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The progress from intelligent interactions and supplemented/augmented reality requires artificial skins to shift from the single-functional tactile paradigm. Dual-responsive sensors that can both detect pre-contact proximal events and tactile pressure levels enrich the perception dimensions and deliver additional cognitive information. Previous dual-responsive sensors show very limited utilizations only in proximity perception or approaching switches. Whereas, the approaching inputs from the environment should be able to convey more valuable messages. Herein, a flexible iontronic dual-responsive artificial skin is present. The artificial skin is sensitive to external object's applied pressure as well as its approaching, and can elicit information of target material categories encoded in the proximal inputs. Versatile applications are then demonstrated. Dual-mode human-machine interfaces are developed based on the devices, including a manipulation of virtual game characters, navigation and zooming in of electronic maps, and scrolling through electronic documents. More importantly, the proof-of-concept application of an entirely touchless material classification system is demonstrated. Three types of materials (metals, polymers, and human skins) are classified and predicted accurately. These features of the artificial skin make it highly promising for next-generation smart engineered electronics. Agency for Science, Technology and Research (A*STAR) Nanyang Technological University The authors would like to express their deep appreciation to the funding support of AME YIRG award (A2084c0162) and MTC IRG award (M21K2c0118) from Singapore Agency for Science, Technology and Research (A*STAR), and the NAP award (020482) from Nanyang Technological University.

The genus Paphiopedilum, belonging to the Orchidaceae, has high ornamental value. Leaf variations can considerably improve the economic and horticultural value of the orchids. In the study, a yellow leaf mutant of a Paphiopedilum hybrid named P. SCBG COP15 was identified during the in vitro plant culture process; however, little is known about their molecular mechanisms. For this, RNA-seq libraries were created and used for the transcriptomic profiling of P. SCBG COP15 and the yellow mutant. The Chl a, Chl b, and carotenoid contents in the yellow leaves decreased by approximately 75.99%, 76.92%, and 56.83%, respectively, relative to the green leaves. Decreased chloroplasts per cell and abnormal chloroplast ultrastructure were observed by electron microscopic investigation in yellowing leaves; photosynthetic characteristics and Chl fluorescence parameters were also decreased in the mutant. Altogether, 34,492 unigenes were annotated by BLASTX; 1,835 DEGs were identified, consisting of 697 upregulated and 1138 downregulated DEGs. HEMA, CRD, CAO, and CHLE, involved in Chl biosynthesis, were predicted to be key genes responsible for leaf yellow coloration. Our findings provide an essential genetic resource for understanding the molecular mechanism of leaf color variation and breeding new varieties of Paphiopedilum with increased horticultural value.

Cordia subcordata Lam. (Boraginaceae) is a woody tree that grows in coastal wasteland and mangrove edges. Its wood is used for woodcraft, and the tree, which is used in landscaping, also has medicinal and ecological value (e.g., coastal protection). In this study, a shoot proliferation and regeneration system was established for this plant. Callus was induced from terminal young leaf explants on Murashige and Skoog (MS) medium with 1.0 mg L–1 thidiazuron or 1.0 mg L–1 2,4-dichlorophenoxyacetic acid, or optimally with 0.5 or 1.0 mg L–1 of both. Callus differentiated from an average of 35.4% of explants into 3 to 5 adventitious shoots (indirect shoot organogenesis) within 45 d. Optimal shoot proliferation medium was MS medium with 0.8 mg L–1 6-benzyladenine (BA). A higher concentration of BA (1.5 mg L–1) in the presence of α-naphthaleneacetic acid (NAA) enhanced callus induction from the base of shoots and decreased shoot proliferation. On ½MS medium with 0.5 mg L–1 NAA and/or indole-3-butyric acid, adventitious roots were induced from shoots. Within 1 mo, 95.4% of plantlets transferred to a substrate of vermiculite and peat (1:1, v/v) survived.

Background The orchid genus Pholidota Lindl. ex Hook. is economically important as some species has long been used in traditional medicine. However, the systematic status of the genus and intergeneric relationships inferred from previous molecular studies are unclear due to insufficient sampling and lack of informative sites. So far, only limited genomic information has been available. The taxonomy of Pholidota remains unresolved and somewhat controversial. In this study, the complete chloroplast (cp.) genomes of thirteen Pholidota species were sequenced and analyzed to gain insight into the phylogeny of Pholidota and mutation patterns in their cp. genomes. Results All examined thirteen Pholidota cp. genomes exhibited typical quadripartite circular structures, with the size ranging from 158,786 to 159,781 bp. The annotation contained a total of 135 genes in each cp. genome, i.e., 89 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The codon usage analysis indicated the preference of A/U-ending codons. Repeat sequence analysis identified 444 tandem repeats, 322 palindromic repeats and 189 dispersed repeats. A total of 525 SSRs, 13,834 SNPs and 8,630 InDels were detected. Six mutational hotspots were identified as potential molecular markers. These molecular markers and highly variable regions are expected to facilitate future genetic and genomic studies. Our phylogenetic analyses confirmed the polyphyletic status of the genus Pholidota, with species grouped into four main clades: Pholidota s.s. was resolved as the sister to a clade containing species of Coelogyne; the other two clades clustered together with species of Bulleyia and Panisea, respectively; species P. ventricosa was placed at the basal position, deviated from all other species. Conclusion This is the first study to comprehensively examine the genetic variations and systematically analyze the phylogeny and evolution of Pholidota based on plastid genomic data. These findings contribute to a better understanding of plastid genome evolution of Pholidota and provide new insights into the phylogeny of Pholidota and its closely related genera within the subtribe Coelogyninae. Our research has laid the foundation for future studies on the evolutionary mechanisms and classification of this economically and medicinally important genus.

Enhanced external counterpulsation (EECP) is a non-invasive treatment modality capable of treating a variety of ischemic diseases. Currently, no effective methods of predicting the patient-specific hemodynamic effects of EECP are available. In this study, a personalized 0D-1D model of the cardiovascular system was developed for hemodynamic simulation to simulate the changes in blood flow in the EECP state and develop the best treatment protocol for each individual.A 0D-1D closed-loop model of the cardiovascular system was developed for hemodynamic simulation, consisting of a 1D wave propagation model for arteries, a 0D model for veins and capillaries, and a one-fiber model for the heart. Additionally, a simulation model coupling EECP with a 1D model was established. Physiological data, including the blood flow in different arteries, were clinically collected from 22 volunteers at rest and in the EECP state. Sensitivity analysis and a simulated annealing algorithm were used to build personalized 0D-1D models using the clinical data in the rest state as optimization objectives. Then, the clinical data on EECP were used to verify the applicability and accuracy of the personalized models.The simulation results and clinical data were found to be in agreement for all 22 subjects, with waveform similarity coefficients (r) exceeding 90% for most arteries at rest and 80% for most arteries during EECP.The 0D-1D closed-loop model and the optimized method can facilitate personalized modeling of the cardiovascular system using the data in the rest state and effectively predict the hemodynamic changes in the EECP state, which is significant for the numerical simulation of personalized hemodynamics. The model can also potentially be used to make decisions regarding patient-specific treatment.

Follicular thyroid carcinoma (FTC) is an indolent carcinoma. The cumulative incidence of death from patients with FTC and the nomogram built based on the competing risks model have not been described. The data from patients diagnosed with primary FTC were identified and extracted from the surveillance, epidemiology, and end results (SEER) program (1988–2015). The cumulative incidence function was utilized to calculate the likelihood of death resulting from thyroid cancer and other causes, respectively. Gray’s test was used to examine the difference in the cumulative incidence of death between the groups. A tenfold cross-validation was applied to assess the discrimination and calibration of the model. A total of 9210 patients diagnosed with primary FTC were included. The median follow-up time was 92 months (1–347 months). The 5-year, 10-year, and 20-year probabilities of death from FTC were 2.84%, 5.23%, and 8.61%, respectively. The age at diagnosis, sex, tumor size, pathological subtypes, tumor extension, lymph node involvement, as well as surgical and radiotherapy methods used, were related to the cumulative incidence of death. Multivariate analysis identified several risk factors for patient survival. The model behaved well in terms of performance. A nomogram based on the model allowed the prediction of the probability of death among patients with FTC. The prognosis of FTC is excellent. The likelihood of death caused by thyroid cancer increases with age. Male sex, tumors larger than 4 cm, invasion, extrathyroidal extension, lymph node involvement, and distant metastases increase the risk of dying of thyroid carcinoma. The nomogram constructed on the basis of the model is potentially useful for both clinicians and patients.

Backgrounds: Aglaonema commutatum ‘Red Valentine’, as an excellent foliage ornamental plant, is widely used in interior and exterior decoration because of its easy cultivation and management. However, reducing proportions of red color foliage during large-scale production of A. commutatum seedlings is of frequent occurence, which has considerable implications on the ornamental and market value of the plant, and the molecular mechanisms of this phenomenon remain unclear. Results: To explore the molecular basis leading to the variation in leaf color in A. commutatum ‘Red Valentine’, transcriptome sequencing were performed based on the Illumina platform in two different varieties at three leaf developmental stages. We annotated 63621 unigenes and 14186 differentially expressed genes by pairwise comparison. Further, twenty-six anthocyanin biosynthetic structural genes were identified, the PKM values were significantly higher in ‘Red Valentine’ than those in the green mutant at the three stages examined, which is consistent with the high anthocyanin content of‘Red Valentine’ leaves. Positive transcription factors that may involved in regulating anthocyanin biosynthesis were detected by BLAST tool and correlation analysis and a downregulation of these TFs may downregulate the expression of anthocyanin genes. Full-length cDNA of anthocyanin biosynthesis and regulation genes was obtained and phylogenetic trees were performed to ensure the accuracy of the analysis. Conclusion: Our study provide an insight into the further understanding of leaf variation and facilitate the breeding of ornamental cultivars with high-anthocyanins levels in A. commutatum ‘Red Valentine’.

Rhodomyrtus tomentosa (Ait.) Hask is a multifunctional shrub of the Myrtaceae, which uniquely combines ornamental, medicinal and health purposes. In this study, for the first time, a regeneration system was established in R. tomentosa. At least three types of calli varied in color, shape and texture were induced from explants of leaf, stem, petal or stamen, among which, the light yellow-green, rigidity and granule calli had great potential for differentiation. Adventitious shoots were steady obtained when the calli were grown on 1/2 MS medium with 6-BA 1 mg/L and NAA 0.1 mg/L at 26 °C and 120 µmol m−2s−1 light intensity. Unexpectedly, two types of adventitious roots initiated from the stems above the cutting sites were observed within 15 d when the regenerated plantlets were transferred to PGR-free 1/2 MS medium. When rooted plantlets were transferred to a sandy soil, over 90% survived within 2 months. The established in vitro regeneration system provided a solution for the germplasm preservation and large-scale clonal propagation of elite lines of R. tomentosa.

Euryodendron excelsum H.T. Chang is a first class of rare and endangered woody plant endemic to China. Leaves and petioles from the axillary shoots in vitro were used as explants to culture on the different PGR WPM medium and establish an efficient shoot proliferation and plant regeneration system. Callus and 3–6 adventitious shoots or somatic embryos were induced. WPM supplemented with 1.0 mg/L 2,4-D induced callus that then dedifferentiated into shoots and somatic embryos on different media, including PGR-free WPM. However, only adventitious shoots formed on WPM with 1.0 mg/L of cytokinins, 6-benzyladenine (BA), kinetin (KIN) or thidiazuron (TDZ). When another cytokinin, zeatin, was used, somatic embryos were induced directly from leaves and petioles. Adventitious roots could be induced from both explants on WPM with 1.0 mg/L α-naphthaleneacetic acid (NAA). Somatic embryos cultured in PGR-free WPM or WPM with 0.2 mg/L NAA developed roots. Plantlets derived from somatic embryos were transferred to a peat: sand (1:1, v/v) substrate, with 64.3% survival after 30 d, and 54.6% after 90 d. Callus clumps with adventitious shoot buds that were transferred to WPM with 1.0 mg/L BA and 0.2 mg/L NAA developed mean 3.3 multiple shoots. Callus-derived shoots regenerated and rooted successfully (100%) on agar-free vermiculite-based WPM with 0.5 µM NAA after 30 d. Plantlets transplanted to peat soil: vermiculite (1:1, v/v) displayed highest survival (96.7%) after three months. This protocol allows for the mass propagation of tissue-cultured plants and the conservation of this rare and endangered genetic resource.

Bulbophyllum obtusangulum Z.H. Tsi has long been treated as a synonymy of B. lepidum (Blume) J.J. Sm., which is broadly distributed in Southeast Asia. In this paper, based on a re-evaluation of morphological characters and critical study of herbarium specimens and protologue, B. obtusangulum is proposed as a heterotypic synonym of B. tseanum (S.Y. Hu & Barretto) Z.H. Tsi, which was previously regarded as endemic to Hong Kong.

BACKGROUND AND OBJECTIVES Although the significance of Delphian lymph nodes (DLNs) in patients with papillary thyroid carcinoma (PTC) has been reported, all studies have been based on a small sample size and lack a direct statement concerning prognosis. METHODS A total of 904 consecutive patients were enrolled in the current study, and all patients were divided into two groups (DLN-positive and DLN-negative) according to the presence of DLN metastasis. RESULTS DLN was detected in 687 patients (76.0%), and 123 (17.9%) had DLN metastasis. Compared to those in the DLN-negative group, the proportion of other central lymph node (CLN) metastases, mean number of metastatic CLNs, and mean metastatic CLN ratio were higher in the DLN-positive group (86.2 vs. 50.2%, 6.70 ± 5.19 vs. 1.60 ± 2.37, and 0.54 ± 0.25 vs. 0.18 ± 0.26, respectively; p

In vitro flowering and fruiting of Portulaca pilosa L. were achieved for the first time. The ability of several factors to induce in vitro flowering, including plant growth regulators and carbon sources, were investigated. Initial in vitro flowering (12.1%) from stems, most likely from floral buds that had differentiated before stem sections were inoculated on MS medium supplemented with 30 g/L sucrose, 1.0 µM BA and 0.1 µM NAA, occurred within less than one month. Axillary shoots were subcultured multiple times on this medium. Secondary in vitro flowering (12.2%) and fruit setting from axillary shoots was possible on MS medium supplemented with 120 g/L sucrose without any plant growth regulators. Continuous culture on this medium for 12 days after flowering yielded fruits and produced a mean 58 normal seeds per fruit. Seeds germinated and developed seedlings in vitro without any additional treatment.

Scaevola sericea (Gaertn.) Roxb., which is a semi-mangrove halophyte, displays low seed germination (SG) and poor development. A model system was established to assess seed viability (SV) and enhanced SG in response to 2,3,5-triphenyl-tetrazolium chloride (TTC), and to detect SV under different storage conditions and duration to establish an optional storage method for seeds. Percentage SG (SG%) was also tested with different periods of soaking in water, gibberellic acid (GA3) and seawater after removing fruit pulp. Optimal detection of the percentage of SV (SV%) was possible when seeds were soaked for 3 h in 0.4% TTC. In these conditions, after 15 d, SV% exceeded 90.0%. This indicates that low SG was not related to SV under natural conditions. The nutritious epicarp (pulp) of intact fruit is easily infected by mildew, rotting rapidly in high relative humidity (60–90%). When pulp was removed from fruits, germination period was speeded up by almost 8 d (seeds germinated after sowing for 28 d). This also increased SG%. Seawater broke seed dormancy more efficiently than GA3. The SG% (59.0%) of seeds with their epicarp removed then soaked in seawater for 24 h was higher than seeds soaked in distilled water (24.0%) or in 200 mg/L GA3 (33.7%) after sowing for 40 d The SV% of seeds stored at 4 °C was higher than seeds stored at room temperature (25±3 °C), but when storage period was extended to 180 d or longer, their SV% declined rapidly. In natural conditions, S. taccada seeds have a high SV%. The low SG% is caused by easily rotting pulp and the physiological dormancy of fruits. By removing the pulp and soaking naked seeds in seawater can break seed dormancy and achieve ideal SG which would benefit ecorestoration and landscaping projects.

This study established, for the first time, shoot proliferation and plant regeneration protocols via shoot organogenesis from leaf explants of a medical and ornamental plant, Portulaca pilosa L. The optimal proliferation of axillary shoots was 6.2-fold within 30 days on Murashige and Skoog (MS) medium supplemented with 3.0 µM 6-benzyladenine (BA). Shoots could be induced directly from leaf explants, forming an average of 3.8 adventitious shoots per explant, on optimal MS medium supplemented with 1.0 µM thidiazuron (TDZ) and 0.1 µM α-naphthaleneacetic acid (NAA). A higher concentration of TDZ (3.0 µM), alone or in combination with 0.1 µM NAA, induced somatic embryo-like shoot buds and then developed into real shoots. Rooting was easier since roots were induced on all rooting media within one month. Half-strength MS medium free of plant growth regulators was best for rooting. Rooted plantlets were transferred to a sand: perlite (1:1, v/v) substrate, resulting in highest survival (90%). Plantlets showed more robust growth, however, on substrates of yellow mud: perlite (1:1, v/v) or peat soil: vermiculite: perlite (1:1:1, v/v).

Paphiopedilum orchids have a high ornamental value, and their flower abundance and timing are both key horticultural traits regulated by phytohormones. All one-flowered Paphiopedilum have additional lateral buds in the apical bract that fail to develop. In this study, an exogenous gibberellin (GA3) application promoted flowering of Pathiopedilum callosum by inducing its early bolting instead of the floral transition of dominant flowers. Applying GA3 effectively promoted lateral flower differentiation, resulting in a two-flowered inflorescence. GA-promoted lateral flower formation involved GA interacting with indole-3-acetic acid (IAA) and cytokinins (CTKs), given the decreased CTK content and downregulated expression of CTK synthesis genes, the increased IAA content and downregulated expression of IAA degradation, and the upregulated expression of transport genes. Further, GA acted via PcDELLA, PcTCP15, and PcXTH9 expressed in stage 5 to promote bolting, and via expression of PcAP3, PcPI, and PcSEP to promote flowering. This study provides insight into mechanisms regulating flower development of P. callosum.

Spatial clustering has been widely used for spatial data mining and knowledge discovery. An ideal multivariate spatial clustering should consider both spatial contiguity and aspatial attributes. Existing spatial clustering approaches may face challenges for discovering repeated geographic patterns with spatial contiguity maintained. In this paper, we propose a Spatial Toeplitz Inverse Covariance-Based Clustering (STICC) method that considers both attributes and spatial relationships of geographic objects for multivariate spatial clustering. A subregion is created for each geographic object serving as the basic unit when performing clustering. A Markov random field is then constructed to characterize the attribute dependencies of subregions. Using a spatial consistency strategy, nearby objects are encouraged to belong to the same cluster. To test the performance of the proposed STICC algorithm, we apply it in two use cases. The comparison results with several baseline methods show that the STICC outperforms others significantly in terms of adjusted rand index and macro-F1 score. Join count statistics is also calculated and shows that the spatial contiguity is well preserved by STICC. Such a spatial clustering method may benefit various applications in the fields of geography, remote sensing, transportation, and urban planning, etc.

B7 homolog 4 (B7H4) is considered a negative regulator of immune responses, but the immunoregulatory role of B7H4 in the tumor microenvironment is not clear. Here, we assessed B7H4 expression cell types in human breast cancer tissues and addressed its potential mechanisms in the CD8 T cell immune response. The results from flow cytometry and immunohistochemistry demonstrated that B7H4 was highly expressed in 26 out of 30 (86.7%) breast invasive ductal carcinomas, and B7H4 surface expression on tumor cells was inversely correlated with CD8 T lymphocytes infiltration (p

Triple-negative breast cancer (TNBC) accounts for about 15% of diagnosed breast cancer patients, which has a poor survival outcome owing to a lack of effective therapies. This study aimed to explore the in vitro and in vivo efficiency of histone deacetylase (HDAC) inhibitor panobinostat (PANO) in combination with mTOR inhibitor rapamycin (RAPA) against TNBC. TNBC cells were treated with PANO, RAPA alone or the combination of drugs, then cell growth and apoptosis were evaluated by CCK-8, colony formation and flow cytometry. Cell migration and invasion were detected by wound healing assay and transwell assay, respectively. ROS production was detected by DCFH-DA staining. Western blotting was performed to detect protein levels. In vivo tumor growth was assessed in nude mice. The expression of cleaved caspase-3 and Ki-67 in tumor tissues was detected by immunofluorescence staining. HE staining was conducted to observe the pathological changes in heart, liver, and kidney tissues. The combination of PANO and RAPA exerted a stronger role in repressing growth, migration, invasion, and inducing apoptosis of TNBC cells compared with monotherapy. Furthermore, this combination presented a more effective anti-cancer efficacy than a single treatment in the xenograft model without apparent toxic side effects. Importantly, mechanistic studies indicated that PANO and RAPA combination led to ROS overproduction, which subsequently activated endoplasmic reticulum stress. Conclusion: PANO in combination with RAPA exhibits enhanced efficacy against TNBC, which may be considered a promising therapeutic candidate.

The genus Paphiopedilum, belonging to the Orchidaceae, has high ornamental value. Leaf variations can considerably improve the economic and horticultural value of the orchids. In the study, a yellow leaf mutant of a Paphiopedilum hybrid named P. SCBG COP15 was identified during the in vitro plant culture process; however, little is known about their molecular mechanisms. For this, RNA-seq libraries were created and used for the transcriptomic profiling of P. SCBG COP15 and the yellow mutant. The Chl a, Chl b, and carotenoid contents in the yellow leaves decreased by approximately 75.99%, 76.92%, and 56.83%, respectively, relative to the green leaves. Decreased chloroplasts per cell and abnormal chloroplast ultrastructure were observed by electron microscopic investigation in yellowing leaves; photosynthetic characteristics and Chl fluorescence parameters were also decreased in the mutant. Altogether, 34,492 unigenes were annotated by BLASTX; 1,835 DEGs were identified, consisting of 697 upregulated and 1138 downregulated DEGs. HEMA, CRD, CAO, and CHLE, involved in Chl biosynthesis, were predicted to be key genes responsible for leaf yellow coloration. Our findings provide an essential genetic resource for understanding the molecular mechanism of leaf color variation and breeding new varieties of Paphiopedilum with increased horticultural value.

Background Paphiopedilum, commonly known as slipper orchid, is an important genus of orchid family with prominent horticultural value. Compared with conventional methods such as tillers and in vitro shoots multiplication, induction and regeneration of protocorm-like bodies (PLBs) is an effective micropropagation method in Paphiopedilum. The PLB initiation efficiency varies among species, hybrids and varieties, which leads to only a few Paphiopedilum species can be large-scale propagated through PLBs. So far, little is known about the mechanisms behind the initiation and maintenance of PLB in Paphiopedilum. Results A protocol to induce PLB development from seed-derived protocorms of Paphiopedilum SCBG Huihuang90 (P. SCBG Prince × P. SCBG Miracle) was established. The morphological characterization of four key PLB developmental stages showed that significant polarity and cell size gradients were observed within each PLB. The endogenous hormone level was evaluated. The increase in the levels of indoleacetic acid (IAA) and jasmonic acid (JA) accompanying the PLBs differentiation, suggesting auxin and JA levels were correlated with PLB development. Gibberellic acid (GA) decreased to a very low level, indicated that GA inactivation may be necessary for shoot apical meristem (SAM) development. Comparative transcriptomic profiles of four different developmental stages of P. SCBG Huihuang90 PLBs explore key genes involved in PLB development. The numbers of differentially expressed genes (DEGs) in three pairwise comparisons (A vs B, B vs C, C vs D) were 1455, 349, and 3529, respectively. KEGG enrichment analysis revealed that DEGs were implicated in secondary metabolite metabolism and photosynthesis. DEGs related to hormone metabolism and signaling, somatic embryogenesis, shoot development and photosynthesis were discussed in detail. Conclusion This study is the first report on PLB development in Paphiopedilum using transcriptome sequencing, which provides useful information to understand the mechanisms of PLB development.

The peduncles of Tripsacum laxum Nash were used as explants to induce axillary shoots. Multiple shoots were proliferated on Murashige and Skoog (MS) medium to establish, for the first time, efficient shoot proliferation and plant in vitro regeneration systems. Optimal shoot proliferation medium was MS with 3.0 mg/L 6-benzyladenine (BA) and 0.2 mg/L α-naphthaleneacetic acid (NAA), resulting in a shoot proliferation coefficient of 11.0 within 45 d. Optimal rooting medium was MS with 0.1 mg/L NAA and/or 0.1 mg/L indole-3-butyric acid (IBA), inducing 100% root formation from shoots within 30 d. When young roots, leaf sheaths and shoot bases were used as explants, MS medium with 1.0 mg/L thidiazuron (TDZ) and 0.2 mg/L BA induced most shoots, with the least callus. Shoot bases induced beige-white callus and shoots directly on MS medium with 1.0 mg/L TDZ and 0.2 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), while leaf sheaths induced beige-white callus and shoots directly on MS medium with 1.0 mg/L TDZ and 0.2 mg/L BA. Rooted plantlets showed 99.3% survival when transplanted into a substrate of vermiculite: peat soil (1:3, v/v).

Lepturus repens (G. Forst.) R. Br. is a perennial grass that grows on coral reef outcrops and sandy beaches and has drought tolerance and salt resistance. In this study, the internodes of L. repens were used as explants and cultured on Murashige and Skoog (MS) medium supplemented with 1.13 mg L−1 6-benzyladenine (BA) to successfully induce axillary shoots. Additional experimental results showed that cytokinins were a key factor for the successful induction and proliferation of shoots. BA induced 7.2 axillary shoots per explant, significantly more than kinetin (KIN), which induced 3.5 axillary shoots per explant. Shoots were proliferated more successfully on medium supplemented with 1.13 mg L−1 BA and a low concentration of 0.09 mg L−1 1-naphthaleneacetic acid (NAA) than BA alone. Shoot bases were used as explants for embryogenic callus induction and subsequent plant regeneration, which was possible on MS medium supplemented with 0.11 mg L−1 2,4-D, 0.09 mg L−1 NAA, and 0.22 mg L−1 TDZ. Separately, callus differentiated into adventitious shoot buds on MS medium containing 1.13 mg L−1 BA or 1.10 mg L−1 KIN singly or combined with 0.09 mg L−1 NAA. On MS medium without plant growth regulators (PGR-free) or only containing 0.09 mg L−1 NAA, callus induced both adventitious shoots and somatic embryos that developed a radical on PGR-free medium. All shoots formed roots on ½MS medium containing a low concentration (0.19 to 0.37 mg L−1) of NAA or IBA within 20 d. The survival percentage of plantlets with 3 to 4 shoot clusters exceeded 99% on a substrate consisting of yellow mud, organic fertilizer, and perlite (10:3:1, v:v:v). After transplanting, plantlets with one or two shoot clusters showed 68 to 86% survival within 1 mo.

Paphiopedilum spicerianum (P. spicerianum) is a rare orchid species with high ornamental value. Asymbiotic germination is the most efficient propagation method for conservation and commercial purposes because clonal propagation is very difficult and the separation of native species of Paphiopedilum through aseptic seeding is uncommon owing to their conservatism. However, a high protocorm developmental arresting rate during the asymbiotic germination is the major obstacle for seedling establishment. The fundamental understanding of embryo and protocorm developmental mechanisms will guide the development of an effective propagation method. The morphological and physiological characterization of the key developmental process of embryos and protocorms shows that the mature seeds of P. spicerianum consist of a spherical embryo without an endosperm. Seed coats become heavily lignified once the embryo is mature. Embryo cell size is relatively uniform, and significant structure polarity and cell size gradients occur at the early protocorm stage. The high level of auxin and cytokinin accumulation at the early stage of embryo development and protocorm stage may help to facilitate cell division. The transcriptome profiles of protocorms at three different developmental stages were compared to explore the regulatory mechanism of protocorm development. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that differentially expressed genes were implicated in secondary metabolite metabolism, plant hormone signal transduction and photosynthesis. The temporal expression patterns of candidate genes related to embryo and shoot development were analyzed to reveal their roles in protocorm development: in the early stage of protocorm development, embryonic development related genes such as SERKs and BBM1 were active, while in the late stage of protocorm, shoot apical meristem related genes such as WOX8, CLAVATA2, CUC2, and SCR were active.

Coelogyne fimbriata has been classified as a national second-class protected orchid species in China. In this study, we report and characterize the complete chloroplast (cp) genome sequence of C. fimbriata in an effort to provide genomic resources useful for promoting its conservation and systematic research. The complete genome is 159,010 bp in length and the overall GC content is 43.3%. The cp genome sequence has a typical quadripartite structure, comprising two inverted repeats (IRA and IRB) regions, which are separated by a small single-copy (SSC) region and a large single-copy (LSC) region. Moreover, a total of 135 functional genes were annotated, including 89 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The phylogenetic analysis recovered a close relationship between C. fimbriata and Pleione formosana, and both species are placed within the tribe Arethuseae (Orchidaceae).

To investigate the mechanisms underlying salt tolerance, physiological parameters of six halophyte species [Vitex rotundifolia L., Clerodendrum inerme (L.) Gaertn, Phyla nodiflora (L.) Greene, Scaevola sericea Vahl, Alternanthera bettzickiana (Regel) Nichols, and Dracaena cambodiana Pierre ex Gagn] under NaCl stress in in vitro and in vivo culture tests were examined. Membership function analysis and cluster analysis divided the six species, based on their salt tolerance level, into three groups: Group 1 (highly salt tolerant) included C. inerme, A. bettzickiana and S. sericea; Group 2 (moderately salt tolerant) included P. nodiflora; Group 3 (weakly salt tolerant) included V. rotundifolia and D. cambodiana. In response to in vitro NaCl stress, all six species showed a significant increase in the activities of antioxidant enzymes. NaCl stress enhanced free proline content in the leaves of all six species. CAT, SOD activity and proline accumulation were significantly correlated with the growth of C. inerme, P. nodiflora and A. bettzickiana under in vitro NaCl treatment. We conclude that NaCl-tolerant plants may suffer slight damage within a certain salt concentration, as evidenced by the activities of antioxidant enzymes and the accumulation of free proline. Six halophytic species showed a different salt tolerance level under in vitro and in vivo culture tests, due to the activities of antioxidant enzymes and the accumulation of free proline.

A 4H–SiC detector based on the Schottky diode was fabricated and the combined influence of high temperature and gamma irradiation on 4H–SiC detector has been investigated. We tested the detector's performance at high temperature before gamma irradiation. I–V characteristics and the alpha energy spectra were measured with the 4H–SiC detector before gamma irradiation at high temperature up to 200 °C. The leakage current of the 4H–SiC detector was only 98.7 nA at 200 °C and with a operating voltage of 70 V. The detector showed an energy resolution of 2.36% at 200 °C in detection of 241Am alpha-particles. Then the detector was irradiated by 60Co gamma-ray up to a dose of 1 MGy. I–V characteristics measurements and α energy spectrum measurements were also performed at 200 °C after each irradiation. Both the forward current and the reverse current increased after gamma irradiation. The Schottky barrier height was extracted from the forward I–V curves and it decreased by 0.17 V at a dose of 1 MGy. The response for 241Am source showed that the charge collection efficiency of the detector reduced by only 1.6% and the FWHM can be regarded as unchanged. It has been proved that 4H–SiC detector can work well at 200 °C after exposure to 60Co gamma-ray of 1 MGy.

Metasequoia glyptostroboides Hu et Cheng (dawn redwood), a known relict living fossil, is listed as a Class I rare and endangered tree in China. An efficient in vitro propagation protocol was established in this study to overcome the shortage of germplasm that cannot be compensated by conventional reproduction and as a way to preserve this tree. This objective was achieved by testing the effect of plant growth regulators (PGRs) on shoot propagation and root formation. Axillary shoots, which could be induced on PGR-free woody plant medium (WPM), were efficiently propagated on WPM supplemented with 16.0 µM zeatin and 2.5 µM indole-3-butyric acid. Improved rooting was possible on WPM supplemented with 0.05 µM α-naphthaleneacetic acid. Rooting was possible both in vitro in vermiculite-based PGR-free liquid culture and ex vitro in plastic bags containing perlite: vermiculite (1:1, v/v). This effective in vitro micropropagation protocol for M. glyptostroboides serves as a way to conserve this tree and provides an opportunity for mass production to alleviate strain on natural populations.

We tested a layered structure of 10B4C on 6LiF (10B4C/6 LiF) neutron converter for use with silicon neutron detectors . The combined layers effectively improve the efficiency of thermal-neutron detection over that of traditional single-layer converters. Silicon neutron detectors were constructed from a 2 cm × 2 cm silicon planar detector and coupled with removable neutron converters made from layers of 10B4C, 6LiF, or 10B4C/6LiF deposited on ceramics. The responses of these devices were tested with an 241 Am–Li neutron source and the accompanying background gamma rays . The capability of the devices to discriminate neutron events from background gamma rays was tested by varying the bias voltages of the detectors when irradiated with an 241Am–Li neutron source and with 137Cs or 60 Co gamma sources . The silicon neutron detector using the 10B4C/6LiF converter of 1.2- μ m-thick 10B4C and 21.1- μ m-thick 6 LiF achieved the expected thermal-neutron detection efficiency of 5.6%. The compact size, simple construction, and low bias voltage of these devices make them promising for neutron detector applications like neutron dosimeters and beam monitors.

Irradiation experiments with equivalent neutron fluence and different neutron fluxes were performed to investigate the impact of neutron flux on the radiation damage of silicon based bipolar junction transistors (BJTs). During irradiation the current gain of transistors exposed to higher neutron flux decreased more. However, after annealing of identical time, the current gain of transistors exposed to lower neutron flux displayed greater decrease. These results point out that neutron flux will affect the final damage of BJTs under suitable conditions. Furthermore, a simulation model based on the theory of diffusion-limited reactions was used to analyze the microscopic mechanism. By comparing experimental data with simulative results, a qualitative agreement is obtained and neutron flux effects in BJTs are found to be related to the competition between the formation of stable vacancy associated defects and the recombination of vacancies and interstitials.

Papillary thyroid cancer (PTC) is the main histological type of thyroid cancer and accounts for almost all increased cases worldwide. Patients with PTC exhibit a favorable prognosis, but the fact that PTC is often accompanied by a high prevalence of lymph node metastasis (LNM) means that the overall recurrence-free survival rate in PTC patients is relatively low. Herein, we identified that ID3 expression is subdued in PTC tissues and closely associated with LNM and a poor disease-free survival outcome in PTC patients. The main contributor to this gene repression is the hypermethylation of the CpG island at the promoter of ID3. Besides, we uncovered that a loss of ID3 promotes invasion and migration of PTC cells, while an ectopic overexpression of ID3 inhibits invasion and migration. Mechanistically, ID3 exhibits tumor suppressor functions in PTC cells by interacting with E47 to form heterodimers that prevent E47 binding to CDH1 promoter and maintaining CDH1 transcription and epithelial phenotype in PTC cells. Taken together, our study demonstrates that ID3 plays a tumor suppressor role in PTC and impedes metastasis by inhibiting E47-mediated epithelial to mesenchymal transition.

Different amounts of urushiol were added to a fixed amount of polyacrylonitrile (PAN) to make nanoscale urushiol/PAN films by the electrospinning method. Electrospinning solutions were prepared by using dimethylformamide (DMF) as the solvent. Nanoscale urushiol/PAN films and conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)/polyvinyl pyrrolidone (PVP) films were prepared by electrospinning. In order to prepare an electrospun sandwich nanoscale film, urushiol/PAN films were deposited as both the top and bottom layers and PEDOT:PSS/PVP film as the inner layer. When the PAN to urushiol ratio was 7:5, the fiber diameter ranged between 150 nm and 200 nm. The single-layer urushiol/PAN film could not be etched after being immersed into 60%, 80%, and 100% sulfuric acid (H2SO4) for 30 min, which indicated the improved acid resistance of the PAN film. The urushiol/PAN film was used to fabricate the sandwich nanoscale films. When the sandwich film was immersed into 80% and 100% H2SO4 solutions for 30 min, the structure remained intact, and the conductive PVP film retained its original properties. Thus, the working environment tolerability of the functional PVP film was increased.

Background Oguchi disease is a rare autosomal recessive form of congenital quiescent night blindness. Oguchi disease has been found to be associated with gene mutations in SAG and GRK1, which are vital factors in the recovery phase of phototransduction after light stimuli. We report a case of Oguchi disease with novel heterozygous mutations in SAG. Case presentation A 7-year-old girl with a history of night blindness since childhood, was referred to our hospital. Ophthalmologic examinations included visual acuity, fundus examinations, fundus photography, spectral-domain optical coherence tomography, electroretinographic (ERG). Mutation screening of the SAG and GRK1 genes was performed. This patient exhibited typical clinical characteristics of Oguchi disease, including night blindness, golden fundus with the Mizuo–Nakamura phenomenon, packed structure of the parafovea in optical coherence tomography and reduced a-waves and b-waves in scotopic 3.0 ERG. Genetic testing revealed a heterozygous change in nucleotide c.72_75+15delATCGGTGAGTGGTGCACAA in exon 2 of the SAG gene in this patient, her unaffected mother and younger brother. A splicing alteration of nucleotide c.376-2A>C was identified in exon 6 of the SAG gene with heterozygous status in this patient and her unaffected father. Conclusions Compound heterozygosity of a nonsense p.S25X mutation in exon 2 and a splicing alteration in exon 6 of the SAG gene is the cause of this patient with Oguchi type 1 disease in China.

Paphiopedilum armeniacum is a rare orchid native to China with high ornamental value. The germination of P. armeniacum seeds is difficult, especially for the mature seeds, which is the major limitation for their large-scale reproduction. This study explored the reasons for seed germination inhibition from the aspects of the important plant endogenous hormone&mdash, abscisic acid (ABA). The major endogenous hormone contents of seeds were determined at different developmental stages. The ABA content was 5.8 ng/g in 73 days after pollination (DAP) for the immature seeds, peaked at 14.6 ng/g in 129 DAP seeds, and dropped to 2.6 ng/g in the late mature stage of the 150 DAP seeds. The reduction of ABA content in the mature seed suggests a possible contribution to the increased expression of CYP707A, an ABA catabolism gene. The germination rate of the immature seeds was reduced to 9% from 69% when 5 &mu, g/mL ABA was added to the Hyponex N026 germination medium. The result showed that ABA can inhibit the germination of P. armeniacum immature seeds. However, for the heavily lignified mature seeds, reduction in endogenous ABA level does not result in an increase in the germination rate. Lignin accumulation in the seed coat imposes the physical dormancy for P. armeniacum. In summary, the germination of P. armeniacum is regulated by both ABA and lignin accumulation.

Paphiopedilum armeniacum is a rare orchid native to China with high ornamental value. The germination of P. armeniacum seeds is difficult, especially for the mature seeds, which is the major limitation for their large-scale reproduction. This study explored the reasons for seed germination inhibition from the aspects of the important plant endogenous hormone—abscisic acid (ABA). The major endogenous hormone contents of seeds were determined at different developmental stages. The ABA content was 5.8 ng/g in 73 days after pollination (DAP) for the immature seeds, peaked at 14.6 ng/g in 129 DAP seeds, and dropped to 2.6 ng/g in the late mature stage of the 150 DAP seeds. The reduction of ABA content in the mature seed suggests a possible contribution to the increased expression of CYP707A, an ABA catabolism gene. The germination rate of the immature seeds was reduced to 9% from 69% when 5 μg/mL ABA was added to the Hyponex N026 germination medium. The result showed that ABA can inhibit the germination of P. armeniacum immature seeds. However, for the heavily lignified mature seeds, reduction in endogenous ABA level does not result in an increase in the germination rate. Lignin accumulation in the seed coat imposes the physical dormancy for P. armeniacum. In summary, the germination of P. armeniacum is regulated by both ABA and lignin accumulation.

Euryodendron excelsum H. T. Chang is a single-type, rare and endangered woody plant unique to China. In this study, young stems were used as explants and cultured on Woody Plant Medium (WPM) supplemented with 5.0 μM 6-benzyladenine (BA), were subcultured for more than 15 times over a total of more than 3 years and finally an efficient axillary shoot proliferation and plantlet regeneration system was established in which one shoot could proliferate an average of 5.1 axillary shoots every 2 months on the medium supplemented with 5.0 μM BA and 0.5 μM α-naphthaleneacetic acid (NAA). Shoots rooted at a moderate frequencies (50.1%) on agarized WPM supplemented with 0.5 μM NAA but 100% of shoots rooted in agar-free vermiculite-based WPM after culture for 2 months. Plantlets, when transplanted to peat soil: vermiculite (1:1), showed the highest 95.1% survival within 1 month.

Backgrounds Paphiopedilum is an important genus of the orchid family Orchidaceae and has high horticultural value. The wild populations are under threat of extinction because of overcollection and habitat destruction. Mature seeds of most Paphiopedilum species are difficult to germinate, which severely restricts their germplasm conservation and commercial production. The factors inhibiting germination are largely unknown. Results In this study, large amounts of non-methylated lignin accumulated during seed maturation of Paphiopedilum armeniacum (P. armeniacum), which negatively correlates with the germination rate. The transcriptome profiles of P. armeniacum seed at different development stages were compared to explore the molecular clues for non-methylated lignin synthesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that a large number of genes associated with phenylpropanoid biosynthesis and phenylalanine metabolism during seed maturation were differentially expressed. Several key genes in the lignin biosynthetic pathway displayed different expression patterns during the lignification process. PAL, 4CL, HCT, and CSE upregulation was associated with C and H lignin accumulation. The expression of CCoAOMT, F5H, and COMT were maintained at a low level or down-regulated to inhibit the conversion to the typical G and S lignin. Quantitative real-time RT-PCR analysis confirmed the altered expression levels of these genes in seeds and vegetative tissues. Conclusions This work demonstrated the plasticity of natural lignin polymer assembly in seed and provided a better understanding of the molecular mechanism of seed-specific lignification process.

An efficient regeneration system via shoot organogenesis and somatic embryogenesis from in vitro leaf and root explants was established for Scaevola sericea for the first time. The highest axillary shoot proliferation coefficient (4.8) was obtained on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 6-benzyladenine (BA) and 0.1 mg/L α-naphthaleneacetic acid (NAA) every 45 days. Young in vitro leaves and roots, which were used as explants, were cultured onto medium supplemented with different plant growth regulators. Our results showed that only cytokinins BA and thidiazuron (TDZ), could induce adventitious shoots and somatic embryos from leaf and root explants. The optimal medium to achieve this was MS medium supplemented with 2.5 mg/L BA and which induced most adventitious shoots (2.7) and somatic embryos (17.3) from leaf explants within 30 days. From root explants, 1.1 adventitious shoots and 7.6 somatic embryos could be induced on MS medium supplemented with 2.5 mg/L TDZ. Histological observation showed that both somatic embryos and adventitious shoots were originated from homogeneous parenchyma and the development of somatic embryos was visible. Maximum rooting percentage (99.0%) was achieved on half-strength MS medium supplemented with 2.5 mg/L NAA. Well-rooted plantlets, which were transplanted into a substrate of pure river sand, displayed a high survival percentage of 91.7% after transplanting for 45 days while the best substrate for plantlet growth was river sand: coral sand (1:1).

Paphiopedilum wardii Sumerh. is an endangered and rare terrestrial orchid threatened with extinction in the wild due to anthropogenic activities. Asymbiotic germination provides a useful way for ex situ conservation, for reintroduction in the wild, and for commercial demand. The 180-day seeds after pollination had highest germination rate with 65.33%, and 1/2MS supplemented with 0.5 mg l−1 NAA, 10% coconut water, and 1.0 g l−1 activated charcoal was a suitable medium. Hyponex N026 medium containing 1.0 mg l−1 NAA, 1.0 g l−1 peptone, 10% CW, and 1.0 g l−1 AC was most suitable for subculture of plantlets. Hyponex N016 medium containing 1.0 mg l−1 NAA, 1.0 g l−1 peptone, 100 g l−1 banana homogenate, and 1.0 g l−1 AC was suitable for plantlets’ growth in vitro. The plantlets 5 cm in height were transplanted in mixture media [2: 1: 1 (v/v) Zhijing stone for orchids/sieved peat/shattered fir bark]. Survival rate of 92.33% was obtained after 180 days in a greenhouse. 10,000 plantlets in vitro were obtained. We used the 1000 plantlets propagated in vitro to reintroduce into one habitat and two sites outside the species range. The 180-day transplanted seedlings were reintroduced into habitat at Gaoligong Mountain in Yunnan or alien forest habitats at Yangchun and Guangzhou in Guangdong, which had a higher survival percentage than 90-day or 360-day transplanted seedlings. About 2 years after transplantation, around 30% of plants that survived flowered from seedlings transplanted for 360 days at all three reintroduction locations. At Gaoligong Mountain, Lushui, 32% of flowering plants produced fruits and seeds.

Additional file 1: Figure S1. (A) Correlation indices between different samples. (B) Principal component analysis performed on the 15 samples. A: 65 DAP, B: 87 DAP, C: 108 DAP, D: 122 DAP, E:150 DAP. Figure S2. Functional annotations of the unigenes of P. armeniacum seed transcriptome. (A) NR annotated species distribution map similar to the Paphiopedilum armeniacum transcriptome. Dendrobium catenatum shows the highest similarity. (B) GO function annotation. The most abundant functions are binding and catalytic activity in terms of molecular function and metabolic process and cellular process in terms of biological process. Figure S3. Additional data for qPCR assays. (A) The quality of RNA used for qPCR assessed by agarose gel electrophoresis. 1–4: 66 DAP, 5–8:87 DAP, 9–12: 108 DAP, 13–16: 122 DAP, 17–20: 150 DAP. Lanes 1 and 2 are the 28S and 18S RNA bands. (B) Quantification of RNA used for qPCR estimated by Nanodrop One and Agilent 2100 Bioanalyzer. (C) Melt curve from qPCR of PAL1, PAL2, C4H, 4CL, HCT, CCoAOMT1, CCoAOMT2, F5H, COMT1, and COMT2 genes. The single peak observed presented the pure and single amplicon resulted from the assay. Figure S4. (A) Distribution of differentially expressed transcription factors (TFs); (B) Expression profiles of MYBs potentially related to lignin synthesis.

Tigridiopalma magnifica is a rare and endemic perennial herb plant, the only species in the genus Tigridiopalma in in the Melastomatacea family in Yangchun, Xinyi, and Gaozhou cities of China, where it is categorized as Critically Endangered on the national Red List. Twelve locations with less 10,000 individuals of T. magnifica have been identified (1 extinct, 11 extants). T. magnifica only grows in the surface soil on stone walls or rocks under the canopy of secondary forests and plantations and has no specific associated plant species. An efficient propagation in vitro system using seeds and leaves as explants has been established for T. magnifica C. Chen. About 20,000 well-developed root systems were transferred to planting pots containing a mixture of sand, sieved peat, and perlite (1:1:1; v/v) in greenhouse conditions. More than 80.0% of the plantlets survived after 30 days. We reintroduced 10,000 plantlets produced by tissue culture into three reintroduction locations in and outside the current and historical distribution area of this species. After 11 months survival rate was 40–58%, while the survival was higher and plantlet crowns were larger at the location within the original range of the species than at the other two sites.