Optimal Heat Exchanger Area Distribution and Low-Temperature Heat Sink Temperature for Power Optimization of an Endoreversible Space Carnot Cycle

Using finite-time thermodynamics, a model of an endoreversible Carnot cycle for a space power plant is established in this paper. The expressions of the cycle power output and thermal efficiency are derived. Using numerical calculations and taking the cycle power output as the optimization objective, the surface area distributions of three heat exchangers are optimized, and the maximum power output is obtained when the total heat transfer area of the three heat exchangers of the whole plant is fixed. Furthermore, the double-maximum power output is obtained by optimizing the temperature of a low-temperature heat sink. Finally, the influences of fixed plant parameters on the maximum power output performance are analyzed. The results show that there is an optimal temperature of the low-temperature heat sink and a couple of optimal area distributions that allow one to obtain the double-maximum power output. The results obtained have some guidelines for the design and optimization of actual space power plants.

Performance Analysis and Four-Objective Optimization of an Irreversible Rectangular Cycle

Based on the established model of the irreversible rectangular cycle in the previous literature, in this paper, finite time thermodynamics theory is applied to analyze the performance characteristics of an irreversible rectangular cycle by firstly taking power density and effective power as the objective functions. Then, four performance indicators of the cycle, that is, the thermal efficiency, dimensionless power output, dimensionless effective power, and dimensionless power density, are optimized with the cycle expansion ratio as the optimization variable by applying the nondominated sorting genetic algorithm II (NSGA-II) and considering four-objective, three-objective, and two-objective optimization combinations. Finally, optimal results are selected through three decision-making methods. The results show that although the efficiency of the irreversible rectangular cycle under the maximum power density point is less than that at the maximum power output point, the cycle under the maximum power density point can acquire a smaller size parameter. The efficiency at the maximum effective power point is always larger than that at the maximum power output point. When multi-objective optimization is performed on dimensionless power output, dimensionless effective power, and dimensionless power density, the deviation index obtained from the technique for order preference by similarity to an ideal solution (TOPSIS) decision-making method is the smallest value, which means the result is the best.

Performance Optimizations with Single-, Bi-, Tri-, and Quadru-Objective for Irreversible Diesel Cycle

Applying finite time thermodynamics theory and the non-dominated sorting genetic algorithm-II (NSGA-II), thermodynamic analysis and multi-objective optimization of an irreversible Diesel cycle are performed. Through numerical calculations, the impact of the cycle temperature ratio on the power density of the cycle is analyzed. The characteristic relationships among the cycle power density versus the compression ratio and thermal efficiency are obtained with three different loss issues. The thermal efficiency, the maximum specific volume (the size of the total volume of the cylinder), and the maximum pressure ratio are compared under the maximum power output and the maximum power density criteria. Using NSGA-II, single-, bi-, tri-, and quadru-objective optimizations are performed for an irreversible Diesel cycle by introducing dimensionless power output, thermal efficiency, dimensionless ecological function, and dimensionless power density as objectives, respectively. The optimal design plan is obtained by using three solution methods, that is, the linear programming technique for multidimensional analysis of preference (LINMAP), the technique for order preferences by similarity to ideal solution (TOPSIS), and Shannon entropy, to compare the results under different objective function combinations. The comparison results indicate that the deviation index of multi-objective optimization is small. When taking the dimensionless power output, dimensionless ecological function, and dimensionless power density as the objective function to perform tri-objective optimization, the LINMAP solution is used to obtain the minimum deviation index. The deviation index at this time is 0.1333, and the design scheme is closer to the ideal scheme.

Application of Maxillary Sinus Effusion Detection in Diagnosis of Drowning

Abstract

Objective To study the imaging characteristics of maxillary sinus effusion in drowned bodies, to explore its morphological characteristics and value in the diagnosis of the cause of death, and to provide objective evidence to support the study of virtual anatomy of drowning. Methods The 154 postmortem CT examination cases （31 cases of drowning, 123 cases of non-drowning） of Beijing Public Security Bureau Forensic Center in 2019 were collected. The bodies of all cases were scanned by multi-layer spiral CT before double-blind reading by clinical imaging experts. Maxillary sinus of corpses with maxillary sinus effusion in imaging findings was punctured. The detection rate of maxillary sinus effusion was calculated. The CT value and volume of maxillary sinus effusion were measured on 3D DICOM workstation. Results The detection rate of maxillary sinus effusion in the drowning was 100%, the shape was horizontal liquid level, the volume was 1.2-11.2 mL, the CT value was 6.08-19.02 Hu, with an average value of 12.85 Hu. The detection rate of maxillary sinus effusion in non-drowning was 19.51% （24/123）, the shape was wavy or irregular, and there were bubbles inside, the volume was 0.4-13.4 mL, the CT value was 23.68-77.75 Hu, with an average value of 42.08 Hu. The differences in CT value between the two groups had statistical significance. Conclusion The postmortem CT examination method can be used to observe the shape and measure the CT value of the maxillary sinus effusion in the bodies in water, which can be an auxiliary examination method for identification of drowning.

[Multicenter cross-sectional investigation on the cleaning status and influencing factors of skin cleaning outside the wound in adult trauma patients]

Objective: To investigate the status and influencing factors of skin cleaning outside wound (hereinafter referred to as skin) in adult trauma patients. Methods: A multicenter cross-sectional investigation was conducted. From September 1 to 30, 2020, a total of 952 adult trauma patients who met the inclusion criteria were admitted to wound care clinics or trauma surgery wards of 13 military or local Grade Ⅲ Level A hospitals, including the General Hospital of the Eastern Theater Command of People's Liberation Army and the Army Medical Center, etc. A self-designed questionnaire on cleaning status of skin in trauma patients was released through the "questionnaire star" website to investigate basic information such as gender, age, education level, living status, and self-care ability, trauma information such as cause of injury, wound duration, trauma site, trauma depth, wound pain, wound peculiar smell, and wound cleaning solution, and skin cleaning status after injury such as whether to clean or not, cleaning method, cleaning frequency, cleaning duration in each time, or reasons for not cleaning. The patients who cleaned skin regularly after injury were included in cleaning group, and the other patients were included in no cleaning group. The basic information, trauma information, and skin cleaning status after injury of patients in 2 groups were investigated. Data were statistically analyzed with chi-square test, and binary multivariate logistic regression analysis was performed on indicators with statistically significant differences between the two groups to screen the independent influencing factors of skin cleaning in trauma patients. Results: A total of 952 questionnaires were received, and the recovery rate was 100%. Three invalid questionnaires were eliminated, and 949 valid questionnaires were obtained, with an effective rate of 99.68%. In 949 patients, there were 461 (48.6%) males and 488 (51.4%) females, aged 18-100 (50±18) years. Most patients were less than 60 years old, lived with their families, and could take care of themselves completely. Nearly half of the patients were with junior high school or below education level. The main causes of injury were sharp cutting injury and falling injury, the wound duration was 2-365 days, most of the injured parts were limbs and trunk, the wound depth was mostly full-thickness injury, and most patients had wound-related pain and no peculiar smell and used 5 g/L iodophor to clean the wound. Totally 684 (72.1%) patients cleaned their skin after injury, mainly by scrubbing with warm water, the cleaning frequency was mainly once or twice a week, and the cleaning time was mainly 10 or 15 min for each time. Totally 265 (27.9%) patients didn't clean their skin after injury, and the main causes for not cleaning were following the doctor's advice, followed by worrying about wound infection and loss of self-care ability. There were significantly statistical differences in constituent ratios of education level, self-care ability, cause of injury, wound pain, and wound peculiar smell of patients in 2 groups (χ²=12.365, 24.519, 22.820, 9.572, 92.342, P<0.01). Education level, self-care ability, cause of injury, wound pain, and wound peculiar smell were potential influencing factors of skin cleaning in patients. Binary multivariate logistic regression analysis showed that self-care ability, wound pain, and wound peculiar smell were independent influencing factors of skin cleaning in patients (odds ratio=1.51, 0.52, 3.72, 95% confidence interval=1.08-2.12, 0.42-0.89, 2.66-5.22, P<0.05 or P<0.01). Conclusions: Self-care ability, wound pain, and wound peculiar smell are independent influencing factors of skin cleaning in adult trauma patients.

Evaluation of left ventricular systolic synchrony by peak strain dispersion in patients with rheumatoid arthritis

Objective

To investigate the clinical value of the peak strain dispersion (PSD) in evaluating left ventricular (LV) systolic synchrony in patients with rheumatoid arthritis (RA).

Methods

One hundred eleven patients with RA were divided into two groups according to their disease duration: <5 years (Group I, n = 60) and ≥5 years (Group II, n = 51). The control group comprised 57 healthy subjects without RA. All three groups were examined by transthoracic two-dimensional echocardiography. Traditional parameters were measured by conventional echocardiography. Two-dimensional speckle tracking imaging was used to analyze the PSD and LV global longitudinal strain (LVGLS). Related ultrasound and blood test results were analyzed and compared.

Results

The PSD gradually increased in the order of the control group, Group I, and Group II, and the difference among the groups was statistically significant. The LVGLS gradually decreased in the order of the control group, Group I, and Group II, and the difference among the groups was statistically significant. The PSD was negatively correlated with the LVGLS.

Conclusions

LV systolic synchrony in patients with RA gradually decreases as the disease course progresses. The PSD can be used as a new reliable index to evaluate LV systolic synchrony.

Invasive and in situ squamous cell carcinoma of the skin: a nationwide study in Iceland

BACKGROUND

The worldwide incidence of cutaneous squamous cell carcinoma (cSCC) is increasing.

OBJECTIVES

To evaluate the tumour burden of in situ and invasive cSCC in Iceland, where the population is exposed to limited ultraviolet radiation.

METHODS

This whole-population study used the Icelandic Cancer Registry, which contains records of all in situ and invasive cSCC cases from 1981 to 2017. Incidence of cSCC was evaluated according to age, anatomical location, residence and multiplicity, and trends were assessed using joinpoint analysis. Age-standardized rates (WSR) and age-specific incidence rates per 100 000 person-years were calculated, along with cumulative and lifetime risks.

RESULTS

Between 1981 and 2017, in situ cSCC WSR increased from 1·2 to 19·1 for men and from 2·0 to 22·3 for women. Invasive cSCC WSR rose from 4·6 to 14 for men and from 0·3 to 13·2 for women. The average number of in situ cSCC lesions was 1·71 per woman and 1·39 per man. Women developed more in situ cSCCs than invasive cSCCs in almost all anatomical locations, whereas men developed more invasive cSCCs, mostly on the head and neck. The rates of in situ cSCC were higher in Reykjavik compared with rural areas. Furthermore, women more commonly developed multiple in situ lesions. For lip cSCCs, invasive lesions occurred more frequently than in situ lesions among both sexes. Joinpoint analysis showed that in situ cSCC in women exhibited the most rapid incidence increase.

CONCLUSIONS

cSCC has become an increasingly significant public health problem in Iceland. Tanning bed use and travelling abroad may contribute to skin cancer development. Public health efforts are needed to stem the behaviours leading to this rapid rise in cSCC.

Racial and gender differences in the relationship between sarcopenia and bone mineral density among older adults

Both sarcopenia and low bone mineral density (BMD) have become public health concerns. We found that presarcopenic and/or sarcopenic individuals were more likely to have lower BMD. And this relationship has race and sex-specific discrepancy.

PURPOSE

The purpose of the study was to investigate the racial and gender differences in the relationship between sarcopenia and BMD among older adults.

METHODS

Totally, 5476 subjects (mean age = 65.7 ± 6.4) of non-Hispanic White (n = 3297), non-Hispanic Black (n = 1265), and non-Hispanic Asian (n = 914) were analyzed. Sarcopenia was defined according to the revised European consensus on definition and diagnosis of sarcopenia (EWGSOP2). General linear model and multivariable linear regression model were used to examine the relationship between sarcopenia and regional/whole body BMD stratified by race and sex. Adjustments were conducted for physiological, behavioral, and disease factors.

RESULTS

Comparing with normal older participants, presarcopenic and sarcopenic elderly were more likely to have lower BMD. Although the difference was not statistically significant in a few sub-groups, among the three racial groups, the strongest association between sarcopenia and BMD was found in non-Hispanic Black people, followed by non-Hispanic White people and non-Hispanic Asian people. In addition, significant differences of BMD across sarcopenia stages were found in more sub-groups in women than in men after adjusting for covariates.

CONCLUSIONS

In this older cohort, sarcopenia is significantly related to low regional/whole-body BMD, and these associations vary by race and sex. Consideration in race and sex is warranted when developing strategies to maintain or minimize BMD loss.

Modeling and Performance Optimization of an Irreversible Two-Stage Combined Thermal Brownian Heat Engine

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.

Forensic Progress on Death Following Carotid Sinus Inhibition

Abstract

Death after carotid sinus trauma is usually attributed to death from inhibition, a type of sudden death. Currently, the number of incidents is scarce, and related studies are few. Therefore, how to determine the involvement of carotid sinus and determine the role of diseases in the cause of death has always been a difficult point in forensic investigation. This article sorts out the research literature on carotid sinus related death at home and abroad in recent years, systematically reviews the anatomic structure of the carotid sinus nerve, the clinical epidemiology of carotid sinus syndrome, and the research on the death mechanism of carotid sinus injury at home and abroad in recent years, in order to provide references for forensic pathology research and prosecution.

ORAOV1-B Promotes OSCC Metastasis via the NF-κB-TNFα Loop

Metastasis, a powerful prognostic indicator of oral squamous cell carcinoma (OSCC), is chiefly responsible for poor cancer outcomes. Despite an increasing number of studies examining the mechanisms underlying poor outcomes, the development of potent strategies is hindered by insufficient characterization of the crucial regulators. Long noncoding RNAs (lncRNAs) have recently been gaining interest as significant modulators of OSCC metastasis; however, the detailed mechanisms underlying lncRNA-mediated OSCC metastasis remain relatively uncharacterized. Here, we identified a novel alternative splice variant of oral cancer overexpressed 1 (ORAOV1), named as ORAOV1-B, which was subsequently validated as an lncRNA and correlated with OSCC lymph node metastasis; significantly increased invasion and migration were observed in ORAOV1-B-overexpressing OSCC cells. RNA pulldown and mass spectrometry identified Hsp90 as a direct target of ORAOV1-B, and cDNA microarrays suggested TNFα as a potential downstream target of ORAOV1-B. ORAOV1-B was shown to directly bind to and stabilize Hsp90, which maintains the function of client proteins, receptor-interaction protein, and IκB kinase beta, thus activating the NF-κB pathway and inducing TNFα. Additionally, TNFα reciprocally enhanced p-NF-κB-p65 and the downstream epithelial-mesenchymal transition. ORAOV1-B effects were reversed by a TNFα inhibitor, demonstrating that TNFα is essential for ORAOV1-B-regulated metastatic ability. Consistent epithelial-mesenchymal transition in the ORAOV1-B group was demonstrated via an orthotopic model. In the metastatic model, ORAOV1-B significantly contributed to OSCC-related lung metastasis. In summary, the novel splice variant ORAOV1-B is an lncRNA, which significantly potentiates OSCC invasion and metastasis by binding to Hsp90 and activating the NF-κB-TNFα loop. These findings demonstrate the versatile role of ORAOV1 family members and the significance of genes located within 11q13 in promoting OSCC. ORAOV1-B might serve as an attractive OSCC metastasis intervention target.

Lrp6 Dynamic Expression in Tooth Development and Mutations in Oligodontia

Genes associated with the WNT pathway play an important role in the etiology of tooth agenesis. Low-density lipoprotein receptor-related protein 6 encoding gene (LRP6) is a recently defined gene that is associated with autosomal dominant inherited tooth agenesis. Here, we aimed to identify novel LRP6 mutations in patients with tooth agenesis and investigate the significance of Lrp6 during tooth development. Using whole-exome sequencing, we identified 4 novel LRP6 heterozygous mutations (c.2292G>A, c.195dup, c.1095dup, and c.1681C>T) in 4 of 77 oligodontia patients. Notably, a patient who carried a nonsense LRP6 mutation (c.2292G>A; p.W764*) presented a hypohidrotic ectodermal dysplasia phenotype. Preliminary functional studies, including bioinformatics analysis and TOP-/FOP-flash reporter assays, demonstrated that the activation of WNT/β-catenin signaling was compromised as a consequence of LRP6 mutations. RNAscope in situ hybridization revealed dynamic and special changes of Lrp6 expression during murine tooth development from E11.5 to E16.5. It was noteworthy that Lrp6 was specifically expressed in the epithelium at E11.5 to E13.5 but was expressed in both dental epithelium and dental papilla from E14.5 and persisted in both tissues at later stages. Our study broadens the mutation spectrum of human tooth agenesis and is the first to identify a LRP6 mutation in patients with hypohidrotic ectodermal dysplasia and reveal the dynamic expression pattern of Lrp6 during tooth development. Information from this study is conducive to understanding the functional significance of Lrp6 on the biological process of tooth development.

Mechanism of TonB-dependent transport system in Halomonas alkalicola CICC 11012s in response to alkaline stress

Halomonas alkalicola CICC 11012s can grow at pH 12.5, the highest pH at which the organisms in the genus Halomonas can grow. Genomic analysis reveals that H. alkalicola adapts to alkaline stress using a variety of adaptive strategies; however, the detailed mechanism for its growth at high-alkaline conditions has not been elucidated. Therefore, in this study, the adaptations of H. alkalicola in response to extreme alkaline stress were investigated. A sharp decrease of alkaliphilic tolerance was observed in mutants E. coli ΔEctonB and H. alkalicola ΔHatonB. Expressions of the gene clusters encoding TonB-dependent transport system and iron complex transport system in H. alkalicola grown under extreme alkaline conditions were markedly up-regulated. We then compared the intracellular ionic iron content and iron-chelating ability of mutant strain with those of wild-type strain to understand the influence of TonB-dependent transport system on the alkaline responses. The results indicated that the presence of TonB-dependent transport system increased the alkaline tolerance of H. alkalicola grown at high-alkaline conditions, but had no effects when the strain was grown at neutral pH and low-alkaline conditions. Meanwhile, the presence of this system increased the transport and accumulation of ionic irons to maintain intracellular metabolic homeostasis, which in turn could increase the tolerance of the strain to extreme alkaline conditions. Based on the results, we established a model representing the interactions between TonB-dependent transport system, alkaline tolerance, and intracellular ionic iron that could help deepen the understanding of the alkaline response mechanism of alkaliphilic bacteria.

Four-Objective Optimization of Irreversible Atkinson Cycle Based on NSGA-II

Variation trends of dimensionless power density (PD) with a compression ratio and thermal efficiency (TE) are discussed according to the irreversible Atkinson cycle (AC) model established in previous literature. Then, for the fixed cycle temperature ratio, the maximum specific volume ratios, the maximum pressure ratios, and the TEs corresponding to the maximum power output (PO) and the maximum PD are compared. Finally, multi-objective optimization (MOO) of cycle performance with dimensionless PO, TE, dimensionless PD, and dimensionless ecological function (EF) as the optimization objectives and compression ratio as the optimization variable are performed by applying the non-dominated sorting genetic algorithm-II (NSGA-II). The results show that there is an optimal compression ratio which will maximize the dimensionless PD. The relation curve of the dimensionless PD and compression ratio is a parabolic-like one, and the dimensionless PD and TE is a loop-shaped one. The AC engine has smaller size and higher TE under the maximum PD condition than those of under the maximum PO condition. With the increase of TE, the dimensionless PO will decrease, the dimensionless PD will increase, and the dimensionless EF will first increase and then decrease. There is no positive ideal point in Pareto frontier. The optimal solutions by using three decision-making methods are compared. This paper analyzes the performance of the PD of the AC with three losses, and performs MOO of dimensionless PO, TE, dimensionless PD, and dimensionless EF. The new conclusions obtained have theoretical guideline value for the optimal design of actual Atkinson heat engine.

The first two months epidimiological study of COVID-19, related public health preparedness, and response to the ongoing epidemic in Pakistan

As an underdeveloped country, the coronavirus disease 2019 (COVID-19) epidemic has posed a major risk to the health and economy of Pakistan. The SIR (susceptible-infected-recovered) model of epidemiologic analysis predicts that there should have been more cases since late March 2020 in Pakistan. We therefore sought to investigate COVID-19's prevalence and epidemiologic trends in Pakistan. Research for COVID-19 is still in its early stages, so data were collected from official websites and research journals, then analyzed for the disease's prevalence, epidemiology, mortality and recoveries. The results indicated that a rapid increase had indeed occurred in the number of COVID-19 infections in Pakistan, with the first case reported on 25 February, 2020. From 25 February 25 to April, 2020, COVID-19 infected 11,155 people in Pakistan, with 237 deaths (2.12%) and 2527 recoveries (19.96%). We found a statistically significant positive correlation between the prevalence of COVID-19 and the mortality ratio (r = 0.983, r 2 = 0.966; p ≤ 0.05). We concluded that proper management must be undertaken to improve the quarantine system, and the World Health Organization guidelines must be closely followed to cope with COVID-19. There is no vaccine for COVID-19, so antiviral drugs (interferon alfa, ribavirin) may be useful to prevent COVID-19; however, severe control measures implemented in China have significantly mitigated the spread of COVID-19. Suspected and confirmed cases must be treated in separate rooms. Staying home and social distancing are the safe way to proceed.

Performance Optimization of a Condenser in Ocean Thermal Energy Conversion (OTEC) System Based on Constructal Theory and a Multi-Objective Genetic Algorithm

Constructal optimization of a plate condenser with fixed heat transfer rate and effective volume in ocean thermal energy conversion (OTEC) system is performed based on constructal theory. Optimizations of entropy generation rate ( S ˙ g ) in heat transfer process and total pumping power ( P sum ) due to friction loss are two conflicting objectives for a plate condenser. With the conventional optimization method, the plate condenser is designed by taking a composite function (CF) considering both S ˙ g and P sum as optimization objectives, and employing effective length, width, and effective number of heat transfer plates as design variables. Effects of structural parameters of the plate condenser and weighting coefficient of CF on design results are investigated. With a multi-objective genetic algorithm, the plate condenser is designed by simultaneously optimizing S ˙ g and P sum , and the Pareto optimal set is obtained. The results demonstrate that CFs after primary and twice-constructal optimizations are respectively reduced by 7.8% and 9.9% compared with the initial CF, and the effective volume of the plate condenser has a positive impact on the twice minimum CF. Furthermore, the Pareto optimal set can provide better selections for performance optimizations of plate condensers.

Comparison of Meconium Microbiome in Dizygotic and Monozygotic Twins Born by Caesarean Section (CS)

The early-life microbiota triggers life-long effects on physiological functions and health disorders. Previous studies in adult twins or animal models have revealed associations between host genetics and the harmonious microbiota. However, such associations may be obscured by the fact that each intra-pair of twins will continually encounter various environmental factors as they grow up. Here, we collected the meconium samples from nineteen dizygotic pairs (DZ, n = 38) and nine monozygotic pairs (MZ, n = 18) with cesarean delivery, and 16S rRNA gene sequencing was performed to profile the microbiome at birth. Diversity analysis showed that alpha diversity was not significantly different between two groups, whereas beta diversity of MZ twins was significantly lower than that of either DZ twins or unrelated individuals (i.e., randomly selected individual pairs of non-twinship) (p < 0.05). Two groups had very similar microbial classifications but different relative abundances of certain taxa including more Firmicutes (p = 0.05, Wilcoxon test) at the phylum level and lower abundances of five genera (p < 0.05) in DZ group compared to MZ group, including Rheinheimera, Proteus, SMB53, Sphingobium, and Megamonas. Co-occurrence analysis in each group showed slightly more complicated microbial interactions in DZ than MZ twins, although 22 shared bacterial genera co-existed in two groups, with both Rheinheimera and Megamonas having different centralities in their respective co-occurrence networks. Mean intra-class correlation coefficient (ICC) were also significantly higher for MZ (0.312) compared to DZ twins (0.138) (p < 0.05). The predicted microbial gene functions related to carbohydrate were higher in DZ group, whereas folding, sorting, degradation, cell motility pathways and energy metabolism were markedly over-represented in the microbiota of MZ group. In summary, our study uncovered that microbial diversity and components of the meconium microbiome between DZ and MZ twins were partially consistent with that in singleton neonates by cesarean delivery, but several distinctions related to the heritability supported genetic contributions to intestinal microbiome in early life.

[Health economic evidence for colorectal cancer screening programs in China: an update from 2009-2018]

Objective: This study was to systematically update the economic evaluation evidence of colorectal cancer screening in mainland China. Methods: Based on a systematic review published in 2015, we expanded the scope of retrieval database (PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP, CBM) and extended it to December 2018. Focusing on the evidence for nearly 10 years (2009-2018), basic characteristics and main results were extracted. Costs were discounted to 2017 using the consumer price index of medical and health care being provided to the residents, and the ratio of incremental cost-effectiveness ratio (ICER) to per capita GDP in corresponding years were calculated. Results: A total of 12 articles (8 new ones) were included, of which 9 were population-based (all cross-sectional studies) and 3 were model-based. Most of the initial screening age was 40 years (7 articles), and most of the frequency was once in a lifetime (11 articles). Technologies used for primary screening included: questionnaire assessment, immunological fecal occult blood test (iFOBT) and endoscopy. The most commonly used indicator was the cost per colorectal cancer detected, and the median (range) of the 20 screening schemes was 52 307 Chinese Yuan (12 967-3 769 801, n=20). The cost per adenoma detected was 9 220 Yuan (1 859-40 535, n=10). In 3 articles, the cost per life year saved (compared with noscreening) was mentioned and the ratio of ICER to GDP was 0.673 (-0.013-2.459, n=11), which was considered by WHO as "very cost-effective" ; The range of ratios overlapped greatly among different technologies and screening frequencies, but the initial age for screening seemed more cost-effective at the age of 50 years (0.002, -0.013-0.015, n=3), than at the 40 year-olds (0.781, 0.321-2.459, n=8). Conclusions: Results from the population-based studies showed that the cost per adenoma detected was only 1/6 of the cost per colorectal cancer detected, and limited ICER evidence suggested that screening for colorectal cancer was generally cost-effective in Chinese population. Despite the inconclusiveness of the optimal screening technology, the findings suggested that the initial screening might be more cost-effective at older age. No high-level evidence such as randomized controlled trial evaluation was found.