Potential mechanisms and effects of ultrasound treatment combined with pre- and post-addition of κ-carrageenan on the gelling properties and rheological behavior of myofibrillar proteins under low-salt condition.

This study investigated the effect of ultrasound (US) combined with pre- and post-addition of κ-carrageenan (KC) on the gelling properties, structural characteristics and rheological behavior of myofibrillar proteins (MP) under low-salt conditions. The results showed that US combined with either pre- or post-addition of KC rendered higher gel strength and water holding capacity (WHC) of MP gels than those treated with US alone and added with KC alone (P < 0.05). US combined with pre-addition of KC facilitated the binding between MP and KC, which enhanced the gel strength and WHC of the mixed MP gels and significantly improved the rheological behavior of MP. This was also confirmed by the highest surface hydrophobicity, disulfide bonds and ß-sheet content of the MP gels with US combined with pre-addition of KC. Moreover, microstructural results reflected a denser structure for the pre-addition of KC in combination with US. However, US combined with post-addition of KC resulted in limited MP unfolding and relatively weak hydrophobic interactions in the composite gels, which were less effective in improving the gel properties of the MP gels. This study provides potential strategies for enhancing the gelling properties of low-salt meat products via application of US and KC.

MsSPL12 is a positive regulator in alfalfa (Medicago sativa L.) salt tolerance.

KEY MESSAGE: Over expression of MsSPL12 improved alfalfa salt tolerance by reducing Na+ accumulation and increasing antioxidant enzyme activity and regulating down-stream gene expression. Improvement of salt tolerance is one of the major goals in alfalfa breeding. Here, we demonstrated that MsSPL12, an alfalfa transcription factor gene highly expressed in the stem cells, plays a positive role in alfalfa salt tolerance. MsSPL12 is localized in the nucleus and shows transcriptional activity in the presence of its C-terminus. To investigate MsSPL12 function in plant response to salt stress, we generated transgenic plants overexpressing either MsSPL12 or a chimeric MsSPL12-SRDX gene that represses the function of MsSPL12 by using the Chimeric REpressor gene-Silencing Technology (CRES-T), and observed that overexpression of MsSPL12 increased the salt tolerance of alfalfa transgenic plants associated with an increase in K+/Na+ ratio and relative water content (RWC) under salt stress treatment, but a reduction in electrolyte leakage (EL), reactive oxygen species (ROS), malondialdehyde (MDA), and proline (Pro) compared to wild type (WT) plants. However, transgenic plants overexpressing MsSPL12-SRDX showed an inhibited plant growth and a reduced salt tolerance. RNA-sequencing and quantitative real-time PCR analyses revealed that MsSPL12 affected the expression of plant abiotic resistance-related genes in multiple physiological pathways. The potential MsSPL12-mediated regulatory pathways based on the differentially expressed genes between the MsSPL12 overexpression transgenics and WT controls were predicted. In summary, our study proves that MsSPL12 is a positive regulator in alfalfa salt tolerance and can be used as a new candidate for manipulation to develop forage crops with enhanced salt tolerance.

Elucidating the mechanisms of ultrasound treatment combined with κ-carrageenan addition enhancing the gelling properties of heat-induced myofibrillar protein gel.

This work investigated the effect of ultrasound (US) treatment synergized with κ-carrageenan (KC) on the gel properties, structural characteristics and microstructures of myofibrillar protein (MP) gel. The results demonstrated that simply adding KC enhanced the gel strength and water holding capacity (WHC) of MP gels. Moreover, the gel strength and WHC of MP gels were increased by 56.67 % and 76.19 % via 20 min US treatment synergized with KC, which was mainly attributed to the changes in sulfhydryl content, surface hydrophobicity, and fluorescence intensity of MP gels. Based on the results of molecular docking and secondary structure, it can be hypothesized that the synergistic effect resulted in the rearrangement of the proteins, which altered the interaction site between MP gels and KC, accompanied by stronger binding. Furthermore, the microstructural results indicated that moderate US treatment (20 min) facilitated the production of a more compact and denser MP gels matrix with uniformly sized and distributed pores. However, excessive US treatment (40 and 50 min) caused the MP gels to form looser and disordered gel structure, which reduced the gel strength and WHC. This study suggested that combining of US and KC was a potential tactic to enhance the gelling properties of heat-induced MP gels.

Combined effect of ultrasound treatment and κ-carrageenan addition on the enhancement of gelling properties and rheological behavior of myofibrillar protein: An underlying mechanisms study.

This work aimed to investigate the combined effect of ultrasound (US) treatment and κ-carrageenan (KC) addition on the gelling properties and rheological behaviors of myofibrillar protein (MP). Without US treatment, the KC incorporation promoted the gel strength and water-holding capacity (WHC) of MP gels. These properties were further improved by 20 min US treatment with gel strength of 98.61 g and WHC of 79.87 %, which was mainly attributed to changes associated with hydrophobic interactions and disulfide bonds and the transformation from α-helix to ß-sheet in MP gels. In addition, US treatment for 20 min effectively resulted in a more homogeneous polymer distribution of the MP-KC mixed system, leading to lower particle size and the largest G' and G″ values of the MP-KC mixed gels. However, longer US treatment times (30, 40 and 50 min) rendered lower gel strength, WHC, storage modulus and loss modulus of MP-KC mixed gels, which was mainly due to the formation of loose and disordered gel structures. Our present results indicated that the application of US to MP for an intermediate treatment time (20 min) combined with KC provides a potential and novel strategy to promote the gel qualities of heat-induced MP gels.

The effects of ultrasound-guided QLB and TAPB combined with opioid-free anesthesia (OFA) on clinical efficacy of the patients undergoing abdominal surgery.

Background: Although opioids provide effective analgesia for abdominal surgery, they also present serious unwanted side effects. Ultrasound-guild quadratus lumborum block (QLB) and transversus abdominis plane block (TAPB) have been proven to offer long-lasting and efficient analgesia during abdominal surgery. However, the clinical efficacy of ultrasound-guided QLB and TAPB combined with opioid-free anesthesia (OFA) in abdominal surgery remains unclear. Objective: This study aimed to investigate the impact of ultrasound-guided QLB and TAPB combined with opioid-free anesthesia (OFA) on the clinical efficacy of abdominal surgery. Methods: A total of 122 patients scheduled for abdominal surgery at People's Hospital of Wanning between March 2021 and April 2022 were enrolled in this study. Participants were randomly divided into two groups: the experimental group (QLB/TAPB + OFA, 62 patients) and the control group (opioid anesthesia, 60 patients). The clinical efficacy of the QLB/TAPB combined with OFA technique was evaluated by analyzing patients' vital signs, postoperative consciousness recovery time, numeric rating scale (NRS) score, and immune function in both groups. Results: We observed that systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in experimental group were significantly higher than those in control group after induction (p < 0.05). Heart rate (HR) in experimental group was significantly lower than in the control group at intraoperative 1h (p < 0.05). Additionally, bispectral index (BIS), state entropy (SE), and response entropy (RE) levels in the experimental group were significantly higher than those in the control group (p < 0.05). Furthermore, extubation and awakening time were significantly shorter in the experimental group compared to the control group (p < 0.05). The NRS scores in the experimental group were markedly lower than those in the control group. Moreover, IL-6 and CRP levels in the experimental group were obviously lower than in the control group after postoperative 1d (p < 0.05). Interestingly, IL-6 (p < 0.001), CRP (p < 0.001), and PCT (p = 0.037) levels in female patients of the experimental group were all significantly lower than those in the control group after postoperative 1d. Conclusions: Ultrasound-guided QLB and TAPB combined with OFA technique can reduce pain intensity and enhance the patients' immune function in abdominal surgery.

Purification, Immunological Identification, and Characterization of the Novel Silkworm Pupae Allergen Bombyx mori Lipoprotein 3 (Bomb m 6).

Allergic reactions caused by silkworm pupae greatly limit their utilization, and studies suggest that silkworm pupae proteins of 25-30 kDa may be the principal allergens. To further understand these allergens, we attempted to purify a protein of about 30 kDa by ammonium sulfate salting, pH-graded precipitation, and ion-exchange chromatography. The protein was identified by mass spectrometry and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), western blot, enzyme-linked immunosorbent assays, circular dichroism, and fluorescence spectroscopy analyses. We identified the purified protein as Bombyx mori lipoprotein 3 (Bmlp3), which has high IgE reactivity and is a novel uncharacterized allergen that we named Bomb m 6 according to the WHO/IUIS Allergen Nomenclature Sub-Committee. This allergen is stable against heat, acids, bases, and digestion. In conclusion, we successfully purified and characterized a novel silkworm pupa allergen, which may inform the diagnosis and treatment of silkworm pupa allergies.

The Effects of Ethanol and Rutin on the Structure and Gel Properties of Whey Protein Isolate and Related Mechanisms.

The effects of different levels of rutin (0, 0.05%, 0.1%, 0.2% and 0.3% w/v) and ethanol on the structure and gel properties of whey protein isolate (WPI) were examined. The results showed that the addition of ethanol promoted the gel formation of WPI. The addition of rutin increased the gel strength of WPI and maintained the water-holding capacity of the gel. Ethanol caused an increase in thiol content and surface hydrophobicity, but rutin decreased the thiol content and surface hydrophobicity of WPI. The particle size, viscosity and viscoelasticity of WPI increased at rutin levels of 0.2% and 0.3%, indicating that rutin caused cross-linking and aggregation of WPI, but rutin had no significant effect on the zeta-potential, indicating that electrostatic interactions were not the main force causing the changes in protein conformation and gel properties. Ethanol and rutin improved the gel properties of WPI possibly by inducing cross-linking of WPIs via hydrophobic and covalent interactions.

Improved effect of flaxseed gum on the weakened gelling properties of myofibrillar protein induced by catechin.

The effect of flaxseed gum (FG) on the weakened gelling properties of myofibrillar proteins (MP) induced by catechin was investigated. Different levels of FG and catechin were incorporated into MP and the chemical changes of MP were studied; MP emulsions and gels with different levels of FG and catechin were prepared and their properties were studied. Catechin promoted the loss of thiol and the exposure of the hydrophobic groups of MP and increased the particle size and apparent viscosity of emulsions, resulting in a poor gel network. The incorporation of FG enhanced the gel strength, water holding capacity and dynamic rheological properties, which might be attributed to the formation of uniform and stabilized emulsions with high apparent viscosity and the enhanced disulfide cross-linking and hydrophobic interactions during heat-induced gelation. FG could be a potential approach in overcoming the deterioration of protein gels caused by catechin.

The beneficial effects of rutin on myofibrillar protein gel properties and related changes in protein conformation.

Effects of different levels of rutin (0, 10, 50, 100 and 200 µmol/g protein) on the conformational changes and gel properties of myofibrillar protein (MP) were investigated. Rutin at 200 µmol/g caused the greatest carbonyl content. The incorporation of rutin caused the losses of thiol, free amine and α-helix contents, reduction in tryptophan intrinsic fluorescence intensity, and enhanced exposure of hydrophobic groups and protein cross-linking. When compared with control, the MP gels with 10, 50 and 100 µmol/g rutin had higher gel strength but slight lower water-holding capacity; the gels appeared to have compact microstructure with few visible pores. However, 200 µmol/g rutin was detrimental to gel properties. All the gels with rutin presented higher final storage modulus and converted to elasticity-dominant gel types. The results indicate that a slightly high concentration of rutin could improve MP gel properties which are related to the protein conformational changes induced by rutin.

Preparation and characterization of acrylic bone cement with high drug release.

Drug-loaded bone cement is used as an application method to prevent and treat prosthesis-related infection. Despite the commercial availability of drug-loaded bone cement, low release rate of drugs from drug-loaded bone cement may result in the emergence of drug-resistant coagulase-negative staphylococci in subsequent deep infection. This work presents a method to control and increase both the drug release rate and total release amounts of drugs for drug-loaded bone cement without losing the mechanical properties of cement. A novel drug-loaded bone cement is also developed by introducing cross-linked poly(methylmethacrylate-acrylic acid sodium salt) particles into bone cement. Capable of increasing the hydrophilicity of the cement and allowing fluids to pass into the cement, the bone cement developed here supplements both the drug release rate and total release amounts of drugs.