Comparative Transcriptomic Analysis Provides Novel Insights into the Blanched Stem of Oenanthe javanica

In the agricultural field, blanching is a technique used to obtain tender, sweet, and delicious water dropwort stems by blocking sunlight. The physiological and nutritional parameters of blanched water dropwort have been previously investigated. However, the molecular mechanism of blanching remains unclear. In the present study, we investigated transcriptomic variations for different blanching periods in the stem of water dropwort (pre, mid, post-blanching, and control). The results showed that many genes in pathways, such as photosynthesis, carbon fixation, and phytohormone signal transduction as well as transcription factors (TFs) were significantly dysregulated. Blanched stems of water dropwort showed the higher number of downregulated genes in pathways, such as photosynthesis, antenna protein, carbon fixation in photosynthetic organisms, and porphyrin and chlorophyll metabolism, which ultimately affect the photosynthesis in water dropwort. The genes of hormone signal transduction pathways (ethylene, jasmonic acid, brassinosteroid, and indole-3-acetic acid) showed upregulation in the post-blanched water dropwort plants. Overall, a higher number of genes coding for TFs, such as ERF, BHLH, MYB, zinc-finger, bZIP, and WRKY were overexpressed in blanched samples in comparison with the control. These genes and pathways participate in inducing the length, developmental processes, pale color, and stress tolerance of the blanched stem. Overall, the genes responsive to blanching, which were identified in this study, provide an effective foundation for further studies on the molecular mechanisms of blanching and photosynthesis regulations in water dropwort and other species.

Corrigendum: Phenotypic, Nutritional, and Antioxidant Characterization of Blanched Oenanthe javanica for Preferable Cultivar

[This corrects the article DOI: 10.3389/fpls.2021.639639.].

Uncovering phylogenetic relationships and genetic diversity of water dropwort using phenotypic traits and SNP markers

The water dropworts Oenanthe linearis Wall. ex DC. and O. javanica (Blume) DC. are aquatic perennial herbs that have been used in China as vegetables and traditional medicines. However, their phylogenetic relationships and genetic diversity are poorly understood. Here, we presented the phenotypic traits and genome-wide DNA marker-based analysis of 158 water dropwort accessions representing both species. The analysis revealed that Oenanthe linearis was readily segregated into linear-leaf and deep-cleft leaf water dropworts according to their leaf shapes at flowering. Oenanthe javanica was classified by clustering analysis into two clusters based mainly on the morphological characteristics of their ultimate segments (leaflets). A set of 11 493 high-quality single-nucleotide polymorphisms was identified and used to construct a phylogenetic tree. There was strong discrimination between O. linearis and O. javanica, which was consistent with their phenotype diversification. The population structure and phylogenetic tree analyses suggested that the O. linearis accessions formed two major groups, corresponding to the linear-leaf and deep-cleft leaf types. The most obvious phenotypic differences between them were fully expressed at the reproductive growth stage. A single-nucleotide polymorphism-based analysis revealed that the O. javanica accessions could be categorized into groups I andII. However, this finding did not entirely align with the clusters revealed by morphological classification. Landraces were clustered into one group along with the remaining wild accessions. Hence, water dropwort domestication was short in duration. The level of genetic diversity for O. linearis (π = 0.1902) was slightly lower than that which was estimated for O. javanica (π = 0.2174). There was a low level of genetic differentiation between O. linearis and O. javanica (Fst = 0.0471). The mean genetic diversity among accessions ranged from 0.1818 for the linear-leaf types to 0.2318 for the groupII accessions. The phenotypic traits and the single-nucleotide polymorphism markers identified here lay empirical foundation for future genomic studies on water dropwort.

Effect of Salt Stress on Growth, Physiological Parameters, and Ionic Concentration of Water Dropwort (Oenanthe javanica) Cultivars

Salt stress is an important environmental limiting factor. Water dropwort (Oenanthe javanica) is an important vegetable in East Asia; however, its phenotypic and physiological response is poorly explored. For this purpose, 48 cultivars of water dropwort were grown hydroponically and treated with 0, 50, 100, and 200 mm NaCl for 14 days. Than their phenotypic responses were evaluated, afterward, physiological studies were carried out in selected sensitive and tolerant cultivars. In the present study, the potential tolerant (V11E0022) and sensitive (V11E0135) cultivars were selected by screening 48 cultivars based on their phenotype under four different levels of salt concentrations (0, 50, 100, and 200 mm). The results depicted that plant height, number of branches and leaves were less effected in V11E0022, and most severe reduction was observed in V11E0135 in comparison with others. Than the changes in biomass, ion contents, accumulation of reactive oxygen species, and activities of antioxidant enzymes and non-enzymatic antioxidants were determined in the leaves and roots of the selected cultivars. The potential tolerant cultivar (V11E0022) showed less reduction of water content and demonstrated low levels of Na+ uptake, malondialdehyde, and hydrogen peroxide (H2O2) in both leaves and roots. Moreover, the tolerant cultivar (V11E0022) showed high antioxidant activities of ascorbate peroxidase (APX), superoxide dismutase, peroxidase, catalase (CAT), reduced glutathione (GSH), and high accumulation of proline and soluble sugars compared to the sensitive cultivar (V11E0135). These results suggest the potential tolerance of V11E0022 cultivar against salt stress with low detrimental effects and a good antioxidant defense system. The observations also suggest good antioxidant capacity of water dropwort against salt stress. The findings of the present study also suggest that the number of branches and leaves, GSH, proline, soluble sugars, APX, and CAT could serve as the efficient markers for understanding the defense mechanisms of water dropwort under the conditions of salt stress.

Phenomenological Constraints on the Transport Properties of QCD Matter with Data-Driven Model Averaging

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼150-350  MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.

Phenotypic, Nutritional, and Antioxidant Characterization of Blanched Oenanthe javanica for Preferable Cultivar

Blanching is a technique used in blocking sunlight for the production of tender, sweet, and delicious stems in the field. This technique is also used in water dropwort (Oenanthe javanica), an important vegetable in East Asia. In China, the steamed stems of water dropwort are prepared with boiled rice. However, the effect of blanching on the nutritional level and antioxidant capacity of water dropwort has not been explored yet. The current study aims to determine the nutrient contents and antioxidant capacities of five cultivars and select the best cultivar. They were mainly compared in terms of phenotypic, physiological, nutritional, and antioxidant levels after blanch cultivation. Results indicate that blanching significantly influenced the phenotype, physiology, and nutritional level of water dropwort in all cultivars. Although few parameters decreased with blanching, starch, sugars, vitamins, minerals, and antioxidant activities increased significantly in the blanched stems in mid- and post-blanching periods. The most noticeable changes were detected in post-blanching samples. Furthermore, the best cultivar (V11E0012) was identified among them. Therefore, blanched water dropwort could be consumed for achieving more nutraceuticals and antioxidants, and cultivar V11E0012 could be recommend for blanching cultivation.

Nanotechnology for catalysis and solar energy conversion

This roadmap on Nanotechnology for Catalysis and Solar Energy Conversion focuses on the application of nanotechnology in addressing the current challenges of energy conversion: 'high efficiency, stability, safety, and the potential for low-cost/scalable manufacturing' to quote from the contributed article by Nathan Lewis. This roadmap focuses on solar-to-fuel conversion, solar water splitting, solar photovoltaics and bio-catalysis. It includes dye-sensitized solar cells (DSSCs), perovskite solar cells, and organic photovoltaics. Smart engineering of colloidal quantum materials and nanostructured electrodes will improve solar-to-fuel conversion efficiency, as described in the articles by Waiskopf and Banin and Meyer. Semiconductor nanoparticles will also improve solar energy conversion efficiency, as discussed by Boschloo et al in their article on DSSCs. Perovskite solar cells have advanced rapidly in recent years, including new ideas on 2D and 3D hybrid halide perovskites, as described by Spanopoulos et al 'Next generation' solar cells using multiple exciton generation (MEG) from hot carriers, described in the article by Nozik and Beard, could lead to remarkable improvement in photovoltaic efficiency by using quantization effects in semiconductor nanostructures (quantum dots, wires or wells). These challenges will not be met without simultaneous improvement in nanoscale characterization methods. Terahertz spectroscopy, discussed in the article by Milot et al is one example of a method that is overcoming the difficulties associated with nanoscale materials characterization by avoiding electrical contacts to nanoparticles, allowing characterization during device operation, and enabling characterization of a single nanoparticle. Besides experimental advances, computational science is also meeting the challenges of nanomaterials synthesis. The article by Kohlstedt and Schatz discusses the computational frameworks being used to predict structure-property relationships in materials and devices, including machine learning methods, with an emphasis on organic photovoltaics. The contribution by Megarity and Armstrong presents the 'electrochemical leaf' for improvements in electrochemistry and beyond. In addition, biohybrid approaches can take advantage of efficient and specific enzyme catalysts. These articles present the nanoscience and technology at the forefront of renewable energy development that will have significant benefits to society.

Genetic diversity and population structure of eddoe taro in China using genome-wide SNP markers

Taro (Colocasia esculenta) is an important root and tuber crop cultivated worldwide. There are two main types of taro that vary in morphology of corm and cormel, ‘dasheen’ and ‘eddoe’. The eddoe type (Colocasia esculenta var. antiquorium) is predominantly distributed throughout China. Characterizing the genetic diversity present in the germplasm bank of taro is fundamental to better manage, conserve and utilize the genetic resources of this species. In this study, the genetic diversity of 234 taro accessions from 16 provinces of China was assessed using 132,869 single nucleotide polymorphism (SNP) markers identified by specific length amplified fragment-sequencing (SLAF-seq). Population structure and principal component analysis permitted the accessions to be categorized into eight groups. The genetic diversity and population differentiation of the eight groups were evaluated using the characterized SNPs. Analysis of molecular variance showed that the variation among eight inferred groups was higher than that within groups, while a relatively small variance was found among the two morphological types and 16 collection regions. Further, a core germplasm set comprising 41 taro accessions that maintained the genetic diversity of the entire collection was developed based on the genotype. This research is expected to be valuable for genetic characterization, germplasm conservation, and breeding of taro.

Resequencing of 296 cultivated and wild lotus accessions unravels its evolution and breeding history

Lotus (family: Nelumbonaceae) are perennial aquatic plants that represent one of the most ancient basal dicots. In the present study, we resequenced 296 lotus accessions from various geographical locations and germplasms to explore their genomic diversity and population structure. This germplasm set consisted of four accessions of American wild lotus and 292 accessions of Asian lotus, which were divided into four subgroups: wild, rhizome, flower and seed. Total single nucleotide polymorphisms (SNPs) suggested that the wild lotus had the highest variant number (7 191 010). Population structure and genome diversity analysis indicated that the American wild lotus demonstrated a distant genetic relationship with the Asian lotus. Furthermore, the seed and rhizome lotus groups had not originated from a single source but rather had a more complex multisource origin. Besides that, the seed lotus showed higher genetic diversity, which might have been due to the gene flow from the flower lotus to seed lotus by artificial crossing, and the rhizome lotus showed a much lower genetic diversity than the other groups. The present study provides SNP markers for lotus genomic diversity analysis, which will be useful for guiding lotus breeding.

Construction of a high-density, high-quality genetic map of cultivated lotus (Nelumbo nucifera) using next-generation sequencing

BACKGROUND

The sacred lotus (Nelumbo nucifera) is widely cultivated in China for its edible rhizomes and seeds. Traditional plant breeding methods have been used to breed cultivars with increased yields and quality of rhizomes and seeds with limited success. Currently, the available genetic maps and molecular markers in lotus are too limited to be useful for molecular genetics based breeding programs. However, the development of next-generation sequencing (NGS) technologies has enabled large-scale identification of single-nucleotide polymorphisms (SNPs) for genetic map construction. In this study, we constructed an SNP-based high-density genetic map for cultivated lotus using double digest restriction site-associated DNA sequencing (ddRADseq).

RESULTS

An F2 population of 96 individuals was derived from a cross between the rhizome lotus cultivar 'Juwuba' (male parent) and the seed lotus cultivar 'Mantianxing' (female parent). Genomic DNAs from this population were digested with the restriction enzymes EcoRI and MspI and then sequenced. In total, 133.65 Gb of raw data containing 1,088,935,610 pair-end reads were obtained. The coverage of reads on a reference genome was 7.2 % for the female parent, 6.56 % for the male parent, and 1.46 % for F2 individuals. From these reads, 10,753 valid SNP markers were used for genetic map construction. Finally, 791 bin markers (so-segregated adjacent SNPs treated as a bin marker), consisting of 8,971 SNP markers, were sorted into 8 linkage groups (LGs) that spanned 581.3 cM, with an average marker interval of 0.74 cM. A total of 809 genome sequence scaffolds, covering about 565.9 cM of the wild sacred lotus genome, were anchored on the genetic map, accounting for 70.6 % of the genome assembly.

CONCLUSIONS

This study reports the large-scale discovery of SNPs between cultivars of rhizome and seed lotus using a ddRADseq library combined with NGS. These SNPs have been used to construct the first high-density genetic map for cultivated lotus that can serve as a genomic reference and will facilitate genetic mapping of important traits in the parental cultivars.

Genome-Wide Identification of SSR and SNP Markers Based on Whole-Genome Re-Sequencing of a Thailand Wild Sacred Lotus (Nelumbo nucifera)

Genomic resources such as single nucleotide polymorphism (SNPs), insertions and deletions (InDels) and SSRs (simple sequence repeats) are essential for crop improvement and better utilization in genetic breeding. However, the resources for the sacred lotus (Nelumbo nucifera Gaertn.) are still limited. In the present study, to dissect large-scale genomic molecular marker resources for sacred lotus, we re-sequenced a Thailand sacred lotus cultivar ‘Chiang Mai wild lotus’ and compared with the reported lotus genome ‘Middle lake wild lotus’. A total of 3,180,059 SNPs, 328, 251 InDels and 14,191 SVs were found between the two genomes. The functional impact analyses of these SNPs indicated that they may be involved in metabolic processes, binding, catalytic activity, etc. Mining the genome sequences for SSRs showed that 191,657 SSRs were identified with a frequency of one SSR per 4.23 kb and 103,656 SSR primer pairs were designed. Furthermore, 14, 502 EST-SSRs were also indentified using the available RNA-seq data in the NCBI. A subset of 150 SSRs (genomic and EST-SSRs) was randomly selected for validation and genetic diversity analysis. The genotypes could be easily distinguished using these SSR markers and the ‘Chiang Mai wild lotus’ was obviously differentiated from the other Chinese accessions. This study provides considerable amounts of genomic resources and markers for the quantitative trait locus (QTL) identification and molecular selection of the species, which could have a potential role in various applications in sacred lotus breeding.

Transcriptomic Analysis of the Regulation of Rhizome Formation in Temperate and Tropical Lotus (Nelumbo nucifera)

Rhizome is the storage organ of lotus derived from modified stems. The development of rhizome is a complex process and depends on the balanced expression of the genes that is controlled by environmental and endogenous factors. However, little is known about the mechanism that regulates rhizome girth enlargement. In this study, using RNA-seq, transcriptomic analyses were performed at three rhizome developmental stages-the stolon, middle swelling and later swelling stage -in the cultivars 'ZO' (temperate lotus with enlarged rhizome) and 'RL' (tropical lotus with stolon). About 348 million high-quality reads were generated, and 88.5% of the data were mapped to the reference genome. Of 26783 genes identified, 24069 genes were previously predicted in the reference, and 2714 genes were novel transcripts. Moreover, 8821 genes were differentially expressed between the cultivars at the three stages. Functional analysis identified that these genes were significantly enriched in pathways carbohydrate metabolism and plant hormone signal transduction. Twenty-two genes involved in photoperiod pathway, starch metabolism and hormone signal transduction were candidate genes inducing rhizome girth enlargement. Comparative transcriptomic analysis detected several differentially expressed genes and potential candidate genes required for rhizome girth enlargement, which lay a foundation for future studies on molecular mechanisms underlying rhizome formation.

A precise chloroplast genome of Nelumbo nucifera (Nelumbonaceae) evaluated with Sanger, Illumina MiSeq, and PacBio RS II sequencing platforms: insight into the plastid evolution of basal eudicots

BACKGROUND

The chloroplast genome is important for plant development and plant evolution. Nelumbo nucifera is one member of relict plants surviving from the late Cretaceous. Recently, a new sequencing platform PacBio RS II, known as 'SMRT (Single Molecule, Real-Time) sequencing', has been developed. Using the SMRT sequencing to investigate the chloroplast genome of N. nucifera will help to elucidate the plastid evolution of basal eudicots.

RESULTS

The sizes of the de novo assembled complete chloroplast genome of N. nucifera were 163,307 bp, 163,747 bp and 163,600 bp with average depths of coverage of 7×, 712× and 105× sequenced by Sanger, Illumina MiSeq and PacBio RS II, respectively. The precise chloroplast genome of N. nucifera was obtained from PacBio RS II data proofread by Illumina MiSeq reads, with a quadripartite structure containing a large single copy region (91,846 bp) and a small single copy region (19,626 bp) separated by two inverted repeat regions (26,064 bp). The genome contains 113 different genes, including four distinct rRNAs, 30 distinct tRNAs and 79 distinct peptide-coding genes. A phylogenetic analysis of 133 taxa from 56 orders indicated that Nelumbo with an age of 177 million years is a sister clade to Platanus, which belongs to the basal eudicots. Basal eudicots began to emerge during the early Jurassic with estimated divergence times at 197 million years using MCMCTree. IR expansions/contractions within the basal eudicots seem to have occurred independently.

CONCLUSIONS

Because of long reads and lack of bias in coverage of AT-rich regions, PacBio RS II showed a great promise for highly accurate 'finished' genomes, especially for a de novo assembly of genomes. N. nucifera is one member of basal eudicots, however, evolutionary analyses of IR structural variations of N. nucifera and other basal eudicots suggested that IR expansions/contractions occurred independently in these basal eudicots or were caused by independent insertions and deletions. The precise chloroplast genome of N. nucifera will present new information for structural variation of chloroplast genomes and provide new insight into the evolution of basal eudicots at the primary sequence and structural level.

Microscopic contact area and friction between medical textiles and skin

The mechanical contact between medical textiles and skin is relevant in the health care for patients with vulnerable skin or chronic wounds. In order to gain new insights into the skin-textile contact on the microscopic level, the 3D surface topography of a normal and a new hospital bed sheet with a regular surface structure was measured using a digital microscope. The topographic data was analysed concerning material distribution and real contact area against smooth surfaces as a function of surface deformations. For contact conditions that are relevant for the skin of patients lying in a hospital bed it was found that the order of magnitude of the ratio of real and apparent contact area between textiles and skin or a mechanical skin model lies between 0.02 and 0.1 and that surface deformations, i.e. penetration of the textile surface asperities into skin or a mechanical skin model, range from 10 to 50µm. The performed analyses of textile 3D surface topographies and comparisons with previous friction measurement results provided information on the relationship between microscopic surface properties and macroscopic friction behaviour of medical textiles. In particular, the new bed sheet was found to be characterised by a trend towards a smaller microscopic contact area (up to a factor of two) and by a larger free interfacial volume (more than a factor of two) in addition to a 1.5 times lower shear strength when in contact with counter-surfaces. The applied methods can be useful to develop improved and skin-adapted materials and surfaces for medical applications.

The sacred lotus genome provides insights into the evolution of flowering plants

Sacred lotus (Nelumbo nucifera) is an ornamental plant that is also used for food and medicine. This basal eudicot species is especially important from an evolutionary perspective, as it occupies a critical phylogenetic position in flowering plants. Here we report the draft genome of a wild strain of sacred lotus. The assembled genome is 792 Mb, which is approximately 85-90% of genome size estimates. We annotated 392 Mb of repeat sequences and 36,385 protein-coding genes within the genome. Using these sequence data, we constructed a phylogenetic tree and confirmed the basal location of sacred lotus within eudicots. Importantly, we found evidence for a relatively recent whole-genome duplication event; any indication of the ancient paleo-hexaploid event was, however, absent. Genomic analysis revealed evidence of positive selection within 28 embryo-defective genes and one annexin gene that may be related to the long-term viability of sacred lotus seed. We also identified a significant expansion of starch synthase genes, which probably elevated starch levels within the rhizome of sacred lotus. Sequencing this strain of sacred lotus thus provided important insights into the evolution of flowering plant and revealed genetic mechanisms that influence seed dormancy and starch synthesis.

Numerical and experimental analysis of the critically refracted longitudinal beam

The critically refracted longitudinal (L(CR)) wave can be used in numerous non-destructive testing (NDT) applications, such as characterization of surface geometric aspects, subsurface defect detection and mostly for residual stress measurement. However, very few works characterize the associated ultrasonic beam. This paper deals with characterization of the L(CR) beam profile both numerically and experimentally in order to optimize the incident angle choice in order to have sufficient energy in the experimental signal. The simulations are performed in time and frequency domains concerning solid elastic, homogenous and isotropic materials taking into account the liquid-solid interaction of the excitation by a water-coupled transducer. In the obtained results all components of the refracted acoustical field are demonstrated, as well as energy distributions of L(CR) wave obtained with different incident angles.

Comparative analysis of genetic diversity in sacred lotus (Nelumbo nucifera Gaertn.) using AFLP and SSR markers

The sacred lotus (Nelumbo nucifera Gaertn.) is an aquatic plant of economic and ornamental importance in China. In this study, we developed twenty novel sacred lotus SSR markers, and used AFLP and SSR markers to investigate the genetic diversity and genetic relationships among 58 accessions of N. nucifera including 15 seed lotus, 12 rhizome lotus, 24 flower lotus and 7 wild lotus. Our results showed that sacred lotus exhibited a low level of genetic diversity, which may attribute to asexual reproduction and long-term artificial selection. A dendrogram based on both AFLP and SSR clustering data showed that: (1) the seed lotus accessions and rhizome lotus accessions were distinctly clustered into different groups, which indicated the significant genetic differentiation between them. This may be attributed to the two modes of reproduction and lack of genetic exchange; (2) the accessions of Thailand wild lotus were separated from other wild lotus accessions. This implied that the Thailand lotus might be genetically differentiated from other wild lotuses. In addition, Mantel test conducted gave highly significant correlation between AFLP-SSR data and each of the AFLP and SSR ones, with the values of r = 0.941 and r = 0.879, respectively, indicating the higher efficiency of the combination of these techniques (AFLP and SSR) in estimation and validation of the genetic diversity among the accession of sacred lotus. This knowledge of the genetic diversity and genetic relatedness of N. nucifera is potentially useful to improve the current strategies in breeding and germplasm conservation to enhance the ornamental and economic value of sacred lotus.

Permanent Genetic Resources added to the Molecular Ecology Resources Database 1 February 2010-31 March 2010

This article documents the addition of 228 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anser cygnoides, Apodemus flavicollis, Athene noctua, Cercis canadensis, Glis glis, Gubernatrix cristata, Haliotis tuberculata, Helianthus maximiliani, Laricobius nigrinus, Laricobius rubidus, Neoheligmonella granjoni, Nephrops norvegicus, Oenanthe javanica, Paramuricea clavata, Pyrrhura orcesi and Samanea saman. These loci were cross-tested on the following species: Apodemus sylvaticus, Laricobius laticollis and Laricobius osakensis (a proposed new species currently being described).

Development of novel EST-SSRs from sacred lotus (Nelumbo nucifera Gaertn) and their utilization for the genetic diversity analysis of N. nucifera

Expressed sequence tags (ESTs) provide a valuable resource for the development of simple sequence repeat (SSR) or microsatellite markers. This study identified SSRs within ESTs from Nelumbo nucifera (lotus or sacred lotus), developed markers from them, and assessed the potential of those markers for diversity analysis. Within 2207 ESTs from N. nucifera downloaded from GenBank, 1483 unigenes (303 contigs and 1180 singletons) were identified. After eliminating for redundancy, 125 SSR-containing ESTs were derived, and 71 unique SSRs were detected with an average density of one SSR per 13.04 kb. Dinucleotide repeats were the dominant motif in N. nucifera, whereas the sequences AG/TC/GA/CT, AAG/TTC/GAT/AGA, and AAAGCC were the most frequent of di-, tri-, and hexanucleotide motifs, respectively. The AG/TC (40.85%) and AAG (5.63%) motifs were predominant for the di- and trinucleotide repeats, respectively. Sixty-two SSR-containing ESTs were suitable for primer design. From these sequences, 23 EST-SSR markers were developed and were applied to 39 cultivated varieties of N. nucifera, 10 accessions of wild N. nucifera, and 1 accession of Nelumbo lutea (American lotus). Genetic diversity and genetic relationships were examined by constructing unweighted pair-group method with arithmetic average dendrograms and principal coordinates analysis plots based on SSR polymorphisms. Results indicated genetic differentiation between cultivated and wild lotus and between seed lotus cultivars and rhizome lotus cultivars. These EST-SSR markers will be useful for further studies of the evolution and diversity of Nelumbo.

Sixteen polymorphic microsatellite markers from Zizania latifolia Turcz. (Poaceae)

Sixteen polymorphic microsatellite markers were isolated and identified in Zizania latifolia Turcz. (Poaceae), a perennial aquatic plant widespread in Eastern Asia. The microsatellite-enriched library was constructed using the fast isolation by AFLP of sequences containing repeats method. These markers revealed two to 14 alleles, with an average of 5.6 alleles per locus. The observed and expected heterozygosities varied from 0.071 to 0.690 and from 0.174 to 0.812, respectively. These markers will be useful for studying of gene flow and evaluating the genetic diversity of the Zizania latifolia population.

Polymorphic microsatellite markers in Euryale ferox Salisb. (Nymphaeaceae)

Eleven polymorphic microsatellite markers were isolated and identified in the aquatic plant Euryale ferox Salisb. (Nymphaeaceae). This species, which belongs to basal Magnoliophyta, reproduces sexually. All of these 11 microsatellite markers yielded 25 alleles in a survey of a wild population of 34 individuals. Two or three alleles per locus were detected, with expected heterozygosity ranging from 0.056 to 0.634 and observed heterozygosity from 0.000 to 0.088. These simple sequence repeat markers will be useful for evaluating the genetic structure of the E. ferox population in the future.

Urolithiasis in pediatric patients with acute lymphoblastic leukemia

We evaluated the incidence, timing, and consequences of urolithiasis in children with acute lymphoblastic leukemia (ALL). A total of 20 patients with urolithiasis were identified from 2095 patients with ALL treated at St Jude Children's Research Hospital on consecutive protocols between 1968 and 1998. For remission induction therapy, all patients received daily prednisone; continuation chemotherapy regimens differed by protocol with some including pulses of prednisone or dexamethasone and others no glucocorticoid. Patients with urolithiasis were older at diagnosis of ALL than those without urolithiasis (median age, 7.5 vs 5.0 years; P=0.03) and less likely to be black (P=0.03) than white or Hispanic, but sex and treatment era did not differ. Presenting symptoms included abdominal or flank pain, hematuria, and dysuria. All stones analyzed biochemically were calcium stones. The incidence of urolithiasis after completion of therapy was 1.8 per 10 000 person-years. Compared to this baseline rate, the relative risk of urolithiasis was 45 (P<0.01) during induction therapy, 22 (P<0.01) during continuation therapy with glucocorticoids, and 5.1 (P>0.05) during continuation therapy without glucocorticoids. Urolithiasis occurred 4.5 times more often during continuation treatment with glucocorticoids than without (P<0.05). Seven patients (35%) had recurrent urolithiasis. Patients with ALL are at risk of developing calcium renal stones during chemotherapy, especially when a glucocorticoid is included.

Sustained-release effect of codried excipients of microcrystalline cellulose and Ganoderma fiber

The sustained-release effects of codried excipient of modified Ganoderma (treated with alkaline solution) and microcrystalline cellulose at different ratios were examined using acetaminophen (ACT) as a model drug. Results demonstrate that the crushing strength of most ACT tablets made with codried powder at all ratios increased as compaction force increased; but a rapid decline was observed when compression force exceeded 2 tons. Drug release from tablets compressed at 0.5 ton increased as modified Ganoderma fiber content increased. But when the compression force exceeded 1 ton, the release rate was not influenced by the compaction force or the increasing content of Ganoderma fiber. However, the dissolution of ACT from these tablets could be sustained for longer than 24 h. The extent of drug release was shown to increase with increasing amounts of modified Ganoderma in the codried excipient. The addition of disintegrants could further accelerate the drug release from the tablet. Drug release was also dependent upon the amount and kind of disintegrant used. The influence was in the following order: primojel>crospovidone>starch 1500.

[Poison effect of plant granules on Oncomelania hupensis]

Plant granules (phi 2-3 mm) made of starch, gelatin and medicine plant powder were used to kill Oncomelania hupensis. The results showed that after eating the plant granules, the mortality of the snail was 92.5%-100% within 24 hrs. The poison effect of the plant granules was much better than that of others, e.g., they could kill snails 12-24 h earlier than Niclosamidum (1 x 10(-3) g.L-1). In a field experiment, the snail mortality was up to 61.5% by using plant granules.

[Effect of Nerium indicum on killing Oncomelania hupensis]

A laboratory experiment at 20 +/- 5 degrees C shows that the water extract of fresh Nerium indicum had an obvious effect on killing Oncomelania hupensis. Treated with 0.1% water extract for four days, the mortality of O. hupensis was up to 100%. The effect of different tissues of N. indicum on O. hupensis was in order of stem phloem > leaf > root phloem > flower. The effect of N. indicum on O. hupensis was about ten times higher than that of Pterocarya stenoptera and Rumex japonicus, and was equal to that of 1 x 10(-3) mg.L-1 niclosamidum.

[Damage mechanisms of molecule in DNA aqueous solution induced by ultraviolet radiation]

After ultraviolet radiation treated at various time, the Raman spectra of herring sperm DNA in aqueous solution were presented. The analytic results showed that first, the out-ring amino group numeration of cytosine C4 site have reducing in the form of Raman hypochromicity; but C4O ketone group of derivative uracil assumed have not emerge with Raman hyperchromiciuy, in UV-induced DNA only with water molecule join in; second, the electron cloud of the main-groove side in pyrimidine ring have a tendency of slanting toward C6 site, which was beneficial to the deamination of C-->U transition, after some cytosine formed dipyrimidine with another adjacent pyrimidine; and third, with UV radiation, the characteristic peak 616 cm-1 of uracil N3C4 has arisen. Its very important, because the quality of the N3C4 bond have a great difference between cytosine and uracil. The result have not supported the model that cytosine can direct to be come off amino group for form the ketone type uracilo depend on UV-induced, therefore we have found that the process of get involved in imino tautomer state was probable exist by Raman spectroscopic technique.

[Characteristic of vibration spectra for hydration state of herring sperm DNA fibers]

By different temperature treatment, the herring sperm DNA fibers at various relative humidity have been analyzed using Raman scattering spectroscopic method for estimation of bound water content in fiber according to the typical peak intensity ratio between deoxyribosyl C-H stretching vibration (at 2964cm(-1)) and bound water O-H stretching vibration (at 3204cm(-1)). We found the bound water content of the fibers to be 9-14 water molecules per nucleotide pair (i.e. base pair) at variance with the calculated value of calf thymus DNA fiber by Tao's Raman test formula, but in similarity to the determined value by IR spectroscopy, X-ray diffraction, BET gravimetric analysis and differential scanning calorimetry analysis. Thus, herring sperm DNA fibers should have the same hydration state as both calf thymus DNA and salmon sperm DNA, that has been confirmed with the new formula: 2.5926 x I2964/I3204.

Treatment of late recurrent vaginal malignancy after initial radiotherapy for carcinoma of the cervix: an analysis of 73 cases

PURPOSE

To evaluate the reirradiation therapy in late recurrent vaginal malignancy after initial radiotherapy for carcinoma of the cervix.

METHODS

From July 1972 to July 1992, 73 cases of late recurrent (over 5 years) vaginal malignancy after initial radiotherapy for cervical cancer were treated in our hospital. Both the original and recurrent cancers were biopsy-proven squamous cell carcinoma. All of these patients received reirradiation therapy; chemotherapy or operation was combined when necessary. The reirradiation was planned according to the site and volume of the recurrent tumor, previous radiation dose, and radiation side effects. Brachytherapy was mainly used. Before 1981, radium therapy was delivered at 30-40 Gy in 3-5 fractions to tumor base within 3-4 weeks. High-dose-rate (100 cGy/min) cobalt-60 afterloading therapy (Ralstron therapy) has been used instead of radium since 1981; the dose to the tumor base was 20-35 Gy/3-5 fractions/3-4 weeks. Then, vaginal mold was supplemented with a dose to a point 0.5 cm below the surface of the vaginal mucosa at 20-30 Gy/4-6 fractions/2-3 weeks. When the vulva or groin was involved, cobalt-60 or high-energy electron beam radiation was added with a dose at 30-40 Gy. Among these, 61 patients received irradiation therapy alone. Eleven patients received irradiation combined with chemotherapy. One patient received hysterectomy after reirradiation.

RESULTS

The 2-, 3-, and 5-year survival rates in this series were 54.7% (40/73), 46. 6% (28/60), and 40.3% (21/52), respectively. The 5-year survival rates for upper, upper-middle, and upper-lower vaginal tumor were 81. 8% (9/11), 33.3% (5/15), and 25.0% (3/12), respectively. The effect for upper vaginal recurrent malignancy was remarkably better than that for the upper-lower rate (P < 0.05). The local control rates for tumor >4 and <4 cm were 26.6% (4/15) and 86.5% (32/37), respectively (P < 0.01). The side effects of reirradiation in this series were serious: both moderate and severe radiation reactions were rectum 13.6% (10/73), hematuria 12.3% (9/73), vesicovaginal fistula 1.4% (1/73), and rectum-vaginal fistula 11.0% (8/73).

CONCLUSIONS

We conclude that reirradiation for late recurrence in the vagina after previous radiotherapy for cervical cancer is valuable. Early detection and treatment could achieve better results. The smaller the recurrent tumor volume, the better the treatment effects. Reirradiation therapy should be carefully managed in order to reduce the complications as much as possible.

[Laser Raman spectral analysis of superhelical spatial conformation on plasmid DNA]

The pBR322 recombinant plasmids DNA products, which purified by phenol-extract and equilibrium centrifugation in CsCl-ethidium bromide gradients, have been shown as mainly spatial conformation of covalently closed circular DNA (i.e. cccDNA) by agarose gel electrophoresis for homogeneity detection. Laser Raman spectra in the region 450-1750 cm-1 have been obtained for the circular double-stranded plasmids DNA molecule in an aqueous solution, indicating not only contain those marker peaks of secondary structure as in conventional B-form of DNA, but also present both 854 and 1083 cm-1 diagnostic bands of reflecting the vibration state of deoxyribosyl phosphodiester backbone. The present analysis have demonstrated relationship between the superhelical state for cccDNA and the two conformational marker bands that can be considered as the tertiary structure marker on plasmids DNA. Because of markedly Raman hypochromicity of charecter band 1378cm-1 of dT in contrast to liear DNA molecule, as well as the carbonyl double bond vibration line of dT have shifted to higher wave number position, the base stacking analysis represent occurrence of both increase in staking reaction activity of dT, and injury of a number of the Hoogsteen hydrogen bond between dA and dT with exist supercoil structure in cccDNA.

[The development of CTTM-1000 distant electrocardiogram central ambulatory monitoring system]

This article introduces a new electrocardiogam telephone transmitting and central ambulatory monitoring (receiving) system, and a device used for monitoring and transmitting the user's electrocardiogram. We also give some detailed discussion about the real time the flow display of ECG, and the signal preprocessing method based on the design of optimum FIR linear phase digital filter for the detection of QRS complexes.