Exogenous methylglyoxal alleviates drought-induced 'plant diabetes' and leaf senescence in maize.

Drought-induced leaf senescence is associated with high sugar levels, which bears some resemblance to the syndrome of diabetes in humans; however, the underlying mechanisms of such 'plant diabetes' on carbon imbalance and the corresponding detoxification strategy are not well understood. Here, we investigated the regulatory mechanism of exogenous methylglyoxal (MG) on 'plant diabetes' in maize plants under drought stress applied via foliar spraying during the grain-filling stage. Exogenous MG delayed leaf senescence and promoted photoassimilation, thereby reducing the yield loss induced by drought by 14%. Transcriptome and metabolite analyses revealed that drought increased sugar accumulation in leaves through inhibition of sugar transporters that facilitate phloem loading. This led to disequilibrium of glycolysis and overaccumulation of endogenous MG. Application of exogenous MG up-regulated glycolytic flux and the glyoxalase system that catabolyses endogenous MG and glycation end-products, ultimately alleviating 'plant diabetes'. In addition, the expression of genes facilitating anabolism and catabolism of trehalose-6-phosphate was promoted and suppressed by drought, respectively, and exogenous MG reversed this effect, implying that trehalose-6-phosphate signaling in the mediation of 'plant diabetes'. Furthermore, exogenous MG activated the phenylpropanoid biosynthetic pathway, promoting the production of lignin and phenolic compounds, which are associated with drought tolerance. Overall, our findings indicate that exogenous MG activates defense-related pathways to alleviate the toxicity derived from 'plant diabetes', thereby helping to maintain leaf function and yield production under drought.

Genomic basis determining root system architecture in maize.

KEY MESSAGE: A total of 389 and 344 QTLs were identified by GWAS and QTL mapping explaining accumulatively 32.2-65.0% and 23.7-63.4% of phenotypic variation for 14 shoot-borne root traits using more than 1300 individuals across multiple field trails. Efficient nutrient and water acquisition from soils depends on the root system architecture (RSA). However, the genetic determinants underlying RSA in maize remain largely unexplored. In this study, we conducted a comprehensive genetic analysis for 14 shoot-borne root traits using 513 inbred lines and 800 individuals from four recombinant inbred line (RIL) populations at the mature stage across multiple field trails. Our analysis revealed substantial phenotypic variation for these 14 root traits, with a total of 389 and 344 QTLs identified through genome-wide association analysis (GWAS) and linkage analysis, respectively. These QTLs collectively explained 32.2-65.0% and 23.7-63.4% of the trait variation within each population. Several a priori candidate genes involved in auxin and cytokinin signaling pathways, such as IAA26, ARF2, LBD37 and CKX3, were found to co-localize with these loci. In addition, a total of 69 transcription factors (TFs) from 27 TF families (MYB, NAC, bZIP, bHLH and WRKY) were found for shoot-borne root traits. A total of 19 genes including PIN3, LBD15, IAA32, IAA38 and ARR12 and 19 GWAS signals were overlapped with selective sweeps. Further, significant additive effects were found for root traits, and pyramiding the favorable alleles could enhance maize root development. These findings could contribute to understand the genetic basis of root development and evolution, and provided an important genetic resource for the genetic improvement of root traits in maize.

Effectiveness and safety of azvudine in older adults with mild and moderate COVID-19: a retrospective observational study.

BACKGROUND: Azvudine has clinical benefits and acceptable safety against COVID-19, including in patients with comorbidities, but there is a lack of available data for its use in older adult patients. This study explored the effectiveness and safety of azvudine in older adults with mild or moderate COVID-19. METHODS: This retrospective cohort study included patients aged ≥80 diagnosed with COVID-19 at the Central Hospital of Shaoyang between October and November 2022. According to the therapies they received, the eligible patients were divided into the azvudine, nirmatrelvir/ritonavir, and standard-of-care (SOC) groups. The outcomes were the proportion of patients progressing to severe COVID-19, time to nucleic acid negative conversion (NANC), and the 5-, 7-, 10-, and 14-day NANC rates from admission. RESULTS: The study included 55 patients treated with azvudine (n = 14), nirmatrelvir/ritonavir (n = 18), and SOC (n = 23). The median time from symptom onset to NANC of the azvudine, nirmatrelvir/ritonavir, and SOC groups was 14 (range, 6-25), 15 (range, 11-24), and 19 (range, 18-23) days, respectively. The median time from treatment initiation to NANC of the azvudine and nirmatrelvir/ritonavir groups was 8 (range, 4-20) and 9 (range, 5-16) days, respectively. The median length of hospital stay in the three groups was 10.5 (range, 5-23), 13.5 (range, 10-21), and 17 (range, 10-23) days, respectively. No treatment-related adverse events or serious adverse events were reported. CONCLUSION: Azvudine showed satisfactory effectiveness and acceptable safety in older adults with mild or moderate COVID-19. Therefore, azvudine could be a treatment option for this special patient population.

A transcriptional landscape underlying sugar import for grain set in maize.

Developing seed depends on sugar supply for its growth and yield formation. Maize (Zea mays L.) produces the largest grains among cereals. However, there is a lack of holistic understanding of the transcriptional landscape of genes controlling sucrose transport to, and utilization within, maize grains. By performing in-depth data mining of spatio-temporal transcriptomes coupled with histological and heterologous functional analyses, we identified transporter genes specifically expressed in the maternal-filial interface, including (i) ZmSWEET11/13b in the placento-chalazal zone, where sucrose is exported into the apoplasmic space, and (ii) ZmSTP3, ZmSWEET3a/4c (monosaccharide transporters), ZmSUT1, and ZmSWEET11/13a (sucrose transporters) in the basal endosperm transfer cells for retrieval of apoplasmic sucrose or hexoses after hydrolysis by extracellular invertase. In the embryo and its surrounding regions, an embryo-localized ZmSUT4 and a cohort of ZmSWEETs were specifically expressed. Interestingly, drought repressed those ZmSWEETs likely exporting sucrose but enhanced the expression of most transporter genes for uptake of apoplasmic sugars. Importantly, this drought-induced fluctuation in gene expression was largely attenuated by an increased C supply via controlled pollination, indicating that the altered gene expression is conditioned by C availability. Based on the analyses above, we proposed a holistic model on the spatio-temporal expression of genes that likely govern sugar transport and utilization across maize maternal and endosperm and embryo tissues during the critical stage of grain set. Collectively, the findings represent an advancement towards a holistic understanding of the transcriptional landscape underlying post-phloem sugar transport in maize grain and indicate that the drought-induced changes in gene expression are attributable to low C status.

The allelic rice immune receptor Pikh confers extended resistance to strains of the blast fungus through a single polymorphism in the effector binding interface.

Arms race co-evolution drives rapid adaptive changes in pathogens and in the immune systems of their hosts. Plant intracellular NLR immune receptors detect effectors delivered by pathogens to promote susceptibility, activating an immune response that halts colonization. As a consequence, pathogen effectors evolve to escape immune recognition and are highly variable. In turn, NLR receptors are one of the most diverse protein families in plants, and this variability underpins differential recognition of effector variants. The molecular mechanisms underlying natural variation in effector recognition by NLRs are starting to be elucidated. The rice NLR pair Pik-1/Pik-2 recognizes AVR-Pik effectors from the blast fungus Magnaporthe oryzae, triggering immune responses that limit rice blast infection. Allelic variation in a heavy metal associated (HMA) domain integrated in the receptor Pik-1 confers differential binding to AVR-Pik variants, determining resistance specificity. Previous mechanistic studies uncovered how a Pik allele, Pikm, has extended recognition to effector variants through a specialized HMA/AVR-Pik binding interface. Here, we reveal the mechanistic basis of extended recognition specificity conferred by another Pik allele, Pikh. A single residue in Pikh-HMA increases binding to AVR-Pik variants, leading to an extended effector response in planta. The crystal structure of Pikh-HMA in complex with an AVR-Pik variant confirmed that Pikh and Pikm use a similar molecular mechanism to extend their pathogen recognition profile. This study shows how different NLR receptor alleles functionally converge to extend recognition specificity to pathogen effectors.

Residential proximity to major roadways and hearing impairment in Chinese older adults: a population-based study.

BACKGROUND: With rapid urban sprawl, growing people are living in the vicinity of major roadways. However, little is known about the relationship between residential proximity to major roadways and hearing impairment (HI). METHODS: We derived data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, and included 13,775 participants aged 65 years or older. Multivariate logistic regressions were employed to examine the association between residential proximity to major roadways and HI. The effects of corresponding potentially modifiable factors were studied by three-way interaction analyses. Sensitivity analyses were performed to verify the robustness of the results. RESULTS: The prevalence of HI was 38.3%. Participants living near major roadways were more likely to have a higher socioeconomic status. An exposure-response relation between residential proximity to major roadways and HI was observed (Ptrend < 0.05). Compared with individuals living > 300 m away from major roadways, the adjusted odds ratios (OR) were 1.07 (95% CI: 0.96-1.24), 1.15 (95% CI: 1.07-1.34), and 1.12 (95% CI: 1.01-1.31) for those living 101-200 m, 50-100 m, and < 50 m away from the roadways, respectively. Particularly, the association was more pronounced among individuals exposed to carbon monoxide (CO) pollution or opening windows frequently (Pinteraction < 0.05). Three-way interaction analyses confirmed that participants exposed to CO pollution and frequently leaving windows open had the highest OR of 1.73 (95% CI: 1.58-1.89). CONCLUSIONS: This nation-wide cohort study suggested that residential proximity to major roadways was significantly associated with an increased exposure-response risk of HI in Chinese older adults. Exposure to CO pollution and opening windows frequently might strengthen the relations.

Effect of Reaction Temperature on the Microstructure and Properties of Magnesium Phosphate Chemical Conversion Coatings on Titanium.

Magnesium phosphate (MgP) has garnered growing interest in hard tissue replacement processes due to having similar biological characteristics to calcium phosphate (CaP). In this study, an MgP coating with the newberyite (MgHPO4·3H2O) was prepared on the surface of pure titanium (Ti) using the phosphate chemical conversion (PCC) method. The influence of reaction temperature on the phase composition, microstructure, and properties of coatings was systematically researched with the use of an X-ray diffractometer (XRD), a scanning electron microscope (SEM), a laser scanning confocal microscope (LSCM), a contact angle goniometer, and a tensile testing machine. The formation mechanism of MgP coating on Ti was also explored. In addition, the corrosion resistance of the coatings on Ti was researched by assessing the electrochemical behavior in 0.9% NaCl solution using an electrochemical workstation. The results showed that temperature did not obviously affect the phase composition of the MgP coatings, but affected the growth and nucleation of newberyite crystals. In addition, an increase in reaction temperature had a great impact on properties including surface roughness, thickness, bonding strength, and corrosion resistance. Higher reaction temperatures resulted in more continuous MgP, larger grain size, higher density, and better corrosion resistance.

The Piks allele of the NLR immune receptor Pik breaks the recognition of AvrPik effectors of rice blast fungus.

Arms race co-evolution of plant-pathogen interactions evolved sophisticated recognition mechanisms between host immune receptors and pathogen effectors. Different allelic haplotypes of an immune receptor in the host mount distinct recognition against sequence or non-sequence related effectors in pathogens. We report the molecular characterization of the Piks allele of the rice immune receptor Pik against rice blast pathogen, which requires two head-to-head arrayed nucleotide-binding sites and leucine-rich repeat proteins. Like other Pik alleles, both Piks-1 and Piks-2 are necessary and sufficient for mediating resistance. However, unlike other Pik alleles, Piks does not recognize any known AvrPik variants of Magnaporthe oryzae. Sequence analysis of the genome of an avirulent isolate V86010 further revealed that its cognate avirulence (Avr) gene most likely has no significant sequence similarity to known AvrPik variants. Piks-1 and Pikm-1 have only two amino acid differences within the integrated heavy metal-associated (HMA) domain. Pikm-HMA interacts with AvrPik-A, -D, and -E in vitro and in vivo, whereas Piks-HMA does not bind any AvrPik variants. Characterization of two amino acid residues differing Piks-1 from Pikm-1 reveal that Piks-E229Q derived from the exchange of Glu229 to Gln229 in Piks-1 gains recognition specificity against AvrPik-D but not AvrPik-A or -E, indicating that Piks-E229Q partially restores the Pikm spectrum. By contrast, Piks-A261V derived from the exchange of Ala261 to Val261 in Piks-1 retains Piks recognition specificity. We conclude that Glu229 in Piks-1 is critical for Piks breaking the canonical Pik/AvrPik recognition pattern. Intriguingly, binding activity and ectopic cell death induction is maintained between Piks-A261V and AvrPik-D, implying that positive outcomes from ectopic assays might be insufficient to deduce its immune activity against the relevant effectors in rice and rice blast interaction.

[Clinical Analysis of Voriconazole Concentrations in Cerebrospinal Fluid and Blood in Patients with Ryptococcal Meningitis].

Objective: To investigate the concentrations of voriconazole (VCZ) in the central nervous system (CNS) of patients with cryptococcal meningitis and the relationship thereof. Methods: We retrospectively analyzed the trough concentration of VCZ in the cerebrospinal fluid (CSF) and the blood of 25 adult patients who had cryptococcal meningitis, and who were not infected with HIV. We also examined patient-level characteristics that could contribute to the differences in CSF/plasma VCZ concentration ratio. Results: The trough concentration of VCZ in plasma ranged from 0.38 to 8.56 mg/L, and the median (P 25, P 75) was 1.81 (1.40, 3.84) mg/L. The trough concentration of VCZ in CSF ranged from 0.17 to 3.92 mg/L, and the median (P 25, P 75) was 1.02 (0.54, 1.84) mg/L. The CSF VCZ trough concentration showed a slight negative correlation with the nucleated cell counts in CSF, but the correlation was not statistically significant ( r=-0.377, P=0.063). There was a positive correlation between VCZ concentrations in CSF and that in the plasma ( r=0.736, P<0.001), and the median (P 25, P 75) CSF/plasma ratio was 0.43 (0.34, 0.68). The CSF/plasma ratio did not statistically correlate with age, body surface area (BSA), radiology changes (hydrocephalus), or intracranial pressure. Conclusion: There is a positive correlation between VCZ concentration in CSF and VCZ concentration in the plasma, and no influencing factors of CSF/plasma ratio were found.

Engineering of rice varieties with enhanced resistances to both blast and bacterial blight diseases via CRISPR/Cas9.

Rice blast and bacterial blight represent two of major diseases having devastating impact on the yield of rice in most rice-growing countries. Developments of resistant cultivars are the most economic and effective strategy to control these diseases. Here, we used CRISPR/Cas9-mediated gene editing to rapidly install mutations in three known broad-spectrum blast-resistant genes, Bsr-d1, Pi21 and ERF922, in an indica thermosensitive genic male sterile (TGMS) rice line Longke638S (LK638S). We obtained transgene-free homozygous single or triple mutants in T1 generations. While all single and triple mutants showed increased resistance to rice blast compared with wild type, the erf922 mutants displayed the strongest blast resistance similar with triple mutants. Surprisingly, we found that Pi21 or ERF922 single mutants conferred enhanced resistance to most of tested bacterial blight. Both resistances in mutants were attribute to the up-regulation of SA- and JA-pathway associated genes. Moreover, phenotypic analysis of these single mutants in paddy fields revealed that there were no trade-offs between resistances and main agricultural traits. Together, our study provides a rapid and effective way to generate rice varieties with resistance to both rice blast and bacterial blight.

Causality of genetically determined metabolites on anxiety disorders: a two-sample Mendelian randomization study.

BACKGROUND: Although anxiety disorders are one of the most prevalent mental disorders, their underlying biological mechanisms have not yet been fully elucidated. In recent years, genetically determined metabolites (GDMs) have been used to reveal the biological mechanisms of mental disorders. However, this strategy has not been applied to anxiety disorders. Herein, we explored the causality of GDMs on anxiety disorders through Mendelian randomization study, with the overarching goal of unraveling the biological mechanisms. METHODS: A two-sample Mendelian randomization (MR) analysis was implemented to assess the causality of GDMs on anxiety disorders. A genome-wide association study (GWAS) of 486 metabolites was used as the exposure, whereas four different GWAS datasets of anxiety disorders were the outcomes. Notably, all datasets were acquired from publicly available databases. A genetic instrumental variable (IV) was used to explore the causality between the metabolite and anxiety disorders for each metabolite. The MR Steiger filtering method was implemented to examine the causality between metabolites and anxiety disorders. The standard inverse variance weighted (IVW) method was first used for the causality analysis, followed by three additional MR methods (the MR-Egger, weighted median, and MR-PRESSO (pleiotropy residual sum and outlier) methods) for sensitivity analyses in MR analysis. MR-Egger intercept, and Cochran's Q statistical analysis were used to evaluate possible heterogeneity and pleiotropy. Bonferroni correction was used to determine the causative association features (P < 1.03 × 10-4). Furthermore, metabolic pathways analysis was performed using the web-based MetaboAnalyst 5.0 software. All statistical analysis were performed in R software. The STROBE-MR checklist for the reporting of MR studies was used in this study. RESULTS: In MR analysis, 85 significant causative relationship GDMs were identified. Among them, 11 metabolites were overlapped in the four different datasets of anxiety disorders. Bonferroni correction showing1-linoleoylglycerophosphoethanolamine (ORfixed-effect IVW = 1.04; 95% CI 1.021-1.06; Pfixed-effect IVW = 4.3 × 10-5) was the most reliable causal metabolite. Our results were robust even without a single SNP because of a "leave-one-out" analysis. The MR-Egger intercept test indicated that genetic pleiotropy had no effect on the results (intercept = - 0.0013, SE = 0.0006, P = 0.06). No heterogeneity was detected by Cochran's Q test (MR-Egger. Q = 7.68, P = 0.742; IVW. Q = 12.12, P = 0.436). A directionality test conducted by MR Steiger confirmed our estimation of potential causal direction (P < 0.001). In addition, two significant pathways, the "primary bile acid biosynthesis" pathway (P = 0.008) and the "valine, leucine, and isoleucine biosynthesis" pathway (P = 0.03), were identified through metabolic pathway analysis. CONCLUSION: This study provides new insights into the causal effects of GDMs on anxiety disorders by integrating genomics and metabolomics. The metabolites that drive anxiety disorders may be suited to serve as biomarkers and also will help to unravel the biological mechanisms of anxiety disorders.

FBG array based wavelength calibration scheme for Fourier domain mode-locked laser with pm resolution and hourly stability.

We demonstrate a fiber Bragg grating (FBG) array based wavelength calibration scheme for Fourier domain mode-locked (FDML) laser. The wavelength interval and the temperature feedback module of the FBG array are designed to ensure the reference stability of the wavelength calibration scheme. Combined with the calibration scheme, the FDML laser with a tunable wavelength range of ∼60 nm, a center wavelength of 1300 nm and a sweep frequency of 39.63 kHz is built up to demonstrate its feasibility. The FBG wavelength demodulation based on the calibrated FDML laser system shows a wavelength resolution of 2.76 pm and hourly stability of 10.22 pm.

Insertion/deletion polymorphism at angiotensin-converting enzyme gene in PTSD individuals and their reciprocal effects on blood pressure.

OBJECTIVES: The aim of the present study was to investigate relationships between insertion/deletion (I/D) polymorphism at angiotensin-converting enzyme gene (ACE) and post-traumatic stress disorder (PTSD), as well as their interactions on blood pressure. METHODS: Variants of ACE I/D were identified by polymerase chain reaction method and verified by DNA sequencing. PTSD symptoms were assessed by the PTSD Checklist-Civilian Version (PCL-C) based on DSM-IV-TR criteria among high school students at 6 months after the 2008 Wenchuan earthquake. RESULTS: Female subjects were found to have higher prevalence of PTSD and PCL-C scores than male counterparts in the II homozygotes (p = .038 for PTSD and p = .003 for PCL-C scores) and the ID heterozygotes (p = .000 for PTSD and p = .000 for PCL-C scores), but not in the DD homozygotes. Male subjects with the ID (p = .046) or the DD genotype (p = .039) had lower pulse pressure (PP) than the male II homozygotes, while the female II homozygotes had lower diastolic blood pressure (DBP) than the female DD homozygotes (p = .036). ACE I/D, PTSD, or PCL-C scores, as well as gender and BMI, were found to be the predictors of PP. CONCLUSIONS: These results indicate that there are interactions of ACE I/D and PTSD, together with gender and BMI, on PP. This finding may be the additional explanation for the heterogeneous relationships between PTSD and blood pressure, and suggest psychiatry care and different medication strategies for patients with comorbidities of PTSD and hypertension and with different genotypes of ACE I/D.

Serum levels of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in children with autism spectrum disorder. / å­¤ç‹¬ç—‡è°±ç³»éšœç¢å„¿ç«¥çš„è¡€æ¸ èƒ°å²›ç´ æ ·ç”Ÿé•¿å› å­-1å’Œèƒ°å²›ç´ æ ·ç”Ÿé•¿å› å­ç»“åˆè›‹ç™½-3æ°´å¹³ç ”ç©¶.

OBJECTIVES: To study the serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) in children with autism spectrum disorder (ASD) and their association with the core symptoms of ASD. METHODS: A total of 150 ASD children aged 2-7 years (ASD group) and 165 healthy children matched for age and sex (control group) who were recruited at the outpatient service of Chongqing Health Center for Women and Children were enrolled as subjects. Autism Behavior Checklist (ABC) and Childhood Autism Rating Scale (CARS) were used to evaluate the core symptoms of the ASD children. Chemiluminescence was used to measure the serum levels of IGF-1 and IGFBP-3 in both groups. RESULTS: The ASD group had a significantly lower serum level of IGF-1 than the control group (P<0.05). The children with severe ASD had significantly lower serum levels of IGF-1 and IGFBP-3 than those with mild-to-moderate ASD (P<0.001). For the children aged 2-3 years, the ASD group had a significantly lower serum level of IGF-1 than the control group (P<0.05). Boys had a significantly lower serum level of IGF-1 than girls in both ASD and control groups (P<0.05). The serum levels of IGF-1 and IGFBP-3 were negatively correlated with the total score of CARS (r=-0.32 and -0.40 respectively, P<0.001). CONCLUSIONS: The reduction in serum IGF-1 level in early childhood may be associated with the development of ASD, and the serum levels of IGF-1 and IGFBP-3 are associated with the core symptoms of ASD children.

Intervening in sibling competition for assimilates by controlled pollination prevents seed abortion under postpollination drought in maize.

During maize production, drought throughout the flowering stage usually induces seed abortion and yield losses. The influence of postpollination drought stress on seed abortion and its underlying mechanisms are not well characterized. By intervening in the competition for assimilates between kernel siblings under different degrees of postpollination drought stresses accompanied by synchronous pollination (SP) and incomplete pollination (ICP) approaches, the mechanisms of postpollination abortion were investigated at physiological and molecular levels. Upon SP treatment, up to 15% of the fertilized apical kernels were aborted in the drought-exacerbated competition for assimilates. The aborted kernels exhibited weak sucrose hydrolysis and starch synthesis but promoted the synthesis of trehalose-6-phosphate and ethylene. In ICP where basal pollination was prevented, apical kernel growth was restored with reinstated sucrose metabolism and starch synthesis and promoted sucrose and hexose levels under drought stress. In addition, the equilibrium between ethylene and polyamine in response to the drought and pollination treatments was associated with the abortion process. We conclude that competition for assimilates drives postpollination kernel abortion, whereas differences in sugar metabolism and the equilibrium between ethylene and polyamines may be relevant to the "live or die" choice of kernel siblings during this competition.

Seasonal and diurnal patterns of non-structural carbohydrates in source and sink tissues in field maize.

BACKGROUND: Carbohydrate partitioning and utilization is a key determinant of growth rate and of yield in plants and crops. There are few studies on crops in field conditions. In Arabidopsis, starch accumulation in leaves is a negative indicator of growth rate. RESULTS: Here, we wished to establish if starch accumulation in leaves could potentially be a marker for growth rate and yield in crops such as maize. We characterized daily patterns of non-structural carbohydrate (NSC) at different growth stages over two seasons for maize hybrids in the field. In 27 commercial hybrids, we found a significant negative relationship between residual starch in leaves and plant growth, but not with final yield and biomass. We then focused on three typical hybrids and established a method for calculation of C turnover in photosynthetic leaves that took into account photosynthesis, leaf area and NSC accumulation. The ratios of stored NSC decreased from approximately 15% to less than 4% with ongoing ontogeny changes from V7 to 28 days after pollination. CONCLUSION: The proportion rather than absolute amount of carbon partitioned to starch in leaves at all stages of development related well with yield and biomass accumulation. It is proposed that screening plants at an early vegetative growth stage such as V7 for partitioning into storage may provide a prospective method for maize hybrid selection. Our study provides the basis for further validation as a screening tool for yield.

Thermally aggravated photo-bleaching of BAC-Al in bismuth/erbium co-doped optical fiber.

The thermal effect upon the photo-bleaching of bismuth/erbium co-doped optical fiber (BEDF) containing Al has been investigated. The photo-bleaching effects of aluminum related bismuth active center (BAC-Al) in BEDF are studied from room temperature (RT) up to 350°C under the irradiation of a 980 nm laser. No visible bleaching of the luminescence associated with BAC-Al was observed at RT, but significant bleaching appeared at higher temperatures above 150°C under the same irradiation power. The underlying mechanism of significant thermal aggravation of photo-bleaching is discussed, and its impact needs to be considered in the design and application of optical amplifiers and lasers using Al-doped BEDF.

BAC activation by thermal quenching in bismuth/erbium codoped fiber.

We have investigated the thermal quenching effect on the bismuth active center (BAC) in a Bi/Er co-doped fiber (BEDF). The effects from varying quenching conditions are studied and discussed. We report, for the first time to our knowledge, a significant BAC activation achieved by thermal quenching. We observed that the peak luminescence at ∼1405 nm of the BAC associated with silica (BAC-Si) could be enhanced more than two times by thermal quenching. The experimental results indicate that thermal quenching could be an effective way for BAC activation of bismuth-doped fibers.

Highly Efficient and Selective Dissolution Separation of Fission Products by an Ionic Liquid [Hbet][Tf2N]: A New Approach to Spent Nuclear Fuel Recycling.

Here, we propose the use of carboxyl-functionalized ionic liquid, [Hbet][Tf2N], to separate the fission products from spent nuclear fuels. This innovative method allows the selective dissolution of neutron poisons, lanthanides oxide, as well as some fission products with high yield, leaving most of the UO2 matrix and minor actinides behind in the spent nuclear fuel and accomplishing the actinides recovery as a group. Water-saturated [Hbet][Tf2N] can dissolve lanthanides oxide from simulated spent nuclear fuel with a dissolution ratio of 100% at 40 °C. However, the dissolution of uranium is almost negligible (<1%) under the same conditions. This big difference in dissolution provides a novel separation approach to spent nuclear fuel recycling and may open new perspectives for spent nuclear fuel reprocessing. The recovery of Nd and U from metal-loaded ionic liquids and the recyclability of the ionic liquid [Hbet][Tf2N] have also been investigated. Furthermore, a U/ x value related to the lattice energy U of metal compound M xO y is used to elaborate the solubility. This work represents the first case for efficient fission products removal by selective dissolution, avoiding the complete dissolution of spent nuclear fuel, the producing of the large high-level radioactive waste, and reducing environmental hazards.

Delayed pollination and low availability of assimilates are major factors causing maize kernel abortion.

Selective seed abortion is a survival strategy adopted by many species that sacrifices some seeds to allow the remaining ones to set. While in evolutionary terms this is a successful approach, it causes huge losses to crop yields. A pollination time gap (PTG) has been suggested to be associated with position-related grain abortion. To test this hypothesis, we developed a novel approach to alter the natural pattern of maize (Zea mays L.) pollination and to examine the impact of PTGs on kernel growth and the underlying physiological basis. When apical and basal kernels were synchronously pollinated, the basal kernels set and matured but the apical kernels were aborted at an early stage. Delaying pollination to the basal ovaries suppressed their development and reduced invertase activity and sugar levels, which allowed the apical kernels to set and grow normally. In situ localization revealed normal cell wall invertase activity in apical and basal kernels under synchronous pollination but reduced activity in the delayed-pollinated kernels independent of their position. Starch, which was abundant in basal kernel areas, was absent in the apical kernel regions under synchronous pollination but apparent with delayed pollination. Our analyses identified PTG-related sink strength and a low level of local assimilates as the main causes of grain abortion.