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Buffer energy absorbing structures have very high use value in daily life, industrial production, aerospace and other fields. Cylindrical shells are used as a highly efficient buffer and energy absorbing structure due to their own structure and good mechanical properties. Taylor impact experiments were conducted on three types of structural cylindrical shells (non grooved, inner grooved, and outer grooved) and numerical model was also established to study and analyze the dynamic response characteristics of the three types of structural cylindrical shells. Finally, the deformation mechanism of the cylindrical shell was analyzed theoretically to explore the impact of grooving treatment on the deformation of the cylindrical shell. The results show that with the increase of impact velocity, the length of the cylindrical shells of the three structures decreased, and the diameter of the impact end and the maximum diameter increased. Each of the three specimens had a convergence velocity(convergence velocity: The impact end diameter of cylindrical shell is the initial impact velocity at the maximum diameter), that is, when the impact velocity was greater than or equal to the convergence velocity, its maximum diameter was equal to the diameter of the impact end. When the impact velocity exceeded a certain value, the deformation modes of the three types of cylindrical shells changed. The comparison of experimental and simulation results proved the effectiveness of the numerical model. The maximum stress was always above the impact end face. It was concluded from the theoretical analysis Due to the stress concentration at the groove, the stress distribution and internal stress distribution of the cylindrical shell were affected, which in turn affected the deformation and energy absorption capacity of the cylindrical shell. At the same impact velocity, the outer grooved cylindrical shell has the shortest buffer time and the BW specimen had the most gentle buffer curve before 35μs. [ABSTRACT FROM AUTHOR]

Purpose: Chlamydia trachomatis (C. trachomatis) is associated with several gynecological tumors; yet its prognostic role in breast cancer remains unclear. Thus, we investigated the prognostic role of anti-C. trachomatis immunoglobulin G (IgG) in breast cancer patients and the modification effects of pro-inflammatory cytokines. Methods: The serum levels of C. trachomatis IgG and four pro-inflammatory cytokines were measured. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), including product terms to assess the modification effects of pro-inflammatory cytokines on the association between C. trachomatis IgG and breast cancer prognosis. Results: From 2008 to 2018, 1121 breast cancer patients were recruited and followed up until December 31, 2021, with a median follow-up time of 63.91 months (interquartile range: 39.16– 90.08 months). Patients positive for C. trachomatis IgG showed HRs of 1.09 (95% CI, 0.67– 1.78) for overall survival (OS) and 1.24 (0.87– 1.78) for progression-free survival (PFS), compared to those who were negative. These associations became statistically significant in women aged 50 years or younger (HR=1.43, 95% CI=0.79– 2.58 for OS; HR=1.79, 95% CI=1.16– 2.77 for PFS). Positive C. trachomatis IgG serology was associated with adverse prognostic effects among patients with higher levels of pro-inflammatory cytokines (IL-6, TNF-α, IL-8, and IL-1β), but with favorable prognostic effects for those with low levels. These interactions were particularly significant in those aged 50 years or younger. Conclusion: In breast cancer patients younger than 50 years of age or with higher levels of pro-inflammatory cytokines, C. trachomatis infection appeared to have a negative prognostic impact. These findings highlight the significance of C. trachomatis in predicting prognosis and personalized therapy for breast cancer patients. [ABSTRACT FROM AUTHOR]

Multifunctional response materials showing potential applications in the fields of sensors and optoelectronic devices have attracted widespread attention. However, the synergistic effect of multiple properties in a molecular compound remains a challenge. Herein, we report a multifunctional response material (TPA)2MnBr4 (1), (TPA+ = tetrapropylamine), which undergoes a reversible structural phase transition at 403/370 K. The phase transition further induces a switchable dielectric anomaly and luminescence response. Moreover, the reversible conversion of the χMT value and fluorescence emission was also observed near the phase transition temperature. This work provides a new impetus for the development of Mn(II)-based multifunctional response materials. [ABSTRACT FROM AUTHOR]

Abstract Background Threonine is an essential amino acid that is extensively used in livestock industry as feed supplement due to its pronounced effect in improving the growth performance of animals. Application of genetically engineered bacteria for amino acid production has its share of controversies after eosinophils myalgia syndrome outbreak in 1980s. This has urged for continuous search for a food grade producer as a safer alternative for industrial amino acid production. Lactic acid bacteria (LAB) appear as an exceptional candidate owing to their non-pathogenic nature and reputation of Generally Recognized as Safe (GRAS) status. Recently, we have identified a LAB, Pediococcus pentosaceus TL-3, isolated from Malaysian food as a potential threonine producer. Thus, the objective of this study was to enhance the threonine production by P. pentosaceus TL-3 via optimized medium developed by using Plackett–Burman design (PBD) and central composite design (CCD). Results Molasses, meat extract, (NH4)2SO4, and MnSO4 were identified as the main medium components for threonine production by P. pentosaceus TL-3. The optimum concentration of molasses, meat extract, (NH4)2SO4 and MnSO4 were found to be 30.79 g/L, 25.30 g/L, 8.59 g/L, and 0.098 g/L respectively based on model obtained in CCD with a predicted net threonine production of 123.07 mg/L. The net threonine production by P. pentosaceus TL-3 in the optimized medium was enhanced approximately 2 folds compared to the control. Conclusions This study has revealed the potential of P. pentosaceus TL-3 as a safer alternative to produce threonine. Additionally, the current study has identified the key medium components affecting the production of threonine by P. pentosaceus TL-3, followed by optimization of their concentrations by means of statistical approach. The findings of this study could act as a guideline for the future exploration of amino acid production by LAB.

Abstract Background Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets. However, the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA. Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes. Hence, the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements. Results All the studied LAB isolates were versatile extracellular protease producers, whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5, pH 6.5, pH 8) using qualitative and quantitative proteolytic assays. The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14, while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5. As for the results of AA production conducted in de Man, Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system, all LAB isolates were capable of producing an array of AA. Generally, Pediococcus sp. showed greater ability for AA production as compared to Lactobacillus sp. Moreover, the studied LAB were able to produce a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. P. pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively. However, L. plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h, while P. acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity. Conclusion All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. Despite AA production was strain dependent, the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.