Localization of BEN1-LIKE protein and nuclear degradation during development of metaphloem sieve elements in Triticum aestivum L.

Metaphloem sieve elements (MSEs) in the developing caryopsis of Triticum aestivum L. undergo a unique type of programmed cell death (PCD); cell organelles gradually degrade with the MSE differentiation while mature sieve elements keep active. This study focuses on locating BEN1-LIKE protein and nuclear degradation in differentiating MSEs of wheat. Transmission electron microscopy (TEM) showed that nuclei degraded in MSE development. First, the degradation started at 2–3 days after flowering (DAF). The degraded fragments were then swallowed by phagocytic vacuoles at 4 DAF. Finally, nuclei almost completely degraded at 5 DAF. We measured the BEN1-LIKE protein expression in differentiating MSEs. In situ hybridization showed that BEN1-LIKE mRNA was a more obvious hybridization signal at 3–4 DAF at the microscopic level. Immuno-electron microscopy further revealed that BEN1-LIKE protein was mainly localized in MSE nuclei. Furthermore, MSE differentiation was tested using a TSQ Zn2+ fluorescence probe which showed that the dynamic change of Zn2+ accumulation was similar to BEN1-LIKE protein expression. These results suggest that nucleus degradation in wheat MSEs is associated with BEN1-LIKE protein and that the expression of this protein may be regulated by Zn2+ accumulation variation

Crack propagation and strain-induced α’-martensite transformation in selective laser melting 316L stainless steels

At present, in-situ monitoring of metal cracking and propagation is still a challenge. In this work, we used in-situ tensile tests with precast cracks of selective laser melting (SLM) and conventionally manufactured (CM) 316L stainless steels (SSs) to study crack propagation and strain-induced α′-martensite transformation. During in-situ tensile, cracks initiate at the concentration of slip lines at the precast crack, and the strong stress at the crack tip will tear apart the grain boundaries causing the crack to propagate until the samples are completely fractured. After in-situ tensile, abnormal grain growth was observed in the plastic zone at the crack tip of the SLMed 316L SS sample, while austenite to α′-martensite transformation was appeared at the grain boundaries of the SLMed 316L SS sample, and martensitic patches generated by severe plastic deformation induced in the CM 316L SS were also observed. The SLMed 316L SS shows higher strength and resistance to deformation than CM 316L SS. In addition, the stress concentration at the crack tip in crack propagation has a significant effect on the transformation of strain-induced α′-martensite

A systematic review of the safety of tirzepatide-a new dual GLP1 and GIP agonist - is its safety profile acceptable?

AimsTirzepatide is a novel dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 receptor agonist (GLP-1 RA). At present, there is no controversy over its effectiveness, but its safety. We conducted a systematic review to assess the safety of tirzepatide.MethodsWe searched PubMed, Embase and Cochrane databases for randomized controlled trials (RCTs) of tirzepatide from databases inception to August 28, 2022 and used the Cochrane Systematic Assessment Manual Risk of Bias Assessment Tool (version 5.1) and modified Jadad scale to assess risk of bias. The systematic review was conducted via Revman5.4.ResultsNine RCTs with a total of 9818 patients were included. The overall safety profile of tirzepatide is similar to GLP-1RAs, except for the hypoglycemia (tirzepatide 15mg, pooled RR=3.83, 95% CI [1.19- 12.30], P=0.02) and discontinuation (tirzepatide 10mg, pooled RR=1.75,95%CI[1.16-2.63], P=0.007 and 15mg, pooled RR=2.03, 95%CI [1.37-3.01], P=0.0004). It also showed that the dose escalation could not rise the occurrence rates of total, severe, gastrointestinal adverse events and hypoglycemia (P>0.05); Compared with 5mg, tirzepatide 10mg and 15mg were associated with more frequent nausea (P<0.001), discontinuation (P<0.05) and injection-site reaction (P<0.01); The rates of vomiting and diarrhea were dose-dependence at the range of 5-15mg.ConclusionThe safety profile of tirzepatide is generally acceptable, similar to GLP-1 RAs. It is necessary to pay attention to its specific adverse events (hypoglycemia and discontinuation) at high doses (10mg or higher). Nausea, vomiting, diarrhea, discontinuation and injection-site reaction were dose-dependence among specific dose ranges.As the heterogeneity in different studies by interventions, the results may be with biases and the further confirmation is needed. Meanwhile, more well-designed trials are needed to control the confounding factors and ensure adequate sample size

Progress in Construction and Food Application of Chitosan-based Nutrient Delivery System

Chitosan is a naturally-occurring alkaline polysaccharide with excellent biocompatibility, biodegradability, low toxicity, and easy preparation. It has been widely used in the construction of delivery systems for various nutrients and bioactive substances. The chitosan-based nutrient delivery systems are mainly constructed by cross-linking, drying, layer-by-layer self-assembly, coalescence, covalent grafting, microfluidics and biosynthesis. Chitosan can be combined with carbohydrates, proteins and liposomes to form a composite carrier that can obtain more excellent performance and broaden its application in food packaging materials, slow release of bioactive substances and probiotic embedding. In addition, this paper further analyzes the obstacles and limitations of the actual application of chitosan-based nutrient delivery systems in the food industry, to provide important references for the application of chitosan-based delivery carriers in imparting new functional properties to foods, developing new food ingredients, and nutrient fortification

Integrative analysis of non-targeted metabolome and transcriptome reveals the mechanism of volatile formation in pepper fruit

Introduction: Aroma is a key inherent quality attributes of pepper fruit, yet the underlying mechanisms of aroma compound biosynthesis remain unclear.Methods: In this study, the volatile profile of the QH (cultivated Capsicum chinense) and WH (cultivated Capsicum annuum) pepper varieties were putatively identified during fruit development using gas chromatography-mass spectrometry (GC-MS).Results and discussion: The results identified 203 volatiles in pepper, and most of the esters, terpenes, aldehydes and alcohols were significantly down-regulated with fruit ripening. The comparison of volatile components between varieties revealed that aldehydes and alcohols were highly expressed in the WH fruit, while esters and terpenes with fruity or floral aroma were generally highly accumulated in the QH fruit, providing QH with a fruity odor. Transcriptome analysis demonstrated the close relationship between the synthesis of volatiles and the fatty acid and terpene metabolic pathways, and the high expression of the ADH, AAT and TPS genes was key in determining the accumulation of volatiles in pepper fruit. Furthermore, integrative metabolome and transcriptome analysis revealed that 208 differentially expressed genes were highly correlated with 114 volatiles, and the transcription factors of bHLH, MYB, ARF and IAA were identified as fundamental for the regulation of volatile synthesis in pepper fruit. Our results extend the understanding of the synthesis and accumulation of volatiles in pepper fruit

TRABAJOS DE MÉTODO ARQUEOLÓGICO [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201