This study is devoted to free vibration analysis of cracked temperature-dependent functionally graded beams under nonlinear temperature rise. First, governing equations for vibration of temperature-dependent beam structures are established using the power law of material gradation, the double spring model of open transverse crack and Timoshenko beam theory. The constructed analytical model of the beams allows thoroughly investigating the crack compliance (local flexibility) in dependence upon material gradation index, crack depth and temperature. Second, using exact analytical method, general solution for free vibration of the beams with single crack is conducted and used for examining variation of the beam’s natural frequencies along crack position and depth, material gradient index and temperature rise of different distributions. Numerical results demonstrate that crack compliance increases with crack depth and decreases for growing material gradient index and temperature rise. Moreover, it is revealed also that temperature rise has a significant effect on either natural frequencies or their sensitivity to the crack. The theoretical development has been validated by comparison of the numerical results computed hereby with those published earlier in the literature.
Professionalism constitutes a core requirement for civil servants in the public service, particularly in the context of Vietnam's deepening international integration. This study aims to clarify the essential qualities, capacities and professional reputation that Vietnamese civil servants must possess to meet contemporary governance demands. To accomplish this, the research examines current legal documents governing civil servant standards and surveys 175 respondents to assess the current status and solution requirements for enhancing professionalism. Findings indicate that reforms in public administration and the pressures of international integration have contributed to improving the qualities, capacities and professional standing of civil servants. Nevertheless, persistent limitations remain, especially regarding foreign language proficiency, technological competence and the uneven ability to adapt to global administrative practices. These shortcomings highlight the need for continued efforts to strengthen professional standards. Drawing on survey data, legal analysis and empirical assessment, the study proposes targeted solutions aimed at promoting a more capable, adaptive and internationally aligned civil service capable of meeting present and future challenges.
Soil microbiomes are critical for ecosystem functioning, yet the global influences of climate and agricultural practices on their diversity and structure remain incompletely characterized. Here we analyzed 1921 soil samples from 33 countries worldwide across diverse biomes to assess how climate gradients and agricultural inputs, including pesticides and fertilizers, shape prokaryotic and fungal communities. We found that microbial diversity peaks at intermediate temperatures and differs markedly between natural and agricultural soils, with agriculture increasing microbial diversity while altering community composition and ecological guilds. Pesticide use selectively reduced bacterial diversity and shifted fungal guilds, decreasing ectomycorrhizal fungi while increasing saprotrophs, whereas fertilization reduced microbial network cohesion, with organic and inorganic fertilizers eliciting distinct community responses. These findings reveal that climatic factors and agricultural management jointly influence soil microbial diversity, community structure, and network connectivity, with implications for soil health and ecosystem resilience in managed landscapes. Overall, our results demonstrate that agricultural practices, including the use of pesticides and both organic and inorganic fertilizers, act as strong ecological filters that reshape soil microbiomes worldwide-enhancing apparent diversity but driving a functional shift toward less mutualistic, more fragmented, and potentially less resilient communities.
OBJECTIVE:Antimicrobial resistance (AMR) is a major challenge in complicated urinary tract infections (cUTIs), particularly among high-risk patients in resource-limited settings. METHODS:This retrospective study (January 2019-December 2023) analyses 622 urine culture-positive samples from cUTI patients at a rehabilitation centre to investigate pathogen distribution, AMR patterns, and associations with clinical outcomes using descriptive statistics and regression models. RESULTS:Escherichia coli (46%) was the predominant isolate, followed by Klebsiella pneumoniae (16%). Although Enterococcus faecalis and Pseudomonas aeruginosa were less common, their prevalence increased over time. High resistance rates to ciprofloxacin and ceftriaxone were observed in E. coli (69.5%, 74.7%) and K. pneumoniae (60.2%, 58.1%). Carbapenem resistance emerged in P. aeruginosa (51.4%) and K. pneumoniae (37.5%), with prior antibiotic exposure identified as a significant predictor (OR: 2.15; 95% CI:1.33-3.47; P = 0.002). In contrast, E. coli and E. faecalis retained high susceptibility to nitrofurantoin and fosfomycin. Multidrug-resistant (MDR) infections were independently associated with prolonged hospital stay (β = 1.889; P = 0.045). CONCLUSIONS:The high prevalence of resistance to first-line agents and emergence of carbapenem resistance underscore the urgent need for antimicrobial stewardship (AMS) interventions. The study suggests specific hospital-setting AMS should be prioritized the judicious use of agents such as nitrofurantoin and fosfomycin, which retain clinical effectiveness. Addressing MDR is crucial as it represents a key modifiable determinant of length of hospital stay in patients with cUTI.
This study focuses on developing novel materials based on lysozyme, a protein derived from egg white, modified with aluminum hydroxide nanoparticles (γ-Al(OH)3 and α-Al(OH)3) via an adsorption technique to enhance oxytetracycline antibiotic (OTC) removal from water systems. The optimal parameters for lysozyme adsorption on both phases of Al(OH)3 were determined to be a pH of 10, a contact time of 120 min, an Al(OH)3 dosage of 10 mg/mL, and an ionic strength of 1 mM KCl. For OTC removal using lysozyme-modified γ-Al(OH)3 (LGH) and α-Al(OH)3 (LAH), the optimum conditions were identified as a pH of 6, an adsorbent dosage of 10 mg/mL, and a contact time of 90 min. The adsorption kinetics of OTC on both materials adhered to the pseudo-second-order model, while the Freundlich model provided the best fit for the adsorption isotherms. The LGH demonstrated a higher OTC adsorption capacity of 62.9 mg/g compared to LAH with 45.7 mg/g. The adsorption mechanism for OTC on LGH was primarily driven by nonelectrostatic interactions, whereas electrostatic forces predominantly governed OTC adsorption on LAH. Even after four regeneration cycles, the OTC removal efficiencies remained above 70.5% for LGH and 87.9% for LAH. These findings highlight that both lysozyme-modified aluminum hydroxides are environmentally friendly and highly effective materials for removing OTC from aquatic environments.
