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Small subunit ribosomal DNA (SSU rDNA) is widely used for phylogenetic inference, barcoding and other taxonomy-based analyses. Recent studies indicate that SSU rDNA of ciliates may have a high level of sequence variation within a single cell, which impacts the interpretation of rDNA-based surveys. However, sequence variation can come from a variety of sources including experimental errors, especially the mutations generated by DNA polymerase in PCR. In the present study, we explore the impact of four DNA polymerases on sequence variation and find that low-fidelity polymerases exaggerate the estimates of single-cell sequence variation. Therefore, using a polymerase with high fidelity is essential for surveys of sequence variation. Another source of variation results from errors during amplification of SSU rDNA within the polyploidy somatic macronuclei of ciliates. To investigate further the impact of SSU rDNA copy number variation, we use a high-fidelity polymerase to examine the intra-individual SSU rDNA polymorphism in ciliates with varying levels of macronuclear amplification: Halteria grandinella, Blepharisma americanum and Strombidium stylifer. We estimate the rDNA copy numbers of these three species by single-cell quantitative PCR. The results indicate that: (i) sequence variation of SSU rDNA within a single cell is authentic in ciliates, but the level of intra-individual SSU rDNA polymorphism varies greatly among species; (ii) rDNA copy numbers vary greatly among species, even those within the same class; (iii) the average rDNA copy number of Halteria grandinella is about 567 893 (s.d. = 165 481), which is the highest record of rDNA copy number in ciliates to date; and (iv) based on our data and the records from previous studies, it is not always true in ciliates that rDNA copy numbers are positively correlated with cell or genome size.

Perovskite/silicon tandem solar cells hold great promise for realizing high power conversion efficiency at low cost. However, achieving scalable fabrication of wide-bandgap perovskite (~1.68 eV) in air, without the protective environment of an inert atmosphere, remains challenging due to moisture-induced degradation of perovskite films. Herein, this study reveals that the extent of moisture interference is significantly influenced by the properties of solvent. We further demonstrate that n-Butanol (nBA), with its low polarity and moderate volatilization rate, not only mitigates the detrimental effects of moisture in air during scalable fabrication but also enhances the uniformity of perovskite films. This approach enables us to achieve an impressive efficiency of 29.4% (certified 28.7%) for double-sided textured perovskite/silicon tandem cells featuring large-size pyramids (2–3 μm) and 26.3% over an aperture area of 16 cm 2 . This advance provides a route for large-scale production of perovskite/silicon tandem solar cells, marking a significant stride toward their commercial viability. The scalable fabrication of wide-bandgap perovskites in air remains challenging due to moisture-induced degradation of perovskites. Here, authors utilize low polarity and moderately volatile n-butanol to enhance film uniformity, achieving efficiency of 29.4% for double-sided textured tandem cells.

The commonly-used superstrate configuration (depositing front subcell first and then depositing back subcell) in all-perovskite tandem solar cells is disadvantageous for long-term stability due to oxidizable narrow-bandgap perovskite assembled last and easily exposable to air. Here we reverse the processing order and demonstrate all-perovskite tandems in a substrate configuration (depositing back subcell first and then depositing front subcell) to bury oxidizable narrow-bandgap perovskite deep in the device stack. By using guanidinium tetrafluoroborate additive in wide-bandgap perovskite subcell, we achieve an efficiency of 25.3% for the substrate-configured all-perovskite tandem cells. The unencapsulated devices exhibit no performance degradation after storage in dry air for 1000 hours. The substrate configuration also widens the choice of flexible substrates: we achieve 24.1% and 20.3% efficient flexible all-perovskite tandem solar cells on copper-coated polyethylene naphthalene and copper metal foil, respectively. Substrate configuration offers a promising route to unleash the commercial potential of all-perovskite tandem solar cells. The superstate configuration in all-perovskite tandem solar cells is disadvantageous for long-term stability. Here, the authors reverse the processing order and demonstrate substrate configuration to bury oxidizable narrow-bandgap perovskites, and achieve efficiency of 25.3% with long stability.

The development of surveillance video vehicle detection technology in modern intelligent transportation systems is closely related to the operation and safety of highways and urban road systems. Yet, the current object detection network structure is complex, requiring a large number of parameters and calculations, so this paper proposes a lightweight network based on YOLOv5. It can be easily deployed on video surveillance equipment even with limited performance, while ensuring real-time and accurate vehicle detection. Modified MobileNetV2 is used as the backbone feature extraction network of YOLOv5, and DSC “depthwise separable convolution” is used to replace the standard convolution in the bottleneck layer structure. The lightweight YOLOv5 is evaluated in the UA-DETRAC and BDD100k datasets. Experimental results show that this method reduces the number of parameters by 95% as compared with the original YOLOv5s and achieves a good tradeoff between precision and speed.

Melatonin receptor (MTR) plays a crucial role in mediating melatonin signaling. Therefore, it is necessary to study functions and characteristics of MTR. In this study, full length cDNA of MTRI in Procambarus clarkii was cloned. The phylogenetic tree revealed that MTRI amino acid sequence of P. clarkii had the closest relationship with Homarus americanus . The temporal and spatial distribution expression results indicated that MTRI was highly expressed in gonadal tissues and eyestalk. RNA interference (RNAi) was used to identify the content of related hormones and the relative expression of genes in gonads of P. clarkii . The results showed that melatonin had an important effect on gonad of P. clarkii . Due to the specificity of the reproductive system in female and male crayfish, the siRNA interference efficiency was different, GIH, GTH, 5-HT and MT showed the opposite trend. Levels decreased in females but increased in males. However, the sex hormones E2 and T decreased, indicating that the silencing of MTRI will hinder gonadal development. This study provides a theoretical basis for further study of the role of melatonin in crustacean gonads.

To investigate interspecific variation in heat tolerance and underlying adaptation mechanisms in , three-year-old potted seedlings of eight taxa, representing four subgenera within the genus , were subjected to 40 °C high-temperature stress. Heat tolerance was comprehensively assessed using phenotypic observation, chlorophyll fluorescence imaging, microscopic examination, and physiological measurements. Results revealed that leaf damage in and reached grade III, whereas exhibited only grade II injury with rapid recovery. Chlorophyll fluorescence analysis showed a significant decrease in the maximum quantum efficiency of PSII (F /F ) in and , followed by rapid recovery, while maintained stable F /F values. Stomatal closure occurred in all taxa post-stress; stomatal characteristics of and remained stable, and leaf tissue structure was least affected in . demonstrated the most pronounced structural recovery. Physiologically, exhibited the greatest increases in electrolyte leakage (EL) and malondialdehyde (MDA) content. accumulated the highest proline content under stress, while showed the most significant proline reduction during recovery. By integrating multiple indicators through principal component analysis (PCA) and a membership function, and assigning weights based on variance contribution, the heat tolerance was comprehensively evaluated and ranked as follows: > > > > > > > . These findings demonstrate significant differences in heat tolerance among taxa at the subgenus level, with the subgenus generally possessing stronger short-term heat tolerance compared to the subgenus . This study provides a theoretical basis for heat-tolerant cultivar breeding and landscape application of .

One of the most diverse clades of ciliated protozoa, the class Spirotrichea, displays a series of unique characters in terms of eukaryotic macronuclear (MAC) genome, including high fragmentation that produces nanochromosomes. However, the genomic diversity and evolution of nanochromosomes and gene families for spirotrich MAC genomes are poorly understood. In this study, we assemble the MAC genome of a representative euplotid (a new model organism in Spirotrichea) species, Euplotes aediculatus . Our results indicate that: (a) the MAC genome includes 35,465 contigs with a total length of 97.3 Mb and a contig N50 of 3.4 kb, and contains 13,145 complete nanochromosomes and 43,194 predicted genes, with the majority of these nanochromosomes containing tiny introns and harboring only one gene; (b) genomic comparisons between E. aediculatus and other reported spirotrichs indicate that average GC content and genome fragmentation levels exhibit interspecific variation, and chromosome breaking sites (CBSs) might be lost during evolution, resulting in the increase of multi-gene nanochromosome; (c) gene families associated with chitin metabolism and FoxO signaling pathway are expanded in E. aediculatus , suggesting their potential roles in environment adaptation and survival strategies of E. aediculatus ; and (d) a programmed ribosomal frameshift (PRF) with a conservative motif 5′-AAATAR-3′ tends to occur in longer genes with more exons, and PRF genes play an important role in many cellular regulation processes.

Bifacial monolithic all-perovskite tandem solar cells have the promise of delivering higher output power density by inheriting the advantages of both tandem and bifacial architectures simultaneously. Herein, we demonstrate, for the first time, the bifacial monolithic all-perovskite tandem solar cells and reveal their output power potential. The bifacial tandems are realized by replacing the rear metal electrodes of monofacial tandems with transparent conduction oxide electrodes. Bandgap engineering is deployed to achieve current matching under various rear illumination conditions. The bifacial tandems show a high output power density of 28.51 mW cm −2 under a realistic rear illumination (30 mW cm − 2 ). Further energy yield calculation shows substantial energy yield gain for bifacial tandems compared with the monofacial tandems under various ground albedo for different climatic conditions. This work provides a new device architecture for higher output power for all-perovskite tandem solar cells under real-world conditions.

Background Encystment is an important survival strategy extensively employed by microbial organisms to survive unfavorable conditions. Single-celled ciliated protists (ciliates) are popular model eukaryotes for studying encystment, whereby these cells degenerate their ciliary structures and develop cyst walls, then reverse the process under more favorable conditions. However, to date, the evolutionary basis and mechanism for encystment in ciliates is largely unknown. With the rapid development of high-throughput sequencing technologies, genome sequencing and comparative genomics of ciliates have become effective methods to provide insights into above questions. Results Here, we profiled the MAC genome of Pseudourostyla cristata , a model hypotrich ciliate for encystment studies. Like other hypotrich MAC genomes, the P. cristata MAC genome is extremely fragmented with a single gene on most chromosomes, and encodes introns that are generally small and lack a conserved branch point for pre-mRNA splicing. Gene family expansion analyses indicate that multiple gene families involved in the encystment are expanded during the evolution of P. cristata . Furthermore, genomic comparisons with other five representative hypotrichs indicate that gene families of phosphorelay sensor kinase, which play a role in the two-component signal transduction system that is related to encystment, show significant expansion among all six hypotrichs. Additionally, cyst wall-related chitin synthase genes have experienced structural changes that increase them from single-exon to multi-exon genes during evolution. These genomic features potentially promote the encystment in hypotrichs and enhance their ability to survive in adverse environments during evolution. Conclusions We systematically investigated the genomic structure of hypotrichs and key evolutionary phenomenon, gene family expansion, for encystment promotion in ciliates. In summary, our results provided insights into the evolutionary mechanism of encystment in ciliates.

Plastic pyrolysis can not only effectively solve the environmental pollution caused by the large use of plastics products but also can produce valuable chemical products to alleviate the energy shortage problem. Firstly, this study designs a microwave pyrolysis device for polypropylene plastic based on a symmetrical circular waveguide slot radiation structure. The microwave energy is fed in through the bottom symmetrical circular waveguide port, transmitted to the slot array unit after passing through the horn amplification structure, and then uniformly radiated into the polypropylene plastic. Secondly, the finite element method is employed to conduct multi-physics field coupling calculations for the electromagnetic field, temperature field, chemical reaction field, mass transfer field of concentrated substances, and fluid field involved in the microwave pyrolysis process. Finally, to improve the efficiency of microwave pyrolysis, the wave-absorbing material SiC is introduced to investigate the effects of different doping methods and doping mass ratios mSiC:mPP on pyrolysis temperature distribution uniformity, pyrolysis gas yield (YG), energy consumption (Q), gas composition, and higher heating value (HHV). The results indicate that optimal pyrolysis performance is achieved when the microwave power is 1000 W, the pyrolysis time is 9.2 min, SiC is uniformly doped and the mass ratio is mSiC:mPP = 3:1. The COV of temperature is a mere 0.0004, the YG reaches 75.15 wt.%, and Q is 0.15 kWh, the HHV is up to 85.32 MJ/Nm3, and the percentages of C3H6 and CH4 are relatively high at 72% and 11.4%. These findings confirm the designed microwave pyrolysis device can achieve uniform and high-efficiency pyrolysis capability for polypropylene plastic.