A Study on the Explicit Expression of Critical Stress and Euler Stress and its Application

Both the tangent modulus theory and the double modulus theory are classical theories which can be applied to the elastic-plastic stability analysis of columns. In the traditional tangent modulus theory, numerous iterations are required to calculate the critical buckling stress and this makes the method very time-consuming. In this paper, an explicit formula for establishing a direct correlation between the critical stress and the Euler stress has been proposed to reduce trial calculations. This formula can be applied to spherical shells by simplifying their stiffened plates to the form of beams on elastic foundations. The explicit expressions of both modulus theories can be used to calculate the ultimate strength of a spherical shell under pressure. The results from the proposed expression are compared with experimental results and other numerical results

Association of tea and its extracts with colorectal adenomas: meta-analysis and systematic review

BackgroundThere are many studies on the association of tea and its extracts with colorectal adenomas, but the results have varied. The study aims to investigate the effect of tea and its extracts on colorectal adenomas using meta analysis and systematic review.MethodsLiterature was obtained through PubMed, Cochrane Library, Embase and Chinese BioMedical Literature Service System since the establishment of the database until April 31, 2023. Search terms include adenomas, polyps, colorectal, rectal, rectum, tea, epigallocatechin, drinking and beverages. Meta-regression analysis was used to infer the source of heterogeneity. Heterogeneity was assessed using I2 statistics and Q test. The effect measures were odds ratio (OR) and 95% confidence interval (95% CI). Stata17.0 software was used for data processing.ResultsThe findings indicated that study design (t = 0.78, P = 0.454), types of tea intake (t = 1.35, P = 0.205), occurrences (t = -0.19, P = 0.852), regions (t = 1.13, P = 0.281) and grades of adenomas (t = 0.06, P = 0.952) were statistical homogeneity. Tea and its extracts were negatively correlated with the risk of colorectal adenomas (OR = 0.81, 95% CI: 0.66–0.98). No publication bias was found in this study (t = -0.22, P = 0.828) and the results are robust.ConclusionThis study suggests that tea and its extracts have a certain protective effect on colorectal adenomas, which provides scientific evidence for preventive strategies for colorectal adenomas. As for the causal relationship between tea and its extracts on colorectal adenomas, further prospective studies are needed

Optimal Regimens and Cutoff Evaluation of Tildipirosin Against Pasteurella multocida

Pasteurella multocida (PM) can invade the upper respiratory tract of the body and cause death and high morbidity. Tildipirosin, a new 16-membered-ring macrolide antimicrobial, has been recommended for the treatment of respiratory diseases. The objective of this research was to improve the dose regimes of tildipirosin to PM for reducing the macrolides resistance development with the pharmacokinetic/pharmacodynamic (PK/PD) modeling approach and to establish an alternate cutoff for tildipirosin against PM. A single dose (4 mg/kg body weight) of tildipirosin was administered via intramuscular (i.m.) and intravenous (i.v.) injection to the pigs. The minimum inhibitory concentration (MIC) values of clinical isolates (112) were measured in the range of 0.0625–32 μg/ml, and the MIC50 and MIC90 values were 0.5 and 2 μg/ml, respectively. The MIC of the selected PM04 was 2 and 0.5 μg/ml in the tryptic soy broth (TSB) and serum, respectively. The main pharmacokinetic (PK) parameters including the area under the curve at 24 h (AUC24 h), AUC, terminal half-life (T1/2), the time to peak concentration (Tmax), peak concentration (Cmax), relative total systemic clearance (CLb), and the last mean residence time (MRTlast) were calculated to be 7.10, 7.94 μg∗h/ml, 24.02, NA h, NA μg/ml, 0.46 L/h∗kg, 8.06 h and 3.94, 6.79 μg∗h/ml, 44.04, 0.25 h, 0.98 μg/ml, 0.43 L/h∗kg, 22.85 h after i.v. and i.m. induction, respectively. Moreover, the bioavailability of i.m. route was 85.5%, and the unbinding of tildipirosin to serum protein was 78%. The parameters AUC24 h/MIC in serum for bacteriostatic, bactericidal, and elimination activities were calculated as 18.91, 29.13, and 34.03 h based on the inhibitory sigmoid Emax modeling. According to the Monte Carlo simulation, the optimum doses for bacteriostatic, bactericidal, and elimination activities were 6.10, 9.41, and 10.96 mg/kg for 50% target and 7.86, 12.17, and 14.57 mg/kg for 90% target, respectively. The epidemiological cutoff value (ECV) was calculated to be 4 μg/ml which could cover 95% wild-type clinical isolates distribution. The PK-PD cutoff (COPD) was analyzed to be 0.25 μg/ml in vitro for tildipirosin against PM based on the Monte Carlo simulation. Compared with these two cutoff values, the finial susceptible breakpoint was defined as 4 μg/ml. The data presented now provides the optimal regimens (12.17 mg/kg) and susceptible breakpoint (4 μg/ml) for clinical use, but these predicted data should be validated in the clinical practice

Genotyping and biofilm formation of Mycoplasma hyopneumoniae and their association with virulence

Mycoplasma hyopneumoniae, the causative agent of swine respiratory disease, demonstrates differences in virulence. However, factors associated with this variation remain unknown. We herein evaluated the association between differences in virulence and genotypes as well as phenotype (i.e., biofilm formation ability). Strains 168 L, RM48, XLW-2, and J show low virulence and strains 232, 7448, 7422, 168, NJ, and LH show high virulence, as determined through animal challenge experiments, complemented with in vitro tracheal mucosa infection tests. These 10 strains with known virulence were then subjected to classification via multilocus sequence typing (MLST) with three housekeeping genes, P146-based genotyping, and multilocus variable-number tandem-repeat analysis (MLVA) of 13 loci. MLST and P146-based genotyping identified 168, 168 L, NJ, and RM48 as the same type and clustered them in a single branch. MLVA assigned a different sequence type to each strain. Simpson’s index of diversity indicates a higher discriminatory ability for MLVA. However, no statistically significant correlation was found between genotypes and virulence. Furthermore, we investigated the correlation between virulence and biofilm formation ability. The strains showing high virulence demonstrate strong biofilm formation ability, while attenuated strains show low biofilm formation ability. Pearson correlation analysis revealed a significant positive correlation between biofilm formation ability and virulence. To conclude, there was no association between virulence and our genotyping data, but virulence was found to be significantly associated with the biofilm formation ability of M. hyopneumoniae

Additive-free synthesis of 3D porous V2O5 hierarchical microspheres with enhanced lithium storage properties

A facile synthesis of novel 3D porous V2O5 hierarchical microspheres has been developed, based on an additive-free solvothermal method and subsequent calcination. Due to their unique structure, these V2O5 microspheres display a very stable capacity retention of 130 mA h g (1) over 100 cycles at a current rate of 0.5 C, and show excellent rate capability with a capacity of 105 mA h g (1) even at the 30 C rate. The good electrochemical performance suggests that this unique hierarchical V2O5 material could be a promising candidate as a cathode material for lithium-ion batteries

Performance Evaluation of Pilot-scale Hybrid Anaerobic Baffled Reactor (HABR) to Process Dyeing Wastewater Based on Grey Relational Analysis

A pilot-scale six-compartment hybrid anaerobic baffled reactor (HABR) with effective volume of 18 m3 was used to treat dyeing wastewater. The HABR system was able to treat the wastewater efficiently after FeSO4 pretreatment, as indicated by removal efficiencies of 33.7% for chemical oxygen demand (COD), 39.9% for suspended solid (SS), and 22.5% for sulfate (SO42−) during steadily operational period. Gas chromatography–mass spectrometry (GC-MS) showed that the concentrations of alkanes, amides, organic acids, ketones, phenols, and esters were much lower in the effluent than those in the influent; many high-molecular-weight compounds such as cyclanes, quinolines, and phenols were successfully transformed to low-molecular-weight ones. As illustrated from the results of generalized grey relational analysis (GGRA), COD removal efficiency was more closely associated with flow rate, organic loading rate (OLR), water temperature, and influent SS among the whole selected possible factors. Based on the overall treating effectiveness and the GGRA study, the optimized operation strategy of the dyeing wastewater treatment by HABR was obtained as the hydraulic retention time (HRT) of 12 h for steady-state operation with an up-flow velocity of 1.7 m/h as well as OLR of 1.5–2.0 kg COD/(m3·d)

Compress-forward coding with N-PSK modulation for the half-duplex Gaussian relay channel

Systems and methods that implement compress-forward (CF) coding with N-PSK modulation for the relay channel are disclosed, where N is greater than or equal to two. In the CF scheme, Wyner-Ziv coding is applied at the relay to exploit the joint statistics between signals at the relay and the destination. Quantizer design and selection of channel code parameters are discussed. Low-density parity check (LDPC) codes are used for error protection at the source, and nested scalar quantization (NSQ) and irregular repeat accumulate (IRA) codes for Wyner Ziv coding (or more precisely, distributed joint source-channel coding) at the relay. The destination system decodes original message information using (a) a first signal received from the source in a first interval and (b) a second signal that represents a mixture of transmissions from the source and relay in the second interval.U