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Clay brick masonry unit (CBMU) walls are widely used in building structures, and its damage and protection under explosion loads have been a matter of concern in the field of engineering protection. In this paper, a series of full-scale experiments of the response characteristics of 24 cm CMBU walls unreinforced and reinforced with polyurea elastomer subjected to blast loading were carried out. Through setting 5.0 kg TNT charges at different stand-off distances, the damage characteristics of masonry walls at different scaled distances were obtained. The reinforcement effect of different polyurea coating thicknesses and methods on the blast resistance performance of masonry walls under single and repeated loads were also explored. Five failure grades were summarized according to the dynamic response features of masonry walls. Based on the stress wave propagation pattern in multi-media composite structures, the internal stress distribution of masonry walls were analyzed, and the division basis of the masonry walls’ failure grades was then quantified. Combined with Scanning Electron Microscope(SEM) images, the deformation characteristics of soft and hard segments of polyurea and effects of detonation products on microstructures were revealed respectively, which provides an important reference for the design and application of polyurea in the blast resistance of clay brick masonry walls.

Background Neuroinflammation is one of the most important pathogeneses in secondary brain injury after traumatic brain injury (TBI). Neutrophil extracellular traps (NETs) forming neutrophils were found throughout the brain tissue of TBI patients and elevated plasma NET biomarkers correlated with worse outcomes. However, the biological function and underlying mechanisms of NETs in TBI-induced neural damage are not yet fully understood. Here, we used Cl-amidine, a selective inhibitor of NETs to investigate the role of NETs in neural damage after TBI.Methods Controlled cortical impact model was performed to establish TBI. Cl-amidine, 2′3′-cGAMP (an activator of stimulating Interferon genes (STING)), C-176 (a selective STING inhibitor), and Kira6 (a selectively phosphorylated inositol-requiring enzyme-1 alpha (IRE1α) inhibitor) were administrated to explore the mechanism by which NETs promote neuroinflammation and neuronal apoptosis after TBI. Peptidyl arginine deiminase 4 (PAD4), an essential enzyme for neutrophil extracellular trap formation, is overexpressed with adenoviruses in the cortex of mice 1 d before TBI. The short-term neurobehavior tests, magnetic resonance imaging (MRI), laser speckle contrast imaging (LSCI), Evans blue extravasation assay, Fluoro-Jade C (FJC), TUNEL, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), western blotting, and quantitative-PCR were performed in this study.Results Neutrophils form NETs presenting in the circulation and brain at 3 d after TBI. NETs inhibitor Cl-amidine treatment improved short-term neurological functions, reduced cerebral lesion volume, reduced brain edema, and restored cerebral blood flow (CBF) after TBI. In addition, Cl-amidine exerted neuroprotective effects by attenuating BBB disruption, inhibiting immune cell infiltration, and alleviating neuronal death after TBI. Moreover, Cl-amidine treatment inhibited microglia/macrophage pro-inflammatory polarization and promoted anti-inflammatory polarization at 3 d after TBI. Mechanistically, STING ligand 2’3’-cGAMP abolished the neuroprotection of Cl-amidine via IRE1α/ASK1/JNK signaling pathway after TBI. Importantly, overexpression of PAD4 promotes neuroinflammation and neuronal death via the IRE1α/ASK1/JNK signaling pathway after TBI. However, STING inhibitor C-176 or IRE1α inhibitor Kira6 effectively abolished the neurodestructive effects of PAD4 overexpression after TBI.Conclusion Altogether, we are the first to demonstrate that NETs inhibition with Cl-amidine ameliorated neuroinflammation, neuronal apoptosis, and neurological deficits via STING-dependent IRE1α/ASK1/JNK signaling pathway after TBI. Thus, Cl-amidine treatment may provide a promising therapeutic approach for the early management of TBI.

IntroductionIncreased neutrophil extracellular trap (NET) formation has been reported to be associated with cerebrovascular dysfunction and neurological deficits in traumatic brain injury (TBI). However, the biological function and underlying mechanisms of NETs in TBI-induced neuronal cell death are not yet fully understood.MethodsFirst, brain tissue and peripheral blood samples of TBI patients were collected, and NETs infiltration in TBI patients was detected by immunofluorescence staining and Western blot. Then, a controlled cortical impact device was used to model brain trauma in mice, and Anti-Ly6G, DNase, and CL-amidine were given to reduce the formation of neutrophilic or NETs in TBI mice to evaluate neuronal death and neurological function. Finally, the pathway changes of neuronal pyroptosis induced by NETs after TBI were investigated by administration of peptidylarginine deiminase 4 (a key enzyme of NET formation) adenovirus and inositol-requiring enzyme-1 alpha (IRE1α) inhibitors in TBI mice.ResultsWe detected that both peripheral circulating biomarkers of NETs and local NETs infiltration in the brain tissue were significantly increased and had positive correlations with worse intracranial pressure (ICP) and neurological dysfunction in TBI patients. Furthermore, the depletion of neutrophils effectively reduced the formation of NET in mice subjected to TBI. we found that degradation of NETs or inhibition of NET formation significantly inhibited nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 1 (NLRP1) inflammasome-mediated neuronal pyroptosis after TBI, whereas these inhibitory effects were abolished by cyclic GMP-AMP (cGAMP), an activator of stimulating Interferon genes (STING). Moreover, overexpression of PAD4 in the cortex by adenoviruses could aggravate NLRP1-mediated neuronal pyroptosis and neurological deficits after TBI, whereas these pro-pyroptotic effects were rescued in mice also receiving STING antagonists. Finally, IRE1α activation was significantly upregulated after TBI, and NET formation or STING activation was found to promote this process. Notably, IRE1α inhibitor administration significantly abrogated NETs-induced NLRP1 inflammasome-mediated neuronal pyroptosis in TBI mice.DiscussionOur findings indicated that NETs could contribute to TBI-induced neurological deficits and neuronal death by promoting NLRP1-mediated neuronal pyroptosis. Suppression of the STING/ IRE1α signaling pathway can ameliorate NETs-induced neuronal pyroptotic death after TBI.

Intense neuroinflammatory response with widespread microglia/macrophage activation and leucocyte infiltration occurring during the acute phase of traumatic brain injury (TBI) is an important mediator of secondary neurological injury. Neutrophils, as the most abundant leukocytes in peripheral circulation and the first-line transmigrated immune cells at the contused parenchyma following TBI, are suggested to worsen TBI outcomes and exacerbate TBI-related neuroinflammation, via unclear mechanisms. We hypothesized that neutrophil extracellular trap (NET) formation as a key mechanistic regulator, exacerbate microglia/macrophage-mediated neuroinflammation and acute neurological deficits after TBI. In this study, we observed massive NET formation in contused brain tissue of TBI patients and elevated plasma NET biomarkers correlated with upregulated cGAS-STING pathway. Overexpression of peptidylarginine deiminase 4 (PAD4) induces an increase in the NET formation that is accompanied by upregulation of the cGAS-STING pathway and exacerbation of microglia/macrophages-mediated neuroinflammation and neurological injury. Additionally, degradation of NETs-associated DNA by DNase 1 and inhibition of NET formation by pharmacological inhibition of PAD effectively inhibit cGAS-STING pathway activation and ameliorate microglia/macrophages-mediated neuroinflammatory responses. Collectively, our data highlight that targeting NETs is a promising therapeutic strategy for TBI treatment.

Pathophysiological mechanisms of chronic subdural hematoma (CSDH) involve localized inflammation, angiogenesis, and dysregulated coagulation and fibrinolysis. The scarcity of reproducible and clinically relevant animal models of CSDH hinders further understanding the underlying pathophysiology and improving new treatment strategies. Here, we developed a novel rat model of CSDH using extracellular matrices (Matrigel) and brain microvascular endothelial cell line (bEnd.3 cells). One hundred-microliter of Matrigel-bEnd.3 cell (106 cells per milliliter) mixtures were injected into the virtual subdural space of elderly male Sprague-Dawley rats. This approach for the first time led to a spontaneous and expanding subdural hematoma, encapsulated by internal and external neomembranes, formed as early as 3 d, reached its peak at 7 d, and lasted for more than 14 d, mimicking the progressive hemorrhage observed in patients with CSDH. The external neomembrane and hematoma fluid involved numerous inflammatory cells, fibroblasts, and highly fragile neovessels. Furthermore, a localized pathophysiological process was validated as evidenced by the increased expressions of inflammatory and angiogenic mediators in external neomembrane and hematoma fluid rather than in peripheral blood. Notably, the specific expression profiles of these mediators were closely associated with the dynamic changes in hematoma volume and neurological outcome. In summary, the CSDH model described here replicated the characteristics of human CSDH, and might serve as an ideal translational platform for preclinical studies. Meanwhile, the crucial roles of angiogenesis and inflammation in CSDH formation were reaffirmed.

A major challenge in artificial intelligence based ECG diagnosis lies that it is difficult to obtain sufficient annotated training samples for each rhythm type, especially for rare diseases, which makes many approaches fail to achieve the desired performance with limited ECG records. In this paper, we propose a Meta Siamese Network (MSN) based on metric learning to achieve high accuracy for automatic ECG arrhythmias diagnosis with limited ECG records. First, the ECG signals from three different ECG datasets are preprocessed through resampling, wavelet denoising, R-wave localization, heartbeat segmentation and Z-score normalization. Then, an ECG dataset with limited records is constructed to verify the performance of the proposed model and explore variation of model performance with the sample size. Second, a metric-based meta-learning framework is proposed to address the challenge of few-shot learning for automatic ECG diagnosis of cardiac arrhythmia, and siamese network is employed to achieve arrhythmia diagnosis based on similarity metric. Finally, the N-way K-shot meta-testing strategy is proposed based on the siamese network with double inputs, and the experimental results demonstrate that the proposed strategy can effectively improve the robustness of the proposed model.

A novel QTL, qCIR9.1 , that controls callus induction rate in anther culture was identified on chromosome 9 in rice, and based on RNA-seq data, Os09g0551600 was the most promising candidate gene. Anther culture, a doubled haploid (DH) technique, has become an important technology in many plant-breeding programmes. Although anther culturability is the key factor in this technique, its genetic mechanisms in rice remain poorly understood. In this study, we mapped quantitative trait loci (QTLs) responsible for anther culturability by using 192 recombinant inbred lines (RILs) derived from YZX (Oryza sativa ssp. indica) × 02428 (Oryza sativa ssp. japonica) and a high-density bin map. A total of eight QTLs for anther culturability were detected in three environments. Among these QTLs, a novel major QTL for callus induction rate (CIR) named qCIR9.1 was repeatedly mapped to a ~ 100 kb genomic interval on chromosome 9 and explained 8.39–14.14% of the phenotypic variation. Additionally, RNA sequencing (RNA-seq) was performed for the parents (YZX and 02428), low- (L-Pool) and high-CIR RILs (H-Pool) after 16 and 26 days of culture. By using the RNA of the bulked RILs for background normalization, the number of differentially expressed genes (DEGs) both between the parents and between the bulked RILs after 26 days of culture was drastically reduced to only 78. Among these DEGs, only one gene, Os09g0551600, encoding a high-mobility group (HMG) protein, was located in the candidate region of qCIR9.1. qRT-PCR analysis of Os09g0551600 showed the same results as RNA-seq, and the expression of this gene was decreased in the low-callus-induction parent (YZX) and L-Pool. Our results provide a foundational step for further cloning of qCIR9.1 and will be very useful for improving anther culturability in rice.

Because of their widespread use and potential adverse effects in young developing organism, this study focused on the nephrotoxicity and genotoxicity of chronic low-dose exposure to silver nanoparticles (AgNPs) in 32 14-day-old male Wistar rats, randomly divided into three groups receiving AgNP solution (3 mg/kg body weight) intraperitoneally for one, two, or three weeks and the untreated control group (eight animals per group). When the rats were eight weeks old, blood creatinine and urine microalbumin were tested, followed by haematoxylin and eosin (H&E) staining. Proteinuria was found in the animals treated with AgNP for three weeks, and H&E staining revealed pathological changes in the kidney sections of this group. DNA damage was detected with the alkaline comet assay in the groups treated for two and three weeks. All results indicate that chronic exposure, even at a low dose, may affect animal health. The main culprit might be increased and time-dependent reactive oxygen species (ROS) production. Highly reactive ROS could cause a major structural damage to proteins and DNA, change the expression of ion channel proteins, and trigger inflammation. The findings of our in vivo experiment raise concern about nephrotoxic and genotoxic effects of silver nanoparticles in young organisms and call for further investigation of nanoparticle properties that can be modified to minimise the risks., Zbog široke primjene i rizika od štetnog djelovanja srebrnih nanočestica (AgNP) na mladi organizam u razvoju, u središtu pažnje ovog istraživanja bila je njihova nefrotoksičnost i genotoksičnost u 32 mužjaka Wistar štakora od 14. dana starosti koji su intraperitonealno primali otopinu AgNP-a (3 mg/kg tjelesne težine). Štakori su nasumce raspoređeni u tri izložene skupine (osam po skupini) – prva jedan tjedan, druga dva, a treća tri – i jednu kontrolnu skupinu, koja je primala fiziološku otopinu. Kad su štakori navršili osam tjedana, napravili smo pretrage krvi na kreatinin i mokraće na mikro albumin, a zatim i histološku pretragu s bojenjem hematoksilinom i eozinom (H&E). U životinja koje su tri tjedna bile izložene AgNP-u utvrđena je proteinurija, a H&E bojenjem utvrđene su patološke promjene na presjecima bubrežnog tkiva. Alkalnim komet testom otkriveno je oštećenje DNA u skupinama izloženima dva odnosno tri tjedna. Svi naši rezultati upućuju na to da kronična izloženost AgNP-u, makar i u niskim dozama, može utjecati na zdravlje životinja. Primarni je razlog za to vjerojatno povišena proizvodnja reaktivnih kisikovih spojeva (engl. reactive oxygen species, krat. ROS), koja je rasla s vremenom izloženosti. Visokoreaktivni kisikovi spojevi mogu uzrokovati velika strukturna oštećenja bjelančevina i DNA, izmijeniti ekspresiju ionskih kanala bjelančevina te potaknuti upalu. Rezultati našega in vivo istraživanja pozivaju ne samo na zabrinutost zbog nefrotoksičnih i genotoksičnih učinaka srebrnih nanočestica na mlade organizme nego i na potrebu daljnjeg istraživanja promjenjivih svojstava nanočestica ne bi li se rizik od njihova štetnog djelovanja sveo na najmanju moguću razinu.

Background: The mining of excellent allelic variation and the creation of new crop germplasm are the basis for improving breeding efficiency.Results: In this study, a total of 3872 heavy ion-irradiated M2 generation rice seeds and individual leaves were collected, and 484 mixed samples were obtained at a seed-to-leaf ratio of 8:1. Targeted sequencing technology was used to detect the major grain length genes GS3 and grain length. The allelic variation in the broad major gene GW5 and the phenotype data were measured, and 12 mixed samples containing potential mutations and 15 SNPs were obtained; 96 individual plants in the 12 mixed samples were then subjected to Sanger sequencing, combined with the phenotypic data obtained 13 key mutants and their corresponding SNPs; the protein structure and function analysis of the key mutants was carried out, and 6 allelic variants that led to the change in grain shape were mined, as well as the corresponding mutants, including long-grain mutants GS3-2 and GS3-7, short-grain mutants GS3-3 and GS3-5, wide-grain mutant GW5-1 and narrow-grain mutant GW5-4; sequencing identified new grain length gene allelic variants GS3-G1, GS3-G2 and GS3-G3, which provided new functional gene loci and a material basis for molecular breeding and genotype mutation and phenotype analysis, particularly in the context of mutational associations.Conclusion: Based on the above studies, we propose a method for targeted identification of allelic variation in rice grain type genes by combining targeted sequencing of mixed samples and whole genome sequencing. This method can sequence the target fragments of mixed samples, and the detection cost is low; furthermore, the identification cycle based on present method is short due to screening process is on the mutation offspring and the recombination genetic population is not necessary. The principle of present method is not limited to the grain type phenotype and can also be used for the directional detection and identification of other target traits and allele genes.

The objective of the study was to analyze the risk factors for worsening of the disease progression in patients with chronic subdural hematomas (CSDH) during wait-and-observation treatment regimen and conservative treatment with atorvastatin.A total of 196 patients with CSDH were recruited (98 in the atorvastatin group and 98 in the blank placebo group). Receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff for the hematoma volume by testing surgical and nonsurgical outcomes. Other measures, including univariate and multivariate analyses, were performed to identify the potential significant factors indicative of the outcome of therapeutic efficacy of conservative treatment through the characteristics of the baseline indicators at enrollment.Over a median treatment duration of 2 months, lower total cholesterol, higher hematoma volume, and more midline shift were independent risk factors for worse outcomes of atorvastatin treatment for CSDH, and only a higher hematoma volume was an independent risk factor for spontaneous absorption in the placebo group. ROC analysis of all of the data showed that the optimal threshold of hematoma volume was 68.5 ml (sensitivity 73.5%, specificity 74%) in response to the greatest chance of switching to surgery.Critical independent predictors of atorvastatin monotherapy treatment success included higher total cholesterol, lower hematoma volume, and less midline shift in atorvastatin monotherapy, and higher hematoma volume was the only independent risk factor in close follow-up observation patients without any pharmacotherapy. Initial hematoma volume more than 68.5 ml may help clinicians to determine individual risk assessments and to make optimal treatment decisions.http://www.gov . Identifier NCT02024373.

A planar trigger switch constituting of three electrodes was designed and fabricated using low-temperature cofired ceramic, and characterized under an atmospheric pressure. The results showed that when the operating voltage ranges between 77.2% and 86.8% of its self-breakdown voltage, the inductance of the switch was lower than that of commercial spark gap switch by approximately 60 nH, the current rising time was shortened by nearly 1/2, and the peak current increased by about 30%. The peak current and rising edge were 4000 A and 146 ns at 0.22 μF/2.0 kV, respectively, which was in agreement with simulation values well. Subsequently, the switch was devised to be in situ integrated with an exploding foil initiator together. The electrical characterizations were performed on the chip, obtaining the switch's rapid turn- on time of 29 ns and a large current density of $1.08 \times 10^{8}\,\text{A}\cdot \text{cm}^{-2}$ at 0.22 μF/2.25 kV. Furthermore, photon Doppler velocimetry was exploited to capture the detailed trajectory of a 50-μm-thick flyer with an extracted terminal velocity of 2200 m/s. Finally, boron–potassium nitrate pellets and hexanitrostilbene pellets were used to successfully verify the practicability of the chip in the ignition and detonation of explosives.

Cyanobacterial blooms impose a substantial risk for submerged macrophytes in aquatic environments. This study investigated the cellular and transcriptomic responses of Vallisneria natans to microcystin-LR (MCLR) exposure, as well as abscisic acid (ABA) and strigolactone (SL), which are the major compounds in signaling networks that regulate plant defense. The results revealed that MCLR significantly (p0.05) decreased the photosynthetic pigments and significantly (p0.05) increased the contents of the ABA and SL stress-related phytohormones under MCLR stress. Related genes involved in the photosynthetic pathways were down-regulated, including psbO, psbP, psbQ and psbR. In the SL biosynthetic pathway of roots under MCLR stress, related genes, such as D27 and CCD7, were down-regulated, while the CCD8 and MAX1 genes were up-regulated. In the ABA synthetic pathway, the genes LUT5, ZEP, NCED, ABA2 and AAO3 were up-regulated. Furthermore, a reduction in the content of SL enriched ABA after 3 days under MCLR stress. The potential molecular mechanism of the interactions between SL and ABA were confirmed with the relative up- and down-regulated genes in the pathway, and ABA could play a major role in plant physiology under MCLR stress. This study provides valuable information to understand the stress-related mechanisms of response of submerged macrophytes to cyanobacterial blooms.

The purification of micro-polluted water for drinking water can play an important role in solving water crisis. To investigate the effects of spectral composition on nutrient removal and biofuel feedstock production using duckweed, Landoltia punctata was cultivated in different spectral compositions in micro-polluted water. Results showed that the nitrogen and phosphorus removal efficiency were 99.4% and 93.5% at an recommended red and blue light photon intensity mixture ratio of 2:1. Meanwhile, maximum growth rate of duckweed (11.37 g/m

Previous studies found that atorvastatin and dexamethasone were effective in promoting the absorption of chronic subdural hematoma. In this study, we aimed to investigate the effect of pharmacotherapy in an optimized rat model of chronic subdural hematoma. Rat model of chronic subdural hematoma via a bEnd.3 cell and Matrigel mix was established and dynamic changes in different drug treatment groups were tested. The hematoma gradually increased, peaked on the fifth day (263.8±52.85 μl), and was completely absorbed in two weeks. Notably, Kruppelle-like factor 2 expression was significantly decreased with increasing hematoma volume, and then increased in the repair period. The expression of IL-10 was increased and peaked on 7 days, and then decreased at 14 days. The dynamic trends of IL-6, IL-8, MMP-9, and VEGF were also increased first and then decreased. Both monotherapy and the combined treatment by atorvastatin and dexamethasone could counteract the inflammatory activities, decrease hematoma permeability, and improve hematoma absorption, however, most prominent in combined group. The combined treatment could more effectively increase Kruppelle-like factor 2 and ZO-1 expression, attenuate the expression of NF-κb. Most importantly, the combined treatment enhanced the neural functional prognosis and reduced the mortality of chronic subdural hematoma rats. According to our results, the combined treatment could more effectively attenuate inflammatory. And it could also enhance angiogenic activities which could promote the stability of local function and structure of the hematoma cavity, reduce the hematoma volume and improve the outcomes of rats with chronic subdural hematoma than single treatments in the optimized chronic subdural hematoma model.

Tocilizumab, a humanized anti-IL-6 receptor monoclonal antibody, showed its therapeutic efficacy on neuromyelitis optica spectrum disorder (NMOSD). To assess the immunological effects of this drug on B cells, follicular T helper (Tfh) cells, and peripheral T helper (Tph) cells in patients with NMOSD, peripheral B cell and Tfh cell phenotypes were evaluated in 26 patients with NMOSD before and after tocilizumab treatment by nine-color flow cytometry, as well as the expression of costimulatory and co-inhibitory molecules on B cells. Results showed that the frequency of CD27+IgD− switched memory B cells, CD27-IgD- double-negative B cells, and CD27highCD38high antibody-secreting cells was increased in patients with NMOSD. Tocilizumab treatment led to a significant shift of B cells to naïve B cells from memory B cells after 3 months. Three markers on B cells associated with T-cell activation (i.e., CD86 CD69, and HLA-DR) were downregulated after tocilizumab treatment. The frequencies of total Tfh and Tph cells were decreased, whereas that of follicular regulatory T cells tended to increase. Intrinsic increased PD-L1 and PD-L2 expression was characteristic of B cells in patients with NMOSD. Tocilizumab selectively restored PD-L1 on B-cell subsets. These results provided evidence that tocilizumab enhanced B- and T-cell homoeostasis by regulating B-cell differentiation and inhibiting lymphocyte activation in patients with NMOSD.

Class III peroxidases (CIII Prxs) play critical roles in plant immunity by scavenging reactive oxygen species (ROS). However, the functions of CIII Prxs in rice (Oryza sativa L.) immunity are largely unexplored. Here, we report a Prx precursor, OsPrx30, that is responsive to the bacterial blight Xanthomonas oryzae pv. oryzae (Xoo). OsPrx30 was primarily expressed in rice roots, leaves, and stems, and its protein product was mainly localized at the endoplasmic reticulum. Overexpression of OsPrx30 enhanced the plant's susceptibility to Xoo by maintaining a high level of peroxidase (POD) activity and reducing the content of H2 O2 , whereas depletion of OsPrx30 had the opposite effects. Furthermore, we identified an AT-hook transcription factor, OsATH1, that is specifically bound to the OsPrx30 promoter. As observed in plants overexpressing OsPrx30, depletion of OsATH1 enhanced susceptibility to Xoo. Finally, we demonstrated that depletion of OsATH1 increased histone H3 acetylation at the AT-rich region of the OsPrx30 promoter. Taken together, these results reveal a mechanism underlying the POD-induced natural resistance to bacterial diseases and suggest a model for transcription regulation of Prx genes in rice.

Fires and blasts usually take place simultaneously and threaten the safety of engineering structures. In the present work, field tests were carried out to understand the blast-resisting performance of Q390B mild steel circular tubes after exposure to natural fire. An innovative experimental platform was designed to enable the loading of a blast load within seconds after a fire. By defining and quantifying the deformation characteristics of the circular tubes, four typical failure modes were summarized. In addition, it was found that the occurrence of a fracture influenced the variation of relevant deformation parameters. Results of the metallographic examination of the sag area after the explosion impact revealed that the pearlite distribution in Q390B steel was relatively dispersed and disordered compared with that at high temperature, which might have resulted in relatively greater resistance to the dislocation movement. The scanning electron microscopy (SEM) of the fracture showed that many dimples were distributed on the surface of the fracture, and the dimples were larger and deeper at high temperature. Finally, the engineering calculation formulas for the influences of the temperature and the blast scaled distance on the global deflection of the circular tubes were established.

Seed germination and early seedling growth are important agricultural traits for developing populations of both irrigated and directly seeded rice (DSR). To investigate the genetic mechanisms underlying seed germination and early seedling growth in rice, 275 recombinant inbred lines (RILs) were genotyped in this study via the genotyping-by-sequencing (GBS) approach to construct a high-density linkage bin map based on the parent-independent genotyping method. Quantitative trait loci (QTLs) for 12 traits related to seed germination and early seedling growth were analyzed. Totally, 22 additive loci were detected, after analysis of the interaction between additive QTLs and environments, five stable additive loci were obtained. Among them, loci 4, 5, 12 and 14 exhibited clear pleiotropic effects that were associated with multiple traits. Analysis of the effects of the five additive stable loci showed that a single locus increased the corresponding phenotypic value. Ten of the 275 RILs pyramided the excellent alleles of the five stable genetic loci. Most phenotypic values of the ten RILs were greater than the average values. Four RILs (G260, G342, G371, and G401) with more excellent phenotypic values were subsequently selected; these RILs could serve as donor parents of favorable alleles in the breeding process. Due to the existence of pleiotropy, the use of these genetic loci for pyramid breeding can further increase the efficiency to reach breeding goals. In addition, these five stable loci have an average physical interval of only 170 kb, we also further identified five promising candidate genes by qRT-PCR, which provides us with a basis for future cloning of these genes. Overall, this work will help broaden our understanding of the genetic control of seed germination and early seedling growth, and this study provides both a good theoretical basis and a new genetic resource for the breeding of direct-seeded rice.

Physical mutagens, such as carbon-ion beams (CIBs) and gamma rays (GRs), induce mutations with high frequency at a relatively low dose and are more user-friendly and environment-friendly in mutation breeding. Previous studies showed that CIBs induced large sized deletions and insertions, and chromosomal rearrangements, whereas GRs induce shorter deletions and insertions, and more frequent base substitutions. However, the difference on the genomic level between CIB- and GR-induced mutations remains to be clarified. In the present study, we re-sequence six mutagenized lines derived from CIB irradiation and four mutagenized lines derived from GRs. A total of 283 and 381 variations are induced in these mutants by CIBs and GRs, respectively, including single base substitutions (SBSs), small insertion and deletions (InDels), multiple nucleotide variants (MNVs). SBSs are the most abundant type of mutation and single base transition is the main form for SBSs. CIB-induced InDels accounted for 25.44% of the total variations, while GR-induced InDels accounted for 17.85%. On the contrary, the frequency of MNVs induced by GRs was approximately 2.19 times that induced by CIBs, which indicates CIBs induced increased InDels, whereas GRs induced increased MNVs. Notably, multiple base deletions (≥5 bp) were induced at a much higher frequency by CIBs than by GRs. We also find mutations induced by CIBs and GRs are unevenly distributed on chromosomes. Unusual high-frequency (HF) and low-frequency (LF) mutation regions are discovered by analyzing mutations per 1Mb along the genome. The mutation frequency within the HF regions were significantly higher than the LF regions (P < 0.05). A large majority of SBSs, InDels, and MNVs induced by CIBs and GRs occurred in upstream and downstream regions. Our study compares difference of mutation profiles induced by the CIB irradiation and GR on rice genomes, and give some clues for understanding the mutagenesis mechanism of physical radiation and improving the mutagenesis efficiency.

Background Rice blast caused by Magnaporthe oryzae (M. oryzae) is one of the most destructive diseases in rice production. Development of resistant varieties through pyramiding of resistant (R) genes is considered as an effective strategy to cope with the disease. However, is it really essential to pyramid more R genes in a specific ecological regions? To answer this question, a set of rice improved lines were developed in this study. Afterwards, the blast disease resistance and agronomic traits of the recurrent parent (RP), donor parents (DPs) and improved lines were investigated. Results We developed seven improved lines, comprising three monogenic lines, three two-gene pyramids and one three-gene pyramid, by introgression of R gene(s) into a common genetic background using marker-assisted backcross breeding (MABB). Based on 302 SSR markers, the recurrent genome of the seven improved lines reached a range of 89.1 to 95.5%, with the average genome recovery of 92.9%. The pathogenicity assays inoculated with 32 different blast isolates under artificial conditions showed that the resistance spectrum of all the improved lines was significantly broadened. The assays further showed that the two-gene pyramids and the three-gene pyramid exhibited wider resistance spectrum than the monogenic lines. At natural nurseries, the three monogenic lines still showed high ratios of infected panicles, whereas the two-gene pyramids and the three-gene pyramid showed high level of panicle blast resistance. However, the two-gene pyramid R504 reached the similar resistance effect of the three-gene pyramid R507 considering resistance spectrum under artificial conditions and panicle blast resistance under field conditions. Generally, the improved lines showed comparable agronomic traits compared with the recurrent parent (RP), but the three-gene pyramid showed reduced grain yield per plant. Conclusions All the improved lines conferred wider resistance spectrum compared with the RP. Yet, the three monogenic lines did not work under field conditions of the two nurseries. Given the similar performances on the main agronomic traits as the RP, the two-gene pyramids have achieved the breeding goals of broad resistance spectrum and effective panicle blast resistance. Whereas, the three-gene pyramid harboring Pi2, Pi46 and Pita seems superfluous considering its reduced yield, although it also showed displayed high level of blast resistance. Thus, rational use of R genes rather than stacking more R genes is recommended to control the disease.

Studies have suggested that heightened neuroinflammation contributes to the pathogenesis of depressive disorder. A major participant in neuroinflammation is microglia, and fractalkine signaling (which comprises the chemokine CX3CL1, mainly expressed by neurons, and its receptor CX3CR1, almost exclusively present on microglia in healthy brains) has been reported to critically regulate microglial activity. The aim of this study was to investigate whether CX3CR1 deficiency was associated with a different outcome following chronic unpredictable stress (CUS) and the possible mechanism. Wild-type (WT) and CX3CR1-deficient (CX3CR1-/-) mice were subjected to CUS for 3 weeks. CX3CR1-/- mice displayed a better performance through sucrose preference test, open field test and forced swim test, which demonstrated that CX3CR1 deficiency alleviated depressive-like disturbances, such as anhedonia, anxiety or hopelessness. Nevertheless, CX3CR1-/- mice also showed less severe cognitive impairment from the results of Morris Water Maze and Novel object recognition. Long-term potentiation was recorded to test the synaptic plasticity and its result was consistent with that of cognitive ability tests. Both results of real time-PCR and immunofluorescence staining demonstrated that CX3CR1 deficiency facilitated the alternative activation of microglia, thus attenuated the release of inflammatory cytokines, which was verified by ELISA and flow cytometry. Maybe due to the mitigated neuroinflammation, CX3CR1-deficient mice showed higher resilience to CUS-induced blood brain barrier hyperpermeability and loss of dendrite spine (as showed by Golgi and DiI staining) than WT group. All of above results indicated that hampering neuron-microglia communication via CX3CR1-CX3CL1 pathway attenuated the effects of CUS on depressive-like disturbances and cognitive impairment.

Background Anaerobic germination tolerance is an important trait for direct-seeded rice varieties. Understanding the genetic basis of anaerobic germination is a key for breeding direct-seeded rice varieties. Results In this study, a recombinant inbred line (RIL) population derived from a cross between YZX and 02428 exhibited obvious coleoptile phenotypic differences. Mapping analysis using a high-density bin map indicated that a total of 25 loci were detected across two cropping seasons, including 10 previously detected loci and a total of 13 stable loci. Analysis of the 13 stable loci demonstrated that the more elite alleles that were pyramided in an individual, the higher the values of these traits were in the two cropping seasons. Furthermore, some anaerobic germination-tolerant recombinant inbred lines, namely G9, G10, G16, and G151, were identified. A total of 84 differentially expressed genes were obtained from the 13 stable loci via genome-wide expression analysis of the two parents at three key periods. Among them, Os06g0110200, Os07g0638300, Os07g0638400, Os09g0532900, Os09g0531701 and Os12g0539751 constitute the best candidates associated with anaerobic germination. Conclusions Both the anaerobic germination-tolerant recombinant inbred lines and the loci identified in this study will provide new genetic resources for improving the anaerobic germination tolerance of rice using molecular breeding strategies, as well as will broaden our understanding of the genetic control of germination tolerance under anaerobic conditions. Electronic supplementary material The online version of this article (10.1186/s12864-019-5741-y) contains supplementary material, which is available to authorized users.

Heavy-ion irradiation is a powerful mutagen and is widely used for mutation breeding. In this study, using whole-genome sequencing (WGS) and RNA sequencing (RNA-seq) techniques, we comprehensively characterized these dynamic changes caused by mutations at three time points (48, 96, and 144 h after irradiation) and the expression profiles of rice seeds irradiated with C ions at two doses. Subsequent WGS analysis revealed that more mutations were detected in response to 40 Gy carbon ion beam (CIB) irradiation than 80 Gy of CIB irradiation at the initial stage (48 h post-irradiation). In the mutants generated from both irradiation doses, single-base substitutions (SBSs) were the most frequent type of mutation induced by CIB irradiation. Among the mutations, the predominant ones were C:T and A:G transitions. CIB irradiation also induced many short InDel mutations. RNA-seq analysis at the three time points showed that the number of differentially expressed genes (DEGs) was highest at 48 h post-irradiation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the DEGs showed that the “replication and repair” pathway was enriched specifically 48 h post-irradiation. These results indicate that the DNA damage response (DDR) and the mechanism of DNA repair tend to quickly start within the initial stage (48 h) after irradiation.

The use of host resistance (R) genes is considered the most cost-effective option to control the rice blast disease. The two allelic R genes Pi2 and Pi9 confer very broad-spectrum resistance against blast isolates collected worldwide. However, the two genes have not yet been widely deployed in rice breeding programmes. Availability of specific markers for them would facilitate incorporating the two R genes into new rice lines through marker-assisted selection. Herein, we report the development and utilization of a robust and specific marker for the Pi2 and Pi9. This marker was derived from polymorphisms within the target gene, and achieved simultaneously distinguish Pi2 and Pi9 from other alleles through high-resolution melting of a small amplicon. With the marker, we were able to transfer the Pi2 into an elite restorer line through marker-assisted backcrossing, successfully obtained effective resistance to blast disease, and we were also able to, respectively, incorporate the Pi2 and Pi9 with two other R genes. As the additive effect, blast resistance in these stacking lines harbouring three R genes were significantly improved.

Eight different sizes of semiconductor bridges and three kinds of charges, namely normal-lead styphnate (N-LS), lead azide (LA) and the double stacked charge (N-LS/LA), were selected to study the ignition characteristics of semiconductor bridge igniters under capacitor discharge conditions. The Neyer D-optimal Method was utilized in the experiments to explore the critical ignition voltages of the igniters. The relationships among the ignition voltage, current, resistance, and ignition time as well as other parameters of these igniters were analyzed. The results obtained were as follows: 1) The critical ignition voltage is positively proportional with the bridge area for the igniters possessing identical charge and ignition mechanism. 2) The ignition time and critical ignition voltage are related to the charges. The relationship of ignition time and charge following the short to long ranking is LA, N-LS/LA, and N-LS, but the relationship of critical ignition voltage and charge follows the opposite ranking. 3) The electroexploding ignition mechanism brings about shorter ignition time than electrothermal ignition mechanism for the igniters with identical charge, but the electroexploding ignition mechanism is accompanied by higher critical ignition voltage than the other.

There is a steady demand for high-quality rice varieties though consumers’ preference for high-quality rice varies from regions. The improvement of the quality of rice, especially its eating and cooking quality (ECQ), is an important breeding target as rice is mainly consumed in cooked form. The development and utilization of breeder-friendly and high-throughput marker systems play a pivotal role in marker-assisted breeding of rice cultivars, with pyramids of valuable genes affecting rice ECQ. In this study, we developed functional markers based on the Kompetitive Allele-Specific PCR (KASP) method for three principal genes, Wx, BADH2 and ALK, affecting ECQ in rice. The accuracy of all KASP markers was verified and confirmed with Sanger sequencing. A diverse rice panel consisting of 38 indica cultivars, 9 japonica cultivars and 1 Javanica cultivar were used to assess the validity of these markers for genotyping. The results showed that the functional KASP markers of Wx, ALK and BADH2 could effectively distinguish the different alleles. The genotyping results highly coincided with the phenotypic traits of rice eating and cooking quality. Eight rice entries harboring 3 favorable alleles were identified and superior rice restorers with improved ECQ were bred via functional marker genotyping. Breeders can develop rice cultivars that have desirable ECQ, customized to meet the market requirements in target regions. Hence, the development of these 3 applicable KASP functional markers based on allelic variation would be valuable for improving rice eating and cooking quality through maker-assisted selection to carter various consumer preferences especially in Asian areas.

Additional file 1: Table S1. The 110 polymorphic markers between the RP and the DPs. Table S2. The information of the remaining 14 markers showing the DPsâ genotype at homozygous or heterozygous state. Table S3. The percentage of parental genome recovery of the 28 BC3F4 plants. Table S4. Performances of main agronomic traits of the tested lines during the early crop season (March to July) of 2016. Figure S1. Genetic background analysis of the seven improved lines by the remaining 14 SSR markers which detected polymorphic between the RP and the BC3F1 sample.

Although adenosine monophosphate (AMP) binding domain is widely distributed in multiple plant species, detailed molecular functions of AMP binding proteins (AMPBPs) in plant development and plant-pathogen interaction remain unclear. In the present study, we identified an AMPBP OsAAE3 from a previous analysis of early responsive genes in rice during Magnaporthe oryzae infection. OsAAE3 is a homolog of Arabidopsis AAE3 in rice, which encodes a 4-coumarate-Co-A ligase (4CL) like protein. A phylogenetic analysis showed that OsAAE3 was most likely 4CL-like 10 in an independent group. OsAAE3 was localized to cytoplasm, and it could be expressed in various tissues. Histochemical staining of transgenic plants carrying OsAAE3 promoter-driven GUS (β-glucuronidase) reporter gene suggested that OsAAE3 was expressed in all tissues of rice. Furthermore, OsAAE3-OX plants showed increased susceptibility to M. Oryzae, and this finding was attributable to decreased expression of pathogen-related 1a (PR1) and low level of peroxidase (POD) activity. Moreover, OsAAE3 over-expression resulted in increased content of H2O2, leading to programmed cell-death induced by reactive oxygen species (ROS). In addition, OsAAE3 over-expression repressed the floret development, exhibiting dramatically twisted glume and decreased fertility rate of anther. Meanwhile, the expressions of lignin biosynthesis genes were significantly decreased in OsAAE3-OX plants, thereby leading to reduced lignin content. Taken together, OsAAE3 functioned as a negative regulator in rice blast resistance, floret development, and lignin biosynthesis. Our findings further expanded the knowledge in functions of AMBPs in plant floret development and the regulation of rice-fungus interaction.

The introgression of multiple genes into traditional cultivars using marker-assisted selection (MAS) in order to obtain favorable traits is an effective strategy to achieve improved rice lines. Genotyping of markers is a central component of the evaluation of germplasm and the selection of progeny lines. However, efficient DNA extraction and genotyping of large breeding populations still remain limiting factors in rice molecular breeding programs. This study has developed and validated a cost-effective, rapid (

Telocyte (TC) as a special stromal cell exists in mammary gland and might play an important role in the balance of epithelium-stroma of mammary gland. Considering that different types of breast interstitial cells influence the development and progression of breast cancer, TCs may have its distinct role in this process. We here studied the roles of TCs in the self-assembly of reconstituted breast cancer tissue. We co-cultured primary isolated TCs and other breast stromal cells with breast cancer EMT-6 cells in collagen/Matrigel scaffolds to reconstitute breast cancer tissue in vitro. Using histology methods, we investigated the immunohistochemical characteristics and potential functions of TCs in reconstituted breast cancer tissue. TCs in primary mammary gland stromal cells with long and thin overlapping cytoplasmic processes, expressed c-kit/CD117, CD34 and vimentin in reconstitute breast cancer tissue. The transmission electron microscopy showed that the telocyte-like cells closely communicated with breast cancer cells as well as other stromal cells, and might serve as a bridge that directly linked the adjacent cells through membrane-to-membrane contact. Compared with cancer tissue sheets of EMT-6 alone, PCNA proliferation index analysis and TUNEL assay showed that TCs and other breast stromal cells facilitated the formation of typical nest structure, promoted the proliferation of breast cancer cells, and inhibited their apoptosis. In conclusion, we successfully reconstituted breast cancer tissue in vitro, and it seems to be attractive that TCs had potential functions in self-assembly of EMT-6/stromal cells reconstituted breast cancer tissue.

Optimization of the parameters of PID controller of Automobile Anti-locked Braking System based on Particle swarm algorithm is proposed. The method takes the PID controller parameters of automobile Anti-locked Braking System as optimization variables, the control parameters were be optimized by particle swarm optimization in the parameter space. Then taking the parameters which were not optimized and the optimized parameters as control parameters, the simulation is carried out with substituting the control parameters into the PID simulation model of automobile Anti-locked Braking System, the simulation results show the braking distance significantly reduced , braking time advanced, the braking safety of automotive was Improved. Studies have shown that the optimization algorithm is effective and feasible; it can provide reference for us to develop the brakes of automotive.

Hibiscus tiliaceus, a mangrove associate, is an ideal plant for studying salt tolerance and adaptation since it can inhabit both inland and littoral habitats. In this study, we explored the expression profiles of H. tiliaceus under salt stress using a full-length cDNA microarray. Four hundred eighty-six salt-responsive unigenes were identified in H. tiliaceus; 224 of which had high sequence similarity to Arabidopsis. Many genes identified are known to be salt-stress responsive. Furthermore we examined the physiological performance of H. tiliaceus under salt stress. Physiological analysis displayed decrease in ratio of K+/Na+ and negative influence on photosynthesis of H. tiliaceus. Our study indicated that to survive under high salinine intertidal environments, H. tiliaceus evolved its own mechanisms to re-gain both ionic and osmotic homeostasis through coordinated engagement of genes associated with gene transcription, signaling, and down-stream cell transport and detoxification pathways.

Background and purpose Statins are active in reducing plasma lipids, suppressing inflammation and promoting angiogenesis. Because angiogenesis is critical for the absorbance of subdural hematoma (SDH), we hypothesize that atorvastatin promotes angiogenesis to enhance hematoma absorption. Methods SDH was induced in adult Wistar rats and treated with 3 mg/kg, 8 mg/kg of atorvastatin, or vehicle saline daily for 7 days. The treated rats were examined for the level of CD34 +/CD133 + endothelial progenitor cells (EPCs) in the circulation by flow cytometry, hematoma volumes by magnetic resonance imaging (MRI), and changes in cognitive functions. We also examined angiogenesis in the hematoma wall by transmission electronic microscopy and immunohistochemistry for the expression of vascular endothelial growth factor (VEGF), matrix metalloprotease 9 (MMP 9) and angiopoietin. Results SDH volume was significantly reduced and neurological deficits improved in rats receiving the low dose atorvastatin compared to those receiving either the high dose of atorvastatin or saline. Consistent with these outcome measures, the low dose atorvastatin increased the expression of angiopoient-1 and VEGF and reduced MMP9 expression in the connective tissue of the SDH wall, resulting in an increased vascular density and enhanced vascular maturation. Conclusions The low-dose atorvastatin is effective in reducing SDH and improving neurological deficits in a rat model, primarily by promoting angiogenesis and vascular maturation.

Suppressive subtractive hybridization was used to clone transcripts that showed enhanced expression during salt stress in the leaves of a salt-tolerant mangrove species, Aegiceras corniculatum. cDNAs of freshwater germinated and irrigated seedling were used as driver and cDNAs of 6 h salt-stress seedling were used as tester. By sequencing the whole SSH library, we got 577 ESTs. Among which, 30 had no significant homology to any previously identified genes. Five hundred and twenty-seven of the remaining 547 ESTs represent singletons. Real-time quantitative RT-PCR analysis of four transcripts’ expression pattern showed that all of their transcripts were up-regulated during 24 h after salt shock. Their sequences showed high homology to the delta 1-pyrroline-5-carboxylate synthetase, Na+/H+ antiporter and plasma membrane intrinsic proteins, respectively. Rapid amplification of cDNA ends (RACE) was used for obtaining full-length cDNAs of AcPIP1 and AcPIP2. Characterization and phylogenetic analyses were then carried out according to their sequences.

Dextran-capped silver nanoparticles were synthesized by reducing silver nitrate with NaBH4 in the presence of dextran as capping agent. The characters of silver nanoparticles were investigated using UV-Vis spectrophotometer, nano-grainsize analyzer, X-ray diffraction, and transmission electron microscopy. Results showed that the silver nanoparticles capped with dextran were in uniform shape and narrow size distribution. Moreover, compared with polyvinylpyrrolidone (PVP)-capped silver nanoparticles, the dextran-capped ones possessed better stability. Antibacterial tests of these silver nanoparticles were carried out for Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Results suggested that the dextran-capped silver nanoparticles had high antibacterial activity against both Gram-positive and Gram-negative bacteria. In addition, the cytotoxicity in vitro of the dextran-capped silver nanoparticles was investigated using mouse fibrosarcoma cells (L929). The toxicity was evaluated by the changes of cell morphology and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Results indicated that these silver nanoparticles had slight effect on the survival and proliferation of L-929 cells at their minimal inhibitory concentration (MIC). After modified by dextran, the physiochemical properties of the silver nanoparticles had been improved. We anticipated that these dextran-capped silver nanoparticles could be integrated into systems for biological and pharmaceutical applications.

 Premise of the study : Sonneratia caseolaris , a typical mangrove species, is widely distributed in the Indo-West Pacifi c region. EST – SSR markers were developed for this species to examine its genetic diversity.  Methods and Results : A total of 18 EST – SSR primer pairs were designed based on the transcriptome sequences of S. caseolaris . Thirteen primer pairs showed polymorphism with one to three alleles per locus when assessed in two populations from China and Australia. The observed heterozygosity and expected heterozygosity ranged from 0 to 0.5000, and 0 to 0.5217 in the Hainan population, and from 0 to 0.2500, and 0 to 0.4891 in the Queensland population, respectively. Thirteen of the 18 primer sets identifi ed in S. caseolaris can be successfully applied to its congener S. alba, and a much lower level of polymorphisms was observed in this widespread species.  Conclusions : These polymorphic EST – SSR markers for S. caseolaris are likely to be useful for future genetic diversity studies.

Mangroves are critical and threatened marine resources, yet few transcriptomic and genomic data are available in public databases. The transcriptome of a highly salt tolerant mangrove species, Sonneratia alba, was sequenced using the Illumina Genome Analyzer in this study. Over 15 million 75-bp paired-end reads were assembled into 30,628 unique sequences with an average length of 581 bp. Of them, 2358 SSRs were detected, with di-nucleotide repeats (59.2%) and tri-nucleotide repeats (37.7%) being the most common. Analysis of codon usage bias based on 20,945 coding sequences indicated that genes of S. alba were less biased than those of some microorganisms and Drosophila and that codon usage variation in S. alba was due primarily to compositional mutation bias, while translational selection has a relatively weak effect. Genome-wide gene ontology (GO) assignments showed that S. alba shared a similar GO slim classification with Arabidopsis thaliana. High percentages of sequences assigned to GO slim category 'mitochondrion' and four KEGG pathways, such as carbohydrates and secondary metabolites metabolism, may contribute to salt adaptation of S. alba. In addition, 1266 unique sequences matched to 273 known salt responsive genes (gene families) in other species were screened as candidates for salt tolerance of S. alba, and some of these genes showed fairly high coverage depth. At last, we identified four genes with signals of strong diversifying selection (K(a)/K(s)>1) by comparing the transcriptome sequences of S. alba with 249 known ESTs from its congener S. caseolaris. This study demonstrated a successful application of the Illumina platform to de novo assembly of the transcriptome of a non-model organism. Abundant SSR markers, salt responsive genes and four genes with signature of natural selection obtained from S. alba provide abundant sequence sources for future genetic diversity, salt adaptation and speciation studies.

Hibiscus tiliaceus L. is a mangrove associate that occupies the divergent environments of intertidal wetland (L population) and inland (T population). Thus, it is an ideal plant for the study of ecological adaptation and salt tolerance. In this study we compared responses of the two populations to salinity combining a global transcriptional analysis and physiological analysis. Microarray transcript profiling analysis showed both shared and divergent responses to salinity stress in the two populations. A total of 575 unigenes were identified as being salt-responsive in the two populations. Shared responses were exemplified by the regulated genes functioning in confining ribosomal functions, photosynthesis and cellular metabolism. A set of genes functioning in cellular transporting and cell detoxification and a crucial transcription factor AP2 domain-containing protein involved in environmental responsiveness, were differently expressed in the two populations. Physiological analysis showed that the L population was less susceptible to salt stress in photosynthesis and had a stronger capability of K+ : Na+ regulation than the T population. Both microarray and physiological data showed the L population possess higher fitness under high salinity, probably due to it its long-term adaptation to their native environment.

Hibiscus tiliaceus, one of the mangrove associates, is an ideal plant for the study of ecological adaptation and salt tolerance as it may give clues to the evolutionary pathway by which the highly specialized adaptive syndrome of mangrove has been achieved. This species has extremely high contents of polysaccharides, secondary metabolites and especially polyphenolics in its various tissues, such as leaves and roots. So it is extremely difficult for RNA extraction from its various tissues, which prevents following molecular operations and expression-level studies like microarray and RT-PCR. Traditional methods based on CTAB can produce high-quality RNA from specific species or tissue, but they don't work well in H. tiliaceus. We describe here a modified CTAB-based method using PVP and PVPP with sequential extraction of chlorophorm and acid phenol and then selective salt precipitation, which can constantly isolate high-quality RNA from various tissues of H. tiliaceus within short time. RNA quality was assessed through reverse transcription and RT-PCR experiments, indicating that it could be suitable for a number of downstream purposes. We have already constructed a full-length cDNA library with total RNA isolated through the modified method and successfully used it in the following microarray experiments, which is aimed to unravel ecological adaptation and salt tolerance of H. tiliaceus. Moreover, we showed that this method could also be successfully applied to other plants in Malvaceae sensu lato (including Sida, Pachira, Sterculia, Urena, and Abelmoschus) with very abundant polyphenols and polysaccharides.