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The development of the embryo sac is an important factor that affects seed setting in rice. Numerous genes associated with embryo sac (ES) development have been identified in plants; however, the function of the DEAD-box RNA helicase family genes is poorly known in rice. Here, we characterized a rice DEAD-box protein, RH52A, which is localized in the nucleus and cytoplasm and highly expressed in the floral organs. The knockout mutant rh52a displayed partial ES sterility, including degeneration of the ES (21%) and the presence of a double-female-gametophyte (DFG) structure (11.8%). The DFG developed from two functional megaspores near the chalazal end in one ovule, and 3.4% of DFGs were able to fertilize via the sac near the micropylar pole in rh52a. RH52A was found to interact with MFS1 and ZIP4, both of which play a role in homologous recombination in rice meiosis. RNA-sequencing identified 234 down-regulated differentially expressed genes associated with reproductive development, including two, MSP1 and HSA1b , required for female germline cell specification. Taken together, our study demonstrates that RH52A is essential for the development of the rice embryo sac and provides cytological details regarding the formation of DFGs. [ABSTRACT FROM AUTHOR]

Polyploid hybrid rice (Oryza sativa) has great potential for increasing yields. However, hybrid rice depends on male fertility and its regulation, which is less well studied in polyploid rice than in diploid rice. We previously identified an MYB transcription factor, MORE FLORET1 (MOF1), whose mutation causes male sterility in neo-tetraploid rice. MOF1 expression in anthers peaks at anther Stage 7 (S7) and progressively decreases to low levels at S10. However, it remains unclear how the dynamics of MOF1 expression contribute to male fertility. Here, we carefully examined anther development in both diploid and tetraploid mof1 rice mutants, as well as lines ectopically expressing MOF1 in a temporal manner. MOF1 mutations caused delayed degeneration of the tapetum and middle layer of anthers and aberrant pollen wall organization. Ectopic MOF1 expression at later stages of anther development led to retarded cytoplasmic reorganization of tapetal cells. In both cases, pollen grains were aborted and seed production was abolished, indicating that precise control of MOF1 expression is essential for male reproduction. We demonstrated that 5 key tapetal genes, CYP703A3 (CYTOCHROME P450 HYDROXYLASE 703A3), OsABCG26 (O. sativa ATP BINDING CASSETTE G26), PTC1 (PERSISTENT TAPETAL CELL1), PKS2 (POLYKETIDE SYNTHASE 2), and OsABCG15 (O. sativa ATP BINDING CASSETTE G15), exhibit expression patterns opposite to those of MOF1 and are negatively regulated by MOF1. Moreover, DNA affinity purification sequencing (DAP-seq), luciferase activity assays, and electrophoretic mobility shift assays indicated that MOF1 binds directly to the PKS2 promoter for transcriptional repression. Our results provide a mechanistic basis for the regulation of male reproduction by MOF1 in both diploid and tetraploid rice. This study will facilitate the development of polyploid male sterile lines, which are useful for breeding of polyploid hybrid rice. Male fertility in both diploid and polyploid rice requires spatiotemporal control of a MYB transcription factor that can be manipulated to create polyploid male sterile lines. [ABSTRACT FROM AUTHOR]

Understanding the regulation of autotetraploid sterility is essential for harnessing the strong advantages in genomic buffer capacity, biodiversity, and heterosis of autotetraploid rice. miRNAs play crucial roles in fertility regulation, yet information about their reproductive roles and target genes in tetraploid rice remains limited. Here, we used three tetraploid lines, H1 (fertile), HF (fertile), and LF (sterile), to investigate cytological features and identify factors associated with autotetraploid sterility. LF showed abnormal meiosis, resulting in low pollen fertility and viability, ultimately leading to scarce fertilization and a low-seed setting compared to H1 and HF. RNA-seq revealed 30 miRNA-candidate target pairs related to autotetraploid pollen sterility. These pairs showed opposite expression patterns, with differential expression between fertile lines (H1 and HF) and the sterile line (LF). qRT-PCR confirmed that miR9564, miR528, and miR27874 were highly expressed in the anthers of H1 and HF but not in LF, while opposite results were obtained in their targets (ARPS, M2T, and OsRPC53). Haplotype and expression pattern analyses revealed that ARPS was specifically expressed in lines with the same haplotype of MIR9564 (the precursor of miR9564) as LF. Furthermore, the Dual-GFP assay verified that miR9564 inhibited the fluorescence signal of ARPS-GFP. The over-expression of ARPS significantly decreased the seed setting rate (59.10%) and pollen fertility (50.44%) of neo-tetraploid rice, suggesting that ARPS plays important roles in autotetraploid pollen sterility. This study provides insights into the cytological characteristic and miRNA expression profiles of tetraploid lines with different fertility, shedding light on the role of miRNAs in polyploid rice. [ABSTRACT FROM AUTHOR]

This study investigates uranium solvent extraction under AMEX process conditions. The use of pure extractants without diluents or phase modifiers allows us not only to reduce the use of volatile organic compounds but also to provide higher extraction yields without third-phase formation. Pure extractants are protonated amines or quaternary ammoniums with suitable counter ions, which act at the interface between ion pairs and protic ionic liquids. The mixture of sulphates anion (SO42−) and bis(trifluoromethanesulfonyl)imide anion (NTf2−) revealed unexpected nonlinear extraction behaviors, which appear highly important to rationalize for optimized application. A spectroscopic analysis (NMR, UV-vis, FT-IR, and EXAFS) showed that uranium extraction occurs via a protonated amine and three sulphates. A nonlinear extraction could further be interpreted by considering a water and acid transfer between the two phases: at lower sulphate ratios, the release of acid from the organic phase into the aqueous phase was shown to influence the number of protonated amines in the organic phase, affecting uranium extraction before its enhancement. Furthermore, the extraction loss at higher sulphate ratios was assigned to the destabilization of bidentate uranium–sulphate complexes due to a competition between water and sulphates. [ABSTRACT FROM AUTHOR]

The topspin forehand is the most frequent and effective shot in top-level table tennis matches. The present study assesses the biomechanical differences in the topspin forehand stroke technique when the incoming ball is in different rotations. Eight national level-1 male table tennis athletes (176.6 ± 4.8 cm, 70.8 ± 6.6 kg, 20.9 ± 2.4 yr) performed two kinds of techniques—topspin forehand strokes against topspin (AT) and against backspin (AB) balls, respectively. The kinematic parameters of their bodies and rackets were calculated. Meanwhile, the force plates analyzed their lower limb moments through inverse dynamics. Paired t-test and non-parametric paired t-test mapping were used to assess the differences between the two conditions. Their center of gravity (COG) vertical distance, elbow flexion, thorax–pelvis flexion, and knee flexion angles had significant differences during the stroke phase (p < 0.05). The moment of the racket-side hip rotation and ankle dorsiflexion showed significant differences during the stroke phase (p < 0.05). The racket velocity, angle, and trajectories showed significant differences at characteristic moments (p < 0.05). This study revealed the different topspin forehand stroke techniques in table tennis, even though the two movements look similar. Compared with AT strokes, the athletes kept a straight elbow and lower center of gravity than they did during the stroke phase of AB strokes. They increased the distance of the racket trajectory and velocity to meet the incoming ball with a backspin, especially in the vertical direction. This detailed information is necessary for beginners to improve the efficiency of their forehand topspin technique, especially in strokes against incoming balls with different rotations. [ABSTRACT FROM AUTHOR]

Background: This study aimed to derive the effects of walking while using a mobile phone on balance perturbation and joint movement among young adults. Methods: Sixteen healthy college students with no history of brain injury were tested. The participants were asked to walk under four different conditions: (1) walking, (2) browsing, (3) dialing, and (4) texting. Indicators related to balance control and lower limb kinematic/kinetic parameters were analyzed using the continuous relative phase and statistical nonparametric mapping methods. Results: Walking while using a mobile phone slowed participants' gait speed and reduced the cadence, stride length, and step length. The posterior tilt angle (0–14%, 57–99%), torque of the hip flexion (0–15%, 30–35%, 75–100%), and angle of the hip flexion (0–28%, 44–100%) decreased significantly. The activation of biceps femoris and gastrocnemius, hip stiffness, and ankle stiffness increased significantly. This impact on gait significantly differed among three dual tasks: texting > browsing > dialing. Conclusion: Che overlap of walking and mobile phone use affects the gait significantly. The "hip–ankle strategy" may result in a "smooth" but slower gait, while this strategy was deliberate and tense. In addition, this adjustment also increases the stiffness of the hip and ankle, increasing the risk of fatigue. Findings regarding this effect may prove that even for young healthy adults, walking with mobile phone use induces measurable adjustment of the motor pattern. These results suggest the importance of simplifying the control of the movement. [ABSTRACT FROM AUTHOR]

Background: This study aims to investigate the associations between dietary patterns (breakfast, egg, dairy products, and sugared beverage intake frequencies) and physical fitness among Chinese children and adolescents in Shaanxi Province. METHODS: Data were extracted from the Chinese National Survey on Students' Constitution and Health (CNSSCH). The study ultimately included 7305 participants (48.4% male, 51.6% female) aged 6–22 in Shaanxi Province, China. Multiple linear regression was used to examine the association of the frequency of breakfast, egg, dairy product, and sugared beverage intakes with physical fitness. RESULTS: The frequency of breakfast, egg, and dairy product intakes were all independently and positively associated with the level of physical fitness. The frequency of sugared beverage intake was negatively associated with the level of physical fitness. CONCLUSION: Healthier dietary patterns (i.e., higher breakfast, egg, and dairy product intakes and lower sugared beverage intake) were associated with greater physical fitness. Specifically, maintaining a healthy dietary pattern of breakfast, egg, and dairy product intakes can positively affect the strength and endurance performance of children and adolescents. Increased dairy product intake plays a crucial part in boosting the physical fitness total scores of children and adolescents. [ABSTRACT FROM AUTHOR]

Background: This study aimed to explore the characteristics of trends in physical fitness and nutritional status among school-aged students during the COVID-19 pandemic, which could help to develop targeted guidelines and policies for students (adolescents) to promote health during lockdowns resulting from public health emergencies. Methods: The physical fitness and nutritional status were measured from 2019 to 2021; the correlation between years and grade were analyzed. Results: a declining trend was found in aerobic fitness, strength fitness, speed fitness, and BMI during this lockdown. Conclusion: The changes in dietary behavior and the decrease in outdoor physical activities may be the reason for the decline. Furthermore, differences in subjects' growth and limited space at home must be considered in the formulation of exercise and nutritional plans. According to the results of our study, exercise for aerobic fitness should receive more attention when students are enduring a pandemic lockdown. In addition, saying "no" to high-calorie foods in the form of snacking and ultra-processed food was the key to improving subjects' nutritional status. [ABSTRACT FROM AUTHOR]

Autotetraploid rice exhibited hybrid vigor and greater genetic variation compared to diploid rice, but low pollen fertility is a major hindrance for its utilization. Our previous analysis revealed that large number of pollen fertility genes were exhibited down-regulation in autotetraploid rice. Hence, it is of utmost importance to reveal the expression patterns of pollen fertility genes with high accuracy. To find stable reference genes for autotetraploid rice, we compared the pollen development stages between diploid and autotetraploid rice, and 14 candidate genes were selected based on transcriptome analysis to evaluate their expression levels. Autotetraploid rice (i.e. Taichung65-4x) displayed lower seed set (40.40%) and higher percentage of abnormalities during the pollen development process than its diploid counterpart. To detect the candidate reference genes for pollen development of autotetraploid and diploid rice, we used five different algorithms, including NormFinder, BestKeeper, ΔCt method, geNorm and Re-Finder to evaluate their expression patterns stability. Consequently, we identified two genes, Cytochrome b5 and CPI, as the best candidate reference genes for qRT-PCR normalization in autotetraploid and diploid rice during pre-meiosis, meiosis, single microspore and bicellular pollen development stages. However, Cytochrome b5 was found to be the most stably expressed gene during different pollen development stages in autotetraploid rice. The results of our study provide a platform for subsequent gene expression analyses in autotetraploid rice, which could also be used in other polyploid plants. [ABSTRACT FROM AUTHOR]

Grouper iridovirus (GIV) is one of the most serious pathogens in mariculture and causes high mortality rates in cultured groupers; then, effective medicines for controlling GIV infections are urgently needed. Viola philippica is a well‐known medicinal plant, and the application of V. philippica aqueous extracts against GIV infection was assessed by different methods in this study. The results showed that the working concentration of V. philippica aqueous extracts was 10 mg/ml. V. philippica aqueous extracts below 10 mg/ml have no significant cytotoxic effects on cell viability, while extracts over 15 mg/ml decreased cell viability and showed cytotoxic activity. V. philippica aqueous extracts had excellent inhibitory effects against GIV infection in vitro and in vivo. The possible antiviral mechanism of V. philippica was further analysed, which indicated that V. philippica did no damages to GIV particles, but it could disturb GIV binding, entry and replication in host cells. V. philippica had the best inhibitory effects against GIV during viral infection stage of binding and replication in host cells. Overall, the results suggest that appropriate concentration of V. philippica aqueous extracts has great antiviral effects, making it an interesting candidate for developing effective medicines for preventing and controlling GIV infection in farmed groupers. [ABSTRACT FROM AUTHOR]

Vibrio alginolyticus (V. alginolyticus) is a major opportunistic pathogen to both marine animals and humans, which has also caused heavy economic losses to mariculture. The aim of this study was to develop highly specific aptamers for V. alginolyticus. Single‐stranded DNA (ssDNA) aptamers with high binding affinity to viable V. alginolyticus were generated by Systematic Evolution of Ligands by Exponential Enrichment (SELEX) and identified by flow cytometric analysis in this study. The selected aptamers showed high specificity for V. alginolyticus and low apparent binding for other bacteria. The aptamers formed distinct stem‐loop structures, which could form the basis of aptamers' specific binding to the target V. alginolyticus. Aptamer VA2 and VA8 showed particularly high binding affinity constant (Kd) of 14.31 ± 4.26 and 90.00 ± 13.51 nM, respectively. The aptamers produced no cytotoxic effects in vitro and in vivo. ssDNA aptamers were successfully selected against the viable bacteria pathogen V. alginolyticus by SELEX. The aptamers selected in this study could be not only applied as specific chemical molecular probes for studying V. alginolyticus pathogenesis to Trachinotus ovatus, but also developing rapid convenient diagnosis assay for V. alginolyticus infection, even when applied to the complex sample matrix, such as food and environment samples. [ABSTRACT FROM AUTHOR]

Background. To study the effectiveness of exenatide with metformin and sequential treatment with exenatide and glargine added to metformin and their influence on insulin sensitivity and adipose distribution. Methods. 20 newly diagnosed obese type 2 diabetic patients were enrolled, and 2-month washout treatment of metformin, 6-month exenatide treatment, and 6-month glargine treatment were administrated sequentially accompanied with previous metformin. Glucolipid metabolic parameters were compared among groups. Adipose distribution was quantified with computerized tomography according to anatomy, dividing into visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), adding up to total adipose tissue (TAT). Results. The 6-month exenatide treatment dramatically ameliorated the glucose and lipid profile, improved insulin sensitivity, and mainly decreased VAT and also the ratio of VAT/SAT (RVS). The following 6-month glargine treatment increased VAT. The whole 12-month sequential treatment with exenatide and glargine added to metformin basically improved the insulin sensitivity and glucolipid control though VAT rebounded at the end, however without deteriorating the other parameters. Conclusion. Exenatide is an ideal treatment for obese type 2 diabetic patients in the aspect of adipose tissue distribution. Sequential treatment of exenatide and glargine could be an alternative for low-income patients who cannot afford GLP-1 agonist for long time. This trial is registered with ChiCTR-OOC-17013679. [ABSTRACT FROM AUTHOR]

Neo-tetraploid rice with high fertility is a useful germplasm for polyploid rice breeding, which was developed from the crossing of different autotetraploid rice lines. However, little information is available on the molecular mechanism underlying the fertility of neo-tetraploid rice. Here, two contrasting populations of tetraploid rice, including one with high fertility (hereafter referred to as JG) and another with low fertility (hereafter referred to as JD), were generated by crossing Huaduo 3 (H3), a high fertility neo-tetraploid rice that was developed by crossing Jackson-4x with 96025-4x, and Huajingxian74-4x (T452), a low fertility autotetraploid rice parent. Cytological, global genome sequencing-based bulked-segregant (BSA-seq) and CRISPR/Cas9 technology were employed to study the genes associated with pollen fertility in neo-tetraploid rice. The embryo sacs of JG and JD lines were normal; however, pollen fertility was low in JD, which led to scarce fertilization and low seed setting. Cytological observations displayed low pollen fertility (25.1%) and approximately 31.3 and 27.2% chromosome lagging at metaphase I and II, and 28.8 and 24.8% chromosome straggling at anaphase I and II in JD, respectively. BSA-seq of F2–3 generations and RNA-seq of F4 generation detected a common fragment, i.e., 18,915,234–19,500,000, at chromosome 7, which was comprised of 78 genes associated with fertility. Among 78 genes, 9 genes had been known to be involved in meiosis and pollen development. Two mutants ny1 (LOC_Os07g32406) and ny2 (LOC_Os07g32040) were generated by CRISPR/Cas9 knockout in neo-tetraploid rice, and which exhibited low pollen fertility and abnormal chromosome behavior. Our study revealed that two unknown genes, LOC_Os07g32406 (NY1) and LOC_Os07g32040 (NY2) play an important role in pollen development of neo-tetraploid rice and provides a new perspective about the genetic mechanisms of fertility in polyploid rice. [ABSTRACT FROM AUTHOR]

Autotetraploid rice is a useful rice germplasm for polyploid rice breeding. However, low fertility limits its commercial production. A neo-tetraploid rice with high fertility was developed from the progenies of crossing between autotetraploid lines by our research group. Our previous study showed that a myeloblastosis (MYB) transcription factor, MOF1, might be associated with the pollen development in tetraploid rice. However, little information is available about its role in pollen development in tetraploid rice. Here, we identified a new haplotype of MOF1 from neo-tetraploid rice and marked it as MOF1a. Transcriptome and qRT-PCR analysis demonstrated that MOF1a highly expressed in anthers, and displayed differential expression in neo-tetraploid rice compared to tetraploid rice line with low pollen fertility. The mutant (mof1a) of MOF1a, which was generated by CRISPR/Cas9 knockout in neo-tetraploid rice, showed low pollen fertility, and also exhibited abnormal tapetum and middle layer development, and defective chromosome behaviors during meiosis. A total of 13 tapetal related genes were found to be up-regulated in meiotic anthers of MOF1a compared with wild type plants by RNA-seq analysis, including CYP703A3, PTC1, and OsABCG26, which had been demonstrated to affect tapetal development. Moreover, 335 meiosis-related genes displayed differential expression patterns at same stage, including nine important meiosis-related genes, such as metallothionein OsMT1a. These results demonstrated that MOF1a plays an important role in pollen development and provides a foundation for understanding the molecular mechanism underlying MOF1a in reproduction of tetraploid rice. [ABSTRACT FROM AUTHOR]

Autotetraploid rice is a useful germplasm for polyploid rice breeding; however, low seed setting is a major hindrance for its utilization. Here, we reported the development of a new tetraploid rice, Huoduo1 (H1), which has the characteristic of high fertility, from crossing generations of autotetraploid rice. Cytological observations displayed the high fertility of the pollen (95.62%) in H1, a lower percentage of pollen mother cell (PMC) abnormalities, and stable chromosome configurations during the pollen development process compared with its parents. Using RNA-seq analysis, we detected 440 differentially expressed genes (DEGs) in H1 compared with its parents. Of these DEGs, 193 were annotated as pollen fertility-related genes, and 129 (~66.8%) exhibited significant up-regulation in H1 compared with the parents, including three environmentally sensitive genic male sterility genes (TMS9-1, TMS5, and CSA), one meiosis gene (RAD51D), and three tapetal-related genes (MIL2, OsAP25, and OsAP37), which were validated by qRT-PCR in this study. Two genes, TMS9-1 and TMS5, were knocked out using CRISPR/Cas9 technology, and their mutants displayed low fertility and the abnormal development of pollen. Our findings provide evidence for the regulatory mechanisms of fertility in tetraploid rice and indicated that the up-regulation of pollen fertility-related genes may contribute to the high fertility in new tetraploid rice. [ABSTRACT FROM AUTHOR]

Polyploid rice hybrids have a powerful biological and yield potential that may become a new way for rice breeding; however, low fertility is major hindrance in commercial utilization. Here, we developed a neo-tetraploid rice that could overcome the sterility of autotetraploid rice and produce high heterosis. Transcriptome analysis of F1 hybrid developed by crossing neo-tetraploid with autotetraploid rice displayed 807, 663 and 866 differentially expressed genes that uniquely associated with F1 and specific to (DEGFu-sp) anther, ovary and leaf, respectively. Of the DEGFu-sp, 1224 genes displayed nonadditive expression; 44 and 10 genes were annotated as TFs and methyltransferase or hydroxymethyltransferase, respectively. Gene ontology enrichment and co-expression analysis revealed specific differential gene expressions in the DEGFu-sp to leaf, anther and ovary, such as genes related to photosynthesis, metabolic process and transport, and co-expression network including fertility, resistance and epigenetic elements. Of the DEGFu-sp to anther, 42 meiosis stage-specific genes, eight meiosis-related genes, such as RAD51 and SMC2, were identified. We identified 38 miRNAs from DEGFu-sp to anther, and their targets were associated with pollen fertility and retrotransposon protein. Our study provides new germplasm for polyploid rice breeding, and revealed complex regulatory mechanisms that might be associated with heterosis and fertility. [ABSTRACT FROM AUTHOR]

Orlistat is a pancreatic lipase (PL) inhibitor that inhibits dietary lipid absorption and is used to treat obesity. The oral bioavailability of orlistat is considered zero after administration in standard formulations. This is advantageous in the treatment of obesity. However, if orlistat absorption could be improved it has the potential to treat diseases such as acute and critical illnesses where PL transport to the systemic circulation via gut lymph promotes organ failure. Orlistat is highly lipophilic and may associate with intestinal lipid absorption pathways into lymph. Here we investigate the potential to improve orlistat lymph and systemic uptake through intestinal administration in lipid formulations (LFs). The effect of lipid type, lipid dose, orlistat dose, and infusion time on lymph and systemic availability of orlistat was investigated. After administration in all LFs, orlistat concentrations in lymph were greater than in plasma, suggesting direct transport via lymph. Lymph and plasma orlistat derivative concentrations were ~8-fold greater after administration in a long-chain fatty acid (LC-FA) compared to a lipid-free, LC triglyceride (LC-TG) or medium-chain FA (MC-FA) formulation. Overall, administration of orlistat in a LC-FA formulation promotes lymph and systemic uptake which may enable treatment of diseases associated with elevated systemic PL activity. [ABSTRACT FROM AUTHOR]