Two‐Dimensional Design Strategy to Construct Smart Fluorescent Probes for the Precise Tracking of Senescence

The tracking of cellular senescence usually depends on the detection of senescence‐associated β‐galactosidase (SA‐β‐gal). Previous probes for SA‐β‐gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β‐gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de‐acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA‐β‐gal from cancer‐associated β‐gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli β‐gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.<br/

Spatial and temporal characteristics of drought in the Mu Us Sandy Land based on the Standardized Precipitation Index

The environment of the Mu Us Sandy Land, northern Shaanxi, is fragile, so the temporal and spatial evolution of drought can provide a reference for ecological construction and agricultural production. Based on the daily precipitation data of five meteorological stations from 1967 to 2020, the spatial and temporal evolution characteristics of drought in the Mu Us Sandy Land of northern Shaanxi were analyzed using the methods Standardized Precipitation Index (SPI) and run-length theory. The results show that 1) the smaller the time scale, the higher the sensitivity of the SPI to primary precipitation. 2) The annual, summer, autumn, and winter SPI showed an upward and a wetting trend, and the fastest wetting speed is observed in summer, while spring showed an increasing trend of drought. 3) In the past 54 years, the duration, degree, and intensity of drought events at SPI-3 and SPI-12 scales in the Mu Us Sandy Land of northern Shaanxi showed an insignificant decreasing trend, but the decreasing rate at the SPI-12 scale was faster than that at the SPI-3 scale. The serious periods of drought are November 2018 to May 2019 and April 1999 to July 2021. 4) The duration of drought events at two timescales in each region showed a decreasing trend. The longest durations of drought were in Yulin and Jingbian; Shenmu and Dingbian are the regions with the fastest reduction rate of drought degree at the two scales. Hengshan shows rapid reduction of drought intensity at the two scales and also the region with large average drought intensity. These results are helpful in understanding and describing drought events for drought risk management under the condition of global warming

Eightfold Fermionic Excitation in a Charge Density Wave Compound

Unconventional quasiparticle excitations in condensed matter systems have become one of the most important research frontiers. Beyond two- and fourfold degenerate Weyl and Dirac fermions, three-, six- and eightfold symmetry protected degeneracies have been predicted however remain challenging to realize in solid state materials. Here, charge density wave compound TaTe4 is proposed to hold eightfold fermionic excitation and Dirac point in energy bands. High quality TaTe4 single crystals are prepared, where the charge density wave is revealed by directly imaging the atomic structure and a pseudogap of about 45 meV on the surface. Shubnikov de-Haas oscillations of TaTe4 are consistent with band structure calculation. Scanning tunneling microscopy reveals atomic step edge states on the surface of TaTe4. This work uncovers that charge density wave is able to induce new topological phases and sheds new light on the novel excitations in condensed matter materials.Comment: Accepted by PRB: https://journals.aps.org/prb/accepted/7907cK4eW0b1ee0b93fd67c1b42942bbb08eafc3

Series of In Situ Photoinduced Polymer Graftings for Sensitive Detection of Protein Biomarkers via Cascade Amplification of Liquid Crystal Signals

Developing of new polymeric materials for the sensitive and rapid detection of trace protein biomarkers has attracted increasing attention in biomedical fields. Herein, series of in situ photoinduced polymer graftings were developed for sensitive detection of protein biomarkers by using featured cascade amplification of liquid crystal (LC) signals. The limit-of-detection (LOD) for native bovine serum albumin (BSA) molecules is around 10 μg/mL in a LC biosensor before signal amplification. Upon the cascade amplification using surface-grafted polymers, poly­[poly­(ethylene glycol) methacrylate] grafting (<i>s</i>-P­(PEGMA)) exhibits superior amplification ability (10⁴-fold lower than native BSA) than the other two graftings of poly­(2-hydroxyethyl methacrylate) (<i>s</i>-PHEMA) and poly­(methacrylic acid) (<i>s</i>-PMAA; 10²-fold lower than native BSA). The contact angles of water and LC on the <i>s</i>-P­(PEGMA) grafting show significant difference in comparison with <i>s</i>-PHEMA and <i>s</i>-PMAA graftings (<i>p</i> < 0.05), implying interfacial energies of the grafted polymers may dictate the orientational transition of LCs. The clinical urine samples collected from the patients with proteinuria were also used to confirm the feasibility of the polymer-amplified LC sensors for practical protein assays. The present work reveals that in situ photoinduced polymer grafting is one promising method to amplify the signals of LC biosensors for the rapid and sensitive detection of trace protein biomarkers

Spatial and Temporal Soil Moisture Variations over China from Simulations and Observations

The Community Land Model version 4.0 (CLM4.0) driven by the forcing data of Princeton University was used to simulate soil moisture (SM) from 1961 to 2010 over China. The simulated SM was compared to the in situ SM measurements from International Soil Moisture Network over China, National Centers for Environmental Prediction (NCEP) Reanalysis data, a new microwave based multiple-satellite surface SM dataset (SM-MW), and European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA Interim/Land) SM data. The results showed that CLM4.0 simulation is capable of capturing characteristics of the spatial and temporal variations of SM. The simulated, NCEP, SM-MW, and ERA Interim/Land SM products are reasonably consistent with each other; based on the simulated SM of summer, it can be concluded that the spatial distribution in every layer was characterized by a gradually increasing pattern from the northwest to southeast. The SM increased from surface layer to deeper layer in general. The variation trends basically showed consistencies at all depths. The simulated SM of summer demonstrated different responses to the precipitation variation. The variation distribution of SM and measured precipitation had consistencies. The humid region significantly responded to precipitation, while the semiarid and arid regions were ranked second

Beyond Psychology: Prevalence of p-value and confidence interval misinterpretation across different fields

P-value and confidence intervals (CIs) are the most widely used statistical indices in scientific literature. Several surveys revealed that these two indices are generally misunderstood. However, existing surveys on this subject fall under psychology and biomedical research, and data from other disciplines are rare. Moreover, the confidence of researchers when constructing judgments remains unclear. To fill this research gap, we survey 1,479 researchers and students from different fields in China. Results reveal that for significant (p &lt; .05, CI doesn’t include 0) and non-significant (p &gt; .05, CI includes 0) conditions, most respondents, regardless of academic degrees, research fields, and stages of career, could not interpret p-value and CI accurately. Moreover, the majority of them are confident about their (inaccurate) judgments (see osf.io/mcu9q/ for raw data, materials, and supplementary analyses). Therefore, misinterpretations of p-value and CIs prevail in the whole scientific community, thus the need for statistical training in science

Effect of different NPK fertilization timing sequences management on soil-petiole system nutrient uptake and fertilizer utilization efficiency of drip irrigation cotton

Abstract In order to elucidate the effects of different nitrogen (N), phosphorus (P), and potassium (K) fertilization timing sequences management on nutrient absorption and utilization in drip irrigation cotton, field experiments were conducted from 2020 to 2021. There are six timing sequences management methods for NPK fertilization (S1–S6: 1/3Time N–1/3Time PK–1/3Time W, 1/3Time PK–1/3Time N–1/3Time W, 1/2Time NPK–1/2Time W, 1/4Time W–1/4Time N–1/4Time PK–1/4Time W, 1/3Time W–1/3Time NPK–1/3Time W), among which S6 is the current management method for field fertilization timing sequences, and S7 is the non N. The results showed that during the main growth stage, S5 accumulated more nitrate nitrogen (NO3 –-N) and ammonium nitrogen (NH4 +-N) content in soil between 20 and 40 cm, and accumulated more available phosphorus content in soil between 5–15 cm and 15–25 cm, S5 reducing N leaching and increasing P mobility. It is recommended to change the timing sequences management method of NPK fertilization for drip irrigation cotton to 1/4Time W–1/4Time PK–1/4Time N–1/4Time W, which is beneficial for plant nutrient absorption and utilization while reducing environmental pollution

Establishment of an NPK nutrient monitor system in yield-graded cotton petioles under drip irrigation

Abstract Background The determination of nutrient content in the petiole is one of the important methods for achieving cotton fertilization management. The establishment of a monitoring system for the nutrient content of cotton petioles during important growth periods under drip irrigation is of great significance for achieving precise fertilization and environmental protection. Methods A total of 100 cotton fields with an annual yield of 4500–7500 kg/ha were selected among the main cotton-growing areas of Northern Xinjiang. The nitrate nitrogen (NO3 −–N), inorganic phosphorus (PO4 3−–P) and inorganic potassium (K+–K) content and yield of cotton petioles were recorded. Based on a yield of 6000 kg/ha as the dividing line, a two-level and yield-graded monitoring system for NO3 −–N, PO4 3−–P and K+–K in cotton petioles during important growth periods was established, and predictive yield models for NO3 −–N, PO4 3−–P and K+–K in petioles during important growth periods were established. Results The results showed found that the yields of the 100 cotton fields surveyed were normally distributed. Therefore, two yield grades were classified using 6000 kg/ha as a criterion. Under different yield-graded, the NO3 −–N, PO4 3−–P and K+–K content of petiole at important growth stages was significantly positively correlated with yield. Further, the variation range of NO3 −–N, PO4 3−–P and K+–K content in petioles could be used as a standard for yield-graded. In addition, a yield prediction model for the NO3 −–N, PO4 3−–P and K+–K content of petioles was developed. The SSO-BP validation model performed the best (R2 = 0.96, RMSE = 0.06 t/ha, MAE = 0.05 t/ha) in the full bud stage, which was 12.9% higher than the BP validation model. However, the RMSE and MAE were decreased by 86.7% and 88.1%, respectively. Conclusion The establishment of NPK nutrition monitor system of cotton petioles under drip irrigation based on yield-graded provides an important basis for nutrition monitor of cotton petiole under drip irrigation in Xinjiang. It also provides a new method for cotton yield prediction

Reconfigurable Transmitarray Based on Frequency Selective Surface for 2D Wide-Angle Beam Steering

A novel reconfigurable transmitarray (RTA) with two-dimensional (2D) wide beam steering capability is presented herein. Different from the traditional RTA with the discrete phase compensation (one-bit or multi-bits phase shift), a second order parallel bandpass filter model is used to realize the RTA elements with a 180° continuous phase compensation. A sandwich structure composed of the two patches with rectangular slots and the middle ground sheet with the cruciform slot is constructed for the phase shift characteristics of the frequency selective surface (FSS), and two varactor diodes are loaded across the rectangular slots on the two top and bottom patches. The simulated results show that the proposed elements could achieve continuous transmission phase compensation from 0° to 180° with a 3 dB insert loss within the operating band of 11.8–12.6 GHz. The RTA prototype with 16×16 elements and an aperture size of 6λ0×6λ0 at 12.2 GHz is fabricated and measured for experimental verification. The measured results show that its beam scanning range can reach ±50° in both horizontal and vertical planes with a peak gain of 22.76 dBi and a aperture efficiency of 24.65%. Furthermore, the sidelobe levels (SLLs) are lower than −17.8 dB, which is much better than most RTAs. The proposed RTA has potential applications in radar, microwave imaging and wireless communication systems with low-cost fabrication and a stable performance