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1.
Heliyon ; 10(10): e30528, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38765046

RESUMEN

Diagnosing liver disease presents a significant medical challenge in impoverished countries, with over 30 billion individuals succumbing to it each year. Existing models for detecting liver abnormalities suffer from lower accuracy and higher constraint metrics. As a result, there is a pressing need for improved, efficient, and effective liver disease detection methods. To address the limitations of current models, this method introduces a deep liver segmentation and classification system based on a Customized Mask-Region Convolutional Neural Network (cm-RCNN). The process begins with preprocessing the input liver image, which includes Adaptive Histogram Equalization (AHE). AHE helps dehaze the input image, remove color distortion, and apply linear transformations to obtain the preprocessed image. Next, a precise region of interest is segmented from the preprocessed image using a novel deep strategy called cm-RCNN. To enhance segmentation accuracy, the architecture incorporates the ReLU activation function and the modified sigmoid activation function. Subsequently, a variety of features are extracted from the segmented image, including ResNet features, shape features (area, perimeter, approximation, and convex hull), and enhanced median binary pattern. These extracted features are then used to train a hybrid classification model, which incorporates classifiers like SqueezeNet and DeepMaxout models. The final classification outcome is determined by averaging the scores obtained from both classifiers.

2.
Materials (Basel) ; 17(9)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38730768

RESUMEN

A promising method for additive manufacturing that makes it possible to produce intricate and personalized parts is selective laser melting (SLM). However, the mechanical properties of as-corroded SLM parts are still areas of concern. This research investigates the mechanical behavior of SLM parts that are exposed to a saline environment containing a 3.5% NaCl solution for varying lengths of time. The exposure times chosen for this study were 10 days, 20 days, and 30 days. The results reveal that the tensile strength of the parts is significantly affected by the duration of exposure. Additionally, the study also examined the influence of porosity on the corrosion behavior of the parts. The analysis included studying the mass loss of the parts over time, and a regression analysis was conducted to analyze the relationship between exposure time and mass loss. In addition, the utilization of scanning electron microscopy (SEM) and X-ray photo spectroscopy (XPS) techniques yielded valuable insights into the fundamental mechanisms accountable for the observed corrosion and mechanical behavior. It was found that the presence of corrosion products (i.e., oxide layer) and pitting contributed to the degradation of the SLM parts in the saline environment. This research emphasizes the importance of considering part thickness in the design of SLM components for corrosive environments and provides insights for enhancing their performance and durability.

3.
Front Neurosci ; 18: 1363930, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38680446

RESUMEN

Introduction: In neurological diagnostics, accurate detection and segmentation of brain lesions is crucial. Identifying these lesions is challenging due to its complex morphology, especially when using traditional methods. Conventional methods are either computationally demanding with a marginal impact/enhancement or sacrifice fine details for computational efficiency. Therefore, balancing performance and precision in compute-intensive medical imaging remains a hot research topic. Methods: We introduce a novel encoder-decoder network architecture named the Adaptive Feature Medical Segmentation Network (AFMS-Net) with two encoder variants: the Single Adaptive Encoder Block (SAEB) and the Dual Adaptive Encoder Block (DAEB). A squeeze-and-excite mechanism is employed in SAEB to identify significant data while disregarding peripheral details. This approach is best suited for scenarios requiring quick and efficient segmentation, with an emphasis on identifying key lesion areas. In contrast, the DAEB utilizes an advanced channel spatial attention strategy for fine-grained delineation and multiple-class classifications. Additionally, both architectures incorporate a Segmentation Path (SegPath) module between the encoder and decoder, refining segmentation, enhancing feature extraction, and improving model performance and stability. Results: AFMS-Net demonstrates exceptional performance across several notable datasets, including BRATs 2021, ATLAS 2021, and ISLES 2022. Its design aims to construct a lightweight architecture capable of handling complex segmentation challenges with high precision. Discussion: The proposed AFMS-Net addresses the critical balance issue between performance and computational efficiency in the segmentation of brain lesions. By introducing two tailored encoder variants, the network adapts to varying requirements of speed and feature. This approach not only advances the state-of-the-art in lesion segmentation but also provides a scalable framework for future research in medical image processing.

4.
Heliyon ; 10(2): e24267, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38304837

RESUMEN

In the current studies two naproxen derivatives (NPD) were evaluated for analgesic and anti-inflammatory properties. The acetic acid and hot plate animal models were used to screen the compounds for analgesic potential. While the anti-inflammatory potential was evaluated through animal paw edema, induced by several inflammatory mediators (carrageenan, bradykinin, and prostaglandin E2), the xylene-induced ear edema was also used as an inflammatory model. Both NPDs showed significant (p < 0.001) antinociceptive effects in the acetic acid-induced writhing paradigm. In the case of the hot plate, the NPD 1 at the tested dose of 5 mg/kg enhanced the latency time after 60 min of injection, which remained significant (p < 0.001) up to the end of the experiment duration. The maximum percent inhibition of NPD 1 was 87.53. The naloxone injection significantly lowered the latency time of NPD 1 as compared to NPD 2. Regarding the anti-inflammatory effect, both of the tested NPDs demonstrated a significant reduction in paw edema against various inflammatory mediators, as mentioned above; however, the anti-inflammatory effect of NPD 1 was better. The maximal percent inhibition by NPD 1 and 2 was 43.24 (after 60 min) and 45.93 (after 90 min). A considerable effect also resulted from xylene-induced ere edema. Further, a molecular docking study was carried out to investigate the binding modes of the NPD. The docking analysis revealed that the NPD significantly interacted with the COX2 enzyme. Furthermore, molecular dynamics simulation was carried out for the docked complexes. The MD simulation analysis revealed the high stability of the two naproxen derivatives.

5.
Small Methods ; : e2301667, 2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38403871

RESUMEN

Ultrahigh-capacity silicon (Si) anodes are essential for the escalating energy demands driven by the booming e-transportation and energy storage field. However, their practical applications are strictly hampered by their intrinsically low electroconductivity, sluggish Li-ion diffusion, and undesirably large volume change. Herein, a high-performance Si anode, comprised of a modulated soft/hard coating of polyethylene glycol (PEG) (as Li-ion conductor) and polyaniline (PANI) (as electron conductor) on the surface of Si nanoparticles (NPs) through H-bonding network, is introduced. In this design, the abundant ─OH groups of soft PEG allow it to uniformly cover Si NPs while the hard PANI binds to PEG through its ─N─H group, thus constructing a tight connectin between Si and PEG-PANI (PP). Consequently, the elastic PP allows Si@PP to accommodate the huge volume expansion while possessing fine electronic/ionic conductivity. Therefore, the Si@PP anode exhibits a high initial Coulombic efficiency of 90.5% and a stable capacity of 1871 mAh g-1 after 100 cycles at 1 A g-1 with a retention of 85.7%. Additionally, the Si@PP anode also demonstrates a high areal capacity of 3.01 mAh cm-2 after 100 cycles at 0.5 A g-1 . This work reveals a scalable interface design of multi-layer multifunctional coatings for high-performance electrode materials in next-generation Li-ion batteries.

6.
Interdiscip Sci ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38413547

RESUMEN

Kidney ultrasound (US) images are primarily employed for diagnosing different renal diseases. Among them, one is renal localization and detection, which can be carried out by segmenting the kidney US images. However, kidney segmentation from US images is challenging due to low contrast, speckle noise, fluid, variations in kidney shape, and modality artifacts. Moreover, well-annotated US datasets for renal segmentation and detection are scarce. This study aims to build a novel, well-annotated dataset containing 44,880 US images. In addition, we propose a novel training scheme that utilizes the encoder and decoder parts of a state-of-the-art segmentation algorithm. In the pre-processing step, pixel intensity normalization improves contrast and facilitates model convergence. The modified encoder-decoder architecture improves pyramid-shaped hole pooling, cascaded multiple-hole convolutions, and batch normalization. The pre-processing step gradually reconstructs spatial information, including the capture of complete object boundaries, and the post-processing module with a concave curvature reduces the false positive rate of the results. We present benchmark findings to validate the quality of the proposed training scheme and dataset. We applied six evaluation metrics and several baseline segmentation approaches to our novel kidney US dataset. Among the evaluated models, DeepLabv3+ performed well and achieved the highest dice, Hausdorff distance 95, accuracy, specificity, average symmetric surface distance, and recall scores of 89.76%, 9.91, 98.14%, 98.83%, 3.03, and 90.68%, respectively. The proposed training strategy aids state-of-the-art segmentation models, resulting in better-segmented predictions. Furthermore, the large, well-annotated kidney US public dataset will serve as a valuable baseline source for future medical image analysis research.

7.
Adv Mater ; 36(8): e2309921, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38016083

RESUMEN

Metal halide perovskite light-emitting diodes (PeLEDs) are attracting increasing attention due to their potential applications in flat panel lighting and displays. The solution process, large-area fabrication, and flexibility are attractive properties of PeLEDs over traditional inorganic LEDs. However, it is still very challenging to deposit uniform perovskite films on flexible substrates using a blade or slot-die coating, as the flexible substrate is not perfectly flat. Here, the inkjet printing technique is adopted, and the key challenges are overcome step-by-step in preparing large-area films on flexible substrates. Double-hole transporting layers are first used and a wetting interfacial layer to improve the surface wettability so that the printed perovskite droplets can form a continuous wet film. The fluidic and evaporation dynamics of the perovskite wet layer is manipulated to suppress the coffee ring effect by solvent engineering. Uniform perovskite films are obtained finally on flexible substrates with different perovskite compositions. The peak external quantum efficiency of the inkjet-printed PeLEDs reaches 14.3%. Large-area flexible PeLEDs (4 × 7 cm2 ) also show very uniform emission. This work represents a significant step toward real applications of large-area PeLEDs in flexible flat-panel lighting.

8.
ACS Appl Mater Interfaces ; 15(50): 58429-58436, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38079626

RESUMEN

The construction of an artificial protective layer is an effective method to solve the issues, such as uncontrolled dendrite growth and an unstable solid electrolyte interphase, at the K metal anode. This study proposes a new dynamic evolution strategy that integrates the advantages of previous in situ and ex situ fabrication processes. A multifunctional protective layer enriched with K-Ge alloy is prepared on the K metal electrode by simple surface modification and in situ reduction via an electrochemical process. The protective layer has good potassiophilicity, mechanical flexibility, and high ionic conductivity, which can inhibit dendrite growth and reduce side reactions. The protected K electrode with a protective layer exhibits dendrite-free K plating/striping behavior, and the symmetric cell can run stably for over 1000 h at 1 mA cm-2 and 1 mAh cm-2. Notably, full cells based on this electrode also present excellent rate and cycling performance compared to those of the bare K electrode. This peculiar strategy will open a new avenue for metal anode protection and can be extended to other high-energy battery systems.

9.
Cureus ; 15(10): e47342, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38022127

RESUMEN

Background Intensive care units frequently contend with infections caused by highly drug-resistant organisms, particularly Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE), which often lead to high mortality rates. Colistin (colomycin) is employed to treat infections, notably extremely drug-resistant (XDR) bacteria. Antibiotic combination treatment is a frequently used tactic in this endeavour. However, the widespread use of antibiotics in synergy could result in the emergence of resistance and a rise in side effects, such as those linked to Clostridium difficile infection. The aim of the study was to assess and contrast the clinical results of intravenous colistin monotherapy with the combination of colistin and meropenem in patients experiencing MDR bacteremia resulting from Acinetobacter Baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE). Methods In this retrospective observational study, an analysis spanning two years, from June 2021 to June 2023, was conducted at a teaching hospital located in Karachi, Pakistan. The research involved the retrospective examination of medical records from 132 patients who had been diagnosed with MDR bacteremia. Patients were divided into two categories based on their treatment regimen, either intravenous colistin monotherapy or intravenous colistin combined with meropenem. Among the 132 patients included in the analysis, 66 underwent colistin monotherapy, while the other 66 received a combination of colistin and meropenem. The primary focus of evaluation in this study centered on the 14-day all-cause mortality, while secondary outcomes encompassed clinical success and microbiologic cure. Results The mean age of patients in both groups was comparable, and there were no noteworthy gender differences. Additionally, the distribution of infection types and the isolated pathogens showed no substantial distinctions between the two groups. The study revealed no statistically significant disparities in 14-day mortality, improvement in Sequential Organ Failure Assessment (SOFA) score, or the proportion of patients who were cured and survived between the two treatment groups. Conclusion The findings from this study lead to the conclusion that there exists no significant disparity in the efficacy of colistin monotherapy compared to the combination of colistin with meropenem in the treatment of MDR bacteremia stemming from Acinetobacter Baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE). The results provide a basis for future research and underscore the significance of ongoing endeavors to refine antibiotic treatment strategies in response to the worldwide issue of antibiotic resistance.

10.
Qatar Med J ; 2023(4): 27, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37936885

RESUMEN

INTRODUCTION: Pets and exotic animals are increasingly popular all over the world. Some of these animals may cause injuries to their owners or other people during interactions. Both injuries and systemic infections always present diagnosis and treatment challenges. Emergency physicians´ clinical experience in managing patients with injuries caused by pets and exotic animals, in particular, is limited; hence, we believe that it is a domain to explore in a Middle Eastern country to help raise awareness and provide reminders as to the best evidence-based medical practice. METHODS: Hamad Medical Corporation's hospital records of patients treated between 2015 and 2022 were analyzed retrospectively. Cases whose diagnosis was recorded as injuries caused by animals kept as pets were included in the study. Patients were evaluated in terms of demographic characteristics, type of injury, injury locations, injury severity, treatments applied, and complications. Descriptive statistics were carried out, and findings were expressed as percentages in a frequency table. RESULTS: Following a search of the electronic patient records during the period of interest, 43 patients were found to have sought treatment following an injury caused by a pet or domestic exotic animal. The mean age of the patients was 23.5 years; about three-quarters were male, and approximately half were children. All injuries were minor, and 74.4% were skin abrasions. The most commonly injured body parts were the hand, the leg, and facial injuries. It was observed that cats caused 53.5% of the injuries, whereas falcons were involved in 11.6% of the cases. All patients were prescribed prophylactic antibiotics, and 60.5% were administered a tetanus injection. CONCLUSION: Despite our study spanning over seven years, a relatively low number of patients reported to the government hospitals´ emergency departments. The injuries are most commonly caused by cats and often involve children and animal bites to hands. The key recommendations are for parents or childminders to always supervise children when interacting with animals, be particularly cautious, and wear some form of protection when handling pets and domestic, exotic animals. Whether it is a bite or a scratch, healthcare professionals should always anticipate the potential risk of infection, treat the patient accordingly, and prescribe prophylactic antibiotics.

11.
Pak J Pharm Sci ; 36(2): 373-378, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37530143

RESUMEN

Hyperglycemia is a long-lasting syndrome that occurs either when the pancreas cannot produce enough insulin, or the body cannot effectively utilize that insulin to regulate blood sugar levels. Non-insulin-dependent hyperglycemia, also known as type II diabetes, causes a common consequence of severe damage to many of the body's organs mainly the blood vessels and nerves. The majority of people around the world are suffering from non-insulin-dependent diabetes. The present work showed a great effort to investigate any possible interaction between antacids and sitagliptin (anti-diabetic drug) in the treatment of type II diabetes with gastrointestinal tract problems. The in vitro studies were carried out in simulated gastric juice pH 2.0 and intestinal pH 7.4 at 37oC. MgCO3, NaHCO3, Mg(OH)2, Al(OH)3 and CaCO3 were used as antacids in these studies. It has been observed that % release of sitagliptin was significantly enhanced in the presence of calcium carbonate and magnesium carbonates.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperglucemia , Humanos , Antiácidos/uso terapéutico , Fosfato de Sitagliptina/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Carbonato de Calcio/uso terapéutico , Hiperglucemia/tratamiento farmacológico
12.
Asian Pac J Cancer Prev ; 24(7): 2427-2430, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37505776

RESUMEN

OBJECTIVES: With the objective of establishing a simple, cost-effective, and effective screening tool for the screening of Human Papilloma Virus infection, the study was undertaken. MATERIAL METHODS: This pilot study was conducted on 20 urine samples of women whose cervical swabs were tested positive while screening for Human papilloma virus in asymptomatic women. RESULTS: HPV genotypes were detected in 94% (16/17) patients in urine samples by real-time PCR while a 100% detection rate (15/15) was observed in the cervical swab samples. The results of the urine and cervical swab samples, tested by the TRUPCR ®HPV high-risk genotyping kit, are shown in Table 2. HPV genotype 68 was found in 82.3% urinary samples and 100% of self-collected vaginal swab samples. Out of 16 positive urine samples, 2 were positive for HPV genotype 16 and 5 were positive for HPV genotype 18, and in cervical swab testing out of 15 positive samples, 3 were positive for HPV genotype 16, and 5 were positive for HPV genotype 18. Diagnostic accuracy of urine was found to be 98.8% (95% CI 79.43% - 100.00%). CONCLUSION: This pilot study aims to assess the accuracy of urine samples in the screening of HPV infection among asymptomatic women and establish the distribution of prevalent HPV genotypes. This may further contribute to standardizing the urine and cervical swab testing methods for cervical cancer screening strategies.


Asunto(s)
Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Humanos , Femenino , Virus del Papiloma Humano , Infecciones por Papillomavirus/diagnóstico , Proyectos Piloto , Detección Precoz del Cáncer/métodos , Genotipo , Papillomaviridae/genética , ADN Viral/análisis , Frotis Vaginal/métodos
13.
ACS Appl Mater Interfaces ; 15(31): 37486-37496, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37492883

RESUMEN

Developing sodium-ion batteries (SIBs) with high initial coulombic efficiency (ICE) and long-term cycling stability is crucial to meet energy storage device requirements. Designing anode materials that could exhibit high ICE is a promising strategy to realize enhanced energy density in SIBs. A trifunctional network binder substantially improves the electrochemical performance and ICE, providing excellent mechanical properties and strong adhesion strength. A rationally designed electrode material and binder can achieve high ICE, long cycling performance, and excellent specific capacity. Here, a NiS/NiS2 heterostructure as an anode material and a trifunctional network binder (SA-g-PAM) are designed for SIBs. Unprecedently, the anode comprising of an SA-g-PAM binder achieved the highest ICE of 90.7% and remarkable cycling stability for 19000 cycles at a current density of 10 A g-1 and maintained the specific capacity of 482.3 mAh g-1 even after 19000 cycles. This exciting work provides an alternate direction to the battery industry for developing high-performance electrode materials and binders with high ICE and excellent cycling stability for energy storage devices.

14.
Front Chem ; 11: 1197665, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37441272

RESUMEN

Breast cancer covers a large area of research because of its prevalence and high frequency all over the world. This study is based on drug discovery against breast cancer from a series of imidazole derivatives. A 3D-QSAR and activity atlas model was developed by exploring the dataset computationally, using the machine learning process of Flare. The dataset of compounds was divided into active and inactive compounds according to their biological and structural similarity with the reference drug. The obtained PLS regression model provided an acceptable r 2 = 0.81 and q2 = 0.51. Protein-ligand interactions of active molecules were shown by molecular docking against six potential targets, namely, TTK, HER2, GR, NUDT5, MTHFS, and NQO2. Then, toxicity risk parameters were evaluated for hit compounds. Finally, after all these screening processes, compound C10 was recognized as the best-hit compound. This study identified a new inhibitor C10 against cancer and provided evidence-based knowledge to discover more analogs.

15.
Nat Prod Res ; : 1-7, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37458205

RESUMEN

The work is aimed to evaluate the blood pressure reducing effect of constituents from methanol extract and associated constituents of Tagetes patula flowers in normotensive and L-NAME induced hypertensive rats. The HPLC analysis of methanol extract of Tagetes patula flowers (JFM) resulted in the quantitative identification and percent comparison of four phenolic constituents, protocatechuic acid (PA), methyl protocatechuate (MPA), patulitrin (TRIN) and patuletin (PAT). All the extracts, fractions and compounds examined showed significant blood pressure lowering activity. Patulitrin (TRIN) which has emerged as the major constituent (15.33%) of T. patula flowers showed significant 30% and 68% fall in blood pressure in normotensive and L-NAME induced hypertensive rats respectively. The patuletin (PAT), which is an aglycone of TRIN displayed high percentage (84%) of antihypertensive activity. Further, comprehensive and advanced studies on these constituents may result in preparation of an effective blood pressure lowering medicine with active precious rare flavonoids, patuletin and patulitrin.

16.
BMC Res Notes ; 16(1): 89, 2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37231420

RESUMEN

OBJECTIVE: Despite quality of life (QoL) being recognized as an important outcome in neuro-oncology, there is a lack of research from Pakistan where sociocultural differences may influence QoL. This study aimed to measure the QoL in patients with primary brain tumors (PBTs) and assess its association with mental health outcomes and social support. RESULTS: Our study included a total of 250 patients, with a median age of 42 years (range 33-54 years). The commonest brain tumors were glioma (46.8%) and meningioma (21.2). The mean global QoL of the sample was 75.73 ± 14.9. The majority of patients had high social support (97.6%) and were not depressed (90%) or anxious (91.6%). On multivariable linear regression, global QoL was inversely associated with no or low income (beta coefficients: -8.75 to -11.84), having hypertension (-5.53), currently using a urine catheter (-13.55), having low social support (-28.16) suffering from mild (-15.31) or symptomatic (-23.84) depression, or mild anxiety (-13.22).


Asunto(s)
Neoplasias Encefálicas , Calidad de Vida , Humanos , Adulto , Persona de Mediana Edad , Calidad de Vida/psicología , Estudios Transversales , Pakistán , Depresión/psicología , Ansiedad
17.
Front Psychol ; 14: 1117967, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37063536

RESUMEN

Introduction: Brain tumor is a devastating and often fatal diagnosis; quality of life and patient well-being are important goals of treatment. This study addresses the gap in culture-specific literature exploring the needs and coping strategies of brain tumor patients within an LMIC setting. Methodology: A qualitative approach was undertaken using an exploratory descriptive study design. In-depth interviews were conducted to capture the perspective of 250 brain tumor patients at a private tertiary center followed by extensive content analysis to identify major themes and sub-themes across responses. Results: The analysis identified three major themes: (i) Factors affecting the lives of brain tumor survivors (BTSs) and their impact (ii) What works to improve QoL according to the survivors' perspectives, and (iii) Coping tactics & fostering healthy relationships. The need for financial navigation strategies improved patient-physician relationships, and reinforcing positive coping strategies were emphasized. Conclusion: In our population, family support and spiritual connection played an important role in helping patients mitigate the psychosocial burden of illness. However, financial concerns were pervasive and need to be addressed for better overall well-being.

18.
Small Methods ; 7(7): e2201247, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37086116

RESUMEN

Realizing efficacious π-donation from the O 2p orbital to electron-deficient metal (t2g ) d-orbitals along with separately tuned adsorption of *O and *OOH, is an imperious pre-requisite for an electrocatalyst design to demonstrate boosted oxygen evolution reaction (OER) performance. To regulate the π-donation and the adsorption ability for *O and *OOH, herein, a facile strategy to modulate the electron transfer from electron-rich t2g -orbitals to electron-deficient t2g -orbitals, via strong π-donation from the π-symmetry lone pairs of the bridging O2- , and the d-band center of a biomimetic honeycomb (BHC)-like nanoarchitecture (Ir1- x (Ir0.8 V0.2 O2 )x -BHC) is introduced. The suitable integration of V heteroatoms in the single crystal system of IrO2 decreases the electron density on the neighboring Ir sites, and causes an upshift in the d-band center of Ir1- x (Ir0.8 V0.2 O2 )x -BHC, weakening the adsorption of *O while strengthening that of *OOH, lowers the energy barrier for OER. Therefore, BHC design demonstrates excellent OER performance (shows a small overpotential of 238 mV at 10 mA cm-2 and a Tafel slope of 39.87 mV dec-1 ) with remarkable stability (130 h) in corrosive acidic electrolyte. This work opens a new corridor to design robust biomimetic nanoarchitectures of modulated π-symmetry (t2g ) d-orbitals and the band structure, to achieve excellent activity and durability in acidic environment.

19.
Materials (Basel) ; 16(5)2023 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-36903217

RESUMEN

The rolling process of rebar steel production is one of the well established manufacturing processes; however, it should be subjected to revision and redesign for productivity enhancement and power reduction throughout the slit rolling process. In this work, slitting passes are extensively reviewed and modified for the attainment of better rolling stability and reduction in power consumption. The study has been applied for grade B400B-R Egyptian rebar steel, which is equivalent to steel grade ASTM A615M, Grade 40. Traditionally, the rolled strip in the rolling pass is edged before implementing a slitting pass using grooved rolls; this produces a single barreled strip. This single barrel form causes instability in the next slitting stand on the pressing by the slitting roll knife. Multiple industrial trials are attempted to achieve the deformation of the edging stand using a grooveless roll. As a result, a double barreled slab is produced. In parallel, finite element simulations of the edging pass are performed using grooved and grooveless rolls, and similar slab geometry with single and double barreled form are produced. In addition, further finite element simulations of the slitting stand are execute using idealized single barreled strips. The power calculated by the FE simulations of the single barreled strip is (245 kW), which is in acceptable agreement with the experimental observations in the industrial process (216 kW). This result validates the FE modeling parameters such as material model and boundary conditions. The FE modeling is extended to the slit rolling stand of a double barreled strip, which was previously produced by the grooveless edging rolls. It is found that the power consumption is (165 kW) 12% lower than the power consumed (185 kW) for slitting the single barreled strip.

20.
Entropy (Basel) ; 25(3)2023 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-36981340

RESUMEN

We present an analysis of the pseudorapidity η and transverse momentum pT distributions of charged hadrons in pp collisions for the kinematic range of 01 GeV/c at 0.9 and 2.36 TeV within the experimental errors, while Dire overshoots and Vicia undershoots the data by 50% each. At 7 TeV, the Dire module presents a good prediction, whereas the Simple and Vincia modules underestimate the data within 30% and 50%. Comparing the Simple module of the Pythia model and the predictions of the CRMC models with the experimental data shows that at 0.9 TeV, EPOS-LHC has better results than the others. At 2.36 GeV, the cosmic rays Monte Carlo (CRMC) models have better prediction than the Simple module of Pythia at low pT, while QGSJETII-04 predicts well at high pT. QGSJETII-04 and EPOS-LHC have closer results than the Pythia-Simple and Sibyll2.3d at 7 TeV. In the case of the pseudorapidity distributions, only the Pythia-Simple reproduced the experimental measurements at all energies. The Dire module overestimates, while Vincia underestimates the data in decreasing order of discrepancy (20%, 12%, 5%) with energy. All CRMC models underestimate the data over the entire η range at all energies by 20%. The angular ordering of partons and the parton fragmentation could be possible reasons for this deviation. Furthermore, we used the two-component standard distribution to fit the pT spectra to the experimental data and extracted the effective temperature (Teff) and the multiplicity parameter (N0). It is observed that Teff increases with the increase in the center of mass energy. The fit yielded 0.20368±0.01, 0.22348±0.011, and 0.24128±0.012 GeV for 0.9, 2.36, and 7 TeV, respectively. This shows that the system at higher energies freezes out earlier than lower ones because they quickly attain the equilibrium state.

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