Quantification of Central and Eastern China's atmospheric CH4 enhancement changes and its contributions based on machine learning approach.

Methane is the second largest anthropogenic greenhouse gas, and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks. Therefore, the monitoring of CH4 concentration changes and the assessment of underlying driving factors can provide scientific basis for the government's policy making and evaluation. China is the world's largest emitter of anthropogenic methane. However, due to the lack of ground-based observation sites, little work has been done on the spatial-temporal variations for the past decades and influencing factors in China, especially for areas with high anthropogenic emissions as Central and Eastern China. Here to quantify atmospheric CH4 enhancements trends and its driving factors in Central and Eastern China, we combined the most up-to-date TROPOMI satellite-based column CH4 (xCH4) concentration from 2018 to 2022, anthropogenic and natural emissions, and a random forest-based machine learning approach, to simulate atmospheric xCH4 enhancements from 2001 to 2018. The results showed that (1) the random forest model was able to accurately establish the relationship between emission sources and xCH4 enhancement with a correlation coefficient (R²) of 0.89 and a root mean-square error (RMSE) of 11.98 ppb; (2)The xCH4 enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018, with a relative change of 3.27%±0.13%; (3) The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH4 enhancement, contributing 68.00% and 31.21%, respectively, and the decrease of animal ruminants contributed -6.70% of its enhancement trend.

Toxic effects of maternal cadmium exposure on the metabolism and transport system of amino acids in the maternal livers.

Fetal growth restriction (FGR) is one of the most common obstetric diseases, and affects approximately 10 % of all pregnancies worldwide. Maternal cadmium (Cd) exposure is one of the factors that may increase the risk of the development of FGR. However, its underlying mechanisms remain largely unknown. In this study, using Cd-treated mice as an experimental model, we analyzed the levels of some nutrients in the circulation and the fetal livers by biochemical assays; the expression patterns of several key genes involved in the nutrient uptake and transport, and the metabolic changes in the maternal livers were also examined by quantitative real-time PCR and gas chromatography-time of flight-mass spectrometry method. Our results showed that, the Cd treatment specifically reduced the levels of total amino acids in the peripheral circulation and the fetal livers. Concomitantly, Cd upregulated the expressions of three amino acid transport genes (SNAT4, SNAT7 and ASCT1) in the maternal livers. The metabolic profiling of maternal livers also revealed that, several amino acids and their derivatives were also increased in response to the Cd treatment. Further bioinformatics analysis indicated that the experimental treatment activated the metabolic pathways, including the alanine, aspartate and glutamate metabolism, valine, leucine and isoleucine biosynthesis, arginine and proline metabolism. These findings suggest that maternal Cd exposure activate the amino acid metabolism and increase the amino acid uptake in the maternal liver, which reduces the supply of amino acids to the fetus via the circulation. We suspect that this underlies the Cd-evoked FGR.

Successful Treatment of Severe Community-Acquired Pneumonia caused by Chlamydia Psittaci: a Case Report.

BACKGROUND: Community acquired pneumonia is a common and deadly condition, which remains a major cause of morbidity and mortality throughout the world. Chlamydia psittaci pneumonia is responsible for less than 5% of community-acquired pneumonia with a fatality rate of 1%. Nonetheless, it is underestimated due to low awareness of the disease and atypical clinical presentation in a majority of the cases. Metagenomic next-generation sequencing can help us diagnose and clarify the etiology in time. METHODS: We reported a case of an 85-year-old man who presented with intermittent fever and cough with wheezing for 4 days and did a review of related literature. RESULTS: The patient was admitted to our department due to severe CAP and multiple organ dysfunction. After admission, we applied an empirical antibiotic strategy, performed intubation and invasive ventilation, fluid resuscitation, vasoactive drugs and supportive care. On the third day of admission, metagenomic next-generation sequencing results of blood and bronchoalveolar lavage fluid suggested Chlamydia psittaci. We made a diagnosis of sever Chlamydia psittaci pneumonia and adjusted antibiotics to minocycline combined with azithromycin two days after admission. The patient was successfully cured with a good prognosis. CONCLUSIONS: Detecting the pathogen as early as possible and achieving accurate diagnosis are essential in infected patients. We can benefit from careful application of metagenomic next-generation sequencing.

UV-Triggered Surface-Initiated Polymerization from Colorless Green Tea Polyphenol-Coated Surfaces.

A facile and versatile approach to constructing colorless surface coatings based on green tea polyphenols is reported, which can further act as a photoinitiating layer to initiate radical polymerization. These colorless green tea polyphenol coatings are capable of successfully photografting polymer brushes, and the resulting polymer brush patterns show spatial shape adjustability by masked UV irradiation. Both surface modifications and photografted polymer brushes do not alter the original color of the substrates. This method could be promising for the development of surface modifications.

Competitive self-assembly driven as a route to control the morphology of poly(tannic acid) assemblies.

With an attempt to develop some supermolecular assemblies of a particular structure through a controllable method, the present study developed two distinct assembly patterns for Poly(Tannic Acid) (PTA) by means of adjusting the components and composition of a binary solvent system. The assembly mechanism was explored through the comparison of theoretical calculations and experimental results with respect to how solvent sets affect the nature of intermolecular interactions among oligomers. The results indicate that the morphology of the aggregates of PTA is determined from the nature of the intermolecular interactions among oligomers. While a cuboid shaped aggregate is likely the result of π-π stacking self-assembly, a sphere shaped morphology is formed through intermolecular hydrogen bonding among the oligomers. The results of the present work provide valuable resources to tune the aggregation morphology by quantitatively adjusting the physical properties of the binary solvent.

A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.

A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.