Retroperitoneal parasitic fetus: A case report.

BACKGROUND: Fetus-in-fetu (FIF) is an extremely rare congenital abnormal mass, in which a normal fetus's vertebral axis frequently connected with malformed fetus around this axis. Here, we report the case of a male infant aged 26 d presenting with retroperitoneal parasitic fetus. CASE SUMMARY: In a prenatal examination, we first detected an abdominal mass measuring 7.8 cm × 5.1 cm × 6.8 cm in a mother's abdomen at 25 gestational weeks and teratoma was suspected. After the fetal was born, we did a magnetic resonance imaging (MRI) and ultrasonography on him and saw a distinctive limb with five-toes. According to the result of MRI, ultrasonography and postoperative pathology, he finally was diagnosed with FIF. CONCLUSION: A laparotomy was performed at 26 d of age with excision of the retroperitoneal cystic tumor, which measured about 10 cm in diameter. According to the result of imaging and histological test, FIF was confirmed.

[Analysis of Chemical Components and Sources of PM2.5 During Autumn and Winter in Yangquan City].

PM2.5 samples were collected from October 15, 2017 to January 23, 2018 in the Yangquan urban area. The characteristics of PM2.5 and its main chemical components on clean and polluted days were analyzed, and source apportionment of PM2.5 was conducted using enrichment factor analysis (EF) and positive matrix factorization (PMF). The results showed that the ratios of secondary inorganic ions (SO42-, NO3-, and NH4+) to PM2.5 on polluted days was 23.83%, which is 2.43 times higher than that on clean days, indicating that secondary inorganic pollution was more significant on polluted days. The enrichment degree of anthropogenic elements Cd, Sb, Sn, Cu, Pb, Zn, and As on polluted days was higher than that on clean days. The results of the PMF source apportionment showed that the main sources of PM2.5 in Yangquan are coal combustion, dust, motor vehicles, secondary aerosols, and industry, with contributions of 29.26%, 23.83%, 19.34%, 16.01%, and 11.57%, respectively. The contribution of motor vehicle emissions to PM2.5 on polluted days is 20.57%, which is higher than that on clean days (17.82%), while the contribution of coal combustion sources to PM2.5 on polluted days is 23.04%, which is significantly lower than that on clean days (33.75%). The stationary weather on polluted days caused the contribution of motor vehicle emissions to PM2.5 to increase compared with on clean days, while the contribution of coal combustion sources to PM2.5 was decreased. The results show that air pollution control should pay more attention to the control of coal combustion and dust during autumn and winter in Yangquan, and further strengthen the control of motor vehicles to reduce their contribution to pollution.

[Characteristics, Source Apportionment, and Environmental Impact of Volatile Organic Compounds in Summer in Yangquan].

Volatile organic compounds (VOCs) were collected at three environmental sampling sites in Yangquan and quantified by gas chromatography-mass selective detector/flame ionization detector(GC-MSD/FID). The VOC sources were identified by diagnostic ratios and positive matrix factorization (PMF), and environmental impact of VOCs on O3 and secondary organic aerosol (SOA) were evaluated. The results showed that the average VOC concentration was (82.1±22.7) µg·m-3, with alkanes being the most abundant group (51.8%), followed by aromatics (17.8%), alkenes (8.0%), and alkynes (3.8%). The diurnal variation of VOCs exhibited a bimodal trend, with twin peaks appearing at 08:00-10:00 and 18:00-20:00, falling to a valley at 12:00-14:00. The results for benzene/toluene (2.1±1.3) and isopentane/n-pentane (1.7±0.6) showed that the ambient VOCs may be influenced by coal combustion and vehicular emissions. Six sources were extracted by PMF:coal combustion (34.9%), vehicle emissions (18.2%), gasoline evaporation (15.2%), industrial emissions (13.6%), biogenic emissions (9.2%), and solvent usage (9.0%). The average concentration of ozone formation potential (OFP) was 156.6 µg·m-3, with the highest contribution from alkenes, while the average concentration of secondary organic aerosol formation potential (SOAp) was 68.7 µg·m-3, mainly from aromatics (93.4%). In summary, coal combustion was the most abundant source of VOCs, and accelerating the management of coal gangue and energy structure readjustment are the key points to address. Meanwhile, restricting the VOCs from vehicle emissions, gasoline evaporation, and industrial emissions is also required.

[Stable Carbon Isotope Compositions and Source Apportionments of Volatile Aromatic Compounds in the Urban Atmosphere of Taiyuan, China].

This study used Tenax TA absorption tubes to sample volatile aromatic compounds from different emission sources and functional zones in Taiyuan City, Shanxi Province, China. Thermal desorption-gas chromatography-isotope ratio mass spectrometry (TD-GC-IRMS) was subsequently employed to analyze the stable carbon isotope characteristics of the volatile aromatic compounds. The results revealed that the stable carbon isotope ratio (δ13C) of the volatile aromatic compounds emitted through diesel, gasoline, and solvent volatilization, vehicle exhaust, and domestic coal combustion ranged from (-30.79±0.98)‰ to (-29.10±0.14)‰, (-30.96±0.88)‰ to (-28.02±1.77)‰, (-32.13±0.59)‰ to (-27.67±0.49)‰, (-27.58±0.16)‰ to (-25.50±0.75)‰, and (-25.14±0.93)‰ to (-23.44±1.32)‰, respectively. The δ13C value of styrene was (-23.44±1.32)‰, which was only detected in the fumes emitted through domestic coal combustion. Additionally, the sample analysis based on data collected from four different functional zones of Taiyuan City revealed the following:① the δ13C values of the atmospheric volatile aromatic compounds in the mixed residential and traffic zone ranged from (-25.61±2.20)‰ to (-23.91±0.78)‰. Compared with other functional zones, the emissions in this zone were enriched with13C; and ② the δ13C values measured in the industrial zone ranged from (-29.15±1.06)‰ to (-24.53±1.07)‰; the emissions in this functional zone were relatively low in 13C compared with other zones. A comparison of the δ13C values of the atmospheric volatile aromatic compounds and emission sources indicated that the main sources of volatile aromatic compounds at the four sampling points in Taiyuan were vehicle exhausts and domestic coal combustion, while the air sampled in the industrial functional zone was heavily affected by the volatilization of solvents.

[Characteristics and Source Apportionment of Ambient Volatile Organic Compounds in Winter in Jincheng].

Air samples were collected and analyzed by GC-MS to investigate the component characteristics of volatile organic compounds (VOCs) in winter in Jincheng. PMF, ratio analysis, and the backward trajectory model were used to investigate sources of VOCs. Ozone formation potential and secondary organic aerosol formation potential were calculated, in order to analyze the environmental implications of detected VOCs. Results showed that the average concentration of VOCs was 93.35 µg·m-3 in Jincheng, with the most abundant component being alkane (52.91 µg·m-3 and 56.68% of total VOCs). Based on PMF analysis, five sources of ambient VOCs in Jincheng were identified, namely industrial emission sources (33.71%), fuel combustion sources (30.27%), vehicle emissions (26.28%), solvent evaporation sources (9.00%), and plant emission sources (0.74%). Ratios of B/T and i-pentane/n-pentane were 1.58±0.68 and 2.07±0.43, indicating that VOCs were derived from the mixture of road and coal combustion sources. Clustered analysis of the air mass backward trajectory showed that three air masses cluster, which were accounting for 50%, 25% and 25% of the total back trajectories respectively, all came from the northwest, and industrial pollution from the northwest might therefore significantly influence VOCs in Jincheng. With low wind speed (<3 m·s-1), the air quality index, concentration of total VOCs, and contribution rate of vehicle emissions were 143, 162.48 µg·m-3, and 46.16%, respectively, higher than values at faster wind speeds (3-6.9 m·s-1). Ozone formation potential and secondary organic aerosol formation potential of aromatic hydrocarbons, which had the highest formation potential, were 98.89 µg·m-3 and 1.21 µg·m-3, respectively, accounting for 37.28% and 97.01% of total formation potential. To reduce the pollution of VOCs in Jincheng, it is important to control industrial emissions, vehicle emissions, and fuel combustion emissions.

RNA interference-mediated knockdown of the hydroxyacid-oxoacid transhydrogenase gene decreases thiamethoxam resistance in adults of the whitefly Bemisia tabaci.

Bemisia tabaci has developed a high level of resistance to thiamethoxam, a second generation neonicotinoid insecticide that has been widely used to control this pest. In this study, we investigated whether hydroxyacid-oxoacid transhydrogenase (HOT) is involved in resistance to the neonicotinoid insecticide thiamethoxam in the whitefly. We cloned the full-length gene that encodes HOT in B. tabaci. Its cDNA contains a 1428-bp open reading frame encoding 475 amino acid residues. Then we evaluated the mRNA expression level of HOT in different developmental stages, and found HOT expression was significantly greater in thiamethoxam resistance adults than in thiamethoxam susceptible adults. Subsequently, seven field populations of B. tabaci adults were sampled, the expression of mRNA level of HOT significant positive correlated with thiamethoxam resistance level. At last, we used a modified gene silencing system to knock-down HOT expression in B. tabaci adults. The results showed that the HOT mRNA levels decreased by 57% and thiamethoxam resistance decreased significantly after 2 days of feeding on a diet containing HOT dsRNA. The results indicated that down-regulation of HOT expression decreases thiamethoxam resistance in B. tabaci adults.

[Chemical Compositions and Source Apportionment of Road Dust in Yuncheng].

Samples of particulate sources in Yuncheng including road dust, salt lake dust, coal dust, soil dust, construction,cement dust and vehicle exhaust dust were collected. Elements, ions and carbon species in particulate sources samples were analyzed. Enrichment factors and potential ecological risk assessment were used to analyze the characteristics of road dust, and chemical mass balance model was applied to identify the source of road dust. The results showed that, compared with other cities, the proportions of Na(12.1970%) and SO42-(8.5971%) were relatively high while that of Si(9.1123%) was low in road dust in Yuncheng, and enrichment factors showed that the sources of Pb, Cu, Cr, V, As, Ni, Na and Zn in road dust were obviously influenced by human activities; the potential ecological risk of heavy metals in road dust was high, which was affected by anthropogenic sources such as industrial production, the combustion of fossil fuels and vehicle exhaust; the profiles of coal dust, vehicle exhaust dust, construction and cement dust were similar to those of other cities, the Na and SO42- concentrations in soil dust were relatively high, and the proportions of Na and SO42- in salt lake dust were 30.3% and 22.7% respectively; salt lake dust was the largest contributor (53%) to road dust, followed by the soil dust (21%), vehicle exhaust dust (8%), construction and cement dust (7%), and coal dust (5%).

Two cytochrome P450 genes are involved in imidacloprid resistance in field populations of the whitefly, Bemisia tabaci, in China.

The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is an invasive and damaging pest of field crops worldwide. The neonicotinoid insecticide imidacloprid has been widely used to control this pest. We assessed the species composition (B vs. Q), imidacloprid resistance, and association between imidacloprid resistance and the expression of five P450 genes for 14-17 B. tabaci populations in 12 provinces in China. Fifteen of 17 populations contained only B. tabaci Q, and two populations contained both B and Q. Seven of 17 populations exhibited moderate to high resistance to imidacloprid, and eight populations exhibited low resistance to imidacloprid, compared with the most susceptible field WHHB population. In a study of 14 of the populations, resistance level was correlated with the expression of the P450 genes CYP6CM1 and CYP4C64 but not with the expression of CYP6CX1, CYP6CX4, or CYP6DZ7. This study indicates that B. tabaci Q has a wider distribution in China than previously reported. Resistance to imidacloprid in field populations of B. tabaci is associated with the increased expression of two cytochrome P450 genes (CYP6CM1 and CYP4C64).

Gene expression profiling in the thiamethoxam resistant and susceptible B-biotype sweetpotato whitefly, Bemisia tabaci.

Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library. To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females.

Pyrosequencing the Bemisia tabaci transcriptome reveals a highly diverse bacterial community and a robust system for insecticide resistance.

BACKGROUND: Bemisia tabaci (Gennadius) is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes. METHODOLOGY AND PRINCIPAL FINDINGS: Using Roche 454 pyrosequencing, 857,205 reads containing approximately 340 megabases were obtained from the B. tabaci transcriptome. De novo assembly generated 178,669 unigenes including 30,980 from insects, 17,881 from bacteria, and 129,808 from the nohit. A total of 50,835 (28.45%) unigenes showed similarity to the non-redundant database in GenBank with a cut-off E-value of 10-5. Among them, 40,611 unigenes were assigned to one or more GO terms and 6,917 unigenes were assigned to 288 known pathways. De novo metatranscriptome analysis revealed highly diverse bacterial symbionts in B. tabaci, and demonstrated the host-symbiont cooperation in amino acid production. In-depth transcriptome analysis indentified putative molecular markers, and genes potentially involved in insecticide resistance and nutrient digestion. The utility of this transcriptome was validated by a thiamethoxam resistance study, in which annotated cytochrome P450 genes were significantly overexpressed in the resistant B. tabaci in comparison to its susceptible counterparts. CONCLUSIONS: This transcriptome/metatranscriptome analysis sheds light on the molecular understanding of symbiosis and insecticide resistance in an agriculturally important phloem-feeding insect pest, and lays the foundation for future functional genomics research of the B. tabaci complex. Moreover, current pyrosequencing effort greatly enriched the existing whitefly EST database, and makes RNAseq a viable option for future genomic analysis.