Search

Drying is one of the most important steps in tobacco processing because it determines the color, taste, and micronutrients in tobacco. The loading density and the arrangement of tobacco leaves in the drying chamber affect the temperature and humidity distribution of the air, thereby affecting the drying quality. In this paper, three drying cases with different tobacco weights were studied by computational fluid dynamics (CFD) simulation as well as experimental. The results show that when the loading density of the tobacco drying chamber increases, the local resistance of tobacco leaves increases sharply, and the velocity difference and temperature difference of the air in the tobacco drying chamber increases. The maximum temperature difference in the highest loading density reaches 10 K. The uneven temperature distribution of the air reduces the quality of the dried tobacco.

Additional file 2: Table S1A. Clinical characteristics of patients and healthy controls in the discovery cohort. Table S1B. Clinical characteristics of patients and healthy controls in the validation cohort. Table S2. Gene panel for targeted sequencing. Table S3. Frequencies of mutations of difference sources in 55 HCC patients.

Additional file 1: Fig. S1. Study design chart. The discovery cohort consists of 55 patients with stage I, II and IIIA HCC and 55 healthy volunteers. Ultra-deep sequencing using a panel of the 13 genes found most often mutated among PwHCC were performed on WBC gDNA, FFPE-tumor tissue gDNA and plasma cell-free DNA to identify TDMs and the challenges in classifying the two groups of patients. Mutation fragment length profiles were used as input features to build a machine learning model. The model's performance was subsequently validated in an independent cohort of 55 HCC patients and 53 healthy individuals recruited from a different site. Figure S2. Comparison of on target rate and depth coverage between cfDNA and paired WBC gDNA sequencing. (A) and (B) On target rate (A) and mean depth coverage (B) of paired liquid biopsy cfDNA and WBC gDNA samples from 55 HCC patients in the discovery cohort. (C) Bar graph showing the amount of cfDNA (ng per ml) of plasma from HCC and healthy control samples. ns: not significant, Mann–Whitney U test. Fig. S3. Tumor-derived mutations in plasma samples of PwHCC overlapped with mutations detected in plasma of healthy participants. (A) Oncoprint plots of distributions of TDMs in 55 healthy individuals. Each row represents a TDM with mutation labeled on the right side and left side shows the occurrences of each mutation. Each column represents a patient. (B) Percentages of mutations shared between liquid biopsies and paired WBCs (LB-share-WBC, blue) and mutations uniquely found in liquid biopsy (LB-unique-variants, orange) for each patient after implementing our statistical model. Fig. S4. PwHCC patients displayed cfDNA fragment length profiles distinct from healthy individuals. (A) Length distribution of cfDNA fragments in plasma samples of 55 PwHCC and 55 healthy individuals. (B) The mean ratio of short (≤ 150 bp) to long (> 150bp) fragments across 22 chromosomes at 5Mb resolution for 55 PwHCC and 55 healthy individuals. Fig. S5. Distribution of fragment length of sequencing reads carrying LB-unique mutations (ALT) in all 55 PwHCC (A) and 55 healthy individuals (B), as compared to their corresponding reference reads (REF) in the discovery cohort. Fig. S6. Graphic explanation of three features generated from analyzing fragment length distribution of LB-unique mutations. (A) Feature 1: The fraction of short-to-long reads that carry LB-unique mutations compared to their corresponding reference reads (RF) in PwHCC (left) and healthy controls (right). (B) Feature 2: Analysis of fragment length distribution of all LB-unique fragments enriched in specific regions (e.g., 110-135 bp). PHRED-scaled p-value obtained from Fisher's exact test used to compare the distribution of ALT-fragments in selected regions. (C) Feature 3: The probability of observing an ALT-fragment of size s (dot points) in all ALT fragments by proportions was calculated (λ) and the sum of λ(s) over a sliding and non-overlapping window of 10 consecutive values of s was computed to yield a 15-dimensional feature vector.

Dissertation, RWTH Aachen University, 2021; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen (2021). = Dissertation, RWTH Aachen University, 2021, This dissertation is devoted to the proof of convergence of a variational time discretization proposed in [1]. Starting from the variational time discretization, we apply the well-known compensated compactness framework to prove strong convergence of constructed solutions to the p-system instead of the isentropic Euler equations. The reason behind this alteration is that the variational time discretization has a Lagrangian nature: Fluid states are constructed based on a transport map, which is obtained by solving a minimization problem at each time step. These transport maps update the position of all fluid particles after each iteration, thus illustrate their trajectories. Once we obtain the strong convergence for the p-system, the interchangeability between the two systems following from continuity arguments will lead to the desired strong convergence of the scheme for isentropic Euler equations., Published by RWTH Aachen University, Aachen

Despite the discovery of the tuberculosis bacillus >100 years ago and the availability of effective drugs for >50 years, there remain a number of formidable challenges for controlling Mycobacterium tuberculosis (Mtb) infection [1]. The development of a more-effective vaccine is a high worldwide priority and depends on a thorough understanding of the host response to infection. Furthermore, tuberculosis (TB) causes different types of human disease, including localized pulmonary disease, extrapulmonary disease—such as meningitis—and miliary or disseminated disease. It is not known at present which host genetic, environmental, and bacterial virulence factors influence the different clinical presentations of TB. Tuberculous meningitis (TBM) is an especially devastating form of TB that causes death or severe neurological defici in more than one-half of persons affected [2]. Advances in genomic technology and immunology are creating new opportunities to understand the influence of human genetic variation on the pathophysiological characteristics of TB. The molecular mechanisms that influence the development of a protective immune response to Mtb are only beginning to be elucidated. A series of studies with different methodologies over the course of the past 50 years have indicated that host genetics strongly influence susceptibility to tuberculosis [3-11]. Major susceptibility loci from whole-genome methods have not yet been conclusively identified which suggests that the genetic control of susceptibility to TB is polygenic. Candidate gene-association studies of critical host response genes have successfully identified some of the genes involved in susceptibility to TB. Using candidate gene approaches, we and others have recently discovered mutations and polymorphisms in Toll-like receptor (TLR)–pathway genes that affect host susceptibility to infection [12-15]. The discovery of TLRs precipitated a major advance in understanding the molecular mechanisms of both pathogen recognition and inflammation by the innate immune system [16-18]. Human TLRs are a family of 10 proteins that differentially recognize pathogen-associated molecular patterns (PAMPs) and initiate signaling pathways that lead to the activation of the innate immune response, cytokine production, and formation of the adaptive immune response. Mycobacteria are initially recognized by TLR1, −2, −4, and −6, which, in turn, interact with the adaptor proteins MyD88 and Toll-interleukin 1 receptor (TIR) domain containing adaptor protein (TIRAP; also known as Mal) to activate macrophages and dendritic cells [19-25]. TIRAP mediates signals from these TLRs through its TIR domain, which forms a homotypic interaction with the TIR domain of the TLR [26-29]. It is not presently known whether polymorphisms in TIRAP influence susceptibility to any infection. Because of the central role that adaptor proteins play in mediating signals from TLRs that recognize Mtb, we hypothesized that polymorphisms in TIRAP are associated with susceptibility to TB. In the present article, we report the association of a TIRAP single-nucleotide polymorphism (SNP) with susceptibility to TBM and demonstrate that this polymorphism is associated with a decreased whole-blood cytokine response. To our knowledge, this is the firs reported association of a TIRAP SNP with any infection, which suggests that variants of TIRAP influence important differences in host susceptibility to TB.

We found a high transfer ratio of anti-nontyphoidal Salmonella (NTS) antibodies from mothers to infants. Furthermore, despite a high seroincidence of NTS in infants, maternally acquired antibodies provided protection from seroconversion. Therefore, we propose prenatal immunization against NTS as a possible strategy for protecting infants from NTS disease., Background Nontyphoidal Salmonella (NTS) organisms are a major cause of gastroenteritis and bacteremia, but little is known about maternally acquired immunity and natural exposure in infant populations residing in areas where NTS disease is highly endemic. Methods We recruited 503 pregnant mothers and their infants (following delivery) from urban areas in Vietnam and followed infants until they were 1 year old. Exposure to the dominant NTS serovars, Salmonella enterica serovars Typhimurium and Enteritidis, were assessed using lipopolysaccharide (LPS) O antigen–specific antibodies. Antibody dynamics, the role of maternally acquired antibodies, and NTS seroincidence rates were modeled using multivariate linear risk factor models and generalized additive mixed-effect models. Results Transplacental transfer of NTS LPS–specific maternal antibodies to infants was highly efficient. Waning of transplacentally acquired NTS LPS–specific antibodies at 4 months of age left infants susceptible to Salmonella organisms, after which they began to seroconvert. High seroincidences of S. Typhimurium and S. Enteritidis LPS were observed, and infants born with higher anti-LPS titers had greater plasma bactericidal activity and longer protection from seroconversion. Conclusions Although Vietnamese infants have extensive exposure to NTS, maternally acquired antibodies appear to play a protective role against NTS infections during early infancy. These findings suggest that prenatal immunization may be an appropriate strategy to protect vulnerable infants from NTS disease.

Background BRAF is a localised gene in chromosome 7q34. The BRAF V600E gene mutation as a necessary starting condition for the transition from benign to malignant lesions is well worth monitoring for prognosis of colorectal lesions. Aims Describe histopathology and BRAF mutations in colorectal polyps. Methods A total of 81 patients with non-cancerous colon polyps were randomly assigned to the study. Patients with endoscopic polyps, specimens for histopathology then classify groups: neoplastic, hyperplastic, hamartomatous, inflammatory polyp. The immunohistochemical analysis of these samples then determined the BRAF mutation. Results The percentage of male is 69.1%, female is 30.9%. The mean age was 52.06±12.83. Adenoma polyps accounted for 63%. Serrated polyps were 35.8. Juvenile polyps had a ratio of 1.2%. Mild dysplasia is 58%, moderate dysplasia is 6.2%, severe dysplasia is 3.7%. BRAF gene mutation accounted for 22.2%, pervasive sample was highest with 19.8%, surface and bottom samples were 1.2%. BRAF gene mutations were detected in 12.5% hyperplastic polyp, 33.3% sessile serrated polyps, 100% traditional serrated adenomas, p=0.01. A total of 73/81 specimens were found to be inflammatory in which the BRAF mutation level +was detected in 86.7% of samples with inflammation, the level of ++BRAF gene mutation detected in 33.3% of samples have inflammation, p=0.003. Conclusions BRAF gene mutations in serrated polyps were higher in hyperplastic polyps. This explains the notion that progression from hyperplastic polyps to serrated adenomas with BRAF mutations can lead to colorectal cancer.

Background Co-results of endoscopy and BRAF mutation, P53, Ki67 immunoexpression increase sensitivity and specificity in the early diagnosis of colorectal cancer. Aims To analyse the relationship between endoscopic characteristics and BRAF mutation, P53, Ki67 immunoexpression in patients with a colorectal polyp. Methods A total of 81 non-cancerous colorectal polyp patients were randomised to the study. Patients undergoing endoscopic, histopathological, and immunohistochemical analyses. Results Gender ratio: male 69.1%, female 30.9%. Highest age group 41–60 was 58%. There are a total of 175 polyps, an average number per patient 2.16±1.14. The proportion of multiple polyp patients was 61.7%, single polyp 38.3%. Sessile polyp was highest: 38.3%. The size of polyps 2 cm with only 7.4%. Colon polyps accounted for 67.9%, rectal 32.1%. BRAF mutation in single polyp accounted for 22.8%, multiple polyps 22%. BRAF mutation in flat-elevated polyp were lowest with 20%, pedunculated polyps had the highest rate of 26.9%. Mutation of BRAF polyp size >2 cm accounted for 50% as the highest. P53 expression was similar in the single and multiple polyp. P53 expression level +++in pedunculated polyp with 57.7%, subpedunculated 57.1%, sessile 32.3%. In terms of size, 100% polyps>2 cm express P53, p=0.03. Ki67 expression was similar in the single and multiple polyp. Polyp size >2 cm accounted for the highest Ki67 expression rate of 66.6%. Pedunculated polyp had the highest rate of Ki67 expression in the dysplasia of level +++with 42.3%, subpedunculated and sessile polyp 16.1%, p=0.04. Conclusions P53 immunoexpression are usually manifested in large pedunculated and subpedunculated polyps. Ki67 immunoexpression in the dysplasia area, manifested in pedunculated and subpedunculated polyps.

BACKGROUND To evaluate the safety and immunogenicity of the thiomersal-free (TF) and thiomersal-containing (TC) formulations of Hepavax-Gene in healthy Vietnamese neonates. METHODS A single-blind, randomized, controlled study in Ho Chi Minh City, Vietnam. Healthy infants, born after a normal gestational period (37-42 weeks) to hepatitis B surface antigen-negative mothers, participated in the study. Subjects were randomly allocated in a 1:1 ratio to receive either Hepavax-Gene TC or Hepavax-Gene TF using a standard 0-1-6-month administration schedule. Postvaccination blood samples were taken at months 1, 6 and 7. Parents/legal guardians recorded solicited local and systemic adverse events up to 4 weeks after each vaccination. RESULTS Very high proportions of subjects were seroprotected. Seroprotection rates at 1, 6 and 7 months were all above 95% using a 10 IU/L cutoff, and were mostly above 90% using a 100 IU/L cutoff. Seroprotection rates between the 2 formulations were equivalent within a 5% margin for either cutoff titer both after 6 and 7 months. There were no significant differences in the number of adverse events reported between the 2 formulations. Safety results were in line with previous reports for Hepavax-Gene. Both formulations of Hepavax-Gene were well tolerated. There were no local adverse events reported in the TF group. No serious adverse events were reported during the study. CONCLUSIONS The thiomersal-free formulation of Hepavax-Gene was noninferior to the thiomersal-containing formulation of Hepavax-Gene in terms of immunogenicity. There was evidence that the thiomersal-free vaccine was associated with fewer local adverse events.

Highlights • The diarrhoeal disease burden in a large, prospective infant cohort in Vietnam is defined. • Minimum incidence of clinic-based diarrhoea in infants: 271/1000 infant-years. • Rotavirus was most commonly identified, followed by norovirus and bacterial pathogens. • Frequent repeat infections with the same pathogen within 1 year. • Inclusion of rotavirus in the immunization schedule for Vietnam is warranted., Summary Objectives Previous studies indicate a high burden of diarrhoeal disease in Vietnamese children, however longitudinal community-based data on burden and aetiology are limited. The findings from a large, prospective cohort study of diarrhoeal disease in infants in southern Vietnam are presented herein. Methods Infants were enrolled at birth in urban Ho Chi Minh City and a semi-rural district in southern Vietnam, and followed for 12 months (n = 6706). Diarrhoeal illness episodes were identified through clinic-based passive surveillance, hospital admissions, and self-reports. Results The minimum incidence of diarrhoeal illness in the first year of life was 271/1000 infant-years of observation for the whole cohort. Rotavirus was the most commonly detected pathogen (50% of positive samples), followed by norovirus (24%), Campylobacter (20%), Salmonella (18%), and Shigella (16%). Repeat infections were identified in 9% of infants infected with rotavirus, norovirus, Shigella, or Campylobacter, and 13% of those with Salmonella infections. Conclusions The minimum incidence of diarrhoeal disease in infants in both urban and semi-rural settings in southern Vietnam was quantified prospectively. A large proportion of laboratory-diagnosed disease was caused by rotavirus and norovirus. These data highlight the unmet need for a rotavirus vaccine in Vietnam and provide evidence of the previously unrecognized burden of norovirus in infants.

Coating, as a form of tool edge preparation, changes the properties, geometry and roughness of the active parts of tool inserts. The performance of both uncoated and coated ceramics was tested in machining tests and the results were related to the tool edge and the machined surface as well as cost indices. The presented results show that tool edge preparation by coating does affect forces, tool wear and the machined surface, while friction force from scratch tests and the coating thickness and its hardness have been identified as being relevant to the results of machining tests. The relationship between the thickness of the surface layer and residual stress at the surface due to coating has been evaluated. Though the tool life of coated ceramics is shorter than that of cubic boron nitride, tool edge preparation by coating contributes to the reduction in machining costs due to the application of higher cutting speeds.

A mathematical model is developed to represent an idealized system of a shared fish stock associated with different exclusive economic zones. We apply such model on small pelagic fisheries shared between Southern Morocco, Mauritania and the Senegambia. The complete model is a set of six ordinary differential equations describing the time evolution of the fish biomass and the fishing effort in the three zones. The fish species targeted as small pelagics could be consid- ered to perform quick displacement between the different zones, in comparison to their growth and harvesting. We take advantage of the two time scales to obtain a reduced model governing the total fish biomass of the system and fishing efforts in each zone. We study existence and stability of equilibrium points of the reduced model. The simulations show that as a result of competition between fisheries per zone there can only be one winner in the general case. Nevertheless there is also an arising case that allows an operational management of shared fisheries by acting on the cost of fishing unit effort, indeed we found that a large number of equilibrium exist. From this last case the initial distribution of fishing effort strongly impact the optimal equilibrium that can be reached. Lastly the model report that the country with the highest carrying capacity density may get less landings when collaborating with other countries than if it minimise its fishing costs. Such findings should allows regional fisheries organizations to get potential new ways for neighbouring fish stock management plan.

BACKGROUND: Shigella spp. are one of the most common causes of paediatric dysentery globally, responsible for a substantial proportion of diarrhoeal disease morbidity and mortality, particularly in industrialising regions. Alarming levels of antimicrobial resistance are now reported in S. flexneri and S. sonnei, hampering treatment options. Little is known, however, about the burden of infection and disease due to Shigella spp. in the community. METHODS/DESIGN: In order to estimate the incidence of this bacterial infection in the community in Ho Chi Minh City, Vietnam we have designed a longitudinal cohort to follow up approximately 700 children aged 12-60 months for two years with active and passive surveillance for diarrhoeal disease. Children will be seen at 6 month intervals for health checks where blood and stool samples will be collected. Families will also be contacted every two weeks for information on presence of diarrhoea in the child. Upon report of a diarrhoeal disease episode, study nurses will either travel to the family home to perform an evaluation or the family will attend a study hospital at a reduced cost, where a stool sample will also be collected. Case report forms collected at this time will detail information regarding disease history, risk factors and presence of disease in the household.Outcomes will include (i) age-specific incidence of Shigella spp. and other agents of diarrhoeal disease in the community, (ii) risk factors for identified aetiologies, (iii) rates of seroconversion to a host of gastrointestinal pathogens in the first few years of life. Further work regarding the longitudinal immune response to a variety of Shigella antigens, host genetics and candidate vaccine/diagnostic proteins will also be conducted. DISCUSSION: This is the largest longitudinal cohort with active surveillance designed specifically to investigate Shigella infection and disease. The study is strengthened by the active surveillance component, which will likely capture a substantial proportion of episodes not normally identified through passive or hospital-based surveillance. It is hoped that information from this study will aid in the design and implementation of Shigella vaccine trials in the future.

Understanding the host genetic susceptibility to typhoid fever may provide a better understanding of pathogenesis and help in the development of new therapeutics and vaccines. Here we determine the genetic variation within the human TLR4 gene encoding the principal receptor for bacterial endotoxin recognition in typhoid fever patients. It is possible that genetic variants of TLR4 could detrimentally affect the innate immune response against S. typhi infection. Mutation detection and genotyping of TLR4 was performed on DNA from 414 Vietnamese typhoid fever patients and 372 population controls. dHPLC detected a total of 10 polymorphisms within the upstream and exonic regions of TLR4, of which 7 are novel. Two SNPs, T4025A and C4215G, were more frequent in typhoid cases than in controls however due to their low allele frequencies they showed borderline significance (T4025A: OR 1.9, 95%Cl 0.9-4.3, P 0.07 and C4215G: OR 6.7, 95%Cl 0.8-307, P 0.04). Six missense mutations were identified, with 5/6 positioned in the ectoplasmic domain. Four missense mutations and one promoter SNP (A-271G) were only present in typhoid cases, albeit at low allele frequencies. Here we determined the extent of genetic variation within TLR4 in a Vietnamese population and suggest that TLR4 may be involved in defense against typhoid fever in this population. © 2009 Hue et al.

In this paper, we study a predator–prey model which has one prey and two predators with Beddington–DeAngelis functional responses. Firstly, we establish a set of sufficient conditions for the permanence and extinction of species. Secondly, the periodicity of positive solutions is studied. Thirdly, by using Liapunov functions and the continuation theorem in coincidence degree theory, we show the global asymptotic stability of such solutions. Finally, we give some numerical examples to illustrate the behavior of the model.

AIM: To compare the mortality morbidity of emergency and elective cesarean section with vaginal delivery among Asian teaching hospitals. METHODS: Hospital based prospective study at 12 centers of 9 countries. RESULTS: 12 591 vaginal deliveries 3062 elective and 4328 emergency cesarean section were followed up to 5 days postpartum. Maternal deaths (95% CI) per 1000 births among vaginal deliveries being 0.47 (0.17 1.03) was not significantly different from 0.31 (0.01 1.73) of elective cesarean section and both rates were significantly lower than 2.87 (1.53 4.91) per 1000 births of emergency section. The vaginal delivery group had significantly lower incidences of all major complication except significantly higher chance of secondary operations and non-significantly different risk for endometritis. Corresponding neonatal mortality per 1000 deliveries among the three groups were 7 (5.6 8.6) 2.2 (0.9 4.6) and 12.4 (9.3 16.2) (P < 0.001). Vaginal delivery also had higher rates of severe asphyxia and palsy than elective cesarean section. CONCLUSION: Maternal complications were increased by cesarean delivery but elective section may reduce neonatal complication.

Dengue hemorrhagic fever can occur in primary dengue virus (DENV) infection of infants. The decay of maternally derived DENV immunoglobulin (Ig) G and the incidence of DENV infection were determined in a prospectively studied cohort of 1244 Vietnamese infants. Higher concentrations of total IgG and DENV-reactive IgG were found in cord plasma relative to maternal plasma. Maternally derived DENV-neutralizing and E protein–reactive IgG titers declined to below measurable levels in >90% of infants by 6 months of age. In contrast, IgG reactive with whole DENV virions persisted until 12 months of age in 20% of infants. Serological surveillance identified 10 infants with asymptomatic DENV infection for an incidence of 1.7 cases per 100 person-years. DENV-neutralizing antibodies remained measurable for ⩾1 year after infection. These results suggest that whereas DENV infection in infants is frequently subclinical, there is a window between 4 and 12 months of age where virion-binding but nonneutralizing IgG could facilitate antibody-dependent enhancement