Science Progress最新文献

To solve the problem of uneven dust cleaning in filter cartridges, a simple and easy-to-install "branch-type" nozzle structure was designed to improve cleaning efficiency. In this study, numerical simulations, range analysis methods, orthogonal experimental design, back-blowing experiments, and powder cleaning experiments were conducted. By choosing the back-blowing uniformity as the evaluation index for cleaning performance, with the flow distribution coefficient A, length of branch pipe B, and outlet diameter of main pipe C as the factors, and ignoring the interaction between factors, an orthogonal experiment was designed to simulate the fluid flow field of nine different nozzle structures installed in the back-blowing model. The results were analyzed using range analysis methods, and the optimal nozzle structure parameter combination was determined to be A = 50%/40%/10%, B = 70 mm, and C = 18 mm. Based on the back-blowing experiment, the accuracy of the simulation results was verified, and the back-blowing uniformity was improved by 50.12%. In the powder cleaning experiment, a new method of measuring the mass of dust shaken off by a single pulse of cleaning to calculate the residual dust on the filter cartridge, rather than removing the filter cartridge and weighing it, was found to reduce experimental errors and make the conclusions more solid and convincing. The results showed that the "branch-type" nozzle increases the cleaning efficiency by 37.6% compared with no nozzle installed, proving that the "branch-type" nozzle can reduce the number of reverse cleaning required and extend the cleaning interval, thus optimizing the cleaning performance of the dust collector.

The article identifies key principles of the important role played by low-carbon generation for ecosystems, which explores studies from perspectives of technology, strategy, and policy. In doing so, it provides a scientific basis for policymakers to formulate efficient and feasible plans to reduce emissions via low-carbon generation to revive ecosystems. Various situations are designed for the development path of low-carbon power generation via adaptive and systematic policies with advanced technologies and appropriate strategies. The article goes on to introduce and discuss a collection of papers that explore the restoration of ecosystem by low-carbon power generation. They discuss how to use technology to optimize low-carbon power generation system, analyze the impact of policies on low-carbon power generation, and explain the mechanism of strategies on low-carbon development of ecosystems.

Objective: Hemodynamic monitoring via right heart catheterization (RHC) is critical for managing acute coronary syndrome (ACS) patients with heart failure or cardiogenic shock. However, the prognostic value of RHC-derived hemodynamic indices in ACS patients with left ventricular systolic dysfunction (LVSD) but without heart failure or shock remains uncertain.

Methods: A retrospective cohort study included 1151 consecutive ACS patients who underwent RHC during hospitalization from 2007 to 2016. After excluding patients with shock, pulmonary edema, and severe valvular disease, 750 ACS patients with LVSD and ejection fraction < 50% were analyzed. Major adverse cardiovascular events (MACEs), including myocardial infarction and all-cause mortality, were followed for five years. Cox regression identified predictors of MACEs, adjusting for comorbidities, treatments, and hemodynamic indices, including pulmonary arterial capacitance (PAC).

Results: After a mean follow-up of 4.0 ± 1.7 years, 113 (15.1%) patients experienced MACEs. Multivariate analysis showed that independent predictors included prior stroke, calcified coronary lesions, and PAC. Patients in the lowest PAC tertile (≤2.89 ml/mmHg) had significantly higher risks of myocardial infarction (adjusted hazard ratio [HR]: 3.74; 95% confidence interval [CI]: 1.55-9.07; p = .003), all-cause mortality (adjusted HR: 2.55; 95% CI: 1.27-5.10; p = .008), and MACEs (adjusted HR: 2.35; 95% CI: 1.25-4.42; p = .008) compared to those in the highest tertile (>4.43 ml/mmHg).

Discussion: The study demonstrated that PAC is a notably strong hemodynamic parameter with independent long-term prognostic value in ACS patients with LVSD, who do not present with shock or heart failure. This is the first study to establish the prognostic significance of hemodynamic indices obtained from RHC in this population, extending the clinical relevance of RHC from high-risk to intermediate-risk ACS populations.

Conclusions: The use of RHC to assess hemodynamic indices, including PAC, during index hospitalization in this population may enhance long-term risk stratification and improve outcome prediction.

Fuzzy graphs (FGs) contain dual-nature characteristics that may be extended to intuitionistic fuzzy graphs. These FGs are better at capturing ambiguity in situations in reality involving decision-making than FGs. In this paper, we address decision-making problems based on intuitionistic fuzzy preference relations (IFPRs) by utilizing Signless Laplacian energy (S_LE), intuitionistic fuzzy weighted averaging (IFWA), and intuitionistic fuzzy weighted averaging geometric (IFWAG). The paper suggests an approach that makes use of intuitionistic fuzzy graphs (IFG) and IFPR to optimize batteries for electric vehicles. Electric vehicles (EVs) performance, range, and efficiency are all dependent on battery technology. Research and technological developments may help remove adoption hurdles and increase public interest in EVs. Producers of batteries and automakers are investing in recycling and cost-cutting measures for manufacture. With the use of carbon nanotube electrodes, battery power may be increased tenfold beyond existing capabilities. In a procedure called group decision-making, experts evaluate and choose the best options based on present standards. This method provides crucial data for well-informed decision-making by capturing ambiguity and uncertainty in real-world decision-making. The strategy improves decision-making and maximizes profits, giving investors a useful foundation for choosing environmentally friendly electric vehicle batteries.

The amphipathic nature of helical proteins is crucial to their binding features across a broad spectrum of physiological examples, including heat-shock proteins and hyaluronic acid (HA) receptor binding. By taking advantage of the amphipathic balance of amino acids and their presentation in helical faces, novel synthetic peptides can be designed to improve biofunctionality. We present a new approach for designing synthetic alpha helical peptides using a multifaceted analysis, which allows for new bioengineering designs of amphipathic alpha helices. Amphipathic helical peptides were presented with distinct hydrophobic and hydrophilic faces; two series of analogs, namely, peptides AX9 and AX7, were designed to contain a hydrophobic and hydrophilic face, respectively. The presence of one series of peptides exhibited a distinct hydrophobic face and the second series exhibited a distinct hydrophilic face, which was corroborated with reversed-phase chromatography (C8). Using a multifaceted approach to analyze the potential faces of an amphipathic helix, we demonstrated that these helices contain seven distinct "side-viewed" helical faces (based on the hydrophobic face of the AXP series of analogs), which provides additional spatial dimensional information beyond the averaging effect of the hydrophobic moment generated from the "top-down" view of a helical wheel. Furthermore, we cross-compared our recently published HA-binding peptide in this manner to demonstrate that the most significant binding was related to (1) balanced amphipathicity and (2) a distribution of the key HA-binding domain B1(X₇)B2 presented spatially. For example, our most effective peptide binder 17x-3 has five of seven faces with B1(X₇)B2 domains, while the positive control mPEP35 has three, which reflects a lower affinity. With such a tool, one is able to map helical peptides on an additional dimension to characterize and redesign fundamental amphipathic properties among other critical characteristics, such as sugar and glycan binding, which is a fundamental characteristic feature of cellular interactions in almost every biological system.

A voltage mode capacitance multiplier for ultra-low frequency physiological signal processing is designed with a circuit model. With the proposed multiplier, a filter can achieve a cutoff frequency of 12 mHz with a 1 pF basic capacitance and a 10 kΩ resistor. The corresponding multiplication factor will be 1.35 × 10⁹. By changing the controlling terminal, the multiplication factor can be widely tuned from 1950 to 1.35 × 10⁹ and the corresponding filter cutoff frequency will be from 12 mHz to 8.15 kHz. According to the circuit model, to further increase the multiplication factor to decrease the chip area, more multiplication stages can be added to the feedback loop.

Among the components of high-tech ships, the structural complexity of the propeller profile requires a high degree of flexibility in the CNC polishing machine. In addressing this requirement, the study formulates the flexible optimization problem pertaining to research on the propeller CNC polishing machine. A comprehensive analysis is undertaken to scrutinize the geometric features of the propeller and the phenomenon of polished contact. The propeller profile-polishing head dynamic contact mechanism is revealed, and the contact force characteristics of propeller polishing are obtained. It is suggested that the propeller configuration-process-polishing machine structure coupling mechanism be explored under the influence of polishing contact force. Subsequently, a dynamic model of the propeller CNC polishing process is formulated. Based on the above model, a simulation of the motion personification and structural flexibility of the propeller CNC polishing machine is proposed to obtain dynamic personification and flexibility rules. Integrating polishing contact force characteristics with dynamic personification and flexibility rules, the dynamic flexible collaborative optimization principle of the propeller CNC polishing machine is revealed. On this basis, multi-objective optimization modeling and solving are carried out, forming a new method for the flexible optimization design of propeller CNC polishing machines.

Objectives: Basilar artery atherosclerotic plaque is the predominant cause of stroke in the posterior circulation. İscheamic stroke caused basilar artery atherosclerosis faces a high risk of recurrence despite optimal medical treatment, which might lie in the less than ideal recognition of underlying stroke mechanism and lack of individualized treatment for strokes of different mechanisms. We aim in this study to investigate the effect on stroke mechanism, stroke recurrence and clinical outcome in stroke patients with basilar artery atherosclerosis.

Methods: In this study, 107 ischaemic stroke patients with atherosclerotic stenosis in the BA who were followed up in Uludag University Faculty of Medicine between 1 January 2019 and 1 January 2022. The study was conducted retrospectively and observationally.

Results: According to the results of our study, the degree of stenosis in atherosclerotic stenosis of the symptomatic basilar artery was found to be an independent risk factor for stroke recurrence. Independent risk factors for unfavourable clinical outcomes in these patients were determined as female gender, stenosis being in the proximal segment, stroke mechanism being from artery to artery embolism, and congestive heart failure.

Conclusion: The most striking result of our study is that clinical outcome was found to be closely related to the female gender, the stroke mechanism being artery-to-artery embolism, and the stenosis is in the proximal segment. If stroke mechanisms were evaluated more clearly, it would likely help provide individualised treatments.

Melatonin, N-acetyl-5-methoxytryptamine, is a neuroendocrine hormone secreted by the pineal gland. This pleiotropic indoleamine possesses amphiphilic properties, allowing it to penetrate most biological barriers and exert its effects at the subcellular level. Importantly, melatonin also plays a crucial role in regulating the body's response to circadian rhythms, adapting to internal and external environmental cues. Melatonin functions as a powerful antioxidant and free radical scavenger, protecting cells from oxidative damage. Its diverse physiological roles include maintaining the functional integrity of endothelial cells, thereby preventing atherosclerosis, a major contributor to cardiovascular disease. Additionally, melatonin exhibits antioxidant and free radical scavenging properties, potentially improving metabolic disorders. These combined effects suggest a unique adjunctive therapeutic potential for melatonin in treating cardiovascular diseases. This review aims to explore the mechanisms by which melatonin interacts with the cardiovascular system and investigates its potential use as an adjunctive therapeutic agent in managing cardiovascular disease.

Objective: This retrospective study aimed to investigate the correlation between neutrophil gelatinase-associated lipocalin (NGAL) levels and the clinical progression and severity of diabetes-related acute kidney injury (AKI). The quantitative determination of NGAL in plasma on the Beckman Coulter AU480 analyzer was measured using the Bioporto NGAL Test^TM, a particle-enhanced turbidimetric immunoassay with hospitalized patients at an East Central Georgia Medical Center.

Methods: The clinical determination of plasma NGAL included a retrospective cohort study where 45 adult patients were selectively recruited. The selective criteria were patients with and without diabetes mellitus (DM) at risk for developing AKI admitted to the Medical Center between January and November 2023. All patients included in the study had pNGAL levels measured upon admission and up to 96 h post-admission. Receiver operating characteristics and likelihood ratio methods were used to determine optimal sensitivity, specificity, and cutoff value of pNGAL in AKI patients associated with and without DM.

Results: The intra-assay and interassay imprecision percent relative standard deviation was between 2.7% and 4.2%. pNGAL levels were higher for patients with AKI compared to non-AKI patients, regardless of DM status. The optimal cutoff value for pNGAL to predict AKI for patients with DM was 293 ng/mL, with a sensitivity of 80% and specificity of 87%. In a multivariate logistic regression model, pNGAL levels at 48 h post-admission were determined to be associated with diabetes-related AKI patients.

Conclusion: Plasma NGAL levels at 48 h are associated with patients with diabetes-related AKI. The specific cutoff values for AKI for early diagnosis and risk stratification and its association with comorbidities must be determined to improve patient outcomes.