O1/W/O2 double emulsion gels based on nanoemulsions and Pickering particles for co-encapsulating quercetin and cyanidin: A functional fat substitute.

An O1/W/O2 double emulsion gel, as a functional fat substitute and based on nanoemulsions and hydrophobic Pickering particles, is prepared by two-step emulsification to co-encapsulate hydrophilic cyanidin and hydrophobic quercetin. Nanoemulsions loading quercetin are fabricated by Tween-80 and combining high-speed and high-pressure emulsification. Phytosterol nanoparticles stabilize the W-O2 interface of the secondary emulsion to load cyanidin in the W phase. The concentration of Tween-80 is optimized as 0.3% by the droplet size and viscosity of nanoemulsions. The structural stability of double emulsion gels will be weakened along with the increase of nanoemulsions, showing lower modulus and encapsulation efficiency (EE) and bigger droplets. In double emulsion gels, the EE of quercetin and cyanidin reaches 93% and 85.6%, respectively. Analysis of molecular interaction indicates that Tween-80 would decrease the in-situ hydrophobicity of phytosterol nanoparticles by hydrogen bonding adsorption, thereby weakening the emulsification. The pH-chromic 3D printing of double emulsion gels is designed according to the pH sensitivity of cyanidin. Texture profile analysis is performed to test the textural properties of 3D-printed objects. The simulated digestion is conducted on double emulsion gels. The double emulsion gel with fewer nanoemulsions is beneficial for protecting quercetin and improving the delivery due to the higher structural stability, while that with more nanoemulsions is conducive to the digestion of cyanidin and camellia oil due to weakened semi-solid properties. This double emulsion gel further simulates fat tissues by co-encapsulating hydrophilic and hydrophobic substances, promoting the application of fat substitutes in the food industry.

Synthesis of Nanosized γ-Cyclodextrin Metal-Organic Frameworks as Carriers of Limonene for Fresh-Cut Fruit Preservation Based on Polycaprolactone Nanofibers.

To address the issue of bacterial growth on fresh-cut fruits, this paper reports the synthesis of nanosized γ-cyclodextrin metal-organic frameworks (CD-MOFs) using an ultrasound-assisted method and their application as carriers of limonene for antibacterial active packaging. The effects of the processing parameters on the morphology and crystallinity of the CD-MOFs are investigated, and the results prove that the addition of methanol is the key to producing nanosized CD-MOFs. The limonene loading content of the nanosized CD-MOFs can reach approximately 170 mg g-1. The sustained-release behaviors of limonene in the CD-MOFs are evaluated. Molecular docking simulations reveal the distribution and binding sites of limonene in the CD-MOFs. CD-MOFs are deposited on the surfaces of polycaprolactone (PCL) nanofibers via an immersion method, and limonene-loaded CD-MOF@PCL nanofibers are prepared. The morphology, crystallinity, thermal stability, mechanical properties, and antibacterial activity of the nanofibers are also studied. The nanofiber film effectively inhibits bacterial growth and prolongs the shelf life of fresh-cut apples. This study provides a novel strategy for developing antibacterial active packaging materials based on CD-MOFs and PCL nanofibers.

Edible polysaccharide-based oleogels and novel emulsion gels as fat analogues: A review.

Polysaccharide-based oleogels and emulsion gels have become novel strategies to replace solid fats due to safe and plentiful raw material, healthier fatty acid composition, controllable viscoelasticity, and more varied nutrition/flavor embedding. Recently, various oleogelation techniques and novel emulsion gels have been reported further to enrich the potential of polysaccharides in oil structuring, in which a crucial step is to promote the formation of polysaccharide networks determining gel properties through different media. Meanwhile, polysaccharide-based oleogels and emulsion gels have good oil holding, nutrient/flavor embedding, and 3D food printability, and their applications as fat substitutes have been explored in foods. This paper comprehensively reviews the types, preparation methods, and mechanisms of various polysaccharide-based oleogels and emulsion gels; meanwhile, the food applications and new trends of polysaccharide-based gels are discussed. Moreover, some viewpoints about potential developments and application challenges of polysaccharide-based gels are mentioned. In the future, polysaccharide-based gels may be flexible materials for customized nutritional foods and molecular gastronomy. However, it is still a challenge to select the appropriate oleogels or emulsion gels to meet the requirements of the products. Once this issue is addressed, oleogels and emulsion gels are anticipated to be used widely.

Reversible organohydrogels based on dynamic hydrogen bonding among water, dimethyl sulfoxide, and polyethylene glycol.

Facile gelation and degelation have been achieved by dynamic hydrogen bonding among dimethyl sulfoxide, water, and polyethylene glycol to prepare anti-freezing, drying-resistant, strongly thixotropic, and water-sensitive organohydrogels that are significant for biomaterial protection and storage.

Double network oleogels co-stabilized by hydroxypropyl methylcellulose and monoglyceride crystals: Baking applications.

Edible double network oleogels were prepared by hydroxypropyl methylcellulose (HPMC) and glyceryl monostearate (GMS) by the cryogel-templated method. Hot GMS soybean oil solutions were absorbed by HPMC cryogels, which were further homogenized and cooled to form oleogels containing both the HPMC network and GMS network. The crystal network constructed by GMS crystal clusters significantly enhanced the mechanical and rheological attributes of oleogels. Both the HPMC network and the GMS network were built up due to hydrogen bonds. According to the normalization analysis of FTIR and the deepening of the shift of the absorption peak, hydrogen bonds could also be formed between HPMC and GMS to connect the two independent networks. Double network oleogels were further used to fabricate cookies and cakes, assessed by the texture profile analysis. The combination of the HPMC network and GMS network in preparing oleogels will promote the application of oleogels as the fat replacer.

Synergetic effects of water-soluble polysaccharides for intensifying performances of oleogels fabricated by oil-absorbing cryogels.

Oleogels were prepared by the cryogel-templated method from porous cryogels, which were co-structured using hydroxypropyl-methylcellulose and structural enhancers (such as flaxseed gum, κ-carrageenan, carboxymethyl-cellulose, arabic gum, and guar gum). The hardness, network density, pore size, pore volume, and SEM micrographs of cryogels showed that κ-carrageenan and flaxseed gum could keep the integrity of aqueous foams during freeze-drying and endow cryogels with the high hardness and content to hold oils (>98%). Oil absorption curves indicated that flaxseed gum and guar gum-enhanced cryogels provided the fastest oil absorption rate due to bigger pores. The absorption model was fitted well with all experimental data. Physical and mechanical properties of cryogels were positively related to the rheological property and oil bonding capacity of oleogels. κ-carrageenan and flaxseed gum were more suitable as structural enhancers to improve hydroxypropyl-methylcellulose-based cryogels for preparing oleogels to replace plastic fats in foods.

Soft κ-carrageenan microgels stabilized pickering emulsion gels: Compact interfacial layer construction and particle-dominated emulsion gelation.

HYPOTHESIS: The well-known gelling ability of κ-carrageenan can make aqueous solutions into soft materials, which are crisp and can be mechanically treated into the nano-sized microgel particle (MP) as the building block for constructing the Pickering emulsion gel (PEG). MPs are expected to adhere and further create the network structure in PEGs due to their viscoelastic texture. Herein, properties of PEGs should be possibly altered by using MPs with different pH and ionic strength. EXPERIMENTS: MPs were prepared by shearing and gelling κ-carrageenan solutions simultaneously. Effects of pH and ionic strength on MPs were formulated, and physical properties of PEGs prepared from corresponding MPs were investigated. The interaction between κ-carrageenan molecules was analyzed by FTIR, and the formation process of the interfacial layer was traced by the interfacial rheological technique. FINDINGS: The moderate K+ could increase the flocculation and hardness of MPs to improve the viscoelasticity of PEGs. Prepared MPs were more favorable for forming PEGs when pH was 8 and 9. The oil fraction impacted physical properties of PEGs slightly. MPs constantly moved to the interface from the continuous phase, forming the compact adsorption layer due to the extrusion of MPs.

Carbapenem and cefoxitin resistance of Klebsiella pneumoniae strains associated with porin OmpK36 loss and DHA-1 ß-lactamase production.

Clinical isolates of carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) strains are being increased worldwide. Five pan-resistant K. pneumoniae strains have been isolated from respiratory and ICU wards in a Chinese hospital, and reveal strong resistance to all ß-lactams, fluoroquinolones and aminoglycosides. Totally 27 ß-lactamase genes and 2 membrane pore protein (porin) genes in 5 K. pneumoniae strains were screened by polymerase chain reaction (PCR). The results indicated that all of 5 K. pneumoniae strains carried blaTEM-1 and blaDHA-1 genes, as well as base deletion and mutation of OmpK35 or OmpK36 genes. Compared with carbapenem-sensitive isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the resistant isolates markedly lacked the protein band of 34-40 kDa, which might be the outer membrane proteins of OmpK36 according to the electrophoresis mobility. In addition, the conjugation test was confirmed that blaDHA-1 mediated by plasmids could be transferred between resistant and sensitive strains. When reserpine (30 µg/mL) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) (50 µg/mL) were added in imipenem and meropenem, the MICs had no change against K. pneumoniae strains. These results suggest that both DHA-1 ß-lactamase and loss or deficiency of porin OmpK36 may be the main reason for the cefoxitin and carbapenem resistance in K. pneumoniae strains in our hospital.

Expression of enterovirus 71 capsid protein VP1 in Escherichia coli and its clinical application

The VPl gene of enterovirus 71 (EV71) was synthesized, construct a recombinant plasmid pET15b/VP1 and expressed in E. coli BL21. The recombinant VP1 protein could specifically react with EV71-infected patient sera without the cross-reaction with serum antibodies of coxsackievirus A16 (CA16), A4, A5, B3 and B5 as well as echovirus 6. In acute and convalescent phases, IgM and IgG antibodies of 182 serum samples were detected by ELISA with recombinant VP1 protein as a coated antigen. The results showed that the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IgM antibodies in serum samples for the diagnosis of EV71 infection were 90.1, 98.4, 98.8 and 88.7%, respectively; similarly, those of IgG antibodies in serum samples were 82.4, 89.1, 91.5 and 78.1%, respectively. Five of 80 samples (6.25%) from CA16infected patients were detected positive by ELISA with recombinant VP1 protein in which indicated the cross reactions and 0 of 5 samples from patients infected with other enteroviruses including CA4, CA5, CB3, CB5 and echovirus 6. Therefore, the recombinant VP1 protein of EV7l may provide a theoretical reference for establishing an effective antibody screening of IgM for EV71-infected patients with clinically suspected hand, foot, and mouth disease (HFMD).

Expression of enterovirus 71 capsid protein VP1 in Escherichia coli and its clinical application.

The VPl gene of enterovirus 71 (EV71) was synthesized, construct a recombinant plasmid pET15b/VP1 and expressed in E. coli BL21. The recombinant VP1 protein could specifically react with EV71-infected patient sera without the cross-reaction with serum antibodies of coxsackievirus A16 (CA16), A4, A5, B3 and B5 as well as echovirus 6. In acute and convalescent phases, IgM and IgG antibodies of 182 serum samples were detected by ELISA with recombinant VP1 protein as a coated antigen. The results showed that the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IgM antibodies in serum samples for the diagnosis of EV71 infection were 90.1, 98.4, 98.8 and 88.7%, respectively; similarly, those of IgG antibodies in serum samples were 82.4, 89.1, 91.5 and 78.1%, respectively. Five of 80 samples (6.25%) from CA16-infected patients were detected positive by ELISA with recombinant VP1 protein in which indicated the cross reactions and 0 of 5 samples from patients infected with other enteroviruses including CA4, CA5, CB3, CB5 and echovirus 6. Therefore, the recombinant VP1 protein of EV7l may provide a theoretical reference for establishing an effective antibody screening of IgM for EV71-infected patients with clinically suspected hand, foot, and mouth disease (HFMD).

Carbapenem and cefoxitin resistance of Klebsiella pneumoniae strains associated with porin OmpK36 loss and DHA-1 β-lactamase production

Clinical isolates of carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) strains are being increased worldwide. Five pan-resistant K. pneumoniae strains have been isolated from respiratory and ICU wards in a Chinese hospital, and reveal strong resistance to all β-lactams, fluoroquinolones and aminoglycosides. Totally 27 β-lactamase genes and 2 membrane pore protein (porin) genes in 5 K. pneumoniae strains were screened by polymerase chain reaction (PCR). The results indicated that all of 5 K. pneumoniae strains carried blaTEM-1 and blaDHA-1 genes, as well as base deletion and mutation of OmpK35 or OmpK36 genes. Compared with carbapenem-sensitive isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the resistant isolates markedly lacked the protein band of 34-40 kDa, which might be the outer membrane proteins of OmpK36 according to the electrophoresis mobility. In addition, the conjugation test was confirmed that blaDHA-1 mediated by plasmids could be transferred between resistant and sensitive strains. When reserpine (30 µg/mL) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) (50 µg/mL) were added in imipenem and meropenem, the MICs had no change against K. pneumoniae strains. These results suggest that both DHA-1 β-lactamase and loss or deficiency of porin OmpK36 may be the main reason for the cefoxitin and carbapenem resistance in K. pneumoniae strains in our hospital.

[Clinical analysis of bronchial foreign bodies in 246 children].

OBJECTIVE: To analyze the characters of bronchial foreign bodies in children and the utilization of bronchoscope in the treatment of bronchial foreign bodies. METHODS: A total of 246 children were diagnosed with bronchial foreign bodies at our hospital during January 2000 until August 2009. Under local mucosal anesthesia, a bronchoscope was inserted through nasal cavity into bronchi. After identifying the site of foreign body, grasping forceps was guided through bronchoscope to remove the foreign body from airway. RESULTS: Among 246 cases, hard nut and skin of melon seed were found (n = 230, 93.5%). The most common site of foreign body was in right lower lobe bronchi (n = 98, 38.9%). The average operative frequency was 1.9 +/- 1.3 and one-time extraction ratio 58.5% (n = 144). The one-time extraction ratio of patients with foreign body obstructed in main bronchi (91.1%), right middle lobe (60.0%) and right lower lobe (55.1%) was higher than others. The operation frequency of using basket grasping forceps (1.4 +/- 0.9) was lower than those using tooth type forceps (2.1 +/- 1.4). And the difference was significant (P = 0.000). CONCLUSION: For bronchial foreign body in pediatric patients, hard nut and skin of melon seed are the most common foreign bodies. The right and left lower lobe bronchi are the predilection site. Foreign body in main bronchus is the easiest to be removed by grasping forceps. For massive foreign bodies, basket grasping forceps fares better than tooth grasping forceps.

[Measurement of pulmonary function with body plethysmograph in infants].

OBJECTIVE: To observe the alterations of pulmonary function in infants with respiratory diseases. METHODS: A total of 900 infants with respiratory diseases were recruited and pulmonary function measured in 30 healthy infants. The tests were performed in the sleeping infants with sedation. Tidal breathing flow-volume (TBFV) loops were recorded when infants were breathing quietly. Passive flow-volume technique was used to obtain static respiratory system compliance and resistance. Functional residual capacity was measured by body plethysmograph. RESULTS: The TBFV loop showed proximate round or oval curve in healthy infants. The shape and parameters of TBFV loop had significant differences in infants with respiratory diseases as compared with healthy controls. The TBFV loop displayed a concave expiratory curve and ratio of time to reach tidal peak flow to total expiratory time, the expiratory volume till peak flow divided by the total expiratory volume significantly decreased in infants with small airway obstruction. The expiratory or inspiratory curve showed a plateau and the ratio of mid-expiratory to mid-inspiratory flow was less than 60% or over 150% in infants with upper airway obstruction. The TBFV loop turned narrow and lung volume decreased in infants with restrictive diseases. CONCLUSION: The TBFV loop show proximate round or oval curve in healthy infants. Pulmonary function has significant differences between healthy controls and infants with respiratory diseases. Pulmonary function test is useful in the assessment of respiratory diseases.

Brief report: An epidemiologic survey of the prevalence of sleep disorders among children 2 to 12 years old in Beijing, China.

OBJECTIVE: This survey was conducted to examine the prevalence of sleep disorders in 2- to 12-year-old children in the Beijing area of China. METHODS: From October 2001 to June 2002, 5979 children 2 to 12 years old in 6 randomly selected counties in Beijing were investigated with questionnaires. RESULTS: The average total sleep time per day ranged from 11.38 hours among 2-year-olds down to 9.34 hours among 12-year-olds. The overall prevalence of sleep disorders was 21.2% and included parasomnia symptoms (bruxism [6.5%], sleep talking [4.9%], enuresis [1.0%], sleepwalking [0.6%], restless sleep [5.0%], and leg movements [1.9%]) and symptoms of sleep-disordered breathing (frequent snoring [5.6%], mouth breathing [4.1%], choking/gasping [0.9%], and breathing pauses [0.2%]). CONCLUSION: The overall prevalence of parent-reported symptoms of sleep disorders in a large sample of children in Beijing, China, was comparable to that reported in other countries, although the prevalence of some specific symptoms differed somewhat.

[Role of flexible bronchoscopy in the treatment of infection-associated atelectasis in children].

OBJECTIVE: Infection-associated atelectasis is rather common during childhood and the effects of drug therapy are often unsatisfactory. The present study aimed to evaluate the effectiveness of flexible bronchoscopy in the treatment of infection-associated atelectasis in children. METHODS: One hundred and twenty-five patients (68 male and 57 female; age ranged from 10 d to 14 years and their courses of disease were from 3 d to 2.5 years) with infection-associated atelectasis confirmed by chest X-ray or CT were enrolled in the study. The following conditions were excluded by bronchoscopy: airway foreign body, airway anomalies, tumor, tuberculosis. The patients were divided into two groups: flexible bronchoscopy group and medication group. In the flexible bronchoscopy group, 65 patients were treated mainly with flexible bronchoscopy whereas in medication 60 group patients only received medication. Chest X-ray or CT was regularly reviewed for every patient, meanwhile the effect of flexible bronchoscopy at different courses of disease was observed. RESULTS: Flexible bronchoscopy group and medication group had no significant differences in age, sex and course of disease (P > 0.05). In flexible bronchoscopy group 39 patients were cured, 20 were improved and 6 cases had no change; in medication group 17 patients were cured, 25 were improved and 18 had no change. The two groups had significant differences (P < 0.01); in bronchoscopy group there were significant differences among patients with the courses of disease less than 3 months, 3 to 6 months and more than 6 months. CONCLUSIONS: The authors concluded that flexible bronchoscopy was an effective method for treatment of infection-associated atelectasis. Flexible bronchoscopy can reach pathological part and clear pus and granulation. It can remove obstruction and relieve symptoms. When course of disease was short, bronchoscopic therapy was advantageous to recovery of atelectasis. Bronchial washing may overcome the shortcomings of bronchoalveolar lavage, therefore the former seemed to be more suitable for treatment of infection-associated atelectasis.

[Pulmonary function in infants with respiratory syncytial virus bronchiolitis].

OBJECTIVE: To observe the dynamics of pulmonary function in infants with respiratory syncytial virus (RSV) bronchiolitis. METHODS: The to test the pulmonary function of 31 infants with RSV bronchiolitis during acute phase at admission was tested. Pulmonary fuction test was performed for the second time among 17 out of the 31 infants during the clinical recovery phase, and performed for the third time among 10 out of the 17 infants one week after discharge. In the meantime pulmonary function test was performed in 74 healthy infants as controls. RESULTS: During the acute phase of RSV bronchiolitis, the respiratory rate (RR), peak tidal expiratory flow (PTEF), peak tidal flow/tidal volume (PF/Ve), respiratory system resistance (Rrs), and functional residual capacity per kilogram (FRC/kg) were significantly increased, while the inspiratory tidal volume (Vi), inspiratory volume per kilogram (Vi/kg), expiratory tidal volume (Ve), percent of tidal volume to peak tidal expiratory flow (%V-PF), terminal flows/peak expiratory flow (25/PF), respiratory system compliance (Crs), and respiratory system compliance per kilogram (Crs/kg) were significantly decreased as compared with those in healthy infants. Ratio of mid-expiratory to mid-inspiratory flow (ME/MI) and respiratory system time constant (Trs) showed no statistically significant differences. The tidal breathing flow-volume (TBFV) loop displayed a concave expiratory curve. During the clinical recovery phase, the above abnormal indexes showed significant improvement, except for the %V-PF, 25/PF and Crs/kg which were still lower as compared with those in healthy infants, most indexes had returned to normal. The TBFV loop showed mild decelerating expiratory limb. One week after discharge all of the indexes returned to normal. CONCLUSION: In the acute phase of RSV bronchiolitis higher resistance in small airway and obstructive ventilatory disturbance can be seen. Some of the indexes remain abnormal during the clinical recovery phase. However, the abnormalities disappear in a short time. Pulmonary function test is a valuable way for surveillance of the course and prognosis of RSV bronchiolitis. %V-PF, 25/PF, and FRC/kg are sensitive indexes.