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The blow-off limits of methane and hydrogen-mixed gas on the Sydney inhomogeneous inflow jet burner were calculated and studied by large eddy simulation. The GRI 3.0 detailed reaction mechanism, 28-step and 19-step methane simplified reaction mechanisms were used to calculate the laminar premixed flames under the condition of different hydrogen-mixed fuel gases, which demonstrates the good performance of the 19-step simplified mechanism. A dynamic thickening flame combustion model was combined with the 19-step reaction mechanism to compute the Sydney partially premixed jet flame burner with a hydrogen-mixed gas (the volume ratio of V(H2):V(CH4):V(CO):V(CO2) = 0.2:0.2:0.27:0.33). The blow-off limits in FA and FJ layouts of hydrogen-mixed gas are 90 m/s and 109 m/s, while for pure methane flames are 74 m/s and 128 m/s, respectively. The difference of blow-off limits between the two fuels is related to the inhomogeneity of fuel and air mixing in different layouts. This study shows that the combustion stability can be improved by optimizing the inlet layout and mixing process of fuel gas and air.

The second goal of Sustainable Development Goals (SDGs) (SDG‐2: zero hunger), which integrates food security, nutrition, and sustainable agriculture, is the common aim of human beings. Assessment of food security performance is the premise of understanding the global food security to tailor strategies toward SDG‐2. This study quantitatively assesses the food security of 93 countries using a multiple‐dimensional indicator system (MDIS) with five dimensions (i.e., availability, access, utilization, stability, and other) consisting of 34 indicators using the data for the years 2015, 2016, 2017, and 2018. The results show imbalance in global food security, which is generally high in Europe, Oceania, and North America, fair in East Asia and South America, and low in Africa and South Asia. In the dimensions, countries with low availability are mainly owing to the bad performances of indicators related to energy, protein, and meat supply; the low utilization is expressed in the number of obese adults, stunted children, prevalence of anemia of women, obese adults and overweight children; the low food access showed in the low GDP per capita and rail line density; and the low‐stability countries mainly have the high food import dependency and low political stability. Policy implications include promoting the adoption of agricultural technologies to boost food production, implementing inclusive finance among vulnerable groups to enhance health equality, developing national economy and transport systems to increase access to food, and encouraging local food reserves and calling for world peace to stable food supply. This study provides national governments and international organizations with a new MDIS, status quo, and possible solutions to eliminating hunger. [ABSTRACT FROM AUTHOR]

In the research of porous media and the interior of microelectronic devices, fluids frequently shuttle among pores and wall cracks, therefore it is of great significance to explore the influence of media wall on fluid flow and heat transfer. In this paper, CFD-DSMC coupled iterative algorithm is first used in the research of the flow and heat transfer of gas near the wall in the porous media, which simplified into the flow and heat transfer in micron-scale tube with smooth and rough wall conditions. It is found that compared with the pure CFD method, the velocity field obtained by the coupled method is quite different in the region close to the wall, and this will affect the flow field in the mainstream region, that is, with the higher roughness of the wall, the velocity in the central region will be smaller. There is no significant difference in the temperature distribution in the microtube before and after coupling, but the temperature in the mainstream decreases with the increase of the roughness of the wall. In addition, the temperature jump was found from some of the coupling results close to the wall. The results will contribute to a deeper understanding of the influence of rough surfaces on gas flow and heat transfer near the wall, and provide guidance for the regulation of flow and heat transfer in porous media. [ABSTRACT FROM AUTHOR]

To explore the metabolic profiles in the aqueous humor (AH) of patients with congenital ectopia lentis (CEL). We conducted a comprehensive analysis of the metabolites of AH samples of patients with CEL (n = 22) and age-matched patients (n = 22) with congenital cataract by ultra-high performance liquid chromatography tandem-mass spectrometry. The metabolomic characteristics were visualized by principal component analysis, orthogonal partial least squares discriminant analysis and heat map. The levels of the differential metabolites were also compared between CEL patients with and without FBN1 mutations. Pathway enrichment analysis was performed by using Kyoto Encyclopedia of Genes and Genomes. Receiver operating characteristic analysis was performed to select potential biomarkers. There were 175 differential metabolites identified between the two groups. Eight metabolites were found to be potential biomarkers in AH of CEL patients. The CEL group showed a significant increase in α-ketoglutarate and decrease in citrate, suggesting that the tricarboxylic acid (TCA) cycle was disturbed. l-proline, prolyl-hydroxyproline, and l-histidine were reduced, which prompted enhanced degradation of microfibrils and collagen. Insidious retinal nerve damage was implied because N-Acetyl-aspartylglutamic acid and N-Acetyl-l-aspartic acid were found to be significantly increased. Pathway enrichment analysis indicated that disturbances in amino acid metabolism and carbohydrate metabolism were the key processes in the pathogenesis of CEL and that TCA cycle disorder may be the driving force behind disease occurrence. These data reveal the characteristics in the metabolomic profiles of the AH of CEL patients, which help provide insights into the pathogenesis of this rare disease. [ABSTRACT FROM AUTHOR]

In order to solve the trim problem of computational fluid dynamics (CFD) simulation for rigid coaxial rotor, a hybrid trim model coupling CFD method and high-efficiency model (blade element theory) is established. In the trim process, the Jacobian matrix is solved by the high-efficiency model, while the CFD solver is only called for rotor performances modifying after each trimming step. The influences of pseudo time step, number of CFD revolution, and inflow model are investigated. Validation cases of AH-1G and Harrington-1 rotors are carried out, and good agreements are obtained. Results show that the trim efficiency can be significantly improved by saving the calculation of CFD for the Jacobian matrix. The trim accuracy is guaranteed by the correction operation with the CFD solver at each step. Moreover, as only time-averaged rotor performances are useful for trim, the efficiency can be further improved by adopting appropriately small pseudo time step and CFD revolution. The hybrid trim model has high robustness. The accuracy of inflow model for the coaxial rotor affects the convergence speed, but the final convergence can be achieved generally. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients with poliomyelitis often have abnormalities in the femur and the conventional plant matching degree of fracture is low. There are few reports on individualized treatment for severe deformity of femoral shaft fracture in poliomyelitis. OBJECTIVE: To summarize the clinical features of femoral shaft fracture in poliomyelitis and discuss the operative outcome of 3D printing pre-operation assisted with custom-made plate. METHODS: From May 2015 to May 2018, data of 19 patients with poliomyelitis surgically treated with 3D printing pre-operation assisted with custom-made plate were retrospectively analyzed. There were 11 males and 8 females with an average age of 52.5 years (range, 38-62 years). There were 7 cases on the left side, and 12 cases on the right side. According to AO/OTA classification of femoral shaft fracture, there were type A1 in 6 cases, type A2 in 3 cases, type A3 in 1 case, type B1 in 4 cases, type B2 in 4 cases and type C1 in 1 case. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. The 3D printed 1:1 femur model and custom-made plate were designed. Operation was simulated in vitro in femoral model. The placement of the plate was identified. The direction and length of the screws were measured and recorded. The final internal fixation of fracture was performed according to the pre-operation results. Hip and knee functions in the affected limb were assessed based on Harris evaluation criterion and hospital for special surgery knee score evaluation criterion. RESULTS AND CONCLUSION: (1) All19 patients were followed up for 12-18 months. Bone healing was obtained in all fractures, with a healing time of 5-12 months, averaging 6.6 months. (2) Harris score was (84.95±5.18) before injury, and (84.42±4.83) 1 year after operation. Hospital for special surgery knee score was (84.53±4.36) before injury, and (83.63±3.90) 1 year after operation. Statistical analysis showed no statistical difference between the two groups before and after the injury (P > 0.05). (3) All patients had no internal fixation loosening or fracture. One patient had delayed bone healing and healed after iliac bone grafting. One patient developed wound infection after surgery, and received adequate drainage. Wound was healed after intravenous application of sensitive antibiotics. (4) Patients with poliomyelitis often have abnormalities in the femur with varying degrees of osteoporosis. For femoral shaft fractures that cannot be fixed with conventional internal fixation, 3D printing pre-operation combined with custom-made steel plate provides a new choice for the treatment of femoral shaft fractures in poliomyelitis. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the frequency of LTBP2 mutations and to elaborate on LTBP2-related clinical phenotypes in a Chinese congenital ectopia lentis (CEL) cohort., Methods: In total, 145 Chinese probands with CEL were recruited for this study and underwent ocular and systemic examinations. Whole-exome sequencing was used to identify mutations, and Sanger sequencing and bioinformatics analysis were further performed to verify pathogenic mutations., Results: Overall, biallelic mutations in LTBP2 involving eight novel mutations (c.4370-7_4370-9delTCT, c.4370-5C>G, c.3452G>A, c.2253delG, c.4114T>C, c.1251G>A, c.4760G>A, and c.620G>A) were identified in four CEL probands (4/145, 2.76%). Patients with LTBP2 mutations were characterized by a megalocornea, spherophakia, high myopia, and glaucoma instead of a flat cornea, high corneal astigmatism, cardiovascular and skeletal abnormalities that were reported in other gene mutations. A novel homozygous frameshift mutation was detected, and this type of mutation was found to cause more complicated ocular symptoms than others, ranging from the anterior segment to the fundus., Conclusion: This study reported the mutation frequency of the LTBP2 gene in a Chinese CEL cohort and provided novel insight into LTBP2-related genotype-phenotype associations in CEL., (Copyright © 2023 Molecular Vision.)