The environmental risk threshold (HC5) for Cd remediation in Chinese agricultural soils.

Given the increasing concern over Cd contamination of agricultural soils in China, reducing the availability of the toxic metal has become an important remedial strategy. However, the lack of a unified evaluation framework complicates the assessment of remediation efficiency of different practices. Here, we evaluated the general extraction method (GEM) of available Cd in nine typical soil types by comparing extraction agents, including CaCl2, EDTA, Mehlich-Ⅲ, HCl and DTPA. The safe grain concentration of different agricultural products from National Food Safety Standards Limits of Contaminants in Food (GB 2762-2022) was then applied to understand soil limited available Cd concentration based on dose-response curves. We also derived environmental risk threshold (HC5) values for Cd remediation in agricultural soils by constructing species sensitivity distribution (SSD) curves. The results showed that Mehlich-Ⅲ best predicted Cd accumulation in crops (with 76.5% of explanation of grain Cd) and was selected as the GEM of soil available Cd for subsequent analyses. The regression coefficient (R2) of dose-response curves fitting between Cd absorption in crop tissues and soil available Cd extracted by GEM based on 30 different crop species varied from 51.0% to 79.5%, and the derived limit concentration of soil available Cd based on standard GB 2762-2022 was 0.18-0.76 mg‧kg-1. An HC5 of 0.19 mg‧kg-1 was then calculated, meaning that a concentration of available Cd in agricultural soil below 0.19 mg‧kg-1 ensures that 95% of agricultural products meet the quality and safety requirements of standard GB 2762-2022. The prediction model was well verified in the field test, indicating that can correctly estimate the soil available Cd based on the content of Cd in plant. This study provides a robust scientific framework for deriving the risk threshold for Cd remediation in agricultural soils and could be quite useful for establishing soil remediation standards.

Comparative effects of pectin and hydrolyzed pectin coating as pre-frying treatments on acrylamide formation in potato chips.

This study aimed to compare the effects of pectin and hydrolyzed pectin coating as pre-frying treatments on acrylamide content and quality characteristics of fried potato chips. The hydrolyzed pectin with molecular weight (Mw) of 8.81 ± 0.49 kDa was obtained through partial degradation of pectin (Mw: 747.57 ± 6.73 kDa) using pectinase. Results showed that both pectin and hydrolyzed pectin coating significantly inhibited acrylamide formation and inhibition rates exceeded 90 %. Hydrolyzed pectin had stronger inhibitory activity against acrylamide formation than pectin, especially when the concentration of hydrolyzed pectin was >2 %, its inhibitory rate exceeded 95 %. Compared to pectin coating, hydrolyzed pectin coating endow fried potato chips with smaller browning, higher crispness, less moisture but higher oil content. Overall, hydrolyzed pectin had better application prospects than pectin in inhibiting acrylamide formation of fried potato chips.

Precision-controlled ultrafast electron microscope platforms. A case study: Multiple-order coherent phonon dynamics in 1T-TaSe2 probed at 50 fs-10 fm scales.

We report on the first detailed beam tests attesting the fundamental principle behind the development of high-current-efficiency ultrafast electron microscope systems where a radio frequency (RF) cavity is incorporated as a condenser lens in the beam delivery system. To allow for the experiment to be carried out with a sufficient resolution to probe the performance at the emittance floor, a new cascade loop RF controller system is developed to reduce the RF noise floor. Temporal resolution at 50 fs in full-width-at-half-maximum and detection sensitivity better than 1% are demonstrated on exfoliated 1T-TaSe2 system under a moderate repetition rate. To benchmark the performance, multi-terahertz edge-mode coherent phonon excitation is employed as the standard candle. The high temporal resolution and the significant visibility to very low dynamical contrast in diffraction signals via high-precision phase-space manipulation give strong support to the working principle for the new high-brightness femtosecond electron microscope systems.

Clinical Characteristics of Children Infected with SARS-CoV-2 Omicron (B.1.1.529) in China's Shanghai.

Introduction: The pandemic of SARS-CoV-2 brings great challenge and threats to humans worldwide. Multiple variants of SARS-CoV-2 tend to be epidemic, among which Omicron is highly infectious within China. The aim of this study was to analyze the clinical characteristics of children infected with SARS-CoV-2 variant B.1.1.529 (Omicron) in the Shanghai, China. Methods: We included 9378 pediatric patients diagnosed with Omicron and treated in the Shanghai International Convention and Exhibition Center between April 1, 2022 and May 31, 2022. We recorded and summarized the clinical characteristics, infectious conditions and biological features of the children infected with Omicron. Results: A total of 9355 paediatric patients were treated in isolation since Makeshift became available, including 5564 males (59.48%) and 3791 females (40.52%). More than half (55.56%) of the affected children were identified at premises screening. The number of symptomatic or asymptomatic patients was 4530 (48.42%) and 4825 (51.58%), respectively. Initial signs or symptoms in asymptomatic patients included fatigue (3582, 38.29%), cough (560, 5.99%), fever (242, 2.59%) and other (146, 1.56%). Age and number of vaccinations in paediatric patients were negatively associated with the number of days from positive to negative nucleic acid test results. Conclusion: Age and number of vaccinations were key factors influencing the conversion of nucleic acid test results in paediatric patients. Early childhood vaccination is encouraged to establish a complete immune barrier.

Autoimmune hepatitis with confluent necrosis indicates severe liver injury but responds well to standard immunosuppressive therapy.

We aimed to study the effects of different extensive confluent necrosis on complete biochemical remission, side effects of immunosuppressants, and outcomes in patients with autoimmune hepatitis (AIH). Patients with liver biopsy, receiving standard immunosuppressive therapy (IST), and regular follow-up were retrospectively recruited. Demographic and clinicopathological characteristics between Ishak confluent necrosis scores ≤4 (the non-severe AIH group) and ≥5 (the severe AIH group) were compared. The Kaplan-Meier Survival analysis, Cox regression analysis, and log-rank test were performed. Bilateral p<0.05 was considered statistical significance. One hundred and forty-two patients were enrolled, the median age was 56.0, and 83.8% were female. There were no significant differences in aminotransferases and immunological markers between the two groups. Patients in the severe AIH group had significantly worse liver synthetic function, a higher proportion of cirrhosis, and histologically a higher degree of portal inflammation, interface hepatitis, fibrosis stage, and a higher histological activity index score (all p<0.05). Patients in the severe AIH group had a lower response than the other group after four weeks (57.1% vs. 86.3%, p=0.002). However, differences in complete biochemical remission (CBR) were insignificant. Eight patients experienced end-point events. Kaplan-Meier survival analysis showed no significant difference between the two groups (p=0.343). For adverse effects of IST, patients in the severe group tended toward a higher incidence of corticosteroid adverse effects without statistical significance. Our study indicated that patients with histologically severe confluent necrosis (Ishak score≥5) had significantly worse liver synthetic function and a higher degree of liver fibrosis before IST. Compared with their counterparts, this subgroup of patients showed delayed biochemical response but eventually comparable CBRs, side effects, and long-term outcomes.

Cellular Cd2+ fluxes in roots confirm increased Cd availability to rice (Oryza sativa L.) induced by soil acidifications.

Soil acidifications become one of the main causes restricting the sustainable development of agriculture and causing issues of agricultural product safety. In order to explore the effect of different acidification on soil cadmium (Cd) availability, soil pot culture and hydroponic (soil potting solution extraction) were applied, and non-invasive micro-test technique (NMT) was combined. Here three different soil acidification processes were simulated, including direct acidification by adding sulfuric acid (AP1), acid rain acidification (AP2) by adding artificial simulated acid rain and excessive fertilization acidification by adding (NH4)2SO4 (AP3). The results showed that for direct acidification (AP1), DTPA-Cd concentration in field soils in Liaoning (S1) and Zhejiang (S2) increased by 0.167 - 0.217 mg/kg and 0.181 - 0.346 mg/kg, respectively, compared with control group. When soil pH decreased by 0.45 units in S1, the Cd content of rice stems, leaves and roots increased by 0.48 to 6.04 mg/kg and 2.58 to 12.84 mg/kg, respectively, When the pH value of soil S1 and S2 decreased by 0.20 units, the average velocity of Cd2+ at 200 µm increased by 10.03 - 33.11 pmol/cm2/sec and 21.33 -52.86 pmol/cm2/sec, respectively, and followed the order of AP3 > AP2 > AP1. In summary, different acidification measures would improve the effectiveness of Cd, under the same pH reduction condition, fertilization acidification increased Cd availability most significantly.