Transformation of cell wall pectin profile during postharvest ripening process alters drying behavior and regulates the sugar content of dried plums.

This study evaluated the effects of postharvest ripening (0-6 days, D0-6) on cell wall pectin profile, infrared-assisted hot air-drying characteristics, and sugar content. Results showed that during postharvest ripening progress, the content of water-soluble pectin (WSP) and chelate-soluble pectin (CSP) increased while the content of Na2CO3-soluble pectin (NSP) and hemicellulose (HC) decreased. In addition, the average molecular weight of WSP increased while the average molecular weight of NSP decreased. Secondly, the drying time of plums with different postharvest ripening periods was in the order: D3 < D4 < D2 < D1 < D0 < D5 < D6. Furthermore, the sugar content of dried plums was mainly influenced by drying time, with three stages of sugar changes observed, tied to moisture content: (1) Sucrose hydrolyzes (50-85%); (2) Fructose and glucose degrade (15-50%); (3) Sorbitol degrades (15-42%). These findings indicate that the transformation of cell wall pectin profile during the postharvest ripening process alters drying behavior and regulates the sugar content of dried plums. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Galacturonic acid (PubChem CID: 439215); Acetone (PubChem CID: 180); Distilled water (PubChem CID: 962); Trans-1,2-Diaminocyclohexane-N, N, N, N'-tetraacetic acid (PubChem CID: 2723845); Na2CO3 (PubChem CID: 10340); Glucose (PubChem CID: 5793); fructose (PubChem CID: 2723872) sucrose (PubChem CID: 5988) sorbitol (PubChem CID: 5780) and Sodium borohydride (PubChem CID: 4311764).

Effect of the ripening stage on the pulsed vacuum drying behavior of goji berry (Lycium barbarum L.): Ultrastructure, drying characteristics, and browning mechanism.

In current work, the effect of ripening stages (I, II, and III) on pulsed vacuum drying (PVD) behavior of goji berry was explored. The shortest drying time of goji berry was observed at stage I (6.99 h) which was 13.95 %, and 28.85 % shorter than those at stages II, and III, respectively. This phenomenon was closely associated with the ripening stage, as contributed by the initial physiochemical differences, ultrastructure alterations, and moisture distribution. In addition, lower maturity suffered more severe browning, primarily due to the enzymatic and non-enzymatic reactions of phenolics, followed by pigment degradation and the Maillard reaction. Additionally, the PVD process promoted the rupture and transformation of the pectin fractions, also causing browning either directly or indirectly through participation in other chemical reactions. These findings suggest that the appropriate ripening stage of goji berry should be considered as having a significant impact on drying behaviors and quality attributes.

Vacuum-steam pulsed blanching: An emerging method to enhance texture softening, drying behavior and physicochemical properties of Cornus officinalis.

Vacuum steam pulsed blanching (VSPB) was employed as a novel blanching technology on Cornus officinalis to soften the tissue for subsequent coring and dehydration. The current work aims to explore its effect on mass transfer behavior, PPO inactivation, drying characteristics, physicochemical properties, antioxidant capacity, and microstructure of C. officinalis. Results showed that VSPB increased water loss, decreased solid gain, and increased weight reduction with increased blanching cycles. Besides, VSPB significantly changed physical properties and extensively reduced drying time which was attributed to the cell wall components dissolving and cell turgor pressure decreasing, also verified by observing microstructure alteration. PPO was completely denatured after blanching in 6 cycles, but phenolic compounds were still diffused or degraded. Notably, the content of flavonoids and antioxidant capacity significantly increased compared to fresh samples probably due to increased extractability caused by the disrupting cell structure. Besides, the carotenoids and ascorbic acid could be well preserved.

Peeling mechanism of tomato induced by HHAIB: Microscopic, ultrastructure, chemical, physical and mechanical properties perspectives.

In order to better manage the peeling degree and avoid unnecessary losses, the current work aimed to explore the peeling mechanism of a novel peeling technology, high-humidity hot air impingement blanching (HHAIB). The relationships between HHAIB peeling performance and the changes in skin temperature, skin structure, water state, pectin fractions content, and skin mechanical properties of tomatoes were analyzed. Results showed, after HHAIB treatment, the epicuticular wax was disrupted, the skin exhibited more and longer random cracks, the degradation of inner skin tissue was observed by transmission electron microscopy, the free water percentage increased resulting in water loss in the whole tomato, the water-soluble pectin contents decreased in tomato fleshes, while the contents of chelate-soluble pectin and sodium-carbonate-soluble pectin increased. HHAIB heating reduced the elongation at break, and increased Young's Modulus of tomato peel. This study revealed the HHAIB peeling mechanism and provided new insights for developing HHAIB peeling technology.

Real-Time Identification of Time-Varying Cable Force Using an Improved Adaptive Extended Kalman Filter.

The real-time identification of time-varying cable force is critical for accurately evaluating the fatigue damage of cables and assessing the safety condition of bridges. In the context of unknown wind excitations and only one available accelerometer, this paper proposes a novel cable force identification method based on an improved adaptive extended Kalman filter (IAEKF). Firstly, the governing equation of the stay cable motion, which includes the cable force variation coefficient, is expressed in the modal domain. It is transformed into a state equation by defining an augmented Kalman state vector with the cable force variation coefficient concerned. The cable force variation coefficient is then recursively estimated and closely tracked in real time by the proposed IAEKF. The contribution of this paper is that an updated fading-factor matrix is considered in the IAEKF, and the adaptive noise error covariance matrices are determined via an optimization procedure rather than by experience. The effectiveness of the proposed method is demonstrated by the numerical model of a real-world cable-supported bridge and an experimental scaled steel stay cable. Results indicate that the proposed method can identify the time-varying cable force in real time when the cable acceleration of only one measurement point is available.

A programmable high-expression yeast platform responsive to user-defined signals.

Rapidly growing yeasts with appropriate posttranslational modifications are favored hosts for protein production in the biopharmaceutical industry. However, limited production capacity and intricate transcription regulation restrict their application and adaptability. Here, we describe a programmable high-expression yeast platform, SynPic-X, which responds to defined signals and is broadly applicable. We demonstrated that a synthetic improved transcriptional signal amplification device (iTSAD) with a bacterial-yeast transactivator and bacterial-yeast promoter markedly increased expression capacity in Pichia pastoris. CRISPR activation and interference devices were designed to strictly regulate iTSAD in response to defined signals. Engineered switches were then constructed to exemplify the response of SynPic-X to exogenous signals. Expression of α-amylase by SynPic-R, a specific SynPic-X, in a bioreactor proved a methanol-free high-production process of recombinant protein. Our SynPic-X platform provides opportunities for protein production in customizable yeast hosts with high expression and regulatory flexibility.

A Synthetic Malonyl-CoA Metabolic Oscillator in Komagataella phaffii.

Malonyl-CoA is a key metabolic molecule that participates in a diverse range of physiological responses and can act as a building block for a variety of value-added pharmaceuticals and chemicals. The cytosolic malonyl-CoA concentration is usually very low, and thus dynamic metabolic control of malonyl-CoA variation will aid its stable formation and efficient consumption. We developed a synthetic malonyl-CoA metabolic oscillator in yeast. A synthetic regulatory protein, Prm1-FapR, was constructed by fusing a yeast transcriptional activator, Prm1, with a bacterial malonyl-CoA-sensitive transcription repressor, FapR. Two oppositely regulated biosensors were then engineered. A total of 18 hybrid promoter variants were designed, each carrying the operator sequence (fapO) of FapR and the core promoter of PAOX1 (cPAOX1), which is naturally regulated by Prm1. The promoter activities of these variants, regulated by Prm1-FapR, were tested. Through this process, a sensor for Prm1-FapR/(-52)fapO-PAOX1 carrying an activation/deactivation regulation module was built. Meanwhile, 24 promoter variants of PGAP with fapO inserted were designed and tested using the fusion regulator, giving a sensor for Prm1-FapR/PGAP-(+22) fapO that contained a repression/derepression regulation module. Both sensors were subsequently integrated into a single cell, which exhibited correct metabolic switching of eGFP and mCherry reporters following manipulation of cytosolic malonyl-CoA levels. The Prm1-FapR/(-52)fapO-PAOX1 and the Prm1-FapR/PGAP-(+22)fapO were also used to control the malonyl-CoA source and sink pathways, respectively, for the synthesis of 6-methylsalicylic acid. This finally led to an oscillatory metabolic mode of cytosolic malonyl-CoA. Such a metabolator is useful in exploring potential industrial and biomedical applications not limited by natural cellular behavior.

Engineered ethanol-driven biosynthetic system for improving production of acetyl-CoA derived drugs in Crabtree-negative yeast.

Many natural drugs use acetyl-CoA as the key biosynthetic precursor. While in eukaryotic chassis host like yeast, efficient biosynthesis of these drugs is often hampered by insufficient acetyl-CoA supply because of its compartmentalized metabolism. Reported acetyl-CoA engineering commonly modifies central carbon metabolism to pull and push acetyl-CoA into cytosol from sugars or redirects biosynthetic pathways in organelles, involving complicated metabolic engineering strategies. We constructed a new biosynthetic system based on a Crabtree-negative yeast, which grew exceptionally on ethanol and assimilated ethanol directly in cytosol to acetyl-CoA (3 steps). A glucose-repressed and ethanol-induced transcriptional signal amplification device (ESAD) with 20-fold signal increase was constructed by rewiring native transcriptional regulation circuits. This made ethanol the sole and fast-growing substrate, acetyl-CoA precursor, and strong biosynthetic pathway inducer simultaneously. The ESAD was used for biosynthesis of a commercial hypolipidemic drug intermediate, monacolin J. A strain producing dihydromonacolin L was firstly constructed and systematically engineered. We further developed a coculture system equipped with this upstream strain and a downstream strain with dihydromonacolin L-to-monacolin J module controlled by a synthetic constitutive transcriptional signal amplification device (CSAD). It produced a high monacolin J titre of 2.2 g/L on ethanol in bioreactor. Engineering glucose-supported and ethanol-repressed fatty acids biosynthesis in the upstream strain contributed more acetyl-CoA for monacolin J and improved its titre to 3.2 g/L, far surpassing other reported productions in yeasts. This study provides a new paradigm for facilitating the high-yield production of acetyl-CoA derived pharmaceuticals and value-added molecules.

MiR-31 and miR-143 affect steroid hormone synthesis and inhibit cell apoptosis in bovine granulosa cells through FSHR.

The regulatory role of microRNAs (miRNAs) has been explored in ovarian cells, and the effects of miRNAs on gonadal development, apoptosis, ovulation, and steroid production have been reported. In this study, we analyzed the effects of follicle stimulating hormone (FSH) on miR-31 and miR-143 expression levels in bovine granulosa cells (GCs). Our results demonstrated that the FSH receptor (FSHR) is a common target gene of miR-31 and miR-143 in bovine GCs. We further analyzed the roles of miR-31 and miR-143 in bovine GCs by transfecting miR-31 and miR-143 mimics and inhibitors. The Western blot and RT-PCR results showed that miR-31 and miR-143 reduced the mRNA and protein expression levels of FSHR. Moreover, miR-31 overexpression decreased the secretion of progesterone (P4), and miR-143 overexpression decreased both the synthesis of P4 and the secretion of estrogen (E2). In contrast, miR-31 inhibition increased the secretion of progesterone (P4), and miR-143 inhibition increased both the synthesis of P4 and the secretion of E2. Finally, we analyzed the possible effects of miR-31 and miR-143 on bovine GC apoptosis. The results showed that transfection with miR-31 and miR-143 mimics promoted GC apoptosis and that miR-143 and miR-31 inhibition reduced the rate of apoptosis in bovine GCs. Taken together, our results indicate that miR-31 and miR-143 decrease steroid hormone synthesis and inhibit bovine GC apoptosis by targeting FSHR.

miR-181a regulate porcine preadipocyte differentiation by targeting TGFBR1.

miRNAs have been shown to regulate a variety of biological process. It has been shown that miR-181a regulates porcine adipogenesis by targeting Tumor Necrosis Factor-α (TNF-α), but the overall functions of miR-181a in porcine preadipocyte differentiation remain unclear. This study aimed to explore the functions of miR-181a in porcine preadipocyte differentiation via the TGFß/Smad pathway. The TargetScan program was used to predict miRNAs targeting TGFBR1, and miR-181a was selected as a candidate. To investigate the functions of miR-181a, miRNA mimics and inhibitors were used to overexpress or knockdown miR-181a, respectively. RT-qPCR and Western blotting were used to measure the expression of aP2, PPARγ, C/EBPα and TGFBR1 in porcine preadipocytes. Lipid accumulation and adipocyte apoptosis were detected using Oil Red O staining and flow cytometry, respectively. Taken together, our results indicated that miR-181a promoted porcine preadipocyte differentiation by directly targeting TGFBR1.

MiR-29b affects the secretion of PROG and promotes the proliferation of bovine corpus luteum cells.

The regulatory role of miRNAs has been explored in ovarian cells, and their effects on gonadal development, apoptosis, ovulation, steroid production and corpus luteum (CL) development have been revealed. In this study, we analyzed the expression of miR-29b at different stages of bovine CL development and predicted the target genes of miR-29b. We confirmed that miR-29b reduces the expression of the oxytocin receptor (OXTR), affects progesterone (PROG) secretion and regulates the function of the CL. RT-PCR showed that the expression of miR-29b was significantly higher in functional CL phases than in the regressed CL phase. Immunohistochemistry showed that OXTR was expressed in both large and small CL cells and was mainly located in the cell membrane and cytoplasm of these cells. We analyzed the expression levels of OXTR and found that transfection with a miR-29b mimic decreased OXTR expression, but transfection with the inhibitor had a limited effect on the expression of the OXTR protein. At the same time, the secretion of PROG was significantly increased in the miR-29b mimic-transfected group. We also analyzed the effect of miR-29b on the apoptosis of CL cells. Finally, we found that miR-29b could promote the proliferation of bovine CL cells. In conclusion, we found that miR-29b reduces the expression of OXTR and can promote PROG secretion and the proliferation of CL cells via OXTR.

Effects of MiR-375-BMPR2 as a Key Factor Downstream of BMP15/GDF9 on the Smad1/5/8 and Smad2/3 Signaling Pathways.

BACKGROUND/AIMS: Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), which are secreted by oocytes, are important regulators of follicular growth and development and ovarian function. These two factors can regulate the proliferation and apoptosis of cumulus cells via modulation of the Smad signaling pathway. Studies have shown that BMP15 and GDF9 can affect the level of miR-375, whereas the target gene of miR-375 is BMPR2, the type II receptor of BMP15 and GDF9. However, whether or how the BMP15/ GDF9-miR-375-BMPR2 pathway affects the proliferation and apoptosis of bovine cumulus cells through regulation of the Smad signaling pathway remains unclear. METHODS: In this study, cumulus cells were first obtained from cumulus-oocyte complexes (COCs). Appropriate concentrations of BMP15 and GDF9 were added during the in vitro culture process. Cell Counting Kit-8 (CCK-8) analyses and flow cytometry were used to determine the effects of BMP15/GDF9 on bovine cumulus cells proliferation and apoptosis. Subsequently, miR-375 mimics, miR-375 inhibitor and BMPR2 siRNA were synthesized and used for transfection experiments. Western Blot analysis was used to detect changes before and after transfection in the expression levels of the BMP15/GDF9 type I receptors ALK4, ALK5 and ALK6; the phosphorylation levels of Smad2/3 and Smad1/5/8, which are key signaling pathway proteins downstream of BMP15/GDF9; the expression levels of PTX3, HAS2 and PTGS2, which are key genes involved in cumulus cells proliferation; and Bcl2/Bax, which are genes involved in apoptosis. RESULTS: The addition of 100 ng/mL BMP15 or 200 ng/mL GDF9 or the combined addition of 50 ng/mL BMP15 and 100 ng/mL GDF9 effectively inhibited bovine cumulus cell apoptosis and promoted cell proliferation. BMP15/GDF9 negatively regulated miR-375 expression and positively regulated BMPR2 expression. High levels of miR-375 and inhibition of BMPR2 resulted in increased expression of ALK4 and decreased expression of PTX3, HAS2 and PTGS2, whereas miR-375 inhibition resulted in the opposite results. BMP15 and GDF9 significantly activated the levels of p-Smad2/3 and p-Smad1/5/8, whereas miR-375 inhibited the levels of p-Smad2/3 and p-Smad1/5/8 by negatively regulating BMPR2 and also led to apoptosis. CONCLUSION: BMP15 and GDF9 have synergistic effects and can act through miR-375 to affect the expression levels of type I receptor ALK4 and type II receptor BMPR2 and the activation of Smad signaling pathway, which subsequently affected the proliferation, spread and apoptosis of cumulus cells.

Roles of differential expression of microRNA-21-3p and microRNA-433 in FSH regulation in rat anterior pituitary cells.

Follicle-stimulating hormone (FSH) secreted by adenohypophyseal cells plays an important role in the regulation of reproduction, but whether microRNAs (miRNAs) regulate the secretion of FSH remains unclear. In the present study, we predicted and screened miRNAs that might act on the follicle-stimulating hormone beta-subunit (FSHb) gene of rats using the TargetScan program and luciferase reporter assays, and the results identified two miRNAs, miR-21-3p and miR-433. We then transfected these miRNAs into rat anterior adenohypophyseal cells and assessed the FSHb expression levels in and FSH secretion by the transfected cells through quantitative PCR and ELISA. The results showed that both miR-21-3p and miR-433 down-regulated the expression levels of FSHb and resulted in the decrease of the secretion of FSH compared with the control group, and treatment with miR-21-3p and miR-433 inhibitors up-regulated the expression levels of FSHb and resulted in the increase of the secretion of FSH. Taken together, our results indicate that miR-21-3p and miR-433 can down-regulate the expression of FSHb by directly targeting the FSHb 3'UTR in rat primary pituitary cells. Our findings provide evidence that miRNAs can regulate FSHb expression and further affect the secretion of FSH and might contribute to the use of miRNAs for the regulation of animal reproduction.

Regulatory Role of miRNA-375 in Expression of BMP15/GDF9 Receptors and its Effect on Proliferation and Apoptosis of Bovine Cumulus Cells.

BACKGROUND: Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are members of the transforming growth factor beta (TGF-ß) superfamily. Through autocrine and paracrine mechanisms, these two factors can regulate cell differentiation, proliferation, and other functions in the ovary locally. Furthermore, GDF9 and BMP15 play vital roles in follicular growth, atresia, ovulation, fertilization, reproduction, and maintenance. Numerous studies have demonstrated a synergy between BMP15 and GDF9. Studies in humans and mice have indicated that the synergy between BMP15 and GDF9 is primarily mediated by the bone morphogenetic protein type II receptor (BMPR2). The BMP15/GDF9 heterodimer needs to bind to the BMPR2-ALK4/5/7-ALK6 receptor complex to activate the SMAD2/3 signaling pathway. However, it is not clear which genes mediate and regulate the effects of the BMP15/GDF9 proteins on bovine cumulus cells (CCs). METHODS: Our earlier study showed that BMPR2 is a gene that is directly targeted and regulated by miR-375. Therefore, we designed and synthesized an miR-375 mimics/inhibitor and regulated BMPR2 expression in bovine CCs by the overexpression or inhibition of miR-375. After the overexpression or inhibition of miR-375, the apoptosis rate of bovine CCs was measured by flow cytometry; changes in critical gene expression were measured by RT-qPCR and western blot assays; and the proliferation of bovine CCs was measured by CCK-8 assay. RESULTS: In bovine CCs, the overexpression of miR-375 resulted in decreased BMPR2 and ALK7 expression, whereas the inhibition of miR-375 caused increased BMPR2 and ALK7 expression. The overexpression of miR-375 attenuated the proliferation ability and significantly increased the apoptosis rate of bovine CCs, whereas the inhibition of miR-375 did not significantly change the proliferation ability or apoptosis rate. CONCLUSIONS: BMPR2, a target of miR-375, is regulated by this molecule, thereby affecting expression of BMP15/GDF9 receptors, and the proliferation and apoptosis of bovine CCs.

Preparation and antibacterial activities of hollow silica-Ag spheres.

Hollow silica spheres with round mesoporous shells were synthesized by core-shell template method, using monodispersed cationic polystyrene particles as core, and TEOS (tetraethoxysilane) as the silica source to form shell. After calcination at 550°C, uniform spheres with a thin shell of silica and hollow interior structures. Transmission electron microscopy results showed that the size of the spheres is about 700 nm in diameter with narrow distribution. In addition, the spheres have a high surface area of 183 m(2)/g. The spheres were subsequently used as silver-loading substrates and the silver loaded spheres were tested in antimicrobial study against gram negative bacteria Eschrichia coli in vitro. The hollow silica-Ag spheres proved significantly higher antibacterial efficacy against E. coli as compared to that of the common silica-Ag particles.

Ag-CuFe2O4 magnetic hollow fibers for recyclable antibacterial materials.

Copper ferrite (CuFe2O4) magnetic hollow fibers were prepared by applying an organic sol-thermal decomposition method, and silver nanoparticles were subsequently loaded on the fibers by calcination. The Ag-CuFe2O4 fibers exhibited excellent antibacterial efficacy against four different bacteria (E. coli, S. typhi, S. aureus and V. parahaemolyticus) with consistent results. Typical ferromagnetism behavior exhibited from the Ag-CuFe2O4 fibers enables their feasible recyclability.

[Experimental study on pharmacodynamical of Oxalis griffithii, a national medicine in Guizhou].

OBJECTIVE: To study the on effects of anti-bacteria, anti-inflammatory and pyretolysis of Oxalis griffithii, it is possible safety. METHOD: The mice model was established by xylene (auricle smear method) and carrageenin (injection under the aponeuroses) respectively, rat febrile model was builded by 2,4-dintrophenol injection, and observe the effects of anti-bacteria in vitro that contracted by Staph aureus, Escherichia, Shigella, Pseudomonas, Aeruginosa. The mice model of experiment study on urgent poison effects (injection under the aponeuroses). RESULT: It was found that the mouse ear edema induced by xylene, the increased vascular permeability caused by xylene were all significantly suppressed by Oxalis griffithii. At the same time, it could depressed the rat fervescence by 2,4-dinitrophenol. In addition, it has effect on fighting against Escherichia coli in cavum abdominis of mice. Oxalis griffithii hasn't canker affect. CONCLUSION: These results suggested that Oxalis griffithii had the effects of antinflammatory, pyretolysis, and safety.