[Implications for risk management of foodborne pathogens in China from the outbreak of monophasic salmonella enterica serovar Typhimurium contaminated chocolate products].

Outbreaks caused by highly industrialized food companies are characterized by cross-border, trans-regional, rapid and unpredictable, related to serious disease and economic burden. A cluster of cases with monophasic salmonella enterica serovar Typhimurium ST34 infection suspected to be associated with consumption of contaminated chocolate products have been reported in several Europe countries since December 2021. After retrospective investigations, the buttermilk circuit in the Belgian factory was suspected to be the point of origin of the contamination. This outbreak could provide a reference for the risk management of foodborne pathogens contamination in China. The objective of this paper was to summarize the process and characteristics of the outbreak of monophasic S. Typhimurium caused by contaminated chocolate products, analyze the characteristics of ST34 monophasic S. Typhimurium and the microbial management measures in the process of chocolate products, and systematically discuss the suggestions for the risk management of foodborne pathogens contamination and countermeasures for the rapid development of industrialization of food enterprises in China, in order to provide scientific and technological support for the prevention and control, prediction and early warning of sudden cases in China.

Accuracy of Nolla Method for Age Estimation of Northern Chinese Han Children.

ABSTRACT: Objective To study the accuracy of Nolla method for age estimation of Northern Chinese Han children aged between 5.00 and 14.99 years based on original transformation tables and multiple regression model. Methods A total of 2 000 orthopantomographs （OPGs） were collected from the Hospital of Stomatology, Xi'an Jiaotong University, including 1 000 males and 1 000 females. Development stage of 7 left mandibular permanent teeth （except third molars） was assessed based on Nolla method, then age estimation was conducted through transformation tables and multiple regression model, respectively. Firstly, the development stage results of 7 permanent teeth were added up and the estimated age was obtained through the original transformation tables. Secondly, 80% of the samples （80 males and 80 females in each age group） were randomly selected from 2 000 OPGs as the train set. The chronological age of the selected patients was taken as the dependent variable, while gender and the development stage results of 7 permanent teeth were taken as the independent variable to establish multiple regression model. The remaining 20% of the samples were substituted into the model as the test set, to verify the accuracy of age estimation by multiple regression model. Results Mean chronological ages of males and females were 10.03±0.09 years and 10.01±0.09 years, respectively. The age estimated by original transformation tables showed an overestimation for males （0.18 years on average） and an underestimation for females （0.02 years on average）, with mean absolute error （MAE） of 0.94 years and 0.97 years, respectively. While the results by multiple regression model showed that males were overestimated by 0.06 years on average and females were underestimated by 0.02 years on average. The MAE was 0.66 years and 0.77 years, respectively. Conclusion The Nolla method is suitable for age estimation of Northern Chinese Han children. Compared with the original transformation tables method, the multiple regression model is more accurate for age estimation.

Antiplatelet agents for the secondary prevention of ischaemic stroke in patients with or without renal dysfunction.

BACKGROUND AND PURPOSE: Studies on using antiplatelet agents for secondary prevention in ischaemic stroke patients with renal dysfunction are limited. The Taiwan Stroke Registry database was used to compare the efficacy of antiplatelet agents. METHODS: From the Taiwan Stroke Registry data, 39 174 acute ischaemic stroke patients were identified and were classified into three groups by antiplatelet agent: aspirin, clopidogrel and dual antiplatelet therapy (DAPT) with a combination of aspirin and clopidogrel. The re-stroke incidence and 1-year mortality were stratified by estimated glomerular filtration rate (eGFR) levels at admission: ≥90, 60-89 and <60 ml/min/1.73 m2 or on dialysis. RESULTS: Compared to the aspirin group, the re-stroke differences were not statistically significant for the clopidogrel group [adjusted subhazard ratio 0.95, 95% confidence interval (CI) 0.84-1.08] and the DAPT group (adjusted subhazard ratio 1.03, 95% CI 0.77-1.39) after controlling for the competing risk of death. The mortality rate increased as the eGFR level declined. In addition, compared to patients taking aspirin, there was no statistically significant difference in overall 1-year mortality for the clopidogrel group (adjusted hazard ratio 1.11, 95% CI 0.95-1.29) and for the DAPT group (adjusted hazard ratio 1.01, 95% CI 0.67-1.54). The results were consistent in different subgroups stratified by eGFR levels. CONCLUSIONS: There was no difference in the risks of recurrent stroke and 1-year mortality amongst ischaemic stroke patients with or without renal dysfunction receiving antiplatelet agents with aspirin, clopidogrel or dual agents with a combination of aspirin and clopidogrel, regardless of their renal dysfunction status.

[Molecular epidemiology of Listeria monocytogenes isolated from ready-to-eat food in 2017 in China].

Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion: Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

[Research Progress and Prospect of Facial Reconstruction in Forensic Science].

ABSTRACT: Facial reconstruction is a way to recover facial morphology by restoring soft tissues based on unidentified skulls using the knowledge of anatomy, anthropology, aesthetics, and computer science. It is applied in forensic science, oral plastic surgery and archeology, and especially plays an important role in the identification of the origin of the unknown corpses in forensic science. Facial reconstruction is the supplementary means of identification when other approaches （such as DNA comparison, imaging matching, dental records comparison, etc.） cannot identify individual identity. Facial soft tissue thickness （FSTT） is the basis of facial reconstruction and with the development of imaging and computer science, the techniques for measuring FSTT are improving rapidly and many related researches have appeared. This paper summarizes the application of facial reconstruction in forensic science, the accuracy of different methods and the research progress of this field to provide reference to this field.

Research Progress of Age Estimation Based on the Demirjian's Method.

ABSTRACT: In recent years, individual age estimation has gained increasing attention in forensic practice. Common age estimation methods mainly use developments of teeth and bones. Compared with bones, teeth are stronger and are highly resistant to external factors, therefore plays an important role in age estimation. Demirjian's method is one of the most commonly used methods to evaluate dental age and has been widely used in many countries. In this paper, the accuracy of its application in different populations is reviewed. It is found that compared with the chronological ages, most of the estimated ages are overestimated. By combining research results of many scholars and by analyzing, it can be assumed that this situation may be related with race, region, sex, etc.

Construction of Age Estimation Model of 18-Year-Olds in the Northern Chinese Population Based on the Development of Mandibular Second and Third Molars.

ABSTRACT: Objective To establish a linear relationship between age and the development process of the mandibular second, third molars in a northern Chinese population and test its accuracy in inferring whether the subject is over 18 years old. Methods The orthopantograms （OPGs） of 960 northern Chinese people aged between 10.00 to 25.99 years were selected. The gender, birth date, and date of the orthopantograms of each sample were recorded. The development stages of left mandibular second and third molars were divided with Demirjian method. The experimental group （760 individuals） constructed a Logistic regression equation to infer whether the subject is over 18 years old. The validation group （200 individuals） tested the accuracy of the equation. Results When only using third molar, the formula obtained for inferring whether the subject's age is over 18 years is： logit P1=-18.276+0.494 x1+2.953 x3. When combining the second and the third molars, the formula is： logit P2=-21.045+3.177 x1+0.619 x2+2.088 x3. （x1 stands for gender, male is marked as 1 and female is marked as 2; x2 and x3 stand for the development stage of second molar and third molar, respectively）. The accuracy rates of this equation in estimating whether ages of subjects from the validation group were over 18 years old for males and females were 88.0%-92.0% and 85.0%-88.0%, respectively. Conclusion The age estimation formulas based on the development of mandibular second and third molars have important value in judging whether the individual is over 18 years old. Meanwhile, the accuracy of age estimation can be improved by combining the development of second and third molars together.

[Effects of nasogastric and percutaneous endoscopic gastrostomy tube feeding on the susceptibility of pulmonary infection in long-term coma patients with stroke or traumatic brain injury].

Objective: To investigate the effects of nasogastric tube (NGT) and percutaneous endoscopic gastrostomy (PEG) tube feeding on the susceptibility of pulmonary infection in long-term coma patients with stroke or traumatic brain injury. Methods: A total of 295 candidates who were in long-term coma after stroke or traumatic brain injury but without pulmonary infection and eligible for PEG catheterization were screened prospectively between January 2014 and February 2018. The patients were divided into PEG group (86 patients) and NGT group (209 patients) according to the choice of next-of-kin. Data related to the susceptibility of pulmonary infection were collected and analyzed in the two groups one month after the catheterization. Results: After follow-up for one month, compared with NGT group, patients in PEG group had a lower incidence of pulmonary infection (23.3% vs 37.8%, P=0.023), a later occurrence of pulmonary infection (average time: 21 days vs 13 days, P=0.034), and a less severe pulmonary infection (7.0% vs 12.9%, P=0.029). The following characteristics made patients more susceptible to pulmonary infection: age ≥ 70 years (HR=1.619, 95% CI 1.054-2.172), Charlson comorbidity index ≥ 2 points (HR=1.647, 95% CI 1.043-2.485), using of proton pump inhibitor ≥ 7 days (HR=1.725, 95% CI 1.214-2.738), and number of pressure ulcers ≥ 3 (HR=2.109, 95% CI 1.128-3.844). However, serum albumin concentration ≥35 g/L (HR=0.670, 95% CI 0.375-0.963) was a protective factor for pulmonary infections. The number of consistent pathogens cultivated from saliva, gastric juice and sputum simultaneously in NGT and PEG group was 35 strains (27.8%) and 8 strains (13.3%), respectively (P=0.029). The mortality of pulmonary infection was similar in the two groups (3.5% vs 4.3%, P=1.000), but the death due to pulmonary infection in the PEG group occur later (median time: 20 days vs 11 days, P=0.012). Conclusions: PEG feeding was a preferred nutrition way which could reduce the risk of pulmonary infection more effectively than NGT feeding which might favored a retrograde gastro-pulmonary route by which pathogens colonized in stomach migrated to respiratory tract. Patients with characteristics mentioned above had the susceptibility of pulmonary infection, thus risk assessment of pulmonary infection should be conducted before selecting the catheterization method.

[Surveillance of contamination level and antimicrobial resistance analysis of Salmonella on broiler carcasses after chilling in 4 poultry slaughterhouses of Henan Province].

Objective: Tests were carried out for obtaining contamination level and antimicrobial resistance of Salmonella on broiler carcasses after chilling in four poultry slaughterhouses in Henan. Methods: Totally, two hundred sixty nine broiler carcasses after chilling were collected in four slaughterhouses with the daily slaughter amount around 15 000 to 50 000. For qualitative analysis of Salmonella EFSA method was used and for quantitative analysis of Salmonella modified Rappaport-Vassiliadis most probable number (MSRV-MPN) method was used. All of the isolates were subjected to antimicrobial susceptibility testing of 8 antibiotics by minimum inhibitory concentration (MIC). Results: Overall, 48.7% (131/269) of the broiler carcasses after chilling were contaminated by Salmonella, and the average of contamination level is 1.32 most probable number MPN/g. Eight serotypes were detected. The dominant serotype is Salmonella enteritidis (93, 71.0%) followed by Salmonella Indiana (21, 16.0%). Only 2 (1.5%) Salmonella enteritidis strains were sensitive to all the tested antibiotics and the remaining 129 isolates were resistant to at least one kind of eight class antibiotics. Among them, resistant to NAL was the common (104, 79.4%) and 51 (38.9%) Salmonella isolates were multidrug-resistant. Conclusion: The contamination rate and multiple antimicrobial resistant of Salmonella on broiler carcasses after chilling from slaughterhouses was very serious, while the isolates contained various serotypes.

[Prevalence and antimicrobial susceptibility of Salmonella isolated from broiler whole production process in four provinces of China].

Objective: To determine the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler production process in 4 provinces of China. Methods: Using convenience sampling method, 238 sample sites from broiler whole production process were chosen in Henan, Jiangsu, Heilongjiang and Shandong provinces in 2012. A total of 11 592 samples were collected and detected to analyze prevalence baseline, including 2 090 samples from breeding chicken farms and hatcheries, 1 421 samples from broiler farms, 5 610 samples from slaughterhouses and 2 471 samples from distribution and retail stores. All Salmonella strains were isolated through selective enrichment, and were serotyped according to Kauffmann-White scheme. The antimicrobial susceptibilities of selected Salmonella strains were determined by the broth microdilution method and fourteen antimicrobial agents were examined. Results: During incubation course, the average prevalence of Salmonella was 5.5% in feces of breeding hens, feces of chicks, and hatching eggs, 123 Salmonella strains were isolated. During cultivation course, the prevalence of Salmonella was 8.0% in feces from broiler farms, soil, feed, and workers, 114 Salmonella strains were isolated. During slaughter course, the prevalence of Salmonella was 24.9% in swabs pre-slaughter, dressed broiler carcasses, pre-cooled broiler carcasses, water from precooling pool, cutter and chipping boards, frozen chicken portions, and workers, 1 438 Salmonella strains were isolated. During distribution and sale course, the prevalence of Salmonella was 20.9% in transport carts, frozen chicken portions, retail chicken portions and workers, 551 Salmonella strains were isolated. The dominant Salmonella serotypes were Salmonella Enteritidis (n=1 229) and Salmonella Indiana (n=621). Among 1 231 examined strains, 97.2% Salmonella isolates were resistant to at least one antimicrobial, 69.9% Salmonella strains were multi-drug resistant isolates. Conclusion: Our findings indicated that Salmonella contamination was common and serious in commercial broiler whole production process in China, especially in the course of defeathering, precooling and selling. The environment of broiler farm is the important source of Salmonella contamination. Additionally, antibiotic resistance of Salmonella was serious for common antimicrobials and multi-drug resistant strains existed widespread, which can pose potential risk on public health and clinical therapy.

[Clinical analysis of the double-wing flap for treatment of toe syndactyly].

Objective: To explore the clinical effect of double-wing flap for the treatment of toe syndactyly. Methods: Retrospective analysis of 47 patients (60 syndactyly toes) who underwent double-wing flap to reconstruct toe web space in orthopedics department of the Third Affiliated Hospital of Zhengzhou University from February 2010 to October 2017.There were 21 males and 26 females, with an average age of 18.9 months (range: 10-48 months). All patients were treated with zigzag incisions to separate the toe syndactylys without skin grafts.The condition of wound healing and appearance of toes were observed. Results: The average follow-up time was 62.3 months (range: 6 to 80 months). There were no complications such as hematoma, infection, flap necrosis and no flexion contracture and obvious scar hyperplasia in all the 47 cases, 4 of the 60 webs developed web creep.All webs had good appearance with 45 degrees inclination from the dorsal to the metatarsal side and had good flexion and abduction function. Conclusions: The double-wing flap is a simple and safe operation for toe syndactyly which has a good clinical effect.

[Research Progress of Age Estimation Based on Age-related Changes of Dentin-pulp Complex].

Age estimation is a hot and difficult issue in forensic practice. Teeth are the most solid organs in human body and can be kept in vitro for a long time. With age, the secondary dentin gradually generates and the volume of pulp cavity constantly decreases. Therefore, forensic dentists proposed that age-related changes of dentin-pulp complex could be used to estimate age, which has been widely applied in forensic practice over the years. Due to the development of imaging technology, a variety of methods have been advocated by forensic dentists to detect the age-related changes of dentin-pulp complex for age estimation. However, different methods have their own advantages and limitations, forensic scientists should combine the use of different methods for improving the accuracy of age estimation according to the actual situation. This paper reviews current research of age estimation based on dentin-pulp complex, so as to provide reference for related research.

Highly accurate fiber transfer delay measurement with large dynamic range.

A novel and efficient method for fiber transfer delay measurement is demonstrated. Fiber transfer delay measurement in time domain is converted into the frequency measurement of the modulation signal in frequency domain, accompany with a coarse and easy ambiguity resolving process. This method achieves a sub-picosecond resolution, with an accuracy of 1 picosecond, and a large dynamic range up to 50 km as well as no measurement dead zone.

A non-PCR SPR platform using RNase H to detect MicroRNA 29a-3p from throat swabs of human subjects with influenza A virus H1N1 infection.

As in all RNA viruses, influenza viruses change and mutate constantly because their RNA polymerase has no proofreading ability. This poses a serious threat to public health nowadays. In addition, traditional pathogen-based detection methods may not be able to report an infection from an unknown type or a subtype of virus if its nucleotide sequence is not known. Because of these factors, targeting host microRNA signatures may be an alternative to classify infections and distinguish types of pathogens as microRNAs are produced in humans shortly after infection. Although this approach is in its infant stage, there is an urgent need to develop a rapid reporter assay for microRNA for disease control and prevention. As a proof of concept, we report herein for the first time a non-PCR MARS (MicroRNA-RNase-SPR) assay to detect the microRNA miR-29a-3p from human subjects infected with influenza virus H1N1 by surface plasmon resonance (SPR). In our MARS assay, RNase H is employed to specifically hydrolyze the RNA probes immobilized on the gold surface where they hybridize with its cognate target cDNAs miR-29a-3p, where it was formed from reverse transcription with mature miR-29a-3p specific stem-looped primers. After the digestion of the RNA probe by RNase H, the intact cDNA was released from the RNA-DNA hybrid and bound to a new RNA probe for another enzymatic reaction cycle to amplify signals. With assay optimization, the detection limit of our MARS assay for miR-29a-3p was found to be 1 nM, and this new assay could be completed within 1 hour without thermal cycling. This non-PCR assay with high selectivity for mature microRNA provides a new platform for rapid disease diagnosis, quarantine and disease control.

DNA genetic artificial fish swarm constant modulus blind equalization algorithm and its application in medical image processing.

This study proposes use of the DNA genetic artificial fish swarm constant modulus blind equalization algorithm (DNA-G-AFS-CMBEA) to overcome the local convergence of the CMBEA. In this proposed algorithm, after the fusion of the fast convergence of the AFS algorithm and the global search capability of the DNA-G algorithm to drastically optimize the position vector of the artificial fish, the global optimal position vector is obtained and used as the initial optimal weight vector of the CMBEA. The result of application of this improved method in medical image processing demonstrates that the proposed algorithm outperforms the CMBEA and the AFS-CMBEA in removing the noise in a medical image and improving the peak signal to noise ratio.

Multi-modulus algorithm based on global artificial fish swarm intelligent optimization of DNA encoding sequences.

Aimed to address the defects of the large mean square error (MSE), and the slow convergence speed in equalizing the multi-modulus signals of the constant modulus algorithm (CMA), a multi-modulus algorithm (MMA) based on global artificial fish swarm (GAFS) intelligent optimization of DNA encoding sequences (GAFS-DNA-MMA) was proposed. To improve the convergence rate and reduce the MSE, this proposed algorithm adopted an encoding method based on DNA nucleotide chains to provide a possible solution to the problem. Furthermore, the GAFS algorithm, with its fast convergence and global search ability, was used to find the best sequence. The real and imaginary parts of the initial optimal weight vector of MMA were obtained through DNA coding of the best sequence. The simulation results show that the proposed algorithm has a faster convergence speed and smaller MSE in comparison with the CMA, the MMA, and the AFS-DNA-MMA.

[Analysis of whole-mouth taste function test results in 584 healthy adults].

Objective: To assess the taste function of healthy Chinese adults with the reliable whole-mouth taste test, and to analyze the correlation of taste function with age and gender. Methods: The clinical data of 584 participants reporting the normal sense of smell and taste from March 2019 to January 2020 in the Physical Examination Center of Beijing Anzhen Hospital were analyzed in the study, including 297 males and 287 females, aging (46.9±16.6) years. The subjects were divided into youth group (19-35 years old), middle aged group (36-50 years old), middle-elderly aged group (51-65 years old) and elderly group (66-80 years old). The taste test involved 5 tastants (sour, sweet, salty, umami and bitter) and 7 concentrations. The perception and recognition scores of five tastes were obtained through the whole-mouth taste test. SPSS 22.0 software was used for statistical analysis. Results: The intra-class correlation coefficients of the whole-mouth taste test were 0.751 to 0.828, which showed high test-retest reliability. The total score of perception and recognition of five tastes showed the significant negative correlation with age (r value was -0.49 and -0.44, respectively, both P<0.001). Compared with the other two groups, taste function of middle-elderly aged and elderly group decreased significantly (all P<0.001). There was no significant difference in total perception scores and total recognition scores between youth and middle aged group (all P>0.05). The perception scores and recognition scores of sour, salty, umami, bitter and total scores in females were higher than those in males (all P<0.05), but there was no significant difference in perception scores and recognition scores for sweet between them (P value was 0.584 and 0.223, respectively). Conclusions: The taste function is significantly negatively correlated with age. Except the sweet, females are more sensitive to the sour, salty, umami and bitter tastes than males.

[Evaluation of chemosensory function in patients with upper respiratory tract post-viral olfactory dysfunction].

Objective: To observe the changes of olfactory function, intranasal trigeminal nerve function and taste function in patients with upper respiratory tract post-viral olfactory dysfunction (PVOD), and to explore the correlation of chemosensory function. Methods: The clinical data of 42 patients with PVOD who visited to the Olfactory and Taste Center of Otorhinolaryngology Head and Neck Surgery Department of Beijing Anzhen Hospital from January to December of 2019 were analyzed retrospectively, including 20 males and 22 females, aging (48.86±11.47) years (x¯). Twenty subjects in normal control group were selected according to the sex ratio of PVOD patients. Sniffin' Sticks olfactory tests were performed on the subjects, including threshold test (T), discrimination test (D) and identification test (I), and the sum of the above three test scores was the TDI value. At the same time, olfactory event-related potentials (oERPs), trigeminal event-related potentials (tERPs) and taste function test were performed. According to the taste function test, the patients were divided into normal gustation (NG) group and gustatory dysfunction (GD) group. The results of olfaction, taste and intranasal trigeminal nerve function tests were compared among different groups, and the correlation analysis was carried out. SPSS statistical software was used for statistical analysis. Results: GD was present in 14 (33.3%) of 42 PVOD patients with a course of PVOD of 5 (3, 6) months (M (Q1, Q3)). The gustatory function of patients with PVOD was related to gender (r=0.565, P<0.001), smoking status (r=-0.512, P=0.001), duration (r=-0.357, P=0.020) and olfactory function (all P<0.05). The olfactory function of GD group was worse than that of NG group, and the differences of TDI value and T value between the two groups were statistically significant (10.25±4.58 vs 13.35±3.61, 1.54±0.66 vs 2.10±0.88, t value was 2.40 and 2.10 respectively, both P<0.05). The amplitudes of oERPs and tERPs were significantly lower in GD group than those in NG group (all P<0.05). Conclusion: In patients with PVOD, the subjective and objective olfactory function, intranasal trigeminal nerve function and taste function were decreased, and there was a correlation, suggesting that there was a synergistic effect between the chemosensory functions of PVOD patients.