of CHD risk with over- and underweight is controversial, especially because body mass index (BMI) distribution differs between Asia and the West. The study aimed to examine the potential associations of maternal over- and underweight on risk of offspring CHDs. Methods An ambispective observational study involving 1206 fetuses with CHDs and 1112 fetuses without defects at seven hospitals in China was conducted. Standardized questionnaires were used to collect information on maternal prepregnancy weight and height, social demographic characteristics, living and occupational environments, and lifestyle behaviors. Univariate, multivariate and multilevel logistic regression as well as unrestricted cubic spline analysis were used to examine potential associations of prepregnancy BMI and offspring CHDs. Results Prepregnancy maternal underweight (BMI Conclusions Our findings suggest that underweight or low average BMI may be associated with higher risk of CHDs in offspring. Health professionals may wish to advise women planning to be pregnant to maintain or even gain weight to ensure adequate, balanced nutrition and thereby reduce the risk of CHDs in their offspring.

Pollutant source apportionment is of great significance for water environmental protection. However, it is still challenging to accurately quantify pollutant loads at basin-scale. Refined analytical methods combined the pollution discharge coefficient method (PDCM), field observation, and numerical model (Soil & Water Assessment Tool, SWAT) to make quantitative source appointment in the Tuojiang River, a key tributary of the upper Yangtze River. The chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen (N-NH4+) were analyzed. Results showed that the urban sewage treatment plant point source has the largest contribution to COD, TN, and N-NH4+, while TP is mostly from the agricultural sources throughout the year. The total inflowing loads of pollution sources are significantly affected by rainfall. The overall pollution characteristics showed that pollutant loads present in different seasons are as follows: wet season > normal season > dry season. The month with the highest levels of pollutants is July in the wet season. Among the nine cities, the city that contributes the most COD, TN and N-NH4+, is Neijiang, accounting for about 25%, and the city that contributes the most TP is Deyang, accounting for 23%. Among the sub-basins, the Fuxi River subbasin and Qiuxihe River subbasin contribute the most pollutant loads. The technical framework adopted in this paper can be used to accurately identify the types, administrative regions and sub-basins of the main pollution sources in the watershed, which is conducive to management and governance of the environment.

Objective To examine whether maternal hair or cord blood selenium levels are associated with infant congenital heart defects (CHDs). Method A hospital-based case-control study was performed with samples collected from 2010 to 2014. Selenium levels in maternal hair and fetal cord serum were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Data from medical records of infants with CHDs were collected. Logistic regression analysis was employed to examine the independent association between maternal selenium exposure and fetal CHD. Results In total, 888 pregnant women were included in this study. Median (interquartile range) selenium levels in of maternal hair was similar in the control and CHD group. A significant association was detected between increased maternal hair selenium concentration and CHDs in offspring (adjusted odds ratio [aOR] 3.57, 95 %CI, 1.90-6.70). The association was present in all CHD groups, including septal defects, conotruncal defects, left ventricular outflow tract obstruction, right ventricular outflow tract obstruction, and anomalous pulmonary venous return. Conclusion High maternal selenium level is significantly associated with the occurrence of fetal CHD.

To describe the prenatal ultrasonographic characteristics and perinatal outcomes of congenital cataract. We analyzed congenital cataract diagnosed prenatally at four referral centers between August 2004 and February 2019. The diagnosis was confirmed by postnatal ophthalmologic evaluation of liveborn infants or autopsy for terminated cases. Maternal demographics, genetic testing results, prenatal ultrasound images, and perinatal outcomes were abstracted. Total of 41 cases of congenital cataract diagnosed prenatally among 788 751 women undergoing anatomic survey. Based on the sonographic characteristics, 16/41 (39.0 %) had a dense echogenic structure, 15/41 (36.6 %) had a hyperechogenic spot and 10/41 (24.4 %) had the "double ring" sign. 17/41 (41.5 %) were isolated, and 24/41 (58.5 %) had associated intraocular and extraocular findings. Microphthalmia, cardiac abnormalities, and central nervous system abnormalities were the most common associated abnormalities. Regarding potential etiology, 6 cases had a known family history of congenital cataract, 4 cases had confirmed congenital rubella infection, and 2 cases had aneuploidy. 31/41 (75.6 %) elected termination and 10/41 (24.4 %) elected to continue their pregnancy. Among the 10 cases, one case died, one case was lost to follow-up, and the remaining 8 cases were referred for ophthalmologist follow-up and postnatal surgery. Once fetal cataracts are detected, a detailed fetal anatomy survey to rule out associated abnormalities and a workup to identify the potential etiology are recommended. Prenatal diagnosis of congenital cataracts provides vital information for counseling and subsequent management.ZIEL: Beschreibung der Merkmale im pränatalen Ultraschall und des perinatalen Outcomes bei angeborenem Katarakt. Wir analysierten Fälle mit angeborenem Katarakt, die zwischen August 2004 und Februar 2019 an 4 Zentren überwiesen und pränatal diagnostiziert wurden. Die Diagnose wurde postnatal durch eine augenärztliche Untersuchung des Lebendgeborenen oder im Falle einer Interruptio durch Autopsie bestätigt. Die demografischen Daten der Mutter, genetische Untersuchungsergebnisse, pränatale Ultraschallbilder und das perinatale Outcome wurden analysiert. Insgesamt 41 Fälle von angeborenem Katarakt, die bei 788 751 Frauen im Rahmen einer anatomischen Untersuchung des Fötus diagnostiziert wurden. Basierend auf den sonografischen Merkmalen zeigten 16/41 (39,0 %) eine dichte echogene Struktur, 15/41 (36,6 %) einen hyperechogenen Fleck und 10/41 (24,4 %) das „Doppelring“ -Zeichen. Isolierte Merkmale fanden sich bei 17/41 (41,5 %) und assoziierte intraokulare und extraokulare Befunde bei 24/41 (58,5 %). Mikrophthalmie, Anomalien des Herzens und des Zentralnervensystems waren die häufigsten assoziierten Befunde. In Bezug auf eine mögliche Ätiologie lag in 6 Fällen bereits ein familiärer angeborener Katarakt vor, in 4 Fällen wurde eine kongenitale Rötelninfektion bestätigt und 2 Fälle hatten Aneuploidie. Für einen Schwangerschaftsabbruch entschieden sich 31/41 (75,6 %) und für eine Fortsetzung der Schwangerschaft 10/41 (24,4 %). Von diesen 10 Fällen verstarb ein Kind, ein Fall ging für die Nachsorge verloren und bei den übrigen 8 Kindern wurde die augenärztliche Nachsorge und eine postnatale Operation eingeleitet. Bei Feststellung eines fetalen Katarakts wird empfohlen, die fetale Anatomie detailliert zu untersuchen, um assoziierte Anomalien auszuschließen, sowie die mögliche Ätiologie abzuklären. Die pränatale Diagnose des angeborenen Katarakts liefert wichtige Informationen für die Beratung und das weitere Management.

Background Many studies have investigated heavy metal exposure could increase the occurrence of congenital heart defects (CHDs). However, there are limited data regarding the relationship between cobalt exposure and CHD occurrence in offspring. The aim of this study was to analyze the association between cobalt exposure in mothers and the risk of CHDs in offspring. Materials and methods In order to explore the association between cobalt exposure and occurrence of congenital heart defect (CHD), a case-control study with 490 controls and 399 cases with CHDs in China were developed. The concentrations of cobalt in hair of pregnant woman and fetal placental tissue were measured and processed by a logistic regression analysis to explore the relationship between cobalt exposure and risk of CHDs. Results The median concentration of hair cobalt in the control and case group was 0.023 ng/mg and 0.033 ng/mg (aOR, 1.837; 95% CI, 1.468–2.299; P < 0.001), respectively. And the median (5–95% range) fetal placental cobalt concentrations were 19.350 ng/g and 42.500 ng/g (aOR, 2.924; 95% CI, 2.211–3.868; P < 0.001) in the control and case groups, respectively. Significant differences in the middle level of cobalt in hair were found in the different CHD subtypes, including septal defects, conotruncal defects, right ventricular outflow tract obstruction, and left ventricular outflow tract obstruction (P < 0.001). Dramatically, different cobalt concentrations in fetal placental tissue were found in all subtypes of cases with CHDs (P < 0.01). Conclusions The finding suggested that the occurrence of CHDs may be associated with cobalt exposure.

Background Report a case of hypoplastic left heart syndrome (HLHS) with endomyocardial fibroelastosis (EFE) diagnosed in the first trimester. Case presentation We detected a balloon shaped left ventricle, a narrowed reverse blood stream signal in the aortic arch and widened blood stream signals in the pulmonary artery (2.2 mm) and the ductus arteriosus when performing echocardiographic screen with transabdominal sonography in a 31-year-old pregnant woman (gravida 2, para 1) who presented to our department for routine fetal ultrasonography at 11+2 weeks’ gestation. Based on these findings, a diagnosis of HLHS with EFE was suspected. The findings from autopsy confirmed the diagnosis. Conclusion Ultrasound screening in the first trimester may be helpful in early diagnosis of HLHS.

Additional file 3. Correlation between maternal prepregnancy BMI and risk of single CHD in offspring. Odds ratios were adjusted for residence type, maternal age and educational level, maternal smoking, paternal smoking, maternal drinking, folic acid supplementation and parity. Hospital was set as a random intercept effect.

Additional file 4. Correlation between maternal prepregnancy BMI and risk of multiple CHDs in offspring. Odds ratios were adjusted for residence type, maternal age and educational level, maternal smoking, paternal smoking, maternal drinking, folic acid supplementation and parity. Hospital was set as a random intercept effect.

Additional file 2. Sensitivity analysis with a reference of BMI 22.6 ≤ BMI

Additional file 1. Sensitivity analysis with a reference of BMI 19.9 ≤ BMI

Objectives This study aimed to analyze the association between fetal lead or aluminum exposure and congenital heart disease (CHD) occurrence as well as to explore the mechanism of oxidative stress in heart development. Methods Lead and aluminum concentrations were measured by ICP-MS in umbilical serum. The oxidative stress statuses were analyzed by measuring SOD, GPx and MDA with colorimetric assays. Results Higher concentrations of Al were seen in the CHD groups compared to the controls. The risk of CHD occurrence increased markedly in the highly elevated Al group (aOR 2.08, 95%CI 1.11–3.88). With increasing Al and Pb levels, the activity of SOD decreased, and the level of MDA increased. Significantly decreased activity of SOD and GPx were found in the CHD groups (P Conclusion Fetal aluminum exposure may contribute to CHD occurrence. Oxidative stress was related to the concentration of Pb and Al, which may be involved in the occurrence of CHD.

Exploring the responsibility subject of water pollution is the foundation of ecological environmental control and protection. A water pollution sources apportionment and contribution rates analysis method based on one-dimensional model was developed. It was adopted in a typical trans-boundary river section in the sub-watershed of the Yangtze River Basin. The contribution rates of different time period and distinctive administrative regions of the section were calculated. Results show that urban living point sources contributed most to chemical oxygen demand (COD) and ammonia nitrogen (NH4±-N) followed by rural living sources. Agricultural sources are the main pollution source of total phosphorus (TP) throughout the year. Almost seven township regions in Deyang City, especially the Bajiaojing community and Xinshi Town, should be mainly responsible for water pollution. However, in different month and water periods, contribution rates change along with the precipitation variability. Sewage treatment plants and industrial enterprises contributed the most to pollutants in the dry season, but the living sources and non-point agricultural sources have bigger contribution rates in the wet season. There is a strong negative correlation between precipitation and contribution rate. Methods adopted in this paper can be used to analyze the pollution sources in the refined management of the water environment, so as to trace the main body of environmental responsibility.

High-precision and efficiently distributed discrete element models for water environment simulation are urgently needed in large-scale river network areas, but most distributed discrete element models are serially computed and need performance improving. Parallel computing and other common methods for models&rsquo, high performance have large labor costs and are complicated. We put forward a new mesh reduced method for promoting computational efficiency with grid re-organization according to the structure and algorithm characteristics of 2D and 3D numerical models. This simple and cheap method was adapted to a classical three-dimensional hydrodynamic and sediment model (ECOMSED) for model improvement and effective evaluation. Six schemes with different grids were made to investigate the performance of this method in the river network area of the Three Gorges Reservoir Basin. It showed good characteristics of simulation performance and model speed-up. We concluded that the method is viable and efficient for optimizing distributed discrete element models.