Science Progress最新文献

Solar power is one renewable energy source that has great promise. Photovoltaic systems are becoming increasingly popular. Using maximum power point tracker technologies is essential for maximizing the amount of power that can be harvested from a solar system. The variability of the highest power point of a solar system is thought to be caused by the interaction of external elements with the system. In light of the foregoing, the study's overarching goal is to figure out how to use an innovative fuzzy logic controller to track a boost converter-based photovoltaic system's peak power point. We use the fuzzy logic controller to make the system more dynamically sensitive to changes in ambient temperature, quick and moderate variations in irradiance, and other environmental factors. The major objective of this research is to improve the fuzzy logic controller's scaling factors and membership functions. There is a correlation between these features and the controller's accuracy, stability, and speed. For the concept of optimization to be executed well, the cutting-edge metaheuristic method known as Arctic puffin optimization was employed. Arctic Puffin Optimization draws its motivation from nature. Comparisons and analyses with other effective optimization algorithms, such as particle swarm optimization and gray wolf optimizer, have shown that Arctic Puffin Optimization outperforms these other optimization procedures when it comes to fuzzy logic controller tuning. Using the MATLAB/Simulink R2020a environment, we test each method for tracking accuracy, efficiency, response time, transient overshoot, and steady-state ripple. A broad variety of weather conditions was used to conduct the investigation. The Arctic puffin optimization-based fuzzy maximum power point tracker controller's tracking efficacy was consistently over 99.8% in all the conditions investigated, according to the simulation findings.

Objective: The physician order for life-sustaining treatment has been implemented in clinical practice for several years. However, the determination that a patient is in the terminal phase of life, a prerequisite for the withdrawal of life-sustaining treatment, lacks objective criteria. This study aimed to evaluate whether hyperlactatemia could serve as a reliable objective indicator for determining the terminal phase.

Methods: In this retrospective cohort study, we included 73,927 patients admitted to our institution from 2018 to 2023 who had at least one blood lactate measurement. We collected data on the highest blood lactate level measured during hospitalization, mortality, medical department, and intensive care unit (ICU) details. The primary endpoint was 30-day mortality, and we analyzed how well the highest lactate level during hospitalization predicted 30-day mortality across different age groups, medical departments, and ICUs.

Results: Among the patients, 5493 died within 30 days of the maximum lactate measurement. The area under the receiver operating characteristic curve (AUROC) for predicting 30-day mortality based on the maximum lactate level was 0.870 (95% confidence interval [CI] 0.865-0.875) in all patients, indicating high accuracy. Setting the cutoff for the maximum lactate level at 20 mmol/L resulted in a precision of 87% and specificity of 99.8%. Subgroup analyses by age, medical department, and ICU yielded consistent results.

Conclusions: Severe hyperlactatemia during hospitalization showed high precision and specificity for predicting 30-day mortality across various patient groups. These findings suggest that hyperlactatemia could serve as an objective auxiliary indicator for determining the terminal phase, potentially improving consistency in end-of-life decision-making in clinical practice.

Objective: To explore the prevalence and risk factors of carotid artery (CA) stenosis among subclavian steal syndrome (SSS) patients and to record their prognoses.

Methods: This observational study was retrospective. From January 2015 to October 2022, 169 patients were diagnosed with SSS. Among them, 51 combined with CA stenosis have surgical indications for both diseases. In this cohort, 24 were treated for subclavian artery (23 endovascular, 1 open), 12 for CA (6 endovascular, 6 open), and 5 for both (1 endovascular, 1 open, 3 hybrid). The primary end point was mortality, and the secondary end points were vessel re-stenosis and other complications. Patients were followed up through outpatient, online, or telephone.

Results: Compared with simple SSS, patients who suffered from both were older (60.51 ± 9.304 versus 66.69 ± 7.921, P < 0.001) and more males (57.6% versus 86.3%, P < .001). Besides, they presented a higher prevalence of hyperhomocysteinemia (P = .015), diabetes mellitus (P = .036), and CVA/TIA (P = .036). No patient died within 30 days after surgery; four complications occurred (1 stroke, 1 hearing loss, 1 TIA, 1 infection). During a median follow-up of 37.6 months, two patients died without relation to the operation, three appeared in-stent restenosis, and one developed contrast nephropathy.

Discussion: This study observed and analyzed different intervention methods and their prognosis in SSS combined with CA stenosis patients, and due to the limited number of participants, more data support would be needed.

Conclusions: The management of SSS patients combined with CA stenosis is more challenging compared to simple SSS. Our research demonstrated different surgical methods and their prognosis.

Objective: Heavy metal pollution is one of the more recent problems of environmental degradation caused by rapid industrialization and human activity. The objective of this study was to isolate, screen, and characterize heavy metal-resistant bacteria from solid waste disposal sites.

Methods: In this study, a total of 18 soil samples were randomly selected from mechanical sites, metal workshops, and agricultural land that received wastewater irrigation. Isolation and screening of the isolates were based on multiple heavy metal (copper (Cu), chromium (Cr), and lead (Pb)) resistance potential. Morphological, biochemical, and 16S rRNA gene sequencing techniques were used to identify the isolates. The minimum inhibitory concentration (MIC) of the potential isolates was further examined at various concentrations (3, 6, 12, 25, 50, and 100 µg/mL). Each isolate's ability to biodegrade and resist antibiotics was also examined.

Results: About 21 bacterial isolates were obtained. Among these, six potential isolates (Agri10^-2Is2, Agri10^-3Is2, Agri10^-3Is1, AL10^-1Is2, AL10^-3Is1, and GA10^-2Is1) were selected. The isolates displayed varied colony morphologies and biochemical characterization features. Phylogenetic tree results revealed that Agri10^-2Is2, Agri10^-3Is2, Agri10^-3Is1, AL10^-1Is2, AL10^-3Is1, and GA10^-2Is1 were identified as Bacillus subtilis, Bacillus subtilis, Bacillus species, Bacillus tequilensis, Klebiesella species, and Cronobacter sakazakii, respectively. Every isolate gave a different MIC value. The biodegradation capacity of Agri10^-2Is2, Agri10^-3Is2, Agri10^-3Is1, AL10^-1Is2, AL10^-3Is1, and GA10^-2Is1 was 92.2%, 92.57%, 92.37%, 92.66%, 92.85%, and 92.52% against Cu; 95.07%, 94.07%, 93.07%, 93.4%, 91.4%, and 94.4% on Cr; and 95.51%, 94.53%, 95.62%, 96.87%, 94.86%, and 97.09% against Pb, respectively. All isolates were found to be resistant to the tested antibiotics.

Conclusion: This study concludes that the selected bacterial isolates could be potential agents for bioremediation of heavy metal-polluted environments.

Existing studies on the symmetric spherical pendulum are limited to small- and moderate-amplitude vibrations. This study was conducted to obtain accurate solutions for analysis of the large-amplitude vibration of a symmetric magnetic spherical pendulum using the continuous piecewise linearization method (CPLM). The stability conditions and bifurcation of the pendulum were derived based on the critical points, while the CPLM was used to estimate the frequency response and vibration histories to less than 0.1% and 1.0% relative error respectively when compared to numerical solutions. The CPLM was found to be significantly more accurate than the Laplace transform homotopy perturbation method and predicted the large-amplitude bi-stable vibrations accurately. The stability analysis that was conducted enabled the characterization of all bounded symmetric vibrations based on the relationship between the cyclotron frequency and azimuthal velocity, whereas the bifurcation analysis confirmed that the symmetric vibrations can undergo pitchfork bifurcation that results in transition from single-well to double-well (or bi-stable) vibrations and vice versa. Finally, a parametric analysis was conducted to study the effect of the cyclotron frequency and uniform azimuthal velocity on the frequency-amplitude response and vibration histories The parametric analysis showed that the frequency-amplitude response has a strong dependence on the cyclotron frequency and azimuthal velocity for all amplitudes. On the other hand, the oscillation profile only depends on the cyclotron frequency and azimuthal velocity for some amplitudes. The results of this study can be applied in the design of energy harvesters and elliptic tanks for liquid transport.

Objective: Cowpea is an important dry bean in developing countries, and its young leaves and green pods are consumed as fresh vegetables. Consuming green pods provides vitamins, minerals, and functional components for small-scale farmers with limited access to vegetables. However, the accumulation process of functional components in young cowpea pods is unknown. Therefore, we evaluated the concentrations of folic acid, phenolic components, and angiotensin-converting enzyme (ACE) inhibitory activity in green pods throughout maturity to determine the accumulation process of functional components.

Methods: Four cowpea genotypes were selected from a mini-core subset of the world cowpea germplasm collection based on protein content, seed size, and seed coat color. The accumulation process of functional components in young cowpea pods was evaluated by measuring the concentrations of folic acid, phenolic components, and ACE inhibitory activity in green pods throughout pod growth (10 days after flowering (DAF): pod elongated, 15 and 20 DAF: seed growth, and 25 DAF: ready for harvest).

Results: Our results demonstrate that consuming green cowpea pods during the early growth stages (10-15 DAF) can simultaneously provide a high content of dual nutrition, folic acid, and phenolic components. In addition, the pod had high ACE inhibitory activity. Folic acid and phenolic components were highest in the early stages of 10 DAF, whereas ACE inhibitory activity remained constant during 10-25 DAF.

Conclusion: Our findings suggest that including green cowpea pods in diets can boost folic acid and phenolic component intakes without disrupting the ACE inhibitory activity. Furthermore, underutilized genetic resources featuring colored seeds would enhance the nutritional value of cowpeas in breeding programs, thereby increasing the nutritional benefits derived from cowpea consumption.

This case report presents the successful management of a rare and complex open ankle fracture-dislocation known as a 'Logsplitter Injury', resulting from a high-energy traumatic event. The patient, a Chinese male in his early 20 s, sustained a severe left lower limb injury in a traffic accident. Initial clinical assessments revealed significant swelling, pain and an open fracture with extensive soft tissue damage. The patient underwent an emergency surgical intervention, involving meticulous wound debridement, internal fixation and reconstruction of the lower tibiofibular union, was performed. The use of vancomycin-loaded polymethylmethacrylate bone cement and negative pressure wound therapy contributed to the favourable outcome. Post-operative care encompassed comprehensive analgesia and infection prevention measures, resulting in substantial ankle function recovery. Follow-up assessments revealed healed fractures and excellent joint alignment, with the patient attaining an AOFAS score of 85, indicative of good functional recovery. This case underscores the effectiveness of individualised treatment plans and multidisciplinary teamwork in managing such challenging injuries, offering valuable clinical insights and highlighting the potential for successful outcomes with timely and precise surgical interventions.

IntroductionThe aim of this study was to assess the potential role of complete blood count (CBC) inflammatory parameters in the diagnosis and management of missed abortions during early pregnancy through the analysis of their values.MethodsThe case group for our study comprised 500 instances of missed abortions at Fujian Provincial Maternal and Child Health Hospital from May 2023 to May 2024, whereas the control group consisted of 500 healthy women who did not experience delivery-related complications during this timeframe. We utilized SPSS version 25 software to conduct a retrospective analysis of factors, including age, BMI, gravidity, parity, neutrophil count, lymphocyte count, platelet count, mean platelet volume, platelet distribution width, and prothrombin time.ResultsThe age and gravidity of patients in the missed abortion group were higher than those in the normal pregnancy group, with a statistically significant difference. There were no significant differences in the platelet count, mean platelet volume, platelet distribution width, neutrophil count, or prothrombin time between the two groups. But the lymphocyte count was significantly lower in the missed abortion pregnancies. The area under the ROC curve for the lymphocyte count was 0.654, indicating its diagnostic value.ConclusionAlthough the lymphocyte count can offer some predictive value in detecting missed abortion, its diagnostic accuracy is limited. Other inflammatory parameters don't yield any predictive information regarding miscarriage retention.

Objective: This study investigated the fungal contamination profile of cocoa beans from cocoa-growing regions in Ghana, with particular emphasis on the potential impact of ochratoxigenic Aspergillus species.

Methods: A total of 104 fermented and dried cocoa beans were randomly collected from farmers for analysis. Fungal isolation was conducted using potato dextrose agar and malt extract agar media. Species-level identification was performed through macroscopic and microscopic techniques. Ochratoxin A (OTA) quantification and confirmation were carried out using high-performance liquid chromatography with fluorescence detection and liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results: The investigation revealed 163 fungal isolates representing 14 distinct species across 10 genera. Aspergillus species, including Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, and Aspergillus fumigatus, were predominant. No statistically significant differences in fungal species occurrence were observed among the different cocoa-growing regions. However, certain species exhibited preferential growth on specific media, emphasizing the importance of medium selection in mycological studies. Of the 14 fungal species tested, only Aspergillus niger demonstrated the ability to produce OTA in vitro, as confirmed by LC-MS/MS analysis.

Conclusion: This discovery holds substantial implications for both the cocoa industry and public health, considering that OTA is a potent mycotoxin subject to strict regulatory limits in food commodities. It is crucial to implement enhanced monitoring and control measures to mitigate fungal contamination in cocoa beans, particularly targeting OTA-producing species. The study also highlights the need for improved post-harvest handling practices, optimized storage conditions, and potential biocontrol approaches.

Objective: This study aims to analyze anatomical parameters of the transmission route of sigmoid sinus tinnitus (SST) to explore its mechanism and speculate on possible responsible anatomical abnormalities.

Methods: Clinical data were retrospectively collected from SST and sigmoid sinus wall dehiscence (SSWD) patients suggested by temporal bone high resolution computed tomography (HRCT), with and without tinnitus, at the First Affiliated Hospital of Chongqing Medical University from January 2015 to August 2022. Patients were divided into SSWD tinnitus (n = 61), and non-tinnitus (n = 60) groups based on HRCT features. Mimics Medical 22.0 and 3-matic Medical 13.0 software measured curvature of the sigmoid sinus bone wall, defect distribution, related parameters, distance to the tympanic sinus and cochlear window, degree of mastoid pneumatization, temporal bone air chamber surface area, volume, and S/V value. Mechanisms were analyzed by comparing clinical data and imaging anatomical parameters between groups.

Results: The tinnitus group was significantly younger and had more severe low-frequency hearing loss (P = 0.002). The degree of mastoid pneumatization was significantly lower in the tinnitus group (P = 0.032). The volume of the temporal bone air chamber was smaller (P = 0.020), and the S/V value was higher in the tinnitus group (P = 0.001). Bone wall defects in the lower curvature were protective against tinnitus (P = 0.007, OR = 0.071). Larger maximum transverse diameter of the defect increased tinnitus risk (P = 0.030, OR = 1.875). Higher S/V value was also a significant risk factor (P = 0.009, OR = 24.210).

Conclusions: SST patients exhibit significant female and right-sided predominance, with low-frequency hearing loss. Defects in the superior curvature and descending part of the sigmoid groove are more likely to cause tinnitus. Larger transverse diameters and higher S/V values are independent risk factors for tinnitus. Over-pneumatized temporal bones do not facilitate transmission of sigmoid sinus blood flow murmur, highlighting the importance of specific anatomical features in SST development.