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References are employed in most academic research papers to give credits and to reflect scholarliness. With the upsurge in academic publications in recent decades, we are curious to know how the number of references cited per research article has changed across different disciplines over that time. The results of our study showed significant linear growth in reference density in eight disciplinary categories between 1980 and 2019 indexed in Web of Science. It appears that reference saturation is not yet in sight. Overall, the general increase in the number of publications and the advanced accessibility of the Internet and digitized documents may have promoted the growth in references in certain fields. However, the seemingly runaway tendency should be well appreciated and objectively assessed. We suggest that authors focus on their research itself rather than on political considerations during the process of writing, especially the selection of important references to cite.

It has been hypothesised that intense metabolism of nectar-inhabiting yeasts (NIY) may change nectar chemistry, including volatile profile, which may affect pollinator foraging behaviours and consequently plant fitness. However, empirical evidence for the plant-microbe-pollinator interactions remains little known. To test this hypothesis, we use a bumblebee-pollinated vine Clematis akebioides endemic to southwest China as an experimental model plant. To quantify the incidence and density of Metschnikowia reukaufii, a cosmopolitan NIY in floral nectar, a combination of yeast cultivation and microscopic cell-counting method was used. To examine the effects of NIY on plant-pollinator interactions, we used real flowers filled with artificial nectar with or without yeast cells. Then the volatile metabolites produced in the yeast-inoculated nectar were analysed with coupled gas chromatography and mass spectrometry (GC-MS). On average 79.3% of the C. akebioides flowers harboured M. reukaufii, and cell density of NIY was high to 7.4 × 104 cells mm-3 . In the field population, the presence of NIY in flowers of C. akebioides increased bumblebee (Bombus friseanus) pollinator visitation rate and consequently seed set per flower. A variety of fatty acid derivatives produced by M. reukaufii may be responsible for the above beneficial interactions. The volatiles produced by the metabolism of M. reukaufii may serve as an honest signal to attract bumblebee pollinators and indirectly promote the female reproductive fitness of C. akebioides, forming a potentially tripartite plant-microbe-pollinator mutualism.

This study evaluates the prevalence, diversity, and genetic profiles of Candida albicans isolates recovered from the oral cavities of haemodialysis patients. Oral swab samples were obtained from haemodialysis patients (n = 126) and healthy control subjects (n = 233) and Candida species were characterised. There was no significant difference between the haemodialysis and control groups in the prevalence of yeast carriers (23.6% vs. 31.0%, respectively) or C. albicans carriers (19.8% vs. 21.0%, respectively). C. albicans was the most populous species in both cohorts, followed by C. parapsilosis. C. parapsilosis and C. glabrata were more prevalent in the haemodialysis group than in the control group (C. parapsilosis 5.6% vs. 0.9% and C. glabrata 3.2% vs. 0.4%, respectively; P C. albicans isolates were analysed by multilocus sequence typing and the results were used to construct a phylogenetic tree. Most haemodialysis isolates were placed into Clade 4 (20.0%) and Clade 19 (16.0%) and most control isolates into Clade 8 (17%) and Clade 4 (14.9%). Differences in the strain abundance in each clade were not statistically significant between the two groups. Moreover, there was no significant association between the health status or diagnosis and either the sequence types or clades.

Urothelial Carcinoma Antigen 1 (UCA1) is a cell and tissue specific long non-coding RNA (lncRNA) associated with the tumorigenesis and invasion of bladder cancer. However, the mechanism driving the over-transcription of UCA1 in bladder cancer cells remains unclear. It has been reported that C/EBPβ has a significant role of regulation in tumorigenesis. Here we report that the expression of UCA1 was dramatically inhibited in 5637 cells with C/EBPβ down-regulation. Additionally, the function tests indicated that C/EBPβ could promote 5637 cells growth and colony formation by inducing the expression level of UCA1. These data suggest that C/EBPβ was involved in transcriptional regulation of UCA1 and contributed substantially to its high expression and proliferation promoting in bladder cancer cells.

Gnetum (Gnetales) has long been regarded as insect pollinated due to its range-restricted distribution in tropical rain forests, where wind pollination is supposed to be detrimental. However, ubiquitous pollen limitation in the tropics might cause transition to anemophily, or even ambophily for reproductive assurance, especially for gymnosperms such as Gnetum, which exhibit various anemophilous syndromes, including absence of petals, greenish color of strobili, dioecy and uniovulate flowers. Pollination treatments applied to Gnetum parvifolium in southern China revealed this rare and endangered species to be pollen limited and incapable of apomixis. Pollen grains of G. parvifolium did not adhere to each other and could be trapped by interception traps near the male and female strobili. Seed set in the netted treatment (anemophily) was significantly higher than in the bagged treatment (apomixis) but lower than open pollination (anemophily and entomophily), indicating that both wind and biotic pollination contributed to seed production of G. parvifolium. The occurrence of ambophily in Gnetum and the prevalence of anemophily in Ehpedra and Welwitschia suggest that wind may also play a role in the pollination of the ancient Gnetales.

Floral nectar usually functions as a pollinator reward, yet it may also attract herbivores. However, the effects of herbivore consumption of nectar or nectaries on pollination have rarely been tested. We investigated Iris bulleyana , an alpine plant that has showy tepals and abundant nectar, in the Hengduan Mountains of SW China. In this region, flowers are visited mainly by pollen-collecting pollinators and nectarivorous herbivores. We tested the hypothesis that, in I. bulleyana , sacrificing nectar and nectaries to herbivores protects tepals and thus enhances pollinator attraction. We compared rates of pollination and herbivory on different floral tissues in plants with flowers protected from nectar and nectary consumption with rates in unprotected control plants. We found that nectar and nectaries suffered more herbivore damage than did tepals in natural conditions. However, the amount of tepal damage was significantly greater in the flowers with protected nectaries than in the controls; this resulted in significant differences in pollinator visitation rates. These results provide the first evidence that floral nectar and nectaries may be ‘sacrificed’ to herbivores, leading to reduced damage to other floral tissues that are more important for reproduction.

Floral nectar usually functions as a pollinator reward, yet it may also attract herbivores. However, the effects of herbivore consumption of nectar or nectaries on pollination have rarely been tested. We investigated Iris bulleyana, an alpine plant that has showy tepals and abundant nectar, in the Hengduan Mountains of SW China. In this region, flowers are visited mainly by pollen-collecting pollinators and nectarivorous herbivores. We tested the hypothesis that, in I. bulleyana, sacrificing nectar and nectaries to herbivores protects tepals and thus enhances pollinator attraction. We compared rates of pollination and herbivory on different floral tissues in plants with flowers protected from nectar and nectary consumption with rates in unprotected control plants. We found that nectar and nectaries suffered more herbivore damage than did tepals in natural conditions. However, the amount of tepal damage was significantly greater in the flowers with protected nectaries than in the controls; this resulted in significant differences in pollinator visitation rates. These results provide the first evidence that floral nectar and nectaries may be ‘sacrificed’ to herbivores, leading to reduced damage to other floral tissues that are more important for reproduction.

Long non-coding RNA urothelial carcinoma associated 1 (UCA1) was first identified in bladder cancer tissues. High expression of UCA1 in bladder cancer has suggested it may serve as a potential diagnostic molecular marker for bladder cancer. Subsequent research in bladder cancer cell lines showed that UCA1 can promote cell proliferation, but the underlying mechanism remains unknown. In the present study, we identified BRG1 as a UCA1 binding partner using an in vitro RNA pull-down assay, and RNA-binding protein immunoprecipitation assay confirmed UCA1-BRG binding in bladder cancer cells in vivo. BRG1 is a chromatin remodeling factor with reported tumor suppressor activities that directly upregulates levels of the p21 cell cycle inhibitor by binding sequences in the p21 promoter. Depletion of UCA1 by RNAi resulted in upregulated p21 levels and inhibition of cell replication, while overexpressed UCA1 reduced p21 protein and promoted cell growth. Notably, UCA1 downregulation of p21 and induction of cell proliferation antagonized the function of BRG1. UCA1 highly expressed tissue samples are often with BRG1 high expression. Furthermore, we found that UCA1 impairs both binding of BRG1 to the p21 promoter and chromatin remodeling activity of BRG1. Collectively, these results demonstrate that UCA1 promotes bladder cancer cell proliferation by inhibiting BRG1.

While pollinators are widely acknowledged as important contributors to seed production in plant communities, we do not yet have a good understanding of the importance of pollinator specialists for this ecosystem service. Determination of the prevalence of pollinator specialists is often hindered by the occurrence of cryptic species and the limitations of observational data on pollinator visitation rates, two areas where DNA barcoding of pollinators and pollen can be useful. Further, the demonstrated adequacy of pollen DNA barcoding from historical records offers opportunities to observe the effects of pollinator loss over longer timescales, and phylogenetic approaches can elucidate the historical rates of extinction of specialist lineages. In this Viewpoint article, we review how advances in DNA barcoding and metabarcoding of plants and pollinators have brought important developments to our understanding of specialization in plant-pollinator interactions. We then put forth several lines of inquiry that we feel are especially promising for providing insight on changes in plant-pollinator interactions over space and time. Obtaining estimates of the effects of reductions in specialists will contribute to forecasting the loss of ecosystem services that will accompany the erosion of plant and pollinator diversity.

Intuitionistic fuzzy sets (IFSs), proposed by Atanassov, have gained attention from researchers for their applications in various fields. Then similarity measures between IFSs were developed. In this paper, firstly, some existing measures of similarity are reviewed. Then a new similarity measure is proposed and the relationships between some similarity measures are proved. Finally, the similarity measures of IFSs is applied to pattern recognition and the proposed similarity measures can provide a useful way for measuring IFSs more effectively.

A traditional view of diverse floral traits is that they reflect differences in foraging preferences of pollinators. The role of pollinators in the evolution of floral traits has been questioned recently by broad community surveys, especially studies concerning variation in pollinator assemblages and visitation frequency, which suggest a diminished role of pollinators in floral evolution. Here, we investigate the relationships between six categories of floral traits of 29 species and 10 pollinator functional groups in an alpine meadow in the Hengduan Mountains of China, over three consecutive years. Simpson's diversity index was used to estimate the level of pollinator generalization of each plant species by considering both pollinator groups and their relative visitation frequencies. Multivariate analyses indicated that eight of the ten pollinator groups showed constant preferences for at least two floral traits, leading to a relatively stable level of ecological generalization for most floral traits (two out of three categories), despite the fact that the level of generalization of the entire community varied across years. Shape preferences of butterflies, honeybees and beeflies varied such that open flowers exhibited a lower level of ecological generalization in 2007 than closed flowers, in contrast with the other 2 years. These results suggest that temporally stabilized preferences of diverse pollinators may contribute to the evolution of specialized versus generalized floral traits; however, their role may be moderated by variation in community structure, including both the composition and abundance of plants and pollinators.

BACKGROUND: Candida albicans is a human commensal that is also responsible for chronic gastritis and peptic ulcerous disease. Little is known about the genetic profiles of the C. albicans strains in the digestive tract of dyspeptic patients. The aim of this study was to evaluate the prevalence, diversity, and genetic profiles among C. albicans isolates recovered from natural colonization of the digestive tract in the dyspeptic patients. METHODS AND FINDINGS: Oral swab samples (n = 111) and gastric mucosa samples (n = 102) were obtained from a group of patients who presented dyspeptic symptoms or ulcer complaints. Oral swab samples (n = 162) were also obtained from healthy volunteers. C. albicans isolates were characterized and analyzed by multilocus sequence typing. The prevalence of Candida spp. in the oral samples was not significantly different between the dyspeptic group and the healthy group (36.0%, 40/111 vs. 29.6%, 48/162; P > 0.05). However, there were significant differences between the groups in the distribution of species isolated and the genotypes of the C. albicans isolates. C. albicans was isolated from 97.8% of the Candida-positive subjects in the dyspeptic group, but from only 56.3% in the healthy group (P < 0.001). DST1593 was the dominant C. albicans genotype from the digestive tract of the dyspeptic group (60%, 27/45), but not the healthy group (14.8%, 4/27) (P < 0.001). CONCLUSIONS: Our data suggest a possible link between particular C. albicans strain genotypes and the host microenvironment. Positivity for particular C. albicans genotypes could signify susceptibility to dyspepsia.

Using pollination syndrome parameters and pollinator correlations with floral phenotype from the Neotropics, we predicted that Dalechampia bidentata Blume (Euphorbiaceae) in southern China would be pollinated by female resin-collecting bees between 12 and 20 mm in length. Observations in southwestern Yunnan Province, China, revealed pollination primarily by resin-collecting female Megachile (Callomegachile) faceta Bingham (Hymenoptera: Megachilidae). These bees, at 14 mm in length, were in the predicted size range, confirming the utility of syndromes and models developed in distant regions. Phenotypic selection analyses and estimation of adaptive surfaces and adaptive accuracies together suggest that the blossoms of D. bidentata are well adapted to pollination by their most common floral visitors.

Pollinator-mediated stabilizing selection (PMSS) has been proposed as the driver of the evolutionary shift from radial to bilateral symmetry of flowers. Studies have shown that variation in flower size is lower in bilateral than in radial species, but whether bilateral flowers experience more stabilizing selection pressures by employing fewer, more specialized pollinators than radial flowers remains unclear. To test the PMSS hypothesis, we investigate plant–pollinator interactions from a whole community in an alpine meadow in Hengduan Mountains, China, to examine: (i) variance in flower size and level of ecological generalization (pollinator diversity calculated using functional groups) in 14 bilateral and 13 radial species and (ii) the role pollinator diversity played in explaining the difference of variance in flower size between bilateral and radial species. Our data showed that bilateral species had less variance in flower size and were visited by fewer pollinator groups. Pollinator diversity accounted for up to 40 per cent of the difference in variance in flower size between bilateral and radial species. The mediator effect of pollinator diversity on the relationship between floral symmetry and variance in flower size in the community is consistent with the PMSS hypothesis.

Although there has been much experimental work on floral traits that are under selection from mutualists and antagonists, selection by abiotic environmental factors on flowers has been largely ignored. Here we test whether pollen susceptibility to rain damage could have played a role in the evolution of the reproductive architecture of Davidia involucrata, an endemic in the mountains of western China. Flowers in this tree species lack a perianth and are arranged in capitula surrounded by large (up to 10 cm x 5 cm) bracts that at anthesis turn from green to white, losing their photosynthetic capability. Flowers are nectarless, and pollen grains are presented on the recurved anther walls for 5-7 days. Flower visitors, and likely pollinators, were mainly pollen-collecting bees from the genera Apis, Xylocopa, Halictus, and Lasioglossum. Capitula with natural or white paper bracts attracted significantly more bees per hour than capitula that had their bracts removed or replaced by green paper. Experimental immersion of pollen grains in water resulted in rapid loss of viability, and capitula with bracts lost less pollen to rain than did capitula that had their bracts removed, suggesting that the bracts protect the pollen from rain damage as well as attracting pollinators.

To study the DNA methylation of human telomerase reverse transcriptase (hTERT) promoter in ameloblastoma (AB) and investigate its clinical biological significance.DNA methylation of hTERT promoter in 12 cases of AB and 11 cases of normal oral mucosa were detected by methylation-specific PCR.The positive cases of unmethylated hTERT promoter region in AB and normal oral mucosa were 4 (4/12) and 6 (6/11), respectively (P0.001). The positive cases of methylated hTERT promoter region in AB and normal oral mucosa were 11 (11/12) and 3 (3/11), respectively. Four cases of AB and 1 case of normal oral mucosa showed both DNA methylation and unmethylation of hTERT promoter region in the same time.DNA methylation of of hTERT promoter region in AB was more common than that in normal oral mucosa. The DNA methylation in hTERT promoter maybe regulate hTERT gene expression.

To study the expression of HOXC13 mRNA in ameloblastoma (AB), and to investigate its biological significance.HOXC13 mRNA was examined in 47 cases of AB (primary AB 29 cases, recurrent AB 14 cases, malignant AB 4 cases). 2 cases of fibrous dysplasia of bone, 10 cases of keratocystic odontogenic tumor (KCOT) and 7 cases of normal oral mucosa were selected as control.The positive rates of HOXC13 mRNA in AB, KCOT, and normal oral mucosa were 97.9% (46/47), 7/10 and 3/7, respectively. There was a significant difference among AB, OKC and normal mucosa (chi(2) = 21.665, P = 0.001). For HOXC13, the keratinizing cells and granulizing cells in AB were negative, some fibroblasts were positive, 2 cases of fibrous dysplasia of bone were positive.HOXC13 was highly expressed in AB. The expression of HOXC13 mRNA in AB had heterogeneity, which could improve the epithelial proliferation, and its loss may lead to the cornification and degeneration of epithelial cells.

To investigate the expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in human ameloblastoma (AB), and to explore the clinical and biological characteristics of AB.The expression of cyclin E mRNA, p21(WAF1) mRNA and p27(KIP1) protein in 54 cases of human AB were detected by in situ hybridization or immunohistochemistry (SP method).The positive expression rate of cyclin E mRNA in the cytoplasm or cell nucleus of AB was 66.7% (36/54). The expression of cyclin E mRNA increased with AB recurrence and malignant transformation, and the difference of expression among primary AB, recurrent AB, and malignant AB, was statistically significant. The positive expression ratio of cyclin E mRNA in OKC was 50.0% (8/16). The p21(WAF1) mRNA expression in the cytoplasm or cell nucleus of AB decreased, and the positive ratio was 22.6% (12/54) in AB, 37.5% (6/16) in OKC, respectively. The p27(KIP1) protein expression in the cell nucleus of AB was positive in a small number of cases, and the positive rate was 16.7% (9/54) in AB, 6.3% (1/16) in OKC, respectively.The genesis and invasion of AB is associated with the cell proliferation and differentiation, and regulated by the higher expression of cyclin E and the lower expression of p21(WAF1) and p27(KIP1).

To study the oncogene transcriptor c-myc, stimulatory protein 1 (SP1) expression in ameloblastoma (AB) and their relation with telomerase reverse transcripase (hTERT), and to investigate the clinical biological characteristics of AB.The expression was observed in AB by in situ hybridization and SP method.The positive rates of c-myc mRNA, hTERT mRNA and SP1 protein were 81.5% (44/54), 94.4% (51/54) and 83.3% (45/54), respectively. Their positive rates increased as AB recurred and transformed malignantly. A strong correlation was found between hTERT and c-myc, hTERT and SP1 (rs = 0.853, P0.001; rs = 0.900, P0.001).Activity of telomerase plays an important role in the tumorigenesis development of AB. Increasing of hTERT expression may be related to c-myc and SP1. The expression of these three parameters has a significant correlation with the clinical biological characteristics of AB.