Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase alle...Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase allele mining using six updated FNP marker systems,the functional haplotypes at Pit,Pib,and Pi63 strictly diverged into the X-populations and were defined as X-R loci,while those at Pi54,Pi37,and Pi36 into the G-populations as G-R loci.The genic diversity at the three X-R loci(16 alleles)was twofold higher than that at the three G-R loci(8 alleles),and the allelic diversity in the Southern region(21 alleles)was nearly double that in the Northeastern region(11 alleles).Both observations reflect a significant difference in genetic diversity between X-and G-populations,and indicate that the effective R-genes mainly originated from X-subspecies.Based on the allelic structures characterized by a set of 10 parameters,8 and 16 alleles were respectively recognized as favorable and promising ones for the regional breeding programs.The genotypic structures of the two regional populations were almost different,indicating that the diverged alleles have been further assembled into two series of regional genotypes through long-term breeding programs,despite the presence of one-third of region-common alleles.The genotypic diversity in the Southern region(55 genotypes)was nearly twice as high as that in the Northeastern region(28),which perfectly reflects the aforementioned differences in both genic and allelic diversities.After analyzing the genotypic structures using a set of 13 parameters,4 and 23 genotypes,respectively,can be recommended as the favorable and promising ones for the regional breeding programs.The case study serves as a concrete sample of how to identify the favorable and promising alleles and genotypes,and beneficial parents based their comprehensive population structures for gene-designed breeding.展开更多
How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the ...How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.展开更多
Financial market liquidity is a popular research topic.Investor-driven research uses the turnover rate to measure liquidity and generally finds that the higher the stock turnover rate,the lower the returns.However,the...Financial market liquidity is a popular research topic.Investor-driven research uses the turnover rate to measure liquidity and generally finds that the higher the stock turnover rate,the lower the returns.However,the traditional financial liquidity theory has been impacted by new machine-driven quantitative trading models.To explore high machine-driven liquidity and the impact of high turnover rates on returns,this study establishes a dual-market quantitative trading system,introduces a variational modal decomposition(VMD)-bidirectional gated recurrent unit(BiGRU)model for data prediction,and uses the back-end Hong Kong foreign exchange market to develop a quantitative trading strategy using the same rotating funds in the U.S.and Chinese stock markets.The experimental results show that given a principal amount of 210,000.00 CNY,the final predicted net return is 226,538.30 CNY,a net return of 107.86%,which is 40.6%higher than the net return of a single Chinese market.We conclude that,under machine-driven trading,increasing liquidity and turnover increase returns.This study provides a new perspective on liquidity theory that is useful for future financial market research and quantitative trading practices.展开更多
The publisher regrets that some of the authors’affiliations were mistakenly annotated in the manuscript.Hence,the authors of the below article were contacted after publication to request a correction of the author af...The publisher regrets that some of the authors’affiliations were mistakenly annotated in the manuscript.Hence,the authors of the below article were contacted after publication to request a correction of the author affliction and responded with the correct by the time this erratum is being published.展开更多
AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 norm...AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined. RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021). CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells.展开更多
Objective: To investigate the prognostic value of pretreatment human papillomavirus(HPV) viral load for cervical cancer, and to develop nomograms based on HPV load and other clinicopathological factors for long-term s...Objective: To investigate the prognostic value of pretreatment human papillomavirus(HPV) viral load for cervical cancer, and to develop nomograms based on HPV load and other clinicopathological factors for long-term survival.Methods: We conducted a prospective study on cervical squamous cell carcinoma(SCC) patients diagnosed between January 2003 and December 2008. Cervical samples were tested for HPV viral load by the Hybrid Capture II(HCII) assay before treatment and 6 months after treatment. Clinical characteristics and follow-up information were also collected. A multivariable Cox proportional hazards model was used to adjust covariates in both the radical hysterectomy(RH) treatment group and concurrent chemoradiotherapy(CCRT) treatment group to identify relevant covariates, and then nomograms were constructed and used for internal validation.Results: A total of 520 SCC patients enrolled in this study with a median follow-up of 127 months, 360 patients received RH, whereas 160 patients received CCRT. The median HPV viral load in RH and CCRT groups was356.10 and 294.29, respectively. Tumor size was positively correlated with high pretreatment HPV load in both groups. In CCRT group, the advanced International Federation of Gynecology and Obstetrics(FIGO) stage and enlarged retroperitoneal lymph node status determined by computed tomography(LNSCT) were correlated with low HPV load group. Initial HPV viral load, FIGO stage and lymph node metastasis were prognostic factors for RH group, whereas HPV viral load, squamous cell carcinoma antigen(SCC-Ag) level and LNSCT were identified as prognostic factors for CCRT group. Nomograms incorporating these predictors for 10-year progression-free survival(PFS) were constructed [concordance index(C-index): 0.756, 0.749].Conclusions: A low pretreatment HPV viral load is an independent prognostic factor for poor prognosis of cervical SCC and is related to other clinicopathological factors. The survival nomogram based on HPV viral load could predict the long-term prognosis.展开更多
Like other solid tumors,colorectal cancer(CRC) is a genomic disorder in which various types of genomic alterations,such as point mutations,genomic rearrangements,gene fusions,or chromosomal copy number alterations,can...Like other solid tumors,colorectal cancer(CRC) is a genomic disorder in which various types of genomic alterations,such as point mutations,genomic rearrangements,gene fusions,or chromosomal copy number alterations,can contribute to the initiation and progression of the disease. The advent of a new DNA sequencing technology known as next-generation sequencing(NGS) has revolutionized the speed and throughput of cataloguing such cancer-related genomic alterations. Now the challenge is how to exploit this advanced technology to better understand the underlying molecular mechanism of colorectal carcinogenesis and to identify clinically relevant genetic biomarkers for diagnosis and personalized therapeutics. In this review,we will introduce NGS-based cancer genomics studies focusing on those of CRC,including a recent large-scale report from the Cancer Genome Atlas. We will mainly discuss how NGS-based exome-,whole genome- and methylome-sequencing have extended our understanding of colorectal carcinogenesis. We will also introduce the unique genomic features of CRC discovered by NGS technologies,such as the relationship with bacterial pathogens and the massive genomic rearrangements of chromothripsis. Finally,we will discuss the necessary steps prior to development of a clinical application of NGS-related findings for the advanced management of patients with CRC.展开更多
Electrochemical carbon dioxide(CO2)reduction is considered to be an efficient strategy to produce usable fuels and overcome the concerns regarding global warming.For this purpose,an efficient,earth abundant,and a low ...Electrochemical carbon dioxide(CO2)reduction is considered to be an efficient strategy to produce usable fuels and overcome the concerns regarding global warming.For this purpose,an efficient,earth abundant,and a low cost catalyst has to be designed.It has been found that graphene-based materials could be promising candidates for CO2 conversion because of their unique physical,mechanical,and electronic properties.In addition,the surface of graphenebased materials can be modified by using different strategies,including doping,defect engineering,producing composite structures,and wrapping shapes.In this review,the fundamentals of electrochemical CO2 reduction and recent progress of graphene-based catalysts are investigated.Furthermore,recent studies on graphene-based materials for CO2 reduction are summarized.展开更多
Background:In biological systems,biological diversity often displays a rapid turn-over across elevations.This defining feature has made mountains classic systems for studying the spatial variation in diversity.Because...Background:In biological systems,biological diversity often displays a rapid turn-over across elevations.This defining feature has made mountains classic systems for studying the spatial variation in diversity.Because patterns of elevational diversity can vary among lineages and mountain systems it remains difficult to extrapolate findings from one montane region to another,or among lineages.In this study,we assessed patterns and drivers of avian diversity along an elevational gradient on the eastern slope of Mt.Gongga,the highest peak in the Hengduan Mountain Range in central China,and a mountain where comprehensive studies of avian diversity are still lacking.Methods:We surveyed bird species in eight 400-m elevational bands from 1200 to 4400 m a.s.l.between 2012 and 2017.To test the relationship between bird species richness and environmental factors,we examined the relative importance of seven ecological variables on breeding season distribution patterns:land area(LA),mean daily temperature(MDT),seasonal temperature range(STR),the mid-domain effect(MDE),seasonal precipitation(SP),invertebrate biomass(IB) and enhanced vegetation index(EVI).Climate data were obtained from five local meteorological stations and three temperature/relative humidity smart sensors in 2016.Results:A total of 219 bird species were recorded in the field,of which 204 were recorded during the breeding season(April–August).Species richness curves(calculated separately for total species,large-ranged species,and smallranged species) were all hump-shaped.Large-ranged species contributed more to the total species richness pattern than small-ranged species.EVI and IB were positively correlated with total species richness and small-ranged species richness.LA and MDT were positively correlated with small-ranged species richness,while STR and SP were negatively correlated with small-ranged species richness.MDE was positively correlated with large-ranged species richness.When we considered the combination of candidate factors using multiple regression models and model-averaging,total species richness and large-ranged species richness were correlated with STR(negative) and MDE(positive),while small-ranged species richness was correlated with STR(negative) and IB(positive).Conclusions:Although no single key factor or suite of factors could explain patterns of diversity,we found that MDE,IB and STR play important but varying roles in shaping the elevational richness patterns of different bird species categories.Model-averaging indicates that small-ranged species appear to be mostly influenced by IB,as opposed to large-ranged species,which exhibit patterns more consistent with the MDE model.Our data also indicate that the species richness varied between seasons,offering a promising direction for future work.展开更多
The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding betw...The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding between polymer and water molecules, and between water-water molecules even at a concentration range of 0.1% - 1.0% (W/V) at room temperature, resulting in gelation. Such dramatic changes from liquid into gels have been understood at the molecular level in principles. In this review, we describe the structure-function relationship of starch on the view point of rheological aspects and discuss gelatinization and retrogradation mechanism including water molecules at molecular level. The starch molecules (amylose and amylopectin) play a dominant role in the center of the tetrahedral cavities occupied by water molecules, and the arrangement is partially similar to a tetrahedral structure in a gelatinization process. The arrangement should lead to a cooperative effect stabilizing extended regions of ice-like water with hydrogen bonding on the surface of the polymer molecules, where hemiacetal oxygen and hydroxyl groups might participate in hydrogen bonding with water molecules. Thus, a more extended ice-like hydrogen bonding within water molecules might be achieved in a retrogradation process. Though many investigations not only include starch gelatinization and retrogradaion, but also the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, no other researchers have established mechanism at the molecular level. There is reasonable consistency in our investigations.展开更多
When preparing large monocrystalline silicon materials,severe carbon etching and silicide deposition often occur to the thermal system.Therefore,a suppression method that optimizes the upper insulation structure has b...When preparing large monocrystalline silicon materials,severe carbon etching and silicide deposition often occur to the thermal system.Therefore,a suppression method that optimizes the upper insulation structure has been proposed.Assisted by the finite element method,we calculated temperature distribution and carbon deposition of heater and heat shield,made the rule of silicide and temperature distributing in the system,and we explained the formation of impurity deposition.Our results show that the optimized thermal system reduces carbon etching loss on heat components.The lowered pressure of the furnace brings a rapid decrease of silicide deposition.The increase of the argon flow rate effectively inhibits CO and back diffusion.The simulated results agree well with the experiment observations,validating the effectiveness of the proposed method.展开更多
An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power a...An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power and retains a small size of 28 mmx16 mmx3 mm. The fabrication process of the silicon substrate and the assembly process of the optical transceiver are demonstrated in details. Moreover, the optical transceiver is measured in order to verify its transmission performance. The clear eye diagrams and the low bit error rate （BER） less than 1013 at 10 Gbit/s per channel show good transmission characteristics of the designed optical transceiver.展开更多
Kenya has a rich mammalian fauna. We reviewed recently published books and papers including the six volumes of Mammals of Africa to develop an up-to-date annotated checklist of all mammals recorded from Kenya. A total...Kenya has a rich mammalian fauna. We reviewed recently published books and papers including the six volumes of Mammals of Africa to develop an up-to-date annotated checklist of all mammals recorded from Kenya. A total of 390 species have been identified in the country, including 106 species of rodents,104 species of bats, 63 species of even-toed ungulates(including whales and dolphins), 36 species of insectivores and carnivores, 19 species of primates,five species of elephant shrews, four species of hyraxes and odd-toed ungulates, three species of afrosoricids, pangolins, and hares, and one species of aardvark, elephant, sirenian and hedgehog. The number of species in this checklist is expected to increase with additional surveys and as the taxonomic status of small mammals(e.g., bats, shrews and rodents) becomes better understood.展开更多
For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carr...For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.展开更多
Ulvan, rhamnan sulfate, was extracted from the edible green seaweed, Ana-aosa (Ulva pertusa), which is grown on the coast of the Okinawa Islands. The yield of ulvan was 8.5% (W/W), and the total carbohydrates, uronic ...Ulvan, rhamnan sulfate, was extracted from the edible green seaweed, Ana-aosa (Ulva pertusa), which is grown on the coast of the Okinawa Islands. The yield of ulvan was 8.5% (W/W), and the total carbohydrates, uronic acid and sulfuric acid and ash contents were 67.3%, 23.8%, 19.7% and 22.6%, respectively. L-Rhamnose, D-xylose and D-glucose residues were identified by liquid chromatography, and their molar ratio was 4.0:0.1:0.3. D-Glucuronic and L-idulonic acid residues were also identified in molar ratio of 1.0:0.2. The NMR (13C and 1H) and methylation analysis revealed terminal β-D-glucruonic acid, terminal α-L-idulonic acid, 1,3-linked α-L-rhamnose, 1,4-linked α-L-rhamnose, 1,2,4-linked α-L-rhamnose, 1,3,4-linked α-L-rhamnose, 1,2,3,4-linked α-L-rhamnose and 1,3,4-linked β-D-xylose. The sulfate groups were attached at the C-2 and C-3 positions of the 1,4-linked α-L-rhamnose as well as C-3 of the 1,4-linked β-D-xylose residues. The chemical structure of the ulvan from Ulva pertusa was determined.展开更多
Staphylinoidea(Insecta:Coleoptera)is one of the most species-rich groups in animals,but its huge diversity can hardly be explained by the popular hypothesis(co-radiation with angiosperms)that applies to phytophagous b...Staphylinoidea(Insecta:Coleoptera)is one of the most species-rich groups in animals,but its huge diversity can hardly be explained by the popular hypothesis(co-radiation with angiosperms)that applies to phytophagous beetles.We estimated the evolutionary mode of staphylinoid beetles and investigated the relationship between the evolutionary mode and palaeoclimate change,and thus the factors underlying the current biodiversity pattern of staphylinoid beetles.Our results demonstrate that staphylinoid beetles originated at around the Triassic-Jurassic bound and the current higher level clades underwent rapid evolution(indicated by increased diversification rate and decreased body size disparity)in the Jurassic and in the Cenozoic,both with low-energy climate,and they evolved much slower during the Cretaceous with high-energy climate.Climate factors,especially low 02 and high C02,promoted the diversification rate and among-clade body size disparification in the Jurassic.In the Cenozoic,however,climate factors had negative associations with diversification rate but little with body size disparification.Our present study does not support the explosion of staphylinoid beetles as a direct outcome of the Cretaceous Terrestrial Revolution(KTR).We suppose that occupying and diversifying in refuge niches associated with litter may elucidate rapid radiations of staphylinoid beetles in low-energy conditions.展开更多
The molecular dynamics method is used to simulate the thermophysical properties of SrTiO3 thermoelectric material in the temperature range 300-2200 K. The Morse-type potential functions added to the Busing-Ida type po...The molecular dynamics method is used to simulate the thermophysical properties of SrTiO3 thermoelectric material in the temperature range 300-2200 K. The Morse-type potential functions added to the Busing-Ida type potential for interatomic interaction are used in the simulation. The interatomic potential parameters are determined by fitting to the experimental data of lattice parameters with temperature and the data reported in literature. The linear thermal expansion coefficient, heat capacity and lattice contributions to the thermal conductivity are analyzed. The results agree with the data reported in the literature.展开更多
The structure-function relationship of a gellan family of polysaccharides, S-198 gum produced by Alcaligenes ATCC31853 was investigated in terms of rheological aspects. The flow curves of S-198 gum showed plastic beha...The structure-function relationship of a gellan family of polysaccharides, S-198 gum produced by Alcaligenes ATCC31853 was investigated in terms of rheological aspects. The flow curves of S-198 gum showed plastic behavior above 0.3%. Gelation did not occur in S-198 gum solution at low temperature (0℃), even at 0.8%. Both the viscosity and the elastic modulus remained constant with increasing temperature up to 80?C. The elastic modulus decreased a little with the addition of CaCl2 (6.8 mM), but then once again remained constant up to 80℃. The highest elastic modulus was observed for deacylated gellan gum with the addition of CaCl2 and increased slightly with increasing temperature up to 80℃, which was considered to be a transition temperature, after which it decreased rapidly. The elastic modulus of S-198 gum in the presence of urea (4.0 M) was lower than that in aqueous solution at low temperature (0℃), but remained constant with increasing temperature up to 80℃. The intramolecular associations, (hydrogen bonding and van der Waals forces of attraction), of S-198 gum molecules in aqueous solutions were proposed. The gellan family of polysaccharides, S-198, S-88, S-657, rhamsan, welan and gellan gum, provided a good opportunity to investigate the structure-function relationship for polysaccharides.展开更多
基金funded by grants from the National Key R&D Project(2023YFD1400201-02,2023YFD1400203-02)the National Natural Science Foundation of China(31870137)+1 种基金the National Transgenic Research Project(2015ZX08001-002)the Key R&D Project of Guangdong Province(2022B0202060005).
文摘Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase allele mining using six updated FNP marker systems,the functional haplotypes at Pit,Pib,and Pi63 strictly diverged into the X-populations and were defined as X-R loci,while those at Pi54,Pi37,and Pi36 into the G-populations as G-R loci.The genic diversity at the three X-R loci(16 alleles)was twofold higher than that at the three G-R loci(8 alleles),and the allelic diversity in the Southern region(21 alleles)was nearly double that in the Northeastern region(11 alleles).Both observations reflect a significant difference in genetic diversity between X-and G-populations,and indicate that the effective R-genes mainly originated from X-subspecies.Based on the allelic structures characterized by a set of 10 parameters,8 and 16 alleles were respectively recognized as favorable and promising ones for the regional breeding programs.The genotypic structures of the two regional populations were almost different,indicating that the diverged alleles have been further assembled into two series of regional genotypes through long-term breeding programs,despite the presence of one-third of region-common alleles.The genotypic diversity in the Southern region(55 genotypes)was nearly twice as high as that in the Northeastern region(28),which perfectly reflects the aforementioned differences in both genic and allelic diversities.After analyzing the genotypic structures using a set of 13 parameters,4 and 23 genotypes,respectively,can be recommended as the favorable and promising ones for the regional breeding programs.The case study serves as a concrete sample of how to identify the favorable and promising alleles and genotypes,and beneficial parents based their comprehensive population structures for gene-designed breeding.
基金supported by grants from the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk0205 to Lin Xia,No.2021xjkk0604 to Jilong Cheng)the National Natural Science Foundation of China(32170416 to Qisen Yang,31900325 to Jilong Cheng)+1 种基金the Joint Fund of National Natural Science Foundation of China(U2003203 to Lin Xia)the Key Laboratory of Zoological Systematics and Evolution of the Chinese Academy of Sciences(Y229YX5105 to Qisen Yang).
文摘How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.
基金supported by the National Natural Science Foundation of China(Grant Nos.:72032006 and 92146005).
文摘Financial market liquidity is a popular research topic.Investor-driven research uses the turnover rate to measure liquidity and generally finds that the higher the stock turnover rate,the lower the returns.However,the traditional financial liquidity theory has been impacted by new machine-driven quantitative trading models.To explore high machine-driven liquidity and the impact of high turnover rates on returns,this study establishes a dual-market quantitative trading system,introduces a variational modal decomposition(VMD)-bidirectional gated recurrent unit(BiGRU)model for data prediction,and uses the back-end Hong Kong foreign exchange market to develop a quantitative trading strategy using the same rotating funds in the U.S.and Chinese stock markets.The experimental results show that given a principal amount of 210,000.00 CNY,the final predicted net return is 226,538.30 CNY,a net return of 107.86%,which is 40.6%higher than the net return of a single Chinese market.We conclude that,under machine-driven trading,increasing liquidity and turnover increase returns.This study provides a new perspective on liquidity theory that is useful for future financial market research and quantitative trading practices.
文摘The publisher regrets that some of the authors’affiliations were mistakenly annotated in the manuscript.Hence,the authors of the below article were contacted after publication to request a correction of the author affliction and responded with the correct by the time this erratum is being published.
基金国家自然科学青年基金项目(31501851)四川大学优秀青年教师名师名校访学项目+9 种基金环保部生物多样性示范监测项目生物安全监测系统应用模拟与示范推广项目(2016YFC12000705)中国科学院国际高级访问学者项目(2011T2S04)National Geographic Society/Waitt FundFunds from the American Philosophical Societythe American Museum of Natural Historythe American Ornithologists’ Unionthe Society for the Study of Evolutionthe Paulson Institutethe Animal Behavior Society等项目
基金Supported by A grant of the Korea Healthcare technology R&D Project, Ministry of Health and Welfare, Republic of Korea (A092258)FG08-11-06 of the 21C Frontier Functional Human Genome Project from the Ministry of Education, Science and Technology
文摘AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined. RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021). CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS) (No. 2016-I2M-1-001)
文摘Objective: To investigate the prognostic value of pretreatment human papillomavirus(HPV) viral load for cervical cancer, and to develop nomograms based on HPV load and other clinicopathological factors for long-term survival.Methods: We conducted a prospective study on cervical squamous cell carcinoma(SCC) patients diagnosed between January 2003 and December 2008. Cervical samples were tested for HPV viral load by the Hybrid Capture II(HCII) assay before treatment and 6 months after treatment. Clinical characteristics and follow-up information were also collected. A multivariable Cox proportional hazards model was used to adjust covariates in both the radical hysterectomy(RH) treatment group and concurrent chemoradiotherapy(CCRT) treatment group to identify relevant covariates, and then nomograms were constructed and used for internal validation.Results: A total of 520 SCC patients enrolled in this study with a median follow-up of 127 months, 360 patients received RH, whereas 160 patients received CCRT. The median HPV viral load in RH and CCRT groups was356.10 and 294.29, respectively. Tumor size was positively correlated with high pretreatment HPV load in both groups. In CCRT group, the advanced International Federation of Gynecology and Obstetrics(FIGO) stage and enlarged retroperitoneal lymph node status determined by computed tomography(LNSCT) were correlated with low HPV load group. Initial HPV viral load, FIGO stage and lymph node metastasis were prognostic factors for RH group, whereas HPV viral load, squamous cell carcinoma antigen(SCC-Ag) level and LNSCT were identified as prognostic factors for CCRT group. Nomograms incorporating these predictors for 10-year progression-free survival(PFS) were constructed [concordance index(C-index): 0.756, 0.749].Conclusions: A low pretreatment HPV viral load is an independent prognostic factor for poor prognosis of cervical SCC and is related to other clinicopathological factors. The survival nomogram based on HPV viral load could predict the long-term prognosis.
基金Supported by Cancer Evolution Research Center(2012 R1A5A2047939),South Korea
文摘Like other solid tumors,colorectal cancer(CRC) is a genomic disorder in which various types of genomic alterations,such as point mutations,genomic rearrangements,gene fusions,or chromosomal copy number alterations,can contribute to the initiation and progression of the disease. The advent of a new DNA sequencing technology known as next-generation sequencing(NGS) has revolutionized the speed and throughput of cataloguing such cancer-related genomic alterations. Now the challenge is how to exploit this advanced technology to better understand the underlying molecular mechanism of colorectal carcinogenesis and to identify clinically relevant genetic biomarkers for diagnosis and personalized therapeutics. In this review,we will introduce NGS-based cancer genomics studies focusing on those of CRC,including a recent large-scale report from the Cancer Genome Atlas. We will mainly discuss how NGS-based exome-,whole genome- and methylome-sequencing have extended our understanding of colorectal carcinogenesis. We will also introduce the unique genomic features of CRC discovered by NGS technologies,such as the relationship with bacterial pathogens and the massive genomic rearrangements of chromothripsis. Finally,we will discuss the necessary steps prior to development of a clinical application of NGS-related findings for the advanced management of patients with CRC.
基金This study was supported by the Basic Research Laboratory of the NRF funded by the Korean Government(grant number 2018R1A4A1022647).
文摘Electrochemical carbon dioxide(CO2)reduction is considered to be an efficient strategy to produce usable fuels and overcome the concerns regarding global warming.For this purpose,an efficient,earth abundant,and a low cost catalyst has to be designed.It has been found that graphene-based materials could be promising candidates for CO2 conversion because of their unique physical,mechanical,and electronic properties.In addition,the surface of graphenebased materials can be modified by using different strategies,including doping,defect engineering,producing composite structures,and wrapping shapes.In this review,the fundamentals of electrochemical CO2 reduction and recent progress of graphene-based catalysts are investigated.Furthermore,recent studies on graphene-based materials for CO2 reduction are summarized.
基金supported by the National Natural Science Foundation of China Granted to Yongjie Wu(No.31501851,31772478)the Chinese Academy of Sciences Visiting Professorship for Senior International Scientists to Per Alstrom(No.2011T2S04)
文摘Background:In biological systems,biological diversity often displays a rapid turn-over across elevations.This defining feature has made mountains classic systems for studying the spatial variation in diversity.Because patterns of elevational diversity can vary among lineages and mountain systems it remains difficult to extrapolate findings from one montane region to another,or among lineages.In this study,we assessed patterns and drivers of avian diversity along an elevational gradient on the eastern slope of Mt.Gongga,the highest peak in the Hengduan Mountain Range in central China,and a mountain where comprehensive studies of avian diversity are still lacking.Methods:We surveyed bird species in eight 400-m elevational bands from 1200 to 4400 m a.s.l.between 2012 and 2017.To test the relationship between bird species richness and environmental factors,we examined the relative importance of seven ecological variables on breeding season distribution patterns:land area(LA),mean daily temperature(MDT),seasonal temperature range(STR),the mid-domain effect(MDE),seasonal precipitation(SP),invertebrate biomass(IB) and enhanced vegetation index(EVI).Climate data were obtained from five local meteorological stations and three temperature/relative humidity smart sensors in 2016.Results:A total of 219 bird species were recorded in the field,of which 204 were recorded during the breeding season(April–August).Species richness curves(calculated separately for total species,large-ranged species,and smallranged species) were all hump-shaped.Large-ranged species contributed more to the total species richness pattern than small-ranged species.EVI and IB were positively correlated with total species richness and small-ranged species richness.LA and MDT were positively correlated with small-ranged species richness,while STR and SP were negatively correlated with small-ranged species richness.MDE was positively correlated with large-ranged species richness.When we considered the combination of candidate factors using multiple regression models and model-averaging,total species richness and large-ranged species richness were correlated with STR(negative) and MDE(positive),while small-ranged species richness was correlated with STR(negative) and IB(positive).Conclusions:Although no single key factor or suite of factors could explain patterns of diversity,we found that MDE,IB and STR play important but varying roles in shaping the elevational richness patterns of different bird species categories.Model-averaging indicates that small-ranged species appear to be mostly influenced by IB,as opposed to large-ranged species,which exhibit patterns more consistent with the MDE model.Our data also indicate that the species richness varied between seasons,offering a promising direction for future work.
文摘The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding between polymer and water molecules, and between water-water molecules even at a concentration range of 0.1% - 1.0% (W/V) at room temperature, resulting in gelation. Such dramatic changes from liquid into gels have been understood at the molecular level in principles. In this review, we describe the structure-function relationship of starch on the view point of rheological aspects and discuss gelatinization and retrogradation mechanism including water molecules at molecular level. The starch molecules (amylose and amylopectin) play a dominant role in the center of the tetrahedral cavities occupied by water molecules, and the arrangement is partially similar to a tetrahedral structure in a gelatinization process. The arrangement should lead to a cooperative effect stabilizing extended regions of ice-like water with hydrogen bonding on the surface of the polymer molecules, where hemiacetal oxygen and hydroxyl groups might participate in hydrogen bonding with water molecules. Thus, a more extended ice-like hydrogen bonding within water molecules might be achieved in a retrogradation process. Though many investigations not only include starch gelatinization and retrogradaion, but also the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, no other researchers have established mechanism at the molecular level. There is reasonable consistency in our investigations.
基金supported by the National Natural Science Foundation of China(No.61533014)the Natural Science Foundation of Shaanxi Province(No.2019JQ-734)。
文摘When preparing large monocrystalline silicon materials,severe carbon etching and silicide deposition often occur to the thermal system.Therefore,a suppression method that optimizes the upper insulation structure has been proposed.Assisted by the finite element method,we calculated temperature distribution and carbon deposition of heater and heat shield,made the rule of silicide and temperature distributing in the system,and we explained the formation of impurity deposition.Our results show that the optimized thermal system reduces carbon etching loss on heat components.The lowered pressure of the furnace brings a rapid decrease of silicide deposition.The increase of the argon flow rate effectively inhibits CO and back diffusion.The simulated results agree well with the experiment observations,validating the effectiveness of the proposed method.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016904)
文摘An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power and retains a small size of 28 mmx16 mmx3 mm. The fabrication process of the silicon substrate and the assembly process of the optical transceiver are demonstrated in details. Moreover, the optical transceiver is measured in order to verify its transmission performance. The clear eye diagrams and the low bit error rate （BER） less than 1013 at 10 Gbit/s per channel show good transmission characteristics of the designed optical transceiver.
基金supported by the Sino-Africa Joint Research Centre,Chinese Academy of Sciences(SAJC201612)
文摘Kenya has a rich mammalian fauna. We reviewed recently published books and papers including the six volumes of Mammals of Africa to develop an up-to-date annotated checklist of all mammals recorded from Kenya. A total of 390 species have been identified in the country, including 106 species of rodents,104 species of bats, 63 species of even-toed ungulates(including whales and dolphins), 36 species of insectivores and carnivores, 19 species of primates,five species of elephant shrews, four species of hyraxes and odd-toed ungulates, three species of afrosoricids, pangolins, and hares, and one species of aardvark, elephant, sirenian and hedgehog. The number of species in this checklist is expected to increase with additional surveys and as the taxonomic status of small mammals(e.g., bats, shrews and rodents) becomes better understood.
文摘For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.
文摘Ulvan, rhamnan sulfate, was extracted from the edible green seaweed, Ana-aosa (Ulva pertusa), which is grown on the coast of the Okinawa Islands. The yield of ulvan was 8.5% (W/W), and the total carbohydrates, uronic acid and sulfuric acid and ash contents were 67.3%, 23.8%, 19.7% and 22.6%, respectively. L-Rhamnose, D-xylose and D-glucose residues were identified by liquid chromatography, and their molar ratio was 4.0:0.1:0.3. D-Glucuronic and L-idulonic acid residues were also identified in molar ratio of 1.0:0.2. The NMR (13C and 1H) and methylation analysis revealed terminal β-D-glucruonic acid, terminal α-L-idulonic acid, 1,3-linked α-L-rhamnose, 1,4-linked α-L-rhamnose, 1,2,4-linked α-L-rhamnose, 1,3,4-linked α-L-rhamnose, 1,2,3,4-linked α-L-rhamnose and 1,3,4-linked β-D-xylose. The sulfate groups were attached at the C-2 and C-3 positions of the 1,4-linked α-L-rhamnose as well as C-3 of the 1,4-linked β-D-xylose residues. The chemical structure of the ulvan from Ulva pertusa was determined.
基金the National Natural Science Foundation of China(NSFC-31501883 to L.L.,NSFC-31472036 to H.-Z.Z.)the Youth Top-notch Talent Support Program of Hebei Province to L.L.(BJ2018057)+2 种基金the Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment,China to H.-Z.Z.(2019H J2096001006)a grant from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences to H.-Z.Z(Y 229Y X5105)a grant from the Strategic Priority Research Program of the Chinese Academy of Sciences to CY.C.(XD B26000000).
文摘Staphylinoidea(Insecta:Coleoptera)is one of the most species-rich groups in animals,but its huge diversity can hardly be explained by the popular hypothesis(co-radiation with angiosperms)that applies to phytophagous beetles.We estimated the evolutionary mode of staphylinoid beetles and investigated the relationship between the evolutionary mode and palaeoclimate change,and thus the factors underlying the current biodiversity pattern of staphylinoid beetles.Our results demonstrate that staphylinoid beetles originated at around the Triassic-Jurassic bound and the current higher level clades underwent rapid evolution(indicated by increased diversification rate and decreased body size disparity)in the Jurassic and in the Cenozoic,both with low-energy climate,and they evolved much slower during the Cretaceous with high-energy climate.Climate factors,especially low 02 and high C02,promoted the diversification rate and among-clade body size disparification in the Jurassic.In the Cenozoic,however,climate factors had negative associations with diversification rate but little with body size disparification.Our present study does not support the explosion of staphylinoid beetles as a direct outcome of the Cretaceous Terrestrial Revolution(KTR).We suppose that occupying and diversifying in refuge niches associated with litter may elucidate rapid radiations of staphylinoid beetles in low-energy conditions.
文摘The molecular dynamics method is used to simulate the thermophysical properties of SrTiO3 thermoelectric material in the temperature range 300-2200 K. The Morse-type potential functions added to the Busing-Ida type potential for interatomic interaction are used in the simulation. The interatomic potential parameters are determined by fitting to the experimental data of lattice parameters with temperature and the data reported in literature. The linear thermal expansion coefficient, heat capacity and lattice contributions to the thermal conductivity are analyzed. The results agree with the data reported in the literature.
文摘The structure-function relationship of a gellan family of polysaccharides, S-198 gum produced by Alcaligenes ATCC31853 was investigated in terms of rheological aspects. The flow curves of S-198 gum showed plastic behavior above 0.3%. Gelation did not occur in S-198 gum solution at low temperature (0℃), even at 0.8%. Both the viscosity and the elastic modulus remained constant with increasing temperature up to 80?C. The elastic modulus decreased a little with the addition of CaCl2 (6.8 mM), but then once again remained constant up to 80℃. The highest elastic modulus was observed for deacylated gellan gum with the addition of CaCl2 and increased slightly with increasing temperature up to 80℃, which was considered to be a transition temperature, after which it decreased rapidly. The elastic modulus of S-198 gum in the presence of urea (4.0 M) was lower than that in aqueous solution at low temperature (0℃), but remained constant with increasing temperature up to 80℃. The intramolecular associations, (hydrogen bonding and van der Waals forces of attraction), of S-198 gum molecules in aqueous solutions were proposed. The gellan family of polysaccharides, S-198, S-88, S-657, rhamsan, welan and gellan gum, provided a good opportunity to investigate the structure-function relationship for polysaccharides.
