Fortification of puffed biscuits with chitin and crayfish shell: Effect on physicochemical property and starch digestion.

Chitin is a polysaccharide and possesses numerous beneficial properties such as nontoxicity, biodegradability and biocompatibility, which draws much attention to its applications in food. Crayfish shell is a source of chitin alongside an antioxidants and a potential source of beneficial dietary fiber. In this study, chitin (CH) and crayfish shell (CS) with different concentrations were used to study their impact on pasting characteristics of flour mixture (wheat flour and glutinous rice flour) and influence on physicochemical and starch digestion property of puffed biscuit. The Rapid Visco-Analyzer results showed that the viscosity of powder mixture was decreased with the ratio of CH and CS increased. CH resulted in lowest peak viscosity and breakdown values of mixed powder. It was indicated that increasing amounts of CH and CS led to significantly reduced moisture content, expansion ratio but raised density of biscuits. CH and CS inhibited starch digestion and promoted a remarkable increase (P < 0.05) of resistant starch (RS) content. The hydrolysis kinetic analysis suggested a decelerating influence of CH on the hydrolysis content with lower values of equilibrium hydrolysis percentage (C∞) while CS on hydrolysis rate with lower kinetic constant (K). The estimated glycemic index (eGI) of the CH (15-20%) samples were below 55. These results are of great significance in delaying starch digestion and provided a better choice in design of fried puffed snacks for special crowd with chronic diseases such as diabetes, cardiovascular disease, and obesity.

Preparation, Characterization, and Application of Modified Starch/Chitosan/Sweet Orange Oil Microcapsules.

Aquatic products have an important role in global agriculture, but the challenges associated with preservation have limited their marketability. Essential oil (EO), such as sweet orange oil (SOEO), has been widely used for preservation due to its excellent antibacterial ability. However, the volatilization of EO limits its application in food preservation. In this study, SOEO was extracted from sweet orange peel by steam distillation and then stored in microcapsules. The components of the microcapsules were as follows: the porous starch was chosen as an adsorbed substrate to store SOEO (PS/SOEO), and sodium alginate (SA) and chitosan (CMCS) were used as shell material to delay the volatilization of SOEO using the sharp pore coagulation method. Our results showed that the main antibacterial ingredients in SOEO were aldehydes (33.93%) and d-limonene (15.38%). The microcapsules were of an irregular shape (oval), and the size of the microcapsules was 1.2 ± 0.1 cm as measured by a digital micrometer. Scanning electron microscopy (SEM) results showed that there were a lot of pores on the surface of the starch after modification, but sodium alginate and chitosan could well encapsulate these pores. The results of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis also showed that SOEO was successful encapsulated into the porous starch. The results of compression test and releasing kinetics studies suggested that CMCS and SA improved the mechanical and slow-releasing ability of SOEO microcapsules. The best antibacterial performance was obtained when 0.8 g of SOEO microcapsules was added. Finally, the shelf life of crawfish could be extended to 6 days by SOEO microcapsule (1/10 g, SOEO microcapsule/crawfish) under room temperature. These results provide a systematic understanding of the antibacterial capabilities of sweet orange essential oil microcapsules, which can contribute to the development of preservation methods for aquatic products.

[Transmission chains of clusters of COVID-19 associated with a market in Beijing].

Objective: To investigate the clusters of COVID-19 associated with a market (market Y) in Haidian District, Beijing, and analyze the chain of transmission and provide reference for effective prevention and control of COVID-19. Methods: The investigation of field epidemiology and cluster epidemic was used to describe the distributions of all COVID-19 cases. The time sequence diagram of the cases, disease onset was drawn and transmission chains were analyzed. Real-time RT-PCR assay was conducted for SARS-CoV-2 nucleic acid test by using the respiratory samples of the cases. Results: The COVID-19 epidemic, originated from a wholesale farm produce market (market X) in Fengtai District, Beijing, was introduced by a marketer in the market Y who had exposed to market X, causing 8 clusters of 20 confirmed cases of COVID-19 and one asymptomatic case, including 8 men and 13 women, in market Y, surrounding communities, food plaza, companies,families and other places. The incidence peaked during June 10-14, 2020; the median age of the cases was 45 years, ranging from 5 years to 87 years. The initial symptoms of the cases included fever (10/20) and pharynx discomfort (7/20). The median of incubation period was 5 days (IQR:3-8). The median of serial interval between primary case and secondary cases was 5 days with a secondary attack rate of 3.7%(20/538), and the secondary attack rate in household close-contacts was 14.0% (7/50). Conclusions: The clusters of COVID-19 associated with market Y were caused by several modes of transmission, including human-to-human, contaminated material-to-human, etc. The combined public-health response measures were effective to control the COVID-19 epidemic in Haidian district of Beijing.

A hospital-associated measles outbreak in health workers in Beijing: Implications for measles elimination in China, 2018.

BACKGROUND: Since the National Action Plan for Measles Elimination 2006-2012 was released in 2006, China has entered into an era of accelerated measles elimination. Despite substantial decline, measles outbreak continued to occur mainly in a non-targeted population, in particular health workers due to occupational exposure. We investigated a measles outbreak in a Chinese medicine hospital, Beijing, in March 2018. METHODS: Descriptive analysis was performed on epidemiology of the outbreak, clinical and laboratory evaluations, vaccination status of cases, and public health response. A case-control study was also conducted to identify the associated risk factors for measles. RESULTS: From March 13, 2018, through March 27, 2018, a total of 11 measles cases in health workers were reported in Hospital X, Beijing. The median age of cases was 26 years (range, 21-53) and 4 (36.4%) were male. Of the 11 cases, ten had not been vaccinated or had unknown vaccination status; two occurred in emergency departments. No inpatients became infected, 141 (83.9%) of whom in affected departments were 55 years of age or older. The outbreak was confirmed by laboratory testing; the virus strain was genotype H1. The response activities included isolation of cases, and enhanced health surveillance of health workers and inpatients, particularly in affected departments. A total of 2234 doses of measles-containing vaccines (MCVs) were administered, covering 93.3% of susceptible health workers, in addition to 973 doses to the susceptible individuals in household and community. Lack of documentation of MCV vaccination before the outbreak was identified as a risk factor for measles (odd ratio: 3.333, 95% confidence interval: 1.295-8.621). CONCLUSIONS: High coverage of outbreak response immunization activities contributed largely to limit the spread of measles and might provide an indirect protection for inpatients. 2-Dose measles-containing vaccination of personnel in healthcare settings is warranted to prevent potential nosocomial transmission of measles.

To establish a talent pool for global health in China: from political will to action.

Recently, China has played a more and more important role in global health, mainly by improving health outcomes of its own population nationwide and participating international health activities. In addition, China has participated in a dozen of international organizations, which all contained health domains, particularly the Belt and Road Initiative with an ambitious goal to improve health of the people in the countries alongside closely partnered with the World Health Organization. All these highlight the need of human resource for global health at the national level. The National Health and Family Planning Commission translated this political will into action - that a talent pool candidate for global health will be established in China. The establishment of the talent pool would be of great significance for China's engagement in global health activities. However, much work, such as training, collaboration, and innovation, etc., remains to be done in the future. Based on the successful practice, China can share lessons learned to other countries.

Sequencing of the complete mitochondrial genomes of eight freshwater snail species exposes pervasive paraphyly within the Viviparidae family (Caenogastropoda).

Phylogenetic relationships among snails (Caenogastropoda) are still unresolved, and many taxonomic categories remain non-monophyletic. Paraphyly has been reported within a large family of freshwater snails, Viviparidae, where the taxonomic status of several species remains questionable. As many endemic Chinese viviparid species have become endangered during the last few decades, this presents a major obstacle for conservation efforts. Mitochondrial genomes (mitogenomes) carry a large amount of data, so they can often provide a much higher resolution for phylogenetic analyses in comparison to the traditionally used molecular markers. To help resolve their phylogenetic relationships, the complete mitogenomes of eight Chinese viviparid snails, Viviparus chui, Cipangopaludina chinensis, C. ussuriensis, C. dianchiensis (endangered), Margarya melanioides (endangered), M. monodi (critically endangered), Bellamya quadrata and B. aeruginosa, were sequenced and compared to almost all of the available caenogastropod mitogenomes. Viviparidae possess the largest mitogenomes (16 392 to 18 544 bp), exhibit the highest A+T bias (72.5% on average), and some exhibit unique gene orders (a rearrangement of the standard MYCWQGE box), among the Caenogastropoda. Apart from the Vermetidae family and Cerithioidea superfamily, which possessed unique gene orders, the remaining studied caenogastropod mitogenomes exhibited highly conserved gene order, with minimal variations. Maximum likelihood and Bayesian inference analyses, used to reconstruct the phylogenetic relationships among 49 almost complete (all 37 genes) caenogastropod mitogenomes, produced almost identical tree topologies. Viviparidae were divided into three clades: a) Margarya and Cipangopaludina (except C. ussuriensis), b) Bellamya and C. ussuriensis, c) Viviparus chui. Our results present evidence that some Cipangopaludina species (dianchiensis and cathayensis) should be renamed into the senior genus Margarya. The phylogenetic resolution obtained in this study is insufficient to fully resolve the relationships within the 'b' clade, but if C. chinensis proves to be a valid representative of the genus, C. ussuriensis may have to be reassigned a different genus (possibly Bellamya, or even a new genus). Non-monophyly also remains pervasive among the higher (above the family-level) Caenogastropod taxonomic classes. Gene order distance matrix produced a different phylogenetic signal from the nucleotide sequences, which indicates a limited usability of this approach for inferring caenogastropod phylogenies. As phenotypic homoplasy appears to be widespread among some viviparid genera, in order to effectively protect the rapidly diminishing endemic Viviparid populations in China, further detailed molecular phylogenetic studies are urgently needed to resolve the taxonomic status of several species.

Epidemiology of varicella in Haidian district, Beijing, China-2007-2015.

BACKGROUND: 1-Dose varicella vaccination was recommended for children in Beijing before November 2012. To further control school-based outbreaks and decrease incidence, a 2-dose vaccination was implemented in 2013. We described the varicella epidemiology and assessed impact of the 2-dose vaccination in Haidian district, Beijing, 2007-2015. METHODS: We examined the estimated incidence and disease characteristics of varicella during 2007-2015 and obtained the 1-dose vaccination coverage for children born during 2005-2013. Number of vaccine doses given was used to indirectly reflect the second-dose vaccination coverage. Overall and age-specific estimated incidences were compared between 2007-2012 and 2013-2015. RESULTS: A total of 23,497 cases were reported during 2007-2015. Of the 23,497 cases, 13,440 (57.20%) were male, and 68.40% were <20years of age and 70.02% were students and children in kindergarten. The estimated incidence increased from 82 cases per 100,000 population in 2007 to 104 in 2011, before substantially decreasing from 86 in 2012 to 56 in 2015. The median age increased from 14years in 2007 to 18years in 2015. The 1-dose varicella coverage for children at ≥2years of age gradually increased from 74.21% in 2007 to 90.06% in 2015. Compared with 2007-2012, two-fold average vaccine doses were given during 2013-2015, and the overall estimated incidence declined by 34.4%, particularly in children aged 5-9years, with a significantly declined trend in children aged 1-9years and older adolescents aged 15-19years and non-significantly declined trend in adults aged ≥20years, but a significant increasing trend in infants. CONCLUSIONS: The overall incidence of varicella has decreased substantially in Haidian district since 2013, with largest decline in children aged 5-9years. The 2-dose varicella vaccination might not lead to increase in incidence in adults. Long-term surveillance is needed to fully evaluate the long-term impact of the 2-dose varicella vaccination.

Outbreak of varicella in a highly vaccinated preschool population.

BACKGROUND: Varicella vaccine is available for private purchase in Beijing, with single dose recommended for children aged ≥12 months before 2013. Despite the success achieved in reducing varicella incidence, varicella outbreaks continued to occur, including in schools and kindergartens among highly vaccinated children. We investigated a varicella outbreak in a preschool with high varicella vaccination coverage in Haidian district, Beijing. METHODS: Through questionnaires, data including children's medical and vaccination history were collected from their parents. A case of varicella was defined as an acute, generalized, maculopapulovesicular rash without other apparent cause in a child in the preschool from March 10 through March 29, 2010. Attack rates in vaccinated and unvaccinated children were calculated, and the analyses of vaccine effectiveness (VE) and of risk factors for breakthrough disease (varicella occurring >42 days after vaccination) were conducted. RESULTS: A total of 12 cases occurred during the outbreak, and ten of them (83.3%) had breakthrough varicella. The index case with mild varicella occurred in a child who had been vaccinated four years previously. Questionnaires were returned for all of 150 children in the preschool. Of all the 150 children, 144 (96.0%) had no prior history of varicella disease. Among these children, 135(93.7%) had received single-dose varicella vaccine before the outbreak. VE was 84.5% [95% confidence interval (CI): 62.8%∼93.5%] in preventing varicella of any severity, and VE was 92.2% (95% CI: 81.4%∼96.8%) against moderate to severe varicella. Age at vaccination (<15 months vs. ≥15 months) and time since vaccination before the outbreak (<3 years vs. ≥3 years) were not associated with the increased risk of breakthrough varicella(P=0.124 and 1, respectively). All the varicella cases with vaccination history verified through immunization records had received varicella vaccine and measles-mumps-rubella vaccine >30 days apart. CONCLUSIONS: Breakthrough infection with fever in vaccinated person may be as infectious as varicella in unvaccinated persons. High single-dose varicella vaccination coverage is effective in reducing varicella incidence, but not sufficient to prevent outbreak. To control varicella outbreak a second dose may deserve additional consideration.