Effects of Foliar Spraying of Dicarboxylicdimethylammonium Chloride on Cadmium and Arsenic Accumulation in Rice Grains.

A field experiment with double cropping rice was carried out to study the foliar application effects of dicarboxylicdimethylammonium chloride (DDAC) on cadmium (Cd) and arsenic (As) accumulation in rice grains. The results showed that the spraying of DDAC could significantly reduce the accumulation of Cd and As in rice grains. The highest reductions in Cd and As content were observed when 1.5 mmol L-1 DDAC was sprayed, with 49.1% and 27.4% reductions in Cd and As content in early rice grains and 56.5% and 28.1% reductions in Cd and As content in late rice grains, respectively. In addition, the content of calcium (Ca) in rice grains increased significantly after DDAC foliar application, which was also conducive to the synthesis of amino acids such as glutamate (Glu), glycine (Gly) and cysteine (Cys) in rice grains. The results indicated that the foliar spraying of DDAC can inhibit the absorption, transport, accumulation and toxicity of Cd and As in rice grains by increasing amino acid synthesis and regulating the absorption and transport of essential elements.

Precisely Regulating Intermolecular Interactions and Molecular Packing of Nonfused-Ring Electron Acceptors via Halogen Transposition for High-Performance Organic Solar Cells.

The structure of molecular aggregates is crucial for charge transport and photovoltaic performance in organic solar cells (OSCs). Herein, the intermolecular interactions and aggregated structures of nonfused-ring electron acceptors (NFREAs) are precisely regulated through a halogen transposition strategy, resulting in a noteworthy transformation from a 2D-layered structure to a 3D-interconnected packing network. Based on the 3D electron transport pathway, the binary and ternary devices deliver outstanding power conversion efficiencies (PCEs) of 17.46% and 18.24%, respectively, marking the highest value for NFREA-based OSCs.

Efficient regulation of cadmium accumulation by carboxymethylammonium chloride in rice: Correlation analysis and expression of transporter gene OsGLR3.

The mechanism of carboxymethylammonium chloride (CC) regulating cadmium (Cd) accumulation in rice was studied in field and hydroponic experiments. Field experiments showed that 0.2-1.2 mmol L-1 CC spraying effectively reduced Cd accumulation by 44 %-77 % in early rice grains and 39 %-78 % in late rice grains, significantly increased calcium (Ca) content and amino acids content in grains, as well as alleviated Cd-induced oxidative damage in leaves. Hydroponic experiments further verified the inhibition effect of CC on Cd accumulation. 1.2 mmol L-1 CC made the highest decrease of Cd content in shoots and roots of hydroponic seedlings by 45 % and 53 %, respectively. Exogenous CC significantly increased glutamate (Glu), glycine (Gly) and glutathione (GSH) content, and improved the activities of catalase (CAT) and superoxide dismutase (SOD) by 41-131 % and 11-121 % in shoots of hydroponic seedlings, respectively. Exogenous CC also increased the relative expression of OsGLR3.1-3.5 in the shoots and roots of hydroponic seedlings. The quantum computational chemistry was used to clarify that the Gly radical provided by CC could form various complexes with Cd through carboxyl oxygen atoms. These results showed that exogenous application of CC improved the tolerance to Cd by enhancing the antioxidant capacity; inhibited the absorption, transport and accumulation of Cd in rice by (1) promoting chelation, (2) increasing the GLRs activity through upregulating the content of Glu, Gly, as well as the expression of OsGLR3.1-3.5.

Recent Advances of Benzodithiophene-Based Donor Materials for Organic Solar Cells.

Recently, the power conversion efficiency (PCE) of organic solar cells (OSCs) has increased dramatically, making a big step toward the industrial application of OSCs. Among numerous OSCs, benzodithiophene (BDT)-based OSCs stand out in achieving efficient PCE. Notably, single-junction OSCs using BDT-based polymers as donor materials have completed a PCE of over 19%, indicating a dramatic potential for preparing high-performance large-scale OSCs. This paper reviews the recent progress of OSCs based on BDT polymer donor materials (PDMs). The development of BDT-based OSCs is concisely summarized. Meanwhile, the relationship between the structure of PDMs and the performance of OSCs is further described in this review. Besides, the development and prospect of single junction OSCs are also discussed.

Regulating the Sequence Structure of Conjugated Block Copolymers Enables Large-Area Single-Component Organic Solar Cells with High Efficiency and Stability.

Single-component organic solar cells (SCOSCs) based on conjugated block copolymers (CBCs) by covalently bonding a polymer donor and polymer acceptor become more and more appealing due to the formation of a favorable and stable morphology. Unfortunately, a deep understanding of the effect of the assembly behavior caused by the sequence structure of CBCs on the device performance is still missing. Herein, from the aspect of manipulating the sequence length and distribution regularity of CBCs, we synthesized a series of new CBCs, namely D18(20)-b-PYIT, D18(40)-b-PYIT and D18(60)-b-PYIT by two-pot polymerization, and D18(40)-b-PYIT(r) by traditional one-pot method. It is observed that precise manipulation of sequence length and distribution regularity of the polymer blocks fine-tunes the self-assembly of the CBCs, optimizes film morphology, improves optoelectronic properties, and reduces energy loss, leading to simultaneously improved efficiency and stability. Among these CBCs, the D18(40)-b-PYIT-based device achieves a high efficiency of 13.4 % with enhanced stability, which is an outstanding performance among SCOSCs. Importantly, the regular sequence distribution and suitable sequence length of the CBCs enable a facile film-forming process of the printed device. For the first time, the blade-coated large-area rigid/flexible SCOSCs are fabricated, delivering an impressive efficiency of 11.62 %/10.73 %, much higher than their corresponding binary devices.

Viral infection dynamics with mitosis, intracellular delays and immune response.

In this paper, we propose a delayed viral infection model with mitosis of uninfected target cells, two infection modes (virus-to-cell transmission and cell-to-cell transmission), and immune response. The model involves intracellular delays during the processes of viral infection, viral production, and CTLs recruitment. We verify that the threshold dynamics are determined by the basic reproduction number $ R_0 $ for infection and the basic reproduction number $ R_{IM} $ for immune response. The model dynamics become very rich when $ R_{IM} > 1 $. In this case, we use the CTLs recruitment delay $ \tau_3 $ as the bifurcation parameter to obtain stability switches on the positive equilibrium and global Hopf bifurcation diagrams for the model system. This allows us to show that $ \tau_3 $ can lead to multiple stability switches, the coexistence of multiple stable periodic solutions, and even chaos. A brief simulation of two-parameter bifurcation analysis indicates that both the CTLs recruitment delay $ \tau_3 $ and the mitosis rate $ r $ have a strong impact on the viral dynamics, but they do behave differently.

Effects of Exogenous Chlorinated Amino Acetic Acid on Cadmium and Mineral Elements in Rice Seedlings.

To explore the effect of exogenous application of chlorinated amino acetic acid on cadmium (Cd) transport characteristics in rice seedlings, X24 and Z35 rice were taken as the research objects to carry out hydroponics experiments, and the changes of Cd content in rice seedlings, rice mineral elements and amino acid content in rice were analyzed. The results showed that exogenous application of 1.2 mmol·L-1 chlorinated amino acetic acid inhibited cadmium in shoots and roots of rice seedlings; Cd content in shoots and roots were reduced by up to 62.19% and 45.61%, respectively. The majority of cadmium was in the cell wall of shoots and roots; this decreased with the increase of the concentration of chlorinated acetic acid. In addition, the Mn content in shoots and Ca content in roots of rice seedlings increased significantly after the application of chlorinated amino acetic acid. The results of amino acid analysis showed that the contents of aspartic acid, glutamic acid and cystine in rice seedlings were increased. These results indicate that exogenous application of chlorinated amino acetic acid is beneficial to the synthesis of aspartic acid, glutamic acid and cysteine in rice seedlings, increases the content of Mn in shoots and Ca in roots of rice seedlings, and significantly alleviates cadmium stress in seedlings. This provides a theoretical basis for the development of an environmentally friendly Cd-lowering foliar fertilizer for rice.

Viral dynamics with immune responses: effects of distributed delays and Filippov antiretroviral therapy.

In this paper, we propose a general viral infection model to incorporate two infection modes (virus-to-cell mode and cell-to-cell mode), the CTL immune response, and the distributed intracellular delays during the processes of viral infection, viral production, and CTLs recruitment. We investigate the existence, the uniqueness, and the global stability of three equilibria: infection-free equilibrium [Formula: see text], immune-inactivated equilibrium [Formula: see text] and immune-activated equilibrium [Formula: see text], respectively. We prove that the viral dynamics are determined by two threshold parameters: the basic reproduction number for infection [Formula: see text] and the basic reproduction number for immune response [Formula: see text]. We also numerically explore the viral dynamics beyond stability. We use bifurcation diagrams to show that increasing the delay in CTL immune cell recruitment can induce a switch in viral load from a stable constant level to sustained oscillations, and then back to a stable equilibrium. We also compare the contributions of the two infection modes to the total infection level and identify the key parameters that would affect the percentages of virus-to-cell infection and cell-to-cell infection. Finally, we explore how Filippov control can be applied in antiretroviral therapy to reduce the viral loads.

Regulation of Polymer Configurations Enables Green Solvent-Processed Large-Area Binary All-Polymer Solar Cells With Breakthrough Performance and High Efficiency Stretchability Factor.

With the great potential of the all-polymer solar cells for large-area wearable devices, both large-area device efficiency and mechanical flexibility are very critical but attract limited attention. In this work, from the perspective of the polymer configurations, two types of terpolymer acceptors PYTX-A and PYTX-B (X = Cl or H) are developed. The configuration difference caused by the replacement of non-conjugated units results in distinct photovoltaic performance and mechanical flexibility. Benefiting from a good match between the intrinsically slow film-forming of the active materials and the technically slow film-forming of the blade-coating process, the toluene-processed large-area (1.21 cm2 ) binary device achieves a record efficiency of 14.70%. More importantly, a new parameter of efficiency stretchability factor (ESF) is proposed for the first time to comprehensively evaluate the overall device performance. PM6:PYTCl-A and PM6:PYTCl-B yield significantly higher ESF than PM6:PY-IT. Further blending with non-conjugated polymer donor PM6-A, the best ESF of 3.12% is achieved for PM6-A:PYTCl-A, which is among the highest comprehensive performances.

Amphiphilic Nanointerface: Inducing the Interfacial Activation for Lipase.

Graphene-based materials are widely used in the field of immobilized enzymes due to their easily tunable interfacial properties. We designed amphiphilic nanobiological interfaces between graphene oxide (GO) and lipase TL (Thermomyces lanuginosus) with tunable reduction degrees through molecular dynamics simulations and a facile chemical modulation, thus revealing the optimal interface for the interfacial activation of lipase TL and addressing the weakness of lipase TL, which exhibits weak catalytic activity due to an inconspicuous active site lid. It was demonstrated that the reduced graphene oxide (rGO) after 4 h of ascorbic acid reduction could boost the relative enzyme activity of lipase TL to reach 208%, which was 48% higher than the pristine GO and 120% higher than the rGO after 48 h of reduction. Moreover, TL-GO-4 h's tolerance against heat, organic solvent, and long-term storage environment was higher than that of free TL. The drawbacks of strong hydrophobic nanomaterials on lipase production were explored in depth with the help of molecular dynamics simulations, which explained the mechanism of enzyme activity enhancement. We demonstrated that nanomaterials with certain hydrophilicity could facilitate the lipase to undergo interfacial activation and improve its stability and protein loading rate, displaying the potential of the extensive application.

Ferroelectric Polymer Drives Performance Enhancement of Non-fullerene Organic Solar Cells.

Enhancing the built-in electric field to promote charge dynamitic process is of great significance to boost the performance of the non-fullerene organic solar cells (OSCs), which has rarely been concerned. In this work, we introduced a cheap ferroelectric polymer as an additive into the active layers of non-fullerene OSCs to improve the device performance. An additional and permanent electrical field was produced by the polarization of the ferroelectric dipoles, which can substantially enhance the built-in electric field. The promoted exciton separation, significantly accelerated charge transport, reduced the charge recombination, as well as the optimized film morphology were observed in the device, leading to a significantly improved performance of the PVDF-modified OSCs with various active layers, such as PM6 : Y6, PM6 : BTP-eC9, PM6 : IT-4F and PTB7-Th : Y6. Especially, a record efficiency of 17.72 % for PM6 : Y6-based OSC and an outstanding efficiency of 18.17 % for PM6 : BTP-eC9-based OSC were achieved.

Random Copolymerization Strategy for Host Polymer Donor PM6 Enables Improved Efficiency Both in Binary and Ternary Organic Solar Cells.

Although breakthroughs have been made in organic solar cells (OSCs) in recent years, the power conversion efficiency (PCE) of OSCs still lags behind inorganic/perovskite solar cells. In this work, two terpolymers were synthesized by introducing the thieno[3,4-c]pyrrole-4,6-(5H)-dione (TPD) block into the host polymer donor PM6. Owing to the lower highest occupied molecular orbital energy level, wider light absorption, optimal molecular packing, and more desirable aggregation morphology by addition of the TPD, the PM6-TPD-5 % : Y6-based device displayed an improved PCE of 16.3 % with an enhanced open-circuit voltage (VOC ) of 0.860 V, relative to that of PM6-TPD-10 % : Y6 (PCE=14.8 %) and PM6 : Y6-based device (PCE=15.6 %). Interestingly, the VOC did not always increase in proportion to the third component. Besides, ternary OSCs based on PM6 : PM6-TPD-5 % : Y6 achieved a superior PCE of 17.1 %. This work demonstrated that random copolymerization is a feasible and effective strategy to further increase device performance, and the two polymers that possess similar structure and absorption in ternary devices can also obtain impressive efficiency.

Joint impacts of media, vaccination and treatment on an epidemic Filippov model with application to COVID-19.

A non-smooth SIR Filippov system is proposed to investigate the impacts of three control strategies (media coverage, vaccination and treatment) on the spread of an infectious disease. We synthetically consider both the number of infected population and its changing rate as the switching condition to implement the curing measures. By using the properties of the Lambert W function, we convert the proposed switching condition to a threshold value related to the susceptible population. The classical epidemic model involving media coverage, linear functions describing injecting vaccine and treatment strategies is examined when the susceptible population exceeds the threshold value. In addition, we consider another SIR model accompanied with the vaccination and treatment strategies represented by saturation functions when the susceptible population is smaller than the threshold value. The dynamics of these two subsystems and the sliding domain are discussed in detail. Four types of local sliding bifurcation are investigated, including boundary focus, boundary node, boundary saddle and boundary saddle-node bifurcations. In the meantime, the global bifurcation involving the appearance of limit cycles is examined, including touching bifurcation, homoclinic bifurcation to the pseudo-saddle and crossing bifurcation. Furthermore, the influence of some key parameters related to the three treatment strategies is explored. We also validate our model by the epidemic data sets of A/H1N1 and COVID-19, which can be employed to reveal the effects of media report and existing strategy related to the control of emerging infectious diseases on the variations of confirmed cases.

Crumpling-origami transition for twisting cylindrical shells.

Origami and crumpling are two processes to reduce the size of a membrane. In the shrink-expand process, the crease pattern of the former is ordered and protected by its topological mechanism, while that of the latter is disordered and generated randomly. We observe a morphological transition between origami and crumpling states in a twisted cylindrical shell. By studying the regularity of the crease pattern, acoustic emission, and energetics from experiments and simulations, we develop a model to explain this transition from frustration of geometry that causes breaking of rotational symmetry. In contrast to solving von Kármán-Donnell equations numerically, our model allows derivations of analytic formulas that successfully describe the origami state. When generalized to truncated cones and polygonal cylinders, we explain why multiple and/or reversed crumpling-origami transitions can occur.

Porous nanocubic Mn3O4-Co3O4 composites and their application as electrochemical supercapacitors.

A simple approach has been developed to fabricate ideal supercapacitors based on porous Mn(3)O(4)-Co(3)O(4) nanocubic composite electrodes. We can easily obtain porous corner-truncated nanocubic Mn(3)O(4)-Co(3)O(4) composite nanomaterials without any subsequent complicated workup procedure for the removal of a hard template, seed or by using a soft template. In such a composite, the porous Mn(3)O(4)-Co(3)O(4) enables a fast and reversible redox reaction to improve the specific capacitance. The porous nanocubic Mn(3)O(4)-Co(3)O(4) composite electrode can effectively transport electrolytes and shorten the ion diffusion path, which offers excellent electrochemical performance. These results suggest that such porous Mn(3)O(4)-Co(3)O(4) composite nanocubes are very promising for next generation high-performance supercapacitors.