Overexpression of OsNAR2.1 by OsNAR2.1 promoter increases drought resistance by increasing the expression of OsPLDα1 in rice.

BACKGROUND: pOsNAR2.1:OsNAR2.1 expression could significantly increase nitrogen uptake efficiency and grain yield of rice. RESULT: This study reported the effects of overexpression of OsNAR2.1 by OsNAR2.1 promoter on physiological and agronomic traits associated with drought tolerance. In comparison to the wild-type (WT), the pOsNAR2.1:OsNAR2.1 transgenic lines exhibited a significant improvement in survival rate when subjected to drought stress and then irrigation. Under limited water supply conditions, compared with WT, the photosynthesis and water use efficiency (WUE) of transgenic lines were increased by 39.2% and 28.8%, respectively. Finally, the transgenic lines had 25.5% and 66.4% higher grain yield than the WT under full watering and limited water supply conditions, respectively. Compared with the WT, the agronomic nitrogen use efficiency (NUE) of transgenic lines increased by 25.5% and 66.4% under full watering and limited water supply conditions, and the N recovery efficiency of transgenic lines increased by 29.3% and 50.2%, respectively. The interaction between OsNAR2.1 protein and OsPLDα1 protein was verified by yeast hybrids. After drought treatment, PLDα activity on the plasma membrane of the transgenic line increased 85.0% compared with WT. CONCLUSION: These results indicated that pOsNAR2.1:OsNAR2.1 expression could improve the drought resistance of rice by increasing nitrogen uptake and regulating the expression of OsPLDα1.

WHITE AND LESION-MIMIC LEAF1, encoding a lumazine synthase, affects reactive oxygen species balance and chloroplast development in rice.

The riboflavin derivatives flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are essential cofactors for enzymes in multiple cellular processes. Characterizing mutants with impaired riboflavin metabolism can help clarify the role of riboflavin in plant development. Here, we characterized a rice (Oryza sativa) white and lesion-mimic (wll1) mutant, which displays a lesion-mimic phenotype with white leaves, chlorophyll loss, chloroplast defects, excess reactive oxygen species (ROS) accumulation, decreased photosystem protein levels, changes in expression of chloroplast development and photosynthesis genes, and cell death. Map-based cloning and complementation test revealed that WLL1 encodes lumazine synthase, which participates in riboflavin biosynthesis. Indeed, the wll1 mutant showed riboflavin deficiency, and application of FAD rescued the wll1 phenotype. In addition, transcriptome analysis showed that cytokinin metabolism was significantly affected in wll1 mutant, which had increased cytokinin and δ-aminolevulinic acid contents. Furthermore, WLL1 and riboflavin synthase (RS) formed a complex, and the rs mutant had a similar phenotype to the wll1 mutant. Taken together, our findings revealed that WLL1 and RS play pivotal roles in riboflavin biosynthesis, which is necessary for ROS balance and chloroplast development in rice.

Rice Lesion Mimic Gene Cloning and Association Analysis for Disease Resistance.

Lesion mimic mutants refer to a class of mutants that naturally form necrotic lesions similar to allergic reactions on leaves in the absence of significant stress or damage and without being harmed by pathogens. Mutations in most lesion mimic genes, such as OsACL-A2 and OsSCYL2, can enhance mutants' resistance to pathogens. Lesion mimic mutants are ideal materials for studying programmed cell death (PCD) and plant defense mechanisms. Studying the genes responsible for the rice disease-like phenotype is of great significance for understanding the disease resistance mechanism of rice. In this paper, the nomenclature, occurrence mechanism, genetic characteristics, regulatory pathways, and the research progress on the cloning and disease resistance of rice lesion mimic mutant genes were reviewed, in order to further analyze the various lesion mimic mutants of rice. The mechanism lays a theoretical foundation and provides a reference for rice breeding.

Grain Size Associated Genes and the Molecular Regulatory Mechanism in Rice.

Grain size is a quantitative trait that is controlled by multiple genes. It is not only a yield trait, but also an important appearance quality of rice. In addition, grain size is easy to be selected in evolution, which is also a significant trait for studying rice evolution. In recent years, many quantitative trait loci (QTL)/genes for rice grain size were isolated by map-based cloning or genome-wide association studies, which revealed the genetic and molecular mechanism of grain size regulation in part. Here, we summarized the QTL/genes cloned for grain size and the regulation mechanism with a view to provide the theoretical basis for improving rice yield and breeding superior varieties.

Intramedullary metastasis in medulloblastoma: a case report and literature review.

BACKGROUND: Cerebellar medulloblastomas are the most common malignant tumors of the posterior fossa in childhood that frequently metastasize. Leptomeningeal dissemination and distant metastasis have been associated with medulloblastomas; however, intramedullary metastases are rare with very few case reports in the literature available. METHODS: We present a case of a 3-year-old girl with a medulloblastoma who underwent surgical resection of spinal intramedullary metastases. Histopathology revealed the tumor to be an anaplastic medulloblastoma similar to the intracranial lesions. The patient subsequently underwent postoperative chemotherapy followed by radiotherapy. RESULTS: Following the surgery and subsequent follow-up, the patient showed a good recovery without any new neurological dysfunction. CONCLUSIONS: Intramedullary metastasis of medulloblastoma remains a rare disease. Surgical resection could play a possible role in the management in addition to radiation and chemotherapy.

Gene Mapping, Cloning and Association Analysis for Salt Tolerance in Rice.

Soil salinization caused by the accumulation of sodium can decrease rice yield and quality. Identification of rice salt tolerance genes and their molecular mechanisms could help breeders genetically improve salt tolerance. We studied QTL mapping of populations for rice salt tolerance, period and method of salt tolerance identification, salt tolerance evaluation parameters, identification of salt tolerance QTLs, and fine-mapping and map cloning of salt tolerance QTLs. We discuss our findings as they relate to other genetic studies of salt tolerance association.

Rice EARLY SENESCENCE 2, encoding an inositol polyphosphate kinase, is involved in leaf senescence.

BACKGROUND: Early leaf senescence influences yield and yield quality by affecting plant growth and development. A series of leaf senescence-associated molecular mechanisms have been reported in rice. However, the complex genetic regulatory networks that control leaf senescence need to be elucidated. RESULTS: In this study, an early senescence 2 (es2) mutant was obtained from ethyl methanesulfonate mutagenesis (EMS)-induced mutational library for the Japonica rice cultivar Wuyugeng 7 (WYG7). Leaves of es2 showed early senescence at the seedling stage and became severe at the tillering stage. The contents of reactive oxygen species (ROS) significantly increased, while chlorophyll content, photosynthetic rate, catalase (CAT) activity significantly decreased in the es2 mutant. Moreover, genes which related to senescence, ROS and chlorophyll degradation were up-regulated, while those associated with photosynthesis and chlorophyll synthesis were down-regulated in es2 mutant compared to WYG7. The ES2 gene, which encodes an inositol polyphosphate kinase (OsIPK2), was fine mapped to a 116.73-kb region on chromosome 2. DNA sequencing of ES2 in the mutant revealed a missense mutation, ES2 was localized to nucleus and plasma membrane of cells, and expressed in various tissues of rice. Complementation test and overexpression experiment confirmed that ES2 completely restored the normal phenotype, with chlorophyll contents and photosynthetic rate increased comparable with the wild type. These results reveal the new role of OsIPK2 in regulating leaf senescence in rice and therefore will provide additional genetic evidence on the molecular mechanisms controlling early leaf senescence. CONCLUSIONS: The ES2 gene, encoding an inositol polyphosphate kinase localized in the nucleus and plasma membrane of cells, is essential for leaf senescence in rice. Further study of ES2 will facilitate the dissection of the genetic mechanisms underlying early leaf senescence and plant growth.

Development of nutritious rice with high zinc/selenium and low cadmium in grains through QTL pyramiding.

Enriching zinc (Zn) and selenium (Se) levels, while reducing cadmium (Cd) concentration in rice grains is of great benefit for human diet and health. Large natural variations in grain Zn, Se, and Cd concentrations in different rice accessions enable Zn/Se-biofortification and Cd-minimization through molecular breeding. Here, we report the development of new elite varieties by pyramiding major quantitative trait loci (QTLs) that significantly contribute to high Zn/Se and low Cd accumulation in grains. A chromosome segment substitution line CSSLGCC7 with the PA64s-derived GCC7 allele in the 93-11 background, exhibited steadily higher Mn and lower Cd concentrations in grains than those of 93-11. This elite chromosome segment substitution line (CSSL) was used as the core breeding material to cross with CSSLs harboring other major QTLs for essential mineral elements, especially CSSLGZC6 for grain Zn concentration and CSSLGSC5 for grain Se concentration. The CSSLGCC7+GZC6 and CSSLGCC7+GSC5 exhibited lower Cd concentration with higher Zn and Se concentrations in grains, respectively. Our study thus provides elite materials for rice breeding targeting high Zn/Se and low Cd concentrations in grains.

OsACL-A2 negatively regulates cell death and disease resistance in rice.

ATP-citrate lyases (ACL) play critical roles in tumour cell propagation, foetal development and growth, and histone acetylation in human and animals. Here, we report a novel function of ACL in cell death-mediated pathogen defence responses in rice. Using ethyl methanesulphonate (EMS) mutagenesis and map-based cloning, we identified an Oryza sativa ACL-A2 mutant allele, termed spotted leaf 30-1 (spl30-1), in which an A-to-T transversion converts an Asn at position 343 to a Tyr (N343Y), causing a recessive mutation that led to a lesion mimic phenotype. Compared to wild-type plants, spl30-1 significantly reduces ACL enzymatic activity, accumulates high reactive oxygen species and increases degradation rate of nuclear deoxyribonucleic acids. CRISPR/Cas9-mediated insertion/deletion mutation analysis and complementation assay confirmed that the phenotype of spl30-1 resulted from the defective function of OsACL-A2 protein. We further biochemically identified that the N343Y mutation caused a significant degradation of SPL30N343Y in a ubiquitin-26S proteasome system (UPS)-dependent manner without alteration in transcripts of OsACL-A2 in spl30-1. Transcriptome analysis identified a number of up-regulated genes associated with pathogen defence responses in recessive mutants of OsACL-A2, implying its role in innate immunity. Suppressor mutant screen suggested that OsSL, which encodes a P450 monooxygenase protein, acted as a downstream key regulator in spl30-1-mediated pathogen defence responses. Taken together, our study discovered a novel role of OsACL-A2 in negatively regulating innate immune responses in rice.

Classification between digs and dust particles on optical surfaces with acquisition and analysis of polarization characteristics.

In the automatic detection for surface defects of optical components, the digs and dust particles exhibit similar features: point-like shape and variable intensity reflectivity. On this condition, these two types with entirely different damages are easily confused so that misjudgments will be induced. To solve this problem, a polarization-characteristics-based classification method of digs and dust particles (PCCDD) is proposed based on the polarimetric imaging technique and dark-field imaging technique. First, a dark-field imaging system equipped with a polarization state generator (PSG) and a polarization state analyzer (PSA) is employed to measure and establish normalized Mueller matrices' datasets of digs and dust particles. And by a nonlinear global search combined with a separability evaluation method, the optimal number of acquisitions and corresponding polarization measurement states of the PSG and the PSA are obtained, as well as the parameters of classification function. Then, multiple polarization images are acquired under the optimal states to extract a multidimensional feature description that relates only to the polarization characteristics of the defect; this subsequently acts as the input vector of the classifier to finally achieve the classification. This method takes full advantage of both the difference in polarization properties between digs and dust particles and the characteristic that the polarization properties of digs are relatively invariant while those of dust particles have a large variability. The classification process involves only simple matrix operations. Compared to the traditional discrimination method based on intensity images, the features obtained by this method have a higher separability. Experiments show that the classification accuracy reaches over 90%. This method can be further applied to the recognition and discrimination of other defects in the field of surface defects' detection.

First clinical results of minimally invasive vector lumbar interbody fusion (MIS-VLIF) in spondylodiscitis and concomitant osteoporosis: a technical note.

PURPOSE: First description of MIS-VLIF, a minimally invasive lumbar stabilization, to evaluate its safety and feasibility in patients suffering from weak bony conditions (lumbar spondylodiscitis and/or osteoporosis). METHODS: After informed consent, 12 patients suffering from lumbar spondylodiscitis underwent single level MIS-VLIF. Eight of them had a manifest osteoporosis, either. Pre- and postoperative clinical status was documented using numeric rating scale (NRS) for leg and back pain. In all cases, the optimal height for the cage was preoperatively determined using software-based range of motion and sagittal balance analysis. CT scans were obtained to evaluate correct placement of the construct and to verify fusion after 6 months. RESULTS: Since 2013, 12 patients with lumbar pyogenic spondylodiscitis underwent MIS-VLIF. Mean surgery time was 169 ± 28 min and average blood loss was less than 400 ml. Postoperative CT scans showed correct placement of the implants. Eleven patients showed considerable postoperative improvement in clinical scores. In one patient, we observed screw loosening. After documented bony fusion in the CT scan, the fixation system was removed in two cases to achieve lower material load. CONCLUSIONS: The load-bearing trajectories (vectors) of MIS-VLIF are different from those of conventional coaxial pedicle screw implantation. The dorsally converging construct combines the heads of the dorsoventral pedicle screws with laminar pedicle screws following cortical bone structures within a small approach. In case of lumbar spondylodiscitis and/or osteoporosis, MIS-VLIF relies on cortical bony structures for all screw vectors and the construct does not depend on conventional coaxial pedicle screws in the presence of inflamed, weak, cancellous or osteoporotic bone. MIS-VLIF allows full 360° lumbar fusion including cage implantation via a small, unilateral dorsal midline approach.

Genetic analysis for rice seedling vigor and fine mapping of a major QTL qSSL1b for seedling shoot length.

Seedling vigor is an important agricultural trait as direct-seeded rice technology becomes widely applied. In order to investigate the genetic mechanisms underlying seedling vigor in rice, seeds of 132 recombinant inbred lines (RILs) derived from 93-11 and PA64s, harvested from Lingshui and Hangzhou were cultivated in the nutrient solution, and four indices for seedling vigor were measured including seedling shoot length (SSL), seedling root length (SRL), seedling wet weight (SWW) and seedling dry weight (SDW). Significant correlations were observed among the indices, and also between 1000-seed weight (TSW) and SWW or SDW. Combined with a high-resolution genetic map generated from sequencing of the RILs, 65 quantitative trait loci (QTLs) were detected on all chromosomes with interval of 1.93 Mb on average. Among 57 QTLs for seedling vigor, 28 were detected from seeds harvested in both sites and 33 were first identified. With BC3F2 derived from 93-11 and a CSSL harboring segments from PA64s in 93-11 background, a major QTL for SSL, qSSL1b was fine mapped within 80.5 kb between two InDel markers. Our study provides a platform for further cloning of the QTL and dissecting the molecular basis for seedling vigor at early seedling stage in rice.

Transcriptome analysis of differentially expressed genes in rice seedling leaves under different nitrate treatments on resistance to bacterial leaf blight.

Nitrogen (N), as one of the most abundant mineral elements in rice, not only is the primary limiting factor for rice yield, but also impacts plant disease resistance by modulating plant morphology, regulating biochemical characteristics, as well as enhancing metabolic processes. Bacterial blight, a severe bacterial disease caused by Xanthomonas oryzae pv. oryzae (Xoo), significantly impairing rice yield and quality. Previous studies have shown that moderate application of nitrate nitrogen can improve plant disease resistance. However, further exploration is urgently required to investigate the involvement of the nitrate nitrogen signaling pathway in conferring resistance against bacterial leaf blight. In this study, we employed transcriptome sequencing to analyze the differentially expressed genes under various concentrations of nitrate supply duringrice bacterial blight infection. Our research reveals that nitrate nitrogen supply influences rice resistance to bacterial leaf blight. Through transcriptomic profiling of rice leaves inoculated under different nitrate nitrogen concentrations, we identified 4815 differentially expressed genes (DEGs) among four comparison groups, with notable differences in DEG enrichment between low and high nitrate nitrogen conditions, with some members of the NPF family implicated and we preliminarily elucidated the molecular regulatory network in which nitrate nitrogen participates in bacterial leaf blight resistance. Our findings provide a novel insight into a mechanism involving the nitrate nitrogen drive wider defense in rice.

OsGSTU17, a Tau Class Glutathione S-Transferase Gene, Positively Regulates Drought Stress Tolerance in Oryza sativa.

As a great threat to the normal growth of rice, drought not only restricts the growth of rice, but also affects its yield. Glutathione S-transferases (GSTs) have antioxidant and detoxification functions. In rice, GSTs can not only effectively cope with biological stress, but also play a defense role against abiotic stress. In this study, we selected OsGSTU17, a member gene that was induced by drought, to explore the role of GSTs and analyze their physiological mechanisms that are involved in rice drought tolerance. With the CRISPR/Cas9 knockout system techniques, we obtained two independent mutant lines of osgstu17. After 14 days of drought stress treatment, and then re-supply of the water for 10 days, the survival rate of the osgstu17 mutant lines was significantly reduced compared to the wild-type (WT). Similarly, with the 10% (w/v) PEG6000 hydroponics experiment at the seedling stage, we also found that compared with the WT, the shoot and root biomass of osgstu17 mutant lines decreased significantly. In addition, both the content of the MDA and H2O2, which are toxic to plants, increased in the osgtu17 mutant lines. On the other hand, chlorophyll and proline decreased by about 20%. The activity of catalase and superoxide dismutase, which react with peroxides, also decreased by about 20%. Under drought conditions, compared with the WT, the expressions of the drought stress-related genes OsNAC10, OsDREB2A, OsAP37, OsP5CS1, OsRAB16C, OsPOX1, OsCATA, and OsCATB in the osgtu17 mutant lines were significantly decreased. Finally, we concluded that knocking out OsGSTU17 significantly reduced the drought tolerance of rice; OsGSTU17 could be used as a candidate gene for rice drought-tolerant cultivation. However, the molecular mechanism of OsGSTU17 involved in rice drought resistance needs to be further studied.

TL-MSE2-Net: Transfer learning based nested model for cerebrovascular segmentation with aneurysms.

Cerebrovascular (i.e., cerebral vessel) segmentation is essential for diagnosing and treating brain diseases. Convolutional neural network models, such as U-Net, are commonly used for this purpose. Unfortunately, such models may not be entirely satisfactory in dealing with cerebrovascular segmentation with tumors due to the following issues: (1) Relatively small number of clinical datasets from patients obtained through different modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), leading to inadequate training and lack of transferability in the modeling; (2) Insufficient feature extraction caused by less attention to both convolution sizes and cerebral vessel edges. Inspired by the existence of similar features on cerebral vessels between normal subjects and patients, we propose a transfer learning strategy based on a pre-trained nested model called TL-MSE2-Net. This model uses one of the publicly available datasets for cerebrovascular segmentation with aneurysms. To address issue (1), our transfer learning strategy leverages a pre-trained model that uses a large number of datasets from normal subjects, providing a potential solution to the lack of sufficient clinical datasets. To tackle issue (2), we structure the pre-trained model based on 3D U-Net, comprising three blocks: ResMul, DeRes, and REAM. The ResMul and DeRes blocks enhance feature extraction by utilizing multiple convolution sizes to capture multiscale features, and the REAM block increases the weight of the voxels on the edges of the given 3D volume. We evaluated the proposed model on one small private clinical dataset and two publicly available datasets. The experimental results demonstrated that our MSE2-Net framework achieved an average Dice score of 70.81 % and 89.08 % on the two publicly available datasets, outperforming other state-of-the-art methods. Ablation studies were also conducted to validate the effectiveness of each block. The proposed TL-MSE2-Net yielded better results than MSE2-Net on a small private clinical dataset, with increases of 5.52 %, 3.37 %, 6.71 %, and 0.85 % for the Dice score, sensitivity, Jaccard index, and precision, respectively.

Real-time monitoring of the solution concentration variation during the crystallization process of protein-lysozyme by using digital holographic interferometry.

We report a real-time measurement method of the solution concentration variation during the growth of protein-lysozyme crystals based on digital holographic interferometry. A series of holograms containing the information of the solution concentration variation in the whole crystallization process is recorded by CCD. Based on the principle of double-exposure holographic interferometry and the relationship between the phase difference of the reconstructed object wave and the solution concentration, the solution concentration variation with time for arbitrary point in the solution can be obtained, and then the two-dimensional concentration distribution of the solution during crystallization process can also be figured out under the precondition which the refractive index is constant through the light propagation direction. The experimental results turns out that it is feasible to in situ, full-field and real-time monitor the crystal growth process by using this method.

Digital holographic interferometry based on wavelength and angular multiplexing for measuring the ternary diffusion.

We present a novel method for dynamical measurement of the ternary diffusion by using digital holographic interferometry based on wavelength and angular multiplexing techniques. Two laser beams with different wavelengths (λ1=532 nm and λ2=473 nm) are used for the ternary diffusion measurement, and they are adjusted to make corresponding interference fringes in orthogonal directions on the CCD target. The orthogonal splitting of the fringes enables the spatial frequencies of each wavelength to be filtered separately in the Fourier spectrum of the hologram. Finally, they are reconstructed to obtain the molar concentration. This method is also suitable for two-phase diffusion measurement.

Fast extended focused imaging in digital holography using a graphics processing unit.

We present a simple and effective method for reconstructing extended focused images in digital holography using a graphics processing unit (GPU). The Fresnel transform method is simplified by an algorithm named fast Fourier transform pruning with frequency shift. Then the pixel size consistency problem is solved by coordinate transformation and combining the subpixel resampling and the fast Fourier transform pruning with frequency shift. With the assistance of the GPU, we implemented an improved parallel version of this method, which obtained about a 300-500-fold speedup compared with central processing unit codes.

Effects of Yunanan Baiyao adjunct therapy on postoperative recovery and clinical prognosis of patients with traumatic brain injury: A randomized controlled trial.

BACKGROUND: Effective therapies are needed to prevent the secondary injury and poor prognosis associated with emergency craniotomy of traumatic brain injury (TBI). HYPOTHESIS/PURPOSE: The wound-healing medicine Yunnan Baiyao (YB) and Xingnaojing (XNJ) adjunct-therapy may improve the outcome of orthodox mono-therapy (OT). STUDY DESIGN: Randomized controlled trial. METHODS: Eighty patients with moderate-to-severe TBI received emergency craniotomy (within 12 h after TBI) at the Chinese PLA General Hospital before being randomly assigned to 4 different treatments (n = 20) for 7 days: 1) OT; 2) OT+XNJ (i.v. 20 ml/daily); 3) OT+low dose-YB (oral, 1,000 mg/day); 4) OT+high dose-YB, 2,000 mg/day). RESULTS: GCS score was improved more quickly and became significantly higher in XNJ, l-YB, h-YB groups than in OT group (p<0.01). Serum S100B peaked higher but declined more slowly in OT group than in other groups (p<0.01). On postoperative Day 7, S100B was 20% below baseline in YB and XNJ groups but remained 19% above baseline in OT group which also lost 38% of superoxide dismutase (SOD) activity on Day 3 and recovered 69% of SOD on Day 7 whereas the YB and XNJ groups lost 16%∼23% of SOD activity on Day 3 and recovered 92%∼99% of SOD on Day 7 (p<0.01). Clinical prognosis (Glasgow Outcome Scale and Karnofsky Performance Scale) were significantly better (25%∼30%) in the XNJ, l-YB and h-YB groups than in OT group 3 months post-surgery and were correlated with serum S100B and SOD. CONCLUSIONS: YB and XNJ adjunct therapies improved postoperative recovery and clinical prognosis in patients with moderate-to-severe TBI partly through divergent regulation of S100B and SOD pathways. (The trial was registered at Chinese Clinical Trial Registry (ChiCTR) trial registration number: ChiCTR2000030280).