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Nitrogen (N), potassium (K), and phosphorus (P) are essential macronutrients for plant growth and development, and their availability affects crop yield. Compared with N, the relatively low availability of K and P in soils limits crop production and thus threatens food security and agricultural sustainability. Improvement of plant nutrient utilization efficiency provides a potential route to overcome the effects of K and P deficiencies. Investigation of the molecular mechanisms underlying how plants sense, absorb, transport, and use K and P is an important prerequisite to improve crop nutrient utilization efficiency. In this review, we summarize current understanding of K and P transport and signaling in plants, mainly taking Arabidopsis thaliana and rice (Oryza sativa) as examples. We also discuss the mechanisms coordinating transport of N and K, as well as P and N.

Summary Phosphorus, an essential mineral macronutrient, is a major constituent of fertilizers for maize (Zea mays L.) production. However, the molecular mechanisms of phosphate (Pi) acquisition in maize plants and its redistribution remain unclear. This study presents the functional characterization of ZmPT7 in Pi uptake and redistribution in maize. The ZmPT7 was expressed in roots and leaves, and induced during Pi starvation. The ZmPT7 complemented the Pi‐uptake deficiency of yeast mutant phoΔnull and Arabidopsis mutant pht1;1Δ4Δ, indicating that ZmPT7 functioned as a Pi transporter. We generated zmpt7 mutants by CRISPR/Cas9 and ZmPT7‐overexpressing lines. The zmpt7 mutants showed reduced, whereas the ZmPT7‐overexpressing lines displayed increased Pi‐uptake capacity and Pi redistribution from old to young leaves, demonstrating that ZmPT7 played central roles in Pi acquisition and Pi redistribution from old to young leaves. The ZmCK2 kinases phosphorylated ZmPT7 at Ser‐521 in old maize leaves, which enhanced transport activity of ZmPT7. The Ser‐520 of Arabidopsis AtPHT1;1, a conserved residue of ZmPT7 Ser‐521, was also phosphorylated by AtCK2 kinase, and the mutation of Ser‐520 to Glu (phosphorylation mimic) yielded enhanced transport activity of AtPHT1;1. Taken together, these results indicate that ZmPT7 plays important roles in Pi acquisition and redistribution, and its transport activity is modulated by phosphorylation.

Our study investigates the influence of career facilitators and barriers on nurses' improvement of their professional capabilities and their professional turnover intention.Reducing nurses' professional turnover intention could help alleviate the global nursing shortage. Nevertheless, little research has addressed how career facilitators and barriers, nurses' improvement of their professional capabilities and professional turnover intention are related, indicating a gap.This study used a cross-sectional design.We surveyed 502 out of 2,660 full-time nurses who worked for a medical centre in Taiwan between January-March 2018. Our items were adapted from Cunningham et al. and Teng et al. and had adequate reliability and validity. Structural equation modelling was used to test the study hypotheses.Human capital, social capital, and discrimination were positively related to intention to improve professional capabilities. Moreover, intention to improve professional capabilities was positively related to action to improve professional capabilities, which was negatively related to professional turnover intention.Most of the career facilitators and even barriers, boost the improvement of professional capabilities and are useful for retaining nurses in the nursing profession.Findings of this study should have an impact on nursing managers by offering them means to retain nurses, for example, enhancing human capital and social capital among nurses to reduce their turnover intention.目的: 我们的研究探讨了职业促进因素和障碍对护士专业能力提升和职业转换意愿的影响。 背景: 降低护士的职业转换意愿有助于缓解全球护士短缺问题。然而,很少有研究探讨职业促进因素与障碍、护士专业能力的提高与职业转换意愿之间的关系,这说明存在差距。 设计: 本研究使用了横向设计。 方法: 我们调查了2018年1月至3月期间在台湾一家医疗中心工作的2660名全职护士中的502人。我们的项目由Cunningham等人和Teng等人的研究改编而成,具有足够的信度和效度。结构方程模型用于验证研究假设。 结果: 人力资本、社会资本、歧视与提升专业能力的意愿呈正相关。提高专业能力的意愿与提高专业能力的行动呈正相关,与专业离职意愿呈负相关。 结论: 大多数的职业促进因素乃至障碍都促进了专业能力的提高,有利于在护理专业留住护士。 影响: 本研究的结果应该通过为他们提供留住护士的手段(如提高护士的人力资本和社会资本)来对护理管理者产生影响,以降低护士的离职意愿。.

We used otoliths, scales, pectoral fins, dorsal fins, basioccipital bones, opercular bones, interopercular bones, vertebrae, teeth, and cleithra sampled from 221 known-age Northern Snakeheads Channa argus argus representing five age-groups to determine and compare age estimation methods for this species. Results showed that accuracy of age estimation methods varied among structures: 85.68% of otoliths, 68.91% of scales, 49.25% of pectoral fin rays, and 27.67% of opercular bones yielded age estimates that were consistent with the actual fish ages. Ages determined from other structures, such as interopercular bones, dorsal fins, basioccipital bones, and vertebrae, had lower rates of agreement (

Objectives To investigate the contribution of magnetic resonance imaging (MRI) to the diagnosis of fetal cystic lung lesions found on routine prenatal ultrasound (US). Study Design Experienced radiologists retrospectively reviewed 34 fetal MRI studies performed in 20 fetuses (from 20 to 35 gestational weeks; including 14 repeat studies 10 weeks after the initial MRI), focusing on shape, signal characteristics, feeding artery, volume change, and location of the cystic lesions. Diagnoses were confirmed after birth by postnatal multidetector computed tomography (MDCT) and/or surgery. Results Bronchopulmonary sequestration (BPS) in the second trimester appeared as a well-defined, homogeneous, hyperintense mass (pure BPS) in eight cases or as a lobulated, inhomogeneous hyperintense mass (BPS mixed with congenital cystic adenomatoid malformation (CCAM)) in three cases. The feeding artery was visible in all 11 cases in the initial MRI, and regression of the mass was seen in 7 cases. As the mass regressed in the third trimester, the signal intensity decreased, becoming inhomogeneous, and the margins became lobulated. The mean initial ratio of the volume of the BPS lesion to the ipsilateral lung in lesions with partial regression was 82%; the mean initial ratio in lesions with nearly complete regression was 61%. CCAM (6) cases also appeared as a hyperintense lobulated mass, and as the lesions regressed, they decreased in size and signal intensity. As with BPS, the larger the lesion on initial MRI, the less likely it was to regress completely. Congenital lobar fluid overload in three cases appeared as a hyperintense, homogeneous lobe with stretched hilar vessels. Conclusion Prenatal MRI is useful as a diagnostic tool complementary to US for evaluating fetal cystic lung lesions. Smaller lung lesions (

Tissue-engineering approaches for treating degenerative intervertebral discs aim to regenerate intervertebral disc tissues in order to retard or even reverse the degenerative process. This study was designed to investigate the feasibility of the glutaraldehyde crosslinked gelatin/chondroitin-6-sulfate copolymer scaffold to serve as a bioactive scaffold for culturing human nucleus pulposus (NP) cells in vitro with preservation of the cell viability, cell proliferation, and production of important extracellular matrix, including glycoaminoglycans (GAG) and Type II collagen. Each experimental sample was seeded with 1 × 106 human NP cells, and then the cell–scaffold hybrids were cultured in vitro for 6 or 12 weeks. SEM showed a highly porous structure with an average pore size of 100 μm in the copolymer scaffold. Immediately after cell seeding, SEM showed that the seeded cells penetrated deeply and distributed evenly in the copolymer scaffold. Water-soluble tetrazolium salt-1 (WST-1) assay showed good viability and active proliferation of cultured human NP cells in the copolymer scaffolds up to 12 weeks. The cell–scaffold hybrids contained significantly higher levels of sulfated GAG than the control samples (41.29 μg vs 6.04 μg per scaffold). Immunohistochemical study showed Type II collagen fibrils on the surface of scaffold substrate after 6 weeks of cultivation. More abundant deposition of Type II collagen could be detected after 12 weeks. The results achieved in this study indicate that the gelatin/chondroitin-6-sulfate copolymer scaffold is a promising bioactive scaffold for regeneration of nucleus pulposus tissue. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005