Tank-mix adjuvants improved spray performance and biological efficacy in rice insecticide application with unmanned aerial vehicle sprayer.

BACKGROUND: The use of unmanned aerial vehicles (UAVs) for the application of plant protection products (PPPs) in paddy fields is becoming increasingly prevalent worldwide. Despite its growing usage, UAV spraying for rice pest control faces practical challenges, including limited canopy penetration, uneven deposition, and significant spray drift. This study investigated the impact of two tank-mix adjuvants, Wonderful Rosin (Adjuvant-1) and Tiandun (Adjuvant-2), at six volume concentrations, on the spray liquid's physicochemical properties, spray drift, plant deposition, and the biological efficacy of rice insecticides using a quadrotor UAV sprayer. RESULTS: The physicochemical characteristics of the spray liquid influenced spray performance and biological efficacy. Incorporating Adjuvant-1 and Adjuvant-2 led to a decrease in surface tension and contact angle while increasing the viscosity of the spray solution. These alterations in surface tension and viscosity contributed to an optimized droplet size distribution, reduced spray drift, enhanced deposition uniformity and penetration, and improved control efficacy against the rice planthopper in UAV applications. The highest control efficacy was observed at a concentration of 0.5%, showing an improvement of 35.12% (Adjuvant-1) and 20.23% (Adjuvant-2) over applications without tank-mix adjuvant 7 days after treatment. CONCLUSION: The judicious selection of tank-mix adjuvants for UAV PPP applications can significantly enhance spray performance and biological efficacy in controlling rice insects. This study's findings offer valuable insights for integrating tank-mix adjuvants into UAV spraying applications. © 2024 Society of Chemical Industry.

Spray performance and control efficacy against pests in paddy rice by UAV-based pesticide application: effects of atomization, UAV configuration and flight velocity.

BACKGROUND: Over the past decade, unmanned aerial vehicle (UAV) sprayers have emerged as valuable tools for pesticide application across various crops. Despite their increasing usage, the impact of several factors on spray performance and control efficacy in paddy fields warrants further investigation. This study examines atomization characteristics using a UAV spray test platform. Our evaluation of field spraying performance considers three UAV models, two nozzle types, two flight velocities, and adding methylated vegetable oil adjuvant (MVOA), in comparison with the electrical knapsack sprayer (EKS). RESULTS: Atomization characteristics demonstrated consistency within the downwash airflow field, but were influenced by spray solution, nozzle type, and spray pressure. The eight-rotor UAV sprayer excelled over the quad-rotor model in terms of spray deposition across both upper and lower rice canopies. The six-rotor UAV exhibited enhanced spray deposition, droplet density, and coverage at a flight velocity of 4 m s-1 . The choice of nozzle was pivotal; the flat fan nozzle produced finer droplets with desirable deposition and coverage, whereas the air-induction nozzle created larger droplets with consistent coverage at various flight velocities. Adding MVOA improved the physicochemical properties of the spray and its performance, yielding a more uniform distribution. When compared with the EKS, UAVs showed lower deposition but comparable spray penetration. Control efficacy with the UAV sprayer was less effective against Mythimna separata but achieved 81% efficacy against Laodelphax striatellus within 7 days. CONCLUSION: This study demonstrates that UAV sprayers, particularly when combined with tank-mix adjuvants and nozzle types, can be highly effective for controlling rice pests. © 2023 Society of Chemical Industry.

Obeticholic acid protects against lithocholic acid-induced exogenous cell apoptosis during cholestatic liver injury.

AIMS: Lithocholic acid (LCA)-induced cholestasis was accompanied by the occurrence of apoptosis, which indicated that anti-apoptosis was a therapeutic strategy for primary biliary cholangitis (PBC). As an agonist of (Farnesoid X receptor) FXR, we supposed that the hepatoprotection of Obeticholic acid (OCA) against cholestatic liver injury is related to anti-apoptosis beside of the bile acids (BAs) regulation. Herein, we explored the non-metabolic regulating mechanism of OCA for resisting LCA-induced cholestatic liver injury via anti-apoptosis. MAIN METHODS: LCA-induced cholestatic liver injury mice were pretreated with OCA to evaluate its hepatoprotective effect and mechanism. Biochemical and pathological indicators were used to detect the protective effect of OCA on LCA-induced cholestatic liver injury. The bile acids (BAs) profile in serum was detected by LC-MS/MS. Hepatocyte BAs metabolism, apoptosis and inflammation related genes and proteins alteration were investigated by biochemical determination. KEY FINDINGS: OCA improved LCA-induced cholestasis and hepatic apoptosis in mice. The BA profile in serum was changed by OCA mainly manifested as a reduction of taurine-conjugated bile acids, which was due to the upregulation of FXR-related bile acid efflux transporters bile salt export pump (BSEP), multi-drug resistant associated protein 2 (MRP2), MRP3 and multi-drug resistance 3 (MDR3). Apoptosis related proteins cleaved caspase-3, cleaved caspase-8 and cleaved PARP were obviously reduced after OCA treatment. SIGNIFICANCE: OCA improved LCA-induced cholestatic liver injury via FXR-induced exogenous cell apoptosis, which will provide new evidence for the application of OCA to ameliorate PBC in clinical.

Boryl radical catalysis enables asymmetric radical cycloisomerization reactions.

The development of functionally distinct catalysts for enantioselective synthesis is a prominent yet challenging goal of synthetic chemistry. In this work, we report a family of chiral N-heterocyclic carbene (NHC)-ligated boryl radicals as catalysts that enable catalytic asymmetric radical cycloisomerization reactions. The radical catalysts can be generated from easily prepared NHC-borane complexes, and the broad availability of the chiral NHC component provides substantial benefits for stereochemical control. Mechanistic studies support a catalytic cycle comprising a sequence of boryl radical addition, hydrogen atom transfer, cyclization, and elimination of the boryl radical catalyst, wherein the chiral NHC subunit determines the enantioselectivity of the radical cyclization. This catalysis allows asymmetric construction of valuable chiral heterocyclic products from simple starting materials.

Genome-wide association mapping for yield-related traits in soybean (Glycine max) under well-watered and drought-stressed conditions.

Soybean (Glycine max) productivity is significantly reduced by drought stress. Breeders are aiming to improve soybean grain yields both under well-watered (WW) and drought-stressed (DS) conditions, however, little is known about the genetic architecture of yield-related traits. Here, a panel of 188 soybean germplasm was used in a genome wide association study (GWAS) to identify single nucleotide polymorphism (SNP) markers linked to yield-related traits including pod number per plant (PN), biomass per plant (BM) and seed weight per plant (SW). The SLAF-seq genotyping was conducted on the population and three phenotype traits were examined in WW and DS conditions in four environments. Based on best linear unbiased prediction (BLUP) data and individual environmental analyses, 39 SNPs were significantly associated with three soybean traits under two conditions, which were tagged to 26 genomic regions by linkage disequilibrium (LD) analysis. Of these, six QTLs qPN-WW19.1, qPN-DS8.8, qBM-WW1, qBM-DS17.4, qSW-WW4 and qSW-DS8 were identified controlling PN, BM and SW of soybean. There were larger proportions of favorable haplotypes for locus qPN-WW19.1 and qSW-WW4 rather than qBM-WW1, qBM-DS17.4, qPN-DS8.8 and qSW-DS8 in both landraces and improved cultivars. In addition, several putative candidate genes such as Glyma.19G211300, Glyma.17G057100 and Glyma.04G124800, encoding E3 ubiquitin-protein ligase BAH1, WRKY transcription factor 11 and protein zinc induced facilitator-like 1, respectively, were predicted. We propose that the further exploration of these locus will facilitate accelerating breeding for high-yield soybean cultivars.

Field evaluation of a six-rotor unmanned agricultural aerial sprayer: effects of application parameters on spray deposition and control efficacy against rice planthopper.

BACKGROUND: Unmanned Aerial Spraying System (UASS) has emerged as an advanced, precise, and efficient tool for pesticide application in numerous nations in recent years. Despite this, there is a noticeable gap in research advocating viable, quantifiable methodologies for application parameter optimization. This investigation was primarily oriented toward identifying optimal UASS application parameters. It did so by exploring the effects of varying spray volumes and flight parameters on spray performance in a comprehensive manner, and by assessing the biological potency of aerial insecticide application against Rice Planthopper (RPH) using the optimal parameters, aided by two types of nozzles in rice field settings. RESULTS: Increased spray volume increased the spray deposition. Working height impacted the distribution of spray deposition, with a higher working height leading to superior distribution uniformity. Both spray volume and working height were observed to influence spray deposition and its percentage in tandem. Upon factor analysis, the optimal parameters determined for rice at the heading stage were an application volume of 15.0 L·ha-1 , a working height of 2.0 m, and a driving speed of 5.0 m·s-1 . Under these parameters, the air-induction twin flat fan nozzle IDKT120-015 demonstrated approximately 5% higher spray deposition than the flat fan nozzle SX11001VS, albeit with inferior distribution uniformity. Both nozzle types achieved over 93.0% control efficacy against RPH using triflumezopyrim, persisting for up to 40 days post-treatment. CONCLUSION: This study furnishes invaluable insights and data for controlling rice planthopper via UASS pesticide application, contributing to the progress of modern intensive and sustainable agriculture. © 2023 Society of Chemical Industry.

Oriented High Thermal Conductivity Solid-Solid Phase Change Materials for Mid-Temperature Solar-Thermal Energy Storage.

As the global energy crisis intensifies, the development of solar energy has become a vital area of focus for many nations. The utilization of phase change materials (PCMs) for photothermal energy storage in the medium temperature range holds great potential for various applications, but their conventional forms face several challenges. For instance, the longitudinal thermal conductivity of photothermal PCMs is inadequate for effective heat storage on the photothermal conversion surface, and there is a risk of leakage due to repeated solid-liquid phase transitions. Here, we report a solid-solid phase change material, tris(hydroxymethyl)aminomethane (TRIS), which has a phase change temperature of 132 °C in the medium temperature range, enabling high-grade and stable solar energy storage. To overcome the low thermal conductivity problem, we propose a large-scale production of oriented high thermal conductivity composites by compressing a mixture of TRIS and expanded graphite (EG) using the pressure induction method to create in-plane highly thermally conductive channels. Remarkably, the resulting phase change composites (PCCs) exhibit a directional thermal conductivity of 21.3 W/(m·K). Furthermore, the high phase change temperature (132 °C) and large phase change entropy (213.47 J/g) enable a large-capacity high-grade thermal energy to be used. The developed PCCs, when combined with selected photo-absorbers, exhibit efficient integration of solar-thermal conversion and storage. Additionally, we also demonstrated a solar-thermoelectric generator device with an energy output of 93.1 W/m2, which is close to the power of photovoltaic systems. Overall, this work provides a technological route to the large-scale fabrication of mid-temperature solar energy storage materials with high thermal conductivity, high phase change enthalpy, and no risk of leakage, and also offers a potential alternative to photovoltaic technology.

Field evaluation of spray drift and nontargeted soybean injury from unmanned aerial spraying system herbicide application under acceptable operation conditions.

BACKGROUND: Droplets of plant production products sprayed from unmanned aerial spraying system (UASS) applications are prone to drift, threatening nontarget crops, humans, and environment. There are few studies that have investigated plant bioassay of UASS spray drift, and even fewer when it comes to herbicide application. This work reports a combined field-scale evaluation of spray drift and plant bioassay for a rice herbicide florpyrauxifen-benzyl application using a six-rotor motor UASS under acceptable operating conditions. An artificial rice canopy was built to simulate a practical field application scenario and the soybean was applied to assess the nontargeted crop injury. The effects of nozzle type (droplet size), flight height, and adjuvant on spray deposition, sedimenting drift, airborne drift, and soybean injury were studied to explore the feasibility of UASS herbicide application. RESULTS: Under an average wind speed of 1.2-1.5 m s-1 , reduced flight height, increased droplet size, and adding nonionic surfactant resulted in greater deposition, lower drift, and less injury to soybean. Increasing droplet size by changing the nozzle was more effective compared with adding adjuvant and reducing the flight height, which offers greater flexibility and can accomplish better spray performance. The correlations between sedimenting drift and soybean injury percentage were highly significant (P < 0.01, r > 0.96). The calculated buffer distances of 7.7-18.9 m were to varying degrees less than the soybean safety distances of 10.0-20.0 m. CONCLUSION: The results of this study provide a reference basis for determining optimum working parameters and establishing buffer zones for the rice herbicide application of UASS. © 2022 Society of Chemical Industry.

Comprehensive assessment of intelligent unmanned vehicle techniques in pesticide application: A case study in pear orchard.

The intelligent pesticide application techniques in orchards have grown rapidly worldwide due to the decrease in agricultural populations and the increase in labor costs. However, whether and how intelligent pesticide application techniques are better than conventional pesticide application remains unclear. Here, we evaluated the performance of the unmanned aircraft vehicle (UAV) and unmanned ground vehicle (UGV) on pesticide application, ecological environment protection, and human's health protection compared to conventional manual methods. We quantified characteristics from the aspects of working effectiveness, efficiency, environmental pollution, water saving and carbon dioxide reduction. The results showed that the UAV application has the advantages of a higher working efficiency and less environmental pollution and natural resource consumption compared to the UGV and conventional manual methods despite of its worse spray performance The UGV application techniques could improve spray performance at the cost of high environmental pollution. The conventional spray gun technique was unfriendly to environmental and resource protection although it showed a better spray performance. Thus, the balance of improving spray performance and controlling environmental pollution is the key to improve the performance of UAV and UGV technology in the future. The study could be useful in the development of intelligent pesticide application techniques and provide scientific support for the transition of intelligent management in orchards.

Development of multifunctional unmanned aerial vehicles versus ground seeding and outplanting: What is more effective for improving the growth and quality of rice culture?

The agronomic processes are complex in rice production. The mechanization efficiency is low in seeding, fertilization, and pesticide application, which is labor-intensive and time-consuming. Currently, many kinds of research focus on the single operation of UAVs on rice, but there is a paucity of comprehensive applications for the whole process of seeding, fertilization, and pesticide application. Based on the previous research synthetically, a multifunctional unmanned aerial vehicle (mUAV) was designed for rice planting management based on the intelligent operation platform, which realized three functions of seeding, fertilizer spreading, and pesticide application on the same flight platform. Computational fluid dynamics (CFD) simulations were used for machine design. Field trials were used to measure operating parameters. Finally, a comparative experimental analysis of the whole process was conducted by comparing the cultivation patterns of mUAV seeding (T1) with mechanical rice direct seeder (T2), and mechanical rice transplanter (T3). The comprehensive benefit of different rice management processes was evaluated. The results showed that the downwash wind field of the mUAV fluctuated widely from 0 to 1.5 m, with the spreading height of 2.5 m, and the pesticide application height of 3 m, which meet the operational requirements. There was no significant difference in yield between T1, T2, and T3 test areas, while the differences in operational efficiency and input labor costs were large. In the sowing stage, T1 had obvious advantages since the working efficiency was 2.2 times higher than T2, and the labor cost was reduced by 68.5%. The advantages were more obvious compared to T3, the working efficiency was 4 times higher than in T3, and the labor cost was reduced by 82.5%. During the pesticide application, T1 still had an advantage, but it was not a significant increase in advantage relative to the seeding stage, in which operating efficiency increased by 1.3 times and labor costs were reduced by 25%. However, the fertilization of T1 was not advantageous due to load and other limitations. Compared to T2 and T3, operational efficiency was reduced by 80% and labor costs increased by 14.3%. It is hoped that this research will provide new equipment for rice cultivation patterns in different environments, while improving rice mechanization, reducing labor inputs, and lowering costs.

Sandwich-Structured h-BN/PVDF/h-BN Film With High Dielectric Strength and Energy Storage Density.

Energy storage film is one of the most important energy storage materials, while the performance of commercial energy storage films currently cannot meet the growing industrial requirements. Hence, this work presents a h-BN/PVDF/h-BN sandwich composite structure film prepared by laminating a large area of ultrathin hexagonal boron nitride (h-BN) and polyvinylidene fluoride (PVDF), the existence of which was confirmed by using an optical microscope and elemental composition analysis based on scanning electron microscopy and X-ray diffraction. This film has an ultrahigh dielectric strength of 464.7 kV/mm and a discharged energy density of up to 19.256 J/cm3, which is much larger than the commercial energy storage film biaxially oriented polypropylene (BOPP) (<2.5 J/cm3). Although the thickness of the h-BN film is only 70 nm compared with that of PVDF (about 12 µm), the dielectric strength of the sandwich-structured film presents a great increase. It is because of the excellent insulation performance of the h-BN film that helps to resist the electron injection and migration under high electric field, and then suppress the formation and growth of the breakdown path, leading to an improvement of the charge-discharge efficiency.

Spray performance evaluation of a six-rotor unmanned aerial vehicle sprayer for pesticide application using an orchard operation mode in apple orchards.

BACKGROUND: In the last decade, unmanned aerial vehicle (UAV) sprayers have been growing rapidly worldwide as a new method for pesticide application, especially in Asian countries. More and more manufacturers and service providers are currently aiming at UAV spraying operation for fruit trees with higher economic value. We evaluated the spray performance of an electric six-rotor UAV sprayer using an orchard operation mode (different application volumes and flight patterns) in a hilly apple orchard with small and sparse trees (SS) and a plain orchard with tall-spindle trees (TS). RESULTS: Application volume (APV) had a significant influence on the spray coverage parameters in both orchards, while flight pattern, intra-row, inter-row and verti-row, had a relatively limited influence at 60 0 and 85 7 L/ha. The UAV's downwash airflow produced a good spray penetration in the isolated SS trees, but not for the conjoined TS trees. It is better to fly along and above rows at 63.5 L/ha or higher for SS trees. The excessively low underside coverage is the main drawback of UAV orchard pesticide application and the underside droplet size was generally less than 200 µm. CONCLUSION: Spray performance is closely related to tree shape, planting pattern, UAV payload, application volume, spray droplet size and downwash airflow field. The results provide data support for the best operational practice development and the decision model for the application volume of UAV sprayer orchard operations. The underside spray performance requires further improvement by several effective measures. © 2022 Society of Chemical Industry.

Assessment of spray deposition, drift and mass balance from unmanned aerial vehicle sprayer using an artificial vineyard.

Under the rapid development of unmanned aerial vehicle (UAV) plant protection products (PPP) application in Asian countries, the drift risk of UAV sprayer operation in orchard or vineyard is fairly high because of the much finer droplets generated and the higher height than ground sprayers, increasing threats to non-targeted crop, human and environment. However, there is few of comprehensive experimental study on the effects of UAV type and nozzle type on spray deposition and drift from UAV sprayer. The objectives of this study were to compare the spray performance of three different typical commercial UAV types (helicopter, 6-rotor and 8-rotor) with two nozzles types (hollow cone nozzle, HCN and air-injector flat fan nozzle, AIN) in vineyard. An artificial vineyard and three vertical collection frames, designed and built by ourselves, were applied for collecting droplets together with PVC collectors, petri dishes and rotary samples. The characteristics of deposition, drift and mass balance of UAV aerial spraying in vineyard were analyzed. As a result, under the crosswind speed of 3.11-3.79 m/s, AIN promoted spray deposition and uniformity and reduced drift significantly compared to HCN for all tested UAVs, improving of the utilization of PPP. The fitted regression functions of the sedimenting and airborne drift were obtained, respectively, and the drift percentage reduction values of AIN compared to HCN determined based on those functions varied from 81% to 95%. With HCN, 49.3%-73.4% of measured droplets drifted into non-targeted area and the highest proportion of drift loss was found for the airborne spray drift. According to the principle of more deposition and less drift, the spray performance of the three UAVs can be ranked in an order of 6-rotor, 8-rotor and helicopter, and two main reasons causing the difference in spray performance were the vortex airflow and the nozzle arrangement.

Sequential C-F bond functionalizations of trifluoroacetamides and acetates via spin-center shifts.

Defluorinative functionalization of readily accessible trifluoromethyl groups constitutes an economical route to partially fluorinated molecules. However, the controllable replacement of one or two fluorine atoms while maintaining high chemoselectivity remains a formidable challenge. Here we describe a general strategy for sequential carbon-fluorine (C-F) bond functionalizations of trifluoroacetamides and trifluoroacetates. The reaction begins with the activation of a carbonyl oxygen atom by a 4-dimethylaminopyridine-boryl radical, followed by a spin-center shift to trigger the C-F bond scission. A chemoselectivity-controllable two-stage process enables sequential generation of difluoro- and monofluoroalkyl radicals, which are selectively functionalized with different radical traps to afford diverse fluorinated products. The reaction mechanism and the origin of chemoselectivity were established by experimental and computational approaches.

Screening diverse soybean genotypes for drought tolerance by membership function value based on multiple traits and drought-tolerant coefficient of yield.

BACKGROUND: Drought is a major limiting factor seriously influencing worldwide soybean production and its impact on yield, morphological and physiological traits depend on the timing it occurs and the intensity of water shortage. Only limited research has however been conducted on identifying the drought-tolerant genotypes at different growth stages (vegetative growth phase, reproductive growth phase and the whole growth phase) as well as evaluate the effectiveness and reliability of multiple phenotypic and yield-related characteristics in soybean. RESULTS: Two pot experiments and a 2-year field experiment were conducted to evaluate soybean drought tolerance at different growth stages. The membership function value of drought tolerance (MFVD) was used to identify drought-resistant cultivars during vegetative growth phase and reproductive growth stage; the relative drought index (RDI) of yield was used to assess drought-resistant cultivars during the whole growing period. In this study, regression models built based on MFVD indicated that the variation of drought tolerant coefficient (DC) of R/S, TRL, LAI and RSR could explain 73.70% of the total variation at vegetative growth phase. However, higher heritability only found in LAI and RSR, indicating the two traits could serve as reliable criteria for drought evaluation. Similarly, the DC of SPP, YPP, PH, PB, MSNN and STB could explain 94.30% of the total variation in MFVD according to stepwise multiple linear regression analyses at reproductive growth phase. Thus, these six traits were identified as indicators for screening drought resistance genotypes in soybean. In addition, correlation analysis revealed that the MFVD was significantly positively correlated with the DCRB, DCR/S, DCRSA, DCRSR and DCRBR at vegetative growth phase and DCYPP, DCSPP, DCRB, and DCPB at reproductive growth phase. This indicated that these traits were closely related to the drought resistance of plants. CONCLUSIONS: LD24, JD36 and TF31 of vegetative growth phase, and TD37 and LD26 of reproductive growth phase were identified with drought tolerant and highly drought tolerant, respectively. Moreover, 30 accessions with drought tolerance were screened in the field trial and could be applied for the drought resistance of other genotypes by cross-breeding.

Direct Csp3-H methylenation of 2-arylacetamides using DMF/Me2NH-BH3 as the methylene source.

A direct Csp3-H methylenation of 2-arylacetamides using DMF/Me2NH-BH3 as the methylene source was developed. The formyl group of DMF delivered the carbon and one hydrogen atoms, and the Me2NH-BH3 donated the remaining one hydrogen atom. This protocol offers a new alternative to make useful 2-arylacrylamides from simple starting materials.

Adaptive homeostasis of the vitamin D-vitamin D nuclear receptor axis in 8-methoxypsoralen-induced hepatotoxicity.

8-methoxypsoralen (8-MOP) with ultraviolet A radiation therapy (PUVA) is the standard therapy for patients with psoriasis, despite the reported potential risks of 8-MOP-induced cholestatic liver injury in both humans and animals. Usually, patients with chronic cholestasis exhibit lower serum 25-hydroxy vitamin D (25(OH)D) levels. But those patients receiving PUVA for psoriasis showed an increase in serum 25(OH)D levels, probably highlighting that the vitamin D-vitamin D nuclear receptor (VD-VDR) axis play a protective role in 8-MOP-induced hepatotoxicity. The present study confirmed 8-MOP could increase serum 25(OH)D levels in conventional lighting and diet (CLD) and vitamin D deficient (VDD) Sprague-Dawley rats. Potential liver risks were also found in CLD and VDD rats after 8-MOP treatment. We proved that 8-MOP could be a potent ligand for VDR using molecular docking and luciferase report assay. Effect of 8-MOP on VDR subcellular distribution was determined using human liver cell line L02. We found 8-MOP could increase VDR protein expression in the nuclear and cytosol extracts and also total cell extracts in L02. siRNAs for VDR were used to determine the role of VDR in protecting 8-MOP-induced cholestasis and potential cellular mechanisms. The results showed 8-MOP could affect the CYP7A1, SHP and MRP3 expression via VDR, and such effects could be reversed by knockdown of VDR expression, suggesting a vital role of VDR involved in 8-MOP-regulated bile acid synthesis and transportation. In conclusion, these results revealed activation of VD-VDR axis may play a beneficial role in 8-MOP-mediated regulation of bile acid synthesis and transportation.

CRMP2 and CRMP4 Are Differentially Required for Axon Guidance and Growth in Zebrafish Retinal Neurons.

Axons are directed to their correct targets by guidance cues during neurodevelopment. Many axon guidance cues have been discovered; however, much less known is about how the growth cones transduce the extracellular guidance cues to intracellular responses. Collapsin response mediator proteins (CRMPs) are a family of intracellular proteins that have been found to mediate growth cone behavior in vitro; however, their roles in vivo in axon development are much less explored. In zebrafish embryos, we find that CRMP2 and CRMP4 are expressed in the retinal ganglion cell layer when retinal axons are crossing the midline. Knocking down CRMP2 causes reduced elongation and premature termination of the retinal axons, while knocking down CRMP4 results in ipsilateral misprojections of retinal axons that would normally project to the contralateral brain. Furthermore, CRMP4 synchronizes with neuropilin 1 in retinal axon guidance, suggesting that CRMP4 might mediate the semaphorin/neuropilin signaling pathway. These results demonstrate that CRMP2 and CRMP4 function differentially in axon development in vivo.

The role of nanotechnology in single-cell detection: a review.

Biological processes in single cells, such as signal transduction, DNA duplication, and protein synthesis and trafficking, occur in subcellular compartments at nanoscale level. Achieving high spatial-temporal resolution, high sensitivity, and high specificity in single-cell detection poses a great challenge. Nanotechnology, which has been widely applied in the fields of medicine, electronics, biomaterials, and energy production, has the potential to provide solutions for single-cell detection. Here we present a review of the use of nanotechnology in single-cell detection over the past two decades. First, we review the main areas of scientific interest, including morphology, ion concentration, DNA, RNA, protein, intracellular temperature, elements, and mechanical properties. Second, four categories of application of nanotechnology to single-cell detection are described: nanomanipulation, nanodevices, nanomaterials as labels, and nano Secondary ion mass spectrometry. Finally, the prospects and future trends in single-cell detection and analysis are discussed.

The local heating effect by magnetic nanoparticles aggregate on support lipid bilayers.

In this paper, we established a theoretical model to investigate the local heating effect of magnetic nanoparticles (MNPs) aggregate on the support lipid bilayers (SLBs) under external alternating current (AC) magnetic field, which may be helpful to understand hyperthermia at single cell level. Using atomic force microscope (AFM), the transformation of the support phospholipid bilayers surrounding MNPs aggregate was observed in real-time. We found that the fluidity of lipid bilayers changed when the size of MNPs aggregate larger than 200 nm, as a result of magnetic heating in the AC magnetic field. These experimental data were consistent with the simulation results, which demonstrated the valid of our established model, as well as described more realistically the above phenomenon.