SD-RLK28 positively regulates pollen hydration on stigmas as a PCP-Bß receptor in Arabidopsis thaliana.

Pollen hydration on dry stigmas is strictly regulated by pollen-stigma interactions in Brassicaceae. Although several related molecular events have been described, the molecular mechanism underlying pollen hydration remains elusive. Multiple B-class pollen coat proteins (PCP-Bs) are involved in pollen hydration. Here, by analyzing the interactions of two PCP-Bs with three Arabidopsis thaliana stigmas strongly expressing S-domain receptor kinase (SD-RLK), we determined that SD-RLK28 directly interacts with PCP-Bß. We investigated pollen hydration, pollen germination, pollen tube growth, and stigma receptivity in the sd-rlk28 and pcp-bß mutants. PCP-Bß acts in the pollen to regulate pollen hydration on stigmas. Loss of SD-RLK28 had no effect on pollen viability, and sd-rlk28 plants had normal life cycles without obvious defects. However, pollen hydration on sd-rlk28 stigmas was impaired and pollen tube growth in sd-rlk28 pistils was delayed. The defect in pollen hydration on sd-rlk28 stigmas was independent of changes in reactive oxygen species levels in stigmas. These results indicate that SD-RLK28 functions in the stigma as a PCP-Bß receptor to positively regulate pollen hydration on dry stigmas.

Genome-wide identification of the valine-glutamine motif containing gene family and the role of VQ25-1 in pollen germination in Brassica oleracea.

BACKGROUND: The plant-specific valine-glutamine (VQ) motif containing proteins tightly regulate plant growth, development, and stress responses. However, the genome-wide identification and functional analysis of Brassica oleracea (B. oleracea) VQ genes have not been reported. OBJECTIVE: To identify the VQ gene family in B. oleracea and analyze the function of Bo25-1 in pollen germination. METHODS: The Hidden Markov Model (HMM) of VQ family was used to query the BoVQ genes in the B. oleracea genome. The BoVQ genes preferentially expressed in anthers were screened by qRT-PCR. Subcellular localization of VQ25-1 was observed in Nicotiana benthamiana (N. benthamiana) leaves. To analysis the role of BoVQ25-1 in pollen germination, the expression of BoVQ25-1 was suppressed using antisense-oligonucleotides (AS-ODN). RESULTS: A total of 64 BoVQ genes were identified in the B. oleracea genome. BoVQ25-1 was found to be preferentially expressed in the B. oleracea anthers. BoVQ25-1 was cloned from the anthers of the B. oleracea cultivar 'Fast Cycle'. BoVQ25-1 is localized to the nucleus. The pollen germination rate significantly decreased after AS-ODN treatment. CONCLUSION: Sixty-four BoVQ genes were identified in the B. oleracea genome, of which BoVQ25-1 plays an important role in pollen germination.

X-ray attenuation of bone, soft and adipose tissue in CT from 70 to 140 kV and comparison with 3D printable additive manufacturing materials.

Additive manufacturing and 3D printing are widely used in medical imaging to produce phantoms for image quality optimization, imaging protocol definition, comparison of image quality between different imaging systems, dosimetry, and quality control. Anthropomorphic phantoms mimic tissues and contrasts in real patients with regard to X-ray attenuation, as well as dependence on X-ray spectra. If used with different X-ray energies, or to optimize the spectrum for a certain procedure, the energy dependence of the attenuation must replicate the corresponding energy dependence of the tissues mimicked, or at least be similar. In the latter case the materials' Hounsfield values need to be known exactly to allow to correct contrast and contrast to noise ratios accordingly for different beam energies. Fresh bovine and porcine tissues including soft and adipose tissues, and hard tissues from soft spongious bone to cortical bone were scanned at different energies, and reference values of attenuation in Hounsfield units (HU) determined. Mathematical model equations describing CT number dependence on kV for bones of arbitrary density, and for adipose tissues are derived. These data can be used to select appropriate phantom constituents, compare CT values with arbitrary phantom materials, and calculate correction factors for phantoms consisting of materials with an energy dependence different to the tissues. Using data on a wide number of additive manufacturing and 3D printing materials, CT numbers and their energy dependence were compared to those of the tissues. Two commercially available printing filaments containing calcium carbonate powder imitate bone tissues with high accuracy at all kV values. Average adipose tissue can be duplicated by several off-the-shelf printing polymers. Since suitable printing materials typically exhibit a too high density for the desired attenuation of especially soft tissues, controlled density reduction by underfilling might improve tissue equivalence.

Age differences in the association between marital status and hypertension: a population-based study.

The findings on the relationship between marital status and hypertension are inconsistent. We aimed to explore age differences in their associations. We used Hainan Hypertension Survey data, including 13,088 individuals aged more than 25 years, as part of the China Hypertension Survey study, a population-based nationwide study. The marital status was classified as following three groups: the unmarried, the married, and those who formerly lived with his/her spouse. We examined the association between marital status and blood pressure levels and the odds of hypertension across different ages and sex. The participants' mean age was 49.9 ± 17 years, 49% were male, and 23% experienced hypertension. The multivariable logistic regression model showed among younger (<40 years) and older (≥60 years) participants, the married subjects appeared to have higher odds of hypertension compared with the unmarried counterparts, particular for men (Pheterogeneity = 0.039), after adjustment for age, sex, smoking, drinking, education background, employment situation, and body mass index. Compared with the unmarried and the married people, younger persons who previously had partners had a higher OR of hypertension than the older counterparts, and the ORs tended to decline with age (All Ptrend ≤ 0.005). The associations between marital status and blood pressure levels from multivariable linear regression models seemed consistent with the relationships mentioned above from logistic regression models. Our study indicates a marital status change is associated with a higher odds of hypertension, and it appears to be more obvious in young people.

Classification of X-Ray Attenuation Properties of Additive Manufacturing and 3D Printing Materials Using Computed Tomography From 70 to 140 kVp.

Additive manufacturing and 3D printing is particularly useful in the production of phantoms for medical imaging applications including determination and optimization of (diagnostic) image quality and dosimetry. Additive manufacturing allows the leap from simple slab and stylized to (pseudo)-anthropomorphic phantoms. This necessitates the use of materials with x-ray attenuation as close as possible to that of the tissues or organs mimicked. X-ray attenuation properties including their energy dependence were determined for 35 printing materials comprising photocured resins and thermoplastic polymers. Prior to measuring x-ray attenuation in CT from 70 to 140 kVp, printing parameters were thoroughly optimized to ensure maximum density avoiding too low attenuation due to microscopic or macroscopic voids. These optimized parameters are made available. CT scanning was performed in a water filled phantom to guarantee defined scan conditions and accurate HU value determination. The spectrum of HU values covered by polymers printed using fused deposition modeling reached from -258 to +1,063 at 120 kVp (-197 to +1,804 at 70 kVp, to -266 to +985 at 140 kVp, respectively). Photocured resins covered 43 to 175 HU at 120 kVp (16-156 at 70, and 57-178 at 140 kVp). At 120 kVp, ASA mimics water almost perfectly (+2 HU). HIPS (-40 HU) is found close to adipose tissue. In all photocurable resins, and 17 printing filaments HU values decreased with increasing beam hardness contrary to soft tissues except adipose tissue making it difficult to mimic water or average soft tissue in phantoms correctly over a range of energies with one single printing material. Filled filaments provided both, the HU range, and an appropriate energy dependence mimicking bone tissues. A filled material with almost constant HU values was identified potentially allowing mimicking soft tissues by reducing density using controlled under-filling. The measurements performed in this study can be used to design phantoms with a wide range of x-ray contrasts, and energy dependence of these contrasts by combining appropriate materials. Data provided on the energy dependence can also be used to correct contrast or contrast to noise ratios from phantom measurements to real tissue contrasts or CNRs.

Tunable Photoluminescence and Energy Transfer Efficiency in ß-Ca3(PO4)2-Ca9La(PO4)7:Eu2+, Mn2+ Solid Solution Phosphors Introduced by Emptying Site and Structural Confinement Effect for Solid-State Lighting Application.

Full visible emission achieved by a single-phased system is of great interest to researchers for the development of high-quality solid-state lighting devices. Herein, novel Eu2+ and Mn2+ co-doped (1 - x)ß-Ca3(PO4)2-xCa9La(PO4)7 solid solution phosphors are designed to realize single-phased white light emission. The effects of variational x on lattice structure, color-tunable emission, thermal stability, and energy-transfer efficiency from Eu2+ to Mn2+ are systematically investigated. Tunable color emissions are achieved by manipulating the redistributions of Eu2+ ions among the different cationic sites under the influence of generated empty site in the M(4) site. Meanwhile, the changes of critical distances among the Eu2+ and Mn2+ caused by the variational x results in the changes of energy-transfer efficiency from different Eu2+ luminescent centers to Mn2+ due to the existence of structural confinement effect. The calculated results indicate that Eu1-Mn and Eu2-Mn possess higher energy-transfer efficiencies than other Eu-Mn pairs. Under the combined influence of the two effects, single-phased full visible white emission covering from 400 to 700 nm has been realized via the adjustment of solid solution, which makes the fabricated white-light-emitting diode (WLED) possess high color-rendering index (86.9) and R9 (87.2) as well as low correlated color temperature (3947 K). The results show that the 0.2ß-Ca3(PO4)2-0.8Ca9La(PO4)7:0.01Eu2+, 0.20Mn2+ could act as a promising phosphor for single-phased WLEDs. This work will open up a new avenue for tuning the multiple activator sites and energy-transfer efficiencies simultaneously to realize single-phased full visible white emission.