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Over recent years, the importance of the patent literature has become increasingly more recognized in the academic setting. In the context of artificial intelligence, deep learning, and data sciences, patents are relevant to not only industry but also academe and other communities. In this article, we focus on deep tomographic imaging and perform a preliminary landscape analysis of the related patent literature. Our search tool is PatSeer. Our patent bibliometric data is summarized in various figures and tables. In particular, we qualitatively analyze key deep tomographic patent literature.

Seagrass meadows are one of the most important marine ecosystems. Alkanes are the common hydrocarbon contaminants that can affect seagrass growth. In this study, a large spatial-scale investigation has been carried out on the alkane-degrading bacterial community structure in the rhizosphere and non-rhizosphere sediments of two seagrass species (Thalassia hemprichii and Halophila ovalis). AlkB gene was employed as a biomarker gene to study the alkane-degrading bacterial community structure. The results showed that the alpha diversity of the alkane-degrading bacterial community in T. hemprichii non-rhizosphere sediments was higher than that of its rhizosphere sediments. However, the alpha diversity of the alkane-degrading bacterial community in H. ovalis rhizosphere sediments was higher than that of its non-rhizosphere sediments in the open sea, but the result was contrast in the coast area. In addition, the alpha diversity of alkane-degrading bacterial communities in the coast area was higher than that of far away from the coast in the T. hemprichii rhizosphere and non-rhizosphere sediments. The phylogenetic analysis result revealed that the alkB sequences from the seagrass ecosystem were mainly affiliated with the class Alphaproteobacteria, and had the two novel lineages. Genus Agrobacterium was the most predominant alkane-degrading bacteria. These results contributed to disclose the geographical distribution pattern of alkane-degrading bacteria in the seagrass ecosystem of the South China Sea.

Seagrass meadows have seriously deteriorated in recent years. Seagrass associated phytate-mineralizing rhizobacteria potentially have functions related to seagrass nutrition, health and sustainable growth. The β-propeller phytases (BPPs) are the only phytase family in aquatic environments, but there are few studies on the BPP community structure of seagrass. In this study, clone libraries and quantitative PCR (qPCR) assays were used to compare the diversity and abundances of the BPP communities of Halodule endl, Halophila ovalis and Thalassia hemprichii in Xisha and Sanya, and to investigate the distribution characteristics of BPP genes in the rhizosphere sediment, which provedes insight into species specialty from phytic mineralization in subtropical and tropical seagrass ecosystems. The highest diversity of BPP genes was found for Thalassia hemprichii in Sanya Bay. Thalassia hemprichii in Sanya had higher abundances of BPPs, which were linked to Gammaproteobacteria. The BPP community diversity and OTUs of Thalassia hemprichii in Sanya were much higher than those of Thalassia hemprichii on Yongxing Island and Stone Island. The seagrass BPP communities had higher diversity and evenness from sampling sites with more human activity. The qPCR results showed that the abundance of phytate acid-degradating bacteria was approximately three times larger in Thalassia hemprichii rhizosphere sediment samples than in Halodule endl and Halophila ovalis rhizosphere sediment samples. This study highlighted that the diversity and abundances of bacteria genetically encoding BPP in the rhizosphere of Thalassia hemprichii were clearly higher than those of Halodule endl and Halophila ovalis. Further study of microbial phosphorus cycling will provide new insights into seagrass meadow ecosystems.

Coral reef ecosystems usually distribute in oligotrophic tropical and subtropical marine environments, but they possess great biodiversity and high productivity. It may attribute to its efficient internal nutrient cycle system. However, the knowledge of functional microbial community structure is still limited. In this study, both functional gene array (Geochip 5.0) and nifH Illumina sequencing were used to profile the overall functional genes and diazotrophic communities associated with coral Porites pukoensis. More than 7500 microbial functional genes were detected from archaea, bacteria, and fungi. Most of these genes are related to the transformation of carbon, nitrogen, sulfur, and phosphorus, providing evidence that microbes in the coral holobiont play important roles in the biogeochemical cycle of coral reef ecosystems. Our results indicated a high diversity of diazotrophs associated with corals. The dominant diazotrophic groups were related to phyla Alphaproteobacteria, Deltaproteobacteria, Cyanobacteria, and Gammaproteobacteria. And the dominant diazotrophic communities were divided into four clusters. They were affiliated with nifH sequences from genera Zymomonas, Halorhodospira, Leptolyngbya, Trichormus, and Desulfovibrio, indicating these groups may play a more important role in the nitrogen-fixing process in the coral holobiont. This study revealed functional gene diversity and suggested the roles they played in the biogeochemical cycling of the coral holobiont.

Seagrass meadows are vital ecosystems with high productivity and biodiversity and often in the oligotrophic area. Nitrogen usually limits productivity in this ecosystem as the main nutrient factor. Biological nitrogen fixation by diazotrophs in the rhizosphere sediment can introduce "new" nitrogen into the ecosystem. Previous studies revealed that most sulfate-reducing bacteria (SRB) can also fix nitrogen like the nitrogen-fixing bacteria (NFB). Moreover, both sulfate reduction and nitrogen fixation were affected by the organic pollutant. However, rare information is available regarding the NFB and SRB community composition and their temporal response to the pollutant. The quantitative real-time polymerase chain reaction and polymerase chain reaction denaturing gradient gel electrophoresis have been used to analyze NFB and SRB communities' shifts under different PAHs concentrations. They both experienced a dramatic shift under PAHs stress but exhibited different patterns. SRB could use the low and high concentration PAHs at the early stage of the incubation, while only the low concentration of PAHs could stimulate the growth of NFB through the whole incubation period. The predominant species of NFB communities were Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria; while for SRB communities were class Epsilonproteobacteria. Redundancy analysis indicated the significant environmental factors for the two communities were both ammonium and pH (P

The community structure of coral associated microorganisms will change greatly in coral bleaching. However, the relationship between specific bacteria groups and Symbiodinium, which is easy to be found in the bleaching process, has been ignored for a long time. In this study, the changes of coral microbial community during a natural bleaching event in the South China Sea were studied by 16S rRNA gene high-throughput sequencing. The microbial community composition of bleached corals was significantly different from that of normal corals (P

A whole-body MRI (WB-MRI) including T1, short time inversion recovery (STIR), diffusion-weighted imaging (high b value) was applied in our center for the detection of bone metastasis in prostate cancer (PCa) patients. We intended to assess the diagnostic performance of this examination. 547 cases of PCa patients with higher risk of metastasis were referred to bone scintigraphy with SPECT/CT (BS + SPECT/CT) and whole-body MRI in Shanghai Changhai Hospital. Best valuable comparator (BVC) was applied for the final diagnosis of metastasis. A panel of radiologists interpreted the results. Decision curve analysis (DCA) and receiver operating characteristic curve (ROC) analysis were applied. Bone metastasis was diagnosed in 110 cases, and others were non-metastatic by BVC. The area under the receiver operating characteristic curve (AUC) was higher in WB-MRI (0.778) than BS + SPECT/CT (0.634, p

Rhizosphere microbes are crucial to seagrass meadows because they promote plant growth and heath. However, information concerning the response of rhizosphere microorganisms in seagrass sediment in the presence of different nitrogen sources is lacking. Here, by means of high-throughput sequencing, we investigated how addition of inorganic nitrogen affects the rhizosphere microbiome of the tropical seagrass Thalassia hemperichii. A seagrass culture system was set up to conduct a nitrogen addition (ammonium and nitrate) simulation experiment. We found that the relative abundance of Proteobacteria and Bacteroidetes was increased in inorganic nitrogen-enriched samples, whereas that of Acidobacteria decreased under ammonium enrichment, especially after 35 days. High levels of inorganic nitrogen addition caused a significant decrease in the relative abundance of Desulfobacteraceae, Sulfurovaceae, and Spirochaetes, which are primarily involved in sulfur cycling. Additionally, the abundance of microbes in the seagrass rhizosphere reached the highest after the ammonium-enrichment treatment. Among the analyzed seagrass photosynthetic characteristics, seagrass leaves presented the highest light utility in treatments receiving nitrate, followed by the control groups and ammonium-enrichment groups. Moreover, 16S rRNA gene-predicted functional analysis suggested that some functions related to metabolism of amino acids and signal transduction were enriched in samples receiving high ammonium, whereas nitrate addition enriched predicted functions related to diseases. These findings provide new insights into the response of microbial communities to different types of nitrogen additions in seagrass ecosystems.

A novel ratiometric fluorescent probe for Cu2+ was fabricated in spherical polyelectrolyte brush (SPB) where the red-emission europium complex Eu(TTA)3Phen was embedded in the polystyrene (PS) core to generate the reference signal and the green-emission glutathione-capped CdTe quantum dot was immobilized onto the poly(styrene sulfonate) brush shell to provide the sensing signal. Results indicate that this probe has high sensitivity and selectivity for Cu2+ over other metal ions. The addition of Cu2+ could greatly quench the probe’s fluorescence at 550 nm, while the fluorescence signal at 614 nm kept unchanged. Under the optimized conditions, the intensity ratio of the two fluorescence emissions showed a linear response range from 0 to 1000 nM with a limit of detection of 1.45 nM for Cu2+. The probe is very suitable for the detection of copper contamination with quick response, low cost and great stability. SPB was proved to be an excellent “carrier” for building high-quality ratiometric probes due to its special core–shell structure and outstanding ability to enrich counterions. This work provides a versatile method for the development of high-quality ratiometric fluorescent probes, which can be extended to potential applications in various fields, such as environmental monitoring, biological imaging, pathological analysis and cancer diagnosis.

Prostate cancer is the second most common cancer in men worldwide1. Over the past decade, large-scale integrative genomics efforts have enhanced our understanding of this disease by characterizing its genetic and epigenetic landscape in thousands of patients2,3. However, most tumours profiled in these studies were obtained from patients from Western populations. Here we produced and analysed whole-genome, whole-transcriptome and DNA methylation data for 208 pairs of tumour tissue samples and matched healthy control tissue from Chinese patients with primary prostate cancer. Systematic comparison with published data from 2,554 prostate tumours revealed that the genomic alteration signatures in Chinese patients were markedly distinct from those of Western cohorts: specifically, 41% of tumours contained mutations in FOXA1 and 18% each had deletions in ZNF292 and CHD1. Alterations of the genome and epigenome were correlated and were predictive of disease phenotype and progression. Coding and noncoding mutations, as well as epimutations, converged on pathways that are important for prostate cancer, providing insights into this devastating disease. These discoveries underscore the importance of including population context in constructing comprehensive genomic maps for disease.

To develop and internally validate nomograms to help choose the optimal biopsy strategy among no biopsy, targeted biopsy (TB) only, or TB plus systematic biopsy (SB). This retrospective study included a total of 385 patients who underwent magnetic resonance imaging (MRI)-guided TB and/or SB at our institute after undergoing multiparametric MRI (mpMRI) between 2015 and 2018. We developed models to predict clinically significant prostate cancer (csPCa) based on suspicious lesions from a TB result and based on the whole prostate gland from the results of TB plus SB or SB only. Nomograms were generated using logistic regression and evaluated using receiver-operating characteristic (ROC) curve analysis, calibration curves and decision analysis. The results were validated using ROC curve and calibration on 177 patients from 2018 to 2019 at the same institute. In the multivariate analyses, prostate-specific antigen level, prostate volume, and the Prostate Imaging Reporting and Data System score were predictors of csPCa in both nomograms. Age was also included in the model for suspicious lesions, while obesity was included in the model for the whole gland. The area under the curve (AUC) in the ROC analyses of the prediction models was 0.755 for suspicious lesions and 0.887 for the whole gland. Both models performed well in the calibration and decision analyses. In the validation cohort, the ROC curve described the AUCs of 0.723 and 0.917 for the nomogram of suspicious lesions and nomogram of the whole gland, respectively. Also, the calibration curve detected low error rates for both models. Nomograms with excellent discriminative ability were developed and validated. These nomograms can be used to select the optimal biopsy strategy for individual patients in the future.

The coral microbiome plays a key role in host health by being involved in energy metabolism, nutrient cycling, and immune system formation. Inoculating coral with beneficial bacterial consortia may enhance the ability of this host to cope with complex and changing marine environments. In this study, the coral Pocillopora damicornis was inoculated with a beneficial microorganisms for corals (BMC) consortium to investigate how the coral host and its associated microbial community would respond.High-throughput 16S rRNA gene sequencing revealed no significant differences in bacterial community α-diversity. However, the bacterial community structure differed significantly between the BMC and placebo groups at the end of the experiment. Addition of the BMC consortium significantly increased the relative abundance of potentially beneficial bacteria, including the genera Mameliella and Endozoicomonas. Energy reserves and calcification rates of the coral host were also improved by the addition of the BMC consortium. Co-occurrence network analysis indicated that inoculation of coral with the exogenous BMC consortium improved the physiological status of the host by shifting the coral-associated microbial community structure.Manipulating the coral-associated microbial community may enhance the physiology of coral in normal aquarium conditions (no stress applied), which may hypothetically contribute to resilience and resistance in this host.

Drought limits the pear yield and quality. The birch-leaf pear (Pyrus betulifolia Bunge) is one of the most frequently used pear rootstocks. Identifying genes involved in drought resistance of P. betulifolia would suggest candidate genes for molecular breeding. We used single-molecule long-read sequencing technology to investigate the transcriptome of birch-leaf pear under drought stress. As a result, 362,139 consensus reads were identified using six databases, among which 342,162 genes were functionally annotated. Further, we identified 7094 long noncoding RNAs. The sequencing data contained 9891 alternative splicing and 100,836 alternative polyadenylation events. We report here the full-length sequence of birch-leaf pear, which can be used for breeding enhanced varieties.

The stimulus-responsive drug delivery system has attracted increasing attention due to its ability to enhance therapeutic efficacy and reduce side effects. Herein, a pH and glutathione (GSH) dually responsive drug carrier, hollow silica–-polyelectrolyte composite nanoparticle, was successfully prepared by using a template of spherical polyelectrolyte brush (SPB) which consists of a polystyrene (PS) core and a densely grafted linear poly(acrylic acid) (PAA) shell. The existence of PAA chains and introduction of disulfide bonds in silica framework endow the composite nanoparticles with pH and GSH dually responsive properties which were confirmed by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). With doxorubicin hydrochloride (DOX) as the model drug, the loading content and encapsulation efficiency could reach up to 43% and 96%, respectively. The drug release behavior was investigated under various environments, showing that the drug release rate increased with the decrease in pH value and the increase in GSH concentration. The prepared hollow SiO2–PAA composite nanoparticles possess a great potential as carriers for controlled drug delivery.

The hypothesis of niche differentiation with respect to resources is considered to be one of the most influential explanations for the maintenance of species diversity. The hypothesis has been examined extensively by testing its prediction of species-habitat association, which posits that the spatial distribution of species is highly correlated with environmental variables. However, we argue that widespread evidence of the species-habitat association lacks adequate rigor to justify the niche differentiation hypothesis. In this study, we tested whether and to what extent the observed species-habitat association could be caused by ecological processes other than niche differentiation, in a 20-ha subtropical forest plot. The niche differentiation hypothesis was evaluated by testing the species-habitat association and performing a cross-evaluation of the habitat-diversity expectation, which posits that a strong positive correlation exists between species diversity and habitat complexity. Failure to support the habitat-diversity expectation would at a minimum indicate that the niche differentiation hypothesis might not be the main underlying process of species distribution, despite prevalence of the species-habitat association in the same plot. Our analysis revealed that distributions of most species (86.11%) in the plot were significantly associated with at least one of eight topographical and soil nutrient variables. However, there was almost no significant positive correlation between species diversity and habitat complexity at various spatial scales in the same plot. The results indicate that additional caution is warranted when interpreting the species-habitat association from the niche differentiation perspective. A significant species-habitat association indicates only a species’ habitat preference. The association may reveal nothing about interspecific differences in habitat preference, which is a requirement of the niche differentiation hypothesis.

The vacuolar Na+/H+ antiporter NHX gene is a salt tolerance determinant in higher plants. Pyrus betulaefolia, a popular rootstock in Asia, can improve pear salt tolerance through grafting. In this study, two novel NHX genes were isolated from P. betulaefolia using its NaCl-treated transcriptome information. Both PbNHX2.1 and PbNHX2.2 have typical DNA structures and conservative protein motifs often found in vacuolar Na+/H+ antiporters. They are classified as the same NHXs in the phylogenetic tree. Furthermore, both PbNHX2s localized to the plant cell tonoplast. The NaCl treatment strongly induced the expression of PbNHX2.1 in shoots and PbNHX2.2 in the whole plant, but the transcript levels of PbNHX2.2 were much higher. This result meant that they have diverse functions during sodium ion transport in P. betulaefolia. The PbNHX2.2 transcription was influenced by polyethylene glycol and abscisic acid (ABA). An ABA cis-acting element was found in its promoter region, which indicated that PbNHX2.2 transcriptional regulation under salt and osmotic stresses may be ABA-dependent. Yeast recombined experiments revealed that PbNHX2.1 and PbNHX2.2 restored, with different efficacies, the Na+-sensitive phenotype of a endosomal/vacuolar Na+/H+ antiporter mutant, AXT3. These PbNHX2s proteins, especially PbNHX2.2, facilitated Na+ ion transport and maintained intracellular K+ status. The results suggest that PbNHX2.2 was a salt tolerance determinant and had a major function in the vacuolar compartmentalization of Na+. The information on gene features, transcriptional pattern, and the basic function of the NHX family members in P. betulaefolia will help reveal the molecular mechanism underlying salt tolerance in this species.

Hollow silica–polyelectrolyte composite nanoparticles were prepared using templates of spherical polyelectrolyte brushes which consist of a polystyrene (PS) core and a densely grafted linear poly(acrylic acid) shell. The obtained hollow particles were systematically studied by small-angle X-ray scattering (SAXS) in combination with other characterization methods such as transmission electron microscopy and dynamic light scattering. The hollow structure formed by dissolving the PS core was confirmed by the reduction of electron density to zero in the cavity through fitting SAXS data. SAXS revealed both the inward and outward expansions of the hollow silica–polyelectrolyte composite particles upon increasing pH from 3 to 9, while further increasing pH led to the partial dissolution of silica layer and even destruction of the hollow structure. SAXS was confirmed to be a unique and powerful characterization method to observe hollow silica nanoparticles, which should be ideal candidates for controlled drug delivery.

Pear is one of the most important fruit trees in temperate zones, and is cultivated widely throughout the world. Salt stress affects the normal growth of pear, and further affects fruit yield and quality. Pyrus betulaefolia is a common rootstock in pear orchards, which can improve salt tolerance by grafting pear onto it. However, limited availability of P. betulaefolia genomic information has hindered research on the mechanisms underlying this tolerance. Consequently, we comprehensively analyzed P. betulaefolia salt tolerance using RNA-Seq under NaCl and NaCl + LaCl3 treatments in leaf and root. Based on mapping analyses, 3796 novel transcripts were identified, which contained 18 differentially expressed genes (DEGs). There were 90,752 alternative splicing events identified, with transcription start site and transcription terminal site as the major splicing patterns. In addition, we identified 583 differential expressed exons. A total of 276 DEGs were identified among all six comparisons, and 237 of these were up-regulated and 39 were down-regulated. One DEG (Pbr038831.1) was detected in all treatments, and was up-regulated. All DEGs were divided into three clusters according to hierarchical clustering. Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that 18 DEGs were located in six significantly enriched terms, and specific enriched categories and DEGs were identified for NaCl and NaCl + LaCl3 treatments. All of these enriched genes may be related to salt stress in P. betulaefolia. This transcriptome analysis will provide a rich genetic resource for gene discovery related to salt tolerance in P. betulaefolia and closely related species. The data will serve as an important public information platform to further understanding of the molecular mechanisms involved in salt tolerance in P. betulaefolia.

Ammonium is the primarily nitrogen source for plant growth, but the molecular basis of ammonium acquisition in fruit species remains poorly understood. In this study, we report on the characterization of two new ammonium transporters (AMT) in the perennial tree Pyrus betulaefolia. In silico analyses and yeast complementation assays revealed that both PbAMT1;3 and PbAMT1;5 can be classified in the AMT1 sub-family. The specific expression of PbAMT1;3 in roots and of PbAMT1;5 in leaves indicates that they have diverse functions in ammonium uptake or transport in P. betulaefolia. Their expression was strongly influenced by ammonium availability. In addition, the transcript level of PbAMT1;5 was significantly affected by the diurnal cycle and senescence hormones. They conferred the ability to uptake nitrogen to the yeast strain 31019b; however, the (15)NH4 (+) uptake kinetics of PbAMT1;3 were different from those of PbAMT1;5. Indeed, PbAMT1;3 had a higher affinity for (15)NH4 (+), and pH changes were associated with this substrates' transport in yeast. The present study provides basic gene features and transcriptional information for the two new members of the AMT1 sub-family in P. betulaefolia and will aid in decoding the precise roles of AMTs in P. betulaefolia physiology.

BiFeO3–PbTiO3 (BF–PT) solid solution thin films were deposited on LaNiO3/SiO2/Si substrates by a sol–gel multilayer deposition method in a super clean room with rapid thermal annealing (RTA) technique. XRD patterns of all the films demonstrate a single perovskite phase. The induced orientation of LaNiO3 substrates leads to highly (100) oriented texture. Cross-section SEM and EDS pictures confirmed that the BFPT-based films are about 230 nm thickness and had formed a dense and uniform solid solution. Film with a ratio of BF:PT = 1:2 (BFPT1-2) possesses best ferroelectric properties. A saturated hysteresis loop with a remnant polarization of 66 μC/cm2 measured at room temperature was obtained, much higher than that of BFPT7030 thin film, which was prepared by depositing BFPT7030 sol directly on LaNiO3/SiO2/Si substrates without multilayer deposition. BFPT1-2 thin films also showed better dielectric and leakage current properties than BFPT7030 thin film in the test range of electric field and frequency. BFPT1-2 thin films exhibit lowest leakage current and loss tangent, indicating that a high quality of BFPT1-2 thin film was successfully prepared by multilayer deposition method with a RTA technique with heating rate of 1 °C/s.

Background Plant height (PH) and ear height (EH) are two important agronomic traits in maize selection breeding. F1 hybrid exhibit significant heterosis for PH and EH as compared to their parental inbred lines. To understand the genetic basis of heterosis controlling PH and EH, we conducted quantitative trait locus (QTL) analysis using a recombinant inbreed line (RIL) based design III population derived from the elite maize hybrid Zhengdan 958 in five environments. Results A total of 14 environmentally stable QTLs were identified, and the number of QTLs for Z1 and Z2 populations was six and eight, respectively. Notably, all the eight environmentally stable QTLs for Z2 were characterized by overdominance effect (OD), suggesting that overdominant QTLs were the most important contributors to heterosis for PH and EH. Furthermore, 14 environmentally stable QTLs were anchored on six genomic regions, among which four are trait-specific QTLs, suggesting that the genetic basis for PH and EH is partially different. Additionally, qPH.A-1.3, modifying about 10 centimeters of PH, was further validated in backcross populations. Conclusions The genetic basis for PH and EH is partially different, and overdominant QTLs are important factors for heterosis of PH and EH. A major QTL qPH.A-1.3 may be a desired target for genetic improvement of maize plant height. Electronic supplementary material The online version of this article (doi:10.1186/s12863-017-0503-9) contains supplementary material, which is available to authorized users.

Pyrus calleryana Decne. is widely used as a pear rootstocks in Asia. Glutathione (GSH) can induce the phytochelatin synthase gene’s (PcPCS1) transcription in this plant when exposed to cadmium. This phenomenon indicated that GSH plays a vital role in protecting P. calleryana from cadmium stress. Here, we have isolated and characterized a gene encoding γ-glutamylcysteine synthetase (PcγECS), the key enzyme of GSH biosynthesis, from the leaves of P. calleryana, with the aim of expanding our knowledge of the role of GSH at the molecular level. P. calleryana plants treated with cadmium, salt, PEG6000, or mannitol responded by increasing transcription of the PcγECS gene. The response was specific for cadmium, which causes a toxicity that is thought to be mitigated through phtochelatins, and other treatments that cause damage that can be relieved by the synthesis of GSH. Feeding experiments suggested that cysteine contributed to activating the transcription of PcγECS and GSH synthesis. However, the gene’s expression was inhibited in the presence of GSH. Recombinant Escherichia coli carrying PcγECS had higher GSH synthesis levels and grew better than the control cells under cadmium, salt, or osmotic stresses. These results suggest that PcγECS may participate in responses against multiple environmental stimuli in P. calleryana.

Conspecific adults have strong negative effect on the survival of nearby early-stage seedlings and thus can promote species coexistence by providing space for the regeneration of heterospecifics. The leaf litter fall from the conspecific adults, and it could mediate this conspecific negative adult effect. However, field evidence for such effect of conspecific leaf litter remains absent. In this study, we used generalized linear mixed models to assess the effects of conspecific leaf litter on the early-stage seedling survival of four dominant species (Machilus leptophylla, Litsea elongate, Acer pubinerve and Distylium myricoides) in early-stage seedlings in a subtropical evergreen broad-leaved forest in eastern China. Our results consistently showed that the conspecific leaf litter of three species negatively affected the seedling survival. Meanwhile, the traditional conspecific adult neighborhood indices failed to detect this negative conspecific adult effect. Our study revealed that the accumulation of conspecific leaf litter around adults can largely reduce the survival rate of nearby seedlings. Ignoring it could result in underestimation of the importance of negative density dependence and negative species interactions in the natural forest communities.

RT-qPCR is a widely used method in gene expression and transcriptome studies. Normalization based on reference genes is necessary to accurately analyze RT-qPCR data. Thus, an accurate and systematic evaluation of these reference genes before experiments are conducted is necessary. In this study, 18 candidate reference genes were evaluated under various experimental conditions covering a range of tissue types and cultivars, NaCl, CaCl2 and temperature treatments, hormones (6-BA, ABA and NAA) and a set of osmotic stress (mannitol and PEG6000) treatments. Gene expression across 48 pear samples was evaluated using geNorm, NormFinder and BestKeeper statistical algorithms. Actin2/7 (ACT2/7), ubiquitin extension protein (UBI) and Yellow-leaf-specific gene 8 (YLS8) exhibited the most stable expression across all the pear samples tested. While in the other experimental groups, different sets of samples had their own best reference genes. In addition, the gene expression of PbCBL7, a member of the calcineurin B-like protein, was measured across all the 48 samples using the best three reference genes, it displayed variation in gene expression across different tissues and cultivars, and exhibited diverse up- or down-regulated expression patterns under various treatments, which indicate that PbCBL7 may play a role in response to specific abiotic stress in pear. These results are valuable for future research on gene expression and abiotic stress tolerance in pear.