Improvement of gelation properties of Penaeus vannamei surimi by magnetic field-assisted freezing in combination with curdlan.

Traditional methods of freezing and thawing may harm the quality of meat products. In order to reduce the negative impact of freezing on surimi products, the magnetic field-assisted freezing method is combined with various curdlan ratios to enhance the gelation characteristics of Penaeus vannamei surimi in this study. The results showed that the magnetic field-assisted freezing technique significantly improved the quality of thawed surimi compared with soaking freezing (SF), whereas the addition of curdlan further improved the gelation properties, and the gel strength, water-holding capacity, textural properties, whiteness, and G' value were significantly improved when its content was increased to 0.6 %. However, excessive amounts of curdlan interfered with protein covalent cross-linking, leading to a decrease in gel quality. Additionally, the addition of magnetic field and curdlan encouraged the shift of the α-helix to the random coil and ß-sheet transition, which stimulated the growth of myofibril molecules, exposed the hydrophobic groups and thiols, improved protein-molecule interactions, and promoted systematic gathering of proteins, leading to the formation of the microstructure of dense and small pores. It also resulted in a drop in water release, an increase in the proton density and a shift in the water condition from free water to more immobile water, which had higher sensory qualities. These effects together resulted in a reduction in thawing and cooking loss to 11.41 % and 13.83 %, respectively. These results also help to clarify the gelation process of shrimp surimi and help to regulate the gelation characteristics of shrimp surimi products.

Effects of blackberry (Rubus spp.) polysaccharide on the structure and thermal behavior of the myofibrillar protein of chicken breast meat.

Blackberry crude polysaccharides (BCP) was added to chicken breast to inspect the intermolecular interaction with myofibrillar protein (MP). The influence of BCP on the thermal transformation behavior and protein micro-structure during temperature rise period was studied. The results showed that the interaction between BCP and MP was mainly affected by the concentration of BCP and heating temperature. The results of infrared spectrophotometer and nano-particle/zeta potentiometer showed that a BCP-MP complex was generated through hydrogen bond and electrostatic interaction, which could promote the transformation of MP from ß-folding to ß-Angle transformation. The fluorescence spectra showed that the BCP was helped to the spread of protein structure of the MP. Moreover, synchronous thermal analyzer and rheometer results revealed that the BCP increased the enthalpy value and elastic modulus of MP. Scanning electron microscope verified pores inside the BCP-MP complex are more evenly distributed and smaller, which led to the high cross-linking of network and good stability of water distribution for the MP. The addition of BCP enhances the hydrogen bonds and disulfide bonds of MP molecules, which can strengthen the network structure and ultimately improve the performance of meat products.

Effect of cellulose on gel properties of heat-induced low-salt surimi gels: Physicochemical characteristics, water distribution and microstructure.

The processing of surimi products requires the addition of high levels of salt, which makes it a high-salt food that poses a risk to human health. The search for exogenous additives to reduce the salt content of surimi products while ensuring their quality characteristics is crucial. Therefore, the effect of different species of cellulose on enhancing the quality characteristics of low-salt surimi gels was investigated and the best-modified cellulose was identified. Carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), and microcrystalline cellulose (MCC) were selected for this study to compare with high-salt control and low-salt control. The results showed that cellulose could induce conformational transitions of proteins and promote the formation of an ordered and dense surimi gel network and the minimum porosity of 15.935% was obtained in the MCC-treated group. The cellulose-treated group conferred good textural properties to the surimi gels, significantly improved gel strength and water retention capacity (p < 0.05), and reduced the amount of water lost after cooking treatment (p < 0.05). Low-field NMR results showed that cellulose reduced the release of water, converting more free water to immobile water, thus increasing the water proton density. The higher energy storage modulus G' in the presence of cellulose indicated a more stable surimi gel system dominated by springiness. In summary, cellulose could confer better quality characteristics to low-salt surimi gels and MCC performance was superior to other cellulose species. This study helps the understanding of the mechanism of cellulose-surimi action on the development of high-quality low-salt surimi gels.

Effect of к-carrageenan on saltiness perception and texture characteristic related to salt release in low-salt surimi.

The purpose of this study was to investigate the effect of Kappa (к)-carrageenan on texture and perception of saltiness of low salt surimi. The low-field nuclear magnetic resonance (LF-NMR) and microstructure results showed that к-carrageenan could promote the formation of more immobilized water in low salt surimi gel, change its matrix structure, and lead to the uneven spatial distribution of sodium, thus enhancing saltiness perception. The rheological properties of surimi showed that к-carrageenan could increase the network strength of low salt surimi gel and improve its thermostability. Furthermore, the low salt surimi gel added with к-carrageenan has lower cooking loss, higher water holding capacity (WHC), gel strength and improved texture properties. Therefore, к-carrageenan has the effects of improving the quality and increasing salt perception of surimi gel. This study provides a new method for reducing salt consumption in food industry.

Injectable hydrogels derived from marine polysaccharides as cell carriers for large corneal epithelial defects.

Injectable hydrogels have been employed for sutureless repair of corneal epithelial defects, which can perfectly fit the defect sites and minimize the associated discomfort. However, numerous hydrogels are ineffective in treating large corneal epithelial defects and still suffer from poor biocompatibility or weak applicability when used as cell carriers. Herein, hydroxypropyl chitin/carboxymethyl chitosan (HPCT/CMCS) temperature-sensitive hydrogels are fabricated, and their physicochemical properties and suitability for corneal epithelial repair are investigated. The results demonstrate that HPCT/CMCS hydrogels have excellent temperature sensitivity between 20 and 25 °C and a transparency of over 80 %. Besides, HPCT/CMCS hydrogels can promote cell proliferation and facilitate cell migration of primary rabbit corneal epithelial cells (CEpCs). A rabbit large corneal epithelial defect model (6 mm) is established, and CEpCs are transplanted into defect sites by HPCT/CMCS hydrogels. The results suggest that HPCT/CMCS/CEpCs significantly enhance the repair of large corneal epithelial defects with a healing rate of 99.6 % on day 8, while reducing inflammatory responses and scarring formation. Furthermore, HPCT/CMCS/CEpCs can contribute to the reconstruction of damaged tissues and the recovery of functional capacities. Overall, HPCT/CMCS hydrogels may be a feasible corneal cell carrier material and can provide an alternative approach to large corneal epithelial defects.

Ultrasonic treatment combined with curdlan improves the gelation properties of low-salt Nemipterus virgatus surimi.

In this study, the gel properties of ultrasonic alone, curdlan treatment alone, and the combination of both at low-salt surimi levels were investigated, mainly in terms of textural properties, water holding capacity, water distribution, dynamic rheology, protein secondary structure, microstructure and correlation analysis. The results showed that the springiness, gel strength, water holding capacity and energy storage modulus (G') of the low-salt surimi gels without ultrasonic or curdlan treatment were lower than those of the high-salt concentration surimi gels. Compared with the 1 % low-salt group, the ultrasonic treatment combination with curdlan resulted in a significant improvement (p < 0.05) in the texture, water holding capacity and energy storage modulus (G') of the low-salt surimi at the same salt concentration. The gel strength increased significantly from 3386.360 g·mm to 5457.203 g·mm, but there was no significant improvement in whiteness (p > 0.05). In addition, ultrasonic treatment combined with curdlan promoted the shift of the α-helix to the random coil and the ß-turn angle shift, thus exposing the internal groups, enhancing protein intermolecular interactions, and promoting the orderly aggregation of proteins, resulting in a microstructure of dense, and obtained the lowest porosity of 14.534 %. The present study might be necessary for promoting the high-value use of aquatic surimi products and the development of low-salt foods.

Development and validation of multivariable prediction models for adverse COVID-19 outcomes in patients with IBD.

OBJECTIVES: Develop an individualised prognostic risk prediction tool for predicting the probability of adverse COVID-19 outcomes in patients with inflammatory bowel disease (IBD). DESIGN AND SETTING: This study developed and validated prognostic penalised logistic regression models using reports to the international Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease voluntary registry from March to October 2020. Model development was done using a training data set (85% of cases reported 13 March-15 September 2020), and model validation was conducted using a test data set (the remaining 15% of cases plus all cases reported 16 September-20 October 2020). PARTICIPANTS: We included 2709 cases from 59 countries (mean age 41.2 years (SD 18), 50.2% male). All submitted cases after removing duplicates were included. PRIMARY AND SECONDARY OUTCOME MEASURES: COVID-19 related: (1) Hospitalisation+: composite outcome of hospitalisation, ICU admission, mechanical ventilation or death; (2) Intensive Care Unit+ (ICU+): composite outcome of ICU admission, mechanical ventilation or death; (3) Death. We assessed the resulting models' discrimination using the area under the curve of the receiver operator characteristic curves and reported the corresponding 95% CIs. RESULTS: Of the submitted cases, a total of 633 (24%) were hospitalised, 137 (5%) were admitted to the ICU or intubated and 69 (3%) died. 2009 patients comprised the training set and 700 the test set. The models demonstrated excellent discrimination, with a test set area under the curve (95% CI) of 0.79 (0.75 to 0.83) for Hospitalisation+, 0.88 (0.82 to 0.95) for ICU+ and 0.94 (0.89 to 0.99) for Death. Age, comorbidities, corticosteroid use and male gender were associated with a higher risk of death, while the use of biological therapies was associated with a lower risk. CONCLUSIONS: Prognostic models can effectively predict who is at higher risk for COVID-19-related adverse outcomes in a population of patients with IBD. A free online risk calculator (https://covidibd.org/covid-19-risk-calculator/) is available for healthcare providers to facilitate discussion of risks due to COVID-19 with patients with IBD.

Development and validation of multivariable prediction models for adverse COVID-19 outcomes in IBD patients.

IMPORTANCE: Risk calculators can facilitate shared medical decision-making 1 . Demographics, comorbidities, medication use, geographic region, and other factors may increase the risk for COVID-19-related complications among patients with IBD 2,3 . OBJECTIVES: Develop an individualized prognostic risk prediction tool for predicting the probability of adverse COVID-19 outcomes in patients with IBD. DESIGN SETTING AND PARTICIPANTS: This study developed and validated prognostic penalized logistic regression models 4 using reports to Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) from March-October 2020. Model development was done using a training data set (85% of cases reported March 13 - September 15, 2020), and model validation was conducted using a test data set (the remaining 15% of cases plus all cases reported September 16-October 20, 2020). MAIN OUTCOMES AND MEASURES: COVID-19 related:Hospitalization+: composite outcome of hospitalization, ICU admission, mechanical ventilation, or deathICU+: composite outcome of ICU admission, mechanical ventilation, or deathDeathWe assessed the resulting models' discrimination using the area under the curve (AUC) of the receiver-operator characteristic (ROC) curves and reported the corresponding 95% confidence intervals (CIs). RESULTS: We included 2709 cases from 59 countries (mean age 41.2 years [s.d. 18], 50.2% male). A total of 633 (24%) were hospitalized, 137 (5%) were admitted to the ICU or intubated, and 69 (3%) died. 2009 patients comprised the training set and 700 the test set.The models demonstrated excellent discrimination, with a test set AUC (95% CI) of 0.79 (0.75, 0.83) for Hospitalization+, 0.88 (0.82, 0.95) for ICU+, and 0.94 (0.89, 0.99) for Death. Age, comorbidities, corticosteroid use, and male gender were associated with higher risk of death, while use of biologic therapies was associated with a lower risk. CONCLUSIONS AND RELEVANCE: Prognostic models can effectively predict who is at higher risk for COVID-19-related adverse outcomes in a population of IBD patients. A free online risk calculator ( https://covidibd.org/covid-19-risk-calculator/ ) is available for healthcare providers to facilitate discussion of risks due to COVID-19 with IBD patients. The tool numerically and visually summarizes the patient's probabilities of adverse outcomes and associated CIs. Helping physicians identify their highest-risk patients will be important in the coming months as cases rise in the US and worldwide. This tool can also serve as a model for risk stratification in other chronic diseases. KEY POINTS: Question: How well can a multivariable risk model predict the risk of hospitalization, intensive care unit (ICU) stay, or death due to COVID-19 in patients with inflammatory bowel disease (IBD)?Findings: Multivariable prediction models developed using data from an international voluntary registry of IBD patients and available for use online ( https://covidibd.org/ ) have very good discrimination for predicting hospitalization (Test set AUC 0.79) and excellent discrimination for ICU admission (Test set AUC 0.88) and death (Test set AUC 0.94). The models were developed with a training sample of 2009 cases and validated in an independent test sample of 700 cases comprised of a random sub-sample of cases and all cases entered in the registry during a one-month period after model development. Meaning: This risk prediction model may serve as an effective tool for healthcare providers to facilitate conversations about COVID-19-related risks with IBD patients.

Beyond Two Cultures: Cultural Infrastructure for Data-driven Decision Support.

In the twenty years since Dr. Leo Breiman's incendiary paper Statistical Modeling: The Two Cultures was first published, algorithmic modeling techniques have gone from controversial to commonplace in the statistical community. While the widespread adoption of these methods as part of the contemporary statistician's toolkit is a testament to Dr. Breiman's vision, the number of high-profile failures of algorithmic models suggests that Dr. Breiman's final remark that "the emphasis needs to be on the problem and the data" has been less widely heeded. In the spirit of Dr. Breiman, we detail an emerging research community in statistics - data-driven decision support. We assert that to realize the full potential of decision support, broadly and in the context of precision health, will require a culture of social awareness and accountability, in addition to ongoing attention towards complex technical challenges.