A statistically self-consistent fatigue damage accumulation model including load sequence effects under spectrum loading

A probabilistic methodology is proposed to evaluate fatigue damage accumulation and fatigue lives of specimens under variable amplitude loading. With probabilistic modifications in the present model, the calculative consistency is achieved between fatigue damage and fatigue life. The load sequence effects on fatigue damage accumulation are properly accounted for variable amplitude loading. The developed damage model overcomes the inherent deficiencies in the linear damage accumulation rule, but still preserves its simplicity for engineering application. Based on the Monte Carlo sampling method, numerical verification of this model is conducted under two kinds of spectrum loading. The predicted probabilistic distributions of fatigue lives are validated by fatigue tests on Al-alloy straight lugs.&nbsp

Behaviour and constitutive modelling of ductile damage of Ti-6Al-1.5Cr-2.5Mo-0.5Fe-0.3Si alloy under hot tensile deformation

In this paper, the flow softening and ductile damage of TC6 alloy were investigated using a uniaxial hot tensile test with deformation temperatures of 910 °C∼970 °C and strain rates of 0.01 s−1∼10 s−1. Scanning electron microscopy (SEM) was performed on the deformed specimens to reveal the damage mechanism. The results showed that the flow stress rapidly increases to a peak at a tiny strain, followed by a significant decrease due to flow softening and ductile damage. The ductile damage of the studied TC6 alloy can be ascribe to the nucleation, growth and coalescence of microdefects, and the microvoids preferentially nucleate at the interface of the alpha phase and beta matrix due to the inconsistent strain. Then, a set of unified viscoplastic constitutive equations including flow softening and ductile damage mechanisms was developed and determined, and this set of equations was verified by the experimental flow stress, which indicated the reliability of the prediction. Furthermore, the predicted normalized dislocation density and the adiabatic temperature rise increase with decreasing temperature and increasing strain rate. The predicted damage components show that the microdefects mainly nucleate in the initial stage, but then primarily grow and link together with continuing deformation

Mature cystic extragonadal teratoma in Douglas’ pouch: Case report and literature review

Teratomas often occur in the gonads, while Extragonadal mature cystic teratomas are reported occasionally, with the most common site being the omentum. Teratoma in the Douglas sac is extremely rare. we report a rare case of mature cystic Teratoma in the Douglas sac in a 71-year-old woman who underwent laparoscopic surgery. A cyst with a diameter of approximately 6 cm from Douglas was found during surgery, and the mass was separated from both ovaries. Microscopically, the cyst was a mature cystic teratoma that did not originate from the ovary

Evaluation of a Novel Biphasic Culture Medium for Recovery of Mycobacteria: A Multi-Center Study

on L-J slants. Automated liquid culture systems are expensive. A low-cost culturing medium capable of rapidly indicating the presence of mycobacteria is needed. The aim of this study was to develop and evaluate a novel biphasic culture medium for the recovery of mycobacteria from clinical sputum specimens from suspected pulmonary tuberculosis patients.<0.001).

A Novel Recombinant Peste des Petits Ruminants-Canine Adenovirus Vaccine Elicits Long-Lasting Neutralizing Antibody Response against PPR in Goats

BACKGROUND: Peste des petits ruminants (PPR) is a highly contagious infectious disease of goats, sheep and small wild ruminant species with high morbidity and mortality rates. The Peste des petits ruminants virus (PPRV) expresses a hemagglutinin (H) glycoprotein on its outer envelope that is crucial for viral attachment to host cells and represents a key antigen for inducing the host immune response. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether H can be exploited to generate an effective PPRV vaccine, a replication-competent recombinant canine adenovirus type-2 (CAV-2) expressing the H gene of PPRV (China/Tibet strain) was constructed by the in vitro ligation method. The H expression cassette, including the human cytomegalovirus (hCMV) promoter/enhancer and the BGH early mRNA polyadenylation signal, was inserted into the SspI site of the E3 region, which is not essential for proliferation of CAV-2. Infectious recombinant rCAV-2-PPRV-H virus was generated in transfected MDCK cells and used to immunize goats. All vaccinated animals produced antibodies upon primary injection that were effective in neutralizing PPRV in vitro. Higher antibody titer was obtained following booster inoculation, and the antibody was detectable in goats for at least seven months. No serious recombinant virus-related adverse effect was observed in immunized animals and no adenovirus could be isolated from the urine or feces of vaccinated animals. Results showed that the recombinant virus was safe and could stimulate a long-lasting immune response in goats. CONCLUSIONS/SIGNIFICANCE: This strategy not only provides an effective PPR vaccine candidate for goats but may be a valuable mean by which to differentiate infected from vaccinated animals (the so-called DIVA approach)

Evaluation of Carbon Emission and Carbon Contribution Capacity Based on the Beijing–Tianjin–Hebei Region of China

In 2020, during the 75th United Nations General Assembly, China proposed the goal of “achieving a carbon peak by 2030 and achieving carbon neutrality by 2060”. The Beijing–Tianjin–Hebei region is the largest carbon emission metropolitan area in China. Its energy consumption and carbon emission status means the Beijing–Tianjin–Hebei region shoulders the important task of low-carbon transformation. Only by achieving a “carbon peak” and “carbon neutrality” can the economy of the Beijing–Tianjin–Hebei region be sustainable. Based on this, we analyzed and comprehensively evaluated the complete ability of the Beijing–Tianjin–Hebei region to achieve carbon neutrality in 2008–2020, that is, carbon achievement ability, status, and intensity of energy consumption and carbon emissions based on the CRITIC weighting method. The results show that the energy consumption and carbon emission capacity of the Beijing–Tianjin–Hebei region have basically formed a step difference. On this basis, the evaluation of carbon contribution capacity also shows that Hebei Province, as a weak link in the coordinated development of the Beijing–Tianjin–Hebei region, bears the main responsibility of improving carbon contribution capacity and thus achieving the goal of carbon neutrality. This research study suggests that intra-regional cooperation should be strengthened to achieve coordinated development. At the end of the paper, policy suggestions for regional cooperation are given from four aspects: government, industry, low-carbon technology, and regional carbon sinks

Structural Response of the Metro Tunnel under Local Dynamic Water Environment in Loess Strata

The reasons, prevention, and control of loess disaster are of great concern in practice. In recent years, Xi’an city, China, has taken the leadership in large-scale construction of subway lines in the loess strata. To study the structural response of the tunnel in loess region under local hydrodynamic environment, an experimental testing in 1g as well as a numerical simulation were performed, in which the achieved results were verified and were found to be in good agreement. Furthermore, the results showed that when the water outlet point is above the lining, the overall stress of the lining is “peanut shell,” as the water pressure of the outlet point decreases, the tensile stress of the top and bottom of the lining increases, while the compressive stress on both sides decreases; the channel form of the flow to the lining changes with the variation of the position of the water outlet point. It is worth mentioning that in the process of water gushing, the closer to the water source, the greater surface subsidence is, and there is a positive correlation between water pressure and surface subsidence. This study is of significant benchmark for the construction, maintenance, and prevention of tunnel in loess strata under the influence of water environment

A New Technology for Utilization of Biomass Hydrolysis Residual Humins for Acetic Acid Production

Humins are a major byproduct formed from acid-catalyzed biomass hydrolysis and are usually considered as a low-value material. In this work, humins were completely degraded by a two-step technology, involving alkaline-catalytic hydrothermal treatment followed by wet oxidation. Using this technology, humins were converted to value-added acetic acid for first time. The highest acetic acid yield of 25.6% on a carbon basis or 37.2% on a mass basis was obtained with a purity of 46.2% based on the organic carbon in the aqueous product. This high-efficiency recovery of acetic acid is a new method for the effective utilization of humins, which is an important finding for biorefineries

Beneficial Effects of Theaflavins on Metabolic Syndrome: From Molecular Evidence to Gut Microbiome

In recent years, many natural foods and herbs rich in phytochemicals have been proposed as health supplements for patients with metabolic syndrome (MetS). Theaflavins (TFs) are a polyphenol hydroxyl substance with the structure of diphenol ketone, and they have the potential to prevent and treat a wide range of MetS. However, the stability and bioavailability of TFs are poor. TFs have the marvelous ability to alleviate MetS through antiobesity and lipid-lowering (AMPK-FoxO3A-MnSOD, PPAR, AMPK, PI3K/Akt), hypoglycemic (IRS-1/Akt/GLUT4, Ca2+/CaMKK2-AMPK, SGLT1), and uric-acid-lowering (XO, GLUT9, OAT) effects, and the modulation of the gut microbiota (increasing beneficial gut microbiota such as Akkermansia and Prevotella). This paper summarizes and updates the bioavailability of TFs, and the available signaling pathways and molecular evidence on the functionalities of TFs against metabolic abnormalities in vitro and in vivo, representing a promising opportunity to prevent MetS in the future with the utilization of TFs

Effects of antimicrobial peptide and tributyrin on fecal microflora and blood indices of female calves

Abstract This study evaluated the effects of antimicrobial peptide (AMP) and tributyrin (TB) on dairy calves in terms of growth performance, immunity, oxidative stress, and intestinal microflora. A total of 40 female calves were divided into four treatment groups (n = 10): basal diet +0.015% essential oil, basal diet +0.03% AMP, basal diet +0.15% TB, and basal diet +0.03% AMP + 0.15% TB. AMP and TB supplementation increased the average daily gain (ADG) and weaning weight, while reducing diarrhea occurrence. Additionally, AMP and TB supplementation reduced the levels of reactive oxygen species (ROS) and malonaldehyde (MDA), while increasing superoxide dismutase (SOD) levels and serum immunoglobulin M (IgM) levels. However, the combined use of AMP and TB did not significantly affect the average daily feed intake, ADG, weaning weight, or diarrhea incidence but decreased ROS levels, while increasing SOD levels as well as MDA and IgM levels. Moreover, AMP and TG supplementation increased the relative abundance of several beneficial fiber‐ and mucin‐degrading bacteria in the gut, in contrast to combined AMP and TB supplementation. The 16S rRNA results showed that AMP supplementation significantly increased the relative abundance of Rikenellaceae_RC9_gut_group, Ruminococcaceae_UCG‐014 and [Eubacterium]_coprostanoligenes group (p < .01), and significantly decreased the relative abundance of Ruminococcaceae_UCG‐005 and Christensenellaceae_R‐7_group (p < .01). The TB supplementation significantly increased the abundances of Rikenellaceae_RC9_gut_group and Ruminococcaceae_UCG‐005 (p < .01), and significantly decreased the relative abundances of Ruminococcaceae_UCG‐014, [Eubacterium]_coprostanoligenes group and Christensenellaceae_R‐7_group (p < .01). The combined use of AMP and TB significantly increased the relative abundance of Rikenellaceae_RC9_gut_group and Bacteroides (p < .01), and significantly decreased the relative abundance of Ruminococcaceae_UCG‐014, [Eubacterium]_coprostanoligenes group and Christensenellaceae_R‐7_group (p < .01). In summary, diets supplemented with either AMP or TB improved the intestinal microflora, growth performance, and health of weaned calves, but combined use was detrimental to calf performance