Food protein aggregation and its application.

The phenomenon of protein aggregation in food science is very common, but the formation mechanism is unclear. The formation of protein aggregates (PAs) is influenced by various factors, and aggregates with different sizes and shapes play an important role in food systems. Although there have been many reports on food PAs, many challenges still need to be addressed, and a systematic literature review is lacking. Thus, hypotheses about the PAs formation mechanism were summarized, and the fibrosis aggregates formation mechanism was described. The main findings of this paper indicate that the forces driving protein aggregation are covalent and non-covalent cross-linking interactions. The determination of PAs is mainly based on protein particle size combined with multispectral methods. PAs are not only associated with protein functional properties (such as emulsion and gel) but also related to harmful substances (such as advanced glycation end products, AGEs) formation. Finally, the applications of PAs in food science were summarized. Outlook and challenges were described from the perspectives of food processing conditions and parameters, food components and their interactions, food nutrition and health relationships, etc. This review will attract more food scientists to participate in related research on protein aggregation in the future.

Development and characterization of aldehyde-sensitive cellulose/chitosan/beeswax colorimetric papers for monitoring kiwifruit maturity.

In this study, we developed an in-package colorimetric paper to monitor the ripeness of kiwifruit by detecting the release of aldehydes. Strongly hydrophobic composite films were prepared using chitosan as the matrix and beeswax as an additive. A piece of cellulose paper containing methyl red and bromocresol violet as color indicators was heat-sealed between two hydrophobic films to protect the indicators from the effects of fruit respiration and transpiration. The nucleophilic addition reaction between aldehydes and OH- (Cannizzaro reaction) changes the pH in the paper and triggers a color change in the indicators. As the kiwifruit ripens, the colorimetric paper changes from bluish-purple to dark red and then gradually to red. A mobile phone application was further used to measure the RGB values and link them to kiwifruit ripeness. This intelligent paper can be used for the accurate and convenient monitoring of produce in real time.

Development of the competency assessment scale for clinical nursing teachers: Results of a Delphi study and validation.

BACKGROUND: Highly competent clinical faculty is a prerequisite for graduating competent nurses, and it is very important to explore the comprehensive ability and post competence of clinical nursing teachers (CNT). OBJECTIVE: To construct the competency evaluation elements of clinical nursing teachers and test the reliability and validity of the scale. DESIGN: A Delphi study. SETTINGS: 34 Grade A tertiary hospitals and eight colleges and universities in China, covering 14 provinces, autonomous regions, and municipalities directly under the Central Government. METHODS: Modified Delphi method was used in this study. Between August 2018 and May 2019, 40 experts participated in three rounds of consultation to build the CNT competency assessment scale. The expert coordination coefficient (W) and the coefficient of variation (CV) were used to examine the level of coordination and concentration of expert advice. Then, the reliability and validity of the scale were tested. Using the convenient sampling method, a total of 190 questionnaires were distributed to nursing teachers, and 187 were recovered. Cronbach's α coefficient was used to evaluate the reliability of the scale. Validity was evaluated using the content validity index. RESULTS: After the three rounds of expert consultation, the questionnaire contained five dimensions and 44 elements. After expert inquiry, the total coefficient of variation index (CVI) value of the scale was 0.992, and the CVI of each item was 0.95-1.00. The Spearman-Brown correlation coefficient was 0.984. By comparing the results of the two surveys 2 months apart, the Pearson correlation coefficient was tested, and the retest reliability was 0.852. The Cronbach's α of the scale was 0.962, indicating excellent internal consistency. CONCLUSIONS: The scale of clinical nursing teachers' competence has high reliability and validity. This tool could be widely used to evaluate and improve nursing teaching.

Enhanced photocatalytic degradation of organic dyes by ultrasonic-assisted electrospray TiO2/graphene oxide on polyacrylonitrile/ß-cyclodextrin nanofibrous membranes.

Polyacrylonitrile (PAN)/ß-cyclodextrin (ß-CD) composite nanofibrous membranes immobilized with nano-titanium dioxide (TiO2) and graphene oxide (GO) were prepared by electrospinning and ultrasonic-assisted electrospinning. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) confirmed that TiO2 and GO were more evenly dispersed on the surface and inside of the nanofibers after 45 min of ultrasonic treatment. Adding TiO2 and GO reduced the fiber diameter; the minimum fiber diameter was 84.66 ± 40.58 nm when the mass ratio of TiO2-to-GO was 8:2 (PAN/ß-CD nanofibrous membranes was 191.10 ± 45.66 nm). Using the anionic dye methyl orange (MO) and the cationic dye methylene blue (MB) as pollutant models, the photocatalytic activity of the nanofibrous membrane under natural sunlight was evaluated. It was found that PAN/ß-CD/TiO2/GO composite nanofibrous membrane with an 8:2 mass ratio of TiO2-to-GO exhibited the best degradation efficiency for the dyes. The degradation efficiency for MB and MO were 93.52 ± 1.83% and 90.92 ± 1.52%, respectively. Meanwhile, the PAN/ß-CD/TiO2/GO composite nanofibrous membrane also displayed good antibacterial properties and the degradation efficiency for MB and MO remained above 80% after 3 cycles. In general, the PAN/ß-CD/TiO2/GO nanofibrous membrane is eco-friendly, reusable, and has great potential for the removal of dyes from industrial wastewaters.

Optimization, characterization and evaluation of papaya polysaccharide-corn starch film for fresh cut apples.

In this study, we prepared corn starch (CS) and papaya polysaccharide (PPs) films using the solution casting technique. A Box-Behnken experimental design was used to determine the effect of ethanol concentration, extraction duration, and material concentration during PPs extraction. The resulting films were characterized in terms of structural changes, physical, optical, mechanical, Fourier-transform infrared (FTIR) spectroscopy, and thermal properties. The results show that PPs-CS composite films have good antioxidant and moisturizing properties and general antibacterial performance. These results revealed that after adding PPs, the films exhibited a significant increase in swelling and tensile strength, while depicted a reduction in thickness, transparency, and solubility. SEM images revealed that PPs and CS are highly compatible; moreover, FTIR spectroscopy showed that intermolecular hydrogen bonding existed between CS and PPs, forming a compact film structure. Finally, the incorporation of PPs and CS influenced the shelf-life of fresh cut apples, with the edible film incorporated with PPs positively improving sensory acceptance of combined materials.

Cassava starch/carboxymethylcellulose edible films embedded with lactic acid bacteria to extend the shelf life of banana.

In this study, two different species of lactic acid bacteria (LAB) (Lactobacillus plantarum and Pedocococcus pentosaceus) with high exopolysaccharide (EPS) yield were selected from a pickled water. Further, edible films based on cassava starch (CS) were developed containing LAB, and sodium carboxymethylcellulose (CMC). After addition of probiotics, the antioxidant activity of the composite film was significantly enhanced. Further, as the probiotic content increased, the antioxidant activity continuously increased. Moreover, L. plantarum showed uniform distribution in the CS/CMC matrix, forming a denser structure, which effectively blocked the penetration of water molecules and exhibited ultraviolet protection. Finally, due to the intermolecular interaction between probiotics and the CS/CMC matrix, the water vapor and light transmission rates were reduced, effectively blocking water and light to prevent lipid oxidation deterioration in food packaging. Banana shelf life has qualitatively improved with 2% LAB added composite film and its application in food packaging has been affirmed.

Development and optimization of dynamic gelatin/chitosan nanoparticles incorporated with blueberry anthocyanins for milk freshness monitoring.

In this study, we prepared gelatin and chitosan as wall materials, and composites with a controlled release capability in a weak acidic environment were synthesized for loading and protecting anthocyanins. Fourier-transform infrared spectroscopy and scanning electron microscopy were used to assess the properties of the nanoparticles. The loading efficiencies and oxidation resistances of the proposed substances were measured. Under optimal conditions, the anthocyanins exhibited a loading efficiency of 83.81 %, and suitable long-term storage capacity at room temperature with a retention rate of ∼50 % after 15 d. When the nanoparticles were used for detecting the milk freshness, spoiled milk exhibited a reddish color, whereas the color of fresh milk did not change. Moreover, these nanoparticles exhibited a stable chroma in milk for 0-16 h. Therefore, the proposed pH responsive nanoparticles can provide a possibility for the dynamic monitoring of milk quality changes, or provide some reference value for future related research.

Evaluation of a Community Health Service Center-Based Intervention Program for Managing Chronic Heart Failure.

BACKGROUND: Although the role of primary care for the management of patients with chronic heart failure (CHF) has been highly recommended, structural involvement of primary care in heart failure (HF) management programs is extremely limited. AIMS: To examine the feasibility and applicability of two most recommended forms of care delivery mode, home visit and telephone support, for CHF management in the setting of community health service center (CHSC). STUDY DESIGN: Prospective study. METHODS: This study was conducted in two CHSCs in Beijing, China. Care delivery was led by trained general practitioners or community nurses via home visits in one CHSC and telephone support in the other. Data regarding the change in mortality and hospitalization rate during 12 months and self-care level at 6 months were prospectively collected and compared across the intervention groups. RESULTS: A total of 329 patients were included, with 142 in the home visit group and 187 in the telephone support group. Patients in both groups had frequent visits to CHSC (8.1±5.9 in the home visit and 7.7±4.1 in the telephone support group, p=0.45) during the follow-up period. Compared to the telephone support group, patients in the home visit group showed a reduction in all-cause mortality (14.1% versus 20.3%, p=0.14), one or more hospitalizations due to any cause (33.8% versus 44.2%, p=0.12) and one or more hospitalizations due to cardiac cause (17.6% versus 24.6%, p=0.13) in the home visit group. The absolute differences were 6.2% (95% CI: 1.9%, 14.3%), 8.4% (95% CI: 2.1%, 18.9%) and 7.3% (95% CI: 1.5%, 16.1%), respectively, although the results were not statistically significant. After 6 months of intervention, patients in both groups achieved marked improvement in self-care with reference to their own baseline values. CONCLUSION: Although no statistical difference was observed between the two care delivery approaches regarding the clinical outcomes of interest, given the high participation rates, the acceptable rate of adverse events, frequent CHSC visits and patients' preferences in the current study, it was concluded that CHSC might be the optimal setting for delivering care to CHF patients in China.

Malposition of peripherally inserted central catheter: experience from 3012 cancer patients.

The objectives of the study are to observe and analyze the causes of 237 patients' malposition peripherally inserted central catheter (PICC) from 3012 patients in clinical practice and to further explore the methods of its prevention and remedies, which can help to improve the skills of placing tubes, to efficiently avoid and reduce the occurrence of complications, and to alleviate the pains and cost of patients. From August 2000 to March 2012, 3012 cases receiving PICC were reviewed. The locations of the tube tips were recorded by chest X ray and summarized for analysis. Malposition was observed in 237 cases (7.87%). The most frequently occurring site was in the jugular vein followed by the axillary vein. By taking different remedies, all the malpositioned PICCs were relocated in the superior vena cava or subclavian vein. In order to secure the safety usage of PICC, the strict rules of handling, the skill and experience of operator, and cooperation patients are necessary.

Analysis of bowel sounds application status for gastrointestinal function monitoring in the intensive care unit.

The auscultation of bowel sounds (BS) has been neglected as a reliable tool for determining gastrointestinal (GI) functioning in the critically ill patient. This article considers the validity of BS auscultation in the assessment and management of critically ill patients and outlines how the information may be utilized for monitoring GI function. A descriptive, cross-sectional design with self-administered questionnaires was used to survey 132 nurses and 38 doctors in the 6 general intensive care units in Beijing hospitals. Descriptive statistics and chi-square test analyses were used to assess the level of knowledge about BS among Chinese doctors and nurses and to determine how they applied their BS auscultation findings in the care of critically ill patients. Bowel sounds were found to be the primary indicator for determining GI functioning in the unconscious, critically ill patient. However, only 11.4% of nurses and 47.6% of doctors could make correct clinical judgments on the basis of their auscultatory findings. The attitudes of nurses and doctors differed significantly on whether BS auscultation was needed to monitor GI function for unconscious patients. Bowel sounds auscultation remains an important indicator of GI function. Distinct and feasible standards regarding BS auscultation and results interpretation need to be established.

Bowel sounds and monitoring gastrointestinal motility in critically ill patients.

PURPOSE: The aims of this study were to determine whether bowel sounds auscultation is necessary in critically ill patients and to forecast the prospect of bowel sounds as a monitoring measurement in the intensive care unit (ICU). BACKGROUND: It has been suggested recently that bowel sounds are not an objective indicator of bowel motility and that auscultation should be abandoned. This has led to confusion as to whether bowel sounds auscultation should be continued in the ICU. DESCRIPTION OF THE PROJECT: A literature review of articles about bowel sounds and monitoring gastrointestinal motility in critically ill patients was conducted. OUTCOME: At present, there are no more suitable indicators for bedside monitoring of bowel function and motility than bowel sounds. Although they lack objectivity, bowel sounds give a lot of useful information about gastrointestinal motility. The problems are how to improve practice and assessment standards and enhance the precision of auscultation devices. CONCLUSION: Bowel sounds auscultation is necessary in the ICU. Effective application in critically ill patients requires reasonable practice and precise instrumentation.

Evaluation of emergency tourniquets for prehospital use in China.

OBJECTIVE: Massive hemorrhage is life-threatening during armed conflicts. Tourniquets are important medical devices used to reduce severe bleeding in trauma. The aim of this study was to empirically evaluate the current tourniquets used in China and provide information to emergency nurses in selecting the appropriate tourniquet. METHODS: Five tourniquets were self-applied by 20 healthy participants. The blood flow distal to the tourniquet site was assessed using vascular Doppler ultrasound. Application time, pain, numbness, and other parameters were evaluated. RESULTS: The bladder tourniquet and windlass tourniquet effectively occluded arterial blood flow with success rates higher than 75% in both the upper and lower extremities. The Cargo-strap was the fastest to apply, taking (7.22+/-2.30) s for the upper extremity and (6.48+/-2.40) s for the lower extremity. The rubber tube was the most painful, and the improvised tourniquet was the least efficient. The success rates were higher in the lower extremity than in the upper extremity (P less than 0.05, X(2) equal to 5.714). CONCLUSIONS: The bladder tourniquet and the windlass tourniquet are efficient tourniquets, although the windlass is superior with respect to portability and pain. The Cargo-strap and rubber tourniquets have several disadvantages that reduce their suitability for field use. The improvised tourniquet is not recommended because of low efficiency and severe pain during implementation.

[Effect of temperature of fluid infusion on diamine oxidase, MB isoenzyme of creatine kinase, creatine-kinase and lactate dehydrogenase in hemorrhagic shock rabbits].

OBJECTIVE: To investigate the effects of different temperatures of fluid infusion on diamine oxidase(DAO), MB isoenzyme of creatine kinase (CK-MB), creatine kinase (CK) and lactate dehydrogenase (LDH) in rabbit with hemorrhagic shock so as to provide a clue to improve the nursing care in patients with hemorrhagic shock. METHODS: An animal model of controlled hemorrhagic shock in rabbits as previously reported was used in this randomized experiment. Twenty-three rabbits were randomized to a warm fluid infusion group (n=8), a ambient-temperature fluid infusion group (n=7), and a cold fluid infusion group (n=8). The rabbits were then resuscitated with Ringer's lactate solution three times of that of blood loss. DAO and values of myocardial enzyme were measured before shock, during shock and 1 hour, 2 hours and 4 hours after fluid infusion, respectively. RESULTS: There was no significant difference in DAO and values of myocardial enzymes among groups, though there was a lower value in DAO and values of myocardial enzymes at 1 hour to 4 hours after warm fluid infusion. CONCLUSION: Our data indicate that warm fluid infusion in rabbit model of controlled hemorrhagic shock has some beneficial effect on some biochemical values. In view of this result, temperature of fluid infusion in nursing care for patients with hemorrhagic shock should pay more attention to.